1 /* $OpenBSD: lhash.c,v 1.19 2019/05/12 00:09:59 beck Exp $ */ 2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 3 * All rights reserved. 4 * 5 * This package is an SSL implementation written 6 * by Eric Young (eay@cryptsoft.com). 7 * The implementation was written so as to conform with Netscapes SSL. 8 * 9 * This library is free for commercial and non-commercial use as long as 10 * the following conditions are aheared to. The following conditions 11 * apply to all code found in this distribution, be it the RC4, RSA, 12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 13 * included with this distribution is covered by the same copyright terms 14 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 15 * 16 * Copyright remains Eric Young's, and as such any Copyright notices in 17 * the code are not to be removed. 18 * If this package is used in a product, Eric Young should be given attribution 19 * as the author of the parts of the library used. 20 * This can be in the form of a textual message at program startup or 21 * in documentation (online or textual) provided with the package. 22 * 23 * Redistribution and use in source and binary forms, with or without 24 * modification, are permitted provided that the following conditions 25 * are met: 26 * 1. Redistributions of source code must retain the copyright 27 * notice, this list of conditions and the following disclaimer. 28 * 2. Redistributions in binary form must reproduce the above copyright 29 * notice, this list of conditions and the following disclaimer in the 30 * documentation and/or other materials provided with the distribution. 31 * 3. All advertising materials mentioning features or use of this software 32 * must display the following acknowledgement: 33 * "This product includes cryptographic software written by 34 * Eric Young (eay@cryptsoft.com)" 35 * The word 'cryptographic' can be left out if the rouines from the library 36 * being used are not cryptographic related :-). 37 * 4. If you include any Windows specific code (or a derivative thereof) from 38 * the apps directory (application code) you must include an acknowledgement: 39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 40 * 41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 51 * SUCH DAMAGE. 52 * 53 * The licence and distribution terms for any publically available version or 54 * derivative of this code cannot be changed. i.e. this code cannot simply be 55 * copied and put under another distribution licence 56 * [including the GNU Public Licence.] 57 */ 58 59 /* Code for dynamic hash table routines 60 * Author - Eric Young v 2.0 61 * 62 * 2.2 eay - added #include "crypto.h" so the memory leak checking code is 63 * present. eay 18-Jun-98 64 * 65 * 2.1 eay - Added an 'error in last operation' flag. eay 6-May-98 66 * 67 * 2.0 eay - Fixed a bug that occurred when using lh_delete 68 * from inside lh_doall(). As entries were deleted, 69 * the 'table' was 'contract()ed', making some entries 70 * jump from the end of the table to the start, there by 71 * skipping the lh_doall() processing. eay - 4/12/95 72 * 73 * 1.9 eay - Fixed a memory leak in lh_free, the LHASH_NODEs 74 * were not being free()ed. 21/11/95 75 * 76 * 1.8 eay - Put the stats routines into a separate file, lh_stats.c 77 * 19/09/95 78 * 79 * 1.7 eay - Removed the fputs() for realloc failures - the code 80 * should silently tolerate them. I have also fixed things 81 * lint complained about 04/05/95 82 * 83 * 1.6 eay - Fixed an invalid pointers in contract/expand 27/07/92 84 * 85 * 1.5 eay - Fixed a misuse of realloc in expand 02/03/1992 86 * 87 * 1.4 eay - Fixed lh_doall so the function can call lh_delete 28/05/91 88 * 89 * 1.3 eay - Fixed a few lint problems 19/3/1991 90 * 91 * 1.2 eay - Fixed lh_doall problem 13/3/1991 92 * 93 * 1.1 eay - Added lh_doall 94 * 95 * 1.0 eay - First version 96 */ 97 #include <stdio.h> 98 #include <string.h> 99 #include <stdlib.h> 100 101 #include <openssl/opensslconf.h> 102 103 #include <openssl/crypto.h> 104 #include <openssl/lhash.h> 105 106 #undef MIN_NODES 107 #define MIN_NODES 16 108 #define UP_LOAD (2*LH_LOAD_MULT) /* load times 256 (default 2) */ 109 #define DOWN_LOAD (LH_LOAD_MULT) /* load times 256 (default 1) */ 110 111 static void expand(_LHASH *lh); 112 static void contract(_LHASH *lh); 113 static LHASH_NODE **getrn(_LHASH *lh, const void *data, unsigned long *rhash); 114 115 _LHASH * 116 lh_new(LHASH_HASH_FN_TYPE h, LHASH_COMP_FN_TYPE c) 117 { 118 _LHASH *ret; 119 120 if ((ret = calloc(1, sizeof(_LHASH))) == NULL) 121 return NULL; 122 if ((ret->b = calloc(MIN_NODES, sizeof(LHASH_NODE *))) == NULL) { 123 free(ret); 124 return NULL; 125 } 126 ret->comp = ((c == NULL) ? (LHASH_COMP_FN_TYPE)strcmp : c); 127 ret->hash = ((h == NULL) ? (LHASH_HASH_FN_TYPE)lh_strhash : h); 128 ret->num_nodes = MIN_NODES / 2; 129 ret->num_alloc_nodes = MIN_NODES; 130 ret->pmax = MIN_NODES / 2; 131 ret->up_load = UP_LOAD; 132 ret->down_load = DOWN_LOAD; 133 134 return (ret); 135 } 136 137 void 138 lh_free(_LHASH *lh) 139 { 140 unsigned int i; 141 LHASH_NODE *n, *nn; 142 143 if (lh == NULL) 144 return; 145 146 for (i = 0; i < lh->num_nodes; i++) { 147 n = lh->b[i]; 148 while (n != NULL) { 149 nn = n->next; 150 free(n); 151 n = nn; 152 } 153 } 154 free(lh->b); 155 free(lh); 156 } 157 158 void * 159 lh_insert(_LHASH *lh, void *data) 160 { 161 unsigned long hash; 162 LHASH_NODE *nn, **rn; 163 void *ret; 164 165 lh->error = 0; 166 if (lh->up_load <= (lh->num_items * LH_LOAD_MULT / lh->num_nodes)) 167 expand(lh); 168 169 rn = getrn(lh, data, &hash); 170 171 if (*rn == NULL) { 172 if ((nn = malloc(sizeof(LHASH_NODE))) == NULL) { 173 lh->error++; 174 return (NULL); 175 } 176 nn->data = data; 177 nn->next = NULL; 178 #ifndef OPENSSL_NO_HASH_COMP 179 nn->hash = hash; 180 #endif 181 *rn = nn; 182 ret = NULL; 183 lh->num_insert++; 184 lh->num_items++; 185 } 186 else /* replace same key */ 187 { 188 ret = (*rn)->data; 189 (*rn)->data = data; 190 lh->num_replace++; 191 } 192 return (ret); 193 } 194 195 void * 196 lh_delete(_LHASH *lh, const void *data) 197 { 198 unsigned long hash; 199 LHASH_NODE *nn, **rn; 200 void *ret; 201 202 lh->error = 0; 203 rn = getrn(lh, data, &hash); 204 205 if (*rn == NULL) { 206 lh->num_no_delete++; 207 return (NULL); 208 } else { 209 nn= *rn; 210 *rn = nn->next; 211 ret = nn->data; 212 free(nn); 213 lh->num_delete++; 214 } 215 216 lh->num_items--; 217 if ((lh->num_nodes > MIN_NODES) && 218 (lh->down_load >= (lh->num_items * LH_LOAD_MULT / lh->num_nodes))) 219 contract(lh); 220 221 return (ret); 222 } 223 224 void * 225 lh_retrieve(_LHASH *lh, const void *data) 226 { 227 unsigned long hash; 228 LHASH_NODE **rn; 229 void *ret; 230 231 lh->error = 0; 232 rn = getrn(lh, data, &hash); 233 234 if (*rn == NULL) { 235 lh->num_retrieve_miss++; 236 return (NULL); 237 } else { 238 ret = (*rn)->data; 239 lh->num_retrieve++; 240 } 241 return (ret); 242 } 243 244 static void 245 doall_util_fn(_LHASH *lh, int use_arg, LHASH_DOALL_FN_TYPE func, 246 LHASH_DOALL_ARG_FN_TYPE func_arg, void *arg) 247 { 248 int i; 249 LHASH_NODE *a, *n; 250 251 if (lh == NULL) 252 return; 253 254 /* reverse the order so we search from 'top to bottom' 255 * We were having memory leaks otherwise */ 256 for (i = lh->num_nodes - 1; i >= 0; i--) { 257 a = lh->b[i]; 258 while (a != NULL) { 259 /* 28/05/91 - eay - n added so items can be deleted 260 * via lh_doall */ 261 /* 22/05/08 - ben - eh? since a is not passed, 262 * this should not be needed */ 263 n = a->next; 264 if (use_arg) 265 func_arg(a->data, arg); 266 else 267 func(a->data); 268 a = n; 269 } 270 } 271 } 272 273 void 274 lh_doall(_LHASH *lh, LHASH_DOALL_FN_TYPE func) 275 { 276 doall_util_fn(lh, 0, func, (LHASH_DOALL_ARG_FN_TYPE)0, NULL); 277 } 278 279 void 280 lh_doall_arg(_LHASH *lh, LHASH_DOALL_ARG_FN_TYPE func, void *arg) 281 { 282 doall_util_fn(lh, 1, (LHASH_DOALL_FN_TYPE)0, func, arg); 283 } 284 285 static void 286 expand(_LHASH *lh) 287 { 288 LHASH_NODE **n, **n1, **n2, *np; 289 unsigned int p, i, j; 290 unsigned long hash, nni; 291 292 lh->num_nodes++; 293 lh->num_expands++; 294 p = (int)lh->p++; 295 n1 = &(lh->b[p]); 296 n2 = &(lh->b[p + (int)lh->pmax]); 297 *n2 = NULL; /* 27/07/92 - eay - undefined pointer bug */ 298 nni = lh->num_alloc_nodes; 299 300 for (np = *n1; np != NULL; ) { 301 #ifndef OPENSSL_NO_HASH_COMP 302 hash = np->hash; 303 #else 304 hash = lh->hash(np->data); 305 lh->num_hash_calls++; 306 #endif 307 if ((hash % nni) != p) { /* move it */ 308 *n1 = (*n1)->next; 309 np->next= *n2; 310 *n2 = np; 311 } else 312 n1 = &((*n1)->next); 313 np= *n1; 314 } 315 316 if ((lh->p) >= lh->pmax) { 317 j = (int)lh->num_alloc_nodes * 2; 318 n = reallocarray(lh->b, j, sizeof(LHASH_NODE *)); 319 if (n == NULL) { 320 /* fputs("realloc error in lhash", stderr); */ 321 lh->error++; 322 lh->p = 0; 323 return; 324 } 325 /* else */ 326 for (i = (int)lh->num_alloc_nodes; i < j; i++)/* 26/02/92 eay */ 327 n[i] = NULL; /* 02/03/92 eay */ 328 lh->pmax = lh->num_alloc_nodes; 329 lh->num_alloc_nodes = j; 330 lh->num_expand_reallocs++; 331 lh->p = 0; 332 lh->b = n; 333 } 334 } 335 336 static void 337 contract(_LHASH *lh) 338 { 339 LHASH_NODE **n, *n1, *np; 340 341 np = lh->b[lh->p + lh->pmax - 1]; 342 lh->b[lh->p+lh->pmax - 1] = NULL; /* 24/07-92 - eay - weird but :-( */ 343 if (lh->p == 0) { 344 n = reallocarray(lh->b, lh->pmax, sizeof(LHASH_NODE *)); 345 if (n == NULL) { 346 /* fputs("realloc error in lhash", stderr); */ 347 lh->error++; 348 return; 349 } 350 lh->num_contract_reallocs++; 351 lh->num_alloc_nodes /= 2; 352 lh->pmax /= 2; 353 lh->p = lh->pmax - 1; 354 lh->b = n; 355 } else 356 lh->p--; 357 358 lh->num_nodes--; 359 lh->num_contracts++; 360 361 n1 = lh->b[(int)lh->p]; 362 if (n1 == NULL) 363 lh->b[(int)lh->p] = np; 364 else { 365 while (n1->next != NULL) 366 n1 = n1->next; 367 n1->next = np; 368 } 369 } 370 371 static LHASH_NODE **getrn(_LHASH *lh, const void *data, unsigned long *rhash) 372 { 373 LHASH_NODE **ret, *n1; 374 unsigned long hash, nn; 375 LHASH_COMP_FN_TYPE cf; 376 377 hash = (*(lh->hash))(data); 378 lh->num_hash_calls++; 379 *rhash = hash; 380 381 nn = hash % lh->pmax; 382 if (nn < lh->p) 383 nn = hash % lh->num_alloc_nodes; 384 385 cf = lh->comp; 386 ret = &(lh->b[(int)nn]); 387 for (n1 = *ret; n1 != NULL; n1 = n1->next) { 388 #ifndef OPENSSL_NO_HASH_COMP 389 lh->num_hash_comps++; 390 if (n1->hash != hash) { 391 ret = &(n1->next); 392 continue; 393 } 394 #endif 395 lh->num_comp_calls++; 396 if (cf(n1->data, data) == 0) 397 break; 398 ret = &(n1->next); 399 } 400 return (ret); 401 } 402 403 /* The following hash seems to work very well on normal text strings 404 * no collisions on /usr/dict/words and it distributes on %2^n quite 405 * well, not as good as MD5, but still good. 406 */ 407 unsigned long 408 lh_strhash(const char *c) 409 { 410 unsigned long ret = 0; 411 unsigned long n, v; 412 unsigned int r; 413 414 if (c == NULL || *c == '\0') 415 return ret; 416 417 n = 0x100; 418 while (*c) { 419 v = n | *c; 420 n += 0x100; 421 if ((r = ((v >> 2) ^ v) & 0x0f) != 0) 422 ret = (ret << r) | (ret >> (32 - r)); 423 ret &= 0xFFFFFFFFUL; 424 ret ^= v * v; 425 c++; 426 } 427 return (ret >> 16) ^ ret; 428 } 429 430 unsigned long 431 lh_num_items(const _LHASH *lh) 432 { 433 return lh ? lh->num_items : 0; 434 } 435