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::amount::Amount;
16 use bitcoin::blockdata::locktime::absolute::LockTime;
17 use bitcoin::blockdata::transaction::Transaction;
18 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
19 use bitcoin::blockdata::script::{Script, ScriptBuf};
20 use bitcoin::hashes::{Hash, HashEngine};
21 use bitcoin::hashes::sha256::Hash as Sha256;
22 use bitcoin::hash_types::{Txid, BlockHash};
23 use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature};
24 use bitcoin::secp256k1;
26 use crate::chain::chaininterface::compute_feerate_sat_per_1000_weight;
27 use crate::sign::{ChannelDerivationParameters, HTLCDescriptor, ChannelSigner, EntropySource, SignerProvider, ecdsa::EcdsaChannelSigner};
28 use crate::ln::msgs::DecodeError;
29 use crate::ln::types::PaymentPreimage;
30 use crate::ln::chan_utils::{self, ChannelTransactionParameters, HTLCOutputInCommitment, HolderCommitmentTransaction};
31 use crate::chain::ClaimId;
32 use crate::chain::chaininterface::{ConfirmationTarget, FeeEstimator, BroadcasterInterface, LowerBoundedFeeEstimator};
33 use crate::chain::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER};
34 use crate::chain::package::{PackageSolvingData, PackageTemplate};
35 use crate::chain::transaction::MaybeSignedTransaction;
36 use crate::util::logger::Logger;
37 use crate::util::ser::{Readable, ReadableArgs, MaybeReadable, UpgradableRequired, Writer, Writeable};
40 use crate::prelude::*;
41 use alloc::collections::BTreeMap;
44 use core::mem::replace;
46 use crate::ln::features::ChannelTypeFeatures;
48 const MAX_ALLOC_SIZE: usize = 64*1024;
50 /// An entry for an [`OnchainEvent`], stating the block height when the event was observed and the
51 /// transaction causing it.
53 /// Used to determine when the on-chain event can be considered safe from a chain reorganization.
54 #[derive(Clone, PartialEq, Eq)]
55 struct OnchainEventEntry {
58 block_hash: Option<BlockHash>, // Added as optional, will be filled in for any entry generated on 0.0.113 or after
62 impl OnchainEventEntry {
63 fn confirmation_threshold(&self) -> u32 {
64 self.height + ANTI_REORG_DELAY - 1
67 fn has_reached_confirmation_threshold(&self, height: u32) -> bool {
68 height >= self.confirmation_threshold()
72 /// Events for claims the [`OnchainTxHandler`] has generated. Once the events are considered safe
73 /// from a chain reorg, the [`OnchainTxHandler`] will act accordingly.
74 #[derive(Clone, PartialEq, Eq)]
76 /// A pending request has been claimed by a transaction spending the exact same set of outpoints
77 /// as the request. This claim can either be ours or from the counterparty. Once the claiming
78 /// transaction has met [`ANTI_REORG_DELAY`] confirmations, we consider it final and remove the
83 /// The counterparty has claimed an outpoint from one of our pending requests through a
84 /// different transaction than ours. If our transaction was attempting to claim multiple
85 /// outputs, we need to drop the outpoint claimed by the counterparty and regenerate a new claim
86 /// transaction for ourselves. We keep tracking, separately, the outpoint claimed by the
87 /// counterparty up to [`ANTI_REORG_DELAY`] confirmations to ensure we attempt to re-claim it
88 /// if the counterparty's claim is reorged from the chain.
90 package: PackageTemplate,
94 impl Writeable for OnchainEventEntry {
95 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
96 write_tlv_fields!(writer, {
97 (0, self.txid, required),
98 (1, self.block_hash, option),
99 (2, self.height, required),
100 (4, self.event, required),
106 impl MaybeReadable for OnchainEventEntry {
107 fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, DecodeError> {
108 let mut txid = Txid::all_zeros();
110 let mut block_hash = None;
111 let mut event = UpgradableRequired(None);
112 read_tlv_fields!(reader, {
114 (1, block_hash, option),
115 (2, height, required),
116 (4, event, upgradable_required),
118 Ok(Some(Self { txid, height, block_hash, event: _init_tlv_based_struct_field!(event, upgradable_required) }))
122 impl_writeable_tlv_based_enum_upgradable!(OnchainEvent,
124 (0, claim_id, required),
126 (1, ContentiousOutpoint) => {
127 (0, package, required),
131 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
132 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
133 match Readable::read(reader)? {
136 let vlen: u64 = Readable::read(reader)?;
137 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::core::mem::size_of::<Option<(usize, Signature)>>()));
139 ret.push(match Readable::read(reader)? {
141 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
142 _ => return Err(DecodeError::InvalidValue)
147 _ => Err(DecodeError::InvalidValue),
152 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
153 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
157 (vec.len() as u64).write(writer)?;
158 for opt in vec.iter() {
160 &Some((ref idx, ref sig)) => {
162 (*idx as u64).write(writer)?;
165 &None => 0u8.write(writer)?,
169 &None => 0u8.write(writer)?,
175 /// The claim commonly referred to as the pre-signed second-stage HTLC transaction.
176 #[derive(Clone, PartialEq, Eq)]
177 pub(crate) struct ExternalHTLCClaim {
178 pub(crate) commitment_txid: Txid,
179 pub(crate) per_commitment_number: u64,
180 pub(crate) htlc: HTLCOutputInCommitment,
181 pub(crate) preimage: Option<PaymentPreimage>,
182 pub(crate) counterparty_sig: Signature,
185 // Represents the different types of claims for which events are yielded externally to satisfy said
187 #[derive(Clone, PartialEq, Eq)]
188 pub(crate) enum ClaimEvent {
189 /// Event yielded to signal that the commitment transaction fee must be bumped to claim any
190 /// encumbered funds and proceed to HTLC resolution, if any HTLCs exist.
192 package_target_feerate_sat_per_1000_weight: u32,
193 commitment_tx: Transaction,
194 anchor_output_idx: u32,
196 /// Event yielded to signal that the commitment transaction has confirmed and its HTLCs must be
197 /// resolved by broadcasting a transaction with sufficient fee to claim them.
199 target_feerate_sat_per_1000_weight: u32,
200 htlcs: Vec<ExternalHTLCClaim>,
201 tx_lock_time: LockTime,
205 /// Represents the different ways an output can be claimed (i.e., spent to an address under our
206 /// control) onchain.
207 pub(crate) enum OnchainClaim {
208 /// A finalized transaction pending confirmation spending the output to claim.
209 Tx(MaybeSignedTransaction),
210 /// An event yielded externally to signal additional inputs must be added to a transaction
211 /// pending confirmation spending the output to claim.
215 /// Represents the different feerate strategies a pending request can use when generating a claim.
216 pub(crate) enum FeerateStrategy {
217 /// We must reuse the most recently used feerate, if any.
219 /// We must pick the highest between the most recently used and the current feerate estimate.
220 HighestOfPreviousOrNew,
221 /// We must force a bump of the most recently used feerate, either by using the current feerate
222 /// estimate if it's higher, or manually bumping.
226 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
227 /// do RBF bumping if possible.
229 pub struct OnchainTxHandler<ChannelSigner: EcdsaChannelSigner> {
230 channel_value_satoshis: u64,
231 channel_keys_id: [u8; 32],
232 destination_script: ScriptBuf,
233 holder_commitment: HolderCommitmentTransaction,
234 prev_holder_commitment: Option<HolderCommitmentTransaction>,
236 pub(super) signer: ChannelSigner,
237 pub(crate) channel_transaction_parameters: ChannelTransactionParameters,
239 // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
240 // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
241 // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
242 // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
243 // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
244 // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
245 // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
246 // we need to regenerate new claim request with reduced set of still-claimable outpoints.
247 // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
248 // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
249 // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
250 #[cfg(test)] // Used in functional_test to verify sanitization
251 pub(crate) pending_claim_requests: HashMap<ClaimId, PackageTemplate>,
253 pending_claim_requests: HashMap<ClaimId, PackageTemplate>,
255 // Used to track external events that need to be forwarded to the `ChainMonitor`. This `Vec`
256 // essentially acts as an insertion-ordered `HashMap` – there should only ever be one occurrence
257 // of a `ClaimId`, which tracks its latest `ClaimEvent`, i.e., if a pending claim exists, and
258 // a new block has been connected, resulting in a new claim, the previous will be replaced with
261 // These external events may be generated in the following cases:
262 // - A channel has been force closed by broadcasting the holder's latest commitment transaction
263 // - A block being connected/disconnected
264 // - Learning the preimage for an HTLC we can claim onchain
265 pending_claim_events: Vec<(ClaimId, ClaimEvent)>,
267 // Used to link outpoints claimed in a connected block to a pending claim request. The keys
268 // represent the outpoints that our `ChannelMonitor` has detected we have keys/scripts to
269 // claim. The values track the pending claim request identifier and the initial confirmation
270 // block height, and are immutable until the outpoint has enough confirmations to meet our
271 // [`ANTI_REORG_DELAY`]. The initial confirmation block height is used to remove the entry if
272 // the block gets disconnected.
273 #[cfg(test)] // Used in functional_test to verify sanitization
274 pub claimable_outpoints: HashMap<BitcoinOutPoint, (ClaimId, u32)>,
276 claimable_outpoints: HashMap<BitcoinOutPoint, (ClaimId, u32)>,
278 locktimed_packages: BTreeMap<u32, Vec<PackageTemplate>>,
280 onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
282 pub(super) secp_ctx: Secp256k1<secp256k1::All>,
285 impl<ChannelSigner: EcdsaChannelSigner> PartialEq for OnchainTxHandler<ChannelSigner> {
286 fn eq(&self, other: &Self) -> bool {
287 // `signer`, `secp_ctx`, and `pending_claim_events` are excluded on purpose.
288 self.channel_value_satoshis == other.channel_value_satoshis &&
289 self.channel_keys_id == other.channel_keys_id &&
290 self.destination_script == other.destination_script &&
291 self.holder_commitment == other.holder_commitment &&
292 self.prev_holder_commitment == other.prev_holder_commitment &&
293 self.channel_transaction_parameters == other.channel_transaction_parameters &&
294 self.pending_claim_requests == other.pending_claim_requests &&
295 self.claimable_outpoints == other.claimable_outpoints &&
296 self.locktimed_packages == other.locktimed_packages &&
297 self.onchain_events_awaiting_threshold_conf == other.onchain_events_awaiting_threshold_conf
301 const SERIALIZATION_VERSION: u8 = 1;
302 const MIN_SERIALIZATION_VERSION: u8 = 1;
304 impl<ChannelSigner: EcdsaChannelSigner> OnchainTxHandler<ChannelSigner> {
305 pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
306 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
308 self.destination_script.write(writer)?;
309 self.holder_commitment.write(writer)?;
310 None::<Option<Vec<Option<(usize, Signature)>>>>.write(writer)?; // holder_htlc_sigs
311 self.prev_holder_commitment.write(writer)?;
312 None::<Option<Vec<Option<(usize, Signature)>>>>.write(writer)?; // prev_holder_htlc_sigs
314 self.channel_transaction_parameters.write(writer)?;
316 // Write a zero-length signer. The data is no longer deserialized as of version 0.0.113 and
317 // downgrades before version 0.0.113 are no longer supported as of version 0.0.119.
320 writer.write_all(&(self.pending_claim_requests.len() as u64).to_be_bytes())?;
321 for (ref ancestor_claim_txid, request) in self.pending_claim_requests.iter() {
322 ancestor_claim_txid.write(writer)?;
323 request.write(writer)?;
326 writer.write_all(&(self.claimable_outpoints.len() as u64).to_be_bytes())?;
327 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
329 claim_and_height.0.write(writer)?;
330 claim_and_height.1.write(writer)?;
333 writer.write_all(&(self.locktimed_packages.len() as u64).to_be_bytes())?;
334 for (ref locktime, ref packages) in self.locktimed_packages.iter() {
335 locktime.write(writer)?;
336 writer.write_all(&(packages.len() as u64).to_be_bytes())?;
337 for ref package in packages.iter() {
338 package.write(writer)?;
342 writer.write_all(&(self.onchain_events_awaiting_threshold_conf.len() as u64).to_be_bytes())?;
343 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
344 entry.write(writer)?;
347 write_tlv_fields!(writer, {});
352 impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP, u64, [u8; 32])> for OnchainTxHandler<SP::EcdsaSigner> {
353 fn read<R: io::Read>(reader: &mut R, args: (&'a ES, &'b SP, u64, [u8; 32])) -> Result<Self, DecodeError> {
354 let entropy_source = args.0;
355 let signer_provider = args.1;
356 let channel_value_satoshis = args.2;
357 let channel_keys_id = args.3;
359 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
361 let destination_script = Readable::read(reader)?;
363 let holder_commitment = Readable::read(reader)?;
364 let _holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>> = Readable::read(reader)?;
365 let prev_holder_commitment = Readable::read(reader)?;
366 let _prev_holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>> = Readable::read(reader)?;
368 let channel_parameters = Readable::read(reader)?;
370 // Read the serialized signer bytes, but don't deserialize them, as we'll obtain our signer
371 // by re-deriving the private key material.
372 let keys_len: u32 = Readable::read(reader)?;
373 let mut bytes_read = 0;
374 while bytes_read != keys_len as usize {
375 // Read 1KB at a time to avoid accidentally allocating 4GB on corrupted channel keys
376 let mut data = [0; 1024];
377 let bytes_to_read = cmp::min(1024, keys_len as usize - bytes_read);
378 let read_slice = &mut data[0..bytes_to_read];
379 reader.read_exact(read_slice)?;
380 bytes_read += bytes_to_read;
383 let mut signer = signer_provider.derive_channel_signer(channel_value_satoshis, channel_keys_id);
384 signer.provide_channel_parameters(&channel_parameters);
386 let pending_claim_requests_len: u64 = Readable::read(reader)?;
387 let mut pending_claim_requests = hash_map_with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
388 for _ in 0..pending_claim_requests_len {
389 pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
392 let claimable_outpoints_len: u64 = Readable::read(reader)?;
393 let mut claimable_outpoints = hash_map_with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
394 for _ in 0..claimable_outpoints_len {
395 let outpoint = Readable::read(reader)?;
396 let ancestor_claim_txid = Readable::read(reader)?;
397 let height = Readable::read(reader)?;
398 claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
401 let locktimed_packages_len: u64 = Readable::read(reader)?;
402 let mut locktimed_packages = BTreeMap::new();
403 for _ in 0..locktimed_packages_len {
404 let locktime = Readable::read(reader)?;
405 let packages_len: u64 = Readable::read(reader)?;
406 let mut packages = Vec::with_capacity(cmp::min(packages_len as usize, MAX_ALLOC_SIZE / core::mem::size_of::<PackageTemplate>()));
407 for _ in 0..packages_len {
408 packages.push(Readable::read(reader)?);
410 locktimed_packages.insert(locktime, packages);
413 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
414 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
415 for _ in 0..waiting_threshold_conf_len {
416 if let Some(val) = MaybeReadable::read(reader)? {
417 onchain_events_awaiting_threshold_conf.push(val);
421 read_tlv_fields!(reader, {});
423 let mut secp_ctx = Secp256k1::new();
424 secp_ctx.seeded_randomize(&entropy_source.get_secure_random_bytes());
426 Ok(OnchainTxHandler {
427 channel_value_satoshis,
431 prev_holder_commitment,
433 channel_transaction_parameters: channel_parameters,
436 pending_claim_requests,
437 onchain_events_awaiting_threshold_conf,
438 pending_claim_events: Vec::new(),
444 impl<ChannelSigner: EcdsaChannelSigner> OnchainTxHandler<ChannelSigner> {
446 channel_value_satoshis: u64, channel_keys_id: [u8; 32], destination_script: ScriptBuf,
447 signer: ChannelSigner, channel_parameters: ChannelTransactionParameters,
448 holder_commitment: HolderCommitmentTransaction, secp_ctx: Secp256k1<secp256k1::All>
451 channel_value_satoshis,
455 prev_holder_commitment: None,
457 channel_transaction_parameters: channel_parameters,
458 pending_claim_requests: new_hash_map(),
459 claimable_outpoints: new_hash_map(),
460 locktimed_packages: BTreeMap::new(),
461 onchain_events_awaiting_threshold_conf: Vec::new(),
462 pending_claim_events: Vec::new(),
467 pub(crate) fn get_prev_holder_commitment_to_self_value(&self) -> Option<u64> {
468 self.prev_holder_commitment.as_ref().map(|commitment| commitment.to_broadcaster_value_sat())
471 pub(crate) fn get_cur_holder_commitment_to_self_value(&self) -> u64 {
472 self.holder_commitment.to_broadcaster_value_sat()
475 pub(crate) fn get_and_clear_pending_claim_events(&mut self) -> Vec<(ClaimId, ClaimEvent)> {
476 let mut events = Vec::new();
477 swap(&mut events, &mut self.pending_claim_events);
481 /// Triggers rebroadcasts/fee-bumps of pending claims from a force-closed channel. This is
482 /// crucial in preventing certain classes of pinning attacks, detecting substantial mempool
483 /// feerate changes between blocks, and ensuring reliability if broadcasting fails. We recommend
484 /// invoking this every 30 seconds, or lower if running in an environment with spotty
485 /// connections, like on mobile.
486 pub(super) fn rebroadcast_pending_claims<B: Deref, F: Deref, L: Logger>(
487 &mut self, current_height: u32, feerate_strategy: FeerateStrategy, broadcaster: &B,
488 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L,
491 B::Target: BroadcasterInterface,
492 F::Target: FeeEstimator,
494 let mut bump_requests = Vec::with_capacity(self.pending_claim_requests.len());
495 for (claim_id, request) in self.pending_claim_requests.iter() {
496 let inputs = request.outpoints();
497 log_info!(logger, "Triggering rebroadcast/fee-bump for request with inputs {:?}", inputs);
498 bump_requests.push((*claim_id, request.clone()));
500 for (claim_id, request) in bump_requests {
501 self.generate_claim(current_height, &request, &feerate_strategy, fee_estimator, logger)
502 .map(|(_, new_feerate, claim)| {
503 let mut bumped_feerate = false;
504 if let Some(mut_request) = self.pending_claim_requests.get_mut(&claim_id) {
505 bumped_feerate = request.previous_feerate() > new_feerate;
506 mut_request.set_feerate(new_feerate);
509 OnchainClaim::Tx(tx) => {
510 if tx.is_fully_signed() {
511 let log_start = if bumped_feerate { "Broadcasting RBF-bumped" } else { "Rebroadcasting" };
512 log_info!(logger, "{} onchain {}", log_start, log_tx!(tx.0));
513 broadcaster.broadcast_transactions(&[&tx.0]);
515 log_info!(logger, "Waiting for signature of unsigned onchain transaction {}", tx.0.txid());
518 OnchainClaim::Event(event) => {
519 let log_start = if bumped_feerate { "Yielding fee-bumped" } else { "Replaying" };
520 log_info!(logger, "{} onchain event to spend inputs {:?}", log_start,
521 request.outpoints());
522 #[cfg(debug_assertions)] {
523 debug_assert!(request.requires_external_funding());
524 let num_existing = self.pending_claim_events.iter()
525 .filter(|entry| entry.0 == claim_id).count();
526 assert!(num_existing == 0 || num_existing == 1);
528 self.pending_claim_events.retain(|event| event.0 != claim_id);
529 self.pending_claim_events.push((claim_id, event));
536 /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize counterparty
537 /// onchain) lays on the assumption of claim transactions getting confirmed before timelock
538 /// expiration (CSV or CLTV following cases). In case of high-fee spikes, claim tx may get stuck
539 /// in the mempool, so you need to bump its feerate quickly using Replace-By-Fee or
540 /// Child-Pay-For-Parent.
542 /// Panics if there are signing errors, because signing operations in reaction to on-chain
543 /// events are not expected to fail, and if they do, we may lose funds.
544 fn generate_claim<F: Deref, L: Logger>(
545 &mut self, cur_height: u32, cached_request: &PackageTemplate, feerate_strategy: &FeerateStrategy,
546 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L,
547 ) -> Option<(u32, u64, OnchainClaim)>
548 where F::Target: FeeEstimator,
550 let request_outpoints = cached_request.outpoints();
551 if request_outpoints.is_empty() {
552 // Don't prune pending claiming request yet, we may have to resurrect HTLCs. Untractable
553 // packages cannot be aggregated and will never be split, so we cannot end up with an
555 debug_assert!(cached_request.is_malleable());
558 // If we've seen transaction inclusion in the chain for all outpoints in our request, we
559 // don't need to continue generating more claims. We'll keep tracking the request to fully
560 // remove it once it reaches the confirmation threshold, or to generate a new claim if the
561 // transaction is reorged out.
562 let mut all_inputs_have_confirmed_spend = true;
563 for outpoint in request_outpoints.iter() {
564 if let Some((request_claim_id, _)) = self.claimable_outpoints.get(*outpoint) {
565 // We check for outpoint spends within claims individually rather than as a set
566 // since requests can have outpoints split off.
567 if !self.onchain_events_awaiting_threshold_conf.iter()
568 .any(|event_entry| if let OnchainEvent::Claim { claim_id } = event_entry.event {
569 *request_claim_id == claim_id
571 // The onchain event is not a claim, keep seeking until we find one.
575 // Either we had no `OnchainEvent::Claim`, or we did but none matched the
576 // outpoint's registered spend.
577 all_inputs_have_confirmed_spend = false;
580 // The request's outpoint spend does not exist yet.
581 all_inputs_have_confirmed_spend = false;
584 if all_inputs_have_confirmed_spend {
588 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
589 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
590 let new_timer = cached_request.get_height_timer(cur_height);
591 if cached_request.is_malleable() {
592 if cached_request.requires_external_funding() {
593 let target_feerate_sat_per_1000_weight = cached_request.compute_package_feerate(
594 fee_estimator, ConfirmationTarget::OnChainSweep, feerate_strategy,
596 if let Some(htlcs) = cached_request.construct_malleable_package_with_external_funding(self) {
599 target_feerate_sat_per_1000_weight as u64,
600 OnchainClaim::Event(ClaimEvent::BumpHTLC {
601 target_feerate_sat_per_1000_weight,
603 tx_lock_time: LockTime::from_consensus(cached_request.package_locktime(cur_height)),
611 let predicted_weight = cached_request.package_weight(&self.destination_script);
612 if let Some((output_value, new_feerate)) = cached_request.compute_package_output(
613 predicted_weight, self.destination_script.dust_value().to_sat(),
614 feerate_strategy, fee_estimator, logger,
616 assert!(new_feerate != 0);
618 let transaction = cached_request.maybe_finalize_malleable_package(
619 cur_height, self, Amount::from_sat(output_value), self.destination_script.clone(), logger
621 assert!(predicted_weight >= transaction.0.weight().to_wu());
622 return Some((new_timer, new_feerate, OnchainClaim::Tx(transaction)));
625 // Untractable packages cannot have their fees bumped through Replace-By-Fee. Some
626 // packages may support fee bumping through Child-Pays-For-Parent, indicated by those
627 // which require external funding.
628 let mut inputs = cached_request.inputs();
629 debug_assert_eq!(inputs.len(), 1);
630 let tx = match cached_request.maybe_finalize_untractable_package(self, logger) {
634 if !cached_request.requires_external_funding() {
635 return Some((new_timer, 0, OnchainClaim::Tx(tx)));
637 return inputs.find_map(|input| match input {
638 // Commitment inputs with anchors support are the only untractable inputs supported
639 // thus far that require external funding.
640 PackageSolvingData::HolderFundingOutput(output) => {
641 debug_assert_eq!(tx.0.txid(), self.holder_commitment.trust().txid(),
642 "Holder commitment transaction mismatch");
644 let conf_target = ConfirmationTarget::OnChainSweep;
645 let package_target_feerate_sat_per_1000_weight = cached_request
646 .compute_package_feerate(fee_estimator, conf_target, feerate_strategy);
647 if let Some(input_amount_sat) = output.funding_amount {
648 let fee_sat = input_amount_sat - tx.0.output.iter().map(|output| output.value.to_sat()).sum::<u64>();
649 let commitment_tx_feerate_sat_per_1000_weight =
650 compute_feerate_sat_per_1000_weight(fee_sat, tx.0.weight().to_wu());
651 if commitment_tx_feerate_sat_per_1000_weight >= package_target_feerate_sat_per_1000_weight {
652 log_debug!(logger, "Pre-signed commitment {} already has feerate {} sat/kW above required {} sat/kW",
653 tx.0.txid(), commitment_tx_feerate_sat_per_1000_weight,
654 package_target_feerate_sat_per_1000_weight);
655 return Some((new_timer, 0, OnchainClaim::Tx(tx.clone())));
659 // We'll locate an anchor output we can spend within the commitment transaction.
660 let funding_pubkey = &self.channel_transaction_parameters.holder_pubkeys.funding_pubkey;
661 match chan_utils::get_anchor_output(&tx.0, funding_pubkey) {
662 // An anchor output was found, so we should yield a funding event externally.
664 // TODO: Use a lower confirmation target when both our and the
665 // counterparty's latest commitment don't have any HTLCs present.
668 package_target_feerate_sat_per_1000_weight as u64,
669 OnchainClaim::Event(ClaimEvent::BumpCommitment {
670 package_target_feerate_sat_per_1000_weight,
671 commitment_tx: tx.0.clone(),
672 anchor_output_idx: idx,
676 // An anchor output was not found. There's nothing we can do other than
677 // attempt to broadcast the transaction with its current fee rate and hope
678 // it confirms. This is essentially the same behavior as a commitment
679 // transaction without anchor outputs.
680 None => Some((new_timer, 0, OnchainClaim::Tx(tx.clone()))),
684 debug_assert!(false, "Only HolderFundingOutput inputs should be untractable and require external funding");
692 pub fn abandon_claim(&mut self, outpoint: &BitcoinOutPoint) {
693 let claim_id = self.claimable_outpoints.get(outpoint).map(|(claim_id, _)| *claim_id)
695 self.pending_claim_requests.iter()
696 .find(|(_, claim)| claim.outpoints().iter().any(|claim_outpoint| *claim_outpoint == outpoint))
697 .map(|(claim_id, _)| *claim_id)
699 if let Some(claim_id) = claim_id {
700 if let Some(claim) = self.pending_claim_requests.remove(&claim_id) {
701 for outpoint in claim.outpoints() {
702 self.claimable_outpoints.remove(outpoint);
706 self.locktimed_packages.values_mut().for_each(|claims|
707 claims.retain(|claim| !claim.outpoints().iter().any(|claim_outpoint| *claim_outpoint == outpoint)));
711 /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
712 /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
713 /// Together with `update_claims_view_from_matched_txn` this used to be named
714 /// `block_connected`, but it is now also used for claiming an HTLC output if we receive a
715 /// preimage after force-close.
717 /// `conf_height` represents the height at which the request was generated. This
718 /// does not need to equal the current blockchain tip height, which should be provided via
719 /// `cur_height`, however it must never be higher than `cur_height`.
720 pub(super) fn update_claims_view_from_requests<B: Deref, F: Deref, L: Logger>(
721 &mut self, requests: Vec<PackageTemplate>, conf_height: u32, cur_height: u32,
722 broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L
724 B::Target: BroadcasterInterface,
725 F::Target: FeeEstimator,
727 if !requests.is_empty() {
728 log_debug!(logger, "Updating claims view at height {} with {} claim requests", cur_height, requests.len());
731 let mut preprocessed_requests = Vec::with_capacity(requests.len());
732 let mut aggregated_request = None;
734 // Try to aggregate outputs if their timelock expiration isn't imminent (package timelock
735 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
736 for req in requests {
737 // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
738 if let Some(_) = self.claimable_outpoints.get(req.outpoints()[0]) {
739 log_info!(logger, "Ignoring second claim for outpoint {}:{}, already registered its claiming request", req.outpoints()[0].txid, req.outpoints()[0].vout);
741 let timelocked_equivalent_package = self.locktimed_packages.iter().map(|v| v.1.iter()).flatten()
742 .find(|locked_package| locked_package.outpoints() == req.outpoints());
743 if let Some(package) = timelocked_equivalent_package {
744 log_info!(logger, "Ignoring second claim for outpoint {}:{}, we already have one which we're waiting on a timelock at {} for.",
745 req.outpoints()[0].txid, req.outpoints()[0].vout, package.package_locktime(cur_height));
749 let package_locktime = req.package_locktime(cur_height);
750 if package_locktime > cur_height + 1 {
751 log_info!(logger, "Delaying claim of package until its timelock at {} (current height {}), the following outpoints are spent:", package_locktime, cur_height);
752 for outpoint in req.outpoints() {
753 log_info!(logger, " Outpoint {}", outpoint);
755 self.locktimed_packages.entry(package_locktime).or_insert(Vec::new()).push(req);
759 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.timelock(), cur_height + CLTV_SHARED_CLAIM_BUFFER);
760 if req.timelock() <= cur_height + CLTV_SHARED_CLAIM_BUFFER || !req.aggregable() {
761 // Don't aggregate if outpoint package timelock is soon or marked as non-aggregable
762 preprocessed_requests.push(req);
763 } else if aggregated_request.is_none() {
764 aggregated_request = Some(req);
766 aggregated_request.as_mut().unwrap().merge_package(req);
770 if let Some(req) = aggregated_request {
771 preprocessed_requests.push(req);
774 // Claim everything up to and including `cur_height`
775 let remaining_locked_packages = self.locktimed_packages.split_off(&(cur_height + 1));
776 if !self.locktimed_packages.is_empty() {
778 "Updating claims view at height {} with {} locked packages available for claim",
780 self.locktimed_packages.len());
782 for (pop_height, mut entry) in self.locktimed_packages.iter_mut() {
783 log_trace!(logger, "Restoring delayed claim of package(s) at their timelock at {}.", pop_height);
784 preprocessed_requests.append(&mut entry);
786 self.locktimed_packages = remaining_locked_packages;
788 // Generate claim transactions and track them to bump if necessary at
789 // height timer expiration (i.e in how many blocks we're going to take action).
790 for mut req in preprocessed_requests {
791 if let Some((new_timer, new_feerate, claim)) = self.generate_claim(
792 cur_height, &req, &FeerateStrategy::ForceBump, &*fee_estimator, &*logger,
794 req.set_timer(new_timer);
795 req.set_feerate(new_feerate);
796 // Once a pending claim has an id assigned, it remains fixed until the claim is
797 // satisfied, regardless of whether the claim switches between different variants of
799 let claim_id = match claim {
800 OnchainClaim::Tx(tx) => {
801 if tx.is_fully_signed() {
802 log_info!(logger, "Broadcasting onchain {}", log_tx!(tx.0));
803 broadcaster.broadcast_transactions(&[&tx.0]);
805 log_info!(logger, "Waiting for signature of unsigned onchain transaction {}", tx.0.txid());
807 ClaimId(tx.0.txid().to_byte_array())
809 OnchainClaim::Event(claim_event) => {
810 log_info!(logger, "Yielding onchain event to spend inputs {:?}", req.outpoints());
811 let claim_id = match claim_event {
812 ClaimEvent::BumpCommitment { ref commitment_tx, .. } =>
813 // For commitment claims, we can just use their txid as it should
814 // already be unique.
815 ClaimId(commitment_tx.txid().to_byte_array()),
816 ClaimEvent::BumpHTLC { ref htlcs, .. } => {
817 // For HTLC claims, commit to the entire set of HTLC outputs to
818 // claim, which will always be unique per request. Once a claim ID
819 // is generated, it is assigned and remains unchanged, even if the
820 // underlying set of HTLCs changes.
821 let mut engine = Sha256::engine();
823 engine.input(&htlc.commitment_txid.to_byte_array());
824 engine.input(&htlc.htlc.transaction_output_index.unwrap().to_be_bytes());
826 ClaimId(Sha256::from_engine(engine).to_byte_array())
829 debug_assert!(self.pending_claim_requests.get(&claim_id).is_none());
830 debug_assert_eq!(self.pending_claim_events.iter().filter(|entry| entry.0 == claim_id).count(), 0);
831 self.pending_claim_events.push((claim_id, claim_event));
835 // Because fuzzing can cause hash collisions, we can end up with conflicting claim
836 // ids here, so we only assert when not fuzzing.
837 debug_assert!(cfg!(fuzzing) || self.pending_claim_requests.get(&claim_id).is_none());
838 for k in req.outpoints() {
839 log_info!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
840 self.claimable_outpoints.insert(k.clone(), (claim_id, conf_height));
842 self.pending_claim_requests.insert(claim_id, req);
847 /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
848 /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
849 /// Together with `update_claims_view_from_requests` this used to be named `block_connected`,
850 /// but it is now also used for claiming an HTLC output if we receive a preimage after force-close.
852 /// `conf_height` represents the height at which the transactions in `txn_matched` were
853 /// confirmed. This does not need to equal the current blockchain tip height, which should be
854 /// provided via `cur_height`, however it must never be higher than `cur_height`.
855 pub(super) fn update_claims_view_from_matched_txn<B: Deref, F: Deref, L: Logger>(
856 &mut self, txn_matched: &[&Transaction], conf_height: u32, conf_hash: BlockHash,
857 cur_height: u32, broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L
859 B::Target: BroadcasterInterface,
860 F::Target: FeeEstimator,
862 let mut have_logged_intro = false;
863 let mut maybe_log_intro = || {
864 if !have_logged_intro {
865 log_debug!(logger, "Updating claims view at height {} with {} matched transactions in block {}", cur_height, txn_matched.len(), conf_height);
866 have_logged_intro = true;
869 let mut bump_candidates = new_hash_map();
870 if !txn_matched.is_empty() { maybe_log_intro(); }
871 for tx in txn_matched {
872 // Scan all input to verify is one of the outpoint spent is of interest for us
873 let mut claimed_outputs_material = Vec::new();
874 for inp in &tx.input {
875 if let Some((claim_id, _)) = self.claimable_outpoints.get(&inp.previous_output) {
876 // If outpoint has claim request pending on it...
877 if let Some(request) = self.pending_claim_requests.get_mut(claim_id) {
878 //... we need to verify equality between transaction outpoints and claim request
879 // outpoints to know if transaction is the original claim or a bumped one issued
881 let mut are_sets_equal = true;
882 let mut tx_inputs = tx.input.iter().map(|input| &input.previous_output).collect::<Vec<_>>();
883 tx_inputs.sort_unstable();
884 for request_input in request.outpoints() {
885 if tx_inputs.binary_search(&request_input).is_err() {
886 are_sets_equal = false;
891 macro_rules! clean_claim_request_after_safety_delay {
893 let entry = OnchainEventEntry {
896 block_hash: Some(conf_hash),
897 event: OnchainEvent::Claim { claim_id: *claim_id }
899 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
900 self.onchain_events_awaiting_threshold_conf.push(entry);
905 // If this is our transaction (or our counterparty spent all the outputs
906 // before we could anyway with same inputs order than us), wait for
907 // ANTI_REORG_DELAY and clean the RBF tracking map.
909 clean_claim_request_after_safety_delay!();
910 } else { // If false, generate new claim request with update outpoint set
911 let mut at_least_one_drop = false;
912 for input in tx.input.iter() {
913 if let Some(package) = request.split_package(&input.previous_output) {
914 claimed_outputs_material.push(package);
915 at_least_one_drop = true;
917 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
918 if request.outpoints().is_empty() {
919 clean_claim_request_after_safety_delay!();
922 //TODO: recompute soonest_timelock to avoid wasting a bit on fees
923 if at_least_one_drop {
924 bump_candidates.insert(*claim_id, request.clone());
925 // If we have any pending claim events for the request being updated
926 // that have yet to be consumed, we'll remove them since they will
927 // end up producing an invalid transaction by double spending
928 // input(s) that already have a confirmed spend. If such spend is
929 // reorged out of the chain, then we'll attempt to re-spend the
930 // inputs once we see it.
931 #[cfg(debug_assertions)] {
932 let existing = self.pending_claim_events.iter()
933 .filter(|entry| entry.0 == *claim_id).count();
934 assert!(existing == 0 || existing == 1);
936 self.pending_claim_events.retain(|entry| entry.0 != *claim_id);
939 break; //No need to iterate further, either tx is our or their
941 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
945 for package in claimed_outputs_material.drain(..) {
946 let entry = OnchainEventEntry {
949 block_hash: Some(conf_hash),
950 event: OnchainEvent::ContentiousOutpoint { package },
952 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
953 self.onchain_events_awaiting_threshold_conf.push(entry);
958 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
959 let onchain_events_awaiting_threshold_conf =
960 self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
961 for entry in onchain_events_awaiting_threshold_conf {
962 if entry.has_reached_confirmation_threshold(cur_height) {
965 OnchainEvent::Claim { claim_id } => {
966 // We may remove a whole set of claim outpoints here, as these one may have
967 // been aggregated in a single tx and claimed so atomically
968 if let Some(request) = self.pending_claim_requests.remove(&claim_id) {
969 for outpoint in request.outpoints() {
970 log_debug!(logger, "Removing claim tracking for {} due to maturation of claim package {}.",
971 outpoint, log_bytes!(claim_id.0));
972 self.claimable_outpoints.remove(outpoint);
974 #[cfg(debug_assertions)] {
975 let num_existing = self.pending_claim_events.iter()
976 .filter(|entry| entry.0 == claim_id).count();
977 assert!(num_existing == 0 || num_existing == 1);
979 self.pending_claim_events.retain(|(id, _)| *id != claim_id);
982 OnchainEvent::ContentiousOutpoint { package } => {
983 log_debug!(logger, "Removing claim tracking due to maturation of claim tx for outpoints:");
984 log_debug!(logger, " {:?}", package.outpoints());
985 self.claimable_outpoints.remove(package.outpoints()[0]);
989 self.onchain_events_awaiting_threshold_conf.push(entry);
993 // Check if any pending claim request must be rescheduled
994 for (claim_id, request) in self.pending_claim_requests.iter() {
995 if cur_height >= request.timer() {
996 bump_candidates.insert(*claim_id, request.clone());
1000 // Build, bump and rebroadcast tx accordingly
1001 if !bump_candidates.is_empty() {
1003 log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
1006 for (claim_id, request) in bump_candidates.iter() {
1007 if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(
1008 cur_height, &request, &FeerateStrategy::ForceBump, &*fee_estimator, &*logger,
1011 OnchainClaim::Tx(bump_tx) => {
1012 if bump_tx.is_fully_signed() {
1013 log_info!(logger, "Broadcasting RBF-bumped onchain {}", log_tx!(bump_tx.0));
1014 broadcaster.broadcast_transactions(&[&bump_tx.0]);
1016 log_info!(logger, "Waiting for signature of RBF-bumped unsigned onchain transaction {}",
1020 OnchainClaim::Event(claim_event) => {
1021 log_info!(logger, "Yielding RBF-bumped onchain event to spend inputs {:?}", request.outpoints());
1022 #[cfg(debug_assertions)] {
1023 let num_existing = self.pending_claim_events.iter().
1024 filter(|entry| entry.0 == *claim_id).count();
1025 assert!(num_existing == 0 || num_existing == 1);
1027 self.pending_claim_events.retain(|event| event.0 != *claim_id);
1028 self.pending_claim_events.push((*claim_id, claim_event));
1031 if let Some(request) = self.pending_claim_requests.get_mut(claim_id) {
1032 request.set_timer(new_timer);
1033 request.set_feerate(new_feerate);
1039 pub(super) fn transaction_unconfirmed<B: Deref, F: Deref, L: Logger>(
1043 fee_estimator: &LowerBoundedFeeEstimator<F>,
1046 B::Target: BroadcasterInterface,
1047 F::Target: FeeEstimator,
1049 let mut height = None;
1050 for entry in self.onchain_events_awaiting_threshold_conf.iter() {
1051 if entry.txid == *txid {
1052 height = Some(entry.height);
1057 if let Some(height) = height {
1058 self.block_disconnected(height, broadcaster, fee_estimator, logger);
1062 pub(super) fn block_disconnected<B: Deref, F: Deref, L: Logger>(&mut self, height: u32, broadcaster: B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L)
1063 where B::Target: BroadcasterInterface,
1064 F::Target: FeeEstimator,
1066 let mut bump_candidates = new_hash_map();
1067 let onchain_events_awaiting_threshold_conf =
1068 self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
1069 for entry in onchain_events_awaiting_threshold_conf {
1070 if entry.height >= height {
1071 //- our claim tx on a commitment tx output
1072 //- resurect outpoint back in its claimable set and regenerate tx
1074 OnchainEvent::ContentiousOutpoint { package } => {
1075 if let Some(pending_claim) = self.claimable_outpoints.get(package.outpoints()[0]) {
1076 if let Some(request) = self.pending_claim_requests.get_mut(&pending_claim.0) {
1077 request.merge_package(package);
1078 // Using a HashMap guarantee us than if we have multiple outpoints getting
1079 // resurrected only one bump claim tx is going to be broadcast
1080 bump_candidates.insert(pending_claim.clone(), request.clone());
1087 self.onchain_events_awaiting_threshold_conf.push(entry);
1090 for ((_claim_id, _), ref mut request) in bump_candidates.iter_mut() {
1091 // `height` is the height being disconnected, so our `current_height` is 1 lower.
1092 let current_height = height - 1;
1093 if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(
1094 current_height, &request, &FeerateStrategy::ForceBump, fee_estimator, logger
1096 request.set_timer(new_timer);
1097 request.set_feerate(new_feerate);
1099 OnchainClaim::Tx(bump_tx) => {
1100 if bump_tx.is_fully_signed() {
1101 log_info!(logger, "Broadcasting onchain {}", log_tx!(bump_tx.0));
1102 broadcaster.broadcast_transactions(&[&bump_tx.0]);
1104 log_info!(logger, "Waiting for signature of unsigned onchain transaction {}", bump_tx.0.txid());
1107 OnchainClaim::Event(claim_event) => {
1108 log_info!(logger, "Yielding onchain event after reorg to spend inputs {:?}", request.outpoints());
1109 #[cfg(debug_assertions)] {
1110 let num_existing = self.pending_claim_events.iter()
1111 .filter(|entry| entry.0 == *_claim_id).count();
1112 assert!(num_existing == 0 || num_existing == 1);
1114 self.pending_claim_events.retain(|event| event.0 != *_claim_id);
1115 self.pending_claim_events.push((*_claim_id, claim_event));
1120 for (ancestor_claim_txid, request) in bump_candidates.drain() {
1121 self.pending_claim_requests.insert(ancestor_claim_txid.0, request);
1123 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
1124 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
1125 let mut remove_request = Vec::new();
1126 self.claimable_outpoints.retain(|_, ref v|
1128 remove_request.push(v.0.clone());
1131 for req in remove_request {
1132 self.pending_claim_requests.remove(&req);
1136 pub(crate) fn is_output_spend_pending(&self, outpoint: &BitcoinOutPoint) -> bool {
1137 self.claimable_outpoints.get(outpoint).is_some()
1140 pub(crate) fn get_relevant_txids(&self) -> Vec<(Txid, u32, Option<BlockHash>)> {
1141 let mut txids: Vec<(Txid, u32, Option<BlockHash>)> = self.onchain_events_awaiting_threshold_conf
1143 .map(|entry| (entry.txid, entry.height, entry.block_hash))
1145 txids.sort_unstable_by(|a, b| a.0.cmp(&b.0).then(b.1.cmp(&a.1)));
1146 txids.dedup_by_key(|(txid, _, _)| *txid);
1150 pub(crate) fn provide_latest_holder_tx(&mut self, tx: HolderCommitmentTransaction) {
1151 self.prev_holder_commitment = Some(replace(&mut self.holder_commitment, tx));
1154 pub(crate) fn get_unsigned_holder_commitment_tx(&self) -> &Transaction {
1155 &self.holder_commitment.trust().built_transaction().transaction
1158 pub(crate) fn get_maybe_signed_holder_tx(&mut self, funding_redeemscript: &Script) -> MaybeSignedTransaction {
1159 let tx = self.signer.sign_holder_commitment(&self.holder_commitment, &self.secp_ctx)
1160 .map(|sig| self.holder_commitment.add_holder_sig(funding_redeemscript, sig))
1161 .unwrap_or_else(|_| self.get_unsigned_holder_commitment_tx().clone());
1162 MaybeSignedTransaction(tx)
1165 #[cfg(any(test, feature="unsafe_revoked_tx_signing"))]
1166 pub(crate) fn get_fully_signed_copy_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
1167 let sig = self.signer.unsafe_sign_holder_commitment(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
1168 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
1171 pub(crate) fn get_maybe_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<MaybeSignedTransaction> {
1172 let get_signed_htlc_tx = |holder_commitment: &HolderCommitmentTransaction| {
1173 let trusted_tx = holder_commitment.trust();
1174 if trusted_tx.txid() != outp.txid {
1177 let (htlc_idx, htlc) = trusted_tx.htlcs().iter().enumerate()
1178 .find(|(_, htlc)| htlc.transaction_output_index.unwrap() == outp.vout)
1180 let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[htlc_idx];
1181 let mut htlc_tx = trusted_tx.build_unsigned_htlc_tx(
1182 &self.channel_transaction_parameters.as_holder_broadcastable(), htlc_idx, preimage,
1185 let htlc_descriptor = HTLCDescriptor {
1186 channel_derivation_parameters: ChannelDerivationParameters {
1187 value_satoshis: self.channel_value_satoshis,
1188 keys_id: self.channel_keys_id,
1189 transaction_parameters: self.channel_transaction_parameters.clone(),
1191 commitment_txid: trusted_tx.txid(),
1192 per_commitment_number: trusted_tx.commitment_number(),
1193 per_commitment_point: trusted_tx.per_commitment_point(),
1194 feerate_per_kw: trusted_tx.feerate_per_kw(),
1196 preimage: preimage.clone(),
1197 counterparty_sig: counterparty_htlc_sig.clone(),
1199 if let Ok(htlc_sig) = self.signer.sign_holder_htlc_transaction(&htlc_tx, 0, &htlc_descriptor, &self.secp_ctx) {
1200 htlc_tx.input[0].witness = trusted_tx.build_htlc_input_witness(
1201 htlc_idx, &counterparty_htlc_sig, &htlc_sig, preimage,
1204 Some(MaybeSignedTransaction(htlc_tx))
1207 // Check if the HTLC spends from the current holder commitment first, or the previous.
1208 get_signed_htlc_tx(&self.holder_commitment)
1209 .or_else(|| self.prev_holder_commitment.as_ref().and_then(|prev_holder_commitment| get_signed_htlc_tx(prev_holder_commitment)))
1212 pub(crate) fn generate_external_htlc_claim(
1213 &self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>
1214 ) -> Option<ExternalHTLCClaim> {
1215 let find_htlc = |holder_commitment: &HolderCommitmentTransaction| -> Option<ExternalHTLCClaim> {
1216 let trusted_tx = holder_commitment.trust();
1217 if outp.txid != trusted_tx.txid() {
1220 trusted_tx.htlcs().iter().enumerate()
1221 .find(|(_, htlc)| if let Some(output_index) = htlc.transaction_output_index {
1222 output_index == outp.vout
1226 .map(|(htlc_idx, htlc)| {
1227 let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[htlc_idx];
1229 commitment_txid: trusted_tx.txid(),
1230 per_commitment_number: trusted_tx.commitment_number(),
1232 preimage: *preimage,
1233 counterparty_sig: counterparty_htlc_sig,
1237 // Check if the HTLC spends from the current holder commitment or the previous one otherwise.
1238 find_htlc(&self.holder_commitment)
1239 .or_else(|| self.prev_holder_commitment.as_ref().map(|c| find_htlc(c)).flatten())
1242 pub(crate) fn channel_type_features(&self) -> &ChannelTypeFeatures {
1243 &self.channel_transaction_parameters.channel_type_features