- let reason = if let Ok(upd) = self.get_channel_update_for_unicast(chan) {
- onion_utils::build_first_hop_failure_packet(incoming_shared_secret, error_code, &{
- let mut res = Vec::with_capacity(8 + 128);
- // TODO: underspecified, follow https://github.com/lightningnetwork/lightning-rfc/issues/791
- res.extend_from_slice(&byte_utils::be16_to_array(0));
- res.extend_from_slice(&upd.encode_with_len()[..]);
- res
- }[..])
+ let reason = if (error_code & 0x1000) != 0 {
+ if let Ok(upd) = self.get_channel_update_for_unicast(chan) {
+ onion_utils::build_first_hop_failure_packet(incoming_shared_secret, error_code, &{
+ let mut res = Vec::with_capacity(8 + 128);
+ // TODO: underspecified, follow https://github.com/lightningnetwork/lightning-rfc/issues/791
+ res.extend_from_slice(&byte_utils::be16_to_array(0));
+ res.extend_from_slice(&upd.encode_with_len()[..]);
+ res
+ }[..])
+ } else {
+ // The only case where we'd be unable to
+ // successfully get a channel update is if the
+ // channel isn't in the fully-funded state yet,
+ // implying our counterparty is trying to route
+ // payments over the channel back to themselves
+ // (because no one else should know the short_id
+ // is a lightning channel yet). We should have
+ // no problem just calling this
+ // unknown_next_peer (0x4000|10).
+ onion_utils::build_first_hop_failure_packet(incoming_shared_secret, 0x4000|10, &[])
+ }