From e70f4850114694075200732df1bf541819add9a4 Mon Sep 17 00:00:00 2001 From: Valentine Wallace Date: Thu, 12 Nov 2020 18:37:47 -0500 Subject: [PATCH] Split channelmonitor's broadcast_by_holder_state Now callers will separately retrieve the claim requests/ holder revokable script and the new watched holder outputs. This will be used in the next commit for times when we need to get holder claim requests, but don't have access to the holder commitment transaction. --- lightning/src/chain/channelmonitor.rs | 39 ++++++++++++++++++--------- 1 file changed, 27 insertions(+), 12 deletions(-) diff --git a/lightning/src/chain/channelmonitor.rs b/lightning/src/chain/channelmonitor.rs index 2428f0c9..425baedd 100644 --- a/lightning/src/chain/channelmonitor.rs +++ b/lightning/src/chain/channelmonitor.rs @@ -1525,9 +1525,11 @@ impl ChannelMonitor { (claimable_outpoints, Some((htlc_txid, outputs))) } - fn broadcast_by_holder_state(&self, commitment_tx: &Transaction, holder_tx: &HolderSignedTx) -> (Vec, Vec<(u32, TxOut)>, Option<(Script, PublicKey, PublicKey)>) { + // Returns (1) `ClaimRequest`s that can be given to the OnChainTxHandler, so that the handler can + // broadcast transactions claiming holder HTLC commitment outputs and (2) a holder revokable + // script so we can detect whether a holder transaction has been seen on-chain. + fn get_broadcasted_holder_claims(&self, holder_tx: &HolderSignedTx) -> (Vec, Option<(Script, PublicKey, PublicKey)>) { let mut claim_requests = Vec::with_capacity(holder_tx.htlc_outputs.len()); - let mut watch_outputs = Vec::with_capacity(holder_tx.htlc_outputs.len()); let redeemscript = chan_utils::get_revokeable_redeemscript(&holder_tx.revocation_key, self.on_holder_tx_csv, &holder_tx.delayed_payment_key); let broadcasted_holder_revokable_script = Some((redeemscript.to_v0_p2wsh(), holder_tx.per_commitment_point.clone(), holder_tx.revocation_key.clone())); @@ -1546,11 +1548,21 @@ impl ChannelMonitor { } else { None }, amount: htlc.amount_msat, }}); - watch_outputs.push((transaction_output_index, commitment_tx.output[transaction_output_index as usize].clone())); } } - (claim_requests, watch_outputs, broadcasted_holder_revokable_script) + (claim_requests, broadcasted_holder_revokable_script) + } + + // Returns holder HTLC outputs to watch and react to in case of spending. + fn get_broadcasted_holder_watch_outputs(&self, holder_tx: &HolderSignedTx, commitment_tx: &Transaction) -> Vec<(u32, TxOut)> { + let mut watch_outputs = Vec::with_capacity(holder_tx.htlc_outputs.len()); + for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() { + if let Some(transaction_output_index) = htlc.transaction_output_index { + watch_outputs.push((transaction_output_index, commitment_tx.output[transaction_output_index as usize].clone())); + } + } + watch_outputs } /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet) @@ -1585,10 +1597,10 @@ impl ChannelMonitor { } macro_rules! append_onchain_update { - ($updates: expr) => { + ($updates: expr, $to_watch: expr) => { claim_requests = $updates.0; - watch_outputs.append(&mut $updates.1); - self.broadcasted_holder_revokable_script = $updates.2; + self.broadcasted_holder_revokable_script = $updates.1; + watch_outputs.append(&mut $to_watch); } } @@ -1598,14 +1610,16 @@ impl ChannelMonitor { if self.current_holder_commitment_tx.txid == commitment_txid { is_holder_tx = true; log_trace!(logger, "Got latest holder commitment tx broadcast, searching for available HTLCs to claim"); - let mut res = self.broadcast_by_holder_state(tx, &self.current_holder_commitment_tx); - append_onchain_update!(res); + let res = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx); + let mut to_watch = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, tx); + append_onchain_update!(res, to_watch); } else if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx { if holder_tx.txid == commitment_txid { is_holder_tx = true; log_trace!(logger, "Got previous holder commitment tx broadcast, searching for available HTLCs to claim"); - let mut res = self.broadcast_by_holder_state(tx, holder_tx); - append_onchain_update!(res); + let res = self.get_broadcasted_holder_claims(holder_tx); + let mut to_watch = self.get_broadcasted_holder_watch_outputs(holder_tx, tx); + append_onchain_update!(res, to_watch); } } @@ -1773,7 +1787,8 @@ impl ChannelMonitor { self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0)); if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript) { self.holder_tx_signed = true; - let (mut new_outpoints, new_outputs, _) = self.broadcast_by_holder_state(&commitment_tx, &self.current_holder_commitment_tx); + let (mut new_outpoints, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx); + let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &commitment_tx); if !new_outputs.is_empty() { watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs)); } -- 2.30.2