Store+expose bits of Channel[Monitor] to figure out local state

[rust-lightning] / src / ln / channelmonitor.rs

diff --git a/src/ln/channelmonitor.rs b/src/ln/channelmonitor.rs
index 09f052426c5b5f32b99038175ac9a8d3b599a03b..594045f464ace5373a7db284ae4cf1eef7ed99f9 100644 (file)
--- a/src/ln/channelmonitor.rs
+++ b/src/ln/channelmonitor.rs
@@ -278,6 +278,10 @@ pub struct ChannelMonitor {
        prev_local_signed_commitment_tx: Option<LocalSignedTx>,
        current_local_signed_commitment_tx: Option<LocalSignedTx>,
 
+       // Used just for ChannelManager to make sure it has the latest channel data during
+       // deserialization
+       current_remote_commitment_number: u64,
+
        payment_preimages: HashMap<[u8; 32], [u8; 32]>,
 
        destination_script: Script,
@@ -309,6 +313,7 @@ impl PartialEq for ChannelMonitor {
                        self.remote_commitment_txn_on_chain != other.remote_commitment_txn_on_chain ||
                        self.remote_hash_commitment_number != other.remote_hash_commitment_number ||
                        self.prev_local_signed_commitment_tx != other.prev_local_signed_commitment_tx ||
+                       self.current_remote_commitment_number != other.current_remote_commitment_number ||
                        self.current_local_signed_commitment_tx != other.current_local_signed_commitment_tx ||
                        self.payment_preimages != other.payment_preimages ||
                        self.destination_script != other.destination_script
@@ -352,6 +357,7 @@ impl ChannelMonitor {
 
                        prev_local_signed_commitment_tx: None,
                        current_local_signed_commitment_tx: None,
+                       current_remote_commitment_number: 1 << 48,
 
                        payment_preimages: HashMap::new(),
                        destination_script: destination_script,
@@ -471,6 +477,7 @@ impl ChannelMonitor {
                        self.remote_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
                }
                self.remote_claimable_outpoints.insert(unsigned_commitment_tx.txid(), htlc_outputs);
+               self.current_remote_commitment_number = commitment_number;
        }
 
        /// Informs this monitor of the latest local (ie broadcastable) commitment transaction. The
@@ -528,6 +535,8 @@ impl ChannelMonitor {
                if our_min_secret > other_min_secret {
                        self.provide_secret(other_min_secret, other.get_secret(other_min_secret).unwrap(), None)?;
                }
+               // TODO: We should use current_remote_commitment_number and the commitment number out of
+               // local transactions to decide how to merge
                if our_min_secret >= other_min_secret {
                        self.their_cur_revocation_points = other.their_cur_revocation_points;
                        for (txid, htlcs) in other.remote_claimable_outpoints.drain() {
@@ -541,6 +550,7 @@ impl ChannelMonitor {
                        }
                        self.payment_preimages = other.payment_preimages;
                }
+               self.current_remote_commitment_number = cmp::min(self.current_remote_commitment_number, other.current_remote_commitment_number);
                Ok(())
        }
 
@@ -748,6 +758,12 @@ impl ChannelMonitor {
                        writer.write_all(&[0; 1])?;
                }
 
+               if for_local_storage {
+                       writer.write_all(&byte_utils::be48_to_array(self.current_remote_commitment_number))?;
+               } else {
+                       writer.write_all(&byte_utils::be48_to_array(0))?;
+               }
+
                writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
                for payment_preimage in self.payment_preimages.values() {
                        writer.write_all(payment_preimage)?;
@@ -806,6 +822,16 @@ impl ChannelMonitor {
                min
        }
 
+       pub(super) fn get_cur_remote_commitment_number(&self) -> u64 {
+               self.current_remote_commitment_number
+       }
+
+       pub(super) fn get_cur_local_commitment_number(&self) -> u64 {
+               if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
+                       0xffff_ffff_ffff - ((((local_tx.tx.input[0].sequence as u64 & 0xffffff) << 3*8) | (local_tx.tx.lock_time as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor)
+               } else { 0xffff_ffff_ffff }
+       }
+
        /// Attempts to claim a remote commitment transaction's outputs using the revocation key and
        /// data in remote_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
        /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
@@ -1290,6 +1316,23 @@ impl ChannelMonitor {
                (Vec::new(), Vec::new())
        }
 
+       /// Used by ChannelManager deserialization to broadcast the latest local state if it's copy of
+       /// the Channel was out-of-date.
+       pub(super) fn get_latest_local_commitment_txn(&self) -> Vec<Transaction> {
+               if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
+                       let mut res = vec![local_tx.tx.clone()];
+                       match self.key_storage {
+                               KeyStorage::PrivMode { ref delayed_payment_base_key, ref prev_latest_per_commitment_point, .. } => {
+                                       res.append(&mut self.broadcast_by_local_state(local_tx, prev_latest_per_commitment_point, &Some(*delayed_payment_base_key)).0);
+                               },
+                               _ => panic!("Can only broadcast by local channelmonitor"),
+                       };
+                       res
+               } else {
+                       Vec::new()
+               }
+       }
+
        fn block_connected(&mut self, txn_matched: &[&Transaction], height: u32, block_hash: &Sha256dHash, broadcaster: &BroadcasterInterface)-> (Vec<(Sha256dHash, Vec<TxOut>)>, Vec<SpendableOutputDescriptor>) {
                let mut watch_outputs = Vec::new();
                let mut spendable_outputs = Vec::new();
@@ -1576,6 +1619,8 @@ impl<R: ::std::io::Read> ReadableArgs<R, Arc<Logger>> for (Sha256dHash, ChannelM
                        _ => return Err(DecodeError::InvalidValue),
                };
 
+               let current_remote_commitment_number = <U48 as Readable<R>>::read(reader)?.0;
+
                let payment_preimages_len: u64 = Readable::read(reader)?;
                let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
                let mut sha = Sha256::new();
@@ -1612,6 +1657,7 @@ impl<R: ::std::io::Read> ReadableArgs<R, Arc<Logger>> for (Sha256dHash, ChannelM
 
                        prev_local_signed_commitment_tx,
                        current_local_signed_commitment_tx,
+                       current_remote_commitment_number,
 
                        payment_preimages,