/// Process failure we got back from upstream on a payment we sent (implying htlc_source is an
/// OutboundRoute).
-/// Returns update, a boolean indicating that the payment itself failed, and the error code.
+/// Returns update, a boolean indicating that the payment itself failed, the short channel id of
+/// the responsible channel, and the error code.
#[inline]
-pub(super) fn process_onion_failure<T: secp256k1::Signing, L: Deref>(secp_ctx: &Secp256k1<T>, logger: &L, htlc_source: &HTLCSource, mut packet_decrypted: Vec<u8>) -> (Option<NetworkUpdate>, bool, Option<u16>, Option<Vec<u8>>) where L::Target: Logger {
+pub(super) fn process_onion_failure<T: secp256k1::Signing, L: Deref>(secp_ctx: &Secp256k1<T>, logger: &L, htlc_source: &HTLCSource, mut packet_decrypted: Vec<u8>) -> (Option<NetworkUpdate>, Option<u64>, bool, Option<u16>, Option<Vec<u8>>) where L::Target: Logger {
if let &HTLCSource::OutboundRoute { ref path, ref session_priv, ref first_hop_htlc_msat, .. } = htlc_source {
let mut res = None;
let mut htlc_msat = *first_hop_htlc_msat;
chacha.process(&packet_decrypted, &mut decryption_tmp[..]);
packet_decrypted = decryption_tmp;
+ // The failing hop includes either the inbound channel to the recipient or the outbound
+ // channel from the current hop (i.e., the next hop's inbound channel).
is_from_final_node = route_hop_idx + 1 == path.len();
+ let failing_route_hop = if is_from_final_node { route_hop } else { &path[route_hop_idx + 1] };
if let Ok(err_packet) = msgs::DecodedOnionErrorPacket::read(&mut Cursor::new(&packet_decrypted)) {
let um = gen_um_from_shared_secret(&shared_secret[..]);
} && is_from_final_node; // PERM bit observed below even if this error is from the intermediate nodes
let mut network_update = None;
+ let mut short_channel_id = None;
if error_code & NODE == NODE {
- network_update = Some(NetworkUpdate::NodeFailure { node_id: route_hop.pubkey, is_permanent: error_code & PERM == PERM });
+ let is_permanent = error_code & PERM == PERM;
+ network_update = Some(NetworkUpdate::NodeFailure { node_id: route_hop.pubkey, is_permanent });
+ short_channel_id = Some(route_hop.short_channel_id);
}
else if error_code & PERM == PERM {
- network_update = if payment_failed { None } else {
- let failing_route_hop = if is_from_final_node { route_hop } else { &path[route_hop_idx + 1] };
- Some(NetworkUpdate::ChannelClosed {
+ if !payment_failed {
+ network_update = Some(NetworkUpdate::ChannelClosed {
short_channel_id: failing_route_hop.short_channel_id,
is_permanent: true,
- })
- };
+ });
+ short_channel_id = Some(failing_route_hop.short_channel_id);
+ }
}
else if error_code & UPDATE == UPDATE {
if let Some(update_len_slice) = err_packet.failuremsg.get(debug_field_size+2..debug_field_size+4) {
20 => chan_update.contents.flags & 2 == 0,
_ => false, // unknown error code; take channel_update as valid
};
- network_update = if is_chan_update_invalid {
+ if is_chan_update_invalid {
// This probably indicates the node which forwarded
// to the node in question corrupted something.
- Some(NetworkUpdate::ChannelClosed {
+ network_update = Some(NetworkUpdate::ChannelClosed {
short_channel_id: route_hop.short_channel_id,
is_permanent: true,
- })
+ });
} else {
- Some(NetworkUpdate::ChannelUpdateMessage {
+ // Make sure the ChannelUpdate contains the expected
+ // 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);
+ }
+ network_update = Some(NetworkUpdate::ChannelUpdateMessage {
msg: chan_update,
})
};
is_permanent: true,
});
}
- } else if !payment_failed {
+ if short_channel_id.is_none() {
+ short_channel_id = Some(route_hop.short_channel_id);
+ }
+ } else if payment_failed {
+ // Only blame the hop when a value in the HTLC doesn't match the
+ // corresponding value in the onion.
+ short_channel_id = match error_code & 0xff {
+ 18|19 => Some(route_hop.short_channel_id),
+ _ => None,
+ };
+ } else {
// We can't understand their error messages and they failed to
// forward...they probably can't understand our forwards so its
// really not worth trying any further.
node_id: route_hop.pubkey,
is_permanent: true,
});
+ short_channel_id = Some(route_hop.short_channel_id);
}
// TODO: Here (and a few other places) we assume that BADONION errors
// are always "sourced" from the node previous to the one which failed
// to decode the onion.
- res = Some((network_update, !(error_code & PERM == PERM && is_from_final_node)));
+ res = Some((network_update, short_channel_id, !(error_code & PERM == PERM && is_from_final_node)));
let (description, title) = errors::get_onion_error_description(error_code);
if debug_field_size > 0 && err_packet.failuremsg.len() >= 4 + debug_field_size {
} else {
// Useless packet that we can't use but it passed HMAC, so it
// definitely came from the peer in question
- res = Some((Some(NetworkUpdate::NodeFailure {
+ let network_update = Some(NetworkUpdate::NodeFailure {
node_id: route_hop.pubkey,
is_permanent: true,
- }), !is_from_final_node));
+ });
+ let short_channel_id = Some(route_hop.short_channel_id);
+ res = Some((network_update, short_channel_id, !is_from_final_node));
}
}
}
}).expect("Route that we sent via spontaneously grew invalid keys in the middle of it?");
- if let Some((channel_update, payment_retryable)) = res {
- (channel_update, payment_retryable, error_code_ret, error_packet_ret)
+ if let Some((channel_update, short_channel_id, payment_retryable)) = res {
+ (channel_update, short_channel_id, payment_retryable, error_code_ret, error_packet_ret)
} else {
// only not set either packet unparseable or hmac does not match with any
// payment not retryable only when garbage is from the final node
- (None, !is_from_final_node, None, None)
+ (None, None, !is_from_final_node, None, None)
}
} else { unreachable!(); }
}