libnm: add nm_vpn_service_plugin_shutdown() API

Otherwise, the only way to disconnect the NMVpnServicePlugin
instance is by completely unrefing it. However, often it is
not so easy to ensure that nobody else is still keeping the
instance alive, after the point where we no longer want to
handle D-Bus requests. nm_vpn_service_plugin_shutdown() to the
rescue.

libnm/libnm.ver

@@ -1352,4 +1352,5 @@ global:
 	nm_setting_ip_tunnel_get_flags;
 	nm_setting_vpn_get_data_keys;
 	nm_setting_vpn_get_secret_keys;
+	nm_vpn_service_plugin_shutdown;
 } libnm_1_10_0;

libnm/nm-vpn-service-plugin.c

@@ -151,7 +151,8 @@ nm_vpn_service_plugin_set_state (NMVpnServicePlugin *plugin,
 	if (priv->state != state) {
 		priv->state = state;
 		g_signal_emit (plugin, signals[STATE_CHANGED], 0, state);
-		nmdbus_vpn_plugin_emit_state_changed (priv->dbus_vpn_service_plugin, state);
+		if (priv->dbus_vpn_service_plugin)
+			nmdbus_vpn_plugin_emit_state_changed (priv->dbus_vpn_service_plugin, state);
 	}
 }
 
@@ -166,7 +167,8 @@ nm_vpn_service_plugin_set_login_banner (NMVpnServicePlugin *plugin,
 
 	priv = NM_VPN_SERVICE_PLUGIN_GET_PRIVATE (plugin);
 	g_signal_emit (plugin, signals[LOGIN_BANNER], 0, banner);
-	nmdbus_vpn_plugin_emit_login_banner (priv->dbus_vpn_service_plugin, banner);
+	if (priv->dbus_vpn_service_plugin)
+		nmdbus_vpn_plugin_emit_login_banner (priv->dbus_vpn_service_plugin, banner);
 }
 
 static void
@@ -176,7 +178,8 @@ _emit_failure (NMVpnServicePlugin *plugin,
 	NMVpnServicePluginPrivate *priv = NM_VPN_SERVICE_PLUGIN_GET_PRIVATE (plugin);
 
 	g_signal_emit (plugin, signals[FAILURE], 0, reason);
-	nmdbus_vpn_plugin_emit_failure (priv->dbus_vpn_service_plugin, reason);
+	if (priv->dbus_vpn_service_plugin)
+		nmdbus_vpn_plugin_emit_failure (priv->dbus_vpn_service_plugin, reason);
 }
 
 void
@@ -241,6 +244,51 @@ nm_vpn_service_plugin_emit_quit (NMVpnServicePlugin *plugin)
 	g_signal_emit (plugin, signals[QUIT], 0);
 }
 
+/**
+ * nm_vpn_service_plugin_shutdown:
+ * @plugin: the #NMVpnServicePlugin instance
+ *
+ * Shutdown the @plugin and disconnect from D-Bus. After this,
+ * the plugin instance is dead and should no longer be used.
+ * It ensures to get no more requests from D-Bus. In principle,
+ * you don't need to shutdown the plugin, disposing the instance
+ * has the same effect. However, this gives a way to deactivate
+ * the plugin before giving up the last reference.
+ *
+ * Since: 1.12
+ */
+void
+nm_vpn_service_plugin_shutdown (NMVpnServicePlugin *plugin)
+{
+	NMVpnServicePluginPrivate *priv;
+	NMVpnServiceState state;
+	GError *error = NULL;
+
+	g_return_if_fail (NM_IS_VPN_SERVICE_PLUGIN (plugin));
+
+	priv = NM_VPN_SERVICE_PLUGIN_GET_PRIVATE (plugin);
+
+	nm_clear_g_source (&priv->fail_stop_id);
+	nm_clear_g_source (&priv->quit_timer);
+	nm_clear_g_source (&priv->connect_timer);
+
+	state = nm_vpn_service_plugin_get_state (plugin);
+	if (state == NM_VPN_SERVICE_STATE_STARTED ||
+	    state == NM_VPN_SERVICE_STATE_STARTING) {
+		nm_vpn_service_plugin_disconnect (plugin, &error);
+
+		if (error) {
+			g_warning ("Error disconnecting VPN connection: %s", error->message);
+			g_error_free (error);
+		}
+	}
+
+	if (priv->dbus_vpn_service_plugin) {
+		g_dbus_interface_skeleton_unexport (G_DBUS_INTERFACE_SKELETON (priv->dbus_vpn_service_plugin));
+		g_clear_object (&priv->dbus_vpn_service_plugin);
+	}
+}
+
 static gboolean
 connect_timer_expired (gpointer data)
 {
@@ -336,7 +384,8 @@ nm_vpn_service_plugin_set_config (NMVpnServicePlugin *plugin,
 	                                    G_VARIANT_TYPE ("u"));
 
 	g_signal_emit (plugin, signals[CONFIG], 0, config);
-	nmdbus_vpn_plugin_emit_config (priv->dbus_vpn_service_plugin, config);
+	if (priv->dbus_vpn_service_plugin)
+		nmdbus_vpn_plugin_emit_config (priv->dbus_vpn_service_plugin, config);
 }
 
 void
@@ -387,7 +436,8 @@ nm_vpn_service_plugin_set_ip4_config (NMVpnServicePlugin *plugin,
 	combined_config = g_variant_builder_end (&builder);
 	g_variant_ref_sink (combined_config);
 	g_signal_emit (plugin, signals[IP4_CONFIG], 0, combined_config);
-	nmdbus_vpn_plugin_emit_ip4_config (priv->dbus_vpn_service_plugin, combined_config);
+	if (priv->dbus_vpn_service_plugin)
+		nmdbus_vpn_plugin_emit_ip4_config (priv->dbus_vpn_service_plugin, combined_config);
 	g_variant_unref (combined_config);
 
 	if (   priv->has_ip4 == priv->got_ip4
@@ -408,7 +458,8 @@ nm_vpn_service_plugin_set_ip6_config (NMVpnServicePlugin *plugin,
 
 	priv->got_ip6 = TRUE;
 	g_signal_emit (plugin, signals[IP6_CONFIG], 0, ip6_config);
-	nmdbus_vpn_plugin_emit_ip6_config (priv->dbus_vpn_service_plugin, ip6_config);
+	if (priv->dbus_vpn_service_plugin)
+		nmdbus_vpn_plugin_emit_ip6_config (priv->dbus_vpn_service_plugin, ip6_config);
 
 	g_variant_unref (ip6_config);
 
@@ -698,7 +749,8 @@ nm_vpn_service_plugin_secrets_required (NMVpnServicePlugin *plugin,
 	nm_clear_g_source (&priv->connect_timer);
 
 	g_signal_emit (plugin, signals[SECRETS_REQUIRED], 0, message, hints);
-	nmdbus_vpn_plugin_emit_secrets_required (priv->dbus_vpn_service_plugin, message, hints);
+	if (priv->dbus_vpn_service_plugin)
+		nmdbus_vpn_plugin_emit_secrets_required (priv->dbus_vpn_service_plugin, message, hints);
 }
 
 /*****************************************************************************/
@@ -1026,7 +1078,7 @@ set_property (GObject *object, guint prop_id,
 		break;
 	case PROP_STATE:
 		nm_vpn_service_plugin_set_state (NM_VPN_SERVICE_PLUGIN (object),
-		                             (NMVpnServiceState) g_value_get_enum (value));
+		                                 (NMVpnServiceState) g_value_get_enum (value));
 		break;
 	default:
 		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
@@ -1059,31 +1111,7 @@ get_property (GObject *object, guint prop_id,
 static void
 dispose (GObject *object)
 {
-	NMVpnServicePlugin *plugin = NM_VPN_SERVICE_PLUGIN (object);
-	NMVpnServicePluginPrivate *priv = NM_VPN_SERVICE_PLUGIN_GET_PRIVATE (plugin);
-	NMVpnServiceState state;
-	GError *err = NULL;
-
-	nm_clear_g_source (&priv->fail_stop_id);
-	nm_clear_g_source (&priv->quit_timer);
-	nm_clear_g_source (&priv->connect_timer);
-
-	state = nm_vpn_service_plugin_get_state (plugin);
-
-	if (state == NM_VPN_SERVICE_STATE_STARTED ||
-	    state == NM_VPN_SERVICE_STATE_STARTING)
-		nm_vpn_service_plugin_disconnect (plugin, &err);
-
-	if (err) {
-		g_warning ("Error disconnecting VPN connection: %s", err->message);
-		g_error_free (err);
-	}
-
-	if (priv->dbus_vpn_service_plugin) {
-		g_dbus_interface_skeleton_unexport (G_DBUS_INTERFACE_SKELETON (priv->dbus_vpn_service_plugin));
-		g_clear_object (&priv->dbus_vpn_service_plugin);
-	}
-
+	nm_vpn_service_plugin_shutdown (NM_VPN_SERVICE_PLUGIN (object));
 	G_OBJECT_CLASS (nm_vpn_service_plugin_parent_class)->dispose (object);
 }
 

libnm/nm-vpn-service-plugin.h

@@ -150,6 +150,9 @@ NM_AVAILABLE_IN_1_2
 gboolean           nm_vpn_service_plugin_disconnect     (NMVpnServicePlugin *plugin,
                                                          GError **err);
 
+NM_AVAILABLE_IN_1_12
+void               nm_vpn_service_plugin_shutdown (NMVpnServicePlugin *plugin);
+
 /* Utility functions */
 
 NM_AVAILABLE_IN_1_2