From 00607a5286751edd10c86f9fe6ce0d656d1e3ece Mon Sep 17 00:00:00 2001 From: Matt Corallo Date: Mon, 31 Oct 2022 03:23:02 +0000 Subject: [PATCH] Add missing break when scoring a path with a missing channel If we send payments over a path where a channel ended up being closed, we'll remove it before we call `ProbabilisticPaymentScorer::payment_path_failed`. This should be fine, except that `payment_path_failed` does not break out of its scoring loop if a channel is missing, causing it to assign a minimum available-liquidity of the payment amount even to channels which our attempt never arrived at. The fix is simple - add the missing check and break. --- lightning/src/routing/scoring.rs | 116 ++++++++++++++++++++++--------- 1 file changed, 83 insertions(+), 33 deletions(-) diff --git a/lightning/src/routing/scoring.rs b/lightning/src/routing/scoring.rs index 5b829f61..860f3cb1 100644 --- a/lightning/src/routing/scoring.rs +++ b/lightning/src/routing/scoring.rs @@ -1143,31 +1143,32 @@ impl>, L: Deref, T: Time> Score for Probabilis .get(&hop.short_channel_id) .and_then(|channel| channel.as_directed_to(&target)); - if hop.short_channel_id == short_channel_id && hop_idx == 0 { + let at_failed_channel = hop.short_channel_id == short_channel_id; + if at_failed_channel && hop_idx == 0 { log_warn!(self.logger, "Payment failed at the first hop - we do not attempt to learn channel info in such cases as we can directly observe local state.\n\tBecause we know the local state, we should generally not see failures here - this may be an indication that your channel peer on channel {} is broken and you may wish to close the channel.", hop.short_channel_id); } // Only score announced channels. if let Some((channel, source)) = channel_directed_from_source { let capacity_msat = channel.effective_capacity().as_msat(); - if hop.short_channel_id == short_channel_id { + if at_failed_channel { self.channel_liquidities .entry(hop.short_channel_id) .or_insert_with(ChannelLiquidity::new) .as_directed_mut(source, &target, capacity_msat, &self.params) .failed_at_channel(amount_msat, format_args!("SCID {}, towards {:?}", hop.short_channel_id, target), &self.logger); - break; + } else { + self.channel_liquidities + .entry(hop.short_channel_id) + .or_insert_with(ChannelLiquidity::new) + .as_directed_mut(source, &target, capacity_msat, &self.params) + .failed_downstream(amount_msat, format_args!("SCID {}, towards {:?}", hop.short_channel_id, target), &self.logger); } - - self.channel_liquidities - .entry(hop.short_channel_id) - .or_insert_with(ChannelLiquidity::new) - .as_directed_mut(source, &target, capacity_msat, &self.params) - .failed_downstream(amount_msat, format_args!("SCID {}, towards {:?}", hop.short_channel_id, target), &self.logger); } else { log_debug!(self.logger, "Not able to penalize channel with SCID {} as we do not have graph info for it (likely a route-hint last-hop).", hop.short_channel_id); } + if at_failed_channel { break; } } } @@ -1745,32 +1746,22 @@ mod tests { network_graph.update_channel(&signed_update).unwrap(); } + fn path_hop(pubkey: PublicKey, short_channel_id: u64, fee_msat: u64) -> RouteHop { + RouteHop { + pubkey, + node_features: channelmanager::provided_node_features(), + short_channel_id, + channel_features: channelmanager::provided_channel_features(), + fee_msat, + cltv_expiry_delta: 18, + } + } + fn payment_path_for_amount(amount_msat: u64) -> Vec { vec![ - RouteHop { - pubkey: source_pubkey(), - node_features: channelmanager::provided_node_features(), - short_channel_id: 41, - channel_features: channelmanager::provided_channel_features(), - fee_msat: 1, - cltv_expiry_delta: 18, - }, - RouteHop { - pubkey: target_pubkey(), - node_features: channelmanager::provided_node_features(), - short_channel_id: 42, - channel_features: channelmanager::provided_channel_features(), - fee_msat: 2, - cltv_expiry_delta: 18, - }, - RouteHop { - pubkey: recipient_pubkey(), - node_features: channelmanager::provided_node_features(), - short_channel_id: 43, - channel_features: channelmanager::provided_channel_features(), - fee_msat: amount_msat, - cltv_expiry_delta: 18, - }, + path_hop(source_pubkey(), 41, 1), + path_hop(target_pubkey(), 42, 2), + path_hop(recipient_pubkey(), 43, amount_msat), ] } @@ -2145,6 +2136,65 @@ mod tests { assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), u64::max_value()); } + #[test] + fn ignores_channels_after_removed_failed_channel() { + // Previously, if we'd tried to send over a channel which was removed from the network + // graph before we call `payment_path_failed` (which is the default if the we get a "no + // such channel" error in the `InvoicePayer`), we would call `failed_downstream` on all + // channels in the route, even ones which they payment never reached. This tests to ensure + // we do not score such channels. + let secp_ctx = Secp256k1::new(); + let logger = TestLogger::new(); + let genesis_hash = genesis_block(Network::Testnet).header.block_hash(); + let mut network_graph = NetworkGraph::new(genesis_hash, &logger); + let secret_a = SecretKey::from_slice(&[42; 32]).unwrap(); + let secret_b = SecretKey::from_slice(&[43; 32]).unwrap(); + let secret_c = SecretKey::from_slice(&[44; 32]).unwrap(); + let secret_d = SecretKey::from_slice(&[45; 32]).unwrap(); + add_channel(&mut network_graph, 42, secret_a, secret_b); + // Don't add the channel from B -> C. + add_channel(&mut network_graph, 44, secret_c, secret_d); + + let pub_a = PublicKey::from_secret_key(&secp_ctx, &secret_a); + let pub_b = PublicKey::from_secret_key(&secp_ctx, &secret_b); + let pub_c = PublicKey::from_secret_key(&secp_ctx, &secret_c); + let pub_d = PublicKey::from_secret_key(&secp_ctx, &secret_d); + + let path = vec![ + path_hop(pub_b, 42, 1), + path_hop(pub_c, 43, 2), + path_hop(pub_d, 44, 100), + ]; + + let node_a = NodeId::from_pubkey(&pub_a); + let node_b = NodeId::from_pubkey(&pub_b); + let node_c = NodeId::from_pubkey(&pub_c); + let node_d = NodeId::from_pubkey(&pub_d); + + let params = ProbabilisticScoringParameters { + liquidity_penalty_multiplier_msat: 1_000, + ..ProbabilisticScoringParameters::zero_penalty() + }; + let mut scorer = ProbabilisticScorer::new(params, &network_graph, &logger); + + let usage = ChannelUsage { + amount_msat: 250, + inflight_htlc_msat: 0, + effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_000, htlc_maximum_msat: 1_000 }, + }; + assert_eq!(scorer.channel_penalty_msat(42, &node_a, &node_b, usage), 128); + // Note that a default liquidity bound is used for B -> C as no channel exists + assert_eq!(scorer.channel_penalty_msat(43, &node_b, &node_c, usage), 128); + assert_eq!(scorer.channel_penalty_msat(44, &node_c, &node_d, usage), 128); + + scorer.payment_path_failed(&path.iter().collect::>(), 43); + + assert_eq!(scorer.channel_penalty_msat(42, &node_a, &node_b, usage), 80); + // Note that a default liquidity bound is used for B -> C as no channel exists + assert_eq!(scorer.channel_penalty_msat(43, &node_b, &node_c, usage), 128); + assert_eq!(scorer.channel_penalty_msat(44, &node_c, &node_d, usage), 128); + } + #[test] fn reduces_liquidity_upper_bound_along_path_on_success() { let logger = TestLogger::new(); -- 2.30.2