Send a gossip_timestamp_filter on connect to enable gossip sync

lightning/src/ln/channelmanager.rs

@@ -5893,6 +5893,7 @@ impl<Signer: Sign, M: Deref , T: Deref , K: Deref , F: Deref , L: Deref >
 					&events::MessageSendEvent::SendChannelRangeQuery { .. } => false,
 					&events::MessageSendEvent::SendShortIdsQuery { .. } => false,
 					&events::MessageSendEvent::SendReplyChannelRange { .. } => false,
+					&events::MessageSendEvent::SendGossipTimestampFilter { .. } => false,
 				}
 			});
 		}

lightning/src/ln/peer_handler.rs

@@ -1477,6 +1477,9 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 							msg.sync_complete);
 						self.enqueue_message(get_peer_for_forwarding!(node_id), msg);
 					}
+					MessageSendEvent::SendGossipTimestampFilter { ref node_id, ref msg } => {
+						self.enqueue_message(get_peer_for_forwarding!(node_id), msg);
+					}
 				}
 			}
 

lightning/src/routing/network_graph.rs

@@ -25,7 +25,7 @@ use chain;
 use chain::Access;
 use ln::features::{ChannelFeatures, NodeFeatures};
 use ln::msgs::{DecodeError, ErrorAction, Init, LightningError, RoutingMessageHandler, NetAddress, MAX_VALUE_MSAT};
-use ln::msgs::{ChannelAnnouncement, ChannelUpdate, NodeAnnouncement, OptionalField};
+use ln::msgs::{ChannelAnnouncement, ChannelUpdate, NodeAnnouncement, OptionalField, GossipTimestampFilter};
 use ln::msgs::{QueryChannelRange, ReplyChannelRange, QueryShortChannelIds, ReplyShortChannelIdsEnd};
 use ln::msgs;
 use util::ser::{Writeable, Readable, Writer};
@@ -401,6 +401,22 @@ where C::Target: chain::Access, L::Target: Logger
 			return ();
 		}
 
+		// Send a gossip_timestamp_filter to enable gossip message receipt. Note that we have to
+		// use a "all timestamps" filter as sending the current timestamp would result in missing
+		// gossip messages that are simply sent late. We could calculate the intended filter time
+		// by looking at the current time and subtracting two weeks (before which we'll reject
+		// messages), but there's not a lot of reason to bother - our peers should be discarding
+		// the same messages.
+		let mut pending_events = self.pending_events.lock().unwrap();
+		pending_events.push(MessageSendEvent::SendGossipTimestampFilter {
+			node_id: their_node_id.clone(),
+			msg: GossipTimestampFilter {
+				chain_hash: self.network_graph.genesis_hash,
+				first_timestamp: 0,
+				timestamp_range: u32::max_value(),
+			},
+		});
+
 		// Check if we need to perform a full synchronization with this peer
 		if !self.should_request_full_sync(&their_node_id) {
 			return ();
@@ -409,7 +425,6 @@ where C::Target: chain::Access, L::Target: Logger
 		let first_blocknum = 0;
 		let number_of_blocks = 0xffffffff;
 		log_debug!(self.logger, "Sending query_channel_range peer={}, first_blocknum={}, number_of_blocks={}", log_pubkey!(their_node_id), first_blocknum, number_of_blocks);
-		let mut pending_events = self.pending_events.lock().unwrap();
 		pending_events.push(MessageSendEvent::SendChannelRangeQuery {
 			node_id: their_node_id.clone(),
 			msg: QueryChannelRange {
@@ -2280,8 +2295,17 @@ mod tests {
 			let init_msg = Init { features: InitFeatures::known() };
 			net_graph_msg_handler.peer_connected(&node_id_1, &init_msg);
 			let events = net_graph_msg_handler.get_and_clear_pending_msg_events();
-			assert_eq!(events.len(), 1);
+			assert_eq!(events.len(), 2);
 			match &events[0] {
+				MessageSendEvent::SendGossipTimestampFilter{ node_id, msg } => {
+					assert_eq!(node_id, &node_id_1);
+					assert_eq!(msg.chain_hash, chain_hash);
+					assert_eq!(msg.first_timestamp, 0);
+					assert_eq!(msg.timestamp_range, u32::max_value());
+				},
+				_ => panic!("Expected MessageSendEvent::SendChannelRangeQuery")
+			};
+			match &events[1] {
 				MessageSendEvent::SendChannelRangeQuery{ node_id, msg } => {
 					assert_eq!(node_id, &node_id_1);
 					assert_eq!(msg.chain_hash, chain_hash);
@@ -2305,9 +2329,11 @@ mod tests {
 				net_graph_msg_handler.peer_connected(&node_id, &init_msg);
 				let events = net_graph_msg_handler.get_and_clear_pending_msg_events();
 				if n <= 5 {
-					assert_eq!(events.len(), 1);
+					assert_eq!(events.len(), 2);
 				} else {
-					assert_eq!(events.len(), 0);
+					// Even after the we stop sending the explicit query, we should still send a
+					// gossip_timestamp_filter on each new connection.
+					assert_eq!(events.len(), 1);
 				}
 
 			}

lightning/src/util/events.rs

@@ -909,7 +909,15 @@ pub enum MessageSendEvent {
 		node_id: PublicKey,
 		/// The reply_channel_range which should be sent.
 		msg: msgs::ReplyChannelRange,
-	}
+	},
+	/// Sends a timestamp filter for inbound gossip. This should be sent on each new connection to
+	/// enable receiving gossip messages from the peer.
+	SendGossipTimestampFilter {
+		/// The node_id of this message recipient
+		node_id: PublicKey,
+		/// The gossip_timestamp_filter which should be sent.
+		msg: msgs::GossipTimestampFilter,
+	},
 }
 
 /// A trait indicating an object may generate message send events