netfilter: conntrack: use nf_ct_key_equal() in more places

This prepares for upcoming change that places all conntracks into a
single, global table. For this to work we will need to also compare
net pointer during lookup. To avoid open-coding such check use the
nf_ct_key_equal helper and then later extend it to also consider net_eq.

Signed-off-by: Florian Westphal <[e-mail]>
Signed-off-by: Pablo Neira Ayuso <[e-mail]>

net/netfilter/nf_conntrack_core.c

···
 
 	/* See if there's one in the list already, including reverse */
 	hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
-		if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
-				      &h->tuple) &&
-		    nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
-				     NF_CT_DIRECTION(h)))
+		if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
+				    zone))
 			goto out;
+
 	hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
-		if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
-				      &h->tuple) &&
-		    nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
-				     NF_CT_DIRECTION(h)))
+		if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
+				    zone))
 			goto out;
 
 	add_timer(&ct->timeout);
···
 	   NAT could have grabbed it without realizing, since we're
 	   not in the hash.  If there is, we lost race. */
 	hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
-		if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
-				      &h->tuple) &&
-		    nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
-				     NF_CT_DIRECTION(h)))
+		if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
+				    zone))
 			goto out;
+
 	hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
-		if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
-				      &h->tuple) &&
-		    nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
-				     NF_CT_DIRECTION(h)))
+		if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
+				    zone))
 			goto out;
 
 	/* Timer relative to confirmation time, not original
···
 	hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[hash], hnnode) {
 		ct = nf_ct_tuplehash_to_ctrack(h);
 		if (ct != ignored_conntrack &&
-		    nf_ct_tuple_equal(tuple, &h->tuple) &&
-		    nf_ct_zone_equal(ct, zone, NF_CT_DIRECTION(h))) {
+		    nf_ct_key_equal(h, tuple, zone)) {
 			NF_CT_STAT_INC_ATOMIC(net, found);
 			rcu_read_unlock();
 			return 1;