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=-7.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 A49C7C433E0 for ; Fri, 29 Jan 2021 06:07:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7592164DFF for ; Fri, 29 Jan 2021 06:07:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232023AbhA2GH2 (ORCPT ); Fri, 29 Jan 2021 01:07:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46398 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230121AbhA2GHZ (ORCPT ); Fri, 29 Jan 2021 01:07:25 -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 5891AC061573; Thu, 28 Jan 2021 22:06:45 -0800 (PST) Received: by mail-io1-xd31.google.com with SMTP id 16so8180460ioz.5; Thu, 28 Jan 2021 22:06:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:message-id:in-reply-to:references:subject :mime-version:content-transfer-encoding; bh=z1upcokDa9M3p7R0rq2fGbu55r01gKcaNgSaRbQ/XcM=; b=MXK/GJnZZzBuf9C5qkj8lbmIEhRzgDxKsZy2YxRN+PES1OApV9pWTQ2Toi31SJuYS8 SGYwDhO1wTBUHAw226o9PIHzxO9Krix/WJ6JYLF/oIZzCViI0uEF30L/Z3MxnqvJZeXZ DSLa9pnv36d8M/XHgwE/GfVWHDvUNwqEDdiAh6nKwpvBXsNAYPuJAYUG9xvugU7zvDAL ArC3uP1MOM+/vqUk7NSeaku+vYLZAdjuPZFSX9GS8afnSxG/CzYSOF+ATZYv7yMoCIbk cll68zQ5wvPd1MZEIw0blQSSnIR6lIKOgtIcoC/Ca3OK+JQBEMjRenKt3RDdFyFvU8gg gm4g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:message-id:in-reply-to :references:subject:mime-version:content-transfer-encoding; bh=z1upcokDa9M3p7R0rq2fGbu55r01gKcaNgSaRbQ/XcM=; b=MXSUHTeVhLnpA6pDsCb/nXcx3N83ZPTKjlmFYqS6qY9sJfsBTvn/rUG3rxVZ5s0yrv YyE+JdaW0QClx1Pg7+Op9sejnupMUKvsj81e5irUEumk9Vvd5cZ9pP1nhi0MdntISiXH 5NrzGsWJdEYJoASFyMwOF3jXg7B7fpy0xJEgjA5mfWHOGNpNtrebvra2ngqEVJ4Q8Tr8 oMSHgE9X/L8bjAJl4KasV33y8niKkUtXGf82PNi14/IXYr6MUpXhNGhIYWpcn0zZlBMK Kihfd226wDWxWUYQ83+QyO3RdziMhr+d6CY/eb1vc2yo6oIKzk19ptULRFhDmYXyter0 tCbQ== X-Gm-Message-State: AOAM532iPjvowrXEZxP0BiC89ag169u/Dl8tZ50dB0FUVheCCkEAD66M ofX5YUFpunX7LBB9Lssju9M= X-Google-Smtp-Source: ABdhPJyi86XiwUiFErCD4vOYtAHx6v38tZVMH0OpwFfJV3Eac7/2HCweysMuyO9Oeo46qtSf6AMQQw== X-Received: by 2002:a05:6602:24d4:: with SMTP id h20mr2169366ioe.64.1611900404886; Thu, 28 Jan 2021 22:06:44 -0800 (PST) Received: from localhost ([172.243.146.206]) by smtp.gmail.com with ESMTPSA id i8sm3939046ilb.38.2021.01.28.22.06.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 28 Jan 2021 22:06:44 -0800 (PST) Date: Thu, 28 Jan 2021 22:06:36 -0800 From: John Fastabend To: Jesper Dangaard Brouer , bpf@vger.kernel.org Cc: Jesper Dangaard Brouer , 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, colrack@gmail.com Message-ID: <6013a5ec3f7c7_2683c208a5@john-XPS-13-9370.notmuch> In-Reply-To: <161159456731.321749.5837621737819856023.stgit@firesoul> References: <161159451743.321749.17528005626909164523.stgit@firesoul> <161159456731.321749.5837621737819856023.stgit@firesoul> Subject: RE: [PATCH bpf-next V13 3/7] bpf: bpf_fib_lookup return MTU value as output when looked up Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org 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 > --- LGTM. Acked-by: John Fastabend