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=-8.6 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,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 B4661C433DF for ; Fri, 9 Oct 2020 04:05:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7B55C2224B for ; Fri, 9 Oct 2020 04:05:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ZKhI1VxO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726690AbgJIEF5 (ORCPT ); Fri, 9 Oct 2020 00:05:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41702 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726365AbgJIEFt (ORCPT ); Fri, 9 Oct 2020 00:05:49 -0400 Received: from mail-ot1-x341.google.com (mail-ot1-x341.google.com [IPv6:2607:f8b0:4864:20::341]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D8902C0613D2; Thu, 8 Oct 2020 21:05:47 -0700 (PDT) Received: by mail-ot1-x341.google.com with SMTP id f37so7762094otf.12; Thu, 08 Oct 2020 21:05:47 -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=rKmOpxLKn+fUEFJJdu19a0RxfbC1QrKPlHniKalLJM8=; b=ZKhI1VxOZ8UmgnlvJBCR2ft7QBPGwgy+q/1ZxtsubVfT1yRuzeOonRm6Zf/K2SDOuk RpaQ6jgH/WOo2Dd+4Wnh96eGyr4GxEKOGJ5NMflTyQCNbzv6pjv2kZXkhPSi43v7zbm+ LjsPFDBxlRqXVmlLOr+vrP2Alvpv3ZCAaoaW3lEiirvy2J79CIcuI/TgO8VxfCUQH39P WB9eKZcuYD9kJjLlu2sTUmU6FEDC7lLijcLZ+KvBvW7Z5S4KSjbEGCoEAc/mBF/hAJxc 7cJ25Xz1+augKZ+j0zYxuQfi8Ls4ov5ifAcmWkffoGjD8cCNAL1pT4uLGUAzuXss7rVK rUgA== 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=rKmOpxLKn+fUEFJJdu19a0RxfbC1QrKPlHniKalLJM8=; b=F8jq5P6z+gVsD0kIwgs7Ay0C+zoUNrsW2oTuKko/i0URPfkNDpUATJ7Znt791R4+55 Ya4gSllncWXNOjHb6hlfu7r5B1zAlUl8lcTl/THOKrd6zYgFfYHJT+8ctKp1/nfrSuAy 7KPgePRQfchJWQiFgaeuTWUIReuF1UwvxmU9hhG2igcCNxvIA/frg0Bl0z7lCtNFMOCR qhcrZlAIhFMAErfXsJUEfatEBYlE78oKRbxxgH1Wd+MCfd/0D0DH63bvqqxPzzJBSvvR Nl7RvUbpqeUFV/4J5obmqa3MUsqKjdjcTufwFOxLnylDhe9oRM9JBZ/3MI5ckfBUtHwA +gng== X-Gm-Message-State: AOAM530VPJbxta//mi9W3P49QV8zIAQR8IHMuXdDfdlGo9baikgKUKuv DiOwtLp674zq3D7njk2pbXTcNkyKVgE= X-Google-Smtp-Source: ABdhPJx498pAuqlafcgDN61i5NNqbTLZF9PDK9gfPDOFzF1Vy58xzhNqzwIOZwdE59jVbRdWRFZ7kg== X-Received: by 2002:a9d:3aa:: with SMTP id f39mr7757117otf.29.1602216347227; Thu, 08 Oct 2020 21:05:47 -0700 (PDT) Received: from Davids-MBP.attlocal.net ([2600:1700:3eca:200:c514:e4f4:762:f7df]) by smtp.googlemail.com with ESMTPSA id y4sm319458oou.38.2020.10.08.21.05.45 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 08 Oct 2020 21:05:46 -0700 (PDT) Subject: Re: [PATCH bpf-next V3 2/6] bpf: bpf_fib_lookup return MTU value as output when looked up To: Jesper Dangaard Brouer , bpf@vger.kernel.org Cc: netdev@vger.kernel.org, Daniel Borkmann , Alexei Starovoitov , maze@google.com, lmb@cloudflare.com, shaun@tigera.io, Lorenzo Bianconi , marek@cloudflare.com, John Fastabend , Jakub Kicinski , eyal.birger@gmail.com References: <160216609656.882446.16642490462568561112.stgit@firesoul> <160216614748.882446.6805410687451779968.stgit@firesoul> From: David Ahern Message-ID: Date: Thu, 8 Oct 2020 21:05:44 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.12.1 MIME-Version: 1.0 In-Reply-To: <160216614748.882446.6805410687451779968.stgit@firesoul> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 10/8/20 7:09 AM, Jesper Dangaard Brouer wrote: > The BPF-helpers for FIB lookup (bpf_xdp_fib_lookup and bpf_skb_fib_lookup) > can perform MTU check and return BPF_FIB_LKUP_RET_FRAG_NEEDED. The BPF-prog > don't know the MTU value that caused this rejection. > > If the BPF-prog wants to implement PMTU (Path MTU Discovery) (rfc1191) it > need to know this MTU value for the ICMP packet. > > Patch change lookup and result struct bpf_fib_lookup, to contain this MTU > value as output via a union with 'tot_len' as this is the value used for > the MTU lookup. > > Signed-off-by: Jesper Dangaard Brouer > --- > include/uapi/linux/bpf.h | 11 +++++++++-- > net/core/filter.c | 17 ++++++++++++----- > tools/include/uapi/linux/bpf.h | 11 +++++++++-- > 3 files changed, 30 insertions(+), 9 deletions(-) > Reviewed-by: David Ahern