xfrm: dont assume rcu_read_lock in xfrm_output_one()
[linux-2.6.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(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 */