dispatcher: only dispatch if scripts exist

If there are no dispatcher scripts, don't bother dispatching any
events.  This saves some time configuring networking if the event
would have no effect anyway.

callouts/nm-dispatcher-api.h

@@ -20,6 +20,8 @@
 
 #include <dbus/dbus-glib.h>
 
+#define NMD_SCRIPT_DIR NMCONFDIR "/dispatcher.d"
+
 /* dbus-glib types for dispatcher call return value */
 #define DISPATCHER_TYPE_RESULT       (dbus_g_type_get_struct ("GValueArray", G_TYPE_STRING, G_TYPE_UINT, G_TYPE_STRING, G_TYPE_INVALID))
 #define DISPATCHER_TYPE_RESULT_ARRAY (dbus_g_type_get_collection ("GPtrArray", DISPATCHER_TYPE_RESULT))

callouts/nm-dispatcher.c

@@ -41,8 +41,6 @@
 #include "nm-dispatcher-utils.h"
 #include "nm-glib-compat.h"
 
-#define NMD_SCRIPT_DIR NMCONFDIR "/dispatcher.d"
-
 static GMainLoop *loop = NULL;
 static gboolean debug = FALSE;
 

src/main.c

@@ -54,6 +54,7 @@
 #include "nm-config.h"
 #include "nm-posix-signals.h"
 #include "nm-session-monitor.h"
+#include "nm-dispatcher.h"
 
 #if !defined(NM_DIST_VERSION)
 # define NM_DIST_VERSION VERSION
@@ -604,6 +605,8 @@ main (int argc, char *argv[])
 	dhcp_mgr = nm_dhcp_manager_get ();
 	g_assert (dhcp_mgr != NULL);
 
+	nm_dispatcher_init ();
+
 	settings = nm_settings_new (&error);
 	if (!settings) {
 		nm_log_err (LOGD_CORE, "failed to initialize settings storage: %s",

src/nm-dispatcher.c

@@ -31,6 +31,7 @@
 #include "nm-dbus-glib-types.h"
 #include "nm-glib-compat.h"
 
+static gboolean do_dispatch = TRUE;
 static GSList *requests = NULL;
 
 static void
@@ -134,12 +135,15 @@ fill_vpn_props (NMIP4Config *ip4_config,
 typedef struct {
 	DispatcherFunc callback;
 	gpointer user_data;
+	guint idle_id;
 } DispatchInfo;
 
 static void
 dispatcher_info_free (DispatchInfo *info)
 {
 	requests = g_slist_remove (requests, info);
+	if (info->idle_id)
+		g_source_remove (info->idle_id);
 	g_free (info);
 }
 
@@ -261,6 +265,18 @@ action_to_string (DispatcherAction action)
 	g_assert_not_reached ();
 }
 
+static gboolean
+dispatcher_idle_cb (gpointer user_data)
+{
+	DispatchInfo *info = user_data;
+
+	info->idle_id = 0;
+	if (info->callback)
+		info->callback (info, info->user_data);
+	dispatcher_info_free (info);
+	return G_SOURCE_REMOVE;
+}
+
 static gconstpointer
 _dispatcher_call (DispatcherAction action,
                   NMConnection *connection,
@@ -299,6 +315,16 @@ _dispatcher_call (DispatcherAction action,
 	if (action == DISPATCHER_ACTION_VPN_UP)
 		g_return_val_if_fail (vpn_ip4_config != NULL, NULL);
 
+	if (do_dispatch == FALSE) {
+		info = g_malloc0 (sizeof (*info));
+		info->callback = callback;
+		info->user_data = user_data;
+		info->idle_id = g_idle_add (dispatcher_idle_cb, info);
+		requests = g_slist_append (requests, info);
+		nm_log_dbg (LOGD_DISPATCH, "ignoring request; no scripts in " NMD_SCRIPT_DIR);
+		return info;
+	}
+
 	g_connection = nm_dbus_manager_get_connection (nm_dbus_manager_get ());
 	proxy = dbus_g_proxy_new_for_name (g_connection,
 	                                   NM_DISPATCHER_DBUS_SERVICE,
@@ -416,3 +442,32 @@ nm_dispatcher_call_cancel (gconstpointer call)
 		((DispatchInfo *) call)->callback = NULL;
 }
 
+static void
+dispatcher_dir_changed (GFileMonitor *monitor)
+{
+	GDir *dir;
+
+	/* Default to dispatching on any errors */
+	do_dispatch = TRUE;
+	dir = g_dir_open (NMD_SCRIPT_DIR, 0, NULL);
+	if (dir) {
+		do_dispatch = !!g_dir_read_name (dir);
+		g_dir_close (dir);
+	}
+}
+
+void
+nm_dispatcher_init (void)
+{
+	GFile *file;
+	static GFileMonitor *monitor;
+
+	file = g_file_new_for_path (NMD_SCRIPT_DIR);
+	monitor = g_file_monitor_directory (file, G_FILE_MONITOR_NONE, NULL, NULL);
+	if (monitor) {
+		g_signal_connect (monitor, "changed", G_CALLBACK (dispatcher_dir_changed), NULL);
+		dispatcher_dir_changed (monitor);
+	}
+	g_object_unref (file);
+}
+

src/nm-dispatcher.h

@@ -61,4 +61,6 @@ gconstpointer nm_dispatcher_call_vpn (DispatcherAction action,
 
 void nm_dispatcher_call_cancel (gconstpointer call);
 
+void nm_dispatcher_init (void);
+
 #endif /* NM_DISPATCHER_H */