udp: bind() optimisation

UDP bind() can be O(N^2) in some pathological cases.

Thanks to secondary hash tables, we can make it O(N)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 8 insertions, 1 deletions

diff --git a/include/linux/udp.h b/include/linux/udp.h
index 59f0ddf2d284..03f72a2ba028 100644
--- a/include/linux/udp.h
+++ b/include/linux/udp.h
@@ -88,6 +88,12 @@ static inline struct udp_sock *udp_sk(const struct sock *sk)
         return (struct udp_sock *)sk;
 }
 
+#define udp_portaddr_for_each_entry(__sk, node, list) \
+        hlist_nulls_for_each_entry(__sk, node, list, __sk_common.skc_portaddr_node)
+
+#define udp_portaddr_for_each_entry_rcu(__sk, node, list) \
+        hlist_nulls_for_each_entry_rcu(__sk, node, list, __sk_common.skc_portaddr_node)
+
 #define IS_UDPLITE(__sk) (udp_sk(__sk)->pcflag)
 
 #endif
diff --git a/include/net/udp.h b/include/net/udp.h
index af41850f742a..5348d80b25bb 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -158,7 +158,8 @@ static inline void udp_lib_close(struct sock *sk, long timeout)
 }
 
 extern int      udp_lib_get_port(struct sock *sk, unsigned short snum,
-                int (*)(const struct sock*,const struct sock*));
+                int (*)(const struct sock *,const struct sock *),
+                unsigned int hash2_nulladdr);
 
 /* net/ipv4/udp.c */
 extern int      udp_get_port(struct sock *sk, unsigned short snum,