1 //! The logic to build claims and bump in-flight transactions until confirmations.
3 //! OnchainTxHandler objetcs are fully-part of ChannelMonitor and encapsulates all
4 //! building, tracking, bumping and notifications functions.
6 use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
7 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
8 use bitcoin::blockdata::script::Script;
9 use bitcoin::util::bip143;
11 use bitcoin::hash_types::Txid;
13 use bitcoin::secp256k1::{Secp256k1, Signature};
14 use bitcoin::secp256k1;
15 use bitcoin::secp256k1::key::PublicKey;
17 use ln::msgs::DecodeError;
18 use ln::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER, InputMaterial, ClaimRequest};
19 use ln::channelmanager::PaymentPreimage;
21 use ln::chan_utils::{TxCreationKeys, LocalCommitmentTransaction, HTLCOutputInCommitment};
22 use chain::chaininterface::{FeeEstimator, BroadcasterInterface, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT};
23 use chain::keysinterface::ChannelKeys;
24 use util::logger::Logger;
25 use util::ser::{Readable, Writer, Writeable};
28 use std::collections::{HashMap, hash_map};
32 const MAX_ALLOC_SIZE: usize = 64*1024;
34 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
35 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
36 #[derive(Clone, PartialEq)]
38 /// Outpoint under claim process by our own tx, once this one get enough confirmations, we remove it from
39 /// bump-txn candidate buffer.
43 /// Claim tx aggregate multiple claimable outpoints. One of the outpoint may be claimed by a remote party tx.
44 /// In this case, we need to drop the outpoint and regenerate a new claim tx. By safety, we keep tracking
45 /// the outpoint to be sure to resurect it back to the claim tx if reorgs happen.
47 outpoint: BitcoinOutPoint,
48 input_material: InputMaterial,
52 /// Cache remote basepoint to compute any transaction on
53 /// remote outputs, either justice or preimage/timeout transactions.
54 struct RemoteTxCache {
55 remote_delayed_payment_base_key: PublicKey,
56 remote_htlc_base_key: PublicKey,
57 per_htlc: HashMap<Txid, Vec<HTLCOutputInCommitment>>
60 /// Higher-level cache structure needed to re-generate bumped claim txn if needed
61 #[derive(Clone, PartialEq)]
62 pub struct ClaimTxBumpMaterial {
63 // At every block tick, used to check if pending claiming tx is taking too
64 // much time for confirmation and we need to bump it.
65 height_timer: Option<u32>,
66 // Tracked in case of reorg to wipe out now-superflous bump material
67 feerate_previous: u64,
68 // Soonest timelocks among set of outpoints claimed, used to compute
69 // a priority of not feerate
70 soonest_timelock: u32,
71 // Cache of script, pubkey, sig or key to solve claimable outputs scriptpubkey.
72 per_input_material: HashMap<BitcoinOutPoint, InputMaterial>,
75 impl Writeable for ClaimTxBumpMaterial {
76 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
77 self.height_timer.write(writer)?;
78 writer.write_all(&byte_utils::be64_to_array(self.feerate_previous))?;
79 writer.write_all(&byte_utils::be32_to_array(self.soonest_timelock))?;
80 writer.write_all(&byte_utils::be64_to_array(self.per_input_material.len() as u64))?;
81 for (outp, tx_material) in self.per_input_material.iter() {
83 tx_material.write(writer)?;
89 impl Readable for ClaimTxBumpMaterial {
90 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
91 let height_timer = Readable::read(reader)?;
92 let feerate_previous = Readable::read(reader)?;
93 let soonest_timelock = Readable::read(reader)?;
94 let per_input_material_len: u64 = Readable::read(reader)?;
95 let mut per_input_material = HashMap::with_capacity(cmp::min(per_input_material_len as usize, MAX_ALLOC_SIZE / 128));
96 for _ in 0 ..per_input_material_len {
97 let outpoint = Readable::read(reader)?;
98 let input_material = Readable::read(reader)?;
99 per_input_material.insert(outpoint, input_material);
101 Ok(Self { height_timer, feerate_previous, soonest_timelock, per_input_material })
105 #[derive(PartialEq, Clone, Copy)]
106 pub(crate) enum InputDescriptors {
111 RevokedOutput, // either a revoked to_local output on commitment tx, a revoked HTLC-Timeout output or a revoked HTLC-Success output
114 impl Writeable for InputDescriptors {
115 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
117 &InputDescriptors::RevokedOfferedHTLC => {
118 writer.write_all(&[0; 1])?;
120 &InputDescriptors::RevokedReceivedHTLC => {
121 writer.write_all(&[1; 1])?;
123 &InputDescriptors::OfferedHTLC => {
124 writer.write_all(&[2; 1])?;
126 &InputDescriptors::ReceivedHTLC => {
127 writer.write_all(&[3; 1])?;
129 &InputDescriptors::RevokedOutput => {
130 writer.write_all(&[4; 1])?;
137 impl Readable for InputDescriptors {
138 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
139 let input_descriptor = match <u8 as Readable>::read(reader)? {
141 InputDescriptors::RevokedOfferedHTLC
144 InputDescriptors::RevokedReceivedHTLC
147 InputDescriptors::OfferedHTLC
150 InputDescriptors::ReceivedHTLC
153 InputDescriptors::RevokedOutput
155 _ => return Err(DecodeError::InvalidValue),
161 macro_rules! subtract_high_prio_fee {
162 ($logger: ident, $fee_estimator: expr, $value: expr, $predicted_weight: expr, $used_feerate: expr) => {
164 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority);
165 let mut fee = $used_feerate * ($predicted_weight as u64) / 1000;
167 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);
168 fee = $used_feerate * ($predicted_weight as u64) / 1000;
170 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
171 fee = $used_feerate * ($predicted_weight as u64) / 1000;
173 log_error!($logger, "Failed to generate an on-chain punishment tx as even low priority fee ({} sat) was more than the entire claim balance ({} sat)",
177 log_warn!($logger, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
183 log_warn!($logger, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
196 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
197 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
198 match Readable::read(reader)? {
201 let vlen: u64 = Readable::read(reader)?;
202 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<Option<(usize, Signature)>>()));
204 ret.push(match Readable::read(reader)? {
206 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
207 _ => return Err(DecodeError::InvalidValue)
212 _ => Err(DecodeError::InvalidValue),
217 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
218 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
222 (vec.len() as u64).write(writer)?;
223 for opt in vec.iter() {
225 &Some((ref idx, ref sig)) => {
227 (*idx as u64).write(writer)?;
230 &None => 0u8.write(writer)?,
234 &None => 0u8.write(writer)?,
241 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
242 /// do RBF bumping if possible.
243 pub struct OnchainTxHandler<ChanSigner: ChannelKeys> {
244 destination_script: Script,
245 local_commitment: Option<LocalCommitmentTransaction>,
246 // local_htlc_sigs and prev_local_htlc_sigs are in the order as they appear in the commitment
247 // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
248 // the set of HTLCs in the LocalCommitmentTransaction (including those which do not appear in
249 // the commitment transaction).
250 local_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
251 prev_local_commitment: Option<LocalCommitmentTransaction>,
252 prev_local_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
254 remote_tx_cache: RemoteTxCache,
257 key_storage: ChanSigner,
259 // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
260 // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
261 // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
262 // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
263 // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
264 // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
265 // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
266 // we need to regenerate new claim request with reduced set of still-claimable outpoints.
267 // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
268 // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
269 // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
270 #[cfg(test)] // Used in functional_test to verify sanitization
271 pub pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
273 pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
275 // Used to link outpoints claimed in a connected block to a pending claim request.
276 // Key is outpoint than monitor parsing has detected we have keys/scripts to claim
277 // Value is (pending claim request identifier, confirmation_block), identifier
278 // is txid of the initial claiming transaction and is immutable until outpoint is
279 // post-anti-reorg-delay solved, confirmaiton_block is used to erase entry if
280 // block with output gets disconnected.
281 #[cfg(test)] // Used in functional_test to verify sanitization
282 pub claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
284 claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
286 onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
288 secp_ctx: Secp256k1<secp256k1::All>,
291 impl<ChanSigner: ChannelKeys + Writeable> OnchainTxHandler<ChanSigner> {
292 pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
293 self.destination_script.write(writer)?;
294 self.local_commitment.write(writer)?;
295 self.local_htlc_sigs.write(writer)?;
296 self.prev_local_commitment.write(writer)?;
297 self.prev_local_htlc_sigs.write(writer)?;
299 self.local_csv.write(writer)?;
301 self.remote_tx_cache.remote_delayed_payment_base_key.write(writer)?;
302 self.remote_tx_cache.remote_htlc_base_key.write(writer)?;
303 writer.write_all(&byte_utils::be64_to_array(self.remote_tx_cache.per_htlc.len() as u64))?;
304 for (ref txid, ref htlcs) in self.remote_tx_cache.per_htlc.iter() {
305 writer.write_all(&txid[..])?;
306 writer.write_all(&byte_utils::be64_to_array(htlcs.len() as u64))?;
307 for &ref htlc in htlcs.iter() {
311 self.remote_csv.write(writer)?;
313 self.key_storage.write(writer)?;
315 writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
316 for (ref ancestor_claim_txid, claim_tx_data) in self.pending_claim_requests.iter() {
317 ancestor_claim_txid.write(writer)?;
318 claim_tx_data.write(writer)?;
321 writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
322 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
324 claim_and_height.0.write(writer)?;
325 claim_and_height.1.write(writer)?;
328 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
329 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
330 writer.write_all(&byte_utils::be32_to_array(**target))?;
331 writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
332 for ev in events.iter() {
334 OnchainEvent::Claim { ref claim_request } => {
335 writer.write_all(&[0; 1])?;
336 claim_request.write(writer)?;
338 OnchainEvent::ContentiousOutpoint { ref outpoint, ref input_material } => {
339 writer.write_all(&[1; 1])?;
340 outpoint.write(writer)?;
341 input_material.write(writer)?;
350 impl<ChanSigner: ChannelKeys + Readable> Readable for OnchainTxHandler<ChanSigner> {
351 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
352 let destination_script = Readable::read(reader)?;
354 let local_commitment = Readable::read(reader)?;
355 let local_htlc_sigs = Readable::read(reader)?;
356 let prev_local_commitment = Readable::read(reader)?;
357 let prev_local_htlc_sigs = Readable::read(reader)?;
359 let local_csv = Readable::read(reader)?;
361 let remote_tx_cache = {
362 let remote_delayed_payment_base_key = Readable::read(reader)?;
363 let remote_htlc_base_key = Readable::read(reader)?;
364 let per_htlc_len: u64 = Readable::read(reader)?;
365 let mut per_htlc = HashMap::with_capacity(cmp::min(per_htlc_len as usize, MAX_ALLOC_SIZE / 64));
366 for _ in 0..per_htlc_len {
367 let txid: Txid = Readable::read(reader)?;
368 let htlcs_count: u64 = Readable::read(reader)?;
369 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
370 for _ in 0..htlcs_count {
371 let htlc = Readable::read(reader)?;
374 if let Some(_) = per_htlc.insert(txid, htlcs) {
375 return Err(DecodeError::InvalidValue);
379 remote_delayed_payment_base_key,
380 remote_htlc_base_key,
384 let remote_csv = Readable::read(reader)?;
386 let key_storage = Readable::read(reader)?;
388 let pending_claim_requests_len: u64 = Readable::read(reader)?;
389 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
390 for _ in 0..pending_claim_requests_len {
391 pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
394 let claimable_outpoints_len: u64 = Readable::read(reader)?;
395 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
396 for _ in 0..claimable_outpoints_len {
397 let outpoint = Readable::read(reader)?;
398 let ancestor_claim_txid = Readable::read(reader)?;
399 let height = Readable::read(reader)?;
400 claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
402 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
403 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
404 for _ in 0..waiting_threshold_conf_len {
405 let height_target = Readable::read(reader)?;
406 let events_len: u64 = Readable::read(reader)?;
407 let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
408 for _ in 0..events_len {
409 let ev = match <u8 as Readable>::read(reader)? {
411 let claim_request = Readable::read(reader)?;
412 OnchainEvent::Claim {
417 let outpoint = Readable::read(reader)?;
418 let input_material = Readable::read(reader)?;
419 OnchainEvent::ContentiousOutpoint {
424 _ => return Err(DecodeError::InvalidValue),
428 onchain_events_waiting_threshold_conf.insert(height_target, events);
431 Ok(OnchainTxHandler {
435 prev_local_commitment,
436 prev_local_htlc_sigs,
442 pending_claim_requests,
443 onchain_events_waiting_threshold_conf,
444 secp_ctx: Secp256k1::new(),
449 impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
450 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 {
452 let key_storage = keys;
454 let remote_tx_cache = RemoteTxCache {
455 remote_delayed_payment_base_key,
456 remote_htlc_base_key,
457 per_htlc: HashMap::new(),
462 local_commitment: None,
463 local_htlc_sigs: None,
464 prev_local_commitment: None,
465 prev_local_htlc_sigs: None,
470 pending_claim_requests: HashMap::new(),
471 claimable_outpoints: HashMap::new(),
472 onchain_events_waiting_threshold_conf: HashMap::new(),
474 secp_ctx: Secp256k1::new(),
478 pub(super) fn get_witnesses_weight(inputs: &[InputDescriptors]) -> usize {
479 let mut tx_weight = 2; // count segwit flags
481 // We use expected weight (and not actual) as signatures and time lock delays may vary
482 tx_weight += match inp {
483 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
484 &InputDescriptors::RevokedOfferedHTLC => {
485 1 + 1 + 73 + 1 + 33 + 1 + 133
487 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
488 &InputDescriptors::RevokedReceivedHTLC => {
489 1 + 1 + 73 + 1 + 33 + 1 + 139
491 // number_of_witness_elements + sig_length + remotehtlc_sig + preimage_length + preimage + witness_script_length + witness_script
492 &InputDescriptors::OfferedHTLC => {
493 1 + 1 + 73 + 1 + 32 + 1 + 133
495 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
496 &InputDescriptors::ReceivedHTLC => {
497 1 + 1 + 73 + 1 + 1 + 1 + 139
499 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
500 &InputDescriptors::RevokedOutput => {
501 1 + 1 + 73 + 1 + 1 + 1 + 77
508 /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
509 /// 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
510 /// height than once reached we should generate a new bumped "version" of the claim tx to be sure than we safely claim outputs before
511 /// than our counterparty can do it too. If timelock expires soon, height timer is going to be scale down in consequence to increase
512 /// frequency of the bump and so increase our bets of success.
513 fn get_height_timer(current_height: u32, timelock_expiration: u32) -> u32 {
514 if timelock_expiration <= current_height + 3 {
515 return current_height + 1
516 } else if timelock_expiration - current_height <= 15 {
517 return current_height + 3
522 /// 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
523 /// (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.
524 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)>
525 where F::Target: FeeEstimator,
528 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
529 let mut inputs = Vec::new();
530 for outp in cached_claim_datas.per_input_material.keys() {
531 log_trace!(logger, "Outpoint {}:{}", outp.txid, outp.vout);
533 previous_output: *outp,
534 script_sig: Script::new(),
535 sequence: 0xfffffffd,
539 let mut bumped_tx = Transaction {
544 script_pubkey: self.destination_script.clone(),
549 macro_rules! RBF_bump {
550 ($amount: expr, $old_feerate: expr, $fee_estimator: expr, $predicted_weight: expr) => {
552 let mut used_feerate;
553 // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
554 let new_fee = if $old_feerate < $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) {
555 let mut value = $amount;
556 if subtract_high_prio_fee!(logger, $fee_estimator, value, $predicted_weight, used_feerate) {
557 // Overflow check is done in subtract_high_prio_fee
560 log_trace!(logger, "Can't new-estimation bump new claiming tx, amount {} is too small", $amount);
563 // ...else just increase the previous feerate by 25% (because that's a nice number)
565 let fee = $old_feerate * $predicted_weight / 750;
567 log_trace!(logger, "Can't 25% bump new claiming tx, amount {} is too small", $amount);
573 let previous_fee = $old_feerate * $predicted_weight / 1000;
574 let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * $predicted_weight / 1000;
575 // BIP 125 Opt-in Full Replace-by-Fee Signaling
576 // * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
577 // * 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.
578 let new_fee = if new_fee < previous_fee + min_relay_fee {
579 new_fee + previous_fee + min_relay_fee - new_fee
583 Some((new_fee, new_fee * 1000 / $predicted_weight))
588 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
589 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
590 let new_timer = Some(Self::get_height_timer(height, cached_claim_datas.soonest_timelock));
591 let mut inputs_witnesses_weight = 0;
593 let mut dynamic_fee = true;
594 for per_outp_material in cached_claim_datas.per_input_material.values() {
595 match per_outp_material {
596 &InputMaterial::Revoked { ref input_descriptor, ref amount, .. } => {
597 inputs_witnesses_weight += Self::get_witnesses_weight(&[*input_descriptor]);
600 &InputMaterial::RemoteHTLC { ref preimage, ref amount, .. } => {
601 inputs_witnesses_weight += Self::get_witnesses_weight(if preimage.is_some() { &[InputDescriptors::OfferedHTLC] } else { &[InputDescriptors::ReceivedHTLC] });
604 &InputMaterial::LocalHTLC { .. } => {
607 &InputMaterial::Funding { .. } => {
613 let predicted_weight = bumped_tx.get_weight() + inputs_witnesses_weight;
615 // If old feerate is 0, first iteration of this claim, use normal fee calculation
616 if cached_claim_datas.feerate_previous != 0 {
617 if let Some((new_fee, feerate)) = RBF_bump!(amt, cached_claim_datas.feerate_previous, fee_estimator, predicted_weight as u64) {
618 // If new computed fee is superior at the whole claimable amount burn all in fees
620 bumped_tx.output[0].value = 0;
622 bumped_tx.output[0].value = amt - new_fee;
624 new_feerate = feerate;
625 } else { return None; }
627 if subtract_high_prio_fee!(logger, fee_estimator, amt, predicted_weight, new_feerate) {
628 bumped_tx.output[0].value = amt;
629 } else { return None; }
631 assert!(new_feerate != 0);
633 for (i, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
634 match per_outp_material {
635 &InputMaterial::Revoked { ref per_commitment_point, ref key, ref input_descriptor, ref amount } => {
636 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) {
638 let mut this_htlc = None;
639 if *input_descriptor != InputDescriptors::RevokedOutput {
640 if let Some(htlcs) = self.remote_tx_cache.per_htlc.get(&outp.txid) {
642 if htlc.transaction_output_index.unwrap() == outp.vout {
643 this_htlc = Some(htlc);
649 let witness_script = if *input_descriptor != InputDescriptors::RevokedOutput && this_htlc.is_some() {
650 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)
651 } else if *input_descriptor != InputDescriptors::RevokedOutput {
654 chan_utils::get_revokeable_redeemscript(&chan_keys.revocation_key, self.remote_csv, &chan_keys.a_delayed_payment_key)
657 let sighash_parts = bip143::SighashComponents::new(&bumped_tx);
658 let sighash = hash_to_message!(&sighash_parts.sighash_all(&bumped_tx.input[i], &witness_script, *amount)[..]);
659 let sig = self.secp_ctx.sign(&sighash, &key);
660 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
661 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
662 if *input_descriptor != InputDescriptors::RevokedOutput {
663 bumped_tx.input[i].witness.push(chan_keys.revocation_key.clone().serialize().to_vec());
665 bumped_tx.input[i].witness.push(vec!(1));
667 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
668 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);
671 &InputMaterial::RemoteHTLC { ref witness_script, ref key, ref preimage, ref amount, ref locktime } => {
672 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
673 let sighash_parts = bip143::SighashComponents::new(&bumped_tx);
674 let sighash = hash_to_message!(&sighash_parts.sighash_all(&bumped_tx.input[i], &witness_script, *amount)[..]);
675 let sig = self.secp_ctx.sign(&sighash, &key);
676 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
677 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
678 if let &Some(preimage) = preimage {
679 bumped_tx.input[i].witness.push(preimage.clone().0.to_vec());
681 bumped_tx.input[i].witness.push(vec![]);
683 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
684 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);
689 log_trace!(logger, "...with timer {}", new_timer.unwrap());
690 assert!(predicted_weight >= bumped_tx.get_weight());
691 return Some((new_timer, new_feerate, bumped_tx))
693 for (_, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
694 match per_outp_material {
695 &InputMaterial::LocalHTLC { ref preimage, ref amount } => {
696 let htlc_tx = self.get_fully_signed_htlc_tx(outp, preimage);
697 if let Some(htlc_tx) = htlc_tx {
698 let feerate = (amount - htlc_tx.output[0].value) * 1000 / htlc_tx.get_weight() as u64;
699 // Timer set to $NEVER given we can't bump tx without anchor outputs
700 log_trace!(logger, "Going to broadcast Local HTLC-{} claiming HTLC output {} from {}...", if preimage.is_some() { "Success" } else { "Timeout" }, outp.vout, outp.txid);
701 return Some((None, feerate, htlc_tx));
705 &InputMaterial::Funding { ref funding_redeemscript } => {
706 let signed_tx = self.get_fully_signed_local_tx(funding_redeemscript).unwrap();
707 // Timer set to $NEVER given we can't bump tx without anchor outputs
708 log_trace!(logger, "Going to broadcast Local Transaction {} claiming funding output {} from {}...", signed_tx.txid(), outp.vout, outp.txid);
709 return Some((None, self.local_commitment.as_ref().unwrap().feerate_per_kw, signed_tx));
718 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)
719 where B::Target: BroadcasterInterface,
720 F::Target: FeeEstimator,
723 log_trace!(logger, "Block at height {} connected with {} claim requests", height, claimable_outpoints.len());
724 let mut new_claims = Vec::new();
725 let mut aggregated_claim = HashMap::new();
726 let mut aggregated_soonest = ::std::u32::MAX;
728 // Try to aggregate outputs if their timelock expiration isn't imminent (absolute_timelock
729 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
730 for req in claimable_outpoints {
731 // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
732 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 {
733 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.absolute_timelock, height + CLTV_SHARED_CLAIM_BUFFER);
734 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
735 let mut single_input = HashMap::new();
736 single_input.insert(req.outpoint, req.witness_data);
737 new_claims.push((req.absolute_timelock, single_input));
739 aggregated_claim.insert(req.outpoint, req.witness_data);
740 if req.absolute_timelock < aggregated_soonest {
741 aggregated_soonest = req.absolute_timelock;
746 new_claims.push((aggregated_soonest, aggregated_claim));
748 // Generate claim transactions and track them to bump if necessary at
749 // height timer expiration (i.e in how many blocks we're going to take action).
750 for (soonest_timelock, claim) in new_claims.drain(..) {
751 let mut claim_material = ClaimTxBumpMaterial { height_timer: None, feerate_previous: 0, soonest_timelock, per_input_material: claim };
752 if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
753 claim_material.height_timer = new_timer;
754 claim_material.feerate_previous = new_feerate;
755 let txid = tx.txid();
756 for k in claim_material.per_input_material.keys() {
757 log_trace!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
758 self.claimable_outpoints.insert(k.clone(), (txid, height));
760 self.pending_claim_requests.insert(txid, claim_material);
761 log_trace!(logger, "Broadcast onchain {}", log_tx!(tx));
762 broadcaster.broadcast_transaction(&tx);
766 let mut bump_candidates = HashMap::new();
767 for tx in txn_matched {
768 // Scan all input to verify is one of the outpoint spent is of interest for us
769 let mut claimed_outputs_material = Vec::new();
770 for inp in &tx.input {
771 if let Some(first_claim_txid_height) = self.claimable_outpoints.get(&inp.previous_output) {
772 // If outpoint has claim request pending on it...
773 if let Some(claim_material) = self.pending_claim_requests.get_mut(&first_claim_txid_height.0) {
774 //... we need to verify equality between transaction outpoints and claim request
775 // outpoints to know if transaction is the original claim or a bumped one issued
777 let mut set_equality = true;
778 if claim_material.per_input_material.len() != tx.input.len() {
779 set_equality = false;
781 for (claim_inp, tx_inp) in claim_material.per_input_material.keys().zip(tx.input.iter()) {
782 if *claim_inp != tx_inp.previous_output {
783 set_equality = false;
788 macro_rules! clean_claim_request_after_safety_delay {
790 let new_event = OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() };
791 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
792 hash_map::Entry::Occupied(mut entry) => {
793 if !entry.get().contains(&new_event) {
794 entry.get_mut().push(new_event);
797 hash_map::Entry::Vacant(entry) => {
798 entry.insert(vec![new_event]);
804 // If this is our transaction (or our counterparty spent all the outputs
805 // before we could anyway with same inputs order than us), wait for
806 // ANTI_REORG_DELAY and clean the RBF tracking map.
808 clean_claim_request_after_safety_delay!();
809 } else { // If false, generate new claim request with update outpoint set
810 let mut at_least_one_drop = false;
811 for input in tx.input.iter() {
812 if let Some(input_material) = claim_material.per_input_material.remove(&input.previous_output) {
813 claimed_outputs_material.push((input.previous_output, input_material));
814 at_least_one_drop = true;
816 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
817 if claim_material.per_input_material.is_empty() {
818 clean_claim_request_after_safety_delay!();
821 //TODO: recompute soonest_timelock to avoid wasting a bit on fees
822 if at_least_one_drop {
823 bump_candidates.insert(first_claim_txid_height.0.clone(), claim_material.clone());
826 break; //No need to iterate further, either tx is our or their
828 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
832 for (outpoint, input_material) in claimed_outputs_material.drain(..) {
833 let new_event = OnchainEvent::ContentiousOutpoint { outpoint, input_material };
834 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
835 hash_map::Entry::Occupied(mut entry) => {
836 if !entry.get().contains(&new_event) {
837 entry.get_mut().push(new_event);
840 hash_map::Entry::Vacant(entry) => {
841 entry.insert(vec![new_event]);
847 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
848 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
851 OnchainEvent::Claim { claim_request } => {
852 // We may remove a whole set of claim outpoints here, as these one may have
853 // been aggregated in a single tx and claimed so atomically
854 if let Some(bump_material) = self.pending_claim_requests.remove(&claim_request) {
855 for outpoint in bump_material.per_input_material.keys() {
856 self.claimable_outpoints.remove(&outpoint);
860 OnchainEvent::ContentiousOutpoint { outpoint, .. } => {
861 self.claimable_outpoints.remove(&outpoint);
867 // Check if any pending claim request must be rescheduled
868 for (first_claim_txid, ref claim_data) in self.pending_claim_requests.iter() {
869 if let Some(h) = claim_data.height_timer {
871 bump_candidates.insert(*first_claim_txid, (*claim_data).clone());
876 // Build, bump and rebroadcast tx accordingly
877 log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
878 for (first_claim_txid, claim_material) in bump_candidates.iter() {
879 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
880 log_trace!(logger, "Broadcast onchain {}", log_tx!(bump_tx));
881 broadcaster.broadcast_transaction(&bump_tx);
882 if let Some(claim_material) = self.pending_claim_requests.get_mut(first_claim_txid) {
883 claim_material.height_timer = new_timer;
884 claim_material.feerate_previous = new_feerate;
890 pub(super) fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: F, logger: L)
891 where B::Target: BroadcasterInterface,
892 F::Target: FeeEstimator,
895 let mut bump_candidates = HashMap::new();
896 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
897 //- our claim tx on a commitment tx output
898 //- resurect outpoint back in its claimable set and regenerate tx
901 OnchainEvent::ContentiousOutpoint { outpoint, input_material } => {
902 if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&outpoint) {
903 if let Some(claim_material) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) {
904 claim_material.per_input_material.insert(outpoint, input_material);
905 // Using a HashMap guarantee us than if we have multiple outpoints getting
906 // resurrected only one bump claim tx is going to be broadcast
907 bump_candidates.insert(ancestor_claimable_txid.clone(), claim_material.clone());
915 for (_, claim_material) in bump_candidates.iter_mut() {
916 if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
917 claim_material.height_timer = new_timer;
918 claim_material.feerate_previous = new_feerate;
919 broadcaster.broadcast_transaction(&bump_tx);
922 for (ancestor_claim_txid, claim_material) in bump_candidates.drain() {
923 self.pending_claim_requests.insert(ancestor_claim_txid.0, claim_material);
925 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
926 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
927 let mut remove_request = Vec::new();
928 self.claimable_outpoints.retain(|_, ref v|
930 remove_request.push(v.0.clone());
933 for req in remove_request {
934 self.pending_claim_requests.remove(&req);
938 pub(super) fn provide_latest_local_tx(&mut self, tx: LocalCommitmentTransaction) -> Result<(), ()> {
939 // To prevent any unsafe state discrepancy between offchain and onchain, once local
940 // commitment transaction has been signed due to an event (either block height for
941 // HTLC-timeout or channel force-closure), don't allow any further update of local
942 // commitment transaction view to avoid delivery of revocation secret to counterparty
943 // for the aformentionned signed transaction.
944 if self.local_htlc_sigs.is_some() || self.prev_local_htlc_sigs.is_some() {
947 self.prev_local_commitment = self.local_commitment.take();
948 self.local_commitment = Some(tx);
952 fn sign_latest_local_htlcs(&mut self) {
953 if let Some(ref local_commitment) = self.local_commitment {
954 if let Ok(sigs) = self.key_storage.sign_local_commitment_htlc_transactions(local_commitment, self.local_csv, &self.secp_ctx) {
955 self.local_htlc_sigs = Some(Vec::new());
956 let ret = self.local_htlc_sigs.as_mut().unwrap();
957 for (htlc_idx, (local_sig, &(ref htlc, _))) in sigs.iter().zip(local_commitment.per_htlc.iter()).enumerate() {
958 if let Some(tx_idx) = htlc.transaction_output_index {
959 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
960 ret[tx_idx as usize] = Some((htlc_idx, local_sig.expect("Did not receive a signature for a non-dust HTLC")));
962 assert!(local_sig.is_none(), "Received a signature for a dust HTLC");
968 fn sign_prev_local_htlcs(&mut self) {
969 if let Some(ref local_commitment) = self.prev_local_commitment {
970 if let Ok(sigs) = self.key_storage.sign_local_commitment_htlc_transactions(local_commitment, self.local_csv, &self.secp_ctx) {
971 self.prev_local_htlc_sigs = Some(Vec::new());
972 let ret = self.prev_local_htlc_sigs.as_mut().unwrap();
973 for (htlc_idx, (local_sig, &(ref htlc, _))) in sigs.iter().zip(local_commitment.per_htlc.iter()).enumerate() {
974 if let Some(tx_idx) = htlc.transaction_output_index {
975 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
976 ret[tx_idx as usize] = Some((htlc_idx, local_sig.expect("Did not receive a signature for a non-dust HTLC")));
978 assert!(local_sig.is_none(), "Received a signature for a dust HTLC");
985 //TODO: getting lastest local transactions should be infaillible and result in us "force-closing the channel", but we may
986 // have empty local commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
987 // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
988 // to monitor before.
989 pub(super) fn get_fully_signed_local_tx(&mut self, funding_redeemscript: &Script) -> Option<Transaction> {
990 if let Some(ref mut local_commitment) = self.local_commitment {
991 match self.key_storage.sign_local_commitment(local_commitment, &self.secp_ctx) {
992 Ok(sig) => Some(local_commitment.add_local_sig(funding_redeemscript, sig)),
993 Err(_) => return None,
1000 pub(super) fn provide_latest_remote_tx(&mut self, commitment_txid: Txid, htlcs: Vec<HTLCOutputInCommitment>) {
1001 self.remote_tx_cache.per_htlc.insert(commitment_txid, htlcs);
1005 pub(super) fn get_fully_signed_copy_local_tx(&mut self, funding_redeemscript: &Script) -> Option<Transaction> {
1006 if let Some(ref mut local_commitment) = self.local_commitment {
1007 let local_commitment = local_commitment.clone();
1008 match self.key_storage.sign_local_commitment(&local_commitment, &self.secp_ctx) {
1009 Ok(sig) => Some(local_commitment.add_local_sig(funding_redeemscript, sig)),
1010 Err(_) => return None,
1017 pub(super) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
1018 let mut htlc_tx = None;
1019 if self.local_commitment.is_some() {
1020 let commitment_txid = self.local_commitment.as_ref().unwrap().txid();
1021 if commitment_txid == outp.txid {
1022 self.sign_latest_local_htlcs();
1023 if let &Some(ref htlc_sigs) = &self.local_htlc_sigs {
1024 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
1025 htlc_tx = Some(self.local_commitment.as_ref().unwrap()
1026 .get_signed_htlc_tx(*htlc_idx, htlc_sig, preimage, self.local_csv));
1030 if self.prev_local_commitment.is_some() {
1031 let commitment_txid = self.prev_local_commitment.as_ref().unwrap().txid();
1032 if commitment_txid == outp.txid {
1033 self.sign_prev_local_htlcs();
1034 if let &Some(ref htlc_sigs) = &self.prev_local_htlc_sigs {
1035 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
1036 htlc_tx = Some(self.prev_local_commitment.as_ref().unwrap()
1037 .get_signed_htlc_tx(*htlc_idx, htlc_sig, preimage, self.local_csv));
1045 pub(super) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
1046 let latest_had_sigs = self.local_htlc_sigs.is_some();
1047 let prev_had_sigs = self.prev_local_htlc_sigs.is_some();
1048 let ret = self.get_fully_signed_htlc_tx(outp, preimage);
1049 if !latest_had_sigs {
1050 self.local_htlc_sigs = None;
1053 self.prev_local_htlc_sigs = None;