Fix blinded recipient fail on malformed HTLC

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

diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index 662b85bcca52a4a683932d54c32c48f3f299199d..bf02015faf5f137f7db51364224c8a63e0602d6f 100644 (file)
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -4387,8 +4387,19 @@ where
                                                                                continue;
                                                                        }
                                                                },
-                                                               HTLCForwardInfo::FailMalformedHTLC { .. } => {
-                                                                       todo!()
+                                                               HTLCForwardInfo::FailMalformedHTLC { htlc_id, failure_code, sha256_of_onion } => {
+                                                                       log_trace!(self.logger, "Failing malformed HTLC back to channel with short id {} (backward HTLC ID {}) after delay", short_chan_id, htlc_id);
+                                                                       if let Err(e) = chan.queue_fail_malformed_htlc(htlc_id, failure_code, sha256_of_onion, &self.logger) {
+                                                                               if let ChannelError::Ignore(msg) = e {
+                                                                                       log_trace!(self.logger, "Failed to fail HTLC with ID {} backwards to short_id {}: {}", htlc_id, short_chan_id, msg);
+                                                                               } else {
+                                                                                       panic!("Stated return value requirements in queue_fail_malformed_htlc() were not met");
+                                                                               }
+                                                                               // fail-backs are best-effort, we probably already have one
+                                                                               // pending, and if not that's OK, if not, the channel is on
+                                                                               // the chain and sending the HTLC-Timeout is their problem.
+                                                                               continue;
+                                                                       }
                                                                },
                                                        }
                                                }
@@ -5249,16 +5260,26 @@ where
                                        "Failing {}HTLC with payment_hash {} backwards from us: {:?}",
                                        if blinded_failure.is_some() { "blinded " } else { "" }, &payment_hash, onion_error
                                );
-                               let err_packet = match blinded_failure {
+                               let failure = match blinded_failure {
                                        Some(BlindedFailure::FromIntroductionNode) => {
                                                let blinded_onion_error = HTLCFailReason::reason(INVALID_ONION_BLINDING, vec![0; 32]);
-                                               blinded_onion_error.get_encrypted_failure_packet(
+                                               let err_packet = blinded_onion_error.get_encrypted_failure_packet(
                                                        incoming_packet_shared_secret, phantom_shared_secret
-                                               )
+                                               );
+                                               HTLCForwardInfo::FailHTLC { htlc_id: *htlc_id, err_packet }
+                                       },
+                                       Some(BlindedFailure::FromBlindedNode) => {
+                                               HTLCForwardInfo::FailMalformedHTLC {
+                                                       htlc_id: *htlc_id,
+                                                       failure_code: INVALID_ONION_BLINDING,
+                                                       sha256_of_onion: [0; 32]
+                                               }
                                        },
-                                       Some(BlindedFailure::FromBlindedNode) => todo!(),
                                        None => {
-                                               onion_error.get_encrypted_failure_packet(incoming_packet_shared_secret, phantom_shared_secret)
+                                               let err_packet = onion_error.get_encrypted_failure_packet(
+                                                       incoming_packet_shared_secret, phantom_shared_secret
+                                               );
+                                               HTLCForwardInfo::FailHTLC { htlc_id: *htlc_id, err_packet }
                                        }
                                };
 
@@ -5269,10 +5290,10 @@ where
                                }
                                match forward_htlcs.entry(*short_channel_id) {
                                        hash_map::Entry::Occupied(mut entry) => {
-                                               entry.get_mut().push(HTLCForwardInfo::FailHTLC { htlc_id: *htlc_id, err_packet });
+                                               entry.get_mut().push(failure);
                                        },
                                        hash_map::Entry::Vacant(entry) => {
-                                               entry.insert(vec!(HTLCForwardInfo::FailHTLC { htlc_id: *htlc_id, err_packet }));
+                                               entry.insert(vec!(failure));
                                        }
                                }
                                mem::drop(forward_htlcs);