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 0B2FEC05027 for ; Wed, 1 Feb 2023 15:39:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231685AbjBAPjV (ORCPT ); Wed, 1 Feb 2023 10:39:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48864 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229546AbjBAPjU (ORCPT ); Wed, 1 Feb 2023 10:39:20 -0500 Received: from mail-io1-xd31.google.com (mail-io1-xd31.google.com [IPv6:2607:f8b0:4864:20::d31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D92EB234F9 for ; Wed, 1 Feb 2023 07:39:19 -0800 (PST) Received: by mail-io1-xd31.google.com with SMTP id y7so3617884iob.6 for ; Wed, 01 Feb 2023 07:39:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=McPXi0Wsw094zlljnWMxIPMSnerp8sLMWwxDGW8WaRQ=; b=eh8MTFL+5zP6T7KCvNAzkhSmeZ6EulhbLcZfRIs6PGdVCGxVqdyRJdlNgyhBf6PnHU oyAa5sn3Fq3Xh8PyMJqq2cB/NMMgYEMqjfCdRWSqPWzt8CiM3FEKEQlGyU4mfcAXptqz tZWdmjf5dgZ5ISC2lNcUtR8lYqw3+kG3YYXSq3ikYyWCV/t+NiN1NbxVuBSxQaH7f93+ /8lVDEHMxgFGw6g+yKjwGdzlBcvkwxFRPYnACdqiHrygTFIt4uePLev3CGhH0YPXsau1 wHiEbtYxuGdUj42vmRTsBt8w5dWkx3x4zZOUoLFMdKUjnHx84sin2W2JVcNN7WXClLDb vRvA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=McPXi0Wsw094zlljnWMxIPMSnerp8sLMWwxDGW8WaRQ=; b=Duv+aBWS23xMjCt1WJY+ZNvl0pZ6PRuvCbT/0wtX1LM9NhlJPw/thBJBZz9n1D4yrB nuc2f2xIi4/4E8+n4OAn1e6MIHtBgW+9pHbuJFdj7HEw+9kLYYm6hOd3VEZQkQhIOCMY 80UB+D7k79fH9Nkh8+yHYJRuMadNQD+EaQrbnPvGV8HfqCO2qK7VnRGlneieFvGrsIMR 59w2uQ/5Tkmw0Y8JqcjO9O+ZdMz/rCeFRyiTJFQP+ERZvGXbTU7o0iagBFDuVtl91cIG kIzNJAq7DSKTh5mknua+jZ5ifqVzjshwZrKCI9RfGPV8+1vHe0itzGQdkqUQeoPOX1z1 3Ahg== X-Gm-Message-State: AO0yUKX0bCINwHuBSAXrm3kehw6ux46gyv9UX3GUYZJ5Ut3RFRHxFNYh 1emMsuDXQ0GEZQa7+Dw1uBE= X-Google-Smtp-Source: AK7set+aCXAvpE/6yJJox2lvt0C8nLhJrmMEeRP3Iw02NdsCzB8KRpMg75saF8QqYVtNfxLwxYU3SQ== X-Received: by 2002:a5e:9804:0:b0:707:ad8d:c0ab with SMTP id s4-20020a5e9804000000b00707ad8dc0abmr1718566ioj.10.1675265959197; Wed, 01 Feb 2023 07:39:19 -0800 (PST) Received: from ?IPV6:2601:282:800:7ed0:1dfd:95ca:34d0:dedb? ([2601:282:800:7ed0:1dfd:95ca:34d0:dedb]) by smtp.googlemail.com with ESMTPSA id i1-20020a6bf401000000b00704608527d1sm5984597iog.37.2023.02.01.07.39.18 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 01 Feb 2023 07:39:18 -0800 (PST) Message-ID: <4445718f-85d6-5ae6-209f-b3e402d483fa@gmail.com> Date: Wed, 1 Feb 2023 08:39:17 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.6.1 Subject: Re: [PATCHv4 net-next 00/10] net: support ipv4 big tcp Content-Language: en-US To: Xin Long , network dev Cc: davem@davemloft.net, kuba@kernel.org, Eric Dumazet , Paolo Abeni , Hideaki YOSHIFUJI , Pravin B Shelar , Jamal Hadi Salim , Cong Wang , Jiri Pirko , Pablo Neira Ayuso , Florian Westphal , Marcelo Ricardo Leitner , Ilya Maximets , Aaron Conole , Roopa Prabhu , Nikolay Aleksandrov , Mahesh Bandewar , Paul Moore , Guillaume Nault References: From: David Ahern In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 1/28/23 8:58 AM, Xin Long wrote: > This is similar to the BIG TCP patchset added by Eric for IPv6: > > https://lwn.net/Articles/895398/ > > Different from IPv6, IPv4 tot_len is 16-bit long only, and IPv4 header > doesn't have exthdrs(options) for the BIG TCP packets' length. To make > it simple, as David and Paolo suggested, we set IPv4 tot_len to 0 to > indicate this might be a BIG TCP packet and use skb->len as the real > IPv4 total length. > > This will work safely, as all BIG TCP packets are GSO/GRO packets and > processed on the same host as they were created; There is no padding > in GSO/GRO packets, and skb->len - network_offset is exactly the IPv4 > packet total length; Also, before implementing the feature, all those > places that may get iph tot_len from BIG TCP packets are taken care > with some new APIs: > Thanks for working on this.