Ignore our own gossip if it is sent to us from our counterparty

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

diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index 88f35e6667c4c4396f41929124ae89c9344d84a8..47ea356442398d461e68f4656b81e0d35ffe1b79 100644 (file)
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -3408,7 +3408,13 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                        }
                                        return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a channel_update for a channel from the wrong node - it shouldn't know about our private channels!".to_owned(), chan_id));
                                }
-                               try_chan_entry!(self, chan.get_mut().channel_update(&msg), channel_state, chan);
+                               let were_node_one = self.get_our_node_id().serialize()[..] < chan.get().get_counterparty_node_id().serialize()[..];
+                               let msg_from_node_one = msg.contents.flags & 1 == 0;
+                               if were_node_one == msg_from_node_one {
+                                       return Ok(NotifyOption::SkipPersist);
+                               } else {
+                                       try_chan_entry!(self, chan.get_mut().channel_update(&msg), channel_state, chan);
+                               }
                        },
                        hash_map::Entry::Vacant(_) => unreachable!()
                }
@@ -4984,6 +4990,31 @@ mod tests {
                // At this point the channel info given by peers should still be the same.
                assert_eq!(nodes[0].node.list_channels()[0], node_a_chan_info);
                assert_eq!(nodes[1].node.list_channels()[0], node_b_chan_info);
+
+               // An earlier version of handle_channel_update didn't check the directionality of the
+               // update message and would always update the local fee info, even if our peer was
+               // (spuriously) forwarding us our own channel_update.
+               let as_node_one = nodes[0].node.get_our_node_id().serialize()[..] < nodes[1].node.get_our_node_id().serialize()[..];
+               let as_update = if as_node_one == (chan.0.contents.flags & 1 == 0 /* chan.0 is from node one */) { &chan.0 } else { &chan.1 };
+               let bs_update = if as_node_one == (chan.0.contents.flags & 1 == 0 /* chan.0 is from node one */) { &chan.1 } else { &chan.0 };
+
+               // First deliver each peers' own message, checking that the node doesn't need to be
+               // persisted and that its channel info remains the same.
+               nodes[0].node.handle_channel_update(&nodes[1].node.get_our_node_id(), &as_update);
+               nodes[1].node.handle_channel_update(&nodes[0].node.get_our_node_id(), &bs_update);
+               assert!(!nodes[0].node.await_persistable_update_timeout(Duration::from_millis(1)));
+               assert!(!nodes[1].node.await_persistable_update_timeout(Duration::from_millis(1)));
+               assert_eq!(nodes[0].node.list_channels()[0], node_a_chan_info);
+               assert_eq!(nodes[1].node.list_channels()[0], node_b_chan_info);
+
+               // Finally, deliver the other peers' message, ensuring each node needs to be persisted and
+               // the channel info has updated.
+               nodes[0].node.handle_channel_update(&nodes[1].node.get_our_node_id(), &bs_update);
+               nodes[1].node.handle_channel_update(&nodes[0].node.get_our_node_id(), &as_update);
+               assert!(nodes[0].node.await_persistable_update_timeout(Duration::from_millis(1)));
+               assert!(nodes[1].node.await_persistable_update_timeout(Duration::from_millis(1)));
+               assert_ne!(nodes[0].node.list_channels()[0], node_a_chan_info);
+               assert_ne!(nodes[1].node.list_channels()[0], node_b_chan_info);
        }
 }