From: Wilmer Paulino Date: Thu, 25 Aug 2022 20:09:29 +0000 (-0700) Subject: Track HTLC resolving transaction to determine input index X-Git-Tag: v0.0.113~12^2~9 X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=af02d10c3b7f643c404a473cab0c7efccee24346;p=rust-lightning Track HTLC resolving transaction to determine input index --- diff --git a/lightning/src/chain/channelmonitor.rs b/lightning/src/chain/channelmonitor.rs index 2be7f4cf..522cdd87 100644 --- a/lightning/src/chain/channelmonitor.rs +++ b/lightning/src/chain/channelmonitor.rs @@ -647,6 +647,7 @@ struct IrrevocablyResolvedHTLC { /// was not present in the confirmed commitment transaction), HTLC-Success, or HTLC-Timeout /// transaction. resolving_txid: Option, // Added as optional, but always filled in, in 0.0.110 + resolving_tx: Option, /// Only set if the HTLC claim was ours using a payment preimage payment_preimage: Option, } @@ -662,6 +663,7 @@ impl Writeable for IrrevocablyResolvedHTLC { (0, mapped_commitment_tx_output_idx, required), (1, self.resolving_txid, option), (2, self.payment_preimage, option), + (3, self.resolving_tx, option), }); Ok(()) } @@ -672,15 +674,18 @@ impl Readable for IrrevocablyResolvedHTLC { let mut mapped_commitment_tx_output_idx = 0; let mut resolving_txid = None; let mut payment_preimage = None; + let mut resolving_tx = None; read_tlv_fields!(reader, { (0, mapped_commitment_tx_output_idx, required), (1, resolving_txid, option), (2, payment_preimage, option), + (3, resolving_tx, option), }); Ok(Self { commitment_tx_output_idx: if mapped_commitment_tx_output_idx == u32::max_value() { None } else { Some(mapped_commitment_tx_output_idx) }, resolving_txid, payment_preimage, + resolving_tx, }) } } @@ -1526,6 +1531,7 @@ impl ChannelMonitorImpl { if let Some(v) = htlc.transaction_output_index { v } else { return None; }; let mut htlc_spend_txid_opt = None; + let mut htlc_spend_tx_opt = None; let mut holder_timeout_spend_pending = None; let mut htlc_spend_pending = None; let mut holder_delayed_output_pending = None; @@ -1534,7 +1540,9 @@ impl ChannelMonitorImpl { OnchainEvent::HTLCUpdate { commitment_tx_output_idx, htlc_value_satoshis, .. } if commitment_tx_output_idx == Some(htlc_commitment_tx_output_idx) => { debug_assert!(htlc_spend_txid_opt.is_none()); - htlc_spend_txid_opt = event.transaction.as_ref().map(|tx| tx.txid()); + htlc_spend_txid_opt = Some(&event.txid); + debug_assert!(htlc_spend_tx_opt.is_none()); + htlc_spend_tx_opt = event.transaction.as_ref(); debug_assert!(holder_timeout_spend_pending.is_none()); debug_assert_eq!(htlc_value_satoshis.unwrap(), htlc.amount_msat / 1000); holder_timeout_spend_pending = Some(event.confirmation_threshold()); @@ -1542,7 +1550,9 @@ impl ChannelMonitorImpl { OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, preimage, .. } if commitment_tx_output_idx == htlc_commitment_tx_output_idx => { debug_assert!(htlc_spend_txid_opt.is_none()); - htlc_spend_txid_opt = event.transaction.as_ref().map(|tx| tx.txid()); + htlc_spend_txid_opt = Some(&event.txid); + debug_assert!(htlc_spend_tx_opt.is_none()); + htlc_spend_tx_opt = event.transaction.as_ref(); debug_assert!(htlc_spend_pending.is_none()); htlc_spend_pending = Some((event.confirmation_threshold(), preimage.is_some())); }, @@ -1558,19 +1568,32 @@ impl ChannelMonitorImpl { let htlc_resolved = self.htlcs_resolved_on_chain.iter() .find(|v| if v.commitment_tx_output_idx == Some(htlc_commitment_tx_output_idx) { debug_assert!(htlc_spend_txid_opt.is_none()); - htlc_spend_txid_opt = v.resolving_txid; + htlc_spend_txid_opt = v.resolving_txid.as_ref(); + debug_assert!(htlc_spend_tx_opt.is_none()); + htlc_spend_tx_opt = v.resolving_tx.as_ref(); true } else { false }); debug_assert!(holder_timeout_spend_pending.is_some() as u8 + htlc_spend_pending.is_some() as u8 + htlc_resolved.is_some() as u8 <= 1); + let htlc_commitment_outpoint = BitcoinOutPoint::new(confirmed_txid.unwrap(), htlc_commitment_tx_output_idx); let htlc_output_to_spend = if let Some(txid) = htlc_spend_txid_opt { - debug_assert!( - self.onchain_tx_handler.channel_transaction_parameters.opt_anchors.is_none(), - "This code needs updating for anchors"); - BitcoinOutPoint::new(txid, 0) + // Because HTLC transactions either only have 1 input and 1 output (pre-anchors) or + // are signed with SIGHASH_SINGLE|ANYONECANPAY under BIP-0143 (post-anchors), we can + // locate the correct output by ensuring its adjacent input spends the HTLC output + // in the commitment. + if let Some(ref tx) = htlc_spend_tx_opt { + let htlc_input_idx_opt = tx.input.iter().enumerate() + .find(|(_, input)| input.previous_output == htlc_commitment_outpoint) + .map(|(idx, _)| idx as u32); + debug_assert!(htlc_input_idx_opt.is_some()); + BitcoinOutPoint::new(*txid, htlc_input_idx_opt.unwrap_or(0)) + } else { + debug_assert!(!self.onchain_tx_handler.opt_anchors()); + BitcoinOutPoint::new(*txid, 0) + } } else { - BitcoinOutPoint::new(confirmed_txid.unwrap(), htlc_commitment_tx_output_idx) + htlc_commitment_outpoint }; let htlc_output_spend_pending = self.onchain_tx_handler.is_output_spend_pending(&htlc_output_to_spend); @@ -1594,8 +1617,7 @@ impl ChannelMonitorImpl { } = &event.event { if event.transaction.as_ref().map(|tx| tx.input.iter().any(|inp| { if let Some(htlc_spend_txid) = htlc_spend_txid_opt { - Some(tx.txid()) == htlc_spend_txid_opt || - inp.previous_output.txid == htlc_spend_txid + tx.txid() == *htlc_spend_txid || inp.previous_output.txid == *htlc_spend_txid } else { Some(inp.previous_output.txid) == confirmed_txid && inp.previous_output.vout == htlc_commitment_tx_output_idx @@ -3074,7 +3096,9 @@ impl ChannelMonitorImpl { htlc_value_satoshis, })); self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC { - commitment_tx_output_idx, resolving_txid: Some(entry.txid), + commitment_tx_output_idx, + resolving_txid: Some(entry.txid), + resolving_tx: entry.transaction, payment_preimage: None, }); }, @@ -3087,7 +3111,9 @@ impl ChannelMonitorImpl { }, OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, preimage, .. } => { self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC { - commitment_tx_output_idx: Some(commitment_tx_output_idx), resolving_txid: Some(entry.txid), + commitment_tx_output_idx: Some(commitment_tx_output_idx), + resolving_txid: Some(entry.txid), + resolving_tx: entry.transaction, payment_preimage: preimage, }); }, diff --git a/lightning/src/util/events.rs b/lightning/src/util/events.rs index 28bd6978..f7ec29e7 100644 --- a/lightning/src/util/events.rs +++ b/lightning/src/util/events.rs @@ -249,7 +249,7 @@ pub enum BumpTransactionEvent { /// with additional inputs to meet the target feerate. Failure to meet the target feerate /// decreases the confirmation odds of the transaction package (which includes the commitment /// and child anchor transactions), possibly resulting in a loss of funds. Once the transaction - /// is constructed, it must be fully signed for and broadcasted by the consumer of the event + /// is constructed, it must be fully signed for and broadcast by the consumer of the event /// along with the `commitment_tx` enclosed. Note that the `commitment_tx` must always be /// broadcast first, as the child anchor transaction depends on it. ///