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(const xfrm_address_t *addr)
   8 {
   9         return ntohl(addr->a4);
  10 }
  11
  12 static inline unsigned int __xfrm6_addr_hash(const 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(const xfrm_address_t *daddr,
  18                                                     const xfrm_address_t *saddr)
  19 {
  20         u32 sum = (__force u32)daddr->a4 + (__force u32)saddr->a4;
  21         return ntohl((__force __be32)sum);
  22 }
  23
  24 static inline unsigned int __xfrm6_daddr_saddr_hash(const xfrm_address_t *daddr,
  25                                                     const xfrm_address_t *saddr)
  26 {
  27         return ntohl(daddr->a6[2] ^ daddr->a6[3] ^
  28                      saddr->a6[2] ^ saddr->a6[3]);
  29 }
  30
  31 static inline unsigned int __xfrm_dst_hash(const xfrm_address_t *daddr,
  32                                            const xfrm_address_t *saddr,
  33                                            u32 reqid, unsigned short family,
  34                                            unsigned int hmask)
  35 {
  36         unsigned int h = family ^ reqid;
  37         switch (family) {
  38         case AF_INET:
  39                 h ^= __xfrm4_daddr_saddr_hash(daddr, saddr);
  40                 break;
  41         case AF_INET6:
  42                 h ^= __xfrm6_daddr_saddr_hash(daddr, saddr);
  43                 break;
  44         }
  45         return (h ^ (h >> 16)) & hmask;
  46 }
  47
  48 static inline unsigned int __xfrm_src_hash(const xfrm_address_t *daddr,
  49                                            const xfrm_address_t *saddr,
  50                                            unsigned short family,
  51                                            unsigned int hmask)
  52 {
  53         unsigned int h = family;
  54         switch (family) {
  55         case AF_INET:
  56                 h ^= __xfrm4_daddr_saddr_hash(daddr, saddr);
  57                 break;
  58         case AF_INET6:
  59                 h ^= __xfrm6_daddr_saddr_hash(daddr, saddr);
  60                 break;
  61         }
  62         return (h ^ (h >> 16)) & hmask;
  63 }
  64
  65 static inline unsigned int
  66 __xfrm_spi_hash(const xfrm_address_t *daddr, __be32 spi, u8 proto,
  67                 unsigned short family, unsigned int hmask)
  68 {
  69         unsigned int h = (__force u32)spi ^ proto;
  70         switch (family) {
  71         case AF_INET:
  72                 h ^= __xfrm4_addr_hash(daddr);
  73                 break;
  74         case AF_INET6:
  75                 h ^= __xfrm6_addr_hash(daddr);
  76                 break;
  77         }
  78         return (h ^ (h >> 10) ^ (h >> 20)) & hmask;
  79 }
  80
  81 static inline unsigned int __idx_hash(u32 index, unsigned int hmask)
  82 {
  83         return (index ^ (index >> 8)) & hmask;
  84 }
  85
  86 static inline unsigned int __sel_hash(const struct xfrm_selector *sel,
  87                                       unsigned short family, unsigned int hmask)
  88 {
  89         const xfrm_address_t *daddr = &sel->daddr;
  90         const xfrm_address_t *saddr = &sel->saddr;
  91         unsigned int h = 0;
  92
  93         switch (family) {
  94         case AF_INET:
  95                 if (sel->prefixlen_d != 32 ||
  96                     sel->prefixlen_s != 32)
  97                         return hmask + 1;
  98
  99                 h = __xfrm4_daddr_saddr_hash(daddr, saddr);
 100                 break;
 101
 102         case AF_INET6:
 103                 if (sel->prefixlen_d != 128 ||
 104                     sel->prefixlen_s != 128)
 105                         return hmask + 1;
 106
 107                 h = __xfrm6_daddr_saddr_hash(daddr, saddr);
 108                 break;
 109         }
 110         h ^= (h >> 16);
 111         return h & hmask;
 112 }
 113
 114 static inline unsigned int __addr_hash(const xfrm_address_t *daddr,
 115                                        const xfrm_address_t *saddr,
 116                                        unsigned short family, unsigned int hmask)
 117 {
 118         unsigned int h = 0;
 119
 120         switch (family) {
 121         case AF_INET:
 122                 h = __xfrm4_daddr_saddr_hash(daddr, saddr);
 123                 break;
 124
 125         case AF_INET6:
 126                 h = __xfrm6_daddr_saddr_hash(daddr, saddr);
 127                 break;
 128         }
 129         h ^= (h >> 16);
 130         return h & hmask;
 131 }
 132
 133 extern struct hlist_head *xfrm_hash_alloc(unsigned int sz);
 134 extern void xfrm_hash_free(struct hlist_head *n, unsigned int sz);
 135
 136 #endif /* _XFRM_HASH_H */