Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751697AbdIFGjO convert rfc822-to-8bit (ORCPT ); Wed, 6 Sep 2017 02:39:14 -0400 Received: from cmccmta2.chinamobile.com ([221.176.66.80]:19301 "EHLO cmccmta2.chinamobile.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750752AbdIFGjL (ORCPT ); Wed, 6 Sep 2017 02:39:11 -0400 X-RM-TRANSID: 2ee659af9807591-814eb X-RM-SPAM-FLAG: 00000000 X-RM-TRANSID: 2ee359af9806b40-d1865 Content-Type: text/plain; charset=gb2312 Mime-Version: 1.0 (Mac OS X Mail 10.3 \(3273\)) Subject: Re: [PATCH v3 2/2] ip6_tunnel: fix ip6 tunnel lookup in collect_md mode From: =?gb2312?B?0c+6o8ur?= In-Reply-To: Date: Wed, 6 Sep 2017 14:39:02 +0800 Cc: "David S. Miller" , Pravin Shelar , Linux Kernel Network Developers , LKML Content-Transfer-Encoding: 8BIT Message-Id: References: <1504514174-14958-1-git-send-email-yanhaishuang@cmss.chinamobile.com> <1504514174-14958-2-git-send-email-yanhaishuang@cmss.chinamobile.com> To: Alexei Starovoitov X-Mailer: Apple Mail (2.3273) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1575 Lines: 49 > On 2017??9??6??, at ????11:14, Alexei Starovoitov wrote: > > On 9/4/17 1:36 AM, Haishuang Yan wrote: >> In collect_md mode, if the tun dev is down, it still can call >> __ip6_tnl_rcv to receive on packets, and the rx statistics increase >> improperly. >> >> Fixes: 8d79266bc48c ("ip6_tunnel: add collect_md mode to IPv6 tunnels") >> Cc: Alexei Starovoitov >> Signed-off-by: Haishuang Yan >> >> --- >> Change since v3: >> * Increment rx_dropped if tunnel device is not up, suggested by >> Pravin B Shelar >> * Fix wrong recipient address >> --- >> net/ipv6/ip6_tunnel.c | 7 +++++-- >> 1 file changed, 5 insertions(+), 2 deletions(-) >> >> diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c >> index 10a693a..e91d3b6 100644 >> --- a/net/ipv6/ip6_tunnel.c >> +++ b/net/ipv6/ip6_tunnel.c >> @@ -171,8 +171,11 @@ static struct net_device_stats *ip6_get_stats(struct net_device *dev) >> } >> >> t = rcu_dereference(ip6n->collect_md_tun); >> - if (t) >> - return t; >> + if (t) { >> + if (t->dev->flags & IFF_UP) >> + return t; >> + t->dev->stats.rx_dropped++; >> + } > > Why increment the stats only for this drop case? Because It was suggested by Pravin on v2 commit of the patch. > There are plenty of other conditions where packet > will be dropped in ip6 tunnel. I think it's important > to present consistent behavior to the users, > so I'd increment drop stats either for all drop cases > or for none. And today it's none. > The ! IFF_UP case should probably be return NULL too > >