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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 62859C433DF for ; Tue, 4 Aug 2020 23:38:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 42D1C20792 for ; Tue, 4 Aug 2020 23:38:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727083AbgHDXiI (ORCPT ); Tue, 4 Aug 2020 19:38:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57058 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727003AbgHDXiH (ORCPT ); Tue, 4 Aug 2020 19:38:07 -0400 X-Greylist: delayed 2107 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Tue, 04 Aug 2020 16:38:06 PDT Received: from pannekake.samfundet.no (pannekake.samfundet.no [IPv6:2001:67c:29f4::50]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 14FE1C06174A for ; Tue, 4 Aug 2020 16:38:06 -0700 (PDT) Received: from sesse by pannekake.samfundet.no with local (Exim 4.92) (envelope-from ) id 1k35xG-0000MS-OY; Wed, 05 Aug 2020 01:02:46 +0200 Date: Wed, 5 Aug 2020 01:02:46 +0200 From: "Steinar H. Gunderson" To: Vladimir Oltean Cc: Eric Dumazet , "Gaube, Marvin (THSE-TL1)" , Florian Fainelli , Woojung Huh , Microchip Linux Driver Support , "netdev@vger.kernel.org" Subject: Re: PROBLEM: (DSA/Microchip): 802.1Q-Header lost on KSZ9477-DSA ingress without bridge Message-ID: <20200804230246.nrllxp2k2bruckcp@sesse.net> References: <20200804142708.zjos3b6jvqjj7uas@skbuf> <20200804192933.pe32dhfkrlspdhot@skbuf> <20200804194333.iszq54mhrtcy3hs6@skbuf> <20200804212421.e2lztrrg4evuk6zd@skbuf> <20200804223952.je4yacy57vt5qjwk@skbuf> <20200804224430.qt4zc2vihz7zeks6@skbuf> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200804224430.qt4zc2vihz7zeks6@skbuf> X-Operating-System: Linux 5.8.0-rc1 on a x86_64 User-Agent: NeoMutt/20180716 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Aug 05, 2020 at 01:44:30AM +0300, Vladimir Oltean wrote: >>>> What bug? What repro? You just said you don't have any. >>> Ask Steinar ? >>> >> Hi Steinar, do you have a reproducer for the bug that Eric fixed in >> commit d4b812dea4a2 ("vlan: mask vlan prio bits")? > The Google email address from the original report bounces back. Adding > another address found by searching for your name on netdev. Yeah, I don't work at Google anymore, so sesse@google.com does not exist. (Hi, Eric! Hoping you're fine despite the pandemic.) By accident, I'm actually sitting right next to the router in question right now. But the setup has changed at least twice since 2013, and it doesn't use sit anymore since native IPv6 is where it's at. So no, I don't have a reproducer anymore. I also really cannot remember the details; I think maybe the outgoing sit device was for 6rd? And the priority tag was added by a fairly cheap Zyxel switch that might still be in the loop, but now there's tagged VLANs anyway... If you want to spend time to try to reproduce this with the old kernel (to verify you have a reproducer that you can use to test the bug with), this is probably what I'd test: Send untagged packets with 802.1p priority set (most cheap managed switches allow you to force that somehow, I believe; tcpdump -e will show an 802.1q tag with VLAN 0), try to route them into a sit tunnel, and see if they become corrupted or not. That's the only thing I can recommend, sorry. I hoard a lot of things, but reproducers for fixed bugs from 2013 at my parents' house isn't among them :-) /* Steinar */ -- Homepage: https://www.sesse.net/