Relax the channel saturation limit if we can't find enough paths
[rust-lightning] / lightning / src / routing / scoring.rs
index 54400624dce63a30ec0e506bfc1c87800a6bac4a..95ad581105af19a0ef7a927936d5b84d14b2bc62 100644 (file)
@@ -28,7 +28,7 @@
 //! # impl Logger for FakeLogger {
 //! #     fn log(&self, record: &Record) { unimplemented!() }
 //! # }
-//! # fn find_scored_route(payer: PublicKey, route_params: RouteParameters, network_graph: NetworkGraph) {
+//! # fn find_scored_route(payer: PublicKey, route_params: RouteParameters, network_graph: NetworkGraph<&FakeLogger>) {
 //! # let logger = FakeLogger {};
 //! #
 //! // Use the default channel penalties.
@@ -102,6 +102,12 @@ pub trait Score $(: $supertrait)* {
 
        /// Handles updating channel penalties after successfully routing along a path.
        fn payment_path_successful(&mut self, path: &[&RouteHop]);
+
+       /// Handles updating channel penalties after a probe over the given path failed.
+       fn probe_failed(&mut self, path: &[&RouteHop], short_channel_id: u64);
+
+       /// Handles updating channel penalties after a probe over the given path succeeded.
+       fn probe_successful(&mut self, path: &[&RouteHop]);
 }
 
 impl<S: Score, T: DerefMut<Target=S> $(+ $supertrait)*> Score for T {
@@ -118,6 +124,14 @@ impl<S: Score, T: DerefMut<Target=S> $(+ $supertrait)*> Score for T {
        fn payment_path_successful(&mut self, path: &[&RouteHop]) {
                self.deref_mut().payment_path_successful(path)
        }
+
+       fn probe_failed(&mut self, path: &[&RouteHop], short_channel_id: u64) {
+               self.deref_mut().probe_failed(path, short_channel_id)
+       }
+
+       fn probe_successful(&mut self, path: &[&RouteHop]) {
+               self.deref_mut().probe_successful(path)
+       }
 }
 } }
 
@@ -241,6 +255,10 @@ impl Score for FixedPenaltyScorer {
        fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
 
        fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
+
+       fn probe_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
+
+       fn probe_successful(&mut self, _path: &[&RouteHop]) {}
 }
 
 impl Writeable for FixedPenaltyScorer {
@@ -293,7 +311,8 @@ pub type ProbabilisticScorer<G, L> = ProbabilisticScorerUsingTime::<G, L, Config
 /// Probabilistic [`Score`] implementation.
 ///
 /// (C-not exported) generally all users should use the [`ProbabilisticScorer`] type alias.
-pub struct ProbabilisticScorerUsingTime<G: Deref<Target = NetworkGraph>, L: Deref, T: Time> where L::Target: Logger {
+pub struct ProbabilisticScorerUsingTime<G: Deref<Target = NetworkGraph<L>>, L: Deref, T: Time>
+where L::Target: Logger {
        params: ProbabilisticScoringParameters,
        network_graph: G,
        logger: L,
@@ -305,7 +324,7 @@ pub struct ProbabilisticScorerUsingTime<G: Deref<Target = NetworkGraph>, L: Dere
 ///
 /// 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.
        ///
@@ -360,6 +379,19 @@ 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>,
+
+       /// This penalty is applied when `htlc_maximum_msat` is equal to or larger than half of the
+       /// channel's capacity, which makes us prefer nodes with a smaller `htlc_maximum_msat`. We
+       /// treat such nodes preferentially as this makes balance discovery attacks harder to execute,
+       /// thereby creating an incentive to restrict `htlc_maximum_msat` and improve privacy.
+       ///
+       /// Default value: 250 msat
+       pub anti_probing_penalty_msat: u64,
 }
 
 /// Accounting for channel liquidity balance uncertainty.
@@ -389,7 +421,7 @@ struct DirectedChannelLiquidity<L: Deref<Target = u64>, T: Time, U: Deref<Target
        half_life: Duration,
 }
 
-impl<G: Deref<Target = NetworkGraph>, L: Deref, T: Time> ProbabilisticScorerUsingTime<G, L, T> where L::Target: Logger {
+impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, T: Time> ProbabilisticScorerUsingTime<G, L, T> where L::Target: Logger {
        /// Creates a new scorer using the given scoring parameters for sending payments from a node
        /// through a network graph.
        pub fn new(params: ProbabilisticScoringParameters, network_graph: G, logger: L) -> Self {
@@ -433,6 +465,39 @@ impl<G: Deref<Target = NetworkGraph>, L: Deref, T: Time> ProbabilisticScorerUsin
                        }
                }
        }
+
+       /// Query the estimated minimum and maximum liquidity available for sending a payment over the
+       /// channel with `scid` towards the given `target` node.
+       pub fn estimated_channel_liquidity_range(&self, scid: u64, target: &NodeId) -> Option<(u64, u64)> {
+               let graph = self.network_graph.read_only();
+
+               if let Some(chan) = graph.channels().get(&scid) {
+                       if let Some(liq) = self.channel_liquidities.get(&scid) {
+                               if let Some((directed_info, source)) = chan.as_directed_to(target) {
+                                       let amt = directed_info.effective_capacity().as_msat();
+                                       let dir_liq = liq.as_directed(source, target, amt, self.params.liquidity_offset_half_life);
+                                       return Some((dir_liq.min_liquidity_msat(), dir_liq.max_liquidity_msat()));
+                               }
+                       }
+               }
+               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 {
@@ -443,6 +508,16 @@ impl ProbabilisticScoringParameters {
                        liquidity_penalty_multiplier_msat: 0,
                        liquidity_offset_half_life: Duration::from_secs(3600),
                        amount_penalty_multiplier_msat: 0,
+                       banned_nodes: HashSet::new(),
+                       anti_probing_penalty_msat: 0,
+               }
+       }
+
+       /// 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);
                }
        }
 }
@@ -454,6 +529,8 @@ 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(),
+                       anti_probing_penalty_msat: 250,
                }
        }
 }
@@ -525,7 +602,7 @@ 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 {
@@ -562,7 +639,7 @@ 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.
@@ -650,16 +727,29 @@ impl<L: DerefMut<Target = u64>, T: Time, U: DerefMut<Target = T>> DirectedChanne
        }
 }
 
-impl<G: Deref<Target = NetworkGraph>, L: Deref, T: Time> Score for ProbabilisticScorerUsingTime<G, L, T> where L::Target: Logger {
+impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, T: Time> Score for ProbabilisticScorerUsingTime<G, L, T> where L::Target: Logger {
        fn channel_penalty_msat(
                &self, short_channel_id: u64, source: &NodeId, target: &NodeId, usage: ChannelUsage
        ) -> u64 {
-               if let EffectiveCapacity::ExactLiquidity { liquidity_msat } = usage.effective_capacity {
-                       if usage.amount_msat > liquidity_msat {
-                               return u64::max_value();
-                       } else {
-                               return self.params.base_penalty_msat;
-                       };
+               if self.params.banned_nodes.contains(source) || self.params.banned_nodes.contains(target) {
+                       return u64::max_value();
+               }
+
+               let mut anti_probing_penalty_msat = 0;
+               match usage.effective_capacity {
+                       EffectiveCapacity::ExactLiquidity { liquidity_msat } => {
+                               if usage.amount_msat > liquidity_msat {
+                                       return u64::max_value();
+                               } else {
+                                       return self.params.base_penalty_msat;
+                               }
+                       },
+                       EffectiveCapacity::Total { capacity_msat, htlc_maximum_msat: Some(htlc_maximum_msat) } => {
+                               if htlc_maximum_msat >= capacity_msat/2 {
+                                       anti_probing_penalty_msat = self.params.anti_probing_penalty_msat;
+                               }
+                       },
+                       _ => {},
                }
 
                let liquidity_offset_half_life = self.params.liquidity_offset_half_life;
@@ -670,7 +760,8 @@ impl<G: Deref<Target = NetworkGraph>, L: Deref, T: Time> Score for Probabilistic
                        .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)
+                       .saturating_add(anti_probing_penalty_msat)
        }
 
        fn payment_path_failed(&mut self, path: &[&RouteHop], short_channel_id: u64) {
@@ -738,6 +829,14 @@ impl<G: Deref<Target = NetworkGraph>, L: Deref, T: Time> Score for Probabilistic
                        }
                }
        }
+
+       fn probe_failed(&mut self, path: &[&RouteHop], short_channel_id: u64) {
+               self.payment_path_failed(path, short_channel_id)
+       }
+
+       fn probe_successful(&mut self, path: &[&RouteHop]) {
+               self.payment_path_failed(path, u64::max_value())
+       }
 }
 
 mod approx {
@@ -1050,17 +1149,17 @@ mod approx {
        }
 }
 
-impl<G: Deref<Target = NetworkGraph>, L: Deref, T: Time> Writeable for ProbabilisticScorerUsingTime<G, L, T> where L::Target: Logger {
+impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, T: Time> Writeable for ProbabilisticScorerUsingTime<G, L, T> where L::Target: Logger {
        #[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(())
        }
 }
 
-impl<G: Deref<Target = NetworkGraph>, L: Deref, T: Time>
+impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, T: Time>
 ReadableArgs<(ProbabilisticScoringParameters, G, L)> for ProbabilisticScorerUsingTime<G, L, T> where L::Target: Logger {
        #[inline]
        fn read<R: Read>(
@@ -1069,7 +1168,7 @@ 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,
@@ -1163,7 +1262,7 @@ mod tests {
        // `ProbabilisticScorer` tests
 
        /// A probabilistic scorer for testing with time that can be manually advanced.
-       type ProbabilisticScorer<'a> = ProbabilisticScorerUsingTime::<&'a NetworkGraph, &'a TestLogger, SinceEpoch>;
+       type ProbabilisticScorer<'a> = ProbabilisticScorerUsingTime::<&'a NetworkGraph<&'a TestLogger>, &'a TestLogger, SinceEpoch>;
 
        fn sender_privkey() -> SecretKey {
                SecretKey::from_slice(&[41; 32]).unwrap()
@@ -1191,9 +1290,9 @@ mod tests {
                NodeId::from_pubkey(&recipient_pubkey())
        }
 
-       fn network_graph() -> NetworkGraph {
+       fn network_graph(logger: &TestLogger) -> NetworkGraph<&TestLogger> {
                let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
-               let mut network_graph = NetworkGraph::new(genesis_hash);
+               let mut network_graph = NetworkGraph::new(genesis_hash, logger);
                add_channel(&mut network_graph, 42, source_privkey(), target_privkey());
                add_channel(&mut network_graph, 43, target_privkey(), recipient_privkey());
 
@@ -1201,7 +1300,7 @@ mod tests {
        }
 
        fn add_channel(
-               network_graph: &mut NetworkGraph, short_channel_id: u64, node_1_key: SecretKey,
+               network_graph: &mut NetworkGraph<&TestLogger>, short_channel_id: u64, node_1_key: SecretKey,
                node_2_key: SecretKey
        ) {
                let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
@@ -1228,13 +1327,14 @@ mod tests {
                };
                let chain_source: Option<&::util::test_utils::TestChainSource> = None;
                network_graph.update_channel_from_announcement(
-                       &signed_announcement, &chain_source, &secp_ctx).unwrap();
+                       &signed_announcement, &chain_source).unwrap();
                update_channel(network_graph, short_channel_id, node_1_key, 0);
                update_channel(network_graph, short_channel_id, node_2_key, 1);
        }
 
        fn update_channel(
-               network_graph: &mut NetworkGraph, short_channel_id: u64, node_key: SecretKey, flags: u8
+               network_graph: &mut NetworkGraph<&TestLogger>, short_channel_id: u64, node_key: SecretKey,
+               flags: u8
        ) {
                let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
                let secp_ctx = Secp256k1::new();
@@ -1255,7 +1355,7 @@ mod tests {
                        signature: secp_ctx.sign_ecdsa(&msghash, &node_key),
                        contents: unsigned_update,
                };
-               network_graph.update_channel(&signed_update, &secp_ctx).unwrap();
+               network_graph.update_channel(&signed_update).unwrap();
        }
 
        fn payment_path_for_amount(amount_msat: u64) -> Vec<RouteHop> {
@@ -1291,7 +1391,7 @@ mod tests {
        fn liquidity_bounds_directed_from_lowest_node_id() {
                let logger = TestLogger::new();
                let last_updated = SinceEpoch::now();
-               let network_graph = network_graph();
+               let network_graph = network_graph(&logger);
                let params = ProbabilisticScoringParameters::default();
                let mut scorer = ProbabilisticScorer::new(params, &network_graph, &logger)
                        .with_channel(42,
@@ -1366,7 +1466,7 @@ mod tests {
        fn resets_liquidity_upper_bound_when_crossed_by_lower_bound() {
                let logger = TestLogger::new();
                let last_updated = SinceEpoch::now();
-               let network_graph = network_graph();
+               let network_graph = network_graph(&logger);
                let params = ProbabilisticScoringParameters::default();
                let mut scorer = ProbabilisticScorer::new(params, &network_graph, &logger)
                        .with_channel(42,
@@ -1424,7 +1524,7 @@ mod tests {
        fn resets_liquidity_lower_bound_when_crossed_by_upper_bound() {
                let logger = TestLogger::new();
                let last_updated = SinceEpoch::now();
-               let network_graph = network_graph();
+               let network_graph = network_graph(&logger);
                let params = ProbabilisticScoringParameters::default();
                let mut scorer = ProbabilisticScorer::new(params, &network_graph, &logger)
                        .with_channel(42,
@@ -1481,7 +1581,7 @@ mod tests {
        #[test]
        fn increased_penalty_nearing_liquidity_upper_bound() {
                let logger = TestLogger::new();
-               let network_graph = network_graph();
+               let network_graph = network_graph(&logger);
                let params = ProbabilisticScoringParameters {
                        liquidity_penalty_multiplier_msat: 1_000,
                        ..ProbabilisticScoringParameters::zero_penalty()
@@ -1493,7 +1593,7 @@ mod tests {
                let usage = ChannelUsage {
                        amount_msat: 1_024,
                        inflight_htlc_msat: 0,
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024_000 },
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024_000, htlc_maximum_msat: Some(1_000) },
                };
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 0);
                let usage = ChannelUsage { amount_msat: 10_240, ..usage };
@@ -1506,7 +1606,7 @@ mod tests {
                let usage = ChannelUsage {
                        amount_msat: 128,
                        inflight_htlc_msat: 0,
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024 },
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024, htlc_maximum_msat: Some(1_000) },
                };
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 58);
                let usage = ChannelUsage { amount_msat: 256, ..usage };
@@ -1527,7 +1627,7 @@ mod tests {
        fn constant_penalty_outside_liquidity_bounds() {
                let logger = TestLogger::new();
                let last_updated = SinceEpoch::now();
-               let network_graph = network_graph();
+               let network_graph = network_graph(&logger);
                let params = ProbabilisticScoringParameters {
                        liquidity_penalty_multiplier_msat: 1_000,
                        ..ProbabilisticScoringParameters::zero_penalty()
@@ -1543,7 +1643,7 @@ mod tests {
                let usage = ChannelUsage {
                        amount_msat: 39,
                        inflight_htlc_msat: 0,
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 100 },
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 100, htlc_maximum_msat: Some(1_000) },
                };
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 0);
                let usage = ChannelUsage { amount_msat: 50, ..usage };
@@ -1556,7 +1656,7 @@ mod tests {
        #[test]
        fn does_not_further_penalize_own_channel() {
                let logger = TestLogger::new();
-               let network_graph = network_graph();
+               let network_graph = network_graph(&logger);
                let params = ProbabilisticScoringParameters {
                        liquidity_penalty_multiplier_msat: 1_000,
                        ..ProbabilisticScoringParameters::zero_penalty()
@@ -1567,7 +1667,7 @@ mod tests {
                let usage = ChannelUsage {
                        amount_msat: 500,
                        inflight_htlc_msat: 0,
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_000 },
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_000, htlc_maximum_msat: Some(1_000) },
                };
                let failed_path = payment_path_for_amount(500);
                let successful_path = payment_path_for_amount(200);
@@ -1584,7 +1684,7 @@ mod tests {
        #[test]
        fn sets_liquidity_lower_bound_on_downstream_failure() {
                let logger = TestLogger::new();
-               let network_graph = network_graph();
+               let network_graph = network_graph(&logger);
                let params = ProbabilisticScoringParameters {
                        liquidity_penalty_multiplier_msat: 1_000,
                        ..ProbabilisticScoringParameters::zero_penalty()
@@ -1597,7 +1697,7 @@ mod tests {
                let usage = ChannelUsage {
                        amount_msat: 250,
                        inflight_htlc_msat: 0,
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_000 },
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_000, htlc_maximum_msat: Some(1_000) },
                };
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 128);
                let usage = ChannelUsage { amount_msat: 500, ..usage };
@@ -1618,7 +1718,7 @@ mod tests {
        #[test]
        fn sets_liquidity_upper_bound_on_failure() {
                let logger = TestLogger::new();
-               let network_graph = network_graph();
+               let network_graph = network_graph(&logger);
                let params = ProbabilisticScoringParameters {
                        liquidity_penalty_multiplier_msat: 1_000,
                        ..ProbabilisticScoringParameters::zero_penalty()
@@ -1631,7 +1731,7 @@ mod tests {
                let usage = ChannelUsage {
                        amount_msat: 250,
                        inflight_htlc_msat: 0,
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_000 },
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_000, htlc_maximum_msat: Some(1_000) },
                };
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 128);
                let usage = ChannelUsage { amount_msat: 500, ..usage };
@@ -1652,7 +1752,7 @@ mod tests {
        #[test]
        fn reduces_liquidity_upper_bound_along_path_on_success() {
                let logger = TestLogger::new();
-               let network_graph = network_graph();
+               let network_graph = network_graph(&logger);
                let params = ProbabilisticScoringParameters {
                        liquidity_penalty_multiplier_msat: 1_000,
                        ..ProbabilisticScoringParameters::zero_penalty()
@@ -1665,7 +1765,7 @@ mod tests {
                let usage = ChannelUsage {
                        amount_msat: 250,
                        inflight_htlc_msat: 0,
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_000 },
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_000, htlc_maximum_msat: Some(1_000) },
                };
                let path = payment_path_for_amount(500);
 
@@ -1683,7 +1783,7 @@ mod tests {
        #[test]
        fn decays_liquidity_bounds_over_time() {
                let logger = TestLogger::new();
-               let network_graph = network_graph();
+               let network_graph = network_graph(&logger);
                let params = ProbabilisticScoringParameters {
                        liquidity_penalty_multiplier_msat: 1_000,
                        liquidity_offset_half_life: Duration::from_secs(10),
@@ -1696,7 +1796,7 @@ mod tests {
                let usage = ChannelUsage {
                        amount_msat: 0,
                        inflight_htlc_msat: 0,
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024 },
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024, htlc_maximum_msat: Some(1_000) },
                };
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 0);
                let usage = ChannelUsage { amount_msat: 1_024, ..usage };
@@ -1762,7 +1862,7 @@ mod tests {
        #[test]
        fn decays_liquidity_bounds_without_shift_overflow() {
                let logger = TestLogger::new();
-               let network_graph = network_graph();
+               let network_graph = network_graph(&logger);
                let params = ProbabilisticScoringParameters {
                        liquidity_penalty_multiplier_msat: 1_000,
                        liquidity_offset_half_life: Duration::from_secs(10),
@@ -1774,7 +1874,7 @@ mod tests {
                let usage = ChannelUsage {
                        amount_msat: 256,
                        inflight_htlc_msat: 0,
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024 },
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024, htlc_maximum_msat: Some(1_000) },
                };
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 125);
 
@@ -1793,7 +1893,7 @@ mod tests {
        #[test]
        fn restricts_liquidity_bounds_after_decay() {
                let logger = TestLogger::new();
-               let network_graph = network_graph();
+               let network_graph = network_graph(&logger);
                let params = ProbabilisticScoringParameters {
                        liquidity_penalty_multiplier_msat: 1_000,
                        liquidity_offset_half_life: Duration::from_secs(10),
@@ -1805,7 +1905,7 @@ mod tests {
                let usage = ChannelUsage {
                        amount_msat: 512,
                        inflight_htlc_msat: 0,
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024 },
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024, htlc_maximum_msat: Some(1_000) },
                };
 
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 300);
@@ -1837,19 +1937,19 @@ mod tests {
        #[test]
        fn restores_persisted_liquidity_bounds() {
                let logger = TestLogger::new();
-               let network_graph = network_graph();
+               let network_graph = network_graph(&logger);
                let params = ProbabilisticScoringParameters {
                        liquidity_penalty_multiplier_msat: 1_000,
                        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 {
                        amount_msat: 500,
                        inflight_htlc_msat: 0,
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_000 },
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_000, htlc_maximum_msat: Some(1_000) },
                };
 
                scorer.payment_path_failed(&payment_path_for_amount(500).iter().collect::<Vec<_>>(), 42);
@@ -1873,19 +1973,19 @@ mod tests {
        #[test]
        fn decays_persisted_liquidity_bounds() {
                let logger = TestLogger::new();
-               let network_graph = network_graph();
+               let network_graph = network_graph(&logger);
                let params = ProbabilisticScoringParameters {
                        liquidity_penalty_multiplier_msat: 1_000,
                        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 {
                        amount_msat: 500,
                        inflight_htlc_msat: 0,
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_000 },
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_000, htlc_maximum_msat: Some(1_000) },
                };
 
                scorer.payment_path_failed(&payment_path_for_amount(500).iter().collect::<Vec<_>>(), 42);
@@ -1913,7 +2013,7 @@ mod tests {
                // Shows the scores of "realistic" sends of 100k sats over channels of 1-10m sats (with a
                // 50k sat reserve).
                let logger = TestLogger::new();
-               let network_graph = network_graph();
+               let network_graph = network_graph(&logger);
                let params = ProbabilisticScoringParameters::default();
                let scorer = ProbabilisticScorer::new(params, &network_graph, &logger);
                let source = source_node_id();
@@ -1922,47 +2022,47 @@ mod tests {
                let usage = ChannelUsage {
                        amount_msat: 100_000_000,
                        inflight_htlc_msat: 0,
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 950_000_000 },
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 950_000_000, htlc_maximum_msat: Some(1_000) },
                };
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 3613);
                let usage = ChannelUsage {
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_950_000_000 }, ..usage
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_950_000_000, htlc_maximum_msat: Some(1_000) }, ..usage
                };
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1977);
                let usage = ChannelUsage {
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 2_950_000_000 }, ..usage
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 2_950_000_000, htlc_maximum_msat: Some(1_000) }, ..usage
                };
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1474);
                let usage = ChannelUsage {
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 3_950_000_000 }, ..usage
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 3_950_000_000, htlc_maximum_msat: Some(1_000) }, ..usage
                };
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1223);
                let usage = ChannelUsage {
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 4_950_000_000 }, ..usage
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 4_950_000_000, htlc_maximum_msat: Some(1_000) }, ..usage
                };
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 877);
                let usage = ChannelUsage {
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 5_950_000_000 }, ..usage
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 5_950_000_000, htlc_maximum_msat: Some(1_000) }, ..usage
                };
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 845);
                let usage = ChannelUsage {
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 6_950_000_000 }, ..usage
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 6_950_000_000, htlc_maximum_msat: Some(1_000) }, ..usage
                };
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 500);
                let usage = ChannelUsage {
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 7_450_000_000 }, ..usage
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 7_450_000_000, htlc_maximum_msat: Some(1_000) }, ..usage
                };
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 500);
                let usage = ChannelUsage {
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 7_950_000_000 }, ..usage
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 7_950_000_000, htlc_maximum_msat: Some(1_000) }, ..usage
                };
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 500);
                let usage = ChannelUsage {
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 8_950_000_000 }, ..usage
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 8_950_000_000, htlc_maximum_msat: Some(1_000) }, ..usage
                };
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 500);
                let usage = ChannelUsage {
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 9_950_000_000 }, ..usage
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 9_950_000_000, htlc_maximum_msat: Some(1_000) }, ..usage
                };
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 500);
        }
@@ -1970,13 +2070,13 @@ mod tests {
        #[test]
        fn adds_base_penalty_to_liquidity_penalty() {
                let logger = TestLogger::new();
-               let network_graph = network_graph();
+               let network_graph = network_graph(&logger);
                let source = source_node_id();
                let target = target_node_id();
                let usage = ChannelUsage {
                        amount_msat: 128,
                        inflight_htlc_msat: 0,
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024 },
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024, htlc_maximum_msat: Some(1_000) },
                };
 
                let params = ProbabilisticScoringParameters {
@@ -1987,7 +2087,8 @@ mod tests {
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 58);
 
                let params = ProbabilisticScoringParameters {
-                       base_penalty_msat: 500, liquidity_penalty_multiplier_msat: 1_000, ..Default::default()
+                       base_penalty_msat: 500, liquidity_penalty_multiplier_msat: 1_000,
+                       anti_probing_penalty_msat: 0, ..Default::default()
                };
                let scorer = ProbabilisticScorer::new(params, &network_graph, &logger);
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 558);
@@ -1996,13 +2097,13 @@ mod tests {
        #[test]
        fn adds_amount_penalty_to_liquidity_penalty() {
                let logger = TestLogger::new();
-               let network_graph = network_graph();
+               let network_graph = network_graph(&logger);
                let source = source_node_id();
                let target = target_node_id();
                let usage = ChannelUsage {
                        amount_msat: 512_000,
                        inflight_htlc_msat: 0,
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024_000 },
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024_000, htlc_maximum_msat: Some(1_000) },
                };
 
                let params = ProbabilisticScoringParameters {
@@ -2025,7 +2126,7 @@ mod tests {
        #[test]
        fn calculates_log10_without_overflowing_u64_max_value() {
                let logger = TestLogger::new();
-               let network_graph = network_graph();
+               let network_graph = network_graph(&logger);
                let source = source_node_id();
                let target = target_node_id();
                let usage = ChannelUsage {
@@ -2044,8 +2145,8 @@ mod tests {
 
        #[test]
        fn accounts_for_inflight_htlc_usage() {
-               let network_graph = network_graph();
                let logger = TestLogger::new();
+               let network_graph = network_graph(&logger);
                let params = ProbabilisticScoringParameters::default();
                let scorer = ProbabilisticScorer::new(params, &network_graph, &logger);
                let source = source_node_id();
@@ -2054,7 +2155,7 @@ mod tests {
                let usage = ChannelUsage {
                        amount_msat: 750,
                        inflight_htlc_msat: 0,
-                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_000 },
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_000, htlc_maximum_msat: Some(1_000) },
                };
                assert_ne!(scorer.channel_penalty_msat(42, &source, &target, usage), u64::max_value());
 
@@ -2064,10 +2165,10 @@ mod tests {
 
        #[test]
        fn removes_uncertainity_when_exact_liquidity_known() {
-               let network_graph = network_graph();
                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();
 
@@ -2085,4 +2186,49 @@ mod tests {
                let usage = ChannelUsage { amount_msat: 1_001, ..usage };
                assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), u64::max_value());
        }
+
+       #[test]
+       fn adds_anti_probing_penalty() {
+               let logger = TestLogger::new();
+               let network_graph = network_graph(&logger);
+               let source = source_node_id();
+               let target = target_node_id();
+               let params = ProbabilisticScoringParameters {
+                       anti_probing_penalty_msat: 500,
+                       ..ProbabilisticScoringParameters::zero_penalty()
+               };
+               let scorer = ProbabilisticScorer::new(params, &network_graph, &logger);
+
+               // Check we receive no penalty for a low htlc_maximum_msat.
+               let usage = ChannelUsage {
+                       amount_msat: 512_000,
+                       inflight_htlc_msat: 0,
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024_000, htlc_maximum_msat: Some(1_000) },
+               };
+               assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 0);
+
+               // Check we receive anti-probing penalty for htlc_maximum_msat == channel_capacity.
+               let usage = ChannelUsage {
+                       amount_msat: 512_000,
+                       inflight_htlc_msat: 0,
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024_000, htlc_maximum_msat: Some(1_024_000) },
+               };
+               assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 500);
+
+               // Check we receive anti-probing penalty for htlc_maximum_msat == channel_capacity/2.
+               let usage = ChannelUsage {
+                       amount_msat: 512_000,
+                       inflight_htlc_msat: 0,
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024_000, htlc_maximum_msat: Some(512_000) },
+               };
+               assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 500);
+
+               // Check we receive no anti-probing penalty for htlc_maximum_msat == channel_capacity/2 - 1.
+               let usage = ChannelUsage {
+                       amount_msat: 512_000,
+                       inflight_htlc_msat: 0,
+                       effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024_000, htlc_maximum_msat: Some(511_999) },
+               };
+               assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 0);
+       }
 }