net: sched: act_mirred: Reset ct info when mirror/redirect skb

[ Upstream commit d09c548dbf3b31cb07bba562e0f452edfa01efe3 ]

When mirror/redirect a skb to a different port, the ct info should be reset
for reclassification. Or the pkts will match unexpected rules. For example,
with following topology and commands:

    -----------
              |
       veth0 -+-------
              |
       veth1 -+-------
              |
   ------------

 tc qdisc add dev veth0 clsact
 # The same with "action mirred egress mirror dev veth1" or "action mirred ingress redirect dev veth1"
 tc filter add dev veth0 egress chain 1 protocol ip flower ct_state +trk action mirred ingress mirror dev veth1
 tc filter add dev veth0 egress chain 0 protocol ip flower ct_state -inv action ct commit action goto chain 1
 tc qdisc add dev veth1 clsact
 tc filter add dev veth1 ingress chain 0 protocol ip flower ct_state +trk action drop

 ping <remove ip via veth0> &
 tc -s filter show dev veth1 ingress

With command 'tc -s filter show', we can find the pkts were dropped on
veth1.

Fixes: b57dc7c13e ("net/sched: Introduce action ct")
Signed-off-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Hangbin Liu 2021-08-09 15:04:55 +08:00 committed by Greg Kroah-Hartman
parent f15f7716b0
commit 059238c52c

View File

@ -261,6 +261,9 @@ static int tcf_mirred_act(struct sk_buff *skb, const struct tc_action *a,
goto out;
}
/* All mirred/redirected skbs should clear previous ct info */
nf_reset_ct(skb2);
want_ingress = tcf_mirred_act_wants_ingress(m_eaction);
expects_nh = want_ingress || !m_mac_header_xmit;