pub(super) enum PendingHTLCRouting {
Forward {
onion_packet: msgs::OnionPacket,
- /// The SCID from the onion that we should forward to. This could be a "real" SCID, an
- /// outbound SCID alias, or a phantom node SCID.
+ /// The SCID from the onion that we should forward to. This could be a real SCID or a fake one
+ /// generated using `get_fake_scid` from the scid_utils::fake_scid module.
short_channel_id: u64, // This should be NonZero<u64> eventually when we bump MSRV
},
Receive {
// `total_consistency_lock`
// |
// |__`forward_htlcs`
+// | |
+// | |__`pending_intercepted_htlcs`
// |
// |__`pending_inbound_payments`
// | |
let forwarding_id_opt = 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, &self.genesis_hash) {
+ // phantom or an intercept.
+ if fake_scid::is_valid_phantom(&self.fake_scid_rand_bytes, *short_channel_id, &self.genesis_hash) ||
+ fake_scid::is_valid_intercept(&self.fake_scid_rand_bytes, *short_channel_id, &self.genesis_hash)
+ {
None
} else {
break Some(("Don't have available channel for forwarding as requested.", 0x4000 | 10, None));
fn forward_htlcs(&self, per_source_pending_forwards: &mut [(u64, OutPoint, u128, Vec<(PendingHTLCInfo, u64)>)]) {
for &mut (prev_short_channel_id, prev_funding_outpoint, prev_user_channel_id, ref mut pending_forwards) in per_source_pending_forwards {
let mut forward_event = None;
+ let mut new_intercept_events = Vec::new();
+ let mut failed_intercept_forwards = Vec::new();
if !pending_forwards.is_empty() {
- let mut forward_htlcs = self.forward_htlcs.lock().unwrap();
- if forward_htlcs.is_empty() {
- forward_event = Some(Duration::from_millis(MIN_HTLC_RELAY_HOLDING_CELL_MILLIS))
- }
for (forward_info, prev_htlc_id) in pending_forwards.drain(..) {
- match forward_htlcs.entry(match forward_info.routing {
- PendingHTLCRouting::Forward { short_channel_id, .. } => short_channel_id,
- PendingHTLCRouting::Receive { .. } => 0,
- PendingHTLCRouting::ReceiveKeysend { .. } => 0,
- }) {
+ let scid = match forward_info.routing {
+ PendingHTLCRouting::Forward { short_channel_id, .. } => short_channel_id,
+ PendingHTLCRouting::Receive { .. } => 0,
+ PendingHTLCRouting::ReceiveKeysend { .. } => 0,
+ };
+ // Pull this now to avoid introducing a lock order with `forward_htlcs`.
+ let is_our_scid = self.short_to_chan_info.read().unwrap().contains_key(&scid);
+
+ let mut forward_htlcs = self.forward_htlcs.lock().unwrap();
+ let forward_htlcs_empty = forward_htlcs.is_empty();
+ match forward_htlcs.entry(scid) {
hash_map::Entry::Occupied(mut entry) => {
entry.get_mut().push(HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo {
prev_short_channel_id, prev_funding_outpoint, prev_htlc_id, prev_user_channel_id, forward_info }));
},
hash_map::Entry::Vacant(entry) => {
- entry.insert(vec!(HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo {
- prev_short_channel_id, prev_funding_outpoint, prev_htlc_id, prev_user_channel_id, forward_info })));
+ if !is_our_scid && forward_info.incoming_amt_msat.is_some() &&
+ fake_scid::is_valid_intercept(&self.fake_scid_rand_bytes, scid, &self.genesis_hash)
+ {
+ let intercept_id = InterceptId(Sha256::hash(&forward_info.incoming_shared_secret).into_inner());
+ let mut pending_intercepts = self.pending_intercepted_htlcs.lock().unwrap();
+ match pending_intercepts.entry(intercept_id) {
+ hash_map::Entry::Vacant(entry) => {
+ new_intercept_events.push(events::Event::HTLCIntercepted {
+ requested_next_hop_scid: scid,
+ payment_hash: forward_info.payment_hash,
+ inbound_amount_msat: forward_info.incoming_amt_msat.unwrap(),
+ expected_outbound_amount_msat: forward_info.outgoing_amt_msat,
+ intercept_id
+ });
+ entry.insert(PendingAddHTLCInfo {
+ prev_short_channel_id, prev_funding_outpoint, prev_htlc_id, prev_user_channel_id, forward_info });
+ },
+ hash_map::Entry::Occupied(_) => {
+ log_info!(self.logger, "Failed to forward incoming HTLC: detected duplicate intercepted payment over short channel id {}", scid);
+ 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,
+ phantom_shared_secret: None,
+ });
+
+ failed_intercept_forwards.push((htlc_source, forward_info.payment_hash,
+ HTLCFailReason::Reason { failure_code: 0x4000 | 10, data: Vec::new() },
+ HTLCDestination::InvalidForward { requested_forward_scid: scid },
+ ));
+ }
+ }
+ } else {
+ // We don't want to generate a PendingHTLCsForwardable event if only intercepted
+ // payments are being processed.
+ if forward_htlcs_empty {
+ forward_event = Some(Duration::from_millis(MIN_HTLC_RELAY_HOLDING_CELL_MILLIS));
+ }
+ entry.insert(vec!(HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo {
+ prev_short_channel_id, prev_funding_outpoint, prev_htlc_id, prev_user_channel_id, forward_info })));
+ }
}
}
}
}
+
+ for (htlc_source, payment_hash, failure_reason, destination) in failed_intercept_forwards.drain(..) {
+ self.fail_htlc_backwards_internal(htlc_source, &payment_hash, failure_reason, destination);
+ }
+
+ if !new_intercept_events.is_empty() {
+ let mut events = self.pending_events.lock().unwrap();
+ events.append(&mut new_intercept_events);
+ }
+
match forward_event {
Some(time) => {
let mut pending_events = self.pending_events.lock().unwrap();
projects / rust-lightning / commitdiff