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, EcdsaSighashType};
16 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
17 use bitcoin::blockdata::script::Script;
19 use bitcoin::hash_types::Txid;
21 use bitcoin::secp256k1::{SecretKey,PublicKey};
23 use crate::ln::PaymentPreimage;
24 use crate::ln::chan_utils::{TxCreationKeys, HTLCOutputInCommitment};
25 use crate::ln::chan_utils;
26 use crate::ln::msgs::DecodeError;
27 use crate::chain::chaininterface::{FeeEstimator, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT};
28 use crate::sign::WriteableEcdsaChannelSigner;
30 use crate::chain::onchaintx::ExternalHTLCClaim;
31 use crate::chain::onchaintx::OnchainTxHandler;
32 use crate::util::logger::Logger;
33 use crate::util::ser::{Readable, Writer, Writeable, RequiredWrapper};
36 use crate::prelude::*;
39 use core::convert::TryInto;
42 use bitcoin::{PackedLockTime, Sequence, Witness};
43 use crate::ln::features::ChannelTypeFeatures;
45 use super::chaininterface::LowerBoundedFeeEstimator;
47 const MAX_ALLOC_SIZE: usize = 64*1024;
50 pub(crate) fn weight_revoked_offered_htlc(channel_type_features: &ChannelTypeFeatures) -> u64 {
51 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
52 const WEIGHT_REVOKED_OFFERED_HTLC: u64 = 1 + 1 + 73 + 1 + 33 + 1 + 133;
53 const WEIGHT_REVOKED_OFFERED_HTLC_ANCHORS: u64 = WEIGHT_REVOKED_OFFERED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
54 if channel_type_features.supports_anchors_zero_fee_htlc_tx() { WEIGHT_REVOKED_OFFERED_HTLC_ANCHORS } else { WEIGHT_REVOKED_OFFERED_HTLC }
57 pub(crate) fn weight_revoked_received_htlc(channel_type_features: &ChannelTypeFeatures) -> u64 {
58 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
59 const WEIGHT_REVOKED_RECEIVED_HTLC: u64 = 1 + 1 + 73 + 1 + 33 + 1 + 139;
60 const WEIGHT_REVOKED_RECEIVED_HTLC_ANCHORS: u64 = WEIGHT_REVOKED_RECEIVED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
61 if channel_type_features.supports_anchors_zero_fee_htlc_tx() { WEIGHT_REVOKED_RECEIVED_HTLC_ANCHORS } else { WEIGHT_REVOKED_RECEIVED_HTLC }
64 pub(crate) fn weight_offered_htlc(channel_type_features: &ChannelTypeFeatures) -> u64 {
65 // number_of_witness_elements + sig_length + counterpartyhtlc_sig + preimage_length + preimage + witness_script_length + witness_script
66 const WEIGHT_OFFERED_HTLC: u64 = 1 + 1 + 73 + 1 + 32 + 1 + 133;
67 const WEIGHT_OFFERED_HTLC_ANCHORS: u64 = WEIGHT_OFFERED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
68 if channel_type_features.supports_anchors_zero_fee_htlc_tx() { WEIGHT_OFFERED_HTLC_ANCHORS } else { WEIGHT_OFFERED_HTLC }
71 pub(crate) fn weight_received_htlc(channel_type_features: &ChannelTypeFeatures) -> u64 {
72 // number_of_witness_elements + sig_length + counterpartyhtlc_sig + empty_vec_length + empty_vec + witness_script_length + witness_script
73 const WEIGHT_RECEIVED_HTLC: u64 = 1 + 1 + 73 + 1 + 1 + 1 + 139;
74 const WEIGHT_RECEIVED_HTLC_ANCHORS: u64 = WEIGHT_RECEIVED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
75 if channel_type_features.supports_anchors_zero_fee_htlc_tx() { WEIGHT_RECEIVED_HTLC_ANCHORS } else { WEIGHT_RECEIVED_HTLC }
78 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
79 pub(crate) const WEIGHT_REVOKED_OUTPUT: u64 = 1 + 1 + 73 + 1 + 1 + 1 + 77;
81 /// Height delay at which transactions are fee-bumped/rebroadcasted with a low priority.
82 const LOW_FREQUENCY_BUMP_INTERVAL: u32 = 15;
83 /// Height delay at which transactions are fee-bumped/rebroadcasted with a middle priority.
84 const MIDDLE_FREQUENCY_BUMP_INTERVAL: u32 = 3;
85 /// Height delay at which transactions are fee-bumped/rebroadcasted with a high priority.
86 const HIGH_FREQUENCY_BUMP_INTERVAL: u32 = 1;
88 /// A struct to describe a revoked output and corresponding information to generate a solving
89 /// witness spending a commitment `to_local` output or a second-stage HTLC transaction output.
91 /// CSV and pubkeys are used as part of a witnessScript redeeming a balance output, amount is used
92 /// as part of the signature hash and revocation secret to generate a satisfying witness.
93 #[derive(Clone, PartialEq, Eq)]
94 pub(crate) struct RevokedOutput {
95 per_commitment_point: PublicKey,
96 counterparty_delayed_payment_base_key: PublicKey,
97 counterparty_htlc_base_key: PublicKey,
98 per_commitment_key: SecretKey,
101 on_counterparty_tx_csv: u16,
102 is_counterparty_balance_on_anchors: Option<()>,
106 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, is_counterparty_balance_on_anchors: bool) -> Self {
108 per_commitment_point,
109 counterparty_delayed_payment_base_key,
110 counterparty_htlc_base_key,
112 weight: WEIGHT_REVOKED_OUTPUT,
114 on_counterparty_tx_csv,
115 is_counterparty_balance_on_anchors: if is_counterparty_balance_on_anchors { Some(()) } else { None }
120 impl_writeable_tlv_based!(RevokedOutput, {
121 (0, per_commitment_point, required),
122 (2, counterparty_delayed_payment_base_key, required),
123 (4, counterparty_htlc_base_key, required),
124 (6, per_commitment_key, required),
125 (8, weight, required),
126 (10, amount, required),
127 (12, on_counterparty_tx_csv, required),
128 (14, is_counterparty_balance_on_anchors, option)
131 /// A struct to describe a revoked offered output and corresponding information to generate a
134 /// HTLCOuputInCommitment (hash timelock, direction) and pubkeys are used to generate a suitable
137 /// CSV is used as part of a witnessScript redeeming a balance output, amount is used as part
138 /// of the signature hash and revocation secret to generate a satisfying witness.
139 #[derive(Clone, PartialEq, Eq)]
140 pub(crate) struct RevokedHTLCOutput {
141 per_commitment_point: PublicKey,
142 counterparty_delayed_payment_base_key: PublicKey,
143 counterparty_htlc_base_key: PublicKey,
144 per_commitment_key: SecretKey,
147 htlc: HTLCOutputInCommitment,
150 impl RevokedHTLCOutput {
151 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, channel_type_features: &ChannelTypeFeatures) -> Self {
152 let weight = if htlc.offered { weight_revoked_offered_htlc(channel_type_features) } else { weight_revoked_received_htlc(channel_type_features) };
154 per_commitment_point,
155 counterparty_delayed_payment_base_key,
156 counterparty_htlc_base_key,
165 impl_writeable_tlv_based!(RevokedHTLCOutput, {
166 (0, per_commitment_point, required),
167 (2, counterparty_delayed_payment_base_key, required),
168 (4, counterparty_htlc_base_key, required),
169 (6, per_commitment_key, required),
170 (8, weight, required),
171 (10, amount, required),
172 (12, htlc, required),
175 /// A struct to describe a HTLC output on a counterparty commitment transaction.
177 /// HTLCOutputInCommitment (hash, timelock, directon) and pubkeys are used to generate a suitable
180 /// The preimage is used as part of the witness.
182 /// Note that on upgrades, some features of existing outputs may be missed.
183 #[derive(Clone, PartialEq, Eq)]
184 pub(crate) struct CounterpartyOfferedHTLCOutput {
185 per_commitment_point: PublicKey,
186 counterparty_delayed_payment_base_key: PublicKey,
187 counterparty_htlc_base_key: PublicKey,
188 preimage: PaymentPreimage,
189 htlc: HTLCOutputInCommitment,
190 channel_type_features: ChannelTypeFeatures,
193 impl CounterpartyOfferedHTLCOutput {
194 pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: PublicKey, counterparty_htlc_base_key: PublicKey, preimage: PaymentPreimage, htlc: HTLCOutputInCommitment, channel_type_features: ChannelTypeFeatures) -> Self {
195 CounterpartyOfferedHTLCOutput {
196 per_commitment_point,
197 counterparty_delayed_payment_base_key,
198 counterparty_htlc_base_key,
201 channel_type_features,
206 impl Writeable for CounterpartyOfferedHTLCOutput {
207 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
208 let legacy_deserialization_prevention_marker = chan_utils::legacy_deserialization_prevention_marker_for_channel_type_features(&self.channel_type_features);
209 write_tlv_fields!(writer, {
210 (0, self.per_commitment_point, required),
211 (2, self.counterparty_delayed_payment_base_key, required),
212 (4, self.counterparty_htlc_base_key, required),
213 (6, self.preimage, required),
214 (8, self.htlc, required),
215 (10, legacy_deserialization_prevention_marker, option),
216 (11, self.channel_type_features, required),
222 impl Readable for CounterpartyOfferedHTLCOutput {
223 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
224 let mut per_commitment_point = RequiredWrapper(None);
225 let mut counterparty_delayed_payment_base_key = RequiredWrapper(None);
226 let mut counterparty_htlc_base_key = RequiredWrapper(None);
227 let mut preimage = RequiredWrapper(None);
228 let mut htlc = RequiredWrapper(None);
229 let mut legacy_deserialization_prevention_marker: Option<()> = None;
230 let mut channel_type_features = None;
232 read_tlv_fields!(reader, {
233 (0, per_commitment_point, required),
234 (2, counterparty_delayed_payment_base_key, required),
235 (4, counterparty_htlc_base_key, required),
236 (6, preimage, required),
238 (10, legacy_deserialization_prevention_marker, option),
239 (11, channel_type_features, option),
243 per_commitment_point: per_commitment_point.0.unwrap(),
244 counterparty_delayed_payment_base_key: counterparty_delayed_payment_base_key.0.unwrap(),
245 counterparty_htlc_base_key: counterparty_htlc_base_key.0.unwrap(),
246 preimage: preimage.0.unwrap(),
247 htlc: htlc.0.unwrap(),
248 channel_type_features: channel_type_features.unwrap_or(ChannelTypeFeatures::only_static_remote_key())
253 /// A struct to describe a HTLC output on a counterparty commitment transaction.
255 /// HTLCOutputInCommitment (hash, timelock, directon) and pubkeys are used to generate a suitable
258 /// Note that on upgrades, some features of existing outputs may be missed.
259 #[derive(Clone, PartialEq, Eq)]
260 pub(crate) struct CounterpartyReceivedHTLCOutput {
261 per_commitment_point: PublicKey,
262 counterparty_delayed_payment_base_key: PublicKey,
263 counterparty_htlc_base_key: PublicKey,
264 htlc: HTLCOutputInCommitment,
265 channel_type_features: ChannelTypeFeatures,
268 impl CounterpartyReceivedHTLCOutput {
269 pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: PublicKey, counterparty_htlc_base_key: PublicKey, htlc: HTLCOutputInCommitment, channel_type_features: ChannelTypeFeatures) -> Self {
270 CounterpartyReceivedHTLCOutput {
271 per_commitment_point,
272 counterparty_delayed_payment_base_key,
273 counterparty_htlc_base_key,
275 channel_type_features
280 impl Writeable for CounterpartyReceivedHTLCOutput {
281 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
282 let legacy_deserialization_prevention_marker = chan_utils::legacy_deserialization_prevention_marker_for_channel_type_features(&self.channel_type_features);
283 write_tlv_fields!(writer, {
284 (0, self.per_commitment_point, required),
285 (2, self.counterparty_delayed_payment_base_key, required),
286 (4, self.counterparty_htlc_base_key, required),
287 (6, self.htlc, required),
288 (8, legacy_deserialization_prevention_marker, option),
289 (9, self.channel_type_features, required),
295 impl Readable for CounterpartyReceivedHTLCOutput {
296 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
297 let mut per_commitment_point = RequiredWrapper(None);
298 let mut counterparty_delayed_payment_base_key = RequiredWrapper(None);
299 let mut counterparty_htlc_base_key = RequiredWrapper(None);
300 let mut htlc = RequiredWrapper(None);
301 let mut legacy_deserialization_prevention_marker: Option<()> = None;
302 let mut channel_type_features = None;
304 read_tlv_fields!(reader, {
305 (0, per_commitment_point, required),
306 (2, counterparty_delayed_payment_base_key, required),
307 (4, counterparty_htlc_base_key, required),
309 (8, legacy_deserialization_prevention_marker, option),
310 (9, channel_type_features, option),
314 per_commitment_point: per_commitment_point.0.unwrap(),
315 counterparty_delayed_payment_base_key: counterparty_delayed_payment_base_key.0.unwrap(),
316 counterparty_htlc_base_key: counterparty_htlc_base_key.0.unwrap(),
317 htlc: htlc.0.unwrap(),
318 channel_type_features: channel_type_features.unwrap_or(ChannelTypeFeatures::only_static_remote_key())
323 /// A struct to describe a HTLC output on holder commitment transaction.
325 /// Either offered or received, the amount is always used as part of the bip143 sighash.
326 /// Preimage is only included as part of the witness in former case.
328 /// Note that on upgrades, some features of existing outputs may be missed.
329 #[derive(Clone, PartialEq, Eq)]
330 pub(crate) struct HolderHTLCOutput {
331 preimage: Option<PaymentPreimage>,
333 /// Defaults to 0 for HTLC-Success transactions, which have no expiry
335 channel_type_features: ChannelTypeFeatures,
338 impl HolderHTLCOutput {
339 pub(crate) fn build_offered(amount_msat: u64, cltv_expiry: u32, channel_type_features: ChannelTypeFeatures) -> Self {
344 channel_type_features,
348 pub(crate) fn build_accepted(preimage: PaymentPreimage, amount_msat: u64, channel_type_features: ChannelTypeFeatures) -> Self {
350 preimage: Some(preimage),
353 channel_type_features,
358 impl Writeable for HolderHTLCOutput {
359 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
360 let legacy_deserialization_prevention_marker = chan_utils::legacy_deserialization_prevention_marker_for_channel_type_features(&self.channel_type_features);
361 write_tlv_fields!(writer, {
362 (0, self.amount_msat, required),
363 (2, self.cltv_expiry, required),
364 (4, self.preimage, option),
365 (6, legacy_deserialization_prevention_marker, option),
366 (7, self.channel_type_features, required),
372 impl Readable for HolderHTLCOutput {
373 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
374 let mut amount_msat = RequiredWrapper(None);
375 let mut cltv_expiry = RequiredWrapper(None);
376 let mut preimage = None;
377 let mut legacy_deserialization_prevention_marker: Option<()> = None;
378 let mut channel_type_features = None;
380 read_tlv_fields!(reader, {
381 (0, amount_msat, required),
382 (2, cltv_expiry, required),
383 (4, preimage, option),
384 (6, legacy_deserialization_prevention_marker, option),
385 (7, channel_type_features, option),
389 amount_msat: amount_msat.0.unwrap(),
390 cltv_expiry: cltv_expiry.0.unwrap(),
392 channel_type_features: channel_type_features.unwrap_or(ChannelTypeFeatures::only_static_remote_key())
397 /// A struct to describe the channel output on the funding transaction.
399 /// witnessScript is used as part of the witness redeeming the funding utxo.
401 /// Note that on upgrades, some features of existing outputs may be missed.
402 #[derive(Clone, PartialEq, Eq)]
403 pub(crate) struct HolderFundingOutput {
404 funding_redeemscript: Script,
405 funding_amount: Option<u64>,
406 channel_type_features: ChannelTypeFeatures,
410 impl HolderFundingOutput {
411 pub(crate) fn build(funding_redeemscript: Script, funding_amount: u64, channel_type_features: ChannelTypeFeatures) -> Self {
412 HolderFundingOutput {
413 funding_redeemscript,
414 funding_amount: Some(funding_amount),
415 channel_type_features,
420 impl Writeable for HolderFundingOutput {
421 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
422 let legacy_deserialization_prevention_marker = chan_utils::legacy_deserialization_prevention_marker_for_channel_type_features(&self.channel_type_features);
423 write_tlv_fields!(writer, {
424 (0, self.funding_redeemscript, required),
425 (1, self.channel_type_features, required),
426 (2, legacy_deserialization_prevention_marker, option),
427 (3, self.funding_amount, option),
433 impl Readable for HolderFundingOutput {
434 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
435 let mut funding_redeemscript = RequiredWrapper(None);
436 let mut legacy_deserialization_prevention_marker: Option<()> = None;
437 let mut channel_type_features = None;
438 let mut funding_amount = None;
440 read_tlv_fields!(reader, {
441 (0, funding_redeemscript, required),
442 (1, channel_type_features, option),
443 (2, legacy_deserialization_prevention_marker, option),
444 (3, funding_amount, option)
448 funding_redeemscript: funding_redeemscript.0.unwrap(),
449 channel_type_features: channel_type_features.unwrap_or(ChannelTypeFeatures::only_static_remote_key()),
455 /// A wrapper encapsulating all in-protocol differing outputs types.
457 /// The generic API offers access to an outputs common attributes or allow transformation such as
458 /// finalizing an input claiming the output.
459 #[derive(Clone, PartialEq, Eq)]
460 pub(crate) enum PackageSolvingData {
461 RevokedOutput(RevokedOutput),
462 RevokedHTLCOutput(RevokedHTLCOutput),
463 CounterpartyOfferedHTLCOutput(CounterpartyOfferedHTLCOutput),
464 CounterpartyReceivedHTLCOutput(CounterpartyReceivedHTLCOutput),
465 HolderHTLCOutput(HolderHTLCOutput),
466 HolderFundingOutput(HolderFundingOutput),
469 impl PackageSolvingData {
470 fn amount(&self) -> u64 {
471 let amt = match self {
472 PackageSolvingData::RevokedOutput(ref outp) => outp.amount,
473 PackageSolvingData::RevokedHTLCOutput(ref outp) => outp.amount,
474 PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => outp.htlc.amount_msat / 1000,
475 PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => outp.htlc.amount_msat / 1000,
476 PackageSolvingData::HolderHTLCOutput(ref outp) => {
477 debug_assert!(outp.channel_type_features.supports_anchors_zero_fee_htlc_tx());
478 outp.amount_msat / 1000
480 PackageSolvingData::HolderFundingOutput(ref outp) => {
481 debug_assert!(outp.channel_type_features.supports_anchors_zero_fee_htlc_tx());
482 outp.funding_amount.unwrap()
487 fn weight(&self) -> usize {
489 PackageSolvingData::RevokedOutput(ref outp) => outp.weight as usize,
490 PackageSolvingData::RevokedHTLCOutput(ref outp) => outp.weight as usize,
491 PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => weight_offered_htlc(&outp.channel_type_features) as usize,
492 PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => weight_received_htlc(&outp.channel_type_features) as usize,
493 PackageSolvingData::HolderHTLCOutput(ref outp) => {
494 debug_assert!(outp.channel_type_features.supports_anchors_zero_fee_htlc_tx());
495 if outp.preimage.is_none() {
496 weight_offered_htlc(&outp.channel_type_features) as usize
498 weight_received_htlc(&outp.channel_type_features) as usize
501 // Since HolderFundingOutput maps to an untractable package that is already signed, its
502 // weight can be determined from the transaction itself.
503 PackageSolvingData::HolderFundingOutput(..) => unreachable!(),
506 fn is_compatible(&self, input: &PackageSolvingData) -> bool {
508 PackageSolvingData::RevokedOutput(..) => {
510 PackageSolvingData::RevokedHTLCOutput(..) => { true },
511 PackageSolvingData::RevokedOutput(..) => { true },
515 PackageSolvingData::RevokedHTLCOutput(..) => {
517 PackageSolvingData::RevokedOutput(..) => { true },
518 PackageSolvingData::RevokedHTLCOutput(..) => { true },
522 _ => { mem::discriminant(self) == mem::discriminant(&input) }
525 fn finalize_input<Signer: WriteableEcdsaChannelSigner>(&self, bumped_tx: &mut Transaction, i: usize, onchain_handler: &mut OnchainTxHandler<Signer>) -> bool {
527 PackageSolvingData::RevokedOutput(ref outp) => {
528 let 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);
529 let witness_script = chan_utils::get_revokeable_redeemscript(&chan_keys.revocation_key, outp.on_counterparty_tx_csv, &chan_keys.broadcaster_delayed_payment_key);
530 //TODO: should we panic on signer failure ?
531 if let Ok(sig) = onchain_handler.signer.sign_justice_revoked_output(&bumped_tx, i, outp.amount, &outp.per_commitment_key, &onchain_handler.secp_ctx) {
532 let mut ser_sig = sig.serialize_der().to_vec();
533 ser_sig.push(EcdsaSighashType::All as u8);
534 bumped_tx.input[i].witness.push(ser_sig);
535 bumped_tx.input[i].witness.push(vec!(1));
536 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
537 } else { return false; }
539 PackageSolvingData::RevokedHTLCOutput(ref outp) => {
540 let 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);
541 let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, &onchain_handler.channel_type_features(), &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
542 //TODO: should we panic on signer failure ?
543 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) {
544 let mut ser_sig = sig.serialize_der().to_vec();
545 ser_sig.push(EcdsaSighashType::All as u8);
546 bumped_tx.input[i].witness.push(ser_sig);
547 bumped_tx.input[i].witness.push(chan_keys.revocation_key.clone().serialize().to_vec());
548 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
549 } else { return false; }
551 PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => {
552 let 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);
553 let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, &onchain_handler.channel_type_features(), &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
555 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) {
556 let mut ser_sig = sig.serialize_der().to_vec();
557 ser_sig.push(EcdsaSighashType::All as u8);
558 bumped_tx.input[i].witness.push(ser_sig);
559 bumped_tx.input[i].witness.push(outp.preimage.0.to_vec());
560 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
563 PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => {
564 let 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);
565 let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, &onchain_handler.channel_type_features(), &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
567 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) {
568 let mut ser_sig = sig.serialize_der().to_vec();
569 ser_sig.push(EcdsaSighashType::All as u8);
570 bumped_tx.input[i].witness.push(ser_sig);
571 // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
572 bumped_tx.input[i].witness.push(vec![]);
573 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
576 _ => { panic!("API Error!"); }
580 fn get_finalized_tx<Signer: WriteableEcdsaChannelSigner>(&self, outpoint: &BitcoinOutPoint, onchain_handler: &mut OnchainTxHandler<Signer>) -> Option<Transaction> {
582 PackageSolvingData::HolderHTLCOutput(ref outp) => {
583 debug_assert!(!outp.channel_type_features.supports_anchors_zero_fee_htlc_tx());
584 return onchain_handler.get_fully_signed_htlc_tx(outpoint, &outp.preimage);
586 PackageSolvingData::HolderFundingOutput(ref outp) => {
587 return Some(onchain_handler.get_fully_signed_holder_tx(&outp.funding_redeemscript));
589 _ => { panic!("API Error!"); }
592 fn absolute_tx_timelock(&self, current_height: u32) -> u32 {
593 // We use `current_height` as our default locktime to discourage fee sniping and because
594 // transactions with it always propagate.
595 let absolute_timelock = match self {
596 PackageSolvingData::RevokedOutput(_) => current_height,
597 PackageSolvingData::RevokedHTLCOutput(_) => current_height,
598 PackageSolvingData::CounterpartyOfferedHTLCOutput(_) => current_height,
599 PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => cmp::max(outp.htlc.cltv_expiry, current_height),
600 // HTLC timeout/success transactions rely on a fixed timelock due to the counterparty's
602 PackageSolvingData::HolderHTLCOutput(ref outp) => {
603 if outp.preimage.is_some() {
604 debug_assert_eq!(outp.cltv_expiry, 0);
608 PackageSolvingData::HolderFundingOutput(_) => current_height,
613 fn map_output_type_flags(&self) -> (PackageMalleability, bool) {
614 // Post-anchor, aggregation of outputs of different types is unsafe. See https://github.com/lightning/bolts/pull/803.
615 let (malleability, aggregable) = match self {
616 PackageSolvingData::RevokedOutput(RevokedOutput { is_counterparty_balance_on_anchors: Some(()), .. }) => { (PackageMalleability::Malleable, false) },
617 PackageSolvingData::RevokedOutput(RevokedOutput { is_counterparty_balance_on_anchors: None, .. }) => { (PackageMalleability::Malleable, true) },
618 PackageSolvingData::RevokedHTLCOutput(..) => { (PackageMalleability::Malleable, true) },
619 PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => { (PackageMalleability::Malleable, true) },
620 PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => { (PackageMalleability::Malleable, false) },
621 PackageSolvingData::HolderHTLCOutput(ref outp) => if outp.channel_type_features.supports_anchors_zero_fee_htlc_tx() {
622 (PackageMalleability::Malleable, outp.preimage.is_some())
624 (PackageMalleability::Untractable, false)
626 PackageSolvingData::HolderFundingOutput(..) => { (PackageMalleability::Untractable, false) },
628 (malleability, aggregable)
632 impl_writeable_tlv_based_enum!(PackageSolvingData, ;
634 (1, RevokedHTLCOutput),
635 (2, CounterpartyOfferedHTLCOutput),
636 (3, CounterpartyReceivedHTLCOutput),
637 (4, HolderHTLCOutput),
638 (5, HolderFundingOutput),
641 /// A malleable package might be aggregated with other packages to save on fees.
642 /// A untractable package has been counter-signed and aggregable will break cached counterparty signatures.
643 #[derive(Clone, PartialEq, Eq)]
644 pub(crate) enum PackageMalleability {
649 /// A structure to describe a package content that is generated by ChannelMonitor and
650 /// used by OnchainTxHandler to generate and broadcast transactions settling onchain claims.
652 /// A package is defined as one or more transactions claiming onchain outputs in reaction
653 /// to confirmation of a channel transaction. Those packages might be aggregated to save on
654 /// fees, if satisfaction of outputs's witnessScript let's us do so.
656 /// As packages are time-sensitive, we fee-bump and rebroadcast them at scheduled intervals.
657 /// Failing to confirm a package translate as a loss of funds for the user.
658 #[derive(Clone, PartialEq, Eq)]
659 pub struct PackageTemplate {
660 // List of onchain outputs and solving data to generate satisfying witnesses.
661 inputs: Vec<(BitcoinOutPoint, PackageSolvingData)>,
662 // Packages are deemed as malleable if we have local knwoledge of at least one set of
663 // private keys yielding a satisfying witnesses. Malleability implies that we can aggregate
664 // packages among them to save on fees or rely on RBF to bump their feerates.
665 // Untractable packages have been counter-signed and thus imply that we can't aggregate
666 // them without breaking signatures. Fee-bumping strategy will also rely on CPFP.
667 malleability: PackageMalleability,
668 // Block height after which the earlier-output belonging to this package is mature for a
669 // competing claim by the counterparty. As our chain tip becomes nearer from the timelock,
670 // the fee-bumping frequency will increase. See `OnchainTxHandler::get_height_timer`.
671 soonest_conf_deadline: u32,
672 // Determines if this package can be aggregated.
673 // Timelocked outputs belonging to the same transaction might have differing
674 // satisfying heights. Picking up the later height among the output set would be a valid
675 // aggregable strategy but it comes with at least 2 trade-offs :
676 // * earlier-output fund are going to take longer to come back
677 // * CLTV delta backing up a corresponding HTLC on an upstream channel could be swallowed
678 // by the requirement of the later-output part of the set
679 // For now, we mark such timelocked outputs as non-aggregable, though we might introduce
680 // smarter aggregable strategy in the future.
682 // Cache of package feerate committed at previous (re)broadcast. If bumping resources
683 // (either claimed output value or external utxo), it will keep increasing until holder
684 // or counterparty successful claim.
685 feerate_previous: u64,
686 // Cache of next height at which fee-bumping and rebroadcast will be attempted. In
687 // the future, we might abstract it to an observed mempool fluctuation.
689 // Confirmation height of the claimed outputs set transaction. In case of reorg reaching
690 // it, we wipe out and forget the package.
691 height_original: u32,
694 impl PackageTemplate {
695 pub(crate) fn is_malleable(&self) -> bool {
696 self.malleability == PackageMalleability::Malleable
698 pub(crate) fn timelock(&self) -> u32 {
699 self.soonest_conf_deadline
701 pub(crate) fn aggregable(&self) -> bool {
704 pub(crate) fn previous_feerate(&self) -> u64 {
705 self.feerate_previous
707 pub(crate) fn set_feerate(&mut self, new_feerate: u64) {
708 self.feerate_previous = new_feerate;
710 pub(crate) fn timer(&self) -> u32 {
713 pub(crate) fn set_timer(&mut self, new_timer: u32) {
714 self.height_timer = new_timer;
716 pub(crate) fn outpoints(&self) -> Vec<&BitcoinOutPoint> {
717 self.inputs.iter().map(|(o, _)| o).collect()
719 pub(crate) fn inputs(&self) -> impl ExactSizeIterator<Item = &PackageSolvingData> {
720 self.inputs.iter().map(|(_, i)| i)
722 pub(crate) fn split_package(&mut self, split_outp: &BitcoinOutPoint) -> Option<PackageTemplate> {
723 match self.malleability {
724 PackageMalleability::Malleable => {
725 let mut split_package = None;
726 let timelock = self.soonest_conf_deadline;
727 let aggregable = self.aggregable;
728 let feerate_previous = self.feerate_previous;
729 let height_timer = self.height_timer;
730 let height_original = self.height_original;
731 self.inputs.retain(|outp| {
732 if *split_outp == outp.0 {
733 split_package = Some(PackageTemplate {
734 inputs: vec![(outp.0, outp.1.clone())],
735 malleability: PackageMalleability::Malleable,
736 soonest_conf_deadline: timelock,
746 return split_package;
749 // Note, we may try to split on remote transaction for
750 // which we don't have a competing one (HTLC-Success before
751 // timelock expiration). This explain we don't panic!
752 // We should refactor OnchainTxHandler::block_connected to
753 // only test equality on competing claims.
758 pub(crate) fn merge_package(&mut self, mut merge_from: PackageTemplate) {
759 assert_eq!(self.height_original, merge_from.height_original);
760 if self.malleability == PackageMalleability::Untractable || merge_from.malleability == PackageMalleability::Untractable {
761 panic!("Merging template on untractable packages");
763 if !self.aggregable || !merge_from.aggregable {
764 panic!("Merging non aggregatable packages");
766 if let Some((_, lead_input)) = self.inputs.first() {
767 for (_, v) in merge_from.inputs.iter() {
768 if !lead_input.is_compatible(v) { panic!("Merging outputs from differing types !"); }
770 } else { panic!("Merging template on an empty package"); }
771 for (k, v) in merge_from.inputs.drain(..) {
772 self.inputs.push((k, v));
774 //TODO: verify coverage and sanity?
775 if self.soonest_conf_deadline > merge_from.soonest_conf_deadline {
776 self.soonest_conf_deadline = merge_from.soonest_conf_deadline;
778 if self.feerate_previous > merge_from.feerate_previous {
779 self.feerate_previous = merge_from.feerate_previous;
781 self.height_timer = cmp::min(self.height_timer, merge_from.height_timer);
783 /// Gets the amount of all outptus being spent by this package, only valid for malleable
785 pub(crate) fn package_amount(&self) -> u64 {
787 for (_, outp) in self.inputs.iter() {
788 amounts += outp.amount();
792 pub(crate) fn package_locktime(&self, current_height: u32) -> u32 {
793 let locktime = self.inputs.iter().map(|(_, outp)| outp.absolute_tx_timelock(current_height))
794 .max().expect("There must always be at least one output to spend in a PackageTemplate");
796 // If we ever try to aggregate a `HolderHTLCOutput`s with another output type, we'll likely
797 // end up with an incorrect transaction locktime since the counterparty has included it in
798 // its HTLC signature. This should never happen unless we decide to aggregate outputs across
799 // different channel commitments.
800 #[cfg(debug_assertions)] {
801 if self.inputs.iter().any(|(_, outp)|
802 if let PackageSolvingData::HolderHTLCOutput(outp) = outp {
803 outp.preimage.is_some()
808 debug_assert_eq!(locktime, 0);
810 for timeout_htlc_expiry in self.inputs.iter().filter_map(|(_, outp)|
811 if let PackageSolvingData::HolderHTLCOutput(outp) = outp {
812 if outp.preimage.is_none() {
813 Some(outp.cltv_expiry)
817 debug_assert_eq!(locktime, timeout_htlc_expiry);
823 pub(crate) fn package_weight(&self, destination_script: &Script) -> usize {
824 let mut inputs_weight = 0;
825 let mut witnesses_weight = 2; // count segwit flags
826 for (_, outp) in self.inputs.iter() {
827 // previous_out_point: 36 bytes ; var_int: 1 byte ; sequence: 4 bytes
828 inputs_weight += 41 * WITNESS_SCALE_FACTOR;
829 witnesses_weight += outp.weight();
831 // version: 4 bytes ; count_tx_in: 1 byte ; count_tx_out: 1 byte ; lock_time: 4 bytes
832 let transaction_weight = 10 * WITNESS_SCALE_FACTOR;
833 // value: 8 bytes ; var_int: 1 byte ; pk_script: `destination_script.len()`
834 let output_weight = (8 + 1 + destination_script.len()) * WITNESS_SCALE_FACTOR;
835 inputs_weight + witnesses_weight + transaction_weight + output_weight
838 pub(crate) fn construct_malleable_package_with_external_funding<Signer: WriteableEcdsaChannelSigner>(
839 &self, onchain_handler: &mut OnchainTxHandler<Signer>,
840 ) -> Option<Vec<ExternalHTLCClaim>> {
841 debug_assert!(self.requires_external_funding());
842 let mut htlcs: Option<Vec<ExternalHTLCClaim>> = None;
843 for (previous_output, input) in &self.inputs {
845 PackageSolvingData::HolderHTLCOutput(ref outp) => {
846 debug_assert!(outp.channel_type_features.supports_anchors_zero_fee_htlc_tx());
847 onchain_handler.generate_external_htlc_claim(&previous_output, &outp.preimage).map(|htlc| {
848 htlcs.get_or_insert_with(|| Vec::with_capacity(self.inputs.len())).push(htlc);
851 _ => debug_assert!(false, "Expected HolderHTLCOutputs to not be aggregated with other input types"),
856 pub(crate) fn finalize_malleable_package<L: Deref, Signer: WriteableEcdsaChannelSigner>(
857 &self, current_height: u32, onchain_handler: &mut OnchainTxHandler<Signer>, value: u64,
858 destination_script: Script, logger: &L
859 ) -> Option<Transaction> where L::Target: Logger {
860 debug_assert!(self.is_malleable());
861 let mut bumped_tx = Transaction {
863 lock_time: PackedLockTime(self.package_locktime(current_height)),
866 script_pubkey: destination_script,
870 for (outpoint, _) in self.inputs.iter() {
871 bumped_tx.input.push(TxIn {
872 previous_output: *outpoint,
873 script_sig: Script::new(),
874 sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
875 witness: Witness::new(),
878 for (i, (outpoint, out)) in self.inputs.iter().enumerate() {
879 log_debug!(logger, "Adding claiming input for outpoint {}:{}", outpoint.txid, outpoint.vout);
880 if !out.finalize_input(&mut bumped_tx, i, onchain_handler) { return None; }
882 log_debug!(logger, "Finalized transaction {} ready to broadcast", bumped_tx.txid());
885 pub(crate) fn finalize_untractable_package<L: Deref, Signer: WriteableEcdsaChannelSigner>(
886 &self, onchain_handler: &mut OnchainTxHandler<Signer>, logger: &L,
887 ) -> Option<Transaction> where L::Target: Logger {
888 debug_assert!(!self.is_malleable());
889 if let Some((outpoint, outp)) = self.inputs.first() {
890 if let Some(final_tx) = outp.get_finalized_tx(outpoint, onchain_handler) {
891 log_debug!(logger, "Adding claiming input for outpoint {}:{}", outpoint.txid, outpoint.vout);
892 log_debug!(logger, "Finalized transaction {} ready to broadcast", final_tx.txid());
893 return Some(final_tx);
896 } else { panic!("API Error: Package must not be inputs empty"); }
898 /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
899 /// 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
900 /// height that once reached we should generate a new bumped "version" of the claim tx to be sure that we safely claim outputs before
901 /// that our counterparty can do so. If timelock expires soon, height timer is going to be scaled down in consequence to increase
902 /// frequency of the bump and so increase our bets of success.
903 pub(crate) fn get_height_timer(&self, current_height: u32) -> u32 {
904 if self.soonest_conf_deadline <= current_height + MIDDLE_FREQUENCY_BUMP_INTERVAL {
905 return current_height + HIGH_FREQUENCY_BUMP_INTERVAL
906 } else if self.soonest_conf_deadline - current_height <= LOW_FREQUENCY_BUMP_INTERVAL {
907 return current_height + MIDDLE_FREQUENCY_BUMP_INTERVAL
909 current_height + LOW_FREQUENCY_BUMP_INTERVAL
912 /// Returns value in satoshis to be included as package outgoing output amount and feerate
913 /// which was used to generate the value. Will not return less than `dust_limit_sats` for the
915 pub(crate) fn compute_package_output<F: Deref, L: Deref>(
916 &self, predicted_weight: usize, dust_limit_sats: u64, force_feerate_bump: bool,
917 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L,
918 ) -> Option<(u64, u64)>
920 F::Target: FeeEstimator,
923 debug_assert!(self.malleability == PackageMalleability::Malleable, "The package output is fixed for non-malleable packages");
924 let input_amounts = self.package_amount();
925 assert!(dust_limit_sats as i64 > 0, "Output script must be broadcastable/have a 'real' dust limit.");
926 // If old feerate is 0, first iteration of this claim, use normal fee calculation
927 if self.feerate_previous != 0 {
928 if let Some((new_fee, feerate)) = feerate_bump(
929 predicted_weight, input_amounts, self.feerate_previous, force_feerate_bump,
930 fee_estimator, logger,
932 return Some((cmp::max(input_amounts as i64 - new_fee as i64, dust_limit_sats as i64) as u64, feerate));
935 if let Some((new_fee, feerate)) = compute_fee_from_spent_amounts(input_amounts, predicted_weight, fee_estimator, logger) {
936 return Some((cmp::max(input_amounts as i64 - new_fee as i64, dust_limit_sats as i64) as u64, feerate));
943 /// Computes a feerate based on the given confirmation target. If a previous feerate was used,
944 /// the new feerate is below it, and `force_feerate_bump` is set, we'll use a 25% increase of
945 /// the previous feerate instead of the new feerate.
946 pub(crate) fn compute_package_feerate<F: Deref>(
947 &self, fee_estimator: &LowerBoundedFeeEstimator<F>, conf_target: ConfirmationTarget,
948 force_feerate_bump: bool,
949 ) -> u32 where F::Target: FeeEstimator {
950 let feerate_estimate = fee_estimator.bounded_sat_per_1000_weight(conf_target);
951 if self.feerate_previous != 0 {
952 // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
953 if feerate_estimate as u64 > self.feerate_previous {
955 } else if !force_feerate_bump {
956 self.feerate_previous.try_into().unwrap_or(u32::max_value())
958 // ...else just increase the previous feerate by 25% (because that's a nice number)
959 (self.feerate_previous + (self.feerate_previous / 4)).try_into().unwrap_or(u32::max_value())
966 /// Determines whether a package contains an input which must have additional external inputs
967 /// attached to help the spending transaction reach confirmation.
968 pub(crate) fn requires_external_funding(&self) -> bool {
969 self.inputs.iter().find(|input| match input.1 {
970 PackageSolvingData::HolderFundingOutput(ref outp) => outp.channel_type_features.supports_anchors_zero_fee_htlc_tx(),
971 PackageSolvingData::HolderHTLCOutput(ref outp) => outp.channel_type_features.supports_anchors_zero_fee_htlc_tx(),
976 pub (crate) fn build_package(txid: Txid, vout: u32, input_solving_data: PackageSolvingData, soonest_conf_deadline: u32, height_original: u32) -> Self {
977 let (malleability, aggregable) = PackageSolvingData::map_output_type_flags(&input_solving_data);
978 let mut inputs = Vec::with_capacity(1);
979 inputs.push((BitcoinOutPoint { txid, vout }, input_solving_data));
983 soonest_conf_deadline,
986 height_timer: height_original,
992 impl Writeable for PackageTemplate {
993 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
994 writer.write_all(&(self.inputs.len() as u64).to_be_bytes())?;
995 for (ref outpoint, ref rev_outp) in self.inputs.iter() {
996 outpoint.write(writer)?;
997 rev_outp.write(writer)?;
999 write_tlv_fields!(writer, {
1000 (0, self.soonest_conf_deadline, required),
1001 (2, self.feerate_previous, required),
1002 (4, self.height_original, required),
1003 (6, self.height_timer, required)
1009 impl Readable for PackageTemplate {
1010 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
1011 let inputs_count = <u64 as Readable>::read(reader)?;
1012 let mut inputs: Vec<(BitcoinOutPoint, PackageSolvingData)> = Vec::with_capacity(cmp::min(inputs_count as usize, MAX_ALLOC_SIZE / 128));
1013 for _ in 0..inputs_count {
1014 let outpoint = Readable::read(reader)?;
1015 let rev_outp = Readable::read(reader)?;
1016 inputs.push((outpoint, rev_outp));
1018 let (malleability, aggregable) = if let Some((_, lead_input)) = inputs.first() {
1019 PackageSolvingData::map_output_type_flags(&lead_input)
1020 } else { return Err(DecodeError::InvalidValue); };
1021 let mut soonest_conf_deadline = 0;
1022 let mut feerate_previous = 0;
1023 let mut height_timer = None;
1024 let mut height_original = 0;
1025 read_tlv_fields!(reader, {
1026 (0, soonest_conf_deadline, required),
1027 (2, feerate_previous, required),
1028 (4, height_original, required),
1029 (6, height_timer, option),
1031 if height_timer.is_none() {
1032 height_timer = Some(height_original);
1034 Ok(PackageTemplate {
1037 soonest_conf_deadline,
1040 height_timer: height_timer.unwrap(),
1046 /// Attempt to propose a bumping fee for a transaction from its spent output's values and predicted
1047 /// weight. We start with the highest priority feerate returned by the node's fee estimator then
1048 /// fall-back to lower priorities until we have enough value available to suck from.
1050 /// If the proposed fee is less than the available spent output's values, we return the proposed
1051 /// fee and the corresponding updated feerate. If the proposed fee is equal or more than the
1052 /// available spent output's values, we return nothing
1053 fn compute_fee_from_spent_amounts<F: Deref, L: Deref>(input_amounts: u64, predicted_weight: usize, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L) -> Option<(u64, u64)>
1054 where F::Target: FeeEstimator,
1057 let mut updated_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::HighPriority) as u64;
1058 let mut fee = updated_feerate * (predicted_weight as u64) / 1000;
1059 if input_amounts <= fee {
1060 updated_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal) as u64;
1061 fee = updated_feerate * (predicted_weight as u64) / 1000;
1062 if input_amounts <= fee {
1063 updated_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Background) as u64;
1064 fee = updated_feerate * (predicted_weight as u64) / 1000;
1065 if input_amounts <= fee {
1066 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)",
1067 fee, input_amounts);
1070 log_warn!(logger, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
1072 Some((fee, updated_feerate))
1075 log_warn!(logger, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
1077 Some((fee, updated_feerate))
1080 Some((fee, updated_feerate))
1084 /// Attempt to propose a bumping fee for a transaction from its spent output's values and predicted
1085 /// weight. If feerates proposed by the fee-estimator have been increasing since last fee-bumping
1086 /// attempt, use them. If `force_feerate_bump` is set, we bump the feerate by 25% of the previous
1087 /// feerate, or just use the previous feerate otherwise. If a feerate bump did happen, we also
1088 /// verify that those bumping heuristics respect BIP125 rules 3) and 4) and if required adjust the
1089 /// new fee to meet the RBF policy requirement.
1090 fn feerate_bump<F: Deref, L: Deref>(
1091 predicted_weight: usize, input_amounts: u64, previous_feerate: u64, force_feerate_bump: bool,
1092 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L,
1093 ) -> Option<(u64, u64)>
1095 F::Target: FeeEstimator,
1098 // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
1099 let (new_fee, new_feerate) = if let Some((new_fee, new_feerate)) = compute_fee_from_spent_amounts(input_amounts, predicted_weight, fee_estimator, logger) {
1100 if new_feerate > previous_feerate {
1101 (new_fee, new_feerate)
1102 } else if !force_feerate_bump {
1103 let previous_fee = previous_feerate * (predicted_weight as u64) / 1000;
1104 (previous_fee, previous_feerate)
1106 // ...else just increase the previous feerate by 25% (because that's a nice number)
1107 let bumped_feerate = previous_feerate + (previous_feerate / 4);
1108 let bumped_fee = bumped_feerate * (predicted_weight as u64) / 1000;
1109 if input_amounts <= bumped_fee {
1110 log_warn!(logger, "Can't 25% bump new claiming tx, amount {} is too small", input_amounts);
1113 (bumped_fee, bumped_feerate)
1116 log_warn!(logger, "Can't new-estimation bump new claiming tx, amount {} is too small", input_amounts);
1120 // Our feerates should never decrease. If it hasn't changed though, we just need to
1121 // rebroadcast/re-sign the previous claim.
1122 debug_assert!(new_feerate >= previous_feerate);
1123 if new_feerate == previous_feerate {
1124 return Some((new_fee, new_feerate));
1127 let previous_fee = previous_feerate * (predicted_weight as u64) / 1000;
1128 let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * (predicted_weight as u64) / 1000;
1129 // BIP 125 Opt-in Full Replace-by-Fee Signaling
1130 // * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
1131 // * 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.
1132 let new_fee = if new_fee < previous_fee + min_relay_fee {
1133 new_fee + previous_fee + min_relay_fee - new_fee
1137 Some((new_fee, new_fee * 1000 / (predicted_weight as u64)))
1142 use crate::chain::package::{CounterpartyOfferedHTLCOutput, CounterpartyReceivedHTLCOutput, HolderHTLCOutput, PackageTemplate, PackageSolvingData, RevokedOutput, WEIGHT_REVOKED_OUTPUT, weight_offered_htlc, weight_received_htlc};
1143 use crate::chain::Txid;
1144 use crate::ln::chan_utils::HTLCOutputInCommitment;
1145 use crate::ln::{PaymentPreimage, PaymentHash};
1147 use bitcoin::blockdata::constants::WITNESS_SCALE_FACTOR;
1148 use bitcoin::blockdata::script::Script;
1149 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
1151 use bitcoin::hashes::hex::FromHex;
1153 use bitcoin::secp256k1::{PublicKey,SecretKey};
1154 use bitcoin::secp256k1::Secp256k1;
1155 use crate::ln::features::ChannelTypeFeatures;
1157 macro_rules! dumb_revk_output {
1158 ($secp_ctx: expr, $is_counterparty_balance_on_anchors: expr) => {
1160 let dumb_scalar = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
1161 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
1162 PackageSolvingData::RevokedOutput(RevokedOutput::build(dumb_point, dumb_point, dumb_point, dumb_scalar, 0, 0, $is_counterparty_balance_on_anchors))
1167 macro_rules! dumb_counterparty_output {
1168 ($secp_ctx: expr, $amt: expr, $opt_anchors: expr) => {
1170 let dumb_scalar = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
1171 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
1172 let hash = PaymentHash([1; 32]);
1173 let htlc = HTLCOutputInCommitment { offered: true, amount_msat: $amt, cltv_expiry: 0, payment_hash: hash, transaction_output_index: None };
1174 PackageSolvingData::CounterpartyReceivedHTLCOutput(CounterpartyReceivedHTLCOutput::build(dumb_point, dumb_point, dumb_point, htlc, $opt_anchors))
1179 macro_rules! dumb_counterparty_offered_output {
1180 ($secp_ctx: expr, $amt: expr, $opt_anchors: expr) => {
1182 let dumb_scalar = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
1183 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
1184 let hash = PaymentHash([1; 32]);
1185 let preimage = PaymentPreimage([2;32]);
1186 let htlc = HTLCOutputInCommitment { offered: false, amount_msat: $amt, cltv_expiry: 1000, payment_hash: hash, transaction_output_index: None };
1187 PackageSolvingData::CounterpartyOfferedHTLCOutput(CounterpartyOfferedHTLCOutput::build(dumb_point, dumb_point, dumb_point, preimage, htlc, $opt_anchors))
1192 macro_rules! dumb_htlc_output {
1195 let preimage = PaymentPreimage([2;32]);
1196 PackageSolvingData::HolderHTLCOutput(HolderHTLCOutput::build_accepted(preimage, 0, ChannelTypeFeatures::only_static_remote_key()))
1203 fn test_package_differing_heights() {
1204 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1205 let secp_ctx = Secp256k1::new();
1206 let revk_outp = dumb_revk_output!(secp_ctx, false);
1208 let mut package_one_hundred = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, 100);
1209 let package_two_hundred = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, 200);
1210 package_one_hundred.merge_package(package_two_hundred);
1215 fn test_package_untractable_merge_to() {
1216 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1217 let secp_ctx = Secp256k1::new();
1218 let revk_outp = dumb_revk_output!(secp_ctx, false);
1219 let htlc_outp = dumb_htlc_output!();
1221 let mut untractable_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, 100);
1222 let malleable_package = PackageTemplate::build_package(txid, 1, htlc_outp.clone(), 1000, 100);
1223 untractable_package.merge_package(malleable_package);
1228 fn test_package_untractable_merge_from() {
1229 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1230 let secp_ctx = Secp256k1::new();
1231 let htlc_outp = dumb_htlc_output!();
1232 let revk_outp = dumb_revk_output!(secp_ctx, false);
1234 let mut malleable_package = PackageTemplate::build_package(txid, 0, htlc_outp.clone(), 1000, 100);
1235 let untractable_package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, 100);
1236 malleable_package.merge_package(untractable_package);
1241 fn test_package_noaggregation_to() {
1242 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1243 let secp_ctx = Secp256k1::new();
1244 let revk_outp = dumb_revk_output!(secp_ctx, false);
1245 let revk_outp_counterparty_balance = dumb_revk_output!(secp_ctx, true);
1247 let mut noaggregation_package = PackageTemplate::build_package(txid, 0, revk_outp_counterparty_balance.clone(), 1000, 100);
1248 let aggregation_package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, 100);
1249 noaggregation_package.merge_package(aggregation_package);
1254 fn test_package_noaggregation_from() {
1255 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1256 let secp_ctx = Secp256k1::new();
1257 let revk_outp = dumb_revk_output!(secp_ctx, false);
1258 let revk_outp_counterparty_balance = dumb_revk_output!(secp_ctx, true);
1260 let mut aggregation_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, 100);
1261 let noaggregation_package = PackageTemplate::build_package(txid, 1, revk_outp_counterparty_balance.clone(), 1000, 100);
1262 aggregation_package.merge_package(noaggregation_package);
1267 fn test_package_empty() {
1268 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1269 let secp_ctx = Secp256k1::new();
1270 let revk_outp = dumb_revk_output!(secp_ctx, false);
1272 let mut empty_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, 100);
1273 empty_package.inputs = vec![];
1274 let package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, 100);
1275 empty_package.merge_package(package);
1280 fn test_package_differing_categories() {
1281 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1282 let secp_ctx = Secp256k1::new();
1283 let revk_outp = dumb_revk_output!(secp_ctx, false);
1284 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 0, ChannelTypeFeatures::only_static_remote_key());
1286 let mut revoked_package = PackageTemplate::build_package(txid, 0, revk_outp, 1000, 100);
1287 let counterparty_package = PackageTemplate::build_package(txid, 1, counterparty_outp, 1000, 100);
1288 revoked_package.merge_package(counterparty_package);
1292 fn test_package_split_malleable() {
1293 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1294 let secp_ctx = Secp256k1::new();
1295 let revk_outp_one = dumb_revk_output!(secp_ctx, false);
1296 let revk_outp_two = dumb_revk_output!(secp_ctx, false);
1297 let revk_outp_three = dumb_revk_output!(secp_ctx, false);
1299 let mut package_one = PackageTemplate::build_package(txid, 0, revk_outp_one, 1000, 100);
1300 let package_two = PackageTemplate::build_package(txid, 1, revk_outp_two, 1000, 100);
1301 let package_three = PackageTemplate::build_package(txid, 2, revk_outp_three, 1000, 100);
1303 package_one.merge_package(package_two);
1304 package_one.merge_package(package_three);
1305 assert_eq!(package_one.outpoints().len(), 3);
1307 if let Some(split_package) = package_one.split_package(&BitcoinOutPoint { txid, vout: 1 }) {
1308 // Packages attributes should be identical
1309 assert!(split_package.is_malleable());
1310 assert_eq!(split_package.soonest_conf_deadline, package_one.soonest_conf_deadline);
1311 assert_eq!(split_package.aggregable, package_one.aggregable);
1312 assert_eq!(split_package.feerate_previous, package_one.feerate_previous);
1313 assert_eq!(split_package.height_timer, package_one.height_timer);
1314 assert_eq!(split_package.height_original, package_one.height_original);
1315 } else { panic!(); }
1316 assert_eq!(package_one.outpoints().len(), 2);
1320 fn test_package_split_untractable() {
1321 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1322 let htlc_outp_one = dumb_htlc_output!();
1324 let mut package_one = PackageTemplate::build_package(txid, 0, htlc_outp_one, 1000, 100);
1325 let ret_split = package_one.split_package(&BitcoinOutPoint { txid, vout: 0});
1326 assert!(ret_split.is_none());
1330 fn test_package_timer() {
1331 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1332 let secp_ctx = Secp256k1::new();
1333 let revk_outp = dumb_revk_output!(secp_ctx, false);
1335 let mut package = PackageTemplate::build_package(txid, 0, revk_outp, 1000, 100);
1336 assert_eq!(package.timer(), 100);
1337 package.set_timer(101);
1338 assert_eq!(package.timer(), 101);
1342 fn test_package_amounts() {
1343 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1344 let secp_ctx = Secp256k1::new();
1345 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 1_000_000, ChannelTypeFeatures::only_static_remote_key());
1347 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, 100);
1348 assert_eq!(package.package_amount(), 1000);
1352 fn test_package_weight() {
1353 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1354 let secp_ctx = Secp256k1::new();
1356 // (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 + witness marker (2)
1357 let weight_sans_output = (4 + 4 + 1 + 36 + 4 + 1 + 1 + 8 + 1) * WITNESS_SCALE_FACTOR + 2;
1360 let revk_outp = dumb_revk_output!(secp_ctx, false);
1361 let package = PackageTemplate::build_package(txid, 0, revk_outp, 0, 100);
1362 assert_eq!(package.package_weight(&Script::new()), weight_sans_output + WEIGHT_REVOKED_OUTPUT as usize);
1366 for channel_type_features in [ChannelTypeFeatures::only_static_remote_key(), ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies()].iter() {
1367 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 1_000_000, channel_type_features.clone());
1368 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, 100);
1369 assert_eq!(package.package_weight(&Script::new()), weight_sans_output + weight_received_htlc(channel_type_features) as usize);
1374 for channel_type_features in [ChannelTypeFeatures::only_static_remote_key(), ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies()].iter() {
1375 let counterparty_outp = dumb_counterparty_offered_output!(secp_ctx, 1_000_000, channel_type_features.clone());
1376 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, 100);
1377 assert_eq!(package.package_weight(&Script::new()), weight_sans_output + weight_offered_htlc(channel_type_features) as usize);