gossipd: dev-suppress-gossip.

Useful for testing that we only get an update via the error message.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

gossipd/gossip.c

@@ -60,6 +60,7 @@
 
 #if DEVELOPER
 static u32 max_scids_encode_bytes = -1U;
+static bool suppress_gossip = false;
 #endif
 
 struct local_update {
@@ -908,6 +909,11 @@ static bool maybe_queue_gossip(struct peer *peer)
 	if (peer->gossip_timer)
 		return false;
 
+#if DEVELOPER
+	if (suppress_gossip)
+		return false;
+#endif
+
 	next = next_broadcast(peer->daemon->rstate->broadcasts,
 			      peer->gossip_timestamp_min,
 			      peer->gossip_timestamp_max,
@@ -1731,6 +1737,18 @@ static struct io_plan *dev_set_max_scids_encode_size(struct io_conn *conn,
 	status_trace("Set max_scids_encode_bytes to %u", max_scids_encode_bytes);
 	return daemon_conn_read_next(conn, &daemon->master);
 }
+
+static struct io_plan *dev_gossip_suppress(struct io_conn *conn,
+					   struct daemon *daemon,
+					   const u8 *msg)
+{
+	if (!fromwire_gossip_dev_suppress(msg))
+		master_badmsg(WIRE_GOSSIP_DEV_SUPPRESS, msg);
+
+	status_unusual("Suppressing all gossip");
+	suppress_gossip = true;
+	return daemon_conn_read_next(conn, &daemon->master);
+}
 #endif /* DEVELOPER */
 
 static void gossip_send_keepalive_update(struct routing_state *rstate,
@@ -2126,12 +2144,16 @@ static struct io_plan *recv_req(struct io_conn *conn, struct daemon_conn *master
 	case WIRE_GOSSIP_DEV_SET_MAX_SCIDS_ENCODE_SIZE:
 		return dev_set_max_scids_encode_size(conn, daemon,
 						     daemon->master.msg_in);
+	case WIRE_GOSSIP_DEV_SUPPRESS:
+		return dev_gossip_suppress(conn, daemon,
+					   daemon->master.msg_in);
 #else
 	case WIRE_GOSSIP_PING:
 	case WIRE_GOSSIP_QUERY_SCIDS:
 	case WIRE_GOSSIP_SEND_TIMESTAMP_FILTER:
 	case WIRE_GOSSIP_QUERY_CHANNEL_RANGE:
 	case WIRE_GOSSIP_DEV_SET_MAX_SCIDS_ENCODE_SIZE:
+	case WIRE_GOSSIP_DEV_SUPPRESS:
 		break;
 #endif /* !DEVELOPER */
 

gossipd/gossip_wire.csv

@@ -160,3 +160,6 @@ gossip_mark_channel_unroutable,,channel,struct short_channel_id
 # master -> gossipd: a potential funding outpoint was spent, please forget the eventual channel
 gossip_outpoint_spent,3024
 gossip_outpoint_spent,,short_channel_id,struct short_channel_id
+
+# master -> gossipd: stop gossip timers.
+gossip_dev_suppress,3032

lightningd/gossip_control.c

@@ -115,6 +115,7 @@ static unsigned gossip_msg(struct subd *gossip, const u8 *msg, const int *fds)
 	case WIRE_GOSSIP_QUERY_CHANNEL_RANGE:
 	case WIRE_GOSSIP_SEND_TIMESTAMP_FILTER:
 	case WIRE_GOSSIP_DEV_SET_MAX_SCIDS_ENCODE_SIZE:
+	case WIRE_GOSSIP_DEV_SUPPRESS:
 	/* This is a reply, so never gets through to here. */
 	case WIRE_GOSSIP_GET_UPDATE_REPLY:
 	case WIRE_GOSSIP_GETNODES_REPLY:
@@ -594,4 +595,23 @@ static const struct json_command dev_set_max_scids_encode_size = {
 	"Set {max} bytes of short_channel_ids per reply_channel_range"
 };
 AUTODATA(json_command, &dev_set_max_scids_encode_size);
+
+static void json_dev_suppress_gossip(struct command *cmd,
+				     const char *buffer,
+				     const jsmntok_t *params)
+{
+	if (!param(cmd, buffer, params, NULL))
+		return;
+
+	subd_send_msg(cmd->ld->gossip, take(towire_gossip_dev_suppress(NULL)));
+
+	command_success(cmd, null_response(cmd));
+}
+
+static const struct json_command dev_suppress_gossip = {
+	"dev-suppress-gossip",
+	json_dev_suppress_gossip,
+	"Stop this node from sending any more gossip."
+};
+AUTODATA(json_command, &dev_suppress_gossip);
 #endif /* DEVELOPER */