xref: /openbmc/linux/net/xfrm/xfrm_hash.h (revision a09d2831)
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 	return ntohl(daddr->a4 + saddr->a4);
20 }
21 
22 static inline unsigned int __xfrm6_daddr_saddr_hash(xfrm_address_t *daddr, xfrm_address_t *saddr)
23 {
24 	return ntohl(daddr->a6[2] ^ daddr->a6[3] ^
25 		     saddr->a6[2] ^ saddr->a6[3]);
26 }
27 
28 static inline unsigned int __xfrm_dst_hash(xfrm_address_t *daddr, xfrm_address_t *saddr,
29 					   u32 reqid, unsigned short family,
30 					   unsigned int hmask)
31 {
32 	unsigned int h = family ^ reqid;
33 	switch (family) {
34 	case AF_INET:
35 		h ^= __xfrm4_daddr_saddr_hash(daddr, saddr);
36 		break;
37 	case AF_INET6:
38 		h ^= __xfrm6_daddr_saddr_hash(daddr, saddr);
39 		break;
40 	}
41 	return (h ^ (h >> 16)) & hmask;
42 }
43 
44 static inline unsigned __xfrm_src_hash(xfrm_address_t *daddr,
45 				       xfrm_address_t *saddr,
46 				       unsigned short family,
47 				       unsigned int hmask)
48 {
49 	unsigned int h = family;
50 	switch (family) {
51 	case AF_INET:
52 		h ^= __xfrm4_daddr_saddr_hash(daddr, saddr);
53 		break;
54 	case AF_INET6:
55 		h ^= __xfrm6_daddr_saddr_hash(daddr, saddr);
56 		break;
57 	};
58 	return (h ^ (h >> 16)) & hmask;
59 }
60 
61 static inline unsigned int
62 __xfrm_spi_hash(xfrm_address_t *daddr, __be32 spi, u8 proto, unsigned short family,
63 		unsigned int hmask)
64 {
65 	unsigned int h = (__force u32)spi ^ proto;
66 	switch (family) {
67 	case AF_INET:
68 		h ^= __xfrm4_addr_hash(daddr);
69 		break;
70 	case AF_INET6:
71 		h ^= __xfrm6_addr_hash(daddr);
72 		break;
73 	}
74 	return (h ^ (h >> 10) ^ (h >> 20)) & hmask;
75 }
76 
77 static inline unsigned int __idx_hash(u32 index, unsigned int hmask)
78 {
79 	return (index ^ (index >> 8)) & hmask;
80 }
81 
82 static inline unsigned int __sel_hash(struct xfrm_selector *sel, unsigned short family, unsigned int hmask)
83 {
84 	xfrm_address_t *daddr = &sel->daddr;
85 	xfrm_address_t *saddr = &sel->saddr;
86 	unsigned int h = 0;
87 
88 	switch (family) {
89 	case AF_INET:
90 		if (sel->prefixlen_d != 32 ||
91 		    sel->prefixlen_s != 32)
92 			return hmask + 1;
93 
94 		h = __xfrm4_daddr_saddr_hash(daddr, saddr);
95 		break;
96 
97 	case AF_INET6:
98 		if (sel->prefixlen_d != 128 ||
99 		    sel->prefixlen_s != 128)
100 			return hmask + 1;
101 
102 		h = __xfrm6_daddr_saddr_hash(daddr, saddr);
103 		break;
104 	};
105 	h ^= (h >> 16);
106 	return h & hmask;
107 }
108 
109 static inline unsigned int __addr_hash(xfrm_address_t *daddr, xfrm_address_t *saddr, unsigned short family, unsigned int hmask)
110 {
111 	unsigned int h = 0;
112 
113 	switch (family) {
114 	case AF_INET:
115 		h = __xfrm4_daddr_saddr_hash(daddr, saddr);
116 		break;
117 
118 	case AF_INET6:
119 		h = __xfrm6_daddr_saddr_hash(daddr, saddr);
120 		break;
121 	};
122 	h ^= (h >> 16);
123 	return h & hmask;
124 }
125 
126 extern struct hlist_head *xfrm_hash_alloc(unsigned int sz);
127 extern void xfrm_hash_free(struct hlist_head *n, unsigned int sz);
128 
129 #endif /* _XFRM_HASH_H */
130