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=-5.9 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,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 E4559C433E7 for ; Fri, 28 Aug 2020 09:14:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C32792071B for ; Fri, 28 Aug 2020 09:14:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ASAb4ZKP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728708AbgH1JOc (ORCPT ); Fri, 28 Aug 2020 05:14:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35102 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728218AbgH1JO3 (ORCPT ); Fri, 28 Aug 2020 05:14:29 -0400 Received: from mail-wr1-x441.google.com (mail-wr1-x441.google.com [IPv6:2a00:1450:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0CAF8C061264; Fri, 28 Aug 2020 02:14:29 -0700 (PDT) Received: by mail-wr1-x441.google.com with SMTP id l7so595120wrx.8; Fri, 28 Aug 2020 02:14:28 -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=bFeVd3y76f8JCnVoxv7uErhjRJ/Acf3IGCqwDe0vYzo=; b=ASAb4ZKP8q64pDUw994tv3+INDcE6zs3SLcXLuq022GJSwmDFTUIbp0r5/gUTHxImB AeTldyKDlHW8yA4Y4athGifCHZUW5eInuIS/dJI4KbZmYx5/1cwuGEp2ZtwkNJO1cUZG /79oGU/ew5dOOUT1MdppsyGCkaAQnNvvuQLyx32CONUDD6Gw+LgKMqTm/rvAnPtwWrc2 lZ0VHi/rtBY99xPPqy+HvqxGeOzRXxXvM5YXd0SgvbDwpvZoz1xjmPc+bqG51UIBu+1i ijBorsf4YoOnyM+A1Y/H7B0m8z1s/UtBhuafPkhwTRpNjE2cpUI6btJfTpE/BwltRL+w MjCA== 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=bFeVd3y76f8JCnVoxv7uErhjRJ/Acf3IGCqwDe0vYzo=; b=GKUTSGWRAUgprAZKvYAxWfJJ9vci1S+qXvGNAQIK4n88cHPKOXrzePvaaAZmXgRpBs CN0HIZgkIudSq/fJJmenHfvraCdhUt36vuBQJYbIdiWeiy9M5dUmVJNz79RcIejFulDy KfuA+2t6ANwavTHdpOcf+V4bNMNw1MAHHI7EkvWgoViL2PZ2Eu1PCZuw7tJ5ps2+5hr3 DmXFC+buMOCgRDwJMm6lFNqYHErqPPGP/ThY4Jhi8X2VlJ8n68AP+tqf4SP4mx6LcncS nuSMGOiSYcqtCr3Gtn/si0be6ZWyUcG44aBGlwzKfDu2CYiGtF4zuYZbx6i8BtBs9trg pttg== X-Gm-Message-State: AOAM531BwQAHCwG1B0nbkf5+D1g+BUYFeJPyWc64RQ9aZOLDFkWK1qAm p92gIGh7WBBMT/ftgnvmbUWSJZVVUtY= X-Google-Smtp-Source: ABdhPJwptDnJe4CUd3jREwjgLVQaaP6WY676T+Tlsou+GFhr1kWQhjvUYUyk9XPHFR72Jg+REhSRdw== X-Received: by 2002:a05:6000:1204:: with SMTP id e4mr613648wrx.95.1598606067682; Fri, 28 Aug 2020 02:14:27 -0700 (PDT) Received: from [192.168.8.147] ([37.171.241.197]) by smtp.gmail.com with ESMTPSA id p1sm2713000wma.0.2020.08.28.02.14.26 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 28 Aug 2020 02:14:27 -0700 (PDT) Subject: Re: [PATCH nf-next v3 0/3] Netfilter egress hook To: Daniel Borkmann , Lukas Wunner , Pablo Neira Ayuso , Jozsef Kadlecsik , Florian Westphal Cc: netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org, Alexei Starovoitov , Eric Dumazet , Thomas Graf , Laura Garcia , David Miller References: <454130d7-7256-838d-515e-c7340892278c@iogearbox.net> From: Eric Dumazet Message-ID: Date: Fri, 28 Aug 2020 11:14:25 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <454130d7-7256-838d-515e-c7340892278c@iogearbox.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org On 8/28/20 12:14 AM, Daniel Borkmann wrote: > Hi Lukas, > > On 8/27/20 10:55 AM, Lukas Wunner wrote: >> Introduce a netfilter egress hook to allow filtering outbound AF_PACKETs >> such as DHCP and to prepare for in-kernel NAT64/NAT46. > > Thinking more about this, how will this allow to sufficiently filter AF_PACKET? > It won't. Any AF_PACKET application can freely set PACKET_QDISC_BYPASS without > additional privileges and then dev_queue_xmit() is being bypassed in the host ns. > This is therefore ineffective and not sufficient. (From container side these can > be caught w/ host veth on ingress, but not in host ns, of course, so hook won't > be invoked.) Presumably dev_direct_xmit() could be augmented to support the hook. dev_direct_xmit() (packet_direct_xmit()) was introduced to bypass qdisc, not to bypass everything.