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::PackedLockTime;
16 use bitcoin::blockdata::transaction::Transaction;
17 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
18 use bitcoin::blockdata::script::Script;
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::sign::{ChannelSigner, EntropySource, SignerProvider};
26 use crate::ln::msgs::DecodeError;
27 use crate::ln::PaymentPreimage;
28 use crate::ln::chan_utils::{self, ChannelTransactionParameters, HTLCOutputInCommitment, HolderCommitmentTransaction};
29 use crate::chain::ClaimId;
30 use crate::chain::chaininterface::{ConfirmationTarget, FeeEstimator, BroadcasterInterface, LowerBoundedFeeEstimator};
31 use crate::chain::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER};
32 use crate::sign::WriteableEcdsaChannelSigner;
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(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(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 pub(crate) struct ExternalHTLCClaim {
175 pub(crate) commitment_txid: Txid,
176 pub(crate) per_commitment_number: u64,
177 pub(crate) htlc: HTLCOutputInCommitment,
178 pub(crate) preimage: Option<PaymentPreimage>,
179 pub(crate) counterparty_sig: Signature,
182 // Represents the different types of claims for which events are yielded externally to satisfy said
184 pub(crate) enum ClaimEvent {
185 /// Event yielded to signal that the commitment transaction fee must be bumped to claim any
186 /// encumbered funds and proceed to HTLC resolution, if any HTLCs exist.
188 package_target_feerate_sat_per_1000_weight: u32,
189 commitment_tx: Transaction,
190 anchor_output_idx: u32,
192 /// Event yielded to signal that the commitment transaction has confirmed and its HTLCs must be
193 /// resolved by broadcasting a transaction with sufficient fee to claim them.
195 target_feerate_sat_per_1000_weight: u32,
196 htlcs: Vec<ExternalHTLCClaim>,
197 tx_lock_time: PackedLockTime,
201 /// Represents the different ways an output can be claimed (i.e., spent to an address under our
202 /// control) onchain.
203 pub(crate) enum OnchainClaim {
204 /// A finalized transaction pending confirmation spending the output to claim.
206 /// An event yielded externally to signal additional inputs must be added to a transaction
207 /// pending confirmation spending the output to claim.
211 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
212 /// do RBF bumping if possible.
213 pub struct OnchainTxHandler<ChannelSigner: WriteableEcdsaChannelSigner> {
214 destination_script: Script,
215 holder_commitment: HolderCommitmentTransaction,
216 // holder_htlc_sigs and prev_holder_htlc_sigs are in the order as they appear in the commitment
217 // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
218 // the set of HTLCs in the HolderCommitmentTransaction.
219 holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
220 prev_holder_commitment: Option<HolderCommitmentTransaction>,
221 prev_holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
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.destination_script == other.destination_script &&
276 self.holder_commitment == other.holder_commitment &&
277 self.holder_htlc_sigs == other.holder_htlc_sigs &&
278 self.prev_holder_commitment == other.prev_holder_commitment &&
279 self.prev_holder_htlc_sigs == other.prev_holder_htlc_sigs &&
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 self.holder_htlc_sigs.write(writer)?;
298 self.prev_holder_commitment.write(writer)?;
299 self.prev_holder_htlc_sigs.write(writer)?;
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::Signer> {
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 = Readable::read(reader)?;
355 let prev_holder_commitment = Readable::read(reader)?;
356 let prev_holder_htlc_sigs = 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 {
420 prev_holder_commitment,
421 prev_holder_htlc_sigs,
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> {
435 pub(crate) fn new(destination_script: Script, signer: ChannelSigner, channel_parameters: ChannelTransactionParameters, holder_commitment: HolderCommitmentTransaction, secp_ctx: Secp256k1<secp256k1::All>) -> Self {
439 holder_htlc_sigs: None,
440 prev_holder_commitment: None,
441 prev_holder_htlc_sigs: None,
443 channel_transaction_parameters: channel_parameters,
444 pending_claim_requests: HashMap::new(),
445 claimable_outpoints: HashMap::new(),
446 locktimed_packages: BTreeMap::new(),
447 onchain_events_awaiting_threshold_conf: Vec::new(),
448 pending_claim_events: Vec::new(),
453 pub(crate) fn get_prev_holder_commitment_to_self_value(&self) -> Option<u64> {
454 self.prev_holder_commitment.as_ref().map(|commitment| commitment.to_broadcaster_value_sat())
457 pub(crate) fn get_cur_holder_commitment_to_self_value(&self) -> u64 {
458 self.holder_commitment.to_broadcaster_value_sat()
461 pub(crate) fn get_and_clear_pending_claim_events(&mut self) -> Vec<(ClaimId, ClaimEvent)> {
462 let mut events = Vec::new();
463 swap(&mut events, &mut self.pending_claim_events);
467 /// Triggers rebroadcasts/fee-bumps of pending claims from a force-closed channel. This is
468 /// crucial in preventing certain classes of pinning attacks, detecting substantial mempool
469 /// feerate changes between blocks, and ensuring reliability if broadcasting fails. We recommend
470 /// invoking this every 30 seconds, or lower if running in an environment with spotty
471 /// connections, like on mobile.
472 pub(crate) fn rebroadcast_pending_claims<B: Deref, F: Deref, L: Deref>(
473 &mut self, current_height: u32, broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>,
477 B::Target: BroadcasterInterface,
478 F::Target: FeeEstimator,
481 let mut bump_requests = Vec::with_capacity(self.pending_claim_requests.len());
482 for (claim_id, request) in self.pending_claim_requests.iter() {
483 let inputs = request.outpoints();
484 log_info!(logger, "Triggering rebroadcast/fee-bump for request with inputs {:?}", inputs);
485 bump_requests.push((*claim_id, request.clone()));
487 for (claim_id, request) in bump_requests {
488 self.generate_claim(current_height, &request, false /* force_feerate_bump */, fee_estimator, logger)
489 .map(|(_, new_feerate, claim)| {
490 let mut bumped_feerate = false;
491 if let Some(mut_request) = self.pending_claim_requests.get_mut(&claim_id) {
492 bumped_feerate = request.previous_feerate() > new_feerate;
493 mut_request.set_feerate(new_feerate);
496 OnchainClaim::Tx(tx) => {
497 let log_start = if bumped_feerate { "Broadcasting RBF-bumped" } else { "Rebroadcasting" };
498 log_info!(logger, "{} onchain {}", log_start, log_tx!(tx));
499 broadcaster.broadcast_transactions(&[&tx]);
501 OnchainClaim::Event(event) => {
502 let log_start = if bumped_feerate { "Yielding fee-bumped" } else { "Replaying" };
503 log_info!(logger, "{} onchain event to spend inputs {:?}", log_start,
504 request.outpoints());
505 #[cfg(debug_assertions)] {
506 debug_assert!(request.requires_external_funding());
507 let num_existing = self.pending_claim_events.iter()
508 .filter(|entry| entry.0 == claim_id).count();
509 assert!(num_existing == 0 || num_existing == 1);
511 self.pending_claim_events.retain(|event| event.0 != claim_id);
512 self.pending_claim_events.push((claim_id, event));
519 /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize counterparty
520 /// onchain) lays on the assumption of claim transactions getting confirmed before timelock
521 /// expiration (CSV or CLTV following cases). In case of high-fee spikes, claim tx may get stuck
522 /// in the mempool, so you need to bump its feerate quickly using Replace-By-Fee or
523 /// Child-Pay-For-Parent.
525 /// Panics if there are signing errors, because signing operations in reaction to on-chain
526 /// events are not expected to fail, and if they do, we may lose funds.
527 fn generate_claim<F: Deref, L: Deref>(
528 &mut self, cur_height: u32, cached_request: &PackageTemplate, force_feerate_bump: bool,
529 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L,
530 ) -> Option<(u32, u64, OnchainClaim)>
532 F::Target: FeeEstimator,
535 let request_outpoints = cached_request.outpoints();
536 if request_outpoints.is_empty() {
537 // Don't prune pending claiming request yet, we may have to resurrect HTLCs. Untractable
538 // packages cannot be aggregated and will never be split, so we cannot end up with an
540 debug_assert!(cached_request.is_malleable());
543 // If we've seen transaction inclusion in the chain for all outpoints in our request, we
544 // don't need to continue generating more claims. We'll keep tracking the request to fully
545 // remove it once it reaches the confirmation threshold, or to generate a new claim if the
546 // transaction is reorged out.
547 let mut all_inputs_have_confirmed_spend = true;
548 for outpoint in request_outpoints.iter() {
549 if let Some((request_claim_id, _)) = self.claimable_outpoints.get(*outpoint) {
550 // We check for outpoint spends within claims individually rather than as a set
551 // since requests can have outpoints split off.
552 if !self.onchain_events_awaiting_threshold_conf.iter()
553 .any(|event_entry| if let OnchainEvent::Claim { claim_id } = event_entry.event {
554 *request_claim_id == claim_id
556 // The onchain event is not a claim, keep seeking until we find one.
560 // Either we had no `OnchainEvent::Claim`, or we did but none matched the
561 // outpoint's registered spend.
562 all_inputs_have_confirmed_spend = false;
565 // The request's outpoint spend does not exist yet.
566 all_inputs_have_confirmed_spend = false;
569 if all_inputs_have_confirmed_spend {
573 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
574 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
575 let new_timer = cached_request.get_height_timer(cur_height);
576 if cached_request.is_malleable() {
577 if cached_request.requires_external_funding() {
578 let target_feerate_sat_per_1000_weight = cached_request.compute_package_feerate(
579 fee_estimator, ConfirmationTarget::HighPriority, force_feerate_bump
581 if let Some(htlcs) = cached_request.construct_malleable_package_with_external_funding(self) {
584 target_feerate_sat_per_1000_weight as u64,
585 OnchainClaim::Event(ClaimEvent::BumpHTLC {
586 target_feerate_sat_per_1000_weight,
588 tx_lock_time: PackedLockTime(cached_request.package_locktime(cur_height)),
596 let predicted_weight = cached_request.package_weight(&self.destination_script);
597 if let Some((output_value, new_feerate)) = cached_request.compute_package_output(
598 predicted_weight, self.destination_script.dust_value().to_sat(),
599 force_feerate_bump, fee_estimator, logger,
601 assert!(new_feerate != 0);
603 let transaction = cached_request.finalize_malleable_package(
604 cur_height, self, output_value, self.destination_script.clone(), logger
606 log_trace!(logger, "...with timer {} and feerate {}", new_timer, new_feerate);
607 assert!(predicted_weight >= transaction.weight());
608 return Some((new_timer, new_feerate, OnchainClaim::Tx(transaction)));
611 // Untractable packages cannot have their fees bumped through Replace-By-Fee. Some
612 // packages may support fee bumping through Child-Pays-For-Parent, indicated by those
613 // which require external funding.
614 let mut inputs = cached_request.inputs();
615 debug_assert_eq!(inputs.len(), 1);
616 let tx = match cached_request.finalize_untractable_package(self, logger) {
620 if !cached_request.requires_external_funding() {
621 return Some((new_timer, 0, OnchainClaim::Tx(tx)));
623 return inputs.find_map(|input| match input {
624 // Commitment inputs with anchors support are the only untractable inputs supported
625 // thus far that require external funding.
626 PackageSolvingData::HolderFundingOutput(..) => {
627 debug_assert_eq!(tx.txid(), self.holder_commitment.trust().txid(),
628 "Holder commitment transaction mismatch");
629 // We'll locate an anchor output we can spend within the commitment transaction.
630 let funding_pubkey = &self.channel_transaction_parameters.holder_pubkeys.funding_pubkey;
631 match chan_utils::get_anchor_output(&tx, funding_pubkey) {
632 // An anchor output was found, so we should yield a funding event externally.
634 // TODO: Use a lower confirmation target when both our and the
635 // counterparty's latest commitment don't have any HTLCs present.
636 let conf_target = ConfirmationTarget::HighPriority;
637 let package_target_feerate_sat_per_1000_weight = cached_request
638 .compute_package_feerate(fee_estimator, conf_target, force_feerate_bump);
641 package_target_feerate_sat_per_1000_weight as u64,
642 OnchainClaim::Event(ClaimEvent::BumpCommitment {
643 package_target_feerate_sat_per_1000_weight,
644 commitment_tx: tx.clone(),
645 anchor_output_idx: idx,
649 // An anchor output was not found. There's nothing we can do other than
650 // attempt to broadcast the transaction with its current fee rate and hope
651 // it confirms. This is essentially the same behavior as a commitment
652 // transaction without anchor outputs.
653 None => Some((new_timer, 0, OnchainClaim::Tx(tx.clone()))),
657 debug_assert!(false, "Only HolderFundingOutput inputs should be untractable and require external funding");
665 /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
666 /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
667 /// Together with `update_claims_view_from_matched_txn` this used to be named
668 /// `block_connected`, but it is now also used for claiming an HTLC output if we receive a
669 /// preimage after force-close.
671 /// `conf_height` represents the height at which the request was generated. This
672 /// does not need to equal the current blockchain tip height, which should be provided via
673 /// `cur_height`, however it must never be higher than `cur_height`.
674 pub(crate) fn update_claims_view_from_requests<B: Deref, F: Deref, L: Deref>(
675 &mut self, requests: Vec<PackageTemplate>, conf_height: u32, cur_height: u32,
676 broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L
678 B::Target: BroadcasterInterface,
679 F::Target: FeeEstimator,
682 log_debug!(logger, "Updating claims view at height {} with {} claim requests", cur_height, requests.len());
683 let mut preprocessed_requests = Vec::with_capacity(requests.len());
684 let mut aggregated_request = None;
686 // Try to aggregate outputs if their timelock expiration isn't imminent (package timelock
687 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
688 for req in requests {
689 // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
690 if let Some(_) = self.claimable_outpoints.get(req.outpoints()[0]) {
691 log_info!(logger, "Ignoring second claim for outpoint {}:{}, already registered its claiming request", req.outpoints()[0].txid, req.outpoints()[0].vout);
693 let timelocked_equivalent_package = self.locktimed_packages.iter().map(|v| v.1.iter()).flatten()
694 .find(|locked_package| locked_package.outpoints() == req.outpoints());
695 if let Some(package) = timelocked_equivalent_package {
696 log_info!(logger, "Ignoring second claim for outpoint {}:{}, we already have one which we're waiting on a timelock at {} for.",
697 req.outpoints()[0].txid, req.outpoints()[0].vout, package.package_locktime(cur_height));
701 let package_locktime = req.package_locktime(cur_height);
702 if package_locktime > cur_height + 1 {
703 log_info!(logger, "Delaying claim of package until its timelock at {} (current height {}), the following outpoints are spent:", package_locktime, cur_height);
704 for outpoint in req.outpoints() {
705 log_info!(logger, " Outpoint {}", outpoint);
707 self.locktimed_packages.entry(package_locktime).or_insert(Vec::new()).push(req);
711 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.timelock(), cur_height + CLTV_SHARED_CLAIM_BUFFER);
712 if req.timelock() <= cur_height + CLTV_SHARED_CLAIM_BUFFER || !req.aggregable() {
713 // Don't aggregate if outpoint package timelock is soon or marked as non-aggregable
714 preprocessed_requests.push(req);
715 } else if aggregated_request.is_none() {
716 aggregated_request = Some(req);
718 aggregated_request.as_mut().unwrap().merge_package(req);
722 if let Some(req) = aggregated_request {
723 preprocessed_requests.push(req);
726 // Claim everything up to and including `cur_height`
727 let remaining_locked_packages = self.locktimed_packages.split_off(&(cur_height + 1));
728 for (pop_height, mut entry) in self.locktimed_packages.iter_mut() {
729 log_trace!(logger, "Restoring delayed claim of package(s) at their timelock at {}.", pop_height);
730 preprocessed_requests.append(&mut entry);
732 self.locktimed_packages = remaining_locked_packages;
734 // Generate claim transactions and track them to bump if necessary at
735 // height timer expiration (i.e in how many blocks we're going to take action).
736 for mut req in preprocessed_requests {
737 if let Some((new_timer, new_feerate, claim)) = self.generate_claim(
738 cur_height, &req, true /* force_feerate_bump */, &*fee_estimator, &*logger,
740 req.set_timer(new_timer);
741 req.set_feerate(new_feerate);
742 let claim_id = match claim {
743 OnchainClaim::Tx(tx) => {
744 log_info!(logger, "Broadcasting onchain {}", log_tx!(tx));
745 broadcaster.broadcast_transactions(&[&tx]);
746 ClaimId(tx.txid().into_inner())
748 OnchainClaim::Event(claim_event) => {
749 log_info!(logger, "Yielding onchain event to spend inputs {:?}", req.outpoints());
750 let claim_id = match claim_event {
751 ClaimEvent::BumpCommitment { ref commitment_tx, .. } =>
752 // For commitment claims, we can just use their txid as it should
753 // already be unique.
754 ClaimId(commitment_tx.txid().into_inner()),
755 ClaimEvent::BumpHTLC { ref htlcs, .. } => {
756 // For HTLC claims, commit to the entire set of HTLC outputs to
757 // claim, which will always be unique per request. Once a claim ID
758 // is generated, it is assigned and remains unchanged, even if the
759 // underlying set of HTLCs changes.
760 let mut engine = Sha256::engine();
762 engine.input(&htlc.commitment_txid.into_inner());
763 engine.input(&htlc.htlc.transaction_output_index.unwrap().to_be_bytes());
765 ClaimId(Sha256::from_engine(engine).into_inner())
768 debug_assert!(self.pending_claim_requests.get(&claim_id).is_none());
769 debug_assert_eq!(self.pending_claim_events.iter().filter(|entry| entry.0 == claim_id).count(), 0);
770 self.pending_claim_events.push((claim_id, claim_event));
774 debug_assert!(self.pending_claim_requests.get(&claim_id).is_none());
775 for k in req.outpoints() {
776 log_info!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
777 self.claimable_outpoints.insert(k.clone(), (claim_id, conf_height));
779 self.pending_claim_requests.insert(claim_id, req);
784 /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
785 /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
786 /// Together with `update_claims_view_from_requests` this used to be named `block_connected`,
787 /// but it is now also used for claiming an HTLC output if we receive a preimage after force-close.
789 /// `conf_height` represents the height at which the transactions in `txn_matched` were
790 /// confirmed. This does not need to equal the current blockchain tip height, which should be
791 /// provided via `cur_height`, however it must never be higher than `cur_height`.
792 pub(crate) fn update_claims_view_from_matched_txn<B: Deref, F: Deref, L: Deref>(
793 &mut self, txn_matched: &[&Transaction], conf_height: u32, conf_hash: BlockHash,
794 cur_height: u32, broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L
796 B::Target: BroadcasterInterface,
797 F::Target: FeeEstimator,
800 log_debug!(logger, "Updating claims view at height {} with {} matched transactions in block {}", cur_height, txn_matched.len(), conf_height);
801 let mut bump_candidates = HashMap::new();
802 for tx in txn_matched {
803 // Scan all input to verify is one of the outpoint spent is of interest for us
804 let mut claimed_outputs_material = Vec::new();
805 for inp in &tx.input {
806 if let Some((claim_id, _)) = self.claimable_outpoints.get(&inp.previous_output) {
807 // If outpoint has claim request pending on it...
808 if let Some(request) = self.pending_claim_requests.get_mut(claim_id) {
809 //... we need to verify equality between transaction outpoints and claim request
810 // outpoints to know if transaction is the original claim or a bumped one issued
812 let mut are_sets_equal = true;
813 let mut tx_inputs = tx.input.iter().map(|input| &input.previous_output).collect::<Vec<_>>();
814 tx_inputs.sort_unstable();
815 for request_input in request.outpoints() {
816 if tx_inputs.binary_search(&request_input).is_err() {
817 are_sets_equal = false;
822 macro_rules! clean_claim_request_after_safety_delay {
824 let entry = OnchainEventEntry {
827 block_hash: Some(conf_hash),
828 event: OnchainEvent::Claim { claim_id: *claim_id }
830 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
831 self.onchain_events_awaiting_threshold_conf.push(entry);
836 // If this is our transaction (or our counterparty spent all the outputs
837 // before we could anyway with same inputs order than us), wait for
838 // ANTI_REORG_DELAY and clean the RBF tracking map.
840 clean_claim_request_after_safety_delay!();
841 } else { // If false, generate new claim request with update outpoint set
842 let mut at_least_one_drop = false;
843 for input in tx.input.iter() {
844 if let Some(package) = request.split_package(&input.previous_output) {
845 claimed_outputs_material.push(package);
846 at_least_one_drop = true;
848 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
849 if request.outpoints().is_empty() {
850 clean_claim_request_after_safety_delay!();
853 //TODO: recompute soonest_timelock to avoid wasting a bit on fees
854 if at_least_one_drop {
855 bump_candidates.insert(*claim_id, request.clone());
856 // If we have any pending claim events for the request being updated
857 // that have yet to be consumed, we'll remove them since they will
858 // end up producing an invalid transaction by double spending
859 // input(s) that already have a confirmed spend. If such spend is
860 // reorged out of the chain, then we'll attempt to re-spend the
861 // inputs once we see it.
862 #[cfg(debug_assertions)] {
863 let existing = self.pending_claim_events.iter()
864 .filter(|entry| entry.0 == *claim_id).count();
865 assert!(existing == 0 || existing == 1);
867 self.pending_claim_events.retain(|entry| entry.0 != *claim_id);
870 break; //No need to iterate further, either tx is our or their
872 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
876 for package in claimed_outputs_material.drain(..) {
877 let entry = OnchainEventEntry {
880 block_hash: Some(conf_hash),
881 event: OnchainEvent::ContentiousOutpoint { package },
883 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
884 self.onchain_events_awaiting_threshold_conf.push(entry);
889 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
890 let onchain_events_awaiting_threshold_conf =
891 self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
892 for entry in onchain_events_awaiting_threshold_conf {
893 if entry.has_reached_confirmation_threshold(cur_height) {
895 OnchainEvent::Claim { claim_id } => {
896 // We may remove a whole set of claim outpoints here, as these one may have
897 // been aggregated in a single tx and claimed so atomically
898 if let Some(request) = self.pending_claim_requests.remove(&claim_id) {
899 for outpoint in request.outpoints() {
900 log_debug!(logger, "Removing claim tracking for {} due to maturation of claim package {}.",
901 outpoint, log_bytes!(claim_id.0));
902 self.claimable_outpoints.remove(outpoint);
904 #[cfg(debug_assertions)] {
905 let num_existing = self.pending_claim_events.iter()
906 .filter(|entry| entry.0 == claim_id).count();
907 assert!(num_existing == 0 || num_existing == 1);
909 self.pending_claim_events.retain(|(id, _)| *id != claim_id);
912 OnchainEvent::ContentiousOutpoint { package } => {
913 log_debug!(logger, "Removing claim tracking due to maturation of claim tx for outpoints:");
914 log_debug!(logger, " {:?}", package.outpoints());
915 self.claimable_outpoints.remove(package.outpoints()[0]);
919 self.onchain_events_awaiting_threshold_conf.push(entry);
923 // Check if any pending claim request must be rescheduled
924 for (claim_id, request) in self.pending_claim_requests.iter() {
925 if cur_height >= request.timer() {
926 bump_candidates.insert(*claim_id, request.clone());
930 // Build, bump and rebroadcast tx accordingly
931 log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
932 for (claim_id, request) in bump_candidates.iter() {
933 if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(
934 cur_height, &request, true /* force_feerate_bump */, &*fee_estimator, &*logger,
937 OnchainClaim::Tx(bump_tx) => {
938 log_info!(logger, "Broadcasting RBF-bumped onchain {}", log_tx!(bump_tx));
939 broadcaster.broadcast_transactions(&[&bump_tx]);
941 OnchainClaim::Event(claim_event) => {
942 log_info!(logger, "Yielding RBF-bumped onchain event to spend inputs {:?}", request.outpoints());
943 #[cfg(debug_assertions)] {
944 let num_existing = self.pending_claim_events.iter().
945 filter(|entry| entry.0 == *claim_id).count();
946 assert!(num_existing == 0 || num_existing == 1);
948 self.pending_claim_events.retain(|event| event.0 != *claim_id);
949 self.pending_claim_events.push((*claim_id, claim_event));
952 if let Some(request) = self.pending_claim_requests.get_mut(claim_id) {
953 request.set_timer(new_timer);
954 request.set_feerate(new_feerate);
960 pub(crate) fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
964 fee_estimator: &LowerBoundedFeeEstimator<F>,
967 B::Target: BroadcasterInterface,
968 F::Target: FeeEstimator,
971 let mut height = None;
972 for entry in self.onchain_events_awaiting_threshold_conf.iter() {
973 if entry.txid == *txid {
974 height = Some(entry.height);
979 if let Some(height) = height {
980 self.block_disconnected(height, broadcaster, fee_estimator, logger);
984 pub(crate) fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: L)
985 where B::Target: BroadcasterInterface,
986 F::Target: FeeEstimator,
989 let mut bump_candidates = HashMap::new();
990 let onchain_events_awaiting_threshold_conf =
991 self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
992 for entry in onchain_events_awaiting_threshold_conf {
993 if entry.height >= height {
994 //- our claim tx on a commitment tx output
995 //- resurect outpoint back in its claimable set and regenerate tx
997 OnchainEvent::ContentiousOutpoint { package } => {
998 if let Some(pending_claim) = self.claimable_outpoints.get(package.outpoints()[0]) {
999 if let Some(request) = self.pending_claim_requests.get_mut(&pending_claim.0) {
1000 request.merge_package(package);
1001 // Using a HashMap guarantee us than if we have multiple outpoints getting
1002 // resurrected only one bump claim tx is going to be broadcast
1003 bump_candidates.insert(pending_claim.clone(), request.clone());
1010 self.onchain_events_awaiting_threshold_conf.push(entry);
1013 for ((_claim_id, _), ref mut request) in bump_candidates.iter_mut() {
1014 // `height` is the height being disconnected, so our `current_height` is 1 lower.
1015 let current_height = height - 1;
1016 if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(
1017 current_height, &request, true /* force_feerate_bump */, fee_estimator, &&*logger
1019 request.set_timer(new_timer);
1020 request.set_feerate(new_feerate);
1022 OnchainClaim::Tx(bump_tx) => {
1023 log_info!(logger, "Broadcasting onchain {}", log_tx!(bump_tx));
1024 broadcaster.broadcast_transactions(&[&bump_tx]);
1026 OnchainClaim::Event(claim_event) => {
1027 log_info!(logger, "Yielding onchain event after reorg to spend inputs {:?}", request.outpoints());
1028 #[cfg(debug_assertions)] {
1029 let num_existing = self.pending_claim_events.iter()
1030 .filter(|entry| entry.0 == *_claim_id).count();
1031 assert!(num_existing == 0 || num_existing == 1);
1033 self.pending_claim_events.retain(|event| event.0 != *_claim_id);
1034 self.pending_claim_events.push((*_claim_id, claim_event));
1039 for (ancestor_claim_txid, request) in bump_candidates.drain() {
1040 self.pending_claim_requests.insert(ancestor_claim_txid.0, request);
1042 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
1043 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
1044 let mut remove_request = Vec::new();
1045 self.claimable_outpoints.retain(|_, ref v|
1047 remove_request.push(v.0.clone());
1050 for req in remove_request {
1051 self.pending_claim_requests.remove(&req);
1055 pub(crate) fn is_output_spend_pending(&self, outpoint: &BitcoinOutPoint) -> bool {
1056 self.claimable_outpoints.get(outpoint).is_some()
1059 pub(crate) fn get_relevant_txids(&self) -> Vec<(Txid, Option<BlockHash>)> {
1060 let mut txids: Vec<(Txid, Option<BlockHash>)> = self.onchain_events_awaiting_threshold_conf
1062 .map(|entry| (entry.txid, entry.block_hash))
1064 txids.sort_unstable_by_key(|(txid, _)| *txid);
1069 pub(crate) fn provide_latest_holder_tx(&mut self, tx: HolderCommitmentTransaction) {
1070 self.prev_holder_commitment = Some(replace(&mut self.holder_commitment, tx));
1071 self.holder_htlc_sigs = None;
1074 // Normally holder HTLCs are signed at the same time as the holder commitment tx. However,
1075 // in some configurations, the holder commitment tx has been signed and broadcast by a
1076 // ChannelMonitor replica, so we handle that case here.
1077 fn sign_latest_holder_htlcs(&mut self) {
1078 if self.holder_htlc_sigs.is_none() {
1079 let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
1080 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, sigs));
1084 // Normally only the latest commitment tx and HTLCs need to be signed. However, in some
1085 // configurations we may have updated our holder commitment but a replica of the ChannelMonitor
1086 // broadcast the previous one before we sync with it. We handle that case here.
1087 fn sign_prev_holder_htlcs(&mut self) {
1088 if self.prev_holder_htlc_sigs.is_none() {
1089 if let Some(ref holder_commitment) = self.prev_holder_commitment {
1090 let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(holder_commitment, &self.secp_ctx).expect("sign previous holder commitment");
1091 self.prev_holder_htlc_sigs = Some(Self::extract_holder_sigs(holder_commitment, sigs));
1096 fn extract_holder_sigs(holder_commitment: &HolderCommitmentTransaction, sigs: Vec<Signature>) -> Vec<Option<(usize, Signature)>> {
1097 let mut ret = Vec::new();
1098 for (htlc_idx, (holder_sig, htlc)) in sigs.iter().zip(holder_commitment.htlcs().iter()).enumerate() {
1099 let tx_idx = htlc.transaction_output_index.unwrap();
1100 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
1101 ret[tx_idx as usize] = Some((htlc_idx, holder_sig.clone()));
1106 //TODO: getting lastest holder transactions should be infallible and result in us "force-closing the channel", but we may
1107 // have empty holder commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
1108 // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
1109 // to monitor before.
1110 pub(crate) fn get_fully_signed_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
1111 let (sig, htlc_sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("signing holder commitment");
1112 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
1113 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
1116 #[cfg(any(test, feature="unsafe_revoked_tx_signing"))]
1117 pub(crate) fn get_fully_signed_copy_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
1118 let (sig, htlc_sigs) = self.signer.unsafe_sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
1119 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
1120 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
1123 pub(crate) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
1124 let mut htlc_tx = None;
1125 let commitment_txid = self.holder_commitment.trust().txid();
1126 // Check if the HTLC spends from the current holder commitment
1127 if commitment_txid == outp.txid {
1128 self.sign_latest_holder_htlcs();
1129 if let &Some(ref htlc_sigs) = &self.holder_htlc_sigs {
1130 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
1131 let trusted_tx = self.holder_commitment.trust();
1132 let counterparty_htlc_sig = self.holder_commitment.counterparty_htlc_sigs[*htlc_idx];
1133 htlc_tx = Some(trusted_tx
1134 .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
1137 // If the HTLC doesn't spend the current holder commitment, check if it spends the previous one
1138 if htlc_tx.is_none() && self.prev_holder_commitment.is_some() {
1139 let commitment_txid = self.prev_holder_commitment.as_ref().unwrap().trust().txid();
1140 if commitment_txid == outp.txid {
1141 self.sign_prev_holder_htlcs();
1142 if let &Some(ref htlc_sigs) = &self.prev_holder_htlc_sigs {
1143 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
1144 let holder_commitment = self.prev_holder_commitment.as_ref().unwrap();
1145 let trusted_tx = holder_commitment.trust();
1146 let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[*htlc_idx];
1147 htlc_tx = Some(trusted_tx
1148 .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
1155 pub(crate) fn generate_external_htlc_claim(
1156 &self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>
1157 ) -> Option<ExternalHTLCClaim> {
1158 let find_htlc = |holder_commitment: &HolderCommitmentTransaction| -> Option<ExternalHTLCClaim> {
1159 let trusted_tx = holder_commitment.trust();
1160 if outp.txid != trusted_tx.txid() {
1163 trusted_tx.htlcs().iter().enumerate()
1164 .find(|(_, htlc)| if let Some(output_index) = htlc.transaction_output_index {
1165 output_index == outp.vout
1169 .map(|(htlc_idx, htlc)| {
1170 let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[htlc_idx];
1172 commitment_txid: trusted_tx.txid(),
1173 per_commitment_number: trusted_tx.commitment_number(),
1175 preimage: *preimage,
1176 counterparty_sig: counterparty_htlc_sig,
1180 // Check if the HTLC spends from the current holder commitment or the previous one otherwise.
1181 find_htlc(&self.holder_commitment)
1182 .or_else(|| self.prev_holder_commitment.as_ref().map(|c| find_htlc(c)).flatten())
1185 pub(crate) fn channel_type_features(&self) -> &ChannelTypeFeatures {
1186 &self.channel_transaction_parameters.channel_type_features
1189 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
1190 pub(crate) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
1191 let latest_had_sigs = self.holder_htlc_sigs.is_some();
1192 let prev_had_sigs = self.prev_holder_htlc_sigs.is_some();
1193 let ret = self.get_fully_signed_htlc_tx(outp, preimage);
1194 if !latest_had_sigs {
1195 self.holder_htlc_sigs = None;
1198 self.prev_holder_htlc_sigs = None;