xref: /openbmc/linux/net/xfrm/xfrm_hash.h (revision 95e9fd10)
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 */
137