holding_cell_msat: u64,
}
+/// An enum gathering stats on commitment transaction, either local or remote.
+struct CommitmentStats<'a> {
+ tx: CommitmentTransaction, // the transaction info
+ feerate_per_kw: u32, // the feerate included to build the transaction
+ total_fee_sat: u64, // the total fee included in the transaction
+ num_nondust_htlcs: usize, // the number of HTLC outputs (dust HTLCs *non*-included)
+ htlcs_included: Vec<(HTLCOutputInCommitment, Option<&'a HTLCSource>)>, // the list of HTLCs (dust HTLCs *included*) which were not ignored when building the transaction
+ local_balance_msat: u64, // local balance before fees but considering dust limits
+ remote_balance_msat: u64, // remote balance before fees but considering dust limits
+}
+
/// Used when calculating whether we or the remote can afford an additional HTLC.
struct HTLCCandidate {
amount_msat: u64,
/// have not yet committed it. Such HTLCs will only be included in transactions which are being
/// generated by the peer which proposed adding the HTLCs, and thus we need to understand both
/// which peer generated this transaction and "to whom" this transaction flows.
- /// Returns (the transaction info, the number of HTLC outputs which were present in the
- /// transaction, the list of HTLCs which were not ignored when building the transaction).
- /// Note that below-dust HTLCs are included in the fourth return value, but not the third, and
- /// sources are provided only for outbound HTLCs in the fourth return value.
- /// Note that fifth and sixth return values are respectively anticipated holder and counterparty
- /// balance, not the value actually paid on-chain, which may be zero if it got rounded to dust.
#[inline]
- fn build_commitment_transaction<L: Deref>(&self, commitment_number: u64, keys: &TxCreationKeys, local: bool, generated_by_local: bool, logger: &L) -> (CommitmentTransaction, u32, usize, Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)>, u64, u64) where L::Target: Logger {
+ fn build_commitment_transaction<L: Deref>(&self, commitment_number: u64, keys: &TxCreationKeys, local: bool, generated_by_local: bool, logger: &L) -> CommitmentStats
+ where L::Target: Logger
+ {
let mut included_dust_htlcs: Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)> = Vec::new();
let num_htlcs = self.pending_inbound_htlcs.len() + self.pending_outbound_htlcs.len();
let mut included_non_dust_htlcs: Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)> = Vec::with_capacity(num_htlcs);
}
}
- let value_to_self_msat: i64 = (self.value_to_self_msat - local_htlc_total_msat) as i64 + value_to_self_msat_offset;
+ let mut value_to_self_msat: i64 = (self.value_to_self_msat - local_htlc_total_msat) as i64 + value_to_self_msat_offset;
assert!(value_to_self_msat >= 0);
// Note that in case they have several just-awaiting-last-RAA fulfills in-progress (ie
// AwaitingRemoteRevokeToRemove or AwaitingRemovedRemoteRevoke) we may have allowed them to
// "violate" their reserve value by couting those against it. Thus, we have to convert
// everything to i64 before subtracting as otherwise we can overflow.
- let value_to_remote_msat: i64 = (self.channel_value_satoshis * 1000) as i64 - (self.value_to_self_msat as i64) - (remote_htlc_total_msat as i64) - value_to_self_msat_offset;
+ let mut value_to_remote_msat: i64 = (self.channel_value_satoshis * 1000) as i64 - (self.value_to_self_msat as i64) - (remote_htlc_total_msat as i64) - value_to_self_msat_offset;
assert!(value_to_remote_msat >= 0);
#[cfg(debug_assertions)]
htlcs_included.sort_unstable_by_key(|h| h.0.transaction_output_index.unwrap());
htlcs_included.append(&mut included_dust_htlcs);
- (tx, feerate_per_kw, num_nondust_htlcs, htlcs_included, value_to_self_msat as u64, value_to_remote_msat as u64)
+ // For the stats, trimmed-to-0 the value in msats accordingly
+ value_to_self_msat = if (value_to_self_msat * 1000) < broadcaster_dust_limit_satoshis as i64 { 0 } else { value_to_self_msat };
+ value_to_remote_msat = if (value_to_remote_msat * 1000) < broadcaster_dust_limit_satoshis as i64 { 0 } else { value_to_remote_msat };
+
+ CommitmentStats {
+ tx,
+ feerate_per_kw,
+ total_fee_sat,
+ num_nondust_htlcs,
+ htlcs_included,
+ local_balance_msat: value_to_self_msat as u64,
+ remote_balance_msat: value_to_remote_msat as u64,
+ }
}
#[inline]
let funding_script = self.get_funding_redeemscript();
let keys = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number)?;
- let initial_commitment_tx = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, false, logger).0;
+ let initial_commitment_tx = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, false, logger).tx;
{
let trusted_tx = initial_commitment_tx.trust();
let initial_commitment_bitcoin_tx = trusted_tx.built_transaction();
}
let counterparty_keys = self.build_remote_transaction_keys()?;
- let counterparty_initial_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).0;
+ let counterparty_initial_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;
let counterparty_trusted_tx = counterparty_initial_commitment_tx.trust();
let counterparty_initial_bitcoin_tx = counterparty_trusted_tx.built_transaction();
let funding_script = self.get_funding_redeemscript();
let counterparty_keys = self.build_remote_transaction_keys()?;
- let counterparty_initial_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).0;
+ let counterparty_initial_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;
let counterparty_trusted_tx = counterparty_initial_commitment_tx.trust();
let counterparty_initial_bitcoin_tx = counterparty_trusted_tx.built_transaction();
log_bytes!(self.channel_id()), counterparty_initial_bitcoin_tx.txid, encode::serialize_hex(&counterparty_initial_bitcoin_tx.transaction));
let holder_signer = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number)?;
- let initial_commitment_tx = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &holder_signer, true, false, logger).0;
+ let initial_commitment_tx = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &holder_signer, true, false, logger).tx;
{
let trusted_tx = initial_commitment_tx.trust();
let initial_commitment_bitcoin_tx = trusted_tx.built_transaction();
let keys = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number).map_err(|e| (None, e))?;
- let (num_htlcs, mut htlcs_cloned, commitment_tx, commitment_txid, feerate_per_kw, _, counterparty_balance_msat) = {
- let commitment_tx = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, false, logger);
- let commitment_txid = {
- let trusted_tx = commitment_tx.0.trust();
- let bitcoin_tx = trusted_tx.built_transaction();
- let sighash = bitcoin_tx.get_sighash_all(&funding_script, self.channel_value_satoshis);
-
- log_trace!(logger, "Checking commitment tx signature {} by key {} against tx {} (sighash {}) with redeemscript {} in channel {}",
- log_bytes!(msg.signature.serialize_compact()[..]),
- log_bytes!(self.counterparty_funding_pubkey().serialize()), encode::serialize_hex(&bitcoin_tx.transaction),
- log_bytes!(sighash[..]), encode::serialize_hex(&funding_script), log_bytes!(self.channel_id()));
- if let Err(_) = self.secp_ctx.verify(&sighash, &msg.signature, &self.counterparty_funding_pubkey()) {
- return Err((None, ChannelError::Close("Invalid commitment tx signature from peer".to_owned())));
- }
- bitcoin_tx.txid
- };
- let htlcs_cloned: Vec<_> = commitment_tx.3.iter().map(|htlc| (htlc.0.clone(), htlc.1.map(|h| h.clone()))).collect();
- (commitment_tx.2, htlcs_cloned, commitment_tx.0, commitment_txid, commitment_tx.1, commitment_tx.4, commitment_tx.5)
+ let commitment_stats = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, false, logger);
+ let commitment_txid = {
+ let trusted_tx = commitment_stats.tx.trust();
+ let bitcoin_tx = trusted_tx.built_transaction();
+ let sighash = bitcoin_tx.get_sighash_all(&funding_script, self.channel_value_satoshis);
+
+ log_trace!(logger, "Checking commitment tx signature {} by key {} against tx {} (sighash {}) with redeemscript {} in channel {}",
+ log_bytes!(msg.signature.serialize_compact()[..]),
+ log_bytes!(self.counterparty_funding_pubkey().serialize()), encode::serialize_hex(&bitcoin_tx.transaction),
+ log_bytes!(sighash[..]), encode::serialize_hex(&funding_script), log_bytes!(self.channel_id()));
+ if let Err(_) = self.secp_ctx.verify(&sighash, &msg.signature, &self.counterparty_funding_pubkey()) {
+ return Err((None, ChannelError::Close("Invalid commitment tx signature from peer".to_owned())));
+ }
+ bitcoin_tx.txid
};
+ let mut htlcs_cloned: Vec<_> = commitment_stats.htlcs_included.iter().map(|htlc| (htlc.0.clone(), htlc.1.map(|h| h.clone()))).collect();
// If our counterparty updated the channel fee in this commitment transaction, check that
// they can actually afford the new fee now.
let update_fee = if let Some((_, update_state)) = self.pending_update_fee {
update_state == FeeUpdateState::RemoteAnnounced
} else { false };
- if update_fee { debug_assert!(!self.is_outbound()); }
- let total_fee_sat = Channel::<Signer>::commit_tx_fee_sat(feerate_per_kw, num_htlcs);
if update_fee {
- let counterparty_reserve_we_require = Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(self.channel_value_satoshis);
- if counterparty_balance_msat < total_fee_sat * 1000 + counterparty_reserve_we_require * 1000 {
+ debug_assert!(!self.is_outbound());
+ let counterparty_reserve_we_require_msat = Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(self.channel_value_satoshis) * 1000;
+ if commitment_stats.remote_balance_msat < commitment_stats.total_fee_sat * 1000 + counterparty_reserve_we_require_msat {
return Err((None, ChannelError::Close("Funding remote cannot afford proposed new fee".to_owned())));
}
}
&& info.next_holder_htlc_id == self.next_holder_htlc_id
&& info.next_counterparty_htlc_id == self.next_counterparty_htlc_id
&& info.feerate == self.feerate_per_kw {
- assert_eq!(total_fee_sat, info.fee / 1000);
+ assert_eq!(commitment_stats.total_fee_sat, info.fee / 1000);
}
}
}
}
- if msg.htlc_signatures.len() != num_htlcs {
- return Err((None, ChannelError::Close(format!("Got wrong number of HTLC signatures ({}) from remote. It must be {}", msg.htlc_signatures.len(), num_htlcs))));
+ if msg.htlc_signatures.len() != commitment_stats.num_nondust_htlcs {
+ return Err((None, ChannelError::Close(format!("Got wrong number of HTLC signatures ({}) from remote. It must be {}", msg.htlc_signatures.len(), commitment_stats.num_nondust_htlcs))));
}
// TODO: Sadly, we pass HTLCs twice to ChannelMonitor: once via the HolderCommitmentTransaction and once via the update
let mut htlcs_and_sigs = Vec::with_capacity(htlcs_cloned.len());
for (idx, (htlc, source)) in htlcs_cloned.drain(..).enumerate() {
if let Some(_) = htlc.transaction_output_index {
- let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, feerate_per_kw,
+ let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_stats.feerate_per_kw,
self.get_counterparty_selected_contest_delay().unwrap(), &htlc,
&keys.broadcaster_delayed_payment_key, &keys.revocation_key);
}
let holder_commitment_tx = HolderCommitmentTransaction::new(
- commitment_tx,
+ commitment_stats.tx,
msg.signature,
msg.htlc_signatures.clone(),
&self.get_holder_pubkeys().funding_pubkey,
let inbound_stats = self.get_inbound_pending_htlc_stats(Some(feerate_per_kw));
let outbound_stats = self.get_outbound_pending_htlc_stats(Some(feerate_per_kw));
let keys = if let Ok(keys) = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number) { keys } else { return None; };
- let (_, _, num_htlcs, _, holder_balance_msat, _) = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, true, logger);
- let total_fee_sat = Channel::<Signer>::commit_tx_fee_sat(feerate_per_kw, num_htlcs + CONCURRENT_INBOUND_HTLC_FEE_BUFFER as usize);
- let holder_balance_msat = holder_balance_msat - outbound_stats.holding_cell_msat;
- if holder_balance_msat < total_fee_sat * 1000 + self.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000 {
+ let commitment_stats = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, true, logger);
+ let buffer_fee_msat = Channel::<Signer>::commit_tx_fee_sat(feerate_per_kw, commitment_stats.num_nondust_htlcs + CONCURRENT_INBOUND_HTLC_FEE_BUFFER as usize) * 1000;
+ let holder_balance_msat = commitment_stats.local_balance_msat - outbound_stats.holding_cell_msat;
+ if holder_balance_msat < buffer_fee_msat + self.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000 {
//TODO: auto-close after a number of failures?
log_debug!(logger, "Cannot afford to send new feerate at {}", feerate_per_kw);
return None;
/// If an Err is returned, it is a ChannelError::Close (for get_outbound_funding_created)
fn get_outbound_funding_created_signature<L: Deref>(&mut self, logger: &L) -> Result<Signature, ChannelError> where L::Target: Logger {
let counterparty_keys = self.build_remote_transaction_keys()?;
- let counterparty_initial_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).0;
+ let counterparty_initial_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;
Ok(self.holder_signer.sign_counterparty_commitment(&counterparty_initial_commitment_tx, &self.secp_ctx)
.map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?.0)
}
}
let keys = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number)?;
+ let commitment_stats = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, true, logger);
if !self.is_outbound() {
// Check that we won't violate the remote channel reserve by adding this HTLC.
- let counterparty_balance_msat = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, true, logger).5;
let htlc_candidate = HTLCCandidate::new(amount_msat, HTLCInitiator::LocalOffered);
let counterparty_commit_tx_fee_msat = self.next_remote_commit_tx_fee_msat(htlc_candidate, None);
let holder_selected_chan_reserve_msat = Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(self.channel_value_satoshis) * 1000;
- if counterparty_balance_msat < counterparty_commit_tx_fee_msat + holder_selected_chan_reserve_msat {
+ if commitment_stats.remote_balance_msat < counterparty_commit_tx_fee_msat + holder_selected_chan_reserve_msat {
return Err(ChannelError::Ignore("Cannot send value that would put counterparty balance under holder-announced channel reserve value".to_owned()));
}
}
}
}
- let holder_balance_msat = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, true, logger).4 as u64 - outbound_stats.holding_cell_msat;
+ let holder_balance_msat = commitment_stats.local_balance_msat - outbound_stats.holding_cell_msat;
if holder_balance_msat < amount_msat {
return Err(ChannelError::Ignore(format!("Cannot send value that would overdraw remaining funds. Amount: {}, pending value to self {}", amount_msat, holder_balance_msat)));
}
/// when we shouldn't change HTLC/channel state.
fn send_commitment_no_state_update<L: Deref>(&self, logger: &L) -> Result<(msgs::CommitmentSigned, (Txid, Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)>)), ChannelError> where L::Target: Logger {
let counterparty_keys = self.build_remote_transaction_keys()?;
- let counterparty_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, true, logger);
- let feerate_per_kw = counterparty_commitment_tx.1;
- let counterparty_commitment_txid = counterparty_commitment_tx.0.trust().txid();
+ let commitment_stats = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, true, logger);
+ let counterparty_commitment_txid = commitment_stats.tx.trust().txid();
let (signature, htlc_signatures);
#[cfg(any(test, feature = "fuzztarget"))]
&& info.next_holder_htlc_id == self.next_holder_htlc_id
&& info.next_counterparty_htlc_id == self.next_counterparty_htlc_id
&& info.feerate == self.feerate_per_kw {
- let actual_fee = self.commit_tx_fee_msat(counterparty_commitment_tx.2);
+ let actual_fee = self.commit_tx_fee_msat(commitment_stats.num_nondust_htlcs);
assert_eq!(actual_fee, info.fee);
}
}
}
{
- let mut htlcs = Vec::with_capacity(counterparty_commitment_tx.3.len());
- for &(ref htlc, _) in counterparty_commitment_tx.3.iter() {
+ let mut htlcs = Vec::with_capacity(commitment_stats.htlcs_included.len());
+ for &(ref htlc, _) in commitment_stats.htlcs_included.iter() {
htlcs.push(htlc);
}
- let res = self.holder_signer.sign_counterparty_commitment(&counterparty_commitment_tx.0, &self.secp_ctx)
+ let res = self.holder_signer.sign_counterparty_commitment(&commitment_stats.tx, &self.secp_ctx)
.map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?;
signature = res.0;
htlc_signatures = res.1;
log_trace!(logger, "Signed remote commitment tx {} (txid {}) with redeemscript {} -> {} in channel {}",
- encode::serialize_hex(&counterparty_commitment_tx.0.trust().built_transaction().transaction),
+ encode::serialize_hex(&commitment_stats.tx.trust().built_transaction().transaction),
&counterparty_commitment_txid, encode::serialize_hex(&self.get_funding_redeemscript()),
log_bytes!(signature.serialize_compact()[..]), log_bytes!(self.channel_id()));
for (ref htlc_sig, ref htlc) in htlc_signatures.iter().zip(htlcs) {
log_trace!(logger, "Signed remote HTLC tx {} with redeemscript {} with pubkey {} -> {} in channel {}",
- encode::serialize_hex(&chan_utils::build_htlc_transaction(&counterparty_commitment_txid, feerate_per_kw, self.get_holder_selected_contest_delay(), htlc, &counterparty_keys.broadcaster_delayed_payment_key, &counterparty_keys.revocation_key)),
+ encode::serialize_hex(&chan_utils::build_htlc_transaction(&counterparty_commitment_txid, commitment_stats.feerate_per_kw, self.get_holder_selected_contest_delay(), htlc, &counterparty_keys.broadcaster_delayed_payment_key, &counterparty_keys.revocation_key)),
encode::serialize_hex(&chan_utils::get_htlc_redeemscript(&htlc, &counterparty_keys)),
log_bytes!(counterparty_keys.broadcaster_htlc_key.serialize()),
log_bytes!(htlc_sig.serialize_compact()[..]), log_bytes!(self.channel_id()));
channel_id: self.channel_id,
signature,
htlc_signatures,
- }, (counterparty_commitment_txid, counterparty_commitment_tx.3)))
+ }, (counterparty_commitment_txid, commitment_stats.htlcs_included)))
}
/// Adds a pending outbound HTLC to this channel, and creates a signed commitment transaction
$( { $htlc_idx: expr, $counterparty_htlc_sig_hex: expr, $htlc_sig_hex: expr, $htlc_tx_hex: expr } ), *
} ) => { {
let (commitment_tx, htlcs): (_, Vec<HTLCOutputInCommitment>) = {
- let mut res = chan.build_commitment_transaction(0xffffffffffff - 42, &keys, true, false, &logger);
+ let mut commitment_stats = chan.build_commitment_transaction(0xffffffffffff - 42, &keys, true, false, &logger);
- let htlcs = res.3.drain(..)
+ let htlcs = commitment_stats.htlcs_included.drain(..)
.filter_map(|(htlc, _)| if htlc.transaction_output_index.is_some() { Some(htlc) } else { None })
.collect();
- (res.0, htlcs)
+ (commitment_stats.tx, htlcs)
};
let trusted_tx = commitment_tx.trust();
let unsigned_tx = trusted_tx.built_transaction();