Add gossip_queries feature flag

Support for the gossip_queries feature flag (bits 6/7) is added to the
Features struct. This feature is available in the Init and Node
contexts. The gossip_queries feature is not fully implemented so this
feature is disabled when sent to peers in the Init message.

Author: bmancini55

lightning/src/ln/features.rs

@@ -104,7 +104,7 @@ mod sealed {
 		],
 		optional_features: [
 			// Byte 0
-			DataLossProtect | InitialRoutingSync | UpfrontShutdownScript,
+			DataLossProtect | InitialRoutingSync | UpfrontShutdownScript | GossipQueries,
 			// Byte 1
 			VariableLengthOnion | PaymentSecret,
 			// Byte 2
@@ -122,7 +122,7 @@ mod sealed {
 		],
 		optional_features: [
 			// Byte 0
-			DataLossProtect | UpfrontShutdownScript,
+			DataLossProtect | UpfrontShutdownScript | GossipQueries,
 			// Byte 1
 			VariableLengthOnion | PaymentSecret,
 			// Byte 2
@@ -243,6 +243,8 @@ mod sealed {
 		"Feature flags for `initial_routing_sync`.");
 	define_feature!(5, UpfrontShutdownScript, [InitContext, NodeContext],
 		"Feature flags for `option_upfront_shutdown_script`.");
+	define_feature!(7, GossipQueries, [InitContext, NodeContext],
+		"Feature flags for `gossip_queries`.");
 	define_feature!(9, VariableLengthOnion, [InitContext, NodeContext],
 		"Feature flags for `var_onion_optin`.");
 	define_feature!(13, StaticRemoteKey, [InitContext, NodeContext],
@@ -473,6 +475,21 @@ impl<T: sealed::UpfrontShutdownScript> Features<T> {
 	}
 }
 
+
+impl<T: sealed::GossipQueries> Features<T> {
+	#[cfg(test)]
+	pub(crate) fn requires_gossip_queries(&self) -> bool {
+		<T as sealed::GossipQueries>::requires_feature(&self.flags)
+	}
+	pub(crate) fn supports_gossip_queries(&self) -> bool {
+		<T as sealed::GossipQueries>::supports_feature(&self.flags)
+	}
+	pub(crate) fn clear_gossip_queries(mut self) -> Self {
+		<T as sealed::GossipQueries>::clear_bits(&mut self.flags);
+		self
+	}
+}
+
 impl<T: sealed::VariableLengthOnion> Features<T> {
 	#[cfg(test)]
 	pub(crate) fn requires_variable_length_onion(&self) -> bool {
@@ -568,6 +585,11 @@ mod tests {
 		assert!(!InitFeatures::known().requires_upfront_shutdown_script());
 		assert!(!NodeFeatures::known().requires_upfront_shutdown_script());
 
+		assert!(InitFeatures::known().supports_gossip_queries());
+		assert!(NodeFeatures::known().supports_gossip_queries());
+		assert!(!InitFeatures::known().requires_gossip_queries());
+		assert!(!NodeFeatures::known().requires_gossip_queries());
+
 		assert!(InitFeatures::known().supports_data_loss_protect());
 		assert!(NodeFeatures::known().supports_data_loss_protect());
 		assert!(!InitFeatures::known().requires_data_loss_protect());
@@ -620,9 +642,10 @@ mod tests {
 
 	#[test]
 	fn convert_to_context_with_relevant_flags() {
-		let init_features = InitFeatures::known().clear_upfront_shutdown_script();
+		let init_features = InitFeatures::known().clear_upfront_shutdown_script().clear_gossip_queries();
 		assert!(init_features.initial_routing_sync());
 		assert!(!init_features.supports_upfront_shutdown_script());
+		assert!(!init_features.supports_gossip_queries());
 
 		let node_features: NodeFeatures = init_features.to_context();
 		{
@@ -639,8 +662,10 @@ mod tests {
 		// Check that cleared flags are kept blank when converting back:
 		// - initial_routing_sync was not applicable to NodeContext
 		// - upfront_shutdown_script was cleared before converting
+		// - gossip_queries was cleared before converting
 		let features: InitFeatures = node_features.to_context_internal();
 		assert!(!features.initial_routing_sync());
 		assert!(!features.supports_upfront_shutdown_script());
+		assert!(!init_features.supports_gossip_queries());
 	}
 }

lightning/src/ln/peer_handler.rs

@@ -584,7 +584,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
 
 									peer.their_node_id = Some(their_node_id);
 									insert_node_id!();
-									let mut features = InitFeatures::known();
+									let mut features = InitFeatures::known().clear_gossip_queries();
 									if !self.message_handler.route_handler.should_request_full_sync(&peer.their_node_id.unwrap()) {
 										features.clear_initial_routing_sync();
 									}
@@ -694,10 +694,11 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
 				}
 
 				log_info!(
-					self.logger, "Received peer Init message: data_loss_protect: {}, initial_routing_sync: {}, upfront_shutdown_script: {}, static_remote_key: {}, unknown flags (local and global): {}",
+					self.logger, "Received peer Init message: data_loss_protect: {}, initial_routing_sync: {}, upfront_shutdown_script: {}, gossip_queries: {}, static_remote_key: {}, unknown flags (local and global): {}",
 					if msg.features.supports_data_loss_protect() { "supported" } else { "not supported"},
 					if msg.features.initial_routing_sync() { "requested" } else { "not requested" },
 					if msg.features.supports_upfront_shutdown_script() { "supported" } else { "not supported"},
+					if msg.features.supports_gossip_queries() { "supported" } else { "not supported" },
 					if msg.features.supports_static_remote_key() { "supported" } else { "not supported"},
 					if msg.features.supports_unknown_bits() { "present" } else { "none" }
 				);
@@ -712,7 +713,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
 				}
 
 				if !peer.outbound {
-					let mut features = InitFeatures::known();
+					let mut features = InitFeatures::known().clear_gossip_queries();
 					if !self.message_handler.route_handler.should_request_full_sync(&peer.their_node_id.unwrap()) {
 						features.clear_initial_routing_sync();
 					}

lightning/src/ln/wire.rs

@@ -415,24 +415,25 @@ mod tests {
 	fn read_lnd_init_msg() {
 		// Taken from lnd v0.9.0-beta.
 		let buffer = vec![0, 16, 0, 2, 34, 0, 0, 3, 2, 162, 161];
-		check_init_msg(buffer);
+		check_init_msg(buffer, false);
 	}
 
 	#[test]
 	fn read_clightning_init_msg() {
 		// Taken from c-lightning v0.8.0.
 		let buffer = vec![0, 16, 0, 2, 34, 0, 0, 3, 2, 170, 162, 1, 32, 6, 34, 110, 70, 17, 26, 11, 89, 202, 175, 18, 96, 67, 235, 91, 191, 40, 195, 79, 58, 94, 51, 42, 31, 199, 178, 183, 60, 241, 136, 145, 15];
-		check_init_msg(buffer);
+		check_init_msg(buffer, true);
 	}
 
-	fn check_init_msg(buffer: Vec<u8>) {
+	fn check_init_msg(buffer: Vec<u8>, expect_unknown: bool) {
 		let mut reader = ::std::io::Cursor::new(buffer);
 		let decoded_msg = read(&mut reader).unwrap();
 		match decoded_msg {
 			Message::Init(msgs::Init { features }) => {
 				assert!(features.supports_variable_length_onion());
 				assert!(features.supports_upfront_shutdown_script());
-				assert!(features.supports_unknown_bits());
+				assert!(features.supports_gossip_queries());
+				assert_eq!(expect_unknown, features.supports_unknown_bits());
 				assert!(!features.requires_unknown_bits());
 				assert!(!features.initial_routing_sync());
 			},
@@ -450,7 +451,7 @@ mod tests {
 			Message::NodeAnnouncement(msgs::NodeAnnouncement { contents: msgs::UnsignedNodeAnnouncement { features, ..}, ..}) => {
 				assert!(features.supports_variable_length_onion());
 				assert!(features.supports_upfront_shutdown_script());
-				assert!(features.supports_unknown_bits());
+				assert!(features.supports_gossip_queries());
 				assert!(!features.requires_unknown_bits());
 			},
 			_ => panic!("Expected node announcement, found message type: {}", decoded_msg.type_id())