]> git.bitcoin.ninja Git - rust-lightning/commitdiff
Allow nodes to be avoided during pathfinding
authorElias Rohrer <ero@tnull.de>
Sat, 18 Jun 2022 14:24:37 +0000 (16:24 +0200)
committerElias Rohrer <ero@tnull.de>
Fri, 24 Jun 2022 06:31:41 +0000 (08:31 +0200)
Users may want to - for whatever reasons - prevent payments to be routed
over certain nodes. This change therefore allows to add `NodeId`s to a
list of banned nodes, which then will be avoided during path finding.

lightning/src/routing/router.rs
lightning/src/routing/scoring.rs

index 634282d6c4b1f202fd0867312fc3dd83fc9b57fb..26e00319fbdb3b4f2e45fab8d35f51fea576773f 100644 (file)
@@ -1878,7 +1878,7 @@ mod tests {
        use routing::router::{get_route, build_route_from_hops_internal, add_random_cltv_offset, default_node_features,
                PaymentParameters, Route, RouteHint, RouteHintHop, RouteHop, RoutingFees,
                DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA, MAX_PATH_LENGTH_ESTIMATE};
-       use routing::scoring::{ChannelUsage, Score};
+       use routing::scoring::{ChannelUsage, Score, ProbabilisticScorer, ProbabilisticScoringParameters};
        use chain::transaction::OutPoint;
        use chain::keysinterface::KeysInterface;
        use ln::features::{ChannelFeatures, InitFeatures, InvoiceFeatures, NodeFeatures};
@@ -5713,6 +5713,33 @@ mod tests {
                        }
                }
        }
+
+       #[test]
+       fn avoids_banned_nodes() {
+               let (secp_ctx, network_graph, _, _, logger) = build_line_graph();
+               let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
+
+               let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
+               let random_seed_bytes = keys_manager.get_secure_random_bytes();
+
+               let scorer_params = ProbabilisticScoringParameters::default();
+               let mut scorer = ProbabilisticScorer::new(scorer_params, Arc::clone(&network_graph), Arc::clone(&logger));
+
+               // First check we can get a route.
+               let payment_params = PaymentParameters::from_node_id(nodes[10]);
+               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes);
+               assert!(route.is_ok());
+
+               // Then check that we can't get a route if we ban an intermediate node.
+               scorer.add_banned(&NodeId::from_pubkey(&nodes[3]));
+               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes);
+               assert!(route.is_err());
+
+               // Finally make sure we can route again, when we remove the ban.
+               scorer.remove_banned(&NodeId::from_pubkey(&nodes[3]));
+               let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes);
+               assert!(route.is_ok());
+       }
 }
 
 #[cfg(all(test, not(feature = "no-std")))]
index f7fe5863838f2aefbab77e173fe7fe4ae72c4c0d..72c27fa238b7e5ec22fcd6cfc8025fa7d6c560c7 100644 (file)
@@ -306,7 +306,7 @@ where L::Target: Logger {
 ///
 /// Used to configure base, liquidity, and amount penalties, the sum of which comprises the channel
 /// penalty (i.e., the amount in msats willing to be paid to avoid routing through the channel).
-#[derive(Clone, Copy)]
+#[derive(Clone)]
 pub struct ProbabilisticScoringParameters {
        /// A fixed penalty in msats to apply to each channel.
        ///
@@ -361,6 +361,11 @@ pub struct ProbabilisticScoringParameters {
        ///
        /// Default value: 256 msat
        pub amount_penalty_multiplier_msat: u64,
+
+       /// A list of nodes that won't be considered during path finding.
+       ///
+       /// (C-not exported)
+       pub banned_nodes: HashSet<NodeId>,
 }
 
 /// Accounting for channel liquidity balance uncertainty.
@@ -451,6 +456,22 @@ impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, T: Time> ProbabilisticScorerU
                }
                None
        }
+
+       /// Marks the node with the given `node_id` as banned, i.e.,
+       /// it will be avoided during path finding.
+       pub fn add_banned(&mut self, node_id: &NodeId) {
+               self.params.banned_nodes.insert(*node_id);
+       }
+
+       /// Removes the node with the given `node_id` from the list of nodes to avoid.
+       pub fn remove_banned(&mut self, node_id: &NodeId) {
+               self.params.banned_nodes.remove(node_id);
+       }
+
+       /// Clears the list of nodes that are avoided during path finding.
+       pub fn clear_banned(&mut self) {
+               self.params.banned_nodes = HashSet::new();
+       }
 }
 
 impl ProbabilisticScoringParameters {
@@ -461,6 +482,15 @@ impl ProbabilisticScoringParameters {
                        liquidity_penalty_multiplier_msat: 0,
                        liquidity_offset_half_life: Duration::from_secs(3600),
                        amount_penalty_multiplier_msat: 0,
+                       banned_nodes: HashSet::new(),
+               }
+       }
+
+       /// Marks all nodes in the given list as banned, i.e.,
+       /// they will be avoided during path finding.
+       pub fn add_banned_from_list(&mut self, node_ids: Vec<NodeId>) {
+               for id in node_ids {
+                       self.banned_nodes.insert(id);
                }
        }
 }
@@ -472,6 +502,7 @@ impl Default for ProbabilisticScoringParameters {
                        liquidity_penalty_multiplier_msat: 40_000,
                        liquidity_offset_half_life: Duration::from_secs(3600),
                        amount_penalty_multiplier_msat: 256,
+                       banned_nodes: HashSet::new(),
                }
        }
 }
@@ -543,7 +574,7 @@ const AMOUNT_PENALTY_DIVISOR: u64 = 1 << 20;
 impl<L: Deref<Target = u64>, T: Time, U: Deref<Target = T>> DirectedChannelLiquidity<L, T, U> {
        /// Returns a penalty for routing the given HTLC `amount_msat` through the channel in this
        /// direction.
-       fn penalty_msat(&self, amount_msat: u64, params: ProbabilisticScoringParameters) -> u64 {
+       fn penalty_msat(&self, amount_msat: u64, params: &ProbabilisticScoringParameters) -> u64 {
                let max_liquidity_msat = self.max_liquidity_msat();
                let min_liquidity_msat = core::cmp::min(self.min_liquidity_msat(), max_liquidity_msat);
                if amount_msat <= min_liquidity_msat {
@@ -580,7 +611,7 @@ impl<L: Deref<Target = u64>, T: Time, U: Deref<Target = T>> DirectedChannelLiqui
        #[inline(always)]
        fn combined_penalty_msat(
                &self, amount_msat: u64, negative_log10_times_2048: u64,
-               params: ProbabilisticScoringParameters
+               params: &ProbabilisticScoringParameters
        ) -> u64 {
                let liquidity_penalty_msat = {
                        // Upper bound the liquidity penalty to ensure some channel is selected.
@@ -672,6 +703,10 @@ impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, T: Time> Score for Probabilis
        fn channel_penalty_msat(
                &self, short_channel_id: u64, source: &NodeId, target: &NodeId, usage: ChannelUsage
        ) -> u64 {
+               if self.params.banned_nodes.contains(source) || self.params.banned_nodes.contains(target) {
+                       return u64::max_value();
+               }
+
                if let EffectiveCapacity::ExactLiquidity { liquidity_msat } = usage.effective_capacity {
                        if usage.amount_msat > liquidity_msat {
                                return u64::max_value();
@@ -688,7 +723,7 @@ impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, T: Time> Score for Probabilis
                        .get(&short_channel_id)
                        .unwrap_or(&ChannelLiquidity::new())
                        .as_directed(source, target, capacity_msat, liquidity_offset_half_life)
-                       .penalty_msat(amount_msat, self.params)
+                       .penalty_msat(amount_msat, &self.params)
        }
 
        fn payment_path_failed(&mut self, path: &[&RouteHop], short_channel_id: u64) {
@@ -1072,7 +1107,7 @@ impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, T: Time> Writeable for Probab
        #[inline]
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                write_tlv_fields!(w, {
-                       (0, self.channel_liquidities, required)
+                       (0, self.channel_liquidities, required),
                });
                Ok(())
        }
@@ -1087,7 +1122,7 @@ ReadableArgs<(ProbabilisticScoringParameters, G, L)> for ProbabilisticScorerUsin
                let (params, network_graph, logger) = args;
                let mut channel_liquidities = HashMap::new();
                read_tlv_fields!(r, {
-                       (0, channel_liquidities, required)
+                       (0, channel_liquidities, required),
                });
                Ok(Self {
                        params,
@@ -1862,7 +1897,7 @@ mod tests {
                        liquidity_offset_half_life: Duration::from_secs(10),
                        ..ProbabilisticScoringParameters::zero_penalty()
                };
-               let mut scorer = ProbabilisticScorer::new(params, &network_graph, &logger);
+               let mut scorer = ProbabilisticScorer::new(params.clone(), &network_graph, &logger);
                let source = source_node_id();
                let target = target_node_id();
                let usage = ChannelUsage {
@@ -1898,7 +1933,7 @@ mod tests {
                        liquidity_offset_half_life: Duration::from_secs(10),
                        ..ProbabilisticScoringParameters::zero_penalty()
                };
-               let mut scorer = ProbabilisticScorer::new(params, &network_graph, &logger);
+               let mut scorer = ProbabilisticScorer::new(params.clone(), &network_graph, &logger);
                let source = source_node_id();
                let target = target_node_id();
                let usage = ChannelUsage {
@@ -2086,7 +2121,7 @@ mod tests {
                let logger = TestLogger::new();
                let network_graph = network_graph(&logger);
                let params = ProbabilisticScoringParameters::default();
-               let scorer = ProbabilisticScorer::new(params, &network_graph, &logger);
+               let scorer = ProbabilisticScorer::new(params.clone(), &network_graph, &logger);
                let source = source_node_id();
                let target = target_node_id();