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;
29 use crate::chain::onchaintx::{ExternalHTLCClaim, OnchainTxHandler};
30 use crate::util::logger::Logger;
31 use crate::util::ser::{Readable, Writer, Writeable, RequiredWrapper};
34 use crate::prelude::*;
36 use core::convert::TryInto;
39 use bitcoin::{PackedLockTime, Sequence, Witness};
40 use crate::ln::features::ChannelTypeFeatures;
42 use super::chaininterface::LowerBoundedFeeEstimator;
44 const MAX_ALLOC_SIZE: usize = 64*1024;
47 pub(crate) fn weight_revoked_offered_htlc(channel_type_features: &ChannelTypeFeatures) -> u64 {
48 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
49 const WEIGHT_REVOKED_OFFERED_HTLC: u64 = 1 + 1 + 73 + 1 + 33 + 1 + 133;
50 const WEIGHT_REVOKED_OFFERED_HTLC_ANCHORS: u64 = WEIGHT_REVOKED_OFFERED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
51 if channel_type_features.supports_anchors_zero_fee_htlc_tx() { WEIGHT_REVOKED_OFFERED_HTLC_ANCHORS } else { WEIGHT_REVOKED_OFFERED_HTLC }
54 pub(crate) fn weight_revoked_received_htlc(channel_type_features: &ChannelTypeFeatures) -> u64 {
55 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
56 const WEIGHT_REVOKED_RECEIVED_HTLC: u64 = 1 + 1 + 73 + 1 + 33 + 1 + 139;
57 const WEIGHT_REVOKED_RECEIVED_HTLC_ANCHORS: u64 = WEIGHT_REVOKED_RECEIVED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
58 if channel_type_features.supports_anchors_zero_fee_htlc_tx() { WEIGHT_REVOKED_RECEIVED_HTLC_ANCHORS } else { WEIGHT_REVOKED_RECEIVED_HTLC }
61 pub(crate) fn weight_offered_htlc(channel_type_features: &ChannelTypeFeatures) -> u64 {
62 // number_of_witness_elements + sig_length + counterpartyhtlc_sig + preimage_length + preimage + witness_script_length + witness_script
63 const WEIGHT_OFFERED_HTLC: u64 = 1 + 1 + 73 + 1 + 32 + 1 + 133;
64 const WEIGHT_OFFERED_HTLC_ANCHORS: u64 = WEIGHT_OFFERED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
65 if channel_type_features.supports_anchors_zero_fee_htlc_tx() { WEIGHT_OFFERED_HTLC_ANCHORS } else { WEIGHT_OFFERED_HTLC }
68 pub(crate) fn weight_received_htlc(channel_type_features: &ChannelTypeFeatures) -> u64 {
69 // number_of_witness_elements + sig_length + counterpartyhtlc_sig + empty_vec_length + empty_vec + witness_script_length + witness_script
70 const WEIGHT_RECEIVED_HTLC: u64 = 1 + 1 + 73 + 1 + 1 + 1 + 139;
71 const WEIGHT_RECEIVED_HTLC_ANCHORS: u64 = WEIGHT_RECEIVED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
72 if channel_type_features.supports_anchors_zero_fee_htlc_tx() { WEIGHT_RECEIVED_HTLC_ANCHORS } else { WEIGHT_RECEIVED_HTLC }
75 /// Verifies deserializable channel type features
76 pub(crate) fn verify_channel_type_features(channel_type_features: &Option<ChannelTypeFeatures>, additional_permitted_features: Option<&ChannelTypeFeatures>) -> Result<(), DecodeError> {
77 if let Some(features) = channel_type_features.as_ref() {
78 if features.requires_unknown_bits() {
79 return Err(DecodeError::UnknownRequiredFeature);
82 let mut supported_feature_set = ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies();
83 supported_feature_set.set_scid_privacy_required();
84 supported_feature_set.set_zero_conf_required();
86 // allow the passing of an additional necessary permitted flag
87 if let Some(additional_permitted_features) = additional_permitted_features {
88 supported_feature_set |= additional_permitted_features;
91 if !features.is_subset(&supported_feature_set) {
92 return Err(DecodeError::UnknownRequiredFeature);
99 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
100 pub(crate) const WEIGHT_REVOKED_OUTPUT: u64 = 1 + 1 + 73 + 1 + 1 + 1 + 77;
102 /// Height delay at which transactions are fee-bumped/rebroadcasted with a low priority.
103 const LOW_FREQUENCY_BUMP_INTERVAL: u32 = 15;
104 /// Height delay at which transactions are fee-bumped/rebroadcasted with a middle priority.
105 const MIDDLE_FREQUENCY_BUMP_INTERVAL: u32 = 3;
106 /// Height delay at which transactions are fee-bumped/rebroadcasted with a high priority.
107 const HIGH_FREQUENCY_BUMP_INTERVAL: u32 = 1;
109 /// A struct to describe a revoked output and corresponding information to generate a solving
110 /// witness spending a commitment `to_local` output or a second-stage HTLC transaction output.
112 /// CSV and pubkeys are used as part of a witnessScript redeeming a balance output, amount is used
113 /// as part of the signature hash and revocation secret to generate a satisfying witness.
114 #[derive(Clone, PartialEq, Eq)]
115 pub(crate) struct RevokedOutput {
116 per_commitment_point: PublicKey,
117 counterparty_delayed_payment_base_key: PublicKey,
118 counterparty_htlc_base_key: PublicKey,
119 per_commitment_key: SecretKey,
122 on_counterparty_tx_csv: u16,
123 is_counterparty_balance_on_anchors: Option<()>,
127 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 {
129 per_commitment_point,
130 counterparty_delayed_payment_base_key,
131 counterparty_htlc_base_key,
133 weight: WEIGHT_REVOKED_OUTPUT,
135 on_counterparty_tx_csv,
136 is_counterparty_balance_on_anchors: if is_counterparty_balance_on_anchors { Some(()) } else { None }
141 impl_writeable_tlv_based!(RevokedOutput, {
142 (0, per_commitment_point, required),
143 (2, counterparty_delayed_payment_base_key, required),
144 (4, counterparty_htlc_base_key, required),
145 (6, per_commitment_key, required),
146 (8, weight, required),
147 (10, amount, required),
148 (12, on_counterparty_tx_csv, required),
149 (14, is_counterparty_balance_on_anchors, option)
152 /// A struct to describe a revoked offered output and corresponding information to generate a
155 /// HTLCOuputInCommitment (hash timelock, direction) and pubkeys are used to generate a suitable
158 /// CSV is used as part of a witnessScript redeeming a balance output, amount is used as part
159 /// of the signature hash and revocation secret to generate a satisfying witness.
160 #[derive(Clone, PartialEq, Eq)]
161 pub(crate) struct RevokedHTLCOutput {
162 per_commitment_point: PublicKey,
163 counterparty_delayed_payment_base_key: PublicKey,
164 counterparty_htlc_base_key: PublicKey,
165 per_commitment_key: SecretKey,
168 htlc: HTLCOutputInCommitment,
171 impl RevokedHTLCOutput {
172 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 {
173 let weight = if htlc.offered { weight_revoked_offered_htlc(channel_type_features) } else { weight_revoked_received_htlc(channel_type_features) };
175 per_commitment_point,
176 counterparty_delayed_payment_base_key,
177 counterparty_htlc_base_key,
186 impl_writeable_tlv_based!(RevokedHTLCOutput, {
187 (0, per_commitment_point, required),
188 (2, counterparty_delayed_payment_base_key, required),
189 (4, counterparty_htlc_base_key, required),
190 (6, per_commitment_key, required),
191 (8, weight, required),
192 (10, amount, required),
193 (12, htlc, required),
196 /// A struct to describe a HTLC output on a counterparty commitment transaction.
198 /// HTLCOutputInCommitment (hash, timelock, directon) and pubkeys are used to generate a suitable
201 /// The preimage is used as part of the witness.
203 /// Note that on upgrades, some features of existing outputs may be missed.
204 #[derive(Clone, PartialEq, Eq)]
205 pub(crate) struct CounterpartyOfferedHTLCOutput {
206 per_commitment_point: PublicKey,
207 counterparty_delayed_payment_base_key: PublicKey,
208 counterparty_htlc_base_key: PublicKey,
209 preimage: PaymentPreimage,
210 htlc: HTLCOutputInCommitment,
211 channel_type_features: ChannelTypeFeatures,
214 impl CounterpartyOfferedHTLCOutput {
215 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 {
216 CounterpartyOfferedHTLCOutput {
217 per_commitment_point,
218 counterparty_delayed_payment_base_key,
219 counterparty_htlc_base_key,
222 channel_type_features,
227 impl Writeable for CounterpartyOfferedHTLCOutput {
228 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
229 let legacy_deserialization_prevention_marker = chan_utils::legacy_deserialization_prevention_marker_for_channel_type_features(&self.channel_type_features);
230 write_tlv_fields!(writer, {
231 (0, self.per_commitment_point, required),
232 (2, self.counterparty_delayed_payment_base_key, required),
233 (4, self.counterparty_htlc_base_key, required),
234 (6, self.preimage, required),
235 (8, self.htlc, required),
236 (10, legacy_deserialization_prevention_marker, option),
237 (11, self.channel_type_features, required),
243 impl Readable for CounterpartyOfferedHTLCOutput {
244 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
245 let mut per_commitment_point = RequiredWrapper(None);
246 let mut counterparty_delayed_payment_base_key = RequiredWrapper(None);
247 let mut counterparty_htlc_base_key = RequiredWrapper(None);
248 let mut preimage = RequiredWrapper(None);
249 let mut htlc = RequiredWrapper(None);
250 let mut _legacy_deserialization_prevention_marker: Option<()> = None;
251 let mut channel_type_features = None;
253 read_tlv_fields!(reader, {
254 (0, per_commitment_point, required),
255 (2, counterparty_delayed_payment_base_key, required),
256 (4, counterparty_htlc_base_key, required),
257 (6, preimage, required),
259 (10, _legacy_deserialization_prevention_marker, option),
260 (11, channel_type_features, option),
263 verify_channel_type_features(&channel_type_features, None)?;
266 per_commitment_point: per_commitment_point.0.unwrap(),
267 counterparty_delayed_payment_base_key: counterparty_delayed_payment_base_key.0.unwrap(),
268 counterparty_htlc_base_key: counterparty_htlc_base_key.0.unwrap(),
269 preimage: preimage.0.unwrap(),
270 htlc: htlc.0.unwrap(),
271 channel_type_features: channel_type_features.unwrap_or(ChannelTypeFeatures::only_static_remote_key())
276 /// A struct to describe a HTLC output on a counterparty commitment transaction.
278 /// HTLCOutputInCommitment (hash, timelock, directon) and pubkeys are used to generate a suitable
281 /// Note that on upgrades, some features of existing outputs may be missed.
282 #[derive(Clone, PartialEq, Eq)]
283 pub(crate) struct CounterpartyReceivedHTLCOutput {
284 per_commitment_point: PublicKey,
285 counterparty_delayed_payment_base_key: PublicKey,
286 counterparty_htlc_base_key: PublicKey,
287 htlc: HTLCOutputInCommitment,
288 channel_type_features: ChannelTypeFeatures,
291 impl CounterpartyReceivedHTLCOutput {
292 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 {
293 CounterpartyReceivedHTLCOutput {
294 per_commitment_point,
295 counterparty_delayed_payment_base_key,
296 counterparty_htlc_base_key,
298 channel_type_features
303 impl Writeable for CounterpartyReceivedHTLCOutput {
304 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
305 let legacy_deserialization_prevention_marker = chan_utils::legacy_deserialization_prevention_marker_for_channel_type_features(&self.channel_type_features);
306 write_tlv_fields!(writer, {
307 (0, self.per_commitment_point, required),
308 (2, self.counterparty_delayed_payment_base_key, required),
309 (4, self.counterparty_htlc_base_key, required),
310 (6, self.htlc, required),
311 (8, legacy_deserialization_prevention_marker, option),
312 (9, self.channel_type_features, required),
318 impl Readable for CounterpartyReceivedHTLCOutput {
319 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
320 let mut per_commitment_point = RequiredWrapper(None);
321 let mut counterparty_delayed_payment_base_key = RequiredWrapper(None);
322 let mut counterparty_htlc_base_key = RequiredWrapper(None);
323 let mut htlc = RequiredWrapper(None);
324 let mut _legacy_deserialization_prevention_marker: Option<()> = None;
325 let mut channel_type_features = None;
327 read_tlv_fields!(reader, {
328 (0, per_commitment_point, required),
329 (2, counterparty_delayed_payment_base_key, required),
330 (4, counterparty_htlc_base_key, required),
332 (8, _legacy_deserialization_prevention_marker, option),
333 (9, channel_type_features, option),
336 verify_channel_type_features(&channel_type_features, None)?;
339 per_commitment_point: per_commitment_point.0.unwrap(),
340 counterparty_delayed_payment_base_key: counterparty_delayed_payment_base_key.0.unwrap(),
341 counterparty_htlc_base_key: counterparty_htlc_base_key.0.unwrap(),
342 htlc: htlc.0.unwrap(),
343 channel_type_features: channel_type_features.unwrap_or(ChannelTypeFeatures::only_static_remote_key())
348 /// A struct to describe a HTLC output on holder commitment transaction.
350 /// Either offered or received, the amount is always used as part of the bip143 sighash.
351 /// Preimage is only included as part of the witness in former case.
353 /// Note that on upgrades, some features of existing outputs may be missed.
354 #[derive(Clone, PartialEq, Eq)]
355 pub(crate) struct HolderHTLCOutput {
356 preimage: Option<PaymentPreimage>,
358 /// Defaults to 0 for HTLC-Success transactions, which have no expiry
360 channel_type_features: ChannelTypeFeatures,
363 impl HolderHTLCOutput {
364 pub(crate) fn build_offered(amount_msat: u64, cltv_expiry: u32, channel_type_features: ChannelTypeFeatures) -> Self {
369 channel_type_features,
373 pub(crate) fn build_accepted(preimage: PaymentPreimage, amount_msat: u64, channel_type_features: ChannelTypeFeatures) -> Self {
375 preimage: Some(preimage),
378 channel_type_features,
383 impl Writeable for HolderHTLCOutput {
384 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
385 let legacy_deserialization_prevention_marker = chan_utils::legacy_deserialization_prevention_marker_for_channel_type_features(&self.channel_type_features);
386 write_tlv_fields!(writer, {
387 (0, self.amount_msat, required),
388 (2, self.cltv_expiry, required),
389 (4, self.preimage, option),
390 (6, legacy_deserialization_prevention_marker, option),
391 (7, self.channel_type_features, required),
397 impl Readable for HolderHTLCOutput {
398 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
399 let mut amount_msat = RequiredWrapper(None);
400 let mut cltv_expiry = RequiredWrapper(None);
401 let mut preimage = None;
402 let mut _legacy_deserialization_prevention_marker: Option<()> = None;
403 let mut channel_type_features = None;
405 read_tlv_fields!(reader, {
406 (0, amount_msat, required),
407 (2, cltv_expiry, required),
408 (4, preimage, option),
409 (6, _legacy_deserialization_prevention_marker, option),
410 (7, channel_type_features, option),
413 verify_channel_type_features(&channel_type_features, None)?;
416 amount_msat: amount_msat.0.unwrap(),
417 cltv_expiry: cltv_expiry.0.unwrap(),
419 channel_type_features: channel_type_features.unwrap_or(ChannelTypeFeatures::only_static_remote_key())
424 /// A struct to describe the channel output on the funding transaction.
426 /// witnessScript is used as part of the witness redeeming the funding utxo.
428 /// Note that on upgrades, some features of existing outputs may be missed.
429 #[derive(Clone, PartialEq, Eq)]
430 pub(crate) struct HolderFundingOutput {
431 funding_redeemscript: Script,
432 pub(crate) funding_amount: Option<u64>,
433 channel_type_features: ChannelTypeFeatures,
437 impl HolderFundingOutput {
438 pub(crate) fn build(funding_redeemscript: Script, funding_amount: u64, channel_type_features: ChannelTypeFeatures) -> Self {
439 HolderFundingOutput {
440 funding_redeemscript,
441 funding_amount: Some(funding_amount),
442 channel_type_features,
447 impl Writeable for HolderFundingOutput {
448 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
449 let legacy_deserialization_prevention_marker = chan_utils::legacy_deserialization_prevention_marker_for_channel_type_features(&self.channel_type_features);
450 write_tlv_fields!(writer, {
451 (0, self.funding_redeemscript, required),
452 (1, self.channel_type_features, required),
453 (2, legacy_deserialization_prevention_marker, option),
454 (3, self.funding_amount, option),
460 impl Readable for HolderFundingOutput {
461 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
462 let mut funding_redeemscript = RequiredWrapper(None);
463 let mut _legacy_deserialization_prevention_marker: Option<()> = None;
464 let mut channel_type_features = None;
465 let mut funding_amount = None;
467 read_tlv_fields!(reader, {
468 (0, funding_redeemscript, required),
469 (1, channel_type_features, option),
470 (2, _legacy_deserialization_prevention_marker, option),
471 (3, funding_amount, option)
474 verify_channel_type_features(&channel_type_features, None)?;
477 funding_redeemscript: funding_redeemscript.0.unwrap(),
478 channel_type_features: channel_type_features.unwrap_or(ChannelTypeFeatures::only_static_remote_key()),
484 /// A wrapper encapsulating all in-protocol differing outputs types.
486 /// The generic API offers access to an outputs common attributes or allow transformation such as
487 /// finalizing an input claiming the output.
488 #[derive(Clone, PartialEq, Eq)]
489 pub(crate) enum PackageSolvingData {
490 RevokedOutput(RevokedOutput),
491 RevokedHTLCOutput(RevokedHTLCOutput),
492 CounterpartyOfferedHTLCOutput(CounterpartyOfferedHTLCOutput),
493 CounterpartyReceivedHTLCOutput(CounterpartyReceivedHTLCOutput),
494 HolderHTLCOutput(HolderHTLCOutput),
495 HolderFundingOutput(HolderFundingOutput),
498 impl PackageSolvingData {
499 fn amount(&self) -> u64 {
500 let amt = match self {
501 PackageSolvingData::RevokedOutput(ref outp) => outp.amount,
502 PackageSolvingData::RevokedHTLCOutput(ref outp) => outp.amount,
503 PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => outp.htlc.amount_msat / 1000,
504 PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => outp.htlc.amount_msat / 1000,
505 PackageSolvingData::HolderHTLCOutput(ref outp) => {
506 debug_assert!(outp.channel_type_features.supports_anchors_zero_fee_htlc_tx());
507 outp.amount_msat / 1000
509 PackageSolvingData::HolderFundingOutput(ref outp) => {
510 debug_assert!(outp.channel_type_features.supports_anchors_zero_fee_htlc_tx());
511 outp.funding_amount.unwrap()
516 fn weight(&self) -> usize {
518 PackageSolvingData::RevokedOutput(ref outp) => outp.weight as usize,
519 PackageSolvingData::RevokedHTLCOutput(ref outp) => outp.weight as usize,
520 PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => weight_offered_htlc(&outp.channel_type_features) as usize,
521 PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => weight_received_htlc(&outp.channel_type_features) as usize,
522 PackageSolvingData::HolderHTLCOutput(ref outp) => {
523 debug_assert!(outp.channel_type_features.supports_anchors_zero_fee_htlc_tx());
524 if outp.preimage.is_none() {
525 weight_offered_htlc(&outp.channel_type_features) as usize
527 weight_received_htlc(&outp.channel_type_features) as usize
530 // Since HolderFundingOutput maps to an untractable package that is already signed, its
531 // weight can be determined from the transaction itself.
532 PackageSolvingData::HolderFundingOutput(..) => unreachable!(),
535 fn is_compatible(&self, input: &PackageSolvingData) -> bool {
537 PackageSolvingData::RevokedOutput(..) => {
539 PackageSolvingData::RevokedHTLCOutput(..) => { true },
540 PackageSolvingData::RevokedOutput(..) => { true },
544 PackageSolvingData::RevokedHTLCOutput(..) => {
546 PackageSolvingData::RevokedOutput(..) => { true },
547 PackageSolvingData::RevokedHTLCOutput(..) => { true },
551 _ => { mem::discriminant(self) == mem::discriminant(&input) }
554 fn finalize_input<Signer: WriteableEcdsaChannelSigner>(&self, bumped_tx: &mut Transaction, i: usize, onchain_handler: &mut OnchainTxHandler<Signer>) -> bool {
556 PackageSolvingData::RevokedOutput(ref outp) => {
557 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);
558 let witness_script = chan_utils::get_revokeable_redeemscript(&chan_keys.revocation_key, outp.on_counterparty_tx_csv, &chan_keys.broadcaster_delayed_payment_key);
559 //TODO: should we panic on signer failure ?
560 if let Ok(sig) = onchain_handler.signer.sign_justice_revoked_output(&bumped_tx, i, outp.amount, &outp.per_commitment_key, &onchain_handler.secp_ctx) {
561 let mut ser_sig = sig.serialize_der().to_vec();
562 ser_sig.push(EcdsaSighashType::All as u8);
563 bumped_tx.input[i].witness.push(ser_sig);
564 bumped_tx.input[i].witness.push(vec!(1));
565 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
566 } else { return false; }
568 PackageSolvingData::RevokedHTLCOutput(ref outp) => {
569 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);
570 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);
571 //TODO: should we panic on signer failure ?
572 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) {
573 let mut ser_sig = sig.serialize_der().to_vec();
574 ser_sig.push(EcdsaSighashType::All as u8);
575 bumped_tx.input[i].witness.push(ser_sig);
576 bumped_tx.input[i].witness.push(chan_keys.revocation_key.clone().serialize().to_vec());
577 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
578 } else { return false; }
580 PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => {
581 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);
582 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);
584 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) {
585 let mut ser_sig = sig.serialize_der().to_vec();
586 ser_sig.push(EcdsaSighashType::All as u8);
587 bumped_tx.input[i].witness.push(ser_sig);
588 bumped_tx.input[i].witness.push(outp.preimage.0.to_vec());
589 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
592 PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => {
593 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);
594 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);
596 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) {
597 let mut ser_sig = sig.serialize_der().to_vec();
598 ser_sig.push(EcdsaSighashType::All as u8);
599 bumped_tx.input[i].witness.push(ser_sig);
600 // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
601 bumped_tx.input[i].witness.push(vec![]);
602 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
605 _ => { panic!("API Error!"); }
609 fn get_finalized_tx<Signer: WriteableEcdsaChannelSigner>(&self, outpoint: &BitcoinOutPoint, onchain_handler: &mut OnchainTxHandler<Signer>) -> Option<Transaction> {
611 PackageSolvingData::HolderHTLCOutput(ref outp) => {
612 debug_assert!(!outp.channel_type_features.supports_anchors_zero_fee_htlc_tx());
613 return onchain_handler.get_fully_signed_htlc_tx(outpoint, &outp.preimage);
615 PackageSolvingData::HolderFundingOutput(ref outp) => {
616 return Some(onchain_handler.get_fully_signed_holder_tx(&outp.funding_redeemscript));
618 _ => { panic!("API Error!"); }
621 fn absolute_tx_timelock(&self, current_height: u32) -> u32 {
622 // We use `current_height` as our default locktime to discourage fee sniping and because
623 // transactions with it always propagate.
624 let absolute_timelock = match self {
625 PackageSolvingData::RevokedOutput(_) => current_height,
626 PackageSolvingData::RevokedHTLCOutput(_) => current_height,
627 PackageSolvingData::CounterpartyOfferedHTLCOutput(_) => current_height,
628 PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => cmp::max(outp.htlc.cltv_expiry, current_height),
629 // HTLC timeout/success transactions rely on a fixed timelock due to the counterparty's
631 PackageSolvingData::HolderHTLCOutput(ref outp) => {
632 if outp.preimage.is_some() {
633 debug_assert_eq!(outp.cltv_expiry, 0);
637 PackageSolvingData::HolderFundingOutput(_) => current_height,
642 fn map_output_type_flags(&self) -> (PackageMalleability, bool) {
643 // Post-anchor, aggregation of outputs of different types is unsafe. See https://github.com/lightning/bolts/pull/803.
644 let (malleability, aggregable) = match self {
645 PackageSolvingData::RevokedOutput(RevokedOutput { is_counterparty_balance_on_anchors: Some(()), .. }) => { (PackageMalleability::Malleable, false) },
646 PackageSolvingData::RevokedOutput(RevokedOutput { is_counterparty_balance_on_anchors: None, .. }) => { (PackageMalleability::Malleable, true) },
647 PackageSolvingData::RevokedHTLCOutput(..) => { (PackageMalleability::Malleable, true) },
648 PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => { (PackageMalleability::Malleable, true) },
649 PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => { (PackageMalleability::Malleable, false) },
650 PackageSolvingData::HolderHTLCOutput(ref outp) => if outp.channel_type_features.supports_anchors_zero_fee_htlc_tx() {
651 (PackageMalleability::Malleable, outp.preimage.is_some())
653 (PackageMalleability::Untractable, false)
655 PackageSolvingData::HolderFundingOutput(..) => { (PackageMalleability::Untractable, false) },
657 (malleability, aggregable)
661 impl_writeable_tlv_based_enum!(PackageSolvingData, ;
663 (1, RevokedHTLCOutput),
664 (2, CounterpartyOfferedHTLCOutput),
665 (3, CounterpartyReceivedHTLCOutput),
666 (4, HolderHTLCOutput),
667 (5, HolderFundingOutput),
670 /// A malleable package might be aggregated with other packages to save on fees.
671 /// A untractable package has been counter-signed and aggregable will break cached counterparty signatures.
672 #[derive(Clone, PartialEq, Eq)]
673 pub(crate) enum PackageMalleability {
678 /// A structure to describe a package content that is generated by ChannelMonitor and
679 /// used by OnchainTxHandler to generate and broadcast transactions settling onchain claims.
681 /// A package is defined as one or more transactions claiming onchain outputs in reaction
682 /// to confirmation of a channel transaction. Those packages might be aggregated to save on
683 /// fees, if satisfaction of outputs's witnessScript let's us do so.
685 /// As packages are time-sensitive, we fee-bump and rebroadcast them at scheduled intervals.
686 /// Failing to confirm a package translate as a loss of funds for the user.
687 #[derive(Clone, PartialEq, Eq)]
688 pub struct PackageTemplate {
689 // List of onchain outputs and solving data to generate satisfying witnesses.
690 inputs: Vec<(BitcoinOutPoint, PackageSolvingData)>,
691 // Packages are deemed as malleable if we have local knwoledge of at least one set of
692 // private keys yielding a satisfying witnesses. Malleability implies that we can aggregate
693 // packages among them to save on fees or rely on RBF to bump their feerates.
694 // Untractable packages have been counter-signed and thus imply that we can't aggregate
695 // them without breaking signatures. Fee-bumping strategy will also rely on CPFP.
696 malleability: PackageMalleability,
697 // Block height after which the earlier-output belonging to this package is mature for a
698 // competing claim by the counterparty. As our chain tip becomes nearer from the timelock,
699 // the fee-bumping frequency will increase. See `OnchainTxHandler::get_height_timer`.
700 soonest_conf_deadline: u32,
701 // Determines if this package can be aggregated.
702 // Timelocked outputs belonging to the same transaction might have differing
703 // satisfying heights. Picking up the later height among the output set would be a valid
704 // aggregable strategy but it comes with at least 2 trade-offs :
705 // * earlier-output fund are going to take longer to come back
706 // * CLTV delta backing up a corresponding HTLC on an upstream channel could be swallowed
707 // by the requirement of the later-output part of the set
708 // For now, we mark such timelocked outputs as non-aggregable, though we might introduce
709 // smarter aggregable strategy in the future.
711 // Cache of package feerate committed at previous (re)broadcast. If bumping resources
712 // (either claimed output value or external utxo), it will keep increasing until holder
713 // or counterparty successful claim.
714 feerate_previous: u64,
715 // Cache of next height at which fee-bumping and rebroadcast will be attempted. In
716 // the future, we might abstract it to an observed mempool fluctuation.
718 // Confirmation height of the claimed outputs set transaction. In case of reorg reaching
719 // it, we wipe out and forget the package.
720 height_original: u32,
723 impl PackageTemplate {
724 pub(crate) fn is_malleable(&self) -> bool {
725 self.malleability == PackageMalleability::Malleable
727 pub(crate) fn timelock(&self) -> u32 {
728 self.soonest_conf_deadline
730 pub(crate) fn aggregable(&self) -> bool {
733 pub(crate) fn previous_feerate(&self) -> u64 {
734 self.feerate_previous
736 pub(crate) fn set_feerate(&mut self, new_feerate: u64) {
737 self.feerate_previous = new_feerate;
739 pub(crate) fn timer(&self) -> u32 {
742 pub(crate) fn set_timer(&mut self, new_timer: u32) {
743 self.height_timer = new_timer;
745 pub(crate) fn outpoints(&self) -> Vec<&BitcoinOutPoint> {
746 self.inputs.iter().map(|(o, _)| o).collect()
748 pub(crate) fn inputs(&self) -> impl ExactSizeIterator<Item = &PackageSolvingData> {
749 self.inputs.iter().map(|(_, i)| i)
751 pub(crate) fn split_package(&mut self, split_outp: &BitcoinOutPoint) -> Option<PackageTemplate> {
752 match self.malleability {
753 PackageMalleability::Malleable => {
754 let mut split_package = None;
755 let timelock = self.soonest_conf_deadline;
756 let aggregable = self.aggregable;
757 let feerate_previous = self.feerate_previous;
758 let height_timer = self.height_timer;
759 let height_original = self.height_original;
760 self.inputs.retain(|outp| {
761 if *split_outp == outp.0 {
762 split_package = Some(PackageTemplate {
763 inputs: vec![(outp.0, outp.1.clone())],
764 malleability: PackageMalleability::Malleable,
765 soonest_conf_deadline: timelock,
775 return split_package;
778 // Note, we may try to split on remote transaction for
779 // which we don't have a competing one (HTLC-Success before
780 // timelock expiration). This explain we don't panic!
781 // We should refactor OnchainTxHandler::block_connected to
782 // only test equality on competing claims.
787 pub(crate) fn merge_package(&mut self, mut merge_from: PackageTemplate) {
788 assert_eq!(self.height_original, merge_from.height_original);
789 if self.malleability == PackageMalleability::Untractable || merge_from.malleability == PackageMalleability::Untractable {
790 panic!("Merging template on untractable packages");
792 if !self.aggregable || !merge_from.aggregable {
793 panic!("Merging non aggregatable packages");
795 if let Some((_, lead_input)) = self.inputs.first() {
796 for (_, v) in merge_from.inputs.iter() {
797 if !lead_input.is_compatible(v) { panic!("Merging outputs from differing types !"); }
799 } else { panic!("Merging template on an empty package"); }
800 for (k, v) in merge_from.inputs.drain(..) {
801 self.inputs.push((k, v));
803 //TODO: verify coverage and sanity?
804 if self.soonest_conf_deadline > merge_from.soonest_conf_deadline {
805 self.soonest_conf_deadline = merge_from.soonest_conf_deadline;
807 if self.feerate_previous > merge_from.feerate_previous {
808 self.feerate_previous = merge_from.feerate_previous;
810 self.height_timer = cmp::min(self.height_timer, merge_from.height_timer);
812 /// Gets the amount of all outptus being spent by this package, only valid for malleable
814 pub(crate) fn package_amount(&self) -> u64 {
816 for (_, outp) in self.inputs.iter() {
817 amounts += outp.amount();
821 pub(crate) fn package_locktime(&self, current_height: u32) -> u32 {
822 let locktime = self.inputs.iter().map(|(_, outp)| outp.absolute_tx_timelock(current_height))
823 .max().expect("There must always be at least one output to spend in a PackageTemplate");
825 // If we ever try to aggregate a `HolderHTLCOutput`s with another output type, we'll likely
826 // end up with an incorrect transaction locktime since the counterparty has included it in
827 // its HTLC signature. This should never happen unless we decide to aggregate outputs across
828 // different channel commitments.
829 #[cfg(debug_assertions)] {
830 if self.inputs.iter().any(|(_, outp)|
831 if let PackageSolvingData::HolderHTLCOutput(outp) = outp {
832 outp.preimage.is_some()
837 debug_assert_eq!(locktime, 0);
839 for timeout_htlc_expiry in self.inputs.iter().filter_map(|(_, outp)|
840 if let PackageSolvingData::HolderHTLCOutput(outp) = outp {
841 if outp.preimage.is_none() {
842 Some(outp.cltv_expiry)
846 debug_assert_eq!(locktime, timeout_htlc_expiry);
852 pub(crate) fn package_weight(&self, destination_script: &Script) -> usize {
853 let mut inputs_weight = 0;
854 let mut witnesses_weight = 2; // count segwit flags
855 for (_, outp) in self.inputs.iter() {
856 // previous_out_point: 36 bytes ; var_int: 1 byte ; sequence: 4 bytes
857 inputs_weight += 41 * WITNESS_SCALE_FACTOR;
858 witnesses_weight += outp.weight();
860 // version: 4 bytes ; count_tx_in: 1 byte ; count_tx_out: 1 byte ; lock_time: 4 bytes
861 let transaction_weight = 10 * WITNESS_SCALE_FACTOR;
862 // value: 8 bytes ; var_int: 1 byte ; pk_script: `destination_script.len()`
863 let output_weight = (8 + 1 + destination_script.len()) * WITNESS_SCALE_FACTOR;
864 inputs_weight + witnesses_weight + transaction_weight + output_weight
866 pub(crate) fn construct_malleable_package_with_external_funding<Signer: WriteableEcdsaChannelSigner>(
867 &self, onchain_handler: &mut OnchainTxHandler<Signer>,
868 ) -> Option<Vec<ExternalHTLCClaim>> {
869 debug_assert!(self.requires_external_funding());
870 let mut htlcs: Option<Vec<ExternalHTLCClaim>> = None;
871 for (previous_output, input) in &self.inputs {
873 PackageSolvingData::HolderHTLCOutput(ref outp) => {
874 debug_assert!(outp.channel_type_features.supports_anchors_zero_fee_htlc_tx());
875 onchain_handler.generate_external_htlc_claim(&previous_output, &outp.preimage).map(|htlc| {
876 htlcs.get_or_insert_with(|| Vec::with_capacity(self.inputs.len())).push(htlc);
879 _ => debug_assert!(false, "Expected HolderHTLCOutputs to not be aggregated with other input types"),
884 pub(crate) fn finalize_malleable_package<L: Deref, Signer: WriteableEcdsaChannelSigner>(
885 &self, current_height: u32, onchain_handler: &mut OnchainTxHandler<Signer>, value: u64,
886 destination_script: Script, logger: &L
887 ) -> Option<Transaction> where L::Target: Logger {
888 debug_assert!(self.is_malleable());
889 let mut bumped_tx = Transaction {
891 lock_time: PackedLockTime(self.package_locktime(current_height)),
894 script_pubkey: destination_script,
898 for (outpoint, _) in self.inputs.iter() {
899 bumped_tx.input.push(TxIn {
900 previous_output: *outpoint,
901 script_sig: Script::new(),
902 sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
903 witness: Witness::new(),
906 for (i, (outpoint, out)) in self.inputs.iter().enumerate() {
907 log_debug!(logger, "Adding claiming input for outpoint {}:{}", outpoint.txid, outpoint.vout);
908 if !out.finalize_input(&mut bumped_tx, i, onchain_handler) { return None; }
910 log_debug!(logger, "Finalized transaction {} ready to broadcast", bumped_tx.txid());
913 pub(crate) fn finalize_untractable_package<L: Deref, Signer: WriteableEcdsaChannelSigner>(
914 &self, onchain_handler: &mut OnchainTxHandler<Signer>, logger: &L,
915 ) -> Option<Transaction> where L::Target: Logger {
916 debug_assert!(!self.is_malleable());
917 if let Some((outpoint, outp)) = self.inputs.first() {
918 if let Some(final_tx) = outp.get_finalized_tx(outpoint, onchain_handler) {
919 log_debug!(logger, "Adding claiming input for outpoint {}:{}", outpoint.txid, outpoint.vout);
920 log_debug!(logger, "Finalized transaction {} ready to broadcast", final_tx.txid());
921 return Some(final_tx);
924 } else { panic!("API Error: Package must not be inputs empty"); }
926 /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
927 /// 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
928 /// height that once reached we should generate a new bumped "version" of the claim tx to be sure that we safely claim outputs before
929 /// that our counterparty can do so. If timelock expires soon, height timer is going to be scaled down in consequence to increase
930 /// frequency of the bump and so increase our bets of success.
931 pub(crate) fn get_height_timer(&self, current_height: u32) -> u32 {
932 if self.soonest_conf_deadline <= current_height + MIDDLE_FREQUENCY_BUMP_INTERVAL {
933 return current_height + HIGH_FREQUENCY_BUMP_INTERVAL
934 } else if self.soonest_conf_deadline - current_height <= LOW_FREQUENCY_BUMP_INTERVAL {
935 return current_height + MIDDLE_FREQUENCY_BUMP_INTERVAL
937 current_height + LOW_FREQUENCY_BUMP_INTERVAL
940 /// Returns value in satoshis to be included as package outgoing output amount and feerate
941 /// which was used to generate the value. Will not return less than `dust_limit_sats` for the
943 pub(crate) fn compute_package_output<F: Deref, L: Deref>(
944 &self, predicted_weight: usize, dust_limit_sats: u64, force_feerate_bump: bool,
945 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L,
946 ) -> Option<(u64, u64)>
948 F::Target: FeeEstimator,
951 debug_assert!(self.malleability == PackageMalleability::Malleable, "The package output is fixed for non-malleable packages");
952 let input_amounts = self.package_amount();
953 assert!(dust_limit_sats as i64 > 0, "Output script must be broadcastable/have a 'real' dust limit.");
954 // If old feerate is 0, first iteration of this claim, use normal fee calculation
955 if self.feerate_previous != 0 {
956 if let Some((new_fee, feerate)) = feerate_bump(
957 predicted_weight, input_amounts, self.feerate_previous, force_feerate_bump,
958 fee_estimator, logger,
960 return Some((cmp::max(input_amounts as i64 - new_fee as i64, dust_limit_sats as i64) as u64, feerate));
963 if let Some((new_fee, feerate)) = compute_fee_from_spent_amounts(input_amounts, predicted_weight, fee_estimator, logger) {
964 return Some((cmp::max(input_amounts as i64 - new_fee as i64, dust_limit_sats as i64) as u64, feerate));
970 /// Computes a feerate based on the given confirmation target. If a previous feerate was used,
971 /// the new feerate is below it, and `force_feerate_bump` is set, we'll use a 25% increase of
972 /// the previous feerate instead of the new feerate.
973 pub(crate) fn compute_package_feerate<F: Deref>(
974 &self, fee_estimator: &LowerBoundedFeeEstimator<F>, conf_target: ConfirmationTarget,
975 force_feerate_bump: bool,
976 ) -> u32 where F::Target: FeeEstimator {
977 let feerate_estimate = fee_estimator.bounded_sat_per_1000_weight(conf_target);
978 if self.feerate_previous != 0 {
979 // Use the new fee estimate if it's higher than the one previously used.
980 if feerate_estimate as u64 > self.feerate_previous {
982 } else if !force_feerate_bump {
983 self.feerate_previous.try_into().unwrap_or(u32::max_value())
985 // Our fee estimate has decreased, but our transaction remains unconfirmed after
986 // using our previous fee estimate. This may point to an unreliable fee estimator,
987 // so we choose to bump our previous feerate by 25%, making sure we don't use a
988 // lower feerate or overpay by a large margin by limiting it to 5x the new fee
990 let previous_feerate = self.feerate_previous.try_into().unwrap_or(u32::max_value());
991 let mut new_feerate = previous_feerate.saturating_add(previous_feerate / 4);
992 if new_feerate > feerate_estimate * 5 {
993 new_feerate = cmp::max(feerate_estimate * 5, previous_feerate);
1002 /// Determines whether a package contains an input which must have additional external inputs
1003 /// attached to help the spending transaction reach confirmation.
1004 pub(crate) fn requires_external_funding(&self) -> bool {
1005 self.inputs.iter().find(|input| match input.1 {
1006 PackageSolvingData::HolderFundingOutput(ref outp) => outp.channel_type_features.supports_anchors_zero_fee_htlc_tx(),
1007 PackageSolvingData::HolderHTLCOutput(ref outp) => outp.channel_type_features.supports_anchors_zero_fee_htlc_tx(),
1012 pub (crate) fn build_package(txid: Txid, vout: u32, input_solving_data: PackageSolvingData, soonest_conf_deadline: u32, height_original: u32) -> Self {
1013 let (malleability, aggregable) = PackageSolvingData::map_output_type_flags(&input_solving_data);
1014 let mut inputs = Vec::with_capacity(1);
1015 inputs.push((BitcoinOutPoint { txid, vout }, input_solving_data));
1019 soonest_conf_deadline,
1021 feerate_previous: 0,
1022 height_timer: height_original,
1028 impl Writeable for PackageTemplate {
1029 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
1030 writer.write_all(&(self.inputs.len() as u64).to_be_bytes())?;
1031 for (ref outpoint, ref rev_outp) in self.inputs.iter() {
1032 outpoint.write(writer)?;
1033 rev_outp.write(writer)?;
1035 write_tlv_fields!(writer, {
1036 (0, self.soonest_conf_deadline, required),
1037 (2, self.feerate_previous, required),
1038 (4, self.height_original, required),
1039 (6, self.height_timer, required)
1045 impl Readable for PackageTemplate {
1046 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
1047 let inputs_count = <u64 as Readable>::read(reader)?;
1048 let mut inputs: Vec<(BitcoinOutPoint, PackageSolvingData)> = Vec::with_capacity(cmp::min(inputs_count as usize, MAX_ALLOC_SIZE / 128));
1049 for _ in 0..inputs_count {
1050 let outpoint = Readable::read(reader)?;
1051 let rev_outp = Readable::read(reader)?;
1052 inputs.push((outpoint, rev_outp));
1054 let (malleability, aggregable) = if let Some((_, lead_input)) = inputs.first() {
1055 PackageSolvingData::map_output_type_flags(&lead_input)
1056 } else { return Err(DecodeError::InvalidValue); };
1057 let mut soonest_conf_deadline = 0;
1058 let mut feerate_previous = 0;
1059 let mut height_timer = None;
1060 let mut height_original = 0;
1061 read_tlv_fields!(reader, {
1062 (0, soonest_conf_deadline, required),
1063 (2, feerate_previous, required),
1064 (4, height_original, required),
1065 (6, height_timer, option),
1067 if height_timer.is_none() {
1068 height_timer = Some(height_original);
1070 Ok(PackageTemplate {
1073 soonest_conf_deadline,
1076 height_timer: height_timer.unwrap(),
1082 /// Attempt to propose a bumping fee for a transaction from its spent output's values and predicted
1083 /// weight. We start with the highest priority feerate returned by the node's fee estimator then
1084 /// fall-back to lower priorities until we have enough value available to suck from.
1086 /// If the proposed fee is less than the available spent output's values, we return the proposed
1087 /// fee and the corresponding updated feerate. If the proposed fee is equal or more than the
1088 /// available spent output's values, we return nothing
1089 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)>
1090 where F::Target: FeeEstimator,
1093 let mut updated_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::HighPriority) as u64;
1094 let mut fee = updated_feerate * (predicted_weight as u64) / 1000;
1095 if input_amounts <= fee {
1096 updated_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal) as u64;
1097 fee = updated_feerate * (predicted_weight as u64) / 1000;
1098 if input_amounts <= fee {
1099 updated_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Background) as u64;
1100 fee = updated_feerate * (predicted_weight as u64) / 1000;
1101 if input_amounts <= fee {
1102 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)",
1103 fee, input_amounts);
1106 log_warn!(logger, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
1108 Some((fee, updated_feerate))
1111 log_warn!(logger, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
1113 Some((fee, updated_feerate))
1116 Some((fee, updated_feerate))
1120 /// Attempt to propose a bumping fee for a transaction from its spent output's values and predicted
1121 /// weight. If feerates proposed by the fee-estimator have been increasing since last fee-bumping
1122 /// attempt, use them. If `force_feerate_bump` is set, we bump the feerate by 25% of the previous
1123 /// feerate, or just use the previous feerate otherwise. If a feerate bump did happen, we also
1124 /// verify that those bumping heuristics respect BIP125 rules 3) and 4) and if required adjust the
1125 /// new fee to meet the RBF policy requirement.
1126 fn feerate_bump<F: Deref, L: Deref>(
1127 predicted_weight: usize, input_amounts: u64, previous_feerate: u64, force_feerate_bump: bool,
1128 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L,
1129 ) -> Option<(u64, u64)>
1131 F::Target: FeeEstimator,
1134 // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
1135 let (new_fee, new_feerate) = if let Some((new_fee, new_feerate)) = compute_fee_from_spent_amounts(input_amounts, predicted_weight, fee_estimator, logger) {
1136 if new_feerate > previous_feerate {
1137 (new_fee, new_feerate)
1138 } else if !force_feerate_bump {
1139 let previous_fee = previous_feerate * (predicted_weight as u64) / 1000;
1140 (previous_fee, previous_feerate)
1142 // ...else just increase the previous feerate by 25% (because that's a nice number)
1143 let bumped_feerate = previous_feerate + (previous_feerate / 4);
1144 let bumped_fee = bumped_feerate * (predicted_weight as u64) / 1000;
1145 if input_amounts <= bumped_fee {
1146 log_warn!(logger, "Can't 25% bump new claiming tx, amount {} is too small", input_amounts);
1149 (bumped_fee, bumped_feerate)
1152 log_warn!(logger, "Can't new-estimation bump new claiming tx, amount {} is too small", input_amounts);
1156 // Our feerates should never decrease. If it hasn't changed though, we just need to
1157 // rebroadcast/re-sign the previous claim.
1158 debug_assert!(new_feerate >= previous_feerate);
1159 if new_feerate == previous_feerate {
1160 return Some((new_fee, new_feerate));
1163 let previous_fee = previous_feerate * (predicted_weight as u64) / 1000;
1164 let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * (predicted_weight as u64) / 1000;
1165 // BIP 125 Opt-in Full Replace-by-Fee Signaling
1166 // * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
1167 // * 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.
1168 let new_fee = if new_fee < previous_fee + min_relay_fee {
1169 new_fee + previous_fee + min_relay_fee - new_fee
1173 Some((new_fee, new_fee * 1000 / (predicted_weight as u64)))
1178 use crate::chain::package::{CounterpartyOfferedHTLCOutput, CounterpartyReceivedHTLCOutput, HolderHTLCOutput, PackageTemplate, PackageSolvingData, RevokedOutput, WEIGHT_REVOKED_OUTPUT, weight_offered_htlc, weight_received_htlc};
1179 use crate::chain::Txid;
1180 use crate::ln::chan_utils::HTLCOutputInCommitment;
1181 use crate::ln::{PaymentPreimage, PaymentHash};
1183 use bitcoin::blockdata::constants::WITNESS_SCALE_FACTOR;
1184 use bitcoin::blockdata::script::Script;
1185 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
1187 use bitcoin::hashes::hex::FromHex;
1189 use bitcoin::secp256k1::{PublicKey,SecretKey};
1190 use bitcoin::secp256k1::Secp256k1;
1191 use crate::ln::features::ChannelTypeFeatures;
1193 macro_rules! dumb_revk_output {
1194 ($secp_ctx: expr, $is_counterparty_balance_on_anchors: expr) => {
1196 let dumb_scalar = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
1197 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
1198 PackageSolvingData::RevokedOutput(RevokedOutput::build(dumb_point, dumb_point, dumb_point, dumb_scalar, 0, 0, $is_counterparty_balance_on_anchors))
1203 macro_rules! dumb_counterparty_output {
1204 ($secp_ctx: expr, $amt: expr, $opt_anchors: expr) => {
1206 let dumb_scalar = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
1207 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
1208 let hash = PaymentHash([1; 32]);
1209 let htlc = HTLCOutputInCommitment { offered: true, amount_msat: $amt, cltv_expiry: 0, payment_hash: hash, transaction_output_index: None };
1210 PackageSolvingData::CounterpartyReceivedHTLCOutput(CounterpartyReceivedHTLCOutput::build(dumb_point, dumb_point, dumb_point, htlc, $opt_anchors))
1215 macro_rules! dumb_counterparty_offered_output {
1216 ($secp_ctx: expr, $amt: expr, $opt_anchors: expr) => {
1218 let dumb_scalar = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
1219 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
1220 let hash = PaymentHash([1; 32]);
1221 let preimage = PaymentPreimage([2;32]);
1222 let htlc = HTLCOutputInCommitment { offered: false, amount_msat: $amt, cltv_expiry: 1000, payment_hash: hash, transaction_output_index: None };
1223 PackageSolvingData::CounterpartyOfferedHTLCOutput(CounterpartyOfferedHTLCOutput::build(dumb_point, dumb_point, dumb_point, preimage, htlc, $opt_anchors))
1228 macro_rules! dumb_htlc_output {
1231 let preimage = PaymentPreimage([2;32]);
1232 PackageSolvingData::HolderHTLCOutput(HolderHTLCOutput::build_accepted(preimage, 0, ChannelTypeFeatures::only_static_remote_key()))
1239 fn test_package_differing_heights() {
1240 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1241 let secp_ctx = Secp256k1::new();
1242 let revk_outp = dumb_revk_output!(secp_ctx, false);
1244 let mut package_one_hundred = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, 100);
1245 let package_two_hundred = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, 200);
1246 package_one_hundred.merge_package(package_two_hundred);
1251 fn test_package_untractable_merge_to() {
1252 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1253 let secp_ctx = Secp256k1::new();
1254 let revk_outp = dumb_revk_output!(secp_ctx, false);
1255 let htlc_outp = dumb_htlc_output!();
1257 let mut untractable_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, 100);
1258 let malleable_package = PackageTemplate::build_package(txid, 1, htlc_outp.clone(), 1000, 100);
1259 untractable_package.merge_package(malleable_package);
1264 fn test_package_untractable_merge_from() {
1265 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1266 let secp_ctx = Secp256k1::new();
1267 let htlc_outp = dumb_htlc_output!();
1268 let revk_outp = dumb_revk_output!(secp_ctx, false);
1270 let mut malleable_package = PackageTemplate::build_package(txid, 0, htlc_outp.clone(), 1000, 100);
1271 let untractable_package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, 100);
1272 malleable_package.merge_package(untractable_package);
1277 fn test_package_noaggregation_to() {
1278 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1279 let secp_ctx = Secp256k1::new();
1280 let revk_outp = dumb_revk_output!(secp_ctx, false);
1281 let revk_outp_counterparty_balance = dumb_revk_output!(secp_ctx, true);
1283 let mut noaggregation_package = PackageTemplate::build_package(txid, 0, revk_outp_counterparty_balance.clone(), 1000, 100);
1284 let aggregation_package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, 100);
1285 noaggregation_package.merge_package(aggregation_package);
1290 fn test_package_noaggregation_from() {
1291 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1292 let secp_ctx = Secp256k1::new();
1293 let revk_outp = dumb_revk_output!(secp_ctx, false);
1294 let revk_outp_counterparty_balance = dumb_revk_output!(secp_ctx, true);
1296 let mut aggregation_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, 100);
1297 let noaggregation_package = PackageTemplate::build_package(txid, 1, revk_outp_counterparty_balance.clone(), 1000, 100);
1298 aggregation_package.merge_package(noaggregation_package);
1303 fn test_package_empty() {
1304 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1305 let secp_ctx = Secp256k1::new();
1306 let revk_outp = dumb_revk_output!(secp_ctx, false);
1308 let mut empty_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, 100);
1309 empty_package.inputs = vec![];
1310 let package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, 100);
1311 empty_package.merge_package(package);
1316 fn test_package_differing_categories() {
1317 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1318 let secp_ctx = Secp256k1::new();
1319 let revk_outp = dumb_revk_output!(secp_ctx, false);
1320 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 0, ChannelTypeFeatures::only_static_remote_key());
1322 let mut revoked_package = PackageTemplate::build_package(txid, 0, revk_outp, 1000, 100);
1323 let counterparty_package = PackageTemplate::build_package(txid, 1, counterparty_outp, 1000, 100);
1324 revoked_package.merge_package(counterparty_package);
1328 fn test_package_split_malleable() {
1329 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1330 let secp_ctx = Secp256k1::new();
1331 let revk_outp_one = dumb_revk_output!(secp_ctx, false);
1332 let revk_outp_two = dumb_revk_output!(secp_ctx, false);
1333 let revk_outp_three = dumb_revk_output!(secp_ctx, false);
1335 let mut package_one = PackageTemplate::build_package(txid, 0, revk_outp_one, 1000, 100);
1336 let package_two = PackageTemplate::build_package(txid, 1, revk_outp_two, 1000, 100);
1337 let package_three = PackageTemplate::build_package(txid, 2, revk_outp_three, 1000, 100);
1339 package_one.merge_package(package_two);
1340 package_one.merge_package(package_three);
1341 assert_eq!(package_one.outpoints().len(), 3);
1343 if let Some(split_package) = package_one.split_package(&BitcoinOutPoint { txid, vout: 1 }) {
1344 // Packages attributes should be identical
1345 assert!(split_package.is_malleable());
1346 assert_eq!(split_package.soonest_conf_deadline, package_one.soonest_conf_deadline);
1347 assert_eq!(split_package.aggregable, package_one.aggregable);
1348 assert_eq!(split_package.feerate_previous, package_one.feerate_previous);
1349 assert_eq!(split_package.height_timer, package_one.height_timer);
1350 assert_eq!(split_package.height_original, package_one.height_original);
1351 } else { panic!(); }
1352 assert_eq!(package_one.outpoints().len(), 2);
1356 fn test_package_split_untractable() {
1357 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1358 let htlc_outp_one = dumb_htlc_output!();
1360 let mut package_one = PackageTemplate::build_package(txid, 0, htlc_outp_one, 1000, 100);
1361 let ret_split = package_one.split_package(&BitcoinOutPoint { txid, vout: 0});
1362 assert!(ret_split.is_none());
1366 fn test_package_timer() {
1367 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1368 let secp_ctx = Secp256k1::new();
1369 let revk_outp = dumb_revk_output!(secp_ctx, false);
1371 let mut package = PackageTemplate::build_package(txid, 0, revk_outp, 1000, 100);
1372 assert_eq!(package.timer(), 100);
1373 package.set_timer(101);
1374 assert_eq!(package.timer(), 101);
1378 fn test_package_amounts() {
1379 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1380 let secp_ctx = Secp256k1::new();
1381 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 1_000_000, ChannelTypeFeatures::only_static_remote_key());
1383 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, 100);
1384 assert_eq!(package.package_amount(), 1000);
1388 fn test_package_weight() {
1389 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1390 let secp_ctx = Secp256k1::new();
1392 // (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)
1393 let weight_sans_output = (4 + 4 + 1 + 36 + 4 + 1 + 1 + 8 + 1) * WITNESS_SCALE_FACTOR + 2;
1396 let revk_outp = dumb_revk_output!(secp_ctx, false);
1397 let package = PackageTemplate::build_package(txid, 0, revk_outp, 0, 100);
1398 assert_eq!(package.package_weight(&Script::new()), weight_sans_output + WEIGHT_REVOKED_OUTPUT as usize);
1402 for channel_type_features in [ChannelTypeFeatures::only_static_remote_key(), ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies()].iter() {
1403 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 1_000_000, channel_type_features.clone());
1404 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, 100);
1405 assert_eq!(package.package_weight(&Script::new()), weight_sans_output + weight_received_htlc(channel_type_features) as usize);
1410 for channel_type_features in [ChannelTypeFeatures::only_static_remote_key(), ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies()].iter() {
1411 let counterparty_outp = dumb_counterparty_offered_output!(secp_ctx, 1_000_000, channel_type_features.clone());
1412 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, 100);
1413 assert_eq!(package.package_weight(&Script::new()), weight_sans_output + weight_offered_htlc(channel_type_features) as usize);