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 86E29C31E40 for ; Sat, 13 Jul 2019 22:47:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4884120848 for ; Sat, 13 Jul 2019 22:47:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ZAq5exjD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728109AbfGMWmd (ORCPT ); Sat, 13 Jul 2019 18:42:33 -0400 Received: from mail-io1-f45.google.com ([209.85.166.45]:42199 "EHLO mail-io1-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728035AbfGMWmd (ORCPT ); Sat, 13 Jul 2019 18:42:33 -0400 Received: by mail-io1-f45.google.com with SMTP id u19so27945062ior.9 for ; Sat, 13 Jul 2019 15:42:33 -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=pp70/rX2Q5+wOAjth3RPYkTBVn2OKxynHYnWijVSFr4=; b=ZAq5exjD5rOkLOaA+vkAg3LluvzjNF2Q5AEGitTPIi5GzUJU6vpUXqttfdcCnuEoIa cAavFjATB0eu5vQH6+imiV1r5SrLVWBNboDdh75mQOUk/DvjaBqMtW3e33WL3VxQL3KB W1nVB9NE6lGAKuaHqx00CSUl8g/Z+7r8AwUPjMdYUdfoJ8KVYT4F8/aKOC8+Qg7f6JiK dKUv4iTS3jHEK1HuoxE+dQqGl818avz7T+YlqXwEAW60rS6gaCN2HiU055FC5HPq6ciG 4f9jQUJ1BWmW9e7/SMIg82pXoPqn7+mf0Go/zhDh/cjh3KFEYump0Jle5JL+IInuRaen 17Vw== 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=pp70/rX2Q5+wOAjth3RPYkTBVn2OKxynHYnWijVSFr4=; b=LMEIdq8qz/gD892/bvuHAGLk+GrQ+mqw66Vplzf3kmO1NRIWQPAIYKhSEt2Fj5BBE4 jyTHlZTh5ybtfWS2MVsAtGTnFx6CWSrI/ee/yDsI3xJ8+Gs8G/vSRwm79XlJIa2CSFG5 ZpBa6+ry36MzLOAA/GpWc3tUm0ryFMR7dN5qCsmbZPTKKFpoe25cvuAwHE0PBF6PGodW dZfRQAipI/SukzlLVXLpOUkPplaqlDVX80AJ5f5xd5IhTRsZVxj032nU51GzN+A/SEGm ZvgGZmpvR7zBbyOftbgoy6R1X0ys3kdCmT8kIO5Rwett/vMqUfsOqWBPPcpHiDIpT6RJ H2Iw== X-Gm-Message-State: APjAAAXrGax0VIghKa2sWyMoWyoBiOKWHrqPAPR0QErTIritaszHufL7 pVviay6HbPuv3oSfxhO0AwY= X-Google-Smtp-Source: APXvYqyuMHYl+28siLOxHDqrnPp7mOtm5i81E1B/z2am6i6bgNbp2khqV/sKQY/48uX9H9B3kCyR2g== X-Received: by 2002:a6b:bf87:: with SMTP id p129mr15460896iof.253.1563057752676; Sat, 13 Jul 2019 15:42:32 -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 y20sm9802744ion.77.2019.07.13.15.42.31 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 13 Jul 2019 15:42:31 -0700 (PDT) Subject: Re: [Patch net] fib: relax source validation check for loopback packets To: Cong Wang , netdev@vger.kernel.org Cc: Julian Anastasov References: <20190712201749.28421-2-xiyou.wangcong@gmail.com> From: David Ahern Message-ID: <8355af23-100f-a3bb-0759-fca8b0aa583b@gmail.com> Date: Sat, 13 Jul 2019 16:42:30 -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: <20190712201749.28421-2-xiyou.wangcong@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 7/12/19 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? > + IN_DEV_ACCEPT_LOCAL(idev)); Why is this check needed? Can you give an example use that is fixed - and add one to selftests/net/fib_tests.sh? > if (dev_match) { > ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST; > return ret; >