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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 5EEFDC04E53 for ; Wed, 15 May 2019 15:43:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2E85320818 for ; Wed, 15 May 2019 15:43:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="gc70Lxz6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728427AbfEOPnf (ORCPT ); Wed, 15 May 2019 11:43:35 -0400 Received: from mail-pl1-f176.google.com ([209.85.214.176]:42692 "EHLO mail-pl1-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726467AbfEOPnf (ORCPT ); Wed, 15 May 2019 11:43:35 -0400 Received: by mail-pl1-f176.google.com with SMTP id x15so58446pln.9 for ; Wed, 15 May 2019 08:43:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=RqxWv6KRTQkR9bm4kJgLejCSRILBr5S/s6oUQe3FJXo=; b=gc70Lxz6rNjlvOpWduRQDojN9R7AfBniBPVFf3lGHvLRskXV05cIdmw/pfM0Ywym9R ometjdvc7xs7DQBI1cGYX7JUPVt9fc8k98AgsWrnXb+3lZzAsKQ0xQnrfaaKPsyfCEP3 wc5gqkB6TBCldKsJje2i9/MmGvoNN5okwW/cKRMXAjSGV1KPfEiC2ZMosqxFlso7fz+2 YJt7PEvyejGLAZacfuQMm30iHKrvQeeeHVUcir6oqYlwY7pvBMWiyWuTcD+HYViFpAv4 WT1BNvERgiqJefXJhMklYOzwlWZgt/w5JinHfuOc1vtU8+t+pORjrkh2CzX8BA57tD7Z Yddg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=RqxWv6KRTQkR9bm4kJgLejCSRILBr5S/s6oUQe3FJXo=; b=Hr9ojaEaMIi2UEMogtIVwg29ytNMiA5I3bqz/4lWNy5AYd/Nkec3ZIRIIWw07+XYA2 O5/9YCOSeOOOVprrcAe0nG55oSJEaisvsZtAfGKW70HtIwocS7Kh49wByN6GMO4mNFTQ B5sWUr8lTZ+Mlxg6pbxdvCc/WffWGUCa4e3RmY9N6rHkW5euyICSXxn+GZvssI5poqXu Fd90LUNHuIjVmUXmVFcOVEWtqw7BVw91SmsaJFhjRgz7ivBSsVC7ZBAe8B9xquHgE0ua s3JDXA1XmRkwRCaGVDyf6OS48noxadYWxHxImTcJ7sfr+abB0bLD2Pq6GYKWHpSJ4L5g /dOQ== X-Gm-Message-State: APjAAAUnuZI/1+NyH0Vd9VVMugU98/SfU5sesejl++Jwxqe3dRVtIjes M8fKwj/T2S2W4ceYHUsi5OLENgSS X-Google-Smtp-Source: APXvYqxCF+YbZ9+ZY3ONpah+J1FcTHzXbEBplKFOaj4nhaQbyd+JdKcfPRRe4JMUpTGvfA8Qoy5RFA== X-Received: by 2002:a17:902:201:: with SMTP id 1mr26636265plc.89.1557935014135; Wed, 15 May 2019 08:43:34 -0700 (PDT) Received: from ?IPv6:2601:282:800:fd80:81dc:8ee9:edb2:6ea? ([2601:282:800:fd80:81dc:8ee9:edb2:6ea]) by smtp.googlemail.com with ESMTPSA id t78sm7095257pfa.154.2019.05.15.08.43.32 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 15 May 2019 08:43:33 -0700 (PDT) Subject: Re: IPv6 PMTU discovery fails with source-specific routing To: Wei Wang , Stefano Brivio , Martin KaFai Lau Cc: Mikael Magnusson , Linux Kernel Network Developers References: <71e7331f-d528-430e-f880-e995ff53d362@lists.m7n.se> <2667a075-7a51-d1e0-c4e7-cf0d011784b9@gmail.com> <20190514163308.2f870f27@redhat.com> From: David Ahern Message-ID: Date: Wed, 15 May 2019 09:43:32 -0600 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 5/14/19 1:33 PM, Wei Wang wrote: > I think the bug is because when creating exceptions, src_addr is not > always set even though fib6_info is in the subtree. (because of > rt6_is_gw_or_nonexthop() check) > However, when looking up for exceptions, we always set src_addr to the > passed in flow->src_addr if fib6_info is in the subtree. That causes > the exception lookup to fail. > I will make it consistent. > However, I don't quite understand the following logic in ip6_rt_cache_alloc(): > if (!rt6_is_gw_or_nonexthop(ort)) { > if (ort->fib6_dst.plen != 128 && > ipv6_addr_equal(&ort->fib6_dst.addr, daddr)) > rt->rt6i_flags |= RTF_ANYCAST; > #ifdef CONFIG_IPV6_SUBTREES > if (rt->rt6i_src.plen && saddr) { > rt->rt6i_src.addr = *saddr; > rt->rt6i_src.plen = 128; > } > #endif > } > Why do we need to check that the route is not gateway and has next hop > for updating rt6i_src? I checked the git history and it seems this > part was there from very early on (with some refactor in between)... I can not make sense of that check either.