netfilter: nat: include zone id in nat table hash again

Similar to the conntrack change, also use the zone id for the nat source
lists if the zone id is valid in both directions.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_nat_core.c

@@ -150,13 +150,16 @@ static void __nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl)
 
 /* We keep an extra hash for each conntrack, for fast searching. */
 static unsigned int
-hash_by_src(const struct net *n, const struct nf_conntrack_tuple *tuple)
+hash_by_src(const struct net *net,
+	    const struct nf_conntrack_zone *zone,
+	    const struct nf_conntrack_tuple *tuple)
 {
 	unsigned int hash;
 	struct {
 		struct nf_conntrack_man src;
 		u32 net_mix;
 		u32 protonum;
+		u32 zone;
 	} __aligned(SIPHASH_ALIGNMENT) combined;
 
 	get_random_once(&nf_nat_hash_rnd, sizeof(nf_nat_hash_rnd));
@@ -165,9 +168,13 @@ hash_by_src(const struct net *n, const struct nf_conntrack_tuple *tuple)
 
 	/* Original src, to ensure we map it consistently if poss. */
 	combined.src = tuple->src;
-	combined.net_mix = net_hash_mix(n);
+	combined.net_mix = net_hash_mix(net);
 	combined.protonum = tuple->dst.protonum;
 
+	/* Zone ID can be used provided its valid for both directions */
+	if (zone->dir == NF_CT_DEFAULT_ZONE_DIR)
+		combined.zone = zone->id;
+
 	hash = siphash(&combined, sizeof(combined), &nf_nat_hash_rnd);
 
 	return reciprocal_scale(hash, nf_nat_htable_size);
@@ -272,7 +279,7 @@ find_appropriate_src(struct net *net,
 		     struct nf_conntrack_tuple *result,
 		     const struct nf_nat_range2 *range)
 {
-	unsigned int h = hash_by_src(net, tuple);
+	unsigned int h = hash_by_src(net, zone, tuple);
 	const struct nf_conn *ct;
 
 	hlist_for_each_entry_rcu(ct, &nf_nat_bysource[h], nat_bysource) {
@@ -619,7 +626,7 @@ nf_nat_setup_info(struct nf_conn *ct,
 		unsigned int srchash;
 		spinlock_t *lock;
 
-		srchash = hash_by_src(net,
+		srchash = hash_by_src(net, nf_ct_zone(ct),
 				      &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 		lock = &nf_nat_locks[srchash % CONNTRACK_LOCKS];
 		spin_lock_bh(lock);
@@ -788,7 +795,7 @@ static void __nf_nat_cleanup_conntrack(struct nf_conn *ct)
 {
 	unsigned int h;
 
-	h = hash_by_src(nf_ct_net(ct), &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
+	h = hash_by_src(nf_ct_net(ct), nf_ct_zone(ct), &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 	spin_lock_bh(&nf_nat_locks[h % CONNTRACK_LOCKS]);
 	hlist_del_rcu(&ct->nat_bysource);
 	spin_unlock_bh(&nf_nat_locks[h % CONNTRACK_LOCKS]);