Send channel_update messages to direct peers on private channels
authorMatt Corallo <git@bluematt.me>
Sat, 12 Jun 2021 21:58:50 +0000 (21:58 +0000)
committerMatt Corallo <git@bluematt.me>
Wed, 7 Jul 2021 19:45:33 +0000 (19:45 +0000)
If we are a public node and have a private channel, our
counterparty needs to know the fees which we will charge to forward
payments to them. Without sending them a channel_update, they have
no way to learn that information, resulting in the channel being
effectively useless for outbound-from-us payments.

This commit fixes our lack of channel_update messages to private
channel counterparties, ensuring we always send them a
channel_update after the channel funding is confirmed.

fuzz/src/chanmon_consistency.rs
lightning-background-processor/src/lib.rs
lightning/src/ln/chanmon_update_fail_tests.rs
lightning/src/ln/channelmanager.rs
lightning/src/ln/functional_test_utils.rs
lightning/src/ln/functional_tests.rs
lightning/src/ln/peer_handler.rs
lightning/src/util/events.rs

index 085e4cb7402b4545fff6415ae871459977d6e3f5..158d87149a5ef2eff4b45d83cb953057fc48c74b 100644 (file)
@@ -571,7 +571,12 @@ pub fn do_test<Out: test_logger::Output>(data: &[u8], out: Out) {
                                                events::MessageSendEvent::SendFundingLocked { .. } => continue,
                                                events::MessageSendEvent::SendAnnouncementSignatures { .. } => continue,
                                                events::MessageSendEvent::PaymentFailureNetworkUpdate { .. } => continue,
-                                               _ => panic!("Unhandled message event"),
+                                               events::MessageSendEvent::SendChannelUpdate { ref node_id, ref msg } => {
+                                                       assert_eq!(msg.contents.flags & 2, 0); // The disable bit must never be set!
+                                                       if Some(*node_id) == expect_drop_id { panic!("peer_disconnected should drop msgs bound for the disconnected peer"); }
+                                                       *node_id == a_id
+                                               },
+                                               _ => panic!("Unhandled message event {:?}", event),
                                        };
                                        if push_a { ba_events.push(event); } else { bc_events.push(event); }
                                }
@@ -692,7 +697,16 @@ pub fn do_test<Out: test_logger::Output>(data: &[u8], out: Out) {
                                                        // Can be generated due to a payment forward being rejected due to a
                                                        // channel having previously failed a monitor update
                                                },
-                                               _ => panic!("Unhandled message event"),
+                                               events::MessageSendEvent::SendChannelUpdate { ref msg, .. } => {
+                                                       // When we reconnect we will resend a channel_update to make sure our
+                                                       // counterparty has the latest parameters for receiving payments
+                                                       // through us. We do, however, check that the message does not include
+                                                       // the "disabled" bit, as we should never ever have a channel which is
+                                                       // disabled when we send such an update (or it may indicate channel
+                                                       // force-close which we should detect as an error).
+                                                       assert_eq!(msg.contents.flags & 2, 0);
+                                               },
+                                               _ => panic!("Unhandled message event {:?}", event),
                                        }
                                        if $limit_events != ProcessMessages::AllMessages {
                                                break;
@@ -722,6 +736,9 @@ pub fn do_test<Out: test_logger::Output>(data: &[u8], out: Out) {
                                                        events::MessageSendEvent::SendFundingLocked { .. } => {},
                                                        events::MessageSendEvent::SendAnnouncementSignatures { .. } => {},
                                                        events::MessageSendEvent::PaymentFailureNetworkUpdate { .. } => {},
+                                                       events::MessageSendEvent::SendChannelUpdate { ref msg, .. } => {
+                                                               assert_eq!(msg.contents.flags & 2, 0); // The disable bit must never be set!
+                                                       },
                                                        _ => panic!("Unhandled message event"),
                                                }
                                        }
@@ -737,6 +754,9 @@ pub fn do_test<Out: test_logger::Output>(data: &[u8], out: Out) {
                                                        events::MessageSendEvent::SendFundingLocked { .. } => {},
                                                        events::MessageSendEvent::SendAnnouncementSignatures { .. } => {},
                                                        events::MessageSendEvent::PaymentFailureNetworkUpdate { .. } => {},
+                                                       events::MessageSendEvent::SendChannelUpdate { ref msg, .. } => {
+                                                               assert_eq!(msg.contents.flags & 2, 0); // The disable bit must never be set!
+                                                       },
                                                        _ => panic!("Unhandled message event"),
                                                }
                                        }
index dd13a35b46f6055807add340b88c41f41dcb7d6d..8c90532d1ea1491db56d8f90db3f0fedbf9bc01f 100644 (file)
@@ -443,9 +443,13 @@ mod tests {
 
                // Confirm the funding transaction.
                confirm_transaction(&mut nodes[0], &funding_tx);
+               let as_funding = get_event_msg!(nodes[0], MessageSendEvent::SendFundingLocked, nodes[1].node.get_our_node_id());
                confirm_transaction(&mut nodes[1], &funding_tx);
-               nodes[0].node.handle_funding_locked(&nodes[1].node.get_our_node_id(), &get_event_msg!(nodes[1], MessageSendEvent::SendFundingLocked, nodes[0].node.get_our_node_id()));
-               nodes[1].node.handle_funding_locked(&nodes[0].node.get_our_node_id(), &get_event_msg!(nodes[0], MessageSendEvent::SendFundingLocked, nodes[1].node.get_our_node_id()));
+               let bs_funding = get_event_msg!(nodes[1], MessageSendEvent::SendFundingLocked, nodes[0].node.get_our_node_id());
+               nodes[0].node.handle_funding_locked(&nodes[1].node.get_our_node_id(), &bs_funding);
+               let _as_channel_update = get_event_msg!(nodes[0], MessageSendEvent::SendChannelUpdate, nodes[1].node.get_our_node_id());
+               nodes[1].node.handle_funding_locked(&nodes[0].node.get_our_node_id(), &as_funding);
+               let _bs_channel_update = get_event_msg!(nodes[1], MessageSendEvent::SendChannelUpdate, nodes[0].node.get_our_node_id());
 
                assert!(bg_processor.stop().is_ok());
 
index dd7b1906ca079aced33d3a62384fc1772d02b49c..5f90b030dfb12ac78a0a089b9acf0a40e43f6166 100644 (file)
@@ -1158,7 +1158,10 @@ fn test_monitor_update_fail_reestablish() {
        nodes[0].node.handle_channel_reestablish(&nodes[1].node.get_our_node_id(), &bs_reestablish);
 
        nodes[1].node.handle_channel_reestablish(&nodes[0].node.get_our_node_id(), &as_reestablish);
-       assert!(nodes[1].node.get_and_clear_pending_msg_events().is_empty());
+       assert_eq!(
+               get_event_msg!(nodes[0], MessageSendEvent::SendChannelUpdate, nodes[1].node.get_our_node_id())
+                       .contents.flags & 2, 0); // The "disabled" bit should be unset as we just reconnected
+
        nodes[1].logger.assert_log("lightning::ln::channelmanager".to_string(), "Failed to update ChannelMonitor".to_string(), 1);
        check_added_monitors!(nodes[1], 1);
 
@@ -1172,10 +1175,15 @@ fn test_monitor_update_fail_reestablish() {
        assert!(bs_reestablish == get_event_msg!(nodes[1], MessageSendEvent::SendChannelReestablish, nodes[0].node.get_our_node_id()));
 
        nodes[0].node.handle_channel_reestablish(&nodes[1].node.get_our_node_id(), &bs_reestablish);
+       assert_eq!(
+               get_event_msg!(nodes[0], MessageSendEvent::SendChannelUpdate, nodes[1].node.get_our_node_id())
+                       .contents.flags & 2, 0); // The "disabled" bit should be unset as we just reconnected
 
        nodes[1].node.handle_channel_reestablish(&nodes[0].node.get_our_node_id(), &as_reestablish);
        check_added_monitors!(nodes[1], 0);
-       assert!(nodes[1].node.get_and_clear_pending_msg_events().is_empty());
+       assert_eq!(
+               get_event_msg!(nodes[1], MessageSendEvent::SendChannelUpdate, nodes[0].node.get_our_node_id())
+                       .contents.flags & 2, 0); // The "disabled" bit should be unset as we just reconnected
 
        *nodes[1].chain_monitor.update_ret.lock().unwrap() = Some(Ok(()));
        let (outpoint, latest_update) = nodes[1].chain_monitor.latest_monitor_update_id.lock().unwrap().get(&chan_1.2).unwrap().clone();
@@ -1352,14 +1360,14 @@ fn claim_while_disconnected_monitor_update_fail() {
        let bs_reconnect = get_event_msg!(nodes[1], MessageSendEvent::SendChannelReestablish, nodes[0].node.get_our_node_id());
 
        nodes[0].node.handle_channel_reestablish(&nodes[1].node.get_our_node_id(), &bs_reconnect);
-       assert!(nodes[0].node.get_and_clear_pending_msg_events().is_empty());
+       let _as_channel_update = get_event_msg!(nodes[0], MessageSendEvent::SendChannelUpdate, nodes[1].node.get_our_node_id());
 
        // Now deliver a's reestablish, freeing the claim from the holding cell, but fail the monitor
        // update.
        *nodes[1].chain_monitor.update_ret.lock().unwrap() = Some(Err(ChannelMonitorUpdateErr::TemporaryFailure));
 
        nodes[1].node.handle_channel_reestablish(&nodes[0].node.get_our_node_id(), &as_reconnect);
-       assert!(nodes[1].node.get_and_clear_pending_msg_events().is_empty());
+       let _bs_channel_update = get_event_msg!(nodes[1], MessageSendEvent::SendChannelUpdate, nodes[0].node.get_our_node_id());
        nodes[1].logger.assert_log("lightning::ln::channelmanager".to_string(), "Failed to update ChannelMonitor".to_string(), 1);
        check_added_monitors!(nodes[1], 1);
        assert!(nodes[1].node.get_and_clear_pending_msg_events().is_empty());
@@ -1492,7 +1500,9 @@ fn monitor_failed_no_reestablish_response() {
        let bs_reconnect = get_event_msg!(nodes[1], MessageSendEvent::SendChannelReestablish, nodes[0].node.get_our_node_id());
 
        nodes[1].node.handle_channel_reestablish(&nodes[0].node.get_our_node_id(), &as_reconnect);
+       let _bs_channel_update = get_event_msg!(nodes[1], MessageSendEvent::SendChannelUpdate, nodes[0].node.get_our_node_id());
        nodes[0].node.handle_channel_reestablish(&nodes[1].node.get_our_node_id(), &bs_reconnect);
+       let _as_channel_update = get_event_msg!(nodes[0], MessageSendEvent::SendChannelUpdate, nodes[1].node.get_our_node_id());
 
        *nodes[1].chain_monitor.update_ret.lock().unwrap() = Some(Ok(()));
        let (outpoint, latest_update) = nodes[1].chain_monitor.latest_monitor_update_id.lock().unwrap().get(&channel_id).unwrap().clone();
index 5caffe8ee12c01cea64532656ffa84339767fd59..8dbc17bae84309b81462571cae49caf6b4d24ed3 100644 (file)
@@ -1598,6 +1598,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                action: msgs::ErrorAction::IgnoreError
                        });
                }
+               log_trace!(self.logger, "Attempting to generate broadcast channel update for channel {}", log_bytes!(chan.channel_id()));
                self.get_channel_update_for_unicast(chan)
        }
 
@@ -1607,6 +1608,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
        /// provided evidence that they know about the existence of the channel.
        /// May be called with channel_state already locked!
        fn get_channel_update_for_unicast(&self, chan: &Channel<Signer>) -> Result<msgs::ChannelUpdate, LightningError> {
+               log_trace!(self.logger, "Attempting to generate channel update for channel {}", log_bytes!(chan.channel_id()));
                let short_channel_id = match chan.get_short_channel_id() {
                        None => return Err(LightningError{err: "Channel not yet established".to_owned(), action: msgs::ErrorAction::IgnoreError}),
                        Some(id) => id,
@@ -2789,7 +2791,8 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
        pub fn channel_monitor_updated(&self, funding_txo: &OutPoint, highest_applied_update_id: u64) {
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
 
-               let (mut pending_failures, chan_restoration_res) = {
+               let chan_restoration_res;
+               let mut pending_failures = {
                        let mut channel_lock = self.channel_state.lock().unwrap();
                        let channel_state = &mut *channel_lock;
                        let mut channel = match channel_state.by_id.entry(funding_txo.to_channel_id()) {
@@ -2801,7 +2804,21 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                        }
 
                        let (raa, commitment_update, order, pending_forwards, pending_failures, funding_broadcastable, funding_locked) = channel.get_mut().monitor_updating_restored(&self.logger);
-                       (pending_failures, handle_chan_restoration_locked!(self, channel_lock, channel_state, channel, raa, commitment_update, order, None, pending_forwards, funding_broadcastable, funding_locked))
+                       let channel_update = if funding_locked.is_some() && channel.get().is_usable() && !channel.get().should_announce() {
+                               // We only send a channel_update in the case where we are just now sending a
+                               // funding_locked and the channel is in a usable state. Further, we rely on the
+                               // normal announcement_signatures process to send a channel_update for public
+                               // channels, only generating a unicast channel_update if this is a private channel.
+                               Some(events::MessageSendEvent::SendChannelUpdate {
+                                       node_id: channel.get().get_counterparty_node_id(),
+                                       msg: self.get_channel_update_for_unicast(channel.get()).unwrap(),
+                               })
+                       } else { None };
+                       chan_restoration_res = handle_chan_restoration_locked!(self, channel_lock, channel_state, channel, raa, commitment_update, order, None, pending_forwards, funding_broadcastable, funding_locked);
+                       if let Some(upd) = channel_update {
+                               channel_state.pending_msg_events.push(upd);
+                       }
+                       pending_failures
                };
                post_handle_chan_restoration!(self, chan_restoration_res);
                for failure in pending_failures.drain(..) {
@@ -2964,6 +2981,11 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                node_id: counterparty_node_id.clone(),
                                                msg: announcement_sigs,
                                        });
+                               } else if chan.get().is_usable() {
+                                       channel_state.pending_msg_events.push(events::MessageSendEvent::SendChannelUpdate {
+                                               node_id: counterparty_node_id.clone(),
+                                               msg: self.get_channel_update_for_unicast(chan.get()).unwrap(),
+                                       });
                                }
                                Ok(())
                        },
@@ -3394,7 +3416,8 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
        }
 
        fn internal_channel_reestablish(&self, counterparty_node_id: &PublicKey, msg: &msgs::ChannelReestablish) -> Result<(), MsgHandleErrInternal> {
-               let (htlcs_failed_forward, need_lnd_workaround, chan_restoration_res) = {
+               let chan_restoration_res;
+               let (htlcs_failed_forward, need_lnd_workaround) = {
                        let mut channel_state_lock = self.channel_state.lock().unwrap();
                        let channel_state = &mut *channel_state_lock;
 
@@ -3409,15 +3432,27 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                        // add-HTLCs on disconnect, we may be handed HTLCs to fail backwards here.
                                        let (funding_locked, revoke_and_ack, commitment_update, monitor_update_opt, order, htlcs_failed_forward, shutdown) =
                                                try_chan_entry!(self, chan.get_mut().channel_reestablish(msg, &self.logger), channel_state, chan);
+                                       let mut channel_update = None;
                                        if let Some(msg) = shutdown {
                                                channel_state.pending_msg_events.push(events::MessageSendEvent::SendShutdown {
                                                        node_id: counterparty_node_id.clone(),
                                                        msg,
                                                });
+                                       } else if chan.get().is_usable() {
+                                               // If the channel is in a usable state (ie the channel is not being shut
+                                               // down), send a unicast channel_update to our counterparty to make sure
+                                               // they have the latest channel parameters.
+                                               channel_update = Some(events::MessageSendEvent::SendChannelUpdate {
+                                                       node_id: chan.get().get_counterparty_node_id(),
+                                                       msg: self.get_channel_update_for_unicast(chan.get()).unwrap(),
+                                               });
                                        }
                                        let need_lnd_workaround = chan.get_mut().workaround_lnd_bug_4006.take();
-                                       (htlcs_failed_forward, need_lnd_workaround,
-                                               handle_chan_restoration_locked!(self, channel_state_lock, channel_state, chan, revoke_and_ack, commitment_update, order, monitor_update_opt, Vec::new(), None, funding_locked))
+                                       chan_restoration_res = handle_chan_restoration_locked!(self, channel_state_lock, channel_state, chan, revoke_and_ack, commitment_update, order, monitor_update_opt, Vec::new(), None, funding_locked);
+                                       if let Some(upd) = channel_update {
+                                               channel_state.pending_msg_events.push(upd);
+                                       }
+                                       (htlcs_failed_forward, need_lnd_workaround)
                                },
                                hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.channel_id))
                        }
@@ -3970,6 +4005,12 @@ where
                                                                node_id: channel.get_counterparty_node_id(),
                                                                msg: announcement_sigs,
                                                        });
+                                               } else if channel.is_usable() {
+                                                       log_trace!(self.logger, "Sending funding_locked WITHOUT announcement_signatures but with private channel_update for our counterparty on channel {}", log_bytes!(channel.channel_id()));
+                                                       pending_msg_events.push(events::MessageSendEvent::SendChannelUpdate {
+                                                               node_id: channel.get_counterparty_node_id(),
+                                                               msg: self.get_channel_update_for_unicast(channel).unwrap(),
+                                                       });
                                                } else {
                                                        log_trace!(self.logger, "Sending funding_locked WITHOUT announcement_signatures for {}", log_bytes!(channel.channel_id()));
                                                }
@@ -4209,6 +4250,7 @@ impl<Signer: Sign, M: Deref , T: Deref , K: Deref , F: Deref , L: Deref >
                                        &events::MessageSendEvent::BroadcastChannelAnnouncement { .. } => true,
                                        &events::MessageSendEvent::BroadcastNodeAnnouncement { .. } => true,
                                        &events::MessageSendEvent::BroadcastChannelUpdate { .. } => true,
+                                       &events::MessageSendEvent::SendChannelUpdate { ref node_id, .. } => node_id != counterparty_node_id,
                                        &events::MessageSendEvent::HandleError { ref node_id, .. } => node_id != counterparty_node_id,
                                        &events::MessageSendEvent::PaymentFailureNetworkUpdate { .. } => true,
                                        &events::MessageSendEvent::SendChannelRangeQuery { .. } => false,
@@ -5042,7 +5084,19 @@ pub mod bench {
                Listen::block_connected(&node_b, &block, 1);
 
                node_a.handle_funding_locked(&node_b.get_our_node_id(), &get_event_msg!(node_b_holder, MessageSendEvent::SendFundingLocked, node_a.get_our_node_id()));
-               node_b.handle_funding_locked(&node_a.get_our_node_id(), &get_event_msg!(node_a_holder, MessageSendEvent::SendFundingLocked, node_b.get_our_node_id()));
+               let msg_events = node_a.get_and_clear_pending_msg_events();
+               assert_eq!(msg_events.len(), 2);
+               match msg_events[0] {
+                       MessageSendEvent::SendFundingLocked { ref msg, .. } => {
+                               node_b.handle_funding_locked(&node_a.get_our_node_id(), msg);
+                               get_event_msg!(node_b_holder, MessageSendEvent::SendChannelUpdate, node_a.get_our_node_id());
+                       },
+                       _ => panic!(),
+               }
+               match msg_events[1] {
+                       MessageSendEvent::SendChannelUpdate { .. } => {},
+                       _ => panic!(),
+               }
 
                let dummy_graph = NetworkGraph::new(genesis_hash);
 
index 00bde294cefa7eda24590a03596615a680872a14..e9fae460dd6e9605345c68d3134a0be0e7ab8b55 100644 (file)
@@ -1583,18 +1583,20 @@ macro_rules! handle_chan_reestablish_msgs {
                        let mut revoke_and_ack = None;
                        let mut commitment_update = None;
                        let order = if let Some(ev) = msg_events.get(idx) {
-                               idx += 1;
                                match ev {
                                        &MessageSendEvent::SendRevokeAndACK { ref node_id, ref msg } => {
                                                assert_eq!(*node_id, $dst_node.node.get_our_node_id());
                                                revoke_and_ack = Some(msg.clone());
+                                               idx += 1;
                                                RAACommitmentOrder::RevokeAndACKFirst
                                        },
                                        &MessageSendEvent::UpdateHTLCs { ref node_id, ref updates } => {
                                                assert_eq!(*node_id, $dst_node.node.get_our_node_id());
                                                commitment_update = Some(updates.clone());
+                                               idx += 1;
                                                RAACommitmentOrder::CommitmentFirst
                                        },
+                                       &MessageSendEvent::SendChannelUpdate { .. } => RAACommitmentOrder::CommitmentFirst,
                                        _ => panic!("Unexpected event"),
                                }
                        } else {
@@ -1607,16 +1609,24 @@ macro_rules! handle_chan_reestablish_msgs {
                                                assert_eq!(*node_id, $dst_node.node.get_our_node_id());
                                                assert!(revoke_and_ack.is_none());
                                                revoke_and_ack = Some(msg.clone());
+                                               idx += 1;
                                        },
                                        &MessageSendEvent::UpdateHTLCs { ref node_id, ref updates } => {
                                                assert_eq!(*node_id, $dst_node.node.get_our_node_id());
                                                assert!(commitment_update.is_none());
                                                commitment_update = Some(updates.clone());
+                                               idx += 1;
                                        },
+                                       &MessageSendEvent::SendChannelUpdate { .. } => {},
                                        _ => panic!("Unexpected event"),
                                }
                        }
 
+                       if let Some(&MessageSendEvent::SendChannelUpdate { ref node_id, ref msg }) = msg_events.get(idx) {
+                               assert_eq!(*node_id, $dst_node.node.get_our_node_id());
+                               assert_eq!(msg.contents.flags & 2, 0); // "disabled" flag must not be set as we just reconnected.
+                       }
+
                        (funding_locked, revoke_and_ack, commitment_update, order)
                }
        }
index df3c64ae8ff67ac0e429d720bfe304ba628341db..d6c4716b19d737b12283678f6c345e0b5dc01de9 100644 (file)
@@ -1039,7 +1039,8 @@ fn do_test_shutdown_rebroadcast(recv_count: u8) {
                nodes[0].node.handle_shutdown(&nodes[1].node.get_our_node_id(), &InitFeatures::known(), &node_1_2nd_shutdown);
                node_0_2nd_shutdown
        } else {
-               assert!(nodes[0].node.get_and_clear_pending_msg_events().is_empty());
+               let node_0_chan_update = get_event_msg!(nodes[0], MessageSendEvent::SendChannelUpdate, nodes[1].node.get_our_node_id());
+               assert_eq!(node_0_chan_update.contents.flags & 2, 0); // "disabled" flag must not be set as we just reconnected.
                nodes[0].node.handle_shutdown(&nodes[1].node.get_our_node_id(), &InitFeatures::known(), &node_1_2nd_shutdown);
                get_event_msg!(nodes[0], MessageSendEvent::SendShutdown, nodes[1].node.get_our_node_id())
        };
index 9e395f1107b1d62bfc26da2560b78e389987938c..96ec31c98ee1b4aa289f2ba78ee32c76a4e5f22d 100644 (file)
@@ -1264,6 +1264,12 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
                                                        self.forward_broadcast_msg(peers, &wire::Message::ChannelUpdate(msg), None);
                                                }
                                        },
+                                       MessageSendEvent::SendChannelUpdate { ref node_id, ref msg } => {
+                                               log_trace!(self.logger, "Handling SendChannelUpdate event in peer_handler for node {} for channel {}",
+                                                               log_pubkey!(node_id), msg.contents.short_channel_id);
+                                               let peer = get_peer_for_forwarding!(node_id);
+                                               peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
+                                       },
                                        MessageSendEvent::PaymentFailureNetworkUpdate { ref update } => {
                                                self.message_handler.route_handler.handle_htlc_fail_channel_update(update);
                                        },
index dbb4178fb50e4643db6e2332d0e257bab18f8e29..0fc7c6b3a3d166096019407784b929588ddbddd8 100644 (file)
@@ -389,6 +389,15 @@ pub enum MessageSendEvent {
                /// The channel_update which should be sent.
                msg: msgs::ChannelUpdate,
        },
+       /// Used to indicate that a channel_update should be sent to a single peer.
+       /// In contrast to [`Self::BroadcastChannelUpdate`], this is used when the channel is a
+       /// private channel and we shouldn't be informing all of our peers of channel parameters.
+       SendChannelUpdate {
+               /// The node_id of the node which should receive this message
+               node_id: PublicKey,
+               /// The channel_update which should be sent.
+               msg: msgs::ChannelUpdate,
+       },
        /// Broadcast an error downstream to be handled
        HandleError {
                /// The node_id of the node which should receive this message