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.
15 use bitcoin::{Sequence, Witness};
16 use bitcoin::amount::Amount;
17 use bitcoin::blockdata::constants::WITNESS_SCALE_FACTOR;
18 use bitcoin::blockdata::locktime::absolute::LockTime;
19 use bitcoin::blockdata::transaction::{TxOut,TxIn, Transaction};
20 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
21 use bitcoin::blockdata::script::{Script, ScriptBuf};
22 use bitcoin::hash_types::Txid;
23 use bitcoin::secp256k1::{SecretKey,PublicKey};
24 use bitcoin::sighash::EcdsaSighashType;
25 use bitcoin::transaction::Version;
27 use crate::ln::types::PaymentPreimage;
28 use crate::ln::chan_utils::{self, TxCreationKeys, HTLCOutputInCommitment};
29 use crate::ln::features::ChannelTypeFeatures;
30 use crate::ln::channel_keys::{DelayedPaymentBasepoint, HtlcBasepoint};
31 use crate::ln::msgs::DecodeError;
32 use crate::chain::chaininterface::{FeeEstimator, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT, compute_feerate_sat_per_1000_weight, FEERATE_FLOOR_SATS_PER_KW};
33 use crate::chain::transaction::MaybeSignedTransaction;
34 use crate::sign::ecdsa::EcdsaChannelSigner;
35 use crate::chain::onchaintx::{FeerateStrategy, ExternalHTLCClaim, OnchainTxHandler};
36 use crate::util::logger::Logger;
37 use crate::util::ser::{Readable, Writer, Writeable, RequiredWrapper};
44 #[allow(unused_imports)]
45 use crate::prelude::*;
47 use super::chaininterface::LowerBoundedFeeEstimator;
49 const MAX_ALLOC_SIZE: usize = 64*1024;
52 pub(crate) fn weight_revoked_offered_htlc(channel_type_features: &ChannelTypeFeatures) -> u64 {
53 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
54 const WEIGHT_REVOKED_OFFERED_HTLC: u64 = 1 + 1 + 73 + 1 + 33 + 1 + 133;
55 const WEIGHT_REVOKED_OFFERED_HTLC_ANCHORS: u64 = WEIGHT_REVOKED_OFFERED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
56 if channel_type_features.supports_anchors_zero_fee_htlc_tx() { WEIGHT_REVOKED_OFFERED_HTLC_ANCHORS } else { WEIGHT_REVOKED_OFFERED_HTLC }
59 pub(crate) fn weight_revoked_received_htlc(channel_type_features: &ChannelTypeFeatures) -> u64 {
60 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
61 const WEIGHT_REVOKED_RECEIVED_HTLC: u64 = 1 + 1 + 73 + 1 + 33 + 1 + 139;
62 const WEIGHT_REVOKED_RECEIVED_HTLC_ANCHORS: u64 = WEIGHT_REVOKED_RECEIVED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
63 if channel_type_features.supports_anchors_zero_fee_htlc_tx() { WEIGHT_REVOKED_RECEIVED_HTLC_ANCHORS } else { WEIGHT_REVOKED_RECEIVED_HTLC }
66 pub(crate) fn weight_offered_htlc(channel_type_features: &ChannelTypeFeatures) -> u64 {
67 // number_of_witness_elements + sig_length + counterpartyhtlc_sig + preimage_length + preimage + witness_script_length + witness_script
68 const WEIGHT_OFFERED_HTLC: u64 = 1 + 1 + 73 + 1 + 32 + 1 + 133;
69 const WEIGHT_OFFERED_HTLC_ANCHORS: u64 = WEIGHT_OFFERED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
70 if channel_type_features.supports_anchors_zero_fee_htlc_tx() { WEIGHT_OFFERED_HTLC_ANCHORS } else { WEIGHT_OFFERED_HTLC }
73 pub(crate) fn weight_received_htlc(channel_type_features: &ChannelTypeFeatures) -> u64 {
74 // number_of_witness_elements + sig_length + counterpartyhtlc_sig + empty_vec_length + empty_vec + witness_script_length + witness_script
75 const WEIGHT_RECEIVED_HTLC: u64 = 1 + 1 + 73 + 1 + 1 + 1 + 139;
76 const WEIGHT_RECEIVED_HTLC_ANCHORS: u64 = WEIGHT_RECEIVED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
77 if channel_type_features.supports_anchors_zero_fee_htlc_tx() { WEIGHT_RECEIVED_HTLC_ANCHORS } else { WEIGHT_RECEIVED_HTLC }
80 /// Verifies deserializable channel type features
81 pub(crate) fn verify_channel_type_features(channel_type_features: &Option<ChannelTypeFeatures>, additional_permitted_features: Option<&ChannelTypeFeatures>) -> Result<(), DecodeError> {
82 if let Some(features) = channel_type_features.as_ref() {
83 if features.requires_unknown_bits() {
84 return Err(DecodeError::UnknownRequiredFeature);
87 let mut supported_feature_set = ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies();
88 supported_feature_set.set_scid_privacy_required();
89 supported_feature_set.set_zero_conf_required();
91 // allow the passing of an additional necessary permitted flag
92 if let Some(additional_permitted_features) = additional_permitted_features {
93 supported_feature_set |= additional_permitted_features;
96 if !features.is_subset(&supported_feature_set) {
97 return Err(DecodeError::UnknownRequiredFeature);
104 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
105 pub(crate) const WEIGHT_REVOKED_OUTPUT: u64 = 1 + 1 + 73 + 1 + 1 + 1 + 77;
107 /// Height delay at which transactions are fee-bumped/rebroadcasted with a low priority.
108 const LOW_FREQUENCY_BUMP_INTERVAL: u32 = 15;
109 /// Height delay at which transactions are fee-bumped/rebroadcasted with a middle priority.
110 const MIDDLE_FREQUENCY_BUMP_INTERVAL: u32 = 3;
111 /// Height delay at which transactions are fee-bumped/rebroadcasted with a high priority.
112 const HIGH_FREQUENCY_BUMP_INTERVAL: u32 = 1;
114 /// A struct to describe a revoked output and corresponding information to generate a solving
115 /// witness spending a commitment `to_local` output or a second-stage HTLC transaction output.
117 /// CSV and pubkeys are used as part of a witnessScript redeeming a balance output, amount is used
118 /// as part of the signature hash and revocation secret to generate a satisfying witness.
119 #[derive(Clone, PartialEq, Eq)]
120 pub(crate) struct RevokedOutput {
121 per_commitment_point: PublicKey,
122 counterparty_delayed_payment_base_key: DelayedPaymentBasepoint,
123 counterparty_htlc_base_key: HtlcBasepoint,
124 per_commitment_key: SecretKey,
127 on_counterparty_tx_csv: u16,
128 is_counterparty_balance_on_anchors: Option<()>,
132 pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: DelayedPaymentBasepoint, counterparty_htlc_base_key: HtlcBasepoint, per_commitment_key: SecretKey, amount: Amount, on_counterparty_tx_csv: u16, is_counterparty_balance_on_anchors: bool) -> Self {
134 per_commitment_point,
135 counterparty_delayed_payment_base_key,
136 counterparty_htlc_base_key,
138 weight: WEIGHT_REVOKED_OUTPUT,
140 on_counterparty_tx_csv,
141 is_counterparty_balance_on_anchors: if is_counterparty_balance_on_anchors { Some(()) } else { None }
146 impl_writeable_tlv_based!(RevokedOutput, {
147 (0, per_commitment_point, required),
148 (2, counterparty_delayed_payment_base_key, required),
149 (4, counterparty_htlc_base_key, required),
150 (6, per_commitment_key, required),
151 (8, weight, required),
152 (10, amount, required),
153 (12, on_counterparty_tx_csv, required),
154 (14, is_counterparty_balance_on_anchors, option)
157 /// A struct to describe a revoked offered output and corresponding information to generate a
160 /// HTLCOuputInCommitment (hash timelock, direction) and pubkeys are used to generate a suitable
163 /// CSV is used as part of a witnessScript redeeming a balance output, amount is used as part
164 /// of the signature hash and revocation secret to generate a satisfying witness.
165 #[derive(Clone, PartialEq, Eq)]
166 pub(crate) struct RevokedHTLCOutput {
167 per_commitment_point: PublicKey,
168 counterparty_delayed_payment_base_key: DelayedPaymentBasepoint,
169 counterparty_htlc_base_key: HtlcBasepoint,
170 per_commitment_key: SecretKey,
173 htlc: HTLCOutputInCommitment,
176 impl RevokedHTLCOutput {
177 pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: DelayedPaymentBasepoint, counterparty_htlc_base_key: HtlcBasepoint, per_commitment_key: SecretKey, amount: u64, htlc: HTLCOutputInCommitment, channel_type_features: &ChannelTypeFeatures) -> Self {
178 let weight = if htlc.offered { weight_revoked_offered_htlc(channel_type_features) } else { weight_revoked_received_htlc(channel_type_features) };
180 per_commitment_point,
181 counterparty_delayed_payment_base_key,
182 counterparty_htlc_base_key,
191 impl_writeable_tlv_based!(RevokedHTLCOutput, {
192 (0, per_commitment_point, required),
193 (2, counterparty_delayed_payment_base_key, required),
194 (4, counterparty_htlc_base_key, required),
195 (6, per_commitment_key, required),
196 (8, weight, required),
197 (10, amount, required),
198 (12, htlc, required),
201 /// A struct to describe a HTLC output on a counterparty commitment transaction.
203 /// HTLCOutputInCommitment (hash, timelock, directon) and pubkeys are used to generate a suitable
206 /// The preimage is used as part of the witness.
208 /// Note that on upgrades, some features of existing outputs may be missed.
209 #[derive(Clone, PartialEq, Eq)]
210 pub(crate) struct CounterpartyOfferedHTLCOutput {
211 per_commitment_point: PublicKey,
212 counterparty_delayed_payment_base_key: DelayedPaymentBasepoint,
213 counterparty_htlc_base_key: HtlcBasepoint,
214 preimage: PaymentPreimage,
215 htlc: HTLCOutputInCommitment,
216 channel_type_features: ChannelTypeFeatures,
219 impl CounterpartyOfferedHTLCOutput {
220 pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: DelayedPaymentBasepoint, counterparty_htlc_base_key: HtlcBasepoint, preimage: PaymentPreimage, htlc: HTLCOutputInCommitment, channel_type_features: ChannelTypeFeatures) -> Self {
221 CounterpartyOfferedHTLCOutput {
222 per_commitment_point,
223 counterparty_delayed_payment_base_key,
224 counterparty_htlc_base_key,
227 channel_type_features,
232 impl Writeable for CounterpartyOfferedHTLCOutput {
233 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
234 let legacy_deserialization_prevention_marker = chan_utils::legacy_deserialization_prevention_marker_for_channel_type_features(&self.channel_type_features);
235 write_tlv_fields!(writer, {
236 (0, self.per_commitment_point, required),
237 (2, self.counterparty_delayed_payment_base_key, required),
238 (4, self.counterparty_htlc_base_key, required),
239 (6, self.preimage, required),
240 (8, self.htlc, required),
241 (10, legacy_deserialization_prevention_marker, option),
242 (11, self.channel_type_features, required),
248 impl Readable for CounterpartyOfferedHTLCOutput {
249 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
250 let mut per_commitment_point = RequiredWrapper(None);
251 let mut counterparty_delayed_payment_base_key = RequiredWrapper(None);
252 let mut counterparty_htlc_base_key = RequiredWrapper(None);
253 let mut preimage = RequiredWrapper(None);
254 let mut htlc = RequiredWrapper(None);
255 let mut _legacy_deserialization_prevention_marker: Option<()> = None;
256 let mut channel_type_features = None;
258 read_tlv_fields!(reader, {
259 (0, per_commitment_point, required),
260 (2, counterparty_delayed_payment_base_key, required),
261 (4, counterparty_htlc_base_key, required),
262 (6, preimage, required),
264 (10, _legacy_deserialization_prevention_marker, option),
265 (11, channel_type_features, option),
268 verify_channel_type_features(&channel_type_features, None)?;
271 per_commitment_point: per_commitment_point.0.unwrap(),
272 counterparty_delayed_payment_base_key: counterparty_delayed_payment_base_key.0.unwrap(),
273 counterparty_htlc_base_key: counterparty_htlc_base_key.0.unwrap(),
274 preimage: preimage.0.unwrap(),
275 htlc: htlc.0.unwrap(),
276 channel_type_features: channel_type_features.unwrap_or(ChannelTypeFeatures::only_static_remote_key())
281 /// A struct to describe a HTLC output on a counterparty commitment transaction.
283 /// HTLCOutputInCommitment (hash, timelock, directon) and pubkeys are used to generate a suitable
286 /// Note that on upgrades, some features of existing outputs may be missed.
287 #[derive(Clone, PartialEq, Eq)]
288 pub(crate) struct CounterpartyReceivedHTLCOutput {
289 per_commitment_point: PublicKey,
290 counterparty_delayed_payment_base_key: DelayedPaymentBasepoint,
291 counterparty_htlc_base_key: HtlcBasepoint,
292 htlc: HTLCOutputInCommitment,
293 channel_type_features: ChannelTypeFeatures,
296 impl CounterpartyReceivedHTLCOutput {
297 pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: DelayedPaymentBasepoint, counterparty_htlc_base_key: HtlcBasepoint, htlc: HTLCOutputInCommitment, channel_type_features: ChannelTypeFeatures) -> Self {
298 CounterpartyReceivedHTLCOutput {
299 per_commitment_point,
300 counterparty_delayed_payment_base_key,
301 counterparty_htlc_base_key,
303 channel_type_features
308 impl Writeable for CounterpartyReceivedHTLCOutput {
309 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
310 let legacy_deserialization_prevention_marker = chan_utils::legacy_deserialization_prevention_marker_for_channel_type_features(&self.channel_type_features);
311 write_tlv_fields!(writer, {
312 (0, self.per_commitment_point, required),
313 (2, self.counterparty_delayed_payment_base_key, required),
314 (4, self.counterparty_htlc_base_key, required),
315 (6, self.htlc, required),
316 (8, legacy_deserialization_prevention_marker, option),
317 (9, self.channel_type_features, required),
323 impl Readable for CounterpartyReceivedHTLCOutput {
324 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
325 let mut per_commitment_point = RequiredWrapper(None);
326 let mut counterparty_delayed_payment_base_key = RequiredWrapper(None);
327 let mut counterparty_htlc_base_key = RequiredWrapper(None);
328 let mut htlc = RequiredWrapper(None);
329 let mut _legacy_deserialization_prevention_marker: Option<()> = None;
330 let mut channel_type_features = None;
332 read_tlv_fields!(reader, {
333 (0, per_commitment_point, required),
334 (2, counterparty_delayed_payment_base_key, required),
335 (4, counterparty_htlc_base_key, required),
337 (8, _legacy_deserialization_prevention_marker, option),
338 (9, channel_type_features, option),
341 verify_channel_type_features(&channel_type_features, None)?;
344 per_commitment_point: per_commitment_point.0.unwrap(),
345 counterparty_delayed_payment_base_key: counterparty_delayed_payment_base_key.0.unwrap(),
346 counterparty_htlc_base_key: counterparty_htlc_base_key.0.unwrap(),
347 htlc: htlc.0.unwrap(),
348 channel_type_features: channel_type_features.unwrap_or(ChannelTypeFeatures::only_static_remote_key())
353 /// A struct to describe a HTLC output on holder commitment transaction.
355 /// Either offered or received, the amount is always used as part of the bip143 sighash.
356 /// Preimage is only included as part of the witness in former case.
358 /// Note that on upgrades, some features of existing outputs may be missed.
359 #[derive(Clone, PartialEq, Eq)]
360 pub(crate) struct HolderHTLCOutput {
361 preimage: Option<PaymentPreimage>,
363 /// Defaults to 0 for HTLC-Success transactions, which have no expiry
365 channel_type_features: ChannelTypeFeatures,
368 impl HolderHTLCOutput {
369 pub(crate) fn build_offered(amount_msat: u64, cltv_expiry: u32, channel_type_features: ChannelTypeFeatures) -> Self {
374 channel_type_features,
378 pub(crate) fn build_accepted(preimage: PaymentPreimage, amount_msat: u64, channel_type_features: ChannelTypeFeatures) -> Self {
380 preimage: Some(preimage),
383 channel_type_features,
388 impl Writeable for HolderHTLCOutput {
389 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
390 let legacy_deserialization_prevention_marker = chan_utils::legacy_deserialization_prevention_marker_for_channel_type_features(&self.channel_type_features);
391 write_tlv_fields!(writer, {
392 (0, self.amount_msat, required),
393 (2, self.cltv_expiry, required),
394 (4, self.preimage, option),
395 (6, legacy_deserialization_prevention_marker, option),
396 (7, self.channel_type_features, required),
402 impl Readable for HolderHTLCOutput {
403 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
404 let mut amount_msat = RequiredWrapper(None);
405 let mut cltv_expiry = RequiredWrapper(None);
406 let mut preimage = None;
407 let mut _legacy_deserialization_prevention_marker: Option<()> = None;
408 let mut channel_type_features = None;
410 read_tlv_fields!(reader, {
411 (0, amount_msat, required),
412 (2, cltv_expiry, required),
413 (4, preimage, option),
414 (6, _legacy_deserialization_prevention_marker, option),
415 (7, channel_type_features, option),
418 verify_channel_type_features(&channel_type_features, None)?;
421 amount_msat: amount_msat.0.unwrap(),
422 cltv_expiry: cltv_expiry.0.unwrap(),
424 channel_type_features: channel_type_features.unwrap_or(ChannelTypeFeatures::only_static_remote_key())
429 /// A struct to describe the channel output on the funding transaction.
431 /// witnessScript is used as part of the witness redeeming the funding utxo.
433 /// Note that on upgrades, some features of existing outputs may be missed.
434 #[derive(Clone, PartialEq, Eq)]
435 pub(crate) struct HolderFundingOutput {
436 funding_redeemscript: ScriptBuf,
437 pub(crate) funding_amount: Option<u64>,
438 channel_type_features: ChannelTypeFeatures,
442 impl HolderFundingOutput {
443 pub(crate) fn build(funding_redeemscript: ScriptBuf, funding_amount: u64, channel_type_features: ChannelTypeFeatures) -> Self {
444 HolderFundingOutput {
445 funding_redeemscript,
446 funding_amount: Some(funding_amount),
447 channel_type_features,
452 impl Writeable for HolderFundingOutput {
453 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
454 let legacy_deserialization_prevention_marker = chan_utils::legacy_deserialization_prevention_marker_for_channel_type_features(&self.channel_type_features);
455 write_tlv_fields!(writer, {
456 (0, self.funding_redeemscript, required),
457 (1, self.channel_type_features, required),
458 (2, legacy_deserialization_prevention_marker, option),
459 (3, self.funding_amount, option),
465 impl Readable for HolderFundingOutput {
466 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
467 let mut funding_redeemscript = RequiredWrapper(None);
468 let mut _legacy_deserialization_prevention_marker: Option<()> = None;
469 let mut channel_type_features = None;
470 let mut funding_amount = None;
472 read_tlv_fields!(reader, {
473 (0, funding_redeemscript, required),
474 (1, channel_type_features, option),
475 (2, _legacy_deserialization_prevention_marker, option),
476 (3, funding_amount, option)
479 verify_channel_type_features(&channel_type_features, None)?;
482 funding_redeemscript: funding_redeemscript.0.unwrap(),
483 channel_type_features: channel_type_features.unwrap_or(ChannelTypeFeatures::only_static_remote_key()),
489 /// A wrapper encapsulating all in-protocol differing outputs types.
491 /// The generic API offers access to an outputs common attributes or allow transformation such as
492 /// finalizing an input claiming the output.
493 #[derive(Clone, PartialEq, Eq)]
494 pub(crate) enum PackageSolvingData {
495 RevokedOutput(RevokedOutput),
496 RevokedHTLCOutput(RevokedHTLCOutput),
497 CounterpartyOfferedHTLCOutput(CounterpartyOfferedHTLCOutput),
498 CounterpartyReceivedHTLCOutput(CounterpartyReceivedHTLCOutput),
499 HolderHTLCOutput(HolderHTLCOutput),
500 HolderFundingOutput(HolderFundingOutput),
503 impl PackageSolvingData {
504 fn amount(&self) -> u64 {
505 let amt = match self {
506 PackageSolvingData::RevokedOutput(ref outp) => outp.amount.to_sat(),
507 PackageSolvingData::RevokedHTLCOutput(ref outp) => outp.amount,
508 PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => outp.htlc.amount_msat / 1000,
509 PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => outp.htlc.amount_msat / 1000,
510 PackageSolvingData::HolderHTLCOutput(ref outp) => {
511 debug_assert!(outp.channel_type_features.supports_anchors_zero_fee_htlc_tx());
512 outp.amount_msat / 1000
514 PackageSolvingData::HolderFundingOutput(ref outp) => {
515 debug_assert!(outp.channel_type_features.supports_anchors_zero_fee_htlc_tx());
516 outp.funding_amount.unwrap()
521 fn weight(&self) -> usize {
523 PackageSolvingData::RevokedOutput(ref outp) => outp.weight as usize,
524 PackageSolvingData::RevokedHTLCOutput(ref outp) => outp.weight as usize,
525 PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => weight_offered_htlc(&outp.channel_type_features) as usize,
526 PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => weight_received_htlc(&outp.channel_type_features) as usize,
527 PackageSolvingData::HolderHTLCOutput(ref outp) => {
528 debug_assert!(outp.channel_type_features.supports_anchors_zero_fee_htlc_tx());
529 if outp.preimage.is_none() {
530 weight_offered_htlc(&outp.channel_type_features) as usize
532 weight_received_htlc(&outp.channel_type_features) as usize
535 // Since HolderFundingOutput maps to an untractable package that is already signed, its
536 // weight can be determined from the transaction itself.
537 PackageSolvingData::HolderFundingOutput(..) => unreachable!(),
540 fn is_compatible(&self, input: &PackageSolvingData) -> bool {
542 PackageSolvingData::RevokedOutput(..) => {
544 PackageSolvingData::RevokedHTLCOutput(..) => { true },
545 PackageSolvingData::RevokedOutput(..) => { true },
549 PackageSolvingData::RevokedHTLCOutput(..) => {
551 PackageSolvingData::RevokedOutput(..) => { true },
552 PackageSolvingData::RevokedHTLCOutput(..) => { true },
556 _ => { mem::discriminant(self) == mem::discriminant(&input) }
559 fn as_tx_input(&self, previous_output: BitcoinOutPoint) -> TxIn {
560 let sequence = match self {
561 PackageSolvingData::RevokedOutput(_) => Sequence::ENABLE_RBF_NO_LOCKTIME,
562 PackageSolvingData::RevokedHTLCOutput(_) => Sequence::ENABLE_RBF_NO_LOCKTIME,
563 PackageSolvingData::CounterpartyOfferedHTLCOutput(outp) => if outp.channel_type_features.supports_anchors_zero_fee_htlc_tx() {
564 Sequence::from_consensus(1)
566 Sequence::ENABLE_RBF_NO_LOCKTIME
568 PackageSolvingData::CounterpartyReceivedHTLCOutput(outp) => if outp.channel_type_features.supports_anchors_zero_fee_htlc_tx() {
569 Sequence::from_consensus(1)
571 Sequence::ENABLE_RBF_NO_LOCKTIME
574 debug_assert!(false, "This should not be reachable by 'untractable' or 'malleable with external funding' packages");
575 Sequence::ENABLE_RBF_NO_LOCKTIME
580 script_sig: ScriptBuf::new(),
582 witness: Witness::new(),
585 fn finalize_input<Signer: EcdsaChannelSigner>(&self, bumped_tx: &mut Transaction, i: usize, onchain_handler: &mut OnchainTxHandler<Signer>) -> bool {
587 PackageSolvingData::RevokedOutput(ref outp) => {
588 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);
589 let witness_script = chan_utils::get_revokeable_redeemscript(&chan_keys.revocation_key, outp.on_counterparty_tx_csv, &chan_keys.broadcaster_delayed_payment_key);
590 //TODO: should we panic on signer failure ?
591 if let Ok(sig) = onchain_handler.signer.sign_justice_revoked_output(&bumped_tx, i, outp.amount.to_sat(), &outp.per_commitment_key, &onchain_handler.secp_ctx) {
592 let mut ser_sig = sig.serialize_der().to_vec();
593 ser_sig.push(EcdsaSighashType::All as u8);
594 bumped_tx.input[i].witness.push(ser_sig);
595 bumped_tx.input[i].witness.push(vec!(1));
596 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
597 } else { return false; }
599 PackageSolvingData::RevokedHTLCOutput(ref outp) => {
600 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);
601 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);
602 //TODO: should we panic on signer failure ?
603 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) {
604 let mut ser_sig = sig.serialize_der().to_vec();
605 ser_sig.push(EcdsaSighashType::All as u8);
606 bumped_tx.input[i].witness.push(ser_sig);
607 bumped_tx.input[i].witness.push(chan_keys.revocation_key.to_public_key().serialize().to_vec());
608 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
609 } else { return false; }
611 PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => {
612 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);
613 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);
615 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) {
616 let mut ser_sig = sig.serialize_der().to_vec();
617 ser_sig.push(EcdsaSighashType::All as u8);
618 bumped_tx.input[i].witness.push(ser_sig);
619 bumped_tx.input[i].witness.push(outp.preimage.0.to_vec());
620 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
623 PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => {
624 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);
625 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);
627 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) {
628 let mut ser_sig = sig.serialize_der().to_vec();
629 ser_sig.push(EcdsaSighashType::All as u8);
630 bumped_tx.input[i].witness.push(ser_sig);
631 // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
632 bumped_tx.input[i].witness.push(vec![]);
633 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
636 _ => { panic!("API Error!"); }
640 fn get_maybe_finalized_tx<Signer: EcdsaChannelSigner>(&self, outpoint: &BitcoinOutPoint, onchain_handler: &mut OnchainTxHandler<Signer>) -> Option<MaybeSignedTransaction> {
642 PackageSolvingData::HolderHTLCOutput(ref outp) => {
643 debug_assert!(!outp.channel_type_features.supports_anchors_zero_fee_htlc_tx());
644 onchain_handler.get_maybe_signed_htlc_tx(outpoint, &outp.preimage)
646 PackageSolvingData::HolderFundingOutput(ref outp) => {
647 Some(onchain_handler.get_maybe_signed_holder_tx(&outp.funding_redeemscript))
649 _ => { panic!("API Error!"); }
652 fn absolute_tx_timelock(&self, current_height: u32) -> u32 {
653 // We use `current_height` as our default locktime to discourage fee sniping and because
654 // transactions with it always propagate.
655 let absolute_timelock = match self {
656 PackageSolvingData::RevokedOutput(_) => current_height,
657 PackageSolvingData::RevokedHTLCOutput(_) => current_height,
658 PackageSolvingData::CounterpartyOfferedHTLCOutput(_) => current_height,
659 PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => cmp::max(outp.htlc.cltv_expiry, current_height),
660 // HTLC timeout/success transactions rely on a fixed timelock due to the counterparty's
662 PackageSolvingData::HolderHTLCOutput(ref outp) => {
663 if outp.preimage.is_some() {
664 debug_assert_eq!(outp.cltv_expiry, 0);
668 PackageSolvingData::HolderFundingOutput(_) => current_height,
673 fn map_output_type_flags(&self) -> (PackageMalleability, bool) {
674 // Post-anchor, aggregation of outputs of different types is unsafe. See https://github.com/lightning/bolts/pull/803.
675 let (malleability, aggregable) = match self {
676 PackageSolvingData::RevokedOutput(RevokedOutput { is_counterparty_balance_on_anchors: Some(()), .. }) => { (PackageMalleability::Malleable, false) },
677 PackageSolvingData::RevokedOutput(RevokedOutput { is_counterparty_balance_on_anchors: None, .. }) => { (PackageMalleability::Malleable, true) },
678 PackageSolvingData::RevokedHTLCOutput(..) => { (PackageMalleability::Malleable, true) },
679 PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => { (PackageMalleability::Malleable, true) },
680 PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => { (PackageMalleability::Malleable, false) },
681 PackageSolvingData::HolderHTLCOutput(ref outp) => if outp.channel_type_features.supports_anchors_zero_fee_htlc_tx() {
682 (PackageMalleability::Malleable, outp.preimage.is_some())
684 (PackageMalleability::Untractable, false)
686 PackageSolvingData::HolderFundingOutput(..) => { (PackageMalleability::Untractable, false) },
688 (malleability, aggregable)
692 impl_writeable_tlv_based_enum!(PackageSolvingData, ;
694 (1, RevokedHTLCOutput),
695 (2, CounterpartyOfferedHTLCOutput),
696 (3, CounterpartyReceivedHTLCOutput),
697 (4, HolderHTLCOutput),
698 (5, HolderFundingOutput),
701 /// A malleable package might be aggregated with other packages to save on fees.
702 /// A untractable package has been counter-signed and aggregable will break cached counterparty signatures.
703 #[derive(Clone, PartialEq, Eq)]
704 pub(crate) enum PackageMalleability {
709 /// A structure to describe a package content that is generated by ChannelMonitor and
710 /// used by OnchainTxHandler to generate and broadcast transactions settling onchain claims.
712 /// A package is defined as one or more transactions claiming onchain outputs in reaction
713 /// to confirmation of a channel transaction. Those packages might be aggregated to save on
714 /// fees, if satisfaction of outputs's witnessScript let's us do so.
716 /// As packages are time-sensitive, we fee-bump and rebroadcast them at scheduled intervals.
717 /// Failing to confirm a package translate as a loss of funds for the user.
718 #[derive(Clone, PartialEq, Eq)]
719 pub struct PackageTemplate {
720 // List of onchain outputs and solving data to generate satisfying witnesses.
721 inputs: Vec<(BitcoinOutPoint, PackageSolvingData)>,
722 // Packages are deemed as malleable if we have local knwoledge of at least one set of
723 // private keys yielding a satisfying witnesses. Malleability implies that we can aggregate
724 // packages among them to save on fees or rely on RBF to bump their feerates.
725 // Untractable packages have been counter-signed and thus imply that we can't aggregate
726 // them without breaking signatures. Fee-bumping strategy will also rely on CPFP.
727 malleability: PackageMalleability,
728 // Block height after which the earlier-output belonging to this package is mature for a
729 // competing claim by the counterparty. As our chain tip becomes nearer from the timelock,
730 // the fee-bumping frequency will increase. See `OnchainTxHandler::get_height_timer`.
731 soonest_conf_deadline: u32,
732 // Determines if this package can be aggregated.
733 // Timelocked outputs belonging to the same transaction might have differing
734 // satisfying heights. Picking up the later height among the output set would be a valid
735 // aggregable strategy but it comes with at least 2 trade-offs :
736 // * earlier-output fund are going to take longer to come back
737 // * CLTV delta backing up a corresponding HTLC on an upstream channel could be swallowed
738 // by the requirement of the later-output part of the set
739 // For now, we mark such timelocked outputs as non-aggregable, though we might introduce
740 // smarter aggregable strategy in the future.
742 // Cache of package feerate committed at previous (re)broadcast. If bumping resources
743 // (either claimed output value or external utxo), it will keep increasing until holder
744 // or counterparty successful claim.
745 feerate_previous: u64,
746 // Cache of next height at which fee-bumping and rebroadcast will be attempted. In
747 // the future, we might abstract it to an observed mempool fluctuation.
749 // Confirmation height of the claimed outputs set transaction. In case of reorg reaching
750 // it, we wipe out and forget the package.
751 height_original: u32,
754 impl PackageTemplate {
755 pub(crate) fn is_malleable(&self) -> bool {
756 self.malleability == PackageMalleability::Malleable
758 pub(crate) fn timelock(&self) -> u32 {
759 self.soonest_conf_deadline
761 pub(crate) fn aggregable(&self) -> bool {
764 pub(crate) fn previous_feerate(&self) -> u64 {
765 self.feerate_previous
767 pub(crate) fn set_feerate(&mut self, new_feerate: u64) {
768 self.feerate_previous = new_feerate;
770 pub(crate) fn timer(&self) -> u32 {
773 pub(crate) fn set_timer(&mut self, new_timer: u32) {
774 self.height_timer = new_timer;
776 pub(crate) fn outpoints(&self) -> Vec<&BitcoinOutPoint> {
777 self.inputs.iter().map(|(o, _)| o).collect()
779 pub(crate) fn inputs(&self) -> impl ExactSizeIterator<Item = &PackageSolvingData> {
780 self.inputs.iter().map(|(_, i)| i)
782 pub(crate) fn split_package(&mut self, split_outp: &BitcoinOutPoint) -> Option<PackageTemplate> {
783 match self.malleability {
784 PackageMalleability::Malleable => {
785 let mut split_package = None;
786 let timelock = self.soonest_conf_deadline;
787 let aggregable = self.aggregable;
788 let feerate_previous = self.feerate_previous;
789 let height_timer = self.height_timer;
790 let height_original = self.height_original;
791 self.inputs.retain(|outp| {
792 if *split_outp == outp.0 {
793 split_package = Some(PackageTemplate {
794 inputs: vec![(outp.0, outp.1.clone())],
795 malleability: PackageMalleability::Malleable,
796 soonest_conf_deadline: timelock,
806 return split_package;
809 // Note, we may try to split on remote transaction for
810 // which we don't have a competing one (HTLC-Success before
811 // timelock expiration). This explain we don't panic!
812 // We should refactor OnchainTxHandler::block_connected to
813 // only test equality on competing claims.
818 pub(crate) fn merge_package(&mut self, mut merge_from: PackageTemplate) {
819 assert_eq!(self.height_original, merge_from.height_original);
820 if self.malleability == PackageMalleability::Untractable || merge_from.malleability == PackageMalleability::Untractable {
821 panic!("Merging template on untractable packages");
823 if !self.aggregable || !merge_from.aggregable {
824 panic!("Merging non aggregatable packages");
826 if let Some((_, lead_input)) = self.inputs.first() {
827 for (_, v) in merge_from.inputs.iter() {
828 if !lead_input.is_compatible(v) { panic!("Merging outputs from differing types !"); }
830 } else { panic!("Merging template on an empty package"); }
831 for (k, v) in merge_from.inputs.drain(..) {
832 self.inputs.push((k, v));
834 //TODO: verify coverage and sanity?
835 if self.soonest_conf_deadline > merge_from.soonest_conf_deadline {
836 self.soonest_conf_deadline = merge_from.soonest_conf_deadline;
838 if self.feerate_previous > merge_from.feerate_previous {
839 self.feerate_previous = merge_from.feerate_previous;
841 self.height_timer = cmp::min(self.height_timer, merge_from.height_timer);
843 /// Gets the amount of all outptus being spent by this package, only valid for malleable
845 pub(crate) fn package_amount(&self) -> u64 {
847 for (_, outp) in self.inputs.iter() {
848 amounts += outp.amount();
852 pub(crate) fn package_locktime(&self, current_height: u32) -> u32 {
853 let locktime = self.inputs.iter().map(|(_, outp)| outp.absolute_tx_timelock(current_height))
854 .max().expect("There must always be at least one output to spend in a PackageTemplate");
856 // If we ever try to aggregate a `HolderHTLCOutput`s with another output type, we'll likely
857 // end up with an incorrect transaction locktime since the counterparty has included it in
858 // its HTLC signature. This should never happen unless we decide to aggregate outputs across
859 // different channel commitments.
860 #[cfg(debug_assertions)] {
861 if self.inputs.iter().any(|(_, outp)|
862 if let PackageSolvingData::HolderHTLCOutput(outp) = outp {
863 outp.preimage.is_some()
868 debug_assert_eq!(locktime, 0);
870 for timeout_htlc_expiry in self.inputs.iter().filter_map(|(_, outp)|
871 if let PackageSolvingData::HolderHTLCOutput(outp) = outp {
872 if outp.preimage.is_none() {
873 Some(outp.cltv_expiry)
877 debug_assert_eq!(locktime, timeout_htlc_expiry);
883 pub(crate) fn package_weight(&self, destination_script: &Script) -> u64 {
884 let mut inputs_weight = 0;
885 let mut witnesses_weight = 2; // count segwit flags
886 for (_, outp) in self.inputs.iter() {
887 // previous_out_point: 36 bytes ; var_int: 1 byte ; sequence: 4 bytes
888 inputs_weight += 41 * WITNESS_SCALE_FACTOR;
889 witnesses_weight += outp.weight();
891 // version: 4 bytes ; count_tx_in: 1 byte ; count_tx_out: 1 byte ; lock_time: 4 bytes
892 let transaction_weight = 10 * WITNESS_SCALE_FACTOR;
893 // value: 8 bytes ; var_int: 1 byte ; pk_script: `destination_script.len()`
894 let output_weight = (8 + 1 + destination_script.len()) * WITNESS_SCALE_FACTOR;
895 (inputs_weight + witnesses_weight + transaction_weight + output_weight) as u64
897 pub(crate) fn construct_malleable_package_with_external_funding<Signer: EcdsaChannelSigner>(
898 &self, onchain_handler: &mut OnchainTxHandler<Signer>,
899 ) -> Option<Vec<ExternalHTLCClaim>> {
900 debug_assert!(self.requires_external_funding());
901 let mut htlcs: Option<Vec<ExternalHTLCClaim>> = None;
902 for (previous_output, input) in &self.inputs {
904 PackageSolvingData::HolderHTLCOutput(ref outp) => {
905 debug_assert!(outp.channel_type_features.supports_anchors_zero_fee_htlc_tx());
906 onchain_handler.generate_external_htlc_claim(&previous_output, &outp.preimage).map(|htlc| {
907 htlcs.get_or_insert_with(|| Vec::with_capacity(self.inputs.len())).push(htlc);
910 _ => debug_assert!(false, "Expected HolderHTLCOutputs to not be aggregated with other input types"),
915 pub(crate) fn maybe_finalize_malleable_package<L: Logger, Signer: EcdsaChannelSigner>(
916 &self, current_height: u32, onchain_handler: &mut OnchainTxHandler<Signer>, value: Amount,
917 destination_script: ScriptBuf, logger: &L
918 ) -> Option<MaybeSignedTransaction> {
919 debug_assert!(self.is_malleable());
920 let mut bumped_tx = Transaction {
921 version: Version::TWO,
922 lock_time: LockTime::from_consensus(self.package_locktime(current_height)),
925 script_pubkey: destination_script,
929 for (outpoint, outp) in self.inputs.iter() {
930 bumped_tx.input.push(outp.as_tx_input(*outpoint));
932 for (i, (outpoint, out)) in self.inputs.iter().enumerate() {
933 log_debug!(logger, "Adding claiming input for outpoint {}:{}", outpoint.txid, outpoint.vout);
934 if !out.finalize_input(&mut bumped_tx, i, onchain_handler) { continue; }
936 Some(MaybeSignedTransaction(bumped_tx))
938 pub(crate) fn maybe_finalize_untractable_package<L: Logger, Signer: EcdsaChannelSigner>(
939 &self, onchain_handler: &mut OnchainTxHandler<Signer>, logger: &L,
940 ) -> Option<MaybeSignedTransaction> {
941 debug_assert!(!self.is_malleable());
942 if let Some((outpoint, outp)) = self.inputs.first() {
943 if let Some(final_tx) = outp.get_maybe_finalized_tx(outpoint, onchain_handler) {
944 log_debug!(logger, "Adding claiming input for outpoint {}:{}", outpoint.txid, outpoint.vout);
945 return Some(final_tx);
948 } else { panic!("API Error: Package must not be inputs empty"); }
950 /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
951 /// 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
952 /// height that once reached we should generate a new bumped "version" of the claim tx to be sure that we safely claim outputs before
953 /// that our counterparty can do so. If timelock expires soon, height timer is going to be scaled down in consequence to increase
954 /// frequency of the bump and so increase our bets of success.
955 pub(crate) fn get_height_timer(&self, current_height: u32) -> u32 {
956 if self.soonest_conf_deadline <= current_height + MIDDLE_FREQUENCY_BUMP_INTERVAL {
957 return current_height + HIGH_FREQUENCY_BUMP_INTERVAL
958 } else if self.soonest_conf_deadline - current_height <= LOW_FREQUENCY_BUMP_INTERVAL {
959 return current_height + MIDDLE_FREQUENCY_BUMP_INTERVAL
961 current_height + LOW_FREQUENCY_BUMP_INTERVAL
964 /// Returns value in satoshis to be included as package outgoing output amount and feerate
965 /// which was used to generate the value. Will not return less than `dust_limit_sats` for the
967 pub(crate) fn compute_package_output<F: Deref, L: Logger>(
968 &self, predicted_weight: u64, dust_limit_sats: u64, feerate_strategy: &FeerateStrategy,
969 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L,
970 ) -> Option<(u64, u64)>
971 where F::Target: FeeEstimator,
973 debug_assert!(self.malleability == PackageMalleability::Malleable, "The package output is fixed for non-malleable packages");
974 let input_amounts = self.package_amount();
975 assert!(dust_limit_sats as i64 > 0, "Output script must be broadcastable/have a 'real' dust limit.");
976 // If old feerate is 0, first iteration of this claim, use normal fee calculation
977 if self.feerate_previous != 0 {
978 if let Some((new_fee, feerate)) = feerate_bump(
979 predicted_weight, input_amounts, self.feerate_previous, feerate_strategy,
980 fee_estimator, logger,
982 return Some((cmp::max(input_amounts as i64 - new_fee as i64, dust_limit_sats as i64) as u64, feerate));
985 if let Some((new_fee, feerate)) = compute_fee_from_spent_amounts(input_amounts, predicted_weight, fee_estimator, logger) {
986 return Some((cmp::max(input_amounts as i64 - new_fee as i64, dust_limit_sats as i64) as u64, feerate));
992 /// Computes a feerate based on the given confirmation target and feerate strategy.
993 pub(crate) fn compute_package_feerate<F: Deref>(
994 &self, fee_estimator: &LowerBoundedFeeEstimator<F>, conf_target: ConfirmationTarget,
995 feerate_strategy: &FeerateStrategy,
996 ) -> u32 where F::Target: FeeEstimator {
997 let feerate_estimate = fee_estimator.bounded_sat_per_1000_weight(conf_target);
998 if self.feerate_previous != 0 {
999 let previous_feerate = self.feerate_previous.try_into().unwrap_or(u32::max_value());
1000 match feerate_strategy {
1001 FeerateStrategy::RetryPrevious => previous_feerate,
1002 FeerateStrategy::HighestOfPreviousOrNew => cmp::max(previous_feerate, feerate_estimate),
1003 FeerateStrategy::ForceBump => if feerate_estimate > previous_feerate {
1006 // Our fee estimate has decreased, but our transaction remains unconfirmed after
1007 // using our previous fee estimate. This may point to an unreliable fee estimator,
1008 // so we choose to bump our previous feerate by 25%, making sure we don't use a
1009 // lower feerate or overpay by a large margin by limiting it to 5x the new fee
1011 let previous_feerate = self.feerate_previous.try_into().unwrap_or(u32::max_value());
1012 let mut new_feerate = previous_feerate.saturating_add(previous_feerate / 4);
1013 if new_feerate > feerate_estimate * 5 {
1014 new_feerate = cmp::max(feerate_estimate * 5, previous_feerate);
1024 /// Determines whether a package contains an input which must have additional external inputs
1025 /// attached to help the spending transaction reach confirmation.
1026 pub(crate) fn requires_external_funding(&self) -> bool {
1027 self.inputs.iter().find(|input| match input.1 {
1028 PackageSolvingData::HolderFundingOutput(ref outp) => outp.channel_type_features.supports_anchors_zero_fee_htlc_tx(),
1029 PackageSolvingData::HolderHTLCOutput(ref outp) => outp.channel_type_features.supports_anchors_zero_fee_htlc_tx(),
1034 pub (crate) fn build_package(txid: Txid, vout: u32, input_solving_data: PackageSolvingData, soonest_conf_deadline: u32, height_original: u32) -> Self {
1035 let (malleability, aggregable) = PackageSolvingData::map_output_type_flags(&input_solving_data);
1036 let mut inputs = Vec::with_capacity(1);
1037 inputs.push((BitcoinOutPoint { txid, vout }, input_solving_data));
1041 soonest_conf_deadline,
1043 feerate_previous: 0,
1044 height_timer: height_original,
1050 impl Writeable for PackageTemplate {
1051 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
1052 writer.write_all(&(self.inputs.len() as u64).to_be_bytes())?;
1053 for (ref outpoint, ref rev_outp) in self.inputs.iter() {
1054 outpoint.write(writer)?;
1055 rev_outp.write(writer)?;
1057 write_tlv_fields!(writer, {
1058 (0, self.soonest_conf_deadline, required),
1059 (2, self.feerate_previous, required),
1060 (4, self.height_original, required),
1061 (6, self.height_timer, required)
1067 impl Readable for PackageTemplate {
1068 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
1069 let inputs_count = <u64 as Readable>::read(reader)?;
1070 let mut inputs: Vec<(BitcoinOutPoint, PackageSolvingData)> = Vec::with_capacity(cmp::min(inputs_count as usize, MAX_ALLOC_SIZE / 128));
1071 for _ in 0..inputs_count {
1072 let outpoint = Readable::read(reader)?;
1073 let rev_outp = Readable::read(reader)?;
1074 inputs.push((outpoint, rev_outp));
1076 let (malleability, aggregable) = if let Some((_, lead_input)) = inputs.first() {
1077 PackageSolvingData::map_output_type_flags(&lead_input)
1078 } else { return Err(DecodeError::InvalidValue); };
1079 let mut soonest_conf_deadline = 0;
1080 let mut feerate_previous = 0;
1081 let mut height_timer = None;
1082 let mut height_original = 0;
1083 read_tlv_fields!(reader, {
1084 (0, soonest_conf_deadline, required),
1085 (2, feerate_previous, required),
1086 (4, height_original, required),
1087 (6, height_timer, option),
1089 if height_timer.is_none() {
1090 height_timer = Some(height_original);
1092 Ok(PackageTemplate {
1095 soonest_conf_deadline,
1098 height_timer: height_timer.unwrap(),
1104 /// Attempt to propose a bumping fee for a transaction from its spent output's values and predicted
1105 /// weight. We first try our [`OnChainSweep`] feerate, if it's not enough we try to sweep half of
1106 /// the input amounts.
1108 /// If the proposed fee is less than the available spent output's values, we return the proposed
1109 /// fee and the corresponding updated feerate. If fee is under [`FEERATE_FLOOR_SATS_PER_KW`], we
1112 /// [`OnChainSweep`]: crate::chain::chaininterface::ConfirmationTarget::OnChainSweep
1113 /// [`FEERATE_FLOOR_SATS_PER_KW`]: crate::chain::chaininterface::MIN_RELAY_FEE_SAT_PER_1000_WEIGHT
1114 fn compute_fee_from_spent_amounts<F: Deref, L: Logger>(input_amounts: u64, predicted_weight: u64, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L) -> Option<(u64, u64)>
1115 where F::Target: FeeEstimator,
1117 let sweep_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::OnChainSweep);
1118 let fee_rate = cmp::min(sweep_feerate, compute_feerate_sat_per_1000_weight(input_amounts / 2, predicted_weight));
1119 let fee = fee_rate as u64 * (predicted_weight) / 1000;
1121 // if the fee rate is below the floor, we don't sweep
1122 if fee_rate < FEERATE_FLOOR_SATS_PER_KW {
1123 log_error!(logger, "Failed to generate an on-chain tx with fee ({} sat/kw) was less than the floor ({} sat/kw)",
1124 fee_rate, FEERATE_FLOOR_SATS_PER_KW);
1127 Some((fee, fee_rate as u64))
1131 /// Attempt to propose a bumping fee for a transaction from its spent output's values and predicted
1132 /// weight. If feerates proposed by the fee-estimator have been increasing since last fee-bumping
1133 /// attempt, use them. If we need to force a feerate bump, we manually bump the feerate by 25% of
1134 /// the previous feerate. If a feerate bump did happen, we also verify that those bumping heuristics
1135 /// respect BIP125 rules 3) and 4) and if required adjust the new fee to meet the RBF policy
1137 fn feerate_bump<F: Deref, L: Logger>(
1138 predicted_weight: u64, input_amounts: u64, previous_feerate: u64, feerate_strategy: &FeerateStrategy,
1139 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L,
1140 ) -> Option<(u64, u64)>
1142 F::Target: FeeEstimator,
1144 // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
1145 let (new_fee, new_feerate) = if let Some((new_fee, new_feerate)) = compute_fee_from_spent_amounts(input_amounts, predicted_weight, fee_estimator, logger) {
1146 match feerate_strategy {
1147 FeerateStrategy::RetryPrevious => {
1148 let previous_fee = previous_feerate * predicted_weight / 1000;
1149 (previous_fee, previous_feerate)
1151 FeerateStrategy::HighestOfPreviousOrNew => if new_feerate > previous_feerate {
1152 (new_fee, new_feerate)
1154 let previous_fee = previous_feerate * predicted_weight / 1000;
1155 (previous_fee, previous_feerate)
1157 FeerateStrategy::ForceBump => if new_feerate > previous_feerate {
1158 (new_fee, new_feerate)
1160 // ...else just increase the previous feerate by 25% (because that's a nice number)
1161 let bumped_feerate = previous_feerate + (previous_feerate / 4);
1162 let bumped_fee = bumped_feerate * predicted_weight / 1000;
1163 if input_amounts <= bumped_fee {
1164 log_warn!(logger, "Can't 25% bump new claiming tx, amount {} is too small", input_amounts);
1167 (bumped_fee, bumped_feerate)
1171 log_warn!(logger, "Can't new-estimation bump new claiming tx, amount {} is too small", input_amounts);
1175 // Our feerates should never decrease. If it hasn't changed though, we just need to
1176 // rebroadcast/re-sign the previous claim.
1177 debug_assert!(new_feerate >= previous_feerate);
1178 if new_feerate == previous_feerate {
1179 return Some((new_fee, new_feerate));
1182 let previous_fee = previous_feerate * predicted_weight / 1000;
1183 let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * predicted_weight / 1000;
1184 // BIP 125 Opt-in Full Replace-by-Fee Signaling
1185 // * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
1186 // * 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.
1187 let new_fee = if new_fee < previous_fee + min_relay_fee {
1188 new_fee + previous_fee + min_relay_fee - new_fee
1192 Some((new_fee, new_fee * 1000 / predicted_weight))
1197 use crate::chain::package::{CounterpartyOfferedHTLCOutput, CounterpartyReceivedHTLCOutput, HolderHTLCOutput, PackageTemplate, PackageSolvingData, RevokedOutput, WEIGHT_REVOKED_OUTPUT, weight_offered_htlc, weight_received_htlc};
1198 use crate::chain::Txid;
1199 use crate::ln::chan_utils::HTLCOutputInCommitment;
1200 use crate::ln::types::{PaymentPreimage, PaymentHash};
1201 use crate::ln::channel_keys::{DelayedPaymentBasepoint, HtlcBasepoint};
1203 use bitcoin::amount::Amount;
1204 use bitcoin::blockdata::constants::WITNESS_SCALE_FACTOR;
1205 use bitcoin::blockdata::script::ScriptBuf;
1206 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
1208 use bitcoin::hashes::hex::FromHex;
1210 use bitcoin::secp256k1::{PublicKey,SecretKey};
1211 use bitcoin::secp256k1::Secp256k1;
1212 use crate::ln::features::ChannelTypeFeatures;
1214 use std::str::FromStr;
1216 macro_rules! dumb_revk_output {
1217 ($secp_ctx: expr, $is_counterparty_balance_on_anchors: expr) => {
1219 let dumb_scalar = SecretKey::from_slice(&<Vec<u8>>::from_hex("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
1220 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
1221 PackageSolvingData::RevokedOutput(RevokedOutput::build(dumb_point, DelayedPaymentBasepoint::from(dumb_point), HtlcBasepoint::from(dumb_point), dumb_scalar, Amount::ZERO, 0, $is_counterparty_balance_on_anchors))
1226 macro_rules! dumb_counterparty_output {
1227 ($secp_ctx: expr, $amt: expr, $opt_anchors: expr) => {
1229 let dumb_scalar = SecretKey::from_slice(&<Vec<u8>>::from_hex("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
1230 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
1231 let hash = PaymentHash([1; 32]);
1232 let htlc = HTLCOutputInCommitment { offered: true, amount_msat: $amt, cltv_expiry: 0, payment_hash: hash, transaction_output_index: None };
1233 PackageSolvingData::CounterpartyReceivedHTLCOutput(CounterpartyReceivedHTLCOutput::build(dumb_point, DelayedPaymentBasepoint::from(dumb_point), HtlcBasepoint::from(dumb_point), htlc, $opt_anchors))
1238 macro_rules! dumb_counterparty_offered_output {
1239 ($secp_ctx: expr, $amt: expr, $opt_anchors: expr) => {
1241 let dumb_scalar = SecretKey::from_slice(&<Vec<u8>>::from_hex("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
1242 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
1243 let hash = PaymentHash([1; 32]);
1244 let preimage = PaymentPreimage([2;32]);
1245 let htlc = HTLCOutputInCommitment { offered: false, amount_msat: $amt, cltv_expiry: 1000, payment_hash: hash, transaction_output_index: None };
1246 PackageSolvingData::CounterpartyOfferedHTLCOutput(CounterpartyOfferedHTLCOutput::build(dumb_point, DelayedPaymentBasepoint::from(dumb_point), HtlcBasepoint::from(dumb_point), preimage, htlc, $opt_anchors))
1251 macro_rules! dumb_htlc_output {
1254 let preimage = PaymentPreimage([2;32]);
1255 PackageSolvingData::HolderHTLCOutput(HolderHTLCOutput::build_accepted(preimage, 0, ChannelTypeFeatures::only_static_remote_key()))
1262 fn test_package_differing_heights() {
1263 let txid = Txid::from_str("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1264 let secp_ctx = Secp256k1::new();
1265 let revk_outp = dumb_revk_output!(secp_ctx, false);
1267 let mut package_one_hundred = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, 100);
1268 let package_two_hundred = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, 200);
1269 package_one_hundred.merge_package(package_two_hundred);
1274 fn test_package_untractable_merge_to() {
1275 let txid = Txid::from_str("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1276 let secp_ctx = Secp256k1::new();
1277 let revk_outp = dumb_revk_output!(secp_ctx, false);
1278 let htlc_outp = dumb_htlc_output!();
1280 let mut untractable_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, 100);
1281 let malleable_package = PackageTemplate::build_package(txid, 1, htlc_outp.clone(), 1000, 100);
1282 untractable_package.merge_package(malleable_package);
1287 fn test_package_untractable_merge_from() {
1288 let txid = Txid::from_str("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1289 let secp_ctx = Secp256k1::new();
1290 let htlc_outp = dumb_htlc_output!();
1291 let revk_outp = dumb_revk_output!(secp_ctx, false);
1293 let mut malleable_package = PackageTemplate::build_package(txid, 0, htlc_outp.clone(), 1000, 100);
1294 let untractable_package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, 100);
1295 malleable_package.merge_package(untractable_package);
1300 fn test_package_noaggregation_to() {
1301 let txid = Txid::from_str("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1302 let secp_ctx = Secp256k1::new();
1303 let revk_outp = dumb_revk_output!(secp_ctx, false);
1304 let revk_outp_counterparty_balance = dumb_revk_output!(secp_ctx, true);
1306 let mut noaggregation_package = PackageTemplate::build_package(txid, 0, revk_outp_counterparty_balance.clone(), 1000, 100);
1307 let aggregation_package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, 100);
1308 noaggregation_package.merge_package(aggregation_package);
1313 fn test_package_noaggregation_from() {
1314 let txid = Txid::from_str("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1315 let secp_ctx = Secp256k1::new();
1316 let revk_outp = dumb_revk_output!(secp_ctx, false);
1317 let revk_outp_counterparty_balance = dumb_revk_output!(secp_ctx, true);
1319 let mut aggregation_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, 100);
1320 let noaggregation_package = PackageTemplate::build_package(txid, 1, revk_outp_counterparty_balance.clone(), 1000, 100);
1321 aggregation_package.merge_package(noaggregation_package);
1326 fn test_package_empty() {
1327 let txid = Txid::from_str("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1328 let secp_ctx = Secp256k1::new();
1329 let revk_outp = dumb_revk_output!(secp_ctx, false);
1331 let mut empty_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, 100);
1332 empty_package.inputs = vec![];
1333 let package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, 100);
1334 empty_package.merge_package(package);
1339 fn test_package_differing_categories() {
1340 let txid = Txid::from_str("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1341 let secp_ctx = Secp256k1::new();
1342 let revk_outp = dumb_revk_output!(secp_ctx, false);
1343 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 0, ChannelTypeFeatures::only_static_remote_key());
1345 let mut revoked_package = PackageTemplate::build_package(txid, 0, revk_outp, 1000, 100);
1346 let counterparty_package = PackageTemplate::build_package(txid, 1, counterparty_outp, 1000, 100);
1347 revoked_package.merge_package(counterparty_package);
1351 fn test_package_split_malleable() {
1352 let txid = Txid::from_str("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1353 let secp_ctx = Secp256k1::new();
1354 let revk_outp_one = dumb_revk_output!(secp_ctx, false);
1355 let revk_outp_two = dumb_revk_output!(secp_ctx, false);
1356 let revk_outp_three = dumb_revk_output!(secp_ctx, false);
1358 let mut package_one = PackageTemplate::build_package(txid, 0, revk_outp_one, 1000, 100);
1359 let package_two = PackageTemplate::build_package(txid, 1, revk_outp_two, 1000, 100);
1360 let package_three = PackageTemplate::build_package(txid, 2, revk_outp_three, 1000, 100);
1362 package_one.merge_package(package_two);
1363 package_one.merge_package(package_three);
1364 assert_eq!(package_one.outpoints().len(), 3);
1366 if let Some(split_package) = package_one.split_package(&BitcoinOutPoint { txid, vout: 1 }) {
1367 // Packages attributes should be identical
1368 assert!(split_package.is_malleable());
1369 assert_eq!(split_package.soonest_conf_deadline, package_one.soonest_conf_deadline);
1370 assert_eq!(split_package.aggregable, package_one.aggregable);
1371 assert_eq!(split_package.feerate_previous, package_one.feerate_previous);
1372 assert_eq!(split_package.height_timer, package_one.height_timer);
1373 assert_eq!(split_package.height_original, package_one.height_original);
1374 } else { panic!(); }
1375 assert_eq!(package_one.outpoints().len(), 2);
1379 fn test_package_split_untractable() {
1380 let txid = Txid::from_str("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1381 let htlc_outp_one = dumb_htlc_output!();
1383 let mut package_one = PackageTemplate::build_package(txid, 0, htlc_outp_one, 1000, 100);
1384 let ret_split = package_one.split_package(&BitcoinOutPoint { txid, vout: 0});
1385 assert!(ret_split.is_none());
1389 fn test_package_timer() {
1390 let txid = Txid::from_str("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1391 let secp_ctx = Secp256k1::new();
1392 let revk_outp = dumb_revk_output!(secp_ctx, false);
1394 let mut package = PackageTemplate::build_package(txid, 0, revk_outp, 1000, 100);
1395 assert_eq!(package.timer(), 100);
1396 package.set_timer(101);
1397 assert_eq!(package.timer(), 101);
1401 fn test_package_amounts() {
1402 let txid = Txid::from_str("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1403 let secp_ctx = Secp256k1::new();
1404 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 1_000_000, ChannelTypeFeatures::only_static_remote_key());
1406 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, 100);
1407 assert_eq!(package.package_amount(), 1000);
1411 fn test_package_weight() {
1412 let txid = Txid::from_str("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1413 let secp_ctx = Secp256k1::new();
1415 // (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)
1416 let weight_sans_output = (4 + 4 + 1 + 36 + 4 + 1 + 1 + 8 + 1) * WITNESS_SCALE_FACTOR as u64 + 2;
1419 let revk_outp = dumb_revk_output!(secp_ctx, false);
1420 let package = PackageTemplate::build_package(txid, 0, revk_outp, 0, 100);
1421 assert_eq!(package.package_weight(&ScriptBuf::new()), weight_sans_output + WEIGHT_REVOKED_OUTPUT);
1425 for channel_type_features in [ChannelTypeFeatures::only_static_remote_key(), ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies()].iter() {
1426 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 1_000_000, channel_type_features.clone());
1427 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, 100);
1428 assert_eq!(package.package_weight(&ScriptBuf::new()), weight_sans_output + weight_received_htlc(channel_type_features));
1433 for channel_type_features in [ChannelTypeFeatures::only_static_remote_key(), ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies()].iter() {
1434 let counterparty_outp = dumb_counterparty_offered_output!(secp_ctx, 1_000_000, channel_type_features.clone());
1435 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, 100);
1436 assert_eq!(package.package_weight(&ScriptBuf::new()), weight_sans_output + weight_offered_htlc(channel_type_features));