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 build claims and bump in-flight transactions until confirmations.
12 //! OnchainTxHandler objects are fully-part of ChannelMonitor and encapsulates all
13 //! building, tracking, bumping and notifications functions.
15 use bitcoin::blockdata::locktime::absolute::LockTime;
16 use bitcoin::blockdata::transaction::Transaction;
17 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
18 use bitcoin::blockdata::script::{Script, ScriptBuf};
19 use bitcoin::hashes::{Hash, HashEngine};
20 use bitcoin::hashes::sha256::Hash as Sha256;
21 use bitcoin::hash_types::{Txid, BlockHash};
22 use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature};
23 use bitcoin::secp256k1;
25 use crate::chain::chaininterface::compute_feerate_sat_per_1000_weight;
26 use crate::sign::{ChannelDerivationParameters, HTLCDescriptor, ChannelSigner, EntropySource, SignerProvider, ecdsa::WriteableEcdsaChannelSigner};
27 use crate::ln::msgs::DecodeError;
28 use crate::ln::PaymentPreimage;
29 use crate::ln::chan_utils::{self, ChannelTransactionParameters, HTLCOutputInCommitment, HolderCommitmentTransaction};
30 use crate::chain::ClaimId;
31 use crate::chain::chaininterface::{ConfirmationTarget, FeeEstimator, BroadcasterInterface, LowerBoundedFeeEstimator};
32 use crate::chain::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER};
33 use crate::chain::package::{PackageSolvingData, PackageTemplate};
34 use crate::util::logger::Logger;
35 use crate::util::ser::{Readable, ReadableArgs, MaybeReadable, UpgradableRequired, Writer, Writeable, VecWriter};
38 use crate::prelude::*;
39 use alloc::collections::BTreeMap;
42 use core::mem::replace;
44 use crate::ln::features::ChannelTypeFeatures;
46 const MAX_ALLOC_SIZE: usize = 64*1024;
48 /// An entry for an [`OnchainEvent`], stating the block height when the event was observed and the
49 /// transaction causing it.
51 /// Used to determine when the on-chain event can be considered safe from a chain reorganization.
52 #[derive(Clone, PartialEq, Eq)]
53 struct OnchainEventEntry {
56 block_hash: Option<BlockHash>, // Added as optional, will be filled in for any entry generated on 0.0.113 or after
60 impl OnchainEventEntry {
61 fn confirmation_threshold(&self) -> u32 {
62 self.height + ANTI_REORG_DELAY - 1
65 fn has_reached_confirmation_threshold(&self, height: u32) -> bool {
66 height >= self.confirmation_threshold()
70 /// Events for claims the [`OnchainTxHandler`] has generated. Once the events are considered safe
71 /// from a chain reorg, the [`OnchainTxHandler`] will act accordingly.
72 #[derive(Clone, PartialEq, Eq)]
74 /// A pending request has been claimed by a transaction spending the exact same set of outpoints
75 /// as the request. This claim can either be ours or from the counterparty. Once the claiming
76 /// transaction has met [`ANTI_REORG_DELAY`] confirmations, we consider it final and remove the
81 /// The counterparty has claimed an outpoint from one of our pending requests through a
82 /// different transaction than ours. If our transaction was attempting to claim multiple
83 /// outputs, we need to drop the outpoint claimed by the counterparty and regenerate a new claim
84 /// transaction for ourselves. We keep tracking, separately, the outpoint claimed by the
85 /// counterparty up to [`ANTI_REORG_DELAY`] confirmations to ensure we attempt to re-claim it
86 /// if the counterparty's claim is reorged from the chain.
88 package: PackageTemplate,
92 impl Writeable for OnchainEventEntry {
93 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
94 write_tlv_fields!(writer, {
95 (0, self.txid, required),
96 (1, self.block_hash, option),
97 (2, self.height, required),
98 (4, self.event, required),
104 impl MaybeReadable for OnchainEventEntry {
105 fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, DecodeError> {
106 let mut txid = Txid::all_zeros();
108 let mut block_hash = None;
109 let mut event = UpgradableRequired(None);
110 read_tlv_fields!(reader, {
112 (1, block_hash, option),
113 (2, height, required),
114 (4, event, upgradable_required),
116 Ok(Some(Self { txid, height, block_hash, event: _init_tlv_based_struct_field!(event, upgradable_required) }))
120 impl_writeable_tlv_based_enum_upgradable!(OnchainEvent,
122 (0, claim_id, required),
124 (1, ContentiousOutpoint) => {
125 (0, package, required),
129 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
130 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
131 match Readable::read(reader)? {
134 let vlen: u64 = Readable::read(reader)?;
135 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::core::mem::size_of::<Option<(usize, Signature)>>()));
137 ret.push(match Readable::read(reader)? {
139 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
140 _ => return Err(DecodeError::InvalidValue)
145 _ => Err(DecodeError::InvalidValue),
150 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
151 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
155 (vec.len() as u64).write(writer)?;
156 for opt in vec.iter() {
158 &Some((ref idx, ref sig)) => {
160 (*idx as u64).write(writer)?;
163 &None => 0u8.write(writer)?,
167 &None => 0u8.write(writer)?,
173 /// The claim commonly referred to as the pre-signed second-stage HTLC transaction.
174 #[derive(Clone, PartialEq, Eq)]
175 pub(crate) struct ExternalHTLCClaim {
176 pub(crate) commitment_txid: Txid,
177 pub(crate) per_commitment_number: u64,
178 pub(crate) htlc: HTLCOutputInCommitment,
179 pub(crate) preimage: Option<PaymentPreimage>,
180 pub(crate) counterparty_sig: Signature,
183 // Represents the different types of claims for which events are yielded externally to satisfy said
185 #[derive(Clone, PartialEq, Eq)]
186 pub(crate) enum ClaimEvent {
187 /// Event yielded to signal that the commitment transaction fee must be bumped to claim any
188 /// encumbered funds and proceed to HTLC resolution, if any HTLCs exist.
190 package_target_feerate_sat_per_1000_weight: u32,
191 commitment_tx: Transaction,
192 anchor_output_idx: u32,
194 /// Event yielded to signal that the commitment transaction has confirmed and its HTLCs must be
195 /// resolved by broadcasting a transaction with sufficient fee to claim them.
197 target_feerate_sat_per_1000_weight: u32,
198 htlcs: Vec<ExternalHTLCClaim>,
199 tx_lock_time: LockTime,
203 /// Represents the different ways an output can be claimed (i.e., spent to an address under our
204 /// control) onchain.
205 pub(crate) enum OnchainClaim {
206 /// A finalized transaction pending confirmation spending the output to claim.
208 /// An event yielded externally to signal additional inputs must be added to a transaction
209 /// pending confirmation spending the output to claim.
213 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
214 /// do RBF bumping if possible.
216 pub struct OnchainTxHandler<ChannelSigner: WriteableEcdsaChannelSigner> {
217 channel_value_satoshis: u64,
218 channel_keys_id: [u8; 32],
219 destination_script: ScriptBuf,
220 holder_commitment: HolderCommitmentTransaction,
221 prev_holder_commitment: Option<HolderCommitmentTransaction>,
223 pub(super) signer: ChannelSigner,
224 pub(crate) channel_transaction_parameters: ChannelTransactionParameters,
226 // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
227 // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
228 // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
229 // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
230 // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
231 // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
232 // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
233 // we need to regenerate new claim request with reduced set of still-claimable outpoints.
234 // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
235 // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
236 // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
237 #[cfg(test)] // Used in functional_test to verify sanitization
238 pub(crate) pending_claim_requests: HashMap<ClaimId, PackageTemplate>,
240 pending_claim_requests: HashMap<ClaimId, PackageTemplate>,
242 // Used to track external events that need to be forwarded to the `ChainMonitor`. This `Vec`
243 // essentially acts as an insertion-ordered `HashMap` – there should only ever be one occurrence
244 // of a `ClaimId`, which tracks its latest `ClaimEvent`, i.e., if a pending claim exists, and
245 // a new block has been connected, resulting in a new claim, the previous will be replaced with
248 // These external events may be generated in the following cases:
249 // - A channel has been force closed by broadcasting the holder's latest commitment transaction
250 // - A block being connected/disconnected
251 // - Learning the preimage for an HTLC we can claim onchain
252 pending_claim_events: Vec<(ClaimId, ClaimEvent)>,
254 // Used to link outpoints claimed in a connected block to a pending claim request. The keys
255 // represent the outpoints that our `ChannelMonitor` has detected we have keys/scripts to
256 // claim. The values track the pending claim request identifier and the initial confirmation
257 // block height, and are immutable until the outpoint has enough confirmations to meet our
258 // [`ANTI_REORG_DELAY`]. The initial confirmation block height is used to remove the entry if
259 // the block gets disconnected.
260 #[cfg(test)] // Used in functional_test to verify sanitization
261 pub claimable_outpoints: HashMap<BitcoinOutPoint, (ClaimId, u32)>,
263 claimable_outpoints: HashMap<BitcoinOutPoint, (ClaimId, u32)>,
265 locktimed_packages: BTreeMap<u32, Vec<PackageTemplate>>,
267 onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
269 pub(super) secp_ctx: Secp256k1<secp256k1::All>,
272 impl<ChannelSigner: WriteableEcdsaChannelSigner> PartialEq for OnchainTxHandler<ChannelSigner> {
273 fn eq(&self, other: &Self) -> bool {
274 // `signer`, `secp_ctx`, and `pending_claim_events` are excluded on purpose.
275 self.channel_value_satoshis == other.channel_value_satoshis &&
276 self.channel_keys_id == other.channel_keys_id &&
277 self.destination_script == other.destination_script &&
278 self.holder_commitment == other.holder_commitment &&
279 self.prev_holder_commitment == other.prev_holder_commitment &&
280 self.channel_transaction_parameters == other.channel_transaction_parameters &&
281 self.pending_claim_requests == other.pending_claim_requests &&
282 self.claimable_outpoints == other.claimable_outpoints &&
283 self.locktimed_packages == other.locktimed_packages &&
284 self.onchain_events_awaiting_threshold_conf == other.onchain_events_awaiting_threshold_conf
288 const SERIALIZATION_VERSION: u8 = 1;
289 const MIN_SERIALIZATION_VERSION: u8 = 1;
291 impl<ChannelSigner: WriteableEcdsaChannelSigner> OnchainTxHandler<ChannelSigner> {
292 pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
293 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
295 self.destination_script.write(writer)?;
296 self.holder_commitment.write(writer)?;
297 None::<Option<Vec<Option<(usize, Signature)>>>>.write(writer)?; // holder_htlc_sigs
298 self.prev_holder_commitment.write(writer)?;
299 None::<Option<Vec<Option<(usize, Signature)>>>>.write(writer)?; // prev_holder_htlc_sigs
301 self.channel_transaction_parameters.write(writer)?;
303 let mut key_data = VecWriter(Vec::new());
304 self.signer.write(&mut key_data)?;
305 assert!(key_data.0.len() < core::usize::MAX);
306 assert!(key_data.0.len() < core::u32::MAX as usize);
307 (key_data.0.len() as u32).write(writer)?;
308 writer.write_all(&key_data.0[..])?;
310 writer.write_all(&(self.pending_claim_requests.len() as u64).to_be_bytes())?;
311 for (ref ancestor_claim_txid, request) in self.pending_claim_requests.iter() {
312 ancestor_claim_txid.write(writer)?;
313 request.write(writer)?;
316 writer.write_all(&(self.claimable_outpoints.len() as u64).to_be_bytes())?;
317 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
319 claim_and_height.0.write(writer)?;
320 claim_and_height.1.write(writer)?;
323 writer.write_all(&(self.locktimed_packages.len() as u64).to_be_bytes())?;
324 for (ref locktime, ref packages) in self.locktimed_packages.iter() {
325 locktime.write(writer)?;
326 writer.write_all(&(packages.len() as u64).to_be_bytes())?;
327 for ref package in packages.iter() {
328 package.write(writer)?;
332 writer.write_all(&(self.onchain_events_awaiting_threshold_conf.len() as u64).to_be_bytes())?;
333 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
334 entry.write(writer)?;
337 write_tlv_fields!(writer, {});
342 impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP, u64, [u8; 32])> for OnchainTxHandler<SP::EcdsaSigner> {
343 fn read<R: io::Read>(reader: &mut R, args: (&'a ES, &'b SP, u64, [u8; 32])) -> Result<Self, DecodeError> {
344 let entropy_source = args.0;
345 let signer_provider = args.1;
346 let channel_value_satoshis = args.2;
347 let channel_keys_id = args.3;
349 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
351 let destination_script = Readable::read(reader)?;
353 let holder_commitment = Readable::read(reader)?;
354 let _holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>> = Readable::read(reader)?;
355 let prev_holder_commitment = Readable::read(reader)?;
356 let _prev_holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>> = Readable::read(reader)?;
358 let channel_parameters = Readable::read(reader)?;
360 // Read the serialized signer bytes, but don't deserialize them, as we'll obtain our signer
361 // by re-deriving the private key material.
362 let keys_len: u32 = Readable::read(reader)?;
363 let mut bytes_read = 0;
364 while bytes_read != keys_len as usize {
365 // Read 1KB at a time to avoid accidentally allocating 4GB on corrupted channel keys
366 let mut data = [0; 1024];
367 let bytes_to_read = cmp::min(1024, keys_len as usize - bytes_read);
368 let read_slice = &mut data[0..bytes_to_read];
369 reader.read_exact(read_slice)?;
370 bytes_read += bytes_to_read;
373 let mut signer = signer_provider.derive_channel_signer(channel_value_satoshis, channel_keys_id);
374 signer.provide_channel_parameters(&channel_parameters);
376 let pending_claim_requests_len: u64 = Readable::read(reader)?;
377 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
378 for _ in 0..pending_claim_requests_len {
379 pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
382 let claimable_outpoints_len: u64 = Readable::read(reader)?;
383 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
384 for _ in 0..claimable_outpoints_len {
385 let outpoint = Readable::read(reader)?;
386 let ancestor_claim_txid = Readable::read(reader)?;
387 let height = Readable::read(reader)?;
388 claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
391 let locktimed_packages_len: u64 = Readable::read(reader)?;
392 let mut locktimed_packages = BTreeMap::new();
393 for _ in 0..locktimed_packages_len {
394 let locktime = Readable::read(reader)?;
395 let packages_len: u64 = Readable::read(reader)?;
396 let mut packages = Vec::with_capacity(cmp::min(packages_len as usize, MAX_ALLOC_SIZE / core::mem::size_of::<PackageTemplate>()));
397 for _ in 0..packages_len {
398 packages.push(Readable::read(reader)?);
400 locktimed_packages.insert(locktime, packages);
403 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
404 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
405 for _ in 0..waiting_threshold_conf_len {
406 if let Some(val) = MaybeReadable::read(reader)? {
407 onchain_events_awaiting_threshold_conf.push(val);
411 read_tlv_fields!(reader, {});
413 let mut secp_ctx = Secp256k1::new();
414 secp_ctx.seeded_randomize(&entropy_source.get_secure_random_bytes());
416 Ok(OnchainTxHandler {
417 channel_value_satoshis,
421 prev_holder_commitment,
423 channel_transaction_parameters: channel_parameters,
426 pending_claim_requests,
427 onchain_events_awaiting_threshold_conf,
428 pending_claim_events: Vec::new(),
434 impl<ChannelSigner: WriteableEcdsaChannelSigner> OnchainTxHandler<ChannelSigner> {
436 channel_value_satoshis: u64, channel_keys_id: [u8; 32], destination_script: ScriptBuf,
437 signer: ChannelSigner, channel_parameters: ChannelTransactionParameters,
438 holder_commitment: HolderCommitmentTransaction, secp_ctx: Secp256k1<secp256k1::All>
441 channel_value_satoshis,
445 prev_holder_commitment: None,
447 channel_transaction_parameters: channel_parameters,
448 pending_claim_requests: HashMap::new(),
449 claimable_outpoints: HashMap::new(),
450 locktimed_packages: BTreeMap::new(),
451 onchain_events_awaiting_threshold_conf: Vec::new(),
452 pending_claim_events: Vec::new(),
457 pub(crate) fn get_prev_holder_commitment_to_self_value(&self) -> Option<u64> {
458 self.prev_holder_commitment.as_ref().map(|commitment| commitment.to_broadcaster_value_sat())
461 pub(crate) fn get_cur_holder_commitment_to_self_value(&self) -> u64 {
462 self.holder_commitment.to_broadcaster_value_sat()
465 pub(crate) fn get_and_clear_pending_claim_events(&mut self) -> Vec<(ClaimId, ClaimEvent)> {
466 let mut events = Vec::new();
467 swap(&mut events, &mut self.pending_claim_events);
471 /// Triggers rebroadcasts/fee-bumps of pending claims from a force-closed channel. This is
472 /// crucial in preventing certain classes of pinning attacks, detecting substantial mempool
473 /// feerate changes between blocks, and ensuring reliability if broadcasting fails. We recommend
474 /// invoking this every 30 seconds, or lower if running in an environment with spotty
475 /// connections, like on mobile.
476 pub(super) fn rebroadcast_pending_claims<B: Deref, F: Deref, L: Logger>(
477 &mut self, current_height: u32, broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>,
481 B::Target: BroadcasterInterface,
482 F::Target: FeeEstimator,
484 let mut bump_requests = Vec::with_capacity(self.pending_claim_requests.len());
485 for (claim_id, request) in self.pending_claim_requests.iter() {
486 let inputs = request.outpoints();
487 log_info!(logger, "Triggering rebroadcast/fee-bump for request with inputs {:?}", inputs);
488 bump_requests.push((*claim_id, request.clone()));
490 for (claim_id, request) in bump_requests {
491 self.generate_claim(current_height, &request, false /* force_feerate_bump */, fee_estimator, logger)
492 .map(|(_, new_feerate, claim)| {
493 let mut bumped_feerate = false;
494 if let Some(mut_request) = self.pending_claim_requests.get_mut(&claim_id) {
495 bumped_feerate = request.previous_feerate() > new_feerate;
496 mut_request.set_feerate(new_feerate);
499 OnchainClaim::Tx(tx) => {
500 let log_start = if bumped_feerate { "Broadcasting RBF-bumped" } else { "Rebroadcasting" };
501 log_info!(logger, "{} onchain {}", log_start, log_tx!(tx));
502 broadcaster.broadcast_transactions(&[&tx]);
504 OnchainClaim::Event(event) => {
505 let log_start = if bumped_feerate { "Yielding fee-bumped" } else { "Replaying" };
506 log_info!(logger, "{} onchain event to spend inputs {:?}", log_start,
507 request.outpoints());
508 #[cfg(debug_assertions)] {
509 debug_assert!(request.requires_external_funding());
510 let num_existing = self.pending_claim_events.iter()
511 .filter(|entry| entry.0 == claim_id).count();
512 assert!(num_existing == 0 || num_existing == 1);
514 self.pending_claim_events.retain(|event| event.0 != claim_id);
515 self.pending_claim_events.push((claim_id, event));
522 /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize counterparty
523 /// onchain) lays on the assumption of claim transactions getting confirmed before timelock
524 /// expiration (CSV or CLTV following cases). In case of high-fee spikes, claim tx may get stuck
525 /// in the mempool, so you need to bump its feerate quickly using Replace-By-Fee or
526 /// Child-Pay-For-Parent.
528 /// Panics if there are signing errors, because signing operations in reaction to on-chain
529 /// events are not expected to fail, and if they do, we may lose funds.
530 fn generate_claim<F: Deref, L: Logger>(
531 &mut self, cur_height: u32, cached_request: &PackageTemplate, force_feerate_bump: bool,
532 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L,
533 ) -> Option<(u32, u64, OnchainClaim)>
534 where F::Target: FeeEstimator,
536 let request_outpoints = cached_request.outpoints();
537 if request_outpoints.is_empty() {
538 // Don't prune pending claiming request yet, we may have to resurrect HTLCs. Untractable
539 // packages cannot be aggregated and will never be split, so we cannot end up with an
541 debug_assert!(cached_request.is_malleable());
544 // If we've seen transaction inclusion in the chain for all outpoints in our request, we
545 // don't need to continue generating more claims. We'll keep tracking the request to fully
546 // remove it once it reaches the confirmation threshold, or to generate a new claim if the
547 // transaction is reorged out.
548 let mut all_inputs_have_confirmed_spend = true;
549 for outpoint in request_outpoints.iter() {
550 if let Some((request_claim_id, _)) = self.claimable_outpoints.get(*outpoint) {
551 // We check for outpoint spends within claims individually rather than as a set
552 // since requests can have outpoints split off.
553 if !self.onchain_events_awaiting_threshold_conf.iter()
554 .any(|event_entry| if let OnchainEvent::Claim { claim_id } = event_entry.event {
555 *request_claim_id == claim_id
557 // The onchain event is not a claim, keep seeking until we find one.
561 // Either we had no `OnchainEvent::Claim`, or we did but none matched the
562 // outpoint's registered spend.
563 all_inputs_have_confirmed_spend = false;
566 // The request's outpoint spend does not exist yet.
567 all_inputs_have_confirmed_spend = false;
570 if all_inputs_have_confirmed_spend {
574 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
575 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
576 let new_timer = cached_request.get_height_timer(cur_height);
577 if cached_request.is_malleable() {
578 if cached_request.requires_external_funding() {
579 let target_feerate_sat_per_1000_weight = cached_request.compute_package_feerate(
580 fee_estimator, ConfirmationTarget::OnChainSweep, force_feerate_bump
582 if let Some(htlcs) = cached_request.construct_malleable_package_with_external_funding(self) {
585 target_feerate_sat_per_1000_weight as u64,
586 OnchainClaim::Event(ClaimEvent::BumpHTLC {
587 target_feerate_sat_per_1000_weight,
589 tx_lock_time: LockTime::from_consensus(cached_request.package_locktime(cur_height)),
597 let predicted_weight = cached_request.package_weight(&self.destination_script);
598 if let Some((output_value, new_feerate)) = cached_request.compute_package_output(
599 predicted_weight, self.destination_script.dust_value().to_sat(),
600 force_feerate_bump, fee_estimator, logger,
602 assert!(new_feerate != 0);
604 let transaction = cached_request.finalize_malleable_package(
605 cur_height, self, output_value, self.destination_script.clone(), logger
607 log_trace!(logger, "...with timer {} and feerate {}", new_timer, new_feerate);
608 assert!(predicted_weight >= transaction.weight().to_wu());
609 return Some((new_timer, new_feerate, OnchainClaim::Tx(transaction)));
612 // Untractable packages cannot have their fees bumped through Replace-By-Fee. Some
613 // packages may support fee bumping through Child-Pays-For-Parent, indicated by those
614 // which require external funding.
615 let mut inputs = cached_request.inputs();
616 debug_assert_eq!(inputs.len(), 1);
617 let tx = match cached_request.finalize_untractable_package(self, logger) {
621 if !cached_request.requires_external_funding() {
622 return Some((new_timer, 0, OnchainClaim::Tx(tx)));
624 return inputs.find_map(|input| match input {
625 // Commitment inputs with anchors support are the only untractable inputs supported
626 // thus far that require external funding.
627 PackageSolvingData::HolderFundingOutput(output) => {
628 debug_assert_eq!(tx.txid(), self.holder_commitment.trust().txid(),
629 "Holder commitment transaction mismatch");
631 let conf_target = ConfirmationTarget::OnChainSweep;
632 let package_target_feerate_sat_per_1000_weight = cached_request
633 .compute_package_feerate(fee_estimator, conf_target, force_feerate_bump);
634 if let Some(input_amount_sat) = output.funding_amount {
635 let fee_sat = input_amount_sat - tx.output.iter().map(|output| output.value).sum::<u64>();
636 let commitment_tx_feerate_sat_per_1000_weight =
637 compute_feerate_sat_per_1000_weight(fee_sat, tx.weight().to_wu());
638 if commitment_tx_feerate_sat_per_1000_weight >= package_target_feerate_sat_per_1000_weight {
639 log_debug!(logger, "Pre-signed {} already has feerate {} sat/kW above required {} sat/kW",
640 log_tx!(tx), commitment_tx_feerate_sat_per_1000_weight,
641 package_target_feerate_sat_per_1000_weight);
642 return Some((new_timer, 0, OnchainClaim::Tx(tx.clone())));
646 // We'll locate an anchor output we can spend within the commitment transaction.
647 let funding_pubkey = &self.channel_transaction_parameters.holder_pubkeys.funding_pubkey;
648 match chan_utils::get_anchor_output(&tx, funding_pubkey) {
649 // An anchor output was found, so we should yield a funding event externally.
651 // TODO: Use a lower confirmation target when both our and the
652 // counterparty's latest commitment don't have any HTLCs present.
655 package_target_feerate_sat_per_1000_weight as u64,
656 OnchainClaim::Event(ClaimEvent::BumpCommitment {
657 package_target_feerate_sat_per_1000_weight,
658 commitment_tx: tx.clone(),
659 anchor_output_idx: idx,
663 // An anchor output was not found. There's nothing we can do other than
664 // attempt to broadcast the transaction with its current fee rate and hope
665 // it confirms. This is essentially the same behavior as a commitment
666 // transaction without anchor outputs.
667 None => Some((new_timer, 0, OnchainClaim::Tx(tx.clone()))),
671 debug_assert!(false, "Only HolderFundingOutput inputs should be untractable and require external funding");
679 /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
680 /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
681 /// Together with `update_claims_view_from_matched_txn` this used to be named
682 /// `block_connected`, but it is now also used for claiming an HTLC output if we receive a
683 /// preimage after force-close.
685 /// `conf_height` represents the height at which the request was generated. This
686 /// does not need to equal the current blockchain tip height, which should be provided via
687 /// `cur_height`, however it must never be higher than `cur_height`.
688 pub(super) fn update_claims_view_from_requests<B: Deref, F: Deref, L: Logger>(
689 &mut self, requests: Vec<PackageTemplate>, conf_height: u32, cur_height: u32,
690 broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L
692 B::Target: BroadcasterInterface,
693 F::Target: FeeEstimator,
695 log_debug!(logger, "Updating claims view at height {} with {} claim requests", cur_height, requests.len());
696 let mut preprocessed_requests = Vec::with_capacity(requests.len());
697 let mut aggregated_request = None;
699 // Try to aggregate outputs if their timelock expiration isn't imminent (package timelock
700 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
701 for req in requests {
702 // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
703 if let Some(_) = self.claimable_outpoints.get(req.outpoints()[0]) {
704 log_info!(logger, "Ignoring second claim for outpoint {}:{}, already registered its claiming request", req.outpoints()[0].txid, req.outpoints()[0].vout);
706 let timelocked_equivalent_package = self.locktimed_packages.iter().map(|v| v.1.iter()).flatten()
707 .find(|locked_package| locked_package.outpoints() == req.outpoints());
708 if let Some(package) = timelocked_equivalent_package {
709 log_info!(logger, "Ignoring second claim for outpoint {}:{}, we already have one which we're waiting on a timelock at {} for.",
710 req.outpoints()[0].txid, req.outpoints()[0].vout, package.package_locktime(cur_height));
714 let package_locktime = req.package_locktime(cur_height);
715 if package_locktime > cur_height + 1 {
716 log_info!(logger, "Delaying claim of package until its timelock at {} (current height {}), the following outpoints are spent:", package_locktime, cur_height);
717 for outpoint in req.outpoints() {
718 log_info!(logger, " Outpoint {}", outpoint);
720 self.locktimed_packages.entry(package_locktime).or_insert(Vec::new()).push(req);
724 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.timelock(), cur_height + CLTV_SHARED_CLAIM_BUFFER);
725 if req.timelock() <= cur_height + CLTV_SHARED_CLAIM_BUFFER || !req.aggregable() {
726 // Don't aggregate if outpoint package timelock is soon or marked as non-aggregable
727 preprocessed_requests.push(req);
728 } else if aggregated_request.is_none() {
729 aggregated_request = Some(req);
731 aggregated_request.as_mut().unwrap().merge_package(req);
735 if let Some(req) = aggregated_request {
736 preprocessed_requests.push(req);
739 // Claim everything up to and including `cur_height`
740 let remaining_locked_packages = self.locktimed_packages.split_off(&(cur_height + 1));
741 for (pop_height, mut entry) in self.locktimed_packages.iter_mut() {
742 log_trace!(logger, "Restoring delayed claim of package(s) at their timelock at {}.", pop_height);
743 preprocessed_requests.append(&mut entry);
745 self.locktimed_packages = remaining_locked_packages;
747 // Generate claim transactions and track them to bump if necessary at
748 // height timer expiration (i.e in how many blocks we're going to take action).
749 for mut req in preprocessed_requests {
750 if let Some((new_timer, new_feerate, claim)) = self.generate_claim(
751 cur_height, &req, true /* force_feerate_bump */, &*fee_estimator, &*logger,
753 req.set_timer(new_timer);
754 req.set_feerate(new_feerate);
755 // Once a pending claim has an id assigned, it remains fixed until the claim is
756 // satisfied, regardless of whether the claim switches between different variants of
758 let claim_id = match claim {
759 OnchainClaim::Tx(tx) => {
760 log_info!(logger, "Broadcasting onchain {}", log_tx!(tx));
761 broadcaster.broadcast_transactions(&[&tx]);
762 ClaimId(tx.txid().to_byte_array())
764 OnchainClaim::Event(claim_event) => {
765 log_info!(logger, "Yielding onchain event to spend inputs {:?}", req.outpoints());
766 let claim_id = match claim_event {
767 ClaimEvent::BumpCommitment { ref commitment_tx, .. } =>
768 // For commitment claims, we can just use their txid as it should
769 // already be unique.
770 ClaimId(commitment_tx.txid().to_byte_array()),
771 ClaimEvent::BumpHTLC { ref htlcs, .. } => {
772 // For HTLC claims, commit to the entire set of HTLC outputs to
773 // claim, which will always be unique per request. Once a claim ID
774 // is generated, it is assigned and remains unchanged, even if the
775 // underlying set of HTLCs changes.
776 let mut engine = Sha256::engine();
778 engine.input(&htlc.commitment_txid.to_byte_array());
779 engine.input(&htlc.htlc.transaction_output_index.unwrap().to_be_bytes());
781 ClaimId(Sha256::from_engine(engine).to_byte_array())
784 debug_assert!(self.pending_claim_requests.get(&claim_id).is_none());
785 debug_assert_eq!(self.pending_claim_events.iter().filter(|entry| entry.0 == claim_id).count(), 0);
786 self.pending_claim_events.push((claim_id, claim_event));
790 debug_assert!(self.pending_claim_requests.get(&claim_id).is_none());
791 for k in req.outpoints() {
792 log_info!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
793 self.claimable_outpoints.insert(k.clone(), (claim_id, conf_height));
795 self.pending_claim_requests.insert(claim_id, req);
800 /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
801 /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
802 /// Together with `update_claims_view_from_requests` this used to be named `block_connected`,
803 /// but it is now also used for claiming an HTLC output if we receive a preimage after force-close.
805 /// `conf_height` represents the height at which the transactions in `txn_matched` were
806 /// confirmed. This does not need to equal the current blockchain tip height, which should be
807 /// provided via `cur_height`, however it must never be higher than `cur_height`.
808 pub(super) fn update_claims_view_from_matched_txn<B: Deref, F: Deref, L: Logger>(
809 &mut self, txn_matched: &[&Transaction], conf_height: u32, conf_hash: BlockHash,
810 cur_height: u32, broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L
812 B::Target: BroadcasterInterface,
813 F::Target: FeeEstimator,
815 log_debug!(logger, "Updating claims view at height {} with {} matched transactions in block {}", cur_height, txn_matched.len(), conf_height);
816 let mut bump_candidates = HashMap::new();
817 for tx in txn_matched {
818 // Scan all input to verify is one of the outpoint spent is of interest for us
819 let mut claimed_outputs_material = Vec::new();
820 for inp in &tx.input {
821 if let Some((claim_id, _)) = self.claimable_outpoints.get(&inp.previous_output) {
822 // If outpoint has claim request pending on it...
823 if let Some(request) = self.pending_claim_requests.get_mut(claim_id) {
824 //... we need to verify equality between transaction outpoints and claim request
825 // outpoints to know if transaction is the original claim or a bumped one issued
827 let mut are_sets_equal = true;
828 let mut tx_inputs = tx.input.iter().map(|input| &input.previous_output).collect::<Vec<_>>();
829 tx_inputs.sort_unstable();
830 for request_input in request.outpoints() {
831 if tx_inputs.binary_search(&request_input).is_err() {
832 are_sets_equal = false;
837 macro_rules! clean_claim_request_after_safety_delay {
839 let entry = OnchainEventEntry {
842 block_hash: Some(conf_hash),
843 event: OnchainEvent::Claim { claim_id: *claim_id }
845 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
846 self.onchain_events_awaiting_threshold_conf.push(entry);
851 // If this is our transaction (or our counterparty spent all the outputs
852 // before we could anyway with same inputs order than us), wait for
853 // ANTI_REORG_DELAY and clean the RBF tracking map.
855 clean_claim_request_after_safety_delay!();
856 } else { // If false, generate new claim request with update outpoint set
857 let mut at_least_one_drop = false;
858 for input in tx.input.iter() {
859 if let Some(package) = request.split_package(&input.previous_output) {
860 claimed_outputs_material.push(package);
861 at_least_one_drop = true;
863 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
864 if request.outpoints().is_empty() {
865 clean_claim_request_after_safety_delay!();
868 //TODO: recompute soonest_timelock to avoid wasting a bit on fees
869 if at_least_one_drop {
870 bump_candidates.insert(*claim_id, request.clone());
871 // If we have any pending claim events for the request being updated
872 // that have yet to be consumed, we'll remove them since they will
873 // end up producing an invalid transaction by double spending
874 // input(s) that already have a confirmed spend. If such spend is
875 // reorged out of the chain, then we'll attempt to re-spend the
876 // inputs once we see it.
877 #[cfg(debug_assertions)] {
878 let existing = self.pending_claim_events.iter()
879 .filter(|entry| entry.0 == *claim_id).count();
880 assert!(existing == 0 || existing == 1);
882 self.pending_claim_events.retain(|entry| entry.0 != *claim_id);
885 break; //No need to iterate further, either tx is our or their
887 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
891 for package in claimed_outputs_material.drain(..) {
892 let entry = OnchainEventEntry {
895 block_hash: Some(conf_hash),
896 event: OnchainEvent::ContentiousOutpoint { package },
898 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
899 self.onchain_events_awaiting_threshold_conf.push(entry);
904 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
905 let onchain_events_awaiting_threshold_conf =
906 self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
907 for entry in onchain_events_awaiting_threshold_conf {
908 if entry.has_reached_confirmation_threshold(cur_height) {
910 OnchainEvent::Claim { claim_id } => {
911 // We may remove a whole set of claim outpoints here, as these one may have
912 // been aggregated in a single tx and claimed so atomically
913 if let Some(request) = self.pending_claim_requests.remove(&claim_id) {
914 for outpoint in request.outpoints() {
915 log_debug!(logger, "Removing claim tracking for {} due to maturation of claim package {}.",
916 outpoint, log_bytes!(claim_id.0));
917 self.claimable_outpoints.remove(outpoint);
919 #[cfg(debug_assertions)] {
920 let num_existing = self.pending_claim_events.iter()
921 .filter(|entry| entry.0 == claim_id).count();
922 assert!(num_existing == 0 || num_existing == 1);
924 self.pending_claim_events.retain(|(id, _)| *id != claim_id);
927 OnchainEvent::ContentiousOutpoint { package } => {
928 log_debug!(logger, "Removing claim tracking due to maturation of claim tx for outpoints:");
929 log_debug!(logger, " {:?}", package.outpoints());
930 self.claimable_outpoints.remove(package.outpoints()[0]);
934 self.onchain_events_awaiting_threshold_conf.push(entry);
938 // Check if any pending claim request must be rescheduled
939 for (claim_id, request) in self.pending_claim_requests.iter() {
940 if cur_height >= request.timer() {
941 bump_candidates.insert(*claim_id, request.clone());
945 // Build, bump and rebroadcast tx accordingly
946 log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
947 for (claim_id, request) in bump_candidates.iter() {
948 if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(
949 cur_height, &request, true /* force_feerate_bump */, &*fee_estimator, &*logger,
952 OnchainClaim::Tx(bump_tx) => {
953 log_info!(logger, "Broadcasting RBF-bumped onchain {}", log_tx!(bump_tx));
954 broadcaster.broadcast_transactions(&[&bump_tx]);
956 OnchainClaim::Event(claim_event) => {
957 log_info!(logger, "Yielding RBF-bumped onchain event to spend inputs {:?}", request.outpoints());
958 #[cfg(debug_assertions)] {
959 let num_existing = self.pending_claim_events.iter().
960 filter(|entry| entry.0 == *claim_id).count();
961 assert!(num_existing == 0 || num_existing == 1);
963 self.pending_claim_events.retain(|event| event.0 != *claim_id);
964 self.pending_claim_events.push((*claim_id, claim_event));
967 if let Some(request) = self.pending_claim_requests.get_mut(claim_id) {
968 request.set_timer(new_timer);
969 request.set_feerate(new_feerate);
975 pub(super) fn transaction_unconfirmed<B: Deref, F: Deref, L: Logger>(
979 fee_estimator: &LowerBoundedFeeEstimator<F>,
982 B::Target: BroadcasterInterface,
983 F::Target: FeeEstimator,
985 let mut height = None;
986 for entry in self.onchain_events_awaiting_threshold_conf.iter() {
987 if entry.txid == *txid {
988 height = Some(entry.height);
993 if let Some(height) = height {
994 self.block_disconnected(height, broadcaster, fee_estimator, logger);
998 pub(super) fn block_disconnected<B: Deref, F: Deref, L: Logger>(&mut self, height: u32, broadcaster: B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L)
999 where B::Target: BroadcasterInterface,
1000 F::Target: FeeEstimator,
1002 let mut bump_candidates = HashMap::new();
1003 let onchain_events_awaiting_threshold_conf =
1004 self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
1005 for entry in onchain_events_awaiting_threshold_conf {
1006 if entry.height >= height {
1007 //- our claim tx on a commitment tx output
1008 //- resurect outpoint back in its claimable set and regenerate tx
1010 OnchainEvent::ContentiousOutpoint { package } => {
1011 if let Some(pending_claim) = self.claimable_outpoints.get(package.outpoints()[0]) {
1012 if let Some(request) = self.pending_claim_requests.get_mut(&pending_claim.0) {
1013 request.merge_package(package);
1014 // Using a HashMap guarantee us than if we have multiple outpoints getting
1015 // resurrected only one bump claim tx is going to be broadcast
1016 bump_candidates.insert(pending_claim.clone(), request.clone());
1023 self.onchain_events_awaiting_threshold_conf.push(entry);
1026 for ((_claim_id, _), ref mut request) in bump_candidates.iter_mut() {
1027 // `height` is the height being disconnected, so our `current_height` is 1 lower.
1028 let current_height = height - 1;
1029 if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(
1030 current_height, &request, true /* force_feerate_bump */, fee_estimator, logger
1032 request.set_timer(new_timer);
1033 request.set_feerate(new_feerate);
1035 OnchainClaim::Tx(bump_tx) => {
1036 log_info!(logger, "Broadcasting onchain {}", log_tx!(bump_tx));
1037 broadcaster.broadcast_transactions(&[&bump_tx]);
1039 OnchainClaim::Event(claim_event) => {
1040 log_info!(logger, "Yielding onchain event after reorg to spend inputs {:?}", request.outpoints());
1041 #[cfg(debug_assertions)] {
1042 let num_existing = self.pending_claim_events.iter()
1043 .filter(|entry| entry.0 == *_claim_id).count();
1044 assert!(num_existing == 0 || num_existing == 1);
1046 self.pending_claim_events.retain(|event| event.0 != *_claim_id);
1047 self.pending_claim_events.push((*_claim_id, claim_event));
1052 for (ancestor_claim_txid, request) in bump_candidates.drain() {
1053 self.pending_claim_requests.insert(ancestor_claim_txid.0, request);
1055 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
1056 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
1057 let mut remove_request = Vec::new();
1058 self.claimable_outpoints.retain(|_, ref v|
1060 remove_request.push(v.0.clone());
1063 for req in remove_request {
1064 self.pending_claim_requests.remove(&req);
1068 pub(crate) fn is_output_spend_pending(&self, outpoint: &BitcoinOutPoint) -> bool {
1069 self.claimable_outpoints.get(outpoint).is_some()
1072 pub(crate) fn get_relevant_txids(&self) -> Vec<(Txid, u32, Option<BlockHash>)> {
1073 let mut txids: Vec<(Txid, u32, Option<BlockHash>)> = self.onchain_events_awaiting_threshold_conf
1075 .map(|entry| (entry.txid, entry.height, entry.block_hash))
1077 txids.sort_unstable_by(|a, b| a.0.cmp(&b.0).then(b.1.cmp(&a.1)));
1078 txids.dedup_by_key(|(txid, _, _)| *txid);
1082 pub(crate) fn provide_latest_holder_tx(&mut self, tx: HolderCommitmentTransaction) {
1083 self.prev_holder_commitment = Some(replace(&mut self.holder_commitment, tx));
1086 pub(crate) fn get_unsigned_holder_commitment_tx(&self) -> &Transaction {
1087 &self.holder_commitment.trust().built_transaction().transaction
1090 //TODO: getting lastest holder transactions should be infallible and result in us "force-closing the channel", but we may
1091 // have empty holder commitment transaction if a ChannelMonitor is asked to force-close just after OutboundV1Channel::get_funding_created,
1092 // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
1093 // to monitor before.
1094 pub(crate) fn get_fully_signed_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
1095 let sig = self.signer.sign_holder_commitment(&self.holder_commitment, &self.secp_ctx).expect("signing holder commitment");
1096 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
1099 #[cfg(any(test, feature="unsafe_revoked_tx_signing"))]
1100 pub(crate) fn get_fully_signed_copy_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
1101 let sig = self.signer.unsafe_sign_holder_commitment(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
1102 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
1105 pub(crate) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
1106 let get_signed_htlc_tx = |holder_commitment: &HolderCommitmentTransaction| {
1107 let trusted_tx = holder_commitment.trust();
1108 if trusted_tx.txid() != outp.txid {
1111 let (htlc_idx, htlc) = trusted_tx.htlcs().iter().enumerate()
1112 .find(|(_, htlc)| htlc.transaction_output_index.unwrap() == outp.vout)
1114 let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[htlc_idx];
1115 let mut htlc_tx = trusted_tx.build_unsigned_htlc_tx(
1116 &self.channel_transaction_parameters.as_holder_broadcastable(), htlc_idx, preimage,
1119 let htlc_descriptor = HTLCDescriptor {
1120 channel_derivation_parameters: ChannelDerivationParameters {
1121 value_satoshis: self.channel_value_satoshis,
1122 keys_id: self.channel_keys_id,
1123 transaction_parameters: self.channel_transaction_parameters.clone(),
1125 commitment_txid: trusted_tx.txid(),
1126 per_commitment_number: trusted_tx.commitment_number(),
1127 per_commitment_point: trusted_tx.per_commitment_point(),
1128 feerate_per_kw: trusted_tx.feerate_per_kw(),
1130 preimage: preimage.clone(),
1131 counterparty_sig: counterparty_htlc_sig.clone(),
1133 let htlc_sig = self.signer.sign_holder_htlc_transaction(&htlc_tx, 0, &htlc_descriptor, &self.secp_ctx).unwrap();
1134 htlc_tx.input[0].witness = trusted_tx.build_htlc_input_witness(
1135 htlc_idx, &counterparty_htlc_sig, &htlc_sig, preimage,
1140 // Check if the HTLC spends from the current holder commitment first, or the previous.
1141 get_signed_htlc_tx(&self.holder_commitment)
1142 .or_else(|| self.prev_holder_commitment.as_ref().and_then(|prev_holder_commitment| get_signed_htlc_tx(prev_holder_commitment)))
1145 pub(crate) fn generate_external_htlc_claim(
1146 &self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>
1147 ) -> Option<ExternalHTLCClaim> {
1148 let find_htlc = |holder_commitment: &HolderCommitmentTransaction| -> Option<ExternalHTLCClaim> {
1149 let trusted_tx = holder_commitment.trust();
1150 if outp.txid != trusted_tx.txid() {
1153 trusted_tx.htlcs().iter().enumerate()
1154 .find(|(_, htlc)| if let Some(output_index) = htlc.transaction_output_index {
1155 output_index == outp.vout
1159 .map(|(htlc_idx, htlc)| {
1160 let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[htlc_idx];
1162 commitment_txid: trusted_tx.txid(),
1163 per_commitment_number: trusted_tx.commitment_number(),
1165 preimage: *preimage,
1166 counterparty_sig: counterparty_htlc_sig,
1170 // Check if the HTLC spends from the current holder commitment or the previous one otherwise.
1171 find_htlc(&self.holder_commitment)
1172 .or_else(|| self.prev_holder_commitment.as_ref().map(|c| find_htlc(c)).flatten())
1175 pub(crate) fn channel_type_features(&self) -> &ChannelTypeFeatures {
1176 &self.channel_transaction_parameters.channel_type_features