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::{Sign, KeysInterface};
31 use util::logger::Logger;
32 use util::ser::{Readable, ReadableArgs, Writer, Writeable, VecWriter};
35 use std::collections::HashMap;
38 use std::mem::replace;
40 const MAX_ALLOC_SIZE: usize = 64*1024;
42 /// An entry for an [`OnchainEvent`], stating the block height when the event was observed.
44 /// Used to determine when the on-chain event can be considered safe from a chain reorganization.
46 struct OnchainEventEntry {
51 impl OnchainEventEntry {
52 fn confirmation_threshold(&self) -> u32 {
53 self.height + ANTI_REORG_DELAY - 1
56 fn has_reached_confirmation_threshold(&self, height: u32) -> bool {
57 height >= self.confirmation_threshold()
61 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
62 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
65 /// Outpoint under claim process by our own tx, once this one get enough confirmations, we remove it from
66 /// bump-txn candidate buffer.
70 /// Claim tx aggregate multiple claimable outpoints. One of the outpoint may be claimed by a counterparty party tx.
71 /// In this case, we need to drop the outpoint and regenerate a new claim tx. By safety, we keep tracking
72 /// the outpoint to be sure to resurect it back to the claim tx if reorgs happen.
74 outpoint: BitcoinOutPoint,
75 input_material: InputMaterial,
79 /// Higher-level cache structure needed to re-generate bumped claim txn if needed
80 #[derive(Clone, PartialEq)]
81 pub struct ClaimTxBumpMaterial {
82 // At every block tick, used to check if pending claiming tx is taking too
83 // much time for confirmation and we need to bump it.
84 height_timer: Option<u32>,
85 // Tracked in case of reorg to wipe out now-superflous bump material
86 feerate_previous: u32,
87 // Soonest timelocks among set of outpoints claimed, used to compute
88 // a priority of not feerate
89 soonest_timelock: u32,
90 // Cache of script, pubkey, sig or key to solve claimable outputs scriptpubkey.
91 per_input_material: HashMap<BitcoinOutPoint, InputMaterial>,
94 impl Writeable for ClaimTxBumpMaterial {
95 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
96 self.height_timer.write(writer)?;
97 writer.write_all(&byte_utils::be32_to_array(self.feerate_previous))?;
98 writer.write_all(&byte_utils::be32_to_array(self.soonest_timelock))?;
99 writer.write_all(&byte_utils::be64_to_array(self.per_input_material.len() as u64))?;
100 for (outp, tx_material) in self.per_input_material.iter() {
102 tx_material.write(writer)?;
108 impl Readable for ClaimTxBumpMaterial {
109 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
110 let height_timer = Readable::read(reader)?;
111 let feerate_previous = Readable::read(reader)?;
112 let soonest_timelock = Readable::read(reader)?;
113 let per_input_material_len: u64 = Readable::read(reader)?;
114 let mut per_input_material = HashMap::with_capacity(cmp::min(per_input_material_len as usize, MAX_ALLOC_SIZE / 128));
115 for _ in 0 ..per_input_material_len {
116 let outpoint = Readable::read(reader)?;
117 let input_material = Readable::read(reader)?;
118 per_input_material.insert(outpoint, input_material);
120 Ok(Self { height_timer, feerate_previous, soonest_timelock, per_input_material })
124 #[derive(PartialEq, Clone, Copy)]
125 pub(crate) enum InputDescriptors {
130 RevokedOutput, // either a revoked to_holder output on commitment tx, a revoked HTLC-Timeout output or a revoked HTLC-Success output
133 impl Writeable for InputDescriptors {
134 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
136 &InputDescriptors::RevokedOfferedHTLC => {
137 writer.write_all(&[0; 1])?;
139 &InputDescriptors::RevokedReceivedHTLC => {
140 writer.write_all(&[1; 1])?;
142 &InputDescriptors::OfferedHTLC => {
143 writer.write_all(&[2; 1])?;
145 &InputDescriptors::ReceivedHTLC => {
146 writer.write_all(&[3; 1])?;
148 &InputDescriptors::RevokedOutput => {
149 writer.write_all(&[4; 1])?;
156 impl Readable for InputDescriptors {
157 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
158 let input_descriptor = match <u8 as Readable>::read(reader)? {
160 InputDescriptors::RevokedOfferedHTLC
163 InputDescriptors::RevokedReceivedHTLC
166 InputDescriptors::OfferedHTLC
169 InputDescriptors::ReceivedHTLC
172 InputDescriptors::RevokedOutput
174 _ => return Err(DecodeError::InvalidValue),
180 macro_rules! subtract_high_prio_fee {
181 ($logger: ident, $fee_estimator: expr, $value: expr, $predicted_weight: expr, $used_feerate: expr) => {
183 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority).into();
184 let mut fee = $used_feerate as u64 * $predicted_weight / 1000;
186 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal).into();
187 fee = $used_feerate as u64 * $predicted_weight / 1000;
188 if $value <= fee.into() {
189 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background).into();
190 fee = $used_feerate as u64 * $predicted_weight / 1000;
192 log_error!($logger, "Failed to generate an on-chain punishment tx as even low priority fee ({} sat) was more than the entire claim balance ({} sat)",
196 log_warn!($logger, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
202 log_warn!($logger, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
215 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
216 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
217 match Readable::read(reader)? {
220 let vlen: u64 = Readable::read(reader)?;
221 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<Option<(usize, Signature)>>()));
223 ret.push(match Readable::read(reader)? {
225 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
226 _ => return Err(DecodeError::InvalidValue)
231 _ => Err(DecodeError::InvalidValue),
236 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
237 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
241 (vec.len() as u64).write(writer)?;
242 for opt in vec.iter() {
244 &Some((ref idx, ref sig)) => {
246 (*idx as u64).write(writer)?;
249 &None => 0u8.write(writer)?,
253 &None => 0u8.write(writer)?,
260 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
261 /// do RBF bumping if possible.
262 pub struct OnchainTxHandler<ChannelSigner: Sign> {
263 destination_script: Script,
264 holder_commitment: HolderCommitmentTransaction,
265 // holder_htlc_sigs and prev_holder_htlc_sigs are in the order as they appear in the commitment
266 // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
267 // the set of HTLCs in the HolderCommitmentTransaction.
268 holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
269 prev_holder_commitment: Option<HolderCommitmentTransaction>,
270 prev_holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
272 signer: ChannelSigner,
273 pub(crate) channel_transaction_parameters: ChannelTransactionParameters,
275 // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
276 // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
277 // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
278 // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
279 // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
280 // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
281 // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
282 // we need to regenerate new claim request with reduced set of still-claimable outpoints.
283 // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
284 // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
285 // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
286 #[cfg(test)] // Used in functional_test to verify sanitization
287 pub pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
289 pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
291 // Used to link outpoints claimed in a connected block to a pending claim request.
292 // Key is outpoint than monitor parsing has detected we have keys/scripts to claim
293 // Value is (pending claim request identifier, confirmation_block), identifier
294 // is txid of the initial claiming transaction and is immutable until outpoint is
295 // post-anti-reorg-delay solved, confirmaiton_block is used to erase entry if
296 // block with output gets disconnected.
297 #[cfg(test)] // Used in functional_test to verify sanitization
298 pub claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
300 claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
302 onchain_events_waiting_threshold_conf: Vec<OnchainEventEntry>,
306 secp_ctx: Secp256k1<secp256k1::All>,
309 impl<ChannelSigner: Sign> OnchainTxHandler<ChannelSigner> {
310 pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
311 self.destination_script.write(writer)?;
312 self.holder_commitment.write(writer)?;
313 self.holder_htlc_sigs.write(writer)?;
314 self.prev_holder_commitment.write(writer)?;
315 self.prev_holder_htlc_sigs.write(writer)?;
317 self.channel_transaction_parameters.write(writer)?;
319 let mut key_data = VecWriter(Vec::new());
320 self.signer.write(&mut key_data)?;
321 assert!(key_data.0.len() < std::usize::MAX);
322 assert!(key_data.0.len() < std::u32::MAX as usize);
323 (key_data.0.len() as u32).write(writer)?;
324 writer.write_all(&key_data.0[..])?;
326 writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
327 for (ref ancestor_claim_txid, claim_tx_data) in self.pending_claim_requests.iter() {
328 ancestor_claim_txid.write(writer)?;
329 claim_tx_data.write(writer)?;
332 writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
333 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
335 claim_and_height.0.write(writer)?;
336 claim_and_height.1.write(writer)?;
339 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
340 for ref entry in self.onchain_events_waiting_threshold_conf.iter() {
341 writer.write_all(&byte_utils::be32_to_array(entry.height))?;
343 OnchainEvent::Claim { ref claim_request } => {
344 writer.write_all(&[0; 1])?;
345 claim_request.write(writer)?;
347 OnchainEvent::ContentiousOutpoint { ref outpoint, ref input_material } => {
348 writer.write_all(&[1; 1])?;
349 outpoint.write(writer)?;
350 input_material.write(writer)?;
354 self.latest_height.write(writer)?;
359 impl<'a, K: KeysInterface> ReadableArgs<&'a K> for OnchainTxHandler<K::Signer> {
360 fn read<R: ::std::io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
361 let destination_script = Readable::read(reader)?;
363 let holder_commitment = Readable::read(reader)?;
364 let holder_htlc_sigs = Readable::read(reader)?;
365 let prev_holder_commitment = Readable::read(reader)?;
366 let prev_holder_htlc_sigs = Readable::read(reader)?;
368 let channel_parameters = Readable::read(reader)?;
370 let keys_len: u32 = Readable::read(reader)?;
371 let mut keys_data = Vec::with_capacity(cmp::min(keys_len as usize, MAX_ALLOC_SIZE));
372 while keys_data.len() != keys_len as usize {
373 // Read 1KB at a time to avoid accidentally allocating 4GB on corrupted channel keys
374 let mut data = [0; 1024];
375 let read_slice = &mut data[0..cmp::min(1024, keys_len as usize - keys_data.len())];
376 reader.read_exact(read_slice)?;
377 keys_data.extend_from_slice(read_slice);
379 let signer = keys_manager.read_chan_signer(&keys_data)?;
381 let pending_claim_requests_len: u64 = Readable::read(reader)?;
382 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
383 for _ in 0..pending_claim_requests_len {
384 pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
387 let claimable_outpoints_len: u64 = Readable::read(reader)?;
388 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
389 for _ in 0..claimable_outpoints_len {
390 let outpoint = Readable::read(reader)?;
391 let ancestor_claim_txid = Readable::read(reader)?;
392 let height = Readable::read(reader)?;
393 claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
395 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
396 let mut onchain_events_waiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
397 for _ in 0..waiting_threshold_conf_len {
398 let height = Readable::read(reader)?;
399 let event = match <u8 as Readable>::read(reader)? {
401 let claim_request = Readable::read(reader)?;
402 OnchainEvent::Claim {
407 let outpoint = Readable::read(reader)?;
408 let input_material = Readable::read(reader)?;
409 OnchainEvent::ContentiousOutpoint {
414 _ => return Err(DecodeError::InvalidValue),
416 onchain_events_waiting_threshold_conf.push(OnchainEventEntry { height, event });
418 let latest_height = Readable::read(reader)?;
420 let mut secp_ctx = Secp256k1::new();
421 secp_ctx.seeded_randomize(&keys_manager.get_secure_random_bytes());
423 Ok(OnchainTxHandler {
427 prev_holder_commitment,
428 prev_holder_htlc_sigs,
430 channel_transaction_parameters: channel_parameters,
432 pending_claim_requests,
433 onchain_events_waiting_threshold_conf,
440 impl<ChannelSigner: Sign> OnchainTxHandler<ChannelSigner> {
441 pub(crate) fn new(destination_script: Script, signer: ChannelSigner, channel_parameters: ChannelTransactionParameters, holder_commitment: HolderCommitmentTransaction, secp_ctx: Secp256k1<secp256k1::All>) -> Self {
445 holder_htlc_sigs: None,
446 prev_holder_commitment: None,
447 prev_holder_htlc_sigs: None,
449 channel_transaction_parameters: channel_parameters,
450 pending_claim_requests: HashMap::new(),
451 claimable_outpoints: HashMap::new(),
452 onchain_events_waiting_threshold_conf: Vec::new(),
459 pub(crate) fn get_witnesses_weight(inputs: &[InputDescriptors]) -> usize {
460 let mut tx_weight = 2; // count segwit flags
462 // We use expected weight (and not actual) as signatures and time lock delays may vary
463 tx_weight += match inp {
464 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
465 &InputDescriptors::RevokedOfferedHTLC => {
466 1 + 1 + 73 + 1 + 33 + 1 + 133
468 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
469 &InputDescriptors::RevokedReceivedHTLC => {
470 1 + 1 + 73 + 1 + 33 + 1 + 139
472 // number_of_witness_elements + sig_length + counterpartyhtlc_sig + preimage_length + preimage + witness_script_length + witness_script
473 &InputDescriptors::OfferedHTLC => {
474 1 + 1 + 73 + 1 + 32 + 1 + 133
476 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
477 &InputDescriptors::ReceivedHTLC => {
478 1 + 1 + 73 + 1 + 1 + 1 + 139
480 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
481 &InputDescriptors::RevokedOutput => {
482 1 + 1 + 73 + 1 + 1 + 1 + 77
489 /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
490 /// 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
491 /// height than once reached we should generate a new bumped "version" of the claim tx to be sure than we safely claim outputs before
492 /// than our counterparty can do it too. If timelock expires soon, height timer is going to be scale down in consequence to increase
493 /// frequency of the bump and so increase our bets of success.
494 fn get_height_timer(current_height: u32, timelock_expiration: u32) -> u32 {
495 if timelock_expiration <= current_height + 3 {
496 return current_height + 1
497 } else if timelock_expiration - current_height <= 15 {
498 return current_height + 3
503 /// 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
504 /// (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.
505 /// Panics if there are signing errors, because signing operations in reaction to on-chain events
506 /// are not expected to fail, and if they do, we may lose funds.
507 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)>
508 where F::Target: FeeEstimator,
511 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
512 let mut inputs = Vec::new();
513 for outp in cached_claim_datas.per_input_material.keys() {
514 log_trace!(logger, "Outpoint {}:{}", outp.txid, outp.vout);
516 previous_output: *outp,
517 script_sig: Script::new(),
518 sequence: 0xfffffffd,
522 let mut bumped_tx = Transaction {
527 script_pubkey: self.destination_script.clone(),
532 macro_rules! RBF_bump {
533 ($amount: expr, $old_feerate: expr, $fee_estimator: expr, $predicted_weight: expr) => {
535 let mut used_feerate: u32;
536 // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
537 let new_fee = if $old_feerate < $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) {
538 let mut value = $amount;
539 if subtract_high_prio_fee!(logger, $fee_estimator, value, $predicted_weight, used_feerate) {
540 // Overflow check is done in subtract_high_prio_fee
543 log_trace!(logger, "Can't new-estimation bump new claiming tx, amount {} is too small", $amount);
546 // ...else just increase the previous feerate by 25% (because that's a nice number)
548 let fee = $old_feerate as u64 * ($predicted_weight as u64) / 750;
550 log_trace!(logger, "Can't 25% bump new claiming tx, amount {} is too small", $amount);
556 let previous_fee = $old_feerate as u64 * ($predicted_weight as u64) / 1000;
557 let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * ($predicted_weight as u64) / 1000;
558 // BIP 125 Opt-in Full Replace-by-Fee Signaling
559 // * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
560 // * 4. The replacement transaction must also pay for its own bandwidth at or above the rate set by the node's minimum relay fee setting.
561 let new_fee = if new_fee < previous_fee + min_relay_fee {
562 new_fee + previous_fee + min_relay_fee - new_fee
566 Some((new_fee, new_fee * 1000 / ($predicted_weight as u64)))
571 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
572 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
573 let new_timer = Some(Self::get_height_timer(height, cached_claim_datas.soonest_timelock));
574 let mut inputs_witnesses_weight = 0;
576 let mut dynamic_fee = true;
577 for per_outp_material in cached_claim_datas.per_input_material.values() {
578 match per_outp_material {
579 &InputMaterial::Revoked { ref input_descriptor, ref amount, .. } => {
580 inputs_witnesses_weight += Self::get_witnesses_weight(&[*input_descriptor]);
583 &InputMaterial::CounterpartyHTLC { ref preimage, ref htlc, .. } => {
584 inputs_witnesses_weight += Self::get_witnesses_weight(if preimage.is_some() { &[InputDescriptors::OfferedHTLC] } else { &[InputDescriptors::ReceivedHTLC] });
585 amt += htlc.amount_msat / 1000;
587 &InputMaterial::HolderHTLC { .. } => {
590 &InputMaterial::Funding { .. } => {
596 let predicted_weight = (bumped_tx.get_weight() + inputs_witnesses_weight) as u64;
598 // If old feerate is 0, first iteration of this claim, use normal fee calculation
599 if cached_claim_datas.feerate_previous != 0 {
600 if let Some((new_fee, feerate)) = RBF_bump!(amt, cached_claim_datas.feerate_previous, fee_estimator, predicted_weight) {
601 // If new computed fee is superior at the whole claimable amount burn all in fees
602 if new_fee as u64 > amt {
603 bumped_tx.output[0].value = 0;
605 bumped_tx.output[0].value = amt - new_fee as u64;
607 new_feerate = feerate;
608 } else { return None; }
610 if subtract_high_prio_fee!(logger, fee_estimator, amt, predicted_weight, new_feerate) {
611 bumped_tx.output[0].value = amt;
612 } else { return None; }
614 assert!(new_feerate != 0);
616 for (i, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
617 match per_outp_material {
618 &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 } => {
619 if let Ok(tx_keys) = TxCreationKeys::derive_new(&self.secp_ctx, &per_commitment_point, counterparty_delayed_payment_base_key, counterparty_htlc_base_key, &self.signer.pubkeys().revocation_basepoint, &self.signer.pubkeys().htlc_basepoint) {
621 let witness_script = if let Some(ref htlc) = *htlc {
622 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &tx_keys.broadcaster_htlc_key, &tx_keys.countersignatory_htlc_key, &tx_keys.revocation_key)
624 chan_utils::get_revokeable_redeemscript(&tx_keys.revocation_key, *on_counterparty_tx_csv, &tx_keys.broadcaster_delayed_payment_key)
627 let sig = self.signer.sign_justice_transaction(&bumped_tx, i, *amount, &per_commitment_key, htlc, &self.secp_ctx).expect("sign justice tx");
628 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
629 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
631 bumped_tx.input[i].witness.push(tx_keys.revocation_key.clone().serialize().to_vec());
633 bumped_tx.input[i].witness.push(vec!(1));
635 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
637 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);
640 &InputMaterial::CounterpartyHTLC { ref per_commitment_point, ref counterparty_delayed_payment_base_key, ref counterparty_htlc_base_key, ref preimage, ref htlc } => {
641 if let Ok(tx_keys) = TxCreationKeys::derive_new(&self.secp_ctx, &per_commitment_point, counterparty_delayed_payment_base_key, counterparty_htlc_base_key, &self.signer.pubkeys().revocation_basepoint, &self.signer.pubkeys().htlc_basepoint) {
642 let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &tx_keys.broadcaster_htlc_key, &tx_keys.countersignatory_htlc_key, &tx_keys.revocation_key);
644 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
645 let sig = self.signer.sign_counterparty_htlc_transaction(&bumped_tx, i, &htlc.amount_msat / 1000, &per_commitment_point, htlc, &self.secp_ctx).expect("sign counterparty HTLC tx");
646 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
647 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
648 if let &Some(preimage) = preimage {
649 bumped_tx.input[i].witness.push(preimage.0.to_vec());
651 // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
652 bumped_tx.input[i].witness.push(vec![]);
654 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
655 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);
661 log_trace!(logger, "...with timer {}", new_timer.unwrap());
662 assert!(predicted_weight >= bumped_tx.get_weight() as u64);
663 return Some((new_timer, new_feerate as u32, bumped_tx))
665 for (_, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
666 match per_outp_material {
667 &InputMaterial::HolderHTLC { ref preimage, ref amount } => {
668 let htlc_tx = self.get_fully_signed_htlc_tx(outp, preimage);
669 if let Some(htlc_tx) = htlc_tx {
670 let feerate = (amount - htlc_tx.output[0].value) * 1000 / htlc_tx.get_weight() as u64;
671 // Timer set to $NEVER given we can't bump tx without anchor outputs
672 log_trace!(logger, "Going to broadcast Holder HTLC-{} claiming HTLC output {} from {}...", if preimage.is_some() { "Success" } else { "Timeout" }, outp.vout, outp.txid);
673 return Some((None, feerate as u32, htlc_tx));
677 &InputMaterial::Funding { ref funding_redeemscript } => {
678 let signed_tx = self.get_fully_signed_holder_tx(funding_redeemscript);
679 // Timer set to $NEVER given we can't bump tx without anchor outputs
680 log_trace!(logger, "Going to broadcast Holder Transaction {} claiming funding output {} from {}...", signed_tx.txid(), outp.vout, outp.txid);
681 return Some((None, self.holder_commitment.feerate_per_kw(), signed_tx));
690 /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
691 /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
692 /// Formerly this was named `block_connected`, but it is now also used for claiming an HTLC output
693 /// if we receive a preimage after force-close.
694 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)
695 where B::Target: BroadcasterInterface,
696 F::Target: FeeEstimator,
699 let height = match latest_height {
701 None => self.latest_height,
703 log_trace!(logger, "Updating claims view at height {} with {} matched transactions and {} claim requests", height, txn_matched.len(), claimable_outpoints.len());
704 let mut new_claims = Vec::new();
705 let mut aggregated_claim = HashMap::new();
706 let mut aggregated_soonest = ::std::u32::MAX;
708 // Try to aggregate outputs if their timelock expiration isn't imminent (absolute_timelock
709 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
710 for req in claimable_outpoints {
711 // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
712 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 {
713 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.absolute_timelock, height + CLTV_SHARED_CLAIM_BUFFER);
714 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
715 let mut single_input = HashMap::new();
716 single_input.insert(req.outpoint, req.witness_data);
717 new_claims.push((req.absolute_timelock, single_input));
719 aggregated_claim.insert(req.outpoint, req.witness_data);
720 if req.absolute_timelock < aggregated_soonest {
721 aggregated_soonest = req.absolute_timelock;
726 new_claims.push((aggregated_soonest, aggregated_claim));
728 // Generate claim transactions and track them to bump if necessary at
729 // height timer expiration (i.e in how many blocks we're going to take action).
730 for (soonest_timelock, claim) in new_claims.drain(..) {
731 let mut claim_material = ClaimTxBumpMaterial { height_timer: None, feerate_previous: 0, soonest_timelock, per_input_material: claim };
732 if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
733 claim_material.height_timer = new_timer;
734 claim_material.feerate_previous = new_feerate;
735 let txid = tx.txid();
736 for k in claim_material.per_input_material.keys() {
737 log_trace!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
738 self.claimable_outpoints.insert(k.clone(), (txid, height));
740 self.pending_claim_requests.insert(txid, claim_material);
741 log_trace!(logger, "Broadcast onchain {}", log_tx!(tx));
742 broadcaster.broadcast_transaction(&tx);
746 let mut bump_candidates = HashMap::new();
747 for tx in txn_matched {
748 // Scan all input to verify is one of the outpoint spent is of interest for us
749 let mut claimed_outputs_material = Vec::new();
750 for inp in &tx.input {
751 if let Some(first_claim_txid_height) = self.claimable_outpoints.get(&inp.previous_output) {
752 // If outpoint has claim request pending on it...
753 if let Some(claim_material) = self.pending_claim_requests.get_mut(&first_claim_txid_height.0) {
754 //... we need to verify equality between transaction outpoints and claim request
755 // outpoints to know if transaction is the original claim or a bumped one issued
757 let mut set_equality = true;
758 if claim_material.per_input_material.len() != tx.input.len() {
759 set_equality = false;
761 for (claim_inp, tx_inp) in claim_material.per_input_material.keys().zip(tx.input.iter()) {
762 if *claim_inp != tx_inp.previous_output {
763 set_equality = false;
768 macro_rules! clean_claim_request_after_safety_delay {
770 let entry = OnchainEventEntry {
772 event: OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() }
774 if !self.onchain_events_waiting_threshold_conf.contains(&entry) {
775 self.onchain_events_waiting_threshold_conf.push(entry);
780 // If this is our transaction (or our counterparty spent all the outputs
781 // before we could anyway with same inputs order than us), wait for
782 // ANTI_REORG_DELAY and clean the RBF tracking map.
784 clean_claim_request_after_safety_delay!();
785 } else { // If false, generate new claim request with update outpoint set
786 let mut at_least_one_drop = false;
787 for input in tx.input.iter() {
788 if let Some(input_material) = claim_material.per_input_material.remove(&input.previous_output) {
789 claimed_outputs_material.push((input.previous_output, input_material));
790 at_least_one_drop = true;
792 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
793 if claim_material.per_input_material.is_empty() {
794 clean_claim_request_after_safety_delay!();
797 //TODO: recompute soonest_timelock to avoid wasting a bit on fees
798 if at_least_one_drop {
799 bump_candidates.insert(first_claim_txid_height.0.clone(), claim_material.clone());
802 break; //No need to iterate further, either tx is our or their
804 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
808 for (outpoint, input_material) in claimed_outputs_material.drain(..) {
809 let entry = OnchainEventEntry {
811 event: OnchainEvent::ContentiousOutpoint { outpoint, input_material },
813 if !self.onchain_events_waiting_threshold_conf.contains(&entry) {
814 self.onchain_events_waiting_threshold_conf.push(entry);
819 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
820 let onchain_events_waiting_threshold_conf =
821 self.onchain_events_waiting_threshold_conf.drain(..).collect::<Vec<_>>();
822 for entry in onchain_events_waiting_threshold_conf {
823 if entry.has_reached_confirmation_threshold(height) {
825 OnchainEvent::Claim { claim_request } => {
826 // We may remove a whole set of claim outpoints here, as these one may have
827 // been aggregated in a single tx and claimed so atomically
828 if let Some(bump_material) = self.pending_claim_requests.remove(&claim_request) {
829 for outpoint in bump_material.per_input_material.keys() {
830 self.claimable_outpoints.remove(&outpoint);
834 OnchainEvent::ContentiousOutpoint { outpoint, .. } => {
835 self.claimable_outpoints.remove(&outpoint);
839 self.onchain_events_waiting_threshold_conf.push(entry);
843 // Check if any pending claim request must be rescheduled
844 for (first_claim_txid, ref claim_data) in self.pending_claim_requests.iter() {
845 if let Some(h) = claim_data.height_timer {
847 bump_candidates.insert(*first_claim_txid, (*claim_data).clone());
852 // Build, bump and rebroadcast tx accordingly
853 log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
854 for (first_claim_txid, claim_material) in bump_candidates.iter() {
855 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
856 log_trace!(logger, "Broadcast onchain {}", log_tx!(bump_tx));
857 broadcaster.broadcast_transaction(&bump_tx);
858 if let Some(claim_material) = self.pending_claim_requests.get_mut(first_claim_txid) {
859 claim_material.height_timer = new_timer;
860 claim_material.feerate_previous = new_feerate;
866 pub(crate) fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: F, logger: L)
867 where B::Target: BroadcasterInterface,
868 F::Target: FeeEstimator,
871 let mut bump_candidates = HashMap::new();
872 let onchain_events_waiting_threshold_conf =
873 self.onchain_events_waiting_threshold_conf.drain(..).collect::<Vec<_>>();
874 for entry in onchain_events_waiting_threshold_conf {
875 if entry.height == height {
876 //- our claim tx on a commitment tx output
877 //- resurect outpoint back in its claimable set and regenerate tx
879 OnchainEvent::ContentiousOutpoint { outpoint, input_material } => {
880 if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&outpoint) {
881 if let Some(claim_material) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) {
882 claim_material.per_input_material.insert(outpoint, input_material);
883 // Using a HashMap guarantee us than if we have multiple outpoints getting
884 // resurrected only one bump claim tx is going to be broadcast
885 bump_candidates.insert(ancestor_claimable_txid.clone(), claim_material.clone());
892 self.onchain_events_waiting_threshold_conf.push(entry);
895 for (_, claim_material) in bump_candidates.iter_mut() {
896 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &&*fee_estimator, &&*logger) {
897 claim_material.height_timer = new_timer;
898 claim_material.feerate_previous = new_feerate;
899 broadcaster.broadcast_transaction(&bump_tx);
902 for (ancestor_claim_txid, claim_material) in bump_candidates.drain() {
903 self.pending_claim_requests.insert(ancestor_claim_txid.0, claim_material);
905 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
906 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
907 let mut remove_request = Vec::new();
908 self.claimable_outpoints.retain(|_, ref v|
910 remove_request.push(v.0.clone());
913 for req in remove_request {
914 self.pending_claim_requests.remove(&req);
918 pub(crate) fn provide_latest_holder_tx(&mut self, tx: HolderCommitmentTransaction) {
919 self.prev_holder_commitment = Some(replace(&mut self.holder_commitment, tx));
920 self.holder_htlc_sigs = None;
923 // Normally holder HTLCs are signed at the same time as the holder commitment tx. However,
924 // in some configurations, the holder commitment tx has been signed and broadcast by a
925 // ChannelMonitor replica, so we handle that case here.
926 fn sign_latest_holder_htlcs(&mut self) {
927 if self.holder_htlc_sigs.is_none() {
928 let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
929 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, sigs));
933 // Normally only the latest commitment tx and HTLCs need to be signed. However, in some
934 // configurations we may have updated our holder commitment but a replica of the ChannelMonitor
935 // broadcast the previous one before we sync with it. We handle that case here.
936 fn sign_prev_holder_htlcs(&mut self) {
937 if self.prev_holder_htlc_sigs.is_none() {
938 if let Some(ref holder_commitment) = self.prev_holder_commitment {
939 let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(holder_commitment, &self.secp_ctx).expect("sign previous holder commitment");
940 self.prev_holder_htlc_sigs = Some(Self::extract_holder_sigs(holder_commitment, sigs));
945 fn extract_holder_sigs(holder_commitment: &HolderCommitmentTransaction, sigs: Vec<Signature>) -> Vec<Option<(usize, Signature)>> {
946 let mut ret = Vec::new();
947 for (htlc_idx, (holder_sig, htlc)) in sigs.iter().zip(holder_commitment.htlcs().iter()).enumerate() {
948 let tx_idx = htlc.transaction_output_index.unwrap();
949 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
950 ret[tx_idx as usize] = Some((htlc_idx, holder_sig.clone()));
955 //TODO: getting lastest holder transactions should be infallible and result in us "force-closing the channel", but we may
956 // have empty holder commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
957 // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
958 // to monitor before.
959 pub(crate) fn get_fully_signed_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
960 let (sig, htlc_sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("signing holder commitment");
961 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
962 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
965 #[cfg(any(test, feature="unsafe_revoked_tx_signing"))]
966 pub(crate) fn get_fully_signed_copy_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
967 let (sig, htlc_sigs) = self.signer.unsafe_sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
968 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
969 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
972 pub(crate) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
973 let mut htlc_tx = None;
974 let commitment_txid = self.holder_commitment.trust().txid();
975 // Check if the HTLC spends from the current holder commitment
976 if commitment_txid == outp.txid {
977 self.sign_latest_holder_htlcs();
978 if let &Some(ref htlc_sigs) = &self.holder_htlc_sigs {
979 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
980 let trusted_tx = self.holder_commitment.trust();
981 let counterparty_htlc_sig = self.holder_commitment.counterparty_htlc_sigs[*htlc_idx];
982 htlc_tx = Some(trusted_tx
983 .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
986 // If the HTLC doesn't spend the current holder commitment, check if it spends the previous one
987 if htlc_tx.is_none() && self.prev_holder_commitment.is_some() {
988 let commitment_txid = self.prev_holder_commitment.as_ref().unwrap().trust().txid();
989 if commitment_txid == outp.txid {
990 self.sign_prev_holder_htlcs();
991 if let &Some(ref htlc_sigs) = &self.prev_holder_htlc_sigs {
992 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
993 let holder_commitment = self.prev_holder_commitment.as_ref().unwrap();
994 let trusted_tx = holder_commitment.trust();
995 let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[*htlc_idx];
996 htlc_tx = Some(trusted_tx
997 .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
1004 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
1005 pub(crate) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
1006 let latest_had_sigs = self.holder_htlc_sigs.is_some();
1007 let prev_had_sigs = self.prev_holder_htlc_sigs.is_some();
1008 let ret = self.get_fully_signed_htlc_tx(outp, preimage);
1009 if !latest_had_sigs {
1010 self.holder_htlc_sigs = None;
1013 self.prev_holder_htlc_sigs = None;