Fail HTLC backwards on unrevoked remote commitment tx broadcast
[rust-lightning] / src / ln / channelmonitor.rs
index 045ee36d28af6387794736659312cfc8f80a7c52..13cdfd2fe5d75433c5c28db097af4c12c0965de1 100644 (file)
@@ -17,11 +17,12 @@ use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
 use bitcoin::blockdata::script::{Script, Builder};
 use bitcoin::blockdata::opcodes;
 use bitcoin::consensus::encode::{self, Decodable, Encodable};
-use bitcoin::util::hash::{Hash160, BitcoinHash,Sha256dHash};
+use bitcoin::util::hash::{BitcoinHash,Sha256dHash};
 use bitcoin::util::bip143;
 
 use bitcoin_hashes::Hash;
 use bitcoin_hashes::sha256::Hash as Sha256;
+use bitcoin_hashes::hash160::Hash as Hash160;
 
 use secp256k1::{Secp256k1,Message,Signature};
 use secp256k1::key::{SecretKey,PublicKey};
@@ -567,6 +568,8 @@ impl ChannelMonitor {
                }
 
                let new_txid = unsigned_commitment_tx.txid();
+               log_trace!(self, "Tracking new remote commitment transaction with txid {} at commitment number {} with {} HTLC outputs", new_txid, commitment_number, htlc_outputs.len());
+               log_trace!(self, "New potential remote commitment transaction: {}", encode::serialize_hex(unsigned_commitment_tx));
                if let Storage::Local { ref mut current_remote_commitment_txid, ref mut prev_remote_commitment_txid, .. } = self.key_storage {
                        *prev_remote_commitment_txid = current_remote_commitment_txid.take();
                        *current_remote_commitment_txid = Some(new_txid);
@@ -986,9 +989,6 @@ impl ChannelMonitor {
                self.write(writer, false)
        }
 
-       //TODO: Functions to serialize/deserialize (with different forms depending on which information
-       //we want to leave out (eg funding_txo, etc).
-
        /// Can only fail if idx is < get_min_seen_secret
        pub(super) fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
                for i in 0..self.old_secrets.len() {
@@ -1077,7 +1077,7 @@ impl ChannelMonitor {
                        let local_payment_p2wpkh = if let Some(payment_key) = local_payment_key {
                                // Note that the Network here is ignored as we immediately drop the address for the
                                // script_pubkey version.
-                               let payment_hash160 = Hash160::from_data(&PublicKey::from_secret_key(&self.secp_ctx, &payment_key).serialize());
+                               let payment_hash160 = Hash160::hash(&PublicKey::from_secret_key(&self.secp_ctx, &payment_key).serialize());
                                Some(Builder::new().push_opcode(opcodes::All::OP_PUSHBYTES_0).push_slice(&payment_hash160[..]).into_script())
                        } else { None };
 
@@ -1245,6 +1245,44 @@ impl ChannelMonitor {
                        watch_outputs.append(&mut tx.output.clone());
                        self.remote_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
 
+                       log_trace!(self, "Got broadcast of non-revoked remote commitment transaction {}", commitment_txid);
+
+                       // TODO: We really should only fail backwards after our revocation claims have been
+                       // confirmed, but we also need to do more other tracking of in-flight pre-confirm
+                       // on-chain claims, so we can do that at the same time.
+                       macro_rules! check_htlc_fails {
+                               ($txid: expr, $commitment_tx: expr, $id: tt) => {
+                                       if let Some(&(_, ref latest_outpoints)) = self.remote_claimable_outpoints.get(&$txid) {
+                                               $id: for &(ref payment_hash, ref source, _) in latest_outpoints.iter() {
+                                                       // Check if the HTLC is present in the commitment transaction that was
+                                                       // broadcast, but not if it was below the dust limit, which we should
+                                                       // fail backwards immediately as there is no way for us to learn the
+                                                       // payment_preimage.
+                                                       // Note that if the dust limit were allowed to change between
+                                                       // commitment transactions we'd want to be check whether *any*
+                                                       // broadcastable commitment transaction has the HTLC in it, but it
+                                                       // cannot currently change after channel initialization, so we don't
+                                                       // need to here.
+                                                       for &(_, ref broadcast_source, ref output_idx) in per_commitment_data.1.iter() {
+                                                               if output_idx.is_some() && source == broadcast_source {
+                                                                       continue $id;
+                                                               }
+                                                       }
+                                                       log_trace!(self, "Failing HTLC with payment_hash {} from {} remote commitment tx due to broadcast of remote commitment transaction", log_bytes!(payment_hash.0), $commitment_tx);
+                                                       htlc_updated.push(((*source).clone(), None, payment_hash.clone()));
+                                               }
+                                       }
+                               }
+                       }
+                       if let Storage::Local { ref current_remote_commitment_txid, ref prev_remote_commitment_txid, .. } = self.key_storage {
+                               if let &Some(ref txid) = current_remote_commitment_txid {
+                                       check_htlc_fails!(txid, "current", 'current_loop);
+                               }
+                               if let &Some(ref txid) = prev_remote_commitment_txid {
+                                       check_htlc_fails!(txid, "previous", 'prev_loop);
+                               }
+                       }
+
                        if let Some(revocation_points) = self.their_cur_revocation_points {
                                let revocation_point_option =
                                        if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
@@ -1405,10 +1443,6 @@ impl ChannelMonitor {
                                                output: spend_tx.output[0].clone(),
                                        });
                                        txn_to_broadcast.push(spend_tx);
-
-                                       // TODO: We need to fail back HTLCs that were't included in the broadcast
-                                       // commitment transaction, either because they didn't meet dust or because a
-                                       // stale (but not yet revoked) commitment transaction was broadcast!
                                }
                        }
                }
@@ -1619,7 +1653,7 @@ impl ChannelMonitor {
                if tx.input[0].sequence == 0xFFFFFFFF && !tx.input[0].witness.is_empty() && tx.input[0].witness.last().unwrap().len() == 71 {
                        match self.key_storage {
                                Storage::Local { ref shutdown_pubkey, .. } =>  {
-                                       let our_channel_close_key_hash = Hash160::from_data(&shutdown_pubkey.serialize());
+                                       let our_channel_close_key_hash = Hash160::hash(&shutdown_pubkey.serialize());
                                        let shutdown_script = Builder::new().push_opcode(opcodes::All::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script();
                                        for (idx, output) in tx.output.iter().enumerate() {
                                                if shutdown_script == output.script_pubkey {