gossip: Implemented routing table sync with newly connected peers

daemon/p2p_announce.c

@@ -113,8 +113,8 @@ static bool add_channel_direction(struct lightningd_state *dstate,
 				  const struct pubkey *from,
 				  const struct pubkey *to,
 				  const int direction,
-				  const struct channel_id *channel_id
-	)
+				  const struct channel_id *channel_id,
+				  const u8 *announcement)
 {
 	struct node_connection *c = get_connection(dstate, from, to);
 	if (c){
@@ -126,10 +126,13 @@ static bool add_channel_direction(struct lightningd_state *dstate,
 	}else if(get_connection_by_cid(dstate, channel_id, direction)) {
 		return false;
 	}
-	half_add_connection(dstate,
-			    from,
-			    to,
-			    channel_id, direction);
+
+	c = half_add_connection(dstate, from, to, channel_id, direction);
+
+	/* Remember the announcement so we can forward it to new peers */
+	tal_free(c->channel_announcement);
+	c->channel_announcement = tal_dup_arr(c, u8, announcement,
+					      tal_count(announcement), 0);
 	return true;
 }
 
@@ -145,29 +148,32 @@ void handle_channel_announcement(
 	//FIXME(cdecker) Check signatures, when the spec is settled
 	//FIXME(cdecker) Check chain topology for the anchor TX
 
-	log_debug(peer->log, "Received channel_announcement for channel %d:%d:%d",
+	serialized = towire_channel_announcement(msg, msg);
+
+	log_debug(peer->log,
+		  "Received channel_announcement for channel %d:%d:%d",
 		  msg->channel_id.blocknum,
 		  msg->channel_id.txnum,
 		  msg->channel_id.outnum
 		);
+
 	forward |= add_channel_direction(peer->dstate, &msg->node_id_1,
-					 &msg->node_id_2, 0, &msg->channel_id);
+					 &msg->node_id_2, 0, &msg->channel_id,
+					 serialized);
 	forward |= add_channel_direction(peer->dstate, &msg->node_id_2,
-					 &msg->node_id_1, 1, &msg->channel_id);
+					 &msg->node_id_1, 1, &msg->channel_id,
+					 serialized);
 	if (!forward){
 		log_debug(peer->log, "Not forwarding channel_announcement");
 		return;
 	}
 
-	serialized = towire_channel_announcement(msg, msg);
-
 	u8 *tag = tal_arr(msg, u8, 0);
 	towire_channel_id(&tag, &msg->channel_id);
-	queue_broadcast(peer->dstate,
-			WIRE_CHANNEL_ANNOUNCEMENT,
+	queue_broadcast(peer->dstate, WIRE_CHANNEL_ANNOUNCEMENT,
 			0, /* `channel_announcement`s do not have a timestamp */
-			tag,
-			serialized, peer);
+			tag, serialized, peer);
+
 	tal_free(msg);
 }
 
@@ -223,6 +229,9 @@ void handle_channel_update(struct peer *peer, const struct msg_channel_update *m
 			msg->timestamp,
 			tag,
 			serialized, peer);
+
+	tal_free(c->channel_update);
+	c->channel_update = tal_dup_arr(c, u8, serialized, tal_count(serialized), 0);
 	tal_free(msg);
 }
 
@@ -273,6 +282,8 @@ void handle_node_announcement(
 			msg->timestamp,
 			tag,
 			serialized, peer);
+	tal_free(node->node_announcement);
+	node->node_announcement = tal_dup_arr(node, u8, serialized, tal_count(serialized), 0);
 	tal_free(msg);
 }
 
@@ -325,7 +336,6 @@ static void broadcast_node_announcement(struct lightningd_state *dstate)
 	serialized = towire_node_announcement(msg, msg);
 	broadcast(dstate, WIRE_NODE_ANNOUNCEMENT, serialized, NULL);
 	tal_free(msg);
-
 }
 
 static void broadcast_channel_announcement(struct lightningd_state *dstate, struct peer *peer)

daemon/peer.c

@@ -747,6 +747,7 @@ static bool open_wait_pkt_in(struct peer *peer, const Pkt *pkt)
 			peer_open_complete(peer, NULL);
 			set_peer_state(peer, STATE_NORMAL, __func__, true);
 			announce_channel(peer->dstate, peer);
+			sync_routing_table(peer->dstate, peer);
 		} else {
 			set_peer_state(peer, STATE_OPEN_WAIT_ANCHORDEPTH,
 				       __func__, true);
@@ -2529,8 +2530,10 @@ static struct io_plan *init_pkt_in(struct io_conn *conn, struct peer *peer)
 
 	peer_has_connected(peer);
 
-	if (state_is_normal(peer->state))
+	if (state_is_normal(peer->state)){
 		announce_channel(peer->dstate, peer);
+		sync_routing_table(peer->dstate, peer);
+	}
 
 	return io_duplex(conn,
 			 peer_read_packet(conn, peer, pkt_in),
@@ -3317,6 +3320,7 @@ static void peer_depth_ok(struct peer *peer)
 		peer_open_complete(peer, NULL);
 		set_peer_state(peer, STATE_NORMAL, __func__, true);
 		announce_channel(peer->dstate, peer);
+		sync_routing_table(peer->dstate, peer);
 		break;
 	default:
 		log_broken(peer->log, "%s: state %s",

daemon/routing.c

@@ -2,6 +2,7 @@
 #include "lightningd.h"
 #include "log.h"
 #include "overflows.h"
+#include "packets.h"
 #include "peer.h"
 #include "pseudorand.h"
 #include "routing.h"
@@ -67,6 +68,7 @@ struct node *new_node(struct lightningd_state *dstate,
 	n->port = 0;
 	n->alias = NULL;
 	n->hostname = NULL;
+	n->node_announcement = NULL;
 	node_map_add(dstate->nodes, n);
 	tal_add_destructor(n, destroy_node);
 
@@ -195,6 +197,8 @@ get_or_make_connection(struct lightningd_state *dstate,
 	nc->src = from;
 	nc->dst = to;
 	memset(&nc->channel_id, 0, sizeof(nc->channel_id));
+	nc->channel_announcement = NULL;
+	nc->channel_update = NULL;
 	log_add(dstate->base_log, " = %p (%p->%p)", nc, from, to);
 
 	/* Hook it into in/out arrays. */
@@ -551,6 +555,26 @@ static void json_add_route(struct command *cmd,
 	command_success(cmd, null_response(cmd));
 }
 
+void sync_routing_table(struct lightningd_state *dstate, struct peer *peer)
+{
+	struct node *n;
+	struct node_map_iter it;
+	int i;
+	struct node_connection *nc;
+	for (n = node_map_first(dstate->nodes, &it); n; n = node_map_next(dstate->nodes, &it)) {
+		size_t num_edges = tal_count(n->out);
+		for (i = 0; i < num_edges; i++) {
+			nc = n->out[i];
+			if (nc->channel_announcement)
+				queue_pkt_nested(peer, WIRE_CHANNEL_ANNOUNCEMENT, nc->channel_announcement);
+			if (nc->channel_update)
+				queue_pkt_nested(peer, WIRE_CHANNEL_UPDATE, nc->channel_update);
+		}
+		if (n->node_announcement)
+			queue_pkt_nested(peer, WIRE_NODE_ANNOUNCEMENT, n->node_announcement);
+	}
+}
+
 const struct json_command dev_add_route_command = {
 	"dev-add-route",
 	json_add_route,

daemon/routing.h

@@ -32,6 +32,10 @@ struct node_connection {
 	/* Flags as specified by the `channel_update`s, among other
 	 * things indicated direction wrt the `channel_id` */
 	u16 flags;
+
+	/* Cached `channel_announcement` and `channel_update` we might forward to new peers*/
+	u8 *channel_announcement;
+	u8 *channel_update;
 };
 
 struct node {
@@ -61,6 +65,9 @@ struct node {
 
 	/* Color to be used when displaying the name */
 	u8 rgb_color[3];
+
+	/* Cached `node_announcement` we might forward to new peers. */
+	u8 *node_announcement;
 };
 
 struct lightningd_state;
@@ -125,4 +132,7 @@ struct node_map *empty_node_map(struct lightningd_state *dstate);
 
 char *opt_add_route(const char *arg, struct lightningd_state *dstate);
 
+/* Dump all known channels and nodes to the peer. Used when a new connection was established. */
+void sync_routing_table(struct lightningd_state *dstate, struct peer *peer);
+
 #endif /* LIGHTNING_DAEMON_ROUTING_H */