core: fix bus initialization order

We currently start the bus manager only after the creation of a
NMManager because the NMManager is needed to handle set-property bus
calls. However, objects created by NMManager
(e.g. NMDnsSystemdResolved) need a bus connection and so their
initialization currently fail.

To fix this, split nm_dbus_manager_start() in two parts: first only
create the connection and acquire the bus.  After this step the
NMManager can be set up. In the second step, set NMManager as the
set-property handler and start exporting objects on the bus.

Fixes: 297d4985ab

src/main.c

@@ -225,7 +225,7 @@ int
 main (int argc, char *argv[])
 {
 	gboolean success = FALSE;
-	NMManager *manager;
+	NMManager *manager = NULL;
 	NMConfig *config;
 	GError *error = NULL;
 	gboolean wrote_pidfile = FALSE;
@@ -395,12 +395,13 @@ main (int argc, char *argv[])
 	                                                         NM_CONFIG_KEYFILE_KEY_MAIN_AUTH_POLKIT,
 	                                                         NM_CONFIG_DEFAULT_MAIN_AUTH_POLKIT_BOOL));
 
-	manager = nm_manager_setup ();
+	if (!nm_dbus_manager_acquire_bus (nm_dbus_manager_get ()))
+		goto done_no_manager;
 
-	if (!nm_dbus_manager_start (nm_dbus_manager_get (),
-	                            nm_manager_dbus_set_property_handle,
-	                            manager))
-		goto done;
+	manager = nm_manager_setup ();
+	nm_dbus_manager_start (nm_dbus_manager_get(),
+	                       nm_manager_dbus_set_property_handle,
+	                       manager);
 
 	nm_dispatcher_init ();
 
@@ -453,6 +454,7 @@ done:
 
 	nm_dns_manager_stop (nm_dns_manager_get ());
 
+done_no_manager:
 	if (global_opt.pidfile && wrote_pidfile)
 		unlink (global_opt.pidfile);
 

src/nm-dbus-manager.c

@@ -83,6 +83,7 @@ typedef struct {
 	GDBusConnection *connection;
 	GDBusProxy *proxy;
 	guint objmgr_registration_id;
+	gboolean started;
 } NMDBusManagerPrivate;
 
 struct _NMDBusManager {
@@ -930,6 +931,7 @@ _obj_register (NMDBusManager *self,
 
 	nm_assert (c_list_is_empty (&obj->internal.registration_lst_head));
 	nm_assert (priv->connection);
+	nm_assert (priv->started);
 
 	n_klasses = 0;
 	gtype = G_OBJECT_TYPE (obj);
@@ -1107,7 +1109,7 @@ _nm_dbus_manager_obj_export (NMDBusObject *obj)
 		nm_assert_not_reached ();
 	c_list_link_tail (&priv->objects_lst_head, &obj->internal.objects_lst);
 
-	if (priv->connection)
+	if (priv->connection && priv->started)
 		_obj_register (self, obj);
 }
 
@@ -1306,7 +1308,7 @@ _nm_dbus_manager_obj_emit_signal (NMDBusObject *obj,
 	self = obj->internal.bus_manager;
 	priv = NM_DBUS_MANAGER_GET_PRIVATE (self);
 
-	if (!priv->connection) {
+	if (!priv->connection || !priv->started) {
 		nm_g_variant_unref_floating (args);
 		return;
 	}
@@ -1453,10 +1455,28 @@ static const GDBusInterfaceInfo interface_info_objmgr = NM_DEFINE_GDBUS_INTERFAC
 
 /*****************************************************************************/
 
-gboolean
+void
 nm_dbus_manager_start (NMDBusManager *self,
                        NMDBusManagerSetPropertyHandler set_property_handler,
                        gpointer set_property_handler_data)
+{
+	NMDBusManagerPrivate *priv;
+	NMDBusObject *obj;
+
+	g_return_if_fail (NM_IS_DBUS_MANAGER (self));
+	priv = NM_DBUS_MANAGER_GET_PRIVATE (self);
+	g_return_if_fail (priv->connection);
+
+	priv->set_property_handler = set_property_handler;
+	priv->set_property_handler_data = set_property_handler_data;
+	priv->started = TRUE;
+
+	c_list_for_each_entry (obj, &priv->objects_lst_head, internal.objects_lst)
+		_obj_register (self, obj);
+}
+
+gboolean
+nm_dbus_manager_acquire_bus (NMDBusManager *self)
 {
 	NMDBusManagerPrivate *priv;
 	gs_free_error GError *error = NULL;
@@ -1465,17 +1485,11 @@ nm_dbus_manager_start (NMDBusManager *self,
 	gs_unref_object GDBusProxy *proxy = NULL;
 	guint32 result;
 	guint registration_id;
-	NMDBusObject *obj;
 
 	g_return_val_if_fail (NM_IS_DBUS_MANAGER (self), FALSE);
 
 	priv = NM_DBUS_MANAGER_GET_PRIVATE (self);
 
-	priv->set_property_handler = set_property_handler;
-	priv->set_property_handler_data = set_property_handler_data;
-
-	g_return_val_if_fail (!priv->connection, FALSE);
-
 	/* we will create the D-Bus connection and registering the name synchronously.
 	 * The reason why that is necessary is because:
 	 *  (1) if we are unable to create a D-Bus connection, it means D-Bus is not
@@ -1557,9 +1571,6 @@ nm_dbus_manager_start (NMDBusManager *self,
 
 	_LOGI ("acquired D-Bus service \"%s\"", NM_DBUS_SERVICE);
 
-	c_list_for_each_entry (obj, &priv->objects_lst_head, internal.objects_lst)
-		_obj_register (self, obj);
-
 	return TRUE;
 }
 

src/nm-dbus-manager.h

@@ -49,9 +49,11 @@ typedef void (*NMDBusManagerSetPropertyHandler) (NMDBusObject *obj,
                                                  GVariant *value,
                                                  gpointer user_data);
 
-gboolean nm_dbus_manager_start (NMDBusManager *self,
-                                NMDBusManagerSetPropertyHandler handler,
-                                gpointer handler_data);
+gboolean nm_dbus_manager_acquire_bus (NMDBusManager *self);
+
+void nm_dbus_manager_start (NMDBusManager *self,
+                            NMDBusManagerSetPropertyHandler set_property_handler,
+                            gpointer set_property_handler_data);
 
 GDBusConnection *nm_dbus_manager_get_connection (NMDBusManager *self);