Track HTLCSource in ChannelMonitor
[rust-lightning] / src / ln / channelmonitor.rs
index 48e5c002c34543b56648014033a209fa7a61d31c..15be91c30e760548b1cccaae96a411d6d3d702d1 100644 (file)
@@ -29,6 +29,7 @@ use secp256k1;
 use ln::msgs::DecodeError;
 use ln::chan_utils;
 use ln::chan_utils::HTLCOutputInCommitment;
+use ln::channelmanager::HTLCSource;
 use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface};
 use chain::transaction::OutPoint;
 use chain::keysinterface::SpendableOutputDescriptor;
@@ -259,6 +260,7 @@ struct LocalSignedTx {
        delayed_payment_key: PublicKey,
        feerate_per_kw: u64,
        htlc_outputs: Vec<(HTLCOutputInCommitment, Signature, Signature)>,
+       htlc_sources: Vec<([u8; 32], HTLCSource, Option<u32>)>,
 }
 
 const SERIALIZATION_VERSION: u8 = 1;
@@ -283,7 +285,7 @@ pub struct ChannelMonitor {
        their_to_self_delay: Option<u16>,
 
        old_secrets: [([u8; 32], u64); 49],
-       remote_claimable_outpoints: HashMap<Sha256dHash, Vec<HTLCOutputInCommitment>>,
+       remote_claimable_outpoints: HashMap<Sha256dHash, (Vec<HTLCOutputInCommitment>, Vec<([u8; 32], HTLCSource, Option<u32>)>)>,
        /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
        /// Nor can we figure out their commitment numbers without the commitment transaction they are
        /// spending. Thus, in order to claim them via revocation key, we track all the remote
@@ -471,15 +473,20 @@ impl ChannelMonitor {
        /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
        /// possibly future revocation/preimage information) to claim outputs where possible.
        /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
-       pub(super) fn provide_latest_remote_commitment_tx_info(&mut self, unsigned_commitment_tx: &Transaction, htlc_outputs: Vec<HTLCOutputInCommitment>, commitment_number: u64, their_revocation_point: PublicKey) {
+       pub(super) fn provide_latest_remote_commitment_tx_info(&mut self, unsigned_commitment_tx: &Transaction, htlc_outputs: Vec<HTLCOutputInCommitment>, htlc_sources: Vec<([u8; 32], HTLCSource, Option<u32>)>, commitment_number: u64, their_revocation_point: PublicKey) {
                // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
                // so that a remote monitor doesn't learn anything unless there is a malicious close.
                // (only maybe, sadly we cant do the same for local info, as we need to be aware of
                // timeouts)
-               for htlc in &htlc_outputs {
+               for ref htlc in &htlc_outputs {
                        self.remote_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
                }
-               self.remote_claimable_outpoints.insert(unsigned_commitment_tx.txid(), htlc_outputs);
+               // We prune old claimable outpoints, useless to pass backward state when remote commitment
+               // tx get revoked, optimize for storage
+               for (_, htlc_data) in self.remote_claimable_outpoints.iter_mut() {
+                       htlc_data.1 = Vec::new();
+               }
+               self.remote_claimable_outpoints.insert(unsigned_commitment_tx.txid(), (htlc_outputs, htlc_sources));
                self.current_remote_commitment_number = commitment_number;
                //TODO: Merge this into the other per-remote-transaction output storage stuff
                match self.their_cur_revocation_points {
@@ -509,7 +516,7 @@ impl ChannelMonitor {
        /// Panics if set_their_to_self_delay has never been called.
        /// Also update Storage with latest local per_commitment_point to derive local_delayedkey in
        /// case of onchain HTLC tx
-       pub(super) fn provide_latest_local_commitment_tx_info(&mut self, signed_commitment_tx: Transaction, local_keys: chan_utils::TxCreationKeys, feerate_per_kw: u64, htlc_outputs: Vec<(HTLCOutputInCommitment, Signature, Signature)>) {
+       pub(super) fn provide_latest_local_commitment_tx_info(&mut self, signed_commitment_tx: Transaction, local_keys: chan_utils::TxCreationKeys, feerate_per_kw: u64, htlc_outputs: Vec<(HTLCOutputInCommitment, Signature, Signature)>, htlc_sources: Vec<([u8; 32], HTLCSource, Option<u32>)>) {
                assert!(self.their_to_self_delay.is_some());
                self.prev_local_signed_commitment_tx = self.current_local_signed_commitment_tx.take();
                self.current_local_signed_commitment_tx = Some(LocalSignedTx {
@@ -521,6 +528,7 @@ impl ChannelMonitor {
                        delayed_payment_key: local_keys.a_delayed_payment_key,
                        feerate_per_kw,
                        htlc_outputs,
+                       htlc_sources,
                });
 
                if let Storage::Local { ref mut latest_per_commitment_point, .. } = self.key_storage {
@@ -753,13 +761,31 @@ impl ChannelMonitor {
                        }
                }
 
+               macro_rules! serialize_htlc_source {
+                       ($htlc_source: expr) => {
+                               $htlc_source.0.write(writer)?;
+                               $htlc_source.1.write(writer)?;
+                               if let &Some(ref txo) = &$htlc_source.2 {
+                                       writer.write_all(&[1; 1])?;
+                                       txo.write(writer)?;
+                               } else {
+                                       writer.write_all(&[0; 1])?;
+                               }
+                       }
+               }
+
+
                writer.write_all(&byte_utils::be64_to_array(self.remote_claimable_outpoints.len() as u64))?;
-               for (ref txid, ref htlc_outputs) in self.remote_claimable_outpoints.iter() {
+               for (ref txid, &(ref htlc_infos, ref htlc_sources)) in self.remote_claimable_outpoints.iter() {
                        writer.write_all(&txid[..])?;
-                       writer.write_all(&byte_utils::be64_to_array(htlc_outputs.len() as u64))?;
-                       for htlc_output in htlc_outputs.iter() {
+                       writer.write_all(&byte_utils::be64_to_array(htlc_infos.len() as u64))?;
+                       for ref htlc_output in htlc_infos.iter() {
                                serialize_htlc_in_commitment!(htlc_output);
                        }
+                       writer.write_all(&byte_utils::be64_to_array(htlc_sources.len() as u64))?;
+                       for ref htlc_source in htlc_sources.iter() {
+                               serialize_htlc_source!(htlc_source);
+                       }
                }
 
                writer.write_all(&byte_utils::be64_to_array(self.remote_commitment_txn_on_chain.len() as u64))?;
@@ -803,6 +829,10 @@ impl ChannelMonitor {
                                        writer.write_all(&their_sig.serialize_compact(&self.secp_ctx))?;
                                        writer.write_all(&our_sig.serialize_compact(&self.secp_ctx))?;
                                }
+                               writer.write_all(&byte_utils::be64_to_array($local_tx.htlc_sources.len() as u64))?;
+                               for ref htlc_source in $local_tx.htlc_sources.iter() {
+                                       serialize_htlc_source!(htlc_source);
+                               }
                        }
                }
 
@@ -985,7 +1015,7 @@ impl ChannelMonitor {
                                                let (sig, redeemscript) = match self.key_storage {
                                                        Storage::Local { ref revocation_base_key, .. } => {
                                                                let redeemscript = if $htlc_idx.is_none() { revokeable_redeemscript.clone() } else {
-                                                                       let htlc = &per_commitment_option.unwrap()[$htlc_idx.unwrap()];
+                                                                       let htlc = &per_commitment_option.unwrap().0[$htlc_idx.unwrap()];
                                                                        chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey)
                                                                };
                                                                let sighash = ignore_error!(Message::from_slice(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]));
@@ -1008,10 +1038,10 @@ impl ChannelMonitor {
                                }
                        }
 
-                       if let Some(per_commitment_data) = per_commitment_option {
+                       if let Some(&(ref per_commitment_data, _)) = per_commitment_option {
                                inputs.reserve_exact(per_commitment_data.len());
 
-                               for (idx, htlc) in per_commitment_data.iter().enumerate() {
+                               for (idx, ref htlc) in per_commitment_data.iter().enumerate() {
                                        let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
                                        if htlc.transaction_output_index as usize >= tx.output.len() ||
                                                        tx.output[htlc.transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
@@ -1140,7 +1170,7 @@ impl ChannelMonitor {
                                                        {
                                                                let (sig, redeemscript) = match self.key_storage {
                                                                        Storage::Local { ref htlc_base_key, .. } => {
-                                                                               let htlc = &per_commitment_option.unwrap()[$input.sequence as usize];
+                                                                               let htlc = &per_commitment_option.unwrap().0[$input.sequence as usize];
                                                                                let redeemscript = chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
                                                                                let sighash = ignore_error!(Message::from_slice(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]));
                                                                                let htlc_key = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, revocation_point, &htlc_base_key));
@@ -1158,7 +1188,7 @@ impl ChannelMonitor {
                                                }
                                        }
 
-                                       for (idx, htlc) in per_commitment_data.iter().enumerate() {
+                                       for (idx, ref htlc) in per_commitment_data.0.iter().enumerate() {
                                                let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
                                                if htlc.transaction_output_index as usize >= tx.output.len() ||
                                                                tx.output[htlc.transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
@@ -1319,9 +1349,10 @@ impl ChannelMonitor {
                } else { (None, None) }
        }
 
-       fn broadcast_by_local_state(&self, local_tx: &LocalSignedTx, per_commitment_point: &Option<PublicKey>, delayed_payment_base_key: &Option<SecretKey>) -> (Vec<Transaction>, Vec<SpendableOutputDescriptor>) {
+       fn broadcast_by_local_state(&self, local_tx: &LocalSignedTx, per_commitment_point: &Option<PublicKey>, delayed_payment_base_key: &Option<SecretKey>) -> (Vec<Transaction>, Vec<SpendableOutputDescriptor>, Vec<TxOut>) {
                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());
 
                macro_rules! add_dynamic_output {
                        ($father_tx: expr, $vout: expr) => {
@@ -1385,24 +1416,27 @@ impl ChannelMonitor {
                                        res.push(htlc_success_tx);
                                }
                        }
+                       watch_outputs.push(local_tx.tx.output[htlc.transaction_output_index as usize].clone());
                }
 
-               (res, spendable_outputs)
+               (res, spendable_outputs, watch_outputs)
        }
 
        /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
        /// revoked using data in local_claimable_outpoints.
        /// Should not be used if check_spend_revoked_transaction succeeds.
-       fn check_spend_local_transaction(&self, tx: &Transaction, _height: u32) -> (Vec<Transaction>, Vec<SpendableOutputDescriptor>) {
+       fn check_spend_local_transaction(&self, tx: &Transaction, _height: u32) -> (Vec<Transaction>, Vec<SpendableOutputDescriptor>, (Sha256dHash, Vec<TxOut>)) {
                let commitment_txid = tx.txid();
                if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
                        if local_tx.txid == commitment_txid {
                                match self.key_storage {
                                        Storage::Local { ref delayed_payment_base_key, ref latest_per_commitment_point, .. } => {
-                                               return self.broadcast_by_local_state(local_tx, latest_per_commitment_point, &Some(*delayed_payment_base_key));
+                                               let (local_txn, spendable_outputs, watch_outputs) = self.broadcast_by_local_state(local_tx, latest_per_commitment_point, &Some(*delayed_payment_base_key));
+                                               return (local_txn, spendable_outputs, (commitment_txid, watch_outputs));
                                        },
                                        Storage::Watchtower { .. } => {
-                                               return self.broadcast_by_local_state(local_tx, &None, &None);
+                                               let (local_txn, spendable_outputs, watch_outputs) = self.broadcast_by_local_state(local_tx, &None, &None);
+                                               return (local_txn, spendable_outputs, (commitment_txid, watch_outputs));
                                        }
                                }
                        }
@@ -1411,15 +1445,17 @@ impl ChannelMonitor {
                        if local_tx.txid == commitment_txid {
                                match self.key_storage {
                                        Storage::Local { ref delayed_payment_base_key, ref prev_latest_per_commitment_point, .. } => {
-                                               return self.broadcast_by_local_state(local_tx, prev_latest_per_commitment_point, &Some(*delayed_payment_base_key));
+                                               let (local_txn, spendable_outputs, watch_outputs) = self.broadcast_by_local_state(local_tx, prev_latest_per_commitment_point, &Some(*delayed_payment_base_key));
+                                               return (local_txn, spendable_outputs, (commitment_txid, watch_outputs));
                                        },
                                        Storage::Watchtower { .. } => {
-                                               return self.broadcast_by_local_state(local_tx, &None, &None);
+                                               let (local_txn, spendable_outputs, watch_outputs) = self.broadcast_by_local_state(local_tx, &None, &None);
+                                               return (local_txn, spendable_outputs, (commitment_txid, watch_outputs));
                                        }
                                }
                        }
                }
-               (Vec::new(), Vec::new())
+               (Vec::new(), Vec::new(), (commitment_txid, Vec::new()))
        }
 
        /// Generate a spendable output event when closing_transaction get registered onchain.
@@ -1491,9 +1527,12 @@ impl ChannelMonitor {
                                                watch_outputs.push(new_outputs);
                                        }
                                        if txn.is_empty() {
-                                               let (remote_txn, mut outputs) = self.check_spend_local_transaction(tx, height);
-                                               spendable_outputs.append(&mut outputs);
-                                               txn = remote_txn;
+                                               let (local_txn, mut spendable_output, new_outputs) = self.check_spend_local_transaction(tx, height);
+                                               spendable_outputs.append(&mut spendable_output);
+                                               txn = local_txn;
+                                               if !new_outputs.1.is_empty() {
+                                                       watch_outputs.push(new_outputs);
+                                               }
                                        }
                                        if !funding_txo.is_none() && txn.is_empty() {
                                                if let Some(spendable_output) = self.check_spend_closing_transaction(tx) {
@@ -1521,15 +1560,21 @@ impl ChannelMonitor {
                                broadcaster.broadcast_transaction(&cur_local_tx.tx);
                                match self.key_storage {
                                        Storage::Local { ref delayed_payment_base_key, ref latest_per_commitment_point, .. } => {
-                                               let (txs, mut outputs) = self.broadcast_by_local_state(&cur_local_tx, latest_per_commitment_point, &Some(*delayed_payment_base_key));
-                                               spendable_outputs.append(&mut outputs);
+                                               let (txs, mut spendable_output, new_outputs) = self.broadcast_by_local_state(&cur_local_tx, latest_per_commitment_point, &Some(*delayed_payment_base_key));
+                                               spendable_outputs.append(&mut spendable_output);
+                                               if !new_outputs.is_empty() {
+                                                       watch_outputs.push((cur_local_tx.txid.clone(), new_outputs));
+                                               }
                                                for tx in txs {
                                                        broadcaster.broadcast_transaction(&tx);
                                                }
                                        },
                                        Storage::Watchtower { .. } => {
-                                               let (txs, mut outputs) = self.broadcast_by_local_state(&cur_local_tx, &None, &None);
-                                               spendable_outputs.append(&mut outputs);
+                                               let (txs, mut spendable_output, new_outputs) = self.broadcast_by_local_state(&cur_local_tx, &None, &None);
+                                               spendable_outputs.append(&mut spendable_output);
+                                               if !new_outputs.is_empty() {
+                                                       watch_outputs.push((cur_local_tx.txid.clone(), new_outputs));
+                                               }
                                                for tx in txs {
                                                        broadcaster.broadcast_transaction(&tx);
                                                }
@@ -1677,6 +1722,20 @@ impl<R: ::std::io::Read> ReadableArgs<R, Arc<Logger>> for (Sha256dHash, ChannelM
                        }
                }
 
+               macro_rules! read_htlc_source {
+                       () => {
+                               {
+                                       (Readable::read(reader)?, Readable::read(reader)?,
+                                               match <u8 as Readable<R>>::read(reader)? {
+                                                       0 => None,
+                                                       1 => Some(Readable::read(reader)?),
+                                                       _ => return Err(DecodeError::InvalidValue),
+                                               }
+                                       )
+                               }
+                       }
+               }
+
                let remote_claimable_outpoints_len: u64 = Readable::read(reader)?;
                let mut remote_claimable_outpoints = HashMap::with_capacity(cmp::min(remote_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
                for _ in 0..remote_claimable_outpoints_len {
@@ -1686,7 +1745,12 @@ impl<R: ::std::io::Read> ReadableArgs<R, Arc<Logger>> for (Sha256dHash, ChannelM
                        for _ in 0..outputs_count {
                                outputs.push(read_htlc_in_commitment!());
                        }
-                       if let Some(_) = remote_claimable_outpoints.insert(txid, outputs) {
+                       let sources_count: u64 = Readable::read(reader)?;
+                       let mut sources = Vec::with_capacity(cmp::min(sources_count as usize, MAX_ALLOC_SIZE / 32));
+                       for _ in 0..sources_count {
+                               sources.push(read_htlc_source!());
+                       }
+                       if let Some(_) = remote_claimable_outpoints.insert(txid, (outputs, sources)) {
                                return Err(DecodeError::InvalidValue);
                        }
                }
@@ -1741,12 +1805,20 @@ impl<R: ::std::io::Read> ReadableArgs<R, Arc<Logger>> for (Sha256dHash, ChannelM
                                        let htlc_outputs_len: u64 = Readable::read(reader)?;
                                        let mut htlc_outputs = Vec::with_capacity(cmp::min(htlc_outputs_len as usize, MAX_ALLOC_SIZE / 128));
                                        for _ in 0..htlc_outputs_len {
-                                               htlc_outputs.push((read_htlc_in_commitment!(), Readable::read(reader)?, Readable::read(reader)?));
+                                               let out = read_htlc_in_commitment!();
+                                               let sigs = (Readable::read(reader)?, Readable::read(reader)?);
+                                               htlc_outputs.push((out, sigs.0, sigs.1));
+                                       }
+
+                                       let htlc_sources_len: u64 = Readable::read(reader)?;
+                                       let mut htlc_sources = Vec::with_capacity(cmp::min(htlc_outputs_len as usize, MAX_ALLOC_SIZE / 128));
+                                       for _ in 0..htlc_sources_len {
+                                               htlc_sources.push(read_htlc_source!());
                                        }
 
                                        LocalSignedTx {
                                                txid: tx.txid(),
-                                               tx, revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, feerate_per_kw, htlc_outputs
+                                               tx, revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, feerate_per_kw, htlc_outputs, htlc_sources
                                        }
                                }
                        }
@@ -2265,11 +2337,11 @@ mod tests {
                let mut monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), &SecretKey::from_slice(&secp_ctx, &[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[45; 32]).unwrap()), 0, Script::new(), logger.clone());
                monitor.set_their_to_self_delay(10);
 
-               monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..10]));
-               monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key);
-               monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key);
-               monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key);
-               monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key);
+               monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..10]), Vec::new());
+               monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), Vec::new(), 281474976710655, dummy_key);
+               monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), Vec::new(), 281474976710654, dummy_key);
+               monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), Vec::new(), 281474976710653, dummy_key);
+               monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), Vec::new(), 281474976710652, dummy_key);
                for &(ref preimage, ref hash) in preimages.iter() {
                        monitor.provide_payment_preimage(hash, preimage);
                }
@@ -2291,7 +2363,7 @@ mod tests {
 
                // Now update local commitment tx info, pruning only element 18 as we still care about the
                // previous commitment tx's preimages too
-               monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..5]));
+               monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..5]), Vec::new());
                secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
                monitor.provide_secret(281474976710653, secret.clone()).unwrap();
                assert_eq!(monitor.payment_preimages.len(), 12);
@@ -2299,7 +2371,7 @@ mod tests {
                test_preimages_exist!(&preimages[18..20], monitor);
 
                // But if we do it again, we'll prune 5-10
-               monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..3]));
+               monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..3]), Vec::new());
                secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
                monitor.provide_secret(281474976710652, secret.clone()).unwrap();
                assert_eq!(monitor.payment_preimages.len(), 5);