aha/net/xfrm/xfrm_hash.h
Jussi Mäki b79a79471b Fix xfrm hash collisions by changing __xfrm4_daddr_saddr_hash to hash addresses with addition
This patch fixes hash collisions in cases where number
of entries have incrementing IP source and destination addresses
from single respective subnets (i.e. 192.168.0.1-172.16.0.1,
192.168.0.2-172.16.0.2, and so on.).

Signed-off-by: Jussi Maki <joamaki@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-09 21:45:31 -07:00

129 lines
2.9 KiB
C

#ifndef _XFRM_HASH_H
#define _XFRM_HASH_H
#include <linux/xfrm.h>
#include <linux/socket.h>
static inline unsigned int __xfrm4_addr_hash(xfrm_address_t *addr)
{
return ntohl(addr->a4);
}
static inline unsigned int __xfrm6_addr_hash(xfrm_address_t *addr)
{
return ntohl(addr->a6[2] ^ addr->a6[3]);
}
static inline unsigned int __xfrm4_daddr_saddr_hash(xfrm_address_t *daddr, xfrm_address_t *saddr)
{
return ntohl(daddr->a4 + saddr->a4);
}
static inline unsigned int __xfrm6_daddr_saddr_hash(xfrm_address_t *daddr, xfrm_address_t *saddr)
{
return ntohl(daddr->a6[2] ^ daddr->a6[3] ^
saddr->a6[2] ^ saddr->a6[3]);
}
static inline unsigned int __xfrm_dst_hash(xfrm_address_t *daddr, xfrm_address_t *saddr,
u32 reqid, unsigned short family,
unsigned int hmask)
{
unsigned int h = family ^ reqid;
switch (family) {
case AF_INET:
h ^= __xfrm4_daddr_saddr_hash(daddr, saddr);
break;
case AF_INET6:
h ^= __xfrm6_daddr_saddr_hash(daddr, saddr);
break;
}
return (h ^ (h >> 16)) & hmask;
}
static inline unsigned __xfrm_src_hash(xfrm_address_t *daddr,
xfrm_address_t *saddr,
unsigned short family,
unsigned int hmask)
{
unsigned int h = family;
switch (family) {
case AF_INET:
h ^= __xfrm4_daddr_saddr_hash(daddr, saddr);
break;
case AF_INET6:
h ^= __xfrm6_daddr_saddr_hash(daddr, saddr);
break;
};
return (h ^ (h >> 16)) & hmask;
}
static inline unsigned int
__xfrm_spi_hash(xfrm_address_t *daddr, __be32 spi, u8 proto, unsigned short family,
unsigned int hmask)
{
unsigned int h = (__force u32)spi ^ proto;
switch (family) {
case AF_INET:
h ^= __xfrm4_addr_hash(daddr);
break;
case AF_INET6:
h ^= __xfrm6_addr_hash(daddr);
break;
}
return (h ^ (h >> 10) ^ (h >> 20)) & hmask;
}
static inline unsigned int __idx_hash(u32 index, unsigned int hmask)
{
return (index ^ (index >> 8)) & hmask;
}
static inline unsigned int __sel_hash(struct xfrm_selector *sel, unsigned short family, unsigned int hmask)
{
xfrm_address_t *daddr = &sel->daddr;
xfrm_address_t *saddr = &sel->saddr;
unsigned int h = 0;
switch (family) {
case AF_INET:
if (sel->prefixlen_d != 32 ||
sel->prefixlen_s != 32)
return hmask + 1;
h = __xfrm4_daddr_saddr_hash(daddr, saddr);
break;
case AF_INET6:
if (sel->prefixlen_d != 128 ||
sel->prefixlen_s != 128)
return hmask + 1;
h = __xfrm6_daddr_saddr_hash(daddr, saddr);
break;
};
h ^= (h >> 16);
return h & hmask;
}
static inline unsigned int __addr_hash(xfrm_address_t *daddr, xfrm_address_t *saddr, unsigned short family, unsigned int hmask)
{
unsigned int h = 0;
switch (family) {
case AF_INET:
h = __xfrm4_daddr_saddr_hash(daddr, saddr);
break;
case AF_INET6:
h = __xfrm6_daddr_saddr_hash(daddr, saddr);
break;
};
h ^= (h >> 16);
return h & hmask;
}
extern struct hlist_head *xfrm_hash_alloc(unsigned int sz);
extern void xfrm_hash_free(struct hlist_head *n, unsigned int sz);
#endif /* _XFRM_HASH_H */