net/sched: act_ct: enable stats for HW offloaded entries

By setting NF_FLOWTABLE_COUNTER. Otherwise, the updates added by
commit ef803b3 ("netfilter: flowtable: add counter support in HW
offload") are not effective when using act_ct.

While at it, now that we have the flag set, protect the call to
nf_ct_acct_update() by commit beb97d3 ("net/sched: act_ct: update
nf_conn_acct for act_ct SW offload in flowtable") with the check on
NF_FLOWTABLE_COUNTER, as also done on other places.

Note that this shouldn't impact performance as these stats are only
enabled when net.netfilter.nf_conntrack_acct is enabled.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: wenxu <wenxu@ucloud.cn>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Link: https://lore.kernel.org/r/481a65741261fd81b0a0813e698af163477467ec.1606415787.git.marcelo.leitner@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/sched/act_ct.c

@@ -296,7 +296,8 @@ static int tcf_ct_flow_table_get(struct tcf_ct_params *params)
 		goto err_insert;
 
 	ct_ft->nf_ft.type = &flowtable_ct;
-	ct_ft->nf_ft.flags |= NF_FLOWTABLE_HW_OFFLOAD;
+	ct_ft->nf_ft.flags |= NF_FLOWTABLE_HW_OFFLOAD |
+			      NF_FLOWTABLE_COUNTER;
 	err = nf_flow_table_init(&ct_ft->nf_ft);
 	if (err)
 		goto err_init;
@@ -540,7 +541,8 @@ static bool tcf_ct_flow_table_lookup(struct tcf_ct_params *p,
 	flow_offload_refresh(nf_ft, flow);
 	nf_conntrack_get(&ct->ct_general);
 	nf_ct_set(skb, ct, ctinfo);
-	nf_ct_acct_update(ct, dir, skb->len);
+	if (nf_ft->flags & NF_FLOWTABLE_COUNTER)
+		nf_ct_acct_update(ct, dir, skb->len);
 
 	return true;
 }