1 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com) 2 * All rights reserved. 3 * 4 * This package is an SSL implementation written 5 * by Eric Young (eay (at) cryptsoft.com). 6 * The implementation was written so as to conform with Netscapes SSL. 7 * 8 * This library is free for commercial and non-commercial use as long as 9 * the following conditions are aheared to. The following conditions 10 * apply to all code found in this distribution, be it the RC4, RSA, 11 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 12 * included with this distribution is covered by the same copyright terms 13 * except that the holder is Tim Hudson (tjh (at) cryptsoft.com). 14 * 15 * Copyright remains Eric Young's, and as such any Copyright notices in 16 * the code are not to be removed. 17 * If this package is used in a product, Eric Young should be given attribution 18 * as the author of the parts of the library used. 19 * This can be in the form of a textual message at program startup or 20 * in documentation (online or textual) provided with the package. 21 * 22 * Redistribution and use in source and binary forms, with or without 23 * modification, are permitted provided that the following conditions 24 * are met: 25 * 1. Redistributions of source code must retain the copyright 26 * notice, this list of conditions and the following disclaimer. 27 * 2. Redistributions in binary form must reproduce the above copyright 28 * notice, this list of conditions and the following disclaimer in the 29 * documentation and/or other materials provided with the distribution. 30 * 3. All advertising materials mentioning features or use of this software 31 * must display the following acknowledgement: 32 * "This product includes cryptographic software written by 33 * Eric Young (eay (at) cryptsoft.com)" 34 * The word 'cryptographic' can be left out if the rouines from the library 35 * being used are not cryptographic related :-). 36 * 4. If you include any Windows specific code (or a derivative thereof) from 37 * the apps directory (application code) you must include an acknowledgement: 38 * "This product includes software written by Tim Hudson (tjh (at) cryptsoft.com)" 39 * 40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 43 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 50 * SUCH DAMAGE. 51 * 52 * The licence and distribution terms for any publically available version or 53 * derivative of this code cannot be changed. i.e. this code cannot simply be 54 * copied and put under another distribution licence 55 * [including the GNU Public Licence.] */ 56 57 #ifndef OPENSSL_HEADER_LHASH_H 58 #define OPENSSL_HEADER_LHASH_H 59 60 #include <openssl/base.h> 61 #include <openssl/type_check.h> 62 63 #if defined(__cplusplus) 64 extern "C" { 65 #endif 66 67 68 // lhash is a traditional, chaining hash table that automatically expands and 69 // contracts as needed. One should not use the lh_* functions directly, rather 70 // use the type-safe macro wrappers: 71 // 72 // A hash table of a specific type of object has type |LHASH_OF(type)|. This 73 // can be defined (once) with |DEFINE_LHASH_OF(type)| and declared where needed 74 // with |DECLARE_LHASH_OF(type)|. For example: 75 // 76 // struct foo { 77 // int bar; 78 // }; 79 // 80 // DEFINE_LHASH_OF(struct foo) 81 // 82 // Although note that the hash table will contain /pointers/ to |foo|. 83 // 84 // A macro will be defined for each of the lh_* functions below. For 85 // LHASH_OF(foo), the macros would be lh_foo_new, lh_foo_num_items etc. 86 87 88 #define LHASH_OF(type) struct lhash_st_##type 89 90 #define DECLARE_LHASH_OF(type) LHASH_OF(type); 91 92 93 // lhash_item_st is an element of a hash chain. It points to the opaque data 94 // for this element and to the next item in the chain. The linked-list is NULL 95 // terminated. 96 typedef struct lhash_item_st { 97 void *data; 98 struct lhash_item_st *next; 99 // hash contains the cached, hash value of |data|. 100 uint32_t hash; 101 } LHASH_ITEM; 102 103 // lhash_cmp_func is a comparison function that returns a value equal, or not 104 // equal, to zero depending on whether |*a| is equal, or not equal to |*b|, 105 // respectively. Note the difference between this and |stack_cmp_func| in that 106 // this takes pointers to the objects directly. 107 // 108 // This function's actual type signature is int (*)(const T*, const T*). The 109 // low-level |lh_*| functions will be passed a type-specific wrapper to call it 110 // correctly. 111 typedef int (*lhash_cmp_func)(const void *a, const void *b); 112 typedef int (*lhash_cmp_func_helper)(lhash_cmp_func func, const void *a, 113 const void *b); 114 115 // lhash_hash_func is a function that maps an object to a uniformly distributed 116 // uint32_t. 117 // 118 // This function's actual type signature is uint32_t (*)(const T*). The 119 // low-level |lh_*| functions will be passed a type-specific wrapper to call it 120 // correctly. 121 typedef uint32_t (*lhash_hash_func)(const void *a); 122 typedef uint32_t (*lhash_hash_func_helper)(lhash_hash_func func, const void *a); 123 124 typedef struct lhash_st _LHASH; 125 126 // lh_new returns a new, empty hash table or NULL on error. 127 OPENSSL_EXPORT _LHASH *lh_new(lhash_hash_func hash, lhash_cmp_func comp); 128 129 // lh_free frees the hash table itself but none of the elements. See 130 // |lh_doall|. 131 OPENSSL_EXPORT void lh_free(_LHASH *lh); 132 133 // lh_num_items returns the number of items in |lh|. 134 OPENSSL_EXPORT size_t lh_num_items(const _LHASH *lh); 135 136 // lh_retrieve finds an element equal to |data| in the hash table and returns 137 // it. If no such element exists, it returns NULL. 138 OPENSSL_EXPORT void *lh_retrieve(const _LHASH *lh, const void *data, 139 lhash_hash_func_helper call_hash_func, 140 lhash_cmp_func_helper call_cmp_func); 141 142 // lh_retrieve_key finds an element matching |key|, given the specified hash and 143 // comparison function. This differs from |lh_retrieve| in that the key may be a 144 // different type than the values stored in |lh|. |key_hash| and |cmp_key| must 145 // be compatible with the functions passed into |lh_new|. 146 OPENSSL_EXPORT void *lh_retrieve_key(const _LHASH *lh, const void *key, 147 uint32_t key_hash, 148 int (*cmp_key)(const void *key, 149 const void *value)); 150 151 // lh_insert inserts |data| into the hash table. If an existing element is 152 // equal to |data| (with respect to the comparison function) then |*old_data| 153 // will be set to that value and it will be replaced. Otherwise, or in the 154 // event of an error, |*old_data| will be set to NULL. It returns one on 155 // success or zero in the case of an allocation error. 156 OPENSSL_EXPORT int lh_insert(_LHASH *lh, void **old_data, void *data, 157 lhash_hash_func_helper call_hash_func, 158 lhash_cmp_func_helper call_cmp_func); 159 160 // lh_delete removes an element equal to |data| from the hash table and returns 161 // it. If no such element is found, it returns NULL. 162 OPENSSL_EXPORT void *lh_delete(_LHASH *lh, const void *data, 163 lhash_hash_func_helper call_hash_func, 164 lhash_cmp_func_helper call_cmp_func); 165 166 // lh_doall_arg calls |func| on each element of the hash table and also passes 167 // |arg| as the second argument. 168 // TODO(fork): rename this 169 OPENSSL_EXPORT void lh_doall_arg(_LHASH *lh, void (*func)(void *, void *), 170 void *arg); 171 172 // lh_strhash is the default hash function which processes NUL-terminated 173 // strings. 174 OPENSSL_EXPORT uint32_t lh_strhash(const char *c); 175 176 #define DEFINE_LHASH_OF(type) \ 177 DECLARE_LHASH_OF(type) \ 178 \ 179 typedef int (*lhash_##type##_cmp_func)(const type *, const type *); \ 180 typedef uint32_t (*lhash_##type##_hash_func)(const type *); \ 181 \ 182 OPENSSL_INLINE int lh_##type##_call_cmp_func(lhash_cmp_func func, \ 183 const void *a, const void *b) { \ 184 return ((lhash_##type##_cmp_func)func)((const type *)a, (const type *)b); \ 185 } \ 186 \ 187 OPENSSL_INLINE uint32_t lh_##type##_call_hash_func(lhash_hash_func func, \ 188 const void *a) { \ 189 return ((lhash_##type##_hash_func)func)((const type *)a); \ 190 } \ 191 \ 192 OPENSSL_INLINE LHASH_OF(type) * \ 193 lh_##type##_new(lhash_##type##_hash_func hash, \ 194 lhash_##type##_cmp_func comp) { \ 195 return (LHASH_OF(type) *)lh_new((lhash_hash_func)hash, \ 196 (lhash_cmp_func)comp); \ 197 } \ 198 \ 199 OPENSSL_INLINE void lh_##type##_free(LHASH_OF(type) *lh) { \ 200 lh_free((_LHASH *)lh); \ 201 } \ 202 \ 203 OPENSSL_INLINE size_t lh_##type##_num_items(const LHASH_OF(type) *lh) { \ 204 return lh_num_items((const _LHASH *)lh); \ 205 } \ 206 \ 207 OPENSSL_INLINE type *lh_##type##_retrieve(const LHASH_OF(type) *lh, \ 208 const type *data) { \ 209 return (type *)lh_retrieve((const _LHASH *)lh, data, \ 210 lh_##type##_call_hash_func, \ 211 lh_##type##_call_cmp_func); \ 212 } \ 213 \ 214 typedef struct { \ 215 int (*cmp_key)(const void *key, const type *value); \ 216 const void *key; \ 217 } LHASH_CMP_KEY_##type; \ 218 \ 219 OPENSSL_INLINE int lh_##type##_call_cmp_key(const void *key, \ 220 const void *value) { \ 221 const LHASH_CMP_KEY_##type *cb = (const LHASH_CMP_KEY_##type *)key; \ 222 return cb->cmp_key(cb->key, (const type *)value); \ 223 } \ 224 \ 225 OPENSSL_INLINE type *lh_##type##_retrieve_key( \ 226 const LHASH_OF(type) *lh, const void *key, uint32_t key_hash, \ 227 int (*cmp_key)(const void *key, const type *value)) { \ 228 LHASH_CMP_KEY_##type cb = {cmp_key, key}; \ 229 return (type *)lh_retrieve_key((const _LHASH *)lh, &cb, key_hash, \ 230 lh_##type##_call_cmp_key); \ 231 } \ 232 \ 233 OPENSSL_INLINE int lh_##type##_insert(LHASH_OF(type) *lh, type **old_data, \ 234 type *data) { \ 235 void *old_data_void = NULL; \ 236 int ret = \ 237 lh_insert((_LHASH *)lh, &old_data_void, data, \ 238 lh_##type##_call_hash_func, lh_##type##_call_cmp_func); \ 239 *old_data = (type *)old_data_void; \ 240 return ret; \ 241 } \ 242 \ 243 OPENSSL_INLINE type *lh_##type##_delete(LHASH_OF(type) *lh, \ 244 const type *data) { \ 245 return (type *)lh_delete((_LHASH *)lh, data, lh_##type##_call_hash_func, \ 246 lh_##type##_call_cmp_func); \ 247 } \ 248 \ 249 typedef struct { \ 250 void (*doall)(type *); \ 251 void (*doall_arg)(type *, void *); \ 252 void *arg; \ 253 } LHASH_DOALL_##type; \ 254 \ 255 OPENSSL_INLINE void lh_##type##_call_doall(void *value, void *arg) { \ 256 const LHASH_DOALL_##type *cb = (const LHASH_DOALL_##type *)arg; \ 257 cb->doall((type *)value); \ 258 } \ 259 \ 260 OPENSSL_INLINE void lh_##type##_call_doall_arg(void *value, void *arg) { \ 261 const LHASH_DOALL_##type *cb = (const LHASH_DOALL_##type *)arg; \ 262 cb->doall_arg((type *)value, cb->arg); \ 263 } \ 264 \ 265 OPENSSL_INLINE void lh_##type##_doall(LHASH_OF(type) *lh, \ 266 void (*func)(type *)) { \ 267 LHASH_DOALL_##type cb = {func, NULL, NULL}; \ 268 lh_doall_arg((_LHASH *)lh, lh_##type##_call_doall, &cb); \ 269 } \ 270 \ 271 OPENSSL_INLINE void lh_##type##_doall_arg( \ 272 LHASH_OF(type) *lh, void (*func)(type *, void *), void *arg) { \ 273 LHASH_DOALL_##type cb = {NULL, func, arg}; \ 274 lh_doall_arg((_LHASH *)lh, lh_##type##_call_doall_arg, &cb); \ 275 } 276 277 278 #if defined(__cplusplus) 279 } // extern C 280 #endif 281 282 #endif // OPENSSL_HEADER_LHASH_H 283
