Support reading `channel_update`s in onions with message type bytes

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

diff --git a/lightning/src/ln/onion_utils.rs b/lightning/src/ln/onion_utils.rs
index 0dd6087f82018d9faf56d53672325b76284caa00..5b9d1787055124b51eb43b3d5d98652078f97f0c 100644 (file)
--- a/lightning/src/ln/onion_utils.rs
+++ b/lightning/src/ln/onion_utils.rs
@@ -404,7 +404,15 @@ pub(super) fn process_onion_failure<T: secp256k1::Signing, L: Deref>(secp_ctx: &
                                                else if error_code & UPDATE == UPDATE {
                                                        if let Some(update_len_slice) = err_packet.failuremsg.get(debug_field_size+2..debug_field_size+4) {
                                                                let update_len = u16::from_be_bytes(update_len_slice.try_into().expect("len is 2")) as usize;
-                                                               if let Some(update_slice) = err_packet.failuremsg.get(debug_field_size + 4..debug_field_size + 4 + update_len) {
+                                                               if let Some(mut update_slice) = err_packet.failuremsg.get(debug_field_size + 4..debug_field_size + 4 + update_len) {
+                                                                       // Historically, the BOLTs were unclear if the message type
+                                                                       // bytes should be included here or not. The BOLTs have now
+                                                                       // been updated to indicate that they *are* included, but many
+                                                                       // nodes still send messages without the type bytes, so we
+                                                                       // support both here.
+                                                                       if update_slice.len() > 2 && update_slice[0..2] == [0x01, 0x02] {
+                                                                               update_slice = &update_slice[2..];
+                                                                       }
                                                                        if let Ok(chan_update) = msgs::ChannelUpdate::read(&mut Cursor::new(&update_slice)) {
                                                                                // if channel_update should NOT have caused the failure:
                                                                                // MAY treat the channel_update as invalid.
@@ -434,6 +442,8 @@ pub(super) fn process_onion_failure<T: secp256k1::Signing, L: Deref>(secp_ctx: &
                                                                                        // short channel id.
                                                                                        if failing_route_hop.short_channel_id == chan_update.contents.short_channel_id {
                                                                                                short_channel_id = Some(failing_route_hop.short_channel_id);
+                                                                                       } else {
+                                                                                               log_info!(logger, "Node provided a channel_update for which it was not authoritative, ignoring.");
                                                                                        }
                                                                                        network_update = Some(NetworkUpdate::ChannelUpdateMessage {
                                                                                                msg: chan_update,
@@ -478,10 +488,10 @@ pub(super) fn process_onion_failure<T: secp256k1::Signing, L: Deref>(secp_ctx: &
 
                                                let (description, title) = errors::get_onion_error_description(error_code);
                                                if debug_field_size > 0 && err_packet.failuremsg.len() >= 4 + debug_field_size {
-                                                       log_warn!(logger, "Onion Error[from {}: {}({:#x}) {}({})] {}", route_hop.pubkey, title, error_code, debug_field, log_bytes!(&err_packet.failuremsg[4..4+debug_field_size]), description);
+                                                       log_info!(logger, "Onion Error[from {}: {}({:#x}) {}({})] {}", route_hop.pubkey, title, error_code, debug_field, log_bytes!(&err_packet.failuremsg[4..4+debug_field_size]), description);
                                                }
                                                else {
-                                                       log_warn!(logger, "Onion Error[from {}: {}({:#x})] {}", route_hop.pubkey, title, error_code, description);
+                                                       log_info!(logger, "Onion Error[from {}: {}({:#x})] {}", route_hop.pubkey, title, error_code, description);
                                                }
                                        } else {
                                                // Useless packet that we can't use but it passed HMAC, so it