From d4cada4ae1c012815f95fa507eb86a0ae9d607d7 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sun, 8 Nov 2009 10:17:30 +0000 Subject: udp: split sk_hash into two u16 hashes Union sk_hash with two u16 hashes for udp (no extra memory taken) One 16 bits hash on (local port) value (the previous udp 'hash') One 16 bits hash on (local address, local port) values, initialized but not yet used. This second hash is using jenkin hash for better distribution. Because the 'port' is xored later, a partial hash is performed on local address + net_hash_mix(net) Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv6/udp.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 5bc7cdb..1e5fadd 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -81,8 +81,30 @@ int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2) return 0; } +static unsigned int udp6_portaddr_hash(struct net *net, + const struct in6_addr *addr6, + unsigned int port) +{ + unsigned int hash, mix = net_hash_mix(net); + + if (ipv6_addr_any(addr6)) + hash = jhash_1word(0, mix); + else if (ipv6_addr_type(addr6) == IPV6_ADDR_MAPPED) + hash = jhash_1word(addr6->s6_addr32[3], mix); + else + hash = jhash2(addr6->s6_addr32, 4, mix); + + return hash ^ port; +} + + int udp_v6_get_port(struct sock *sk, unsigned short snum) { + /* precompute partial secondary hash */ + udp_sk(sk)->udp_portaddr_hash = + udp6_portaddr_hash(sock_net(sk), + &inet6_sk(sk)->rcv_saddr, + 0); return udp_lib_get_port(sk, snum, ipv6_rcv_saddr_equal); } @@ -94,7 +116,7 @@ static inline int compute_score(struct sock *sk, struct net *net, { int score = -1; - if (net_eq(sock_net(sk), net) && sk->sk_hash == hnum && + if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum && sk->sk_family == PF_INET6) { struct ipv6_pinfo *np = inet6_sk(sk); struct inet_sock *inet = inet_sk(sk); @@ -415,7 +437,8 @@ static struct sock *udp_v6_mcast_next(struct net *net, struct sock *sk, if (!net_eq(sock_net(s), net)) continue; - if (s->sk_hash == num && s->sk_family == PF_INET6) { + if (udp_sk(s)->udp_port_hash == num && + s->sk_family == PF_INET6) { struct ipv6_pinfo *np = inet6_sk(s); if (inet->inet_dport) { if (inet->inet_dport != rmt_port) -- cgit v1.1