xfrm: Const'ify address args to hash helpers.
[linux-3.10.git] / 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 __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 */