Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755401Ab2HPGvK (ORCPT ); Thu, 16 Aug 2012 02:51:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:7330 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755010Ab2HPGvH (ORCPT ); Thu, 16 Aug 2012 02:51:07 -0400 From: Jason Wang To: jhs@mojatatu.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, davem@davemloft.net Cc: Jason Wang Subject: [net V2] act_mirred: do not drop packets when fails to mirror it Date: Thu, 16 Aug 2012 14:44:27 +0800 Message-Id: <1345099467-40922-1-git-send-email-jasowang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1742 Lines: 51 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 --- Changes from v1: - Check with TCA_EGRESS_MIRROR instead of TC_ACT_STOLEN per Jamal's comment net/sched/act_mirred.c | 11 +++++------ 1 files changed, 5 insertions(+), 6 deletions(-) diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c index fe81cc1..9c0fd0c 100644 --- a/net/sched/act_mirred.c +++ b/net/sched/act_mirred.c @@ -200,13 +200,12 @@ 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; -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/