1 files changed, 32 insertions, 3 deletions

diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 95fac5532994..bfc39066e730 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -124,8 +124,10 @@ EXPORT_SYMBOL(inet_listen_wlock);
  * remote address for the connection. So always assume those are both
  * wildcarded during the search since they can never be otherwise.
  */
-struct sock *__inet_lookup_listener(const struct hlist_head *head, const u32 daddr,
-                                    const unsigned short hnum, const int dif)
+static struct sock *__inet_lookup_listener(const struct hlist_head *head,
+                                           const u32 daddr,
+                                           const unsigned short hnum,
+                                           const int dif)
 {
         struct sock *result = NULL, *sk;
         const struct hlist_node *node;
@@ -159,7 +161,34 @@ struct sock *__inet_lookup_listener(const struct hlist_head *head, const u32 dad
         return result;
 }
 
-EXPORT_SYMBOL_GPL(__inet_lookup_listener);
+/* Optimize the common listener case. */
+struct sock *inet_lookup_listener(struct inet_hashinfo *hashinfo,
+                                  const u32 daddr, const unsigned short hnum,
+                                  const int dif)
+{
+        struct sock *sk = NULL;
+        const struct hlist_head *head;
+
+        read_lock(&hashinfo->lhash_lock);
+        head = &hashinfo->listening_hash[inet_lhashfn(hnum)];
+        if (!hlist_empty(head)) {
+                const struct inet_sock *inet = inet_sk((sk = __sk_head(head)));
+
+                if (inet->num == hnum && !sk->sk_node.next &&
+                    (!inet->rcv_saddr || inet->rcv_saddr == daddr) &&
+                    (sk->sk_family == PF_INET || !ipv6_only_sock(sk)) &&
+                    !sk->sk_bound_dev_if)
+                        goto sherry_cache;
+                sk = __inet_lookup_listener(head, daddr, hnum, dif);
+        }
+        if (sk) {
+sherry_cache:
+                sock_hold(sk);
+        }
+        read_unlock(&hashinfo->lhash_lock);
+        return sk;
+}
+EXPORT_SYMBOL_GPL(inet_lookup_listener);
 
 /* called with local bh disabled */
 static int __inet_check_established(struct inet_timewait_death_row *death_row,