sleep-monitor: make the systemd's sleep also work for GLib < 2.30

GDBus is only available from glib 2.26 and GUnixFDList from glib 2.30

src/nm-sleep-monitor-systemd.c

@@ -35,11 +35,20 @@
 #define SD_PATH              "/org/freedesktop/login1"
 #define SD_INTERFACE         "org.freedesktop.login1.Manager"
 
+/* Do we have GDBus (glib >= 2.26) and GUnixFDList (glib >= 2.30) support ? */
+#if GLIB_CHECK_VERSION(2,30,0)
+#define IS_GDBUS_UNIXFD_AVAILABLE 1
+#endif
+
 
 struct _NMSleepMonitor {
 	GObject parent_instance;
 
+#if defined(IS_GDBUS_UNIXFD_AVAILABLE)
 	GDBusProxy *sd_proxy;
+#else
+	DBusGProxy *sd_proxy;
+#endif
 	gint inhibit_fd;
 };
 
@@ -62,6 +71,20 @@ G_DEFINE_TYPE (NMSleepMonitor, nm_sleep_monitor, G_TYPE_OBJECT);
 
 /********************************************************************/
 
+static gboolean
+drop_inhibitor (NMSleepMonitor *self)
+{
+	if (self->inhibit_fd >= 0) {
+		nm_log_dbg (LOGD_SUSPEND, "Dropping systemd sleep inhibitor");
+		close (self->inhibit_fd);
+		self->inhibit_fd = -1;
+		return TRUE;
+	}
+	return FALSE;
+}
+
+#if defined(IS_GDBUS_UNIXFD_AVAILABLE)
+/* Great! We have GDBus (glib >= 2.26) and GUnixFDList (glib >= 2.30) */
 static void
 inhibit_done (GObject      *source,
               GAsyncResult *result,
@@ -110,18 +133,6 @@ take_inhibitor (NMSleepMonitor *self)
 	                                     self);
 }
 
-static gboolean
-drop_inhibitor (NMSleepMonitor *self)
-{
-	if (self->inhibit_fd >= 0) {
-		nm_log_dbg (LOGD_SUSPEND, "Dropping systemd sleep inhibitor");
-		close (self->inhibit_fd);
-		self->inhibit_fd = -1;
-		return TRUE;
-	}
-	return FALSE;
-}
-
 static void
 signal_cb (GDBusProxy  *proxy,
            const gchar *sendername,
@@ -148,17 +159,153 @@ signal_cb (GDBusProxy  *proxy,
 }
 
 static void
-nm_sleep_monitor_init (NMSleepMonitor *self)
+sleep_setup (NMSleepMonitor *self)
 {
 	GDBusConnection *bus;
 
-	self->inhibit_fd = -1;
 	bus = g_bus_get_sync (G_BUS_TYPE_SYSTEM, NULL, NULL);
 	self->sd_proxy = g_dbus_proxy_new_sync (bus, 0, NULL,
 	                                        SD_NAME, SD_PATH, SD_INTERFACE,
 	                                        NULL, NULL);
 	g_object_unref (bus);
 	g_signal_connect (self->sd_proxy, "g-signal", G_CALLBACK (signal_cb), self);
+}
+
+#else
+
+/* GDBus nor GUnixFDList available. We have to get by with dbus-glib and libdbus */
+static void
+inhibit_done (DBusPendingCall *pending,
+              gpointer user_data)
+{
+	NMSleepMonitor *self = user_data;
+	DBusMessage *reply;
+	DBusError error;
+	int mtype;
+
+	dbus_error_init (&error);
+	reply = dbus_pending_call_steal_reply (pending);
+	g_assert (reply);
+
+	mtype = dbus_message_get_type (reply);
+	switch (mtype) {
+	case DBUS_MESSAGE_TYPE_ERROR:
+		dbus_set_error_from_message (&error, reply);
+		nm_log_warn (LOGD_SUSPEND, "Inhibit() failed: %s", error.message ? error.message : "unknown");
+		break;
+	case DBUS_MESSAGE_TYPE_METHOD_RETURN:
+		if (!dbus_message_get_args (reply,
+		                            &error,
+		                            DBUS_TYPE_UNIX_FD, &self->inhibit_fd,
+		                            DBUS_TYPE_INVALID)) {
+			nm_log_warn (LOGD_SUSPEND, "Inhibit() reply parsing failed: %s",
+			                          error.message ? error.message : "unknown");
+			break;
+		}
+		nm_log_dbg (LOGD_SUSPEND, "Inhibitor fd is %d", self->inhibit_fd);
+		break;
+	default:
+		nm_log_warn (LOGD_SUSPEND, "Invalid Inhibit() reply message type %d", mtype);
+		break;
+	}
+
+	dbus_message_unref (reply);
+	dbus_error_free (&error);
+}
+
+static void
+take_inhibitor (NMSleepMonitor *self)
+{
+	NMDBusManager *dbus_mgr;
+	DBusConnection *bus;
+	DBusMessage *message = NULL;
+	DBusPendingCall *pending = NULL;
+	const char *arg_what = "sleep";
+	const char *arg_who = g_get_user_name ();
+	const char *arg_why = "inhibited";
+	const char *arg_mode = "delay";
+
+	g_assert (self->inhibit_fd == -1);
+
+	nm_log_dbg (LOGD_SUSPEND, "Taking systemd sleep inhibitor");
+
+	dbus_mgr = nm_dbus_manager_get ();
+	bus = nm_dbus_manager_get_dbus_connection (dbus_mgr);
+	g_assert (bus);
+	g_object_unref (dbus_mgr);
+
+	if (!(message = dbus_message_new_method_call (SD_NAME,
+	                                              SD_PATH,
+	                                              SD_INTERFACE,
+	                                              "Inhibit"))) {
+		nm_log_warn (LOGD_SUSPEND, "Unable to call Inhibit()");
+		return;
+	}
+	if (!dbus_message_append_args (message,
+	                               DBUS_TYPE_STRING, &arg_what,
+	                               DBUS_TYPE_STRING, &arg_who,
+	                               DBUS_TYPE_STRING, &arg_why,
+	                               DBUS_TYPE_STRING, &arg_mode,
+	                               DBUS_TYPE_INVALID)) {
+		nm_log_warn (LOGD_SUSPEND, "Unable to call Inhibit()");
+		goto done;
+	}
+
+	if (!dbus_connection_send_with_reply (bus, message, &pending, -1))
+		goto done;
+
+	if (!dbus_pending_call_set_notify (pending, inhibit_done, self, NULL)) {
+		dbus_pending_call_cancel (pending);
+		dbus_pending_call_unref (pending);
+	}
+
+done:
+	if (message)
+		dbus_message_unref (message);
+}
+
+static void
+signal_cb (DBusGProxy *proxy, gboolean about_to_suspend, gpointer data)
+{
+	NMSleepMonitor *self = data;
+
+	nm_log_dbg (LOGD_SUSPEND, "Received PrepareForSleep signal: %d", about_to_suspend);
+
+	if (about_to_suspend) {
+		g_signal_emit (self, signals[SLEEPING], 0);
+		drop_inhibitor (self);
+	} else {
+		take_inhibitor (self);
+		g_signal_emit (self, signals[RESUMING], 0);
+	}
+}
+
+static void
+sleep_setup (NMSleepMonitor *self)
+{
+	NMDBusManager *dbus_mgr;
+	DBusGConnection *bus;
+
+	dbus_mgr = nm_dbus_manager_get ();
+	bus = nm_dbus_manager_get_connection (dbus_mgr);
+	self->sd_proxy = dbus_g_proxy_new_for_name (bus, SD_NAME, SD_PATH, SD_INTERFACE);
+	g_object_unref (dbus_mgr);
+
+	if (self->sd_proxy) {
+		dbus_g_proxy_add_signal (self->sd_proxy, "PrepareForSleep", G_TYPE_BOOLEAN, G_TYPE_INVALID);
+		dbus_g_proxy_connect_signal (self->sd_proxy, "PrepareForSleep",
+		                             G_CALLBACK (signal_cb),
+		                             self, NULL);
+	} else
+		nm_log_warn (LOGD_SUSPEND, "could not initialize systemd-logind D-Bus proxy");
+}
+#endif  /* IS_GDBUS_UNIXFD_AVAILABLE */
+
+static void
+nm_sleep_monitor_init (NMSleepMonitor *self)
+{
+	self->inhibit_fd = -1;
+	sleep_setup (self);
 	take_inhibitor (self);
 }