xref: /linux/net/xfrm/xfrm_hash.h (revision d524dac9279b6a41ffdf7ff7958c577f2e387db6)
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 */
131