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 /// Represents the different feerates a pending request can use when generating a claim.
214 pub(crate) enum FeerateStrategy {
215 /// We must pick the highest between the most recently used and the current feerate estimate.
216 HighestOfPreviousOrNew,
217 /// We must force a bump of the most recently used feerate, either by using the current feerate
218 /// estimate if it's higher, or manually bumping.
222 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
223 /// do RBF bumping if possible.
225 pub struct OnchainTxHandler<ChannelSigner: WriteableEcdsaChannelSigner> {
226 channel_value_satoshis: u64,
227 channel_keys_id: [u8; 32],
228 destination_script: ScriptBuf,
229 holder_commitment: HolderCommitmentTransaction,
230 prev_holder_commitment: Option<HolderCommitmentTransaction>,
232 pub(super) signer: ChannelSigner,
233 pub(crate) channel_transaction_parameters: ChannelTransactionParameters,
235 // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
236 // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
237 // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
238 // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
239 // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
240 // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
241 // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
242 // we need to regenerate new claim request with reduced set of still-claimable outpoints.
243 // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
244 // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
245 // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
246 #[cfg(test)] // Used in functional_test to verify sanitization
247 pub(crate) pending_claim_requests: HashMap<ClaimId, PackageTemplate>,
249 pending_claim_requests: HashMap<ClaimId, PackageTemplate>,
251 // Used to track external events that need to be forwarded to the `ChainMonitor`. This `Vec`
252 // essentially acts as an insertion-ordered `HashMap` – there should only ever be one occurrence
253 // of a `ClaimId`, which tracks its latest `ClaimEvent`, i.e., if a pending claim exists, and
254 // a new block has been connected, resulting in a new claim, the previous will be replaced with
257 // These external events may be generated in the following cases:
258 // - A channel has been force closed by broadcasting the holder's latest commitment transaction
259 // - A block being connected/disconnected
260 // - Learning the preimage for an HTLC we can claim onchain
261 pending_claim_events: Vec<(ClaimId, ClaimEvent)>,
263 // Used to link outpoints claimed in a connected block to a pending claim request. The keys
264 // represent the outpoints that our `ChannelMonitor` has detected we have keys/scripts to
265 // claim. The values track the pending claim request identifier and the initial confirmation
266 // block height, and are immutable until the outpoint has enough confirmations to meet our
267 // [`ANTI_REORG_DELAY`]. The initial confirmation block height is used to remove the entry if
268 // the block gets disconnected.
269 #[cfg(test)] // Used in functional_test to verify sanitization
270 pub claimable_outpoints: HashMap<BitcoinOutPoint, (ClaimId, u32)>,
272 claimable_outpoints: HashMap<BitcoinOutPoint, (ClaimId, u32)>,
274 locktimed_packages: BTreeMap<u32, Vec<PackageTemplate>>,
276 onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
278 pub(super) secp_ctx: Secp256k1<secp256k1::All>,
281 impl<ChannelSigner: WriteableEcdsaChannelSigner> PartialEq for OnchainTxHandler<ChannelSigner> {
282 fn eq(&self, other: &Self) -> bool {
283 // `signer`, `secp_ctx`, and `pending_claim_events` are excluded on purpose.
284 self.channel_value_satoshis == other.channel_value_satoshis &&
285 self.channel_keys_id == other.channel_keys_id &&
286 self.destination_script == other.destination_script &&
287 self.holder_commitment == other.holder_commitment &&
288 self.prev_holder_commitment == other.prev_holder_commitment &&
289 self.channel_transaction_parameters == other.channel_transaction_parameters &&
290 self.pending_claim_requests == other.pending_claim_requests &&
291 self.claimable_outpoints == other.claimable_outpoints &&
292 self.locktimed_packages == other.locktimed_packages &&
293 self.onchain_events_awaiting_threshold_conf == other.onchain_events_awaiting_threshold_conf
297 const SERIALIZATION_VERSION: u8 = 1;
298 const MIN_SERIALIZATION_VERSION: u8 = 1;
300 impl<ChannelSigner: WriteableEcdsaChannelSigner> OnchainTxHandler<ChannelSigner> {
301 pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
302 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
304 self.destination_script.write(writer)?;
305 self.holder_commitment.write(writer)?;
306 None::<Option<Vec<Option<(usize, Signature)>>>>.write(writer)?; // holder_htlc_sigs
307 self.prev_holder_commitment.write(writer)?;
308 None::<Option<Vec<Option<(usize, Signature)>>>>.write(writer)?; // prev_holder_htlc_sigs
310 self.channel_transaction_parameters.write(writer)?;
312 let mut key_data = VecWriter(Vec::new());
313 self.signer.write(&mut key_data)?;
314 assert!(key_data.0.len() < core::usize::MAX);
315 assert!(key_data.0.len() < core::u32::MAX as usize);
316 (key_data.0.len() as u32).write(writer)?;
317 writer.write_all(&key_data.0[..])?;
319 writer.write_all(&(self.pending_claim_requests.len() as u64).to_be_bytes())?;
320 for (ref ancestor_claim_txid, request) in self.pending_claim_requests.iter() {
321 ancestor_claim_txid.write(writer)?;
322 request.write(writer)?;
325 writer.write_all(&(self.claimable_outpoints.len() as u64).to_be_bytes())?;
326 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
328 claim_and_height.0.write(writer)?;
329 claim_and_height.1.write(writer)?;
332 writer.write_all(&(self.locktimed_packages.len() as u64).to_be_bytes())?;
333 for (ref locktime, ref packages) in self.locktimed_packages.iter() {
334 locktime.write(writer)?;
335 writer.write_all(&(packages.len() as u64).to_be_bytes())?;
336 for ref package in packages.iter() {
337 package.write(writer)?;
341 writer.write_all(&(self.onchain_events_awaiting_threshold_conf.len() as u64).to_be_bytes())?;
342 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
343 entry.write(writer)?;
346 write_tlv_fields!(writer, {});
351 impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP, u64, [u8; 32])> for OnchainTxHandler<SP::EcdsaSigner> {
352 fn read<R: io::Read>(reader: &mut R, args: (&'a ES, &'b SP, u64, [u8; 32])) -> Result<Self, DecodeError> {
353 let entropy_source = args.0;
354 let signer_provider = args.1;
355 let channel_value_satoshis = args.2;
356 let channel_keys_id = args.3;
358 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
360 let destination_script = Readable::read(reader)?;
362 let holder_commitment = Readable::read(reader)?;
363 let _holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>> = Readable::read(reader)?;
364 let prev_holder_commitment = Readable::read(reader)?;
365 let _prev_holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>> = Readable::read(reader)?;
367 let channel_parameters = Readable::read(reader)?;
369 // Read the serialized signer bytes, but don't deserialize them, as we'll obtain our signer
370 // by re-deriving the private key material.
371 let keys_len: u32 = Readable::read(reader)?;
372 let mut bytes_read = 0;
373 while bytes_read != keys_len as usize {
374 // Read 1KB at a time to avoid accidentally allocating 4GB on corrupted channel keys
375 let mut data = [0; 1024];
376 let bytes_to_read = cmp::min(1024, keys_len as usize - bytes_read);
377 let read_slice = &mut data[0..bytes_to_read];
378 reader.read_exact(read_slice)?;
379 bytes_read += bytes_to_read;
382 let mut signer = signer_provider.derive_channel_signer(channel_value_satoshis, channel_keys_id);
383 signer.provide_channel_parameters(&channel_parameters);
385 let pending_claim_requests_len: u64 = Readable::read(reader)?;
386 let mut pending_claim_requests = hash_map_with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
387 for _ in 0..pending_claim_requests_len {
388 pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
391 let claimable_outpoints_len: u64 = Readable::read(reader)?;
392 let mut claimable_outpoints = hash_map_with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
393 for _ in 0..claimable_outpoints_len {
394 let outpoint = Readable::read(reader)?;
395 let ancestor_claim_txid = Readable::read(reader)?;
396 let height = Readable::read(reader)?;
397 claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
400 let locktimed_packages_len: u64 = Readable::read(reader)?;
401 let mut locktimed_packages = BTreeMap::new();
402 for _ in 0..locktimed_packages_len {
403 let locktime = Readable::read(reader)?;
404 let packages_len: u64 = Readable::read(reader)?;
405 let mut packages = Vec::with_capacity(cmp::min(packages_len as usize, MAX_ALLOC_SIZE / core::mem::size_of::<PackageTemplate>()));
406 for _ in 0..packages_len {
407 packages.push(Readable::read(reader)?);
409 locktimed_packages.insert(locktime, packages);
412 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
413 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
414 for _ in 0..waiting_threshold_conf_len {
415 if let Some(val) = MaybeReadable::read(reader)? {
416 onchain_events_awaiting_threshold_conf.push(val);
420 read_tlv_fields!(reader, {});
422 let mut secp_ctx = Secp256k1::new();
423 secp_ctx.seeded_randomize(&entropy_source.get_secure_random_bytes());
425 Ok(OnchainTxHandler {
426 channel_value_satoshis,
430 prev_holder_commitment,
432 channel_transaction_parameters: channel_parameters,
435 pending_claim_requests,
436 onchain_events_awaiting_threshold_conf,
437 pending_claim_events: Vec::new(),
443 impl<ChannelSigner: WriteableEcdsaChannelSigner> OnchainTxHandler<ChannelSigner> {
445 channel_value_satoshis: u64, channel_keys_id: [u8; 32], destination_script: ScriptBuf,
446 signer: ChannelSigner, channel_parameters: ChannelTransactionParameters,
447 holder_commitment: HolderCommitmentTransaction, secp_ctx: Secp256k1<secp256k1::All>
450 channel_value_satoshis,
454 prev_holder_commitment: None,
456 channel_transaction_parameters: channel_parameters,
457 pending_claim_requests: new_hash_map(),
458 claimable_outpoints: new_hash_map(),
459 locktimed_packages: BTreeMap::new(),
460 onchain_events_awaiting_threshold_conf: Vec::new(),
461 pending_claim_events: Vec::new(),
466 pub(crate) fn get_prev_holder_commitment_to_self_value(&self) -> Option<u64> {
467 self.prev_holder_commitment.as_ref().map(|commitment| commitment.to_broadcaster_value_sat())
470 pub(crate) fn get_cur_holder_commitment_to_self_value(&self) -> u64 {
471 self.holder_commitment.to_broadcaster_value_sat()
474 pub(crate) fn get_and_clear_pending_claim_events(&mut self) -> Vec<(ClaimId, ClaimEvent)> {
475 let mut events = Vec::new();
476 swap(&mut events, &mut self.pending_claim_events);
480 /// Triggers rebroadcasts/fee-bumps of pending claims from a force-closed channel. This is
481 /// crucial in preventing certain classes of pinning attacks, detecting substantial mempool
482 /// feerate changes between blocks, and ensuring reliability if broadcasting fails. We recommend
483 /// invoking this every 30 seconds, or lower if running in an environment with spotty
484 /// connections, like on mobile.
485 pub(super) fn rebroadcast_pending_claims<B: Deref, F: Deref, L: Logger>(
486 &mut self, current_height: u32, feerate_strategy: FeerateStrategy, broadcaster: &B,
487 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L,
490 B::Target: BroadcasterInterface,
491 F::Target: FeeEstimator,
493 let mut bump_requests = Vec::with_capacity(self.pending_claim_requests.len());
494 for (claim_id, request) in self.pending_claim_requests.iter() {
495 let inputs = request.outpoints();
496 log_info!(logger, "Triggering rebroadcast/fee-bump for request with inputs {:?}", inputs);
497 bump_requests.push((*claim_id, request.clone()));
499 for (claim_id, request) in bump_requests {
500 self.generate_claim(current_height, &request, &feerate_strategy, fee_estimator, logger)
501 .map(|(_, new_feerate, claim)| {
502 let mut bumped_feerate = false;
503 if let Some(mut_request) = self.pending_claim_requests.get_mut(&claim_id) {
504 bumped_feerate = request.previous_feerate() > new_feerate;
505 mut_request.set_feerate(new_feerate);
508 OnchainClaim::Tx(tx) => {
509 let log_start = if bumped_feerate { "Broadcasting RBF-bumped" } else { "Rebroadcasting" };
510 log_info!(logger, "{} onchain {}", log_start, log_tx!(tx));
511 broadcaster.broadcast_transactions(&[&tx]);
513 OnchainClaim::Event(event) => {
514 let log_start = if bumped_feerate { "Yielding fee-bumped" } else { "Replaying" };
515 log_info!(logger, "{} onchain event to spend inputs {:?}", log_start,
516 request.outpoints());
517 #[cfg(debug_assertions)] {
518 debug_assert!(request.requires_external_funding());
519 let num_existing = self.pending_claim_events.iter()
520 .filter(|entry| entry.0 == claim_id).count();
521 assert!(num_existing == 0 || num_existing == 1);
523 self.pending_claim_events.retain(|event| event.0 != claim_id);
524 self.pending_claim_events.push((claim_id, event));
531 /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize counterparty
532 /// onchain) lays on the assumption of claim transactions getting confirmed before timelock
533 /// expiration (CSV or CLTV following cases). In case of high-fee spikes, claim tx may get stuck
534 /// in the mempool, so you need to bump its feerate quickly using Replace-By-Fee or
535 /// Child-Pay-For-Parent.
537 /// Panics if there are signing errors, because signing operations in reaction to on-chain
538 /// events are not expected to fail, and if they do, we may lose funds.
539 fn generate_claim<F: Deref, L: Logger>(
540 &mut self, cur_height: u32, cached_request: &PackageTemplate, feerate_strategy: &FeerateStrategy,
541 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L,
542 ) -> Option<(u32, u64, OnchainClaim)>
543 where F::Target: FeeEstimator,
545 let request_outpoints = cached_request.outpoints();
546 if request_outpoints.is_empty() {
547 // Don't prune pending claiming request yet, we may have to resurrect HTLCs. Untractable
548 // packages cannot be aggregated and will never be split, so we cannot end up with an
550 debug_assert!(cached_request.is_malleable());
553 // If we've seen transaction inclusion in the chain for all outpoints in our request, we
554 // don't need to continue generating more claims. We'll keep tracking the request to fully
555 // remove it once it reaches the confirmation threshold, or to generate a new claim if the
556 // transaction is reorged out.
557 let mut all_inputs_have_confirmed_spend = true;
558 for outpoint in request_outpoints.iter() {
559 if let Some((request_claim_id, _)) = self.claimable_outpoints.get(*outpoint) {
560 // We check for outpoint spends within claims individually rather than as a set
561 // since requests can have outpoints split off.
562 if !self.onchain_events_awaiting_threshold_conf.iter()
563 .any(|event_entry| if let OnchainEvent::Claim { claim_id } = event_entry.event {
564 *request_claim_id == claim_id
566 // The onchain event is not a claim, keep seeking until we find one.
570 // Either we had no `OnchainEvent::Claim`, or we did but none matched the
571 // outpoint's registered spend.
572 all_inputs_have_confirmed_spend = false;
575 // The request's outpoint spend does not exist yet.
576 all_inputs_have_confirmed_spend = false;
579 if all_inputs_have_confirmed_spend {
583 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
584 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
585 let new_timer = cached_request.get_height_timer(cur_height);
586 if cached_request.is_malleable() {
587 if cached_request.requires_external_funding() {
588 let target_feerate_sat_per_1000_weight = cached_request.compute_package_feerate(
589 fee_estimator, ConfirmationTarget::OnChainSweep, feerate_strategy,
591 if let Some(htlcs) = cached_request.construct_malleable_package_with_external_funding(self) {
594 target_feerate_sat_per_1000_weight as u64,
595 OnchainClaim::Event(ClaimEvent::BumpHTLC {
596 target_feerate_sat_per_1000_weight,
598 tx_lock_time: LockTime::from_consensus(cached_request.package_locktime(cur_height)),
606 let predicted_weight = cached_request.package_weight(&self.destination_script);
607 if let Some((output_value, new_feerate)) = cached_request.compute_package_output(
608 predicted_weight, self.destination_script.dust_value().to_sat(),
609 feerate_strategy, fee_estimator, logger,
611 assert!(new_feerate != 0);
613 let transaction = cached_request.finalize_malleable_package(
614 cur_height, self, output_value, self.destination_script.clone(), logger
616 log_trace!(logger, "...with timer {} and feerate {}", new_timer, new_feerate);
617 assert!(predicted_weight >= transaction.weight().to_wu());
618 return Some((new_timer, new_feerate, OnchainClaim::Tx(transaction)));
621 // Untractable packages cannot have their fees bumped through Replace-By-Fee. Some
622 // packages may support fee bumping through Child-Pays-For-Parent, indicated by those
623 // which require external funding.
624 let mut inputs = cached_request.inputs();
625 debug_assert_eq!(inputs.len(), 1);
626 let tx = match cached_request.finalize_untractable_package(self, logger) {
630 if !cached_request.requires_external_funding() {
631 return Some((new_timer, 0, OnchainClaim::Tx(tx)));
633 return inputs.find_map(|input| match input {
634 // Commitment inputs with anchors support are the only untractable inputs supported
635 // thus far that require external funding.
636 PackageSolvingData::HolderFundingOutput(output) => {
637 debug_assert_eq!(tx.txid(), self.holder_commitment.trust().txid(),
638 "Holder commitment transaction mismatch");
640 let conf_target = ConfirmationTarget::OnChainSweep;
641 let package_target_feerate_sat_per_1000_weight = cached_request
642 .compute_package_feerate(fee_estimator, conf_target, feerate_strategy);
643 if let Some(input_amount_sat) = output.funding_amount {
644 let fee_sat = input_amount_sat - tx.output.iter().map(|output| output.value).sum::<u64>();
645 let commitment_tx_feerate_sat_per_1000_weight =
646 compute_feerate_sat_per_1000_weight(fee_sat, tx.weight().to_wu());
647 if commitment_tx_feerate_sat_per_1000_weight >= package_target_feerate_sat_per_1000_weight {
648 log_debug!(logger, "Pre-signed {} already has feerate {} sat/kW above required {} sat/kW",
649 log_tx!(tx), commitment_tx_feerate_sat_per_1000_weight,
650 package_target_feerate_sat_per_1000_weight);
651 return Some((new_timer, 0, OnchainClaim::Tx(tx.clone())));
655 // We'll locate an anchor output we can spend within the commitment transaction.
656 let funding_pubkey = &self.channel_transaction_parameters.holder_pubkeys.funding_pubkey;
657 match chan_utils::get_anchor_output(&tx, funding_pubkey) {
658 // An anchor output was found, so we should yield a funding event externally.
660 // TODO: Use a lower confirmation target when both our and the
661 // counterparty's latest commitment don't have any HTLCs present.
664 package_target_feerate_sat_per_1000_weight as u64,
665 OnchainClaim::Event(ClaimEvent::BumpCommitment {
666 package_target_feerate_sat_per_1000_weight,
667 commitment_tx: tx.clone(),
668 anchor_output_idx: idx,
672 // An anchor output was not found. There's nothing we can do other than
673 // attempt to broadcast the transaction with its current fee rate and hope
674 // it confirms. This is essentially the same behavior as a commitment
675 // transaction without anchor outputs.
676 None => Some((new_timer, 0, OnchainClaim::Tx(tx.clone()))),
680 debug_assert!(false, "Only HolderFundingOutput inputs should be untractable and require external funding");
688 pub fn abandon_claim(&mut self, outpoint: &BitcoinOutPoint) {
689 let claim_id = self.claimable_outpoints.get(outpoint).map(|(claim_id, _)| *claim_id)
691 self.pending_claim_requests.iter()
692 .find(|(_, claim)| claim.outpoints().iter().any(|claim_outpoint| *claim_outpoint == outpoint))
693 .map(|(claim_id, _)| *claim_id)
695 if let Some(claim_id) = claim_id {
696 if let Some(claim) = self.pending_claim_requests.remove(&claim_id) {
697 for outpoint in claim.outpoints() {
698 self.claimable_outpoints.remove(outpoint);
702 self.locktimed_packages.values_mut().for_each(|claims|
703 claims.retain(|claim| !claim.outpoints().iter().any(|claim_outpoint| *claim_outpoint == outpoint)));
707 /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
708 /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
709 /// Together with `update_claims_view_from_matched_txn` this used to be named
710 /// `block_connected`, but it is now also used for claiming an HTLC output if we receive a
711 /// preimage after force-close.
713 /// `conf_height` represents the height at which the request was generated. This
714 /// does not need to equal the current blockchain tip height, which should be provided via
715 /// `cur_height`, however it must never be higher than `cur_height`.
716 pub(super) fn update_claims_view_from_requests<B: Deref, F: Deref, L: Logger>(
717 &mut self, requests: Vec<PackageTemplate>, conf_height: u32, cur_height: u32,
718 broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L
720 B::Target: BroadcasterInterface,
721 F::Target: FeeEstimator,
723 log_debug!(logger, "Updating claims view at height {} with {} claim requests", cur_height, requests.len());
724 let mut preprocessed_requests = Vec::with_capacity(requests.len());
725 let mut aggregated_request = None;
727 // Try to aggregate outputs if their timelock expiration isn't imminent (package timelock
728 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
729 for req in requests {
730 // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
731 if let Some(_) = self.claimable_outpoints.get(req.outpoints()[0]) {
732 log_info!(logger, "Ignoring second claim for outpoint {}:{}, already registered its claiming request", req.outpoints()[0].txid, req.outpoints()[0].vout);
734 let timelocked_equivalent_package = self.locktimed_packages.iter().map(|v| v.1.iter()).flatten()
735 .find(|locked_package| locked_package.outpoints() == req.outpoints());
736 if let Some(package) = timelocked_equivalent_package {
737 log_info!(logger, "Ignoring second claim for outpoint {}:{}, we already have one which we're waiting on a timelock at {} for.",
738 req.outpoints()[0].txid, req.outpoints()[0].vout, package.package_locktime(cur_height));
742 let package_locktime = req.package_locktime(cur_height);
743 if package_locktime > cur_height + 1 {
744 log_info!(logger, "Delaying claim of package until its timelock at {} (current height {}), the following outpoints are spent:", package_locktime, cur_height);
745 for outpoint in req.outpoints() {
746 log_info!(logger, " Outpoint {}", outpoint);
748 self.locktimed_packages.entry(package_locktime).or_insert(Vec::new()).push(req);
752 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.timelock(), cur_height + CLTV_SHARED_CLAIM_BUFFER);
753 if req.timelock() <= cur_height + CLTV_SHARED_CLAIM_BUFFER || !req.aggregable() {
754 // Don't aggregate if outpoint package timelock is soon or marked as non-aggregable
755 preprocessed_requests.push(req);
756 } else if aggregated_request.is_none() {
757 aggregated_request = Some(req);
759 aggregated_request.as_mut().unwrap().merge_package(req);
763 if let Some(req) = aggregated_request {
764 preprocessed_requests.push(req);
767 // Claim everything up to and including `cur_height`
768 let remaining_locked_packages = self.locktimed_packages.split_off(&(cur_height + 1));
769 for (pop_height, mut entry) in self.locktimed_packages.iter_mut() {
770 log_trace!(logger, "Restoring delayed claim of package(s) at their timelock at {}.", pop_height);
771 preprocessed_requests.append(&mut entry);
773 self.locktimed_packages = remaining_locked_packages;
775 // Generate claim transactions and track them to bump if necessary at
776 // height timer expiration (i.e in how many blocks we're going to take action).
777 for mut req in preprocessed_requests {
778 if let Some((new_timer, new_feerate, claim)) = self.generate_claim(
779 cur_height, &req, &FeerateStrategy::ForceBump, &*fee_estimator, &*logger,
781 req.set_timer(new_timer);
782 req.set_feerate(new_feerate);
783 // Once a pending claim has an id assigned, it remains fixed until the claim is
784 // satisfied, regardless of whether the claim switches between different variants of
786 let claim_id = match claim {
787 OnchainClaim::Tx(tx) => {
788 log_info!(logger, "Broadcasting onchain {}", log_tx!(tx));
789 broadcaster.broadcast_transactions(&[&tx]);
790 ClaimId(tx.txid().to_byte_array())
792 OnchainClaim::Event(claim_event) => {
793 log_info!(logger, "Yielding onchain event to spend inputs {:?}", req.outpoints());
794 let claim_id = match claim_event {
795 ClaimEvent::BumpCommitment { ref commitment_tx, .. } =>
796 // For commitment claims, we can just use their txid as it should
797 // already be unique.
798 ClaimId(commitment_tx.txid().to_byte_array()),
799 ClaimEvent::BumpHTLC { ref htlcs, .. } => {
800 // For HTLC claims, commit to the entire set of HTLC outputs to
801 // claim, which will always be unique per request. Once a claim ID
802 // is generated, it is assigned and remains unchanged, even if the
803 // underlying set of HTLCs changes.
804 let mut engine = Sha256::engine();
806 engine.input(&htlc.commitment_txid.to_byte_array());
807 engine.input(&htlc.htlc.transaction_output_index.unwrap().to_be_bytes());
809 ClaimId(Sha256::from_engine(engine).to_byte_array())
812 debug_assert!(self.pending_claim_requests.get(&claim_id).is_none());
813 debug_assert_eq!(self.pending_claim_events.iter().filter(|entry| entry.0 == claim_id).count(), 0);
814 self.pending_claim_events.push((claim_id, claim_event));
818 // Because fuzzing can cause hash collisions, we can end up with conflicting claim
819 // ids here, so we only assert when not fuzzing.
820 debug_assert!(cfg!(fuzzing) || self.pending_claim_requests.get(&claim_id).is_none());
821 for k in req.outpoints() {
822 log_info!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
823 self.claimable_outpoints.insert(k.clone(), (claim_id, conf_height));
825 self.pending_claim_requests.insert(claim_id, req);
830 /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
831 /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
832 /// Together with `update_claims_view_from_requests` this used to be named `block_connected`,
833 /// but it is now also used for claiming an HTLC output if we receive a preimage after force-close.
835 /// `conf_height` represents the height at which the transactions in `txn_matched` were
836 /// confirmed. This does not need to equal the current blockchain tip height, which should be
837 /// provided via `cur_height`, however it must never be higher than `cur_height`.
838 pub(super) fn update_claims_view_from_matched_txn<B: Deref, F: Deref, L: Logger>(
839 &mut self, txn_matched: &[&Transaction], conf_height: u32, conf_hash: BlockHash,
840 cur_height: u32, broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L
842 B::Target: BroadcasterInterface,
843 F::Target: FeeEstimator,
845 log_debug!(logger, "Updating claims view at height {} with {} matched transactions in block {}", cur_height, txn_matched.len(), conf_height);
846 let mut bump_candidates = new_hash_map();
847 for tx in txn_matched {
848 // Scan all input to verify is one of the outpoint spent is of interest for us
849 let mut claimed_outputs_material = Vec::new();
850 for inp in &tx.input {
851 if let Some((claim_id, _)) = self.claimable_outpoints.get(&inp.previous_output) {
852 // If outpoint has claim request pending on it...
853 if let Some(request) = self.pending_claim_requests.get_mut(claim_id) {
854 //... we need to verify equality between transaction outpoints and claim request
855 // outpoints to know if transaction is the original claim or a bumped one issued
857 let mut are_sets_equal = true;
858 let mut tx_inputs = tx.input.iter().map(|input| &input.previous_output).collect::<Vec<_>>();
859 tx_inputs.sort_unstable();
860 for request_input in request.outpoints() {
861 if tx_inputs.binary_search(&request_input).is_err() {
862 are_sets_equal = false;
867 macro_rules! clean_claim_request_after_safety_delay {
869 let entry = OnchainEventEntry {
872 block_hash: Some(conf_hash),
873 event: OnchainEvent::Claim { claim_id: *claim_id }
875 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
876 self.onchain_events_awaiting_threshold_conf.push(entry);
881 // If this is our transaction (or our counterparty spent all the outputs
882 // before we could anyway with same inputs order than us), wait for
883 // ANTI_REORG_DELAY and clean the RBF tracking map.
885 clean_claim_request_after_safety_delay!();
886 } else { // If false, generate new claim request with update outpoint set
887 let mut at_least_one_drop = false;
888 for input in tx.input.iter() {
889 if let Some(package) = request.split_package(&input.previous_output) {
890 claimed_outputs_material.push(package);
891 at_least_one_drop = true;
893 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
894 if request.outpoints().is_empty() {
895 clean_claim_request_after_safety_delay!();
898 //TODO: recompute soonest_timelock to avoid wasting a bit on fees
899 if at_least_one_drop {
900 bump_candidates.insert(*claim_id, request.clone());
901 // If we have any pending claim events for the request being updated
902 // that have yet to be consumed, we'll remove them since they will
903 // end up producing an invalid transaction by double spending
904 // input(s) that already have a confirmed spend. If such spend is
905 // reorged out of the chain, then we'll attempt to re-spend the
906 // inputs once we see it.
907 #[cfg(debug_assertions)] {
908 let existing = self.pending_claim_events.iter()
909 .filter(|entry| entry.0 == *claim_id).count();
910 assert!(existing == 0 || existing == 1);
912 self.pending_claim_events.retain(|entry| entry.0 != *claim_id);
915 break; //No need to iterate further, either tx is our or their
917 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
921 for package in claimed_outputs_material.drain(..) {
922 let entry = OnchainEventEntry {
925 block_hash: Some(conf_hash),
926 event: OnchainEvent::ContentiousOutpoint { package },
928 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
929 self.onchain_events_awaiting_threshold_conf.push(entry);
934 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
935 let onchain_events_awaiting_threshold_conf =
936 self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
937 for entry in onchain_events_awaiting_threshold_conf {
938 if entry.has_reached_confirmation_threshold(cur_height) {
940 OnchainEvent::Claim { claim_id } => {
941 // We may remove a whole set of claim outpoints here, as these one may have
942 // been aggregated in a single tx and claimed so atomically
943 if let Some(request) = self.pending_claim_requests.remove(&claim_id) {
944 for outpoint in request.outpoints() {
945 log_debug!(logger, "Removing claim tracking for {} due to maturation of claim package {}.",
946 outpoint, log_bytes!(claim_id.0));
947 self.claimable_outpoints.remove(outpoint);
949 #[cfg(debug_assertions)] {
950 let num_existing = self.pending_claim_events.iter()
951 .filter(|entry| entry.0 == claim_id).count();
952 assert!(num_existing == 0 || num_existing == 1);
954 self.pending_claim_events.retain(|(id, _)| *id != claim_id);
957 OnchainEvent::ContentiousOutpoint { package } => {
958 log_debug!(logger, "Removing claim tracking due to maturation of claim tx for outpoints:");
959 log_debug!(logger, " {:?}", package.outpoints());
960 self.claimable_outpoints.remove(package.outpoints()[0]);
964 self.onchain_events_awaiting_threshold_conf.push(entry);
968 // Check if any pending claim request must be rescheduled
969 for (claim_id, request) in self.pending_claim_requests.iter() {
970 if cur_height >= request.timer() {
971 bump_candidates.insert(*claim_id, request.clone());
975 // Build, bump and rebroadcast tx accordingly
976 log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
977 for (claim_id, request) in bump_candidates.iter() {
978 if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(
979 cur_height, &request, &FeerateStrategy::ForceBump, &*fee_estimator, &*logger,
982 OnchainClaim::Tx(bump_tx) => {
983 log_info!(logger, "Broadcasting RBF-bumped onchain {}", log_tx!(bump_tx));
984 broadcaster.broadcast_transactions(&[&bump_tx]);
986 OnchainClaim::Event(claim_event) => {
987 log_info!(logger, "Yielding RBF-bumped onchain event to spend inputs {:?}", request.outpoints());
988 #[cfg(debug_assertions)] {
989 let num_existing = self.pending_claim_events.iter().
990 filter(|entry| entry.0 == *claim_id).count();
991 assert!(num_existing == 0 || num_existing == 1);
993 self.pending_claim_events.retain(|event| event.0 != *claim_id);
994 self.pending_claim_events.push((*claim_id, claim_event));
997 if let Some(request) = self.pending_claim_requests.get_mut(claim_id) {
998 request.set_timer(new_timer);
999 request.set_feerate(new_feerate);
1005 pub(super) fn transaction_unconfirmed<B: Deref, F: Deref, L: Logger>(
1009 fee_estimator: &LowerBoundedFeeEstimator<F>,
1012 B::Target: BroadcasterInterface,
1013 F::Target: FeeEstimator,
1015 let mut height = None;
1016 for entry in self.onchain_events_awaiting_threshold_conf.iter() {
1017 if entry.txid == *txid {
1018 height = Some(entry.height);
1023 if let Some(height) = height {
1024 self.block_disconnected(height, broadcaster, fee_estimator, logger);
1028 pub(super) fn block_disconnected<B: Deref, F: Deref, L: Logger>(&mut self, height: u32, broadcaster: B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L)
1029 where B::Target: BroadcasterInterface,
1030 F::Target: FeeEstimator,
1032 let mut bump_candidates = new_hash_map();
1033 let onchain_events_awaiting_threshold_conf =
1034 self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
1035 for entry in onchain_events_awaiting_threshold_conf {
1036 if entry.height >= height {
1037 //- our claim tx on a commitment tx output
1038 //- resurect outpoint back in its claimable set and regenerate tx
1040 OnchainEvent::ContentiousOutpoint { package } => {
1041 if let Some(pending_claim) = self.claimable_outpoints.get(package.outpoints()[0]) {
1042 if let Some(request) = self.pending_claim_requests.get_mut(&pending_claim.0) {
1043 request.merge_package(package);
1044 // Using a HashMap guarantee us than if we have multiple outpoints getting
1045 // resurrected only one bump claim tx is going to be broadcast
1046 bump_candidates.insert(pending_claim.clone(), request.clone());
1053 self.onchain_events_awaiting_threshold_conf.push(entry);
1056 for ((_claim_id, _), ref mut request) in bump_candidates.iter_mut() {
1057 // `height` is the height being disconnected, so our `current_height` is 1 lower.
1058 let current_height = height - 1;
1059 if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(
1060 current_height, &request, &FeerateStrategy::ForceBump, fee_estimator, logger
1062 request.set_timer(new_timer);
1063 request.set_feerate(new_feerate);
1065 OnchainClaim::Tx(bump_tx) => {
1066 log_info!(logger, "Broadcasting onchain {}", log_tx!(bump_tx));
1067 broadcaster.broadcast_transactions(&[&bump_tx]);
1069 OnchainClaim::Event(claim_event) => {
1070 log_info!(logger, "Yielding onchain event after reorg to spend inputs {:?}", request.outpoints());
1071 #[cfg(debug_assertions)] {
1072 let num_existing = self.pending_claim_events.iter()
1073 .filter(|entry| entry.0 == *_claim_id).count();
1074 assert!(num_existing == 0 || num_existing == 1);
1076 self.pending_claim_events.retain(|event| event.0 != *_claim_id);
1077 self.pending_claim_events.push((*_claim_id, claim_event));
1082 for (ancestor_claim_txid, request) in bump_candidates.drain() {
1083 self.pending_claim_requests.insert(ancestor_claim_txid.0, request);
1085 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
1086 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
1087 let mut remove_request = Vec::new();
1088 self.claimable_outpoints.retain(|_, ref v|
1090 remove_request.push(v.0.clone());
1093 for req in remove_request {
1094 self.pending_claim_requests.remove(&req);
1098 pub(crate) fn is_output_spend_pending(&self, outpoint: &BitcoinOutPoint) -> bool {
1099 self.claimable_outpoints.get(outpoint).is_some()
1102 pub(crate) fn get_relevant_txids(&self) -> Vec<(Txid, u32, Option<BlockHash>)> {
1103 let mut txids: Vec<(Txid, u32, Option<BlockHash>)> = self.onchain_events_awaiting_threshold_conf
1105 .map(|entry| (entry.txid, entry.height, entry.block_hash))
1107 txids.sort_unstable_by(|a, b| a.0.cmp(&b.0).then(b.1.cmp(&a.1)));
1108 txids.dedup_by_key(|(txid, _, _)| *txid);
1112 pub(crate) fn provide_latest_holder_tx(&mut self, tx: HolderCommitmentTransaction) {
1113 self.prev_holder_commitment = Some(replace(&mut self.holder_commitment, tx));
1116 pub(crate) fn get_unsigned_holder_commitment_tx(&self) -> &Transaction {
1117 &self.holder_commitment.trust().built_transaction().transaction
1120 //TODO: getting lastest holder transactions should be infallible and result in us "force-closing the channel", but we may
1121 // have empty holder commitment transaction if a ChannelMonitor is asked to force-close just after OutboundV1Channel::get_funding_created,
1122 // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
1123 // to monitor before.
1124 pub(crate) fn get_fully_signed_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
1125 let sig = self.signer.sign_holder_commitment(&self.holder_commitment, &self.secp_ctx).expect("signing holder commitment");
1126 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
1129 #[cfg(any(test, feature="unsafe_revoked_tx_signing"))]
1130 pub(crate) fn get_fully_signed_copy_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
1131 let sig = self.signer.unsafe_sign_holder_commitment(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
1132 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
1135 pub(crate) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
1136 let get_signed_htlc_tx = |holder_commitment: &HolderCommitmentTransaction| {
1137 let trusted_tx = holder_commitment.trust();
1138 if trusted_tx.txid() != outp.txid {
1141 let (htlc_idx, htlc) = trusted_tx.htlcs().iter().enumerate()
1142 .find(|(_, htlc)| htlc.transaction_output_index.unwrap() == outp.vout)
1144 let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[htlc_idx];
1145 let mut htlc_tx = trusted_tx.build_unsigned_htlc_tx(
1146 &self.channel_transaction_parameters.as_holder_broadcastable(), htlc_idx, preimage,
1149 let htlc_descriptor = HTLCDescriptor {
1150 channel_derivation_parameters: ChannelDerivationParameters {
1151 value_satoshis: self.channel_value_satoshis,
1152 keys_id: self.channel_keys_id,
1153 transaction_parameters: self.channel_transaction_parameters.clone(),
1155 commitment_txid: trusted_tx.txid(),
1156 per_commitment_number: trusted_tx.commitment_number(),
1157 per_commitment_point: trusted_tx.per_commitment_point(),
1158 feerate_per_kw: trusted_tx.feerate_per_kw(),
1160 preimage: preimage.clone(),
1161 counterparty_sig: counterparty_htlc_sig.clone(),
1163 let htlc_sig = self.signer.sign_holder_htlc_transaction(&htlc_tx, 0, &htlc_descriptor, &self.secp_ctx).unwrap();
1164 htlc_tx.input[0].witness = trusted_tx.build_htlc_input_witness(
1165 htlc_idx, &counterparty_htlc_sig, &htlc_sig, preimage,
1170 // Check if the HTLC spends from the current holder commitment first, or the previous.
1171 get_signed_htlc_tx(&self.holder_commitment)
1172 .or_else(|| self.prev_holder_commitment.as_ref().and_then(|prev_holder_commitment| get_signed_htlc_tx(prev_holder_commitment)))
1175 pub(crate) fn generate_external_htlc_claim(
1176 &self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>
1177 ) -> Option<ExternalHTLCClaim> {
1178 let find_htlc = |holder_commitment: &HolderCommitmentTransaction| -> Option<ExternalHTLCClaim> {
1179 let trusted_tx = holder_commitment.trust();
1180 if outp.txid != trusted_tx.txid() {
1183 trusted_tx.htlcs().iter().enumerate()
1184 .find(|(_, htlc)| if let Some(output_index) = htlc.transaction_output_index {
1185 output_index == outp.vout
1189 .map(|(htlc_idx, htlc)| {
1190 let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[htlc_idx];
1192 commitment_txid: trusted_tx.txid(),
1193 per_commitment_number: trusted_tx.commitment_number(),
1195 preimage: *preimage,
1196 counterparty_sig: counterparty_htlc_sig,
1200 // Check if the HTLC spends from the current holder commitment or the previous one otherwise.
1201 find_htlc(&self.holder_commitment)
1202 .or_else(|| self.prev_holder_commitment.as_ref().map(|c| find_htlc(c)).flatten())
1205 pub(crate) fn channel_type_features(&self) -> &ChannelTypeFeatures {
1206 &self.channel_transaction_parameters.channel_type_features