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.
16 use bitcoin::PackedLockTime;
17 use bitcoin::blockdata::transaction::Transaction;
18 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
19 use bitcoin::blockdata::script::Script;
20 use bitcoin::hashes::Hash;
22 use bitcoin::hashes::HashEngine;
24 use bitcoin::hashes::sha256::Hash as Sha256;
25 use bitcoin::hash_types::{Txid, BlockHash};
26 use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature};
27 use bitcoin::secp256k1;
29 use crate::sign::{ChannelSigner, EntropySource, SignerProvider};
30 use crate::ln::msgs::DecodeError;
31 use crate::ln::PaymentPreimage;
33 use crate::ln::chan_utils::{self, HTLCOutputInCommitment};
34 use crate::ln::chan_utils::{ChannelTransactionParameters, HolderCommitmentTransaction};
35 use crate::chain::ClaimId;
37 use crate::chain::chaininterface::ConfirmationTarget;
38 use crate::chain::chaininterface::{FeeEstimator, BroadcasterInterface, LowerBoundedFeeEstimator};
39 use crate::chain::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER};
40 use crate::sign::WriteableEcdsaChannelSigner;
42 use crate::chain::package::PackageSolvingData;
43 use crate::chain::package::PackageTemplate;
44 use crate::util::logger::Logger;
45 use crate::util::ser::{Readable, ReadableArgs, MaybeReadable, UpgradableRequired, Writer, Writeable, VecWriter};
48 use crate::prelude::*;
49 use alloc::collections::BTreeMap;
52 use core::mem::replace;
56 const MAX_ALLOC_SIZE: usize = 64*1024;
58 /// An entry for an [`OnchainEvent`], stating the block height when the event was observed and the
59 /// transaction causing it.
61 /// Used to determine when the on-chain event can be considered safe from a chain reorganization.
62 #[derive(PartialEq, Eq)]
63 struct OnchainEventEntry {
66 block_hash: Option<BlockHash>, // Added as optional, will be filled in for any entry generated on 0.0.113 or after
70 impl OnchainEventEntry {
71 fn confirmation_threshold(&self) -> u32 {
72 self.height + ANTI_REORG_DELAY - 1
75 fn has_reached_confirmation_threshold(&self, height: u32) -> bool {
76 height >= self.confirmation_threshold()
80 /// Events for claims the [`OnchainTxHandler`] has generated. Once the events are considered safe
81 /// from a chain reorg, the [`OnchainTxHandler`] will act accordingly.
82 #[derive(PartialEq, Eq)]
84 /// A pending request has been claimed by a transaction spending the exact same set of outpoints
85 /// as the request. This claim can either be ours or from the counterparty. Once the claiming
86 /// transaction has met [`ANTI_REORG_DELAY`] confirmations, we consider it final and remove the
91 /// The counterparty has claimed an outpoint from one of our pending requests through a
92 /// different transaction than ours. If our transaction was attempting to claim multiple
93 /// outputs, we need to drop the outpoint claimed by the counterparty and regenerate a new claim
94 /// transaction for ourselves. We keep tracking, separately, the outpoint claimed by the
95 /// counterparty up to [`ANTI_REORG_DELAY`] confirmations to ensure we attempt to re-claim it
96 /// if the counterparty's claim is reorged from the chain.
98 package: PackageTemplate,
102 impl Writeable for OnchainEventEntry {
103 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
104 write_tlv_fields!(writer, {
105 (0, self.txid, required),
106 (1, self.block_hash, option),
107 (2, self.height, required),
108 (4, self.event, required),
114 impl MaybeReadable for OnchainEventEntry {
115 fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, DecodeError> {
116 let mut txid = Txid::all_zeros();
118 let mut block_hash = None;
119 let mut event = UpgradableRequired(None);
120 read_tlv_fields!(reader, {
122 (1, block_hash, option),
123 (2, height, required),
124 (4, event, upgradable_required),
126 Ok(Some(Self { txid, height, block_hash, event: _init_tlv_based_struct_field!(event, upgradable_required) }))
130 impl_writeable_tlv_based_enum_upgradable!(OnchainEvent,
132 (0, claim_id, required),
134 (1, ContentiousOutpoint) => {
135 (0, package, required),
139 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
140 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
141 match Readable::read(reader)? {
144 let vlen: u64 = Readable::read(reader)?;
145 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::core::mem::size_of::<Option<(usize, Signature)>>()));
147 ret.push(match Readable::read(reader)? {
149 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
150 _ => return Err(DecodeError::InvalidValue)
155 _ => Err(DecodeError::InvalidValue),
160 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
161 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
165 (vec.len() as u64).write(writer)?;
166 for opt in vec.iter() {
168 &Some((ref idx, ref sig)) => {
170 (*idx as u64).write(writer)?;
173 &None => 0u8.write(writer)?,
177 &None => 0u8.write(writer)?,
184 /// The claim commonly referred to as the pre-signed second-stage HTLC transaction.
185 pub(crate) struct ExternalHTLCClaim {
186 pub(crate) commitment_txid: Txid,
187 pub(crate) per_commitment_number: u64,
188 pub(crate) htlc: HTLCOutputInCommitment,
189 pub(crate) preimage: Option<PaymentPreimage>,
190 pub(crate) counterparty_sig: Signature,
193 // Represents the different types of claims for which events are yielded externally to satisfy said
196 pub(crate) enum ClaimEvent {
197 /// Event yielded to signal that the commitment transaction fee must be bumped to claim any
198 /// encumbered funds and proceed to HTLC resolution, if any HTLCs exist.
200 package_target_feerate_sat_per_1000_weight: u32,
201 commitment_tx: Transaction,
202 anchor_output_idx: u32,
204 /// Event yielded to signal that the commitment transaction has confirmed and its HTLCs must be
205 /// resolved by broadcasting a transaction with sufficient fee to claim them.
207 target_feerate_sat_per_1000_weight: u32,
208 htlcs: Vec<ExternalHTLCClaim>,
209 tx_lock_time: PackedLockTime,
213 /// Represents the different ways an output can be claimed (i.e., spent to an address under our
214 /// control) onchain.
215 pub(crate) enum OnchainClaim {
216 /// A finalized transaction pending confirmation spending the output to claim.
219 /// An event yielded externally to signal additional inputs must be added to a transaction
220 /// pending confirmation spending the output to claim.
224 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
225 /// do RBF bumping if possible.
226 pub struct OnchainTxHandler<ChannelSigner: WriteableEcdsaChannelSigner> {
227 destination_script: Script,
228 holder_commitment: HolderCommitmentTransaction,
229 // holder_htlc_sigs and prev_holder_htlc_sigs are in the order as they appear in the commitment
230 // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
231 // the set of HTLCs in the HolderCommitmentTransaction.
232 holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
233 prev_holder_commitment: Option<HolderCommitmentTransaction>,
234 prev_holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
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
266 pending_claim_events: Vec<(ClaimId, ClaimEvent)>,
268 // Used to link outpoints claimed in a connected block to a pending claim request. The keys
269 // represent the outpoints that our `ChannelMonitor` has detected we have keys/scripts to
270 // claim. The values track the pending claim request identifier and the initial confirmation
271 // block height, and are immutable until the outpoint has enough confirmations to meet our
272 // [`ANTI_REORG_DELAY`]. The initial confirmation block height is used to remove the entry if
273 // the block gets disconnected.
274 #[cfg(test)] // Used in functional_test to verify sanitization
275 pub claimable_outpoints: HashMap<BitcoinOutPoint, (ClaimId, u32)>,
277 claimable_outpoints: HashMap<BitcoinOutPoint, (ClaimId, u32)>,
279 locktimed_packages: BTreeMap<u32, Vec<PackageTemplate>>,
281 onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
283 pub(super) secp_ctx: Secp256k1<secp256k1::All>,
286 impl<ChannelSigner: WriteableEcdsaChannelSigner> PartialEq for OnchainTxHandler<ChannelSigner> {
287 fn eq(&self, other: &Self) -> bool {
288 // `signer`, `secp_ctx`, and `pending_claim_events` are excluded on purpose.
289 self.destination_script == other.destination_script &&
290 self.holder_commitment == other.holder_commitment &&
291 self.holder_htlc_sigs == other.holder_htlc_sigs &&
292 self.prev_holder_commitment == other.prev_holder_commitment &&
293 self.prev_holder_htlc_sigs == other.prev_holder_htlc_sigs &&
294 self.channel_transaction_parameters == other.channel_transaction_parameters &&
295 self.pending_claim_requests == other.pending_claim_requests &&
296 self.claimable_outpoints == other.claimable_outpoints &&
297 self.locktimed_packages == other.locktimed_packages &&
298 self.onchain_events_awaiting_threshold_conf == other.onchain_events_awaiting_threshold_conf
302 const SERIALIZATION_VERSION: u8 = 1;
303 const MIN_SERIALIZATION_VERSION: u8 = 1;
305 impl<ChannelSigner: WriteableEcdsaChannelSigner> OnchainTxHandler<ChannelSigner> {
306 pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
307 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
309 self.destination_script.write(writer)?;
310 self.holder_commitment.write(writer)?;
311 self.holder_htlc_sigs.write(writer)?;
312 self.prev_holder_commitment.write(writer)?;
313 self.prev_holder_htlc_sigs.write(writer)?;
315 self.channel_transaction_parameters.write(writer)?;
317 let mut key_data = VecWriter(Vec::new());
318 self.signer.write(&mut key_data)?;
319 assert!(key_data.0.len() < core::usize::MAX);
320 assert!(key_data.0.len() < core::u32::MAX as usize);
321 (key_data.0.len() as u32).write(writer)?;
322 writer.write_all(&key_data.0[..])?;
324 writer.write_all(&(self.pending_claim_requests.len() as u64).to_be_bytes())?;
325 for (ref ancestor_claim_txid, request) in self.pending_claim_requests.iter() {
326 ancestor_claim_txid.write(writer)?;
327 request.write(writer)?;
330 writer.write_all(&(self.claimable_outpoints.len() as u64).to_be_bytes())?;
331 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
333 claim_and_height.0.write(writer)?;
334 claim_and_height.1.write(writer)?;
337 writer.write_all(&(self.locktimed_packages.len() as u64).to_be_bytes())?;
338 for (ref locktime, ref packages) in self.locktimed_packages.iter() {
339 locktime.write(writer)?;
340 writer.write_all(&(packages.len() as u64).to_be_bytes())?;
341 for ref package in packages.iter() {
342 package.write(writer)?;
346 writer.write_all(&(self.onchain_events_awaiting_threshold_conf.len() as u64).to_be_bytes())?;
347 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
348 entry.write(writer)?;
351 write_tlv_fields!(writer, {});
356 impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP, u64, [u8; 32])> for OnchainTxHandler<SP::Signer> {
357 fn read<R: io::Read>(reader: &mut R, args: (&'a ES, &'b SP, u64, [u8; 32])) -> Result<Self, DecodeError> {
358 let entropy_source = args.0;
359 let signer_provider = args.1;
360 let channel_value_satoshis = args.2;
361 let channel_keys_id = args.3;
363 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
365 let destination_script = Readable::read(reader)?;
367 let holder_commitment = Readable::read(reader)?;
368 let holder_htlc_sigs = Readable::read(reader)?;
369 let prev_holder_commitment = Readable::read(reader)?;
370 let prev_holder_htlc_sigs = Readable::read(reader)?;
372 let channel_parameters = Readable::read(reader)?;
374 // Read the serialized signer bytes, but don't deserialize them, as we'll obtain our signer
375 // by re-deriving the private key material.
376 let keys_len: u32 = Readable::read(reader)?;
377 let mut bytes_read = 0;
378 while bytes_read != keys_len as usize {
379 // Read 1KB at a time to avoid accidentally allocating 4GB on corrupted channel keys
380 let mut data = [0; 1024];
381 let bytes_to_read = cmp::min(1024, keys_len as usize - bytes_read);
382 let read_slice = &mut data[0..bytes_to_read];
383 reader.read_exact(read_slice)?;
384 bytes_read += bytes_to_read;
387 let mut signer = signer_provider.derive_channel_signer(channel_value_satoshis, channel_keys_id);
388 signer.provide_channel_parameters(&channel_parameters);
390 let pending_claim_requests_len: u64 = Readable::read(reader)?;
391 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
392 for _ in 0..pending_claim_requests_len {
393 pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
396 let claimable_outpoints_len: u64 = Readable::read(reader)?;
397 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
398 for _ in 0..claimable_outpoints_len {
399 let outpoint = Readable::read(reader)?;
400 let ancestor_claim_txid = Readable::read(reader)?;
401 let height = Readable::read(reader)?;
402 claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
405 let locktimed_packages_len: u64 = Readable::read(reader)?;
406 let mut locktimed_packages = BTreeMap::new();
407 for _ in 0..locktimed_packages_len {
408 let locktime = Readable::read(reader)?;
409 let packages_len: u64 = Readable::read(reader)?;
410 let mut packages = Vec::with_capacity(cmp::min(packages_len as usize, MAX_ALLOC_SIZE / core::mem::size_of::<PackageTemplate>()));
411 for _ in 0..packages_len {
412 packages.push(Readable::read(reader)?);
414 locktimed_packages.insert(locktime, packages);
417 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
418 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
419 for _ in 0..waiting_threshold_conf_len {
420 if let Some(val) = MaybeReadable::read(reader)? {
421 onchain_events_awaiting_threshold_conf.push(val);
425 read_tlv_fields!(reader, {});
427 let mut secp_ctx = Secp256k1::new();
428 secp_ctx.seeded_randomize(&entropy_source.get_secure_random_bytes());
430 Ok(OnchainTxHandler {
434 prev_holder_commitment,
435 prev_holder_htlc_sigs,
437 channel_transaction_parameters: channel_parameters,
440 pending_claim_requests,
441 onchain_events_awaiting_threshold_conf,
443 pending_claim_events: Vec::new(),
449 impl<ChannelSigner: WriteableEcdsaChannelSigner> OnchainTxHandler<ChannelSigner> {
450 pub(crate) fn new(destination_script: Script, signer: ChannelSigner, channel_parameters: ChannelTransactionParameters, holder_commitment: HolderCommitmentTransaction, secp_ctx: Secp256k1<secp256k1::All>) -> Self {
454 holder_htlc_sigs: None,
455 prev_holder_commitment: None,
456 prev_holder_htlc_sigs: None,
458 channel_transaction_parameters: channel_parameters,
459 pending_claim_requests: HashMap::new(),
460 claimable_outpoints: HashMap::new(),
461 locktimed_packages: BTreeMap::new(),
462 onchain_events_awaiting_threshold_conf: Vec::new(),
464 pending_claim_events: Vec::new(),
469 pub(crate) fn get_prev_holder_commitment_to_self_value(&self) -> Option<u64> {
470 self.prev_holder_commitment.as_ref().map(|commitment| commitment.to_broadcaster_value_sat())
473 pub(crate) fn get_cur_holder_commitment_to_self_value(&self) -> u64 {
474 self.holder_commitment.to_broadcaster_value_sat()
478 pub(crate) fn get_and_clear_pending_claim_events(&mut self) -> Vec<(ClaimId, ClaimEvent)> {
479 let mut events = Vec::new();
480 swap(&mut events, &mut self.pending_claim_events);
484 /// Triggers rebroadcasts/fee-bumps of pending claims from a force-closed channel. This is
485 /// crucial in preventing certain classes of pinning attacks, detecting substantial mempool
486 /// feerate changes between blocks, and ensuring reliability if broadcasting fails. We recommend
487 /// invoking this every 30 seconds, or lower if running in an environment with spotty
488 /// connections, like on mobile.
489 pub(crate) fn rebroadcast_pending_claims<B: Deref, F: Deref, L: Deref>(
490 &mut self, current_height: u32, broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>,
494 B::Target: BroadcasterInterface,
495 F::Target: FeeEstimator,
498 let mut bump_requests = Vec::with_capacity(self.pending_claim_requests.len());
499 for (claim_id, request) in self.pending_claim_requests.iter() {
500 let inputs = request.outpoints();
501 log_info!(logger, "Triggering rebroadcast/fee-bump for request with inputs {:?}", inputs);
502 bump_requests.push((*claim_id, request.clone()));
504 for (claim_id, request) in bump_requests {
505 self.generate_claim(current_height, &request, false /* force_feerate_bump */, fee_estimator, logger)
506 .map(|(_, new_feerate, claim)| {
507 let mut bumped_feerate = false;
508 if let Some(mut_request) = self.pending_claim_requests.get_mut(&claim_id) {
509 bumped_feerate = request.previous_feerate() > new_feerate;
510 mut_request.set_feerate(new_feerate);
513 OnchainClaim::Tx(tx) => {
514 let log_start = if bumped_feerate { "Broadcasting RBF-bumped" } else { "Rebroadcasting" };
515 log_info!(logger, "{} onchain {}", log_start, log_tx!(tx));
516 broadcaster.broadcast_transactions(&[&tx]);
519 OnchainClaim::Event(event) => {
520 let log_start = if bumped_feerate { "Yielding fee-bumped" } else { "Replaying" };
521 log_info!(logger, "{} onchain event to spend inputs {:?}", log_start,
522 request.outpoints());
523 #[cfg(debug_assertions)] {
524 debug_assert!(request.requires_external_funding());
525 let num_existing = self.pending_claim_events.iter()
526 .filter(|entry| entry.0 == claim_id).count();
527 assert!(num_existing == 0 || num_existing == 1);
529 self.pending_claim_events.retain(|event| event.0 != claim_id);
530 self.pending_claim_events.push((claim_id, event));
537 /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize counterparty
538 /// onchain) lays on the assumption of claim transactions getting confirmed before timelock
539 /// expiration (CSV or CLTV following cases). In case of high-fee spikes, claim tx may get stuck
540 /// in the mempool, so you need to bump its feerate quickly using Replace-By-Fee or
541 /// Child-Pay-For-Parent.
543 /// Panics if there are signing errors, because signing operations in reaction to on-chain
544 /// events are not expected to fail, and if they do, we may lose funds.
545 fn generate_claim<F: Deref, L: Deref>(
546 &mut self, cur_height: u32, cached_request: &PackageTemplate, force_feerate_bump: bool,
547 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L,
548 ) -> Option<(u32, u64, OnchainClaim)>
550 F::Target: FeeEstimator,
553 let request_outpoints = cached_request.outpoints();
554 if request_outpoints.is_empty() {
555 // Don't prune pending claiming request yet, we may have to resurrect HTLCs. Untractable
556 // packages cannot be aggregated and will never be split, so we cannot end up with an
558 debug_assert!(cached_request.is_malleable());
561 // If we've seen transaction inclusion in the chain for all outpoints in our request, we
562 // don't need to continue generating more claims. We'll keep tracking the request to fully
563 // remove it once it reaches the confirmation threshold, or to generate a new claim if the
564 // transaction is reorged out.
565 let mut all_inputs_have_confirmed_spend = true;
566 for outpoint in request_outpoints.iter() {
567 if let Some((request_claim_id, _)) = self.claimable_outpoints.get(*outpoint) {
568 // We check for outpoint spends within claims individually rather than as a set
569 // since requests can have outpoints split off.
570 if !self.onchain_events_awaiting_threshold_conf.iter()
571 .any(|event_entry| if let OnchainEvent::Claim { claim_id } = event_entry.event {
572 *request_claim_id == claim_id
574 // The onchain event is not a claim, keep seeking until we find one.
578 // Either we had no `OnchainEvent::Claim`, or we did but none matched the
579 // outpoint's registered spend.
580 all_inputs_have_confirmed_spend = false;
583 // The request's outpoint spend does not exist yet.
584 all_inputs_have_confirmed_spend = false;
587 if all_inputs_have_confirmed_spend {
591 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
592 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
593 let new_timer = cached_request.get_height_timer(cur_height);
594 if cached_request.is_malleable() {
596 { // Attributes are not allowed on if expressions on our current MSRV of 1.41.
597 if cached_request.requires_external_funding() {
598 let target_feerate_sat_per_1000_weight = cached_request.compute_package_feerate(
599 fee_estimator, ConfirmationTarget::HighPriority, force_feerate_bump
601 if let Some(htlcs) = cached_request.construct_malleable_package_with_external_funding(self) {
604 target_feerate_sat_per_1000_weight as u64,
605 OnchainClaim::Event(ClaimEvent::BumpHTLC {
606 target_feerate_sat_per_1000_weight,
608 tx_lock_time: PackedLockTime(cached_request.package_locktime(cur_height)),
617 let predicted_weight = cached_request.package_weight(&self.destination_script);
618 if let Some((output_value, new_feerate)) = cached_request.compute_package_output(
619 predicted_weight, self.destination_script.dust_value().to_sat(),
620 force_feerate_bump, fee_estimator, logger,
622 assert!(new_feerate != 0);
624 let transaction = cached_request.finalize_malleable_package(
625 cur_height, self, output_value, self.destination_script.clone(), logger
627 log_trace!(logger, "...with timer {} and feerate {}", new_timer, new_feerate);
628 assert!(predicted_weight >= transaction.weight());
629 return Some((new_timer, new_feerate, OnchainClaim::Tx(transaction)));
632 // Untractable packages cannot have their fees bumped through Replace-By-Fee. Some
633 // packages may support fee bumping through Child-Pays-For-Parent, indicated by those
634 // which require external funding.
636 let inputs = cached_request.inputs();
638 let mut inputs = cached_request.inputs();
639 debug_assert_eq!(inputs.len(), 1);
640 let tx = match cached_request.finalize_untractable_package(self, logger) {
644 if !cached_request.requires_external_funding() {
645 return Some((new_timer, 0, OnchainClaim::Tx(tx)));
648 return inputs.find_map(|input| match input {
649 // Commitment inputs with anchors support are the only untractable inputs supported
650 // thus far that require external funding.
651 PackageSolvingData::HolderFundingOutput(..) => {
652 debug_assert_eq!(tx.txid(), self.holder_commitment.trust().txid(),
653 "Holder commitment transaction mismatch");
654 // We'll locate an anchor output we can spend within the commitment transaction.
655 let funding_pubkey = &self.channel_transaction_parameters.holder_pubkeys.funding_pubkey;
656 match chan_utils::get_anchor_output(&tx, funding_pubkey) {
657 // An anchor output was found, so we should yield a funding event externally.
659 // TODO: Use a lower confirmation target when both our and the
660 // counterparty's latest commitment don't have any HTLCs present.
661 let conf_target = ConfirmationTarget::HighPriority;
662 let package_target_feerate_sat_per_1000_weight = cached_request
663 .compute_package_feerate(fee_estimator, conf_target, force_feerate_bump);
666 package_target_feerate_sat_per_1000_weight as u64,
667 OnchainClaim::Event(ClaimEvent::BumpCommitment {
668 package_target_feerate_sat_per_1000_weight,
669 commitment_tx: tx.clone(),
670 anchor_output_idx: idx,
674 // An anchor output was not found. There's nothing we can do other than
675 // attempt to broadcast the transaction with its current fee rate and hope
676 // it confirms. This is essentially the same behavior as a commitment
677 // transaction without anchor outputs.
678 None => Some((new_timer, 0, OnchainClaim::Tx(tx.clone()))),
682 debug_assert!(false, "Only HolderFundingOutput inputs should be untractable and require external funding");
690 /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
691 /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
692 /// Together with `update_claims_view_from_matched_txn` this used to be named
693 /// `block_connected`, but it is now also used for claiming an HTLC output if we receive a
694 /// preimage after force-close.
696 /// `conf_height` represents the height at which the request was generated. This
697 /// does not need to equal the current blockchain tip height, which should be provided via
698 /// `cur_height`, however it must never be higher than `cur_height`.
699 pub(crate) fn update_claims_view_from_requests<B: Deref, F: Deref, L: Deref>(
700 &mut self, requests: Vec<PackageTemplate>, conf_height: u32, cur_height: u32,
701 broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L
703 B::Target: BroadcasterInterface,
704 F::Target: FeeEstimator,
707 log_debug!(logger, "Updating claims view at height {} with {} claim requests", cur_height, requests.len());
708 let mut preprocessed_requests = Vec::with_capacity(requests.len());
709 let mut aggregated_request = None;
711 // Try to aggregate outputs if their timelock expiration isn't imminent (package timelock
712 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
713 for req in requests {
714 // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
715 if let Some(_) = self.claimable_outpoints.get(req.outpoints()[0]) {
716 log_info!(logger, "Ignoring second claim for outpoint {}:{}, already registered its claiming request", req.outpoints()[0].txid, req.outpoints()[0].vout);
718 let timelocked_equivalent_package = self.locktimed_packages.iter().map(|v| v.1.iter()).flatten()
719 .find(|locked_package| locked_package.outpoints() == req.outpoints());
720 if let Some(package) = timelocked_equivalent_package {
721 log_info!(logger, "Ignoring second claim for outpoint {}:{}, we already have one which we're waiting on a timelock at {} for.",
722 req.outpoints()[0].txid, req.outpoints()[0].vout, package.package_locktime(cur_height));
726 let package_locktime = req.package_locktime(cur_height);
727 if package_locktime > cur_height + 1 {
728 log_info!(logger, "Delaying claim of package until its timelock at {} (current height {}), the following outpoints are spent:", package_locktime, cur_height);
729 for outpoint in req.outpoints() {
730 log_info!(logger, " Outpoint {}", outpoint);
732 self.locktimed_packages.entry(package_locktime).or_insert(Vec::new()).push(req);
736 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.timelock(), cur_height + CLTV_SHARED_CLAIM_BUFFER);
737 if req.timelock() <= cur_height + CLTV_SHARED_CLAIM_BUFFER || !req.aggregable() {
738 // Don't aggregate if outpoint package timelock is soon or marked as non-aggregable
739 preprocessed_requests.push(req);
740 } else if aggregated_request.is_none() {
741 aggregated_request = Some(req);
743 aggregated_request.as_mut().unwrap().merge_package(req);
747 if let Some(req) = aggregated_request {
748 preprocessed_requests.push(req);
751 // Claim everything up to and including `cur_height`
752 let remaining_locked_packages = self.locktimed_packages.split_off(&(cur_height + 1));
753 for (pop_height, mut entry) in self.locktimed_packages.iter_mut() {
754 log_trace!(logger, "Restoring delayed claim of package(s) at their timelock at {}.", pop_height);
755 preprocessed_requests.append(&mut entry);
757 self.locktimed_packages = remaining_locked_packages;
759 // Generate claim transactions and track them to bump if necessary at
760 // height timer expiration (i.e in how many blocks we're going to take action).
761 for mut req in preprocessed_requests {
762 if let Some((new_timer, new_feerate, claim)) = self.generate_claim(
763 cur_height, &req, true /* force_feerate_bump */, &*fee_estimator, &*logger,
765 req.set_timer(new_timer);
766 req.set_feerate(new_feerate);
767 let claim_id = match claim {
768 OnchainClaim::Tx(tx) => {
769 log_info!(logger, "Broadcasting onchain {}", log_tx!(tx));
770 broadcaster.broadcast_transactions(&[&tx]);
771 ClaimId(tx.txid().into_inner())
774 OnchainClaim::Event(claim_event) => {
775 log_info!(logger, "Yielding onchain event to spend inputs {:?}", req.outpoints());
776 let claim_id = match claim_event {
777 ClaimEvent::BumpCommitment { ref commitment_tx, .. } =>
778 // For commitment claims, we can just use their txid as it should
779 // already be unique.
780 ClaimId(commitment_tx.txid().into_inner()),
781 ClaimEvent::BumpHTLC { ref htlcs, .. } => {
782 // For HTLC claims, commit to the entire set of HTLC outputs to
783 // claim, which will always be unique per request. Once a claim ID
784 // is generated, it is assigned and remains unchanged, even if the
785 // underlying set of HTLCs changes.
786 let mut engine = Sha256::engine();
788 engine.input(&htlc.commitment_txid.into_inner());
789 engine.input(&htlc.htlc.transaction_output_index.unwrap().to_be_bytes());
791 ClaimId(Sha256::from_engine(engine).into_inner())
794 debug_assert!(self.pending_claim_requests.get(&claim_id).is_none());
795 debug_assert_eq!(self.pending_claim_events.iter().filter(|entry| entry.0 == claim_id).count(), 0);
796 self.pending_claim_events.push((claim_id, claim_event));
800 debug_assert!(self.pending_claim_requests.get(&claim_id).is_none());
801 for k in req.outpoints() {
802 log_info!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
803 self.claimable_outpoints.insert(k.clone(), (claim_id, conf_height));
805 self.pending_claim_requests.insert(claim_id, req);
810 /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
811 /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
812 /// Together with `update_claims_view_from_requests` this used to be named `block_connected`,
813 /// but it is now also used for claiming an HTLC output if we receive a preimage after force-close.
815 /// `conf_height` represents the height at which the transactions in `txn_matched` were
816 /// confirmed. This does not need to equal the current blockchain tip height, which should be
817 /// provided via `cur_height`, however it must never be higher than `cur_height`.
818 pub(crate) fn update_claims_view_from_matched_txn<B: Deref, F: Deref, L: Deref>(
819 &mut self, txn_matched: &[&Transaction], conf_height: u32, conf_hash: BlockHash,
820 cur_height: u32, broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L
822 B::Target: BroadcasterInterface,
823 F::Target: FeeEstimator,
826 log_debug!(logger, "Updating claims view at height {} with {} matched transactions in block {}", cur_height, txn_matched.len(), conf_height);
827 let mut bump_candidates = HashMap::new();
828 for tx in txn_matched {
829 // Scan all input to verify is one of the outpoint spent is of interest for us
830 let mut claimed_outputs_material = Vec::new();
831 for inp in &tx.input {
832 if let Some((claim_id, _)) = self.claimable_outpoints.get(&inp.previous_output) {
833 // If outpoint has claim request pending on it...
834 if let Some(request) = self.pending_claim_requests.get_mut(claim_id) {
835 //... we need to verify equality between transaction outpoints and claim request
836 // outpoints to know if transaction is the original claim or a bumped one issued
838 let mut are_sets_equal = true;
839 let mut tx_inputs = tx.input.iter().map(|input| &input.previous_output).collect::<Vec<_>>();
840 tx_inputs.sort_unstable();
841 for request_input in request.outpoints() {
842 if tx_inputs.binary_search(&request_input).is_err() {
843 are_sets_equal = false;
848 macro_rules! clean_claim_request_after_safety_delay {
850 let entry = OnchainEventEntry {
853 block_hash: Some(conf_hash),
854 event: OnchainEvent::Claim { claim_id: *claim_id }
856 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
857 self.onchain_events_awaiting_threshold_conf.push(entry);
862 // If this is our transaction (or our counterparty spent all the outputs
863 // before we could anyway with same inputs order than us), wait for
864 // ANTI_REORG_DELAY and clean the RBF tracking map.
866 clean_claim_request_after_safety_delay!();
867 } else { // If false, generate new claim request with update outpoint set
868 let mut at_least_one_drop = false;
869 for input in tx.input.iter() {
870 if let Some(package) = request.split_package(&input.previous_output) {
871 claimed_outputs_material.push(package);
872 at_least_one_drop = true;
874 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
875 if request.outpoints().is_empty() {
876 clean_claim_request_after_safety_delay!();
879 //TODO: recompute soonest_timelock to avoid wasting a bit on fees
880 if at_least_one_drop {
881 bump_candidates.insert(*claim_id, request.clone());
882 // If we have any pending claim events for the request being updated
883 // that have yet to be consumed, we'll remove them since they will
884 // end up producing an invalid transaction by double spending
885 // input(s) that already have a confirmed spend. If such spend is
886 // reorged out of the chain, then we'll attempt to re-spend the
887 // inputs once we see it.
889 #[cfg(debug_assertions)] {
890 let existing = self.pending_claim_events.iter()
891 .filter(|entry| entry.0 == *claim_id).count();
892 assert!(existing == 0 || existing == 1);
894 self.pending_claim_events.retain(|entry| entry.0 != *claim_id);
898 break; //No need to iterate further, either tx is our or their
900 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
904 for package in claimed_outputs_material.drain(..) {
905 let entry = OnchainEventEntry {
908 block_hash: Some(conf_hash),
909 event: OnchainEvent::ContentiousOutpoint { package },
911 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
912 self.onchain_events_awaiting_threshold_conf.push(entry);
917 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
918 let onchain_events_awaiting_threshold_conf =
919 self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
920 for entry in onchain_events_awaiting_threshold_conf {
921 if entry.has_reached_confirmation_threshold(cur_height) {
923 OnchainEvent::Claim { claim_id } => {
924 // We may remove a whole set of claim outpoints here, as these one may have
925 // been aggregated in a single tx and claimed so atomically
926 if let Some(request) = self.pending_claim_requests.remove(&claim_id) {
927 for outpoint in request.outpoints() {
928 log_debug!(logger, "Removing claim tracking for {} due to maturation of claim package {}.",
929 outpoint, log_bytes!(claim_id.0));
930 self.claimable_outpoints.remove(outpoint);
933 #[cfg(debug_assertions)] {
934 let num_existing = self.pending_claim_events.iter()
935 .filter(|entry| entry.0 == claim_id).count();
936 assert!(num_existing == 0 || num_existing == 1);
938 self.pending_claim_events.retain(|(id, _)| *id != claim_id);
942 OnchainEvent::ContentiousOutpoint { package } => {
943 log_debug!(logger, "Removing claim tracking due to maturation of claim tx for outpoints:");
944 log_debug!(logger, " {:?}", package.outpoints());
945 self.claimable_outpoints.remove(package.outpoints()[0]);
949 self.onchain_events_awaiting_threshold_conf.push(entry);
953 // Check if any pending claim request must be rescheduled
954 for (claim_id, request) in self.pending_claim_requests.iter() {
955 if cur_height >= request.timer() {
956 bump_candidates.insert(*claim_id, request.clone());
960 // Build, bump and rebroadcast tx accordingly
961 log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
962 for (claim_id, request) in bump_candidates.iter() {
963 if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(
964 cur_height, &request, true /* force_feerate_bump */, &*fee_estimator, &*logger,
967 OnchainClaim::Tx(bump_tx) => {
968 log_info!(logger, "Broadcasting RBF-bumped onchain {}", log_tx!(bump_tx));
969 broadcaster.broadcast_transactions(&[&bump_tx]);
972 OnchainClaim::Event(claim_event) => {
973 log_info!(logger, "Yielding RBF-bumped onchain event to spend inputs {:?}", request.outpoints());
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(|event| event.0 != *claim_id);
980 self.pending_claim_events.push((*claim_id, claim_event));
983 if let Some(request) = self.pending_claim_requests.get_mut(claim_id) {
984 request.set_timer(new_timer);
985 request.set_feerate(new_feerate);
991 pub(crate) fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
995 fee_estimator: &LowerBoundedFeeEstimator<F>,
998 B::Target: BroadcasterInterface,
999 F::Target: FeeEstimator,
1002 let mut height = None;
1003 for entry in self.onchain_events_awaiting_threshold_conf.iter() {
1004 if entry.txid == *txid {
1005 height = Some(entry.height);
1010 if let Some(height) = height {
1011 self.block_disconnected(height, broadcaster, fee_estimator, logger);
1015 pub(crate) fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: L)
1016 where B::Target: BroadcasterInterface,
1017 F::Target: FeeEstimator,
1020 let mut bump_candidates = HashMap::new();
1021 let onchain_events_awaiting_threshold_conf =
1022 self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
1023 for entry in onchain_events_awaiting_threshold_conf {
1024 if entry.height >= height {
1025 //- our claim tx on a commitment tx output
1026 //- resurect outpoint back in its claimable set and regenerate tx
1028 OnchainEvent::ContentiousOutpoint { package } => {
1029 if let Some(pending_claim) = self.claimable_outpoints.get(package.outpoints()[0]) {
1030 if let Some(request) = self.pending_claim_requests.get_mut(&pending_claim.0) {
1031 request.merge_package(package);
1032 // Using a HashMap guarantee us than if we have multiple outpoints getting
1033 // resurrected only one bump claim tx is going to be broadcast
1034 bump_candidates.insert(pending_claim.clone(), request.clone());
1041 self.onchain_events_awaiting_threshold_conf.push(entry);
1044 for ((_claim_id, _), ref mut request) in bump_candidates.iter_mut() {
1045 // `height` is the height being disconnected, so our `current_height` is 1 lower.
1046 let current_height = height - 1;
1047 if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(
1048 current_height, &request, true /* force_feerate_bump */, fee_estimator, &&*logger
1050 request.set_timer(new_timer);
1051 request.set_feerate(new_feerate);
1053 OnchainClaim::Tx(bump_tx) => {
1054 log_info!(logger, "Broadcasting onchain {}", log_tx!(bump_tx));
1055 broadcaster.broadcast_transactions(&[&bump_tx]);
1058 OnchainClaim::Event(claim_event) => {
1059 log_info!(logger, "Yielding onchain event after reorg to spend inputs {:?}", request.outpoints());
1060 #[cfg(debug_assertions)] {
1061 let num_existing = self.pending_claim_events.iter()
1062 .filter(|entry| entry.0 == *_claim_id).count();
1063 assert!(num_existing == 0 || num_existing == 1);
1065 self.pending_claim_events.retain(|event| event.0 != *_claim_id);
1066 self.pending_claim_events.push((*_claim_id, claim_event));
1071 for (ancestor_claim_txid, request) in bump_candidates.drain() {
1072 self.pending_claim_requests.insert(ancestor_claim_txid.0, request);
1074 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
1075 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
1076 let mut remove_request = Vec::new();
1077 self.claimable_outpoints.retain(|_, ref v|
1079 remove_request.push(v.0.clone());
1082 for req in remove_request {
1083 self.pending_claim_requests.remove(&req);
1087 pub(crate) fn is_output_spend_pending(&self, outpoint: &BitcoinOutPoint) -> bool {
1088 self.claimable_outpoints.get(outpoint).is_some()
1091 pub(crate) fn get_relevant_txids(&self) -> Vec<(Txid, Option<BlockHash>)> {
1092 let mut txids: Vec<(Txid, Option<BlockHash>)> = self.onchain_events_awaiting_threshold_conf
1094 .map(|entry| (entry.txid, entry.block_hash))
1096 txids.sort_unstable_by_key(|(txid, _)| *txid);
1101 pub(crate) fn provide_latest_holder_tx(&mut self, tx: HolderCommitmentTransaction) {
1102 self.prev_holder_commitment = Some(replace(&mut self.holder_commitment, tx));
1103 self.holder_htlc_sigs = None;
1106 // Normally holder HTLCs are signed at the same time as the holder commitment tx. However,
1107 // in some configurations, the holder commitment tx has been signed and broadcast by a
1108 // ChannelMonitor replica, so we handle that case here.
1109 fn sign_latest_holder_htlcs(&mut self) {
1110 if self.holder_htlc_sigs.is_none() {
1111 let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
1112 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, sigs));
1116 // Normally only the latest commitment tx and HTLCs need to be signed. However, in some
1117 // configurations we may have updated our holder commitment but a replica of the ChannelMonitor
1118 // broadcast the previous one before we sync with it. We handle that case here.
1119 fn sign_prev_holder_htlcs(&mut self) {
1120 if self.prev_holder_htlc_sigs.is_none() {
1121 if let Some(ref holder_commitment) = self.prev_holder_commitment {
1122 let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(holder_commitment, &self.secp_ctx).expect("sign previous holder commitment");
1123 self.prev_holder_htlc_sigs = Some(Self::extract_holder_sigs(holder_commitment, sigs));
1128 fn extract_holder_sigs(holder_commitment: &HolderCommitmentTransaction, sigs: Vec<Signature>) -> Vec<Option<(usize, Signature)>> {
1129 let mut ret = Vec::new();
1130 for (htlc_idx, (holder_sig, htlc)) in sigs.iter().zip(holder_commitment.htlcs().iter()).enumerate() {
1131 let tx_idx = htlc.transaction_output_index.unwrap();
1132 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
1133 ret[tx_idx as usize] = Some((htlc_idx, holder_sig.clone()));
1138 //TODO: getting lastest holder transactions should be infallible and result in us "force-closing the channel", but we may
1139 // have empty holder commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
1140 // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
1141 // to monitor before.
1142 pub(crate) fn get_fully_signed_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
1143 let (sig, htlc_sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("signing holder commitment");
1144 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
1145 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
1148 #[cfg(any(test, feature="unsafe_revoked_tx_signing"))]
1149 pub(crate) fn get_fully_signed_copy_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
1150 let (sig, htlc_sigs) = self.signer.unsafe_sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
1151 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
1152 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
1155 pub(crate) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
1156 let mut htlc_tx = None;
1157 let commitment_txid = self.holder_commitment.trust().txid();
1158 // Check if the HTLC spends from the current holder commitment
1159 if commitment_txid == outp.txid {
1160 self.sign_latest_holder_htlcs();
1161 if let &Some(ref htlc_sigs) = &self.holder_htlc_sigs {
1162 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
1163 let trusted_tx = self.holder_commitment.trust();
1164 let counterparty_htlc_sig = self.holder_commitment.counterparty_htlc_sigs[*htlc_idx];
1165 htlc_tx = Some(trusted_tx
1166 .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
1169 // If the HTLC doesn't spend the current holder commitment, check if it spends the previous one
1170 if htlc_tx.is_none() && self.prev_holder_commitment.is_some() {
1171 let commitment_txid = self.prev_holder_commitment.as_ref().unwrap().trust().txid();
1172 if commitment_txid == outp.txid {
1173 self.sign_prev_holder_htlcs();
1174 if let &Some(ref htlc_sigs) = &self.prev_holder_htlc_sigs {
1175 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
1176 let holder_commitment = self.prev_holder_commitment.as_ref().unwrap();
1177 let trusted_tx = holder_commitment.trust();
1178 let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[*htlc_idx];
1179 htlc_tx = Some(trusted_tx
1180 .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
1188 pub(crate) fn generate_external_htlc_claim(
1189 &self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>
1190 ) -> Option<ExternalHTLCClaim> {
1191 let find_htlc = |holder_commitment: &HolderCommitmentTransaction| -> Option<ExternalHTLCClaim> {
1192 let trusted_tx = holder_commitment.trust();
1193 if outp.txid != trusted_tx.txid() {
1196 trusted_tx.htlcs().iter().enumerate()
1197 .find(|(_, htlc)| if let Some(output_index) = htlc.transaction_output_index {
1198 output_index == outp.vout
1202 .map(|(htlc_idx, htlc)| {
1203 let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[htlc_idx];
1205 commitment_txid: trusted_tx.txid(),
1206 per_commitment_number: trusted_tx.commitment_number(),
1208 preimage: *preimage,
1209 counterparty_sig: counterparty_htlc_sig,
1213 // Check if the HTLC spends from the current holder commitment or the previous one otherwise.
1214 find_htlc(&self.holder_commitment)
1215 .or_else(|| self.prev_holder_commitment.as_ref().map(|c| find_htlc(c)).flatten())
1218 pub(crate) fn opt_anchors(&self) -> bool {
1219 self.channel_transaction_parameters.opt_anchors.is_some()
1222 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
1223 pub(crate) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
1224 let latest_had_sigs = self.holder_htlc_sigs.is_some();
1225 let prev_had_sigs = self.prev_holder_htlc_sigs.is_some();
1226 let ret = self.get_fully_signed_htlc_tx(outp, preimage);
1227 if !latest_had_sigs {
1228 self.holder_htlc_sigs = None;
1231 self.prev_holder_htlc_sigs = None;