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};
37 use alloc::collections::BTreeMap;
40 use core::mem::replace;
42 const MAX_ALLOC_SIZE: usize = 64*1024;
44 /// An entry for an [`OnchainEvent`], stating the block height when the event was observed and the
45 /// transaction causing it.
47 /// Used to determine when the on-chain event can be considered safe from a chain reorganization.
49 struct OnchainEventEntry {
55 impl OnchainEventEntry {
56 fn confirmation_threshold(&self) -> u32 {
57 self.height + ANTI_REORG_DELAY - 1
60 fn has_reached_confirmation_threshold(&self, height: u32) -> bool {
61 height >= self.confirmation_threshold()
65 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
66 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
69 /// Outpoint under claim process by our own tx, once this one get enough confirmations, we remove it from
70 /// bump-txn candidate buffer.
74 /// Claim tx aggregate multiple claimable outpoints. One of the outpoint may be claimed by a counterparty party tx.
75 /// In this case, we need to drop the outpoint and regenerate a new claim tx. By safety, we keep tracking
76 /// the outpoint to be sure to resurect it back to the claim tx if reorgs happen.
78 package: PackageTemplate,
82 impl_writeable_tlv_based!(OnchainEventEntry, {
84 (2, height, required),
88 impl_writeable_tlv_based_enum!(OnchainEvent,
90 (0, claim_request, required),
92 (1, ContentiousOutpoint) => {
93 (0, package, required),
97 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
98 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
99 match Readable::read(reader)? {
102 let vlen: u64 = Readable::read(reader)?;
103 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::core::mem::size_of::<Option<(usize, Signature)>>()));
105 ret.push(match Readable::read(reader)? {
107 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
108 _ => return Err(DecodeError::InvalidValue)
113 _ => Err(DecodeError::InvalidValue),
118 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
119 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
123 (vec.len() as u64).write(writer)?;
124 for opt in vec.iter() {
126 &Some((ref idx, ref sig)) => {
128 (*idx as u64).write(writer)?;
131 &None => 0u8.write(writer)?,
135 &None => 0u8.write(writer)?,
142 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
143 /// do RBF bumping if possible.
144 pub struct OnchainTxHandler<ChannelSigner: Sign> {
145 destination_script: Script,
146 holder_commitment: HolderCommitmentTransaction,
147 // holder_htlc_sigs and prev_holder_htlc_sigs are in the order as they appear in the commitment
148 // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
149 // the set of HTLCs in the HolderCommitmentTransaction.
150 holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
151 prev_holder_commitment: Option<HolderCommitmentTransaction>,
152 prev_holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
154 pub(super) signer: ChannelSigner,
155 pub(crate) channel_transaction_parameters: ChannelTransactionParameters,
157 // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
158 // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
159 // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
160 // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
161 // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
162 // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
163 // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
164 // we need to regenerate new claim request with reduced set of still-claimable outpoints.
165 // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
166 // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
167 // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
168 #[cfg(test)] // Used in functional_test to verify sanitization
169 pub(crate) pending_claim_requests: HashMap<Txid, PackageTemplate>,
171 pending_claim_requests: HashMap<Txid, PackageTemplate>,
173 // Used to link outpoints claimed in a connected block to a pending claim request.
174 // Key is outpoint than monitor parsing has detected we have keys/scripts to claim
175 // Value is (pending claim request identifier, confirmation_block), identifier
176 // is txid of the initial claiming transaction and is immutable until outpoint is
177 // post-anti-reorg-delay solved, confirmaiton_block is used to erase entry if
178 // block with output gets disconnected.
179 #[cfg(test)] // Used in functional_test to verify sanitization
180 pub claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
182 claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
184 locktimed_packages: BTreeMap<u32, Vec<PackageTemplate>>,
186 onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
188 pub(super) secp_ctx: Secp256k1<secp256k1::All>,
191 const SERIALIZATION_VERSION: u8 = 1;
192 const MIN_SERIALIZATION_VERSION: u8 = 1;
194 impl<ChannelSigner: Sign> OnchainTxHandler<ChannelSigner> {
195 pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
196 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
198 self.destination_script.write(writer)?;
199 self.holder_commitment.write(writer)?;
200 self.holder_htlc_sigs.write(writer)?;
201 self.prev_holder_commitment.write(writer)?;
202 self.prev_holder_htlc_sigs.write(writer)?;
204 self.channel_transaction_parameters.write(writer)?;
206 let mut key_data = VecWriter(Vec::new());
207 self.signer.write(&mut key_data)?;
208 assert!(key_data.0.len() < core::usize::MAX);
209 assert!(key_data.0.len() < core::u32::MAX as usize);
210 (key_data.0.len() as u32).write(writer)?;
211 writer.write_all(&key_data.0[..])?;
213 writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
214 for (ref ancestor_claim_txid, request) in self.pending_claim_requests.iter() {
215 ancestor_claim_txid.write(writer)?;
216 request.write(writer)?;
219 writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
220 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
222 claim_and_height.0.write(writer)?;
223 claim_and_height.1.write(writer)?;
226 writer.write_all(&byte_utils::be64_to_array(self.locktimed_packages.len() as u64))?;
227 for (ref locktime, ref packages) in self.locktimed_packages.iter() {
228 locktime.write(writer)?;
229 writer.write_all(&byte_utils::be64_to_array(packages.len() as u64))?;
230 for ref package in packages.iter() {
231 package.write(writer)?;
235 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_awaiting_threshold_conf.len() as u64))?;
236 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
237 entry.write(writer)?;
240 write_tlv_fields!(writer, {});
245 impl<'a, K: KeysInterface> ReadableArgs<&'a K> for OnchainTxHandler<K::Signer> {
246 fn read<R: io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
247 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
249 let destination_script = Readable::read(reader)?;
251 let holder_commitment = Readable::read(reader)?;
252 let holder_htlc_sigs = Readable::read(reader)?;
253 let prev_holder_commitment = Readable::read(reader)?;
254 let prev_holder_htlc_sigs = Readable::read(reader)?;
256 let channel_parameters = Readable::read(reader)?;
258 let keys_len: u32 = Readable::read(reader)?;
259 let mut keys_data = Vec::with_capacity(cmp::min(keys_len as usize, MAX_ALLOC_SIZE));
260 while keys_data.len() != keys_len as usize {
261 // Read 1KB at a time to avoid accidentally allocating 4GB on corrupted channel keys
262 let mut data = [0; 1024];
263 let read_slice = &mut data[0..cmp::min(1024, keys_len as usize - keys_data.len())];
264 reader.read_exact(read_slice)?;
265 keys_data.extend_from_slice(read_slice);
267 let signer = keys_manager.read_chan_signer(&keys_data)?;
269 let pending_claim_requests_len: u64 = Readable::read(reader)?;
270 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
271 for _ in 0..pending_claim_requests_len {
272 pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
275 let claimable_outpoints_len: u64 = Readable::read(reader)?;
276 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
277 for _ in 0..claimable_outpoints_len {
278 let outpoint = Readable::read(reader)?;
279 let ancestor_claim_txid = Readable::read(reader)?;
280 let height = Readable::read(reader)?;
281 claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
284 let locktimed_packages_len: u64 = Readable::read(reader)?;
285 let mut locktimed_packages = BTreeMap::new();
286 for _ in 0..locktimed_packages_len {
287 let locktime = Readable::read(reader)?;
288 let packages_len: u64 = Readable::read(reader)?;
289 let mut packages = Vec::with_capacity(cmp::min(packages_len as usize, MAX_ALLOC_SIZE / core::mem::size_of::<PackageTemplate>()));
290 for _ in 0..packages_len {
291 packages.push(Readable::read(reader)?);
293 locktimed_packages.insert(locktime, packages);
296 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
297 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
298 for _ in 0..waiting_threshold_conf_len {
299 onchain_events_awaiting_threshold_conf.push(Readable::read(reader)?);
302 read_tlv_fields!(reader, {});
304 let mut secp_ctx = Secp256k1::new();
305 secp_ctx.seeded_randomize(&keys_manager.get_secure_random_bytes());
307 Ok(OnchainTxHandler {
311 prev_holder_commitment,
312 prev_holder_htlc_sigs,
314 channel_transaction_parameters: channel_parameters,
317 pending_claim_requests,
318 onchain_events_awaiting_threshold_conf,
324 impl<ChannelSigner: Sign> OnchainTxHandler<ChannelSigner> {
325 pub(crate) fn new(destination_script: Script, signer: ChannelSigner, channel_parameters: ChannelTransactionParameters, holder_commitment: HolderCommitmentTransaction, secp_ctx: Secp256k1<secp256k1::All>) -> Self {
329 holder_htlc_sigs: None,
330 prev_holder_commitment: None,
331 prev_holder_htlc_sigs: None,
333 channel_transaction_parameters: channel_parameters,
334 pending_claim_requests: HashMap::new(),
335 claimable_outpoints: HashMap::new(),
336 locktimed_packages: BTreeMap::new(),
337 onchain_events_awaiting_threshold_conf: Vec::new(),
343 /// 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
344 /// (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.
345 /// Panics if there are signing errors, because signing operations in reaction to on-chain events
346 /// are not expected to fail, and if they do, we may lose funds.
347 fn generate_claim_tx<F: Deref, L: Deref>(&mut self, cur_height: u32, cached_request: &PackageTemplate, fee_estimator: &F, logger: &L) -> Option<(Option<u32>, u64, Transaction)>
348 where F::Target: FeeEstimator,
351 if cached_request.outpoints().len() == 0 { return None } // But don't prune pending claiming request yet, we may have to resurrect HTLCs
353 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
354 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
355 let new_timer = Some(cached_request.get_height_timer(cur_height));
356 if cached_request.is_malleable() {
357 let predicted_weight = cached_request.package_weight(&self.destination_script);
358 if let Some((output_value, new_feerate)) = cached_request.compute_package_output(predicted_weight, fee_estimator, logger) {
359 assert!(new_feerate != 0);
361 let transaction = cached_request.finalize_package(self, output_value, self.destination_script.clone(), logger).unwrap();
362 log_trace!(logger, "...with timer {} and feerate {}", new_timer.unwrap(), new_feerate);
363 assert!(predicted_weight >= transaction.get_weight());
364 return Some((new_timer, new_feerate, transaction))
367 // Note: Currently, amounts of holder outputs spending witnesses aren't used
368 // as we can't malleate spending package to increase their feerate. This
369 // should change with the remaining anchor output patchset.
370 if let Some(transaction) = cached_request.finalize_package(self, 0, self.destination_script.clone(), logger) {
371 return Some((None, 0, transaction));
377 /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
378 /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
379 /// Formerly this was named `block_connected`, but it is now also used for claiming an HTLC output
380 /// if we receive a preimage after force-close.
381 /// `conf_height` represents the height at which the transactions in `txn_matched` were
382 /// confirmed. This does not need to equal the current blockchain tip height, which should be
383 /// provided via `cur_height`, however it must never be higher than `cur_height`.
384 pub(crate) fn update_claims_view<B: Deref, F: Deref, L: Deref>(&mut self, txn_matched: &[&Transaction], requests: Vec<PackageTemplate>, conf_height: u32, cur_height: u32, broadcaster: &B, fee_estimator: &F, logger: &L)
385 where B::Target: BroadcasterInterface,
386 F::Target: FeeEstimator,
389 log_debug!(logger, "Updating claims view at height {} with {} matched transactions in block {} and {} claim requests", cur_height, txn_matched.len(), conf_height, requests.len());
390 let mut preprocessed_requests = Vec::with_capacity(requests.len());
391 let mut aggregated_request = None;
393 // Try to aggregate outputs if their timelock expiration isn't imminent (package timelock
394 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
395 for req in requests {
396 // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
397 if let Some(_) = self.claimable_outpoints.get(req.outpoints()[0]) {
398 log_info!(logger, "Ignoring second claim for outpoint {}:{}, already registered its claiming request", req.outpoints()[0].txid, req.outpoints()[0].vout);
400 let timelocked_equivalent_package = self.locktimed_packages.iter().map(|v| v.1.iter()).flatten()
401 .find(|locked_package| locked_package.outpoints() == req.outpoints());
402 if let Some(package) = timelocked_equivalent_package {
403 log_info!(logger, "Ignoring second claim for outpoint {}:{}, we already have one which we're waiting on a timelock at {} for.",
404 req.outpoints()[0].txid, req.outpoints()[0].vout, package.package_timelock());
408 if req.package_timelock() > cur_height + 1 {
409 log_info!(logger, "Delaying claim of package until its timelock at {} (current height {}), the following outpoints are spent:", req.package_timelock(), cur_height);
410 for outpoint in req.outpoints() {
411 log_info!(logger, " Outpoint {}", outpoint);
413 self.locktimed_packages.entry(req.package_timelock()).or_insert(Vec::new()).push(req);
417 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.timelock(), cur_height + CLTV_SHARED_CLAIM_BUFFER);
418 if req.timelock() <= cur_height + CLTV_SHARED_CLAIM_BUFFER || !req.aggregable() {
419 // Don't aggregate if outpoint package timelock is soon or marked as non-aggregable
420 preprocessed_requests.push(req);
421 } else if aggregated_request.is_none() {
422 aggregated_request = Some(req);
424 aggregated_request.as_mut().unwrap().merge_package(req);
428 if let Some(req) = aggregated_request {
429 preprocessed_requests.push(req);
432 // Claim everything up to and including cur_height + 1
433 let remaining_locked_packages = self.locktimed_packages.split_off(&(cur_height + 2));
434 for (pop_height, mut entry) in self.locktimed_packages.iter_mut() {
435 log_trace!(logger, "Restoring delayed claim of package(s) at their timelock at {}.", pop_height);
436 preprocessed_requests.append(&mut entry);
438 self.locktimed_packages = remaining_locked_packages;
440 // Generate claim transactions and track them to bump if necessary at
441 // height timer expiration (i.e in how many blocks we're going to take action).
442 for mut req in preprocessed_requests {
443 if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(cur_height, &req, &*fee_estimator, &*logger) {
444 req.set_timer(new_timer);
445 req.set_feerate(new_feerate);
446 let txid = tx.txid();
447 for k in req.outpoints() {
448 log_info!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
449 self.claimable_outpoints.insert(k.clone(), (txid, conf_height));
451 self.pending_claim_requests.insert(txid, req);
452 log_info!(logger, "Broadcasting onchain {}", log_tx!(tx));
453 broadcaster.broadcast_transaction(&tx);
457 let mut bump_candidates = HashMap::new();
458 for tx in txn_matched {
459 // Scan all input to verify is one of the outpoint spent is of interest for us
460 let mut claimed_outputs_material = Vec::new();
461 for inp in &tx.input {
462 if let Some(first_claim_txid_height) = self.claimable_outpoints.get(&inp.previous_output) {
463 // If outpoint has claim request pending on it...
464 if let Some(request) = self.pending_claim_requests.get_mut(&first_claim_txid_height.0) {
465 //... we need to verify equality between transaction outpoints and claim request
466 // outpoints to know if transaction is the original claim or a bumped one issued
468 let mut set_equality = true;
469 if request.outpoints().len() != tx.input.len() {
470 set_equality = false;
472 for (claim_inp, tx_inp) in request.outpoints().iter().zip(tx.input.iter()) {
473 if **claim_inp != tx_inp.previous_output {
474 set_equality = false;
479 macro_rules! clean_claim_request_after_safety_delay {
481 let entry = OnchainEventEntry {
484 event: OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() }
486 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
487 self.onchain_events_awaiting_threshold_conf.push(entry);
492 // If this is our transaction (or our counterparty spent all the outputs
493 // before we could anyway with same inputs order than us), wait for
494 // ANTI_REORG_DELAY and clean the RBF tracking map.
496 clean_claim_request_after_safety_delay!();
497 } else { // If false, generate new claim request with update outpoint set
498 let mut at_least_one_drop = false;
499 for input in tx.input.iter() {
500 if let Some(package) = request.split_package(&input.previous_output) {
501 claimed_outputs_material.push(package);
502 at_least_one_drop = true;
504 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
505 if request.outpoints().is_empty() {
506 clean_claim_request_after_safety_delay!();
509 //TODO: recompute soonest_timelock to avoid wasting a bit on fees
510 if at_least_one_drop {
511 bump_candidates.insert(first_claim_txid_height.0.clone(), request.clone());
514 break; //No need to iterate further, either tx is our or their
516 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
520 for package in claimed_outputs_material.drain(..) {
521 let entry = OnchainEventEntry {
524 event: OnchainEvent::ContentiousOutpoint { package },
526 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
527 self.onchain_events_awaiting_threshold_conf.push(entry);
532 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
533 let onchain_events_awaiting_threshold_conf =
534 self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
535 for entry in onchain_events_awaiting_threshold_conf {
536 if entry.has_reached_confirmation_threshold(cur_height) {
538 OnchainEvent::Claim { claim_request } => {
539 // We may remove a whole set of claim outpoints here, as these one may have
540 // been aggregated in a single tx and claimed so atomically
541 if let Some(request) = self.pending_claim_requests.remove(&claim_request) {
542 for outpoint in request.outpoints() {
543 log_debug!(logger, "Removing claim tracking for {} due to maturation of claim tx {}.", outpoint, claim_request);
544 self.claimable_outpoints.remove(&outpoint);
548 OnchainEvent::ContentiousOutpoint { package } => {
549 log_debug!(logger, "Removing claim tracking due to maturation of claim tx for outpoints:");
550 log_debug!(logger, " {:?}", package.outpoints());
551 self.claimable_outpoints.remove(&package.outpoints()[0]);
555 self.onchain_events_awaiting_threshold_conf.push(entry);
559 // Check if any pending claim request must be rescheduled
560 for (first_claim_txid, ref request) in self.pending_claim_requests.iter() {
561 if let Some(h) = request.timer() {
563 bump_candidates.insert(*first_claim_txid, (*request).clone());
568 // Build, bump and rebroadcast tx accordingly
569 log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
570 for (first_claim_txid, request) in bump_candidates.iter() {
571 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(cur_height, &request, &*fee_estimator, &*logger) {
572 log_info!(logger, "Broadcasting RBF-bumped onchain {}", log_tx!(bump_tx));
573 broadcaster.broadcast_transaction(&bump_tx);
574 if let Some(request) = self.pending_claim_requests.get_mut(first_claim_txid) {
575 request.set_timer(new_timer);
576 request.set_feerate(new_feerate);
582 pub(crate) fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
589 B::Target: BroadcasterInterface,
590 F::Target: FeeEstimator,
593 let mut height = None;
594 for entry in self.onchain_events_awaiting_threshold_conf.iter() {
595 if entry.txid == *txid {
596 height = Some(entry.height);
601 if let Some(height) = height {
602 self.block_disconnected(height, broadcaster, fee_estimator, logger);
606 pub(crate) fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: F, logger: L)
607 where B::Target: BroadcasterInterface,
608 F::Target: FeeEstimator,
611 let mut bump_candidates = HashMap::new();
612 let onchain_events_awaiting_threshold_conf =
613 self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
614 for entry in onchain_events_awaiting_threshold_conf {
615 if entry.height >= height {
616 //- our claim tx on a commitment tx output
617 //- resurect outpoint back in its claimable set and regenerate tx
619 OnchainEvent::ContentiousOutpoint { package } => {
620 if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&package.outpoints()[0]) {
621 if let Some(request) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) {
622 request.merge_package(package);
623 // Using a HashMap guarantee us than if we have multiple outpoints getting
624 // resurrected only one bump claim tx is going to be broadcast
625 bump_candidates.insert(ancestor_claimable_txid.clone(), request.clone());
632 self.onchain_events_awaiting_threshold_conf.push(entry);
635 for (_, request) in bump_candidates.iter_mut() {
636 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &request, &&*fee_estimator, &&*logger) {
637 request.set_timer(new_timer);
638 request.set_feerate(new_feerate);
639 log_info!(logger, "Broadcasting onchain {}", log_tx!(bump_tx));
640 broadcaster.broadcast_transaction(&bump_tx);
643 for (ancestor_claim_txid, request) in bump_candidates.drain() {
644 self.pending_claim_requests.insert(ancestor_claim_txid.0, request);
646 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
647 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
648 let mut remove_request = Vec::new();
649 self.claimable_outpoints.retain(|_, ref v|
651 remove_request.push(v.0.clone());
654 for req in remove_request {
655 self.pending_claim_requests.remove(&req);
659 pub(crate) fn get_relevant_txids(&self) -> Vec<Txid> {
660 let mut txids: Vec<Txid> = self.onchain_events_awaiting_threshold_conf
662 .map(|entry| entry.txid)
664 txids.sort_unstable();
669 pub(crate) fn provide_latest_holder_tx(&mut self, tx: HolderCommitmentTransaction) {
670 self.prev_holder_commitment = Some(replace(&mut self.holder_commitment, tx));
671 self.holder_htlc_sigs = None;
674 // Normally holder HTLCs are signed at the same time as the holder commitment tx. However,
675 // in some configurations, the holder commitment tx has been signed and broadcast by a
676 // ChannelMonitor replica, so we handle that case here.
677 fn sign_latest_holder_htlcs(&mut self) {
678 if self.holder_htlc_sigs.is_none() {
679 let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
680 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, sigs));
684 // Normally only the latest commitment tx and HTLCs need to be signed. However, in some
685 // configurations we may have updated our holder commitment but a replica of the ChannelMonitor
686 // broadcast the previous one before we sync with it. We handle that case here.
687 fn sign_prev_holder_htlcs(&mut self) {
688 if self.prev_holder_htlc_sigs.is_none() {
689 if let Some(ref holder_commitment) = self.prev_holder_commitment {
690 let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(holder_commitment, &self.secp_ctx).expect("sign previous holder commitment");
691 self.prev_holder_htlc_sigs = Some(Self::extract_holder_sigs(holder_commitment, sigs));
696 fn extract_holder_sigs(holder_commitment: &HolderCommitmentTransaction, sigs: Vec<Signature>) -> Vec<Option<(usize, Signature)>> {
697 let mut ret = Vec::new();
698 for (htlc_idx, (holder_sig, htlc)) in sigs.iter().zip(holder_commitment.htlcs().iter()).enumerate() {
699 let tx_idx = htlc.transaction_output_index.unwrap();
700 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
701 ret[tx_idx as usize] = Some((htlc_idx, holder_sig.clone()));
706 //TODO: getting lastest holder transactions should be infallible and result in us "force-closing the channel", but we may
707 // have empty holder commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
708 // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
709 // to monitor before.
710 pub(crate) fn get_fully_signed_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
711 let (sig, htlc_sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("signing holder commitment");
712 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
713 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
716 #[cfg(any(test, feature="unsafe_revoked_tx_signing"))]
717 pub(crate) fn get_fully_signed_copy_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
718 let (sig, htlc_sigs) = self.signer.unsafe_sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
719 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
720 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
723 pub(crate) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
724 let mut htlc_tx = None;
725 let commitment_txid = self.holder_commitment.trust().txid();
726 // Check if the HTLC spends from the current holder commitment
727 if commitment_txid == outp.txid {
728 self.sign_latest_holder_htlcs();
729 if let &Some(ref htlc_sigs) = &self.holder_htlc_sigs {
730 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
731 let trusted_tx = self.holder_commitment.trust();
732 let counterparty_htlc_sig = self.holder_commitment.counterparty_htlc_sigs[*htlc_idx];
733 htlc_tx = Some(trusted_tx
734 .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
737 // If the HTLC doesn't spend the current holder commitment, check if it spends the previous one
738 if htlc_tx.is_none() && self.prev_holder_commitment.is_some() {
739 let commitment_txid = self.prev_holder_commitment.as_ref().unwrap().trust().txid();
740 if commitment_txid == outp.txid {
741 self.sign_prev_holder_htlcs();
742 if let &Some(ref htlc_sigs) = &self.prev_holder_htlc_sigs {
743 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
744 let holder_commitment = self.prev_holder_commitment.as_ref().unwrap();
745 let trusted_tx = holder_commitment.trust();
746 let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[*htlc_idx];
747 htlc_tx = Some(trusted_tx
748 .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
755 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
756 pub(crate) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
757 let latest_had_sigs = self.holder_htlc_sigs.is_some();
758 let prev_had_sigs = self.prev_holder_htlc_sigs.is_some();
759 let ret = self.get_fully_signed_htlc_tx(outp, preimage);
760 if !latest_had_sigs {
761 self.holder_htlc_sigs = None;
764 self.prev_holder_htlc_sigs = None;