From 7c8a60a9e3cdfcc04bc4de488876c07225fa0347 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Wed, 15 Aug 2012 20:44:27 +0000 Subject: [PATCH] act_mirred: do not drop packets when fails to mirror it [ 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: Greg Kroah-Hartman --- 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; -- 2.7.4