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=-10.3 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 D96EDC55179 for ; Tue, 27 Oct 2020 17:21:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8655520809 for ; Tue, 27 Oct 2020 17:21:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="nEM8Wnge" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1818002AbgJ0RQs (ORCPT ); Tue, 27 Oct 2020 13:16:48 -0400 Received: from mail-io1-f67.google.com ([209.85.166.67]:43554 "EHLO mail-io1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1817367AbgJ0RPf (ORCPT ); Tue, 27 Oct 2020 13:15:35 -0400 Received: by mail-io1-f67.google.com with SMTP id h21so2350262iob.10; Tue, 27 Oct 2020 10:15:34 -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=UNZZEUo7M3Py+N4O575RWXsyVUJ1PdLqmuN8Dya1LYg=; b=nEM8WngeKxQWl7pJraFvnO0/aEHZzGQVcIydUu+B66VjxG2JwBDTxnLzg6CIAeRqzT JDoxLLrcKO8Y9T17m+u+kDfPD/qHHP8MRtZlwkPDJ0xQ3EhAEAwJbBo3JUoEB/Yv346x wKRWKBzJTy+EtIKTw2L8d2sDJowgfPCb6mhUUfiNAkfloakMMgPv58utYueo8SxMtquw /l7IAQGaOCdxflyPDjWhS230qiOuUig3rbVFnFgczz3sm5x09M6c9kwVDGozywv2GHs1 MtcoAq1eYJQ3qpsyb7+yw8mcvFWL5KcXfFra6lqvdtZfYFW1bM0YC6GML2r5SFHn3y6T Qmqg== 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=UNZZEUo7M3Py+N4O575RWXsyVUJ1PdLqmuN8Dya1LYg=; b=NNB5GssRMl35GuX1otetUtFlTDZ3MFNYeCtHYOulv6JX4g3ZZuGVT52/yJvfY9LRQV mI652LpPv6g65tOS1YLIKXVoTli9T8xnqMjXM11nOKk397a9A1W/J7FA8Mr6GP9T6q5q HusjLYXV0/CMQgk3yfr1lBNmXXRteZH3YDVsOeSj0QIQyevqmTRuqhgK18SowlN4kqFJ U4iIZDe564jOvpF1xo7Rb1W2JFU62daHFeZmLxLqen3KRLXttAZv5jgPgfkhWVqdDJot bo0GH41wLdMEeZ+W1doA5WTyp8lUALYRpPPYHB2eQ+Dt+F2sV2Bb4w3k46T0cEdMcesy 36Jw== X-Gm-Message-State: AOAM533pOkaK+4YXkZ2Xb+SaQdApRXEQlE0gSLdKTqWynJrPx4r25DHP NOmm9wmmnsfNYkU69KMXVWA= X-Google-Smtp-Source: ABdhPJxYpiS3Fhm2fn7zgSeQ/jwT8hDriulsc8LCKsMqBUxWubgu4PQf39G3i7mPwG36TQJ7aUXqTA== X-Received: by 2002:a6b:f401:: with SMTP id i1mr3161062iog.130.1603818934261; Tue, 27 Oct 2020 10:15:34 -0700 (PDT) Received: from Davids-MacBook-Pro.local ([2601:282:803:7700:f994:8208:36cb:5fef]) by smtp.googlemail.com with ESMTPSA id e4sm1285847ill.70.2020.10.27.10.15.31 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 27 Oct 2020 10:15:32 -0700 (PDT) Subject: Re: [PATCH bpf-next V4 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: <160381592923.1435097.2008820753108719855.stgit@firesoul> <160381601522.1435097.11103677488984953095.stgit@firesoul> From: David Ahern Message-ID: Date: Tue, 27 Oct 2020 11:15:31 -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: <160381601522.1435097.11103677488984953095.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 10/27/20 10:26 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