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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1C735C433F5 for ; Wed, 2 Feb 2022 21:10:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347441AbiBBVKR (ORCPT ); Wed, 2 Feb 2022 16:10:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49870 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347418AbiBBVKR (ORCPT ); Wed, 2 Feb 2022 16:10:17 -0500 Received: from mail-io1-xd2e.google.com (mail-io1-xd2e.google.com [IPv6:2607:f8b0:4864:20::d2e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1FD41C061714 for ; Wed, 2 Feb 2022 13:10:17 -0800 (PST) Received: by mail-io1-xd2e.google.com with SMTP id c188so690249iof.6 for ; Wed, 02 Feb 2022 13:10:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=google; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=3t75659HzPBq87wFRBg/hKoyMSaZFRX143OrPCse9fA=; b=FetyPppDYU956R83igKID+s65jxrPkNP9iHqHnYDnzitra0C3DnelZ7GXPiKprrgb0 XJyqkDaqbxlDVvpMEDWTdcBGD2368gDxM7OkZK42TJkWP/3pGxxp/pt6a2w2cOnaVQ2u +h9uqANz/+hYCmJUiwEHvljOoHS/HcPpgt8Is= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; 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=3t75659HzPBq87wFRBg/hKoyMSaZFRX143OrPCse9fA=; b=i0R2ukLsycIk4q5cdxOp0WiaXnuqzactg5+OLqiaPdqEnvXnHrMUZB0WvsnfRPnKMb 4lIW4DTzbOPUv1aOZd7JIsAEnwR//vUCszG73nSfOxoH/fQa7qyg3ZJbhclHIO6lnCCN bSskU1gr6ciSLyyBVKETKKTN0vSYsB/kMvjJxTg3UJtd1BDhi2KJq3x/l8dGVtbvoE6R hgBGf4XossmgyU2uT63vEQG26TtYZFpGRzBwBmJf+qMkChQ8/m/8gWhNHOKzRYFdeIyn UcJRHXnPuuok06d1hD+TgrbfyXmXrPeQd2NfryvJjhR7KM3/NbyEN+JNaWBUMVRBcPzS xDyw== X-Gm-Message-State: AOAM5314uAocWtpf0UbjmqZ9T6/6EzdHMp6T99cj9xrfQG9Xp3RVhr1S p7BRzGex1exFHakaofK0hvtb2fqtTd60uw== X-Google-Smtp-Source: ABdhPJzZ/U40pLxN1F7mOBlTvI7e1PiFI3vnLg2IOzGJpegL6dPnnCWv9ezVVSNzL/N6gkrjlBskXQ== X-Received: by 2002:a05:6638:3888:: with SMTP id b8mr15850151jav.250.1643836216416; Wed, 02 Feb 2022 13:10:16 -0800 (PST) Received: from [192.168.1.128] ([71.205.29.0]) by smtp.gmail.com with ESMTPSA id c3sm24565292iow.28.2022.02.02.13.10.15 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 02 Feb 2022 13:10:16 -0800 (PST) Subject: Re: [PATCH net-next] selftests: fib offload: use sensible tos values To: Guillaume Nault Cc: David Miller , Jakub Kicinski , netdev@vger.kernel.org, Shuah Khan , linux-kselftest@vger.kernel.org, Ido Schimmel , Jiri Pirko , Shuah Khan References: <5e43b343720360a1c0e4f5947d9e917b26f30fbf.1643826556.git.gnault@redhat.com> <54a7071e-71ad-0c7d-ccc4-0f85dbe1e077@linuxfoundation.org> <20220202201614.GB15826@pc-4.home> From: Shuah Khan Message-ID: Date: Wed, 2 Feb 2022 14:10:15 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20220202201614.GB15826@pc-4.home> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2/2/22 1:16 PM, Guillaume Nault wrote: > On Wed, Feb 02, 2022 at 12:46:10PM -0700, Shuah Khan wrote: >> On 2/2/22 11:30 AM, Guillaume Nault wrote: >>> Although both iproute2 and the kernel accept 1 and 2 as tos values for >>> new routes, those are invalid. These values only set ECN bits, which >>> are ignored during IPv4 fib lookups. Therefore, no packet can actually >>> match such routes. This selftest therefore only succeeds because it >>> doesn't verify that the new routes do actually work in practice (it >>> just checks if the routes are offloaded or not). >>> >>> It makes more sense to use tos values that don't conflict with ECN. >>> This way, the selftest won't be affected if we later decide to warn or >>> even reject invalid tos configurations for new routes. >> >> Wouldn't it make sense to leave these invalid values in the test though. >> Removing these makes this test out of sync withe kernel. > > Do you mean keeping the test as is and only modify it when (if) we > decide to reject such invalid values? This is for sure. Remove the invalid values in sync with the kernel code. > Or to write two versions of the > test, one with invalid values, the other with correct ones? > This one makes sense if it adds value in testing to make sure we continue to reject invalid values. > I don't get what keeping a test with the invalid values could bring us. > It's confusing for the reader, and might break in the future. This > patch makes the test future proof, without altering its intent and code > coverage. It still works on current (and past) kernels, so I don't see > what this patch could make out of sync. > If kernel still accepts these values, then the test is valid as long as kernel still doesn't flag these values as invalid. I might be missing something. Don't you want to test with invalid values so make sure they are indeed rejected? thanks, -- Shuah