]> git.bitcoin.ninja Git - rust-lightning/commitdiff
Abide by route hint max_htlc in pathfinding
authorValentine Wallace <vwallace@protonmail.com>
Wed, 17 May 2023 22:28:06 +0000 (18:28 -0400)
committerValentine Wallace <vwallace@protonmail.com>
Tue, 6 Jun 2023 13:12:18 +0000 (15:12 +0200)
lightning/src/routing/gossip.rs
lightning/src/routing/router.rs
lightning/src/routing/scoring.rs

index 9a9a932968cb5f791cdbaa49129cb0af15140864..14bf81baea8b752bc57b69688faf4dc2e95810da 100644 (file)
@@ -1033,6 +1033,11 @@ pub enum EffectiveCapacity {
        /// A capacity sufficient to route any payment, typically used for private channels provided by
        /// an invoice.
        Infinite,
+       /// The maximum HTLC amount as provided by an invoice route hint.
+       HintMaxHTLC {
+               /// The maximum HTLC amount denominated in millisatoshi.
+               amount_msat: u64,
+       },
        /// A capacity that is unknown possibly because either the chain state is unavailable to know
        /// the total capacity or the `htlc_maximum_msat` was not advertised on the gossip network.
        Unknown,
@@ -1049,6 +1054,7 @@ impl EffectiveCapacity {
                        EffectiveCapacity::ExactLiquidity { liquidity_msat } => *liquidity_msat,
                        EffectiveCapacity::AdvertisedMaxHTLC { amount_msat } => *amount_msat,
                        EffectiveCapacity::Total { capacity_msat, .. } => *capacity_msat,
+                       EffectiveCapacity::HintMaxHTLC { amount_msat } => *amount_msat,
                        EffectiveCapacity::Infinite => u64::max_value(),
                        EffectiveCapacity::Unknown => UNKNOWN_CHANNEL_CAPACITY_MSAT,
                }
index 140148ca354b2e6f5219d53b71795ae278adf927..e6eb1494515eba8d63dda712ecfbaedd880fb2f7 100644 (file)
@@ -951,7 +951,10 @@ impl<'a> CandidateRouteHop<'a> {
                                liquidity_msat: details.next_outbound_htlc_limit_msat,
                        },
                        CandidateRouteHop::PublicHop { info, .. } => info.effective_capacity(),
-                       CandidateRouteHop::PrivateHop { .. } => EffectiveCapacity::Infinite,
+                       CandidateRouteHop::PrivateHop { hint: RouteHintHop { htlc_maximum_msat: Some(max), .. }} =>
+                               EffectiveCapacity::HintMaxHTLC { amount_msat: *max },
+                       CandidateRouteHop::PrivateHop { hint: RouteHintHop { htlc_maximum_msat: None, .. }} =>
+                               EffectiveCapacity::Infinite,
                }
        }
 }
@@ -965,6 +968,9 @@ fn max_htlc_from_capacity(capacity: EffectiveCapacity, max_channel_saturation_po
                EffectiveCapacity::Unknown => EffectiveCapacity::Unknown.as_msat(),
                EffectiveCapacity::AdvertisedMaxHTLC { amount_msat } =>
                        amount_msat.checked_shr(saturation_shift).unwrap_or(0),
+               // Treat htlc_maximum_msat from a route hint as an exact liquidity amount, since the invoice is
+               // expected to have been generated from up-to-date capacity information.
+               EffectiveCapacity::HintMaxHTLC { amount_msat } => amount_msat,
                EffectiveCapacity::Total { capacity_msat, htlc_maximum_msat } =>
                        cmp::min(capacity_msat.checked_shr(saturation_shift).unwrap_or(0), htlc_maximum_msat),
        }
@@ -1470,8 +1476,9 @@ where L::Target: Logger {
                ( $candidate: expr, $src_node_id: expr, $dest_node_id: expr, $next_hops_fee_msat: expr,
                        $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr,
                        $next_hops_path_penalty_msat: expr, $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => { {
-                       // We "return" whether we updated the path at the end, via this:
-                       let mut did_add_update_path_to_src_node = false;
+                       // We "return" whether we updated the path at the end, and how much we can route via
+                       // this channel, via this:
+                       let mut did_add_update_path_to_src_node = None;
                        // Channels to self should not be used. This is more of belt-and-suspenders, because in
                        // practice these cases should be caught earlier:
                        // - for regular channels at channel announcement (TODO)
@@ -1652,7 +1659,7 @@ where L::Target: Logger {
                                                                {
                                                                        old_entry.value_contribution_msat = value_contribution_msat;
                                                                }
-                                                               did_add_update_path_to_src_node = true;
+                                                               did_add_update_path_to_src_node = Some(value_contribution_msat);
                                                        } else if old_entry.was_processed && new_cost < old_cost {
                                                                #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
                                                                {
@@ -1773,7 +1780,7 @@ where L::Target: Logger {
                        for details in first_channels {
                                let candidate = CandidateRouteHop::FirstHop { details };
                                let added = add_entry!(candidate, our_node_id, payee, 0, path_value_msat,
-                                                                       0, 0u64, 0, 0);
+                                                                       0, 0u64, 0, 0).is_some();
                                log_trace!(logger, "{} direct route to payee via SCID {}",
                                                if added { "Added" } else { "Skipped" }, candidate.short_channel_id());
                        }
@@ -1820,6 +1827,7 @@ where L::Target: Logger {
                                let mut aggregate_next_hops_path_penalty_msat: u64 = 0;
                                let mut aggregate_next_hops_cltv_delta: u32 = 0;
                                let mut aggregate_next_hops_path_length: u8 = 0;
+                               let mut aggregate_path_contribution_msat = path_value_msat;
 
                                for (idx, (hop, prev_hop_id)) in hop_iter.zip(prev_hop_iter).enumerate() {
                                        let source = NodeId::from_pubkey(&hop.src_node_id);
@@ -1833,10 +1841,13 @@ where L::Target: Logger {
                                                })
                                                .unwrap_or_else(|| CandidateRouteHop::PrivateHop { hint: hop });
 
-                                       if !add_entry!(candidate, source, target, aggregate_next_hops_fee_msat,
-                                                               path_value_msat, aggregate_next_hops_path_htlc_minimum_msat,
-                                                               aggregate_next_hops_path_penalty_msat,
-                                                               aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length) {
+                                       if let Some(hop_used_msat) = add_entry!(candidate, source, 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)
+                                       {
+                                               aggregate_path_contribution_msat = hop_used_msat;
+                                       } else {
                                                // If this hop was not used then there is no use checking the preceding
                                                // hops in the RouteHint. We can break by just searching for a direct
                                                // channel between last checked hop and first_hop_targets.
@@ -1865,12 +1876,11 @@ where L::Target: Logger {
                                        // Searching for a direct channel between last checked hop and first_hop_targets
                                        if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&prev_hop_id)) {
                                                for details in first_channels {
-                                                       let candidate = CandidateRouteHop::FirstHop { details };
-                                                       add_entry!(candidate, our_node_id, NodeId::from_pubkey(&prev_hop_id),
-                                                               aggregate_next_hops_fee_msat, path_value_msat,
-                                                               aggregate_next_hops_path_htlc_minimum_msat,
-                                                               aggregate_next_hops_path_penalty_msat, aggregate_next_hops_cltv_delta,
-                                                               aggregate_next_hops_path_length);
+                                                       let first_hop_candidate = CandidateRouteHop::FirstHop { details };
+                                                       add_entry!(first_hop_candidate, our_node_id, NodeId::from_pubkey(&prev_hop_id),
+                                                               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);
                                                }
                                        }
 
@@ -1905,10 +1915,11 @@ where L::Target: Logger {
                                                // path.
                                                if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&hop.src_node_id)) {
                                                        for details in first_channels {
-                                                               let candidate = CandidateRouteHop::FirstHop { details };
-                                                               add_entry!(candidate, our_node_id,
+                                                               let first_hop_candidate = CandidateRouteHop::FirstHop { details };
+                                                               add_entry!(first_hop_candidate, our_node_id,
                                                                        NodeId::from_pubkey(&hop.src_node_id),
-                                                                       aggregate_next_hops_fee_msat, path_value_msat,
+                                                                       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,
@@ -5906,6 +5917,130 @@ mod tests {
                assert!(route.is_ok());
        }
 
+       #[test]
+       fn abide_by_route_hint_max_htlc() {
+               // Check that we abide by any htlc_maximum_msat provided in the route hints of the payment
+               // params in the final route.
+               let (secp_ctx, network_graph, _, _, logger) = build_graph();
+               let netgraph = network_graph.read_only();
+               let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
+               let scorer = ln_test_utils::TestScorer::new();
+               let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
+               let random_seed_bytes = keys_manager.get_secure_random_bytes();
+               let config = UserConfig::default();
+
+               let max_htlc_msat = 50_000;
+               let route_hint_1 = RouteHint(vec![RouteHintHop {
+                       src_node_id: nodes[2],
+                       short_channel_id: 42,
+                       fees: RoutingFees {
+                               base_msat: 100,
+                               proportional_millionths: 0,
+                       },
+                       cltv_expiry_delta: 10,
+                       htlc_minimum_msat: None,
+                       htlc_maximum_msat: Some(max_htlc_msat),
+               }]);
+               let dest_node_id = ln_test_utils::pubkey(42);
+               let payment_params = PaymentParameters::from_node_id(dest_node_id, 42)
+                       .with_route_hints(vec![route_hint_1.clone()]).unwrap()
+                       .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
+
+               // Make sure we'll error if our route hints don't have enough liquidity according to their
+               // htlc_maximum_msat.
+               if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id,
+                       &payment_params, &netgraph, None, max_htlc_msat + 1, Arc::clone(&logger), &scorer, &(),
+                       &random_seed_bytes)
+               {
+                       assert_eq!(err, "Failed to find a sufficient route to the given destination");
+               } else { panic!(); }
+
+               // Make sure we'll split an MPP payment across route hints if their htlc_maximum_msat warrants.
+               let mut route_hint_2 = route_hint_1.clone();
+               route_hint_2.0[0].short_channel_id = 43;
+               let payment_params = PaymentParameters::from_node_id(dest_node_id, 42)
+                       .with_route_hints(vec![route_hint_1, route_hint_2]).unwrap()
+                       .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
+               let route = get_route(&our_id, &payment_params, &netgraph, None, max_htlc_msat + 1,
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               assert_eq!(route.paths.len(), 2);
+               assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
+               assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
+       }
+
+       #[test]
+       fn direct_channel_to_hints_with_max_htlc() {
+               // Check that if we have a first hop channel peer that's connected to multiple provided route
+               // hints, that we properly split the payment between the route hints if needed.
+               let logger = Arc::new(ln_test_utils::TestLogger::new());
+               let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
+               let scorer = ln_test_utils::TestScorer::new();
+               let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
+               let random_seed_bytes = keys_manager.get_secure_random_bytes();
+               let config = UserConfig::default();
+
+               let our_node_id = ln_test_utils::pubkey(42);
+               let intermed_node_id = ln_test_utils::pubkey(43);
+               let first_hop = vec![get_channel_details(Some(42), intermed_node_id, InitFeatures::from_le_bytes(vec![0b11]), 10_000_000)];
+
+               let amt_msat = 900_000;
+               let max_htlc_msat = 500_000;
+               let route_hint_1 = RouteHint(vec![RouteHintHop {
+                       src_node_id: intermed_node_id,
+                       short_channel_id: 44,
+                       fees: RoutingFees {
+                               base_msat: 100,
+                               proportional_millionths: 0,
+                       },
+                       cltv_expiry_delta: 10,
+                       htlc_minimum_msat: None,
+                       htlc_maximum_msat: Some(max_htlc_msat),
+               }, RouteHintHop {
+                       src_node_id: intermed_node_id,
+                       short_channel_id: 45,
+                       fees: RoutingFees {
+                               base_msat: 100,
+                               proportional_millionths: 0,
+                       },
+                       cltv_expiry_delta: 10,
+                       htlc_minimum_msat: None,
+                       // Check that later route hint max htlcs don't override earlier ones
+                       htlc_maximum_msat: Some(max_htlc_msat - 50),
+               }]);
+               let mut route_hint_2 = route_hint_1.clone();
+               route_hint_2.0[0].short_channel_id = 46;
+               route_hint_2.0[1].short_channel_id = 47;
+               let dest_node_id = ln_test_utils::pubkey(44);
+               let payment_params = PaymentParameters::from_node_id(dest_node_id, 42)
+                       .with_route_hints(vec![route_hint_1, route_hint_2]).unwrap()
+                       .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
+
+               let route = get_route(&our_node_id, &payment_params, &network_graph.read_only(),
+                       Some(&first_hop.iter().collect::<Vec<_>>()), amt_msat, Arc::clone(&logger), &scorer, &(),
+                       &random_seed_bytes).unwrap();
+               assert_eq!(route.paths.len(), 2);
+               assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
+               assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
+               assert_eq!(route.get_total_amount(), amt_msat);
+
+               // Re-run but with two first hop channels connected to the same route hint peers that must be
+               // split between.
+               let first_hops = vec![
+                       get_channel_details(Some(42), intermed_node_id, InitFeatures::from_le_bytes(vec![0b11]), amt_msat - 10),
+                       get_channel_details(Some(43), intermed_node_id, InitFeatures::from_le_bytes(vec![0b11]), amt_msat - 10),
+               ];
+               let route = get_route(&our_node_id, &payment_params, &network_graph.read_only(),
+                       Some(&first_hops.iter().collect::<Vec<_>>()), amt_msat, Arc::clone(&logger), &scorer, &(),
+                       &random_seed_bytes).unwrap();
+               // TODO: `get_route` returns a suboptimal route here because first hop channels are not
+               // resorted on the fly when processing route hints.
+               assert_eq!(route.paths.len(), 3);
+               assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
+               assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
+               assert!(route.paths[2].hops.last().unwrap().fee_msat <= max_htlc_msat);
+               assert_eq!(route.get_total_amount(), amt_msat);
+       }
+
        #[test]
        fn blinded_route_ser() {
                let blinded_path_1 = BlindedPath {
index 2ffb3251b9fb2e36ffc82408940ce57f3a7a3ca6..ee9c3d0c47356ddc53d9f7efc21f368b1ef77743 100644 (file)
@@ -1243,8 +1243,10 @@ impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, T: Time> Score for Probabilis
 
                let mut anti_probing_penalty_msat = 0;
                match usage.effective_capacity {
-                       EffectiveCapacity::ExactLiquidity { liquidity_msat } => {
-                               if usage.amount_msat > liquidity_msat {
+                       EffectiveCapacity::ExactLiquidity { liquidity_msat: amount_msat } |
+                               EffectiveCapacity::HintMaxHTLC { amount_msat } =>
+                       {
+                               if usage.amount_msat > amount_msat {
                                        return u64::max_value();
                                } else {
                                        return base_penalty_msat;