From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752887AbaFGBZG (ORCPT ); Fri, 6 Jun 2014 21:25:06 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:36186 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752709AbaFGBXk (ORCPT ); Fri, 6 Jun 2014 21:23:40 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "David S. Miller" , "Jamal Hadi Salim" , "Jason Wang" Date: Sat, 07 Jun 2014 02:26:28 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 23/92] act_mirred: do not drop packets when fails to mirror it In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.249 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.60-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Jason Wang [ Upstream commit 16c0b164bd24d44db137693a36b428ba28970c62 ] We drop packet unconditionally when we fail to mirror it. This is not intended in some cases. Consdier for kvm guest, we may mirror the traffic of the bridge to a tap device used by a VM. When kernel fails to mirror the packet in conditions such as when qemu crashes or stop polling the tap, it's hard for the management software to detect such condition and clean the the mirroring before. This would lead all packets to the bridge to be dropped and break the netowrk of other virtual machines. To solve the issue, the patch does not drop packets when kernel fails to mirror it, and only drop the redirected packets. Signed-off-by: Jason Wang Signed-off-by: Jamal Hadi Salim Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- net/sched/act_mirred.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c index e051398..d067ed1 100644 --- a/net/sched/act_mirred.c +++ b/net/sched/act_mirred.c @@ -201,13 +201,12 @@ static int tcf_mirred(struct sk_buff *skb, const struct tc_action *a, out: if (err) { m->tcf_qstats.overlimits++; - /* should we be asking for packet to be dropped? - * may make sense for redirect case only - */ - retval = TC_ACT_SHOT; - } else { + if (m->tcfm_eaction != TCA_EGRESS_MIRROR) + retval = TC_ACT_SHOT; + else + retval = m->tcf_action; + } else retval = m->tcf_action; - } spin_unlock(&m->tcf_lock); return retval;