Test anti-probing penalty.

Author: tnull

lightning/src/routing/gossip.rs

@@ -128,6 +128,9 @@ pub struct NetworkGraph<L: Deref> where L::Target: Logger {
 	genesis_hash: BlockHash,
 	logger: L,
 	// Lock order: channels -> nodes
+	#[cfg(test)]
+	pub(crate) channels: RwLock<BTreeMap<u64, ChannelInfo>>,
+	#[cfg(not(test))]
 	channels: RwLock<BTreeMap<u64, ChannelInfo>>,
 	nodes: RwLock<BTreeMap<NodeId, NodeInfo>>,
 }

lightning/src/routing/scoring.rs

@@ -2133,4 +2133,56 @@ 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 usage = ChannelUsage {
+			amount_msat: 512_000,
+			inflight_htlc_msat: 0,
+			effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024_000 },
+		};
+
+		if let Some(chan) = network_graph.channels.write().unwrap().get_mut(&42) {
+			chan.capacity_sats = Some(1_024);
+		}
+
+		let params = ProbabilisticScoringParameters {
+			anti_probing_penalty_multiplier_msat: 10_000,
+			..ProbabilisticScoringParameters::zero_penalty()
+		};
+		let scorer = ProbabilisticScorer::new(params, &network_graph, &logger);
+
+		// Check we receive a negligible penalty for a low htlc_maximum_msat.
+		assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 34);
+
+		// Now update the htlc_maximum_msat
+		let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
+		let secp_ctx = Secp256k1::new();
+		let unsigned_update = UnsignedChannelUpdate {
+			chain_hash: genesis_hash,
+			short_channel_id: 42,
+			timestamp: 101,
+			flags: 0,
+			cltv_expiry_delta: 18,
+			htlc_minimum_msat: 0,
+			htlc_maximum_msat: OptionalField::Present(1_024_000),
+			fee_base_msat: 1,
+			fee_proportional_millionths: 0,
+			excess_data: Vec::new(),
+		};
+		let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_update.encode()[..])[..]);
+		let signed_update = ChannelUpdate {
+			signature: secp_ctx.sign_ecdsa(&msghash, &source_privkey()),
+			contents: unsigned_update,
+		};
+		network_graph.update_channel(&signed_update).unwrap();
+
+		// Check we receive a sensible penalty for htlc_maximum_msat == channel_capacity.
+		// -log(1/1_024_000) * 10_000 = 60_102
+		assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 60_102);
+	}
 }