1 //! The logic to build claims and bump in-flight transactions until confirmations.
3 //! OnchainTxHandler objetcs are fully-part of ChannelMonitor and encapsulates all
4 //! building, tracking, bumping and notifications functions.
6 use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
7 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
8 use bitcoin::blockdata::script::Script;
9 use bitcoin::util::bip143;
11 use bitcoin::hash_types::Txid;
13 use bitcoin::secp256k1::{Secp256k1, Signature};
14 use bitcoin::secp256k1;
16 use ln::msgs::DecodeError;
17 use ln::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER, InputMaterial, ClaimRequest};
18 use ln::channelmanager::PaymentPreimage;
19 use ln::chan_utils::{HTLCType, LocalCommitmentTransaction};
20 use chain::chaininterface::{FeeEstimator, BroadcasterInterface, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT};
21 use chain::keysinterface::ChannelKeys;
22 use util::logger::Logger;
23 use util::ser::{Readable, Writer, Writeable};
26 use std::collections::{HashMap, hash_map};
30 const MAX_ALLOC_SIZE: usize = 64*1024;
32 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
33 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
34 #[derive(Clone, PartialEq)]
36 /// Outpoint under claim process by our own tx, once this one get enough confirmations, we remove it from
37 /// bump-txn candidate buffer.
41 /// Claim tx aggregate multiple claimable outpoints. One of the outpoint may be claimed by a remote party tx.
42 /// In this case, we need to drop the outpoint and regenerate a new claim tx. By safety, we keep tracking
43 /// the outpoint to be sure to resurect it back to the claim tx if reorgs happen.
45 outpoint: BitcoinOutPoint,
46 input_material: InputMaterial,
50 /// Higher-level cache structure needed to re-generate bumped claim txn if needed
51 #[derive(Clone, PartialEq)]
52 pub struct ClaimTxBumpMaterial {
53 // At every block tick, used to check if pending claiming tx is taking too
54 // much time for confirmation and we need to bump it.
55 height_timer: Option<u32>,
56 // Tracked in case of reorg to wipe out now-superflous bump material
57 feerate_previous: u64,
58 // Soonest timelocks among set of outpoints claimed, used to compute
59 // a priority of not feerate
60 soonest_timelock: u32,
61 // Cache of script, pubkey, sig or key to solve claimable outputs scriptpubkey.
62 per_input_material: HashMap<BitcoinOutPoint, InputMaterial>,
65 impl Writeable for ClaimTxBumpMaterial {
66 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
67 self.height_timer.write(writer)?;
68 writer.write_all(&byte_utils::be64_to_array(self.feerate_previous))?;
69 writer.write_all(&byte_utils::be32_to_array(self.soonest_timelock))?;
70 writer.write_all(&byte_utils::be64_to_array(self.per_input_material.len() as u64))?;
71 for (outp, tx_material) in self.per_input_material.iter() {
73 tx_material.write(writer)?;
79 impl Readable for ClaimTxBumpMaterial {
80 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
81 let height_timer = Readable::read(reader)?;
82 let feerate_previous = Readable::read(reader)?;
83 let soonest_timelock = Readable::read(reader)?;
84 let per_input_material_len: u64 = Readable::read(reader)?;
85 let mut per_input_material = HashMap::with_capacity(cmp::min(per_input_material_len as usize, MAX_ALLOC_SIZE / 128));
86 for _ in 0 ..per_input_material_len {
87 let outpoint = Readable::read(reader)?;
88 let input_material = Readable::read(reader)?;
89 per_input_material.insert(outpoint, input_material);
91 Ok(Self { height_timer, feerate_previous, soonest_timelock, per_input_material })
96 pub(super) enum InputDescriptors {
101 RevokedOutput, // either a revoked to_local output on commitment tx, a revoked HTLC-Timeout output or a revoked HTLC-Success output
104 macro_rules! subtract_high_prio_fee {
105 ($logger: ident, $fee_estimator: expr, $value: expr, $predicted_weight: expr, $used_feerate: expr) => {
107 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority);
108 let mut fee = $used_feerate * ($predicted_weight as u64) / 1000;
110 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);
111 fee = $used_feerate * ($predicted_weight as u64) / 1000;
113 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
114 fee = $used_feerate * ($predicted_weight as u64) / 1000;
116 log_error!($logger, "Failed to generate an on-chain punishment tx as even low priority fee ({} sat) was more than the entire claim balance ({} sat)",
120 log_warn!($logger, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
126 log_warn!($logger, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
139 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
140 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
141 match Readable::read(reader)? {
144 let vlen: u64 = Readable::read(reader)?;
145 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<Option<(usize, Signature)>>()));
147 ret.push(match Readable::read(reader)? {
149 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
150 _ => return Err(DecodeError::InvalidValue)
155 _ => Err(DecodeError::InvalidValue),
160 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
161 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
165 (vec.len() as u64).write(writer)?;
166 for opt in vec.iter() {
168 &Some((ref idx, ref sig)) => {
170 (*idx as u64).write(writer)?;
173 &None => 0u8.write(writer)?,
177 &None => 0u8.write(writer)?,
184 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
185 /// do RBF bumping if possible.
186 pub struct OnchainTxHandler<ChanSigner: ChannelKeys> {
187 destination_script: Script,
188 local_commitment: Option<LocalCommitmentTransaction>,
189 // local_htlc_sigs and prev_local_htlc_sigs are in the order as they appear in the commitment
190 // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
191 // the set of HTLCs in the LocalCommitmentTransaction (including those which do not appear in
192 // the commitment transaction).
193 local_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
194 prev_local_commitment: Option<LocalCommitmentTransaction>,
195 prev_local_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
198 key_storage: ChanSigner,
200 // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
201 // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
202 // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
203 // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
204 // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
205 // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
206 // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
207 // we need to regenerate new claim request with reduced set of still-claimable outpoints.
208 // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
209 // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
210 // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
211 #[cfg(test)] // Used in functional_test to verify sanitization
212 pub pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
214 pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
216 // Used to link outpoints claimed in a connected block to a pending claim request.
217 // Key is outpoint than monitor parsing has detected we have keys/scripts to claim
218 // Value is (pending claim request identifier, confirmation_block), identifier
219 // is txid of the initial claiming transaction and is immutable until outpoint is
220 // post-anti-reorg-delay solved, confirmaiton_block is used to erase entry if
221 // block with output gets disconnected.
222 #[cfg(test)] // Used in functional_test to verify sanitization
223 pub claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
225 claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
227 onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
229 secp_ctx: Secp256k1<secp256k1::All>,
232 impl<ChanSigner: ChannelKeys + Writeable> OnchainTxHandler<ChanSigner> {
233 pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
234 self.destination_script.write(writer)?;
235 self.local_commitment.write(writer)?;
236 self.local_htlc_sigs.write(writer)?;
237 self.prev_local_commitment.write(writer)?;
238 self.prev_local_htlc_sigs.write(writer)?;
240 self.local_csv.write(writer)?;
242 self.key_storage.write(writer)?;
244 writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
245 for (ref ancestor_claim_txid, claim_tx_data) in self.pending_claim_requests.iter() {
246 ancestor_claim_txid.write(writer)?;
247 claim_tx_data.write(writer)?;
250 writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
251 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
253 claim_and_height.0.write(writer)?;
254 claim_and_height.1.write(writer)?;
257 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
258 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
259 writer.write_all(&byte_utils::be32_to_array(**target))?;
260 writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
261 for ev in events.iter() {
263 OnchainEvent::Claim { ref claim_request } => {
264 writer.write_all(&[0; 1])?;
265 claim_request.write(writer)?;
267 OnchainEvent::ContentiousOutpoint { ref outpoint, ref input_material } => {
268 writer.write_all(&[1; 1])?;
269 outpoint.write(writer)?;
270 input_material.write(writer)?;
279 impl<ChanSigner: ChannelKeys + Readable> Readable for OnchainTxHandler<ChanSigner> {
280 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
281 let destination_script = Readable::read(reader)?;
283 let local_commitment = Readable::read(reader)?;
284 let local_htlc_sigs = Readable::read(reader)?;
285 let prev_local_commitment = Readable::read(reader)?;
286 let prev_local_htlc_sigs = Readable::read(reader)?;
288 let local_csv = Readable::read(reader)?;
290 let key_storage = Readable::read(reader)?;
292 let pending_claim_requests_len: u64 = Readable::read(reader)?;
293 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
294 for _ in 0..pending_claim_requests_len {
295 pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
298 let claimable_outpoints_len: u64 = Readable::read(reader)?;
299 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
300 for _ in 0..claimable_outpoints_len {
301 let outpoint = Readable::read(reader)?;
302 let ancestor_claim_txid = Readable::read(reader)?;
303 let height = Readable::read(reader)?;
304 claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
306 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
307 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
308 for _ in 0..waiting_threshold_conf_len {
309 let height_target = Readable::read(reader)?;
310 let events_len: u64 = Readable::read(reader)?;
311 let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
312 for _ in 0..events_len {
313 let ev = match <u8 as Readable>::read(reader)? {
315 let claim_request = Readable::read(reader)?;
316 OnchainEvent::Claim {
321 let outpoint = Readable::read(reader)?;
322 let input_material = Readable::read(reader)?;
323 OnchainEvent::ContentiousOutpoint {
328 _ => return Err(DecodeError::InvalidValue),
332 onchain_events_waiting_threshold_conf.insert(height_target, events);
335 Ok(OnchainTxHandler {
339 prev_local_commitment,
340 prev_local_htlc_sigs,
344 pending_claim_requests,
345 onchain_events_waiting_threshold_conf,
346 secp_ctx: Secp256k1::new(),
351 impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
352 pub(super) fn new(destination_script: Script, keys: ChanSigner, local_csv: u16) -> Self {
354 let key_storage = keys;
358 local_commitment: None,
359 local_htlc_sigs: None,
360 prev_local_commitment: None,
361 prev_local_htlc_sigs: None,
364 pending_claim_requests: HashMap::new(),
365 claimable_outpoints: HashMap::new(),
366 onchain_events_waiting_threshold_conf: HashMap::new(),
368 secp_ctx: Secp256k1::new(),
372 pub(super) fn get_witnesses_weight(inputs: &[InputDescriptors]) -> usize {
373 let mut tx_weight = 2; // count segwit flags
375 // We use expected weight (and not actual) as signatures and time lock delays may vary
376 tx_weight += match inp {
377 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
378 &InputDescriptors::RevokedOfferedHTLC => {
379 1 + 1 + 73 + 1 + 33 + 1 + 133
381 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
382 &InputDescriptors::RevokedReceivedHTLC => {
383 1 + 1 + 73 + 1 + 33 + 1 + 139
385 // number_of_witness_elements + sig_length + remotehtlc_sig + preimage_length + preimage + witness_script_length + witness_script
386 &InputDescriptors::OfferedHTLC => {
387 1 + 1 + 73 + 1 + 32 + 1 + 133
389 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
390 &InputDescriptors::ReceivedHTLC => {
391 1 + 1 + 73 + 1 + 1 + 1 + 139
393 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
394 &InputDescriptors::RevokedOutput => {
395 1 + 1 + 73 + 1 + 1 + 1 + 77
402 /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
403 /// 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
404 /// height than once reached we should generate a new bumped "version" of the claim tx to be sure than we safely claim outputs before
405 /// than our counterparty can do it too. If timelock expires soon, height timer is going to be scale down in consequence to increase
406 /// frequency of the bump and so increase our bets of success.
407 fn get_height_timer(current_height: u32, timelock_expiration: u32) -> u32 {
408 if timelock_expiration <= current_height + 3 {
409 return current_height + 1
410 } else if timelock_expiration - current_height <= 15 {
411 return current_height + 3
416 /// 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
417 /// (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.
418 fn generate_claim_tx<F: Deref, L: Deref>(&mut self, height: u32, cached_claim_datas: &ClaimTxBumpMaterial, fee_estimator: F, logger: L) -> Option<(Option<u32>, u64, Transaction)>
419 where F::Target: FeeEstimator,
422 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
423 let mut inputs = Vec::new();
424 for outp in cached_claim_datas.per_input_material.keys() {
425 log_trace!(logger, "Outpoint {}:{}", outp.txid, outp.vout);
427 previous_output: *outp,
428 script_sig: Script::new(),
429 sequence: 0xfffffffd,
433 let mut bumped_tx = Transaction {
438 script_pubkey: self.destination_script.clone(),
443 macro_rules! RBF_bump {
444 ($amount: expr, $old_feerate: expr, $fee_estimator: expr, $predicted_weight: expr) => {
446 let mut used_feerate;
447 // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
448 let new_fee = if $old_feerate < $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) {
449 let mut value = $amount;
450 if subtract_high_prio_fee!(logger, $fee_estimator, value, $predicted_weight, used_feerate) {
451 // Overflow check is done in subtract_high_prio_fee
454 log_trace!(logger, "Can't new-estimation bump new claiming tx, amount {} is too small", $amount);
457 // ...else just increase the previous feerate by 25% (because that's a nice number)
459 let fee = $old_feerate * $predicted_weight / 750;
461 log_trace!(logger, "Can't 25% bump new claiming tx, amount {} is too small", $amount);
467 let previous_fee = $old_feerate * $predicted_weight / 1000;
468 let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * $predicted_weight / 1000;
469 // BIP 125 Opt-in Full Replace-by-Fee Signaling
470 // * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
471 // * 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.
472 let new_fee = if new_fee < previous_fee + min_relay_fee {
473 new_fee + previous_fee + min_relay_fee - new_fee
477 Some((new_fee, new_fee * 1000 / $predicted_weight))
482 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
483 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
484 let new_timer = Some(Self::get_height_timer(height, cached_claim_datas.soonest_timelock));
485 let mut inputs_witnesses_weight = 0;
487 let mut dynamic_fee = true;
488 for per_outp_material in cached_claim_datas.per_input_material.values() {
489 match per_outp_material {
490 &InputMaterial::Revoked { ref witness_script, ref is_htlc, ref amount, .. } => {
491 inputs_witnesses_weight += Self::get_witnesses_weight(if !is_htlc { &[InputDescriptors::RevokedOutput] } else if HTLCType::scriptlen_to_htlctype(witness_script.len()) == Some(HTLCType::OfferedHTLC) { &[InputDescriptors::RevokedOfferedHTLC] } else if HTLCType::scriptlen_to_htlctype(witness_script.len()) == Some(HTLCType::AcceptedHTLC) { &[InputDescriptors::RevokedReceivedHTLC] } else { unreachable!() });
494 &InputMaterial::RemoteHTLC { ref preimage, ref amount, .. } => {
495 inputs_witnesses_weight += Self::get_witnesses_weight(if preimage.is_some() { &[InputDescriptors::OfferedHTLC] } else { &[InputDescriptors::ReceivedHTLC] });
498 &InputMaterial::LocalHTLC { .. } => {
501 &InputMaterial::Funding { .. } => {
507 let predicted_weight = bumped_tx.get_weight() + inputs_witnesses_weight;
509 // If old feerate is 0, first iteration of this claim, use normal fee calculation
510 if cached_claim_datas.feerate_previous != 0 {
511 if let Some((new_fee, feerate)) = RBF_bump!(amt, cached_claim_datas.feerate_previous, fee_estimator, predicted_weight as u64) {
512 // If new computed fee is superior at the whole claimable amount burn all in fees
514 bumped_tx.output[0].value = 0;
516 bumped_tx.output[0].value = amt - new_fee;
518 new_feerate = feerate;
519 } else { return None; }
521 if subtract_high_prio_fee!(logger, fee_estimator, amt, predicted_weight, new_feerate) {
522 bumped_tx.output[0].value = amt;
523 } else { return None; }
525 assert!(new_feerate != 0);
527 for (i, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
528 match per_outp_material {
529 &InputMaterial::Revoked { ref witness_script, ref pubkey, ref key, ref is_htlc, ref amount } => {
530 let sighash_parts = bip143::SighashComponents::new(&bumped_tx);
531 let sighash = hash_to_message!(&sighash_parts.sighash_all(&bumped_tx.input[i], &witness_script, *amount)[..]);
532 let sig = self.secp_ctx.sign(&sighash, &key);
533 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
534 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
536 bumped_tx.input[i].witness.push(pubkey.unwrap().clone().serialize().to_vec());
538 bumped_tx.input[i].witness.push(vec!(1));
540 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
541 log_trace!(logger, "Going to broadcast Penalty Transaction {} claiming revoked {} output {} from {} with new feerate {}...", bumped_tx.txid(), if !is_htlc { "to_local" } else if HTLCType::scriptlen_to_htlctype(witness_script.len()) == Some(HTLCType::OfferedHTLC) { "offered" } else if HTLCType::scriptlen_to_htlctype(witness_script.len()) == Some(HTLCType::AcceptedHTLC) { "received" } else { "" }, outp.vout, outp.txid, new_feerate);
543 &InputMaterial::RemoteHTLC { ref witness_script, ref key, ref preimage, ref amount, ref locktime } => {
544 if !preimage.is_some() { bumped_tx.lock_time = *locktime }; // Right now we don't aggregate time-locked transaction, if we do we should set lock_time before to avoid breaking hash computation
545 let sighash_parts = bip143::SighashComponents::new(&bumped_tx);
546 let sighash = hash_to_message!(&sighash_parts.sighash_all(&bumped_tx.input[i], &witness_script, *amount)[..]);
547 let sig = self.secp_ctx.sign(&sighash, &key);
548 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
549 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
550 if let &Some(preimage) = preimage {
551 bumped_tx.input[i].witness.push(preimage.clone().0.to_vec());
553 bumped_tx.input[i].witness.push(vec![]);
555 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
556 log_trace!(logger, "Going to broadcast Claim Transaction {} claiming remote {} htlc output {} from {} with new feerate {}...", bumped_tx.txid(), if preimage.is_some() { "offered" } else { "received" }, outp.vout, outp.txid, new_feerate);
561 log_trace!(logger, "...with timer {}", new_timer.unwrap());
562 assert!(predicted_weight >= bumped_tx.get_weight());
563 return Some((new_timer, new_feerate, bumped_tx))
565 for (_, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
566 match per_outp_material {
567 &InputMaterial::LocalHTLC { ref preimage, ref amount } => {
568 let htlc_tx = self.get_fully_signed_htlc_tx(outp, preimage);
569 if let Some(htlc_tx) = htlc_tx {
570 let feerate = (amount - htlc_tx.output[0].value) * 1000 / htlc_tx.get_weight() as u64;
571 // Timer set to $NEVER given we can't bump tx without anchor outputs
572 log_trace!(logger, "Going to broadcast Local HTLC-{} claiming HTLC output {} from {}...", if preimage.is_some() { "Success" } else { "Timeout" }, outp.vout, outp.txid);
573 return Some((None, feerate, htlc_tx));
577 &InputMaterial::Funding { ref funding_redeemscript } => {
578 let signed_tx = self.get_fully_signed_local_tx(funding_redeemscript).unwrap();
579 // Timer set to $NEVER given we can't bump tx without anchor outputs
580 log_trace!(logger, "Going to broadcast Local Transaction {} claiming funding output {} from {}...", signed_tx.txid(), outp.vout, outp.txid);
581 return Some((None, self.local_commitment.as_ref().unwrap().feerate_per_kw, signed_tx));
590 pub(super) fn block_connected<B: Deref, F: Deref, L: Deref>(&mut self, txn_matched: &[&Transaction], claimable_outpoints: Vec<ClaimRequest>, height: u32, broadcaster: B, fee_estimator: F, logger: L)
591 where B::Target: BroadcasterInterface,
592 F::Target: FeeEstimator,
595 log_trace!(logger, "Block at height {} connected with {} claim requests", height, claimable_outpoints.len());
596 let mut new_claims = Vec::new();
597 let mut aggregated_claim = HashMap::new();
598 let mut aggregated_soonest = ::std::u32::MAX;
600 // Try to aggregate outputs if their timelock expiration isn't imminent (absolute_timelock
601 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
602 for req in claimable_outpoints {
603 // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
604 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 {
605 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.absolute_timelock, height + CLTV_SHARED_CLAIM_BUFFER);
606 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
607 let mut single_input = HashMap::new();
608 single_input.insert(req.outpoint, req.witness_data);
609 new_claims.push((req.absolute_timelock, single_input));
611 aggregated_claim.insert(req.outpoint, req.witness_data);
612 if req.absolute_timelock < aggregated_soonest {
613 aggregated_soonest = req.absolute_timelock;
618 new_claims.push((aggregated_soonest, aggregated_claim));
620 // Generate claim transactions and track them to bump if necessary at
621 // height timer expiration (i.e in how many blocks we're going to take action).
622 for (soonest_timelock, claim) in new_claims.drain(..) {
623 let mut claim_material = ClaimTxBumpMaterial { height_timer: None, feerate_previous: 0, soonest_timelock, per_input_material: claim };
624 if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
625 claim_material.height_timer = new_timer;
626 claim_material.feerate_previous = new_feerate;
627 let txid = tx.txid();
628 for k in claim_material.per_input_material.keys() {
629 log_trace!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
630 self.claimable_outpoints.insert(k.clone(), (txid, height));
632 self.pending_claim_requests.insert(txid, claim_material);
633 log_trace!(logger, "Broadcast onchain {}", log_tx!(tx));
634 broadcaster.broadcast_transaction(&tx);
638 let mut bump_candidates = HashMap::new();
639 for tx in txn_matched {
640 // Scan all input to verify is one of the outpoint spent is of interest for us
641 let mut claimed_outputs_material = Vec::new();
642 for inp in &tx.input {
643 if let Some(first_claim_txid_height) = self.claimable_outpoints.get(&inp.previous_output) {
644 // If outpoint has claim request pending on it...
645 if let Some(claim_material) = self.pending_claim_requests.get_mut(&first_claim_txid_height.0) {
646 //... we need to verify equality between transaction outpoints and claim request
647 // outpoints to know if transaction is the original claim or a bumped one issued
649 let mut set_equality = true;
650 if claim_material.per_input_material.len() != tx.input.len() {
651 set_equality = false;
653 for (claim_inp, tx_inp) in claim_material.per_input_material.keys().zip(tx.input.iter()) {
654 if *claim_inp != tx_inp.previous_output {
655 set_equality = false;
660 macro_rules! clean_claim_request_after_safety_delay {
662 let new_event = OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() };
663 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
664 hash_map::Entry::Occupied(mut entry) => {
665 if !entry.get().contains(&new_event) {
666 entry.get_mut().push(new_event);
669 hash_map::Entry::Vacant(entry) => {
670 entry.insert(vec![new_event]);
676 // If this is our transaction (or our counterparty spent all the outputs
677 // before we could anyway with same inputs order than us), wait for
678 // ANTI_REORG_DELAY and clean the RBF tracking map.
680 clean_claim_request_after_safety_delay!();
681 } else { // If false, generate new claim request with update outpoint set
682 let mut at_least_one_drop = false;
683 for input in tx.input.iter() {
684 if let Some(input_material) = claim_material.per_input_material.remove(&input.previous_output) {
685 claimed_outputs_material.push((input.previous_output, input_material));
686 at_least_one_drop = true;
688 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
689 if claim_material.per_input_material.is_empty() {
690 clean_claim_request_after_safety_delay!();
693 //TODO: recompute soonest_timelock to avoid wasting a bit on fees
694 if at_least_one_drop {
695 bump_candidates.insert(first_claim_txid_height.0.clone(), claim_material.clone());
698 break; //No need to iterate further, either tx is our or their
700 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
704 for (outpoint, input_material) in claimed_outputs_material.drain(..) {
705 let new_event = OnchainEvent::ContentiousOutpoint { outpoint, input_material };
706 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
707 hash_map::Entry::Occupied(mut entry) => {
708 if !entry.get().contains(&new_event) {
709 entry.get_mut().push(new_event);
712 hash_map::Entry::Vacant(entry) => {
713 entry.insert(vec![new_event]);
719 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
720 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
723 OnchainEvent::Claim { claim_request } => {
724 // We may remove a whole set of claim outpoints here, as these one may have
725 // been aggregated in a single tx and claimed so atomically
726 if let Some(bump_material) = self.pending_claim_requests.remove(&claim_request) {
727 for outpoint in bump_material.per_input_material.keys() {
728 self.claimable_outpoints.remove(&outpoint);
732 OnchainEvent::ContentiousOutpoint { outpoint, .. } => {
733 self.claimable_outpoints.remove(&outpoint);
739 // Check if any pending claim request must be rescheduled
740 for (first_claim_txid, ref claim_data) in self.pending_claim_requests.iter() {
741 if let Some(h) = claim_data.height_timer {
743 bump_candidates.insert(*first_claim_txid, (*claim_data).clone());
748 // Build, bump and rebroadcast tx accordingly
749 log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
750 for (first_claim_txid, claim_material) in bump_candidates.iter() {
751 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
752 log_trace!(logger, "Broadcast onchain {}", log_tx!(bump_tx));
753 broadcaster.broadcast_transaction(&bump_tx);
754 if let Some(claim_material) = self.pending_claim_requests.get_mut(first_claim_txid) {
755 claim_material.height_timer = new_timer;
756 claim_material.feerate_previous = new_feerate;
762 pub(super) fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: F, logger: L)
763 where B::Target: BroadcasterInterface,
764 F::Target: FeeEstimator,
767 let mut bump_candidates = HashMap::new();
768 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
769 //- our claim tx on a commitment tx output
770 //- resurect outpoint back in its claimable set and regenerate tx
773 OnchainEvent::ContentiousOutpoint { outpoint, input_material } => {
774 if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&outpoint) {
775 if let Some(claim_material) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) {
776 claim_material.per_input_material.insert(outpoint, input_material);
777 // Using a HashMap guarantee us than if we have multiple outpoints getting
778 // resurrected only one bump claim tx is going to be broadcast
779 bump_candidates.insert(ancestor_claimable_txid.clone(), claim_material.clone());
787 for (_, claim_material) in bump_candidates.iter_mut() {
788 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
789 claim_material.height_timer = new_timer;
790 claim_material.feerate_previous = new_feerate;
791 broadcaster.broadcast_transaction(&bump_tx);
794 for (ancestor_claim_txid, claim_material) in bump_candidates.drain() {
795 self.pending_claim_requests.insert(ancestor_claim_txid.0, claim_material);
797 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
798 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
799 let mut remove_request = Vec::new();
800 self.claimable_outpoints.retain(|_, ref v|
802 remove_request.push(v.0.clone());
805 for req in remove_request {
806 self.pending_claim_requests.remove(&req);
810 pub(super) fn provide_latest_local_tx(&mut self, tx: LocalCommitmentTransaction) -> Result<(), ()> {
811 // To prevent any unsafe state discrepancy between offchain and onchain, once local
812 // commitment transaction has been signed due to an event (either block height for
813 // HTLC-timeout or channel force-closure), don't allow any further update of local
814 // commitment transaction view to avoid delivery of revocation secret to counterparty
815 // for the aformentionned signed transaction.
816 if self.local_htlc_sigs.is_some() || self.prev_local_htlc_sigs.is_some() {
819 self.prev_local_commitment = self.local_commitment.take();
820 self.local_commitment = Some(tx);
824 fn sign_latest_local_htlcs(&mut self) {
825 if let Some(ref local_commitment) = self.local_commitment {
826 if let Ok(sigs) = self.key_storage.sign_local_commitment_htlc_transactions(local_commitment, self.local_csv, &self.secp_ctx) {
827 self.local_htlc_sigs = Some(Vec::new());
828 let ret = self.local_htlc_sigs.as_mut().unwrap();
829 for (htlc_idx, (local_sig, &(ref htlc, _))) in sigs.iter().zip(local_commitment.per_htlc.iter()).enumerate() {
830 if let Some(tx_idx) = htlc.transaction_output_index {
831 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
832 ret[tx_idx as usize] = Some((htlc_idx, local_sig.expect("Did not receive a signature for a non-dust HTLC")));
834 assert!(local_sig.is_none(), "Received a signature for a dust HTLC");
840 fn sign_prev_local_htlcs(&mut self) {
841 if let Some(ref local_commitment) = self.prev_local_commitment {
842 if let Ok(sigs) = self.key_storage.sign_local_commitment_htlc_transactions(local_commitment, self.local_csv, &self.secp_ctx) {
843 self.prev_local_htlc_sigs = Some(Vec::new());
844 let ret = self.prev_local_htlc_sigs.as_mut().unwrap();
845 for (htlc_idx, (local_sig, &(ref htlc, _))) in sigs.iter().zip(local_commitment.per_htlc.iter()).enumerate() {
846 if let Some(tx_idx) = htlc.transaction_output_index {
847 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
848 ret[tx_idx as usize] = Some((htlc_idx, local_sig.expect("Did not receive a signature for a non-dust HTLC")));
850 assert!(local_sig.is_none(), "Received a signature for a dust HTLC");
857 //TODO: getting lastest local transactions should be infaillible and result in us "force-closing the channel", but we may
858 // have empty local commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
859 // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
860 // to monitor before.
861 pub(super) fn get_fully_signed_local_tx(&mut self, funding_redeemscript: &Script) -> Option<Transaction> {
862 if let Some(ref mut local_commitment) = self.local_commitment {
863 match self.key_storage.sign_local_commitment(local_commitment, &self.secp_ctx) {
864 Ok(sig) => Some(local_commitment.add_local_sig(funding_redeemscript, sig)),
865 Err(_) => return None,
873 pub(super) fn get_fully_signed_copy_local_tx(&mut self, funding_redeemscript: &Script) -> Option<Transaction> {
874 if let Some(ref mut local_commitment) = self.local_commitment {
875 let local_commitment = local_commitment.clone();
876 match self.key_storage.sign_local_commitment(&local_commitment, &self.secp_ctx) {
877 Ok(sig) => Some(local_commitment.add_local_sig(funding_redeemscript, sig)),
878 Err(_) => return None,
885 pub(super) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
886 let mut htlc_tx = None;
887 if self.local_commitment.is_some() {
888 let commitment_txid = self.local_commitment.as_ref().unwrap().txid();
889 if commitment_txid == outp.txid {
890 self.sign_latest_local_htlcs();
891 if let &Some(ref htlc_sigs) = &self.local_htlc_sigs {
892 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
893 htlc_tx = Some(self.local_commitment.as_ref().unwrap()
894 .get_signed_htlc_tx(*htlc_idx, htlc_sig, preimage, self.local_csv));
898 if self.prev_local_commitment.is_some() {
899 let commitment_txid = self.prev_local_commitment.as_ref().unwrap().txid();
900 if commitment_txid == outp.txid {
901 self.sign_prev_local_htlcs();
902 if let &Some(ref htlc_sigs) = &self.prev_local_htlc_sigs {
903 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
904 htlc_tx = Some(self.prev_local_commitment.as_ref().unwrap()
905 .get_signed_htlc_tx(*htlc_idx, htlc_sig, preimage, self.local_csv));
913 pub(super) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
914 let latest_had_sigs = self.local_htlc_sigs.is_some();
915 let prev_had_sigs = self.prev_local_htlc_sigs.is_some();
916 let ret = self.get_fully_signed_htlc_tx(outp, preimage);
917 if !latest_had_sigs {
918 self.local_htlc_sigs = None;
921 self.prev_local_htlc_sigs = None;