Merge pull request #1380 from TheBlueMatt/2022-03-skip-redundant-sig-checks

Skip `channel_update` signature checks if we have a newer state

diff --git a/lightning/src/routing/network_graph.rs b/lightning/src/routing/network_graph.rs
index 012357df361767e330a698f492846a6b44e8917b..13e6beedd4da247c777b37aea628550d9473ce63 100644 (file)
--- a/lightning/src/routing/network_graph.rs
+++ b/lightning/src/routing/network_graph.rs
@@ -1376,8 +1376,8 @@ impl NetworkGraph {
                                                }
                                        }
                                }
-                               macro_rules! maybe_update_channel_info {
-                                       ( $target: expr, $src_node: expr) => {
+                               macro_rules! check_update_latest {
+                                       ($target: expr) => {
                                                if let Some(existing_chan_info) = $target.as_ref() {
                                                        // The timestamp field is somewhat of a misnomer - the BOLTs use it to
                                                        // order updates to ensure you always have the latest one, only
@@ -1394,7 +1394,11 @@ impl NetworkGraph {
                                                } else {
                                                        chan_was_enabled = false;
                                                }
+                                       }
+                               }
 
+                               macro_rules! get_new_channel_info {
+                                       () => { {
                                                let last_update_message = if msg.excess_data.len() <= MAX_EXCESS_BYTES_FOR_RELAY
                                                        { full_msg.cloned() } else { None };
 
@@ -1410,29 +1414,31 @@ impl NetworkGraph {
                                                        },
                                                        last_update_message
                                                };
-                                               $target = Some(updated_channel_update_info);
-                                       }
+                                               Some(updated_channel_update_info)
+                                       } }
                                }
 
                                let msg_hash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
                                if msg.flags & 1 == 1 {
                                        dest_node_id = channel.node_one.clone();
+                                       check_update_latest!(channel.two_to_one);
                                        if let Some((sig, ctx)) = sig_info {
                                                secp_verify_sig!(ctx, &msg_hash, &sig, &PublicKey::from_slice(channel.node_two.as_slice()).map_err(|_| LightningError{
                                                        err: "Couldn't parse source node pubkey".to_owned(),
                                                        action: ErrorAction::IgnoreAndLog(Level::Debug)
                                                })?, "channel_update");
                                        }
-                                       maybe_update_channel_info!(channel.two_to_one, channel.node_two);
+                                       channel.two_to_one = get_new_channel_info!();
                                } else {
                                        dest_node_id = channel.node_two.clone();
+                                       check_update_latest!(channel.one_to_two);
                                        if let Some((sig, ctx)) = sig_info {
                                                secp_verify_sig!(ctx, &msg_hash, &sig, &PublicKey::from_slice(channel.node_one.as_slice()).map_err(|_| LightningError{
                                                        err: "Couldn't parse destination node pubkey".to_owned(),
                                                        action: ErrorAction::IgnoreAndLog(Level::Debug)
                                                })?, "channel_update");
                                        }
-                                       maybe_update_channel_info!(channel.one_to_two, channel.node_one);
+                                       channel.one_to_two = get_new_channel_info!();
                                }
                        }
                }