1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _XFRM_HASH_H
3 #define _XFRM_HASH_H
4
5 #include <linux/xfrm.h>
6 #include <linux/socket.h>
7 #include <linux/jhash.h>
8
9 static inline unsigned int __xfrm4_addr_hash(const xfrm_address_t *addr)
10 {
11 return ntohl(addr->a4);
12 }
13
14 static inline unsigned int __xfrm6_addr_hash(const xfrm_address_t *addr)
15 {
16 return jhash2((__force u32 *)addr->a6, 4, 0);
17 }
18
19 static inline unsigned int __xfrm4_daddr_saddr_hash(const xfrm_address_t *daddr,
20 const xfrm_address_t *saddr)
21 {
22 u32 sum = (__force u32)daddr->a4 + (__force u32)saddr->a4;
23 return ntohl((__force __be32)sum);
24 }
25
26 static inline unsigned int __xfrm6_daddr_saddr_hash(const xfrm_address_t *daddr,
27 const xfrm_address_t *saddr)
28 {
29 return __xfrm6_addr_hash(daddr) ^ __xfrm6_addr_hash(saddr);
30 }
31
32 static 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
44 static 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
54 static inline unsigned int __xfrm6_pref_hash(const xfrm_address_t *addr,
55 __u8 prefixlen)
56 {
57 unsigned int pdw;
58 unsigned 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
75 static 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
84 static 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
101 static 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
118 static 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
134 static inline unsigned int
135 __xfrm_seq_hash(u32 seq, unsigned int hmask)
136 {
137 unsigned int h = seq;
138 return (h ^ (h >> 10) ^ (h >> 20)) & hmask;
139 }
140
141 static inline unsigned int __idx_hash(u32 index, unsigned int hmask)
142 {
143 return (index ^ (index >> 8)) & hmask;
144 }
145
146 static inline unsigned int __sel_hash(const struct xfrm_selector *sel,
147 unsigned short family, unsigned int hmask,
148 u8 dbits, u8 sbits)
149 {
150 const xfrm_address_t *daddr = &sel->daddr;
151 const xfrm_address_t *saddr = &sel->saddr;
152 unsigned int h = 0;
153
154 switch (family) {
155 case AF_INET:
156 if (sel->prefixlen_d < dbits ||
157 sel->prefixlen_s < sbits)
158 return hmask + 1;
159
160 h = __xfrm4_dpref_spref_hash(daddr, saddr, dbits, sbits);
161 break;
162
163 case AF_INET6:
164 if (sel->prefixlen_d < dbits ||
165 sel->prefixlen_s < sbits)
166 return hmask + 1;
167
168 h = __xfrm6_dpref_spref_hash(daddr, saddr, dbits, sbits);
169 break;
170 }
171 h ^= (h >> 16);
172 return h & hmask;
173 }
174
175 static inline unsigned int __addr_hash(const xfrm_address_t *daddr,
176 const xfrm_address_t *saddr,
177 unsigned short family,
178 unsigned int hmask,
179 u8 dbits, u8 sbits)
180 {
181 unsigned int h = 0;
182
183 switch (family) {
184 case AF_INET:
185 h = __xfrm4_dpref_spref_hash(daddr, saddr, dbits, sbits);
186 break;
187
188 case AF_INET6:
189 h = __xfrm6_dpref_spref_hash(daddr, saddr, dbits, sbits);
190 break;
191 }
192 h ^= (h >> 16);
193 return h & hmask;
194 }
195
196 struct hlist_head *xfrm_hash_alloc(unsigned int sz);
197 void xfrm_hash_free(struct hlist_head *n, unsigned int sz);
198
199 #endif /* _XFRM_HASH_H */
200
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