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Use CLOSED_CHANNEL_UPDATE_ID in force closing ChannelMonitorUpdates
[rust-lightning] / lightning / src / chain / channelmonitor.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 //! The logic to monitor for on-chain transactions and create the relevant claim responses lives
11 //! here.
12 //!
13 //! ChannelMonitor objects are generated by ChannelManager in response to relevant
14 //! messages/actions, and MUST be persisted to disk (and, preferably, remotely) before progress can
15 //! be made in responding to certain messages, see [`chain::Watch`] for more.
16 //!
17 //! Note that ChannelMonitors are an important part of the lightning trust model and a copy of the
18 //! latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date
19 //! ChannelMonitors should do so). Thus, if you're building rust-lightning into an HSM or other
20 //! security-domain-separated system design, you should consider having multiple paths for
21 //! ChannelMonitors to get out of the HSM and onto monitoring devices.
22
23 use bitcoin::blockdata::block::BlockHeader;
24 use bitcoin::blockdata::transaction::{OutPoint as BitcoinOutPoint, TxOut, Transaction};
25 use bitcoin::blockdata::script::{Script, Builder};
26 use bitcoin::blockdata::opcodes;
27
28 use bitcoin::hashes::Hash;
29 use bitcoin::hashes::sha256::Hash as Sha256;
30 use bitcoin::hash_types::{Txid, BlockHash, WPubkeyHash};
31
32 use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature};
33 use bitcoin::secp256k1::{SecretKey, PublicKey};
34 use bitcoin::secp256k1;
35
36 use crate::ln::{PaymentHash, PaymentPreimage};
37 use crate::ln::msgs::DecodeError;
38 use crate::ln::chan_utils;
39 use crate::ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, HTLCClaim, ChannelTransactionParameters, HolderCommitmentTransaction};
40 use crate::ln::channelmanager::{HTLCSource, SentHTLCId};
41 use crate::chain;
42 use crate::chain::{BestBlock, WatchedOutput};
43 use crate::chain::chaininterface::{BroadcasterInterface, FeeEstimator, LowerBoundedFeeEstimator};
44 use crate::chain::transaction::{OutPoint, TransactionData};
45 use crate::chain::keysinterface::{SpendableOutputDescriptor, StaticPaymentOutputDescriptor, DelayedPaymentOutputDescriptor, WriteableEcdsaChannelSigner, SignerProvider, EntropySource};
46 #[cfg(anchors)]
47 use crate::chain::onchaintx::ClaimEvent;
48 use crate::chain::onchaintx::OnchainTxHandler;
49 use crate::chain::package::{CounterpartyOfferedHTLCOutput, CounterpartyReceivedHTLCOutput, HolderFundingOutput, HolderHTLCOutput, PackageSolvingData, PackageTemplate, RevokedOutput, RevokedHTLCOutput};
50 use crate::chain::Filter;
51 use crate::util::logger::Logger;
52 use crate::util::ser::{Readable, ReadableArgs, RequiredWrapper, MaybeReadable, UpgradableRequired, Writer, Writeable, U48};
53 use crate::util::byte_utils;
54 use crate::util::events::Event;
55 #[cfg(anchors)]
56 use crate::util::events::{AnchorDescriptor, HTLCDescriptor, BumpTransactionEvent};
57
58 use crate::prelude::*;
59 use core::{cmp, mem};
60 use crate::io::{self, Error};
61 use core::convert::TryInto;
62 use core::ops::Deref;
63 use crate::sync::{Mutex, LockTestExt};
64
65 /// An update generated by the underlying channel itself which contains some new information the
66 /// [`ChannelMonitor`] should be made aware of.
67 ///
68 /// Because this represents only a small number of updates to the underlying state, it is generally
69 /// much smaller than a full [`ChannelMonitor`]. However, for large single commitment transaction
70 /// updates (e.g. ones during which there are hundreds of HTLCs pending on the commitment
71 /// transaction), a single update may reach upwards of 1 MiB in serialized size.
72 #[cfg_attr(any(test, fuzzing, feature = "_test_utils"), derive(PartialEq, Eq))]
73 #[derive(Clone)]
74 #[must_use]
75 pub struct ChannelMonitorUpdate {
76         pub(crate) updates: Vec<ChannelMonitorUpdateStep>,
77         /// The sequence number of this update. Updates *must* be replayed in-order according to this
78         /// sequence number (and updates may panic if they are not). The update_id values are strictly
79         /// increasing and increase by one for each new update, with two exceptions specified below.
80         ///
81         /// This sequence number is also used to track up to which points updates which returned
82         /// [`ChannelMonitorUpdateStatus::InProgress`] have been applied to all copies of a given
83         /// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
84         ///
85         /// The only instances we allow where update_id values are not strictly increasing have a
86         /// special update ID of [`CLOSED_CHANNEL_UPDATE_ID`]. This update ID is used for updates that
87         /// will force close the channel by broadcasting the latest commitment transaction or
88         /// special post-force-close updates, like providing preimages necessary to claim outputs on the
89         /// broadcast commitment transaction. See its docs for more details.
90         ///
91         /// [`ChannelMonitorUpdateStatus::InProgress`]: super::ChannelMonitorUpdateStatus::InProgress
92         pub update_id: u64,
93 }
94
95 /// The update ID used for a [`ChannelMonitorUpdate`] that is either:
96 ///
97 ///     (1) attempting to force close the channel by broadcasting our latest commitment transaction or
98 ///     (2) providing a preimage (after the channel has been force closed) from a forward link that
99 ///             allows us to spend an HTLC output on this channel's (the backward link's) broadcasted
100 ///             commitment transaction.
101 ///
102 /// No other [`ChannelMonitorUpdate`]s are allowed after force-close.
103 pub const CLOSED_CHANNEL_UPDATE_ID: u64 = core::u64::MAX;
104
105 impl Writeable for ChannelMonitorUpdate {
106         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
107                 write_ver_prefix!(w, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
108                 self.update_id.write(w)?;
109                 (self.updates.len() as u64).write(w)?;
110                 for update_step in self.updates.iter() {
111                         update_step.write(w)?;
112                 }
113                 write_tlv_fields!(w, {});
114                 Ok(())
115         }
116 }
117 impl Readable for ChannelMonitorUpdate {
118         fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
119                 let _ver = read_ver_prefix!(r, SERIALIZATION_VERSION);
120                 let update_id: u64 = Readable::read(r)?;
121                 let len: u64 = Readable::read(r)?;
122                 let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::core::mem::size_of::<ChannelMonitorUpdateStep>()));
123                 for _ in 0..len {
124                         if let Some(upd) = MaybeReadable::read(r)? {
125                                 updates.push(upd);
126                         }
127                 }
128                 read_tlv_fields!(r, {});
129                 Ok(Self { update_id, updates })
130         }
131 }
132
133 /// An event to be processed by the ChannelManager.
134 #[derive(Clone, PartialEq, Eq)]
135 pub enum MonitorEvent {
136         /// A monitor event containing an HTLCUpdate.
137         HTLCEvent(HTLCUpdate),
138
139         /// A monitor event that the Channel's commitment transaction was confirmed.
140         CommitmentTxConfirmed(OutPoint),
141
142         /// Indicates a [`ChannelMonitor`] update has completed. See
143         /// [`ChannelMonitorUpdateStatus::InProgress`] for more information on how this is used.
144         ///
145         /// [`ChannelMonitorUpdateStatus::InProgress`]: super::ChannelMonitorUpdateStatus::InProgress
146         Completed {
147                 /// The funding outpoint of the [`ChannelMonitor`] that was updated
148                 funding_txo: OutPoint,
149                 /// The Update ID from [`ChannelMonitorUpdate::update_id`] which was applied or
150                 /// [`ChannelMonitor::get_latest_update_id`].
151                 ///
152                 /// Note that this should only be set to a given update's ID if all previous updates for the
153                 /// same [`ChannelMonitor`] have been applied and persisted.
154                 monitor_update_id: u64,
155         },
156
157         /// Indicates a [`ChannelMonitor`] update has failed. See
158         /// [`ChannelMonitorUpdateStatus::PermanentFailure`] for more information on how this is used.
159         ///
160         /// [`ChannelMonitorUpdateStatus::PermanentFailure`]: super::ChannelMonitorUpdateStatus::PermanentFailure
161         UpdateFailed(OutPoint),
162 }
163 impl_writeable_tlv_based_enum_upgradable!(MonitorEvent,
164         // Note that Completed and UpdateFailed are currently never serialized to disk as they are
165         // generated only in ChainMonitor
166         (0, Completed) => {
167                 (0, funding_txo, required),
168                 (2, monitor_update_id, required),
169         },
170 ;
171         (2, HTLCEvent),
172         (4, CommitmentTxConfirmed),
173         (6, UpdateFailed),
174 );
175
176 /// Simple structure sent back by `chain::Watch` when an HTLC from a forward channel is detected on
177 /// chain. Used to update the corresponding HTLC in the backward channel. Failing to pass the
178 /// preimage claim backward will lead to loss of funds.
179 #[derive(Clone, PartialEq, Eq)]
180 pub struct HTLCUpdate {
181         pub(crate) payment_hash: PaymentHash,
182         pub(crate) payment_preimage: Option<PaymentPreimage>,
183         pub(crate) source: HTLCSource,
184         pub(crate) htlc_value_satoshis: Option<u64>,
185 }
186 impl_writeable_tlv_based!(HTLCUpdate, {
187         (0, payment_hash, required),
188         (1, htlc_value_satoshis, option),
189         (2, source, required),
190         (4, payment_preimage, option),
191 });
192
193 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
194 /// instead claiming it in its own individual transaction.
195 pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
196 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
197 /// HTLC-Success transaction.
198 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
199 /// transaction confirmed (and we use it in a few more, equivalent, places).
200 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 18;
201 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
202 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
203 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
204 /// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
205 /// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
206 /// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
207 /// due to expiration but increase the cost of funds being locked longuer in case of failure.
208 /// This delay also cover a low-power peer being slow to process blocks and so being behind us on
209 /// accurate block height.
210 /// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
211 /// with at worst this delay, so we are not only using this value as a mercy for them but also
212 /// us as a safeguard to delay with enough time.
213 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
214 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding
215 /// inbound HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us
216 /// losing money.
217 ///
218 /// Note that this is a library-wide security assumption. If a reorg deeper than this number of
219 /// blocks occurs, counterparties may be able to steal funds or claims made by and balances exposed
220 /// by a  [`ChannelMonitor`] may be incorrect.
221 // We also use this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
222 // It may cause spurious generation of bumped claim txn but that's alright given the outpoint is already
223 // solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
224 // keep bumping another claim tx to solve the outpoint.
225 pub const ANTI_REORG_DELAY: u32 = 6;
226 /// Number of blocks before confirmation at which we fail back an un-relayed HTLC or at which we
227 /// refuse to accept a new HTLC.
228 ///
229 /// This is used for a few separate purposes:
230 /// 1) if we've received an MPP HTLC to us and it expires within this many blocks and we are
231 ///    waiting on additional parts (or waiting on the preimage for any HTLC from the user), we will
232 ///    fail this HTLC,
233 /// 2) if we receive an HTLC within this many blocks of its expiry (plus one to avoid a race
234 ///    condition with the above), we will fail this HTLC without telling the user we received it,
235 ///
236 /// (1) is all about protecting us - we need enough time to update the channel state before we hit
237 /// CLTV_CLAIM_BUFFER, at which point we'd go on chain to claim the HTLC with the preimage.
238 ///
239 /// (2) is the same, but with an additional buffer to avoid accepting an HTLC which is immediately
240 /// in a race condition between the user connecting a block (which would fail it) and the user
241 /// providing us the preimage (which would claim it).
242 pub(crate) const HTLC_FAIL_BACK_BUFFER: u32 = CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS;
243
244 // TODO(devrandom) replace this with HolderCommitmentTransaction
245 #[derive(Clone, PartialEq, Eq)]
246 struct HolderSignedTx {
247         /// txid of the transaction in tx, just used to make comparison faster
248         txid: Txid,
249         revocation_key: PublicKey,
250         a_htlc_key: PublicKey,
251         b_htlc_key: PublicKey,
252         delayed_payment_key: PublicKey,
253         per_commitment_point: PublicKey,
254         htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
255         to_self_value_sat: u64,
256         feerate_per_kw: u32,
257 }
258 impl_writeable_tlv_based!(HolderSignedTx, {
259         (0, txid, required),
260         // Note that this is filled in with data from OnchainTxHandler if it's missing.
261         // For HolderSignedTx objects serialized with 0.0.100+, this should be filled in.
262         (1, to_self_value_sat, (default_value, u64::max_value())),
263         (2, revocation_key, required),
264         (4, a_htlc_key, required),
265         (6, b_htlc_key, required),
266         (8, delayed_payment_key, required),
267         (10, per_commitment_point, required),
268         (12, feerate_per_kw, required),
269         (14, htlc_outputs, vec_type)
270 });
271
272 #[cfg(anchors)]
273 impl HolderSignedTx {
274         fn non_dust_htlcs(&self) -> Vec<HTLCOutputInCommitment> {
275                 self.htlc_outputs.iter().filter_map(|(htlc, _, _)| {
276                         if let Some(_) = htlc.transaction_output_index {
277                                 Some(htlc.clone())
278                         } else {
279                                 None
280                         }
281                 })
282                 .collect()
283         }
284 }
285
286 /// We use this to track static counterparty commitment transaction data and to generate any
287 /// justice or 2nd-stage preimage/timeout transactions.
288 #[derive(PartialEq, Eq)]
289 struct CounterpartyCommitmentParameters {
290         counterparty_delayed_payment_base_key: PublicKey,
291         counterparty_htlc_base_key: PublicKey,
292         on_counterparty_tx_csv: u16,
293 }
294
295 impl Writeable for CounterpartyCommitmentParameters {
296         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
297                 w.write_all(&(0 as u64).to_be_bytes())?;
298                 write_tlv_fields!(w, {
299                         (0, self.counterparty_delayed_payment_base_key, required),
300                         (2, self.counterparty_htlc_base_key, required),
301                         (4, self.on_counterparty_tx_csv, required),
302                 });
303                 Ok(())
304         }
305 }
306 impl Readable for CounterpartyCommitmentParameters {
307         fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
308                 let counterparty_commitment_transaction = {
309                         // Versions prior to 0.0.100 had some per-HTLC state stored here, which is no longer
310                         // used. Read it for compatibility.
311                         let per_htlc_len: u64 = Readable::read(r)?;
312                         for _  in 0..per_htlc_len {
313                                 let _txid: Txid = Readable::read(r)?;
314                                 let htlcs_count: u64 = Readable::read(r)?;
315                                 for _ in 0..htlcs_count {
316                                         let _htlc: HTLCOutputInCommitment = Readable::read(r)?;
317                                 }
318                         }
319
320                         let mut counterparty_delayed_payment_base_key = RequiredWrapper(None);
321                         let mut counterparty_htlc_base_key = RequiredWrapper(None);
322                         let mut on_counterparty_tx_csv: u16 = 0;
323                         read_tlv_fields!(r, {
324                                 (0, counterparty_delayed_payment_base_key, required),
325                                 (2, counterparty_htlc_base_key, required),
326                                 (4, on_counterparty_tx_csv, required),
327                         });
328                         CounterpartyCommitmentParameters {
329                                 counterparty_delayed_payment_base_key: counterparty_delayed_payment_base_key.0.unwrap(),
330                                 counterparty_htlc_base_key: counterparty_htlc_base_key.0.unwrap(),
331                                 on_counterparty_tx_csv,
332                         }
333                 };
334                 Ok(counterparty_commitment_transaction)
335         }
336 }
337
338 /// An entry for an [`OnchainEvent`], stating the block height and hash when the event was
339 /// observed, as well as the transaction causing it.
340 ///
341 /// Used to determine when the on-chain event can be considered safe from a chain reorganization.
342 #[derive(PartialEq, Eq)]
343 struct OnchainEventEntry {
344         txid: Txid,
345         height: u32,
346         block_hash: Option<BlockHash>, // Added as optional, will be filled in for any entry generated on 0.0.113 or after
347         event: OnchainEvent,
348         transaction: Option<Transaction>, // Added as optional, but always filled in, in LDK 0.0.110
349 }
350
351 impl OnchainEventEntry {
352         fn confirmation_threshold(&self) -> u32 {
353                 let mut conf_threshold = self.height + ANTI_REORG_DELAY - 1;
354                 match self.event {
355                         OnchainEvent::MaturingOutput {
356                                 descriptor: SpendableOutputDescriptor::DelayedPaymentOutput(ref descriptor)
357                         } => {
358                                 // A CSV'd transaction is confirmable in block (input height) + CSV delay, which means
359                                 // it's broadcastable when we see the previous block.
360                                 conf_threshold = cmp::max(conf_threshold, self.height + descriptor.to_self_delay as u32 - 1);
361                         },
362                         OnchainEvent::FundingSpendConfirmation { on_local_output_csv: Some(csv), .. } |
363                         OnchainEvent::HTLCSpendConfirmation { on_to_local_output_csv: Some(csv), .. } => {
364                                 // A CSV'd transaction is confirmable in block (input height) + CSV delay, which means
365                                 // it's broadcastable when we see the previous block.
366                                 conf_threshold = cmp::max(conf_threshold, self.height + csv as u32 - 1);
367                         },
368                         _ => {},
369                 }
370                 conf_threshold
371         }
372
373         fn has_reached_confirmation_threshold(&self, best_block: &BestBlock) -> bool {
374                 best_block.height() >= self.confirmation_threshold()
375         }
376 }
377
378 /// The (output index, sats value) for the counterparty's output in a commitment transaction.
379 ///
380 /// This was added as an `Option` in 0.0.110.
381 type CommitmentTxCounterpartyOutputInfo = Option<(u32, u64)>;
382
383 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
384 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
385 #[derive(PartialEq, Eq)]
386 enum OnchainEvent {
387         /// An outbound HTLC failing after a transaction is confirmed. Used
388         ///  * when an outbound HTLC output is spent by us after the HTLC timed out
389         ///  * an outbound HTLC which was not present in the commitment transaction which appeared
390         ///    on-chain (either because it was not fully committed to or it was dust).
391         /// Note that this is *not* used for preimage claims, as those are passed upstream immediately,
392         /// appearing only as an `HTLCSpendConfirmation`, below.
393         HTLCUpdate {
394                 source: HTLCSource,
395                 payment_hash: PaymentHash,
396                 htlc_value_satoshis: Option<u64>,
397                 /// None in the second case, above, ie when there is no relevant output in the commitment
398                 /// transaction which appeared on chain.
399                 commitment_tx_output_idx: Option<u32>,
400         },
401         /// An output waiting on [`ANTI_REORG_DELAY`] confirmations before we hand the user the
402         /// [`SpendableOutputDescriptor`].
403         MaturingOutput {
404                 descriptor: SpendableOutputDescriptor,
405         },
406         /// A spend of the funding output, either a commitment transaction or a cooperative closing
407         /// transaction.
408         FundingSpendConfirmation {
409                 /// The CSV delay for the output of the funding spend transaction (implying it is a local
410                 /// commitment transaction, and this is the delay on the to_self output).
411                 on_local_output_csv: Option<u16>,
412                 /// If the funding spend transaction was a known remote commitment transaction, we track
413                 /// the output index and amount of the counterparty's `to_self` output here.
414                 ///
415                 /// This allows us to generate a [`Balance::CounterpartyRevokedOutputClaimable`] for the
416                 /// counterparty output.
417                 commitment_tx_to_counterparty_output: CommitmentTxCounterpartyOutputInfo,
418         },
419         /// A spend of a commitment transaction HTLC output, set in the cases where *no* `HTLCUpdate`
420         /// is constructed. This is used when
421         ///  * an outbound HTLC is claimed by our counterparty with a preimage, causing us to
422         ///    immediately claim the HTLC on the inbound edge and track the resolution here,
423         ///  * an inbound HTLC is claimed by our counterparty (with a timeout),
424         ///  * an inbound HTLC is claimed by us (with a preimage).
425         ///  * a revoked-state HTLC transaction was broadcasted, which was claimed by the revocation
426         ///    signature.
427         ///  * a revoked-state HTLC transaction was broadcasted, which was claimed by an
428         ///    HTLC-Success/HTLC-Failure transaction (and is still claimable with a revocation
429         ///    signature).
430         HTLCSpendConfirmation {
431                 commitment_tx_output_idx: u32,
432                 /// If the claim was made by either party with a preimage, this is filled in
433                 preimage: Option<PaymentPreimage>,
434                 /// If the claim was made by us on an inbound HTLC against a local commitment transaction,
435                 /// we set this to the output CSV value which we will have to wait until to spend the
436                 /// output (and generate a SpendableOutput event).
437                 on_to_local_output_csv: Option<u16>,
438         },
439 }
440
441 impl Writeable for OnchainEventEntry {
442         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
443                 write_tlv_fields!(writer, {
444                         (0, self.txid, required),
445                         (1, self.transaction, option),
446                         (2, self.height, required),
447                         (3, self.block_hash, option),
448                         (4, self.event, required),
449                 });
450                 Ok(())
451         }
452 }
453
454 impl MaybeReadable for OnchainEventEntry {
455         fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, DecodeError> {
456                 let mut txid = Txid::all_zeros();
457                 let mut transaction = None;
458                 let mut block_hash = None;
459                 let mut height = 0;
460                 let mut event = UpgradableRequired(None);
461                 read_tlv_fields!(reader, {
462                         (0, txid, required),
463                         (1, transaction, option),
464                         (2, height, required),
465                         (3, block_hash, option),
466                         (4, event, upgradable_required),
467                 });
468                 Ok(Some(Self { txid, transaction, height, block_hash, event: _init_tlv_based_struct_field!(event, upgradable_required) }))
469         }
470 }
471
472 impl_writeable_tlv_based_enum_upgradable!(OnchainEvent,
473         (0, HTLCUpdate) => {
474                 (0, source, required),
475                 (1, htlc_value_satoshis, option),
476                 (2, payment_hash, required),
477                 (3, commitment_tx_output_idx, option),
478         },
479         (1, MaturingOutput) => {
480                 (0, descriptor, required),
481         },
482         (3, FundingSpendConfirmation) => {
483                 (0, on_local_output_csv, option),
484                 (1, commitment_tx_to_counterparty_output, option),
485         },
486         (5, HTLCSpendConfirmation) => {
487                 (0, commitment_tx_output_idx, required),
488                 (2, preimage, option),
489                 (4, on_to_local_output_csv, option),
490         },
491
492 );
493
494 #[cfg_attr(any(test, fuzzing, feature = "_test_utils"), derive(PartialEq, Eq))]
495 #[derive(Clone)]
496 pub(crate) enum ChannelMonitorUpdateStep {
497         LatestHolderCommitmentTXInfo {
498                 commitment_tx: HolderCommitmentTransaction,
499                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
500                 claimed_htlcs: Vec<(SentHTLCId, PaymentPreimage)>,
501         },
502         LatestCounterpartyCommitmentTXInfo {
503                 commitment_txid: Txid,
504                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
505                 commitment_number: u64,
506                 their_per_commitment_point: PublicKey,
507         },
508         PaymentPreimage {
509                 payment_preimage: PaymentPreimage,
510         },
511         CommitmentSecret {
512                 idx: u64,
513                 secret: [u8; 32],
514         },
515         /// Used to indicate that the no future updates will occur, and likely that the latest holder
516         /// commitment transaction(s) should be broadcast, as the channel has been force-closed.
517         ChannelForceClosed {
518                 /// If set to false, we shouldn't broadcast the latest holder commitment transaction as we
519                 /// think we've fallen behind!
520                 should_broadcast: bool,
521         },
522         ShutdownScript {
523                 scriptpubkey: Script,
524         },
525 }
526
527 impl ChannelMonitorUpdateStep {
528         fn variant_name(&self) -> &'static str {
529                 match self {
530                         ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { .. } => "LatestHolderCommitmentTXInfo",
531                         ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { .. } => "LatestCounterpartyCommitmentTXInfo",
532                         ChannelMonitorUpdateStep::PaymentPreimage { .. } => "PaymentPreimage",
533                         ChannelMonitorUpdateStep::CommitmentSecret { .. } => "CommitmentSecret",
534                         ChannelMonitorUpdateStep::ChannelForceClosed { .. } => "ChannelForceClosed",
535                         ChannelMonitorUpdateStep::ShutdownScript { .. } => "ShutdownScript",
536                 }
537         }
538 }
539
540 impl_writeable_tlv_based_enum_upgradable!(ChannelMonitorUpdateStep,
541         (0, LatestHolderCommitmentTXInfo) => {
542                 (0, commitment_tx, required),
543                 (1, claimed_htlcs, vec_type),
544                 (2, htlc_outputs, vec_type),
545         },
546         (1, LatestCounterpartyCommitmentTXInfo) => {
547                 (0, commitment_txid, required),
548                 (2, commitment_number, required),
549                 (4, their_per_commitment_point, required),
550                 (6, htlc_outputs, vec_type),
551         },
552         (2, PaymentPreimage) => {
553                 (0, payment_preimage, required),
554         },
555         (3, CommitmentSecret) => {
556                 (0, idx, required),
557                 (2, secret, required),
558         },
559         (4, ChannelForceClosed) => {
560                 (0, should_broadcast, required),
561         },
562         (5, ShutdownScript) => {
563                 (0, scriptpubkey, required),
564         },
565 );
566
567 /// Details about the balance(s) available for spending once the channel appears on chain.
568 ///
569 /// See [`ChannelMonitor::get_claimable_balances`] for more details on when these will or will not
570 /// be provided.
571 #[derive(Clone, Debug, PartialEq, Eq)]
572 #[cfg_attr(test, derive(PartialOrd, Ord))]
573 pub enum Balance {
574         /// The channel is not yet closed (or the commitment or closing transaction has not yet
575         /// appeared in a block). The given balance is claimable (less on-chain fees) if the channel is
576         /// force-closed now.
577         ClaimableOnChannelClose {
578                 /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
579                 /// required to do so.
580                 claimable_amount_satoshis: u64,
581         },
582         /// The channel has been closed, and the given balance is ours but awaiting confirmations until
583         /// we consider it spendable.
584         ClaimableAwaitingConfirmations {
585                 /// The amount available to claim, in satoshis, possibly excluding the on-chain fees which
586                 /// were spent in broadcasting the transaction.
587                 claimable_amount_satoshis: u64,
588                 /// The height at which an [`Event::SpendableOutputs`] event will be generated for this
589                 /// amount.
590                 confirmation_height: u32,
591         },
592         /// The channel has been closed, and the given balance should be ours but awaiting spending
593         /// transaction confirmation. If the spending transaction does not confirm in time, it is
594         /// possible our counterparty can take the funds by broadcasting an HTLC timeout on-chain.
595         ///
596         /// Once the spending transaction confirms, before it has reached enough confirmations to be
597         /// considered safe from chain reorganizations, the balance will instead be provided via
598         /// [`Balance::ClaimableAwaitingConfirmations`].
599         ContentiousClaimable {
600                 /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
601                 /// required to do so.
602                 claimable_amount_satoshis: u64,
603                 /// The height at which the counterparty may be able to claim the balance if we have not
604                 /// done so.
605                 timeout_height: u32,
606         },
607         /// HTLCs which we sent to our counterparty which are claimable after a timeout (less on-chain
608         /// fees) if the counterparty does not know the preimage for the HTLCs. These are somewhat
609         /// likely to be claimed by our counterparty before we do.
610         MaybeTimeoutClaimableHTLC {
611                 /// The amount potentially available to claim, in satoshis, excluding the on-chain fees
612                 /// which will be required to do so.
613                 claimable_amount_satoshis: u64,
614                 /// The height at which we will be able to claim the balance if our counterparty has not
615                 /// done so.
616                 claimable_height: u32,
617         },
618         /// HTLCs which we received from our counterparty which are claimable with a preimage which we
619         /// do not currently have. This will only be claimable if we receive the preimage from the node
620         /// to which we forwarded this HTLC before the timeout.
621         MaybePreimageClaimableHTLC {
622                 /// The amount potentially available to claim, in satoshis, excluding the on-chain fees
623                 /// which will be required to do so.
624                 claimable_amount_satoshis: u64,
625                 /// The height at which our counterparty will be able to claim the balance if we have not
626                 /// yet received the preimage and claimed it ourselves.
627                 expiry_height: u32,
628         },
629         /// The channel has been closed, and our counterparty broadcasted a revoked commitment
630         /// transaction.
631         ///
632         /// Thus, we're able to claim all outputs in the commitment transaction, one of which has the
633         /// following amount.
634         CounterpartyRevokedOutputClaimable {
635                 /// The amount, in satoshis, of the output which we can claim.
636                 ///
637                 /// Note that for outputs from HTLC balances this may be excluding some on-chain fees that
638                 /// were already spent.
639                 claimable_amount_satoshis: u64,
640         },
641 }
642
643 /// An HTLC which has been irrevocably resolved on-chain, and has reached ANTI_REORG_DELAY.
644 #[derive(PartialEq, Eq)]
645 struct IrrevocablyResolvedHTLC {
646         commitment_tx_output_idx: Option<u32>,
647         /// The txid of the transaction which resolved the HTLC, this may be a commitment (if the HTLC
648         /// was not present in the confirmed commitment transaction), HTLC-Success, or HTLC-Timeout
649         /// transaction.
650         resolving_txid: Option<Txid>, // Added as optional, but always filled in, in 0.0.110
651         resolving_tx: Option<Transaction>,
652         /// Only set if the HTLC claim was ours using a payment preimage
653         payment_preimage: Option<PaymentPreimage>,
654 }
655
656 // In LDK versions prior to 0.0.111 commitment_tx_output_idx was not Option-al and
657 // IrrevocablyResolvedHTLC objects only existed for non-dust HTLCs. This was a bug, but to maintain
658 // backwards compatibility we must ensure we always write out a commitment_tx_output_idx field,
659 // using `u32::max_value()` as a sentinal to indicate the HTLC was dust.
660 impl Writeable for IrrevocablyResolvedHTLC {
661         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
662                 let mapped_commitment_tx_output_idx = self.commitment_tx_output_idx.unwrap_or(u32::max_value());
663                 write_tlv_fields!(writer, {
664                         (0, mapped_commitment_tx_output_idx, required),
665                         (1, self.resolving_txid, option),
666                         (2, self.payment_preimage, option),
667                         (3, self.resolving_tx, option),
668                 });
669                 Ok(())
670         }
671 }
672
673 impl Readable for IrrevocablyResolvedHTLC {
674         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
675                 let mut mapped_commitment_tx_output_idx = 0;
676                 let mut resolving_txid = None;
677                 let mut payment_preimage = None;
678                 let mut resolving_tx = None;
679                 read_tlv_fields!(reader, {
680                         (0, mapped_commitment_tx_output_idx, required),
681                         (1, resolving_txid, option),
682                         (2, payment_preimage, option),
683                         (3, resolving_tx, option),
684                 });
685                 Ok(Self {
686                         commitment_tx_output_idx: if mapped_commitment_tx_output_idx == u32::max_value() { None } else { Some(mapped_commitment_tx_output_idx) },
687                         resolving_txid,
688                         payment_preimage,
689                         resolving_tx,
690                 })
691         }
692 }
693
694 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
695 /// on-chain transactions to ensure no loss of funds occurs.
696 ///
697 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
698 /// information and are actively monitoring the chain.
699 ///
700 /// Pending Events or updated HTLCs which have not yet been read out by
701 /// get_and_clear_pending_monitor_events or get_and_clear_pending_events are serialized to disk and
702 /// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
703 /// gotten are fully handled before re-serializing the new state.
704 ///
705 /// Note that the deserializer is only implemented for (BlockHash, ChannelMonitor), which
706 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
707 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
708 /// returned block hash and the the current chain and then reconnecting blocks to get to the
709 /// best chain) upon deserializing the object!
710 pub struct ChannelMonitor<Signer: WriteableEcdsaChannelSigner> {
711         #[cfg(test)]
712         pub(crate) inner: Mutex<ChannelMonitorImpl<Signer>>,
713         #[cfg(not(test))]
714         inner: Mutex<ChannelMonitorImpl<Signer>>,
715 }
716
717 #[derive(PartialEq)]
718 pub(crate) struct ChannelMonitorImpl<Signer: WriteableEcdsaChannelSigner> {
719         latest_update_id: u64,
720         commitment_transaction_number_obscure_factor: u64,
721
722         destination_script: Script,
723         broadcasted_holder_revokable_script: Option<(Script, PublicKey, PublicKey)>,
724         counterparty_payment_script: Script,
725         shutdown_script: Option<Script>,
726
727         channel_keys_id: [u8; 32],
728         holder_revocation_basepoint: PublicKey,
729         funding_info: (OutPoint, Script),
730         current_counterparty_commitment_txid: Option<Txid>,
731         prev_counterparty_commitment_txid: Option<Txid>,
732
733         counterparty_commitment_params: CounterpartyCommitmentParameters,
734         funding_redeemscript: Script,
735         channel_value_satoshis: u64,
736         // first is the idx of the first of the two per-commitment points
737         their_cur_per_commitment_points: Option<(u64, PublicKey, Option<PublicKey>)>,
738
739         on_holder_tx_csv: u16,
740
741         commitment_secrets: CounterpartyCommitmentSecrets,
742         /// The set of outpoints in each counterparty commitment transaction. We always need at least
743         /// the payment hash from `HTLCOutputInCommitment` to claim even a revoked commitment
744         /// transaction broadcast as we need to be able to construct the witness script in all cases.
745         counterparty_claimable_outpoints: HashMap<Txid, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
746         /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
747         /// Nor can we figure out their commitment numbers without the commitment transaction they are
748         /// spending. Thus, in order to claim them via revocation key, we track all the counterparty
749         /// commitment transactions which we find on-chain, mapping them to the commitment number which
750         /// can be used to derive the revocation key and claim the transactions.
751         counterparty_commitment_txn_on_chain: HashMap<Txid, u64>,
752         /// Cache used to make pruning of payment_preimages faster.
753         /// Maps payment_hash values to commitment numbers for counterparty transactions for non-revoked
754         /// counterparty transactions (ie should remain pretty small).
755         /// Serialized to disk but should generally not be sent to Watchtowers.
756         counterparty_hash_commitment_number: HashMap<PaymentHash, u64>,
757
758         counterparty_fulfilled_htlcs: HashMap<SentHTLCId, PaymentPreimage>,
759
760         // We store two holder commitment transactions to avoid any race conditions where we may update
761         // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
762         // various monitors for one channel being out of sync, and us broadcasting a holder
763         // transaction for which we have deleted claim information on some watchtowers.
764         prev_holder_signed_commitment_tx: Option<HolderSignedTx>,
765         current_holder_commitment_tx: HolderSignedTx,
766
767         // Used just for ChannelManager to make sure it has the latest channel data during
768         // deserialization
769         current_counterparty_commitment_number: u64,
770         // Used just for ChannelManager to make sure it has the latest channel data during
771         // deserialization
772         current_holder_commitment_number: u64,
773
774         /// The set of payment hashes from inbound payments for which we know the preimage. Payment
775         /// preimages that are not included in any unrevoked local commitment transaction or unrevoked
776         /// remote commitment transactions are automatically removed when commitment transactions are
777         /// revoked.
778         payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
779
780         // Note that `MonitorEvent`s MUST NOT be generated during update processing, only generated
781         // during chain data processing. This prevents a race in `ChainMonitor::update_channel` (and
782         // presumably user implementations thereof as well) where we update the in-memory channel
783         // object, then before the persistence finishes (as it's all under a read-lock), we return
784         // pending events to the user or to the relevant `ChannelManager`. Then, on reload, we'll have
785         // the pre-event state here, but have processed the event in the `ChannelManager`.
786         // Note that because the `event_lock` in `ChainMonitor` is only taken in
787         // block/transaction-connected events and *not* during block/transaction-disconnected events,
788         // we further MUST NOT generate events during block/transaction-disconnection.
789         pending_monitor_events: Vec<MonitorEvent>,
790
791         pending_events: Vec<Event>,
792
793         // Used to track on-chain events (i.e., transactions part of channels confirmed on chain) on
794         // which to take actions once they reach enough confirmations. Each entry includes the
795         // transaction's id and the height when the transaction was confirmed on chain.
796         onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
797
798         // If we get serialized out and re-read, we need to make sure that the chain monitoring
799         // interface knows about the TXOs that we want to be notified of spends of. We could probably
800         // be smart and derive them from the above storage fields, but its much simpler and more
801         // Obviously Correct (tm) if we just keep track of them explicitly.
802         outputs_to_watch: HashMap<Txid, Vec<(u32, Script)>>,
803
804         #[cfg(test)]
805         pub onchain_tx_handler: OnchainTxHandler<Signer>,
806         #[cfg(not(test))]
807         onchain_tx_handler: OnchainTxHandler<Signer>,
808
809         // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
810         // channel has been force-closed. After this is set, no further holder commitment transaction
811         // updates may occur, and we panic!() if one is provided.
812         lockdown_from_offchain: bool,
813
814         // Set once we've signed a holder commitment transaction and handed it over to our
815         // OnchainTxHandler. After this is set, no future updates to our holder commitment transactions
816         // may occur, and we fail any such monitor updates.
817         //
818         // In case of update rejection due to a locally already signed commitment transaction, we
819         // nevertheless store update content to track in case of concurrent broadcast by another
820         // remote monitor out-of-order with regards to the block view.
821         holder_tx_signed: bool,
822
823         // If a spend of the funding output is seen, we set this to true and reject any further
824         // updates. This prevents any further changes in the offchain state no matter the order
825         // of block connection between ChannelMonitors and the ChannelManager.
826         funding_spend_seen: bool,
827
828         /// Set to `Some` of the confirmed transaction spending the funding input of the channel after
829         /// reaching `ANTI_REORG_DELAY` confirmations.
830         funding_spend_confirmed: Option<Txid>,
831
832         confirmed_commitment_tx_counterparty_output: CommitmentTxCounterpartyOutputInfo,
833         /// The set of HTLCs which have been either claimed or failed on chain and have reached
834         /// the requisite confirmations on the claim/fail transaction (either ANTI_REORG_DELAY or the
835         /// spending CSV for revocable outputs).
836         htlcs_resolved_on_chain: Vec<IrrevocablyResolvedHTLC>,
837
838         /// The set of `SpendableOutput` events which we have already passed upstream to be claimed.
839         /// These are tracked explicitly to ensure that we don't generate the same events redundantly
840         /// if users duplicatively confirm old transactions. Specifically for transactions claiming a
841         /// revoked remote outpoint we otherwise have no tracking at all once they've reached
842         /// [`ANTI_REORG_DELAY`], so we have to track them here.
843         spendable_txids_confirmed: Vec<Txid>,
844
845         // We simply modify best_block in Channel's block_connected so that serialization is
846         // consistent but hopefully the users' copy handles block_connected in a consistent way.
847         // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
848         // their best_block from its state and not based on updated copies that didn't run through
849         // the full block_connected).
850         best_block: BestBlock,
851
852         /// The node_id of our counterparty
853         counterparty_node_id: Option<PublicKey>,
854 }
855
856 /// Transaction outputs to watch for on-chain spends.
857 pub type TransactionOutputs = (Txid, Vec<(u32, TxOut)>);
858
859 impl<Signer: WriteableEcdsaChannelSigner> PartialEq for ChannelMonitor<Signer> where Signer: PartialEq {
860         fn eq(&self, other: &Self) -> bool {
861                 // We need some kind of total lockorder. Absent a better idea, we sort by position in
862                 // memory and take locks in that order (assuming that we can't move within memory while a
863                 // lock is held).
864                 let ord = ((self as *const _) as usize) < ((other as *const _) as usize);
865                 let a = if ord { self.inner.unsafe_well_ordered_double_lock_self() } else { other.inner.unsafe_well_ordered_double_lock_self() };
866                 let b = if ord { other.inner.unsafe_well_ordered_double_lock_self() } else { self.inner.unsafe_well_ordered_double_lock_self() };
867                 a.eq(&b)
868         }
869 }
870
871 impl<Signer: WriteableEcdsaChannelSigner> Writeable for ChannelMonitor<Signer> {
872         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
873                 self.inner.lock().unwrap().write(writer)
874         }
875 }
876
877 // These are also used for ChannelMonitorUpdate, above.
878 const SERIALIZATION_VERSION: u8 = 1;
879 const MIN_SERIALIZATION_VERSION: u8 = 1;
880
881 impl<Signer: WriteableEcdsaChannelSigner> Writeable for ChannelMonitorImpl<Signer> {
882         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
883                 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
884
885                 self.latest_update_id.write(writer)?;
886
887                 // Set in initial Channel-object creation, so should always be set by now:
888                 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
889
890                 self.destination_script.write(writer)?;
891                 if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
892                         writer.write_all(&[0; 1])?;
893                         broadcasted_holder_revokable_script.0.write(writer)?;
894                         broadcasted_holder_revokable_script.1.write(writer)?;
895                         broadcasted_holder_revokable_script.2.write(writer)?;
896                 } else {
897                         writer.write_all(&[1; 1])?;
898                 }
899
900                 self.counterparty_payment_script.write(writer)?;
901                 match &self.shutdown_script {
902                         Some(script) => script.write(writer)?,
903                         None => Script::new().write(writer)?,
904                 }
905
906                 self.channel_keys_id.write(writer)?;
907                 self.holder_revocation_basepoint.write(writer)?;
908                 writer.write_all(&self.funding_info.0.txid[..])?;
909                 writer.write_all(&self.funding_info.0.index.to_be_bytes())?;
910                 self.funding_info.1.write(writer)?;
911                 self.current_counterparty_commitment_txid.write(writer)?;
912                 self.prev_counterparty_commitment_txid.write(writer)?;
913
914                 self.counterparty_commitment_params.write(writer)?;
915                 self.funding_redeemscript.write(writer)?;
916                 self.channel_value_satoshis.write(writer)?;
917
918                 match self.their_cur_per_commitment_points {
919                         Some((idx, pubkey, second_option)) => {
920                                 writer.write_all(&byte_utils::be48_to_array(idx))?;
921                                 writer.write_all(&pubkey.serialize())?;
922                                 match second_option {
923                                         Some(second_pubkey) => {
924                                                 writer.write_all(&second_pubkey.serialize())?;
925                                         },
926                                         None => {
927                                                 writer.write_all(&[0; 33])?;
928                                         },
929                                 }
930                         },
931                         None => {
932                                 writer.write_all(&byte_utils::be48_to_array(0))?;
933                         },
934                 }
935
936                 writer.write_all(&self.on_holder_tx_csv.to_be_bytes())?;
937
938                 self.commitment_secrets.write(writer)?;
939
940                 macro_rules! serialize_htlc_in_commitment {
941                         ($htlc_output: expr) => {
942                                 writer.write_all(&[$htlc_output.offered as u8; 1])?;
943                                 writer.write_all(&$htlc_output.amount_msat.to_be_bytes())?;
944                                 writer.write_all(&$htlc_output.cltv_expiry.to_be_bytes())?;
945                                 writer.write_all(&$htlc_output.payment_hash.0[..])?;
946                                 $htlc_output.transaction_output_index.write(writer)?;
947                         }
948                 }
949
950                 writer.write_all(&(self.counterparty_claimable_outpoints.len() as u64).to_be_bytes())?;
951                 for (ref txid, ref htlc_infos) in self.counterparty_claimable_outpoints.iter() {
952                         writer.write_all(&txid[..])?;
953                         writer.write_all(&(htlc_infos.len() as u64).to_be_bytes())?;
954                         for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
955                                 debug_assert!(htlc_source.is_none() || Some(**txid) == self.current_counterparty_commitment_txid
956                                                 || Some(**txid) == self.prev_counterparty_commitment_txid,
957                                         "HTLC Sources for all revoked commitment transactions should be none!");
958                                 serialize_htlc_in_commitment!(htlc_output);
959                                 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
960                         }
961                 }
962
963                 writer.write_all(&(self.counterparty_commitment_txn_on_chain.len() as u64).to_be_bytes())?;
964                 for (ref txid, commitment_number) in self.counterparty_commitment_txn_on_chain.iter() {
965                         writer.write_all(&txid[..])?;
966                         writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
967                 }
968
969                 writer.write_all(&(self.counterparty_hash_commitment_number.len() as u64).to_be_bytes())?;
970                 for (ref payment_hash, commitment_number) in self.counterparty_hash_commitment_number.iter() {
971                         writer.write_all(&payment_hash.0[..])?;
972                         writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
973                 }
974
975                 if let Some(ref prev_holder_tx) = self.prev_holder_signed_commitment_tx {
976                         writer.write_all(&[1; 1])?;
977                         prev_holder_tx.write(writer)?;
978                 } else {
979                         writer.write_all(&[0; 1])?;
980                 }
981
982                 self.current_holder_commitment_tx.write(writer)?;
983
984                 writer.write_all(&byte_utils::be48_to_array(self.current_counterparty_commitment_number))?;
985                 writer.write_all(&byte_utils::be48_to_array(self.current_holder_commitment_number))?;
986
987                 writer.write_all(&(self.payment_preimages.len() as u64).to_be_bytes())?;
988                 for payment_preimage in self.payment_preimages.values() {
989                         writer.write_all(&payment_preimage.0[..])?;
990                 }
991
992                 writer.write_all(&(self.pending_monitor_events.iter().filter(|ev| match ev {
993                         MonitorEvent::HTLCEvent(_) => true,
994                         MonitorEvent::CommitmentTxConfirmed(_) => true,
995                         _ => false,
996                 }).count() as u64).to_be_bytes())?;
997                 for event in self.pending_monitor_events.iter() {
998                         match event {
999                                 MonitorEvent::HTLCEvent(upd) => {
1000                                         0u8.write(writer)?;
1001                                         upd.write(writer)?;
1002                                 },
1003                                 MonitorEvent::CommitmentTxConfirmed(_) => 1u8.write(writer)?,
1004                                 _ => {}, // Covered in the TLV writes below
1005                         }
1006                 }
1007
1008                 writer.write_all(&(self.pending_events.len() as u64).to_be_bytes())?;
1009                 for event in self.pending_events.iter() {
1010                         event.write(writer)?;
1011                 }
1012
1013                 self.best_block.block_hash().write(writer)?;
1014                 writer.write_all(&self.best_block.height().to_be_bytes())?;
1015
1016                 writer.write_all(&(self.onchain_events_awaiting_threshold_conf.len() as u64).to_be_bytes())?;
1017                 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
1018                         entry.write(writer)?;
1019                 }
1020
1021                 (self.outputs_to_watch.len() as u64).write(writer)?;
1022                 for (txid, idx_scripts) in self.outputs_to_watch.iter() {
1023                         txid.write(writer)?;
1024                         (idx_scripts.len() as u64).write(writer)?;
1025                         for (idx, script) in idx_scripts.iter() {
1026                                 idx.write(writer)?;
1027                                 script.write(writer)?;
1028                         }
1029                 }
1030                 self.onchain_tx_handler.write(writer)?;
1031
1032                 self.lockdown_from_offchain.write(writer)?;
1033                 self.holder_tx_signed.write(writer)?;
1034
1035                 write_tlv_fields!(writer, {
1036                         (1, self.funding_spend_confirmed, option),
1037                         (3, self.htlcs_resolved_on_chain, vec_type),
1038                         (5, self.pending_monitor_events, vec_type),
1039                         (7, self.funding_spend_seen, required),
1040                         (9, self.counterparty_node_id, option),
1041                         (11, self.confirmed_commitment_tx_counterparty_output, option),
1042                         (13, self.spendable_txids_confirmed, vec_type),
1043                         (15, self.counterparty_fulfilled_htlcs, required),
1044                 });
1045
1046                 Ok(())
1047         }
1048 }
1049
1050 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
1051         /// For lockorder enforcement purposes, we need to have a single site which constructs the
1052         /// `inner` mutex, otherwise cases where we lock two monitors at the same time (eg in our
1053         /// PartialEq implementation) we may decide a lockorder violation has occurred.
1054         fn from_impl(imp: ChannelMonitorImpl<Signer>) -> Self {
1055                 ChannelMonitor { inner: Mutex::new(imp) }
1056         }
1057
1058         pub(crate) fn new(secp_ctx: Secp256k1<secp256k1::All>, keys: Signer, shutdown_script: Option<Script>,
1059                           on_counterparty_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
1060                           channel_parameters: &ChannelTransactionParameters,
1061                           funding_redeemscript: Script, channel_value_satoshis: u64,
1062                           commitment_transaction_number_obscure_factor: u64,
1063                           initial_holder_commitment_tx: HolderCommitmentTransaction,
1064                           best_block: BestBlock, counterparty_node_id: PublicKey) -> ChannelMonitor<Signer> {
1065
1066                 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
1067                 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
1068                 let counterparty_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
1069
1070                 let counterparty_channel_parameters = channel_parameters.counterparty_parameters.as_ref().unwrap();
1071                 let counterparty_delayed_payment_base_key = counterparty_channel_parameters.pubkeys.delayed_payment_basepoint;
1072                 let counterparty_htlc_base_key = counterparty_channel_parameters.pubkeys.htlc_basepoint;
1073                 let counterparty_commitment_params = CounterpartyCommitmentParameters { counterparty_delayed_payment_base_key, counterparty_htlc_base_key, on_counterparty_tx_csv };
1074
1075                 let channel_keys_id = keys.channel_keys_id();
1076                 let holder_revocation_basepoint = keys.pubkeys().revocation_basepoint;
1077
1078                 // block for Rust 1.34 compat
1079                 let (holder_commitment_tx, current_holder_commitment_number) = {
1080                         let trusted_tx = initial_holder_commitment_tx.trust();
1081                         let txid = trusted_tx.txid();
1082
1083                         let tx_keys = trusted_tx.keys();
1084                         let holder_commitment_tx = HolderSignedTx {
1085                                 txid,
1086                                 revocation_key: tx_keys.revocation_key,
1087                                 a_htlc_key: tx_keys.broadcaster_htlc_key,
1088                                 b_htlc_key: tx_keys.countersignatory_htlc_key,
1089                                 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
1090                                 per_commitment_point: tx_keys.per_commitment_point,
1091                                 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
1092                                 to_self_value_sat: initial_holder_commitment_tx.to_broadcaster_value_sat(),
1093                                 feerate_per_kw: trusted_tx.feerate_per_kw(),
1094                         };
1095                         (holder_commitment_tx, trusted_tx.commitment_number())
1096                 };
1097
1098                 let onchain_tx_handler =
1099                         OnchainTxHandler::new(destination_script.clone(), keys,
1100                         channel_parameters.clone(), initial_holder_commitment_tx, secp_ctx);
1101
1102                 let mut outputs_to_watch = HashMap::new();
1103                 outputs_to_watch.insert(funding_info.0.txid, vec![(funding_info.0.index as u32, funding_info.1.clone())]);
1104
1105                 Self::from_impl(ChannelMonitorImpl {
1106                         latest_update_id: 0,
1107                         commitment_transaction_number_obscure_factor,
1108
1109                         destination_script: destination_script.clone(),
1110                         broadcasted_holder_revokable_script: None,
1111                         counterparty_payment_script,
1112                         shutdown_script,
1113
1114                         channel_keys_id,
1115                         holder_revocation_basepoint,
1116                         funding_info,
1117                         current_counterparty_commitment_txid: None,
1118                         prev_counterparty_commitment_txid: None,
1119
1120                         counterparty_commitment_params,
1121                         funding_redeemscript,
1122                         channel_value_satoshis,
1123                         their_cur_per_commitment_points: None,
1124
1125                         on_holder_tx_csv: counterparty_channel_parameters.selected_contest_delay,
1126
1127                         commitment_secrets: CounterpartyCommitmentSecrets::new(),
1128                         counterparty_claimable_outpoints: HashMap::new(),
1129                         counterparty_commitment_txn_on_chain: HashMap::new(),
1130                         counterparty_hash_commitment_number: HashMap::new(),
1131                         counterparty_fulfilled_htlcs: HashMap::new(),
1132
1133                         prev_holder_signed_commitment_tx: None,
1134                         current_holder_commitment_tx: holder_commitment_tx,
1135                         current_counterparty_commitment_number: 1 << 48,
1136                         current_holder_commitment_number,
1137
1138                         payment_preimages: HashMap::new(),
1139                         pending_monitor_events: Vec::new(),
1140                         pending_events: Vec::new(),
1141
1142                         onchain_events_awaiting_threshold_conf: Vec::new(),
1143                         outputs_to_watch,
1144
1145                         onchain_tx_handler,
1146
1147                         lockdown_from_offchain: false,
1148                         holder_tx_signed: false,
1149                         funding_spend_seen: false,
1150                         funding_spend_confirmed: None,
1151                         confirmed_commitment_tx_counterparty_output: None,
1152                         htlcs_resolved_on_chain: Vec::new(),
1153                         spendable_txids_confirmed: Vec::new(),
1154
1155                         best_block,
1156                         counterparty_node_id: Some(counterparty_node_id),
1157                 })
1158         }
1159
1160         #[cfg(test)]
1161         fn provide_secret(&self, idx: u64, secret: [u8; 32]) -> Result<(), &'static str> {
1162                 self.inner.lock().unwrap().provide_secret(idx, secret)
1163         }
1164
1165         /// Informs this monitor of the latest counterparty (ie non-broadcastable) commitment transaction.
1166         /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1167         /// possibly future revocation/preimage information) to claim outputs where possible.
1168         /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1169         pub(crate) fn provide_latest_counterparty_commitment_tx<L: Deref>(
1170                 &self,
1171                 txid: Txid,
1172                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
1173                 commitment_number: u64,
1174                 their_per_commitment_point: PublicKey,
1175                 logger: &L,
1176         ) where L::Target: Logger {
1177                 self.inner.lock().unwrap().provide_latest_counterparty_commitment_tx(
1178                         txid, htlc_outputs, commitment_number, their_per_commitment_point, logger)
1179         }
1180
1181         #[cfg(test)]
1182         fn provide_latest_holder_commitment_tx(
1183                 &self, holder_commitment_tx: HolderCommitmentTransaction,
1184                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
1185         ) -> Result<(), ()> {
1186                 self.inner.lock().unwrap().provide_latest_holder_commitment_tx(holder_commitment_tx, htlc_outputs, &Vec::new()).map_err(|_| ())
1187         }
1188
1189         /// This is used to provide payment preimage(s) out-of-band during startup without updating the
1190         /// off-chain state with a new commitment transaction.
1191         pub(crate) fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(
1192                 &self,
1193                 payment_hash: &PaymentHash,
1194                 payment_preimage: &PaymentPreimage,
1195                 broadcaster: &B,
1196                 fee_estimator: &LowerBoundedFeeEstimator<F>,
1197                 logger: &L,
1198         ) where
1199                 B::Target: BroadcasterInterface,
1200                 F::Target: FeeEstimator,
1201                 L::Target: Logger,
1202         {
1203                 self.inner.lock().unwrap().provide_payment_preimage(
1204                         payment_hash, payment_preimage, broadcaster, fee_estimator, logger)
1205         }
1206
1207         pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(
1208                 &self,
1209                 broadcaster: &B,
1210                 logger: &L,
1211         ) where
1212                 B::Target: BroadcasterInterface,
1213                 L::Target: Logger,
1214         {
1215                 self.inner.lock().unwrap().broadcast_latest_holder_commitment_txn(broadcaster, logger);
1216         }
1217
1218         /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1219         /// itself.
1220         ///
1221         /// panics if the given update is not the next update by update_id.
1222         pub fn update_monitor<B: Deref, F: Deref, L: Deref>(
1223                 &self,
1224                 updates: &ChannelMonitorUpdate,
1225                 broadcaster: &B,
1226                 fee_estimator: F,
1227                 logger: &L,
1228         ) -> Result<(), ()>
1229         where
1230                 B::Target: BroadcasterInterface,
1231                 F::Target: FeeEstimator,
1232                 L::Target: Logger,
1233         {
1234                 self.inner.lock().unwrap().update_monitor(updates, broadcaster, fee_estimator, logger)
1235         }
1236
1237         /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1238         /// ChannelMonitor.
1239         pub fn get_latest_update_id(&self) -> u64 {
1240                 self.inner.lock().unwrap().get_latest_update_id()
1241         }
1242
1243         /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1244         pub fn get_funding_txo(&self) -> (OutPoint, Script) {
1245                 self.inner.lock().unwrap().get_funding_txo().clone()
1246         }
1247
1248         /// Gets a list of txids, with their output scripts (in the order they appear in the
1249         /// transaction), which we must learn about spends of via block_connected().
1250         pub fn get_outputs_to_watch(&self) -> Vec<(Txid, Vec<(u32, Script)>)> {
1251                 self.inner.lock().unwrap().get_outputs_to_watch()
1252                         .iter().map(|(txid, outputs)| (*txid, outputs.clone())).collect()
1253         }
1254
1255         /// Loads the funding txo and outputs to watch into the given `chain::Filter` by repeatedly
1256         /// calling `chain::Filter::register_output` and `chain::Filter::register_tx` until all outputs
1257         /// have been registered.
1258         pub fn load_outputs_to_watch<F: Deref>(&self, filter: &F) where F::Target: chain::Filter {
1259                 let lock = self.inner.lock().unwrap();
1260                 filter.register_tx(&lock.get_funding_txo().0.txid, &lock.get_funding_txo().1);
1261                 for (txid, outputs) in lock.get_outputs_to_watch().iter() {
1262                         for (index, script_pubkey) in outputs.iter() {
1263                                 assert!(*index <= u16::max_value() as u32);
1264                                 filter.register_output(WatchedOutput {
1265                                         block_hash: None,
1266                                         outpoint: OutPoint { txid: *txid, index: *index as u16 },
1267                                         script_pubkey: script_pubkey.clone(),
1268                                 });
1269                         }
1270                 }
1271         }
1272
1273         /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1274         /// ChannelManager via [`chain::Watch::release_pending_monitor_events`].
1275         pub fn get_and_clear_pending_monitor_events(&self) -> Vec<MonitorEvent> {
1276                 self.inner.lock().unwrap().get_and_clear_pending_monitor_events()
1277         }
1278
1279         /// Gets the list of pending events which were generated by previous actions, clearing the list
1280         /// in the process.
1281         ///
1282         /// This is called by the [`EventsProvider::process_pending_events`] implementation for
1283         /// [`ChainMonitor`].
1284         ///
1285         /// [`EventsProvider::process_pending_events`]: crate::util::events::EventsProvider::process_pending_events
1286         /// [`ChainMonitor`]: crate::chain::chainmonitor::ChainMonitor
1287         pub fn get_and_clear_pending_events(&self) -> Vec<Event> {
1288                 self.inner.lock().unwrap().get_and_clear_pending_events()
1289         }
1290
1291         pub(crate) fn get_min_seen_secret(&self) -> u64 {
1292                 self.inner.lock().unwrap().get_min_seen_secret()
1293         }
1294
1295         pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1296                 self.inner.lock().unwrap().get_cur_counterparty_commitment_number()
1297         }
1298
1299         pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
1300                 self.inner.lock().unwrap().get_cur_holder_commitment_number()
1301         }
1302
1303         /// Gets the `node_id` of the counterparty for this channel.
1304         ///
1305         /// Will be `None` for channels constructed on LDK versions prior to 0.0.110 and always `Some`
1306         /// otherwise.
1307         pub fn get_counterparty_node_id(&self) -> Option<PublicKey> {
1308                 self.inner.lock().unwrap().counterparty_node_id
1309         }
1310
1311         /// Used by ChannelManager deserialization to broadcast the latest holder state if its copy of
1312         /// the Channel was out-of-date.
1313         ///
1314         /// You may also use this to broadcast the latest local commitment transaction, either because
1315         /// a monitor update failed with [`ChannelMonitorUpdateStatus::PermanentFailure`] or because we've
1316         /// fallen behind (i.e. we've received proof that our counterparty side knows a revocation
1317         /// secret we gave them that they shouldn't know).
1318         ///
1319         /// Broadcasting these transactions in the second case is UNSAFE, as they allow counterparty
1320         /// side to punish you. Nevertheless you may want to broadcast them if counterparty doesn't
1321         /// close channel with their commitment transaction after a substantial amount of time. Best
1322         /// may be to contact the other node operator out-of-band to coordinate other options available
1323         /// to you. In any-case, the choice is up to you.
1324         ///
1325         /// [`ChannelMonitorUpdateStatus::PermanentFailure`]: super::ChannelMonitorUpdateStatus::PermanentFailure
1326         pub fn get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1327         where L::Target: Logger {
1328                 self.inner.lock().unwrap().get_latest_holder_commitment_txn(logger)
1329         }
1330
1331         /// Unsafe test-only version of get_latest_holder_commitment_txn used by our test framework
1332         /// to bypass HolderCommitmentTransaction state update lockdown after signature and generate
1333         /// revoked commitment transaction.
1334         #[cfg(any(test, feature = "unsafe_revoked_tx_signing"))]
1335         pub fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1336         where L::Target: Logger {
1337                 self.inner.lock().unwrap().unsafe_get_latest_holder_commitment_txn(logger)
1338         }
1339
1340         /// Processes transactions in a newly connected block, which may result in any of the following:
1341         /// - update the monitor's state against resolved HTLCs
1342         /// - punish the counterparty in the case of seeing a revoked commitment transaction
1343         /// - force close the channel and claim/timeout incoming/outgoing HTLCs if near expiration
1344         /// - detect settled outputs for later spending
1345         /// - schedule and bump any in-flight claims
1346         ///
1347         /// Returns any new outputs to watch from `txdata`; after called, these are also included in
1348         /// [`get_outputs_to_watch`].
1349         ///
1350         /// [`get_outputs_to_watch`]: #method.get_outputs_to_watch
1351         pub fn block_connected<B: Deref, F: Deref, L: Deref>(
1352                 &self,
1353                 header: &BlockHeader,
1354                 txdata: &TransactionData,
1355                 height: u32,
1356                 broadcaster: B,
1357                 fee_estimator: F,
1358                 logger: L,
1359         ) -> Vec<TransactionOutputs>
1360         where
1361                 B::Target: BroadcasterInterface,
1362                 F::Target: FeeEstimator,
1363                 L::Target: Logger,
1364         {
1365                 self.inner.lock().unwrap().block_connected(
1366                         header, txdata, height, broadcaster, fee_estimator, logger)
1367         }
1368
1369         /// Determines if the disconnected block contained any transactions of interest and updates
1370         /// appropriately.
1371         pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(
1372                 &self,
1373                 header: &BlockHeader,
1374                 height: u32,
1375                 broadcaster: B,
1376                 fee_estimator: F,
1377                 logger: L,
1378         ) where
1379                 B::Target: BroadcasterInterface,
1380                 F::Target: FeeEstimator,
1381                 L::Target: Logger,
1382         {
1383                 self.inner.lock().unwrap().block_disconnected(
1384                         header, height, broadcaster, fee_estimator, logger)
1385         }
1386
1387         /// Processes transactions confirmed in a block with the given header and height, returning new
1388         /// outputs to watch. See [`block_connected`] for details.
1389         ///
1390         /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
1391         /// blocks. See [`chain::Confirm`] for calling expectations.
1392         ///
1393         /// [`block_connected`]: Self::block_connected
1394         pub fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
1395                 &self,
1396                 header: &BlockHeader,
1397                 txdata: &TransactionData,
1398                 height: u32,
1399                 broadcaster: B,
1400                 fee_estimator: F,
1401                 logger: L,
1402         ) -> Vec<TransactionOutputs>
1403         where
1404                 B::Target: BroadcasterInterface,
1405                 F::Target: FeeEstimator,
1406                 L::Target: Logger,
1407         {
1408                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1409                 self.inner.lock().unwrap().transactions_confirmed(
1410                         header, txdata, height, broadcaster, &bounded_fee_estimator, logger)
1411         }
1412
1413         /// Processes a transaction that was reorganized out of the chain.
1414         ///
1415         /// Used instead of [`block_disconnected`] by clients that are notified of transactions rather
1416         /// than blocks. See [`chain::Confirm`] for calling expectations.
1417         ///
1418         /// [`block_disconnected`]: Self::block_disconnected
1419         pub fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
1420                 &self,
1421                 txid: &Txid,
1422                 broadcaster: B,
1423                 fee_estimator: F,
1424                 logger: L,
1425         ) where
1426                 B::Target: BroadcasterInterface,
1427                 F::Target: FeeEstimator,
1428                 L::Target: Logger,
1429         {
1430                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1431                 self.inner.lock().unwrap().transaction_unconfirmed(
1432                         txid, broadcaster, &bounded_fee_estimator, logger);
1433         }
1434
1435         /// Updates the monitor with the current best chain tip, returning new outputs to watch. See
1436         /// [`block_connected`] for details.
1437         ///
1438         /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
1439         /// blocks. See [`chain::Confirm`] for calling expectations.
1440         ///
1441         /// [`block_connected`]: Self::block_connected
1442         pub fn best_block_updated<B: Deref, F: Deref, L: Deref>(
1443                 &self,
1444                 header: &BlockHeader,
1445                 height: u32,
1446                 broadcaster: B,
1447                 fee_estimator: F,
1448                 logger: L,
1449         ) -> Vec<TransactionOutputs>
1450         where
1451                 B::Target: BroadcasterInterface,
1452                 F::Target: FeeEstimator,
1453                 L::Target: Logger,
1454         {
1455                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1456                 self.inner.lock().unwrap().best_block_updated(
1457                         header, height, broadcaster, &bounded_fee_estimator, logger)
1458         }
1459
1460         /// Returns the set of txids that should be monitored for re-organization out of the chain.
1461         pub fn get_relevant_txids(&self) -> Vec<(Txid, Option<BlockHash>)> {
1462                 let inner = self.inner.lock().unwrap();
1463                 let mut txids: Vec<(Txid, Option<BlockHash>)> = inner.onchain_events_awaiting_threshold_conf
1464                         .iter()
1465                         .map(|entry| (entry.txid, entry.block_hash))
1466                         .chain(inner.onchain_tx_handler.get_relevant_txids().into_iter())
1467                         .collect();
1468                 txids.sort_unstable();
1469                 txids.dedup();
1470                 txids
1471         }
1472
1473         /// Gets the latest best block which was connected either via the [`chain::Listen`] or
1474         /// [`chain::Confirm`] interfaces.
1475         pub fn current_best_block(&self) -> BestBlock {
1476                 self.inner.lock().unwrap().best_block.clone()
1477         }
1478 }
1479
1480 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
1481         /// Helper for get_claimable_balances which does the work for an individual HTLC, generating up
1482         /// to one `Balance` for the HTLC.
1483         fn get_htlc_balance(&self, htlc: &HTLCOutputInCommitment, holder_commitment: bool,
1484                 counterparty_revoked_commitment: bool, confirmed_txid: Option<Txid>)
1485         -> Option<Balance> {
1486                 let htlc_commitment_tx_output_idx =
1487                         if let Some(v) = htlc.transaction_output_index { v } else { return None; };
1488
1489                 let mut htlc_spend_txid_opt = None;
1490                 let mut htlc_spend_tx_opt = None;
1491                 let mut holder_timeout_spend_pending = None;
1492                 let mut htlc_spend_pending = None;
1493                 let mut holder_delayed_output_pending = None;
1494                 for event in self.onchain_events_awaiting_threshold_conf.iter() {
1495                         match event.event {
1496                                 OnchainEvent::HTLCUpdate { commitment_tx_output_idx, htlc_value_satoshis, .. }
1497                                 if commitment_tx_output_idx == Some(htlc_commitment_tx_output_idx) => {
1498                                         debug_assert!(htlc_spend_txid_opt.is_none());
1499                                         htlc_spend_txid_opt = Some(&event.txid);
1500                                         debug_assert!(htlc_spend_tx_opt.is_none());
1501                                         htlc_spend_tx_opt = event.transaction.as_ref();
1502                                         debug_assert!(holder_timeout_spend_pending.is_none());
1503                                         debug_assert_eq!(htlc_value_satoshis.unwrap(), htlc.amount_msat / 1000);
1504                                         holder_timeout_spend_pending = Some(event.confirmation_threshold());
1505                                 },
1506                                 OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, preimage, .. }
1507                                 if commitment_tx_output_idx == htlc_commitment_tx_output_idx => {
1508                                         debug_assert!(htlc_spend_txid_opt.is_none());
1509                                         htlc_spend_txid_opt = Some(&event.txid);
1510                                         debug_assert!(htlc_spend_tx_opt.is_none());
1511                                         htlc_spend_tx_opt = event.transaction.as_ref();
1512                                         debug_assert!(htlc_spend_pending.is_none());
1513                                         htlc_spend_pending = Some((event.confirmation_threshold(), preimage.is_some()));
1514                                 },
1515                                 OnchainEvent::MaturingOutput {
1516                                         descriptor: SpendableOutputDescriptor::DelayedPaymentOutput(ref descriptor) }
1517                                 if descriptor.outpoint.index as u32 == htlc_commitment_tx_output_idx => {
1518                                         debug_assert!(holder_delayed_output_pending.is_none());
1519                                         holder_delayed_output_pending = Some(event.confirmation_threshold());
1520                                 },
1521                                 _ => {},
1522                         }
1523                 }
1524                 let htlc_resolved = self.htlcs_resolved_on_chain.iter()
1525                         .find(|v| if v.commitment_tx_output_idx == Some(htlc_commitment_tx_output_idx) {
1526                                 debug_assert!(htlc_spend_txid_opt.is_none());
1527                                 htlc_spend_txid_opt = v.resolving_txid.as_ref();
1528                                 debug_assert!(htlc_spend_tx_opt.is_none());
1529                                 htlc_spend_tx_opt = v.resolving_tx.as_ref();
1530                                 true
1531                         } else { false });
1532                 debug_assert!(holder_timeout_spend_pending.is_some() as u8 + htlc_spend_pending.is_some() as u8 + htlc_resolved.is_some() as u8 <= 1);
1533
1534                 let htlc_commitment_outpoint = BitcoinOutPoint::new(confirmed_txid.unwrap(), htlc_commitment_tx_output_idx);
1535                 let htlc_output_to_spend =
1536                         if let Some(txid) = htlc_spend_txid_opt {
1537                                 // Because HTLC transactions either only have 1 input and 1 output (pre-anchors) or
1538                                 // are signed with SIGHASH_SINGLE|ANYONECANPAY under BIP-0143 (post-anchors), we can
1539                                 // locate the correct output by ensuring its adjacent input spends the HTLC output
1540                                 // in the commitment.
1541                                 if let Some(ref tx) = htlc_spend_tx_opt {
1542                                         let htlc_input_idx_opt = tx.input.iter().enumerate()
1543                                                 .find(|(_, input)| input.previous_output == htlc_commitment_outpoint)
1544                                                 .map(|(idx, _)| idx as u32);
1545                                         debug_assert!(htlc_input_idx_opt.is_some());
1546                                         BitcoinOutPoint::new(*txid, htlc_input_idx_opt.unwrap_or(0))
1547                                 } else {
1548                                         debug_assert!(!self.onchain_tx_handler.opt_anchors());
1549                                         BitcoinOutPoint::new(*txid, 0)
1550                                 }
1551                         } else {
1552                                 htlc_commitment_outpoint
1553                         };
1554                 let htlc_output_spend_pending = self.onchain_tx_handler.is_output_spend_pending(&htlc_output_to_spend);
1555
1556                 if let Some(conf_thresh) = holder_delayed_output_pending {
1557                         debug_assert!(holder_commitment);
1558                         return Some(Balance::ClaimableAwaitingConfirmations {
1559                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1560                                 confirmation_height: conf_thresh,
1561                         });
1562                 } else if htlc_resolved.is_some() && !htlc_output_spend_pending {
1563                         // Funding transaction spends should be fully confirmed by the time any
1564                         // HTLC transactions are resolved, unless we're talking about a holder
1565                         // commitment tx, whose resolution is delayed until the CSV timeout is
1566                         // reached, even though HTLCs may be resolved after only
1567                         // ANTI_REORG_DELAY confirmations.
1568                         debug_assert!(holder_commitment || self.funding_spend_confirmed.is_some());
1569                 } else if counterparty_revoked_commitment {
1570                         let htlc_output_claim_pending = self.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1571                                 if let OnchainEvent::MaturingOutput {
1572                                         descriptor: SpendableOutputDescriptor::StaticOutput { .. }
1573                                 } = &event.event {
1574                                         if event.transaction.as_ref().map(|tx| tx.input.iter().any(|inp| {
1575                                                 if let Some(htlc_spend_txid) = htlc_spend_txid_opt {
1576                                                         tx.txid() == *htlc_spend_txid || inp.previous_output.txid == *htlc_spend_txid
1577                                                 } else {
1578                                                         Some(inp.previous_output.txid) == confirmed_txid &&
1579                                                                 inp.previous_output.vout == htlc_commitment_tx_output_idx
1580                                                 }
1581                                         })).unwrap_or(false) {
1582                                                 Some(())
1583                                         } else { None }
1584                                 } else { None }
1585                         });
1586                         if htlc_output_claim_pending.is_some() {
1587                                 // We already push `Balance`s onto the `res` list for every
1588                                 // `StaticOutput` in a `MaturingOutput` in the revoked
1589                                 // counterparty commitment transaction case generally, so don't
1590                                 // need to do so again here.
1591                         } else {
1592                                 debug_assert!(holder_timeout_spend_pending.is_none(),
1593                                         "HTLCUpdate OnchainEvents should never appear for preimage claims");
1594                                 debug_assert!(!htlc.offered || htlc_spend_pending.is_none() || !htlc_spend_pending.unwrap().1,
1595                                         "We don't (currently) generate preimage claims against revoked outputs, where did you get one?!");
1596                                 return Some(Balance::CounterpartyRevokedOutputClaimable {
1597                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1598                                 });
1599                         }
1600                 } else if htlc.offered == holder_commitment {
1601                         // If the payment was outbound, check if there's an HTLCUpdate
1602                         // indicating we have spent this HTLC with a timeout, claiming it back
1603                         // and awaiting confirmations on it.
1604                         if let Some(conf_thresh) = holder_timeout_spend_pending {
1605                                 return Some(Balance::ClaimableAwaitingConfirmations {
1606                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1607                                         confirmation_height: conf_thresh,
1608                                 });
1609                         } else {
1610                                 return Some(Balance::MaybeTimeoutClaimableHTLC {
1611                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1612                                         claimable_height: htlc.cltv_expiry,
1613                                 });
1614                         }
1615                 } else if self.payment_preimages.get(&htlc.payment_hash).is_some() {
1616                         // Otherwise (the payment was inbound), only expose it as claimable if
1617                         // we know the preimage.
1618                         // Note that if there is a pending claim, but it did not use the
1619                         // preimage, we lost funds to our counterparty! We will then continue
1620                         // to show it as ContentiousClaimable until ANTI_REORG_DELAY.
1621                         debug_assert!(holder_timeout_spend_pending.is_none());
1622                         if let Some((conf_thresh, true)) = htlc_spend_pending {
1623                                 return Some(Balance::ClaimableAwaitingConfirmations {
1624                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1625                                         confirmation_height: conf_thresh,
1626                                 });
1627                         } else {
1628                                 return Some(Balance::ContentiousClaimable {
1629                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1630                                         timeout_height: htlc.cltv_expiry,
1631                                 });
1632                         }
1633                 } else if htlc_resolved.is_none() {
1634                         return Some(Balance::MaybePreimageClaimableHTLC {
1635                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1636                                 expiry_height: htlc.cltv_expiry,
1637                         });
1638                 }
1639                 None
1640         }
1641 }
1642
1643 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
1644         /// Gets the balances in this channel which are either claimable by us if we were to
1645         /// force-close the channel now or which are claimable on-chain (possibly awaiting
1646         /// confirmation).
1647         ///
1648         /// Any balances in the channel which are available on-chain (excluding on-chain fees) are
1649         /// included here until an [`Event::SpendableOutputs`] event has been generated for the
1650         /// balance, or until our counterparty has claimed the balance and accrued several
1651         /// confirmations on the claim transaction.
1652         ///
1653         /// Note that for `ChannelMonitors` which track a channel which went on-chain with versions of
1654         /// LDK prior to 0.0.111, balances may not be fully captured if our counterparty broadcasted
1655         /// a revoked state.
1656         ///
1657         /// See [`Balance`] for additional details on the types of claimable balances which
1658         /// may be returned here and their meanings.
1659         pub fn get_claimable_balances(&self) -> Vec<Balance> {
1660                 let mut res = Vec::new();
1661                 let us = self.inner.lock().unwrap();
1662
1663                 let mut confirmed_txid = us.funding_spend_confirmed;
1664                 let mut confirmed_counterparty_output = us.confirmed_commitment_tx_counterparty_output;
1665                 let mut pending_commitment_tx_conf_thresh = None;
1666                 let funding_spend_pending = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1667                         if let OnchainEvent::FundingSpendConfirmation { commitment_tx_to_counterparty_output, .. } =
1668                                 event.event
1669                         {
1670                                 confirmed_counterparty_output = commitment_tx_to_counterparty_output;
1671                                 Some((event.txid, event.confirmation_threshold()))
1672                         } else { None }
1673                 });
1674                 if let Some((txid, conf_thresh)) = funding_spend_pending {
1675                         debug_assert!(us.funding_spend_confirmed.is_none(),
1676                                 "We have a pending funding spend awaiting anti-reorg confirmation, we can't have confirmed it already!");
1677                         confirmed_txid = Some(txid);
1678                         pending_commitment_tx_conf_thresh = Some(conf_thresh);
1679                 }
1680
1681                 macro_rules! walk_htlcs {
1682                         ($holder_commitment: expr, $counterparty_revoked_commitment: expr, $htlc_iter: expr) => {
1683                                 for htlc in $htlc_iter {
1684                                         if htlc.transaction_output_index.is_some() {
1685
1686                                                 if let Some(bal) = us.get_htlc_balance(htlc, $holder_commitment, $counterparty_revoked_commitment, confirmed_txid) {
1687                                                         res.push(bal);
1688                                                 }
1689                                         }
1690                                 }
1691                         }
1692                 }
1693
1694                 if let Some(txid) = confirmed_txid {
1695                         let mut found_commitment_tx = false;
1696                         if let Some(counterparty_tx_htlcs) = us.counterparty_claimable_outpoints.get(&txid) {
1697                                 // First look for the to_remote output back to us.
1698                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1699                                         if let Some(value) = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1700                                                 if let OnchainEvent::MaturingOutput {
1701                                                         descriptor: SpendableOutputDescriptor::StaticPaymentOutput(descriptor)
1702                                                 } = &event.event {
1703                                                         Some(descriptor.output.value)
1704                                                 } else { None }
1705                                         }) {
1706                                                 res.push(Balance::ClaimableAwaitingConfirmations {
1707                                                         claimable_amount_satoshis: value,
1708                                                         confirmation_height: conf_thresh,
1709                                                 });
1710                                         } else {
1711                                                 // If a counterparty commitment transaction is awaiting confirmation, we
1712                                                 // should either have a StaticPaymentOutput MaturingOutput event awaiting
1713                                                 // confirmation with the same height or have never met our dust amount.
1714                                         }
1715                                 }
1716                                 if Some(txid) == us.current_counterparty_commitment_txid || Some(txid) == us.prev_counterparty_commitment_txid {
1717                                         walk_htlcs!(false, false, counterparty_tx_htlcs.iter().map(|(a, _)| a));
1718                                 } else {
1719                                         walk_htlcs!(false, true, counterparty_tx_htlcs.iter().map(|(a, _)| a));
1720                                         // The counterparty broadcasted a revoked state!
1721                                         // Look for any StaticOutputs first, generating claimable balances for those.
1722                                         // If any match the confirmed counterparty revoked to_self output, skip
1723                                         // generating a CounterpartyRevokedOutputClaimable.
1724                                         let mut spent_counterparty_output = false;
1725                                         for event in us.onchain_events_awaiting_threshold_conf.iter() {
1726                                                 if let OnchainEvent::MaturingOutput {
1727                                                         descriptor: SpendableOutputDescriptor::StaticOutput { output, .. }
1728                                                 } = &event.event {
1729                                                         res.push(Balance::ClaimableAwaitingConfirmations {
1730                                                                 claimable_amount_satoshis: output.value,
1731                                                                 confirmation_height: event.confirmation_threshold(),
1732                                                         });
1733                                                         if let Some(confirmed_to_self_idx) = confirmed_counterparty_output.map(|(idx, _)| idx) {
1734                                                                 if event.transaction.as_ref().map(|tx|
1735                                                                         tx.input.iter().any(|inp| inp.previous_output.vout == confirmed_to_self_idx)
1736                                                                 ).unwrap_or(false) {
1737                                                                         spent_counterparty_output = true;
1738                                                                 }
1739                                                         }
1740                                                 }
1741                                         }
1742
1743                                         if spent_counterparty_output {
1744                                         } else if let Some((confirmed_to_self_idx, amt)) = confirmed_counterparty_output {
1745                                                 let output_spendable = us.onchain_tx_handler
1746                                                         .is_output_spend_pending(&BitcoinOutPoint::new(txid, confirmed_to_self_idx));
1747                                                 if output_spendable {
1748                                                         res.push(Balance::CounterpartyRevokedOutputClaimable {
1749                                                                 claimable_amount_satoshis: amt,
1750                                                         });
1751                                                 }
1752                                         } else {
1753                                                 // Counterparty output is missing, either it was broadcasted on a
1754                                                 // previous version of LDK or the counterparty hadn't met dust.
1755                                         }
1756                                 }
1757                                 found_commitment_tx = true;
1758                         } else if txid == us.current_holder_commitment_tx.txid {
1759                                 walk_htlcs!(true, false, us.current_holder_commitment_tx.htlc_outputs.iter().map(|(a, _, _)| a));
1760                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1761                                         res.push(Balance::ClaimableAwaitingConfirmations {
1762                                                 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
1763                                                 confirmation_height: conf_thresh,
1764                                         });
1765                                 }
1766                                 found_commitment_tx = true;
1767                         } else if let Some(prev_commitment) = &us.prev_holder_signed_commitment_tx {
1768                                 if txid == prev_commitment.txid {
1769                                         walk_htlcs!(true, false, prev_commitment.htlc_outputs.iter().map(|(a, _, _)| a));
1770                                         if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1771                                                 res.push(Balance::ClaimableAwaitingConfirmations {
1772                                                         claimable_amount_satoshis: prev_commitment.to_self_value_sat,
1773                                                         confirmation_height: conf_thresh,
1774                                                 });
1775                                         }
1776                                         found_commitment_tx = true;
1777                                 }
1778                         }
1779                         if !found_commitment_tx {
1780                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1781                                         // We blindly assume this is a cooperative close transaction here, and that
1782                                         // neither us nor our counterparty misbehaved. At worst we've under-estimated
1783                                         // the amount we can claim as we'll punish a misbehaving counterparty.
1784                                         res.push(Balance::ClaimableAwaitingConfirmations {
1785                                                 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
1786                                                 confirmation_height: conf_thresh,
1787                                         });
1788                                 }
1789                         }
1790                 } else {
1791                         let mut claimable_inbound_htlc_value_sat = 0;
1792                         for (htlc, _, _) in us.current_holder_commitment_tx.htlc_outputs.iter() {
1793                                 if htlc.transaction_output_index.is_none() { continue; }
1794                                 if htlc.offered {
1795                                         res.push(Balance::MaybeTimeoutClaimableHTLC {
1796                                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1797                                                 claimable_height: htlc.cltv_expiry,
1798                                         });
1799                                 } else if us.payment_preimages.get(&htlc.payment_hash).is_some() {
1800                                         claimable_inbound_htlc_value_sat += htlc.amount_msat / 1000;
1801                                 } else {
1802                                         // As long as the HTLC is still in our latest commitment state, treat
1803                                         // it as potentially claimable, even if it has long-since expired.
1804                                         res.push(Balance::MaybePreimageClaimableHTLC {
1805                                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1806                                                 expiry_height: htlc.cltv_expiry,
1807                                         });
1808                                 }
1809                         }
1810                         res.push(Balance::ClaimableOnChannelClose {
1811                                 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat + claimable_inbound_htlc_value_sat,
1812                         });
1813                 }
1814
1815                 res
1816         }
1817
1818         /// Gets the set of outbound HTLCs which can be (or have been) resolved by this
1819         /// `ChannelMonitor`. This is used to determine if an HTLC was removed from the channel prior
1820         /// to the `ChannelManager` having been persisted.
1821         ///
1822         /// This is similar to [`Self::get_pending_or_resolved_outbound_htlcs`] except it includes
1823         /// HTLCs which were resolved on-chain (i.e. where the final HTLC resolution was done by an
1824         /// event from this `ChannelMonitor`).
1825         pub(crate) fn get_all_current_outbound_htlcs(&self) -> HashMap<HTLCSource, (HTLCOutputInCommitment, Option<PaymentPreimage>)> {
1826                 let mut res = HashMap::new();
1827                 // Just examine the available counterparty commitment transactions. See docs on
1828                 // `fail_unbroadcast_htlcs`, below, for justification.
1829                 let us = self.inner.lock().unwrap();
1830                 macro_rules! walk_counterparty_commitment {
1831                         ($txid: expr) => {
1832                                 if let Some(ref latest_outpoints) = us.counterparty_claimable_outpoints.get($txid) {
1833                                         for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1834                                                 if let &Some(ref source) = source_option {
1835                                                         res.insert((**source).clone(), (htlc.clone(),
1836                                                                 us.counterparty_fulfilled_htlcs.get(&SentHTLCId::from_source(source)).cloned()));
1837                                                 }
1838                                         }
1839                                 }
1840                         }
1841                 }
1842                 if let Some(ref txid) = us.current_counterparty_commitment_txid {
1843                         walk_counterparty_commitment!(txid);
1844                 }
1845                 if let Some(ref txid) = us.prev_counterparty_commitment_txid {
1846                         walk_counterparty_commitment!(txid);
1847                 }
1848                 res
1849         }
1850
1851         /// Gets the set of outbound HTLCs which are pending resolution in this channel or which were
1852         /// resolved with a preimage from our counterparty.
1853         ///
1854         /// This is used to reconstruct pending outbound payments on restart in the ChannelManager.
1855         ///
1856         /// Currently, the preimage is unused, however if it is present in the relevant internal state
1857         /// an HTLC is always included even if it has been resolved.
1858         pub(crate) fn get_pending_or_resolved_outbound_htlcs(&self) -> HashMap<HTLCSource, (HTLCOutputInCommitment, Option<PaymentPreimage>)> {
1859                 let us = self.inner.lock().unwrap();
1860                 // We're only concerned with the confirmation count of HTLC transactions, and don't
1861                 // actually care how many confirmations a commitment transaction may or may not have. Thus,
1862                 // we look for either a FundingSpendConfirmation event or a funding_spend_confirmed.
1863                 let confirmed_txid = us.funding_spend_confirmed.or_else(|| {
1864                         us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1865                                 if let OnchainEvent::FundingSpendConfirmation { .. } = event.event {
1866                                         Some(event.txid)
1867                                 } else { None }
1868                         })
1869                 });
1870
1871                 if confirmed_txid.is_none() {
1872                         // If we have not seen a commitment transaction on-chain (ie the channel is not yet
1873                         // closed), just get the full set.
1874                         mem::drop(us);
1875                         return self.get_all_current_outbound_htlcs();
1876                 }
1877
1878                 let mut res = HashMap::new();
1879                 macro_rules! walk_htlcs {
1880                         ($holder_commitment: expr, $htlc_iter: expr) => {
1881                                 for (htlc, source) in $htlc_iter {
1882                                         if us.htlcs_resolved_on_chain.iter().any(|v| v.commitment_tx_output_idx == htlc.transaction_output_index) {
1883                                                 // We should assert that funding_spend_confirmed is_some() here, but we
1884                                                 // have some unit tests which violate HTLC transaction CSVs entirely and
1885                                                 // would fail.
1886                                                 // TODO: Once tests all connect transactions at consensus-valid times, we
1887                                                 // should assert here like we do in `get_claimable_balances`.
1888                                         } else if htlc.offered == $holder_commitment {
1889                                                 // If the payment was outbound, check if there's an HTLCUpdate
1890                                                 // indicating we have spent this HTLC with a timeout, claiming it back
1891                                                 // and awaiting confirmations on it.
1892                                                 let htlc_update_confd = us.onchain_events_awaiting_threshold_conf.iter().any(|event| {
1893                                                         if let OnchainEvent::HTLCUpdate { commitment_tx_output_idx: Some(commitment_tx_output_idx), .. } = event.event {
1894                                                                 // If the HTLC was timed out, we wait for ANTI_REORG_DELAY blocks
1895                                                                 // before considering it "no longer pending" - this matches when we
1896                                                                 // provide the ChannelManager an HTLC failure event.
1897                                                                 Some(commitment_tx_output_idx) == htlc.transaction_output_index &&
1898                                                                         us.best_block.height() >= event.height + ANTI_REORG_DELAY - 1
1899                                                         } else if let OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, .. } = event.event {
1900                                                                 // If the HTLC was fulfilled with a preimage, we consider the HTLC
1901                                                                 // immediately non-pending, matching when we provide ChannelManager
1902                                                                 // the preimage.
1903                                                                 Some(commitment_tx_output_idx) == htlc.transaction_output_index
1904                                                         } else { false }
1905                                                 });
1906                                                 let counterparty_resolved_preimage_opt =
1907                                                         us.counterparty_fulfilled_htlcs.get(&SentHTLCId::from_source(source)).cloned();
1908                                                 if !htlc_update_confd || counterparty_resolved_preimage_opt.is_some() {
1909                                                         res.insert(source.clone(), (htlc.clone(), counterparty_resolved_preimage_opt));
1910                                                 }
1911                                         }
1912                                 }
1913                         }
1914                 }
1915
1916                 let txid = confirmed_txid.unwrap();
1917                 if Some(txid) == us.current_counterparty_commitment_txid || Some(txid) == us.prev_counterparty_commitment_txid {
1918                         walk_htlcs!(false, us.counterparty_claimable_outpoints.get(&txid).unwrap().iter().filter_map(|(a, b)| {
1919                                 if let &Some(ref source) = b {
1920                                         Some((a, &**source))
1921                                 } else { None }
1922                         }));
1923                 } else if txid == us.current_holder_commitment_tx.txid {
1924                         walk_htlcs!(true, us.current_holder_commitment_tx.htlc_outputs.iter().filter_map(|(a, _, c)| {
1925                                 if let Some(source) = c { Some((a, source)) } else { None }
1926                         }));
1927                 } else if let Some(prev_commitment) = &us.prev_holder_signed_commitment_tx {
1928                         if txid == prev_commitment.txid {
1929                                 walk_htlcs!(true, prev_commitment.htlc_outputs.iter().filter_map(|(a, _, c)| {
1930                                         if let Some(source) = c { Some((a, source)) } else { None }
1931                                 }));
1932                         }
1933                 }
1934
1935                 res
1936         }
1937
1938         pub(crate) fn get_stored_preimages(&self) -> HashMap<PaymentHash, PaymentPreimage> {
1939                 self.inner.lock().unwrap().payment_preimages.clone()
1940         }
1941 }
1942
1943 /// Compares a broadcasted commitment transaction's HTLCs with those in the latest state,
1944 /// failing any HTLCs which didn't make it into the broadcasted commitment transaction back
1945 /// after ANTI_REORG_DELAY blocks.
1946 ///
1947 /// We always compare against the set of HTLCs in counterparty commitment transactions, as those
1948 /// are the commitment transactions which are generated by us. The off-chain state machine in
1949 /// `Channel` will automatically resolve any HTLCs which were never included in a commitment
1950 /// transaction when it detects channel closure, but it is up to us to ensure any HTLCs which were
1951 /// included in a remote commitment transaction are failed back if they are not present in the
1952 /// broadcasted commitment transaction.
1953 ///
1954 /// Specifically, the removal process for HTLCs in `Channel` is always based on the counterparty
1955 /// sending a `revoke_and_ack`, which causes us to clear `prev_counterparty_commitment_txid`. Thus,
1956 /// as long as we examine both the current counterparty commitment transaction and, if it hasn't
1957 /// been revoked yet, the previous one, we we will never "forget" to resolve an HTLC.
1958 macro_rules! fail_unbroadcast_htlcs {
1959         ($self: expr, $commitment_tx_type: expr, $commitment_txid_confirmed: expr, $commitment_tx_confirmed: expr,
1960          $commitment_tx_conf_height: expr, $commitment_tx_conf_hash: expr, $confirmed_htlcs_list: expr, $logger: expr) => { {
1961                 debug_assert_eq!($commitment_tx_confirmed.txid(), $commitment_txid_confirmed);
1962
1963                 macro_rules! check_htlc_fails {
1964                         ($txid: expr, $commitment_tx: expr) => {
1965                                 if let Some(ref latest_outpoints) = $self.counterparty_claimable_outpoints.get($txid) {
1966                                         for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1967                                                 if let &Some(ref source) = source_option {
1968                                                         // Check if the HTLC is present in the commitment transaction that was
1969                                                         // broadcast, but not if it was below the dust limit, which we should
1970                                                         // fail backwards immediately as there is no way for us to learn the
1971                                                         // payment_preimage.
1972                                                         // Note that if the dust limit were allowed to change between
1973                                                         // commitment transactions we'd want to be check whether *any*
1974                                                         // broadcastable commitment transaction has the HTLC in it, but it
1975                                                         // cannot currently change after channel initialization, so we don't
1976                                                         // need to here.
1977                                                         let confirmed_htlcs_iter: &mut Iterator<Item = (&HTLCOutputInCommitment, Option<&HTLCSource>)> = &mut $confirmed_htlcs_list;
1978
1979                                                         let mut matched_htlc = false;
1980                                                         for (ref broadcast_htlc, ref broadcast_source) in confirmed_htlcs_iter {
1981                                                                 if broadcast_htlc.transaction_output_index.is_some() &&
1982                                                                         (Some(&**source) == *broadcast_source ||
1983                                                                          (broadcast_source.is_none() &&
1984                                                                           broadcast_htlc.payment_hash == htlc.payment_hash &&
1985                                                                           broadcast_htlc.amount_msat == htlc.amount_msat)) {
1986                                                                         matched_htlc = true;
1987                                                                         break;
1988                                                                 }
1989                                                         }
1990                                                         if matched_htlc { continue; }
1991                                                         if $self.counterparty_fulfilled_htlcs.get(&SentHTLCId::from_source(source)).is_some() {
1992                                                                 continue;
1993                                                         }
1994                                                         $self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
1995                                                                 if entry.height != $commitment_tx_conf_height { return true; }
1996                                                                 match entry.event {
1997                                                                         OnchainEvent::HTLCUpdate { source: ref update_source, .. } => {
1998                                                                                 *update_source != **source
1999                                                                         },
2000                                                                         _ => true,
2001                                                                 }
2002                                                         });
2003                                                         let entry = OnchainEventEntry {
2004                                                                 txid: $commitment_txid_confirmed,
2005                                                                 transaction: Some($commitment_tx_confirmed.clone()),
2006                                                                 height: $commitment_tx_conf_height,
2007                                                                 block_hash: Some(*$commitment_tx_conf_hash),
2008                                                                 event: OnchainEvent::HTLCUpdate {
2009                                                                         source: (**source).clone(),
2010                                                                         payment_hash: htlc.payment_hash.clone(),
2011                                                                         htlc_value_satoshis: Some(htlc.amount_msat / 1000),
2012                                                                         commitment_tx_output_idx: None,
2013                                                                 },
2014                                                         };
2015                                                         log_trace!($logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of {} commitment transaction {}, waiting for confirmation (at height {})",
2016                                                                 log_bytes!(htlc.payment_hash.0), $commitment_tx, $commitment_tx_type,
2017                                                                 $commitment_txid_confirmed, entry.confirmation_threshold());
2018                                                         $self.onchain_events_awaiting_threshold_conf.push(entry);
2019                                                 }
2020                                         }
2021                                 }
2022                         }
2023                 }
2024                 if let Some(ref txid) = $self.current_counterparty_commitment_txid {
2025                         check_htlc_fails!(txid, "current");
2026                 }
2027                 if let Some(ref txid) = $self.prev_counterparty_commitment_txid {
2028                         check_htlc_fails!(txid, "previous");
2029                 }
2030         } }
2031 }
2032
2033 // In the `test_invalid_funding_tx` test, we need a bogus script which matches the HTLC-Accepted
2034 // witness length match (ie is 136 bytes long). We generate one here which we also use in some
2035 // in-line tests later.
2036
2037 #[cfg(test)]
2038 pub fn deliberately_bogus_accepted_htlc_witness_program() -> Vec<u8> {
2039         let mut ret = [opcodes::all::OP_NOP.to_u8(); 136];
2040         ret[131] = opcodes::all::OP_DROP.to_u8();
2041         ret[132] = opcodes::all::OP_DROP.to_u8();
2042         ret[133] = opcodes::all::OP_DROP.to_u8();
2043         ret[134] = opcodes::all::OP_DROP.to_u8();
2044         ret[135] = opcodes::OP_TRUE.to_u8();
2045         Vec::from(&ret[..])
2046 }
2047
2048 #[cfg(test)]
2049 pub fn deliberately_bogus_accepted_htlc_witness() -> Vec<Vec<u8>> {
2050         vec![Vec::new(), Vec::new(), Vec::new(), Vec::new(), deliberately_bogus_accepted_htlc_witness_program().into()].into()
2051 }
2052
2053 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
2054         /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
2055         /// needed by holder commitment transactions HTCLs nor by counterparty ones. Unless we haven't already seen
2056         /// counterparty commitment transaction's secret, they are de facto pruned (we can use revocation key).
2057         fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), &'static str> {
2058                 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
2059                         return Err("Previous secret did not match new one");
2060                 }
2061
2062                 // Prune HTLCs from the previous counterparty commitment tx so we don't generate failure/fulfill
2063                 // events for now-revoked/fulfilled HTLCs.
2064                 if let Some(txid) = self.prev_counterparty_commitment_txid.take() {
2065                         if self.current_counterparty_commitment_txid.unwrap() != txid {
2066                                 let cur_claimables = self.counterparty_claimable_outpoints.get(
2067                                         &self.current_counterparty_commitment_txid.unwrap()).unwrap();
2068                                 for (_, ref source_opt) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
2069                                         if let Some(source) = source_opt {
2070                                                 if !cur_claimables.iter()
2071                                                         .any(|(_, cur_source_opt)| cur_source_opt == source_opt)
2072                                                 {
2073                                                         self.counterparty_fulfilled_htlcs.remove(&SentHTLCId::from_source(source));
2074                                                 }
2075                                         }
2076                                 }
2077                                 for &mut (_, ref mut source_opt) in self.counterparty_claimable_outpoints.get_mut(&txid).unwrap() {
2078                                         *source_opt = None;
2079                                 }
2080                         } else {
2081                                 assert!(cfg!(fuzzing), "Commitment txids are unique outside of fuzzing, where hashes can collide");
2082                         }
2083                 }
2084
2085                 if !self.payment_preimages.is_empty() {
2086                         let cur_holder_signed_commitment_tx = &self.current_holder_commitment_tx;
2087                         let prev_holder_signed_commitment_tx = self.prev_holder_signed_commitment_tx.as_ref();
2088                         let min_idx = self.get_min_seen_secret();
2089                         let counterparty_hash_commitment_number = &mut self.counterparty_hash_commitment_number;
2090
2091                         self.payment_preimages.retain(|&k, _| {
2092                                 for &(ref htlc, _, _) in cur_holder_signed_commitment_tx.htlc_outputs.iter() {
2093                                         if k == htlc.payment_hash {
2094                                                 return true
2095                                         }
2096                                 }
2097                                 if let Some(prev_holder_commitment_tx) = prev_holder_signed_commitment_tx {
2098                                         for &(ref htlc, _, _) in prev_holder_commitment_tx.htlc_outputs.iter() {
2099                                                 if k == htlc.payment_hash {
2100                                                         return true
2101                                                 }
2102                                         }
2103                                 }
2104                                 let contains = if let Some(cn) = counterparty_hash_commitment_number.get(&k) {
2105                                         if *cn < min_idx {
2106                                                 return true
2107                                         }
2108                                         true
2109                                 } else { false };
2110                                 if contains {
2111                                         counterparty_hash_commitment_number.remove(&k);
2112                                 }
2113                                 false
2114                         });
2115                 }
2116
2117                 Ok(())
2118         }
2119
2120         pub(crate) fn provide_latest_counterparty_commitment_tx<L: Deref>(&mut self, txid: Txid, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>, commitment_number: u64, their_per_commitment_point: PublicKey, logger: &L) where L::Target: Logger {
2121                 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
2122                 // so that a remote monitor doesn't learn anything unless there is a malicious close.
2123                 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
2124                 // timeouts)
2125                 for &(ref htlc, _) in &htlc_outputs {
2126                         self.counterparty_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
2127                 }
2128
2129                 log_trace!(logger, "Tracking new counterparty commitment transaction with txid {} at commitment number {} with {} HTLC outputs", txid, commitment_number, htlc_outputs.len());
2130                 self.prev_counterparty_commitment_txid = self.current_counterparty_commitment_txid.take();
2131                 self.current_counterparty_commitment_txid = Some(txid);
2132                 self.counterparty_claimable_outpoints.insert(txid, htlc_outputs.clone());
2133                 self.current_counterparty_commitment_number = commitment_number;
2134                 //TODO: Merge this into the other per-counterparty-transaction output storage stuff
2135                 match self.their_cur_per_commitment_points {
2136                         Some(old_points) => {
2137                                 if old_points.0 == commitment_number + 1 {
2138                                         self.their_cur_per_commitment_points = Some((old_points.0, old_points.1, Some(their_per_commitment_point)));
2139                                 } else if old_points.0 == commitment_number + 2 {
2140                                         if let Some(old_second_point) = old_points.2 {
2141                                                 self.their_cur_per_commitment_points = Some((old_points.0 - 1, old_second_point, Some(their_per_commitment_point)));
2142                                         } else {
2143                                                 self.their_cur_per_commitment_points = Some((commitment_number, their_per_commitment_point, None));
2144                                         }
2145                                 } else {
2146                                         self.their_cur_per_commitment_points = Some((commitment_number, their_per_commitment_point, None));
2147                                 }
2148                         },
2149                         None => {
2150                                 self.their_cur_per_commitment_points = Some((commitment_number, their_per_commitment_point, None));
2151                         }
2152                 }
2153                 let mut htlcs = Vec::with_capacity(htlc_outputs.len());
2154                 for htlc in htlc_outputs {
2155                         if htlc.0.transaction_output_index.is_some() {
2156                                 htlcs.push(htlc.0);
2157                         }
2158                 }
2159         }
2160
2161         /// Informs this monitor of the latest holder (ie broadcastable) commitment transaction. The
2162         /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
2163         /// is important that any clones of this channel monitor (including remote clones) by kept
2164         /// up-to-date as our holder commitment transaction is updated.
2165         /// Panics if set_on_holder_tx_csv has never been called.
2166         fn provide_latest_holder_commitment_tx(&mut self, holder_commitment_tx: HolderCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>, claimed_htlcs: &[(SentHTLCId, PaymentPreimage)]) -> Result<(), &'static str> {
2167                 let trusted_tx = holder_commitment_tx.trust();
2168                 let txid = trusted_tx.txid();
2169                 let tx_keys = trusted_tx.keys();
2170                 self.current_holder_commitment_number = trusted_tx.commitment_number();
2171                 let mut new_holder_commitment_tx = HolderSignedTx {
2172                         txid,
2173                         revocation_key: tx_keys.revocation_key,
2174                         a_htlc_key: tx_keys.broadcaster_htlc_key,
2175                         b_htlc_key: tx_keys.countersignatory_htlc_key,
2176                         delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
2177                         per_commitment_point: tx_keys.per_commitment_point,
2178                         htlc_outputs,
2179                         to_self_value_sat: holder_commitment_tx.to_broadcaster_value_sat(),
2180                         feerate_per_kw: trusted_tx.feerate_per_kw(),
2181                 };
2182                 self.onchain_tx_handler.provide_latest_holder_tx(holder_commitment_tx);
2183                 mem::swap(&mut new_holder_commitment_tx, &mut self.current_holder_commitment_tx);
2184                 self.prev_holder_signed_commitment_tx = Some(new_holder_commitment_tx);
2185                 for (claimed_htlc_id, claimed_preimage) in claimed_htlcs {
2186                         #[cfg(debug_assertions)] {
2187                                 let cur_counterparty_htlcs = self.counterparty_claimable_outpoints.get(
2188                                                 &self.current_counterparty_commitment_txid.unwrap()).unwrap();
2189                                 assert!(cur_counterparty_htlcs.iter().any(|(_, source_opt)| {
2190                                         if let Some(source) = source_opt {
2191                                                 SentHTLCId::from_source(source) == *claimed_htlc_id
2192                                         } else { false }
2193                                 }));
2194                         }
2195                         self.counterparty_fulfilled_htlcs.insert(*claimed_htlc_id, *claimed_preimage);
2196                 }
2197                 if self.holder_tx_signed {
2198                         return Err("Latest holder commitment signed has already been signed, update is rejected");
2199                 }
2200                 Ok(())
2201         }
2202
2203         /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
2204         /// commitment_tx_infos which contain the payment hash have been revoked.
2205         fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(
2206                 &mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage, broadcaster: &B,
2207                 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L)
2208         where B::Target: BroadcasterInterface,
2209                     F::Target: FeeEstimator,
2210                     L::Target: Logger,
2211         {
2212                 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
2213
2214                 // If the channel is force closed, try to claim the output from this preimage.
2215                 // First check if a counterparty commitment transaction has been broadcasted:
2216                 macro_rules! claim_htlcs {
2217                         ($commitment_number: expr, $txid: expr) => {
2218                                 let (htlc_claim_reqs, _) = self.get_counterparty_output_claim_info($commitment_number, $txid, None);
2219                                 self.onchain_tx_handler.update_claims_view_from_requests(htlc_claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
2220                         }
2221                 }
2222                 if let Some(txid) = self.current_counterparty_commitment_txid {
2223                         if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
2224                                 claim_htlcs!(*commitment_number, txid);
2225                                 return;
2226                         }
2227                 }
2228                 if let Some(txid) = self.prev_counterparty_commitment_txid {
2229                         if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
2230                                 claim_htlcs!(*commitment_number, txid);
2231                                 return;
2232                         }
2233                 }
2234
2235                 // Then if a holder commitment transaction has been seen on-chain, broadcast transactions
2236                 // claiming the HTLC output from each of the holder commitment transactions.
2237                 // Note that we can't just use `self.holder_tx_signed`, because that only covers the case where
2238                 // *we* sign a holder commitment transaction, not when e.g. a watchtower broadcasts one of our
2239                 // holder commitment transactions.
2240                 if self.broadcasted_holder_revokable_script.is_some() {
2241                         // Assume that the broadcasted commitment transaction confirmed in the current best
2242                         // block. Even if not, its a reasonable metric for the bump criteria on the HTLC
2243                         // transactions.
2244                         let (claim_reqs, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
2245                         self.onchain_tx_handler.update_claims_view_from_requests(claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
2246                         if let Some(ref tx) = self.prev_holder_signed_commitment_tx {
2247                                 let (claim_reqs, _) = self.get_broadcasted_holder_claims(&tx, self.best_block.height());
2248                                 self.onchain_tx_handler.update_claims_view_from_requests(claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
2249                         }
2250                 }
2251         }
2252
2253         pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
2254                 where B::Target: BroadcasterInterface,
2255                                         L::Target: Logger,
2256         {
2257                 for tx in self.get_latest_holder_commitment_txn(logger).iter() {
2258                         log_info!(logger, "Broadcasting local {}", log_tx!(tx));
2259                         broadcaster.broadcast_transaction(tx);
2260                 }
2261                 self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
2262         }
2263
2264         pub fn update_monitor<B: Deref, F: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: F, logger: &L) -> Result<(), ()>
2265         where B::Target: BroadcasterInterface,
2266                 F::Target: FeeEstimator,
2267                 L::Target: Logger,
2268         {
2269                 log_info!(logger, "Applying update to monitor {}, bringing update_id from {} to {} with {} changes.",
2270                         log_funding_info!(self), self.latest_update_id, updates.update_id, updates.updates.len());
2271                 // ChannelMonitor updates may be applied after force close if we receive a
2272                 // preimage for a broadcasted commitment transaction HTLC output that we'd
2273                 // like to claim on-chain. If this is the case, we no longer have guaranteed
2274                 // access to the monitor's update ID, so we use a sentinel value instead.
2275                 if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
2276                         assert_eq!(updates.updates.len(), 1);
2277                         match updates.updates[0] {
2278                                 ChannelMonitorUpdateStep::ChannelForceClosed { .. } => {},
2279                                 // We should have already seen a `ChannelForceClosed` update if we're trying to
2280                                 // provide a preimage at this point.
2281                                 ChannelMonitorUpdateStep::PaymentPreimage { .. } =>
2282                                         debug_assert_eq!(self.latest_update_id, CLOSED_CHANNEL_UPDATE_ID),
2283                                 _ => {
2284                                         log_error!(logger, "Attempted to apply post-force-close ChannelMonitorUpdate of type {}", updates.updates[0].variant_name());
2285                                         panic!("Attempted to apply post-force-close ChannelMonitorUpdate that wasn't providing a payment preimage");
2286                                 },
2287                         }
2288                 } else if self.latest_update_id + 1 != updates.update_id {
2289                         panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
2290                 }
2291                 let mut ret = Ok(());
2292                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&*fee_estimator);
2293                 for update in updates.updates.iter() {
2294                         match update {
2295                                 ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs, claimed_htlcs } => {
2296                                         log_trace!(logger, "Updating ChannelMonitor with latest holder commitment transaction info");
2297                                         if self.lockdown_from_offchain { panic!(); }
2298                                         if let Err(e) = self.provide_latest_holder_commitment_tx(commitment_tx.clone(), htlc_outputs.clone(), &claimed_htlcs) {
2299                                                 log_error!(logger, "Providing latest holder commitment transaction failed/was refused:");
2300                                                 log_error!(logger, "    {}", e);
2301                                                 ret = Err(());
2302                                         }
2303                                 }
2304                                 ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid, htlc_outputs, commitment_number, their_per_commitment_point } => {
2305                                         log_trace!(logger, "Updating ChannelMonitor with latest counterparty commitment transaction info");
2306                                         self.provide_latest_counterparty_commitment_tx(*commitment_txid, htlc_outputs.clone(), *commitment_number, *their_per_commitment_point, logger)
2307                                 },
2308                                 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } => {
2309                                         log_trace!(logger, "Updating ChannelMonitor with payment preimage");
2310                                         self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage, broadcaster, &bounded_fee_estimator, logger)
2311                                 },
2312                                 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } => {
2313                                         log_trace!(logger, "Updating ChannelMonitor with commitment secret");
2314                                         if let Err(e) = self.provide_secret(*idx, *secret) {
2315                                                 log_error!(logger, "Providing latest counterparty commitment secret failed/was refused:");
2316                                                 log_error!(logger, "    {}", e);
2317                                                 ret = Err(());
2318                                         }
2319                                 },
2320                                 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
2321                                         log_trace!(logger, "Updating ChannelMonitor: channel force closed, should broadcast: {}", should_broadcast);
2322                                         self.lockdown_from_offchain = true;
2323                                         if *should_broadcast {
2324                                                 // There's no need to broadcast our commitment transaction if we've seen one
2325                                                 // confirmed (even with 1 confirmation) as it'll be rejected as
2326                                                 // duplicate/conflicting.
2327                                                 let detected_funding_spend = self.funding_spend_confirmed.is_some() ||
2328                                                         self.onchain_events_awaiting_threshold_conf.iter().find(|event| match event.event {
2329                                                                 OnchainEvent::FundingSpendConfirmation { .. } => true,
2330                                                                 _ => false,
2331                                                         }).is_some();
2332                                                 if detected_funding_spend {
2333                                                         continue;
2334                                                 }
2335                                                 self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
2336                                                 // If the channel supports anchor outputs, we'll need to emit an external
2337                                                 // event to be consumed such that a child transaction is broadcast with a
2338                                                 // high enough feerate for the parent commitment transaction to confirm.
2339                                                 if self.onchain_tx_handler.opt_anchors() {
2340                                                         let funding_output = HolderFundingOutput::build(
2341                                                                 self.funding_redeemscript.clone(), self.channel_value_satoshis,
2342                                                                 self.onchain_tx_handler.opt_anchors(),
2343                                                         );
2344                                                         let best_block_height = self.best_block.height();
2345                                                         let commitment_package = PackageTemplate::build_package(
2346                                                                 self.funding_info.0.txid.clone(), self.funding_info.0.index as u32,
2347                                                                 PackageSolvingData::HolderFundingOutput(funding_output),
2348                                                                 best_block_height, false, best_block_height,
2349                                                         );
2350                                                         self.onchain_tx_handler.update_claims_view_from_requests(
2351                                                                 vec![commitment_package], best_block_height, best_block_height,
2352                                                                 broadcaster, &bounded_fee_estimator, logger,
2353                                                         );
2354                                                 }
2355                                         } else if !self.holder_tx_signed {
2356                                                 log_error!(logger, "WARNING: You have a potentially-unsafe holder commitment transaction available to broadcast");
2357                                                 log_error!(logger, "    in channel monitor for channel {}!", log_bytes!(self.funding_info.0.to_channel_id()));
2358                                                 log_error!(logger, "    Read the docs for ChannelMonitor::get_latest_holder_commitment_txn and take manual action!");
2359                                         } else {
2360                                                 // If we generated a MonitorEvent::CommitmentTxConfirmed, the ChannelManager
2361                                                 // will still give us a ChannelForceClosed event with !should_broadcast, but we
2362                                                 // shouldn't print the scary warning above.
2363                                                 log_info!(logger, "Channel off-chain state closed after we broadcasted our latest commitment transaction.");
2364                                         }
2365                                 },
2366                                 ChannelMonitorUpdateStep::ShutdownScript { scriptpubkey } => {
2367                                         log_trace!(logger, "Updating ChannelMonitor with shutdown script");
2368                                         if let Some(shutdown_script) = self.shutdown_script.replace(scriptpubkey.clone()) {
2369                                                 panic!("Attempted to replace shutdown script {} with {}", shutdown_script, scriptpubkey);
2370                                         }
2371                                 },
2372                         }
2373                 }
2374                 self.latest_update_id = updates.update_id;
2375
2376                 if ret.is_ok() && self.funding_spend_seen {
2377                         log_error!(logger, "Refusing Channel Monitor Update as counterparty attempted to update commitment after funding was spent");
2378                         Err(())
2379                 } else { ret }
2380         }
2381
2382         pub fn get_latest_update_id(&self) -> u64 {
2383                 self.latest_update_id
2384         }
2385
2386         pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
2387                 &self.funding_info
2388         }
2389
2390         pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<(u32, Script)>> {
2391                 // If we've detected a counterparty commitment tx on chain, we must include it in the set
2392                 // of outputs to watch for spends of, otherwise we're likely to lose user funds. Because
2393                 // its trivial to do, double-check that here.
2394                 for (txid, _) in self.counterparty_commitment_txn_on_chain.iter() {
2395                         self.outputs_to_watch.get(txid).expect("Counterparty commitment txn which have been broadcast should have outputs registered");
2396                 }
2397                 &self.outputs_to_watch
2398         }
2399
2400         pub fn get_and_clear_pending_monitor_events(&mut self) -> Vec<MonitorEvent> {
2401                 let mut ret = Vec::new();
2402                 mem::swap(&mut ret, &mut self.pending_monitor_events);
2403                 ret
2404         }
2405
2406         pub fn get_and_clear_pending_events(&mut self) -> Vec<Event> {
2407                 let mut ret = Vec::new();
2408                 mem::swap(&mut ret, &mut self.pending_events);
2409                 #[cfg(anchors)]
2410                 for claim_event in self.onchain_tx_handler.get_and_clear_pending_claim_events().drain(..) {
2411                         match claim_event {
2412                                 ClaimEvent::BumpCommitment {
2413                                         package_target_feerate_sat_per_1000_weight, commitment_tx, anchor_output_idx,
2414                                 } => {
2415                                         let commitment_txid = commitment_tx.txid();
2416                                         debug_assert_eq!(self.current_holder_commitment_tx.txid, commitment_txid);
2417                                         let pending_htlcs = self.current_holder_commitment_tx.non_dust_htlcs();
2418                                         let commitment_tx_fee_satoshis = self.channel_value_satoshis -
2419                                                 commitment_tx.output.iter().fold(0u64, |sum, output| sum + output.value);
2420                                         ret.push(Event::BumpTransaction(BumpTransactionEvent::ChannelClose {
2421                                                 package_target_feerate_sat_per_1000_weight,
2422                                                 commitment_tx,
2423                                                 commitment_tx_fee_satoshis,
2424                                                 anchor_descriptor: AnchorDescriptor {
2425                                                         channel_keys_id: self.channel_keys_id,
2426                                                         channel_value_satoshis: self.channel_value_satoshis,
2427                                                         outpoint: BitcoinOutPoint {
2428                                                                 txid: commitment_txid,
2429                                                                 vout: anchor_output_idx,
2430                                                         },
2431                                                 },
2432                                                 pending_htlcs,
2433                                         }));
2434                                 },
2435                                 ClaimEvent::BumpHTLC {
2436                                         target_feerate_sat_per_1000_weight, htlcs,
2437                                 } => {
2438                                         let mut htlc_descriptors = Vec::with_capacity(htlcs.len());
2439                                         for htlc in htlcs {
2440                                                 htlc_descriptors.push(HTLCDescriptor {
2441                                                         channel_keys_id: self.channel_keys_id,
2442                                                         channel_value_satoshis: self.channel_value_satoshis,
2443                                                         channel_parameters: self.onchain_tx_handler.channel_transaction_parameters.clone(),
2444                                                         commitment_txid: htlc.commitment_txid,
2445                                                         per_commitment_number: htlc.per_commitment_number,
2446                                                         htlc: htlc.htlc,
2447                                                         preimage: htlc.preimage,
2448                                                         counterparty_sig: htlc.counterparty_sig,
2449                                                 });
2450                                         }
2451                                         ret.push(Event::BumpTransaction(BumpTransactionEvent::HTLCResolution {
2452                                                 target_feerate_sat_per_1000_weight,
2453                                                 htlc_descriptors,
2454                                         }));
2455                                 }
2456                         }
2457                 }
2458                 ret
2459         }
2460
2461         /// Can only fail if idx is < get_min_seen_secret
2462         fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
2463                 self.commitment_secrets.get_secret(idx)
2464         }
2465
2466         pub(crate) fn get_min_seen_secret(&self) -> u64 {
2467                 self.commitment_secrets.get_min_seen_secret()
2468         }
2469
2470         pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
2471                 self.current_counterparty_commitment_number
2472         }
2473
2474         pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
2475                 self.current_holder_commitment_number
2476         }
2477
2478         /// Attempts to claim a counterparty commitment transaction's outputs using the revocation key and
2479         /// data in counterparty_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
2480         /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
2481         /// HTLC-Success/HTLC-Timeout transactions.
2482         ///
2483         /// Returns packages to claim the revoked output(s), as well as additional outputs to watch and
2484         /// general information about the output that is to the counterparty in the commitment
2485         /// transaction.
2486         fn check_spend_counterparty_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, block_hash: &BlockHash, logger: &L)
2487                 -> (Vec<PackageTemplate>, TransactionOutputs, CommitmentTxCounterpartyOutputInfo)
2488         where L::Target: Logger {
2489                 // Most secp and related errors trying to create keys means we have no hope of constructing
2490                 // a spend transaction...so we return no transactions to broadcast
2491                 let mut claimable_outpoints = Vec::new();
2492                 let mut watch_outputs = Vec::new();
2493                 let mut to_counterparty_output_info = None;
2494
2495                 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
2496                 let per_commitment_option = self.counterparty_claimable_outpoints.get(&commitment_txid);
2497
2498                 macro_rules! ignore_error {
2499                         ( $thing : expr ) => {
2500                                 match $thing {
2501                                         Ok(a) => a,
2502                                         Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs), to_counterparty_output_info)
2503                                 }
2504                         };
2505                 }
2506
2507                 let commitment_number = 0xffffffffffff - ((((tx.input[0].sequence.0 as u64 & 0xffffff) << 3*8) | (tx.lock_time.0 as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor);
2508                 if commitment_number >= self.get_min_seen_secret() {
2509                         let secret = self.get_secret(commitment_number).unwrap();
2510                         let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
2511                         let per_commitment_point = PublicKey::from_secret_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_key);
2512                         let revocation_pubkey = chan_utils::derive_public_revocation_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint);
2513                         let delayed_key = chan_utils::derive_public_key(&self.onchain_tx_handler.secp_ctx, &PublicKey::from_secret_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_key), &self.counterparty_commitment_params.counterparty_delayed_payment_base_key);
2514
2515                         let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.counterparty_commitment_params.on_counterparty_tx_csv, &delayed_key);
2516                         let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
2517
2518                         // First, process non-htlc outputs (to_holder & to_counterparty)
2519                         for (idx, outp) in tx.output.iter().enumerate() {
2520                                 if outp.script_pubkey == revokeable_p2wsh {
2521                                         let revk_outp = RevokedOutput::build(per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key, self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key, outp.value, self.counterparty_commitment_params.on_counterparty_tx_csv);
2522                                         let justice_package = PackageTemplate::build_package(commitment_txid, idx as u32, PackageSolvingData::RevokedOutput(revk_outp), height + self.counterparty_commitment_params.on_counterparty_tx_csv as u32, true, height);
2523                                         claimable_outpoints.push(justice_package);
2524                                         to_counterparty_output_info =
2525                                                 Some((idx.try_into().expect("Txn can't have more than 2^32 outputs"), outp.value));
2526                                 }
2527                         }
2528
2529                         // Then, try to find revoked htlc outputs
2530                         if let Some(ref per_commitment_data) = per_commitment_option {
2531                                 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
2532                                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2533                                                 if transaction_output_index as usize >= tx.output.len() ||
2534                                                                 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
2535                                                         // per_commitment_data is corrupt or our commitment signing key leaked!
2536                                                         return (claimable_outpoints, (commitment_txid, watch_outputs),
2537                                                                 to_counterparty_output_info);
2538                                                 }
2539                                                 let revk_htlc_outp = RevokedHTLCOutput::build(per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key, self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key, htlc.amount_msat / 1000, htlc.clone(), self.onchain_tx_handler.channel_transaction_parameters.opt_anchors.is_some());
2540                                                 let justice_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, PackageSolvingData::RevokedHTLCOutput(revk_htlc_outp), htlc.cltv_expiry, true, height);
2541                                                 claimable_outpoints.push(justice_package);
2542                                         }
2543                                 }
2544                         }
2545
2546                         // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
2547                         if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
2548                                 // We're definitely a counterparty commitment transaction!
2549                                 log_error!(logger, "Got broadcast of revoked counterparty commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
2550                                 for (idx, outp) in tx.output.iter().enumerate() {
2551                                         watch_outputs.push((idx as u32, outp.clone()));
2552                                 }
2553                                 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
2554
2555                                 if let Some(per_commitment_data) = per_commitment_option {
2556                                         fail_unbroadcast_htlcs!(self, "revoked_counterparty", commitment_txid, tx, height,
2557                                                 block_hash, per_commitment_data.iter().map(|(htlc, htlc_source)|
2558                                                         (htlc, htlc_source.as_ref().map(|htlc_source| htlc_source.as_ref()))
2559                                                 ), logger);
2560                                 } else {
2561                                         debug_assert!(false, "We should have per-commitment option for any recognized old commitment txn");
2562                                         fail_unbroadcast_htlcs!(self, "revoked counterparty", commitment_txid, tx, height,
2563                                                 block_hash, [].iter().map(|reference| *reference), logger);
2564                                 }
2565                         }
2566                 } else if let Some(per_commitment_data) = per_commitment_option {
2567                         // While this isn't useful yet, there is a potential race where if a counterparty
2568                         // revokes a state at the same time as the commitment transaction for that state is
2569                         // confirmed, and the watchtower receives the block before the user, the user could
2570                         // upload a new ChannelMonitor with the revocation secret but the watchtower has
2571                         // already processed the block, resulting in the counterparty_commitment_txn_on_chain entry
2572                         // not being generated by the above conditional. Thus, to be safe, we go ahead and
2573                         // insert it here.
2574                         for (idx, outp) in tx.output.iter().enumerate() {
2575                                 watch_outputs.push((idx as u32, outp.clone()));
2576                         }
2577                         self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
2578
2579                         log_info!(logger, "Got broadcast of non-revoked counterparty commitment transaction {}", commitment_txid);
2580                         fail_unbroadcast_htlcs!(self, "counterparty", commitment_txid, tx, height, block_hash,
2581                                 per_commitment_data.iter().map(|(htlc, htlc_source)|
2582                                         (htlc, htlc_source.as_ref().map(|htlc_source| htlc_source.as_ref()))
2583                                 ), logger);
2584
2585                         let (htlc_claim_reqs, counterparty_output_info) =
2586                                 self.get_counterparty_output_claim_info(commitment_number, commitment_txid, Some(tx));
2587                         to_counterparty_output_info = counterparty_output_info;
2588                         for req in htlc_claim_reqs {
2589                                 claimable_outpoints.push(req);
2590                         }
2591
2592                 }
2593                 (claimable_outpoints, (commitment_txid, watch_outputs), to_counterparty_output_info)
2594         }
2595
2596         /// Returns the HTLC claim package templates and the counterparty output info
2597         fn get_counterparty_output_claim_info(&self, commitment_number: u64, commitment_txid: Txid, tx: Option<&Transaction>)
2598         -> (Vec<PackageTemplate>, CommitmentTxCounterpartyOutputInfo) {
2599                 let mut claimable_outpoints = Vec::new();
2600                 let mut to_counterparty_output_info: CommitmentTxCounterpartyOutputInfo = None;
2601
2602                 let htlc_outputs = match self.counterparty_claimable_outpoints.get(&commitment_txid) {
2603                         Some(outputs) => outputs,
2604                         None => return (claimable_outpoints, to_counterparty_output_info),
2605                 };
2606                 let per_commitment_points = match self.their_cur_per_commitment_points {
2607                         Some(points) => points,
2608                         None => return (claimable_outpoints, to_counterparty_output_info),
2609                 };
2610
2611                 let per_commitment_point =
2612                         // If the counterparty commitment tx is the latest valid state, use their latest
2613                         // per-commitment point
2614                         if per_commitment_points.0 == commitment_number { &per_commitment_points.1 }
2615                         else if let Some(point) = per_commitment_points.2.as_ref() {
2616                                 // If counterparty commitment tx is the state previous to the latest valid state, use
2617                                 // their previous per-commitment point (non-atomicity of revocation means it's valid for
2618                                 // them to temporarily have two valid commitment txns from our viewpoint)
2619                                 if per_commitment_points.0 == commitment_number + 1 {
2620                                         point
2621                                 } else { return (claimable_outpoints, to_counterparty_output_info); }
2622                         } else { return (claimable_outpoints, to_counterparty_output_info); };
2623
2624                 if let Some(transaction) = tx {
2625                         let revocation_pubkey = chan_utils::derive_public_revocation_key(
2626                                 &self.onchain_tx_handler.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint);
2627                         let delayed_key = chan_utils::derive_public_key(&self.onchain_tx_handler.secp_ctx,
2628                                 &per_commitment_point,
2629                                 &self.counterparty_commitment_params.counterparty_delayed_payment_base_key);
2630                         let revokeable_p2wsh = chan_utils::get_revokeable_redeemscript(&revocation_pubkey,
2631                                 self.counterparty_commitment_params.on_counterparty_tx_csv,
2632                                 &delayed_key).to_v0_p2wsh();
2633                         for (idx, outp) in transaction.output.iter().enumerate() {
2634                                 if outp.script_pubkey == revokeable_p2wsh {
2635                                         to_counterparty_output_info =
2636                                                 Some((idx.try_into().expect("Can't have > 2^32 outputs"), outp.value));
2637                                 }
2638                         }
2639                 }
2640
2641                 for (_, &(ref htlc, _)) in htlc_outputs.iter().enumerate() {
2642                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2643                                 if let Some(transaction) = tx {
2644                                         if transaction_output_index as usize >= transaction.output.len() ||
2645                                                 transaction.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
2646                                                         // per_commitment_data is corrupt or our commitment signing key leaked!
2647                                                         return (claimable_outpoints, to_counterparty_output_info);
2648                                                 }
2649                                 }
2650                                 let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
2651                                 if preimage.is_some() || !htlc.offered {
2652                                         let counterparty_htlc_outp = if htlc.offered {
2653                                                 PackageSolvingData::CounterpartyOfferedHTLCOutput(
2654                                                         CounterpartyOfferedHTLCOutput::build(*per_commitment_point,
2655                                                                 self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
2656                                                                 self.counterparty_commitment_params.counterparty_htlc_base_key,
2657                                                                 preimage.unwrap(), htlc.clone(), self.onchain_tx_handler.opt_anchors()))
2658                                         } else {
2659                                                 PackageSolvingData::CounterpartyReceivedHTLCOutput(
2660                                                         CounterpartyReceivedHTLCOutput::build(*per_commitment_point,
2661                                                                 self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
2662                                                                 self.counterparty_commitment_params.counterparty_htlc_base_key,
2663                                                                 htlc.clone(), self.onchain_tx_handler.opt_anchors()))
2664                                         };
2665                                         let aggregation = if !htlc.offered { false } else { true };
2666                                         let counterparty_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, counterparty_htlc_outp, htlc.cltv_expiry,aggregation, 0);
2667                                         claimable_outpoints.push(counterparty_package);
2668                                 }
2669                         }
2670                 }
2671
2672                 (claimable_outpoints, to_counterparty_output_info)
2673         }
2674
2675         /// Attempts to claim a counterparty HTLC-Success/HTLC-Timeout's outputs using the revocation key
2676         fn check_spend_counterparty_htlc<L: Deref>(
2677                 &mut self, tx: &Transaction, commitment_number: u64, commitment_txid: &Txid, height: u32, logger: &L
2678         ) -> (Vec<PackageTemplate>, Option<TransactionOutputs>) where L::Target: Logger {
2679                 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
2680                 let per_commitment_key = match SecretKey::from_slice(&secret) {
2681                         Ok(key) => key,
2682                         Err(_) => return (Vec::new(), None)
2683                 };
2684                 let per_commitment_point = PublicKey::from_secret_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_key);
2685
2686                 let htlc_txid = tx.txid();
2687                 let mut claimable_outpoints = vec![];
2688                 let mut outputs_to_watch = None;
2689                 // Previously, we would only claim HTLCs from revoked HTLC transactions if they had 1 input
2690                 // with a witness of 5 elements and 1 output. This wasn't enough for anchor outputs, as the
2691                 // counterparty can now aggregate multiple HTLCs into a single transaction thanks to
2692                 // `SIGHASH_SINGLE` remote signatures, leading us to not claim any HTLCs upon seeing a
2693                 // confirmed revoked HTLC transaction (for more details, see
2694                 // https://lists.linuxfoundation.org/pipermail/lightning-dev/2022-April/003561.html).
2695                 //
2696                 // We make sure we're not vulnerable to this case by checking all inputs of the transaction,
2697                 // and claim those which spend the commitment transaction, have a witness of 5 elements, and
2698                 // have a corresponding output at the same index within the transaction.
2699                 for (idx, input) in tx.input.iter().enumerate() {
2700                         if input.previous_output.txid == *commitment_txid && input.witness.len() == 5 && tx.output.get(idx).is_some() {
2701                                 log_error!(logger, "Got broadcast of revoked counterparty HTLC transaction, spending {}:{}", htlc_txid, idx);
2702                                 let revk_outp = RevokedOutput::build(
2703                                         per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
2704                                         self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key,
2705                                         tx.output[idx].value, self.counterparty_commitment_params.on_counterparty_tx_csv
2706                                 );
2707                                 let justice_package = PackageTemplate::build_package(
2708                                         htlc_txid, idx as u32, PackageSolvingData::RevokedOutput(revk_outp),
2709                                         height + self.counterparty_commitment_params.on_counterparty_tx_csv as u32, true, height
2710                                 );
2711                                 claimable_outpoints.push(justice_package);
2712                                 if outputs_to_watch.is_none() {
2713                                         outputs_to_watch = Some((htlc_txid, vec![]));
2714                                 }
2715                                 outputs_to_watch.as_mut().unwrap().1.push((idx as u32, tx.output[idx].clone()));
2716                         }
2717                 }
2718                 (claimable_outpoints, outputs_to_watch)
2719         }
2720
2721         // Returns (1) `PackageTemplate`s that can be given to the OnchainTxHandler, so that the handler can
2722         // broadcast transactions claiming holder HTLC commitment outputs and (2) a holder revokable
2723         // script so we can detect whether a holder transaction has been seen on-chain.
2724         fn get_broadcasted_holder_claims(&self, holder_tx: &HolderSignedTx, conf_height: u32) -> (Vec<PackageTemplate>, Option<(Script, PublicKey, PublicKey)>) {
2725                 let mut claim_requests = Vec::with_capacity(holder_tx.htlc_outputs.len());
2726
2727                 let redeemscript = chan_utils::get_revokeable_redeemscript(&holder_tx.revocation_key, self.on_holder_tx_csv, &holder_tx.delayed_payment_key);
2728                 let broadcasted_holder_revokable_script = Some((redeemscript.to_v0_p2wsh(), holder_tx.per_commitment_point.clone(), holder_tx.revocation_key.clone()));
2729
2730                 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
2731                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2732                                 let (htlc_output, aggregable) = if htlc.offered {
2733                                         let htlc_output = HolderHTLCOutput::build_offered(
2734                                                 htlc.amount_msat, htlc.cltv_expiry, self.onchain_tx_handler.opt_anchors()
2735                                         );
2736                                         (htlc_output, false)
2737                                 } else {
2738                                         let payment_preimage = if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
2739                                                 preimage.clone()
2740                                         } else {
2741                                                 // We can't build an HTLC-Success transaction without the preimage
2742                                                 continue;
2743                                         };
2744                                         let htlc_output = HolderHTLCOutput::build_accepted(
2745                                                 payment_preimage, htlc.amount_msat, self.onchain_tx_handler.opt_anchors()
2746                                         );
2747                                         (htlc_output, self.onchain_tx_handler.opt_anchors())
2748                                 };
2749                                 let htlc_package = PackageTemplate::build_package(
2750                                         holder_tx.txid, transaction_output_index,
2751                                         PackageSolvingData::HolderHTLCOutput(htlc_output),
2752                                         htlc.cltv_expiry, aggregable, conf_height
2753                                 );
2754                                 claim_requests.push(htlc_package);
2755                         }
2756                 }
2757
2758                 (claim_requests, broadcasted_holder_revokable_script)
2759         }
2760
2761         // Returns holder HTLC outputs to watch and react to in case of spending.
2762         fn get_broadcasted_holder_watch_outputs(&self, holder_tx: &HolderSignedTx, commitment_tx: &Transaction) -> Vec<(u32, TxOut)> {
2763                 let mut watch_outputs = Vec::with_capacity(holder_tx.htlc_outputs.len());
2764                 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
2765                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2766                                 watch_outputs.push((transaction_output_index, commitment_tx.output[transaction_output_index as usize].clone()));
2767                         }
2768                 }
2769                 watch_outputs
2770         }
2771
2772         /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
2773         /// revoked using data in holder_claimable_outpoints.
2774         /// Should not be used if check_spend_revoked_transaction succeeds.
2775         /// Returns None unless the transaction is definitely one of our commitment transactions.
2776         fn check_spend_holder_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, block_hash: &BlockHash, logger: &L) -> Option<(Vec<PackageTemplate>, TransactionOutputs)> where L::Target: Logger {
2777                 let commitment_txid = tx.txid();
2778                 let mut claim_requests = Vec::new();
2779                 let mut watch_outputs = Vec::new();
2780
2781                 macro_rules! append_onchain_update {
2782                         ($updates: expr, $to_watch: expr) => {
2783                                 claim_requests = $updates.0;
2784                                 self.broadcasted_holder_revokable_script = $updates.1;
2785                                 watch_outputs.append(&mut $to_watch);
2786                         }
2787                 }
2788
2789                 // HTLCs set may differ between last and previous holder commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
2790                 let mut is_holder_tx = false;
2791
2792                 if self.current_holder_commitment_tx.txid == commitment_txid {
2793                         is_holder_tx = true;
2794                         log_info!(logger, "Got broadcast of latest holder commitment tx {}, searching for available HTLCs to claim", commitment_txid);
2795                         let res = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, height);
2796                         let mut to_watch = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, tx);
2797                         append_onchain_update!(res, to_watch);
2798                         fail_unbroadcast_htlcs!(self, "latest holder", commitment_txid, tx, height,
2799                                 block_hash, self.current_holder_commitment_tx.htlc_outputs.iter()
2800                                 .map(|(htlc, _, htlc_source)| (htlc, htlc_source.as_ref())), logger);
2801                 } else if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
2802                         if holder_tx.txid == commitment_txid {
2803                                 is_holder_tx = true;
2804                                 log_info!(logger, "Got broadcast of previous holder commitment tx {}, searching for available HTLCs to claim", commitment_txid);
2805                                 let res = self.get_broadcasted_holder_claims(holder_tx, height);
2806                                 let mut to_watch = self.get_broadcasted_holder_watch_outputs(holder_tx, tx);
2807                                 append_onchain_update!(res, to_watch);
2808                                 fail_unbroadcast_htlcs!(self, "previous holder", commitment_txid, tx, height, block_hash,
2809                                         holder_tx.htlc_outputs.iter().map(|(htlc, _, htlc_source)| (htlc, htlc_source.as_ref())),
2810                                         logger);
2811                         }
2812                 }
2813
2814                 if is_holder_tx {
2815                         Some((claim_requests, (commitment_txid, watch_outputs)))
2816                 } else {
2817                         None
2818                 }
2819         }
2820
2821         pub fn get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
2822                 log_debug!(logger, "Getting signed latest holder commitment transaction!");
2823                 self.holder_tx_signed = true;
2824                 let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
2825                 let txid = commitment_tx.txid();
2826                 let mut holder_transactions = vec![commitment_tx];
2827                 // When anchor outputs are present, the HTLC transactions are only valid once the commitment
2828                 // transaction confirms.
2829                 if self.onchain_tx_handler.opt_anchors() {
2830                         return holder_transactions;
2831                 }
2832                 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
2833                         if let Some(vout) = htlc.0.transaction_output_index {
2834                                 let preimage = if !htlc.0.offered {
2835                                         if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
2836                                                 // We can't build an HTLC-Success transaction without the preimage
2837                                                 continue;
2838                                         }
2839                                 } else if htlc.0.cltv_expiry > self.best_block.height() + 1 {
2840                                         // Don't broadcast HTLC-Timeout transactions immediately as they don't meet the
2841                                         // current locktime requirements on-chain. We will broadcast them in
2842                                         // `block_confirmed` when `should_broadcast_holder_commitment_txn` returns true.
2843                                         // Note that we add + 1 as transactions are broadcastable when they can be
2844                                         // confirmed in the next block.
2845                                         continue;
2846                                 } else { None };
2847                                 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
2848                                         &::bitcoin::OutPoint { txid, vout }, &preimage) {
2849                                         holder_transactions.push(htlc_tx);
2850                                 }
2851                         }
2852                 }
2853                 // We throw away the generated waiting_first_conf data as we aren't (yet) confirmed and we don't actually know what the caller wants to do.
2854                 // The data will be re-generated and tracked in check_spend_holder_transaction if we get a confirmation.
2855                 holder_transactions
2856         }
2857
2858         #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
2859         /// Note that this includes possibly-locktimed-in-the-future transactions!
2860         fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
2861                 log_debug!(logger, "Getting signed copy of latest holder commitment transaction!");
2862                 let commitment_tx = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript);
2863                 let txid = commitment_tx.txid();
2864                 let mut holder_transactions = vec![commitment_tx];
2865                 // When anchor outputs are present, the HTLC transactions are only final once the commitment
2866                 // transaction confirms due to the CSV 1 encumberance.
2867                 if self.onchain_tx_handler.opt_anchors() {
2868                         return holder_transactions;
2869                 }
2870                 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
2871                         if let Some(vout) = htlc.0.transaction_output_index {
2872                                 let preimage = if !htlc.0.offered {
2873                                         if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
2874                                                 // We can't build an HTLC-Success transaction without the preimage
2875                                                 continue;
2876                                         }
2877                                 } else { None };
2878                                 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
2879                                         &::bitcoin::OutPoint { txid, vout }, &preimage) {
2880                                         holder_transactions.push(htlc_tx);
2881                                 }
2882                         }
2883                 }
2884                 holder_transactions
2885         }
2886
2887         pub fn block_connected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, txdata: &TransactionData, height: u32, broadcaster: B, fee_estimator: F, logger: L) -> Vec<TransactionOutputs>
2888                 where B::Target: BroadcasterInterface,
2889                       F::Target: FeeEstimator,
2890                                         L::Target: Logger,
2891         {
2892                 let block_hash = header.block_hash();
2893                 self.best_block = BestBlock::new(block_hash, height);
2894
2895                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
2896                 self.transactions_confirmed(header, txdata, height, broadcaster, &bounded_fee_estimator, logger)
2897         }
2898
2899         fn best_block_updated<B: Deref, F: Deref, L: Deref>(
2900                 &mut self,
2901                 header: &BlockHeader,
2902                 height: u32,
2903                 broadcaster: B,
2904                 fee_estimator: &LowerBoundedFeeEstimator<F>,
2905                 logger: L,
2906         ) -> Vec<TransactionOutputs>
2907         where
2908                 B::Target: BroadcasterInterface,
2909                 F::Target: FeeEstimator,
2910                 L::Target: Logger,
2911         {
2912                 let block_hash = header.block_hash();
2913
2914                 if height > self.best_block.height() {
2915                         self.best_block = BestBlock::new(block_hash, height);
2916                         self.block_confirmed(height, block_hash, vec![], vec![], vec![], &broadcaster, &fee_estimator, &logger)
2917                 } else if block_hash != self.best_block.block_hash() {
2918                         self.best_block = BestBlock::new(block_hash, height);
2919                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height <= height);
2920                         self.onchain_tx_handler.block_disconnected(height + 1, broadcaster, fee_estimator, logger);
2921                         Vec::new()
2922                 } else { Vec::new() }
2923         }
2924
2925         fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
2926                 &mut self,
2927                 header: &BlockHeader,
2928                 txdata: &TransactionData,
2929                 height: u32,
2930                 broadcaster: B,
2931                 fee_estimator: &LowerBoundedFeeEstimator<F>,
2932                 logger: L,
2933         ) -> Vec<TransactionOutputs>
2934         where
2935                 B::Target: BroadcasterInterface,
2936                 F::Target: FeeEstimator,
2937                 L::Target: Logger,
2938         {
2939                 let txn_matched = self.filter_block(txdata);
2940                 for tx in &txn_matched {
2941                         let mut output_val = 0;
2942                         for out in tx.output.iter() {
2943                                 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
2944                                 output_val += out.value;
2945                                 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
2946                         }
2947                 }
2948
2949                 let block_hash = header.block_hash();
2950
2951                 let mut watch_outputs = Vec::new();
2952                 let mut claimable_outpoints = Vec::new();
2953                 'tx_iter: for tx in &txn_matched {
2954                         let txid = tx.txid();
2955                         // If a transaction has already been confirmed, ensure we don't bother processing it duplicatively.
2956                         if Some(txid) == self.funding_spend_confirmed {
2957                                 log_debug!(logger, "Skipping redundant processing of funding-spend tx {} as it was previously confirmed", txid);
2958                                 continue 'tx_iter;
2959                         }
2960                         for ev in self.onchain_events_awaiting_threshold_conf.iter() {
2961                                 if ev.txid == txid {
2962                                         if let Some(conf_hash) = ev.block_hash {
2963                                                 assert_eq!(header.block_hash(), conf_hash,
2964                                                         "Transaction {} was already confirmed and is being re-confirmed in a different block.\n\
2965                                                         This indicates a severe bug in the transaction connection logic - a reorg should have been processed first!", ev.txid);
2966                                         }
2967                                         log_debug!(logger, "Skipping redundant processing of confirming tx {} as it was previously confirmed", txid);
2968                                         continue 'tx_iter;
2969                                 }
2970                         }
2971                         for htlc in self.htlcs_resolved_on_chain.iter() {
2972                                 if Some(txid) == htlc.resolving_txid {
2973                                         log_debug!(logger, "Skipping redundant processing of HTLC resolution tx {} as it was previously confirmed", txid);
2974                                         continue 'tx_iter;
2975                                 }
2976                         }
2977                         for spendable_txid in self.spendable_txids_confirmed.iter() {
2978                                 if txid == *spendable_txid {
2979                                         log_debug!(logger, "Skipping redundant processing of spendable tx {} as it was previously confirmed", txid);
2980                                         continue 'tx_iter;
2981                                 }
2982                         }
2983
2984                         if tx.input.len() == 1 {
2985                                 // Assuming our keys were not leaked (in which case we're screwed no matter what),
2986                                 // commitment transactions and HTLC transactions will all only ever have one input
2987                                 // (except for HTLC transactions for channels with anchor outputs), which is an easy
2988                                 // way to filter out any potential non-matching txn for lazy filters.
2989                                 let prevout = &tx.input[0].previous_output;
2990                                 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
2991                                         let mut balance_spendable_csv = None;
2992                                         log_info!(logger, "Channel {} closed by funding output spend in txid {}.",
2993                                                 log_bytes!(self.funding_info.0.to_channel_id()), txid);
2994                                         self.funding_spend_seen = true;
2995                                         let mut commitment_tx_to_counterparty_output = None;
2996                                         if (tx.input[0].sequence.0 >> 8*3) as u8 == 0x80 && (tx.lock_time.0 >> 8*3) as u8 == 0x20 {
2997                                                 let (mut new_outpoints, new_outputs, counterparty_output_idx_sats) =
2998                                                         self.check_spend_counterparty_transaction(&tx, height, &block_hash, &logger);
2999                                                 commitment_tx_to_counterparty_output = counterparty_output_idx_sats;
3000                                                 if !new_outputs.1.is_empty() {
3001                                                         watch_outputs.push(new_outputs);
3002                                                 }
3003                                                 claimable_outpoints.append(&mut new_outpoints);
3004                                                 if new_outpoints.is_empty() {
3005                                                         if let Some((mut new_outpoints, new_outputs)) = self.check_spend_holder_transaction(&tx, height, &block_hash, &logger) {
3006                                                                 debug_assert!(commitment_tx_to_counterparty_output.is_none(),
3007                                                                         "A commitment transaction matched as both a counterparty and local commitment tx?");
3008                                                                 if !new_outputs.1.is_empty() {
3009                                                                         watch_outputs.push(new_outputs);
3010                                                                 }
3011                                                                 claimable_outpoints.append(&mut new_outpoints);
3012                                                                 balance_spendable_csv = Some(self.on_holder_tx_csv);
3013                                                         }
3014                                                 }
3015                                         }
3016                                         self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3017                                                 txid,
3018                                                 transaction: Some((*tx).clone()),
3019                                                 height,
3020                                                 block_hash: Some(block_hash),
3021                                                 event: OnchainEvent::FundingSpendConfirmation {
3022                                                         on_local_output_csv: balance_spendable_csv,
3023                                                         commitment_tx_to_counterparty_output,
3024                                                 },
3025                                         });
3026                                 }
3027                         }
3028                         if tx.input.len() >= 1 {
3029                                 // While all commitment transactions have one input, HTLC transactions may have more
3030                                 // if the HTLC was present in an anchor channel. HTLCs can also be resolved in a few
3031                                 // other ways which can have more than one output.
3032                                 for tx_input in &tx.input {
3033                                         let commitment_txid = tx_input.previous_output.txid;
3034                                         if let Some(&commitment_number) = self.counterparty_commitment_txn_on_chain.get(&commitment_txid) {
3035                                                 let (mut new_outpoints, new_outputs_option) = self.check_spend_counterparty_htlc(
3036                                                         &tx, commitment_number, &commitment_txid, height, &logger
3037                                                 );
3038                                                 claimable_outpoints.append(&mut new_outpoints);
3039                                                 if let Some(new_outputs) = new_outputs_option {
3040                                                         watch_outputs.push(new_outputs);
3041                                                 }
3042                                                 // Since there may be multiple HTLCs for this channel (all spending the
3043                                                 // same commitment tx) being claimed by the counterparty within the same
3044                                                 // transaction, and `check_spend_counterparty_htlc` already checks all the
3045                                                 // ones relevant to this channel, we can safely break from our loop.
3046                                                 break;
3047                                         }
3048                                 }
3049                                 self.is_resolving_htlc_output(&tx, height, &block_hash, &logger);
3050
3051                                 self.is_paying_spendable_output(&tx, height, &block_hash, &logger);
3052                         }
3053                 }
3054
3055                 if height > self.best_block.height() {
3056                         self.best_block = BestBlock::new(block_hash, height);
3057                 }
3058
3059                 self.block_confirmed(height, block_hash, txn_matched, watch_outputs, claimable_outpoints, &broadcaster, &fee_estimator, &logger)
3060         }
3061
3062         /// Update state for new block(s)/transaction(s) confirmed. Note that the caller must update
3063         /// `self.best_block` before calling if a new best blockchain tip is available. More
3064         /// concretely, `self.best_block` must never be at a lower height than `conf_height`, avoiding
3065         /// complexity especially in
3066         /// `OnchainTx::update_claims_view_from_requests`/`OnchainTx::update_claims_view_from_matched_txn`.
3067         ///
3068         /// `conf_height` should be set to the height at which any new transaction(s)/block(s) were
3069         /// confirmed at, even if it is not the current best height.
3070         fn block_confirmed<B: Deref, F: Deref, L: Deref>(
3071                 &mut self,
3072                 conf_height: u32,
3073                 conf_hash: BlockHash,
3074                 txn_matched: Vec<&Transaction>,
3075                 mut watch_outputs: Vec<TransactionOutputs>,
3076                 mut claimable_outpoints: Vec<PackageTemplate>,
3077                 broadcaster: &B,
3078                 fee_estimator: &LowerBoundedFeeEstimator<F>,
3079                 logger: &L,
3080         ) -> Vec<TransactionOutputs>
3081         where
3082                 B::Target: BroadcasterInterface,
3083                 F::Target: FeeEstimator,
3084                 L::Target: Logger,
3085         {
3086                 log_trace!(logger, "Processing {} matched transactions for block at height {}.", txn_matched.len(), conf_height);
3087                 debug_assert!(self.best_block.height() >= conf_height);
3088
3089                 let should_broadcast = self.should_broadcast_holder_commitment_txn(logger);
3090                 if should_broadcast {
3091                         let funding_outp = HolderFundingOutput::build(self.funding_redeemscript.clone(), self.channel_value_satoshis, self.onchain_tx_handler.opt_anchors());
3092                         let commitment_package = PackageTemplate::build_package(self.funding_info.0.txid.clone(), self.funding_info.0.index as u32, PackageSolvingData::HolderFundingOutput(funding_outp), self.best_block.height(), false, self.best_block.height());
3093                         claimable_outpoints.push(commitment_package);
3094                         self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
3095                         let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
3096                         self.holder_tx_signed = true;
3097                         // We can't broadcast our HTLC transactions while the commitment transaction is
3098                         // unconfirmed. We'll delay doing so until we detect the confirmed commitment in
3099                         // `transactions_confirmed`.
3100                         if !self.onchain_tx_handler.opt_anchors() {
3101                                 // Because we're broadcasting a commitment transaction, we should construct the package
3102                                 // assuming it gets confirmed in the next block. Sadly, we have code which considers
3103                                 // "not yet confirmed" things as discardable, so we cannot do that here.
3104                                 let (mut new_outpoints, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
3105                                 let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &commitment_tx);
3106                                 if !new_outputs.is_empty() {
3107                                         watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
3108                                 }
3109                                 claimable_outpoints.append(&mut new_outpoints);
3110                         }
3111                 }
3112
3113                 // Find which on-chain events have reached their confirmation threshold.
3114                 let onchain_events_awaiting_threshold_conf =
3115                         self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
3116                 let mut onchain_events_reaching_threshold_conf = Vec::new();
3117                 for entry in onchain_events_awaiting_threshold_conf {
3118                         if entry.has_reached_confirmation_threshold(&self.best_block) {
3119                                 onchain_events_reaching_threshold_conf.push(entry);
3120                         } else {
3121                                 self.onchain_events_awaiting_threshold_conf.push(entry);
3122                         }
3123                 }
3124
3125                 // Used to check for duplicate HTLC resolutions.
3126                 #[cfg(debug_assertions)]
3127                 let unmatured_htlcs: Vec<_> = self.onchain_events_awaiting_threshold_conf
3128                         .iter()
3129                         .filter_map(|entry| match &entry.event {
3130                                 OnchainEvent::HTLCUpdate { source, .. } => Some(source),
3131                                 _ => None,
3132                         })
3133                         .collect();
3134                 #[cfg(debug_assertions)]
3135                 let mut matured_htlcs = Vec::new();
3136
3137                 // Produce actionable events from on-chain events having reached their threshold.
3138                 for entry in onchain_events_reaching_threshold_conf.drain(..) {
3139                         match entry.event {
3140                                 OnchainEvent::HTLCUpdate { ref source, payment_hash, htlc_value_satoshis, commitment_tx_output_idx } => {
3141                                         // Check for duplicate HTLC resolutions.
3142                                         #[cfg(debug_assertions)]
3143                                         {
3144                                                 debug_assert!(
3145                                                         unmatured_htlcs.iter().find(|&htlc| htlc == &source).is_none(),
3146                                                         "An unmature HTLC transaction conflicts with a maturing one; failed to \
3147                                                          call either transaction_unconfirmed for the conflicting transaction \
3148                                                          or block_disconnected for a block containing it.");
3149                                                 debug_assert!(
3150                                                         matured_htlcs.iter().find(|&htlc| htlc == source).is_none(),
3151                                                         "A matured HTLC transaction conflicts with a maturing one; failed to \
3152                                                          call either transaction_unconfirmed for the conflicting transaction \
3153                                                          or block_disconnected for a block containing it.");
3154                                                 matured_htlcs.push(source.clone());
3155                                         }
3156
3157                                         log_debug!(logger, "HTLC {} failure update in {} has got enough confirmations to be passed upstream",
3158                                                 log_bytes!(payment_hash.0), entry.txid);
3159                                         self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
3160                                                 payment_hash,
3161                                                 payment_preimage: None,
3162                                                 source: source.clone(),
3163                                                 htlc_value_satoshis,
3164                                         }));
3165                                         self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC {
3166                                                 commitment_tx_output_idx,
3167                                                 resolving_txid: Some(entry.txid),
3168                                                 resolving_tx: entry.transaction,
3169                                                 payment_preimage: None,
3170                                         });
3171                                 },
3172                                 OnchainEvent::MaturingOutput { descriptor } => {
3173                                         log_debug!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
3174                                         self.pending_events.push(Event::SpendableOutputs {
3175                                                 outputs: vec![descriptor]
3176                                         });
3177                                         self.spendable_txids_confirmed.push(entry.txid);
3178                                 },
3179                                 OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, preimage, .. } => {
3180                                         self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC {
3181                                                 commitment_tx_output_idx: Some(commitment_tx_output_idx),
3182                                                 resolving_txid: Some(entry.txid),
3183                                                 resolving_tx: entry.transaction,
3184                                                 payment_preimage: preimage,
3185                                         });
3186                                 },
3187                                 OnchainEvent::FundingSpendConfirmation { commitment_tx_to_counterparty_output, .. } => {
3188                                         self.funding_spend_confirmed = Some(entry.txid);
3189                                         self.confirmed_commitment_tx_counterparty_output = commitment_tx_to_counterparty_output;
3190                                 },
3191                         }
3192                 }
3193
3194                 self.onchain_tx_handler.update_claims_view_from_requests(claimable_outpoints, conf_height, self.best_block.height(), broadcaster, fee_estimator, logger);
3195                 self.onchain_tx_handler.update_claims_view_from_matched_txn(&txn_matched, conf_height, conf_hash, self.best_block.height(), broadcaster, fee_estimator, logger);
3196
3197                 // Determine new outputs to watch by comparing against previously known outputs to watch,
3198                 // updating the latter in the process.
3199                 watch_outputs.retain(|&(ref txid, ref txouts)| {
3200                         let idx_and_scripts = txouts.iter().map(|o| (o.0, o.1.script_pubkey.clone())).collect();
3201                         self.outputs_to_watch.insert(txid.clone(), idx_and_scripts).is_none()
3202                 });
3203                 #[cfg(test)]
3204                 {
3205                         // If we see a transaction for which we registered outputs previously,
3206                         // make sure the registered scriptpubkey at the expected index match
3207                         // the actual transaction output one. We failed this case before #653.
3208                         for tx in &txn_matched {
3209                                 if let Some(outputs) = self.get_outputs_to_watch().get(&tx.txid()) {
3210                                         for idx_and_script in outputs.iter() {
3211                                                 assert!((idx_and_script.0 as usize) < tx.output.len());
3212                                                 assert_eq!(tx.output[idx_and_script.0 as usize].script_pubkey, idx_and_script.1);
3213                                         }
3214                                 }
3215                         }
3216                 }
3217                 watch_outputs
3218         }
3219
3220         pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, height: u32, broadcaster: B, fee_estimator: F, logger: L)
3221                 where B::Target: BroadcasterInterface,
3222                       F::Target: FeeEstimator,
3223                       L::Target: Logger,
3224         {
3225                 log_trace!(logger, "Block {} at height {} disconnected", header.block_hash(), height);
3226
3227                 //We may discard:
3228                 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
3229                 //- maturing spendable output has transaction paying us has been disconnected
3230                 self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height < height);
3231
3232                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
3233                 self.onchain_tx_handler.block_disconnected(height, broadcaster, &bounded_fee_estimator, logger);
3234
3235                 self.best_block = BestBlock::new(header.prev_blockhash, height - 1);
3236         }
3237
3238         fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
3239                 &mut self,
3240                 txid: &Txid,
3241                 broadcaster: B,
3242                 fee_estimator: &LowerBoundedFeeEstimator<F>,
3243                 logger: L,
3244         ) where
3245                 B::Target: BroadcasterInterface,
3246                 F::Target: FeeEstimator,
3247                 L::Target: Logger,
3248         {
3249                 let mut removed_height = None;
3250                 for entry in self.onchain_events_awaiting_threshold_conf.iter() {
3251                         if entry.txid == *txid {
3252                                 removed_height = Some(entry.height);
3253                                 break;
3254                         }
3255                 }
3256
3257                 if let Some(removed_height) = removed_height {
3258                         log_info!(logger, "transaction_unconfirmed of txid {} implies height {} was reorg'd out", txid, removed_height);
3259                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| if entry.height >= removed_height {
3260                                 log_info!(logger, "Transaction {} reorg'd out", entry.txid);
3261                                 false
3262                         } else { true });
3263                 }
3264
3265                 debug_assert!(!self.onchain_events_awaiting_threshold_conf.iter().any(|ref entry| entry.txid == *txid));
3266
3267                 self.onchain_tx_handler.transaction_unconfirmed(txid, broadcaster, fee_estimator, logger);
3268         }
3269
3270         /// Filters a block's `txdata` for transactions spending watched outputs or for any child
3271         /// transactions thereof.
3272         fn filter_block<'a>(&self, txdata: &TransactionData<'a>) -> Vec<&'a Transaction> {
3273                 let mut matched_txn = HashSet::new();
3274                 txdata.iter().filter(|&&(_, tx)| {
3275                         let mut matches = self.spends_watched_output(tx);
3276                         for input in tx.input.iter() {
3277                                 if matches { break; }
3278                                 if matched_txn.contains(&input.previous_output.txid) {
3279                                         matches = true;
3280                                 }
3281                         }
3282                         if matches {
3283                                 matched_txn.insert(tx.txid());
3284                         }
3285                         matches
3286                 }).map(|(_, tx)| *tx).collect()
3287         }
3288
3289         /// Checks if a given transaction spends any watched outputs.
3290         fn spends_watched_output(&self, tx: &Transaction) -> bool {
3291                 for input in tx.input.iter() {
3292                         if let Some(outputs) = self.get_outputs_to_watch().get(&input.previous_output.txid) {
3293                                 for (idx, _script_pubkey) in outputs.iter() {
3294                                         if *idx == input.previous_output.vout {
3295                                                 #[cfg(test)]
3296                                                 {
3297                                                         // If the expected script is a known type, check that the witness
3298                                                         // appears to be spending the correct type (ie that the match would
3299                                                         // actually succeed in BIP 158/159-style filters).
3300                                                         if _script_pubkey.is_v0_p2wsh() {
3301                                                                 if input.witness.last().unwrap().to_vec() == deliberately_bogus_accepted_htlc_witness_program() {
3302                                                                         // In at least one test we use a deliberately bogus witness
3303                                                                         // script which hit an old panic. Thus, we check for that here
3304                                                                         // and avoid the assert if its the expected bogus script.
3305                                                                         return true;
3306                                                                 }
3307
3308                                                                 assert_eq!(&bitcoin::Address::p2wsh(&Script::from(input.witness.last().unwrap().to_vec()), bitcoin::Network::Bitcoin).script_pubkey(), _script_pubkey);
3309                                                         } else if _script_pubkey.is_v0_p2wpkh() {
3310                                                                 assert_eq!(&bitcoin::Address::p2wpkh(&bitcoin::PublicKey::from_slice(&input.witness.last().unwrap()).unwrap(), bitcoin::Network::Bitcoin).unwrap().script_pubkey(), _script_pubkey);
3311                                                         } else { panic!(); }
3312                                                 }
3313                                                 return true;
3314                                         }
3315                                 }
3316                         }
3317                 }
3318
3319                 false
3320         }
3321
3322         fn should_broadcast_holder_commitment_txn<L: Deref>(&self, logger: &L) -> bool where L::Target: Logger {
3323                 // There's no need to broadcast our commitment transaction if we've seen one confirmed (even
3324                 // with 1 confirmation) as it'll be rejected as duplicate/conflicting.
3325                 if self.funding_spend_confirmed.is_some() ||
3326                         self.onchain_events_awaiting_threshold_conf.iter().find(|event| match event.event {
3327                                 OnchainEvent::FundingSpendConfirmation { .. } => true,
3328                                 _ => false,
3329                         }).is_some()
3330                 {
3331                         return false;
3332                 }
3333                 // We need to consider all HTLCs which are:
3334                 //  * in any unrevoked counterparty commitment transaction, as they could broadcast said
3335                 //    transactions and we'd end up in a race, or
3336                 //  * are in our latest holder commitment transaction, as this is the thing we will
3337                 //    broadcast if we go on-chain.
3338                 // Note that we consider HTLCs which were below dust threshold here - while they don't
3339                 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
3340                 // to the source, and if we don't fail the channel we will have to ensure that the next
3341                 // updates that peer sends us are update_fails, failing the channel if not. It's probably
3342                 // easier to just fail the channel as this case should be rare enough anyway.
3343                 let height = self.best_block.height();
3344                 macro_rules! scan_commitment {
3345                         ($htlcs: expr, $holder_tx: expr) => {
3346                                 for ref htlc in $htlcs {
3347                                         // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
3348                                         // chain with enough room to claim the HTLC without our counterparty being able to
3349                                         // time out the HTLC first.
3350                                         // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
3351                                         // concern is being able to claim the corresponding inbound HTLC (on another
3352                                         // channel) before it expires. In fact, we don't even really care if our
3353                                         // counterparty here claims such an outbound HTLC after it expired as long as we
3354                                         // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
3355                                         // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
3356                                         // we give ourselves a few blocks of headroom after expiration before going
3357                                         // on-chain for an expired HTLC.
3358                                         // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
3359                                         // from us until we've reached the point where we go on-chain with the
3360                                         // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
3361                                         // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
3362                                         //  aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
3363                                         //      inbound_cltv == height + CLTV_CLAIM_BUFFER
3364                                         //      outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
3365                                         //      LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
3366                                         //      CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
3367                                         //      LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
3368                                         //  The final, above, condition is checked for statically in channelmanager
3369                                         //  with CHECK_CLTV_EXPIRY_SANITY_2.
3370                                         let htlc_outbound = $holder_tx == htlc.offered;
3371                                         if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
3372                                            (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
3373                                                 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
3374                                                 return true;
3375                                         }
3376                                 }
3377                         }
3378                 }
3379
3380                 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
3381
3382                 if let Some(ref txid) = self.current_counterparty_commitment_txid {
3383                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
3384                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
3385                         }
3386                 }
3387                 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
3388                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
3389                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
3390                         }
3391                 }
3392
3393                 false
3394         }
3395
3396         /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a holder
3397         /// or counterparty commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
3398         fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, block_hash: &BlockHash, logger: &L) where L::Target: Logger {
3399                 'outer_loop: for input in &tx.input {
3400                         let mut payment_data = None;
3401                         let htlc_claim = HTLCClaim::from_witness(&input.witness);
3402                         let revocation_sig_claim = htlc_claim == Some(HTLCClaim::Revocation);
3403                         let accepted_preimage_claim = htlc_claim == Some(HTLCClaim::AcceptedPreimage);
3404                         #[cfg(not(fuzzing))]
3405                         let accepted_timeout_claim = htlc_claim == Some(HTLCClaim::AcceptedTimeout);
3406                         let offered_preimage_claim = htlc_claim == Some(HTLCClaim::OfferedPreimage);
3407                         #[cfg(not(fuzzing))]
3408                         let offered_timeout_claim = htlc_claim == Some(HTLCClaim::OfferedTimeout);
3409
3410                         let mut payment_preimage = PaymentPreimage([0; 32]);
3411                         if offered_preimage_claim || accepted_preimage_claim {
3412                                 payment_preimage.0.copy_from_slice(input.witness.second_to_last().unwrap());
3413                         }
3414
3415                         macro_rules! log_claim {
3416                                 ($tx_info: expr, $holder_tx: expr, $htlc: expr, $source_avail: expr) => {
3417                                         let outbound_htlc = $holder_tx == $htlc.offered;
3418                                         // HTLCs must either be claimed by a matching script type or through the
3419                                         // revocation path:
3420                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
3421                                         debug_assert!(!$htlc.offered || offered_preimage_claim || offered_timeout_claim || revocation_sig_claim);
3422                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
3423                                         debug_assert!($htlc.offered || accepted_preimage_claim || accepted_timeout_claim || revocation_sig_claim);
3424                                         // Further, only exactly one of the possible spend paths should have been
3425                                         // matched by any HTLC spend:
3426                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
3427                                         debug_assert_eq!(accepted_preimage_claim as u8 + accepted_timeout_claim as u8 +
3428                                                          offered_preimage_claim as u8 + offered_timeout_claim as u8 +
3429                                                          revocation_sig_claim as u8, 1);
3430                                         if ($holder_tx && revocation_sig_claim) ||
3431                                                         (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
3432                                                 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
3433                                                         $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
3434                                                         if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
3435                                                         if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back. We can likely claim the HTLC output with a revocation claim" });
3436                                         } else {
3437                                                 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
3438                                                         $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
3439                                                         if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
3440                                                         if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
3441                                         }
3442                                 }
3443                         }
3444
3445                         macro_rules! check_htlc_valid_counterparty {
3446                                 ($counterparty_txid: expr, $htlc_output: expr) => {
3447                                         if let Some(txid) = $counterparty_txid {
3448                                                 for &(ref pending_htlc, ref pending_source) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
3449                                                         if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
3450                                                                 if let &Some(ref source) = pending_source {
3451                                                                         log_claim!("revoked counterparty commitment tx", false, pending_htlc, true);
3452                                                                         payment_data = Some(((**source).clone(), $htlc_output.payment_hash, $htlc_output.amount_msat));
3453                                                                         break;
3454                                                                 }
3455                                                         }
3456                                                 }
3457                                         }
3458                                 }
3459                         }
3460
3461                         macro_rules! scan_commitment {
3462                                 ($htlcs: expr, $tx_info: expr, $holder_tx: expr) => {
3463                                         for (ref htlc_output, source_option) in $htlcs {
3464                                                 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
3465                                                         if let Some(ref source) = source_option {
3466                                                                 log_claim!($tx_info, $holder_tx, htlc_output, true);
3467                                                                 // We have a resolution of an HTLC either from one of our latest
3468                                                                 // holder commitment transactions or an unrevoked counterparty commitment
3469                                                                 // transaction. This implies we either learned a preimage, the HTLC
3470                                                                 // has timed out, or we screwed up. In any case, we should now
3471                                                                 // resolve the source HTLC with the original sender.
3472                                                                 payment_data = Some(((*source).clone(), htlc_output.payment_hash, htlc_output.amount_msat));
3473                                                         } else if !$holder_tx {
3474                                                                 check_htlc_valid_counterparty!(self.current_counterparty_commitment_txid, htlc_output);
3475                                                                 if payment_data.is_none() {
3476                                                                         check_htlc_valid_counterparty!(self.prev_counterparty_commitment_txid, htlc_output);
3477                                                                 }
3478                                                         }
3479                                                         if payment_data.is_none() {
3480                                                                 log_claim!($tx_info, $holder_tx, htlc_output, false);
3481                                                                 let outbound_htlc = $holder_tx == htlc_output.offered;
3482                                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3483                                                                         txid: tx.txid(), height, block_hash: Some(*block_hash), transaction: Some(tx.clone()),
3484                                                                         event: OnchainEvent::HTLCSpendConfirmation {
3485                                                                                 commitment_tx_output_idx: input.previous_output.vout,
3486                                                                                 preimage: if accepted_preimage_claim || offered_preimage_claim {
3487                                                                                         Some(payment_preimage) } else { None },
3488                                                                                 // If this is a payment to us (ie !outbound_htlc), wait for
3489                                                                                 // the CSV delay before dropping the HTLC from claimable
3490                                                                                 // balance if the claim was an HTLC-Success transaction (ie
3491                                                                                 // accepted_preimage_claim).
3492                                                                                 on_to_local_output_csv: if accepted_preimage_claim && !outbound_htlc {
3493                                                                                         Some(self.on_holder_tx_csv) } else { None },
3494                                                                         },
3495                                                                 });
3496                                                                 continue 'outer_loop;
3497                                                         }
3498                                                 }
3499                                         }
3500                                 }
3501                         }
3502
3503                         if input.previous_output.txid == self.current_holder_commitment_tx.txid {
3504                                 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
3505                                         "our latest holder commitment tx", true);
3506                         }
3507                         if let Some(ref prev_holder_signed_commitment_tx) = self.prev_holder_signed_commitment_tx {
3508                                 if input.previous_output.txid == prev_holder_signed_commitment_tx.txid {
3509                                         scan_commitment!(prev_holder_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
3510                                                 "our previous holder commitment tx", true);
3511                                 }
3512                         }
3513                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(&input.previous_output.txid) {
3514                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
3515                                         "counterparty commitment tx", false);
3516                         }
3517
3518                         // Check that scan_commitment, above, decided there is some source worth relaying an
3519                         // HTLC resolution backwards to and figure out whether we learned a preimage from it.
3520                         if let Some((source, payment_hash, amount_msat)) = payment_data {
3521                                 if accepted_preimage_claim {
3522                                         if !self.pending_monitor_events.iter().any(
3523                                                 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update { upd.source == source } else { false }) {
3524                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3525                                                         txid: tx.txid(),
3526                                                         height,
3527                                                         block_hash: Some(*block_hash),
3528                                                         transaction: Some(tx.clone()),
3529                                                         event: OnchainEvent::HTLCSpendConfirmation {
3530                                                                 commitment_tx_output_idx: input.previous_output.vout,
3531                                                                 preimage: Some(payment_preimage),
3532                                                                 on_to_local_output_csv: None,
3533                                                         },
3534                                                 });
3535                                                 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
3536                                                         source,
3537                                                         payment_preimage: Some(payment_preimage),
3538                                                         payment_hash,
3539                                                         htlc_value_satoshis: Some(amount_msat / 1000),
3540                                                 }));
3541                                         }
3542                                 } else if offered_preimage_claim {
3543                                         if !self.pending_monitor_events.iter().any(
3544                                                 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update {
3545                                                         upd.source == source
3546                                                 } else { false }) {
3547                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3548                                                         txid: tx.txid(),
3549                                                         transaction: Some(tx.clone()),
3550                                                         height,
3551                                                         block_hash: Some(*block_hash),
3552                                                         event: OnchainEvent::HTLCSpendConfirmation {
3553                                                                 commitment_tx_output_idx: input.previous_output.vout,
3554                                                                 preimage: Some(payment_preimage),
3555                                                                 on_to_local_output_csv: None,
3556                                                         },
3557                                                 });
3558                                                 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
3559                                                         source,
3560                                                         payment_preimage: Some(payment_preimage),
3561                                                         payment_hash,
3562                                                         htlc_value_satoshis: Some(amount_msat / 1000),
3563                                                 }));
3564                                         }
3565                                 } else {
3566                                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
3567                                                 if entry.height != height { return true; }
3568                                                 match entry.event {
3569                                                         OnchainEvent::HTLCUpdate { source: ref htlc_source, .. } => {
3570                                                                 *htlc_source != source
3571                                                         },
3572                                                         _ => true,
3573                                                 }
3574                                         });
3575                                         let entry = OnchainEventEntry {
3576                                                 txid: tx.txid(),
3577                                                 transaction: Some(tx.clone()),
3578                                                 height,
3579                                                 block_hash: Some(*block_hash),
3580                                                 event: OnchainEvent::HTLCUpdate {
3581                                                         source, payment_hash,
3582                                                         htlc_value_satoshis: Some(amount_msat / 1000),
3583                                                         commitment_tx_output_idx: Some(input.previous_output.vout),
3584                                                 },
3585                                         };
3586                                         log_info!(logger, "Failing HTLC with payment_hash {} timeout by a spend tx, waiting for confirmation (at height {})", log_bytes!(payment_hash.0), entry.confirmation_threshold());
3587                                         self.onchain_events_awaiting_threshold_conf.push(entry);
3588                                 }
3589                         }
3590                 }
3591         }
3592
3593         /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
3594         fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, block_hash: &BlockHash, logger: &L) where L::Target: Logger {
3595                 let mut spendable_output = None;
3596                 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
3597                         if i > ::core::u16::MAX as usize {
3598                                 // While it is possible that an output exists on chain which is greater than the
3599                                 // 2^16th output in a given transaction, this is only possible if the output is not
3600                                 // in a lightning transaction and was instead placed there by some third party who
3601                                 // wishes to give us money for no reason.
3602                                 // Namely, any lightning transactions which we pre-sign will never have anywhere
3603                                 // near 2^16 outputs both because such transactions must have ~2^16 outputs who's
3604                                 // scripts are not longer than one byte in length and because they are inherently
3605                                 // non-standard due to their size.
3606                                 // Thus, it is completely safe to ignore such outputs, and while it may result in
3607                                 // us ignoring non-lightning fund to us, that is only possible if someone fills
3608                                 // nearly a full block with garbage just to hit this case.
3609                                 continue;
3610                         }
3611                         if outp.script_pubkey == self.destination_script {
3612                                 spendable_output =  Some(SpendableOutputDescriptor::StaticOutput {
3613                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3614                                         output: outp.clone(),
3615                                 });
3616                                 break;
3617                         }
3618                         if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
3619                                 if broadcasted_holder_revokable_script.0 == outp.script_pubkey {
3620                                         spendable_output =  Some(SpendableOutputDescriptor::DelayedPaymentOutput(DelayedPaymentOutputDescriptor {
3621                                                 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3622                                                 per_commitment_point: broadcasted_holder_revokable_script.1,
3623                                                 to_self_delay: self.on_holder_tx_csv,
3624                                                 output: outp.clone(),
3625                                                 revocation_pubkey: broadcasted_holder_revokable_script.2.clone(),
3626                                                 channel_keys_id: self.channel_keys_id,
3627                                                 channel_value_satoshis: self.channel_value_satoshis,
3628                                         }));
3629                                         break;
3630                                 }
3631                         }
3632                         if self.counterparty_payment_script == outp.script_pubkey {
3633                                 spendable_output = Some(SpendableOutputDescriptor::StaticPaymentOutput(StaticPaymentOutputDescriptor {
3634                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3635                                         output: outp.clone(),
3636                                         channel_keys_id: self.channel_keys_id,
3637                                         channel_value_satoshis: self.channel_value_satoshis,
3638                                 }));
3639                                 break;
3640                         }
3641                         if self.shutdown_script.as_ref() == Some(&outp.script_pubkey) {
3642                                 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
3643                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3644                                         output: outp.clone(),
3645                                 });
3646                                 break;
3647                         }
3648                 }
3649                 if let Some(spendable_output) = spendable_output {
3650                         let entry = OnchainEventEntry {
3651                                 txid: tx.txid(),
3652                                 transaction: Some(tx.clone()),
3653                                 height,
3654                                 block_hash: Some(*block_hash),
3655                                 event: OnchainEvent::MaturingOutput { descriptor: spendable_output.clone() },
3656                         };
3657                         log_info!(logger, "Received spendable output {}, spendable at height {}", log_spendable!(spendable_output), entry.confirmation_threshold());
3658                         self.onchain_events_awaiting_threshold_conf.push(entry);
3659                 }
3660         }
3661 }
3662
3663 impl<Signer: WriteableEcdsaChannelSigner, T: Deref, F: Deref, L: Deref> chain::Listen for (ChannelMonitor<Signer>, T, F, L)
3664 where
3665         T::Target: BroadcasterInterface,
3666         F::Target: FeeEstimator,
3667         L::Target: Logger,
3668 {
3669         fn filtered_block_connected(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
3670                 self.0.block_connected(header, txdata, height, &*self.1, &*self.2, &*self.3);
3671         }
3672
3673         fn block_disconnected(&self, header: &BlockHeader, height: u32) {
3674                 self.0.block_disconnected(header, height, &*self.1, &*self.2, &*self.3);
3675         }
3676 }
3677
3678 impl<Signer: WriteableEcdsaChannelSigner, T: Deref, F: Deref, L: Deref> chain::Confirm for (ChannelMonitor<Signer>, T, F, L)
3679 where
3680         T::Target: BroadcasterInterface,
3681         F::Target: FeeEstimator,
3682         L::Target: Logger,
3683 {
3684         fn transactions_confirmed(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
3685                 self.0.transactions_confirmed(header, txdata, height, &*self.1, &*self.2, &*self.3);
3686         }
3687
3688         fn transaction_unconfirmed(&self, txid: &Txid) {
3689                 self.0.transaction_unconfirmed(txid, &*self.1, &*self.2, &*self.3);
3690         }
3691
3692         fn best_block_updated(&self, header: &BlockHeader, height: u32) {
3693                 self.0.best_block_updated(header, height, &*self.1, &*self.2, &*self.3);
3694         }
3695
3696         fn get_relevant_txids(&self) -> Vec<(Txid, Option<BlockHash>)> {
3697                 self.0.get_relevant_txids()
3698         }
3699 }
3700
3701 const MAX_ALLOC_SIZE: usize = 64*1024;
3702
3703 impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP)>
3704                 for (BlockHash, ChannelMonitor<SP::Signer>) {
3705         fn read<R: io::Read>(reader: &mut R, args: (&'a ES, &'b SP)) -> Result<Self, DecodeError> {
3706                 macro_rules! unwrap_obj {
3707                         ($key: expr) => {
3708                                 match $key {
3709                                         Ok(res) => res,
3710                                         Err(_) => return Err(DecodeError::InvalidValue),
3711                                 }
3712                         }
3713                 }
3714
3715                 let (entropy_source, signer_provider) = args;
3716
3717                 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
3718
3719                 let latest_update_id: u64 = Readable::read(reader)?;
3720                 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
3721
3722                 let destination_script = Readable::read(reader)?;
3723                 let broadcasted_holder_revokable_script = match <u8 as Readable>::read(reader)? {
3724                         0 => {
3725                                 let revokable_address = Readable::read(reader)?;
3726                                 let per_commitment_point = Readable::read(reader)?;
3727                                 let revokable_script = Readable::read(reader)?;
3728                                 Some((revokable_address, per_commitment_point, revokable_script))
3729                         },
3730                         1 => { None },
3731                         _ => return Err(DecodeError::InvalidValue),
3732                 };
3733                 let counterparty_payment_script = Readable::read(reader)?;
3734                 let shutdown_script = {
3735                         let script = <Script as Readable>::read(reader)?;
3736                         if script.is_empty() { None } else { Some(script) }
3737                 };
3738
3739                 let channel_keys_id = Readable::read(reader)?;
3740                 let holder_revocation_basepoint = Readable::read(reader)?;
3741                 // Technically this can fail and serialize fail a round-trip, but only for serialization of
3742                 // barely-init'd ChannelMonitors that we can't do anything with.
3743                 let outpoint = OutPoint {
3744                         txid: Readable::read(reader)?,
3745                         index: Readable::read(reader)?,
3746                 };
3747                 let funding_info = (outpoint, Readable::read(reader)?);
3748                 let current_counterparty_commitment_txid = Readable::read(reader)?;
3749                 let prev_counterparty_commitment_txid = Readable::read(reader)?;
3750
3751                 let counterparty_commitment_params = Readable::read(reader)?;
3752                 let funding_redeemscript = Readable::read(reader)?;
3753                 let channel_value_satoshis = Readable::read(reader)?;
3754
3755                 let their_cur_per_commitment_points = {
3756                         let first_idx = <U48 as Readable>::read(reader)?.0;
3757                         if first_idx == 0 {
3758                                 None
3759                         } else {
3760                                 let first_point = Readable::read(reader)?;
3761                                 let second_point_slice: [u8; 33] = Readable::read(reader)?;
3762                                 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
3763                                         Some((first_idx, first_point, None))
3764                                 } else {
3765                                         Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
3766                                 }
3767                         }
3768                 };
3769
3770                 let on_holder_tx_csv: u16 = Readable::read(reader)?;
3771
3772                 let commitment_secrets = Readable::read(reader)?;
3773
3774                 macro_rules! read_htlc_in_commitment {
3775                         () => {
3776                                 {
3777                                         let offered: bool = Readable::read(reader)?;
3778                                         let amount_msat: u64 = Readable::read(reader)?;
3779                                         let cltv_expiry: u32 = Readable::read(reader)?;
3780                                         let payment_hash: PaymentHash = Readable::read(reader)?;
3781                                         let transaction_output_index: Option<u32> = Readable::read(reader)?;
3782
3783                                         HTLCOutputInCommitment {
3784                                                 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
3785                                         }
3786                                 }
3787                         }
3788                 }
3789
3790                 let counterparty_claimable_outpoints_len: u64 = Readable::read(reader)?;
3791                 let mut counterparty_claimable_outpoints = HashMap::with_capacity(cmp::min(counterparty_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
3792                 for _ in 0..counterparty_claimable_outpoints_len {
3793                         let txid: Txid = Readable::read(reader)?;
3794                         let htlcs_count: u64 = Readable::read(reader)?;
3795                         let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
3796                         for _ in 0..htlcs_count {
3797                                 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
3798                         }
3799                         if let Some(_) = counterparty_claimable_outpoints.insert(txid, htlcs) {
3800                                 return Err(DecodeError::InvalidValue);
3801                         }
3802                 }
3803
3804                 let counterparty_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
3805                 let mut counterparty_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(counterparty_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
3806                 for _ in 0..counterparty_commitment_txn_on_chain_len {
3807                         let txid: Txid = Readable::read(reader)?;
3808                         let commitment_number = <U48 as Readable>::read(reader)?.0;
3809                         if let Some(_) = counterparty_commitment_txn_on_chain.insert(txid, commitment_number) {
3810                                 return Err(DecodeError::InvalidValue);
3811                         }
3812                 }
3813
3814                 let counterparty_hash_commitment_number_len: u64 = Readable::read(reader)?;
3815                 let mut counterparty_hash_commitment_number = HashMap::with_capacity(cmp::min(counterparty_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
3816                 for _ in 0..counterparty_hash_commitment_number_len {
3817                         let payment_hash: PaymentHash = Readable::read(reader)?;
3818                         let commitment_number = <U48 as Readable>::read(reader)?.0;
3819                         if let Some(_) = counterparty_hash_commitment_number.insert(payment_hash, commitment_number) {
3820                                 return Err(DecodeError::InvalidValue);
3821                         }
3822                 }
3823
3824                 let mut prev_holder_signed_commitment_tx: Option<HolderSignedTx> =
3825                         match <u8 as Readable>::read(reader)? {
3826                                 0 => None,
3827                                 1 => {
3828                                         Some(Readable::read(reader)?)
3829                                 },
3830                                 _ => return Err(DecodeError::InvalidValue),
3831                         };
3832                 let mut current_holder_commitment_tx: HolderSignedTx = Readable::read(reader)?;
3833
3834                 let current_counterparty_commitment_number = <U48 as Readable>::read(reader)?.0;
3835                 let current_holder_commitment_number = <U48 as Readable>::read(reader)?.0;
3836
3837                 let payment_preimages_len: u64 = Readable::read(reader)?;
3838                 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
3839                 for _ in 0..payment_preimages_len {
3840                         let preimage: PaymentPreimage = Readable::read(reader)?;
3841                         let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
3842                         if let Some(_) = payment_preimages.insert(hash, preimage) {
3843                                 return Err(DecodeError::InvalidValue);
3844                         }
3845                 }
3846
3847                 let pending_monitor_events_len: u64 = Readable::read(reader)?;
3848                 let mut pending_monitor_events = Some(
3849                         Vec::with_capacity(cmp::min(pending_monitor_events_len as usize, MAX_ALLOC_SIZE / (32 + 8*3))));
3850                 for _ in 0..pending_monitor_events_len {
3851                         let ev = match <u8 as Readable>::read(reader)? {
3852                                 0 => MonitorEvent::HTLCEvent(Readable::read(reader)?),
3853                                 1 => MonitorEvent::CommitmentTxConfirmed(funding_info.0),
3854                                 _ => return Err(DecodeError::InvalidValue)
3855                         };
3856                         pending_monitor_events.as_mut().unwrap().push(ev);
3857                 }
3858
3859                 let pending_events_len: u64 = Readable::read(reader)?;
3860                 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Event>()));
3861                 for _ in 0..pending_events_len {
3862                         if let Some(event) = MaybeReadable::read(reader)? {
3863                                 pending_events.push(event);
3864                         }
3865                 }
3866
3867                 let best_block = BestBlock::new(Readable::read(reader)?, Readable::read(reader)?);
3868
3869                 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
3870                 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
3871                 for _ in 0..waiting_threshold_conf_len {
3872                         if let Some(val) = MaybeReadable::read(reader)? {
3873                                 onchain_events_awaiting_threshold_conf.push(val);
3874                         }
3875                 }
3876
3877                 let outputs_to_watch_len: u64 = Readable::read(reader)?;
3878                 let mut outputs_to_watch = HashMap::with_capacity(cmp::min(outputs_to_watch_len as usize, MAX_ALLOC_SIZE / (mem::size_of::<Txid>() + mem::size_of::<u32>() + mem::size_of::<Vec<Script>>())));
3879                 for _ in 0..outputs_to_watch_len {
3880                         let txid = Readable::read(reader)?;
3881                         let outputs_len: u64 = Readable::read(reader)?;
3882                         let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / (mem::size_of::<u32>() + mem::size_of::<Script>())));
3883                         for _ in 0..outputs_len {
3884                                 outputs.push((Readable::read(reader)?, Readable::read(reader)?));
3885                         }
3886                         if let Some(_) = outputs_to_watch.insert(txid, outputs) {
3887                                 return Err(DecodeError::InvalidValue);
3888                         }
3889                 }
3890                 let onchain_tx_handler: OnchainTxHandler<SP::Signer> = ReadableArgs::read(
3891                         reader, (entropy_source, signer_provider, channel_value_satoshis, channel_keys_id)
3892                 )?;
3893
3894                 let lockdown_from_offchain = Readable::read(reader)?;
3895                 let holder_tx_signed = Readable::read(reader)?;
3896
3897                 if let Some(prev_commitment_tx) = prev_holder_signed_commitment_tx.as_mut() {
3898                         let prev_holder_value = onchain_tx_handler.get_prev_holder_commitment_to_self_value();
3899                         if prev_holder_value.is_none() { return Err(DecodeError::InvalidValue); }
3900                         if prev_commitment_tx.to_self_value_sat == u64::max_value() {
3901                                 prev_commitment_tx.to_self_value_sat = prev_holder_value.unwrap();
3902                         } else if prev_commitment_tx.to_self_value_sat != prev_holder_value.unwrap() {
3903                                 return Err(DecodeError::InvalidValue);
3904                         }
3905                 }
3906
3907                 let cur_holder_value = onchain_tx_handler.get_cur_holder_commitment_to_self_value();
3908                 if current_holder_commitment_tx.to_self_value_sat == u64::max_value() {
3909                         current_holder_commitment_tx.to_self_value_sat = cur_holder_value;
3910                 } else if current_holder_commitment_tx.to_self_value_sat != cur_holder_value {
3911                         return Err(DecodeError::InvalidValue);
3912                 }
3913
3914                 let mut funding_spend_confirmed = None;
3915                 let mut htlcs_resolved_on_chain = Some(Vec::new());
3916                 let mut funding_spend_seen = Some(false);
3917                 let mut counterparty_node_id = None;
3918                 let mut confirmed_commitment_tx_counterparty_output = None;
3919                 let mut spendable_txids_confirmed = Some(Vec::new());
3920                 let mut counterparty_fulfilled_htlcs = Some(HashMap::new());
3921                 read_tlv_fields!(reader, {
3922                         (1, funding_spend_confirmed, option),
3923                         (3, htlcs_resolved_on_chain, vec_type),
3924                         (5, pending_monitor_events, vec_type),
3925                         (7, funding_spend_seen, option),
3926                         (9, counterparty_node_id, option),
3927                         (11, confirmed_commitment_tx_counterparty_output, option),
3928                         (13, spendable_txids_confirmed, vec_type),
3929                         (15, counterparty_fulfilled_htlcs, option),
3930                 });
3931
3932                 Ok((best_block.block_hash(), ChannelMonitor::from_impl(ChannelMonitorImpl {
3933                         latest_update_id,
3934                         commitment_transaction_number_obscure_factor,
3935
3936                         destination_script,
3937                         broadcasted_holder_revokable_script,
3938                         counterparty_payment_script,
3939                         shutdown_script,
3940
3941                         channel_keys_id,
3942                         holder_revocation_basepoint,
3943                         funding_info,
3944                         current_counterparty_commitment_txid,
3945                         prev_counterparty_commitment_txid,
3946
3947                         counterparty_commitment_params,
3948                         funding_redeemscript,
3949                         channel_value_satoshis,
3950                         their_cur_per_commitment_points,
3951
3952                         on_holder_tx_csv,
3953
3954                         commitment_secrets,
3955                         counterparty_claimable_outpoints,
3956                         counterparty_commitment_txn_on_chain,
3957                         counterparty_hash_commitment_number,
3958                         counterparty_fulfilled_htlcs: counterparty_fulfilled_htlcs.unwrap(),
3959
3960                         prev_holder_signed_commitment_tx,
3961                         current_holder_commitment_tx,
3962                         current_counterparty_commitment_number,
3963                         current_holder_commitment_number,
3964
3965                         payment_preimages,
3966                         pending_monitor_events: pending_monitor_events.unwrap(),
3967                         pending_events,
3968
3969                         onchain_events_awaiting_threshold_conf,
3970                         outputs_to_watch,
3971
3972                         onchain_tx_handler,
3973
3974                         lockdown_from_offchain,
3975                         holder_tx_signed,
3976                         funding_spend_seen: funding_spend_seen.unwrap(),
3977                         funding_spend_confirmed,
3978                         confirmed_commitment_tx_counterparty_output,
3979                         htlcs_resolved_on_chain: htlcs_resolved_on_chain.unwrap(),
3980                         spendable_txids_confirmed: spendable_txids_confirmed.unwrap(),
3981
3982                         best_block,
3983                         counterparty_node_id,
3984                 })))
3985         }
3986 }
3987
3988 #[cfg(test)]
3989 mod tests {
3990         use bitcoin::blockdata::block::BlockHeader;
3991         use bitcoin::blockdata::script::{Script, Builder};
3992         use bitcoin::blockdata::opcodes;
3993         use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, EcdsaSighashType};
3994         use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
3995         use bitcoin::util::sighash;
3996         use bitcoin::hashes::Hash;
3997         use bitcoin::hashes::sha256::Hash as Sha256;
3998         use bitcoin::hashes::hex::FromHex;
3999         use bitcoin::hash_types::{BlockHash, Txid};
4000         use bitcoin::network::constants::Network;
4001         use bitcoin::secp256k1::{SecretKey,PublicKey};
4002         use bitcoin::secp256k1::Secp256k1;
4003
4004         use hex;
4005
4006         use crate::chain::chaininterface::LowerBoundedFeeEstimator;
4007
4008         use super::ChannelMonitorUpdateStep;
4009         use crate::{check_added_monitors, check_closed_broadcast, check_closed_event, check_spends, get_local_commitment_txn, get_monitor, get_route_and_payment_hash, unwrap_send_err};
4010         use crate::chain::{BestBlock, Confirm};
4011         use crate::chain::channelmonitor::ChannelMonitor;
4012         use crate::chain::package::{weight_offered_htlc, weight_received_htlc, weight_revoked_offered_htlc, weight_revoked_received_htlc, WEIGHT_REVOKED_OUTPUT};
4013         use crate::chain::transaction::OutPoint;
4014         use crate::chain::keysinterface::InMemorySigner;
4015         use crate::ln::{PaymentPreimage, PaymentHash};
4016         use crate::ln::chan_utils;
4017         use crate::ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
4018         use crate::ln::channelmanager::{PaymentSendFailure, PaymentId};
4019         use crate::ln::functional_test_utils::*;
4020         use crate::ln::script::ShutdownScript;
4021         use crate::util::errors::APIError;
4022         use crate::util::events::ClosureReason;
4023         use crate::util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};
4024         use crate::util::ser::{ReadableArgs, Writeable};
4025         use crate::sync::{Arc, Mutex};
4026         use crate::io;
4027         use bitcoin::{PackedLockTime, Sequence, TxMerkleNode, Witness};
4028         use crate::prelude::*;
4029
4030         fn do_test_funding_spend_refuses_updates(use_local_txn: bool) {
4031                 // Previously, monitor updates were allowed freely even after a funding-spend transaction
4032                 // confirmed. This would allow a race condition where we could receive a payment (including
4033                 // the counterparty revoking their broadcasted state!) and accept it without recourse as
4034                 // long as the ChannelMonitor receives the block first, the full commitment update dance
4035                 // occurs after the block is connected, and before the ChannelManager receives the block.
4036                 // Obviously this is an incredibly contrived race given the counterparty would be risking
4037                 // their full channel balance for it, but its worth fixing nonetheless as it makes the
4038                 // potential ChannelMonitor states simpler to reason about.
4039                 //
4040                 // This test checks said behavior, as well as ensuring a ChannelMonitorUpdate with multiple
4041                 // updates is handled correctly in such conditions.
4042                 let chanmon_cfgs = create_chanmon_cfgs(3);
4043                 let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
4044                 let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
4045                 let nodes = create_network(3, &node_cfgs, &node_chanmgrs);
4046                 let channel = create_announced_chan_between_nodes(&nodes, 0, 1);
4047                 create_announced_chan_between_nodes(&nodes, 1, 2);
4048
4049                 // Rebalance somewhat
4050                 send_payment(&nodes[0], &[&nodes[1]], 10_000_000);
4051
4052                 // First route two payments for testing at the end
4053                 let payment_preimage_1 = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 1_000_000).0;
4054                 let payment_preimage_2 = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 1_000_000).0;
4055
4056                 let local_txn = get_local_commitment_txn!(nodes[1], channel.2);
4057                 assert_eq!(local_txn.len(), 1);
4058                 let remote_txn = get_local_commitment_txn!(nodes[0], channel.2);
4059                 assert_eq!(remote_txn.len(), 3); // Commitment and two HTLC-Timeouts
4060                 check_spends!(remote_txn[1], remote_txn[0]);
4061                 check_spends!(remote_txn[2], remote_txn[0]);
4062                 let broadcast_tx = if use_local_txn { &local_txn[0] } else { &remote_txn[0] };
4063
4064                 // Connect a commitment transaction, but only to the ChainMonitor/ChannelMonitor. The
4065                 // channel is now closed, but the ChannelManager doesn't know that yet.
4066                 let new_header = BlockHeader {
4067                         version: 2, time: 0, bits: 0, nonce: 0,
4068                         prev_blockhash: nodes[0].best_block_info().0,
4069                         merkle_root: TxMerkleNode::all_zeros() };
4070                 let conf_height = nodes[0].best_block_info().1 + 1;
4071                 nodes[1].chain_monitor.chain_monitor.transactions_confirmed(&new_header,
4072                         &[(0, broadcast_tx)], conf_height);
4073
4074                 let (_, pre_update_monitor) = <(BlockHash, ChannelMonitor<InMemorySigner>)>::read(
4075                                                 &mut io::Cursor::new(&get_monitor!(nodes[1], channel.2).encode()),
4076                                                 (&nodes[1].keys_manager.backing, &nodes[1].keys_manager.backing)).unwrap();
4077
4078                 // If the ChannelManager tries to update the channel, however, the ChainMonitor will pass
4079                 // the update through to the ChannelMonitor which will refuse it (as the channel is closed).
4080                 let (route, payment_hash, _, payment_secret) = get_route_and_payment_hash!(nodes[1], nodes[0], 100_000);
4081                 unwrap_send_err!(nodes[1].node.send_payment(&route, payment_hash, &Some(payment_secret), PaymentId(payment_hash.0)),
4082                         true, APIError::ChannelUnavailable { ref err },
4083                         assert!(err.contains("ChannelMonitor storage failure")));
4084                 check_added_monitors!(nodes[1], 2); // After the failure we generate a close-channel monitor update
4085                 check_closed_broadcast!(nodes[1], true);
4086                 check_closed_event!(nodes[1], 1, ClosureReason::ProcessingError { err: "ChannelMonitor storage failure".to_string() });
4087
4088                 // Build a new ChannelMonitorUpdate which contains both the failing commitment tx update
4089                 // and provides the claim preimages for the two pending HTLCs. The first update generates
4090                 // an error, but the point of this test is to ensure the later updates are still applied.
4091                 let monitor_updates = nodes[1].chain_monitor.monitor_updates.lock().unwrap();
4092                 let mut replay_update = monitor_updates.get(&channel.2).unwrap().iter().rev().skip(1).next().unwrap().clone();
4093                 assert_eq!(replay_update.updates.len(), 1);
4094                 if let ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { .. } = replay_update.updates[0] {
4095                 } else { panic!(); }
4096                 replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_1 });
4097                 replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_2 });
4098
4099                 let broadcaster = TestBroadcaster::new(Arc::clone(&nodes[1].blocks));
4100                 assert!(
4101                         pre_update_monitor.update_monitor(&replay_update, &&broadcaster, &chanmon_cfgs[1].fee_estimator, &nodes[1].logger)
4102                         .is_err());
4103                 // Even though we error'd on the first update, we should still have generated an HTLC claim
4104                 // transaction
4105                 let txn_broadcasted = broadcaster.txn_broadcasted.lock().unwrap().split_off(0);
4106                 assert!(txn_broadcasted.len() >= 2);
4107                 let htlc_txn = txn_broadcasted.iter().filter(|tx| {
4108                         assert_eq!(tx.input.len(), 1);
4109                         tx.input[0].previous_output.txid == broadcast_tx.txid()
4110                 }).collect::<Vec<_>>();
4111                 assert_eq!(htlc_txn.len(), 2);
4112                 check_spends!(htlc_txn[0], broadcast_tx);
4113                 check_spends!(htlc_txn[1], broadcast_tx);
4114         }
4115         #[test]
4116         fn test_funding_spend_refuses_updates() {
4117                 do_test_funding_spend_refuses_updates(true);
4118                 do_test_funding_spend_refuses_updates(false);
4119         }
4120
4121         #[test]
4122         fn test_prune_preimages() {
4123                 let secp_ctx = Secp256k1::new();
4124                 let logger = Arc::new(TestLogger::new());
4125                 let broadcaster = Arc::new(TestBroadcaster {
4126                         txn_broadcasted: Mutex::new(Vec::new()),
4127                         blocks: Arc::new(Mutex::new(Vec::new()))
4128                 });
4129                 let fee_estimator = TestFeeEstimator { sat_per_kw: Mutex::new(253) };
4130
4131                 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
4132
4133                 let mut preimages = Vec::new();
4134                 {
4135                         for i in 0..20 {
4136                                 let preimage = PaymentPreimage([i; 32]);
4137                                 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
4138                                 preimages.push((preimage, hash));
4139                         }
4140                 }
4141
4142                 macro_rules! preimages_slice_to_htlc_outputs {
4143                         ($preimages_slice: expr) => {
4144                                 {
4145                                         let mut res = Vec::new();
4146                                         for (idx, preimage) in $preimages_slice.iter().enumerate() {
4147                                                 res.push((HTLCOutputInCommitment {
4148                                                         offered: true,
4149                                                         amount_msat: 0,
4150                                                         cltv_expiry: 0,
4151                                                         payment_hash: preimage.1.clone(),
4152                                                         transaction_output_index: Some(idx as u32),
4153                                                 }, None));
4154                                         }
4155                                         res
4156                                 }
4157                         }
4158                 }
4159                 macro_rules! preimages_to_holder_htlcs {
4160                         ($preimages_slice: expr) => {
4161                                 {
4162                                         let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
4163                                         let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
4164                                         res
4165                                 }
4166                         }
4167                 }
4168
4169                 macro_rules! test_preimages_exist {
4170                         ($preimages_slice: expr, $monitor: expr) => {
4171                                 for preimage in $preimages_slice {
4172                                         assert!($monitor.inner.lock().unwrap().payment_preimages.contains_key(&preimage.1));
4173                                 }
4174                         }
4175                 }
4176
4177                 let keys = InMemorySigner::new(
4178                         &secp_ctx,
4179                         SecretKey::from_slice(&[41; 32]).unwrap(),
4180                         SecretKey::from_slice(&[41; 32]).unwrap(),
4181                         SecretKey::from_slice(&[41; 32]).unwrap(),
4182                         SecretKey::from_slice(&[41; 32]).unwrap(),
4183                         SecretKey::from_slice(&[41; 32]).unwrap(),
4184                         [41; 32],
4185                         0,
4186                         [0; 32],
4187                 );
4188
4189                 let counterparty_pubkeys = ChannelPublicKeys {
4190                         funding_pubkey: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
4191                         revocation_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
4192                         payment_point: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[46; 32]).unwrap()),
4193                         delayed_payment_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[47; 32]).unwrap()),
4194                         htlc_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[48; 32]).unwrap())
4195                 };
4196                 let funding_outpoint = OutPoint { txid: Txid::all_zeros(), index: u16::max_value() };
4197                 let channel_parameters = ChannelTransactionParameters {
4198                         holder_pubkeys: keys.holder_channel_pubkeys.clone(),
4199                         holder_selected_contest_delay: 66,
4200                         is_outbound_from_holder: true,
4201                         counterparty_parameters: Some(CounterpartyChannelTransactionParameters {
4202                                 pubkeys: counterparty_pubkeys,
4203                                 selected_contest_delay: 67,
4204                         }),
4205                         funding_outpoint: Some(funding_outpoint),
4206                         opt_anchors: None,
4207                         opt_non_zero_fee_anchors: None,
4208                 };
4209                 // Prune with one old state and a holder commitment tx holding a few overlaps with the
4210                 // old state.
4211                 let shutdown_pubkey = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
4212                 let best_block = BestBlock::from_network(Network::Testnet);
4213                 let monitor = ChannelMonitor::new(Secp256k1::new(), keys,
4214                                                   Some(ShutdownScript::new_p2wpkh_from_pubkey(shutdown_pubkey).into_inner()), 0, &Script::new(),
4215                                                   (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
4216                                                   &channel_parameters,
4217                                                   Script::new(), 46, 0,
4218                                                   HolderCommitmentTransaction::dummy(), best_block, dummy_key);
4219
4220                 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..10])).unwrap();
4221                 monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"1").into_inner()),
4222                         preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
4223                 monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"2").into_inner()),
4224                         preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
4225                 for &(ref preimage, ref hash) in preimages.iter() {
4226                         let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&fee_estimator);
4227                         monitor.provide_payment_preimage(hash, preimage, &broadcaster, &bounded_fee_estimator, &logger);
4228                 }
4229
4230                 // Now provide a secret, pruning preimages 10-15
4231                 let mut secret = [0; 32];
4232                 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
4233                 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
4234                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 15);
4235                 test_preimages_exist!(&preimages[0..10], monitor);
4236                 test_preimages_exist!(&preimages[15..20], monitor);
4237
4238                 monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"3").into_inner()),
4239                         preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
4240
4241                 // Now provide a further secret, pruning preimages 15-17
4242                 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
4243                 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
4244                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 13);
4245                 test_preimages_exist!(&preimages[0..10], monitor);
4246                 test_preimages_exist!(&preimages[17..20], monitor);
4247
4248                 monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"4").into_inner()),
4249                         preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
4250
4251                 // Now update holder commitment tx info, pruning only element 18 as we still care about the
4252                 // previous commitment tx's preimages too
4253                 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..5])).unwrap();
4254                 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
4255                 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
4256                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 12);
4257                 test_preimages_exist!(&preimages[0..10], monitor);
4258                 test_preimages_exist!(&preimages[18..20], monitor);
4259
4260                 // But if we do it again, we'll prune 5-10
4261                 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..3])).unwrap();
4262                 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
4263                 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
4264                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 5);
4265                 test_preimages_exist!(&preimages[0..5], monitor);
4266         }
4267
4268         #[test]
4269         fn test_claim_txn_weight_computation() {
4270                 // We test Claim txn weight, knowing that we want expected weigth and
4271                 // not actual case to avoid sigs and time-lock delays hell variances.
4272
4273                 let secp_ctx = Secp256k1::new();
4274                 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
4275                 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
4276
4277                 macro_rules! sign_input {
4278                         ($sighash_parts: expr, $idx: expr, $amount: expr, $weight: expr, $sum_actual_sigs: expr, $opt_anchors: expr) => {
4279                                 let htlc = HTLCOutputInCommitment {
4280                                         offered: if *$weight == weight_revoked_offered_htlc($opt_anchors) || *$weight == weight_offered_htlc($opt_anchors) { true } else { false },
4281                                         amount_msat: 0,
4282                                         cltv_expiry: 2 << 16,
4283                                         payment_hash: PaymentHash([1; 32]),
4284                                         transaction_output_index: Some($idx as u32),
4285                                 };
4286                                 let redeem_script = if *$weight == WEIGHT_REVOKED_OUTPUT { chan_utils::get_revokeable_redeemscript(&pubkey, 256, &pubkey) } else { chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, $opt_anchors, &pubkey, &pubkey, &pubkey) };
4287                                 let sighash = hash_to_message!(&$sighash_parts.segwit_signature_hash($idx, &redeem_script, $amount, EcdsaSighashType::All).unwrap()[..]);
4288                                 let sig = secp_ctx.sign_ecdsa(&sighash, &privkey);
4289                                 let mut ser_sig = sig.serialize_der().to_vec();
4290                                 ser_sig.push(EcdsaSighashType::All as u8);
4291                                 $sum_actual_sigs += ser_sig.len();
4292                                 let witness = $sighash_parts.witness_mut($idx).unwrap();
4293                                 witness.push(ser_sig);
4294                                 if *$weight == WEIGHT_REVOKED_OUTPUT {
4295                                         witness.push(vec!(1));
4296                                 } else if *$weight == weight_revoked_offered_htlc($opt_anchors) || *$weight == weight_revoked_received_htlc($opt_anchors) {
4297                                         witness.push(pubkey.clone().serialize().to_vec());
4298                                 } else if *$weight == weight_received_htlc($opt_anchors) {
4299                                         witness.push(vec![0]);
4300                                 } else {
4301                                         witness.push(PaymentPreimage([1; 32]).0.to_vec());
4302                                 }
4303                                 witness.push(redeem_script.into_bytes());
4304                                 let witness = witness.to_vec();
4305                                 println!("witness[0] {}", witness[0].len());
4306                                 println!("witness[1] {}", witness[1].len());
4307                                 println!("witness[2] {}", witness[2].len());
4308                         }
4309                 }
4310
4311                 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
4312                 let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
4313
4314                 // Justice tx with 1 to_holder, 2 revoked offered HTLCs, 1 revoked received HTLCs
4315                 for &opt_anchors in [false, true].iter() {
4316                         let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
4317                         let mut sum_actual_sigs = 0;
4318                         for i in 0..4 {
4319                                 claim_tx.input.push(TxIn {
4320                                         previous_output: BitcoinOutPoint {
4321                                                 txid,
4322                                                 vout: i,
4323                                         },
4324                                         script_sig: Script::new(),
4325                                         sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
4326                                         witness: Witness::new(),
4327                                 });
4328                         }
4329                         claim_tx.output.push(TxOut {
4330                                 script_pubkey: script_pubkey.clone(),
4331                                 value: 0,
4332                         });
4333                         let base_weight = claim_tx.weight();
4334                         let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT, weight_revoked_offered_htlc(opt_anchors), weight_revoked_offered_htlc(opt_anchors), weight_revoked_received_htlc(opt_anchors)];
4335                         let mut inputs_total_weight = 2; // count segwit flags
4336                         {
4337                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
4338                                 for (idx, inp) in inputs_weight.iter().enumerate() {
4339                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
4340                                         inputs_total_weight += inp;
4341                                 }
4342                         }
4343                         assert_eq!(base_weight + inputs_total_weight as usize,  claim_tx.weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
4344                 }
4345
4346                 // Claim tx with 1 offered HTLCs, 3 received HTLCs
4347                 for &opt_anchors in [false, true].iter() {
4348                         let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
4349                         let mut sum_actual_sigs = 0;
4350                         for i in 0..4 {
4351                                 claim_tx.input.push(TxIn {
4352                                         previous_output: BitcoinOutPoint {
4353                                                 txid,
4354                                                 vout: i,
4355                                         },
4356                                         script_sig: Script::new(),
4357                                         sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
4358                                         witness: Witness::new(),
4359                                 });
4360                         }
4361                         claim_tx.output.push(TxOut {
4362                                 script_pubkey: script_pubkey.clone(),
4363                                 value: 0,
4364                         });
4365                         let base_weight = claim_tx.weight();
4366                         let inputs_weight = vec![weight_offered_htlc(opt_anchors), weight_received_htlc(opt_anchors), weight_received_htlc(opt_anchors), weight_received_htlc(opt_anchors)];
4367                         let mut inputs_total_weight = 2; // count segwit flags
4368                         {
4369                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
4370                                 for (idx, inp) in inputs_weight.iter().enumerate() {
4371                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
4372                                         inputs_total_weight += inp;
4373                                 }
4374                         }
4375                         assert_eq!(base_weight + inputs_total_weight as usize,  claim_tx.weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
4376                 }
4377
4378                 // Justice tx with 1 revoked HTLC-Success tx output
4379                 for &opt_anchors in [false, true].iter() {
4380                         let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
4381                         let mut sum_actual_sigs = 0;
4382                         claim_tx.input.push(TxIn {
4383                                 previous_output: BitcoinOutPoint {
4384                                         txid,
4385                                         vout: 0,
4386                                 },
4387                                 script_sig: Script::new(),
4388                                 sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
4389                                 witness: Witness::new(),
4390                         });
4391                         claim_tx.output.push(TxOut {
4392                                 script_pubkey: script_pubkey.clone(),
4393                                 value: 0,
4394                         });
4395                         let base_weight = claim_tx.weight();
4396                         let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT];
4397                         let mut inputs_total_weight = 2; // count segwit flags
4398                         {
4399                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
4400                                 for (idx, inp) in inputs_weight.iter().enumerate() {
4401                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
4402                                         inputs_total_weight += inp;
4403                                 }
4404                         }
4405                         assert_eq!(base_weight + inputs_total_weight as usize, claim_tx.weight() + /* max_length_isg */ (73 * inputs_weight.len() - sum_actual_sigs));
4406                 }
4407         }
4408
4409         // Further testing is done in the ChannelManager integration tests.
4410 }