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tankyleotankyleo
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Reorg return values of ChannelContext::build_commitment_transaction
We choose to include in `CommitmentStats` only fields that will be calculated or constructed by transaction builders. The other fields are created by channel, and placed in a new struct we call `CommitmentData`.
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-44
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+77
-44
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‎lightning/src/ln/channel.rs‎

Lines changed: 77 additions & 44 deletions
Original file line numberDiff line numberDiff line change
@@ -877,15 +877,20 @@ struct HTLCStats {
877877
on_holder_tx_outbound_holding_cell_htlcs_count: u32, // dust HTLCs *non*-included
878878
}
879879

880-
/// An enum gathering stats on commitment transaction, either local or remote.
881-
struct CommitmentStats<'a> {
880+
/// A struct gathering data on a commitment, either local or remote.
881+
struct CommitmentData<'a> {
882+
stats: CommitmentStats,
883+
htlcs_included: Vec<(HTLCOutputInCommitment, Option<&'a HTLCSource>)>, // the list of HTLCs (dust HTLCs *included*) which were not ignored when building the transaction
884+
outbound_htlc_preimages: Vec<PaymentPreimage>, // preimages for successful offered HTLCs since last commitment
885+
inbound_htlc_preimages: Vec<PaymentPreimage>, // preimages for successful received HTLCs since last commitment
886+
}
887+
888+
/// A struct gathering stats on a commitment transaction, either local or remote.
889+
struct CommitmentStats {
882890
tx: CommitmentTransaction, // the transaction info
883891
total_fee_sat: u64, // the total fee included in the transaction
884-
htlcs_included: Vec<(HTLCOutputInCommitment, Option<&'a HTLCSource>)>, // the list of HTLCs (dust HTLCs *included*) which were not ignored when building the transaction
885892
local_balance_before_fee_msat: u64, // local balance before fees *not* considering dust limits
886893
remote_balance_before_fee_msat: u64, // remote balance before fees *not* considering dust limits
887-
outbound_htlc_preimages: Vec<PaymentPreimage>, // preimages for successful offered HTLCs since last commitment
888-
inbound_htlc_preimages: Vec<PaymentPreimage>, // preimages for successful received HTLCs since last commitment
889894
}
890895

891896
/// Used when calculating whether we or the remote can afford an additional HTLC.
@@ -2043,7 +2048,10 @@ trait InitialRemoteCommitmentReceiver<SP: Deref> where SP::Target: SignerProvide
20432048
) -> Result<CommitmentTransaction, ChannelError> where L::Target: Logger {
20442049
let funding_script = self.funding().get_funding_redeemscript();
20452050

2046-
let initial_commitment_tx = self.context().build_commitment_transaction(self.funding(), holder_commitment_point.transaction_number(), &holder_commitment_point.current_point(), true, false, logger).tx;
2051+
let commitment_data = self.context().build_commitment_transaction(self.funding(),
2052+
holder_commitment_point.transaction_number(), &holder_commitment_point.current_point(),
2053+
true, false, logger);
2054+
let initial_commitment_tx = commitment_data.stats.tx;
20472055
let trusted_tx = initial_commitment_tx.trust();
20482056
let initial_commitment_bitcoin_tx = trusted_tx.built_transaction();
20492057
let sighash = initial_commitment_bitcoin_tx.get_sighash_all(&funding_script, self.funding().get_value_satoshis());
@@ -2080,7 +2088,10 @@ trait InitialRemoteCommitmentReceiver<SP: Deref> where SP::Target: SignerProvide
20802088
}
20812089
};
20822090
let context = self.context();
2083-
let counterparty_initial_commitment_tx = context.build_commitment_transaction(self.funding(), context.cur_counterparty_commitment_transaction_number, &context.counterparty_cur_commitment_point.unwrap(), false, false, logger).tx;
2091+
let commitment_data = context.build_commitment_transaction(self.funding(),
2092+
context.cur_counterparty_commitment_transaction_number,
2093+
&context.counterparty_cur_commitment_point.unwrap(), false, false, logger);
2094+
let counterparty_initial_commitment_tx = commitment_data.stats.tx;
20842095
let counterparty_trusted_tx = counterparty_initial_commitment_tx.trust();
20852096
let counterparty_initial_bitcoin_tx = counterparty_trusted_tx.built_transaction();
20862097

@@ -3477,9 +3488,11 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider {
34773488
{
34783489
let funding_script = funding.get_funding_redeemscript();
34793490

3480-
let commitment_stats = self.build_commitment_transaction(funding, holder_commitment_point.transaction_number(), &holder_commitment_point.current_point(), true, false, logger);
3491+
let commitment_data = self.build_commitment_transaction(funding,
3492+
holder_commitment_point.transaction_number(), &holder_commitment_point.current_point(),
3493+
true, false, logger);
34813494
let commitment_txid = {
3482-
let trusted_tx = commitment_stats.tx.trust();
3495+
let trusted_tx = commitment_data.stats.tx.trust();
34833496
let bitcoin_tx = trusted_tx.built_transaction();
34843497
let sighash = bitcoin_tx.get_sighash_all(&funding_script, funding.get_value_satoshis());
34853498

@@ -3492,7 +3505,7 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider {
34923505
}
34933506
bitcoin_tx.txid
34943507
};
3495-
let mut htlcs_cloned: Vec<_> = commitment_stats.htlcs_included.iter().map(|htlc| (htlc.0.clone(), htlc.1.map(|h| h.clone()))).collect();
3508+
let mut htlcs_cloned: Vec<_> = commitment_data.htlcs_included.iter().map(|htlc| (htlc.0.clone(), htlc.1.map(|h| h.clone()))).collect();
34963509

34973510
// If our counterparty updated the channel fee in this commitment transaction, check that
34983511
// they can actually afford the new fee now.
@@ -3502,7 +3515,7 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider {
35023515
if update_fee {
35033516
debug_assert!(!funding.is_outbound());
35043517
let counterparty_reserve_we_require_msat = funding.holder_selected_channel_reserve_satoshis * 1000;
3505-
if commitment_stats.remote_balance_before_fee_msat < commitment_stats.total_fee_sat * 1000 + counterparty_reserve_we_require_msat {
3518+
if commitment_data.stats.remote_balance_before_fee_msat < commitment_data.stats.total_fee_sat * 1000 + counterparty_reserve_we_require_msat {
35063519
return Err(ChannelError::close("Funding remote cannot afford proposed new fee".to_owned()));
35073520
}
35083521
}
@@ -3518,14 +3531,14 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider {
35183531
&& info.next_holder_htlc_id == self.next_holder_htlc_id
35193532
&& info.next_counterparty_htlc_id == self.next_counterparty_htlc_id
35203533
&& info.feerate == self.feerate_per_kw {
3521-
assert_eq!(commitment_stats.total_fee_sat, info.fee / 1000);
3534+
assert_eq!(commitment_data.stats.total_fee_sat, info.fee / 1000);
35223535
}
35233536
}
35243537
}
35253538
}
35263539

3527-
if msg.htlc_signatures.len() != commitment_stats.tx.htlcs().len() {
3528-
return Err(ChannelError::close(format!("Got wrong number of HTLC signatures ({}) from remote. It must be {}", msg.htlc_signatures.len(), commitment_stats.tx.htlcs().len())));
3540+
if msg.htlc_signatures.len() != commitment_data.stats.tx.htlcs().len() {
3541+
return Err(ChannelError::close(format!("Got wrong number of HTLC signatures ({}) from remote. It must be {}", msg.htlc_signatures.len(), commitment_data.stats.tx.htlcs().len())));
35293542
}
35303543

35313544
// Up to LDK 0.0.115, HTLC information was required to be duplicated in the
@@ -3545,10 +3558,10 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider {
35453558

35463559
let mut nondust_htlc_sources = Vec::with_capacity(htlcs_cloned.len());
35473560
let mut htlcs_and_sigs = Vec::with_capacity(htlcs_cloned.len());
3548-
let holder_keys = commitment_stats.tx.trust().keys();
3561+
let holder_keys = commitment_data.stats.tx.trust().keys();
35493562
for (idx, (htlc, mut source_opt)) in htlcs_cloned.drain(..).enumerate() {
35503563
if let Some(_) = htlc.transaction_output_index {
3551-
let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_stats.tx.feerate_per_kw(),
3564+
let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_data.stats.tx.feerate_per_kw(),
35523565
funding.get_counterparty_selected_contest_delay().unwrap(), &htlc, &self.channel_type,
35533566
&holder_keys.broadcaster_delayed_payment_key, &holder_keys.revocation_key);
35543567

@@ -3576,14 +3589,14 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider {
35763589
}
35773590

35783591
let holder_commitment_tx = HolderCommitmentTransaction::new(
3579-
commitment_stats.tx,
3592+
commitment_data.stats.tx,
35803593
msg.signature,
35813594
msg.htlc_signatures.clone(),
35823595
&funding.get_holder_pubkeys().funding_pubkey,
35833596
funding.counterparty_funding_pubkey()
35843597
);
35853598

3586-
self.holder_signer.as_ref().validate_holder_commitment(&holder_commitment_tx, commitment_stats.outbound_htlc_preimages)
3599+
self.holder_signer.as_ref().validate_holder_commitment(&holder_commitment_tx, commitment_data.outbound_htlc_preimages)
35873600
.map_err(|_| ChannelError::close("Failed to validate our commitment".to_owned()))?;
35883601

35893602
Ok(LatestHolderCommitmentTXInfo {
@@ -3607,7 +3620,7 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider {
36073620
/// generated by the peer which proposed adding the HTLCs, and thus we need to understand both
36083621
/// which peer generated this transaction and "to whom" this transaction flows.
36093622
#[inline]
3610-
fn build_commitment_transaction<L: Deref>(&self, funding: &FundingScope, commitment_number: u64, per_commitment_point: &PublicKey, local: bool, generated_by_local: bool, logger: &L) -> CommitmentStats
3623+
fn build_commitment_transaction<L: Deref>(&self, funding: &FundingScope, commitment_number: u64, per_commitment_point: &PublicKey, local: bool, generated_by_local: bool, logger: &L) -> CommitmentData
36113624
where L::Target: Logger
36123625
{
36133626
let mut included_dust_htlcs: Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)> = Vec::new();
@@ -3823,12 +3836,16 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider {
38233836
htlcs_included.sort_unstable_by_key(|h| h.0.transaction_output_index.unwrap());
38243837
htlcs_included.append(&mut included_dust_htlcs);
38253838

3826-
CommitmentStats {
3839+
let stats = CommitmentStats {
38273840
tx,
38283841
total_fee_sat,
3829-
htlcs_included,
38303842
local_balance_before_fee_msat: value_to_self_msat,
38313843
remote_balance_before_fee_msat: value_to_remote_msat,
3844+
};
3845+
3846+
CommitmentData {
3847+
stats,
3848+
htlcs_included,
38323849
inbound_htlc_preimages,
38333850
outbound_htlc_preimages,
38343851
}
@@ -4616,8 +4633,10 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider {
46164633
SP::Target: SignerProvider,
46174634
L::Target: Logger
46184635
{
4619-
let counterparty_initial_commitment_tx = self.build_commitment_transaction(
4620-
funding, self.cur_counterparty_commitment_transaction_number, &self.counterparty_cur_commitment_point.unwrap(), false, false, logger).tx;
4636+
let commitment_data = self.build_commitment_transaction(funding,
4637+
self.cur_counterparty_commitment_transaction_number,
4638+
&self.counterparty_cur_commitment_point.unwrap(), false, false, logger);
4639+
let counterparty_initial_commitment_tx = commitment_data.stats.tx;
46214640
match self.holder_signer {
46224641
// TODO (taproot|arik): move match into calling method for Taproot
46234642
ChannelSignerType::Ecdsa(ref ecdsa) => {
@@ -6330,9 +6349,11 @@ impl<SP: Deref> FundedChannel<SP> where
63306349
// Before proposing a feerate update, check that we can actually afford the new fee.
63316350
let dust_exposure_limiting_feerate = self.context.get_dust_exposure_limiting_feerate(&fee_estimator);
63326351
let htlc_stats = self.context.get_pending_htlc_stats(Some(feerate_per_kw), dust_exposure_limiting_feerate);
6333-
let commitment_stats = self.context.build_commitment_transaction(&self.funding, self.holder_commitment_point.transaction_number(), &self.holder_commitment_point.current_point(), true, true, logger);
6334-
let buffer_fee_msat = commit_tx_fee_sat(feerate_per_kw, commitment_stats.tx.htlcs().len() + htlc_stats.on_holder_tx_outbound_holding_cell_htlcs_count as usize + CONCURRENT_INBOUND_HTLC_FEE_BUFFER as usize, self.context.get_channel_type()) * 1000;
6335-
let holder_balance_msat = commitment_stats.local_balance_before_fee_msat - htlc_stats.outbound_holding_cell_msat;
6352+
let commitment_data = self.context.build_commitment_transaction(&self.funding,
6353+
self.holder_commitment_point.transaction_number(),
6354+
&self.holder_commitment_point.current_point(), true, true, logger);
6355+
let buffer_fee_msat = commit_tx_fee_sat(feerate_per_kw, commitment_data.stats.tx.htlcs().len() + htlc_stats.on_holder_tx_outbound_holding_cell_htlcs_count as usize + CONCURRENT_INBOUND_HTLC_FEE_BUFFER as usize, self.context.get_channel_type()) * 1000;
6356+
let holder_balance_msat = commitment_data.stats.local_balance_before_fee_msat - htlc_stats.outbound_holding_cell_msat;
63366357
if holder_balance_msat < buffer_fee_msat + self.funding.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000 {
63376358
//TODO: auto-close after a number of failures?
63386359
log_debug!(logger, "Cannot afford to send new feerate at {}", feerate_per_kw);
@@ -6643,7 +6664,10 @@ impl<SP: Deref> FundedChannel<SP> where
66436664
self.holder_commitment_point.try_resolve_pending(&self.context.holder_signer, &self.context.secp_ctx, logger);
66446665
}
66456666
let funding_signed = if self.context.signer_pending_funding && !self.funding.is_outbound() {
6646-
let counterparty_initial_commitment_tx = self.context.build_commitment_transaction(&self.funding, self.context.cur_counterparty_commitment_transaction_number + 1, &self.context.counterparty_cur_commitment_point.unwrap(), false, false, logger).tx;
6667+
let commitment_data = self.context.build_commitment_transaction(&self.funding,
6668+
self.context.cur_counterparty_commitment_transaction_number + 1,
6669+
&self.context.counterparty_cur_commitment_point.unwrap(), false, false, logger);
6670+
let counterparty_initial_commitment_tx = commitment_data.stats.tx;
66476671
self.context.get_funding_signed_msg(&self.funding.channel_transaction_parameters, logger, counterparty_initial_commitment_tx)
66486672
} else { None };
66496673
// Provide a `channel_ready` message if we need to, but only if we're _not_ still pending
@@ -8716,8 +8740,10 @@ impl<SP: Deref> FundedChannel<SP> where
87168740
-> (Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)>, CommitmentTransaction)
87178741
where L::Target: Logger
87188742
{
8719-
let commitment_stats = self.context.build_commitment_transaction(&self.funding, self.context.cur_counterparty_commitment_transaction_number, &self.context.counterparty_cur_commitment_point.unwrap(), false, true, logger);
8720-
let counterparty_commitment_tx = commitment_stats.tx;
8743+
let commitment_data = self.context.build_commitment_transaction(&self.funding,
8744+
self.context.cur_counterparty_commitment_transaction_number,
8745+
&self.context.counterparty_cur_commitment_point.unwrap(), false, true, logger);
8746+
let counterparty_commitment_tx = commitment_data.stats.tx;
87218747

87228748
#[cfg(any(test, fuzzing))]
87238749
{
@@ -8737,7 +8763,7 @@ impl<SP: Deref> FundedChannel<SP> where
87378763
}
87388764
}
87398765

8740-
(commitment_stats.htlcs_included, counterparty_commitment_tx)
8766+
(commitment_data.htlcs_included, counterparty_commitment_tx)
87418767
}
87428768

87438769
/// Only fails in case of signer rejection. Used for channel_reestablish commitment_signed
@@ -8747,8 +8773,10 @@ impl<SP: Deref> FundedChannel<SP> where
87478773
#[cfg(any(test, fuzzing))]
87488774
self.build_commitment_no_state_update(logger);
87498775

8750-
let commitment_stats = self.context.build_commitment_transaction(&self.funding, self.context.cur_counterparty_commitment_transaction_number, &self.context.counterparty_cur_commitment_point.unwrap(), false, true, logger);
8751-
let counterparty_commitment_txid = commitment_stats.tx.trust().txid();
8776+
let commitment_data = self.context.build_commitment_transaction(&self.funding,
8777+
self.context.cur_counterparty_commitment_transaction_number,
8778+
&self.context.counterparty_cur_commitment_point.unwrap(), false, true, logger);
8779+
let counterparty_commitment_tx = commitment_data.stats.tx;
87528780

87538781
match &self.context.holder_signer {
87548782
ChannelSignerType::Ecdsa(ecdsa) => {
@@ -8757,24 +8785,25 @@ impl<SP: Deref> FundedChannel<SP> where
87578785
{
87588786
let res = ecdsa.sign_counterparty_commitment(
87598787
&self.funding.channel_transaction_parameters,
8760-
&commitment_stats.tx,
8761-
commitment_stats.inbound_htlc_preimages,
8762-
commitment_stats.outbound_htlc_preimages,
8788+
&counterparty_commitment_tx,
8789+
commitment_data.inbound_htlc_preimages,
8790+
commitment_data.outbound_htlc_preimages,
87638791
&self.context.secp_ctx,
87648792
).map_err(|_| ChannelError::Ignore("Failed to get signatures for new commitment_signed".to_owned()))?;
87658793
signature = res.0;
87668794
htlc_signatures = res.1;
87678795

8796+
let trusted_tx = counterparty_commitment_tx.trust();
87688797
log_trace!(logger, "Signed remote commitment tx {} (txid {}) with redeemscript {} -> {} in channel {}",
8769-
encode::serialize_hex(&commitment_stats.tx.trust().built_transaction().transaction),
8770-
&counterparty_commitment_txid, encode::serialize_hex(&self.funding.get_funding_redeemscript()),
8798+
encode::serialize_hex(&trusted_tx.built_transaction().transaction),
8799+
&trusted_tx.txid(), encode::serialize_hex(&self.funding.get_funding_redeemscript()),
87718800
log_bytes!(signature.serialize_compact()[..]), &self.context.channel_id());
87728801

8773-
let counterparty_keys = commitment_stats.tx.trust().keys();
8774-
debug_assert_eq!(htlc_signatures.len(), commitment_stats.tx.htlcs().len());
8775-
for (ref htlc_sig, ref htlc) in htlc_signatures.iter().zip(commitment_stats.tx.htlcs()) {
8802+
let counterparty_keys = trusted_tx.keys();
8803+
debug_assert_eq!(htlc_signatures.len(), trusted_tx.htlcs().len());
8804+
for (ref htlc_sig, ref htlc) in htlc_signatures.iter().zip(trusted_tx.htlcs()) {
87768805
log_trace!(logger, "Signed remote HTLC tx {} with redeemscript {} with pubkey {} -> {} in channel {}",
8777-
encode::serialize_hex(&chan_utils::build_htlc_transaction(&counterparty_commitment_txid, commitment_stats.tx.feerate_per_kw(), self.funding.get_holder_selected_contest_delay(), htlc, &self.context.channel_type, &counterparty_keys.broadcaster_delayed_payment_key, &counterparty_keys.revocation_key)),
8806+
encode::serialize_hex(&chan_utils::build_htlc_transaction(&trusted_tx.txid(), trusted_tx.feerate_per_kw(), self.funding.get_holder_selected_contest_delay(), htlc, &self.context.channel_type, &counterparty_keys.broadcaster_delayed_payment_key, &counterparty_keys.revocation_key)),
87788807
encode::serialize_hex(&chan_utils::get_htlc_redeemscript(&htlc, &self.context.channel_type, &counterparty_keys)),
87798808
log_bytes!(counterparty_keys.broadcaster_htlc_key.to_public_key().serialize()),
87808809
log_bytes!(htlc_sig.serialize_compact()[..]), &self.context.channel_id());
@@ -9228,7 +9257,10 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
92289257

92299258
/// Only allowed after [`FundingScope::channel_transaction_parameters`] is set.
92309259
fn get_funding_created_msg<L: Deref>(&mut self, logger: &L) -> Option<msgs::FundingCreated> where L::Target: Logger {
9231-
let counterparty_initial_commitment_tx = self.context.build_commitment_transaction(&self.funding, self.context.cur_counterparty_commitment_transaction_number, &self.context.counterparty_cur_commitment_point.unwrap(), false, false, logger).tx;
9260+
let commitment_data = self.context.build_commitment_transaction(&self.funding,
9261+
self.context.cur_counterparty_commitment_transaction_number,
9262+
&self.context.counterparty_cur_commitment_point.unwrap(), false, false, logger);
9263+
let counterparty_initial_commitment_tx = commitment_data.stats.tx;
92329264
let signature = match &self.context.holder_signer {
92339265
// TODO (taproot|arik): move match into calling method for Taproot
92349266
ChannelSignerType::Ecdsa(ecdsa) => {
@@ -11879,8 +11911,9 @@ mod tests {
1187911911
( $counterparty_sig_hex: expr, $sig_hex: expr, $tx_hex: expr, $opt_anchors: expr, {
1188011912
$( { $htlc_idx: expr, $counterparty_htlc_sig_hex: expr, $htlc_sig_hex: expr, $htlc_tx_hex: expr } ), *
1188111913
} ) => { {
11882-
let commitment_stats = chan.context.build_commitment_transaction(&chan.funding, 0xffffffffffff - 42, &per_commitment_point, true, false, &logger);
11883-
let commitment_tx = commitment_stats.tx;
11914+
let commitment_data = chan.context.build_commitment_transaction(&chan.funding,
11915+
0xffffffffffff - 42, &per_commitment_point, true, false, &logger);
11916+
let commitment_tx = commitment_data.stats.tx;
1188411917
let trusted_tx = commitment_tx.trust();
1188511918
let unsigned_tx = trusted_tx.built_transaction();
1188611919
let redeemscript = chan.funding.get_funding_redeemscript();

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