kdbus: check policy first, only then open kdbus

A process shouldn't hold an open kdbus descriptor, if according to
security policy this process has no rights to open the bus at all.
Corrected error message and code to be consistent with dbus-daemon.

Change-Id: I8c138438a21736f9241addc9ed5a616f6be19442

1 files changed, 22 insertions, 25 deletions

diff --git a/dbus/dbus-transport-kdbus.c b/dbus/dbus-transport-kdbus.c
index e8b333ad..73ebc45a 100755
--- a/dbus/dbus-transport-kdbus.c
+++ b/dbus/dbus-transport-kdbus.c
@@ -4288,20 +4288,6 @@ new_kdbus_transport (kdbus_t          *kdbus,
   return NULL;
 }
 
-static dbus_bool_t
-initialize_policies (DBusTransportKdbus *transport, const char *path)
-{
-  dbus_bool_t result = TRUE;
-
-#ifdef LIBDBUSPOLICY
-  transport->policy = dbuspolicy1_init (path);
-  if (NULL == transport->policy)
-    result = FALSE;
-#endif
-
-  return result;
-}
-
 /**
  * Connects to kdbus, creates and sets-up transport.
  *
@@ -4318,6 +4304,9 @@ _dbus_transport_new_for_kdbus (const char *path,
   DBusTransportKdbus *transport;
   DBusString address;
   kdbus_t *kdbus;
+#ifdef LIBDBUSPOLICY
+  void *policy;
+#endif
 
 #ifdef DBUS_ENABLE_VERBOSE_MODE
   const char *dbgenv = _dbus_getenv ("G_DBUS_DEBUG");
@@ -4351,6 +4340,17 @@ _dbus_transport_new_for_kdbus (const char *path,
       goto failed_0;
     }
 
+#ifdef LIBDBUSPOLICY
+  policy = dbuspolicy1_init (path);
+  if (NULL == policy)
+    {
+      dbus_set_error (error,
+                      DBUS_ERROR_NO_REPLY,
+                      "Did not receive a reply. Possible causes include: couldn't load dbus policy for kdbus transport or the message bus security policy blocked the reply.");
+      goto failed_0_with_kdbus;
+    }
+#endif
+
   ret = _kdbus_open (kdbus, path);
   if (ret < 0)
     {
@@ -4359,7 +4359,7 @@ _dbus_transport_new_for_kdbus (const char *path,
                       "Failed to open file descriptor: %s: %s",
                       path,
                       _dbus_strerror (-ret));
-      goto failed_0_with_kdbus;
+      goto failed_0_with_kdbus_and_policy;
     }
 
   _dbus_verbose ("Successfully connected to kdbus bus %s\n", path);
@@ -4370,16 +4370,9 @@ _dbus_transport_new_for_kdbus (const char *path,
       dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
       goto failed_1;
     }
-
-  if (!initialize_policies (transport, path))
-    {
-      dbus_set_error (error,
-                      DBUS_ERROR_FAILED,
-                      "Can't load dbus policy for kdbus transport");
-      _kdbus_close (kdbus);
-      transport_finalize ((DBusTransport*)transport);
-      transport = NULL;
-    }
+#ifdef LIBDBUSPOLICY
+  transport->policy = policy;
+#endif
 
   _dbus_string_free (&address);
 
@@ -4387,6 +4380,10 @@ _dbus_transport_new_for_kdbus (const char *path,
 
 failed_1:
   _kdbus_close (kdbus);
+failed_0_with_kdbus_and_policy:
+#ifdef LIBDBUSPOLICY
+  dbuspolicy1_free (policy);
+#endif
 failed_0_with_kdbus:
   _kdbus_free (kdbus);
 failed_0: