1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
10 //! The logic to build claims and bump in-flight transactions until confirmations.
12 //! OnchainTxHandler objects are fully-part of ChannelMonitor and encapsulates all
13 //! building, tracking, bumping and notifications functions.
15 use bitcoin::blockdata::transaction::Transaction;
16 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
17 use bitcoin::blockdata::script::Script;
19 use bitcoin::hash_types::Txid;
21 use bitcoin::secp256k1::{Secp256k1, Signature};
22 use bitcoin::secp256k1;
24 use ln::msgs::DecodeError;
25 use ln::PaymentPreimage;
26 use ln::chan_utils::{ChannelTransactionParameters, HolderCommitmentTransaction};
27 use chain::chaininterface::{FeeEstimator, BroadcasterInterface};
28 use chain::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER};
29 use chain::keysinterface::{Sign, KeysInterface};
30 use chain::package::PackageTemplate;
31 use util::logger::Logger;
32 use util::ser::{Readable, ReadableArgs, Writer, Writeable, VecWriter};
36 use alloc::collections::BTreeMap;
39 use core::mem::replace;
41 const MAX_ALLOC_SIZE: usize = 64*1024;
43 /// An entry for an [`OnchainEvent`], stating the block height when the event was observed and the
44 /// transaction causing it.
46 /// Used to determine when the on-chain event can be considered safe from a chain reorganization.
48 struct OnchainEventEntry {
54 impl OnchainEventEntry {
55 fn confirmation_threshold(&self) -> u32 {
56 self.height + ANTI_REORG_DELAY - 1
59 fn has_reached_confirmation_threshold(&self, height: u32) -> bool {
60 height >= self.confirmation_threshold()
64 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
65 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
68 /// Outpoint under claim process by our own tx, once this one get enough confirmations, we remove it from
69 /// bump-txn candidate buffer.
73 /// Claim tx aggregate multiple claimable outpoints. One of the outpoint may be claimed by a counterparty party tx.
74 /// In this case, we need to drop the outpoint and regenerate a new claim tx. By safety, we keep tracking
75 /// the outpoint to be sure to resurect it back to the claim tx if reorgs happen.
77 package: PackageTemplate,
81 impl_writeable_tlv_based!(OnchainEventEntry, {
83 (2, height, required),
87 impl_writeable_tlv_based_enum!(OnchainEvent,
89 (0, claim_request, required),
91 (1, ContentiousOutpoint) => {
92 (0, package, required),
96 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
97 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
98 match Readable::read(reader)? {
101 let vlen: u64 = Readable::read(reader)?;
102 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::core::mem::size_of::<Option<(usize, Signature)>>()));
104 ret.push(match Readable::read(reader)? {
106 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
107 _ => return Err(DecodeError::InvalidValue)
112 _ => Err(DecodeError::InvalidValue),
117 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
118 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
122 (vec.len() as u64).write(writer)?;
123 for opt in vec.iter() {
125 &Some((ref idx, ref sig)) => {
127 (*idx as u64).write(writer)?;
130 &None => 0u8.write(writer)?,
134 &None => 0u8.write(writer)?,
141 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
142 /// do RBF bumping if possible.
143 pub struct OnchainTxHandler<ChannelSigner: Sign> {
144 destination_script: Script,
145 holder_commitment: HolderCommitmentTransaction,
146 // holder_htlc_sigs and prev_holder_htlc_sigs are in the order as they appear in the commitment
147 // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
148 // the set of HTLCs in the HolderCommitmentTransaction.
149 holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
150 prev_holder_commitment: Option<HolderCommitmentTransaction>,
151 prev_holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
153 pub(super) signer: ChannelSigner,
154 pub(crate) channel_transaction_parameters: ChannelTransactionParameters,
156 // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
157 // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
158 // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
159 // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
160 // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
161 // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
162 // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
163 // we need to regenerate new claim request with reduced set of still-claimable outpoints.
164 // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
165 // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
166 // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
167 #[cfg(test)] // Used in functional_test to verify sanitization
168 pub(crate) pending_claim_requests: HashMap<Txid, PackageTemplate>,
170 pending_claim_requests: HashMap<Txid, PackageTemplate>,
172 // Used to link outpoints claimed in a connected block to a pending claim request.
173 // Key is outpoint than monitor parsing has detected we have keys/scripts to claim
174 // Value is (pending claim request identifier, confirmation_block), identifier
175 // is txid of the initial claiming transaction and is immutable until outpoint is
176 // post-anti-reorg-delay solved, confirmaiton_block is used to erase entry if
177 // block with output gets disconnected.
178 #[cfg(test)] // Used in functional_test to verify sanitization
179 pub claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
181 claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
183 locktimed_packages: BTreeMap<u32, Vec<PackageTemplate>>,
185 onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
187 pub(super) secp_ctx: Secp256k1<secp256k1::All>,
190 const SERIALIZATION_VERSION: u8 = 1;
191 const MIN_SERIALIZATION_VERSION: u8 = 1;
193 impl<ChannelSigner: Sign> OnchainTxHandler<ChannelSigner> {
194 pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
195 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
197 self.destination_script.write(writer)?;
198 self.holder_commitment.write(writer)?;
199 self.holder_htlc_sigs.write(writer)?;
200 self.prev_holder_commitment.write(writer)?;
201 self.prev_holder_htlc_sigs.write(writer)?;
203 self.channel_transaction_parameters.write(writer)?;
205 let mut key_data = VecWriter(Vec::new());
206 self.signer.write(&mut key_data)?;
207 assert!(key_data.0.len() < core::usize::MAX);
208 assert!(key_data.0.len() < core::u32::MAX as usize);
209 (key_data.0.len() as u32).write(writer)?;
210 writer.write_all(&key_data.0[..])?;
212 writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
213 for (ref ancestor_claim_txid, request) in self.pending_claim_requests.iter() {
214 ancestor_claim_txid.write(writer)?;
215 request.write(writer)?;
218 writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
219 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
221 claim_and_height.0.write(writer)?;
222 claim_and_height.1.write(writer)?;
225 writer.write_all(&byte_utils::be64_to_array(self.locktimed_packages.len() as u64))?;
226 for (ref locktime, ref packages) in self.locktimed_packages.iter() {
227 locktime.write(writer)?;
228 writer.write_all(&byte_utils::be64_to_array(packages.len() as u64))?;
229 for ref package in packages.iter() {
230 package.write(writer)?;
234 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_awaiting_threshold_conf.len() as u64))?;
235 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
236 entry.write(writer)?;
239 write_tlv_fields!(writer, {});
244 impl<'a, K: KeysInterface> ReadableArgs<&'a K> for OnchainTxHandler<K::Signer> {
245 fn read<R: ::std::io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
246 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
248 let destination_script = Readable::read(reader)?;
250 let holder_commitment = Readable::read(reader)?;
251 let holder_htlc_sigs = Readable::read(reader)?;
252 let prev_holder_commitment = Readable::read(reader)?;
253 let prev_holder_htlc_sigs = Readable::read(reader)?;
255 let channel_parameters = Readable::read(reader)?;
257 let keys_len: u32 = Readable::read(reader)?;
258 let mut keys_data = Vec::with_capacity(cmp::min(keys_len as usize, MAX_ALLOC_SIZE));
259 while keys_data.len() != keys_len as usize {
260 // Read 1KB at a time to avoid accidentally allocating 4GB on corrupted channel keys
261 let mut data = [0; 1024];
262 let read_slice = &mut data[0..cmp::min(1024, keys_len as usize - keys_data.len())];
263 reader.read_exact(read_slice)?;
264 keys_data.extend_from_slice(read_slice);
266 let signer = keys_manager.read_chan_signer(&keys_data)?;
268 let pending_claim_requests_len: u64 = Readable::read(reader)?;
269 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
270 for _ in 0..pending_claim_requests_len {
271 pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
274 let claimable_outpoints_len: u64 = Readable::read(reader)?;
275 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
276 for _ in 0..claimable_outpoints_len {
277 let outpoint = Readable::read(reader)?;
278 let ancestor_claim_txid = Readable::read(reader)?;
279 let height = Readable::read(reader)?;
280 claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
283 let locktimed_packages_len: u64 = Readable::read(reader)?;
284 let mut locktimed_packages = BTreeMap::new();
285 for _ in 0..locktimed_packages_len {
286 let locktime = Readable::read(reader)?;
287 let packages_len: u64 = Readable::read(reader)?;
288 let mut packages = Vec::with_capacity(cmp::min(packages_len as usize, MAX_ALLOC_SIZE / std::mem::size_of::<PackageTemplate>()));
289 for _ in 0..packages_len {
290 packages.push(Readable::read(reader)?);
292 locktimed_packages.insert(locktime, packages);
295 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
296 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
297 for _ in 0..waiting_threshold_conf_len {
298 onchain_events_awaiting_threshold_conf.push(Readable::read(reader)?);
301 read_tlv_fields!(reader, {});
303 let mut secp_ctx = Secp256k1::new();
304 secp_ctx.seeded_randomize(&keys_manager.get_secure_random_bytes());
306 Ok(OnchainTxHandler {
310 prev_holder_commitment,
311 prev_holder_htlc_sigs,
313 channel_transaction_parameters: channel_parameters,
316 pending_claim_requests,
317 onchain_events_awaiting_threshold_conf,
323 impl<ChannelSigner: Sign> OnchainTxHandler<ChannelSigner> {
324 pub(crate) fn new(destination_script: Script, signer: ChannelSigner, channel_parameters: ChannelTransactionParameters, holder_commitment: HolderCommitmentTransaction, secp_ctx: Secp256k1<secp256k1::All>) -> Self {
328 holder_htlc_sigs: None,
329 prev_holder_commitment: None,
330 prev_holder_htlc_sigs: None,
332 channel_transaction_parameters: channel_parameters,
333 pending_claim_requests: HashMap::new(),
334 claimable_outpoints: HashMap::new(),
335 locktimed_packages: BTreeMap::new(),
336 onchain_events_awaiting_threshold_conf: Vec::new(),
342 /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize coutnerparty onchain) lays on the assumption of claim transactions getting confirmed before timelock expiration
343 /// (CSV or CLTV following cases). In case of high-fee spikes, claim tx may stuck in the mempool, so you need to bump its feerate quickly using Replace-By-Fee or Child-Pay-For-Parent.
344 /// Panics if there are signing errors, because signing operations in reaction to on-chain events
345 /// are not expected to fail, and if they do, we may lose funds.
346 fn generate_claim_tx<F: Deref, L: Deref>(&mut self, height: u32, cached_request: &PackageTemplate, fee_estimator: &F, logger: &L) -> Option<(Option<u32>, u64, Transaction)>
347 where F::Target: FeeEstimator,
350 if cached_request.outpoints().len() == 0 { return None } // But don't prune pending claiming request yet, we may have to resurrect HTLCs
352 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
353 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
354 let new_timer = Some(cached_request.get_height_timer(height));
355 if cached_request.is_malleable() {
356 let predicted_weight = cached_request.package_weight(&self.destination_script);
357 if let Some((output_value, new_feerate)) = cached_request.compute_package_output(predicted_weight, fee_estimator, logger) {
358 assert!(new_feerate != 0);
360 let transaction = cached_request.finalize_package(self, output_value, self.destination_script.clone(), logger).unwrap();
361 log_trace!(logger, "...with timer {} and feerate {}", new_timer.unwrap(), new_feerate);
362 assert!(predicted_weight >= transaction.get_weight());
363 return Some((new_timer, new_feerate, transaction))
366 // Note: Currently, amounts of holder outputs spending witnesses aren't used
367 // as we can't malleate spending package to increase their feerate. This
368 // should change with the remaining anchor output patchset.
369 if let Some(transaction) = cached_request.finalize_package(self, 0, self.destination_script.clone(), logger) {
370 return Some((None, 0, transaction));
376 /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
377 /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
378 /// Formerly this was named `block_connected`, but it is now also used for claiming an HTLC output
379 /// if we receive a preimage after force-close.
380 pub(crate) fn update_claims_view<B: Deref, F: Deref, L: Deref>(&mut self, txn_matched: &[&Transaction], requests: Vec<PackageTemplate>, height: u32, broadcaster: &B, fee_estimator: &F, logger: &L)
381 where B::Target: BroadcasterInterface,
382 F::Target: FeeEstimator,
385 log_debug!(logger, "Updating claims view at height {} with {} matched transactions and {} claim requests", height, txn_matched.len(), requests.len());
386 let mut preprocessed_requests = Vec::with_capacity(requests.len());
387 let mut aggregated_request = None;
389 // Try to aggregate outputs if their timelock expiration isn't imminent (package timelock
390 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
391 for req in requests {
392 // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
393 if let Some(_) = self.claimable_outpoints.get(req.outpoints()[0]) {
394 log_info!(logger, "Ignoring second claim for outpoint {}:{}, already registered its claiming request", req.outpoints()[0].txid, req.outpoints()[0].vout);
396 let timelocked_equivalent_package = self.locktimed_packages.iter().map(|v| v.1.iter()).flatten()
397 .find(|locked_package| locked_package.outpoints() == req.outpoints());
398 if let Some(package) = timelocked_equivalent_package {
399 log_info!(logger, "Ignoring second claim for outpoint {}:{}, we already have one which we're waiting on a timelock at {} for.",
400 req.outpoints()[0].txid, req.outpoints()[0].vout, package.package_timelock());
404 if req.package_timelock() > height + 1 {
405 log_info!(logger, "Delaying claim of package until its timelock at {} (current height {}), the following outpoints are spent:", req.package_timelock(), height);
406 for outpoint in req.outpoints() {
407 log_info!(logger, " Outpoint {}", outpoint);
409 self.locktimed_packages.entry(req.package_timelock()).or_insert(Vec::new()).push(req);
413 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.timelock(), height + CLTV_SHARED_CLAIM_BUFFER);
414 if req.timelock() <= height + CLTV_SHARED_CLAIM_BUFFER || !req.aggregable() {
415 // Don't aggregate if outpoint package timelock is soon or marked as non-aggregable
416 preprocessed_requests.push(req);
417 } else if aggregated_request.is_none() {
418 aggregated_request = Some(req);
420 aggregated_request.as_mut().unwrap().merge_package(req);
424 if let Some(req) = aggregated_request {
425 preprocessed_requests.push(req);
428 // Claim everything up to and including height + 1
429 let remaining_locked_packages = self.locktimed_packages.split_off(&(height + 2));
430 for (pop_height, mut entry) in self.locktimed_packages.iter_mut() {
431 log_trace!(logger, "Restoring delayed claim of package(s) at their timelock at {}.", pop_height);
432 preprocessed_requests.append(&mut entry);
434 self.locktimed_packages = remaining_locked_packages;
436 // Generate claim transactions and track them to bump if necessary at
437 // height timer expiration (i.e in how many blocks we're going to take action).
438 for mut req in preprocessed_requests {
439 if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(height, &req, &*fee_estimator, &*logger) {
440 req.set_timer(new_timer);
441 req.set_feerate(new_feerate);
442 let txid = tx.txid();
443 for k in req.outpoints() {
444 log_info!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
445 self.claimable_outpoints.insert(k.clone(), (txid, height));
447 self.pending_claim_requests.insert(txid, req);
448 log_info!(logger, "Broadcasting onchain {}", log_tx!(tx));
449 broadcaster.broadcast_transaction(&tx);
453 let mut bump_candidates = HashMap::new();
454 for tx in txn_matched {
455 // Scan all input to verify is one of the outpoint spent is of interest for us
456 let mut claimed_outputs_material = Vec::new();
457 for inp in &tx.input {
458 if let Some(first_claim_txid_height) = self.claimable_outpoints.get(&inp.previous_output) {
459 // If outpoint has claim request pending on it...
460 if let Some(request) = self.pending_claim_requests.get_mut(&first_claim_txid_height.0) {
461 //... we need to verify equality between transaction outpoints and claim request
462 // outpoints to know if transaction is the original claim or a bumped one issued
464 let mut set_equality = true;
465 if request.outpoints().len() != tx.input.len() {
466 set_equality = false;
468 for (claim_inp, tx_inp) in request.outpoints().iter().zip(tx.input.iter()) {
469 if **claim_inp != tx_inp.previous_output {
470 set_equality = false;
475 macro_rules! clean_claim_request_after_safety_delay {
477 let entry = OnchainEventEntry {
480 event: OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() }
482 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
483 self.onchain_events_awaiting_threshold_conf.push(entry);
488 // If this is our transaction (or our counterparty spent all the outputs
489 // before we could anyway with same inputs order than us), wait for
490 // ANTI_REORG_DELAY and clean the RBF tracking map.
492 clean_claim_request_after_safety_delay!();
493 } else { // If false, generate new claim request with update outpoint set
494 let mut at_least_one_drop = false;
495 for input in tx.input.iter() {
496 if let Some(package) = request.split_package(&input.previous_output) {
497 claimed_outputs_material.push(package);
498 at_least_one_drop = true;
500 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
501 if request.outpoints().is_empty() {
502 clean_claim_request_after_safety_delay!();
505 //TODO: recompute soonest_timelock to avoid wasting a bit on fees
506 if at_least_one_drop {
507 bump_candidates.insert(first_claim_txid_height.0.clone(), request.clone());
510 break; //No need to iterate further, either tx is our or their
512 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
516 for package in claimed_outputs_material.drain(..) {
517 let entry = OnchainEventEntry {
520 event: OnchainEvent::ContentiousOutpoint { package },
522 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
523 self.onchain_events_awaiting_threshold_conf.push(entry);
528 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
529 let onchain_events_awaiting_threshold_conf =
530 self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
531 for entry in onchain_events_awaiting_threshold_conf {
532 if entry.has_reached_confirmation_threshold(height) {
534 OnchainEvent::Claim { claim_request } => {
535 // We may remove a whole set of claim outpoints here, as these one may have
536 // been aggregated in a single tx and claimed so atomically
537 if let Some(request) = self.pending_claim_requests.remove(&claim_request) {
538 for outpoint in request.outpoints() {
539 log_debug!(logger, "Removing claim tracking for {} due to maturation of claim tx {}.", outpoint, claim_request);
540 self.claimable_outpoints.remove(&outpoint);
544 OnchainEvent::ContentiousOutpoint { package } => {
545 log_debug!(logger, "Removing claim tracking due to maturation of claim tx for outpoints:");
546 log_debug!(logger, " {:?}", package.outpoints());
547 self.claimable_outpoints.remove(&package.outpoints()[0]);
551 self.onchain_events_awaiting_threshold_conf.push(entry);
555 // Check if any pending claim request must be rescheduled
556 for (first_claim_txid, ref request) in self.pending_claim_requests.iter() {
557 if let Some(h) = request.timer() {
559 bump_candidates.insert(*first_claim_txid, (*request).clone());
564 // Build, bump and rebroadcast tx accordingly
565 log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
566 for (first_claim_txid, request) in bump_candidates.iter() {
567 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &request, &*fee_estimator, &*logger) {
568 log_info!(logger, "Broadcasting RBF-bumped onchain {}", log_tx!(bump_tx));
569 broadcaster.broadcast_transaction(&bump_tx);
570 if let Some(request) = self.pending_claim_requests.get_mut(first_claim_txid) {
571 request.set_timer(new_timer);
572 request.set_feerate(new_feerate);
578 pub(crate) fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
585 B::Target: BroadcasterInterface,
586 F::Target: FeeEstimator,
589 let mut height = None;
590 for entry in self.onchain_events_awaiting_threshold_conf.iter() {
591 if entry.txid == *txid {
592 height = Some(entry.height);
597 if let Some(height) = height {
598 self.block_disconnected(height, broadcaster, fee_estimator, logger);
602 pub(crate) fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: F, logger: L)
603 where B::Target: BroadcasterInterface,
604 F::Target: FeeEstimator,
607 let mut bump_candidates = HashMap::new();
608 let onchain_events_awaiting_threshold_conf =
609 self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
610 for entry in onchain_events_awaiting_threshold_conf {
611 if entry.height >= height {
612 //- our claim tx on a commitment tx output
613 //- resurect outpoint back in its claimable set and regenerate tx
615 OnchainEvent::ContentiousOutpoint { package } => {
616 if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&package.outpoints()[0]) {
617 if let Some(request) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) {
618 request.merge_package(package);
619 // Using a HashMap guarantee us than if we have multiple outpoints getting
620 // resurrected only one bump claim tx is going to be broadcast
621 bump_candidates.insert(ancestor_claimable_txid.clone(), request.clone());
628 self.onchain_events_awaiting_threshold_conf.push(entry);
631 for (_, request) in bump_candidates.iter_mut() {
632 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &request, &&*fee_estimator, &&*logger) {
633 request.set_timer(new_timer);
634 request.set_feerate(new_feerate);
635 log_info!(logger, "Broadcasting onchain {}", log_tx!(bump_tx));
636 broadcaster.broadcast_transaction(&bump_tx);
639 for (ancestor_claim_txid, request) in bump_candidates.drain() {
640 self.pending_claim_requests.insert(ancestor_claim_txid.0, request);
642 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
643 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
644 let mut remove_request = Vec::new();
645 self.claimable_outpoints.retain(|_, ref v|
647 remove_request.push(v.0.clone());
650 for req in remove_request {
651 self.pending_claim_requests.remove(&req);
655 pub(crate) fn get_relevant_txids(&self) -> Vec<Txid> {
656 let mut txids: Vec<Txid> = self.onchain_events_awaiting_threshold_conf
658 .map(|entry| entry.txid)
660 txids.sort_unstable();
665 pub(crate) fn provide_latest_holder_tx(&mut self, tx: HolderCommitmentTransaction) {
666 self.prev_holder_commitment = Some(replace(&mut self.holder_commitment, tx));
667 self.holder_htlc_sigs = None;
670 // Normally holder HTLCs are signed at the same time as the holder commitment tx. However,
671 // in some configurations, the holder commitment tx has been signed and broadcast by a
672 // ChannelMonitor replica, so we handle that case here.
673 fn sign_latest_holder_htlcs(&mut self) {
674 if self.holder_htlc_sigs.is_none() {
675 let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
676 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, sigs));
680 // Normally only the latest commitment tx and HTLCs need to be signed. However, in some
681 // configurations we may have updated our holder commitment but a replica of the ChannelMonitor
682 // broadcast the previous one before we sync with it. We handle that case here.
683 fn sign_prev_holder_htlcs(&mut self) {
684 if self.prev_holder_htlc_sigs.is_none() {
685 if let Some(ref holder_commitment) = self.prev_holder_commitment {
686 let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(holder_commitment, &self.secp_ctx).expect("sign previous holder commitment");
687 self.prev_holder_htlc_sigs = Some(Self::extract_holder_sigs(holder_commitment, sigs));
692 fn extract_holder_sigs(holder_commitment: &HolderCommitmentTransaction, sigs: Vec<Signature>) -> Vec<Option<(usize, Signature)>> {
693 let mut ret = Vec::new();
694 for (htlc_idx, (holder_sig, htlc)) in sigs.iter().zip(holder_commitment.htlcs().iter()).enumerate() {
695 let tx_idx = htlc.transaction_output_index.unwrap();
696 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
697 ret[tx_idx as usize] = Some((htlc_idx, holder_sig.clone()));
702 //TODO: getting lastest holder transactions should be infallible and result in us "force-closing the channel", but we may
703 // have empty holder commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
704 // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
705 // to monitor before.
706 pub(crate) fn get_fully_signed_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
707 let (sig, htlc_sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("signing holder commitment");
708 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
709 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
712 #[cfg(any(test, feature="unsafe_revoked_tx_signing"))]
713 pub(crate) fn get_fully_signed_copy_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
714 let (sig, htlc_sigs) = self.signer.unsafe_sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
715 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
716 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
719 pub(crate) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
720 let mut htlc_tx = None;
721 let commitment_txid = self.holder_commitment.trust().txid();
722 // Check if the HTLC spends from the current holder commitment
723 if commitment_txid == outp.txid {
724 self.sign_latest_holder_htlcs();
725 if let &Some(ref htlc_sigs) = &self.holder_htlc_sigs {
726 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
727 let trusted_tx = self.holder_commitment.trust();
728 let counterparty_htlc_sig = self.holder_commitment.counterparty_htlc_sigs[*htlc_idx];
729 htlc_tx = Some(trusted_tx
730 .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
733 // If the HTLC doesn't spend the current holder commitment, check if it spends the previous one
734 if htlc_tx.is_none() && self.prev_holder_commitment.is_some() {
735 let commitment_txid = self.prev_holder_commitment.as_ref().unwrap().trust().txid();
736 if commitment_txid == outp.txid {
737 self.sign_prev_holder_htlcs();
738 if let &Some(ref htlc_sigs) = &self.prev_holder_htlc_sigs {
739 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
740 let holder_commitment = self.prev_holder_commitment.as_ref().unwrap();
741 let trusted_tx = holder_commitment.trust();
742 let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[*htlc_idx];
743 htlc_tx = Some(trusted_tx
744 .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
751 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
752 pub(crate) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
753 let latest_had_sigs = self.holder_htlc_sigs.is_some();
754 let prev_had_sigs = self.prev_holder_htlc_sigs.is_some();
755 let ret = self.get_fully_signed_htlc_tx(outp, preimage);
756 if !latest_had_sigs {
757 self.holder_htlc_sigs = None;
760 self.prev_holder_htlc_sigs = None;