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(k: (__force u32 *)addr->a6, length: 4, initval: 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(addr: daddr) ^ __xfrm6_addr_hash(addr: 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(bits: dbits), |
50 | ntohl(saddr->a4) & __bits2mask32(bits: sbits), |
51 | initval: 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(k: (__force u32 *)addr->a6, length: 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(addr: daddr, prefixlen: dbits) ^ |
81 | __xfrm6_pref_hash(addr: saddr, prefixlen: 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(addr: daddr); |
126 | break; |
127 | case AF_INET6: |
128 | h ^= __xfrm6_addr_hash(addr: 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 | |