| Message ID | 1345099467-40922-1-git-send-email-jasowang@redhat.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On Thu, 2012-08-16 at 14:44 +0800, Jason Wang wrote: > 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 <jasowang@redhat.com> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> cheers, jamal -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Jamal Hadi Salim <jhs@mojatatu.com> Date: Thu, 16 Aug 2012 08:11:47 -0400 > On Thu, 2012-08-16 at 14:44 +0800, Jason Wang wrote: >> 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 <jasowang@redhat.com> > > Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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;
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 <jasowang@redhat.com> --- 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(-)