Move our_claim_txn_waiting_first_conf to pending_claim_requests
authorAntoine Riard <ariard@student.42.fr>
Tue, 10 Dec 2019 03:18:20 +0000 (22:18 -0500)
committerMatt Corallo <git@bluematt.me>
Tue, 10 Dec 2019 03:22:35 +0000 (22:22 -0500)
Add claimable_outpoints maps.

Both structures are tied and should ensure their mutual consistency.

Pending_claim_requests is cached by original claim txid. Medatada
and per input material should be constant between bumped transactions,
only change should be partial-claiming of outpoints set and block
reorgs.

Due to RBF rules, if an input has been part of an aggregate tx
at first claim try, if we want the bumped tx to land nicely
in the mempool, inputs should be distributed in multiple
bumped tx but still be aggregate in a new bumped tx.

lightning/src/ln/channelmonitor.rs

index a53a562b88fa6abe3c943d6ef6c642d09e78a1fb..72e8e210a31f23879c40ecfe9e132ada2df433c7 100644 (file)
@@ -374,7 +374,7 @@ enum InputDescriptors {
 /// to generate a tx to push channel state forward, we cache outpoint-solving tx material to build
 /// a new bumped one in case of lenghty confirmation delay
 #[derive(Clone, PartialEq)]
-enum TxMaterial {
+enum InputMaterial {
        Revoked {
                script: Script,
                pubkey: Option<PublicKey>,
@@ -396,6 +396,93 @@ enum TxMaterial {
        }
 }
 
+impl Writeable for InputMaterial  {
+       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
+               match self {
+                       &InputMaterial::Revoked { ref script, ref pubkey, ref key, ref is_htlc, ref amount} => {
+                               writer.write_all(&[0; 1])?;
+                               script.write(writer)?;
+                               pubkey.write(writer)?;
+                               writer.write_all(&key[..])?;
+                               if *is_htlc {
+                                       writer.write_all(&[0; 1])?;
+                               } else {
+                                       writer.write_all(&[1; 1])?;
+                               }
+                               writer.write_all(&byte_utils::be64_to_array(*amount))?;
+                       },
+                       &InputMaterial::RemoteHTLC { ref script, ref key, ref preimage, ref amount } => {
+                               writer.write_all(&[1; 1])?;
+                               script.write(writer)?;
+                               key.write(writer)?;
+                               preimage.write(writer)?;
+                               writer.write_all(&byte_utils::be64_to_array(*amount))?;
+                       },
+                       &InputMaterial::LocalHTLC { ref script, ref sigs, ref preimage, ref amount } => {
+                               writer.write_all(&[2; 1])?;
+                               script.write(writer)?;
+                               sigs.0.write(writer)?;
+                               sigs.1.write(writer)?;
+                               preimage.write(writer)?;
+                               writer.write_all(&byte_utils::be64_to_array(*amount))?;
+                       }
+               }
+               Ok(())
+       }
+}
+
+impl<R: ::std::io::Read> Readable<R> for InputMaterial {
+       fn read(reader: &mut R) -> Result<Self, DecodeError> {
+               let input_material = match <u8 as Readable<R>>::read(reader)? {
+                       0 => {
+                               let script = Readable::read(reader)?;
+                               let pubkey = Readable::read(reader)?;
+                               let key = Readable::read(reader)?;
+                               let is_htlc = match <u8 as Readable<R>>::read(reader)? {
+                                       0 => true,
+                                       1 => false,
+                                       _ => return Err(DecodeError::InvalidValue),
+                               };
+                               let amount = Readable::read(reader)?;
+                               InputMaterial::Revoked {
+                                       script,
+                                       pubkey,
+                                       key,
+                                       is_htlc,
+                                       amount
+                               }
+                       },
+                       1 => {
+                               let script = Readable::read(reader)?;
+                               let key = Readable::read(reader)?;
+                               let preimage = Readable::read(reader)?;
+                               let amount = Readable::read(reader)?;
+                               InputMaterial::RemoteHTLC {
+                                       script,
+                                       key,
+                                       preimage,
+                                       amount
+                               }
+                       },
+                       2 => {
+                               let script = Readable::read(reader)?;
+                               let their_sig = Readable::read(reader)?;
+                               let our_sig = Readable::read(reader)?;
+                               let preimage = Readable::read(reader)?;
+                               let amount = Readable::read(reader)?;
+                               InputMaterial::LocalHTLC {
+                                       script,
+                                       sigs: (their_sig, our_sig),
+                                       preimage,
+                                       amount
+                               }
+                       }
+                       _ => return Err(DecodeError::InvalidValue),
+               };
+               Ok(input_material)
+       }
+}
+
 /// 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)]
@@ -403,7 +490,7 @@ enum OnchainEvent {
        /// Outpoint under claim process by our own tx, once this one get enough confirmations, we remove it from
        /// bump-txn candidate buffer.
        Claim {
-               outpoint: BitcoinOutPoint,
+               claim_request: Sha256dHash,
        },
        /// HTLC output getting solved by a timeout, at maturation we pass upstream payment source information to solve
        /// inbound HTLC in backward channel. Note, in case of preimage, we pass info to upstream without delay as we can
@@ -413,6 +500,51 @@ enum OnchainEvent {
        },
 }
 
+/// Higher-level cache structure needed to re-generate bumped claim txn if needed
+#[derive(Clone, PartialEq)]
+struct ClaimTxBumpMaterial {
+       // At every block tick, used to check if pending claiming tx is taking too
+       // much time for confirmation and we need to bump it.
+       height_timer: u32,
+       // Tracked in case of reorg to wipe out now-superflous bump material
+       feerate_previous: u64,
+       // Soonest timelocks among set of outpoints claimed, used to compute
+       // a priority of not feerate
+       soonest_timelock: u32,
+       // Cache of script, pubkey, sig or key to solve claimable outputs scriptpubkey.
+       per_input_material: HashMap<BitcoinOutPoint, InputMaterial>,
+}
+
+impl Writeable for ClaimTxBumpMaterial  {
+       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
+               writer.write_all(&byte_utils::be32_to_array(self.height_timer))?;
+               writer.write_all(&byte_utils::be64_to_array(self.feerate_previous))?;
+               writer.write_all(&byte_utils::be32_to_array(self.soonest_timelock))?;
+               writer.write_all(&byte_utils::be64_to_array(self.per_input_material.len() as u64))?;
+               for (outp, tx_material) in self.per_input_material.iter() {
+                       outp.write(writer)?;
+                       tx_material.write(writer)?;
+               }
+               Ok(())
+       }
+}
+
+impl<R: ::std::io::Read> Readable<R> for ClaimTxBumpMaterial {
+       fn read(reader: &mut R) -> Result<Self, DecodeError> {
+               let height_timer = Readable::read(reader)?;
+               let feerate_previous = Readable::read(reader)?;
+               let soonest_timelock = Readable::read(reader)?;
+               let per_input_material_len: u64 = Readable::read(reader)?;
+               let mut per_input_material = HashMap::with_capacity(cmp::min(per_input_material_len as usize, MAX_ALLOC_SIZE / 128));
+               for _ in 0 ..per_input_material_len {
+                       let outpoint = Readable::read(reader)?;
+                       let input_material = Readable::read(reader)?;
+                       per_input_material.insert(outpoint, input_material);
+               }
+               Ok(Self { height_timer, feerate_previous, soonest_timelock, per_input_material })
+       }
+}
+
 const SERIALIZATION_VERSION: u8 = 1;
 const MIN_SERIALIZATION_VERSION: u8 = 1;
 
@@ -467,13 +599,26 @@ pub struct ChannelMonitor {
        // scan every commitment transaction for that
        to_remote_rescue: Option<(Script, SecretKey)>,
 
-       // 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), 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 claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
+       // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
+       // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
+       // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
+       // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
+       // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
+       // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
+       // we need to regenerate new claim request we reduced set of stil-claimable outpoints.
+       // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
+       // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
+       // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
+       pending_claim_requests: HashMap<Sha256dHash, ClaimTxBumpMaterial>,
+
+       // Used to link outpoints claimed in a connected block to a pending claim request.
+       // Key is outpoint than monitor parsing has detected we have keys/scripts to claim
+       // Value is (pending claim request identifier, confirmation_block), identifier
+       // is txid of the initial claiming transaction and is immutable until outpoint is
+       // post-anti-reorg-delay solved, confirmaiton_block is used to erase entry if
+       // block with output gets disconnected.
+       claimable_outpoints: HashMap<BitcoinOutPoint, (Sha256dHash, 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
@@ -546,7 +691,8 @@ impl PartialEq for ChannelMonitor {
                        self.payment_preimages != other.payment_preimages ||
                        self.destination_script != other.destination_script ||
                        self.to_remote_rescue != other.to_remote_rescue ||
-                       self.our_claim_txn_waiting_first_conf != other.our_claim_txn_waiting_first_conf ||
+                       self.pending_claim_requests != other.pending_claim_requests ||
+                       self.claimable_outpoints != other.claimable_outpoints ||
                        self.onchain_events_waiting_threshold_conf != other.onchain_events_waiting_threshold_conf
                {
                        false
@@ -598,7 +744,9 @@ impl ChannelMonitor {
                        destination_script: destination_script,
                        to_remote_rescue: None,
 
-                       our_claim_txn_waiting_first_conf: HashMap::new(),
+                       pending_claim_requests: HashMap::new(),
+
+                       claimable_outpoints: HashMap::new(),
 
                        onchain_events_waiting_threshold_conf: HashMap::new(),
 
@@ -1142,42 +1290,17 @@ impl ChannelMonitor {
                        writer.write_all(&[0; 1])?;
                }
 
-               writer.write_all(&byte_utils::be64_to_array(self.our_claim_txn_waiting_first_conf.len() as u64))?;
-               for (ref outpoint, claim_tx_data) in self.our_claim_txn_waiting_first_conf.iter() {
-                       outpoint.write(writer)?;
-                       writer.write_all(&byte_utils::be32_to_array(claim_tx_data.0))?;
-                       match claim_tx_data.1 {
-                               TxMaterial::Revoked { ref script, ref pubkey, ref key, ref is_htlc, ref amount} => {
-                                       writer.write_all(&[0; 1])?;
-                                       script.write(writer)?;
-                                       pubkey.write(writer)?;
-                                       writer.write_all(&key[..])?;
-                                       if *is_htlc {
-                                               writer.write_all(&[0; 1])?;
-                                       } else {
-                                               writer.write_all(&[1; 1])?;
-                                       }
-                                       writer.write_all(&byte_utils::be64_to_array(*amount))?;
-                               },
-                               TxMaterial::RemoteHTLC { ref script, ref key, ref preimage, ref amount } => {
-                                       writer.write_all(&[1; 1])?;
-                                       script.write(writer)?;
-                                       key.write(writer)?;
-                                       preimage.write(writer)?;
-                                       writer.write_all(&byte_utils::be64_to_array(*amount))?;
-                               },
-                               TxMaterial::LocalHTLC { ref script, ref sigs, ref preimage, ref amount } => {
-                                       writer.write_all(&[2; 1])?;
-                                       script.write(writer)?;
-                                       sigs.0.write(writer)?;
-                                       sigs.1.write(writer)?;
-                                       preimage.write(writer)?;
-                                       writer.write_all(&byte_utils::be64_to_array(*amount))?;
-                               }
-                       }
-                       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.pending_claim_requests.len() as u64))?;
+               for (ref ancestor_claim_txid, claim_tx_data) in self.pending_claim_requests.iter() {
+                       ancestor_claim_txid.write(writer)?;
+                       claim_tx_data.write(writer)?;
+               }
+
+               writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
+               for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
+                       outp.write(writer)?;
+                       claim_and_height.0.write(writer)?;
+                       claim_and_height.1.write(writer)?;
                }
 
                writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
@@ -1186,9 +1309,9 @@ impl ChannelMonitor {
                        writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
                        for ev in events.iter() {
                                match *ev {
-                                       OnchainEvent::Claim { ref outpoint } => {
+                                       OnchainEvent::Claim { ref claim_request } => {
                                                writer.write_all(&[0; 1])?;
-                                               outpoint.write(writer)?;
+                                               claim_request.write(writer)?;
                                        },
                                        OnchainEvent::HTLCUpdate { ref htlc_update } => {
                                                writer.write_all(&[1; 1])?;
@@ -1416,9 +1539,11 @@ impl ChannelMonitor {
                                                                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());
                                                                log_trace!(self, "Outpoint {}:{} is being being claimed, if it doesn't succeed, a bumped claiming txn is going to be broadcast at height {}", single_htlc_tx.input[0].previous_output.txid, single_htlc_tx.input[0].previous_output.vout, height_timer);
-                                                               match self.our_claim_txn_waiting_first_conf.entry(single_htlc_tx.input[0].previous_output.clone()) {
+                                                               let mut per_input_material = HashMap::with_capacity(1);
+                                                               per_input_material.insert(single_htlc_tx.input[0].previous_output, InputMaterial::Revoked { script: redeemscript, pubkey: Some(revocation_pubkey), key: revocation_key, is_htlc: true, amount: htlc.amount_msat / 1000 });
+                                                               match self.pending_claim_requests.entry(single_htlc_tx.txid()) {
                                                                        hash_map::Entry::Occupied(_) => {},
-                                                                       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)); }
+                                                                       hash_map::Entry::Vacant(entry) => { entry.insert(ClaimTxBumpMaterial { height_timer, feerate_previous: used_feerate, soonest_timelock: htlc.cltv_expiry, per_input_material }); }
                                                                }
                                                                txn_to_broadcast.push(single_htlc_tx);
                                                        }
@@ -1493,15 +1618,27 @@ impl ChannelMonitor {
 
                        let sighash_parts = bip143::SighashComponents::new(&spend_tx);
 
+                       let mut per_input_material = HashMap::with_capacity(spend_tx.input.len());
+                       let mut soonest_timelock = ::std::u32::MAX;
+                       for info in inputs_info.iter() {
+                               if info.2 <= soonest_timelock {
+                                       soonest_timelock = info.2;
+                               }
+                       }
+                       let height_timer = Self::get_height_timer(height, soonest_timelock);
                        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);
                                log_trace!(self, "Outpoint {}:{} is being being claimed, if it doesn't succeed, a bumped claiming txn is going to be broadcast at height {}", input.previous_output.txid, input.previous_output.vout, height_timer);
-                               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_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)); }
+                               per_input_material.insert(input.previous_output, InputMaterial::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 });
+                               if info.2 < soonest_timelock {
+                                       soonest_timelock = info.2;
                                }
                        }
+                       match self.pending_claim_requests.entry(spend_tx.txid()) {
+                               hash_map::Entry::Occupied(_) => {},
+                               hash_map::Entry::Vacant(entry) => { entry.insert(ClaimTxBumpMaterial { height_timer, feerate_previous: used_feerate, soonest_timelock, per_input_material }); }
+                       }
+
                        assert!(predicted_weight >= spend_tx.get_weight());
 
                        spendable_outputs.push(SpendableOutputDescriptor::StaticOutput {
@@ -1688,9 +1825,11 @@ impl ChannelMonitor {
                                                                                                output: single_htlc_tx.output[0].clone(),
                                                                                        });
                                                                                        log_trace!(self, "Outpoint {}:{} is being being claimed, if it doesn't succeed, a bumped claiming txn is going to be broadcast at height {}", single_htlc_tx.input[0].previous_output.txid, single_htlc_tx.input[0].previous_output.vout, height_timer);
-                                                                                       match self.our_claim_txn_waiting_first_conf.entry(single_htlc_tx.input[0].previous_output.clone()) {
+                                                                                       let mut per_input_material = HashMap::with_capacity(1);
+                                                                                       per_input_material.insert(single_htlc_tx.input[0].previous_output, InputMaterial::RemoteHTLC { script: redeemscript, key: htlc_key, preimage: Some(*payment_preimage), amount: htlc.amount_msat / 1000 });
+                                                                                       match self.pending_claim_requests.entry(single_htlc_tx.txid()) {
                                                                                                hash_map::Entry::Occupied(_) => {},
-                                                                                               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)); }
+                                                                                               hash_map::Entry::Vacant(entry) => { entry.insert(ClaimTxBumpMaterial { height_timer, feerate_previous: used_feerate, soonest_timelock: htlc.cltv_expiry, per_input_material}); }
                                                                                        }
                                                                                        txn_to_broadcast.push(single_htlc_tx);
                                                                                }
@@ -1727,9 +1866,11 @@ impl ChannelMonitor {
                                                                        assert!(predicted_weight >= timeout_tx.get_weight());
                                                                        //TODO: track SpendableOutputDescriptor
                                                                        log_trace!(self, "Outpoint {}:{} is being being claimed, if it doesn't succeed, a bumped claiming txn is going to be broadcast at height {}", timeout_tx.input[0].previous_output.txid, timeout_tx.input[0].previous_output.vout, height_timer);
-                                                                       match self.our_claim_txn_waiting_first_conf.entry(timeout_tx.input[0].previous_output.clone()) {
+                                                                       let mut per_input_material = HashMap::with_capacity(1);
+                                                                       per_input_material.insert(timeout_tx.input[0].previous_output, InputMaterial::RemoteHTLC { script : redeemscript, key: htlc_key, preimage: None, amount: htlc.amount_msat / 1000 });
+                                                                       match self.pending_claim_requests.entry(timeout_tx.txid()) {
                                                                                hash_map::Entry::Occupied(_) => {},
-                                                                               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)); }
+                                                                               hash_map::Entry::Vacant(entry) => { entry.insert(ClaimTxBumpMaterial { height_timer, feerate_previous: used_feerate, soonest_timelock: htlc.cltv_expiry, per_input_material }); }
                                                                        }
                                                                }
                                                                txn_to_broadcast.push(timeout_tx);
@@ -1759,14 +1900,22 @@ impl ChannelMonitor {
 
                                        let sighash_parts = bip143::SighashComponents::new(&spend_tx);
 
+                                       let mut per_input_material = HashMap::with_capacity(spend_tx.input.len());
+                                       let mut soonest_timelock = ::std::u32::MAX;
+                                       for info in inputs_info.iter() {
+                                               if info.2 <= soonest_timelock {
+                                                       soonest_timelock = info.2;
+                                               }
+                                       }
+                                       let height_timer = Self::get_height_timer(height, soonest_timelock);
                                        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);
                                                log_trace!(self, "Outpoint {}:{} is being being claimed, if it doesn't succeed, a bumped claiming txn is going to be broadcast at height {}", input.previous_output.txid, input.previous_output.vout, height_timer);
-                                               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_timer, TxMaterial::RemoteHTLC { script: redeemscript, key: htlc_key, preimage: Some(*(info.0)), amount: info.1}, used_feerate, info.2, height)); }
-                                               }
+                                               per_input_material.insert(input.previous_output, InputMaterial::RemoteHTLC { script: redeemscript, key: htlc_key, preimage: Some(*(info.0)), amount: info.1});
+                                       }
+                                       match self.pending_claim_requests.entry(spend_tx.txid()) {
+                                               hash_map::Entry::Occupied(_) => {},
+                                               hash_map::Entry::Vacant(entry) => { entry.insert(ClaimTxBumpMaterial { height_timer, feerate_previous: used_feerate, soonest_timelock, per_input_material }); }
                                        }
                                        assert!(predicted_weight >= spend_tx.get_weight());
                                        spendable_outputs.push(SpendableOutputDescriptor::StaticOutput {
@@ -1881,15 +2030,17 @@ impl ChannelMonitor {
                        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
                        log_trace!(self, "Outpoint {}:{} is being being claimed, if it doesn't succeed, a bumped claiming txn is going to be broadcast at height {}", spend_tx.input[0].previous_output.txid, spend_tx.input[0].previous_output.vout, height_timer);
-                       match self.our_claim_txn_waiting_first_conf.entry(spend_tx.input[0].previous_output.clone()) {
+                       let mut per_input_material = HashMap::with_capacity(1);
+                       per_input_material.insert(spend_tx.input[0].previous_output, InputMaterial::Revoked { script: redeemscript, pubkey: None, key: revocation_key, is_htlc: false, amount: tx.output[0].value });
+                       match self.pending_claim_requests.entry(spend_tx.txid()) {
                                hash_map::Entry::Occupied(_) => {},
-                               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)); }
+                               hash_map::Entry::Vacant(entry) => { entry.insert(ClaimTxBumpMaterial { height_timer, feerate_previous: used_feerate, soonest_timelock: height + self.our_to_self_delay as u32, per_input_material }); }
                        }
                        (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, u32, u32))>) {
+       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<(Sha256dHash, ClaimTxBumpMaterial)>) {
                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());
@@ -1913,7 +2064,6 @@ impl ChannelMonitor {
                        }
                }
 
-
                let redeemscript = chan_utils::get_revokeable_redeemscript(&local_tx.revocation_key, self.their_to_self_delay.unwrap(), &local_tx.delayed_payment_key);
                let revokeable_p2wsh = redeemscript.to_v0_p2wsh();
                for (idx, output) in local_tx.tx.output.iter().enumerate() {
@@ -1943,7 +2093,10 @@ impl ChannelMonitor {
 
                                                add_dynamic_output!(htlc_timeout_tx, 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)));
+                                               let mut per_input_material = HashMap::with_capacity(1);
+                                               per_input_material.insert(htlc_timeout_tx.input[0].previous_output, InputMaterial::LocalHTLC { script: htlc_script, sigs: (*their_sig, *our_sig), preimage: None, amount: htlc.amount_msat / 1000});
+                                               log_trace!(self, "Outpoint {}:{} is being being claimed, if it doesn't succeed, a bumped claiming txn is going to be broadcast at height {}", htlc_timeout_tx.input[0].previous_output.vout, htlc_timeout_tx.input[0].previous_output.txid, height_timer);
+                                               pending_claims.push((htlc_timeout_tx.txid(), ClaimTxBumpMaterial { height_timer, feerate_previous: 0, soonest_timelock: htlc.cltv_expiry, per_input_material }));
                                                res.push(htlc_timeout_tx);
                                        } else {
                                                if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
@@ -1963,7 +2116,10 @@ impl ChannelMonitor {
 
                                                        add_dynamic_output!(htlc_success_tx, 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)));
+                                                       let mut per_input_material = HashMap::with_capacity(1);
+                                                       per_input_material.insert(htlc_success_tx.input[0].previous_output, InputMaterial::LocalHTLC { script: htlc_script, sigs: (*their_sig, *our_sig), preimage: Some(*payment_preimage), amount: htlc.amount_msat / 1000});
+                                                       log_trace!(self, "Outpoint {}:{} is being being claimed, if it doesn't succeed, a bumped claiming txn is going to be broadcast at height {}", htlc_success_tx.input[0].previous_output.vout, htlc_success_tx.input[0].previous_output.txid, height_timer);
+                                                       pending_claims.push((htlc_success_tx.txid(), ClaimTxBumpMaterial { height_timer, feerate_previous: 0, soonest_timelock: htlc.cltv_expiry, per_input_material }));
                                                        res.push(htlc_success_tx);
                                                }
                                        }
@@ -2013,7 +2169,7 @@ impl ChannelMonitor {
                                spendable_outputs.append(&mut $updates.1);
                                watch_outputs.append(&mut $updates.2);
                                for claim in $updates.3 {
-                                       match self.our_claim_txn_waiting_first_conf.entry(claim.0) {
+                                       match self.pending_claim_requests.entry(claim.0) {
                                                hash_map::Entry::Occupied(_) => {},
                                                hash_map::Entry::Vacant(entry) => { entry.insert(claim.1); }
                                        }
@@ -2193,24 +2349,36 @@ impl ChannelMonitor {
                        if updated.len() > 0 {
                                htlc_updated.append(&mut updated);
                        }
+
+                       // Scan all input to verify is one of the outpoint spent is of interest for us
                        for inp in &tx.input {
-                               if self.our_claim_txn_waiting_first_conf.contains_key(&inp.previous_output) {
-                                       match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
-                                               hash_map::Entry::Occupied(mut entry) => {
-                                                       let e = entry.get_mut();
-                                                       e.retain(|ref event| {
-                                                               match **event {
-                                                                       OnchainEvent::Claim { outpoint } => {
-                                                                               return outpoint != inp.previous_output
-                                                                       },
-                                                                       _ => return true
-                                                               }
-                                                       });
-                                                       e.push(OnchainEvent::Claim { outpoint: inp.previous_output.clone()});
+                               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) {
+                                               //... 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;
                                                }
-                                               hash_map::Entry::Vacant(entry) => {
-                                                       entry.insert(vec![OnchainEvent::Claim { outpoint: inp.previous_output.clone()}]);
+                                               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;
+                                                       }
+                                               }
+                                               if set_equality { // 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) => {
+                                                                       entry.insert(vec![OnchainEvent::Claim { claim_request: ancestor_claimable_txid.0.clone()}]);
+                                                               }
+                                                       }
+                                               } else { // If false, generate new claim request with update outpoint set
+                                                       //TODO: use bump engine
                                                }
+                                       } else {
+                                               panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
                                        }
                                }
                        }
@@ -2249,7 +2417,7 @@ impl ChannelMonitor {
                        }
                }
                for claim in pending_claims {
-                       match self.our_claim_txn_waiting_first_conf.entry(claim.0) {
+                       match self.pending_claim_requests.entry(claim.0) {
                                hash_map::Entry::Occupied(_) => {},
                                hash_map::Entry::Vacant(entry) => { entry.insert(claim.1); }
                        }
@@ -2257,8 +2425,9 @@ impl ChannelMonitor {
                if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
                        for ev in events {
                                match ev {
-                                       OnchainEvent::Claim { outpoint } => {
-                                               self.our_claim_txn_waiting_first_conf.remove(&outpoint);
+                                       OnchainEvent::Claim { claim_request } => {
+                                               // We may remove a whole set of claim outpoints here, as these one may have been aggregated in a single tx and claimed so atomically
+                                               self.pending_claim_requests.remove(&claim_request);
                                        },
                                        OnchainEvent::HTLCUpdate { htlc_update } => {
                                                log_trace!(self, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!((htlc_update.1).0));
@@ -2267,7 +2436,6 @@ impl ChannelMonitor {
                                }
                        }
                }
-               //TODO: iter on buffered TxMaterial in our_claim_txn_waiting_first_conf, if block timer is expired generate a bumped claim tx (RBF or CPFP accordingly)
                self.last_block_hash = block_hash.clone();
                (watch_outputs, spendable_outputs, htlc_updated)
        }
@@ -2278,7 +2446,7 @@ 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.3 == height { false } else { true });
+               self.claimable_outpoints.retain(|_, ref v| if v.1 == height { false } else { true });
                self.last_block_hash = block_hash.clone();
        }
 
@@ -2704,61 +2872,19 @@ impl<R: ::std::io::Read> ReadableArgs<R, Arc<Logger>> for (Sha256dHash, ChannelM
                        _ => return Err(DecodeError::InvalidValue),
                };
 
-               let our_claim_txn_waiting_first_conf_len: u64 = Readable::read(reader)?;
-               let mut our_claim_txn_waiting_first_conf = HashMap::with_capacity(cmp::min(our_claim_txn_waiting_first_conf_len as usize, MAX_ALLOC_SIZE / 128));
-               for _ in 0..our_claim_txn_waiting_first_conf_len {
+               let pending_claim_requests_len: u64 = Readable::read(reader)?;
+               let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
+               for _ in 0..pending_claim_requests_len {
+                       pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
+               }
+
+               let claimable_outpoints_len: u64 = Readable::read(reader)?;
+               let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
+               for _ in 0..claimable_outpoints_len {
                        let outpoint = Readable::read(reader)?;
-                       let height_target = Readable::read(reader)?;
-                       let tx_material = match <u8 as Readable<R>>::read(reader)? {
-                               0 => {
-                                       let script = Readable::read(reader)?;
-                                       let pubkey = Readable::read(reader)?;
-                                       let key = Readable::read(reader)?;
-                                       let is_htlc = match <u8 as Readable<R>>::read(reader)? {
-                                               0 => true,
-                                               1 => false,
-                                               _ => return Err(DecodeError::InvalidValue),
-                                       };
-                                       let amount = Readable::read(reader)?;
-                                       TxMaterial::Revoked {
-                                               script,
-                                               pubkey,
-                                               key,
-                                               is_htlc,
-                                               amount
-                                       }
-                               },
-                               1 => {
-                                       let script = Readable::read(reader)?;
-                                       let key = Readable::read(reader)?;
-                                       let preimage = Readable::read(reader)?;
-                                       let amount = Readable::read(reader)?;
-                                       TxMaterial::RemoteHTLC {
-                                               script,
-                                               key,
-                                               preimage,
-                                               amount
-                                       }
-                               },
-                               2 => {
-                                       let script = Readable::read(reader)?;
-                                       let their_sig = Readable::read(reader)?;
-                                       let our_sig = Readable::read(reader)?;
-                                       let preimage = Readable::read(reader)?;
-                                       let amount = Readable::read(reader)?;
-                                       TxMaterial::LocalHTLC {
-                                               script,
-                                               sigs: (their_sig, our_sig),
-                                               preimage,
-                                               amount
-                                       }
-                               }
-                               _ => return Err(DecodeError::InvalidValue),
-                       };
-                       let last_fee = Readable::read(reader)?;
-                       let timelock_expiration = Readable::read(reader)?;
+                       let ancestor_claim_txid = 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));
+                       claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
                }
 
                let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
@@ -2770,9 +2896,9 @@ impl<R: ::std::io::Read> ReadableArgs<R, Arc<Logger>> for (Sha256dHash, ChannelM
                        for _ in 0..events_len {
                                let ev = match <u8 as Readable<R>>::read(reader)? {
                                        0 => {
-                                               let outpoint = Readable::read(reader)?;
+                                               let claim_request = Readable::read(reader)?;
                                                OnchainEvent::Claim {
-                                                       outpoint
+                                                       claim_request
                                                }
                                        },
                                        1 => {
@@ -2814,7 +2940,9 @@ impl<R: ::std::io::Read> ReadableArgs<R, Arc<Logger>> for (Sha256dHash, ChannelM
                        destination_script,
                        to_remote_rescue,
 
-                       our_claim_txn_waiting_first_conf,
+                       pending_claim_requests,
+
+                       claimable_outpoints,
 
                        onchain_events_waiting_threshold_conf,