From c480b0c857d0999c12c1c2507a5d8c93592d91cc Mon Sep 17 00:00:00 2001 From: Elias Rohrer Date: Fri, 22 Sep 2023 16:38:30 +0200 Subject: [PATCH] Avoid adding duplicate hint candidates if they are first hops If we have a direct channel to a node generating an invoice with route hints, we'd previously happily add multiple candidates that all refer to the same channel. To keep our candidate set small and unify our tracking where possible, we now check if its `short_channel_id` is an `outbound_scid_alias` of any of our first hops and refrain from adding another candidate if it's the case. --- lightning/src/routing/router.rs | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/lightning/src/routing/router.rs b/lightning/src/routing/router.rs index 0a8ee4258..940b846bb 100644 --- a/lightning/src/routing/router.rs +++ b/lightning/src/routing/router.rs @@ -2167,6 +2167,15 @@ where L::Target: Logger { for (idx, (hop, prev_hop_id)) in hop_iter.zip(prev_hop_iter).enumerate() { let source = NodeId::from_pubkey(&hop.src_node_id); let target = NodeId::from_pubkey(&prev_hop_id); + + if let Some(first_channels) = first_hop_targets.get(&target) { + if first_channels.iter().any(|d| d.outbound_scid_alias == Some(hop.short_channel_id)) { + log_trace!(logger, "Ignoring route hint with SCID {} (and any previous) due to it being a direct channel of ours.", + hop.short_channel_id); + break; + } + } + let candidate = network_channels .get(&hop.short_channel_id) .and_then(|channel| channel.as_directed_to(&target)) @@ -2210,12 +2219,12 @@ where L::Target: Logger { .saturating_add(1); // Searching for a direct channel between last checked hop and first_hop_targets - if let Some(first_channels) = first_hop_targets.get_mut(&NodeId::from_pubkey(&prev_hop_id)) { + if let Some(first_channels) = first_hop_targets.get_mut(&target) { sort_first_hop_channels(first_channels, &used_liquidities, recommended_value_msat, our_node_pubkey); for details in first_channels { let first_hop_candidate = CandidateRouteHop::FirstHop { details }; - add_entry!(first_hop_candidate, our_node_id, NodeId::from_pubkey(&prev_hop_id), + add_entry!(first_hop_candidate, our_node_id, target, aggregate_next_hops_fee_msat, aggregate_path_contribution_msat, aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat, aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length); -- 2.39.5