Initialize gossip_query routing table sync on connection

This commit calls sync_routing_table when a peer has connected and
should_request_full_sync is true. The sync flag must be set when the
outbound Init message is sent, we capture whether we want to perform
a sync with a peer in a new field, request_sync, on the Peer struct.
If this flag is set, sync_routing_table is called upon receipt of the
peers Init message.

Author: bmancini55

lightning/src/ln/features.rs

@@ -484,6 +484,7 @@ impl<T: sealed::GossipQueries> Features<T> {
 	pub(crate) fn supports_gossip_queries(&self) -> bool {
 		<T as sealed::GossipQueries>::supports_feature(&self.flags)
 	}
+	#[cfg(test)]
 	pub(crate) fn clear_gossip_queries(mut self) -> Self {
 		<T as sealed::GossipQueries>::clear_bits(&mut self.flags);
 		self

lightning/src/ln/msgs.rs

@@ -825,7 +825,9 @@ pub trait RoutingMessageHandler : Send + Sync + events::MessageSendEventsProvide
 	/// immediately higher (as defined by <PublicKey as Ord>::cmp) than starting_point.
 	/// If None is provided for starting_point, we start at the first node.
 	fn get_next_node_announcements(&self, starting_point: Option<&PublicKey>, batch_amount: u8) -> Vec<NodeAnnouncement>;
-	/// Returns whether a full sync should be requested from a peer.
+	/// Returns whether a full sync should be requested from a peer. The result is
+	/// used to set the initial_routing_sync feature bit when sending an Init message.
+	/// This feature bit is not used by some implementations in favor of using gossip_queries.
 	fn should_request_full_sync(&self, node_id: &PublicKey) -> bool;
 	/// Initiates routing gossip sync by querying a peer to discover channels
 	/// and their associated routing gossip messages. This method will use a

lightning/src/ln/peer_handler.rs

@@ -133,6 +133,7 @@ struct Peer {
 	pending_read_buffer_pos: usize,
 	pending_read_is_header: bool,
 
+	request_sync: bool,
 	sync_status: InitSyncTracker,
 
 	awaiting_pong: bool,
@@ -327,6 +328,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
 			pending_read_buffer_pos: 0,
 			pending_read_is_header: false,
 
+			request_sync: false,
 			sync_status: InitSyncTracker::NoSyncRequested,
 
 			awaiting_pong: false,
@@ -364,6 +366,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
 			pending_read_buffer_pos: 0,
 			pending_read_is_header: false,
 
+			request_sync: false,
 			sync_status: InitSyncTracker::NoSyncRequested,
 
 			awaiting_pong: false,
@@ -584,8 +587,10 @@ 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().clear_gossip_queries();
-									if !self.message_handler.route_handler.should_request_full_sync(&peer.their_node_id.unwrap()) {
+									let mut features = InitFeatures::known();
+									if self.message_handler.route_handler.should_request_full_sync(&peer.their_node_id.unwrap()) {
+										peer.request_sync = true;
+									} else {
 										features.clear_initial_routing_sync();
 									}
 
@@ -713,15 +718,21 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
 				}
 
 				if !peer.outbound {
-					let mut features = InitFeatures::known().clear_gossip_queries();
-					if !self.message_handler.route_handler.should_request_full_sync(&peer.their_node_id.unwrap()) {
+					let mut features = InitFeatures::known();
+					if self.message_handler.route_handler.should_request_full_sync(&peer.their_node_id.unwrap()) {
+						peer.request_sync = true;
+					} else {
 						features.clear_initial_routing_sync();
 					}
 
 					let resp = msgs::Init { features };
 					self.enqueue_message(peers_needing_send, peer, peer_descriptor.clone(), &resp);
 				}
 
+				if peer.request_sync {
+					self.message_handler.route_handler.sync_routing_table(&peer.their_node_id.unwrap(), &msg);
+				}
+
 				self.message_handler.chan_handler.peer_connected(&peer.their_node_id.unwrap(), &msg);
 				peer.their_features = Some(msg.features);
 			},