Implement dynamic height timer for bump candidates txn
[rust-lightning] / src / ln / channelmonitor.rs
index f6d741afa10abfecfc64706ab13d6e2ae8a0bfed..5dddd1e1557db9e9300ba9cf8d65c086bf2702bc 100644 (file)
@@ -460,8 +460,10 @@ pub struct ChannelMonitor {
        // Used to track outpoint in the process of being claimed by our transactions. We need to scan all transactions
        // for inputs spending this. If height timer (u32) is expired and claim tx hasn't reached enough confirmations
        // before, use TxMaterial to regenerate a new claim tx with a satoshis-per-1000-weight-units higher than last
-       // one (u64).
-       our_claim_txn_waiting_first_conf: HashMap<BitcoinOutPoint, (u32, TxMaterial, u64)>,
+       // one (u64), if timelock expiration (u32) is near, decrease height timer, the in-between bumps delay.
+       // Last field cached (u32) is height of outpoint confirmation, which is needed to flush this tracker
+       // in case of reorgs, given block timer are scaled on timer expiration we can't deduce from it original height.
+       our_claim_txn_waiting_first_conf: HashMap<BitcoinOutPoint, (u32, TxMaterial, u64, u32, u32)>,
 
        // Used to track onchain events, i.e transactions parts of channels confirmed on chain, on which
        // we have to take actions once they reach enough confs. Key is a block height timer, i.e we enforce
@@ -624,6 +626,15 @@ impl ChannelMonitor {
                tx_weight
        }
 
+       fn get_height_timer(current_height: u32, timelock_expiration: u32) -> u32 {
+               if timelock_expiration <= current_height || timelock_expiration - current_height <= 3 {
+                       return current_height + 1
+               } else if timelock_expiration - current_height <= 15 {
+                       return current_height + 3
+               }
+               current_height + 15
+       }
+
        #[inline]
        fn place_secret(idx: u64) -> u8 {
                for i in 0..48 {
@@ -1129,6 +1140,8 @@ impl ChannelMonitor {
                                }
                        }
                        writer.write_all(&byte_utils::be64_to_array(claim_tx_data.2))?;
+                       writer.write_all(&byte_utils::be32_to_array(claim_tx_data.3))?;
+                       writer.write_all(&byte_utils::be32_to_array(claim_tx_data.4))?;
                }
 
                writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
@@ -1283,7 +1296,7 @@ impl ChannelMonitor {
                                                witness: Vec::new(),
                                        });
                                        inputs_desc.push(InputDescriptors::RevokedOutput);
-                                       inputs_info.push((None, outp.value));
+                                       inputs_info.push((None, outp.value, self.our_to_self_delay as u32));
                                        total_value += outp.value;
                                } else if Some(&outp.script_pubkey) == local_payment_p2wpkh.as_ref() {
                                        spendable_outputs.push(SpendableOutputDescriptor::DynamicOutputP2WPKH {
@@ -1347,7 +1360,7 @@ impl ChannelMonitor {
                                                if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
                                                        inputs.push(input);
                                                        inputs_desc.push(if htlc.offered { InputDescriptors::RevokedOfferedHTLC } else { InputDescriptors::RevokedReceivedHTLC });
-                                                       inputs_info.push((Some(idx), tx.output[transaction_output_index as usize].value));
+                                                       inputs_info.push((Some(idx), tx.output[transaction_output_index as usize].value, htlc.cltv_expiry));
                                                        total_value += tx.output[transaction_output_index as usize].value;
                                                } else {
                                                        let mut single_htlc_tx = Transaction {
@@ -1360,6 +1373,7 @@ 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) {
                                                                let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
@@ -1367,7 +1381,7 @@ impl ChannelMonitor {
                                                                assert!(predicted_weight >= single_htlc_tx.get_weight());
                                                                match self.our_claim_txn_waiting_first_conf.entry(single_htlc_tx.input[0].previous_output.clone()) {
                                                                        hash_map::Entry::Occupied(_) => {},
-                                                                       hash_map::Entry::Vacant(entry) => { entry.insert((height + 3, TxMaterial::Revoked { script: redeemscript, pubkey: Some(revocation_pubkey), key: revocation_key, is_htlc: true, amount: htlc.amount_msat / 1000 }, used_feerate)); }
+                                                                       hash_map::Entry::Vacant(entry) => { entry.insert((height_timer, TxMaterial::Revoked { script: redeemscript, pubkey: Some(revocation_pubkey), key: revocation_key, is_htlc: true, amount: htlc.amount_msat / 1000 }, used_feerate, htlc.cltv_expiry, height)); }
                                                                }
                                                                txn_to_broadcast.push(single_htlc_tx);
                                                        }
@@ -1444,9 +1458,10 @@ impl ChannelMonitor {
 
                        for (input, info) in spend_tx.input.iter_mut().zip(inputs_info.iter()) {
                                let (redeemscript, revocation_key) = sign_input!(sighash_parts, input, info.0, info.1);
+                               let height_timer = Self::get_height_timer(height, info.2);
                                match self.our_claim_txn_waiting_first_conf.entry(input.previous_output.clone()) {
                                        hash_map::Entry::Occupied(_) => {},
-                                       hash_map::Entry::Vacant(entry) => { entry.insert((height + 3, TxMaterial::Revoked { script: redeemscript, pubkey: if info.0.is_some() { Some(revocation_pubkey) } else { None }, key: revocation_key, is_htlc: if info.0.is_some() { true } else { false }, amount: info.1 }, used_feerate)); }
+                                       hash_map::Entry::Vacant(entry) => { entry.insert((height_timer, TxMaterial::Revoked { script: redeemscript, pubkey: if info.0.is_some() { Some(revocation_pubkey) } else { None }, key: revocation_key, is_htlc: if info.0.is_some() { true } else { false }, amount: info.1 }, used_feerate, if !info.0.is_some() { height + info.2 } else { info.2 }, height)); }
                                }
                        }
                        assert!(predicted_weight >= spend_tx.get_weight());
@@ -1610,7 +1625,7 @@ impl ChannelMonitor {
                                                                if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
                                                                        inputs.push(input);
                                                                        inputs_desc.push(if htlc.offered { InputDescriptors::OfferedHTLC } else { InputDescriptors::ReceivedHTLC });
-                                                                       inputs_info.push((payment_preimage, tx.output[transaction_output_index as usize].value));
+                                                                       inputs_info.push((payment_preimage, tx.output[transaction_output_index as usize].value, htlc.cltv_expiry));
                                                                        total_value += tx.output[transaction_output_index as usize].value;
                                                                } else {
                                                                        let mut single_htlc_tx = Transaction {
@@ -1623,6 +1638,7 @@ 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) {
                                                                                let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
@@ -1634,7 +1650,7 @@ impl ChannelMonitor {
                                                                                });
                                                                                match self.our_claim_txn_waiting_first_conf.entry(single_htlc_tx.input[0].previous_output.clone()) {
                                                                                        hash_map::Entry::Occupied(_) => {},
-                                                                                       hash_map::Entry::Vacant(entry) => { entry.insert((height + 3, TxMaterial::RemoteHTLC { script: redeemscript, key: htlc_key, preimage: Some(*payment_preimage), amount: htlc.amount_msat / 1000 }, used_feerate)); }
+                                                                                       hash_map::Entry::Vacant(entry) => { entry.insert((height_timer, TxMaterial::RemoteHTLC { script: redeemscript, key: htlc_key, preimage: Some(*payment_preimage), amount: htlc.amount_msat / 1000 }, used_feerate, htlc.cltv_expiry, height)); }
                                                                                }
                                                                                txn_to_broadcast.push(single_htlc_tx);
                                                                        }
@@ -1662,6 +1678,7 @@ 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) {
                                                                        let sighash_parts = bip143::SighashComponents::new(&timeout_tx);
@@ -1670,7 +1687,7 @@ impl ChannelMonitor {
                                                                        //TODO: track SpendableOutputDescriptor
                                                                        match self.our_claim_txn_waiting_first_conf.entry(timeout_tx.input[0].previous_output.clone()) {
                                                                                hash_map::Entry::Occupied(_) => {},
-                                                                               hash_map::Entry::Vacant(entry) => { entry.insert((height + 3, TxMaterial::RemoteHTLC { script : redeemscript, key: htlc_key, preimage: None, amount: htlc.amount_msat / 1000 }, used_feerate)); }
+                                                                               hash_map::Entry::Vacant(entry) => { entry.insert((height_timer, TxMaterial::RemoteHTLC { script : redeemscript, key: htlc_key, preimage: None, amount: htlc.amount_msat / 1000 }, used_feerate, htlc.cltv_expiry, height)); }
                                                                        }
                                                                }
                                                                txn_to_broadcast.push(timeout_tx);
@@ -1702,9 +1719,10 @@ impl ChannelMonitor {
 
                                        for (input, info) in spend_tx.input.iter_mut().zip(inputs_info.iter()) {
                                                let (redeemscript, htlc_key) = sign_input!(sighash_parts, input, info.1, (info.0).0.to_vec());
+                                               let height_timer = Self::get_height_timer(height, info.2);
                                                match self.our_claim_txn_waiting_first_conf.entry(input.previous_output.clone()) {
                                                        hash_map::Entry::Occupied(_) => {},
-                                                       hash_map::Entry::Vacant(entry) => { entry.insert((height + 3, TxMaterial::RemoteHTLC { script: redeemscript, key: htlc_key, preimage: Some(*(info.0)), amount: info.1}, used_feerate)); }
+                                                       hash_map::Entry::Vacant(entry) => { entry.insert((height_timer, TxMaterial::RemoteHTLC { script: redeemscript, key: htlc_key, preimage: Some(*(info.0)), amount: info.1}, used_feerate, info.2, height)); }
                                                }
                                        }
                                        assert!(predicted_weight >= spend_tx.get_weight());
@@ -1808,15 +1826,16 @@ impl ChannelMonitor {
                        assert!(predicted_weight >= spend_tx.get_weight());
                        let outpoint = BitcoinOutPoint { txid: spend_tx.txid(), vout: 0 };
                        let output = spend_tx.output[0].clone();
+                       let height_timer = Self::get_height_timer(height, self.their_to_self_delay.unwrap() as u32); // We can safely unwrap given we are past channel opening
                        match self.our_claim_txn_waiting_first_conf.entry(spend_tx.input[0].previous_output.clone()) {
                                hash_map::Entry::Occupied(_) => {},
-                               hash_map::Entry::Vacant(entry) => { entry.insert((height + 3, TxMaterial::Revoked { script: redeemscript, pubkey: None, key: revocation_key, is_htlc: false, amount: tx.output[0].value }, used_feerate)); }
+                               hash_map::Entry::Vacant(entry) => { entry.insert((height_timer, TxMaterial::Revoked { script: redeemscript, pubkey: None, key: revocation_key, is_htlc: false, amount: tx.output[0].value }, used_feerate, height + self.our_to_self_delay as u32, height)); }
                        }
                        (Some(spend_tx), Some(SpendableOutputDescriptor::StaticOutput { outpoint, output }))
                } else { (None, None) }
        }
 
-       fn broadcast_by_local_state(&self, local_tx: &LocalSignedTx, per_commitment_point: &Option<PublicKey>, delayed_payment_base_key: &Option<SecretKey>, height: u32) -> (Vec<Transaction>, Vec<SpendableOutputDescriptor>, Vec<TxOut>, Vec<(BitcoinOutPoint, (u32, TxMaterial, u64))>) {
+       fn broadcast_by_local_state(&self, local_tx: &LocalSignedTx, per_commitment_point: &Option<PublicKey>, delayed_payment_base_key: &Option<SecretKey>, height: u32) -> (Vec<Transaction>, Vec<SpendableOutputDescriptor>, Vec<TxOut>, Vec<(BitcoinOutPoint, (u32, TxMaterial, u64, u32, u32))>) {
                let mut res = Vec::with_capacity(local_tx.htlc_outputs.len());
                let mut spendable_outputs = Vec::with_capacity(local_tx.htlc_outputs.len());
                let mut watch_outputs = Vec::with_capacity(local_tx.htlc_outputs.len());
@@ -1869,7 +1888,8 @@ impl ChannelMonitor {
                                                htlc_timeout_tx.input[0].witness.push(htlc_script.clone().into_bytes());
 
                                                add_dynamic_output!(htlc_timeout_tx, 0);
-                                               pending_claims.push((htlc_timeout_tx.input[0].previous_output.clone(), (height + 3, TxMaterial::LocalHTLC { script: htlc_script, sigs: (*their_sig, *our_sig), preimage: None, amount: htlc.amount_msat / 1000}, 0)));
+                                               let height_timer = Self::get_height_timer(height, htlc.cltv_expiry);
+                                               pending_claims.push((htlc_timeout_tx.input[0].previous_output.clone(), (height_timer, TxMaterial::LocalHTLC { script: htlc_script, sigs: (*their_sig, *our_sig), preimage: None, amount: htlc.amount_msat / 1000}, 0, htlc.cltv_expiry, height)));
                                                res.push(htlc_timeout_tx);
                                        } else {
                                                if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
@@ -1888,7 +1908,8 @@ impl ChannelMonitor {
                                                        htlc_success_tx.input[0].witness.push(htlc_script.clone().into_bytes());
 
                                                        add_dynamic_output!(htlc_success_tx, 0);
-                                                       pending_claims.push((htlc_success_tx.input[0].previous_output.clone(), (height + 3, TxMaterial::LocalHTLC { script: htlc_script, sigs: (*their_sig, *our_sig), preimage: Some(*payment_preimage), amount: htlc.amount_msat / 1000}, 0)));
+                                                       let height_timer = Self::get_height_timer(height, htlc.cltv_expiry);
+                                                       pending_claims.push((htlc_success_tx.input[0].previous_output.clone(), (height_timer, TxMaterial::LocalHTLC { script: htlc_script, sigs: (*their_sig, *our_sig), preimage: Some(*payment_preimage), amount: htlc.amount_msat / 1000}, 0, htlc.cltv_expiry, height)));
                                                        res.push(htlc_success_tx);
                                                }
                                        }
@@ -2190,7 +2211,7 @@ impl ChannelMonitor {
                        //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
                        //- our claim tx on a commitment tx output
                }
-               self.our_claim_txn_waiting_first_conf.retain(|_, ref mut v| if v.0 == height + 3 { false } else { true });
+               self.our_claim_txn_waiting_first_conf.retain(|_, ref mut v| if v.3 == height { false } else { true });
                self.last_block_hash = block_hash.clone();
        }
 
@@ -2659,7 +2680,9 @@ impl<R: ::std::io::Read> ReadableArgs<R, Arc<Logger>> for (Sha256dHash, ChannelM
                                _ => return Err(DecodeError::InvalidValue),
                        };
                        let last_fee = Readable::read(reader)?;
-                       our_claim_txn_waiting_first_conf.insert(outpoint, (height_target, tx_material, last_fee));
+                       let timelock_expiration = Readable::read(reader)?;
+                       let height = Readable::read(reader)?;
+                       our_claim_txn_waiting_first_conf.insert(outpoint, (height_target, tx_material, last_fee, timelock_expiration, height));
                }
 
                let waiting_threshold_conf_len: u64 = Readable::read(reader)?;