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=-6.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,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 23E1CC43457 for ; Thu, 15 Oct 2020 16:56:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B023E2225A for ; Thu, 15 Oct 2020 16:56:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="kw6E45Z8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731117AbgJOQ4o (ORCPT ); Thu, 15 Oct 2020 12:56:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51892 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730793AbgJOQ4o (ORCPT ); Thu, 15 Oct 2020 12:56:44 -0400 Received: from mail-pf1-x442.google.com (mail-pf1-x442.google.com [IPv6:2607:f8b0:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D8E2EC061755; Thu, 15 Oct 2020 09:56:43 -0700 (PDT) Received: by mail-pf1-x442.google.com with SMTP id c20so2370996pfr.8; Thu, 15 Oct 2020 09:56:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:autocrypt:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=c89SKpAIAopcmZmV7SsNNuT7Bom+CXMUjA+qRYu76JU=; b=kw6E45Z89QKMc4iYjf3Fv1g34Ff8dV8SLGS4kLU0J8JHIMtRtEaB2xveIpZxamON3x WnVHl3oqf6U1x6vlGe3NqHGOzQRLXQg0Q2iDJ7X7Q+bFaSL/+sUQnnxNFNWrq75DX0UR HjZDU8sLfeMnDAS6IbmLHD3fVnFg4Rh43RVyYgR0KZBXRXlSpxj1pDS8yxRoFC+rQZCm MV7LQghCwUUXyEHwfVWRWyXvIJ9BxRXFAA4zMc/8Yb0W+IyALvAPBbH+7KzDEvh+LYI+ VrtMTmJWp1k+NHJvuKlbWPm2CgZZ3U++9pJb96N4tdfWU9SiRFYOoiwSRF/XxswJ81j8 CfNg== 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:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=c89SKpAIAopcmZmV7SsNNuT7Bom+CXMUjA+qRYu76JU=; b=DuI5086WgXHBLUlS7iHxs+6nukynDt7OrIPzw+5Wt9qaM1KJ06fNnRVjutE/FC8zgJ LLBFd80ylNdXE0kQEvNsX6tpfdF4l+5L1CcNB7ybfqbmq/tFraRhrdVWLUrmMapvnE4G ARlMhdA/5sGGwlBC34ddsPVQ/6RTp5MW5MDkVVwboTh3MF6VmGSwd587Ynq8hIurc/Gy pVG4xIksEiPUhIXTir3bNVeQcDTlTHdWjgfXayyzI4eKyzOr4HGo46oFP78qkElf1jjU W3mPUTGfN2HYEzxnWyqR4XX4pOomSVkSZ7LwIIEx+Zx3hL0bu+mzsim0HGHYfL4LCIEf blog== X-Gm-Message-State: AOAM530H+KfVXYPIm2Z6uRk3DTjrnH44x48Bl6l8SNqOfVFToEt5JP8j NmzpwiVYMa+MnCry5zwQJIAsnN3z6RY= X-Google-Smtp-Source: ABdhPJzfJxXTGh6o99eOzJXj/39hSGmWbA8bcG2+5hS9ydk+vUZwE9jh2qSHX1yZFxo4EDep+ew6QQ== X-Received: by 2002:a63:1d4b:: with SMTP id d11mr3963226pgm.31.1602781002859; Thu, 15 Oct 2020 09:56:42 -0700 (PDT) Received: from [10.67.48.230] ([192.19.223.252]) by smtp.googlemail.com with ESMTPSA id w12sm3953021pfu.53.2020.10.15.09.56.41 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 15 Oct 2020 09:56:42 -0700 (PDT) Subject: Re: [PATCH net-next] net: ptp: get rid of IPV4_HLEN() and OFF_IHL macros To: Richard Cochran , Christian Eggers Cc: "David S . Miller" , Jakub Kicinski , Krzysztof Halasa , Vishal Kulkarni , netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <20201014115805.23905-1-ceggers@arri.de> <20201015033648.GA24901@hoboy> From: Florian Fainelli Autocrypt: addr=f.fainelli@gmail.com; prefer-encrypt=mutual; keydata= mQGiBEjPuBIRBACW9MxSJU9fvEOCTnRNqG/13rAGsj+vJqontvoDSNxRgmafP8d3nesnqPyR xGlkaOSDuu09rxuW+69Y2f1TzjFuGpBk4ysWOR85O2Nx8AJ6fYGCoeTbovrNlGT1M9obSFGQ X3IzRnWoqlfudjTO5TKoqkbOgpYqIo5n1QbEjCCwCwCg3DOH/4ug2AUUlcIT9/l3pGvoRJ0E AICDzi3l7pmC5IWn2n1mvP5247urtHFs/uusE827DDj3K8Upn2vYiOFMBhGsxAk6YKV6IP0d ZdWX6fqkJJlu9cSDvWtO1hXeHIfQIE/xcqvlRH783KrihLcsmnBqOiS6rJDO2x1eAgC8meAX SAgsrBhcgGl2Rl5gh/jkeA5ykwbxA/9u1eEuL70Qzt5APJmqVXR+kWvrqdBVPoUNy/tQ8mYc nzJJ63ng3tHhnwHXZOu8hL4nqwlYHRa9eeglXYhBqja4ZvIvCEqSmEukfivk+DlIgVoOAJbh qIWgvr3SIEuR6ayY3f5j0f2ejUMYlYYnKdiHXFlF9uXm1ELrb0YX4GMHz7QnRmxvcmlhbiBG YWluZWxsaSA8Zi5mYWluZWxsaUBnbWFpbC5jb20+iGYEExECACYCGyMGCwkIBwMCBBUCCAME FgIDAQIeAQIXgAUCVF/S8QUJHlwd3wAKCRBhV5kVtWN2DvCVAJ4u4/bPF4P3jxb4qEY8I2gS 6hG0gACffNWlqJ2T4wSSn+3o7CCZNd7SLSC5BA0ESM+4EhAQAL/o09boR9D3Vk1Tt7+gpYr3 WQ6hgYVON905q2ndEoA2J0dQxJNRw3snabHDDzQBAcqOvdi7YidfBVdKi0wxHhSuRBfuOppu pdXkb7zxuPQuSveCLqqZWRQ+Cc2QgF7SBqgznbe6Ngout5qXY5Dcagk9LqFNGhJQzUGHAsIs hap1f0B1PoUyUNeEInV98D8Xd/edM3mhO9nRpUXRK9Bvt4iEZUXGuVtZLT52nK6Wv2EZ1TiT OiqZlf1P+vxYLBx9eKmabPdm3yjalhY8yr1S1vL0gSA/C6W1o/TowdieF1rWN/MYHlkpyj9c Rpc281gAO0AP3V1G00YzBEdYyi0gaJbCEQnq8Vz1vDXFxHzyhgGz7umBsVKmYwZgA8DrrB0M oaP35wuGR3RJcaG30AnJpEDkBYHznI2apxdcuTPOHZyEilIRrBGzDwGtAhldzlBoBwE3Z3MY 31TOpACu1ZpNOMysZ6xiE35pWkwc0KYm4hJA5GFfmWSN6DniimW3pmdDIiw4Ifcx8b3mFrRO BbDIW13E51j9RjbO/nAaK9ndZ5LRO1B/8Fwat7bLzmsCiEXOJY7NNpIEpkoNoEUfCcZwmLrU +eOTPzaF6drw6ayewEi5yzPg3TAT6FV3oBsNg3xlwU0gPK3v6gYPX5w9+ovPZ1/qqNfOrbsE FRuiSVsZQ5s3AAMFD/9XjlnnVDh9GX/r/6hjmr4U9tEsM+VQXaVXqZuHKaSmojOLUCP/YVQo 7IiYaNssCS4FCPe4yrL4FJJfJAsbeyDykMN7wAnBcOkbZ9BPJPNCbqU6dowLOiy8AuTYQ48m vIyQ4Ijnb6GTrtxIUDQeOBNuQC/gyyx3nbL/lVlHbxr4tb6YkhkO6shjXhQh7nQb33FjGO4P WU11Nr9i/qoV8QCo12MQEo244RRA6VMud06y/E449rWZFSTwGqb0FS0seTcYNvxt8PB2izX+ HZA8SL54j479ubxhfuoTu5nXdtFYFj5Lj5x34LKPx7MpgAmj0H7SDhpFWF2FzcC1bjiW9mjW HaKaX23Awt97AqQZXegbfkJwX2Y53ufq8Np3e1542lh3/mpiGSilCsaTahEGrHK+lIusl6mz Joil+u3k01ofvJMK0ZdzGUZ/aPMZ16LofjFA+MNxWrZFrkYmiGdv+LG45zSlZyIvzSiG2lKy kuVag+IijCIom78P9jRtB1q1Q5lwZp2TLAJlz92DmFwBg1hyFzwDADjZ2nrDxKUiybXIgZp9 aU2d++ptEGCVJOfEW4qpWCCLPbOT7XBr+g/4H3qWbs3j/cDDq7LuVYIe+wchy/iXEJaQVeTC y5arMQorqTFWlEOgRA8OP47L9knl9i4xuR0euV6DChDrguup2aJVU4hPBBgRAgAPAhsMBQJU X9LxBQkeXB3fAAoJEGFXmRW1Y3YOj4UAn3nrFLPZekMeqX5aD/aq/dsbXSfyAKC45Go0YyxV HGuUuzv+GKZ6nsysJ7kCDQRXG8fwARAA6q/pqBi5PjHcOAUgk2/2LR5LjjesK50bCaD4JuNc YDhFR7Vs108diBtsho3w8WRd9viOqDrhLJTroVckkk74OY8r+3t1E0Dd4wHWHQZsAeUvOwDM PQMqTUBFuMi6ydzTZpFA2wBR9x6ofl8Ax+zaGBcFrRlQnhsuXLnM1uuvS39+pmzIjasZBP2H UPk5ifigXcpelKmj6iskP3c8QN6x6GjUSmYx+xUfs/GNVSU1XOZn61wgPDbgINJd/THGdqiO iJxCLuTMqlSsmh1+E1dSdfYkCb93R/0ZHvMKWlAx7MnaFgBfsG8FqNtZu3PCLfizyVYYjXbV WO1A23riZKqwrSJAATo5iTS65BuYxrFsFNPrf7TitM8E76BEBZk0OZBvZxMuOs6Z1qI8YKVK UrHVGFq3NbuPWCdRul9SX3VfOunr9Gv0GABnJ0ET+K7nspax0xqq7zgnM71QEaiaH17IFYGS sG34V7Wo3vyQzsk7qLf9Ajno0DhJ+VX43g8+AjxOMNVrGCt9RNXSBVpyv2AMTlWCdJ5KI6V4 KEzWM4HJm7QlNKE6RPoBxJVbSQLPd9St3h7mxLcne4l7NK9eNgNnneT7QZL8fL//s9K8Ns1W t60uQNYvbhKDG7+/yLcmJgjF74XkGvxCmTA1rW2bsUriM533nG9gAOUFQjURkwI8jvMAEQEA AYkCaAQYEQIACQUCVxvH8AIbAgIpCRBhV5kVtWN2DsFdIAQZAQIABgUCVxvH8AAKCRCH0Jac RAcHBIkHD/9nmfog7X2ZXMzL9ktT++7x+W/QBrSTCTmq8PK+69+INN1ZDOrY8uz6htfTLV9+ e2W6G8/7zIvODuHk7r+yQ585XbplgP0V5Xc8iBHdBgXbqnY5zBrcH+Q/oQ2STalEvaGHqNoD UGyLQ/fiKoLZTPMur57Fy1c9rTuKiSdMgnT0FPfWVDfpR2Ds0gpqWePlRuRGOoCln5GnREA/ 2MW2rWf+CO9kbIR+66j8b4RUJqIK3dWn9xbENh/aqxfonGTCZQ2zC4sLd25DQA4w1itPo+f5 V/SQxuhnlQkTOCdJ7b/mby/pNRz1lsLkjnXueLILj7gNjwTabZXYtL16z24qkDTI1x3g98R/ xunb3/fQwR8FY5/zRvXJq5us/nLvIvOmVwZFkwXc+AF+LSIajqQz9XbXeIP/BDjlBNXRZNdo dVuSU51ENcMcilPr2EUnqEAqeczsCGpnvRCLfVQeSZr2L9N4svNhhfPOEscYhhpHTh0VPyxI pPBNKq+byuYPMyk3nj814NKhImK0O4gTyCK9b+gZAVvQcYAXvSouCnTZeJRrNHJFTgTgu6E0 caxTGgc5zzQHeX67eMzrGomG3ZnIxmd1sAbgvJUDaD2GrYlulfwGWwWyTNbWRvMighVdPkSF 6XFgQaosWxkV0OELLy2N485YrTr2Uq64VKyxpncLh50e2RnyAJ9Za0Dx0yyp44iD1OvHtkEI M5kY0ACeNhCZJvZ5g4C2Lc9fcTHu8jxmEkI= Message-ID: <939828b0-846c-9e10-df31-afcb77b1150a@gmail.com> Date: Thu, 15 Oct 2020 09:56:41 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201015033648.GA24901@hoboy> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 10/14/20 8:36 PM, Richard Cochran wrote: > On Wed, Oct 14, 2020 at 01:58:05PM +0200, Christian Eggers wrote: >> Both macros are already marked for removal. > > I'm not sure what Daniel Borkmann meant by that comment, but ... > >> switch (type & PTP_CLASS_PMASK) { >> case PTP_CLASS_IPV4: >> - ptr += IPV4_HLEN(ptr) + UDP_HLEN; >> + ptr += (((struct iphdr *)ptr)->ihl << 2) + UDP_HLEN; > > to my eyes > > IPV4_HLEN(ptr) > > is way more readable than > > (((struct iphdr *)ptr)->ihl << 2) > > and this > > (struct udphdr *)((char *)ih + (ih->ihl << 2)) > > is really baroque. > > I don't see any improvement here. Having recently helped someone with a bug that involved using IPV4_HLEN() instead of ip_hdr() in a driver's transmit path (so with the transport header correctly set), it would probably help if we could make IPV4_HLEN()'s semantics clearer with converting it to a static inline function and put asserts in there about what the transport and MAC header positions should be. At the very least, creating a new function, like this maybe in include/linux/ip.h might help: static inline u8 __ip_hdr_len(const struct sk_buff *skb) { const struct iphdr *ip_hdr = (const struct iphdr *)(skb->data); return ip_hdr->ihl << 2; } -- Florian