X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Fchannelmonitor.rs;h=bfde8cd91b09a97882984b78cb53331ec5542d76;hb=116b1eb028e02f32718ddd688348f64b719de31e;hp=2aded100c149e6dd27a93afbb5d0e0c8ed621132;hpb=6a7c471369ea3bde4625da9601873d4f1dca9bd3;p=rust-lightning diff --git a/lightning/src/ln/channelmonitor.rs b/lightning/src/ln/channelmonitor.rs index 2aded100..bfde8cd9 100644 --- a/lightning/src/ln/channelmonitor.rs +++ b/lightning/src/ln/channelmonitor.rs @@ -34,7 +34,7 @@ use ln::chan_utils; use ln::chan_utils::HTLCOutputInCommitment; use ln::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash}; use ln::channel::{ACCEPTED_HTLC_SCRIPT_WEIGHT, OFFERED_HTLC_SCRIPT_WEIGHT}; -use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface, FeeEstimator, ConfirmationTarget}; +use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface, FeeEstimator, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT}; use chain::transaction::OutPoint; use chain::keysinterface::SpendableOutputDescriptor; use util::logger::Logger; @@ -636,7 +636,7 @@ pub struct ChannelMonitor { } macro_rules! subtract_high_prio_fee { - ($self: ident, $fee_estimator: expr, $value: expr, $predicted_weight: expr, $spent_txid: expr, $used_feerate: expr) => { + ($self: ident, $fee_estimator: expr, $value: expr, $predicted_weight: expr, $used_feerate: expr) => { { $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority); let mut fee = $used_feerate * ($predicted_weight as u64) / 1000; @@ -647,18 +647,18 @@ macro_rules! subtract_high_prio_fee { $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background); fee = $used_feerate * ($predicted_weight as u64) / 1000; if $value <= fee { - log_error!($self, "Failed to generate an on-chain punishment tx spending {} as even low priority fee ({} sat) was more than the entire claim balance ({} sat)", - $spent_txid, fee, $value); + log_error!($self, "Failed to generate an on-chain punishment tx as even low priority fee ({} sat) was more than the entire claim balance ({} sat)", + fee, $value); false } else { - log_warn!($self, "Used low priority fee for on-chain punishment tx spending {} as high priority fee was more than the entire claim balance ({} sat)", - $spent_txid, $value); + log_warn!($self, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)", + $value); $value -= fee; true } } else { - log_warn!($self, "Used medium priority fee for on-chain punishment tx spending {} as high priority fee was more than the entire claim balance ({} sat)", - $spent_txid, $value); + log_warn!($self, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)", + $value); $value -= fee; true } @@ -1534,7 +1534,7 @@ impl ChannelMonitor { let predicted_weight = single_htlc_tx.get_weight() + Self::get_witnesses_weight(&[if htlc.offered { InputDescriptors::RevokedOfferedHTLC } else { InputDescriptors::RevokedReceivedHTLC }]); let height_timer = Self::get_height_timer(height, htlc.cltv_expiry); let mut used_feerate; - if subtract_high_prio_fee!(self, fee_estimator, single_htlc_tx.output[0].value, predicted_weight, tx.txid(), used_feerate) { + if subtract_high_prio_fee!(self, fee_estimator, single_htlc_tx.output[0].value, predicted_weight, used_feerate) { let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx); let (redeemscript, revocation_key) = sign_input!(sighash_parts, single_htlc_tx.input[0], Some(idx), htlc.amount_msat / 1000); assert!(predicted_weight >= single_htlc_tx.get_weight()); @@ -1612,7 +1612,7 @@ impl ChannelMonitor { let predicted_weight = spend_tx.get_weight() + Self::get_witnesses_weight(&inputs_desc[..]); let mut used_feerate; - if !subtract_high_prio_fee!(self, fee_estimator, spend_tx.output[0].value, predicted_weight, tx.txid(), used_feerate) { + if !subtract_high_prio_fee!(self, fee_estimator, spend_tx.output[0].value, predicted_weight, used_feerate) { return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs); } @@ -1816,7 +1816,7 @@ impl ChannelMonitor { let predicted_weight = single_htlc_tx.get_weight() + Self::get_witnesses_weight(&[if htlc.offered { InputDescriptors::OfferedHTLC } else { InputDescriptors::ReceivedHTLC }]); let height_timer = Self::get_height_timer(height, htlc.cltv_expiry); let mut used_feerate; - if subtract_high_prio_fee!(self, fee_estimator, single_htlc_tx.output[0].value, predicted_weight, tx.txid(), used_feerate) { + if subtract_high_prio_fee!(self, fee_estimator, single_htlc_tx.output[0].value, predicted_weight, used_feerate) { let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx); let (redeemscript, htlc_key) = sign_input!(sighash_parts, single_htlc_tx.input[0], htlc.amount_msat / 1000, payment_preimage.0.to_vec()); assert!(predicted_weight >= single_htlc_tx.get_weight()); @@ -1860,7 +1860,7 @@ impl ChannelMonitor { let predicted_weight = timeout_tx.get_weight() + Self::get_witnesses_weight(&[InputDescriptors::ReceivedHTLC]); let height_timer = Self::get_height_timer(height, htlc.cltv_expiry); let mut used_feerate; - if subtract_high_prio_fee!(self, fee_estimator, timeout_tx.output[0].value, predicted_weight, tx.txid(), used_feerate) { + if subtract_high_prio_fee!(self, fee_estimator, timeout_tx.output[0].value, predicted_weight, used_feerate) { let sighash_parts = bip143::SighashComponents::new(&timeout_tx); let (redeemscript, htlc_key) = sign_input!(sighash_parts, timeout_tx.input[0], htlc.amount_msat / 1000, vec![0]); assert!(predicted_weight >= timeout_tx.get_weight()); @@ -1894,7 +1894,7 @@ impl ChannelMonitor { let predicted_weight = spend_tx.get_weight() + Self::get_witnesses_weight(&inputs_desc[..]); let mut used_feerate; - if !subtract_high_prio_fee!(self, fee_estimator, spend_tx.output[0].value, predicted_weight, tx.txid(), used_feerate) { + if !subtract_high_prio_fee!(self, fee_estimator, spend_tx.output[0].value, predicted_weight, used_feerate) { return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs); } @@ -2004,7 +2004,7 @@ impl ChannelMonitor { }; let predicted_weight = spend_tx.get_weight() + Self::get_witnesses_weight(&[InputDescriptors::RevokedOutput]); let mut used_feerate; - if !subtract_high_prio_fee!(self, fee_estimator, spend_tx.output[0].value, predicted_weight, tx.txid(), used_feerate) { + if !subtract_high_prio_fee!(self, fee_estimator, spend_tx.output[0].value, predicted_weight, used_feerate) { return (None, None); } @@ -2288,6 +2288,7 @@ impl ChannelMonitor { let mut watch_outputs = Vec::new(); let mut spendable_outputs = Vec::new(); let mut htlc_updated = Vec::new(); + let mut bump_candidates = Vec::new(); for tx in txn_matched { if tx.input.len() == 1 { // Assuming our keys were not leaked (in which case we're screwed no matter what), @@ -2354,20 +2355,17 @@ impl ChannelMonitor { for inp in &tx.input { if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&inp.previous_output) { // If outpoint has claim request pending on it... - if let Some(claim_material) = self.pending_claim_requests.get(&ancestor_claimable_txid.0) { + if let Some(claim_material) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) { //... we need to verify equality between transaction outpoints and claim request // outpoints to know if transaction is the original claim or a bumped one issued // by us. - let mut set_equality = true; - if claim_material.per_input_material.len() != tx.input.len() { - set_equality = false; - } + let mut claimed_outpoints = Vec::new(); for (claim_inp, tx_inp) in claim_material.per_input_material.keys().zip(tx.input.iter()) { if *claim_inp != tx_inp.previous_output { - set_equality = false; + claimed_outpoints.push(tx_inp.previous_output.clone()); } } - if set_equality { // If true, register claim request to be removed after reaching a block security height + if claimed_outpoints.len() == 0 && claim_material.per_input_material.len() == tx.input.len() { // If true, register claim request to be removed after reaching a block security height match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) { hash_map::Entry::Occupied(_) => {}, hash_map::Entry::Vacant(entry) => { @@ -2375,7 +2373,13 @@ impl ChannelMonitor { } } } else { // If false, generate new claim request with update outpoint set - //TODO: use bump engine + for already_claimed in claimed_outpoints { + claim_material.per_input_material.remove(&already_claimed); + } + // Avoid bump engine using inaccurate feerate due to new transaction size + claim_material.feerate_previous = 0; + //TODO: recompute soonest_timelock to avoid wasting a bit on fees + bump_candidates.push((ancestor_claimable_txid.0.clone(), claim_material.clone())); } } else { panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map"); @@ -2427,6 +2431,21 @@ impl ChannelMonitor { } } } + for (ancestor_claim_txid, ref mut cached_claim_datas) in self.pending_claim_requests.iter_mut() { + if cached_claim_datas.height_timer == height { + bump_candidates.push((ancestor_claim_txid.clone(), cached_claim_datas.clone())); + } + } + for &mut (_, ref mut cached_claim_datas) in bump_candidates.iter_mut() { + if let Some((new_timer, new_feerate, bump_tx)) = self.bump_claim_tx(height, &cached_claim_datas, fee_estimator) { + cached_claim_datas.height_timer = new_timer; + cached_claim_datas.feerate_previous = new_feerate; + broadcaster.broadcast_transaction(&bump_tx); + } + } + for (ancestor_claim_txid, cached_claim_datas) in bump_candidates.drain(..) { + self.pending_claim_requests.insert(ancestor_claim_txid, cached_claim_datas); + } self.last_block_hash = block_hash.clone(); (watch_outputs, spendable_outputs, htlc_updated) } @@ -2640,6 +2659,126 @@ impl ChannelMonitor { } htlc_updated } + + /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize coutnerparty onchain) lays on the assumption of claim transactions getting confirmed before timelock expiration + /// (CSV or CLTV following cases). In case of high-fee spikes, claim tx may stuck in the mempool, so you need to bump its feerate quickly using Replace-By-Fee or Child-Pay-For-Parent. + fn bump_claim_tx(&self, height: u32, cached_claim_datas: &ClaimTxBumpMaterial, fee_estimator: &FeeEstimator) -> Option<(u32, u64, Transaction)> { + if cached_claim_datas.per_input_material.len() == 0 { return None } // But don't prune pending claiming request yet, we may have to resurrect HTLCs + let mut inputs = Vec::new(); + for outp in cached_claim_datas.per_input_material.keys() { + inputs.push(TxIn { + previous_output: *outp, + script_sig: Script::new(), + sequence: 0xfffffffd, + witness: Vec::new(), + }); + } + let mut bumped_tx = Transaction { + version: 2, + lock_time: 0, + input: inputs, + output: vec![TxOut { + script_pubkey: self.destination_script.clone(), + value: 0 + }], + }; + + macro_rules! RBF_bump { + ($amount: expr, $old_feerate: expr, $fee_estimator: expr, $predicted_weight: expr) => { + { + let mut used_feerate; + // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee... + let new_fee = if $old_feerate < $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) { + let mut value = $amount; + if subtract_high_prio_fee!(self, $fee_estimator, value, $predicted_weight, used_feerate) { + // Overflow check is done in subtract_high_prio_fee + $amount - value + } else { + log_trace!(self, "Can't new-estimation bump new claiming tx, amount {} is too small", $amount); + return None; + } + // ...else just increase the previous feerate by 25% (because that's a nice number) + } else { + let fee = $old_feerate * $predicted_weight / 750; + if $amount <= fee { + log_trace!(self, "Can't 25% bump new claiming tx, amount {} is too small", $amount); + return None; + } + fee + }; + + let previous_fee = $old_feerate * $predicted_weight / 1000; + let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * $predicted_weight / 1000; + // BIP 125 Opt-in Full Replace-by-Fee Signaling + // * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions. + // * 4. The replacement transaction must also pay for its own bandwidth at or above the rate set by the node's minimum relay fee setting. + let new_fee = if new_fee < previous_fee + min_relay_fee { + new_fee + previous_fee + min_relay_fee - new_fee + } else { + new_fee + }; + Some((new_fee, new_fee * 1000 / $predicted_weight)) + } + } + } + + let new_timer = Self::get_height_timer(height, cached_claim_datas.soonest_timelock); + let mut inputs_witnesses_weight = 0; + let mut amt = 0; + for per_outp_material in cached_claim_datas.per_input_material.values() { + match per_outp_material { + &InputMaterial::Revoked { ref script, ref is_htlc, ref amount, .. } => { + inputs_witnesses_weight += Self::get_witnesses_weight(if !is_htlc { &[InputDescriptors::RevokedOutput] } else if script.len() == OFFERED_HTLC_SCRIPT_WEIGHT { &[InputDescriptors::RevokedOfferedHTLC] } else if script.len() == ACCEPTED_HTLC_SCRIPT_WEIGHT { &[InputDescriptors::RevokedReceivedHTLC] } else { &[] }); + amt += *amount; + }, + &InputMaterial::RemoteHTLC { .. } => { }, + &InputMaterial::LocalHTLC { .. } => { return None; } + } + } + + let predicted_weight = bumped_tx.get_weight() + inputs_witnesses_weight; + let new_feerate; + if let Some((new_fee, feerate)) = RBF_bump!(amt, cached_claim_datas.feerate_previous, fee_estimator, predicted_weight as u64) { + // If new computed fee is superior at the whole claimable amount burn all in fees + if new_fee > amt { + bumped_tx.output[0].value = 0; + } else { + bumped_tx.output[0].value = amt - new_fee; + } + new_feerate = feerate; + } else { + return None; + } + assert!(new_feerate != 0); + + for (i, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() { + match per_outp_material { + &InputMaterial::Revoked { ref script, ref pubkey, ref key, ref is_htlc, ref amount } => { + let sighash_parts = bip143::SighashComponents::new(&bumped_tx); + let sighash = hash_to_message!(&sighash_parts.sighash_all(&bumped_tx.input[i], &script, *amount)[..]); + let sig = self.secp_ctx.sign(&sighash, &key); + bumped_tx.input[i].witness.push(sig.serialize_der().to_vec()); + bumped_tx.input[i].witness[0].push(SigHashType::All as u8); + if *is_htlc { + bumped_tx.input[i].witness.push(pubkey.unwrap().clone().serialize().to_vec()); + } else { + bumped_tx.input[i].witness.push(vec!(1)); + } + bumped_tx.input[i].witness.push(script.clone().into_bytes()); + log_trace!(self, "Going to broadcast bumped Penalty Transaction {} claiming revoked {} output {} from {} with new feerate {}", bumped_tx.txid(), if !is_htlc { "to_local" } else if script.len() == OFFERED_HTLC_SCRIPT_WEIGHT { "offered" } else if script.len() == ACCEPTED_HTLC_SCRIPT_WEIGHT { "received" } else { "" }, outp.vout, outp.txid, new_feerate); + }, + &InputMaterial::RemoteHTLC { .. } => {}, + &InputMaterial::LocalHTLC { .. } => { + //TODO : Given that Local Commitment Transaction and HTLC-Timeout/HTLC-Success are counter-signed by peer, we can't + // RBF them. Need a Lightning specs change and package relay modification : + // https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2018-November/016518.html + return None; + } + } + } + assert!(predicted_weight >= bumped_tx.get_weight()); + Some((new_timer, new_feerate, bumped_tx)) + } } const MAX_ALLOC_SIZE: usize = 64*1024;