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