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Track claimed outbound HTLCs in ChannelMonitors
[rust-lightning] / lightning / src / chain / channelmonitor.rs
1 // This file is Copyright its original authors, visible in version control
2 // history.
3 //
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
8 // licenses.
9
10 //! The logic to monitor for on-chain transactions and create the relevant claim responses lives
11 //! here.
12 //!
13 //! ChannelMonitor objects are generated by ChannelManager in response to relevant
14 //! messages/actions, and MUST be persisted to disk (and, preferably, remotely) before progress can
15 //! be made in responding to certain messages, see [`chain::Watch`] for more.
16 //!
17 //! Note that ChannelMonitors are an important part of the lightning trust model and a copy of the
18 //! latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date
19 //! ChannelMonitors should do so). Thus, if you're building rust-lightning into an HSM or other
20 //! security-domain-separated system design, you should consider having multiple paths for
21 //! ChannelMonitors to get out of the HSM and onto monitoring devices.
22
23 use bitcoin::blockdata::block::BlockHeader;
24 use bitcoin::blockdata::transaction::{OutPoint as BitcoinOutPoint, TxOut, Transaction};
25 use bitcoin::blockdata::script::{Script, Builder};
26 use bitcoin::blockdata::opcodes;
27
28 use bitcoin::hashes::Hash;
29 use bitcoin::hashes::sha256::Hash as Sha256;
30 use bitcoin::hash_types::{Txid, BlockHash, WPubkeyHash};
31
32 use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature};
33 use bitcoin::secp256k1::{SecretKey, PublicKey};
34 use bitcoin::secp256k1;
35
36 use crate::ln::{PaymentHash, PaymentPreimage};
37 use crate::ln::msgs::DecodeError;
38 use crate::ln::chan_utils;
39 use crate::ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, HTLCClaim, ChannelTransactionParameters, HolderCommitmentTransaction};
40 use crate::ln::channelmanager::{HTLCSource, SentHTLCId};
41 use crate::chain;
42 use crate::chain::{BestBlock, WatchedOutput};
43 use crate::chain::chaininterface::{BroadcasterInterface, FeeEstimator, LowerBoundedFeeEstimator};
44 use crate::chain::transaction::{OutPoint, TransactionData};
45 use crate::chain::keysinterface::{SpendableOutputDescriptor, StaticPaymentOutputDescriptor, DelayedPaymentOutputDescriptor, WriteableEcdsaChannelSigner, SignerProvider, EntropySource};
46 #[cfg(anchors)]
47 use crate::chain::onchaintx::ClaimEvent;
48 use crate::chain::onchaintx::OnchainTxHandler;
49 use crate::chain::package::{CounterpartyOfferedHTLCOutput, CounterpartyReceivedHTLCOutput, HolderFundingOutput, HolderHTLCOutput, PackageSolvingData, PackageTemplate, RevokedOutput, RevokedHTLCOutput};
50 use crate::chain::Filter;
51 use crate::util::logger::Logger;
52 use crate::util::ser::{Readable, ReadableArgs, RequiredWrapper, MaybeReadable, UpgradableRequired, Writer, Writeable, U48};
53 use crate::util::byte_utils;
54 use crate::util::events::Event;
55 #[cfg(anchors)]
56 use crate::util::events::{AnchorDescriptor, HTLCDescriptor, BumpTransactionEvent};
57
58 use crate::prelude::*;
59 use core::{cmp, mem};
60 use crate::io::{self, Error};
61 use core::convert::TryInto;
62 use core::ops::Deref;
63 use crate::sync::{Mutex, LockTestExt};
64
65 /// An update generated by the underlying channel itself which contains some new information the
66 /// [`ChannelMonitor`] should be made aware of.
67 ///
68 /// Because this represents only a small number of updates to the underlying state, it is generally
69 /// much smaller than a full [`ChannelMonitor`]. However, for large single commitment transaction
70 /// updates (e.g. ones during which there are hundreds of HTLCs pending on the commitment
71 /// transaction), a single update may reach upwards of 1 MiB in serialized size.
72 #[cfg_attr(any(test, fuzzing, feature = "_test_utils"), derive(PartialEq, Eq))]
73 #[derive(Clone)]
74 #[must_use]
75 pub struct ChannelMonitorUpdate {
76         pub(crate) updates: Vec<ChannelMonitorUpdateStep>,
77         /// The sequence number of this update. Updates *must* be replayed in-order according to this
78         /// sequence number (and updates may panic if they are not). The update_id values are strictly
79         /// increasing and increase by one for each new update, with one exception specified below.
80         ///
81         /// This sequence number is also used to track up to which points updates which returned
82         /// [`ChannelMonitorUpdateStatus::InProgress`] have been applied to all copies of a given
83         /// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
84         ///
85         /// The only instance where update_id values are not strictly increasing is the case where we
86         /// allow post-force-close updates with a special update ID of [`CLOSED_CHANNEL_UPDATE_ID`]. See
87         /// its docs for more details.
88         ///
89         /// [`ChannelMonitorUpdateStatus::InProgress`]: super::ChannelMonitorUpdateStatus::InProgress
90         pub update_id: u64,
91 }
92
93 /// If:
94 ///    (1) a channel has been force closed and
95 ///    (2) we receive a preimage from a forward link that allows us to spend an HTLC output on
96 ///        this channel's (the backward link's) broadcasted commitment transaction
97 /// then we allow the `ChannelManager` to send a `ChannelMonitorUpdate` with this update ID,
98 /// with the update providing said payment preimage. No other update types are allowed after
99 /// force-close.
100 pub const CLOSED_CHANNEL_UPDATE_ID: u64 = core::u64::MAX;
101
102 impl Writeable for ChannelMonitorUpdate {
103         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
104                 write_ver_prefix!(w, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
105                 self.update_id.write(w)?;
106                 (self.updates.len() as u64).write(w)?;
107                 for update_step in self.updates.iter() {
108                         update_step.write(w)?;
109                 }
110                 write_tlv_fields!(w, {});
111                 Ok(())
112         }
113 }
114 impl Readable for ChannelMonitorUpdate {
115         fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
116                 let _ver = read_ver_prefix!(r, SERIALIZATION_VERSION);
117                 let update_id: u64 = Readable::read(r)?;
118                 let len: u64 = Readable::read(r)?;
119                 let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::core::mem::size_of::<ChannelMonitorUpdateStep>()));
120                 for _ in 0..len {
121                         if let Some(upd) = MaybeReadable::read(r)? {
122                                 updates.push(upd);
123                         }
124                 }
125                 read_tlv_fields!(r, {});
126                 Ok(Self { update_id, updates })
127         }
128 }
129
130 /// An event to be processed by the ChannelManager.
131 #[derive(Clone, PartialEq, Eq)]
132 pub enum MonitorEvent {
133         /// A monitor event containing an HTLCUpdate.
134         HTLCEvent(HTLCUpdate),
135
136         /// A monitor event that the Channel's commitment transaction was confirmed.
137         CommitmentTxConfirmed(OutPoint),
138
139         /// Indicates a [`ChannelMonitor`] update has completed. See
140         /// [`ChannelMonitorUpdateStatus::InProgress`] for more information on how this is used.
141         ///
142         /// [`ChannelMonitorUpdateStatus::InProgress`]: super::ChannelMonitorUpdateStatus::InProgress
143         Completed {
144                 /// The funding outpoint of the [`ChannelMonitor`] that was updated
145                 funding_txo: OutPoint,
146                 /// The Update ID from [`ChannelMonitorUpdate::update_id`] which was applied or
147                 /// [`ChannelMonitor::get_latest_update_id`].
148                 ///
149                 /// Note that this should only be set to a given update's ID if all previous updates for the
150                 /// same [`ChannelMonitor`] have been applied and persisted.
151                 monitor_update_id: u64,
152         },
153
154         /// Indicates a [`ChannelMonitor`] update has failed. See
155         /// [`ChannelMonitorUpdateStatus::PermanentFailure`] for more information on how this is used.
156         ///
157         /// [`ChannelMonitorUpdateStatus::PermanentFailure`]: super::ChannelMonitorUpdateStatus::PermanentFailure
158         UpdateFailed(OutPoint),
159 }
160 impl_writeable_tlv_based_enum_upgradable!(MonitorEvent,
161         // Note that Completed and UpdateFailed are currently never serialized to disk as they are
162         // generated only in ChainMonitor
163         (0, Completed) => {
164                 (0, funding_txo, required),
165                 (2, monitor_update_id, required),
166         },
167 ;
168         (2, HTLCEvent),
169         (4, CommitmentTxConfirmed),
170         (6, UpdateFailed),
171 );
172
173 /// Simple structure sent back by `chain::Watch` when an HTLC from a forward channel is detected on
174 /// chain. Used to update the corresponding HTLC in the backward channel. Failing to pass the
175 /// preimage claim backward will lead to loss of funds.
176 #[derive(Clone, PartialEq, Eq)]
177 pub struct HTLCUpdate {
178         pub(crate) payment_hash: PaymentHash,
179         pub(crate) payment_preimage: Option<PaymentPreimage>,
180         pub(crate) source: HTLCSource,
181         pub(crate) htlc_value_satoshis: Option<u64>,
182 }
183 impl_writeable_tlv_based!(HTLCUpdate, {
184         (0, payment_hash, required),
185         (1, htlc_value_satoshis, option),
186         (2, source, required),
187         (4, payment_preimage, option),
188 });
189
190 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
191 /// instead claiming it in its own individual transaction.
192 pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
193 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
194 /// HTLC-Success transaction.
195 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
196 /// transaction confirmed (and we use it in a few more, equivalent, places).
197 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 18;
198 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
199 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
200 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
201 /// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
202 /// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
203 /// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
204 /// due to expiration but increase the cost of funds being locked longuer in case of failure.
205 /// This delay also cover a low-power peer being slow to process blocks and so being behind us on
206 /// accurate block height.
207 /// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
208 /// with at worst this delay, so we are not only using this value as a mercy for them but also
209 /// us as a safeguard to delay with enough time.
210 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
211 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding
212 /// inbound HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us
213 /// losing money.
214 ///
215 /// Note that this is a library-wide security assumption. If a reorg deeper than this number of
216 /// blocks occurs, counterparties may be able to steal funds or claims made by and balances exposed
217 /// by a  [`ChannelMonitor`] may be incorrect.
218 // We also use this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
219 // It may cause spurious generation of bumped claim txn but that's alright given the outpoint is already
220 // solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
221 // keep bumping another claim tx to solve the outpoint.
222 pub const ANTI_REORG_DELAY: u32 = 6;
223 /// Number of blocks before confirmation at which we fail back an un-relayed HTLC or at which we
224 /// refuse to accept a new HTLC.
225 ///
226 /// This is used for a few separate purposes:
227 /// 1) if we've received an MPP HTLC to us and it expires within this many blocks and we are
228 ///    waiting on additional parts (or waiting on the preimage for any HTLC from the user), we will
229 ///    fail this HTLC,
230 /// 2) if we receive an HTLC within this many blocks of its expiry (plus one to avoid a race
231 ///    condition with the above), we will fail this HTLC without telling the user we received it,
232 ///
233 /// (1) is all about protecting us - we need enough time to update the channel state before we hit
234 /// CLTV_CLAIM_BUFFER, at which point we'd go on chain to claim the HTLC with the preimage.
235 ///
236 /// (2) is the same, but with an additional buffer to avoid accepting an HTLC which is immediately
237 /// in a race condition between the user connecting a block (which would fail it) and the user
238 /// providing us the preimage (which would claim it).
239 pub(crate) const HTLC_FAIL_BACK_BUFFER: u32 = CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS;
240
241 // TODO(devrandom) replace this with HolderCommitmentTransaction
242 #[derive(Clone, PartialEq, Eq)]
243 struct HolderSignedTx {
244         /// txid of the transaction in tx, just used to make comparison faster
245         txid: Txid,
246         revocation_key: PublicKey,
247         a_htlc_key: PublicKey,
248         b_htlc_key: PublicKey,
249         delayed_payment_key: PublicKey,
250         per_commitment_point: PublicKey,
251         htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
252         to_self_value_sat: u64,
253         feerate_per_kw: u32,
254 }
255 impl_writeable_tlv_based!(HolderSignedTx, {
256         (0, txid, required),
257         // Note that this is filled in with data from OnchainTxHandler if it's missing.
258         // For HolderSignedTx objects serialized with 0.0.100+, this should be filled in.
259         (1, to_self_value_sat, (default_value, u64::max_value())),
260         (2, revocation_key, required),
261         (4, a_htlc_key, required),
262         (6, b_htlc_key, required),
263         (8, delayed_payment_key, required),
264         (10, per_commitment_point, required),
265         (12, feerate_per_kw, required),
266         (14, htlc_outputs, vec_type)
267 });
268
269 #[cfg(anchors)]
270 impl HolderSignedTx {
271         fn non_dust_htlcs(&self) -> Vec<HTLCOutputInCommitment> {
272                 self.htlc_outputs.iter().filter_map(|(htlc, _, _)| {
273                         if let Some(_) = htlc.transaction_output_index {
274                                 Some(htlc.clone())
275                         } else {
276                                 None
277                         }
278                 })
279                 .collect()
280         }
281 }
282
283 /// We use this to track static counterparty commitment transaction data and to generate any
284 /// justice or 2nd-stage preimage/timeout transactions.
285 #[derive(PartialEq, Eq)]
286 struct CounterpartyCommitmentParameters {
287         counterparty_delayed_payment_base_key: PublicKey,
288         counterparty_htlc_base_key: PublicKey,
289         on_counterparty_tx_csv: u16,
290 }
291
292 impl Writeable for CounterpartyCommitmentParameters {
293         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
294                 w.write_all(&(0 as u64).to_be_bytes())?;
295                 write_tlv_fields!(w, {
296                         (0, self.counterparty_delayed_payment_base_key, required),
297                         (2, self.counterparty_htlc_base_key, required),
298                         (4, self.on_counterparty_tx_csv, required),
299                 });
300                 Ok(())
301         }
302 }
303 impl Readable for CounterpartyCommitmentParameters {
304         fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
305                 let counterparty_commitment_transaction = {
306                         // Versions prior to 0.0.100 had some per-HTLC state stored here, which is no longer
307                         // used. Read it for compatibility.
308                         let per_htlc_len: u64 = Readable::read(r)?;
309                         for _  in 0..per_htlc_len {
310                                 let _txid: Txid = Readable::read(r)?;
311                                 let htlcs_count: u64 = Readable::read(r)?;
312                                 for _ in 0..htlcs_count {
313                                         let _htlc: HTLCOutputInCommitment = Readable::read(r)?;
314                                 }
315                         }
316
317                         let mut counterparty_delayed_payment_base_key = RequiredWrapper(None);
318                         let mut counterparty_htlc_base_key = RequiredWrapper(None);
319                         let mut on_counterparty_tx_csv: u16 = 0;
320                         read_tlv_fields!(r, {
321                                 (0, counterparty_delayed_payment_base_key, required),
322                                 (2, counterparty_htlc_base_key, required),
323                                 (4, on_counterparty_tx_csv, required),
324                         });
325                         CounterpartyCommitmentParameters {
326                                 counterparty_delayed_payment_base_key: counterparty_delayed_payment_base_key.0.unwrap(),
327                                 counterparty_htlc_base_key: counterparty_htlc_base_key.0.unwrap(),
328                                 on_counterparty_tx_csv,
329                         }
330                 };
331                 Ok(counterparty_commitment_transaction)
332         }
333 }
334
335 /// An entry for an [`OnchainEvent`], stating the block height and hash when the event was
336 /// observed, as well as the transaction causing it.
337 ///
338 /// Used to determine when the on-chain event can be considered safe from a chain reorganization.
339 #[derive(PartialEq, Eq)]
340 struct OnchainEventEntry {
341         txid: Txid,
342         height: u32,
343         block_hash: Option<BlockHash>, // Added as optional, will be filled in for any entry generated on 0.0.113 or after
344         event: OnchainEvent,
345         transaction: Option<Transaction>, // Added as optional, but always filled in, in LDK 0.0.110
346 }
347
348 impl OnchainEventEntry {
349         fn confirmation_threshold(&self) -> u32 {
350                 let mut conf_threshold = self.height + ANTI_REORG_DELAY - 1;
351                 match self.event {
352                         OnchainEvent::MaturingOutput {
353                                 descriptor: SpendableOutputDescriptor::DelayedPaymentOutput(ref descriptor)
354                         } => {
355                                 // A CSV'd transaction is confirmable in block (input height) + CSV delay, which means
356                                 // it's broadcastable when we see the previous block.
357                                 conf_threshold = cmp::max(conf_threshold, self.height + descriptor.to_self_delay as u32 - 1);
358                         },
359                         OnchainEvent::FundingSpendConfirmation { on_local_output_csv: Some(csv), .. } |
360                         OnchainEvent::HTLCSpendConfirmation { on_to_local_output_csv: Some(csv), .. } => {
361                                 // A CSV'd transaction is confirmable in block (input height) + CSV delay, which means
362                                 // it's broadcastable when we see the previous block.
363                                 conf_threshold = cmp::max(conf_threshold, self.height + csv as u32 - 1);
364                         },
365                         _ => {},
366                 }
367                 conf_threshold
368         }
369
370         fn has_reached_confirmation_threshold(&self, best_block: &BestBlock) -> bool {
371                 best_block.height() >= self.confirmation_threshold()
372         }
373 }
374
375 /// The (output index, sats value) for the counterparty's output in a commitment transaction.
376 ///
377 /// This was added as an `Option` in 0.0.110.
378 type CommitmentTxCounterpartyOutputInfo = Option<(u32, u64)>;
379
380 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
381 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
382 #[derive(PartialEq, Eq)]
383 enum OnchainEvent {
384         /// An outbound HTLC failing after a transaction is confirmed. Used
385         ///  * when an outbound HTLC output is spent by us after the HTLC timed out
386         ///  * an outbound HTLC which was not present in the commitment transaction which appeared
387         ///    on-chain (either because it was not fully committed to or it was dust).
388         /// Note that this is *not* used for preimage claims, as those are passed upstream immediately,
389         /// appearing only as an `HTLCSpendConfirmation`, below.
390         HTLCUpdate {
391                 source: HTLCSource,
392                 payment_hash: PaymentHash,
393                 htlc_value_satoshis: Option<u64>,
394                 /// None in the second case, above, ie when there is no relevant output in the commitment
395                 /// transaction which appeared on chain.
396                 commitment_tx_output_idx: Option<u32>,
397         },
398         /// An output waiting on [`ANTI_REORG_DELAY`] confirmations before we hand the user the
399         /// [`SpendableOutputDescriptor`].
400         MaturingOutput {
401                 descriptor: SpendableOutputDescriptor,
402         },
403         /// A spend of the funding output, either a commitment transaction or a cooperative closing
404         /// transaction.
405         FundingSpendConfirmation {
406                 /// The CSV delay for the output of the funding spend transaction (implying it is a local
407                 /// commitment transaction, and this is the delay on the to_self output).
408                 on_local_output_csv: Option<u16>,
409                 /// If the funding spend transaction was a known remote commitment transaction, we track
410                 /// the output index and amount of the counterparty's `to_self` output here.
411                 ///
412                 /// This allows us to generate a [`Balance::CounterpartyRevokedOutputClaimable`] for the
413                 /// counterparty output.
414                 commitment_tx_to_counterparty_output: CommitmentTxCounterpartyOutputInfo,
415         },
416         /// A spend of a commitment transaction HTLC output, set in the cases where *no* `HTLCUpdate`
417         /// is constructed. This is used when
418         ///  * an outbound HTLC is claimed by our counterparty with a preimage, causing us to
419         ///    immediately claim the HTLC on the inbound edge and track the resolution here,
420         ///  * an inbound HTLC is claimed by our counterparty (with a timeout),
421         ///  * an inbound HTLC is claimed by us (with a preimage).
422         ///  * a revoked-state HTLC transaction was broadcasted, which was claimed by the revocation
423         ///    signature.
424         ///  * a revoked-state HTLC transaction was broadcasted, which was claimed by an
425         ///    HTLC-Success/HTLC-Failure transaction (and is still claimable with a revocation
426         ///    signature).
427         HTLCSpendConfirmation {
428                 commitment_tx_output_idx: u32,
429                 /// If the claim was made by either party with a preimage, this is filled in
430                 preimage: Option<PaymentPreimage>,
431                 /// If the claim was made by us on an inbound HTLC against a local commitment transaction,
432                 /// we set this to the output CSV value which we will have to wait until to spend the
433                 /// output (and generate a SpendableOutput event).
434                 on_to_local_output_csv: Option<u16>,
435         },
436 }
437
438 impl Writeable for OnchainEventEntry {
439         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
440                 write_tlv_fields!(writer, {
441                         (0, self.txid, required),
442                         (1, self.transaction, option),
443                         (2, self.height, required),
444                         (3, self.block_hash, option),
445                         (4, self.event, required),
446                 });
447                 Ok(())
448         }
449 }
450
451 impl MaybeReadable for OnchainEventEntry {
452         fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, DecodeError> {
453                 let mut txid = Txid::all_zeros();
454                 let mut transaction = None;
455                 let mut block_hash = None;
456                 let mut height = 0;
457                 let mut event = UpgradableRequired(None);
458                 read_tlv_fields!(reader, {
459                         (0, txid, required),
460                         (1, transaction, option),
461                         (2, height, required),
462                         (3, block_hash, option),
463                         (4, event, upgradable_required),
464                 });
465                 Ok(Some(Self { txid, transaction, height, block_hash, event: _init_tlv_based_struct_field!(event, upgradable_required) }))
466         }
467 }
468
469 impl_writeable_tlv_based_enum_upgradable!(OnchainEvent,
470         (0, HTLCUpdate) => {
471                 (0, source, required),
472                 (1, htlc_value_satoshis, option),
473                 (2, payment_hash, required),
474                 (3, commitment_tx_output_idx, option),
475         },
476         (1, MaturingOutput) => {
477                 (0, descriptor, required),
478         },
479         (3, FundingSpendConfirmation) => {
480                 (0, on_local_output_csv, option),
481                 (1, commitment_tx_to_counterparty_output, option),
482         },
483         (5, HTLCSpendConfirmation) => {
484                 (0, commitment_tx_output_idx, required),
485                 (2, preimage, option),
486                 (4, on_to_local_output_csv, option),
487         },
488
489 );
490
491 #[cfg_attr(any(test, fuzzing, feature = "_test_utils"), derive(PartialEq, Eq))]
492 #[derive(Clone)]
493 pub(crate) enum ChannelMonitorUpdateStep {
494         LatestHolderCommitmentTXInfo {
495                 commitment_tx: HolderCommitmentTransaction,
496                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
497                 claimed_htlcs: Vec<(SentHTLCId, PaymentPreimage)>,
498         },
499         LatestCounterpartyCommitmentTXInfo {
500                 commitment_txid: Txid,
501                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
502                 commitment_number: u64,
503                 their_per_commitment_point: PublicKey,
504         },
505         PaymentPreimage {
506                 payment_preimage: PaymentPreimage,
507         },
508         CommitmentSecret {
509                 idx: u64,
510                 secret: [u8; 32],
511         },
512         /// Used to indicate that the no future updates will occur, and likely that the latest holder
513         /// commitment transaction(s) should be broadcast, as the channel has been force-closed.
514         ChannelForceClosed {
515                 /// If set to false, we shouldn't broadcast the latest holder commitment transaction as we
516                 /// think we've fallen behind!
517                 should_broadcast: bool,
518         },
519         ShutdownScript {
520                 scriptpubkey: Script,
521         },
522 }
523
524 impl ChannelMonitorUpdateStep {
525         fn variant_name(&self) -> &'static str {
526                 match self {
527                         ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { .. } => "LatestHolderCommitmentTXInfo",
528                         ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { .. } => "LatestCounterpartyCommitmentTXInfo",
529                         ChannelMonitorUpdateStep::PaymentPreimage { .. } => "PaymentPreimage",
530                         ChannelMonitorUpdateStep::CommitmentSecret { .. } => "CommitmentSecret",
531                         ChannelMonitorUpdateStep::ChannelForceClosed { .. } => "ChannelForceClosed",
532                         ChannelMonitorUpdateStep::ShutdownScript { .. } => "ShutdownScript",
533                 }
534         }
535 }
536
537 impl_writeable_tlv_based_enum_upgradable!(ChannelMonitorUpdateStep,
538         (0, LatestHolderCommitmentTXInfo) => {
539                 (0, commitment_tx, required),
540                 (1, claimed_htlcs, vec_type),
541                 (2, htlc_outputs, vec_type),
542         },
543         (1, LatestCounterpartyCommitmentTXInfo) => {
544                 (0, commitment_txid, required),
545                 (2, commitment_number, required),
546                 (4, their_per_commitment_point, required),
547                 (6, htlc_outputs, vec_type),
548         },
549         (2, PaymentPreimage) => {
550                 (0, payment_preimage, required),
551         },
552         (3, CommitmentSecret) => {
553                 (0, idx, required),
554                 (2, secret, required),
555         },
556         (4, ChannelForceClosed) => {
557                 (0, should_broadcast, required),
558         },
559         (5, ShutdownScript) => {
560                 (0, scriptpubkey, required),
561         },
562 );
563
564 /// Details about the balance(s) available for spending once the channel appears on chain.
565 ///
566 /// See [`ChannelMonitor::get_claimable_balances`] for more details on when these will or will not
567 /// be provided.
568 #[derive(Clone, Debug, PartialEq, Eq)]
569 #[cfg_attr(test, derive(PartialOrd, Ord))]
570 pub enum Balance {
571         /// The channel is not yet closed (or the commitment or closing transaction has not yet
572         /// appeared in a block). The given balance is claimable (less on-chain fees) if the channel is
573         /// force-closed now.
574         ClaimableOnChannelClose {
575                 /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
576                 /// required to do so.
577                 claimable_amount_satoshis: u64,
578         },
579         /// The channel has been closed, and the given balance is ours but awaiting confirmations until
580         /// we consider it spendable.
581         ClaimableAwaitingConfirmations {
582                 /// The amount available to claim, in satoshis, possibly excluding the on-chain fees which
583                 /// were spent in broadcasting the transaction.
584                 claimable_amount_satoshis: u64,
585                 /// The height at which an [`Event::SpendableOutputs`] event will be generated for this
586                 /// amount.
587                 confirmation_height: u32,
588         },
589         /// The channel has been closed, and the given balance should be ours but awaiting spending
590         /// transaction confirmation. If the spending transaction does not confirm in time, it is
591         /// possible our counterparty can take the funds by broadcasting an HTLC timeout on-chain.
592         ///
593         /// Once the spending transaction confirms, before it has reached enough confirmations to be
594         /// considered safe from chain reorganizations, the balance will instead be provided via
595         /// [`Balance::ClaimableAwaitingConfirmations`].
596         ContentiousClaimable {
597                 /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
598                 /// required to do so.
599                 claimable_amount_satoshis: u64,
600                 /// The height at which the counterparty may be able to claim the balance if we have not
601                 /// done so.
602                 timeout_height: u32,
603         },
604         /// HTLCs which we sent to our counterparty which are claimable after a timeout (less on-chain
605         /// fees) if the counterparty does not know the preimage for the HTLCs. These are somewhat
606         /// likely to be claimed by our counterparty before we do.
607         MaybeTimeoutClaimableHTLC {
608                 /// The amount potentially available to claim, in satoshis, excluding the on-chain fees
609                 /// which will be required to do so.
610                 claimable_amount_satoshis: u64,
611                 /// The height at which we will be able to claim the balance if our counterparty has not
612                 /// done so.
613                 claimable_height: u32,
614         },
615         /// HTLCs which we received from our counterparty which are claimable with a preimage which we
616         /// do not currently have. This will only be claimable if we receive the preimage from the node
617         /// to which we forwarded this HTLC before the timeout.
618         MaybePreimageClaimableHTLC {
619                 /// The amount potentially available to claim, in satoshis, excluding the on-chain fees
620                 /// which will be required to do so.
621                 claimable_amount_satoshis: u64,
622                 /// The height at which our counterparty will be able to claim the balance if we have not
623                 /// yet received the preimage and claimed it ourselves.
624                 expiry_height: u32,
625         },
626         /// The channel has been closed, and our counterparty broadcasted a revoked commitment
627         /// transaction.
628         ///
629         /// Thus, we're able to claim all outputs in the commitment transaction, one of which has the
630         /// following amount.
631         CounterpartyRevokedOutputClaimable {
632                 /// The amount, in satoshis, of the output which we can claim.
633                 ///
634                 /// Note that for outputs from HTLC balances this may be excluding some on-chain fees that
635                 /// were already spent.
636                 claimable_amount_satoshis: u64,
637         },
638 }
639
640 /// An HTLC which has been irrevocably resolved on-chain, and has reached ANTI_REORG_DELAY.
641 #[derive(PartialEq, Eq)]
642 struct IrrevocablyResolvedHTLC {
643         commitment_tx_output_idx: Option<u32>,
644         /// The txid of the transaction which resolved the HTLC, this may be a commitment (if the HTLC
645         /// was not present in the confirmed commitment transaction), HTLC-Success, or HTLC-Timeout
646         /// transaction.
647         resolving_txid: Option<Txid>, // Added as optional, but always filled in, in 0.0.110
648         resolving_tx: Option<Transaction>,
649         /// Only set if the HTLC claim was ours using a payment preimage
650         payment_preimage: Option<PaymentPreimage>,
651 }
652
653 // In LDK versions prior to 0.0.111 commitment_tx_output_idx was not Option-al and
654 // IrrevocablyResolvedHTLC objects only existed for non-dust HTLCs. This was a bug, but to maintain
655 // backwards compatibility we must ensure we always write out a commitment_tx_output_idx field,
656 // using `u32::max_value()` as a sentinal to indicate the HTLC was dust.
657 impl Writeable for IrrevocablyResolvedHTLC {
658         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
659                 let mapped_commitment_tx_output_idx = self.commitment_tx_output_idx.unwrap_or(u32::max_value());
660                 write_tlv_fields!(writer, {
661                         (0, mapped_commitment_tx_output_idx, required),
662                         (1, self.resolving_txid, option),
663                         (2, self.payment_preimage, option),
664                         (3, self.resolving_tx, option),
665                 });
666                 Ok(())
667         }
668 }
669
670 impl Readable for IrrevocablyResolvedHTLC {
671         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
672                 let mut mapped_commitment_tx_output_idx = 0;
673                 let mut resolving_txid = None;
674                 let mut payment_preimage = None;
675                 let mut resolving_tx = None;
676                 read_tlv_fields!(reader, {
677                         (0, mapped_commitment_tx_output_idx, required),
678                         (1, resolving_txid, option),
679                         (2, payment_preimage, option),
680                         (3, resolving_tx, option),
681                 });
682                 Ok(Self {
683                         commitment_tx_output_idx: if mapped_commitment_tx_output_idx == u32::max_value() { None } else { Some(mapped_commitment_tx_output_idx) },
684                         resolving_txid,
685                         payment_preimage,
686                         resolving_tx,
687                 })
688         }
689 }
690
691 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
692 /// on-chain transactions to ensure no loss of funds occurs.
693 ///
694 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
695 /// information and are actively monitoring the chain.
696 ///
697 /// Pending Events or updated HTLCs which have not yet been read out by
698 /// get_and_clear_pending_monitor_events or get_and_clear_pending_events are serialized to disk and
699 /// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
700 /// gotten are fully handled before re-serializing the new state.
701 ///
702 /// Note that the deserializer is only implemented for (BlockHash, ChannelMonitor), which
703 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
704 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
705 /// returned block hash and the the current chain and then reconnecting blocks to get to the
706 /// best chain) upon deserializing the object!
707 pub struct ChannelMonitor<Signer: WriteableEcdsaChannelSigner> {
708         #[cfg(test)]
709         pub(crate) inner: Mutex<ChannelMonitorImpl<Signer>>,
710         #[cfg(not(test))]
711         inner: Mutex<ChannelMonitorImpl<Signer>>,
712 }
713
714 #[derive(PartialEq)]
715 pub(crate) struct ChannelMonitorImpl<Signer: WriteableEcdsaChannelSigner> {
716         latest_update_id: u64,
717         commitment_transaction_number_obscure_factor: u64,
718
719         destination_script: Script,
720         broadcasted_holder_revokable_script: Option<(Script, PublicKey, PublicKey)>,
721         counterparty_payment_script: Script,
722         shutdown_script: Option<Script>,
723
724         channel_keys_id: [u8; 32],
725         holder_revocation_basepoint: PublicKey,
726         funding_info: (OutPoint, Script),
727         current_counterparty_commitment_txid: Option<Txid>,
728         prev_counterparty_commitment_txid: Option<Txid>,
729
730         counterparty_commitment_params: CounterpartyCommitmentParameters,
731         funding_redeemscript: Script,
732         channel_value_satoshis: u64,
733         // first is the idx of the first of the two per-commitment points
734         their_cur_per_commitment_points: Option<(u64, PublicKey, Option<PublicKey>)>,
735
736         on_holder_tx_csv: u16,
737
738         commitment_secrets: CounterpartyCommitmentSecrets,
739         /// The set of outpoints in each counterparty commitment transaction. We always need at least
740         /// the payment hash from `HTLCOutputInCommitment` to claim even a revoked commitment
741         /// transaction broadcast as we need to be able to construct the witness script in all cases.
742         counterparty_claimable_outpoints: HashMap<Txid, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
743         /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
744         /// Nor can we figure out their commitment numbers without the commitment transaction they are
745         /// spending. Thus, in order to claim them via revocation key, we track all the counterparty
746         /// commitment transactions which we find on-chain, mapping them to the commitment number which
747         /// can be used to derive the revocation key and claim the transactions.
748         counterparty_commitment_txn_on_chain: HashMap<Txid, u64>,
749         /// Cache used to make pruning of payment_preimages faster.
750         /// Maps payment_hash values to commitment numbers for counterparty transactions for non-revoked
751         /// counterparty transactions (ie should remain pretty small).
752         /// Serialized to disk but should generally not be sent to Watchtowers.
753         counterparty_hash_commitment_number: HashMap<PaymentHash, u64>,
754
755         counterparty_fulfilled_htlcs: HashMap<SentHTLCId, PaymentPreimage>,
756
757         // We store two holder commitment transactions to avoid any race conditions where we may update
758         // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
759         // various monitors for one channel being out of sync, and us broadcasting a holder
760         // transaction for which we have deleted claim information on some watchtowers.
761         prev_holder_signed_commitment_tx: Option<HolderSignedTx>,
762         current_holder_commitment_tx: HolderSignedTx,
763
764         // Used just for ChannelManager to make sure it has the latest channel data during
765         // deserialization
766         current_counterparty_commitment_number: u64,
767         // Used just for ChannelManager to make sure it has the latest channel data during
768         // deserialization
769         current_holder_commitment_number: u64,
770
771         /// The set of payment hashes from inbound payments for which we know the preimage. Payment
772         /// preimages that are not included in any unrevoked local commitment transaction or unrevoked
773         /// remote commitment transactions are automatically removed when commitment transactions are
774         /// revoked.
775         payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
776
777         // Note that `MonitorEvent`s MUST NOT be generated during update processing, only generated
778         // during chain data processing. This prevents a race in `ChainMonitor::update_channel` (and
779         // presumably user implementations thereof as well) where we update the in-memory channel
780         // object, then before the persistence finishes (as it's all under a read-lock), we return
781         // pending events to the user or to the relevant `ChannelManager`. Then, on reload, we'll have
782         // the pre-event state here, but have processed the event in the `ChannelManager`.
783         // Note that because the `event_lock` in `ChainMonitor` is only taken in
784         // block/transaction-connected events and *not* during block/transaction-disconnected events,
785         // we further MUST NOT generate events during block/transaction-disconnection.
786         pending_monitor_events: Vec<MonitorEvent>,
787
788         pending_events: Vec<Event>,
789
790         // Used to track on-chain events (i.e., transactions part of channels confirmed on chain) on
791         // which to take actions once they reach enough confirmations. Each entry includes the
792         // transaction's id and the height when the transaction was confirmed on chain.
793         onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
794
795         // If we get serialized out and re-read, we need to make sure that the chain monitoring
796         // interface knows about the TXOs that we want to be notified of spends of. We could probably
797         // be smart and derive them from the above storage fields, but its much simpler and more
798         // Obviously Correct (tm) if we just keep track of them explicitly.
799         outputs_to_watch: HashMap<Txid, Vec<(u32, Script)>>,
800
801         #[cfg(test)]
802         pub onchain_tx_handler: OnchainTxHandler<Signer>,
803         #[cfg(not(test))]
804         onchain_tx_handler: OnchainTxHandler<Signer>,
805
806         // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
807         // channel has been force-closed. After this is set, no further holder commitment transaction
808         // updates may occur, and we panic!() if one is provided.
809         lockdown_from_offchain: bool,
810
811         // Set once we've signed a holder commitment transaction and handed it over to our
812         // OnchainTxHandler. After this is set, no future updates to our holder commitment transactions
813         // may occur, and we fail any such monitor updates.
814         //
815         // In case of update rejection due to a locally already signed commitment transaction, we
816         // nevertheless store update content to track in case of concurrent broadcast by another
817         // remote monitor out-of-order with regards to the block view.
818         holder_tx_signed: bool,
819
820         // If a spend of the funding output is seen, we set this to true and reject any further
821         // updates. This prevents any further changes in the offchain state no matter the order
822         // of block connection between ChannelMonitors and the ChannelManager.
823         funding_spend_seen: bool,
824
825         /// Set to `Some` of the confirmed transaction spending the funding input of the channel after
826         /// reaching `ANTI_REORG_DELAY` confirmations.
827         funding_spend_confirmed: Option<Txid>,
828
829         confirmed_commitment_tx_counterparty_output: CommitmentTxCounterpartyOutputInfo,
830         /// The set of HTLCs which have been either claimed or failed on chain and have reached
831         /// the requisite confirmations on the claim/fail transaction (either ANTI_REORG_DELAY or the
832         /// spending CSV for revocable outputs).
833         htlcs_resolved_on_chain: Vec<IrrevocablyResolvedHTLC>,
834
835         /// The set of `SpendableOutput` events which we have already passed upstream to be claimed.
836         /// These are tracked explicitly to ensure that we don't generate the same events redundantly
837         /// if users duplicatively confirm old transactions. Specifically for transactions claiming a
838         /// revoked remote outpoint we otherwise have no tracking at all once they've reached
839         /// [`ANTI_REORG_DELAY`], so we have to track them here.
840         spendable_txids_confirmed: Vec<Txid>,
841
842         // We simply modify best_block in Channel's block_connected so that serialization is
843         // consistent but hopefully the users' copy handles block_connected in a consistent way.
844         // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
845         // their best_block from its state and not based on updated copies that didn't run through
846         // the full block_connected).
847         best_block: BestBlock,
848
849         /// The node_id of our counterparty
850         counterparty_node_id: Option<PublicKey>,
851 }
852
853 /// Transaction outputs to watch for on-chain spends.
854 pub type TransactionOutputs = (Txid, Vec<(u32, TxOut)>);
855
856 impl<Signer: WriteableEcdsaChannelSigner> PartialEq for ChannelMonitor<Signer> where Signer: PartialEq {
857         fn eq(&self, other: &Self) -> bool {
858                 // We need some kind of total lockorder. Absent a better idea, we sort by position in
859                 // memory and take locks in that order (assuming that we can't move within memory while a
860                 // lock is held).
861                 let ord = ((self as *const _) as usize) < ((other as *const _) as usize);
862                 let a = if ord { self.inner.unsafe_well_ordered_double_lock_self() } else { other.inner.unsafe_well_ordered_double_lock_self() };
863                 let b = if ord { other.inner.unsafe_well_ordered_double_lock_self() } else { self.inner.unsafe_well_ordered_double_lock_self() };
864                 a.eq(&b)
865         }
866 }
867
868 impl<Signer: WriteableEcdsaChannelSigner> Writeable for ChannelMonitor<Signer> {
869         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
870                 self.inner.lock().unwrap().write(writer)
871         }
872 }
873
874 // These are also used for ChannelMonitorUpdate, above.
875 const SERIALIZATION_VERSION: u8 = 1;
876 const MIN_SERIALIZATION_VERSION: u8 = 1;
877
878 impl<Signer: WriteableEcdsaChannelSigner> Writeable for ChannelMonitorImpl<Signer> {
879         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
880                 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
881
882                 self.latest_update_id.write(writer)?;
883
884                 // Set in initial Channel-object creation, so should always be set by now:
885                 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
886
887                 self.destination_script.write(writer)?;
888                 if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
889                         writer.write_all(&[0; 1])?;
890                         broadcasted_holder_revokable_script.0.write(writer)?;
891                         broadcasted_holder_revokable_script.1.write(writer)?;
892                         broadcasted_holder_revokable_script.2.write(writer)?;
893                 } else {
894                         writer.write_all(&[1; 1])?;
895                 }
896
897                 self.counterparty_payment_script.write(writer)?;
898                 match &self.shutdown_script {
899                         Some(script) => script.write(writer)?,
900                         None => Script::new().write(writer)?,
901                 }
902
903                 self.channel_keys_id.write(writer)?;
904                 self.holder_revocation_basepoint.write(writer)?;
905                 writer.write_all(&self.funding_info.0.txid[..])?;
906                 writer.write_all(&self.funding_info.0.index.to_be_bytes())?;
907                 self.funding_info.1.write(writer)?;
908                 self.current_counterparty_commitment_txid.write(writer)?;
909                 self.prev_counterparty_commitment_txid.write(writer)?;
910
911                 self.counterparty_commitment_params.write(writer)?;
912                 self.funding_redeemscript.write(writer)?;
913                 self.channel_value_satoshis.write(writer)?;
914
915                 match self.their_cur_per_commitment_points {
916                         Some((idx, pubkey, second_option)) => {
917                                 writer.write_all(&byte_utils::be48_to_array(idx))?;
918                                 writer.write_all(&pubkey.serialize())?;
919                                 match second_option {
920                                         Some(second_pubkey) => {
921                                                 writer.write_all(&second_pubkey.serialize())?;
922                                         },
923                                         None => {
924                                                 writer.write_all(&[0; 33])?;
925                                         },
926                                 }
927                         },
928                         None => {
929                                 writer.write_all(&byte_utils::be48_to_array(0))?;
930                         },
931                 }
932
933                 writer.write_all(&self.on_holder_tx_csv.to_be_bytes())?;
934
935                 self.commitment_secrets.write(writer)?;
936
937                 macro_rules! serialize_htlc_in_commitment {
938                         ($htlc_output: expr) => {
939                                 writer.write_all(&[$htlc_output.offered as u8; 1])?;
940                                 writer.write_all(&$htlc_output.amount_msat.to_be_bytes())?;
941                                 writer.write_all(&$htlc_output.cltv_expiry.to_be_bytes())?;
942                                 writer.write_all(&$htlc_output.payment_hash.0[..])?;
943                                 $htlc_output.transaction_output_index.write(writer)?;
944                         }
945                 }
946
947                 writer.write_all(&(self.counterparty_claimable_outpoints.len() as u64).to_be_bytes())?;
948                 for (ref txid, ref htlc_infos) in self.counterparty_claimable_outpoints.iter() {
949                         writer.write_all(&txid[..])?;
950                         writer.write_all(&(htlc_infos.len() as u64).to_be_bytes())?;
951                         for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
952                                 debug_assert!(htlc_source.is_none() || Some(**txid) == self.current_counterparty_commitment_txid
953                                                 || Some(**txid) == self.prev_counterparty_commitment_txid,
954                                         "HTLC Sources for all revoked commitment transactions should be none!");
955                                 serialize_htlc_in_commitment!(htlc_output);
956                                 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
957                         }
958                 }
959
960                 writer.write_all(&(self.counterparty_commitment_txn_on_chain.len() as u64).to_be_bytes())?;
961                 for (ref txid, commitment_number) in self.counterparty_commitment_txn_on_chain.iter() {
962                         writer.write_all(&txid[..])?;
963                         writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
964                 }
965
966                 writer.write_all(&(self.counterparty_hash_commitment_number.len() as u64).to_be_bytes())?;
967                 for (ref payment_hash, commitment_number) in self.counterparty_hash_commitment_number.iter() {
968                         writer.write_all(&payment_hash.0[..])?;
969                         writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
970                 }
971
972                 if let Some(ref prev_holder_tx) = self.prev_holder_signed_commitment_tx {
973                         writer.write_all(&[1; 1])?;
974                         prev_holder_tx.write(writer)?;
975                 } else {
976                         writer.write_all(&[0; 1])?;
977                 }
978
979                 self.current_holder_commitment_tx.write(writer)?;
980
981                 writer.write_all(&byte_utils::be48_to_array(self.current_counterparty_commitment_number))?;
982                 writer.write_all(&byte_utils::be48_to_array(self.current_holder_commitment_number))?;
983
984                 writer.write_all(&(self.payment_preimages.len() as u64).to_be_bytes())?;
985                 for payment_preimage in self.payment_preimages.values() {
986                         writer.write_all(&payment_preimage.0[..])?;
987                 }
988
989                 writer.write_all(&(self.pending_monitor_events.iter().filter(|ev| match ev {
990                         MonitorEvent::HTLCEvent(_) => true,
991                         MonitorEvent::CommitmentTxConfirmed(_) => true,
992                         _ => false,
993                 }).count() as u64).to_be_bytes())?;
994                 for event in self.pending_monitor_events.iter() {
995                         match event {
996                                 MonitorEvent::HTLCEvent(upd) => {
997                                         0u8.write(writer)?;
998                                         upd.write(writer)?;
999                                 },
1000                                 MonitorEvent::CommitmentTxConfirmed(_) => 1u8.write(writer)?,
1001                                 _ => {}, // Covered in the TLV writes below
1002                         }
1003                 }
1004
1005                 writer.write_all(&(self.pending_events.len() as u64).to_be_bytes())?;
1006                 for event in self.pending_events.iter() {
1007                         event.write(writer)?;
1008                 }
1009
1010                 self.best_block.block_hash().write(writer)?;
1011                 writer.write_all(&self.best_block.height().to_be_bytes())?;
1012
1013                 writer.write_all(&(self.onchain_events_awaiting_threshold_conf.len() as u64).to_be_bytes())?;
1014                 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
1015                         entry.write(writer)?;
1016                 }
1017
1018                 (self.outputs_to_watch.len() as u64).write(writer)?;
1019                 for (txid, idx_scripts) in self.outputs_to_watch.iter() {
1020                         txid.write(writer)?;
1021                         (idx_scripts.len() as u64).write(writer)?;
1022                         for (idx, script) in idx_scripts.iter() {
1023                                 idx.write(writer)?;
1024                                 script.write(writer)?;
1025                         }
1026                 }
1027                 self.onchain_tx_handler.write(writer)?;
1028
1029                 self.lockdown_from_offchain.write(writer)?;
1030                 self.holder_tx_signed.write(writer)?;
1031
1032                 write_tlv_fields!(writer, {
1033                         (1, self.funding_spend_confirmed, option),
1034                         (3, self.htlcs_resolved_on_chain, vec_type),
1035                         (5, self.pending_monitor_events, vec_type),
1036                         (7, self.funding_spend_seen, required),
1037                         (9, self.counterparty_node_id, option),
1038                         (11, self.confirmed_commitment_tx_counterparty_output, option),
1039                         (13, self.spendable_txids_confirmed, vec_type),
1040                         (15, self.counterparty_fulfilled_htlcs, required),
1041                 });
1042
1043                 Ok(())
1044         }
1045 }
1046
1047 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
1048         /// For lockorder enforcement purposes, we need to have a single site which constructs the
1049         /// `inner` mutex, otherwise cases where we lock two monitors at the same time (eg in our
1050         /// PartialEq implementation) we may decide a lockorder violation has occurred.
1051         fn from_impl(imp: ChannelMonitorImpl<Signer>) -> Self {
1052                 ChannelMonitor { inner: Mutex::new(imp) }
1053         }
1054
1055         pub(crate) fn new(secp_ctx: Secp256k1<secp256k1::All>, keys: Signer, shutdown_script: Option<Script>,
1056                           on_counterparty_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
1057                           channel_parameters: &ChannelTransactionParameters,
1058                           funding_redeemscript: Script, channel_value_satoshis: u64,
1059                           commitment_transaction_number_obscure_factor: u64,
1060                           initial_holder_commitment_tx: HolderCommitmentTransaction,
1061                           best_block: BestBlock, counterparty_node_id: PublicKey) -> ChannelMonitor<Signer> {
1062
1063                 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
1064                 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
1065                 let counterparty_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
1066
1067                 let counterparty_channel_parameters = channel_parameters.counterparty_parameters.as_ref().unwrap();
1068                 let counterparty_delayed_payment_base_key = counterparty_channel_parameters.pubkeys.delayed_payment_basepoint;
1069                 let counterparty_htlc_base_key = counterparty_channel_parameters.pubkeys.htlc_basepoint;
1070                 let counterparty_commitment_params = CounterpartyCommitmentParameters { counterparty_delayed_payment_base_key, counterparty_htlc_base_key, on_counterparty_tx_csv };
1071
1072                 let channel_keys_id = keys.channel_keys_id();
1073                 let holder_revocation_basepoint = keys.pubkeys().revocation_basepoint;
1074
1075                 // block for Rust 1.34 compat
1076                 let (holder_commitment_tx, current_holder_commitment_number) = {
1077                         let trusted_tx = initial_holder_commitment_tx.trust();
1078                         let txid = trusted_tx.txid();
1079
1080                         let tx_keys = trusted_tx.keys();
1081                         let holder_commitment_tx = HolderSignedTx {
1082                                 txid,
1083                                 revocation_key: tx_keys.revocation_key,
1084                                 a_htlc_key: tx_keys.broadcaster_htlc_key,
1085                                 b_htlc_key: tx_keys.countersignatory_htlc_key,
1086                                 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
1087                                 per_commitment_point: tx_keys.per_commitment_point,
1088                                 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
1089                                 to_self_value_sat: initial_holder_commitment_tx.to_broadcaster_value_sat(),
1090                                 feerate_per_kw: trusted_tx.feerate_per_kw(),
1091                         };
1092                         (holder_commitment_tx, trusted_tx.commitment_number())
1093                 };
1094
1095                 let onchain_tx_handler =
1096                         OnchainTxHandler::new(destination_script.clone(), keys,
1097                         channel_parameters.clone(), initial_holder_commitment_tx, secp_ctx);
1098
1099                 let mut outputs_to_watch = HashMap::new();
1100                 outputs_to_watch.insert(funding_info.0.txid, vec![(funding_info.0.index as u32, funding_info.1.clone())]);
1101
1102                 Self::from_impl(ChannelMonitorImpl {
1103                         latest_update_id: 0,
1104                         commitment_transaction_number_obscure_factor,
1105
1106                         destination_script: destination_script.clone(),
1107                         broadcasted_holder_revokable_script: None,
1108                         counterparty_payment_script,
1109                         shutdown_script,
1110
1111                         channel_keys_id,
1112                         holder_revocation_basepoint,
1113                         funding_info,
1114                         current_counterparty_commitment_txid: None,
1115                         prev_counterparty_commitment_txid: None,
1116
1117                         counterparty_commitment_params,
1118                         funding_redeemscript,
1119                         channel_value_satoshis,
1120                         their_cur_per_commitment_points: None,
1121
1122                         on_holder_tx_csv: counterparty_channel_parameters.selected_contest_delay,
1123
1124                         commitment_secrets: CounterpartyCommitmentSecrets::new(),
1125                         counterparty_claimable_outpoints: HashMap::new(),
1126                         counterparty_commitment_txn_on_chain: HashMap::new(),
1127                         counterparty_hash_commitment_number: HashMap::new(),
1128                         counterparty_fulfilled_htlcs: HashMap::new(),
1129
1130                         prev_holder_signed_commitment_tx: None,
1131                         current_holder_commitment_tx: holder_commitment_tx,
1132                         current_counterparty_commitment_number: 1 << 48,
1133                         current_holder_commitment_number,
1134
1135                         payment_preimages: HashMap::new(),
1136                         pending_monitor_events: Vec::new(),
1137                         pending_events: Vec::new(),
1138
1139                         onchain_events_awaiting_threshold_conf: Vec::new(),
1140                         outputs_to_watch,
1141
1142                         onchain_tx_handler,
1143
1144                         lockdown_from_offchain: false,
1145                         holder_tx_signed: false,
1146                         funding_spend_seen: false,
1147                         funding_spend_confirmed: None,
1148                         confirmed_commitment_tx_counterparty_output: None,
1149                         htlcs_resolved_on_chain: Vec::new(),
1150                         spendable_txids_confirmed: Vec::new(),
1151
1152                         best_block,
1153                         counterparty_node_id: Some(counterparty_node_id),
1154                 })
1155         }
1156
1157         #[cfg(test)]
1158         fn provide_secret(&self, idx: u64, secret: [u8; 32]) -> Result<(), &'static str> {
1159                 self.inner.lock().unwrap().provide_secret(idx, secret)
1160         }
1161
1162         /// Informs this monitor of the latest counterparty (ie non-broadcastable) commitment transaction.
1163         /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1164         /// possibly future revocation/preimage information) to claim outputs where possible.
1165         /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1166         pub(crate) fn provide_latest_counterparty_commitment_tx<L: Deref>(
1167                 &self,
1168                 txid: Txid,
1169                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
1170                 commitment_number: u64,
1171                 their_per_commitment_point: PublicKey,
1172                 logger: &L,
1173         ) where L::Target: Logger {
1174                 self.inner.lock().unwrap().provide_latest_counterparty_commitment_tx(
1175                         txid, htlc_outputs, commitment_number, their_per_commitment_point, logger)
1176         }
1177
1178         #[cfg(test)]
1179         fn provide_latest_holder_commitment_tx(
1180                 &self, holder_commitment_tx: HolderCommitmentTransaction,
1181                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
1182         ) -> Result<(), ()> {
1183                 self.inner.lock().unwrap().provide_latest_holder_commitment_tx(holder_commitment_tx, htlc_outputs, &Vec::new()).map_err(|_| ())
1184         }
1185
1186         /// This is used to provide payment preimage(s) out-of-band during startup without updating the
1187         /// off-chain state with a new commitment transaction.
1188         pub(crate) fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(
1189                 &self,
1190                 payment_hash: &PaymentHash,
1191                 payment_preimage: &PaymentPreimage,
1192                 broadcaster: &B,
1193                 fee_estimator: &LowerBoundedFeeEstimator<F>,
1194                 logger: &L,
1195         ) where
1196                 B::Target: BroadcasterInterface,
1197                 F::Target: FeeEstimator,
1198                 L::Target: Logger,
1199         {
1200                 self.inner.lock().unwrap().provide_payment_preimage(
1201                         payment_hash, payment_preimage, broadcaster, fee_estimator, logger)
1202         }
1203
1204         pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(
1205                 &self,
1206                 broadcaster: &B,
1207                 logger: &L,
1208         ) where
1209                 B::Target: BroadcasterInterface,
1210                 L::Target: Logger,
1211         {
1212                 self.inner.lock().unwrap().broadcast_latest_holder_commitment_txn(broadcaster, logger);
1213         }
1214
1215         /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1216         /// itself.
1217         ///
1218         /// panics if the given update is not the next update by update_id.
1219         pub fn update_monitor<B: Deref, F: Deref, L: Deref>(
1220                 &self,
1221                 updates: &ChannelMonitorUpdate,
1222                 broadcaster: &B,
1223                 fee_estimator: F,
1224                 logger: &L,
1225         ) -> Result<(), ()>
1226         where
1227                 B::Target: BroadcasterInterface,
1228                 F::Target: FeeEstimator,
1229                 L::Target: Logger,
1230         {
1231                 self.inner.lock().unwrap().update_monitor(updates, broadcaster, fee_estimator, logger)
1232         }
1233
1234         /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1235         /// ChannelMonitor.
1236         pub fn get_latest_update_id(&self) -> u64 {
1237                 self.inner.lock().unwrap().get_latest_update_id()
1238         }
1239
1240         /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1241         pub fn get_funding_txo(&self) -> (OutPoint, Script) {
1242                 self.inner.lock().unwrap().get_funding_txo().clone()
1243         }
1244
1245         /// Gets a list of txids, with their output scripts (in the order they appear in the
1246         /// transaction), which we must learn about spends of via block_connected().
1247         pub fn get_outputs_to_watch(&self) -> Vec<(Txid, Vec<(u32, Script)>)> {
1248                 self.inner.lock().unwrap().get_outputs_to_watch()
1249                         .iter().map(|(txid, outputs)| (*txid, outputs.clone())).collect()
1250         }
1251
1252         /// Loads the funding txo and outputs to watch into the given `chain::Filter` by repeatedly
1253         /// calling `chain::Filter::register_output` and `chain::Filter::register_tx` until all outputs
1254         /// have been registered.
1255         pub fn load_outputs_to_watch<F: Deref>(&self, filter: &F) where F::Target: chain::Filter {
1256                 let lock = self.inner.lock().unwrap();
1257                 filter.register_tx(&lock.get_funding_txo().0.txid, &lock.get_funding_txo().1);
1258                 for (txid, outputs) in lock.get_outputs_to_watch().iter() {
1259                         for (index, script_pubkey) in outputs.iter() {
1260                                 assert!(*index <= u16::max_value() as u32);
1261                                 filter.register_output(WatchedOutput {
1262                                         block_hash: None,
1263                                         outpoint: OutPoint { txid: *txid, index: *index as u16 },
1264                                         script_pubkey: script_pubkey.clone(),
1265                                 });
1266                         }
1267                 }
1268         }
1269
1270         /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1271         /// ChannelManager via [`chain::Watch::release_pending_monitor_events`].
1272         pub fn get_and_clear_pending_monitor_events(&self) -> Vec<MonitorEvent> {
1273                 self.inner.lock().unwrap().get_and_clear_pending_monitor_events()
1274         }
1275
1276         /// Gets the list of pending events which were generated by previous actions, clearing the list
1277         /// in the process.
1278         ///
1279         /// This is called by the [`EventsProvider::process_pending_events`] implementation for
1280         /// [`ChainMonitor`].
1281         ///
1282         /// [`EventsProvider::process_pending_events`]: crate::util::events::EventsProvider::process_pending_events
1283         /// [`ChainMonitor`]: crate::chain::chainmonitor::ChainMonitor
1284         pub fn get_and_clear_pending_events(&self) -> Vec<Event> {
1285                 self.inner.lock().unwrap().get_and_clear_pending_events()
1286         }
1287
1288         pub(crate) fn get_min_seen_secret(&self) -> u64 {
1289                 self.inner.lock().unwrap().get_min_seen_secret()
1290         }
1291
1292         pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1293                 self.inner.lock().unwrap().get_cur_counterparty_commitment_number()
1294         }
1295
1296         pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
1297                 self.inner.lock().unwrap().get_cur_holder_commitment_number()
1298         }
1299
1300         /// Gets the `node_id` of the counterparty for this channel.
1301         ///
1302         /// Will be `None` for channels constructed on LDK versions prior to 0.0.110 and always `Some`
1303         /// otherwise.
1304         pub fn get_counterparty_node_id(&self) -> Option<PublicKey> {
1305                 self.inner.lock().unwrap().counterparty_node_id
1306         }
1307
1308         /// Used by ChannelManager deserialization to broadcast the latest holder state if its copy of
1309         /// the Channel was out-of-date.
1310         ///
1311         /// You may also use this to broadcast the latest local commitment transaction, either because
1312         /// a monitor update failed with [`ChannelMonitorUpdateStatus::PermanentFailure`] or because we've
1313         /// fallen behind (i.e. we've received proof that our counterparty side knows a revocation
1314         /// secret we gave them that they shouldn't know).
1315         ///
1316         /// Broadcasting these transactions in the second case is UNSAFE, as they allow counterparty
1317         /// side to punish you. Nevertheless you may want to broadcast them if counterparty doesn't
1318         /// close channel with their commitment transaction after a substantial amount of time. Best
1319         /// may be to contact the other node operator out-of-band to coordinate other options available
1320         /// to you. In any-case, the choice is up to you.
1321         ///
1322         /// [`ChannelMonitorUpdateStatus::PermanentFailure`]: super::ChannelMonitorUpdateStatus::PermanentFailure
1323         pub fn get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1324         where L::Target: Logger {
1325                 self.inner.lock().unwrap().get_latest_holder_commitment_txn(logger)
1326         }
1327
1328         /// Unsafe test-only version of get_latest_holder_commitment_txn used by our test framework
1329         /// to bypass HolderCommitmentTransaction state update lockdown after signature and generate
1330         /// revoked commitment transaction.
1331         #[cfg(any(test, feature = "unsafe_revoked_tx_signing"))]
1332         pub fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1333         where L::Target: Logger {
1334                 self.inner.lock().unwrap().unsafe_get_latest_holder_commitment_txn(logger)
1335         }
1336
1337         /// Processes transactions in a newly connected block, which may result in any of the following:
1338         /// - update the monitor's state against resolved HTLCs
1339         /// - punish the counterparty in the case of seeing a revoked commitment transaction
1340         /// - force close the channel and claim/timeout incoming/outgoing HTLCs if near expiration
1341         /// - detect settled outputs for later spending
1342         /// - schedule and bump any in-flight claims
1343         ///
1344         /// Returns any new outputs to watch from `txdata`; after called, these are also included in
1345         /// [`get_outputs_to_watch`].
1346         ///
1347         /// [`get_outputs_to_watch`]: #method.get_outputs_to_watch
1348         pub fn block_connected<B: Deref, F: Deref, L: Deref>(
1349                 &self,
1350                 header: &BlockHeader,
1351                 txdata: &TransactionData,
1352                 height: u32,
1353                 broadcaster: B,
1354                 fee_estimator: F,
1355                 logger: L,
1356         ) -> Vec<TransactionOutputs>
1357         where
1358                 B::Target: BroadcasterInterface,
1359                 F::Target: FeeEstimator,
1360                 L::Target: Logger,
1361         {
1362                 self.inner.lock().unwrap().block_connected(
1363                         header, txdata, height, broadcaster, fee_estimator, logger)
1364         }
1365
1366         /// Determines if the disconnected block contained any transactions of interest and updates
1367         /// appropriately.
1368         pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(
1369                 &self,
1370                 header: &BlockHeader,
1371                 height: u32,
1372                 broadcaster: B,
1373                 fee_estimator: F,
1374                 logger: L,
1375         ) where
1376                 B::Target: BroadcasterInterface,
1377                 F::Target: FeeEstimator,
1378                 L::Target: Logger,
1379         {
1380                 self.inner.lock().unwrap().block_disconnected(
1381                         header, height, broadcaster, fee_estimator, logger)
1382         }
1383
1384         /// Processes transactions confirmed in a block with the given header and height, returning new
1385         /// outputs to watch. See [`block_connected`] for details.
1386         ///
1387         /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
1388         /// blocks. See [`chain::Confirm`] for calling expectations.
1389         ///
1390         /// [`block_connected`]: Self::block_connected
1391         pub fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
1392                 &self,
1393                 header: &BlockHeader,
1394                 txdata: &TransactionData,
1395                 height: u32,
1396                 broadcaster: B,
1397                 fee_estimator: F,
1398                 logger: L,
1399         ) -> Vec<TransactionOutputs>
1400         where
1401                 B::Target: BroadcasterInterface,
1402                 F::Target: FeeEstimator,
1403                 L::Target: Logger,
1404         {
1405                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1406                 self.inner.lock().unwrap().transactions_confirmed(
1407                         header, txdata, height, broadcaster, &bounded_fee_estimator, logger)
1408         }
1409
1410         /// Processes a transaction that was reorganized out of the chain.
1411         ///
1412         /// Used instead of [`block_disconnected`] by clients that are notified of transactions rather
1413         /// than blocks. See [`chain::Confirm`] for calling expectations.
1414         ///
1415         /// [`block_disconnected`]: Self::block_disconnected
1416         pub fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
1417                 &self,
1418                 txid: &Txid,
1419                 broadcaster: B,
1420                 fee_estimator: F,
1421                 logger: L,
1422         ) where
1423                 B::Target: BroadcasterInterface,
1424                 F::Target: FeeEstimator,
1425                 L::Target: Logger,
1426         {
1427                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1428                 self.inner.lock().unwrap().transaction_unconfirmed(
1429                         txid, broadcaster, &bounded_fee_estimator, logger);
1430         }
1431
1432         /// Updates the monitor with the current best chain tip, returning new outputs to watch. See
1433         /// [`block_connected`] for details.
1434         ///
1435         /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
1436         /// blocks. See [`chain::Confirm`] for calling expectations.
1437         ///
1438         /// [`block_connected`]: Self::block_connected
1439         pub fn best_block_updated<B: Deref, F: Deref, L: Deref>(
1440                 &self,
1441                 header: &BlockHeader,
1442                 height: u32,
1443                 broadcaster: B,
1444                 fee_estimator: F,
1445                 logger: L,
1446         ) -> Vec<TransactionOutputs>
1447         where
1448                 B::Target: BroadcasterInterface,
1449                 F::Target: FeeEstimator,
1450                 L::Target: Logger,
1451         {
1452                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1453                 self.inner.lock().unwrap().best_block_updated(
1454                         header, height, broadcaster, &bounded_fee_estimator, logger)
1455         }
1456
1457         /// Returns the set of txids that should be monitored for re-organization out of the chain.
1458         pub fn get_relevant_txids(&self) -> Vec<(Txid, Option<BlockHash>)> {
1459                 let inner = self.inner.lock().unwrap();
1460                 let mut txids: Vec<(Txid, Option<BlockHash>)> = inner.onchain_events_awaiting_threshold_conf
1461                         .iter()
1462                         .map(|entry| (entry.txid, entry.block_hash))
1463                         .chain(inner.onchain_tx_handler.get_relevant_txids().into_iter())
1464                         .collect();
1465                 txids.sort_unstable();
1466                 txids.dedup();
1467                 txids
1468         }
1469
1470         /// Gets the latest best block which was connected either via the [`chain::Listen`] or
1471         /// [`chain::Confirm`] interfaces.
1472         pub fn current_best_block(&self) -> BestBlock {
1473                 self.inner.lock().unwrap().best_block.clone()
1474         }
1475 }
1476
1477 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
1478         /// Helper for get_claimable_balances which does the work for an individual HTLC, generating up
1479         /// to one `Balance` for the HTLC.
1480         fn get_htlc_balance(&self, htlc: &HTLCOutputInCommitment, holder_commitment: bool,
1481                 counterparty_revoked_commitment: bool, confirmed_txid: Option<Txid>)
1482         -> Option<Balance> {
1483                 let htlc_commitment_tx_output_idx =
1484                         if let Some(v) = htlc.transaction_output_index { v } else { return None; };
1485
1486                 let mut htlc_spend_txid_opt = None;
1487                 let mut htlc_spend_tx_opt = None;
1488                 let mut holder_timeout_spend_pending = None;
1489                 let mut htlc_spend_pending = None;
1490                 let mut holder_delayed_output_pending = None;
1491                 for event in self.onchain_events_awaiting_threshold_conf.iter() {
1492                         match event.event {
1493                                 OnchainEvent::HTLCUpdate { commitment_tx_output_idx, htlc_value_satoshis, .. }
1494                                 if commitment_tx_output_idx == Some(htlc_commitment_tx_output_idx) => {
1495                                         debug_assert!(htlc_spend_txid_opt.is_none());
1496                                         htlc_spend_txid_opt = Some(&event.txid);
1497                                         debug_assert!(htlc_spend_tx_opt.is_none());
1498                                         htlc_spend_tx_opt = event.transaction.as_ref();
1499                                         debug_assert!(holder_timeout_spend_pending.is_none());
1500                                         debug_assert_eq!(htlc_value_satoshis.unwrap(), htlc.amount_msat / 1000);
1501                                         holder_timeout_spend_pending = Some(event.confirmation_threshold());
1502                                 },
1503                                 OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, preimage, .. }
1504                                 if commitment_tx_output_idx == htlc_commitment_tx_output_idx => {
1505                                         debug_assert!(htlc_spend_txid_opt.is_none());
1506                                         htlc_spend_txid_opt = Some(&event.txid);
1507                                         debug_assert!(htlc_spend_tx_opt.is_none());
1508                                         htlc_spend_tx_opt = event.transaction.as_ref();
1509                                         debug_assert!(htlc_spend_pending.is_none());
1510                                         htlc_spend_pending = Some((event.confirmation_threshold(), preimage.is_some()));
1511                                 },
1512                                 OnchainEvent::MaturingOutput {
1513                                         descriptor: SpendableOutputDescriptor::DelayedPaymentOutput(ref descriptor) }
1514                                 if descriptor.outpoint.index as u32 == htlc_commitment_tx_output_idx => {
1515                                         debug_assert!(holder_delayed_output_pending.is_none());
1516                                         holder_delayed_output_pending = Some(event.confirmation_threshold());
1517                                 },
1518                                 _ => {},
1519                         }
1520                 }
1521                 let htlc_resolved = self.htlcs_resolved_on_chain.iter()
1522                         .find(|v| if v.commitment_tx_output_idx == Some(htlc_commitment_tx_output_idx) {
1523                                 debug_assert!(htlc_spend_txid_opt.is_none());
1524                                 htlc_spend_txid_opt = v.resolving_txid.as_ref();
1525                                 debug_assert!(htlc_spend_tx_opt.is_none());
1526                                 htlc_spend_tx_opt = v.resolving_tx.as_ref();
1527                                 true
1528                         } else { false });
1529                 debug_assert!(holder_timeout_spend_pending.is_some() as u8 + htlc_spend_pending.is_some() as u8 + htlc_resolved.is_some() as u8 <= 1);
1530
1531                 let htlc_commitment_outpoint = BitcoinOutPoint::new(confirmed_txid.unwrap(), htlc_commitment_tx_output_idx);
1532                 let htlc_output_to_spend =
1533                         if let Some(txid) = htlc_spend_txid_opt {
1534                                 // Because HTLC transactions either only have 1 input and 1 output (pre-anchors) or
1535                                 // are signed with SIGHASH_SINGLE|ANYONECANPAY under BIP-0143 (post-anchors), we can
1536                                 // locate the correct output by ensuring its adjacent input spends the HTLC output
1537                                 // in the commitment.
1538                                 if let Some(ref tx) = htlc_spend_tx_opt {
1539                                         let htlc_input_idx_opt = tx.input.iter().enumerate()
1540                                                 .find(|(_, input)| input.previous_output == htlc_commitment_outpoint)
1541                                                 .map(|(idx, _)| idx as u32);
1542                                         debug_assert!(htlc_input_idx_opt.is_some());
1543                                         BitcoinOutPoint::new(*txid, htlc_input_idx_opt.unwrap_or(0))
1544                                 } else {
1545                                         debug_assert!(!self.onchain_tx_handler.opt_anchors());
1546                                         BitcoinOutPoint::new(*txid, 0)
1547                                 }
1548                         } else {
1549                                 htlc_commitment_outpoint
1550                         };
1551                 let htlc_output_spend_pending = self.onchain_tx_handler.is_output_spend_pending(&htlc_output_to_spend);
1552
1553                 if let Some(conf_thresh) = holder_delayed_output_pending {
1554                         debug_assert!(holder_commitment);
1555                         return Some(Balance::ClaimableAwaitingConfirmations {
1556                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1557                                 confirmation_height: conf_thresh,
1558                         });
1559                 } else if htlc_resolved.is_some() && !htlc_output_spend_pending {
1560                         // Funding transaction spends should be fully confirmed by the time any
1561                         // HTLC transactions are resolved, unless we're talking about a holder
1562                         // commitment tx, whose resolution is delayed until the CSV timeout is
1563                         // reached, even though HTLCs may be resolved after only
1564                         // ANTI_REORG_DELAY confirmations.
1565                         debug_assert!(holder_commitment || self.funding_spend_confirmed.is_some());
1566                 } else if counterparty_revoked_commitment {
1567                         let htlc_output_claim_pending = self.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1568                                 if let OnchainEvent::MaturingOutput {
1569                                         descriptor: SpendableOutputDescriptor::StaticOutput { .. }
1570                                 } = &event.event {
1571                                         if event.transaction.as_ref().map(|tx| tx.input.iter().any(|inp| {
1572                                                 if let Some(htlc_spend_txid) = htlc_spend_txid_opt {
1573                                                         tx.txid() == *htlc_spend_txid || inp.previous_output.txid == *htlc_spend_txid
1574                                                 } else {
1575                                                         Some(inp.previous_output.txid) == confirmed_txid &&
1576                                                                 inp.previous_output.vout == htlc_commitment_tx_output_idx
1577                                                 }
1578                                         })).unwrap_or(false) {
1579                                                 Some(())
1580                                         } else { None }
1581                                 } else { None }
1582                         });
1583                         if htlc_output_claim_pending.is_some() {
1584                                 // We already push `Balance`s onto the `res` list for every
1585                                 // `StaticOutput` in a `MaturingOutput` in the revoked
1586                                 // counterparty commitment transaction case generally, so don't
1587                                 // need to do so again here.
1588                         } else {
1589                                 debug_assert!(holder_timeout_spend_pending.is_none(),
1590                                         "HTLCUpdate OnchainEvents should never appear for preimage claims");
1591                                 debug_assert!(!htlc.offered || htlc_spend_pending.is_none() || !htlc_spend_pending.unwrap().1,
1592                                         "We don't (currently) generate preimage claims against revoked outputs, where did you get one?!");
1593                                 return Some(Balance::CounterpartyRevokedOutputClaimable {
1594                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1595                                 });
1596                         }
1597                 } else if htlc.offered == holder_commitment {
1598                         // If the payment was outbound, check if there's an HTLCUpdate
1599                         // indicating we have spent this HTLC with a timeout, claiming it back
1600                         // and awaiting confirmations on it.
1601                         if let Some(conf_thresh) = holder_timeout_spend_pending {
1602                                 return Some(Balance::ClaimableAwaitingConfirmations {
1603                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1604                                         confirmation_height: conf_thresh,
1605                                 });
1606                         } else {
1607                                 return Some(Balance::MaybeTimeoutClaimableHTLC {
1608                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1609                                         claimable_height: htlc.cltv_expiry,
1610                                 });
1611                         }
1612                 } else if self.payment_preimages.get(&htlc.payment_hash).is_some() {
1613                         // Otherwise (the payment was inbound), only expose it as claimable if
1614                         // we know the preimage.
1615                         // Note that if there is a pending claim, but it did not use the
1616                         // preimage, we lost funds to our counterparty! We will then continue
1617                         // to show it as ContentiousClaimable until ANTI_REORG_DELAY.
1618                         debug_assert!(holder_timeout_spend_pending.is_none());
1619                         if let Some((conf_thresh, true)) = htlc_spend_pending {
1620                                 return Some(Balance::ClaimableAwaitingConfirmations {
1621                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1622                                         confirmation_height: conf_thresh,
1623                                 });
1624                         } else {
1625                                 return Some(Balance::ContentiousClaimable {
1626                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1627                                         timeout_height: htlc.cltv_expiry,
1628                                 });
1629                         }
1630                 } else if htlc_resolved.is_none() {
1631                         return Some(Balance::MaybePreimageClaimableHTLC {
1632                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1633                                 expiry_height: htlc.cltv_expiry,
1634                         });
1635                 }
1636                 None
1637         }
1638 }
1639
1640 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
1641         /// Gets the balances in this channel which are either claimable by us if we were to
1642         /// force-close the channel now or which are claimable on-chain (possibly awaiting
1643         /// confirmation).
1644         ///
1645         /// Any balances in the channel which are available on-chain (excluding on-chain fees) are
1646         /// included here until an [`Event::SpendableOutputs`] event has been generated for the
1647         /// balance, or until our counterparty has claimed the balance and accrued several
1648         /// confirmations on the claim transaction.
1649         ///
1650         /// Note that for `ChannelMonitors` which track a channel which went on-chain with versions of
1651         /// LDK prior to 0.0.111, balances may not be fully captured if our counterparty broadcasted
1652         /// a revoked state.
1653         ///
1654         /// See [`Balance`] for additional details on the types of claimable balances which
1655         /// may be returned here and their meanings.
1656         pub fn get_claimable_balances(&self) -> Vec<Balance> {
1657                 let mut res = Vec::new();
1658                 let us = self.inner.lock().unwrap();
1659
1660                 let mut confirmed_txid = us.funding_spend_confirmed;
1661                 let mut confirmed_counterparty_output = us.confirmed_commitment_tx_counterparty_output;
1662                 let mut pending_commitment_tx_conf_thresh = None;
1663                 let funding_spend_pending = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1664                         if let OnchainEvent::FundingSpendConfirmation { commitment_tx_to_counterparty_output, .. } =
1665                                 event.event
1666                         {
1667                                 confirmed_counterparty_output = commitment_tx_to_counterparty_output;
1668                                 Some((event.txid, event.confirmation_threshold()))
1669                         } else { None }
1670                 });
1671                 if let Some((txid, conf_thresh)) = funding_spend_pending {
1672                         debug_assert!(us.funding_spend_confirmed.is_none(),
1673                                 "We have a pending funding spend awaiting anti-reorg confirmation, we can't have confirmed it already!");
1674                         confirmed_txid = Some(txid);
1675                         pending_commitment_tx_conf_thresh = Some(conf_thresh);
1676                 }
1677
1678                 macro_rules! walk_htlcs {
1679                         ($holder_commitment: expr, $counterparty_revoked_commitment: expr, $htlc_iter: expr) => {
1680                                 for htlc in $htlc_iter {
1681                                         if htlc.transaction_output_index.is_some() {
1682
1683                                                 if let Some(bal) = us.get_htlc_balance(htlc, $holder_commitment, $counterparty_revoked_commitment, confirmed_txid) {
1684                                                         res.push(bal);
1685                                                 }
1686                                         }
1687                                 }
1688                         }
1689                 }
1690
1691                 if let Some(txid) = confirmed_txid {
1692                         let mut found_commitment_tx = false;
1693                         if let Some(counterparty_tx_htlcs) = us.counterparty_claimable_outpoints.get(&txid) {
1694                                 // First look for the to_remote output back to us.
1695                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1696                                         if let Some(value) = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1697                                                 if let OnchainEvent::MaturingOutput {
1698                                                         descriptor: SpendableOutputDescriptor::StaticPaymentOutput(descriptor)
1699                                                 } = &event.event {
1700                                                         Some(descriptor.output.value)
1701                                                 } else { None }
1702                                         }) {
1703                                                 res.push(Balance::ClaimableAwaitingConfirmations {
1704                                                         claimable_amount_satoshis: value,
1705                                                         confirmation_height: conf_thresh,
1706                                                 });
1707                                         } else {
1708                                                 // If a counterparty commitment transaction is awaiting confirmation, we
1709                                                 // should either have a StaticPaymentOutput MaturingOutput event awaiting
1710                                                 // confirmation with the same height or have never met our dust amount.
1711                                         }
1712                                 }
1713                                 if Some(txid) == us.current_counterparty_commitment_txid || Some(txid) == us.prev_counterparty_commitment_txid {
1714                                         walk_htlcs!(false, false, counterparty_tx_htlcs.iter().map(|(a, _)| a));
1715                                 } else {
1716                                         walk_htlcs!(false, true, counterparty_tx_htlcs.iter().map(|(a, _)| a));
1717                                         // The counterparty broadcasted a revoked state!
1718                                         // Look for any StaticOutputs first, generating claimable balances for those.
1719                                         // If any match the confirmed counterparty revoked to_self output, skip
1720                                         // generating a CounterpartyRevokedOutputClaimable.
1721                                         let mut spent_counterparty_output = false;
1722                                         for event in us.onchain_events_awaiting_threshold_conf.iter() {
1723                                                 if let OnchainEvent::MaturingOutput {
1724                                                         descriptor: SpendableOutputDescriptor::StaticOutput { output, .. }
1725                                                 } = &event.event {
1726                                                         res.push(Balance::ClaimableAwaitingConfirmations {
1727                                                                 claimable_amount_satoshis: output.value,
1728                                                                 confirmation_height: event.confirmation_threshold(),
1729                                                         });
1730                                                         if let Some(confirmed_to_self_idx) = confirmed_counterparty_output.map(|(idx, _)| idx) {
1731                                                                 if event.transaction.as_ref().map(|tx|
1732                                                                         tx.input.iter().any(|inp| inp.previous_output.vout == confirmed_to_self_idx)
1733                                                                 ).unwrap_or(false) {
1734                                                                         spent_counterparty_output = true;
1735                                                                 }
1736                                                         }
1737                                                 }
1738                                         }
1739
1740                                         if spent_counterparty_output {
1741                                         } else if let Some((confirmed_to_self_idx, amt)) = confirmed_counterparty_output {
1742                                                 let output_spendable = us.onchain_tx_handler
1743                                                         .is_output_spend_pending(&BitcoinOutPoint::new(txid, confirmed_to_self_idx));
1744                                                 if output_spendable {
1745                                                         res.push(Balance::CounterpartyRevokedOutputClaimable {
1746                                                                 claimable_amount_satoshis: amt,
1747                                                         });
1748                                                 }
1749                                         } else {
1750                                                 // Counterparty output is missing, either it was broadcasted on a
1751                                                 // previous version of LDK or the counterparty hadn't met dust.
1752                                         }
1753                                 }
1754                                 found_commitment_tx = true;
1755                         } else if txid == us.current_holder_commitment_tx.txid {
1756                                 walk_htlcs!(true, false, us.current_holder_commitment_tx.htlc_outputs.iter().map(|(a, _, _)| a));
1757                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1758                                         res.push(Balance::ClaimableAwaitingConfirmations {
1759                                                 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
1760                                                 confirmation_height: conf_thresh,
1761                                         });
1762                                 }
1763                                 found_commitment_tx = true;
1764                         } else if let Some(prev_commitment) = &us.prev_holder_signed_commitment_tx {
1765                                 if txid == prev_commitment.txid {
1766                                         walk_htlcs!(true, false, prev_commitment.htlc_outputs.iter().map(|(a, _, _)| a));
1767                                         if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1768                                                 res.push(Balance::ClaimableAwaitingConfirmations {
1769                                                         claimable_amount_satoshis: prev_commitment.to_self_value_sat,
1770                                                         confirmation_height: conf_thresh,
1771                                                 });
1772                                         }
1773                                         found_commitment_tx = true;
1774                                 }
1775                         }
1776                         if !found_commitment_tx {
1777                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1778                                         // We blindly assume this is a cooperative close transaction here, and that
1779                                         // neither us nor our counterparty misbehaved. At worst we've under-estimated
1780                                         // the amount we can claim as we'll punish a misbehaving counterparty.
1781                                         res.push(Balance::ClaimableAwaitingConfirmations {
1782                                                 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
1783                                                 confirmation_height: conf_thresh,
1784                                         });
1785                                 }
1786                         }
1787                 } else {
1788                         let mut claimable_inbound_htlc_value_sat = 0;
1789                         for (htlc, _, _) in us.current_holder_commitment_tx.htlc_outputs.iter() {
1790                                 if htlc.transaction_output_index.is_none() { continue; }
1791                                 if htlc.offered {
1792                                         res.push(Balance::MaybeTimeoutClaimableHTLC {
1793                                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1794                                                 claimable_height: htlc.cltv_expiry,
1795                                         });
1796                                 } else if us.payment_preimages.get(&htlc.payment_hash).is_some() {
1797                                         claimable_inbound_htlc_value_sat += htlc.amount_msat / 1000;
1798                                 } else {
1799                                         // As long as the HTLC is still in our latest commitment state, treat
1800                                         // it as potentially claimable, even if it has long-since expired.
1801                                         res.push(Balance::MaybePreimageClaimableHTLC {
1802                                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1803                                                 expiry_height: htlc.cltv_expiry,
1804                                         });
1805                                 }
1806                         }
1807                         res.push(Balance::ClaimableOnChannelClose {
1808                                 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat + claimable_inbound_htlc_value_sat,
1809                         });
1810                 }
1811
1812                 res
1813         }
1814
1815         /// Gets the set of outbound HTLCs which can be (or have been) resolved by this
1816         /// `ChannelMonitor`. This is used to determine if an HTLC was removed from the channel prior
1817         /// to the `ChannelManager` having been persisted.
1818         ///
1819         /// This is similar to [`Self::get_pending_or_resolved_outbound_htlcs`] except it includes
1820         /// HTLCs which were resolved on-chain (i.e. where the final HTLC resolution was done by an
1821         /// event from this `ChannelMonitor`).
1822         pub(crate) fn get_all_current_outbound_htlcs(&self) -> HashMap<HTLCSource, (HTLCOutputInCommitment, Option<PaymentPreimage>)> {
1823                 let mut res = HashMap::new();
1824                 // Just examine the available counterparty commitment transactions. See docs on
1825                 // `fail_unbroadcast_htlcs`, below, for justification.
1826                 let us = self.inner.lock().unwrap();
1827                 macro_rules! walk_counterparty_commitment {
1828                         ($txid: expr) => {
1829                                 if let Some(ref latest_outpoints) = us.counterparty_claimable_outpoints.get($txid) {
1830                                         for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1831                                                 if let &Some(ref source) = source_option {
1832                                                         res.insert((**source).clone(), (htlc.clone(),
1833                                                                 us.counterparty_fulfilled_htlcs.get(&SentHTLCId::from_source(source)).cloned()));
1834                                                 }
1835                                         }
1836                                 }
1837                         }
1838                 }
1839                 if let Some(ref txid) = us.current_counterparty_commitment_txid {
1840                         walk_counterparty_commitment!(txid);
1841                 }
1842                 if let Some(ref txid) = us.prev_counterparty_commitment_txid {
1843                         walk_counterparty_commitment!(txid);
1844                 }
1845                 res
1846         }
1847
1848         /// Gets the set of outbound HTLCs which are pending resolution in this channel or which were
1849         /// resolved with a preimage from our counterparty.
1850         ///
1851         /// This is used to reconstruct pending outbound payments on restart in the ChannelManager.
1852         ///
1853         /// Currently, the preimage is unused, however if it is present in the relevant internal state
1854         /// an HTLC is always included even if it has been resolved.
1855         pub(crate) fn get_pending_or_resolved_outbound_htlcs(&self) -> HashMap<HTLCSource, (HTLCOutputInCommitment, Option<PaymentPreimage>)> {
1856                 let us = self.inner.lock().unwrap();
1857                 // We're only concerned with the confirmation count of HTLC transactions, and don't
1858                 // actually care how many confirmations a commitment transaction may or may not have. Thus,
1859                 // we look for either a FundingSpendConfirmation event or a funding_spend_confirmed.
1860                 let confirmed_txid = us.funding_spend_confirmed.or_else(|| {
1861                         us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1862                                 if let OnchainEvent::FundingSpendConfirmation { .. } = event.event {
1863                                         Some(event.txid)
1864                                 } else { None }
1865                         })
1866                 });
1867
1868                 if confirmed_txid.is_none() {
1869                         // If we have not seen a commitment transaction on-chain (ie the channel is not yet
1870                         // closed), just get the full set.
1871                         mem::drop(us);
1872                         return self.get_all_current_outbound_htlcs();
1873                 }
1874
1875                 let mut res = HashMap::new();
1876                 macro_rules! walk_htlcs {
1877                         ($holder_commitment: expr, $htlc_iter: expr) => {
1878                                 for (htlc, source) in $htlc_iter {
1879                                         if us.htlcs_resolved_on_chain.iter().any(|v| v.commitment_tx_output_idx == htlc.transaction_output_index) {
1880                                                 // We should assert that funding_spend_confirmed is_some() here, but we
1881                                                 // have some unit tests which violate HTLC transaction CSVs entirely and
1882                                                 // would fail.
1883                                                 // TODO: Once tests all connect transactions at consensus-valid times, we
1884                                                 // should assert here like we do in `get_claimable_balances`.
1885                                         } else if htlc.offered == $holder_commitment {
1886                                                 // If the payment was outbound, check if there's an HTLCUpdate
1887                                                 // indicating we have spent this HTLC with a timeout, claiming it back
1888                                                 // and awaiting confirmations on it.
1889                                                 let htlc_update_confd = us.onchain_events_awaiting_threshold_conf.iter().any(|event| {
1890                                                         if let OnchainEvent::HTLCUpdate { commitment_tx_output_idx: Some(commitment_tx_output_idx), .. } = event.event {
1891                                                                 // If the HTLC was timed out, we wait for ANTI_REORG_DELAY blocks
1892                                                                 // before considering it "no longer pending" - this matches when we
1893                                                                 // provide the ChannelManager an HTLC failure event.
1894                                                                 Some(commitment_tx_output_idx) == htlc.transaction_output_index &&
1895                                                                         us.best_block.height() >= event.height + ANTI_REORG_DELAY - 1
1896                                                         } else if let OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, .. } = event.event {
1897                                                                 // If the HTLC was fulfilled with a preimage, we consider the HTLC
1898                                                                 // immediately non-pending, matching when we provide ChannelManager
1899                                                                 // the preimage.
1900                                                                 Some(commitment_tx_output_idx) == htlc.transaction_output_index
1901                                                         } else { false }
1902                                                 });
1903                                                 let counterparty_resolved_preimage_opt =
1904                                                         us.counterparty_fulfilled_htlcs.get(&SentHTLCId::from_source(source)).cloned();
1905                                                 if !htlc_update_confd || counterparty_resolved_preimage_opt.is_some() {
1906                                                         res.insert(source.clone(), (htlc.clone(), counterparty_resolved_preimage_opt));
1907                                                 }
1908                                         }
1909                                 }
1910                         }
1911                 }
1912
1913                 let txid = confirmed_txid.unwrap();
1914                 if Some(txid) == us.current_counterparty_commitment_txid || Some(txid) == us.prev_counterparty_commitment_txid {
1915                         walk_htlcs!(false, us.counterparty_claimable_outpoints.get(&txid).unwrap().iter().filter_map(|(a, b)| {
1916                                 if let &Some(ref source) = b {
1917                                         Some((a, &**source))
1918                                 } else { None }
1919                         }));
1920                 } else if txid == us.current_holder_commitment_tx.txid {
1921                         walk_htlcs!(true, us.current_holder_commitment_tx.htlc_outputs.iter().filter_map(|(a, _, c)| {
1922                                 if let Some(source) = c { Some((a, source)) } else { None }
1923                         }));
1924                 } else if let Some(prev_commitment) = &us.prev_holder_signed_commitment_tx {
1925                         if txid == prev_commitment.txid {
1926                                 walk_htlcs!(true, prev_commitment.htlc_outputs.iter().filter_map(|(a, _, c)| {
1927                                         if let Some(source) = c { Some((a, source)) } else { None }
1928                                 }));
1929                         }
1930                 }
1931
1932                 res
1933         }
1934
1935         pub(crate) fn get_stored_preimages(&self) -> HashMap<PaymentHash, PaymentPreimage> {
1936                 self.inner.lock().unwrap().payment_preimages.clone()
1937         }
1938 }
1939
1940 /// Compares a broadcasted commitment transaction's HTLCs with those in the latest state,
1941 /// failing any HTLCs which didn't make it into the broadcasted commitment transaction back
1942 /// after ANTI_REORG_DELAY blocks.
1943 ///
1944 /// We always compare against the set of HTLCs in counterparty commitment transactions, as those
1945 /// are the commitment transactions which are generated by us. The off-chain state machine in
1946 /// `Channel` will automatically resolve any HTLCs which were never included in a commitment
1947 /// transaction when it detects channel closure, but it is up to us to ensure any HTLCs which were
1948 /// included in a remote commitment transaction are failed back if they are not present in the
1949 /// broadcasted commitment transaction.
1950 ///
1951 /// Specifically, the removal process for HTLCs in `Channel` is always based on the counterparty
1952 /// sending a `revoke_and_ack`, which causes us to clear `prev_counterparty_commitment_txid`. Thus,
1953 /// as long as we examine both the current counterparty commitment transaction and, if it hasn't
1954 /// been revoked yet, the previous one, we we will never "forget" to resolve an HTLC.
1955 macro_rules! fail_unbroadcast_htlcs {
1956         ($self: expr, $commitment_tx_type: expr, $commitment_txid_confirmed: expr, $commitment_tx_confirmed: expr,
1957          $commitment_tx_conf_height: expr, $commitment_tx_conf_hash: expr, $confirmed_htlcs_list: expr, $logger: expr) => { {
1958                 debug_assert_eq!($commitment_tx_confirmed.txid(), $commitment_txid_confirmed);
1959
1960                 macro_rules! check_htlc_fails {
1961                         ($txid: expr, $commitment_tx: expr) => {
1962                                 if let Some(ref latest_outpoints) = $self.counterparty_claimable_outpoints.get($txid) {
1963                                         for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1964                                                 if let &Some(ref source) = source_option {
1965                                                         // Check if the HTLC is present in the commitment transaction that was
1966                                                         // broadcast, but not if it was below the dust limit, which we should
1967                                                         // fail backwards immediately as there is no way for us to learn the
1968                                                         // payment_preimage.
1969                                                         // Note that if the dust limit were allowed to change between
1970                                                         // commitment transactions we'd want to be check whether *any*
1971                                                         // broadcastable commitment transaction has the HTLC in it, but it
1972                                                         // cannot currently change after channel initialization, so we don't
1973                                                         // need to here.
1974                                                         let confirmed_htlcs_iter: &mut Iterator<Item = (&HTLCOutputInCommitment, Option<&HTLCSource>)> = &mut $confirmed_htlcs_list;
1975
1976                                                         let mut matched_htlc = false;
1977                                                         for (ref broadcast_htlc, ref broadcast_source) in confirmed_htlcs_iter {
1978                                                                 if broadcast_htlc.transaction_output_index.is_some() &&
1979                                                                         (Some(&**source) == *broadcast_source ||
1980                                                                          (broadcast_source.is_none() &&
1981                                                                           broadcast_htlc.payment_hash == htlc.payment_hash &&
1982                                                                           broadcast_htlc.amount_msat == htlc.amount_msat)) {
1983                                                                         matched_htlc = true;
1984                                                                         break;
1985                                                                 }
1986                                                         }
1987                                                         if matched_htlc { continue; }
1988                                                         if $self.counterparty_fulfilled_htlcs.get(&SentHTLCId::from_source(source)).is_some() {
1989                                                                 continue;
1990                                                         }
1991                                                         $self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
1992                                                                 if entry.height != $commitment_tx_conf_height { return true; }
1993                                                                 match entry.event {
1994                                                                         OnchainEvent::HTLCUpdate { source: ref update_source, .. } => {
1995                                                                                 *update_source != **source
1996                                                                         },
1997                                                                         _ => true,
1998                                                                 }
1999                                                         });
2000                                                         let entry = OnchainEventEntry {
2001                                                                 txid: $commitment_txid_confirmed,
2002                                                                 transaction: Some($commitment_tx_confirmed.clone()),
2003                                                                 height: $commitment_tx_conf_height,
2004                                                                 block_hash: Some(*$commitment_tx_conf_hash),
2005                                                                 event: OnchainEvent::HTLCUpdate {
2006                                                                         source: (**source).clone(),
2007                                                                         payment_hash: htlc.payment_hash.clone(),
2008                                                                         htlc_value_satoshis: Some(htlc.amount_msat / 1000),
2009                                                                         commitment_tx_output_idx: None,
2010                                                                 },
2011                                                         };
2012                                                         log_trace!($logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of {} commitment transaction {}, waiting for confirmation (at height {})",
2013                                                                 log_bytes!(htlc.payment_hash.0), $commitment_tx, $commitment_tx_type,
2014                                                                 $commitment_txid_confirmed, entry.confirmation_threshold());
2015                                                         $self.onchain_events_awaiting_threshold_conf.push(entry);
2016                                                 }
2017                                         }
2018                                 }
2019                         }
2020                 }
2021                 if let Some(ref txid) = $self.current_counterparty_commitment_txid {
2022                         check_htlc_fails!(txid, "current");
2023                 }
2024                 if let Some(ref txid) = $self.prev_counterparty_commitment_txid {
2025                         check_htlc_fails!(txid, "previous");
2026                 }
2027         } }
2028 }
2029
2030 // In the `test_invalid_funding_tx` test, we need a bogus script which matches the HTLC-Accepted
2031 // witness length match (ie is 136 bytes long). We generate one here which we also use in some
2032 // in-line tests later.
2033
2034 #[cfg(test)]
2035 pub fn deliberately_bogus_accepted_htlc_witness_program() -> Vec<u8> {
2036         let mut ret = [opcodes::all::OP_NOP.to_u8(); 136];
2037         ret[131] = opcodes::all::OP_DROP.to_u8();
2038         ret[132] = opcodes::all::OP_DROP.to_u8();
2039         ret[133] = opcodes::all::OP_DROP.to_u8();
2040         ret[134] = opcodes::all::OP_DROP.to_u8();
2041         ret[135] = opcodes::OP_TRUE.to_u8();
2042         Vec::from(&ret[..])
2043 }
2044
2045 #[cfg(test)]
2046 pub fn deliberately_bogus_accepted_htlc_witness() -> Vec<Vec<u8>> {
2047         vec![Vec::new(), Vec::new(), Vec::new(), Vec::new(), deliberately_bogus_accepted_htlc_witness_program().into()].into()
2048 }
2049
2050 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
2051         /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
2052         /// needed by holder commitment transactions HTCLs nor by counterparty ones. Unless we haven't already seen
2053         /// counterparty commitment transaction's secret, they are de facto pruned (we can use revocation key).
2054         fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), &'static str> {
2055                 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
2056                         return Err("Previous secret did not match new one");
2057                 }
2058
2059                 // Prune HTLCs from the previous counterparty commitment tx so we don't generate failure/fulfill
2060                 // events for now-revoked/fulfilled HTLCs.
2061                 if let Some(txid) = self.prev_counterparty_commitment_txid.take() {
2062                         if self.current_counterparty_commitment_txid.unwrap() != txid {
2063                                 let cur_claimables = self.counterparty_claimable_outpoints.get(
2064                                         &self.current_counterparty_commitment_txid.unwrap()).unwrap();
2065                                 for (_, ref source_opt) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
2066                                         if let Some(source) = source_opt {
2067                                                 if !cur_claimables.iter()
2068                                                         .any(|(_, cur_source_opt)| cur_source_opt == source_opt)
2069                                                 {
2070                                                         self.counterparty_fulfilled_htlcs.remove(&SentHTLCId::from_source(source));
2071                                                 }
2072                                         }
2073                                 }
2074                                 for &mut (_, ref mut source_opt) in self.counterparty_claimable_outpoints.get_mut(&txid).unwrap() {
2075                                         *source_opt = None;
2076                                 }
2077                         } else {
2078                                 assert!(cfg!(fuzzing), "Commitment txids are unique outside of fuzzing, where hashes can collide");
2079                         }
2080                 }
2081
2082                 if !self.payment_preimages.is_empty() {
2083                         let cur_holder_signed_commitment_tx = &self.current_holder_commitment_tx;
2084                         let prev_holder_signed_commitment_tx = self.prev_holder_signed_commitment_tx.as_ref();
2085                         let min_idx = self.get_min_seen_secret();
2086                         let counterparty_hash_commitment_number = &mut self.counterparty_hash_commitment_number;
2087
2088                         self.payment_preimages.retain(|&k, _| {
2089                                 for &(ref htlc, _, _) in cur_holder_signed_commitment_tx.htlc_outputs.iter() {
2090                                         if k == htlc.payment_hash {
2091                                                 return true
2092                                         }
2093                                 }
2094                                 if let Some(prev_holder_commitment_tx) = prev_holder_signed_commitment_tx {
2095                                         for &(ref htlc, _, _) in prev_holder_commitment_tx.htlc_outputs.iter() {
2096                                                 if k == htlc.payment_hash {
2097                                                         return true
2098                                                 }
2099                                         }
2100                                 }
2101                                 let contains = if let Some(cn) = counterparty_hash_commitment_number.get(&k) {
2102                                         if *cn < min_idx {
2103                                                 return true
2104                                         }
2105                                         true
2106                                 } else { false };
2107                                 if contains {
2108                                         counterparty_hash_commitment_number.remove(&k);
2109                                 }
2110                                 false
2111                         });
2112                 }
2113
2114                 Ok(())
2115         }
2116
2117         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 {
2118                 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
2119                 // so that a remote monitor doesn't learn anything unless there is a malicious close.
2120                 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
2121                 // timeouts)
2122                 for &(ref htlc, _) in &htlc_outputs {
2123                         self.counterparty_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
2124                 }
2125
2126                 log_trace!(logger, "Tracking new counterparty commitment transaction with txid {} at commitment number {} with {} HTLC outputs", txid, commitment_number, htlc_outputs.len());
2127                 self.prev_counterparty_commitment_txid = self.current_counterparty_commitment_txid.take();
2128                 self.current_counterparty_commitment_txid = Some(txid);
2129                 self.counterparty_claimable_outpoints.insert(txid, htlc_outputs.clone());
2130                 self.current_counterparty_commitment_number = commitment_number;
2131                 //TODO: Merge this into the other per-counterparty-transaction output storage stuff
2132                 match self.their_cur_per_commitment_points {
2133                         Some(old_points) => {
2134                                 if old_points.0 == commitment_number + 1 {
2135                                         self.their_cur_per_commitment_points = Some((old_points.0, old_points.1, Some(their_per_commitment_point)));
2136                                 } else if old_points.0 == commitment_number + 2 {
2137                                         if let Some(old_second_point) = old_points.2 {
2138                                                 self.their_cur_per_commitment_points = Some((old_points.0 - 1, old_second_point, Some(their_per_commitment_point)));
2139                                         } else {
2140                                                 self.their_cur_per_commitment_points = Some((commitment_number, their_per_commitment_point, None));
2141                                         }
2142                                 } else {
2143                                         self.their_cur_per_commitment_points = Some((commitment_number, their_per_commitment_point, None));
2144                                 }
2145                         },
2146                         None => {
2147                                 self.their_cur_per_commitment_points = Some((commitment_number, their_per_commitment_point, None));
2148                         }
2149                 }
2150                 let mut htlcs = Vec::with_capacity(htlc_outputs.len());
2151                 for htlc in htlc_outputs {
2152                         if htlc.0.transaction_output_index.is_some() {
2153                                 htlcs.push(htlc.0);
2154                         }
2155                 }
2156         }
2157
2158         /// Informs this monitor of the latest holder (ie broadcastable) commitment transaction. The
2159         /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
2160         /// is important that any clones of this channel monitor (including remote clones) by kept
2161         /// up-to-date as our holder commitment transaction is updated.
2162         /// Panics if set_on_holder_tx_csv has never been called.
2163         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> {
2164                 // block for Rust 1.34 compat
2165                 let mut new_holder_commitment_tx = {
2166                         let trusted_tx = holder_commitment_tx.trust();
2167                         let txid = trusted_tx.txid();
2168                         let tx_keys = trusted_tx.keys();
2169                         self.current_holder_commitment_number = trusted_tx.commitment_number();
2170                         HolderSignedTx {
2171                                 txid,
2172                                 revocation_key: tx_keys.revocation_key,
2173                                 a_htlc_key: tx_keys.broadcaster_htlc_key,
2174                                 b_htlc_key: tx_keys.countersignatory_htlc_key,
2175                                 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
2176                                 per_commitment_point: tx_keys.per_commitment_point,
2177                                 htlc_outputs,
2178                                 to_self_value_sat: holder_commitment_tx.to_broadcaster_value_sat(),
2179                                 feerate_per_kw: trusted_tx.feerate_per_kw(),
2180                         }
2181                 };
2182                 self.onchain_tx_handler.provide_latest_holder_tx(holder_commitment_tx);
2183                 mem::swap(&mut new_holder_commitment_tx, &mut self.current_holder_commitment_tx);
2184                 self.prev_holder_signed_commitment_tx = Some(new_holder_commitment_tx);
2185                 for (claimed_htlc_id, claimed_preimage) in claimed_htlcs {
2186                         #[cfg(debug_assertions)] {
2187                                 let cur_counterparty_htlcs = self.counterparty_claimable_outpoints.get(
2188                                                 &self.current_counterparty_commitment_txid.unwrap()).unwrap();
2189                                 assert!(cur_counterparty_htlcs.iter().any(|(_, source_opt)| {
2190                                         if let Some(source) = source_opt {
2191                                                 SentHTLCId::from_source(source) == *claimed_htlc_id
2192                                         } else { false }
2193                                 }));
2194                         }
2195                         self.counterparty_fulfilled_htlcs.insert(*claimed_htlc_id, *claimed_preimage);
2196                 }
2197                 if self.holder_tx_signed {
2198                         return Err("Latest holder commitment signed has already been signed, update is rejected");
2199                 }
2200                 Ok(())
2201         }
2202
2203         /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
2204         /// commitment_tx_infos which contain the payment hash have been revoked.
2205         fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(
2206                 &mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage, broadcaster: &B,
2207                 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L)
2208         where B::Target: BroadcasterInterface,
2209                     F::Target: FeeEstimator,
2210                     L::Target: Logger,
2211         {
2212                 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
2213
2214                 // If the channel is force closed, try to claim the output from this preimage.
2215                 // First check if a counterparty commitment transaction has been broadcasted:
2216                 macro_rules! claim_htlcs {
2217                         ($commitment_number: expr, $txid: expr) => {
2218                                 let (htlc_claim_reqs, _) = self.get_counterparty_output_claim_info($commitment_number, $txid, None);
2219                                 self.onchain_tx_handler.update_claims_view_from_requests(htlc_claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
2220                         }
2221                 }
2222                 if let Some(txid) = self.current_counterparty_commitment_txid {
2223                         if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
2224                                 claim_htlcs!(*commitment_number, txid);
2225                                 return;
2226                         }
2227                 }
2228                 if let Some(txid) = self.prev_counterparty_commitment_txid {
2229                         if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
2230                                 claim_htlcs!(*commitment_number, txid);
2231                                 return;
2232                         }
2233                 }
2234
2235                 // Then if a holder commitment transaction has been seen on-chain, broadcast transactions
2236                 // claiming the HTLC output from each of the holder commitment transactions.
2237                 // Note that we can't just use `self.holder_tx_signed`, because that only covers the case where
2238                 // *we* sign a holder commitment transaction, not when e.g. a watchtower broadcasts one of our
2239                 // holder commitment transactions.
2240                 if self.broadcasted_holder_revokable_script.is_some() {
2241                         // Assume that the broadcasted commitment transaction confirmed in the current best
2242                         // block. Even if not, its a reasonable metric for the bump criteria on the HTLC
2243                         // transactions.
2244                         let (claim_reqs, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
2245                         self.onchain_tx_handler.update_claims_view_from_requests(claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
2246                         if let Some(ref tx) = self.prev_holder_signed_commitment_tx {
2247                                 let (claim_reqs, _) = self.get_broadcasted_holder_claims(&tx, self.best_block.height());
2248                                 self.onchain_tx_handler.update_claims_view_from_requests(claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
2249                         }
2250                 }
2251         }
2252
2253         pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
2254                 where B::Target: BroadcasterInterface,
2255                                         L::Target: Logger,
2256         {
2257                 for tx in self.get_latest_holder_commitment_txn(logger).iter() {
2258                         log_info!(logger, "Broadcasting local {}", log_tx!(tx));
2259                         broadcaster.broadcast_transaction(tx);
2260                 }
2261                 self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
2262         }
2263
2264         pub fn update_monitor<B: Deref, F: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: F, logger: &L) -> Result<(), ()>
2265         where B::Target: BroadcasterInterface,
2266                 F::Target: FeeEstimator,
2267                 L::Target: Logger,
2268         {
2269                 log_info!(logger, "Applying update to monitor {}, bringing update_id from {} to {} with {} changes.",
2270                         log_funding_info!(self), self.latest_update_id, updates.update_id, updates.updates.len());
2271                 // ChannelMonitor updates may be applied after force close if we receive a
2272                 // preimage for a broadcasted commitment transaction HTLC output that we'd
2273                 // like to claim on-chain. If this is the case, we no longer have guaranteed
2274                 // access to the monitor's update ID, so we use a sentinel value instead.
2275                 if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
2276                         assert_eq!(updates.updates.len(), 1);
2277                         match updates.updates[0] {
2278                                 ChannelMonitorUpdateStep::PaymentPreimage { .. } => {},
2279                                 _ => {
2280                                         log_error!(logger, "Attempted to apply post-force-close ChannelMonitorUpdate of type {}", updates.updates[0].variant_name());
2281                                         panic!("Attempted to apply post-force-close ChannelMonitorUpdate that wasn't providing a payment preimage");
2282                                 },
2283                         }
2284                 } else if self.latest_update_id + 1 != updates.update_id {
2285                         panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
2286                 }
2287                 let mut ret = Ok(());
2288                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&*fee_estimator);
2289                 for update in updates.updates.iter() {
2290                         match update {
2291                                 ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs, claimed_htlcs } => {
2292                                         log_trace!(logger, "Updating ChannelMonitor with latest holder commitment transaction info");
2293                                         if self.lockdown_from_offchain { panic!(); }
2294                                         if let Err(e) = self.provide_latest_holder_commitment_tx(commitment_tx.clone(), htlc_outputs.clone(), &claimed_htlcs) {
2295                                                 log_error!(logger, "Providing latest holder commitment transaction failed/was refused:");
2296                                                 log_error!(logger, "    {}", e);
2297                                                 ret = Err(());
2298                                         }
2299                                 }
2300                                 ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid, htlc_outputs, commitment_number, their_per_commitment_point } => {
2301                                         log_trace!(logger, "Updating ChannelMonitor with latest counterparty commitment transaction info");
2302                                         self.provide_latest_counterparty_commitment_tx(*commitment_txid, htlc_outputs.clone(), *commitment_number, *their_per_commitment_point, logger)
2303                                 },
2304                                 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } => {
2305                                         log_trace!(logger, "Updating ChannelMonitor with payment preimage");
2306                                         self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage, broadcaster, &bounded_fee_estimator, logger)
2307                                 },
2308                                 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } => {
2309                                         log_trace!(logger, "Updating ChannelMonitor with commitment secret");
2310                                         if let Err(e) = self.provide_secret(*idx, *secret) {
2311                                                 log_error!(logger, "Providing latest counterparty commitment secret failed/was refused:");
2312                                                 log_error!(logger, "    {}", e);
2313                                                 ret = Err(());
2314                                         }
2315                                 },
2316                                 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
2317                                         log_trace!(logger, "Updating ChannelMonitor: channel force closed, should broadcast: {}", should_broadcast);
2318                                         self.lockdown_from_offchain = true;
2319                                         if *should_broadcast {
2320                                                 // There's no need to broadcast our commitment transaction if we've seen one
2321                                                 // confirmed (even with 1 confirmation) as it'll be rejected as
2322                                                 // duplicate/conflicting.
2323                                                 let detected_funding_spend = self.funding_spend_confirmed.is_some() ||
2324                                                         self.onchain_events_awaiting_threshold_conf.iter().find(|event| match event.event {
2325                                                                 OnchainEvent::FundingSpendConfirmation { .. } => true,
2326                                                                 _ => false,
2327                                                         }).is_some();
2328                                                 if detected_funding_spend {
2329                                                         continue;
2330                                                 }
2331                                                 self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
2332                                                 // If the channel supports anchor outputs, we'll need to emit an external
2333                                                 // event to be consumed such that a child transaction is broadcast with a
2334                                                 // high enough feerate for the parent commitment transaction to confirm.
2335                                                 if self.onchain_tx_handler.opt_anchors() {
2336                                                         let funding_output = HolderFundingOutput::build(
2337                                                                 self.funding_redeemscript.clone(), self.channel_value_satoshis,
2338                                                                 self.onchain_tx_handler.opt_anchors(),
2339                                                         );
2340                                                         let best_block_height = self.best_block.height();
2341                                                         let commitment_package = PackageTemplate::build_package(
2342                                                                 self.funding_info.0.txid.clone(), self.funding_info.0.index as u32,
2343                                                                 PackageSolvingData::HolderFundingOutput(funding_output),
2344                                                                 best_block_height, false, best_block_height,
2345                                                         );
2346                                                         self.onchain_tx_handler.update_claims_view_from_requests(
2347                                                                 vec![commitment_package], best_block_height, best_block_height,
2348                                                                 broadcaster, &bounded_fee_estimator, logger,
2349                                                         );
2350                                                 }
2351                                         } else if !self.holder_tx_signed {
2352                                                 log_error!(logger, "WARNING: You have a potentially-unsafe holder commitment transaction available to broadcast");
2353                                                 log_error!(logger, "    in channel monitor for channel {}!", log_bytes!(self.funding_info.0.to_channel_id()));
2354                                                 log_error!(logger, "    Read the docs for ChannelMonitor::get_latest_holder_commitment_txn and take manual action!");
2355                                         } else {
2356                                                 // If we generated a MonitorEvent::CommitmentTxConfirmed, the ChannelManager
2357                                                 // will still give us a ChannelForceClosed event with !should_broadcast, but we
2358                                                 // shouldn't print the scary warning above.
2359                                                 log_info!(logger, "Channel off-chain state closed after we broadcasted our latest commitment transaction.");
2360                                         }
2361                                 },
2362                                 ChannelMonitorUpdateStep::ShutdownScript { scriptpubkey } => {
2363                                         log_trace!(logger, "Updating ChannelMonitor with shutdown script");
2364                                         if let Some(shutdown_script) = self.shutdown_script.replace(scriptpubkey.clone()) {
2365                                                 panic!("Attempted to replace shutdown script {} with {}", shutdown_script, scriptpubkey);
2366                                         }
2367                                 },
2368                         }
2369                 }
2370                 self.latest_update_id = updates.update_id;
2371
2372                 if ret.is_ok() && self.funding_spend_seen {
2373                         log_error!(logger, "Refusing Channel Monitor Update as counterparty attempted to update commitment after funding was spent");
2374                         Err(())
2375                 } else { ret }
2376         }
2377
2378         pub fn get_latest_update_id(&self) -> u64 {
2379                 self.latest_update_id
2380         }
2381
2382         pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
2383                 &self.funding_info
2384         }
2385
2386         pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<(u32, Script)>> {
2387                 // If we've detected a counterparty commitment tx on chain, we must include it in the set
2388                 // of outputs to watch for spends of, otherwise we're likely to lose user funds. Because
2389                 // its trivial to do, double-check that here.
2390                 for (txid, _) in self.counterparty_commitment_txn_on_chain.iter() {
2391                         self.outputs_to_watch.get(txid).expect("Counterparty commitment txn which have been broadcast should have outputs registered");
2392                 }
2393                 &self.outputs_to_watch
2394         }
2395
2396         pub fn get_and_clear_pending_monitor_events(&mut self) -> Vec<MonitorEvent> {
2397                 let mut ret = Vec::new();
2398                 mem::swap(&mut ret, &mut self.pending_monitor_events);
2399                 ret
2400         }
2401
2402         pub fn get_and_clear_pending_events(&mut self) -> Vec<Event> {
2403                 let mut ret = Vec::new();
2404                 mem::swap(&mut ret, &mut self.pending_events);
2405                 #[cfg(anchors)]
2406                 for claim_event in self.onchain_tx_handler.get_and_clear_pending_claim_events().drain(..) {
2407                         match claim_event {
2408                                 ClaimEvent::BumpCommitment {
2409                                         package_target_feerate_sat_per_1000_weight, commitment_tx, anchor_output_idx,
2410                                 } => {
2411                                         let commitment_txid = commitment_tx.txid();
2412                                         debug_assert_eq!(self.current_holder_commitment_tx.txid, commitment_txid);
2413                                         let pending_htlcs = self.current_holder_commitment_tx.non_dust_htlcs();
2414                                         let commitment_tx_fee_satoshis = self.channel_value_satoshis -
2415                                                 commitment_tx.output.iter().fold(0u64, |sum, output| sum + output.value);
2416                                         ret.push(Event::BumpTransaction(BumpTransactionEvent::ChannelClose {
2417                                                 package_target_feerate_sat_per_1000_weight,
2418                                                 commitment_tx,
2419                                                 commitment_tx_fee_satoshis,
2420                                                 anchor_descriptor: AnchorDescriptor {
2421                                                         channel_keys_id: self.channel_keys_id,
2422                                                         channel_value_satoshis: self.channel_value_satoshis,
2423                                                         outpoint: BitcoinOutPoint {
2424                                                                 txid: commitment_txid,
2425                                                                 vout: anchor_output_idx,
2426                                                         },
2427                                                 },
2428                                                 pending_htlcs,
2429                                         }));
2430                                 },
2431                                 ClaimEvent::BumpHTLC {
2432                                         target_feerate_sat_per_1000_weight, htlcs,
2433                                 } => {
2434                                         let mut htlc_descriptors = Vec::with_capacity(htlcs.len());
2435                                         for htlc in htlcs {
2436                                                 htlc_descriptors.push(HTLCDescriptor {
2437                                                         channel_keys_id: self.channel_keys_id,
2438                                                         channel_value_satoshis: self.channel_value_satoshis,
2439                                                         channel_parameters: self.onchain_tx_handler.channel_transaction_parameters.clone(),
2440                                                         commitment_txid: htlc.commitment_txid,
2441                                                         per_commitment_number: htlc.per_commitment_number,
2442                                                         htlc: htlc.htlc,
2443                                                         preimage: htlc.preimage,
2444                                                         counterparty_sig: htlc.counterparty_sig,
2445                                                 });
2446                                         }
2447                                         ret.push(Event::BumpTransaction(BumpTransactionEvent::HTLCResolution {
2448                                                 target_feerate_sat_per_1000_weight,
2449                                                 htlc_descriptors,
2450                                         }));
2451                                 }
2452                         }
2453                 }
2454                 ret
2455         }
2456
2457         /// Can only fail if idx is < get_min_seen_secret
2458         fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
2459                 self.commitment_secrets.get_secret(idx)
2460         }
2461
2462         pub(crate) fn get_min_seen_secret(&self) -> u64 {
2463                 self.commitment_secrets.get_min_seen_secret()
2464         }
2465
2466         pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
2467                 self.current_counterparty_commitment_number
2468         }
2469
2470         pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
2471                 self.current_holder_commitment_number
2472         }
2473
2474         /// Attempts to claim a counterparty commitment transaction's outputs using the revocation key and
2475         /// data in counterparty_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
2476         /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
2477         /// HTLC-Success/HTLC-Timeout transactions.
2478         ///
2479         /// Returns packages to claim the revoked output(s), as well as additional outputs to watch and
2480         /// general information about the output that is to the counterparty in the commitment
2481         /// transaction.
2482         fn check_spend_counterparty_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, block_hash: &BlockHash, logger: &L)
2483                 -> (Vec<PackageTemplate>, TransactionOutputs, CommitmentTxCounterpartyOutputInfo)
2484         where L::Target: Logger {
2485                 // Most secp and related errors trying to create keys means we have no hope of constructing
2486                 // a spend transaction...so we return no transactions to broadcast
2487                 let mut claimable_outpoints = Vec::new();
2488                 let mut watch_outputs = Vec::new();
2489                 let mut to_counterparty_output_info = None;
2490
2491                 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
2492                 let per_commitment_option = self.counterparty_claimable_outpoints.get(&commitment_txid);
2493
2494                 macro_rules! ignore_error {
2495                         ( $thing : expr ) => {
2496                                 match $thing {
2497                                         Ok(a) => a,
2498                                         Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs), to_counterparty_output_info)
2499                                 }
2500                         };
2501                 }
2502
2503                 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);
2504                 if commitment_number >= self.get_min_seen_secret() {
2505                         let secret = self.get_secret(commitment_number).unwrap();
2506                         let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
2507                         let per_commitment_point = PublicKey::from_secret_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_key);
2508                         let revocation_pubkey = chan_utils::derive_public_revocation_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint);
2509                         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);
2510
2511                         let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.counterparty_commitment_params.on_counterparty_tx_csv, &delayed_key);
2512                         let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
2513
2514                         // First, process non-htlc outputs (to_holder & to_counterparty)
2515                         for (idx, outp) in tx.output.iter().enumerate() {
2516                                 if outp.script_pubkey == revokeable_p2wsh {
2517                                         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);
2518                                         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);
2519                                         claimable_outpoints.push(justice_package);
2520                                         to_counterparty_output_info =
2521                                                 Some((idx.try_into().expect("Txn can't have more than 2^32 outputs"), outp.value));
2522                                 }
2523                         }
2524
2525                         // Then, try to find revoked htlc outputs
2526                         if let Some(ref per_commitment_data) = per_commitment_option {
2527                                 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
2528                                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2529                                                 if transaction_output_index as usize >= tx.output.len() ||
2530                                                                 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
2531                                                         // per_commitment_data is corrupt or our commitment signing key leaked!
2532                                                         return (claimable_outpoints, (commitment_txid, watch_outputs),
2533                                                                 to_counterparty_output_info);
2534                                                 }
2535                                                 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());
2536                                                 let justice_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, PackageSolvingData::RevokedHTLCOutput(revk_htlc_outp), htlc.cltv_expiry, true, height);
2537                                                 claimable_outpoints.push(justice_package);
2538                                         }
2539                                 }
2540                         }
2541
2542                         // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
2543                         if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
2544                                 // We're definitely a counterparty commitment transaction!
2545                                 log_error!(logger, "Got broadcast of revoked counterparty commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
2546                                 for (idx, outp) in tx.output.iter().enumerate() {
2547                                         watch_outputs.push((idx as u32, outp.clone()));
2548                                 }
2549                                 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
2550
2551                                 if let Some(per_commitment_data) = per_commitment_option {
2552                                         fail_unbroadcast_htlcs!(self, "revoked_counterparty", commitment_txid, tx, height,
2553                                                 block_hash, per_commitment_data.iter().map(|(htlc, htlc_source)|
2554                                                         (htlc, htlc_source.as_ref().map(|htlc_source| htlc_source.as_ref()))
2555                                                 ), logger);
2556                                 } else {
2557                                         debug_assert!(false, "We should have per-commitment option for any recognized old commitment txn");
2558                                         fail_unbroadcast_htlcs!(self, "revoked counterparty", commitment_txid, tx, height,
2559                                                 block_hash, [].iter().map(|reference| *reference), logger);
2560                                 }
2561                         }
2562                 } else if let Some(per_commitment_data) = per_commitment_option {
2563                         // While this isn't useful yet, there is a potential race where if a counterparty
2564                         // revokes a state at the same time as the commitment transaction for that state is
2565                         // confirmed, and the watchtower receives the block before the user, the user could
2566                         // upload a new ChannelMonitor with the revocation secret but the watchtower has
2567                         // already processed the block, resulting in the counterparty_commitment_txn_on_chain entry
2568                         // not being generated by the above conditional. Thus, to be safe, we go ahead and
2569                         // insert it here.
2570                         for (idx, outp) in tx.output.iter().enumerate() {
2571                                 watch_outputs.push((idx as u32, outp.clone()));
2572                         }
2573                         self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
2574
2575                         log_info!(logger, "Got broadcast of non-revoked counterparty commitment transaction {}", commitment_txid);
2576                         fail_unbroadcast_htlcs!(self, "counterparty", commitment_txid, tx, height, block_hash,
2577                                 per_commitment_data.iter().map(|(htlc, htlc_source)|
2578                                         (htlc, htlc_source.as_ref().map(|htlc_source| htlc_source.as_ref()))
2579                                 ), logger);
2580
2581                         let (htlc_claim_reqs, counterparty_output_info) =
2582                                 self.get_counterparty_output_claim_info(commitment_number, commitment_txid, Some(tx));
2583                         to_counterparty_output_info = counterparty_output_info;
2584                         for req in htlc_claim_reqs {
2585                                 claimable_outpoints.push(req);
2586                         }
2587
2588                 }
2589                 (claimable_outpoints, (commitment_txid, watch_outputs), to_counterparty_output_info)
2590         }
2591
2592         /// Returns the HTLC claim package templates and the counterparty output info
2593         fn get_counterparty_output_claim_info(&self, commitment_number: u64, commitment_txid: Txid, tx: Option<&Transaction>)
2594         -> (Vec<PackageTemplate>, CommitmentTxCounterpartyOutputInfo) {
2595                 let mut claimable_outpoints = Vec::new();
2596                 let mut to_counterparty_output_info: CommitmentTxCounterpartyOutputInfo = None;
2597
2598                 let htlc_outputs = match self.counterparty_claimable_outpoints.get(&commitment_txid) {
2599                         Some(outputs) => outputs,
2600                         None => return (claimable_outpoints, to_counterparty_output_info),
2601                 };
2602                 let per_commitment_points = match self.their_cur_per_commitment_points {
2603                         Some(points) => points,
2604                         None => return (claimable_outpoints, to_counterparty_output_info),
2605                 };
2606
2607                 let per_commitment_point =
2608                         // If the counterparty commitment tx is the latest valid state, use their latest
2609                         // per-commitment point
2610                         if per_commitment_points.0 == commitment_number { &per_commitment_points.1 }
2611                         else if let Some(point) = per_commitment_points.2.as_ref() {
2612                                 // If counterparty commitment tx is the state previous to the latest valid state, use
2613                                 // their previous per-commitment point (non-atomicity of revocation means it's valid for
2614                                 // them to temporarily have two valid commitment txns from our viewpoint)
2615                                 if per_commitment_points.0 == commitment_number + 1 {
2616                                         point
2617                                 } else { return (claimable_outpoints, to_counterparty_output_info); }
2618                         } else { return (claimable_outpoints, to_counterparty_output_info); };
2619
2620                 if let Some(transaction) = tx {
2621                         let revocation_pubkey = chan_utils::derive_public_revocation_key(
2622                                 &self.onchain_tx_handler.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint);
2623                         let delayed_key = chan_utils::derive_public_key(&self.onchain_tx_handler.secp_ctx,
2624                                 &per_commitment_point,
2625                                 &self.counterparty_commitment_params.counterparty_delayed_payment_base_key);
2626                         let revokeable_p2wsh = chan_utils::get_revokeable_redeemscript(&revocation_pubkey,
2627                                 self.counterparty_commitment_params.on_counterparty_tx_csv,
2628                                 &delayed_key).to_v0_p2wsh();
2629                         for (idx, outp) in transaction.output.iter().enumerate() {
2630                                 if outp.script_pubkey == revokeable_p2wsh {
2631                                         to_counterparty_output_info =
2632                                                 Some((idx.try_into().expect("Can't have > 2^32 outputs"), outp.value));
2633                                 }
2634                         }
2635                 }
2636
2637                 for (_, &(ref htlc, _)) in htlc_outputs.iter().enumerate() {
2638                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2639                                 if let Some(transaction) = tx {
2640                                         if transaction_output_index as usize >= transaction.output.len() ||
2641                                                 transaction.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
2642                                                         // per_commitment_data is corrupt or our commitment signing key leaked!
2643                                                         return (claimable_outpoints, to_counterparty_output_info);
2644                                                 }
2645                                 }
2646                                 let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
2647                                 if preimage.is_some() || !htlc.offered {
2648                                         let counterparty_htlc_outp = if htlc.offered {
2649                                                 PackageSolvingData::CounterpartyOfferedHTLCOutput(
2650                                                         CounterpartyOfferedHTLCOutput::build(*per_commitment_point,
2651                                                                 self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
2652                                                                 self.counterparty_commitment_params.counterparty_htlc_base_key,
2653                                                                 preimage.unwrap(), htlc.clone(), self.onchain_tx_handler.opt_anchors()))
2654                                         } else {
2655                                                 PackageSolvingData::CounterpartyReceivedHTLCOutput(
2656                                                         CounterpartyReceivedHTLCOutput::build(*per_commitment_point,
2657                                                                 self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
2658                                                                 self.counterparty_commitment_params.counterparty_htlc_base_key,
2659                                                                 htlc.clone(), self.onchain_tx_handler.opt_anchors()))
2660                                         };
2661                                         let aggregation = if !htlc.offered { false } else { true };
2662                                         let counterparty_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, counterparty_htlc_outp, htlc.cltv_expiry,aggregation, 0);
2663                                         claimable_outpoints.push(counterparty_package);
2664                                 }
2665                         }
2666                 }
2667
2668                 (claimable_outpoints, to_counterparty_output_info)
2669         }
2670
2671         /// Attempts to claim a counterparty HTLC-Success/HTLC-Timeout's outputs using the revocation key
2672         fn check_spend_counterparty_htlc<L: Deref>(
2673                 &mut self, tx: &Transaction, commitment_number: u64, commitment_txid: &Txid, height: u32, logger: &L
2674         ) -> (Vec<PackageTemplate>, Option<TransactionOutputs>) where L::Target: Logger {
2675                 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
2676                 let per_commitment_key = match SecretKey::from_slice(&secret) {
2677                         Ok(key) => key,
2678                         Err(_) => return (Vec::new(), None)
2679                 };
2680                 let per_commitment_point = PublicKey::from_secret_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_key);
2681
2682                 let htlc_txid = tx.txid();
2683                 let mut claimable_outpoints = vec![];
2684                 let mut outputs_to_watch = None;
2685                 // Previously, we would only claim HTLCs from revoked HTLC transactions if they had 1 input
2686                 // with a witness of 5 elements and 1 output. This wasn't enough for anchor outputs, as the
2687                 // counterparty can now aggregate multiple HTLCs into a single transaction thanks to
2688                 // `SIGHASH_SINGLE` remote signatures, leading us to not claim any HTLCs upon seeing a
2689                 // confirmed revoked HTLC transaction (for more details, see
2690                 // https://lists.linuxfoundation.org/pipermail/lightning-dev/2022-April/003561.html).
2691                 //
2692                 // We make sure we're not vulnerable to this case by checking all inputs of the transaction,
2693                 // and claim those which spend the commitment transaction, have a witness of 5 elements, and
2694                 // have a corresponding output at the same index within the transaction.
2695                 for (idx, input) in tx.input.iter().enumerate() {
2696                         if input.previous_output.txid == *commitment_txid && input.witness.len() == 5 && tx.output.get(idx).is_some() {
2697                                 log_error!(logger, "Got broadcast of revoked counterparty HTLC transaction, spending {}:{}", htlc_txid, idx);
2698                                 let revk_outp = RevokedOutput::build(
2699                                         per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
2700                                         self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key,
2701                                         tx.output[idx].value, self.counterparty_commitment_params.on_counterparty_tx_csv
2702                                 );
2703                                 let justice_package = PackageTemplate::build_package(
2704                                         htlc_txid, idx as u32, PackageSolvingData::RevokedOutput(revk_outp),
2705                                         height + self.counterparty_commitment_params.on_counterparty_tx_csv as u32, true, height
2706                                 );
2707                                 claimable_outpoints.push(justice_package);
2708                                 if outputs_to_watch.is_none() {
2709                                         outputs_to_watch = Some((htlc_txid, vec![]));
2710                                 }
2711                                 outputs_to_watch.as_mut().unwrap().1.push((idx as u32, tx.output[idx].clone()));
2712                         }
2713                 }
2714                 (claimable_outpoints, outputs_to_watch)
2715         }
2716
2717         // Returns (1) `PackageTemplate`s that can be given to the OnchainTxHandler, so that the handler can
2718         // broadcast transactions claiming holder HTLC commitment outputs and (2) a holder revokable
2719         // script so we can detect whether a holder transaction has been seen on-chain.
2720         fn get_broadcasted_holder_claims(&self, holder_tx: &HolderSignedTx, conf_height: u32) -> (Vec<PackageTemplate>, Option<(Script, PublicKey, PublicKey)>) {
2721                 let mut claim_requests = Vec::with_capacity(holder_tx.htlc_outputs.len());
2722
2723                 let redeemscript = chan_utils::get_revokeable_redeemscript(&holder_tx.revocation_key, self.on_holder_tx_csv, &holder_tx.delayed_payment_key);
2724                 let broadcasted_holder_revokable_script = Some((redeemscript.to_v0_p2wsh(), holder_tx.per_commitment_point.clone(), holder_tx.revocation_key.clone()));
2725
2726                 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
2727                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2728                                 let (htlc_output, aggregable) = if htlc.offered {
2729                                         let htlc_output = HolderHTLCOutput::build_offered(
2730                                                 htlc.amount_msat, htlc.cltv_expiry, self.onchain_tx_handler.opt_anchors()
2731                                         );
2732                                         (htlc_output, false)
2733                                 } else {
2734                                         let payment_preimage = if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
2735                                                 preimage.clone()
2736                                         } else {
2737                                                 // We can't build an HTLC-Success transaction without the preimage
2738                                                 continue;
2739                                         };
2740                                         let htlc_output = HolderHTLCOutput::build_accepted(
2741                                                 payment_preimage, htlc.amount_msat, self.onchain_tx_handler.opt_anchors()
2742                                         );
2743                                         (htlc_output, self.onchain_tx_handler.opt_anchors())
2744                                 };
2745                                 let htlc_package = PackageTemplate::build_package(
2746                                         holder_tx.txid, transaction_output_index,
2747                                         PackageSolvingData::HolderHTLCOutput(htlc_output),
2748                                         htlc.cltv_expiry, aggregable, conf_height
2749                                 );
2750                                 claim_requests.push(htlc_package);
2751                         }
2752                 }
2753
2754                 (claim_requests, broadcasted_holder_revokable_script)
2755         }
2756
2757         // Returns holder HTLC outputs to watch and react to in case of spending.
2758         fn get_broadcasted_holder_watch_outputs(&self, holder_tx: &HolderSignedTx, commitment_tx: &Transaction) -> Vec<(u32, TxOut)> {
2759                 let mut watch_outputs = Vec::with_capacity(holder_tx.htlc_outputs.len());
2760                 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
2761                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2762                                 watch_outputs.push((transaction_output_index, commitment_tx.output[transaction_output_index as usize].clone()));
2763                         }
2764                 }
2765                 watch_outputs
2766         }
2767
2768         /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
2769         /// revoked using data in holder_claimable_outpoints.
2770         /// Should not be used if check_spend_revoked_transaction succeeds.
2771         /// Returns None unless the transaction is definitely one of our commitment transactions.
2772         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 {
2773                 let commitment_txid = tx.txid();
2774                 let mut claim_requests = Vec::new();
2775                 let mut watch_outputs = Vec::new();
2776
2777                 macro_rules! append_onchain_update {
2778                         ($updates: expr, $to_watch: expr) => {
2779                                 claim_requests = $updates.0;
2780                                 self.broadcasted_holder_revokable_script = $updates.1;
2781                                 watch_outputs.append(&mut $to_watch);
2782                         }
2783                 }
2784
2785                 // HTLCs set may differ between last and previous holder commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
2786                 let mut is_holder_tx = false;
2787
2788                 if self.current_holder_commitment_tx.txid == commitment_txid {
2789                         is_holder_tx = true;
2790                         log_info!(logger, "Got broadcast of latest holder commitment tx {}, searching for available HTLCs to claim", commitment_txid);
2791                         let res = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, height);
2792                         let mut to_watch = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, tx);
2793                         append_onchain_update!(res, to_watch);
2794                         fail_unbroadcast_htlcs!(self, "latest holder", commitment_txid, tx, height,
2795                                 block_hash, self.current_holder_commitment_tx.htlc_outputs.iter()
2796                                 .map(|(htlc, _, htlc_source)| (htlc, htlc_source.as_ref())), logger);
2797                 } else if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
2798                         if holder_tx.txid == commitment_txid {
2799                                 is_holder_tx = true;
2800                                 log_info!(logger, "Got broadcast of previous holder commitment tx {}, searching for available HTLCs to claim", commitment_txid);
2801                                 let res = self.get_broadcasted_holder_claims(holder_tx, height);
2802                                 let mut to_watch = self.get_broadcasted_holder_watch_outputs(holder_tx, tx);
2803                                 append_onchain_update!(res, to_watch);
2804                                 fail_unbroadcast_htlcs!(self, "previous holder", commitment_txid, tx, height, block_hash,
2805                                         holder_tx.htlc_outputs.iter().map(|(htlc, _, htlc_source)| (htlc, htlc_source.as_ref())),
2806                                         logger);
2807                         }
2808                 }
2809
2810                 if is_holder_tx {
2811                         Some((claim_requests, (commitment_txid, watch_outputs)))
2812                 } else {
2813                         None
2814                 }
2815         }
2816
2817         pub fn get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
2818                 log_debug!(logger, "Getting signed latest holder commitment transaction!");
2819                 self.holder_tx_signed = true;
2820                 let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
2821                 let txid = commitment_tx.txid();
2822                 let mut holder_transactions = vec![commitment_tx];
2823                 // When anchor outputs are present, the HTLC transactions are only valid once the commitment
2824                 // transaction confirms.
2825                 if self.onchain_tx_handler.opt_anchors() {
2826                         return holder_transactions;
2827                 }
2828                 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
2829                         if let Some(vout) = htlc.0.transaction_output_index {
2830                                 let preimage = if !htlc.0.offered {
2831                                         if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
2832                                                 // We can't build an HTLC-Success transaction without the preimage
2833                                                 continue;
2834                                         }
2835                                 } else if htlc.0.cltv_expiry > self.best_block.height() + 1 {
2836                                         // Don't broadcast HTLC-Timeout transactions immediately as they don't meet the
2837                                         // current locktime requirements on-chain. We will broadcast them in
2838                                         // `block_confirmed` when `should_broadcast_holder_commitment_txn` returns true.
2839                                         // Note that we add + 1 as transactions are broadcastable when they can be
2840                                         // confirmed in the next block.
2841                                         continue;
2842                                 } else { None };
2843                                 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
2844                                         &::bitcoin::OutPoint { txid, vout }, &preimage) {
2845                                         holder_transactions.push(htlc_tx);
2846                                 }
2847                         }
2848                 }
2849                 // 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.
2850                 // The data will be re-generated and tracked in check_spend_holder_transaction if we get a confirmation.
2851                 holder_transactions
2852         }
2853
2854         #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
2855         /// Note that this includes possibly-locktimed-in-the-future transactions!
2856         fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
2857                 log_debug!(logger, "Getting signed copy of latest holder commitment transaction!");
2858                 let commitment_tx = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript);
2859                 let txid = commitment_tx.txid();
2860                 let mut holder_transactions = vec![commitment_tx];
2861                 // When anchor outputs are present, the HTLC transactions are only final once the commitment
2862                 // transaction confirms due to the CSV 1 encumberance.
2863                 if self.onchain_tx_handler.opt_anchors() {
2864                         return holder_transactions;
2865                 }
2866                 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
2867                         if let Some(vout) = htlc.0.transaction_output_index {
2868                                 let preimage = if !htlc.0.offered {
2869                                         if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
2870                                                 // We can't build an HTLC-Success transaction without the preimage
2871                                                 continue;
2872                                         }
2873                                 } else { None };
2874                                 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
2875                                         &::bitcoin::OutPoint { txid, vout }, &preimage) {
2876                                         holder_transactions.push(htlc_tx);
2877                                 }
2878                         }
2879                 }
2880                 holder_transactions
2881         }
2882
2883         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>
2884                 where B::Target: BroadcasterInterface,
2885                       F::Target: FeeEstimator,
2886                                         L::Target: Logger,
2887         {
2888                 let block_hash = header.block_hash();
2889                 self.best_block = BestBlock::new(block_hash, height);
2890
2891                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
2892                 self.transactions_confirmed(header, txdata, height, broadcaster, &bounded_fee_estimator, logger)
2893         }
2894
2895         fn best_block_updated<B: Deref, F: Deref, L: Deref>(
2896                 &mut self,
2897                 header: &BlockHeader,
2898                 height: u32,
2899                 broadcaster: B,
2900                 fee_estimator: &LowerBoundedFeeEstimator<F>,
2901                 logger: L,
2902         ) -> Vec<TransactionOutputs>
2903         where
2904                 B::Target: BroadcasterInterface,
2905                 F::Target: FeeEstimator,
2906                 L::Target: Logger,
2907         {
2908                 let block_hash = header.block_hash();
2909
2910                 if height > self.best_block.height() {
2911                         self.best_block = BestBlock::new(block_hash, height);
2912                         self.block_confirmed(height, block_hash, vec![], vec![], vec![], &broadcaster, &fee_estimator, &logger)
2913                 } else if block_hash != self.best_block.block_hash() {
2914                         self.best_block = BestBlock::new(block_hash, height);
2915                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height <= height);
2916                         self.onchain_tx_handler.block_disconnected(height + 1, broadcaster, fee_estimator, logger);
2917                         Vec::new()
2918                 } else { Vec::new() }
2919         }
2920
2921         fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
2922                 &mut self,
2923                 header: &BlockHeader,
2924                 txdata: &TransactionData,
2925                 height: u32,
2926                 broadcaster: B,
2927                 fee_estimator: &LowerBoundedFeeEstimator<F>,
2928                 logger: L,
2929         ) -> Vec<TransactionOutputs>
2930         where
2931                 B::Target: BroadcasterInterface,
2932                 F::Target: FeeEstimator,
2933                 L::Target: Logger,
2934         {
2935                 let txn_matched = self.filter_block(txdata);
2936                 for tx in &txn_matched {
2937                         let mut output_val = 0;
2938                         for out in tx.output.iter() {
2939                                 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
2940                                 output_val += out.value;
2941                                 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
2942                         }
2943                 }
2944
2945                 let block_hash = header.block_hash();
2946
2947                 let mut watch_outputs = Vec::new();
2948                 let mut claimable_outpoints = Vec::new();
2949                 'tx_iter: for tx in &txn_matched {
2950                         let txid = tx.txid();
2951                         // If a transaction has already been confirmed, ensure we don't bother processing it duplicatively.
2952                         if Some(txid) == self.funding_spend_confirmed {
2953                                 log_debug!(logger, "Skipping redundant processing of funding-spend tx {} as it was previously confirmed", txid);
2954                                 continue 'tx_iter;
2955                         }
2956                         for ev in self.onchain_events_awaiting_threshold_conf.iter() {
2957                                 if ev.txid == txid {
2958                                         if let Some(conf_hash) = ev.block_hash {
2959                                                 assert_eq!(header.block_hash(), conf_hash,
2960                                                         "Transaction {} was already confirmed and is being re-confirmed in a different block.\n\
2961                                                         This indicates a severe bug in the transaction connection logic - a reorg should have been processed first!", ev.txid);
2962                                         }
2963                                         log_debug!(logger, "Skipping redundant processing of confirming tx {} as it was previously confirmed", txid);
2964                                         continue 'tx_iter;
2965                                 }
2966                         }
2967                         for htlc in self.htlcs_resolved_on_chain.iter() {
2968                                 if Some(txid) == htlc.resolving_txid {
2969                                         log_debug!(logger, "Skipping redundant processing of HTLC resolution tx {} as it was previously confirmed", txid);
2970                                         continue 'tx_iter;
2971                                 }
2972                         }
2973                         for spendable_txid in self.spendable_txids_confirmed.iter() {
2974                                 if txid == *spendable_txid {
2975                                         log_debug!(logger, "Skipping redundant processing of spendable tx {} as it was previously confirmed", txid);
2976                                         continue 'tx_iter;
2977                                 }
2978                         }
2979
2980                         if tx.input.len() == 1 {
2981                                 // Assuming our keys were not leaked (in which case we're screwed no matter what),
2982                                 // commitment transactions and HTLC transactions will all only ever have one input
2983                                 // (except for HTLC transactions for channels with anchor outputs), which is an easy
2984                                 // way to filter out any potential non-matching txn for lazy filters.
2985                                 let prevout = &tx.input[0].previous_output;
2986                                 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
2987                                         let mut balance_spendable_csv = None;
2988                                         log_info!(logger, "Channel {} closed by funding output spend in txid {}.",
2989                                                 log_bytes!(self.funding_info.0.to_channel_id()), txid);
2990                                         self.funding_spend_seen = true;
2991                                         let mut commitment_tx_to_counterparty_output = None;
2992                                         if (tx.input[0].sequence.0 >> 8*3) as u8 == 0x80 && (tx.lock_time.0 >> 8*3) as u8 == 0x20 {
2993                                                 let (mut new_outpoints, new_outputs, counterparty_output_idx_sats) =
2994                                                         self.check_spend_counterparty_transaction(&tx, height, &block_hash, &logger);
2995                                                 commitment_tx_to_counterparty_output = counterparty_output_idx_sats;
2996                                                 if !new_outputs.1.is_empty() {
2997                                                         watch_outputs.push(new_outputs);
2998                                                 }
2999                                                 claimable_outpoints.append(&mut new_outpoints);
3000                                                 if new_outpoints.is_empty() {
3001                                                         if let Some((mut new_outpoints, new_outputs)) = self.check_spend_holder_transaction(&tx, height, &block_hash, &logger) {
3002                                                                 debug_assert!(commitment_tx_to_counterparty_output.is_none(),
3003                                                                         "A commitment transaction matched as both a counterparty and local commitment tx?");
3004                                                                 if !new_outputs.1.is_empty() {
3005                                                                         watch_outputs.push(new_outputs);
3006                                                                 }
3007                                                                 claimable_outpoints.append(&mut new_outpoints);
3008                                                                 balance_spendable_csv = Some(self.on_holder_tx_csv);
3009                                                         }
3010                                                 }
3011                                         }
3012                                         self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3013                                                 txid,
3014                                                 transaction: Some((*tx).clone()),
3015                                                 height,
3016                                                 block_hash: Some(block_hash),
3017                                                 event: OnchainEvent::FundingSpendConfirmation {
3018                                                         on_local_output_csv: balance_spendable_csv,
3019                                                         commitment_tx_to_counterparty_output,
3020                                                 },
3021                                         });
3022                                 }
3023                         }
3024                         if tx.input.len() >= 1 {
3025                                 // While all commitment transactions have one input, HTLC transactions may have more
3026                                 // if the HTLC was present in an anchor channel. HTLCs can also be resolved in a few
3027                                 // other ways which can have more than one output.
3028                                 for tx_input in &tx.input {
3029                                         let commitment_txid = tx_input.previous_output.txid;
3030                                         if let Some(&commitment_number) = self.counterparty_commitment_txn_on_chain.get(&commitment_txid) {
3031                                                 let (mut new_outpoints, new_outputs_option) = self.check_spend_counterparty_htlc(
3032                                                         &tx, commitment_number, &commitment_txid, height, &logger
3033                                                 );
3034                                                 claimable_outpoints.append(&mut new_outpoints);
3035                                                 if let Some(new_outputs) = new_outputs_option {
3036                                                         watch_outputs.push(new_outputs);
3037                                                 }
3038                                                 // Since there may be multiple HTLCs for this channel (all spending the
3039                                                 // same commitment tx) being claimed by the counterparty within the same
3040                                                 // transaction, and `check_spend_counterparty_htlc` already checks all the
3041                                                 // ones relevant to this channel, we can safely break from our loop.
3042                                                 break;
3043                                         }
3044                                 }
3045                                 self.is_resolving_htlc_output(&tx, height, &block_hash, &logger);
3046
3047                                 self.is_paying_spendable_output(&tx, height, &block_hash, &logger);
3048                         }
3049                 }
3050
3051                 if height > self.best_block.height() {
3052                         self.best_block = BestBlock::new(block_hash, height);
3053                 }
3054
3055                 self.block_confirmed(height, block_hash, txn_matched, watch_outputs, claimable_outpoints, &broadcaster, &fee_estimator, &logger)
3056         }
3057
3058         /// Update state for new block(s)/transaction(s) confirmed. Note that the caller must update
3059         /// `self.best_block` before calling if a new best blockchain tip is available. More
3060         /// concretely, `self.best_block` must never be at a lower height than `conf_height`, avoiding
3061         /// complexity especially in
3062         /// `OnchainTx::update_claims_view_from_requests`/`OnchainTx::update_claims_view_from_matched_txn`.
3063         ///
3064         /// `conf_height` should be set to the height at which any new transaction(s)/block(s) were
3065         /// confirmed at, even if it is not the current best height.
3066         fn block_confirmed<B: Deref, F: Deref, L: Deref>(
3067                 &mut self,
3068                 conf_height: u32,
3069                 conf_hash: BlockHash,
3070                 txn_matched: Vec<&Transaction>,
3071                 mut watch_outputs: Vec<TransactionOutputs>,
3072                 mut claimable_outpoints: Vec<PackageTemplate>,
3073                 broadcaster: &B,
3074                 fee_estimator: &LowerBoundedFeeEstimator<F>,
3075                 logger: &L,
3076         ) -> Vec<TransactionOutputs>
3077         where
3078                 B::Target: BroadcasterInterface,
3079                 F::Target: FeeEstimator,
3080                 L::Target: Logger,
3081         {
3082                 log_trace!(logger, "Processing {} matched transactions for block at height {}.", txn_matched.len(), conf_height);
3083                 debug_assert!(self.best_block.height() >= conf_height);
3084
3085                 let should_broadcast = self.should_broadcast_holder_commitment_txn(logger);
3086                 if should_broadcast {
3087                         let funding_outp = HolderFundingOutput::build(self.funding_redeemscript.clone(), self.channel_value_satoshis, self.onchain_tx_handler.opt_anchors());
3088                         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());
3089                         claimable_outpoints.push(commitment_package);
3090                         self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
3091                         let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
3092                         self.holder_tx_signed = true;
3093                         // We can't broadcast our HTLC transactions while the commitment transaction is
3094                         // unconfirmed. We'll delay doing so until we detect the confirmed commitment in
3095                         // `transactions_confirmed`.
3096                         if !self.onchain_tx_handler.opt_anchors() {
3097                                 // Because we're broadcasting a commitment transaction, we should construct the package
3098                                 // assuming it gets confirmed in the next block. Sadly, we have code which considers
3099                                 // "not yet confirmed" things as discardable, so we cannot do that here.
3100                                 let (mut new_outpoints, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
3101                                 let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &commitment_tx);
3102                                 if !new_outputs.is_empty() {
3103                                         watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
3104                                 }
3105                                 claimable_outpoints.append(&mut new_outpoints);
3106                         }
3107                 }
3108
3109                 // Find which on-chain events have reached their confirmation threshold.
3110                 let onchain_events_awaiting_threshold_conf =
3111                         self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
3112                 let mut onchain_events_reaching_threshold_conf = Vec::new();
3113                 for entry in onchain_events_awaiting_threshold_conf {
3114                         if entry.has_reached_confirmation_threshold(&self.best_block) {
3115                                 onchain_events_reaching_threshold_conf.push(entry);
3116                         } else {
3117                                 self.onchain_events_awaiting_threshold_conf.push(entry);
3118                         }
3119                 }
3120
3121                 // Used to check for duplicate HTLC resolutions.
3122                 #[cfg(debug_assertions)]
3123                 let unmatured_htlcs: Vec<_> = self.onchain_events_awaiting_threshold_conf
3124                         .iter()
3125                         .filter_map(|entry| match &entry.event {
3126                                 OnchainEvent::HTLCUpdate { source, .. } => Some(source),
3127                                 _ => None,
3128                         })
3129                         .collect();
3130                 #[cfg(debug_assertions)]
3131                 let mut matured_htlcs = Vec::new();
3132
3133                 // Produce actionable events from on-chain events having reached their threshold.
3134                 for entry in onchain_events_reaching_threshold_conf.drain(..) {
3135                         match entry.event {
3136                                 OnchainEvent::HTLCUpdate { ref source, payment_hash, htlc_value_satoshis, commitment_tx_output_idx } => {
3137                                         // Check for duplicate HTLC resolutions.
3138                                         #[cfg(debug_assertions)]
3139                                         {
3140                                                 debug_assert!(
3141                                                         unmatured_htlcs.iter().find(|&htlc| htlc == &source).is_none(),
3142                                                         "An unmature HTLC transaction conflicts with a maturing one; failed to \
3143                                                          call either transaction_unconfirmed for the conflicting transaction \
3144                                                          or block_disconnected for a block containing it.");
3145                                                 debug_assert!(
3146                                                         matured_htlcs.iter().find(|&htlc| htlc == source).is_none(),
3147                                                         "A matured HTLC transaction conflicts with a maturing one; failed to \
3148                                                          call either transaction_unconfirmed for the conflicting transaction \
3149                                                          or block_disconnected for a block containing it.");
3150                                                 matured_htlcs.push(source.clone());
3151                                         }
3152
3153                                         log_debug!(logger, "HTLC {} failure update in {} has got enough confirmations to be passed upstream",
3154                                                 log_bytes!(payment_hash.0), entry.txid);
3155                                         self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
3156                                                 payment_hash,
3157                                                 payment_preimage: None,
3158                                                 source: source.clone(),
3159                                                 htlc_value_satoshis,
3160                                         }));
3161                                         self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC {
3162                                                 commitment_tx_output_idx,
3163                                                 resolving_txid: Some(entry.txid),
3164                                                 resolving_tx: entry.transaction,
3165                                                 payment_preimage: None,
3166                                         });
3167                                 },
3168                                 OnchainEvent::MaturingOutput { descriptor } => {
3169                                         log_debug!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
3170                                         self.pending_events.push(Event::SpendableOutputs {
3171                                                 outputs: vec![descriptor]
3172                                         });
3173                                         self.spendable_txids_confirmed.push(entry.txid);
3174                                 },
3175                                 OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, preimage, .. } => {
3176                                         self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC {
3177                                                 commitment_tx_output_idx: Some(commitment_tx_output_idx),
3178                                                 resolving_txid: Some(entry.txid),
3179                                                 resolving_tx: entry.transaction,
3180                                                 payment_preimage: preimage,
3181                                         });
3182                                 },
3183                                 OnchainEvent::FundingSpendConfirmation { commitment_tx_to_counterparty_output, .. } => {
3184                                         self.funding_spend_confirmed = Some(entry.txid);
3185                                         self.confirmed_commitment_tx_counterparty_output = commitment_tx_to_counterparty_output;
3186                                 },
3187                         }
3188                 }
3189
3190                 self.onchain_tx_handler.update_claims_view_from_requests(claimable_outpoints, conf_height, self.best_block.height(), broadcaster, fee_estimator, logger);
3191                 self.onchain_tx_handler.update_claims_view_from_matched_txn(&txn_matched, conf_height, conf_hash, self.best_block.height(), broadcaster, fee_estimator, logger);
3192
3193                 // Determine new outputs to watch by comparing against previously known outputs to watch,
3194                 // updating the latter in the process.
3195                 watch_outputs.retain(|&(ref txid, ref txouts)| {
3196                         let idx_and_scripts = txouts.iter().map(|o| (o.0, o.1.script_pubkey.clone())).collect();
3197                         self.outputs_to_watch.insert(txid.clone(), idx_and_scripts).is_none()
3198                 });
3199                 #[cfg(test)]
3200                 {
3201                         // If we see a transaction for which we registered outputs previously,
3202                         // make sure the registered scriptpubkey at the expected index match
3203                         // the actual transaction output one. We failed this case before #653.
3204                         for tx in &txn_matched {
3205                                 if let Some(outputs) = self.get_outputs_to_watch().get(&tx.txid()) {
3206                                         for idx_and_script in outputs.iter() {
3207                                                 assert!((idx_and_script.0 as usize) < tx.output.len());
3208                                                 assert_eq!(tx.output[idx_and_script.0 as usize].script_pubkey, idx_and_script.1);
3209                                         }
3210                                 }
3211                         }
3212                 }
3213                 watch_outputs
3214         }
3215
3216         pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, height: u32, broadcaster: B, fee_estimator: F, logger: L)
3217                 where B::Target: BroadcasterInterface,
3218                       F::Target: FeeEstimator,
3219                       L::Target: Logger,
3220         {
3221                 log_trace!(logger, "Block {} at height {} disconnected", header.block_hash(), height);
3222
3223                 //We may discard:
3224                 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
3225                 //- maturing spendable output has transaction paying us has been disconnected
3226                 self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height < height);
3227
3228                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
3229                 self.onchain_tx_handler.block_disconnected(height, broadcaster, &bounded_fee_estimator, logger);
3230
3231                 self.best_block = BestBlock::new(header.prev_blockhash, height - 1);
3232         }
3233
3234         fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
3235                 &mut self,
3236                 txid: &Txid,
3237                 broadcaster: B,
3238                 fee_estimator: &LowerBoundedFeeEstimator<F>,
3239                 logger: L,
3240         ) where
3241                 B::Target: BroadcasterInterface,
3242                 F::Target: FeeEstimator,
3243                 L::Target: Logger,
3244         {
3245                 let mut removed_height = None;
3246                 for entry in self.onchain_events_awaiting_threshold_conf.iter() {
3247                         if entry.txid == *txid {
3248                                 removed_height = Some(entry.height);
3249                                 break;
3250                         }
3251                 }
3252
3253                 if let Some(removed_height) = removed_height {
3254                         log_info!(logger, "transaction_unconfirmed of txid {} implies height {} was reorg'd out", txid, removed_height);
3255                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| if entry.height >= removed_height {
3256                                 log_info!(logger, "Transaction {} reorg'd out", entry.txid);
3257                                 false
3258                         } else { true });
3259                 }
3260
3261                 debug_assert!(!self.onchain_events_awaiting_threshold_conf.iter().any(|ref entry| entry.txid == *txid));
3262
3263                 self.onchain_tx_handler.transaction_unconfirmed(txid, broadcaster, fee_estimator, logger);
3264         }
3265
3266         /// Filters a block's `txdata` for transactions spending watched outputs or for any child
3267         /// transactions thereof.
3268         fn filter_block<'a>(&self, txdata: &TransactionData<'a>) -> Vec<&'a Transaction> {
3269                 let mut matched_txn = HashSet::new();
3270                 txdata.iter().filter(|&&(_, tx)| {
3271                         let mut matches = self.spends_watched_output(tx);
3272                         for input in tx.input.iter() {
3273                                 if matches { break; }
3274                                 if matched_txn.contains(&input.previous_output.txid) {
3275                                         matches = true;
3276                                 }
3277                         }
3278                         if matches {
3279                                 matched_txn.insert(tx.txid());
3280                         }
3281                         matches
3282                 }).map(|(_, tx)| *tx).collect()
3283         }
3284
3285         /// Checks if a given transaction spends any watched outputs.
3286         fn spends_watched_output(&self, tx: &Transaction) -> bool {
3287                 for input in tx.input.iter() {
3288                         if let Some(outputs) = self.get_outputs_to_watch().get(&input.previous_output.txid) {
3289                                 for (idx, _script_pubkey) in outputs.iter() {
3290                                         if *idx == input.previous_output.vout {
3291                                                 #[cfg(test)]
3292                                                 {
3293                                                         // If the expected script is a known type, check that the witness
3294                                                         // appears to be spending the correct type (ie that the match would
3295                                                         // actually succeed in BIP 158/159-style filters).
3296                                                         if _script_pubkey.is_v0_p2wsh() {
3297                                                                 if input.witness.last().unwrap().to_vec() == deliberately_bogus_accepted_htlc_witness_program() {
3298                                                                         // In at least one test we use a deliberately bogus witness
3299                                                                         // script which hit an old panic. Thus, we check for that here
3300                                                                         // and avoid the assert if its the expected bogus script.
3301                                                                         return true;
3302                                                                 }
3303
3304                                                                 assert_eq!(&bitcoin::Address::p2wsh(&Script::from(input.witness.last().unwrap().to_vec()), bitcoin::Network::Bitcoin).script_pubkey(), _script_pubkey);
3305                                                         } else if _script_pubkey.is_v0_p2wpkh() {
3306                                                                 assert_eq!(&bitcoin::Address::p2wpkh(&bitcoin::PublicKey::from_slice(&input.witness.last().unwrap()).unwrap(), bitcoin::Network::Bitcoin).unwrap().script_pubkey(), _script_pubkey);
3307                                                         } else { panic!(); }
3308                                                 }
3309                                                 return true;
3310                                         }
3311                                 }
3312                         }
3313                 }
3314
3315                 false
3316         }
3317
3318         fn should_broadcast_holder_commitment_txn<L: Deref>(&self, logger: &L) -> bool where L::Target: Logger {
3319                 // There's no need to broadcast our commitment transaction if we've seen one confirmed (even
3320                 // with 1 confirmation) as it'll be rejected as duplicate/conflicting.
3321                 if self.funding_spend_confirmed.is_some() ||
3322                         self.onchain_events_awaiting_threshold_conf.iter().find(|event| match event.event {
3323                                 OnchainEvent::FundingSpendConfirmation { .. } => true,
3324                                 _ => false,
3325                         }).is_some()
3326                 {
3327                         return false;
3328                 }
3329                 // We need to consider all HTLCs which are:
3330                 //  * in any unrevoked counterparty commitment transaction, as they could broadcast said
3331                 //    transactions and we'd end up in a race, or
3332                 //  * are in our latest holder commitment transaction, as this is the thing we will
3333                 //    broadcast if we go on-chain.
3334                 // Note that we consider HTLCs which were below dust threshold here - while they don't
3335                 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
3336                 // to the source, and if we don't fail the channel we will have to ensure that the next
3337                 // updates that peer sends us are update_fails, failing the channel if not. It's probably
3338                 // easier to just fail the channel as this case should be rare enough anyway.
3339                 let height = self.best_block.height();
3340                 macro_rules! scan_commitment {
3341                         ($htlcs: expr, $holder_tx: expr) => {
3342                                 for ref htlc in $htlcs {
3343                                         // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
3344                                         // chain with enough room to claim the HTLC without our counterparty being able to
3345                                         // time out the HTLC first.
3346                                         // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
3347                                         // concern is being able to claim the corresponding inbound HTLC (on another
3348                                         // channel) before it expires. In fact, we don't even really care if our
3349                                         // counterparty here claims such an outbound HTLC after it expired as long as we
3350                                         // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
3351                                         // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
3352                                         // we give ourselves a few blocks of headroom after expiration before going
3353                                         // on-chain for an expired HTLC.
3354                                         // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
3355                                         // from us until we've reached the point where we go on-chain with the
3356                                         // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
3357                                         // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
3358                                         //  aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
3359                                         //      inbound_cltv == height + CLTV_CLAIM_BUFFER
3360                                         //      outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
3361                                         //      LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
3362                                         //      CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
3363                                         //      LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
3364                                         //  The final, above, condition is checked for statically in channelmanager
3365                                         //  with CHECK_CLTV_EXPIRY_SANITY_2.
3366                                         let htlc_outbound = $holder_tx == htlc.offered;
3367                                         if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
3368                                            (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
3369                                                 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
3370                                                 return true;
3371                                         }
3372                                 }
3373                         }
3374                 }
3375
3376                 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
3377
3378                 if let Some(ref txid) = self.current_counterparty_commitment_txid {
3379                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
3380                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
3381                         }
3382                 }
3383                 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
3384                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
3385                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
3386                         }
3387                 }
3388
3389                 false
3390         }
3391
3392         /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a holder
3393         /// or counterparty commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
3394         fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, block_hash: &BlockHash, logger: &L) where L::Target: Logger {
3395                 'outer_loop: for input in &tx.input {
3396                         let mut payment_data = None;
3397                         let htlc_claim = HTLCClaim::from_witness(&input.witness);
3398                         let revocation_sig_claim = htlc_claim == Some(HTLCClaim::Revocation);
3399                         let accepted_preimage_claim = htlc_claim == Some(HTLCClaim::AcceptedPreimage);
3400                         #[cfg(not(fuzzing))]
3401                         let accepted_timeout_claim = htlc_claim == Some(HTLCClaim::AcceptedTimeout);
3402                         let offered_preimage_claim = htlc_claim == Some(HTLCClaim::OfferedPreimage);
3403                         #[cfg(not(fuzzing))]
3404                         let offered_timeout_claim = htlc_claim == Some(HTLCClaim::OfferedTimeout);
3405
3406                         let mut payment_preimage = PaymentPreimage([0; 32]);
3407                         if offered_preimage_claim || accepted_preimage_claim {
3408                                 payment_preimage.0.copy_from_slice(input.witness.second_to_last().unwrap());
3409                         }
3410
3411                         macro_rules! log_claim {
3412                                 ($tx_info: expr, $holder_tx: expr, $htlc: expr, $source_avail: expr) => {
3413                                         let outbound_htlc = $holder_tx == $htlc.offered;
3414                                         // HTLCs must either be claimed by a matching script type or through the
3415                                         // revocation path:
3416                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
3417                                         debug_assert!(!$htlc.offered || offered_preimage_claim || offered_timeout_claim || revocation_sig_claim);
3418                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
3419                                         debug_assert!($htlc.offered || accepted_preimage_claim || accepted_timeout_claim || revocation_sig_claim);
3420                                         // Further, only exactly one of the possible spend paths should have been
3421                                         // matched by any HTLC spend:
3422                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
3423                                         debug_assert_eq!(accepted_preimage_claim as u8 + accepted_timeout_claim as u8 +
3424                                                          offered_preimage_claim as u8 + offered_timeout_claim as u8 +
3425                                                          revocation_sig_claim as u8, 1);
3426                                         if ($holder_tx && revocation_sig_claim) ||
3427                                                         (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
3428                                                 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
3429                                                         $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
3430                                                         if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
3431                                                         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" });
3432                                         } else {
3433                                                 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
3434                                                         $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
3435                                                         if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
3436                                                         if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
3437                                         }
3438                                 }
3439                         }
3440
3441                         macro_rules! check_htlc_valid_counterparty {
3442                                 ($counterparty_txid: expr, $htlc_output: expr) => {
3443                                         if let Some(txid) = $counterparty_txid {
3444                                                 for &(ref pending_htlc, ref pending_source) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
3445                                                         if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
3446                                                                 if let &Some(ref source) = pending_source {
3447                                                                         log_claim!("revoked counterparty commitment tx", false, pending_htlc, true);
3448                                                                         payment_data = Some(((**source).clone(), $htlc_output.payment_hash, $htlc_output.amount_msat));
3449                                                                         break;
3450                                                                 }
3451                                                         }
3452                                                 }
3453                                         }
3454                                 }
3455                         }
3456
3457                         macro_rules! scan_commitment {
3458                                 ($htlcs: expr, $tx_info: expr, $holder_tx: expr) => {
3459                                         for (ref htlc_output, source_option) in $htlcs {
3460                                                 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
3461                                                         if let Some(ref source) = source_option {
3462                                                                 log_claim!($tx_info, $holder_tx, htlc_output, true);
3463                                                                 // We have a resolution of an HTLC either from one of our latest
3464                                                                 // holder commitment transactions or an unrevoked counterparty commitment
3465                                                                 // transaction. This implies we either learned a preimage, the HTLC
3466                                                                 // has timed out, or we screwed up. In any case, we should now
3467                                                                 // resolve the source HTLC with the original sender.
3468                                                                 payment_data = Some(((*source).clone(), htlc_output.payment_hash, htlc_output.amount_msat));
3469                                                         } else if !$holder_tx {
3470                                                                 check_htlc_valid_counterparty!(self.current_counterparty_commitment_txid, htlc_output);
3471                                                                 if payment_data.is_none() {
3472                                                                         check_htlc_valid_counterparty!(self.prev_counterparty_commitment_txid, htlc_output);
3473                                                                 }
3474                                                         }
3475                                                         if payment_data.is_none() {
3476                                                                 log_claim!($tx_info, $holder_tx, htlc_output, false);
3477                                                                 let outbound_htlc = $holder_tx == htlc_output.offered;
3478                                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3479                                                                         txid: tx.txid(), height, block_hash: Some(*block_hash), transaction: Some(tx.clone()),
3480                                                                         event: OnchainEvent::HTLCSpendConfirmation {
3481                                                                                 commitment_tx_output_idx: input.previous_output.vout,
3482                                                                                 preimage: if accepted_preimage_claim || offered_preimage_claim {
3483                                                                                         Some(payment_preimage) } else { None },
3484                                                                                 // If this is a payment to us (ie !outbound_htlc), wait for
3485                                                                                 // the CSV delay before dropping the HTLC from claimable
3486                                                                                 // balance if the claim was an HTLC-Success transaction (ie
3487                                                                                 // accepted_preimage_claim).
3488                                                                                 on_to_local_output_csv: if accepted_preimage_claim && !outbound_htlc {
3489                                                                                         Some(self.on_holder_tx_csv) } else { None },
3490                                                                         },
3491                                                                 });
3492                                                                 continue 'outer_loop;
3493                                                         }
3494                                                 }
3495                                         }
3496                                 }
3497                         }
3498
3499                         if input.previous_output.txid == self.current_holder_commitment_tx.txid {
3500                                 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
3501                                         "our latest holder commitment tx", true);
3502                         }
3503                         if let Some(ref prev_holder_signed_commitment_tx) = self.prev_holder_signed_commitment_tx {
3504                                 if input.previous_output.txid == prev_holder_signed_commitment_tx.txid {
3505                                         scan_commitment!(prev_holder_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
3506                                                 "our previous holder commitment tx", true);
3507                                 }
3508                         }
3509                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(&input.previous_output.txid) {
3510                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
3511                                         "counterparty commitment tx", false);
3512                         }
3513
3514                         // Check that scan_commitment, above, decided there is some source worth relaying an
3515                         // HTLC resolution backwards to and figure out whether we learned a preimage from it.
3516                         if let Some((source, payment_hash, amount_msat)) = payment_data {
3517                                 if accepted_preimage_claim {
3518                                         if !self.pending_monitor_events.iter().any(
3519                                                 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update { upd.source == source } else { false }) {
3520                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3521                                                         txid: tx.txid(),
3522                                                         height,
3523                                                         block_hash: Some(*block_hash),
3524                                                         transaction: Some(tx.clone()),
3525                                                         event: OnchainEvent::HTLCSpendConfirmation {
3526                                                                 commitment_tx_output_idx: input.previous_output.vout,
3527                                                                 preimage: Some(payment_preimage),
3528                                                                 on_to_local_output_csv: None,
3529                                                         },
3530                                                 });
3531                                                 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
3532                                                         source,
3533                                                         payment_preimage: Some(payment_preimage),
3534                                                         payment_hash,
3535                                                         htlc_value_satoshis: Some(amount_msat / 1000),
3536                                                 }));
3537                                         }
3538                                 } else if offered_preimage_claim {
3539                                         if !self.pending_monitor_events.iter().any(
3540                                                 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update {
3541                                                         upd.source == source
3542                                                 } else { false }) {
3543                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3544                                                         txid: tx.txid(),
3545                                                         transaction: Some(tx.clone()),
3546                                                         height,
3547                                                         block_hash: Some(*block_hash),
3548                                                         event: OnchainEvent::HTLCSpendConfirmation {
3549                                                                 commitment_tx_output_idx: input.previous_output.vout,
3550                                                                 preimage: Some(payment_preimage),
3551                                                                 on_to_local_output_csv: None,
3552                                                         },
3553                                                 });
3554                                                 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
3555                                                         source,
3556                                                         payment_preimage: Some(payment_preimage),
3557                                                         payment_hash,
3558                                                         htlc_value_satoshis: Some(amount_msat / 1000),
3559                                                 }));
3560                                         }
3561                                 } else {
3562                                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
3563                                                 if entry.height != height { return true; }
3564                                                 match entry.event {
3565                                                         OnchainEvent::HTLCUpdate { source: ref htlc_source, .. } => {
3566                                                                 *htlc_source != source
3567                                                         },
3568                                                         _ => true,
3569                                                 }
3570                                         });
3571                                         let entry = OnchainEventEntry {
3572                                                 txid: tx.txid(),
3573                                                 transaction: Some(tx.clone()),
3574                                                 height,
3575                                                 block_hash: Some(*block_hash),
3576                                                 event: OnchainEvent::HTLCUpdate {
3577                                                         source, payment_hash,
3578                                                         htlc_value_satoshis: Some(amount_msat / 1000),
3579                                                         commitment_tx_output_idx: Some(input.previous_output.vout),
3580                                                 },
3581                                         };
3582                                         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());
3583                                         self.onchain_events_awaiting_threshold_conf.push(entry);
3584                                 }
3585                         }
3586                 }
3587         }
3588
3589         /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
3590         fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, block_hash: &BlockHash, logger: &L) where L::Target: Logger {
3591                 let mut spendable_output = None;
3592                 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
3593                         if i > ::core::u16::MAX as usize {
3594                                 // While it is possible that an output exists on chain which is greater than the
3595                                 // 2^16th output in a given transaction, this is only possible if the output is not
3596                                 // in a lightning transaction and was instead placed there by some third party who
3597                                 // wishes to give us money for no reason.
3598                                 // Namely, any lightning transactions which we pre-sign will never have anywhere
3599                                 // near 2^16 outputs both because such transactions must have ~2^16 outputs who's
3600                                 // scripts are not longer than one byte in length and because they are inherently
3601                                 // non-standard due to their size.
3602                                 // Thus, it is completely safe to ignore such outputs, and while it may result in
3603                                 // us ignoring non-lightning fund to us, that is only possible if someone fills
3604                                 // nearly a full block with garbage just to hit this case.
3605                                 continue;
3606                         }
3607                         if outp.script_pubkey == self.destination_script {
3608                                 spendable_output =  Some(SpendableOutputDescriptor::StaticOutput {
3609                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3610                                         output: outp.clone(),
3611                                 });
3612                                 break;
3613                         }
3614                         if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
3615                                 if broadcasted_holder_revokable_script.0 == outp.script_pubkey {
3616                                         spendable_output =  Some(SpendableOutputDescriptor::DelayedPaymentOutput(DelayedPaymentOutputDescriptor {
3617                                                 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3618                                                 per_commitment_point: broadcasted_holder_revokable_script.1,
3619                                                 to_self_delay: self.on_holder_tx_csv,
3620                                                 output: outp.clone(),
3621                                                 revocation_pubkey: broadcasted_holder_revokable_script.2.clone(),
3622                                                 channel_keys_id: self.channel_keys_id,
3623                                                 channel_value_satoshis: self.channel_value_satoshis,
3624                                         }));
3625                                         break;
3626                                 }
3627                         }
3628                         if self.counterparty_payment_script == outp.script_pubkey {
3629                                 spendable_output = Some(SpendableOutputDescriptor::StaticPaymentOutput(StaticPaymentOutputDescriptor {
3630                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3631                                         output: outp.clone(),
3632                                         channel_keys_id: self.channel_keys_id,
3633                                         channel_value_satoshis: self.channel_value_satoshis,
3634                                 }));
3635                                 break;
3636                         }
3637                         if self.shutdown_script.as_ref() == Some(&outp.script_pubkey) {
3638                                 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
3639                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3640                                         output: outp.clone(),
3641                                 });
3642                                 break;
3643                         }
3644                 }
3645                 if let Some(spendable_output) = spendable_output {
3646                         let entry = OnchainEventEntry {
3647                                 txid: tx.txid(),
3648                                 transaction: Some(tx.clone()),
3649                                 height,
3650                                 block_hash: Some(*block_hash),
3651                                 event: OnchainEvent::MaturingOutput { descriptor: spendable_output.clone() },
3652                         };
3653                         log_info!(logger, "Received spendable output {}, spendable at height {}", log_spendable!(spendable_output), entry.confirmation_threshold());
3654                         self.onchain_events_awaiting_threshold_conf.push(entry);
3655                 }
3656         }
3657 }
3658
3659 impl<Signer: WriteableEcdsaChannelSigner, T: Deref, F: Deref, L: Deref> chain::Listen for (ChannelMonitor<Signer>, T, F, L)
3660 where
3661         T::Target: BroadcasterInterface,
3662         F::Target: FeeEstimator,
3663         L::Target: Logger,
3664 {
3665         fn filtered_block_connected(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
3666                 self.0.block_connected(header, txdata, height, &*self.1, &*self.2, &*self.3);
3667         }
3668
3669         fn block_disconnected(&self, header: &BlockHeader, height: u32) {
3670                 self.0.block_disconnected(header, height, &*self.1, &*self.2, &*self.3);
3671         }
3672 }
3673
3674 impl<Signer: WriteableEcdsaChannelSigner, T: Deref, F: Deref, L: Deref> chain::Confirm for (ChannelMonitor<Signer>, T, F, L)
3675 where
3676         T::Target: BroadcasterInterface,
3677         F::Target: FeeEstimator,
3678         L::Target: Logger,
3679 {
3680         fn transactions_confirmed(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
3681                 self.0.transactions_confirmed(header, txdata, height, &*self.1, &*self.2, &*self.3);
3682         }
3683
3684         fn transaction_unconfirmed(&self, txid: &Txid) {
3685                 self.0.transaction_unconfirmed(txid, &*self.1, &*self.2, &*self.3);
3686         }
3687
3688         fn best_block_updated(&self, header: &BlockHeader, height: u32) {
3689                 self.0.best_block_updated(header, height, &*self.1, &*self.2, &*self.3);
3690         }
3691
3692         fn get_relevant_txids(&self) -> Vec<(Txid, Option<BlockHash>)> {
3693                 self.0.get_relevant_txids()
3694         }
3695 }
3696
3697 const MAX_ALLOC_SIZE: usize = 64*1024;
3698
3699 impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP)>
3700                 for (BlockHash, ChannelMonitor<SP::Signer>) {
3701         fn read<R: io::Read>(reader: &mut R, args: (&'a ES, &'b SP)) -> Result<Self, DecodeError> {
3702                 macro_rules! unwrap_obj {
3703                         ($key: expr) => {
3704                                 match $key {
3705                                         Ok(res) => res,
3706                                         Err(_) => return Err(DecodeError::InvalidValue),
3707                                 }
3708                         }
3709                 }
3710
3711                 let (entropy_source, signer_provider) = args;
3712
3713                 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
3714
3715                 let latest_update_id: u64 = Readable::read(reader)?;
3716                 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
3717
3718                 let destination_script = Readable::read(reader)?;
3719                 let broadcasted_holder_revokable_script = match <u8 as Readable>::read(reader)? {
3720                         0 => {
3721                                 let revokable_address = Readable::read(reader)?;
3722                                 let per_commitment_point = Readable::read(reader)?;
3723                                 let revokable_script = Readable::read(reader)?;
3724                                 Some((revokable_address, per_commitment_point, revokable_script))
3725                         },
3726                         1 => { None },
3727                         _ => return Err(DecodeError::InvalidValue),
3728                 };
3729                 let counterparty_payment_script = Readable::read(reader)?;
3730                 let shutdown_script = {
3731                         let script = <Script as Readable>::read(reader)?;
3732                         if script.is_empty() { None } else { Some(script) }
3733                 };
3734
3735                 let channel_keys_id = Readable::read(reader)?;
3736                 let holder_revocation_basepoint = Readable::read(reader)?;
3737                 // Technically this can fail and serialize fail a round-trip, but only for serialization of
3738                 // barely-init'd ChannelMonitors that we can't do anything with.
3739                 let outpoint = OutPoint {
3740                         txid: Readable::read(reader)?,
3741                         index: Readable::read(reader)?,
3742                 };
3743                 let funding_info = (outpoint, Readable::read(reader)?);
3744                 let current_counterparty_commitment_txid = Readable::read(reader)?;
3745                 let prev_counterparty_commitment_txid = Readable::read(reader)?;
3746
3747                 let counterparty_commitment_params = Readable::read(reader)?;
3748                 let funding_redeemscript = Readable::read(reader)?;
3749                 let channel_value_satoshis = Readable::read(reader)?;
3750
3751                 let their_cur_per_commitment_points = {
3752                         let first_idx = <U48 as Readable>::read(reader)?.0;
3753                         if first_idx == 0 {
3754                                 None
3755                         } else {
3756                                 let first_point = Readable::read(reader)?;
3757                                 let second_point_slice: [u8; 33] = Readable::read(reader)?;
3758                                 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
3759                                         Some((first_idx, first_point, None))
3760                                 } else {
3761                                         Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
3762                                 }
3763                         }
3764                 };
3765
3766                 let on_holder_tx_csv: u16 = Readable::read(reader)?;
3767
3768                 let commitment_secrets = Readable::read(reader)?;
3769
3770                 macro_rules! read_htlc_in_commitment {
3771                         () => {
3772                                 {
3773                                         let offered: bool = Readable::read(reader)?;
3774                                         let amount_msat: u64 = Readable::read(reader)?;
3775                                         let cltv_expiry: u32 = Readable::read(reader)?;
3776                                         let payment_hash: PaymentHash = Readable::read(reader)?;
3777                                         let transaction_output_index: Option<u32> = Readable::read(reader)?;
3778
3779                                         HTLCOutputInCommitment {
3780                                                 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
3781                                         }
3782                                 }
3783                         }
3784                 }
3785
3786                 let counterparty_claimable_outpoints_len: u64 = Readable::read(reader)?;
3787                 let mut counterparty_claimable_outpoints = HashMap::with_capacity(cmp::min(counterparty_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
3788                 for _ in 0..counterparty_claimable_outpoints_len {
3789                         let txid: Txid = Readable::read(reader)?;
3790                         let htlcs_count: u64 = Readable::read(reader)?;
3791                         let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
3792                         for _ in 0..htlcs_count {
3793                                 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
3794                         }
3795                         if let Some(_) = counterparty_claimable_outpoints.insert(txid, htlcs) {
3796                                 return Err(DecodeError::InvalidValue);
3797                         }
3798                 }
3799
3800                 let counterparty_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
3801                 let mut counterparty_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(counterparty_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
3802                 for _ in 0..counterparty_commitment_txn_on_chain_len {
3803                         let txid: Txid = Readable::read(reader)?;
3804                         let commitment_number = <U48 as Readable>::read(reader)?.0;
3805                         if let Some(_) = counterparty_commitment_txn_on_chain.insert(txid, commitment_number) {
3806                                 return Err(DecodeError::InvalidValue);
3807                         }
3808                 }
3809
3810                 let counterparty_hash_commitment_number_len: u64 = Readable::read(reader)?;
3811                 let mut counterparty_hash_commitment_number = HashMap::with_capacity(cmp::min(counterparty_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
3812                 for _ in 0..counterparty_hash_commitment_number_len {
3813                         let payment_hash: PaymentHash = Readable::read(reader)?;
3814                         let commitment_number = <U48 as Readable>::read(reader)?.0;
3815                         if let Some(_) = counterparty_hash_commitment_number.insert(payment_hash, commitment_number) {
3816                                 return Err(DecodeError::InvalidValue);
3817                         }
3818                 }
3819
3820                 let mut prev_holder_signed_commitment_tx: Option<HolderSignedTx> =
3821                         match <u8 as Readable>::read(reader)? {
3822                                 0 => None,
3823                                 1 => {
3824                                         Some(Readable::read(reader)?)
3825                                 },
3826                                 _ => return Err(DecodeError::InvalidValue),
3827                         };
3828                 let mut current_holder_commitment_tx: HolderSignedTx = Readable::read(reader)?;
3829
3830                 let current_counterparty_commitment_number = <U48 as Readable>::read(reader)?.0;
3831                 let current_holder_commitment_number = <U48 as Readable>::read(reader)?.0;
3832
3833                 let payment_preimages_len: u64 = Readable::read(reader)?;
3834                 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
3835                 for _ in 0..payment_preimages_len {
3836                         let preimage: PaymentPreimage = Readable::read(reader)?;
3837                         let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
3838                         if let Some(_) = payment_preimages.insert(hash, preimage) {
3839                                 return Err(DecodeError::InvalidValue);
3840                         }
3841                 }
3842
3843                 let pending_monitor_events_len: u64 = Readable::read(reader)?;
3844                 let mut pending_monitor_events = Some(
3845                         Vec::with_capacity(cmp::min(pending_monitor_events_len as usize, MAX_ALLOC_SIZE / (32 + 8*3))));
3846                 for _ in 0..pending_monitor_events_len {
3847                         let ev = match <u8 as Readable>::read(reader)? {
3848                                 0 => MonitorEvent::HTLCEvent(Readable::read(reader)?),
3849                                 1 => MonitorEvent::CommitmentTxConfirmed(funding_info.0),
3850                                 _ => return Err(DecodeError::InvalidValue)
3851                         };
3852                         pending_monitor_events.as_mut().unwrap().push(ev);
3853                 }
3854
3855                 let pending_events_len: u64 = Readable::read(reader)?;
3856                 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Event>()));
3857                 for _ in 0..pending_events_len {
3858                         if let Some(event) = MaybeReadable::read(reader)? {
3859                                 pending_events.push(event);
3860                         }
3861                 }
3862
3863                 let best_block = BestBlock::new(Readable::read(reader)?, Readable::read(reader)?);
3864
3865                 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
3866                 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
3867                 for _ in 0..waiting_threshold_conf_len {
3868                         if let Some(val) = MaybeReadable::read(reader)? {
3869                                 onchain_events_awaiting_threshold_conf.push(val);
3870                         }
3871                 }
3872
3873                 let outputs_to_watch_len: u64 = Readable::read(reader)?;
3874                 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>>())));
3875                 for _ in 0..outputs_to_watch_len {
3876                         let txid = Readable::read(reader)?;
3877                         let outputs_len: u64 = Readable::read(reader)?;
3878                         let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / (mem::size_of::<u32>() + mem::size_of::<Script>())));
3879                         for _ in 0..outputs_len {
3880                                 outputs.push((Readable::read(reader)?, Readable::read(reader)?));
3881                         }
3882                         if let Some(_) = outputs_to_watch.insert(txid, outputs) {
3883                                 return Err(DecodeError::InvalidValue);
3884                         }
3885                 }
3886                 let onchain_tx_handler: OnchainTxHandler<SP::Signer> = ReadableArgs::read(
3887                         reader, (entropy_source, signer_provider, channel_value_satoshis, channel_keys_id)
3888                 )?;
3889
3890                 let lockdown_from_offchain = Readable::read(reader)?;
3891                 let holder_tx_signed = Readable::read(reader)?;
3892
3893                 if let Some(prev_commitment_tx) = prev_holder_signed_commitment_tx.as_mut() {
3894                         let prev_holder_value = onchain_tx_handler.get_prev_holder_commitment_to_self_value();
3895                         if prev_holder_value.is_none() { return Err(DecodeError::InvalidValue); }
3896                         if prev_commitment_tx.to_self_value_sat == u64::max_value() {
3897                                 prev_commitment_tx.to_self_value_sat = prev_holder_value.unwrap();
3898                         } else if prev_commitment_tx.to_self_value_sat != prev_holder_value.unwrap() {
3899                                 return Err(DecodeError::InvalidValue);
3900                         }
3901                 }
3902
3903                 let cur_holder_value = onchain_tx_handler.get_cur_holder_commitment_to_self_value();
3904                 if current_holder_commitment_tx.to_self_value_sat == u64::max_value() {
3905                         current_holder_commitment_tx.to_self_value_sat = cur_holder_value;
3906                 } else if current_holder_commitment_tx.to_self_value_sat != cur_holder_value {
3907                         return Err(DecodeError::InvalidValue);
3908                 }
3909
3910                 let mut funding_spend_confirmed = None;
3911                 let mut htlcs_resolved_on_chain = Some(Vec::new());
3912                 let mut funding_spend_seen = Some(false);
3913                 let mut counterparty_node_id = None;
3914                 let mut confirmed_commitment_tx_counterparty_output = None;
3915                 let mut spendable_txids_confirmed = Some(Vec::new());
3916                 let mut counterparty_fulfilled_htlcs = Some(HashMap::new());
3917                 read_tlv_fields!(reader, {
3918                         (1, funding_spend_confirmed, option),
3919                         (3, htlcs_resolved_on_chain, vec_type),
3920                         (5, pending_monitor_events, vec_type),
3921                         (7, funding_spend_seen, option),
3922                         (9, counterparty_node_id, option),
3923                         (11, confirmed_commitment_tx_counterparty_output, option),
3924                         (13, spendable_txids_confirmed, vec_type),
3925                         (15, counterparty_fulfilled_htlcs, option),
3926                 });
3927
3928                 Ok((best_block.block_hash(), ChannelMonitor::from_impl(ChannelMonitorImpl {
3929                         latest_update_id,
3930                         commitment_transaction_number_obscure_factor,
3931
3932                         destination_script,
3933                         broadcasted_holder_revokable_script,
3934                         counterparty_payment_script,
3935                         shutdown_script,
3936
3937                         channel_keys_id,
3938                         holder_revocation_basepoint,
3939                         funding_info,
3940                         current_counterparty_commitment_txid,
3941                         prev_counterparty_commitment_txid,
3942
3943                         counterparty_commitment_params,
3944                         funding_redeemscript,
3945                         channel_value_satoshis,
3946                         their_cur_per_commitment_points,
3947
3948                         on_holder_tx_csv,
3949
3950                         commitment_secrets,
3951                         counterparty_claimable_outpoints,
3952                         counterparty_commitment_txn_on_chain,
3953                         counterparty_hash_commitment_number,
3954                         counterparty_fulfilled_htlcs: counterparty_fulfilled_htlcs.unwrap(),
3955
3956                         prev_holder_signed_commitment_tx,
3957                         current_holder_commitment_tx,
3958                         current_counterparty_commitment_number,
3959                         current_holder_commitment_number,
3960
3961                         payment_preimages,
3962                         pending_monitor_events: pending_monitor_events.unwrap(),
3963                         pending_events,
3964
3965                         onchain_events_awaiting_threshold_conf,
3966                         outputs_to_watch,
3967
3968                         onchain_tx_handler,
3969
3970                         lockdown_from_offchain,
3971                         holder_tx_signed,
3972                         funding_spend_seen: funding_spend_seen.unwrap(),
3973                         funding_spend_confirmed,
3974                         confirmed_commitment_tx_counterparty_output,
3975                         htlcs_resolved_on_chain: htlcs_resolved_on_chain.unwrap(),
3976                         spendable_txids_confirmed: spendable_txids_confirmed.unwrap(),
3977
3978                         best_block,
3979                         counterparty_node_id,
3980                 })))
3981         }
3982 }
3983
3984 #[cfg(test)]
3985 mod tests {
3986         use bitcoin::blockdata::block::BlockHeader;
3987         use bitcoin::blockdata::script::{Script, Builder};
3988         use bitcoin::blockdata::opcodes;
3989         use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, EcdsaSighashType};
3990         use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
3991         use bitcoin::util::sighash;
3992         use bitcoin::hashes::Hash;
3993         use bitcoin::hashes::sha256::Hash as Sha256;
3994         use bitcoin::hashes::hex::FromHex;
3995         use bitcoin::hash_types::{BlockHash, Txid};
3996         use bitcoin::network::constants::Network;
3997         use bitcoin::secp256k1::{SecretKey,PublicKey};
3998         use bitcoin::secp256k1::Secp256k1;
3999
4000         use hex;
4001
4002         use crate::chain::chaininterface::LowerBoundedFeeEstimator;
4003
4004         use super::ChannelMonitorUpdateStep;
4005         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};
4006         use crate::chain::{BestBlock, Confirm};
4007         use crate::chain::channelmonitor::ChannelMonitor;
4008         use crate::chain::package::{weight_offered_htlc, weight_received_htlc, weight_revoked_offered_htlc, weight_revoked_received_htlc, WEIGHT_REVOKED_OUTPUT};
4009         use crate::chain::transaction::OutPoint;
4010         use crate::chain::keysinterface::InMemorySigner;
4011         use crate::ln::{PaymentPreimage, PaymentHash};
4012         use crate::ln::chan_utils;
4013         use crate::ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
4014         use crate::ln::channelmanager::{PaymentSendFailure, PaymentId};
4015         use crate::ln::functional_test_utils::*;
4016         use crate::ln::script::ShutdownScript;
4017         use crate::util::errors::APIError;
4018         use crate::util::events::{ClosureReason, MessageSendEventsProvider};
4019         use crate::util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};
4020         use crate::util::ser::{ReadableArgs, Writeable};
4021         use crate::sync::{Arc, Mutex};
4022         use crate::io;
4023         use bitcoin::{PackedLockTime, Sequence, TxMerkleNode, Witness};
4024         use crate::prelude::*;
4025
4026         fn do_test_funding_spend_refuses_updates(use_local_txn: bool) {
4027                 // Previously, monitor updates were allowed freely even after a funding-spend transaction
4028                 // confirmed. This would allow a race condition where we could receive a payment (including
4029                 // the counterparty revoking their broadcasted state!) and accept it without recourse as
4030                 // long as the ChannelMonitor receives the block first, the full commitment update dance
4031                 // occurs after the block is connected, and before the ChannelManager receives the block.
4032                 // Obviously this is an incredibly contrived race given the counterparty would be risking
4033                 // their full channel balance for it, but its worth fixing nonetheless as it makes the
4034                 // potential ChannelMonitor states simpler to reason about.
4035                 //
4036                 // This test checks said behavior, as well as ensuring a ChannelMonitorUpdate with multiple
4037                 // updates is handled correctly in such conditions.
4038                 let chanmon_cfgs = create_chanmon_cfgs(3);
4039                 let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
4040                 let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
4041                 let nodes = create_network(3, &node_cfgs, &node_chanmgrs);
4042                 let channel = create_announced_chan_between_nodes(&nodes, 0, 1);
4043                 create_announced_chan_between_nodes(&nodes, 1, 2);
4044
4045                 // Rebalance somewhat
4046                 send_payment(&nodes[0], &[&nodes[1]], 10_000_000);
4047
4048                 // First route two payments for testing at the end
4049                 let payment_preimage_1 = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 1_000_000).0;
4050                 let payment_preimage_2 = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 1_000_000).0;
4051
4052                 let local_txn = get_local_commitment_txn!(nodes[1], channel.2);
4053                 assert_eq!(local_txn.len(), 1);
4054                 let remote_txn = get_local_commitment_txn!(nodes[0], channel.2);
4055                 assert_eq!(remote_txn.len(), 3); // Commitment and two HTLC-Timeouts
4056                 check_spends!(remote_txn[1], remote_txn[0]);
4057                 check_spends!(remote_txn[2], remote_txn[0]);
4058                 let broadcast_tx = if use_local_txn { &local_txn[0] } else { &remote_txn[0] };
4059
4060                 // Connect a commitment transaction, but only to the ChainMonitor/ChannelMonitor. The
4061                 // channel is now closed, but the ChannelManager doesn't know that yet.
4062                 let new_header = BlockHeader {
4063                         version: 2, time: 0, bits: 0, nonce: 0,
4064                         prev_blockhash: nodes[0].best_block_info().0,
4065                         merkle_root: TxMerkleNode::all_zeros() };
4066                 let conf_height = nodes[0].best_block_info().1 + 1;
4067                 nodes[1].chain_monitor.chain_monitor.transactions_confirmed(&new_header,
4068                         &[(0, broadcast_tx)], conf_height);
4069
4070                 let (_, pre_update_monitor) = <(BlockHash, ChannelMonitor<InMemorySigner>)>::read(
4071                                                 &mut io::Cursor::new(&get_monitor!(nodes[1], channel.2).encode()),
4072                                                 (&nodes[1].keys_manager.backing, &nodes[1].keys_manager.backing)).unwrap();
4073
4074                 // If the ChannelManager tries to update the channel, however, the ChainMonitor will pass
4075                 // the update through to the ChannelMonitor which will refuse it (as the channel is closed).
4076                 let (route, payment_hash, _, payment_secret) = get_route_and_payment_hash!(nodes[1], nodes[0], 100_000);
4077                 unwrap_send_err!(nodes[1].node.send_payment(&route, payment_hash, &Some(payment_secret), PaymentId(payment_hash.0)),
4078                         true, APIError::ChannelUnavailable { ref err },
4079                         assert!(err.contains("ChannelMonitor storage failure")));
4080                 check_added_monitors!(nodes[1], 2); // After the failure we generate a close-channel monitor update
4081                 check_closed_broadcast!(nodes[1], true);
4082                 check_closed_event!(nodes[1], 1, ClosureReason::ProcessingError { err: "ChannelMonitor storage failure".to_string() });
4083
4084                 // Build a new ChannelMonitorUpdate which contains both the failing commitment tx update
4085                 // and provides the claim preimages for the two pending HTLCs. The first update generates
4086                 // an error, but the point of this test is to ensure the later updates are still applied.
4087                 let monitor_updates = nodes[1].chain_monitor.monitor_updates.lock().unwrap();
4088                 let mut replay_update = monitor_updates.get(&channel.2).unwrap().iter().rev().skip(1).next().unwrap().clone();
4089                 assert_eq!(replay_update.updates.len(), 1);
4090                 if let ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { .. } = replay_update.updates[0] {
4091                 } else { panic!(); }
4092                 replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_1 });
4093                 replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_2 });
4094
4095                 let broadcaster = TestBroadcaster::new(Arc::clone(&nodes[1].blocks));
4096                 assert!(
4097                         pre_update_monitor.update_monitor(&replay_update, &&broadcaster, &chanmon_cfgs[1].fee_estimator, &nodes[1].logger)
4098                         .is_err());
4099                 // Even though we error'd on the first update, we should still have generated an HTLC claim
4100                 // transaction
4101                 let txn_broadcasted = broadcaster.txn_broadcasted.lock().unwrap().split_off(0);
4102                 assert!(txn_broadcasted.len() >= 2);
4103                 let htlc_txn = txn_broadcasted.iter().filter(|tx| {
4104                         assert_eq!(tx.input.len(), 1);
4105                         tx.input[0].previous_output.txid == broadcast_tx.txid()
4106                 }).collect::<Vec<_>>();
4107                 assert_eq!(htlc_txn.len(), 2);
4108                 check_spends!(htlc_txn[0], broadcast_tx);
4109                 check_spends!(htlc_txn[1], broadcast_tx);
4110         }
4111         #[test]
4112         fn test_funding_spend_refuses_updates() {
4113                 do_test_funding_spend_refuses_updates(true);
4114                 do_test_funding_spend_refuses_updates(false);
4115         }
4116
4117         #[test]
4118         fn test_prune_preimages() {
4119                 let secp_ctx = Secp256k1::new();
4120                 let logger = Arc::new(TestLogger::new());
4121                 let broadcaster = Arc::new(TestBroadcaster {
4122                         txn_broadcasted: Mutex::new(Vec::new()),
4123                         blocks: Arc::new(Mutex::new(Vec::new()))
4124                 });
4125                 let fee_estimator = TestFeeEstimator { sat_per_kw: Mutex::new(253) };
4126
4127                 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
4128
4129                 let mut preimages = Vec::new();
4130                 {
4131                         for i in 0..20 {
4132                                 let preimage = PaymentPreimage([i; 32]);
4133                                 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
4134                                 preimages.push((preimage, hash));
4135                         }
4136                 }
4137
4138                 macro_rules! preimages_slice_to_htlc_outputs {
4139                         ($preimages_slice: expr) => {
4140                                 {
4141                                         let mut res = Vec::new();
4142                                         for (idx, preimage) in $preimages_slice.iter().enumerate() {
4143                                                 res.push((HTLCOutputInCommitment {
4144                                                         offered: true,
4145                                                         amount_msat: 0,
4146                                                         cltv_expiry: 0,
4147                                                         payment_hash: preimage.1.clone(),
4148                                                         transaction_output_index: Some(idx as u32),
4149                                                 }, None));
4150                                         }
4151                                         res
4152                                 }
4153                         }
4154                 }
4155                 macro_rules! preimages_to_holder_htlcs {
4156                         ($preimages_slice: expr) => {
4157                                 {
4158                                         let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
4159                                         let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
4160                                         res
4161                                 }
4162                         }
4163                 }
4164
4165                 macro_rules! test_preimages_exist {
4166                         ($preimages_slice: expr, $monitor: expr) => {
4167                                 for preimage in $preimages_slice {
4168                                         assert!($monitor.inner.lock().unwrap().payment_preimages.contains_key(&preimage.1));
4169                                 }
4170                         }
4171                 }
4172
4173                 let keys = InMemorySigner::new(
4174                         &secp_ctx,
4175                         SecretKey::from_slice(&[41; 32]).unwrap(),
4176                         SecretKey::from_slice(&[41; 32]).unwrap(),
4177                         SecretKey::from_slice(&[41; 32]).unwrap(),
4178                         SecretKey::from_slice(&[41; 32]).unwrap(),
4179                         SecretKey::from_slice(&[41; 32]).unwrap(),
4180                         [41; 32],
4181                         0,
4182                         [0; 32],
4183                 );
4184
4185                 let counterparty_pubkeys = ChannelPublicKeys {
4186                         funding_pubkey: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
4187                         revocation_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
4188                         payment_point: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[46; 32]).unwrap()),
4189                         delayed_payment_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[47; 32]).unwrap()),
4190                         htlc_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[48; 32]).unwrap())
4191                 };
4192                 let funding_outpoint = OutPoint { txid: Txid::all_zeros(), index: u16::max_value() };
4193                 let channel_parameters = ChannelTransactionParameters {
4194                         holder_pubkeys: keys.holder_channel_pubkeys.clone(),
4195                         holder_selected_contest_delay: 66,
4196                         is_outbound_from_holder: true,
4197                         counterparty_parameters: Some(CounterpartyChannelTransactionParameters {
4198                                 pubkeys: counterparty_pubkeys,
4199                                 selected_contest_delay: 67,
4200                         }),
4201                         funding_outpoint: Some(funding_outpoint),
4202                         opt_anchors: None,
4203                         opt_non_zero_fee_anchors: None,
4204                 };
4205                 // Prune with one old state and a holder commitment tx holding a few overlaps with the
4206                 // old state.
4207                 let shutdown_pubkey = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
4208                 let best_block = BestBlock::from_network(Network::Testnet);
4209                 let monitor = ChannelMonitor::new(Secp256k1::new(), keys,
4210                                                   Some(ShutdownScript::new_p2wpkh_from_pubkey(shutdown_pubkey).into_inner()), 0, &Script::new(),
4211                                                   (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
4212                                                   &channel_parameters,
4213                                                   Script::new(), 46, 0,
4214                                                   HolderCommitmentTransaction::dummy(), best_block, dummy_key);
4215
4216                 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..10])).unwrap();
4217                 monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"1").into_inner()),
4218                         preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
4219                 monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"2").into_inner()),
4220                         preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
4221                 for &(ref preimage, ref hash) in preimages.iter() {
4222                         let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&fee_estimator);
4223                         monitor.provide_payment_preimage(hash, preimage, &broadcaster, &bounded_fee_estimator, &logger);
4224                 }
4225
4226                 // Now provide a secret, pruning preimages 10-15
4227                 let mut secret = [0; 32];
4228                 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
4229                 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
4230                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 15);
4231                 test_preimages_exist!(&preimages[0..10], monitor);
4232                 test_preimages_exist!(&preimages[15..20], monitor);
4233
4234                 monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"3").into_inner()),
4235                         preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
4236
4237                 // Now provide a further secret, pruning preimages 15-17
4238                 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
4239                 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
4240                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 13);
4241                 test_preimages_exist!(&preimages[0..10], monitor);
4242                 test_preimages_exist!(&preimages[17..20], monitor);
4243
4244                 monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"4").into_inner()),
4245                         preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
4246
4247                 // Now update holder commitment tx info, pruning only element 18 as we still care about the
4248                 // previous commitment tx's preimages too
4249                 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..5])).unwrap();
4250                 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
4251                 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
4252                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 12);
4253                 test_preimages_exist!(&preimages[0..10], monitor);
4254                 test_preimages_exist!(&preimages[18..20], monitor);
4255
4256                 // But if we do it again, we'll prune 5-10
4257                 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..3])).unwrap();
4258                 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
4259                 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
4260                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 5);
4261                 test_preimages_exist!(&preimages[0..5], monitor);
4262         }
4263
4264         #[test]
4265         fn test_claim_txn_weight_computation() {
4266                 // We test Claim txn weight, knowing that we want expected weigth and
4267                 // not actual case to avoid sigs and time-lock delays hell variances.
4268
4269                 let secp_ctx = Secp256k1::new();
4270                 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
4271                 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
4272
4273                 macro_rules! sign_input {
4274                         ($sighash_parts: expr, $idx: expr, $amount: expr, $weight: expr, $sum_actual_sigs: expr, $opt_anchors: expr) => {
4275                                 let htlc = HTLCOutputInCommitment {
4276                                         offered: if *$weight == weight_revoked_offered_htlc($opt_anchors) || *$weight == weight_offered_htlc($opt_anchors) { true } else { false },
4277                                         amount_msat: 0,
4278                                         cltv_expiry: 2 << 16,
4279                                         payment_hash: PaymentHash([1; 32]),
4280                                         transaction_output_index: Some($idx as u32),
4281                                 };
4282                                 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, $opt_anchors, &pubkey, &pubkey, &pubkey) };
4283                                 let sighash = hash_to_message!(&$sighash_parts.segwit_signature_hash($idx, &redeem_script, $amount, EcdsaSighashType::All).unwrap()[..]);
4284                                 let sig = secp_ctx.sign_ecdsa(&sighash, &privkey);
4285                                 let mut ser_sig = sig.serialize_der().to_vec();
4286                                 ser_sig.push(EcdsaSighashType::All as u8);
4287                                 $sum_actual_sigs += ser_sig.len();
4288                                 let witness = $sighash_parts.witness_mut($idx).unwrap();
4289                                 witness.push(ser_sig);
4290                                 if *$weight == WEIGHT_REVOKED_OUTPUT {
4291                                         witness.push(vec!(1));
4292                                 } else if *$weight == weight_revoked_offered_htlc($opt_anchors) || *$weight == weight_revoked_received_htlc($opt_anchors) {
4293                                         witness.push(pubkey.clone().serialize().to_vec());
4294                                 } else if *$weight == weight_received_htlc($opt_anchors) {
4295                                         witness.push(vec![0]);
4296                                 } else {
4297                                         witness.push(PaymentPreimage([1; 32]).0.to_vec());
4298                                 }
4299                                 witness.push(redeem_script.into_bytes());
4300                                 let witness = witness.to_vec();
4301                                 println!("witness[0] {}", witness[0].len());
4302                                 println!("witness[1] {}", witness[1].len());
4303                                 println!("witness[2] {}", witness[2].len());
4304                         }
4305                 }
4306
4307                 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
4308                 let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
4309
4310                 // Justice tx with 1 to_holder, 2 revoked offered HTLCs, 1 revoked received HTLCs
4311                 for &opt_anchors in [false, true].iter() {
4312                         let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
4313                         let mut sum_actual_sigs = 0;
4314                         for i in 0..4 {
4315                                 claim_tx.input.push(TxIn {
4316                                         previous_output: BitcoinOutPoint {
4317                                                 txid,
4318                                                 vout: i,
4319                                         },
4320                                         script_sig: Script::new(),
4321                                         sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
4322                                         witness: Witness::new(),
4323                                 });
4324                         }
4325                         claim_tx.output.push(TxOut {
4326                                 script_pubkey: script_pubkey.clone(),
4327                                 value: 0,
4328                         });
4329                         let base_weight = claim_tx.weight();
4330                         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)];
4331                         let mut inputs_total_weight = 2; // count segwit flags
4332                         {
4333                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
4334                                 for (idx, inp) in inputs_weight.iter().enumerate() {
4335                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
4336                                         inputs_total_weight += inp;
4337                                 }
4338                         }
4339                         assert_eq!(base_weight + inputs_total_weight as usize,  claim_tx.weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
4340                 }
4341
4342                 // Claim tx with 1 offered HTLCs, 3 received HTLCs
4343                 for &opt_anchors in [false, true].iter() {
4344                         let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
4345                         let mut sum_actual_sigs = 0;
4346                         for i in 0..4 {
4347                                 claim_tx.input.push(TxIn {
4348                                         previous_output: BitcoinOutPoint {
4349                                                 txid,
4350                                                 vout: i,
4351                                         },
4352                                         script_sig: Script::new(),
4353                                         sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
4354                                         witness: Witness::new(),
4355                                 });
4356                         }
4357                         claim_tx.output.push(TxOut {
4358                                 script_pubkey: script_pubkey.clone(),
4359                                 value: 0,
4360                         });
4361                         let base_weight = claim_tx.weight();
4362                         let inputs_weight = vec![weight_offered_htlc(opt_anchors), weight_received_htlc(opt_anchors), weight_received_htlc(opt_anchors), weight_received_htlc(opt_anchors)];
4363                         let mut inputs_total_weight = 2; // count segwit flags
4364                         {
4365                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
4366                                 for (idx, inp) in inputs_weight.iter().enumerate() {
4367                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
4368                                         inputs_total_weight += inp;
4369                                 }
4370                         }
4371                         assert_eq!(base_weight + inputs_total_weight as usize,  claim_tx.weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
4372                 }
4373
4374                 // Justice tx with 1 revoked HTLC-Success tx output
4375                 for &opt_anchors in [false, true].iter() {
4376                         let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
4377                         let mut sum_actual_sigs = 0;
4378                         claim_tx.input.push(TxIn {
4379                                 previous_output: BitcoinOutPoint {
4380                                         txid,
4381                                         vout: 0,
4382                                 },
4383                                 script_sig: Script::new(),
4384                                 sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
4385                                 witness: Witness::new(),
4386                         });
4387                         claim_tx.output.push(TxOut {
4388                                 script_pubkey: script_pubkey.clone(),
4389                                 value: 0,
4390                         });
4391                         let base_weight = claim_tx.weight();
4392                         let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT];
4393                         let mut inputs_total_weight = 2; // count segwit flags
4394                         {
4395                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
4396                                 for (idx, inp) in inputs_weight.iter().enumerate() {
4397                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
4398                                         inputs_total_weight += inp;
4399                                 }
4400                         }
4401                         assert_eq!(base_weight + inputs_total_weight as usize, claim_tx.weight() + /* max_length_isg */ (73 * inputs_weight.len() - sum_actual_sigs));
4402                 }
4403         }
4404
4405         // Further testing is done in the ChannelManager integration tests.
4406 }