1 // This file is Copyright its original authors, visible in version control
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
10 //! The logic to monitor for on-chain transactions and create the relevant claim responses lives
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.
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 latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date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.
23 use bitcoin::blockdata::block::{Block, BlockHeader};
24 use bitcoin::blockdata::transaction::{TxOut,Transaction};
25 use bitcoin::blockdata::script::{Script, Builder};
26 use bitcoin::blockdata::opcodes;
28 use bitcoin::hashes::Hash;
29 use bitcoin::hashes::sha256::Hash as Sha256;
30 use bitcoin::hash_types::{Txid, BlockHash, WPubkeyHash};
32 use bitcoin::secp256k1::{Secp256k1,Signature};
33 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
34 use bitcoin::secp256k1;
36 use ln::{PaymentHash, PaymentPreimage};
37 use ln::msgs::DecodeError;
39 use ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, HTLCType, ChannelTransactionParameters, HolderCommitmentTransaction};
40 use ln::channelmanager::HTLCSource;
42 use chain::{BestBlock, WatchedOutput};
43 use chain::chaininterface::{BroadcasterInterface, FeeEstimator};
44 use chain::transaction::{OutPoint, TransactionData};
45 use chain::keysinterface::{SpendableOutputDescriptor, StaticPaymentOutputDescriptor, DelayedPaymentOutputDescriptor, Sign, KeysInterface};
46 use chain::onchaintx::OnchainTxHandler;
47 use chain::package::{CounterpartyOfferedHTLCOutput, CounterpartyReceivedHTLCOutput, HolderFundingOutput, HolderHTLCOutput, PackageSolvingData, PackageTemplate, RevokedOutput, RevokedHTLCOutput};
49 use util::logger::Logger;
50 use util::ser::{Readable, ReadableArgs, MaybeReadable, Writer, Writeable, U48, OptionDeserWrapper};
52 use util::events::Event;
56 use io::{self, Error};
60 /// An update generated by the underlying Channel itself which contains some new information the
61 /// ChannelMonitor should be made aware of.
62 #[cfg_attr(any(test, feature = "fuzztarget", feature = "_test_utils"), derive(PartialEq))]
65 pub struct ChannelMonitorUpdate {
66 pub(crate) updates: Vec<ChannelMonitorUpdateStep>,
67 /// The sequence number of this update. Updates *must* be replayed in-order according to this
68 /// sequence number (and updates may panic if they are not). The update_id values are strictly
69 /// increasing and increase by one for each new update, with one exception specified below.
71 /// This sequence number is also used to track up to which points updates which returned
72 /// ChannelMonitorUpdateErr::TemporaryFailure have been applied to all copies of a given
73 /// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
75 /// The only instance where update_id values are not strictly increasing is the case where we
76 /// allow post-force-close updates with a special update ID of [`CLOSED_CHANNEL_UPDATE_ID`]. See
77 /// its docs for more details.
82 /// (1) a channel has been force closed and
83 /// (2) we receive a preimage from a forward link that allows us to spend an HTLC output on
84 /// this channel's (the backward link's) broadcasted commitment transaction
85 /// then we allow the `ChannelManager` to send a `ChannelMonitorUpdate` with this update ID,
86 /// with the update providing said payment preimage. No other update types are allowed after
88 pub const CLOSED_CHANNEL_UPDATE_ID: u64 = core::u64::MAX;
90 impl Writeable for ChannelMonitorUpdate {
91 fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
92 write_ver_prefix!(w, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
93 self.update_id.write(w)?;
94 (self.updates.len() as u64).write(w)?;
95 for update_step in self.updates.iter() {
96 update_step.write(w)?;
98 write_tlv_fields!(w, {});
102 impl Readable for ChannelMonitorUpdate {
103 fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
104 let _ver = read_ver_prefix!(r, SERIALIZATION_VERSION);
105 let update_id: u64 = Readable::read(r)?;
106 let len: u64 = Readable::read(r)?;
107 let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::core::mem::size_of::<ChannelMonitorUpdateStep>()));
109 if let Some(upd) = MaybeReadable::read(r)? {
113 read_tlv_fields!(r, {});
114 Ok(Self { update_id, updates })
118 /// General Err type for ChannelMonitor actions. Generally, this implies that the data provided is
119 /// inconsistent with the ChannelMonitor being called. eg for ChannelMonitor::update_monitor this
120 /// means you tried to update a monitor for a different channel or the ChannelMonitorUpdate was
122 /// Contains a developer-readable error message.
123 #[derive(Clone, Debug)]
124 pub struct MonitorUpdateError(pub &'static str);
126 /// An event to be processed by the ChannelManager.
127 #[derive(Clone, PartialEq)]
128 pub enum MonitorEvent {
129 /// A monitor event containing an HTLCUpdate.
130 HTLCEvent(HTLCUpdate),
132 /// A monitor event that the Channel's commitment transaction was confirmed.
133 CommitmentTxConfirmed(OutPoint),
135 /// Indicates a [`ChannelMonitor`] update has completed. See
136 /// [`ChannelMonitorUpdateErr::TemporaryFailure`] for more information on how this is used.
138 /// [`ChannelMonitorUpdateErr::TemporaryFailure`]: super::ChannelMonitorUpdateErr::TemporaryFailure
140 /// The funding outpoint of the [`ChannelMonitor`] that was updated
141 funding_txo: OutPoint,
142 /// The Update ID from [`ChannelMonitorUpdate::update_id`] which was applied or
143 /// [`ChannelMonitor::get_latest_update_id`].
145 /// Note that this should only be set to a given update's ID if all previous updates for the
146 /// same [`ChannelMonitor`] have been applied and persisted.
147 monitor_update_id: u64,
150 /// Indicates a [`ChannelMonitor`] update has failed. See
151 /// [`ChannelMonitorUpdateErr::PermanentFailure`] for more information on how this is used.
153 /// [`ChannelMonitorUpdateErr::PermanentFailure`]: super::ChannelMonitorUpdateErr::PermanentFailure
154 UpdateFailed(OutPoint),
156 impl_writeable_tlv_based_enum_upgradable!(MonitorEvent,
157 // Note that UpdateCompleted and UpdateFailed are currently never serialized to disk as they are
158 // generated only in ChainMonitor
159 (0, UpdateCompleted) => {
160 (0, funding_txo, required),
161 (2, monitor_update_id, required),
165 (4, CommitmentTxConfirmed),
169 /// Simple structure sent back by `chain::Watch` when an HTLC from a forward channel is detected on
170 /// chain. Used to update the corresponding HTLC in the backward channel. Failing to pass the
171 /// preimage claim backward will lead to loss of funds.
172 #[derive(Clone, PartialEq)]
173 pub struct HTLCUpdate {
174 pub(crate) payment_hash: PaymentHash,
175 pub(crate) payment_preimage: Option<PaymentPreimage>,
176 pub(crate) source: HTLCSource,
177 pub(crate) onchain_value_satoshis: Option<u64>,
179 impl_writeable_tlv_based!(HTLCUpdate, {
180 (0, payment_hash, required),
181 (1, onchain_value_satoshis, option),
182 (2, source, required),
183 (4, payment_preimage, option),
186 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
187 /// instead claiming it in its own individual transaction.
188 pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
189 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
190 /// HTLC-Success transaction.
191 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
192 /// transaction confirmed (and we use it in a few more, equivalent, places).
193 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 18;
194 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
195 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
196 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
197 /// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
198 /// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
199 /// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
200 /// due to expiration but increase the cost of funds being locked longuer in case of failure.
201 /// This delay also cover a low-power peer being slow to process blocks and so being behind us on
202 /// accurate block height.
203 /// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
204 /// with at worst this delay, so we are not only using this value as a mercy for them but also
205 /// us as a safeguard to delay with enough time.
206 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
207 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding
208 /// inbound HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us
211 /// Note that this is a library-wide security assumption. If a reorg deeper than this number of
212 /// blocks occurs, counterparties may be able to steal funds or claims made by and balances exposed
213 /// by a [`ChannelMonitor`] may be incorrect.
214 // We also use this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
215 // It may cause spurious generation of bumped claim txn but that's alright given the outpoint is already
216 // solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
217 // keep bumping another claim tx to solve the outpoint.
218 pub const ANTI_REORG_DELAY: u32 = 6;
219 /// Number of blocks before confirmation at which we fail back an un-relayed HTLC or at which we
220 /// refuse to accept a new HTLC.
222 /// This is used for a few separate purposes:
223 /// 1) if we've received an MPP HTLC to us and it expires within this many blocks and we are
224 /// waiting on additional parts (or waiting on the preimage for any HTLC from the user), we will
226 /// 2) if we receive an HTLC within this many blocks of its expiry (plus one to avoid a race
227 /// condition with the above), we will fail this HTLC without telling the user we received it,
228 /// 3) if we are waiting on a connection or a channel state update to send an HTLC to a peer, and
229 /// that HTLC expires within this many blocks, we will simply fail the HTLC instead.
231 /// (1) is all about protecting us - we need enough time to update the channel state before we hit
232 /// CLTV_CLAIM_BUFFER, at which point we'd go on chain to claim the HTLC with the preimage.
234 /// (2) is the same, but with an additional buffer to avoid accepting an HTLC which is immediately
235 /// in a race condition between the user connecting a block (which would fail it) and the user
236 /// providing us the preimage (which would claim it).
238 /// (3) is about our counterparty - we don't want to relay an HTLC to a counterparty when they may
239 /// end up force-closing the channel on us to claim it.
240 pub(crate) const HTLC_FAIL_BACK_BUFFER: u32 = CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS;
242 // TODO(devrandom) replace this with HolderCommitmentTransaction
243 #[derive(Clone, PartialEq)]
244 struct HolderSignedTx {
245 /// txid of the transaction in tx, just used to make comparison faster
247 revocation_key: PublicKey,
248 a_htlc_key: PublicKey,
249 b_htlc_key: PublicKey,
250 delayed_payment_key: PublicKey,
251 per_commitment_point: PublicKey,
252 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
253 to_self_value_sat: u64,
256 impl_writeable_tlv_based!(HolderSignedTx, {
258 // Note that this is filled in with data from OnchainTxHandler if it's missing.
259 // For HolderSignedTx objects serialized with 0.0.100+, this should be filled in.
260 (1, to_self_value_sat, (default_value, u64::max_value())),
261 (2, revocation_key, required),
262 (4, a_htlc_key, required),
263 (6, b_htlc_key, required),
264 (8, delayed_payment_key, required),
265 (10, per_commitment_point, required),
266 (12, feerate_per_kw, required),
267 (14, htlc_outputs, vec_type)
270 /// We use this to track static counterparty commitment transaction data and to generate any
271 /// justice or 2nd-stage preimage/timeout transactions.
273 struct CounterpartyCommitmentParameters {
274 counterparty_delayed_payment_base_key: PublicKey,
275 counterparty_htlc_base_key: PublicKey,
276 on_counterparty_tx_csv: u16,
279 impl Writeable for CounterpartyCommitmentParameters {
280 fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
281 w.write_all(&byte_utils::be64_to_array(0))?;
282 write_tlv_fields!(w, {
283 (0, self.counterparty_delayed_payment_base_key, required),
284 (2, self.counterparty_htlc_base_key, required),
285 (4, self.on_counterparty_tx_csv, required),
290 impl Readable for CounterpartyCommitmentParameters {
291 fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
292 let counterparty_commitment_transaction = {
293 // Versions prior to 0.0.100 had some per-HTLC state stored here, which is no longer
294 // used. Read it for compatibility.
295 let per_htlc_len: u64 = Readable::read(r)?;
296 for _ in 0..per_htlc_len {
297 let _txid: Txid = Readable::read(r)?;
298 let htlcs_count: u64 = Readable::read(r)?;
299 for _ in 0..htlcs_count {
300 let _htlc: HTLCOutputInCommitment = Readable::read(r)?;
304 let mut counterparty_delayed_payment_base_key = OptionDeserWrapper(None);
305 let mut counterparty_htlc_base_key = OptionDeserWrapper(None);
306 let mut on_counterparty_tx_csv: u16 = 0;
307 read_tlv_fields!(r, {
308 (0, counterparty_delayed_payment_base_key, required),
309 (2, counterparty_htlc_base_key, required),
310 (4, on_counterparty_tx_csv, required),
312 CounterpartyCommitmentParameters {
313 counterparty_delayed_payment_base_key: counterparty_delayed_payment_base_key.0.unwrap(),
314 counterparty_htlc_base_key: counterparty_htlc_base_key.0.unwrap(),
315 on_counterparty_tx_csv,
318 Ok(counterparty_commitment_transaction)
322 /// An entry for an [`OnchainEvent`], stating the block height when the event was observed and the
323 /// transaction causing it.
325 /// Used to determine when the on-chain event can be considered safe from a chain reorganization.
327 struct OnchainEventEntry {
333 impl OnchainEventEntry {
334 fn confirmation_threshold(&self) -> u32 {
335 let mut conf_threshold = self.height + ANTI_REORG_DELAY - 1;
337 OnchainEvent::MaturingOutput {
338 descriptor: SpendableOutputDescriptor::DelayedPaymentOutput(ref descriptor)
340 // A CSV'd transaction is confirmable in block (input height) + CSV delay, which means
341 // it's broadcastable when we see the previous block.
342 conf_threshold = cmp::max(conf_threshold, self.height + descriptor.to_self_delay as u32 - 1);
344 OnchainEvent::FundingSpendConfirmation { on_local_output_csv: Some(csv), .. } |
345 OnchainEvent::HTLCSpendConfirmation { on_to_local_output_csv: Some(csv), .. } => {
346 // A CSV'd transaction is confirmable in block (input height) + CSV delay, which means
347 // it's broadcastable when we see the previous block.
348 conf_threshold = cmp::max(conf_threshold, self.height + csv as u32 - 1);
355 fn has_reached_confirmation_threshold(&self, best_block: &BestBlock) -> bool {
356 best_block.height() >= self.confirmation_threshold()
360 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
361 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
364 /// An outbound HTLC failing after a transaction is confirmed. Used
365 /// * when an outbound HTLC output is spent by us after the HTLC timed out
366 /// * an outbound HTLC which was not present in the commitment transaction which appeared
367 /// on-chain (either because it was not fully committed to or it was dust).
368 /// Note that this is *not* used for preimage claims, as those are passed upstream immediately,
369 /// appearing only as an `HTLCSpendConfirmation`, below.
372 payment_hash: PaymentHash,
373 onchain_value_satoshis: Option<u64>,
374 /// None in the second case, above, ie when there is no relevant output in the commitment
375 /// transaction which appeared on chain.
376 input_idx: Option<u32>,
379 descriptor: SpendableOutputDescriptor,
381 /// A spend of the funding output, either a commitment transaction or a cooperative closing
383 FundingSpendConfirmation {
384 /// The CSV delay for the output of the funding spend transaction (implying it is a local
385 /// commitment transaction, and this is the delay on the to_self output).
386 on_local_output_csv: Option<u16>,
388 /// A spend of a commitment transaction HTLC output, set in the cases where *no* `HTLCUpdate`
389 /// is constructed. This is used when
390 /// * an outbound HTLC is claimed by our counterparty with a preimage, causing us to
391 /// immediately claim the HTLC on the inbound edge and track the resolution here,
392 /// * an inbound HTLC is claimed by our counterparty (with a timeout),
393 /// * an inbound HTLC is claimed by us (with a preimage).
394 /// * a revoked-state HTLC transaction was broadcasted, which was claimed by the revocation
396 HTLCSpendConfirmation {
398 /// If the claim was made by either party with a preimage, this is filled in
399 preimage: Option<PaymentPreimage>,
400 /// If the claim was made by us on an inbound HTLC against a local commitment transaction,
401 /// we set this to the output CSV value which we will have to wait until to spend the
402 /// output (and generate a SpendableOutput event).
403 on_to_local_output_csv: Option<u16>,
407 impl Writeable for OnchainEventEntry {
408 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
409 write_tlv_fields!(writer, {
410 (0, self.txid, required),
411 (2, self.height, required),
412 (4, self.event, required),
418 impl MaybeReadable for OnchainEventEntry {
419 fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, DecodeError> {
420 let mut txid = Default::default();
422 let mut event = None;
423 read_tlv_fields!(reader, {
425 (2, height, required),
426 (4, event, ignorable),
428 if let Some(ev) = event {
429 Ok(Some(Self { txid, height, event: ev }))
436 impl_writeable_tlv_based_enum_upgradable!(OnchainEvent,
438 (0, source, required),
439 (1, onchain_value_satoshis, option),
440 (2, payment_hash, required),
441 (3, input_idx, option),
443 (1, MaturingOutput) => {
444 (0, descriptor, required),
446 (3, FundingSpendConfirmation) => {
447 (0, on_local_output_csv, option),
449 (5, HTLCSpendConfirmation) => {
450 (0, input_idx, required),
451 (2, preimage, option),
452 (4, on_to_local_output_csv, option),
457 #[cfg_attr(any(test, feature = "fuzztarget", feature = "_test_utils"), derive(PartialEq))]
459 pub(crate) enum ChannelMonitorUpdateStep {
460 LatestHolderCommitmentTXInfo {
461 commitment_tx: HolderCommitmentTransaction,
462 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
464 LatestCounterpartyCommitmentTXInfo {
465 commitment_txid: Txid,
466 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
467 commitment_number: u64,
468 their_revocation_point: PublicKey,
471 payment_preimage: PaymentPreimage,
477 /// Used to indicate that the no future updates will occur, and likely that the latest holder
478 /// commitment transaction(s) should be broadcast, as the channel has been force-closed.
480 /// If set to false, we shouldn't broadcast the latest holder commitment transaction as we
481 /// think we've fallen behind!
482 should_broadcast: bool,
485 scriptpubkey: Script,
489 impl_writeable_tlv_based_enum_upgradable!(ChannelMonitorUpdateStep,
490 (0, LatestHolderCommitmentTXInfo) => {
491 (0, commitment_tx, required),
492 (2, htlc_outputs, vec_type),
494 (1, LatestCounterpartyCommitmentTXInfo) => {
495 (0, commitment_txid, required),
496 (2, commitment_number, required),
497 (4, their_revocation_point, required),
498 (6, htlc_outputs, vec_type),
500 (2, PaymentPreimage) => {
501 (0, payment_preimage, required),
503 (3, CommitmentSecret) => {
505 (2, secret, required),
507 (4, ChannelForceClosed) => {
508 (0, should_broadcast, required),
510 (5, ShutdownScript) => {
511 (0, scriptpubkey, required),
515 /// Details about the balance(s) available for spending once the channel appears on chain.
517 /// See [`ChannelMonitor::get_claimable_balances`] for more details on when these will or will not
519 #[derive(Clone, Debug, PartialEq, Eq)]
520 #[cfg_attr(test, derive(PartialOrd, Ord))]
522 /// The channel is not yet closed (or the commitment or closing transaction has not yet
523 /// appeared in a block). The given balance is claimable (less on-chain fees) if the channel is
524 /// force-closed now.
525 ClaimableOnChannelClose {
526 /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
527 /// required to do so.
528 claimable_amount_satoshis: u64,
530 /// The channel has been closed, and the given balance is ours but awaiting confirmations until
531 /// we consider it spendable.
532 ClaimableAwaitingConfirmations {
533 /// The amount available to claim, in satoshis, possibly excluding the on-chain fees which
534 /// were spent in broadcasting the transaction.
535 claimable_amount_satoshis: u64,
536 /// The height at which an [`Event::SpendableOutputs`] event will be generated for this
538 confirmation_height: u32,
540 /// The channel has been closed, and the given balance should be ours but awaiting spending
541 /// transaction confirmation. If the spending transaction does not confirm in time, it is
542 /// possible our counterparty can take the funds by broadcasting an HTLC timeout on-chain.
544 /// Once the spending transaction confirms, before it has reached enough confirmations to be
545 /// considered safe from chain reorganizations, the balance will instead be provided via
546 /// [`Balance::ClaimableAwaitingConfirmations`].
547 ContentiousClaimable {
548 /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
549 /// required to do so.
550 claimable_amount_satoshis: u64,
551 /// The height at which the counterparty may be able to claim the balance if we have not
555 /// HTLCs which we sent to our counterparty which are claimable after a timeout (less on-chain
556 /// fees) if the counterparty does not know the preimage for the HTLCs. These are somewhat
557 /// likely to be claimed by our counterparty before we do.
558 MaybeClaimableHTLCAwaitingTimeout {
559 /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
560 /// required to do so.
561 claimable_amount_satoshis: u64,
562 /// The height at which we will be able to claim the balance if our counterparty has not
564 claimable_height: u32,
568 /// An HTLC which has been irrevocably resolved on-chain, and has reached ANTI_REORG_DELAY.
570 struct IrrevocablyResolvedHTLC {
572 /// Only set if the HTLC claim was ours using a payment preimage
573 payment_preimage: Option<PaymentPreimage>,
576 impl_writeable_tlv_based!(IrrevocablyResolvedHTLC, {
577 (0, input_idx, required),
578 (2, payment_preimage, option),
581 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
582 /// on-chain transactions to ensure no loss of funds occurs.
584 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
585 /// information and are actively monitoring the chain.
587 /// Pending Events or updated HTLCs which have not yet been read out by
588 /// get_and_clear_pending_monitor_events or get_and_clear_pending_events are serialized to disk and
589 /// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
590 /// gotten are fully handled before re-serializing the new state.
592 /// Note that the deserializer is only implemented for (BlockHash, ChannelMonitor), which
593 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
594 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
595 /// returned block hash and the the current chain and then reconnecting blocks to get to the
596 /// best chain) upon deserializing the object!
597 pub struct ChannelMonitor<Signer: Sign> {
599 pub(crate) inner: Mutex<ChannelMonitorImpl<Signer>>,
601 inner: Mutex<ChannelMonitorImpl<Signer>>,
604 pub(crate) struct ChannelMonitorImpl<Signer: Sign> {
605 latest_update_id: u64,
606 commitment_transaction_number_obscure_factor: u64,
608 destination_script: Script,
609 broadcasted_holder_revokable_script: Option<(Script, PublicKey, PublicKey)>,
610 counterparty_payment_script: Script,
611 shutdown_script: Option<Script>,
613 channel_keys_id: [u8; 32],
614 holder_revocation_basepoint: PublicKey,
615 funding_info: (OutPoint, Script),
616 current_counterparty_commitment_txid: Option<Txid>,
617 prev_counterparty_commitment_txid: Option<Txid>,
619 counterparty_commitment_params: CounterpartyCommitmentParameters,
620 funding_redeemscript: Script,
621 channel_value_satoshis: u64,
622 // first is the idx of the first of the two revocation points
623 their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
625 on_holder_tx_csv: u16,
627 commitment_secrets: CounterpartyCommitmentSecrets,
628 /// The set of outpoints in each counterparty commitment transaction. We always need at least
629 /// the payment hash from `HTLCOutputInCommitment` to claim even a revoked commitment
630 /// transaction broadcast as we need to be able to construct the witness script in all cases.
631 counterparty_claimable_outpoints: HashMap<Txid, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
632 /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
633 /// Nor can we figure out their commitment numbers without the commitment transaction they are
634 /// spending. Thus, in order to claim them via revocation key, we track all the counterparty
635 /// commitment transactions which we find on-chain, mapping them to the commitment number which
636 /// can be used to derive the revocation key and claim the transactions.
637 counterparty_commitment_txn_on_chain: HashMap<Txid, u64>,
638 /// Cache used to make pruning of payment_preimages faster.
639 /// Maps payment_hash values to commitment numbers for counterparty transactions for non-revoked
640 /// counterparty transactions (ie should remain pretty small).
641 /// Serialized to disk but should generally not be sent to Watchtowers.
642 counterparty_hash_commitment_number: HashMap<PaymentHash, u64>,
644 // We store two holder commitment transactions to avoid any race conditions where we may update
645 // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
646 // various monitors for one channel being out of sync, and us broadcasting a holder
647 // transaction for which we have deleted claim information on some watchtowers.
648 prev_holder_signed_commitment_tx: Option<HolderSignedTx>,
649 current_holder_commitment_tx: HolderSignedTx,
651 // Used just for ChannelManager to make sure it has the latest channel data during
653 current_counterparty_commitment_number: u64,
654 // Used just for ChannelManager to make sure it has the latest channel data during
656 current_holder_commitment_number: u64,
658 payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
660 // Note that `MonitorEvent`s MUST NOT be generated during update processing, only generated
661 // during chain data processing. This prevents a race in `ChainMonitor::update_channel` (and
662 // presumably user implementations thereof as well) where we update the in-memory channel
663 // object, then before the persistence finishes (as it's all under a read-lock), we return
664 // pending events to the user or to the relevant `ChannelManager`. Then, on reload, we'll have
665 // the pre-event state here, but have processed the event in the `ChannelManager`.
666 // Note that because the `event_lock` in `ChainMonitor` is only taken in
667 // block/transaction-connected events and *not* during block/transaction-disconnected events,
668 // we further MUST NOT generate events during block/transaction-disconnection.
669 pending_monitor_events: Vec<MonitorEvent>,
671 pending_events: Vec<Event>,
673 // Used to track on-chain events (i.e., transactions part of channels confirmed on chain) on
674 // which to take actions once they reach enough confirmations. Each entry includes the
675 // transaction's id and the height when the transaction was confirmed on chain.
676 onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
678 // If we get serialized out and re-read, we need to make sure that the chain monitoring
679 // interface knows about the TXOs that we want to be notified of spends of. We could probably
680 // be smart and derive them from the above storage fields, but its much simpler and more
681 // Obviously Correct (tm) if we just keep track of them explicitly.
682 outputs_to_watch: HashMap<Txid, Vec<(u32, Script)>>,
685 pub onchain_tx_handler: OnchainTxHandler<Signer>,
687 onchain_tx_handler: OnchainTxHandler<Signer>,
689 // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
690 // channel has been force-closed. After this is set, no further holder commitment transaction
691 // updates may occur, and we panic!() if one is provided.
692 lockdown_from_offchain: bool,
694 // Set once we've signed a holder commitment transaction and handed it over to our
695 // OnchainTxHandler. After this is set, no future updates to our holder commitment transactions
696 // may occur, and we fail any such monitor updates.
698 // In case of update rejection due to a locally already signed commitment transaction, we
699 // nevertheless store update content to track in case of concurrent broadcast by another
700 // remote monitor out-of-order with regards to the block view.
701 holder_tx_signed: bool,
703 funding_spend_confirmed: Option<Txid>,
704 /// The set of HTLCs which have been either claimed or failed on chain and have reached
705 /// the requisite confirmations on the claim/fail transaction (either ANTI_REORG_DELAY or the
706 /// spending CSV for revocable outputs).
707 htlcs_resolved_on_chain: Vec<IrrevocablyResolvedHTLC>,
709 // We simply modify best_block in Channel's block_connected so that serialization is
710 // consistent but hopefully the users' copy handles block_connected in a consistent way.
711 // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
712 // their best_block from its state and not based on updated copies that didn't run through
713 // the full block_connected).
714 best_block: BestBlock,
716 secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
719 /// Transaction outputs to watch for on-chain spends.
720 pub type TransactionOutputs = (Txid, Vec<(u32, TxOut)>);
722 #[cfg(any(test, feature = "fuzztarget", feature = "_test_utils"))]
723 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
724 /// underlying object
725 impl<Signer: Sign> PartialEq for ChannelMonitor<Signer> {
726 fn eq(&self, other: &Self) -> bool {
727 let inner = self.inner.lock().unwrap();
728 let other = other.inner.lock().unwrap();
733 #[cfg(any(test, feature = "fuzztarget", feature = "_test_utils"))]
734 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
735 /// underlying object
736 impl<Signer: Sign> PartialEq for ChannelMonitorImpl<Signer> {
737 fn eq(&self, other: &Self) -> bool {
738 if self.latest_update_id != other.latest_update_id ||
739 self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
740 self.destination_script != other.destination_script ||
741 self.broadcasted_holder_revokable_script != other.broadcasted_holder_revokable_script ||
742 self.counterparty_payment_script != other.counterparty_payment_script ||
743 self.channel_keys_id != other.channel_keys_id ||
744 self.holder_revocation_basepoint != other.holder_revocation_basepoint ||
745 self.funding_info != other.funding_info ||
746 self.current_counterparty_commitment_txid != other.current_counterparty_commitment_txid ||
747 self.prev_counterparty_commitment_txid != other.prev_counterparty_commitment_txid ||
748 self.counterparty_commitment_params != other.counterparty_commitment_params ||
749 self.funding_redeemscript != other.funding_redeemscript ||
750 self.channel_value_satoshis != other.channel_value_satoshis ||
751 self.their_cur_revocation_points != other.their_cur_revocation_points ||
752 self.on_holder_tx_csv != other.on_holder_tx_csv ||
753 self.commitment_secrets != other.commitment_secrets ||
754 self.counterparty_claimable_outpoints != other.counterparty_claimable_outpoints ||
755 self.counterparty_commitment_txn_on_chain != other.counterparty_commitment_txn_on_chain ||
756 self.counterparty_hash_commitment_number != other.counterparty_hash_commitment_number ||
757 self.prev_holder_signed_commitment_tx != other.prev_holder_signed_commitment_tx ||
758 self.current_counterparty_commitment_number != other.current_counterparty_commitment_number ||
759 self.current_holder_commitment_number != other.current_holder_commitment_number ||
760 self.current_holder_commitment_tx != other.current_holder_commitment_tx ||
761 self.payment_preimages != other.payment_preimages ||
762 self.pending_monitor_events != other.pending_monitor_events ||
763 self.pending_events.len() != other.pending_events.len() || // We trust events to round-trip properly
764 self.onchain_events_awaiting_threshold_conf != other.onchain_events_awaiting_threshold_conf ||
765 self.outputs_to_watch != other.outputs_to_watch ||
766 self.lockdown_from_offchain != other.lockdown_from_offchain ||
767 self.holder_tx_signed != other.holder_tx_signed ||
768 self.funding_spend_confirmed != other.funding_spend_confirmed ||
769 self.htlcs_resolved_on_chain != other.htlcs_resolved_on_chain
778 impl<Signer: Sign> Writeable for ChannelMonitor<Signer> {
779 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
780 self.inner.lock().unwrap().write(writer)
784 // These are also used for ChannelMonitorUpdate, above.
785 const SERIALIZATION_VERSION: u8 = 1;
786 const MIN_SERIALIZATION_VERSION: u8 = 1;
788 impl<Signer: Sign> Writeable for ChannelMonitorImpl<Signer> {
789 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
790 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
792 self.latest_update_id.write(writer)?;
794 // Set in initial Channel-object creation, so should always be set by now:
795 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
797 self.destination_script.write(writer)?;
798 if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
799 writer.write_all(&[0; 1])?;
800 broadcasted_holder_revokable_script.0.write(writer)?;
801 broadcasted_holder_revokable_script.1.write(writer)?;
802 broadcasted_holder_revokable_script.2.write(writer)?;
804 writer.write_all(&[1; 1])?;
807 self.counterparty_payment_script.write(writer)?;
808 match &self.shutdown_script {
809 Some(script) => script.write(writer)?,
810 None => Script::new().write(writer)?,
813 self.channel_keys_id.write(writer)?;
814 self.holder_revocation_basepoint.write(writer)?;
815 writer.write_all(&self.funding_info.0.txid[..])?;
816 writer.write_all(&byte_utils::be16_to_array(self.funding_info.0.index))?;
817 self.funding_info.1.write(writer)?;
818 self.current_counterparty_commitment_txid.write(writer)?;
819 self.prev_counterparty_commitment_txid.write(writer)?;
821 self.counterparty_commitment_params.write(writer)?;
822 self.funding_redeemscript.write(writer)?;
823 self.channel_value_satoshis.write(writer)?;
825 match self.their_cur_revocation_points {
826 Some((idx, pubkey, second_option)) => {
827 writer.write_all(&byte_utils::be48_to_array(idx))?;
828 writer.write_all(&pubkey.serialize())?;
829 match second_option {
830 Some(second_pubkey) => {
831 writer.write_all(&second_pubkey.serialize())?;
834 writer.write_all(&[0; 33])?;
839 writer.write_all(&byte_utils::be48_to_array(0))?;
843 writer.write_all(&byte_utils::be16_to_array(self.on_holder_tx_csv))?;
845 self.commitment_secrets.write(writer)?;
847 macro_rules! serialize_htlc_in_commitment {
848 ($htlc_output: expr) => {
849 writer.write_all(&[$htlc_output.offered as u8; 1])?;
850 writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?;
851 writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?;
852 writer.write_all(&$htlc_output.payment_hash.0[..])?;
853 $htlc_output.transaction_output_index.write(writer)?;
857 writer.write_all(&byte_utils::be64_to_array(self.counterparty_claimable_outpoints.len() as u64))?;
858 for (ref txid, ref htlc_infos) in self.counterparty_claimable_outpoints.iter() {
859 writer.write_all(&txid[..])?;
860 writer.write_all(&byte_utils::be64_to_array(htlc_infos.len() as u64))?;
861 for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
862 serialize_htlc_in_commitment!(htlc_output);
863 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
867 writer.write_all(&byte_utils::be64_to_array(self.counterparty_commitment_txn_on_chain.len() as u64))?;
868 for (ref txid, commitment_number) in self.counterparty_commitment_txn_on_chain.iter() {
869 writer.write_all(&txid[..])?;
870 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
873 writer.write_all(&byte_utils::be64_to_array(self.counterparty_hash_commitment_number.len() as u64))?;
874 for (ref payment_hash, commitment_number) in self.counterparty_hash_commitment_number.iter() {
875 writer.write_all(&payment_hash.0[..])?;
876 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
879 if let Some(ref prev_holder_tx) = self.prev_holder_signed_commitment_tx {
880 writer.write_all(&[1; 1])?;
881 prev_holder_tx.write(writer)?;
883 writer.write_all(&[0; 1])?;
886 self.current_holder_commitment_tx.write(writer)?;
888 writer.write_all(&byte_utils::be48_to_array(self.current_counterparty_commitment_number))?;
889 writer.write_all(&byte_utils::be48_to_array(self.current_holder_commitment_number))?;
891 writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
892 for payment_preimage in self.payment_preimages.values() {
893 writer.write_all(&payment_preimage.0[..])?;
896 writer.write_all(&(self.pending_monitor_events.iter().filter(|ev| match ev {
897 MonitorEvent::HTLCEvent(_) => true,
898 MonitorEvent::CommitmentTxConfirmed(_) => true,
900 }).count() as u64).to_be_bytes())?;
901 for event in self.pending_monitor_events.iter() {
903 MonitorEvent::HTLCEvent(upd) => {
907 MonitorEvent::CommitmentTxConfirmed(_) => 1u8.write(writer)?,
908 _ => {}, // Covered in the TLV writes below
912 writer.write_all(&byte_utils::be64_to_array(self.pending_events.len() as u64))?;
913 for event in self.pending_events.iter() {
914 event.write(writer)?;
917 self.best_block.block_hash().write(writer)?;
918 writer.write_all(&byte_utils::be32_to_array(self.best_block.height()))?;
920 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_awaiting_threshold_conf.len() as u64))?;
921 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
922 entry.write(writer)?;
925 (self.outputs_to_watch.len() as u64).write(writer)?;
926 for (txid, idx_scripts) in self.outputs_to_watch.iter() {
928 (idx_scripts.len() as u64).write(writer)?;
929 for (idx, script) in idx_scripts.iter() {
931 script.write(writer)?;
934 self.onchain_tx_handler.write(writer)?;
936 self.lockdown_from_offchain.write(writer)?;
937 self.holder_tx_signed.write(writer)?;
939 write_tlv_fields!(writer, {
940 (1, self.funding_spend_confirmed, option),
941 (3, self.htlcs_resolved_on_chain, vec_type),
942 (5, self.pending_monitor_events, vec_type),
949 impl<Signer: Sign> ChannelMonitor<Signer> {
950 pub(crate) fn new(secp_ctx: Secp256k1<secp256k1::All>, keys: Signer, shutdown_script: Option<Script>,
951 on_counterparty_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
952 channel_parameters: &ChannelTransactionParameters,
953 funding_redeemscript: Script, channel_value_satoshis: u64,
954 commitment_transaction_number_obscure_factor: u64,
955 initial_holder_commitment_tx: HolderCommitmentTransaction,
956 best_block: BestBlock) -> ChannelMonitor<Signer> {
958 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
959 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
960 let counterparty_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
962 let counterparty_channel_parameters = channel_parameters.counterparty_parameters.as_ref().unwrap();
963 let counterparty_delayed_payment_base_key = counterparty_channel_parameters.pubkeys.delayed_payment_basepoint;
964 let counterparty_htlc_base_key = counterparty_channel_parameters.pubkeys.htlc_basepoint;
965 let counterparty_commitment_params = CounterpartyCommitmentParameters { counterparty_delayed_payment_base_key, counterparty_htlc_base_key, on_counterparty_tx_csv };
967 let channel_keys_id = keys.channel_keys_id();
968 let holder_revocation_basepoint = keys.pubkeys().revocation_basepoint;
970 // block for Rust 1.34 compat
971 let (holder_commitment_tx, current_holder_commitment_number) = {
972 let trusted_tx = initial_holder_commitment_tx.trust();
973 let txid = trusted_tx.txid();
975 let tx_keys = trusted_tx.keys();
976 let holder_commitment_tx = HolderSignedTx {
978 revocation_key: tx_keys.revocation_key,
979 a_htlc_key: tx_keys.broadcaster_htlc_key,
980 b_htlc_key: tx_keys.countersignatory_htlc_key,
981 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
982 per_commitment_point: tx_keys.per_commitment_point,
983 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
984 to_self_value_sat: initial_holder_commitment_tx.to_broadcaster_value_sat(),
985 feerate_per_kw: trusted_tx.feerate_per_kw(),
987 (holder_commitment_tx, trusted_tx.commitment_number())
990 let onchain_tx_handler =
991 OnchainTxHandler::new(destination_script.clone(), keys,
992 channel_parameters.clone(), initial_holder_commitment_tx, secp_ctx.clone());
994 let mut outputs_to_watch = HashMap::new();
995 outputs_to_watch.insert(funding_info.0.txid, vec![(funding_info.0.index as u32, funding_info.1.clone())]);
998 inner: Mutex::new(ChannelMonitorImpl {
1000 commitment_transaction_number_obscure_factor,
1002 destination_script: destination_script.clone(),
1003 broadcasted_holder_revokable_script: None,
1004 counterparty_payment_script,
1008 holder_revocation_basepoint,
1010 current_counterparty_commitment_txid: None,
1011 prev_counterparty_commitment_txid: None,
1013 counterparty_commitment_params,
1014 funding_redeemscript,
1015 channel_value_satoshis,
1016 their_cur_revocation_points: None,
1018 on_holder_tx_csv: counterparty_channel_parameters.selected_contest_delay,
1020 commitment_secrets: CounterpartyCommitmentSecrets::new(),
1021 counterparty_claimable_outpoints: HashMap::new(),
1022 counterparty_commitment_txn_on_chain: HashMap::new(),
1023 counterparty_hash_commitment_number: HashMap::new(),
1025 prev_holder_signed_commitment_tx: None,
1026 current_holder_commitment_tx: holder_commitment_tx,
1027 current_counterparty_commitment_number: 1 << 48,
1028 current_holder_commitment_number,
1030 payment_preimages: HashMap::new(),
1031 pending_monitor_events: Vec::new(),
1032 pending_events: Vec::new(),
1034 onchain_events_awaiting_threshold_conf: Vec::new(),
1039 lockdown_from_offchain: false,
1040 holder_tx_signed: false,
1041 funding_spend_confirmed: None,
1042 htlcs_resolved_on_chain: Vec::new(),
1052 fn provide_secret(&self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
1053 self.inner.lock().unwrap().provide_secret(idx, secret)
1056 /// Informs this monitor of the latest counterparty (ie non-broadcastable) commitment transaction.
1057 /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1058 /// possibly future revocation/preimage information) to claim outputs where possible.
1059 /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1060 pub(crate) fn provide_latest_counterparty_commitment_tx<L: Deref>(
1063 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
1064 commitment_number: u64,
1065 their_revocation_point: PublicKey,
1067 ) where L::Target: Logger {
1068 self.inner.lock().unwrap().provide_latest_counterparty_commitment_tx(
1069 txid, htlc_outputs, commitment_number, their_revocation_point, logger)
1073 fn provide_latest_holder_commitment_tx(
1075 holder_commitment_tx: HolderCommitmentTransaction,
1076 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
1077 ) -> Result<(), MonitorUpdateError> {
1078 self.inner.lock().unwrap().provide_latest_holder_commitment_tx(
1079 holder_commitment_tx, htlc_outputs)
1083 pub(crate) fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(
1085 payment_hash: &PaymentHash,
1086 payment_preimage: &PaymentPreimage,
1091 B::Target: BroadcasterInterface,
1092 F::Target: FeeEstimator,
1095 self.inner.lock().unwrap().provide_payment_preimage(
1096 payment_hash, payment_preimage, broadcaster, fee_estimator, logger)
1099 pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(
1104 B::Target: BroadcasterInterface,
1107 self.inner.lock().unwrap().broadcast_latest_holder_commitment_txn(broadcaster, logger)
1110 /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1113 /// panics if the given update is not the next update by update_id.
1114 pub fn update_monitor<B: Deref, F: Deref, L: Deref>(
1116 updates: &ChannelMonitorUpdate,
1120 ) -> Result<(), MonitorUpdateError>
1122 B::Target: BroadcasterInterface,
1123 F::Target: FeeEstimator,
1126 self.inner.lock().unwrap().update_monitor(updates, broadcaster, fee_estimator, logger)
1129 /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1131 pub fn get_latest_update_id(&self) -> u64 {
1132 self.inner.lock().unwrap().get_latest_update_id()
1135 /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1136 pub fn get_funding_txo(&self) -> (OutPoint, Script) {
1137 self.inner.lock().unwrap().get_funding_txo().clone()
1140 /// Gets a list of txids, with their output scripts (in the order they appear in the
1141 /// transaction), which we must learn about spends of via block_connected().
1142 pub fn get_outputs_to_watch(&self) -> Vec<(Txid, Vec<(u32, Script)>)> {
1143 self.inner.lock().unwrap().get_outputs_to_watch()
1144 .iter().map(|(txid, outputs)| (*txid, outputs.clone())).collect()
1147 /// Loads the funding txo and outputs to watch into the given `chain::Filter` by repeatedly
1148 /// calling `chain::Filter::register_output` and `chain::Filter::register_tx` until all outputs
1149 /// have been registered.
1150 pub fn load_outputs_to_watch<F: Deref>(&self, filter: &F) where F::Target: chain::Filter {
1151 let lock = self.inner.lock().unwrap();
1152 filter.register_tx(&lock.get_funding_txo().0.txid, &lock.get_funding_txo().1);
1153 for (txid, outputs) in lock.get_outputs_to_watch().iter() {
1154 for (index, script_pubkey) in outputs.iter() {
1155 assert!(*index <= u16::max_value() as u32);
1156 filter.register_output(WatchedOutput {
1158 outpoint: OutPoint { txid: *txid, index: *index as u16 },
1159 script_pubkey: script_pubkey.clone(),
1165 /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1166 /// ChannelManager via [`chain::Watch::release_pending_monitor_events`].
1167 pub fn get_and_clear_pending_monitor_events(&self) -> Vec<MonitorEvent> {
1168 self.inner.lock().unwrap().get_and_clear_pending_monitor_events()
1171 /// Gets the list of pending events which were generated by previous actions, clearing the list
1174 /// This is called by ChainMonitor::get_and_clear_pending_events() and is equivalent to
1175 /// EventsProvider::get_and_clear_pending_events() except that it requires &mut self as we do
1176 /// no internal locking in ChannelMonitors.
1177 pub fn get_and_clear_pending_events(&self) -> Vec<Event> {
1178 self.inner.lock().unwrap().get_and_clear_pending_events()
1181 pub(crate) fn get_min_seen_secret(&self) -> u64 {
1182 self.inner.lock().unwrap().get_min_seen_secret()
1185 pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1186 self.inner.lock().unwrap().get_cur_counterparty_commitment_number()
1189 pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
1190 self.inner.lock().unwrap().get_cur_holder_commitment_number()
1193 /// Used by ChannelManager deserialization to broadcast the latest holder state if its copy of
1194 /// the Channel was out-of-date. You may use it to get a broadcastable holder toxic tx in case of
1195 /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our counterparty side knows
1196 /// a higher revocation secret than the holder commitment number we are aware of. Broadcasting these
1197 /// transactions are UNSAFE, as they allow counterparty side to punish you. Nevertheless you may want to
1198 /// broadcast them if counterparty don't close channel with his higher commitment transaction after a
1199 /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
1200 /// out-of-band the other node operator to coordinate with him if option is available to you.
1201 /// In any-case, choice is up to the user.
1202 pub fn get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1203 where L::Target: Logger {
1204 self.inner.lock().unwrap().get_latest_holder_commitment_txn(logger)
1207 /// Unsafe test-only version of get_latest_holder_commitment_txn used by our test framework
1208 /// to bypass HolderCommitmentTransaction state update lockdown after signature and generate
1209 /// revoked commitment transaction.
1210 #[cfg(any(test, feature = "unsafe_revoked_tx_signing"))]
1211 pub fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1212 where L::Target: Logger {
1213 self.inner.lock().unwrap().unsafe_get_latest_holder_commitment_txn(logger)
1216 /// Processes transactions in a newly connected block, which may result in any of the following:
1217 /// - update the monitor's state against resolved HTLCs
1218 /// - punish the counterparty in the case of seeing a revoked commitment transaction
1219 /// - force close the channel and claim/timeout incoming/outgoing HTLCs if near expiration
1220 /// - detect settled outputs for later spending
1221 /// - schedule and bump any in-flight claims
1223 /// Returns any new outputs to watch from `txdata`; after called, these are also included in
1224 /// [`get_outputs_to_watch`].
1226 /// [`get_outputs_to_watch`]: #method.get_outputs_to_watch
1227 pub fn block_connected<B: Deref, F: Deref, L: Deref>(
1229 header: &BlockHeader,
1230 txdata: &TransactionData,
1235 ) -> Vec<TransactionOutputs>
1237 B::Target: BroadcasterInterface,
1238 F::Target: FeeEstimator,
1241 self.inner.lock().unwrap().block_connected(
1242 header, txdata, height, broadcaster, fee_estimator, logger)
1245 /// Determines if the disconnected block contained any transactions of interest and updates
1247 pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(
1249 header: &BlockHeader,
1255 B::Target: BroadcasterInterface,
1256 F::Target: FeeEstimator,
1259 self.inner.lock().unwrap().block_disconnected(
1260 header, height, broadcaster, fee_estimator, logger)
1263 /// Processes transactions confirmed in a block with the given header and height, returning new
1264 /// outputs to watch. See [`block_connected`] for details.
1266 /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
1267 /// blocks. See [`chain::Confirm`] for calling expectations.
1269 /// [`block_connected`]: Self::block_connected
1270 pub fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
1272 header: &BlockHeader,
1273 txdata: &TransactionData,
1278 ) -> Vec<TransactionOutputs>
1280 B::Target: BroadcasterInterface,
1281 F::Target: FeeEstimator,
1284 self.inner.lock().unwrap().transactions_confirmed(
1285 header, txdata, height, broadcaster, fee_estimator, logger)
1288 /// Processes a transaction that was reorganized out of the chain.
1290 /// Used instead of [`block_disconnected`] by clients that are notified of transactions rather
1291 /// than blocks. See [`chain::Confirm`] for calling expectations.
1293 /// [`block_disconnected`]: Self::block_disconnected
1294 pub fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
1301 B::Target: BroadcasterInterface,
1302 F::Target: FeeEstimator,
1305 self.inner.lock().unwrap().transaction_unconfirmed(
1306 txid, broadcaster, fee_estimator, logger);
1309 /// Updates the monitor with the current best chain tip, returning new outputs to watch. See
1310 /// [`block_connected`] for details.
1312 /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
1313 /// blocks. See [`chain::Confirm`] for calling expectations.
1315 /// [`block_connected`]: Self::block_connected
1316 pub fn best_block_updated<B: Deref, F: Deref, L: Deref>(
1318 header: &BlockHeader,
1323 ) -> Vec<TransactionOutputs>
1325 B::Target: BroadcasterInterface,
1326 F::Target: FeeEstimator,
1329 self.inner.lock().unwrap().best_block_updated(
1330 header, height, broadcaster, fee_estimator, logger)
1333 /// Returns the set of txids that should be monitored for re-organization out of the chain.
1334 pub fn get_relevant_txids(&self) -> Vec<Txid> {
1335 let inner = self.inner.lock().unwrap();
1336 let mut txids: Vec<Txid> = inner.onchain_events_awaiting_threshold_conf
1338 .map(|entry| entry.txid)
1339 .chain(inner.onchain_tx_handler.get_relevant_txids().into_iter())
1341 txids.sort_unstable();
1346 /// Gets the latest best block which was connected either via the [`chain::Listen`] or
1347 /// [`chain::Confirm`] interfaces.
1348 pub fn current_best_block(&self) -> BestBlock {
1349 self.inner.lock().unwrap().best_block.clone()
1352 /// Gets the balances in this channel which are either claimable by us if we were to
1353 /// force-close the channel now or which are claimable on-chain (possibly awaiting
1356 /// Any balances in the channel which are available on-chain (excluding on-chain fees) are
1357 /// included here until an [`Event::SpendableOutputs`] event has been generated for the
1358 /// balance, or until our counterparty has claimed the balance and accrued several
1359 /// confirmations on the claim transaction.
1361 /// Note that the balances available when you or your counterparty have broadcasted revoked
1362 /// state(s) may not be fully captured here.
1365 /// See [`Balance`] for additional details on the types of claimable balances which
1366 /// may be returned here and their meanings.
1367 pub fn get_claimable_balances(&self) -> Vec<Balance> {
1368 let mut res = Vec::new();
1369 let us = self.inner.lock().unwrap();
1371 let mut confirmed_txid = us.funding_spend_confirmed;
1372 let mut pending_commitment_tx_conf_thresh = None;
1373 let funding_spend_pending = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1374 if let OnchainEvent::FundingSpendConfirmation { .. } = event.event {
1375 Some((event.txid, event.confirmation_threshold()))
1378 if let Some((txid, conf_thresh)) = funding_spend_pending {
1379 debug_assert!(us.funding_spend_confirmed.is_none(),
1380 "We have a pending funding spend awaiting anti-reorg confirmation, we can't have confirmed it already!");
1381 confirmed_txid = Some(txid);
1382 pending_commitment_tx_conf_thresh = Some(conf_thresh);
1385 macro_rules! walk_htlcs {
1386 ($holder_commitment: expr, $htlc_iter: expr) => {
1387 for htlc in $htlc_iter {
1388 if let Some(htlc_input_idx) = htlc.transaction_output_index {
1389 if us.htlcs_resolved_on_chain.iter().any(|v| v.input_idx == htlc_input_idx) {
1390 assert!(us.funding_spend_confirmed.is_some());
1391 } else if htlc.offered == $holder_commitment {
1392 // If the payment was outbound, check if there's an HTLCUpdate
1393 // indicating we have spent this HTLC with a timeout, claiming it back
1394 // and awaiting confirmations on it.
1395 let htlc_update_pending = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1396 if let OnchainEvent::HTLCUpdate { input_idx: Some(input_idx), .. } = event.event {
1397 if input_idx == htlc_input_idx { Some(event.confirmation_threshold()) } else { None }
1400 if let Some(conf_thresh) = htlc_update_pending {
1401 res.push(Balance::ClaimableAwaitingConfirmations {
1402 claimable_amount_satoshis: htlc.amount_msat / 1000,
1403 confirmation_height: conf_thresh,
1406 res.push(Balance::MaybeClaimableHTLCAwaitingTimeout {
1407 claimable_amount_satoshis: htlc.amount_msat / 1000,
1408 claimable_height: htlc.cltv_expiry,
1411 } else if us.payment_preimages.get(&htlc.payment_hash).is_some() {
1412 // Otherwise (the payment was inbound), only expose it as claimable if
1413 // we know the preimage.
1414 // Note that if there is a pending claim, but it did not use the
1415 // preimage, we lost funds to our counterparty! We will then continue
1416 // to show it as ContentiousClaimable until ANTI_REORG_DELAY.
1417 let htlc_spend_pending = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1418 if let OnchainEvent::HTLCSpendConfirmation { input_idx, preimage, .. } = event.event {
1419 if input_idx == htlc_input_idx {
1420 Some((event.confirmation_threshold(), preimage.is_some()))
1424 if let Some((conf_thresh, true)) = htlc_spend_pending {
1425 res.push(Balance::ClaimableAwaitingConfirmations {
1426 claimable_amount_satoshis: htlc.amount_msat / 1000,
1427 confirmation_height: conf_thresh,
1430 res.push(Balance::ContentiousClaimable {
1431 claimable_amount_satoshis: htlc.amount_msat / 1000,
1432 timeout_height: htlc.cltv_expiry,
1441 if let Some(txid) = confirmed_txid {
1442 let mut found_commitment_tx = false;
1443 if Some(txid) == us.current_counterparty_commitment_txid || Some(txid) == us.prev_counterparty_commitment_txid {
1444 walk_htlcs!(false, us.counterparty_claimable_outpoints.get(&txid).unwrap().iter().map(|(a, _)| a));
1445 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1446 if let Some(value) = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1447 if let OnchainEvent::MaturingOutput {
1448 descriptor: SpendableOutputDescriptor::StaticPaymentOutput(descriptor)
1450 Some(descriptor.output.value)
1453 res.push(Balance::ClaimableAwaitingConfirmations {
1454 claimable_amount_satoshis: value,
1455 confirmation_height: conf_thresh,
1458 // If a counterparty commitment transaction is awaiting confirmation, we
1459 // should either have a StaticPaymentOutput MaturingOutput event awaiting
1460 // confirmation with the same height or have never met our dust amount.
1463 found_commitment_tx = true;
1464 } else if txid == us.current_holder_commitment_tx.txid {
1465 walk_htlcs!(true, us.current_holder_commitment_tx.htlc_outputs.iter().map(|(a, _, _)| a));
1466 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1467 res.push(Balance::ClaimableAwaitingConfirmations {
1468 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
1469 confirmation_height: conf_thresh,
1472 found_commitment_tx = true;
1473 } else if let Some(prev_commitment) = &us.prev_holder_signed_commitment_tx {
1474 if txid == prev_commitment.txid {
1475 walk_htlcs!(true, prev_commitment.htlc_outputs.iter().map(|(a, _, _)| a));
1476 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1477 res.push(Balance::ClaimableAwaitingConfirmations {
1478 claimable_amount_satoshis: prev_commitment.to_self_value_sat,
1479 confirmation_height: conf_thresh,
1482 found_commitment_tx = true;
1485 if !found_commitment_tx {
1486 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1487 // We blindly assume this is a cooperative close transaction here, and that
1488 // neither us nor our counterparty misbehaved. At worst we've under-estimated
1489 // the amount we can claim as we'll punish a misbehaving counterparty.
1490 res.push(Balance::ClaimableAwaitingConfirmations {
1491 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
1492 confirmation_height: conf_thresh,
1496 // TODO: Add logic to provide claimable balances for counterparty broadcasting revoked
1499 let mut claimable_inbound_htlc_value_sat = 0;
1500 for (htlc, _, _) in us.current_holder_commitment_tx.htlc_outputs.iter() {
1501 if htlc.transaction_output_index.is_none() { continue; }
1503 res.push(Balance::MaybeClaimableHTLCAwaitingTimeout {
1504 claimable_amount_satoshis: htlc.amount_msat / 1000,
1505 claimable_height: htlc.cltv_expiry,
1507 } else if us.payment_preimages.get(&htlc.payment_hash).is_some() {
1508 claimable_inbound_htlc_value_sat += htlc.amount_msat / 1000;
1511 res.push(Balance::ClaimableOnChannelClose {
1512 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat + claimable_inbound_htlc_value_sat,
1519 /// Gets the set of outbound HTLCs which are pending resolution in this channel.
1520 /// This is used to reconstruct pending outbound payments on restart in the ChannelManager.
1521 pub(crate) fn get_pending_outbound_htlcs(&self) -> HashMap<HTLCSource, HTLCOutputInCommitment> {
1522 let mut res = HashMap::new();
1523 let us = self.inner.lock().unwrap();
1525 macro_rules! walk_htlcs {
1526 ($holder_commitment: expr, $htlc_iter: expr) => {
1527 for (htlc, source) in $htlc_iter {
1528 if us.htlcs_resolved_on_chain.iter().any(|v| Some(v.input_idx) == htlc.transaction_output_index) {
1529 // We should assert that funding_spend_confirmed is_some() here, but we
1530 // have some unit tests which violate HTLC transaction CSVs entirely and
1532 // TODO: Once tests all connect transactions at consensus-valid times, we
1533 // should assert here like we do in `get_claimable_balances`.
1534 } else if htlc.offered == $holder_commitment {
1535 // If the payment was outbound, check if there's an HTLCUpdate
1536 // indicating we have spent this HTLC with a timeout, claiming it back
1537 // and awaiting confirmations on it.
1538 let htlc_update_confd = us.onchain_events_awaiting_threshold_conf.iter().any(|event| {
1539 if let OnchainEvent::HTLCUpdate { input_idx: Some(input_idx), .. } = event.event {
1540 // If the HTLC was timed out, we wait for ANTI_REORG_DELAY blocks
1541 // before considering it "no longer pending" - this matches when we
1542 // provide the ChannelManager an HTLC failure event.
1543 Some(input_idx) == htlc.transaction_output_index &&
1544 us.best_block.height() >= event.height + ANTI_REORG_DELAY - 1
1545 } else if let OnchainEvent::HTLCSpendConfirmation { input_idx, .. } = event.event {
1546 // If the HTLC was fulfilled with a preimage, we consider the HTLC
1547 // immediately non-pending, matching when we provide ChannelManager
1549 Some(input_idx) == htlc.transaction_output_index
1552 if !htlc_update_confd {
1553 res.insert(source.clone(), htlc.clone());
1560 // We're only concerned with the confirmation count of HTLC transactions, and don't
1561 // actually care how many confirmations a commitment transaction may or may not have. Thus,
1562 // we look for either a FundingSpendConfirmation event or a funding_spend_confirmed.
1563 let confirmed_txid = us.funding_spend_confirmed.or_else(|| {
1564 us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1565 if let OnchainEvent::FundingSpendConfirmation { .. } = event.event {
1570 if let Some(txid) = confirmed_txid {
1571 if Some(txid) == us.current_counterparty_commitment_txid || Some(txid) == us.prev_counterparty_commitment_txid {
1572 walk_htlcs!(false, us.counterparty_claimable_outpoints.get(&txid).unwrap().iter().filter_map(|(a, b)| {
1573 if let &Some(ref source) = b {
1574 Some((a, &**source))
1577 } else if txid == us.current_holder_commitment_tx.txid {
1578 walk_htlcs!(true, us.current_holder_commitment_tx.htlc_outputs.iter().filter_map(|(a, _, c)| {
1579 if let Some(source) = c { Some((a, source)) } else { None }
1581 } else if let Some(prev_commitment) = &us.prev_holder_signed_commitment_tx {
1582 if txid == prev_commitment.txid {
1583 walk_htlcs!(true, prev_commitment.htlc_outputs.iter().filter_map(|(a, _, c)| {
1584 if let Some(source) = c { Some((a, source)) } else { None }
1589 // If we have not seen a commitment transaction on-chain (ie the channel is not yet
1590 // closed), just examine the available counterparty commitment transactions. See docs
1591 // on `fail_unbroadcast_htlcs`, below, for justification.
1592 macro_rules! walk_counterparty_commitment {
1594 if let Some(ref latest_outpoints) = us.counterparty_claimable_outpoints.get($txid) {
1595 for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1596 if let &Some(ref source) = source_option {
1597 res.insert((**source).clone(), htlc.clone());
1603 if let Some(ref txid) = us.current_counterparty_commitment_txid {
1604 walk_counterparty_commitment!(txid);
1606 if let Some(ref txid) = us.prev_counterparty_commitment_txid {
1607 walk_counterparty_commitment!(txid);
1615 /// Compares a broadcasted commitment transaction's HTLCs with those in the latest state,
1616 /// failing any HTLCs which didn't make it into the broadcasted commitment transaction back
1617 /// after ANTI_REORG_DELAY blocks.
1619 /// We always compare against the set of HTLCs in counterparty commitment transactions, as those
1620 /// are the commitment transactions which are generated by us. The off-chain state machine in
1621 /// `Channel` will automatically resolve any HTLCs which were never included in a commitment
1622 /// transaction when it detects channel closure, but it is up to us to ensure any HTLCs which were
1623 /// included in a remote commitment transaction are failed back if they are not present in the
1624 /// broadcasted commitment transaction.
1626 /// Specifically, the removal process for HTLCs in `Channel` is always based on the counterparty
1627 /// sending a `revoke_and_ack`, which causes us to clear `prev_counterparty_commitment_txid`. Thus,
1628 /// as long as we examine both the current counterparty commitment transaction and, if it hasn't
1629 /// been revoked yet, the previous one, we we will never "forget" to resolve an HTLC.
1630 macro_rules! fail_unbroadcast_htlcs {
1631 ($self: expr, $commitment_tx_type: expr, $commitment_tx_conf_height: expr, $confirmed_htlcs_list: expr, $logger: expr) => { {
1632 macro_rules! check_htlc_fails {
1633 ($txid: expr, $commitment_tx: expr) => {
1634 if let Some(ref latest_outpoints) = $self.counterparty_claimable_outpoints.get($txid) {
1635 for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1636 if let &Some(ref source) = source_option {
1637 // Check if the HTLC is present in the commitment transaction that was
1638 // broadcast, but not if it was below the dust limit, which we should
1639 // fail backwards immediately as there is no way for us to learn the
1640 // payment_preimage.
1641 // Note that if the dust limit were allowed to change between
1642 // commitment transactions we'd want to be check whether *any*
1643 // broadcastable commitment transaction has the HTLC in it, but it
1644 // cannot currently change after channel initialization, so we don't
1646 let confirmed_htlcs_iter: &mut Iterator<Item = (&HTLCOutputInCommitment, Option<&HTLCSource>)> = &mut $confirmed_htlcs_list;
1647 let mut matched_htlc = false;
1648 for (ref broadcast_htlc, ref broadcast_source) in confirmed_htlcs_iter {
1649 if broadcast_htlc.transaction_output_index.is_some() && Some(&**source) == *broadcast_source {
1650 matched_htlc = true;
1654 if matched_htlc { continue; }
1655 $self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
1656 if entry.height != $commitment_tx_conf_height { return true; }
1658 OnchainEvent::HTLCUpdate { source: ref update_source, .. } => {
1659 *update_source != **source
1664 let entry = OnchainEventEntry {
1666 height: $commitment_tx_conf_height,
1667 event: OnchainEvent::HTLCUpdate {
1668 source: (**source).clone(),
1669 payment_hash: htlc.payment_hash.clone(),
1670 onchain_value_satoshis: Some(htlc.amount_msat / 1000),
1674 log_trace!($logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of {} commitment transaction, waiting for confirmation (at height {})",
1675 log_bytes!(htlc.payment_hash.0), $commitment_tx, $commitment_tx_type, entry.confirmation_threshold());
1676 $self.onchain_events_awaiting_threshold_conf.push(entry);
1682 if let Some(ref txid) = $self.current_counterparty_commitment_txid {
1683 check_htlc_fails!(txid, "current");
1685 if let Some(ref txid) = $self.prev_counterparty_commitment_txid {
1686 check_htlc_fails!(txid, "previous");
1691 impl<Signer: Sign> ChannelMonitorImpl<Signer> {
1692 /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
1693 /// needed by holder commitment transactions HTCLs nor by counterparty ones. Unless we haven't already seen
1694 /// counterparty commitment transaction's secret, they are de facto pruned (we can use revocation key).
1695 fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
1696 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
1697 return Err(MonitorUpdateError("Previous secret did not match new one"));
1700 // Prune HTLCs from the previous counterparty commitment tx so we don't generate failure/fulfill
1701 // events for now-revoked/fulfilled HTLCs.
1702 if let Some(txid) = self.prev_counterparty_commitment_txid.take() {
1703 for &mut (_, ref mut source) in self.counterparty_claimable_outpoints.get_mut(&txid).unwrap() {
1708 if !self.payment_preimages.is_empty() {
1709 let cur_holder_signed_commitment_tx = &self.current_holder_commitment_tx;
1710 let prev_holder_signed_commitment_tx = self.prev_holder_signed_commitment_tx.as_ref();
1711 let min_idx = self.get_min_seen_secret();
1712 let counterparty_hash_commitment_number = &mut self.counterparty_hash_commitment_number;
1714 self.payment_preimages.retain(|&k, _| {
1715 for &(ref htlc, _, _) in cur_holder_signed_commitment_tx.htlc_outputs.iter() {
1716 if k == htlc.payment_hash {
1720 if let Some(prev_holder_commitment_tx) = prev_holder_signed_commitment_tx {
1721 for &(ref htlc, _, _) in prev_holder_commitment_tx.htlc_outputs.iter() {
1722 if k == htlc.payment_hash {
1727 let contains = if let Some(cn) = counterparty_hash_commitment_number.get(&k) {
1734 counterparty_hash_commitment_number.remove(&k);
1743 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_revocation_point: PublicKey, logger: &L) where L::Target: Logger {
1744 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
1745 // so that a remote monitor doesn't learn anything unless there is a malicious close.
1746 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
1748 for &(ref htlc, _) in &htlc_outputs {
1749 self.counterparty_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
1752 log_trace!(logger, "Tracking new counterparty commitment transaction with txid {} at commitment number {} with {} HTLC outputs", txid, commitment_number, htlc_outputs.len());
1753 self.prev_counterparty_commitment_txid = self.current_counterparty_commitment_txid.take();
1754 self.current_counterparty_commitment_txid = Some(txid);
1755 self.counterparty_claimable_outpoints.insert(txid, htlc_outputs.clone());
1756 self.current_counterparty_commitment_number = commitment_number;
1757 //TODO: Merge this into the other per-counterparty-transaction output storage stuff
1758 match self.their_cur_revocation_points {
1759 Some(old_points) => {
1760 if old_points.0 == commitment_number + 1 {
1761 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(their_revocation_point)));
1762 } else if old_points.0 == commitment_number + 2 {
1763 if let Some(old_second_point) = old_points.2 {
1764 self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(their_revocation_point)));
1766 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1769 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1773 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1776 let mut htlcs = Vec::with_capacity(htlc_outputs.len());
1777 for htlc in htlc_outputs {
1778 if htlc.0.transaction_output_index.is_some() {
1784 /// Informs this monitor of the latest holder (ie broadcastable) commitment transaction. The
1785 /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
1786 /// is important that any clones of this channel monitor (including remote clones) by kept
1787 /// up-to-date as our holder commitment transaction is updated.
1788 /// Panics if set_on_holder_tx_csv has never been called.
1789 fn provide_latest_holder_commitment_tx(&mut self, holder_commitment_tx: HolderCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), MonitorUpdateError> {
1790 // block for Rust 1.34 compat
1791 let mut new_holder_commitment_tx = {
1792 let trusted_tx = holder_commitment_tx.trust();
1793 let txid = trusted_tx.txid();
1794 let tx_keys = trusted_tx.keys();
1795 self.current_holder_commitment_number = trusted_tx.commitment_number();
1798 revocation_key: tx_keys.revocation_key,
1799 a_htlc_key: tx_keys.broadcaster_htlc_key,
1800 b_htlc_key: tx_keys.countersignatory_htlc_key,
1801 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
1802 per_commitment_point: tx_keys.per_commitment_point,
1804 to_self_value_sat: holder_commitment_tx.to_broadcaster_value_sat(),
1805 feerate_per_kw: trusted_tx.feerate_per_kw(),
1808 self.onchain_tx_handler.provide_latest_holder_tx(holder_commitment_tx);
1809 mem::swap(&mut new_holder_commitment_tx, &mut self.current_holder_commitment_tx);
1810 self.prev_holder_signed_commitment_tx = Some(new_holder_commitment_tx);
1811 if self.holder_tx_signed {
1812 return Err(MonitorUpdateError("Latest holder commitment signed has already been signed, update is rejected"));
1817 /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
1818 /// commitment_tx_infos which contain the payment hash have been revoked.
1819 fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage, broadcaster: &B, fee_estimator: &F, logger: &L)
1820 where B::Target: BroadcasterInterface,
1821 F::Target: FeeEstimator,
1824 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
1826 // If the channel is force closed, try to claim the output from this preimage.
1827 // First check if a counterparty commitment transaction has been broadcasted:
1828 macro_rules! claim_htlcs {
1829 ($commitment_number: expr, $txid: expr) => {
1830 let htlc_claim_reqs = self.get_counterparty_htlc_output_claim_reqs($commitment_number, $txid, None);
1831 self.onchain_tx_handler.update_claims_view(&Vec::new(), htlc_claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
1834 if let Some(txid) = self.current_counterparty_commitment_txid {
1835 if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
1836 claim_htlcs!(*commitment_number, txid);
1840 if let Some(txid) = self.prev_counterparty_commitment_txid {
1841 if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
1842 claim_htlcs!(*commitment_number, txid);
1847 // Then if a holder commitment transaction has been seen on-chain, broadcast transactions
1848 // claiming the HTLC output from each of the holder commitment transactions.
1849 // Note that we can't just use `self.holder_tx_signed`, because that only covers the case where
1850 // *we* sign a holder commitment transaction, not when e.g. a watchtower broadcasts one of our
1851 // holder commitment transactions.
1852 if self.broadcasted_holder_revokable_script.is_some() {
1853 // Assume that the broadcasted commitment transaction confirmed in the current best
1854 // block. Even if not, its a reasonable metric for the bump criteria on the HTLC
1856 let (claim_reqs, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
1857 self.onchain_tx_handler.update_claims_view(&Vec::new(), claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
1858 if let Some(ref tx) = self.prev_holder_signed_commitment_tx {
1859 let (claim_reqs, _) = self.get_broadcasted_holder_claims(&tx, self.best_block.height());
1860 self.onchain_tx_handler.update_claims_view(&Vec::new(), claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
1865 pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
1866 where B::Target: BroadcasterInterface,
1869 for tx in self.get_latest_holder_commitment_txn(logger).iter() {
1870 log_info!(logger, "Broadcasting local {}", log_tx!(tx));
1871 broadcaster.broadcast_transaction(tx);
1873 self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
1876 pub fn update_monitor<B: Deref, F: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: &F, logger: &L) -> Result<(), MonitorUpdateError>
1877 where B::Target: BroadcasterInterface,
1878 F::Target: FeeEstimator,
1881 // ChannelMonitor updates may be applied after force close if we receive a
1882 // preimage for a broadcasted commitment transaction HTLC output that we'd
1883 // like to claim on-chain. If this is the case, we no longer have guaranteed
1884 // access to the monitor's update ID, so we use a sentinel value instead.
1885 if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
1886 match updates.updates[0] {
1887 ChannelMonitorUpdateStep::PaymentPreimage { .. } => {},
1888 _ => panic!("Attempted to apply post-force-close ChannelMonitorUpdate that wasn't providing a payment preimage"),
1890 assert_eq!(updates.updates.len(), 1);
1891 } else if self.latest_update_id + 1 != updates.update_id {
1892 panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
1894 for update in updates.updates.iter() {
1896 ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs } => {
1897 log_trace!(logger, "Updating ChannelMonitor with latest holder commitment transaction info");
1898 if self.lockdown_from_offchain { panic!(); }
1899 self.provide_latest_holder_commitment_tx(commitment_tx.clone(), htlc_outputs.clone())?
1901 ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid, htlc_outputs, commitment_number, their_revocation_point } => {
1902 log_trace!(logger, "Updating ChannelMonitor with latest counterparty commitment transaction info");
1903 self.provide_latest_counterparty_commitment_tx(*commitment_txid, htlc_outputs.clone(), *commitment_number, *their_revocation_point, logger)
1905 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } => {
1906 log_trace!(logger, "Updating ChannelMonitor with payment preimage");
1907 self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage, broadcaster, fee_estimator, logger)
1909 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } => {
1910 log_trace!(logger, "Updating ChannelMonitor with commitment secret");
1911 self.provide_secret(*idx, *secret)?
1913 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
1914 log_trace!(logger, "Updating ChannelMonitor: channel force closed, should broadcast: {}", should_broadcast);
1915 self.lockdown_from_offchain = true;
1916 if *should_broadcast {
1917 self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
1918 } else if !self.holder_tx_signed {
1919 log_error!(logger, "You have a toxic holder commitment transaction avaible in channel monitor, read comment in ChannelMonitor::get_latest_holder_commitment_txn to be informed of manual action to take");
1921 // If we generated a MonitorEvent::CommitmentTxConfirmed, the ChannelManager
1922 // will still give us a ChannelForceClosed event with !should_broadcast, but we
1923 // shouldn't print the scary warning above.
1924 log_info!(logger, "Channel off-chain state closed after we broadcasted our latest commitment transaction.");
1927 ChannelMonitorUpdateStep::ShutdownScript { scriptpubkey } => {
1928 log_trace!(logger, "Updating ChannelMonitor with shutdown script");
1929 if let Some(shutdown_script) = self.shutdown_script.replace(scriptpubkey.clone()) {
1930 panic!("Attempted to replace shutdown script {} with {}", shutdown_script, scriptpubkey);
1935 self.latest_update_id = updates.update_id;
1939 pub fn get_latest_update_id(&self) -> u64 {
1940 self.latest_update_id
1943 pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
1947 pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<(u32, Script)>> {
1948 // If we've detected a counterparty commitment tx on chain, we must include it in the set
1949 // of outputs to watch for spends of, otherwise we're likely to lose user funds. Because
1950 // its trivial to do, double-check that here.
1951 for (txid, _) in self.counterparty_commitment_txn_on_chain.iter() {
1952 self.outputs_to_watch.get(txid).expect("Counterparty commitment txn which have been broadcast should have outputs registered");
1954 &self.outputs_to_watch
1957 pub fn get_and_clear_pending_monitor_events(&mut self) -> Vec<MonitorEvent> {
1958 let mut ret = Vec::new();
1959 mem::swap(&mut ret, &mut self.pending_monitor_events);
1963 pub fn get_and_clear_pending_events(&mut self) -> Vec<Event> {
1964 let mut ret = Vec::new();
1965 mem::swap(&mut ret, &mut self.pending_events);
1969 /// Can only fail if idx is < get_min_seen_secret
1970 fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
1971 self.commitment_secrets.get_secret(idx)
1974 pub(crate) fn get_min_seen_secret(&self) -> u64 {
1975 self.commitment_secrets.get_min_seen_secret()
1978 pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1979 self.current_counterparty_commitment_number
1982 pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
1983 self.current_holder_commitment_number
1986 /// Attempts to claim a counterparty commitment transaction's outputs using the revocation key and
1987 /// data in counterparty_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
1988 /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
1989 /// HTLC-Success/HTLC-Timeout transactions.
1990 /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of
1991 /// revoked counterparty commitment tx
1992 fn check_spend_counterparty_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<PackageTemplate>, TransactionOutputs) where L::Target: Logger {
1993 // Most secp and related errors trying to create keys means we have no hope of constructing
1994 // a spend transaction...so we return no transactions to broadcast
1995 let mut claimable_outpoints = Vec::new();
1996 let mut watch_outputs = Vec::new();
1998 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1999 let per_commitment_option = self.counterparty_claimable_outpoints.get(&commitment_txid);
2001 macro_rules! ignore_error {
2002 ( $thing : expr ) => {
2005 Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs))
2010 let commitment_number = 0xffffffffffff - ((((tx.input[0].sequence as u64 & 0xffffff) << 3*8) | (tx.lock_time as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor);
2011 if commitment_number >= self.get_min_seen_secret() {
2012 let secret = self.get_secret(commitment_number).unwrap();
2013 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
2014 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
2015 let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint));
2016 let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.counterparty_commitment_params.counterparty_delayed_payment_base_key));
2018 let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.counterparty_commitment_params.on_counterparty_tx_csv, &delayed_key);
2019 let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
2021 // First, process non-htlc outputs (to_holder & to_counterparty)
2022 for (idx, outp) in tx.output.iter().enumerate() {
2023 if outp.script_pubkey == revokeable_p2wsh {
2024 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);
2025 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);
2026 claimable_outpoints.push(justice_package);
2030 // Then, try to find revoked htlc outputs
2031 if let Some(ref per_commitment_data) = per_commitment_option {
2032 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
2033 if let Some(transaction_output_index) = htlc.transaction_output_index {
2034 if transaction_output_index as usize >= tx.output.len() ||
2035 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
2036 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
2038 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());
2039 let justice_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, PackageSolvingData::RevokedHTLCOutput(revk_htlc_outp), htlc.cltv_expiry, true, height);
2040 claimable_outpoints.push(justice_package);
2045 // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
2046 if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
2047 // We're definitely a counterparty commitment transaction!
2048 log_error!(logger, "Got broadcast of revoked counterparty commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
2049 for (idx, outp) in tx.output.iter().enumerate() {
2050 watch_outputs.push((idx as u32, outp.clone()));
2052 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
2054 fail_unbroadcast_htlcs!(self, "revoked counterparty", height, [].iter().map(|a| *a), logger);
2056 } else if let Some(per_commitment_data) = per_commitment_option {
2057 // While this isn't useful yet, there is a potential race where if a counterparty
2058 // revokes a state at the same time as the commitment transaction for that state is
2059 // confirmed, and the watchtower receives the block before the user, the user could
2060 // upload a new ChannelMonitor with the revocation secret but the watchtower has
2061 // already processed the block, resulting in the counterparty_commitment_txn_on_chain entry
2062 // not being generated by the above conditional. Thus, to be safe, we go ahead and
2064 for (idx, outp) in tx.output.iter().enumerate() {
2065 watch_outputs.push((idx as u32, outp.clone()));
2067 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
2069 log_info!(logger, "Got broadcast of non-revoked counterparty commitment transaction {}", commitment_txid);
2070 fail_unbroadcast_htlcs!(self, "counterparty", height, per_commitment_data.iter().map(|(a, b)| (a, b.as_ref().map(|b| b.as_ref()))), logger);
2072 let htlc_claim_reqs = self.get_counterparty_htlc_output_claim_reqs(commitment_number, commitment_txid, Some(tx));
2073 for req in htlc_claim_reqs {
2074 claimable_outpoints.push(req);
2078 (claimable_outpoints, (commitment_txid, watch_outputs))
2081 fn get_counterparty_htlc_output_claim_reqs(&self, commitment_number: u64, commitment_txid: Txid, tx: Option<&Transaction>) -> Vec<PackageTemplate> {
2082 let mut claimable_outpoints = Vec::new();
2083 if let Some(htlc_outputs) = self.counterparty_claimable_outpoints.get(&commitment_txid) {
2084 if let Some(revocation_points) = self.their_cur_revocation_points {
2085 let revocation_point_option =
2086 // If the counterparty commitment tx is the latest valid state, use their latest
2087 // per-commitment point
2088 if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
2089 else if let Some(point) = revocation_points.2.as_ref() {
2090 // If counterparty commitment tx is the state previous to the latest valid state, use
2091 // their previous per-commitment point (non-atomicity of revocation means it's valid for
2092 // them to temporarily have two valid commitment txns from our viewpoint)
2093 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
2095 if let Some(revocation_point) = revocation_point_option {
2096 for (_, &(ref htlc, _)) in htlc_outputs.iter().enumerate() {
2097 if let Some(transaction_output_index) = htlc.transaction_output_index {
2098 if let Some(transaction) = tx {
2099 if transaction_output_index as usize >= transaction.output.len() ||
2100 transaction.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
2101 return claimable_outpoints; // Corrupted per_commitment_data, fuck this user
2104 let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
2105 if preimage.is_some() || !htlc.offered {
2106 let counterparty_htlc_outp = if htlc.offered { PackageSolvingData::CounterpartyOfferedHTLCOutput(CounterpartyOfferedHTLCOutput::build(*revocation_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key, self.counterparty_commitment_params.counterparty_htlc_base_key, preimage.unwrap(), htlc.clone())) } else { PackageSolvingData::CounterpartyReceivedHTLCOutput(CounterpartyReceivedHTLCOutput::build(*revocation_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key, self.counterparty_commitment_params.counterparty_htlc_base_key, htlc.clone())) };
2107 let aggregation = if !htlc.offered { false } else { true };
2108 let counterparty_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, counterparty_htlc_outp, htlc.cltv_expiry,aggregation, 0);
2109 claimable_outpoints.push(counterparty_package);
2119 /// Attempts to claim a counterparty HTLC-Success/HTLC-Timeout's outputs using the revocation key
2120 fn check_spend_counterparty_htlc<L: Deref>(&mut self, tx: &Transaction, commitment_number: u64, height: u32, logger: &L) -> (Vec<PackageTemplate>, Option<TransactionOutputs>) where L::Target: Logger {
2121 let htlc_txid = tx.txid();
2122 if tx.input.len() != 1 || tx.output.len() != 1 || tx.input[0].witness.len() != 5 {
2123 return (Vec::new(), None)
2126 macro_rules! ignore_error {
2127 ( $thing : expr ) => {
2130 Err(_) => return (Vec::new(), None)
2135 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
2136 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
2137 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
2139 log_error!(logger, "Got broadcast of revoked counterparty HTLC transaction, spending {}:{}", htlc_txid, 0);
2140 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, tx.output[0].value, self.counterparty_commitment_params.on_counterparty_tx_csv);
2141 let justice_package = PackageTemplate::build_package(htlc_txid, 0, PackageSolvingData::RevokedOutput(revk_outp), height + self.counterparty_commitment_params.on_counterparty_tx_csv as u32, true, height);
2142 let claimable_outpoints = vec!(justice_package);
2143 let outputs = vec![(0, tx.output[0].clone())];
2144 (claimable_outpoints, Some((htlc_txid, outputs)))
2147 // Returns (1) `PackageTemplate`s that can be given to the OnChainTxHandler, so that the handler can
2148 // broadcast transactions claiming holder HTLC commitment outputs and (2) a holder revokable
2149 // script so we can detect whether a holder transaction has been seen on-chain.
2150 fn get_broadcasted_holder_claims(&self, holder_tx: &HolderSignedTx, conf_height: u32) -> (Vec<PackageTemplate>, Option<(Script, PublicKey, PublicKey)>) {
2151 let mut claim_requests = Vec::with_capacity(holder_tx.htlc_outputs.len());
2153 let redeemscript = chan_utils::get_revokeable_redeemscript(&holder_tx.revocation_key, self.on_holder_tx_csv, &holder_tx.delayed_payment_key);
2154 let broadcasted_holder_revokable_script = Some((redeemscript.to_v0_p2wsh(), holder_tx.per_commitment_point.clone(), holder_tx.revocation_key.clone()));
2156 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
2157 if let Some(transaction_output_index) = htlc.transaction_output_index {
2158 let htlc_output = if htlc.offered {
2159 HolderHTLCOutput::build_offered(htlc.amount_msat, htlc.cltv_expiry)
2161 let payment_preimage = if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
2164 // We can't build an HTLC-Success transaction without the preimage
2167 HolderHTLCOutput::build_accepted(payment_preimage, htlc.amount_msat)
2169 let htlc_package = PackageTemplate::build_package(holder_tx.txid, transaction_output_index, PackageSolvingData::HolderHTLCOutput(htlc_output), htlc.cltv_expiry, false, conf_height);
2170 claim_requests.push(htlc_package);
2174 (claim_requests, broadcasted_holder_revokable_script)
2177 // Returns holder HTLC outputs to watch and react to in case of spending.
2178 fn get_broadcasted_holder_watch_outputs(&self, holder_tx: &HolderSignedTx, commitment_tx: &Transaction) -> Vec<(u32, TxOut)> {
2179 let mut watch_outputs = Vec::with_capacity(holder_tx.htlc_outputs.len());
2180 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
2181 if let Some(transaction_output_index) = htlc.transaction_output_index {
2182 watch_outputs.push((transaction_output_index, commitment_tx.output[transaction_output_index as usize].clone()));
2188 /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
2189 /// revoked using data in holder_claimable_outpoints.
2190 /// Should not be used if check_spend_revoked_transaction succeeds.
2191 /// Returns None unless the transaction is definitely one of our commitment transactions.
2192 fn check_spend_holder_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> Option<(Vec<PackageTemplate>, TransactionOutputs)> where L::Target: Logger {
2193 let commitment_txid = tx.txid();
2194 let mut claim_requests = Vec::new();
2195 let mut watch_outputs = Vec::new();
2197 macro_rules! append_onchain_update {
2198 ($updates: expr, $to_watch: expr) => {
2199 claim_requests = $updates.0;
2200 self.broadcasted_holder_revokable_script = $updates.1;
2201 watch_outputs.append(&mut $to_watch);
2205 // HTLCs set may differ between last and previous holder commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
2206 let mut is_holder_tx = false;
2208 if self.current_holder_commitment_tx.txid == commitment_txid {
2209 is_holder_tx = true;
2210 log_info!(logger, "Got broadcast of latest holder commitment tx {}, searching for available HTLCs to claim", commitment_txid);
2211 let res = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, height);
2212 let mut to_watch = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, tx);
2213 append_onchain_update!(res, to_watch);
2214 fail_unbroadcast_htlcs!(self, "latest holder", height, self.current_holder_commitment_tx.htlc_outputs.iter().map(|(a, _, c)| (a, c.as_ref())), logger);
2215 } else if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
2216 if holder_tx.txid == commitment_txid {
2217 is_holder_tx = true;
2218 log_info!(logger, "Got broadcast of previous holder commitment tx {}, searching for available HTLCs to claim", commitment_txid);
2219 let res = self.get_broadcasted_holder_claims(holder_tx, height);
2220 let mut to_watch = self.get_broadcasted_holder_watch_outputs(holder_tx, tx);
2221 append_onchain_update!(res, to_watch);
2222 fail_unbroadcast_htlcs!(self, "previous holder", height, holder_tx.htlc_outputs.iter().map(|(a, _, c)| (a, c.as_ref())), logger);
2227 Some((claim_requests, (commitment_txid, watch_outputs)))
2233 pub fn get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
2234 log_debug!(logger, "Getting signed latest holder commitment transaction!");
2235 self.holder_tx_signed = true;
2236 let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
2237 let txid = commitment_tx.txid();
2238 let mut holder_transactions = vec![commitment_tx];
2239 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
2240 if let Some(vout) = htlc.0.transaction_output_index {
2241 let preimage = if !htlc.0.offered {
2242 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
2243 // We can't build an HTLC-Success transaction without the preimage
2246 } else if htlc.0.cltv_expiry > self.best_block.height() + 1 {
2247 // Don't broadcast HTLC-Timeout transactions immediately as they don't meet the
2248 // current locktime requirements on-chain. We will broadcast them in
2249 // `block_confirmed` when `should_broadcast_holder_commitment_txn` returns true.
2250 // Note that we add + 1 as transactions are broadcastable when they can be
2251 // confirmed in the next block.
2254 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
2255 &::bitcoin::OutPoint { txid, vout }, &preimage) {
2256 holder_transactions.push(htlc_tx);
2260 // 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.
2261 // The data will be re-generated and tracked in check_spend_holder_transaction if we get a confirmation.
2265 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
2266 /// Note that this includes possibly-locktimed-in-the-future transactions!
2267 fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
2268 log_debug!(logger, "Getting signed copy of latest holder commitment transaction!");
2269 let commitment_tx = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript);
2270 let txid = commitment_tx.txid();
2271 let mut holder_transactions = vec![commitment_tx];
2272 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
2273 if let Some(vout) = htlc.0.transaction_output_index {
2274 let preimage = if !htlc.0.offered {
2275 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
2276 // We can't build an HTLC-Success transaction without the preimage
2280 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
2281 &::bitcoin::OutPoint { txid, vout }, &preimage) {
2282 holder_transactions.push(htlc_tx);
2289 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>
2290 where B::Target: BroadcasterInterface,
2291 F::Target: FeeEstimator,
2294 let block_hash = header.block_hash();
2295 self.best_block = BestBlock::new(block_hash, height);
2297 self.transactions_confirmed(header, txdata, height, broadcaster, fee_estimator, logger)
2300 fn best_block_updated<B: Deref, F: Deref, L: Deref>(
2302 header: &BlockHeader,
2307 ) -> Vec<TransactionOutputs>
2309 B::Target: BroadcasterInterface,
2310 F::Target: FeeEstimator,
2313 let block_hash = header.block_hash();
2315 if height > self.best_block.height() {
2316 self.best_block = BestBlock::new(block_hash, height);
2317 self.block_confirmed(height, vec![], vec![], vec![], &broadcaster, &fee_estimator, &logger)
2318 } else if block_hash != self.best_block.block_hash() {
2319 self.best_block = BestBlock::new(block_hash, height);
2320 self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height <= height);
2321 self.onchain_tx_handler.block_disconnected(height + 1, broadcaster, fee_estimator, logger);
2323 } else { Vec::new() }
2326 fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
2328 header: &BlockHeader,
2329 txdata: &TransactionData,
2334 ) -> Vec<TransactionOutputs>
2336 B::Target: BroadcasterInterface,
2337 F::Target: FeeEstimator,
2340 let txn_matched = self.filter_block(txdata);
2341 for tx in &txn_matched {
2342 let mut output_val = 0;
2343 for out in tx.output.iter() {
2344 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
2345 output_val += out.value;
2346 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
2350 let block_hash = header.block_hash();
2352 let mut watch_outputs = Vec::new();
2353 let mut claimable_outpoints = Vec::new();
2354 for tx in &txn_matched {
2355 if tx.input.len() == 1 {
2356 // Assuming our keys were not leaked (in which case we're screwed no matter what),
2357 // commitment transactions and HTLC transactions will all only ever have one input,
2358 // which is an easy way to filter out any potential non-matching txn for lazy
2360 let prevout = &tx.input[0].previous_output;
2361 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
2362 let mut balance_spendable_csv = None;
2363 log_info!(logger, "Channel closed by funding output spend in txid {}.", log_bytes!(tx.txid()));
2364 if (tx.input[0].sequence >> 8*3) as u8 == 0x80 && (tx.lock_time >> 8*3) as u8 == 0x20 {
2365 let (mut new_outpoints, new_outputs) = self.check_spend_counterparty_transaction(&tx, height, &logger);
2366 if !new_outputs.1.is_empty() {
2367 watch_outputs.push(new_outputs);
2369 claimable_outpoints.append(&mut new_outpoints);
2370 if new_outpoints.is_empty() {
2371 if let Some((mut new_outpoints, new_outputs)) = self.check_spend_holder_transaction(&tx, height, &logger) {
2372 if !new_outputs.1.is_empty() {
2373 watch_outputs.push(new_outputs);
2375 claimable_outpoints.append(&mut new_outpoints);
2376 balance_spendable_csv = Some(self.on_holder_tx_csv);
2380 let txid = tx.txid();
2381 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
2384 event: OnchainEvent::FundingSpendConfirmation {
2385 on_local_output_csv: balance_spendable_csv,
2389 if let Some(&commitment_number) = self.counterparty_commitment_txn_on_chain.get(&prevout.txid) {
2390 let (mut new_outpoints, new_outputs_option) = self.check_spend_counterparty_htlc(&tx, commitment_number, height, &logger);
2391 claimable_outpoints.append(&mut new_outpoints);
2392 if let Some(new_outputs) = new_outputs_option {
2393 watch_outputs.push(new_outputs);
2398 // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
2399 // can also be resolved in a few other ways which can have more than one output. Thus,
2400 // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
2401 self.is_resolving_htlc_output(&tx, height, &logger);
2403 self.is_paying_spendable_output(&tx, height, &logger);
2406 if height > self.best_block.height() {
2407 self.best_block = BestBlock::new(block_hash, height);
2410 self.block_confirmed(height, txn_matched, watch_outputs, claimable_outpoints, &broadcaster, &fee_estimator, &logger)
2413 /// Update state for new block(s)/transaction(s) confirmed. Note that the caller must update
2414 /// `self.best_block` before calling if a new best blockchain tip is available. More
2415 /// concretely, `self.best_block` must never be at a lower height than `conf_height`, avoiding
2416 /// complexity especially in `OnchainTx::update_claims_view`.
2418 /// `conf_height` should be set to the height at which any new transaction(s)/block(s) were
2419 /// confirmed at, even if it is not the current best height.
2420 fn block_confirmed<B: Deref, F: Deref, L: Deref>(
2423 txn_matched: Vec<&Transaction>,
2424 mut watch_outputs: Vec<TransactionOutputs>,
2425 mut claimable_outpoints: Vec<PackageTemplate>,
2429 ) -> Vec<TransactionOutputs>
2431 B::Target: BroadcasterInterface,
2432 F::Target: FeeEstimator,
2435 log_trace!(logger, "Processing {} matched transactions for block at height {}.", txn_matched.len(), conf_height);
2436 debug_assert!(self.best_block.height() >= conf_height);
2438 let should_broadcast = self.should_broadcast_holder_commitment_txn(logger);
2439 if should_broadcast {
2440 let funding_outp = HolderFundingOutput::build(self.funding_redeemscript.clone());
2441 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());
2442 claimable_outpoints.push(commitment_package);
2443 self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
2444 let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
2445 self.holder_tx_signed = true;
2446 // Because we're broadcasting a commitment transaction, we should construct the package
2447 // assuming it gets confirmed in the next block. Sadly, we have code which considers
2448 // "not yet confirmed" things as discardable, so we cannot do that here.
2449 let (mut new_outpoints, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
2450 let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &commitment_tx);
2451 if !new_outputs.is_empty() {
2452 watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
2454 claimable_outpoints.append(&mut new_outpoints);
2457 // Find which on-chain events have reached their confirmation threshold.
2458 let onchain_events_awaiting_threshold_conf =
2459 self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
2460 let mut onchain_events_reaching_threshold_conf = Vec::new();
2461 for entry in onchain_events_awaiting_threshold_conf {
2462 if entry.has_reached_confirmation_threshold(&self.best_block) {
2463 onchain_events_reaching_threshold_conf.push(entry);
2465 self.onchain_events_awaiting_threshold_conf.push(entry);
2469 // Used to check for duplicate HTLC resolutions.
2470 #[cfg(debug_assertions)]
2471 let unmatured_htlcs: Vec<_> = self.onchain_events_awaiting_threshold_conf
2473 .filter_map(|entry| match &entry.event {
2474 OnchainEvent::HTLCUpdate { source, .. } => Some(source),
2478 #[cfg(debug_assertions)]
2479 let mut matured_htlcs = Vec::new();
2481 // Produce actionable events from on-chain events having reached their threshold.
2482 for entry in onchain_events_reaching_threshold_conf.drain(..) {
2484 OnchainEvent::HTLCUpdate { ref source, payment_hash, onchain_value_satoshis, input_idx } => {
2485 // Check for duplicate HTLC resolutions.
2486 #[cfg(debug_assertions)]
2489 unmatured_htlcs.iter().find(|&htlc| htlc == &source).is_none(),
2490 "An unmature HTLC transaction conflicts with a maturing one; failed to \
2491 call either transaction_unconfirmed for the conflicting transaction \
2492 or block_disconnected for a block containing it.");
2494 matured_htlcs.iter().find(|&htlc| htlc == source).is_none(),
2495 "A matured HTLC transaction conflicts with a maturing one; failed to \
2496 call either transaction_unconfirmed for the conflicting transaction \
2497 or block_disconnected for a block containing it.");
2498 matured_htlcs.push(source.clone());
2501 log_debug!(logger, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!(payment_hash.0));
2502 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2504 payment_preimage: None,
2505 source: source.clone(),
2506 onchain_value_satoshis,
2508 if let Some(idx) = input_idx {
2509 self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC { input_idx: idx, payment_preimage: None });
2512 OnchainEvent::MaturingOutput { descriptor } => {
2513 log_debug!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
2514 self.pending_events.push(Event::SpendableOutputs {
2515 outputs: vec![descriptor]
2518 OnchainEvent::HTLCSpendConfirmation { input_idx, preimage, .. } => {
2519 self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC { input_idx, payment_preimage: preimage });
2521 OnchainEvent::FundingSpendConfirmation { .. } => {
2522 self.funding_spend_confirmed = Some(entry.txid);
2527 self.onchain_tx_handler.update_claims_view(&txn_matched, claimable_outpoints, conf_height, self.best_block.height(), broadcaster, fee_estimator, logger);
2529 // Determine new outputs to watch by comparing against previously known outputs to watch,
2530 // updating the latter in the process.
2531 watch_outputs.retain(|&(ref txid, ref txouts)| {
2532 let idx_and_scripts = txouts.iter().map(|o| (o.0, o.1.script_pubkey.clone())).collect();
2533 self.outputs_to_watch.insert(txid.clone(), idx_and_scripts).is_none()
2537 // If we see a transaction for which we registered outputs previously,
2538 // make sure the registered scriptpubkey at the expected index match
2539 // the actual transaction output one. We failed this case before #653.
2540 for tx in &txn_matched {
2541 if let Some(outputs) = self.get_outputs_to_watch().get(&tx.txid()) {
2542 for idx_and_script in outputs.iter() {
2543 assert!((idx_and_script.0 as usize) < tx.output.len());
2544 assert_eq!(tx.output[idx_and_script.0 as usize].script_pubkey, idx_and_script.1);
2552 pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, height: u32, broadcaster: B, fee_estimator: F, logger: L)
2553 where B::Target: BroadcasterInterface,
2554 F::Target: FeeEstimator,
2557 log_trace!(logger, "Block {} at height {} disconnected", header.block_hash(), height);
2560 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
2561 //- maturing spendable output has transaction paying us has been disconnected
2562 self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height < height);
2564 self.onchain_tx_handler.block_disconnected(height, broadcaster, fee_estimator, logger);
2566 self.best_block = BestBlock::new(header.prev_blockhash, height - 1);
2569 fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
2576 B::Target: BroadcasterInterface,
2577 F::Target: FeeEstimator,
2580 self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.txid != *txid);
2581 self.onchain_tx_handler.transaction_unconfirmed(txid, broadcaster, fee_estimator, logger);
2584 /// Filters a block's `txdata` for transactions spending watched outputs or for any child
2585 /// transactions thereof.
2586 fn filter_block<'a>(&self, txdata: &TransactionData<'a>) -> Vec<&'a Transaction> {
2587 let mut matched_txn = HashSet::new();
2588 txdata.iter().filter(|&&(_, tx)| {
2589 let mut matches = self.spends_watched_output(tx);
2590 for input in tx.input.iter() {
2591 if matches { break; }
2592 if matched_txn.contains(&input.previous_output.txid) {
2597 matched_txn.insert(tx.txid());
2600 }).map(|(_, tx)| *tx).collect()
2603 /// Checks if a given transaction spends any watched outputs.
2604 fn spends_watched_output(&self, tx: &Transaction) -> bool {
2605 for input in tx.input.iter() {
2606 if let Some(outputs) = self.get_outputs_to_watch().get(&input.previous_output.txid) {
2607 for (idx, _script_pubkey) in outputs.iter() {
2608 if *idx == input.previous_output.vout {
2611 // If the expected script is a known type, check that the witness
2612 // appears to be spending the correct type (ie that the match would
2613 // actually succeed in BIP 158/159-style filters).
2614 if _script_pubkey.is_v0_p2wsh() {
2615 assert_eq!(&bitcoin::Address::p2wsh(&Script::from(input.witness.last().unwrap().clone()), bitcoin::Network::Bitcoin).script_pubkey(), _script_pubkey);
2616 } else if _script_pubkey.is_v0_p2wpkh() {
2617 assert_eq!(&bitcoin::Address::p2wpkh(&bitcoin::PublicKey::from_slice(&input.witness.last().unwrap()).unwrap(), bitcoin::Network::Bitcoin).unwrap().script_pubkey(), _script_pubkey);
2618 } else { panic!(); }
2629 fn should_broadcast_holder_commitment_txn<L: Deref>(&self, logger: &L) -> bool where L::Target: Logger {
2630 // We need to consider all HTLCs which are:
2631 // * in any unrevoked counterparty commitment transaction, as they could broadcast said
2632 // transactions and we'd end up in a race, or
2633 // * are in our latest holder commitment transaction, as this is the thing we will
2634 // broadcast if we go on-chain.
2635 // Note that we consider HTLCs which were below dust threshold here - while they don't
2636 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
2637 // to the source, and if we don't fail the channel we will have to ensure that the next
2638 // updates that peer sends us are update_fails, failing the channel if not. It's probably
2639 // easier to just fail the channel as this case should be rare enough anyway.
2640 let height = self.best_block.height();
2641 macro_rules! scan_commitment {
2642 ($htlcs: expr, $holder_tx: expr) => {
2643 for ref htlc in $htlcs {
2644 // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
2645 // chain with enough room to claim the HTLC without our counterparty being able to
2646 // time out the HTLC first.
2647 // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
2648 // concern is being able to claim the corresponding inbound HTLC (on another
2649 // channel) before it expires. In fact, we don't even really care if our
2650 // counterparty here claims such an outbound HTLC after it expired as long as we
2651 // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
2652 // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
2653 // we give ourselves a few blocks of headroom after expiration before going
2654 // on-chain for an expired HTLC.
2655 // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
2656 // from us until we've reached the point where we go on-chain with the
2657 // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
2658 // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
2659 // aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
2660 // inbound_cltv == height + CLTV_CLAIM_BUFFER
2661 // outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
2662 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
2663 // CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
2664 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
2665 // The final, above, condition is checked for statically in channelmanager
2666 // with CHECK_CLTV_EXPIRY_SANITY_2.
2667 let htlc_outbound = $holder_tx == htlc.offered;
2668 if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
2669 (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
2670 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
2677 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
2679 if let Some(ref txid) = self.current_counterparty_commitment_txid {
2680 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2681 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2684 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
2685 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2686 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2693 /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a holder
2694 /// or counterparty commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
2695 fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2696 'outer_loop: for input in &tx.input {
2697 let mut payment_data = None;
2698 let revocation_sig_claim = (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC) && input.witness[1].len() == 33)
2699 || (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::AcceptedHTLC) && input.witness[1].len() == 33);
2700 let accepted_preimage_claim = input.witness.len() == 5 && HTLCType::scriptlen_to_htlctype(input.witness[4].len()) == Some(HTLCType::AcceptedHTLC);
2701 #[cfg(not(fuzzing))]
2702 let accepted_timeout_claim = input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::AcceptedHTLC) && !revocation_sig_claim;
2703 let offered_preimage_claim = input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC) && !revocation_sig_claim;
2704 #[cfg(not(fuzzing))]
2705 let offered_timeout_claim = input.witness.len() == 5 && HTLCType::scriptlen_to_htlctype(input.witness[4].len()) == Some(HTLCType::OfferedHTLC);
2707 let mut payment_preimage = PaymentPreimage([0; 32]);
2708 if accepted_preimage_claim {
2709 payment_preimage.0.copy_from_slice(&input.witness[3]);
2710 } else if offered_preimage_claim {
2711 payment_preimage.0.copy_from_slice(&input.witness[1]);
2714 macro_rules! log_claim {
2715 ($tx_info: expr, $holder_tx: expr, $htlc: expr, $source_avail: expr) => {
2716 let outbound_htlc = $holder_tx == $htlc.offered;
2717 // HTLCs must either be claimed by a matching script type or through the
2719 #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
2720 debug_assert!(!$htlc.offered || offered_preimage_claim || offered_timeout_claim || revocation_sig_claim);
2721 #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
2722 debug_assert!($htlc.offered || accepted_preimage_claim || accepted_timeout_claim || revocation_sig_claim);
2723 // Further, only exactly one of the possible spend paths should have been
2724 // matched by any HTLC spend:
2725 #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
2726 debug_assert_eq!(accepted_preimage_claim as u8 + accepted_timeout_claim as u8 +
2727 offered_preimage_claim as u8 + offered_timeout_claim as u8 +
2728 revocation_sig_claim as u8, 1);
2729 if ($holder_tx && revocation_sig_claim) ||
2730 (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
2731 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
2732 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2733 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2734 if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back" });
2736 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
2737 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2738 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2739 if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
2744 macro_rules! check_htlc_valid_counterparty {
2745 ($counterparty_txid: expr, $htlc_output: expr) => {
2746 if let Some(txid) = $counterparty_txid {
2747 for &(ref pending_htlc, ref pending_source) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
2748 if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
2749 if let &Some(ref source) = pending_source {
2750 log_claim!("revoked counterparty commitment tx", false, pending_htlc, true);
2751 payment_data = Some(((**source).clone(), $htlc_output.payment_hash, $htlc_output.amount_msat));
2760 macro_rules! scan_commitment {
2761 ($htlcs: expr, $tx_info: expr, $holder_tx: expr) => {
2762 for (ref htlc_output, source_option) in $htlcs {
2763 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
2764 if let Some(ref source) = source_option {
2765 log_claim!($tx_info, $holder_tx, htlc_output, true);
2766 // We have a resolution of an HTLC either from one of our latest
2767 // holder commitment transactions or an unrevoked counterparty commitment
2768 // transaction. This implies we either learned a preimage, the HTLC
2769 // has timed out, or we screwed up. In any case, we should now
2770 // resolve the source HTLC with the original sender.
2771 payment_data = Some(((*source).clone(), htlc_output.payment_hash, htlc_output.amount_msat));
2772 } else if !$holder_tx {
2773 check_htlc_valid_counterparty!(self.current_counterparty_commitment_txid, htlc_output);
2774 if payment_data.is_none() {
2775 check_htlc_valid_counterparty!(self.prev_counterparty_commitment_txid, htlc_output);
2778 if payment_data.is_none() {
2779 log_claim!($tx_info, $holder_tx, htlc_output, false);
2780 let outbound_htlc = $holder_tx == htlc_output.offered;
2781 if !outbound_htlc || revocation_sig_claim {
2782 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
2783 txid: tx.txid(), height,
2784 event: OnchainEvent::HTLCSpendConfirmation {
2785 input_idx: input.previous_output.vout,
2786 preimage: if accepted_preimage_claim || offered_preimage_claim {
2787 Some(payment_preimage) } else { None },
2788 // If this is a payment to us (!outbound_htlc, above),
2789 // wait for the CSV delay before dropping the HTLC from
2790 // claimable balance if the claim was an HTLC-Success
2792 on_to_local_output_csv: if accepted_preimage_claim {
2793 Some(self.on_holder_tx_csv) } else { None },
2797 // Outbound claims should always have payment_data, unless
2798 // we've already failed the HTLC as the commitment transaction
2799 // which was broadcasted was revoked. In that case, we should
2800 // spend the HTLC output here immediately, and expose that fact
2801 // as a Balance, something which we do not yet do.
2802 // TODO: Track the above as claimable!
2804 continue 'outer_loop;
2811 if input.previous_output.txid == self.current_holder_commitment_tx.txid {
2812 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2813 "our latest holder commitment tx", true);
2815 if let Some(ref prev_holder_signed_commitment_tx) = self.prev_holder_signed_commitment_tx {
2816 if input.previous_output.txid == prev_holder_signed_commitment_tx.txid {
2817 scan_commitment!(prev_holder_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2818 "our previous holder commitment tx", true);
2821 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(&input.previous_output.txid) {
2822 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
2823 "counterparty commitment tx", false);
2826 // Check that scan_commitment, above, decided there is some source worth relaying an
2827 // HTLC resolution backwards to and figure out whether we learned a preimage from it.
2828 if let Some((source, payment_hash, amount_msat)) = payment_data {
2829 if accepted_preimage_claim {
2830 if !self.pending_monitor_events.iter().any(
2831 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update { upd.source == source } else { false }) {
2832 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
2835 event: OnchainEvent::HTLCSpendConfirmation {
2836 input_idx: input.previous_output.vout,
2837 preimage: Some(payment_preimage),
2838 on_to_local_output_csv: None,
2841 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2843 payment_preimage: Some(payment_preimage),
2845 onchain_value_satoshis: Some(amount_msat / 1000),
2848 } else if offered_preimage_claim {
2849 if !self.pending_monitor_events.iter().any(
2850 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update {
2851 upd.source == source
2853 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
2856 event: OnchainEvent::HTLCSpendConfirmation {
2857 input_idx: input.previous_output.vout,
2858 preimage: Some(payment_preimage),
2859 on_to_local_output_csv: None,
2862 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2864 payment_preimage: Some(payment_preimage),
2866 onchain_value_satoshis: Some(amount_msat / 1000),
2870 self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
2871 if entry.height != height { return true; }
2873 OnchainEvent::HTLCUpdate { source: ref htlc_source, .. } => {
2874 *htlc_source != source
2879 let entry = OnchainEventEntry {
2882 event: OnchainEvent::HTLCUpdate {
2883 source, payment_hash,
2884 onchain_value_satoshis: Some(amount_msat / 1000),
2885 input_idx: Some(input.previous_output.vout),
2888 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());
2889 self.onchain_events_awaiting_threshold_conf.push(entry);
2895 /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
2896 fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2897 let mut spendable_output = None;
2898 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
2899 if i > ::core::u16::MAX as usize {
2900 // While it is possible that an output exists on chain which is greater than the
2901 // 2^16th output in a given transaction, this is only possible if the output is not
2902 // in a lightning transaction and was instead placed there by some third party who
2903 // wishes to give us money for no reason.
2904 // Namely, any lightning transactions which we pre-sign will never have anywhere
2905 // near 2^16 outputs both because such transactions must have ~2^16 outputs who's
2906 // scripts are not longer than one byte in length and because they are inherently
2907 // non-standard due to their size.
2908 // Thus, it is completely safe to ignore such outputs, and while it may result in
2909 // us ignoring non-lightning fund to us, that is only possible if someone fills
2910 // nearly a full block with garbage just to hit this case.
2913 if outp.script_pubkey == self.destination_script {
2914 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2915 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2916 output: outp.clone(),
2920 if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
2921 if broadcasted_holder_revokable_script.0 == outp.script_pubkey {
2922 spendable_output = Some(SpendableOutputDescriptor::DelayedPaymentOutput(DelayedPaymentOutputDescriptor {
2923 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2924 per_commitment_point: broadcasted_holder_revokable_script.1,
2925 to_self_delay: self.on_holder_tx_csv,
2926 output: outp.clone(),
2927 revocation_pubkey: broadcasted_holder_revokable_script.2.clone(),
2928 channel_keys_id: self.channel_keys_id,
2929 channel_value_satoshis: self.channel_value_satoshis,
2934 if self.counterparty_payment_script == outp.script_pubkey {
2935 spendable_output = Some(SpendableOutputDescriptor::StaticPaymentOutput(StaticPaymentOutputDescriptor {
2936 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2937 output: outp.clone(),
2938 channel_keys_id: self.channel_keys_id,
2939 channel_value_satoshis: self.channel_value_satoshis,
2943 if self.shutdown_script.as_ref() == Some(&outp.script_pubkey) {
2944 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2945 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2946 output: outp.clone(),
2951 if let Some(spendable_output) = spendable_output {
2952 let entry = OnchainEventEntry {
2955 event: OnchainEvent::MaturingOutput { descriptor: spendable_output.clone() },
2957 log_info!(logger, "Received spendable output {}, spendable at height {}", log_spendable!(spendable_output), entry.confirmation_threshold());
2958 self.onchain_events_awaiting_threshold_conf.push(entry);
2963 impl<Signer: Sign, T: Deref, F: Deref, L: Deref> chain::Listen for (ChannelMonitor<Signer>, T, F, L)
2965 T::Target: BroadcasterInterface,
2966 F::Target: FeeEstimator,
2969 fn block_connected(&self, block: &Block, height: u32) {
2970 let txdata: Vec<_> = block.txdata.iter().enumerate().collect();
2971 self.0.block_connected(&block.header, &txdata, height, &*self.1, &*self.2, &*self.3);
2974 fn block_disconnected(&self, header: &BlockHeader, height: u32) {
2975 self.0.block_disconnected(header, height, &*self.1, &*self.2, &*self.3);
2979 impl<Signer: Sign, T: Deref, F: Deref, L: Deref> chain::Confirm for (ChannelMonitor<Signer>, T, F, L)
2981 T::Target: BroadcasterInterface,
2982 F::Target: FeeEstimator,
2985 fn transactions_confirmed(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
2986 self.0.transactions_confirmed(header, txdata, height, &*self.1, &*self.2, &*self.3);
2989 fn transaction_unconfirmed(&self, txid: &Txid) {
2990 self.0.transaction_unconfirmed(txid, &*self.1, &*self.2, &*self.3);
2993 fn best_block_updated(&self, header: &BlockHeader, height: u32) {
2994 self.0.best_block_updated(header, height, &*self.1, &*self.2, &*self.3);
2997 fn get_relevant_txids(&self) -> Vec<Txid> {
2998 self.0.get_relevant_txids()
3002 const MAX_ALLOC_SIZE: usize = 64*1024;
3004 impl<'a, Signer: Sign, K: KeysInterface<Signer = Signer>> ReadableArgs<&'a K>
3005 for (BlockHash, ChannelMonitor<Signer>) {
3006 fn read<R: io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
3007 macro_rules! unwrap_obj {
3011 Err(_) => return Err(DecodeError::InvalidValue),
3016 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
3018 let latest_update_id: u64 = Readable::read(reader)?;
3019 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
3021 let destination_script = Readable::read(reader)?;
3022 let broadcasted_holder_revokable_script = match <u8 as Readable>::read(reader)? {
3024 let revokable_address = Readable::read(reader)?;
3025 let per_commitment_point = Readable::read(reader)?;
3026 let revokable_script = Readable::read(reader)?;
3027 Some((revokable_address, per_commitment_point, revokable_script))
3030 _ => return Err(DecodeError::InvalidValue),
3032 let counterparty_payment_script = Readable::read(reader)?;
3033 let shutdown_script = {
3034 let script = <Script as Readable>::read(reader)?;
3035 if script.is_empty() { None } else { Some(script) }
3038 let channel_keys_id = Readable::read(reader)?;
3039 let holder_revocation_basepoint = Readable::read(reader)?;
3040 // Technically this can fail and serialize fail a round-trip, but only for serialization of
3041 // barely-init'd ChannelMonitors that we can't do anything with.
3042 let outpoint = OutPoint {
3043 txid: Readable::read(reader)?,
3044 index: Readable::read(reader)?,
3046 let funding_info = (outpoint, Readable::read(reader)?);
3047 let current_counterparty_commitment_txid = Readable::read(reader)?;
3048 let prev_counterparty_commitment_txid = Readable::read(reader)?;
3050 let counterparty_commitment_params = Readable::read(reader)?;
3051 let funding_redeemscript = Readable::read(reader)?;
3052 let channel_value_satoshis = Readable::read(reader)?;
3054 let their_cur_revocation_points = {
3055 let first_idx = <U48 as Readable>::read(reader)?.0;
3059 let first_point = Readable::read(reader)?;
3060 let second_point_slice: [u8; 33] = Readable::read(reader)?;
3061 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
3062 Some((first_idx, first_point, None))
3064 Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
3069 let on_holder_tx_csv: u16 = Readable::read(reader)?;
3071 let commitment_secrets = Readable::read(reader)?;
3073 macro_rules! read_htlc_in_commitment {
3076 let offered: bool = Readable::read(reader)?;
3077 let amount_msat: u64 = Readable::read(reader)?;
3078 let cltv_expiry: u32 = Readable::read(reader)?;
3079 let payment_hash: PaymentHash = Readable::read(reader)?;
3080 let transaction_output_index: Option<u32> = Readable::read(reader)?;
3082 HTLCOutputInCommitment {
3083 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
3089 let counterparty_claimable_outpoints_len: u64 = Readable::read(reader)?;
3090 let mut counterparty_claimable_outpoints = HashMap::with_capacity(cmp::min(counterparty_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
3091 for _ in 0..counterparty_claimable_outpoints_len {
3092 let txid: Txid = Readable::read(reader)?;
3093 let htlcs_count: u64 = Readable::read(reader)?;
3094 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
3095 for _ in 0..htlcs_count {
3096 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
3098 if let Some(_) = counterparty_claimable_outpoints.insert(txid, htlcs) {
3099 return Err(DecodeError::InvalidValue);
3103 let counterparty_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
3104 let mut counterparty_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(counterparty_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
3105 for _ in 0..counterparty_commitment_txn_on_chain_len {
3106 let txid: Txid = Readable::read(reader)?;
3107 let commitment_number = <U48 as Readable>::read(reader)?.0;
3108 if let Some(_) = counterparty_commitment_txn_on_chain.insert(txid, commitment_number) {
3109 return Err(DecodeError::InvalidValue);
3113 let counterparty_hash_commitment_number_len: u64 = Readable::read(reader)?;
3114 let mut counterparty_hash_commitment_number = HashMap::with_capacity(cmp::min(counterparty_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
3115 for _ in 0..counterparty_hash_commitment_number_len {
3116 let payment_hash: PaymentHash = Readable::read(reader)?;
3117 let commitment_number = <U48 as Readable>::read(reader)?.0;
3118 if let Some(_) = counterparty_hash_commitment_number.insert(payment_hash, commitment_number) {
3119 return Err(DecodeError::InvalidValue);
3123 let mut prev_holder_signed_commitment_tx: Option<HolderSignedTx> =
3124 match <u8 as Readable>::read(reader)? {
3127 Some(Readable::read(reader)?)
3129 _ => return Err(DecodeError::InvalidValue),
3131 let mut current_holder_commitment_tx: HolderSignedTx = Readable::read(reader)?;
3133 let current_counterparty_commitment_number = <U48 as Readable>::read(reader)?.0;
3134 let current_holder_commitment_number = <U48 as Readable>::read(reader)?.0;
3136 let payment_preimages_len: u64 = Readable::read(reader)?;
3137 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
3138 for _ in 0..payment_preimages_len {
3139 let preimage: PaymentPreimage = Readable::read(reader)?;
3140 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
3141 if let Some(_) = payment_preimages.insert(hash, preimage) {
3142 return Err(DecodeError::InvalidValue);
3146 let pending_monitor_events_len: u64 = Readable::read(reader)?;
3147 let mut pending_monitor_events = Some(
3148 Vec::with_capacity(cmp::min(pending_monitor_events_len as usize, MAX_ALLOC_SIZE / (32 + 8*3))));
3149 for _ in 0..pending_monitor_events_len {
3150 let ev = match <u8 as Readable>::read(reader)? {
3151 0 => MonitorEvent::HTLCEvent(Readable::read(reader)?),
3152 1 => MonitorEvent::CommitmentTxConfirmed(funding_info.0),
3153 _ => return Err(DecodeError::InvalidValue)
3155 pending_monitor_events.as_mut().unwrap().push(ev);
3158 let pending_events_len: u64 = Readable::read(reader)?;
3159 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Event>()));
3160 for _ in 0..pending_events_len {
3161 if let Some(event) = MaybeReadable::read(reader)? {
3162 pending_events.push(event);
3166 let best_block = BestBlock::new(Readable::read(reader)?, Readable::read(reader)?);
3168 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
3169 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
3170 for _ in 0..waiting_threshold_conf_len {
3171 if let Some(val) = MaybeReadable::read(reader)? {
3172 onchain_events_awaiting_threshold_conf.push(val);
3176 let outputs_to_watch_len: u64 = Readable::read(reader)?;
3177 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>>())));
3178 for _ in 0..outputs_to_watch_len {
3179 let txid = Readable::read(reader)?;
3180 let outputs_len: u64 = Readable::read(reader)?;
3181 let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / (mem::size_of::<u32>() + mem::size_of::<Script>())));
3182 for _ in 0..outputs_len {
3183 outputs.push((Readable::read(reader)?, Readable::read(reader)?));
3185 if let Some(_) = outputs_to_watch.insert(txid, outputs) {
3186 return Err(DecodeError::InvalidValue);
3189 let onchain_tx_handler: OnchainTxHandler<Signer> = ReadableArgs::read(reader, keys_manager)?;
3191 let lockdown_from_offchain = Readable::read(reader)?;
3192 let holder_tx_signed = Readable::read(reader)?;
3194 if let Some(prev_commitment_tx) = prev_holder_signed_commitment_tx.as_mut() {
3195 let prev_holder_value = onchain_tx_handler.get_prev_holder_commitment_to_self_value();
3196 if prev_holder_value.is_none() { return Err(DecodeError::InvalidValue); }
3197 if prev_commitment_tx.to_self_value_sat == u64::max_value() {
3198 prev_commitment_tx.to_self_value_sat = prev_holder_value.unwrap();
3199 } else if prev_commitment_tx.to_self_value_sat != prev_holder_value.unwrap() {
3200 return Err(DecodeError::InvalidValue);
3204 let cur_holder_value = onchain_tx_handler.get_cur_holder_commitment_to_self_value();
3205 if current_holder_commitment_tx.to_self_value_sat == u64::max_value() {
3206 current_holder_commitment_tx.to_self_value_sat = cur_holder_value;
3207 } else if current_holder_commitment_tx.to_self_value_sat != cur_holder_value {
3208 return Err(DecodeError::InvalidValue);
3211 let mut funding_spend_confirmed = None;
3212 let mut htlcs_resolved_on_chain = Some(Vec::new());
3213 read_tlv_fields!(reader, {
3214 (1, funding_spend_confirmed, option),
3215 (3, htlcs_resolved_on_chain, vec_type),
3216 (5, pending_monitor_events, vec_type),
3219 let mut secp_ctx = Secp256k1::new();
3220 secp_ctx.seeded_randomize(&keys_manager.get_secure_random_bytes());
3222 Ok((best_block.block_hash(), ChannelMonitor {
3223 inner: Mutex::new(ChannelMonitorImpl {
3225 commitment_transaction_number_obscure_factor,
3228 broadcasted_holder_revokable_script,
3229 counterparty_payment_script,
3233 holder_revocation_basepoint,
3235 current_counterparty_commitment_txid,
3236 prev_counterparty_commitment_txid,
3238 counterparty_commitment_params,
3239 funding_redeemscript,
3240 channel_value_satoshis,
3241 their_cur_revocation_points,
3246 counterparty_claimable_outpoints,
3247 counterparty_commitment_txn_on_chain,
3248 counterparty_hash_commitment_number,
3250 prev_holder_signed_commitment_tx,
3251 current_holder_commitment_tx,
3252 current_counterparty_commitment_number,
3253 current_holder_commitment_number,
3256 pending_monitor_events: pending_monitor_events.unwrap(),
3259 onchain_events_awaiting_threshold_conf,
3264 lockdown_from_offchain,
3266 funding_spend_confirmed,
3267 htlcs_resolved_on_chain: htlcs_resolved_on_chain.unwrap(),
3279 use bitcoin::blockdata::script::{Script, Builder};
3280 use bitcoin::blockdata::opcodes;
3281 use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
3282 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
3283 use bitcoin::util::bip143;
3284 use bitcoin::hashes::Hash;
3285 use bitcoin::hashes::sha256::Hash as Sha256;
3286 use bitcoin::hashes::hex::FromHex;
3287 use bitcoin::hash_types::Txid;
3288 use bitcoin::network::constants::Network;
3290 use chain::BestBlock;
3291 use chain::channelmonitor::ChannelMonitor;
3292 use chain::package::{WEIGHT_OFFERED_HTLC, WEIGHT_RECEIVED_HTLC, WEIGHT_REVOKED_OFFERED_HTLC, WEIGHT_REVOKED_RECEIVED_HTLC, WEIGHT_REVOKED_OUTPUT};
3293 use chain::transaction::OutPoint;
3294 use ln::{PaymentPreimage, PaymentHash};
3296 use ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
3297 use ln::script::ShutdownScript;
3298 use util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};
3299 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
3300 use bitcoin::secp256k1::Secp256k1;
3301 use sync::{Arc, Mutex};
3302 use chain::keysinterface::InMemorySigner;
3306 fn test_prune_preimages() {
3307 let secp_ctx = Secp256k1::new();
3308 let logger = Arc::new(TestLogger::new());
3309 let broadcaster = Arc::new(TestBroadcaster{txn_broadcasted: Mutex::new(Vec::new()), blocks: Arc::new(Mutex::new(Vec::new()))});
3310 let fee_estimator = Arc::new(TestFeeEstimator { sat_per_kw: Mutex::new(253) });
3312 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
3313 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
3315 let mut preimages = Vec::new();
3318 let preimage = PaymentPreimage([i; 32]);
3319 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
3320 preimages.push((preimage, hash));
3324 macro_rules! preimages_slice_to_htlc_outputs {
3325 ($preimages_slice: expr) => {
3327 let mut res = Vec::new();
3328 for (idx, preimage) in $preimages_slice.iter().enumerate() {
3329 res.push((HTLCOutputInCommitment {
3333 payment_hash: preimage.1.clone(),
3334 transaction_output_index: Some(idx as u32),
3341 macro_rules! preimages_to_holder_htlcs {
3342 ($preimages_slice: expr) => {
3344 let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
3345 let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
3351 macro_rules! test_preimages_exist {
3352 ($preimages_slice: expr, $monitor: expr) => {
3353 for preimage in $preimages_slice {
3354 assert!($monitor.inner.lock().unwrap().payment_preimages.contains_key(&preimage.1));
3359 let keys = InMemorySigner::new(
3361 SecretKey::from_slice(&[41; 32]).unwrap(),
3362 SecretKey::from_slice(&[41; 32]).unwrap(),
3363 SecretKey::from_slice(&[41; 32]).unwrap(),
3364 SecretKey::from_slice(&[41; 32]).unwrap(),
3365 SecretKey::from_slice(&[41; 32]).unwrap(),
3371 let counterparty_pubkeys = ChannelPublicKeys {
3372 funding_pubkey: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
3373 revocation_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
3374 payment_point: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[46; 32]).unwrap()),
3375 delayed_payment_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[47; 32]).unwrap()),
3376 htlc_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[48; 32]).unwrap())
3378 let funding_outpoint = OutPoint { txid: Default::default(), index: u16::max_value() };
3379 let channel_parameters = ChannelTransactionParameters {
3380 holder_pubkeys: keys.holder_channel_pubkeys.clone(),
3381 holder_selected_contest_delay: 66,
3382 is_outbound_from_holder: true,
3383 counterparty_parameters: Some(CounterpartyChannelTransactionParameters {
3384 pubkeys: counterparty_pubkeys,
3385 selected_contest_delay: 67,
3387 funding_outpoint: Some(funding_outpoint),
3389 // Prune with one old state and a holder commitment tx holding a few overlaps with the
3391 let shutdown_pubkey = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
3392 let best_block = BestBlock::from_genesis(Network::Testnet);
3393 let monitor = ChannelMonitor::new(Secp256k1::new(), keys,
3394 Some(ShutdownScript::new_p2wpkh_from_pubkey(shutdown_pubkey).into_inner()), 0, &Script::new(),
3395 (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
3396 &channel_parameters,
3397 Script::new(), 46, 0,
3398 HolderCommitmentTransaction::dummy(), best_block);
3400 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..10])).unwrap();
3401 let dummy_txid = dummy_tx.txid();
3402 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
3403 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
3404 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
3405 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
3406 for &(ref preimage, ref hash) in preimages.iter() {
3407 monitor.provide_payment_preimage(hash, preimage, &broadcaster, &fee_estimator, &logger);
3410 // Now provide a secret, pruning preimages 10-15
3411 let mut secret = [0; 32];
3412 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
3413 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
3414 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 15);
3415 test_preimages_exist!(&preimages[0..10], monitor);
3416 test_preimages_exist!(&preimages[15..20], monitor);
3418 // Now provide a further secret, pruning preimages 15-17
3419 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
3420 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
3421 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 13);
3422 test_preimages_exist!(&preimages[0..10], monitor);
3423 test_preimages_exist!(&preimages[17..20], monitor);
3425 // Now update holder commitment tx info, pruning only element 18 as we still care about the
3426 // previous commitment tx's preimages too
3427 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..5])).unwrap();
3428 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
3429 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
3430 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 12);
3431 test_preimages_exist!(&preimages[0..10], monitor);
3432 test_preimages_exist!(&preimages[18..20], monitor);
3434 // But if we do it again, we'll prune 5-10
3435 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..3])).unwrap();
3436 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
3437 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
3438 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 5);
3439 test_preimages_exist!(&preimages[0..5], monitor);
3443 fn test_claim_txn_weight_computation() {
3444 // We test Claim txn weight, knowing that we want expected weigth and
3445 // not actual case to avoid sigs and time-lock delays hell variances.
3447 let secp_ctx = Secp256k1::new();
3448 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
3449 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
3450 let mut sum_actual_sigs = 0;
3452 macro_rules! sign_input {
3453 ($sighash_parts: expr, $idx: expr, $amount: expr, $weight: expr, $sum_actual_sigs: expr) => {
3454 let htlc = HTLCOutputInCommitment {
3455 offered: if *$weight == WEIGHT_REVOKED_OFFERED_HTLC || *$weight == WEIGHT_OFFERED_HTLC { true } else { false },
3457 cltv_expiry: 2 << 16,
3458 payment_hash: PaymentHash([1; 32]),
3459 transaction_output_index: Some($idx as u32),
3461 let redeem_script = if *$weight == WEIGHT_REVOKED_OUTPUT { chan_utils::get_revokeable_redeemscript(&pubkey, 256, &pubkey) } else { chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &pubkey, &pubkey, &pubkey) };
3462 let sighash = hash_to_message!(&$sighash_parts.signature_hash($idx, &redeem_script, $amount, SigHashType::All)[..]);
3463 let sig = secp_ctx.sign(&sighash, &privkey);
3464 $sighash_parts.access_witness($idx).push(sig.serialize_der().to_vec());
3465 $sighash_parts.access_witness($idx)[0].push(SigHashType::All as u8);
3466 sum_actual_sigs += $sighash_parts.access_witness($idx)[0].len();
3467 if *$weight == WEIGHT_REVOKED_OUTPUT {
3468 $sighash_parts.access_witness($idx).push(vec!(1));
3469 } else if *$weight == WEIGHT_REVOKED_OFFERED_HTLC || *$weight == WEIGHT_REVOKED_RECEIVED_HTLC {
3470 $sighash_parts.access_witness($idx).push(pubkey.clone().serialize().to_vec());
3471 } else if *$weight == WEIGHT_RECEIVED_HTLC {
3472 $sighash_parts.access_witness($idx).push(vec![0]);
3474 $sighash_parts.access_witness($idx).push(PaymentPreimage([1; 32]).0.to_vec());
3476 $sighash_parts.access_witness($idx).push(redeem_script.into_bytes());
3477 println!("witness[0] {}", $sighash_parts.access_witness($idx)[0].len());
3478 println!("witness[1] {}", $sighash_parts.access_witness($idx)[1].len());
3479 println!("witness[2] {}", $sighash_parts.access_witness($idx)[2].len());
3483 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
3484 let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
3486 // Justice tx with 1 to_holder, 2 revoked offered HTLCs, 1 revoked received HTLCs
3487 let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
3489 claim_tx.input.push(TxIn {
3490 previous_output: BitcoinOutPoint {
3494 script_sig: Script::new(),
3495 sequence: 0xfffffffd,
3496 witness: Vec::new(),
3499 claim_tx.output.push(TxOut {
3500 script_pubkey: script_pubkey.clone(),
3503 let base_weight = claim_tx.get_weight();
3504 let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT, WEIGHT_REVOKED_OFFERED_HTLC, WEIGHT_REVOKED_OFFERED_HTLC, WEIGHT_REVOKED_RECEIVED_HTLC];
3505 let mut inputs_total_weight = 2; // count segwit flags
3507 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
3508 for (idx, inp) in inputs_weight.iter().enumerate() {
3509 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
3510 inputs_total_weight += inp;
3513 assert_eq!(base_weight + inputs_total_weight as usize, claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
3515 // Claim tx with 1 offered HTLCs, 3 received HTLCs
3516 claim_tx.input.clear();
3517 sum_actual_sigs = 0;
3519 claim_tx.input.push(TxIn {
3520 previous_output: BitcoinOutPoint {
3524 script_sig: Script::new(),
3525 sequence: 0xfffffffd,
3526 witness: Vec::new(),
3529 let base_weight = claim_tx.get_weight();
3530 let inputs_weight = vec![WEIGHT_OFFERED_HTLC, WEIGHT_RECEIVED_HTLC, WEIGHT_RECEIVED_HTLC, WEIGHT_RECEIVED_HTLC];
3531 let mut inputs_total_weight = 2; // count segwit flags
3533 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
3534 for (idx, inp) in inputs_weight.iter().enumerate() {
3535 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
3536 inputs_total_weight += inp;
3539 assert_eq!(base_weight + inputs_total_weight as usize, claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
3541 // Justice tx with 1 revoked HTLC-Success tx output
3542 claim_tx.input.clear();
3543 sum_actual_sigs = 0;
3544 claim_tx.input.push(TxIn {
3545 previous_output: BitcoinOutPoint {
3549 script_sig: Script::new(),
3550 sequence: 0xfffffffd,
3551 witness: Vec::new(),
3553 let base_weight = claim_tx.get_weight();
3554 let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT];
3555 let mut inputs_total_weight = 2; // count segwit flags
3557 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
3558 for (idx, inp) in inputs_weight.iter().enumerate() {
3559 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
3560 inputs_total_weight += inp;
3563 assert_eq!(base_weight + inputs_total_weight as usize, claim_tx.get_weight() + /* max_length_isg */ (73 * inputs_weight.len() - sum_actual_sigs));
3566 // Further testing is done in the ChannelManager integration tests.