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 #include <linux/jhash.h>
   7
   8 static inline unsigned int __xfrm4_addr_hash(const xfrm_address_t *addr)
   9 {
  10         return ntohl(addr->a4);
  11 }
  12
  13 static inline unsigned int __xfrm6_addr_hash(const xfrm_address_t *addr)
  14 {
  15         return ntohl(addr->a6[2] ^ addr->a6[3]);
  16 }
  17
  18 static inline unsigned int __xfrm4_daddr_saddr_hash(const xfrm_address_t *daddr,
  19                                                     const xfrm_address_t *saddr)
  20 {
  21         u32 sum = (__force u32)daddr->a4 + (__force u32)saddr->a4;
  22         return ntohl((__force __be32)sum);
  23 }
  24
  25 static inline unsigned int __xfrm6_daddr_saddr_hash(const xfrm_address_t *daddr,
  26                                                     const xfrm_address_t *saddr)
  27 {
  28         return ntohl(daddr->a6[2] ^ daddr->a6[3] ^
  29                      saddr->a6[2] ^ saddr->a6[3]);
  30 }
  31
  32 static inline u32 __bits2mask32(__u8 bits)
  33 {
  34         u32 mask32 = 0xffffffff;
  35
  36         if (bits == 0)
  37                 mask32 = 0;
  38         else if (bits < 32)
  39                 mask32 <<= (32 - bits);
  40
  41         return mask32;
  42 }
  43
  44 static inline unsigned int __xfrm4_dpref_spref_hash(const xfrm_address_t *daddr,
  45                                                     const xfrm_address_t *saddr,
  46                                                     __u8 dbits,
  47                                                     __u8 sbits)
  48 {
  49         return jhash_2words(ntohl(daddr->a4) & __bits2mask32(dbits),
  50                             ntohl(saddr->a4) & __bits2mask32(sbits),
  51                             0);
  52 }
  53
  54 static inline unsigned int __xfrm6_pref_hash(const xfrm_address_t *addr,
  55                                              __u8 prefixlen)
  56 {
  57         unsigned int pdw;
  58         unsigned int pbi;
  59         u32 initval = 0;
  60
  61         pdw = prefixlen >> 5;     /* num of whole u32 in prefix */
  62         pbi = prefixlen &  0x1f;  /* num of bits in incomplete u32 in prefix */
  63
  64         if (pbi) {
  65                 __be32 mask;
  66
  67                 mask = htonl((0xffffffff) << (32 - pbi));
  68
  69                 initval = (__force u32)(addr->a6[pdw] & mask);
  70         }
  71
  72         return jhash2((__force u32 *)addr->a6, pdw, initval);
  73 }
  74
  75 static inline unsigned int __xfrm6_dpref_spref_hash(const xfrm_address_t *daddr,
  76                                                     const xfrm_address_t *saddr,
  77                                                     __u8 dbits,
  78                                                     __u8 sbits)
  79 {
  80         return __xfrm6_pref_hash(daddr, dbits) ^
  81                __xfrm6_pref_hash(saddr, sbits);
  82 }
  83
  84 static inline unsigned int __xfrm_dst_hash(const xfrm_address_t *daddr,
  85                                            const xfrm_address_t *saddr,
  86                                            u32 reqid, unsigned short family,
  87                                            unsigned int hmask)
  88 {
  89         unsigned int h = family ^ reqid;
  90         switch (family) {
  91         case AF_INET:
  92                 h ^= __xfrm4_daddr_saddr_hash(daddr, saddr);
  93                 break;
  94         case AF_INET6:
  95                 h ^= __xfrm6_daddr_saddr_hash(daddr, saddr);
  96                 break;
  97         }
  98         return (h ^ (h >> 16)) & hmask;
  99 }
 100
 101 static inline unsigned int __xfrm_src_hash(const xfrm_address_t *daddr,
 102                                            const xfrm_address_t *saddr,
 103                                            unsigned short family,
 104                                            unsigned int hmask)
 105 {
 106         unsigned int h = family;
 107         switch (family) {
 108         case AF_INET:
 109                 h ^= __xfrm4_daddr_saddr_hash(daddr, saddr);
 110                 break;
 111         case AF_INET6:
 112                 h ^= __xfrm6_daddr_saddr_hash(daddr, saddr);
 113                 break;
 114         }
 115         return (h ^ (h >> 16)) & hmask;
 116 }
 117
 118 static inline unsigned int
 119 __xfrm_spi_hash(const xfrm_address_t *daddr, __be32 spi, u8 proto,
 120                 unsigned short family, unsigned int hmask)
 121 {
 122         unsigned int h = (__force u32)spi ^ proto;
 123         switch (family) {
 124         case AF_INET:
 125                 h ^= __xfrm4_addr_hash(daddr);
 126                 break;
 127         case AF_INET6:
 128                 h ^= __xfrm6_addr_hash(daddr);
 129                 break;
 130         }
 131         return (h ^ (h >> 10) ^ (h >> 20)) & hmask;
 132 }
 133
 134 static inline unsigned int __idx_hash(u32 index, unsigned int hmask)
 135 {
 136         return (index ^ (index >> 8)) & hmask;
 137 }
 138
 139 static inline unsigned int __sel_hash(const struct xfrm_selector *sel,
 140                                       unsigned short family, unsigned int hmask,
 141                                       u8 dbits, u8 sbits)
 142 {
 143         const xfrm_address_t *daddr = &sel->daddr;
 144         const xfrm_address_t *saddr = &sel->saddr;
 145         unsigned int h = 0;
 146
 147         switch (family) {
 148         case AF_INET:
 149                 if (sel->prefixlen_d < dbits ||
 150                     sel->prefixlen_s < sbits)
 151                         return hmask + 1;
 152
 153                 h = __xfrm4_dpref_spref_hash(daddr, saddr, dbits, sbits);
 154                 break;
 155
 156         case AF_INET6:
 157                 if (sel->prefixlen_d < dbits ||
 158                     sel->prefixlen_s < sbits)
 159                         return hmask + 1;
 160
 161                 h = __xfrm6_dpref_spref_hash(daddr, saddr, dbits, sbits);
 162                 break;
 163         }
 164         h ^= (h >> 16);
 165         return h & hmask;
 166 }
 167
 168 static inline unsigned int __addr_hash(const xfrm_address_t *daddr,
 169                                        const xfrm_address_t *saddr,
 170                                        unsigned short family,
 171                                        unsigned int hmask,
 172                                        u8 dbits, u8 sbits)
 173 {
 174         unsigned int h = 0;
 175
 176         switch (family) {
 177         case AF_INET:
 178                 h = __xfrm4_dpref_spref_hash(daddr, saddr, dbits, sbits);
 179                 break;
 180
 181         case AF_INET6:
 182                 h = __xfrm6_dpref_spref_hash(daddr, saddr, dbits, sbits);
 183                 break;
 184         }
 185         h ^= (h >> 16);
 186         return h & hmask;
 187 }
 188
 189 struct hlist_head *xfrm_hash_alloc(unsigned int sz);
 190 void xfrm_hash_free(struct hlist_head *n, unsigned int sz);
 191
 192 #endif /* _XFRM_HASH_H */