From ddbe503203855939946430e39bae58de11b70b69 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 18 Jul 2012 08:11:12 +0000 Subject: ipv6: add ipv6_addr_hash() helper Introduce ipv6_addr_hash() helper doing a XOR on all bits of an IPv6 address, with an optimized x86_64 version. Use it in flow dissector, as suggested by Andrew McGregor, to reduce hash collision probabilities in fq_codel (and other users of flow dissector) Use it in ip6_tunnel.c and use more bit shuffling, as suggested by David Laight, as existing hash was ignoring most of them. Use it in sunrpc and use more bit shuffling, using hash_32(). Use it in net/ipv6/addrconf.c, using hash_32() as well. As a cleanup, use it in net/ipv4/tcp_metrics.c Signed-off-by: Eric Dumazet Reported-by: Andrew McGregor Cc: Dave Taht Cc: Tom Herbert Cc: David Laight Cc: Joe Perches Signed-off-by: David S. Miller --- net/ipv6/ip6_tunnel.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) (limited to 'net/ipv6/ip6_tunnel.c') diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index db32846..9a1d5fe 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -40,6 +40,7 @@ #include #include #include +#include #include #include @@ -70,11 +71,15 @@ MODULE_ALIAS_NETDEV("ip6tnl0"); #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK) #define IPV6_TCLASS_SHIFT 20 -#define HASH_SIZE 32 +#define HASH_SIZE_SHIFT 5 +#define HASH_SIZE (1 << HASH_SIZE_SHIFT) -#define HASH(addr) ((__force u32)((addr)->s6_addr32[0] ^ (addr)->s6_addr32[1] ^ \ - (addr)->s6_addr32[2] ^ (addr)->s6_addr32[3]) & \ - (HASH_SIZE - 1)) +static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2) +{ + u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2); + + return hash_32(hash, HASH_SIZE_SHIFT); +} static int ip6_tnl_dev_init(struct net_device *dev); static void ip6_tnl_dev_setup(struct net_device *dev); @@ -166,12 +171,11 @@ static inline void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst) static struct ip6_tnl * ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local) { - unsigned int h0 = HASH(remote); - unsigned int h1 = HASH(local); + unsigned int hash = HASH(remote, local); struct ip6_tnl *t; struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); - for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[h0 ^ h1]) { + for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) { if (ipv6_addr_equal(local, &t->parms.laddr) && ipv6_addr_equal(remote, &t->parms.raddr) && (t->dev->flags & IFF_UP)) @@ -205,7 +209,7 @@ ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct ip6_tnl_parm *p) if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) { prio = 1; - h = HASH(remote) ^ HASH(local); + h = HASH(remote, local); } return &ip6n->tnls[prio][h]; } -- cgit v1.1