+#[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug
+pub(super) enum HTLCFailReason {
+ LightningError {
+ err: msgs::OnionErrorPacket,
+ },
+ Reason {
+ failure_code: u16,
+ data: Vec<u8>,
+ }
+}
+
+impl core::fmt::Debug for HTLCFailReason {
+ fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
+ match self {
+ HTLCFailReason::Reason { ref failure_code, .. } => {
+ write!(f, "HTLC error code {}", failure_code)
+ },
+ HTLCFailReason::LightningError { .. } => {
+ write!(f, "pre-built LightningError")
+ }
+ }
+ }
+}
+
+impl_writeable_tlv_based_enum!(HTLCFailReason,
+ (0, LightningError) => {
+ (0, err, required),
+ },
+ (1, Reason) => {
+ (0, failure_code, required),
+ (2, data, vec_type),
+ },
+;);
+
+impl HTLCFailReason {
+ pub(super) fn reason(failure_code: u16, data: Vec<u8>) -> Self {
+ Self::Reason { failure_code, data }
+ }
+
+ pub(super) fn from_failure_code(failure_code: u16) -> Self {
+ Self::Reason { failure_code, data: Vec::new() }
+ }
+
+ pub(super) fn from_msg(msg: &msgs::UpdateFailHTLC) -> Self {
+ Self::LightningError { err: msg.reason.clone() }
+ }
+
+ pub(super) fn get_encrypted_failure_packet(&self, incoming_packet_shared_secret: &[u8; 32], phantom_shared_secret: &Option<[u8; 32]>)
+ -> msgs::OnionErrorPacket {
+ match self {
+ HTLCFailReason::Reason { ref failure_code, ref data } => {
+ if let Some(phantom_ss) = phantom_shared_secret {
+ let phantom_packet = build_failure_packet(phantom_ss, *failure_code, &data[..]).encode();
+ let encrypted_phantom_packet = encrypt_failure_packet(phantom_ss, &phantom_packet);
+ encrypt_failure_packet(incoming_packet_shared_secret, &encrypted_phantom_packet.data[..])
+ } else {
+ let packet = build_failure_packet(incoming_packet_shared_secret, *failure_code, &data[..]).encode();
+ encrypt_failure_packet(incoming_packet_shared_secret, &packet)
+ }
+ },
+ HTLCFailReason::LightningError { err } => {
+ encrypt_failure_packet(incoming_packet_shared_secret, &err.data)
+ }
+ }
+ }
+
+ pub(super) fn decode_onion_failure<T: secp256k1::Signing, L: Deref>(
+ &self, secp_ctx: &Secp256k1<T>, logger: &L, htlc_source: &HTLCSource
+ ) -> (Option<NetworkUpdate>, Option<u64>, bool, Option<u16>, Option<Vec<u8>>)
+ where L::Target: Logger {
+ match self {
+ HTLCFailReason::LightningError { ref err } => {
+ process_onion_failure(secp_ctx, logger, &htlc_source, err.data.clone())
+ },
+ HTLCFailReason::Reason { ref failure_code, ref data, .. } => {
+ // we get a fail_malformed_htlc from the first hop
+ // TODO: We'd like to generate a NetworkUpdate for temporary
+ // failures here, but that would be insufficient as find_route
+ // generally ignores its view of our own channels as we provide them via
+ // ChannelDetails.
+ if let &HTLCSource::OutboundRoute { ref path, .. } = htlc_source {
+ (None, Some(path.first().unwrap().short_channel_id), true, Some(*failure_code), Some(data.clone()))
+ } else { unreachable!(); }
+ }
+ }
+ }
+}
+