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>

diff --git a/include/linux/udp.h b/include/linux/udp.h
index 581ca2c..9c94312 100644 (file)
--- a/include/linux/udp.h
+++ b/include/linux/udp.h
@@ -46,6 +46,11 @@ static inline struct udphdr *udp_hdr(const struct sk_buff *skb)
 
 #define UDP_HTABLE_SIZE                128
 
+static inline int udp_hashfn(const unsigned num)
+{
+       return num & (UDP_HTABLE_SIZE - 1);
+}
+
 struct udp_sock {
        /* inet_sock has to be the first member */
        struct inet_sock inet;

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index eba790d..d8f527d 100644 (file)
--- 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) {

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 09687f7..6e4a822 100644 (file)
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -65,7 +65,7 @@ static struct sock *__udp6_lib_lookup(struct net *net,
        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 &&
@@ -361,7 +361,7 @@ static int __udp6_lib_mcast_deliver(struct sk_buff *skb, struct in6_addr *saddr,
        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 = inet6_iif(skb);
        sk = udp_v6_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif);
        if (!sk) {