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;
10 use bitcoin::hash_types::Txid;
12 use bitcoin::secp256k1::{Secp256k1, Signature};
13 use bitcoin::secp256k1;
14 use bitcoin::secp256k1::key::PublicKey;
16 use ln::msgs::DecodeError;
17 use ln::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER, InputMaterial, ClaimRequest};
18 use ln::channelmanager::PaymentPreimage;
20 use ln::chan_utils::{TxCreationKeys, LocalCommitmentTransaction, HTLCOutputInCommitment};
21 use chain::chaininterface::{FeeEstimator, BroadcasterInterface, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT};
22 use chain::keysinterface::ChannelKeys;
23 use util::logger::Logger;
24 use util::ser::{Readable, Writer, Writeable};
27 use std::collections::{HashMap, hash_map};
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.
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 remote basepoint to compute any transaction on
52 /// remote outputs, either justice or preimage/timeout transactions.
53 struct RemoteTxCache {
54 remote_delayed_payment_base_key: PublicKey,
55 remote_htlc_base_key: PublicKey,
56 per_htlc: HashMap<Txid, Vec<HTLCOutputInCommitment>>
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 })
104 #[derive(PartialEq, Clone, Copy)]
105 pub(crate) 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 impl Writeable for InputDescriptors {
114 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
116 &InputDescriptors::RevokedOfferedHTLC => {
117 writer.write_all(&[0; 1])?;
119 &InputDescriptors::RevokedReceivedHTLC => {
120 writer.write_all(&[1; 1])?;
122 &InputDescriptors::OfferedHTLC => {
123 writer.write_all(&[2; 1])?;
125 &InputDescriptors::ReceivedHTLC => {
126 writer.write_all(&[3; 1])?;
128 &InputDescriptors::RevokedOutput => {
129 writer.write_all(&[4; 1])?;
136 impl Readable for InputDescriptors {
137 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
138 let input_descriptor = match <u8 as Readable>::read(reader)? {
140 InputDescriptors::RevokedOfferedHTLC
143 InputDescriptors::RevokedReceivedHTLC
146 InputDescriptors::OfferedHTLC
149 InputDescriptors::ReceivedHTLC
152 InputDescriptors::RevokedOutput
154 _ => return Err(DecodeError::InvalidValue),
160 macro_rules! subtract_high_prio_fee {
161 ($logger: ident, $fee_estimator: expr, $value: expr, $predicted_weight: expr, $used_feerate: expr) => {
163 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority);
164 let mut fee = $used_feerate * ($predicted_weight as u64) / 1000;
166 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);
167 fee = $used_feerate * ($predicted_weight as u64) / 1000;
169 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
170 fee = $used_feerate * ($predicted_weight as u64) / 1000;
172 log_error!($logger, "Failed to generate an on-chain punishment tx as even low priority fee ({} sat) was more than the entire claim balance ({} sat)",
176 log_warn!($logger, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
182 log_warn!($logger, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
195 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
196 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
197 match Readable::read(reader)? {
200 let vlen: u64 = Readable::read(reader)?;
201 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<Option<(usize, Signature)>>()));
203 ret.push(match Readable::read(reader)? {
205 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
206 _ => return Err(DecodeError::InvalidValue)
211 _ => Err(DecodeError::InvalidValue),
216 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
217 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
221 (vec.len() as u64).write(writer)?;
222 for opt in vec.iter() {
224 &Some((ref idx, ref sig)) => {
226 (*idx as u64).write(writer)?;
229 &None => 0u8.write(writer)?,
233 &None => 0u8.write(writer)?,
240 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
241 /// do RBF bumping if possible.
242 pub struct OnchainTxHandler<ChanSigner: ChannelKeys> {
243 destination_script: Script,
244 local_commitment: Option<LocalCommitmentTransaction>,
245 // local_htlc_sigs and prev_local_htlc_sigs are in the order as they appear in the commitment
246 // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
247 // the set of HTLCs in the LocalCommitmentTransaction (including those which do not appear in
248 // the commitment transaction).
249 local_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
250 prev_local_commitment: Option<LocalCommitmentTransaction>,
251 prev_local_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
253 remote_tx_cache: RemoteTxCache,
256 key_storage: ChanSigner,
258 // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
259 // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
260 // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
261 // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
262 // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
263 // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
264 // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
265 // we need to regenerate new claim request with reduced set of still-claimable outpoints.
266 // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
267 // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
268 // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
269 #[cfg(test)] // Used in functional_test to verify sanitization
270 pub pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
272 pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
274 // Used to link outpoints claimed in a connected block to a pending claim request.
275 // Key is outpoint than monitor parsing has detected we have keys/scripts to claim
276 // Value is (pending claim request identifier, confirmation_block), identifier
277 // is txid of the initial claiming transaction and is immutable until outpoint is
278 // post-anti-reorg-delay solved, confirmaiton_block is used to erase entry if
279 // block with output gets disconnected.
280 #[cfg(test)] // Used in functional_test to verify sanitization
281 pub claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
283 claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
285 onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
287 secp_ctx: Secp256k1<secp256k1::All>,
290 impl<ChanSigner: ChannelKeys + Writeable> OnchainTxHandler<ChanSigner> {
291 pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
292 self.destination_script.write(writer)?;
293 self.local_commitment.write(writer)?;
294 self.local_htlc_sigs.write(writer)?;
295 self.prev_local_commitment.write(writer)?;
296 self.prev_local_htlc_sigs.write(writer)?;
298 self.local_csv.write(writer)?;
300 self.remote_tx_cache.remote_delayed_payment_base_key.write(writer)?;
301 self.remote_tx_cache.remote_htlc_base_key.write(writer)?;
302 writer.write_all(&byte_utils::be64_to_array(self.remote_tx_cache.per_htlc.len() as u64))?;
303 for (ref txid, ref htlcs) in self.remote_tx_cache.per_htlc.iter() {
304 writer.write_all(&txid[..])?;
305 writer.write_all(&byte_utils::be64_to_array(htlcs.len() as u64))?;
306 for &ref htlc in htlcs.iter() {
310 self.remote_csv.write(writer)?;
312 self.key_storage.write(writer)?;
314 writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
315 for (ref ancestor_claim_txid, claim_tx_data) in self.pending_claim_requests.iter() {
316 ancestor_claim_txid.write(writer)?;
317 claim_tx_data.write(writer)?;
320 writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
321 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
323 claim_and_height.0.write(writer)?;
324 claim_and_height.1.write(writer)?;
327 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
328 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
329 writer.write_all(&byte_utils::be32_to_array(**target))?;
330 writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
331 for ev in events.iter() {
333 OnchainEvent::Claim { ref claim_request } => {
334 writer.write_all(&[0; 1])?;
335 claim_request.write(writer)?;
337 OnchainEvent::ContentiousOutpoint { ref outpoint, ref input_material } => {
338 writer.write_all(&[1; 1])?;
339 outpoint.write(writer)?;
340 input_material.write(writer)?;
349 impl<ChanSigner: ChannelKeys + Readable> Readable for OnchainTxHandler<ChanSigner> {
350 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
351 let destination_script = Readable::read(reader)?;
353 let local_commitment = Readable::read(reader)?;
354 let local_htlc_sigs = Readable::read(reader)?;
355 let prev_local_commitment = Readable::read(reader)?;
356 let prev_local_htlc_sigs = Readable::read(reader)?;
358 let local_csv = Readable::read(reader)?;
360 let remote_tx_cache = {
361 let remote_delayed_payment_base_key = Readable::read(reader)?;
362 let remote_htlc_base_key = Readable::read(reader)?;
363 let per_htlc_len: u64 = Readable::read(reader)?;
364 let mut per_htlc = HashMap::with_capacity(cmp::min(per_htlc_len as usize, MAX_ALLOC_SIZE / 64));
365 for _ in 0..per_htlc_len {
366 let txid: Txid = Readable::read(reader)?;
367 let htlcs_count: u64 = Readable::read(reader)?;
368 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
369 for _ in 0..htlcs_count {
370 let htlc = Readable::read(reader)?;
373 if let Some(_) = per_htlc.insert(txid, htlcs) {
374 return Err(DecodeError::InvalidValue);
378 remote_delayed_payment_base_key,
379 remote_htlc_base_key,
383 let remote_csv = Readable::read(reader)?;
385 let key_storage = Readable::read(reader)?;
387 let pending_claim_requests_len: u64 = Readable::read(reader)?;
388 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
389 for _ in 0..pending_claim_requests_len {
390 pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
393 let claimable_outpoints_len: u64 = Readable::read(reader)?;
394 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
395 for _ in 0..claimable_outpoints_len {
396 let outpoint = Readable::read(reader)?;
397 let ancestor_claim_txid = Readable::read(reader)?;
398 let height = Readable::read(reader)?;
399 claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
401 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
402 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
403 for _ in 0..waiting_threshold_conf_len {
404 let height_target = Readable::read(reader)?;
405 let events_len: u64 = Readable::read(reader)?;
406 let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
407 for _ in 0..events_len {
408 let ev = match <u8 as Readable>::read(reader)? {
410 let claim_request = Readable::read(reader)?;
411 OnchainEvent::Claim {
416 let outpoint = Readable::read(reader)?;
417 let input_material = Readable::read(reader)?;
418 OnchainEvent::ContentiousOutpoint {
423 _ => return Err(DecodeError::InvalidValue),
427 onchain_events_waiting_threshold_conf.insert(height_target, events);
430 Ok(OnchainTxHandler {
434 prev_local_commitment,
435 prev_local_htlc_sigs,
441 pending_claim_requests,
442 onchain_events_waiting_threshold_conf,
443 secp_ctx: Secp256k1::new(),
448 impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
449 pub(super) fn new(destination_script: Script, keys: ChanSigner, local_csv: u16, remote_delayed_payment_base_key: PublicKey, remote_htlc_base_key: PublicKey, remote_csv: u16) -> Self {
451 let key_storage = keys;
453 let remote_tx_cache = RemoteTxCache {
454 remote_delayed_payment_base_key,
455 remote_htlc_base_key,
456 per_htlc: HashMap::new(),
461 local_commitment: None,
462 local_htlc_sigs: None,
463 prev_local_commitment: None,
464 prev_local_htlc_sigs: None,
469 pending_claim_requests: HashMap::new(),
470 claimable_outpoints: HashMap::new(),
471 onchain_events_waiting_threshold_conf: HashMap::new(),
473 secp_ctx: Secp256k1::new(),
477 pub(super) fn get_witnesses_weight(inputs: &[InputDescriptors]) -> usize {
478 let mut tx_weight = 2; // count segwit flags
480 // We use expected weight (and not actual) as signatures and time lock delays may vary
481 tx_weight += match inp {
482 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
483 &InputDescriptors::RevokedOfferedHTLC => {
484 1 + 1 + 73 + 1 + 33 + 1 + 133
486 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
487 &InputDescriptors::RevokedReceivedHTLC => {
488 1 + 1 + 73 + 1 + 33 + 1 + 139
490 // number_of_witness_elements + sig_length + remotehtlc_sig + preimage_length + preimage + witness_script_length + witness_script
491 &InputDescriptors::OfferedHTLC => {
492 1 + 1 + 73 + 1 + 32 + 1 + 133
494 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
495 &InputDescriptors::ReceivedHTLC => {
496 1 + 1 + 73 + 1 + 1 + 1 + 139
498 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
499 &InputDescriptors::RevokedOutput => {
500 1 + 1 + 73 + 1 + 1 + 1 + 77
507 /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
508 /// 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
509 /// height than once reached we should generate a new bumped "version" of the claim tx to be sure than we safely claim outputs before
510 /// than our counterparty can do it too. If timelock expires soon, height timer is going to be scale down in consequence to increase
511 /// frequency of the bump and so increase our bets of success.
512 fn get_height_timer(current_height: u32, timelock_expiration: u32) -> u32 {
513 if timelock_expiration <= current_height + 3 {
514 return current_height + 1
515 } else if timelock_expiration - current_height <= 15 {
516 return current_height + 3
521 /// 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
522 /// (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.
523 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)>
524 where F::Target: FeeEstimator,
527 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
528 let mut inputs = Vec::new();
529 for outp in cached_claim_datas.per_input_material.keys() {
530 log_trace!(logger, "Outpoint {}:{}", outp.txid, outp.vout);
532 previous_output: *outp,
533 script_sig: Script::new(),
534 sequence: 0xfffffffd,
538 let mut bumped_tx = Transaction {
543 script_pubkey: self.destination_script.clone(),
548 macro_rules! RBF_bump {
549 ($amount: expr, $old_feerate: expr, $fee_estimator: expr, $predicted_weight: expr) => {
551 let mut used_feerate;
552 // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
553 let new_fee = if $old_feerate < $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) {
554 let mut value = $amount;
555 if subtract_high_prio_fee!(logger, $fee_estimator, value, $predicted_weight, used_feerate) {
556 // Overflow check is done in subtract_high_prio_fee
559 log_trace!(logger, "Can't new-estimation bump new claiming tx, amount {} is too small", $amount);
562 // ...else just increase the previous feerate by 25% (because that's a nice number)
564 let fee = $old_feerate * $predicted_weight / 750;
566 log_trace!(logger, "Can't 25% bump new claiming tx, amount {} is too small", $amount);
572 let previous_fee = $old_feerate * $predicted_weight / 1000;
573 let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * $predicted_weight / 1000;
574 // BIP 125 Opt-in Full Replace-by-Fee Signaling
575 // * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
576 // * 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.
577 let new_fee = if new_fee < previous_fee + min_relay_fee {
578 new_fee + previous_fee + min_relay_fee - new_fee
582 Some((new_fee, new_fee * 1000 / $predicted_weight))
587 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
588 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
589 let new_timer = Some(Self::get_height_timer(height, cached_claim_datas.soonest_timelock));
590 let mut inputs_witnesses_weight = 0;
592 let mut dynamic_fee = true;
593 for per_outp_material in cached_claim_datas.per_input_material.values() {
594 match per_outp_material {
595 &InputMaterial::Revoked { ref input_descriptor, ref amount, .. } => {
596 inputs_witnesses_weight += Self::get_witnesses_weight(&[*input_descriptor]);
599 &InputMaterial::RemoteHTLC { ref preimage, ref amount, .. } => {
600 inputs_witnesses_weight += Self::get_witnesses_weight(if preimage.is_some() { &[InputDescriptors::OfferedHTLC] } else { &[InputDescriptors::ReceivedHTLC] });
603 &InputMaterial::LocalHTLC { .. } => {
606 &InputMaterial::Funding { .. } => {
612 let predicted_weight = bumped_tx.get_weight() + inputs_witnesses_weight;
614 // If old feerate is 0, first iteration of this claim, use normal fee calculation
615 if cached_claim_datas.feerate_previous != 0 {
616 if let Some((new_fee, feerate)) = RBF_bump!(amt, cached_claim_datas.feerate_previous, fee_estimator, predicted_weight as u64) {
617 // If new computed fee is superior at the whole claimable amount burn all in fees
619 bumped_tx.output[0].value = 0;
621 bumped_tx.output[0].value = amt - new_fee;
623 new_feerate = feerate;
624 } else { return None; }
626 if subtract_high_prio_fee!(logger, fee_estimator, amt, predicted_weight, new_feerate) {
627 bumped_tx.output[0].value = amt;
628 } else { return None; }
630 assert!(new_feerate != 0);
632 for (i, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
633 match per_outp_material {
634 &InputMaterial::Revoked { ref per_commitment_point, ref per_commitment_key, ref input_descriptor, ref amount } => {
635 if let Ok(chan_keys) = TxCreationKeys::new(&self.secp_ctx, &per_commitment_point, &self.remote_tx_cache.remote_delayed_payment_base_key, &self.remote_tx_cache.remote_htlc_base_key, &self.key_storage.pubkeys().revocation_basepoint, &self.key_storage.pubkeys().htlc_basepoint) {
637 let mut this_htlc = None;
638 if *input_descriptor != InputDescriptors::RevokedOutput {
639 if let Some(htlcs) = self.remote_tx_cache.per_htlc.get(&outp.txid) {
641 if htlc.transaction_output_index.unwrap() == outp.vout {
642 this_htlc = Some(htlc);
648 let witness_script = if *input_descriptor != InputDescriptors::RevokedOutput && this_htlc.is_some() {
649 chan_utils::get_htlc_redeemscript_with_explicit_keys(&this_htlc.unwrap(), &chan_keys.a_htlc_key, &chan_keys.b_htlc_key, &chan_keys.revocation_key)
650 } else if *input_descriptor != InputDescriptors::RevokedOutput {
653 chan_utils::get_revokeable_redeemscript(&chan_keys.revocation_key, self.remote_csv, &chan_keys.a_delayed_payment_key)
656 let is_htlc = *input_descriptor != InputDescriptors::RevokedOutput;
657 if let Ok(sig) = self.key_storage.sign_justice_transaction(&bumped_tx, i, &witness_script, *amount, &per_commitment_key, &chan_keys.revocation_key, is_htlc, &self.secp_ctx) {
658 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
659 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
661 bumped_tx.input[i].witness.push(chan_keys.revocation_key.clone().serialize().to_vec());
663 bumped_tx.input[i].witness.push(vec!(1));
665 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
666 } else { return None; }
669 log_trace!(logger, "Going to broadcast Penalty Transaction {} claiming revoked {} output {} from {} with new feerate {}...", bumped_tx.txid(), if *input_descriptor == InputDescriptors::RevokedOutput { "to_local" } else if *input_descriptor == InputDescriptors::RevokedOfferedHTLC { "offered" } else if *input_descriptor == InputDescriptors::RevokedReceivedHTLC { "received" } else { "" }, outp.vout, outp.txid, new_feerate);
672 &InputMaterial::RemoteHTLC { ref per_commitment_point, ref preimage, ref amount, ref locktime } => {
673 if let Ok(chan_keys) = TxCreationKeys::new(&self.secp_ctx, &per_commitment_point, &self.remote_tx_cache.remote_delayed_payment_base_key, &self.remote_tx_cache.remote_htlc_base_key, &self.key_storage.pubkeys().revocation_basepoint, &self.key_storage.pubkeys().htlc_basepoint) {
674 let mut this_htlc = None;
675 if let Some(htlcs) = self.remote_tx_cache.per_htlc.get(&outp.txid) {
677 if htlc.transaction_output_index.unwrap() == outp.vout {
678 this_htlc = Some(htlc);
682 if this_htlc.is_none() { return None; }
683 let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&this_htlc.unwrap(), &chan_keys.a_htlc_key, &chan_keys.b_htlc_key, &chan_keys.revocation_key);
685 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
686 if let Ok(sig) = self.key_storage.sign_remote_htlc_transaction(&bumped_tx, i, &witness_script, *amount, &per_commitment_point, preimage, &self.secp_ctx) {
687 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
688 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
689 if let &Some(preimage) = preimage {
690 bumped_tx.input[i].witness.push(preimage.0.to_vec());
692 // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
693 bumped_tx.input[i].witness.push(vec![]);
695 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
697 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);
703 log_trace!(logger, "...with timer {}", new_timer.unwrap());
704 assert!(predicted_weight >= bumped_tx.get_weight());
705 return Some((new_timer, new_feerate, bumped_tx))
707 for (_, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
708 match per_outp_material {
709 &InputMaterial::LocalHTLC { ref preimage, ref amount } => {
710 let htlc_tx = self.get_fully_signed_htlc_tx(outp, preimage);
711 if let Some(htlc_tx) = htlc_tx {
712 let feerate = (amount - htlc_tx.output[0].value) * 1000 / htlc_tx.get_weight() as u64;
713 // Timer set to $NEVER given we can't bump tx without anchor outputs
714 log_trace!(logger, "Going to broadcast Local HTLC-{} claiming HTLC output {} from {}...", if preimage.is_some() { "Success" } else { "Timeout" }, outp.vout, outp.txid);
715 return Some((None, feerate, htlc_tx));
719 &InputMaterial::Funding { ref funding_redeemscript } => {
720 let signed_tx = self.get_fully_signed_local_tx(funding_redeemscript).unwrap();
721 // Timer set to $NEVER given we can't bump tx without anchor outputs
722 log_trace!(logger, "Going to broadcast Local Transaction {} claiming funding output {} from {}...", signed_tx.txid(), outp.vout, outp.txid);
723 return Some((None, self.local_commitment.as_ref().unwrap().feerate_per_kw, signed_tx));
732 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)
733 where B::Target: BroadcasterInterface,
734 F::Target: FeeEstimator,
737 log_trace!(logger, "Block at height {} connected with {} claim requests", height, claimable_outpoints.len());
738 let mut new_claims = Vec::new();
739 let mut aggregated_claim = HashMap::new();
740 let mut aggregated_soonest = ::std::u32::MAX;
742 // Try to aggregate outputs if their timelock expiration isn't imminent (absolute_timelock
743 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
744 for req in claimable_outpoints {
745 // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
746 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 {
747 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.absolute_timelock, height + CLTV_SHARED_CLAIM_BUFFER);
748 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
749 let mut single_input = HashMap::new();
750 single_input.insert(req.outpoint, req.witness_data);
751 new_claims.push((req.absolute_timelock, single_input));
753 aggregated_claim.insert(req.outpoint, req.witness_data);
754 if req.absolute_timelock < aggregated_soonest {
755 aggregated_soonest = req.absolute_timelock;
760 new_claims.push((aggregated_soonest, aggregated_claim));
762 // Generate claim transactions and track them to bump if necessary at
763 // height timer expiration (i.e in how many blocks we're going to take action).
764 for (soonest_timelock, claim) in new_claims.drain(..) {
765 let mut claim_material = ClaimTxBumpMaterial { height_timer: None, feerate_previous: 0, soonest_timelock, per_input_material: claim };
766 if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
767 claim_material.height_timer = new_timer;
768 claim_material.feerate_previous = new_feerate;
769 let txid = tx.txid();
770 for k in claim_material.per_input_material.keys() {
771 log_trace!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
772 self.claimable_outpoints.insert(k.clone(), (txid, height));
774 self.pending_claim_requests.insert(txid, claim_material);
775 log_trace!(logger, "Broadcast onchain {}", log_tx!(tx));
776 broadcaster.broadcast_transaction(&tx);
780 let mut bump_candidates = HashMap::new();
781 for tx in txn_matched {
782 // Scan all input to verify is one of the outpoint spent is of interest for us
783 let mut claimed_outputs_material = Vec::new();
784 for inp in &tx.input {
785 if let Some(first_claim_txid_height) = self.claimable_outpoints.get(&inp.previous_output) {
786 // If outpoint has claim request pending on it...
787 if let Some(claim_material) = self.pending_claim_requests.get_mut(&first_claim_txid_height.0) {
788 //... we need to verify equality between transaction outpoints and claim request
789 // outpoints to know if transaction is the original claim or a bumped one issued
791 let mut set_equality = true;
792 if claim_material.per_input_material.len() != tx.input.len() {
793 set_equality = false;
795 for (claim_inp, tx_inp) in claim_material.per_input_material.keys().zip(tx.input.iter()) {
796 if *claim_inp != tx_inp.previous_output {
797 set_equality = false;
802 macro_rules! clean_claim_request_after_safety_delay {
804 let new_event = OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() };
805 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
806 hash_map::Entry::Occupied(mut entry) => {
807 if !entry.get().contains(&new_event) {
808 entry.get_mut().push(new_event);
811 hash_map::Entry::Vacant(entry) => {
812 entry.insert(vec![new_event]);
818 // If this is our transaction (or our counterparty spent all the outputs
819 // before we could anyway with same inputs order than us), wait for
820 // ANTI_REORG_DELAY and clean the RBF tracking map.
822 clean_claim_request_after_safety_delay!();
823 } else { // If false, generate new claim request with update outpoint set
824 let mut at_least_one_drop = false;
825 for input in tx.input.iter() {
826 if let Some(input_material) = claim_material.per_input_material.remove(&input.previous_output) {
827 claimed_outputs_material.push((input.previous_output, input_material));
828 at_least_one_drop = true;
830 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
831 if claim_material.per_input_material.is_empty() {
832 clean_claim_request_after_safety_delay!();
835 //TODO: recompute soonest_timelock to avoid wasting a bit on fees
836 if at_least_one_drop {
837 bump_candidates.insert(first_claim_txid_height.0.clone(), claim_material.clone());
840 break; //No need to iterate further, either tx is our or their
842 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
846 for (outpoint, input_material) in claimed_outputs_material.drain(..) {
847 let new_event = OnchainEvent::ContentiousOutpoint { outpoint, input_material };
848 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
849 hash_map::Entry::Occupied(mut entry) => {
850 if !entry.get().contains(&new_event) {
851 entry.get_mut().push(new_event);
854 hash_map::Entry::Vacant(entry) => {
855 entry.insert(vec![new_event]);
861 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
862 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
865 OnchainEvent::Claim { claim_request } => {
866 // We may remove a whole set of claim outpoints here, as these one may have
867 // been aggregated in a single tx and claimed so atomically
868 if let Some(bump_material) = self.pending_claim_requests.remove(&claim_request) {
869 for outpoint in bump_material.per_input_material.keys() {
870 self.claimable_outpoints.remove(&outpoint);
874 OnchainEvent::ContentiousOutpoint { outpoint, .. } => {
875 self.claimable_outpoints.remove(&outpoint);
881 // Check if any pending claim request must be rescheduled
882 for (first_claim_txid, ref claim_data) in self.pending_claim_requests.iter() {
883 if let Some(h) = claim_data.height_timer {
885 bump_candidates.insert(*first_claim_txid, (*claim_data).clone());
890 // Build, bump and rebroadcast tx accordingly
891 log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
892 for (first_claim_txid, claim_material) in bump_candidates.iter() {
893 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
894 log_trace!(logger, "Broadcast onchain {}", log_tx!(bump_tx));
895 broadcaster.broadcast_transaction(&bump_tx);
896 if let Some(claim_material) = self.pending_claim_requests.get_mut(first_claim_txid) {
897 claim_material.height_timer = new_timer;
898 claim_material.feerate_previous = new_feerate;
904 pub(super) fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: F, logger: L)
905 where B::Target: BroadcasterInterface,
906 F::Target: FeeEstimator,
909 let mut bump_candidates = HashMap::new();
910 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
911 //- our claim tx on a commitment tx output
912 //- resurect outpoint back in its claimable set and regenerate tx
915 OnchainEvent::ContentiousOutpoint { outpoint, input_material } => {
916 if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&outpoint) {
917 if let Some(claim_material) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) {
918 claim_material.per_input_material.insert(outpoint, input_material);
919 // Using a HashMap guarantee us than if we have multiple outpoints getting
920 // resurrected only one bump claim tx is going to be broadcast
921 bump_candidates.insert(ancestor_claimable_txid.clone(), claim_material.clone());
929 for (_, claim_material) in bump_candidates.iter_mut() {
930 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
931 claim_material.height_timer = new_timer;
932 claim_material.feerate_previous = new_feerate;
933 broadcaster.broadcast_transaction(&bump_tx);
936 for (ancestor_claim_txid, claim_material) in bump_candidates.drain() {
937 self.pending_claim_requests.insert(ancestor_claim_txid.0, claim_material);
939 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
940 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
941 let mut remove_request = Vec::new();
942 self.claimable_outpoints.retain(|_, ref v|
944 remove_request.push(v.0.clone());
947 for req in remove_request {
948 self.pending_claim_requests.remove(&req);
952 pub(super) fn provide_latest_local_tx(&mut self, tx: LocalCommitmentTransaction) -> Result<(), ()> {
953 // To prevent any unsafe state discrepancy between offchain and onchain, once local
954 // commitment transaction has been signed due to an event (either block height for
955 // HTLC-timeout or channel force-closure), don't allow any further update of local
956 // commitment transaction view to avoid delivery of revocation secret to counterparty
957 // for the aformentionned signed transaction.
958 if self.local_htlc_sigs.is_some() || self.prev_local_htlc_sigs.is_some() {
961 self.prev_local_commitment = self.local_commitment.take();
962 self.local_commitment = Some(tx);
966 fn sign_latest_local_htlcs(&mut self) {
967 if let Some(ref local_commitment) = self.local_commitment {
968 if let Ok(sigs) = self.key_storage.sign_local_commitment_htlc_transactions(local_commitment, self.local_csv, &self.secp_ctx) {
969 self.local_htlc_sigs = Some(Vec::new());
970 let ret = self.local_htlc_sigs.as_mut().unwrap();
971 for (htlc_idx, (local_sig, &(ref htlc, _))) in sigs.iter().zip(local_commitment.per_htlc.iter()).enumerate() {
972 if let Some(tx_idx) = htlc.transaction_output_index {
973 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
974 ret[tx_idx as usize] = Some((htlc_idx, local_sig.expect("Did not receive a signature for a non-dust HTLC")));
976 assert!(local_sig.is_none(), "Received a signature for a dust HTLC");
982 fn sign_prev_local_htlcs(&mut self) {
983 if let Some(ref local_commitment) = self.prev_local_commitment {
984 if let Ok(sigs) = self.key_storage.sign_local_commitment_htlc_transactions(local_commitment, self.local_csv, &self.secp_ctx) {
985 self.prev_local_htlc_sigs = Some(Vec::new());
986 let ret = self.prev_local_htlc_sigs.as_mut().unwrap();
987 for (htlc_idx, (local_sig, &(ref htlc, _))) in sigs.iter().zip(local_commitment.per_htlc.iter()).enumerate() {
988 if let Some(tx_idx) = htlc.transaction_output_index {
989 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
990 ret[tx_idx as usize] = Some((htlc_idx, local_sig.expect("Did not receive a signature for a non-dust HTLC")));
992 assert!(local_sig.is_none(), "Received a signature for a dust HTLC");
999 //TODO: getting lastest local transactions should be infaillible and result in us "force-closing the channel", but we may
1000 // have empty local commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
1001 // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
1002 // to monitor before.
1003 pub(super) fn get_fully_signed_local_tx(&mut self, funding_redeemscript: &Script) -> Option<Transaction> {
1004 if let Some(ref mut local_commitment) = self.local_commitment {
1005 match self.key_storage.sign_local_commitment(local_commitment, &self.secp_ctx) {
1006 Ok(sig) => Some(local_commitment.add_local_sig(funding_redeemscript, sig)),
1007 Err(_) => return None,
1014 pub(super) fn provide_latest_remote_tx(&mut self, commitment_txid: Txid, htlcs: Vec<HTLCOutputInCommitment>) {
1015 self.remote_tx_cache.per_htlc.insert(commitment_txid, htlcs);
1019 pub(super) fn get_fully_signed_copy_local_tx(&mut self, funding_redeemscript: &Script) -> Option<Transaction> {
1020 if let Some(ref mut local_commitment) = self.local_commitment {
1021 let local_commitment = local_commitment.clone();
1022 match self.key_storage.sign_local_commitment(&local_commitment, &self.secp_ctx) {
1023 Ok(sig) => Some(local_commitment.add_local_sig(funding_redeemscript, sig)),
1024 Err(_) => return None,
1031 pub(super) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
1032 let mut htlc_tx = None;
1033 if self.local_commitment.is_some() {
1034 let commitment_txid = self.local_commitment.as_ref().unwrap().txid();
1035 if commitment_txid == outp.txid {
1036 self.sign_latest_local_htlcs();
1037 if let &Some(ref htlc_sigs) = &self.local_htlc_sigs {
1038 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
1039 htlc_tx = Some(self.local_commitment.as_ref().unwrap()
1040 .get_signed_htlc_tx(*htlc_idx, htlc_sig, preimage, self.local_csv));
1044 if self.prev_local_commitment.is_some() {
1045 let commitment_txid = self.prev_local_commitment.as_ref().unwrap().txid();
1046 if commitment_txid == outp.txid {
1047 self.sign_prev_local_htlcs();
1048 if let &Some(ref htlc_sigs) = &self.prev_local_htlc_sigs {
1049 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
1050 htlc_tx = Some(self.prev_local_commitment.as_ref().unwrap()
1051 .get_signed_htlc_tx(*htlc_idx, htlc_sig, preimage, self.local_csv));
1059 pub(super) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
1060 let latest_had_sigs = self.local_htlc_sigs.is_some();
1061 let prev_had_sigs = self.prev_local_htlc_sigs.is_some();
1062 let ret = self.get_fully_signed_htlc_tx(outp, preimage);
1063 if !latest_had_sigs {
1064 self.local_htlc_sigs = None;
1067 self.prev_local_htlc_sigs = None;