Handle Error messages by closing channels as required by BOLT 1

src/ln/channelmanager.rs

@@ -2053,6 +2053,18 @@ impl ChannelMessageHandler for ChannelManager {
 			}
 		}
 	}
+
+	fn handle_error(&self, their_node_id: &PublicKey, msg: &msgs::ErrorMessage) {
+		if msg.channel_id == [0; 32] {
+			for chan in self.list_channels() {
+				if chan.remote_network_id == *their_node_id {
+					self.force_close_channel(&chan.channel_id);
+				}
+			}
+		} else {
+			self.force_close_channel(&msg.channel_id);
+		}
+	}
 }
 
 #[cfg(test)]

src/ln/msgs.rs

@@ -439,12 +439,14 @@ pub trait ChannelMessageHandler : events::EventsProvider + Send + Sync {
 	// Channel-to-announce:
 	fn handle_announcement_signatures(&self, their_node_id: &PublicKey, msg: &AnnouncementSignatures) -> Result<(), HandleError>;
 
-	// Informational:
+	// Error conditions:
 	/// Indicates a connection to the peer failed/an existing connection was lost. If no connection
 	/// is believed to be possible in the future (eg they're sending us messages we don't
 	/// understand or indicate they require unknown feature bits), no_connection_possible is set
 	/// and any outstanding channels should be failed.
 	fn peer_disconnected(&self, their_node_id: &PublicKey, no_connection_possible: bool);
+
+	fn handle_error(&self, their_node_id: &PublicKey, msg: &ErrorMessage);
 }
 
 pub trait RoutingMessageHandler : Send + Sync {

src/ln/peer_handler.rs

@@ -431,7 +431,24 @@ impl<Descriptor: SocketDescriptor> PeerManager<Descriptor> {
 												}
 											},
 											17 => {
-												// Error msg
+												let msg = try_potential_decodeerror!(msgs::ErrorMessage::decode(&msg_data[2..]));
+												let mut data_is_printable = true;
+												for b in msg.data.bytes() {
+													if b < 32 || b > 126 {
+														data_is_printable = false;
+														break;
+													}
+												}
+
+												if data_is_printable {
+													log_debug!(self, "Got Err message from {}: {}", log_pubkey!(peer.their_node_id.unwrap()), msg.data);
+												} else {
+													log_debug!(self, "Got Err message from {} with non-ASCII error message", log_pubkey!(peer.their_node_id.unwrap()));
+												}
+												self.message_handler.chan_handler.handle_error(&peer.their_node_id.unwrap(), &msg);
+												if msg.channel_id == [0; 32] {
+													return Err(PeerHandleError{ no_connection_possible: true });
+												}
 											},
 
 											18 => {

src/util/test_utils.rs

@@ -115,6 +115,7 @@ impl msgs::ChannelMessageHandler for TestChannelMessageHandler {
 		Err(HandleError { err: "", action: None })
 	}
 	fn peer_disconnected(&self, _their_node_id: &PublicKey, _no_connection_possible: bool) {}
+	fn handle_error(&self, _their_node_id: &PublicKey, _msg: &msgs::ErrorMessage) {}
 }
 
 impl events::EventsProvider for TestChannelMessageHandler {