[PATCH net 1/2] net/sched: act_ct: fix restore the qdisc_skb_cb after defrag

[wenxu@ucloud.cn]

From: wenxu <wenxu@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 and set the pkt_len to 0. The bytes always 0 when dump
the filter. And it also update the pkt_len after all the
fragments finish the defrag to one packet and make the
following action counter correct.

filter protocol ip pref 2 flower chain 0 handle 0x2
  eth_type ipv4
  dst_ip 1.1.1.1
  ip_flags frag/firstfrag
  skip_hw
  not_in_hw
 action order 1: ct zone 1 nat pipe
  index 2 ref 1 bind 1 installed 11 sec used 11 sec
 Action statistics:
 Sent 0 bytes 11 pkt (dropped 0, overlimits 0 requeues 0)
 backlog 0b 0p requeues 0
 cookie e04106c2ac41769b278edaa9b5309960

Fixes: b57dc7c13ea9 ("net/sched: Introduce action ct")
Signed-off-by: wenxu <wenxu@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 e9f3576..2eaabdc 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;
@@ -1012,6 +1015,7 @@ 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