xref: /linux/net/xfrm/xfrm_hash.h (revision 762f99f4f3cb41a775b5157dd761217beba65873)
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 
__xfrm4_addr_hash(const xfrm_address_t * addr)9 static inline unsigned int __xfrm4_addr_hash(const xfrm_address_t *addr)
10 {
11 	return ntohl(addr->a4);
12 }
13 
__xfrm6_addr_hash(const xfrm_address_t * addr)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 
__xfrm4_daddr_saddr_hash(const xfrm_address_t * daddr,const xfrm_address_t * saddr)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 
__xfrm6_daddr_saddr_hash(const xfrm_address_t * daddr,const xfrm_address_t * saddr)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 
__bits2mask32(__u8 bits)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 
__xfrm4_dpref_spref_hash(const xfrm_address_t * daddr,const xfrm_address_t * saddr,__u8 dbits,__u8 sbits)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 
__xfrm6_pref_hash(const xfrm_address_t * addr,__u8 prefixlen)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 
__xfrm6_dpref_spref_hash(const xfrm_address_t * daddr,const xfrm_address_t * saddr,__u8 dbits,__u8 sbits)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 
__xfrm_dst_hash(const xfrm_address_t * daddr,const xfrm_address_t * saddr,u32 reqid,unsigned short family,unsigned int hmask)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 
__xfrm_src_hash(const xfrm_address_t * daddr,const xfrm_address_t * saddr,unsigned short family,unsigned int hmask)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
__xfrm_spi_hash(const xfrm_address_t * daddr,__be32 spi,u8 proto,unsigned short family,unsigned int hmask)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
__xfrm_seq_hash(u32 seq,unsigned int hmask)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 
__idx_hash(u32 index,unsigned int hmask)141 static inline unsigned int __idx_hash(u32 index, unsigned int hmask)
142 {
143 	return (index ^ (index >> 8)) & hmask;
144 }
145 
__sel_hash(const struct xfrm_selector * sel,unsigned short family,unsigned int hmask,u8 dbits,u8 sbits)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 
__addr_hash(const xfrm_address_t * daddr,const xfrm_address_t * saddr,unsigned short family,unsigned int hmask,u8 dbits,u8 sbits)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