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_hashes::sha256d::Hash as Sha256dHash;
13 use secp256k1::Secp256k1;
16 use ln::msgs::DecodeError;
17 use ln::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER, InputMaterial, ClaimRequest};
18 use ln::chan_utils::HTLCType;
19 use chain::chaininterface::{FeeEstimator, BroadcasterInterface, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT};
20 use chain::keysinterface::ChannelKeys;
21 use util::logger::Logger;
22 use util::ser::{ReadableArgs, Readable, Writer, Writeable};
25 use std::collections::{HashMap, hash_map, HashSet};
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.
39 claim_request: Sha256dHash,
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.
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 writer.write_all(&byte_utils::be32_to_array(self.height_timer))?;
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 ($self: 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!($self, "Failed to generate an on-chain punishment tx as even low priority fee ({} sat) was more than the entire claim balance ({} sat)",
120 log_warn!($self, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
126 log_warn!($self, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
140 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
141 /// do RBF bumping if possible.
142 pub struct OnchainTxHandler<ChanSigner: ChannelKeys> {
143 destination_script: Script,
144 funding_redeemscript: Script,
146 key_storage: ChanSigner,
148 // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
149 // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
150 // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
151 // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
152 // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
153 // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
154 // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
155 // we need to regenerate new claim request with reduced set of still-claimable outpoints.
156 // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
157 // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
158 // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
159 #[cfg(test)] // Used in functional_test to verify sanitization
160 pub pending_claim_requests: HashMap<Sha256dHash, ClaimTxBumpMaterial>,
162 pending_claim_requests: HashMap<Sha256dHash, ClaimTxBumpMaterial>,
164 // Used to link outpoints claimed in a connected block to a pending claim request.
165 // Key is outpoint than monitor parsing has detected we have keys/scripts to claim
166 // Value is (pending claim request identifier, confirmation_block), identifier
167 // is txid of the initial claiming transaction and is immutable until outpoint is
168 // post-anti-reorg-delay solved, confirmaiton_block is used to erase entry if
169 // block with output gets disconnected.
170 #[cfg(test)] // Used in functional_test to verify sanitization
171 pub claimable_outpoints: HashMap<BitcoinOutPoint, (Sha256dHash, u32)>,
173 claimable_outpoints: HashMap<BitcoinOutPoint, (Sha256dHash, u32)>,
175 onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
177 secp_ctx: Secp256k1<secp256k1::All>,
181 impl<ChanSigner: ChannelKeys + Writeable> OnchainTxHandler<ChanSigner> {
182 pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
183 self.destination_script.write(writer)?;
184 self.funding_redeemscript.write(writer)?;
186 self.key_storage.write(writer)?;
188 writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
189 for (ref ancestor_claim_txid, claim_tx_data) in self.pending_claim_requests.iter() {
190 ancestor_claim_txid.write(writer)?;
191 claim_tx_data.write(writer)?;
194 writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
195 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
197 claim_and_height.0.write(writer)?;
198 claim_and_height.1.write(writer)?;
201 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
202 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
203 writer.write_all(&byte_utils::be32_to_array(**target))?;
204 writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
205 for ev in events.iter() {
207 OnchainEvent::Claim { ref claim_request } => {
208 writer.write_all(&[0; 1])?;
209 claim_request.write(writer)?;
211 OnchainEvent::ContentiousOutpoint { ref outpoint, ref input_material } => {
212 writer.write_all(&[1; 1])?;
213 outpoint.write(writer)?;
214 input_material.write(writer)?;
223 impl<ChanSigner: ChannelKeys + Readable> ReadableArgs<Arc<Logger>> for OnchainTxHandler<ChanSigner> {
224 fn read<R: ::std::io::Read>(reader: &mut R, logger: Arc<Logger>) -> Result<Self, DecodeError> {
225 let destination_script = Readable::read(reader)?;
226 let funding_redeemscript = Readable::read(reader)?;
228 let key_storage = Readable::read(reader)?;
230 let pending_claim_requests_len: u64 = Readable::read(reader)?;
231 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
232 for _ in 0..pending_claim_requests_len {
233 pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
236 let claimable_outpoints_len: u64 = Readable::read(reader)?;
237 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
238 for _ in 0..claimable_outpoints_len {
239 let outpoint = Readable::read(reader)?;
240 let ancestor_claim_txid = Readable::read(reader)?;
241 let height = Readable::read(reader)?;
242 claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
244 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
245 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
246 for _ in 0..waiting_threshold_conf_len {
247 let height_target = Readable::read(reader)?;
248 let events_len: u64 = Readable::read(reader)?;
249 let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
250 for _ in 0..events_len {
251 let ev = match <u8 as Readable>::read(reader)? {
253 let claim_request = Readable::read(reader)?;
254 OnchainEvent::Claim {
259 let outpoint = Readable::read(reader)?;
260 let input_material = Readable::read(reader)?;
261 OnchainEvent::ContentiousOutpoint {
266 _ => return Err(DecodeError::InvalidValue),
270 onchain_events_waiting_threshold_conf.insert(height_target, events);
273 Ok(OnchainTxHandler {
275 funding_redeemscript,
278 pending_claim_requests,
279 onchain_events_waiting_threshold_conf,
280 secp_ctx: Secp256k1::new(),
286 impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
287 pub(super) fn new(destination_script: Script, keys: ChanSigner, funding_redeemscript: Script, logger: Arc<Logger>) -> Self {
289 let key_storage = keys;
293 funding_redeemscript,
295 pending_claim_requests: HashMap::new(),
296 claimable_outpoints: HashMap::new(),
297 onchain_events_waiting_threshold_conf: HashMap::new(),
299 secp_ctx: Secp256k1::new(),
304 pub(super) fn get_witnesses_weight(inputs: &[InputDescriptors]) -> usize {
305 let mut tx_weight = 2; // count segwit flags
307 // We use expected weight (and not actual) as signatures and time lock delays may vary
308 tx_weight += match inp {
309 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
310 &InputDescriptors::RevokedOfferedHTLC => {
311 1 + 1 + 73 + 1 + 33 + 1 + 133
313 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
314 &InputDescriptors::RevokedReceivedHTLC => {
315 1 + 1 + 73 + 1 + 33 + 1 + 139
317 // number_of_witness_elements + sig_length + remotehtlc_sig + preimage_length + preimage + witness_script_length + witness_script
318 &InputDescriptors::OfferedHTLC => {
319 1 + 1 + 73 + 1 + 32 + 1 + 133
321 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
322 &InputDescriptors::ReceivedHTLC => {
323 1 + 1 + 73 + 1 + 1 + 1 + 139
325 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
326 &InputDescriptors::RevokedOutput => {
327 1 + 1 + 73 + 1 + 1 + 1 + 77
334 /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
335 /// 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
336 /// height than once reached we should generate a new bumped "version" of the claim tx to be sure than we safely claim outputs before
337 /// than our counterparty can do it too. If timelock expires soon, height timer is going to be scale down in consequence to increase
338 /// frequency of the bump and so increase our bets of success.
339 fn get_height_timer(current_height: u32, timelock_expiration: u32) -> u32 {
340 if timelock_expiration <= current_height + 3 {
341 return current_height + 1
342 } else if timelock_expiration - current_height <= 15 {
343 return current_height + 3
348 /// 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
349 /// (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.
350 fn generate_claim_tx<F: Deref>(&self, height: u32, cached_claim_datas: &ClaimTxBumpMaterial, fee_estimator: F) -> Option<(u32, u64, Transaction)>
351 where F::Target: FeeEstimator
353 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
354 let mut inputs = Vec::new();
355 for outp in cached_claim_datas.per_input_material.keys() {
356 log_trace!(self, "Outpoint {}:{}", outp.txid, outp.vout);
358 previous_output: *outp,
359 script_sig: Script::new(),
360 sequence: 0xfffffffd,
364 let mut bumped_tx = Transaction {
369 script_pubkey: self.destination_script.clone(),
374 macro_rules! RBF_bump {
375 ($amount: expr, $old_feerate: expr, $fee_estimator: expr, $predicted_weight: expr) => {
377 let mut used_feerate;
378 // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
379 let new_fee = if $old_feerate < $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) {
380 let mut value = $amount;
381 if subtract_high_prio_fee!(self, $fee_estimator, value, $predicted_weight, used_feerate) {
382 // Overflow check is done in subtract_high_prio_fee
385 log_trace!(self, "Can't new-estimation bump new claiming tx, amount {} is too small", $amount);
388 // ...else just increase the previous feerate by 25% (because that's a nice number)
390 let fee = $old_feerate * $predicted_weight / 750;
392 log_trace!(self, "Can't 25% bump new claiming tx, amount {} is too small", $amount);
398 let previous_fee = $old_feerate * $predicted_weight / 1000;
399 let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * $predicted_weight / 1000;
400 // BIP 125 Opt-in Full Replace-by-Fee Signaling
401 // * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
402 // * 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.
403 let new_fee = if new_fee < previous_fee + min_relay_fee {
404 new_fee + previous_fee + min_relay_fee - new_fee
408 Some((new_fee, new_fee * 1000 / $predicted_weight))
413 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
414 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
415 let new_timer = Self::get_height_timer(height, cached_claim_datas.soonest_timelock);
416 let mut inputs_witnesses_weight = 0;
418 for per_outp_material in cached_claim_datas.per_input_material.values() {
419 match per_outp_material {
420 &InputMaterial::Revoked { ref witness_script, ref is_htlc, ref amount, .. } => {
421 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!() });
424 &InputMaterial::RemoteHTLC { ref preimage, ref amount, .. } => {
425 inputs_witnesses_weight += Self::get_witnesses_weight(if preimage.is_some() { &[InputDescriptors::OfferedHTLC] } else { &[InputDescriptors::ReceivedHTLC] });
428 &InputMaterial::LocalHTLC { .. } => { return None; }
432 let predicted_weight = bumped_tx.get_weight() + inputs_witnesses_weight;
434 // If old feerate is 0, first iteration of this claim, use normal fee calculation
435 if cached_claim_datas.feerate_previous != 0 {
436 if let Some((new_fee, feerate)) = RBF_bump!(amt, cached_claim_datas.feerate_previous, fee_estimator, predicted_weight as u64) {
437 // If new computed fee is superior at the whole claimable amount burn all in fees
439 bumped_tx.output[0].value = 0;
441 bumped_tx.output[0].value = amt - new_fee;
443 new_feerate = feerate;
444 } else { return None; }
446 if subtract_high_prio_fee!(self, fee_estimator, amt, predicted_weight, new_feerate) {
447 bumped_tx.output[0].value = amt;
448 } else { return None; }
450 assert!(new_feerate != 0);
452 for (i, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
453 match per_outp_material {
454 &InputMaterial::Revoked { ref witness_script, ref pubkey, ref key, ref is_htlc, ref amount } => {
455 let sighash_parts = bip143::SighashComponents::new(&bumped_tx);
456 let sighash = hash_to_message!(&sighash_parts.sighash_all(&bumped_tx.input[i], &witness_script, *amount)[..]);
457 let sig = self.secp_ctx.sign(&sighash, &key);
458 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
459 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
461 bumped_tx.input[i].witness.push(pubkey.unwrap().clone().serialize().to_vec());
463 bumped_tx.input[i].witness.push(vec!(1));
465 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
466 log_trace!(self, "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);
468 &InputMaterial::RemoteHTLC { ref witness_script, ref key, ref preimage, ref amount, ref locktime } => {
469 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
470 let sighash_parts = bip143::SighashComponents::new(&bumped_tx);
471 let sighash = hash_to_message!(&sighash_parts.sighash_all(&bumped_tx.input[i], &witness_script, *amount)[..]);
472 let sig = self.secp_ctx.sign(&sighash, &key);
473 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
474 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
475 if let &Some(preimage) = preimage {
476 bumped_tx.input[i].witness.push(preimage.clone().0.to_vec());
478 bumped_tx.input[i].witness.push(vec![]);
480 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
481 log_trace!(self, "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);
483 &InputMaterial::LocalHTLC { .. } => {
484 //TODO : Given that Local Commitment Transaction and HTLC-Timeout/HTLC-Success are counter-signed by peer, we can't
485 // RBF them. Need a Lightning specs change and package relay modification :
486 // https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2018-November/016518.html
491 log_trace!(self, "...with timer {}", new_timer);
492 assert!(predicted_weight >= bumped_tx.get_weight());
493 Some((new_timer, new_feerate, bumped_tx))
496 pub(super) fn block_connected<B: Deref, F: Deref>(&mut self, txn_matched: &[&Transaction], claimable_outpoints: Vec<ClaimRequest>, height: u32, broadcaster: B, fee_estimator: F)
497 where B::Target: BroadcasterInterface,
498 F::Target: FeeEstimator
500 log_trace!(self, "Block at height {} connected with {} claim requests", height, claimable_outpoints.len());
501 let mut new_claims = Vec::new();
502 let mut aggregated_claim = HashMap::new();
503 let mut aggregated_soonest = ::std::u32::MAX;
505 // Try to aggregate outputs if their timelock expiration isn't imminent (absolute_timelock
506 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
507 for req in claimable_outpoints {
508 // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
509 if let Some(_) = self.claimable_outpoints.get(&req.outpoint) { log_trace!(self, "Bouncing off outpoint {}:{}, already registered its claiming request", req.outpoint.txid, req.outpoint.vout); } else {
510 log_trace!(self, "Test if outpoint can be aggregated with expiration {} against {}", req.absolute_timelock, height + CLTV_SHARED_CLAIM_BUFFER);
511 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
512 let mut single_input = HashMap::new();
513 single_input.insert(req.outpoint, req.witness_data);
514 new_claims.push((req.absolute_timelock, single_input));
516 aggregated_claim.insert(req.outpoint, req.witness_data);
517 if req.absolute_timelock < aggregated_soonest {
518 aggregated_soonest = req.absolute_timelock;
523 new_claims.push((aggregated_soonest, aggregated_claim));
525 // Generate claim transactions and track them to bump if necessary at
526 // height timer expiration (i.e in how many blocks we're going to take action).
527 for claim in new_claims {
528 let mut claim_material = ClaimTxBumpMaterial { height_timer: 0, feerate_previous: 0, soonest_timelock: claim.0, per_input_material: claim.1.clone() };
529 if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator) {
530 claim_material.height_timer = new_timer;
531 claim_material.feerate_previous = new_feerate;
532 let txid = tx.txid();
533 self.pending_claim_requests.insert(txid, claim_material);
534 for k in claim.1.keys() {
535 log_trace!(self, "Registering claiming request for {}:{}", k.txid, k.vout);
536 self.claimable_outpoints.insert(k.clone(), (txid, height));
538 log_trace!(self, "Broadcast onchain {}", log_tx!(tx));
539 broadcaster.broadcast_transaction(&tx);
543 let mut bump_candidates = HashSet::new();
544 for tx in txn_matched {
545 // Scan all input to verify is one of the outpoint spent is of interest for us
546 let mut claimed_outputs_material = Vec::new();
547 for inp in &tx.input {
548 if let Some(first_claim_txid_height) = self.claimable_outpoints.get(&inp.previous_output) {
549 // If outpoint has claim request pending on it...
550 if let Some(claim_material) = self.pending_claim_requests.get_mut(&first_claim_txid_height.0) {
551 //... we need to verify equality between transaction outpoints and claim request
552 // outpoints to know if transaction is the original claim or a bumped one issued
554 let mut set_equality = true;
555 if claim_material.per_input_material.len() != tx.input.len() {
556 set_equality = false;
558 for (claim_inp, tx_inp) in claim_material.per_input_material.keys().zip(tx.input.iter()) {
559 if *claim_inp != tx_inp.previous_output {
560 set_equality = false;
565 macro_rules! clean_claim_request_after_safety_delay {
567 let new_event = OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() };
568 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
569 hash_map::Entry::Occupied(mut entry) => {
570 if !entry.get().contains(&new_event) {
571 entry.get_mut().push(new_event);
574 hash_map::Entry::Vacant(entry) => {
575 entry.insert(vec![new_event]);
581 // If this is our transaction (or our counterparty spent all the outputs
582 // before we could anyway with same inputs order than us), wait for
583 // ANTI_REORG_DELAY and clean the RBF tracking map.
585 clean_claim_request_after_safety_delay!();
586 } else { // If false, generate new claim request with update outpoint set
587 let mut at_least_one_drop = false;
588 for input in tx.input.iter() {
589 if let Some(input_material) = claim_material.per_input_material.remove(&input.previous_output) {
590 claimed_outputs_material.push((input.previous_output, input_material));
591 at_least_one_drop = true;
593 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
594 if claim_material.per_input_material.is_empty() {
595 clean_claim_request_after_safety_delay!();
598 //TODO: recompute soonest_timelock to avoid wasting a bit on fees
599 if at_least_one_drop {
600 bump_candidates.insert(first_claim_txid_height.0.clone());
603 break; //No need to iterate further, either tx is our or their
605 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
609 for (outpoint, input_material) in claimed_outputs_material.drain(..) {
610 let new_event = OnchainEvent::ContentiousOutpoint { outpoint, input_material };
611 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
612 hash_map::Entry::Occupied(mut entry) => {
613 if !entry.get().contains(&new_event) {
614 entry.get_mut().push(new_event);
617 hash_map::Entry::Vacant(entry) => {
618 entry.insert(vec![new_event]);
624 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
625 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
628 OnchainEvent::Claim { claim_request } => {
629 // We may remove a whole set of claim outpoints here, as these one may have
630 // been aggregated in a single tx and claimed so atomically
631 if let Some(bump_material) = self.pending_claim_requests.remove(&claim_request) {
632 for outpoint in bump_material.per_input_material.keys() {
633 self.claimable_outpoints.remove(&outpoint);
637 OnchainEvent::ContentiousOutpoint { outpoint, .. } => {
638 self.claimable_outpoints.remove(&outpoint);
644 // Check if any pending claim request must be rescheduled
645 for (first_claim_txid, ref claim_data) in self.pending_claim_requests.iter() {
646 if claim_data.height_timer == height {
647 bump_candidates.insert(*first_claim_txid);
651 // Build, bump and rebroadcast tx accordingly
652 log_trace!(self, "Bumping {} candidates", bump_candidates.len());
653 for first_claim_txid in bump_candidates.iter() {
654 if let Some((new_timer, new_feerate)) = {
655 if let Some(claim_material) = self.pending_claim_requests.get(first_claim_txid) {
656 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator) {
657 log_trace!(self, "Broadcast onchain {}", log_tx!(bump_tx));
658 broadcaster.broadcast_transaction(&bump_tx);
659 Some((new_timer, new_feerate))
661 } else { unreachable!(); }
663 if let Some(claim_material) = self.pending_claim_requests.get_mut(first_claim_txid) {
664 claim_material.height_timer = new_timer;
665 claim_material.feerate_previous = new_feerate;
666 } else { unreachable!(); }
671 pub(super) fn block_disconnected<B: Deref, F: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: F)
672 where B::Target: BroadcasterInterface,
673 F::Target: FeeEstimator
675 let mut bump_candidates = HashMap::new();
676 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
677 //- our claim tx on a commitment tx output
678 //- resurect outpoint back in its claimable set and regenerate tx
681 OnchainEvent::ContentiousOutpoint { outpoint, input_material } => {
682 if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&outpoint) {
683 if let Some(claim_material) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) {
684 claim_material.per_input_material.insert(outpoint, input_material);
685 // Using a HashMap guarantee us than if we have multiple outpoints getting
686 // resurrected only one bump claim tx is going to be broadcast
687 bump_candidates.insert(ancestor_claimable_txid.clone(), claim_material.clone());
695 for (_, claim_material) in bump_candidates.iter_mut() {
696 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator) {
697 claim_material.height_timer = new_timer;
698 claim_material.feerate_previous = new_feerate;
699 broadcaster.broadcast_transaction(&bump_tx);
702 for (ancestor_claim_txid, claim_material) in bump_candidates.drain() {
703 self.pending_claim_requests.insert(ancestor_claim_txid.0, claim_material);
705 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
706 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
707 let mut remove_request = Vec::new();
708 self.claimable_outpoints.retain(|_, ref v|
710 remove_request.push(v.0.clone());
713 for req in remove_request {
714 self.pending_claim_requests.remove(&req);