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, TxIn, TxOut, SigHashType};
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::channelmanager::PaymentPreimage;
27 use ln::chan_utils::{TxCreationKeys, ChannelTransactionParameters, HolderCommitmentTransaction};
28 use chain::chaininterface::{FeeEstimator, BroadcasterInterface, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT};
29 use chain::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER, InputMaterial, ClaimRequest};
30 use chain::keysinterface::{ChannelKeys, KeysInterface};
31 use util::logger::Logger;
32 use util::ser::{Readable, ReadableArgs, Writer, Writeable, VecWriter};
35 use std::collections::{HashMap, hash_map};
38 use std::mem::replace;
40 const MAX_ALLOC_SIZE: usize = 64*1024;
42 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
43 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
44 #[derive(Clone, PartialEq)]
46 /// Outpoint under claim process by our own tx, once this one get enough confirmations, we remove it from
47 /// bump-txn candidate buffer.
51 /// Claim tx aggregate multiple claimable outpoints. One of the outpoint may be claimed by a counterparty party tx.
52 /// In this case, we need to drop the outpoint and regenerate a new claim tx. By safety, we keep tracking
53 /// the outpoint to be sure to resurect it back to the claim tx if reorgs happen.
55 outpoint: BitcoinOutPoint,
56 input_material: InputMaterial,
60 /// Higher-level cache structure needed to re-generate bumped claim txn if needed
61 #[derive(Clone, PartialEq)]
62 pub struct ClaimTxBumpMaterial {
63 // At every block tick, used to check if pending claiming tx is taking too
64 // much time for confirmation and we need to bump it.
65 height_timer: Option<u32>,
66 // Tracked in case of reorg to wipe out now-superflous bump material
67 feerate_previous: u32,
68 // Soonest timelocks among set of outpoints claimed, used to compute
69 // a priority of not feerate
70 soonest_timelock: u32,
71 // Cache of script, pubkey, sig or key to solve claimable outputs scriptpubkey.
72 per_input_material: HashMap<BitcoinOutPoint, InputMaterial>,
75 impl Writeable for ClaimTxBumpMaterial {
76 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
77 self.height_timer.write(writer)?;
78 writer.write_all(&byte_utils::be32_to_array(self.feerate_previous))?;
79 writer.write_all(&byte_utils::be32_to_array(self.soonest_timelock))?;
80 writer.write_all(&byte_utils::be64_to_array(self.per_input_material.len() as u64))?;
81 for (outp, tx_material) in self.per_input_material.iter() {
83 tx_material.write(writer)?;
89 impl Readable for ClaimTxBumpMaterial {
90 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
91 let height_timer = Readable::read(reader)?;
92 let feerate_previous = Readable::read(reader)?;
93 let soonest_timelock = Readable::read(reader)?;
94 let per_input_material_len: u64 = Readable::read(reader)?;
95 let mut per_input_material = HashMap::with_capacity(cmp::min(per_input_material_len as usize, MAX_ALLOC_SIZE / 128));
96 for _ in 0 ..per_input_material_len {
97 let outpoint = Readable::read(reader)?;
98 let input_material = Readable::read(reader)?;
99 per_input_material.insert(outpoint, input_material);
101 Ok(Self { height_timer, feerate_previous, soonest_timelock, per_input_material })
105 #[derive(PartialEq, Clone, Copy)]
106 pub(crate) enum InputDescriptors {
111 RevokedOutput, // either a revoked to_holder output on commitment tx, a revoked HTLC-Timeout output or a revoked HTLC-Success output
114 impl Writeable for InputDescriptors {
115 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
117 &InputDescriptors::RevokedOfferedHTLC => {
118 writer.write_all(&[0; 1])?;
120 &InputDescriptors::RevokedReceivedHTLC => {
121 writer.write_all(&[1; 1])?;
123 &InputDescriptors::OfferedHTLC => {
124 writer.write_all(&[2; 1])?;
126 &InputDescriptors::ReceivedHTLC => {
127 writer.write_all(&[3; 1])?;
129 &InputDescriptors::RevokedOutput => {
130 writer.write_all(&[4; 1])?;
137 impl Readable for InputDescriptors {
138 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
139 let input_descriptor = match <u8 as Readable>::read(reader)? {
141 InputDescriptors::RevokedOfferedHTLC
144 InputDescriptors::RevokedReceivedHTLC
147 InputDescriptors::OfferedHTLC
150 InputDescriptors::ReceivedHTLC
153 InputDescriptors::RevokedOutput
155 _ => return Err(DecodeError::InvalidValue),
161 macro_rules! subtract_high_prio_fee {
162 ($logger: ident, $fee_estimator: expr, $value: expr, $predicted_weight: expr, $used_feerate: expr) => {
164 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority).into();
165 let mut fee = $used_feerate as u64 * $predicted_weight / 1000;
167 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal).into();
168 fee = $used_feerate as u64 * $predicted_weight / 1000;
169 if $value <= fee.into() {
170 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background).into();
171 fee = $used_feerate as u64 * $predicted_weight / 1000;
173 log_error!($logger, "Failed to generate an on-chain punishment tx as even low priority fee ({} sat) was more than the entire claim balance ({} sat)",
177 log_warn!($logger, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
183 log_warn!($logger, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
196 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
197 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
198 match Readable::read(reader)? {
201 let vlen: u64 = Readable::read(reader)?;
202 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<Option<(usize, Signature)>>()));
204 ret.push(match Readable::read(reader)? {
206 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
207 _ => return Err(DecodeError::InvalidValue)
212 _ => Err(DecodeError::InvalidValue),
217 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
218 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
222 (vec.len() as u64).write(writer)?;
223 for opt in vec.iter() {
225 &Some((ref idx, ref sig)) => {
227 (*idx as u64).write(writer)?;
230 &None => 0u8.write(writer)?,
234 &None => 0u8.write(writer)?,
241 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
242 /// do RBF bumping if possible.
243 pub struct OnchainTxHandler<ChanSigner: ChannelKeys> {
244 destination_script: Script,
245 holder_commitment: HolderCommitmentTransaction,
246 // holder_htlc_sigs and prev_holder_htlc_sigs are in the order as they appear in the commitment
247 // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
248 // the set of HTLCs in the HolderCommitmentTransaction.
249 holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
250 prev_holder_commitment: Option<HolderCommitmentTransaction>,
251 prev_holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
253 key_storage: ChanSigner,
254 pub(crate) channel_transaction_parameters: ChannelTransactionParameters,
256 // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
257 // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
258 // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
259 // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
260 // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
261 // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
262 // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
263 // we need to regenerate new claim request with reduced set of still-claimable outpoints.
264 // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
265 // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
266 // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
267 #[cfg(test)] // Used in functional_test to verify sanitization
268 pub pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
270 pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
272 // Used to link outpoints claimed in a connected block to a pending claim request.
273 // Key is outpoint than monitor parsing has detected we have keys/scripts to claim
274 // Value is (pending claim request identifier, confirmation_block), identifier
275 // is txid of the initial claiming transaction and is immutable until outpoint is
276 // post-anti-reorg-delay solved, confirmaiton_block is used to erase entry if
277 // block with output gets disconnected.
278 #[cfg(test)] // Used in functional_test to verify sanitization
279 pub claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
281 claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
283 onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
287 secp_ctx: Secp256k1<secp256k1::All>,
290 impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
291 pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
292 self.destination_script.write(writer)?;
293 self.holder_commitment.write(writer)?;
294 self.holder_htlc_sigs.write(writer)?;
295 self.prev_holder_commitment.write(writer)?;
296 self.prev_holder_htlc_sigs.write(writer)?;
298 self.channel_transaction_parameters.write(writer)?;
300 let mut key_data = VecWriter(Vec::new());
301 self.key_storage.write(&mut key_data)?;
302 assert!(key_data.0.len() < std::usize::MAX);
303 assert!(key_data.0.len() < std::u32::MAX as usize);
304 (key_data.0.len() as u32).write(writer)?;
305 writer.write_all(&key_data.0[..])?;
307 writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
308 for (ref ancestor_claim_txid, claim_tx_data) in self.pending_claim_requests.iter() {
309 ancestor_claim_txid.write(writer)?;
310 claim_tx_data.write(writer)?;
313 writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
314 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
316 claim_and_height.0.write(writer)?;
317 claim_and_height.1.write(writer)?;
320 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
321 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
322 writer.write_all(&byte_utils::be32_to_array(**target))?;
323 writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
324 for ev in events.iter() {
326 OnchainEvent::Claim { ref claim_request } => {
327 writer.write_all(&[0; 1])?;
328 claim_request.write(writer)?;
330 OnchainEvent::ContentiousOutpoint { ref outpoint, ref input_material } => {
331 writer.write_all(&[1; 1])?;
332 outpoint.write(writer)?;
333 input_material.write(writer)?;
338 self.latest_height.write(writer)?;
343 impl<'a, K: KeysInterface> ReadableArgs<&'a K> for OnchainTxHandler<K::ChanKeySigner> {
344 fn read<R: ::std::io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
345 let destination_script = Readable::read(reader)?;
347 let holder_commitment = Readable::read(reader)?;
348 let holder_htlc_sigs = Readable::read(reader)?;
349 let prev_holder_commitment = Readable::read(reader)?;
350 let prev_holder_htlc_sigs = Readable::read(reader)?;
352 let channel_parameters = Readable::read(reader)?;
354 let keys_len: u32 = Readable::read(reader)?;
355 let mut keys_data = Vec::with_capacity(cmp::min(keys_len as usize, MAX_ALLOC_SIZE));
356 while keys_data.len() != keys_len as usize {
357 // Read 1KB at a time to avoid accidentally allocating 4GB on corrupted channel keys
358 let mut data = [0; 1024];
359 let read_slice = &mut data[0..cmp::min(1024, keys_len as usize - keys_data.len())];
360 reader.read_exact(read_slice)?;
361 keys_data.extend_from_slice(read_slice);
363 let key_storage = keys_manager.read_chan_signer(&keys_data)?;
365 let pending_claim_requests_len: u64 = Readable::read(reader)?;
366 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
367 for _ in 0..pending_claim_requests_len {
368 pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
371 let claimable_outpoints_len: u64 = Readable::read(reader)?;
372 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
373 for _ in 0..claimable_outpoints_len {
374 let outpoint = Readable::read(reader)?;
375 let ancestor_claim_txid = Readable::read(reader)?;
376 let height = Readable::read(reader)?;
377 claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
379 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
380 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
381 for _ in 0..waiting_threshold_conf_len {
382 let height_target = Readable::read(reader)?;
383 let events_len: u64 = Readable::read(reader)?;
384 let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
385 for _ in 0..events_len {
386 let ev = match <u8 as Readable>::read(reader)? {
388 let claim_request = Readable::read(reader)?;
389 OnchainEvent::Claim {
394 let outpoint = Readable::read(reader)?;
395 let input_material = Readable::read(reader)?;
396 OnchainEvent::ContentiousOutpoint {
401 _ => return Err(DecodeError::InvalidValue),
405 onchain_events_waiting_threshold_conf.insert(height_target, events);
407 let latest_height = Readable::read(reader)?;
409 Ok(OnchainTxHandler {
413 prev_holder_commitment,
414 prev_holder_htlc_sigs,
416 channel_transaction_parameters: channel_parameters,
418 pending_claim_requests,
419 onchain_events_waiting_threshold_conf,
421 secp_ctx: Secp256k1::new(),
426 impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
427 pub(crate) fn new(destination_script: Script, keys: ChanSigner, channel_parameters: ChannelTransactionParameters, holder_commitment: HolderCommitmentTransaction) -> Self {
429 let key_storage = keys;
434 holder_htlc_sigs: None,
435 prev_holder_commitment: None,
436 prev_holder_htlc_sigs: None,
438 channel_transaction_parameters: channel_parameters,
439 pending_claim_requests: HashMap::new(),
440 claimable_outpoints: HashMap::new(),
441 onchain_events_waiting_threshold_conf: HashMap::new(),
444 secp_ctx: Secp256k1::new(),
448 pub(crate) fn get_witnesses_weight(inputs: &[InputDescriptors]) -> usize {
449 let mut tx_weight = 2; // count segwit flags
451 // We use expected weight (and not actual) as signatures and time lock delays may vary
452 tx_weight += match inp {
453 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
454 &InputDescriptors::RevokedOfferedHTLC => {
455 1 + 1 + 73 + 1 + 33 + 1 + 133
457 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
458 &InputDescriptors::RevokedReceivedHTLC => {
459 1 + 1 + 73 + 1 + 33 + 1 + 139
461 // number_of_witness_elements + sig_length + counterpartyhtlc_sig + preimage_length + preimage + witness_script_length + witness_script
462 &InputDescriptors::OfferedHTLC => {
463 1 + 1 + 73 + 1 + 32 + 1 + 133
465 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
466 &InputDescriptors::ReceivedHTLC => {
467 1 + 1 + 73 + 1 + 1 + 1 + 139
469 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
470 &InputDescriptors::RevokedOutput => {
471 1 + 1 + 73 + 1 + 1 + 1 + 77
478 /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
479 /// output detection, we generate a first version of a claim tx and associate to it a height timer. A height timer is an absolute block
480 /// height than once reached we should generate a new bumped "version" of the claim tx to be sure than we safely claim outputs before
481 /// than our counterparty can do it too. If timelock expires soon, height timer is going to be scale down in consequence to increase
482 /// frequency of the bump and so increase our bets of success.
483 fn get_height_timer(current_height: u32, timelock_expiration: u32) -> u32 {
484 if timelock_expiration <= current_height + 3 {
485 return current_height + 1
486 } else if timelock_expiration - current_height <= 15 {
487 return current_height + 3
492 /// 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
493 /// (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.
494 /// Panics if there are signing errors, because signing operations in reaction to on-chain events
495 /// are not expected to fail, and if they do, we may lose funds.
496 fn generate_claim_tx<F: Deref, L: Deref>(&mut self, height: u32, cached_claim_datas: &ClaimTxBumpMaterial, fee_estimator: &F, logger: &L) -> Option<(Option<u32>, u32, Transaction)>
497 where F::Target: FeeEstimator,
500 if cached_claim_datas.per_input_material.len() == 0 { return None } // But don't prune pending claiming request yet, we may have to resurrect HTLCs
501 let mut inputs = Vec::new();
502 for outp in cached_claim_datas.per_input_material.keys() {
503 log_trace!(logger, "Outpoint {}:{}", outp.txid, outp.vout);
505 previous_output: *outp,
506 script_sig: Script::new(),
507 sequence: 0xfffffffd,
511 let mut bumped_tx = Transaction {
516 script_pubkey: self.destination_script.clone(),
521 macro_rules! RBF_bump {
522 ($amount: expr, $old_feerate: expr, $fee_estimator: expr, $predicted_weight: expr) => {
524 let mut used_feerate: u32;
525 // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
526 let new_fee = if $old_feerate < $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) {
527 let mut value = $amount;
528 if subtract_high_prio_fee!(logger, $fee_estimator, value, $predicted_weight, used_feerate) {
529 // Overflow check is done in subtract_high_prio_fee
532 log_trace!(logger, "Can't new-estimation bump new claiming tx, amount {} is too small", $amount);
535 // ...else just increase the previous feerate by 25% (because that's a nice number)
537 let fee = $old_feerate as u64 * ($predicted_weight as u64) / 750;
539 log_trace!(logger, "Can't 25% bump new claiming tx, amount {} is too small", $amount);
545 let previous_fee = $old_feerate as u64 * ($predicted_weight as u64) / 1000;
546 let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * ($predicted_weight as u64) / 1000;
547 // BIP 125 Opt-in Full Replace-by-Fee Signaling
548 // * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
549 // * 4. The replacement transaction must also pay for its own bandwidth at or above the rate set by the node's minimum relay fee setting.
550 let new_fee = if new_fee < previous_fee + min_relay_fee {
551 new_fee + previous_fee + min_relay_fee - new_fee
555 Some((new_fee, new_fee * 1000 / ($predicted_weight as u64)))
560 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
561 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
562 let new_timer = Some(Self::get_height_timer(height, cached_claim_datas.soonest_timelock));
563 let mut inputs_witnesses_weight = 0;
565 let mut dynamic_fee = true;
566 for per_outp_material in cached_claim_datas.per_input_material.values() {
567 match per_outp_material {
568 &InputMaterial::Revoked { ref input_descriptor, ref amount, .. } => {
569 inputs_witnesses_weight += Self::get_witnesses_weight(&[*input_descriptor]);
572 &InputMaterial::CounterpartyHTLC { ref preimage, ref htlc, .. } => {
573 inputs_witnesses_weight += Self::get_witnesses_weight(if preimage.is_some() { &[InputDescriptors::OfferedHTLC] } else { &[InputDescriptors::ReceivedHTLC] });
574 amt += htlc.amount_msat / 1000;
576 &InputMaterial::HolderHTLC { .. } => {
579 &InputMaterial::Funding { .. } => {
585 let predicted_weight = (bumped_tx.get_weight() + inputs_witnesses_weight) as u64;
587 // If old feerate is 0, first iteration of this claim, use normal fee calculation
588 if cached_claim_datas.feerate_previous != 0 {
589 if let Some((new_fee, feerate)) = RBF_bump!(amt, cached_claim_datas.feerate_previous, fee_estimator, predicted_weight) {
590 // If new computed fee is superior at the whole claimable amount burn all in fees
591 if new_fee as u64 > amt {
592 bumped_tx.output[0].value = 0;
594 bumped_tx.output[0].value = amt - new_fee as u64;
596 new_feerate = feerate;
597 } else { return None; }
599 if subtract_high_prio_fee!(logger, fee_estimator, amt, predicted_weight, new_feerate) {
600 bumped_tx.output[0].value = amt;
601 } else { return None; }
603 assert!(new_feerate != 0);
605 for (i, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
606 match per_outp_material {
607 &InputMaterial::Revoked { ref per_commitment_point, ref counterparty_delayed_payment_base_key, ref counterparty_htlc_base_key, ref per_commitment_key, ref input_descriptor, ref amount, ref htlc, ref on_counterparty_tx_csv } => {
608 if let Ok(chan_keys) = TxCreationKeys::derive_new(&self.secp_ctx, &per_commitment_point, counterparty_delayed_payment_base_key, counterparty_htlc_base_key, &self.key_storage.pubkeys().revocation_basepoint, &self.key_storage.pubkeys().htlc_basepoint) {
610 let witness_script = if let Some(ref htlc) = *htlc {
611 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key)
613 chan_utils::get_revokeable_redeemscript(&chan_keys.revocation_key, *on_counterparty_tx_csv, &chan_keys.broadcaster_delayed_payment_key)
616 let sig = self.key_storage.sign_justice_transaction(&bumped_tx, i, *amount, &per_commitment_key, htlc, &self.secp_ctx).expect("sign justice tx");
617 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
618 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
620 bumped_tx.input[i].witness.push(chan_keys.revocation_key.clone().serialize().to_vec());
622 bumped_tx.input[i].witness.push(vec!(1));
624 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
626 log_trace!(logger, "Going to broadcast Penalty Transaction {} claiming revoked {} output {} from {} with new feerate {}...", bumped_tx.txid(), if *input_descriptor == InputDescriptors::RevokedOutput { "to_holder" } else if *input_descriptor == InputDescriptors::RevokedOfferedHTLC { "offered" } else if *input_descriptor == InputDescriptors::RevokedReceivedHTLC { "received" } else { "" }, outp.vout, outp.txid, new_feerate);
629 &InputMaterial::CounterpartyHTLC { ref per_commitment_point, ref counterparty_delayed_payment_base_key, ref counterparty_htlc_base_key, ref preimage, ref htlc } => {
630 if let Ok(chan_keys) = TxCreationKeys::derive_new(&self.secp_ctx, &per_commitment_point, counterparty_delayed_payment_base_key, counterparty_htlc_base_key, &self.key_storage.pubkeys().revocation_basepoint, &self.key_storage.pubkeys().htlc_basepoint) {
631 let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
633 if !preimage.is_some() { bumped_tx.lock_time = htlc.cltv_expiry }; // Right now we don't aggregate time-locked transaction, if we do we should set lock_time before to avoid breaking hash computation
634 let sig = self.key_storage.sign_counterparty_htlc_transaction(&bumped_tx, i, &htlc.amount_msat / 1000, &per_commitment_point, htlc, &self.secp_ctx).expect("sign counterparty HTLC tx");
635 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
636 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
637 if let &Some(preimage) = preimage {
638 bumped_tx.input[i].witness.push(preimage.0.to_vec());
640 // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
641 bumped_tx.input[i].witness.push(vec![]);
643 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
644 log_trace!(logger, "Going to broadcast Claim Transaction {} claiming counterparty {} htlc output {} from {} with new feerate {}...", bumped_tx.txid(), if preimage.is_some() { "offered" } else { "received" }, outp.vout, outp.txid, new_feerate);
650 log_trace!(logger, "...with timer {}", new_timer.unwrap());
651 assert!(predicted_weight >= bumped_tx.get_weight() as u64);
652 return Some((new_timer, new_feerate as u32, bumped_tx))
654 for (_, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
655 match per_outp_material {
656 &InputMaterial::HolderHTLC { ref preimage, ref amount } => {
657 let htlc_tx = self.get_fully_signed_htlc_tx(outp, preimage);
658 if let Some(htlc_tx) = htlc_tx {
659 let feerate = (amount - htlc_tx.output[0].value) * 1000 / htlc_tx.get_weight() as u64;
660 // Timer set to $NEVER given we can't bump tx without anchor outputs
661 log_trace!(logger, "Going to broadcast Holder HTLC-{} claiming HTLC output {} from {}...", if preimage.is_some() { "Success" } else { "Timeout" }, outp.vout, outp.txid);
662 return Some((None, feerate as u32, htlc_tx));
666 &InputMaterial::Funding { ref funding_redeemscript } => {
667 let signed_tx = self.get_fully_signed_holder_tx(funding_redeemscript);
668 // Timer set to $NEVER given we can't bump tx without anchor outputs
669 log_trace!(logger, "Going to broadcast Holder Transaction {} claiming funding output {} from {}...", signed_tx.txid(), outp.vout, outp.txid);
670 return Some((None, self.holder_commitment.feerate_per_kw(), signed_tx));
679 /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
680 /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
681 /// Formerly this was named `block_connected`, but it is now also used for claiming an HTLC output
682 /// if we receive a preimage after force-close.
683 pub(crate) fn update_claims_view<B: Deref, F: Deref, L: Deref>(&mut self, txn_matched: &[&Transaction], claimable_outpoints: Vec<ClaimRequest>, latest_height: Option<u32>, broadcaster: &B, fee_estimator: &F, logger: &L)
684 where B::Target: BroadcasterInterface,
685 F::Target: FeeEstimator,
688 let height = match latest_height {
690 None => self.latest_height,
692 log_trace!(logger, "Updating claims view at height {} with {} matched transactions and {} claim requests", height, txn_matched.len(), claimable_outpoints.len());
693 let mut new_claims = Vec::new();
694 let mut aggregated_claim = HashMap::new();
695 let mut aggregated_soonest = ::std::u32::MAX;
697 // Try to aggregate outputs if their timelock expiration isn't imminent (absolute_timelock
698 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
699 for req in claimable_outpoints {
700 // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
701 if let Some(_) = self.claimable_outpoints.get(&req.outpoint) { log_trace!(logger, "Bouncing off outpoint {}:{}, already registered its claiming request", req.outpoint.txid, req.outpoint.vout); } else {
702 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.absolute_timelock, height + CLTV_SHARED_CLAIM_BUFFER);
703 if req.absolute_timelock <= height + CLTV_SHARED_CLAIM_BUFFER || !req.aggregable { // Don't aggregate if outpoint absolute timelock is soon or marked as non-aggregable
704 let mut single_input = HashMap::new();
705 single_input.insert(req.outpoint, req.witness_data);
706 new_claims.push((req.absolute_timelock, single_input));
708 aggregated_claim.insert(req.outpoint, req.witness_data);
709 if req.absolute_timelock < aggregated_soonest {
710 aggregated_soonest = req.absolute_timelock;
715 new_claims.push((aggregated_soonest, aggregated_claim));
717 // Generate claim transactions and track them to bump if necessary at
718 // height timer expiration (i.e in how many blocks we're going to take action).
719 for (soonest_timelock, claim) in new_claims.drain(..) {
720 let mut claim_material = ClaimTxBumpMaterial { height_timer: None, feerate_previous: 0, soonest_timelock, per_input_material: claim };
721 if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
722 claim_material.height_timer = new_timer;
723 claim_material.feerate_previous = new_feerate;
724 let txid = tx.txid();
725 for k in claim_material.per_input_material.keys() {
726 log_trace!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
727 self.claimable_outpoints.insert(k.clone(), (txid, height));
729 self.pending_claim_requests.insert(txid, claim_material);
730 log_trace!(logger, "Broadcast onchain {}", log_tx!(tx));
731 broadcaster.broadcast_transaction(&tx);
735 let mut bump_candidates = HashMap::new();
736 for tx in txn_matched {
737 // Scan all input to verify is one of the outpoint spent is of interest for us
738 let mut claimed_outputs_material = Vec::new();
739 for inp in &tx.input {
740 if let Some(first_claim_txid_height) = self.claimable_outpoints.get(&inp.previous_output) {
741 // If outpoint has claim request pending on it...
742 if let Some(claim_material) = self.pending_claim_requests.get_mut(&first_claim_txid_height.0) {
743 //... we need to verify equality between transaction outpoints and claim request
744 // outpoints to know if transaction is the original claim or a bumped one issued
746 let mut set_equality = true;
747 if claim_material.per_input_material.len() != tx.input.len() {
748 set_equality = false;
750 for (claim_inp, tx_inp) in claim_material.per_input_material.keys().zip(tx.input.iter()) {
751 if *claim_inp != tx_inp.previous_output {
752 set_equality = false;
757 macro_rules! clean_claim_request_after_safety_delay {
759 let new_event = OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() };
760 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
761 hash_map::Entry::Occupied(mut entry) => {
762 if !entry.get().contains(&new_event) {
763 entry.get_mut().push(new_event);
766 hash_map::Entry::Vacant(entry) => {
767 entry.insert(vec![new_event]);
773 // If this is our transaction (or our counterparty spent all the outputs
774 // before we could anyway with same inputs order than us), wait for
775 // ANTI_REORG_DELAY and clean the RBF tracking map.
777 clean_claim_request_after_safety_delay!();
778 } else { // If false, generate new claim request with update outpoint set
779 let mut at_least_one_drop = false;
780 for input in tx.input.iter() {
781 if let Some(input_material) = claim_material.per_input_material.remove(&input.previous_output) {
782 claimed_outputs_material.push((input.previous_output, input_material));
783 at_least_one_drop = true;
785 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
786 if claim_material.per_input_material.is_empty() {
787 clean_claim_request_after_safety_delay!();
790 //TODO: recompute soonest_timelock to avoid wasting a bit on fees
791 if at_least_one_drop {
792 bump_candidates.insert(first_claim_txid_height.0.clone(), claim_material.clone());
795 break; //No need to iterate further, either tx is our or their
797 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
801 for (outpoint, input_material) in claimed_outputs_material.drain(..) {
802 let new_event = OnchainEvent::ContentiousOutpoint { outpoint, input_material };
803 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
804 hash_map::Entry::Occupied(mut entry) => {
805 if !entry.get().contains(&new_event) {
806 entry.get_mut().push(new_event);
809 hash_map::Entry::Vacant(entry) => {
810 entry.insert(vec![new_event]);
816 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
817 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
820 OnchainEvent::Claim { claim_request } => {
821 // We may remove a whole set of claim outpoints here, as these one may have
822 // been aggregated in a single tx and claimed so atomically
823 if let Some(bump_material) = self.pending_claim_requests.remove(&claim_request) {
824 for outpoint in bump_material.per_input_material.keys() {
825 self.claimable_outpoints.remove(&outpoint);
829 OnchainEvent::ContentiousOutpoint { outpoint, .. } => {
830 self.claimable_outpoints.remove(&outpoint);
836 // Check if any pending claim request must be rescheduled
837 for (first_claim_txid, ref claim_data) in self.pending_claim_requests.iter() {
838 if let Some(h) = claim_data.height_timer {
840 bump_candidates.insert(*first_claim_txid, (*claim_data).clone());
845 // Build, bump and rebroadcast tx accordingly
846 log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
847 for (first_claim_txid, claim_material) in bump_candidates.iter() {
848 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
849 log_trace!(logger, "Broadcast onchain {}", log_tx!(bump_tx));
850 broadcaster.broadcast_transaction(&bump_tx);
851 if let Some(claim_material) = self.pending_claim_requests.get_mut(first_claim_txid) {
852 claim_material.height_timer = new_timer;
853 claim_material.feerate_previous = new_feerate;
859 pub(crate) fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: F, logger: L)
860 where B::Target: BroadcasterInterface,
861 F::Target: FeeEstimator,
864 let mut bump_candidates = HashMap::new();
865 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
866 //- our claim tx on a commitment tx output
867 //- resurect outpoint back in its claimable set and regenerate tx
870 OnchainEvent::ContentiousOutpoint { outpoint, input_material } => {
871 if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&outpoint) {
872 if let Some(claim_material) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) {
873 claim_material.per_input_material.insert(outpoint, input_material);
874 // Using a HashMap guarantee us than if we have multiple outpoints getting
875 // resurrected only one bump claim tx is going to be broadcast
876 bump_candidates.insert(ancestor_claimable_txid.clone(), claim_material.clone());
884 for (_, claim_material) in bump_candidates.iter_mut() {
885 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &&*fee_estimator, &&*logger) {
886 claim_material.height_timer = new_timer;
887 claim_material.feerate_previous = new_feerate;
888 broadcaster.broadcast_transaction(&bump_tx);
891 for (ancestor_claim_txid, claim_material) in bump_candidates.drain() {
892 self.pending_claim_requests.insert(ancestor_claim_txid.0, claim_material);
894 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
895 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
896 let mut remove_request = Vec::new();
897 self.claimable_outpoints.retain(|_, ref v|
899 remove_request.push(v.0.clone());
902 for req in remove_request {
903 self.pending_claim_requests.remove(&req);
907 pub(crate) fn provide_latest_holder_tx(&mut self, tx: HolderCommitmentTransaction) {
908 self.prev_holder_commitment = Some(replace(&mut self.holder_commitment, tx));
909 self.holder_htlc_sigs = None;
912 // Normally holder HTLCs are signed at the same time as the holder commitment tx. However,
913 // in some configurations, the holder commitment tx has been signed and broadcast by a
914 // ChannelMonitor replica, so we handle that case here.
915 fn sign_latest_holder_htlcs(&mut self) {
916 if self.holder_htlc_sigs.is_none() {
917 let (_sig, sigs) = self.key_storage.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
918 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, sigs));
922 // Normally only the latest commitment tx and HTLCs need to be signed. However, in some
923 // configurations we may have updated our holder commitment but a replica of the ChannelMonitor
924 // broadcast the previous one before we sync with it. We handle that case here.
925 fn sign_prev_holder_htlcs(&mut self) {
926 if self.prev_holder_htlc_sigs.is_none() {
927 if let Some(ref holder_commitment) = self.prev_holder_commitment {
928 let (_sig, sigs) = self.key_storage.sign_holder_commitment_and_htlcs(holder_commitment, &self.secp_ctx).expect("sign previous holder commitment");
929 self.prev_holder_htlc_sigs = Some(Self::extract_holder_sigs(holder_commitment, sigs));
934 fn extract_holder_sigs(holder_commitment: &HolderCommitmentTransaction, sigs: Vec<Signature>) -> Vec<Option<(usize, Signature)>> {
935 let mut ret = Vec::new();
936 for (htlc_idx, (holder_sig, htlc)) in sigs.iter().zip(holder_commitment.htlcs().iter()).enumerate() {
937 let tx_idx = htlc.transaction_output_index.unwrap();
938 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
939 ret[tx_idx as usize] = Some((htlc_idx, holder_sig.clone()));
944 //TODO: getting lastest holder transactions should be infallible and result in us "force-closing the channel", but we may
945 // have empty holder commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
946 // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
947 // to monitor before.
948 pub(crate) fn get_fully_signed_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
949 let (sig, htlc_sigs) = self.key_storage.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("signing holder commitment");
950 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
951 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
954 #[cfg(any(test, feature="unsafe_revoked_tx_signing"))]
955 pub(crate) fn get_fully_signed_copy_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
956 let (sig, htlc_sigs) = self.key_storage.unsafe_sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
957 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
958 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
961 pub(crate) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
962 let mut htlc_tx = None;
963 let commitment_txid = self.holder_commitment.trust().txid();
964 // Check if the HTLC spends from the current holder commitment
965 if commitment_txid == outp.txid {
966 self.sign_latest_holder_htlcs();
967 if let &Some(ref htlc_sigs) = &self.holder_htlc_sigs {
968 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
969 let trusted_tx = self.holder_commitment.trust();
970 let counterparty_htlc_sig = self.holder_commitment.counterparty_htlc_sigs[*htlc_idx];
971 htlc_tx = Some(trusted_tx
972 .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
975 // If the HTLC doesn't spend the current holder commitment, check if it spends the previous one
976 if htlc_tx.is_none() && self.prev_holder_commitment.is_some() {
977 let commitment_txid = self.prev_holder_commitment.as_ref().unwrap().trust().txid();
978 if commitment_txid == outp.txid {
979 self.sign_prev_holder_htlcs();
980 if let &Some(ref htlc_sigs) = &self.prev_holder_htlc_sigs {
981 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
982 let holder_commitment = self.prev_holder_commitment.as_ref().unwrap();
983 let trusted_tx = holder_commitment.trust();
984 let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[*htlc_idx];
985 htlc_tx = Some(trusted_tx
986 .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
993 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
994 pub(crate) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
995 let latest_had_sigs = self.holder_htlc_sigs.is_some();
996 let prev_had_sigs = self.prev_holder_htlc_sigs.is_some();
997 let ret = self.get_fully_signed_htlc_tx(outp, preimage);
998 if !latest_had_sigs {
999 self.holder_htlc_sigs = None;
1002 self.prev_holder_htlc_sigs = None;