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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 965D8C43143 for ; Tue, 11 Sep 2018 02:19:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AF79020839 for ; Tue, 11 Sep 2018 02:19:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AF79020839 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=cmss.chinamobile.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726622AbeIKHQg convert rfc822-to-8bit (ORCPT ); Tue, 11 Sep 2018 03:16:36 -0400 Received: from cmccmta3.chinamobile.com ([221.176.66.81]:43622 "EHLO cmccmta3.chinamobile.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726182AbeIKHQg (ORCPT ); Tue, 11 Sep 2018 03:16:36 -0400 Received: from spf.mail.chinamobile.com (unknown[172.16.121.19]) by rmmx-syy-dmz-app09-12009 (RichMail) with SMTP id 2ee95b97263582c-6837c; Tue, 11 Sep 2018 10:19:33 +0800 (CST) X-RM-TRANSID: 2ee95b97263582c-6837c X-RM-TagInfo: emlType=0 X-RM-SPAM-FLAG: 00000000 Received: from [172.16.200.163] (unknown[112.25.154.148]) by rmsmtp-syy-appsvr10-12010 (RichMail) with SMTP id 2eea5b97263374e-044ee; Tue, 11 Sep 2018 10:19:33 +0800 (CST) X-RM-TRANSID: 2eea5b97263374e-044ee Content-Type: text/plain; charset=gb2312 Mime-Version: 1.0 (Mac OS X Mail 10.3 \(3273\)) Subject: Re: [PATCH] ip6_gre: simplify gre header parsing in ip6gre_err From: Haishuang Yan In-Reply-To: <20180910173640.117bf42f@redhat.com> Date: Tue, 11 Sep 2018 10:19:31 +0800 Cc: "David S. Miller" , Alexey Kuznetsov , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8BIT Message-Id: References: <1536567909-25089-1-git-send-email-yanhaishuang@cmss.chinamobile.com> <20180910173640.117bf42f@redhat.com> To: Jiri Benc X-Mailer: Apple Mail (2.3273) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On 2018Äê9ÔÂ10ÈÕ, at ÏÂÎç11:36, Jiri Benc wrote: > > On Mon, 10 Sep 2018 16:25:09 +0800, Haishuang Yan wrote: >> + if (gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6), >> + offset) < 0) { >> + if (!csum_err) /* ignore csum errors. */ >> + return; >> } > > gre_parse_header stops parsing when csum_err is encountered. Which > means tpi.key is undefined... > >> >> - if (!pskb_may_pull(skb, offset + grehlen)) >> - return; >> ipv6h = (const struct ipv6hdr *)skb->data; >> - greh = (const struct gre_base_hdr *)(skb->data + offset); >> - key = key_off ? *(__be32 *)(skb->data + key_off) : 0; >> - >> t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr, >> - key, greh->protocol); >> + tpi.key, tpi.proto); > > ...and can't be used here. > > Jiri > You are right. Thanks for reviewing. So the same problem also arise in ipgre_err code: 187 iph = (const struct iphdr *)(icmp_hdr(skb) + 1); 188 t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, 189 iph->daddr, iph->saddr, tpi->key); Since csum_err may not be used outside, how about refactoring gre_parse_header function like this: --- a/net/ipv4/gre_demux.c +++ b/net/ipv4/gre_demux.c @@ -86,7 +86,7 @@ int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi, options = (__be32 *)(greh + 1); if (greh->flags & GRE_CSUM) { - if (skb_checksum_simple_validate(skb)) { + if (csum_err && skb_checksum_simple_validate(skb)) { *csum_err = true; return -EINVAL; } And in gre_err function, we can call gre_parse_header(skb, &tpi, NULL, **) like this: --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -234,11 +234,9 @@ static void gre_err(struct sk_buff *skb, u32 info) struct tnl_ptk_info tpi; bool csum_err = false; - if (gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), - iph->ihl * 4) < 0) { - if (!csum_err) /* ignore csum errors. */ + if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IP), + iph->ihl * 4) < 0) return; - }