xC: enable relay binding on multiple addresses

NEWS

@@ -1,5 +1,7 @@
 Unreleased
 
+ * xC: general.relay_bind is now a string array
+
  * xC + all frontends: M-a now prioritizes highlights, newly added M-A looks
    for buffers in reverse order, and the old M-! binding has been removed
 

xC.c

@@ -2061,7 +2061,7 @@ struct app_context
 
 	struct poller_fd tty_event;         ///< Terminal input event
 	struct poller_fd signal_event;      ///< Signal FD event
-	struct poller_fd relay_event;       ///< New relay connection available
+	struct poller_fd *relay_events;     ///< New relay connections available
 
 	struct poller_timer flush_timer;    ///< Flush all open files (e.g. logs)
 	struct poller_timer date_chg_tmr;   ///< Print a date change
@@ -2108,7 +2108,8 @@ struct app_context
 
 	// Relay:
 
-	int relay_fd;                       ///< Listening socket FD
+	int *relay_fds;                     ///< Listening socket FDs
+	size_t relay_len;                   ///< Number of listening sockets
 	struct client *clients;             ///< Our relay clients
 	struct client *clients_tail;        ///< End of the clients list
 	unsigned relay_resume_timeout;      ///< Detached session TTL in seconds
@@ -2181,19 +2182,21 @@ app_context_init (struct app_context *self)
 
 	self->nick_palette =
 		filter_color_cube_for_acceptable_nick_colors (&self->nick_palette_len);
-
-	self->relay_fd = -1;
 }
 
 static void
 app_context_relay_stop (struct app_context *self)
 {
-	if (self->relay_fd != -1)
+	for (size_t i = 0; i < self->relay_len; i++)
 	{
-		poller_fd_reset (&self->relay_event);
-		xclose (self->relay_fd);
-		self->relay_fd = -1;
+		poller_fd_reset (&self->relay_events[i]);
+		xclose (self->relay_fds[i]);
 	}
+	free (self->relay_events);
+	free (self->relay_fds);
+	self->relay_events = NULL;
+	self->relay_fds = NULL;
+	self->relay_len = 0;
 }
 
 static void
@@ -2458,8 +2461,8 @@ static const struct config_schema g_config_general[] =
 
 	// Relay:
 	{ .name      = "relay_bind",
-	  .comment   = "Address to bind to for a user interface relay point",
-	  .type      = CONFIG_ITEM_STRING,
+	  .comment   = "Addresses to bind to for user interface relay points",
+	  .type      = CONFIG_ITEM_STRING_ARRAY,
 	  .validate  = config_validate_nonjunk_string,
 	  .on_change = on_config_relay_bind_change },
 	{ .name      = "relay_resume_log_limit",
@@ -12175,7 +12178,7 @@ handle_command_relay (struct handler_args *a)
 	LIST_FOR_EACH (struct client, c, a->ctx->clients)
 		len++;
 
-	if (a->ctx->relay_fd == -1)
+	if (!a->ctx->relay_len)
 		log_global_status (a->ctx, "The relay is not enabled");
 	else
 		log_global_status (a->ctx, "The relay has #d clients", len);
@@ -15694,12 +15697,12 @@ relay_start (struct app_context *ctx, char *address, struct error **e)
 
 	set_blocking (fd, false);
 
-	struct poller_fd *event = &ctx->relay_event;
+	struct poller_fd *event = &ctx->relay_events[ctx->relay_len];
 	*event = poller_fd_make (&ctx->poller, fd);
 	event->dispatcher = (poller_fd_fn) on_relay_client_available;
 	event->user_data = ctx;
 
-	ctx->relay_fd = fd;
+	ctx->relay_fds[ctx->relay_len++] = fd;
 	poller_fd_set (event, POLLIN);
 	return true;
 }
@@ -15708,21 +15711,29 @@ static void
 on_config_relay_bind_change (struct config_item *item)
 {
 	struct app_context *ctx = item->user_data;
-	char *value = item->value.string.str;
 	app_context_relay_stop (ctx);
-	if (!value)
+	if (item->type == CONFIG_ITEM_NULL)
 		return;
 
-	// XXX: This should perhaps be reencoded as the locale encoding.
-	char *address = xstrdup (value);
+	struct strv addresses = strv_make ();
+	cstr_split (item->value.string.str, ",", true, &addresses);
 
-	struct error *e = NULL;
-	if (!relay_start (ctx, address, &e))
+	ctx->relay_fds = xcalloc (addresses.len, sizeof *ctx->relay_fds);
+	ctx->relay_events = xcalloc (addresses.len, sizeof *ctx->relay_events);
+	for (size_t i = 0; i < addresses.len; i++)
 	{
-		log_global_error (ctx, "#s: #l", item->schema->name, e->message);
-		error_free (e);
+		// XXX: This should perhaps be reencoded as the locale encoding.
+		char *address = xstrdup (addresses.vector[i]);
+		struct error *e = NULL;
+		if (!relay_start (ctx, address, &e))
+		{
+			log_global_error (ctx, "#s: address `#l': #l",
+				item->schema->name, addresses.vector[i], e->message);
+			error_free (e);
+		}
+		free (address);
 	}
-	free (address);
+	strv_free (&addresses);
 }
 
 static void