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 objetcs 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::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER, InputMaterial, ClaimRequest};
26 use ln::channelmanager::PaymentPreimage;
28 use ln::chan_utils::{TxCreationKeys, HolderCommitmentTransaction};
29 use chain::chaininterface::{FeeEstimator, BroadcasterInterface, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT};
30 use chain::keysinterface::ChannelKeys;
31 use util::logger::Logger;
32 use util::ser::{Readable, Writer, Writeable};
35 use std::collections::{HashMap, hash_map};
39 const MAX_ALLOC_SIZE: usize = 64*1024;
41 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
42 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
43 #[derive(Clone, PartialEq)]
45 /// Outpoint under claim process by our own tx, once this one get enough confirmations, we remove it from
46 /// bump-txn candidate buffer.
50 /// Claim tx aggregate multiple claimable outpoints. One of the outpoint may be claimed by a counterparty party tx.
51 /// In this case, we need to drop the outpoint and regenerate a new claim tx. By safety, we keep tracking
52 /// the outpoint to be sure to resurect it back to the claim tx if reorgs happen.
54 outpoint: BitcoinOutPoint,
55 input_material: InputMaterial,
59 /// Higher-level cache structure needed to re-generate bumped claim txn if needed
60 #[derive(Clone, PartialEq)]
61 pub struct ClaimTxBumpMaterial {
62 // At every block tick, used to check if pending claiming tx is taking too
63 // much time for confirmation and we need to bump it.
64 height_timer: Option<u32>,
65 // Tracked in case of reorg to wipe out now-superflous bump material
66 feerate_previous: u32,
67 // Soonest timelocks among set of outpoints claimed, used to compute
68 // a priority of not feerate
69 soonest_timelock: u32,
70 // Cache of script, pubkey, sig or key to solve claimable outputs scriptpubkey.
71 per_input_material: HashMap<BitcoinOutPoint, InputMaterial>,
74 impl Writeable for ClaimTxBumpMaterial {
75 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
76 self.height_timer.write(writer)?;
77 writer.write_all(&byte_utils::be32_to_array(self.feerate_previous))?;
78 writer.write_all(&byte_utils::be32_to_array(self.soonest_timelock))?;
79 writer.write_all(&byte_utils::be64_to_array(self.per_input_material.len() as u64))?;
80 for (outp, tx_material) in self.per_input_material.iter() {
82 tx_material.write(writer)?;
88 impl Readable for ClaimTxBumpMaterial {
89 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
90 let height_timer = Readable::read(reader)?;
91 let feerate_previous = Readable::read(reader)?;
92 let soonest_timelock = Readable::read(reader)?;
93 let per_input_material_len: u64 = Readable::read(reader)?;
94 let mut per_input_material = HashMap::with_capacity(cmp::min(per_input_material_len as usize, MAX_ALLOC_SIZE / 128));
95 for _ in 0 ..per_input_material_len {
96 let outpoint = Readable::read(reader)?;
97 let input_material = Readable::read(reader)?;
98 per_input_material.insert(outpoint, input_material);
100 Ok(Self { height_timer, feerate_previous, soonest_timelock, per_input_material })
104 #[derive(PartialEq, Clone, Copy)]
105 pub(crate) enum InputDescriptors {
110 RevokedOutput, // either a revoked to_holder output on commitment tx, a revoked HTLC-Timeout output or a revoked HTLC-Success output
113 impl Writeable for InputDescriptors {
114 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
116 &InputDescriptors::RevokedOfferedHTLC => {
117 writer.write_all(&[0; 1])?;
119 &InputDescriptors::RevokedReceivedHTLC => {
120 writer.write_all(&[1; 1])?;
122 &InputDescriptors::OfferedHTLC => {
123 writer.write_all(&[2; 1])?;
125 &InputDescriptors::ReceivedHTLC => {
126 writer.write_all(&[3; 1])?;
128 &InputDescriptors::RevokedOutput => {
129 writer.write_all(&[4; 1])?;
136 impl Readable for InputDescriptors {
137 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
138 let input_descriptor = match <u8 as Readable>::read(reader)? {
140 InputDescriptors::RevokedOfferedHTLC
143 InputDescriptors::RevokedReceivedHTLC
146 InputDescriptors::OfferedHTLC
149 InputDescriptors::ReceivedHTLC
152 InputDescriptors::RevokedOutput
154 _ => return Err(DecodeError::InvalidValue),
160 macro_rules! subtract_high_prio_fee {
161 ($logger: ident, $fee_estimator: expr, $value: expr, $predicted_weight: expr, $used_feerate: expr) => {
163 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority).into();
164 let mut fee = $used_feerate as u64 * $predicted_weight / 1000;
166 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal).into();
167 fee = $used_feerate as u64 * $predicted_weight / 1000;
168 if $value <= fee.into() {
169 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background).into();
170 fee = $used_feerate as u64 * $predicted_weight / 1000;
172 log_error!($logger, "Failed to generate an on-chain punishment tx as even low priority fee ({} sat) was more than the entire claim balance ({} sat)",
176 log_warn!($logger, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
182 log_warn!($logger, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
195 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
196 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
197 match Readable::read(reader)? {
200 let vlen: u64 = Readable::read(reader)?;
201 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<Option<(usize, Signature)>>()));
203 ret.push(match Readable::read(reader)? {
205 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
206 _ => return Err(DecodeError::InvalidValue)
211 _ => Err(DecodeError::InvalidValue),
216 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
217 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
221 (vec.len() as u64).write(writer)?;
222 for opt in vec.iter() {
224 &Some((ref idx, ref sig)) => {
226 (*idx as u64).write(writer)?;
229 &None => 0u8.write(writer)?,
233 &None => 0u8.write(writer)?,
240 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
241 /// do RBF bumping if possible.
242 pub struct OnchainTxHandler<ChanSigner: ChannelKeys> {
243 destination_script: Script,
244 holder_commitment: Option<HolderCommitmentTransaction>,
245 // holder_htlc_sigs and prev_holder_htlc_sigs are in the order as they appear in the commitment
246 // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
247 // the set of HTLCs in the HolderCommitmentTransaction (including those which do not appear in
248 // the commitment transaction).
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)>>>,
252 on_holder_tx_csv: u16,
254 key_storage: ChanSigner,
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>>,
285 secp_ctx: Secp256k1<secp256k1::All>,
288 impl<ChanSigner: ChannelKeys + Writeable> OnchainTxHandler<ChanSigner> {
289 pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
290 self.destination_script.write(writer)?;
291 self.holder_commitment.write(writer)?;
292 self.holder_htlc_sigs.write(writer)?;
293 self.prev_holder_commitment.write(writer)?;
294 self.prev_holder_htlc_sigs.write(writer)?;
296 self.on_holder_tx_csv.write(writer)?;
298 self.key_storage.write(writer)?;
300 writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
301 for (ref ancestor_claim_txid, claim_tx_data) in self.pending_claim_requests.iter() {
302 ancestor_claim_txid.write(writer)?;
303 claim_tx_data.write(writer)?;
306 writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
307 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
309 claim_and_height.0.write(writer)?;
310 claim_and_height.1.write(writer)?;
313 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
314 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
315 writer.write_all(&byte_utils::be32_to_array(**target))?;
316 writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
317 for ev in events.iter() {
319 OnchainEvent::Claim { ref claim_request } => {
320 writer.write_all(&[0; 1])?;
321 claim_request.write(writer)?;
323 OnchainEvent::ContentiousOutpoint { ref outpoint, ref input_material } => {
324 writer.write_all(&[1; 1])?;
325 outpoint.write(writer)?;
326 input_material.write(writer)?;
335 impl<ChanSigner: ChannelKeys + Readable> Readable for OnchainTxHandler<ChanSigner> {
336 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
337 let destination_script = Readable::read(reader)?;
339 let holder_commitment = Readable::read(reader)?;
340 let holder_htlc_sigs = Readable::read(reader)?;
341 let prev_holder_commitment = Readable::read(reader)?;
342 let prev_holder_htlc_sigs = Readable::read(reader)?;
344 let on_holder_tx_csv = Readable::read(reader)?;
346 let key_storage = Readable::read(reader)?;
348 let pending_claim_requests_len: u64 = Readable::read(reader)?;
349 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
350 for _ in 0..pending_claim_requests_len {
351 pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
354 let claimable_outpoints_len: u64 = Readable::read(reader)?;
355 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
356 for _ in 0..claimable_outpoints_len {
357 let outpoint = Readable::read(reader)?;
358 let ancestor_claim_txid = Readable::read(reader)?;
359 let height = Readable::read(reader)?;
360 claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
362 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
363 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
364 for _ in 0..waiting_threshold_conf_len {
365 let height_target = Readable::read(reader)?;
366 let events_len: u64 = Readable::read(reader)?;
367 let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
368 for _ in 0..events_len {
369 let ev = match <u8 as Readable>::read(reader)? {
371 let claim_request = Readable::read(reader)?;
372 OnchainEvent::Claim {
377 let outpoint = Readable::read(reader)?;
378 let input_material = Readable::read(reader)?;
379 OnchainEvent::ContentiousOutpoint {
384 _ => return Err(DecodeError::InvalidValue),
388 onchain_events_waiting_threshold_conf.insert(height_target, events);
391 Ok(OnchainTxHandler {
395 prev_holder_commitment,
396 prev_holder_htlc_sigs,
400 pending_claim_requests,
401 onchain_events_waiting_threshold_conf,
402 secp_ctx: Secp256k1::new(),
407 impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
408 pub(super) fn new(destination_script: Script, keys: ChanSigner, on_holder_tx_csv: u16) -> Self {
410 let key_storage = keys;
414 holder_commitment: None,
415 holder_htlc_sigs: None,
416 prev_holder_commitment: None,
417 prev_holder_htlc_sigs: None,
420 pending_claim_requests: HashMap::new(),
421 claimable_outpoints: HashMap::new(),
422 onchain_events_waiting_threshold_conf: HashMap::new(),
424 secp_ctx: Secp256k1::new(),
428 pub(super) fn get_witnesses_weight(inputs: &[InputDescriptors]) -> usize {
429 let mut tx_weight = 2; // count segwit flags
431 // We use expected weight (and not actual) as signatures and time lock delays may vary
432 tx_weight += match inp {
433 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
434 &InputDescriptors::RevokedOfferedHTLC => {
435 1 + 1 + 73 + 1 + 33 + 1 + 133
437 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
438 &InputDescriptors::RevokedReceivedHTLC => {
439 1 + 1 + 73 + 1 + 33 + 1 + 139
441 // number_of_witness_elements + sig_length + counterpartyhtlc_sig + preimage_length + preimage + witness_script_length + witness_script
442 &InputDescriptors::OfferedHTLC => {
443 1 + 1 + 73 + 1 + 32 + 1 + 133
445 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
446 &InputDescriptors::ReceivedHTLC => {
447 1 + 1 + 73 + 1 + 1 + 1 + 139
449 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
450 &InputDescriptors::RevokedOutput => {
451 1 + 1 + 73 + 1 + 1 + 1 + 77
458 /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
459 /// 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
460 /// height than once reached we should generate a new bumped "version" of the claim tx to be sure than we safely claim outputs before
461 /// than our counterparty can do it too. If timelock expires soon, height timer is going to be scale down in consequence to increase
462 /// frequency of the bump and so increase our bets of success.
463 fn get_height_timer(current_height: u32, timelock_expiration: u32) -> u32 {
464 if timelock_expiration <= current_height + 3 {
465 return current_height + 1
466 } else if timelock_expiration - current_height <= 15 {
467 return current_height + 3
472 /// 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
473 /// (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.
474 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)>
475 where F::Target: FeeEstimator,
478 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
479 let mut inputs = Vec::new();
480 for outp in cached_claim_datas.per_input_material.keys() {
481 log_trace!(logger, "Outpoint {}:{}", outp.txid, outp.vout);
483 previous_output: *outp,
484 script_sig: Script::new(),
485 sequence: 0xfffffffd,
489 let mut bumped_tx = Transaction {
494 script_pubkey: self.destination_script.clone(),
499 macro_rules! RBF_bump {
500 ($amount: expr, $old_feerate: expr, $fee_estimator: expr, $predicted_weight: expr) => {
502 let mut used_feerate: u32;
503 // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
504 let new_fee = if $old_feerate < $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) {
505 let mut value = $amount;
506 if subtract_high_prio_fee!(logger, $fee_estimator, value, $predicted_weight, used_feerate) {
507 // Overflow check is done in subtract_high_prio_fee
510 log_trace!(logger, "Can't new-estimation bump new claiming tx, amount {} is too small", $amount);
513 // ...else just increase the previous feerate by 25% (because that's a nice number)
515 let fee = $old_feerate as u64 * ($predicted_weight as u64) / 750;
517 log_trace!(logger, "Can't 25% bump new claiming tx, amount {} is too small", $amount);
523 let previous_fee = $old_feerate as u64 * ($predicted_weight as u64) / 1000;
524 let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * ($predicted_weight as u64) / 1000;
525 // BIP 125 Opt-in Full Replace-by-Fee Signaling
526 // * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
527 // * 4. The replacement transaction must also pay for its own bandwidth at or above the rate set by the node's minimum relay fee setting.
528 let new_fee = if new_fee < previous_fee + min_relay_fee {
529 new_fee + previous_fee + min_relay_fee - new_fee
533 Some((new_fee, new_fee * 1000 / ($predicted_weight as u64)))
538 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
539 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
540 let new_timer = Some(Self::get_height_timer(height, cached_claim_datas.soonest_timelock));
541 let mut inputs_witnesses_weight = 0;
543 let mut dynamic_fee = true;
544 for per_outp_material in cached_claim_datas.per_input_material.values() {
545 match per_outp_material {
546 &InputMaterial::Revoked { ref input_descriptor, ref amount, .. } => {
547 inputs_witnesses_weight += Self::get_witnesses_weight(&[*input_descriptor]);
550 &InputMaterial::CounterpartyHTLC { ref preimage, ref htlc, .. } => {
551 inputs_witnesses_weight += Self::get_witnesses_weight(if preimage.is_some() { &[InputDescriptors::OfferedHTLC] } else { &[InputDescriptors::ReceivedHTLC] });
552 amt += htlc.amount_msat / 1000;
554 &InputMaterial::HolderHTLC { .. } => {
557 &InputMaterial::Funding { .. } => {
563 let predicted_weight = (bumped_tx.get_weight() + inputs_witnesses_weight) as u64;
565 // If old feerate is 0, first iteration of this claim, use normal fee calculation
566 if cached_claim_datas.feerate_previous != 0 {
567 if let Some((new_fee, feerate)) = RBF_bump!(amt, cached_claim_datas.feerate_previous, fee_estimator, predicted_weight) {
568 // If new computed fee is superior at the whole claimable amount burn all in fees
569 if new_fee as u64 > amt {
570 bumped_tx.output[0].value = 0;
572 bumped_tx.output[0].value = amt - new_fee as u64;
574 new_feerate = feerate;
575 } else { return None; }
577 if subtract_high_prio_fee!(logger, fee_estimator, amt, predicted_weight, new_feerate) {
578 bumped_tx.output[0].value = amt;
579 } else { return None; }
581 assert!(new_feerate != 0);
583 for (i, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
584 match per_outp_material {
585 &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 } => {
586 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) {
588 let witness_script = if let Some(ref htlc) = *htlc {
589 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key)
591 chan_utils::get_revokeable_redeemscript(&chan_keys.revocation_key, *on_counterparty_tx_csv, &chan_keys.broadcaster_delayed_payment_key)
594 if let Ok(sig) = self.key_storage.sign_justice_transaction(&bumped_tx, i, *amount, &per_commitment_key, htlc, &self.secp_ctx) {
595 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
596 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
598 bumped_tx.input[i].witness.push(chan_keys.revocation_key.clone().serialize().to_vec());
600 bumped_tx.input[i].witness.push(vec!(1));
602 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
603 } else { return None; }
606 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);
609 &InputMaterial::CounterpartyHTLC { ref per_commitment_point, ref counterparty_delayed_payment_base_key, ref counterparty_htlc_base_key, ref preimage, ref htlc } => {
610 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) {
611 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);
613 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
614 if let Ok(sig) = self.key_storage.sign_counterparty_htlc_transaction(&bumped_tx, i, &htlc.amount_msat / 1000, &per_commitment_point, htlc, &self.secp_ctx) {
615 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
616 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
617 if let &Some(preimage) = preimage {
618 bumped_tx.input[i].witness.push(preimage.0.to_vec());
620 // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
621 bumped_tx.input[i].witness.push(vec![]);
623 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
625 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);
631 log_trace!(logger, "...with timer {}", new_timer.unwrap());
632 assert!(predicted_weight >= bumped_tx.get_weight() as u64);
633 return Some((new_timer, new_feerate as u32, bumped_tx))
635 for (_, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
636 match per_outp_material {
637 &InputMaterial::HolderHTLC { ref preimage, ref amount } => {
638 let htlc_tx = self.get_fully_signed_htlc_tx(outp, preimage);
639 if let Some(htlc_tx) = htlc_tx {
640 let feerate = (amount - htlc_tx.output[0].value) * 1000 / htlc_tx.get_weight() as u64;
641 // Timer set to $NEVER given we can't bump tx without anchor outputs
642 log_trace!(logger, "Going to broadcast Holder HTLC-{} claiming HTLC output {} from {}...", if preimage.is_some() { "Success" } else { "Timeout" }, outp.vout, outp.txid);
643 return Some((None, feerate as u32, htlc_tx));
647 &InputMaterial::Funding { ref funding_redeemscript } => {
648 let signed_tx = self.get_fully_signed_holder_tx(funding_redeemscript).unwrap();
649 // Timer set to $NEVER given we can't bump tx without anchor outputs
650 log_trace!(logger, "Going to broadcast Holder Transaction {} claiming funding output {} from {}...", signed_tx.txid(), outp.vout, outp.txid);
651 return Some((None, self.holder_commitment.as_ref().unwrap().feerate_per_kw, signed_tx));
660 pub(super) fn block_connected<B: Deref, F: Deref, L: Deref>(&mut self, txn_matched: &[(usize, &Transaction)], claimable_outpoints: Vec<ClaimRequest>, height: u32, broadcaster: B, fee_estimator: F, logger: L)
661 where B::Target: BroadcasterInterface,
662 F::Target: FeeEstimator,
665 log_trace!(logger, "Block at height {} connected with {} claim requests", height, claimable_outpoints.len());
666 let mut new_claims = Vec::new();
667 let mut aggregated_claim = HashMap::new();
668 let mut aggregated_soonest = ::std::u32::MAX;
670 // Try to aggregate outputs if their timelock expiration isn't imminent (absolute_timelock
671 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
672 for req in claimable_outpoints {
673 // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
674 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 {
675 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.absolute_timelock, height + CLTV_SHARED_CLAIM_BUFFER);
676 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
677 let mut single_input = HashMap::new();
678 single_input.insert(req.outpoint, req.witness_data);
679 new_claims.push((req.absolute_timelock, single_input));
681 aggregated_claim.insert(req.outpoint, req.witness_data);
682 if req.absolute_timelock < aggregated_soonest {
683 aggregated_soonest = req.absolute_timelock;
688 new_claims.push((aggregated_soonest, aggregated_claim));
690 // Generate claim transactions and track them to bump if necessary at
691 // height timer expiration (i.e in how many blocks we're going to take action).
692 for (soonest_timelock, claim) in new_claims.drain(..) {
693 let mut claim_material = ClaimTxBumpMaterial { height_timer: None, feerate_previous: 0, soonest_timelock, per_input_material: claim };
694 if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
695 claim_material.height_timer = new_timer;
696 claim_material.feerate_previous = new_feerate;
697 let txid = tx.txid();
698 for k in claim_material.per_input_material.keys() {
699 log_trace!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
700 self.claimable_outpoints.insert(k.clone(), (txid, height));
702 self.pending_claim_requests.insert(txid, claim_material);
703 log_trace!(logger, "Broadcast onchain {}", log_tx!(tx));
704 broadcaster.broadcast_transaction(&tx);
708 let mut bump_candidates = HashMap::new();
709 for &(_, tx) in txn_matched {
710 // Scan all input to verify is one of the outpoint spent is of interest for us
711 let mut claimed_outputs_material = Vec::new();
712 for inp in &tx.input {
713 if let Some(first_claim_txid_height) = self.claimable_outpoints.get(&inp.previous_output) {
714 // If outpoint has claim request pending on it...
715 if let Some(claim_material) = self.pending_claim_requests.get_mut(&first_claim_txid_height.0) {
716 //... we need to verify equality between transaction outpoints and claim request
717 // outpoints to know if transaction is the original claim or a bumped one issued
719 let mut set_equality = true;
720 if claim_material.per_input_material.len() != tx.input.len() {
721 set_equality = false;
723 for (claim_inp, tx_inp) in claim_material.per_input_material.keys().zip(tx.input.iter()) {
724 if *claim_inp != tx_inp.previous_output {
725 set_equality = false;
730 macro_rules! clean_claim_request_after_safety_delay {
732 let new_event = OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() };
733 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
734 hash_map::Entry::Occupied(mut entry) => {
735 if !entry.get().contains(&new_event) {
736 entry.get_mut().push(new_event);
739 hash_map::Entry::Vacant(entry) => {
740 entry.insert(vec![new_event]);
746 // If this is our transaction (or our counterparty spent all the outputs
747 // before we could anyway with same inputs order than us), wait for
748 // ANTI_REORG_DELAY and clean the RBF tracking map.
750 clean_claim_request_after_safety_delay!();
751 } else { // If false, generate new claim request with update outpoint set
752 let mut at_least_one_drop = false;
753 for input in tx.input.iter() {
754 if let Some(input_material) = claim_material.per_input_material.remove(&input.previous_output) {
755 claimed_outputs_material.push((input.previous_output, input_material));
756 at_least_one_drop = true;
758 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
759 if claim_material.per_input_material.is_empty() {
760 clean_claim_request_after_safety_delay!();
763 //TODO: recompute soonest_timelock to avoid wasting a bit on fees
764 if at_least_one_drop {
765 bump_candidates.insert(first_claim_txid_height.0.clone(), claim_material.clone());
768 break; //No need to iterate further, either tx is our or their
770 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
774 for (outpoint, input_material) in claimed_outputs_material.drain(..) {
775 let new_event = OnchainEvent::ContentiousOutpoint { outpoint, input_material };
776 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
777 hash_map::Entry::Occupied(mut entry) => {
778 if !entry.get().contains(&new_event) {
779 entry.get_mut().push(new_event);
782 hash_map::Entry::Vacant(entry) => {
783 entry.insert(vec![new_event]);
789 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
790 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
793 OnchainEvent::Claim { claim_request } => {
794 // We may remove a whole set of claim outpoints here, as these one may have
795 // been aggregated in a single tx and claimed so atomically
796 if let Some(bump_material) = self.pending_claim_requests.remove(&claim_request) {
797 for outpoint in bump_material.per_input_material.keys() {
798 self.claimable_outpoints.remove(&outpoint);
802 OnchainEvent::ContentiousOutpoint { outpoint, .. } => {
803 self.claimable_outpoints.remove(&outpoint);
809 // Check if any pending claim request must be rescheduled
810 for (first_claim_txid, ref claim_data) in self.pending_claim_requests.iter() {
811 if let Some(h) = claim_data.height_timer {
813 bump_candidates.insert(*first_claim_txid, (*claim_data).clone());
818 // Build, bump and rebroadcast tx accordingly
819 log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
820 for (first_claim_txid, claim_material) in bump_candidates.iter() {
821 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
822 log_trace!(logger, "Broadcast onchain {}", log_tx!(bump_tx));
823 broadcaster.broadcast_transaction(&bump_tx);
824 if let Some(claim_material) = self.pending_claim_requests.get_mut(first_claim_txid) {
825 claim_material.height_timer = new_timer;
826 claim_material.feerate_previous = new_feerate;
832 pub(super) fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: F, logger: L)
833 where B::Target: BroadcasterInterface,
834 F::Target: FeeEstimator,
837 let mut bump_candidates = HashMap::new();
838 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
839 //- our claim tx on a commitment tx output
840 //- resurect outpoint back in its claimable set and regenerate tx
843 OnchainEvent::ContentiousOutpoint { outpoint, input_material } => {
844 if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&outpoint) {
845 if let Some(claim_material) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) {
846 claim_material.per_input_material.insert(outpoint, input_material);
847 // Using a HashMap guarantee us than if we have multiple outpoints getting
848 // resurrected only one bump claim tx is going to be broadcast
849 bump_candidates.insert(ancestor_claimable_txid.clone(), claim_material.clone());
857 for (_, claim_material) in bump_candidates.iter_mut() {
858 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
859 claim_material.height_timer = new_timer;
860 claim_material.feerate_previous = new_feerate;
861 broadcaster.broadcast_transaction(&bump_tx);
864 for (ancestor_claim_txid, claim_material) in bump_candidates.drain() {
865 self.pending_claim_requests.insert(ancestor_claim_txid.0, claim_material);
867 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
868 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
869 let mut remove_request = Vec::new();
870 self.claimable_outpoints.retain(|_, ref v|
872 remove_request.push(v.0.clone());
875 for req in remove_request {
876 self.pending_claim_requests.remove(&req);
880 pub(super) fn provide_latest_holder_tx(&mut self, tx: HolderCommitmentTransaction) {
881 self.prev_holder_commitment = self.holder_commitment.take();
882 self.holder_commitment = Some(tx);
885 fn sign_latest_holder_htlcs(&mut self) {
886 if let Some(ref holder_commitment) = self.holder_commitment {
887 if let Ok(sigs) = self.key_storage.sign_holder_commitment_htlc_transactions(holder_commitment, &self.secp_ctx) {
888 self.holder_htlc_sigs = Some(Vec::new());
889 let ret = self.holder_htlc_sigs.as_mut().unwrap();
890 for (htlc_idx, (holder_sig, &(ref htlc, _))) in sigs.iter().zip(holder_commitment.per_htlc.iter()).enumerate() {
891 if let Some(tx_idx) = htlc.transaction_output_index {
892 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
893 ret[tx_idx as usize] = Some((htlc_idx, holder_sig.expect("Did not receive a signature for a non-dust HTLC")));
895 assert!(holder_sig.is_none(), "Received a signature for a dust HTLC");
901 fn sign_prev_holder_htlcs(&mut self) {
902 if let Some(ref holder_commitment) = self.prev_holder_commitment {
903 if let Ok(sigs) = self.key_storage.sign_holder_commitment_htlc_transactions(holder_commitment, &self.secp_ctx) {
904 self.prev_holder_htlc_sigs = Some(Vec::new());
905 let ret = self.prev_holder_htlc_sigs.as_mut().unwrap();
906 for (htlc_idx, (holder_sig, &(ref htlc, _))) in sigs.iter().zip(holder_commitment.per_htlc.iter()).enumerate() {
907 if let Some(tx_idx) = htlc.transaction_output_index {
908 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
909 ret[tx_idx as usize] = Some((htlc_idx, holder_sig.expect("Did not receive a signature for a non-dust HTLC")));
911 assert!(holder_sig.is_none(), "Received a signature for a dust HTLC");
918 //TODO: getting lastest holder transactions should be infaillible and result in us "force-closing the channel", but we may
919 // have empty holder commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
920 // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
921 // to monitor before.
922 pub(super) fn get_fully_signed_holder_tx(&mut self, funding_redeemscript: &Script) -> Option<Transaction> {
923 if let Some(ref mut holder_commitment) = self.holder_commitment {
924 match self.key_storage.sign_holder_commitment(holder_commitment, &self.secp_ctx) {
925 Ok(sig) => Some(holder_commitment.add_holder_sig(funding_redeemscript, sig)),
926 Err(_) => return None,
933 #[cfg(any(test, feature="unsafe_revoked_tx_signing"))]
934 pub(super) fn get_fully_signed_copy_holder_tx(&mut self, funding_redeemscript: &Script) -> Option<Transaction> {
935 if let Some(ref mut holder_commitment) = self.holder_commitment {
936 let holder_commitment = holder_commitment.clone();
937 match self.key_storage.sign_holder_commitment(&holder_commitment, &self.secp_ctx) {
938 Ok(sig) => Some(holder_commitment.add_holder_sig(funding_redeemscript, sig)),
939 Err(_) => return None,
946 pub(super) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
947 let mut htlc_tx = None;
948 if self.holder_commitment.is_some() {
949 let commitment_txid = self.holder_commitment.as_ref().unwrap().txid();
950 if commitment_txid == outp.txid {
951 self.sign_latest_holder_htlcs();
952 if let &Some(ref htlc_sigs) = &self.holder_htlc_sigs {
953 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
954 htlc_tx = Some(self.holder_commitment.as_ref().unwrap()
955 .get_signed_htlc_tx(*htlc_idx, htlc_sig, preimage, self.on_holder_tx_csv));
959 if self.prev_holder_commitment.is_some() {
960 let commitment_txid = self.prev_holder_commitment.as_ref().unwrap().txid();
961 if commitment_txid == outp.txid {
962 self.sign_prev_holder_htlcs();
963 if let &Some(ref htlc_sigs) = &self.prev_holder_htlc_sigs {
964 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
965 htlc_tx = Some(self.prev_holder_commitment.as_ref().unwrap()
966 .get_signed_htlc_tx(*htlc_idx, htlc_sig, preimage, self.on_holder_tx_csv));
973 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
974 pub(super) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
975 let latest_had_sigs = self.holder_htlc_sigs.is_some();
976 let prev_had_sigs = self.prev_holder_htlc_sigs.is_some();
977 let ret = self.get_fully_signed_htlc_tx(outp, preimage);
978 if !latest_had_sigs {
979 self.holder_htlc_sigs = None;
982 self.prev_holder_htlc_sigs = None;