From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B165DC43219 for ; Fri, 26 Apr 2019 09:24:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8D2902077B for ; Fri, 26 Apr 2019 09:24:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726279AbfDZJY1 (ORCPT ); Fri, 26 Apr 2019 05:24:27 -0400 Received: from s3.sipsolutions.net ([144.76.43.62]:54102 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726169AbfDZJY0 (ORCPT ); Fri, 26 Apr 2019 05:24:26 -0400 Received: by sipsolutions.net with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1hJx5c-0007WZ-O9; Fri, 26 Apr 2019 11:24:16 +0200 Message-ID: <1dcb87486a96785e3b9e6f337392aa904d977a0d.camel@sipsolutions.net> Subject: Re: [PATCH net-next 0/3] make nla_nest_start() add NLA_F_NESTED flag From: Johannes Berg To: Michal Kubecek , "David S. Miller" Cc: "netdev@vger.kernel.org" , David Ahern , Jiri Pirko , Pablo Neira Ayuso , Jozsef Kadlecsik , Florian Westphal , "netfilter-devel@vger.kernel.org" , "linux-kernel@vger.kernel.org" Date: Fri, 26 Apr 2019 11:24:15 +0200 In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5 (3.28.5-2.fc28) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Fri, 2019-04-26 at 09:13 +0000, Michal Kubecek wrote: > Another observation was that even if NLA_F_NESTED flag was introduced in > 2007, only few netlink based interfaces set it in kernel generated messages > and even many recently added APIs omit it. That is unfortunate as without > the flag, message parsers not familiar with attribute semantics cannot > recognize nested attributes and do not see message structure; this affects > e.g. wireshark dissector or mnl_nlmsg_fprintf() from libmnl. Indeed. I wonder if we should also (start) enforcing that the userspace sender side sets this, if the policy is strict? johannes