net/sched: act_ct: Make tcf_ct_flow_table_restore_skb inline

Currently, tcf_ct_flow_table_restore_skb is exported by act_ct
module, therefore modules using it will have hard-dependency
on act_ct and will require loading it all the time.

This can lead to an unnecessary overhead on systems that do not
use hardware connection tracking action (ct_metadata action) in
the first place.

To relax the hard-dependency between the modules, we unexport this
function and make it a static inline one.

Fixes: 30b0cf90c6dd ("net/sched: act_ct: Support restoring conntrack info on skbs")
Signed-off-by: Alaa Hleihel <[e-mail]>
Reviewed-by: Roi Dayan <[e-mail]>
Acked-by: Marcelo Ricardo Leitner <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/net/tc_act/tc_ct.h

···
 #endif /* CONFIG_NF_CONNTRACK */
 
 #if IS_ENABLED(CONFIG_NET_ACT_CT)
-void tcf_ct_flow_table_restore_skb(struct sk_buff *skb, unsigned long cookie);
+static inline void
+tcf_ct_flow_table_restore_skb(struct sk_buff *skb, unsigned long cookie)
+{
+	enum ip_conntrack_info ctinfo = cookie & NFCT_INFOMASK;
+	struct nf_conn *ct;
+
+	ct = (struct nf_conn *)(cookie & NFCT_PTRMASK);
+	nf_conntrack_get(&ct->ct_general);
+	nf_ct_set(skb, ct, ctinfo);
+}
 #else
 static inline void
 tcf_ct_flow_table_restore_skb(struct sk_buff *skb, unsigned long cookie) { }

net/sched/act_ct.c

···
 	destroy_workqueue(act_ct_wq);
 }
 
-void tcf_ct_flow_table_restore_skb(struct sk_buff *skb, unsigned long cookie)
-{
-	enum ip_conntrack_info ctinfo = cookie & NFCT_INFOMASK;
-	struct nf_conn *ct;
-
-	ct = (struct nf_conn *)(cookie & NFCT_PTRMASK);
-	nf_conntrack_get(&ct->ct_general);
-	nf_ct_set(skb, ct, ctinfo);
-}
-EXPORT_SYMBOL_GPL(tcf_ct_flow_table_restore_skb);
-
 module_init(ct_init_module);
 module_exit(ct_cleanup_module);
 MODULE_AUTHOR("Paul Blakey <[e-mail]>");