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=-8.4 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,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 11410C388F7 for ; Sat, 31 Oct 2020 15:52:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C95F9206B6 for ; Sat, 31 Oct 2020 15:52:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="guuU9AcL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728068AbgJaPwl (ORCPT ); Sat, 31 Oct 2020 11:52:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43956 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727867AbgJaPwk (ORCPT ); Sat, 31 Oct 2020 11:52:40 -0400 Received: from mail-il1-x141.google.com (mail-il1-x141.google.com [IPv6:2607:f8b0:4864:20::141]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7E888C0617A6; Sat, 31 Oct 2020 08:52:40 -0700 (PDT) Received: by mail-il1-x141.google.com with SMTP id q1so9175773ilt.6; Sat, 31 Oct 2020 08:52:40 -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=qOPt4BECPdA3YISIeZuCSrNm7VpOf59xjoy7hduu96M=; b=guuU9AcLClZ14Z6yaYzC2sVsSZrrOL7gAqwt1FBX5R5ucqJypqE61w8zO2vJJ+R5OP Msy89p3jTvkSuIxtLltuBascrDqcqIxt6MjvsxmVCQN4Lmg/4p9uSkrzeafP0J0WU5cw nmwBNHUrtJ5IzBcLiPK+undMICSAMO1PS6XcBwoQclNCTkkHRlLeqbD8P1VyC4CM4782 phyXsVXeUayKR7/vXW1uHl/AOhCYylBs/+DzYo+gSbo/8oA6Av7XyCEeEUzXu4A2z2yF rywTzwZ6CltfmD7m6Fr7GMdiM32IQyFu0yRqoKoKdiEsgKvrV36vMdLY1PPU//40gbA2 OKmg== 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=qOPt4BECPdA3YISIeZuCSrNm7VpOf59xjoy7hduu96M=; b=ihBiBFBP6m69SkfK76KIa5blzZccBfR/B/rywNsMzHEKIadqkhYWckBS3E1hgXz+cf u9SOF52k11u+ty02amlH/X6NpW7KzfQRpDlXYS6PYUo7kgXJer1i6YMVcG5T9m8AizDy o9heOMERbSFsJ/wIn0p2V+VsZ6sW2gvvstzXLtXy2rdXjpe0fUzx2jxd/uVoWViLn3/R Q3aluHUIMEPdOCTUKdkFMkXW659IKWED7tbaLxvyCSuUZGOSGKDXa5LVOXc0WVpAm6E0 jJZvuMpjp+xQOwYmd/kW3cfC8tKSMMBj6yUeesqtfVkK8/0Z6DOCKkj09ddfA22BP/Ab bTKQ== X-Gm-Message-State: AOAM530cnVTqPnFDGikY8lcjwyPKXLLiHVObZfY5T9wCE1+5gCR1JVyR NdQHfD9FjzSE0AdfklBzlDs= X-Google-Smtp-Source: ABdhPJwJ4750X04UhtyNtvyS2fPKOWFOKQXO5wkY5SX0ip8jCRsKoe1BWA1+jXFZ59Y1A1yk6qr/Sg== X-Received: by 2002:a92:4a02:: with SMTP id m2mr5432246ilf.51.1604159559987; Sat, 31 Oct 2020 08:52:39 -0700 (PDT) Received: from Davids-MacBook-Pro.local ([2601:282:803:7700:10cc:b439:52ba:687f]) by smtp.googlemail.com with ESMTPSA id w22sm6317579iob.32.2020.10.31.08.52.38 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 31 Oct 2020 08:52:39 -0700 (PDT) Subject: Re: [PATCH bpf-next V5 2/5] 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: <160407661383.1525159.12855559773280533146.stgit@firesoul> <160407665728.1525159.18300199766779492971.stgit@firesoul> From: David Ahern Message-ID: <7a836323-3f22-0143-3f12-cc67fd9a43a6@gmail.com> Date: Sat, 31 Oct 2020 09:52:38 -0600 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: <160407665728.1525159.18300199766779492971.stgit@firesoul> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 10/30/20 10:50 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. > > V5: > - Fixed uninit value spotted by Dan Carpenter. > - Name struct output member mtu_result > > Reported-by: kernel test robot > Reported-by: Dan Carpenter > Signed-off-by: Jesper Dangaard Brouer > --- > include/uapi/linux/bpf.h | 11 +++++++++-- > net/core/filter.c | 22 +++++++++++++++------- > tools/include/uapi/linux/bpf.h | 11 +++++++++-- > 3 files changed, 33 insertions(+), 11 deletions(-) > Reviewed-by: David Ahern