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};
19 use ln::chan_utils::{HTLCType, LocalCommitmentTransaction, TxCreationKeys};
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::{ReadableArgs, Readable, Writer, Writeable};
26 use std::collections::{HashMap, hash_map, HashSet};
31 const MAX_ALLOC_SIZE: usize = 64*1024;
33 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
34 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
35 #[derive(Clone, PartialEq)]
37 /// Outpoint under claim process by our own tx, once this one get enough confirmations, we remove it from
38 /// bump-txn candidate buffer.
40 claim_request: Sha256dHash,
42 /// Claim tx aggregate multiple claimable outpoints. One of the outpoint may be claimed by a remote party tx.
43 /// In this case, we need to drop the outpoint and regenerate a new claim tx. By safety, we keep tracking
44 /// the outpoint to be sure to resurect it back to the claim tx if reorgs happen.
46 outpoint: BitcoinOutPoint,
47 input_material: InputMaterial,
51 /// Cache public keys and feerate used to compute any HTLC transaction.
52 /// We only keep state for latest 2 commitment transactions as we should
53 /// never have to generate HTLC txn for revoked local commitment
55 local_keys: TxCreationKeys,
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: u64,
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::be64_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 })
105 pub(super) enum InputDescriptors {
110 RevokedOutput, // either a revoked to_local output on commitment tx, a revoked HTLC-Timeout output or a revoked HTLC-Success output
113 macro_rules! subtract_high_prio_fee {
114 ($self: ident, $fee_estimator: expr, $value: expr, $predicted_weight: expr, $used_feerate: expr) => {
116 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority);
117 let mut fee = $used_feerate * ($predicted_weight as u64) / 1000;
119 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);
120 fee = $used_feerate * ($predicted_weight as u64) / 1000;
122 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
123 fee = $used_feerate * ($predicted_weight as u64) / 1000;
125 log_error!($self, "Failed to generate an on-chain punishment tx as even low priority fee ({} sat) was more than the entire claim balance ({} sat)",
129 log_warn!($self, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
135 log_warn!($self, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
149 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
150 /// do RBF bumping if possible.
151 pub struct OnchainTxHandler<ChanSigner: ChannelKeys> {
152 destination_script: Script,
153 funding_redeemscript: Script,
154 local_commitment: Option<LocalCommitmentTransaction>,
155 prev_local_commitment: Option<LocalCommitmentTransaction>,
156 current_htlc_cache: Option<HTLCTxCache>,
157 prev_htlc_cache: Option<HTLCTxCache>,
159 key_storage: ChanSigner,
161 // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
162 // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
163 // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
164 // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
165 // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
166 // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
167 // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
168 // we need to regenerate new claim request with reduced set of still-claimable outpoints.
169 // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
170 // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
171 // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
172 #[cfg(test)] // Used in functional_test to verify sanitization
173 pub pending_claim_requests: HashMap<Sha256dHash, ClaimTxBumpMaterial>,
175 pending_claim_requests: HashMap<Sha256dHash, ClaimTxBumpMaterial>,
177 // Used to link outpoints claimed in a connected block to a pending claim request.
178 // Key is outpoint than monitor parsing has detected we have keys/scripts to claim
179 // Value is (pending claim request identifier, confirmation_block), identifier
180 // is txid of the initial claiming transaction and is immutable until outpoint is
181 // post-anti-reorg-delay solved, confirmaiton_block is used to erase entry if
182 // block with output gets disconnected.
183 #[cfg(test)] // Used in functional_test to verify sanitization
184 pub claimable_outpoints: HashMap<BitcoinOutPoint, (Sha256dHash, u32)>,
186 claimable_outpoints: HashMap<BitcoinOutPoint, (Sha256dHash, u32)>,
188 onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
190 secp_ctx: Secp256k1<secp256k1::All>,
194 impl<ChanSigner: ChannelKeys + Writeable> OnchainTxHandler<ChanSigner> {
195 pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
196 self.destination_script.write(writer)?;
197 self.funding_redeemscript.write(writer)?;
198 self.local_commitment.write(writer)?;
199 self.prev_local_commitment.write(writer)?;
201 macro_rules! serialize_htlc_cache {
203 $cache.local_keys.write(writer)?;
204 $cache.feerate_per_kw.write(writer)?;
208 if let Some(ref current) = self.current_htlc_cache {
209 writer.write_all(&[1; 1])?;
210 serialize_htlc_cache!(current);
212 writer.write_all(&[0; 1])?;
215 if let Some(ref prev) = self.prev_htlc_cache {
216 writer.write_all(&[1; 1])?;
217 serialize_htlc_cache!(prev);
219 writer.write_all(&[0; 1])?;
222 self.key_storage.write(writer)?;
224 writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
225 for (ref ancestor_claim_txid, claim_tx_data) in self.pending_claim_requests.iter() {
226 ancestor_claim_txid.write(writer)?;
227 claim_tx_data.write(writer)?;
230 writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
231 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
233 claim_and_height.0.write(writer)?;
234 claim_and_height.1.write(writer)?;
237 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
238 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
239 writer.write_all(&byte_utils::be32_to_array(**target))?;
240 writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
241 for ev in events.iter() {
243 OnchainEvent::Claim { ref claim_request } => {
244 writer.write_all(&[0; 1])?;
245 claim_request.write(writer)?;
247 OnchainEvent::ContentiousOutpoint { ref outpoint, ref input_material } => {
248 writer.write_all(&[1; 1])?;
249 outpoint.write(writer)?;
250 input_material.write(writer)?;
259 impl<ChanSigner: ChannelKeys + Readable> ReadableArgs<Arc<Logger>> for OnchainTxHandler<ChanSigner> {
260 fn read<R: ::std::io::Read>(reader: &mut R, logger: Arc<Logger>) -> Result<Self, DecodeError> {
261 let destination_script = Readable::read(reader)?;
262 let funding_redeemscript = Readable::read(reader)?;
263 let local_commitment = Readable::read(reader)?;
264 let prev_local_commitment = Readable::read(reader)?;
266 macro_rules! read_htlc_cache {
269 let local_keys = Readable::read(reader)?;
270 let feerate_per_kw = Readable::read(reader)?;
279 let current_htlc_cache = match <u8 as Readable>::read(reader)? {
282 Some(read_htlc_cache!())
284 _ => return Err(DecodeError::InvalidValue),
287 let prev_htlc_cache = match <u8 as Readable>::read(reader)? {
290 Some(read_htlc_cache!())
292 _ => return Err(DecodeError::InvalidValue),
295 let key_storage = Readable::read(reader)?;
297 let pending_claim_requests_len: u64 = Readable::read(reader)?;
298 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
299 for _ in 0..pending_claim_requests_len {
300 pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
303 let claimable_outpoints_len: u64 = Readable::read(reader)?;
304 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
305 for _ in 0..claimable_outpoints_len {
306 let outpoint = Readable::read(reader)?;
307 let ancestor_claim_txid = Readable::read(reader)?;
308 let height = Readable::read(reader)?;
309 claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
311 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
312 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
313 for _ in 0..waiting_threshold_conf_len {
314 let height_target = Readable::read(reader)?;
315 let events_len: u64 = Readable::read(reader)?;
316 let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
317 for _ in 0..events_len {
318 let ev = match <u8 as Readable>::read(reader)? {
320 let claim_request = Readable::read(reader)?;
321 OnchainEvent::Claim {
326 let outpoint = Readable::read(reader)?;
327 let input_material = Readable::read(reader)?;
328 OnchainEvent::ContentiousOutpoint {
333 _ => return Err(DecodeError::InvalidValue),
337 onchain_events_waiting_threshold_conf.insert(height_target, events);
340 Ok(OnchainTxHandler {
342 funding_redeemscript,
344 prev_local_commitment,
349 pending_claim_requests,
350 onchain_events_waiting_threshold_conf,
351 secp_ctx: Secp256k1::new(),
357 impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
358 pub(super) fn new(destination_script: Script, keys: ChanSigner, funding_redeemscript: Script, logger: Arc<Logger>) -> Self {
360 let key_storage = keys;
364 funding_redeemscript,
365 local_commitment: None,
366 prev_local_commitment: None,
367 current_htlc_cache: None,
368 prev_htlc_cache: None,
370 pending_claim_requests: HashMap::new(),
371 claimable_outpoints: HashMap::new(),
372 onchain_events_waiting_threshold_conf: HashMap::new(),
374 secp_ctx: Secp256k1::new(),
379 pub(super) fn get_witnesses_weight(inputs: &[InputDescriptors]) -> usize {
380 let mut tx_weight = 2; // count segwit flags
382 // We use expected weight (and not actual) as signatures and time lock delays may vary
383 tx_weight += match inp {
384 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
385 &InputDescriptors::RevokedOfferedHTLC => {
386 1 + 1 + 73 + 1 + 33 + 1 + 133
388 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
389 &InputDescriptors::RevokedReceivedHTLC => {
390 1 + 1 + 73 + 1 + 33 + 1 + 139
392 // number_of_witness_elements + sig_length + remotehtlc_sig + preimage_length + preimage + witness_script_length + witness_script
393 &InputDescriptors::OfferedHTLC => {
394 1 + 1 + 73 + 1 + 32 + 1 + 133
396 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
397 &InputDescriptors::ReceivedHTLC => {
398 1 + 1 + 73 + 1 + 1 + 1 + 139
400 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
401 &InputDescriptors::RevokedOutput => {
402 1 + 1 + 73 + 1 + 1 + 1 + 77
409 /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
410 /// 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
411 /// height than once reached we should generate a new bumped "version" of the claim tx to be sure than we safely claim outputs before
412 /// than our counterparty can do it too. If timelock expires soon, height timer is going to be scale down in consequence to increase
413 /// frequency of the bump and so increase our bets of success.
414 fn get_height_timer(current_height: u32, timelock_expiration: u32) -> u32 {
415 if timelock_expiration <= current_height + 3 {
416 return current_height + 1
417 } else if timelock_expiration - current_height <= 15 {
418 return current_height + 3
423 /// 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
424 /// (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.
425 fn generate_claim_tx<F: Deref>(&self, height: u32, cached_claim_datas: &ClaimTxBumpMaterial, fee_estimator: F) -> Option<(Option<u32>, u64, Transaction)>
426 where F::Target: FeeEstimator
428 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
429 let mut inputs = Vec::new();
430 for outp in cached_claim_datas.per_input_material.keys() {
431 log_trace!(self, "Outpoint {}:{}", outp.txid, outp.vout);
433 previous_output: *outp,
434 script_sig: Script::new(),
435 sequence: 0xfffffffd,
439 let mut bumped_tx = Transaction {
444 script_pubkey: self.destination_script.clone(),
449 macro_rules! RBF_bump {
450 ($amount: expr, $old_feerate: expr, $fee_estimator: expr, $predicted_weight: expr) => {
452 let mut used_feerate;
453 // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
454 let new_fee = if $old_feerate < $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) {
455 let mut value = $amount;
456 if subtract_high_prio_fee!(self, $fee_estimator, value, $predicted_weight, used_feerate) {
457 // Overflow check is done in subtract_high_prio_fee
460 log_trace!(self, "Can't new-estimation bump new claiming tx, amount {} is too small", $amount);
463 // ...else just increase the previous feerate by 25% (because that's a nice number)
465 let fee = $old_feerate * $predicted_weight / 750;
467 log_trace!(self, "Can't 25% bump new claiming tx, amount {} is too small", $amount);
473 let previous_fee = $old_feerate * $predicted_weight / 1000;
474 let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * $predicted_weight / 1000;
475 // BIP 125 Opt-in Full Replace-by-Fee Signaling
476 // * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
477 // * 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.
478 let new_fee = if new_fee < previous_fee + min_relay_fee {
479 new_fee + previous_fee + min_relay_fee - new_fee
483 Some((new_fee, new_fee * 1000 / $predicted_weight))
488 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
489 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
490 let new_timer = Some(Self::get_height_timer(height, cached_claim_datas.soonest_timelock));
491 let mut inputs_witnesses_weight = 0;
493 let mut dynamic_fee = true;
494 for per_outp_material in cached_claim_datas.per_input_material.values() {
495 match per_outp_material {
496 &InputMaterial::Revoked { ref witness_script, ref is_htlc, ref amount, .. } => {
497 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!() });
500 &InputMaterial::RemoteHTLC { ref preimage, ref amount, .. } => {
501 inputs_witnesses_weight += Self::get_witnesses_weight(if preimage.is_some() { &[InputDescriptors::OfferedHTLC] } else { &[InputDescriptors::ReceivedHTLC] });
504 &InputMaterial::LocalHTLC { .. } => { return None; }
505 &InputMaterial::Funding { .. } => {
512 let predicted_weight = bumped_tx.get_weight() + inputs_witnesses_weight;
514 // If old feerate is 0, first iteration of this claim, use normal fee calculation
515 if cached_claim_datas.feerate_previous != 0 {
516 if let Some((new_fee, feerate)) = RBF_bump!(amt, cached_claim_datas.feerate_previous, fee_estimator, predicted_weight as u64) {
517 // If new computed fee is superior at the whole claimable amount burn all in fees
519 bumped_tx.output[0].value = 0;
521 bumped_tx.output[0].value = amt - new_fee;
523 new_feerate = feerate;
524 } else { return None; }
526 if subtract_high_prio_fee!(self, fee_estimator, amt, predicted_weight, new_feerate) {
527 bumped_tx.output[0].value = amt;
528 } else { return None; }
530 assert!(new_feerate != 0);
532 for (i, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
533 match per_outp_material {
534 &InputMaterial::Revoked { ref witness_script, ref pubkey, ref key, ref is_htlc, ref amount } => {
535 let sighash_parts = bip143::SighashComponents::new(&bumped_tx);
536 let sighash = hash_to_message!(&sighash_parts.sighash_all(&bumped_tx.input[i], &witness_script, *amount)[..]);
537 let sig = self.secp_ctx.sign(&sighash, &key);
538 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
539 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
541 bumped_tx.input[i].witness.push(pubkey.unwrap().clone().serialize().to_vec());
543 bumped_tx.input[i].witness.push(vec!(1));
545 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
546 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);
548 &InputMaterial::RemoteHTLC { ref witness_script, ref key, ref preimage, ref amount, ref locktime } => {
549 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
550 let sighash_parts = bip143::SighashComponents::new(&bumped_tx);
551 let sighash = hash_to_message!(&sighash_parts.sighash_all(&bumped_tx.input[i], &witness_script, *amount)[..]);
552 let sig = self.secp_ctx.sign(&sighash, &key);
553 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
554 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
555 if let &Some(preimage) = preimage {
556 bumped_tx.input[i].witness.push(preimage.clone().0.to_vec());
558 bumped_tx.input[i].witness.push(vec![]);
560 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
561 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);
566 log_trace!(self, "...with timer {}", new_timer.unwrap());
567 assert!(predicted_weight >= bumped_tx.get_weight());
568 return Some((new_timer, new_feerate, bumped_tx))
570 for (_, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
571 match per_outp_material {
572 &InputMaterial::LocalHTLC { .. } => {
573 //TODO : Given that Local Commitment Transaction and HTLC-Timeout/HTLC-Success are counter-signed by peer, we can't
574 // RBF them. Need a Lightning specs change and package relay modification :
575 // https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2018-November/016518.html
578 &InputMaterial::Funding { ref channel_value } => {
579 if self.local_commitment.is_some() {
580 let mut local_commitment = self.local_commitment.clone().unwrap();
581 self.key_storage.sign_local_commitment(&mut local_commitment, &self.funding_redeemscript, *channel_value, &self.secp_ctx);
582 let signed_tx = local_commitment.with_valid_witness().clone();
583 let mut amt_outputs = 0;
584 for outp in signed_tx.output.iter() {
585 amt_outputs += outp.value;
587 let feerate = (channel_value - amt_outputs) * 1000 / signed_tx.get_weight() as u64;
588 // Timer set to $NEVER given we can't bump tx without anchor outputs
589 log_trace!(self, "Going to broadcast Local Transaction {} claiming funding output {} from {}...", signed_tx.txid(), outp.vout, outp.txid);
590 return Some((None, feerate, signed_tx));
600 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)
601 where B::Target: BroadcasterInterface,
602 F::Target: FeeEstimator
604 log_trace!(self, "Block at height {} connected with {} claim requests", height, claimable_outpoints.len());
605 let mut new_claims = Vec::new();
606 let mut aggregated_claim = HashMap::new();
607 let mut aggregated_soonest = ::std::u32::MAX;
609 // Try to aggregate outputs if their timelock expiration isn't imminent (absolute_timelock
610 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
611 for req in claimable_outpoints {
612 // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
613 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 {
614 log_trace!(self, "Test if outpoint can be aggregated with expiration {} against {}", req.absolute_timelock, height + CLTV_SHARED_CLAIM_BUFFER);
615 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
616 let mut single_input = HashMap::new();
617 single_input.insert(req.outpoint, req.witness_data);
618 new_claims.push((req.absolute_timelock, single_input));
620 aggregated_claim.insert(req.outpoint, req.witness_data);
621 if req.absolute_timelock < aggregated_soonest {
622 aggregated_soonest = req.absolute_timelock;
627 new_claims.push((aggregated_soonest, aggregated_claim));
629 // Generate claim transactions and track them to bump if necessary at
630 // height timer expiration (i.e in how many blocks we're going to take action).
631 for claim in new_claims {
632 let mut claim_material = ClaimTxBumpMaterial { height_timer: None, feerate_previous: 0, soonest_timelock: claim.0, per_input_material: claim.1.clone() };
633 if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator) {
634 claim_material.height_timer = new_timer;
635 claim_material.feerate_previous = new_feerate;
636 let txid = tx.txid();
637 self.pending_claim_requests.insert(txid, claim_material);
638 for k in claim.1.keys() {
639 log_trace!(self, "Registering claiming request for {}:{}", k.txid, k.vout);
640 self.claimable_outpoints.insert(k.clone(), (txid, height));
642 log_trace!(self, "Broadcast onchain {}", log_tx!(tx));
643 broadcaster.broadcast_transaction(&tx);
647 let mut bump_candidates = HashSet::new();
648 for tx in txn_matched {
649 // Scan all input to verify is one of the outpoint spent is of interest for us
650 let mut claimed_outputs_material = Vec::new();
651 for inp in &tx.input {
652 if let Some(first_claim_txid_height) = self.claimable_outpoints.get(&inp.previous_output) {
653 // If outpoint has claim request pending on it...
654 if let Some(claim_material) = self.pending_claim_requests.get_mut(&first_claim_txid_height.0) {
655 //... we need to verify equality between transaction outpoints and claim request
656 // outpoints to know if transaction is the original claim or a bumped one issued
658 let mut set_equality = true;
659 if claim_material.per_input_material.len() != tx.input.len() {
660 set_equality = false;
662 for (claim_inp, tx_inp) in claim_material.per_input_material.keys().zip(tx.input.iter()) {
663 if *claim_inp != tx_inp.previous_output {
664 set_equality = false;
669 macro_rules! clean_claim_request_after_safety_delay {
671 let new_event = OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() };
672 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
673 hash_map::Entry::Occupied(mut entry) => {
674 if !entry.get().contains(&new_event) {
675 entry.get_mut().push(new_event);
678 hash_map::Entry::Vacant(entry) => {
679 entry.insert(vec![new_event]);
685 // If this is our transaction (or our counterparty spent all the outputs
686 // before we could anyway with same inputs order than us), wait for
687 // ANTI_REORG_DELAY and clean the RBF tracking map.
689 clean_claim_request_after_safety_delay!();
690 } else { // If false, generate new claim request with update outpoint set
691 let mut at_least_one_drop = false;
692 for input in tx.input.iter() {
693 if let Some(input_material) = claim_material.per_input_material.remove(&input.previous_output) {
694 claimed_outputs_material.push((input.previous_output, input_material));
695 at_least_one_drop = true;
697 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
698 if claim_material.per_input_material.is_empty() {
699 clean_claim_request_after_safety_delay!();
702 //TODO: recompute soonest_timelock to avoid wasting a bit on fees
703 if at_least_one_drop {
704 bump_candidates.insert(first_claim_txid_height.0.clone());
707 break; //No need to iterate further, either tx is our or their
709 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
713 for (outpoint, input_material) in claimed_outputs_material.drain(..) {
714 let new_event = OnchainEvent::ContentiousOutpoint { outpoint, input_material };
715 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
716 hash_map::Entry::Occupied(mut entry) => {
717 if !entry.get().contains(&new_event) {
718 entry.get_mut().push(new_event);
721 hash_map::Entry::Vacant(entry) => {
722 entry.insert(vec![new_event]);
728 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
729 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
732 OnchainEvent::Claim { claim_request } => {
733 // We may remove a whole set of claim outpoints here, as these one may have
734 // been aggregated in a single tx and claimed so atomically
735 if let Some(bump_material) = self.pending_claim_requests.remove(&claim_request) {
736 for outpoint in bump_material.per_input_material.keys() {
737 self.claimable_outpoints.remove(&outpoint);
741 OnchainEvent::ContentiousOutpoint { outpoint, .. } => {
742 self.claimable_outpoints.remove(&outpoint);
748 // Check if any pending claim request must be rescheduled
749 for (first_claim_txid, ref claim_data) in self.pending_claim_requests.iter() {
750 if let Some(h) = claim_data.height_timer {
752 bump_candidates.insert(*first_claim_txid);
757 // Build, bump and rebroadcast tx accordingly
758 log_trace!(self, "Bumping {} candidates", bump_candidates.len());
759 for first_claim_txid in bump_candidates.iter() {
760 if let Some((new_timer, new_feerate)) = {
761 if let Some(claim_material) = self.pending_claim_requests.get(first_claim_txid) {
762 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator) {
763 log_trace!(self, "Broadcast onchain {}", log_tx!(bump_tx));
764 broadcaster.broadcast_transaction(&bump_tx);
765 Some((new_timer, new_feerate))
767 } else { unreachable!(); }
769 if let Some(claim_material) = self.pending_claim_requests.get_mut(first_claim_txid) {
770 claim_material.height_timer = new_timer;
771 claim_material.feerate_previous = new_feerate;
772 } else { unreachable!(); }
777 pub(super) fn block_disconnected<B: Deref, F: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: F)
778 where B::Target: BroadcasterInterface,
779 F::Target: FeeEstimator
781 let mut bump_candidates = HashMap::new();
782 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
783 //- our claim tx on a commitment tx output
784 //- resurect outpoint back in its claimable set and regenerate tx
787 OnchainEvent::ContentiousOutpoint { outpoint, input_material } => {
788 if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&outpoint) {
789 if let Some(claim_material) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) {
790 claim_material.per_input_material.insert(outpoint, input_material);
791 // Using a HashMap guarantee us than if we have multiple outpoints getting
792 // resurrected only one bump claim tx is going to be broadcast
793 bump_candidates.insert(ancestor_claimable_txid.clone(), claim_material.clone());
801 for (_, claim_material) in bump_candidates.iter_mut() {
802 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator) {
803 claim_material.height_timer = new_timer;
804 claim_material.feerate_previous = new_feerate;
805 broadcaster.broadcast_transaction(&bump_tx);
808 for (ancestor_claim_txid, claim_material) in bump_candidates.drain() {
809 self.pending_claim_requests.insert(ancestor_claim_txid.0, claim_material);
811 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
812 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
813 let mut remove_request = Vec::new();
814 self.claimable_outpoints.retain(|_, ref v|
816 remove_request.push(v.0.clone());
819 for req in remove_request {
820 self.pending_claim_requests.remove(&req);
824 pub(super) fn provide_latest_local_tx(&mut self, tx: LocalCommitmentTransaction, local_keys: chan_utils::TxCreationKeys, feerate_per_kw: u64) -> Result<(), ()> {
825 // To prevent any unsafe state discrepancy between offchain and onchain, once local
826 // commitment transaction has been signed due to an event (either block height for
827 // HTLC-timeout or channel force-closure), don't allow any further update of local
828 // commitment transaction view to avoid delivery of revocation secret to counterparty
829 // for the aformentionned signed transaction.
830 if let Some(ref local_commitment) = self.local_commitment {
831 if local_commitment.has_local_sig() { return Err(()) }
833 self.prev_local_commitment = self.local_commitment.take();
834 self.local_commitment = Some(tx);
835 self.prev_htlc_cache = self.current_htlc_cache.take();
836 self.current_htlc_cache = Some(HTLCTxCache {
843 pub(super) fn get_fully_signed_local_tx(&mut self, channel_value_satoshis: u64) -> Option<Transaction> {
844 if let Some(ref mut local_commitment) = self.local_commitment {
845 self.key_storage.sign_local_commitment(local_commitment, &self.funding_redeemscript, channel_value_satoshis, &self.secp_ctx);
846 return Some(local_commitment.with_valid_witness().clone());
852 pub(super) fn get_fully_signed_copy_local_tx(&mut self, channel_value_satoshis: u64) -> Option<Transaction> {
853 if let Some(ref mut local_commitment) = self.local_commitment {
854 let mut local_commitment = local_commitment.clone();
855 self.key_storage.unsafe_sign_local_commitment(&mut local_commitment, &self.funding_redeemscript, channel_value_satoshis, &self.secp_ctx);
856 return Some(local_commitment.with_valid_witness().clone());