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::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 and the
43 /// transaction causing it.
45 /// Used to determine when the on-chain event can be considered safe from a chain reorganization.
47 struct OnchainEventEntry {
53 impl OnchainEventEntry {
54 fn confirmation_threshold(&self) -> u32 {
55 self.height + ANTI_REORG_DELAY - 1
58 fn has_reached_confirmation_threshold(&self, height: u32) -> bool {
59 height >= self.confirmation_threshold()
63 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
64 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
67 /// Outpoint under claim process by our own tx, once this one get enough confirmations, we remove it from
68 /// bump-txn candidate buffer.
72 /// Claim tx aggregate multiple claimable outpoints. One of the outpoint may be claimed by a counterparty party tx.
73 /// In this case, we need to drop the outpoint and regenerate a new claim tx. By safety, we keep tracking
74 /// the outpoint to be sure to resurect it back to the claim tx if reorgs happen.
76 outpoint: BitcoinOutPoint,
77 input_material: InputMaterial,
81 /// Higher-level cache structure needed to re-generate bumped claim txn if needed
82 #[derive(Clone, PartialEq)]
83 pub struct ClaimTxBumpMaterial {
84 // At every block tick, used to check if pending claiming tx is taking too
85 // much time for confirmation and we need to bump it.
86 height_timer: Option<u32>,
87 // Tracked in case of reorg to wipe out now-superflous bump material
88 feerate_previous: u32,
89 // Soonest timelocks among set of outpoints claimed, used to compute
90 // a priority of not feerate
91 soonest_timelock: u32,
92 // Cache of script, pubkey, sig or key to solve claimable outputs scriptpubkey.
93 per_input_material: HashMap<BitcoinOutPoint, InputMaterial>,
96 impl Writeable for ClaimTxBumpMaterial {
97 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
98 self.height_timer.write(writer)?;
99 writer.write_all(&byte_utils::be32_to_array(self.feerate_previous))?;
100 writer.write_all(&byte_utils::be32_to_array(self.soonest_timelock))?;
101 writer.write_all(&byte_utils::be64_to_array(self.per_input_material.len() as u64))?;
102 for (outp, tx_material) in self.per_input_material.iter() {
104 tx_material.write(writer)?;
110 impl Readable for ClaimTxBumpMaterial {
111 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
112 let height_timer = Readable::read(reader)?;
113 let feerate_previous = Readable::read(reader)?;
114 let soonest_timelock = Readable::read(reader)?;
115 let per_input_material_len: u64 = Readable::read(reader)?;
116 let mut per_input_material = HashMap::with_capacity(cmp::min(per_input_material_len as usize, MAX_ALLOC_SIZE / 128));
117 for _ in 0 ..per_input_material_len {
118 let outpoint = Readable::read(reader)?;
119 let input_material = Readable::read(reader)?;
120 per_input_material.insert(outpoint, input_material);
122 Ok(Self { height_timer, feerate_previous, soonest_timelock, per_input_material })
126 #[derive(PartialEq, Clone, Copy)]
127 pub(crate) enum InputDescriptors {
132 RevokedOutput, // either a revoked to_holder output on commitment tx, a revoked HTLC-Timeout output or a revoked HTLC-Success output
135 impl Writeable for InputDescriptors {
136 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
138 &InputDescriptors::RevokedOfferedHTLC => {
139 writer.write_all(&[0; 1])?;
141 &InputDescriptors::RevokedReceivedHTLC => {
142 writer.write_all(&[1; 1])?;
144 &InputDescriptors::OfferedHTLC => {
145 writer.write_all(&[2; 1])?;
147 &InputDescriptors::ReceivedHTLC => {
148 writer.write_all(&[3; 1])?;
150 &InputDescriptors::RevokedOutput => {
151 writer.write_all(&[4; 1])?;
158 impl Readable for InputDescriptors {
159 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
160 let input_descriptor = match <u8 as Readable>::read(reader)? {
162 InputDescriptors::RevokedOfferedHTLC
165 InputDescriptors::RevokedReceivedHTLC
168 InputDescriptors::OfferedHTLC
171 InputDescriptors::ReceivedHTLC
174 InputDescriptors::RevokedOutput
176 _ => return Err(DecodeError::InvalidValue),
182 macro_rules! subtract_high_prio_fee {
183 ($logger: ident, $fee_estimator: expr, $value: expr, $predicted_weight: expr, $used_feerate: expr) => {
185 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority).into();
186 let mut fee = $used_feerate as u64 * $predicted_weight / 1000;
188 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal).into();
189 fee = $used_feerate as u64 * $predicted_weight / 1000;
190 if $value <= fee.into() {
191 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background).into();
192 fee = $used_feerate as u64 * $predicted_weight / 1000;
194 log_error!($logger, "Failed to generate an on-chain punishment tx as even low priority fee ({} sat) was more than the entire claim balance ({} sat)",
198 log_warn!($logger, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
204 log_warn!($logger, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
217 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
218 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
219 match Readable::read(reader)? {
222 let vlen: u64 = Readable::read(reader)?;
223 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<Option<(usize, Signature)>>()));
225 ret.push(match Readable::read(reader)? {
227 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
228 _ => return Err(DecodeError::InvalidValue)
233 _ => Err(DecodeError::InvalidValue),
238 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
239 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
243 (vec.len() as u64).write(writer)?;
244 for opt in vec.iter() {
246 &Some((ref idx, ref sig)) => {
248 (*idx as u64).write(writer)?;
251 &None => 0u8.write(writer)?,
255 &None => 0u8.write(writer)?,
262 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
263 /// do RBF bumping if possible.
264 pub struct OnchainTxHandler<ChannelSigner: Sign> {
265 destination_script: Script,
266 holder_commitment: HolderCommitmentTransaction,
267 // holder_htlc_sigs and prev_holder_htlc_sigs are in the order as they appear in the commitment
268 // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
269 // the set of HTLCs in the HolderCommitmentTransaction.
270 holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
271 prev_holder_commitment: Option<HolderCommitmentTransaction>,
272 prev_holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
274 signer: ChannelSigner,
275 pub(crate) channel_transaction_parameters: ChannelTransactionParameters,
277 // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
278 // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
279 // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
280 // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
281 // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
282 // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
283 // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
284 // we need to regenerate new claim request with reduced set of still-claimable outpoints.
285 // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
286 // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
287 // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
288 #[cfg(test)] // Used in functional_test to verify sanitization
289 pub pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
291 pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
293 // Used to link outpoints claimed in a connected block to a pending claim request.
294 // Key is outpoint than monitor parsing has detected we have keys/scripts to claim
295 // Value is (pending claim request identifier, confirmation_block), identifier
296 // is txid of the initial claiming transaction and is immutable until outpoint is
297 // post-anti-reorg-delay solved, confirmaiton_block is used to erase entry if
298 // block with output gets disconnected.
299 #[cfg(test)] // Used in functional_test to verify sanitization
300 pub claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
302 claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
304 onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
308 secp_ctx: Secp256k1<secp256k1::All>,
311 impl<ChannelSigner: Sign> OnchainTxHandler<ChannelSigner> {
312 pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
313 self.destination_script.write(writer)?;
314 self.holder_commitment.write(writer)?;
315 self.holder_htlc_sigs.write(writer)?;
316 self.prev_holder_commitment.write(writer)?;
317 self.prev_holder_htlc_sigs.write(writer)?;
319 self.channel_transaction_parameters.write(writer)?;
321 let mut key_data = VecWriter(Vec::new());
322 self.signer.write(&mut key_data)?;
323 assert!(key_data.0.len() < std::usize::MAX);
324 assert!(key_data.0.len() < std::u32::MAX as usize);
325 (key_data.0.len() as u32).write(writer)?;
326 writer.write_all(&key_data.0[..])?;
328 writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
329 for (ref ancestor_claim_txid, claim_tx_data) in self.pending_claim_requests.iter() {
330 ancestor_claim_txid.write(writer)?;
331 claim_tx_data.write(writer)?;
334 writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
335 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
337 claim_and_height.0.write(writer)?;
338 claim_and_height.1.write(writer)?;
341 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_awaiting_threshold_conf.len() as u64))?;
342 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
343 entry.txid.write(writer)?;
344 writer.write_all(&byte_utils::be32_to_array(entry.height))?;
346 OnchainEvent::Claim { ref claim_request } => {
347 writer.write_all(&[0; 1])?;
348 claim_request.write(writer)?;
350 OnchainEvent::ContentiousOutpoint { ref outpoint, ref input_material } => {
351 writer.write_all(&[1; 1])?;
352 outpoint.write(writer)?;
353 input_material.write(writer)?;
357 self.latest_height.write(writer)?;
362 impl<'a, K: KeysInterface> ReadableArgs<&'a K> for OnchainTxHandler<K::Signer> {
363 fn read<R: ::std::io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
364 let destination_script = Readable::read(reader)?;
366 let holder_commitment = Readable::read(reader)?;
367 let holder_htlc_sigs = Readable::read(reader)?;
368 let prev_holder_commitment = Readable::read(reader)?;
369 let prev_holder_htlc_sigs = Readable::read(reader)?;
371 let channel_parameters = Readable::read(reader)?;
373 let keys_len: u32 = Readable::read(reader)?;
374 let mut keys_data = Vec::with_capacity(cmp::min(keys_len as usize, MAX_ALLOC_SIZE));
375 while keys_data.len() != keys_len as usize {
376 // Read 1KB at a time to avoid accidentally allocating 4GB on corrupted channel keys
377 let mut data = [0; 1024];
378 let read_slice = &mut data[0..cmp::min(1024, keys_len as usize - keys_data.len())];
379 reader.read_exact(read_slice)?;
380 keys_data.extend_from_slice(read_slice);
382 let signer = keys_manager.read_chan_signer(&keys_data)?;
384 let pending_claim_requests_len: u64 = Readable::read(reader)?;
385 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
386 for _ in 0..pending_claim_requests_len {
387 pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
390 let claimable_outpoints_len: u64 = Readable::read(reader)?;
391 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
392 for _ in 0..claimable_outpoints_len {
393 let outpoint = Readable::read(reader)?;
394 let ancestor_claim_txid = Readable::read(reader)?;
395 let height = Readable::read(reader)?;
396 claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
398 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
399 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
400 for _ in 0..waiting_threshold_conf_len {
401 let txid = Readable::read(reader)?;
402 let height = Readable::read(reader)?;
403 let event = match <u8 as Readable>::read(reader)? {
405 let claim_request = Readable::read(reader)?;
406 OnchainEvent::Claim {
411 let outpoint = Readable::read(reader)?;
412 let input_material = Readable::read(reader)?;
413 OnchainEvent::ContentiousOutpoint {
418 _ => return Err(DecodeError::InvalidValue),
420 onchain_events_awaiting_threshold_conf.push(OnchainEventEntry { txid, height, event });
422 let latest_height = Readable::read(reader)?;
424 let mut secp_ctx = Secp256k1::new();
425 secp_ctx.seeded_randomize(&keys_manager.get_secure_random_bytes());
427 Ok(OnchainTxHandler {
431 prev_holder_commitment,
432 prev_holder_htlc_sigs,
434 channel_transaction_parameters: channel_parameters,
436 pending_claim_requests,
437 onchain_events_awaiting_threshold_conf,
444 impl<ChannelSigner: Sign> OnchainTxHandler<ChannelSigner> {
445 pub(crate) fn new(destination_script: Script, signer: ChannelSigner, channel_parameters: ChannelTransactionParameters, holder_commitment: HolderCommitmentTransaction, secp_ctx: Secp256k1<secp256k1::All>) -> Self {
449 holder_htlc_sigs: None,
450 prev_holder_commitment: None,
451 prev_holder_htlc_sigs: None,
453 channel_transaction_parameters: channel_parameters,
454 pending_claim_requests: HashMap::new(),
455 claimable_outpoints: HashMap::new(),
456 onchain_events_awaiting_threshold_conf: Vec::new(),
463 pub(crate) fn get_witnesses_weight(inputs: &[InputDescriptors]) -> usize {
464 let mut tx_weight = 2; // count segwit flags
466 // We use expected weight (and not actual) as signatures and time lock delays may vary
467 tx_weight += match inp {
468 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
469 &InputDescriptors::RevokedOfferedHTLC => {
470 1 + 1 + 73 + 1 + 33 + 1 + 133
472 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
473 &InputDescriptors::RevokedReceivedHTLC => {
474 1 + 1 + 73 + 1 + 33 + 1 + 139
476 // number_of_witness_elements + sig_length + counterpartyhtlc_sig + preimage_length + preimage + witness_script_length + witness_script
477 &InputDescriptors::OfferedHTLC => {
478 1 + 1 + 73 + 1 + 32 + 1 + 133
480 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
481 &InputDescriptors::ReceivedHTLC => {
482 1 + 1 + 73 + 1 + 1 + 1 + 139
484 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
485 &InputDescriptors::RevokedOutput => {
486 1 + 1 + 73 + 1 + 1 + 1 + 77
493 /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
494 /// 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
495 /// height than once reached we should generate a new bumped "version" of the claim tx to be sure than we safely claim outputs before
496 /// than our counterparty can do it too. If timelock expires soon, height timer is going to be scale down in consequence to increase
497 /// frequency of the bump and so increase our bets of success.
498 fn get_height_timer(current_height: u32, timelock_expiration: u32) -> u32 {
499 if timelock_expiration <= current_height + 3 {
500 return current_height + 1
501 } else if timelock_expiration - current_height <= 15 {
502 return current_height + 3
507 /// 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
508 /// (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.
509 /// Panics if there are signing errors, because signing operations in reaction to on-chain events
510 /// are not expected to fail, and if they do, we may lose funds.
511 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)>
512 where F::Target: FeeEstimator,
515 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
516 let mut inputs = Vec::new();
517 for outp in cached_claim_datas.per_input_material.keys() {
518 log_trace!(logger, "Outpoint {}:{}", outp.txid, outp.vout);
520 previous_output: *outp,
521 script_sig: Script::new(),
522 sequence: 0xfffffffd,
526 let mut bumped_tx = Transaction {
531 script_pubkey: self.destination_script.clone(),
536 macro_rules! RBF_bump {
537 ($amount: expr, $old_feerate: expr, $fee_estimator: expr, $predicted_weight: expr) => {
539 let mut used_feerate: u32;
540 // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
541 let new_fee = if $old_feerate < $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) {
542 let mut value = $amount;
543 if subtract_high_prio_fee!(logger, $fee_estimator, value, $predicted_weight, used_feerate) {
544 // Overflow check is done in subtract_high_prio_fee
547 log_trace!(logger, "Can't new-estimation bump new claiming tx, amount {} is too small", $amount);
550 // ...else just increase the previous feerate by 25% (because that's a nice number)
552 let fee = $old_feerate as u64 * ($predicted_weight as u64) / 750;
554 log_trace!(logger, "Can't 25% bump new claiming tx, amount {} is too small", $amount);
560 let previous_fee = $old_feerate as u64 * ($predicted_weight as u64) / 1000;
561 let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * ($predicted_weight as u64) / 1000;
562 // BIP 125 Opt-in Full Replace-by-Fee Signaling
563 // * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
564 // * 4. The replacement transaction must also pay for its own bandwidth at or above the rate set by the node's minimum relay fee setting.
565 let new_fee = if new_fee < previous_fee + min_relay_fee {
566 new_fee + previous_fee + min_relay_fee - new_fee
570 Some((new_fee, new_fee * 1000 / ($predicted_weight as u64)))
575 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
576 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
577 let new_timer = Some(Self::get_height_timer(height, cached_claim_datas.soonest_timelock));
578 let mut inputs_witnesses_weight = 0;
580 let mut dynamic_fee = true;
581 for per_outp_material in cached_claim_datas.per_input_material.values() {
582 match per_outp_material {
583 &InputMaterial::Revoked { ref input_descriptor, ref amount, .. } => {
584 inputs_witnesses_weight += Self::get_witnesses_weight(&[*input_descriptor]);
587 &InputMaterial::CounterpartyHTLC { ref preimage, ref htlc, .. } => {
588 inputs_witnesses_weight += Self::get_witnesses_weight(if preimage.is_some() { &[InputDescriptors::OfferedHTLC] } else { &[InputDescriptors::ReceivedHTLC] });
589 amt += htlc.amount_msat / 1000;
591 &InputMaterial::HolderHTLC { .. } => {
594 &InputMaterial::Funding { .. } => {
600 let predicted_weight = (bumped_tx.get_weight() + inputs_witnesses_weight) as u64;
602 // If old feerate is 0, first iteration of this claim, use normal fee calculation
603 if cached_claim_datas.feerate_previous != 0 {
604 if let Some((new_fee, feerate)) = RBF_bump!(amt, cached_claim_datas.feerate_previous, fee_estimator, predicted_weight) {
605 // If new computed fee is superior at the whole claimable amount burn all in fees
606 if new_fee as u64 > amt {
607 bumped_tx.output[0].value = 0;
609 bumped_tx.output[0].value = amt - new_fee as u64;
611 new_feerate = feerate;
612 } else { return None; }
614 if subtract_high_prio_fee!(logger, fee_estimator, amt, predicted_weight, new_feerate) {
615 bumped_tx.output[0].value = amt;
616 } else { return None; }
618 assert!(new_feerate != 0);
620 for (i, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
621 match per_outp_material {
622 &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 } => {
623 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) {
625 let witness_script = if let Some(ref htlc) = *htlc {
626 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &tx_keys.broadcaster_htlc_key, &tx_keys.countersignatory_htlc_key, &tx_keys.revocation_key)
628 chan_utils::get_revokeable_redeemscript(&tx_keys.revocation_key, *on_counterparty_tx_csv, &tx_keys.broadcaster_delayed_payment_key)
631 let sig = self.signer.sign_justice_transaction(&bumped_tx, i, *amount, &per_commitment_key, htlc, &self.secp_ctx).expect("sign justice tx");
632 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
633 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
635 bumped_tx.input[i].witness.push(tx_keys.revocation_key.clone().serialize().to_vec());
637 bumped_tx.input[i].witness.push(vec!(1));
639 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
641 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);
644 &InputMaterial::CounterpartyHTLC { ref per_commitment_point, ref counterparty_delayed_payment_base_key, ref counterparty_htlc_base_key, ref preimage, ref htlc } => {
645 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) {
646 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);
648 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
649 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");
650 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
651 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
652 if let &Some(preimage) = preimage {
653 bumped_tx.input[i].witness.push(preimage.0.to_vec());
655 // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
656 bumped_tx.input[i].witness.push(vec![]);
658 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
659 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);
665 log_trace!(logger, "...with timer {}", new_timer.unwrap());
666 assert!(predicted_weight >= bumped_tx.get_weight() as u64);
667 return Some((new_timer, new_feerate as u32, bumped_tx))
669 for (_, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
670 match per_outp_material {
671 &InputMaterial::HolderHTLC { ref preimage, ref amount } => {
672 let htlc_tx = self.get_fully_signed_htlc_tx(outp, preimage);
673 if let Some(htlc_tx) = htlc_tx {
674 let feerate = (amount - htlc_tx.output[0].value) * 1000 / htlc_tx.get_weight() as u64;
675 // Timer set to $NEVER given we can't bump tx without anchor outputs
676 log_trace!(logger, "Going to broadcast Holder HTLC-{} claiming HTLC output {} from {}...", if preimage.is_some() { "Success" } else { "Timeout" }, outp.vout, outp.txid);
677 return Some((None, feerate as u32, htlc_tx));
681 &InputMaterial::Funding { ref funding_redeemscript } => {
682 let signed_tx = self.get_fully_signed_holder_tx(funding_redeemscript);
683 // Timer set to $NEVER given we can't bump tx without anchor outputs
684 log_trace!(logger, "Going to broadcast Holder Transaction {} claiming funding output {} from {}...", signed_tx.txid(), outp.vout, outp.txid);
685 return Some((None, self.holder_commitment.feerate_per_kw(), signed_tx));
694 /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
695 /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
696 /// Formerly this was named `block_connected`, but it is now also used for claiming an HTLC output
697 /// if we receive a preimage after force-close.
698 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)
699 where B::Target: BroadcasterInterface,
700 F::Target: FeeEstimator,
703 let height = match latest_height {
705 None => self.latest_height,
707 log_trace!(logger, "Updating claims view at height {} with {} matched transactions and {} claim requests", height, txn_matched.len(), claimable_outpoints.len());
708 let mut new_claims = Vec::new();
709 let mut aggregated_claim = HashMap::new();
710 let mut aggregated_soonest = ::std::u32::MAX;
712 // Try to aggregate outputs if their timelock expiration isn't imminent (absolute_timelock
713 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
714 for req in claimable_outpoints {
715 // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
716 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 {
717 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.absolute_timelock, height + CLTV_SHARED_CLAIM_BUFFER);
718 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
719 let mut single_input = HashMap::new();
720 single_input.insert(req.outpoint, req.witness_data);
721 new_claims.push((req.absolute_timelock, single_input));
723 aggregated_claim.insert(req.outpoint, req.witness_data);
724 if req.absolute_timelock < aggregated_soonest {
725 aggregated_soonest = req.absolute_timelock;
730 new_claims.push((aggregated_soonest, aggregated_claim));
732 // Generate claim transactions and track them to bump if necessary at
733 // height timer expiration (i.e in how many blocks we're going to take action).
734 for (soonest_timelock, claim) in new_claims.drain(..) {
735 let mut claim_material = ClaimTxBumpMaterial { height_timer: None, feerate_previous: 0, soonest_timelock, per_input_material: claim };
736 if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
737 claim_material.height_timer = new_timer;
738 claim_material.feerate_previous = new_feerate;
739 let txid = tx.txid();
740 for k in claim_material.per_input_material.keys() {
741 log_trace!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
742 self.claimable_outpoints.insert(k.clone(), (txid, height));
744 self.pending_claim_requests.insert(txid, claim_material);
745 log_trace!(logger, "Broadcast onchain {}", log_tx!(tx));
746 broadcaster.broadcast_transaction(&tx);
750 let mut bump_candidates = HashMap::new();
751 for tx in txn_matched {
752 // Scan all input to verify is one of the outpoint spent is of interest for us
753 let mut claimed_outputs_material = Vec::new();
754 for inp in &tx.input {
755 if let Some(first_claim_txid_height) = self.claimable_outpoints.get(&inp.previous_output) {
756 // If outpoint has claim request pending on it...
757 if let Some(claim_material) = self.pending_claim_requests.get_mut(&first_claim_txid_height.0) {
758 //... we need to verify equality between transaction outpoints and claim request
759 // outpoints to know if transaction is the original claim or a bumped one issued
761 let mut set_equality = true;
762 if claim_material.per_input_material.len() != tx.input.len() {
763 set_equality = false;
765 for (claim_inp, tx_inp) in claim_material.per_input_material.keys().zip(tx.input.iter()) {
766 if *claim_inp != tx_inp.previous_output {
767 set_equality = false;
772 macro_rules! clean_claim_request_after_safety_delay {
774 let entry = OnchainEventEntry {
777 event: OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() }
779 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
780 self.onchain_events_awaiting_threshold_conf.push(entry);
785 // If this is our transaction (or our counterparty spent all the outputs
786 // before we could anyway with same inputs order than us), wait for
787 // ANTI_REORG_DELAY and clean the RBF tracking map.
789 clean_claim_request_after_safety_delay!();
790 } else { // If false, generate new claim request with update outpoint set
791 let mut at_least_one_drop = false;
792 for input in tx.input.iter() {
793 if let Some(input_material) = claim_material.per_input_material.remove(&input.previous_output) {
794 claimed_outputs_material.push((input.previous_output, input_material));
795 at_least_one_drop = true;
797 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
798 if claim_material.per_input_material.is_empty() {
799 clean_claim_request_after_safety_delay!();
802 //TODO: recompute soonest_timelock to avoid wasting a bit on fees
803 if at_least_one_drop {
804 bump_candidates.insert(first_claim_txid_height.0.clone(), claim_material.clone());
807 break; //No need to iterate further, either tx is our or their
809 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
813 for (outpoint, input_material) in claimed_outputs_material.drain(..) {
814 let entry = OnchainEventEntry {
817 event: OnchainEvent::ContentiousOutpoint { outpoint, input_material },
819 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
820 self.onchain_events_awaiting_threshold_conf.push(entry);
825 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
826 let onchain_events_awaiting_threshold_conf =
827 self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
828 for entry in onchain_events_awaiting_threshold_conf {
829 if entry.has_reached_confirmation_threshold(height) {
831 OnchainEvent::Claim { claim_request } => {
832 // We may remove a whole set of claim outpoints here, as these one may have
833 // been aggregated in a single tx and claimed so atomically
834 if let Some(bump_material) = self.pending_claim_requests.remove(&claim_request) {
835 for outpoint in bump_material.per_input_material.keys() {
836 self.claimable_outpoints.remove(&outpoint);
840 OnchainEvent::ContentiousOutpoint { outpoint, .. } => {
841 self.claimable_outpoints.remove(&outpoint);
845 self.onchain_events_awaiting_threshold_conf.push(entry);
849 // Check if any pending claim request must be rescheduled
850 for (first_claim_txid, ref claim_data) in self.pending_claim_requests.iter() {
851 if let Some(height_timer) = claim_data.height_timer {
852 if height >= height_timer {
853 bump_candidates.insert(*first_claim_txid, (*claim_data).clone());
858 // Build, bump and rebroadcast tx accordingly
859 log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
860 for (first_claim_txid, claim_material) in bump_candidates.iter() {
861 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
862 log_trace!(logger, "Broadcast onchain {}", log_tx!(bump_tx));
863 broadcaster.broadcast_transaction(&bump_tx);
864 if let Some(claim_material) = self.pending_claim_requests.get_mut(first_claim_txid) {
865 claim_material.height_timer = new_timer;
866 claim_material.feerate_previous = new_feerate;
872 pub(crate) fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
879 B::Target: BroadcasterInterface,
880 F::Target: FeeEstimator,
883 let mut height = None;
884 for entry in self.onchain_events_awaiting_threshold_conf.iter() {
885 if entry.txid == *txid {
886 height = Some(entry.height);
891 if let Some(height) = height {
892 self.block_disconnected(height, broadcaster, fee_estimator, logger);
896 pub(crate) fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: F, logger: L)
897 where B::Target: BroadcasterInterface,
898 F::Target: FeeEstimator,
901 let mut bump_candidates = HashMap::new();
902 let onchain_events_awaiting_threshold_conf =
903 self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
904 for entry in onchain_events_awaiting_threshold_conf {
905 if entry.height >= height {
906 //- our claim tx on a commitment tx output
907 //- resurect outpoint back in its claimable set and regenerate tx
909 OnchainEvent::ContentiousOutpoint { outpoint, input_material } => {
910 if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&outpoint) {
911 if let Some(claim_material) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) {
912 claim_material.per_input_material.insert(outpoint, input_material);
913 // Using a HashMap guarantee us than if we have multiple outpoints getting
914 // resurrected only one bump claim tx is going to be broadcast
915 bump_candidates.insert(ancestor_claimable_txid.clone(), claim_material.clone());
922 self.onchain_events_awaiting_threshold_conf.push(entry);
925 for (_, claim_material) in bump_candidates.iter_mut() {
926 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &&*fee_estimator, &&*logger) {
927 claim_material.height_timer = new_timer;
928 claim_material.feerate_previous = new_feerate;
929 broadcaster.broadcast_transaction(&bump_tx);
932 for (ancestor_claim_txid, claim_material) in bump_candidates.drain() {
933 self.pending_claim_requests.insert(ancestor_claim_txid.0, claim_material);
935 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
936 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
937 let mut remove_request = Vec::new();
938 self.claimable_outpoints.retain(|_, ref v|
940 remove_request.push(v.0.clone());
943 for req in remove_request {
944 self.pending_claim_requests.remove(&req);
948 pub(crate) fn get_relevant_txids(&self) -> Vec<Txid> {
949 let mut txids: Vec<Txid> = self.onchain_events_awaiting_threshold_conf
951 .map(|entry| entry.txid)
953 txids.sort_unstable();
958 pub(crate) fn provide_latest_holder_tx(&mut self, tx: HolderCommitmentTransaction) {
959 self.prev_holder_commitment = Some(replace(&mut self.holder_commitment, tx));
960 self.holder_htlc_sigs = None;
963 // Normally holder HTLCs are signed at the same time as the holder commitment tx. However,
964 // in some configurations, the holder commitment tx has been signed and broadcast by a
965 // ChannelMonitor replica, so we handle that case here.
966 fn sign_latest_holder_htlcs(&mut self) {
967 if self.holder_htlc_sigs.is_none() {
968 let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
969 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, sigs));
973 // Normally only the latest commitment tx and HTLCs need to be signed. However, in some
974 // configurations we may have updated our holder commitment but a replica of the ChannelMonitor
975 // broadcast the previous one before we sync with it. We handle that case here.
976 fn sign_prev_holder_htlcs(&mut self) {
977 if self.prev_holder_htlc_sigs.is_none() {
978 if let Some(ref holder_commitment) = self.prev_holder_commitment {
979 let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(holder_commitment, &self.secp_ctx).expect("sign previous holder commitment");
980 self.prev_holder_htlc_sigs = Some(Self::extract_holder_sigs(holder_commitment, sigs));
985 fn extract_holder_sigs(holder_commitment: &HolderCommitmentTransaction, sigs: Vec<Signature>) -> Vec<Option<(usize, Signature)>> {
986 let mut ret = Vec::new();
987 for (htlc_idx, (holder_sig, htlc)) in sigs.iter().zip(holder_commitment.htlcs().iter()).enumerate() {
988 let tx_idx = htlc.transaction_output_index.unwrap();
989 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
990 ret[tx_idx as usize] = Some((htlc_idx, holder_sig.clone()));
995 //TODO: getting lastest holder transactions should be infallible and result in us "force-closing the channel", but we may
996 // have empty holder commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
997 // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
998 // to monitor before.
999 pub(crate) fn get_fully_signed_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
1000 let (sig, htlc_sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("signing holder commitment");
1001 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
1002 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
1005 #[cfg(any(test, feature="unsafe_revoked_tx_signing"))]
1006 pub(crate) fn get_fully_signed_copy_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
1007 let (sig, htlc_sigs) = self.signer.unsafe_sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
1008 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
1009 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
1012 pub(crate) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
1013 let mut htlc_tx = None;
1014 let commitment_txid = self.holder_commitment.trust().txid();
1015 // Check if the HTLC spends from the current holder commitment
1016 if commitment_txid == outp.txid {
1017 self.sign_latest_holder_htlcs();
1018 if let &Some(ref htlc_sigs) = &self.holder_htlc_sigs {
1019 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
1020 let trusted_tx = self.holder_commitment.trust();
1021 let counterparty_htlc_sig = self.holder_commitment.counterparty_htlc_sigs[*htlc_idx];
1022 htlc_tx = Some(trusted_tx
1023 .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
1026 // If the HTLC doesn't spend the current holder commitment, check if it spends the previous one
1027 if htlc_tx.is_none() && self.prev_holder_commitment.is_some() {
1028 let commitment_txid = self.prev_holder_commitment.as_ref().unwrap().trust().txid();
1029 if commitment_txid == outp.txid {
1030 self.sign_prev_holder_htlcs();
1031 if let &Some(ref htlc_sigs) = &self.prev_holder_htlc_sigs {
1032 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
1033 let holder_commitment = self.prev_holder_commitment.as_ref().unwrap();
1034 let trusted_tx = holder_commitment.trust();
1035 let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[*htlc_idx];
1036 htlc_tx = Some(trusted_tx
1037 .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
1044 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
1045 pub(crate) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
1046 let latest_had_sigs = self.holder_htlc_sigs.is_some();
1047 let prev_had_sigs = self.prev_holder_htlc_sigs.is_some();
1048 let ret = self.get_fully_signed_htlc_tx(outp, preimage);
1049 if !latest_had_sigs {
1050 self.holder_htlc_sigs = None;
1053 self.prev_holder_htlc_sigs = None;