if let Some((err, code, chan_update)) = loop {
let forwarding_id = match id_option {
None => { // unknown_next_peer
+ // Note that this is likely a timing oracle for detecting whether an scid is a
+ // phantom.
+ if fake_scid::is_valid_phantom(&self.fake_scid_rand_bytes, *short_channel_id) {
+ break None
+ }
break Some(("Don't have available channel for forwarding as requested.", 0x4000 | 10, None));
},
Some(id) => id.clone(),
let mut new_events = Vec::new();
let mut failed_forwards = Vec::new();
+ let mut phantom_receives: Vec<(u64, OutPoint, Vec<(PendingHTLCInfo, u64)>)> = Vec::new();
let mut handle_errors = Vec::new();
{
let mut channel_state_lock = self.channel_state.lock().unwrap();
let forward_chan_id = match channel_state.short_to_id.get(&short_chan_id) {
Some(chan_id) => chan_id.clone(),
None => {
- failed_forwards.reserve(pending_forwards.len());
for forward_info in pending_forwards.drain(..) {
match forward_info {
- HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info,
- prev_funding_outpoint } => {
- let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData {
- short_channel_id: prev_short_channel_id,
- outpoint: prev_funding_outpoint,
- htlc_id: prev_htlc_id,
- incoming_packet_shared_secret: forward_info.incoming_shared_secret,
- });
- failed_forwards.push((htlc_source, forward_info.payment_hash,
- HTLCFailReason::Reason { failure_code: 0x4000 | 10, data: Vec::new() }
- ));
- },
+ HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info: PendingHTLCInfo {
+ routing, incoming_shared_secret, payment_hash, amt_to_forward, outgoing_cltv_value },
+ prev_funding_outpoint } => {
+ macro_rules! fail_forward {
+ ($msg: expr, $err_code: expr, $err_data: expr) => {
+ {
+ log_info!(self.logger, "Failed to accept/forward incoming HTLC: {}", $msg);
+ let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData {
+ short_channel_id: short_chan_id,
+ outpoint: prev_funding_outpoint,
+ htlc_id: prev_htlc_id,
+ incoming_packet_shared_secret: incoming_shared_secret,
+ });
+ failed_forwards.push((htlc_source, payment_hash,
+ HTLCFailReason::Reason { failure_code: $err_code, data: $err_data }
+ ));
+ continue;
+ }
+ }
+ }
+ if let PendingHTLCRouting::Forward { onion_packet, .. } = routing {
+ let phantom_secret_res = self.keys_manager.get_node_secret(Recipient::PhantomNode);
+ if phantom_secret_res.is_ok() && fake_scid::is_valid_phantom(&self.fake_scid_rand_bytes, short_chan_id) {
+ let shared_secret = {
+ let mut arr = [0; 32];
+ arr.copy_from_slice(&SharedSecret::new(&onion_packet.public_key.unwrap(), &phantom_secret_res.unwrap())[..]);
+ arr
+ };
+ let next_hop = match onion_utils::decode_next_hop(shared_secret, &onion_packet.hop_data, onion_packet.hmac, payment_hash) {
+ Ok(res) => res,
+ Err(onion_utils::OnionDecodeErr::Malformed { err_msg, err_code }) => {
+ fail_forward!(err_msg, err_code, Vec::new());
+ },
+ Err(onion_utils::OnionDecodeErr::Relay { err_msg, err_code }) => {
+ fail_forward!(err_msg, err_code, Vec::new());
+ },
+ };
+ match next_hop {
+ onion_utils::Hop::Receive(hop_data) => {
+ match self.construct_recv_pending_htlc_info(hop_data, shared_secret, payment_hash, amt_to_forward, outgoing_cltv_value) {
+ Ok(info) => phantom_receives.push((prev_short_channel_id, prev_funding_outpoint, vec![(info, prev_htlc_id)])),
+ Err(ReceiveError { err_code, err_data, msg }) => fail_forward!(msg, err_code, err_data)
+ }
+ },
+ _ => panic!(),
+ }
+ } else {
+ fail_forward!(format!("Unknown short channel id {} for forward HTLC", short_chan_id), 0x4000 | 10, Vec::new());
+ }
+ } else {
+ fail_forward!(format!("Unknown short channel id {} for forward HTLC", short_chan_id), 0x4000 | 10, Vec::new());
+ }
+ },
HTLCForwardInfo::FailHTLC { .. } => {
// Channel went away before we could fail it. This implies
// the channel is now on chain and our counterparty is
// trying to broadcast the HTLC-Timeout, but that's their
// problem, not ours.
+ //
+ // `fail_htlc_backwards_internal` is never called for
+ // phantom payments, so this is unreachable for them.
}
}
}
for (htlc_source, payment_hash, failure_reason) in failed_forwards.drain(..) {
self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), htlc_source, &payment_hash, failure_reason);
}
+ self.forward_htlcs(&mut phantom_receives);
for (counterparty_node_id, err) in handle_errors.drain(..) {
let _ = handle_error!(self, err, counterparty_node_id);