From 14335358d0c8c4707cc6beeb7e807f6bb513ba31 Mon Sep 17 00:00:00 2001 From: Antoine Riard Date: Wed, 12 Feb 2020 13:00:29 -0500 Subject: [PATCH] Structurify claim request handed between detection/reaction --- lightning/src/ln/channelmonitor.rs | 40 ++++++++++++++++++++++++------ lightning/src/ln/onchaintx.rs | 22 ++++++++-------- 2 files changed, 44 insertions(+), 18 deletions(-) diff --git a/lightning/src/ln/channelmonitor.rs b/lightning/src/ln/channelmonitor.rs index a8fdb32a..67e306b4 100644 --- a/lightning/src/ln/channelmonitor.rs +++ b/lightning/src/ln/channelmonitor.rs @@ -554,6 +554,28 @@ impl Readable for InputMaterial { } } +/// ClaimRequest is a descriptor structure to communicate between detection +/// and reaction module. They are generated by ChannelMonitor while parsing +/// onchain txn leaked from a channel and handed over to OnchainTxHandler which +/// is responsible for opportunistic aggregation, selecting and enforcing +/// bumping logic, building and signing transactions. +pub(crate) struct ClaimRequest { + // Block height before which claiming is exclusive to one party, + // after reaching it, claiming may be contentious. + pub(crate) absolute_timelock: u32, + // Timeout tx must have nLocktime set which means aggregating multiple + // ones must take the higher nLocktime among them to satisfy all of them. + // Sadly it has few pitfalls, a) it takes longuer to get fund back b) CLTV_DELTA + // of a sooner-HTLC could be swallowed by the highest nLocktime of the HTLC set. + // Do simplify we mark them as non-aggregable. + pub(crate) aggregable: bool, + // Basic bitcoin outpoint (txid, vout) + pub(crate) outpoint: BitcoinOutPoint, + // Following outpoint type, set of data needed to generate transaction digest + // and satisfy witness program. + pub(crate) witness_data: InputMaterial +} + /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it /// once they mature to enough confirmations (ANTI_REORG_DELAY) #[derive(Clone, PartialEq)] @@ -1385,7 +1407,7 @@ impl ChannelMonitor { /// HTLC-Success/HTLC-Timeout transactions. /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of /// revoked remote commitment tx - fn check_spend_remote_transaction(&mut self, tx: &Transaction, height: u32) -> (Vec<(u32, bool, BitcoinOutPoint, InputMaterial)>, (Sha256dHash, Vec), Vec) { + fn check_spend_remote_transaction(&mut self, tx: &Transaction, height: u32) -> (Vec, (Sha256dHash, Vec), Vec) { // Most secp and related errors trying to create keys means we have no hope of constructing // a spend transaction...so we return no transactions to broadcast let mut claimable_outpoints = Vec::new(); @@ -1439,7 +1461,8 @@ impl ChannelMonitor { // First, process non-htlc outputs (to_local & to_remote) for (idx, outp) in tx.output.iter().enumerate() { if outp.script_pubkey == revokeable_p2wsh { - claimable_outpoints.push((height + self.our_to_self_delay as u32, true, BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 }, InputMaterial::Revoked { script: revokeable_redeemscript.clone(), pubkey: Some(revocation_pubkey), key: revocation_key, is_htlc: false, amount: outp.value })); + let witness_data = InputMaterial::Revoked { script: revokeable_redeemscript.clone(), pubkey: Some(revocation_pubkey), key: revocation_key, is_htlc: false, amount: outp.value }; + claimable_outpoints.push(ClaimRequest { absolute_timelock: height + self.our_to_self_delay as u32, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 }, witness_data}); } else if Some(&outp.script_pubkey) == local_payment_p2wpkh.as_ref() { spendable_outputs.push(SpendableOutputDescriptor::DynamicOutputP2WPKH { outpoint: BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 }, @@ -1459,7 +1482,8 @@ impl ChannelMonitor { tx.output[transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() { return (claimable_outpoints, (commitment_txid, watch_outputs), spendable_outputs); // Corrupted per_commitment_data, fuck this user } - claimable_outpoints.push((htlc.cltv_expiry, true, BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, InputMaterial::Revoked { script: expected_script, pubkey: Some(revocation_pubkey), key: revocation_key, is_htlc: true, amount: tx.output[transaction_output_index as usize].value })); + let witness_data = InputMaterial::Revoked { script: expected_script, pubkey: Some(revocation_pubkey), key: revocation_key, is_htlc: true, amount: tx.output[transaction_output_index as usize].value }; + claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data }); } } } @@ -1622,7 +1646,8 @@ impl ChannelMonitor { let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None }; let aggregable = if !htlc.offered { false } else { true }; if preimage.is_some() || !htlc.offered { - claimable_outpoints.push((htlc.cltv_expiry, aggregable, BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, InputMaterial::RemoteHTLC { script: expected_script, key: htlc_privkey, preimage, amount: htlc.amount_msat / 1000, locktime: htlc.cltv_expiry })); + let witness_data = InputMaterial::RemoteHTLC { script: expected_script, key: htlc_privkey, preimage, amount: htlc.amount_msat / 1000, locktime: htlc.cltv_expiry }; + claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data }); } } } @@ -1643,7 +1668,7 @@ impl ChannelMonitor { } /// Attempts to claim a remote HTLC-Success/HTLC-Timeout's outputs using the revocation key - fn check_spend_remote_htlc(&mut self, tx: &Transaction, commitment_number: u64, height: u32) -> Vec<(u32, bool, BitcoinOutPoint, InputMaterial)> { + fn check_spend_remote_htlc(&mut self, tx: &Transaction, commitment_number: u64, height: u32) -> Vec { //TODO: send back new outputs to guarantee pending_claim_request consistency if tx.input.len() != 1 || tx.output.len() != 1 || tx.input[0].witness.len() != 5 { return Vec::new() @@ -1676,7 +1701,8 @@ impl ChannelMonitor { let htlc_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers! log_trace!(self, "Remote HTLC broadcast {}:{}", htlc_txid, 0); - let claimable_outpoints = vec!((height + self.our_to_self_delay as u32, true, BitcoinOutPoint { txid: htlc_txid, vout: 0}, InputMaterial::Revoked { script: redeemscript, pubkey: Some(revocation_pubkey), key: revocation_key, is_htlc: false, amount: tx.output[0].value })); + let witness_data = InputMaterial::Revoked { script: redeemscript, pubkey: Some(revocation_pubkey), key: revocation_key, is_htlc: false, amount: tx.output[0].value }; + let claimable_outpoints = vec!(ClaimRequest { absolute_timelock: height + self.our_to_self_delay as u32, aggregable: true, outpoint: BitcoinOutPoint { txid: htlc_txid, vout: 0}, witness_data }); claimable_outpoints } @@ -2050,7 +2076,7 @@ impl ChannelMonitor { } } } - let mut spendable_output = self.onchain_tx_handler.block_connected(txn_matched, claimable_outpoints, height, broadcaster, &*fee_estimator); + let mut spendable_output = self.onchain_tx_handler.block_connected(txn_matched, claimable_outpoints, height, &*broadcaster, &*fee_estimator); spendable_outputs.append(&mut spendable_output); self.last_block_hash = block_hash.clone(); diff --git a/lightning/src/ln/onchaintx.rs b/lightning/src/ln/onchaintx.rs index 7bacc91a..1166696f 100644 --- a/lightning/src/ln/onchaintx.rs +++ b/lightning/src/ln/onchaintx.rs @@ -14,7 +14,7 @@ use secp256k1::Secp256k1; use secp256k1; use ln::msgs::DecodeError; -use ln::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER, InputMaterial}; +use ln::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER, InputMaterial, ClaimRequest}; use ln::chan_utils::HTLCType; use chain::chaininterface::{FeeEstimator, BroadcasterInterface, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT}; use chain::keysinterface::SpendableOutputDescriptor; @@ -471,7 +471,7 @@ impl OnchainTxHandler { Some((new_timer, new_feerate, bumped_tx)) } - pub(super) fn block_connected(&mut self, txn_matched: &[&Transaction], claimable_outpoints: Vec>, height: u32, broadcaster: B, fee_estimator: F) -> Vec + pub(super) fn block_connected(&mut self, txn_matched: &[&Transaction], claimable_outpoints: Vec>, height: u32, broadcaster: B, fee_estimator: F) -> Vec where B::Target: BroadcasterInterface, F::Target: FeeEstimator { @@ -483,18 +483,18 @@ impl OnchainTxHandler { // Try to aggregate outputs if they're 1) belong to same parent tx, 2) their // timelock expiration isn't imminent (<= CLTV_SHARED_CLAIM_BUFFER). for siblings_outpoints in claimable_outpoints { - for outp in siblings_outpoints { + for req in siblings_outpoints { // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while - if let Some(_) = self.claimable_outpoints.get(&outp.2) { log_trace!(self, "Bouncing off outpoint {}:{}, already registered its claiming request", outp.2.txid, outp.2.vout); } else { - log_trace!(self, "Test if outpoint can be aggregated with expiration {} against {}", outp.0, height + CLTV_SHARED_CLAIM_BUFFER); - if outp.0 <= height + CLTV_SHARED_CLAIM_BUFFER || !outp.1 { // Don't aggregate if outpoint absolute timelock is soon or marked as non-aggregable + if let Some(_) = self.claimable_outpoints.get(&req.outpoint) { log_trace!(self, "Bouncing off outpoint {}:{}, already registered its claiming request", req.outpoint.txid, req.outpoint.vout); } else { + log_trace!(self, "Test if outpoint can be aggregated with expiration {} against {}", req.absolute_timelock, height + CLTV_SHARED_CLAIM_BUFFER); + if req.absolute_timelock <= height + CLTV_SHARED_CLAIM_BUFFER || !req.aggregable { // Don't aggregate if outpoint absolute timelock is soon or marked as non-aggregable let mut single_input = HashMap::new(); - single_input.insert(outp.2, outp.3); - new_claims.push((outp.0, single_input)); + single_input.insert(req.outpoint, req.witness_data); + new_claims.push((req.absolute_timelock, single_input)); } else { - aggregated_claim.insert(outp.2, outp.3); - if outp.0 < aggregated_soonest { - aggregated_soonest = outp.0; + aggregated_claim.insert(req.outpoint, req.witness_data); + if req.absolute_timelock < aggregated_soonest { + aggregated_soonest = req.absolute_timelock; } } } -- 2.30.2