1 files changed, 38 insertions, 0 deletions

diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 8dfd5a691e5f..2e5814a84360 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -190,6 +190,44 @@ sherry_cache:
 }
 EXPORT_SYMBOL_GPL(__inet_lookup_listener);
 
+struct sock * __inet_lookup_established(struct inet_hashinfo *hashinfo,
+                                  const __be32 saddr, const __be16 sport,
+                                  const __be32 daddr, const u16 hnum,
+                                  const int dif)
+{
+        INET_ADDR_COOKIE(acookie, saddr, daddr)
+        const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
+        struct sock *sk;
+        const struct hlist_node *node;
+        /* Optimize here for direct hit, only listening connections can
+         * have wildcards anyways.
+         */
+        unsigned int hash = inet_ehashfn(daddr, hnum, saddr, sport);
+        struct inet_ehash_bucket *head = inet_ehash_bucket(hashinfo, hash);
+        rwlock_t *lock = inet_ehash_lockp(hashinfo, hash);
+
+        prefetch(head->chain.first);
+        read_lock(lock);
+        sk_for_each(sk, node, &head->chain) {
+                if (INET_MATCH(sk, hash, acookie, saddr, daddr, ports, dif))
+                        goto hit; /* You sunk my battleship! */
+        }
+
+        /* Must check for a TIME_WAIT'er before going to listener hash. */
+        sk_for_each(sk, node, &head->twchain) {
+                if (INET_TW_MATCH(sk, hash, acookie, saddr, daddr, ports, dif))
+                        goto hit;
+        }
+        sk = NULL;
+out:
+        read_unlock(lock);
+        return sk;
+hit:
+        sock_hold(sk);
+        goto out;
+}
+EXPORT_SYMBOL_GPL(__inet_lookup_established);
+
 /* called with local bh disabled */
 static int __inet_check_established(struct inet_timewait_death_row *death_row,
                                     struct sock *sk, __u16 lport,