udp: introduce a udp_hashfn function

Currently the chain to store a UDP socket is calculated with
simple (x & (UDP_HTABLE_SIZE - 1)). But taking net into account
would make this calculation a bit more complex, so moving it into
a function would help.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 6 deletions

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index eba790dcd16b..d8f527d15701 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -134,7 +134,7 @@ static inline int __udp_lib_lport_inuse(struct net *net, __u16 num,
         struct sock *sk;
         struct hlist_node *node;
 
-        sk_for_each(sk, node, &udptable[num & (UDP_HTABLE_SIZE - 1)])
+        sk_for_each(sk, node, &udptable[udp_hashfn(num)])
                 if (net_eq(sock_net(sk), net) && sk->sk_hash == num)
                         return 1;
         return 0;
@@ -174,7 +174,7 @@ int udp_lib_get_port(struct sock *sk, unsigned short snum,
                 for (i = 0; i < UDP_HTABLE_SIZE; i++) {
                         int size = 0;
 
-                        head = &udptable[rover & (UDP_HTABLE_SIZE - 1)];
+                        head = &udptable[udp_hashfn(rover)];
                         if (hlist_empty(head))
                                 goto gotit;
 
@@ -211,7 +211,7 @@ int udp_lib_get_port(struct sock *sk, unsigned short snum,
 gotit:
                 snum = rover;
         } else {
-                head = &udptable[snum & (UDP_HTABLE_SIZE - 1)];
+                head = &udptable[udp_hashfn(snum)];
 
                 sk_for_each(sk2, node, head)
                         if (sk2->sk_hash == snum                             &&
@@ -227,7 +227,7 @@ gotit:
         inet_sk(sk)->num = snum;
         sk->sk_hash = snum;
         if (sk_unhashed(sk)) {
-                head = &udptable[snum & (UDP_HTABLE_SIZE - 1)];
+                head = &udptable[udp_hashfn(snum)];
                 sk_add_node(sk, head);
                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
         }
@@ -264,7 +264,7 @@ static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
         int badness = -1;
 
         read_lock(&udp_hash_lock);
-        sk_for_each(sk, node, &udptable[hnum & (UDP_HTABLE_SIZE - 1)]) {
+        sk_for_each(sk, node, &udptable[udp_hashfn(hnum)]) {
                 struct inet_sock *inet = inet_sk(sk);
 
                 if (net_eq(sock_net(sk), net) && sk->sk_hash == hnum &&
@@ -1068,7 +1068,7 @@ static int __udp4_lib_mcast_deliver(struct sk_buff *skb,
         int dif;
 
         read_lock(&udp_hash_lock);
-        sk = sk_head(&udptable[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)]);
+        sk = sk_head(&udptable[udp_hashfn(ntohs(uh->dest))]);
         dif = skb->dev->ifindex;
         sk = udp_v4_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif);
         if (sk) {