1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 2 * All rights reserved. 3 * 4 * This package is an SSL implementation written 5 * by Eric Young (eay@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@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@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@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_INTERNAL_H 58 #define OPENSSL_HEADER_LHASH_INTERNAL_H 59 60 #include <openssl/lhash.h> 61 62 #if defined(__cplusplus) 63 extern "C" { 64 #endif 65 66 67 // lhash is a traditional, chaining hash table that automatically expands and 68 // contracts as needed. One should not use the lh_* functions directly, rather 69 // use the type-safe macro wrappers: 70 // 71 // A hash table of a specific type of object has type |LHASH_OF(type)|. This 72 // can be defined (once) with |DEFINE_LHASH_OF(type)| and declared where needed 73 // with |DECLARE_LHASH_OF(type)|. For example: 74 // 75 // struct foo { 76 // int bar; 77 // }; 78 // 79 // DEFINE_LHASH_OF(struct foo) 80 // 81 // Although note that the hash table will contain /pointers/ to |foo|. 82 // 83 // A macro will be defined for each of the |OPENSSL_lh_*| functions below. For 84 // |LHASH_OF(foo)|, the macros would be |lh_foo_new|, |lh_foo_num_items| etc. 85 86 87 // lhash_cmp_func is a comparison function that returns a value equal, or not 88 // equal, to zero depending on whether |*a| is equal, or not equal to |*b|, 89 // respectively. Note the difference between this and |stack_cmp_func| in that 90 // this takes pointers to the objects directly. 91 // 92 // This function's actual type signature is int (*)(const T*, const T*). The 93 // low-level |lh_*| functions will be passed a type-specific wrapper to call it 94 // correctly. 95 typedef int (*lhash_cmp_func)(const void *a, const void *b); 96 typedef int (*lhash_cmp_func_helper)(lhash_cmp_func func, const void *a, 97 const void *b); 98 99 // lhash_hash_func is a function that maps an object to a uniformly distributed 100 // uint32_t. 101 // 102 // This function's actual type signature is uint32_t (*)(const T*). The 103 // low-level |lh_*| functions will be passed a type-specific wrapper to call it 104 // correctly. 105 typedef uint32_t (*lhash_hash_func)(const void *a); 106 typedef uint32_t (*lhash_hash_func_helper)(lhash_hash_func func, const void *a); 107 108 typedef struct lhash_st _LHASH; 109 110 // OPENSSL_lh_new returns a new, empty hash table or NULL on error. 111 OPENSSL_EXPORT _LHASH *OPENSSL_lh_new(lhash_hash_func hash, 112 lhash_cmp_func comp); 113 114 // OPENSSL_lh_free frees the hash table itself but none of the elements. See 115 // |OPENSSL_lh_doall|. 116 OPENSSL_EXPORT void OPENSSL_lh_free(_LHASH *lh); 117 118 // OPENSSL_lh_num_items returns the number of items in |lh|. 119 OPENSSL_EXPORT size_t OPENSSL_lh_num_items(const _LHASH *lh); 120 121 // OPENSSL_lh_retrieve finds an element equal to |data| in the hash table and 122 // returns it. If no such element exists, it returns NULL. 123 OPENSSL_EXPORT void *OPENSSL_lh_retrieve(const _LHASH *lh, const void *data, 124 lhash_hash_func_helper call_hash_func, 125 lhash_cmp_func_helper call_cmp_func); 126 127 // OPENSSL_lh_retrieve_key finds an element matching |key|, given the specified 128 // hash and comparison function. This differs from |OPENSSL_lh_retrieve| in that 129 // the key may be a different type than the values stored in |lh|. |key_hash| 130 // and |cmp_key| must be compatible with the functions passed into 131 // |OPENSSL_lh_new|. 132 OPENSSL_EXPORT void *OPENSSL_lh_retrieve_key(const _LHASH *lh, const void *key, 133 uint32_t key_hash, 134 int (*cmp_key)(const void *key, 135 const void *value)); 136 137 // OPENSSL_lh_insert inserts |data| into the hash table. If an existing element 138 // is equal to |data| (with respect to the comparison function) then |*old_data| 139 // will be set to that value and it will be replaced. Otherwise, or in the 140 // event of an error, |*old_data| will be set to NULL. It returns one on 141 // success or zero in the case of an allocation error. 142 OPENSSL_EXPORT int OPENSSL_lh_insert(_LHASH *lh, void **old_data, void *data, 143 lhash_hash_func_helper call_hash_func, 144 lhash_cmp_func_helper call_cmp_func); 145 146 // OPENSSL_lh_delete removes an element equal to |data| from the hash table and 147 // returns it. If no such element is found, it returns NULL. 148 OPENSSL_EXPORT void *OPENSSL_lh_delete(_LHASH *lh, const void *data, 149 lhash_hash_func_helper call_hash_func, 150 lhash_cmp_func_helper call_cmp_func); 151 152 // OPENSSL_lh_doall_arg calls |func| on each element of the hash table and also 153 // passes |arg| as the second argument. 154 // TODO(fork): rename this 155 OPENSSL_EXPORT void OPENSSL_lh_doall_arg(_LHASH *lh, 156 void (*func)(void *, void *), 157 void *arg); 158 159 #define DEFINE_LHASH_OF(type) \ 160 /* We disable MSVC C4191 in this macro, which warns when pointers are cast \ 161 * to the wrong type. While the cast itself is valid, it is often a bug \ 162 * because calling it through the cast is UB. However, we never actually \ 163 * call functions as |lhash_cmp_func|. The type is just a type-erased \ 164 * function pointer. (C does not guarantee function pointers fit in \ 165 * |void*|, and GCC will warn on this.) Thus we just disable the false \ 166 * positive warning. */ \ 167 OPENSSL_MSVC_PRAGMA(warning(push)) \ 168 OPENSSL_MSVC_PRAGMA(warning(disable : 4191)) \ 169 \ 170 DECLARE_LHASH_OF(type) \ 171 \ 172 typedef int (*lhash_##type##_cmp_func)(const type *, const type *); \ 173 typedef uint32_t (*lhash_##type##_hash_func)(const type *); \ 174 \ 175 OPENSSL_INLINE int lh_##type##_call_cmp_func(lhash_cmp_func func, \ 176 const void *a, const void *b) { \ 177 return ((lhash_##type##_cmp_func)func)((const type *)a, (const type *)b); \ 178 } \ 179 \ 180 OPENSSL_INLINE uint32_t lh_##type##_call_hash_func(lhash_hash_func func, \ 181 const void *a) { \ 182 return ((lhash_##type##_hash_func)func)((const type *)a); \ 183 } \ 184 \ 185 OPENSSL_INLINE LHASH_OF(type) *lh_##type##_new( \ 186 lhash_##type##_hash_func hash, lhash_##type##_cmp_func comp) { \ 187 return (LHASH_OF(type) *)OPENSSL_lh_new((lhash_hash_func)hash, \ 188 (lhash_cmp_func)comp); \ 189 } \ 190 \ 191 OPENSSL_INLINE void lh_##type##_free(LHASH_OF(type) *lh) { \ 192 OPENSSL_lh_free((_LHASH *)lh); \ 193 } \ 194 \ 195 OPENSSL_INLINE size_t lh_##type##_num_items(const LHASH_OF(type) *lh) { \ 196 return OPENSSL_lh_num_items((const _LHASH *)lh); \ 197 } \ 198 \ 199 OPENSSL_INLINE type *lh_##type##_retrieve(const LHASH_OF(type) *lh, \ 200 const type *data) { \ 201 return (type *)OPENSSL_lh_retrieve((const _LHASH *)lh, data, \ 202 lh_##type##_call_hash_func, \ 203 lh_##type##_call_cmp_func); \ 204 } \ 205 \ 206 typedef struct { \ 207 int (*cmp_key)(const void *key, const type *value); \ 208 const void *key; \ 209 } LHASH_CMP_KEY_##type; \ 210 \ 211 OPENSSL_INLINE int lh_##type##_call_cmp_key(const void *key, \ 212 const void *value) { \ 213 const LHASH_CMP_KEY_##type *cb = (const LHASH_CMP_KEY_##type *)key; \ 214 return cb->cmp_key(cb->key, (const type *)value); \ 215 } \ 216 \ 217 OPENSSL_INLINE type *lh_##type##_retrieve_key( \ 218 const LHASH_OF(type) *lh, const void *key, uint32_t key_hash, \ 219 int (*cmp_key)(const void *key, const type *value)) { \ 220 LHASH_CMP_KEY_##type cb = {cmp_key, key}; \ 221 return (type *)OPENSSL_lh_retrieve_key((const _LHASH *)lh, &cb, key_hash, \ 222 lh_##type##_call_cmp_key); \ 223 } \ 224 \ 225 OPENSSL_INLINE int lh_##type##_insert(LHASH_OF(type) *lh, type **old_data, \ 226 type *data) { \ 227 void *old_data_void = NULL; \ 228 int ret = OPENSSL_lh_insert((_LHASH *)lh, &old_data_void, data, \ 229 lh_##type##_call_hash_func, \ 230 lh_##type##_call_cmp_func); \ 231 *old_data = (type *)old_data_void; \ 232 return ret; \ 233 } \ 234 \ 235 OPENSSL_INLINE type *lh_##type##_delete(LHASH_OF(type) *lh, \ 236 const type *data) { \ 237 return (type *)OPENSSL_lh_delete((_LHASH *)lh, data, \ 238 lh_##type##_call_hash_func, \ 239 lh_##type##_call_cmp_func); \ 240 } \ 241 \ 242 typedef struct { \ 243 void (*doall_arg)(type *, void *); \ 244 void *arg; \ 245 } LHASH_DOALL_##type; \ 246 \ 247 OPENSSL_INLINE void lh_##type##_call_doall_arg(void *value, void *arg) { \ 248 const LHASH_DOALL_##type *cb = (const LHASH_DOALL_##type *)arg; \ 249 cb->doall_arg((type *)value, cb->arg); \ 250 } \ 251 \ 252 OPENSSL_INLINE void lh_##type##_doall_arg( \ 253 LHASH_OF(type) *lh, void (*func)(type *, void *), void *arg) { \ 254 LHASH_DOALL_##type cb = {func, arg}; \ 255 OPENSSL_lh_doall_arg((_LHASH *)lh, lh_##type##_call_doall_arg, &cb); \ 256 } \ 257 \ 258 OPENSSL_MSVC_PRAGMA(warning(pop)) 259 260 261 #if defined(__cplusplus) 262 } // extern C 263 #endif 264 265 #endif // OPENSSL_HEADER_LHASH_INTERNAL_H 266