1#ifndef _XFRM_HASH_H
2#define _XFRM_HASH_H
3
4#include <linux/xfrm.h>
5#include <linux/socket.h>
6#include <linux/jhash.h>
7
8static inline unsigned int __xfrm4_addr_hash(const xfrm_address_t *addr)
9{
10	return ntohl(addr->a4);
11}
12
13static inline unsigned int __xfrm6_addr_hash(const xfrm_address_t *addr)
14{
15	return ntohl(addr->a6[2] ^ addr->a6[3]);
16}
17
18static inline unsigned int __xfrm4_daddr_saddr_hash(const xfrm_address_t *daddr,
19						    const xfrm_address_t *saddr)
20{
21	u32 sum = (__force u32)daddr->a4 + (__force u32)saddr->a4;
22	return ntohl((__force __be32)sum);
23}
24
25static inline unsigned int __xfrm6_daddr_saddr_hash(const xfrm_address_t *daddr,
26						    const xfrm_address_t *saddr)
27{
28	return ntohl(daddr->a6[2] ^ daddr->a6[3] ^
29		     saddr->a6[2] ^ saddr->a6[3]);
30}
31
32static inline u32 __bits2mask32(__u8 bits)
33{
34	u32 mask32 = 0xffffffff;
35
36	if (bits == 0)
37		mask32 = 0;
38	else if (bits < 32)
39		mask32 <<= (32 - bits);
40
41	return mask32;
42}
43
44static inline unsigned int __xfrm4_dpref_spref_hash(const xfrm_address_t *daddr,
45						    const xfrm_address_t *saddr,
46						    __u8 dbits,
47						    __u8 sbits)
48{
49	return jhash_2words(ntohl(daddr->a4) & __bits2mask32(dbits),
50			    ntohl(saddr->a4) & __bits2mask32(sbits),
51			    0);
52}
53
54static inline unsigned int __xfrm6_pref_hash(const xfrm_address_t *addr,
55					     __u8 prefixlen)
56{
57	int pdw;
58	int pbi;
59	u32 initval = 0;
60
61	pdw = prefixlen >> 5;     /* num of whole u32 in prefix */
62	pbi = prefixlen &  0x1f;  /* num of bits in incomplete u32 in prefix */
63
64	if (pbi) {
65		__be32 mask;
66
67		mask = htonl((0xffffffff) << (32 - pbi));
68
69		initval = (__force u32)(addr->a6[pdw] & mask);
70	}
71
72	return jhash2((__force u32 *)addr->a6, pdw, initval);
73}
74
75static inline unsigned int __xfrm6_dpref_spref_hash(const xfrm_address_t *daddr,
76						    const xfrm_address_t *saddr,
77						    __u8 dbits,
78						    __u8 sbits)
79{
80	return __xfrm6_pref_hash(daddr, dbits) ^
81	       __xfrm6_pref_hash(saddr, sbits);
82}
83
84static inline unsigned int __xfrm_dst_hash(const xfrm_address_t *daddr,
85					   const xfrm_address_t *saddr,
86					   u32 reqid, unsigned short family,
87					   unsigned int hmask)
88{
89	unsigned int h = family ^ reqid;
90	switch (family) {
91	case AF_INET:
92		h ^= __xfrm4_daddr_saddr_hash(daddr, saddr);
93		break;
94	case AF_INET6:
95		h ^= __xfrm6_daddr_saddr_hash(daddr, saddr);
96		break;
97	}
98	return (h ^ (h >> 16)) & hmask;
99}
100
101static inline unsigned int __xfrm_src_hash(const xfrm_address_t *daddr,
102					   const xfrm_address_t *saddr,
103					   unsigned short family,
104					   unsigned int hmask)
105{
106	unsigned int h = family;
107	switch (family) {
108	case AF_INET:
109		h ^= __xfrm4_daddr_saddr_hash(daddr, saddr);
110		break;
111	case AF_INET6:
112		h ^= __xfrm6_daddr_saddr_hash(daddr, saddr);
113		break;
114	}
115	return (h ^ (h >> 16)) & hmask;
116}
117
118static inline unsigned int
119__xfrm_spi_hash(const xfrm_address_t *daddr, __be32 spi, u8 proto,
120		unsigned short family, unsigned int hmask)
121{
122	unsigned int h = (__force u32)spi ^ proto;
123	switch (family) {
124	case AF_INET:
125		h ^= __xfrm4_addr_hash(daddr);
126		break;
127	case AF_INET6:
128		h ^= __xfrm6_addr_hash(daddr);
129		break;
130	}
131	return (h ^ (h >> 10) ^ (h >> 20)) & hmask;
132}
133
134static inline unsigned int __idx_hash(u32 index, unsigned int hmask)
135{
136	return (index ^ (index >> 8)) & hmask;
137}
138
139static inline unsigned int __sel_hash(const struct xfrm_selector *sel,
140				      unsigned short family, unsigned int hmask,
141				      u8 dbits, u8 sbits)
142{
143	const xfrm_address_t *daddr = &sel->daddr;
144	const xfrm_address_t *saddr = &sel->saddr;
145	unsigned int h = 0;
146
147	switch (family) {
148	case AF_INET:
149		if (sel->prefixlen_d < dbits ||
150		    sel->prefixlen_s < sbits)
151			return hmask + 1;
152
153		h = __xfrm4_dpref_spref_hash(daddr, saddr, dbits, sbits);
154		break;
155
156	case AF_INET6:
157		if (sel->prefixlen_d < dbits ||
158		    sel->prefixlen_s < sbits)
159			return hmask + 1;
160
161		h = __xfrm6_dpref_spref_hash(daddr, saddr, dbits, sbits);
162		break;
163	}
164	h ^= (h >> 16);
165	return h & hmask;
166}
167
168static inline unsigned int __addr_hash(const xfrm_address_t *daddr,
169				       const xfrm_address_t *saddr,
170				       unsigned short family,
171				       unsigned int hmask,
172				       u8 dbits, u8 sbits)
173{
174	unsigned int h = 0;
175
176	switch (family) {
177	case AF_INET:
178		h = __xfrm4_dpref_spref_hash(daddr, saddr, dbits, sbits);
179		break;
180
181	case AF_INET6:
182		h = __xfrm6_dpref_spref_hash(daddr, saddr, dbits, sbits);
183		break;
184	}
185	h ^= (h >> 16);
186	return h & hmask;
187}
188
189struct hlist_head *xfrm_hash_alloc(unsigned int sz);
190void xfrm_hash_free(struct hlist_head *n, unsigned int sz);
191
192#endif /* _XFRM_HASH_H */
193