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Avoid refusing ChannelMonitorUpdates we expect to receive after closing
[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 latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date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 #[derive(Clone, PartialEq, Eq)]
73 #[must_use]
74 pub struct ChannelMonitorUpdate {
75         pub(crate) updates: Vec<ChannelMonitorUpdateStep>,
76         /// The sequence number of this update. Updates *must* be replayed in-order according to this
77         /// sequence number (and updates may panic if they are not). The update_id values are strictly
78         /// increasing and increase by one for each new update, with two exceptions specified below.
79         ///
80         /// This sequence number is also used to track up to which points updates which returned
81         /// [`ChannelMonitorUpdateStatus::InProgress`] have been applied to all copies of a given
82         /// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
83         ///
84         /// The only instances we allow where update_id values are not strictly increasing have a
85         /// special update ID of [`CLOSED_CHANNEL_UPDATE_ID`]. This update ID is used for updates that
86         /// will force close the channel by broadcasting the latest commitment transaction or
87         /// special post-force-close updates, like providing preimages necessary to claim outputs on the
88         /// broadcast commitment transaction. See its docs for more details.
89         ///
90         /// [`ChannelMonitorUpdateStatus::InProgress`]: super::ChannelMonitorUpdateStatus::InProgress
91         pub update_id: u64,
92 }
93
94 /// The update ID used for a [`ChannelMonitorUpdate`] that is either:
95 ///
96 ///     (1) attempting to force close the channel by broadcasting our latest commitment transaction or
97 ///     (2) providing a preimage (after the channel has been force closed) from a forward link that
98 ///             allows us to spend an HTLC output on this channel's (the backward link's) broadcasted
99 ///             commitment transaction.
100 ///
101 /// No other [`ChannelMonitorUpdate`]s are allowed after force-close.
102 pub const CLOSED_CHANNEL_UPDATE_ID: u64 = core::u64::MAX;
103
104 impl Writeable for ChannelMonitorUpdate {
105         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
106                 write_ver_prefix!(w, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
107                 self.update_id.write(w)?;
108                 (self.updates.len() as u64).write(w)?;
109                 for update_step in self.updates.iter() {
110                         update_step.write(w)?;
111                 }
112                 write_tlv_fields!(w, {});
113                 Ok(())
114         }
115 }
116 impl Readable for ChannelMonitorUpdate {
117         fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
118                 let _ver = read_ver_prefix!(r, SERIALIZATION_VERSION);
119                 let update_id: u64 = Readable::read(r)?;
120                 let len: u64 = Readable::read(r)?;
121                 let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::core::mem::size_of::<ChannelMonitorUpdateStep>()));
122                 for _ in 0..len {
123                         if let Some(upd) = MaybeReadable::read(r)? {
124                                 updates.push(upd);
125                         }
126                 }
127                 read_tlv_fields!(r, {});
128                 Ok(Self { update_id, updates })
129         }
130 }
131
132 /// An event to be processed by the ChannelManager.
133 #[derive(Clone, PartialEq, Eq)]
134 pub enum MonitorEvent {
135         /// A monitor event containing an HTLCUpdate.
136         HTLCEvent(HTLCUpdate),
137
138         /// A monitor event that the Channel's commitment transaction was confirmed.
139         CommitmentTxConfirmed(OutPoint),
140
141         /// Indicates a [`ChannelMonitor`] update has completed. See
142         /// [`ChannelMonitorUpdateStatus::InProgress`] for more information on how this is used.
143         ///
144         /// [`ChannelMonitorUpdateStatus::InProgress`]: super::ChannelMonitorUpdateStatus::InProgress
145         Completed {
146                 /// The funding outpoint of the [`ChannelMonitor`] that was updated
147                 funding_txo: OutPoint,
148                 /// The Update ID from [`ChannelMonitorUpdate::update_id`] which was applied or
149                 /// [`ChannelMonitor::get_latest_update_id`].
150                 ///
151                 /// Note that this should only be set to a given update's ID if all previous updates for the
152                 /// same [`ChannelMonitor`] have been applied and persisted.
153                 monitor_update_id: u64,
154         },
155
156         /// Indicates a [`ChannelMonitor`] update has failed. See
157         /// [`ChannelMonitorUpdateStatus::PermanentFailure`] for more information on how this is used.
158         ///
159         /// [`ChannelMonitorUpdateStatus::PermanentFailure`]: super::ChannelMonitorUpdateStatus::PermanentFailure
160         UpdateFailed(OutPoint),
161 }
162 impl_writeable_tlv_based_enum_upgradable!(MonitorEvent,
163         // Note that Completed and UpdateFailed are currently never serialized to disk as they are
164         // generated only in ChainMonitor
165         (0, Completed) => {
166                 (0, funding_txo, required),
167                 (2, monitor_update_id, required),
168         },
169 ;
170         (2, HTLCEvent),
171         (4, CommitmentTxConfirmed),
172         (6, UpdateFailed),
173 );
174
175 /// Simple structure sent back by `chain::Watch` when an HTLC from a forward channel is detected on
176 /// chain. Used to update the corresponding HTLC in the backward channel. Failing to pass the
177 /// preimage claim backward will lead to loss of funds.
178 #[derive(Clone, PartialEq, Eq)]
179 pub struct HTLCUpdate {
180         pub(crate) payment_hash: PaymentHash,
181         pub(crate) payment_preimage: Option<PaymentPreimage>,
182         pub(crate) source: HTLCSource,
183         pub(crate) htlc_value_satoshis: Option<u64>,
184 }
185 impl_writeable_tlv_based!(HTLCUpdate, {
186         (0, payment_hash, required),
187         (1, htlc_value_satoshis, option),
188         (2, source, required),
189         (4, payment_preimage, option),
190 });
191
192 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
193 /// instead claiming it in its own individual transaction.
194 pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
195 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
196 /// HTLC-Success transaction.
197 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
198 /// transaction confirmed (and we use it in a few more, equivalent, places).
199 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 18;
200 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
201 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
202 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
203 /// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
204 /// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
205 /// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
206 /// due to expiration but increase the cost of funds being locked longuer in case of failure.
207 /// This delay also cover a low-power peer being slow to process blocks and so being behind us on
208 /// accurate block height.
209 /// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
210 /// with at worst this delay, so we are not only using this value as a mercy for them but also
211 /// us as a safeguard to delay with enough time.
212 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
213 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding
214 /// inbound HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us
215 /// losing money.
216 ///
217 /// Note that this is a library-wide security assumption. If a reorg deeper than this number of
218 /// blocks occurs, counterparties may be able to steal funds or claims made by and balances exposed
219 /// by a  [`ChannelMonitor`] may be incorrect.
220 // We also use this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
221 // It may cause spurious generation of bumped claim txn but that's alright given the outpoint is already
222 // solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
223 // keep bumping another claim tx to solve the outpoint.
224 pub const ANTI_REORG_DELAY: u32 = 6;
225 /// Number of blocks before confirmation at which we fail back an un-relayed HTLC or at which we
226 /// refuse to accept a new HTLC.
227 ///
228 /// This is used for a few separate purposes:
229 /// 1) if we've received an MPP HTLC to us and it expires within this many blocks and we are
230 ///    waiting on additional parts (or waiting on the preimage for any HTLC from the user), we will
231 ///    fail this HTLC,
232 /// 2) if we receive an HTLC within this many blocks of its expiry (plus one to avoid a race
233 ///    condition with the above), we will fail this HTLC without telling the user we received it,
234 ///
235 /// (1) is all about protecting us - we need enough time to update the channel state before we hit
236 /// CLTV_CLAIM_BUFFER, at which point we'd go on chain to claim the HTLC with the preimage.
237 ///
238 /// (2) is the same, but with an additional buffer to avoid accepting an HTLC which is immediately
239 /// in a race condition between the user connecting a block (which would fail it) and the user
240 /// providing us the preimage (which would claim it).
241 pub(crate) const HTLC_FAIL_BACK_BUFFER: u32 = CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS;
242
243 // TODO(devrandom) replace this with HolderCommitmentTransaction
244 #[derive(Clone, PartialEq, Eq)]
245 struct HolderSignedTx {
246         /// txid of the transaction in tx, just used to make comparison faster
247         txid: Txid,
248         revocation_key: PublicKey,
249         a_htlc_key: PublicKey,
250         b_htlc_key: PublicKey,
251         delayed_payment_key: PublicKey,
252         per_commitment_point: PublicKey,
253         htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
254         to_self_value_sat: u64,
255         feerate_per_kw: u32,
256 }
257 impl_writeable_tlv_based!(HolderSignedTx, {
258         (0, txid, required),
259         // Note that this is filled in with data from OnchainTxHandler if it's missing.
260         // For HolderSignedTx objects serialized with 0.0.100+, this should be filled in.
261         (1, to_self_value_sat, (default_value, u64::max_value())),
262         (2, revocation_key, required),
263         (4, a_htlc_key, required),
264         (6, b_htlc_key, required),
265         (8, delayed_payment_key, required),
266         (10, per_commitment_point, required),
267         (12, feerate_per_kw, required),
268         (14, htlc_outputs, vec_type)
269 });
270
271 #[cfg(anchors)]
272 impl HolderSignedTx {
273         fn non_dust_htlcs(&self) -> Vec<HTLCOutputInCommitment> {
274                 self.htlc_outputs.iter().filter_map(|(htlc, _, _)| {
275                         if let Some(_) = htlc.transaction_output_index {
276                                 Some(htlc.clone())
277                         } else {
278                                 None
279                         }
280                 })
281                 .collect()
282         }
283 }
284
285 /// We use this to track static counterparty commitment transaction data and to generate any
286 /// justice or 2nd-stage preimage/timeout transactions.
287 #[derive(PartialEq, Eq)]
288 struct CounterpartyCommitmentParameters {
289         counterparty_delayed_payment_base_key: PublicKey,
290         counterparty_htlc_base_key: PublicKey,
291         on_counterparty_tx_csv: u16,
292 }
293
294 impl Writeable for CounterpartyCommitmentParameters {
295         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
296                 w.write_all(&(0 as u64).to_be_bytes())?;
297                 write_tlv_fields!(w, {
298                         (0, self.counterparty_delayed_payment_base_key, required),
299                         (2, self.counterparty_htlc_base_key, required),
300                         (4, self.on_counterparty_tx_csv, required),
301                 });
302                 Ok(())
303         }
304 }
305 impl Readable for CounterpartyCommitmentParameters {
306         fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
307                 let counterparty_commitment_transaction = {
308                         // Versions prior to 0.0.100 had some per-HTLC state stored here, which is no longer
309                         // used. Read it for compatibility.
310                         let per_htlc_len: u64 = Readable::read(r)?;
311                         for _  in 0..per_htlc_len {
312                                 let _txid: Txid = Readable::read(r)?;
313                                 let htlcs_count: u64 = Readable::read(r)?;
314                                 for _ in 0..htlcs_count {
315                                         let _htlc: HTLCOutputInCommitment = Readable::read(r)?;
316                                 }
317                         }
318
319                         let mut counterparty_delayed_payment_base_key = RequiredWrapper(None);
320                         let mut counterparty_htlc_base_key = RequiredWrapper(None);
321                         let mut on_counterparty_tx_csv: u16 = 0;
322                         read_tlv_fields!(r, {
323                                 (0, counterparty_delayed_payment_base_key, required),
324                                 (2, counterparty_htlc_base_key, required),
325                                 (4, on_counterparty_tx_csv, required),
326                         });
327                         CounterpartyCommitmentParameters {
328                                 counterparty_delayed_payment_base_key: counterparty_delayed_payment_base_key.0.unwrap(),
329                                 counterparty_htlc_base_key: counterparty_htlc_base_key.0.unwrap(),
330                                 on_counterparty_tx_csv,
331                         }
332                 };
333                 Ok(counterparty_commitment_transaction)
334         }
335 }
336
337 /// An entry for an [`OnchainEvent`], stating the block height and hash when the event was
338 /// observed, as well as the transaction causing it.
339 ///
340 /// Used to determine when the on-chain event can be considered safe from a chain reorganization.
341 #[derive(PartialEq, Eq)]
342 struct OnchainEventEntry {
343         txid: Txid,
344         height: u32,
345         block_hash: Option<BlockHash>, // Added as optional, will be filled in for any entry generated on 0.0.113 or after
346         event: OnchainEvent,
347         transaction: Option<Transaction>, // Added as optional, but always filled in, in LDK 0.0.110
348 }
349
350 impl OnchainEventEntry {
351         fn confirmation_threshold(&self) -> u32 {
352                 let mut conf_threshold = self.height + ANTI_REORG_DELAY - 1;
353                 match self.event {
354                         OnchainEvent::MaturingOutput {
355                                 descriptor: SpendableOutputDescriptor::DelayedPaymentOutput(ref descriptor)
356                         } => {
357                                 // A CSV'd transaction is confirmable in block (input height) + CSV delay, which means
358                                 // it's broadcastable when we see the previous block.
359                                 conf_threshold = cmp::max(conf_threshold, self.height + descriptor.to_self_delay as u32 - 1);
360                         },
361                         OnchainEvent::FundingSpendConfirmation { on_local_output_csv: Some(csv), .. } |
362                         OnchainEvent::HTLCSpendConfirmation { on_to_local_output_csv: Some(csv), .. } => {
363                                 // A CSV'd transaction is confirmable in block (input height) + CSV delay, which means
364                                 // it's broadcastable when we see the previous block.
365                                 conf_threshold = cmp::max(conf_threshold, self.height + csv as u32 - 1);
366                         },
367                         _ => {},
368                 }
369                 conf_threshold
370         }
371
372         fn has_reached_confirmation_threshold(&self, best_block: &BestBlock) -> bool {
373                 best_block.height() >= self.confirmation_threshold()
374         }
375 }
376
377 /// The (output index, sats value) for the counterparty's output in a commitment transaction.
378 ///
379 /// This was added as an `Option` in 0.0.110.
380 type CommitmentTxCounterpartyOutputInfo = Option<(u32, u64)>;
381
382 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
383 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
384 #[derive(PartialEq, Eq)]
385 enum OnchainEvent {
386         /// An outbound HTLC failing after a transaction is confirmed. Used
387         ///  * when an outbound HTLC output is spent by us after the HTLC timed out
388         ///  * an outbound HTLC which was not present in the commitment transaction which appeared
389         ///    on-chain (either because it was not fully committed to or it was dust).
390         /// Note that this is *not* used for preimage claims, as those are passed upstream immediately,
391         /// appearing only as an `HTLCSpendConfirmation`, below.
392         HTLCUpdate {
393                 source: HTLCSource,
394                 payment_hash: PaymentHash,
395                 htlc_value_satoshis: Option<u64>,
396                 /// None in the second case, above, ie when there is no relevant output in the commitment
397                 /// transaction which appeared on chain.
398                 commitment_tx_output_idx: Option<u32>,
399         },
400         /// An output waiting on [`ANTI_REORG_DELAY`] confirmations before we hand the user the
401         /// [`SpendableOutputDescriptor`].
402         MaturingOutput {
403                 descriptor: SpendableOutputDescriptor,
404         },
405         /// A spend of the funding output, either a commitment transaction or a cooperative closing
406         /// transaction.
407         FundingSpendConfirmation {
408                 /// The CSV delay for the output of the funding spend transaction (implying it is a local
409                 /// commitment transaction, and this is the delay on the to_self output).
410                 on_local_output_csv: Option<u16>,
411                 /// If the funding spend transaction was a known remote commitment transaction, we track
412                 /// the output index and amount of the counterparty's `to_self` output here.
413                 ///
414                 /// This allows us to generate a [`Balance::CounterpartyRevokedOutputClaimable`] for the
415                 /// counterparty output.
416                 commitment_tx_to_counterparty_output: CommitmentTxCounterpartyOutputInfo,
417         },
418         /// A spend of a commitment transaction HTLC output, set in the cases where *no* `HTLCUpdate`
419         /// is constructed. This is used when
420         ///  * an outbound HTLC is claimed by our counterparty with a preimage, causing us to
421         ///    immediately claim the HTLC on the inbound edge and track the resolution here,
422         ///  * an inbound HTLC is claimed by our counterparty (with a timeout),
423         ///  * an inbound HTLC is claimed by us (with a preimage).
424         ///  * a revoked-state HTLC transaction was broadcasted, which was claimed by the revocation
425         ///    signature.
426         ///  * a revoked-state HTLC transaction was broadcasted, which was claimed by an
427         ///    HTLC-Success/HTLC-Failure transaction (and is still claimable with a revocation
428         ///    signature).
429         HTLCSpendConfirmation {
430                 commitment_tx_output_idx: u32,
431                 /// If the claim was made by either party with a preimage, this is filled in
432                 preimage: Option<PaymentPreimage>,
433                 /// If the claim was made by us on an inbound HTLC against a local commitment transaction,
434                 /// we set this to the output CSV value which we will have to wait until to spend the
435                 /// output (and generate a SpendableOutput event).
436                 on_to_local_output_csv: Option<u16>,
437         },
438 }
439
440 impl Writeable for OnchainEventEntry {
441         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
442                 write_tlv_fields!(writer, {
443                         (0, self.txid, required),
444                         (1, self.transaction, option),
445                         (2, self.height, required),
446                         (3, self.block_hash, option),
447                         (4, self.event, required),
448                 });
449                 Ok(())
450         }
451 }
452
453 impl MaybeReadable for OnchainEventEntry {
454         fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, DecodeError> {
455                 let mut txid = Txid::all_zeros();
456                 let mut transaction = None;
457                 let mut block_hash = None;
458                 let mut height = 0;
459                 let mut event = UpgradableRequired(None);
460                 read_tlv_fields!(reader, {
461                         (0, txid, required),
462                         (1, transaction, option),
463                         (2, height, required),
464                         (3, block_hash, option),
465                         (4, event, upgradable_required),
466                 });
467                 Ok(Some(Self { txid, transaction, height, block_hash, event: _init_tlv_based_struct_field!(event, upgradable_required) }))
468         }
469 }
470
471 impl_writeable_tlv_based_enum_upgradable!(OnchainEvent,
472         (0, HTLCUpdate) => {
473                 (0, source, required),
474                 (1, htlc_value_satoshis, option),
475                 (2, payment_hash, required),
476                 (3, commitment_tx_output_idx, option),
477         },
478         (1, MaturingOutput) => {
479                 (0, descriptor, required),
480         },
481         (3, FundingSpendConfirmation) => {
482                 (0, on_local_output_csv, option),
483                 (1, commitment_tx_to_counterparty_output, option),
484         },
485         (5, HTLCSpendConfirmation) => {
486                 (0, commitment_tx_output_idx, required),
487                 (2, preimage, option),
488                 (4, on_to_local_output_csv, option),
489         },
490
491 );
492
493 #[derive(Clone, PartialEq, Eq)]
494 pub(crate) enum ChannelMonitorUpdateStep {
495         LatestHolderCommitmentTXInfo {
496                 commitment_tx: HolderCommitmentTransaction,
497                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
498                 claimed_htlcs: Vec<(SentHTLCId, PaymentPreimage)>,
499         },
500         LatestCounterpartyCommitmentTXInfo {
501                 commitment_txid: Txid,
502                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
503                 commitment_number: u64,
504                 their_per_commitment_point: PublicKey,
505         },
506         PaymentPreimage {
507                 payment_preimage: PaymentPreimage,
508         },
509         CommitmentSecret {
510                 idx: u64,
511                 secret: [u8; 32],
512         },
513         /// Used to indicate that the no future updates will occur, and likely that the latest holder
514         /// commitment transaction(s) should be broadcast, as the channel has been force-closed.
515         ChannelForceClosed {
516                 /// If set to false, we shouldn't broadcast the latest holder commitment transaction as we
517                 /// think we've fallen behind!
518                 should_broadcast: bool,
519         },
520         ShutdownScript {
521                 scriptpubkey: Script,
522         },
523 }
524
525 impl ChannelMonitorUpdateStep {
526         fn variant_name(&self) -> &'static str {
527                 match self {
528                         ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { .. } => "LatestHolderCommitmentTXInfo",
529                         ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { .. } => "LatestCounterpartyCommitmentTXInfo",
530                         ChannelMonitorUpdateStep::PaymentPreimage { .. } => "PaymentPreimage",
531                         ChannelMonitorUpdateStep::CommitmentSecret { .. } => "CommitmentSecret",
532                         ChannelMonitorUpdateStep::ChannelForceClosed { .. } => "ChannelForceClosed",
533                         ChannelMonitorUpdateStep::ShutdownScript { .. } => "ShutdownScript",
534                 }
535         }
536 }
537
538 impl_writeable_tlv_based_enum_upgradable!(ChannelMonitorUpdateStep,
539         (0, LatestHolderCommitmentTXInfo) => {
540                 (0, commitment_tx, required),
541                 (1, claimed_htlcs, vec_type),
542                 (2, htlc_outputs, vec_type),
543         },
544         (1, LatestCounterpartyCommitmentTXInfo) => {
545                 (0, commitment_txid, required),
546                 (2, commitment_number, required),
547                 (4, their_per_commitment_point, required),
548                 (6, htlc_outputs, vec_type),
549         },
550         (2, PaymentPreimage) => {
551                 (0, payment_preimage, required),
552         },
553         (3, CommitmentSecret) => {
554                 (0, idx, required),
555                 (2, secret, required),
556         },
557         (4, ChannelForceClosed) => {
558                 (0, should_broadcast, required),
559         },
560         (5, ShutdownScript) => {
561                 (0, scriptpubkey, required),
562         },
563 );
564
565 /// Details about the balance(s) available for spending once the channel appears on chain.
566 ///
567 /// See [`ChannelMonitor::get_claimable_balances`] for more details on when these will or will not
568 /// be provided.
569 #[derive(Clone, Debug, PartialEq, Eq)]
570 #[cfg_attr(test, derive(PartialOrd, Ord))]
571 pub enum Balance {
572         /// The channel is not yet closed (or the commitment or closing transaction has not yet
573         /// appeared in a block). The given balance is claimable (less on-chain fees) if the channel is
574         /// force-closed now.
575         ClaimableOnChannelClose {
576                 /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
577                 /// required to do so.
578                 claimable_amount_satoshis: u64,
579         },
580         /// The channel has been closed, and the given balance is ours but awaiting confirmations until
581         /// we consider it spendable.
582         ClaimableAwaitingConfirmations {
583                 /// The amount available to claim, in satoshis, possibly excluding the on-chain fees which
584                 /// were spent in broadcasting the transaction.
585                 claimable_amount_satoshis: u64,
586                 /// The height at which an [`Event::SpendableOutputs`] event will be generated for this
587                 /// amount.
588                 confirmation_height: u32,
589         },
590         /// The channel has been closed, and the given balance should be ours but awaiting spending
591         /// transaction confirmation. If the spending transaction does not confirm in time, it is
592         /// possible our counterparty can take the funds by broadcasting an HTLC timeout on-chain.
593         ///
594         /// Once the spending transaction confirms, before it has reached enough confirmations to be
595         /// considered safe from chain reorganizations, the balance will instead be provided via
596         /// [`Balance::ClaimableAwaitingConfirmations`].
597         ContentiousClaimable {
598                 /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
599                 /// required to do so.
600                 claimable_amount_satoshis: u64,
601                 /// The height at which the counterparty may be able to claim the balance if we have not
602                 /// done so.
603                 timeout_height: u32,
604         },
605         /// HTLCs which we sent to our counterparty which are claimable after a timeout (less on-chain
606         /// fees) if the counterparty does not know the preimage for the HTLCs. These are somewhat
607         /// likely to be claimed by our counterparty before we do.
608         MaybeTimeoutClaimableHTLC {
609                 /// The amount potentially available to claim, in satoshis, excluding the on-chain fees
610                 /// which will be required to do so.
611                 claimable_amount_satoshis: u64,
612                 /// The height at which we will be able to claim the balance if our counterparty has not
613                 /// done so.
614                 claimable_height: u32,
615         },
616         /// HTLCs which we received from our counterparty which are claimable with a preimage which we
617         /// do not currently have. This will only be claimable if we receive the preimage from the node
618         /// to which we forwarded this HTLC before the timeout.
619         MaybePreimageClaimableHTLC {
620                 /// The amount potentially available to claim, in satoshis, excluding the on-chain fees
621                 /// which will be required to do so.
622                 claimable_amount_satoshis: u64,
623                 /// The height at which our counterparty will be able to claim the balance if we have not
624                 /// yet received the preimage and claimed it ourselves.
625                 expiry_height: u32,
626         },
627         /// The channel has been closed, and our counterparty broadcasted a revoked commitment
628         /// transaction.
629         ///
630         /// Thus, we're able to claim all outputs in the commitment transaction, one of which has the
631         /// following amount.
632         CounterpartyRevokedOutputClaimable {
633                 /// The amount, in satoshis, of the output which we can claim.
634                 ///
635                 /// Note that for outputs from HTLC balances this may be excluding some on-chain fees that
636                 /// were already spent.
637                 claimable_amount_satoshis: u64,
638         },
639 }
640
641 /// An HTLC which has been irrevocably resolved on-chain, and has reached ANTI_REORG_DELAY.
642 #[derive(PartialEq, Eq)]
643 struct IrrevocablyResolvedHTLC {
644         commitment_tx_output_idx: Option<u32>,
645         /// The txid of the transaction which resolved the HTLC, this may be a commitment (if the HTLC
646         /// was not present in the confirmed commitment transaction), HTLC-Success, or HTLC-Timeout
647         /// transaction.
648         resolving_txid: Option<Txid>, // Added as optional, but always filled in, in 0.0.110
649         resolving_tx: Option<Transaction>,
650         /// Only set if the HTLC claim was ours using a payment preimage
651         payment_preimage: Option<PaymentPreimage>,
652 }
653
654 // In LDK versions prior to 0.0.111 commitment_tx_output_idx was not Option-al and
655 // IrrevocablyResolvedHTLC objects only existed for non-dust HTLCs. This was a bug, but to maintain
656 // backwards compatibility we must ensure we always write out a commitment_tx_output_idx field,
657 // using `u32::max_value()` as a sentinal to indicate the HTLC was dust.
658 impl Writeable for IrrevocablyResolvedHTLC {
659         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
660                 let mapped_commitment_tx_output_idx = self.commitment_tx_output_idx.unwrap_or(u32::max_value());
661                 write_tlv_fields!(writer, {
662                         (0, mapped_commitment_tx_output_idx, required),
663                         (1, self.resolving_txid, option),
664                         (2, self.payment_preimage, option),
665                         (3, self.resolving_tx, option),
666                 });
667                 Ok(())
668         }
669 }
670
671 impl Readable for IrrevocablyResolvedHTLC {
672         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
673                 let mut mapped_commitment_tx_output_idx = 0;
674                 let mut resolving_txid = None;
675                 let mut payment_preimage = None;
676                 let mut resolving_tx = None;
677                 read_tlv_fields!(reader, {
678                         (0, mapped_commitment_tx_output_idx, required),
679                         (1, resolving_txid, option),
680                         (2, payment_preimage, option),
681                         (3, resolving_tx, option),
682                 });
683                 Ok(Self {
684                         commitment_tx_output_idx: if mapped_commitment_tx_output_idx == u32::max_value() { None } else { Some(mapped_commitment_tx_output_idx) },
685                         resolving_txid,
686                         payment_preimage,
687                         resolving_tx,
688                 })
689         }
690 }
691
692 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
693 /// on-chain transactions to ensure no loss of funds occurs.
694 ///
695 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
696 /// information and are actively monitoring the chain.
697 ///
698 /// Pending Events or updated HTLCs which have not yet been read out by
699 /// get_and_clear_pending_monitor_events or get_and_clear_pending_events are serialized to disk and
700 /// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
701 /// gotten are fully handled before re-serializing the new state.
702 ///
703 /// Note that the deserializer is only implemented for (BlockHash, ChannelMonitor), which
704 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
705 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
706 /// returned block hash and the the current chain and then reconnecting blocks to get to the
707 /// best chain) upon deserializing the object!
708 pub struct ChannelMonitor<Signer: WriteableEcdsaChannelSigner> {
709         #[cfg(test)]
710         pub(crate) inner: Mutex<ChannelMonitorImpl<Signer>>,
711         #[cfg(not(test))]
712         inner: Mutex<ChannelMonitorImpl<Signer>>,
713 }
714
715 #[derive(PartialEq)]
716 pub(crate) struct ChannelMonitorImpl<Signer: WriteableEcdsaChannelSigner> {
717         latest_update_id: u64,
718         commitment_transaction_number_obscure_factor: u64,
719
720         destination_script: Script,
721         broadcasted_holder_revokable_script: Option<(Script, PublicKey, PublicKey)>,
722         counterparty_payment_script: Script,
723         shutdown_script: Option<Script>,
724
725         channel_keys_id: [u8; 32],
726         holder_revocation_basepoint: PublicKey,
727         funding_info: (OutPoint, Script),
728         current_counterparty_commitment_txid: Option<Txid>,
729         prev_counterparty_commitment_txid: Option<Txid>,
730
731         counterparty_commitment_params: CounterpartyCommitmentParameters,
732         funding_redeemscript: Script,
733         channel_value_satoshis: u64,
734         // first is the idx of the first of the two per-commitment points
735         their_cur_per_commitment_points: Option<(u64, PublicKey, Option<PublicKey>)>,
736
737         on_holder_tx_csv: u16,
738
739         commitment_secrets: CounterpartyCommitmentSecrets,
740         /// The set of outpoints in each counterparty commitment transaction. We always need at least
741         /// the payment hash from `HTLCOutputInCommitment` to claim even a revoked commitment
742         /// transaction broadcast as we need to be able to construct the witness script in all cases.
743         counterparty_claimable_outpoints: HashMap<Txid, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
744         /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
745         /// Nor can we figure out their commitment numbers without the commitment transaction they are
746         /// spending. Thus, in order to claim them via revocation key, we track all the counterparty
747         /// commitment transactions which we find on-chain, mapping them to the commitment number which
748         /// can be used to derive the revocation key and claim the transactions.
749         counterparty_commitment_txn_on_chain: HashMap<Txid, u64>,
750         /// Cache used to make pruning of payment_preimages faster.
751         /// Maps payment_hash values to commitment numbers for counterparty transactions for non-revoked
752         /// counterparty transactions (ie should remain pretty small).
753         /// Serialized to disk but should generally not be sent to Watchtowers.
754         counterparty_hash_commitment_number: HashMap<PaymentHash, u64>,
755
756         counterparty_fulfilled_htlcs: HashMap<SentHTLCId, PaymentPreimage>,
757
758         // We store two holder commitment transactions to avoid any race conditions where we may update
759         // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
760         // various monitors for one channel being out of sync, and us broadcasting a holder
761         // transaction for which we have deleted claim information on some watchtowers.
762         prev_holder_signed_commitment_tx: Option<HolderSignedTx>,
763         current_holder_commitment_tx: HolderSignedTx,
764
765         // Used just for ChannelManager to make sure it has the latest channel data during
766         // deserialization
767         current_counterparty_commitment_number: u64,
768         // Used just for ChannelManager to make sure it has the latest channel data during
769         // deserialization
770         current_holder_commitment_number: u64,
771
772         /// The set of payment hashes from inbound payments for which we know the preimage. Payment
773         /// preimages that are not included in any unrevoked local commitment transaction or unrevoked
774         /// remote commitment transactions are automatically removed when commitment transactions are
775         /// revoked.
776         payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
777
778         // Note that `MonitorEvent`s MUST NOT be generated during update processing, only generated
779         // during chain data processing. This prevents a race in `ChainMonitor::update_channel` (and
780         // presumably user implementations thereof as well) where we update the in-memory channel
781         // object, then before the persistence finishes (as it's all under a read-lock), we return
782         // pending events to the user or to the relevant `ChannelManager`. Then, on reload, we'll have
783         // the pre-event state here, but have processed the event in the `ChannelManager`.
784         // Note that because the `event_lock` in `ChainMonitor` is only taken in
785         // block/transaction-connected events and *not* during block/transaction-disconnected events,
786         // we further MUST NOT generate events during block/transaction-disconnection.
787         pending_monitor_events: Vec<MonitorEvent>,
788
789         pending_events: Vec<Event>,
790
791         // Used to track on-chain events (i.e., transactions part of channels confirmed on chain) on
792         // which to take actions once they reach enough confirmations. Each entry includes the
793         // transaction's id and the height when the transaction was confirmed on chain.
794         onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
795
796         // If we get serialized out and re-read, we need to make sure that the chain monitoring
797         // interface knows about the TXOs that we want to be notified of spends of. We could probably
798         // be smart and derive them from the above storage fields, but its much simpler and more
799         // Obviously Correct (tm) if we just keep track of them explicitly.
800         outputs_to_watch: HashMap<Txid, Vec<(u32, Script)>>,
801
802         #[cfg(test)]
803         pub onchain_tx_handler: OnchainTxHandler<Signer>,
804         #[cfg(not(test))]
805         onchain_tx_handler: OnchainTxHandler<Signer>,
806
807         // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
808         // channel has been force-closed. After this is set, no further holder commitment transaction
809         // updates may occur, and we panic!() if one is provided.
810         lockdown_from_offchain: bool,
811
812         // Set once we've signed a holder commitment transaction and handed it over to our
813         // OnchainTxHandler. After this is set, no future updates to our holder commitment transactions
814         // may occur, and we fail any such monitor updates.
815         //
816         // In case of update rejection due to a locally already signed commitment transaction, we
817         // nevertheless store update content to track in case of concurrent broadcast by another
818         // remote monitor out-of-order with regards to the block view.
819         holder_tx_signed: bool,
820
821         // If a spend of the funding output is seen, we set this to true and reject any further
822         // updates. This prevents any further changes in the offchain state no matter the order
823         // of block connection between ChannelMonitors and the ChannelManager.
824         funding_spend_seen: bool,
825
826         /// Set to `Some` of the confirmed transaction spending the funding input of the channel after
827         /// reaching `ANTI_REORG_DELAY` confirmations.
828         funding_spend_confirmed: Option<Txid>,
829
830         confirmed_commitment_tx_counterparty_output: CommitmentTxCounterpartyOutputInfo,
831         /// The set of HTLCs which have been either claimed or failed on chain and have reached
832         /// the requisite confirmations on the claim/fail transaction (either ANTI_REORG_DELAY or the
833         /// spending CSV for revocable outputs).
834         htlcs_resolved_on_chain: Vec<IrrevocablyResolvedHTLC>,
835
836         /// The set of `SpendableOutput` events which we have already passed upstream to be claimed.
837         /// These are tracked explicitly to ensure that we don't generate the same events redundantly
838         /// if users duplicatively confirm old transactions. Specifically for transactions claiming a
839         /// revoked remote outpoint we otherwise have no tracking at all once they've reached
840         /// [`ANTI_REORG_DELAY`], so we have to track them here.
841         spendable_txids_confirmed: Vec<Txid>,
842
843         // We simply modify best_block in Channel's block_connected so that serialization is
844         // consistent but hopefully the users' copy handles block_connected in a consistent way.
845         // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
846         // their best_block from its state and not based on updated copies that didn't run through
847         // the full block_connected).
848         best_block: BestBlock,
849
850         /// The node_id of our counterparty
851         counterparty_node_id: Option<PublicKey>,
852 }
853
854 /// Transaction outputs to watch for on-chain spends.
855 pub type TransactionOutputs = (Txid, Vec<(u32, TxOut)>);
856
857 impl<Signer: WriteableEcdsaChannelSigner> PartialEq for ChannelMonitor<Signer> where Signer: PartialEq {
858         fn eq(&self, other: &Self) -> bool {
859                 // We need some kind of total lockorder. Absent a better idea, we sort by position in
860                 // memory and take locks in that order (assuming that we can't move within memory while a
861                 // lock is held).
862                 let ord = ((self as *const _) as usize) < ((other as *const _) as usize);
863                 let a = if ord { self.inner.unsafe_well_ordered_double_lock_self() } else { other.inner.unsafe_well_ordered_double_lock_self() };
864                 let b = if ord { other.inner.unsafe_well_ordered_double_lock_self() } else { self.inner.unsafe_well_ordered_double_lock_self() };
865                 a.eq(&b)
866         }
867 }
868
869 impl<Signer: WriteableEcdsaChannelSigner> Writeable for ChannelMonitor<Signer> {
870         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
871                 self.inner.lock().unwrap().write(writer)
872         }
873 }
874
875 // These are also used for ChannelMonitorUpdate, above.
876 const SERIALIZATION_VERSION: u8 = 1;
877 const MIN_SERIALIZATION_VERSION: u8 = 1;
878
879 impl<Signer: WriteableEcdsaChannelSigner> Writeable for ChannelMonitorImpl<Signer> {
880         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
881                 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
882
883                 self.latest_update_id.write(writer)?;
884
885                 // Set in initial Channel-object creation, so should always be set by now:
886                 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
887
888                 self.destination_script.write(writer)?;
889                 if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
890                         writer.write_all(&[0; 1])?;
891                         broadcasted_holder_revokable_script.0.write(writer)?;
892                         broadcasted_holder_revokable_script.1.write(writer)?;
893                         broadcasted_holder_revokable_script.2.write(writer)?;
894                 } else {
895                         writer.write_all(&[1; 1])?;
896                 }
897
898                 self.counterparty_payment_script.write(writer)?;
899                 match &self.shutdown_script {
900                         Some(script) => script.write(writer)?,
901                         None => Script::new().write(writer)?,
902                 }
903
904                 self.channel_keys_id.write(writer)?;
905                 self.holder_revocation_basepoint.write(writer)?;
906                 writer.write_all(&self.funding_info.0.txid[..])?;
907                 writer.write_all(&self.funding_info.0.index.to_be_bytes())?;
908                 self.funding_info.1.write(writer)?;
909                 self.current_counterparty_commitment_txid.write(writer)?;
910                 self.prev_counterparty_commitment_txid.write(writer)?;
911
912                 self.counterparty_commitment_params.write(writer)?;
913                 self.funding_redeemscript.write(writer)?;
914                 self.channel_value_satoshis.write(writer)?;
915
916                 match self.their_cur_per_commitment_points {
917                         Some((idx, pubkey, second_option)) => {
918                                 writer.write_all(&byte_utils::be48_to_array(idx))?;
919                                 writer.write_all(&pubkey.serialize())?;
920                                 match second_option {
921                                         Some(second_pubkey) => {
922                                                 writer.write_all(&second_pubkey.serialize())?;
923                                         },
924                                         None => {
925                                                 writer.write_all(&[0; 33])?;
926                                         },
927                                 }
928                         },
929                         None => {
930                                 writer.write_all(&byte_utils::be48_to_array(0))?;
931                         },
932                 }
933
934                 writer.write_all(&self.on_holder_tx_csv.to_be_bytes())?;
935
936                 self.commitment_secrets.write(writer)?;
937
938                 macro_rules! serialize_htlc_in_commitment {
939                         ($htlc_output: expr) => {
940                                 writer.write_all(&[$htlc_output.offered as u8; 1])?;
941                                 writer.write_all(&$htlc_output.amount_msat.to_be_bytes())?;
942                                 writer.write_all(&$htlc_output.cltv_expiry.to_be_bytes())?;
943                                 writer.write_all(&$htlc_output.payment_hash.0[..])?;
944                                 $htlc_output.transaction_output_index.write(writer)?;
945                         }
946                 }
947
948                 writer.write_all(&(self.counterparty_claimable_outpoints.len() as u64).to_be_bytes())?;
949                 for (ref txid, ref htlc_infos) in self.counterparty_claimable_outpoints.iter() {
950                         writer.write_all(&txid[..])?;
951                         writer.write_all(&(htlc_infos.len() as u64).to_be_bytes())?;
952                         for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
953                                 debug_assert!(htlc_source.is_none() || Some(**txid) == self.current_counterparty_commitment_txid
954                                                 || Some(**txid) == self.prev_counterparty_commitment_txid,
955                                         "HTLC Sources for all revoked commitment transactions should be none!");
956                                 serialize_htlc_in_commitment!(htlc_output);
957                                 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
958                         }
959                 }
960
961                 writer.write_all(&(self.counterparty_commitment_txn_on_chain.len() as u64).to_be_bytes())?;
962                 for (ref txid, commitment_number) in self.counterparty_commitment_txn_on_chain.iter() {
963                         writer.write_all(&txid[..])?;
964                         writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
965                 }
966
967                 writer.write_all(&(self.counterparty_hash_commitment_number.len() as u64).to_be_bytes())?;
968                 for (ref payment_hash, commitment_number) in self.counterparty_hash_commitment_number.iter() {
969                         writer.write_all(&payment_hash.0[..])?;
970                         writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
971                 }
972
973                 if let Some(ref prev_holder_tx) = self.prev_holder_signed_commitment_tx {
974                         writer.write_all(&[1; 1])?;
975                         prev_holder_tx.write(writer)?;
976                 } else {
977                         writer.write_all(&[0; 1])?;
978                 }
979
980                 self.current_holder_commitment_tx.write(writer)?;
981
982                 writer.write_all(&byte_utils::be48_to_array(self.current_counterparty_commitment_number))?;
983                 writer.write_all(&byte_utils::be48_to_array(self.current_holder_commitment_number))?;
984
985                 writer.write_all(&(self.payment_preimages.len() as u64).to_be_bytes())?;
986                 for payment_preimage in self.payment_preimages.values() {
987                         writer.write_all(&payment_preimage.0[..])?;
988                 }
989
990                 writer.write_all(&(self.pending_monitor_events.iter().filter(|ev| match ev {
991                         MonitorEvent::HTLCEvent(_) => true,
992                         MonitorEvent::CommitmentTxConfirmed(_) => true,
993                         _ => false,
994                 }).count() as u64).to_be_bytes())?;
995                 for event in self.pending_monitor_events.iter() {
996                         match event {
997                                 MonitorEvent::HTLCEvent(upd) => {
998                                         0u8.write(writer)?;
999                                         upd.write(writer)?;
1000                                 },
1001                                 MonitorEvent::CommitmentTxConfirmed(_) => 1u8.write(writer)?,
1002                                 _ => {}, // Covered in the TLV writes below
1003                         }
1004                 }
1005
1006                 writer.write_all(&(self.pending_events.len() as u64).to_be_bytes())?;
1007                 for event in self.pending_events.iter() {
1008                         event.write(writer)?;
1009                 }
1010
1011                 self.best_block.block_hash().write(writer)?;
1012                 writer.write_all(&self.best_block.height().to_be_bytes())?;
1013
1014                 writer.write_all(&(self.onchain_events_awaiting_threshold_conf.len() as u64).to_be_bytes())?;
1015                 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
1016                         entry.write(writer)?;
1017                 }
1018
1019                 (self.outputs_to_watch.len() as u64).write(writer)?;
1020                 for (txid, idx_scripts) in self.outputs_to_watch.iter() {
1021                         txid.write(writer)?;
1022                         (idx_scripts.len() as u64).write(writer)?;
1023                         for (idx, script) in idx_scripts.iter() {
1024                                 idx.write(writer)?;
1025                                 script.write(writer)?;
1026                         }
1027                 }
1028                 self.onchain_tx_handler.write(writer)?;
1029
1030                 self.lockdown_from_offchain.write(writer)?;
1031                 self.holder_tx_signed.write(writer)?;
1032
1033                 write_tlv_fields!(writer, {
1034                         (1, self.funding_spend_confirmed, option),
1035                         (3, self.htlcs_resolved_on_chain, vec_type),
1036                         (5, self.pending_monitor_events, vec_type),
1037                         (7, self.funding_spend_seen, required),
1038                         (9, self.counterparty_node_id, option),
1039                         (11, self.confirmed_commitment_tx_counterparty_output, option),
1040                         (13, self.spendable_txids_confirmed, vec_type),
1041                         (15, self.counterparty_fulfilled_htlcs, required),
1042                 });
1043
1044                 Ok(())
1045         }
1046 }
1047
1048 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
1049         /// For lockorder enforcement purposes, we need to have a single site which constructs the
1050         /// `inner` mutex, otherwise cases where we lock two monitors at the same time (eg in our
1051         /// PartialEq implementation) we may decide a lockorder violation has occurred.
1052         fn from_impl(imp: ChannelMonitorImpl<Signer>) -> Self {
1053                 ChannelMonitor { inner: Mutex::new(imp) }
1054         }
1055
1056         pub(crate) fn new(secp_ctx: Secp256k1<secp256k1::All>, keys: Signer, shutdown_script: Option<Script>,
1057                           on_counterparty_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
1058                           channel_parameters: &ChannelTransactionParameters,
1059                           funding_redeemscript: Script, channel_value_satoshis: u64,
1060                           commitment_transaction_number_obscure_factor: u64,
1061                           initial_holder_commitment_tx: HolderCommitmentTransaction,
1062                           best_block: BestBlock, counterparty_node_id: PublicKey) -> ChannelMonitor<Signer> {
1063
1064                 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
1065                 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
1066                 let counterparty_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
1067
1068                 let counterparty_channel_parameters = channel_parameters.counterparty_parameters.as_ref().unwrap();
1069                 let counterparty_delayed_payment_base_key = counterparty_channel_parameters.pubkeys.delayed_payment_basepoint;
1070                 let counterparty_htlc_base_key = counterparty_channel_parameters.pubkeys.htlc_basepoint;
1071                 let counterparty_commitment_params = CounterpartyCommitmentParameters { counterparty_delayed_payment_base_key, counterparty_htlc_base_key, on_counterparty_tx_csv };
1072
1073                 let channel_keys_id = keys.channel_keys_id();
1074                 let holder_revocation_basepoint = keys.pubkeys().revocation_basepoint;
1075
1076                 // block for Rust 1.34 compat
1077                 let (holder_commitment_tx, current_holder_commitment_number) = {
1078                         let trusted_tx = initial_holder_commitment_tx.trust();
1079                         let txid = trusted_tx.txid();
1080
1081                         let tx_keys = trusted_tx.keys();
1082                         let holder_commitment_tx = HolderSignedTx {
1083                                 txid,
1084                                 revocation_key: tx_keys.revocation_key,
1085                                 a_htlc_key: tx_keys.broadcaster_htlc_key,
1086                                 b_htlc_key: tx_keys.countersignatory_htlc_key,
1087                                 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
1088                                 per_commitment_point: tx_keys.per_commitment_point,
1089                                 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
1090                                 to_self_value_sat: initial_holder_commitment_tx.to_broadcaster_value_sat(),
1091                                 feerate_per_kw: trusted_tx.feerate_per_kw(),
1092                         };
1093                         (holder_commitment_tx, trusted_tx.commitment_number())
1094                 };
1095
1096                 let onchain_tx_handler =
1097                         OnchainTxHandler::new(destination_script.clone(), keys,
1098                         channel_parameters.clone(), initial_holder_commitment_tx, secp_ctx);
1099
1100                 let mut outputs_to_watch = HashMap::new();
1101                 outputs_to_watch.insert(funding_info.0.txid, vec![(funding_info.0.index as u32, funding_info.1.clone())]);
1102
1103                 Self::from_impl(ChannelMonitorImpl {
1104                         latest_update_id: 0,
1105                         commitment_transaction_number_obscure_factor,
1106
1107                         destination_script: destination_script.clone(),
1108                         broadcasted_holder_revokable_script: None,
1109                         counterparty_payment_script,
1110                         shutdown_script,
1111
1112                         channel_keys_id,
1113                         holder_revocation_basepoint,
1114                         funding_info,
1115                         current_counterparty_commitment_txid: None,
1116                         prev_counterparty_commitment_txid: None,
1117
1118                         counterparty_commitment_params,
1119                         funding_redeemscript,
1120                         channel_value_satoshis,
1121                         their_cur_per_commitment_points: None,
1122
1123                         on_holder_tx_csv: counterparty_channel_parameters.selected_contest_delay,
1124
1125                         commitment_secrets: CounterpartyCommitmentSecrets::new(),
1126                         counterparty_claimable_outpoints: HashMap::new(),
1127                         counterparty_commitment_txn_on_chain: HashMap::new(),
1128                         counterparty_hash_commitment_number: HashMap::new(),
1129                         counterparty_fulfilled_htlcs: HashMap::new(),
1130
1131                         prev_holder_signed_commitment_tx: None,
1132                         current_holder_commitment_tx: holder_commitment_tx,
1133                         current_counterparty_commitment_number: 1 << 48,
1134                         current_holder_commitment_number,
1135
1136                         payment_preimages: HashMap::new(),
1137                         pending_monitor_events: Vec::new(),
1138                         pending_events: Vec::new(),
1139
1140                         onchain_events_awaiting_threshold_conf: Vec::new(),
1141                         outputs_to_watch,
1142
1143                         onchain_tx_handler,
1144
1145                         lockdown_from_offchain: false,
1146                         holder_tx_signed: false,
1147                         funding_spend_seen: false,
1148                         funding_spend_confirmed: None,
1149                         confirmed_commitment_tx_counterparty_output: None,
1150                         htlcs_resolved_on_chain: Vec::new(),
1151                         spendable_txids_confirmed: Vec::new(),
1152
1153                         best_block,
1154                         counterparty_node_id: Some(counterparty_node_id),
1155                 })
1156         }
1157
1158         #[cfg(test)]
1159         fn provide_secret(&self, idx: u64, secret: [u8; 32]) -> Result<(), &'static str> {
1160                 self.inner.lock().unwrap().provide_secret(idx, secret)
1161         }
1162
1163         /// Informs this monitor of the latest counterparty (ie non-broadcastable) commitment transaction.
1164         /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1165         /// possibly future revocation/preimage information) to claim outputs where possible.
1166         /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1167         pub(crate) fn provide_latest_counterparty_commitment_tx<L: Deref>(
1168                 &self,
1169                 txid: Txid,
1170                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
1171                 commitment_number: u64,
1172                 their_per_commitment_point: PublicKey,
1173                 logger: &L,
1174         ) where L::Target: Logger {
1175                 self.inner.lock().unwrap().provide_latest_counterparty_commitment_tx(
1176                         txid, htlc_outputs, commitment_number, their_per_commitment_point, logger)
1177         }
1178
1179         #[cfg(test)]
1180         fn provide_latest_holder_commitment_tx(
1181                 &self, holder_commitment_tx: HolderCommitmentTransaction,
1182                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
1183         ) -> Result<(), ()> {
1184                 self.inner.lock().unwrap().provide_latest_holder_commitment_tx(holder_commitment_tx, htlc_outputs, &Vec::new()).map_err(|_| ())
1185         }
1186
1187         /// This is used to provide payment preimage(s) out-of-band during startup without updating the
1188         /// off-chain state with a new commitment transaction.
1189         pub(crate) fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(
1190                 &self,
1191                 payment_hash: &PaymentHash,
1192                 payment_preimage: &PaymentPreimage,
1193                 broadcaster: &B,
1194                 fee_estimator: &LowerBoundedFeeEstimator<F>,
1195                 logger: &L,
1196         ) where
1197                 B::Target: BroadcasterInterface,
1198                 F::Target: FeeEstimator,
1199                 L::Target: Logger,
1200         {
1201                 self.inner.lock().unwrap().provide_payment_preimage(
1202                         payment_hash, payment_preimage, broadcaster, fee_estimator, logger)
1203         }
1204
1205         pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(
1206                 &self,
1207                 broadcaster: &B,
1208                 logger: &L,
1209         ) where
1210                 B::Target: BroadcasterInterface,
1211                 L::Target: Logger,
1212         {
1213                 self.inner.lock().unwrap().broadcast_latest_holder_commitment_txn(broadcaster, logger);
1214         }
1215
1216         /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1217         /// itself.
1218         ///
1219         /// panics if the given update is not the next update by update_id.
1220         pub fn update_monitor<B: Deref, F: Deref, L: Deref>(
1221                 &self,
1222                 updates: &ChannelMonitorUpdate,
1223                 broadcaster: &B,
1224                 fee_estimator: F,
1225                 logger: &L,
1226         ) -> Result<(), ()>
1227         where
1228                 B::Target: BroadcasterInterface,
1229                 F::Target: FeeEstimator,
1230                 L::Target: Logger,
1231         {
1232                 self.inner.lock().unwrap().update_monitor(updates, broadcaster, fee_estimator, logger)
1233         }
1234
1235         /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1236         /// ChannelMonitor.
1237         pub fn get_latest_update_id(&self) -> u64 {
1238                 self.inner.lock().unwrap().get_latest_update_id()
1239         }
1240
1241         /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1242         pub fn get_funding_txo(&self) -> (OutPoint, Script) {
1243                 self.inner.lock().unwrap().get_funding_txo().clone()
1244         }
1245
1246         /// Gets a list of txids, with their output scripts (in the order they appear in the
1247         /// transaction), which we must learn about spends of via block_connected().
1248         pub fn get_outputs_to_watch(&self) -> Vec<(Txid, Vec<(u32, Script)>)> {
1249                 self.inner.lock().unwrap().get_outputs_to_watch()
1250                         .iter().map(|(txid, outputs)| (*txid, outputs.clone())).collect()
1251         }
1252
1253         /// Loads the funding txo and outputs to watch into the given `chain::Filter` by repeatedly
1254         /// calling `chain::Filter::register_output` and `chain::Filter::register_tx` until all outputs
1255         /// have been registered.
1256         pub fn load_outputs_to_watch<F: Deref>(&self, filter: &F) where F::Target: chain::Filter {
1257                 let lock = self.inner.lock().unwrap();
1258                 filter.register_tx(&lock.get_funding_txo().0.txid, &lock.get_funding_txo().1);
1259                 for (txid, outputs) in lock.get_outputs_to_watch().iter() {
1260                         for (index, script_pubkey) in outputs.iter() {
1261                                 assert!(*index <= u16::max_value() as u32);
1262                                 filter.register_output(WatchedOutput {
1263                                         block_hash: None,
1264                                         outpoint: OutPoint { txid: *txid, index: *index as u16 },
1265                                         script_pubkey: script_pubkey.clone(),
1266                                 });
1267                         }
1268                 }
1269         }
1270
1271         /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1272         /// ChannelManager via [`chain::Watch::release_pending_monitor_events`].
1273         pub fn get_and_clear_pending_monitor_events(&self) -> Vec<MonitorEvent> {
1274                 self.inner.lock().unwrap().get_and_clear_pending_monitor_events()
1275         }
1276
1277         /// Gets the list of pending events which were generated by previous actions, clearing the list
1278         /// in the process.
1279         ///
1280         /// This is called by the [`EventsProvider::process_pending_events`] implementation for
1281         /// [`ChainMonitor`].
1282         ///
1283         /// [`EventsProvider::process_pending_events`]: crate::util::events::EventsProvider::process_pending_events
1284         /// [`ChainMonitor`]: crate::chain::chainmonitor::ChainMonitor
1285         pub fn get_and_clear_pending_events(&self) -> Vec<Event> {
1286                 self.inner.lock().unwrap().get_and_clear_pending_events()
1287         }
1288
1289         pub(crate) fn get_min_seen_secret(&self) -> u64 {
1290                 self.inner.lock().unwrap().get_min_seen_secret()
1291         }
1292
1293         pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1294                 self.inner.lock().unwrap().get_cur_counterparty_commitment_number()
1295         }
1296
1297         pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
1298                 self.inner.lock().unwrap().get_cur_holder_commitment_number()
1299         }
1300
1301         /// Gets the `node_id` of the counterparty for this channel.
1302         ///
1303         /// Will be `None` for channels constructed on LDK versions prior to 0.0.110 and always `Some`
1304         /// otherwise.
1305         pub fn get_counterparty_node_id(&self) -> Option<PublicKey> {
1306                 self.inner.lock().unwrap().counterparty_node_id
1307         }
1308
1309         /// Used by ChannelManager deserialization to broadcast the latest holder state if its copy of
1310         /// the Channel was out-of-date.
1311         ///
1312         /// You may also use this to broadcast the latest local commitment transaction, either because
1313         /// a monitor update failed with [`ChannelMonitorUpdateStatus::PermanentFailure`] or because we've
1314         /// fallen behind (i.e. we've received proof that our counterparty side knows a revocation
1315         /// secret we gave them that they shouldn't know).
1316         ///
1317         /// Broadcasting these transactions in the second case is UNSAFE, as they allow counterparty
1318         /// side to punish you. Nevertheless you may want to broadcast them if counterparty doesn't
1319         /// close channel with their commitment transaction after a substantial amount of time. Best
1320         /// may be to contact the other node operator out-of-band to coordinate other options available
1321         /// to you. In any-case, the choice is up to you.
1322         ///
1323         /// [`ChannelMonitorUpdateStatus::PermanentFailure`]: super::ChannelMonitorUpdateStatus::PermanentFailure
1324         pub fn get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1325         where L::Target: Logger {
1326                 self.inner.lock().unwrap().get_latest_holder_commitment_txn(logger)
1327         }
1328
1329         /// Unsafe test-only version of get_latest_holder_commitment_txn used by our test framework
1330         /// to bypass HolderCommitmentTransaction state update lockdown after signature and generate
1331         /// revoked commitment transaction.
1332         #[cfg(any(test, feature = "unsafe_revoked_tx_signing"))]
1333         pub fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1334         where L::Target: Logger {
1335                 self.inner.lock().unwrap().unsafe_get_latest_holder_commitment_txn(logger)
1336         }
1337
1338         /// Processes transactions in a newly connected block, which may result in any of the following:
1339         /// - update the monitor's state against resolved HTLCs
1340         /// - punish the counterparty in the case of seeing a revoked commitment transaction
1341         /// - force close the channel and claim/timeout incoming/outgoing HTLCs if near expiration
1342         /// - detect settled outputs for later spending
1343         /// - schedule and bump any in-flight claims
1344         ///
1345         /// Returns any new outputs to watch from `txdata`; after called, these are also included in
1346         /// [`get_outputs_to_watch`].
1347         ///
1348         /// [`get_outputs_to_watch`]: #method.get_outputs_to_watch
1349         pub fn block_connected<B: Deref, F: Deref, L: Deref>(
1350                 &self,
1351                 header: &BlockHeader,
1352                 txdata: &TransactionData,
1353                 height: u32,
1354                 broadcaster: B,
1355                 fee_estimator: F,
1356                 logger: L,
1357         ) -> Vec<TransactionOutputs>
1358         where
1359                 B::Target: BroadcasterInterface,
1360                 F::Target: FeeEstimator,
1361                 L::Target: Logger,
1362         {
1363                 self.inner.lock().unwrap().block_connected(
1364                         header, txdata, height, broadcaster, fee_estimator, logger)
1365         }
1366
1367         /// Determines if the disconnected block contained any transactions of interest and updates
1368         /// appropriately.
1369         pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(
1370                 &self,
1371                 header: &BlockHeader,
1372                 height: u32,
1373                 broadcaster: B,
1374                 fee_estimator: F,
1375                 logger: L,
1376         ) where
1377                 B::Target: BroadcasterInterface,
1378                 F::Target: FeeEstimator,
1379                 L::Target: Logger,
1380         {
1381                 self.inner.lock().unwrap().block_disconnected(
1382                         header, height, broadcaster, fee_estimator, logger)
1383         }
1384
1385         /// Processes transactions confirmed in a block with the given header and height, returning new
1386         /// outputs to watch. See [`block_connected`] for details.
1387         ///
1388         /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
1389         /// blocks. See [`chain::Confirm`] for calling expectations.
1390         ///
1391         /// [`block_connected`]: Self::block_connected
1392         pub fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
1393                 &self,
1394                 header: &BlockHeader,
1395                 txdata: &TransactionData,
1396                 height: u32,
1397                 broadcaster: B,
1398                 fee_estimator: F,
1399                 logger: L,
1400         ) -> Vec<TransactionOutputs>
1401         where
1402                 B::Target: BroadcasterInterface,
1403                 F::Target: FeeEstimator,
1404                 L::Target: Logger,
1405         {
1406                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1407                 self.inner.lock().unwrap().transactions_confirmed(
1408                         header, txdata, height, broadcaster, &bounded_fee_estimator, logger)
1409         }
1410
1411         /// Processes a transaction that was reorganized out of the chain.
1412         ///
1413         /// Used instead of [`block_disconnected`] by clients that are notified of transactions rather
1414         /// than blocks. See [`chain::Confirm`] for calling expectations.
1415         ///
1416         /// [`block_disconnected`]: Self::block_disconnected
1417         pub fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
1418                 &self,
1419                 txid: &Txid,
1420                 broadcaster: B,
1421                 fee_estimator: F,
1422                 logger: L,
1423         ) where
1424                 B::Target: BroadcasterInterface,
1425                 F::Target: FeeEstimator,
1426                 L::Target: Logger,
1427         {
1428                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1429                 self.inner.lock().unwrap().transaction_unconfirmed(
1430                         txid, broadcaster, &bounded_fee_estimator, logger);
1431         }
1432
1433         /// Updates the monitor with the current best chain tip, returning new outputs to watch. See
1434         /// [`block_connected`] for details.
1435         ///
1436         /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
1437         /// blocks. See [`chain::Confirm`] for calling expectations.
1438         ///
1439         /// [`block_connected`]: Self::block_connected
1440         pub fn best_block_updated<B: Deref, F: Deref, L: Deref>(
1441                 &self,
1442                 header: &BlockHeader,
1443                 height: u32,
1444                 broadcaster: B,
1445                 fee_estimator: F,
1446                 logger: L,
1447         ) -> Vec<TransactionOutputs>
1448         where
1449                 B::Target: BroadcasterInterface,
1450                 F::Target: FeeEstimator,
1451                 L::Target: Logger,
1452         {
1453                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1454                 self.inner.lock().unwrap().best_block_updated(
1455                         header, height, broadcaster, &bounded_fee_estimator, logger)
1456         }
1457
1458         /// Returns the set of txids that should be monitored for re-organization out of the chain.
1459         pub fn get_relevant_txids(&self) -> Vec<(Txid, Option<BlockHash>)> {
1460                 let inner = self.inner.lock().unwrap();
1461                 let mut txids: Vec<(Txid, Option<BlockHash>)> = inner.onchain_events_awaiting_threshold_conf
1462                         .iter()
1463                         .map(|entry| (entry.txid, entry.block_hash))
1464                         .chain(inner.onchain_tx_handler.get_relevant_txids().into_iter())
1465                         .collect();
1466                 txids.sort_unstable();
1467                 txids.dedup();
1468                 txids
1469         }
1470
1471         /// Gets the latest best block which was connected either via the [`chain::Listen`] or
1472         /// [`chain::Confirm`] interfaces.
1473         pub fn current_best_block(&self) -> BestBlock {
1474                 self.inner.lock().unwrap().best_block.clone()
1475         }
1476 }
1477
1478 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
1479         /// Helper for get_claimable_balances which does the work for an individual HTLC, generating up
1480         /// to one `Balance` for the HTLC.
1481         fn get_htlc_balance(&self, htlc: &HTLCOutputInCommitment, holder_commitment: bool,
1482                 counterparty_revoked_commitment: bool, confirmed_txid: Option<Txid>)
1483         -> Option<Balance> {
1484                 let htlc_commitment_tx_output_idx =
1485                         if let Some(v) = htlc.transaction_output_index { v } else { return None; };
1486
1487                 let mut htlc_spend_txid_opt = None;
1488                 let mut htlc_spend_tx_opt = None;
1489                 let mut holder_timeout_spend_pending = None;
1490                 let mut htlc_spend_pending = None;
1491                 let mut holder_delayed_output_pending = None;
1492                 for event in self.onchain_events_awaiting_threshold_conf.iter() {
1493                         match event.event {
1494                                 OnchainEvent::HTLCUpdate { commitment_tx_output_idx, htlc_value_satoshis, .. }
1495                                 if commitment_tx_output_idx == Some(htlc_commitment_tx_output_idx) => {
1496                                         debug_assert!(htlc_spend_txid_opt.is_none());
1497                                         htlc_spend_txid_opt = Some(&event.txid);
1498                                         debug_assert!(htlc_spend_tx_opt.is_none());
1499                                         htlc_spend_tx_opt = event.transaction.as_ref();
1500                                         debug_assert!(holder_timeout_spend_pending.is_none());
1501                                         debug_assert_eq!(htlc_value_satoshis.unwrap(), htlc.amount_msat / 1000);
1502                                         holder_timeout_spend_pending = Some(event.confirmation_threshold());
1503                                 },
1504                                 OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, preimage, .. }
1505                                 if commitment_tx_output_idx == htlc_commitment_tx_output_idx => {
1506                                         debug_assert!(htlc_spend_txid_opt.is_none());
1507                                         htlc_spend_txid_opt = Some(&event.txid);
1508                                         debug_assert!(htlc_spend_tx_opt.is_none());
1509                                         htlc_spend_tx_opt = event.transaction.as_ref();
1510                                         debug_assert!(htlc_spend_pending.is_none());
1511                                         htlc_spend_pending = Some((event.confirmation_threshold(), preimage.is_some()));
1512                                 },
1513                                 OnchainEvent::MaturingOutput {
1514                                         descriptor: SpendableOutputDescriptor::DelayedPaymentOutput(ref descriptor) }
1515                                 if descriptor.outpoint.index as u32 == htlc_commitment_tx_output_idx => {
1516                                         debug_assert!(holder_delayed_output_pending.is_none());
1517                                         holder_delayed_output_pending = Some(event.confirmation_threshold());
1518                                 },
1519                                 _ => {},
1520                         }
1521                 }
1522                 let htlc_resolved = self.htlcs_resolved_on_chain.iter()
1523                         .find(|v| if v.commitment_tx_output_idx == Some(htlc_commitment_tx_output_idx) {
1524                                 debug_assert!(htlc_spend_txid_opt.is_none());
1525                                 htlc_spend_txid_opt = v.resolving_txid.as_ref();
1526                                 debug_assert!(htlc_spend_tx_opt.is_none());
1527                                 htlc_spend_tx_opt = v.resolving_tx.as_ref();
1528                                 true
1529                         } else { false });
1530                 debug_assert!(holder_timeout_spend_pending.is_some() as u8 + htlc_spend_pending.is_some() as u8 + htlc_resolved.is_some() as u8 <= 1);
1531
1532                 let htlc_commitment_outpoint = BitcoinOutPoint::new(confirmed_txid.unwrap(), htlc_commitment_tx_output_idx);
1533                 let htlc_output_to_spend =
1534                         if let Some(txid) = htlc_spend_txid_opt {
1535                                 // Because HTLC transactions either only have 1 input and 1 output (pre-anchors) or
1536                                 // are signed with SIGHASH_SINGLE|ANYONECANPAY under BIP-0143 (post-anchors), we can
1537                                 // locate the correct output by ensuring its adjacent input spends the HTLC output
1538                                 // in the commitment.
1539                                 if let Some(ref tx) = htlc_spend_tx_opt {
1540                                         let htlc_input_idx_opt = tx.input.iter().enumerate()
1541                                                 .find(|(_, input)| input.previous_output == htlc_commitment_outpoint)
1542                                                 .map(|(idx, _)| idx as u32);
1543                                         debug_assert!(htlc_input_idx_opt.is_some());
1544                                         BitcoinOutPoint::new(*txid, htlc_input_idx_opt.unwrap_or(0))
1545                                 } else {
1546                                         debug_assert!(!self.onchain_tx_handler.opt_anchors());
1547                                         BitcoinOutPoint::new(*txid, 0)
1548                                 }
1549                         } else {
1550                                 htlc_commitment_outpoint
1551                         };
1552                 let htlc_output_spend_pending = self.onchain_tx_handler.is_output_spend_pending(&htlc_output_to_spend);
1553
1554                 if let Some(conf_thresh) = holder_delayed_output_pending {
1555                         debug_assert!(holder_commitment);
1556                         return Some(Balance::ClaimableAwaitingConfirmations {
1557                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1558                                 confirmation_height: conf_thresh,
1559                         });
1560                 } else if htlc_resolved.is_some() && !htlc_output_spend_pending {
1561                         // Funding transaction spends should be fully confirmed by the time any
1562                         // HTLC transactions are resolved, unless we're talking about a holder
1563                         // commitment tx, whose resolution is delayed until the CSV timeout is
1564                         // reached, even though HTLCs may be resolved after only
1565                         // ANTI_REORG_DELAY confirmations.
1566                         debug_assert!(holder_commitment || self.funding_spend_confirmed.is_some());
1567                 } else if counterparty_revoked_commitment {
1568                         let htlc_output_claim_pending = self.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1569                                 if let OnchainEvent::MaturingOutput {
1570                                         descriptor: SpendableOutputDescriptor::StaticOutput { .. }
1571                                 } = &event.event {
1572                                         if event.transaction.as_ref().map(|tx| tx.input.iter().any(|inp| {
1573                                                 if let Some(htlc_spend_txid) = htlc_spend_txid_opt {
1574                                                         tx.txid() == *htlc_spend_txid || inp.previous_output.txid == *htlc_spend_txid
1575                                                 } else {
1576                                                         Some(inp.previous_output.txid) == confirmed_txid &&
1577                                                                 inp.previous_output.vout == htlc_commitment_tx_output_idx
1578                                                 }
1579                                         })).unwrap_or(false) {
1580                                                 Some(())
1581                                         } else { None }
1582                                 } else { None }
1583                         });
1584                         if htlc_output_claim_pending.is_some() {
1585                                 // We already push `Balance`s onto the `res` list for every
1586                                 // `StaticOutput` in a `MaturingOutput` in the revoked
1587                                 // counterparty commitment transaction case generally, so don't
1588                                 // need to do so again here.
1589                         } else {
1590                                 debug_assert!(holder_timeout_spend_pending.is_none(),
1591                                         "HTLCUpdate OnchainEvents should never appear for preimage claims");
1592                                 debug_assert!(!htlc.offered || htlc_spend_pending.is_none() || !htlc_spend_pending.unwrap().1,
1593                                         "We don't (currently) generate preimage claims against revoked outputs, where did you get one?!");
1594                                 return Some(Balance::CounterpartyRevokedOutputClaimable {
1595                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1596                                 });
1597                         }
1598                 } else if htlc.offered == holder_commitment {
1599                         // If the payment was outbound, check if there's an HTLCUpdate
1600                         // indicating we have spent this HTLC with a timeout, claiming it back
1601                         // and awaiting confirmations on it.
1602                         if let Some(conf_thresh) = holder_timeout_spend_pending {
1603                                 return Some(Balance::ClaimableAwaitingConfirmations {
1604                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1605                                         confirmation_height: conf_thresh,
1606                                 });
1607                         } else {
1608                                 return Some(Balance::MaybeTimeoutClaimableHTLC {
1609                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1610                                         claimable_height: htlc.cltv_expiry,
1611                                 });
1612                         }
1613                 } else if self.payment_preimages.get(&htlc.payment_hash).is_some() {
1614                         // Otherwise (the payment was inbound), only expose it as claimable if
1615                         // we know the preimage.
1616                         // Note that if there is a pending claim, but it did not use the
1617                         // preimage, we lost funds to our counterparty! We will then continue
1618                         // to show it as ContentiousClaimable until ANTI_REORG_DELAY.
1619                         debug_assert!(holder_timeout_spend_pending.is_none());
1620                         if let Some((conf_thresh, true)) = htlc_spend_pending {
1621                                 return Some(Balance::ClaimableAwaitingConfirmations {
1622                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1623                                         confirmation_height: conf_thresh,
1624                                 });
1625                         } else {
1626                                 return Some(Balance::ContentiousClaimable {
1627                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1628                                         timeout_height: htlc.cltv_expiry,
1629                                 });
1630                         }
1631                 } else if htlc_resolved.is_none() {
1632                         return Some(Balance::MaybePreimageClaimableHTLC {
1633                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1634                                 expiry_height: htlc.cltv_expiry,
1635                         });
1636                 }
1637                 None
1638         }
1639 }
1640
1641 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
1642         /// Gets the balances in this channel which are either claimable by us if we were to
1643         /// force-close the channel now or which are claimable on-chain (possibly awaiting
1644         /// confirmation).
1645         ///
1646         /// Any balances in the channel which are available on-chain (excluding on-chain fees) are
1647         /// included here until an [`Event::SpendableOutputs`] event has been generated for the
1648         /// balance, or until our counterparty has claimed the balance and accrued several
1649         /// confirmations on the claim transaction.
1650         ///
1651         /// Note that for `ChannelMonitors` which track a channel which went on-chain with versions of
1652         /// LDK prior to 0.0.111, balances may not be fully captured if our counterparty broadcasted
1653         /// a revoked state.
1654         ///
1655         /// See [`Balance`] for additional details on the types of claimable balances which
1656         /// may be returned here and their meanings.
1657         pub fn get_claimable_balances(&self) -> Vec<Balance> {
1658                 let mut res = Vec::new();
1659                 let us = self.inner.lock().unwrap();
1660
1661                 let mut confirmed_txid = us.funding_spend_confirmed;
1662                 let mut confirmed_counterparty_output = us.confirmed_commitment_tx_counterparty_output;
1663                 let mut pending_commitment_tx_conf_thresh = None;
1664                 let funding_spend_pending = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1665                         if let OnchainEvent::FundingSpendConfirmation { commitment_tx_to_counterparty_output, .. } =
1666                                 event.event
1667                         {
1668                                 confirmed_counterparty_output = commitment_tx_to_counterparty_output;
1669                                 Some((event.txid, event.confirmation_threshold()))
1670                         } else { None }
1671                 });
1672                 if let Some((txid, conf_thresh)) = funding_spend_pending {
1673                         debug_assert!(us.funding_spend_confirmed.is_none(),
1674                                 "We have a pending funding spend awaiting anti-reorg confirmation, we can't have confirmed it already!");
1675                         confirmed_txid = Some(txid);
1676                         pending_commitment_tx_conf_thresh = Some(conf_thresh);
1677                 }
1678
1679                 macro_rules! walk_htlcs {
1680                         ($holder_commitment: expr, $counterparty_revoked_commitment: expr, $htlc_iter: expr) => {
1681                                 for htlc in $htlc_iter {
1682                                         if htlc.transaction_output_index.is_some() {
1683
1684                                                 if let Some(bal) = us.get_htlc_balance(htlc, $holder_commitment, $counterparty_revoked_commitment, confirmed_txid) {
1685                                                         res.push(bal);
1686                                                 }
1687                                         }
1688                                 }
1689                         }
1690                 }
1691
1692                 if let Some(txid) = confirmed_txid {
1693                         let mut found_commitment_tx = false;
1694                         if let Some(counterparty_tx_htlcs) = us.counterparty_claimable_outpoints.get(&txid) {
1695                                 // First look for the to_remote output back to us.
1696                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1697                                         if let Some(value) = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1698                                                 if let OnchainEvent::MaturingOutput {
1699                                                         descriptor: SpendableOutputDescriptor::StaticPaymentOutput(descriptor)
1700                                                 } = &event.event {
1701                                                         Some(descriptor.output.value)
1702                                                 } else { None }
1703                                         }) {
1704                                                 res.push(Balance::ClaimableAwaitingConfirmations {
1705                                                         claimable_amount_satoshis: value,
1706                                                         confirmation_height: conf_thresh,
1707                                                 });
1708                                         } else {
1709                                                 // If a counterparty commitment transaction is awaiting confirmation, we
1710                                                 // should either have a StaticPaymentOutput MaturingOutput event awaiting
1711                                                 // confirmation with the same height or have never met our dust amount.
1712                                         }
1713                                 }
1714                                 if Some(txid) == us.current_counterparty_commitment_txid || Some(txid) == us.prev_counterparty_commitment_txid {
1715                                         walk_htlcs!(false, false, counterparty_tx_htlcs.iter().map(|(a, _)| a));
1716                                 } else {
1717                                         walk_htlcs!(false, true, counterparty_tx_htlcs.iter().map(|(a, _)| a));
1718                                         // The counterparty broadcasted a revoked state!
1719                                         // Look for any StaticOutputs first, generating claimable balances for those.
1720                                         // If any match the confirmed counterparty revoked to_self output, skip
1721                                         // generating a CounterpartyRevokedOutputClaimable.
1722                                         let mut spent_counterparty_output = false;
1723                                         for event in us.onchain_events_awaiting_threshold_conf.iter() {
1724                                                 if let OnchainEvent::MaturingOutput {
1725                                                         descriptor: SpendableOutputDescriptor::StaticOutput { output, .. }
1726                                                 } = &event.event {
1727                                                         res.push(Balance::ClaimableAwaitingConfirmations {
1728                                                                 claimable_amount_satoshis: output.value,
1729                                                                 confirmation_height: event.confirmation_threshold(),
1730                                                         });
1731                                                         if let Some(confirmed_to_self_idx) = confirmed_counterparty_output.map(|(idx, _)| idx) {
1732                                                                 if event.transaction.as_ref().map(|tx|
1733                                                                         tx.input.iter().any(|inp| inp.previous_output.vout == confirmed_to_self_idx)
1734                                                                 ).unwrap_or(false) {
1735                                                                         spent_counterparty_output = true;
1736                                                                 }
1737                                                         }
1738                                                 }
1739                                         }
1740
1741                                         if spent_counterparty_output {
1742                                         } else if let Some((confirmed_to_self_idx, amt)) = confirmed_counterparty_output {
1743                                                 let output_spendable = us.onchain_tx_handler
1744                                                         .is_output_spend_pending(&BitcoinOutPoint::new(txid, confirmed_to_self_idx));
1745                                                 if output_spendable {
1746                                                         res.push(Balance::CounterpartyRevokedOutputClaimable {
1747                                                                 claimable_amount_satoshis: amt,
1748                                                         });
1749                                                 }
1750                                         } else {
1751                                                 // Counterparty output is missing, either it was broadcasted on a
1752                                                 // previous version of LDK or the counterparty hadn't met dust.
1753                                         }
1754                                 }
1755                                 found_commitment_tx = true;
1756                         } else if txid == us.current_holder_commitment_tx.txid {
1757                                 walk_htlcs!(true, false, us.current_holder_commitment_tx.htlc_outputs.iter().map(|(a, _, _)| a));
1758                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1759                                         res.push(Balance::ClaimableAwaitingConfirmations {
1760                                                 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
1761                                                 confirmation_height: conf_thresh,
1762                                         });
1763                                 }
1764                                 found_commitment_tx = true;
1765                         } else if let Some(prev_commitment) = &us.prev_holder_signed_commitment_tx {
1766                                 if txid == prev_commitment.txid {
1767                                         walk_htlcs!(true, false, prev_commitment.htlc_outputs.iter().map(|(a, _, _)| a));
1768                                         if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1769                                                 res.push(Balance::ClaimableAwaitingConfirmations {
1770                                                         claimable_amount_satoshis: prev_commitment.to_self_value_sat,
1771                                                         confirmation_height: conf_thresh,
1772                                                 });
1773                                         }
1774                                         found_commitment_tx = true;
1775                                 }
1776                         }
1777                         if !found_commitment_tx {
1778                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1779                                         // We blindly assume this is a cooperative close transaction here, and that
1780                                         // neither us nor our counterparty misbehaved. At worst we've under-estimated
1781                                         // the amount we can claim as we'll punish a misbehaving counterparty.
1782                                         res.push(Balance::ClaimableAwaitingConfirmations {
1783                                                 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
1784                                                 confirmation_height: conf_thresh,
1785                                         });
1786                                 }
1787                         }
1788                 } else {
1789                         let mut claimable_inbound_htlc_value_sat = 0;
1790                         for (htlc, _, _) in us.current_holder_commitment_tx.htlc_outputs.iter() {
1791                                 if htlc.transaction_output_index.is_none() { continue; }
1792                                 if htlc.offered {
1793                                         res.push(Balance::MaybeTimeoutClaimableHTLC {
1794                                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1795                                                 claimable_height: htlc.cltv_expiry,
1796                                         });
1797                                 } else if us.payment_preimages.get(&htlc.payment_hash).is_some() {
1798                                         claimable_inbound_htlc_value_sat += htlc.amount_msat / 1000;
1799                                 } else {
1800                                         // As long as the HTLC is still in our latest commitment state, treat
1801                                         // it as potentially claimable, even if it has long-since expired.
1802                                         res.push(Balance::MaybePreimageClaimableHTLC {
1803                                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1804                                                 expiry_height: htlc.cltv_expiry,
1805                                         });
1806                                 }
1807                         }
1808                         res.push(Balance::ClaimableOnChannelClose {
1809                                 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat + claimable_inbound_htlc_value_sat,
1810                         });
1811                 }
1812
1813                 res
1814         }
1815
1816         /// Gets the set of outbound HTLCs which can be (or have been) resolved by this
1817         /// `ChannelMonitor`. This is used to determine if an HTLC was removed from the channel prior
1818         /// to the `ChannelManager` having been persisted.
1819         ///
1820         /// This is similar to [`Self::get_pending_or_resolved_outbound_htlcs`] except it includes
1821         /// HTLCs which were resolved on-chain (i.e. where the final HTLC resolution was done by an
1822         /// event from this `ChannelMonitor`).
1823         pub(crate) fn get_all_current_outbound_htlcs(&self) -> HashMap<HTLCSource, (HTLCOutputInCommitment, Option<PaymentPreimage>)> {
1824                 let mut res = HashMap::new();
1825                 // Just examine the available counterparty commitment transactions. See docs on
1826                 // `fail_unbroadcast_htlcs`, below, for justification.
1827                 let us = self.inner.lock().unwrap();
1828                 macro_rules! walk_counterparty_commitment {
1829                         ($txid: expr) => {
1830                                 if let Some(ref latest_outpoints) = us.counterparty_claimable_outpoints.get($txid) {
1831                                         for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1832                                                 if let &Some(ref source) = source_option {
1833                                                         res.insert((**source).clone(), (htlc.clone(),
1834                                                                 us.counterparty_fulfilled_htlcs.get(&SentHTLCId::from_source(source)).cloned()));
1835                                                 }
1836                                         }
1837                                 }
1838                         }
1839                 }
1840                 if let Some(ref txid) = us.current_counterparty_commitment_txid {
1841                         walk_counterparty_commitment!(txid);
1842                 }
1843                 if let Some(ref txid) = us.prev_counterparty_commitment_txid {
1844                         walk_counterparty_commitment!(txid);
1845                 }
1846                 res
1847         }
1848
1849         /// Gets the set of outbound HTLCs which are pending resolution in this channel or which were
1850         /// resolved with a preimage from our counterparty.
1851         ///
1852         /// This is used to reconstruct pending outbound payments on restart in the ChannelManager.
1853         ///
1854         /// Currently, the preimage is unused, however if it is present in the relevant internal state
1855         /// an HTLC is always included even if it has been resolved.
1856         pub(crate) fn get_pending_or_resolved_outbound_htlcs(&self) -> HashMap<HTLCSource, (HTLCOutputInCommitment, Option<PaymentPreimage>)> {
1857                 let us = self.inner.lock().unwrap();
1858                 // We're only concerned with the confirmation count of HTLC transactions, and don't
1859                 // actually care how many confirmations a commitment transaction may or may not have. Thus,
1860                 // we look for either a FundingSpendConfirmation event or a funding_spend_confirmed.
1861                 let confirmed_txid = us.funding_spend_confirmed.or_else(|| {
1862                         us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1863                                 if let OnchainEvent::FundingSpendConfirmation { .. } = event.event {
1864                                         Some(event.txid)
1865                                 } else { None }
1866                         })
1867                 });
1868
1869                 if confirmed_txid.is_none() {
1870                         // If we have not seen a commitment transaction on-chain (ie the channel is not yet
1871                         // closed), just get the full set.
1872                         mem::drop(us);
1873                         return self.get_all_current_outbound_htlcs();
1874                 }
1875
1876                 let mut res = HashMap::new();
1877                 macro_rules! walk_htlcs {
1878                         ($holder_commitment: expr, $htlc_iter: expr) => {
1879                                 for (htlc, source) in $htlc_iter {
1880                                         if us.htlcs_resolved_on_chain.iter().any(|v| v.commitment_tx_output_idx == htlc.transaction_output_index) {
1881                                                 // We should assert that funding_spend_confirmed is_some() here, but we
1882                                                 // have some unit tests which violate HTLC transaction CSVs entirely and
1883                                                 // would fail.
1884                                                 // TODO: Once tests all connect transactions at consensus-valid times, we
1885                                                 // should assert here like we do in `get_claimable_balances`.
1886                                         } else if htlc.offered == $holder_commitment {
1887                                                 // If the payment was outbound, check if there's an HTLCUpdate
1888                                                 // indicating we have spent this HTLC with a timeout, claiming it back
1889                                                 // and awaiting confirmations on it.
1890                                                 let htlc_update_confd = us.onchain_events_awaiting_threshold_conf.iter().any(|event| {
1891                                                         if let OnchainEvent::HTLCUpdate { commitment_tx_output_idx: Some(commitment_tx_output_idx), .. } = event.event {
1892                                                                 // If the HTLC was timed out, we wait for ANTI_REORG_DELAY blocks
1893                                                                 // before considering it "no longer pending" - this matches when we
1894                                                                 // provide the ChannelManager an HTLC failure event.
1895                                                                 Some(commitment_tx_output_idx) == htlc.transaction_output_index &&
1896                                                                         us.best_block.height() >= event.height + ANTI_REORG_DELAY - 1
1897                                                         } else if let OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, .. } = event.event {
1898                                                                 // If the HTLC was fulfilled with a preimage, we consider the HTLC
1899                                                                 // immediately non-pending, matching when we provide ChannelManager
1900                                                                 // the preimage.
1901                                                                 Some(commitment_tx_output_idx) == htlc.transaction_output_index
1902                                                         } else { false }
1903                                                 });
1904                                                 let counterparty_resolved_preimage_opt =
1905                                                         us.counterparty_fulfilled_htlcs.get(&SentHTLCId::from_source(source)).cloned();
1906                                                 if !htlc_update_confd || counterparty_resolved_preimage_opt.is_some() {
1907                                                         res.insert(source.clone(), (htlc.clone(), counterparty_resolved_preimage_opt));
1908                                                 }
1909                                         }
1910                                 }
1911                         }
1912                 }
1913
1914                 let txid = confirmed_txid.unwrap();
1915                 if Some(txid) == us.current_counterparty_commitment_txid || Some(txid) == us.prev_counterparty_commitment_txid {
1916                         walk_htlcs!(false, us.counterparty_claimable_outpoints.get(&txid).unwrap().iter().filter_map(|(a, b)| {
1917                                 if let &Some(ref source) = b {
1918                                         Some((a, &**source))
1919                                 } else { None }
1920                         }));
1921                 } else if txid == us.current_holder_commitment_tx.txid {
1922                         walk_htlcs!(true, us.current_holder_commitment_tx.htlc_outputs.iter().filter_map(|(a, _, c)| {
1923                                 if let Some(source) = c { Some((a, source)) } else { None }
1924                         }));
1925                 } else if let Some(prev_commitment) = &us.prev_holder_signed_commitment_tx {
1926                         if txid == prev_commitment.txid {
1927                                 walk_htlcs!(true, prev_commitment.htlc_outputs.iter().filter_map(|(a, _, c)| {
1928                                         if let Some(source) = c { Some((a, source)) } else { None }
1929                                 }));
1930                         }
1931                 }
1932
1933                 res
1934         }
1935
1936         pub(crate) fn get_stored_preimages(&self) -> HashMap<PaymentHash, PaymentPreimage> {
1937                 self.inner.lock().unwrap().payment_preimages.clone()
1938         }
1939 }
1940
1941 /// Compares a broadcasted commitment transaction's HTLCs with those in the latest state,
1942 /// failing any HTLCs which didn't make it into the broadcasted commitment transaction back
1943 /// after ANTI_REORG_DELAY blocks.
1944 ///
1945 /// We always compare against the set of HTLCs in counterparty commitment transactions, as those
1946 /// are the commitment transactions which are generated by us. The off-chain state machine in
1947 /// `Channel` will automatically resolve any HTLCs which were never included in a commitment
1948 /// transaction when it detects channel closure, but it is up to us to ensure any HTLCs which were
1949 /// included in a remote commitment transaction are failed back if they are not present in the
1950 /// broadcasted commitment transaction.
1951 ///
1952 /// Specifically, the removal process for HTLCs in `Channel` is always based on the counterparty
1953 /// sending a `revoke_and_ack`, which causes us to clear `prev_counterparty_commitment_txid`. Thus,
1954 /// as long as we examine both the current counterparty commitment transaction and, if it hasn't
1955 /// been revoked yet, the previous one, we we will never "forget" to resolve an HTLC.
1956 macro_rules! fail_unbroadcast_htlcs {
1957         ($self: expr, $commitment_tx_type: expr, $commitment_txid_confirmed: expr, $commitment_tx_confirmed: expr,
1958          $commitment_tx_conf_height: expr, $commitment_tx_conf_hash: expr, $confirmed_htlcs_list: expr, $logger: expr) => { {
1959                 debug_assert_eq!($commitment_tx_confirmed.txid(), $commitment_txid_confirmed);
1960
1961                 macro_rules! check_htlc_fails {
1962                         ($txid: expr, $commitment_tx: expr) => {
1963                                 if let Some(ref latest_outpoints) = $self.counterparty_claimable_outpoints.get($txid) {
1964                                         for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1965                                                 if let &Some(ref source) = source_option {
1966                                                         // Check if the HTLC is present in the commitment transaction that was
1967                                                         // broadcast, but not if it was below the dust limit, which we should
1968                                                         // fail backwards immediately as there is no way for us to learn the
1969                                                         // payment_preimage.
1970                                                         // Note that if the dust limit were allowed to change between
1971                                                         // commitment transactions we'd want to be check whether *any*
1972                                                         // broadcastable commitment transaction has the HTLC in it, but it
1973                                                         // cannot currently change after channel initialization, so we don't
1974                                                         // need to here.
1975                                                         let confirmed_htlcs_iter: &mut Iterator<Item = (&HTLCOutputInCommitment, Option<&HTLCSource>)> = &mut $confirmed_htlcs_list;
1976
1977                                                         let mut matched_htlc = false;
1978                                                         for (ref broadcast_htlc, ref broadcast_source) in confirmed_htlcs_iter {
1979                                                                 if broadcast_htlc.transaction_output_index.is_some() &&
1980                                                                         (Some(&**source) == *broadcast_source ||
1981                                                                          (broadcast_source.is_none() &&
1982                                                                           broadcast_htlc.payment_hash == htlc.payment_hash &&
1983                                                                           broadcast_htlc.amount_msat == htlc.amount_msat)) {
1984                                                                         matched_htlc = true;
1985                                                                         break;
1986                                                                 }
1987                                                         }
1988                                                         if matched_htlc { continue; }
1989                                                         if $self.counterparty_fulfilled_htlcs.get(&SentHTLCId::from_source(source)).is_some() {
1990                                                                 continue;
1991                                                         }
1992                                                         $self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
1993                                                                 if entry.height != $commitment_tx_conf_height { return true; }
1994                                                                 match entry.event {
1995                                                                         OnchainEvent::HTLCUpdate { source: ref update_source, .. } => {
1996                                                                                 *update_source != **source
1997                                                                         },
1998                                                                         _ => true,
1999                                                                 }
2000                                                         });
2001                                                         let entry = OnchainEventEntry {
2002                                                                 txid: $commitment_txid_confirmed,
2003                                                                 transaction: Some($commitment_tx_confirmed.clone()),
2004                                                                 height: $commitment_tx_conf_height,
2005                                                                 block_hash: Some(*$commitment_tx_conf_hash),
2006                                                                 event: OnchainEvent::HTLCUpdate {
2007                                                                         source: (**source).clone(),
2008                                                                         payment_hash: htlc.payment_hash.clone(),
2009                                                                         htlc_value_satoshis: Some(htlc.amount_msat / 1000),
2010                                                                         commitment_tx_output_idx: None,
2011                                                                 },
2012                                                         };
2013                                                         log_trace!($logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of {} commitment transaction {}, waiting for confirmation (at height {})",
2014                                                                 log_bytes!(htlc.payment_hash.0), $commitment_tx, $commitment_tx_type,
2015                                                                 $commitment_txid_confirmed, entry.confirmation_threshold());
2016                                                         $self.onchain_events_awaiting_threshold_conf.push(entry);
2017                                                 }
2018                                         }
2019                                 }
2020                         }
2021                 }
2022                 if let Some(ref txid) = $self.current_counterparty_commitment_txid {
2023                         check_htlc_fails!(txid, "current");
2024                 }
2025                 if let Some(ref txid) = $self.prev_counterparty_commitment_txid {
2026                         check_htlc_fails!(txid, "previous");
2027                 }
2028         } }
2029 }
2030
2031 // In the `test_invalid_funding_tx` test, we need a bogus script which matches the HTLC-Accepted
2032 // witness length match (ie is 136 bytes long). We generate one here which we also use in some
2033 // in-line tests later.
2034
2035 #[cfg(test)]
2036 pub fn deliberately_bogus_accepted_htlc_witness_program() -> Vec<u8> {
2037         let mut ret = [opcodes::all::OP_NOP.to_u8(); 136];
2038         ret[131] = opcodes::all::OP_DROP.to_u8();
2039         ret[132] = opcodes::all::OP_DROP.to_u8();
2040         ret[133] = opcodes::all::OP_DROP.to_u8();
2041         ret[134] = opcodes::all::OP_DROP.to_u8();
2042         ret[135] = opcodes::OP_TRUE.to_u8();
2043         Vec::from(&ret[..])
2044 }
2045
2046 #[cfg(test)]
2047 pub fn deliberately_bogus_accepted_htlc_witness() -> Vec<Vec<u8>> {
2048         vec![Vec::new(), Vec::new(), Vec::new(), Vec::new(), deliberately_bogus_accepted_htlc_witness_program().into()].into()
2049 }
2050
2051 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
2052         /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
2053         /// needed by holder commitment transactions HTCLs nor by counterparty ones. Unless we haven't already seen
2054         /// counterparty commitment transaction's secret, they are de facto pruned (we can use revocation key).
2055         fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), &'static str> {
2056                 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
2057                         return Err("Previous secret did not match new one");
2058                 }
2059
2060                 // Prune HTLCs from the previous counterparty commitment tx so we don't generate failure/fulfill
2061                 // events for now-revoked/fulfilled HTLCs.
2062                 if let Some(txid) = self.prev_counterparty_commitment_txid.take() {
2063                         if self.current_counterparty_commitment_txid.unwrap() != txid {
2064                                 let cur_claimables = self.counterparty_claimable_outpoints.get(
2065                                         &self.current_counterparty_commitment_txid.unwrap()).unwrap();
2066                                 for (_, ref source_opt) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
2067                                         if let Some(source) = source_opt {
2068                                                 if !cur_claimables.iter()
2069                                                         .any(|(_, cur_source_opt)| cur_source_opt == source_opt)
2070                                                 {
2071                                                         self.counterparty_fulfilled_htlcs.remove(&SentHTLCId::from_source(source));
2072                                                 }
2073                                         }
2074                                 }
2075                                 for &mut (_, ref mut source_opt) in self.counterparty_claimable_outpoints.get_mut(&txid).unwrap() {
2076                                         *source_opt = None;
2077                                 }
2078                         } else {
2079                                 assert!(cfg!(fuzzing), "Commitment txids are unique outside of fuzzing, where hashes can collide");
2080                         }
2081                 }
2082
2083                 if !self.payment_preimages.is_empty() {
2084                         let cur_holder_signed_commitment_tx = &self.current_holder_commitment_tx;
2085                         let prev_holder_signed_commitment_tx = self.prev_holder_signed_commitment_tx.as_ref();
2086                         let min_idx = self.get_min_seen_secret();
2087                         let counterparty_hash_commitment_number = &mut self.counterparty_hash_commitment_number;
2088
2089                         self.payment_preimages.retain(|&k, _| {
2090                                 for &(ref htlc, _, _) in cur_holder_signed_commitment_tx.htlc_outputs.iter() {
2091                                         if k == htlc.payment_hash {
2092                                                 return true
2093                                         }
2094                                 }
2095                                 if let Some(prev_holder_commitment_tx) = prev_holder_signed_commitment_tx {
2096                                         for &(ref htlc, _, _) in prev_holder_commitment_tx.htlc_outputs.iter() {
2097                                                 if k == htlc.payment_hash {
2098                                                         return true
2099                                                 }
2100                                         }
2101                                 }
2102                                 let contains = if let Some(cn) = counterparty_hash_commitment_number.get(&k) {
2103                                         if *cn < min_idx {
2104                                                 return true
2105                                         }
2106                                         true
2107                                 } else { false };
2108                                 if contains {
2109                                         counterparty_hash_commitment_number.remove(&k);
2110                                 }
2111                                 false
2112                         });
2113                 }
2114
2115                 Ok(())
2116         }
2117
2118         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 {
2119                 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
2120                 // so that a remote monitor doesn't learn anything unless there is a malicious close.
2121                 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
2122                 // timeouts)
2123                 for &(ref htlc, _) in &htlc_outputs {
2124                         self.counterparty_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
2125                 }
2126
2127                 log_trace!(logger, "Tracking new counterparty commitment transaction with txid {} at commitment number {} with {} HTLC outputs", txid, commitment_number, htlc_outputs.len());
2128                 self.prev_counterparty_commitment_txid = self.current_counterparty_commitment_txid.take();
2129                 self.current_counterparty_commitment_txid = Some(txid);
2130                 self.counterparty_claimable_outpoints.insert(txid, htlc_outputs.clone());
2131                 self.current_counterparty_commitment_number = commitment_number;
2132                 //TODO: Merge this into the other per-counterparty-transaction output storage stuff
2133                 match self.their_cur_per_commitment_points {
2134                         Some(old_points) => {
2135                                 if old_points.0 == commitment_number + 1 {
2136                                         self.their_cur_per_commitment_points = Some((old_points.0, old_points.1, Some(their_per_commitment_point)));
2137                                 } else if old_points.0 == commitment_number + 2 {
2138                                         if let Some(old_second_point) = old_points.2 {
2139                                                 self.their_cur_per_commitment_points = Some((old_points.0 - 1, old_second_point, Some(their_per_commitment_point)));
2140                                         } else {
2141                                                 self.their_cur_per_commitment_points = Some((commitment_number, their_per_commitment_point, None));
2142                                         }
2143                                 } else {
2144                                         self.their_cur_per_commitment_points = Some((commitment_number, their_per_commitment_point, None));
2145                                 }
2146                         },
2147                         None => {
2148                                 self.their_cur_per_commitment_points = Some((commitment_number, their_per_commitment_point, None));
2149                         }
2150                 }
2151                 let mut htlcs = Vec::with_capacity(htlc_outputs.len());
2152                 for htlc in htlc_outputs {
2153                         if htlc.0.transaction_output_index.is_some() {
2154                                 htlcs.push(htlc.0);
2155                         }
2156                 }
2157         }
2158
2159         /// Informs this monitor of the latest holder (ie broadcastable) commitment transaction. The
2160         /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
2161         /// is important that any clones of this channel monitor (including remote clones) by kept
2162         /// up-to-date as our holder commitment transaction is updated.
2163         /// Panics if set_on_holder_tx_csv has never been called.
2164         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> {
2165                 let trusted_tx = holder_commitment_tx.trust();
2166                 let txid = trusted_tx.txid();
2167                 let tx_keys = trusted_tx.keys();
2168                 self.current_holder_commitment_number = trusted_tx.commitment_number();
2169                 let mut new_holder_commitment_tx = HolderSignedTx {
2170                         txid,
2171                         revocation_key: tx_keys.revocation_key,
2172                         a_htlc_key: tx_keys.broadcaster_htlc_key,
2173                         b_htlc_key: tx_keys.countersignatory_htlc_key,
2174                         delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
2175                         per_commitment_point: tx_keys.per_commitment_point,
2176                         htlc_outputs,
2177                         to_self_value_sat: holder_commitment_tx.to_broadcaster_value_sat(),
2178                         feerate_per_kw: trusted_tx.feerate_per_kw(),
2179                 };
2180                 self.onchain_tx_handler.provide_latest_holder_tx(holder_commitment_tx);
2181                 mem::swap(&mut new_holder_commitment_tx, &mut self.current_holder_commitment_tx);
2182                 self.prev_holder_signed_commitment_tx = Some(new_holder_commitment_tx);
2183                 for (claimed_htlc_id, claimed_preimage) in claimed_htlcs {
2184                         #[cfg(debug_assertions)] {
2185                                 let cur_counterparty_htlcs = self.counterparty_claimable_outpoints.get(
2186                                                 &self.current_counterparty_commitment_txid.unwrap()).unwrap();
2187                                 assert!(cur_counterparty_htlcs.iter().any(|(_, source_opt)| {
2188                                         if let Some(source) = source_opt {
2189                                                 SentHTLCId::from_source(source) == *claimed_htlc_id
2190                                         } else { false }
2191                                 }));
2192                         }
2193                         self.counterparty_fulfilled_htlcs.insert(*claimed_htlc_id, *claimed_preimage);
2194                 }
2195                 if self.holder_tx_signed {
2196                         return Err("Latest holder commitment signed has already been signed, update is rejected");
2197                 }
2198                 Ok(())
2199         }
2200
2201         /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
2202         /// commitment_tx_infos which contain the payment hash have been revoked.
2203         fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(
2204                 &mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage, broadcaster: &B,
2205                 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L)
2206         where B::Target: BroadcasterInterface,
2207                     F::Target: FeeEstimator,
2208                     L::Target: Logger,
2209         {
2210                 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
2211
2212                 // If the channel is force closed, try to claim the output from this preimage.
2213                 // First check if a counterparty commitment transaction has been broadcasted:
2214                 macro_rules! claim_htlcs {
2215                         ($commitment_number: expr, $txid: expr) => {
2216                                 let (htlc_claim_reqs, _) = self.get_counterparty_output_claim_info($commitment_number, $txid, None);
2217                                 self.onchain_tx_handler.update_claims_view_from_requests(htlc_claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
2218                         }
2219                 }
2220                 if let Some(txid) = self.current_counterparty_commitment_txid {
2221                         if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
2222                                 claim_htlcs!(*commitment_number, txid);
2223                                 return;
2224                         }
2225                 }
2226                 if let Some(txid) = self.prev_counterparty_commitment_txid {
2227                         if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
2228                                 claim_htlcs!(*commitment_number, txid);
2229                                 return;
2230                         }
2231                 }
2232
2233                 // Then if a holder commitment transaction has been seen on-chain, broadcast transactions
2234                 // claiming the HTLC output from each of the holder commitment transactions.
2235                 // Note that we can't just use `self.holder_tx_signed`, because that only covers the case where
2236                 // *we* sign a holder commitment transaction, not when e.g. a watchtower broadcasts one of our
2237                 // holder commitment transactions.
2238                 if self.broadcasted_holder_revokable_script.is_some() {
2239                         // Assume that the broadcasted commitment transaction confirmed in the current best
2240                         // block. Even if not, its a reasonable metric for the bump criteria on the HTLC
2241                         // transactions.
2242                         let (claim_reqs, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
2243                         self.onchain_tx_handler.update_claims_view_from_requests(claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
2244                         if let Some(ref tx) = self.prev_holder_signed_commitment_tx {
2245                                 let (claim_reqs, _) = self.get_broadcasted_holder_claims(&tx, self.best_block.height());
2246                                 self.onchain_tx_handler.update_claims_view_from_requests(claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
2247                         }
2248                 }
2249         }
2250
2251         pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
2252                 where B::Target: BroadcasterInterface,
2253                                         L::Target: Logger,
2254         {
2255                 for tx in self.get_latest_holder_commitment_txn(logger).iter() {
2256                         log_info!(logger, "Broadcasting local {}", log_tx!(tx));
2257                         broadcaster.broadcast_transaction(tx);
2258                 }
2259                 self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
2260         }
2261
2262         pub fn update_monitor<B: Deref, F: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: F, logger: &L) -> Result<(), ()>
2263         where B::Target: BroadcasterInterface,
2264                 F::Target: FeeEstimator,
2265                 L::Target: Logger,
2266         {
2267                 log_info!(logger, "Applying update to monitor {}, bringing update_id from {} to {} with {} changes.",
2268                         log_funding_info!(self), self.latest_update_id, updates.update_id, updates.updates.len());
2269                 // ChannelMonitor updates may be applied after force close if we receive a preimage for a
2270                 // broadcasted commitment transaction HTLC output that we'd like to claim on-chain. If this
2271                 // is the case, we no longer have guaranteed access to the monitor's update ID, so we use a
2272                 // sentinel value instead.
2273                 //
2274                 // The `ChannelManager` may also queue redundant `ChannelForceClosed` updates if it still
2275                 // thinks the channel needs to have its commitment transaction broadcast, so we'll allow
2276                 // them as well.
2277                 if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
2278                         assert_eq!(updates.updates.len(), 1);
2279                         match updates.updates[0] {
2280                                 ChannelMonitorUpdateStep::ChannelForceClosed { .. } => {},
2281                                 // We should have already seen a `ChannelForceClosed` update if we're trying to
2282                                 // provide a preimage at this point.
2283                                 ChannelMonitorUpdateStep::PaymentPreimage { .. } =>
2284                                         debug_assert_eq!(self.latest_update_id, CLOSED_CHANNEL_UPDATE_ID),
2285                                 _ => {
2286                                         log_error!(logger, "Attempted to apply post-force-close ChannelMonitorUpdate of type {}", updates.updates[0].variant_name());
2287                                         panic!("Attempted to apply post-force-close ChannelMonitorUpdate that wasn't providing a payment preimage");
2288                                 },
2289                         }
2290                 } else if self.latest_update_id + 1 != updates.update_id {
2291                         panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
2292                 }
2293                 let mut ret = Ok(());
2294                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&*fee_estimator);
2295                 for update in updates.updates.iter() {
2296                         match update {
2297                                 ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs, claimed_htlcs } => {
2298                                         log_trace!(logger, "Updating ChannelMonitor with latest holder commitment transaction info");
2299                                         if self.lockdown_from_offchain { panic!(); }
2300                                         if let Err(e) = self.provide_latest_holder_commitment_tx(commitment_tx.clone(), htlc_outputs.clone(), &claimed_htlcs) {
2301                                                 log_error!(logger, "Providing latest holder commitment transaction failed/was refused:");
2302                                                 log_error!(logger, "    {}", e);
2303                                                 ret = Err(());
2304                                         }
2305                                 }
2306                                 ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid, htlc_outputs, commitment_number, their_per_commitment_point } => {
2307                                         log_trace!(logger, "Updating ChannelMonitor with latest counterparty commitment transaction info");
2308                                         self.provide_latest_counterparty_commitment_tx(*commitment_txid, htlc_outputs.clone(), *commitment_number, *their_per_commitment_point, logger)
2309                                 },
2310                                 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } => {
2311                                         log_trace!(logger, "Updating ChannelMonitor with payment preimage");
2312                                         self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage, broadcaster, &bounded_fee_estimator, logger)
2313                                 },
2314                                 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } => {
2315                                         log_trace!(logger, "Updating ChannelMonitor with commitment secret");
2316                                         if let Err(e) = self.provide_secret(*idx, *secret) {
2317                                                 log_error!(logger, "Providing latest counterparty commitment secret failed/was refused:");
2318                                                 log_error!(logger, "    {}", e);
2319                                                 ret = Err(());
2320                                         }
2321                                 },
2322                                 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
2323                                         log_trace!(logger, "Updating ChannelMonitor: channel force closed, should broadcast: {}", should_broadcast);
2324                                         self.lockdown_from_offchain = true;
2325                                         if *should_broadcast {
2326                                                 // There's no need to broadcast our commitment transaction if we've seen one
2327                                                 // confirmed (even with 1 confirmation) as it'll be rejected as
2328                                                 // duplicate/conflicting.
2329                                                 let detected_funding_spend = self.funding_spend_confirmed.is_some() ||
2330                                                         self.onchain_events_awaiting_threshold_conf.iter().find(|event| match event.event {
2331                                                                 OnchainEvent::FundingSpendConfirmation { .. } => true,
2332                                                                 _ => false,
2333                                                         }).is_some();
2334                                                 if detected_funding_spend {
2335                                                         continue;
2336                                                 }
2337                                                 self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
2338                                                 // If the channel supports anchor outputs, we'll need to emit an external
2339                                                 // event to be consumed such that a child transaction is broadcast with a
2340                                                 // high enough feerate for the parent commitment transaction to confirm.
2341                                                 if self.onchain_tx_handler.opt_anchors() {
2342                                                         let funding_output = HolderFundingOutput::build(
2343                                                                 self.funding_redeemscript.clone(), self.channel_value_satoshis,
2344                                                                 self.onchain_tx_handler.opt_anchors(),
2345                                                         );
2346                                                         let best_block_height = self.best_block.height();
2347                                                         let commitment_package = PackageTemplate::build_package(
2348                                                                 self.funding_info.0.txid.clone(), self.funding_info.0.index as u32,
2349                                                                 PackageSolvingData::HolderFundingOutput(funding_output),
2350                                                                 best_block_height, false, best_block_height,
2351                                                         );
2352                                                         self.onchain_tx_handler.update_claims_view_from_requests(
2353                                                                 vec![commitment_package], best_block_height, best_block_height,
2354                                                                 broadcaster, &bounded_fee_estimator, logger,
2355                                                         );
2356                                                 }
2357                                         } else if !self.holder_tx_signed {
2358                                                 log_error!(logger, "WARNING: You have a potentially-unsafe holder commitment transaction available to broadcast");
2359                                                 log_error!(logger, "    in channel monitor for channel {}!", log_bytes!(self.funding_info.0.to_channel_id()));
2360                                                 log_error!(logger, "    Read the docs for ChannelMonitor::get_latest_holder_commitment_txn and take manual action!");
2361                                         } else {
2362                                                 // If we generated a MonitorEvent::CommitmentTxConfirmed, the ChannelManager
2363                                                 // will still give us a ChannelForceClosed event with !should_broadcast, but we
2364                                                 // shouldn't print the scary warning above.
2365                                                 log_info!(logger, "Channel off-chain state closed after we broadcasted our latest commitment transaction.");
2366                                         }
2367                                 },
2368                                 ChannelMonitorUpdateStep::ShutdownScript { scriptpubkey } => {
2369                                         log_trace!(logger, "Updating ChannelMonitor with shutdown script");
2370                                         if let Some(shutdown_script) = self.shutdown_script.replace(scriptpubkey.clone()) {
2371                                                 panic!("Attempted to replace shutdown script {} with {}", shutdown_script, scriptpubkey);
2372                                         }
2373                                 },
2374                         }
2375                 }
2376
2377                 // If the updates succeeded and we were in an already closed channel state, then there's no
2378                 // need to refuse any updates we expect to receive afer seeing a confirmed commitment.
2379                 if ret.is_ok() && updates.update_id == CLOSED_CHANNEL_UPDATE_ID && self.latest_update_id == updates.update_id {
2380                         return Ok(());
2381                 }
2382
2383                 self.latest_update_id = updates.update_id;
2384
2385                 if ret.is_ok() && self.funding_spend_seen {
2386                         log_error!(logger, "Refusing Channel Monitor Update as counterparty attempted to update commitment after funding was spent");
2387                         Err(())
2388                 } else { ret }
2389         }
2390
2391         pub fn get_latest_update_id(&self) -> u64 {
2392                 self.latest_update_id
2393         }
2394
2395         pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
2396                 &self.funding_info
2397         }
2398
2399         pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<(u32, Script)>> {
2400                 // If we've detected a counterparty commitment tx on chain, we must include it in the set
2401                 // of outputs to watch for spends of, otherwise we're likely to lose user funds. Because
2402                 // its trivial to do, double-check that here.
2403                 for (txid, _) in self.counterparty_commitment_txn_on_chain.iter() {
2404                         self.outputs_to_watch.get(txid).expect("Counterparty commitment txn which have been broadcast should have outputs registered");
2405                 }
2406                 &self.outputs_to_watch
2407         }
2408
2409         pub fn get_and_clear_pending_monitor_events(&mut self) -> Vec<MonitorEvent> {
2410                 let mut ret = Vec::new();
2411                 mem::swap(&mut ret, &mut self.pending_monitor_events);
2412                 ret
2413         }
2414
2415         pub fn get_and_clear_pending_events(&mut self) -> Vec<Event> {
2416                 let mut ret = Vec::new();
2417                 mem::swap(&mut ret, &mut self.pending_events);
2418                 #[cfg(anchors)]
2419                 for claim_event in self.onchain_tx_handler.get_and_clear_pending_claim_events().drain(..) {
2420                         match claim_event {
2421                                 ClaimEvent::BumpCommitment {
2422                                         package_target_feerate_sat_per_1000_weight, commitment_tx, anchor_output_idx,
2423                                 } => {
2424                                         let commitment_txid = commitment_tx.txid();
2425                                         debug_assert_eq!(self.current_holder_commitment_tx.txid, commitment_txid);
2426                                         let pending_htlcs = self.current_holder_commitment_tx.non_dust_htlcs();
2427                                         let commitment_tx_fee_satoshis = self.channel_value_satoshis -
2428                                                 commitment_tx.output.iter().fold(0u64, |sum, output| sum + output.value);
2429                                         ret.push(Event::BumpTransaction(BumpTransactionEvent::ChannelClose {
2430                                                 package_target_feerate_sat_per_1000_weight,
2431                                                 commitment_tx,
2432                                                 commitment_tx_fee_satoshis,
2433                                                 anchor_descriptor: AnchorDescriptor {
2434                                                         channel_keys_id: self.channel_keys_id,
2435                                                         channel_value_satoshis: self.channel_value_satoshis,
2436                                                         outpoint: BitcoinOutPoint {
2437                                                                 txid: commitment_txid,
2438                                                                 vout: anchor_output_idx,
2439                                                         },
2440                                                 },
2441                                                 pending_htlcs,
2442                                         }));
2443                                 },
2444                                 ClaimEvent::BumpHTLC {
2445                                         target_feerate_sat_per_1000_weight, htlcs,
2446                                 } => {
2447                                         let mut htlc_descriptors = Vec::with_capacity(htlcs.len());
2448                                         for htlc in htlcs {
2449                                                 htlc_descriptors.push(HTLCDescriptor {
2450                                                         channel_keys_id: self.channel_keys_id,
2451                                                         channel_value_satoshis: self.channel_value_satoshis,
2452                                                         channel_parameters: self.onchain_tx_handler.channel_transaction_parameters.clone(),
2453                                                         commitment_txid: htlc.commitment_txid,
2454                                                         per_commitment_number: htlc.per_commitment_number,
2455                                                         htlc: htlc.htlc,
2456                                                         preimage: htlc.preimage,
2457                                                         counterparty_sig: htlc.counterparty_sig,
2458                                                 });
2459                                         }
2460                                         ret.push(Event::BumpTransaction(BumpTransactionEvent::HTLCResolution {
2461                                                 target_feerate_sat_per_1000_weight,
2462                                                 htlc_descriptors,
2463                                         }));
2464                                 }
2465                         }
2466                 }
2467                 ret
2468         }
2469
2470         /// Can only fail if idx is < get_min_seen_secret
2471         fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
2472                 self.commitment_secrets.get_secret(idx)
2473         }
2474
2475         pub(crate) fn get_min_seen_secret(&self) -> u64 {
2476                 self.commitment_secrets.get_min_seen_secret()
2477         }
2478
2479         pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
2480                 self.current_counterparty_commitment_number
2481         }
2482
2483         pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
2484                 self.current_holder_commitment_number
2485         }
2486
2487         /// Attempts to claim a counterparty commitment transaction's outputs using the revocation key and
2488         /// data in counterparty_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
2489         /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
2490         /// HTLC-Success/HTLC-Timeout transactions.
2491         ///
2492         /// Returns packages to claim the revoked output(s), as well as additional outputs to watch and
2493         /// general information about the output that is to the counterparty in the commitment
2494         /// transaction.
2495         fn check_spend_counterparty_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, block_hash: &BlockHash, logger: &L)
2496                 -> (Vec<PackageTemplate>, TransactionOutputs, CommitmentTxCounterpartyOutputInfo)
2497         where L::Target: Logger {
2498                 // Most secp and related errors trying to create keys means we have no hope of constructing
2499                 // a spend transaction...so we return no transactions to broadcast
2500                 let mut claimable_outpoints = Vec::new();
2501                 let mut watch_outputs = Vec::new();
2502                 let mut to_counterparty_output_info = None;
2503
2504                 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
2505                 let per_commitment_option = self.counterparty_claimable_outpoints.get(&commitment_txid);
2506
2507                 macro_rules! ignore_error {
2508                         ( $thing : expr ) => {
2509                                 match $thing {
2510                                         Ok(a) => a,
2511                                         Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs), to_counterparty_output_info)
2512                                 }
2513                         };
2514                 }
2515
2516                 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);
2517                 if commitment_number >= self.get_min_seen_secret() {
2518                         let secret = self.get_secret(commitment_number).unwrap();
2519                         let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
2520                         let per_commitment_point = PublicKey::from_secret_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_key);
2521                         let revocation_pubkey = chan_utils::derive_public_revocation_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint);
2522                         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);
2523
2524                         let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.counterparty_commitment_params.on_counterparty_tx_csv, &delayed_key);
2525                         let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
2526
2527                         // First, process non-htlc outputs (to_holder & to_counterparty)
2528                         for (idx, outp) in tx.output.iter().enumerate() {
2529                                 if outp.script_pubkey == revokeable_p2wsh {
2530                                         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);
2531                                         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);
2532                                         claimable_outpoints.push(justice_package);
2533                                         to_counterparty_output_info =
2534                                                 Some((idx.try_into().expect("Txn can't have more than 2^32 outputs"), outp.value));
2535                                 }
2536                         }
2537
2538                         // Then, try to find revoked htlc outputs
2539                         if let Some(ref per_commitment_data) = per_commitment_option {
2540                                 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
2541                                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2542                                                 if transaction_output_index as usize >= tx.output.len() ||
2543                                                                 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
2544                                                         // per_commitment_data is corrupt or our commitment signing key leaked!
2545                                                         return (claimable_outpoints, (commitment_txid, watch_outputs),
2546                                                                 to_counterparty_output_info);
2547                                                 }
2548                                                 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());
2549                                                 let justice_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, PackageSolvingData::RevokedHTLCOutput(revk_htlc_outp), htlc.cltv_expiry, true, height);
2550                                                 claimable_outpoints.push(justice_package);
2551                                         }
2552                                 }
2553                         }
2554
2555                         // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
2556                         if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
2557                                 // We're definitely a counterparty commitment transaction!
2558                                 log_error!(logger, "Got broadcast of revoked counterparty commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
2559                                 for (idx, outp) in tx.output.iter().enumerate() {
2560                                         watch_outputs.push((idx as u32, outp.clone()));
2561                                 }
2562                                 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
2563
2564                                 if let Some(per_commitment_data) = per_commitment_option {
2565                                         fail_unbroadcast_htlcs!(self, "revoked_counterparty", commitment_txid, tx, height,
2566                                                 block_hash, per_commitment_data.iter().map(|(htlc, htlc_source)|
2567                                                         (htlc, htlc_source.as_ref().map(|htlc_source| htlc_source.as_ref()))
2568                                                 ), logger);
2569                                 } else {
2570                                         debug_assert!(false, "We should have per-commitment option for any recognized old commitment txn");
2571                                         fail_unbroadcast_htlcs!(self, "revoked counterparty", commitment_txid, tx, height,
2572                                                 block_hash, [].iter().map(|reference| *reference), logger);
2573                                 }
2574                         }
2575                 } else if let Some(per_commitment_data) = per_commitment_option {
2576                         // While this isn't useful yet, there is a potential race where if a counterparty
2577                         // revokes a state at the same time as the commitment transaction for that state is
2578                         // confirmed, and the watchtower receives the block before the user, the user could
2579                         // upload a new ChannelMonitor with the revocation secret but the watchtower has
2580                         // already processed the block, resulting in the counterparty_commitment_txn_on_chain entry
2581                         // not being generated by the above conditional. Thus, to be safe, we go ahead and
2582                         // insert it here.
2583                         for (idx, outp) in tx.output.iter().enumerate() {
2584                                 watch_outputs.push((idx as u32, outp.clone()));
2585                         }
2586                         self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
2587
2588                         log_info!(logger, "Got broadcast of non-revoked counterparty commitment transaction {}", commitment_txid);
2589                         fail_unbroadcast_htlcs!(self, "counterparty", commitment_txid, tx, height, block_hash,
2590                                 per_commitment_data.iter().map(|(htlc, htlc_source)|
2591                                         (htlc, htlc_source.as_ref().map(|htlc_source| htlc_source.as_ref()))
2592                                 ), logger);
2593
2594                         let (htlc_claim_reqs, counterparty_output_info) =
2595                                 self.get_counterparty_output_claim_info(commitment_number, commitment_txid, Some(tx));
2596                         to_counterparty_output_info = counterparty_output_info;
2597                         for req in htlc_claim_reqs {
2598                                 claimable_outpoints.push(req);
2599                         }
2600
2601                 }
2602                 (claimable_outpoints, (commitment_txid, watch_outputs), to_counterparty_output_info)
2603         }
2604
2605         /// Returns the HTLC claim package templates and the counterparty output info
2606         fn get_counterparty_output_claim_info(&self, commitment_number: u64, commitment_txid: Txid, tx: Option<&Transaction>)
2607         -> (Vec<PackageTemplate>, CommitmentTxCounterpartyOutputInfo) {
2608                 let mut claimable_outpoints = Vec::new();
2609                 let mut to_counterparty_output_info: CommitmentTxCounterpartyOutputInfo = None;
2610
2611                 let htlc_outputs = match self.counterparty_claimable_outpoints.get(&commitment_txid) {
2612                         Some(outputs) => outputs,
2613                         None => return (claimable_outpoints, to_counterparty_output_info),
2614                 };
2615                 let per_commitment_points = match self.their_cur_per_commitment_points {
2616                         Some(points) => points,
2617                         None => return (claimable_outpoints, to_counterparty_output_info),
2618                 };
2619
2620                 let per_commitment_point =
2621                         // If the counterparty commitment tx is the latest valid state, use their latest
2622                         // per-commitment point
2623                         if per_commitment_points.0 == commitment_number { &per_commitment_points.1 }
2624                         else if let Some(point) = per_commitment_points.2.as_ref() {
2625                                 // If counterparty commitment tx is the state previous to the latest valid state, use
2626                                 // their previous per-commitment point (non-atomicity of revocation means it's valid for
2627                                 // them to temporarily have two valid commitment txns from our viewpoint)
2628                                 if per_commitment_points.0 == commitment_number + 1 {
2629                                         point
2630                                 } else { return (claimable_outpoints, to_counterparty_output_info); }
2631                         } else { return (claimable_outpoints, to_counterparty_output_info); };
2632
2633                 if let Some(transaction) = tx {
2634                         let revocation_pubkey = chan_utils::derive_public_revocation_key(
2635                                 &self.onchain_tx_handler.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint);
2636                         let delayed_key = chan_utils::derive_public_key(&self.onchain_tx_handler.secp_ctx,
2637                                 &per_commitment_point,
2638                                 &self.counterparty_commitment_params.counterparty_delayed_payment_base_key);
2639                         let revokeable_p2wsh = chan_utils::get_revokeable_redeemscript(&revocation_pubkey,
2640                                 self.counterparty_commitment_params.on_counterparty_tx_csv,
2641                                 &delayed_key).to_v0_p2wsh();
2642                         for (idx, outp) in transaction.output.iter().enumerate() {
2643                                 if outp.script_pubkey == revokeable_p2wsh {
2644                                         to_counterparty_output_info =
2645                                                 Some((idx.try_into().expect("Can't have > 2^32 outputs"), outp.value));
2646                                 }
2647                         }
2648                 }
2649
2650                 for (_, &(ref htlc, _)) in htlc_outputs.iter().enumerate() {
2651                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2652                                 if let Some(transaction) = tx {
2653                                         if transaction_output_index as usize >= transaction.output.len() ||
2654                                                 transaction.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
2655                                                         // per_commitment_data is corrupt or our commitment signing key leaked!
2656                                                         return (claimable_outpoints, to_counterparty_output_info);
2657                                                 }
2658                                 }
2659                                 let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
2660                                 if preimage.is_some() || !htlc.offered {
2661                                         let counterparty_htlc_outp = if htlc.offered {
2662                                                 PackageSolvingData::CounterpartyOfferedHTLCOutput(
2663                                                         CounterpartyOfferedHTLCOutput::build(*per_commitment_point,
2664                                                                 self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
2665                                                                 self.counterparty_commitment_params.counterparty_htlc_base_key,
2666                                                                 preimage.unwrap(), htlc.clone(), self.onchain_tx_handler.opt_anchors()))
2667                                         } else {
2668                                                 PackageSolvingData::CounterpartyReceivedHTLCOutput(
2669                                                         CounterpartyReceivedHTLCOutput::build(*per_commitment_point,
2670                                                                 self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
2671                                                                 self.counterparty_commitment_params.counterparty_htlc_base_key,
2672                                                                 htlc.clone(), self.onchain_tx_handler.opt_anchors()))
2673                                         };
2674                                         let aggregation = if !htlc.offered { false } else { true };
2675                                         let counterparty_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, counterparty_htlc_outp, htlc.cltv_expiry,aggregation, 0);
2676                                         claimable_outpoints.push(counterparty_package);
2677                                 }
2678                         }
2679                 }
2680
2681                 (claimable_outpoints, to_counterparty_output_info)
2682         }
2683
2684         /// Attempts to claim a counterparty HTLC-Success/HTLC-Timeout's outputs using the revocation key
2685         fn check_spend_counterparty_htlc<L: Deref>(
2686                 &mut self, tx: &Transaction, commitment_number: u64, commitment_txid: &Txid, height: u32, logger: &L
2687         ) -> (Vec<PackageTemplate>, Option<TransactionOutputs>) where L::Target: Logger {
2688                 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
2689                 let per_commitment_key = match SecretKey::from_slice(&secret) {
2690                         Ok(key) => key,
2691                         Err(_) => return (Vec::new(), None)
2692                 };
2693                 let per_commitment_point = PublicKey::from_secret_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_key);
2694
2695                 let htlc_txid = tx.txid();
2696                 let mut claimable_outpoints = vec![];
2697                 let mut outputs_to_watch = None;
2698                 // Previously, we would only claim HTLCs from revoked HTLC transactions if they had 1 input
2699                 // with a witness of 5 elements and 1 output. This wasn't enough for anchor outputs, as the
2700                 // counterparty can now aggregate multiple HTLCs into a single transaction thanks to
2701                 // `SIGHASH_SINGLE` remote signatures, leading us to not claim any HTLCs upon seeing a
2702                 // confirmed revoked HTLC transaction (for more details, see
2703                 // https://lists.linuxfoundation.org/pipermail/lightning-dev/2022-April/003561.html).
2704                 //
2705                 // We make sure we're not vulnerable to this case by checking all inputs of the transaction,
2706                 // and claim those which spend the commitment transaction, have a witness of 5 elements, and
2707                 // have a corresponding output at the same index within the transaction.
2708                 for (idx, input) in tx.input.iter().enumerate() {
2709                         if input.previous_output.txid == *commitment_txid && input.witness.len() == 5 && tx.output.get(idx).is_some() {
2710                                 log_error!(logger, "Got broadcast of revoked counterparty HTLC transaction, spending {}:{}", htlc_txid, idx);
2711                                 let revk_outp = RevokedOutput::build(
2712                                         per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
2713                                         self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key,
2714                                         tx.output[idx].value, self.counterparty_commitment_params.on_counterparty_tx_csv
2715                                 );
2716                                 let justice_package = PackageTemplate::build_package(
2717                                         htlc_txid, idx as u32, PackageSolvingData::RevokedOutput(revk_outp),
2718                                         height + self.counterparty_commitment_params.on_counterparty_tx_csv as u32, true, height
2719                                 );
2720                                 claimable_outpoints.push(justice_package);
2721                                 if outputs_to_watch.is_none() {
2722                                         outputs_to_watch = Some((htlc_txid, vec![]));
2723                                 }
2724                                 outputs_to_watch.as_mut().unwrap().1.push((idx as u32, tx.output[idx].clone()));
2725                         }
2726                 }
2727                 (claimable_outpoints, outputs_to_watch)
2728         }
2729
2730         // Returns (1) `PackageTemplate`s that can be given to the OnchainTxHandler, so that the handler can
2731         // broadcast transactions claiming holder HTLC commitment outputs and (2) a holder revokable
2732         // script so we can detect whether a holder transaction has been seen on-chain.
2733         fn get_broadcasted_holder_claims(&self, holder_tx: &HolderSignedTx, conf_height: u32) -> (Vec<PackageTemplate>, Option<(Script, PublicKey, PublicKey)>) {
2734                 let mut claim_requests = Vec::with_capacity(holder_tx.htlc_outputs.len());
2735
2736                 let redeemscript = chan_utils::get_revokeable_redeemscript(&holder_tx.revocation_key, self.on_holder_tx_csv, &holder_tx.delayed_payment_key);
2737                 let broadcasted_holder_revokable_script = Some((redeemscript.to_v0_p2wsh(), holder_tx.per_commitment_point.clone(), holder_tx.revocation_key.clone()));
2738
2739                 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
2740                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2741                                 let (htlc_output, aggregable) = if htlc.offered {
2742                                         let htlc_output = HolderHTLCOutput::build_offered(
2743                                                 htlc.amount_msat, htlc.cltv_expiry, self.onchain_tx_handler.opt_anchors()
2744                                         );
2745                                         (htlc_output, false)
2746                                 } else {
2747                                         let payment_preimage = if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
2748                                                 preimage.clone()
2749                                         } else {
2750                                                 // We can't build an HTLC-Success transaction without the preimage
2751                                                 continue;
2752                                         };
2753                                         let htlc_output = HolderHTLCOutput::build_accepted(
2754                                                 payment_preimage, htlc.amount_msat, self.onchain_tx_handler.opt_anchors()
2755                                         );
2756                                         (htlc_output, self.onchain_tx_handler.opt_anchors())
2757                                 };
2758                                 let htlc_package = PackageTemplate::build_package(
2759                                         holder_tx.txid, transaction_output_index,
2760                                         PackageSolvingData::HolderHTLCOutput(htlc_output),
2761                                         htlc.cltv_expiry, aggregable, conf_height
2762                                 );
2763                                 claim_requests.push(htlc_package);
2764                         }
2765                 }
2766
2767                 (claim_requests, broadcasted_holder_revokable_script)
2768         }
2769
2770         // Returns holder HTLC outputs to watch and react to in case of spending.
2771         fn get_broadcasted_holder_watch_outputs(&self, holder_tx: &HolderSignedTx, commitment_tx: &Transaction) -> Vec<(u32, TxOut)> {
2772                 let mut watch_outputs = Vec::with_capacity(holder_tx.htlc_outputs.len());
2773                 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
2774                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2775                                 watch_outputs.push((transaction_output_index, commitment_tx.output[transaction_output_index as usize].clone()));
2776                         }
2777                 }
2778                 watch_outputs
2779         }
2780
2781         /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
2782         /// revoked using data in holder_claimable_outpoints.
2783         /// Should not be used if check_spend_revoked_transaction succeeds.
2784         /// Returns None unless the transaction is definitely one of our commitment transactions.
2785         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 {
2786                 let commitment_txid = tx.txid();
2787                 let mut claim_requests = Vec::new();
2788                 let mut watch_outputs = Vec::new();
2789
2790                 macro_rules! append_onchain_update {
2791                         ($updates: expr, $to_watch: expr) => {
2792                                 claim_requests = $updates.0;
2793                                 self.broadcasted_holder_revokable_script = $updates.1;
2794                                 watch_outputs.append(&mut $to_watch);
2795                         }
2796                 }
2797
2798                 // HTLCs set may differ between last and previous holder commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
2799                 let mut is_holder_tx = false;
2800
2801                 if self.current_holder_commitment_tx.txid == commitment_txid {
2802                         is_holder_tx = true;
2803                         log_info!(logger, "Got broadcast of latest holder commitment tx {}, searching for available HTLCs to claim", commitment_txid);
2804                         let res = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, height);
2805                         let mut to_watch = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, tx);
2806                         append_onchain_update!(res, to_watch);
2807                         fail_unbroadcast_htlcs!(self, "latest holder", commitment_txid, tx, height,
2808                                 block_hash, self.current_holder_commitment_tx.htlc_outputs.iter()
2809                                 .map(|(htlc, _, htlc_source)| (htlc, htlc_source.as_ref())), logger);
2810                 } else if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
2811                         if holder_tx.txid == commitment_txid {
2812                                 is_holder_tx = true;
2813                                 log_info!(logger, "Got broadcast of previous holder commitment tx {}, searching for available HTLCs to claim", commitment_txid);
2814                                 let res = self.get_broadcasted_holder_claims(holder_tx, height);
2815                                 let mut to_watch = self.get_broadcasted_holder_watch_outputs(holder_tx, tx);
2816                                 append_onchain_update!(res, to_watch);
2817                                 fail_unbroadcast_htlcs!(self, "previous holder", commitment_txid, tx, height, block_hash,
2818                                         holder_tx.htlc_outputs.iter().map(|(htlc, _, htlc_source)| (htlc, htlc_source.as_ref())),
2819                                         logger);
2820                         }
2821                 }
2822
2823                 if is_holder_tx {
2824                         Some((claim_requests, (commitment_txid, watch_outputs)))
2825                 } else {
2826                         None
2827                 }
2828         }
2829
2830         pub fn get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
2831                 log_debug!(logger, "Getting signed latest holder commitment transaction!");
2832                 self.holder_tx_signed = true;
2833                 let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
2834                 let txid = commitment_tx.txid();
2835                 let mut holder_transactions = vec![commitment_tx];
2836                 // When anchor outputs are present, the HTLC transactions are only valid once the commitment
2837                 // transaction confirms.
2838                 if self.onchain_tx_handler.opt_anchors() {
2839                         return holder_transactions;
2840                 }
2841                 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
2842                         if let Some(vout) = htlc.0.transaction_output_index {
2843                                 let preimage = if !htlc.0.offered {
2844                                         if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
2845                                                 // We can't build an HTLC-Success transaction without the preimage
2846                                                 continue;
2847                                         }
2848                                 } else if htlc.0.cltv_expiry > self.best_block.height() + 1 {
2849                                         // Don't broadcast HTLC-Timeout transactions immediately as they don't meet the
2850                                         // current locktime requirements on-chain. We will broadcast them in
2851                                         // `block_confirmed` when `should_broadcast_holder_commitment_txn` returns true.
2852                                         // Note that we add + 1 as transactions are broadcastable when they can be
2853                                         // confirmed in the next block.
2854                                         continue;
2855                                 } else { None };
2856                                 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
2857                                         &::bitcoin::OutPoint { txid, vout }, &preimage) {
2858                                         holder_transactions.push(htlc_tx);
2859                                 }
2860                         }
2861                 }
2862                 // 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.
2863                 // The data will be re-generated and tracked in check_spend_holder_transaction if we get a confirmation.
2864                 holder_transactions
2865         }
2866
2867         #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
2868         /// Note that this includes possibly-locktimed-in-the-future transactions!
2869         fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
2870                 log_debug!(logger, "Getting signed copy of latest holder commitment transaction!");
2871                 let commitment_tx = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript);
2872                 let txid = commitment_tx.txid();
2873                 let mut holder_transactions = vec![commitment_tx];
2874                 // When anchor outputs are present, the HTLC transactions are only final once the commitment
2875                 // transaction confirms due to the CSV 1 encumberance.
2876                 if self.onchain_tx_handler.opt_anchors() {
2877                         return holder_transactions;
2878                 }
2879                 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
2880                         if let Some(vout) = htlc.0.transaction_output_index {
2881                                 let preimage = if !htlc.0.offered {
2882                                         if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
2883                                                 // We can't build an HTLC-Success transaction without the preimage
2884                                                 continue;
2885                                         }
2886                                 } else { None };
2887                                 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
2888                                         &::bitcoin::OutPoint { txid, vout }, &preimage) {
2889                                         holder_transactions.push(htlc_tx);
2890                                 }
2891                         }
2892                 }
2893                 holder_transactions
2894         }
2895
2896         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>
2897                 where B::Target: BroadcasterInterface,
2898                       F::Target: FeeEstimator,
2899                                         L::Target: Logger,
2900         {
2901                 let block_hash = header.block_hash();
2902                 self.best_block = BestBlock::new(block_hash, height);
2903
2904                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
2905                 self.transactions_confirmed(header, txdata, height, broadcaster, &bounded_fee_estimator, logger)
2906         }
2907
2908         fn best_block_updated<B: Deref, F: Deref, L: Deref>(
2909                 &mut self,
2910                 header: &BlockHeader,
2911                 height: u32,
2912                 broadcaster: B,
2913                 fee_estimator: &LowerBoundedFeeEstimator<F>,
2914                 logger: L,
2915         ) -> Vec<TransactionOutputs>
2916         where
2917                 B::Target: BroadcasterInterface,
2918                 F::Target: FeeEstimator,
2919                 L::Target: Logger,
2920         {
2921                 let block_hash = header.block_hash();
2922
2923                 if height > self.best_block.height() {
2924                         self.best_block = BestBlock::new(block_hash, height);
2925                         self.block_confirmed(height, block_hash, vec![], vec![], vec![], &broadcaster, &fee_estimator, &logger)
2926                 } else if block_hash != self.best_block.block_hash() {
2927                         self.best_block = BestBlock::new(block_hash, height);
2928                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height <= height);
2929                         self.onchain_tx_handler.block_disconnected(height + 1, broadcaster, fee_estimator, logger);
2930                         Vec::new()
2931                 } else { Vec::new() }
2932         }
2933
2934         fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
2935                 &mut self,
2936                 header: &BlockHeader,
2937                 txdata: &TransactionData,
2938                 height: u32,
2939                 broadcaster: B,
2940                 fee_estimator: &LowerBoundedFeeEstimator<F>,
2941                 logger: L,
2942         ) -> Vec<TransactionOutputs>
2943         where
2944                 B::Target: BroadcasterInterface,
2945                 F::Target: FeeEstimator,
2946                 L::Target: Logger,
2947         {
2948                 let txn_matched = self.filter_block(txdata);
2949                 for tx in &txn_matched {
2950                         let mut output_val = 0;
2951                         for out in tx.output.iter() {
2952                                 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
2953                                 output_val += out.value;
2954                                 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
2955                         }
2956                 }
2957
2958                 let block_hash = header.block_hash();
2959
2960                 let mut watch_outputs = Vec::new();
2961                 let mut claimable_outpoints = Vec::new();
2962                 'tx_iter: for tx in &txn_matched {
2963                         let txid = tx.txid();
2964                         // If a transaction has already been confirmed, ensure we don't bother processing it duplicatively.
2965                         if Some(txid) == self.funding_spend_confirmed {
2966                                 log_debug!(logger, "Skipping redundant processing of funding-spend tx {} as it was previously confirmed", txid);
2967                                 continue 'tx_iter;
2968                         }
2969                         for ev in self.onchain_events_awaiting_threshold_conf.iter() {
2970                                 if ev.txid == txid {
2971                                         if let Some(conf_hash) = ev.block_hash {
2972                                                 assert_eq!(header.block_hash(), conf_hash,
2973                                                         "Transaction {} was already confirmed and is being re-confirmed in a different block.\n\
2974                                                         This indicates a severe bug in the transaction connection logic - a reorg should have been processed first!", ev.txid);
2975                                         }
2976                                         log_debug!(logger, "Skipping redundant processing of confirming tx {} as it was previously confirmed", txid);
2977                                         continue 'tx_iter;
2978                                 }
2979                         }
2980                         for htlc in self.htlcs_resolved_on_chain.iter() {
2981                                 if Some(txid) == htlc.resolving_txid {
2982                                         log_debug!(logger, "Skipping redundant processing of HTLC resolution tx {} as it was previously confirmed", txid);
2983                                         continue 'tx_iter;
2984                                 }
2985                         }
2986                         for spendable_txid in self.spendable_txids_confirmed.iter() {
2987                                 if txid == *spendable_txid {
2988                                         log_debug!(logger, "Skipping redundant processing of spendable tx {} as it was previously confirmed", txid);
2989                                         continue 'tx_iter;
2990                                 }
2991                         }
2992
2993                         if tx.input.len() == 1 {
2994                                 // Assuming our keys were not leaked (in which case we're screwed no matter what),
2995                                 // commitment transactions and HTLC transactions will all only ever have one input
2996                                 // (except for HTLC transactions for channels with anchor outputs), which is an easy
2997                                 // way to filter out any potential non-matching txn for lazy filters.
2998                                 let prevout = &tx.input[0].previous_output;
2999                                 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
3000                                         let mut balance_spendable_csv = None;
3001                                         log_info!(logger, "Channel {} closed by funding output spend in txid {}.",
3002                                                 log_bytes!(self.funding_info.0.to_channel_id()), txid);
3003                                         self.funding_spend_seen = true;
3004                                         let mut commitment_tx_to_counterparty_output = None;
3005                                         if (tx.input[0].sequence.0 >> 8*3) as u8 == 0x80 && (tx.lock_time.0 >> 8*3) as u8 == 0x20 {
3006                                                 let (mut new_outpoints, new_outputs, counterparty_output_idx_sats) =
3007                                                         self.check_spend_counterparty_transaction(&tx, height, &block_hash, &logger);
3008                                                 commitment_tx_to_counterparty_output = counterparty_output_idx_sats;
3009                                                 if !new_outputs.1.is_empty() {
3010                                                         watch_outputs.push(new_outputs);
3011                                                 }
3012                                                 claimable_outpoints.append(&mut new_outpoints);
3013                                                 if new_outpoints.is_empty() {
3014                                                         if let Some((mut new_outpoints, new_outputs)) = self.check_spend_holder_transaction(&tx, height, &block_hash, &logger) {
3015                                                                 debug_assert!(commitment_tx_to_counterparty_output.is_none(),
3016                                                                         "A commitment transaction matched as both a counterparty and local commitment tx?");
3017                                                                 if !new_outputs.1.is_empty() {
3018                                                                         watch_outputs.push(new_outputs);
3019                                                                 }
3020                                                                 claimable_outpoints.append(&mut new_outpoints);
3021                                                                 balance_spendable_csv = Some(self.on_holder_tx_csv);
3022                                                         }
3023                                                 }
3024                                         }
3025                                         self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3026                                                 txid,
3027                                                 transaction: Some((*tx).clone()),
3028                                                 height,
3029                                                 block_hash: Some(block_hash),
3030                                                 event: OnchainEvent::FundingSpendConfirmation {
3031                                                         on_local_output_csv: balance_spendable_csv,
3032                                                         commitment_tx_to_counterparty_output,
3033                                                 },
3034                                         });
3035                                 }
3036                         }
3037                         if tx.input.len() >= 1 {
3038                                 // While all commitment transactions have one input, HTLC transactions may have more
3039                                 // if the HTLC was present in an anchor channel. HTLCs can also be resolved in a few
3040                                 // other ways which can have more than one output.
3041                                 for tx_input in &tx.input {
3042                                         let commitment_txid = tx_input.previous_output.txid;
3043                                         if let Some(&commitment_number) = self.counterparty_commitment_txn_on_chain.get(&commitment_txid) {
3044                                                 let (mut new_outpoints, new_outputs_option) = self.check_spend_counterparty_htlc(
3045                                                         &tx, commitment_number, &commitment_txid, height, &logger
3046                                                 );
3047                                                 claimable_outpoints.append(&mut new_outpoints);
3048                                                 if let Some(new_outputs) = new_outputs_option {
3049                                                         watch_outputs.push(new_outputs);
3050                                                 }
3051                                                 // Since there may be multiple HTLCs for this channel (all spending the
3052                                                 // same commitment tx) being claimed by the counterparty within the same
3053                                                 // transaction, and `check_spend_counterparty_htlc` already checks all the
3054                                                 // ones relevant to this channel, we can safely break from our loop.
3055                                                 break;
3056                                         }
3057                                 }
3058                                 self.is_resolving_htlc_output(&tx, height, &block_hash, &logger);
3059
3060                                 self.is_paying_spendable_output(&tx, height, &block_hash, &logger);
3061                         }
3062                 }
3063
3064                 if height > self.best_block.height() {
3065                         self.best_block = BestBlock::new(block_hash, height);
3066                 }
3067
3068                 self.block_confirmed(height, block_hash, txn_matched, watch_outputs, claimable_outpoints, &broadcaster, &fee_estimator, &logger)
3069         }
3070
3071         /// Update state for new block(s)/transaction(s) confirmed. Note that the caller must update
3072         /// `self.best_block` before calling if a new best blockchain tip is available. More
3073         /// concretely, `self.best_block` must never be at a lower height than `conf_height`, avoiding
3074         /// complexity especially in
3075         /// `OnchainTx::update_claims_view_from_requests`/`OnchainTx::update_claims_view_from_matched_txn`.
3076         ///
3077         /// `conf_height` should be set to the height at which any new transaction(s)/block(s) were
3078         /// confirmed at, even if it is not the current best height.
3079         fn block_confirmed<B: Deref, F: Deref, L: Deref>(
3080                 &mut self,
3081                 conf_height: u32,
3082                 conf_hash: BlockHash,
3083                 txn_matched: Vec<&Transaction>,
3084                 mut watch_outputs: Vec<TransactionOutputs>,
3085                 mut claimable_outpoints: Vec<PackageTemplate>,
3086                 broadcaster: &B,
3087                 fee_estimator: &LowerBoundedFeeEstimator<F>,
3088                 logger: &L,
3089         ) -> Vec<TransactionOutputs>
3090         where
3091                 B::Target: BroadcasterInterface,
3092                 F::Target: FeeEstimator,
3093                 L::Target: Logger,
3094         {
3095                 log_trace!(logger, "Processing {} matched transactions for block at height {}.", txn_matched.len(), conf_height);
3096                 debug_assert!(self.best_block.height() >= conf_height);
3097
3098                 let should_broadcast = self.should_broadcast_holder_commitment_txn(logger);
3099                 if should_broadcast {
3100                         let funding_outp = HolderFundingOutput::build(self.funding_redeemscript.clone(), self.channel_value_satoshis, self.onchain_tx_handler.opt_anchors());
3101                         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());
3102                         claimable_outpoints.push(commitment_package);
3103                         self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
3104                         let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
3105                         self.holder_tx_signed = true;
3106                         // We can't broadcast our HTLC transactions while the commitment transaction is
3107                         // unconfirmed. We'll delay doing so until we detect the confirmed commitment in
3108                         // `transactions_confirmed`.
3109                         if !self.onchain_tx_handler.opt_anchors() {
3110                                 // Because we're broadcasting a commitment transaction, we should construct the package
3111                                 // assuming it gets confirmed in the next block. Sadly, we have code which considers
3112                                 // "not yet confirmed" things as discardable, so we cannot do that here.
3113                                 let (mut new_outpoints, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
3114                                 let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &commitment_tx);
3115                                 if !new_outputs.is_empty() {
3116                                         watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
3117                                 }
3118                                 claimable_outpoints.append(&mut new_outpoints);
3119                         }
3120                 }
3121
3122                 // Find which on-chain events have reached their confirmation threshold.
3123                 let onchain_events_awaiting_threshold_conf =
3124                         self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
3125                 let mut onchain_events_reaching_threshold_conf = Vec::new();
3126                 for entry in onchain_events_awaiting_threshold_conf {
3127                         if entry.has_reached_confirmation_threshold(&self.best_block) {
3128                                 onchain_events_reaching_threshold_conf.push(entry);
3129                         } else {
3130                                 self.onchain_events_awaiting_threshold_conf.push(entry);
3131                         }
3132                 }
3133
3134                 // Used to check for duplicate HTLC resolutions.
3135                 #[cfg(debug_assertions)]
3136                 let unmatured_htlcs: Vec<_> = self.onchain_events_awaiting_threshold_conf
3137                         .iter()
3138                         .filter_map(|entry| match &entry.event {
3139                                 OnchainEvent::HTLCUpdate { source, .. } => Some(source),
3140                                 _ => None,
3141                         })
3142                         .collect();
3143                 #[cfg(debug_assertions)]
3144                 let mut matured_htlcs = Vec::new();
3145
3146                 // Produce actionable events from on-chain events having reached their threshold.
3147                 for entry in onchain_events_reaching_threshold_conf.drain(..) {
3148                         match entry.event {
3149                                 OnchainEvent::HTLCUpdate { ref source, payment_hash, htlc_value_satoshis, commitment_tx_output_idx } => {
3150                                         // Check for duplicate HTLC resolutions.
3151                                         #[cfg(debug_assertions)]
3152                                         {
3153                                                 debug_assert!(
3154                                                         unmatured_htlcs.iter().find(|&htlc| htlc == &source).is_none(),
3155                                                         "An unmature HTLC transaction conflicts with a maturing one; failed to \
3156                                                          call either transaction_unconfirmed for the conflicting transaction \
3157                                                          or block_disconnected for a block containing it.");
3158                                                 debug_assert!(
3159                                                         matured_htlcs.iter().find(|&htlc| htlc == source).is_none(),
3160                                                         "A matured HTLC transaction conflicts with a maturing one; failed to \
3161                                                          call either transaction_unconfirmed for the conflicting transaction \
3162                                                          or block_disconnected for a block containing it.");
3163                                                 matured_htlcs.push(source.clone());
3164                                         }
3165
3166                                         log_debug!(logger, "HTLC {} failure update in {} has got enough confirmations to be passed upstream",
3167                                                 log_bytes!(payment_hash.0), entry.txid);
3168                                         self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
3169                                                 payment_hash,
3170                                                 payment_preimage: None,
3171                                                 source: source.clone(),
3172                                                 htlc_value_satoshis,
3173                                         }));
3174                                         self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC {
3175                                                 commitment_tx_output_idx,
3176                                                 resolving_txid: Some(entry.txid),
3177                                                 resolving_tx: entry.transaction,
3178                                                 payment_preimage: None,
3179                                         });
3180                                 },
3181                                 OnchainEvent::MaturingOutput { descriptor } => {
3182                                         log_debug!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
3183                                         self.pending_events.push(Event::SpendableOutputs {
3184                                                 outputs: vec![descriptor]
3185                                         });
3186                                         self.spendable_txids_confirmed.push(entry.txid);
3187                                 },
3188                                 OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, preimage, .. } => {
3189                                         self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC {
3190                                                 commitment_tx_output_idx: Some(commitment_tx_output_idx),
3191                                                 resolving_txid: Some(entry.txid),
3192                                                 resolving_tx: entry.transaction,
3193                                                 payment_preimage: preimage,
3194                                         });
3195                                 },
3196                                 OnchainEvent::FundingSpendConfirmation { commitment_tx_to_counterparty_output, .. } => {
3197                                         self.funding_spend_confirmed = Some(entry.txid);
3198                                         self.confirmed_commitment_tx_counterparty_output = commitment_tx_to_counterparty_output;
3199                                 },
3200                         }
3201                 }
3202
3203                 self.onchain_tx_handler.update_claims_view_from_requests(claimable_outpoints, conf_height, self.best_block.height(), broadcaster, fee_estimator, logger);
3204                 self.onchain_tx_handler.update_claims_view_from_matched_txn(&txn_matched, conf_height, conf_hash, self.best_block.height(), broadcaster, fee_estimator, logger);
3205
3206                 // Determine new outputs to watch by comparing against previously known outputs to watch,
3207                 // updating the latter in the process.
3208                 watch_outputs.retain(|&(ref txid, ref txouts)| {
3209                         let idx_and_scripts = txouts.iter().map(|o| (o.0, o.1.script_pubkey.clone())).collect();
3210                         self.outputs_to_watch.insert(txid.clone(), idx_and_scripts).is_none()
3211                 });
3212                 #[cfg(test)]
3213                 {
3214                         // If we see a transaction for which we registered outputs previously,
3215                         // make sure the registered scriptpubkey at the expected index match
3216                         // the actual transaction output one. We failed this case before #653.
3217                         for tx in &txn_matched {
3218                                 if let Some(outputs) = self.get_outputs_to_watch().get(&tx.txid()) {
3219                                         for idx_and_script in outputs.iter() {
3220                                                 assert!((idx_and_script.0 as usize) < tx.output.len());
3221                                                 assert_eq!(tx.output[idx_and_script.0 as usize].script_pubkey, idx_and_script.1);
3222                                         }
3223                                 }
3224                         }
3225                 }
3226                 watch_outputs
3227         }
3228
3229         pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, height: u32, broadcaster: B, fee_estimator: F, logger: L)
3230                 where B::Target: BroadcasterInterface,
3231                       F::Target: FeeEstimator,
3232                       L::Target: Logger,
3233         {
3234                 log_trace!(logger, "Block {} at height {} disconnected", header.block_hash(), height);
3235
3236                 //We may discard:
3237                 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
3238                 //- maturing spendable output has transaction paying us has been disconnected
3239                 self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height < height);
3240
3241                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
3242                 self.onchain_tx_handler.block_disconnected(height, broadcaster, &bounded_fee_estimator, logger);
3243
3244                 self.best_block = BestBlock::new(header.prev_blockhash, height - 1);
3245         }
3246
3247         fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
3248                 &mut self,
3249                 txid: &Txid,
3250                 broadcaster: B,
3251                 fee_estimator: &LowerBoundedFeeEstimator<F>,
3252                 logger: L,
3253         ) where
3254                 B::Target: BroadcasterInterface,
3255                 F::Target: FeeEstimator,
3256                 L::Target: Logger,
3257         {
3258                 let mut removed_height = None;
3259                 for entry in self.onchain_events_awaiting_threshold_conf.iter() {
3260                         if entry.txid == *txid {
3261                                 removed_height = Some(entry.height);
3262                                 break;
3263                         }
3264                 }
3265
3266                 if let Some(removed_height) = removed_height {
3267                         log_info!(logger, "transaction_unconfirmed of txid {} implies height {} was reorg'd out", txid, removed_height);
3268                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| if entry.height >= removed_height {
3269                                 log_info!(logger, "Transaction {} reorg'd out", entry.txid);
3270                                 false
3271                         } else { true });
3272                 }
3273
3274                 debug_assert!(!self.onchain_events_awaiting_threshold_conf.iter().any(|ref entry| entry.txid == *txid));
3275
3276                 self.onchain_tx_handler.transaction_unconfirmed(txid, broadcaster, fee_estimator, logger);
3277         }
3278
3279         /// Filters a block's `txdata` for transactions spending watched outputs or for any child
3280         /// transactions thereof.
3281         fn filter_block<'a>(&self, txdata: &TransactionData<'a>) -> Vec<&'a Transaction> {
3282                 let mut matched_txn = HashSet::new();
3283                 txdata.iter().filter(|&&(_, tx)| {
3284                         let mut matches = self.spends_watched_output(tx);
3285                         for input in tx.input.iter() {
3286                                 if matches { break; }
3287                                 if matched_txn.contains(&input.previous_output.txid) {
3288                                         matches = true;
3289                                 }
3290                         }
3291                         if matches {
3292                                 matched_txn.insert(tx.txid());
3293                         }
3294                         matches
3295                 }).map(|(_, tx)| *tx).collect()
3296         }
3297
3298         /// Checks if a given transaction spends any watched outputs.
3299         fn spends_watched_output(&self, tx: &Transaction) -> bool {
3300                 for input in tx.input.iter() {
3301                         if let Some(outputs) = self.get_outputs_to_watch().get(&input.previous_output.txid) {
3302                                 for (idx, _script_pubkey) in outputs.iter() {
3303                                         if *idx == input.previous_output.vout {
3304                                                 #[cfg(test)]
3305                                                 {
3306                                                         // If the expected script is a known type, check that the witness
3307                                                         // appears to be spending the correct type (ie that the match would
3308                                                         // actually succeed in BIP 158/159-style filters).
3309                                                         if _script_pubkey.is_v0_p2wsh() {
3310                                                                 if input.witness.last().unwrap().to_vec() == deliberately_bogus_accepted_htlc_witness_program() {
3311                                                                         // In at least one test we use a deliberately bogus witness
3312                                                                         // script which hit an old panic. Thus, we check for that here
3313                                                                         // and avoid the assert if its the expected bogus script.
3314                                                                         return true;
3315                                                                 }
3316
3317                                                                 assert_eq!(&bitcoin::Address::p2wsh(&Script::from(input.witness.last().unwrap().to_vec()), bitcoin::Network::Bitcoin).script_pubkey(), _script_pubkey);
3318                                                         } else if _script_pubkey.is_v0_p2wpkh() {
3319                                                                 assert_eq!(&bitcoin::Address::p2wpkh(&bitcoin::PublicKey::from_slice(&input.witness.last().unwrap()).unwrap(), bitcoin::Network::Bitcoin).unwrap().script_pubkey(), _script_pubkey);
3320                                                         } else { panic!(); }
3321                                                 }
3322                                                 return true;
3323                                         }
3324                                 }
3325                         }
3326                 }
3327
3328                 false
3329         }
3330
3331         fn should_broadcast_holder_commitment_txn<L: Deref>(&self, logger: &L) -> bool where L::Target: Logger {
3332                 // There's no need to broadcast our commitment transaction if we've seen one confirmed (even
3333                 // with 1 confirmation) as it'll be rejected as duplicate/conflicting.
3334                 if self.funding_spend_confirmed.is_some() ||
3335                         self.onchain_events_awaiting_threshold_conf.iter().find(|event| match event.event {
3336                                 OnchainEvent::FundingSpendConfirmation { .. } => true,
3337                                 _ => false,
3338                         }).is_some()
3339                 {
3340                         return false;
3341                 }
3342                 // We need to consider all HTLCs which are:
3343                 //  * in any unrevoked counterparty commitment transaction, as they could broadcast said
3344                 //    transactions and we'd end up in a race, or
3345                 //  * are in our latest holder commitment transaction, as this is the thing we will
3346                 //    broadcast if we go on-chain.
3347                 // Note that we consider HTLCs which were below dust threshold here - while they don't
3348                 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
3349                 // to the source, and if we don't fail the channel we will have to ensure that the next
3350                 // updates that peer sends us are update_fails, failing the channel if not. It's probably
3351                 // easier to just fail the channel as this case should be rare enough anyway.
3352                 let height = self.best_block.height();
3353                 macro_rules! scan_commitment {
3354                         ($htlcs: expr, $holder_tx: expr) => {
3355                                 for ref htlc in $htlcs {
3356                                         // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
3357                                         // chain with enough room to claim the HTLC without our counterparty being able to
3358                                         // time out the HTLC first.
3359                                         // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
3360                                         // concern is being able to claim the corresponding inbound HTLC (on another
3361                                         // channel) before it expires. In fact, we don't even really care if our
3362                                         // counterparty here claims such an outbound HTLC after it expired as long as we
3363                                         // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
3364                                         // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
3365                                         // we give ourselves a few blocks of headroom after expiration before going
3366                                         // on-chain for an expired HTLC.
3367                                         // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
3368                                         // from us until we've reached the point where we go on-chain with the
3369                                         // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
3370                                         // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
3371                                         //  aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
3372                                         //      inbound_cltv == height + CLTV_CLAIM_BUFFER
3373                                         //      outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
3374                                         //      LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
3375                                         //      CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
3376                                         //      LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
3377                                         //  The final, above, condition is checked for statically in channelmanager
3378                                         //  with CHECK_CLTV_EXPIRY_SANITY_2.
3379                                         let htlc_outbound = $holder_tx == htlc.offered;
3380                                         if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
3381                                            (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
3382                                                 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
3383                                                 return true;
3384                                         }
3385                                 }
3386                         }
3387                 }
3388
3389                 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
3390
3391                 if let Some(ref txid) = self.current_counterparty_commitment_txid {
3392                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
3393                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
3394                         }
3395                 }
3396                 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
3397                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
3398                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
3399                         }
3400                 }
3401
3402                 false
3403         }
3404
3405         /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a holder
3406         /// or counterparty commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
3407         fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, block_hash: &BlockHash, logger: &L) where L::Target: Logger {
3408                 'outer_loop: for input in &tx.input {
3409                         let mut payment_data = None;
3410                         let htlc_claim = HTLCClaim::from_witness(&input.witness);
3411                         let revocation_sig_claim = htlc_claim == Some(HTLCClaim::Revocation);
3412                         let accepted_preimage_claim = htlc_claim == Some(HTLCClaim::AcceptedPreimage);
3413                         #[cfg(not(fuzzing))]
3414                         let accepted_timeout_claim = htlc_claim == Some(HTLCClaim::AcceptedTimeout);
3415                         let offered_preimage_claim = htlc_claim == Some(HTLCClaim::OfferedPreimage);
3416                         #[cfg(not(fuzzing))]
3417                         let offered_timeout_claim = htlc_claim == Some(HTLCClaim::OfferedTimeout);
3418
3419                         let mut payment_preimage = PaymentPreimage([0; 32]);
3420                         if offered_preimage_claim || accepted_preimage_claim {
3421                                 payment_preimage.0.copy_from_slice(input.witness.second_to_last().unwrap());
3422                         }
3423
3424                         macro_rules! log_claim {
3425                                 ($tx_info: expr, $holder_tx: expr, $htlc: expr, $source_avail: expr) => {
3426                                         let outbound_htlc = $holder_tx == $htlc.offered;
3427                                         // HTLCs must either be claimed by a matching script type or through the
3428                                         // revocation path:
3429                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
3430                                         debug_assert!(!$htlc.offered || offered_preimage_claim || offered_timeout_claim || revocation_sig_claim);
3431                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
3432                                         debug_assert!($htlc.offered || accepted_preimage_claim || accepted_timeout_claim || revocation_sig_claim);
3433                                         // Further, only exactly one of the possible spend paths should have been
3434                                         // matched by any HTLC spend:
3435                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
3436                                         debug_assert_eq!(accepted_preimage_claim as u8 + accepted_timeout_claim as u8 +
3437                                                          offered_preimage_claim as u8 + offered_timeout_claim as u8 +
3438                                                          revocation_sig_claim as u8, 1);
3439                                         if ($holder_tx && revocation_sig_claim) ||
3440                                                         (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
3441                                                 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
3442                                                         $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
3443                                                         if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
3444                                                         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" });
3445                                         } else {
3446                                                 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
3447                                                         $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
3448                                                         if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
3449                                                         if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
3450                                         }
3451                                 }
3452                         }
3453
3454                         macro_rules! check_htlc_valid_counterparty {
3455                                 ($counterparty_txid: expr, $htlc_output: expr) => {
3456                                         if let Some(txid) = $counterparty_txid {
3457                                                 for &(ref pending_htlc, ref pending_source) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
3458                                                         if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
3459                                                                 if let &Some(ref source) = pending_source {
3460                                                                         log_claim!("revoked counterparty commitment tx", false, pending_htlc, true);
3461                                                                         payment_data = Some(((**source).clone(), $htlc_output.payment_hash, $htlc_output.amount_msat));
3462                                                                         break;
3463                                                                 }
3464                                                         }
3465                                                 }
3466                                         }
3467                                 }
3468                         }
3469
3470                         macro_rules! scan_commitment {
3471                                 ($htlcs: expr, $tx_info: expr, $holder_tx: expr) => {
3472                                         for (ref htlc_output, source_option) in $htlcs {
3473                                                 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
3474                                                         if let Some(ref source) = source_option {
3475                                                                 log_claim!($tx_info, $holder_tx, htlc_output, true);
3476                                                                 // We have a resolution of an HTLC either from one of our latest
3477                                                                 // holder commitment transactions or an unrevoked counterparty commitment
3478                                                                 // transaction. This implies we either learned a preimage, the HTLC
3479                                                                 // has timed out, or we screwed up. In any case, we should now
3480                                                                 // resolve the source HTLC with the original sender.
3481                                                                 payment_data = Some(((*source).clone(), htlc_output.payment_hash, htlc_output.amount_msat));
3482                                                         } else if !$holder_tx {
3483                                                                 check_htlc_valid_counterparty!(self.current_counterparty_commitment_txid, htlc_output);
3484                                                                 if payment_data.is_none() {
3485                                                                         check_htlc_valid_counterparty!(self.prev_counterparty_commitment_txid, htlc_output);
3486                                                                 }
3487                                                         }
3488                                                         if payment_data.is_none() {
3489                                                                 log_claim!($tx_info, $holder_tx, htlc_output, false);
3490                                                                 let outbound_htlc = $holder_tx == htlc_output.offered;
3491                                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3492                                                                         txid: tx.txid(), height, block_hash: Some(*block_hash), transaction: Some(tx.clone()),
3493                                                                         event: OnchainEvent::HTLCSpendConfirmation {
3494                                                                                 commitment_tx_output_idx: input.previous_output.vout,
3495                                                                                 preimage: if accepted_preimage_claim || offered_preimage_claim {
3496                                                                                         Some(payment_preimage) } else { None },
3497                                                                                 // If this is a payment to us (ie !outbound_htlc), wait for
3498                                                                                 // the CSV delay before dropping the HTLC from claimable
3499                                                                                 // balance if the claim was an HTLC-Success transaction (ie
3500                                                                                 // accepted_preimage_claim).
3501                                                                                 on_to_local_output_csv: if accepted_preimage_claim && !outbound_htlc {
3502                                                                                         Some(self.on_holder_tx_csv) } else { None },
3503                                                                         },
3504                                                                 });
3505                                                                 continue 'outer_loop;
3506                                                         }
3507                                                 }
3508                                         }
3509                                 }
3510                         }
3511
3512                         if input.previous_output.txid == self.current_holder_commitment_tx.txid {
3513                                 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
3514                                         "our latest holder commitment tx", true);
3515                         }
3516                         if let Some(ref prev_holder_signed_commitment_tx) = self.prev_holder_signed_commitment_tx {
3517                                 if input.previous_output.txid == prev_holder_signed_commitment_tx.txid {
3518                                         scan_commitment!(prev_holder_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
3519                                                 "our previous holder commitment tx", true);
3520                                 }
3521                         }
3522                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(&input.previous_output.txid) {
3523                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
3524                                         "counterparty commitment tx", false);
3525                         }
3526
3527                         // Check that scan_commitment, above, decided there is some source worth relaying an
3528                         // HTLC resolution backwards to and figure out whether we learned a preimage from it.
3529                         if let Some((source, payment_hash, amount_msat)) = payment_data {
3530                                 if accepted_preimage_claim {
3531                                         if !self.pending_monitor_events.iter().any(
3532                                                 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update { upd.source == source } else { false }) {
3533                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3534                                                         txid: tx.txid(),
3535                                                         height,
3536                                                         block_hash: Some(*block_hash),
3537                                                         transaction: Some(tx.clone()),
3538                                                         event: OnchainEvent::HTLCSpendConfirmation {
3539                                                                 commitment_tx_output_idx: input.previous_output.vout,
3540                                                                 preimage: Some(payment_preimage),
3541                                                                 on_to_local_output_csv: None,
3542                                                         },
3543                                                 });
3544                                                 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
3545                                                         source,
3546                                                         payment_preimage: Some(payment_preimage),
3547                                                         payment_hash,
3548                                                         htlc_value_satoshis: Some(amount_msat / 1000),
3549                                                 }));
3550                                         }
3551                                 } else if offered_preimage_claim {
3552                                         if !self.pending_monitor_events.iter().any(
3553                                                 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update {
3554                                                         upd.source == source
3555                                                 } else { false }) {
3556                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3557                                                         txid: tx.txid(),
3558                                                         transaction: Some(tx.clone()),
3559                                                         height,
3560                                                         block_hash: Some(*block_hash),
3561                                                         event: OnchainEvent::HTLCSpendConfirmation {
3562                                                                 commitment_tx_output_idx: input.previous_output.vout,
3563                                                                 preimage: Some(payment_preimage),
3564                                                                 on_to_local_output_csv: None,
3565                                                         },
3566                                                 });
3567                                                 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
3568                                                         source,
3569                                                         payment_preimage: Some(payment_preimage),
3570                                                         payment_hash,
3571                                                         htlc_value_satoshis: Some(amount_msat / 1000),
3572                                                 }));
3573                                         }
3574                                 } else {
3575                                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
3576                                                 if entry.height != height { return true; }
3577                                                 match entry.event {
3578                                                         OnchainEvent::HTLCUpdate { source: ref htlc_source, .. } => {
3579                                                                 *htlc_source != source
3580                                                         },
3581                                                         _ => true,
3582                                                 }
3583                                         });
3584                                         let entry = OnchainEventEntry {
3585                                                 txid: tx.txid(),
3586                                                 transaction: Some(tx.clone()),
3587                                                 height,
3588                                                 block_hash: Some(*block_hash),
3589                                                 event: OnchainEvent::HTLCUpdate {
3590                                                         source, payment_hash,
3591                                                         htlc_value_satoshis: Some(amount_msat / 1000),
3592                                                         commitment_tx_output_idx: Some(input.previous_output.vout),
3593                                                 },
3594                                         };
3595                                         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());
3596                                         self.onchain_events_awaiting_threshold_conf.push(entry);
3597                                 }
3598                         }
3599                 }
3600         }
3601
3602         /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
3603         fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, block_hash: &BlockHash, logger: &L) where L::Target: Logger {
3604                 let mut spendable_output = None;
3605                 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
3606                         if i > ::core::u16::MAX as usize {
3607                                 // While it is possible that an output exists on chain which is greater than the
3608                                 // 2^16th output in a given transaction, this is only possible if the output is not
3609                                 // in a lightning transaction and was instead placed there by some third party who
3610                                 // wishes to give us money for no reason.
3611                                 // Namely, any lightning transactions which we pre-sign will never have anywhere
3612                                 // near 2^16 outputs both because such transactions must have ~2^16 outputs who's
3613                                 // scripts are not longer than one byte in length and because they are inherently
3614                                 // non-standard due to their size.
3615                                 // Thus, it is completely safe to ignore such outputs, and while it may result in
3616                                 // us ignoring non-lightning fund to us, that is only possible if someone fills
3617                                 // nearly a full block with garbage just to hit this case.
3618                                 continue;
3619                         }
3620                         if outp.script_pubkey == self.destination_script {
3621                                 spendable_output =  Some(SpendableOutputDescriptor::StaticOutput {
3622                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3623                                         output: outp.clone(),
3624                                 });
3625                                 break;
3626                         }
3627                         if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
3628                                 if broadcasted_holder_revokable_script.0 == outp.script_pubkey {
3629                                         spendable_output =  Some(SpendableOutputDescriptor::DelayedPaymentOutput(DelayedPaymentOutputDescriptor {
3630                                                 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3631                                                 per_commitment_point: broadcasted_holder_revokable_script.1,
3632                                                 to_self_delay: self.on_holder_tx_csv,
3633                                                 output: outp.clone(),
3634                                                 revocation_pubkey: broadcasted_holder_revokable_script.2.clone(),
3635                                                 channel_keys_id: self.channel_keys_id,
3636                                                 channel_value_satoshis: self.channel_value_satoshis,
3637                                         }));
3638                                         break;
3639                                 }
3640                         }
3641                         if self.counterparty_payment_script == outp.script_pubkey {
3642                                 spendable_output = Some(SpendableOutputDescriptor::StaticPaymentOutput(StaticPaymentOutputDescriptor {
3643                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3644                                         output: outp.clone(),
3645                                         channel_keys_id: self.channel_keys_id,
3646                                         channel_value_satoshis: self.channel_value_satoshis,
3647                                 }));
3648                                 break;
3649                         }
3650                         if self.shutdown_script.as_ref() == Some(&outp.script_pubkey) {
3651                                 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
3652                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3653                                         output: outp.clone(),
3654                                 });
3655                                 break;
3656                         }
3657                 }
3658                 if let Some(spendable_output) = spendable_output {
3659                         let entry = OnchainEventEntry {
3660                                 txid: tx.txid(),
3661                                 transaction: Some(tx.clone()),
3662                                 height,
3663                                 block_hash: Some(*block_hash),
3664                                 event: OnchainEvent::MaturingOutput { descriptor: spendable_output.clone() },
3665                         };
3666                         log_info!(logger, "Received spendable output {}, spendable at height {}", log_spendable!(spendable_output), entry.confirmation_threshold());
3667                         self.onchain_events_awaiting_threshold_conf.push(entry);
3668                 }
3669         }
3670 }
3671
3672 impl<Signer: WriteableEcdsaChannelSigner, T: Deref, F: Deref, L: Deref> chain::Listen for (ChannelMonitor<Signer>, T, F, L)
3673 where
3674         T::Target: BroadcasterInterface,
3675         F::Target: FeeEstimator,
3676         L::Target: Logger,
3677 {
3678         fn filtered_block_connected(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
3679                 self.0.block_connected(header, txdata, height, &*self.1, &*self.2, &*self.3);
3680         }
3681
3682         fn block_disconnected(&self, header: &BlockHeader, height: u32) {
3683                 self.0.block_disconnected(header, height, &*self.1, &*self.2, &*self.3);
3684         }
3685 }
3686
3687 impl<Signer: WriteableEcdsaChannelSigner, T: Deref, F: Deref, L: Deref> chain::Confirm for (ChannelMonitor<Signer>, T, F, L)
3688 where
3689         T::Target: BroadcasterInterface,
3690         F::Target: FeeEstimator,
3691         L::Target: Logger,
3692 {
3693         fn transactions_confirmed(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
3694                 self.0.transactions_confirmed(header, txdata, height, &*self.1, &*self.2, &*self.3);
3695         }
3696
3697         fn transaction_unconfirmed(&self, txid: &Txid) {
3698                 self.0.transaction_unconfirmed(txid, &*self.1, &*self.2, &*self.3);
3699         }
3700
3701         fn best_block_updated(&self, header: &BlockHeader, height: u32) {
3702                 self.0.best_block_updated(header, height, &*self.1, &*self.2, &*self.3);
3703         }
3704
3705         fn get_relevant_txids(&self) -> Vec<(Txid, Option<BlockHash>)> {
3706                 self.0.get_relevant_txids()
3707         }
3708 }
3709
3710 const MAX_ALLOC_SIZE: usize = 64*1024;
3711
3712 impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP)>
3713                 for (BlockHash, ChannelMonitor<SP::Signer>) {
3714         fn read<R: io::Read>(reader: &mut R, args: (&'a ES, &'b SP)) -> Result<Self, DecodeError> {
3715                 macro_rules! unwrap_obj {
3716                         ($key: expr) => {
3717                                 match $key {
3718                                         Ok(res) => res,
3719                                         Err(_) => return Err(DecodeError::InvalidValue),
3720                                 }
3721                         }
3722                 }
3723
3724                 let (entropy_source, signer_provider) = args;
3725
3726                 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
3727
3728                 let latest_update_id: u64 = Readable::read(reader)?;
3729                 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
3730
3731                 let destination_script = Readable::read(reader)?;
3732                 let broadcasted_holder_revokable_script = match <u8 as Readable>::read(reader)? {
3733                         0 => {
3734                                 let revokable_address = Readable::read(reader)?;
3735                                 let per_commitment_point = Readable::read(reader)?;
3736                                 let revokable_script = Readable::read(reader)?;
3737                                 Some((revokable_address, per_commitment_point, revokable_script))
3738                         },
3739                         1 => { None },
3740                         _ => return Err(DecodeError::InvalidValue),
3741                 };
3742                 let counterparty_payment_script = Readable::read(reader)?;
3743                 let shutdown_script = {
3744                         let script = <Script as Readable>::read(reader)?;
3745                         if script.is_empty() { None } else { Some(script) }
3746                 };
3747
3748                 let channel_keys_id = Readable::read(reader)?;
3749                 let holder_revocation_basepoint = Readable::read(reader)?;
3750                 // Technically this can fail and serialize fail a round-trip, but only for serialization of
3751                 // barely-init'd ChannelMonitors that we can't do anything with.
3752                 let outpoint = OutPoint {
3753                         txid: Readable::read(reader)?,
3754                         index: Readable::read(reader)?,
3755                 };
3756                 let funding_info = (outpoint, Readable::read(reader)?);
3757                 let current_counterparty_commitment_txid = Readable::read(reader)?;
3758                 let prev_counterparty_commitment_txid = Readable::read(reader)?;
3759
3760                 let counterparty_commitment_params = Readable::read(reader)?;
3761                 let funding_redeemscript = Readable::read(reader)?;
3762                 let channel_value_satoshis = Readable::read(reader)?;
3763
3764                 let their_cur_per_commitment_points = {
3765                         let first_idx = <U48 as Readable>::read(reader)?.0;
3766                         if first_idx == 0 {
3767                                 None
3768                         } else {
3769                                 let first_point = Readable::read(reader)?;
3770                                 let second_point_slice: [u8; 33] = Readable::read(reader)?;
3771                                 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
3772                                         Some((first_idx, first_point, None))
3773                                 } else {
3774                                         Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
3775                                 }
3776                         }
3777                 };
3778
3779                 let on_holder_tx_csv: u16 = Readable::read(reader)?;
3780
3781                 let commitment_secrets = Readable::read(reader)?;
3782
3783                 macro_rules! read_htlc_in_commitment {
3784                         () => {
3785                                 {
3786                                         let offered: bool = Readable::read(reader)?;
3787                                         let amount_msat: u64 = Readable::read(reader)?;
3788                                         let cltv_expiry: u32 = Readable::read(reader)?;
3789                                         let payment_hash: PaymentHash = Readable::read(reader)?;
3790                                         let transaction_output_index: Option<u32> = Readable::read(reader)?;
3791
3792                                         HTLCOutputInCommitment {
3793                                                 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
3794                                         }
3795                                 }
3796                         }
3797                 }
3798
3799                 let counterparty_claimable_outpoints_len: u64 = Readable::read(reader)?;
3800                 let mut counterparty_claimable_outpoints = HashMap::with_capacity(cmp::min(counterparty_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
3801                 for _ in 0..counterparty_claimable_outpoints_len {
3802                         let txid: Txid = Readable::read(reader)?;
3803                         let htlcs_count: u64 = Readable::read(reader)?;
3804                         let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
3805                         for _ in 0..htlcs_count {
3806                                 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
3807                         }
3808                         if let Some(_) = counterparty_claimable_outpoints.insert(txid, htlcs) {
3809                                 return Err(DecodeError::InvalidValue);
3810                         }
3811                 }
3812
3813                 let counterparty_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
3814                 let mut counterparty_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(counterparty_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
3815                 for _ in 0..counterparty_commitment_txn_on_chain_len {
3816                         let txid: Txid = Readable::read(reader)?;
3817                         let commitment_number = <U48 as Readable>::read(reader)?.0;
3818                         if let Some(_) = counterparty_commitment_txn_on_chain.insert(txid, commitment_number) {
3819                                 return Err(DecodeError::InvalidValue);
3820                         }
3821                 }
3822
3823                 let counterparty_hash_commitment_number_len: u64 = Readable::read(reader)?;
3824                 let mut counterparty_hash_commitment_number = HashMap::with_capacity(cmp::min(counterparty_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
3825                 for _ in 0..counterparty_hash_commitment_number_len {
3826                         let payment_hash: PaymentHash = Readable::read(reader)?;
3827                         let commitment_number = <U48 as Readable>::read(reader)?.0;
3828                         if let Some(_) = counterparty_hash_commitment_number.insert(payment_hash, commitment_number) {
3829                                 return Err(DecodeError::InvalidValue);
3830                         }
3831                 }
3832
3833                 let mut prev_holder_signed_commitment_tx: Option<HolderSignedTx> =
3834                         match <u8 as Readable>::read(reader)? {
3835                                 0 => None,
3836                                 1 => {
3837                                         Some(Readable::read(reader)?)
3838                                 },
3839                                 _ => return Err(DecodeError::InvalidValue),
3840                         };
3841                 let mut current_holder_commitment_tx: HolderSignedTx = Readable::read(reader)?;
3842
3843                 let current_counterparty_commitment_number = <U48 as Readable>::read(reader)?.0;
3844                 let current_holder_commitment_number = <U48 as Readable>::read(reader)?.0;
3845
3846                 let payment_preimages_len: u64 = Readable::read(reader)?;
3847                 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
3848                 for _ in 0..payment_preimages_len {
3849                         let preimage: PaymentPreimage = Readable::read(reader)?;
3850                         let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
3851                         if let Some(_) = payment_preimages.insert(hash, preimage) {
3852                                 return Err(DecodeError::InvalidValue);
3853                         }
3854                 }
3855
3856                 let pending_monitor_events_len: u64 = Readable::read(reader)?;
3857                 let mut pending_monitor_events = Some(
3858                         Vec::with_capacity(cmp::min(pending_monitor_events_len as usize, MAX_ALLOC_SIZE / (32 + 8*3))));
3859                 for _ in 0..pending_monitor_events_len {
3860                         let ev = match <u8 as Readable>::read(reader)? {
3861                                 0 => MonitorEvent::HTLCEvent(Readable::read(reader)?),
3862                                 1 => MonitorEvent::CommitmentTxConfirmed(funding_info.0),
3863                                 _ => return Err(DecodeError::InvalidValue)
3864                         };
3865                         pending_monitor_events.as_mut().unwrap().push(ev);
3866                 }
3867
3868                 let pending_events_len: u64 = Readable::read(reader)?;
3869                 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Event>()));
3870                 for _ in 0..pending_events_len {
3871                         if let Some(event) = MaybeReadable::read(reader)? {
3872                                 pending_events.push(event);
3873                         }
3874                 }
3875
3876                 let best_block = BestBlock::new(Readable::read(reader)?, Readable::read(reader)?);
3877
3878                 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
3879                 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
3880                 for _ in 0..waiting_threshold_conf_len {
3881                         if let Some(val) = MaybeReadable::read(reader)? {
3882                                 onchain_events_awaiting_threshold_conf.push(val);
3883                         }
3884                 }
3885
3886                 let outputs_to_watch_len: u64 = Readable::read(reader)?;
3887                 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>>())));
3888                 for _ in 0..outputs_to_watch_len {
3889                         let txid = Readable::read(reader)?;
3890                         let outputs_len: u64 = Readable::read(reader)?;
3891                         let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / (mem::size_of::<u32>() + mem::size_of::<Script>())));
3892                         for _ in 0..outputs_len {
3893                                 outputs.push((Readable::read(reader)?, Readable::read(reader)?));
3894                         }
3895                         if let Some(_) = outputs_to_watch.insert(txid, outputs) {
3896                                 return Err(DecodeError::InvalidValue);
3897                         }
3898                 }
3899                 let onchain_tx_handler: OnchainTxHandler<SP::Signer> = ReadableArgs::read(
3900                         reader, (entropy_source, signer_provider, channel_value_satoshis, channel_keys_id)
3901                 )?;
3902
3903                 let lockdown_from_offchain = Readable::read(reader)?;
3904                 let holder_tx_signed = Readable::read(reader)?;
3905
3906                 if let Some(prev_commitment_tx) = prev_holder_signed_commitment_tx.as_mut() {
3907                         let prev_holder_value = onchain_tx_handler.get_prev_holder_commitment_to_self_value();
3908                         if prev_holder_value.is_none() { return Err(DecodeError::InvalidValue); }
3909                         if prev_commitment_tx.to_self_value_sat == u64::max_value() {
3910                                 prev_commitment_tx.to_self_value_sat = prev_holder_value.unwrap();
3911                         } else if prev_commitment_tx.to_self_value_sat != prev_holder_value.unwrap() {
3912                                 return Err(DecodeError::InvalidValue);
3913                         }
3914                 }
3915
3916                 let cur_holder_value = onchain_tx_handler.get_cur_holder_commitment_to_self_value();
3917                 if current_holder_commitment_tx.to_self_value_sat == u64::max_value() {
3918                         current_holder_commitment_tx.to_self_value_sat = cur_holder_value;
3919                 } else if current_holder_commitment_tx.to_self_value_sat != cur_holder_value {
3920                         return Err(DecodeError::InvalidValue);
3921                 }
3922
3923                 let mut funding_spend_confirmed = None;
3924                 let mut htlcs_resolved_on_chain = Some(Vec::new());
3925                 let mut funding_spend_seen = Some(false);
3926                 let mut counterparty_node_id = None;
3927                 let mut confirmed_commitment_tx_counterparty_output = None;
3928                 let mut spendable_txids_confirmed = Some(Vec::new());
3929                 let mut counterparty_fulfilled_htlcs = Some(HashMap::new());
3930                 read_tlv_fields!(reader, {
3931                         (1, funding_spend_confirmed, option),
3932                         (3, htlcs_resolved_on_chain, vec_type),
3933                         (5, pending_monitor_events, vec_type),
3934                         (7, funding_spend_seen, option),
3935                         (9, counterparty_node_id, option),
3936                         (11, confirmed_commitment_tx_counterparty_output, option),
3937                         (13, spendable_txids_confirmed, vec_type),
3938                         (15, counterparty_fulfilled_htlcs, option),
3939                 });
3940
3941                 Ok((best_block.block_hash(), ChannelMonitor::from_impl(ChannelMonitorImpl {
3942                         latest_update_id,
3943                         commitment_transaction_number_obscure_factor,
3944
3945                         destination_script,
3946                         broadcasted_holder_revokable_script,
3947                         counterparty_payment_script,
3948                         shutdown_script,
3949
3950                         channel_keys_id,
3951                         holder_revocation_basepoint,
3952                         funding_info,
3953                         current_counterparty_commitment_txid,
3954                         prev_counterparty_commitment_txid,
3955
3956                         counterparty_commitment_params,
3957                         funding_redeemscript,
3958                         channel_value_satoshis,
3959                         their_cur_per_commitment_points,
3960
3961                         on_holder_tx_csv,
3962
3963                         commitment_secrets,
3964                         counterparty_claimable_outpoints,
3965                         counterparty_commitment_txn_on_chain,
3966                         counterparty_hash_commitment_number,
3967                         counterparty_fulfilled_htlcs: counterparty_fulfilled_htlcs.unwrap(),
3968
3969                         prev_holder_signed_commitment_tx,
3970                         current_holder_commitment_tx,
3971                         current_counterparty_commitment_number,
3972                         current_holder_commitment_number,
3973
3974                         payment_preimages,
3975                         pending_monitor_events: pending_monitor_events.unwrap(),
3976                         pending_events,
3977
3978                         onchain_events_awaiting_threshold_conf,
3979                         outputs_to_watch,
3980
3981                         onchain_tx_handler,
3982
3983                         lockdown_from_offchain,
3984                         holder_tx_signed,
3985                         funding_spend_seen: funding_spend_seen.unwrap(),
3986                         funding_spend_confirmed,
3987                         confirmed_commitment_tx_counterparty_output,
3988                         htlcs_resolved_on_chain: htlcs_resolved_on_chain.unwrap(),
3989                         spendable_txids_confirmed: spendable_txids_confirmed.unwrap(),
3990
3991                         best_block,
3992                         counterparty_node_id,
3993                 })))
3994         }
3995 }
3996
3997 #[cfg(test)]
3998 mod tests {
3999         use bitcoin::blockdata::block::BlockHeader;
4000         use bitcoin::blockdata::script::{Script, Builder};
4001         use bitcoin::blockdata::opcodes;
4002         use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, EcdsaSighashType};
4003         use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
4004         use bitcoin::util::sighash;
4005         use bitcoin::hashes::Hash;
4006         use bitcoin::hashes::sha256::Hash as Sha256;
4007         use bitcoin::hashes::hex::FromHex;
4008         use bitcoin::hash_types::{BlockHash, Txid};
4009         use bitcoin::network::constants::Network;
4010         use bitcoin::secp256k1::{SecretKey,PublicKey};
4011         use bitcoin::secp256k1::Secp256k1;
4012
4013         use hex;
4014
4015         use crate::chain::chaininterface::LowerBoundedFeeEstimator;
4016
4017         use super::ChannelMonitorUpdateStep;
4018         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};
4019         use crate::chain::{BestBlock, Confirm};
4020         use crate::chain::channelmonitor::ChannelMonitor;
4021         use crate::chain::package::{weight_offered_htlc, weight_received_htlc, weight_revoked_offered_htlc, weight_revoked_received_htlc, WEIGHT_REVOKED_OUTPUT};
4022         use crate::chain::transaction::OutPoint;
4023         use crate::chain::keysinterface::InMemorySigner;
4024         use crate::ln::{PaymentPreimage, PaymentHash};
4025         use crate::ln::chan_utils;
4026         use crate::ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
4027         use crate::ln::channelmanager::{PaymentSendFailure, PaymentId};
4028         use crate::ln::functional_test_utils::*;
4029         use crate::ln::script::ShutdownScript;
4030         use crate::util::errors::APIError;
4031         use crate::util::events::ClosureReason;
4032         use crate::util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};
4033         use crate::util::ser::{ReadableArgs, Writeable};
4034         use crate::sync::{Arc, Mutex};
4035         use crate::io;
4036         use bitcoin::{PackedLockTime, Sequence, TxMerkleNode, Witness};
4037         use crate::prelude::*;
4038
4039         fn do_test_funding_spend_refuses_updates(use_local_txn: bool) {
4040                 // Previously, monitor updates were allowed freely even after a funding-spend transaction
4041                 // confirmed. This would allow a race condition where we could receive a payment (including
4042                 // the counterparty revoking their broadcasted state!) and accept it without recourse as
4043                 // long as the ChannelMonitor receives the block first, the full commitment update dance
4044                 // occurs after the block is connected, and before the ChannelManager receives the block.
4045                 // Obviously this is an incredibly contrived race given the counterparty would be risking
4046                 // their full channel balance for it, but its worth fixing nonetheless as it makes the
4047                 // potential ChannelMonitor states simpler to reason about.
4048                 //
4049                 // This test checks said behavior, as well as ensuring a ChannelMonitorUpdate with multiple
4050                 // updates is handled correctly in such conditions.
4051                 let chanmon_cfgs = create_chanmon_cfgs(3);
4052                 let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
4053                 let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
4054                 let nodes = create_network(3, &node_cfgs, &node_chanmgrs);
4055                 let channel = create_announced_chan_between_nodes(&nodes, 0, 1);
4056                 create_announced_chan_between_nodes(&nodes, 1, 2);
4057
4058                 // Rebalance somewhat
4059                 send_payment(&nodes[0], &[&nodes[1]], 10_000_000);
4060
4061                 // First route two payments for testing at the end
4062                 let payment_preimage_1 = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 1_000_000).0;
4063                 let payment_preimage_2 = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 1_000_000).0;
4064
4065                 let local_txn = get_local_commitment_txn!(nodes[1], channel.2);
4066                 assert_eq!(local_txn.len(), 1);
4067                 let remote_txn = get_local_commitment_txn!(nodes[0], channel.2);
4068                 assert_eq!(remote_txn.len(), 3); // Commitment and two HTLC-Timeouts
4069                 check_spends!(remote_txn[1], remote_txn[0]);
4070                 check_spends!(remote_txn[2], remote_txn[0]);
4071                 let broadcast_tx = if use_local_txn { &local_txn[0] } else { &remote_txn[0] };
4072
4073                 // Connect a commitment transaction, but only to the ChainMonitor/ChannelMonitor. The
4074                 // channel is now closed, but the ChannelManager doesn't know that yet.
4075                 let new_header = BlockHeader {
4076                         version: 2, time: 0, bits: 0, nonce: 0,
4077                         prev_blockhash: nodes[0].best_block_info().0,
4078                         merkle_root: TxMerkleNode::all_zeros() };
4079                 let conf_height = nodes[0].best_block_info().1 + 1;
4080                 nodes[1].chain_monitor.chain_monitor.transactions_confirmed(&new_header,
4081                         &[(0, broadcast_tx)], conf_height);
4082
4083                 let (_, pre_update_monitor) = <(BlockHash, ChannelMonitor<InMemorySigner>)>::read(
4084                                                 &mut io::Cursor::new(&get_monitor!(nodes[1], channel.2).encode()),
4085                                                 (&nodes[1].keys_manager.backing, &nodes[1].keys_manager.backing)).unwrap();
4086
4087                 // If the ChannelManager tries to update the channel, however, the ChainMonitor will pass
4088                 // the update through to the ChannelMonitor which will refuse it (as the channel is closed).
4089                 let (route, payment_hash, _, payment_secret) = get_route_and_payment_hash!(nodes[1], nodes[0], 100_000);
4090                 unwrap_send_err!(nodes[1].node.send_payment(&route, payment_hash, &Some(payment_secret), PaymentId(payment_hash.0)),
4091                         true, APIError::ChannelUnavailable { ref err },
4092                         assert!(err.contains("ChannelMonitor storage failure")));
4093                 check_added_monitors!(nodes[1], 2); // After the failure we generate a close-channel monitor update
4094                 check_closed_broadcast!(nodes[1], true);
4095                 check_closed_event!(nodes[1], 1, ClosureReason::ProcessingError { err: "ChannelMonitor storage failure".to_string() });
4096
4097                 // Build a new ChannelMonitorUpdate which contains both the failing commitment tx update
4098                 // and provides the claim preimages for the two pending HTLCs. The first update generates
4099                 // an error, but the point of this test is to ensure the later updates are still applied.
4100                 let monitor_updates = nodes[1].chain_monitor.monitor_updates.lock().unwrap();
4101                 let mut replay_update = monitor_updates.get(&channel.2).unwrap().iter().rev().skip(1).next().unwrap().clone();
4102                 assert_eq!(replay_update.updates.len(), 1);
4103                 if let ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { .. } = replay_update.updates[0] {
4104                 } else { panic!(); }
4105                 replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_1 });
4106                 replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_2 });
4107
4108                 let broadcaster = TestBroadcaster::new(Arc::clone(&nodes[1].blocks));
4109                 assert!(
4110                         pre_update_monitor.update_monitor(&replay_update, &&broadcaster, &chanmon_cfgs[1].fee_estimator, &nodes[1].logger)
4111                         .is_err());
4112                 // Even though we error'd on the first update, we should still have generated an HTLC claim
4113                 // transaction
4114                 let txn_broadcasted = broadcaster.txn_broadcasted.lock().unwrap().split_off(0);
4115                 assert!(txn_broadcasted.len() >= 2);
4116                 let htlc_txn = txn_broadcasted.iter().filter(|tx| {
4117                         assert_eq!(tx.input.len(), 1);
4118                         tx.input[0].previous_output.txid == broadcast_tx.txid()
4119                 }).collect::<Vec<_>>();
4120                 assert_eq!(htlc_txn.len(), 2);
4121                 check_spends!(htlc_txn[0], broadcast_tx);
4122                 check_spends!(htlc_txn[1], broadcast_tx);
4123         }
4124         #[test]
4125         fn test_funding_spend_refuses_updates() {
4126                 do_test_funding_spend_refuses_updates(true);
4127                 do_test_funding_spend_refuses_updates(false);
4128         }
4129
4130         #[test]
4131         fn test_prune_preimages() {
4132                 let secp_ctx = Secp256k1::new();
4133                 let logger = Arc::new(TestLogger::new());
4134                 let broadcaster = Arc::new(TestBroadcaster {
4135                         txn_broadcasted: Mutex::new(Vec::new()),
4136                         blocks: Arc::new(Mutex::new(Vec::new()))
4137                 });
4138                 let fee_estimator = TestFeeEstimator { sat_per_kw: Mutex::new(253) };
4139
4140                 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
4141
4142                 let mut preimages = Vec::new();
4143                 {
4144                         for i in 0..20 {
4145                                 let preimage = PaymentPreimage([i; 32]);
4146                                 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
4147                                 preimages.push((preimage, hash));
4148                         }
4149                 }
4150
4151                 macro_rules! preimages_slice_to_htlc_outputs {
4152                         ($preimages_slice: expr) => {
4153                                 {
4154                                         let mut res = Vec::new();
4155                                         for (idx, preimage) in $preimages_slice.iter().enumerate() {
4156                                                 res.push((HTLCOutputInCommitment {
4157                                                         offered: true,
4158                                                         amount_msat: 0,
4159                                                         cltv_expiry: 0,
4160                                                         payment_hash: preimage.1.clone(),
4161                                                         transaction_output_index: Some(idx as u32),
4162                                                 }, None));
4163                                         }
4164                                         res
4165                                 }
4166                         }
4167                 }
4168                 macro_rules! preimages_to_holder_htlcs {
4169                         ($preimages_slice: expr) => {
4170                                 {
4171                                         let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
4172                                         let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
4173                                         res
4174                                 }
4175                         }
4176                 }
4177
4178                 macro_rules! test_preimages_exist {
4179                         ($preimages_slice: expr, $monitor: expr) => {
4180                                 for preimage in $preimages_slice {
4181                                         assert!($monitor.inner.lock().unwrap().payment_preimages.contains_key(&preimage.1));
4182                                 }
4183                         }
4184                 }
4185
4186                 let keys = InMemorySigner::new(
4187                         &secp_ctx,
4188                         SecretKey::from_slice(&[41; 32]).unwrap(),
4189                         SecretKey::from_slice(&[41; 32]).unwrap(),
4190                         SecretKey::from_slice(&[41; 32]).unwrap(),
4191                         SecretKey::from_slice(&[41; 32]).unwrap(),
4192                         SecretKey::from_slice(&[41; 32]).unwrap(),
4193                         [41; 32],
4194                         0,
4195                         [0; 32],
4196                 );
4197
4198                 let counterparty_pubkeys = ChannelPublicKeys {
4199                         funding_pubkey: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
4200                         revocation_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
4201                         payment_point: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[46; 32]).unwrap()),
4202                         delayed_payment_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[47; 32]).unwrap()),
4203                         htlc_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[48; 32]).unwrap())
4204                 };
4205                 let funding_outpoint = OutPoint { txid: Txid::all_zeros(), index: u16::max_value() };
4206                 let channel_parameters = ChannelTransactionParameters {
4207                         holder_pubkeys: keys.holder_channel_pubkeys.clone(),
4208                         holder_selected_contest_delay: 66,
4209                         is_outbound_from_holder: true,
4210                         counterparty_parameters: Some(CounterpartyChannelTransactionParameters {
4211                                 pubkeys: counterparty_pubkeys,
4212                                 selected_contest_delay: 67,
4213                         }),
4214                         funding_outpoint: Some(funding_outpoint),
4215                         opt_anchors: None,
4216                         opt_non_zero_fee_anchors: None,
4217                 };
4218                 // Prune with one old state and a holder commitment tx holding a few overlaps with the
4219                 // old state.
4220                 let shutdown_pubkey = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
4221                 let best_block = BestBlock::from_network(Network::Testnet);
4222                 let monitor = ChannelMonitor::new(Secp256k1::new(), keys,
4223                                                   Some(ShutdownScript::new_p2wpkh_from_pubkey(shutdown_pubkey).into_inner()), 0, &Script::new(),
4224                                                   (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
4225                                                   &channel_parameters,
4226                                                   Script::new(), 46, 0,
4227                                                   HolderCommitmentTransaction::dummy(), best_block, dummy_key);
4228
4229                 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..10])).unwrap();
4230                 monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"1").into_inner()),
4231                         preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
4232                 monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"2").into_inner()),
4233                         preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
4234                 for &(ref preimage, ref hash) in preimages.iter() {
4235                         let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&fee_estimator);
4236                         monitor.provide_payment_preimage(hash, preimage, &broadcaster, &bounded_fee_estimator, &logger);
4237                 }
4238
4239                 // Now provide a secret, pruning preimages 10-15
4240                 let mut secret = [0; 32];
4241                 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
4242                 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
4243                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 15);
4244                 test_preimages_exist!(&preimages[0..10], monitor);
4245                 test_preimages_exist!(&preimages[15..20], monitor);
4246
4247                 monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"3").into_inner()),
4248                         preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
4249
4250                 // Now provide a further secret, pruning preimages 15-17
4251                 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
4252                 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
4253                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 13);
4254                 test_preimages_exist!(&preimages[0..10], monitor);
4255                 test_preimages_exist!(&preimages[17..20], monitor);
4256
4257                 monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"4").into_inner()),
4258                         preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
4259
4260                 // Now update holder commitment tx info, pruning only element 18 as we still care about the
4261                 // previous commitment tx's preimages too
4262                 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..5])).unwrap();
4263                 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
4264                 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
4265                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 12);
4266                 test_preimages_exist!(&preimages[0..10], monitor);
4267                 test_preimages_exist!(&preimages[18..20], monitor);
4268
4269                 // But if we do it again, we'll prune 5-10
4270                 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..3])).unwrap();
4271                 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
4272                 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
4273                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 5);
4274                 test_preimages_exist!(&preimages[0..5], monitor);
4275         }
4276
4277         #[test]
4278         fn test_claim_txn_weight_computation() {
4279                 // We test Claim txn weight, knowing that we want expected weigth and
4280                 // not actual case to avoid sigs and time-lock delays hell variances.
4281
4282                 let secp_ctx = Secp256k1::new();
4283                 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
4284                 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
4285
4286                 macro_rules! sign_input {
4287                         ($sighash_parts: expr, $idx: expr, $amount: expr, $weight: expr, $sum_actual_sigs: expr, $opt_anchors: expr) => {
4288                                 let htlc = HTLCOutputInCommitment {
4289                                         offered: if *$weight == weight_revoked_offered_htlc($opt_anchors) || *$weight == weight_offered_htlc($opt_anchors) { true } else { false },
4290                                         amount_msat: 0,
4291                                         cltv_expiry: 2 << 16,
4292                                         payment_hash: PaymentHash([1; 32]),
4293                                         transaction_output_index: Some($idx as u32),
4294                                 };
4295                                 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, $opt_anchors, &pubkey, &pubkey, &pubkey) };
4296                                 let sighash = hash_to_message!(&$sighash_parts.segwit_signature_hash($idx, &redeem_script, $amount, EcdsaSighashType::All).unwrap()[..]);
4297                                 let sig = secp_ctx.sign_ecdsa(&sighash, &privkey);
4298                                 let mut ser_sig = sig.serialize_der().to_vec();
4299                                 ser_sig.push(EcdsaSighashType::All as u8);
4300                                 $sum_actual_sigs += ser_sig.len();
4301                                 let witness = $sighash_parts.witness_mut($idx).unwrap();
4302                                 witness.push(ser_sig);
4303                                 if *$weight == WEIGHT_REVOKED_OUTPUT {
4304                                         witness.push(vec!(1));
4305                                 } else if *$weight == weight_revoked_offered_htlc($opt_anchors) || *$weight == weight_revoked_received_htlc($opt_anchors) {
4306                                         witness.push(pubkey.clone().serialize().to_vec());
4307                                 } else if *$weight == weight_received_htlc($opt_anchors) {
4308                                         witness.push(vec![0]);
4309                                 } else {
4310                                         witness.push(PaymentPreimage([1; 32]).0.to_vec());
4311                                 }
4312                                 witness.push(redeem_script.into_bytes());
4313                                 let witness = witness.to_vec();
4314                                 println!("witness[0] {}", witness[0].len());
4315                                 println!("witness[1] {}", witness[1].len());
4316                                 println!("witness[2] {}", witness[2].len());
4317                         }
4318                 }
4319
4320                 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
4321                 let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
4322
4323                 // Justice tx with 1 to_holder, 2 revoked offered HTLCs, 1 revoked received HTLCs
4324                 for &opt_anchors in [false, true].iter() {
4325                         let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
4326                         let mut sum_actual_sigs = 0;
4327                         for i in 0..4 {
4328                                 claim_tx.input.push(TxIn {
4329                                         previous_output: BitcoinOutPoint {
4330                                                 txid,
4331                                                 vout: i,
4332                                         },
4333                                         script_sig: Script::new(),
4334                                         sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
4335                                         witness: Witness::new(),
4336                                 });
4337                         }
4338                         claim_tx.output.push(TxOut {
4339                                 script_pubkey: script_pubkey.clone(),
4340                                 value: 0,
4341                         });
4342                         let base_weight = claim_tx.weight();
4343                         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)];
4344                         let mut inputs_total_weight = 2; // count segwit flags
4345                         {
4346                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
4347                                 for (idx, inp) in inputs_weight.iter().enumerate() {
4348                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
4349                                         inputs_total_weight += inp;
4350                                 }
4351                         }
4352                         assert_eq!(base_weight + inputs_total_weight as usize,  claim_tx.weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
4353                 }
4354
4355                 // Claim tx with 1 offered HTLCs, 3 received HTLCs
4356                 for &opt_anchors in [false, true].iter() {
4357                         let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
4358                         let mut sum_actual_sigs = 0;
4359                         for i in 0..4 {
4360                                 claim_tx.input.push(TxIn {
4361                                         previous_output: BitcoinOutPoint {
4362                                                 txid,
4363                                                 vout: i,
4364                                         },
4365                                         script_sig: Script::new(),
4366                                         sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
4367                                         witness: Witness::new(),
4368                                 });
4369                         }
4370                         claim_tx.output.push(TxOut {
4371                                 script_pubkey: script_pubkey.clone(),
4372                                 value: 0,
4373                         });
4374                         let base_weight = claim_tx.weight();
4375                         let inputs_weight = vec![weight_offered_htlc(opt_anchors), weight_received_htlc(opt_anchors), weight_received_htlc(opt_anchors), weight_received_htlc(opt_anchors)];
4376                         let mut inputs_total_weight = 2; // count segwit flags
4377                         {
4378                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
4379                                 for (idx, inp) in inputs_weight.iter().enumerate() {
4380                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
4381                                         inputs_total_weight += inp;
4382                                 }
4383                         }
4384                         assert_eq!(base_weight + inputs_total_weight as usize,  claim_tx.weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
4385                 }
4386
4387                 // Justice tx with 1 revoked HTLC-Success tx output
4388                 for &opt_anchors in [false, true].iter() {
4389                         let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
4390                         let mut sum_actual_sigs = 0;
4391                         claim_tx.input.push(TxIn {
4392                                 previous_output: BitcoinOutPoint {
4393                                         txid,
4394                                         vout: 0,
4395                                 },
4396                                 script_sig: Script::new(),
4397                                 sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
4398                                 witness: Witness::new(),
4399                         });
4400                         claim_tx.output.push(TxOut {
4401                                 script_pubkey: script_pubkey.clone(),
4402                                 value: 0,
4403                         });
4404                         let base_weight = claim_tx.weight();
4405                         let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT];
4406                         let mut inputs_total_weight = 2; // count segwit flags
4407                         {
4408                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
4409                                 for (idx, inp) in inputs_weight.iter().enumerate() {
4410                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
4411                                         inputs_total_weight += inp;
4412                                 }
4413                         }
4414                         assert_eq!(base_weight + inputs_total_weight as usize, claim_tx.weight() + /* max_length_isg */ (73 * inputs_weight.len() - sum_actual_sigs));
4415                 }
4416         }
4417
4418         // Further testing is done in the ChannelManager integration tests.
4419 }