TEST DROP ME
[rust-lightning] / lightning / src / ln / channel.rs
1 // This file is Copyright its original authors, visible in version control
2 // history.
3 //
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
8 // licenses.
9
10 use bitcoin::blockdata::script::{Script,Builder};
11 use bitcoin::blockdata::transaction::{Transaction, SigHashType};
12 use bitcoin::util::bip143;
13 use bitcoin::consensus::encode;
14
15 use bitcoin::hashes::Hash;
16 use bitcoin::hashes::sha256::Hash as Sha256;
17 use bitcoin::hashes::sha256d::Hash as Sha256d;
18 use bitcoin::hash_types::{Txid, BlockHash};
19
20 use bitcoin::secp256k1::constants::PUBLIC_KEY_SIZE;
21 use bitcoin::secp256k1::key::{PublicKey,SecretKey};
22 use bitcoin::secp256k1::{Secp256k1,Signature};
23 use bitcoin::secp256k1;
24
25 use ln::{PaymentPreimage, PaymentHash};
26 use ln::features::{ChannelFeatures, ChannelTypeFeatures, InitFeatures};
27 use ln::msgs;
28 use ln::msgs::{DecodeError, OptionalField, DataLossProtect};
29 use ln::script::{self, ShutdownScript};
30 use ln::channelmanager::{CounterpartyForwardingInfo, PendingHTLCStatus, HTLCSource, HTLCFailReason, HTLCFailureMsg, PendingHTLCInfo, RAACommitmentOrder, BREAKDOWN_TIMEOUT, MIN_CLTV_EXPIRY_DELTA, MAX_LOCAL_BREAKDOWN_TIMEOUT};
31 use ln::chan_utils::{CounterpartyCommitmentSecrets, TxCreationKeys, HTLCOutputInCommitment, HTLC_SUCCESS_TX_WEIGHT, HTLC_TIMEOUT_TX_WEIGHT, make_funding_redeemscript, ChannelPublicKeys, CommitmentTransaction, HolderCommitmentTransaction, ChannelTransactionParameters, CounterpartyChannelTransactionParameters, MAX_HTLCS, get_commitment_transaction_number_obscure_factor, ClosingTransaction};
32 use ln::chan_utils;
33 use chain::BestBlock;
34 use chain::chaininterface::{FeeEstimator,ConfirmationTarget};
35 use chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateStep, LATENCY_GRACE_PERIOD_BLOCKS};
36 use chain::transaction::{OutPoint, TransactionData};
37 use chain::keysinterface::{Sign, KeysInterface};
38 use util::events::ClosureReason;
39 use util::ser::{Readable, ReadableArgs, Writeable, Writer, VecWriter};
40 use util::logger::Logger;
41 use util::errors::APIError;
42 use util::config::{UserConfig,ChannelConfig};
43 use util::scid_utils::scid_from_parts;
44
45 use io;
46 use prelude::*;
47 use core::{cmp,mem,fmt};
48 use core::ops::Deref;
49 #[cfg(any(test, feature = "fuzztarget", debug_assertions))]
50 use sync::Mutex;
51 use bitcoin::hashes::hex::ToHex;
52
53 #[cfg(test)]
54 pub struct ChannelValueStat {
55         pub value_to_self_msat: u64,
56         pub channel_value_msat: u64,
57         pub channel_reserve_msat: u64,
58         pub pending_outbound_htlcs_amount_msat: u64,
59         pub pending_inbound_htlcs_amount_msat: u64,
60         pub holding_cell_outbound_amount_msat: u64,
61         pub counterparty_max_htlc_value_in_flight_msat: u64, // outgoing
62         pub counterparty_dust_limit_msat: u64,
63 }
64
65 #[derive(Debug, Clone, Copy, PartialEq)]
66 enum FeeUpdateState {
67         // Inbound states mirroring InboundHTLCState
68         RemoteAnnounced,
69         AwaitingRemoteRevokeToAnnounce,
70         // Note that we do not have a AwaitingAnnouncedRemoteRevoke variant here as it is universally
71         // handled the same as `Committed`, with the only exception in `InboundHTLCState` being the
72         // distinction of when we allow ourselves to forward the HTLC. Because we aren't "forwarding"
73         // the fee update anywhere, we can simply consider the fee update `Committed` immediately
74         // instead of setting it to AwaitingAnnouncedRemoteRevoke.
75
76         // Outbound state can only be `LocalAnnounced` or `Committed`
77         Outbound,
78 }
79
80 enum InboundHTLCRemovalReason {
81         FailRelay(msgs::OnionErrorPacket),
82         FailMalformed(([u8; 32], u16)),
83         Fulfill(PaymentPreimage),
84 }
85
86 enum InboundHTLCState {
87         /// Offered by remote, to be included in next local commitment tx. I.e., the remote sent an
88         /// update_add_htlc message for this HTLC.
89         RemoteAnnounced(PendingHTLCStatus),
90         /// Included in a received commitment_signed message (implying we've
91         /// revoke_and_ack'd it), but the remote hasn't yet revoked their previous
92         /// state (see the example below). We have not yet included this HTLC in a
93         /// commitment_signed message because we are waiting on the remote's
94         /// aforementioned state revocation. One reason this missing remote RAA
95         /// (revoke_and_ack) blocks us from constructing a commitment_signed message
96         /// is because every time we create a new "state", i.e. every time we sign a
97         /// new commitment tx (see [BOLT #2]), we need a new per_commitment_point,
98         /// which are provided one-at-a-time in each RAA. E.g., the last RAA they
99         /// sent provided the per_commitment_point for our current commitment tx.
100         /// The other reason we should not send a commitment_signed without their RAA
101         /// is because their RAA serves to ACK our previous commitment_signed.
102         ///
103         /// Here's an example of how an HTLC could come to be in this state:
104         /// remote --> update_add_htlc(prev_htlc)   --> local
105         /// remote --> commitment_signed(prev_htlc) --> local
106         /// remote <-- revoke_and_ack               <-- local
107         /// remote <-- commitment_signed(prev_htlc) <-- local
108         /// [note that here, the remote does not respond with a RAA]
109         /// remote --> update_add_htlc(this_htlc)   --> local
110         /// remote --> commitment_signed(prev_htlc, this_htlc) --> local
111         /// Now `this_htlc` will be assigned this state. It's unable to be officially
112         /// accepted, i.e. included in a commitment_signed, because we're missing the
113         /// RAA that provides our next per_commitment_point. The per_commitment_point
114         /// is used to derive commitment keys, which are used to construct the
115         /// signatures in a commitment_signed message.
116         /// Implies AwaitingRemoteRevoke.
117         ///
118         /// [BOLT #2]: https://github.com/lightningnetwork/lightning-rfc/blob/master/02-peer-protocol.md
119         AwaitingRemoteRevokeToAnnounce(PendingHTLCStatus),
120         /// Included in a received commitment_signed message (implying we've revoke_and_ack'd it).
121         /// We have also included this HTLC in our latest commitment_signed and are now just waiting
122         /// on the remote's revoke_and_ack to make this HTLC an irrevocable part of the state of the
123         /// channel (before it can then get forwarded and/or removed).
124         /// Implies AwaitingRemoteRevoke.
125         AwaitingAnnouncedRemoteRevoke(PendingHTLCStatus),
126         Committed,
127         /// Removed by us and a new commitment_signed was sent (if we were AwaitingRemoteRevoke when we
128         /// created it we would have put it in the holding cell instead). When they next revoke_and_ack
129         /// we'll drop it.
130         /// Note that we have to keep an eye on the HTLC until we've received a broadcastable
131         /// commitment transaction without it as otherwise we'll have to force-close the channel to
132         /// claim it before the timeout (obviously doesn't apply to revoked HTLCs that we can't claim
133         /// anyway). That said, ChannelMonitor does this for us (see
134         /// ChannelMonitor::should_broadcast_holder_commitment_txn) so we actually remove the HTLC from
135         /// our own local state before then, once we're sure that the next commitment_signed and
136         /// ChannelMonitor::provide_latest_local_commitment_tx will not include this HTLC.
137         LocalRemoved(InboundHTLCRemovalReason),
138 }
139
140 struct InboundHTLCOutput {
141         htlc_id: u64,
142         amount_msat: u64,
143         cltv_expiry: u32,
144         payment_hash: PaymentHash,
145         state: InboundHTLCState,
146 }
147
148 enum OutboundHTLCState {
149         /// Added by us and included in a commitment_signed (if we were AwaitingRemoteRevoke when we
150         /// created it we would have put it in the holding cell instead). When they next revoke_and_ack
151         /// we will promote to Committed (note that they may not accept it until the next time we
152         /// revoke, but we don't really care about that:
153         ///  * they've revoked, so worst case we can announce an old state and get our (option on)
154         ///    money back (though we won't), and,
155         ///  * we'll send them a revoke when they send a commitment_signed, and since only they're
156         ///    allowed to remove it, the "can only be removed once committed on both sides" requirement
157         ///    doesn't matter to us and it's up to them to enforce it, worst-case they jump ahead but
158         ///    we'll never get out of sync).
159         /// Note that we Box the OnionPacket as it's rather large and we don't want to blow up
160         /// OutboundHTLCOutput's size just for a temporary bit
161         LocalAnnounced(Box<msgs::OnionPacket>),
162         Committed,
163         /// Remote removed this (outbound) HTLC. We're waiting on their commitment_signed to finalize
164         /// the change (though they'll need to revoke before we fail the payment).
165         RemoteRemoved(Option<HTLCFailReason>),
166         /// Remote removed this and sent a commitment_signed (implying we've revoke_and_ack'ed it), but
167         /// the remote side hasn't yet revoked their previous state, which we need them to do before we
168         /// can do any backwards failing. Implies AwaitingRemoteRevoke.
169         /// We also have not yet removed this HTLC in a commitment_signed message, and are waiting on a
170         /// remote revoke_and_ack on a previous state before we can do so.
171         AwaitingRemoteRevokeToRemove(Option<HTLCFailReason>),
172         /// Remote removed this and sent a commitment_signed (implying we've revoke_and_ack'ed it), but
173         /// the remote side hasn't yet revoked their previous state, which we need them to do before we
174         /// can do any backwards failing. Implies AwaitingRemoteRevoke.
175         /// We have removed this HTLC in our latest commitment_signed and are now just waiting on a
176         /// revoke_and_ack to drop completely.
177         AwaitingRemovedRemoteRevoke(Option<HTLCFailReason>),
178 }
179
180 struct OutboundHTLCOutput {
181         htlc_id: u64,
182         amount_msat: u64,
183         cltv_expiry: u32,
184         payment_hash: PaymentHash,
185         state: OutboundHTLCState,
186         source: HTLCSource,
187 }
188
189 /// See AwaitingRemoteRevoke ChannelState for more info
190 enum HTLCUpdateAwaitingACK {
191         AddHTLC { // TODO: Time out if we're getting close to cltv_expiry
192                 // always outbound
193                 amount_msat: u64,
194                 cltv_expiry: u32,
195                 payment_hash: PaymentHash,
196                 source: HTLCSource,
197                 onion_routing_packet: msgs::OnionPacket,
198         },
199         ClaimHTLC {
200                 payment_preimage: PaymentPreimage,
201                 htlc_id: u64,
202         },
203         FailHTLC {
204                 htlc_id: u64,
205                 err_packet: msgs::OnionErrorPacket,
206         },
207 }
208
209 /// There are a few "states" and then a number of flags which can be applied:
210 /// We first move through init with OurInitSent -> TheirInitSent -> FundingCreated -> FundingSent.
211 /// TheirFundingLocked and OurFundingLocked then get set on FundingSent, and when both are set we
212 /// move on to ChannelFunded.
213 /// Note that PeerDisconnected can be set on both ChannelFunded and FundingSent.
214 /// ChannelFunded can then get all remaining flags set on it, until we finish shutdown, then we
215 /// move on to ShutdownComplete, at which point most calls into this channel are disallowed.
216 enum ChannelState {
217         /// Implies we have (or are prepared to) send our open_channel/accept_channel message
218         OurInitSent = 1 << 0,
219         /// Implies we have received their open_channel/accept_channel message
220         TheirInitSent = 1 << 1,
221         /// We have sent funding_created and are awaiting a funding_signed to advance to FundingSent.
222         /// Note that this is nonsense for an inbound channel as we immediately generate funding_signed
223         /// upon receipt of funding_created, so simply skip this state.
224         FundingCreated = 4,
225         /// Set when we have received/sent funding_created and funding_signed and are thus now waiting
226         /// on the funding transaction to confirm. The FundingLocked flags are set to indicate when we
227         /// and our counterparty consider the funding transaction confirmed.
228         FundingSent = 8,
229         /// Flag which can be set on FundingSent to indicate they sent us a funding_locked message.
230         /// Once both TheirFundingLocked and OurFundingLocked are set, state moves on to ChannelFunded.
231         TheirFundingLocked = 1 << 4,
232         /// Flag which can be set on FundingSent to indicate we sent them a funding_locked message.
233         /// Once both TheirFundingLocked and OurFundingLocked are set, state moves on to ChannelFunded.
234         OurFundingLocked = 1 << 5,
235         ChannelFunded = 64,
236         /// Flag which is set on ChannelFunded and FundingSent indicating remote side is considered
237         /// "disconnected" and no updates are allowed until after we've done a channel_reestablish
238         /// dance.
239         PeerDisconnected = 1 << 7,
240         /// Flag which is set on ChannelFunded, FundingCreated, and FundingSent indicating the user has
241         /// told us they failed to update our ChannelMonitor somewhere and we should pause sending any
242         /// outbound messages until they've managed to do so.
243         MonitorUpdateFailed = 1 << 8,
244         /// Flag which implies that we have sent a commitment_signed but are awaiting the responding
245         /// revoke_and_ack message. During this time period, we can't generate new commitment_signed
246         /// messages as then we will be unable to determine which HTLCs they included in their
247         /// revoke_and_ack implicit ACK, so instead we have to hold them away temporarily to be sent
248         /// later.
249         /// Flag is set on ChannelFunded.
250         AwaitingRemoteRevoke = 1 << 9,
251         /// Flag which is set on ChannelFunded or FundingSent after receiving a shutdown message from
252         /// the remote end. If set, they may not add any new HTLCs to the channel, and we are expected
253         /// to respond with our own shutdown message when possible.
254         RemoteShutdownSent = 1 << 10,
255         /// Flag which is set on ChannelFunded or FundingSent after sending a shutdown message. At this
256         /// point, we may not add any new HTLCs to the channel.
257         LocalShutdownSent = 1 << 11,
258         /// We've successfully negotiated a closing_signed dance. At this point ChannelManager is about
259         /// to drop us, but we store this anyway.
260         ShutdownComplete = 4096,
261 }
262 const BOTH_SIDES_SHUTDOWN_MASK: u32 = ChannelState::LocalShutdownSent as u32 | ChannelState::RemoteShutdownSent as u32;
263 const MULTI_STATE_FLAGS: u32 = BOTH_SIDES_SHUTDOWN_MASK | ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateFailed as u32;
264
265 pub const INITIAL_COMMITMENT_NUMBER: u64 = (1 << 48) - 1;
266
267 /// The "channel disabled" bit in channel_update must be set based on whether we are connected to
268 /// our counterparty or not. However, we don't want to announce updates right away to avoid
269 /// spamming the network with updates if the connection is flapping. Instead, we "stage" updates to
270 /// our channel_update message and track the current state here.
271 /// See implementation at [`super::channelmanager::ChannelManager::timer_tick_occurred`].
272 #[derive(Clone, Copy, PartialEq)]
273 pub(super) enum ChannelUpdateStatus {
274         /// We've announced the channel as enabled and are connected to our peer.
275         Enabled,
276         /// Our channel is no longer live, but we haven't announced the channel as disabled yet.
277         DisabledStaged,
278         /// Our channel is live again, but we haven't announced the channel as enabled yet.
279         EnabledStaged,
280         /// We've announced the channel as disabled.
281         Disabled,
282 }
283
284 /// We track when we sent an `AnnouncementSignatures` to our peer in a few states, described here.
285 #[derive(PartialEq)]
286 pub enum AnnouncementSigsState {
287         /// We have not sent our peer an `AnnouncementSignatures` yet, or our peer disconnected since
288         /// we sent the last `AnnouncementSignatures`.
289         NotSent,
290         /// We sent an `AnnouncementSignatures` to our peer since the last time our peer disconnected.
291         /// This state never appears on disk - instead we write `NotSent`.
292         MessageSent,
293         /// We sent a `CommitmentSigned` after the last `AnnouncementSignatures` we sent. Because we
294         /// only ever have a single `CommitmentSigned` pending at once, if we sent one after sending
295         /// `AnnouncementSignatures` then we know the peer received our `AnnouncementSignatures` if
296         /// they send back a `RevokeAndACK`.
297         /// This state never appears on disk - instead we write `NotSent`.
298         Committed,
299         /// We received a `RevokeAndACK`, effectively ack-ing our `AnnouncementSignatures`, at this
300         /// point we no longer need to re-send our `AnnouncementSignatures` again on reconnect.
301         PeerReceived,
302 }
303
304 /// An enum indicating whether the local or remote side offered a given HTLC.
305 enum HTLCInitiator {
306         LocalOffered,
307         RemoteOffered,
308 }
309
310 /// An enum gathering stats on pending HTLCs, either inbound or outbound side.
311 struct HTLCStats {
312         pending_htlcs: u32,
313         pending_htlcs_value_msat: u64,
314         on_counterparty_tx_dust_exposure_msat: u64,
315         on_holder_tx_dust_exposure_msat: u64,
316         holding_cell_msat: u64,
317         on_holder_tx_holding_cell_htlcs_count: u32, // dust HTLCs *non*-included
318 }
319
320 /// An enum gathering stats on commitment transaction, either local or remote.
321 struct CommitmentStats<'a> {
322         tx: CommitmentTransaction, // the transaction info
323         feerate_per_kw: u32, // the feerate included to build the transaction
324         total_fee_sat: u64, // the total fee included in the transaction
325         num_nondust_htlcs: usize,  // the number of HTLC outputs (dust HTLCs *non*-included)
326         htlcs_included: Vec<(HTLCOutputInCommitment, Option<&'a HTLCSource>)>, // the list of HTLCs (dust HTLCs *included*) which were not ignored when building the transaction
327         local_balance_msat: u64, // local balance before fees but considering dust limits
328         remote_balance_msat: u64, // remote balance before fees but considering dust limits
329 }
330
331 /// Used when calculating whether we or the remote can afford an additional HTLC.
332 struct HTLCCandidate {
333         amount_msat: u64,
334         origin: HTLCInitiator,
335 }
336
337 impl HTLCCandidate {
338         fn new(amount_msat: u64, origin: HTLCInitiator) -> Self {
339                 Self {
340                         amount_msat,
341                         origin,
342                 }
343         }
344 }
345
346 /// A return value enum for get_update_fulfill_htlc. See UpdateFulfillCommitFetch variants for
347 /// description
348 enum UpdateFulfillFetch {
349         NewClaim {
350                 monitor_update: ChannelMonitorUpdate,
351                 htlc_value_msat: u64,
352                 msg: Option<msgs::UpdateFulfillHTLC>,
353         },
354         DuplicateClaim {},
355 }
356
357 /// The return type of get_update_fulfill_htlc_and_commit.
358 pub enum UpdateFulfillCommitFetch {
359         /// Indicates the HTLC fulfill is new, and either generated an update_fulfill message, placed
360         /// it in the holding cell, or re-generated the update_fulfill message after the same claim was
361         /// previously placed in the holding cell (and has since been removed).
362         NewClaim {
363                 /// The ChannelMonitorUpdate which places the new payment preimage in the channel monitor
364                 monitor_update: ChannelMonitorUpdate,
365                 /// The value of the HTLC which was claimed, in msat.
366                 htlc_value_msat: u64,
367                 /// The update_fulfill message and commitment_signed message (if the claim was not placed
368                 /// in the holding cell).
369                 msgs: Option<(msgs::UpdateFulfillHTLC, msgs::CommitmentSigned)>,
370         },
371         /// Indicates the HTLC fulfill is duplicative and already existed either in the holding cell
372         /// or has been forgotten (presumably previously claimed).
373         DuplicateClaim {},
374 }
375
376 /// The return value of `revoke_and_ack` on success, primarily updates to other channels or HTLC
377 /// state.
378 pub(super) struct RAAUpdates {
379         pub commitment_update: Option<msgs::CommitmentUpdate>,
380         pub accepted_htlcs: Vec<(PendingHTLCInfo, u64)>,
381         pub failed_htlcs: Vec<(HTLCSource, PaymentHash, HTLCFailReason)>,
382         pub finalized_claimed_htlcs: Vec<HTLCSource>,
383         pub monitor_update: ChannelMonitorUpdate,
384         pub holding_cell_failed_htlcs: Vec<(HTLCSource, PaymentHash)>,
385 }
386
387 /// The return value of `monitor_updating_restored`
388 pub(super) struct MonitorRestoreUpdates {
389         pub raa: Option<msgs::RevokeAndACK>,
390         pub commitment_update: Option<msgs::CommitmentUpdate>,
391         pub order: RAACommitmentOrder,
392         pub accepted_htlcs: Vec<(PendingHTLCInfo, u64)>,
393         pub failed_htlcs: Vec<(HTLCSource, PaymentHash, HTLCFailReason)>,
394         pub finalized_claimed_htlcs: Vec<HTLCSource>,
395         pub funding_broadcastable: Option<Transaction>,
396         pub funding_locked: Option<msgs::FundingLocked>,
397         pub announcement_sigs: Option<msgs::AnnouncementSignatures>,
398 }
399
400 /// The return value of `channel_reestablish`
401 pub(super) struct ReestablishResponses {
402         pub funding_locked: Option<msgs::FundingLocked>,
403         pub raa: Option<msgs::RevokeAndACK>,
404         pub commitment_update: Option<msgs::CommitmentUpdate>,
405         pub order: RAACommitmentOrder,
406         pub mon_update: Option<ChannelMonitorUpdate>,
407         pub holding_cell_failed_htlcs: Vec<(HTLCSource, PaymentHash)>,
408         pub announcement_sigs: Option<msgs::AnnouncementSignatures>,
409         pub shutdown: Option<msgs::Shutdown>,
410 }
411
412 /// If the majority of the channels funds are to the fundee and the initiator holds only just
413 /// enough funds to cover their reserve value, channels are at risk of getting "stuck". Because the
414 /// initiator controls the feerate, if they then go to increase the channel fee, they may have no
415 /// balance but the fundee is unable to send a payment as the increase in fee more than drains
416 /// their reserve value. Thus, neither side can send a new HTLC and the channel becomes useless.
417 /// Thus, before sending an HTLC when we are the initiator, we check that the feerate can increase
418 /// by this multiple without hitting this case, before sending.
419 /// This multiple is effectively the maximum feerate "jump" we expect until more HTLCs flow over
420 /// the channel. Sadly, there isn't really a good number for this - if we expect to have no new
421 /// HTLCs for days we may need this to suffice for feerate increases across days, but that may
422 /// leave the channel less usable as we hold a bigger reserve.
423 #[cfg(any(fuzzing, test))]
424 pub const FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE: u64 = 2;
425 #[cfg(not(any(fuzzing, test)))]
426 const FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE: u64 = 2;
427
428 /// If we fail to see a funding transaction confirmed on-chain within this many blocks after the
429 /// channel creation on an inbound channel, we simply force-close and move on.
430 /// This constant is the one suggested in BOLT 2.
431 pub(crate) const FUNDING_CONF_DEADLINE_BLOCKS: u32 = 2016;
432
433 /// In case of a concurrent update_add_htlc proposed by our counterparty, we might
434 /// not have enough balance value remaining to cover the onchain cost of this new
435 /// HTLC weight. If this happens, our counterparty fails the reception of our
436 /// commitment_signed including this new HTLC due to infringement on the channel
437 /// reserve.
438 /// To prevent this case, we compute our outbound update_fee with an HTLC buffer of
439 /// size 2. However, if the number of concurrent update_add_htlc is higher, this still
440 /// leads to a channel force-close. Ultimately, this is an issue coming from the
441 /// design of LN state machines, allowing asynchronous updates.
442 pub(crate) const CONCURRENT_INBOUND_HTLC_FEE_BUFFER: u32 = 2;
443
444 /// When a channel is opened, we check that the funding amount is enough to pay for relevant
445 /// commitment transaction fees, with at least this many HTLCs present on the commitment
446 /// transaction (not counting the value of the HTLCs themselves).
447 pub(crate) const MIN_AFFORDABLE_HTLC_COUNT: usize = 4;
448
449 // TODO: We should refactor this to be an Inbound/OutboundChannel until initial setup handshaking
450 // has been completed, and then turn into a Channel to get compiler-time enforcement of things like
451 // calling channel_id() before we're set up or things like get_outbound_funding_signed on an
452 // inbound channel.
453 //
454 // Holder designates channel data owned for the benefice of the user client.
455 // Counterparty designates channel data owned by the another channel participant entity.
456 pub(super) struct Channel<Signer: Sign> {
457         #[cfg(any(test, feature = "_test_utils"))]
458         pub(crate) config: ChannelConfig,
459         #[cfg(not(any(test, feature = "_test_utils")))]
460         config: ChannelConfig,
461
462         user_id: u64,
463
464         channel_id: [u8; 32],
465         channel_state: u32,
466
467         // When we reach max(6 blocks, minimum_depth), we need to send an AnnouncementSigs message to
468         // our peer. However, we want to make sure they received it, or else rebroadcast it when we
469         // next connect.
470         // We do so here, see `AnnouncementSigsSent` for more details on the state(s).
471         // Note that a number of our tests were written prior to the behavior here which retransmits
472         // AnnouncementSignatures until after an RAA completes, so the behavior is short-circuited in
473         // many tests.
474         #[cfg(any(test, feature = "_test_utils"))]
475         pub(crate) announcement_sigs_state: AnnouncementSigsState,
476         #[cfg(not(any(test, feature = "_test_utils")))]
477         announcement_sigs_state: AnnouncementSigsState,
478
479         secp_ctx: Secp256k1<secp256k1::All>,
480         channel_value_satoshis: u64,
481
482         latest_monitor_update_id: u64,
483
484         holder_signer: Signer,
485         shutdown_scriptpubkey: Option<ShutdownScript>,
486         destination_script: Script,
487
488         // Our commitment numbers start at 2^48-1 and count down, whereas the ones used in transaction
489         // generation start at 0 and count up...this simplifies some parts of implementation at the
490         // cost of others, but should really just be changed.
491
492         cur_holder_commitment_transaction_number: u64,
493         cur_counterparty_commitment_transaction_number: u64,
494         value_to_self_msat: u64, // Excluding all pending_htlcs, excluding fees
495         pending_inbound_htlcs: Vec<InboundHTLCOutput>,
496         pending_outbound_htlcs: Vec<OutboundHTLCOutput>,
497         holding_cell_htlc_updates: Vec<HTLCUpdateAwaitingACK>,
498
499         /// When resending CS/RAA messages on channel monitor restoration or on reconnect, we always
500         /// need to ensure we resend them in the order we originally generated them. Note that because
501         /// there can only ever be one in-flight CS and/or one in-flight RAA at any time, it is
502         /// sufficient to simply set this to the opposite of any message we are generating as we
503         /// generate it. ie when we generate a CS, we set this to RAAFirst as, if there is a pending
504         /// in-flight RAA to resend, it will have been the first thing we generated, and thus we should
505         /// send it first.
506         resend_order: RAACommitmentOrder,
507
508         monitor_pending_funding_locked: bool,
509         monitor_pending_revoke_and_ack: bool,
510         monitor_pending_commitment_signed: bool,
511         monitor_pending_forwards: Vec<(PendingHTLCInfo, u64)>,
512         monitor_pending_failures: Vec<(HTLCSource, PaymentHash, HTLCFailReason)>,
513         monitor_pending_finalized_fulfills: Vec<HTLCSource>,
514
515         // pending_update_fee is filled when sending and receiving update_fee.
516         //
517         // Because it follows the same commitment flow as HTLCs, `FeeUpdateState` is either `Outbound`
518         // or matches a subset of the `InboundHTLCOutput` variants. It is then updated/used when
519         // generating new commitment transactions with exactly the same criteria as inbound/outbound
520         // HTLCs with similar state.
521         pending_update_fee: Option<(u32, FeeUpdateState)>,
522         // If a `send_update_fee()` call is made with ChannelState::AwaitingRemoteRevoke set, we place
523         // it here instead of `pending_update_fee` in the same way as we place outbound HTLC updates in
524         // `holding_cell_htlc_updates` instead of `pending_outbound_htlcs`. It is released into
525         // `pending_update_fee` with the same criteria as outbound HTLC updates but can be updated by
526         // further `send_update_fee` calls, dropping the previous holding cell update entirely.
527         holding_cell_update_fee: Option<u32>,
528         next_holder_htlc_id: u64,
529         next_counterparty_htlc_id: u64,
530         feerate_per_kw: u32,
531
532         /// The timestamp set on our latest `channel_update` message for this channel. It is updated
533         /// when the channel is updated in ways which may impact the `channel_update` message or when a
534         /// new block is received, ensuring it's always at least moderately close to the current real
535         /// time.
536         update_time_counter: u32,
537
538         #[cfg(debug_assertions)]
539         /// Max to_local and to_remote outputs in a locally-generated commitment transaction
540         holder_max_commitment_tx_output: Mutex<(u64, u64)>,
541         #[cfg(debug_assertions)]
542         /// Max to_local and to_remote outputs in a remote-generated commitment transaction
543         counterparty_max_commitment_tx_output: Mutex<(u64, u64)>,
544
545         last_sent_closing_fee: Option<(u64, Signature)>, // (fee, holder_sig)
546         target_closing_feerate_sats_per_kw: Option<u32>,
547
548         /// If our counterparty sent us a closing_signed while we were waiting for a `ChannelMonitor`
549         /// update, we need to delay processing it until later. We do that here by simply storing the
550         /// closing_signed message and handling it in `maybe_propose_closing_signed`.
551         pending_counterparty_closing_signed: Option<msgs::ClosingSigned>,
552
553         /// The minimum and maximum absolute fee, in satoshis, we are willing to place on the closing
554         /// transaction. These are set once we reach `closing_negotiation_ready`.
555         #[cfg(test)]
556         pub(crate) closing_fee_limits: Option<(u64, u64)>,
557         #[cfg(not(test))]
558         closing_fee_limits: Option<(u64, u64)>,
559
560         /// The hash of the block in which the funding transaction was included.
561         funding_tx_confirmed_in: Option<BlockHash>,
562         funding_tx_confirmation_height: u32,
563         short_channel_id: Option<u64>,
564         /// Either the height at which this channel was created or the height at which it was last
565         /// serialized if it was serialized by versions prior to 0.0.103.
566         /// We use this to close if funding is never broadcasted.
567         channel_creation_height: u32,
568
569         counterparty_dust_limit_satoshis: u64,
570
571         #[cfg(test)]
572         pub(super) holder_dust_limit_satoshis: u64,
573         #[cfg(not(test))]
574         holder_dust_limit_satoshis: u64,
575
576         #[cfg(test)]
577         pub(super) counterparty_max_htlc_value_in_flight_msat: u64,
578         #[cfg(not(test))]
579         counterparty_max_htlc_value_in_flight_msat: u64,
580
581         #[cfg(test)]
582         pub(super) holder_max_htlc_value_in_flight_msat: u64,
583         #[cfg(not(test))]
584         holder_max_htlc_value_in_flight_msat: u64,
585
586         /// minimum channel reserve for self to maintain - set by them.
587         counterparty_selected_channel_reserve_satoshis: Option<u64>,
588
589         #[cfg(test)]
590         pub(super) holder_selected_channel_reserve_satoshis: u64,
591         #[cfg(not(test))]
592         holder_selected_channel_reserve_satoshis: u64,
593
594         counterparty_htlc_minimum_msat: u64,
595         holder_htlc_minimum_msat: u64,
596         #[cfg(test)]
597         pub counterparty_max_accepted_htlcs: u16,
598         #[cfg(not(test))]
599         counterparty_max_accepted_htlcs: u16,
600         //implied by OUR_MAX_HTLCS: max_accepted_htlcs: u16,
601         minimum_depth: Option<u32>,
602
603         counterparty_forwarding_info: Option<CounterpartyForwardingInfo>,
604
605         pub(crate) channel_transaction_parameters: ChannelTransactionParameters,
606         funding_transaction: Option<Transaction>,
607
608         counterparty_cur_commitment_point: Option<PublicKey>,
609         counterparty_prev_commitment_point: Option<PublicKey>,
610         counterparty_node_id: PublicKey,
611
612         counterparty_shutdown_scriptpubkey: Option<Script>,
613
614         commitment_secrets: CounterpartyCommitmentSecrets,
615
616         channel_update_status: ChannelUpdateStatus,
617         /// Once we reach `closing_negotiation_ready`, we set this, indicating if closing_signed does
618         /// not complete within a single timer tick (one minute), we should force-close the channel.
619         /// This prevents us from keeping unusable channels around forever if our counterparty wishes
620         /// to DoS us.
621         /// Note that this field is reset to false on deserialization to give us a chance to connect to
622         /// our peer and start the closing_signed negotiation fresh.
623         closing_signed_in_flight: bool,
624
625         /// Our counterparty's channel_announcement signatures provided in announcement_signatures.
626         /// This can be used to rebroadcast the channel_announcement message later.
627         announcement_sigs: Option<(Signature, Signature)>,
628
629         // We save these values so we can make sure `next_local_commit_tx_fee_msat` and
630         // `next_remote_commit_tx_fee_msat` properly predict what the next commitment transaction fee will
631         // be, by comparing the cached values to the fee of the tranaction generated by
632         // `build_commitment_transaction`.
633         #[cfg(any(test, feature = "fuzztarget"))]
634         next_local_commitment_tx_fee_info_cached: Mutex<Option<CommitmentTxInfoCached>>,
635         #[cfg(any(test, feature = "fuzztarget"))]
636         next_remote_commitment_tx_fee_info_cached: Mutex<Option<CommitmentTxInfoCached>>,
637
638         /// lnd has a long-standing bug where, upon reconnection, if the channel is not yet confirmed
639         /// they will not send a channel_reestablish until the channel locks in. Then, they will send a
640         /// funding_locked *before* sending the channel_reestablish (which is clearly a violation of
641         /// the BOLT specs). We copy c-lightning's workaround here and simply store the funding_locked
642         /// message until we receive a channel_reestablish.
643         ///
644         /// See-also <https://github.com/lightningnetwork/lnd/issues/4006>
645         pub workaround_lnd_bug_4006: Option<msgs::FundingLocked>,
646
647         #[cfg(any(test, feature = "fuzztarget"))]
648         // When we receive an HTLC fulfill on an outbound path, we may immediately fulfill the
649         // corresponding HTLC on the inbound path. If, then, the outbound path channel is
650         // disconnected and reconnected (before we've exchange commitment_signed and revoke_and_ack
651         // messages), they may re-broadcast their update_fulfill_htlc, causing a duplicate claim. This
652         // is fine, but as a sanity check in our failure to generate the second claim, we check here
653         // that the original was a claim, and that we aren't now trying to fulfill a failed HTLC.
654         historical_inbound_htlc_fulfills: HashSet<u64>,
655
656         /// This channel's type, as negotiated during channel open
657         channel_type: ChannelTypeFeatures,
658
659         // Our counerparty can offer us SCID aliases which they will map to this channel when routing
660         // outbound payments. These can be used in invoice route hints to provide privacy of which
661         // on-chain transaction is ours.
662         // We only bother storing the most recent SCID alias at any time, though our counterparty has
663         // to store all of them.
664         latest_inbound_scid_alias: Option<u64>,
665 }
666
667 #[cfg(any(test, feature = "fuzztarget"))]
668 struct CommitmentTxInfoCached {
669         fee: u64,
670         total_pending_htlcs: usize,
671         next_holder_htlc_id: u64,
672         next_counterparty_htlc_id: u64,
673         feerate: u32,
674 }
675
676 pub const OUR_MAX_HTLCS: u16 = 50; //TODO
677
678 #[cfg(not(test))]
679 const COMMITMENT_TX_BASE_WEIGHT: u64 = 724;
680 #[cfg(test)]
681 pub const COMMITMENT_TX_BASE_WEIGHT: u64 = 724;
682 #[cfg(not(test))]
683 const COMMITMENT_TX_WEIGHT_PER_HTLC: u64 = 172;
684 #[cfg(test)]
685 pub const COMMITMENT_TX_WEIGHT_PER_HTLC: u64 = 172;
686
687 pub const ANCHOR_OUTPUT_VALUE_SATOSHI: u64 = 330;
688
689 /// Maximum `funding_satoshis` value, according to the BOLT #2 specification
690 /// it's 2^24.
691 pub const MAX_FUNDING_SATOSHIS: u64 = 1 << 24;
692
693 /// The maximum network dust limit for standard script formats. This currently represents the
694 /// minimum output value for a P2SH output before Bitcoin Core 22 considers the entire
695 /// transaction non-standard and thus refuses to relay it.
696 /// We also use this as the maximum counterparty `dust_limit_satoshis` allowed, given many
697 /// implementations use this value for their dust limit today.
698 pub const MAX_STD_OUTPUT_DUST_LIMIT_SATOSHIS: u64 = 546;
699
700 /// The maximum channel dust limit we will accept from our counterparty.
701 pub const MAX_CHAN_DUST_LIMIT_SATOSHIS: u64 = MAX_STD_OUTPUT_DUST_LIMIT_SATOSHIS;
702
703 /// The dust limit is used for both the commitment transaction outputs as well as the closing
704 /// transactions. For cooperative closing transactions, we require segwit outputs, though accept
705 /// *any* segwit scripts, which are allowed to be up to 42 bytes in length.
706 /// In order to avoid having to concern ourselves with standardness during the closing process, we
707 /// simply require our counterparty to use a dust limit which will leave any segwit output
708 /// standard.
709 /// See https://github.com/lightningnetwork/lightning-rfc/issues/905 for more details.
710 pub const MIN_CHAN_DUST_LIMIT_SATOSHIS: u64 = 354;
711
712 /// Used to return a simple Error back to ChannelManager. Will get converted to a
713 /// msgs::ErrorAction::SendErrorMessage or msgs::ErrorAction::IgnoreError as appropriate with our
714 /// channel_id in ChannelManager.
715 pub(super) enum ChannelError {
716         Ignore(String),
717         Warn(String),
718         Close(String),
719         CloseDelayBroadcast(String),
720 }
721
722 impl fmt::Debug for ChannelError {
723         fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
724                 match self {
725                         &ChannelError::Ignore(ref e) => write!(f, "Ignore : {}", e),
726                         &ChannelError::Warn(ref e) => write!(f, "Warn : {}", e),
727                         &ChannelError::Close(ref e) => write!(f, "Close : {}", e),
728                         &ChannelError::CloseDelayBroadcast(ref e) => write!(f, "CloseDelayBroadcast : {}", e)
729                 }
730         }
731 }
732
733 macro_rules! secp_check {
734         ($res: expr, $err: expr) => {
735                 match $res {
736                         Ok(thing) => thing,
737                         Err(_) => return Err(ChannelError::Close($err)),
738                 }
739         };
740 }
741
742 impl<Signer: Sign> Channel<Signer> {
743         // Convert constants + channel value to limits:
744         fn get_holder_max_htlc_value_in_flight_msat(channel_value_satoshis: u64) -> u64 {
745                 channel_value_satoshis * 1000 / 10 //TODO
746         }
747
748         /// Returns a minimum channel reserve value the remote needs to maintain,
749         /// required by us.
750         ///
751         /// Guaranteed to return a value no larger than channel_value_satoshis
752         ///
753         /// This is used both for new channels and to figure out what reserve value we sent to peers
754         /// for channels serialized before we included our selected reserve value in the serialized
755         /// data explicitly.
756         pub(crate) fn get_holder_selected_channel_reserve_satoshis(channel_value_satoshis: u64) -> u64 {
757                 let (q, _) = channel_value_satoshis.overflowing_div(100);
758                 cmp::min(channel_value_satoshis, cmp::max(q, 1000)) //TODO
759         }
760
761         pub(crate) fn opt_anchors(&self) -> bool {
762                 self.channel_transaction_parameters.opt_anchors.is_some()
763         }
764
765         // Constructors:
766         pub fn new_outbound<K: Deref, F: Deref>(
767                 fee_estimator: &F, keys_provider: &K, counterparty_node_id: PublicKey, their_features: &InitFeatures,
768                 channel_value_satoshis: u64, push_msat: u64, user_id: u64, config: &UserConfig, current_chain_height: u32
769         ) -> Result<Channel<Signer>, APIError>
770         where K::Target: KeysInterface<Signer = Signer>,
771               F::Target: FeeEstimator,
772         {
773                 let holder_selected_contest_delay = config.own_channel_config.our_to_self_delay;
774                 let holder_signer = keys_provider.get_channel_signer(false, channel_value_satoshis);
775                 let pubkeys = holder_signer.pubkeys().clone();
776
777                 if channel_value_satoshis >= MAX_FUNDING_SATOSHIS {
778                         return Err(APIError::APIMisuseError{err: format!("funding_value must be smaller than {}, it was {}", MAX_FUNDING_SATOSHIS, channel_value_satoshis)});
779                 }
780                 let channel_value_msat = channel_value_satoshis * 1000;
781                 if push_msat > channel_value_msat {
782                         return Err(APIError::APIMisuseError { err: format!("Push value ({}) was larger than channel_value ({})", push_msat, channel_value_msat) });
783                 }
784                 if holder_selected_contest_delay < BREAKDOWN_TIMEOUT {
785                         return Err(APIError::APIMisuseError {err: format!("Configured with an unreasonable our_to_self_delay ({}) putting user funds at risks", holder_selected_contest_delay)});
786                 }
787                 let holder_selected_channel_reserve_satoshis = Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(channel_value_satoshis);
788                 if holder_selected_channel_reserve_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
789                         return Err(APIError::APIMisuseError { err: format!("Holder selected channel  reserve below implemention limit dust_limit_satoshis {}", holder_selected_channel_reserve_satoshis) });
790                 }
791
792                 let feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);
793
794                 let value_to_self_msat = channel_value_satoshis * 1000 - push_msat;
795                 let commitment_tx_fee = Self::commit_tx_fee_msat(feerate, MIN_AFFORDABLE_HTLC_COUNT);
796                 if value_to_self_msat < commitment_tx_fee {
797                         return Err(APIError::APIMisuseError{ err: format!("Funding amount ({}) can't even pay fee for initial commitment transaction fee of {}.", value_to_self_msat / 1000, commitment_tx_fee / 1000) });
798                 }
799
800                 let mut secp_ctx = Secp256k1::new();
801                 secp_ctx.seeded_randomize(&keys_provider.get_secure_random_bytes());
802
803                 let shutdown_scriptpubkey = if config.channel_options.commit_upfront_shutdown_pubkey {
804                         Some(keys_provider.get_shutdown_scriptpubkey())
805                 } else { None };
806
807                 if let Some(shutdown_scriptpubkey) = &shutdown_scriptpubkey {
808                         if !shutdown_scriptpubkey.is_compatible(&their_features) {
809                                 return Err(APIError::IncompatibleShutdownScript { script: shutdown_scriptpubkey.clone() });
810                         }
811                 }
812
813                 Ok(Channel {
814                         user_id,
815                         config: config.channel_options.clone(),
816
817                         channel_id: keys_provider.get_secure_random_bytes(),
818                         channel_state: ChannelState::OurInitSent as u32,
819                         announcement_sigs_state: AnnouncementSigsState::NotSent,
820                         secp_ctx,
821                         channel_value_satoshis,
822
823                         latest_monitor_update_id: 0,
824
825                         holder_signer,
826                         shutdown_scriptpubkey,
827                         destination_script: keys_provider.get_destination_script(),
828
829                         cur_holder_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
830                         cur_counterparty_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
831                         value_to_self_msat,
832
833                         pending_inbound_htlcs: Vec::new(),
834                         pending_outbound_htlcs: Vec::new(),
835                         holding_cell_htlc_updates: Vec::new(),
836                         pending_update_fee: None,
837                         holding_cell_update_fee: None,
838                         next_holder_htlc_id: 0,
839                         next_counterparty_htlc_id: 0,
840                         update_time_counter: 1,
841
842                         resend_order: RAACommitmentOrder::CommitmentFirst,
843
844                         monitor_pending_funding_locked: false,
845                         monitor_pending_revoke_and_ack: false,
846                         monitor_pending_commitment_signed: false,
847                         monitor_pending_forwards: Vec::new(),
848                         monitor_pending_failures: Vec::new(),
849                         monitor_pending_finalized_fulfills: Vec::new(),
850
851                         #[cfg(debug_assertions)]
852                         holder_max_commitment_tx_output: Mutex::new((channel_value_satoshis * 1000 - push_msat, push_msat)),
853                         #[cfg(debug_assertions)]
854                         counterparty_max_commitment_tx_output: Mutex::new((channel_value_satoshis * 1000 - push_msat, push_msat)),
855
856                         last_sent_closing_fee: None,
857                         pending_counterparty_closing_signed: None,
858                         closing_fee_limits: None,
859                         target_closing_feerate_sats_per_kw: None,
860
861                         funding_tx_confirmed_in: None,
862                         funding_tx_confirmation_height: 0,
863                         short_channel_id: None,
864                         channel_creation_height: current_chain_height,
865
866                         feerate_per_kw: feerate,
867                         counterparty_dust_limit_satoshis: 0,
868                         holder_dust_limit_satoshis: MIN_CHAN_DUST_LIMIT_SATOSHIS,
869                         counterparty_max_htlc_value_in_flight_msat: 0,
870                         holder_max_htlc_value_in_flight_msat: Self::get_holder_max_htlc_value_in_flight_msat(channel_value_satoshis),
871                         counterparty_selected_channel_reserve_satoshis: None, // Filled in in accept_channel
872                         holder_selected_channel_reserve_satoshis,
873                         counterparty_htlc_minimum_msat: 0,
874                         holder_htlc_minimum_msat: if config.own_channel_config.our_htlc_minimum_msat == 0 { 1 } else { config.own_channel_config.our_htlc_minimum_msat },
875                         counterparty_max_accepted_htlcs: 0,
876                         minimum_depth: None, // Filled in in accept_channel
877
878                         counterparty_forwarding_info: None,
879
880                         channel_transaction_parameters: ChannelTransactionParameters {
881                                 holder_pubkeys: pubkeys,
882                                 holder_selected_contest_delay: config.own_channel_config.our_to_self_delay,
883                                 is_outbound_from_holder: true,
884                                 counterparty_parameters: None,
885                                 funding_outpoint: None,
886                                 opt_anchors: None,
887                         },
888                         funding_transaction: None,
889
890                         counterparty_cur_commitment_point: None,
891                         counterparty_prev_commitment_point: None,
892                         counterparty_node_id,
893
894                         counterparty_shutdown_scriptpubkey: None,
895
896                         commitment_secrets: CounterpartyCommitmentSecrets::new(),
897
898                         channel_update_status: ChannelUpdateStatus::Enabled,
899                         closing_signed_in_flight: false,
900
901                         announcement_sigs: None,
902
903                         #[cfg(any(test, feature = "fuzztarget"))]
904                         next_local_commitment_tx_fee_info_cached: Mutex::new(None),
905                         #[cfg(any(test, feature = "fuzztarget"))]
906                         next_remote_commitment_tx_fee_info_cached: Mutex::new(None),
907
908                         workaround_lnd_bug_4006: None,
909
910                         latest_inbound_scid_alias: None,
911
912                         #[cfg(any(test, feature = "fuzztarget"))]
913                         historical_inbound_htlc_fulfills: HashSet::new(),
914
915                         // We currently only actually support one channel type, so don't retry with new types
916                         // on error messages. When we support more we'll need fallback support (assuming we
917                         // want to support old types).
918                         channel_type: ChannelTypeFeatures::only_static_remote_key(),
919                 })
920         }
921
922         fn check_remote_fee<F: Deref>(fee_estimator: &F, feerate_per_kw: u32) -> Result<(), ChannelError>
923                 where F::Target: FeeEstimator
924         {
925                 let lower_limit = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
926                 // Some fee estimators round up to the next full sat/vbyte (ie 250 sats per kw), causing
927                 // occasional issues with feerate disagreements between an initiator that wants a feerate
928                 // of 1.1 sat/vbyte and a receiver that wants 1.1 rounded up to 2. Thus, we always add 250
929                 // sat/kw before the comparison here.
930                 if feerate_per_kw + 250 < lower_limit {
931                         return Err(ChannelError::Close(format!("Peer's feerate much too low. Actual: {}. Our expected lower limit: {} (- 250)", feerate_per_kw, lower_limit)));
932                 }
933                 // We only bound the fee updates on the upper side to prevent completely absurd feerates,
934                 // always accepting up to 25 sat/vByte or 10x our fee estimator's "High Priority" fee.
935                 // We generally don't care too much if they set the feerate to something very high, but it
936                 // could result in the channel being useless due to everything being dust.
937                 let upper_limit = cmp::max(250 * 25,
938                         fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) as u64 * 10);
939                 if feerate_per_kw as u64 > upper_limit {
940                         return Err(ChannelError::Close(format!("Peer's feerate much too high. Actual: {}. Our expected upper limit: {}", feerate_per_kw, upper_limit)));
941                 }
942                 Ok(())
943         }
944
945         /// Creates a new channel from a remote sides' request for one.
946         /// Assumes chain_hash has already been checked and corresponds with what we expect!
947         pub fn new_from_req<K: Deref, F: Deref, L: Deref>(
948                 fee_estimator: &F, keys_provider: &K, counterparty_node_id: PublicKey, their_features: &InitFeatures,
949                 msg: &msgs::OpenChannel, user_id: u64, config: &UserConfig, current_chain_height: u32, logger: &L
950         ) -> Result<Channel<Signer>, ChannelError>
951                 where K::Target: KeysInterface<Signer = Signer>,
952                       F::Target: FeeEstimator,
953                       L::Target: Logger,
954         {
955                 // First check the channel type is known, failing before we do anything else if we don't
956                 // support this channel type.
957                 let channel_type = if let Some(channel_type) = &msg.channel_type {
958                         if channel_type.supports_any_optional_bits() {
959                                 return Err(ChannelError::Close("Channel Type field contained optional bits - this is not allowed".to_owned()));
960                         }
961                         if *channel_type != ChannelTypeFeatures::only_static_remote_key() {
962                                 return Err(ChannelError::Close("Channel Type was not understood".to_owned()));
963                         }
964                         channel_type.clone()
965                 } else {
966                         ChannelTypeFeatures::from_counterparty_init(&their_features)
967                 };
968                 if !channel_type.supports_static_remote_key() {
969                         return Err(ChannelError::Close("Channel Type was not understood - we require static remote key".to_owned()));
970                 }
971
972                 let holder_signer = keys_provider.get_channel_signer(true, msg.funding_satoshis);
973                 let pubkeys = holder_signer.pubkeys().clone();
974                 let counterparty_pubkeys = ChannelPublicKeys {
975                         funding_pubkey: msg.funding_pubkey,
976                         revocation_basepoint: msg.revocation_basepoint,
977                         payment_point: msg.payment_point,
978                         delayed_payment_basepoint: msg.delayed_payment_basepoint,
979                         htlc_basepoint: msg.htlc_basepoint
980                 };
981                 let mut local_config = (*config).channel_options.clone();
982
983                 if config.own_channel_config.our_to_self_delay < BREAKDOWN_TIMEOUT {
984                         return Err(ChannelError::Close(format!("Configured with an unreasonable our_to_self_delay ({}) putting user funds at risks. It must be greater than {}", config.own_channel_config.our_to_self_delay, BREAKDOWN_TIMEOUT)));
985                 }
986
987                 // Check sanity of message fields:
988                 if msg.funding_satoshis >= MAX_FUNDING_SATOSHIS {
989                         return Err(ChannelError::Close(format!("Funding must be smaller than {}. It was {}", MAX_FUNDING_SATOSHIS, msg.funding_satoshis)));
990                 }
991                 if msg.channel_reserve_satoshis > msg.funding_satoshis {
992                         return Err(ChannelError::Close(format!("Bogus channel_reserve_satoshis ({}). Must be not greater than funding_satoshis: {}", msg.channel_reserve_satoshis, msg.funding_satoshis)));
993                 }
994                 let funding_value = (msg.funding_satoshis - msg.channel_reserve_satoshis) * 1000;
995                 if msg.push_msat > funding_value {
996                         return Err(ChannelError::Close(format!("push_msat {} was larger than funding value {}", msg.push_msat, funding_value)));
997                 }
998                 if msg.dust_limit_satoshis > msg.funding_satoshis {
999                         return Err(ChannelError::Close(format!("dust_limit_satoshis {} was larger than funding_satoshis {}. Peer never wants payout outputs?", msg.dust_limit_satoshis, msg.funding_satoshis)));
1000                 }
1001                 let full_channel_value_msat = (msg.funding_satoshis - msg.channel_reserve_satoshis) * 1000;
1002                 if msg.htlc_minimum_msat >= full_channel_value_msat {
1003                         return Err(ChannelError::Close(format!("Minimum htlc value ({}) was larger than full channel value ({})", msg.htlc_minimum_msat, full_channel_value_msat)));
1004                 }
1005                 Channel::<Signer>::check_remote_fee(fee_estimator, msg.feerate_per_kw)?;
1006
1007                 let max_counterparty_selected_contest_delay = u16::min(config.peer_channel_config_limits.their_to_self_delay, MAX_LOCAL_BREAKDOWN_TIMEOUT);
1008                 if msg.to_self_delay > max_counterparty_selected_contest_delay {
1009                         return Err(ChannelError::Close(format!("They wanted our payments to be delayed by a needlessly long period. Upper limit: {}. Actual: {}", max_counterparty_selected_contest_delay, msg.to_self_delay)));
1010                 }
1011                 if msg.max_accepted_htlcs < 1 {
1012                         return Err(ChannelError::Close("0 max_accepted_htlcs makes for a useless channel".to_owned()));
1013                 }
1014                 if msg.max_accepted_htlcs > MAX_HTLCS {
1015                         return Err(ChannelError::Close(format!("max_accepted_htlcs was {}. It must not be larger than {}", msg.max_accepted_htlcs, MAX_HTLCS)));
1016                 }
1017
1018                 // Now check against optional parameters as set by config...
1019                 if msg.funding_satoshis < config.peer_channel_config_limits.min_funding_satoshis {
1020                         return Err(ChannelError::Close(format!("Funding satoshis ({}) is less than the user specified limit ({})", msg.funding_satoshis, config.peer_channel_config_limits.min_funding_satoshis)));
1021                 }
1022                 if msg.htlc_minimum_msat > config.peer_channel_config_limits.max_htlc_minimum_msat {
1023                         return Err(ChannelError::Close(format!("htlc_minimum_msat ({}) is higher than the user specified limit ({})", msg.htlc_minimum_msat,  config.peer_channel_config_limits.max_htlc_minimum_msat)));
1024                 }
1025                 if msg.max_htlc_value_in_flight_msat < config.peer_channel_config_limits.min_max_htlc_value_in_flight_msat {
1026                         return Err(ChannelError::Close(format!("max_htlc_value_in_flight_msat ({}) is less than the user specified limit ({})", msg.max_htlc_value_in_flight_msat, config.peer_channel_config_limits.min_max_htlc_value_in_flight_msat)));
1027                 }
1028                 if msg.channel_reserve_satoshis > config.peer_channel_config_limits.max_channel_reserve_satoshis {
1029                         return Err(ChannelError::Close(format!("channel_reserve_satoshis ({}) is higher than the user specified limit ({})", msg.channel_reserve_satoshis, config.peer_channel_config_limits.max_channel_reserve_satoshis)));
1030                 }
1031                 if msg.max_accepted_htlcs < config.peer_channel_config_limits.min_max_accepted_htlcs {
1032                         return Err(ChannelError::Close(format!("max_accepted_htlcs ({}) is less than the user specified limit ({})", msg.max_accepted_htlcs, config.peer_channel_config_limits.min_max_accepted_htlcs)));
1033                 }
1034                 if msg.dust_limit_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
1035                         return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is less than the implementation limit ({})", msg.dust_limit_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS)));
1036                 }
1037                 if msg.dust_limit_satoshis >  MAX_CHAN_DUST_LIMIT_SATOSHIS {
1038                         return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is greater than the implementation limit ({})", msg.dust_limit_satoshis, MAX_CHAN_DUST_LIMIT_SATOSHIS)));
1039                 }
1040
1041                 // Convert things into internal flags and prep our state:
1042
1043                 let announce = if (msg.channel_flags & 1) == 1 { true } else { false };
1044                 if config.peer_channel_config_limits.force_announced_channel_preference {
1045                         if local_config.announced_channel != announce {
1046                                 return Err(ChannelError::Close("Peer tried to open channel but their announcement preference is different from ours".to_owned()));
1047                         }
1048                 }
1049                 // we either accept their preference or the preferences match
1050                 local_config.announced_channel = announce;
1051
1052                 let holder_selected_channel_reserve_satoshis = Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(msg.funding_satoshis);
1053                 if holder_selected_channel_reserve_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
1054                         return Err(ChannelError::Close(format!("Suitable channel reserve not found. remote_channel_reserve was ({}). dust_limit_satoshis is ({}).", holder_selected_channel_reserve_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS)));
1055                 }
1056                 if msg.channel_reserve_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
1057                         log_debug!(logger, "channel_reserve_satoshis ({}) is smaller than our dust limit ({}). We can broadcast stale states without any risk, implying this channel is very insecure for our counterparty.",
1058                                 msg.channel_reserve_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS);
1059                 }
1060                 if holder_selected_channel_reserve_satoshis < msg.dust_limit_satoshis {
1061                         return Err(ChannelError::Close(format!("Dust limit ({}) too high for the channel reserve we require the remote to keep ({})", msg.dust_limit_satoshis, holder_selected_channel_reserve_satoshis)));
1062                 }
1063
1064                 // check if the funder's amount for the initial commitment tx is sufficient
1065                 // for full fee payment plus a few HTLCs to ensure the channel will be useful.
1066                 let funders_amount_msat = msg.funding_satoshis * 1000 - msg.push_msat;
1067                 let commitment_tx_fee = Self::commit_tx_fee_msat(msg.feerate_per_kw, MIN_AFFORDABLE_HTLC_COUNT) / 1000;
1068                 if funders_amount_msat / 1000 < commitment_tx_fee {
1069                         return Err(ChannelError::Close(format!("Funding amount ({} sats) can't even pay fee for initial commitment transaction fee of {} sats.", funders_amount_msat / 1000, commitment_tx_fee)));
1070                 }
1071
1072                 let to_remote_satoshis = funders_amount_msat / 1000 - commitment_tx_fee;
1073                 // While it's reasonable for us to not meet the channel reserve initially (if they don't
1074                 // want to push much to us), our counterparty should always have more than our reserve.
1075                 if to_remote_satoshis < holder_selected_channel_reserve_satoshis {
1076                         return Err(ChannelError::Close("Insufficient funding amount for initial reserve".to_owned()));
1077                 }
1078
1079                 let counterparty_shutdown_scriptpubkey = if their_features.supports_upfront_shutdown_script() {
1080                         match &msg.shutdown_scriptpubkey {
1081                                 &OptionalField::Present(ref script) => {
1082                                         // Peer is signaling upfront_shutdown and has opt-out with a 0-length script. We don't enforce anything
1083                                         if script.len() == 0 {
1084                                                 None
1085                                         } else {
1086                                                 if !script::is_bolt2_compliant(&script, their_features) {
1087                                                         return Err(ChannelError::Close(format!("Peer is signaling upfront_shutdown but has provided an unacceptable scriptpubkey format: {}", script)))
1088                                                 }
1089                                                 Some(script.clone())
1090                                         }
1091                                 },
1092                                 // Peer is signaling upfront shutdown but don't opt-out with correct mechanism (a.k.a 0-length script). Peer looks buggy, we fail the channel
1093                                 &OptionalField::Absent => {
1094                                         return Err(ChannelError::Close("Peer is signaling upfront_shutdown but we don't get any script. Use 0-length script to opt-out".to_owned()));
1095                                 }
1096                         }
1097                 } else { None };
1098
1099                 let shutdown_scriptpubkey = if config.channel_options.commit_upfront_shutdown_pubkey {
1100                         Some(keys_provider.get_shutdown_scriptpubkey())
1101                 } else { None };
1102
1103                 if let Some(shutdown_scriptpubkey) = &shutdown_scriptpubkey {
1104                         if !shutdown_scriptpubkey.is_compatible(&their_features) {
1105                                 return Err(ChannelError::Close(format!("Provided a scriptpubkey format not accepted by peer: {}", shutdown_scriptpubkey)));
1106                         }
1107                 }
1108
1109                 let mut secp_ctx = Secp256k1::new();
1110                 secp_ctx.seeded_randomize(&keys_provider.get_secure_random_bytes());
1111
1112                 let chan = Channel {
1113                         user_id,
1114                         config: local_config,
1115
1116                         channel_id: msg.temporary_channel_id,
1117                         channel_state: (ChannelState::OurInitSent as u32) | (ChannelState::TheirInitSent as u32),
1118                         announcement_sigs_state: AnnouncementSigsState::NotSent,
1119                         secp_ctx,
1120
1121                         latest_monitor_update_id: 0,
1122
1123                         holder_signer,
1124                         shutdown_scriptpubkey,
1125                         destination_script: keys_provider.get_destination_script(),
1126
1127                         cur_holder_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
1128                         cur_counterparty_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
1129                         value_to_self_msat: msg.push_msat,
1130
1131                         pending_inbound_htlcs: Vec::new(),
1132                         pending_outbound_htlcs: Vec::new(),
1133                         holding_cell_htlc_updates: Vec::new(),
1134                         pending_update_fee: None,
1135                         holding_cell_update_fee: None,
1136                         next_holder_htlc_id: 0,
1137                         next_counterparty_htlc_id: 0,
1138                         update_time_counter: 1,
1139
1140                         resend_order: RAACommitmentOrder::CommitmentFirst,
1141
1142                         monitor_pending_funding_locked: false,
1143                         monitor_pending_revoke_and_ack: false,
1144                         monitor_pending_commitment_signed: false,
1145                         monitor_pending_forwards: Vec::new(),
1146                         monitor_pending_failures: Vec::new(),
1147                         monitor_pending_finalized_fulfills: Vec::new(),
1148
1149                         #[cfg(debug_assertions)]
1150                         holder_max_commitment_tx_output: Mutex::new((msg.push_msat, msg.funding_satoshis * 1000 - msg.push_msat)),
1151                         #[cfg(debug_assertions)]
1152                         counterparty_max_commitment_tx_output: Mutex::new((msg.push_msat, msg.funding_satoshis * 1000 - msg.push_msat)),
1153
1154                         last_sent_closing_fee: None,
1155                         pending_counterparty_closing_signed: None,
1156                         closing_fee_limits: None,
1157                         target_closing_feerate_sats_per_kw: None,
1158
1159                         funding_tx_confirmed_in: None,
1160                         funding_tx_confirmation_height: 0,
1161                         short_channel_id: None,
1162                         channel_creation_height: current_chain_height,
1163
1164                         feerate_per_kw: msg.feerate_per_kw,
1165                         channel_value_satoshis: msg.funding_satoshis,
1166                         counterparty_dust_limit_satoshis: msg.dust_limit_satoshis,
1167                         holder_dust_limit_satoshis: MIN_CHAN_DUST_LIMIT_SATOSHIS,
1168                         counterparty_max_htlc_value_in_flight_msat: cmp::min(msg.max_htlc_value_in_flight_msat, msg.funding_satoshis * 1000),
1169                         holder_max_htlc_value_in_flight_msat: Self::get_holder_max_htlc_value_in_flight_msat(msg.funding_satoshis),
1170                         counterparty_selected_channel_reserve_satoshis: Some(msg.channel_reserve_satoshis),
1171                         holder_selected_channel_reserve_satoshis,
1172                         counterparty_htlc_minimum_msat: msg.htlc_minimum_msat,
1173                         holder_htlc_minimum_msat: if config.own_channel_config.our_htlc_minimum_msat == 0 { 1 } else { config.own_channel_config.our_htlc_minimum_msat },
1174                         counterparty_max_accepted_htlcs: msg.max_accepted_htlcs,
1175                         minimum_depth: Some(config.own_channel_config.minimum_depth),
1176
1177                         counterparty_forwarding_info: None,
1178
1179                         channel_transaction_parameters: ChannelTransactionParameters {
1180                                 holder_pubkeys: pubkeys,
1181                                 holder_selected_contest_delay: config.own_channel_config.our_to_self_delay,
1182                                 is_outbound_from_holder: false,
1183                                 counterparty_parameters: Some(CounterpartyChannelTransactionParameters {
1184                                         selected_contest_delay: msg.to_self_delay,
1185                                         pubkeys: counterparty_pubkeys,
1186                                 }),
1187                                 funding_outpoint: None,
1188                                 opt_anchors: None
1189                         },
1190                         funding_transaction: None,
1191
1192                         counterparty_cur_commitment_point: Some(msg.first_per_commitment_point),
1193                         counterparty_prev_commitment_point: None,
1194                         counterparty_node_id,
1195
1196                         counterparty_shutdown_scriptpubkey,
1197
1198                         commitment_secrets: CounterpartyCommitmentSecrets::new(),
1199
1200                         channel_update_status: ChannelUpdateStatus::Enabled,
1201                         closing_signed_in_flight: false,
1202
1203                         announcement_sigs: None,
1204
1205                         #[cfg(any(test, feature = "fuzztarget"))]
1206                         next_local_commitment_tx_fee_info_cached: Mutex::new(None),
1207                         #[cfg(any(test, feature = "fuzztarget"))]
1208                         next_remote_commitment_tx_fee_info_cached: Mutex::new(None),
1209
1210                         workaround_lnd_bug_4006: None,
1211
1212                         latest_inbound_scid_alias: None,
1213
1214                         #[cfg(any(test, feature = "fuzztarget"))]
1215                         historical_inbound_htlc_fulfills: HashSet::new(),
1216
1217                         channel_type,
1218                 };
1219
1220                 Ok(chan)
1221         }
1222
1223         /// Transaction nomenclature is somewhat confusing here as there are many different cases - a
1224         /// transaction is referred to as "a's transaction" implying that a will be able to broadcast
1225         /// the transaction. Thus, b will generally be sending a signature over such a transaction to
1226         /// a, and a can revoke the transaction by providing b the relevant per_commitment_secret. As
1227         /// such, a transaction is generally the result of b increasing the amount paid to a (or adding
1228         /// an HTLC to a).
1229         /// @local is used only to convert relevant internal structures which refer to remote vs local
1230         /// to decide value of outputs and direction of HTLCs.
1231         /// @generated_by_local is used to determine *which* HTLCs to include - noting that the HTLC
1232         /// state may indicate that one peer has informed the other that they'd like to add an HTLC but
1233         /// have not yet committed it. Such HTLCs will only be included in transactions which are being
1234         /// generated by the peer which proposed adding the HTLCs, and thus we need to understand both
1235         /// which peer generated this transaction and "to whom" this transaction flows.
1236         #[inline]
1237         fn build_commitment_transaction<L: Deref>(&self, commitment_number: u64, keys: &TxCreationKeys, local: bool, generated_by_local: bool, logger: &L) -> CommitmentStats
1238                 where L::Target: Logger
1239         {
1240                 let mut included_dust_htlcs: Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)> = Vec::new();
1241                 let num_htlcs = self.pending_inbound_htlcs.len() + self.pending_outbound_htlcs.len();
1242                 let mut included_non_dust_htlcs: Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)> = Vec::with_capacity(num_htlcs);
1243
1244                 let broadcaster_dust_limit_satoshis = if local { self.holder_dust_limit_satoshis } else { self.counterparty_dust_limit_satoshis };
1245                 let mut remote_htlc_total_msat = 0;
1246                 let mut local_htlc_total_msat = 0;
1247                 let mut value_to_self_msat_offset = 0;
1248
1249                 let mut feerate_per_kw = self.feerate_per_kw;
1250                 if let Some((feerate, update_state)) = self.pending_update_fee {
1251                         if match update_state {
1252                                 // Note that these match the inclusion criteria when scanning
1253                                 // pending_inbound_htlcs below.
1254                                 FeeUpdateState::RemoteAnnounced => { debug_assert!(!self.is_outbound()); !generated_by_local },
1255                                 FeeUpdateState::AwaitingRemoteRevokeToAnnounce => { debug_assert!(!self.is_outbound()); !generated_by_local },
1256                                 FeeUpdateState::Outbound => { assert!(self.is_outbound());  generated_by_local },
1257                         } {
1258                                 feerate_per_kw = feerate;
1259                         }
1260                 }
1261
1262                 log_trace!(logger, "Building commitment transaction number {} (really {} xor {}) for channel {} for {}, generated by {} with fee {}...",
1263                         commitment_number, (INITIAL_COMMITMENT_NUMBER - commitment_number),
1264                         get_commitment_transaction_number_obscure_factor(&self.get_holder_pubkeys().payment_point, &self.get_counterparty_pubkeys().payment_point, self.is_outbound()),
1265                         log_bytes!(self.channel_id), if local { "us" } else { "remote" }, if generated_by_local { "us" } else { "remote" }, feerate_per_kw);
1266
1267                 macro_rules! get_htlc_in_commitment {
1268                         ($htlc: expr, $offered: expr) => {
1269                                 HTLCOutputInCommitment {
1270                                         offered: $offered,
1271                                         amount_msat: $htlc.amount_msat,
1272                                         cltv_expiry: $htlc.cltv_expiry,
1273                                         payment_hash: $htlc.payment_hash,
1274                                         transaction_output_index: None
1275                                 }
1276                         }
1277                 }
1278
1279                 macro_rules! add_htlc_output {
1280                         ($htlc: expr, $outbound: expr, $source: expr, $state_name: expr) => {
1281                                 if $outbound == local { // "offered HTLC output"
1282                                         let htlc_in_tx = get_htlc_in_commitment!($htlc, true);
1283                                         if $htlc.amount_msat / 1000 >= broadcaster_dust_limit_satoshis + (feerate_per_kw as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000) {
1284                                                 log_trace!(logger, "   ...including {} {} HTLC {} (hash {}) with value {}", if $outbound { "outbound" } else { "inbound" }, $state_name, $htlc.htlc_id, log_bytes!($htlc.payment_hash.0), $htlc.amount_msat);
1285                                                 included_non_dust_htlcs.push((htlc_in_tx, $source));
1286                                         } else {
1287                                                 log_trace!(logger, "   ...including {} {} dust HTLC {} (hash {}) with value {} due to dust limit", if $outbound { "outbound" } else { "inbound" }, $state_name, $htlc.htlc_id, log_bytes!($htlc.payment_hash.0), $htlc.amount_msat);
1288                                                 included_dust_htlcs.push((htlc_in_tx, $source));
1289                                         }
1290                                 } else {
1291                                         let htlc_in_tx = get_htlc_in_commitment!($htlc, false);
1292                                         if $htlc.amount_msat / 1000 >= broadcaster_dust_limit_satoshis + (feerate_per_kw as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000) {
1293                                                 log_trace!(logger, "   ...including {} {} HTLC {} (hash {}) with value {}", if $outbound { "outbound" } else { "inbound" }, $state_name, $htlc.htlc_id, log_bytes!($htlc.payment_hash.0), $htlc.amount_msat);
1294                                                 included_non_dust_htlcs.push((htlc_in_tx, $source));
1295                                         } else {
1296                                                 log_trace!(logger, "   ...including {} {} dust HTLC {} (hash {}) with value {}", if $outbound { "outbound" } else { "inbound" }, $state_name, $htlc.htlc_id, log_bytes!($htlc.payment_hash.0), $htlc.amount_msat);
1297                                                 included_dust_htlcs.push((htlc_in_tx, $source));
1298                                         }
1299                                 }
1300                         }
1301                 }
1302
1303                 for ref htlc in self.pending_inbound_htlcs.iter() {
1304                         let (include, state_name) = match htlc.state {
1305                                 InboundHTLCState::RemoteAnnounced(_) => (!generated_by_local, "RemoteAnnounced"),
1306                                 InboundHTLCState::AwaitingRemoteRevokeToAnnounce(_) => (!generated_by_local, "AwaitingRemoteRevokeToAnnounce"),
1307                                 InboundHTLCState::AwaitingAnnouncedRemoteRevoke(_) => (true, "AwaitingAnnouncedRemoteRevoke"),
1308                                 InboundHTLCState::Committed => (true, "Committed"),
1309                                 InboundHTLCState::LocalRemoved(_) => (!generated_by_local, "LocalRemoved"),
1310                         };
1311
1312                         if include {
1313                                 add_htlc_output!(htlc, false, None, state_name);
1314                                 remote_htlc_total_msat += htlc.amount_msat;
1315                         } else {
1316                                 log_trace!(logger, "   ...not including inbound HTLC {} (hash {}) with value {} due to state ({})", htlc.htlc_id, log_bytes!(htlc.payment_hash.0), htlc.amount_msat, state_name);
1317                                 match &htlc.state {
1318                                         &InboundHTLCState::LocalRemoved(ref reason) => {
1319                                                 if generated_by_local {
1320                                                         if let &InboundHTLCRemovalReason::Fulfill(_) = reason {
1321                                                                 value_to_self_msat_offset += htlc.amount_msat as i64;
1322                                                         }
1323                                                 }
1324                                         },
1325                                         _ => {},
1326                                 }
1327                         }
1328                 }
1329
1330                 for ref htlc in self.pending_outbound_htlcs.iter() {
1331                         let (include, state_name) = match htlc.state {
1332                                 OutboundHTLCState::LocalAnnounced(_) => (generated_by_local, "LocalAnnounced"),
1333                                 OutboundHTLCState::Committed => (true, "Committed"),
1334                                 OutboundHTLCState::RemoteRemoved(_) => (generated_by_local, "RemoteRemoved"),
1335                                 OutboundHTLCState::AwaitingRemoteRevokeToRemove(_) => (generated_by_local, "AwaitingRemoteRevokeToRemove"),
1336                                 OutboundHTLCState::AwaitingRemovedRemoteRevoke(_) => (false, "AwaitingRemovedRemoteRevoke"),
1337                         };
1338
1339                         if include {
1340                                 add_htlc_output!(htlc, true, Some(&htlc.source), state_name);
1341                                 local_htlc_total_msat += htlc.amount_msat;
1342                         } else {
1343                                 log_trace!(logger, "   ...not including outbound HTLC {} (hash {}) with value {} due to state ({})", htlc.htlc_id, log_bytes!(htlc.payment_hash.0), htlc.amount_msat, state_name);
1344                                 match htlc.state {
1345                                         OutboundHTLCState::AwaitingRemoteRevokeToRemove(None)|OutboundHTLCState::AwaitingRemovedRemoteRevoke(None) => {
1346                                                 value_to_self_msat_offset -= htlc.amount_msat as i64;
1347                                         },
1348                                         OutboundHTLCState::RemoteRemoved(None) => {
1349                                                 if !generated_by_local {
1350                                                         value_to_self_msat_offset -= htlc.amount_msat as i64;
1351                                                 }
1352                                         },
1353                                         _ => {},
1354                                 }
1355                         }
1356                 }
1357
1358                 let mut value_to_self_msat: i64 = (self.value_to_self_msat - local_htlc_total_msat) as i64 + value_to_self_msat_offset;
1359                 assert!(value_to_self_msat >= 0);
1360                 // Note that in case they have several just-awaiting-last-RAA fulfills in-progress (ie
1361                 // AwaitingRemoteRevokeToRemove or AwaitingRemovedRemoteRevoke) we may have allowed them to
1362                 // "violate" their reserve value by couting those against it. Thus, we have to convert
1363                 // everything to i64 before subtracting as otherwise we can overflow.
1364                 let mut value_to_remote_msat: i64 = (self.channel_value_satoshis * 1000) as i64 - (self.value_to_self_msat as i64) - (remote_htlc_total_msat as i64) - value_to_self_msat_offset;
1365                 assert!(value_to_remote_msat >= 0);
1366
1367                 #[cfg(debug_assertions)]
1368                 {
1369                         // Make sure that the to_self/to_remote is always either past the appropriate
1370                         // channel_reserve *or* it is making progress towards it.
1371                         let mut broadcaster_max_commitment_tx_output = if generated_by_local {
1372                                 self.holder_max_commitment_tx_output.lock().unwrap()
1373                         } else {
1374                                 self.counterparty_max_commitment_tx_output.lock().unwrap()
1375                         };
1376                         debug_assert!(broadcaster_max_commitment_tx_output.0 <= value_to_self_msat as u64 || value_to_self_msat / 1000 >= self.counterparty_selected_channel_reserve_satoshis.unwrap() as i64);
1377                         broadcaster_max_commitment_tx_output.0 = cmp::max(broadcaster_max_commitment_tx_output.0, value_to_self_msat as u64);
1378                         debug_assert!(broadcaster_max_commitment_tx_output.1 <= value_to_remote_msat as u64 || value_to_remote_msat / 1000 >= self.holder_selected_channel_reserve_satoshis as i64);
1379                         broadcaster_max_commitment_tx_output.1 = cmp::max(broadcaster_max_commitment_tx_output.1, value_to_remote_msat as u64);
1380                 }
1381
1382                 let total_fee_sat = Channel::<Signer>::commit_tx_fee_sat(feerate_per_kw, included_non_dust_htlcs.len());
1383                 let (value_to_self, value_to_remote) = if self.is_outbound() {
1384                         (value_to_self_msat / 1000 - total_fee_sat as i64, value_to_remote_msat / 1000)
1385                 } else {
1386                         (value_to_self_msat / 1000, value_to_remote_msat / 1000 - total_fee_sat as i64)
1387                 };
1388
1389                 let mut value_to_a = if local { value_to_self } else { value_to_remote };
1390                 let mut value_to_b = if local { value_to_remote } else { value_to_self };
1391                 let (funding_pubkey_a, funding_pubkey_b) = if local {
1392                         (self.get_holder_pubkeys().funding_pubkey, self.get_counterparty_pubkeys().funding_pubkey)
1393                 } else {
1394                         (self.get_counterparty_pubkeys().funding_pubkey, self.get_holder_pubkeys().funding_pubkey)
1395                 };
1396
1397                 if value_to_a >= (broadcaster_dust_limit_satoshis as i64) {
1398                         log_trace!(logger, "   ...including {} output with value {}", if local { "to_local" } else { "to_remote" }, value_to_a);
1399                 } else {
1400                         value_to_a = 0;
1401                 }
1402
1403                 if value_to_b >= (broadcaster_dust_limit_satoshis as i64) {
1404                         log_trace!(logger, "   ...including {} output with value {}", if local { "to_remote" } else { "to_local" }, value_to_b);
1405                 } else {
1406                         value_to_b = 0;
1407                 }
1408
1409                 let num_nondust_htlcs = included_non_dust_htlcs.len();
1410
1411                 let channel_parameters =
1412                         if local { self.channel_transaction_parameters.as_holder_broadcastable() }
1413                         else { self.channel_transaction_parameters.as_counterparty_broadcastable() };
1414                 let tx = CommitmentTransaction::new_with_auxiliary_htlc_data(commitment_number,
1415                                                                              value_to_a as u64,
1416                                                                              value_to_b as u64,
1417                                                                              self.channel_transaction_parameters.opt_anchors.is_some(),
1418                                                                              funding_pubkey_a,
1419                                                                              funding_pubkey_b,
1420                                                                              keys.clone(),
1421                                                                              feerate_per_kw,
1422                                                                              &mut included_non_dust_htlcs,
1423                                                                              &channel_parameters
1424                 );
1425                 let mut htlcs_included = included_non_dust_htlcs;
1426                 // The unwrap is safe, because all non-dust HTLCs have been assigned an output index
1427                 htlcs_included.sort_unstable_by_key(|h| h.0.transaction_output_index.unwrap());
1428                 htlcs_included.append(&mut included_dust_htlcs);
1429
1430                 // For the stats, trimmed-to-0 the value in msats accordingly
1431                 value_to_self_msat = if (value_to_self_msat * 1000) < broadcaster_dust_limit_satoshis as i64 { 0 } else { value_to_self_msat };
1432                 value_to_remote_msat = if (value_to_remote_msat * 1000) < broadcaster_dust_limit_satoshis as i64 { 0 } else { value_to_remote_msat };
1433
1434                 CommitmentStats {
1435                         tx,
1436                         feerate_per_kw,
1437                         total_fee_sat,
1438                         num_nondust_htlcs,
1439                         htlcs_included,
1440                         local_balance_msat: value_to_self_msat as u64,
1441                         remote_balance_msat: value_to_remote_msat as u64,
1442                 }
1443         }
1444
1445         #[inline]
1446         fn get_closing_scriptpubkey(&self) -> Script {
1447                 // The shutdown scriptpubkey is set on channel opening when option_upfront_shutdown_script
1448                 // is signaled. Otherwise, it is set when sending a shutdown message. Calling this method
1449                 // outside of those situations will fail.
1450                 self.shutdown_scriptpubkey.clone().unwrap().into_inner()
1451         }
1452
1453         #[inline]
1454         fn get_closing_transaction_weight(&self, a_scriptpubkey: Option<&Script>, b_scriptpubkey: Option<&Script>) -> u64 {
1455                 let mut ret =
1456                 (4 +                                           // version
1457                  1 +                                           // input count
1458                  36 +                                          // prevout
1459                  1 +                                           // script length (0)
1460                  4 +                                           // sequence
1461                  1 +                                           // output count
1462                  4                                             // lock time
1463                  )*4 +                                         // * 4 for non-witness parts
1464                 2 +                                            // witness marker and flag
1465                 1 +                                            // witness element count
1466                 4 +                                            // 4 element lengths (2 sigs, multisig dummy, and witness script)
1467                 self.get_funding_redeemscript().len() as u64 + // funding witness script
1468                 2*(1 + 71);                                    // two signatures + sighash type flags
1469                 if let Some(spk) = a_scriptpubkey {
1470                         ret += ((8+1) +                            // output values and script length
1471                                 spk.len() as u64) * 4;                 // scriptpubkey and witness multiplier
1472                 }
1473                 if let Some(spk) = b_scriptpubkey {
1474                         ret += ((8+1) +                            // output values and script length
1475                                 spk.len() as u64) * 4;                 // scriptpubkey and witness multiplier
1476                 }
1477                 ret
1478         }
1479
1480         #[inline]
1481         fn build_closing_transaction(&self, proposed_total_fee_satoshis: u64, skip_remote_output: bool) -> (ClosingTransaction, u64) {
1482                 assert!(self.pending_inbound_htlcs.is_empty());
1483                 assert!(self.pending_outbound_htlcs.is_empty());
1484                 assert!(self.pending_update_fee.is_none());
1485
1486                 let mut total_fee_satoshis = proposed_total_fee_satoshis;
1487                 let mut value_to_holder: i64 = (self.value_to_self_msat as i64) / 1000 - if self.is_outbound() { total_fee_satoshis as i64 } else { 0 };
1488                 let mut value_to_counterparty: i64 = ((self.channel_value_satoshis * 1000 - self.value_to_self_msat) as i64 / 1000) - if self.is_outbound() { 0 } else { total_fee_satoshis as i64 };
1489
1490                 if value_to_holder < 0 {
1491                         assert!(self.is_outbound());
1492                         total_fee_satoshis += (-value_to_holder) as u64;
1493                 } else if value_to_counterparty < 0 {
1494                         assert!(!self.is_outbound());
1495                         total_fee_satoshis += (-value_to_counterparty) as u64;
1496                 }
1497
1498                 if skip_remote_output || value_to_counterparty as u64 <= self.holder_dust_limit_satoshis {
1499                         value_to_counterparty = 0;
1500                 }
1501
1502                 if value_to_holder as u64 <= self.holder_dust_limit_satoshis {
1503                         value_to_holder = 0;
1504                 }
1505
1506                 assert!(self.shutdown_scriptpubkey.is_some());
1507                 let holder_shutdown_script = self.get_closing_scriptpubkey();
1508                 let counterparty_shutdown_script = self.counterparty_shutdown_scriptpubkey.clone().unwrap();
1509                 let funding_outpoint = self.funding_outpoint().into_bitcoin_outpoint();
1510
1511                 let closing_transaction = ClosingTransaction::new(value_to_holder as u64, value_to_counterparty as u64, holder_shutdown_script, counterparty_shutdown_script, funding_outpoint);
1512                 (closing_transaction, total_fee_satoshis)
1513         }
1514
1515         fn funding_outpoint(&self) -> OutPoint {
1516                 self.channel_transaction_parameters.funding_outpoint.unwrap()
1517         }
1518
1519         #[inline]
1520         /// Creates a set of keys for build_commitment_transaction to generate a transaction which our
1521         /// counterparty will sign (ie DO NOT send signatures over a transaction created by this to
1522         /// our counterparty!)
1523         /// The result is a transaction which we can revoke broadcastership of (ie a "local" transaction)
1524         /// TODO Some magic rust shit to compile-time check this?
1525         fn build_holder_transaction_keys(&self, commitment_number: u64) -> Result<TxCreationKeys, ChannelError> {
1526                 let per_commitment_point = self.holder_signer.get_per_commitment_point(commitment_number, &self.secp_ctx);
1527                 let delayed_payment_base = &self.get_holder_pubkeys().delayed_payment_basepoint;
1528                 let htlc_basepoint = &self.get_holder_pubkeys().htlc_basepoint;
1529                 let counterparty_pubkeys = self.get_counterparty_pubkeys();
1530
1531                 Ok(secp_check!(TxCreationKeys::derive_new(&self.secp_ctx, &per_commitment_point, delayed_payment_base, htlc_basepoint, &counterparty_pubkeys.revocation_basepoint, &counterparty_pubkeys.htlc_basepoint), "Local tx keys generation got bogus keys".to_owned()))
1532         }
1533
1534         #[inline]
1535         /// Creates a set of keys for build_commitment_transaction to generate a transaction which we
1536         /// will sign and send to our counterparty.
1537         /// If an Err is returned, it is a ChannelError::Close (for get_outbound_funding_created)
1538         fn build_remote_transaction_keys(&self) -> Result<TxCreationKeys, ChannelError> {
1539                 //TODO: Ensure that the payment_key derived here ends up in the library users' wallet as we
1540                 //may see payments to it!
1541                 let revocation_basepoint = &self.get_holder_pubkeys().revocation_basepoint;
1542                 let htlc_basepoint = &self.get_holder_pubkeys().htlc_basepoint;
1543                 let counterparty_pubkeys = self.get_counterparty_pubkeys();
1544
1545                 Ok(secp_check!(TxCreationKeys::derive_new(&self.secp_ctx, &self.counterparty_cur_commitment_point.unwrap(), &counterparty_pubkeys.delayed_payment_basepoint, &counterparty_pubkeys.htlc_basepoint, revocation_basepoint, htlc_basepoint), "Remote tx keys generation got bogus keys".to_owned()))
1546         }
1547
1548         /// Gets the redeemscript for the funding transaction output (ie the funding transaction output
1549         /// pays to get_funding_redeemscript().to_v0_p2wsh()).
1550         /// Panics if called before accept_channel/new_from_req
1551         pub fn get_funding_redeemscript(&self) -> Script {
1552                 make_funding_redeemscript(&self.get_holder_pubkeys().funding_pubkey, self.counterparty_funding_pubkey())
1553         }
1554
1555         fn get_update_fulfill_htlc<L: Deref>(&mut self, htlc_id_arg: u64, payment_preimage_arg: PaymentPreimage, logger: &L) -> UpdateFulfillFetch where L::Target: Logger {
1556                 // Either ChannelFunded got set (which means it won't be unset) or there is no way any
1557                 // caller thought we could have something claimed (cause we wouldn't have accepted in an
1558                 // incoming HTLC anyway). If we got to ShutdownComplete, callers aren't allowed to call us,
1559                 // either.
1560                 if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
1561                         panic!("Was asked to fulfill an HTLC when channel was not in an operational state");
1562                 }
1563                 assert_eq!(self.channel_state & ChannelState::ShutdownComplete as u32, 0);
1564
1565                 let payment_hash_calc = PaymentHash(Sha256::hash(&payment_preimage_arg.0[..]).into_inner());
1566
1567                 // ChannelManager may generate duplicate claims/fails due to HTLC update events from
1568                 // on-chain ChannelsMonitors during block rescan. Ideally we'd figure out a way to drop
1569                 // these, but for now we just have to treat them as normal.
1570
1571                 let mut pending_idx = core::usize::MAX;
1572                 let mut htlc_value_msat = 0;
1573                 for (idx, htlc) in self.pending_inbound_htlcs.iter().enumerate() {
1574                         if htlc.htlc_id == htlc_id_arg {
1575                                 assert_eq!(htlc.payment_hash, payment_hash_calc);
1576                                 match htlc.state {
1577                                         InboundHTLCState::Committed => {},
1578                                         InboundHTLCState::LocalRemoved(ref reason) => {
1579                                                 if let &InboundHTLCRemovalReason::Fulfill(_) = reason {
1580                                                 } else {
1581                                                         log_warn!(logger, "Have preimage and want to fulfill HTLC with payment hash {} we already failed against channel {}", log_bytes!(htlc.payment_hash.0), log_bytes!(self.channel_id()));
1582                                                         debug_assert!(false, "Tried to fulfill an HTLC that was already failed");
1583                                                 }
1584                                                 return UpdateFulfillFetch::DuplicateClaim {};
1585                                         },
1586                                         _ => {
1587                                                 debug_assert!(false, "Have an inbound HTLC we tried to claim before it was fully committed to");
1588                                                 // Don't return in release mode here so that we can update channel_monitor
1589                                         }
1590                                 }
1591                                 pending_idx = idx;
1592                                 htlc_value_msat = htlc.amount_msat;
1593                                 break;
1594                         }
1595                 }
1596                 if pending_idx == core::usize::MAX {
1597                         #[cfg(any(test, feature = "fuzztarget"))]
1598                         // If we failed to find an HTLC to fulfill, make sure it was previously fulfilled and
1599                         // this is simply a duplicate claim, not previously failed and we lost funds.
1600                         debug_assert!(self.historical_inbound_htlc_fulfills.contains(&htlc_id_arg));
1601                         return UpdateFulfillFetch::DuplicateClaim {};
1602                 }
1603
1604                 // Now update local state:
1605                 //
1606                 // We have to put the payment_preimage in the channel_monitor right away here to ensure we
1607                 // can claim it even if the channel hits the chain before we see their next commitment.
1608                 self.latest_monitor_update_id += 1;
1609                 let monitor_update = ChannelMonitorUpdate {
1610                         update_id: self.latest_monitor_update_id,
1611                         updates: vec![ChannelMonitorUpdateStep::PaymentPreimage {
1612                                 payment_preimage: payment_preimage_arg.clone(),
1613                         }],
1614                 };
1615
1616                 if (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateFailed as u32)) != 0 {
1617                         for pending_update in self.holding_cell_htlc_updates.iter() {
1618                                 match pending_update {
1619                                         &HTLCUpdateAwaitingACK::ClaimHTLC { htlc_id, .. } => {
1620                                                 if htlc_id_arg == htlc_id {
1621                                                         // Make sure we don't leave latest_monitor_update_id incremented here:
1622                                                         self.latest_monitor_update_id -= 1;
1623                                                         #[cfg(any(test, feature = "fuzztarget"))]
1624                                                         debug_assert!(self.historical_inbound_htlc_fulfills.contains(&htlc_id_arg));
1625                                                         return UpdateFulfillFetch::DuplicateClaim {};
1626                                                 }
1627                                         },
1628                                         &HTLCUpdateAwaitingACK::FailHTLC { htlc_id, .. } => {
1629                                                 if htlc_id_arg == htlc_id {
1630                                                         log_warn!(logger, "Have preimage and want to fulfill HTLC with pending failure against channel {}", log_bytes!(self.channel_id()));
1631                                                         // TODO: We may actually be able to switch to a fulfill here, though its
1632                                                         // rare enough it may not be worth the complexity burden.
1633                                                         debug_assert!(false, "Tried to fulfill an HTLC that was already failed");
1634                                                         return UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None };
1635                                                 }
1636                                         },
1637                                         _ => {}
1638                                 }
1639                         }
1640                         log_trace!(logger, "Adding HTLC claim to holding_cell in channel {}! Current state: {}", log_bytes!(self.channel_id()), self.channel_state);
1641                         self.holding_cell_htlc_updates.push(HTLCUpdateAwaitingACK::ClaimHTLC {
1642                                 payment_preimage: payment_preimage_arg, htlc_id: htlc_id_arg,
1643                         });
1644                         #[cfg(any(test, feature = "fuzztarget"))]
1645                         self.historical_inbound_htlc_fulfills.insert(htlc_id_arg);
1646                         return UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None };
1647                 }
1648                 #[cfg(any(test, feature = "fuzztarget"))]
1649                 self.historical_inbound_htlc_fulfills.insert(htlc_id_arg);
1650
1651                 {
1652                         let htlc = &mut self.pending_inbound_htlcs[pending_idx];
1653                         if let InboundHTLCState::Committed = htlc.state {
1654                         } else {
1655                                 debug_assert!(false, "Have an inbound HTLC we tried to claim before it was fully committed to");
1656                                 return UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None };
1657                         }
1658                         log_trace!(logger, "Upgrading HTLC {} to LocalRemoved with a Fulfill in channel {}!", log_bytes!(htlc.payment_hash.0), log_bytes!(self.channel_id));
1659                         htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::Fulfill(payment_preimage_arg.clone()));
1660                 }
1661
1662                 UpdateFulfillFetch::NewClaim {
1663                         monitor_update,
1664                         htlc_value_msat,
1665                         msg: Some(msgs::UpdateFulfillHTLC {
1666                                 channel_id: self.channel_id(),
1667                                 htlc_id: htlc_id_arg,
1668                                 payment_preimage: payment_preimage_arg,
1669                         }),
1670                 }
1671         }
1672
1673         pub fn get_update_fulfill_htlc_and_commit<L: Deref>(&mut self, htlc_id: u64, payment_preimage: PaymentPreimage, logger: &L) -> Result<UpdateFulfillCommitFetch, (ChannelError, ChannelMonitorUpdate)> where L::Target: Logger {
1674                 match self.get_update_fulfill_htlc(htlc_id, payment_preimage, logger) {
1675                         UpdateFulfillFetch::NewClaim { mut monitor_update, htlc_value_msat, msg: Some(update_fulfill_htlc) } => {
1676                                 let (commitment, mut additional_update) = match self.send_commitment_no_status_check(logger) {
1677                                         Err(e) => return Err((e, monitor_update)),
1678                                         Ok(res) => res
1679                                 };
1680                                 // send_commitment_no_status_check may bump latest_monitor_id but we want them to be
1681                                 // strictly increasing by one, so decrement it here.
1682                                 self.latest_monitor_update_id = monitor_update.update_id;
1683                                 monitor_update.updates.append(&mut additional_update.updates);
1684                                 Ok(UpdateFulfillCommitFetch::NewClaim { monitor_update, htlc_value_msat, msgs: Some((update_fulfill_htlc, commitment)) })
1685                         },
1686                         UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None } =>
1687                                 Ok(UpdateFulfillCommitFetch::NewClaim { monitor_update, htlc_value_msat, msgs: None }),
1688                         UpdateFulfillFetch::DuplicateClaim {} => Ok(UpdateFulfillCommitFetch::DuplicateClaim {}),
1689                 }
1690         }
1691
1692         /// We can only have one resolution per HTLC. In some cases around reconnect, we may fulfill
1693         /// an HTLC more than once or fulfill once and then attempt to fail after reconnect. We cannot,
1694         /// however, fail more than once as we wait for an upstream failure to be irrevocably committed
1695         /// before we fail backwards.
1696         /// If we do fail twice, we debug_assert!(false) and return Ok(None). Thus, will always return
1697         /// Ok(_) if debug assertions are turned on or preconditions are met.
1698         pub fn get_update_fail_htlc<L: Deref>(&mut self, htlc_id_arg: u64, err_packet: msgs::OnionErrorPacket, logger: &L) -> Result<Option<msgs::UpdateFailHTLC>, ChannelError> where L::Target: Logger {
1699                 if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
1700                         panic!("Was asked to fail an HTLC when channel was not in an operational state");
1701                 }
1702                 assert_eq!(self.channel_state & ChannelState::ShutdownComplete as u32, 0);
1703
1704                 // ChannelManager may generate duplicate claims/fails due to HTLC update events from
1705                 // on-chain ChannelsMonitors during block rescan. Ideally we'd figure out a way to drop
1706                 // these, but for now we just have to treat them as normal.
1707
1708                 let mut pending_idx = core::usize::MAX;
1709                 for (idx, htlc) in self.pending_inbound_htlcs.iter().enumerate() {
1710                         if htlc.htlc_id == htlc_id_arg {
1711                                 match htlc.state {
1712                                         InboundHTLCState::Committed => {},
1713                                         InboundHTLCState::LocalRemoved(ref reason) => {
1714                                                 if let &InboundHTLCRemovalReason::Fulfill(_) = reason {
1715                                                 } else {
1716                                                         debug_assert!(false, "Tried to fail an HTLC that was already failed");
1717                                                 }
1718                                                 return Ok(None);
1719                                         },
1720                                         _ => {
1721                                                 debug_assert!(false, "Have an inbound HTLC we tried to claim before it was fully committed to");
1722                                                 return Err(ChannelError::Ignore(format!("Unable to find a pending HTLC which matched the given HTLC ID ({})", htlc.htlc_id)));
1723                                         }
1724                                 }
1725                                 pending_idx = idx;
1726                         }
1727                 }
1728                 if pending_idx == core::usize::MAX {
1729                         #[cfg(any(test, feature = "fuzztarget"))]
1730                         // If we failed to find an HTLC to fail, make sure it was previously fulfilled and this
1731                         // is simply a duplicate fail, not previously failed and we failed-back too early.
1732                         debug_assert!(self.historical_inbound_htlc_fulfills.contains(&htlc_id_arg));
1733                         return Ok(None);
1734                 }
1735
1736                 // Now update local state:
1737                 if (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateFailed as u32)) != 0 {
1738                         for pending_update in self.holding_cell_htlc_updates.iter() {
1739                                 match pending_update {
1740                                         &HTLCUpdateAwaitingACK::ClaimHTLC { htlc_id, .. } => {
1741                                                 if htlc_id_arg == htlc_id {
1742                                                         #[cfg(any(test, feature = "fuzztarget"))]
1743                                                         debug_assert!(self.historical_inbound_htlc_fulfills.contains(&htlc_id_arg));
1744                                                         return Ok(None);
1745                                                 }
1746                                         },
1747                                         &HTLCUpdateAwaitingACK::FailHTLC { htlc_id, .. } => {
1748                                                 if htlc_id_arg == htlc_id {
1749                                                         debug_assert!(false, "Tried to fail an HTLC that was already failed");
1750                                                         return Err(ChannelError::Ignore("Unable to find a pending HTLC which matched the given HTLC ID".to_owned()));
1751                                                 }
1752                                         },
1753                                         _ => {}
1754                                 }
1755                         }
1756                         log_trace!(logger, "Placing failure for HTLC ID {} in holding cell in channel {}.", htlc_id_arg, log_bytes!(self.channel_id()));
1757                         self.holding_cell_htlc_updates.push(HTLCUpdateAwaitingACK::FailHTLC {
1758                                 htlc_id: htlc_id_arg,
1759                                 err_packet,
1760                         });
1761                         return Ok(None);
1762                 }
1763
1764                 log_trace!(logger, "Failing HTLC ID {} back with a update_fail_htlc message in channel {}.", htlc_id_arg, log_bytes!(self.channel_id()));
1765                 {
1766                         let htlc = &mut self.pending_inbound_htlcs[pending_idx];
1767                         htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::FailRelay(err_packet.clone()));
1768                 }
1769
1770                 Ok(Some(msgs::UpdateFailHTLC {
1771                         channel_id: self.channel_id(),
1772                         htlc_id: htlc_id_arg,
1773                         reason: err_packet
1774                 }))
1775         }
1776
1777         // Message handlers:
1778
1779         pub fn accept_channel(&mut self, msg: &msgs::AcceptChannel, config: &UserConfig, their_features: &InitFeatures) -> Result<(), ChannelError> {
1780                 // Check sanity of message fields:
1781                 if !self.is_outbound() {
1782                         return Err(ChannelError::Close("Got an accept_channel message from an inbound peer".to_owned()));
1783                 }
1784                 if self.channel_state != ChannelState::OurInitSent as u32 {
1785                         return Err(ChannelError::Close("Got an accept_channel message at a strange time".to_owned()));
1786                 }
1787                 if msg.dust_limit_satoshis > 21000000 * 100000000 {
1788                         return Err(ChannelError::Close(format!("Peer never wants payout outputs? dust_limit_satoshis was {}", msg.dust_limit_satoshis)));
1789                 }
1790                 if msg.channel_reserve_satoshis > self.channel_value_satoshis {
1791                         return Err(ChannelError::Close(format!("Bogus channel_reserve_satoshis ({}). Must not be greater than ({})", msg.channel_reserve_satoshis, self.channel_value_satoshis)));
1792                 }
1793                 if msg.dust_limit_satoshis > self.holder_selected_channel_reserve_satoshis {
1794                         return Err(ChannelError::Close(format!("Dust limit ({}) is bigger than our channel reserve ({})", msg.dust_limit_satoshis, self.holder_selected_channel_reserve_satoshis)));
1795                 }
1796                 let full_channel_value_msat = (self.channel_value_satoshis - msg.channel_reserve_satoshis) * 1000;
1797                 if msg.htlc_minimum_msat >= full_channel_value_msat {
1798                         return Err(ChannelError::Close(format!("Minimum htlc value ({}) is full channel value ({})", msg.htlc_minimum_msat, full_channel_value_msat)));
1799                 }
1800                 let max_delay_acceptable = u16::min(config.peer_channel_config_limits.their_to_self_delay, MAX_LOCAL_BREAKDOWN_TIMEOUT);
1801                 if msg.to_self_delay > max_delay_acceptable {
1802                         return Err(ChannelError::Close(format!("They wanted our payments to be delayed by a needlessly long period. Upper limit: {}. Actual: {}", max_delay_acceptable, msg.to_self_delay)));
1803                 }
1804                 if msg.max_accepted_htlcs < 1 {
1805                         return Err(ChannelError::Close("0 max_accepted_htlcs makes for a useless channel".to_owned()));
1806                 }
1807                 if msg.max_accepted_htlcs > MAX_HTLCS {
1808                         return Err(ChannelError::Close(format!("max_accepted_htlcs was {}. It must not be larger than {}", msg.max_accepted_htlcs, MAX_HTLCS)));
1809                 }
1810
1811                 // Now check against optional parameters as set by config...
1812                 if msg.htlc_minimum_msat > config.peer_channel_config_limits.max_htlc_minimum_msat {
1813                         return Err(ChannelError::Close(format!("htlc_minimum_msat ({}) is higher than the user specified limit ({})", msg.htlc_minimum_msat, config.peer_channel_config_limits.max_htlc_minimum_msat)));
1814                 }
1815                 if msg.max_htlc_value_in_flight_msat < config.peer_channel_config_limits.min_max_htlc_value_in_flight_msat {
1816                         return Err(ChannelError::Close(format!("max_htlc_value_in_flight_msat ({}) is less than the user specified limit ({})", msg.max_htlc_value_in_flight_msat, config.peer_channel_config_limits.min_max_htlc_value_in_flight_msat)));
1817                 }
1818                 if msg.channel_reserve_satoshis > config.peer_channel_config_limits.max_channel_reserve_satoshis {
1819                         return Err(ChannelError::Close(format!("channel_reserve_satoshis ({}) is higher than the user specified limit ({})", msg.channel_reserve_satoshis, config.peer_channel_config_limits.max_channel_reserve_satoshis)));
1820                 }
1821                 if msg.max_accepted_htlcs < config.peer_channel_config_limits.min_max_accepted_htlcs {
1822                         return Err(ChannelError::Close(format!("max_accepted_htlcs ({}) is less than the user specified limit ({})", msg.max_accepted_htlcs, config.peer_channel_config_limits.min_max_accepted_htlcs)));
1823                 }
1824                 if msg.dust_limit_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
1825                         return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is less than the implementation limit ({})", msg.dust_limit_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS)));
1826                 }
1827                 if msg.dust_limit_satoshis > MAX_CHAN_DUST_LIMIT_SATOSHIS {
1828                         return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is greater than the implementation limit ({})", msg.dust_limit_satoshis, MAX_CHAN_DUST_LIMIT_SATOSHIS)));
1829                 }
1830                 if msg.minimum_depth > config.peer_channel_config_limits.max_minimum_depth {
1831                         return Err(ChannelError::Close(format!("We consider the minimum depth to be unreasonably large. Expected minimum: ({}). Actual: ({})", config.peer_channel_config_limits.max_minimum_depth, msg.minimum_depth)));
1832                 }
1833                 if msg.minimum_depth == 0 {
1834                         // Note that if this changes we should update the serialization minimum version to
1835                         // indicate to older clients that they don't understand some features of the current
1836                         // channel.
1837                         return Err(ChannelError::Close("Minimum confirmation depth must be at least 1".to_owned()));
1838                 }
1839
1840                 let counterparty_shutdown_scriptpubkey = if their_features.supports_upfront_shutdown_script() {
1841                         match &msg.shutdown_scriptpubkey {
1842                                 &OptionalField::Present(ref script) => {
1843                                         // Peer is signaling upfront_shutdown and has opt-out with a 0-length script. We don't enforce anything
1844                                         if script.len() == 0 {
1845                                                 None
1846                                         } else {
1847                                                 if !script::is_bolt2_compliant(&script, their_features) {
1848                                                         return Err(ChannelError::Close(format!("Peer is signaling upfront_shutdown but has provided an unacceptable scriptpubkey format: {}", script)));
1849                                                 }
1850                                                 Some(script.clone())
1851                                         }
1852                                 },
1853                                 // Peer is signaling upfront shutdown but don't opt-out with correct mechanism (a.k.a 0-length script). Peer looks buggy, we fail the channel
1854                                 &OptionalField::Absent => {
1855                                         return Err(ChannelError::Close("Peer is signaling upfront_shutdown but we don't get any script. Use 0-length script to opt-out".to_owned()));
1856                                 }
1857                         }
1858                 } else { None };
1859
1860                 self.counterparty_dust_limit_satoshis = msg.dust_limit_satoshis;
1861                 self.counterparty_max_htlc_value_in_flight_msat = cmp::min(msg.max_htlc_value_in_flight_msat, self.channel_value_satoshis * 1000);
1862                 self.counterparty_selected_channel_reserve_satoshis = Some(msg.channel_reserve_satoshis);
1863                 self.counterparty_htlc_minimum_msat = msg.htlc_minimum_msat;
1864                 self.counterparty_max_accepted_htlcs = msg.max_accepted_htlcs;
1865                 self.minimum_depth = Some(msg.minimum_depth);
1866
1867                 let counterparty_pubkeys = ChannelPublicKeys {
1868                         funding_pubkey: msg.funding_pubkey,
1869                         revocation_basepoint: msg.revocation_basepoint,
1870                         payment_point: msg.payment_point,
1871                         delayed_payment_basepoint: msg.delayed_payment_basepoint,
1872                         htlc_basepoint: msg.htlc_basepoint
1873                 };
1874
1875                 self.channel_transaction_parameters.counterparty_parameters = Some(CounterpartyChannelTransactionParameters {
1876                         selected_contest_delay: msg.to_self_delay,
1877                         pubkeys: counterparty_pubkeys,
1878                 });
1879
1880                 self.counterparty_cur_commitment_point = Some(msg.first_per_commitment_point);
1881                 self.counterparty_shutdown_scriptpubkey = counterparty_shutdown_scriptpubkey;
1882
1883                 self.channel_state = ChannelState::OurInitSent as u32 | ChannelState::TheirInitSent as u32;
1884
1885                 Ok(())
1886         }
1887
1888         fn funding_created_signature<L: Deref>(&mut self, sig: &Signature, logger: &L) -> Result<(Txid, CommitmentTransaction, Signature), ChannelError> where L::Target: Logger {
1889                 let funding_script = self.get_funding_redeemscript();
1890
1891                 let keys = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number)?;
1892                 let initial_commitment_tx = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, false, logger).tx;
1893                 {
1894                         let trusted_tx = initial_commitment_tx.trust();
1895                         let initial_commitment_bitcoin_tx = trusted_tx.built_transaction();
1896                         let sighash = initial_commitment_bitcoin_tx.get_sighash_all(&funding_script, self.channel_value_satoshis);
1897                         // They sign the holder commitment transaction...
1898                         log_trace!(logger, "Checking funding_created tx signature {} by key {} against tx {} (sighash {}) with redeemscript {} for channel {}.",
1899                                 log_bytes!(sig.serialize_compact()[..]), log_bytes!(self.counterparty_funding_pubkey().serialize()),
1900                                 encode::serialize_hex(&initial_commitment_bitcoin_tx.transaction), log_bytes!(sighash[..]),
1901                                 encode::serialize_hex(&funding_script), log_bytes!(self.channel_id()));
1902                         secp_check!(self.secp_ctx.verify(&sighash, &sig, self.counterparty_funding_pubkey()), "Invalid funding_created signature from peer".to_owned());
1903                 }
1904
1905                 let counterparty_keys = self.build_remote_transaction_keys()?;
1906                 let counterparty_initial_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;
1907
1908                 let counterparty_trusted_tx = counterparty_initial_commitment_tx.trust();
1909                 let counterparty_initial_bitcoin_tx = counterparty_trusted_tx.built_transaction();
1910                 log_trace!(logger, "Initial counterparty tx for channel {} is: txid {} tx {}",
1911                         log_bytes!(self.channel_id()), counterparty_initial_bitcoin_tx.txid, encode::serialize_hex(&counterparty_initial_bitcoin_tx.transaction));
1912
1913                 let counterparty_signature = self.holder_signer.sign_counterparty_commitment(&counterparty_initial_commitment_tx, &self.secp_ctx)
1914                                 .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?.0;
1915
1916                 // We sign "counterparty" commitment transaction, allowing them to broadcast the tx if they wish.
1917                 Ok((counterparty_initial_bitcoin_tx.txid, initial_commitment_tx, counterparty_signature))
1918         }
1919
1920         fn counterparty_funding_pubkey(&self) -> &PublicKey {
1921                 &self.get_counterparty_pubkeys().funding_pubkey
1922         }
1923
1924         pub fn funding_created<L: Deref>(&mut self, msg: &msgs::FundingCreated, best_block: BestBlock, logger: &L) -> Result<(msgs::FundingSigned, ChannelMonitor<Signer>), ChannelError> where L::Target: Logger {
1925                 if self.is_outbound() {
1926                         return Err(ChannelError::Close("Received funding_created for an outbound channel?".to_owned()));
1927                 }
1928                 if self.channel_state != (ChannelState::OurInitSent as u32 | ChannelState::TheirInitSent as u32) {
1929                         // BOLT 2 says that if we disconnect before we send funding_signed we SHOULD NOT
1930                         // remember the channel, so it's safe to just send an error_message here and drop the
1931                         // channel.
1932                         return Err(ChannelError::Close("Received funding_created after we got the channel!".to_owned()));
1933                 }
1934                 if self.commitment_secrets.get_min_seen_secret() != (1 << 48) ||
1935                                 self.cur_counterparty_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER ||
1936                                 self.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
1937                         panic!("Should not have advanced channel commitment tx numbers prior to funding_created");
1938                 }
1939
1940                 let funding_txo = OutPoint { txid: msg.funding_txid, index: msg.funding_output_index };
1941                 self.channel_transaction_parameters.funding_outpoint = Some(funding_txo);
1942                 // This is an externally observable change before we finish all our checks.  In particular
1943                 // funding_created_signature may fail.
1944                 self.holder_signer.ready_channel(&self.channel_transaction_parameters);
1945
1946                 let (counterparty_initial_commitment_txid, initial_commitment_tx, signature) = match self.funding_created_signature(&msg.signature, logger) {
1947                         Ok(res) => res,
1948                         Err(ChannelError::Close(e)) => {
1949                                 self.channel_transaction_parameters.funding_outpoint = None;
1950                                 return Err(ChannelError::Close(e));
1951                         },
1952                         Err(e) => {
1953                                 // The only error we know how to handle is ChannelError::Close, so we fall over here
1954                                 // to make sure we don't continue with an inconsistent state.
1955                                 panic!("unexpected error type from funding_created_signature {:?}", e);
1956                         }
1957                 };
1958
1959                 let holder_commitment_tx = HolderCommitmentTransaction::new(
1960                         initial_commitment_tx,
1961                         msg.signature,
1962                         Vec::new(),
1963                         &self.get_holder_pubkeys().funding_pubkey,
1964                         self.counterparty_funding_pubkey()
1965                 );
1966
1967                 self.holder_signer.validate_holder_commitment(&holder_commitment_tx)
1968                         .map_err(|_| ChannelError::Close("Failed to validate our commitment".to_owned()))?;
1969
1970                 // Now that we're past error-generating stuff, update our local state:
1971
1972                 let funding_redeemscript = self.get_funding_redeemscript();
1973                 let funding_txo_script = funding_redeemscript.to_v0_p2wsh();
1974                 let obscure_factor = get_commitment_transaction_number_obscure_factor(&self.get_holder_pubkeys().payment_point, &self.get_counterparty_pubkeys().payment_point, self.is_outbound());
1975                 let shutdown_script = self.shutdown_scriptpubkey.clone().map(|script| script.into_inner());
1976                 let channel_monitor = ChannelMonitor::new(self.secp_ctx.clone(), self.holder_signer.clone(),
1977                                                           shutdown_script, self.get_holder_selected_contest_delay(),
1978                                                           &self.destination_script, (funding_txo, funding_txo_script.clone()),
1979                                                           &self.channel_transaction_parameters,
1980                                                           funding_redeemscript.clone(), self.channel_value_satoshis,
1981                                                           obscure_factor,
1982                                                           holder_commitment_tx, best_block);
1983
1984                 channel_monitor.provide_latest_counterparty_commitment_tx(counterparty_initial_commitment_txid, Vec::new(), self.cur_counterparty_commitment_transaction_number, self.counterparty_cur_commitment_point.unwrap(), logger);
1985
1986                 self.channel_state = ChannelState::FundingSent as u32;
1987                 self.channel_id = funding_txo.to_channel_id();
1988                 self.cur_counterparty_commitment_transaction_number -= 1;
1989                 self.cur_holder_commitment_transaction_number -= 1;
1990
1991                 log_info!(logger, "Generated funding_signed for peer for channel {}", log_bytes!(self.channel_id()));
1992
1993                 Ok((msgs::FundingSigned {
1994                         channel_id: self.channel_id,
1995                         signature
1996                 }, channel_monitor))
1997         }
1998
1999         /// Handles a funding_signed message from the remote end.
2000         /// If this call is successful, broadcast the funding transaction (and not before!)
2001         pub fn funding_signed<L: Deref>(&mut self, msg: &msgs::FundingSigned, best_block: BestBlock, logger: &L) -> Result<(ChannelMonitor<Signer>, Transaction), ChannelError> where L::Target: Logger {
2002                 if !self.is_outbound() {
2003                         return Err(ChannelError::Close("Received funding_signed for an inbound channel?".to_owned()));
2004                 }
2005                 if self.channel_state & !(ChannelState::MonitorUpdateFailed as u32) != ChannelState::FundingCreated as u32 {
2006                         return Err(ChannelError::Close("Received funding_signed in strange state!".to_owned()));
2007                 }
2008                 if self.commitment_secrets.get_min_seen_secret() != (1 << 48) ||
2009                                 self.cur_counterparty_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER ||
2010                                 self.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
2011                         panic!("Should not have advanced channel commitment tx numbers prior to funding_created");
2012                 }
2013
2014                 let funding_script = self.get_funding_redeemscript();
2015
2016                 let counterparty_keys = self.build_remote_transaction_keys()?;
2017                 let counterparty_initial_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;
2018                 let counterparty_trusted_tx = counterparty_initial_commitment_tx.trust();
2019                 let counterparty_initial_bitcoin_tx = counterparty_trusted_tx.built_transaction();
2020
2021                 log_trace!(logger, "Initial counterparty tx for channel {} is: txid {} tx {}",
2022                         log_bytes!(self.channel_id()), counterparty_initial_bitcoin_tx.txid, encode::serialize_hex(&counterparty_initial_bitcoin_tx.transaction));
2023
2024                 let holder_signer = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number)?;
2025                 let initial_commitment_tx = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &holder_signer, true, false, logger).tx;
2026                 {
2027                         let trusted_tx = initial_commitment_tx.trust();
2028                         let initial_commitment_bitcoin_tx = trusted_tx.built_transaction();
2029                         let sighash = initial_commitment_bitcoin_tx.get_sighash_all(&funding_script, self.channel_value_satoshis);
2030                         // They sign our commitment transaction, allowing us to broadcast the tx if we wish.
2031                         if let Err(_) = self.secp_ctx.verify(&sighash, &msg.signature, &self.get_counterparty_pubkeys().funding_pubkey) {
2032                                 return Err(ChannelError::Close("Invalid funding_signed signature from peer".to_owned()));
2033                         }
2034                 }
2035
2036                 let holder_commitment_tx = HolderCommitmentTransaction::new(
2037                         initial_commitment_tx,
2038                         msg.signature,
2039                         Vec::new(),
2040                         &self.get_holder_pubkeys().funding_pubkey,
2041                         self.counterparty_funding_pubkey()
2042                 );
2043
2044                 self.holder_signer.validate_holder_commitment(&holder_commitment_tx)
2045                         .map_err(|_| ChannelError::Close("Failed to validate our commitment".to_owned()))?;
2046
2047
2048                 let funding_redeemscript = self.get_funding_redeemscript();
2049                 let funding_txo = self.get_funding_txo().unwrap();
2050                 let funding_txo_script = funding_redeemscript.to_v0_p2wsh();
2051                 let obscure_factor = get_commitment_transaction_number_obscure_factor(&self.get_holder_pubkeys().payment_point, &self.get_counterparty_pubkeys().payment_point, self.is_outbound());
2052                 let shutdown_script = self.shutdown_scriptpubkey.clone().map(|script| script.into_inner());
2053                 let channel_monitor = ChannelMonitor::new(self.secp_ctx.clone(), self.holder_signer.clone(),
2054                                                           shutdown_script, self.get_holder_selected_contest_delay(),
2055                                                           &self.destination_script, (funding_txo, funding_txo_script),
2056                                                           &self.channel_transaction_parameters,
2057                                                           funding_redeemscript.clone(), self.channel_value_satoshis,
2058                                                           obscure_factor,
2059                                                           holder_commitment_tx, best_block);
2060
2061                 channel_monitor.provide_latest_counterparty_commitment_tx(counterparty_initial_bitcoin_tx.txid, Vec::new(), self.cur_counterparty_commitment_transaction_number, self.counterparty_cur_commitment_point.unwrap(), logger);
2062
2063                 assert_eq!(self.channel_state & (ChannelState::MonitorUpdateFailed as u32), 0); // We have no had any monitor(s) yet to fail update!
2064                 self.channel_state = ChannelState::FundingSent as u32;
2065                 self.cur_holder_commitment_transaction_number -= 1;
2066                 self.cur_counterparty_commitment_transaction_number -= 1;
2067
2068                 log_info!(logger, "Received funding_signed from peer for channel {}", log_bytes!(self.channel_id()));
2069
2070                 Ok((channel_monitor, self.funding_transaction.as_ref().cloned().unwrap()))
2071         }
2072
2073         /// Handles a funding_locked message from our peer. If we've already sent our funding_locked
2074         /// and the channel is now usable (and public), this may generate an announcement_signatures to
2075         /// reply with.
2076         pub fn funding_locked<L: Deref>(&mut self, msg: &msgs::FundingLocked, node_pk: PublicKey, genesis_block_hash: BlockHash, best_block: &BestBlock, logger: &L) -> Result<Option<msgs::AnnouncementSignatures>, ChannelError> where L::Target: Logger {
2077                 if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
2078                         self.workaround_lnd_bug_4006 = Some(msg.clone());
2079                         return Err(ChannelError::Ignore("Peer sent funding_locked when we needed a channel_reestablish. The peer is likely lnd, see https://github.com/lightningnetwork/lnd/issues/4006".to_owned()));
2080                 }
2081
2082                 if let Some(scid_alias) = msg.short_channel_id_alias {
2083                         if Some(scid_alias.0) != self.short_channel_id {
2084                                 // The scid alias provided can be used to route payments *from* our counterparty,
2085                                 // i.e. can be used for inbound payments and provided in invoices, but is not used
2086                                 // whrn routing outbound payments.
2087                                 self.latest_inbound_scid_alias = Some(scid_alias.0);
2088                         }
2089                 }
2090
2091                 let non_shutdown_state = self.channel_state & (!MULTI_STATE_FLAGS);
2092
2093                 if non_shutdown_state == ChannelState::FundingSent as u32 {
2094                         self.channel_state |= ChannelState::TheirFundingLocked as u32;
2095                 } else if non_shutdown_state == (ChannelState::FundingSent as u32 | ChannelState::OurFundingLocked as u32) {
2096                         self.channel_state = ChannelState::ChannelFunded as u32 | (self.channel_state & MULTI_STATE_FLAGS);
2097                         self.update_time_counter += 1;
2098                 } else if self.channel_state & (ChannelState::ChannelFunded as u32) != 0 ||
2099                         // If we reconnected before sending our funding locked they may still resend theirs:
2100                         (self.channel_state & (ChannelState::FundingSent as u32 | ChannelState::TheirFundingLocked as u32) ==
2101                                               (ChannelState::FundingSent as u32 | ChannelState::TheirFundingLocked as u32))
2102                 {
2103                         // They probably disconnected/reconnected and re-sent the funding_locked, which is
2104                         // required, or we're getting a fresh SCID alias.
2105                         let expected_point =
2106                                 if self.cur_counterparty_commitment_transaction_number == INITIAL_COMMITMENT_NUMBER - 1 {
2107                                         // If they haven't ever sent an updated point, the point they send should match
2108                                         // the current one.
2109                                         self.counterparty_cur_commitment_point
2110                                 } else {
2111                                         // If they have sent updated points, funding_locked is always supposed to match
2112                                         // their "first" point, which we re-derive here.
2113                                         self.commitment_secrets.get_secret(INITIAL_COMMITMENT_NUMBER - 1)
2114                                                 .map(|secret| SecretKey::from_slice(&secret).ok()).flatten()
2115                                                 .map(|sk| PublicKey::from_secret_key(&self.secp_ctx, &sk))
2116                                 };
2117 if self.commitment_secrets.get_secret(INITIAL_COMMITMENT_NUMBER - 1).is_some() {
2118 let cv = self.commitment_secrets.get_secret(INITIAL_COMMITMENT_NUMBER - 1)
2119         .map(|secret| SecretKey::from_slice(&secret).ok()).flatten()
2120         .map(|sk| PublicKey::from_secret_key(&self.secp_ctx, &sk));
2121 assert_eq!(cv, expected_point);
2122 panic!();
2123 }
2124                         if expected_point != Some(msg.next_per_commitment_point) {
2125                                 return Err(ChannelError::Close("Peer sent a reconnect funding_locked with a different point".to_owned()));
2126                         }
2127                         return Ok(None);
2128                 } else {
2129                         return Err(ChannelError::Close("Peer sent a funding_locked at a strange time".to_owned()));
2130                 }
2131
2132                 self.counterparty_prev_commitment_point = self.counterparty_cur_commitment_point;
2133                 self.counterparty_cur_commitment_point = Some(msg.next_per_commitment_point);
2134
2135                 log_info!(logger, "Received funding_locked from peer for channel {}", log_bytes!(self.channel_id()));
2136
2137                 Ok(self.get_announcement_sigs(node_pk, genesis_block_hash, best_block.height(), logger))
2138         }
2139
2140         /// Returns transaction if there is pending funding transaction that is yet to broadcast
2141         pub fn unbroadcasted_funding(&self) -> Option<Transaction> {
2142                  if self.channel_state & (ChannelState::FundingCreated as u32) != 0 {
2143                          self.funding_transaction.clone()
2144                  } else {
2145                          None
2146                  }
2147         }
2148
2149         /// Returns a HTLCStats about inbound pending htlcs
2150         fn get_inbound_pending_htlc_stats(&self, outbound_feerate_update: Option<u32>) -> HTLCStats {
2151                 let mut stats = HTLCStats {
2152                         pending_htlcs: self.pending_inbound_htlcs.len() as u32,
2153                         pending_htlcs_value_msat: 0,
2154                         on_counterparty_tx_dust_exposure_msat: 0,
2155                         on_holder_tx_dust_exposure_msat: 0,
2156                         holding_cell_msat: 0,
2157                         on_holder_tx_holding_cell_htlcs_count: 0,
2158                 };
2159
2160                 let counterparty_dust_limit_timeout_sat = (self.get_dust_buffer_feerate(outbound_feerate_update) as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000) + self.counterparty_dust_limit_satoshis;
2161                 let holder_dust_limit_success_sat = (self.get_dust_buffer_feerate(outbound_feerate_update) as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000) + self.holder_dust_limit_satoshis;
2162                 for ref htlc in self.pending_inbound_htlcs.iter() {
2163                         stats.pending_htlcs_value_msat += htlc.amount_msat;
2164                         if htlc.amount_msat / 1000 < counterparty_dust_limit_timeout_sat {
2165                                 stats.on_counterparty_tx_dust_exposure_msat += htlc.amount_msat;
2166                         }
2167                         if htlc.amount_msat / 1000 < holder_dust_limit_success_sat {
2168                                 stats.on_holder_tx_dust_exposure_msat += htlc.amount_msat;
2169                         }
2170                 }
2171                 stats
2172         }
2173
2174         /// Returns a HTLCStats about pending outbound htlcs, *including* pending adds in our holding cell.
2175         fn get_outbound_pending_htlc_stats(&self, outbound_feerate_update: Option<u32>) -> HTLCStats {
2176                 let mut stats = HTLCStats {
2177                         pending_htlcs: self.pending_outbound_htlcs.len() as u32,
2178                         pending_htlcs_value_msat: 0,
2179                         on_counterparty_tx_dust_exposure_msat: 0,
2180                         on_holder_tx_dust_exposure_msat: 0,
2181                         holding_cell_msat: 0,
2182                         on_holder_tx_holding_cell_htlcs_count: 0,
2183                 };
2184
2185                 let counterparty_dust_limit_success_sat = (self.get_dust_buffer_feerate(outbound_feerate_update) as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000) + self.counterparty_dust_limit_satoshis;
2186                 let holder_dust_limit_timeout_sat = (self.get_dust_buffer_feerate(outbound_feerate_update) as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000) + self.holder_dust_limit_satoshis;
2187                 for ref htlc in self.pending_outbound_htlcs.iter() {
2188                         stats.pending_htlcs_value_msat += htlc.amount_msat;
2189                         if htlc.amount_msat / 1000 < counterparty_dust_limit_success_sat {
2190                                 stats.on_counterparty_tx_dust_exposure_msat += htlc.amount_msat;
2191                         }
2192                         if htlc.amount_msat / 1000 < holder_dust_limit_timeout_sat {
2193                                 stats.on_holder_tx_dust_exposure_msat += htlc.amount_msat;
2194                         }
2195                 }
2196
2197                 for update in self.holding_cell_htlc_updates.iter() {
2198                         if let &HTLCUpdateAwaitingACK::AddHTLC { ref amount_msat, .. } = update {
2199                                 stats.pending_htlcs += 1;
2200                                 stats.pending_htlcs_value_msat += amount_msat;
2201                                 stats.holding_cell_msat += amount_msat;
2202                                 if *amount_msat / 1000 < counterparty_dust_limit_success_sat {
2203                                         stats.on_counterparty_tx_dust_exposure_msat += amount_msat;
2204                                 }
2205                                 if *amount_msat / 1000 < holder_dust_limit_timeout_sat {
2206                                         stats.on_holder_tx_dust_exposure_msat += amount_msat;
2207                                 } else {
2208                                         stats.on_holder_tx_holding_cell_htlcs_count += 1;
2209                                 }
2210                         }
2211                 }
2212                 stats
2213         }
2214
2215         /// Get the available (ie not including pending HTLCs) inbound and outbound balance in msat.
2216         /// Doesn't bother handling the
2217         /// if-we-removed-it-already-but-haven't-fully-resolved-they-can-still-send-an-inbound-HTLC
2218         /// corner case properly.
2219         /// The channel reserve is subtracted from each balance.
2220         /// See also [`Channel::get_balance_msat`]
2221         pub fn get_inbound_outbound_available_balance_msat(&self) -> (u64, u64) {
2222                 // Note that we have to handle overflow due to the above case.
2223                 (
2224                         cmp::max(self.channel_value_satoshis as i64 * 1000
2225                                 - self.value_to_self_msat as i64
2226                                 - self.get_inbound_pending_htlc_stats(None).pending_htlcs_value_msat as i64
2227                                 - self.holder_selected_channel_reserve_satoshis as i64 * 1000,
2228                         0) as u64,
2229                         cmp::max(self.value_to_self_msat as i64
2230                                 - self.get_outbound_pending_htlc_stats(None).pending_htlcs_value_msat as i64
2231                                 - self.counterparty_selected_channel_reserve_satoshis.unwrap_or(0) as i64 * 1000,
2232                         0) as u64
2233                 )
2234         }
2235
2236         /// Get our total balance in msat.
2237         /// This is the amount that would go to us if we close the channel, ignoring any on-chain fees.
2238         /// See also [`Channel::get_inbound_outbound_available_balance_msat`]
2239         pub fn get_balance_msat(&self) -> u64 {
2240                 self.value_to_self_msat
2241                         - self.get_outbound_pending_htlc_stats(None).pending_htlcs_value_msat
2242         }
2243
2244         pub fn get_holder_counterparty_selected_channel_reserve_satoshis(&self) -> (u64, Option<u64>) {
2245                 (self.holder_selected_channel_reserve_satoshis, self.counterparty_selected_channel_reserve_satoshis)
2246         }
2247
2248         // Get the fee cost in MSATS of a commitment tx with a given number of HTLC outputs.
2249         // Note that num_htlcs should not include dust HTLCs.
2250         fn commit_tx_fee_msat(feerate_per_kw: u32, num_htlcs: usize) -> u64 {
2251                 // Note that we need to divide before multiplying to round properly,
2252                 // since the lowest denomination of bitcoin on-chain is the satoshi.
2253                 (COMMITMENT_TX_BASE_WEIGHT + num_htlcs as u64 * COMMITMENT_TX_WEIGHT_PER_HTLC) * feerate_per_kw as u64 / 1000 * 1000
2254         }
2255
2256         // Get the fee cost in SATS of a commitment tx with a given number of HTLC outputs.
2257         // Note that num_htlcs should not include dust HTLCs.
2258         #[inline]
2259         fn commit_tx_fee_sat(feerate_per_kw: u32, num_htlcs: usize) -> u64 {
2260                 feerate_per_kw as u64 * (COMMITMENT_TX_BASE_WEIGHT + num_htlcs as u64 * COMMITMENT_TX_WEIGHT_PER_HTLC) / 1000
2261         }
2262
2263         // Get the commitment tx fee for the local's (i.e. our) next commitment transaction based on the
2264         // number of pending HTLCs that are on track to be in our next commitment tx, plus an additional
2265         // HTLC if `fee_spike_buffer_htlc` is Some, plus a new HTLC given by `new_htlc_amount`. Dust HTLCs
2266         // are excluded.
2267         fn next_local_commit_tx_fee_msat(&self, htlc: HTLCCandidate, fee_spike_buffer_htlc: Option<()>) -> u64 {
2268                 assert!(self.is_outbound());
2269
2270                 let real_dust_limit_success_sat = (self.feerate_per_kw as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000) + self.holder_dust_limit_satoshis;
2271                 let real_dust_limit_timeout_sat = (self.feerate_per_kw as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000) + self.holder_dust_limit_satoshis;
2272
2273                 let mut addl_htlcs = 0;
2274                 if fee_spike_buffer_htlc.is_some() { addl_htlcs += 1; }
2275                 match htlc.origin {
2276                         HTLCInitiator::LocalOffered => {
2277                                 if htlc.amount_msat / 1000 >= real_dust_limit_timeout_sat {
2278                                         addl_htlcs += 1;
2279                                 }
2280                         },
2281                         HTLCInitiator::RemoteOffered => {
2282                                 if htlc.amount_msat / 1000 >= real_dust_limit_success_sat {
2283                                         addl_htlcs += 1;
2284                                 }
2285                         }
2286                 }
2287
2288                 let mut included_htlcs = 0;
2289                 for ref htlc in self.pending_inbound_htlcs.iter() {
2290                         if htlc.amount_msat / 1000 < real_dust_limit_success_sat {
2291                                 continue
2292                         }
2293                         // We include LocalRemoved HTLCs here because we may still need to broadcast a commitment
2294                         // transaction including this HTLC if it times out before they RAA.
2295                         included_htlcs += 1;
2296                 }
2297
2298                 for ref htlc in self.pending_outbound_htlcs.iter() {
2299                         if htlc.amount_msat / 1000 < real_dust_limit_timeout_sat {
2300                                 continue
2301                         }
2302                         match htlc.state {
2303                                 OutboundHTLCState::LocalAnnounced {..} => included_htlcs += 1,
2304                                 OutboundHTLCState::Committed => included_htlcs += 1,
2305                                 OutboundHTLCState::RemoteRemoved {..} => included_htlcs += 1,
2306                                 // We don't include AwaitingRemoteRevokeToRemove HTLCs because our next commitment
2307                                 // transaction won't be generated until they send us their next RAA, which will mean
2308                                 // dropping any HTLCs in this state.
2309                                 _ => {},
2310                         }
2311                 }
2312
2313                 for htlc in self.holding_cell_htlc_updates.iter() {
2314                         match htlc {
2315                                 &HTLCUpdateAwaitingACK::AddHTLC { amount_msat, .. } => {
2316                                         if amount_msat / 1000 < real_dust_limit_timeout_sat {
2317                                                 continue
2318                                         }
2319                                         included_htlcs += 1
2320                                 },
2321                                 _ => {}, // Don't include claims/fails that are awaiting ack, because once we get the
2322                                          // ack we're guaranteed to never include them in commitment txs anymore.
2323                         }
2324                 }
2325
2326                 let num_htlcs = included_htlcs + addl_htlcs;
2327                 let res = Self::commit_tx_fee_msat(self.feerate_per_kw, num_htlcs);
2328                 #[cfg(any(test, feature = "fuzztarget"))]
2329                 {
2330                         let mut fee = res;
2331                         if fee_spike_buffer_htlc.is_some() {
2332                                 fee = Self::commit_tx_fee_msat(self.feerate_per_kw, num_htlcs - 1);
2333                         }
2334                         let total_pending_htlcs = self.pending_inbound_htlcs.len() + self.pending_outbound_htlcs.len()
2335                                 + self.holding_cell_htlc_updates.len();
2336                         let commitment_tx_info = CommitmentTxInfoCached {
2337                                 fee,
2338                                 total_pending_htlcs,
2339                                 next_holder_htlc_id: match htlc.origin {
2340                                         HTLCInitiator::LocalOffered => self.next_holder_htlc_id + 1,
2341                                         HTLCInitiator::RemoteOffered => self.next_holder_htlc_id,
2342                                 },
2343                                 next_counterparty_htlc_id: match htlc.origin {
2344                                         HTLCInitiator::LocalOffered => self.next_counterparty_htlc_id,
2345                                         HTLCInitiator::RemoteOffered => self.next_counterparty_htlc_id + 1,
2346                                 },
2347                                 feerate: self.feerate_per_kw,
2348                         };
2349                         *self.next_local_commitment_tx_fee_info_cached.lock().unwrap() = Some(commitment_tx_info);
2350                 }
2351                 res
2352         }
2353
2354         // Get the commitment tx fee for the remote's next commitment transaction based on the number of
2355         // pending HTLCs that are on track to be in their next commitment tx, plus an additional HTLC if
2356         // `fee_spike_buffer_htlc` is Some, plus a new HTLC given by `new_htlc_amount`. Dust HTLCs are
2357         // excluded.
2358         fn next_remote_commit_tx_fee_msat(&self, htlc: HTLCCandidate, fee_spike_buffer_htlc: Option<()>) -> u64 {
2359                 assert!(!self.is_outbound());
2360
2361                 let real_dust_limit_success_sat = (self.feerate_per_kw as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000) + self.counterparty_dust_limit_satoshis;
2362                 let real_dust_limit_timeout_sat = (self.feerate_per_kw as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000) + self.counterparty_dust_limit_satoshis;
2363
2364                 let mut addl_htlcs = 0;
2365                 if fee_spike_buffer_htlc.is_some() { addl_htlcs += 1; }
2366                 match htlc.origin {
2367                         HTLCInitiator::LocalOffered => {
2368                                 if htlc.amount_msat / 1000 >= real_dust_limit_success_sat {
2369                                         addl_htlcs += 1;
2370                                 }
2371                         },
2372                         HTLCInitiator::RemoteOffered => {
2373                                 if htlc.amount_msat / 1000 >= real_dust_limit_timeout_sat {
2374                                         addl_htlcs += 1;
2375                                 }
2376                         }
2377                 }
2378
2379                 // When calculating the set of HTLCs which will be included in their next commitment_signed, all
2380                 // non-dust inbound HTLCs are included (as all states imply it will be included) and only
2381                 // committed outbound HTLCs, see below.
2382                 let mut included_htlcs = 0;
2383                 for ref htlc in self.pending_inbound_htlcs.iter() {
2384                         if htlc.amount_msat / 1000 <= real_dust_limit_timeout_sat {
2385                                 continue
2386                         }
2387                         included_htlcs += 1;
2388                 }
2389
2390                 for ref htlc in self.pending_outbound_htlcs.iter() {
2391                         if htlc.amount_msat / 1000 <= real_dust_limit_success_sat {
2392                                 continue
2393                         }
2394                         // We only include outbound HTLCs if it will not be included in their next commitment_signed,
2395                         // i.e. if they've responded to us with an RAA after announcement.
2396                         match htlc.state {
2397                                 OutboundHTLCState::Committed => included_htlcs += 1,
2398                                 OutboundHTLCState::RemoteRemoved {..} => included_htlcs += 1,
2399                                 OutboundHTLCState::LocalAnnounced { .. } => included_htlcs += 1,
2400                                 _ => {},
2401                         }
2402                 }
2403
2404                 let num_htlcs = included_htlcs + addl_htlcs;
2405                 let res = Self::commit_tx_fee_msat(self.feerate_per_kw, num_htlcs);
2406                 #[cfg(any(test, feature = "fuzztarget"))]
2407                 {
2408                         let mut fee = res;
2409                         if fee_spike_buffer_htlc.is_some() {
2410                                 fee = Self::commit_tx_fee_msat(self.feerate_per_kw, num_htlcs - 1);
2411                         }
2412                         let total_pending_htlcs = self.pending_inbound_htlcs.len() + self.pending_outbound_htlcs.len();
2413                         let commitment_tx_info = CommitmentTxInfoCached {
2414                                 fee,
2415                                 total_pending_htlcs,
2416                                 next_holder_htlc_id: match htlc.origin {
2417                                         HTLCInitiator::LocalOffered => self.next_holder_htlc_id + 1,
2418                                         HTLCInitiator::RemoteOffered => self.next_holder_htlc_id,
2419                                 },
2420                                 next_counterparty_htlc_id: match htlc.origin {
2421                                         HTLCInitiator::LocalOffered => self.next_counterparty_htlc_id,
2422                                         HTLCInitiator::RemoteOffered => self.next_counterparty_htlc_id + 1,
2423                                 },
2424                                 feerate: self.feerate_per_kw,
2425                         };
2426                         *self.next_remote_commitment_tx_fee_info_cached.lock().unwrap() = Some(commitment_tx_info);
2427                 }
2428                 res
2429         }
2430
2431         pub fn update_add_htlc<F, L: Deref>(&mut self, msg: &msgs::UpdateAddHTLC, mut pending_forward_status: PendingHTLCStatus, create_pending_htlc_status: F, logger: &L) -> Result<(), ChannelError>
2432         where F: for<'a> Fn(&'a Self, PendingHTLCStatus, u16) -> PendingHTLCStatus, L::Target: Logger {
2433                 // We can't accept HTLCs sent after we've sent a shutdown.
2434                 let local_sent_shutdown = (self.channel_state & (ChannelState::ChannelFunded as u32 | ChannelState::LocalShutdownSent as u32)) != (ChannelState::ChannelFunded as u32);
2435                 if local_sent_shutdown {
2436                         pending_forward_status = create_pending_htlc_status(self, pending_forward_status, 0x4000|8);
2437                 }
2438                 // If the remote has sent a shutdown prior to adding this HTLC, then they are in violation of the spec.
2439                 let remote_sent_shutdown = (self.channel_state & (ChannelState::ChannelFunded as u32 | ChannelState::RemoteShutdownSent as u32)) != (ChannelState::ChannelFunded as u32);
2440                 if remote_sent_shutdown {
2441                         return Err(ChannelError::Close("Got add HTLC message when channel was not in an operational state".to_owned()));
2442                 }
2443                 if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
2444                         return Err(ChannelError::Close("Peer sent update_add_htlc when we needed a channel_reestablish".to_owned()));
2445                 }
2446                 if msg.amount_msat > self.channel_value_satoshis * 1000 {
2447                         return Err(ChannelError::Close("Remote side tried to send more than the total value of the channel".to_owned()));
2448                 }
2449                 if msg.amount_msat == 0 {
2450                         return Err(ChannelError::Close("Remote side tried to send a 0-msat HTLC".to_owned()));
2451                 }
2452                 if msg.amount_msat < self.holder_htlc_minimum_msat {
2453                         return Err(ChannelError::Close(format!("Remote side tried to send less than our minimum HTLC value. Lower limit: ({}). Actual: ({})", self.holder_htlc_minimum_msat, msg.amount_msat)));
2454                 }
2455
2456                 let inbound_stats = self.get_inbound_pending_htlc_stats(None);
2457                 let outbound_stats = self.get_outbound_pending_htlc_stats(None);
2458                 if inbound_stats.pending_htlcs + 1 > OUR_MAX_HTLCS as u32 {
2459                         return Err(ChannelError::Close(format!("Remote tried to push more than our max accepted HTLCs ({})", OUR_MAX_HTLCS)));
2460                 }
2461                 if inbound_stats.pending_htlcs_value_msat + msg.amount_msat > self.holder_max_htlc_value_in_flight_msat {
2462                         return Err(ChannelError::Close(format!("Remote HTLC add would put them over our max HTLC value ({})", self.holder_max_htlc_value_in_flight_msat)));
2463                 }
2464                 // Check holder_selected_channel_reserve_satoshis (we're getting paid, so they have to at least meet
2465                 // the reserve_satoshis we told them to always have as direct payment so that they lose
2466                 // something if we punish them for broadcasting an old state).
2467                 // Note that we don't really care about having a small/no to_remote output in our local
2468                 // commitment transactions, as the purpose of the channel reserve is to ensure we can
2469                 // punish *them* if they misbehave, so we discount any outbound HTLCs which will not be
2470                 // present in the next commitment transaction we send them (at least for fulfilled ones,
2471                 // failed ones won't modify value_to_self).
2472                 // Note that we will send HTLCs which another instance of rust-lightning would think
2473                 // violate the reserve value if we do not do this (as we forget inbound HTLCs from the
2474                 // Channel state once they will not be present in the next received commitment
2475                 // transaction).
2476                 let mut removed_outbound_total_msat = 0;
2477                 for ref htlc in self.pending_outbound_htlcs.iter() {
2478                         if let OutboundHTLCState::AwaitingRemoteRevokeToRemove(None) = htlc.state {
2479                                 removed_outbound_total_msat += htlc.amount_msat;
2480                         } else if let OutboundHTLCState::AwaitingRemovedRemoteRevoke(None) = htlc.state {
2481                                 removed_outbound_total_msat += htlc.amount_msat;
2482                         }
2483                 }
2484
2485                 let exposure_dust_limit_timeout_sats = (self.get_dust_buffer_feerate(None) as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000) + self.counterparty_dust_limit_satoshis;
2486                 if msg.amount_msat / 1000 < exposure_dust_limit_timeout_sats {
2487                         let on_counterparty_tx_dust_htlc_exposure_msat = inbound_stats.on_counterparty_tx_dust_exposure_msat + outbound_stats.on_counterparty_tx_dust_exposure_msat + msg.amount_msat;
2488                         if on_counterparty_tx_dust_htlc_exposure_msat > self.get_max_dust_htlc_exposure_msat() {
2489                                 log_info!(logger, "Cannot accept value that would put our exposure to dust HTLCs at {} over the limit {} on counterparty commitment tx",
2490                                         on_counterparty_tx_dust_htlc_exposure_msat, self.get_max_dust_htlc_exposure_msat());
2491                                 pending_forward_status = create_pending_htlc_status(self, pending_forward_status, 0x1000|7);
2492                         }
2493                 }
2494
2495                 let exposure_dust_limit_success_sats = (self.get_dust_buffer_feerate(None) as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000) + self.holder_dust_limit_satoshis;
2496                 if msg.amount_msat / 1000 < exposure_dust_limit_success_sats {
2497                         let on_holder_tx_dust_htlc_exposure_msat = inbound_stats.on_holder_tx_dust_exposure_msat + outbound_stats.on_holder_tx_dust_exposure_msat + msg.amount_msat;
2498                         if on_holder_tx_dust_htlc_exposure_msat > self.get_max_dust_htlc_exposure_msat() {
2499                                 log_info!(logger, "Cannot accept value that would put our exposure to dust HTLCs at {} over the limit {} on holder commitment tx",
2500                                         on_holder_tx_dust_htlc_exposure_msat, self.get_max_dust_htlc_exposure_msat());
2501                                 pending_forward_status = create_pending_htlc_status(self, pending_forward_status, 0x1000|7);
2502                         }
2503                 }
2504
2505                 let pending_value_to_self_msat =
2506                         self.value_to_self_msat + inbound_stats.pending_htlcs_value_msat - removed_outbound_total_msat;
2507                 let pending_remote_value_msat =
2508                         self.channel_value_satoshis * 1000 - pending_value_to_self_msat;
2509                 if pending_remote_value_msat < msg.amount_msat {
2510                         return Err(ChannelError::Close("Remote HTLC add would overdraw remaining funds".to_owned()));
2511                 }
2512
2513                 // Check that the remote can afford to pay for this HTLC on-chain at the current
2514                 // feerate_per_kw, while maintaining their channel reserve (as required by the spec).
2515                 let remote_commit_tx_fee_msat = if self.is_outbound() { 0 } else {
2516                         let htlc_candidate = HTLCCandidate::new(msg.amount_msat, HTLCInitiator::RemoteOffered);
2517                         self.next_remote_commit_tx_fee_msat(htlc_candidate, None) // Don't include the extra fee spike buffer HTLC in calculations
2518                 };
2519                 if pending_remote_value_msat - msg.amount_msat < remote_commit_tx_fee_msat {
2520                         return Err(ChannelError::Close("Remote HTLC add would not leave enough to pay for fees".to_owned()));
2521                 };
2522
2523                 if pending_remote_value_msat - msg.amount_msat - remote_commit_tx_fee_msat < self.holder_selected_channel_reserve_satoshis * 1000 {
2524                         return Err(ChannelError::Close("Remote HTLC add would put them under remote reserve value".to_owned()));
2525                 }
2526
2527                 if !self.is_outbound() {
2528                         // `2 *` and `Some(())` is for the fee spike buffer we keep for the remote. This deviates from
2529                         // the spec because in the spec, the fee spike buffer requirement doesn't exist on the
2530                         // receiver's side, only on the sender's.
2531                         // Note that when we eventually remove support for fee updates and switch to anchor output
2532                         // fees, we will drop the `2 *`, since we no longer be as sensitive to fee spikes. But, keep
2533                         // the extra htlc when calculating the next remote commitment transaction fee as we should
2534                         // still be able to afford adding this HTLC plus one more future HTLC, regardless of being
2535                         // sensitive to fee spikes.
2536                         let htlc_candidate = HTLCCandidate::new(msg.amount_msat, HTLCInitiator::RemoteOffered);
2537                         let remote_fee_cost_incl_stuck_buffer_msat = 2 * self.next_remote_commit_tx_fee_msat(htlc_candidate, Some(()));
2538                         if pending_remote_value_msat - msg.amount_msat - self.holder_selected_channel_reserve_satoshis * 1000 < remote_fee_cost_incl_stuck_buffer_msat {
2539                                 // Note that if the pending_forward_status is not updated here, then it's because we're already failing
2540                                 // the HTLC, i.e. its status is already set to failing.
2541                                 log_info!(logger, "Attempting to fail HTLC due to fee spike buffer violation in channel {}. Rebalancing is required.", log_bytes!(self.channel_id()));
2542                                 pending_forward_status = create_pending_htlc_status(self, pending_forward_status, 0x1000|7);
2543                         }
2544                 } else {
2545                         // Check that they won't violate our local required channel reserve by adding this HTLC.
2546                         let htlc_candidate = HTLCCandidate::new(msg.amount_msat, HTLCInitiator::RemoteOffered);
2547                         let local_commit_tx_fee_msat = self.next_local_commit_tx_fee_msat(htlc_candidate, None);
2548                         if self.value_to_self_msat < self.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000 + local_commit_tx_fee_msat {
2549                                 return Err(ChannelError::Close("Cannot accept HTLC that would put our balance under counterparty-announced channel reserve value".to_owned()));
2550                         }
2551                 }
2552                 if self.next_counterparty_htlc_id != msg.htlc_id {
2553                         return Err(ChannelError::Close(format!("Remote skipped HTLC ID (skipped ID: {})", self.next_counterparty_htlc_id)));
2554                 }
2555                 if msg.cltv_expiry >= 500000000 {
2556                         return Err(ChannelError::Close("Remote provided CLTV expiry in seconds instead of block height".to_owned()));
2557                 }
2558
2559                 if self.channel_state & ChannelState::LocalShutdownSent as u32 != 0 {
2560                         if let PendingHTLCStatus::Forward(_) = pending_forward_status {
2561                                 panic!("ChannelManager shouldn't be trying to add a forwardable HTLC after we've started closing");
2562                         }
2563                 }
2564
2565                 // Now update local state:
2566                 self.next_counterparty_htlc_id += 1;
2567                 self.pending_inbound_htlcs.push(InboundHTLCOutput {
2568                         htlc_id: msg.htlc_id,
2569                         amount_msat: msg.amount_msat,
2570                         payment_hash: msg.payment_hash,
2571                         cltv_expiry: msg.cltv_expiry,
2572                         state: InboundHTLCState::RemoteAnnounced(pending_forward_status),
2573                 });
2574                 Ok(())
2575         }
2576
2577         /// Marks an outbound HTLC which we have received update_fail/fulfill/malformed
2578         #[inline]
2579         fn mark_outbound_htlc_removed(&mut self, htlc_id: u64, check_preimage: Option<PaymentHash>, fail_reason: Option<HTLCFailReason>) -> Result<&OutboundHTLCOutput, ChannelError> {
2580                 for htlc in self.pending_outbound_htlcs.iter_mut() {
2581                         if htlc.htlc_id == htlc_id {
2582                                 match check_preimage {
2583                                         None => {},
2584                                         Some(payment_hash) =>
2585                                                 if payment_hash != htlc.payment_hash {
2586                                                         return Err(ChannelError::Close(format!("Remote tried to fulfill HTLC ({}) with an incorrect preimage", htlc_id)));
2587                                                 }
2588                                 };
2589                                 match htlc.state {
2590                                         OutboundHTLCState::LocalAnnounced(_) =>
2591                                                 return Err(ChannelError::Close(format!("Remote tried to fulfill/fail HTLC ({}) before it had been committed", htlc_id))),
2592                                         OutboundHTLCState::Committed => {
2593                                                 htlc.state = OutboundHTLCState::RemoteRemoved(fail_reason);
2594                                         },
2595                                         OutboundHTLCState::AwaitingRemoteRevokeToRemove(_) | OutboundHTLCState::AwaitingRemovedRemoteRevoke(_) | OutboundHTLCState::RemoteRemoved(_) =>
2596                                                 return Err(ChannelError::Close(format!("Remote tried to fulfill/fail HTLC ({}) that they'd already fulfilled/failed", htlc_id))),
2597                                 }
2598                                 return Ok(htlc);
2599                         }
2600                 }
2601                 Err(ChannelError::Close("Remote tried to fulfill/fail an HTLC we couldn't find".to_owned()))
2602         }
2603
2604         pub fn update_fulfill_htlc(&mut self, msg: &msgs::UpdateFulfillHTLC) -> Result<(HTLCSource, u64), ChannelError> {
2605                 if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
2606                         return Err(ChannelError::Close("Got fulfill HTLC message when channel was not in an operational state".to_owned()));
2607                 }
2608                 if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
2609                         return Err(ChannelError::Close("Peer sent update_fulfill_htlc when we needed a channel_reestablish".to_owned()));
2610                 }
2611
2612                 let payment_hash = PaymentHash(Sha256::hash(&msg.payment_preimage.0[..]).into_inner());
2613                 self.mark_outbound_htlc_removed(msg.htlc_id, Some(payment_hash), None).map(|htlc| (htlc.source.clone(), htlc.amount_msat))
2614         }
2615
2616         pub fn update_fail_htlc(&mut self, msg: &msgs::UpdateFailHTLC, fail_reason: HTLCFailReason) -> Result<(), ChannelError> {
2617                 if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
2618                         return Err(ChannelError::Close("Got fail HTLC message when channel was not in an operational state".to_owned()));
2619                 }
2620                 if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
2621                         return Err(ChannelError::Close("Peer sent update_fail_htlc when we needed a channel_reestablish".to_owned()));
2622                 }
2623
2624                 self.mark_outbound_htlc_removed(msg.htlc_id, None, Some(fail_reason))?;
2625                 Ok(())
2626         }
2627
2628         pub fn update_fail_malformed_htlc(&mut self, msg: &msgs::UpdateFailMalformedHTLC, fail_reason: HTLCFailReason) -> Result<(), ChannelError> {
2629                 if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
2630                         return Err(ChannelError::Close("Got fail malformed HTLC message when channel was not in an operational state".to_owned()));
2631                 }
2632                 if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
2633                         return Err(ChannelError::Close("Peer sent update_fail_malformed_htlc when we needed a channel_reestablish".to_owned()));
2634                 }
2635
2636                 self.mark_outbound_htlc_removed(msg.htlc_id, None, Some(fail_reason))?;
2637                 Ok(())
2638         }
2639
2640         pub fn commitment_signed<L: Deref>(&mut self, msg: &msgs::CommitmentSigned, logger: &L) -> Result<(msgs::RevokeAndACK, Option<msgs::CommitmentSigned>, ChannelMonitorUpdate), (Option<ChannelMonitorUpdate>, ChannelError)>
2641                 where L::Target: Logger
2642         {
2643                 if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
2644                         return Err((None, ChannelError::Close("Got commitment signed message when channel was not in an operational state".to_owned())));
2645                 }
2646                 if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
2647                         return Err((None, ChannelError::Close("Peer sent commitment_signed when we needed a channel_reestablish".to_owned())));
2648                 }
2649                 if self.channel_state & BOTH_SIDES_SHUTDOWN_MASK == BOTH_SIDES_SHUTDOWN_MASK && self.last_sent_closing_fee.is_some() {
2650                         return Err((None, ChannelError::Close("Peer sent commitment_signed after we'd started exchanging closing_signeds".to_owned())));
2651                 }
2652
2653                 let funding_script = self.get_funding_redeemscript();
2654
2655                 let keys = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number).map_err(|e| (None, e))?;
2656
2657                 let commitment_stats = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, false, logger);
2658                 let commitment_txid = {
2659                         let trusted_tx = commitment_stats.tx.trust();
2660                         let bitcoin_tx = trusted_tx.built_transaction();
2661                         let sighash = bitcoin_tx.get_sighash_all(&funding_script, self.channel_value_satoshis);
2662
2663                         log_trace!(logger, "Checking commitment tx signature {} by key {} against tx {} (sighash {}) with redeemscript {} in channel {}",
2664                                 log_bytes!(msg.signature.serialize_compact()[..]),
2665                                 log_bytes!(self.counterparty_funding_pubkey().serialize()), encode::serialize_hex(&bitcoin_tx.transaction),
2666                                 log_bytes!(sighash[..]), encode::serialize_hex(&funding_script), log_bytes!(self.channel_id()));
2667                         if let Err(_) = self.secp_ctx.verify(&sighash, &msg.signature, &self.counterparty_funding_pubkey()) {
2668                                 return Err((None, ChannelError::Close("Invalid commitment tx signature from peer".to_owned())));
2669                         }
2670                         bitcoin_tx.txid
2671                 };
2672                 let mut htlcs_cloned: Vec<_> = commitment_stats.htlcs_included.iter().map(|htlc| (htlc.0.clone(), htlc.1.map(|h| h.clone()))).collect();
2673
2674                 // If our counterparty updated the channel fee in this commitment transaction, check that
2675                 // they can actually afford the new fee now.
2676                 let update_fee = if let Some((_, update_state)) = self.pending_update_fee {
2677                         update_state == FeeUpdateState::RemoteAnnounced
2678                 } else { false };
2679                 if update_fee {
2680                         debug_assert!(!self.is_outbound());
2681                         let counterparty_reserve_we_require_msat = self.holder_selected_channel_reserve_satoshis * 1000;
2682                         if commitment_stats.remote_balance_msat < commitment_stats.total_fee_sat * 1000 + counterparty_reserve_we_require_msat {
2683                                 return Err((None, ChannelError::Close("Funding remote cannot afford proposed new fee".to_owned())));
2684                         }
2685                 }
2686                 #[cfg(any(test, feature = "fuzztarget"))]
2687                 {
2688                         if self.is_outbound() {
2689                                 let projected_commit_tx_info = self.next_local_commitment_tx_fee_info_cached.lock().unwrap().take();
2690                                 *self.next_remote_commitment_tx_fee_info_cached.lock().unwrap() = None;
2691                                 if let Some(info) = projected_commit_tx_info {
2692                                         let total_pending_htlcs = self.pending_inbound_htlcs.len() + self.pending_outbound_htlcs.len()
2693                                                 + self.holding_cell_htlc_updates.len();
2694                                         if info.total_pending_htlcs == total_pending_htlcs
2695                                                 && info.next_holder_htlc_id == self.next_holder_htlc_id
2696                                                 && info.next_counterparty_htlc_id == self.next_counterparty_htlc_id
2697                                                 && info.feerate == self.feerate_per_kw {
2698                                                         assert_eq!(commitment_stats.total_fee_sat, info.fee / 1000);
2699                                                 }
2700                                 }
2701                         }
2702                 }
2703
2704                 if msg.htlc_signatures.len() != commitment_stats.num_nondust_htlcs {
2705                         return Err((None, ChannelError::Close(format!("Got wrong number of HTLC signatures ({}) from remote. It must be {}", msg.htlc_signatures.len(), commitment_stats.num_nondust_htlcs))));
2706                 }
2707
2708                 // TODO: Sadly, we pass HTLCs twice to ChannelMonitor: once via the HolderCommitmentTransaction and once via the update
2709                 let mut htlcs_and_sigs = Vec::with_capacity(htlcs_cloned.len());
2710                 for (idx, (htlc, source)) in htlcs_cloned.drain(..).enumerate() {
2711                         if let Some(_) = htlc.transaction_output_index {
2712                                 let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_stats.feerate_per_kw,
2713                                         self.get_counterparty_selected_contest_delay().unwrap(), &htlc, self.opt_anchors(),
2714                                         &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
2715
2716                                 let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, self.opt_anchors(), &keys);
2717                                 let htlc_sighash = hash_to_message!(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, SigHashType::All)[..]);
2718                                 log_trace!(logger, "Checking HTLC tx signature {} by key {} against tx {} (sighash {}) with redeemscript {} in channel {}.",
2719                                         log_bytes!(msg.htlc_signatures[idx].serialize_compact()[..]), log_bytes!(keys.countersignatory_htlc_key.serialize()),
2720                                         encode::serialize_hex(&htlc_tx), log_bytes!(htlc_sighash[..]), encode::serialize_hex(&htlc_redeemscript), log_bytes!(self.channel_id()));
2721                                 if let Err(_) = self.secp_ctx.verify(&htlc_sighash, &msg.htlc_signatures[idx], &keys.countersignatory_htlc_key) {
2722                                         return Err((None, ChannelError::Close("Invalid HTLC tx signature from peer".to_owned())));
2723                                 }
2724                                 htlcs_and_sigs.push((htlc, Some(msg.htlc_signatures[idx]), source));
2725                         } else {
2726                                 htlcs_and_sigs.push((htlc, None, source));
2727                         }
2728                 }
2729
2730                 let holder_commitment_tx = HolderCommitmentTransaction::new(
2731                         commitment_stats.tx,
2732                         msg.signature,
2733                         msg.htlc_signatures.clone(),
2734                         &self.get_holder_pubkeys().funding_pubkey,
2735                         self.counterparty_funding_pubkey()
2736                 );
2737
2738                 let next_per_commitment_point = self.holder_signer.get_per_commitment_point(self.cur_holder_commitment_transaction_number - 1, &self.secp_ctx);
2739                 self.holder_signer.validate_holder_commitment(&holder_commitment_tx)
2740                         .map_err(|_| (None, ChannelError::Close("Failed to validate our commitment".to_owned())))?;
2741                 let per_commitment_secret = self.holder_signer.release_commitment_secret(self.cur_holder_commitment_transaction_number + 1);
2742
2743                 // Update state now that we've passed all the can-fail calls...
2744                 let mut need_commitment = false;
2745                 if let &mut Some((_, ref mut update_state)) = &mut self.pending_update_fee {
2746                         if *update_state == FeeUpdateState::RemoteAnnounced {
2747                                 *update_state = FeeUpdateState::AwaitingRemoteRevokeToAnnounce;
2748                                 need_commitment = true;
2749                         }
2750                 }
2751
2752                 self.latest_monitor_update_id += 1;
2753                 let mut monitor_update = ChannelMonitorUpdate {
2754                         update_id: self.latest_monitor_update_id,
2755                         updates: vec![ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo {
2756                                 commitment_tx: holder_commitment_tx,
2757                                 htlc_outputs: htlcs_and_sigs
2758                         }]
2759                 };
2760
2761                 for htlc in self.pending_inbound_htlcs.iter_mut() {
2762                         let new_forward = if let &InboundHTLCState::RemoteAnnounced(ref forward_info) = &htlc.state {
2763                                 Some(forward_info.clone())
2764                         } else { None };
2765                         if let Some(forward_info) = new_forward {
2766                                 log_trace!(logger, "Updating HTLC {} to AwaitingRemoteRevokeToAnnounce due to commitment_signed in channel {}.",
2767                                         log_bytes!(htlc.payment_hash.0), log_bytes!(self.channel_id));
2768                                 htlc.state = InboundHTLCState::AwaitingRemoteRevokeToAnnounce(forward_info);
2769                                 need_commitment = true;
2770                         }
2771                 }
2772                 for htlc in self.pending_outbound_htlcs.iter_mut() {
2773                         if let Some(fail_reason) = if let &mut OutboundHTLCState::RemoteRemoved(ref mut fail_reason) = &mut htlc.state {
2774                                 Some(fail_reason.take())
2775                         } else { None } {
2776                                 log_trace!(logger, "Updating HTLC {} to AwaitingRemoteRevokeToRemove due to commitment_signed in channel {}.",
2777                                         log_bytes!(htlc.payment_hash.0), log_bytes!(self.channel_id));
2778                                 htlc.state = OutboundHTLCState::AwaitingRemoteRevokeToRemove(fail_reason);
2779                                 need_commitment = true;
2780                         }
2781                 }
2782
2783                 self.cur_holder_commitment_transaction_number -= 1;
2784                 // Note that if we need_commitment & !AwaitingRemoteRevoke we'll call
2785                 // send_commitment_no_status_check() next which will reset this to RAAFirst.
2786                 self.resend_order = RAACommitmentOrder::CommitmentFirst;
2787
2788                 if (self.channel_state & ChannelState::MonitorUpdateFailed as u32) != 0 {
2789                         // In case we initially failed monitor updating without requiring a response, we need
2790                         // to make sure the RAA gets sent first.
2791                         self.monitor_pending_revoke_and_ack = true;
2792                         if need_commitment && (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32)) == 0 {
2793                                 // If we were going to send a commitment_signed after the RAA, go ahead and do all
2794                                 // the corresponding HTLC status updates so that get_last_commitment_update
2795                                 // includes the right HTLCs.
2796                                 self.monitor_pending_commitment_signed = true;
2797                                 let (_, mut additional_update) = self.send_commitment_no_status_check(logger).map_err(|e| (None, e))?;
2798                                 // send_commitment_no_status_check may bump latest_monitor_id but we want them to be
2799                                 // strictly increasing by one, so decrement it here.
2800                                 self.latest_monitor_update_id = monitor_update.update_id;
2801                                 monitor_update.updates.append(&mut additional_update.updates);
2802                         }
2803                         log_debug!(logger, "Received valid commitment_signed from peer in channel {}, updated HTLC state but awaiting a monitor update resolution to reply.",
2804                                 log_bytes!(self.channel_id));
2805                         return Err((Some(monitor_update), ChannelError::Ignore("Previous monitor update failure prevented generation of RAA".to_owned())));
2806                 }
2807
2808                 let commitment_signed = if need_commitment && (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32)) == 0 {
2809                         // If we're AwaitingRemoteRevoke we can't send a new commitment here, but that's ok -
2810                         // we'll send one right away when we get the revoke_and_ack when we
2811                         // free_holding_cell_htlcs().
2812                         let (msg, mut additional_update) = self.send_commitment_no_status_check(logger).map_err(|e| (None, e))?;
2813                         // send_commitment_no_status_check may bump latest_monitor_id but we want them to be
2814                         // strictly increasing by one, so decrement it here.
2815                         self.latest_monitor_update_id = monitor_update.update_id;
2816                         monitor_update.updates.append(&mut additional_update.updates);
2817                         Some(msg)
2818                 } else { None };
2819
2820                 log_debug!(logger, "Received valid commitment_signed from peer in channel {}, updating HTLC state and responding with{} a revoke_and_ack.",
2821                         log_bytes!(self.channel_id()), if commitment_signed.is_some() { " our own commitment_signed and" } else { "" });
2822
2823                 Ok((msgs::RevokeAndACK {
2824                         channel_id: self.channel_id,
2825                         per_commitment_secret,
2826                         next_per_commitment_point,
2827                 }, commitment_signed, monitor_update))
2828         }
2829
2830         /// Public version of the below, checking relevant preconditions first.
2831         /// If we're not in a state where freeing the holding cell makes sense, this is a no-op and
2832         /// returns `(None, Vec::new())`.
2833         pub fn maybe_free_holding_cell_htlcs<L: Deref>(&mut self, logger: &L) -> Result<(Option<(msgs::CommitmentUpdate, ChannelMonitorUpdate)>, Vec<(HTLCSource, PaymentHash)>), ChannelError> where L::Target: Logger {
2834                 if self.channel_state >= ChannelState::ChannelFunded as u32 &&
2835                    (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateFailed as u32)) == 0 {
2836                         self.free_holding_cell_htlcs(logger)
2837                 } else { Ok((None, Vec::new())) }
2838         }
2839
2840         /// Used to fulfill holding_cell_htlcs when we get a remote ack (or implicitly get it by them
2841         /// fulfilling or failing the last pending HTLC)
2842         fn free_holding_cell_htlcs<L: Deref>(&mut self, logger: &L) -> Result<(Option<(msgs::CommitmentUpdate, ChannelMonitorUpdate)>, Vec<(HTLCSource, PaymentHash)>), ChannelError> where L::Target: Logger {
2843                 assert_eq!(self.channel_state & ChannelState::MonitorUpdateFailed as u32, 0);
2844                 if self.holding_cell_htlc_updates.len() != 0 || self.holding_cell_update_fee.is_some() {
2845                         log_trace!(logger, "Freeing holding cell with {} HTLC updates{} in channel {}", self.holding_cell_htlc_updates.len(),
2846                                 if self.holding_cell_update_fee.is_some() { " and a fee update" } else { "" }, log_bytes!(self.channel_id()));
2847
2848                         let mut monitor_update = ChannelMonitorUpdate {
2849                                 update_id: self.latest_monitor_update_id + 1, // We don't increment this yet!
2850                                 updates: Vec::new(),
2851                         };
2852
2853                         let mut htlc_updates = Vec::new();
2854                         mem::swap(&mut htlc_updates, &mut self.holding_cell_htlc_updates);
2855                         let mut update_add_htlcs = Vec::with_capacity(htlc_updates.len());
2856                         let mut update_fulfill_htlcs = Vec::with_capacity(htlc_updates.len());
2857                         let mut update_fail_htlcs = Vec::with_capacity(htlc_updates.len());
2858                         let mut htlcs_to_fail = Vec::new();
2859                         for htlc_update in htlc_updates.drain(..) {
2860                                 // Note that this *can* fail, though it should be due to rather-rare conditions on
2861                                 // fee races with adding too many outputs which push our total payments just over
2862                                 // the limit. In case it's less rare than I anticipate, we may want to revisit
2863                                 // handling this case better and maybe fulfilling some of the HTLCs while attempting
2864                                 // to rebalance channels.
2865                                 match &htlc_update {
2866                                         &HTLCUpdateAwaitingACK::AddHTLC {amount_msat, cltv_expiry, ref payment_hash, ref source, ref onion_routing_packet, ..} => {
2867                                                 match self.send_htlc(amount_msat, *payment_hash, cltv_expiry, source.clone(), onion_routing_packet.clone(), logger) {
2868                                                         Ok(update_add_msg_option) => update_add_htlcs.push(update_add_msg_option.unwrap()),
2869                                                         Err(e) => {
2870                                                                 match e {
2871                                                                         ChannelError::Ignore(ref msg) => {
2872                                                                                 log_info!(logger, "Failed to send HTLC with payment_hash {} due to {} in channel {}",
2873                                                                                         log_bytes!(payment_hash.0), msg, log_bytes!(self.channel_id()));
2874                                                                                 // If we fail to send here, then this HTLC should
2875                                                                                 // be failed backwards. Failing to send here
2876                                                                                 // indicates that this HTLC may keep being put back
2877                                                                                 // into the holding cell without ever being
2878                                                                                 // successfully forwarded/failed/fulfilled, causing
2879                                                                                 // our counterparty to eventually close on us.
2880                                                                                 htlcs_to_fail.push((source.clone(), *payment_hash));
2881                                                                         },
2882                                                                         _ => {
2883                                                                                 panic!("Got a non-IgnoreError action trying to send holding cell HTLC");
2884                                                                         },
2885                                                                 }
2886                                                         }
2887                                                 }
2888                                         },
2889                                         &HTLCUpdateAwaitingACK::ClaimHTLC { ref payment_preimage, htlc_id, .. } => {
2890                                                 // If an HTLC claim was previously added to the holding cell (via
2891                                                 // `get_update_fulfill_htlc`, then generating the claim message itself must
2892                                                 // not fail - any in between attempts to claim the HTLC will have resulted
2893                                                 // in it hitting the holding cell again and we cannot change the state of a
2894                                                 // holding cell HTLC from fulfill to anything else.
2895                                                 let (update_fulfill_msg_option, mut additional_monitor_update) =
2896                                                         if let UpdateFulfillFetch::NewClaim { msg, monitor_update, .. } = self.get_update_fulfill_htlc(htlc_id, *payment_preimage, logger) {
2897                                                                 (msg, monitor_update)
2898                                                         } else { unreachable!() };
2899                                                 update_fulfill_htlcs.push(update_fulfill_msg_option.unwrap());
2900                                                 monitor_update.updates.append(&mut additional_monitor_update.updates);
2901                                         },
2902                                         &HTLCUpdateAwaitingACK::FailHTLC { htlc_id, ref err_packet } => {
2903                                                 match self.get_update_fail_htlc(htlc_id, err_packet.clone(), logger) {
2904                                                         Ok(update_fail_msg_option) => {
2905                                                                 // If an HTLC failure was previously added to the holding cell (via
2906                                                                 // `get_update_fail_htlc`) then generating the fail message itself
2907                                                                 // must not fail - we should never end up in a state where we
2908                                                                 // double-fail an HTLC or fail-then-claim an HTLC as it indicates
2909                                                                 // we didn't wait for a full revocation before failing.
2910                                                                 update_fail_htlcs.push(update_fail_msg_option.unwrap())
2911                                                         },
2912                                                         Err(e) => {
2913                                                                 if let ChannelError::Ignore(_) = e {}
2914                                                                 else {
2915                                                                         panic!("Got a non-IgnoreError action trying to fail holding cell HTLC");
2916                                                                 }
2917                                                         }
2918                                                 }
2919                                         },
2920                                 }
2921                         }
2922                         if update_add_htlcs.is_empty() && update_fulfill_htlcs.is_empty() && update_fail_htlcs.is_empty() && self.holding_cell_update_fee.is_none() {
2923                                 return Ok((None, htlcs_to_fail));
2924                         }
2925                         let update_fee = if let Some(feerate) = self.holding_cell_update_fee.take() {
2926                                 self.send_update_fee(feerate, logger)
2927                         } else {
2928                                 None
2929                         };
2930
2931                         let (commitment_signed, mut additional_update) = self.send_commitment_no_status_check(logger)?;
2932                         // send_commitment_no_status_check and get_update_fulfill_htlc may bump latest_monitor_id
2933                         // but we want them to be strictly increasing by one, so reset it here.
2934                         self.latest_monitor_update_id = monitor_update.update_id;
2935                         monitor_update.updates.append(&mut additional_update.updates);
2936
2937                         log_debug!(logger, "Freeing holding cell in channel {} resulted in {}{} HTLCs added, {} HTLCs fulfilled, and {} HTLCs failed.",
2938                                 log_bytes!(self.channel_id()), if update_fee.is_some() { "a fee update, " } else { "" },
2939                                 update_add_htlcs.len(), update_fulfill_htlcs.len(), update_fail_htlcs.len());
2940
2941                         Ok((Some((msgs::CommitmentUpdate {
2942                                 update_add_htlcs,
2943                                 update_fulfill_htlcs,
2944                                 update_fail_htlcs,
2945                                 update_fail_malformed_htlcs: Vec::new(),
2946                                 update_fee,
2947                                 commitment_signed,
2948                         }, monitor_update)), htlcs_to_fail))
2949                 } else {
2950                         Ok((None, Vec::new()))
2951                 }
2952         }
2953
2954         /// Handles receiving a remote's revoke_and_ack. Note that we may return a new
2955         /// commitment_signed message here in case we had pending outbound HTLCs to add which were
2956         /// waiting on this revoke_and_ack. The generation of this new commitment_signed may also fail,
2957         /// generating an appropriate error *after* the channel state has been updated based on the
2958         /// revoke_and_ack message.
2959         pub fn revoke_and_ack<L: Deref>(&mut self, msg: &msgs::RevokeAndACK, logger: &L) -> Result<RAAUpdates, ChannelError>
2960                 where L::Target: Logger,
2961         {
2962                 if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
2963                         return Err(ChannelError::Close("Got revoke/ACK message when channel was not in an operational state".to_owned()));
2964                 }
2965                 if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
2966                         return Err(ChannelError::Close("Peer sent revoke_and_ack when we needed a channel_reestablish".to_owned()));
2967                 }
2968                 if self.channel_state & BOTH_SIDES_SHUTDOWN_MASK == BOTH_SIDES_SHUTDOWN_MASK && self.last_sent_closing_fee.is_some() {
2969                         return Err(ChannelError::Close("Peer sent revoke_and_ack after we'd started exchanging closing_signeds".to_owned()));
2970                 }
2971
2972                 let secret = secp_check!(SecretKey::from_slice(&msg.per_commitment_secret), "Peer provided an invalid per_commitment_secret".to_owned());
2973
2974                 if let Some(counterparty_prev_commitment_point) = self.counterparty_prev_commitment_point {
2975                         if PublicKey::from_secret_key(&self.secp_ctx, &secret) != counterparty_prev_commitment_point {
2976                                 return Err(ChannelError::Close("Got a revoke commitment secret which didn't correspond to their current pubkey".to_owned()));
2977                         }
2978                 }
2979
2980                 if self.channel_state & ChannelState::AwaitingRemoteRevoke as u32 == 0 {
2981                         // Our counterparty seems to have burned their coins to us (by revoking a state when we
2982                         // haven't given them a new commitment transaction to broadcast). We should probably
2983                         // take advantage of this by updating our channel monitor, sending them an error, and
2984                         // waiting for them to broadcast their latest (now-revoked claim). But, that would be a
2985                         // lot of work, and there's some chance this is all a misunderstanding anyway.
2986                         // We have to do *something*, though, since our signer may get mad at us for otherwise
2987                         // jumping a remote commitment number, so best to just force-close and move on.
2988                         return Err(ChannelError::Close("Received an unexpected revoke_and_ack".to_owned()));
2989                 }
2990
2991                 #[cfg(any(test, feature = "fuzztarget"))]
2992                 {
2993                         *self.next_local_commitment_tx_fee_info_cached.lock().unwrap() = None;
2994                         *self.next_remote_commitment_tx_fee_info_cached.lock().unwrap() = None;
2995                 }
2996
2997                 self.holder_signer.validate_counterparty_revocation(
2998                         self.cur_counterparty_commitment_transaction_number + 1,
2999                         &secret
3000                 ).map_err(|_| ChannelError::Close("Failed to validate revocation from peer".to_owned()))?;
3001
3002                 self.commitment_secrets.provide_secret(self.cur_counterparty_commitment_transaction_number + 1, msg.per_commitment_secret)
3003                         .map_err(|_| ChannelError::Close("Previous secrets did not match new one".to_owned()))?;
3004                 self.latest_monitor_update_id += 1;
3005                 let mut monitor_update = ChannelMonitorUpdate {
3006                         update_id: self.latest_monitor_update_id,
3007                         updates: vec![ChannelMonitorUpdateStep::CommitmentSecret {
3008                                 idx: self.cur_counterparty_commitment_transaction_number + 1,
3009                                 secret: msg.per_commitment_secret,
3010                         }],
3011                 };
3012
3013                 // Update state now that we've passed all the can-fail calls...
3014                 // (note that we may still fail to generate the new commitment_signed message, but that's
3015                 // OK, we step the channel here and *then* if the new generation fails we can fail the
3016                 // channel based on that, but stepping stuff here should be safe either way.
3017                 self.channel_state &= !(ChannelState::AwaitingRemoteRevoke as u32);
3018                 self.counterparty_prev_commitment_point = self.counterparty_cur_commitment_point;
3019                 self.counterparty_cur_commitment_point = Some(msg.next_per_commitment_point);
3020                 self.cur_counterparty_commitment_transaction_number -= 1;
3021
3022                 if self.announcement_sigs_state == AnnouncementSigsState::Committed {
3023                         self.announcement_sigs_state = AnnouncementSigsState::PeerReceived;
3024                 }
3025
3026                 log_trace!(logger, "Updating HTLCs on receipt of RAA in channel {}...", log_bytes!(self.channel_id()));
3027                 let mut to_forward_infos = Vec::new();
3028                 let mut revoked_htlcs = Vec::new();
3029                 let mut finalized_claimed_htlcs = Vec::new();
3030                 let mut update_fail_htlcs = Vec::new();
3031                 let mut update_fail_malformed_htlcs = Vec::new();
3032                 let mut require_commitment = false;
3033                 let mut value_to_self_msat_diff: i64 = 0;
3034
3035                 {
3036                         // Take references explicitly so that we can hold multiple references to self.
3037                         let pending_inbound_htlcs: &mut Vec<_> = &mut self.pending_inbound_htlcs;
3038                         let pending_outbound_htlcs: &mut Vec<_> = &mut self.pending_outbound_htlcs;
3039
3040                         // We really shouldnt have two passes here, but retain gives a non-mutable ref (Rust bug)
3041                         pending_inbound_htlcs.retain(|htlc| {
3042                                 if let &InboundHTLCState::LocalRemoved(ref reason) = &htlc.state {
3043                                         log_trace!(logger, " ...removing inbound LocalRemoved {}", log_bytes!(htlc.payment_hash.0));
3044                                         if let &InboundHTLCRemovalReason::Fulfill(_) = reason {
3045                                                 value_to_self_msat_diff += htlc.amount_msat as i64;
3046                                         }
3047                                         false
3048                                 } else { true }
3049                         });
3050                         pending_outbound_htlcs.retain(|htlc| {
3051                                 if let &OutboundHTLCState::AwaitingRemovedRemoteRevoke(ref fail_reason) = &htlc.state {
3052                                         log_trace!(logger, " ...removing outbound AwaitingRemovedRemoteRevoke {}", log_bytes!(htlc.payment_hash.0));
3053                                         if let Some(reason) = fail_reason.clone() { // We really want take() here, but, again, non-mut ref :(
3054                                                 revoked_htlcs.push((htlc.source.clone(), htlc.payment_hash, reason));
3055                                         } else {
3056                                                 finalized_claimed_htlcs.push(htlc.source.clone());
3057                                                 // They fulfilled, so we sent them money
3058                                                 value_to_self_msat_diff -= htlc.amount_msat as i64;
3059                                         }
3060                                         false
3061                                 } else { true }
3062                         });
3063                         for htlc in pending_inbound_htlcs.iter_mut() {
3064                                 let swap = if let &InboundHTLCState::AwaitingRemoteRevokeToAnnounce(_) = &htlc.state {
3065                                         true
3066                                 } else if let &InboundHTLCState::AwaitingAnnouncedRemoteRevoke(_) = &htlc.state {
3067                                         true
3068                                 } else { false };
3069                                 if swap {
3070                                         let mut state = InboundHTLCState::Committed;
3071                                         mem::swap(&mut state, &mut htlc.state);
3072
3073                                         if let InboundHTLCState::AwaitingRemoteRevokeToAnnounce(forward_info) = state {
3074                                                 log_trace!(logger, " ...promoting inbound AwaitingRemoteRevokeToAnnounce {} to AwaitingAnnouncedRemoteRevoke", log_bytes!(htlc.payment_hash.0));
3075                                                 htlc.state = InboundHTLCState::AwaitingAnnouncedRemoteRevoke(forward_info);
3076                                                 require_commitment = true;
3077                                         } else if let InboundHTLCState::AwaitingAnnouncedRemoteRevoke(forward_info) = state {
3078                                                 match forward_info {
3079                                                         PendingHTLCStatus::Fail(fail_msg) => {
3080                                                                 log_trace!(logger, " ...promoting inbound AwaitingAnnouncedRemoteRevoke {} to LocalRemoved due to PendingHTLCStatus indicating failure", log_bytes!(htlc.payment_hash.0));
3081                                                                 require_commitment = true;
3082                                                                 match fail_msg {
3083                                                                         HTLCFailureMsg::Relay(msg) => {
3084                                                                                 htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::FailRelay(msg.reason.clone()));
3085                                                                                 update_fail_htlcs.push(msg)
3086                                                                         },
3087                                                                         HTLCFailureMsg::Malformed(msg) => {
3088                                                                                 htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::FailMalformed((msg.sha256_of_onion, msg.failure_code)));
3089                                                                                 update_fail_malformed_htlcs.push(msg)
3090                                                                         },
3091                                                                 }
3092                                                         },
3093                                                         PendingHTLCStatus::Forward(forward_info) => {
3094                                                                 log_trace!(logger, " ...promoting inbound AwaitingAnnouncedRemoteRevoke {} to Committed", log_bytes!(htlc.payment_hash.0));
3095                                                                 to_forward_infos.push((forward_info, htlc.htlc_id));
3096                                                                 htlc.state = InboundHTLCState::Committed;
3097                                                         }
3098                                                 }
3099                                         }
3100                                 }
3101                         }
3102                         for htlc in pending_outbound_htlcs.iter_mut() {
3103                                 if let OutboundHTLCState::LocalAnnounced(_) = htlc.state {
3104                                         log_trace!(logger, " ...promoting outbound LocalAnnounced {} to Committed", log_bytes!(htlc.payment_hash.0));
3105                                         htlc.state = OutboundHTLCState::Committed;
3106                                 }
3107                                 if let Some(fail_reason) = if let &mut OutboundHTLCState::AwaitingRemoteRevokeToRemove(ref mut fail_reason) = &mut htlc.state {
3108                                         Some(fail_reason.take())
3109                                 } else { None } {
3110                                         log_trace!(logger, " ...promoting outbound AwaitingRemoteRevokeToRemove {} to AwaitingRemovedRemoteRevoke", log_bytes!(htlc.payment_hash.0));
3111                                         htlc.state = OutboundHTLCState::AwaitingRemovedRemoteRevoke(fail_reason);
3112                                         require_commitment = true;
3113                                 }
3114                         }
3115                 }
3116                 self.value_to_self_msat = (self.value_to_self_msat as i64 + value_to_self_msat_diff) as u64;
3117
3118                 if let Some((feerate, update_state)) = self.pending_update_fee {
3119                         match update_state {
3120                                 FeeUpdateState::Outbound => {
3121                                         debug_assert!(self.is_outbound());
3122                                         log_trace!(logger, " ...promoting outbound fee update {} to Committed", feerate);
3123                                         self.feerate_per_kw = feerate;
3124                                         self.pending_update_fee = None;
3125                                 },
3126                                 FeeUpdateState::RemoteAnnounced => { debug_assert!(!self.is_outbound()); },
3127                                 FeeUpdateState::AwaitingRemoteRevokeToAnnounce => {
3128                                         debug_assert!(!self.is_outbound());
3129                                         log_trace!(logger, " ...promoting inbound AwaitingRemoteRevokeToAnnounce fee update {} to Committed", feerate);
3130                                         require_commitment = true;
3131                                         self.feerate_per_kw = feerate;
3132                                         self.pending_update_fee = None;
3133                                 },
3134                         }
3135                 }
3136
3137                 if (self.channel_state & ChannelState::MonitorUpdateFailed as u32) == ChannelState::MonitorUpdateFailed as u32 {
3138                         // We can't actually generate a new commitment transaction (incl by freeing holding
3139                         // cells) while we can't update the monitor, so we just return what we have.
3140                         if require_commitment {
3141                                 self.monitor_pending_commitment_signed = true;
3142                                 // When the monitor updating is restored we'll call get_last_commitment_update(),
3143                                 // which does not update state, but we're definitely now awaiting a remote revoke
3144                                 // before we can step forward any more, so set it here.
3145                                 let (_, mut additional_update) = self.send_commitment_no_status_check(logger)?;
3146                                 // send_commitment_no_status_check may bump latest_monitor_id but we want them to be
3147                                 // strictly increasing by one, so decrement it here.
3148                                 self.latest_monitor_update_id = monitor_update.update_id;
3149                                 monitor_update.updates.append(&mut additional_update.updates);
3150                         }
3151                         self.monitor_pending_forwards.append(&mut to_forward_infos);
3152                         self.monitor_pending_failures.append(&mut revoked_htlcs);
3153                         self.monitor_pending_finalized_fulfills.append(&mut finalized_claimed_htlcs);
3154                         log_debug!(logger, "Received a valid revoke_and_ack for channel {} but awaiting a monitor update resolution to reply.", log_bytes!(self.channel_id()));
3155                         return Ok(RAAUpdates {
3156                                 commitment_update: None, finalized_claimed_htlcs: Vec::new(),
3157                                 accepted_htlcs: Vec::new(), failed_htlcs: Vec::new(),
3158                                 monitor_update,
3159                                 holding_cell_failed_htlcs: Vec::new()
3160                         });
3161                 }
3162
3163                 match self.free_holding_cell_htlcs(logger)? {
3164                         (Some((mut commitment_update, mut additional_update)), htlcs_to_fail) => {
3165                                 commitment_update.update_fail_htlcs.reserve(update_fail_htlcs.len());
3166                                 for fail_msg in update_fail_htlcs.drain(..) {
3167                                         commitment_update.update_fail_htlcs.push(fail_msg);
3168                                 }
3169                                 commitment_update.update_fail_malformed_htlcs.reserve(update_fail_malformed_htlcs.len());
3170                                 for fail_msg in update_fail_malformed_htlcs.drain(..) {
3171                                         commitment_update.update_fail_malformed_htlcs.push(fail_msg);
3172                                 }
3173
3174                                 // free_holding_cell_htlcs may bump latest_monitor_id multiple times but we want them to be
3175                                 // strictly increasing by one, so decrement it here.
3176                                 self.latest_monitor_update_id = monitor_update.update_id;
3177                                 monitor_update.updates.append(&mut additional_update.updates);
3178
3179                                 Ok(RAAUpdates {
3180                                         commitment_update: Some(commitment_update),
3181                                         finalized_claimed_htlcs,
3182                                         accepted_htlcs: to_forward_infos,
3183                                         failed_htlcs: revoked_htlcs,
3184                                         monitor_update,
3185                                         holding_cell_failed_htlcs: htlcs_to_fail
3186                                 })
3187                         },
3188                         (None, htlcs_to_fail) => {
3189                                 if require_commitment {
3190                                         let (commitment_signed, mut additional_update) = self.send_commitment_no_status_check(logger)?;
3191
3192                                         // send_commitment_no_status_check may bump latest_monitor_id but we want them to be
3193                                         // strictly increasing by one, so decrement it here.
3194                                         self.latest_monitor_update_id = monitor_update.update_id;
3195                                         monitor_update.updates.append(&mut additional_update.updates);
3196
3197                                         log_debug!(logger, "Received a valid revoke_and_ack for channel {}. Responding with a commitment update with {} HTLCs failed.",
3198                                                 log_bytes!(self.channel_id()), update_fail_htlcs.len() + update_fail_malformed_htlcs.len());
3199                                         Ok(RAAUpdates {
3200                                                 commitment_update: Some(msgs::CommitmentUpdate {
3201                                                         update_add_htlcs: Vec::new(),
3202                                                         update_fulfill_htlcs: Vec::new(),
3203                                                         update_fail_htlcs,
3204                                                         update_fail_malformed_htlcs,
3205                                                         update_fee: None,
3206                                                         commitment_signed
3207                                                 }),
3208                                                 finalized_claimed_htlcs,
3209                                                 accepted_htlcs: to_forward_infos, failed_htlcs: revoked_htlcs,
3210                                                 monitor_update, holding_cell_failed_htlcs: htlcs_to_fail
3211                                         })
3212                                 } else {
3213                                         log_debug!(logger, "Received a valid revoke_and_ack for channel {} with no reply necessary.", log_bytes!(self.channel_id()));
3214                                         Ok(RAAUpdates {
3215                                                 commitment_update: None,
3216                                                 finalized_claimed_htlcs,
3217                                                 accepted_htlcs: to_forward_infos, failed_htlcs: revoked_htlcs,
3218                                                 monitor_update, holding_cell_failed_htlcs: htlcs_to_fail
3219                                         })
3220                                 }
3221                         }
3222                 }
3223         }
3224
3225         /// Adds a pending update to this channel. See the doc for send_htlc for
3226         /// further details on the optionness of the return value.
3227         /// If our balance is too low to cover the cost of the next commitment transaction at the
3228         /// new feerate, the update is cancelled.
3229         /// You MUST call send_commitment prior to any other calls on this Channel
3230         fn send_update_fee<L: Deref>(&mut self, feerate_per_kw: u32, logger: &L) -> Option<msgs::UpdateFee> where L::Target: Logger {
3231                 if !self.is_outbound() {
3232                         panic!("Cannot send fee from inbound channel");
3233                 }
3234                 if !self.is_usable() {
3235                         panic!("Cannot update fee until channel is fully established and we haven't started shutting down");
3236                 }
3237                 if !self.is_live() {
3238                         panic!("Cannot update fee while peer is disconnected/we're awaiting a monitor update (ChannelManager should have caught this)");
3239                 }
3240
3241                 // Before proposing a feerate update, check that we can actually afford the new fee.
3242                 let inbound_stats = self.get_inbound_pending_htlc_stats(Some(feerate_per_kw));
3243                 let outbound_stats = self.get_outbound_pending_htlc_stats(Some(feerate_per_kw));
3244                 let keys = if let Ok(keys) = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number) { keys } else { return None; };
3245                 let commitment_stats = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, true, logger);
3246                 let buffer_fee_msat = Channel::<Signer>::commit_tx_fee_sat(feerate_per_kw, commitment_stats.num_nondust_htlcs + outbound_stats.on_holder_tx_holding_cell_htlcs_count as usize + CONCURRENT_INBOUND_HTLC_FEE_BUFFER as usize) * 1000;
3247                 let holder_balance_msat = commitment_stats.local_balance_msat - outbound_stats.holding_cell_msat;
3248                 if holder_balance_msat < buffer_fee_msat  + self.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000 {
3249                         //TODO: auto-close after a number of failures?
3250                         log_debug!(logger, "Cannot afford to send new feerate at {}", feerate_per_kw);
3251                         return None;
3252                 }
3253
3254                 // Note, we evaluate pending htlc "preemptive" trimmed-to-dust threshold at the proposed `feerate_per_kw`.
3255                 let holder_tx_dust_exposure = inbound_stats.on_holder_tx_dust_exposure_msat + outbound_stats.on_holder_tx_dust_exposure_msat;
3256                 let counterparty_tx_dust_exposure = inbound_stats.on_counterparty_tx_dust_exposure_msat + outbound_stats.on_counterparty_tx_dust_exposure_msat;
3257                 if holder_tx_dust_exposure > self.get_max_dust_htlc_exposure_msat() {
3258                         log_debug!(logger, "Cannot afford to send new feerate at {} without infringing max dust htlc exposure", feerate_per_kw);
3259                         return None;
3260                 }
3261                 if counterparty_tx_dust_exposure > self.get_max_dust_htlc_exposure_msat() {
3262                         log_debug!(logger, "Cannot afford to send new feerate at {} without infringing max dust htlc exposure", feerate_per_kw);
3263                         return None;
3264                 }
3265
3266                 if (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::MonitorUpdateFailed as u32)) != 0 {
3267                         self.holding_cell_update_fee = Some(feerate_per_kw);
3268                         return None;
3269                 }
3270
3271                 debug_assert!(self.pending_update_fee.is_none());
3272                 self.pending_update_fee = Some((feerate_per_kw, FeeUpdateState::Outbound));
3273
3274                 Some(msgs::UpdateFee {
3275                         channel_id: self.channel_id,
3276                         feerate_per_kw,
3277                 })
3278         }
3279
3280         pub fn send_update_fee_and_commit<L: Deref>(&mut self, feerate_per_kw: u32, logger: &L) -> Result<Option<(msgs::UpdateFee, msgs::CommitmentSigned, ChannelMonitorUpdate)>, ChannelError> where L::Target: Logger {
3281                 match self.send_update_fee(feerate_per_kw, logger) {
3282                         Some(update_fee) => {
3283                                 let (commitment_signed, monitor_update) = self.send_commitment_no_status_check(logger)?;
3284                                 Ok(Some((update_fee, commitment_signed, monitor_update)))
3285                         },
3286                         None => Ok(None)
3287                 }
3288         }
3289
3290         /// Removes any uncommitted inbound HTLCs and resets the state of uncommitted outbound HTLC
3291         /// updates, to be used on peer disconnection. After this, update_*_htlc messages need to be
3292         /// resent.
3293         /// No further message handling calls may be made until a channel_reestablish dance has
3294         /// completed.
3295         pub fn remove_uncommitted_htlcs_and_mark_paused<L: Deref>(&mut self, logger: &L)  where L::Target: Logger {
3296                 assert_eq!(self.channel_state & ChannelState::ShutdownComplete as u32, 0);
3297                 if self.channel_state < ChannelState::FundingSent as u32 {
3298                         self.channel_state = ChannelState::ShutdownComplete as u32;
3299                         return;
3300                 }
3301
3302                 if self.announcement_sigs_state == AnnouncementSigsState::MessageSent || self.announcement_sigs_state == AnnouncementSigsState::Committed {
3303                         self.announcement_sigs_state = AnnouncementSigsState::NotSent;
3304                 }
3305
3306                 // Upon reconnect we have to start the closing_signed dance over, but shutdown messages
3307                 // will be retransmitted.
3308                 self.last_sent_closing_fee = None;
3309                 self.pending_counterparty_closing_signed = None;
3310                 self.closing_fee_limits = None;
3311
3312                 let mut inbound_drop_count = 0;
3313                 self.pending_inbound_htlcs.retain(|htlc| {
3314                         match htlc.state {
3315                                 InboundHTLCState::RemoteAnnounced(_) => {
3316                                         // They sent us an update_add_htlc but we never got the commitment_signed.
3317                                         // We'll tell them what commitment_signed we're expecting next and they'll drop
3318                                         // this HTLC accordingly
3319                                         inbound_drop_count += 1;
3320                                         false
3321                                 },
3322                                 InboundHTLCState::AwaitingRemoteRevokeToAnnounce(_)|InboundHTLCState::AwaitingAnnouncedRemoteRevoke(_) => {
3323                                         // We received a commitment_signed updating this HTLC and (at least hopefully)
3324                                         // sent a revoke_and_ack (which we can re-transmit) and have heard nothing
3325                                         // in response to it yet, so don't touch it.
3326                                         true
3327                                 },
3328                                 InboundHTLCState::Committed => true,
3329                                 InboundHTLCState::LocalRemoved(_) => {
3330                                         // We (hopefully) sent a commitment_signed updating this HTLC (which we can
3331                                         // re-transmit if needed) and they may have even sent a revoke_and_ack back
3332                                         // (that we missed). Keep this around for now and if they tell us they missed
3333                                         // the commitment_signed we can re-transmit the update then.
3334                                         true
3335                                 },
3336                         }
3337                 });
3338                 self.next_counterparty_htlc_id -= inbound_drop_count;
3339
3340                 if let Some((_, update_state)) = self.pending_update_fee {
3341                         if update_state == FeeUpdateState::RemoteAnnounced {
3342                                 debug_assert!(!self.is_outbound());
3343                                 self.pending_update_fee = None;
3344                         }
3345                 }
3346
3347                 for htlc in self.pending_outbound_htlcs.iter_mut() {
3348                         if let OutboundHTLCState::RemoteRemoved(_) = htlc.state {
3349                                 // They sent us an update to remove this but haven't yet sent the corresponding
3350                                 // commitment_signed, we need to move it back to Committed and they can re-send
3351                                 // the update upon reconnection.
3352                                 htlc.state = OutboundHTLCState::Committed;
3353                         }
3354                 }
3355
3356                 self.channel_state |= ChannelState::PeerDisconnected as u32;
3357                 log_trace!(logger, "Peer disconnection resulted in {} remote-announced HTLC drops on channel {}", inbound_drop_count, log_bytes!(self.channel_id()));
3358         }
3359
3360         /// Indicates that a ChannelMonitor update failed to be stored by the client and further
3361         /// updates are partially paused.
3362         /// This must be called immediately after the call which generated the ChannelMonitor update
3363         /// which failed. The messages which were generated from that call which generated the
3364         /// monitor update failure must *not* have been sent to the remote end, and must instead
3365         /// have been dropped. They will be regenerated when monitor_updating_restored is called.
3366         pub fn monitor_update_failed(&mut self, resend_raa: bool, resend_commitment: bool,
3367                 mut pending_forwards: Vec<(PendingHTLCInfo, u64)>,
3368                 mut pending_fails: Vec<(HTLCSource, PaymentHash, HTLCFailReason)>,
3369                 mut pending_finalized_claimed_htlcs: Vec<HTLCSource>
3370         ) {
3371                 self.monitor_pending_revoke_and_ack |= resend_raa;
3372                 self.monitor_pending_commitment_signed |= resend_commitment;
3373                 self.monitor_pending_forwards.append(&mut pending_forwards);
3374                 self.monitor_pending_failures.append(&mut pending_fails);
3375                 self.monitor_pending_finalized_fulfills.append(&mut pending_finalized_claimed_htlcs);
3376                 self.channel_state |= ChannelState::MonitorUpdateFailed as u32;
3377         }
3378
3379         /// Indicates that the latest ChannelMonitor update has been committed by the client
3380         /// successfully and we should restore normal operation. Returns messages which should be sent
3381         /// to the remote side.
3382         pub fn monitor_updating_restored<L: Deref>(&mut self, logger: &L, node_pk: PublicKey, genesis_block_hash: BlockHash, best_block_height: u32) -> MonitorRestoreUpdates where L::Target: Logger {
3383                 assert_eq!(self.channel_state & ChannelState::MonitorUpdateFailed as u32, ChannelState::MonitorUpdateFailed as u32);
3384                 self.channel_state &= !(ChannelState::MonitorUpdateFailed as u32);
3385
3386                 let funding_broadcastable = if self.channel_state & (ChannelState::FundingSent as u32) != 0 && self.is_outbound() {
3387                         self.funding_transaction.take()
3388                 } else { None };
3389
3390                 // We will never broadcast the funding transaction when we're in MonitorUpdateFailed (and
3391                 // we assume the user never directly broadcasts the funding transaction and waits for us to
3392                 // do it). Thus, we can only ever hit monitor_pending_funding_locked when we're an inbound
3393                 // channel which failed to persist the monitor on funding_created, and we got the funding
3394                 // transaction confirmed before the monitor was persisted.
3395                 let funding_locked = if self.monitor_pending_funding_locked {
3396                         assert!(!self.is_outbound(), "Funding transaction broadcast by the local client before it should have - LDK didn't do it!");
3397                         self.monitor_pending_funding_locked = false;
3398                         let next_per_commitment_point = self.holder_signer.get_per_commitment_point(self.cur_holder_commitment_transaction_number, &self.secp_ctx);
3399                         Some(msgs::FundingLocked {
3400                                 channel_id: self.channel_id(),
3401                                 next_per_commitment_point,
3402                                 short_channel_id_alias: None,
3403                         })
3404                 } else { None };
3405
3406                 let announcement_sigs = self.get_announcement_sigs(node_pk, genesis_block_hash, best_block_height, logger);
3407
3408                 let mut accepted_htlcs = Vec::new();
3409                 mem::swap(&mut accepted_htlcs, &mut self.monitor_pending_forwards);
3410                 let mut failed_htlcs = Vec::new();
3411                 mem::swap(&mut failed_htlcs, &mut self.monitor_pending_failures);
3412                 let mut finalized_claimed_htlcs = Vec::new();
3413                 mem::swap(&mut finalized_claimed_htlcs, &mut self.monitor_pending_finalized_fulfills);
3414
3415                 if self.channel_state & (ChannelState::PeerDisconnected as u32) != 0 {
3416                         self.monitor_pending_revoke_and_ack = false;
3417                         self.monitor_pending_commitment_signed = false;
3418                         return MonitorRestoreUpdates {
3419                                 raa: None, commitment_update: None, order: RAACommitmentOrder::RevokeAndACKFirst,
3420                                 accepted_htlcs, failed_htlcs, finalized_claimed_htlcs, funding_broadcastable, funding_locked, announcement_sigs
3421                         };
3422                 }
3423
3424                 let raa = if self.monitor_pending_revoke_and_ack {
3425                         Some(self.get_last_revoke_and_ack())
3426                 } else { None };
3427                 let commitment_update = if self.monitor_pending_commitment_signed {
3428                         Some(self.get_last_commitment_update(logger))
3429                 } else { None };
3430
3431                 self.monitor_pending_revoke_and_ack = false;
3432                 self.monitor_pending_commitment_signed = false;
3433                 let order = self.resend_order.clone();
3434                 log_debug!(logger, "Restored monitor updating in channel {} resulting in {}{} commitment update and {} RAA, with {} first",
3435                         log_bytes!(self.channel_id()), if funding_broadcastable.is_some() { "a funding broadcastable, " } else { "" },
3436                         if commitment_update.is_some() { "a" } else { "no" }, if raa.is_some() { "an" } else { "no" },
3437                         match order { RAACommitmentOrder::CommitmentFirst => "commitment", RAACommitmentOrder::RevokeAndACKFirst => "RAA"});
3438                 MonitorRestoreUpdates {
3439                         raa, commitment_update, order, accepted_htlcs, failed_htlcs, finalized_claimed_htlcs, funding_broadcastable, funding_locked, announcement_sigs
3440                 }
3441         }
3442
3443         pub fn update_fee<F: Deref>(&mut self, fee_estimator: &F, msg: &msgs::UpdateFee) -> Result<(), ChannelError>
3444                 where F::Target: FeeEstimator
3445         {
3446                 if self.is_outbound() {
3447                         return Err(ChannelError::Close("Non-funding remote tried to update channel fee".to_owned()));
3448                 }
3449                 if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
3450                         return Err(ChannelError::Close("Peer sent update_fee when we needed a channel_reestablish".to_owned()));
3451                 }
3452                 Channel::<Signer>::check_remote_fee(fee_estimator, msg.feerate_per_kw)?;
3453                 let feerate_over_dust_buffer = msg.feerate_per_kw > self.get_dust_buffer_feerate(None);
3454
3455                 self.pending_update_fee = Some((msg.feerate_per_kw, FeeUpdateState::RemoteAnnounced));
3456                 self.update_time_counter += 1;
3457                 // If the feerate has increased over the previous dust buffer (note that
3458                 // `get_dust_buffer_feerate` considers the `pending_update_fee` status), check that we
3459                 // won't be pushed over our dust exposure limit by the feerate increase.
3460                 if feerate_over_dust_buffer {
3461                         let inbound_stats = self.get_inbound_pending_htlc_stats(None);
3462                         let outbound_stats = self.get_outbound_pending_htlc_stats(None);
3463                         let holder_tx_dust_exposure = inbound_stats.on_holder_tx_dust_exposure_msat + outbound_stats.on_holder_tx_dust_exposure_msat;
3464                         let counterparty_tx_dust_exposure = inbound_stats.on_counterparty_tx_dust_exposure_msat + outbound_stats.on_counterparty_tx_dust_exposure_msat;
3465                         if holder_tx_dust_exposure > self.get_max_dust_htlc_exposure_msat() {
3466                                 return Err(ChannelError::Close(format!("Peer sent update_fee with a feerate ({}) which may over-expose us to dust-in-flight on our own transactions (totaling {} msat)",
3467                                         msg.feerate_per_kw, holder_tx_dust_exposure)));
3468                         }
3469                         if counterparty_tx_dust_exposure > self.get_max_dust_htlc_exposure_msat() {
3470                                 return Err(ChannelError::Close(format!("Peer sent update_fee with a feerate ({}) which may over-expose us to dust-in-flight on our counterparty's transactions (totaling {} msat)",
3471                                         msg.feerate_per_kw, counterparty_tx_dust_exposure)));
3472                         }
3473                 }
3474                 Ok(())
3475         }
3476
3477         fn get_last_revoke_and_ack(&self) -> msgs::RevokeAndACK {
3478                 let next_per_commitment_point = self.holder_signer.get_per_commitment_point(self.cur_holder_commitment_transaction_number, &self.secp_ctx);
3479                 let per_commitment_secret = self.holder_signer.release_commitment_secret(self.cur_holder_commitment_transaction_number + 2);
3480                 msgs::RevokeAndACK {
3481                         channel_id: self.channel_id,
3482                         per_commitment_secret,
3483                         next_per_commitment_point,
3484                 }
3485         }
3486
3487         fn get_last_commitment_update<L: Deref>(&self, logger: &L) -> msgs::CommitmentUpdate where L::Target: Logger {
3488                 let mut update_add_htlcs = Vec::new();
3489                 let mut update_fulfill_htlcs = Vec::new();
3490                 let mut update_fail_htlcs = Vec::new();
3491                 let mut update_fail_malformed_htlcs = Vec::new();
3492
3493                 for htlc in self.pending_outbound_htlcs.iter() {
3494                         if let &OutboundHTLCState::LocalAnnounced(ref onion_packet) = &htlc.state {
3495                                 update_add_htlcs.push(msgs::UpdateAddHTLC {
3496                                         channel_id: self.channel_id(),
3497                                         htlc_id: htlc.htlc_id,
3498                                         amount_msat: htlc.amount_msat,
3499                                         payment_hash: htlc.payment_hash,
3500                                         cltv_expiry: htlc.cltv_expiry,
3501                                         onion_routing_packet: (**onion_packet).clone(),
3502                                 });
3503                         }
3504                 }
3505
3506                 for htlc in self.pending_inbound_htlcs.iter() {
3507                         if let &InboundHTLCState::LocalRemoved(ref reason) = &htlc.state {
3508                                 match reason {
3509                                         &InboundHTLCRemovalReason::FailRelay(ref err_packet) => {
3510                                                 update_fail_htlcs.push(msgs::UpdateFailHTLC {
3511                                                         channel_id: self.channel_id(),
3512                                                         htlc_id: htlc.htlc_id,
3513                                                         reason: err_packet.clone()
3514                                                 });
3515                                         },
3516                                         &InboundHTLCRemovalReason::FailMalformed((ref sha256_of_onion, ref failure_code)) => {
3517                                                 update_fail_malformed_htlcs.push(msgs::UpdateFailMalformedHTLC {
3518                                                         channel_id: self.channel_id(),
3519                                                         htlc_id: htlc.htlc_id,
3520                                                         sha256_of_onion: sha256_of_onion.clone(),
3521                                                         failure_code: failure_code.clone(),
3522                                                 });
3523                                         },
3524                                         &InboundHTLCRemovalReason::Fulfill(ref payment_preimage) => {
3525                                                 update_fulfill_htlcs.push(msgs::UpdateFulfillHTLC {
3526                                                         channel_id: self.channel_id(),
3527                                                         htlc_id: htlc.htlc_id,
3528                                                         payment_preimage: payment_preimage.clone(),
3529                                                 });
3530                                         },
3531                                 }
3532                         }
3533                 }
3534
3535                 let update_fee = if self.is_outbound() && self.pending_update_fee.is_some() {
3536                         Some(msgs::UpdateFee {
3537                                 channel_id: self.channel_id(),
3538                                 feerate_per_kw: self.pending_update_fee.unwrap().0,
3539                         })
3540                 } else { None };
3541
3542                 log_trace!(logger, "Regenerated latest commitment update in channel {} with{} {} update_adds, {} update_fulfills, {} update_fails, and {} update_fail_malformeds",
3543                                 log_bytes!(self.channel_id()), if update_fee.is_some() { " update_fee," } else { "" },
3544                                 update_add_htlcs.len(), update_fulfill_htlcs.len(), update_fail_htlcs.len(), update_fail_malformed_htlcs.len());
3545                 msgs::CommitmentUpdate {
3546                         update_add_htlcs, update_fulfill_htlcs, update_fail_htlcs, update_fail_malformed_htlcs, update_fee,
3547                         commitment_signed: self.send_commitment_no_state_update(logger).expect("It looks like we failed to re-generate a commitment_signed we had previously sent?").0,
3548                 }
3549         }
3550
3551         /// May panic if some calls other than message-handling calls (which will all Err immediately)
3552         /// have been called between remove_uncommitted_htlcs_and_mark_paused and this call.
3553         pub fn channel_reestablish<L: Deref>(&mut self, msg: &msgs::ChannelReestablish, logger: &L,
3554                 node_pk: PublicKey, genesis_block_hash: BlockHash, best_block: &BestBlock)
3555         -> Result<ReestablishResponses, ChannelError> where L::Target: Logger {
3556                 if self.channel_state & (ChannelState::PeerDisconnected as u32) == 0 {
3557                         // While BOLT 2 doesn't indicate explicitly we should error this channel here, it
3558                         // almost certainly indicates we are going to end up out-of-sync in some way, so we
3559                         // just close here instead of trying to recover.
3560                         return Err(ChannelError::Close("Peer sent a loose channel_reestablish not after reconnect".to_owned()));
3561                 }
3562
3563                 if msg.next_local_commitment_number >= INITIAL_COMMITMENT_NUMBER || msg.next_remote_commitment_number >= INITIAL_COMMITMENT_NUMBER ||
3564                         msg.next_local_commitment_number == 0 {
3565                         return Err(ChannelError::Close("Peer sent a garbage channel_reestablish".to_owned()));
3566                 }
3567
3568                 if msg.next_remote_commitment_number > 0 {
3569                         match msg.data_loss_protect {
3570                                 OptionalField::Present(ref data_loss) => {
3571                                         let expected_point = self.holder_signer.get_per_commitment_point(INITIAL_COMMITMENT_NUMBER - msg.next_remote_commitment_number + 1, &self.secp_ctx);
3572                                         let given_secret = SecretKey::from_slice(&data_loss.your_last_per_commitment_secret)
3573                                                 .map_err(|_| ChannelError::Close("Peer sent a garbage channel_reestablish with unparseable secret key".to_owned()))?;
3574                                         if expected_point != PublicKey::from_secret_key(&self.secp_ctx, &given_secret) {
3575                                                 return Err(ChannelError::Close("Peer sent a garbage channel_reestablish with secret key not matching the commitment height provided".to_owned()));
3576                                         }
3577                                         if msg.next_remote_commitment_number > INITIAL_COMMITMENT_NUMBER - self.cur_holder_commitment_transaction_number {
3578                                                 return Err(ChannelError::CloseDelayBroadcast(
3579                                                         "We have fallen behind - we have received proof that if we broadcast remote is going to claim our funds - we can't do any automated broadcasting".to_owned()
3580                                                 ));
3581                                         }
3582                                 },
3583                                 OptionalField::Absent => {}
3584                         }
3585                 }
3586
3587                 // Go ahead and unmark PeerDisconnected as various calls we may make check for it (and all
3588                 // remaining cases either succeed or ErrorMessage-fail).
3589                 self.channel_state &= !(ChannelState::PeerDisconnected as u32);
3590
3591                 let shutdown = if self.channel_state & (ChannelState::LocalShutdownSent as u32) != 0 {
3592                         assert!(self.shutdown_scriptpubkey.is_some());
3593                         Some(msgs::Shutdown {
3594                                 channel_id: self.channel_id,
3595                                 scriptpubkey: self.get_closing_scriptpubkey(),
3596                         })
3597                 } else { None };
3598
3599                 let announcement_sigs = self.get_announcement_sigs(node_pk, genesis_block_hash, best_block.height(), logger);
3600
3601                 if self.channel_state & (ChannelState::FundingSent as u32) == ChannelState::FundingSent as u32 {
3602                         // If we're waiting on a monitor update, we shouldn't re-send any funding_locked's.
3603                         if self.channel_state & (ChannelState::OurFundingLocked as u32) == 0 ||
3604                                         self.channel_state & (ChannelState::MonitorUpdateFailed as u32) != 0 {
3605                                 if msg.next_remote_commitment_number != 0 {
3606                                         return Err(ChannelError::Close("Peer claimed they saw a revoke_and_ack but we haven't sent funding_locked yet".to_owned()));
3607                                 }
3608                                 // Short circuit the whole handler as there is nothing we can resend them
3609                                 return Ok(ReestablishResponses {
3610                                         funding_locked: None,
3611                                         raa: None, commitment_update: None, mon_update: None,
3612                                         order: RAACommitmentOrder::CommitmentFirst,
3613                                         holding_cell_failed_htlcs: Vec::new(),
3614                                         shutdown, announcement_sigs,
3615                                 });
3616                         }
3617
3618                         // We have OurFundingLocked set!
3619                         let next_per_commitment_point = self.holder_signer.get_per_commitment_point(self.cur_holder_commitment_transaction_number, &self.secp_ctx);
3620                         return Ok(ReestablishResponses {
3621                                 funding_locked: Some(msgs::FundingLocked {
3622                                         channel_id: self.channel_id(),
3623                                         next_per_commitment_point,
3624                                         short_channel_id_alias: None,
3625                                 }),
3626                                 raa: None, commitment_update: None, mon_update: None,
3627                                 order: RAACommitmentOrder::CommitmentFirst,
3628                                 holding_cell_failed_htlcs: Vec::new(),
3629                                 shutdown, announcement_sigs,
3630                         });
3631                 }
3632
3633                 let required_revoke = if msg.next_remote_commitment_number + 1 == INITIAL_COMMITMENT_NUMBER - self.cur_holder_commitment_transaction_number {
3634                         // Remote isn't waiting on any RevokeAndACK from us!
3635                         // Note that if we need to repeat our FundingLocked we'll do that in the next if block.
3636                         None
3637                 } else if msg.next_remote_commitment_number + 1 == (INITIAL_COMMITMENT_NUMBER - 1) - self.cur_holder_commitment_transaction_number {
3638                         if self.channel_state & (ChannelState::MonitorUpdateFailed as u32) != 0 {
3639                                 self.monitor_pending_revoke_and_ack = true;
3640                                 None
3641                         } else {
3642                                 Some(self.get_last_revoke_and_ack())
3643                         }
3644                 } else {
3645                         return Err(ChannelError::Close("Peer attempted to reestablish channel with a very old local commitment transaction".to_owned()));
3646                 };
3647
3648                 // We increment cur_counterparty_commitment_transaction_number only upon receipt of
3649                 // revoke_and_ack, not on sending commitment_signed, so we add one if have
3650                 // AwaitingRemoteRevoke set, which indicates we sent a commitment_signed but haven't gotten
3651                 // the corresponding revoke_and_ack back yet.
3652                 let next_counterparty_commitment_number = INITIAL_COMMITMENT_NUMBER - self.cur_counterparty_commitment_transaction_number + if (self.channel_state & ChannelState::AwaitingRemoteRevoke as u32) != 0 { 1 } else { 0 };
3653
3654                 let funding_locked = if msg.next_local_commitment_number == 1 && INITIAL_COMMITMENT_NUMBER - self.cur_holder_commitment_transaction_number == 1 {
3655                         // We should never have to worry about MonitorUpdateFailed resending FundingLocked
3656                         let next_per_commitment_point = self.holder_signer.get_per_commitment_point(self.cur_holder_commitment_transaction_number, &self.secp_ctx);
3657                         Some(msgs::FundingLocked {
3658                                 channel_id: self.channel_id(),
3659                                 next_per_commitment_point,
3660                                 short_channel_id_alias: None,
3661                         })
3662                 } else { None };
3663
3664                 if msg.next_local_commitment_number == next_counterparty_commitment_number {
3665                         if required_revoke.is_some() {
3666                                 log_debug!(logger, "Reconnected channel {} with only lost outbound RAA", log_bytes!(self.channel_id()));
3667                         } else {
3668                                 log_debug!(logger, "Reconnected channel {} with no loss", log_bytes!(self.channel_id()));
3669                         }
3670
3671                         if (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::MonitorUpdateFailed as u32)) == 0 {
3672                                 // We're up-to-date and not waiting on a remote revoke (if we are our
3673                                 // channel_reestablish should result in them sending a revoke_and_ack), but we may
3674                                 // have received some updates while we were disconnected. Free the holding cell
3675                                 // now!
3676                                 match self.free_holding_cell_htlcs(logger) {
3677                                         Err(ChannelError::Close(msg)) => Err(ChannelError::Close(msg)),
3678                                         Err(ChannelError::Warn(_)) | Err(ChannelError::Ignore(_)) | Err(ChannelError::CloseDelayBroadcast(_)) =>
3679                                                 panic!("Got non-channel-failing result from free_holding_cell_htlcs"),
3680                                         Ok((Some((commitment_update, monitor_update)), holding_cell_failed_htlcs)) => {
3681                                                 Ok(ReestablishResponses {
3682                                                         funding_locked, shutdown, announcement_sigs,
3683                                                         raa: required_revoke,
3684                                                         commitment_update: Some(commitment_update),
3685                                                         order: self.resend_order.clone(),
3686                                                         mon_update: Some(monitor_update),
3687                                                         holding_cell_failed_htlcs,
3688                                                 })
3689                                         },
3690                                         Ok((None, holding_cell_failed_htlcs)) => {
3691                                                 Ok(ReestablishResponses {
3692                                                         funding_locked, shutdown, announcement_sigs,
3693                                                         raa: required_revoke,
3694                                                         commitment_update: None,
3695                                                         order: self.resend_order.clone(),
3696                                                         mon_update: None,
3697                                                         holding_cell_failed_htlcs,
3698                                                 })
3699                                         },
3700                                 }
3701                         } else {
3702                                 Ok(ReestablishResponses {
3703                                         funding_locked, shutdown, announcement_sigs,
3704                                         raa: required_revoke,
3705                                         commitment_update: None,
3706                                         order: self.resend_order.clone(),
3707                                         mon_update: None,
3708                                         holding_cell_failed_htlcs: Vec::new(),
3709                                 })
3710                         }
3711                 } else if msg.next_local_commitment_number == next_counterparty_commitment_number - 1 {
3712                         if required_revoke.is_some() {
3713                                 log_debug!(logger, "Reconnected channel {} with lost outbound RAA and lost remote commitment tx", log_bytes!(self.channel_id()));
3714                         } else {
3715                                 log_debug!(logger, "Reconnected channel {} with only lost remote commitment tx", log_bytes!(self.channel_id()));
3716                         }
3717
3718                         if self.channel_state & (ChannelState::MonitorUpdateFailed as u32) != 0 {
3719                                 self.monitor_pending_commitment_signed = true;
3720                                 Ok(ReestablishResponses {
3721                                         funding_locked, shutdown, announcement_sigs,
3722                                         commitment_update: None, raa: None, mon_update: None,
3723                                         order: self.resend_order.clone(),
3724                                         holding_cell_failed_htlcs: Vec::new(),
3725                                 })
3726                         } else {
3727                                 Ok(ReestablishResponses {
3728                                         funding_locked, shutdown, announcement_sigs,
3729                                         raa: required_revoke,
3730                                         commitment_update: Some(self.get_last_commitment_update(logger)),
3731                                         order: self.resend_order.clone(),
3732                                         mon_update: None,
3733                                         holding_cell_failed_htlcs: Vec::new(),
3734                                 })
3735                         }
3736                 } else {
3737                         Err(ChannelError::Close("Peer attempted to reestablish channel with a very old remote commitment transaction".to_owned()))
3738                 }
3739         }
3740
3741         /// Calculates and returns our minimum and maximum closing transaction fee amounts, in whole
3742         /// satoshis. The amounts remain consistent unless a peer disconnects/reconnects or we restart,
3743         /// at which point they will be recalculated.
3744         fn calculate_closing_fee_limits<F: Deref>(&mut self, fee_estimator: &F) -> (u64, u64)
3745                 where F::Target: FeeEstimator
3746         {
3747                 if let Some((min, max)) = self.closing_fee_limits { return (min, max); }
3748
3749                 // Propose a range from our current Background feerate to our Normal feerate plus our
3750                 // force_close_avoidance_max_fee_satoshis.
3751                 // If we fail to come to consensus, we'll have to force-close.
3752                 let mut proposed_feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
3753                 let normal_feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);
3754                 let mut proposed_max_feerate = if self.is_outbound() { normal_feerate } else { u32::max_value() };
3755
3756                 // The spec requires that (when the channel does not have anchors) we only send absolute
3757                 // channel fees no greater than the absolute channel fee on the current commitment
3758                 // transaction. It's unclear *which* commitment transaction this refers to, and there isn't
3759                 // very good reason to apply such a limit in any case. We don't bother doing so, risking
3760                 // some force-closure by old nodes, but we wanted to close the channel anyway.
3761
3762                 if let Some(target_feerate) = self.target_closing_feerate_sats_per_kw {
3763                         let min_feerate = if self.is_outbound() { target_feerate } else { cmp::min(self.feerate_per_kw, target_feerate) };
3764                         proposed_feerate = cmp::max(proposed_feerate, min_feerate);
3765                         proposed_max_feerate = cmp::max(proposed_max_feerate, min_feerate);
3766                 }
3767
3768                 // Note that technically we could end up with a lower minimum fee if one sides' balance is
3769                 // below our dust limit, causing the output to disappear. We don't bother handling this
3770                 // case, however, as this should only happen if a channel is closed before any (material)
3771                 // payments have been made on it. This may cause slight fee overpayment and/or failure to
3772                 // come to consensus with our counterparty on appropriate fees, however it should be a
3773                 // relatively rare case. We can revisit this later, though note that in order to determine
3774                 // if the funders' output is dust we have to know the absolute fee we're going to use.
3775                 let tx_weight = self.get_closing_transaction_weight(Some(&self.get_closing_scriptpubkey()), Some(self.counterparty_shutdown_scriptpubkey.as_ref().unwrap()));
3776                 let proposed_total_fee_satoshis = proposed_feerate as u64 * tx_weight / 1000;
3777                 let proposed_max_total_fee_satoshis = if self.is_outbound() {
3778                                 // We always add force_close_avoidance_max_fee_satoshis to our normal
3779                                 // feerate-calculated fee, but allow the max to be overridden if we're using a
3780                                 // target feerate-calculated fee.
3781                                 cmp::max(normal_feerate as u64 * tx_weight / 1000 + self.config.force_close_avoidance_max_fee_satoshis,
3782                                         proposed_max_feerate as u64 * tx_weight / 1000)
3783                         } else {
3784                                 self.channel_value_satoshis - (self.value_to_self_msat + 999) / 1000
3785                         };
3786
3787                 self.closing_fee_limits = Some((proposed_total_fee_satoshis, proposed_max_total_fee_satoshis));
3788                 self.closing_fee_limits.clone().unwrap()
3789         }
3790
3791         /// Returns true if we're ready to commence the closing_signed negotiation phase. This is true
3792         /// after both sides have exchanged a `shutdown` message and all HTLCs have been drained. At
3793         /// this point if we're the funder we should send the initial closing_signed, and in any case
3794         /// shutdown should complete within a reasonable timeframe.
3795         fn closing_negotiation_ready(&self) -> bool {
3796                 self.pending_inbound_htlcs.is_empty() && self.pending_outbound_htlcs.is_empty() &&
3797                         self.channel_state &
3798                                 (BOTH_SIDES_SHUTDOWN_MASK | ChannelState::AwaitingRemoteRevoke as u32 |
3799                                  ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateFailed as u32)
3800                                 == BOTH_SIDES_SHUTDOWN_MASK &&
3801                         self.pending_update_fee.is_none()
3802         }
3803
3804         /// Checks if the closing_signed negotiation is making appropriate progress, possibly returning
3805         /// an Err if no progress is being made and the channel should be force-closed instead.
3806         /// Should be called on a one-minute timer.
3807         pub fn timer_check_closing_negotiation_progress(&mut self) -> Result<(), ChannelError> {
3808                 if self.closing_negotiation_ready() {
3809                         if self.closing_signed_in_flight {
3810                                 return Err(ChannelError::Close("closing_signed negotiation failed to finish within two timer ticks".to_owned()));
3811                         } else {
3812                                 self.closing_signed_in_flight = true;
3813                         }
3814                 }
3815                 Ok(())
3816         }
3817
3818         pub fn maybe_propose_closing_signed<F: Deref, L: Deref>(&mut self, fee_estimator: &F, logger: &L)
3819                 -> Result<(Option<msgs::ClosingSigned>, Option<Transaction>), ChannelError>
3820                 where F::Target: FeeEstimator, L::Target: Logger
3821         {
3822                 if self.last_sent_closing_fee.is_some() || !self.closing_negotiation_ready() {
3823                         return Ok((None, None));
3824                 }
3825
3826                 if !self.is_outbound() {
3827                         if let Some(msg) = &self.pending_counterparty_closing_signed.take() {
3828                                 return self.closing_signed(fee_estimator, &msg);
3829                         }
3830                         return Ok((None, None));
3831                 }
3832
3833                 let (our_min_fee, our_max_fee) = self.calculate_closing_fee_limits(fee_estimator);
3834
3835                 assert!(self.shutdown_scriptpubkey.is_some());
3836                 let (closing_tx, total_fee_satoshis) = self.build_closing_transaction(our_min_fee, false);
3837                 log_trace!(logger, "Proposing initial closing_signed for our counterparty with a fee range of {}-{} sat (with initial proposal {} sats)",
3838                         our_min_fee, our_max_fee, total_fee_satoshis);
3839
3840                 let sig = self.holder_signer
3841                         .sign_closing_transaction(&closing_tx, &self.secp_ctx)
3842                         .map_err(|()| ChannelError::Close("Failed to get signature for closing transaction.".to_owned()))?;
3843
3844                 self.last_sent_closing_fee = Some((total_fee_satoshis, sig.clone()));
3845                 Ok((Some(msgs::ClosingSigned {
3846                         channel_id: self.channel_id,
3847                         fee_satoshis: total_fee_satoshis,
3848                         signature: sig,
3849                         fee_range: Some(msgs::ClosingSignedFeeRange {
3850                                 min_fee_satoshis: our_min_fee,
3851                                 max_fee_satoshis: our_max_fee,
3852                         }),
3853                 }), None))
3854         }
3855
3856         pub fn shutdown<K: Deref>(
3857                 &mut self, keys_provider: &K, their_features: &InitFeatures, msg: &msgs::Shutdown
3858         ) -> Result<(Option<msgs::Shutdown>, Option<ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>), ChannelError>
3859         where K::Target: KeysInterface<Signer = Signer>
3860         {
3861                 if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
3862                         return Err(ChannelError::Close("Peer sent shutdown when we needed a channel_reestablish".to_owned()));
3863                 }
3864                 if self.channel_state < ChannelState::FundingSent as u32 {
3865                         // Spec says we should fail the connection, not the channel, but that's nonsense, there
3866                         // are plenty of reasons you may want to fail a channel pre-funding, and spec says you
3867                         // can do that via error message without getting a connection fail anyway...
3868                         return Err(ChannelError::Close("Peer sent shutdown pre-funding generation".to_owned()));
3869                 }
3870                 for htlc in self.pending_inbound_htlcs.iter() {
3871                         if let InboundHTLCState::RemoteAnnounced(_) = htlc.state {
3872                                 return Err(ChannelError::Close("Got shutdown with remote pending HTLCs".to_owned()));
3873                         }
3874                 }
3875                 assert_eq!(self.channel_state & ChannelState::ShutdownComplete as u32, 0);
3876
3877                 if !script::is_bolt2_compliant(&msg.scriptpubkey, their_features) {
3878                         return Err(ChannelError::Close(format!("Got a nonstandard scriptpubkey ({}) from remote peer", msg.scriptpubkey.to_bytes().to_hex())));
3879                 }
3880
3881                 if self.counterparty_shutdown_scriptpubkey.is_some() {
3882                         if Some(&msg.scriptpubkey) != self.counterparty_shutdown_scriptpubkey.as_ref() {
3883                                 return Err(ChannelError::Close(format!("Got shutdown request with a scriptpubkey ({}) which did not match their previous scriptpubkey.", msg.scriptpubkey.to_bytes().to_hex())));
3884                         }
3885                 } else {
3886                         self.counterparty_shutdown_scriptpubkey = Some(msg.scriptpubkey.clone());
3887                 }
3888
3889                 // If we have any LocalAnnounced updates we'll probably just get back an update_fail_htlc
3890                 // immediately after the commitment dance, but we can send a Shutdown because we won't send
3891                 // any further commitment updates after we set LocalShutdownSent.
3892                 let send_shutdown = (self.channel_state & ChannelState::LocalShutdownSent as u32) != ChannelState::LocalShutdownSent as u32;
3893
3894                 let update_shutdown_script = match self.shutdown_scriptpubkey {
3895                         Some(_) => false,
3896                         None => {
3897                                 assert!(send_shutdown);
3898                                 let shutdown_scriptpubkey = keys_provider.get_shutdown_scriptpubkey();
3899                                 if !shutdown_scriptpubkey.is_compatible(their_features) {
3900                                         return Err(ChannelError::Close(format!("Provided a scriptpubkey format not accepted by peer: {}", shutdown_scriptpubkey)));
3901                                 }
3902                                 self.shutdown_scriptpubkey = Some(shutdown_scriptpubkey);
3903                                 true
3904                         },
3905                 };
3906
3907                 // From here on out, we may not fail!
3908
3909                 self.channel_state |= ChannelState::RemoteShutdownSent as u32;
3910                 self.update_time_counter += 1;
3911
3912                 let monitor_update = if update_shutdown_script {
3913                         self.latest_monitor_update_id += 1;
3914                         Some(ChannelMonitorUpdate {
3915                                 update_id: self.latest_monitor_update_id,
3916                                 updates: vec![ChannelMonitorUpdateStep::ShutdownScript {
3917                                         scriptpubkey: self.get_closing_scriptpubkey(),
3918                                 }],
3919                         })
3920                 } else { None };
3921                 let shutdown = if send_shutdown {
3922                         Some(msgs::Shutdown {
3923                                 channel_id: self.channel_id,
3924                                 scriptpubkey: self.get_closing_scriptpubkey(),
3925                         })
3926                 } else { None };
3927
3928                 // We can't send our shutdown until we've committed all of our pending HTLCs, but the
3929                 // remote side is unlikely to accept any new HTLCs, so we go ahead and "free" any holding
3930                 // cell HTLCs and return them to fail the payment.
3931                 self.holding_cell_update_fee = None;
3932                 let mut dropped_outbound_htlcs = Vec::with_capacity(self.holding_cell_htlc_updates.len());
3933                 self.holding_cell_htlc_updates.retain(|htlc_update| {
3934                         match htlc_update {
3935                                 &HTLCUpdateAwaitingACK::AddHTLC { ref payment_hash, ref source, .. } => {
3936                                         dropped_outbound_htlcs.push((source.clone(), payment_hash.clone()));
3937                                         false
3938                                 },
3939                                 _ => true
3940                         }
3941                 });
3942
3943                 self.channel_state |= ChannelState::LocalShutdownSent as u32;
3944                 self.update_time_counter += 1;
3945
3946                 Ok((shutdown, monitor_update, dropped_outbound_htlcs))
3947         }
3948
3949         fn build_signed_closing_transaction(&self, closing_tx: &ClosingTransaction, counterparty_sig: &Signature, sig: &Signature) -> Transaction {
3950                 let mut tx = closing_tx.trust().built_transaction().clone();
3951
3952                 tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
3953
3954                 let funding_key = self.get_holder_pubkeys().funding_pubkey.serialize();
3955                 let counterparty_funding_key = self.counterparty_funding_pubkey().serialize();
3956                 if funding_key[..] < counterparty_funding_key[..] {
3957                         tx.input[0].witness.push(sig.serialize_der().to_vec());
3958                         tx.input[0].witness.push(counterparty_sig.serialize_der().to_vec());
3959                 } else {
3960                         tx.input[0].witness.push(counterparty_sig.serialize_der().to_vec());
3961                         tx.input[0].witness.push(sig.serialize_der().to_vec());
3962                 }
3963                 tx.input[0].witness[1].push(SigHashType::All as u8);
3964                 tx.input[0].witness[2].push(SigHashType::All as u8);
3965
3966                 tx.input[0].witness.push(self.get_funding_redeemscript().into_bytes());
3967                 tx
3968         }
3969
3970         pub fn closing_signed<F: Deref>(&mut self, fee_estimator: &F, msg: &msgs::ClosingSigned) -> Result<(Option<msgs::ClosingSigned>, Option<Transaction>), ChannelError>
3971                 where F::Target: FeeEstimator
3972         {
3973                 if self.channel_state & BOTH_SIDES_SHUTDOWN_MASK != BOTH_SIDES_SHUTDOWN_MASK {
3974                         return Err(ChannelError::Close("Remote end sent us a closing_signed before both sides provided a shutdown".to_owned()));
3975                 }
3976                 if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
3977                         return Err(ChannelError::Close("Peer sent closing_signed when we needed a channel_reestablish".to_owned()));
3978                 }
3979                 if !self.pending_inbound_htlcs.is_empty() || !self.pending_outbound_htlcs.is_empty() {
3980                         return Err(ChannelError::Close("Remote end sent us a closing_signed while there were still pending HTLCs".to_owned()));
3981                 }
3982                 if msg.fee_satoshis > 21_000_000 * 1_0000_0000 { //this is required to stop potential overflow in build_closing_transaction
3983                         return Err(ChannelError::Close("Remote tried to send us a closing tx with > 21 million BTC fee".to_owned()));
3984                 }
3985
3986                 if self.is_outbound() && self.last_sent_closing_fee.is_none() {
3987                         return Err(ChannelError::Close("Remote tried to send a closing_signed when we were supposed to propose the first one".to_owned()));
3988                 }
3989
3990                 if self.channel_state & ChannelState::MonitorUpdateFailed as u32 != 0 {
3991                         self.pending_counterparty_closing_signed = Some(msg.clone());
3992                         return Ok((None, None));
3993                 }
3994
3995                 let funding_redeemscript = self.get_funding_redeemscript();
3996                 let (mut closing_tx, used_total_fee) = self.build_closing_transaction(msg.fee_satoshis, false);
3997                 if used_total_fee != msg.fee_satoshis {
3998                         return Err(ChannelError::Close(format!("Remote sent us a closing_signed with a fee other than the value they can claim. Fee in message: {}. Actual closing tx fee: {}", msg.fee_satoshis, used_total_fee)));
3999                 }
4000                 let sighash = closing_tx.trust().get_sighash_all(&funding_redeemscript, self.channel_value_satoshis);
4001
4002                 match self.secp_ctx.verify(&sighash, &msg.signature, &self.get_counterparty_pubkeys().funding_pubkey) {
4003                         Ok(_) => {},
4004                         Err(_e) => {
4005                                 // The remote end may have decided to revoke their output due to inconsistent dust
4006                                 // limits, so check for that case by re-checking the signature here.
4007                                 closing_tx = self.build_closing_transaction(msg.fee_satoshis, true).0;
4008                                 let sighash = closing_tx.trust().get_sighash_all(&funding_redeemscript, self.channel_value_satoshis);
4009                                 secp_check!(self.secp_ctx.verify(&sighash, &msg.signature, self.counterparty_funding_pubkey()), "Invalid closing tx signature from peer".to_owned());
4010                         },
4011                 };
4012
4013                 for outp in closing_tx.trust().built_transaction().output.iter() {
4014                         if !outp.script_pubkey.is_witness_program() && outp.value < MAX_STD_OUTPUT_DUST_LIMIT_SATOSHIS {
4015                                 return Err(ChannelError::Close("Remote sent us a closing_signed with a dust output. Always use segwit closing scripts!".to_owned()));
4016                         }
4017                 }
4018
4019                 assert!(self.shutdown_scriptpubkey.is_some());
4020                 if let Some((last_fee, sig)) = self.last_sent_closing_fee {
4021                         if last_fee == msg.fee_satoshis {
4022                                 let tx = self.build_signed_closing_transaction(&mut closing_tx, &msg.signature, &sig);
4023                                 self.channel_state = ChannelState::ShutdownComplete as u32;
4024                                 self.update_time_counter += 1;
4025                                 return Ok((None, Some(tx)));
4026                         }
4027                 }
4028
4029                 let (our_min_fee, our_max_fee) = self.calculate_closing_fee_limits(fee_estimator);
4030
4031                 macro_rules! propose_fee {
4032                         ($new_fee: expr) => {
4033                                 let (closing_tx, used_fee) = if $new_fee == msg.fee_satoshis {
4034                                         (closing_tx, $new_fee)
4035                                 } else {
4036                                         self.build_closing_transaction($new_fee, false)
4037                                 };
4038
4039                                 let sig = self.holder_signer
4040                                         .sign_closing_transaction(&closing_tx, &self.secp_ctx)
4041                                         .map_err(|_| ChannelError::Close("External signer refused to sign closing transaction".to_owned()))?;
4042
4043                                 let signed_tx = if $new_fee == msg.fee_satoshis {
4044                                         self.channel_state = ChannelState::ShutdownComplete as u32;
4045                                         self.update_time_counter += 1;
4046                                         let tx = self.build_signed_closing_transaction(&closing_tx, &msg.signature, &sig);
4047                                         Some(tx)
4048                                 } else { None };
4049
4050                                 self.last_sent_closing_fee = Some((used_fee, sig.clone()));
4051                                 return Ok((Some(msgs::ClosingSigned {
4052                                         channel_id: self.channel_id,
4053                                         fee_satoshis: used_fee,
4054                                         signature: sig,
4055                                         fee_range: Some(msgs::ClosingSignedFeeRange {
4056                                                 min_fee_satoshis: our_min_fee,
4057                                                 max_fee_satoshis: our_max_fee,
4058                                         }),
4059                                 }), signed_tx))
4060                         }
4061                 }
4062
4063                 if let Some(msgs::ClosingSignedFeeRange { min_fee_satoshis, max_fee_satoshis }) = msg.fee_range {
4064                         if msg.fee_satoshis < min_fee_satoshis || msg.fee_satoshis > max_fee_satoshis {
4065                                 return Err(ChannelError::Close(format!("Peer sent a bogus closing_signed - suggested fee of {} sat was not in their desired range of {} sat - {} sat", msg.fee_satoshis, min_fee_satoshis, max_fee_satoshis)));
4066                         }
4067                         if max_fee_satoshis < our_min_fee {
4068                                 return Err(ChannelError::Warn(format!("Unable to come to consensus about closing feerate, remote's max fee ({} sat) was smaller than our min fee ({} sat)", max_fee_satoshis, our_min_fee)));
4069                         }
4070                         if min_fee_satoshis > our_max_fee {
4071                                 return Err(ChannelError::Warn(format!("Unable to come to consensus about closing feerate, remote's min fee ({} sat) was greater than our max fee ({} sat)", min_fee_satoshis, our_max_fee)));
4072                         }
4073
4074                         if !self.is_outbound() {
4075                                 // They have to pay, so pick the highest fee in the overlapping range.
4076                                 // We should never set an upper bound aside from their full balance
4077                                 debug_assert_eq!(our_max_fee, self.channel_value_satoshis - (self.value_to_self_msat + 999) / 1000);
4078                                 propose_fee!(cmp::min(max_fee_satoshis, our_max_fee));
4079                         } else {
4080                                 if msg.fee_satoshis < our_min_fee || msg.fee_satoshis > our_max_fee {
4081                                         return Err(ChannelError::Close(format!("Peer sent a bogus closing_signed - suggested fee of {} sat was not in our desired range of {} sat - {} sat after we informed them of our range.",
4082                                                 msg.fee_satoshis, our_min_fee, our_max_fee)));
4083                                 }
4084                                 // The proposed fee is in our acceptable range, accept it and broadcast!
4085                                 propose_fee!(msg.fee_satoshis);
4086                         }
4087                 } else {
4088                         // Old fee style negotiation. We don't bother to enforce whether they are complying
4089                         // with the "making progress" requirements, we just comply and hope for the best.
4090                         if let Some((last_fee, _)) = self.last_sent_closing_fee {
4091                                 if msg.fee_satoshis > last_fee {
4092                                         if msg.fee_satoshis < our_max_fee {
4093                                                 propose_fee!(msg.fee_satoshis);
4094                                         } else if last_fee < our_max_fee {
4095                                                 propose_fee!(our_max_fee);
4096                                         } else {
4097                                                 return Err(ChannelError::Close(format!("Unable to come to consensus about closing feerate, remote wants something ({} sat) higher than our max fee ({} sat)", msg.fee_satoshis, our_max_fee)));
4098                                         }
4099                                 } else {
4100                                         if msg.fee_satoshis > our_min_fee {
4101                                                 propose_fee!(msg.fee_satoshis);
4102                                         } else if last_fee > our_min_fee {
4103                                                 propose_fee!(our_min_fee);
4104                                         } else {
4105                                                 return Err(ChannelError::Close(format!("Unable to come to consensus about closing feerate, remote wants something ({} sat) lower than our min fee ({} sat)", msg.fee_satoshis, our_min_fee)));
4106                                         }
4107                                 }
4108                         } else {
4109                                 if msg.fee_satoshis < our_min_fee {
4110                                         propose_fee!(our_min_fee);
4111                                 } else if msg.fee_satoshis > our_max_fee {
4112                                         propose_fee!(our_max_fee);
4113                                 } else {
4114                                         propose_fee!(msg.fee_satoshis);
4115                                 }
4116                         }
4117                 }
4118         }
4119
4120         // Public utilities:
4121
4122         pub fn channel_id(&self) -> [u8; 32] {
4123                 self.channel_id
4124         }
4125
4126         pub fn minimum_depth(&self) -> Option<u32> {
4127                 self.minimum_depth
4128         }
4129
4130         /// Gets the "user_id" value passed into the construction of this channel. It has no special
4131         /// meaning and exists only to allow users to have a persistent identifier of a channel.
4132         pub fn get_user_id(&self) -> u64 {
4133                 self.user_id
4134         }
4135
4136         /// Guaranteed to be Some after both FundingLocked messages have been exchanged (and, thus,
4137         /// is_usable() returns true).
4138         /// Allowed in any state (including after shutdown)
4139         pub fn get_short_channel_id(&self) -> Option<u64> {
4140                 self.short_channel_id
4141         }
4142
4143         /// Allowed in any state (including after shutdown)
4144         pub fn get_latest_inbound_scid_alias(&self) -> Option<u64> {
4145                 self.latest_inbound_scid_alias
4146         }
4147
4148         /// Returns the funding_txo we either got from our peer, or were given by
4149         /// get_outbound_funding_created.
4150         pub fn get_funding_txo(&self) -> Option<OutPoint> {
4151                 self.channel_transaction_parameters.funding_outpoint
4152         }
4153
4154         fn get_holder_selected_contest_delay(&self) -> u16 {
4155                 self.channel_transaction_parameters.holder_selected_contest_delay
4156         }
4157
4158         fn get_holder_pubkeys(&self) -> &ChannelPublicKeys {
4159                 &self.channel_transaction_parameters.holder_pubkeys
4160         }
4161
4162         pub fn get_counterparty_selected_contest_delay(&self) -> Option<u16> {
4163                 self.channel_transaction_parameters.counterparty_parameters
4164                         .as_ref().map(|params| params.selected_contest_delay)
4165         }
4166
4167         fn get_counterparty_pubkeys(&self) -> &ChannelPublicKeys {
4168                 &self.channel_transaction_parameters.counterparty_parameters.as_ref().unwrap().pubkeys
4169         }
4170
4171         /// Allowed in any state (including after shutdown)
4172         pub fn get_counterparty_node_id(&self) -> PublicKey {
4173                 self.counterparty_node_id
4174         }
4175
4176         /// Allowed in any state (including after shutdown)
4177         #[cfg(test)]
4178         pub fn get_holder_htlc_minimum_msat(&self) -> u64 {
4179                 self.holder_htlc_minimum_msat
4180         }
4181
4182         /// Allowed in any state (including after shutdown)
4183         pub fn get_announced_htlc_max_msat(&self) -> u64 {
4184                 return cmp::min(
4185                         // Upper bound by capacity. We make it a bit less than full capacity to prevent attempts
4186                         // to use full capacity. This is an effort to reduce routing failures, because in many cases
4187                         // channel might have been used to route very small values (either by honest users or as DoS).
4188                         self.channel_value_satoshis * 1000 * 9 / 10,
4189
4190                         self.holder_max_htlc_value_in_flight_msat
4191                 );
4192         }
4193
4194         /// Allowed in any state (including after shutdown)
4195         pub fn get_counterparty_htlc_minimum_msat(&self) -> u64 {
4196                 self.counterparty_htlc_minimum_msat
4197         }
4198
4199         pub fn get_value_satoshis(&self) -> u64 {
4200                 self.channel_value_satoshis
4201         }
4202
4203         pub fn get_fee_proportional_millionths(&self) -> u32 {
4204                 self.config.forwarding_fee_proportional_millionths
4205         }
4206
4207         pub fn get_cltv_expiry_delta(&self) -> u16 {
4208                 cmp::max(self.config.cltv_expiry_delta, MIN_CLTV_EXPIRY_DELTA)
4209         }
4210
4211         pub fn get_max_dust_htlc_exposure_msat(&self) -> u64 {
4212                 self.config.max_dust_htlc_exposure_msat
4213         }
4214
4215         pub fn get_feerate(&self) -> u32 {
4216                 self.feerate_per_kw
4217         }
4218
4219         pub fn get_dust_buffer_feerate(&self, outbound_feerate_update: Option<u32>) -> u32 {
4220                 // When calculating our exposure to dust HTLCs, we assume that the channel feerate
4221                 // may, at any point, increase by at least 10 sat/vB (i.e 2530 sat/kWU) or 25%,
4222                 // whichever is higher. This ensures that we aren't suddenly exposed to significantly
4223                 // more dust balance if the feerate increases when we have several HTLCs pending
4224                 // which are near the dust limit.
4225                 let mut feerate_per_kw = self.feerate_per_kw;
4226                 // If there's a pending update fee, use it to ensure we aren't under-estimating
4227                 // potential feerate updates coming soon.
4228                 if let Some((feerate, _)) = self.pending_update_fee {
4229                         feerate_per_kw = cmp::max(feerate_per_kw, feerate);
4230                 }
4231                 if let Some(feerate) = outbound_feerate_update {
4232                         feerate_per_kw = cmp::max(feerate_per_kw, feerate);
4233                 }
4234                 cmp::max(2530, feerate_per_kw * 1250 / 1000)
4235         }
4236
4237         pub fn get_cur_holder_commitment_transaction_number(&self) -> u64 {
4238                 self.cur_holder_commitment_transaction_number + 1
4239         }
4240
4241         pub fn get_cur_counterparty_commitment_transaction_number(&self) -> u64 {
4242                 self.cur_counterparty_commitment_transaction_number + 1 - if self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32) != 0 { 1 } else { 0 }
4243         }
4244
4245         pub fn get_revoked_counterparty_commitment_transaction_number(&self) -> u64 {
4246                 self.cur_counterparty_commitment_transaction_number + 2
4247         }
4248
4249         #[cfg(test)]
4250         pub fn get_signer(&self) -> &Signer {
4251                 &self.holder_signer
4252         }
4253
4254         #[cfg(test)]
4255         pub fn get_value_stat(&self) -> ChannelValueStat {
4256                 ChannelValueStat {
4257                         value_to_self_msat: self.value_to_self_msat,
4258                         channel_value_msat: self.channel_value_satoshis * 1000,
4259                         channel_reserve_msat: self.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000,
4260                         pending_outbound_htlcs_amount_msat: self.pending_outbound_htlcs.iter().map(|ref h| h.amount_msat).sum::<u64>(),
4261                         pending_inbound_htlcs_amount_msat: self.pending_inbound_htlcs.iter().map(|ref h| h.amount_msat).sum::<u64>(),
4262                         holding_cell_outbound_amount_msat: {
4263                                 let mut res = 0;
4264                                 for h in self.holding_cell_htlc_updates.iter() {
4265                                         match h {
4266                                                 &HTLCUpdateAwaitingACK::AddHTLC{amount_msat, .. } => {
4267                                                         res += amount_msat;
4268                                                 }
4269                                                 _ => {}
4270                                         }
4271                                 }
4272                                 res
4273                         },
4274                         counterparty_max_htlc_value_in_flight_msat: self.counterparty_max_htlc_value_in_flight_msat,
4275                         counterparty_dust_limit_msat: self.counterparty_dust_limit_satoshis * 1000,
4276                 }
4277         }
4278
4279         /// Allowed in any state (including after shutdown)
4280         pub fn get_update_time_counter(&self) -> u32 {
4281                 self.update_time_counter
4282         }
4283
4284         pub fn get_latest_monitor_update_id(&self) -> u64 {
4285                 self.latest_monitor_update_id
4286         }
4287
4288         pub fn should_announce(&self) -> bool {
4289                 self.config.announced_channel
4290         }
4291
4292         pub fn is_outbound(&self) -> bool {
4293                 self.channel_transaction_parameters.is_outbound_from_holder
4294         }
4295
4296         /// Gets the fee we'd want to charge for adding an HTLC output to this Channel
4297         /// Allowed in any state (including after shutdown)
4298         pub fn get_outbound_forwarding_fee_base_msat(&self) -> u32 {
4299                 self.config.forwarding_fee_base_msat
4300         }
4301
4302         /// Returns true if we've ever received a message from the remote end for this Channel
4303         pub fn have_received_message(&self) -> bool {
4304                 self.channel_state > (ChannelState::OurInitSent as u32)
4305         }
4306
4307         /// Returns true if this channel is fully established and not known to be closing.
4308         /// Allowed in any state (including after shutdown)
4309         pub fn is_usable(&self) -> bool {
4310                 let mask = ChannelState::ChannelFunded as u32 | BOTH_SIDES_SHUTDOWN_MASK;
4311                 (self.channel_state & mask) == (ChannelState::ChannelFunded as u32) && !self.monitor_pending_funding_locked
4312         }
4313
4314         /// Returns true if this channel is currently available for use. This is a superset of
4315         /// is_usable() and considers things like the channel being temporarily disabled.
4316         /// Allowed in any state (including after shutdown)
4317         pub fn is_live(&self) -> bool {
4318                 self.is_usable() && (self.channel_state & (ChannelState::PeerDisconnected as u32) == 0)
4319         }
4320
4321         /// Returns true if this channel has been marked as awaiting a monitor update to move forward.
4322         /// Allowed in any state (including after shutdown)
4323         pub fn is_awaiting_monitor_update(&self) -> bool {
4324                 (self.channel_state & ChannelState::MonitorUpdateFailed as u32) != 0
4325         }
4326
4327         /// Returns true if funding_created was sent/received.
4328         pub fn is_funding_initiated(&self) -> bool {
4329                 self.channel_state >= ChannelState::FundingSent as u32
4330         }
4331
4332         /// Returns true if our peer has either initiated or agreed to shut down the channel.
4333         pub fn received_shutdown(&self) -> bool {
4334                 (self.channel_state & ChannelState::RemoteShutdownSent as u32) != 0
4335         }
4336
4337         /// Returns true if we either initiated or agreed to shut down the channel.
4338         pub fn sent_shutdown(&self) -> bool {
4339                 (self.channel_state & ChannelState::LocalShutdownSent as u32) != 0
4340         }
4341
4342         /// Returns true if this channel is fully shut down. True here implies that no further actions
4343         /// may/will be taken on this channel, and thus this object should be freed. Any future changes
4344         /// will be handled appropriately by the chain monitor.
4345         pub fn is_shutdown(&self) -> bool {
4346                 if (self.channel_state & ChannelState::ShutdownComplete as u32) == ChannelState::ShutdownComplete as u32  {
4347                         assert!(self.channel_state == ChannelState::ShutdownComplete as u32);
4348                         true
4349                 } else { false }
4350         }
4351
4352         pub fn channel_update_status(&self) -> ChannelUpdateStatus {
4353                 self.channel_update_status
4354         }
4355
4356         pub fn set_channel_update_status(&mut self, status: ChannelUpdateStatus) {
4357                 self.update_time_counter += 1;
4358                 self.channel_update_status = status;
4359         }
4360
4361         fn check_get_funding_locked(&mut self, height: u32) -> Option<msgs::FundingLocked> {
4362                 if self.funding_tx_confirmation_height == 0 {
4363                         return None;
4364                 }
4365
4366                 let funding_tx_confirmations = height as i64 - self.funding_tx_confirmation_height as i64 + 1;
4367                 if funding_tx_confirmations <= 0 {
4368                         self.funding_tx_confirmation_height = 0;
4369                 }
4370
4371                 if funding_tx_confirmations < self.minimum_depth.unwrap_or(0) as i64 {
4372                         return None;
4373                 }
4374
4375                 let non_shutdown_state = self.channel_state & (!MULTI_STATE_FLAGS);
4376                 let need_commitment_update = if non_shutdown_state == ChannelState::FundingSent as u32 {
4377                         self.channel_state |= ChannelState::OurFundingLocked as u32;
4378                         true
4379                 } else if non_shutdown_state == (ChannelState::FundingSent as u32 | ChannelState::TheirFundingLocked as u32) {
4380                         self.channel_state = ChannelState::ChannelFunded as u32 | (self.channel_state & MULTI_STATE_FLAGS);
4381                         self.update_time_counter += 1;
4382                         true
4383                 } else if non_shutdown_state == (ChannelState::FundingSent as u32 | ChannelState::OurFundingLocked as u32) {
4384                         // We got a reorg but not enough to trigger a force close, just ignore.
4385                         false
4386                 } else if self.channel_state < ChannelState::ChannelFunded as u32 {
4387                         panic!("Started confirming a channel in a state pre-FundingSent?: {}", self.channel_state);
4388                 } else {
4389                         // We got a reorg but not enough to trigger a force close, just ignore.
4390                         false
4391                 };
4392
4393                 if need_commitment_update {
4394                         if self.channel_state & (ChannelState::MonitorUpdateFailed as u32) == 0 {
4395                                 if self.channel_state & (ChannelState::PeerDisconnected as u32) == 0 {
4396                                         let next_per_commitment_point = self.holder_signer.get_per_commitment_point(self.cur_holder_commitment_transaction_number, &self.secp_ctx);
4397                                         return Some(msgs::FundingLocked {
4398                                                 channel_id: self.channel_id,
4399                                                 next_per_commitment_point,
4400                                                 short_channel_id_alias: None,
4401                                         });
4402                                 }
4403                         } else {
4404                                 self.monitor_pending_funding_locked = true;
4405                         }
4406                 }
4407                 None
4408         }
4409
4410         /// When a transaction is confirmed, we check whether it is or spends the funding transaction
4411         /// In the first case, we store the confirmation height and calculating the short channel id.
4412         /// In the second, we simply return an Err indicating we need to be force-closed now.
4413         pub fn transactions_confirmed<L: Deref>(&mut self, block_hash: &BlockHash, height: u32,
4414                 txdata: &TransactionData, genesis_block_hash: BlockHash, node_pk: PublicKey, logger: &L)
4415         -> Result<(Option<msgs::FundingLocked>, Option<msgs::AnnouncementSignatures>), ClosureReason> where L::Target: Logger {
4416                 let non_shutdown_state = self.channel_state & (!MULTI_STATE_FLAGS);
4417                 if let Some(funding_txo) = self.get_funding_txo() {
4418                         for &(index_in_block, tx) in txdata.iter() {
4419                                 // If we haven't yet sent a funding_locked, but are in FundingSent (ignoring
4420                                 // whether they've sent a funding_locked or not), check if we should send one.
4421                                 if non_shutdown_state & !(ChannelState::TheirFundingLocked as u32) == ChannelState::FundingSent as u32 {
4422                                         if tx.txid() == funding_txo.txid {
4423                                                 let txo_idx = funding_txo.index as usize;
4424                                                 if txo_idx >= tx.output.len() || tx.output[txo_idx].script_pubkey != self.get_funding_redeemscript().to_v0_p2wsh() ||
4425                                                                 tx.output[txo_idx].value != self.channel_value_satoshis {
4426                                                         if self.is_outbound() {
4427                                                                 // If we generated the funding transaction and it doesn't match what it
4428                                                                 // should, the client is really broken and we should just panic and
4429                                                                 // tell them off. That said, because hash collisions happen with high
4430                                                                 // probability in fuzztarget mode, if we're fuzzing we just close the
4431                                                                 // channel and move on.
4432                                                                 #[cfg(not(feature = "fuzztarget"))]
4433                                                                 panic!("Client called ChannelManager::funding_transaction_generated with bogus transaction!");
4434                                                         }
4435                                                         self.update_time_counter += 1;
4436                                                         let err_reason = "funding tx had wrong script/value or output index";
4437                                                         return Err(ClosureReason::ProcessingError { err: err_reason.to_owned() });
4438                                                 } else {
4439                                                         if self.is_outbound() {
4440                                                                 for input in tx.input.iter() {
4441                                                                         if input.witness.is_empty() {
4442                                                                                 // We generated a malleable funding transaction, implying we've
4443                                                                                 // just exposed ourselves to funds loss to our counterparty.
4444                                                                                 #[cfg(not(feature = "fuzztarget"))]
4445                                                                                 panic!("Client called ChannelManager::funding_transaction_generated with bogus transaction!");
4446                                                                         }
4447                                                                 }
4448                                                         }
4449                                                         self.funding_tx_confirmation_height = height;
4450                                                         self.funding_tx_confirmed_in = Some(*block_hash);
4451                                                         self.short_channel_id = match scid_from_parts(height as u64, index_in_block as u64, txo_idx as u64) {
4452                                                                 Ok(scid) => Some(scid),
4453                                                                 Err(_) => panic!("Block was bogus - either height was > 16 million, had > 16 million transactions, or had > 65k outputs"),
4454                                                         }
4455                                                 }
4456                                         }
4457                                         // If we allow 1-conf funding, we may need to check for funding_locked here and
4458                                         // send it immediately instead of waiting for a best_block_updated call (which
4459                                         // may have already happened for this block).
4460                                         if let Some(funding_locked) = self.check_get_funding_locked(height) {
4461                                                 log_info!(logger, "Sending a funding_locked to our peer for channel {}", log_bytes!(self.channel_id));
4462                                                 let announcement_sigs = self.get_announcement_sigs(node_pk, genesis_block_hash, height, logger);
4463                                                 return Ok((Some(funding_locked), announcement_sigs));
4464                                         }
4465                                 }
4466                                 for inp in tx.input.iter() {
4467                                         if inp.previous_output == funding_txo.into_bitcoin_outpoint() {
4468                                                 log_info!(logger, "Detected channel-closing tx {} spending {}:{}, closing channel {}", tx.txid(), inp.previous_output.txid, inp.previous_output.vout, log_bytes!(self.channel_id()));
4469                                                 return Err(ClosureReason::CommitmentTxConfirmed);
4470                                         }
4471                                 }
4472                         }
4473                 }
4474                 Ok((None, None))
4475         }
4476
4477         /// When a new block is connected, we check the height of the block against outbound holding
4478         /// cell HTLCs in case we need to give up on them prematurely and time them out. Everything
4479         /// else (e.g. commitment transaction broadcasts, HTLC transaction broadcasting, etc) is
4480         /// handled by the ChannelMonitor.
4481         ///
4482         /// If we return Err, the channel may have been closed, at which point the standard
4483         /// requirements apply - no calls may be made except those explicitly stated to be allowed
4484         /// post-shutdown.
4485         ///
4486         /// May return some HTLCs (and their payment_hash) which have timed out and should be failed
4487         /// back.
4488         pub fn best_block_updated<L: Deref>(&mut self, height: u32, highest_header_time: u32, genesis_block_hash: BlockHash, node_pk: PublicKey, logger: &L)
4489         -> Result<(Option<msgs::FundingLocked>, Vec<(HTLCSource, PaymentHash)>, Option<msgs::AnnouncementSignatures>), ClosureReason> where L::Target: Logger {
4490                 self.do_best_block_updated(height, highest_header_time, Some((genesis_block_hash, node_pk)), logger)
4491         }
4492
4493         fn do_best_block_updated<L: Deref>(&mut self, height: u32, highest_header_time: u32, genesis_node_pk: Option<(BlockHash, PublicKey)>, logger: &L)
4494         -> Result<(Option<msgs::FundingLocked>, Vec<(HTLCSource, PaymentHash)>, Option<msgs::AnnouncementSignatures>), ClosureReason> where L::Target: Logger {
4495                 let mut timed_out_htlcs = Vec::new();
4496                 // This mirrors the check in ChannelManager::decode_update_add_htlc_onion, refusing to
4497                 // forward an HTLC when our counterparty should almost certainly just fail it for expiring
4498                 // ~now.
4499                 let unforwarded_htlc_cltv_limit = height + LATENCY_GRACE_PERIOD_BLOCKS;
4500                 self.holding_cell_htlc_updates.retain(|htlc_update| {
4501                         match htlc_update {
4502                                 &HTLCUpdateAwaitingACK::AddHTLC { ref payment_hash, ref source, ref cltv_expiry, .. } => {
4503                                         if *cltv_expiry <= unforwarded_htlc_cltv_limit {
4504                                                 timed_out_htlcs.push((source.clone(), payment_hash.clone()));
4505                                                 false
4506                                         } else { true }
4507                                 },
4508                                 _ => true
4509                         }
4510                 });
4511
4512                 self.update_time_counter = cmp::max(self.update_time_counter, highest_header_time);
4513
4514                 if let Some(funding_locked) = self.check_get_funding_locked(height) {
4515                         let announcement_sigs = if let Some((genesis_block_hash, node_pk)) = genesis_node_pk {
4516                                 self.get_announcement_sigs(node_pk, genesis_block_hash, height, logger)
4517                         } else { None };
4518                         log_info!(logger, "Sending a funding_locked to our peer for channel {}", log_bytes!(self.channel_id));
4519                         return Ok((Some(funding_locked), timed_out_htlcs, announcement_sigs));
4520                 }
4521
4522                 let non_shutdown_state = self.channel_state & (!MULTI_STATE_FLAGS);
4523                 if non_shutdown_state >= ChannelState::ChannelFunded as u32 ||
4524                    (non_shutdown_state & ChannelState::OurFundingLocked as u32) == ChannelState::OurFundingLocked as u32 {
4525                         let mut funding_tx_confirmations = height as i64 - self.funding_tx_confirmation_height as i64 + 1;
4526                         if self.funding_tx_confirmation_height == 0 {
4527                                 // Note that check_get_funding_locked may reset funding_tx_confirmation_height to
4528                                 // zero if it has been reorged out, however in either case, our state flags
4529                                 // indicate we've already sent a funding_locked
4530                                 funding_tx_confirmations = 0;
4531                         }
4532
4533                         // If we've sent funding_locked (or have both sent and received funding_locked), and
4534                         // the funding transaction's confirmation count has dipped below minimum_depth / 2,
4535                         // close the channel and hope we can get the latest state on chain (because presumably
4536                         // the funding transaction is at least still in the mempool of most nodes).
4537                         if funding_tx_confirmations < self.minimum_depth.unwrap() as i64 / 2 {
4538                                 let err_reason = format!("Funding transaction was un-confirmed. Locked at {} confs, now have {} confs.",
4539                                         self.minimum_depth.unwrap(), funding_tx_confirmations);
4540                                 return Err(ClosureReason::ProcessingError { err: err_reason });
4541                         }
4542                 } else if !self.is_outbound() && self.funding_tx_confirmed_in.is_none() &&
4543                                 height >= self.channel_creation_height + FUNDING_CONF_DEADLINE_BLOCKS {
4544                         log_info!(logger, "Closing channel {} due to funding timeout", log_bytes!(self.channel_id));
4545                         // If funding_tx_confirmed_in is unset, the channel must not be active
4546                         assert!(non_shutdown_state <= ChannelState::ChannelFunded as u32);
4547                         assert_eq!(non_shutdown_state & ChannelState::OurFundingLocked as u32, 0);
4548                         return Err(ClosureReason::FundingTimedOut);
4549                 }
4550
4551                 let announcement_sigs = if let Some((genesis_block_hash, node_pk)) = genesis_node_pk {
4552                         self.get_announcement_sigs(node_pk, genesis_block_hash, height, logger)
4553                 } else { None };
4554                 Ok((None, timed_out_htlcs, announcement_sigs))
4555         }
4556
4557         /// Indicates the funding transaction is no longer confirmed in the main chain. This may
4558         /// force-close the channel, but may also indicate a harmless reorganization of a block or two
4559         /// before the channel has reached funding_locked and we can just wait for more blocks.
4560         pub fn funding_transaction_unconfirmed<L: Deref>(&mut self, logger: &L) -> Result<(), ClosureReason> where L::Target: Logger {
4561                 if self.funding_tx_confirmation_height != 0 {
4562                         // We handle the funding disconnection by calling best_block_updated with a height one
4563                         // below where our funding was connected, implying a reorg back to conf_height - 1.
4564                         let reorg_height = self.funding_tx_confirmation_height - 1;
4565                         // We use the time field to bump the current time we set on channel updates if its
4566                         // larger. If we don't know that time has moved forward, we can just set it to the last
4567                         // time we saw and it will be ignored.
4568                         let best_time = self.update_time_counter;
4569                         match self.do_best_block_updated(reorg_height, best_time, None, logger) {
4570                                 Ok((funding_locked, timed_out_htlcs, announcement_sigs)) => {
4571                                         assert!(funding_locked.is_none(), "We can't generate a funding with 0 confirmations?");
4572                                         assert!(timed_out_htlcs.is_empty(), "We can't have accepted HTLCs with a timeout before our funding confirmation?");
4573                                         assert!(announcement_sigs.is_none(), "We can't generate an announcement_sigs with 0 confirmations?");
4574                                         Ok(())
4575                                 },
4576                                 Err(e) => Err(e)
4577                         }
4578                 } else {
4579                         // We never learned about the funding confirmation anyway, just ignore
4580                         Ok(())
4581                 }
4582         }
4583
4584         // Methods to get unprompted messages to send to the remote end (or where we already returned
4585         // something in the handler for the message that prompted this message):
4586
4587         pub fn get_open_channel(&self, chain_hash: BlockHash) -> msgs::OpenChannel {
4588                 if !self.is_outbound() {
4589                         panic!("Tried to open a channel for an inbound channel?");
4590                 }
4591                 if self.channel_state != ChannelState::OurInitSent as u32 {
4592                         panic!("Cannot generate an open_channel after we've moved forward");
4593                 }
4594
4595                 if self.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
4596                         panic!("Tried to send an open_channel for a channel that has already advanced");
4597                 }
4598
4599                 let first_per_commitment_point = self.holder_signer.get_per_commitment_point(self.cur_holder_commitment_transaction_number, &self.secp_ctx);
4600                 let keys = self.get_holder_pubkeys();
4601
4602                 msgs::OpenChannel {
4603                         chain_hash,
4604                         temporary_channel_id: self.channel_id,
4605                         funding_satoshis: self.channel_value_satoshis,
4606                         push_msat: self.channel_value_satoshis * 1000 - self.value_to_self_msat,
4607                         dust_limit_satoshis: self.holder_dust_limit_satoshis,
4608                         max_htlc_value_in_flight_msat: self.holder_max_htlc_value_in_flight_msat,
4609                         channel_reserve_satoshis: self.holder_selected_channel_reserve_satoshis,
4610                         htlc_minimum_msat: self.holder_htlc_minimum_msat,
4611                         feerate_per_kw: self.feerate_per_kw as u32,
4612                         to_self_delay: self.get_holder_selected_contest_delay(),
4613                         max_accepted_htlcs: OUR_MAX_HTLCS,
4614                         funding_pubkey: keys.funding_pubkey,
4615                         revocation_basepoint: keys.revocation_basepoint,
4616                         payment_point: keys.payment_point,
4617                         delayed_payment_basepoint: keys.delayed_payment_basepoint,
4618                         htlc_basepoint: keys.htlc_basepoint,
4619                         first_per_commitment_point,
4620                         channel_flags: if self.config.announced_channel {1} else {0},
4621                         shutdown_scriptpubkey: OptionalField::Present(match &self.shutdown_scriptpubkey {
4622                                 Some(script) => script.clone().into_inner(),
4623                                 None => Builder::new().into_script(),
4624                         }),
4625                         channel_type: Some(self.channel_type.clone()),
4626                 }
4627         }
4628
4629         pub fn get_accept_channel(&self) -> msgs::AcceptChannel {
4630                 if self.is_outbound() {
4631                         panic!("Tried to send accept_channel for an outbound channel?");
4632                 }
4633                 if self.channel_state != (ChannelState::OurInitSent as u32) | (ChannelState::TheirInitSent as u32) {
4634                         panic!("Tried to send accept_channel after channel had moved forward");
4635                 }
4636                 if self.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
4637                         panic!("Tried to send an accept_channel for a channel that has already advanced");
4638                 }
4639
4640                 let first_per_commitment_point = self.holder_signer.get_per_commitment_point(self.cur_holder_commitment_transaction_number, &self.secp_ctx);
4641                 let keys = self.get_holder_pubkeys();
4642
4643                 msgs::AcceptChannel {
4644                         temporary_channel_id: self.channel_id,
4645                         dust_limit_satoshis: self.holder_dust_limit_satoshis,
4646                         max_htlc_value_in_flight_msat: self.holder_max_htlc_value_in_flight_msat,
4647                         channel_reserve_satoshis: self.holder_selected_channel_reserve_satoshis,
4648                         htlc_minimum_msat: self.holder_htlc_minimum_msat,
4649                         minimum_depth: self.minimum_depth.unwrap(),
4650                         to_self_delay: self.get_holder_selected_contest_delay(),
4651                         max_accepted_htlcs: OUR_MAX_HTLCS,
4652                         funding_pubkey: keys.funding_pubkey,
4653                         revocation_basepoint: keys.revocation_basepoint,
4654                         payment_point: keys.payment_point,
4655                         delayed_payment_basepoint: keys.delayed_payment_basepoint,
4656                         htlc_basepoint: keys.htlc_basepoint,
4657                         first_per_commitment_point,
4658                         shutdown_scriptpubkey: OptionalField::Present(match &self.shutdown_scriptpubkey {
4659                                 Some(script) => script.clone().into_inner(),
4660                                 None => Builder::new().into_script(),
4661                         }),
4662                 }
4663         }
4664
4665         /// If an Err is returned, it is a ChannelError::Close (for get_outbound_funding_created)
4666         fn get_outbound_funding_created_signature<L: Deref>(&mut self, logger: &L) -> Result<Signature, ChannelError> where L::Target: Logger {
4667                 let counterparty_keys = self.build_remote_transaction_keys()?;
4668                 let counterparty_initial_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;
4669                 Ok(self.holder_signer.sign_counterparty_commitment(&counterparty_initial_commitment_tx, &self.secp_ctx)
4670                                 .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?.0)
4671         }
4672
4673         /// Updates channel state with knowledge of the funding transaction's txid/index, and generates
4674         /// a funding_created message for the remote peer.
4675         /// Panics if called at some time other than immediately after initial handshake, if called twice,
4676         /// or if called on an inbound channel.
4677         /// Note that channel_id changes during this call!
4678         /// Do NOT broadcast the funding transaction until after a successful funding_signed call!
4679         /// If an Err is returned, it is a ChannelError::Close.
4680         pub fn get_outbound_funding_created<L: Deref>(&mut self, funding_transaction: Transaction, funding_txo: OutPoint, logger: &L) -> Result<msgs::FundingCreated, ChannelError> where L::Target: Logger {
4681                 if !self.is_outbound() {
4682                         panic!("Tried to create outbound funding_created message on an inbound channel!");
4683                 }
4684                 if self.channel_state != (ChannelState::OurInitSent as u32 | ChannelState::TheirInitSent as u32) {
4685                         panic!("Tried to get a funding_created messsage at a time other than immediately after initial handshake completion (or tried to get funding_created twice)");
4686                 }
4687                 if self.commitment_secrets.get_min_seen_secret() != (1 << 48) ||
4688                                 self.cur_counterparty_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER ||
4689                                 self.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
4690                         panic!("Should not have advanced channel commitment tx numbers prior to funding_created");
4691                 }
4692
4693                 self.channel_transaction_parameters.funding_outpoint = Some(funding_txo);
4694                 self.holder_signer.ready_channel(&self.channel_transaction_parameters);
4695
4696                 let signature = match self.get_outbound_funding_created_signature(logger) {
4697                         Ok(res) => res,
4698                         Err(e) => {
4699                                 log_error!(logger, "Got bad signatures: {:?}!", e);
4700                                 self.channel_transaction_parameters.funding_outpoint = None;
4701                                 return Err(e);
4702                         }
4703                 };
4704
4705                 let temporary_channel_id = self.channel_id;
4706
4707                 // Now that we're past error-generating stuff, update our local state:
4708
4709                 self.channel_state = ChannelState::FundingCreated as u32;
4710                 self.channel_id = funding_txo.to_channel_id();
4711                 self.funding_transaction = Some(funding_transaction);
4712
4713                 Ok(msgs::FundingCreated {
4714                         temporary_channel_id,
4715                         funding_txid: funding_txo.txid,
4716                         funding_output_index: funding_txo.index,
4717                         signature
4718                 })
4719         }
4720
4721         /// Gets an UnsignedChannelAnnouncement for this channel. The channel must be publicly
4722         /// announceable and available for use (have exchanged FundingLocked messages in both
4723         /// directions). Should be used for both loose and in response to an AnnouncementSignatures
4724         /// message from the remote peer.
4725         ///
4726         /// Will only fail if we're not in a state where channel_announcement may be sent (including
4727         /// closing).
4728         ///
4729         /// Note that the "channel must be funded" requirement is stricter than BOLT 7 requires - see
4730         /// https://github.com/lightningnetwork/lightning-rfc/issues/468
4731         ///
4732         /// This will only return ChannelError::Ignore upon failure.
4733         fn get_channel_announcement(&self, node_id: PublicKey, chain_hash: BlockHash) -> Result<msgs::UnsignedChannelAnnouncement, ChannelError> {
4734                 if !self.config.announced_channel {
4735                         return Err(ChannelError::Ignore("Channel is not available for public announcements".to_owned()));
4736                 }
4737                 if !self.is_usable() {
4738                         return Err(ChannelError::Ignore("Cannot get a ChannelAnnouncement if the channel is not currently usable".to_owned()));
4739                 }
4740
4741                 let were_node_one = node_id.serialize()[..] < self.counterparty_node_id.serialize()[..];
4742
4743                 let msg = msgs::UnsignedChannelAnnouncement {
4744                         features: ChannelFeatures::known(),
4745                         chain_hash,
4746                         short_channel_id: self.get_short_channel_id().unwrap(),
4747                         node_id_1: if were_node_one { node_id } else { self.get_counterparty_node_id() },
4748                         node_id_2: if were_node_one { self.get_counterparty_node_id() } else { node_id },
4749                         bitcoin_key_1: if were_node_one { self.get_holder_pubkeys().funding_pubkey } else { self.counterparty_funding_pubkey().clone() },
4750                         bitcoin_key_2: if were_node_one { self.counterparty_funding_pubkey().clone() } else { self.get_holder_pubkeys().funding_pubkey },
4751                         excess_data: Vec::new(),
4752                 };
4753
4754                 Ok(msg)
4755         }
4756
4757         fn get_announcement_sigs<L: Deref>(&mut self, node_pk: PublicKey, genesis_block_hash: BlockHash, best_block_height: u32, logger: &L)
4758         -> Option<msgs::AnnouncementSignatures> where L::Target: Logger {
4759                 if self.funding_tx_confirmation_height == 0 || self.funding_tx_confirmation_height + 5 > best_block_height {
4760                         return None;
4761                 }
4762
4763                 if !self.is_usable() {
4764                         return None;
4765                 }
4766
4767                 if self.channel_state & ChannelState::PeerDisconnected as u32 != 0 {
4768                         log_trace!(logger, "Cannot create an announcement_signatures as our peer is disconnected");
4769                         return None;
4770                 }
4771
4772                 if self.announcement_sigs_state != AnnouncementSigsState::NotSent {
4773                         return None;
4774                 }
4775
4776                 log_trace!(logger, "Creating an announcement_signatures message for channel {}", log_bytes!(self.channel_id()));
4777                 let announcement = match self.get_channel_announcement(node_pk, genesis_block_hash) {
4778                         Ok(a) => a,
4779                         Err(_) => {
4780                                 log_trace!(logger, "Cannot create an announcement_signatures as channel is not public.");
4781                                 return None;
4782                         }
4783                 };
4784                 let (our_node_sig, our_bitcoin_sig) = match self.holder_signer.sign_channel_announcement(&announcement, &self.secp_ctx) {
4785                         Err(_) => {
4786                                 log_error!(logger, "Signer rejected channel_announcement signing. Channel will not be announced!");
4787                                 return None;
4788                         },
4789                         Ok(v) => v
4790                 };
4791                 self.announcement_sigs_state = AnnouncementSigsState::MessageSent;
4792
4793                 Some(msgs::AnnouncementSignatures {
4794                         channel_id: self.channel_id(),
4795                         short_channel_id: self.get_short_channel_id().unwrap(),
4796                         node_signature: our_node_sig,
4797                         bitcoin_signature: our_bitcoin_sig,
4798                 })
4799         }
4800
4801         /// Signs the given channel announcement, returning a ChannelError::Ignore if no keys are
4802         /// available.
4803         fn sign_channel_announcement(&self, our_node_id: PublicKey, announcement: msgs::UnsignedChannelAnnouncement) -> Result<msgs::ChannelAnnouncement, ChannelError> {
4804                 if let Some((their_node_sig, their_bitcoin_sig)) = self.announcement_sigs {
4805                         let were_node_one = announcement.node_id_1 == our_node_id;
4806
4807                         let (our_node_sig, our_bitcoin_sig) = self.holder_signer.sign_channel_announcement(&announcement, &self.secp_ctx)
4808                                 .map_err(|_| ChannelError::Ignore("Signer rejected channel_announcement".to_owned()))?;
4809                         Ok(msgs::ChannelAnnouncement {
4810                                 node_signature_1: if were_node_one { our_node_sig } else { their_node_sig },
4811                                 node_signature_2: if were_node_one { their_node_sig } else { our_node_sig },
4812                                 bitcoin_signature_1: if were_node_one { our_bitcoin_sig } else { their_bitcoin_sig },
4813                                 bitcoin_signature_2: if were_node_one { their_bitcoin_sig } else { our_bitcoin_sig },
4814                                 contents: announcement,
4815                         })
4816                 } else {
4817                         Err(ChannelError::Ignore("Attempted to sign channel announcement before we'd received announcement_signatures".to_string()))
4818                 }
4819         }
4820
4821         /// Processes an incoming announcement_signatures message, providing a fully-signed
4822         /// channel_announcement message which we can broadcast and storing our counterparty's
4823         /// signatures for later reconstruction/rebroadcast of the channel_announcement.
4824         pub fn announcement_signatures(&mut self, our_node_id: PublicKey, chain_hash: BlockHash, best_block_height: u32, msg: &msgs::AnnouncementSignatures) -> Result<msgs::ChannelAnnouncement, ChannelError> {
4825                 let announcement = self.get_channel_announcement(our_node_id.clone(), chain_hash)?;
4826
4827                 let msghash = hash_to_message!(&Sha256d::hash(&announcement.encode()[..])[..]);
4828
4829                 if self.secp_ctx.verify(&msghash, &msg.node_signature, &self.get_counterparty_node_id()).is_err() {
4830                         return Err(ChannelError::Close(format!(
4831                                 "Bad announcement_signatures. Failed to verify node_signature. UnsignedChannelAnnouncement used for verification is {:?}. their_node_key is {:?}",
4832                                  &announcement, self.get_counterparty_node_id())));
4833                 }
4834                 if self.secp_ctx.verify(&msghash, &msg.bitcoin_signature, self.counterparty_funding_pubkey()).is_err() {
4835                         return Err(ChannelError::Close(format!(
4836                                 "Bad announcement_signatures. Failed to verify bitcoin_signature. UnsignedChannelAnnouncement used for verification is {:?}. their_bitcoin_key is ({:?})",
4837                                 &announcement, self.counterparty_funding_pubkey())));
4838                 }
4839
4840                 self.announcement_sigs = Some((msg.node_signature, msg.bitcoin_signature));
4841                 if self.funding_tx_confirmation_height == 0 || self.funding_tx_confirmation_height + 5 > best_block_height {
4842                         return Err(ChannelError::Ignore(
4843                                 "Got announcement_signatures prior to the required six confirmations - we may not have received a block yet that our peer has".to_owned()));
4844                 }
4845
4846                 self.sign_channel_announcement(our_node_id, announcement)
4847         }
4848
4849         /// Gets a signed channel_announcement for this channel, if we previously received an
4850         /// announcement_signatures from our counterparty.
4851         pub fn get_signed_channel_announcement(&self, our_node_id: PublicKey, chain_hash: BlockHash, best_block_height: u32) -> Option<msgs::ChannelAnnouncement> {
4852                 if self.funding_tx_confirmation_height == 0 || self.funding_tx_confirmation_height + 5 > best_block_height {
4853                         return None;
4854                 }
4855                 let announcement = match self.get_channel_announcement(our_node_id.clone(), chain_hash) {
4856                         Ok(res) => res,
4857                         Err(_) => return None,
4858                 };
4859                 match self.sign_channel_announcement(our_node_id, announcement) {
4860                         Ok(res) => Some(res),
4861                         Err(_) => None,
4862                 }
4863         }
4864
4865         /// May panic if called on a channel that wasn't immediately-previously
4866         /// self.remove_uncommitted_htlcs_and_mark_paused()'d
4867         pub fn get_channel_reestablish<L: Deref>(&self, logger: &L) -> msgs::ChannelReestablish where L::Target: Logger {
4868                 assert_eq!(self.channel_state & ChannelState::PeerDisconnected as u32, ChannelState::PeerDisconnected as u32);
4869                 assert_ne!(self.cur_counterparty_commitment_transaction_number, INITIAL_COMMITMENT_NUMBER);
4870                 // Prior to static_remotekey, my_current_per_commitment_point was critical to claiming
4871                 // current to_remote balances. However, it no longer has any use, and thus is now simply
4872                 // set to a dummy (but valid, as required by the spec) public key.
4873                 // fuzztarget mode marks a subset of pubkeys as invalid so that we can hit "invalid pubkey"
4874                 // branches, but we unwrap it below, so we arbitrarily select a dummy pubkey which is both
4875                 // valid, and valid in fuzztarget mode's arbitrary validity criteria:
4876                 let mut pk = [2; 33]; pk[1] = 0xff;
4877                 let dummy_pubkey = PublicKey::from_slice(&pk).unwrap();
4878                 let data_loss_protect = if self.cur_counterparty_commitment_transaction_number + 1 < INITIAL_COMMITMENT_NUMBER {
4879                         let remote_last_secret = self.commitment_secrets.get_secret(self.cur_counterparty_commitment_transaction_number + 2).unwrap();
4880                         log_trace!(logger, "Enough info to generate a Data Loss Protect with per_commitment_secret {} for channel {}", log_bytes!(remote_last_secret), log_bytes!(self.channel_id()));
4881                         OptionalField::Present(DataLossProtect {
4882                                 your_last_per_commitment_secret: remote_last_secret,
4883                                 my_current_per_commitment_point: dummy_pubkey
4884                         })
4885                 } else {
4886                         log_info!(logger, "Sending a data_loss_protect with no previous remote per_commitment_secret for channel {}", log_bytes!(self.channel_id()));
4887                         OptionalField::Present(DataLossProtect {
4888                                 your_last_per_commitment_secret: [0;32],
4889                                 my_current_per_commitment_point: dummy_pubkey,
4890                         })
4891                 };
4892                 msgs::ChannelReestablish {
4893                         channel_id: self.channel_id(),
4894                         // The protocol has two different commitment number concepts - the "commitment
4895                         // transaction number", which starts from 0 and counts up, and the "revocation key
4896                         // index" which starts at INITIAL_COMMITMENT_NUMBER and counts down. We track
4897                         // commitment transaction numbers by the index which will be used to reveal the
4898                         // revocation key for that commitment transaction, which means we have to convert them
4899                         // to protocol-level commitment numbers here...
4900
4901                         // next_local_commitment_number is the next commitment_signed number we expect to
4902                         // receive (indicating if they need to resend one that we missed).
4903                         next_local_commitment_number: INITIAL_COMMITMENT_NUMBER - self.cur_holder_commitment_transaction_number,
4904                         // We have to set next_remote_commitment_number to the next revoke_and_ack we expect to
4905                         // receive, however we track it by the next commitment number for a remote transaction
4906                         // (which is one further, as they always revoke previous commitment transaction, not
4907                         // the one we send) so we have to decrement by 1. Note that if
4908                         // cur_counterparty_commitment_transaction_number is INITIAL_COMMITMENT_NUMBER we will have
4909                         // dropped this channel on disconnect as it hasn't yet reached FundingSent so we can't
4910                         // overflow here.
4911                         next_remote_commitment_number: INITIAL_COMMITMENT_NUMBER - self.cur_counterparty_commitment_transaction_number - 1,
4912                         data_loss_protect,
4913                 }
4914         }
4915
4916
4917         // Send stuff to our remote peers:
4918
4919         /// Adds a pending outbound HTLC to this channel, note that you probably want
4920         /// send_htlc_and_commit instead cause you'll want both messages at once.
4921         ///
4922         /// This returns an optional UpdateAddHTLC as we may be in a state where we cannot add HTLCs on
4923         /// the wire:
4924         /// * In cases where we're waiting on the remote peer to send us a revoke_and_ack, we
4925         ///   wouldn't be able to determine what they actually ACK'ed if we have two sets of updates
4926         ///   awaiting ACK.
4927         /// * In cases where we're marked MonitorUpdateFailed, we cannot commit to a new state as we
4928         ///   may not yet have sent the previous commitment update messages and will need to regenerate
4929         ///   them.
4930         ///
4931         /// You MUST call send_commitment prior to calling any other methods on this Channel!
4932         ///
4933         /// If an Err is returned, it's a ChannelError::Ignore!
4934         pub fn send_htlc<L: Deref>(&mut self, amount_msat: u64, payment_hash: PaymentHash, cltv_expiry: u32, source: HTLCSource, onion_routing_packet: msgs::OnionPacket, logger: &L) -> Result<Option<msgs::UpdateAddHTLC>, ChannelError> where L::Target: Logger {
4935                 if (self.channel_state & (ChannelState::ChannelFunded as u32 | BOTH_SIDES_SHUTDOWN_MASK)) != (ChannelState::ChannelFunded as u32) {
4936                         return Err(ChannelError::Ignore("Cannot send HTLC until channel is fully established and we haven't started shutting down".to_owned()));
4937                 }
4938                 let channel_total_msat = self.channel_value_satoshis * 1000;
4939                 if amount_msat > channel_total_msat {
4940                         return Err(ChannelError::Ignore(format!("Cannot send amount {}, because it is more than the total value of the channel {}", amount_msat, channel_total_msat)));
4941                 }
4942
4943                 if amount_msat == 0 {
4944                         return Err(ChannelError::Ignore("Cannot send 0-msat HTLC".to_owned()));
4945                 }
4946
4947                 if amount_msat < self.counterparty_htlc_minimum_msat {
4948                         return Err(ChannelError::Ignore(format!("Cannot send less than their minimum HTLC value ({})", self.counterparty_htlc_minimum_msat)));
4949                 }
4950
4951                 if (self.channel_state & (ChannelState::PeerDisconnected as u32)) != 0 {
4952                         // Note that this should never really happen, if we're !is_live() on receipt of an
4953                         // incoming HTLC for relay will result in us rejecting the HTLC and we won't allow
4954                         // the user to send directly into a !is_live() channel. However, if we
4955                         // disconnected during the time the previous hop was doing the commitment dance we may
4956                         // end up getting here after the forwarding delay. In any case, returning an
4957                         // IgnoreError will get ChannelManager to do the right thing and fail backwards now.
4958                         return Err(ChannelError::Ignore("Cannot send an HTLC while disconnected from channel counterparty".to_owned()));
4959                 }
4960
4961                 let inbound_stats = self.get_inbound_pending_htlc_stats(None);
4962                 let outbound_stats = self.get_outbound_pending_htlc_stats(None);
4963                 if outbound_stats.pending_htlcs + 1 > self.counterparty_max_accepted_htlcs as u32 {
4964                         return Err(ChannelError::Ignore(format!("Cannot push more than their max accepted HTLCs ({})", self.counterparty_max_accepted_htlcs)));
4965                 }
4966                 // Check their_max_htlc_value_in_flight_msat
4967                 if outbound_stats.pending_htlcs_value_msat + amount_msat > self.counterparty_max_htlc_value_in_flight_msat {
4968                         return Err(ChannelError::Ignore(format!("Cannot send value that would put us over the max HTLC value in flight our peer will accept ({})", self.counterparty_max_htlc_value_in_flight_msat)));
4969                 }
4970
4971                 let keys = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number)?;
4972                 let commitment_stats = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, true, logger);
4973                 if !self.is_outbound() {
4974                         // Check that we won't violate the remote channel reserve by adding this HTLC.
4975                         let htlc_candidate = HTLCCandidate::new(amount_msat, HTLCInitiator::LocalOffered);
4976                         let counterparty_commit_tx_fee_msat = self.next_remote_commit_tx_fee_msat(htlc_candidate, None);
4977                         let holder_selected_chan_reserve_msat = self.holder_selected_channel_reserve_satoshis * 1000;
4978                         if commitment_stats.remote_balance_msat < counterparty_commit_tx_fee_msat + holder_selected_chan_reserve_msat {
4979                                 return Err(ChannelError::Ignore("Cannot send value that would put counterparty balance under holder-announced channel reserve value".to_owned()));
4980                         }
4981                 }
4982
4983                 let exposure_dust_limit_success_sats = (self.get_dust_buffer_feerate(None) as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000) + self.counterparty_dust_limit_satoshis;
4984                 if amount_msat / 1000 < exposure_dust_limit_success_sats {
4985                         let on_counterparty_dust_htlc_exposure_msat = inbound_stats.on_counterparty_tx_dust_exposure_msat + outbound_stats.on_counterparty_tx_dust_exposure_msat + amount_msat;
4986                         if on_counterparty_dust_htlc_exposure_msat > self.get_max_dust_htlc_exposure_msat() {
4987                                 return Err(ChannelError::Ignore(format!("Cannot send value that would put our exposure to dust HTLCs at {} over the limit {} on counterparty commitment tx",
4988                                         on_counterparty_dust_htlc_exposure_msat, self.get_max_dust_htlc_exposure_msat())));
4989                         }
4990                 }
4991
4992                 let exposure_dust_limit_timeout_sats = (self.get_dust_buffer_feerate(None) as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000) + self.holder_dust_limit_satoshis;
4993                 if amount_msat / 1000 <  exposure_dust_limit_timeout_sats {
4994                         let on_holder_dust_htlc_exposure_msat = inbound_stats.on_holder_tx_dust_exposure_msat + outbound_stats.on_holder_tx_dust_exposure_msat + amount_msat;
4995                         if on_holder_dust_htlc_exposure_msat > self.get_max_dust_htlc_exposure_msat() {
4996                                 return Err(ChannelError::Ignore(format!("Cannot send value that would put our exposure to dust HTLCs at {} over the limit {} on holder commitment tx",
4997                                         on_holder_dust_htlc_exposure_msat, self.get_max_dust_htlc_exposure_msat())));
4998                         }
4999                 }
5000
5001                 let holder_balance_msat = commitment_stats.local_balance_msat - outbound_stats.holding_cell_msat;
5002                 if holder_balance_msat < amount_msat {
5003                         return Err(ChannelError::Ignore(format!("Cannot send value that would overdraw remaining funds. Amount: {}, pending value to self {}", amount_msat, holder_balance_msat)));
5004                 }
5005
5006                 // `2 *` and extra HTLC are for the fee spike buffer.
5007                 let commit_tx_fee_msat = if self.is_outbound() {
5008                         let htlc_candidate = HTLCCandidate::new(amount_msat, HTLCInitiator::LocalOffered);
5009                         FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE * self.next_local_commit_tx_fee_msat(htlc_candidate, Some(()))
5010                 } else { 0 };
5011                 if holder_balance_msat - amount_msat < commit_tx_fee_msat {
5012                         return Err(ChannelError::Ignore(format!("Cannot send value that would not leave enough to pay for fees. Pending value to self: {}. local_commit_tx_fee {}", holder_balance_msat, commit_tx_fee_msat)));
5013                 }
5014
5015                 // Check self.counterparty_selected_channel_reserve_satoshis (the amount we must keep as
5016                 // reserve for the remote to have something to claim if we misbehave)
5017                 let chan_reserve_msat = self.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000;
5018                 if holder_balance_msat - amount_msat - commit_tx_fee_msat < chan_reserve_msat {
5019                         return Err(ChannelError::Ignore(format!("Cannot send value that would put our balance under counterparty-announced channel reserve value ({})", chan_reserve_msat)));
5020                 }
5021
5022                 // Now update local state:
5023                 if (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::MonitorUpdateFailed as u32)) != 0 {
5024                         self.holding_cell_htlc_updates.push(HTLCUpdateAwaitingACK::AddHTLC {
5025                                 amount_msat,
5026                                 payment_hash,
5027                                 cltv_expiry,
5028                                 source,
5029                                 onion_routing_packet,
5030                         });
5031                         return Ok(None);
5032                 }
5033
5034                 self.pending_outbound_htlcs.push(OutboundHTLCOutput {
5035                         htlc_id: self.next_holder_htlc_id,
5036                         amount_msat,
5037                         payment_hash: payment_hash.clone(),
5038                         cltv_expiry,
5039                         state: OutboundHTLCState::LocalAnnounced(Box::new(onion_routing_packet.clone())),
5040                         source,
5041                 });
5042
5043                 let res = msgs::UpdateAddHTLC {
5044                         channel_id: self.channel_id,
5045                         htlc_id: self.next_holder_htlc_id,
5046                         amount_msat,
5047                         payment_hash,
5048                         cltv_expiry,
5049                         onion_routing_packet,
5050                 };
5051                 self.next_holder_htlc_id += 1;
5052
5053                 Ok(Some(res))
5054         }
5055
5056         /// Creates a signed commitment transaction to send to the remote peer.
5057         /// Always returns a ChannelError::Close if an immediately-preceding (read: the
5058         /// last call to this Channel) send_htlc returned Ok(Some(_)) and there is an Err.
5059         /// May panic if called except immediately after a successful, Ok(Some(_))-returning send_htlc.
5060         pub fn send_commitment<L: Deref>(&mut self, logger: &L) -> Result<(msgs::CommitmentSigned, ChannelMonitorUpdate), ChannelError> where L::Target: Logger {
5061                 if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
5062                         panic!("Cannot create commitment tx until channel is fully established");
5063                 }
5064                 if (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32)) == (ChannelState::AwaitingRemoteRevoke as u32) {
5065                         panic!("Cannot create commitment tx until remote revokes their previous commitment");
5066                 }
5067                 if (self.channel_state & (ChannelState::PeerDisconnected as u32)) == (ChannelState::PeerDisconnected as u32) {
5068                         panic!("Cannot create commitment tx while disconnected, as send_htlc will have returned an Err so a send_commitment precondition has been violated");
5069                 }
5070                 if (self.channel_state & (ChannelState::MonitorUpdateFailed as u32)) == (ChannelState::MonitorUpdateFailed as u32) {
5071                         panic!("Cannot create commitment tx while awaiting monitor update unfreeze, as send_htlc will have returned an Err so a send_commitment precondition has been violated");
5072                 }
5073                 let mut have_updates = self.is_outbound() && self.pending_update_fee.is_some();
5074                 for htlc in self.pending_outbound_htlcs.iter() {
5075                         if let OutboundHTLCState::LocalAnnounced(_) = htlc.state {
5076                                 have_updates = true;
5077                         }
5078                         if have_updates { break; }
5079                 }
5080                 for htlc in self.pending_inbound_htlcs.iter() {
5081                         if let InboundHTLCState::LocalRemoved(_) = htlc.state {
5082                                 have_updates = true;
5083                         }
5084                         if have_updates { break; }
5085                 }
5086                 if !have_updates {
5087                         panic!("Cannot create commitment tx until we have some updates to send");
5088                 }
5089                 self.send_commitment_no_status_check(logger)
5090         }
5091         /// Only fails in case of bad keys
5092         fn send_commitment_no_status_check<L: Deref>(&mut self, logger: &L) -> Result<(msgs::CommitmentSigned, ChannelMonitorUpdate), ChannelError> where L::Target: Logger {
5093                 log_trace!(logger, "Updating HTLC state for a newly-sent commitment_signed...");
5094                 // We can upgrade the status of some HTLCs that are waiting on a commitment, even if we
5095                 // fail to generate this, we still are at least at a position where upgrading their status
5096                 // is acceptable.
5097                 for htlc in self.pending_inbound_htlcs.iter_mut() {
5098                         let new_state = if let &InboundHTLCState::AwaitingRemoteRevokeToAnnounce(ref forward_info) = &htlc.state {
5099                                 Some(InboundHTLCState::AwaitingAnnouncedRemoteRevoke(forward_info.clone()))
5100                         } else { None };
5101                         if let Some(state) = new_state {
5102                                 log_trace!(logger, " ...promoting inbound AwaitingRemoteRevokeToAnnounce {} to AwaitingAnnouncedRemoteRevoke", log_bytes!(htlc.payment_hash.0));
5103                                 htlc.state = state;
5104                         }
5105                 }
5106                 for htlc in self.pending_outbound_htlcs.iter_mut() {
5107                         if let Some(fail_reason) = if let &mut OutboundHTLCState::AwaitingRemoteRevokeToRemove(ref mut fail_reason) = &mut htlc.state {
5108                                 Some(fail_reason.take())
5109                         } else { None } {
5110                                 log_trace!(logger, " ...promoting outbound AwaitingRemoteRevokeToRemove {} to AwaitingRemovedRemoteRevoke", log_bytes!(htlc.payment_hash.0));
5111                                 htlc.state = OutboundHTLCState::AwaitingRemovedRemoteRevoke(fail_reason);
5112                         }
5113                 }
5114                 if let Some((feerate, update_state)) = self.pending_update_fee {
5115                         if update_state == FeeUpdateState::AwaitingRemoteRevokeToAnnounce {
5116                                 debug_assert!(!self.is_outbound());
5117                                 log_trace!(logger, " ...promoting inbound AwaitingRemoteRevokeToAnnounce fee update {} to Committed", feerate);
5118                                 self.feerate_per_kw = feerate;
5119                                 self.pending_update_fee = None;
5120                         }
5121                 }
5122                 self.resend_order = RAACommitmentOrder::RevokeAndACKFirst;
5123
5124                 let (res, counterparty_commitment_txid, htlcs) = match self.send_commitment_no_state_update(logger) {
5125                         Ok((res, (counterparty_commitment_tx, mut htlcs))) => {
5126                                 // Update state now that we've passed all the can-fail calls...
5127                                 let htlcs_no_ref: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)> =
5128                                         htlcs.drain(..).map(|(htlc, htlc_source)| (htlc, htlc_source.map(|source_ref| Box::new(source_ref.clone())))).collect();
5129                                 (res, counterparty_commitment_tx, htlcs_no_ref)
5130                         },
5131                         Err(e) => return Err(e),
5132                 };
5133
5134                 if self.announcement_sigs_state == AnnouncementSigsState::MessageSent {
5135                         self.announcement_sigs_state = AnnouncementSigsState::Committed;
5136                 }
5137
5138                 self.latest_monitor_update_id += 1;
5139                 let monitor_update = ChannelMonitorUpdate {
5140                         update_id: self.latest_monitor_update_id,
5141                         updates: vec![ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo {
5142                                 commitment_txid: counterparty_commitment_txid,
5143                                 htlc_outputs: htlcs.clone(),
5144                                 commitment_number: self.cur_counterparty_commitment_transaction_number,
5145                                 their_revocation_point: self.counterparty_cur_commitment_point.unwrap()
5146                         }]
5147                 };
5148                 self.channel_state |= ChannelState::AwaitingRemoteRevoke as u32;
5149                 Ok((res, monitor_update))
5150         }
5151
5152         /// Only fails in case of bad keys. Used for channel_reestablish commitment_signed generation
5153         /// when we shouldn't change HTLC/channel state.
5154         fn send_commitment_no_state_update<L: Deref>(&self, logger: &L) -> Result<(msgs::CommitmentSigned, (Txid, Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)>)), ChannelError> where L::Target: Logger {
5155                 let counterparty_keys = self.build_remote_transaction_keys()?;
5156                 let commitment_stats = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, true, logger);
5157                 let counterparty_commitment_txid = commitment_stats.tx.trust().txid();
5158                 let (signature, htlc_signatures);
5159
5160                 #[cfg(any(test, feature = "fuzztarget"))]
5161                 {
5162                         if !self.is_outbound() {
5163                                 let projected_commit_tx_info = self.next_remote_commitment_tx_fee_info_cached.lock().unwrap().take();
5164                                 *self.next_local_commitment_tx_fee_info_cached.lock().unwrap() = None;
5165                                 if let Some(info) = projected_commit_tx_info {
5166                                         let total_pending_htlcs = self.pending_inbound_htlcs.len() + self.pending_outbound_htlcs.len();
5167                                         if info.total_pending_htlcs == total_pending_htlcs
5168                                                 && info.next_holder_htlc_id == self.next_holder_htlc_id
5169                                                 && info.next_counterparty_htlc_id == self.next_counterparty_htlc_id
5170                                                 && info.feerate == self.feerate_per_kw {
5171                                                         let actual_fee = Self::commit_tx_fee_msat(self.feerate_per_kw, commitment_stats.num_nondust_htlcs);
5172                                                         assert_eq!(actual_fee, info.fee);
5173                                                 }
5174                                 }
5175                         }
5176                 }
5177
5178                 {
5179                         let mut htlcs = Vec::with_capacity(commitment_stats.htlcs_included.len());
5180                         for &(ref htlc, _) in commitment_stats.htlcs_included.iter() {
5181                                 htlcs.push(htlc);
5182                         }
5183
5184                         let res = self.holder_signer.sign_counterparty_commitment(&commitment_stats.tx, &self.secp_ctx)
5185                                 .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?;
5186                         signature = res.0;
5187                         htlc_signatures = res.1;
5188
5189                         log_trace!(logger, "Signed remote commitment tx {} (txid {}) with redeemscript {} -> {} in channel {}",
5190                                 encode::serialize_hex(&commitment_stats.tx.trust().built_transaction().transaction),
5191                                 &counterparty_commitment_txid, encode::serialize_hex(&self.get_funding_redeemscript()),
5192                                 log_bytes!(signature.serialize_compact()[..]), log_bytes!(self.channel_id()));
5193
5194                         for (ref htlc_sig, ref htlc) in htlc_signatures.iter().zip(htlcs) {
5195                                 log_trace!(logger, "Signed remote HTLC tx {} with redeemscript {} with pubkey {} -> {} in channel {}",
5196                                         encode::serialize_hex(&chan_utils::build_htlc_transaction(&counterparty_commitment_txid, commitment_stats.feerate_per_kw, self.get_holder_selected_contest_delay(), htlc, self.opt_anchors(), &counterparty_keys.broadcaster_delayed_payment_key, &counterparty_keys.revocation_key)),
5197                                         encode::serialize_hex(&chan_utils::get_htlc_redeemscript(&htlc, self.opt_anchors(), &counterparty_keys)),
5198                                         log_bytes!(counterparty_keys.broadcaster_htlc_key.serialize()),
5199                                         log_bytes!(htlc_sig.serialize_compact()[..]), log_bytes!(self.channel_id()));
5200                         }
5201                 }
5202
5203                 Ok((msgs::CommitmentSigned {
5204                         channel_id: self.channel_id,
5205                         signature,
5206                         htlc_signatures,
5207                 }, (counterparty_commitment_txid, commitment_stats.htlcs_included)))
5208         }
5209
5210         /// Adds a pending outbound HTLC to this channel, and creates a signed commitment transaction
5211         /// to send to the remote peer in one go.
5212         /// Shorthand for calling send_htlc() followed by send_commitment(), see docs on those for
5213         /// more info.
5214         pub fn send_htlc_and_commit<L: Deref>(&mut self, amount_msat: u64, payment_hash: PaymentHash, cltv_expiry: u32, source: HTLCSource, onion_routing_packet: msgs::OnionPacket, logger: &L) -> Result<Option<(msgs::UpdateAddHTLC, msgs::CommitmentSigned, ChannelMonitorUpdate)>, ChannelError> where L::Target: Logger {
5215                 match self.send_htlc(amount_msat, payment_hash, cltv_expiry, source, onion_routing_packet, logger)? {
5216                         Some(update_add_htlc) => {
5217                                 let (commitment_signed, monitor_update) = self.send_commitment_no_status_check(logger)?;
5218                                 Ok(Some((update_add_htlc, commitment_signed, monitor_update)))
5219                         },
5220                         None => Ok(None)
5221                 }
5222         }
5223
5224         /// Get forwarding information for the counterparty.
5225         pub fn counterparty_forwarding_info(&self) -> Option<CounterpartyForwardingInfo> {
5226                 self.counterparty_forwarding_info.clone()
5227         }
5228
5229         pub fn channel_update(&mut self, msg: &msgs::ChannelUpdate) -> Result<(), ChannelError> {
5230                 if msg.contents.htlc_minimum_msat >= self.channel_value_satoshis * 1000 {
5231                         return Err(ChannelError::Close("Minimum htlc value is greater than channel value".to_string()));
5232                 }
5233                 self.counterparty_forwarding_info = Some(CounterpartyForwardingInfo {
5234                         fee_base_msat: msg.contents.fee_base_msat,
5235                         fee_proportional_millionths: msg.contents.fee_proportional_millionths,
5236                         cltv_expiry_delta: msg.contents.cltv_expiry_delta
5237                 });
5238
5239                 Ok(())
5240         }
5241
5242         /// Begins the shutdown process, getting a message for the remote peer and returning all
5243         /// holding cell HTLCs for payment failure.
5244         pub fn get_shutdown<K: Deref>(&mut self, keys_provider: &K, their_features: &InitFeatures, target_feerate_sats_per_kw: Option<u32>)
5245         -> Result<(msgs::Shutdown, Option<ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>), APIError>
5246         where K::Target: KeysInterface<Signer = Signer> {
5247                 for htlc in self.pending_outbound_htlcs.iter() {
5248                         if let OutboundHTLCState::LocalAnnounced(_) = htlc.state {
5249                                 return Err(APIError::APIMisuseError{err: "Cannot begin shutdown with pending HTLCs. Process pending events first".to_owned()});
5250                         }
5251                 }
5252                 if self.channel_state & BOTH_SIDES_SHUTDOWN_MASK != 0 {
5253                         if (self.channel_state & ChannelState::LocalShutdownSent as u32) == ChannelState::LocalShutdownSent as u32 {
5254                                 return Err(APIError::APIMisuseError{err: "Shutdown already in progress".to_owned()});
5255                         }
5256                         else if (self.channel_state & ChannelState::RemoteShutdownSent as u32) == ChannelState::RemoteShutdownSent as u32 {
5257                                 return Err(APIError::ChannelUnavailable{err: "Shutdown already in progress by remote".to_owned()});
5258                         }
5259                 }
5260                 assert_eq!(self.channel_state & ChannelState::ShutdownComplete as u32, 0);
5261                 if self.channel_state & (ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateFailed as u32) != 0 {
5262                         return Err(APIError::ChannelUnavailable{err: "Cannot begin shutdown while peer is disconnected or we're waiting on a monitor update, maybe force-close instead?".to_owned()});
5263                 }
5264
5265                 let update_shutdown_script = match self.shutdown_scriptpubkey {
5266                         Some(_) => false,
5267                         None => {
5268                                 let shutdown_scriptpubkey = keys_provider.get_shutdown_scriptpubkey();
5269                                 if !shutdown_scriptpubkey.is_compatible(their_features) {
5270                                         return Err(APIError::IncompatibleShutdownScript { script: shutdown_scriptpubkey.clone() });
5271                                 }
5272                                 self.shutdown_scriptpubkey = Some(shutdown_scriptpubkey);
5273                                 true
5274                         },
5275                 };
5276
5277                 // From here on out, we may not fail!
5278                 self.target_closing_feerate_sats_per_kw = target_feerate_sats_per_kw;
5279                 if self.channel_state < ChannelState::FundingSent as u32 {
5280                         self.channel_state = ChannelState::ShutdownComplete as u32;
5281                 } else {
5282                         self.channel_state |= ChannelState::LocalShutdownSent as u32;
5283                 }
5284                 self.update_time_counter += 1;
5285
5286                 let monitor_update = if update_shutdown_script {
5287                         self.latest_monitor_update_id += 1;
5288                         Some(ChannelMonitorUpdate {
5289                                 update_id: self.latest_monitor_update_id,
5290                                 updates: vec![ChannelMonitorUpdateStep::ShutdownScript {
5291                                         scriptpubkey: self.get_closing_scriptpubkey(),
5292                                 }],
5293                         })
5294                 } else { None };
5295                 let shutdown = msgs::Shutdown {
5296                         channel_id: self.channel_id,
5297                         scriptpubkey: self.get_closing_scriptpubkey(),
5298                 };
5299
5300                 // Go ahead and drop holding cell updates as we'd rather fail payments than wait to send
5301                 // our shutdown until we've committed all of the pending changes.
5302                 self.holding_cell_update_fee = None;
5303                 let mut dropped_outbound_htlcs = Vec::with_capacity(self.holding_cell_htlc_updates.len());
5304                 self.holding_cell_htlc_updates.retain(|htlc_update| {
5305                         match htlc_update {
5306                                 &HTLCUpdateAwaitingACK::AddHTLC { ref payment_hash, ref source, .. } => {
5307                                         dropped_outbound_htlcs.push((source.clone(), payment_hash.clone()));
5308                                         false
5309                                 },
5310                                 _ => true
5311                         }
5312                 });
5313
5314                 Ok((shutdown, monitor_update, dropped_outbound_htlcs))
5315         }
5316
5317         /// Gets the latest commitment transaction and any dependent transactions for relay (forcing
5318         /// shutdown of this channel - no more calls into this Channel may be made afterwards except
5319         /// those explicitly stated to be allowed after shutdown completes, eg some simple getters).
5320         /// Also returns the list of payment_hashes for channels which we can safely fail backwards
5321         /// immediately (others we will have to allow to time out).
5322         pub fn force_shutdown(&mut self, should_broadcast: bool) -> (Option<(OutPoint, ChannelMonitorUpdate)>, Vec<(HTLCSource, PaymentHash)>) {
5323                 // Note that we MUST only generate a monitor update that indicates force-closure - we're
5324                 // called during initialization prior to the chain_monitor in the encompassing ChannelManager
5325                 // being fully configured in some cases. Thus, its likely any monitor events we generate will
5326                 // be delayed in being processed! See the docs for `ChannelManagerReadArgs` for more.
5327                 assert!(self.channel_state != ChannelState::ShutdownComplete as u32);
5328
5329                 // We go ahead and "free" any holding cell HTLCs or HTLCs we haven't yet committed to and
5330                 // return them to fail the payment.
5331                 let mut dropped_outbound_htlcs = Vec::with_capacity(self.holding_cell_htlc_updates.len());
5332                 for htlc_update in self.holding_cell_htlc_updates.drain(..) {
5333                         match htlc_update {
5334                                 HTLCUpdateAwaitingACK::AddHTLC { source, payment_hash, .. } => {
5335                                         dropped_outbound_htlcs.push((source, payment_hash));
5336                                 },
5337                                 _ => {}
5338                         }
5339                 }
5340                 let monitor_update = if let Some(funding_txo) = self.get_funding_txo() {
5341                         // If we haven't yet exchanged funding signatures (ie channel_state < FundingSent),
5342                         // returning a channel monitor update here would imply a channel monitor update before
5343                         // we even registered the channel monitor to begin with, which is invalid.
5344                         // Thus, if we aren't actually at a point where we could conceivably broadcast the
5345                         // funding transaction, don't return a funding txo (which prevents providing the
5346                         // monitor update to the user, even if we return one).
5347                         // See test_duplicate_chan_id and test_pre_lockin_no_chan_closed_update for more.
5348                         if self.channel_state & (ChannelState::FundingSent as u32 | ChannelState::ChannelFunded as u32 | ChannelState::ShutdownComplete as u32) != 0 {
5349                                 self.latest_monitor_update_id += 1;
5350                                 Some((funding_txo, ChannelMonitorUpdate {
5351                                         update_id: self.latest_monitor_update_id,
5352                                         updates: vec![ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast }],
5353                                 }))
5354                         } else { None }
5355                 } else { None };
5356
5357                 self.channel_state = ChannelState::ShutdownComplete as u32;
5358                 self.update_time_counter += 1;
5359                 (monitor_update, dropped_outbound_htlcs)
5360         }
5361 }
5362
5363 const SERIALIZATION_VERSION: u8 = 2;
5364 const MIN_SERIALIZATION_VERSION: u8 = 1;
5365
5366 impl_writeable_tlv_based_enum!(InboundHTLCRemovalReason,;
5367         (0, FailRelay),
5368         (1, FailMalformed),
5369         (2, Fulfill),
5370 );
5371
5372 impl Writeable for ChannelUpdateStatus {
5373         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
5374                 // We only care about writing out the current state as it was announced, ie only either
5375                 // Enabled or Disabled. In the case of DisabledStaged, we most recently announced the
5376                 // channel as enabled, so we write 0. For EnabledStaged, we similarly write a 1.
5377                 match self {
5378                         ChannelUpdateStatus::Enabled => 0u8.write(writer)?,
5379                         ChannelUpdateStatus::DisabledStaged => 0u8.write(writer)?,
5380                         ChannelUpdateStatus::EnabledStaged => 1u8.write(writer)?,
5381                         ChannelUpdateStatus::Disabled => 1u8.write(writer)?,
5382                 }
5383                 Ok(())
5384         }
5385 }
5386
5387 impl Readable for ChannelUpdateStatus {
5388         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
5389                 Ok(match <u8 as Readable>::read(reader)? {
5390                         0 => ChannelUpdateStatus::Enabled,
5391                         1 => ChannelUpdateStatus::Disabled,
5392                         _ => return Err(DecodeError::InvalidValue),
5393                 })
5394         }
5395 }
5396
5397 impl Writeable for AnnouncementSigsState {
5398         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
5399                 // We only care about writing out the current state as if we had just disconnected, at
5400                 // which point we always set anything but AnnouncementSigsReceived to NotSent.
5401                 match self {
5402                         AnnouncementSigsState::NotSent => 0u8.write(writer),
5403                         AnnouncementSigsState::MessageSent => 0u8.write(writer),
5404                         AnnouncementSigsState::Committed => 0u8.write(writer),
5405                         AnnouncementSigsState::PeerReceived => 1u8.write(writer),
5406                 }
5407         }
5408 }
5409
5410 impl Readable for AnnouncementSigsState {
5411         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
5412                 Ok(match <u8 as Readable>::read(reader)? {
5413                         0 => AnnouncementSigsState::NotSent,
5414                         1 => AnnouncementSigsState::PeerReceived,
5415                         _ => return Err(DecodeError::InvalidValue),
5416                 })
5417         }
5418 }
5419
5420 impl<Signer: Sign> Writeable for Channel<Signer> {
5421         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
5422                 // Note that we write out as if remove_uncommitted_htlcs_and_mark_paused had just been
5423                 // called.
5424
5425                 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
5426
5427                 self.user_id.write(writer)?;
5428
5429                 // Write out the old serialization for the config object. This is read by version-1
5430                 // deserializers, but we will read the version in the TLV at the end instead.
5431                 self.config.forwarding_fee_proportional_millionths.write(writer)?;
5432                 self.config.cltv_expiry_delta.write(writer)?;
5433                 self.config.announced_channel.write(writer)?;
5434                 self.config.commit_upfront_shutdown_pubkey.write(writer)?;
5435
5436                 self.channel_id.write(writer)?;
5437                 (self.channel_state | ChannelState::PeerDisconnected as u32).write(writer)?;
5438                 self.channel_value_satoshis.write(writer)?;
5439
5440                 self.latest_monitor_update_id.write(writer)?;
5441
5442                 let mut key_data = VecWriter(Vec::new());
5443                 self.holder_signer.write(&mut key_data)?;
5444                 assert!(key_data.0.len() < core::usize::MAX);
5445                 assert!(key_data.0.len() < core::u32::MAX as usize);
5446                 (key_data.0.len() as u32).write(writer)?;
5447                 writer.write_all(&key_data.0[..])?;
5448
5449                 // Write out the old serialization for shutdown_pubkey for backwards compatibility, if
5450                 // deserialized from that format.
5451                 match self.shutdown_scriptpubkey.as_ref().and_then(|script| script.as_legacy_pubkey()) {
5452                         Some(shutdown_pubkey) => shutdown_pubkey.write(writer)?,
5453                         None => [0u8; PUBLIC_KEY_SIZE].write(writer)?,
5454                 }
5455                 self.destination_script.write(writer)?;
5456
5457                 self.cur_holder_commitment_transaction_number.write(writer)?;
5458                 self.cur_counterparty_commitment_transaction_number.write(writer)?;
5459                 self.value_to_self_msat.write(writer)?;
5460
5461                 let mut dropped_inbound_htlcs = 0;
5462                 for htlc in self.pending_inbound_htlcs.iter() {
5463                         if let InboundHTLCState::RemoteAnnounced(_) = htlc.state {
5464                                 dropped_inbound_htlcs += 1;
5465                         }
5466                 }
5467                 (self.pending_inbound_htlcs.len() as u64 - dropped_inbound_htlcs).write(writer)?;
5468                 for htlc in self.pending_inbound_htlcs.iter() {
5469                         if let &InboundHTLCState::RemoteAnnounced(_) = &htlc.state {
5470                                 continue; // Drop
5471                         }
5472                         htlc.htlc_id.write(writer)?;
5473                         htlc.amount_msat.write(writer)?;
5474                         htlc.cltv_expiry.write(writer)?;
5475                         htlc.payment_hash.write(writer)?;
5476                         match &htlc.state {
5477                                 &InboundHTLCState::RemoteAnnounced(_) => unreachable!(),
5478                                 &InboundHTLCState::AwaitingRemoteRevokeToAnnounce(ref htlc_state) => {
5479                                         1u8.write(writer)?;
5480                                         htlc_state.write(writer)?;
5481                                 },
5482                                 &InboundHTLCState::AwaitingAnnouncedRemoteRevoke(ref htlc_state) => {
5483                                         2u8.write(writer)?;
5484                                         htlc_state.write(writer)?;
5485                                 },
5486                                 &InboundHTLCState::Committed => {
5487                                         3u8.write(writer)?;
5488                                 },
5489                                 &InboundHTLCState::LocalRemoved(ref removal_reason) => {
5490                                         4u8.write(writer)?;
5491                                         removal_reason.write(writer)?;
5492                                 },
5493                         }
5494                 }
5495
5496                 (self.pending_outbound_htlcs.len() as u64).write(writer)?;
5497                 for htlc in self.pending_outbound_htlcs.iter() {
5498                         htlc.htlc_id.write(writer)?;
5499                         htlc.amount_msat.write(writer)?;
5500                         htlc.cltv_expiry.write(writer)?;
5501                         htlc.payment_hash.write(writer)?;
5502                         htlc.source.write(writer)?;
5503                         match &htlc.state {
5504                                 &OutboundHTLCState::LocalAnnounced(ref onion_packet) => {
5505                                         0u8.write(writer)?;
5506                                         onion_packet.write(writer)?;
5507                                 },
5508                                 &OutboundHTLCState::Committed => {
5509                                         1u8.write(writer)?;
5510                                 },
5511                                 &OutboundHTLCState::RemoteRemoved(_) => {
5512                                         // Treat this as a Committed because we haven't received the CS - they'll
5513                                         // resend the claim/fail on reconnect as we all (hopefully) the missing CS.
5514                                         1u8.write(writer)?;
5515                                 },
5516                                 &OutboundHTLCState::AwaitingRemoteRevokeToRemove(ref fail_reason) => {
5517                                         3u8.write(writer)?;
5518                                         fail_reason.write(writer)?;
5519                                 },
5520                                 &OutboundHTLCState::AwaitingRemovedRemoteRevoke(ref fail_reason) => {
5521                                         4u8.write(writer)?;
5522                                         fail_reason.write(writer)?;
5523                                 },
5524                         }
5525                 }
5526
5527                 (self.holding_cell_htlc_updates.len() as u64).write(writer)?;
5528                 for update in self.holding_cell_htlc_updates.iter() {
5529                         match update {
5530                                 &HTLCUpdateAwaitingACK::AddHTLC { ref amount_msat, ref cltv_expiry, ref payment_hash, ref source, ref onion_routing_packet } => {
5531                                         0u8.write(writer)?;
5532                                         amount_msat.write(writer)?;
5533                                         cltv_expiry.write(writer)?;
5534                                         payment_hash.write(writer)?;
5535                                         source.write(writer)?;
5536                                         onion_routing_packet.write(writer)?;
5537                                 },
5538                                 &HTLCUpdateAwaitingACK::ClaimHTLC { ref payment_preimage, ref htlc_id } => {
5539                                         1u8.write(writer)?;
5540                                         payment_preimage.write(writer)?;
5541                                         htlc_id.write(writer)?;
5542                                 },
5543                                 &HTLCUpdateAwaitingACK::FailHTLC { ref htlc_id, ref err_packet } => {
5544                                         2u8.write(writer)?;
5545                                         htlc_id.write(writer)?;
5546                                         err_packet.write(writer)?;
5547                                 }
5548                         }
5549                 }
5550
5551                 match self.resend_order {
5552                         RAACommitmentOrder::CommitmentFirst => 0u8.write(writer)?,
5553                         RAACommitmentOrder::RevokeAndACKFirst => 1u8.write(writer)?,
5554                 }
5555
5556                 self.monitor_pending_funding_locked.write(writer)?;
5557                 self.monitor_pending_revoke_and_ack.write(writer)?;
5558                 self.monitor_pending_commitment_signed.write(writer)?;
5559
5560                 (self.monitor_pending_forwards.len() as u64).write(writer)?;
5561                 for &(ref pending_forward, ref htlc_id) in self.monitor_pending_forwards.iter() {
5562                         pending_forward.write(writer)?;
5563                         htlc_id.write(writer)?;
5564                 }
5565
5566                 (self.monitor_pending_failures.len() as u64).write(writer)?;
5567                 for &(ref htlc_source, ref payment_hash, ref fail_reason) in self.monitor_pending_failures.iter() {
5568                         htlc_source.write(writer)?;
5569                         payment_hash.write(writer)?;
5570                         fail_reason.write(writer)?;
5571                 }
5572
5573                 if self.is_outbound() {
5574                         self.pending_update_fee.map(|(a, _)| a).write(writer)?;
5575                 } else if let Some((feerate, FeeUpdateState::AwaitingRemoteRevokeToAnnounce)) = self.pending_update_fee {
5576                         Some(feerate).write(writer)?;
5577                 } else {
5578                         // As for inbound HTLCs, if the update was only announced and never committed in a
5579                         // commitment_signed, drop it.
5580                         None::<u32>.write(writer)?;
5581                 }
5582                 self.holding_cell_update_fee.write(writer)?;
5583
5584                 self.next_holder_htlc_id.write(writer)?;
5585                 (self.next_counterparty_htlc_id - dropped_inbound_htlcs).write(writer)?;
5586                 self.update_time_counter.write(writer)?;
5587                 self.feerate_per_kw.write(writer)?;
5588
5589                 // Versions prior to 0.0.100 expected to read the fields of `last_sent_closing_fee` here,
5590                 // however we are supposed to restart shutdown fee negotiation on reconnect (and wipe
5591                 // `last_send_closing_fee` in `remove_uncommitted_htlcs_and_mark_paused`) so we should never
5592                 // consider the stale state on reload.
5593                 0u8.write(writer)?;
5594
5595                 self.funding_tx_confirmed_in.write(writer)?;
5596                 self.funding_tx_confirmation_height.write(writer)?;
5597                 self.short_channel_id.write(writer)?;
5598
5599                 self.counterparty_dust_limit_satoshis.write(writer)?;
5600                 self.holder_dust_limit_satoshis.write(writer)?;
5601                 self.counterparty_max_htlc_value_in_flight_msat.write(writer)?;
5602
5603                 // Note that this field is ignored by 0.0.99+ as the TLV Optional variant is used instead.
5604                 self.counterparty_selected_channel_reserve_satoshis.unwrap_or(0).write(writer)?;
5605
5606                 self.counterparty_htlc_minimum_msat.write(writer)?;
5607                 self.holder_htlc_minimum_msat.write(writer)?;
5608                 self.counterparty_max_accepted_htlcs.write(writer)?;
5609
5610                 // Note that this field is ignored by 0.0.99+ as the TLV Optional variant is used instead.
5611                 self.minimum_depth.unwrap_or(0).write(writer)?;
5612
5613                 match &self.counterparty_forwarding_info {
5614                         Some(info) => {
5615                                 1u8.write(writer)?;
5616                                 info.fee_base_msat.write(writer)?;
5617                                 info.fee_proportional_millionths.write(writer)?;
5618                                 info.cltv_expiry_delta.write(writer)?;
5619                         },
5620                         None => 0u8.write(writer)?
5621                 }
5622
5623                 self.channel_transaction_parameters.write(writer)?;
5624                 self.funding_transaction.write(writer)?;
5625
5626                 self.counterparty_cur_commitment_point.write(writer)?;
5627                 self.counterparty_prev_commitment_point.write(writer)?;
5628                 self.counterparty_node_id.write(writer)?;
5629
5630                 self.counterparty_shutdown_scriptpubkey.write(writer)?;
5631
5632                 self.commitment_secrets.write(writer)?;
5633
5634                 self.channel_update_status.write(writer)?;
5635
5636                 #[cfg(any(test, feature = "fuzztarget"))]
5637                 (self.historical_inbound_htlc_fulfills.len() as u64).write(writer)?;
5638                 #[cfg(any(test, feature = "fuzztarget"))]
5639                 for htlc in self.historical_inbound_htlc_fulfills.iter() {
5640                         htlc.write(writer)?;
5641                 }
5642
5643                 // If the channel type is something other than only-static-remote-key, then we need to have
5644                 // older clients fail to deserialize this channel at all. If the type is
5645                 // only-static-remote-key, we simply consider it "default" and don't write the channel type
5646                 // out at all.
5647                 let chan_type = if self.channel_type != ChannelTypeFeatures::only_static_remote_key() {
5648                         Some(&self.channel_type) } else { None };
5649
5650                 // The same logic applies for `holder_selected_channel_reserve_satoshis` and
5651                 // `holder_max_htlc_value_in_flight_msat` values other than the defaults.
5652                 let serialized_holder_selected_reserve =
5653                         if self.holder_selected_channel_reserve_satoshis != Self::get_holder_selected_channel_reserve_satoshis(self.channel_value_satoshis)
5654                         { Some(self.holder_selected_channel_reserve_satoshis) } else { None };
5655                 let serialized_holder_htlc_max_in_flight =
5656                         if self.holder_max_htlc_value_in_flight_msat != Self::get_holder_max_htlc_value_in_flight_msat(self.channel_value_satoshis)
5657                         { Some(self.holder_max_htlc_value_in_flight_msat) } else { None };
5658
5659                 write_tlv_fields!(writer, {
5660                         (0, self.announcement_sigs, option),
5661                         // minimum_depth and counterparty_selected_channel_reserve_satoshis used to have a
5662                         // default value instead of being Option<>al. Thus, to maintain compatibility we write
5663                         // them twice, once with their original default values above, and once as an option
5664                         // here. On the read side, old versions will simply ignore the odd-type entries here,
5665                         // and new versions map the default values to None and allow the TLV entries here to
5666                         // override that.
5667                         (1, self.minimum_depth, option),
5668                         (2, chan_type, option),
5669                         (3, self.counterparty_selected_channel_reserve_satoshis, option),
5670                         (4, serialized_holder_selected_reserve, option),
5671                         (5, self.config, required),
5672                         (6, serialized_holder_htlc_max_in_flight, option),
5673                         (7, self.shutdown_scriptpubkey, option),
5674                         (9, self.target_closing_feerate_sats_per_kw, option),
5675                         (11, self.monitor_pending_finalized_fulfills, vec_type),
5676                         (13, self.channel_creation_height, required),
5677                         (15, self.announcement_sigs_state, required),
5678                         (17, self.latest_inbound_scid_alias, option),
5679                 });
5680
5681                 Ok(())
5682         }
5683 }
5684
5685 const MAX_ALLOC_SIZE: usize = 64*1024;
5686 impl<'a, Signer: Sign, K: Deref> ReadableArgs<(&'a K, u32)> for Channel<Signer>
5687                 where K::Target: KeysInterface<Signer = Signer> {
5688         fn read<R : io::Read>(reader: &mut R, args: (&'a K, u32)) -> Result<Self, DecodeError> {
5689                 let (keys_source, serialized_height) = args;
5690                 let ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
5691
5692                 let user_id = Readable::read(reader)?;
5693
5694                 let mut config = Some(ChannelConfig::default());
5695                 if ver == 1 {
5696                         // Read the old serialization of the ChannelConfig from version 0.0.98.
5697                         config.as_mut().unwrap().forwarding_fee_proportional_millionths = Readable::read(reader)?;
5698                         config.as_mut().unwrap().cltv_expiry_delta = Readable::read(reader)?;
5699                         config.as_mut().unwrap().announced_channel = Readable::read(reader)?;
5700                         config.as_mut().unwrap().commit_upfront_shutdown_pubkey = Readable::read(reader)?;
5701                 } else {
5702                         // Read the 8 bytes of backwards-compatibility ChannelConfig data.
5703                         let mut _val: u64 = Readable::read(reader)?;
5704                 }
5705
5706                 let channel_id = Readable::read(reader)?;
5707                 let channel_state = Readable::read(reader)?;
5708                 let channel_value_satoshis = Readable::read(reader)?;
5709
5710                 let latest_monitor_update_id = Readable::read(reader)?;
5711
5712                 let keys_len: u32 = Readable::read(reader)?;
5713                 let mut keys_data = Vec::with_capacity(cmp::min(keys_len as usize, MAX_ALLOC_SIZE));
5714                 while keys_data.len() != keys_len as usize {
5715                         // Read 1KB at a time to avoid accidentally allocating 4GB on corrupted channel keys
5716                         let mut data = [0; 1024];
5717                         let read_slice = &mut data[0..cmp::min(1024, keys_len as usize - keys_data.len())];
5718                         reader.read_exact(read_slice)?;
5719                         keys_data.extend_from_slice(read_slice);
5720                 }
5721                 let holder_signer = keys_source.read_chan_signer(&keys_data)?;
5722
5723                 // Read the old serialization for shutdown_pubkey, preferring the TLV field later if set.
5724                 let mut shutdown_scriptpubkey = match <PublicKey as Readable>::read(reader) {
5725                         Ok(pubkey) => Some(ShutdownScript::new_p2wpkh_from_pubkey(pubkey)),
5726                         Err(_) => None,
5727                 };
5728                 let destination_script = Readable::read(reader)?;
5729
5730                 let cur_holder_commitment_transaction_number = Readable::read(reader)?;
5731                 let cur_counterparty_commitment_transaction_number = Readable::read(reader)?;
5732                 let value_to_self_msat = Readable::read(reader)?;
5733
5734                 let pending_inbound_htlc_count: u64 = Readable::read(reader)?;
5735                 let mut pending_inbound_htlcs = Vec::with_capacity(cmp::min(pending_inbound_htlc_count as usize, OUR_MAX_HTLCS as usize));
5736                 for _ in 0..pending_inbound_htlc_count {
5737                         pending_inbound_htlcs.push(InboundHTLCOutput {
5738                                 htlc_id: Readable::read(reader)?,
5739                                 amount_msat: Readable::read(reader)?,
5740                                 cltv_expiry: Readable::read(reader)?,
5741                                 payment_hash: Readable::read(reader)?,
5742                                 state: match <u8 as Readable>::read(reader)? {
5743                                         1 => InboundHTLCState::AwaitingRemoteRevokeToAnnounce(Readable::read(reader)?),
5744                                         2 => InboundHTLCState::AwaitingAnnouncedRemoteRevoke(Readable::read(reader)?),
5745                                         3 => InboundHTLCState::Committed,
5746                                         4 => InboundHTLCState::LocalRemoved(Readable::read(reader)?),
5747                                         _ => return Err(DecodeError::InvalidValue),
5748                                 },
5749                         });
5750                 }
5751
5752                 let pending_outbound_htlc_count: u64 = Readable::read(reader)?;
5753                 let mut pending_outbound_htlcs = Vec::with_capacity(cmp::min(pending_outbound_htlc_count as usize, OUR_MAX_HTLCS as usize));
5754                 for _ in 0..pending_outbound_htlc_count {
5755                         pending_outbound_htlcs.push(OutboundHTLCOutput {
5756                                 htlc_id: Readable::read(reader)?,
5757                                 amount_msat: Readable::read(reader)?,
5758                                 cltv_expiry: Readable::read(reader)?,
5759                                 payment_hash: Readable::read(reader)?,
5760                                 source: Readable::read(reader)?,
5761                                 state: match <u8 as Readable>::read(reader)? {
5762                                         0 => OutboundHTLCState::LocalAnnounced(Box::new(Readable::read(reader)?)),
5763                                         1 => OutboundHTLCState::Committed,
5764                                         2 => OutboundHTLCState::RemoteRemoved(Readable::read(reader)?),
5765                                         3 => OutboundHTLCState::AwaitingRemoteRevokeToRemove(Readable::read(reader)?),
5766                                         4 => OutboundHTLCState::AwaitingRemovedRemoteRevoke(Readable::read(reader)?),
5767                                         _ => return Err(DecodeError::InvalidValue),
5768                                 },
5769                         });
5770                 }
5771
5772                 let holding_cell_htlc_update_count: u64 = Readable::read(reader)?;
5773                 let mut holding_cell_htlc_updates = Vec::with_capacity(cmp::min(holding_cell_htlc_update_count as usize, OUR_MAX_HTLCS as usize*2));
5774                 for _ in 0..holding_cell_htlc_update_count {
5775                         holding_cell_htlc_updates.push(match <u8 as Readable>::read(reader)? {
5776                                 0 => HTLCUpdateAwaitingACK::AddHTLC {
5777                                         amount_msat: Readable::read(reader)?,
5778                                         cltv_expiry: Readable::read(reader)?,
5779                                         payment_hash: Readable::read(reader)?,
5780                                         source: Readable::read(reader)?,
5781                                         onion_routing_packet: Readable::read(reader)?,
5782                                 },
5783                                 1 => HTLCUpdateAwaitingACK::ClaimHTLC {
5784                                         payment_preimage: Readable::read(reader)?,
5785                                         htlc_id: Readable::read(reader)?,
5786                                 },
5787                                 2 => HTLCUpdateAwaitingACK::FailHTLC {
5788                                         htlc_id: Readable::read(reader)?,
5789                                         err_packet: Readable::read(reader)?,
5790                                 },
5791                                 _ => return Err(DecodeError::InvalidValue),
5792                         });
5793                 }
5794
5795                 let resend_order = match <u8 as Readable>::read(reader)? {
5796                         0 => RAACommitmentOrder::CommitmentFirst,
5797                         1 => RAACommitmentOrder::RevokeAndACKFirst,
5798                         _ => return Err(DecodeError::InvalidValue),
5799                 };
5800
5801                 let monitor_pending_funding_locked = Readable::read(reader)?;
5802                 let monitor_pending_revoke_and_ack = Readable::read(reader)?;
5803                 let monitor_pending_commitment_signed = Readable::read(reader)?;
5804
5805                 let monitor_pending_forwards_count: u64 = Readable::read(reader)?;
5806                 let mut monitor_pending_forwards = Vec::with_capacity(cmp::min(monitor_pending_forwards_count as usize, OUR_MAX_HTLCS as usize));
5807                 for _ in 0..monitor_pending_forwards_count {
5808                         monitor_pending_forwards.push((Readable::read(reader)?, Readable::read(reader)?));
5809                 }
5810
5811                 let monitor_pending_failures_count: u64 = Readable::read(reader)?;
5812                 let mut monitor_pending_failures = Vec::with_capacity(cmp::min(monitor_pending_failures_count as usize, OUR_MAX_HTLCS as usize));
5813                 for _ in 0..monitor_pending_failures_count {
5814                         monitor_pending_failures.push((Readable::read(reader)?, Readable::read(reader)?, Readable::read(reader)?));
5815                 }
5816
5817                 let pending_update_fee_value: Option<u32> = Readable::read(reader)?;
5818
5819                 let holding_cell_update_fee = Readable::read(reader)?;
5820
5821                 let next_holder_htlc_id = Readable::read(reader)?;
5822                 let next_counterparty_htlc_id = Readable::read(reader)?;
5823                 let update_time_counter = Readable::read(reader)?;
5824                 let feerate_per_kw = Readable::read(reader)?;
5825
5826                 // Versions prior to 0.0.100 expected to read the fields of `last_sent_closing_fee` here,
5827                 // however we are supposed to restart shutdown fee negotiation on reconnect (and wipe
5828                 // `last_send_closing_fee` in `remove_uncommitted_htlcs_and_mark_paused`) so we should never
5829                 // consider the stale state on reload.
5830                 match <u8 as Readable>::read(reader)? {
5831                         0 => {},
5832                         1 => {
5833                                 let _: u32 = Readable::read(reader)?;
5834                                 let _: u64 = Readable::read(reader)?;
5835                                 let _: Signature = Readable::read(reader)?;
5836                         },
5837                         _ => return Err(DecodeError::InvalidValue),
5838                 }
5839
5840                 let funding_tx_confirmed_in = Readable::read(reader)?;
5841                 let funding_tx_confirmation_height = Readable::read(reader)?;
5842                 let short_channel_id = Readable::read(reader)?;
5843
5844                 let counterparty_dust_limit_satoshis = Readable::read(reader)?;
5845                 let holder_dust_limit_satoshis = Readable::read(reader)?;
5846                 let counterparty_max_htlc_value_in_flight_msat = Readable::read(reader)?;
5847                 let mut counterparty_selected_channel_reserve_satoshis = None;
5848                 if ver == 1 {
5849                         // Read the old serialization from version 0.0.98.
5850                         counterparty_selected_channel_reserve_satoshis = Some(Readable::read(reader)?);
5851                 } else {
5852                         // Read the 8 bytes of backwards-compatibility data.
5853                         let _dummy: u64 = Readable::read(reader)?;
5854                 }
5855                 let counterparty_htlc_minimum_msat = Readable::read(reader)?;
5856                 let holder_htlc_minimum_msat = Readable::read(reader)?;
5857                 let counterparty_max_accepted_htlcs = Readable::read(reader)?;
5858
5859                 let mut minimum_depth = None;
5860                 if ver == 1 {
5861                         // Read the old serialization from version 0.0.98.
5862                         minimum_depth = Some(Readable::read(reader)?);
5863                 } else {
5864                         // Read the 4 bytes of backwards-compatibility data.
5865                         let _dummy: u32 = Readable::read(reader)?;
5866                 }
5867
5868                 let counterparty_forwarding_info = match <u8 as Readable>::read(reader)? {
5869                         0 => None,
5870                         1 => Some(CounterpartyForwardingInfo {
5871                                 fee_base_msat: Readable::read(reader)?,
5872                                 fee_proportional_millionths: Readable::read(reader)?,
5873                                 cltv_expiry_delta: Readable::read(reader)?,
5874                         }),
5875                         _ => return Err(DecodeError::InvalidValue),
5876                 };
5877
5878                 let channel_parameters: ChannelTransactionParameters = Readable::read(reader)?;
5879                 let funding_transaction = Readable::read(reader)?;
5880
5881                 let counterparty_cur_commitment_point = Readable::read(reader)?;
5882
5883                 let counterparty_prev_commitment_point = Readable::read(reader)?;
5884                 let counterparty_node_id = Readable::read(reader)?;
5885
5886                 let counterparty_shutdown_scriptpubkey = Readable::read(reader)?;
5887                 let commitment_secrets = Readable::read(reader)?;
5888
5889                 let channel_update_status = Readable::read(reader)?;
5890
5891                 #[cfg(any(test, feature = "fuzztarget"))]
5892                 let mut historical_inbound_htlc_fulfills = HashSet::new();
5893                 #[cfg(any(test, feature = "fuzztarget"))]
5894                 {
5895                         let htlc_fulfills_len: u64 = Readable::read(reader)?;
5896                         for _ in 0..htlc_fulfills_len {
5897                                 assert!(historical_inbound_htlc_fulfills.insert(Readable::read(reader)?));
5898                         }
5899                 }
5900
5901                 let pending_update_fee = if let Some(feerate) = pending_update_fee_value {
5902                         Some((feerate, if channel_parameters.is_outbound_from_holder {
5903                                 FeeUpdateState::Outbound
5904                         } else {
5905                                 FeeUpdateState::AwaitingRemoteRevokeToAnnounce
5906                         }))
5907                 } else {
5908                         None
5909                 };
5910
5911                 let mut announcement_sigs = None;
5912                 let mut target_closing_feerate_sats_per_kw = None;
5913                 let mut monitor_pending_finalized_fulfills = Some(Vec::new());
5914                 let mut holder_selected_channel_reserve_satoshis = Some(Self::get_holder_selected_channel_reserve_satoshis(channel_value_satoshis));
5915                 let mut holder_max_htlc_value_in_flight_msat = Some(Self::get_holder_max_htlc_value_in_flight_msat(channel_value_satoshis));
5916                 // Prior to supporting channel type negotiation, all of our channels were static_remotekey
5917                 // only, so we default to that if none was written.
5918                 let mut channel_type = Some(ChannelTypeFeatures::only_static_remote_key());
5919                 let mut channel_creation_height = Some(serialized_height);
5920                 // If we read an old Channel, for simplicity we just treat it as "we never sent an
5921                 // AnnouncementSignatures" which implies we'll re-send it on reconnect, but that's fine.
5922                 let mut announcement_sigs_state = Some(AnnouncementSigsState::NotSent);
5923                 let mut latest_inbound_scid_alias = None;
5924                 read_tlv_fields!(reader, {
5925                         (0, announcement_sigs, option),
5926                         (1, minimum_depth, option),
5927                         (2, channel_type, option),
5928                         (3, counterparty_selected_channel_reserve_satoshis, option),
5929                         (4, holder_selected_channel_reserve_satoshis, option),
5930                         (5, config, option), // Note that if none is provided we will *not* overwrite the existing one.
5931                         (6, holder_max_htlc_value_in_flight_msat, option),
5932                         (7, shutdown_scriptpubkey, option),
5933                         (9, target_closing_feerate_sats_per_kw, option),
5934                         (11, monitor_pending_finalized_fulfills, vec_type),
5935                         (13, channel_creation_height, option),
5936                         (15, announcement_sigs_state, option),
5937                         (17, latest_inbound_scid_alias, option),
5938                 });
5939
5940                 let chan_features = channel_type.as_ref().unwrap();
5941                 if chan_features.supports_unknown_bits() || chan_features.requires_unknown_bits() {
5942                         // If the channel was written by a new version and negotiated with features we don't
5943                         // understand yet, refuse to read it.
5944                         return Err(DecodeError::UnknownRequiredFeature);
5945                 }
5946
5947                 if channel_parameters.opt_anchors.is_some() {
5948                         // Relax this check when ChannelTypeFeatures supports anchors.
5949                         return Err(DecodeError::InvalidValue);
5950                 }
5951
5952                 let mut secp_ctx = Secp256k1::new();
5953                 secp_ctx.seeded_randomize(&keys_source.get_secure_random_bytes());
5954
5955                 Ok(Channel {
5956                         user_id,
5957
5958                         config: config.unwrap(),
5959                         channel_id,
5960                         channel_state,
5961                         announcement_sigs_state: announcement_sigs_state.unwrap(),
5962                         secp_ctx,
5963                         channel_value_satoshis,
5964
5965                         latest_monitor_update_id,
5966
5967                         holder_signer,
5968                         shutdown_scriptpubkey,
5969                         destination_script,
5970
5971                         cur_holder_commitment_transaction_number,
5972                         cur_counterparty_commitment_transaction_number,
5973                         value_to_self_msat,
5974
5975                         pending_inbound_htlcs,
5976                         pending_outbound_htlcs,
5977                         holding_cell_htlc_updates,
5978
5979                         resend_order,
5980
5981                         monitor_pending_funding_locked,
5982                         monitor_pending_revoke_and_ack,
5983                         monitor_pending_commitment_signed,
5984                         monitor_pending_forwards,
5985                         monitor_pending_failures,
5986                         monitor_pending_finalized_fulfills: monitor_pending_finalized_fulfills.unwrap(),
5987
5988                         pending_update_fee,
5989                         holding_cell_update_fee,
5990                         next_holder_htlc_id,
5991                         next_counterparty_htlc_id,
5992                         update_time_counter,
5993                         feerate_per_kw,
5994
5995                         #[cfg(debug_assertions)]
5996                         holder_max_commitment_tx_output: Mutex::new((0, 0)),
5997                         #[cfg(debug_assertions)]
5998                         counterparty_max_commitment_tx_output: Mutex::new((0, 0)),
5999
6000                         last_sent_closing_fee: None,
6001                         pending_counterparty_closing_signed: None,
6002                         closing_fee_limits: None,
6003                         target_closing_feerate_sats_per_kw,
6004
6005                         funding_tx_confirmed_in,
6006                         funding_tx_confirmation_height,
6007                         short_channel_id,
6008                         channel_creation_height: channel_creation_height.unwrap(),
6009
6010                         counterparty_dust_limit_satoshis,
6011                         holder_dust_limit_satoshis,
6012                         counterparty_max_htlc_value_in_flight_msat,
6013                         holder_max_htlc_value_in_flight_msat: holder_max_htlc_value_in_flight_msat.unwrap(),
6014                         counterparty_selected_channel_reserve_satoshis,
6015                         holder_selected_channel_reserve_satoshis: holder_selected_channel_reserve_satoshis.unwrap(),
6016                         counterparty_htlc_minimum_msat,
6017                         holder_htlc_minimum_msat,
6018                         counterparty_max_accepted_htlcs,
6019                         minimum_depth,
6020
6021                         counterparty_forwarding_info,
6022
6023                         channel_transaction_parameters: channel_parameters,
6024                         funding_transaction,
6025
6026                         counterparty_cur_commitment_point,
6027                         counterparty_prev_commitment_point,
6028                         counterparty_node_id,
6029
6030                         counterparty_shutdown_scriptpubkey,
6031
6032                         commitment_secrets,
6033
6034                         channel_update_status,
6035                         closing_signed_in_flight: false,
6036
6037                         announcement_sigs,
6038
6039                         #[cfg(any(test, feature = "fuzztarget"))]
6040                         next_local_commitment_tx_fee_info_cached: Mutex::new(None),
6041                         #[cfg(any(test, feature = "fuzztarget"))]
6042                         next_remote_commitment_tx_fee_info_cached: Mutex::new(None),
6043
6044                         workaround_lnd_bug_4006: None,
6045
6046                         latest_inbound_scid_alias,
6047
6048                         #[cfg(any(test, feature = "fuzztarget"))]
6049                         historical_inbound_htlc_fulfills,
6050
6051                         channel_type: channel_type.unwrap(),
6052                 })
6053         }
6054 }
6055
6056 #[cfg(test)]
6057 mod tests {
6058         use bitcoin::util::bip143;
6059         use bitcoin::consensus::encode::serialize;
6060         use bitcoin::blockdata::script::{Script, Builder};
6061         use bitcoin::blockdata::transaction::{Transaction, TxOut, SigHashType};
6062         use bitcoin::blockdata::constants::genesis_block;
6063         use bitcoin::blockdata::opcodes;
6064         use bitcoin::network::constants::Network;
6065         use bitcoin::hashes::hex::FromHex;
6066         use hex;
6067         use ln::{PaymentPreimage, PaymentHash};
6068         use ln::channelmanager::{HTLCSource, PaymentId};
6069         use ln::channel::{Channel,InboundHTLCOutput,OutboundHTLCOutput,InboundHTLCState,OutboundHTLCState,HTLCOutputInCommitment,HTLCCandidate,HTLCInitiator,TxCreationKeys};
6070         use ln::channel::MAX_FUNDING_SATOSHIS;
6071         use ln::features::InitFeatures;
6072         use ln::msgs::{ChannelUpdate, DataLossProtect, DecodeError, OptionalField, UnsignedChannelUpdate};
6073         use ln::script::ShutdownScript;
6074         use ln::chan_utils;
6075         use ln::chan_utils::{ChannelPublicKeys, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters, HTLC_SUCCESS_TX_WEIGHT, HTLC_TIMEOUT_TX_WEIGHT};
6076         use chain::BestBlock;
6077         use chain::chaininterface::{FeeEstimator,ConfirmationTarget};
6078         use chain::keysinterface::{InMemorySigner, KeyMaterial, KeysInterface, BaseSign};
6079         use chain::transaction::OutPoint;
6080         use util::config::UserConfig;
6081         use util::enforcing_trait_impls::EnforcingSigner;
6082         use util::errors::APIError;
6083         use util::test_utils;
6084         use util::test_utils::OnGetShutdownScriptpubkey;
6085         use util::logger::Logger;
6086         use bitcoin::secp256k1::{Secp256k1, Message, Signature, All};
6087         use bitcoin::secp256k1::ffi::Signature as FFISignature;
6088         use bitcoin::secp256k1::key::{SecretKey,PublicKey};
6089         use bitcoin::secp256k1::recovery::RecoverableSignature;
6090         use bitcoin::hashes::sha256::Hash as Sha256;
6091         use bitcoin::hashes::Hash;
6092         use bitcoin::hash_types::{Txid, WPubkeyHash};
6093         use core::num::NonZeroU8;
6094         use sync::Arc;
6095         use prelude::*;
6096
6097         struct TestFeeEstimator {
6098                 fee_est: u32
6099         }
6100         impl FeeEstimator for TestFeeEstimator {
6101                 fn get_est_sat_per_1000_weight(&self, _: ConfirmationTarget) -> u32 {
6102                         self.fee_est
6103                 }
6104         }
6105
6106         #[test]
6107         fn test_max_funding_satoshis() {
6108                 assert!(MAX_FUNDING_SATOSHIS <= 21_000_000 * 100_000_000,
6109                         "MAX_FUNDING_SATOSHIS is greater than all satoshis in existence");
6110         }
6111
6112         struct Keys {
6113                 signer: InMemorySigner,
6114         }
6115         impl KeysInterface for Keys {
6116                 type Signer = InMemorySigner;
6117
6118                 fn get_node_secret(&self) -> SecretKey { panic!(); }
6119                 fn get_inbound_payment_key_material(&self) -> KeyMaterial { panic!(); }
6120                 fn get_destination_script(&self) -> Script {
6121                         let secp_ctx = Secp256k1::signing_only();
6122                         let channel_monitor_claim_key = SecretKey::from_slice(&hex::decode("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap();
6123                         let channel_monitor_claim_key_hash = WPubkeyHash::hash(&PublicKey::from_secret_key(&secp_ctx, &channel_monitor_claim_key).serialize());
6124                         Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&channel_monitor_claim_key_hash[..]).into_script()
6125                 }
6126
6127                 fn get_shutdown_scriptpubkey(&self) -> ShutdownScript {
6128                         let secp_ctx = Secp256k1::signing_only();
6129                         let channel_close_key = SecretKey::from_slice(&hex::decode("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap();
6130                         ShutdownScript::new_p2wpkh_from_pubkey(PublicKey::from_secret_key(&secp_ctx, &channel_close_key))
6131                 }
6132
6133                 fn get_channel_signer(&self, _inbound: bool, _channel_value_satoshis: u64) -> InMemorySigner {
6134                         self.signer.clone()
6135                 }
6136                 fn get_secure_random_bytes(&self) -> [u8; 32] { [0; 32] }
6137                 fn read_chan_signer(&self, _data: &[u8]) -> Result<Self::Signer, DecodeError> { panic!(); }
6138                 fn sign_invoice(&self, _invoice_preimage: Vec<u8>) -> Result<RecoverableSignature, ()> { panic!(); }
6139         }
6140
6141         fn public_from_secret_hex(secp_ctx: &Secp256k1<All>, hex: &str) -> PublicKey {
6142                 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&hex::decode(hex).unwrap()[..]).unwrap())
6143         }
6144
6145         #[test]
6146         fn upfront_shutdown_script_incompatibility() {
6147                 let features = InitFeatures::known().clear_shutdown_anysegwit();
6148                 let non_v0_segwit_shutdown_script =
6149                         ShutdownScript::new_witness_program(NonZeroU8::new(16).unwrap(), &[0, 40]).unwrap();
6150
6151                 let seed = [42; 32];
6152                 let network = Network::Testnet;
6153                 let keys_provider = test_utils::TestKeysInterface::new(&seed, network);
6154                 keys_provider.expect(OnGetShutdownScriptpubkey {
6155                         returns: non_v0_segwit_shutdown_script.clone(),
6156                 });
6157
6158                 let fee_estimator = TestFeeEstimator { fee_est: 253 };
6159                 let secp_ctx = Secp256k1::new();
6160                 let node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
6161                 let config = UserConfig::default();
6162                 match Channel::<EnforcingSigner>::new_outbound(&&fee_estimator, &&keys_provider, node_id, &features, 10000000, 100000, 42, &config, 0) {
6163                         Err(APIError::IncompatibleShutdownScript { script }) => {
6164                                 assert_eq!(script.into_inner(), non_v0_segwit_shutdown_script.into_inner());
6165                         },
6166                         Err(e) => panic!("Unexpected error: {:?}", e),
6167                         Ok(_) => panic!("Expected error"),
6168                 }
6169         }
6170
6171         // Check that, during channel creation, we use the same feerate in the open channel message
6172         // as we do in the Channel object creation itself.
6173         #[test]
6174         fn test_open_channel_msg_fee() {
6175                 let original_fee = 253;
6176                 let mut fee_est = TestFeeEstimator{fee_est: original_fee };
6177                 let secp_ctx = Secp256k1::new();
6178                 let seed = [42; 32];
6179                 let network = Network::Testnet;
6180                 let keys_provider = test_utils::TestKeysInterface::new(&seed, network);
6181
6182                 let node_a_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
6183                 let config = UserConfig::default();
6184                 let node_a_chan = Channel::<EnforcingSigner>::new_outbound(&&fee_est, &&keys_provider, node_a_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config, 0).unwrap();
6185
6186                 // Now change the fee so we can check that the fee in the open_channel message is the
6187                 // same as the old fee.
6188                 fee_est.fee_est = 500;
6189                 let open_channel_msg = node_a_chan.get_open_channel(genesis_block(network).header.block_hash());
6190                 assert_eq!(open_channel_msg.feerate_per_kw, original_fee);
6191         }
6192
6193         #[test]
6194         fn test_holder_vs_counterparty_dust_limit() {
6195                 // Test that when calculating the local and remote commitment transaction fees, the correct
6196                 // dust limits are used.
6197                 let feeest = TestFeeEstimator{fee_est: 15000};
6198                 let secp_ctx = Secp256k1::new();
6199                 let seed = [42; 32];
6200                 let network = Network::Testnet;
6201                 let keys_provider = test_utils::TestKeysInterface::new(&seed, network);
6202                 let logger = test_utils::TestLogger::new();
6203
6204                 // Go through the flow of opening a channel between two nodes, making sure
6205                 // they have different dust limits.
6206
6207                 // Create Node A's channel pointing to Node B's pubkey
6208                 let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
6209                 let config = UserConfig::default();
6210                 let mut node_a_chan = Channel::<EnforcingSigner>::new_outbound(&&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config, 0).unwrap();
6211
6212                 // Create Node B's channel by receiving Node A's open_channel message
6213                 // Make sure A's dust limit is as we expect.
6214                 let open_channel_msg = node_a_chan.get_open_channel(genesis_block(network).header.block_hash());
6215                 let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[7; 32]).unwrap());
6216                 let node_b_chan = Channel::<EnforcingSigner>::new_from_req(&&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), &open_channel_msg, 7, &config, 0, &&logger).unwrap();
6217
6218                 // Node B --> Node A: accept channel, explicitly setting B's dust limit.
6219                 let mut accept_channel_msg = node_b_chan.get_accept_channel();
6220                 accept_channel_msg.dust_limit_satoshis = 546;
6221                 node_a_chan.accept_channel(&accept_channel_msg, &config, &InitFeatures::known()).unwrap();
6222                 node_a_chan.holder_dust_limit_satoshis = 1560;
6223
6224                 // Put some inbound and outbound HTLCs in A's channel.
6225                 let htlc_amount_msat = 11_092_000; // put an amount below A's effective dust limit but above B's.
6226                 node_a_chan.pending_inbound_htlcs.push(InboundHTLCOutput {
6227                         htlc_id: 0,
6228                         amount_msat: htlc_amount_msat,
6229                         payment_hash: PaymentHash(Sha256::hash(&[42; 32]).into_inner()),
6230                         cltv_expiry: 300000000,
6231                         state: InboundHTLCState::Committed,
6232                 });
6233
6234                 node_a_chan.pending_outbound_htlcs.push(OutboundHTLCOutput {
6235                         htlc_id: 1,
6236                         amount_msat: htlc_amount_msat, // put an amount below A's dust amount but above B's.
6237                         payment_hash: PaymentHash(Sha256::hash(&[43; 32]).into_inner()),
6238                         cltv_expiry: 200000000,
6239                         state: OutboundHTLCState::Committed,
6240                         source: HTLCSource::OutboundRoute {
6241                                 path: Vec::new(),
6242                                 session_priv: SecretKey::from_slice(&hex::decode("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap(),
6243                                 first_hop_htlc_msat: 548,
6244                                 payment_id: PaymentId([42; 32]),
6245                                 payment_secret: None,
6246                                 payee: None,
6247                         }
6248                 });
6249
6250                 // Make sure when Node A calculates their local commitment transaction, none of the HTLCs pass
6251                 // the dust limit check.
6252                 let htlc_candidate = HTLCCandidate::new(htlc_amount_msat, HTLCInitiator::LocalOffered);
6253                 let local_commit_tx_fee = node_a_chan.next_local_commit_tx_fee_msat(htlc_candidate, None);
6254                 let local_commit_fee_0_htlcs = Channel::<EnforcingSigner>::commit_tx_fee_msat(node_a_chan.feerate_per_kw, 0);
6255                 assert_eq!(local_commit_tx_fee, local_commit_fee_0_htlcs);
6256
6257                 // Finally, make sure that when Node A calculates the remote's commitment transaction fees, all
6258                 // of the HTLCs are seen to be above the dust limit.
6259                 node_a_chan.channel_transaction_parameters.is_outbound_from_holder = false;
6260                 let remote_commit_fee_3_htlcs = Channel::<EnforcingSigner>::commit_tx_fee_msat(node_a_chan.feerate_per_kw, 3);
6261                 let htlc_candidate = HTLCCandidate::new(htlc_amount_msat, HTLCInitiator::LocalOffered);
6262                 let remote_commit_tx_fee = node_a_chan.next_remote_commit_tx_fee_msat(htlc_candidate, None);
6263                 assert_eq!(remote_commit_tx_fee, remote_commit_fee_3_htlcs);
6264         }
6265
6266         #[test]
6267         fn test_timeout_vs_success_htlc_dust_limit() {
6268                 // Make sure that when `next_remote_commit_tx_fee_msat` and `next_local_commit_tx_fee_msat`
6269                 // calculate the real dust limits for HTLCs (i.e. the dust limit given by the counterparty
6270                 // *plus* the fees paid for the HTLC) they don't swap `HTLC_SUCCESS_TX_WEIGHT` for
6271                 // `HTLC_TIMEOUT_TX_WEIGHT`, and vice versa.
6272                 let fee_est = TestFeeEstimator{fee_est: 253 };
6273                 let secp_ctx = Secp256k1::new();
6274                 let seed = [42; 32];
6275                 let network = Network::Testnet;
6276                 let keys_provider = test_utils::TestKeysInterface::new(&seed, network);
6277
6278                 let node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
6279                 let config = UserConfig::default();
6280                 let mut chan = Channel::<EnforcingSigner>::new_outbound(&&fee_est, &&keys_provider, node_id, &InitFeatures::known(), 10000000, 100000, 42, &config, 0).unwrap();
6281
6282                 let commitment_tx_fee_0_htlcs = Channel::<EnforcingSigner>::commit_tx_fee_msat(chan.feerate_per_kw, 0);
6283                 let commitment_tx_fee_1_htlc = Channel::<EnforcingSigner>::commit_tx_fee_msat(chan.feerate_per_kw, 1);
6284
6285                 // If HTLC_SUCCESS_TX_WEIGHT and HTLC_TIMEOUT_TX_WEIGHT were swapped: then this HTLC would be
6286                 // counted as dust when it shouldn't be.
6287                 let htlc_amt_above_timeout = ((253 * HTLC_TIMEOUT_TX_WEIGHT / 1000) + chan.holder_dust_limit_satoshis + 1) * 1000;
6288                 let htlc_candidate = HTLCCandidate::new(htlc_amt_above_timeout, HTLCInitiator::LocalOffered);
6289                 let commitment_tx_fee = chan.next_local_commit_tx_fee_msat(htlc_candidate, None);
6290                 assert_eq!(commitment_tx_fee, commitment_tx_fee_1_htlc);
6291
6292                 // If swapped: this HTLC would be counted as non-dust when it shouldn't be.
6293                 let dust_htlc_amt_below_success = ((253 * HTLC_SUCCESS_TX_WEIGHT / 1000) + chan.holder_dust_limit_satoshis - 1) * 1000;
6294                 let htlc_candidate = HTLCCandidate::new(dust_htlc_amt_below_success, HTLCInitiator::RemoteOffered);
6295                 let commitment_tx_fee = chan.next_local_commit_tx_fee_msat(htlc_candidate, None);
6296                 assert_eq!(commitment_tx_fee, commitment_tx_fee_0_htlcs);
6297
6298                 chan.channel_transaction_parameters.is_outbound_from_holder = false;
6299
6300                 // If swapped: this HTLC would be counted as non-dust when it shouldn't be.
6301                 let dust_htlc_amt_above_timeout = ((253 * HTLC_TIMEOUT_TX_WEIGHT / 1000) + chan.counterparty_dust_limit_satoshis + 1) * 1000;
6302                 let htlc_candidate = HTLCCandidate::new(dust_htlc_amt_above_timeout, HTLCInitiator::LocalOffered);
6303                 let commitment_tx_fee = chan.next_remote_commit_tx_fee_msat(htlc_candidate, None);
6304                 assert_eq!(commitment_tx_fee, commitment_tx_fee_0_htlcs);
6305
6306                 // If swapped: this HTLC would be counted as dust when it shouldn't be.
6307                 let htlc_amt_below_success = ((253 * HTLC_SUCCESS_TX_WEIGHT / 1000) + chan.counterparty_dust_limit_satoshis - 1) * 1000;
6308                 let htlc_candidate = HTLCCandidate::new(htlc_amt_below_success, HTLCInitiator::RemoteOffered);
6309                 let commitment_tx_fee = chan.next_remote_commit_tx_fee_msat(htlc_candidate, None);
6310                 assert_eq!(commitment_tx_fee, commitment_tx_fee_1_htlc);
6311         }
6312
6313         #[test]
6314         fn channel_reestablish_no_updates() {
6315                 let feeest = TestFeeEstimator{fee_est: 15000};
6316                 let logger = test_utils::TestLogger::new();
6317                 let secp_ctx = Secp256k1::new();
6318                 let seed = [42; 32];
6319                 let network = Network::Testnet;
6320                 let best_block = BestBlock::from_genesis(network);
6321                 let chain_hash = best_block.block_hash();
6322                 let keys_provider = test_utils::TestKeysInterface::new(&seed, network);
6323
6324                 // Go through the flow of opening a channel between two nodes.
6325
6326                 // Create Node A's channel pointing to Node B's pubkey
6327                 let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
6328                 let config = UserConfig::default();
6329                 let mut node_a_chan = Channel::<EnforcingSigner>::new_outbound(&&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config, 0).unwrap();
6330
6331                 // Create Node B's channel by receiving Node A's open_channel message
6332                 let open_channel_msg = node_a_chan.get_open_channel(chain_hash);
6333                 let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[7; 32]).unwrap());
6334                 let mut node_b_chan = Channel::<EnforcingSigner>::new_from_req(&&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), &open_channel_msg, 7, &config, 0, &&logger).unwrap();
6335
6336                 // Node B --> Node A: accept channel
6337                 let accept_channel_msg = node_b_chan.get_accept_channel();
6338                 node_a_chan.accept_channel(&accept_channel_msg, &config, &InitFeatures::known()).unwrap();
6339
6340                 // Node A --> Node B: funding created
6341                 let output_script = node_a_chan.get_funding_redeemscript();
6342                 let tx = Transaction { version: 1, lock_time: 0, input: Vec::new(), output: vec![TxOut {
6343                         value: 10000000, script_pubkey: output_script.clone(),
6344                 }]};
6345                 let funding_outpoint = OutPoint{ txid: tx.txid(), index: 0 };
6346                 let funding_created_msg = node_a_chan.get_outbound_funding_created(tx.clone(), funding_outpoint, &&logger).unwrap();
6347                 let (funding_signed_msg, _) = node_b_chan.funding_created(&funding_created_msg, best_block, &&logger).unwrap();
6348
6349                 // Node B --> Node A: funding signed
6350                 let _ = node_a_chan.funding_signed(&funding_signed_msg, best_block, &&logger);
6351
6352                 // Now disconnect the two nodes and check that the commitment point in
6353                 // Node B's channel_reestablish message is sane.
6354                 node_b_chan.remove_uncommitted_htlcs_and_mark_paused(&&logger);
6355                 let msg = node_b_chan.get_channel_reestablish(&&logger);
6356                 assert_eq!(msg.next_local_commitment_number, 1); // now called next_commitment_number
6357                 assert_eq!(msg.next_remote_commitment_number, 0); // now called next_revocation_number
6358                 match msg.data_loss_protect {
6359                         OptionalField::Present(DataLossProtect { your_last_per_commitment_secret, .. }) => {
6360                                 assert_eq!(your_last_per_commitment_secret, [0; 32]);
6361                         },
6362                         _ => panic!()
6363                 }
6364
6365                 // Check that the commitment point in Node A's channel_reestablish message
6366                 // is sane.
6367                 node_a_chan.remove_uncommitted_htlcs_and_mark_paused(&&logger);
6368                 let msg = node_a_chan.get_channel_reestablish(&&logger);
6369                 assert_eq!(msg.next_local_commitment_number, 1); // now called next_commitment_number
6370                 assert_eq!(msg.next_remote_commitment_number, 0); // now called next_revocation_number
6371                 match msg.data_loss_protect {
6372                         OptionalField::Present(DataLossProtect { your_last_per_commitment_secret, .. }) => {
6373                                 assert_eq!(your_last_per_commitment_secret, [0; 32]);
6374                         },
6375                         _ => panic!()
6376                 }
6377         }
6378
6379         #[test]
6380         fn channel_update() {
6381                 let feeest = TestFeeEstimator{fee_est: 15000};
6382                 let secp_ctx = Secp256k1::new();
6383                 let seed = [42; 32];
6384                 let network = Network::Testnet;
6385                 let chain_hash = genesis_block(network).header.block_hash();
6386                 let keys_provider = test_utils::TestKeysInterface::new(&seed, network);
6387
6388                 // Create a channel.
6389                 let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
6390                 let config = UserConfig::default();
6391                 let mut node_a_chan = Channel::<EnforcingSigner>::new_outbound(&&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config, 0).unwrap();
6392                 assert!(node_a_chan.counterparty_forwarding_info.is_none());
6393                 assert_eq!(node_a_chan.holder_htlc_minimum_msat, 1); // the default
6394                 assert!(node_a_chan.counterparty_forwarding_info().is_none());
6395
6396                 // Make sure that receiving a channel update will update the Channel as expected.
6397                 let update = ChannelUpdate {
6398                         contents: UnsignedChannelUpdate {
6399                                 chain_hash,
6400                                 short_channel_id: 0,
6401                                 timestamp: 0,
6402                                 flags: 0,
6403                                 cltv_expiry_delta: 100,
6404                                 htlc_minimum_msat: 5,
6405                                 htlc_maximum_msat: OptionalField::Absent,
6406                                 fee_base_msat: 110,
6407                                 fee_proportional_millionths: 11,
6408                                 excess_data: Vec::new(),
6409                         },
6410                         signature: Signature::from(unsafe { FFISignature::new() })
6411                 };
6412                 node_a_chan.channel_update(&update).unwrap();
6413
6414                 // The counterparty can send an update with a higher minimum HTLC, but that shouldn't
6415                 // change our official htlc_minimum_msat.
6416                 assert_eq!(node_a_chan.holder_htlc_minimum_msat, 1);
6417                 match node_a_chan.counterparty_forwarding_info() {
6418                         Some(info) => {
6419                                 assert_eq!(info.cltv_expiry_delta, 100);
6420                                 assert_eq!(info.fee_base_msat, 110);
6421                                 assert_eq!(info.fee_proportional_millionths, 11);
6422                         },
6423                         None => panic!("expected counterparty forwarding info to be Some")
6424                 }
6425         }
6426
6427         #[test]
6428         fn outbound_commitment_test() {
6429                 // Test vectors from BOLT 3 Appendix C:
6430                 let feeest = TestFeeEstimator{fee_est: 15000};
6431                 let logger : Arc<Logger> = Arc::new(test_utils::TestLogger::new());
6432                 let secp_ctx = Secp256k1::new();
6433
6434                 let mut signer = InMemorySigner::new(
6435                         &secp_ctx,
6436                         SecretKey::from_slice(&hex::decode("4242424242424242424242424242424242424242424242424242424242424242").unwrap()[..]).unwrap(),
6437                         SecretKey::from_slice(&hex::decode("30ff4956bbdd3222d44cc5e8a1261dab1e07957bdac5ae88fe3261ef321f3749").unwrap()[..]).unwrap(),
6438                         SecretKey::from_slice(&hex::decode("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap(),
6439                         SecretKey::from_slice(&hex::decode("1111111111111111111111111111111111111111111111111111111111111111").unwrap()[..]).unwrap(),
6440                         SecretKey::from_slice(&hex::decode("3333333333333333333333333333333333333333333333333333333333333333").unwrap()[..]).unwrap(),
6441                         SecretKey::from_slice(&hex::decode("1111111111111111111111111111111111111111111111111111111111111111").unwrap()[..]).unwrap(),
6442
6443                         // These aren't set in the test vectors:
6444                         [0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff],
6445                         10_000_000,
6446                         [0; 32]
6447                 );
6448
6449                 assert_eq!(signer.pubkeys().funding_pubkey.serialize()[..],
6450                                 hex::decode("023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb").unwrap()[..]);
6451                 let keys_provider = Keys { signer: signer.clone() };
6452
6453                 let counterparty_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
6454                 let mut config = UserConfig::default();
6455                 config.channel_options.announced_channel = false;
6456                 let mut chan = Channel::<InMemorySigner>::new_outbound(&&feeest, &&keys_provider, counterparty_node_id, &InitFeatures::known(), 10_000_000, 100000, 42, &config, 0).unwrap(); // Nothing uses their network key in this test
6457                 chan.holder_dust_limit_satoshis = 546;
6458                 chan.counterparty_selected_channel_reserve_satoshis = Some(0); // Filled in in accept_channel
6459
6460                 let funding_info = OutPoint{ txid: Txid::from_hex("8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be").unwrap(), index: 0 };
6461
6462                 let counterparty_pubkeys = ChannelPublicKeys {
6463                         funding_pubkey: public_from_secret_hex(&secp_ctx, "1552dfba4f6cf29a62a0af13c8d6981d36d0ef8d61ba10fb0fe90da7634d7e13"),
6464                         revocation_basepoint: PublicKey::from_slice(&hex::decode("02466d7fcae563e5cb09a0d1870bb580344804617879a14949cf22285f1bae3f27").unwrap()[..]).unwrap(),
6465                         payment_point: public_from_secret_hex(&secp_ctx, "4444444444444444444444444444444444444444444444444444444444444444"),
6466                         delayed_payment_basepoint: public_from_secret_hex(&secp_ctx, "1552dfba4f6cf29a62a0af13c8d6981d36d0ef8d61ba10fb0fe90da7634d7e13"),
6467                         htlc_basepoint: public_from_secret_hex(&secp_ctx, "4444444444444444444444444444444444444444444444444444444444444444")
6468                 };
6469                 chan.channel_transaction_parameters.counterparty_parameters = Some(
6470                         CounterpartyChannelTransactionParameters {
6471                                 pubkeys: counterparty_pubkeys.clone(),
6472                                 selected_contest_delay: 144
6473                         });
6474                 chan.channel_transaction_parameters.funding_outpoint = Some(funding_info);
6475                 signer.ready_channel(&chan.channel_transaction_parameters);
6476
6477                 assert_eq!(counterparty_pubkeys.payment_point.serialize()[..],
6478                            hex::decode("032c0b7cf95324a07d05398b240174dc0c2be444d96b159aa6c7f7b1e668680991").unwrap()[..]);
6479
6480                 assert_eq!(counterparty_pubkeys.funding_pubkey.serialize()[..],
6481                            hex::decode("030e9f7b623d2ccc7c9bd44d66d5ce21ce504c0acf6385a132cec6d3c39fa711c1").unwrap()[..]);
6482
6483                 assert_eq!(counterparty_pubkeys.htlc_basepoint.serialize()[..],
6484                            hex::decode("032c0b7cf95324a07d05398b240174dc0c2be444d96b159aa6c7f7b1e668680991").unwrap()[..]);
6485
6486                 // We can't just use build_holder_transaction_keys here as the per_commitment_secret is not
6487                 // derived from a commitment_seed, so instead we copy it here and call
6488                 // build_commitment_transaction.
6489                 let delayed_payment_base = &chan.holder_signer.pubkeys().delayed_payment_basepoint;
6490                 let per_commitment_secret = SecretKey::from_slice(&hex::decode("1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100").unwrap()[..]).unwrap();
6491                 let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret);
6492                 let htlc_basepoint = &chan.holder_signer.pubkeys().htlc_basepoint;
6493                 let keys = TxCreationKeys::derive_new(&secp_ctx, &per_commitment_point, delayed_payment_base, htlc_basepoint, &counterparty_pubkeys.revocation_basepoint, &counterparty_pubkeys.htlc_basepoint).unwrap();
6494
6495                 macro_rules! test_commitment {
6496                         ( $counterparty_sig_hex: expr, $sig_hex: expr, $tx_hex: expr, {
6497                                 $( { $htlc_idx: expr, $counterparty_htlc_sig_hex: expr, $htlc_sig_hex: expr, $htlc_tx_hex: expr } ), *
6498                         } ) => { {
6499                                 let (commitment_tx, htlcs): (_, Vec<HTLCOutputInCommitment>) = {
6500                                         let mut commitment_stats = chan.build_commitment_transaction(0xffffffffffff - 42, &keys, true, false, &logger);
6501
6502                                         let htlcs = commitment_stats.htlcs_included.drain(..)
6503                                                 .filter_map(|(htlc, _)| if htlc.transaction_output_index.is_some() { Some(htlc) } else { None })
6504                                                 .collect();
6505                                         (commitment_stats.tx, htlcs)
6506                                 };
6507                                 let trusted_tx = commitment_tx.trust();
6508                                 let unsigned_tx = trusted_tx.built_transaction();
6509                                 let redeemscript = chan.get_funding_redeemscript();
6510                                 let counterparty_signature = Signature::from_der(&hex::decode($counterparty_sig_hex).unwrap()[..]).unwrap();
6511                                 let sighash = unsigned_tx.get_sighash_all(&redeemscript, chan.channel_value_satoshis);
6512                                 secp_ctx.verify(&sighash, &counterparty_signature, chan.counterparty_funding_pubkey()).unwrap();
6513
6514                                 let mut per_htlc: Vec<(HTLCOutputInCommitment, Option<Signature>)> = Vec::new();
6515                                 per_htlc.clear(); // Don't warn about excess mut for no-HTLC calls
6516                                 let mut counterparty_htlc_sigs = Vec::new();
6517                                 counterparty_htlc_sigs.clear(); // Don't warn about excess mut for no-HTLC calls
6518                                 $({
6519                                         let remote_signature = Signature::from_der(&hex::decode($counterparty_htlc_sig_hex).unwrap()[..]).unwrap();
6520                                         per_htlc.push((htlcs[$htlc_idx].clone(), Some(remote_signature)));
6521                                         counterparty_htlc_sigs.push(remote_signature);
6522                                 })*
6523                                 assert_eq!(htlcs.len(), per_htlc.len());
6524
6525                                 let holder_commitment_tx = HolderCommitmentTransaction::new(
6526                                         commitment_tx.clone(),
6527                                         counterparty_signature,
6528                                         counterparty_htlc_sigs,
6529                                         &chan.holder_signer.pubkeys().funding_pubkey,
6530                                         chan.counterparty_funding_pubkey()
6531                                 );
6532                                 let (holder_sig, htlc_sigs) = signer.sign_holder_commitment_and_htlcs(&holder_commitment_tx, &secp_ctx).unwrap();
6533                                 assert_eq!(Signature::from_der(&hex::decode($sig_hex).unwrap()[..]).unwrap(), holder_sig, "holder_sig");
6534
6535                                 let funding_redeemscript = chan.get_funding_redeemscript();
6536                                 let tx = holder_commitment_tx.add_holder_sig(&funding_redeemscript, holder_sig);
6537                                 assert_eq!(serialize(&tx)[..], hex::decode($tx_hex).unwrap()[..], "tx");
6538
6539                                 // ((htlc, counterparty_sig), (index, holder_sig))
6540                                 let mut htlc_sig_iter = holder_commitment_tx.htlcs().iter().zip(&holder_commitment_tx.counterparty_htlc_sigs).zip(htlc_sigs.iter().enumerate());
6541
6542                                 $({
6543                                         let remote_signature = Signature::from_der(&hex::decode($counterparty_htlc_sig_hex).unwrap()[..]).unwrap();
6544
6545                                         let ref htlc = htlcs[$htlc_idx];
6546                                         let opt_anchors = false;
6547                                         let htlc_tx = chan_utils::build_htlc_transaction(&unsigned_tx.txid, chan.feerate_per_kw,
6548                                                 chan.get_counterparty_selected_contest_delay().unwrap(),
6549                                                 &htlc, opt_anchors, &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
6550                                         let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, opt_anchors, &keys);
6551                                         let htlc_sighash = Message::from_slice(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, SigHashType::All)[..]).unwrap();
6552                                         secp_ctx.verify(&htlc_sighash, &remote_signature, &keys.countersignatory_htlc_key).unwrap();
6553
6554                                         let mut preimage: Option<PaymentPreimage> = None;
6555                                         if !htlc.offered {
6556                                                 for i in 0..5 {
6557                                                         let out = PaymentHash(Sha256::hash(&[i; 32]).into_inner());
6558                                                         if out == htlc.payment_hash {
6559                                                                 preimage = Some(PaymentPreimage([i; 32]));
6560                                                         }
6561                                                 }
6562
6563                                                 assert!(preimage.is_some());
6564                                         }
6565
6566                                         let htlc_sig = htlc_sig_iter.next().unwrap();
6567                                         assert_eq!((htlc_sig.0).0.transaction_output_index, Some($htlc_idx), "output index");
6568
6569                                         let signature = Signature::from_der(&hex::decode($htlc_sig_hex).unwrap()[..]).unwrap();
6570                                         assert_eq!(signature, *(htlc_sig.1).1, "htlc sig");
6571                                         let index = (htlc_sig.1).0;
6572                                         let channel_parameters = chan.channel_transaction_parameters.as_holder_broadcastable();
6573                                         let trusted_tx = holder_commitment_tx.trust();
6574                                         assert_eq!(serialize(&trusted_tx.get_signed_htlc_tx(&channel_parameters, index, &(htlc_sig.0).1, (htlc_sig.1).1, &preimage))[..],
6575                                                         hex::decode($htlc_tx_hex).unwrap()[..], "htlc tx");
6576                                 })*
6577                                 assert!(htlc_sig_iter.next().is_none());
6578                         } }
6579                 }
6580
6581                 // simple commitment tx with no HTLCs
6582                 chan.value_to_self_msat = 7000000000;
6583
6584                 test_commitment!("3045022100c3127b33dcc741dd6b05b1e63cbd1a9a7d816f37af9b6756fa2376b056f032370220408b96279808fe57eb7e463710804cdf4f108388bc5cf722d8c848d2c7f9f3b0",
6585                                                  "30440220616210b2cc4d3afb601013c373bbd8aac54febd9f15400379a8cb65ce7deca60022034236c010991beb7ff770510561ae8dc885b8d38d1947248c38f2ae055647142",
6586                                                  "02000000000101bef67e4e2fb9ddeeb3461973cd4c62abb35050b1add772995b820b584a488489000000000038b02b8002c0c62d0000000000160014cc1b07838e387deacd0e5232e1e8b49f4c29e48454a56a00000000002200204adb4e2f00643db396dd120d4e7dc17625f5f2c11a40d857accc862d6b7dd80e04004730440220616210b2cc4d3afb601013c373bbd8aac54febd9f15400379a8cb65ce7deca60022034236c010991beb7ff770510561ae8dc885b8d38d1947248c38f2ae05564714201483045022100c3127b33dcc741dd6b05b1e63cbd1a9a7d816f37af9b6756fa2376b056f032370220408b96279808fe57eb7e463710804cdf4f108388bc5cf722d8c848d2c7f9f3b001475221023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb21030e9f7b623d2ccc7c9bd44d66d5ce21ce504c0acf6385a132cec6d3c39fa711c152ae3e195220", {});
6587
6588                 chan.pending_inbound_htlcs.push({
6589                         let mut out = InboundHTLCOutput{
6590                                 htlc_id: 0,
6591                                 amount_msat: 1000000,
6592                                 cltv_expiry: 500,
6593                                 payment_hash: PaymentHash([0; 32]),
6594                                 state: InboundHTLCState::Committed,
6595                         };
6596                         out.payment_hash.0 = Sha256::hash(&hex::decode("0000000000000000000000000000000000000000000000000000000000000000").unwrap()).into_inner();
6597                         out
6598                 });
6599                 chan.pending_inbound_htlcs.push({
6600                         let mut out = InboundHTLCOutput{
6601                                 htlc_id: 1,
6602                                 amount_msat: 2000000,
6603                                 cltv_expiry: 501,
6604                                 payment_hash: PaymentHash([0; 32]),
6605                                 state: InboundHTLCState::Committed,
6606                         };
6607                         out.payment_hash.0 = Sha256::hash(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()).into_inner();
6608                         out
6609                 });
6610                 chan.pending_outbound_htlcs.push({
6611                         let mut out = OutboundHTLCOutput{
6612                                 htlc_id: 2,
6613                                 amount_msat: 2000000,
6614                                 cltv_expiry: 502,
6615                                 payment_hash: PaymentHash([0; 32]),
6616                                 state: OutboundHTLCState::Committed,
6617                                 source: HTLCSource::dummy(),
6618                         };
6619                         out.payment_hash.0 = Sha256::hash(&hex::decode("0202020202020202020202020202020202020202020202020202020202020202").unwrap()).into_inner();
6620                         out
6621                 });
6622                 chan.pending_outbound_htlcs.push({
6623                         let mut out = OutboundHTLCOutput{
6624                                 htlc_id: 3,
6625                                 amount_msat: 3000000,
6626                                 cltv_expiry: 503,
6627                                 payment_hash: PaymentHash([0; 32]),
6628                                 state: OutboundHTLCState::Committed,
6629                                 source: HTLCSource::dummy(),
6630                         };
6631                         out.payment_hash.0 = Sha256::hash(&hex::decode("0303030303030303030303030303030303030303030303030303030303030303").unwrap()).into_inner();
6632                         out
6633                 });
6634                 chan.pending_inbound_htlcs.push({
6635                         let mut out = InboundHTLCOutput{
6636                                 htlc_id: 4,
6637                                 amount_msat: 4000000,
6638                                 cltv_expiry: 504,
6639                                 payment_hash: PaymentHash([0; 32]),
6640                                 state: InboundHTLCState::Committed,
6641                         };
6642                         out.payment_hash.0 = Sha256::hash(&hex::decode("0404040404040404040404040404040404040404040404040404040404040404").unwrap()).into_inner();
6643                         out
6644                 });
6645
6646                 // commitment tx with all five HTLCs untrimmed (minimum feerate)
6647                 chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
6648                 chan.feerate_per_kw = 0;
6649
6650                 test_commitment!("3044022009b048187705a8cbc9ad73adbe5af148c3d012e1f067961486c822c7af08158c022006d66f3704cfab3eb2dc49dae24e4aa22a6910fc9b424007583204e3621af2e5",
6651                                  "304402206fc2d1f10ea59951eefac0b4b7c396a3c3d87b71ff0b019796ef4535beaf36f902201765b0181e514d04f4c8ad75659d7037be26cdb3f8bb6f78fe61decef484c3ea",
6652                                  "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", {
6653
6654                                   { 0,
6655                                   "3045022100d9e29616b8f3959f1d3d7f7ce893ffedcdc407717d0de8e37d808c91d3a7c50d022078c3033f6d00095c8720a4bc943c1b45727818c082e4e3ddbc6d3116435b624b",
6656                                   "30440220636de5682ef0c5b61f124ec74e8aa2461a69777521d6998295dcea36bc3338110220165285594b23c50b28b82df200234566628a27bcd17f7f14404bd865354eb3ce",
6657                                   "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" },
6658
6659                                   { 1,
6660                                   "30440220649fe8b20e67e46cbb0d09b4acea87dbec001b39b08dee7bdd0b1f03922a8640022037c462dff79df501cecfdb12ea7f4de91f99230bb544726f6e04527b1f896004",
6661                                   "3045022100803159dee7935dba4a1d36a61055ce8fd62caa528573cc221ae288515405a252022029c59e7cffce374fe860100a4a63787e105c3cf5156d40b12dd53ff55ac8cf3f",
6662                                   "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" },
6663
6664                                   { 2,
6665                                   "30440220770fc321e97a19f38985f2e7732dd9fe08d16a2efa4bcbc0429400a447faf49102204d40b417f3113e1b0944ae0986f517564ab4acd3d190503faf97a6e420d43352",
6666                                   "3045022100a437cc2ce77400ecde441b3398fea3c3ad8bdad8132be818227fe3c5b8345989022069d45e7fa0ae551ec37240845e2c561ceb2567eacf3076a6a43a502d05865faa",
6667                                   "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" },
6668
6669                                   { 3,
6670                                   "304402207bcbf4f60a9829b05d2dbab84ed593e0291836be715dc7db6b72a64caf646af802201e489a5a84f7c5cc130398b841d138d031a5137ac8f4c49c770a4959dc3c1363",
6671                                   "304402203121d9b9c055f354304b016a36662ee99e1110d9501cb271b087ddb6f382c2c80220549882f3f3b78d9c492de47543cb9a697cecc493174726146536c5954dac7487",
6672                                   "02000000000101ab84ff284f162cfbfef241f853b47d4368d171f9e2a1445160cd591c4c7d882b03000000000000000001b80b0000000000002200204adb4e2f00643db396dd120d4e7dc17625f5f2c11a40d857accc862d6b7dd80e050047304402207bcbf4f60a9829b05d2dbab84ed593e0291836be715dc7db6b72a64caf646af802201e489a5a84f7c5cc130398b841d138d031a5137ac8f4c49c770a4959dc3c13630147304402203121d9b9c055f354304b016a36662ee99e1110d9501cb271b087ddb6f382c2c80220549882f3f3b78d9c492de47543cb9a697cecc493174726146536c5954dac748701008576a91414011f7254d96b819c76986c277d115efce6f7b58763ac67210394854aa6eab5b2a8122cc726e9dded053a2184d88256816826d6231c068d4a5b7c820120876475527c21030d417a46946384f88d5f3337267c5e579765875dc4daca813e21734b140639e752ae67a9148a486ff2e31d6158bf39e2608864d63fefd09d5b88ac6868f7010000" },
6673
6674                                   { 4,
6675                                   "3044022076dca5cb81ba7e466e349b7128cdba216d4d01659e29b96025b9524aaf0d1899022060de85697b88b21c749702b7d2cfa7dfeaa1f472c8f1d7d9c23f2bf968464b87",
6676                                   "3045022100d9080f103cc92bac15ec42464a95f070c7fb6925014e673ee2ea1374d36a7f7502200c65294d22eb20d48564954d5afe04a385551919d8b2ddb4ae2459daaeee1d95",
6677                                   "02000000000101ab84ff284f162cfbfef241f853b47d4368d171f9e2a1445160cd591c4c7d882b04000000000000000001a00f0000000000002200204adb4e2f00643db396dd120d4e7dc17625f5f2c11a40d857accc862d6b7dd80e0500473044022076dca5cb81ba7e466e349b7128cdba216d4d01659e29b96025b9524aaf0d1899022060de85697b88b21c749702b7d2cfa7dfeaa1f472c8f1d7d9c23f2bf968464b8701483045022100d9080f103cc92bac15ec42464a95f070c7fb6925014e673ee2ea1374d36a7f7502200c65294d22eb20d48564954d5afe04a385551919d8b2ddb4ae2459daaeee1d95012004040404040404040404040404040404040404040404040404040404040404048a76a91414011f7254d96b819c76986c277d115efce6f7b58763ac67210394854aa6eab5b2a8122cc726e9dded053a2184d88256816826d6231c068d4a5b7c8201208763a91418bc1a114ccf9c052d3d23e28d3b0a9d1227434288527c21030d417a46946384f88d5f3337267c5e579765875dc4daca813e21734b140639e752ae677502f801b175ac686800000000" }
6678                 } );
6679
6680                 // commitment tx with seven outputs untrimmed (maximum feerate)
6681                 chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
6682                 chan.feerate_per_kw = 647;
6683
6684                 test_commitment!("3045022100a135f9e8a5ed25f7277446c67956b00ce6f610ead2bdec2c2f686155b7814772022059f1f6e1a8b336a68efcc1af3fe4d422d4827332b5b067501b099c47b7b5b5ee",
6685                                  "30450221009ec15c687898bb4da8b3a833e5ab8bfc51ec6e9202aaa8e66611edfd4a85ed1102203d7183e45078b9735c93450bc3415d3e5a8c576141a711ec6ddcb4a893926bb7",
6686                                  "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", {
6687
6688                                   { 0,
6689                                   "30450221008437627f9ad84ac67052e2a414a4367b8556fd1f94d8b02590f89f50525cd33502205b9c21ff6e7fc864f2352746ad8ba59182510819acb644e25b8a12fc37bbf24f",
6690                                   "30440220344b0deb055230d01703e6c7acd45853c4af2328b49b5d8af4f88a060733406602202ea64f2a43d5751edfe75503cbc35a62e3141b5ed032fa03360faf4ca66f670b",
6691                                   "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" },
6692
6693                                   { 1,
6694                                   "304402205a67f92bf6845cf2892b48d874ac1daf88a36495cf8a06f93d83180d930a6f75022031da1621d95c3f335cc06a3056cf960199dae600b7cf89088f65fc53cdbef28c",
6695                                   "30450221009e5e3822b0185c6799a95288c597b671d6cc69ab80f43740f00c6c3d0752bdda02206da947a74bd98f3175324dc56fdba86cc783703a120a6f0297537e60632f4c7f",
6696                                   "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" },
6697
6698                                   { 2,
6699                                   "30440220437e21766054a3eef7f65690c5bcfa9920babbc5af92b819f772f6ea96df6c7402207173622024bd97328cfb26c6665e25c2f5d67c319443ccdc60c903217005d8c8",
6700                                   "3045022100fcfc47e36b712624677626cef3dc1d67f6583bd46926a6398fe6b00b0c9a37760220525788257b187fc775c6370d04eadf34d06f3650a63f8df851cee0ecb47a1673",
6701                                   "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" },
6702
6703                                   { 3,
6704                                   "304402207436e10737e4df499fc051686d3e11a5bb2310e4d1f1e691d287cef66514791202207cb58e71a6b7a42dd001b7e3ae672ea4f71ea3e1cd412b742e9124abb0739c64",
6705                                   "3045022100e78211b8409afb7255ffe37337da87f38646f1faebbdd61bc1920d69e3ead67a02201a626305adfcd16bfb7e9340928d9b6305464eab4aa4c4a3af6646e9b9f69dee",
6706                                   "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" },
6707
6708                                   { 4,
6709                                   "30450221009acd6a827a76bfee50806178dfe0495cd4e1d9c58279c194c7b01520fe68cb8d022024d439047c368883e570997a7d40f0b430cb5a742f507965e7d3063ae3feccca",
6710                                   "3044022048762cf546bbfe474f1536365ea7c416e3c0389d60558bc9412cb148fb6ab68202207215d7083b75c96ff9d2b08c59c34e287b66820f530b486a9aa4cdd9c347d5b9",
6711                                   "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" }
6712                 } );
6713
6714                 // commitment tx with six outputs untrimmed (minimum feerate)
6715                 chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
6716                 chan.feerate_per_kw = 648;
6717
6718                 test_commitment!("304402203948f900a5506b8de36a4d8502f94f21dd84fd9c2314ab427d52feaa7a0a19f2022059b6a37a4adaa2c5419dc8aea63c6e2a2ec4c4bde46207f6dc1fcd22152fc6e5",
6719                                  "3045022100b15f72908ba3382a34ca5b32519240a22300cc6015b6f9418635fb41f3d01d8802207adb331b9ed1575383dca0f2355e86c173802feecf8298fbea53b9d4610583e9",
6720                                  "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", {
6721
6722                                   { 0,
6723                                   "3045022100a031202f3be94678f0e998622ee95ebb6ada8da1e9a5110228b5e04a747351e4022010ca6a21e18314ed53cfaae3b1f51998552a61a468e596368829a50ce40110e0",
6724                                   "304502210097e1873b57267730154595187a34949d3744f52933070c74757005e61ce2112e02204ecfba2aa42d4f14bdf8bad4206bb97217b702e6c433e0e1b0ce6587e6d46ec6",
6725                                   "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" },
6726
6727                                   { 1,
6728                                   "304402202361012a634aee7835c5ecdd6413dcffa8f404b7e77364c792cff984e4ee71e90220715c5e90baa08daa45a7439b1ee4fa4843ed77b19c058240b69406606d384124",
6729                                   "3044022019de73b00f1d818fb388e83b2c8c31f6bce35ac624e215bc12f88f9dc33edf48022006ff814bb9f700ee6abc3294e146fac3efd4f13f0005236b41c0a946ee00c9ae",
6730                                   "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" },
6731
6732                                   { 2,
6733                                   "304402207e8e82cd71ed4febeb593732c260456836e97d81896153ecd2b3cf320ca6861702202dd4a30f68f98ced7cc56a36369ac1fdd978248c5ff4ed204fc00cc625532989",
6734                                   "3045022100bd0be6100c4fd8f102ec220e1b053e4c4e2ecca25615490150007b40d314dc3902201a1e0ea266965b43164d9e6576f58fa6726d42883dd1c3996d2925c2e2260796",
6735                                   "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" },
6736
6737                                   { 3,
6738                                   "3044022024cd52e4198c8ae0e414a86d86b5a65ea7450f2eb4e783096736d93395eca5ce022078f0094745b45be4d4b2b04dd5978c9e66ba49109e5704403e84aaf5f387d6be",
6739                                   "3045022100bbfb9d0a946d420807c86e985d636cceb16e71c3694ed186316251a00cbd807202207773223f9a337e145f64673825be9b30d07ef1542c82188b264bedcf7cda78c6",
6740                                   "020000000001010f44041fdfba175987cf4e6135ba2a154e3b7fb96483dc0ed5efc0678e5b6bf103000000000000000001d90d0000000000002200204adb4e2f00643db396dd120d4e7dc17625f5f2c11a40d857accc862d6b7dd80e0500473044022024cd52e4198c8ae0e414a86d86b5a65ea7450f2eb4e783096736d93395eca5ce022078f0094745b45be4d4b2b04dd5978c9e66ba49109e5704403e84aaf5f387d6be01483045022100bbfb9d0a946d420807c86e985d636cceb16e71c3694ed186316251a00cbd807202207773223f9a337e145f64673825be9b30d07ef1542c82188b264bedcf7cda78c6012004040404040404040404040404040404040404040404040404040404040404048a76a91414011f7254d96b819c76986c277d115efce6f7b58763ac67210394854aa6eab5b2a8122cc726e9dded053a2184d88256816826d6231c068d4a5b7c8201208763a91418bc1a114ccf9c052d3d23e28d3b0a9d1227434288527c21030d417a46946384f88d5f3337267c5e579765875dc4daca813e21734b140639e752ae677502f801b175ac686800000000" }
6741                 } );
6742
6743                 // commitment tx with six outputs untrimmed (maximum feerate)
6744                 chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
6745                 chan.feerate_per_kw = 2069;
6746
6747                 test_commitment!("304502210090b96a2498ce0c0f2fadbec2aab278fed54c1a7838df793ec4d2c78d96ec096202204fdd439c50f90d483baa7b68feeef4bd33bc277695405447bcd0bfb2ca34d7bc",
6748                                  "3045022100ad9a9bbbb75d506ca3b716b336ee3cf975dd7834fcf129d7dd188146eb58a8b4022061a759ee417339f7fe2ea1e8deb83abb6a74db31a09b7648a932a639cda23e33",
6749                                  "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", {
6750
6751                                   { 0,
6752                                   "3045022100f33513ee38abf1c582876f921f8fddc06acff48e04515532a32d3938de938ffd02203aa308a2c1863b7d6fdf53159a1465bf2e115c13152546cc5d74483ceaa7f699",
6753                                   "3045022100a637902a5d4c9ba9e7c472a225337d5aac9e2e3f6744f76e237132e7619ba0400220035c60d784a031c0d9f6df66b7eab8726a5c25397399ee4aa960842059eb3f9d",
6754                                   "02000000000101adbe717a63fb658add30ada1e6e12ed257637581898abe475c11d7bbcd65bd4d0000000000000000000175020000000000002200204adb4e2f00643db396dd120d4e7dc17625f5f2c11a40d857accc862d6b7dd80e0500483045022100f33513ee38abf1c582876f921f8fddc06acff48e04515532a32d3938de938ffd02203aa308a2c1863b7d6fdf53159a1465bf2e115c13152546cc5d74483ceaa7f69901483045022100a637902a5d4c9ba9e7c472a225337d5aac9e2e3f6744f76e237132e7619ba0400220035c60d784a031c0d9f6df66b7eab8726a5c25397399ee4aa960842059eb3f9d01008576a91414011f7254d96b819c76986c277d115efce6f7b58763ac67210394854aa6eab5b2a8122cc726e9dded053a2184d88256816826d6231c068d4a5b7c820120876475527c21030d417a46946384f88d5f3337267c5e579765875dc4daca813e21734b140639e752ae67a914b43e1b38138a41b37f7cd9a1d274bc63e3a9b5d188ac6868f6010000" },
6755
6756                                   { 1,
6757                                   "3045022100ce07682cf4b90093c22dc2d9ab2a77ad6803526b655ef857221cc96af5c9e0bf02200f501cee22e7a268af40b555d15a8237c9f36ad67ef1841daf9f6a0267b1e6df",
6758                                   "3045022100e57e46234f8782d3ff7aa593b4f7446fb5316c842e693dc63ee324fd49f6a1c302204a2f7b44c48bd26e1554422afae13153eb94b29d3687b733d18930615fb2db61",
6759                                   "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" },
6760
6761                                   { 2,
6762                                   "3045022100e3e35492e55f82ec0bc2f317ffd7a486d1f7024330fe9743c3559fc39f32ef0c02203d1d4db651fc388a91d5ad8ecdd8e83673063bc8eefe27cfd8c189090e3a23e0",
6763                                   "3044022068613fb1b98eb3aec7f44c5b115b12343c2f066c4277c82b5f873dfe68f37f50022028109b4650f3f528ca4bfe9a467aff2e3e43893b61b5159157119d5d95cf1c18",
6764                                   "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" },
6765
6766                                   { 3,
6767                                   "304402207475aeb0212ef9bf5130b60937817ad88c9a87976988ef1f323f026148cc4a850220739fea17ad3257dcad72e509c73eebe86bee30b178467b9fdab213d631b109df",
6768                                   "3045022100d315522e09e7d53d2a659a79cb67fef56d6c4bddf3f46df6772d0d20a7beb7c8022070bcc17e288607b6a72be0bd83368bb6d53488db266c1cdb4d72214e4f02ac33",
6769                                   "02000000000101adbe717a63fb658add30ada1e6e12ed257637581898abe475c11d7bbcd65bd4d03000000000000000001f2090000000000002200204adb4e2f00643db396dd120d4e7dc17625f5f2c11a40d857accc862d6b7dd80e050047304402207475aeb0212ef9bf5130b60937817ad88c9a87976988ef1f323f026148cc4a850220739fea17ad3257dcad72e509c73eebe86bee30b178467b9fdab213d631b109df01483045022100d315522e09e7d53d2a659a79cb67fef56d6c4bddf3f46df6772d0d20a7beb7c8022070bcc17e288607b6a72be0bd83368bb6d53488db266c1cdb4d72214e4f02ac33012004040404040404040404040404040404040404040404040404040404040404048a76a91414011f7254d96b819c76986c277d115efce6f7b58763ac67210394854aa6eab5b2a8122cc726e9dded053a2184d88256816826d6231c068d4a5b7c8201208763a91418bc1a114ccf9c052d3d23e28d3b0a9d1227434288527c21030d417a46946384f88d5f3337267c5e579765875dc4daca813e21734b140639e752ae677502f801b175ac686800000000" }
6770                 } );
6771
6772                 // commitment tx with five outputs untrimmed (minimum feerate)
6773                 chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
6774                 chan.feerate_per_kw = 2070;
6775
6776                 test_commitment!("304402204ca1ba260dee913d318271d86e10ca0f5883026fb5653155cff600fb40895223022037b145204b7054a40e08bb1fefbd826f827b40838d3e501423bcc57924bcb50c",
6777                                  "3044022001014419b5ba00e083ac4e0a85f19afc848aacac2d483b4b525d15e2ae5adbfe022015ebddad6ee1e72b47cb09f3e78459da5be01ccccd95dceca0e056a00cc773c1",
6778                                  "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", {
6779
6780                                   { 0,
6781                                   "304402205f6b6d12d8d2529fb24f4445630566cf4abbd0f9330ab6c2bdb94222d6a2a0c502202f556258ae6f05b193749e4c541dfcc13b525a5422f6291f073f15617ba8579b",
6782                                   "30440220150b11069454da70caf2492ded9e0065c9a57f25ac2a4c52657b1d15b6c6ed85022068a38833b603c8892717206383611bad210f1cbb4b1f87ea29c6c65b9e1cb3e5",
6783                                   "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" },
6784
6785                                   { 1,
6786                                   "3045022100f960dfb1c9aee7ce1437efa65b523e399383e8149790e05d8fed27ff6e42fe0002202fe8613e062ffe0b0c518cc4101fba1c6de70f64a5bcc7ae663f2efae43b8546",
6787                                   "30450221009a6ed18e6873bc3644332a6ee21c152a5b102821865350df7a8c74451a51f9f2022050d801fb4895d7d7fbf452824c0168347f5c0cbe821cf6a97a63af5b8b2563c6",
6788                                   "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" },
6789
6790                                   { 2,
6791                                   "3045022100ae5fc7717ae684bc1fcf9020854e5dbe9842c9e7472879ac06ff95ac2bb10e4e022057728ada4c00083a3e65493fb5d50a232165948a1a0f530ef63185c2c8c56504",
6792                                   "30440220408ad3009827a8fccf774cb285587686bfb2ed041f89a89453c311ce9c8ee0f902203c7392d9f8306d3a46522a66bd2723a7eb2628cb2d9b34d4c104f1766bf37502",
6793                                   "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" }
6794                 } );
6795
6796                 // commitment tx with five outputs untrimmed (maximum feerate)
6797                 chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
6798                 chan.feerate_per_kw = 2194;
6799
6800                 test_commitment!("304402204bb3d6e279d71d9da414c82de42f1f954267c762b2e2eb8b76bc3be4ea07d4b0022014febc009c5edc8c3fc5d94015de163200f780046f1c293bfed8568f08b70fb3",
6801                                  "3044022072c2e2b1c899b2242656a537dde2892fa3801be0d6df0a87836c550137acde8302201654aa1974d37a829083c3ba15088689f30b56d6a4f6cb14c7bad0ee3116d398",
6802                                  "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", {
6803
6804                                   { 0,
6805                                   "3045022100939726680351a7856c1bc386d4a1f422c7d29bd7b56afc139570f508474e6c40022023175a799ccf44c017fbaadb924c40b2a12115a5b7d0dfd3228df803a2de8450",
6806                                   "304502210099c98c2edeeee6ec0fb5f3bea8b79bb016a2717afa9b5072370f34382de281d302206f5e2980a995e045cf90a547f0752a7ee99d48547bc135258fe7bc07e0154301",
6807                                   "02000000000101153cd825fdb3aa624bfe513e8031d5d08c5e582fb3d1d1fe8faf27d3eed410cd0000000000000000000122020000000000002200204adb4e2f00643db396dd120d4e7dc17625f5f2c11a40d857accc862d6b7dd80e0500483045022100939726680351a7856c1bc386d4a1f422c7d29bd7b56afc139570f508474e6c40022023175a799ccf44c017fbaadb924c40b2a12115a5b7d0dfd3228df803a2de84500148304502210099c98c2edeeee6ec0fb5f3bea8b79bb016a2717afa9b5072370f34382de281d302206f5e2980a995e045cf90a547f0752a7ee99d48547bc135258fe7bc07e015430101008576a91414011f7254d96b819c76986c277d115efce6f7b58763ac67210394854aa6eab5b2a8122cc726e9dded053a2184d88256816826d6231c068d4a5b7c820120876475527c21030d417a46946384f88d5f3337267c5e579765875dc4daca813e21734b140639e752ae67a914b43e1b38138a41b37f7cd9a1d274bc63e3a9b5d188ac6868f6010000" },
6808
6809                                   { 1,
6810                                   "3044022021bb883bf324553d085ba2e821cad80c28ef8b303dbead8f98e548783c02d1600220638f9ef2a9bba25869afc923f4b5dc38be3bb459f9efa5d869392d5f7779a4a0",
6811                                   "3045022100fd85bd7697b89c08ec12acc8ba89b23090637d83abd26ca37e01ae93e67c367302202b551fe69386116c47f984aab9c8dfd25d864dcde5d3389cfbef2447a85c4b77",
6812                                   "02000000000101153cd825fdb3aa624bfe513e8031d5d08c5e582fb3d1d1fe8faf27d3eed410cd010000000000000000010a060000000000002200204adb4e2f00643db396dd120d4e7dc17625f5f2c11a40d857accc862d6b7dd80e0500473044022021bb883bf324553d085ba2e821cad80c28ef8b303dbead8f98e548783c02d1600220638f9ef2a9bba25869afc923f4b5dc38be3bb459f9efa5d869392d5f7779a4a001483045022100fd85bd7697b89c08ec12acc8ba89b23090637d83abd26ca37e01ae93e67c367302202b551fe69386116c47f984aab9c8dfd25d864dcde5d3389cfbef2447a85c4b7701008576a91414011f7254d96b819c76986c277d115efce6f7b58763ac67210394854aa6eab5b2a8122cc726e9dded053a2184d88256816826d6231c068d4a5b7c820120876475527c21030d417a46946384f88d5f3337267c5e579765875dc4daca813e21734b140639e752ae67a9148a486ff2e31d6158bf39e2608864d63fefd09d5b88ac6868f7010000" },
6813
6814                                   { 2,
6815                                   "3045022100c9e6f0454aa598b905a35e641a70cc9f67b5f38cc4b00843a041238c4a9f1c4a0220260a2822a62da97e44583e837245995ca2e36781769c52f19e498efbdcca262b",
6816                                   "30450221008a9f2ea24cd455c2b64c1472a5fa83865b0a5f49a62b661801e884cf2849af8302204d44180e50bf6adfcf1c1e581d75af91aba4e28681ce4a5ee5f3cbf65eca10f3",
6817                                   "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" }
6818                 } );
6819
6820                 // commitment tx with four outputs untrimmed (minimum feerate)
6821                 chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
6822                 chan.feerate_per_kw = 2195;
6823
6824                 test_commitment!("304402201a8c1b1f9671cd9e46c7323a104d7047cc48d3ee80d40d4512e0c72b8dc65666022066d7f9a2ce18c9eb22d2739ffcce05721c767f9b607622a31b6ea5793ddce403",
6825                                  "3044022044d592025b610c0d678f65032e87035cdfe89d1598c522cc32524ae8172417c30220749fef9d5b2ae8cdd91ece442ba8809bc891efedae2291e578475f97715d1767",
6826                                  "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", {
6827
6828                                   { 0,
6829                                   "3045022100e57b845066a06ee7c2cbfc29eabffe52daa9bf6f6de760066d04df9f9b250e0002202ffb197f0e6e0a77a75a9aff27014bd3de83b7f748d7efef986abe655e1dd50e",
6830                                   "3045022100ecc8c6529d0b2316d046f0f0757c1e1c25a636db168ec4f3aa1b9278df685dc0022067ae6b65e936f1337091f7b18a15935b608c5f2cdddb2f892ed0babfdd376d76",
6831                                   "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" },
6832
6833                                   { 1,
6834                                   "3045022100d193b7ecccad8057571620a0b1ffa6c48e9483311723b59cf536043b20bc51550220546d4bd37b3b101ecda14f6c907af46ec391abce1cd9c7ce22b1a62b534f2f2a",
6835                                   "3044022014d66f11f9cacf923807eba49542076c5fe5cccf252fb08fe98c78ef3ca6ab5402201b290dbe043cc512d9d78de074a5a129b8759bc6a6c546b190d120b690bd6e82",
6836                                   "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" }
6837                 } );
6838
6839                 // commitment tx with four outputs untrimmed (maximum feerate)
6840                 chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
6841                 chan.feerate_per_kw = 3702;
6842
6843                 test_commitment!("304502210092a587aeb777f869e7ff0d7898ea619ee26a3dacd1f3672b945eea600be431100220077ee9eae3528d15251f2a52b607b189820e57a6ccfac8d1af502b132ee40169",
6844                                  "3045022100e5efb73c32d32da2d79702299b6317de6fb24a60476e3855926d78484dd1b3c802203557cb66a42c944ef06e00bcc4da35a5bcb2f185aab0f8e403e519e1d66aaf75",
6845                                  "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", {
6846
6847                                   { 0,
6848                                   "304402206fa54c11f98c3bae1e93df43fc7affeb05b476bf8060c03e29c377c69bc08e8b0220672701cce50d5c379ff45a5d2cfe48ac44973adb066ac32608e21221d869bb89",
6849                                   "304402206e36c683ebf2cb16bcef3d5439cf8b53cd97280a365ed8acd7abb85a8ba5f21c02206e8621edfc2a5766cbc96eb67fd501127ff163eb6b85518a39f7d4974aef126f",
6850                                   "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" },
6851
6852                                   { 1,
6853                                   "3044022057649739b0eb74d541ead0dfdb3d4b2c15aa192720031044c3434c67812e5ca902201e5ede42d960ae551707f4a6b34b09393cf4dee2418507daa022e3550dbb5817",
6854                                   "304402207faad26678c8850e01b4a0696d60841f7305e1832b786110ee9075cb92ed14a30220516ef8ee5dfa80824ea28cbcec0dd95f8b847146257c16960db98507db15ffdc",
6855                                   "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" }
6856                 } );
6857
6858                 // commitment tx with three outputs untrimmed (minimum feerate)
6859                 chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
6860                 chan.feerate_per_kw = 3703;
6861
6862                 test_commitment!("3045022100b495d239772a237ff2cf354b1b11be152fd852704cb184e7356d13f2fb1e5e430220723db5cdb9cbd6ead7bfd3deb419cf41053a932418cbb22a67b581f40bc1f13e",
6863                                  "304402201b736d1773a124c745586217a75bed5f66c05716fbe8c7db4fdb3c3069741cdd02205083f39c321c1bcadfc8d97e3c791a66273d936abac0c6a2fde2ed46019508e1",
6864                                  "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", {
6865
6866                                   { 0,
6867                                   "3045022100c34c61735f93f2e324cc873c3b248111ccf8f6db15d5969583757010d4ad2b4602207867bb919b2ddd6387873e425345c9b7fd18d1d66aba41f3607bc2896ef3c30a",
6868                                   "3045022100988c143e2110067117d2321bdd4bd16ca1734c98b29290d129384af0962b634e02206c1b02478878c5f547018b833986578f90c3e9be669fe5788ad0072a55acbb05",
6869                                   "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" }
6870                 } );
6871
6872                 // commitment tx with three outputs untrimmed (maximum feerate)
6873                 chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
6874                 chan.feerate_per_kw = 4914;
6875
6876                 test_commitment!("3045022100b4b16d5f8cc9fc4c1aff48831e832a0d8990e133978a66e302c133550954a44d022073573ce127e2200d316f6b612803a5c0c97b8d20e1e44dbe2ac0dd2fb8c95244",
6877                                  "3045022100d72638bc6308b88bb6d45861aae83e5b9ff6e10986546e13bce769c70036e2620220320be7c6d66d22f30b9fcd52af66531505b1310ca3b848c19285b38d8a1a8c19",
6878                                  "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", {
6879
6880                                   { 0,
6881                                   "3045022100f43591c156038ba217756006bb3c55f7d113a325cdd7d9303c82115372858d68022016355b5aadf222bc8d12e426c75f4a03423917b2443a103eb2a498a3a2234374",
6882                                   "30440220585dee80fafa264beac535c3c0bb5838ac348b156fdc982f86adc08dfc9bfd250220130abb82f9f295cc9ef423dcfef772fde2acd85d9df48cc538981d26a10a9c10",
6883                                   "02000000000101a9172908eace869cc35128c31fc2ab502f72e4dff31aab23e0244c4b04b11ab00000000000000000000122020000000000002200204adb4e2f00643db396dd120d4e7dc17625f5f2c11a40d857accc862d6b7dd80e0500483045022100f43591c156038ba217756006bb3c55f7d113a325cdd7d9303c82115372858d68022016355b5aadf222bc8d12e426c75f4a03423917b2443a103eb2a498a3a2234374014730440220585dee80fafa264beac535c3c0bb5838ac348b156fdc982f86adc08dfc9bfd250220130abb82f9f295cc9ef423dcfef772fde2acd85d9df48cc538981d26a10a9c10012004040404040404040404040404040404040404040404040404040404040404048a76a91414011f7254d96b819c76986c277d115efce6f7b58763ac67210394854aa6eab5b2a8122cc726e9dded053a2184d88256816826d6231c068d4a5b7c8201208763a91418bc1a114ccf9c052d3d23e28d3b0a9d1227434288527c21030d417a46946384f88d5f3337267c5e579765875dc4daca813e21734b140639e752ae677502f801b175ac686800000000" }
6884                 } );
6885
6886                 // commitment tx with two outputs untrimmed (minimum feerate)
6887                 chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
6888                 chan.feerate_per_kw = 4915;
6889
6890                 test_commitment!("304402203a286936e74870ca1459c700c71202af0381910a6bfab687ef494ef1bc3e02c902202506c362d0e3bee15e802aa729bf378e051644648253513f1c085b264cc2a720",
6891                                  "30450221008a953551f4d67cb4df3037207fc082ddaf6be84d417b0bd14c80aab66f1b01a402207508796dc75034b2dee876fe01dc05a08b019f3e5d689ac8842ade2f1befccf5",
6892                                  "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", {});
6893
6894                 // commitment tx with two outputs untrimmed (maximum feerate)
6895                 chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
6896                 chan.feerate_per_kw = 9651180;
6897
6898                 test_commitment!("304402200a8544eba1d216f5c5e530597665fa9bec56943c0f66d98fc3d028df52d84f7002201e45fa5c6bc3a506cc2553e7d1c0043a9811313fc39c954692c0d47cfce2bbd3",
6899                                  "3045022100e11b638c05c650c2f63a421d36ef8756c5ce82f2184278643520311cdf50aa200220259565fb9c8e4a87ccaf17f27a3b9ca4f20625754a0920d9c6c239d8156a11de",
6900                                  "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", {});
6901
6902                 // commitment tx with one output untrimmed (minimum feerate)
6903                 chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
6904                 chan.feerate_per_kw = 9651181;
6905
6906                 test_commitment!("304402202ade0142008309eb376736575ad58d03e5b115499709c6db0b46e36ff394b492022037b63d78d66404d6504d4c4ac13be346f3d1802928a6d3ad95a6a944227161a2",
6907                                  "304402207e8d51e0c570a5868a78414f4e0cbfaed1106b171b9581542c30718ee4eb95ba02203af84194c97adf98898c9afe2f2ed4a7f8dba05a2dfab28ac9d9c604aa49a379",
6908                                  "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", {});
6909
6910                 // commitment tx with fee greater than funder amount
6911                 chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
6912                 chan.feerate_per_kw = 9651936;
6913
6914                 test_commitment!("304402202ade0142008309eb376736575ad58d03e5b115499709c6db0b46e36ff394b492022037b63d78d66404d6504d4c4ac13be346f3d1802928a6d3ad95a6a944227161a2",
6915                                  "304402207e8d51e0c570a5868a78414f4e0cbfaed1106b171b9581542c30718ee4eb95ba02203af84194c97adf98898c9afe2f2ed4a7f8dba05a2dfab28ac9d9c604aa49a379",
6916                                  "02000000000101bef67e4e2fb9ddeeb3461973cd4c62abb35050b1add772995b820b584a488489000000000038b02b8001c0c62d0000000000160014cc1b07838e387deacd0e5232e1e8b49f4c29e484040047304402207e8d51e0c570a5868a78414f4e0cbfaed1106b171b9581542c30718ee4eb95ba02203af84194c97adf98898c9afe2f2ed4a7f8dba05a2dfab28ac9d9c604aa49a3790147304402202ade0142008309eb376736575ad58d03e5b115499709c6db0b46e36ff394b492022037b63d78d66404d6504d4c4ac13be346f3d1802928a6d3ad95a6a944227161a201475221023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb21030e9f7b623d2ccc7c9bd44d66d5ce21ce504c0acf6385a132cec6d3c39fa711c152ae3e195220", {});
6917
6918                 // commitment tx with 3 htlc outputs, 2 offered having the same amount and preimage
6919                 chan.value_to_self_msat = 7_000_000_000 - 2_000_000;
6920                 chan.feerate_per_kw = 253;
6921                 chan.pending_inbound_htlcs.clear();
6922                 chan.pending_inbound_htlcs.push({
6923                         let mut out = InboundHTLCOutput{
6924                                 htlc_id: 1,
6925                                 amount_msat: 2000000,
6926                                 cltv_expiry: 501,
6927                                 payment_hash: PaymentHash([0; 32]),
6928                                 state: InboundHTLCState::Committed,
6929                         };
6930                         out.payment_hash.0 = Sha256::hash(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()).into_inner();
6931                         out
6932                 });
6933                 chan.pending_outbound_htlcs.clear();
6934                 chan.pending_outbound_htlcs.push({
6935                         let mut out = OutboundHTLCOutput{
6936                                 htlc_id: 6,
6937                                 amount_msat: 5000000,
6938                                 cltv_expiry: 506,
6939                                 payment_hash: PaymentHash([0; 32]),
6940                                 state: OutboundHTLCState::Committed,
6941                                 source: HTLCSource::dummy(),
6942                         };
6943                         out.payment_hash.0 = Sha256::hash(&hex::decode("0505050505050505050505050505050505050505050505050505050505050505").unwrap()).into_inner();
6944                         out
6945                 });
6946                 chan.pending_outbound_htlcs.push({
6947                         let mut out = OutboundHTLCOutput{
6948                                 htlc_id: 5,
6949                                 amount_msat: 5000000,
6950                                 cltv_expiry: 505,
6951                                 payment_hash: PaymentHash([0; 32]),
6952                                 state: OutboundHTLCState::Committed,
6953                                 source: HTLCSource::dummy(),
6954                         };
6955                         out.payment_hash.0 = Sha256::hash(&hex::decode("0505050505050505050505050505050505050505050505050505050505050505").unwrap()).into_inner();
6956                         out
6957                 });
6958
6959                 test_commitment!("30440220048705bec5288d28b3f29344b8d124853b1af423a568664d2c6f02c8ea886525022060f998a461052a2476b912db426ea2a06700953a241135c7957f2e79bc222df9",
6960                                  "3045022100c4f1d60b6fca9febc8b39de1a31e84c5f7c4b41c97239ef05f4350aa484c6b5e02200c5134ac8b20eb7a29d0dd4a501f6aa8fefb8489171f4cb408bd2a32324ab03f",
6961                                  "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", {
6962
6963                                   { 0,
6964                                   "304502210081cbb94121761d34c189cd4e6a281feea6f585060ad0ba2632e8d6b3c6bb8a6c02201007981bbd16539d63df2805b5568f1f5688cd2a885d04706f50db9b77ba13c6",
6965                                   "304502210090ed76aeb21b53236a598968abc66e2024691d07b62f53ddbeca8f93144af9c602205f873af5a0c10e62690e9aba09740550f194a9dc455ba4c1c23f6cde7704674c",
6966                                   "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" },
6967                                   { 1,
6968                                   "304402201d0f09d2bf7bc245a4f17980e1e9164290df16c70c6a2ff1592f5030d6108581022061e744a7dc151b36bf0aff7a4f1812ba90b8b03633bb979a270d19858fd960c5",
6969                                   "30450221009aef000d2e843a4202c1b1a2bf554abc9a7902bf49b2cb0759bc507456b7ebad02204e7c3d193ede2fd2b4cd6b39f51a920e581e35575e357e44d7b699c40ce61d39",
6970                                   "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" },
6971                                   { 2,
6972                                   "30440220010bf035d5823596e50dce2076a4d9f942d8d28031c9c428b901a02b6b8140de02203250e8e4a08bc5b4ecdca4d0eedf98223e02e3ac1c0206b3a7ffdb374aa21e5f",
6973                                   "30440220073de0067b88e425b3018b30366bfeda0ccb703118ccd3d02ead08c0f53511d002203fac50ac0e4cf8a3af0b4b1b12e801650591f748f8ddf1e089c160f10b69e511",
6974                                   "0200000000010189a326e23addc28323dbadcb4e71c2c17088b6e8fa184103e552f44075dddc3402000000000000000001e1120000000000002200204adb4e2f00643db396dd120d4e7dc17625f5f2c11a40d857accc862d6b7dd80e05004730440220010bf035d5823596e50dce2076a4d9f942d8d28031c9c428b901a02b6b8140de02203250e8e4a08bc5b4ecdca4d0eedf98223e02e3ac1c0206b3a7ffdb374aa21e5f014730440220073de0067b88e425b3018b30366bfeda0ccb703118ccd3d02ead08c0f53511d002203fac50ac0e4cf8a3af0b4b1b12e801650591f748f8ddf1e089c160f10b69e51101008576a91414011f7254d96b819c76986c277d115efce6f7b58763ac67210394854aa6eab5b2a8122cc726e9dded053a2184d88256816826d6231c068d4a5b7c820120876475527c21030d417a46946384f88d5f3337267c5e579765875dc4daca813e21734b140639e752ae67a9142002cc93ebefbb1b73f0af055dcc27a0b504ad7688ac6868fa010000" }
6975                 } );
6976         }
6977
6978         #[test]
6979         fn test_per_commitment_secret_gen() {
6980                 // Test vectors from BOLT 3 Appendix D:
6981
6982                 let mut seed = [0; 32];
6983                 seed[0..32].clone_from_slice(&hex::decode("0000000000000000000000000000000000000000000000000000000000000000").unwrap());
6984                 assert_eq!(chan_utils::build_commitment_secret(&seed, 281474976710655),
6985                            hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap()[..]);
6986
6987                 seed[0..32].clone_from_slice(&hex::decode("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF").unwrap());
6988                 assert_eq!(chan_utils::build_commitment_secret(&seed, 281474976710655),
6989                            hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap()[..]);
6990
6991                 assert_eq!(chan_utils::build_commitment_secret(&seed, 0xaaaaaaaaaaa),
6992                            hex::decode("56f4008fb007ca9acf0e15b054d5c9fd12ee06cea347914ddbaed70d1c13a528").unwrap()[..]);
6993
6994                 assert_eq!(chan_utils::build_commitment_secret(&seed, 0x555555555555),
6995                            hex::decode("9015daaeb06dba4ccc05b91b2f73bd54405f2be9f217fbacd3c5ac2e62327d31").unwrap()[..]);
6996
6997                 seed[0..32].clone_from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap());
6998                 assert_eq!(chan_utils::build_commitment_secret(&seed, 1),
6999                            hex::decode("915c75942a26bb3a433a8ce2cb0427c29ec6c1775cfc78328b57f6ba7bfeaa9c").unwrap()[..]);
7000         }
7001
7002         #[test]
7003         fn test_key_derivation() {
7004                 // Test vectors from BOLT 3 Appendix E:
7005                 let secp_ctx = Secp256k1::new();
7006
7007                 let base_secret = SecretKey::from_slice(&hex::decode("000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f").unwrap()[..]).unwrap();
7008                 let per_commitment_secret = SecretKey::from_slice(&hex::decode("1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100").unwrap()[..]).unwrap();
7009
7010                 let base_point = PublicKey::from_secret_key(&secp_ctx, &base_secret);
7011                 assert_eq!(base_point.serialize()[..], hex::decode("036d6caac248af96f6afa7f904f550253a0f3ef3f5aa2fe6838a95b216691468e2").unwrap()[..]);
7012
7013                 let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret);
7014                 assert_eq!(per_commitment_point.serialize()[..], hex::decode("025f7117a78150fe2ef97db7cfc83bd57b2e2c0d0dd25eaf467a4a1c2a45ce1486").unwrap()[..]);
7015
7016                 assert_eq!(chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &base_point).unwrap().serialize()[..],
7017                                 hex::decode("0235f2dbfaa89b57ec7b055afe29849ef7ddfeb1cefdb9ebdc43f5494984db29e5").unwrap()[..]);
7018
7019                 assert_eq!(chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &base_secret).unwrap(),
7020                                 SecretKey::from_slice(&hex::decode("cbced912d3b21bf196a766651e436aff192362621ce317704ea2f75d87e7be0f").unwrap()[..]).unwrap());
7021
7022                 assert_eq!(chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &base_point).unwrap().serialize()[..],
7023                                 hex::decode("02916e326636d19c33f13e8c0c3a03dd157f332f3e99c317c141dd865eb01f8ff0").unwrap()[..]);
7024
7025                 assert_eq!(chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_secret, &base_secret).unwrap(),
7026                                 SecretKey::from_slice(&hex::decode("d09ffff62ddb2297ab000cc85bcb4283fdeb6aa052affbc9dddcf33b61078110").unwrap()[..]).unwrap());
7027         }
7028 }