From: Matt Corallo Date: Tue, 11 Dec 2018 04:56:34 +0000 (-0500) Subject: Fail all pending HTLCs if the remote broadcasts a revoked tx X-Git-Tag: v0.0.12~256^2~11 X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=b9c609eb6a1f0a558d4e3a77d053ae9b0804cdce;p=rust-lightning Fail all pending HTLCs if the remote broadcasts a revoked tx --- diff --git a/src/ln/channelmonitor.rs b/src/ln/channelmonitor.rs index 59c50061f..5028f2d6b 100644 --- a/src/ln/channelmonitor.rs +++ b/src/ln/channelmonitor.rs @@ -306,6 +306,8 @@ enum Storage { prev_latest_per_commitment_point: Option, latest_per_commitment_point: Option, funding_info: Option<(OutPoint, Script)>, + current_remote_commitment_txid: Option, + prev_remote_commitment_txid: Option, }, Watchtower { revocation_base_key: PublicKey, @@ -434,6 +436,8 @@ impl ChannelMonitor { prev_latest_per_commitment_point: None, latest_per_commitment_point: None, funding_info: None, + current_remote_commitment_txid: None, + prev_remote_commitment_txid: None, }, their_htlc_base_key: None, their_delayed_payment_base_key: None, @@ -496,8 +500,20 @@ impl ChannelMonitor { return Err(MonitorUpdateError("Previous secret did not match new one")); } } + if self.get_min_seen_secret() <= idx { + return Ok(()); + } self.old_secrets[pos as usize] = (secret, idx); + // Prune HTLCs from the previous remote commitment tx so we don't generate failure/fulfill + // events for now-revoked/fulfilled HTLCs. + // TODO: We should probably consider whether we're really getting the next secret here. + if let Storage::Local { ref mut prev_remote_commitment_txid, .. } = self.key_storage { + if let Some(txid) = prev_remote_commitment_txid.take() { + self.remote_claimable_outpoints.get_mut(&txid).unwrap().1 = Vec::new(); + } + } + if !self.payment_preimages.is_empty() { let local_signed_commitment_tx = self.current_local_signed_commitment_tx.as_ref().expect("Channel needs at least an initial commitment tx !"); let prev_local_signed_commitment_tx = self.prev_local_signed_commitment_tx.as_ref(); @@ -545,12 +561,13 @@ impl ChannelMonitor { for ref htlc in &htlc_outputs { self.remote_hash_commitment_number.insert(htlc.payment_hash, commitment_number); } - // 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(); + + let new_txid = unsigned_commitment_tx.txid(); + 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); } - self.remote_claimable_outpoints.insert(unsigned_commitment_tx.txid(), (htlc_outputs, htlc_sources)); + self.remote_claimable_outpoints.insert(new_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 { @@ -753,7 +770,7 @@ impl ChannelMonitor { U48(self.commitment_transaction_number_obscure_factor).write(writer)?; match self.key_storage { - Storage::Local { ref revocation_base_key, ref htlc_base_key, ref delayed_payment_base_key, ref payment_base_key, ref shutdown_pubkey, ref prev_latest_per_commitment_point, ref latest_per_commitment_point, ref funding_info } => { + Storage::Local { ref revocation_base_key, ref htlc_base_key, ref delayed_payment_base_key, ref payment_base_key, ref shutdown_pubkey, ref prev_latest_per_commitment_point, ref latest_per_commitment_point, ref funding_info, current_remote_commitment_txid, prev_remote_commitment_txid } => { writer.write_all(&[0; 1])?; writer.write_all(&revocation_base_key[..])?; writer.write_all(&htlc_base_key[..])?; @@ -782,6 +799,18 @@ impl ChannelMonitor { debug_assert!(false, "Try to serialize a useless Local monitor !"); }, } + if let Some(ref txid) = current_remote_commitment_txid { + writer.write_all(&[1; 1])?; + writer.write_all(&txid[..])?; + } else { + writer.write_all(&[0; 1])?; + } + if let Some(ref txid) = prev_remote_commitment_txid { + writer.write_all(&[1; 1])?; + writer.write_all(&txid[..])?; + } else { + writer.write_all(&[0; 1])?; + } }, Storage::Watchtower { .. } => unimplemented!(), } @@ -1177,6 +1206,27 @@ impl ChannelMonitor { output: spend_tx.output[0].clone(), }); txn_to_broadcast.push(spend_tx); + + // 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. + 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 { + if let Some(&(_, ref latest_outpoints)) = self.remote_claimable_outpoints.get(&txid) { + for &(ref payment_hash, ref source, _) in latest_outpoints.iter() { + htlc_updated.push(((*source).clone(), None, *payment_hash)); + } + } + } + if let &Some(ref txid) = prev_remote_commitment_txid { + if let Some(&(_, ref prev_outpoint)) = self.remote_claimable_outpoints.get(&txid) { + for &(ref payment_hash, ref source, _) in prev_outpoint.iter() { + htlc_updated.push(((*source).clone(), None, *payment_hash)); + } + } + } + } + // No need to check local commitment txn, symmetric HTLCSource must be present as per-htlc data on remote commitment tx } else if let Some(per_commitment_data) = per_commitment_option { // While this isn't useful yet, there is a potential race where if a counterparty // revokes a state at the same time as the commitment transaction for that state is @@ -1823,6 +1873,16 @@ impl ReadableArgs> for (Sha256dHash, ChannelM index: Readable::read(reader)?, }; let funding_info = Some((outpoint, Readable::read(reader)?)); + let current_remote_commitment_txid = match >::read(reader)? { + 0 => None, + 1 => Some(Readable::read(reader)?), + _ => return Err(DecodeError::InvalidValue), + }; + let prev_remote_commitment_txid = match >::read(reader)? { + 0 => None, + 1 => Some(Readable::read(reader)?), + _ => return Err(DecodeError::InvalidValue), + }; Storage::Local { revocation_base_key, htlc_base_key, @@ -1832,6 +1892,8 @@ impl ReadableArgs> for (Sha256dHash, ChannelM prev_latest_per_commitment_point, latest_per_commitment_point, funding_info, + current_remote_commitment_txid, + prev_remote_commitment_txid, } }, _ => return Err(DecodeError::InvalidValue),