lightningd: tell connectd about the custom messages.

We re-send whenever a plugin which allows them starts/finishes.

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

connectd/connectd.c

@@ -2100,6 +2100,10 @@ static struct io_plan *recv_req(struct io_conn *conn,
 		start_shutdown(daemon, msg);
 		goto out;
 
+	case WIRE_CONNECTD_SET_CUSTOMMSGS:
+		set_custommsgs(daemon, msg);
+		goto out;
+
 	case WIRE_CONNECTD_DEV_MEMLEAK:
 		if (daemon->developer) {
 			dev_connect_memleak(daemon, msg);
@@ -2209,6 +2213,7 @@ int main(int argc, char *argv[])
 	daemon->gossip_store_fd = -1;
 	daemon->shutting_down = false;
 	daemon->dev_suppress_gossip = false;
+	daemon->custom_msgs = NULL;
 
 	/* stdin == control */
 	daemon->master = daemon_conn_new(daemon, STDIN_FILENO, recv_req, NULL,

connectd/connectd.h

@@ -194,6 +194,9 @@ struct daemon {
 	/* Shutting down, don't send new stuff */
 	bool shutting_down;
 
+	/* What (even) custom messages we accept */
+	u16 *custom_msgs;
+
 	/* Hack to speed up gossip timer */
 	bool dev_fast_gossip;
 	/* Hack to avoid ping timeouts */

connectd/connectd_wire.csv

@@ -40,6 +40,11 @@ msgtype,connectd_activate,2025
 # Do we listen?
 msgdata,connectd_activate,listen,bool,
 
+# Set the allowed (i.e. don't hang up on!) unknown messages.
+msgtype,connectd_set_custommsgs,2007
+msgdata,connectd_set_custommsgs,len,u32,
+msgdata,connectd_set_custommsgs,msgnums,u16,len
+
 # Connectd->master, I am ready.
 msgtype,connectd_activate_reply,2125
 msgdata,connectd_activate_reply,failmsg,?wirestring,

connectd/multiplex.c

@@ -559,6 +559,13 @@ static void send_ping(struct peer *peer)
 	set_ping_timer(peer);
 }
 
+void set_custommsgs(struct daemon *daemon, const u8 *msg)
+{
+	tal_free(daemon->custom_msgs);
+	if (!fromwire_connectd_set_custommsgs(daemon, msg, &daemon->custom_msgs))
+		master_badmsg(WIRE_CONNECTD_SET_CUSTOMMSGS, msg);
+}
+
 void send_custommsg(struct daemon *daemon, const u8 *msg)
 {
 	struct node_id id;
@@ -701,24 +708,44 @@ static void handle_gossip_timestamp_filter_in(struct peer *peer, const u8 *msg)
 		wake_gossip(peer);
 }
 
+static bool find_custom_msg(const u16 *custom_msgs, u16 type)
+{
+	for (size_t i = 0; i < tal_count(custom_msgs); i++) {
+		if (custom_msgs[i] == type)
+			return true;
+	}
+	return false;
+}
+
 static bool handle_custommsg(struct daemon *daemon,
 			     struct peer *peer,
 			     const u8 *msg)
 {
 	enum peer_wire type = fromwire_peektype(msg);
-	if (type % 2 == 1 && !peer_wire_is_internal(type)) {
-		/* The message is not part of the messages we know how to
-		 * handle. Assuming this is a custommsg, we just forward it to the
-		 * master. */
-		status_peer_io(LOG_IO_IN, &peer->id, msg);
-		daemon_conn_send(daemon->master,
-				 take(towire_connectd_custommsg_in(NULL,
-								   &peer->id,
-								   msg)));
-		return true;
-	} else {
+
+	/* Messages we expect to handle ourselves. */
+	if (peer_wire_is_internal(type))
 		return false;
+
+	/* We log it, since it's not going to a subdaemon */
+	status_peer_io(LOG_IO_IN, &peer->id, msg);
+
+	/* Even unknown messages must be explicitly allowed */
+	if (type % 2 == 0 && !find_custom_msg(daemon->custom_msgs, type)) {
+		send_warning(peer, "Invalid unknown even msg %s",
+			     tal_hex(msg, msg));
+		/* We "handled" it... */
+		return true;
 	}
+
+	/* The message is not part of the messages we know how to
+	 * handle. Assuming this is a custommsg, we just forward it to the
+	 * master. */
+	daemon_conn_send(daemon->master,
+			 take(towire_connectd_custommsg_in(NULL,
+							   &peer->id,
+							   msg)));
+	return true;
 }
 
 /* We handle pings and gossip messages. */

connectd/multiplex.h

@@ -32,6 +32,9 @@ void send_manual_ping(struct daemon *daemon, const u8 *msg);
 /* When lightningd says to send a custom message (from a plugin) */
 void send_custommsg(struct daemon *daemon, const u8 *msg);
 
+/* When lightningd says what custom messages we can recv */
+void set_custommsgs(struct daemon *daemon, const u8 *msg);
+
 /* Lightningd wants to talk to you. */
 void peer_connect_subd(struct daemon *daemon, const u8 *msg, int fd);
 

lightningd/connect_control.c

@@ -579,6 +579,7 @@ static unsigned connectd_msg(struct subd *connectd, const u8 *msg, const int *fd
 	case WIRE_CONNECTD_SEND_ONIONMSG:
 	case WIRE_CONNECTD_CUSTOMMSG_OUT:
 	case WIRE_CONNECTD_START_SHUTDOWN:
+	case WIRE_CONNECTD_SET_CUSTOMMSGS:
 	/* This is a reply, so never gets through to here. */
 	case WIRE_CONNECTD_INIT_REPLY:
 	case WIRE_CONNECTD_ACTIVATE_REPLY:

lightningd/plugin.c

@@ -16,6 +16,7 @@
 #include <common/memleak.h>
 #include <common/timeout.h>
 #include <common/version.h>
+#include <connectd/connectd_wiregen.h>
 #include <dirent.h>
 #include <errno.h>
 #include <lightningd/io_loop_with_timers.h>
@@ -23,6 +24,7 @@
 #include <lightningd/plugin.h>
 #include <lightningd/plugin_control.h>
 #include <lightningd/plugin_hook.h>
+#include <lightningd/subd.h>
 #include <sys/stat.h>
 
 /* Only this file can include this generated header! */
@@ -192,6 +194,32 @@ struct command_result *plugin_register_all_complete(struct lightningd *ld,
 	return NULL;
 }
 
+static void tell_connectd_custommsgs(struct plugins *plugins)
+{
+	struct plugin *p;
+	size_t n = 0;
+	u16 *all_msgs = tal_arr(tmpctx, u16, n);
+
+	/* Not when shutting down */
+	if (!plugins->ld->connectd)
+		return;
+
+	/* Gather from all plugins. */
+	list_for_each(&plugins->plugins, p, list) {
+		size_t num = tal_count(p->custom_msgs);
+		/* Blah blah blah memcpy NULL blah blah */
+		if (num == 0)
+			continue;
+		tal_resize(&all_msgs, n + num);
+		memcpy(all_msgs + n, p->custom_msgs, num * sizeof(*p->custom_msgs));
+		n += num;
+	}
+
+	/* Don't bother sorting or uniquifying.  If plugins are dumb, they deserve it. */
+	subd_send_msg(plugins->ld->connectd,
+		      take(towire_connectd_set_custommsgs(NULL, all_msgs)));
+}
+
 static void destroy_plugin(struct plugin *p)
 {
 	struct plugin_rpccall *call;
@@ -232,6 +260,9 @@ static void destroy_plugin(struct plugin *p)
 			   "shutting down lightningd!");
 		lightningd_exit(p->plugins->ld, 1);
 	}
+
+	if (tal_count(p->custom_msgs))
+		tell_connectd_custommsgs(p->plugins);
 }
 
 static u32 file_checksum(struct lightningd *ld, const char *path)
@@ -1950,6 +1981,8 @@ static void plugin_config_cb(const char *buffer,
 		plugin_cmd_succeeded(plugin->start_cmd, plugin);
 		plugin->start_cmd = NULL;
 	}
+	if (tal_count(plugin->custom_msgs))
+		tell_connectd_custommsgs(plugin->plugins);
 	check_plugins_initted(plugin->plugins);
 }