]> git.bitcoin.ninja Git - rust-lightning/blob - lightning/src/chain/channelmonitor.rs
Merge pull request #2064 from TheBlueMatt/2023-03-debug-futures
[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 latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date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;
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         },
498         LatestCounterpartyCommitmentTXInfo {
499                 commitment_txid: Txid,
500                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
501                 commitment_number: u64,
502                 their_per_commitment_point: PublicKey,
503         },
504         PaymentPreimage {
505                 payment_preimage: PaymentPreimage,
506         },
507         CommitmentSecret {
508                 idx: u64,
509                 secret: [u8; 32],
510         },
511         /// Used to indicate that the no future updates will occur, and likely that the latest holder
512         /// commitment transaction(s) should be broadcast, as the channel has been force-closed.
513         ChannelForceClosed {
514                 /// If set to false, we shouldn't broadcast the latest holder commitment transaction as we
515                 /// think we've fallen behind!
516                 should_broadcast: bool,
517         },
518         ShutdownScript {
519                 scriptpubkey: Script,
520         },
521 }
522
523 impl ChannelMonitorUpdateStep {
524         fn variant_name(&self) -> &'static str {
525                 match self {
526                         ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { .. } => "LatestHolderCommitmentTXInfo",
527                         ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { .. } => "LatestCounterpartyCommitmentTXInfo",
528                         ChannelMonitorUpdateStep::PaymentPreimage { .. } => "PaymentPreimage",
529                         ChannelMonitorUpdateStep::CommitmentSecret { .. } => "CommitmentSecret",
530                         ChannelMonitorUpdateStep::ChannelForceClosed { .. } => "ChannelForceClosed",
531                         ChannelMonitorUpdateStep::ShutdownScript { .. } => "ShutdownScript",
532                 }
533         }
534 }
535
536 impl_writeable_tlv_based_enum_upgradable!(ChannelMonitorUpdateStep,
537         (0, LatestHolderCommitmentTXInfo) => {
538                 (0, commitment_tx, required),
539                 (2, htlc_outputs, vec_type),
540         },
541         (1, LatestCounterpartyCommitmentTXInfo) => {
542                 (0, commitment_txid, required),
543                 (2, commitment_number, required),
544                 (4, their_per_commitment_point, required),
545                 (6, htlc_outputs, vec_type),
546         },
547         (2, PaymentPreimage) => {
548                 (0, payment_preimage, required),
549         },
550         (3, CommitmentSecret) => {
551                 (0, idx, required),
552                 (2, secret, required),
553         },
554         (4, ChannelForceClosed) => {
555                 (0, should_broadcast, required),
556         },
557         (5, ShutdownScript) => {
558                 (0, scriptpubkey, required),
559         },
560 );
561
562 /// Details about the balance(s) available for spending once the channel appears on chain.
563 ///
564 /// See [`ChannelMonitor::get_claimable_balances`] for more details on when these will or will not
565 /// be provided.
566 #[derive(Clone, Debug, PartialEq, Eq)]
567 #[cfg_attr(test, derive(PartialOrd, Ord))]
568 pub enum Balance {
569         /// The channel is not yet closed (or the commitment or closing transaction has not yet
570         /// appeared in a block). The given balance is claimable (less on-chain fees) if the channel is
571         /// force-closed now.
572         ClaimableOnChannelClose {
573                 /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
574                 /// required to do so.
575                 claimable_amount_satoshis: u64,
576         },
577         /// The channel has been closed, and the given balance is ours but awaiting confirmations until
578         /// we consider it spendable.
579         ClaimableAwaitingConfirmations {
580                 /// The amount available to claim, in satoshis, possibly excluding the on-chain fees which
581                 /// were spent in broadcasting the transaction.
582                 claimable_amount_satoshis: u64,
583                 /// The height at which an [`Event::SpendableOutputs`] event will be generated for this
584                 /// amount.
585                 confirmation_height: u32,
586         },
587         /// The channel has been closed, and the given balance should be ours but awaiting spending
588         /// transaction confirmation. If the spending transaction does not confirm in time, it is
589         /// possible our counterparty can take the funds by broadcasting an HTLC timeout on-chain.
590         ///
591         /// Once the spending transaction confirms, before it has reached enough confirmations to be
592         /// considered safe from chain reorganizations, the balance will instead be provided via
593         /// [`Balance::ClaimableAwaitingConfirmations`].
594         ContentiousClaimable {
595                 /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
596                 /// required to do so.
597                 claimable_amount_satoshis: u64,
598                 /// The height at which the counterparty may be able to claim the balance if we have not
599                 /// done so.
600                 timeout_height: u32,
601         },
602         /// HTLCs which we sent to our counterparty which are claimable after a timeout (less on-chain
603         /// fees) if the counterparty does not know the preimage for the HTLCs. These are somewhat
604         /// likely to be claimed by our counterparty before we do.
605         MaybeTimeoutClaimableHTLC {
606                 /// The amount potentially available to claim, in satoshis, excluding the on-chain fees
607                 /// which will be required to do so.
608                 claimable_amount_satoshis: u64,
609                 /// The height at which we will be able to claim the balance if our counterparty has not
610                 /// done so.
611                 claimable_height: u32,
612         },
613         /// HTLCs which we received from our counterparty which are claimable with a preimage which we
614         /// do not currently have. This will only be claimable if we receive the preimage from the node
615         /// to which we forwarded this HTLC before the timeout.
616         MaybePreimageClaimableHTLC {
617                 /// The amount potentially available to claim, in satoshis, excluding the on-chain fees
618                 /// which will be required to do so.
619                 claimable_amount_satoshis: u64,
620                 /// The height at which our counterparty will be able to claim the balance if we have not
621                 /// yet received the preimage and claimed it ourselves.
622                 expiry_height: u32,
623         },
624         /// The channel has been closed, and our counterparty broadcasted a revoked commitment
625         /// transaction.
626         ///
627         /// Thus, we're able to claim all outputs in the commitment transaction, one of which has the
628         /// following amount.
629         CounterpartyRevokedOutputClaimable {
630                 /// The amount, in satoshis, of the output which we can claim.
631                 ///
632                 /// Note that for outputs from HTLC balances this may be excluding some on-chain fees that
633                 /// were already spent.
634                 claimable_amount_satoshis: u64,
635         },
636 }
637
638 /// An HTLC which has been irrevocably resolved on-chain, and has reached ANTI_REORG_DELAY.
639 #[derive(PartialEq, Eq)]
640 struct IrrevocablyResolvedHTLC {
641         commitment_tx_output_idx: Option<u32>,
642         /// The txid of the transaction which resolved the HTLC, this may be a commitment (if the HTLC
643         /// was not present in the confirmed commitment transaction), HTLC-Success, or HTLC-Timeout
644         /// transaction.
645         resolving_txid: Option<Txid>, // Added as optional, but always filled in, in 0.0.110
646         resolving_tx: Option<Transaction>,
647         /// Only set if the HTLC claim was ours using a payment preimage
648         payment_preimage: Option<PaymentPreimage>,
649 }
650
651 // In LDK versions prior to 0.0.111 commitment_tx_output_idx was not Option-al and
652 // IrrevocablyResolvedHTLC objects only existed for non-dust HTLCs. This was a bug, but to maintain
653 // backwards compatibility we must ensure we always write out a commitment_tx_output_idx field,
654 // using `u32::max_value()` as a sentinal to indicate the HTLC was dust.
655 impl Writeable for IrrevocablyResolvedHTLC {
656         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
657                 let mapped_commitment_tx_output_idx = self.commitment_tx_output_idx.unwrap_or(u32::max_value());
658                 write_tlv_fields!(writer, {
659                         (0, mapped_commitment_tx_output_idx, required),
660                         (1, self.resolving_txid, option),
661                         (2, self.payment_preimage, option),
662                         (3, self.resolving_tx, option),
663                 });
664                 Ok(())
665         }
666 }
667
668 impl Readable for IrrevocablyResolvedHTLC {
669         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
670                 let mut mapped_commitment_tx_output_idx = 0;
671                 let mut resolving_txid = None;
672                 let mut payment_preimage = None;
673                 let mut resolving_tx = None;
674                 read_tlv_fields!(reader, {
675                         (0, mapped_commitment_tx_output_idx, required),
676                         (1, resolving_txid, option),
677                         (2, payment_preimage, option),
678                         (3, resolving_tx, option),
679                 });
680                 Ok(Self {
681                         commitment_tx_output_idx: if mapped_commitment_tx_output_idx == u32::max_value() { None } else { Some(mapped_commitment_tx_output_idx) },
682                         resolving_txid,
683                         payment_preimage,
684                         resolving_tx,
685                 })
686         }
687 }
688
689 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
690 /// on-chain transactions to ensure no loss of funds occurs.
691 ///
692 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
693 /// information and are actively monitoring the chain.
694 ///
695 /// Pending Events or updated HTLCs which have not yet been read out by
696 /// get_and_clear_pending_monitor_events or get_and_clear_pending_events are serialized to disk and
697 /// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
698 /// gotten are fully handled before re-serializing the new state.
699 ///
700 /// Note that the deserializer is only implemented for (BlockHash, ChannelMonitor), which
701 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
702 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
703 /// returned block hash and the the current chain and then reconnecting blocks to get to the
704 /// best chain) upon deserializing the object!
705 pub struct ChannelMonitor<Signer: WriteableEcdsaChannelSigner> {
706         #[cfg(test)]
707         pub(crate) inner: Mutex<ChannelMonitorImpl<Signer>>,
708         #[cfg(not(test))]
709         inner: Mutex<ChannelMonitorImpl<Signer>>,
710 }
711
712 #[derive(PartialEq)]
713 pub(crate) struct ChannelMonitorImpl<Signer: WriteableEcdsaChannelSigner> {
714         latest_update_id: u64,
715         commitment_transaction_number_obscure_factor: u64,
716
717         destination_script: Script,
718         broadcasted_holder_revokable_script: Option<(Script, PublicKey, PublicKey)>,
719         counterparty_payment_script: Script,
720         shutdown_script: Option<Script>,
721
722         channel_keys_id: [u8; 32],
723         holder_revocation_basepoint: PublicKey,
724         funding_info: (OutPoint, Script),
725         current_counterparty_commitment_txid: Option<Txid>,
726         prev_counterparty_commitment_txid: Option<Txid>,
727
728         counterparty_commitment_params: CounterpartyCommitmentParameters,
729         funding_redeemscript: Script,
730         channel_value_satoshis: u64,
731         // first is the idx of the first of the two per-commitment points
732         their_cur_per_commitment_points: Option<(u64, PublicKey, Option<PublicKey>)>,
733
734         on_holder_tx_csv: u16,
735
736         commitment_secrets: CounterpartyCommitmentSecrets,
737         /// The set of outpoints in each counterparty commitment transaction. We always need at least
738         /// the payment hash from `HTLCOutputInCommitment` to claim even a revoked commitment
739         /// transaction broadcast as we need to be able to construct the witness script in all cases.
740         counterparty_claimable_outpoints: HashMap<Txid, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
741         /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
742         /// Nor can we figure out their commitment numbers without the commitment transaction they are
743         /// spending. Thus, in order to claim them via revocation key, we track all the counterparty
744         /// commitment transactions which we find on-chain, mapping them to the commitment number which
745         /// can be used to derive the revocation key and claim the transactions.
746         counterparty_commitment_txn_on_chain: HashMap<Txid, u64>,
747         /// Cache used to make pruning of payment_preimages faster.
748         /// Maps payment_hash values to commitment numbers for counterparty transactions for non-revoked
749         /// counterparty transactions (ie should remain pretty small).
750         /// Serialized to disk but should generally not be sent to Watchtowers.
751         counterparty_hash_commitment_number: HashMap<PaymentHash, u64>,
752
753         // We store two holder commitment transactions to avoid any race conditions where we may update
754         // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
755         // various monitors for one channel being out of sync, and us broadcasting a holder
756         // transaction for which we have deleted claim information on some watchtowers.
757         prev_holder_signed_commitment_tx: Option<HolderSignedTx>,
758         current_holder_commitment_tx: HolderSignedTx,
759
760         // Used just for ChannelManager to make sure it has the latest channel data during
761         // deserialization
762         current_counterparty_commitment_number: u64,
763         // Used just for ChannelManager to make sure it has the latest channel data during
764         // deserialization
765         current_holder_commitment_number: u64,
766
767         /// The set of payment hashes from inbound payments for which we know the preimage. Payment
768         /// preimages that are not included in any unrevoked local commitment transaction or unrevoked
769         /// remote commitment transactions are automatically removed when commitment transactions are
770         /// revoked.
771         payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
772
773         // Note that `MonitorEvent`s MUST NOT be generated during update processing, only generated
774         // during chain data processing. This prevents a race in `ChainMonitor::update_channel` (and
775         // presumably user implementations thereof as well) where we update the in-memory channel
776         // object, then before the persistence finishes (as it's all under a read-lock), we return
777         // pending events to the user or to the relevant `ChannelManager`. Then, on reload, we'll have
778         // the pre-event state here, but have processed the event in the `ChannelManager`.
779         // Note that because the `event_lock` in `ChainMonitor` is only taken in
780         // block/transaction-connected events and *not* during block/transaction-disconnected events,
781         // we further MUST NOT generate events during block/transaction-disconnection.
782         pending_monitor_events: Vec<MonitorEvent>,
783
784         pending_events: Vec<Event>,
785
786         // Used to track on-chain events (i.e., transactions part of channels confirmed on chain) on
787         // which to take actions once they reach enough confirmations. Each entry includes the
788         // transaction's id and the height when the transaction was confirmed on chain.
789         onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
790
791         // If we get serialized out and re-read, we need to make sure that the chain monitoring
792         // interface knows about the TXOs that we want to be notified of spends of. We could probably
793         // be smart and derive them from the above storage fields, but its much simpler and more
794         // Obviously Correct (tm) if we just keep track of them explicitly.
795         outputs_to_watch: HashMap<Txid, Vec<(u32, Script)>>,
796
797         #[cfg(test)]
798         pub onchain_tx_handler: OnchainTxHandler<Signer>,
799         #[cfg(not(test))]
800         onchain_tx_handler: OnchainTxHandler<Signer>,
801
802         // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
803         // channel has been force-closed. After this is set, no further holder commitment transaction
804         // updates may occur, and we panic!() if one is provided.
805         lockdown_from_offchain: bool,
806
807         // Set once we've signed a holder commitment transaction and handed it over to our
808         // OnchainTxHandler. After this is set, no future updates to our holder commitment transactions
809         // may occur, and we fail any such monitor updates.
810         //
811         // In case of update rejection due to a locally already signed commitment transaction, we
812         // nevertheless store update content to track in case of concurrent broadcast by another
813         // remote monitor out-of-order with regards to the block view.
814         holder_tx_signed: bool,
815
816         // If a spend of the funding output is seen, we set this to true and reject any further
817         // updates. This prevents any further changes in the offchain state no matter the order
818         // of block connection between ChannelMonitors and the ChannelManager.
819         funding_spend_seen: bool,
820
821         /// Set to `Some` of the confirmed transaction spending the funding input of the channel after
822         /// reaching `ANTI_REORG_DELAY` confirmations.
823         funding_spend_confirmed: Option<Txid>,
824
825         confirmed_commitment_tx_counterparty_output: CommitmentTxCounterpartyOutputInfo,
826         /// The set of HTLCs which have been either claimed or failed on chain and have reached
827         /// the requisite confirmations on the claim/fail transaction (either ANTI_REORG_DELAY or the
828         /// spending CSV for revocable outputs).
829         htlcs_resolved_on_chain: Vec<IrrevocablyResolvedHTLC>,
830
831         /// The set of `SpendableOutput` events which we have already passed upstream to be claimed.
832         /// These are tracked explicitly to ensure that we don't generate the same events redundantly
833         /// if users duplicatively confirm old transactions. Specifically for transactions claiming a
834         /// revoked remote outpoint we otherwise have no tracking at all once they've reached
835         /// [`ANTI_REORG_DELAY`], so we have to track them here.
836         spendable_txids_confirmed: Vec<Txid>,
837
838         // We simply modify best_block in Channel's block_connected so that serialization is
839         // consistent but hopefully the users' copy handles block_connected in a consistent way.
840         // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
841         // their best_block from its state and not based on updated copies that didn't run through
842         // the full block_connected).
843         best_block: BestBlock,
844
845         /// The node_id of our counterparty
846         counterparty_node_id: Option<PublicKey>,
847 }
848
849 /// Transaction outputs to watch for on-chain spends.
850 pub type TransactionOutputs = (Txid, Vec<(u32, TxOut)>);
851
852 impl<Signer: WriteableEcdsaChannelSigner> PartialEq for ChannelMonitor<Signer> where Signer: PartialEq {
853         fn eq(&self, other: &Self) -> bool {
854                 // We need some kind of total lockorder. Absent a better idea, we sort by position in
855                 // memory and take locks in that order (assuming that we can't move within memory while a
856                 // lock is held).
857                 let ord = ((self as *const _) as usize) < ((other as *const _) as usize);
858                 let a = if ord { self.inner.unsafe_well_ordered_double_lock_self() } else { other.inner.unsafe_well_ordered_double_lock_self() };
859                 let b = if ord { other.inner.unsafe_well_ordered_double_lock_self() } else { self.inner.unsafe_well_ordered_double_lock_self() };
860                 a.eq(&b)
861         }
862 }
863
864 impl<Signer: WriteableEcdsaChannelSigner> Writeable for ChannelMonitor<Signer> {
865         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
866                 self.inner.lock().unwrap().write(writer)
867         }
868 }
869
870 // These are also used for ChannelMonitorUpdate, above.
871 const SERIALIZATION_VERSION: u8 = 1;
872 const MIN_SERIALIZATION_VERSION: u8 = 1;
873
874 impl<Signer: WriteableEcdsaChannelSigner> Writeable for ChannelMonitorImpl<Signer> {
875         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
876                 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
877
878                 self.latest_update_id.write(writer)?;
879
880                 // Set in initial Channel-object creation, so should always be set by now:
881                 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
882
883                 self.destination_script.write(writer)?;
884                 if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
885                         writer.write_all(&[0; 1])?;
886                         broadcasted_holder_revokable_script.0.write(writer)?;
887                         broadcasted_holder_revokable_script.1.write(writer)?;
888                         broadcasted_holder_revokable_script.2.write(writer)?;
889                 } else {
890                         writer.write_all(&[1; 1])?;
891                 }
892
893                 self.counterparty_payment_script.write(writer)?;
894                 match &self.shutdown_script {
895                         Some(script) => script.write(writer)?,
896                         None => Script::new().write(writer)?,
897                 }
898
899                 self.channel_keys_id.write(writer)?;
900                 self.holder_revocation_basepoint.write(writer)?;
901                 writer.write_all(&self.funding_info.0.txid[..])?;
902                 writer.write_all(&self.funding_info.0.index.to_be_bytes())?;
903                 self.funding_info.1.write(writer)?;
904                 self.current_counterparty_commitment_txid.write(writer)?;
905                 self.prev_counterparty_commitment_txid.write(writer)?;
906
907                 self.counterparty_commitment_params.write(writer)?;
908                 self.funding_redeemscript.write(writer)?;
909                 self.channel_value_satoshis.write(writer)?;
910
911                 match self.their_cur_per_commitment_points {
912                         Some((idx, pubkey, second_option)) => {
913                                 writer.write_all(&byte_utils::be48_to_array(idx))?;
914                                 writer.write_all(&pubkey.serialize())?;
915                                 match second_option {
916                                         Some(second_pubkey) => {
917                                                 writer.write_all(&second_pubkey.serialize())?;
918                                         },
919                                         None => {
920                                                 writer.write_all(&[0; 33])?;
921                                         },
922                                 }
923                         },
924                         None => {
925                                 writer.write_all(&byte_utils::be48_to_array(0))?;
926                         },
927                 }
928
929                 writer.write_all(&self.on_holder_tx_csv.to_be_bytes())?;
930
931                 self.commitment_secrets.write(writer)?;
932
933                 macro_rules! serialize_htlc_in_commitment {
934                         ($htlc_output: expr) => {
935                                 writer.write_all(&[$htlc_output.offered as u8; 1])?;
936                                 writer.write_all(&$htlc_output.amount_msat.to_be_bytes())?;
937                                 writer.write_all(&$htlc_output.cltv_expiry.to_be_bytes())?;
938                                 writer.write_all(&$htlc_output.payment_hash.0[..])?;
939                                 $htlc_output.transaction_output_index.write(writer)?;
940                         }
941                 }
942
943                 writer.write_all(&(self.counterparty_claimable_outpoints.len() as u64).to_be_bytes())?;
944                 for (ref txid, ref htlc_infos) in self.counterparty_claimable_outpoints.iter() {
945                         writer.write_all(&txid[..])?;
946                         writer.write_all(&(htlc_infos.len() as u64).to_be_bytes())?;
947                         for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
948                                 debug_assert!(htlc_source.is_none() || Some(**txid) == self.current_counterparty_commitment_txid
949                                                 || Some(**txid) == self.prev_counterparty_commitment_txid,
950                                         "HTLC Sources for all revoked commitment transactions should be none!");
951                                 serialize_htlc_in_commitment!(htlc_output);
952                                 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
953                         }
954                 }
955
956                 writer.write_all(&(self.counterparty_commitment_txn_on_chain.len() as u64).to_be_bytes())?;
957                 for (ref txid, commitment_number) in self.counterparty_commitment_txn_on_chain.iter() {
958                         writer.write_all(&txid[..])?;
959                         writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
960                 }
961
962                 writer.write_all(&(self.counterparty_hash_commitment_number.len() as u64).to_be_bytes())?;
963                 for (ref payment_hash, commitment_number) in self.counterparty_hash_commitment_number.iter() {
964                         writer.write_all(&payment_hash.0[..])?;
965                         writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
966                 }
967
968                 if let Some(ref prev_holder_tx) = self.prev_holder_signed_commitment_tx {
969                         writer.write_all(&[1; 1])?;
970                         prev_holder_tx.write(writer)?;
971                 } else {
972                         writer.write_all(&[0; 1])?;
973                 }
974
975                 self.current_holder_commitment_tx.write(writer)?;
976
977                 writer.write_all(&byte_utils::be48_to_array(self.current_counterparty_commitment_number))?;
978                 writer.write_all(&byte_utils::be48_to_array(self.current_holder_commitment_number))?;
979
980                 writer.write_all(&(self.payment_preimages.len() as u64).to_be_bytes())?;
981                 for payment_preimage in self.payment_preimages.values() {
982                         writer.write_all(&payment_preimage.0[..])?;
983                 }
984
985                 writer.write_all(&(self.pending_monitor_events.iter().filter(|ev| match ev {
986                         MonitorEvent::HTLCEvent(_) => true,
987                         MonitorEvent::CommitmentTxConfirmed(_) => true,
988                         _ => false,
989                 }).count() as u64).to_be_bytes())?;
990                 for event in self.pending_monitor_events.iter() {
991                         match event {
992                                 MonitorEvent::HTLCEvent(upd) => {
993                                         0u8.write(writer)?;
994                                         upd.write(writer)?;
995                                 },
996                                 MonitorEvent::CommitmentTxConfirmed(_) => 1u8.write(writer)?,
997                                 _ => {}, // Covered in the TLV writes below
998                         }
999                 }
1000
1001                 writer.write_all(&(self.pending_events.len() as u64).to_be_bytes())?;
1002                 for event in self.pending_events.iter() {
1003                         event.write(writer)?;
1004                 }
1005
1006                 self.best_block.block_hash().write(writer)?;
1007                 writer.write_all(&self.best_block.height().to_be_bytes())?;
1008
1009                 writer.write_all(&(self.onchain_events_awaiting_threshold_conf.len() as u64).to_be_bytes())?;
1010                 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
1011                         entry.write(writer)?;
1012                 }
1013
1014                 (self.outputs_to_watch.len() as u64).write(writer)?;
1015                 for (txid, idx_scripts) in self.outputs_to_watch.iter() {
1016                         txid.write(writer)?;
1017                         (idx_scripts.len() as u64).write(writer)?;
1018                         for (idx, script) in idx_scripts.iter() {
1019                                 idx.write(writer)?;
1020                                 script.write(writer)?;
1021                         }
1022                 }
1023                 self.onchain_tx_handler.write(writer)?;
1024
1025                 self.lockdown_from_offchain.write(writer)?;
1026                 self.holder_tx_signed.write(writer)?;
1027
1028                 write_tlv_fields!(writer, {
1029                         (1, self.funding_spend_confirmed, option),
1030                         (3, self.htlcs_resolved_on_chain, vec_type),
1031                         (5, self.pending_monitor_events, vec_type),
1032                         (7, self.funding_spend_seen, required),
1033                         (9, self.counterparty_node_id, option),
1034                         (11, self.confirmed_commitment_tx_counterparty_output, option),
1035                         (13, self.spendable_txids_confirmed, vec_type),
1036                 });
1037
1038                 Ok(())
1039         }
1040 }
1041
1042 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
1043         /// For lockorder enforcement purposes, we need to have a single site which constructs the
1044         /// `inner` mutex, otherwise cases where we lock two monitors at the same time (eg in our
1045         /// PartialEq implementation) we may decide a lockorder violation has occurred.
1046         fn from_impl(imp: ChannelMonitorImpl<Signer>) -> Self {
1047                 ChannelMonitor { inner: Mutex::new(imp) }
1048         }
1049
1050         pub(crate) fn new(secp_ctx: Secp256k1<secp256k1::All>, keys: Signer, shutdown_script: Option<Script>,
1051                           on_counterparty_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
1052                           channel_parameters: &ChannelTransactionParameters,
1053                           funding_redeemscript: Script, channel_value_satoshis: u64,
1054                           commitment_transaction_number_obscure_factor: u64,
1055                           initial_holder_commitment_tx: HolderCommitmentTransaction,
1056                           best_block: BestBlock, counterparty_node_id: PublicKey) -> ChannelMonitor<Signer> {
1057
1058                 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
1059                 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
1060                 let counterparty_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
1061
1062                 let counterparty_channel_parameters = channel_parameters.counterparty_parameters.as_ref().unwrap();
1063                 let counterparty_delayed_payment_base_key = counterparty_channel_parameters.pubkeys.delayed_payment_basepoint;
1064                 let counterparty_htlc_base_key = counterparty_channel_parameters.pubkeys.htlc_basepoint;
1065                 let counterparty_commitment_params = CounterpartyCommitmentParameters { counterparty_delayed_payment_base_key, counterparty_htlc_base_key, on_counterparty_tx_csv };
1066
1067                 let channel_keys_id = keys.channel_keys_id();
1068                 let holder_revocation_basepoint = keys.pubkeys().revocation_basepoint;
1069
1070                 // block for Rust 1.34 compat
1071                 let (holder_commitment_tx, current_holder_commitment_number) = {
1072                         let trusted_tx = initial_holder_commitment_tx.trust();
1073                         let txid = trusted_tx.txid();
1074
1075                         let tx_keys = trusted_tx.keys();
1076                         let holder_commitment_tx = HolderSignedTx {
1077                                 txid,
1078                                 revocation_key: tx_keys.revocation_key,
1079                                 a_htlc_key: tx_keys.broadcaster_htlc_key,
1080                                 b_htlc_key: tx_keys.countersignatory_htlc_key,
1081                                 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
1082                                 per_commitment_point: tx_keys.per_commitment_point,
1083                                 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
1084                                 to_self_value_sat: initial_holder_commitment_tx.to_broadcaster_value_sat(),
1085                                 feerate_per_kw: trusted_tx.feerate_per_kw(),
1086                         };
1087                         (holder_commitment_tx, trusted_tx.commitment_number())
1088                 };
1089
1090                 let onchain_tx_handler =
1091                         OnchainTxHandler::new(destination_script.clone(), keys,
1092                         channel_parameters.clone(), initial_holder_commitment_tx, secp_ctx);
1093
1094                 let mut outputs_to_watch = HashMap::new();
1095                 outputs_to_watch.insert(funding_info.0.txid, vec![(funding_info.0.index as u32, funding_info.1.clone())]);
1096
1097                 Self::from_impl(ChannelMonitorImpl {
1098                         latest_update_id: 0,
1099                         commitment_transaction_number_obscure_factor,
1100
1101                         destination_script: destination_script.clone(),
1102                         broadcasted_holder_revokable_script: None,
1103                         counterparty_payment_script,
1104                         shutdown_script,
1105
1106                         channel_keys_id,
1107                         holder_revocation_basepoint,
1108                         funding_info,
1109                         current_counterparty_commitment_txid: None,
1110                         prev_counterparty_commitment_txid: None,
1111
1112                         counterparty_commitment_params,
1113                         funding_redeemscript,
1114                         channel_value_satoshis,
1115                         their_cur_per_commitment_points: None,
1116
1117                         on_holder_tx_csv: counterparty_channel_parameters.selected_contest_delay,
1118
1119                         commitment_secrets: CounterpartyCommitmentSecrets::new(),
1120                         counterparty_claimable_outpoints: HashMap::new(),
1121                         counterparty_commitment_txn_on_chain: HashMap::new(),
1122                         counterparty_hash_commitment_number: HashMap::new(),
1123
1124                         prev_holder_signed_commitment_tx: None,
1125                         current_holder_commitment_tx: holder_commitment_tx,
1126                         current_counterparty_commitment_number: 1 << 48,
1127                         current_holder_commitment_number,
1128
1129                         payment_preimages: HashMap::new(),
1130                         pending_monitor_events: Vec::new(),
1131                         pending_events: Vec::new(),
1132
1133                         onchain_events_awaiting_threshold_conf: Vec::new(),
1134                         outputs_to_watch,
1135
1136                         onchain_tx_handler,
1137
1138                         lockdown_from_offchain: false,
1139                         holder_tx_signed: false,
1140                         funding_spend_seen: false,
1141                         funding_spend_confirmed: None,
1142                         confirmed_commitment_tx_counterparty_output: None,
1143                         htlcs_resolved_on_chain: Vec::new(),
1144                         spendable_txids_confirmed: Vec::new(),
1145
1146                         best_block,
1147                         counterparty_node_id: Some(counterparty_node_id),
1148                 })
1149         }
1150
1151         #[cfg(test)]
1152         fn provide_secret(&self, idx: u64, secret: [u8; 32]) -> Result<(), &'static str> {
1153                 self.inner.lock().unwrap().provide_secret(idx, secret)
1154         }
1155
1156         /// Informs this monitor of the latest counterparty (ie non-broadcastable) commitment transaction.
1157         /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1158         /// possibly future revocation/preimage information) to claim outputs where possible.
1159         /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1160         pub(crate) fn provide_latest_counterparty_commitment_tx<L: Deref>(
1161                 &self,
1162                 txid: Txid,
1163                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
1164                 commitment_number: u64,
1165                 their_per_commitment_point: PublicKey,
1166                 logger: &L,
1167         ) where L::Target: Logger {
1168                 self.inner.lock().unwrap().provide_latest_counterparty_commitment_tx(
1169                         txid, htlc_outputs, commitment_number, their_per_commitment_point, logger)
1170         }
1171
1172         #[cfg(test)]
1173         fn provide_latest_holder_commitment_tx(
1174                 &self, holder_commitment_tx: HolderCommitmentTransaction,
1175                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
1176         ) -> Result<(), ()> {
1177                 self.inner.lock().unwrap().provide_latest_holder_commitment_tx(holder_commitment_tx, htlc_outputs).map_err(|_| ())
1178         }
1179
1180         /// This is used to provide payment preimage(s) out-of-band during startup without updating the
1181         /// off-chain state with a new commitment transaction.
1182         pub(crate) fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(
1183                 &self,
1184                 payment_hash: &PaymentHash,
1185                 payment_preimage: &PaymentPreimage,
1186                 broadcaster: &B,
1187                 fee_estimator: &LowerBoundedFeeEstimator<F>,
1188                 logger: &L,
1189         ) where
1190                 B::Target: BroadcasterInterface,
1191                 F::Target: FeeEstimator,
1192                 L::Target: Logger,
1193         {
1194                 self.inner.lock().unwrap().provide_payment_preimage(
1195                         payment_hash, payment_preimage, broadcaster, fee_estimator, logger)
1196         }
1197
1198         pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(
1199                 &self,
1200                 broadcaster: &B,
1201                 logger: &L,
1202         ) where
1203                 B::Target: BroadcasterInterface,
1204                 L::Target: Logger,
1205         {
1206                 self.inner.lock().unwrap().broadcast_latest_holder_commitment_txn(broadcaster, logger);
1207         }
1208
1209         /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1210         /// itself.
1211         ///
1212         /// panics if the given update is not the next update by update_id.
1213         pub fn update_monitor<B: Deref, F: Deref, L: Deref>(
1214                 &self,
1215                 updates: &ChannelMonitorUpdate,
1216                 broadcaster: &B,
1217                 fee_estimator: F,
1218                 logger: &L,
1219         ) -> Result<(), ()>
1220         where
1221                 B::Target: BroadcasterInterface,
1222                 F::Target: FeeEstimator,
1223                 L::Target: Logger,
1224         {
1225                 self.inner.lock().unwrap().update_monitor(updates, broadcaster, fee_estimator, logger)
1226         }
1227
1228         /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1229         /// ChannelMonitor.
1230         pub fn get_latest_update_id(&self) -> u64 {
1231                 self.inner.lock().unwrap().get_latest_update_id()
1232         }
1233
1234         /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1235         pub fn get_funding_txo(&self) -> (OutPoint, Script) {
1236                 self.inner.lock().unwrap().get_funding_txo().clone()
1237         }
1238
1239         /// Gets a list of txids, with their output scripts (in the order they appear in the
1240         /// transaction), which we must learn about spends of via block_connected().
1241         pub fn get_outputs_to_watch(&self) -> Vec<(Txid, Vec<(u32, Script)>)> {
1242                 self.inner.lock().unwrap().get_outputs_to_watch()
1243                         .iter().map(|(txid, outputs)| (*txid, outputs.clone())).collect()
1244         }
1245
1246         /// Loads the funding txo and outputs to watch into the given `chain::Filter` by repeatedly
1247         /// calling `chain::Filter::register_output` and `chain::Filter::register_tx` until all outputs
1248         /// have been registered.
1249         pub fn load_outputs_to_watch<F: Deref>(&self, filter: &F) where F::Target: chain::Filter {
1250                 let lock = self.inner.lock().unwrap();
1251                 filter.register_tx(&lock.get_funding_txo().0.txid, &lock.get_funding_txo().1);
1252                 for (txid, outputs) in lock.get_outputs_to_watch().iter() {
1253                         for (index, script_pubkey) in outputs.iter() {
1254                                 assert!(*index <= u16::max_value() as u32);
1255                                 filter.register_output(WatchedOutput {
1256                                         block_hash: None,
1257                                         outpoint: OutPoint { txid: *txid, index: *index as u16 },
1258                                         script_pubkey: script_pubkey.clone(),
1259                                 });
1260                         }
1261                 }
1262         }
1263
1264         /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1265         /// ChannelManager via [`chain::Watch::release_pending_monitor_events`].
1266         pub fn get_and_clear_pending_monitor_events(&self) -> Vec<MonitorEvent> {
1267                 self.inner.lock().unwrap().get_and_clear_pending_monitor_events()
1268         }
1269
1270         /// Gets the list of pending events which were generated by previous actions, clearing the list
1271         /// in the process.
1272         ///
1273         /// This is called by the [`EventsProvider::process_pending_events`] implementation for
1274         /// [`ChainMonitor`].
1275         ///
1276         /// [`EventsProvider::process_pending_events`]: crate::util::events::EventsProvider::process_pending_events
1277         /// [`ChainMonitor`]: crate::chain::chainmonitor::ChainMonitor
1278         pub fn get_and_clear_pending_events(&self) -> Vec<Event> {
1279                 self.inner.lock().unwrap().get_and_clear_pending_events()
1280         }
1281
1282         pub(crate) fn get_min_seen_secret(&self) -> u64 {
1283                 self.inner.lock().unwrap().get_min_seen_secret()
1284         }
1285
1286         pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1287                 self.inner.lock().unwrap().get_cur_counterparty_commitment_number()
1288         }
1289
1290         pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
1291                 self.inner.lock().unwrap().get_cur_holder_commitment_number()
1292         }
1293
1294         /// Gets the `node_id` of the counterparty for this channel.
1295         ///
1296         /// Will be `None` for channels constructed on LDK versions prior to 0.0.110 and always `Some`
1297         /// otherwise.
1298         pub fn get_counterparty_node_id(&self) -> Option<PublicKey> {
1299                 self.inner.lock().unwrap().counterparty_node_id
1300         }
1301
1302         /// Used by ChannelManager deserialization to broadcast the latest holder state if its copy of
1303         /// the Channel was out-of-date.
1304         ///
1305         /// You may also use this to broadcast the latest local commitment transaction, either because
1306         /// a monitor update failed with [`ChannelMonitorUpdateStatus::PermanentFailure`] or because we've
1307         /// fallen behind (i.e. we've received proof that our counterparty side knows a revocation
1308         /// secret we gave them that they shouldn't know).
1309         ///
1310         /// Broadcasting these transactions in the second case is UNSAFE, as they allow counterparty
1311         /// side to punish you. Nevertheless you may want to broadcast them if counterparty doesn't
1312         /// close channel with their commitment transaction after a substantial amount of time. Best
1313         /// may be to contact the other node operator out-of-band to coordinate other options available
1314         /// to you. In any-case, the choice is up to you.
1315         ///
1316         /// [`ChannelMonitorUpdateStatus::PermanentFailure`]: super::ChannelMonitorUpdateStatus::PermanentFailure
1317         pub fn get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1318         where L::Target: Logger {
1319                 self.inner.lock().unwrap().get_latest_holder_commitment_txn(logger)
1320         }
1321
1322         /// Unsafe test-only version of get_latest_holder_commitment_txn used by our test framework
1323         /// to bypass HolderCommitmentTransaction state update lockdown after signature and generate
1324         /// revoked commitment transaction.
1325         #[cfg(any(test, feature = "unsafe_revoked_tx_signing"))]
1326         pub fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1327         where L::Target: Logger {
1328                 self.inner.lock().unwrap().unsafe_get_latest_holder_commitment_txn(logger)
1329         }
1330
1331         /// Processes transactions in a newly connected block, which may result in any of the following:
1332         /// - update the monitor's state against resolved HTLCs
1333         /// - punish the counterparty in the case of seeing a revoked commitment transaction
1334         /// - force close the channel and claim/timeout incoming/outgoing HTLCs if near expiration
1335         /// - detect settled outputs for later spending
1336         /// - schedule and bump any in-flight claims
1337         ///
1338         /// Returns any new outputs to watch from `txdata`; after called, these are also included in
1339         /// [`get_outputs_to_watch`].
1340         ///
1341         /// [`get_outputs_to_watch`]: #method.get_outputs_to_watch
1342         pub fn block_connected<B: Deref, F: Deref, L: Deref>(
1343                 &self,
1344                 header: &BlockHeader,
1345                 txdata: &TransactionData,
1346                 height: u32,
1347                 broadcaster: B,
1348                 fee_estimator: F,
1349                 logger: L,
1350         ) -> Vec<TransactionOutputs>
1351         where
1352                 B::Target: BroadcasterInterface,
1353                 F::Target: FeeEstimator,
1354                 L::Target: Logger,
1355         {
1356                 self.inner.lock().unwrap().block_connected(
1357                         header, txdata, height, broadcaster, fee_estimator, logger)
1358         }
1359
1360         /// Determines if the disconnected block contained any transactions of interest and updates
1361         /// appropriately.
1362         pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(
1363                 &self,
1364                 header: &BlockHeader,
1365                 height: u32,
1366                 broadcaster: B,
1367                 fee_estimator: F,
1368                 logger: L,
1369         ) where
1370                 B::Target: BroadcasterInterface,
1371                 F::Target: FeeEstimator,
1372                 L::Target: Logger,
1373         {
1374                 self.inner.lock().unwrap().block_disconnected(
1375                         header, height, broadcaster, fee_estimator, logger)
1376         }
1377
1378         /// Processes transactions confirmed in a block with the given header and height, returning new
1379         /// outputs to watch. See [`block_connected`] for details.
1380         ///
1381         /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
1382         /// blocks. See [`chain::Confirm`] for calling expectations.
1383         ///
1384         /// [`block_connected`]: Self::block_connected
1385         pub fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
1386                 &self,
1387                 header: &BlockHeader,
1388                 txdata: &TransactionData,
1389                 height: u32,
1390                 broadcaster: B,
1391                 fee_estimator: F,
1392                 logger: L,
1393         ) -> Vec<TransactionOutputs>
1394         where
1395                 B::Target: BroadcasterInterface,
1396                 F::Target: FeeEstimator,
1397                 L::Target: Logger,
1398         {
1399                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1400                 self.inner.lock().unwrap().transactions_confirmed(
1401                         header, txdata, height, broadcaster, &bounded_fee_estimator, logger)
1402         }
1403
1404         /// Processes a transaction that was reorganized out of the chain.
1405         ///
1406         /// Used instead of [`block_disconnected`] by clients that are notified of transactions rather
1407         /// than blocks. See [`chain::Confirm`] for calling expectations.
1408         ///
1409         /// [`block_disconnected`]: Self::block_disconnected
1410         pub fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
1411                 &self,
1412                 txid: &Txid,
1413                 broadcaster: B,
1414                 fee_estimator: F,
1415                 logger: L,
1416         ) where
1417                 B::Target: BroadcasterInterface,
1418                 F::Target: FeeEstimator,
1419                 L::Target: Logger,
1420         {
1421                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1422                 self.inner.lock().unwrap().transaction_unconfirmed(
1423                         txid, broadcaster, &bounded_fee_estimator, logger);
1424         }
1425
1426         /// Updates the monitor with the current best chain tip, returning new outputs to watch. See
1427         /// [`block_connected`] for details.
1428         ///
1429         /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
1430         /// blocks. See [`chain::Confirm`] for calling expectations.
1431         ///
1432         /// [`block_connected`]: Self::block_connected
1433         pub fn best_block_updated<B: Deref, F: Deref, L: Deref>(
1434                 &self,
1435                 header: &BlockHeader,
1436                 height: u32,
1437                 broadcaster: B,
1438                 fee_estimator: F,
1439                 logger: L,
1440         ) -> Vec<TransactionOutputs>
1441         where
1442                 B::Target: BroadcasterInterface,
1443                 F::Target: FeeEstimator,
1444                 L::Target: Logger,
1445         {
1446                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1447                 self.inner.lock().unwrap().best_block_updated(
1448                         header, height, broadcaster, &bounded_fee_estimator, logger)
1449         }
1450
1451         /// Returns the set of txids that should be monitored for re-organization out of the chain.
1452         pub fn get_relevant_txids(&self) -> Vec<(Txid, Option<BlockHash>)> {
1453                 let inner = self.inner.lock().unwrap();
1454                 let mut txids: Vec<(Txid, Option<BlockHash>)> = inner.onchain_events_awaiting_threshold_conf
1455                         .iter()
1456                         .map(|entry| (entry.txid, entry.block_hash))
1457                         .chain(inner.onchain_tx_handler.get_relevant_txids().into_iter())
1458                         .collect();
1459                 txids.sort_unstable();
1460                 txids.dedup();
1461                 txids
1462         }
1463
1464         /// Gets the latest best block which was connected either via the [`chain::Listen`] or
1465         /// [`chain::Confirm`] interfaces.
1466         pub fn current_best_block(&self) -> BestBlock {
1467                 self.inner.lock().unwrap().best_block.clone()
1468         }
1469 }
1470
1471 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
1472         /// Helper for get_claimable_balances which does the work for an individual HTLC, generating up
1473         /// to one `Balance` for the HTLC.
1474         fn get_htlc_balance(&self, htlc: &HTLCOutputInCommitment, holder_commitment: bool,
1475                 counterparty_revoked_commitment: bool, confirmed_txid: Option<Txid>)
1476         -> Option<Balance> {
1477                 let htlc_commitment_tx_output_idx =
1478                         if let Some(v) = htlc.transaction_output_index { v } else { return None; };
1479
1480                 let mut htlc_spend_txid_opt = None;
1481                 let mut htlc_spend_tx_opt = None;
1482                 let mut holder_timeout_spend_pending = None;
1483                 let mut htlc_spend_pending = None;
1484                 let mut holder_delayed_output_pending = None;
1485                 for event in self.onchain_events_awaiting_threshold_conf.iter() {
1486                         match event.event {
1487                                 OnchainEvent::HTLCUpdate { commitment_tx_output_idx, htlc_value_satoshis, .. }
1488                                 if commitment_tx_output_idx == Some(htlc_commitment_tx_output_idx) => {
1489                                         debug_assert!(htlc_spend_txid_opt.is_none());
1490                                         htlc_spend_txid_opt = Some(&event.txid);
1491                                         debug_assert!(htlc_spend_tx_opt.is_none());
1492                                         htlc_spend_tx_opt = event.transaction.as_ref();
1493                                         debug_assert!(holder_timeout_spend_pending.is_none());
1494                                         debug_assert_eq!(htlc_value_satoshis.unwrap(), htlc.amount_msat / 1000);
1495                                         holder_timeout_spend_pending = Some(event.confirmation_threshold());
1496                                 },
1497                                 OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, preimage, .. }
1498                                 if commitment_tx_output_idx == htlc_commitment_tx_output_idx => {
1499                                         debug_assert!(htlc_spend_txid_opt.is_none());
1500                                         htlc_spend_txid_opt = Some(&event.txid);
1501                                         debug_assert!(htlc_spend_tx_opt.is_none());
1502                                         htlc_spend_tx_opt = event.transaction.as_ref();
1503                                         debug_assert!(htlc_spend_pending.is_none());
1504                                         htlc_spend_pending = Some((event.confirmation_threshold(), preimage.is_some()));
1505                                 },
1506                                 OnchainEvent::MaturingOutput {
1507                                         descriptor: SpendableOutputDescriptor::DelayedPaymentOutput(ref descriptor) }
1508                                 if descriptor.outpoint.index as u32 == htlc_commitment_tx_output_idx => {
1509                                         debug_assert!(holder_delayed_output_pending.is_none());
1510                                         holder_delayed_output_pending = Some(event.confirmation_threshold());
1511                                 },
1512                                 _ => {},
1513                         }
1514                 }
1515                 let htlc_resolved = self.htlcs_resolved_on_chain.iter()
1516                         .find(|v| if v.commitment_tx_output_idx == Some(htlc_commitment_tx_output_idx) {
1517                                 debug_assert!(htlc_spend_txid_opt.is_none());
1518                                 htlc_spend_txid_opt = v.resolving_txid.as_ref();
1519                                 debug_assert!(htlc_spend_tx_opt.is_none());
1520                                 htlc_spend_tx_opt = v.resolving_tx.as_ref();
1521                                 true
1522                         } else { false });
1523                 debug_assert!(holder_timeout_spend_pending.is_some() as u8 + htlc_spend_pending.is_some() as u8 + htlc_resolved.is_some() as u8 <= 1);
1524
1525                 let htlc_commitment_outpoint = BitcoinOutPoint::new(confirmed_txid.unwrap(), htlc_commitment_tx_output_idx);
1526                 let htlc_output_to_spend =
1527                         if let Some(txid) = htlc_spend_txid_opt {
1528                                 // Because HTLC transactions either only have 1 input and 1 output (pre-anchors) or
1529                                 // are signed with SIGHASH_SINGLE|ANYONECANPAY under BIP-0143 (post-anchors), we can
1530                                 // locate the correct output by ensuring its adjacent input spends the HTLC output
1531                                 // in the commitment.
1532                                 if let Some(ref tx) = htlc_spend_tx_opt {
1533                                         let htlc_input_idx_opt = tx.input.iter().enumerate()
1534                                                 .find(|(_, input)| input.previous_output == htlc_commitment_outpoint)
1535                                                 .map(|(idx, _)| idx as u32);
1536                                         debug_assert!(htlc_input_idx_opt.is_some());
1537                                         BitcoinOutPoint::new(*txid, htlc_input_idx_opt.unwrap_or(0))
1538                                 } else {
1539                                         debug_assert!(!self.onchain_tx_handler.opt_anchors());
1540                                         BitcoinOutPoint::new(*txid, 0)
1541                                 }
1542                         } else {
1543                                 htlc_commitment_outpoint
1544                         };
1545                 let htlc_output_spend_pending = self.onchain_tx_handler.is_output_spend_pending(&htlc_output_to_spend);
1546
1547                 if let Some(conf_thresh) = holder_delayed_output_pending {
1548                         debug_assert!(holder_commitment);
1549                         return Some(Balance::ClaimableAwaitingConfirmations {
1550                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1551                                 confirmation_height: conf_thresh,
1552                         });
1553                 } else if htlc_resolved.is_some() && !htlc_output_spend_pending {
1554                         // Funding transaction spends should be fully confirmed by the time any
1555                         // HTLC transactions are resolved, unless we're talking about a holder
1556                         // commitment tx, whose resolution is delayed until the CSV timeout is
1557                         // reached, even though HTLCs may be resolved after only
1558                         // ANTI_REORG_DELAY confirmations.
1559                         debug_assert!(holder_commitment || self.funding_spend_confirmed.is_some());
1560                 } else if counterparty_revoked_commitment {
1561                         let htlc_output_claim_pending = self.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1562                                 if let OnchainEvent::MaturingOutput {
1563                                         descriptor: SpendableOutputDescriptor::StaticOutput { .. }
1564                                 } = &event.event {
1565                                         if event.transaction.as_ref().map(|tx| tx.input.iter().any(|inp| {
1566                                                 if let Some(htlc_spend_txid) = htlc_spend_txid_opt {
1567                                                         tx.txid() == *htlc_spend_txid || inp.previous_output.txid == *htlc_spend_txid
1568                                                 } else {
1569                                                         Some(inp.previous_output.txid) == confirmed_txid &&
1570                                                                 inp.previous_output.vout == htlc_commitment_tx_output_idx
1571                                                 }
1572                                         })).unwrap_or(false) {
1573                                                 Some(())
1574                                         } else { None }
1575                                 } else { None }
1576                         });
1577                         if htlc_output_claim_pending.is_some() {
1578                                 // We already push `Balance`s onto the `res` list for every
1579                                 // `StaticOutput` in a `MaturingOutput` in the revoked
1580                                 // counterparty commitment transaction case generally, so don't
1581                                 // need to do so again here.
1582                         } else {
1583                                 debug_assert!(holder_timeout_spend_pending.is_none(),
1584                                         "HTLCUpdate OnchainEvents should never appear for preimage claims");
1585                                 debug_assert!(!htlc.offered || htlc_spend_pending.is_none() || !htlc_spend_pending.unwrap().1,
1586                                         "We don't (currently) generate preimage claims against revoked outputs, where did you get one?!");
1587                                 return Some(Balance::CounterpartyRevokedOutputClaimable {
1588                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1589                                 });
1590                         }
1591                 } else if htlc.offered == holder_commitment {
1592                         // If the payment was outbound, check if there's an HTLCUpdate
1593                         // indicating we have spent this HTLC with a timeout, claiming it back
1594                         // and awaiting confirmations on it.
1595                         if let Some(conf_thresh) = holder_timeout_spend_pending {
1596                                 return Some(Balance::ClaimableAwaitingConfirmations {
1597                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1598                                         confirmation_height: conf_thresh,
1599                                 });
1600                         } else {
1601                                 return Some(Balance::MaybeTimeoutClaimableHTLC {
1602                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1603                                         claimable_height: htlc.cltv_expiry,
1604                                 });
1605                         }
1606                 } else if self.payment_preimages.get(&htlc.payment_hash).is_some() {
1607                         // Otherwise (the payment was inbound), only expose it as claimable if
1608                         // we know the preimage.
1609                         // Note that if there is a pending claim, but it did not use the
1610                         // preimage, we lost funds to our counterparty! We will then continue
1611                         // to show it as ContentiousClaimable until ANTI_REORG_DELAY.
1612                         debug_assert!(holder_timeout_spend_pending.is_none());
1613                         if let Some((conf_thresh, true)) = htlc_spend_pending {
1614                                 return Some(Balance::ClaimableAwaitingConfirmations {
1615                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1616                                         confirmation_height: conf_thresh,
1617                                 });
1618                         } else {
1619                                 return Some(Balance::ContentiousClaimable {
1620                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1621                                         timeout_height: htlc.cltv_expiry,
1622                                 });
1623                         }
1624                 } else if htlc_resolved.is_none() {
1625                         return Some(Balance::MaybePreimageClaimableHTLC {
1626                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1627                                 expiry_height: htlc.cltv_expiry,
1628                         });
1629                 }
1630                 None
1631         }
1632 }
1633
1634 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
1635         /// Gets the balances in this channel which are either claimable by us if we were to
1636         /// force-close the channel now or which are claimable on-chain (possibly awaiting
1637         /// confirmation).
1638         ///
1639         /// Any balances in the channel which are available on-chain (excluding on-chain fees) are
1640         /// included here until an [`Event::SpendableOutputs`] event has been generated for the
1641         /// balance, or until our counterparty has claimed the balance and accrued several
1642         /// confirmations on the claim transaction.
1643         ///
1644         /// Note that for `ChannelMonitors` which track a channel which went on-chain with versions of
1645         /// LDK prior to 0.0.111, balances may not be fully captured if our counterparty broadcasted
1646         /// a revoked state.
1647         ///
1648         /// See [`Balance`] for additional details on the types of claimable balances which
1649         /// may be returned here and their meanings.
1650         pub fn get_claimable_balances(&self) -> Vec<Balance> {
1651                 let mut res = Vec::new();
1652                 let us = self.inner.lock().unwrap();
1653
1654                 let mut confirmed_txid = us.funding_spend_confirmed;
1655                 let mut confirmed_counterparty_output = us.confirmed_commitment_tx_counterparty_output;
1656                 let mut pending_commitment_tx_conf_thresh = None;
1657                 let funding_spend_pending = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1658                         if let OnchainEvent::FundingSpendConfirmation { commitment_tx_to_counterparty_output, .. } =
1659                                 event.event
1660                         {
1661                                 confirmed_counterparty_output = commitment_tx_to_counterparty_output;
1662                                 Some((event.txid, event.confirmation_threshold()))
1663                         } else { None }
1664                 });
1665                 if let Some((txid, conf_thresh)) = funding_spend_pending {
1666                         debug_assert!(us.funding_spend_confirmed.is_none(),
1667                                 "We have a pending funding spend awaiting anti-reorg confirmation, we can't have confirmed it already!");
1668                         confirmed_txid = Some(txid);
1669                         pending_commitment_tx_conf_thresh = Some(conf_thresh);
1670                 }
1671
1672                 macro_rules! walk_htlcs {
1673                         ($holder_commitment: expr, $counterparty_revoked_commitment: expr, $htlc_iter: expr) => {
1674                                 for htlc in $htlc_iter {
1675                                         if htlc.transaction_output_index.is_some() {
1676
1677                                                 if let Some(bal) = us.get_htlc_balance(htlc, $holder_commitment, $counterparty_revoked_commitment, confirmed_txid) {
1678                                                         res.push(bal);
1679                                                 }
1680                                         }
1681                                 }
1682                         }
1683                 }
1684
1685                 if let Some(txid) = confirmed_txid {
1686                         let mut found_commitment_tx = false;
1687                         if let Some(counterparty_tx_htlcs) = us.counterparty_claimable_outpoints.get(&txid) {
1688                                 // First look for the to_remote output back to us.
1689                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1690                                         if let Some(value) = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1691                                                 if let OnchainEvent::MaturingOutput {
1692                                                         descriptor: SpendableOutputDescriptor::StaticPaymentOutput(descriptor)
1693                                                 } = &event.event {
1694                                                         Some(descriptor.output.value)
1695                                                 } else { None }
1696                                         }) {
1697                                                 res.push(Balance::ClaimableAwaitingConfirmations {
1698                                                         claimable_amount_satoshis: value,
1699                                                         confirmation_height: conf_thresh,
1700                                                 });
1701                                         } else {
1702                                                 // If a counterparty commitment transaction is awaiting confirmation, we
1703                                                 // should either have a StaticPaymentOutput MaturingOutput event awaiting
1704                                                 // confirmation with the same height or have never met our dust amount.
1705                                         }
1706                                 }
1707                                 if Some(txid) == us.current_counterparty_commitment_txid || Some(txid) == us.prev_counterparty_commitment_txid {
1708                                         walk_htlcs!(false, false, counterparty_tx_htlcs.iter().map(|(a, _)| a));
1709                                 } else {
1710                                         walk_htlcs!(false, true, counterparty_tx_htlcs.iter().map(|(a, _)| a));
1711                                         // The counterparty broadcasted a revoked state!
1712                                         // Look for any StaticOutputs first, generating claimable balances for those.
1713                                         // If any match the confirmed counterparty revoked to_self output, skip
1714                                         // generating a CounterpartyRevokedOutputClaimable.
1715                                         let mut spent_counterparty_output = false;
1716                                         for event in us.onchain_events_awaiting_threshold_conf.iter() {
1717                                                 if let OnchainEvent::MaturingOutput {
1718                                                         descriptor: SpendableOutputDescriptor::StaticOutput { output, .. }
1719                                                 } = &event.event {
1720                                                         res.push(Balance::ClaimableAwaitingConfirmations {
1721                                                                 claimable_amount_satoshis: output.value,
1722                                                                 confirmation_height: event.confirmation_threshold(),
1723                                                         });
1724                                                         if let Some(confirmed_to_self_idx) = confirmed_counterparty_output.map(|(idx, _)| idx) {
1725                                                                 if event.transaction.as_ref().map(|tx|
1726                                                                         tx.input.iter().any(|inp| inp.previous_output.vout == confirmed_to_self_idx)
1727                                                                 ).unwrap_or(false) {
1728                                                                         spent_counterparty_output = true;
1729                                                                 }
1730                                                         }
1731                                                 }
1732                                         }
1733
1734                                         if spent_counterparty_output {
1735                                         } else if let Some((confirmed_to_self_idx, amt)) = confirmed_counterparty_output {
1736                                                 let output_spendable = us.onchain_tx_handler
1737                                                         .is_output_spend_pending(&BitcoinOutPoint::new(txid, confirmed_to_self_idx));
1738                                                 if output_spendable {
1739                                                         res.push(Balance::CounterpartyRevokedOutputClaimable {
1740                                                                 claimable_amount_satoshis: amt,
1741                                                         });
1742                                                 }
1743                                         } else {
1744                                                 // Counterparty output is missing, either it was broadcasted on a
1745                                                 // previous version of LDK or the counterparty hadn't met dust.
1746                                         }
1747                                 }
1748                                 found_commitment_tx = true;
1749                         } else if txid == us.current_holder_commitment_tx.txid {
1750                                 walk_htlcs!(true, false, us.current_holder_commitment_tx.htlc_outputs.iter().map(|(a, _, _)| a));
1751                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1752                                         res.push(Balance::ClaimableAwaitingConfirmations {
1753                                                 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
1754                                                 confirmation_height: conf_thresh,
1755                                         });
1756                                 }
1757                                 found_commitment_tx = true;
1758                         } else if let Some(prev_commitment) = &us.prev_holder_signed_commitment_tx {
1759                                 if txid == prev_commitment.txid {
1760                                         walk_htlcs!(true, false, prev_commitment.htlc_outputs.iter().map(|(a, _, _)| a));
1761                                         if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1762                                                 res.push(Balance::ClaimableAwaitingConfirmations {
1763                                                         claimable_amount_satoshis: prev_commitment.to_self_value_sat,
1764                                                         confirmation_height: conf_thresh,
1765                                                 });
1766                                         }
1767                                         found_commitment_tx = true;
1768                                 }
1769                         }
1770                         if !found_commitment_tx {
1771                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1772                                         // We blindly assume this is a cooperative close transaction here, and that
1773                                         // neither us nor our counterparty misbehaved. At worst we've under-estimated
1774                                         // the amount we can claim as we'll punish a misbehaving counterparty.
1775                                         res.push(Balance::ClaimableAwaitingConfirmations {
1776                                                 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
1777                                                 confirmation_height: conf_thresh,
1778                                         });
1779                                 }
1780                         }
1781                 } else {
1782                         let mut claimable_inbound_htlc_value_sat = 0;
1783                         for (htlc, _, _) in us.current_holder_commitment_tx.htlc_outputs.iter() {
1784                                 if htlc.transaction_output_index.is_none() { continue; }
1785                                 if htlc.offered {
1786                                         res.push(Balance::MaybeTimeoutClaimableHTLC {
1787                                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1788                                                 claimable_height: htlc.cltv_expiry,
1789                                         });
1790                                 } else if us.payment_preimages.get(&htlc.payment_hash).is_some() {
1791                                         claimable_inbound_htlc_value_sat += htlc.amount_msat / 1000;
1792                                 } else {
1793                                         // As long as the HTLC is still in our latest commitment state, treat
1794                                         // it as potentially claimable, even if it has long-since expired.
1795                                         res.push(Balance::MaybePreimageClaimableHTLC {
1796                                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1797                                                 expiry_height: htlc.cltv_expiry,
1798                                         });
1799                                 }
1800                         }
1801                         res.push(Balance::ClaimableOnChannelClose {
1802                                 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat + claimable_inbound_htlc_value_sat,
1803                         });
1804                 }
1805
1806                 res
1807         }
1808
1809         /// Gets the set of outbound HTLCs which can be (or have been) resolved by this
1810         /// `ChannelMonitor`. This is used to determine if an HTLC was removed from the channel prior
1811         /// to the `ChannelManager` having been persisted.
1812         ///
1813         /// This is similar to [`Self::get_pending_outbound_htlcs`] except it includes HTLCs which were
1814         /// resolved by this `ChannelMonitor`.
1815         pub(crate) fn get_all_current_outbound_htlcs(&self) -> HashMap<HTLCSource, HTLCOutputInCommitment> {
1816                 let mut res = HashMap::new();
1817                 // Just examine the available counterparty commitment transactions. See docs on
1818                 // `fail_unbroadcast_htlcs`, below, for justification.
1819                 let us = self.inner.lock().unwrap();
1820                 macro_rules! walk_counterparty_commitment {
1821                         ($txid: expr) => {
1822                                 if let Some(ref latest_outpoints) = us.counterparty_claimable_outpoints.get($txid) {
1823                                         for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1824                                                 if let &Some(ref source) = source_option {
1825                                                         res.insert((**source).clone(), htlc.clone());
1826                                                 }
1827                                         }
1828                                 }
1829                         }
1830                 }
1831                 if let Some(ref txid) = us.current_counterparty_commitment_txid {
1832                         walk_counterparty_commitment!(txid);
1833                 }
1834                 if let Some(ref txid) = us.prev_counterparty_commitment_txid {
1835                         walk_counterparty_commitment!(txid);
1836                 }
1837                 res
1838         }
1839
1840         /// Gets the set of outbound HTLCs which are pending resolution in this channel.
1841         /// This is used to reconstruct pending outbound payments on restart in the ChannelManager.
1842         pub(crate) fn get_pending_outbound_htlcs(&self) -> HashMap<HTLCSource, HTLCOutputInCommitment> {
1843                 let us = self.inner.lock().unwrap();
1844                 // We're only concerned with the confirmation count of HTLC transactions, and don't
1845                 // actually care how many confirmations a commitment transaction may or may not have. Thus,
1846                 // we look for either a FundingSpendConfirmation event or a funding_spend_confirmed.
1847                 let confirmed_txid = us.funding_spend_confirmed.or_else(|| {
1848                         us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1849                                 if let OnchainEvent::FundingSpendConfirmation { .. } = event.event {
1850                                         Some(event.txid)
1851                                 } else { None }
1852                         })
1853                 });
1854
1855                 if confirmed_txid.is_none() {
1856                         // If we have not seen a commitment transaction on-chain (ie the channel is not yet
1857                         // closed), just get the full set.
1858                         mem::drop(us);
1859                         return self.get_all_current_outbound_htlcs();
1860                 }
1861
1862                 let mut res = HashMap::new();
1863                 macro_rules! walk_htlcs {
1864                         ($holder_commitment: expr, $htlc_iter: expr) => {
1865                                 for (htlc, source) in $htlc_iter {
1866                                         if us.htlcs_resolved_on_chain.iter().any(|v| v.commitment_tx_output_idx == htlc.transaction_output_index) {
1867                                                 // We should assert that funding_spend_confirmed is_some() here, but we
1868                                                 // have some unit tests which violate HTLC transaction CSVs entirely and
1869                                                 // would fail.
1870                                                 // TODO: Once tests all connect transactions at consensus-valid times, we
1871                                                 // should assert here like we do in `get_claimable_balances`.
1872                                         } else if htlc.offered == $holder_commitment {
1873                                                 // If the payment was outbound, check if there's an HTLCUpdate
1874                                                 // indicating we have spent this HTLC with a timeout, claiming it back
1875                                                 // and awaiting confirmations on it.
1876                                                 let htlc_update_confd = us.onchain_events_awaiting_threshold_conf.iter().any(|event| {
1877                                                         if let OnchainEvent::HTLCUpdate { commitment_tx_output_idx: Some(commitment_tx_output_idx), .. } = event.event {
1878                                                                 // If the HTLC was timed out, we wait for ANTI_REORG_DELAY blocks
1879                                                                 // before considering it "no longer pending" - this matches when we
1880                                                                 // provide the ChannelManager an HTLC failure event.
1881                                                                 Some(commitment_tx_output_idx) == htlc.transaction_output_index &&
1882                                                                         us.best_block.height() >= event.height + ANTI_REORG_DELAY - 1
1883                                                         } else if let OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, .. } = event.event {
1884                                                                 // If the HTLC was fulfilled with a preimage, we consider the HTLC
1885                                                                 // immediately non-pending, matching when we provide ChannelManager
1886                                                                 // the preimage.
1887                                                                 Some(commitment_tx_output_idx) == htlc.transaction_output_index
1888                                                         } else { false }
1889                                                 });
1890                                                 if !htlc_update_confd {
1891                                                         res.insert(source.clone(), htlc.clone());
1892                                                 }
1893                                         }
1894                                 }
1895                         }
1896                 }
1897
1898                 let txid = confirmed_txid.unwrap();
1899                 if Some(txid) == us.current_counterparty_commitment_txid || Some(txid) == us.prev_counterparty_commitment_txid {
1900                         walk_htlcs!(false, us.counterparty_claimable_outpoints.get(&txid).unwrap().iter().filter_map(|(a, b)| {
1901                                 if let &Some(ref source) = b {
1902                                         Some((a, &**source))
1903                                 } else { None }
1904                         }));
1905                 } else if txid == us.current_holder_commitment_tx.txid {
1906                         walk_htlcs!(true, us.current_holder_commitment_tx.htlc_outputs.iter().filter_map(|(a, _, c)| {
1907                                 if let Some(source) = c { Some((a, source)) } else { None }
1908                         }));
1909                 } else if let Some(prev_commitment) = &us.prev_holder_signed_commitment_tx {
1910                         if txid == prev_commitment.txid {
1911                                 walk_htlcs!(true, prev_commitment.htlc_outputs.iter().filter_map(|(a, _, c)| {
1912                                         if let Some(source) = c { Some((a, source)) } else { None }
1913                                 }));
1914                         }
1915                 }
1916
1917                 res
1918         }
1919
1920         pub(crate) fn get_stored_preimages(&self) -> HashMap<PaymentHash, PaymentPreimage> {
1921                 self.inner.lock().unwrap().payment_preimages.clone()
1922         }
1923 }
1924
1925 /// Compares a broadcasted commitment transaction's HTLCs with those in the latest state,
1926 /// failing any HTLCs which didn't make it into the broadcasted commitment transaction back
1927 /// after ANTI_REORG_DELAY blocks.
1928 ///
1929 /// We always compare against the set of HTLCs in counterparty commitment transactions, as those
1930 /// are the commitment transactions which are generated by us. The off-chain state machine in
1931 /// `Channel` will automatically resolve any HTLCs which were never included in a commitment
1932 /// transaction when it detects channel closure, but it is up to us to ensure any HTLCs which were
1933 /// included in a remote commitment transaction are failed back if they are not present in the
1934 /// broadcasted commitment transaction.
1935 ///
1936 /// Specifically, the removal process for HTLCs in `Channel` is always based on the counterparty
1937 /// sending a `revoke_and_ack`, which causes us to clear `prev_counterparty_commitment_txid`. Thus,
1938 /// as long as we examine both the current counterparty commitment transaction and, if it hasn't
1939 /// been revoked yet, the previous one, we we will never "forget" to resolve an HTLC.
1940 macro_rules! fail_unbroadcast_htlcs {
1941         ($self: expr, $commitment_tx_type: expr, $commitment_txid_confirmed: expr, $commitment_tx_confirmed: expr,
1942          $commitment_tx_conf_height: expr, $commitment_tx_conf_hash: expr, $confirmed_htlcs_list: expr, $logger: expr) => { {
1943                 debug_assert_eq!($commitment_tx_confirmed.txid(), $commitment_txid_confirmed);
1944
1945                 macro_rules! check_htlc_fails {
1946                         ($txid: expr, $commitment_tx: expr) => {
1947                                 if let Some(ref latest_outpoints) = $self.counterparty_claimable_outpoints.get($txid) {
1948                                         for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1949                                                 if let &Some(ref source) = source_option {
1950                                                         // Check if the HTLC is present in the commitment transaction that was
1951                                                         // broadcast, but not if it was below the dust limit, which we should
1952                                                         // fail backwards immediately as there is no way for us to learn the
1953                                                         // payment_preimage.
1954                                                         // Note that if the dust limit were allowed to change between
1955                                                         // commitment transactions we'd want to be check whether *any*
1956                                                         // broadcastable commitment transaction has the HTLC in it, but it
1957                                                         // cannot currently change after channel initialization, so we don't
1958                                                         // need to here.
1959                                                         let confirmed_htlcs_iter: &mut Iterator<Item = (&HTLCOutputInCommitment, Option<&HTLCSource>)> = &mut $confirmed_htlcs_list;
1960
1961                                                         let mut matched_htlc = false;
1962                                                         for (ref broadcast_htlc, ref broadcast_source) in confirmed_htlcs_iter {
1963                                                                 if broadcast_htlc.transaction_output_index.is_some() &&
1964                                                                         (Some(&**source) == *broadcast_source ||
1965                                                                          (broadcast_source.is_none() &&
1966                                                                           broadcast_htlc.payment_hash == htlc.payment_hash &&
1967                                                                           broadcast_htlc.amount_msat == htlc.amount_msat)) {
1968                                                                         matched_htlc = true;
1969                                                                         break;
1970                                                                 }
1971                                                         }
1972                                                         if matched_htlc { continue; }
1973                                                         $self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
1974                                                                 if entry.height != $commitment_tx_conf_height { return true; }
1975                                                                 match entry.event {
1976                                                                         OnchainEvent::HTLCUpdate { source: ref update_source, .. } => {
1977                                                                                 *update_source != **source
1978                                                                         },
1979                                                                         _ => true,
1980                                                                 }
1981                                                         });
1982                                                         let entry = OnchainEventEntry {
1983                                                                 txid: $commitment_txid_confirmed,
1984                                                                 transaction: Some($commitment_tx_confirmed.clone()),
1985                                                                 height: $commitment_tx_conf_height,
1986                                                                 block_hash: Some(*$commitment_tx_conf_hash),
1987                                                                 event: OnchainEvent::HTLCUpdate {
1988                                                                         source: (**source).clone(),
1989                                                                         payment_hash: htlc.payment_hash.clone(),
1990                                                                         htlc_value_satoshis: Some(htlc.amount_msat / 1000),
1991                                                                         commitment_tx_output_idx: None,
1992                                                                 },
1993                                                         };
1994                                                         log_trace!($logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of {} commitment transaction {}, waiting for confirmation (at height {})",
1995                                                                 log_bytes!(htlc.payment_hash.0), $commitment_tx, $commitment_tx_type,
1996                                                                 $commitment_txid_confirmed, entry.confirmation_threshold());
1997                                                         $self.onchain_events_awaiting_threshold_conf.push(entry);
1998                                                 }
1999                                         }
2000                                 }
2001                         }
2002                 }
2003                 if let Some(ref txid) = $self.current_counterparty_commitment_txid {
2004                         check_htlc_fails!(txid, "current");
2005                 }
2006                 if let Some(ref txid) = $self.prev_counterparty_commitment_txid {
2007                         check_htlc_fails!(txid, "previous");
2008                 }
2009         } }
2010 }
2011
2012 // In the `test_invalid_funding_tx` test, we need a bogus script which matches the HTLC-Accepted
2013 // witness length match (ie is 136 bytes long). We generate one here which we also use in some
2014 // in-line tests later.
2015
2016 #[cfg(test)]
2017 pub fn deliberately_bogus_accepted_htlc_witness_program() -> Vec<u8> {
2018         let mut ret = [opcodes::all::OP_NOP.to_u8(); 136];
2019         ret[131] = opcodes::all::OP_DROP.to_u8();
2020         ret[132] = opcodes::all::OP_DROP.to_u8();
2021         ret[133] = opcodes::all::OP_DROP.to_u8();
2022         ret[134] = opcodes::all::OP_DROP.to_u8();
2023         ret[135] = opcodes::OP_TRUE.to_u8();
2024         Vec::from(&ret[..])
2025 }
2026
2027 #[cfg(test)]
2028 pub fn deliberately_bogus_accepted_htlc_witness() -> Vec<Vec<u8>> {
2029         vec![Vec::new(), Vec::new(), Vec::new(), Vec::new(), deliberately_bogus_accepted_htlc_witness_program().into()].into()
2030 }
2031
2032 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
2033         /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
2034         /// needed by holder commitment transactions HTCLs nor by counterparty ones. Unless we haven't already seen
2035         /// counterparty commitment transaction's secret, they are de facto pruned (we can use revocation key).
2036         fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), &'static str> {
2037                 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
2038                         return Err("Previous secret did not match new one");
2039                 }
2040
2041                 // Prune HTLCs from the previous counterparty commitment tx so we don't generate failure/fulfill
2042                 // events for now-revoked/fulfilled HTLCs.
2043                 if let Some(txid) = self.prev_counterparty_commitment_txid.take() {
2044                         for &mut (_, ref mut source) in self.counterparty_claimable_outpoints.get_mut(&txid).unwrap() {
2045                                 *source = None;
2046                         }
2047                 }
2048
2049                 if !self.payment_preimages.is_empty() {
2050                         let cur_holder_signed_commitment_tx = &self.current_holder_commitment_tx;
2051                         let prev_holder_signed_commitment_tx = self.prev_holder_signed_commitment_tx.as_ref();
2052                         let min_idx = self.get_min_seen_secret();
2053                         let counterparty_hash_commitment_number = &mut self.counterparty_hash_commitment_number;
2054
2055                         self.payment_preimages.retain(|&k, _| {
2056                                 for &(ref htlc, _, _) in cur_holder_signed_commitment_tx.htlc_outputs.iter() {
2057                                         if k == htlc.payment_hash {
2058                                                 return true
2059                                         }
2060                                 }
2061                                 if let Some(prev_holder_commitment_tx) = prev_holder_signed_commitment_tx {
2062                                         for &(ref htlc, _, _) in prev_holder_commitment_tx.htlc_outputs.iter() {
2063                                                 if k == htlc.payment_hash {
2064                                                         return true
2065                                                 }
2066                                         }
2067                                 }
2068                                 let contains = if let Some(cn) = counterparty_hash_commitment_number.get(&k) {
2069                                         if *cn < min_idx {
2070                                                 return true
2071                                         }
2072                                         true
2073                                 } else { false };
2074                                 if contains {
2075                                         counterparty_hash_commitment_number.remove(&k);
2076                                 }
2077                                 false
2078                         });
2079                 }
2080
2081                 Ok(())
2082         }
2083
2084         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 {
2085                 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
2086                 // so that a remote monitor doesn't learn anything unless there is a malicious close.
2087                 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
2088                 // timeouts)
2089                 for &(ref htlc, _) in &htlc_outputs {
2090                         self.counterparty_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
2091                 }
2092
2093                 log_trace!(logger, "Tracking new counterparty commitment transaction with txid {} at commitment number {} with {} HTLC outputs", txid, commitment_number, htlc_outputs.len());
2094                 self.prev_counterparty_commitment_txid = self.current_counterparty_commitment_txid.take();
2095                 self.current_counterparty_commitment_txid = Some(txid);
2096                 self.counterparty_claimable_outpoints.insert(txid, htlc_outputs.clone());
2097                 self.current_counterparty_commitment_number = commitment_number;
2098                 //TODO: Merge this into the other per-counterparty-transaction output storage stuff
2099                 match self.their_cur_per_commitment_points {
2100                         Some(old_points) => {
2101                                 if old_points.0 == commitment_number + 1 {
2102                                         self.their_cur_per_commitment_points = Some((old_points.0, old_points.1, Some(their_per_commitment_point)));
2103                                 } else if old_points.0 == commitment_number + 2 {
2104                                         if let Some(old_second_point) = old_points.2 {
2105                                                 self.their_cur_per_commitment_points = Some((old_points.0 - 1, old_second_point, Some(their_per_commitment_point)));
2106                                         } else {
2107                                                 self.their_cur_per_commitment_points = Some((commitment_number, their_per_commitment_point, None));
2108                                         }
2109                                 } else {
2110                                         self.their_cur_per_commitment_points = Some((commitment_number, their_per_commitment_point, None));
2111                                 }
2112                         },
2113                         None => {
2114                                 self.their_cur_per_commitment_points = Some((commitment_number, their_per_commitment_point, None));
2115                         }
2116                 }
2117                 let mut htlcs = Vec::with_capacity(htlc_outputs.len());
2118                 for htlc in htlc_outputs {
2119                         if htlc.0.transaction_output_index.is_some() {
2120                                 htlcs.push(htlc.0);
2121                         }
2122                 }
2123         }
2124
2125         /// Informs this monitor of the latest holder (ie broadcastable) commitment transaction. The
2126         /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
2127         /// is important that any clones of this channel monitor (including remote clones) by kept
2128         /// up-to-date as our holder commitment transaction is updated.
2129         /// Panics if set_on_holder_tx_csv has never been called.
2130         fn provide_latest_holder_commitment_tx(&mut self, holder_commitment_tx: HolderCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), &'static str> {
2131                 // block for Rust 1.34 compat
2132                 let mut new_holder_commitment_tx = {
2133                         let trusted_tx = holder_commitment_tx.trust();
2134                         let txid = trusted_tx.txid();
2135                         let tx_keys = trusted_tx.keys();
2136                         self.current_holder_commitment_number = trusted_tx.commitment_number();
2137                         HolderSignedTx {
2138                                 txid,
2139                                 revocation_key: tx_keys.revocation_key,
2140                                 a_htlc_key: tx_keys.broadcaster_htlc_key,
2141                                 b_htlc_key: tx_keys.countersignatory_htlc_key,
2142                                 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
2143                                 per_commitment_point: tx_keys.per_commitment_point,
2144                                 htlc_outputs,
2145                                 to_self_value_sat: holder_commitment_tx.to_broadcaster_value_sat(),
2146                                 feerate_per_kw: trusted_tx.feerate_per_kw(),
2147                         }
2148                 };
2149                 self.onchain_tx_handler.provide_latest_holder_tx(holder_commitment_tx);
2150                 mem::swap(&mut new_holder_commitment_tx, &mut self.current_holder_commitment_tx);
2151                 self.prev_holder_signed_commitment_tx = Some(new_holder_commitment_tx);
2152                 if self.holder_tx_signed {
2153                         return Err("Latest holder commitment signed has already been signed, update is rejected");
2154                 }
2155                 Ok(())
2156         }
2157
2158         /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
2159         /// commitment_tx_infos which contain the payment hash have been revoked.
2160         fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(
2161                 &mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage, broadcaster: &B,
2162                 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L)
2163         where B::Target: BroadcasterInterface,
2164                     F::Target: FeeEstimator,
2165                     L::Target: Logger,
2166         {
2167                 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
2168
2169                 // If the channel is force closed, try to claim the output from this preimage.
2170                 // First check if a counterparty commitment transaction has been broadcasted:
2171                 macro_rules! claim_htlcs {
2172                         ($commitment_number: expr, $txid: expr) => {
2173                                 let (htlc_claim_reqs, _) = self.get_counterparty_output_claim_info($commitment_number, $txid, None);
2174                                 self.onchain_tx_handler.update_claims_view_from_requests(htlc_claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
2175                         }
2176                 }
2177                 if let Some(txid) = self.current_counterparty_commitment_txid {
2178                         if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
2179                                 claim_htlcs!(*commitment_number, txid);
2180                                 return;
2181                         }
2182                 }
2183                 if let Some(txid) = self.prev_counterparty_commitment_txid {
2184                         if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
2185                                 claim_htlcs!(*commitment_number, txid);
2186                                 return;
2187                         }
2188                 }
2189
2190                 // Then if a holder commitment transaction has been seen on-chain, broadcast transactions
2191                 // claiming the HTLC output from each of the holder commitment transactions.
2192                 // Note that we can't just use `self.holder_tx_signed`, because that only covers the case where
2193                 // *we* sign a holder commitment transaction, not when e.g. a watchtower broadcasts one of our
2194                 // holder commitment transactions.
2195                 if self.broadcasted_holder_revokable_script.is_some() {
2196                         // Assume that the broadcasted commitment transaction confirmed in the current best
2197                         // block. Even if not, its a reasonable metric for the bump criteria on the HTLC
2198                         // transactions.
2199                         let (claim_reqs, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
2200                         self.onchain_tx_handler.update_claims_view_from_requests(claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
2201                         if let Some(ref tx) = self.prev_holder_signed_commitment_tx {
2202                                 let (claim_reqs, _) = self.get_broadcasted_holder_claims(&tx, self.best_block.height());
2203                                 self.onchain_tx_handler.update_claims_view_from_requests(claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
2204                         }
2205                 }
2206         }
2207
2208         pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
2209                 where B::Target: BroadcasterInterface,
2210                                         L::Target: Logger,
2211         {
2212                 for tx in self.get_latest_holder_commitment_txn(logger).iter() {
2213                         log_info!(logger, "Broadcasting local {}", log_tx!(tx));
2214                         broadcaster.broadcast_transaction(tx);
2215                 }
2216                 self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
2217         }
2218
2219         pub fn update_monitor<B: Deref, F: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: F, logger: &L) -> Result<(), ()>
2220         where B::Target: BroadcasterInterface,
2221                 F::Target: FeeEstimator,
2222                 L::Target: Logger,
2223         {
2224                 log_info!(logger, "Applying update to monitor {}, bringing update_id from {} to {} with {} changes.",
2225                         log_funding_info!(self), self.latest_update_id, updates.update_id, updates.updates.len());
2226                 // ChannelMonitor updates may be applied after force close if we receive a
2227                 // preimage for a broadcasted commitment transaction HTLC output that we'd
2228                 // like to claim on-chain. If this is the case, we no longer have guaranteed
2229                 // access to the monitor's update ID, so we use a sentinel value instead.
2230                 if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
2231                         assert_eq!(updates.updates.len(), 1);
2232                         match updates.updates[0] {
2233                                 ChannelMonitorUpdateStep::PaymentPreimage { .. } => {},
2234                                 _ => {
2235                                         log_error!(logger, "Attempted to apply post-force-close ChannelMonitorUpdate of type {}", updates.updates[0].variant_name());
2236                                         panic!("Attempted to apply post-force-close ChannelMonitorUpdate that wasn't providing a payment preimage");
2237                                 },
2238                         }
2239                 } else if self.latest_update_id + 1 != updates.update_id {
2240                         panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
2241                 }
2242                 let mut ret = Ok(());
2243                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&*fee_estimator);
2244                 for update in updates.updates.iter() {
2245                         match update {
2246                                 ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs } => {
2247                                         log_trace!(logger, "Updating ChannelMonitor with latest holder commitment transaction info");
2248                                         if self.lockdown_from_offchain { panic!(); }
2249                                         if let Err(e) = self.provide_latest_holder_commitment_tx(commitment_tx.clone(), htlc_outputs.clone()) {
2250                                                 log_error!(logger, "Providing latest holder commitment transaction failed/was refused:");
2251                                                 log_error!(logger, "    {}", e);
2252                                                 ret = Err(());
2253                                         }
2254                                 }
2255                                 ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid, htlc_outputs, commitment_number, their_per_commitment_point } => {
2256                                         log_trace!(logger, "Updating ChannelMonitor with latest counterparty commitment transaction info");
2257                                         self.provide_latest_counterparty_commitment_tx(*commitment_txid, htlc_outputs.clone(), *commitment_number, *their_per_commitment_point, logger)
2258                                 },
2259                                 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } => {
2260                                         log_trace!(logger, "Updating ChannelMonitor with payment preimage");
2261                                         self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage, broadcaster, &bounded_fee_estimator, logger)
2262                                 },
2263                                 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } => {
2264                                         log_trace!(logger, "Updating ChannelMonitor with commitment secret");
2265                                         if let Err(e) = self.provide_secret(*idx, *secret) {
2266                                                 log_error!(logger, "Providing latest counterparty commitment secret failed/was refused:");
2267                                                 log_error!(logger, "    {}", e);
2268                                                 ret = Err(());
2269                                         }
2270                                 },
2271                                 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
2272                                         log_trace!(logger, "Updating ChannelMonitor: channel force closed, should broadcast: {}", should_broadcast);
2273                                         self.lockdown_from_offchain = true;
2274                                         if *should_broadcast {
2275                                                 // There's no need to broadcast our commitment transaction if we've seen one
2276                                                 // confirmed (even with 1 confirmation) as it'll be rejected as
2277                                                 // duplicate/conflicting.
2278                                                 let detected_funding_spend = self.funding_spend_confirmed.is_some() ||
2279                                                         self.onchain_events_awaiting_threshold_conf.iter().find(|event| match event.event {
2280                                                                 OnchainEvent::FundingSpendConfirmation { .. } => true,
2281                                                                 _ => false,
2282                                                         }).is_some();
2283                                                 if detected_funding_spend {
2284                                                         continue;
2285                                                 }
2286                                                 self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
2287                                                 // If the channel supports anchor outputs, we'll need to emit an external
2288                                                 // event to be consumed such that a child transaction is broadcast with a
2289                                                 // high enough feerate for the parent commitment transaction to confirm.
2290                                                 if self.onchain_tx_handler.opt_anchors() {
2291                                                         let funding_output = HolderFundingOutput::build(
2292                                                                 self.funding_redeemscript.clone(), self.channel_value_satoshis,
2293                                                                 self.onchain_tx_handler.opt_anchors(),
2294                                                         );
2295                                                         let best_block_height = self.best_block.height();
2296                                                         let commitment_package = PackageTemplate::build_package(
2297                                                                 self.funding_info.0.txid.clone(), self.funding_info.0.index as u32,
2298                                                                 PackageSolvingData::HolderFundingOutput(funding_output),
2299                                                                 best_block_height, false, best_block_height,
2300                                                         );
2301                                                         self.onchain_tx_handler.update_claims_view_from_requests(
2302                                                                 vec![commitment_package], best_block_height, best_block_height,
2303                                                                 broadcaster, &bounded_fee_estimator, logger,
2304                                                         );
2305                                                 }
2306                                         } else if !self.holder_tx_signed {
2307                                                 log_error!(logger, "WARNING: You have a potentially-unsafe holder commitment transaction available to broadcast");
2308                                                 log_error!(logger, "    in channel monitor for channel {}!", log_bytes!(self.funding_info.0.to_channel_id()));
2309                                                 log_error!(logger, "    Read the docs for ChannelMonitor::get_latest_holder_commitment_txn and take manual action!");
2310                                         } else {
2311                                                 // If we generated a MonitorEvent::CommitmentTxConfirmed, the ChannelManager
2312                                                 // will still give us a ChannelForceClosed event with !should_broadcast, but we
2313                                                 // shouldn't print the scary warning above.
2314                                                 log_info!(logger, "Channel off-chain state closed after we broadcasted our latest commitment transaction.");
2315                                         }
2316                                 },
2317                                 ChannelMonitorUpdateStep::ShutdownScript { scriptpubkey } => {
2318                                         log_trace!(logger, "Updating ChannelMonitor with shutdown script");
2319                                         if let Some(shutdown_script) = self.shutdown_script.replace(scriptpubkey.clone()) {
2320                                                 panic!("Attempted to replace shutdown script {} with {}", shutdown_script, scriptpubkey);
2321                                         }
2322                                 },
2323                         }
2324                 }
2325                 self.latest_update_id = updates.update_id;
2326
2327                 if ret.is_ok() && self.funding_spend_seen {
2328                         log_error!(logger, "Refusing Channel Monitor Update as counterparty attempted to update commitment after funding was spent");
2329                         Err(())
2330                 } else { ret }
2331         }
2332
2333         pub fn get_latest_update_id(&self) -> u64 {
2334                 self.latest_update_id
2335         }
2336
2337         pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
2338                 &self.funding_info
2339         }
2340
2341         pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<(u32, Script)>> {
2342                 // If we've detected a counterparty commitment tx on chain, we must include it in the set
2343                 // of outputs to watch for spends of, otherwise we're likely to lose user funds. Because
2344                 // its trivial to do, double-check that here.
2345                 for (txid, _) in self.counterparty_commitment_txn_on_chain.iter() {
2346                         self.outputs_to_watch.get(txid).expect("Counterparty commitment txn which have been broadcast should have outputs registered");
2347                 }
2348                 &self.outputs_to_watch
2349         }
2350
2351         pub fn get_and_clear_pending_monitor_events(&mut self) -> Vec<MonitorEvent> {
2352                 let mut ret = Vec::new();
2353                 mem::swap(&mut ret, &mut self.pending_monitor_events);
2354                 ret
2355         }
2356
2357         pub fn get_and_clear_pending_events(&mut self) -> Vec<Event> {
2358                 let mut ret = Vec::new();
2359                 mem::swap(&mut ret, &mut self.pending_events);
2360                 #[cfg(anchors)]
2361                 for claim_event in self.onchain_tx_handler.get_and_clear_pending_claim_events().drain(..) {
2362                         match claim_event {
2363                                 ClaimEvent::BumpCommitment {
2364                                         package_target_feerate_sat_per_1000_weight, commitment_tx, anchor_output_idx,
2365                                 } => {
2366                                         let commitment_txid = commitment_tx.txid();
2367                                         debug_assert_eq!(self.current_holder_commitment_tx.txid, commitment_txid);
2368                                         let pending_htlcs = self.current_holder_commitment_tx.non_dust_htlcs();
2369                                         let commitment_tx_fee_satoshis = self.channel_value_satoshis -
2370                                                 commitment_tx.output.iter().fold(0u64, |sum, output| sum + output.value);
2371                                         ret.push(Event::BumpTransaction(BumpTransactionEvent::ChannelClose {
2372                                                 package_target_feerate_sat_per_1000_weight,
2373                                                 commitment_tx,
2374                                                 commitment_tx_fee_satoshis,
2375                                                 anchor_descriptor: AnchorDescriptor {
2376                                                         channel_keys_id: self.channel_keys_id,
2377                                                         channel_value_satoshis: self.channel_value_satoshis,
2378                                                         outpoint: BitcoinOutPoint {
2379                                                                 txid: commitment_txid,
2380                                                                 vout: anchor_output_idx,
2381                                                         },
2382                                                 },
2383                                                 pending_htlcs,
2384                                         }));
2385                                 },
2386                                 ClaimEvent::BumpHTLC {
2387                                         target_feerate_sat_per_1000_weight, htlcs,
2388                                 } => {
2389                                         let mut htlc_descriptors = Vec::with_capacity(htlcs.len());
2390                                         for htlc in htlcs {
2391                                                 htlc_descriptors.push(HTLCDescriptor {
2392                                                         channel_keys_id: self.channel_keys_id,
2393                                                         channel_value_satoshis: self.channel_value_satoshis,
2394                                                         channel_parameters: self.onchain_tx_handler.channel_transaction_parameters.clone(),
2395                                                         commitment_txid: htlc.commitment_txid,
2396                                                         per_commitment_number: htlc.per_commitment_number,
2397                                                         htlc: htlc.htlc,
2398                                                         preimage: htlc.preimage,
2399                                                         counterparty_sig: htlc.counterparty_sig,
2400                                                 });
2401                                         }
2402                                         ret.push(Event::BumpTransaction(BumpTransactionEvent::HTLCResolution {
2403                                                 target_feerate_sat_per_1000_weight,
2404                                                 htlc_descriptors,
2405                                         }));
2406                                 }
2407                         }
2408                 }
2409                 ret
2410         }
2411
2412         /// Can only fail if idx is < get_min_seen_secret
2413         fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
2414                 self.commitment_secrets.get_secret(idx)
2415         }
2416
2417         pub(crate) fn get_min_seen_secret(&self) -> u64 {
2418                 self.commitment_secrets.get_min_seen_secret()
2419         }
2420
2421         pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
2422                 self.current_counterparty_commitment_number
2423         }
2424
2425         pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
2426                 self.current_holder_commitment_number
2427         }
2428
2429         /// Attempts to claim a counterparty commitment transaction's outputs using the revocation key and
2430         /// data in counterparty_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
2431         /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
2432         /// HTLC-Success/HTLC-Timeout transactions.
2433         ///
2434         /// Returns packages to claim the revoked output(s), as well as additional outputs to watch and
2435         /// general information about the output that is to the counterparty in the commitment
2436         /// transaction.
2437         fn check_spend_counterparty_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, block_hash: &BlockHash, logger: &L)
2438                 -> (Vec<PackageTemplate>, TransactionOutputs, CommitmentTxCounterpartyOutputInfo)
2439         where L::Target: Logger {
2440                 // Most secp and related errors trying to create keys means we have no hope of constructing
2441                 // a spend transaction...so we return no transactions to broadcast
2442                 let mut claimable_outpoints = Vec::new();
2443                 let mut watch_outputs = Vec::new();
2444                 let mut to_counterparty_output_info = None;
2445
2446                 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
2447                 let per_commitment_option = self.counterparty_claimable_outpoints.get(&commitment_txid);
2448
2449                 macro_rules! ignore_error {
2450                         ( $thing : expr ) => {
2451                                 match $thing {
2452                                         Ok(a) => a,
2453                                         Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs), to_counterparty_output_info)
2454                                 }
2455                         };
2456                 }
2457
2458                 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);
2459                 if commitment_number >= self.get_min_seen_secret() {
2460                         let secret = self.get_secret(commitment_number).unwrap();
2461                         let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
2462                         let per_commitment_point = PublicKey::from_secret_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_key);
2463                         let revocation_pubkey = chan_utils::derive_public_revocation_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint);
2464                         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);
2465
2466                         let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.counterparty_commitment_params.on_counterparty_tx_csv, &delayed_key);
2467                         let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
2468
2469                         // First, process non-htlc outputs (to_holder & to_counterparty)
2470                         for (idx, outp) in tx.output.iter().enumerate() {
2471                                 if outp.script_pubkey == revokeable_p2wsh {
2472                                         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);
2473                                         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);
2474                                         claimable_outpoints.push(justice_package);
2475                                         to_counterparty_output_info =
2476                                                 Some((idx.try_into().expect("Txn can't have more than 2^32 outputs"), outp.value));
2477                                 }
2478                         }
2479
2480                         // Then, try to find revoked htlc outputs
2481                         if let Some(ref per_commitment_data) = per_commitment_option {
2482                                 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
2483                                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2484                                                 if transaction_output_index as usize >= tx.output.len() ||
2485                                                                 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
2486                                                         // per_commitment_data is corrupt or our commitment signing key leaked!
2487                                                         return (claimable_outpoints, (commitment_txid, watch_outputs),
2488                                                                 to_counterparty_output_info);
2489                                                 }
2490                                                 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());
2491                                                 let justice_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, PackageSolvingData::RevokedHTLCOutput(revk_htlc_outp), htlc.cltv_expiry, true, height);
2492                                                 claimable_outpoints.push(justice_package);
2493                                         }
2494                                 }
2495                         }
2496
2497                         // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
2498                         if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
2499                                 // We're definitely a counterparty commitment transaction!
2500                                 log_error!(logger, "Got broadcast of revoked counterparty commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
2501                                 for (idx, outp) in tx.output.iter().enumerate() {
2502                                         watch_outputs.push((idx as u32, outp.clone()));
2503                                 }
2504                                 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
2505
2506                                 if let Some(per_commitment_data) = per_commitment_option {
2507                                         fail_unbroadcast_htlcs!(self, "revoked_counterparty", commitment_txid, tx, height,
2508                                                 block_hash, per_commitment_data.iter().map(|(htlc, htlc_source)|
2509                                                         (htlc, htlc_source.as_ref().map(|htlc_source| htlc_source.as_ref()))
2510                                                 ), logger);
2511                                 } else {
2512                                         debug_assert!(false, "We should have per-commitment option for any recognized old commitment txn");
2513                                         fail_unbroadcast_htlcs!(self, "revoked counterparty", commitment_txid, tx, height,
2514                                                 block_hash, [].iter().map(|reference| *reference), logger);
2515                                 }
2516                         }
2517                 } else if let Some(per_commitment_data) = per_commitment_option {
2518                         // While this isn't useful yet, there is a potential race where if a counterparty
2519                         // revokes a state at the same time as the commitment transaction for that state is
2520                         // confirmed, and the watchtower receives the block before the user, the user could
2521                         // upload a new ChannelMonitor with the revocation secret but the watchtower has
2522                         // already processed the block, resulting in the counterparty_commitment_txn_on_chain entry
2523                         // not being generated by the above conditional. Thus, to be safe, we go ahead and
2524                         // insert it here.
2525                         for (idx, outp) in tx.output.iter().enumerate() {
2526                                 watch_outputs.push((idx as u32, outp.clone()));
2527                         }
2528                         self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
2529
2530                         log_info!(logger, "Got broadcast of non-revoked counterparty commitment transaction {}", commitment_txid);
2531                         fail_unbroadcast_htlcs!(self, "counterparty", commitment_txid, tx, height, block_hash,
2532                                 per_commitment_data.iter().map(|(htlc, htlc_source)|
2533                                         (htlc, htlc_source.as_ref().map(|htlc_source| htlc_source.as_ref()))
2534                                 ), logger);
2535
2536                         let (htlc_claim_reqs, counterparty_output_info) =
2537                                 self.get_counterparty_output_claim_info(commitment_number, commitment_txid, Some(tx));
2538                         to_counterparty_output_info = counterparty_output_info;
2539                         for req in htlc_claim_reqs {
2540                                 claimable_outpoints.push(req);
2541                         }
2542
2543                 }
2544                 (claimable_outpoints, (commitment_txid, watch_outputs), to_counterparty_output_info)
2545         }
2546
2547         /// Returns the HTLC claim package templates and the counterparty output info
2548         fn get_counterparty_output_claim_info(&self, commitment_number: u64, commitment_txid: Txid, tx: Option<&Transaction>)
2549         -> (Vec<PackageTemplate>, CommitmentTxCounterpartyOutputInfo) {
2550                 let mut claimable_outpoints = Vec::new();
2551                 let mut to_counterparty_output_info: CommitmentTxCounterpartyOutputInfo = None;
2552
2553                 let htlc_outputs = match self.counterparty_claimable_outpoints.get(&commitment_txid) {
2554                         Some(outputs) => outputs,
2555                         None => return (claimable_outpoints, to_counterparty_output_info),
2556                 };
2557                 let per_commitment_points = match self.their_cur_per_commitment_points {
2558                         Some(points) => points,
2559                         None => return (claimable_outpoints, to_counterparty_output_info),
2560                 };
2561
2562                 let per_commitment_point =
2563                         // If the counterparty commitment tx is the latest valid state, use their latest
2564                         // per-commitment point
2565                         if per_commitment_points.0 == commitment_number { &per_commitment_points.1 }
2566                         else if let Some(point) = per_commitment_points.2.as_ref() {
2567                                 // If counterparty commitment tx is the state previous to the latest valid state, use
2568                                 // their previous per-commitment point (non-atomicity of revocation means it's valid for
2569                                 // them to temporarily have two valid commitment txns from our viewpoint)
2570                                 if per_commitment_points.0 == commitment_number + 1 {
2571                                         point
2572                                 } else { return (claimable_outpoints, to_counterparty_output_info); }
2573                         } else { return (claimable_outpoints, to_counterparty_output_info); };
2574
2575                 if let Some(transaction) = tx {
2576                         let revocation_pubkey = chan_utils::derive_public_revocation_key(
2577                                 &self.onchain_tx_handler.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint);
2578                         let delayed_key = chan_utils::derive_public_key(&self.onchain_tx_handler.secp_ctx,
2579                                 &per_commitment_point,
2580                                 &self.counterparty_commitment_params.counterparty_delayed_payment_base_key);
2581                         let revokeable_p2wsh = chan_utils::get_revokeable_redeemscript(&revocation_pubkey,
2582                                 self.counterparty_commitment_params.on_counterparty_tx_csv,
2583                                 &delayed_key).to_v0_p2wsh();
2584                         for (idx, outp) in transaction.output.iter().enumerate() {
2585                                 if outp.script_pubkey == revokeable_p2wsh {
2586                                         to_counterparty_output_info =
2587                                                 Some((idx.try_into().expect("Can't have > 2^32 outputs"), outp.value));
2588                                 }
2589                         }
2590                 }
2591
2592                 for (_, &(ref htlc, _)) in htlc_outputs.iter().enumerate() {
2593                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2594                                 if let Some(transaction) = tx {
2595                                         if transaction_output_index as usize >= transaction.output.len() ||
2596                                                 transaction.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
2597                                                         // per_commitment_data is corrupt or our commitment signing key leaked!
2598                                                         return (claimable_outpoints, to_counterparty_output_info);
2599                                                 }
2600                                 }
2601                                 let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
2602                                 if preimage.is_some() || !htlc.offered {
2603                                         let counterparty_htlc_outp = if htlc.offered {
2604                                                 PackageSolvingData::CounterpartyOfferedHTLCOutput(
2605                                                         CounterpartyOfferedHTLCOutput::build(*per_commitment_point,
2606                                                                 self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
2607                                                                 self.counterparty_commitment_params.counterparty_htlc_base_key,
2608                                                                 preimage.unwrap(), htlc.clone(), self.onchain_tx_handler.opt_anchors()))
2609                                         } else {
2610                                                 PackageSolvingData::CounterpartyReceivedHTLCOutput(
2611                                                         CounterpartyReceivedHTLCOutput::build(*per_commitment_point,
2612                                                                 self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
2613                                                                 self.counterparty_commitment_params.counterparty_htlc_base_key,
2614                                                                 htlc.clone(), self.onchain_tx_handler.opt_anchors()))
2615                                         };
2616                                         let aggregation = if !htlc.offered { false } else { true };
2617                                         let counterparty_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, counterparty_htlc_outp, htlc.cltv_expiry,aggregation, 0);
2618                                         claimable_outpoints.push(counterparty_package);
2619                                 }
2620                         }
2621                 }
2622
2623                 (claimable_outpoints, to_counterparty_output_info)
2624         }
2625
2626         /// Attempts to claim a counterparty HTLC-Success/HTLC-Timeout's outputs using the revocation key
2627         fn check_spend_counterparty_htlc<L: Deref>(
2628                 &mut self, tx: &Transaction, commitment_number: u64, commitment_txid: &Txid, height: u32, logger: &L
2629         ) -> (Vec<PackageTemplate>, Option<TransactionOutputs>) where L::Target: Logger {
2630                 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
2631                 let per_commitment_key = match SecretKey::from_slice(&secret) {
2632                         Ok(key) => key,
2633                         Err(_) => return (Vec::new(), None)
2634                 };
2635                 let per_commitment_point = PublicKey::from_secret_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_key);
2636
2637                 let htlc_txid = tx.txid();
2638                 let mut claimable_outpoints = vec![];
2639                 let mut outputs_to_watch = None;
2640                 // Previously, we would only claim HTLCs from revoked HTLC transactions if they had 1 input
2641                 // with a witness of 5 elements and 1 output. This wasn't enough for anchor outputs, as the
2642                 // counterparty can now aggregate multiple HTLCs into a single transaction thanks to
2643                 // `SIGHASH_SINGLE` remote signatures, leading us to not claim any HTLCs upon seeing a
2644                 // confirmed revoked HTLC transaction (for more details, see
2645                 // https://lists.linuxfoundation.org/pipermail/lightning-dev/2022-April/003561.html).
2646                 //
2647                 // We make sure we're not vulnerable to this case by checking all inputs of the transaction,
2648                 // and claim those which spend the commitment transaction, have a witness of 5 elements, and
2649                 // have a corresponding output at the same index within the transaction.
2650                 for (idx, input) in tx.input.iter().enumerate() {
2651                         if input.previous_output.txid == *commitment_txid && input.witness.len() == 5 && tx.output.get(idx).is_some() {
2652                                 log_error!(logger, "Got broadcast of revoked counterparty HTLC transaction, spending {}:{}", htlc_txid, idx);
2653                                 let revk_outp = RevokedOutput::build(
2654                                         per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
2655                                         self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key,
2656                                         tx.output[idx].value, self.counterparty_commitment_params.on_counterparty_tx_csv
2657                                 );
2658                                 let justice_package = PackageTemplate::build_package(
2659                                         htlc_txid, idx as u32, PackageSolvingData::RevokedOutput(revk_outp),
2660                                         height + self.counterparty_commitment_params.on_counterparty_tx_csv as u32, true, height
2661                                 );
2662                                 claimable_outpoints.push(justice_package);
2663                                 if outputs_to_watch.is_none() {
2664                                         outputs_to_watch = Some((htlc_txid, vec![]));
2665                                 }
2666                                 outputs_to_watch.as_mut().unwrap().1.push((idx as u32, tx.output[idx].clone()));
2667                         }
2668                 }
2669                 (claimable_outpoints, outputs_to_watch)
2670         }
2671
2672         // Returns (1) `PackageTemplate`s that can be given to the OnchainTxHandler, so that the handler can
2673         // broadcast transactions claiming holder HTLC commitment outputs and (2) a holder revokable
2674         // script so we can detect whether a holder transaction has been seen on-chain.
2675         fn get_broadcasted_holder_claims(&self, holder_tx: &HolderSignedTx, conf_height: u32) -> (Vec<PackageTemplate>, Option<(Script, PublicKey, PublicKey)>) {
2676                 let mut claim_requests = Vec::with_capacity(holder_tx.htlc_outputs.len());
2677
2678                 let redeemscript = chan_utils::get_revokeable_redeemscript(&holder_tx.revocation_key, self.on_holder_tx_csv, &holder_tx.delayed_payment_key);
2679                 let broadcasted_holder_revokable_script = Some((redeemscript.to_v0_p2wsh(), holder_tx.per_commitment_point.clone(), holder_tx.revocation_key.clone()));
2680
2681                 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
2682                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2683                                 let (htlc_output, aggregable) = if htlc.offered {
2684                                         let htlc_output = HolderHTLCOutput::build_offered(
2685                                                 htlc.amount_msat, htlc.cltv_expiry, self.onchain_tx_handler.opt_anchors()
2686                                         );
2687                                         (htlc_output, false)
2688                                 } else {
2689                                         let payment_preimage = if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
2690                                                 preimage.clone()
2691                                         } else {
2692                                                 // We can't build an HTLC-Success transaction without the preimage
2693                                                 continue;
2694                                         };
2695                                         let htlc_output = HolderHTLCOutput::build_accepted(
2696                                                 payment_preimage, htlc.amount_msat, self.onchain_tx_handler.opt_anchors()
2697                                         );
2698                                         (htlc_output, self.onchain_tx_handler.opt_anchors())
2699                                 };
2700                                 let htlc_package = PackageTemplate::build_package(
2701                                         holder_tx.txid, transaction_output_index,
2702                                         PackageSolvingData::HolderHTLCOutput(htlc_output),
2703                                         htlc.cltv_expiry, aggregable, conf_height
2704                                 );
2705                                 claim_requests.push(htlc_package);
2706                         }
2707                 }
2708
2709                 (claim_requests, broadcasted_holder_revokable_script)
2710         }
2711
2712         // Returns holder HTLC outputs to watch and react to in case of spending.
2713         fn get_broadcasted_holder_watch_outputs(&self, holder_tx: &HolderSignedTx, commitment_tx: &Transaction) -> Vec<(u32, TxOut)> {
2714                 let mut watch_outputs = Vec::with_capacity(holder_tx.htlc_outputs.len());
2715                 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
2716                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2717                                 watch_outputs.push((transaction_output_index, commitment_tx.output[transaction_output_index as usize].clone()));
2718                         }
2719                 }
2720                 watch_outputs
2721         }
2722
2723         /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
2724         /// revoked using data in holder_claimable_outpoints.
2725         /// Should not be used if check_spend_revoked_transaction succeeds.
2726         /// Returns None unless the transaction is definitely one of our commitment transactions.
2727         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 {
2728                 let commitment_txid = tx.txid();
2729                 let mut claim_requests = Vec::new();
2730                 let mut watch_outputs = Vec::new();
2731
2732                 macro_rules! append_onchain_update {
2733                         ($updates: expr, $to_watch: expr) => {
2734                                 claim_requests = $updates.0;
2735                                 self.broadcasted_holder_revokable_script = $updates.1;
2736                                 watch_outputs.append(&mut $to_watch);
2737                         }
2738                 }
2739
2740                 // HTLCs set may differ between last and previous holder commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
2741                 let mut is_holder_tx = false;
2742
2743                 if self.current_holder_commitment_tx.txid == commitment_txid {
2744                         is_holder_tx = true;
2745                         log_info!(logger, "Got broadcast of latest holder commitment tx {}, searching for available HTLCs to claim", commitment_txid);
2746                         let res = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, height);
2747                         let mut to_watch = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, tx);
2748                         append_onchain_update!(res, to_watch);
2749                         fail_unbroadcast_htlcs!(self, "latest holder", commitment_txid, tx, height,
2750                                 block_hash, self.current_holder_commitment_tx.htlc_outputs.iter()
2751                                 .map(|(htlc, _, htlc_source)| (htlc, htlc_source.as_ref())), logger);
2752                 } else if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
2753                         if holder_tx.txid == commitment_txid {
2754                                 is_holder_tx = true;
2755                                 log_info!(logger, "Got broadcast of previous holder commitment tx {}, searching for available HTLCs to claim", commitment_txid);
2756                                 let res = self.get_broadcasted_holder_claims(holder_tx, height);
2757                                 let mut to_watch = self.get_broadcasted_holder_watch_outputs(holder_tx, tx);
2758                                 append_onchain_update!(res, to_watch);
2759                                 fail_unbroadcast_htlcs!(self, "previous holder", commitment_txid, tx, height, block_hash,
2760                                         holder_tx.htlc_outputs.iter().map(|(htlc, _, htlc_source)| (htlc, htlc_source.as_ref())),
2761                                         logger);
2762                         }
2763                 }
2764
2765                 if is_holder_tx {
2766                         Some((claim_requests, (commitment_txid, watch_outputs)))
2767                 } else {
2768                         None
2769                 }
2770         }
2771
2772         pub fn get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
2773                 log_debug!(logger, "Getting signed latest holder commitment transaction!");
2774                 self.holder_tx_signed = true;
2775                 let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
2776                 let txid = commitment_tx.txid();
2777                 let mut holder_transactions = vec![commitment_tx];
2778                 // When anchor outputs are present, the HTLC transactions are only valid once the commitment
2779                 // transaction confirms.
2780                 if self.onchain_tx_handler.opt_anchors() {
2781                         return holder_transactions;
2782                 }
2783                 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
2784                         if let Some(vout) = htlc.0.transaction_output_index {
2785                                 let preimage = if !htlc.0.offered {
2786                                         if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
2787                                                 // We can't build an HTLC-Success transaction without the preimage
2788                                                 continue;
2789                                         }
2790                                 } else if htlc.0.cltv_expiry > self.best_block.height() + 1 {
2791                                         // Don't broadcast HTLC-Timeout transactions immediately as they don't meet the
2792                                         // current locktime requirements on-chain. We will broadcast them in
2793                                         // `block_confirmed` when `should_broadcast_holder_commitment_txn` returns true.
2794                                         // Note that we add + 1 as transactions are broadcastable when they can be
2795                                         // confirmed in the next block.
2796                                         continue;
2797                                 } else { None };
2798                                 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
2799                                         &::bitcoin::OutPoint { txid, vout }, &preimage) {
2800                                         holder_transactions.push(htlc_tx);
2801                                 }
2802                         }
2803                 }
2804                 // 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.
2805                 // The data will be re-generated and tracked in check_spend_holder_transaction if we get a confirmation.
2806                 holder_transactions
2807         }
2808
2809         #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
2810         /// Note that this includes possibly-locktimed-in-the-future transactions!
2811         fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
2812                 log_debug!(logger, "Getting signed copy of latest holder commitment transaction!");
2813                 let commitment_tx = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript);
2814                 let txid = commitment_tx.txid();
2815                 let mut holder_transactions = vec![commitment_tx];
2816                 // When anchor outputs are present, the HTLC transactions are only final once the commitment
2817                 // transaction confirms due to the CSV 1 encumberance.
2818                 if self.onchain_tx_handler.opt_anchors() {
2819                         return holder_transactions;
2820                 }
2821                 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
2822                         if let Some(vout) = htlc.0.transaction_output_index {
2823                                 let preimage = if !htlc.0.offered {
2824                                         if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
2825                                                 // We can't build an HTLC-Success transaction without the preimage
2826                                                 continue;
2827                                         }
2828                                 } else { None };
2829                                 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
2830                                         &::bitcoin::OutPoint { txid, vout }, &preimage) {
2831                                         holder_transactions.push(htlc_tx);
2832                                 }
2833                         }
2834                 }
2835                 holder_transactions
2836         }
2837
2838         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>
2839                 where B::Target: BroadcasterInterface,
2840                       F::Target: FeeEstimator,
2841                                         L::Target: Logger,
2842         {
2843                 let block_hash = header.block_hash();
2844                 self.best_block = BestBlock::new(block_hash, height);
2845
2846                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
2847                 self.transactions_confirmed(header, txdata, height, broadcaster, &bounded_fee_estimator, logger)
2848         }
2849
2850         fn best_block_updated<B: Deref, F: Deref, L: Deref>(
2851                 &mut self,
2852                 header: &BlockHeader,
2853                 height: u32,
2854                 broadcaster: B,
2855                 fee_estimator: &LowerBoundedFeeEstimator<F>,
2856                 logger: L,
2857         ) -> Vec<TransactionOutputs>
2858         where
2859                 B::Target: BroadcasterInterface,
2860                 F::Target: FeeEstimator,
2861                 L::Target: Logger,
2862         {
2863                 let block_hash = header.block_hash();
2864
2865                 if height > self.best_block.height() {
2866                         self.best_block = BestBlock::new(block_hash, height);
2867                         self.block_confirmed(height, block_hash, vec![], vec![], vec![], &broadcaster, &fee_estimator, &logger)
2868                 } else if block_hash != self.best_block.block_hash() {
2869                         self.best_block = BestBlock::new(block_hash, height);
2870                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height <= height);
2871                         self.onchain_tx_handler.block_disconnected(height + 1, broadcaster, fee_estimator, logger);
2872                         Vec::new()
2873                 } else { Vec::new() }
2874         }
2875
2876         fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
2877                 &mut self,
2878                 header: &BlockHeader,
2879                 txdata: &TransactionData,
2880                 height: u32,
2881                 broadcaster: B,
2882                 fee_estimator: &LowerBoundedFeeEstimator<F>,
2883                 logger: L,
2884         ) -> Vec<TransactionOutputs>
2885         where
2886                 B::Target: BroadcasterInterface,
2887                 F::Target: FeeEstimator,
2888                 L::Target: Logger,
2889         {
2890                 let txn_matched = self.filter_block(txdata);
2891                 for tx in &txn_matched {
2892                         let mut output_val = 0;
2893                         for out in tx.output.iter() {
2894                                 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
2895                                 output_val += out.value;
2896                                 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
2897                         }
2898                 }
2899
2900                 let block_hash = header.block_hash();
2901
2902                 let mut watch_outputs = Vec::new();
2903                 let mut claimable_outpoints = Vec::new();
2904                 'tx_iter: for tx in &txn_matched {
2905                         let txid = tx.txid();
2906                         // If a transaction has already been confirmed, ensure we don't bother processing it duplicatively.
2907                         if Some(txid) == self.funding_spend_confirmed {
2908                                 log_debug!(logger, "Skipping redundant processing of funding-spend tx {} as it was previously confirmed", txid);
2909                                 continue 'tx_iter;
2910                         }
2911                         for ev in self.onchain_events_awaiting_threshold_conf.iter() {
2912                                 if ev.txid == txid {
2913                                         if let Some(conf_hash) = ev.block_hash {
2914                                                 assert_eq!(header.block_hash(), conf_hash,
2915                                                         "Transaction {} was already confirmed and is being re-confirmed in a different block.\n\
2916                                                         This indicates a severe bug in the transaction connection logic - a reorg should have been processed first!", ev.txid);
2917                                         }
2918                                         log_debug!(logger, "Skipping redundant processing of confirming tx {} as it was previously confirmed", txid);
2919                                         continue 'tx_iter;
2920                                 }
2921                         }
2922                         for htlc in self.htlcs_resolved_on_chain.iter() {
2923                                 if Some(txid) == htlc.resolving_txid {
2924                                         log_debug!(logger, "Skipping redundant processing of HTLC resolution tx {} as it was previously confirmed", txid);
2925                                         continue 'tx_iter;
2926                                 }
2927                         }
2928                         for spendable_txid in self.spendable_txids_confirmed.iter() {
2929                                 if txid == *spendable_txid {
2930                                         log_debug!(logger, "Skipping redundant processing of spendable tx {} as it was previously confirmed", txid);
2931                                         continue 'tx_iter;
2932                                 }
2933                         }
2934
2935                         if tx.input.len() == 1 {
2936                                 // Assuming our keys were not leaked (in which case we're screwed no matter what),
2937                                 // commitment transactions and HTLC transactions will all only ever have one input
2938                                 // (except for HTLC transactions for channels with anchor outputs), which is an easy
2939                                 // way to filter out any potential non-matching txn for lazy filters.
2940                                 let prevout = &tx.input[0].previous_output;
2941                                 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
2942                                         let mut balance_spendable_csv = None;
2943                                         log_info!(logger, "Channel {} closed by funding output spend in txid {}.",
2944                                                 log_bytes!(self.funding_info.0.to_channel_id()), txid);
2945                                         self.funding_spend_seen = true;
2946                                         let mut commitment_tx_to_counterparty_output = None;
2947                                         if (tx.input[0].sequence.0 >> 8*3) as u8 == 0x80 && (tx.lock_time.0 >> 8*3) as u8 == 0x20 {
2948                                                 let (mut new_outpoints, new_outputs, counterparty_output_idx_sats) =
2949                                                         self.check_spend_counterparty_transaction(&tx, height, &block_hash, &logger);
2950                                                 commitment_tx_to_counterparty_output = counterparty_output_idx_sats;
2951                                                 if !new_outputs.1.is_empty() {
2952                                                         watch_outputs.push(new_outputs);
2953                                                 }
2954                                                 claimable_outpoints.append(&mut new_outpoints);
2955                                                 if new_outpoints.is_empty() {
2956                                                         if let Some((mut new_outpoints, new_outputs)) = self.check_spend_holder_transaction(&tx, height, &block_hash, &logger) {
2957                                                                 debug_assert!(commitment_tx_to_counterparty_output.is_none(),
2958                                                                         "A commitment transaction matched as both a counterparty and local commitment tx?");
2959                                                                 if !new_outputs.1.is_empty() {
2960                                                                         watch_outputs.push(new_outputs);
2961                                                                 }
2962                                                                 claimable_outpoints.append(&mut new_outpoints);
2963                                                                 balance_spendable_csv = Some(self.on_holder_tx_csv);
2964                                                         }
2965                                                 }
2966                                         }
2967                                         self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
2968                                                 txid,
2969                                                 transaction: Some((*tx).clone()),
2970                                                 height,
2971                                                 block_hash: Some(block_hash),
2972                                                 event: OnchainEvent::FundingSpendConfirmation {
2973                                                         on_local_output_csv: balance_spendable_csv,
2974                                                         commitment_tx_to_counterparty_output,
2975                                                 },
2976                                         });
2977                                 }
2978                         }
2979                         if tx.input.len() >= 1 {
2980                                 // While all commitment transactions have one input, HTLC transactions may have more
2981                                 // if the HTLC was present in an anchor channel. HTLCs can also be resolved in a few
2982                                 // other ways which can have more than one output.
2983                                 for tx_input in &tx.input {
2984                                         let commitment_txid = tx_input.previous_output.txid;
2985                                         if let Some(&commitment_number) = self.counterparty_commitment_txn_on_chain.get(&commitment_txid) {
2986                                                 let (mut new_outpoints, new_outputs_option) = self.check_spend_counterparty_htlc(
2987                                                         &tx, commitment_number, &commitment_txid, height, &logger
2988                                                 );
2989                                                 claimable_outpoints.append(&mut new_outpoints);
2990                                                 if let Some(new_outputs) = new_outputs_option {
2991                                                         watch_outputs.push(new_outputs);
2992                                                 }
2993                                                 // Since there may be multiple HTLCs for this channel (all spending the
2994                                                 // same commitment tx) being claimed by the counterparty within the same
2995                                                 // transaction, and `check_spend_counterparty_htlc` already checks all the
2996                                                 // ones relevant to this channel, we can safely break from our loop.
2997                                                 break;
2998                                         }
2999                                 }
3000                                 self.is_resolving_htlc_output(&tx, height, &block_hash, &logger);
3001
3002                                 self.is_paying_spendable_output(&tx, height, &block_hash, &logger);
3003                         }
3004                 }
3005
3006                 if height > self.best_block.height() {
3007                         self.best_block = BestBlock::new(block_hash, height);
3008                 }
3009
3010                 self.block_confirmed(height, block_hash, txn_matched, watch_outputs, claimable_outpoints, &broadcaster, &fee_estimator, &logger)
3011         }
3012
3013         /// Update state for new block(s)/transaction(s) confirmed. Note that the caller must update
3014         /// `self.best_block` before calling if a new best blockchain tip is available. More
3015         /// concretely, `self.best_block` must never be at a lower height than `conf_height`, avoiding
3016         /// complexity especially in
3017         /// `OnchainTx::update_claims_view_from_requests`/`OnchainTx::update_claims_view_from_matched_txn`.
3018         ///
3019         /// `conf_height` should be set to the height at which any new transaction(s)/block(s) were
3020         /// confirmed at, even if it is not the current best height.
3021         fn block_confirmed<B: Deref, F: Deref, L: Deref>(
3022                 &mut self,
3023                 conf_height: u32,
3024                 conf_hash: BlockHash,
3025                 txn_matched: Vec<&Transaction>,
3026                 mut watch_outputs: Vec<TransactionOutputs>,
3027                 mut claimable_outpoints: Vec<PackageTemplate>,
3028                 broadcaster: &B,
3029                 fee_estimator: &LowerBoundedFeeEstimator<F>,
3030                 logger: &L,
3031         ) -> Vec<TransactionOutputs>
3032         where
3033                 B::Target: BroadcasterInterface,
3034                 F::Target: FeeEstimator,
3035                 L::Target: Logger,
3036         {
3037                 log_trace!(logger, "Processing {} matched transactions for block at height {}.", txn_matched.len(), conf_height);
3038                 debug_assert!(self.best_block.height() >= conf_height);
3039
3040                 let should_broadcast = self.should_broadcast_holder_commitment_txn(logger);
3041                 if should_broadcast {
3042                         let funding_outp = HolderFundingOutput::build(self.funding_redeemscript.clone(), self.channel_value_satoshis, self.onchain_tx_handler.opt_anchors());
3043                         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());
3044                         claimable_outpoints.push(commitment_package);
3045                         self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
3046                         let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
3047                         self.holder_tx_signed = true;
3048                         // We can't broadcast our HTLC transactions while the commitment transaction is
3049                         // unconfirmed. We'll delay doing so until we detect the confirmed commitment in
3050                         // `transactions_confirmed`.
3051                         if !self.onchain_tx_handler.opt_anchors() {
3052                                 // Because we're broadcasting a commitment transaction, we should construct the package
3053                                 // assuming it gets confirmed in the next block. Sadly, we have code which considers
3054                                 // "not yet confirmed" things as discardable, so we cannot do that here.
3055                                 let (mut new_outpoints, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
3056                                 let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &commitment_tx);
3057                                 if !new_outputs.is_empty() {
3058                                         watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
3059                                 }
3060                                 claimable_outpoints.append(&mut new_outpoints);
3061                         }
3062                 }
3063
3064                 // Find which on-chain events have reached their confirmation threshold.
3065                 let onchain_events_awaiting_threshold_conf =
3066                         self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
3067                 let mut onchain_events_reaching_threshold_conf = Vec::new();
3068                 for entry in onchain_events_awaiting_threshold_conf {
3069                         if entry.has_reached_confirmation_threshold(&self.best_block) {
3070                                 onchain_events_reaching_threshold_conf.push(entry);
3071                         } else {
3072                                 self.onchain_events_awaiting_threshold_conf.push(entry);
3073                         }
3074                 }
3075
3076                 // Used to check for duplicate HTLC resolutions.
3077                 #[cfg(debug_assertions)]
3078                 let unmatured_htlcs: Vec<_> = self.onchain_events_awaiting_threshold_conf
3079                         .iter()
3080                         .filter_map(|entry| match &entry.event {
3081                                 OnchainEvent::HTLCUpdate { source, .. } => Some(source),
3082                                 _ => None,
3083                         })
3084                         .collect();
3085                 #[cfg(debug_assertions)]
3086                 let mut matured_htlcs = Vec::new();
3087
3088                 // Produce actionable events from on-chain events having reached their threshold.
3089                 for entry in onchain_events_reaching_threshold_conf.drain(..) {
3090                         match entry.event {
3091                                 OnchainEvent::HTLCUpdate { ref source, payment_hash, htlc_value_satoshis, commitment_tx_output_idx } => {
3092                                         // Check for duplicate HTLC resolutions.
3093                                         #[cfg(debug_assertions)]
3094                                         {
3095                                                 debug_assert!(
3096                                                         unmatured_htlcs.iter().find(|&htlc| htlc == &source).is_none(),
3097                                                         "An unmature HTLC transaction conflicts with a maturing one; failed to \
3098                                                          call either transaction_unconfirmed for the conflicting transaction \
3099                                                          or block_disconnected for a block containing it.");
3100                                                 debug_assert!(
3101                                                         matured_htlcs.iter().find(|&htlc| htlc == source).is_none(),
3102                                                         "A matured HTLC transaction conflicts with a maturing one; failed to \
3103                                                          call either transaction_unconfirmed for the conflicting transaction \
3104                                                          or block_disconnected for a block containing it.");
3105                                                 matured_htlcs.push(source.clone());
3106                                         }
3107
3108                                         log_debug!(logger, "HTLC {} failure update in {} has got enough confirmations to be passed upstream",
3109                                                 log_bytes!(payment_hash.0), entry.txid);
3110                                         self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
3111                                                 payment_hash,
3112                                                 payment_preimage: None,
3113                                                 source: source.clone(),
3114                                                 htlc_value_satoshis,
3115                                         }));
3116                                         self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC {
3117                                                 commitment_tx_output_idx,
3118                                                 resolving_txid: Some(entry.txid),
3119                                                 resolving_tx: entry.transaction,
3120                                                 payment_preimage: None,
3121                                         });
3122                                 },
3123                                 OnchainEvent::MaturingOutput { descriptor } => {
3124                                         log_debug!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
3125                                         self.pending_events.push(Event::SpendableOutputs {
3126                                                 outputs: vec![descriptor]
3127                                         });
3128                                         self.spendable_txids_confirmed.push(entry.txid);
3129                                 },
3130                                 OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, preimage, .. } => {
3131                                         self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC {
3132                                                 commitment_tx_output_idx: Some(commitment_tx_output_idx),
3133                                                 resolving_txid: Some(entry.txid),
3134                                                 resolving_tx: entry.transaction,
3135                                                 payment_preimage: preimage,
3136                                         });
3137                                 },
3138                                 OnchainEvent::FundingSpendConfirmation { commitment_tx_to_counterparty_output, .. } => {
3139                                         self.funding_spend_confirmed = Some(entry.txid);
3140                                         self.confirmed_commitment_tx_counterparty_output = commitment_tx_to_counterparty_output;
3141                                 },
3142                         }
3143                 }
3144
3145                 self.onchain_tx_handler.update_claims_view_from_requests(claimable_outpoints, conf_height, self.best_block.height(), broadcaster, fee_estimator, logger);
3146                 self.onchain_tx_handler.update_claims_view_from_matched_txn(&txn_matched, conf_height, conf_hash, self.best_block.height(), broadcaster, fee_estimator, logger);
3147
3148                 // Determine new outputs to watch by comparing against previously known outputs to watch,
3149                 // updating the latter in the process.
3150                 watch_outputs.retain(|&(ref txid, ref txouts)| {
3151                         let idx_and_scripts = txouts.iter().map(|o| (o.0, o.1.script_pubkey.clone())).collect();
3152                         self.outputs_to_watch.insert(txid.clone(), idx_and_scripts).is_none()
3153                 });
3154                 #[cfg(test)]
3155                 {
3156                         // If we see a transaction for which we registered outputs previously,
3157                         // make sure the registered scriptpubkey at the expected index match
3158                         // the actual transaction output one. We failed this case before #653.
3159                         for tx in &txn_matched {
3160                                 if let Some(outputs) = self.get_outputs_to_watch().get(&tx.txid()) {
3161                                         for idx_and_script in outputs.iter() {
3162                                                 assert!((idx_and_script.0 as usize) < tx.output.len());
3163                                                 assert_eq!(tx.output[idx_and_script.0 as usize].script_pubkey, idx_and_script.1);
3164                                         }
3165                                 }
3166                         }
3167                 }
3168                 watch_outputs
3169         }
3170
3171         pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, height: u32, broadcaster: B, fee_estimator: F, logger: L)
3172                 where B::Target: BroadcasterInterface,
3173                       F::Target: FeeEstimator,
3174                       L::Target: Logger,
3175         {
3176                 log_trace!(logger, "Block {} at height {} disconnected", header.block_hash(), height);
3177
3178                 //We may discard:
3179                 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
3180                 //- maturing spendable output has transaction paying us has been disconnected
3181                 self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height < height);
3182
3183                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
3184                 self.onchain_tx_handler.block_disconnected(height, broadcaster, &bounded_fee_estimator, logger);
3185
3186                 self.best_block = BestBlock::new(header.prev_blockhash, height - 1);
3187         }
3188
3189         fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
3190                 &mut self,
3191                 txid: &Txid,
3192                 broadcaster: B,
3193                 fee_estimator: &LowerBoundedFeeEstimator<F>,
3194                 logger: L,
3195         ) where
3196                 B::Target: BroadcasterInterface,
3197                 F::Target: FeeEstimator,
3198                 L::Target: Logger,
3199         {
3200                 let mut removed_height = None;
3201                 for entry in self.onchain_events_awaiting_threshold_conf.iter() {
3202                         if entry.txid == *txid {
3203                                 removed_height = Some(entry.height);
3204                                 break;
3205                         }
3206                 }
3207
3208                 if let Some(removed_height) = removed_height {
3209                         log_info!(logger, "transaction_unconfirmed of txid {} implies height {} was reorg'd out", txid, removed_height);
3210                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| if entry.height >= removed_height {
3211                                 log_info!(logger, "Transaction {} reorg'd out", entry.txid);
3212                                 false
3213                         } else { true });
3214                 }
3215
3216                 debug_assert!(!self.onchain_events_awaiting_threshold_conf.iter().any(|ref entry| entry.txid == *txid));
3217
3218                 self.onchain_tx_handler.transaction_unconfirmed(txid, broadcaster, fee_estimator, logger);
3219         }
3220
3221         /// Filters a block's `txdata` for transactions spending watched outputs or for any child
3222         /// transactions thereof.
3223         fn filter_block<'a>(&self, txdata: &TransactionData<'a>) -> Vec<&'a Transaction> {
3224                 let mut matched_txn = HashSet::new();
3225                 txdata.iter().filter(|&&(_, tx)| {
3226                         let mut matches = self.spends_watched_output(tx);
3227                         for input in tx.input.iter() {
3228                                 if matches { break; }
3229                                 if matched_txn.contains(&input.previous_output.txid) {
3230                                         matches = true;
3231                                 }
3232                         }
3233                         if matches {
3234                                 matched_txn.insert(tx.txid());
3235                         }
3236                         matches
3237                 }).map(|(_, tx)| *tx).collect()
3238         }
3239
3240         /// Checks if a given transaction spends any watched outputs.
3241         fn spends_watched_output(&self, tx: &Transaction) -> bool {
3242                 for input in tx.input.iter() {
3243                         if let Some(outputs) = self.get_outputs_to_watch().get(&input.previous_output.txid) {
3244                                 for (idx, _script_pubkey) in outputs.iter() {
3245                                         if *idx == input.previous_output.vout {
3246                                                 #[cfg(test)]
3247                                                 {
3248                                                         // If the expected script is a known type, check that the witness
3249                                                         // appears to be spending the correct type (ie that the match would
3250                                                         // actually succeed in BIP 158/159-style filters).
3251                                                         if _script_pubkey.is_v0_p2wsh() {
3252                                                                 if input.witness.last().unwrap().to_vec() == deliberately_bogus_accepted_htlc_witness_program() {
3253                                                                         // In at least one test we use a deliberately bogus witness
3254                                                                         // script which hit an old panic. Thus, we check for that here
3255                                                                         // and avoid the assert if its the expected bogus script.
3256                                                                         return true;
3257                                                                 }
3258
3259                                                                 assert_eq!(&bitcoin::Address::p2wsh(&Script::from(input.witness.last().unwrap().to_vec()), bitcoin::Network::Bitcoin).script_pubkey(), _script_pubkey);
3260                                                         } else if _script_pubkey.is_v0_p2wpkh() {
3261                                                                 assert_eq!(&bitcoin::Address::p2wpkh(&bitcoin::PublicKey::from_slice(&input.witness.last().unwrap()).unwrap(), bitcoin::Network::Bitcoin).unwrap().script_pubkey(), _script_pubkey);
3262                                                         } else { panic!(); }
3263                                                 }
3264                                                 return true;
3265                                         }
3266                                 }
3267                         }
3268                 }
3269
3270                 false
3271         }
3272
3273         fn should_broadcast_holder_commitment_txn<L: Deref>(&self, logger: &L) -> bool where L::Target: Logger {
3274                 // There's no need to broadcast our commitment transaction if we've seen one confirmed (even
3275                 // with 1 confirmation) as it'll be rejected as duplicate/conflicting.
3276                 if self.funding_spend_confirmed.is_some() ||
3277                         self.onchain_events_awaiting_threshold_conf.iter().find(|event| match event.event {
3278                                 OnchainEvent::FundingSpendConfirmation { .. } => true,
3279                                 _ => false,
3280                         }).is_some()
3281                 {
3282                         return false;
3283                 }
3284                 // We need to consider all HTLCs which are:
3285                 //  * in any unrevoked counterparty commitment transaction, as they could broadcast said
3286                 //    transactions and we'd end up in a race, or
3287                 //  * are in our latest holder commitment transaction, as this is the thing we will
3288                 //    broadcast if we go on-chain.
3289                 // Note that we consider HTLCs which were below dust threshold here - while they don't
3290                 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
3291                 // to the source, and if we don't fail the channel we will have to ensure that the next
3292                 // updates that peer sends us are update_fails, failing the channel if not. It's probably
3293                 // easier to just fail the channel as this case should be rare enough anyway.
3294                 let height = self.best_block.height();
3295                 macro_rules! scan_commitment {
3296                         ($htlcs: expr, $holder_tx: expr) => {
3297                                 for ref htlc in $htlcs {
3298                                         // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
3299                                         // chain with enough room to claim the HTLC without our counterparty being able to
3300                                         // time out the HTLC first.
3301                                         // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
3302                                         // concern is being able to claim the corresponding inbound HTLC (on another
3303                                         // channel) before it expires. In fact, we don't even really care if our
3304                                         // counterparty here claims such an outbound HTLC after it expired as long as we
3305                                         // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
3306                                         // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
3307                                         // we give ourselves a few blocks of headroom after expiration before going
3308                                         // on-chain for an expired HTLC.
3309                                         // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
3310                                         // from us until we've reached the point where we go on-chain with the
3311                                         // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
3312                                         // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
3313                                         //  aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
3314                                         //      inbound_cltv == height + CLTV_CLAIM_BUFFER
3315                                         //      outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
3316                                         //      LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
3317                                         //      CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
3318                                         //      LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
3319                                         //  The final, above, condition is checked for statically in channelmanager
3320                                         //  with CHECK_CLTV_EXPIRY_SANITY_2.
3321                                         let htlc_outbound = $holder_tx == htlc.offered;
3322                                         if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
3323                                            (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
3324                                                 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
3325                                                 return true;
3326                                         }
3327                                 }
3328                         }
3329                 }
3330
3331                 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
3332
3333                 if let Some(ref txid) = self.current_counterparty_commitment_txid {
3334                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
3335                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
3336                         }
3337                 }
3338                 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
3339                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
3340                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
3341                         }
3342                 }
3343
3344                 false
3345         }
3346
3347         /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a holder
3348         /// or counterparty commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
3349         fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, block_hash: &BlockHash, logger: &L) where L::Target: Logger {
3350                 'outer_loop: for input in &tx.input {
3351                         let mut payment_data = None;
3352                         let htlc_claim = HTLCClaim::from_witness(&input.witness);
3353                         let revocation_sig_claim = htlc_claim == Some(HTLCClaim::Revocation);
3354                         let accepted_preimage_claim = htlc_claim == Some(HTLCClaim::AcceptedPreimage);
3355                         #[cfg(not(fuzzing))]
3356                         let accepted_timeout_claim = htlc_claim == Some(HTLCClaim::AcceptedTimeout);
3357                         let offered_preimage_claim = htlc_claim == Some(HTLCClaim::OfferedPreimage);
3358                         #[cfg(not(fuzzing))]
3359                         let offered_timeout_claim = htlc_claim == Some(HTLCClaim::OfferedTimeout);
3360
3361                         let mut payment_preimage = PaymentPreimage([0; 32]);
3362                         if offered_preimage_claim || accepted_preimage_claim {
3363                                 payment_preimage.0.copy_from_slice(input.witness.second_to_last().unwrap());
3364                         }
3365
3366                         macro_rules! log_claim {
3367                                 ($tx_info: expr, $holder_tx: expr, $htlc: expr, $source_avail: expr) => {
3368                                         let outbound_htlc = $holder_tx == $htlc.offered;
3369                                         // HTLCs must either be claimed by a matching script type or through the
3370                                         // revocation path:
3371                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
3372                                         debug_assert!(!$htlc.offered || offered_preimage_claim || offered_timeout_claim || revocation_sig_claim);
3373                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
3374                                         debug_assert!($htlc.offered || accepted_preimage_claim || accepted_timeout_claim || revocation_sig_claim);
3375                                         // Further, only exactly one of the possible spend paths should have been
3376                                         // matched by any HTLC spend:
3377                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
3378                                         debug_assert_eq!(accepted_preimage_claim as u8 + accepted_timeout_claim as u8 +
3379                                                          offered_preimage_claim as u8 + offered_timeout_claim as u8 +
3380                                                          revocation_sig_claim as u8, 1);
3381                                         if ($holder_tx && revocation_sig_claim) ||
3382                                                         (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
3383                                                 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
3384                                                         $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
3385                                                         if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
3386                                                         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" });
3387                                         } else {
3388                                                 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
3389                                                         $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
3390                                                         if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
3391                                                         if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
3392                                         }
3393                                 }
3394                         }
3395
3396                         macro_rules! check_htlc_valid_counterparty {
3397                                 ($counterparty_txid: expr, $htlc_output: expr) => {
3398                                         if let Some(txid) = $counterparty_txid {
3399                                                 for &(ref pending_htlc, ref pending_source) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
3400                                                         if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
3401                                                                 if let &Some(ref source) = pending_source {
3402                                                                         log_claim!("revoked counterparty commitment tx", false, pending_htlc, true);
3403                                                                         payment_data = Some(((**source).clone(), $htlc_output.payment_hash, $htlc_output.amount_msat));
3404                                                                         break;
3405                                                                 }
3406                                                         }
3407                                                 }
3408                                         }
3409                                 }
3410                         }
3411
3412                         macro_rules! scan_commitment {
3413                                 ($htlcs: expr, $tx_info: expr, $holder_tx: expr) => {
3414                                         for (ref htlc_output, source_option) in $htlcs {
3415                                                 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
3416                                                         if let Some(ref source) = source_option {
3417                                                                 log_claim!($tx_info, $holder_tx, htlc_output, true);
3418                                                                 // We have a resolution of an HTLC either from one of our latest
3419                                                                 // holder commitment transactions or an unrevoked counterparty commitment
3420                                                                 // transaction. This implies we either learned a preimage, the HTLC
3421                                                                 // has timed out, or we screwed up. In any case, we should now
3422                                                                 // resolve the source HTLC with the original sender.
3423                                                                 payment_data = Some(((*source).clone(), htlc_output.payment_hash, htlc_output.amount_msat));
3424                                                         } else if !$holder_tx {
3425                                                                 check_htlc_valid_counterparty!(self.current_counterparty_commitment_txid, htlc_output);
3426                                                                 if payment_data.is_none() {
3427                                                                         check_htlc_valid_counterparty!(self.prev_counterparty_commitment_txid, htlc_output);
3428                                                                 }
3429                                                         }
3430                                                         if payment_data.is_none() {
3431                                                                 log_claim!($tx_info, $holder_tx, htlc_output, false);
3432                                                                 let outbound_htlc = $holder_tx == htlc_output.offered;
3433                                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3434                                                                         txid: tx.txid(), height, block_hash: Some(*block_hash), transaction: Some(tx.clone()),
3435                                                                         event: OnchainEvent::HTLCSpendConfirmation {
3436                                                                                 commitment_tx_output_idx: input.previous_output.vout,
3437                                                                                 preimage: if accepted_preimage_claim || offered_preimage_claim {
3438                                                                                         Some(payment_preimage) } else { None },
3439                                                                                 // If this is a payment to us (ie !outbound_htlc), wait for
3440                                                                                 // the CSV delay before dropping the HTLC from claimable
3441                                                                                 // balance if the claim was an HTLC-Success transaction (ie
3442                                                                                 // accepted_preimage_claim).
3443                                                                                 on_to_local_output_csv: if accepted_preimage_claim && !outbound_htlc {
3444                                                                                         Some(self.on_holder_tx_csv) } else { None },
3445                                                                         },
3446                                                                 });
3447                                                                 continue 'outer_loop;
3448                                                         }
3449                                                 }
3450                                         }
3451                                 }
3452                         }
3453
3454                         if input.previous_output.txid == self.current_holder_commitment_tx.txid {
3455                                 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
3456                                         "our latest holder commitment tx", true);
3457                         }
3458                         if let Some(ref prev_holder_signed_commitment_tx) = self.prev_holder_signed_commitment_tx {
3459                                 if input.previous_output.txid == prev_holder_signed_commitment_tx.txid {
3460                                         scan_commitment!(prev_holder_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
3461                                                 "our previous holder commitment tx", true);
3462                                 }
3463                         }
3464                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(&input.previous_output.txid) {
3465                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
3466                                         "counterparty commitment tx", false);
3467                         }
3468
3469                         // Check that scan_commitment, above, decided there is some source worth relaying an
3470                         // HTLC resolution backwards to and figure out whether we learned a preimage from it.
3471                         if let Some((source, payment_hash, amount_msat)) = payment_data {
3472                                 if accepted_preimage_claim {
3473                                         if !self.pending_monitor_events.iter().any(
3474                                                 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update { upd.source == source } else { false }) {
3475                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3476                                                         txid: tx.txid(),
3477                                                         height,
3478                                                         block_hash: Some(*block_hash),
3479                                                         transaction: Some(tx.clone()),
3480                                                         event: OnchainEvent::HTLCSpendConfirmation {
3481                                                                 commitment_tx_output_idx: input.previous_output.vout,
3482                                                                 preimage: Some(payment_preimage),
3483                                                                 on_to_local_output_csv: None,
3484                                                         },
3485                                                 });
3486                                                 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
3487                                                         source,
3488                                                         payment_preimage: Some(payment_preimage),
3489                                                         payment_hash,
3490                                                         htlc_value_satoshis: Some(amount_msat / 1000),
3491                                                 }));
3492                                         }
3493                                 } else if offered_preimage_claim {
3494                                         if !self.pending_monitor_events.iter().any(
3495                                                 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update {
3496                                                         upd.source == source
3497                                                 } else { false }) {
3498                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3499                                                         txid: tx.txid(),
3500                                                         transaction: Some(tx.clone()),
3501                                                         height,
3502                                                         block_hash: Some(*block_hash),
3503                                                         event: OnchainEvent::HTLCSpendConfirmation {
3504                                                                 commitment_tx_output_idx: input.previous_output.vout,
3505                                                                 preimage: Some(payment_preimage),
3506                                                                 on_to_local_output_csv: None,
3507                                                         },
3508                                                 });
3509                                                 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
3510                                                         source,
3511                                                         payment_preimage: Some(payment_preimage),
3512                                                         payment_hash,
3513                                                         htlc_value_satoshis: Some(amount_msat / 1000),
3514                                                 }));
3515                                         }
3516                                 } else {
3517                                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
3518                                                 if entry.height != height { return true; }
3519                                                 match entry.event {
3520                                                         OnchainEvent::HTLCUpdate { source: ref htlc_source, .. } => {
3521                                                                 *htlc_source != source
3522                                                         },
3523                                                         _ => true,
3524                                                 }
3525                                         });
3526                                         let entry = OnchainEventEntry {
3527                                                 txid: tx.txid(),
3528                                                 transaction: Some(tx.clone()),
3529                                                 height,
3530                                                 block_hash: Some(*block_hash),
3531                                                 event: OnchainEvent::HTLCUpdate {
3532                                                         source, payment_hash,
3533                                                         htlc_value_satoshis: Some(amount_msat / 1000),
3534                                                         commitment_tx_output_idx: Some(input.previous_output.vout),
3535                                                 },
3536                                         };
3537                                         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());
3538                                         self.onchain_events_awaiting_threshold_conf.push(entry);
3539                                 }
3540                         }
3541                 }
3542         }
3543
3544         /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
3545         fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, block_hash: &BlockHash, logger: &L) where L::Target: Logger {
3546                 let mut spendable_output = None;
3547                 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
3548                         if i > ::core::u16::MAX as usize {
3549                                 // While it is possible that an output exists on chain which is greater than the
3550                                 // 2^16th output in a given transaction, this is only possible if the output is not
3551                                 // in a lightning transaction and was instead placed there by some third party who
3552                                 // wishes to give us money for no reason.
3553                                 // Namely, any lightning transactions which we pre-sign will never have anywhere
3554                                 // near 2^16 outputs both because such transactions must have ~2^16 outputs who's
3555                                 // scripts are not longer than one byte in length and because they are inherently
3556                                 // non-standard due to their size.
3557                                 // Thus, it is completely safe to ignore such outputs, and while it may result in
3558                                 // us ignoring non-lightning fund to us, that is only possible if someone fills
3559                                 // nearly a full block with garbage just to hit this case.
3560                                 continue;
3561                         }
3562                         if outp.script_pubkey == self.destination_script {
3563                                 spendable_output =  Some(SpendableOutputDescriptor::StaticOutput {
3564                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3565                                         output: outp.clone(),
3566                                 });
3567                                 break;
3568                         }
3569                         if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
3570                                 if broadcasted_holder_revokable_script.0 == outp.script_pubkey {
3571                                         spendable_output =  Some(SpendableOutputDescriptor::DelayedPaymentOutput(DelayedPaymentOutputDescriptor {
3572                                                 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3573                                                 per_commitment_point: broadcasted_holder_revokable_script.1,
3574                                                 to_self_delay: self.on_holder_tx_csv,
3575                                                 output: outp.clone(),
3576                                                 revocation_pubkey: broadcasted_holder_revokable_script.2.clone(),
3577                                                 channel_keys_id: self.channel_keys_id,
3578                                                 channel_value_satoshis: self.channel_value_satoshis,
3579                                         }));
3580                                         break;
3581                                 }
3582                         }
3583                         if self.counterparty_payment_script == outp.script_pubkey {
3584                                 spendable_output = Some(SpendableOutputDescriptor::StaticPaymentOutput(StaticPaymentOutputDescriptor {
3585                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3586                                         output: outp.clone(),
3587                                         channel_keys_id: self.channel_keys_id,
3588                                         channel_value_satoshis: self.channel_value_satoshis,
3589                                 }));
3590                                 break;
3591                         }
3592                         if self.shutdown_script.as_ref() == Some(&outp.script_pubkey) {
3593                                 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
3594                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3595                                         output: outp.clone(),
3596                                 });
3597                                 break;
3598                         }
3599                 }
3600                 if let Some(spendable_output) = spendable_output {
3601                         let entry = OnchainEventEntry {
3602                                 txid: tx.txid(),
3603                                 transaction: Some(tx.clone()),
3604                                 height,
3605                                 block_hash: Some(*block_hash),
3606                                 event: OnchainEvent::MaturingOutput { descriptor: spendable_output.clone() },
3607                         };
3608                         log_info!(logger, "Received spendable output {}, spendable at height {}", log_spendable!(spendable_output), entry.confirmation_threshold());
3609                         self.onchain_events_awaiting_threshold_conf.push(entry);
3610                 }
3611         }
3612 }
3613
3614 impl<Signer: WriteableEcdsaChannelSigner, T: Deref, F: Deref, L: Deref> chain::Listen for (ChannelMonitor<Signer>, T, F, L)
3615 where
3616         T::Target: BroadcasterInterface,
3617         F::Target: FeeEstimator,
3618         L::Target: Logger,
3619 {
3620         fn filtered_block_connected(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
3621                 self.0.block_connected(header, txdata, height, &*self.1, &*self.2, &*self.3);
3622         }
3623
3624         fn block_disconnected(&self, header: &BlockHeader, height: u32) {
3625                 self.0.block_disconnected(header, height, &*self.1, &*self.2, &*self.3);
3626         }
3627 }
3628
3629 impl<Signer: WriteableEcdsaChannelSigner, T: Deref, F: Deref, L: Deref> chain::Confirm for (ChannelMonitor<Signer>, T, F, L)
3630 where
3631         T::Target: BroadcasterInterface,
3632         F::Target: FeeEstimator,
3633         L::Target: Logger,
3634 {
3635         fn transactions_confirmed(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
3636                 self.0.transactions_confirmed(header, txdata, height, &*self.1, &*self.2, &*self.3);
3637         }
3638
3639         fn transaction_unconfirmed(&self, txid: &Txid) {
3640                 self.0.transaction_unconfirmed(txid, &*self.1, &*self.2, &*self.3);
3641         }
3642
3643         fn best_block_updated(&self, header: &BlockHeader, height: u32) {
3644                 self.0.best_block_updated(header, height, &*self.1, &*self.2, &*self.3);
3645         }
3646
3647         fn get_relevant_txids(&self) -> Vec<(Txid, Option<BlockHash>)> {
3648                 self.0.get_relevant_txids()
3649         }
3650 }
3651
3652 const MAX_ALLOC_SIZE: usize = 64*1024;
3653
3654 impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP)>
3655                 for (BlockHash, ChannelMonitor<SP::Signer>) {
3656         fn read<R: io::Read>(reader: &mut R, args: (&'a ES, &'b SP)) -> Result<Self, DecodeError> {
3657                 macro_rules! unwrap_obj {
3658                         ($key: expr) => {
3659                                 match $key {
3660                                         Ok(res) => res,
3661                                         Err(_) => return Err(DecodeError::InvalidValue),
3662                                 }
3663                         }
3664                 }
3665
3666                 let (entropy_source, signer_provider) = args;
3667
3668                 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
3669
3670                 let latest_update_id: u64 = Readable::read(reader)?;
3671                 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
3672
3673                 let destination_script = Readable::read(reader)?;
3674                 let broadcasted_holder_revokable_script = match <u8 as Readable>::read(reader)? {
3675                         0 => {
3676                                 let revokable_address = Readable::read(reader)?;
3677                                 let per_commitment_point = Readable::read(reader)?;
3678                                 let revokable_script = Readable::read(reader)?;
3679                                 Some((revokable_address, per_commitment_point, revokable_script))
3680                         },
3681                         1 => { None },
3682                         _ => return Err(DecodeError::InvalidValue),
3683                 };
3684                 let counterparty_payment_script = Readable::read(reader)?;
3685                 let shutdown_script = {
3686                         let script = <Script as Readable>::read(reader)?;
3687                         if script.is_empty() { None } else { Some(script) }
3688                 };
3689
3690                 let channel_keys_id = Readable::read(reader)?;
3691                 let holder_revocation_basepoint = Readable::read(reader)?;
3692                 // Technically this can fail and serialize fail a round-trip, but only for serialization of
3693                 // barely-init'd ChannelMonitors that we can't do anything with.
3694                 let outpoint = OutPoint {
3695                         txid: Readable::read(reader)?,
3696                         index: Readable::read(reader)?,
3697                 };
3698                 let funding_info = (outpoint, Readable::read(reader)?);
3699                 let current_counterparty_commitment_txid = Readable::read(reader)?;
3700                 let prev_counterparty_commitment_txid = Readable::read(reader)?;
3701
3702                 let counterparty_commitment_params = Readable::read(reader)?;
3703                 let funding_redeemscript = Readable::read(reader)?;
3704                 let channel_value_satoshis = Readable::read(reader)?;
3705
3706                 let their_cur_per_commitment_points = {
3707                         let first_idx = <U48 as Readable>::read(reader)?.0;
3708                         if first_idx == 0 {
3709                                 None
3710                         } else {
3711                                 let first_point = Readable::read(reader)?;
3712                                 let second_point_slice: [u8; 33] = Readable::read(reader)?;
3713                                 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
3714                                         Some((first_idx, first_point, None))
3715                                 } else {
3716                                         Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
3717                                 }
3718                         }
3719                 };
3720
3721                 let on_holder_tx_csv: u16 = Readable::read(reader)?;
3722
3723                 let commitment_secrets = Readable::read(reader)?;
3724
3725                 macro_rules! read_htlc_in_commitment {
3726                         () => {
3727                                 {
3728                                         let offered: bool = Readable::read(reader)?;
3729                                         let amount_msat: u64 = Readable::read(reader)?;
3730                                         let cltv_expiry: u32 = Readable::read(reader)?;
3731                                         let payment_hash: PaymentHash = Readable::read(reader)?;
3732                                         let transaction_output_index: Option<u32> = Readable::read(reader)?;
3733
3734                                         HTLCOutputInCommitment {
3735                                                 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
3736                                         }
3737                                 }
3738                         }
3739                 }
3740
3741                 let counterparty_claimable_outpoints_len: u64 = Readable::read(reader)?;
3742                 let mut counterparty_claimable_outpoints = HashMap::with_capacity(cmp::min(counterparty_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
3743                 for _ in 0..counterparty_claimable_outpoints_len {
3744                         let txid: Txid = Readable::read(reader)?;
3745                         let htlcs_count: u64 = Readable::read(reader)?;
3746                         let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
3747                         for _ in 0..htlcs_count {
3748                                 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
3749                         }
3750                         if let Some(_) = counterparty_claimable_outpoints.insert(txid, htlcs) {
3751                                 return Err(DecodeError::InvalidValue);
3752                         }
3753                 }
3754
3755                 let counterparty_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
3756                 let mut counterparty_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(counterparty_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
3757                 for _ in 0..counterparty_commitment_txn_on_chain_len {
3758                         let txid: Txid = Readable::read(reader)?;
3759                         let commitment_number = <U48 as Readable>::read(reader)?.0;
3760                         if let Some(_) = counterparty_commitment_txn_on_chain.insert(txid, commitment_number) {
3761                                 return Err(DecodeError::InvalidValue);
3762                         }
3763                 }
3764
3765                 let counterparty_hash_commitment_number_len: u64 = Readable::read(reader)?;
3766                 let mut counterparty_hash_commitment_number = HashMap::with_capacity(cmp::min(counterparty_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
3767                 for _ in 0..counterparty_hash_commitment_number_len {
3768                         let payment_hash: PaymentHash = Readable::read(reader)?;
3769                         let commitment_number = <U48 as Readable>::read(reader)?.0;
3770                         if let Some(_) = counterparty_hash_commitment_number.insert(payment_hash, commitment_number) {
3771                                 return Err(DecodeError::InvalidValue);
3772                         }
3773                 }
3774
3775                 let mut prev_holder_signed_commitment_tx: Option<HolderSignedTx> =
3776                         match <u8 as Readable>::read(reader)? {
3777                                 0 => None,
3778                                 1 => {
3779                                         Some(Readable::read(reader)?)
3780                                 },
3781                                 _ => return Err(DecodeError::InvalidValue),
3782                         };
3783                 let mut current_holder_commitment_tx: HolderSignedTx = Readable::read(reader)?;
3784
3785                 let current_counterparty_commitment_number = <U48 as Readable>::read(reader)?.0;
3786                 let current_holder_commitment_number = <U48 as Readable>::read(reader)?.0;
3787
3788                 let payment_preimages_len: u64 = Readable::read(reader)?;
3789                 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
3790                 for _ in 0..payment_preimages_len {
3791                         let preimage: PaymentPreimage = Readable::read(reader)?;
3792                         let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
3793                         if let Some(_) = payment_preimages.insert(hash, preimage) {
3794                                 return Err(DecodeError::InvalidValue);
3795                         }
3796                 }
3797
3798                 let pending_monitor_events_len: u64 = Readable::read(reader)?;
3799                 let mut pending_monitor_events = Some(
3800                         Vec::with_capacity(cmp::min(pending_monitor_events_len as usize, MAX_ALLOC_SIZE / (32 + 8*3))));
3801                 for _ in 0..pending_monitor_events_len {
3802                         let ev = match <u8 as Readable>::read(reader)? {
3803                                 0 => MonitorEvent::HTLCEvent(Readable::read(reader)?),
3804                                 1 => MonitorEvent::CommitmentTxConfirmed(funding_info.0),
3805                                 _ => return Err(DecodeError::InvalidValue)
3806                         };
3807                         pending_monitor_events.as_mut().unwrap().push(ev);
3808                 }
3809
3810                 let pending_events_len: u64 = Readable::read(reader)?;
3811                 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Event>()));
3812                 for _ in 0..pending_events_len {
3813                         if let Some(event) = MaybeReadable::read(reader)? {
3814                                 pending_events.push(event);
3815                         }
3816                 }
3817
3818                 let best_block = BestBlock::new(Readable::read(reader)?, Readable::read(reader)?);
3819
3820                 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
3821                 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
3822                 for _ in 0..waiting_threshold_conf_len {
3823                         if let Some(val) = MaybeReadable::read(reader)? {
3824                                 onchain_events_awaiting_threshold_conf.push(val);
3825                         }
3826                 }
3827
3828                 let outputs_to_watch_len: u64 = Readable::read(reader)?;
3829                 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>>())));
3830                 for _ in 0..outputs_to_watch_len {
3831                         let txid = Readable::read(reader)?;
3832                         let outputs_len: u64 = Readable::read(reader)?;
3833                         let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / (mem::size_of::<u32>() + mem::size_of::<Script>())));
3834                         for _ in 0..outputs_len {
3835                                 outputs.push((Readable::read(reader)?, Readable::read(reader)?));
3836                         }
3837                         if let Some(_) = outputs_to_watch.insert(txid, outputs) {
3838                                 return Err(DecodeError::InvalidValue);
3839                         }
3840                 }
3841                 let onchain_tx_handler: OnchainTxHandler<SP::Signer> = ReadableArgs::read(
3842                         reader, (entropy_source, signer_provider, channel_value_satoshis, channel_keys_id)
3843                 )?;
3844
3845                 let lockdown_from_offchain = Readable::read(reader)?;
3846                 let holder_tx_signed = Readable::read(reader)?;
3847
3848                 if let Some(prev_commitment_tx) = prev_holder_signed_commitment_tx.as_mut() {
3849                         let prev_holder_value = onchain_tx_handler.get_prev_holder_commitment_to_self_value();
3850                         if prev_holder_value.is_none() { return Err(DecodeError::InvalidValue); }
3851                         if prev_commitment_tx.to_self_value_sat == u64::max_value() {
3852                                 prev_commitment_tx.to_self_value_sat = prev_holder_value.unwrap();
3853                         } else if prev_commitment_tx.to_self_value_sat != prev_holder_value.unwrap() {
3854                                 return Err(DecodeError::InvalidValue);
3855                         }
3856                 }
3857
3858                 let cur_holder_value = onchain_tx_handler.get_cur_holder_commitment_to_self_value();
3859                 if current_holder_commitment_tx.to_self_value_sat == u64::max_value() {
3860                         current_holder_commitment_tx.to_self_value_sat = cur_holder_value;
3861                 } else if current_holder_commitment_tx.to_self_value_sat != cur_holder_value {
3862                         return Err(DecodeError::InvalidValue);
3863                 }
3864
3865                 let mut funding_spend_confirmed = None;
3866                 let mut htlcs_resolved_on_chain = Some(Vec::new());
3867                 let mut funding_spend_seen = Some(false);
3868                 let mut counterparty_node_id = None;
3869                 let mut confirmed_commitment_tx_counterparty_output = None;
3870                 let mut spendable_txids_confirmed = Some(Vec::new());
3871                 read_tlv_fields!(reader, {
3872                         (1, funding_spend_confirmed, option),
3873                         (3, htlcs_resolved_on_chain, vec_type),
3874                         (5, pending_monitor_events, vec_type),
3875                         (7, funding_spend_seen, option),
3876                         (9, counterparty_node_id, option),
3877                         (11, confirmed_commitment_tx_counterparty_output, option),
3878                         (13, spendable_txids_confirmed, vec_type),
3879                 });
3880
3881                 Ok((best_block.block_hash(), ChannelMonitor::from_impl(ChannelMonitorImpl {
3882                         latest_update_id,
3883                         commitment_transaction_number_obscure_factor,
3884
3885                         destination_script,
3886                         broadcasted_holder_revokable_script,
3887                         counterparty_payment_script,
3888                         shutdown_script,
3889
3890                         channel_keys_id,
3891                         holder_revocation_basepoint,
3892                         funding_info,
3893                         current_counterparty_commitment_txid,
3894                         prev_counterparty_commitment_txid,
3895
3896                         counterparty_commitment_params,
3897                         funding_redeemscript,
3898                         channel_value_satoshis,
3899                         their_cur_per_commitment_points,
3900
3901                         on_holder_tx_csv,
3902
3903                         commitment_secrets,
3904                         counterparty_claimable_outpoints,
3905                         counterparty_commitment_txn_on_chain,
3906                         counterparty_hash_commitment_number,
3907
3908                         prev_holder_signed_commitment_tx,
3909                         current_holder_commitment_tx,
3910                         current_counterparty_commitment_number,
3911                         current_holder_commitment_number,
3912
3913                         payment_preimages,
3914                         pending_monitor_events: pending_monitor_events.unwrap(),
3915                         pending_events,
3916
3917                         onchain_events_awaiting_threshold_conf,
3918                         outputs_to_watch,
3919
3920                         onchain_tx_handler,
3921
3922                         lockdown_from_offchain,
3923                         holder_tx_signed,
3924                         funding_spend_seen: funding_spend_seen.unwrap(),
3925                         funding_spend_confirmed,
3926                         confirmed_commitment_tx_counterparty_output,
3927                         htlcs_resolved_on_chain: htlcs_resolved_on_chain.unwrap(),
3928                         spendable_txids_confirmed: spendable_txids_confirmed.unwrap(),
3929
3930                         best_block,
3931                         counterparty_node_id,
3932                 })))
3933         }
3934 }
3935
3936 #[cfg(test)]
3937 mod tests {
3938         use bitcoin::blockdata::block::BlockHeader;
3939         use bitcoin::blockdata::script::{Script, Builder};
3940         use bitcoin::blockdata::opcodes;
3941         use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, EcdsaSighashType};
3942         use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
3943         use bitcoin::util::sighash;
3944         use bitcoin::hashes::Hash;
3945         use bitcoin::hashes::sha256::Hash as Sha256;
3946         use bitcoin::hashes::hex::FromHex;
3947         use bitcoin::hash_types::{BlockHash, Txid};
3948         use bitcoin::network::constants::Network;
3949         use bitcoin::secp256k1::{SecretKey,PublicKey};
3950         use bitcoin::secp256k1::Secp256k1;
3951
3952         use hex;
3953
3954         use crate::chain::chaininterface::LowerBoundedFeeEstimator;
3955
3956         use super::ChannelMonitorUpdateStep;
3957         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};
3958         use crate::chain::{BestBlock, Confirm};
3959         use crate::chain::channelmonitor::ChannelMonitor;
3960         use crate::chain::package::{weight_offered_htlc, weight_received_htlc, weight_revoked_offered_htlc, weight_revoked_received_htlc, WEIGHT_REVOKED_OUTPUT};
3961         use crate::chain::transaction::OutPoint;
3962         use crate::chain::keysinterface::InMemorySigner;
3963         use crate::ln::{PaymentPreimage, PaymentHash};
3964         use crate::ln::chan_utils;
3965         use crate::ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
3966         use crate::ln::channelmanager::{PaymentSendFailure, PaymentId};
3967         use crate::ln::functional_test_utils::*;
3968         use crate::ln::script::ShutdownScript;
3969         use crate::util::errors::APIError;
3970         use crate::util::events::{ClosureReason, MessageSendEventsProvider};
3971         use crate::util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};
3972         use crate::util::ser::{ReadableArgs, Writeable};
3973         use crate::sync::{Arc, Mutex};
3974         use crate::io;
3975         use bitcoin::{PackedLockTime, Sequence, TxMerkleNode, Witness};
3976         use crate::prelude::*;
3977
3978         fn do_test_funding_spend_refuses_updates(use_local_txn: bool) {
3979                 // Previously, monitor updates were allowed freely even after a funding-spend transaction
3980                 // confirmed. This would allow a race condition where we could receive a payment (including
3981                 // the counterparty revoking their broadcasted state!) and accept it without recourse as
3982                 // long as the ChannelMonitor receives the block first, the full commitment update dance
3983                 // occurs after the block is connected, and before the ChannelManager receives the block.
3984                 // Obviously this is an incredibly contrived race given the counterparty would be risking
3985                 // their full channel balance for it, but its worth fixing nonetheless as it makes the
3986                 // potential ChannelMonitor states simpler to reason about.
3987                 //
3988                 // This test checks said behavior, as well as ensuring a ChannelMonitorUpdate with multiple
3989                 // updates is handled correctly in such conditions.
3990                 let chanmon_cfgs = create_chanmon_cfgs(3);
3991                 let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
3992                 let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
3993                 let nodes = create_network(3, &node_cfgs, &node_chanmgrs);
3994                 let channel = create_announced_chan_between_nodes(&nodes, 0, 1);
3995                 create_announced_chan_between_nodes(&nodes, 1, 2);
3996
3997                 // Rebalance somewhat
3998                 send_payment(&nodes[0], &[&nodes[1]], 10_000_000);
3999
4000                 // First route two payments for testing at the end
4001                 let payment_preimage_1 = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 1_000_000).0;
4002                 let payment_preimage_2 = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 1_000_000).0;
4003
4004                 let local_txn = get_local_commitment_txn!(nodes[1], channel.2);
4005                 assert_eq!(local_txn.len(), 1);
4006                 let remote_txn = get_local_commitment_txn!(nodes[0], channel.2);
4007                 assert_eq!(remote_txn.len(), 3); // Commitment and two HTLC-Timeouts
4008                 check_spends!(remote_txn[1], remote_txn[0]);
4009                 check_spends!(remote_txn[2], remote_txn[0]);
4010                 let broadcast_tx = if use_local_txn { &local_txn[0] } else { &remote_txn[0] };
4011
4012                 // Connect a commitment transaction, but only to the ChainMonitor/ChannelMonitor. The
4013                 // channel is now closed, but the ChannelManager doesn't know that yet.
4014                 let new_header = BlockHeader {
4015                         version: 2, time: 0, bits: 0, nonce: 0,
4016                         prev_blockhash: nodes[0].best_block_info().0,
4017                         merkle_root: TxMerkleNode::all_zeros() };
4018                 let conf_height = nodes[0].best_block_info().1 + 1;
4019                 nodes[1].chain_monitor.chain_monitor.transactions_confirmed(&new_header,
4020                         &[(0, broadcast_tx)], conf_height);
4021
4022                 let (_, pre_update_monitor) = <(BlockHash, ChannelMonitor<InMemorySigner>)>::read(
4023                                                 &mut io::Cursor::new(&get_monitor!(nodes[1], channel.2).encode()),
4024                                                 (&nodes[1].keys_manager.backing, &nodes[1].keys_manager.backing)).unwrap();
4025
4026                 // If the ChannelManager tries to update the channel, however, the ChainMonitor will pass
4027                 // the update through to the ChannelMonitor which will refuse it (as the channel is closed).
4028                 let (route, payment_hash, _, payment_secret) = get_route_and_payment_hash!(nodes[1], nodes[0], 100_000);
4029                 unwrap_send_err!(nodes[1].node.send_payment(&route, payment_hash, &Some(payment_secret), PaymentId(payment_hash.0)),
4030                         true, APIError::ChannelUnavailable { ref err },
4031                         assert!(err.contains("ChannelMonitor storage failure")));
4032                 check_added_monitors!(nodes[1], 2); // After the failure we generate a close-channel monitor update
4033                 check_closed_broadcast!(nodes[1], true);
4034                 check_closed_event!(nodes[1], 1, ClosureReason::ProcessingError { err: "ChannelMonitor storage failure".to_string() });
4035
4036                 // Build a new ChannelMonitorUpdate which contains both the failing commitment tx update
4037                 // and provides the claim preimages for the two pending HTLCs. The first update generates
4038                 // an error, but the point of this test is to ensure the later updates are still applied.
4039                 let monitor_updates = nodes[1].chain_monitor.monitor_updates.lock().unwrap();
4040                 let mut replay_update = monitor_updates.get(&channel.2).unwrap().iter().rev().skip(1).next().unwrap().clone();
4041                 assert_eq!(replay_update.updates.len(), 1);
4042                 if let ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { .. } = replay_update.updates[0] {
4043                 } else { panic!(); }
4044                 replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_1 });
4045                 replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_2 });
4046
4047                 let broadcaster = TestBroadcaster::new(Arc::clone(&nodes[1].blocks));
4048                 assert!(
4049                         pre_update_monitor.update_monitor(&replay_update, &&broadcaster, &chanmon_cfgs[1].fee_estimator, &nodes[1].logger)
4050                         .is_err());
4051                 // Even though we error'd on the first update, we should still have generated an HTLC claim
4052                 // transaction
4053                 let txn_broadcasted = broadcaster.txn_broadcasted.lock().unwrap().split_off(0);
4054                 assert!(txn_broadcasted.len() >= 2);
4055                 let htlc_txn = txn_broadcasted.iter().filter(|tx| {
4056                         assert_eq!(tx.input.len(), 1);
4057                         tx.input[0].previous_output.txid == broadcast_tx.txid()
4058                 }).collect::<Vec<_>>();
4059                 assert_eq!(htlc_txn.len(), 2);
4060                 check_spends!(htlc_txn[0], broadcast_tx);
4061                 check_spends!(htlc_txn[1], broadcast_tx);
4062         }
4063         #[test]
4064         fn test_funding_spend_refuses_updates() {
4065                 do_test_funding_spend_refuses_updates(true);
4066                 do_test_funding_spend_refuses_updates(false);
4067         }
4068
4069         #[test]
4070         fn test_prune_preimages() {
4071                 let secp_ctx = Secp256k1::new();
4072                 let logger = Arc::new(TestLogger::new());
4073                 let broadcaster = Arc::new(TestBroadcaster {
4074                         txn_broadcasted: Mutex::new(Vec::new()),
4075                         blocks: Arc::new(Mutex::new(Vec::new()))
4076                 });
4077                 let fee_estimator = TestFeeEstimator { sat_per_kw: Mutex::new(253) };
4078
4079                 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
4080                 let dummy_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
4081
4082                 let mut preimages = Vec::new();
4083                 {
4084                         for i in 0..20 {
4085                                 let preimage = PaymentPreimage([i; 32]);
4086                                 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
4087                                 preimages.push((preimage, hash));
4088                         }
4089                 }
4090
4091                 macro_rules! preimages_slice_to_htlc_outputs {
4092                         ($preimages_slice: expr) => {
4093                                 {
4094                                         let mut res = Vec::new();
4095                                         for (idx, preimage) in $preimages_slice.iter().enumerate() {
4096                                                 res.push((HTLCOutputInCommitment {
4097                                                         offered: true,
4098                                                         amount_msat: 0,
4099                                                         cltv_expiry: 0,
4100                                                         payment_hash: preimage.1.clone(),
4101                                                         transaction_output_index: Some(idx as u32),
4102                                                 }, None));
4103                                         }
4104                                         res
4105                                 }
4106                         }
4107                 }
4108                 macro_rules! preimages_to_holder_htlcs {
4109                         ($preimages_slice: expr) => {
4110                                 {
4111                                         let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
4112                                         let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
4113                                         res
4114                                 }
4115                         }
4116                 }
4117
4118                 macro_rules! test_preimages_exist {
4119                         ($preimages_slice: expr, $monitor: expr) => {
4120                                 for preimage in $preimages_slice {
4121                                         assert!($monitor.inner.lock().unwrap().payment_preimages.contains_key(&preimage.1));
4122                                 }
4123                         }
4124                 }
4125
4126                 let keys = InMemorySigner::new(
4127                         &secp_ctx,
4128                         SecretKey::from_slice(&[41; 32]).unwrap(),
4129                         SecretKey::from_slice(&[41; 32]).unwrap(),
4130                         SecretKey::from_slice(&[41; 32]).unwrap(),
4131                         SecretKey::from_slice(&[41; 32]).unwrap(),
4132                         SecretKey::from_slice(&[41; 32]).unwrap(),
4133                         [41; 32],
4134                         0,
4135                         [0; 32],
4136                 );
4137
4138                 let counterparty_pubkeys = ChannelPublicKeys {
4139                         funding_pubkey: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
4140                         revocation_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
4141                         payment_point: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[46; 32]).unwrap()),
4142                         delayed_payment_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[47; 32]).unwrap()),
4143                         htlc_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[48; 32]).unwrap())
4144                 };
4145                 let funding_outpoint = OutPoint { txid: Txid::all_zeros(), index: u16::max_value() };
4146                 let channel_parameters = ChannelTransactionParameters {
4147                         holder_pubkeys: keys.holder_channel_pubkeys.clone(),
4148                         holder_selected_contest_delay: 66,
4149                         is_outbound_from_holder: true,
4150                         counterparty_parameters: Some(CounterpartyChannelTransactionParameters {
4151                                 pubkeys: counterparty_pubkeys,
4152                                 selected_contest_delay: 67,
4153                         }),
4154                         funding_outpoint: Some(funding_outpoint),
4155                         opt_anchors: None,
4156                         opt_non_zero_fee_anchors: None,
4157                 };
4158                 // Prune with one old state and a holder commitment tx holding a few overlaps with the
4159                 // old state.
4160                 let shutdown_pubkey = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
4161                 let best_block = BestBlock::from_network(Network::Testnet);
4162                 let monitor = ChannelMonitor::new(Secp256k1::new(), keys,
4163                                                   Some(ShutdownScript::new_p2wpkh_from_pubkey(shutdown_pubkey).into_inner()), 0, &Script::new(),
4164                                                   (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
4165                                                   &channel_parameters,
4166                                                   Script::new(), 46, 0,
4167                                                   HolderCommitmentTransaction::dummy(), best_block, dummy_key);
4168
4169                 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..10])).unwrap();
4170                 let dummy_txid = dummy_tx.txid();
4171                 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
4172                 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
4173                 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
4174                 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
4175                 for &(ref preimage, ref hash) in preimages.iter() {
4176                         let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&fee_estimator);
4177                         monitor.provide_payment_preimage(hash, preimage, &broadcaster, &bounded_fee_estimator, &logger);
4178                 }
4179
4180                 // Now provide a secret, pruning preimages 10-15
4181                 let mut secret = [0; 32];
4182                 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
4183                 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
4184                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 15);
4185                 test_preimages_exist!(&preimages[0..10], monitor);
4186                 test_preimages_exist!(&preimages[15..20], monitor);
4187
4188                 // Now provide a further secret, pruning preimages 15-17
4189                 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
4190                 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
4191                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 13);
4192                 test_preimages_exist!(&preimages[0..10], monitor);
4193                 test_preimages_exist!(&preimages[17..20], monitor);
4194
4195                 // Now update holder commitment tx info, pruning only element 18 as we still care about the
4196                 // previous commitment tx's preimages too
4197                 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..5])).unwrap();
4198                 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
4199                 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
4200                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 12);
4201                 test_preimages_exist!(&preimages[0..10], monitor);
4202                 test_preimages_exist!(&preimages[18..20], monitor);
4203
4204                 // But if we do it again, we'll prune 5-10
4205                 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..3])).unwrap();
4206                 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
4207                 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
4208                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 5);
4209                 test_preimages_exist!(&preimages[0..5], monitor);
4210         }
4211
4212         #[test]
4213         fn test_claim_txn_weight_computation() {
4214                 // We test Claim txn weight, knowing that we want expected weigth and
4215                 // not actual case to avoid sigs and time-lock delays hell variances.
4216
4217                 let secp_ctx = Secp256k1::new();
4218                 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
4219                 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
4220
4221                 macro_rules! sign_input {
4222                         ($sighash_parts: expr, $idx: expr, $amount: expr, $weight: expr, $sum_actual_sigs: expr, $opt_anchors: expr) => {
4223                                 let htlc = HTLCOutputInCommitment {
4224                                         offered: if *$weight == weight_revoked_offered_htlc($opt_anchors) || *$weight == weight_offered_htlc($opt_anchors) { true } else { false },
4225                                         amount_msat: 0,
4226                                         cltv_expiry: 2 << 16,
4227                                         payment_hash: PaymentHash([1; 32]),
4228                                         transaction_output_index: Some($idx as u32),
4229                                 };
4230                                 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, $opt_anchors, &pubkey, &pubkey, &pubkey) };
4231                                 let sighash = hash_to_message!(&$sighash_parts.segwit_signature_hash($idx, &redeem_script, $amount, EcdsaSighashType::All).unwrap()[..]);
4232                                 let sig = secp_ctx.sign_ecdsa(&sighash, &privkey);
4233                                 let mut ser_sig = sig.serialize_der().to_vec();
4234                                 ser_sig.push(EcdsaSighashType::All as u8);
4235                                 $sum_actual_sigs += ser_sig.len();
4236                                 let witness = $sighash_parts.witness_mut($idx).unwrap();
4237                                 witness.push(ser_sig);
4238                                 if *$weight == WEIGHT_REVOKED_OUTPUT {
4239                                         witness.push(vec!(1));
4240                                 } else if *$weight == weight_revoked_offered_htlc($opt_anchors) || *$weight == weight_revoked_received_htlc($opt_anchors) {
4241                                         witness.push(pubkey.clone().serialize().to_vec());
4242                                 } else if *$weight == weight_received_htlc($opt_anchors) {
4243                                         witness.push(vec![0]);
4244                                 } else {
4245                                         witness.push(PaymentPreimage([1; 32]).0.to_vec());
4246                                 }
4247                                 witness.push(redeem_script.into_bytes());
4248                                 let witness = witness.to_vec();
4249                                 println!("witness[0] {}", witness[0].len());
4250                                 println!("witness[1] {}", witness[1].len());
4251                                 println!("witness[2] {}", witness[2].len());
4252                         }
4253                 }
4254
4255                 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
4256                 let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
4257
4258                 // Justice tx with 1 to_holder, 2 revoked offered HTLCs, 1 revoked received HTLCs
4259                 for &opt_anchors in [false, true].iter() {
4260                         let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
4261                         let mut sum_actual_sigs = 0;
4262                         for i in 0..4 {
4263                                 claim_tx.input.push(TxIn {
4264                                         previous_output: BitcoinOutPoint {
4265                                                 txid,
4266                                                 vout: i,
4267                                         },
4268                                         script_sig: Script::new(),
4269                                         sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
4270                                         witness: Witness::new(),
4271                                 });
4272                         }
4273                         claim_tx.output.push(TxOut {
4274                                 script_pubkey: script_pubkey.clone(),
4275                                 value: 0,
4276                         });
4277                         let base_weight = claim_tx.weight();
4278                         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)];
4279                         let mut inputs_total_weight = 2; // count segwit flags
4280                         {
4281                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
4282                                 for (idx, inp) in inputs_weight.iter().enumerate() {
4283                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
4284                                         inputs_total_weight += inp;
4285                                 }
4286                         }
4287                         assert_eq!(base_weight + inputs_total_weight as usize,  claim_tx.weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
4288                 }
4289
4290                 // Claim tx with 1 offered HTLCs, 3 received HTLCs
4291                 for &opt_anchors in [false, true].iter() {
4292                         let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
4293                         let mut sum_actual_sigs = 0;
4294                         for i in 0..4 {
4295                                 claim_tx.input.push(TxIn {
4296                                         previous_output: BitcoinOutPoint {
4297                                                 txid,
4298                                                 vout: i,
4299                                         },
4300                                         script_sig: Script::new(),
4301                                         sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
4302                                         witness: Witness::new(),
4303                                 });
4304                         }
4305                         claim_tx.output.push(TxOut {
4306                                 script_pubkey: script_pubkey.clone(),
4307                                 value: 0,
4308                         });
4309                         let base_weight = claim_tx.weight();
4310                         let inputs_weight = vec![weight_offered_htlc(opt_anchors), weight_received_htlc(opt_anchors), weight_received_htlc(opt_anchors), weight_received_htlc(opt_anchors)];
4311                         let mut inputs_total_weight = 2; // count segwit flags
4312                         {
4313                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
4314                                 for (idx, inp) in inputs_weight.iter().enumerate() {
4315                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
4316                                         inputs_total_weight += inp;
4317                                 }
4318                         }
4319                         assert_eq!(base_weight + inputs_total_weight as usize,  claim_tx.weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
4320                 }
4321
4322                 // Justice tx with 1 revoked HTLC-Success tx output
4323                 for &opt_anchors in [false, true].iter() {
4324                         let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
4325                         let mut sum_actual_sigs = 0;
4326                         claim_tx.input.push(TxIn {
4327                                 previous_output: BitcoinOutPoint {
4328                                         txid,
4329                                         vout: 0,
4330                                 },
4331                                 script_sig: Script::new(),
4332                                 sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
4333                                 witness: Witness::new(),
4334                         });
4335                         claim_tx.output.push(TxOut {
4336                                 script_pubkey: script_pubkey.clone(),
4337                                 value: 0,
4338                         });
4339                         let base_weight = claim_tx.weight();
4340                         let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT];
4341                         let mut inputs_total_weight = 2; // count segwit flags
4342                         {
4343                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
4344                                 for (idx, inp) in inputs_weight.iter().enumerate() {
4345                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
4346                                         inputs_total_weight += inp;
4347                                 }
4348                         }
4349                         assert_eq!(base_weight + inputs_total_weight as usize, claim_tx.weight() + /* max_length_isg */ (73 * inputs_weight.len() - sum_actual_sigs));
4350                 }
4351         }
4352
4353         // Further testing is done in the ChannelManager integration tests.
4354 }