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};
26 use ln::msgs::DecodeError;
27 use chain::chaininterface::{FeeEstimator, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT};
28 use chain::keysinterface::Sign;
29 use chain::onchaintx::OnchainTxHandler;
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 /// Height delay at which transactions are fee-bumped/rebroadcasted with a low priority.
53 const LOW_FREQUENCY_BUMP_INTERVAL: u32 = 15;
54 /// Height delay at which transactions are fee-bumped/rebroadcasted with a middle priority.
55 const MIDDLE_FREQUENCY_BUMP_INTERVAL: u32 = 3;
56 /// Height delay at which transactions are fee-bumped/rebroadcasted with a high priority.
57 const HIGH_FREQUENCY_BUMP_INTERVAL: u32 = 1;
59 /// A struct to describe a revoked output and corresponding information to generate a solving
60 /// witness spending a commitment `to_local` output or a second-stage HTLC transaction output.
62 /// CSV and pubkeys are used as part of a witnessScript redeeming a balance output, amount is used
63 /// as part of the signature hash and revocation secret to generate a satisfying witness.
64 #[derive(Clone, PartialEq)]
65 pub(crate) struct RevokedOutput {
66 per_commitment_point: PublicKey,
67 counterparty_delayed_payment_base_key: PublicKey,
68 counterparty_htlc_base_key: PublicKey,
69 per_commitment_key: SecretKey,
72 on_counterparty_tx_csv: u16,
76 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 {
79 counterparty_delayed_payment_base_key,
80 counterparty_htlc_base_key,
82 weight: WEIGHT_REVOKED_OUTPUT,
84 on_counterparty_tx_csv
89 impl_writeable_tlv_based!(RevokedOutput, {
90 (0, per_commitment_point),
91 (2, counterparty_delayed_payment_base_key),
92 (4, counterparty_htlc_base_key),
93 (6, per_commitment_key),
96 (12, on_counterparty_tx_csv),
99 /// A struct to describe a revoked offered output and corresponding information to generate a
102 /// HTLCOuputInCommitment (hash timelock, direction) and pubkeys are used to generate a suitable
105 /// CSV is used as part of a witnessScript redeeming a balance output, amount is used as part
106 /// of the signature hash and revocation secret to generate a satisfying witness.
107 #[derive(Clone, PartialEq)]
108 pub(crate) struct RevokedHTLCOutput {
109 per_commitment_point: PublicKey,
110 counterparty_delayed_payment_base_key: PublicKey,
111 counterparty_htlc_base_key: PublicKey,
112 per_commitment_key: SecretKey,
115 htlc: HTLCOutputInCommitment,
118 impl RevokedHTLCOutput {
119 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 {
120 let weight = if htlc.offered { WEIGHT_REVOKED_OFFERED_HTLC } else { WEIGHT_REVOKED_RECEIVED_HTLC };
122 per_commitment_point,
123 counterparty_delayed_payment_base_key,
124 counterparty_htlc_base_key,
133 impl_writeable_tlv_based!(RevokedHTLCOutput, {
134 (0, per_commitment_point),
135 (2, counterparty_delayed_payment_base_key),
136 (4, counterparty_htlc_base_key),
137 (6, per_commitment_key),
143 /// A struct to describe a HTLC output on a counterparty commitment transaction.
145 /// HTLCOutputInCommitment (hash, timelock, directon) and pubkeys are used to generate a suitable
148 /// The preimage is used as part of the witness.
149 #[derive(Clone, PartialEq)]
150 pub(crate) struct CounterpartyOfferedHTLCOutput {
151 per_commitment_point: PublicKey,
152 counterparty_delayed_payment_base_key: PublicKey,
153 counterparty_htlc_base_key: PublicKey,
154 preimage: PaymentPreimage,
155 htlc: HTLCOutputInCommitment
158 impl CounterpartyOfferedHTLCOutput {
159 pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: PublicKey, counterparty_htlc_base_key: PublicKey, preimage: PaymentPreimage, htlc: HTLCOutputInCommitment) -> Self {
160 CounterpartyOfferedHTLCOutput {
161 per_commitment_point,
162 counterparty_delayed_payment_base_key,
163 counterparty_htlc_base_key,
170 impl_writeable_tlv_based!(CounterpartyOfferedHTLCOutput, {
171 (0, per_commitment_point),
172 (2, counterparty_delayed_payment_base_key),
173 (4, counterparty_htlc_base_key),
178 /// A struct to describe a HTLC output on a counterparty commitment transaction.
180 /// HTLCOutputInCommitment (hash, timelock, directon) and pubkeys are used to generate a suitable
182 #[derive(Clone, PartialEq)]
183 pub(crate) struct CounterpartyReceivedHTLCOutput {
184 per_commitment_point: PublicKey,
185 counterparty_delayed_payment_base_key: PublicKey,
186 counterparty_htlc_base_key: PublicKey,
187 htlc: HTLCOutputInCommitment
190 impl CounterpartyReceivedHTLCOutput {
191 pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: PublicKey, counterparty_htlc_base_key: PublicKey, htlc: HTLCOutputInCommitment) -> Self {
192 CounterpartyReceivedHTLCOutput {
193 per_commitment_point,
194 counterparty_delayed_payment_base_key,
195 counterparty_htlc_base_key,
201 impl_writeable_tlv_based!(CounterpartyReceivedHTLCOutput, {
202 (0, per_commitment_point),
203 (2, counterparty_delayed_payment_base_key),
204 (4, counterparty_htlc_base_key),
208 /// A struct to describe a HTLC output on holder commitment transaction.
210 /// Either offered or received, the amount is always used as part of the bip143 sighash.
211 /// Preimage is only included as part of the witness in former case.
212 #[derive(Clone, PartialEq)]
213 pub(crate) struct HolderHTLCOutput {
214 preimage: Option<PaymentPreimage>,
218 impl HolderHTLCOutput {
219 pub(crate) fn build(preimage: Option<PaymentPreimage>, amount: u64) -> Self {
227 impl_writeable_tlv_based!(HolderHTLCOutput, {
233 /// A struct to describe the channel output on the funding transaction.
235 /// witnessScript is used as part of the witness redeeming the funding utxo.
236 #[derive(Clone, PartialEq)]
237 pub(crate) struct HolderFundingOutput {
238 funding_redeemscript: Script,
241 impl HolderFundingOutput {
242 pub(crate) fn build(funding_redeemscript: Script) -> Self {
243 HolderFundingOutput {
244 funding_redeemscript,
249 impl_writeable_tlv_based!(HolderFundingOutput, {
250 (0, funding_redeemscript),
253 /// A wrapper encapsulating all in-protocol differing outputs types.
255 /// The generic API offers access to an outputs common attributes or allow transformation such as
256 /// finalizing an input claiming the output.
257 #[derive(Clone, PartialEq)]
258 pub(crate) enum PackageSolvingData {
259 RevokedOutput(RevokedOutput),
260 RevokedHTLCOutput(RevokedHTLCOutput),
261 CounterpartyOfferedHTLCOutput(CounterpartyOfferedHTLCOutput),
262 CounterpartyReceivedHTLCOutput(CounterpartyReceivedHTLCOutput),
263 HolderHTLCOutput(HolderHTLCOutput),
264 HolderFundingOutput(HolderFundingOutput),
267 impl PackageSolvingData {
268 fn amount(&self) -> u64 {
269 let amt = match self {
270 PackageSolvingData::RevokedOutput(ref outp) => { outp.amount },
271 PackageSolvingData::RevokedHTLCOutput(ref outp) => { outp.amount },
272 PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => { outp.htlc.amount_msat / 1000 },
273 PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => { outp.htlc.amount_msat / 1000 },
274 // Note: Currently, amounts of holder outputs spending witnesses aren't used
275 // as we can't malleate spending package to increase their feerate. This
276 // should change with the remaining anchor output patchset.
277 PackageSolvingData::HolderHTLCOutput(..) => { 0 },
278 PackageSolvingData::HolderFundingOutput(..) => { 0 },
282 fn weight(&self) -> usize {
283 let weight = match self {
284 PackageSolvingData::RevokedOutput(ref outp) => { outp.weight as usize },
285 PackageSolvingData::RevokedHTLCOutput(ref outp) => { outp.weight as usize },
286 PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => { WEIGHT_OFFERED_HTLC as usize },
287 PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => { WEIGHT_RECEIVED_HTLC as usize },
288 // Note: Currently, weights of holder outputs spending witnesses aren't used
289 // as we can't malleate spending package to increase their feerate. This
290 // should change with the remaining anchor output patchset.
291 PackageSolvingData::HolderHTLCOutput(..) => { debug_assert!(false); 0 },
292 PackageSolvingData::HolderFundingOutput(..) => { debug_assert!(false); 0 },
296 fn is_compatible(&self, input: &PackageSolvingData) -> bool {
298 PackageSolvingData::RevokedOutput(..) => {
300 PackageSolvingData::RevokedHTLCOutput(..) => { true },
301 PackageSolvingData::RevokedOutput(..) => { true },
305 PackageSolvingData::RevokedHTLCOutput(..) => {
307 PackageSolvingData::RevokedOutput(..) => { true },
308 PackageSolvingData::RevokedHTLCOutput(..) => { true },
312 _ => { mem::discriminant(self) == mem::discriminant(&input) }
315 fn finalize_input<Signer: Sign>(&self, bumped_tx: &mut Transaction, i: usize, onchain_handler: &mut OnchainTxHandler<Signer>) -> bool {
317 PackageSolvingData::RevokedOutput(ref outp) => {
318 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) {
319 let witness_script = chan_utils::get_revokeable_redeemscript(&chan_keys.revocation_key, outp.on_counterparty_tx_csv, &chan_keys.broadcaster_delayed_payment_key);
320 //TODO: should we panic on signer failure ?
321 if let Ok(sig) = onchain_handler.signer.sign_justice_revoked_output(&bumped_tx, i, outp.amount, &outp.per_commitment_key, &onchain_handler.secp_ctx) {
322 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
323 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
324 bumped_tx.input[i].witness.push(vec!(1));
325 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
326 } else { return false; }
329 PackageSolvingData::RevokedHTLCOutput(ref outp) => {
330 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) {
331 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);
332 //TODO: should we panic on signer failure ?
333 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) {
334 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
335 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
336 bumped_tx.input[i].witness.push(chan_keys.revocation_key.clone().serialize().to_vec());
337 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
338 } else { return false; }
341 PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => {
342 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) {
343 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);
345 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) {
346 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
347 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
348 bumped_tx.input[i].witness.push(outp.preimage.0.to_vec());
349 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
353 PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => {
354 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) {
355 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);
357 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
358 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) {
359 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
360 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
361 // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
362 bumped_tx.input[i].witness.push(vec![]);
363 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
367 _ => { panic!("API Error!"); }
371 fn get_finalized_tx<Signer: Sign>(&self, outpoint: &BitcoinOutPoint, onchain_handler: &mut OnchainTxHandler<Signer>) -> Option<Transaction> {
373 PackageSolvingData::HolderHTLCOutput(ref outp) => { return onchain_handler.get_fully_signed_htlc_tx(outpoint, &outp.preimage); }
374 PackageSolvingData::HolderFundingOutput(ref outp) => { return Some(onchain_handler.get_fully_signed_holder_tx(&outp.funding_redeemscript)); }
375 _ => { panic!("API Error!"); }
380 impl Writeable for PackageSolvingData {
381 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
383 PackageSolvingData::RevokedOutput(ref revoked_outp) => {
385 revoked_outp.write(writer)?;
387 PackageSolvingData::RevokedHTLCOutput(ref revoked_outp) => {
389 revoked_outp.write(writer)?;
391 PackageSolvingData::CounterpartyOfferedHTLCOutput(ref counterparty_outp) => {
393 counterparty_outp.write(writer)?;
395 PackageSolvingData::CounterpartyReceivedHTLCOutput(ref counterparty_outp) => {
397 counterparty_outp.write(writer)?;
399 PackageSolvingData::HolderHTLCOutput(ref holder_outp) => {
401 holder_outp.write(writer)?;
403 PackageSolvingData::HolderFundingOutput(ref funding_outp) => {
405 funding_outp.write(writer)?;
412 impl Readable for PackageSolvingData {
413 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
414 let byte = <u8 as Readable>::read(reader)?;
415 let solving_data = match byte {
417 PackageSolvingData::RevokedOutput(Readable::read(reader)?)
420 PackageSolvingData::RevokedHTLCOutput(Readable::read(reader)?)
423 PackageSolvingData::CounterpartyOfferedHTLCOutput(Readable::read(reader)?)
426 PackageSolvingData::CounterpartyReceivedHTLCOutput(Readable::read(reader)?)
429 PackageSolvingData::HolderHTLCOutput(Readable::read(reader)?)
432 PackageSolvingData::HolderFundingOutput(Readable::read(reader)?)
434 _ => return Err(DecodeError::UnknownVersion)
440 /// A malleable package might be aggregated with other packages to save on fees.
441 /// A untractable package has been counter-signed and aggregable will break cached counterparty
443 #[derive(Clone, PartialEq)]
444 pub(crate) enum PackageMalleability {
449 /// A structure to describe a package content that is generated by ChannelMonitor and
450 /// used by OnchainTxHandler to generate and broadcast transactions settling onchain claims.
452 /// A package is defined as one or more transactions claiming onchain outputs in reaction
453 /// to confirmation of a channel transaction. Those packages might be aggregated to save on
454 /// fees, if satisfaction of outputs's witnessScript let's us do so.
456 /// As packages are time-sensitive, we fee-bump and rebroadcast them at scheduled intervals.
457 /// Failing to confirm a package translate as a loss of funds for the user.
458 #[derive(Clone, PartialEq)]
459 pub struct PackageTemplate {
460 // List of onchain outputs and solving data to generate satisfying witnesses.
461 inputs: Vec<(BitcoinOutPoint, PackageSolvingData)>,
462 // Packages are deemed as malleable if we have local knwoledge of at least one set of
463 // private keys yielding a satisfying witnesses. Malleability implies that we can aggregate
464 // packages among them to save on fees or rely on RBF to bump their feerates.
465 // Untractable packages have been counter-signed and thus imply that we can't aggregate
466 // them without breaking signatures. Fee-bumping strategy will also rely on CPFP.
467 malleability: PackageMalleability,
468 // Block height after which the earlier-output belonging to this package is mature for a
469 // competing claim by the counterparty. As our chain tip becomes nearer from the timelock,
470 // the fee-bumping frequency will increase. See `OnchainTxHandler::get_height_timer`.
471 soonest_conf_deadline: u32,
472 // Determines if this package can be aggregated.
473 // Timelocked outputs belonging to the same transaction might have differing
474 // satisfying heights. Picking up the later height among the output set would be a valid
475 // aggregable strategy but it comes with at least 2 trade-offs :
476 // * earlier-output fund are going to take longer to come back
477 // * CLTV delta backing up a corresponding HTLC on an upstream channel could be swallowed
478 // by the requirement of the later-output part of the set
479 // For now, we mark such timelocked outputs as non-aggregable, though we might introduce
480 // smarter aggregable strategy in the future.
482 // Cache of package feerate committed at previous (re)broadcast. If bumping resources
483 // (either claimed output value or external utxo), it will keep increasing until holder
484 // or counterparty successful claim.
485 feerate_previous: u64,
486 // Cache of next height at which fee-bumping and rebroadcast will be attempted. In
487 // the future, we might abstract it to an observed mempool fluctuation.
488 height_timer: Option<u32>,
489 // Confirmation height of the claimed outputs set transaction. In case of reorg reaching
490 // it, we wipe out and forget the package.
491 height_original: u32,
494 impl PackageTemplate {
495 pub(crate) fn is_malleable(&self) -> bool {
496 self.malleability == PackageMalleability::Malleable
498 pub(crate) fn timelock(&self) -> u32 {
499 self.soonest_conf_deadline
501 pub(crate) fn aggregable(&self) -> bool {
504 pub(crate) fn set_feerate(&mut self, new_feerate: u64) {
505 self.feerate_previous = new_feerate;
507 pub(crate) fn timer(&self) -> Option<u32> {
508 if let Some(ref timer) = self.height_timer {
513 pub(crate) fn set_timer(&mut self, new_timer: Option<u32>) {
514 self.height_timer = new_timer;
516 pub(crate) fn outpoints(&self) -> Vec<&BitcoinOutPoint> {
517 self.inputs.iter().map(|(o, _)| o).collect()
519 pub(crate) fn split_package(&mut self, split_outp: &BitcoinOutPoint) -> Option<PackageTemplate> {
520 match self.malleability {
521 PackageMalleability::Malleable => {
522 let mut split_package = None;
523 let timelock = self.soonest_conf_deadline;
524 let aggregable = self.aggregable;
525 let feerate_previous = self.feerate_previous;
526 let height_timer = self.height_timer;
527 let height_original = self.height_original;
528 self.inputs.retain(|outp| {
529 if *split_outp == outp.0 {
530 split_package = Some(PackageTemplate {
531 inputs: vec![(outp.0, outp.1.clone())],
532 malleability: PackageMalleability::Malleable,
533 soonest_conf_deadline: timelock,
543 return split_package;
546 // Note, we may try to split on remote transaction for
547 // which we don't have a competing one (HTLC-Success before
548 // timelock expiration). This explain we don't panic!
549 // We should refactor OnchainTxHandler::block_connected to
550 // only test equality on competing claims.
555 pub(crate) fn merge_package(&mut self, mut merge_from: PackageTemplate) {
556 assert_eq!(self.height_original, merge_from.height_original);
557 if self.malleability == PackageMalleability::Untractable || merge_from.malleability == PackageMalleability::Untractable {
558 panic!("Merging template on untractable packages");
560 if !self.aggregable || !merge_from.aggregable {
561 panic!("Merging non aggregatable packages");
563 if let Some((_, lead_input)) = self.inputs.first() {
564 for (_, v) in merge_from.inputs.iter() {
565 if !lead_input.is_compatible(v) { panic!("Merging outputs from differing types !"); }
567 } else { panic!("Merging template on an empty package"); }
568 for (k, v) in merge_from.inputs.drain(..) {
569 self.inputs.push((k, v));
571 //TODO: verify coverage and sanity?
572 if self.soonest_conf_deadline > merge_from.soonest_conf_deadline {
573 self.soonest_conf_deadline = merge_from.soonest_conf_deadline;
575 if self.feerate_previous > merge_from.feerate_previous {
576 self.feerate_previous = merge_from.feerate_previous;
578 self.height_timer = cmp::min(self.height_timer, merge_from.height_timer);
580 pub(crate) fn package_amount(&self) -> u64 {
582 for (_, outp) in self.inputs.iter() {
583 amounts += outp.amount();
587 pub(crate) fn package_weight(&self, destination_script: &Script) -> usize {
588 let mut inputs_weight = 0;
589 let mut witnesses_weight = 2; // count segwit flags
590 for (_, outp) in self.inputs.iter() {
591 // previous_out_point: 36 bytes ; var_int: 1 byte ; sequence: 4 bytes
592 inputs_weight += 41 * WITNESS_SCALE_FACTOR;
593 witnesses_weight += outp.weight();
595 // version: 4 bytes ; count_tx_in: 1 byte ; count_tx_out: 1 byte ; lock_time: 4 bytes
596 let transaction_weight = 10 * WITNESS_SCALE_FACTOR;
597 // value: 8 bytes ; var_int: 1 byte ; pk_script: `destination_script.len()`
598 let output_weight = (8 + 1 + destination_script.len()) * WITNESS_SCALE_FACTOR;
599 inputs_weight + witnesses_weight + transaction_weight + output_weight
601 pub(crate) fn finalize_package<L: Deref, Signer: Sign>(&self, onchain_handler: &mut OnchainTxHandler<Signer>, value: u64, destination_script: Script, logger: &L) -> Option<Transaction>
602 where L::Target: Logger,
604 match self.malleability {
605 PackageMalleability::Malleable => {
606 let mut bumped_tx = Transaction {
611 script_pubkey: destination_script,
615 for (outpoint, _) in self.inputs.iter() {
616 bumped_tx.input.push(TxIn {
617 previous_output: *outpoint,
618 script_sig: Script::new(),
619 sequence: 0xfffffffd,
623 for (i, (outpoint, out)) in self.inputs.iter().enumerate() {
624 log_trace!(logger, "Adding claiming input for outpoint {}:{}", outpoint.txid, outpoint.vout);
625 if !out.finalize_input(&mut bumped_tx, i, onchain_handler) { return None; }
627 log_trace!(logger, "Finalized transaction {} ready to broadcast", bumped_tx.txid());
628 return Some(bumped_tx);
630 PackageMalleability::Untractable => {
631 if let Some((outpoint, outp)) = self.inputs.first() {
632 if let Some(final_tx) = outp.get_finalized_tx(outpoint, onchain_handler) {
633 log_trace!(logger, "Adding claiming input for outpoint {}:{}", outpoint.txid, outpoint.vout);
634 log_trace!(logger, "Finalized transaction {} ready to broadcast", final_tx.txid());
635 return Some(final_tx);
638 } else { panic!("API Error: Package must not be inputs empty"); }
642 /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
643 /// 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
644 /// height that once reached we should generate a new bumped "version" of the claim tx to be sure that we safely claim outputs before
645 /// that our counterparty can do so. If timelock expires soon, height timer is going to be scaled down in consequence to increase
646 /// frequency of the bump and so increase our bets of success.
647 pub(crate) fn get_height_timer(&self, current_height: u32) -> u32 {
648 if self.soonest_conf_deadline <= current_height + MIDDLE_FREQUENCY_BUMP_INTERVAL {
649 return current_height + HIGH_FREQUENCY_BUMP_INTERVAL
650 } else if self.soonest_conf_deadline - current_height <= LOW_FREQUENCY_BUMP_INTERVAL {
651 return current_height + MIDDLE_FREQUENCY_BUMP_INTERVAL
653 current_height + LOW_FREQUENCY_BUMP_INTERVAL
655 /// Returns value in satoshis to be included as package outgoing output amount and feerate with which package finalization should be done.
656 pub(crate) fn compute_package_output<F: Deref, L: Deref>(&self, predicted_weight: usize, input_amounts: u64, fee_estimator: &F, logger: &L) -> Option<(u64, u64)>
657 where F::Target: FeeEstimator,
660 // If old feerate is 0, first iteration of this claim, use normal fee calculation
661 if self.feerate_previous != 0 {
662 if let Some((new_fee, feerate)) = feerate_bump(predicted_weight, input_amounts, self.feerate_previous, fee_estimator, logger) {
663 // If new computed fee is superior at the whole claimable amount burn all in fees
664 if new_fee > input_amounts {
665 return Some((0, feerate));
667 return Some((input_amounts - new_fee, feerate));
671 if let Some((new_fee, feerate)) = compute_fee_from_spent_amounts(input_amounts, predicted_weight, fee_estimator, logger) {
672 return Some((input_amounts - new_fee, feerate));
677 pub (crate) fn build_package(txid: Txid, vout: u32, input_solving_data: PackageSolvingData, soonest_conf_deadline: u32, aggregable: bool, height_original: u32) -> Self {
678 let malleability = match input_solving_data {
679 PackageSolvingData::RevokedOutput(..) => { PackageMalleability::Malleable },
680 PackageSolvingData::RevokedHTLCOutput(..) => { PackageMalleability::Malleable },
681 PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => { PackageMalleability::Malleable },
682 PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => { PackageMalleability::Malleable },
683 PackageSolvingData::HolderHTLCOutput(..) => { PackageMalleability::Untractable },
684 PackageSolvingData::HolderFundingOutput(..) => { PackageMalleability::Untractable },
686 let mut inputs = Vec::with_capacity(1);
687 inputs.push((BitcoinOutPoint { txid, vout }, input_solving_data));
691 soonest_conf_deadline,
700 impl Writeable for PackageTemplate {
701 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
702 writer.write_all(&byte_utils::be64_to_array(self.inputs.len() as u64))?;
703 for (ref outpoint, ref rev_outp) in self.inputs.iter() {
704 outpoint.write(writer)?;
705 rev_outp.write(writer)?;
707 write_tlv_fields!(writer, {
708 (0, self.soonest_conf_deadline),
709 (2, self.feerate_previous),
710 (4, self.height_original),
711 }, { (6, self.height_timer) });
716 impl Readable for PackageTemplate {
717 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
718 let inputs_count = <u64 as Readable>::read(reader)?;
719 let mut inputs: Vec<(BitcoinOutPoint, PackageSolvingData)> = Vec::with_capacity(cmp::min(inputs_count as usize, MAX_ALLOC_SIZE / 128));
720 for _ in 0..inputs_count {
721 let outpoint = Readable::read(reader)?;
722 let rev_outp = Readable::read(reader)?;
723 inputs.push((outpoint, rev_outp));
725 let (malleability, aggregable) = if let Some((_, lead_input)) = inputs.first() {
727 PackageSolvingData::RevokedOutput(..) => { (PackageMalleability::Malleable, true) },
728 PackageSolvingData::RevokedHTLCOutput(..) => { (PackageMalleability::Malleable, true) },
729 PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => { (PackageMalleability::Malleable, true) },
730 PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => { (PackageMalleability::Malleable, false) },
731 PackageSolvingData::HolderHTLCOutput(..) => { (PackageMalleability::Untractable, false) },
732 PackageSolvingData::HolderFundingOutput(..) => { (PackageMalleability::Untractable, false) },
734 } else { return Err(DecodeError::InvalidValue); };
735 let mut soonest_conf_deadline = 0;
736 let mut feerate_previous = 0;
737 let mut height_timer = None;
738 let mut height_original = 0;
739 read_tlv_fields!(reader, {
740 (0, soonest_conf_deadline),
741 (2, feerate_previous),
743 }, { (6, height_timer) });
747 soonest_conf_deadline,
756 /// Attempt to propose a bumping fee for a transaction from its spent output's values and predicted
757 /// weight. We start with the highest priority feerate returned by the node's fee estimator then
758 /// fall-back to lower priorities until we have enough value available to suck from.
760 /// If the proposed fee is less than the available spent output's values, we return the proposed
761 /// fee and the corresponding updated feerate. If the proposed fee is equal or more than the
762 /// available spent output's values, we return nothing
763 fn compute_fee_from_spent_amounts<F: Deref, L: Deref>(input_amounts: u64, predicted_weight: usize, fee_estimator: &F, logger: &L) -> Option<(u64, u64)>
764 where F::Target: FeeEstimator,
767 let mut updated_feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) as u64;
768 let mut fee = updated_feerate * (predicted_weight as u64) / 1000;
769 if input_amounts <= fee {
770 updated_feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal) as u64;
771 fee = updated_feerate * (predicted_weight as u64) / 1000;
772 if input_amounts <= fee {
773 updated_feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background) as u64;
774 fee = updated_feerate * (predicted_weight as u64) / 1000;
775 if input_amounts <= fee {
776 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)",
780 log_warn!(logger, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
782 Some((fee, updated_feerate))
785 log_warn!(logger, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
787 Some((fee, updated_feerate))
790 Some((fee, updated_feerate))
794 /// Attempt to propose a bumping fee for a transaction from its spent output's values and predicted
795 /// weight. If feerates proposed by the fee-estimator have been increasing since last fee-bumping
796 /// attempt, use them. Otherwise, blindly bump the feerate by 25% of the previous feerate. We also
797 /// verify that those bumping heuristics respect BIP125 rules 3) and 4) and if required adjust
798 /// the new fee to meet the RBF policy requirement.
799 fn feerate_bump<F: Deref, L: Deref>(predicted_weight: usize, input_amounts: u64, previous_feerate: u64, fee_estimator: &F, logger: &L) -> Option<(u64, u64)>
800 where F::Target: FeeEstimator,
803 // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
804 let new_fee = if let Some((new_fee, _)) = compute_fee_from_spent_amounts(input_amounts, predicted_weight, fee_estimator, logger) {
805 let updated_feerate = new_fee / (predicted_weight as u64 * 1000);
806 if updated_feerate > previous_feerate {
809 // ...else just increase the previous feerate by 25% (because that's a nice number)
810 let new_fee = previous_feerate * (predicted_weight as u64) / 750;
811 if input_amounts <= new_fee {
812 log_trace!(logger, "Can't 25% bump new claiming tx, amount {} is too small", input_amounts);
818 log_trace!(logger, "Can't new-estimation bump new claiming tx, amount {} is too small", input_amounts);
822 let previous_fee = previous_feerate * (predicted_weight as u64) / 1000;
823 let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * (predicted_weight as u64) / 1000;
824 // BIP 125 Opt-in Full Replace-by-Fee Signaling
825 // * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
826 // * 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.
827 let new_fee = if new_fee < previous_fee + min_relay_fee {
828 new_fee + previous_fee + min_relay_fee - new_fee
832 Some((new_fee, new_fee * 1000 / (predicted_weight as u64)))
837 use chain::package::{CounterpartyReceivedHTLCOutput, HolderHTLCOutput, PackageTemplate, PackageSolvingData, RevokedOutput, WEIGHT_REVOKED_OUTPUT};
839 use ln::chan_utils::HTLCOutputInCommitment;
840 use ln::{PaymentPreimage, PaymentHash};
842 use bitcoin::blockdata::constants::WITNESS_SCALE_FACTOR;
843 use bitcoin::blockdata::script::Script;
844 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
846 use bitcoin::hashes::hex::FromHex;
848 use bitcoin::secp256k1::key::{PublicKey,SecretKey};
849 use bitcoin::secp256k1::Secp256k1;
851 macro_rules! dumb_revk_output {
852 ($secp_ctx: expr) => {
854 let dumb_scalar = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
855 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
856 PackageSolvingData::RevokedOutput(RevokedOutput::build(dumb_point, dumb_point, dumb_point, dumb_scalar, 0, 0))
861 macro_rules! dumb_counterparty_output {
862 ($secp_ctx: expr, $amt: expr) => {
864 let dumb_scalar = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
865 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
866 let hash = PaymentHash([1; 32]);
867 let htlc = HTLCOutputInCommitment { offered: true, amount_msat: $amt, cltv_expiry: 0, payment_hash: hash, transaction_output_index: None };
868 PackageSolvingData::CounterpartyReceivedHTLCOutput(CounterpartyReceivedHTLCOutput::build(dumb_point, dumb_point, dumb_point, htlc))
873 macro_rules! dumb_htlc_output {
876 let preimage = PaymentPreimage([2;32]);
877 PackageSolvingData::HolderHTLCOutput(HolderHTLCOutput::build(Some(preimage), 0))
884 fn test_package_differing_heights() {
885 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
886 let secp_ctx = Secp256k1::new();
887 let revk_outp = dumb_revk_output!(secp_ctx);
889 let mut package_one_hundred = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, true, 100);
890 let package_two_hundred = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, true, 200);
891 package_one_hundred.merge_package(package_two_hundred);
896 fn test_package_untractable_merge_to() {
897 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
898 let secp_ctx = Secp256k1::new();
899 let revk_outp = dumb_revk_output!(secp_ctx);
900 let htlc_outp = dumb_htlc_output!();
902 let mut untractable_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, true, 100);
903 let malleable_package = PackageTemplate::build_package(txid, 1, htlc_outp.clone(), 1000, true, 100);
904 untractable_package.merge_package(malleable_package);
909 fn test_package_untractable_merge_from() {
910 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
911 let secp_ctx = Secp256k1::new();
912 let htlc_outp = dumb_htlc_output!();
913 let revk_outp = dumb_revk_output!(secp_ctx);
915 let mut malleable_package = PackageTemplate::build_package(txid, 0, htlc_outp.clone(), 1000, true, 100);
916 let untractable_package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, true, 100);
917 malleable_package.merge_package(untractable_package);
922 fn test_package_noaggregation_to() {
923 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
924 let secp_ctx = Secp256k1::new();
925 let revk_outp = dumb_revk_output!(secp_ctx);
927 let mut noaggregation_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, false, 100);
928 let aggregation_package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, true, 100);
929 noaggregation_package.merge_package(aggregation_package);
934 fn test_package_noaggregation_from() {
935 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
936 let secp_ctx = Secp256k1::new();
937 let revk_outp = dumb_revk_output!(secp_ctx);
939 let mut aggregation_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, true, 100);
940 let noaggregation_package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, false, 100);
941 aggregation_package.merge_package(noaggregation_package);
946 fn test_package_empty() {
947 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
948 let secp_ctx = Secp256k1::new();
949 let revk_outp = dumb_revk_output!(secp_ctx);
951 let mut empty_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, true, 100);
952 empty_package.inputs = vec![];
953 let package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, true, 100);
954 empty_package.merge_package(package);
959 fn test_package_differing_categories() {
960 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
961 let secp_ctx = Secp256k1::new();
962 let revk_outp = dumb_revk_output!(secp_ctx);
963 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 0);
965 let mut revoked_package = PackageTemplate::build_package(txid, 0, revk_outp, 1000, true, 100);
966 let counterparty_package = PackageTemplate::build_package(txid, 1, counterparty_outp, 1000, true, 100);
967 revoked_package.merge_package(counterparty_package);
971 fn test_package_split_malleable() {
972 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
973 let secp_ctx = Secp256k1::new();
974 let revk_outp_one = dumb_revk_output!(secp_ctx);
975 let revk_outp_two = dumb_revk_output!(secp_ctx);
976 let revk_outp_three = dumb_revk_output!(secp_ctx);
978 let mut package_one = PackageTemplate::build_package(txid, 0, revk_outp_one, 1000, true, 100);
979 let package_two = PackageTemplate::build_package(txid, 1, revk_outp_two, 1000, true, 100);
980 let package_three = PackageTemplate::build_package(txid, 2, revk_outp_three, 1000, true, 100);
982 package_one.merge_package(package_two);
983 package_one.merge_package(package_three);
984 assert_eq!(package_one.outpoints().len(), 3);
986 if let Some(split_package) = package_one.split_package(&BitcoinOutPoint { txid, vout: 1 }) {
987 // Packages attributes should be identical
988 assert!(split_package.is_malleable());
989 assert_eq!(split_package.soonest_conf_deadline, package_one.soonest_conf_deadline);
990 assert_eq!(split_package.aggregable, package_one.aggregable);
991 assert_eq!(split_package.feerate_previous, package_one.feerate_previous);
992 assert_eq!(split_package.height_timer, package_one.height_timer);
993 assert_eq!(split_package.height_original, package_one.height_original);
995 assert_eq!(package_one.outpoints().len(), 2);
999 fn test_package_split_untractable() {
1000 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1001 let htlc_outp_one = dumb_htlc_output!();
1003 let mut package_one = PackageTemplate::build_package(txid, 0, htlc_outp_one, 1000, true, 100);
1004 let ret_split = package_one.split_package(&BitcoinOutPoint { txid, vout: 0});
1005 assert!(ret_split.is_none());
1009 fn test_package_timer() {
1010 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1011 let secp_ctx = Secp256k1::new();
1012 let revk_outp = dumb_revk_output!(secp_ctx);
1014 let mut package = PackageTemplate::build_package(txid, 0, revk_outp, 1000, true, 100);
1015 let timer_none = package.timer();
1016 assert!(timer_none.is_none());
1017 package.set_timer(Some(100));
1018 if let Some(timer_some) = package.timer() {
1019 assert_eq!(timer_some, 100);
1024 fn test_package_amounts() {
1025 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1026 let secp_ctx = Secp256k1::new();
1027 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 1_000_000);
1029 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, true, 100);
1030 assert_eq!(package.package_amount(), 1000);
1034 fn test_package_weight() {
1035 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1036 let secp_ctx = Secp256k1::new();
1037 let revk_outp = dumb_revk_output!(secp_ctx);
1039 let package = PackageTemplate::build_package(txid, 0, revk_outp, 0, true, 100);
1040 // (nVersion (4) + nLocktime (4) + count_tx_in (1) + prevout (36) + sequence (4) + script_length (1) + count_tx_out (1) + value (8) + var_int (1)) * WITNESS_SCALE_FACTOR
1041 // + witness marker (2) + WEIGHT_REVOKED_OUTPUT
1042 assert_eq!(package.package_weight(&Script::new()), (4 + 4 + 1 + 36 + 4 + 1 + 1 + 8 + 1) * WITNESS_SCALE_FACTOR + 2 + WEIGHT_REVOKED_OUTPUT as usize);