[PATCH net] net/sched: act_ct: fix restore the qdisc_skb_cb after defrag

[wenxu]

From: wenxu <we...@ucloud.cn>

The fragment packets do defrag in tcf_ct_handle_fragments
will clear the skb->cb which make the qdisc_skb_cb clear
too. So the qdsic_skb_cb should be store before defrag and
restore after that.
It also update the pkt_len after all the
fragments finish the defrag to one packet and make the
following actions counter correct.

Fixes: b57dc7c13ea9 ("net/sched: Introduce action ct")
Signed-off-by: wenxu <we...@ucloud.cn>
---

This patch resend followup with
"http://patchwork.ozlabs.org/project/netdev/cover/1594097711-9365-1-git-send-email-we...@ucloud.cn/";

 net/sched/act_ct.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c
index 67504ae..e675e2d 100644
--- a/net/sched/act_ct.c
+++ b/net/sched/act_ct.c
@@ -676,6 +676,7 @@ static int tcf_ct_handle_fragments(struct net *net, struct 
sk_buff *skb,
                                   u8 family, u16 zone)
 {
        enum ip_conntrack_info ctinfo;
+       struct qdisc_skb_cb cb;
        struct nf_conn *ct;
        int err = 0;
        bool frag;
@@ -693,6 +694,7 @@ static int tcf_ct_handle_fragments(struct net *net, struct 
sk_buff *skb,
                return err;
 
        skb_get(skb);
+       cb = *qdisc_skb_cb(skb);
 
        if (family == NFPROTO_IPV4) {
                enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
@@ -717,6 +719,7 @@ static int tcf_ct_handle_fragments(struct net *net, struct 
sk_buff *skb,
 #endif
        }
 
+       *qdisc_skb_cb(skb) = cb;
        skb_clear_hash(skb);
        skb->ignore_df = 1;
        return err;
@@ -1014,6 +1017,7 @@ static int tcf_ct_act(struct sk_buff *skb, const struct 
tc_action *a,
 
 out:
        tcf_action_update_bstats(&c->common, skb);
+       qdisc_skb_cb(skb)->pkt_len = skb->len;
        return retval;
 
 drop:
-- 
1.8.3.1