Simplify and expand logging in is_resolving_htlc_output
[rust-lightning] / src / ln / channelmanager.rs
index 03d7e0866f1de10208b5ef04ac39f4d52f09f6f9..0b7def9ad87bf8b02a9ae22565d9854de2617144 100644 (file)
@@ -208,13 +208,16 @@ impl MsgHandleErrInternal {
 /// probably increase this significantly.
 const MIN_HTLC_RELAY_HOLDING_CELL_MILLIS: u32 = 50;
 
-pub(super) struct HTLCForwardInfo {
-       prev_short_channel_id: u64,
-       prev_htlc_id: u64,
-       #[cfg(test)]
-       pub(super) forward_info: PendingForwardHTLCInfo,
-       #[cfg(not(test))]
-       forward_info: PendingForwardHTLCInfo,
+pub(super) enum HTLCForwardInfo {
+       AddHTLC {
+               prev_short_channel_id: u64,
+               prev_htlc_id: u64,
+               forward_info: PendingForwardHTLCInfo,
+       },
+       FailHTLC {
+               htlc_id: u64,
+               err_packet: msgs::OnionErrorPacket,
+       },
 }
 
 /// For events which result in both a RevokeAndACK and a CommitmentUpdate, by default they should
@@ -1161,13 +1164,23 @@ impl ChannelManager {
                                                Some(chan_id) => chan_id.clone(),
                                                None => {
                                                        failed_forwards.reserve(pending_forwards.len());
-                                                       for HTLCForwardInfo { prev_short_channel_id, prev_htlc_id, forward_info } in pending_forwards.drain(..) {
-                                                               let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData {
-                                                                       short_channel_id: prev_short_channel_id,
-                                                                       htlc_id: prev_htlc_id,
-                                                                       incoming_packet_shared_secret: forward_info.incoming_shared_secret,
-                                                               });
-                                                               failed_forwards.push((htlc_source, forward_info.payment_hash, 0x4000 | 10, None));
+                                                       for forward_info in pending_forwards.drain(..) {
+                                                               match forward_info {
+                                                                       HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info } => {
+                                                                               let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData {
+                                                                                       short_channel_id: prev_short_channel_id,
+                                                                                       htlc_id: prev_htlc_id,
+                                                                                       incoming_packet_shared_secret: forward_info.incoming_shared_secret,
+                                                                               });
+                                                                               failed_forwards.push((htlc_source, forward_info.payment_hash, 0x4000 | 10, None));
+                                                                       },
+                                                                       HTLCForwardInfo::FailHTLC { .. } => {
+                                                                               // Channel went away before we could fail it. This implies
+                                                                               // the channel is now on chain and our counterparty is
+                                                                               // trying to broadcast the HTLC-Timeout, but that's their
+                                                                               // problem, not ours.
+                                                                       }
+                                                               }
                                                        }
                                                        continue;
                                                }
@@ -1175,36 +1188,74 @@ impl ChannelManager {
                                        let forward_chan = &mut channel_state.by_id.get_mut(&forward_chan_id).unwrap();
 
                                        let mut add_htlc_msgs = Vec::new();
-                                       for HTLCForwardInfo { prev_short_channel_id, prev_htlc_id, forward_info } in pending_forwards.drain(..) {
-                                               let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData {
-                                                       short_channel_id: prev_short_channel_id,
-                                                       htlc_id: prev_htlc_id,
-                                                       incoming_packet_shared_secret: forward_info.incoming_shared_secret,
-                                               });
-                                               match forward_chan.send_htlc(forward_info.amt_to_forward, forward_info.payment_hash, forward_info.outgoing_cltv_value, htlc_source.clone(), forward_info.onion_packet.unwrap()) {
-                                                       Err(_e) => {
-                                                               let chan_update = self.get_channel_update(forward_chan).unwrap();
-                                                               failed_forwards.push((htlc_source, forward_info.payment_hash, 0x1000 | 7, Some(chan_update)));
-                                                               continue;
+                                       let mut fail_htlc_msgs = Vec::new();
+                                       for forward_info in pending_forwards.drain(..) {
+                                               match forward_info {
+                                                       HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info } => {
+                                                               log_trace!(self, "Adding HTLC from short id {} with payment_hash {} to channel with short id {} after delay", log_bytes!(forward_info.payment_hash.0), prev_short_channel_id, short_chan_id);
+                                                               let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData {
+                                                                       short_channel_id: prev_short_channel_id,
+                                                                       htlc_id: prev_htlc_id,
+                                                                       incoming_packet_shared_secret: forward_info.incoming_shared_secret,
+                                                               });
+                                                               match forward_chan.send_htlc(forward_info.amt_to_forward, forward_info.payment_hash, forward_info.outgoing_cltv_value, htlc_source.clone(), forward_info.onion_packet.unwrap()) {
+                                                                       Err(e) => {
+                                                                               if let ChannelError::Ignore(msg) = e {
+                                                                                       log_trace!(self, "Failed to forward HTLC with payment_hash {}: {}", log_bytes!(forward_info.payment_hash.0), msg);
+                                                                               } else {
+                                                                                       panic!("Stated return value requirements in send_htlc() were not met");
+                                                                               }
+                                                                               let chan_update = self.get_channel_update(forward_chan).unwrap();
+                                                                               failed_forwards.push((htlc_source, forward_info.payment_hash, 0x1000 | 7, Some(chan_update)));
+                                                                               continue;
+                                                                       },
+                                                                       Ok(update_add) => {
+                                                                               match update_add {
+                                                                                       Some(msg) => { add_htlc_msgs.push(msg); },
+                                                                                       None => {
+                                                                                               // Nothing to do here...we're waiting on a remote
+                                                                                               // revoke_and_ack before we can add anymore HTLCs. The Channel
+                                                                                               // will automatically handle building the update_add_htlc and
+                                                                                               // commitment_signed messages when we can.
+                                                                                               // TODO: Do some kind of timer to set the channel as !is_live()
+                                                                                               // as we don't really want others relying on us relaying through
+                                                                                               // this channel currently :/.
+                                                                                       }
+                                                                               }
+                                                                       }
+                                                               }
                                                        },
-                                                       Ok(update_add) => {
-                                                               match update_add {
-                                                                       Some(msg) => { add_htlc_msgs.push(msg); },
-                                                                       None => {
+                                                       HTLCForwardInfo::FailHTLC { htlc_id, err_packet } => {
+                                                               log_trace!(self, "Failing HTLC back to channel with short id {} after delay", short_chan_id);
+                                                               match forward_chan.get_update_fail_htlc(htlc_id, err_packet) {
+                                                                       Err(e) => {
+                                                                               if let ChannelError::Ignore(msg) = e {
+                                                                                       log_trace!(self, "Failed to fail backwards to short_id {}: {}", short_chan_id, msg);
+                                                                               } else {
+                                                                                       panic!("Stated return value requirements in get_update_fail_htlc() were not met");
+                                                                               }
+                                                                               // fail-backs are best-effort, we probably already have one
+                                                                               // pending, and if not that's OK, if not, the channel is on
+                                                                               // the chain and sending the HTLC-Timeout is their problem.
+                                                                               continue;
+                                                                       },
+                                                                       Ok(Some(msg)) => { fail_htlc_msgs.push(msg); },
+                                                                       Ok(None) => {
                                                                                // Nothing to do here...we're waiting on a remote
-                                                                               // revoke_and_ack before we can add anymore HTLCs. The Channel
-                                                                               // will automatically handle building the update_add_htlc and
-                                                                               // commitment_signed messages when we can.
-                                                                               // TODO: Do some kind of timer to set the channel as !is_live()
-                                                                               // as we don't really want others relying on us relaying through
-                                                                               // this channel currently :/.
+                                                                               // revoke_and_ack before we can update the commitment
+                                                                               // transaction. The Channel will automatically handle
+                                                                               // building the update_fail_htlc and commitment_signed
+                                                                               // messages when we can.
+                                                                               // We don't need any kind of timer here as they should fail
+                                                                               // the channel onto the chain if they can't get our
+                                                                               // update_fail_htlc in time, its not our problem.
                                                                        }
                                                                }
-                                                       }
+                                                       },
                                                }
                                        }
 
-                                       if !add_htlc_msgs.is_empty() {
+                                       if !add_htlc_msgs.is_empty() || !fail_htlc_msgs.is_empty() {
                                                let (commitment_msg, monitor) = match forward_chan.send_commitment() {
                                                        Ok(res) => res,
                                                        Err(e) => {
@@ -1223,7 +1274,7 @@ impl ChannelManager {
                                                        updates: msgs::CommitmentUpdate {
                                                                update_add_htlcs: add_htlc_msgs,
                                                                update_fulfill_htlcs: Vec::new(),
-                                                               update_fail_htlcs: Vec::new(),
+                                                               update_fail_htlcs: fail_htlc_msgs,
                                                                update_fail_malformed_htlcs: Vec::new(),
                                                                update_fee: None,
                                                                commitment_signed: commitment_msg,
@@ -1231,20 +1282,27 @@ impl ChannelManager {
                                                });
                                        }
                                } else {
-                                       for HTLCForwardInfo { prev_short_channel_id, prev_htlc_id, forward_info } in pending_forwards.drain(..) {
-                                               let prev_hop_data = HTLCPreviousHopData {
-                                                       short_channel_id: prev_short_channel_id,
-                                                       htlc_id: prev_htlc_id,
-                                                       incoming_packet_shared_secret: forward_info.incoming_shared_secret,
-                                               };
-                                               match channel_state.claimable_htlcs.entry(forward_info.payment_hash) {
-                                                       hash_map::Entry::Occupied(mut entry) => entry.get_mut().push(prev_hop_data),
-                                                       hash_map::Entry::Vacant(entry) => { entry.insert(vec![prev_hop_data]); },
-                                               };
-                                               new_events.push(events::Event::PaymentReceived {
-                                                       payment_hash: forward_info.payment_hash,
-                                                       amt: forward_info.amt_to_forward,
-                                               });
+                                       for forward_info in pending_forwards.drain(..) {
+                                               match forward_info {
+                                                       HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info } => {
+                                                               let prev_hop_data = HTLCPreviousHopData {
+                                                                       short_channel_id: prev_short_channel_id,
+                                                                       htlc_id: prev_htlc_id,
+                                                                       incoming_packet_shared_secret: forward_info.incoming_shared_secret,
+                                                               };
+                                                               match channel_state.claimable_htlcs.entry(forward_info.payment_hash) {
+                                                                       hash_map::Entry::Occupied(mut entry) => entry.get_mut().push(prev_hop_data),
+                                                                       hash_map::Entry::Vacant(entry) => { entry.insert(vec![prev_hop_data]); },
+                                                               };
+                                                               new_events.push(events::Event::PaymentReceived {
+                                                                       payment_hash: forward_info.payment_hash,
+                                                                       amt: forward_info.amt_to_forward,
+                                                               });
+                                                       },
+                                                       HTLCForwardInfo::FailHTLC { .. } => {
+                                                               panic!("Got pending fail of our own HTLC");
+                                                       }
+                                               }
                                        }
                                }
                        }
@@ -1289,6 +1347,10 @@ impl ChannelManager {
        /// drop it). In other words, no assumptions are made that entries in claimable_htlcs point to
        /// still-available channels.
        fn fail_htlc_backwards_internal(&self, mut channel_state_lock: MutexGuard<ChannelHolder>, source: HTLCSource, payment_hash: &PaymentHash, onion_error: HTLCFailReason) {
+               //TODO: There is a timing attack here where if a node fails an HTLC back to us they can
+               //identify whether we sent it or not based on the (I presume) very different runtime
+               //between the branches here. We should make this async and move it into the forward HTLCs
+               //timer handling.
                match source {
                        HTLCSource::OutboundRoute { ref route, .. } => {
                                log_trace!(self, "Failing outbound payment HTLC with payment_hash {}", log_bytes!(payment_hash.0));
@@ -1353,36 +1415,25 @@ impl ChannelManager {
                                        }
                                };
 
-                               let channel_state = channel_state_lock.borrow_parts();
-
-                               let chan_id = match channel_state.short_to_id.get(&short_channel_id) {
-                                       Some(chan_id) => chan_id.clone(),
-                                       None => return
-                               };
-
-                               let chan = channel_state.by_id.get_mut(&chan_id).unwrap();
-                               match chan.get_update_fail_htlc_and_commit(htlc_id, err_packet) {
-                                       Ok(Some((msg, commitment_msg, chan_monitor))) => {
-                                               if let Err(_e) = self.monitor.add_update_monitor(chan_monitor.get_funding_txo().unwrap(), chan_monitor) {
-                                                       unimplemented!();
-                                               }
-                                               channel_state.pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs {
-                                                       node_id: chan.get_their_node_id(),
-                                                       updates: msgs::CommitmentUpdate {
-                                                               update_add_htlcs: Vec::new(),
-                                                               update_fulfill_htlcs: Vec::new(),
-                                                               update_fail_htlcs: vec![msg],
-                                                               update_fail_malformed_htlcs: Vec::new(),
-                                                               update_fee: None,
-                                                               commitment_signed: commitment_msg,
-                                                       },
-                                               });
-                                       },
-                                       Ok(None) => {},
-                                       Err(_e) => {
-                                               //TODO: Do something with e?
-                                               return;
+                               let mut forward_event = None;
+                               if channel_state_lock.forward_htlcs.is_empty() {
+                                       forward_event = Some(Instant::now() + Duration::from_millis(((rng::rand_f32() * 4.0 + 1.0) * MIN_HTLC_RELAY_HOLDING_CELL_MILLIS as f32) as u64));
+                                       channel_state_lock.next_forward = forward_event.unwrap();
+                               }
+                               match channel_state_lock.forward_htlcs.entry(short_channel_id) {
+                                       hash_map::Entry::Occupied(mut entry) => {
+                                               entry.get_mut().push(HTLCForwardInfo::FailHTLC { htlc_id, err_packet });
                                        },
+                                       hash_map::Entry::Vacant(entry) => {
+                                               entry.insert(vec!(HTLCForwardInfo::FailHTLC { htlc_id, err_packet }));
+                                       }
+                               }
+                               mem::drop(channel_state_lock);
+                               if let Some(time) = forward_event {
+                                       let mut pending_events = self.pending_events.lock().unwrap();
+                                       pending_events.push(events::Event::PendingHTLCsForwardable {
+                                               time_forwardable: time
+                                       });
                                }
                        },
                }
@@ -1956,10 +2007,10 @@ impl ChannelManager {
                                for (forward_info, prev_htlc_id) in pending_forwards.drain(..) {
                                        match channel_state.forward_htlcs.entry(forward_info.short_channel_id) {
                                                hash_map::Entry::Occupied(mut entry) => {
-                                                       entry.get_mut().push(HTLCForwardInfo { prev_short_channel_id, prev_htlc_id, forward_info });
+                                                       entry.get_mut().push(HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info });
                                                },
                                                hash_map::Entry::Vacant(entry) => {
-                                                       entry.insert(vec!(HTLCForwardInfo { prev_short_channel_id, prev_htlc_id, forward_info }));
+                                                       entry.insert(vec!(HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info }));
                                                }
                                        }
                                }
@@ -2714,11 +2765,41 @@ impl<R: ::std::io::Read> Readable<R> for HTLCFailReason {
        }
 }
 
-impl_writeable!(HTLCForwardInfo, 0, {
-       prev_short_channel_id,
-       prev_htlc_id,
-       forward_info
-});
+impl Writeable for HTLCForwardInfo {
+       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
+               match self {
+                       &HTLCForwardInfo::AddHTLC { ref prev_short_channel_id, ref prev_htlc_id, ref forward_info } => {
+                               0u8.write(writer)?;
+                               prev_short_channel_id.write(writer)?;
+                               prev_htlc_id.write(writer)?;
+                               forward_info.write(writer)?;
+                       },
+                       &HTLCForwardInfo::FailHTLC { ref htlc_id, ref err_packet } => {
+                               1u8.write(writer)?;
+                               htlc_id.write(writer)?;
+                               err_packet.write(writer)?;
+                       },
+               }
+               Ok(())
+       }
+}
+
+impl<R: ::std::io::Read> Readable<R> for HTLCForwardInfo {
+       fn read(reader: &mut R) -> Result<HTLCForwardInfo, DecodeError> {
+               match <u8 as Readable<R>>::read(reader)? {
+                       0 => Ok(HTLCForwardInfo::AddHTLC {
+                               prev_short_channel_id: Readable::read(reader)?,
+                               prev_htlc_id: Readable::read(reader)?,
+                               forward_info: Readable::read(reader)?,
+                       }),
+                       1 => Ok(HTLCForwardInfo::FailHTLC {
+                               htlc_id: Readable::read(reader)?,
+                               err_packet: Readable::read(reader)?,
+                       }),
+                       _ => Err(DecodeError::InvalidValue),
+               }
+       }
+}
 
 impl Writeable for ChannelManager {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {