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=-5.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,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 0B8A7C31E40 for ; Sun, 14 Jul 2019 00:30:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CA3AA2064A for ; Sun, 14 Jul 2019 00:30:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="buNB6BpQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728754AbfGNA3V (ORCPT ); Sat, 13 Jul 2019 20:29:21 -0400 Received: from mail-io1-f66.google.com ([209.85.166.66]:44875 "EHLO mail-io1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728742AbfGNA3V (ORCPT ); Sat, 13 Jul 2019 20:29:21 -0400 Received: by mail-io1-f66.google.com with SMTP id s7so28157586iob.11 for ; Sat, 13 Jul 2019 17:29:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:from:to:cc:references:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=fkhvfQ6T3SnfPb9oplxSk5QRUte1FbyCfHytK73HPQ0=; b=buNB6BpQK5bQB/ZqDaQ8td6ZCVqQ64Qn6zD3XSSuX+RZuYEDw3yKQs7EPjOCtijAtb 4ZneFCxK+iGiBSvbn938qL4Uzh5XFIfIn+OuM5eQKAvui0KpFkXbuPyl30LBQmQakBoc w/NkWIZ/Z5Oi7eZoLYLuFK9zbSOaYAifQwtQfAoRDh8MXaSafC6eMXjFgZFR0mBcwYRM r/gZ1A+1i7nDSfP7YfGZnAbp681WQ53o1jKNZTG7qWXFXz3jhSioYuTv6QPk7IgeXbgY vAjHr9ieWujS0i3jm0fV3AVgylCtDODDbFu2ub+0OvMPsDlvZcS7ouwpWnwNUDfs/3tN ovow== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:references:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=fkhvfQ6T3SnfPb9oplxSk5QRUte1FbyCfHytK73HPQ0=; b=UXMAT4uEpmnJJe53nG9TciF5nywkF2DJhEL7KZUv3NOMH31SESd+Q/3VQuEYijRmtH 5xyYEmhJktq1ViwalecZuJtVl8565IiXhki7j9s4V95ylMvrJS6T5f/XPrinal/CVcEK zCo4vxPO0cVrtlvu8hOQLGkCDghMu2cPOv3BLRF58mGVZP5lq5vml5n2L5PCbn0b+rEy afVBXxjgvGhKS0ukQzU+HWpPZbodDn2NZNfqiV3dXjw8iC/pMNJrTUGD9wuzyUzf8LNM o1i2ikUi58IaZ4kSHA/EqZ40/QbIHTFPpgL/Pzcd3K5AFZZNKIFgqFzcytXIA0TFqkfn i6mg== X-Gm-Message-State: APjAAAWedrRv1ewDXCYXLZelps6624z6Cbg5TbPyaunLzwtMheFNQfqa Zf3nKKupYjBCr+qdtHkjFvr9KKsz X-Google-Smtp-Source: APXvYqwjbATyeCclBkw5Ag5vmUJGB2YWmbFmJ+2+HYErjY3nFmldRxxaIzl5UpnshXQvGg/lD7mVGw== X-Received: by 2002:a6b:7401:: with SMTP id s1mr17167555iog.67.1563064160184; Sat, 13 Jul 2019 17:29:20 -0700 (PDT) Received: from ?IPv6:2601:282:800:fd80:184d:26dc:d796:2ec1? ([2601:282:800:fd80:184d:26dc:d796:2ec1]) by smtp.googlemail.com with ESMTPSA id d25sm13429033iom.52.2019.07.13.17.29.18 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 13 Jul 2019 17:29:18 -0700 (PDT) Subject: Re: [Patch net] fib: relax source validation check for loopback packets From: David Ahern To: Cong Wang , netdev@vger.kernel.org Cc: Julian Anastasov References: <20190712201749.28421-2-xiyou.wangcong@gmail.com> <8355af23-100f-a3bb-0759-fca8b0aa583b@gmail.com> Message-ID: <128233e2-aa2c-d2a0-6249-68fd927a299f@gmail.com> Date: Sat, 13 Jul 2019 18:29:17 -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: <8355af23-100f-a3bb-0759-fca8b0aa583b@gmail.com> 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 7/13/19 4:42 PM, David Ahern wrote: > On 7/12/19 2:17 PM, Cong Wang wrote: >> diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c >> index 317339cd7f03..8662a44a28f9 100644 >> --- a/net/ipv4/fib_frontend.c >> +++ b/net/ipv4/fib_frontend.c >> @@ -388,6 +388,12 @@ static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, >> fib_combine_itag(itag, &res); >> >> dev_match = fib_info_nh_uses_dev(res.fi, dev); >> + /* This is rare, loopback packets retain skb_dst so normally they >> + * would not even hit this slow path. >> + */ >> + dev_match = dev_match || (res.type == RTN_LOCAL && >> + dev == net->loopback_dev && > > The dev should not be needed. res.type == RTN_LOCAL should be enough, no? > nevermind, I see why you have the dev check.