xfrm_hash.h

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#ifndef _XFRM_HASH_H
#define _XFRM_HASH_H

#include <linux/xfrm.h>
#include <linux/socket.h>

static inline unsigned int __xfrm4_addr_hash(const xfrm_address_t *addr)
{
    return ntohl(addr->a4);
}

static inline unsigned int __xfrm6_addr_hash(const xfrm_address_t *addr)
{
    return ntohl(addr->a6[2] ^ addr->a6[3]);
}

static inline unsigned int __xfrm4_daddr_saddr_hash(const xfrm_address_t *daddr,
                            const xfrm_address_t *saddr)
{
    u32 sum = (__force u32)daddr->a4 + (__force u32)saddr->a4;
    return ntohl((__force __be32)sum);
}

static inline unsigned int __xfrm6_daddr_saddr_hash(const xfrm_address_t *daddr,
                            const 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(const xfrm_address_t *daddr,
                       const 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 int __xfrm_src_hash(const xfrm_address_t *daddr,
                       const 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(const 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(const struct xfrm_selector *sel,
                      unsigned short family, unsigned int hmask)
{
    const xfrm_address_t *daddr = &sel->daddr;
    const 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(const xfrm_address_t *daddr,
                       const 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 */