Include htlc min/max for ChannelDetails and ChannelCounterparty

fuzz/src/router.rs

@@ -213,6 +213,8 @@ pub fn do_test<Out: test_logger::Output>(data: &[u8], out: Out) {
 									features: InitFeatures::known(),
 									unspendable_punishment_reserve: 0,
 									forwarding_info: None,
+									outbound_htlc_minimum_msat: None,
+									outbound_htlc_maximum_msat: None,
 								},
 								funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
 								channel_type: None,
@@ -227,6 +229,8 @@ pub fn do_test<Out: test_logger::Output>(data: &[u8], out: Out) {
 								is_usable: true, is_public: true,
 								balance_msat: 0,
 								outbound_capacity_msat: 0,
+								inbound_htlc_minimum_msat: None,
+								inbound_htlc_maximum_msat: None,
 							});
 						}
 						Some(&first_hops_vec[..])

lightning-invoice/src/utils.rs

@@ -412,8 +412,8 @@ fn filter_channels(channels: Vec<ChannelDetails>, min_inbound_capacity_msat: Opt
 				proportional_millionths: forwarding_info.fee_proportional_millionths,
 			},
 			cltv_expiry_delta: forwarding_info.cltv_expiry_delta,
-			htlc_minimum_msat: None,
-			htlc_maximum_msat: None,}])
+			htlc_minimum_msat: channel.inbound_htlc_minimum_msat,
+			htlc_maximum_msat: channel.inbound_htlc_maximum_msat,}])
 	};
 	// If all channels are private, return the route hint for the highest inbound capacity channel
 	// per counterparty node. If channels with an higher inbound capacity than the
@@ -535,10 +535,13 @@ mod test {
 
 		// Invoice SCIDs should always use inbound SCID aliases over the real channel ID, if one is
 		// available.
+		let chan = &nodes[1].node.list_usable_channels()[0];
 		assert_eq!(invoice.route_hints().len(), 1);
 		assert_eq!(invoice.route_hints()[0].0.len(), 1);
-		assert_eq!(invoice.route_hints()[0].0[0].short_channel_id,
-			nodes[1].node.list_usable_channels()[0].inbound_scid_alias.unwrap());
+		assert_eq!(invoice.route_hints()[0].0[0].short_channel_id, chan.inbound_scid_alias.unwrap());
+
+		assert_eq!(invoice.route_hints()[0].0[0].htlc_minimum_msat, chan.inbound_htlc_minimum_msat);
+		assert_eq!(invoice.route_hints()[0].0[0].htlc_maximum_msat, chan.inbound_htlc_maximum_msat);
 
 		let payment_params = PaymentParameters::from_node_id(invoice.recover_payee_pub_key())
 			.with_features(invoice.features().unwrap().clone())
@@ -879,6 +882,40 @@ mod test {
 		}
 	}
 
+	#[test]
+	#[cfg(feature = "std")]
+	fn test_multi_node_hints_has_htlc_min_max_values() {
+		let mut chanmon_cfgs = create_chanmon_cfgs(3);
+		let seed_1 = [42 as u8; 32];
+		let seed_2 = [43 as u8; 32];
+		let cross_node_seed = [44 as u8; 32];
+		chanmon_cfgs[1].keys_manager.backing = PhantomKeysManager::new(&seed_1, 43, 44, &cross_node_seed);
+		chanmon_cfgs[2].keys_manager.backing = PhantomKeysManager::new(&seed_2, 43, 44, &cross_node_seed);
+		let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
+		let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
+		let nodes = create_network(3, &node_cfgs, &node_chanmgrs);
+
+		create_unannounced_chan_between_nodes_with_value(&nodes, 0, 1, 100000, 10001, InitFeatures::known(), InitFeatures::known());
+		create_unannounced_chan_between_nodes_with_value(&nodes, 0, 2, 100000, 10001, InitFeatures::known(), InitFeatures::known());
+
+		let payment_amt = 20_000;
+		let (payment_hash, _payment_secret) = nodes[1].node.create_inbound_payment(Some(payment_amt), 3600).unwrap();
+		let route_hints = vec![
+			nodes[1].node.get_phantom_route_hints(),
+			nodes[2].node.get_phantom_route_hints(),
+		];
+
+		let invoice = ::utils::create_phantom_invoice::<EnforcingSigner, &test_utils::TestKeysInterface>(Some(payment_amt), Some(payment_hash), "test".to_string(), 3600, route_hints, &nodes[1].keys_manager, Currency::BitcoinTestnet).unwrap();
+
+		let chan_0_1 = &nodes[1].node.list_usable_channels()[0];
+		assert_eq!(invoice.route_hints()[0].0[0].htlc_minimum_msat, chan_0_1.inbound_htlc_minimum_msat);
+		assert_eq!(invoice.route_hints()[0].0[0].htlc_maximum_msat, chan_0_1.inbound_htlc_maximum_msat);
+
+		let chan_0_2 = &nodes[2].node.list_usable_channels()[0];
+		assert_eq!(invoice.route_hints()[1].0[0].htlc_minimum_msat, chan_0_2.inbound_htlc_minimum_msat);
+		assert_eq!(invoice.route_hints()[1].0[0].htlc_maximum_msat, chan_0_2.inbound_htlc_maximum_msat);
+	}
+
 	#[test]
 	#[cfg(feature = "std")]
 	fn create_phantom_invoice_with_description_hash() {

lightning/src/ln/channel.rs

@@ -4321,11 +4321,15 @@ impl<Signer: Sign> Channel<Signer> {
 	}
 
 	/// Allowed in any state (including after shutdown)
-	#[cfg(test)]
 	pub fn get_holder_htlc_minimum_msat(&self) -> u64 {
 		self.holder_htlc_minimum_msat
 	}
 
+	/// Allowed in any state (including after shutdown), but will return none before TheirInitSent
+	pub fn get_holder_htlc_maximum_msat(&self) -> Option<u64> {
+		self.get_htlc_maximum_msat(self.holder_max_htlc_value_in_flight_msat)
+	}
+
 	/// Allowed in any state (including after shutdown)
 	pub fn get_announced_htlc_max_msat(&self) -> u64 {
 		return cmp::min(
@@ -4343,6 +4347,21 @@ impl<Signer: Sign> Channel<Signer> {
 		self.counterparty_htlc_minimum_msat
 	}
 
+	/// Allowed in any state (including after shutdown), but will return none before TheirInitSent
+	pub fn get_counterparty_htlc_maximum_msat(&self) -> Option<u64> {
+		self.get_htlc_maximum_msat(self.counterparty_max_htlc_value_in_flight_msat)
+	}
+
+	fn get_htlc_maximum_msat(&self, party_max_htlc_value_in_flight_msat: u64) -> Option<u64> {
+		self.counterparty_selected_channel_reserve_satoshis.map(|counterparty_reserve| {
+			let holder_reserve = self.holder_selected_channel_reserve_satoshis;
+			cmp::min(
+				(self.channel_value_satoshis - counterparty_reserve - holder_reserve) * 1000,
+				party_max_htlc_value_in_flight_msat
+			)
+		})
+	}
+
 	pub fn get_value_satoshis(&self) -> u64 {
 		self.channel_value_satoshis
 	}

lightning/src/ln/channelmanager.rs

@@ -922,6 +922,12 @@ pub struct ChannelCounterparty {
 	/// Information on the fees and requirements that the counterparty requires when forwarding
 	/// payments to us through this channel.
 	pub forwarding_info: Option<CounterpartyForwardingInfo>,
+	/// The smallest value HTLC (in msat) the remote peer will accept, for this channel. This field
+	/// is only `None` before we have received either the `OpenChannel` or `AcceptChannel` message
+	/// from the remote peer, or for `ChannelCounterparty` objects serialized prior to LDK 0.0.107.
+	pub outbound_htlc_minimum_msat: Option<u64>,
+	/// The largest value HTLC (in msat) the remote peer currently will accept, for this channel.
+	pub outbound_htlc_maximum_msat: Option<u64>,
 }
 
 /// Details of a channel, as returned by ChannelManager::list_channels and ChannelManager::list_usable_channels
@@ -1046,6 +1052,11 @@ pub struct ChannelDetails {
 	pub is_usable: bool,
 	/// True if this channel is (or will be) publicly-announced.
 	pub is_public: bool,
+	/// The smallest value HTLC (in msat) we will accept, for this channel. This field
+	/// is only `None` for `ChannelDetails` objects serialized prior to LDK 0.0.107
+	pub inbound_htlc_minimum_msat: Option<u64>,
+	/// The largest value HTLC (in msat) we currently will accept, for this channel.
+	pub inbound_htlc_maximum_msat: Option<u64>,
 }
 
 impl ChannelDetails {
@@ -1670,6 +1681,14 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 						features: InitFeatures::empty(),
 						unspendable_punishment_reserve: to_remote_reserve_satoshis,
 						forwarding_info: channel.counterparty_forwarding_info(),
+						// Ensures that we have actually received the `htlc_minimum_msat` value
+						// from the counterparty through the `OpenChannel` or `AcceptChannel`
+						// message (as they are always the first message from the counterparty).
+						// Else `Channel::get_counterparty_htlc_minimum_msat` could return the
+						// default `0` value set by `Channel::new_outbound`.
+						outbound_htlc_minimum_msat: if channel.have_received_message() {
+							Some(channel.get_counterparty_htlc_minimum_msat()) } else { None },
+						outbound_htlc_maximum_msat: channel.get_counterparty_htlc_maximum_msat(),
 					},
 					funding_txo: channel.get_funding_txo(),
 					// Note that accept_channel (or open_channel) is always the first message, so
@@ -1689,6 +1708,8 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 					is_funding_locked: channel.is_usable(),
 					is_usable: channel.is_live(),
 					is_public: channel.should_announce(),
+					inbound_htlc_minimum_msat: Some(channel.get_holder_htlc_minimum_msat()),
+					inbound_htlc_maximum_msat: channel.get_holder_htlc_maximum_msat()
 				});
 			}
 		}
@@ -5897,6 +5918,8 @@ impl_writeable_tlv_based!(ChannelCounterparty, {
 	(4, features, required),
 	(6, unspendable_punishment_reserve, required),
 	(8, forwarding_info, option),
+	(9, outbound_htlc_minimum_msat, option),
+	(11, outbound_htlc_maximum_msat, option),
 });
 
 impl_writeable_tlv_based!(ChannelDetails, {
@@ -5918,6 +5941,8 @@ impl_writeable_tlv_based!(ChannelDetails, {
 	(28, is_funding_locked, required),
 	(30, is_usable, required),
 	(32, is_public, required),
+	(33, inbound_htlc_minimum_msat, option),
+	(35, inbound_htlc_maximum_msat, option),
 });
 
 impl_writeable_tlv_based!(PhantomRouteHints, {

lightning/src/routing/router.rs

@@ -1735,6 +1735,8 @@ mod tests {
 				node_id,
 				unspendable_punishment_reserve: 0,
 				forwarding_info: None,
+				outbound_htlc_minimum_msat: None,
+				outbound_htlc_maximum_msat: None,
 			},
 			funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
 			channel_type: None,
@@ -1750,6 +1752,8 @@ mod tests {
 			force_close_spend_delay: None,
 			is_outbound: true, is_funding_locked: true,
 			is_usable: true, is_public: true,
+			inbound_htlc_minimum_msat: None,
+			inbound_htlc_maximum_msat: None,
 		}
 	}
 
@@ -5456,6 +5460,8 @@ mod benches {
 				node_id,
 				unspendable_punishment_reserve: 0,
 				forwarding_info: None,
+				outbound_htlc_minimum_msat: None,
+				outbound_htlc_maximum_msat: None,
 			},
 			funding_txo: Some(OutPoint {
 				txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0
@@ -5475,6 +5481,8 @@ mod benches {
 			is_funding_locked: true,
 			is_usable: true,
 			is_public: true,
+			inbound_htlc_minimum_msat: None,
+			inbound_htlc_maximum_msat: None,
 		}
 	}