release/src-rt-6.x.4708/linux/linux-2.6.36/net/xfrm/xfrm_hash.h

   1 #ifndef _XFRM_HASH_H
   2 #define _XFRM_HASH_H
   3
   4 #include <linux/xfrm.h>
   5 #include <linux/socket.h>
   6
   7 static inline unsigned int __xfrm4_addr_hash(xfrm_address_t *addr)
   8 {
   9         return ntohl(addr->a4);
  10 }
  11
  12 static inline unsigned int __xfrm6_addr_hash(xfrm_address_t *addr)
  13 {
  14         return ntohl(addr->a6[2] ^ addr->a6[3]);
  15 }
  16
  17 static inline unsigned int __xfrm4_daddr_saddr_hash(xfrm_address_t *daddr, xfrm_address_t *saddr)
  18 {
  19         u32 sum = (__force u32)daddr->a4 + (__force u32)saddr->a4;
  20         return ntohl((__force __be32)sum);
  21 }
  22
  23 static inline unsigned int __xfrm6_daddr_saddr_hash(xfrm_address_t *daddr, xfrm_address_t *saddr)
  24 {
  25         return ntohl(daddr->a6[2] ^ daddr->a6[3] ^
  26                      saddr->a6[2] ^ saddr->a6[3]);
  27 }
  28
  29 static inline unsigned int __xfrm_dst_hash(xfrm_address_t *daddr, xfrm_address_t *saddr,
  30                                            u32 reqid, unsigned short family,
  31                                            unsigned int hmask)
  32 {
  33         unsigned int h = family ^ reqid;
  34         switch (family) {
  35         case AF_INET:
  36                 h ^= __xfrm4_daddr_saddr_hash(daddr, saddr);
  37                 break;
  38         case AF_INET6:
  39                 h ^= __xfrm6_daddr_saddr_hash(daddr, saddr);
  40                 break;
  41         }
  42         return (h ^ (h >> 16)) & hmask;
  43 }
  44
  45 static inline unsigned __xfrm_src_hash(xfrm_address_t *daddr,
  46                                        xfrm_address_t *saddr,
  47                                        unsigned short family,
  48                                        unsigned int hmask)
  49 {
  50         unsigned int h = family;
  51         switch (family) {
  52         case AF_INET:
  53                 h ^= __xfrm4_daddr_saddr_hash(daddr, saddr);
  54                 break;
  55         case AF_INET6:
  56                 h ^= __xfrm6_daddr_saddr_hash(daddr, saddr);
  57                 break;
  58         }
  59         return (h ^ (h >> 16)) & hmask;
  60 }
  61
  62 static inline unsigned int
  63 __xfrm_spi_hash(xfrm_address_t *daddr, __be32 spi, u8 proto, unsigned short family,
  64                 unsigned int hmask)
  65 {
  66         unsigned int h = (__force u32)spi ^ proto;
  67         switch (family) {
  68         case AF_INET:
  69                 h ^= __xfrm4_addr_hash(daddr);
  70                 break;
  71         case AF_INET6:
  72                 h ^= __xfrm6_addr_hash(daddr);
  73                 break;
  74         }
  75         return (h ^ (h >> 10) ^ (h >> 20)) & hmask;
  76 }
  77
  78 static inline unsigned int __idx_hash(u32 index, unsigned int hmask)
  79 {
  80         return (index ^ (index >> 8)) & hmask;
  81 }
  82
  83 static inline unsigned int __sel_hash(struct xfrm_selector *sel, unsigned short family, unsigned int hmask)
  84 {
  85         xfrm_address_t *daddr = &sel->daddr;
  86         xfrm_address_t *saddr = &sel->saddr;
  87         unsigned int h = 0;
  88
  89         switch (family) {
  90         case AF_INET:
  91                 if (sel->prefixlen_d != 32 ||
  92                     sel->prefixlen_s != 32)
  93                         return hmask + 1;
  94
  95                 h = __xfrm4_daddr_saddr_hash(daddr, saddr);
  96                 break;
  97
  98         case AF_INET6:
  99                 if (sel->prefixlen_d != 128 ||
 100                     sel->prefixlen_s != 128)
 101                         return hmask + 1;
 102
 103                 h = __xfrm6_daddr_saddr_hash(daddr, saddr);
 104                 break;
 105         }
 106         h ^= (h >> 16);
 107         return h & hmask;
 108 }
 109
 110 static inline unsigned int __addr_hash(xfrm_address_t *daddr, xfrm_address_t *saddr, unsigned short family, unsigned int hmask)
 111 {
 112         unsigned int h = 0;
 113
 114         switch (family) {
 115         case AF_INET:
 116                 h = __xfrm4_daddr_saddr_hash(daddr, saddr);
 117                 break;
 118
 119         case AF_INET6:
 120                 h = __xfrm6_daddr_saddr_hash(daddr, saddr);
 121                 break;
 122         }
 123         h ^= (h >> 16);
 124         return h & hmask;
 125 }
 126
 127 extern struct hlist_head *xfrm_hash_alloc(unsigned int sz);
 128 extern void xfrm_hash_free(struct hlist_head *n, unsigned int sz);
 129
 130 #endif /* _XFRM_HASH_H */