+ /*
+ * Disallow changing the interface to have the same path name
+ * as other interface
+ */
+ if_index = mhash_get (&vum->if_index_by_sock_name, (void *) sock_filename);
+ if (if_index && (*if_index != vui->if_index))
+ return VNET_API_ERROR_IF_ALREADY_EXISTS;
+