1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
10 //! Various utilities to assemble claimable outpoints in package of one or more transactions. Those
11 //! packages are attached metadata, guiding their aggregable or fee-bumping re-schedule. This file
12 //! also includes witness weight computation and fee computation methods.
14 use bitcoin::blockdata::constants::WITNESS_SCALE_FACTOR;
15 use bitcoin::blockdata::transaction::{TxOut,TxIn, Transaction, SigHashType};
16 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
17 use bitcoin::blockdata::script::Script;
19 use bitcoin::hash_types::Txid;
21 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
23 use ln::PaymentPreimage;
24 use ln::chan_utils::{TxCreationKeys, HTLCOutputInCommitment, HTLC_OUTPUT_IN_COMMITMENT_SIZE};
26 use ln::msgs::DecodeError;
27 use ln::onchaintx::OnchainTxHandler;
28 use chain::chaininterface::{FeeEstimator, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT};
29 use chain::keysinterface::Sign;
31 use util::logger::Logger;
32 use util::ser::{Readable, Writer, Writeable};
38 const MAX_ALLOC_SIZE: usize = 64*1024;
41 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
42 pub(crate) const WEIGHT_REVOKED_OFFERED_HTLC: u64 = 1 + 1 + 73 + 1 + 33 + 1 + 133;
43 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
44 pub(crate) const WEIGHT_REVOKED_RECEIVED_HTLC: u64 = 1 + 1 + 73 + 1 + 33 + 1 + 139;
45 // number_of_witness_elements + sig_length + counterpartyhtlc_sig + preimage_length + preimage + witness_script_length + witness_script
46 pub(crate) const WEIGHT_OFFERED_HTLC: u64 = 1 + 1 + 73 + 1 + 32 + 1 + 133;
47 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
48 pub(crate) const WEIGHT_RECEIVED_HTLC: u64 = 1 + 1 + 73 + 1 + 1 + 1 + 139;
49 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
50 pub(crate) const WEIGHT_REVOKED_OUTPUT: u64 = 1 + 1 + 73 + 1 + 1 + 1 + 77;
52 /// A struct to describe a revoked output and corresponding information to generate a solving
53 /// witness spending a commitment `to_local` output or a second-stage HTLC transaction output.
55 /// CSV and pubkeys are used as part of a witnessScript redeeming a balance output, amount is used
56 /// as part of the signature hash and revocation secret to generate a satisfying witness.
57 #[derive(Clone, PartialEq)]
58 pub(crate) struct RevokedOutput {
59 per_commitment_point: PublicKey,
60 counterparty_delayed_payment_base_key: PublicKey,
61 counterparty_htlc_base_key: PublicKey,
62 per_commitment_key: SecretKey,
65 on_counterparty_tx_csv: u16,
69 pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: PublicKey, counterparty_htlc_base_key: PublicKey, per_commitment_key: SecretKey, amount: u64, on_counterparty_tx_csv: u16) -> Self {
72 counterparty_delayed_payment_base_key,
73 counterparty_htlc_base_key,
75 weight: WEIGHT_REVOKED_OUTPUT,
77 on_counterparty_tx_csv
82 impl_writeable!(RevokedOutput, 33*3 + 32 + 8 + 8 + 2, {
84 counterparty_delayed_payment_base_key,
85 counterparty_htlc_base_key,
89 on_counterparty_tx_csv
92 /// A struct to describe a revoked offered output and corresponding information to generate a
95 /// HTLCOuputInCommitment (hash timelock, direction) and pubkeys are used to generate a suitable
98 /// CSV is used as part of a witnessScript redeeming a balance output, amount is used as part
99 /// of the signature hash and revocation secret to generate a satisfying witness.
100 #[derive(Clone, PartialEq)]
101 pub(crate) struct RevokedHTLCOutput {
102 per_commitment_point: PublicKey,
103 counterparty_delayed_payment_base_key: PublicKey,
104 counterparty_htlc_base_key: PublicKey,
105 per_commitment_key: SecretKey,
108 htlc: HTLCOutputInCommitment,
111 impl RevokedHTLCOutput {
112 pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: PublicKey, counterparty_htlc_base_key: PublicKey, per_commitment_key: SecretKey, amount: u64, htlc: HTLCOutputInCommitment) -> Self {
113 let weight = if htlc.offered { WEIGHT_REVOKED_OFFERED_HTLC } else { WEIGHT_REVOKED_RECEIVED_HTLC };
115 per_commitment_point,
116 counterparty_delayed_payment_base_key,
117 counterparty_htlc_base_key,
126 impl_writeable!(RevokedHTLCOutput, 33*3 + 32 + 8 + 8 + HTLC_OUTPUT_IN_COMMITMENT_SIZE, {
127 per_commitment_point,
128 counterparty_delayed_payment_base_key,
129 counterparty_htlc_base_key,
136 /// A struct to describe a HTLC output on a counterparty commitment transaction.
138 /// HTLCOutputInCommitment (hash, timelock, directon) and pubkeys are used to generate a suitable
141 /// The preimage is used as part of the witness.
142 #[derive(Clone, PartialEq)]
143 pub(crate) struct CounterpartyOfferedHTLCOutput {
144 per_commitment_point: PublicKey,
145 counterparty_delayed_payment_base_key: PublicKey,
146 counterparty_htlc_base_key: PublicKey,
147 preimage: PaymentPreimage,
148 htlc: HTLCOutputInCommitment
151 impl CounterpartyOfferedHTLCOutput {
152 pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: PublicKey, counterparty_htlc_base_key: PublicKey, preimage: PaymentPreimage, htlc: HTLCOutputInCommitment) -> Self {
153 CounterpartyOfferedHTLCOutput {
154 per_commitment_point,
155 counterparty_delayed_payment_base_key,
156 counterparty_htlc_base_key,
163 impl_writeable!(CounterpartyOfferedHTLCOutput, 33*3 + 32 + HTLC_OUTPUT_IN_COMMITMENT_SIZE, {
164 per_commitment_point,
165 counterparty_delayed_payment_base_key,
166 counterparty_htlc_base_key,
171 /// A struct to describe a HTLC output on a counterparty commitment transaction.
173 /// HTLCOutputInCommitment (hash, timelock, directon) and pubkeys are used to generate a suitable
175 #[derive(Clone, PartialEq)]
176 pub(crate) struct CounterpartyReceivedHTLCOutput {
177 per_commitment_point: PublicKey,
178 counterparty_delayed_payment_base_key: PublicKey,
179 counterparty_htlc_base_key: PublicKey,
180 htlc: HTLCOutputInCommitment
183 impl CounterpartyReceivedHTLCOutput {
184 pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: PublicKey, counterparty_htlc_base_key: PublicKey, htlc: HTLCOutputInCommitment) -> Self {
185 CounterpartyReceivedHTLCOutput {
186 per_commitment_point,
187 counterparty_delayed_payment_base_key,
188 counterparty_htlc_base_key,
194 impl_writeable!(CounterpartyReceivedHTLCOutput, 33*3 + HTLC_OUTPUT_IN_COMMITMENT_SIZE, {
195 per_commitment_point,
196 counterparty_delayed_payment_base_key,
197 counterparty_htlc_base_key,
201 /// A struct to describe a HTLC output on holder commitment transaction.
203 /// Either offered or received, the amount is always used as part of the bip143 sighash.
204 /// Preimage is only included as part of the witness in former case.
205 #[derive(Clone, PartialEq)]
206 pub(crate) struct HolderHTLCOutput {
207 preimage: Option<PaymentPreimage>,
211 impl HolderHTLCOutput {
212 pub(crate) fn build(preimage: Option<PaymentPreimage>, amount: u64) -> Self {
220 impl_writeable!(HolderHTLCOutput, 0, {
225 /// A struct to describe the channel output on the funding transaction.
227 /// witnessScript is used as part of the witness redeeming the funding utxo.
228 #[derive(Clone, PartialEq)]
229 pub(crate) struct HolderFundingOutput {
230 funding_redeemscript: Script,
233 impl HolderFundingOutput {
234 pub(crate) fn build(funding_redeemscript: Script) -> Self {
235 HolderFundingOutput {
236 funding_redeemscript,
241 impl_writeable!(HolderFundingOutput, 0, {
245 /// A wrapper encapsulating all in-protocol differing outputs types.
247 /// The generic API offers access to an outputs common attributes or allow transformation such as
248 /// finalizing an input claiming the output.
249 #[derive(Clone, PartialEq)]
250 pub(crate) enum PackageSolvingData {
251 RevokedOutput(RevokedOutput),
252 RevokedHTLCOutput(RevokedHTLCOutput),
253 CounterpartyOfferedHTLCOutput(CounterpartyOfferedHTLCOutput),
254 CounterpartyReceivedHTLCOutput(CounterpartyReceivedHTLCOutput),
255 HolderHTLCOutput(HolderHTLCOutput),
256 HolderFundingOutput(HolderFundingOutput),
259 impl PackageSolvingData {
260 fn amount(&self) -> u64 {
261 let amt = match self {
262 PackageSolvingData::RevokedOutput(ref outp) => { outp.amount },
263 PackageSolvingData::RevokedHTLCOutput(ref outp) => { outp.amount },
264 PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => { outp.htlc.amount_msat / 1000 },
265 PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => { outp.htlc.amount_msat / 1000 },
266 // Note: Currently, amounts of holder outputs spending witnesses aren't used
267 // as we can't malleate spending package to increase their feerate. This
268 // should change with the remaining anchor output patchset.
269 PackageSolvingData::HolderHTLCOutput(..) => { 0 },
270 PackageSolvingData::HolderFundingOutput(..) => { 0 },
274 fn weight(&self) -> usize {
275 let weight = match self {
276 PackageSolvingData::RevokedOutput(ref outp) => { outp.weight as usize },
277 PackageSolvingData::RevokedHTLCOutput(ref outp) => { outp.weight as usize },
278 PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => { WEIGHT_OFFERED_HTLC as usize },
279 PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => { WEIGHT_RECEIVED_HTLC as usize },
280 // Note: Currently, weights of holder outputs spending witnesses aren't used
281 // as we can't malleate spending package to increase their feerate. This
282 // should change with the remaining anchor output patchset.
283 PackageSolvingData::HolderHTLCOutput(..) => { debug_assert!(false); 0 },
284 PackageSolvingData::HolderFundingOutput(..) => { debug_assert!(false); 0 },
288 fn is_compatible(&self, input: &PackageSolvingData) -> bool {
290 PackageSolvingData::RevokedOutput(..) => {
292 PackageSolvingData::RevokedHTLCOutput(..) => { true },
293 PackageSolvingData::RevokedOutput(..) => { true },
297 PackageSolvingData::RevokedHTLCOutput(..) => {
299 PackageSolvingData::RevokedOutput(..) => { true },
300 PackageSolvingData::RevokedHTLCOutput(..) => { true },
304 _ => { mem::discriminant(self) == mem::discriminant(&input) }
307 fn finalize_input<Signer: Sign>(&self, bumped_tx: &mut Transaction, i: usize, onchain_handler: &mut OnchainTxHandler<Signer>) -> bool {
309 PackageSolvingData::RevokedOutput(ref outp) => {
310 if let Ok(chan_keys) = TxCreationKeys::derive_new(&onchain_handler.secp_ctx, &outp.per_commitment_point, &outp.counterparty_delayed_payment_base_key, &outp.counterparty_htlc_base_key, &onchain_handler.signer.pubkeys().revocation_basepoint, &onchain_handler.signer.pubkeys().htlc_basepoint) {
311 let witness_script = chan_utils::get_revokeable_redeemscript(&chan_keys.revocation_key, outp.on_counterparty_tx_csv, &chan_keys.broadcaster_delayed_payment_key);
312 //TODO: should we panic on signer failure ?
313 if let Ok(sig) = onchain_handler.signer.sign_justice_revoked_output(&bumped_tx, i, outp.amount, &outp.per_commitment_key, &onchain_handler.secp_ctx) {
314 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
315 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
316 bumped_tx.input[i].witness.push(vec!(1));
317 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
318 } else { return false; }
321 PackageSolvingData::RevokedHTLCOutput(ref outp) => {
322 if let Ok(chan_keys) = TxCreationKeys::derive_new(&onchain_handler.secp_ctx, &outp.per_commitment_point, &outp.counterparty_delayed_payment_base_key, &outp.counterparty_htlc_base_key, &onchain_handler.signer.pubkeys().revocation_basepoint, &onchain_handler.signer.pubkeys().htlc_basepoint) {
323 let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
324 //TODO: should we panic on signer failure ?
325 if let Ok(sig) = onchain_handler.signer.sign_justice_revoked_htlc(&bumped_tx, i, outp.amount, &outp.per_commitment_key, &outp.htlc, &onchain_handler.secp_ctx) {
326 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
327 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
328 bumped_tx.input[i].witness.push(chan_keys.revocation_key.clone().serialize().to_vec());
329 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
330 } else { return false; }
333 PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => {
334 if let Ok(chan_keys) = TxCreationKeys::derive_new(&onchain_handler.secp_ctx, &outp.per_commitment_point, &outp.counterparty_delayed_payment_base_key, &outp.counterparty_htlc_base_key, &onchain_handler.signer.pubkeys().revocation_basepoint, &onchain_handler.signer.pubkeys().htlc_basepoint) {
335 let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
337 if let Ok(sig) = onchain_handler.signer.sign_counterparty_htlc_transaction(&bumped_tx, i, &outp.htlc.amount_msat / 1000, &outp.per_commitment_point, &outp.htlc, &onchain_handler.secp_ctx) {
338 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
339 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
340 bumped_tx.input[i].witness.push(outp.preimage.0.to_vec());
341 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
345 PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => {
346 if let Ok(chan_keys) = TxCreationKeys::derive_new(&onchain_handler.secp_ctx, &outp.per_commitment_point, &outp.counterparty_delayed_payment_base_key, &outp.counterparty_htlc_base_key, &onchain_handler.signer.pubkeys().revocation_basepoint, &onchain_handler.signer.pubkeys().htlc_basepoint) {
347 let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
349 bumped_tx.lock_time = outp.htlc.cltv_expiry; // Right now we don't aggregate time-locked transaction, if we do we should set lock_time before to avoid breaking hash computation
350 if let Ok(sig) = onchain_handler.signer.sign_counterparty_htlc_transaction(&bumped_tx, i, &outp.htlc.amount_msat / 1000, &outp.per_commitment_point, &outp.htlc, &onchain_handler.secp_ctx) {
351 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
352 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
353 // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
354 bumped_tx.input[i].witness.push(vec![]);
355 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
359 _ => { panic!("API Error!"); }
363 fn get_finalized_tx<Signer: Sign>(&self, outpoint: &BitcoinOutPoint, onchain_handler: &mut OnchainTxHandler<Signer>) -> Option<Transaction> {
365 PackageSolvingData::HolderHTLCOutput(ref outp) => { return onchain_handler.get_fully_signed_htlc_tx(outpoint, &outp.preimage); }
366 PackageSolvingData::HolderFundingOutput(ref outp) => { return Some(onchain_handler.get_fully_signed_holder_tx(&outp.funding_redeemscript)); }
367 _ => { panic!("API Error!"); }
372 impl Writeable for PackageSolvingData {
373 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
375 PackageSolvingData::RevokedOutput(ref revoked_outp) => {
377 revoked_outp.write(writer)?;
379 PackageSolvingData::RevokedHTLCOutput(ref revoked_outp) => {
381 revoked_outp.write(writer)?;
383 PackageSolvingData::CounterpartyOfferedHTLCOutput(ref counterparty_outp) => {
385 counterparty_outp.write(writer)?;
387 PackageSolvingData::CounterpartyReceivedHTLCOutput(ref counterparty_outp) => {
389 counterparty_outp.write(writer)?;
391 PackageSolvingData::HolderHTLCOutput(ref holder_outp) => {
393 holder_outp.write(writer)?;
395 PackageSolvingData::HolderFundingOutput(ref funding_outp) => {
397 funding_outp.write(writer)?;
404 impl Readable for PackageSolvingData {
405 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
406 let byte = <u8 as Readable>::read(reader)?;
407 let solving_data = match byte {
409 PackageSolvingData::RevokedOutput(Readable::read(reader)?)
412 PackageSolvingData::RevokedHTLCOutput(Readable::read(reader)?)
415 PackageSolvingData::CounterpartyOfferedHTLCOutput(Readable::read(reader)?)
418 PackageSolvingData::CounterpartyReceivedHTLCOutput(Readable::read(reader)?)
421 PackageSolvingData::HolderHTLCOutput(Readable::read(reader)?)
424 PackageSolvingData::HolderFundingOutput(Readable::read(reader)?)
426 _ => return Err(DecodeError::UnknownVersion)
432 /// A malleable package might be aggregated with other packages to save on fees.
433 /// A untractable package has been counter-signed and aggregable will break cached counterparty
435 #[derive(Clone, PartialEq)]
436 pub(crate) enum PackageMalleability {
441 /// A structure to describe a package content that is generated by ChannelMonitor and
442 /// used by OnchainTxHandler to generate and broadcast transactions settling onchain claims.
444 /// A package is defined as one or more transactions claiming onchain outputs in reaction
445 /// to confirmation of a channel transaction. Those packages might be aggregated to save on
446 /// fees, if satisfaction of outputs's witnessScript let's us do so.
448 /// As packages are time-sensitive, we fee-bump and rebroadcast them at scheduled intervals.
449 /// Failing to confirm a package translate as a loss of funds for the user.
450 #[derive(Clone, PartialEq)]
451 pub struct PackageTemplate {
452 // List of onchain outputs and solving data to generate satisfying witnesses.
453 inputs: Vec<(BitcoinOutPoint, PackageSolvingData)>,
454 // Packages are deemed as malleable if we have local knwoledge of at least one set of
455 // private keys yielding a satisfying witnesses. Malleability implies that we can aggregate
456 // packages among them to save on fees or rely on RBF to bump their feerates.
457 // Untractable packages have been counter-signed and thus imply that we can't aggregate
458 // them without breaking signatures. Fee-bumping strategy will also rely on CPFP.
459 malleability: PackageMalleability,
460 // Block height after which the earlier-output belonging to this package is mature for a
461 // competing claim by the counterparty. As our chain tip becomes nearer from the timelock,
462 // the fee-bumping frequency will increase. See `OnchainTxHandler::get_height_timer`.
463 soonest_conf_deadline: u32,
464 // Determines if this package can be aggregated.
465 // Timelocked outputs belonging to the same transaction might have differing
466 // satisfying heights. Picking up the later height among the output set would be a valid
467 // aggregable strategy but it comes with at least 2 trade-offs :
468 // * earlier-output fund are going to take longer to come back
469 // * CLTV delta backing up a corresponding HTLC on an upstream channel could be swallowed
470 // by the requirement of the later-output part of the set
471 // For now, we mark such timelocked outputs as non-aggregable, though we might introduce
472 // smarter aggregable strategy in the future.
474 // Cache of package feerate committed at previous (re)broadcast. If bumping resources
475 // (either claimed output value or external utxo), it will keep increasing until holder
476 // or counterparty successful claim.
477 feerate_previous: u64,
478 // Cache of next height at which fee-bumping and rebroadcast will be attempted. In
479 // the future, we might abstract it to an observed mempool fluctuation.
480 height_timer: Option<u32>,
481 // Confirmation height of the claimed outputs set transaction. In case of reorg reaching
482 // it, we wipe out and forget the package.
483 height_original: u32,
486 impl PackageTemplate {
487 pub(crate) fn is_malleable(&self) -> bool {
488 self.malleability == PackageMalleability::Malleable
490 pub(crate) fn timelock(&self) -> u32 {
491 self.soonest_conf_deadline
493 pub(crate) fn aggregable(&self) -> bool {
496 pub(crate) fn feerate(&self) -> u64 {
497 self.feerate_previous
499 pub(crate) fn set_feerate(&mut self, new_feerate: u64) {
500 self.feerate_previous = new_feerate;
502 pub(crate) fn timer(&self) -> Option<u32> {
503 if let Some(ref timer) = self.height_timer {
508 pub(crate) fn set_timer(&mut self, new_timer: Option<u32>) {
509 self.height_timer = new_timer;
511 pub(crate) fn outpoints(&self) -> Vec<&BitcoinOutPoint> {
512 self.inputs.iter().map(|(o, _)| o).collect()
514 pub(crate) fn split_package(&mut self, split_outp: &BitcoinOutPoint) -> Option<PackageTemplate> {
515 match self.malleability {
516 PackageMalleability::Malleable => {
517 let mut split_package = None;
518 let timelock = self.soonest_conf_deadline;
519 let aggregable = self.aggregable;
520 let feerate_previous = self.feerate_previous;
521 let height_timer = self.height_timer;
522 let height_original = self.height_original;
523 self.inputs.retain(|outp| {
524 if *split_outp == outp.0 {
525 split_package = Some(PackageTemplate {
526 inputs: vec![(outp.0, outp.1.clone())],
527 malleability: PackageMalleability::Malleable,
528 soonest_conf_deadline: timelock,
538 return split_package;
541 // Note, we may try to split on remote transaction for
542 // which we don't have a competing one (HTLC-Success before
543 // timelock expiration). This explain we don't panic!
544 // We should refactor OnchainTxHandler::block_connected to
545 // only test equality on competing claims.
550 pub(crate) fn merge_package(&mut self, mut merge_from: PackageTemplate) {
551 assert_eq!(self.height_original, merge_from.height_original);
552 if self.malleability == PackageMalleability::Untractable || merge_from.malleability == PackageMalleability::Untractable {
553 panic!("Merging template on untractable packages");
555 if !self.aggregable || !merge_from.aggregable {
556 panic!("Merging non aggregatable packages");
558 if let Some((_, lead_input)) = self.inputs.first() {
559 for (_, v) in merge_from.inputs.iter() {
560 if !lead_input.is_compatible(v) { panic!("Merging outputs from differing types !"); }
562 } else { panic!("Merging template on an empty package"); }
563 for (k, v) in merge_from.inputs.drain(..) {
564 self.inputs.push((k, v));
566 //TODO: verify coverage and sanity?
567 if self.soonest_conf_deadline > merge_from.soonest_conf_deadline {
568 self.soonest_conf_deadline = merge_from.soonest_conf_deadline;
570 if self.feerate_previous > merge_from.feerate_previous {
571 self.feerate_previous = merge_from.feerate_previous;
573 self.height_timer = cmp::min(self.height_timer, merge_from.height_timer);
575 pub(crate) fn package_amount(&self) -> u64 {
577 for (_, outp) in self.inputs.iter() {
578 amounts += outp.amount();
582 pub(crate) fn package_weight(&self, destination_script: &Script) -> usize {
583 let mut inputs_weight = 0;
584 let mut witnesses_weight = 2; // count segwit flags
585 for (_, outp) in self.inputs.iter() {
586 // previous_out_point: 36 bytes ; var_int: 1 byte ; sequence: 4 bytes
587 inputs_weight += 41 * WITNESS_SCALE_FACTOR;
588 witnesses_weight += outp.weight();
590 // version: 4 bytes ; count_tx_in: 1 byte ; count_tx_out: 1 byte ; lock_time: 4 bytes
591 let transaction_weight = 10 * WITNESS_SCALE_FACTOR;
592 // value: 8 bytes ; var_int: 1 byte ; pk_script: `destination_script.len()`
593 let output_weight = (8 + 1 + destination_script.len()) * WITNESS_SCALE_FACTOR;
594 inputs_weight + witnesses_weight + transaction_weight + output_weight
596 pub(crate) fn finalize_package<L: Deref, Signer: Sign>(&self, onchain_handler: &mut OnchainTxHandler<Signer>, value: u64, destination_script: Script, logger: &L) -> Option<Transaction>
597 where L::Target: Logger,
599 match self.malleability {
600 PackageMalleability::Malleable => {
601 let mut bumped_tx = Transaction {
606 script_pubkey: destination_script,
610 for (outpoint, _) in self.inputs.iter() {
611 bumped_tx.input.push(TxIn {
612 previous_output: *outpoint,
613 script_sig: Script::new(),
614 sequence: 0xfffffffd,
618 for (i, (outpoint, out)) in self.inputs.iter().enumerate() {
619 log_trace!(logger, "Adding claiming input for outpoint {}:{}", outpoint.txid, outpoint.vout);
620 if !out.finalize_input(&mut bumped_tx, i, onchain_handler) { return None; }
622 log_trace!(logger, "Finalized transaction {} ready to broadcast", bumped_tx.txid());
623 return Some(bumped_tx);
625 PackageMalleability::Untractable => {
626 if let Some((outpoint, outp)) = self.inputs.first() {
627 if let Some(final_tx) = outp.get_finalized_tx(outpoint, onchain_handler) {
628 log_trace!(logger, "Adding claiming input for outpoint {}:{}", outpoint.txid, outpoint.vout);
629 log_trace!(logger, "Finalized transaction {} ready to broadcast", final_tx.txid());
630 return Some(final_tx);
633 } else { panic!("API Error: Package must not be inputs empty"); }
637 pub (crate) fn build_package(txid: Txid, vout: u32, input_solving_data: PackageSolvingData, soonest_conf_deadline: u32, aggregable: bool, height_original: u32) -> Self {
638 let malleability = match input_solving_data {
639 PackageSolvingData::RevokedOutput(..) => { PackageMalleability::Malleable },
640 PackageSolvingData::RevokedHTLCOutput(..) => { PackageMalleability::Malleable },
641 PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => { PackageMalleability::Malleable },
642 PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => { PackageMalleability::Malleable },
643 PackageSolvingData::HolderHTLCOutput(..) => { PackageMalleability::Untractable },
644 PackageSolvingData::HolderFundingOutput(..) => { PackageMalleability::Untractable },
646 let mut inputs = Vec::with_capacity(1);
647 inputs.push((BitcoinOutPoint { txid, vout }, input_solving_data));
651 soonest_conf_deadline,
660 impl Writeable for PackageTemplate {
661 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
662 writer.write_all(&byte_utils::be64_to_array(self.inputs.len() as u64))?;
663 for (ref outpoint, ref rev_outp) in self.inputs.iter() {
664 outpoint.write(writer)?;
665 rev_outp.write(writer)?;
667 self.soonest_conf_deadline.write(writer)?;
668 self.feerate_previous.write(writer)?;
669 self.height_timer.write(writer)?;
670 self.height_original.write(writer)?;
675 impl Readable for PackageTemplate {
676 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
677 let inputs_count = <u64 as Readable>::read(reader)?;
678 let mut inputs: Vec<(BitcoinOutPoint, PackageSolvingData)> = Vec::with_capacity(cmp::min(inputs_count as usize, MAX_ALLOC_SIZE / 128));
679 for _ in 0..inputs_count {
680 let outpoint = Readable::read(reader)?;
681 let rev_outp = Readable::read(reader)?;
682 inputs.push((outpoint, rev_outp));
684 let (malleability, aggregable) = if let Some((_, lead_input)) = inputs.first() {
686 PackageSolvingData::RevokedOutput(..) => { (PackageMalleability::Malleable, true) },
687 PackageSolvingData::RevokedHTLCOutput(..) => { (PackageMalleability::Malleable, true) },
688 PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => { (PackageMalleability::Malleable, true) },
689 PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => { (PackageMalleability::Malleable, false) },
690 PackageSolvingData::HolderHTLCOutput(..) => { (PackageMalleability::Untractable, false) },
691 PackageSolvingData::HolderFundingOutput(..) => { (PackageMalleability::Untractable, false) },
693 } else { return Err(DecodeError::InvalidValue); };
694 let soonest_conf_deadline = Readable::read(reader)?;
695 let feerate_previous = Readable::read(reader)?;
696 let height_timer = Readable::read(reader)?;
697 let height_original = Readable::read(reader)?;
701 soonest_conf_deadline,
710 /// Attempt to propose a bumping fee for a transaction from its spent output's values and predicted
711 /// weight. We start with the highest priority feerate returned by the node's fee estimator then
712 /// fall-back to lower priorities until we have enough value available to suck from.
714 /// If the proposed fee is less than the available spent output's values, we return the proposed
715 /// fee and the corresponding updated feerate. If the proposed fee is equal or more than the
716 /// available spent output's values, we return nothing
717 fn compute_fee_from_spent_amounts<F: Deref, L: Deref>(input_amounts: u64, predicted_weight: usize, fee_estimator: &F, logger: &L) -> Option<(u64, u64)>
718 where F::Target: FeeEstimator,
721 let mut updated_feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) as u64;
722 let mut fee = updated_feerate * (predicted_weight as u64) / 1000;
723 if input_amounts <= fee {
724 updated_feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal) as u64;
725 fee = updated_feerate * (predicted_weight as u64) / 1000;
726 if input_amounts <= fee {
727 updated_feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background) as u64;
728 fee = updated_feerate * (predicted_weight as u64) / 1000;
729 if input_amounts <= fee {
730 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)",
734 log_warn!(logger, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
736 Some((fee, updated_feerate))
739 log_warn!(logger, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
741 Some((fee, updated_feerate))
744 Some((fee, updated_feerate))
748 /// Attempt to propose a bumping fee for a transaction from its spent output's values and predicted
749 /// weight. If feerates proposed by the fee-estimator have been increasing since last fee-bumping
750 /// attempt, use them. Otherwise, blindly bump the feerate by 25% of the previous feerate. We also
751 /// verify that those bumping heuristics respect BIP125 rules 3) and 4) and if required adjust
752 /// the new fee to meet the RBF policy requirement.
753 fn feerate_bump<F: Deref, L: Deref>(predicted_weight: usize, input_amounts: u64, previous_feerate: u64, fee_estimator: &F, logger: &L) -> Option<(u64, u64)>
754 where F::Target: FeeEstimator,
757 // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
758 let new_fee = if let Some((new_fee, _)) = compute_fee_from_spent_amounts(input_amounts, predicted_weight, fee_estimator, logger) {
759 let updated_feerate = new_fee / (predicted_weight as u64 * 1000);
760 if updated_feerate > previous_feerate {
763 // ...else just increase the previous feerate by 25% (because that's a nice number)
764 let new_fee = previous_feerate * (predicted_weight as u64) / 750;
765 if input_amounts <= new_fee {
766 log_trace!(logger, "Can't 25% bump new claiming tx, amount {} is too small", input_amounts);
772 log_trace!(logger, "Can't new-estimation bump new claiming tx, amount {} is too small", input_amounts);
776 let previous_fee = previous_feerate * (predicted_weight as u64) / 1000;
777 let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * (predicted_weight as u64) / 1000;
778 // BIP 125 Opt-in Full Replace-by-Fee Signaling
779 // * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
780 // * 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.
781 let new_fee = if new_fee < previous_fee + min_relay_fee {
782 new_fee + previous_fee + min_relay_fee - new_fee
786 Some((new_fee, new_fee * 1000 / (predicted_weight as u64)))
789 /// Deduce a new proposed fee from the claiming transaction output value.
790 /// If the new proposed fee is superior to the consumed outpoint's value, burn everything in miner's
791 /// fee to deter counterparties attacker.
792 pub(crate) fn compute_output_value<F: Deref, L: Deref>(predicted_weight: usize, input_amounts: u64, previous_feerate: u64, fee_estimator: &F, logger: &L) -> Option<(u64, u64)>
793 where F::Target: FeeEstimator,
796 // If old feerate is 0, first iteration of this claim, use normal fee calculation
797 if previous_feerate != 0 {
798 if let Some((new_fee, feerate)) = feerate_bump(predicted_weight, input_amounts, previous_feerate, fee_estimator, logger) {
799 // If new computed fee is superior at the whole claimable amount burn all in fees
800 if new_fee > input_amounts {
801 return Some((0, feerate));
803 return Some((input_amounts - new_fee, feerate));
807 if let Some((new_fee, feerate)) = compute_fee_from_spent_amounts(input_amounts, predicted_weight, fee_estimator, logger) {
808 return Some((input_amounts - new_fee, feerate));