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=-5.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 3C50AC32751 for ; Wed, 7 Aug 2019 17:53:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0F0EB222FC for ; Wed, 7 Aug 2019 17:53:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="JP6n4lR/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389041AbfHGRw7 (ORCPT ); Wed, 7 Aug 2019 13:52:59 -0400 Received: from mail-pl1-f196.google.com ([209.85.214.196]:34214 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387952AbfHGRw7 (ORCPT ); Wed, 7 Aug 2019 13:52:59 -0400 Received: by mail-pl1-f196.google.com with SMTP id i2so41929564plt.1; Wed, 07 Aug 2019 10:52:58 -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=U9jURJQ1Uv/DDXBBVFiM0Yx2vC/nTJ5FNJbf0XwSXME=; b=JP6n4lR/dA1+ETGt2vNBFvAISfXJKVyuZg3q4R+tYSDmwDIe7yVp/iDibgeINYmWjX gF2B2+GNwy+XEcrIC5cBPeQBVJiFsn9BG4vCQ/Kdf31HayvW+y15/tr0dg32mfZj/6Xc SLLdDO2oVu9By9/tp3SL+YwWoo2mo5G6v5rcdG3Y+9o2Xr1jvne7E0UA46pccZ13ETOZ nr666LA0/Hdyk+cuO6XWiqG5VEf32YgDSlaE61gqJkNsgDX4Qml+JDoAp0Rd9/7Ik2CP qXpRI+iqPMTsWrrM/BkZWTEZES2GgqxpZYinA3f354lpfsEV40SopQrjmY8f4/9RuPXL V7sQ== 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=U9jURJQ1Uv/DDXBBVFiM0Yx2vC/nTJ5FNJbf0XwSXME=; b=IE2aIclaxRrECUZrxnqlM0QvlmJv6sx4z61940JccTRubtscibbYN/gyCgm6B8KiQf ucEnb0Bp1aGSo5RocsQJhYjoTmQ3z0X38nBNRmP94G2YQd1hlpGV7x9csORO7Y5npV/Z vhaS6JxFmUgxJzQ/xHKH6FV/XyBBxgdwO3smUCab68s/B1HVa0CWt7W6YtYUZs7aopEv o2jvoFE4qYJonJfpKLqTvGJrQBUKGwQN2QUB1+KWjkga67+PYpVTdKO/r2W/HOiVaCPe 2CYC7zN2lK7/7xaPmOogUtSxrqSko6u6JZSWzal1dFzO0gLKshJ69tzJhRHJlyvzI12W 8Q7Q== X-Gm-Message-State: APjAAAXrE93urVma50iHp6UOt7wwh5iPU+X2qE4JacyVeU82yn1wYSGR dtMVYcjs2B3HGoaeS+VgAO8= X-Google-Smtp-Source: APXvYqzHGOJHyi88ZgDd3CqnuW2dE1+GFO/h5SZwZ+XpSaRFkHKmxNboOldlrSNAhD9CACisPs+23Q== X-Received: by 2002:a17:902:f213:: with SMTP id gn19mr9517558plb.35.1565200378479; Wed, 07 Aug 2019 10:52:58 -0700 (PDT) Received: from [172.27.227.247] ([216.129.126.118]) by smtp.googlemail.com with ESMTPSA id m6sm91652238pfb.151.2019.08.07.10.52.57 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 07 Aug 2019 10:52:57 -0700 (PDT) Subject: Re: [bpf-next PATCH 3/3] samples/bpf: xdp_fwd explain bpf_fib_lookup return codes To: Jesper Dangaard Brouer , netdev@vger.kernel.org, Daniel Borkmann , Alexei Starovoitov Cc: xdp-newbies@vger.kernel.org, a.s.protopopov@gmail.com References: <156518133219.5636.728822418668658886.stgit@firesoul> <156518138817.5636.3626699603179533211.stgit@firesoul> From: David Ahern Message-ID: Date: Wed, 7 Aug 2019 11:52:56 -0600 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <156518138817.5636.3626699603179533211.stgit@firesoul> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 8/7/19 6:36 AM, Jesper Dangaard Brouer wrote: > Make it clear that this XDP program depend on the network > stack to do the ARP resolution. This is connected with the > BPF_FIB_LKUP_RET_NO_NEIGH return code from bpf_fib_lookup(). > > Another common mistake (seen via XDP-tutorial) is that users > don't realize that sysctl net.ipv{4,6}.conf.all.forwarding > setting is honored by bpf_fib_lookup. > > Reported-by: Anton Protopopov > Signed-off-by: Jesper Dangaard Brouer > --- > samples/bpf/xdp_fwd_kern.c | 19 +++++++++++++++++-- > 1 file changed, 17 insertions(+), 2 deletions(-) > Reviewed-by: David Ahern