1 /* $OpenBSD: lhash.c,v 1.18 2016/11/08 20:20:06 miod 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 int i; 120 121 if ((ret = malloc(sizeof(_LHASH))) == NULL) 122 goto err0; 123 if ((ret->b = reallocarray(NULL, MIN_NODES, sizeof(LHASH_NODE *))) == NULL) 124 goto err1; 125 for (i = 0; i < MIN_NODES; i++) 126 ret->b[i] = NULL; 127 ret->comp = ((c == NULL) ? (LHASH_COMP_FN_TYPE)strcmp : c); 128 ret->hash = ((h == NULL) ? (LHASH_HASH_FN_TYPE)lh_strhash : h); 129 ret->num_nodes = MIN_NODES / 2; 130 ret->num_alloc_nodes = MIN_NODES; 131 ret->p = 0; 132 ret->pmax = MIN_NODES / 2; 133 ret->up_load = UP_LOAD; 134 ret->down_load = DOWN_LOAD; 135 ret->num_items = 0; 136 137 ret->num_expands = 0; 138 ret->num_expand_reallocs = 0; 139 ret->num_contracts = 0; 140 ret->num_contract_reallocs = 0; 141 ret->num_hash_calls = 0; 142 ret->num_comp_calls = 0; 143 ret->num_insert = 0; 144 ret->num_replace = 0; 145 ret->num_delete = 0; 146 ret->num_no_delete = 0; 147 ret->num_retrieve = 0; 148 ret->num_retrieve_miss = 0; 149 ret->num_hash_comps = 0; 150 151 ret->error = 0; 152 return (ret); 153 154 err1: 155 free(ret); 156 err0: 157 return (NULL); 158 } 159 160 void 161 lh_free(_LHASH *lh) 162 { 163 unsigned int i; 164 LHASH_NODE *n, *nn; 165 166 if (lh == NULL) 167 return; 168 169 for (i = 0; i < lh->num_nodes; i++) { 170 n = lh->b[i]; 171 while (n != NULL) { 172 nn = n->next; 173 free(n); 174 n = nn; 175 } 176 } 177 free(lh->b); 178 free(lh); 179 } 180 181 void * 182 lh_insert(_LHASH *lh, void *data) 183 { 184 unsigned long hash; 185 LHASH_NODE *nn, **rn; 186 void *ret; 187 188 lh->error = 0; 189 if (lh->up_load <= (lh->num_items * LH_LOAD_MULT / lh->num_nodes)) 190 expand(lh); 191 192 rn = getrn(lh, data, &hash); 193 194 if (*rn == NULL) { 195 if ((nn = malloc(sizeof(LHASH_NODE))) == NULL) { 196 lh->error++; 197 return (NULL); 198 } 199 nn->data = data; 200 nn->next = NULL; 201 #ifndef OPENSSL_NO_HASH_COMP 202 nn->hash = hash; 203 #endif 204 *rn = nn; 205 ret = NULL; 206 lh->num_insert++; 207 lh->num_items++; 208 } 209 else /* replace same key */ 210 { 211 ret = (*rn)->data; 212 (*rn)->data = data; 213 lh->num_replace++; 214 } 215 return (ret); 216 } 217 218 void * 219 lh_delete(_LHASH *lh, const void *data) 220 { 221 unsigned long hash; 222 LHASH_NODE *nn, **rn; 223 void *ret; 224 225 lh->error = 0; 226 rn = getrn(lh, data, &hash); 227 228 if (*rn == NULL) { 229 lh->num_no_delete++; 230 return (NULL); 231 } else { 232 nn= *rn; 233 *rn = nn->next; 234 ret = nn->data; 235 free(nn); 236 lh->num_delete++; 237 } 238 239 lh->num_items--; 240 if ((lh->num_nodes > MIN_NODES) && 241 (lh->down_load >= (lh->num_items * LH_LOAD_MULT / lh->num_nodes))) 242 contract(lh); 243 244 return (ret); 245 } 246 247 void * 248 lh_retrieve(_LHASH *lh, const void *data) 249 { 250 unsigned long hash; 251 LHASH_NODE **rn; 252 void *ret; 253 254 lh->error = 0; 255 rn = getrn(lh, data, &hash); 256 257 if (*rn == NULL) { 258 lh->num_retrieve_miss++; 259 return (NULL); 260 } else { 261 ret = (*rn)->data; 262 lh->num_retrieve++; 263 } 264 return (ret); 265 } 266 267 static void 268 doall_util_fn(_LHASH *lh, int use_arg, LHASH_DOALL_FN_TYPE func, 269 LHASH_DOALL_ARG_FN_TYPE func_arg, void *arg) 270 { 271 int i; 272 LHASH_NODE *a, *n; 273 274 if (lh == NULL) 275 return; 276 277 /* reverse the order so we search from 'top to bottom' 278 * We were having memory leaks otherwise */ 279 for (i = lh->num_nodes - 1; i >= 0; i--) { 280 a = lh->b[i]; 281 while (a != NULL) { 282 /* 28/05/91 - eay - n added so items can be deleted 283 * via lh_doall */ 284 /* 22/05/08 - ben - eh? since a is not passed, 285 * this should not be needed */ 286 n = a->next; 287 if (use_arg) 288 func_arg(a->data, arg); 289 else 290 func(a->data); 291 a = n; 292 } 293 } 294 } 295 296 void 297 lh_doall(_LHASH *lh, LHASH_DOALL_FN_TYPE func) 298 { 299 doall_util_fn(lh, 0, func, (LHASH_DOALL_ARG_FN_TYPE)0, NULL); 300 } 301 302 void 303 lh_doall_arg(_LHASH *lh, LHASH_DOALL_ARG_FN_TYPE func, void *arg) 304 { 305 doall_util_fn(lh, 1, (LHASH_DOALL_FN_TYPE)0, func, arg); 306 } 307 308 static void 309 expand(_LHASH *lh) 310 { 311 LHASH_NODE **n, **n1, **n2, *np; 312 unsigned int p, i, j; 313 unsigned long hash, nni; 314 315 lh->num_nodes++; 316 lh->num_expands++; 317 p = (int)lh->p++; 318 n1 = &(lh->b[p]); 319 n2 = &(lh->b[p + (int)lh->pmax]); 320 *n2 = NULL; /* 27/07/92 - eay - undefined pointer bug */ 321 nni = lh->num_alloc_nodes; 322 323 for (np = *n1; np != NULL; ) { 324 #ifndef OPENSSL_NO_HASH_COMP 325 hash = np->hash; 326 #else 327 hash = lh->hash(np->data); 328 lh->num_hash_calls++; 329 #endif 330 if ((hash % nni) != p) { /* move it */ 331 *n1 = (*n1)->next; 332 np->next= *n2; 333 *n2 = np; 334 } else 335 n1 = &((*n1)->next); 336 np= *n1; 337 } 338 339 if ((lh->p) >= lh->pmax) { 340 j = (int)lh->num_alloc_nodes * 2; 341 n = reallocarray(lh->b, j, sizeof(LHASH_NODE *)); 342 if (n == NULL) { 343 /* fputs("realloc error in lhash", stderr); */ 344 lh->error++; 345 lh->p = 0; 346 return; 347 } 348 /* else */ 349 for (i = (int)lh->num_alloc_nodes; i < j; i++)/* 26/02/92 eay */ 350 n[i] = NULL; /* 02/03/92 eay */ 351 lh->pmax = lh->num_alloc_nodes; 352 lh->num_alloc_nodes = j; 353 lh->num_expand_reallocs++; 354 lh->p = 0; 355 lh->b = n; 356 } 357 } 358 359 static void 360 contract(_LHASH *lh) 361 { 362 LHASH_NODE **n, *n1, *np; 363 364 np = lh->b[lh->p + lh->pmax - 1]; 365 lh->b[lh->p+lh->pmax - 1] = NULL; /* 24/07-92 - eay - weird but :-( */ 366 if (lh->p == 0) { 367 n = reallocarray(lh->b, lh->pmax, sizeof(LHASH_NODE *)); 368 if (n == NULL) { 369 /* fputs("realloc error in lhash", stderr); */ 370 lh->error++; 371 return; 372 } 373 lh->num_contract_reallocs++; 374 lh->num_alloc_nodes /= 2; 375 lh->pmax /= 2; 376 lh->p = lh->pmax - 1; 377 lh->b = n; 378 } else 379 lh->p--; 380 381 lh->num_nodes--; 382 lh->num_contracts++; 383 384 n1 = lh->b[(int)lh->p]; 385 if (n1 == NULL) 386 lh->b[(int)lh->p] = np; 387 else { 388 while (n1->next != NULL) 389 n1 = n1->next; 390 n1->next = np; 391 } 392 } 393 394 static LHASH_NODE **getrn(_LHASH *lh, const void *data, unsigned long *rhash) 395 { 396 LHASH_NODE **ret, *n1; 397 unsigned long hash, nn; 398 LHASH_COMP_FN_TYPE cf; 399 400 hash = (*(lh->hash))(data); 401 lh->num_hash_calls++; 402 *rhash = hash; 403 404 nn = hash % lh->pmax; 405 if (nn < lh->p) 406 nn = hash % lh->num_alloc_nodes; 407 408 cf = lh->comp; 409 ret = &(lh->b[(int)nn]); 410 for (n1 = *ret; n1 != NULL; n1 = n1->next) { 411 #ifndef OPENSSL_NO_HASH_COMP 412 lh->num_hash_comps++; 413 if (n1->hash != hash) { 414 ret = &(n1->next); 415 continue; 416 } 417 #endif 418 lh->num_comp_calls++; 419 if (cf(n1->data, data) == 0) 420 break; 421 ret = &(n1->next); 422 } 423 return (ret); 424 } 425 426 /* The following hash seems to work very well on normal text strings 427 * no collisions on /usr/dict/words and it distributes on %2^n quite 428 * well, not as good as MD5, but still good. 429 */ 430 unsigned long 431 lh_strhash(const char *c) 432 { 433 unsigned long ret = 0; 434 unsigned long n, v; 435 unsigned int r; 436 437 if (c == NULL || *c == '\0') 438 return ret; 439 440 n = 0x100; 441 while (*c) { 442 v = n | *c; 443 n += 0x100; 444 if ((r = ((v >> 2) ^ v) & 0x0f) != 0) 445 ret = (ret << r) | (ret >> (32 - r)); 446 ret &= 0xFFFFFFFFUL; 447 ret ^= v * v; 448 c++; 449 } 450 return (ret >> 16) ^ ret; 451 } 452 453 unsigned long 454 lh_num_items(const _LHASH *lh) 455 { 456 return lh ? lh->num_items : 0; 457 } 458