crypto/lhash/lhash.c

   1 /* crypto/lhash/lhash.c */
   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 /*-
  60  * Code for dynamic hash table routines
  61  * Author - Eric Young v 2.0
  62  *
  63  * 2.2 eay - added #include "crypto.h" so the memory leak checking code is
  64  *           present. eay 18-Jun-98
  65  *
  66  * 2.1 eay - Added an 'error in last operation' flag. eay 6-May-98
  67  *
  68  * 2.0 eay - Fixed a bug that occurred when using lh_delete
  69  *           from inside lh_doall().  As entries were deleted,
  70  *           the 'table' was 'contract()ed', making some entries
  71  *           jump from the end of the table to the start, there by
  72  *           skipping the lh_doall() processing. eay - 4/12/95
  73  *
  74  * 1.9 eay - Fixed a memory leak in lh_free, the LHASH_NODEs
  75  *           were not being free()ed. 21/11/95
  76  *
  77  * 1.8 eay - Put the stats routines into a separate file, lh_stats.c
  78  *           19/09/95
  79  *
  80  * 1.7 eay - Removed the fputs() for realloc failures - the code
  81  *           should silently tolerate them.  I have also fixed things
  82  *           lint complained about 04/05/95
  83  *
  84  * 1.6 eay - Fixed an invalid pointers in contract/expand 27/07/92
  85  *
  86  * 1.5 eay - Fixed a misuse of realloc in expand 02/03/1992
  87  *
  88  * 1.4 eay - Fixed lh_doall so the function can call lh_delete 28/05/91
  89  *
  90  * 1.3 eay - Fixed a few lint problems 19/3/1991
  91  *
  92  * 1.2 eay - Fixed lh_doall problem 13/3/1991
  93  *
  94  * 1.1 eay - Added lh_doall
  95  *
  96  * 1.0 eay - First version
  97  */
  98 #include <stdio.h>
  99 #include <string.h>
 100 #include <stdlib.h>
 101 #include <openssl/crypto.h>
 102 #include <openssl/lhash.h>
 103
 104 const char lh_version[] = "lhash" OPENSSL_VERSION_PTEXT;
 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 *lh_new(LHASH_HASH_FN_TYPE h, LHASH_COMP_FN_TYPE c)
 116 {
 117     _LHASH *ret;
 118     int i;
 119
 120     if ((ret = OPENSSL_malloc(sizeof(_LHASH))) == NULL)
 121         goto err0;
 122     if ((ret->b = OPENSSL_malloc(sizeof(LHASH_NODE *) * MIN_NODES)) == NULL)
 123         goto err1;
 124     for (i = 0; i < MIN_NODES; i++)
 125         ret->b[i] = NULL;
 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->p = 0;
 131     ret->pmax = MIN_NODES / 2;
 132     ret->up_load = UP_LOAD;
 133     ret->down_load = DOWN_LOAD;
 134     ret->num_items = 0;
 135
 136     ret->num_expands = 0;
 137     ret->num_expand_reallocs = 0;
 138     ret->num_contracts = 0;
 139     ret->num_contract_reallocs = 0;
 140     ret->num_hash_calls = 0;
 141     ret->num_comp_calls = 0;
 142     ret->num_insert = 0;
 143     ret->num_replace = 0;
 144     ret->num_delete = 0;
 145     ret->num_no_delete = 0;
 146     ret->num_retrieve = 0;
 147     ret->num_retrieve_miss = 0;
 148     ret->num_hash_comps = 0;
 149
 150     ret->error = 0;
 151     return (ret);
 152  err1:
 153     OPENSSL_free(ret);
 154  err0:
 155     return (NULL);
 156 }
 157
 158 void lh_free(_LHASH *lh)
 159 {
 160     unsigned int i;
 161     LHASH_NODE *n, *nn;
 162
 163     if (lh == NULL)
 164         return;
 165
 166     for (i = 0; i < lh->num_nodes; i++) {
 167         n = lh->b[i];
 168         while (n != NULL) {
 169             nn = n->next;
 170             OPENSSL_free(n);
 171             n = nn;
 172         }
 173     }
 174     OPENSSL_free(lh->b);
 175     OPENSSL_free(lh);
 176 }
 177
 178 void *lh_insert(_LHASH *lh, void *data)
 179 {
 180     unsigned long hash;
 181     LHASH_NODE *nn, **rn;
 182     void *ret;
 183
 184     lh->error = 0;
 185     if (lh->up_load <= (lh->num_items * LH_LOAD_MULT / lh->num_nodes))
 186         expand(lh);
 187
 188     rn = getrn(lh, data, &hash);
 189
 190     if (*rn == NULL) {
 191         if ((nn = (LHASH_NODE *)OPENSSL_malloc(sizeof(LHASH_NODE))) == NULL) {
 192             lh->error++;
 193             return (NULL);
 194         }
 195         nn->data = data;
 196         nn->next = NULL;
 197 #ifndef OPENSSL_NO_HASH_COMP
 198         nn->hash = hash;
 199 #endif
 200         *rn = nn;
 201         ret = NULL;
 202         lh->num_insert++;
 203         lh->num_items++;
 204     } else {                    /* replace same key */
 205
 206         ret = (*rn)->data;
 207         (*rn)->data = data;
 208         lh->num_replace++;
 209     }
 210     return (ret);
 211 }
 212
 213 void *lh_delete(_LHASH *lh, const void *data)
 214 {
 215     unsigned long hash;
 216     LHASH_NODE *nn, **rn;
 217     void *ret;
 218
 219     lh->error = 0;
 220     rn = getrn(lh, data, &hash);
 221
 222     if (*rn == NULL) {
 223         lh->num_no_delete++;
 224         return (NULL);
 225     } else {
 226         nn = *rn;
 227         *rn = nn->next;
 228         ret = nn->data;
 229         OPENSSL_free(nn);
 230         lh->num_delete++;
 231     }
 232
 233     lh->num_items--;
 234     if ((lh->num_nodes > MIN_NODES) &&
 235         (lh->down_load >= (lh->num_items * LH_LOAD_MULT / lh->num_nodes)))
 236         contract(lh);
 237
 238     return (ret);
 239 }
 240
 241 void *lh_retrieve(_LHASH *lh, const void *data)
 242 {
 243     unsigned long hash;
 244     LHASH_NODE **rn;
 245     void *ret;
 246
 247     lh->error = 0;
 248     rn = getrn(lh, data, &hash);
 249
 250     if (*rn == NULL) {
 251         lh->num_retrieve_miss++;
 252         return (NULL);
 253     } else {
 254         ret = (*rn)->data;
 255         lh->num_retrieve++;
 256     }
 257     return (ret);
 258 }
 259
 260 static void doall_util_fn(_LHASH *lh, int use_arg, LHASH_DOALL_FN_TYPE func,
 261                           LHASH_DOALL_ARG_FN_TYPE func_arg, void *arg)
 262 {
 263     int i;
 264     LHASH_NODE *a, *n;
 265
 266     if (lh == NULL)
 267         return;
 268
 269     /*
 270      * reverse the order so we search from 'top to bottom' We were having
 271      * memory leaks otherwise
 272      */
 273     for (i = lh->num_nodes - 1; i >= 0; i--) {
 274         a = lh->b[i];
 275         while (a != NULL) {
 276             /*
 277              * 28/05/91 - eay - n added so items can be deleted via lh_doall
 278              */
 279             /*
 280              * 22/05/08 - ben - eh? since a is not passed, this should not be
 281              * needed
 282              */
 283             n = a->next;
 284             if (use_arg)
 285                 func_arg(a->data, arg);
 286             else
 287                 func(a->data);
 288             a = n;
 289         }
 290     }
 291 }
 292
 293 void lh_doall(_LHASH *lh, LHASH_DOALL_FN_TYPE func)
 294 {
 295     doall_util_fn(lh, 0, func, (LHASH_DOALL_ARG_FN_TYPE)0, NULL);
 296 }
 297
 298 void lh_doall_arg(_LHASH *lh, LHASH_DOALL_ARG_FN_TYPE func, void *arg)
 299 {
 300     doall_util_fn(lh, 1, (LHASH_DOALL_FN_TYPE)0, func, arg);
 301 }
 302
 303 static void expand(_LHASH *lh)
 304 {
 305     LHASH_NODE **n, **n1, **n2, *np;
 306     unsigned int p, i, j;
 307     unsigned long hash, nni;
 308
 309     lh->num_nodes++;
 310     lh->num_expands++;
 311     p = (int)lh->p++;
 312     n1 = &(lh->b[p]);
 313     n2 = &(lh->b[p + (int)lh->pmax]);
 314     *n2 = NULL;                 /* 27/07/92 - eay - undefined pointer bug */
 315     nni = lh->num_alloc_nodes;
 316
 317     for (np = *n1; np != NULL;) {
 318 #ifndef OPENSSL_NO_HASH_COMP
 319         hash = np->hash;
 320 #else
 321         hash = lh->hash(np->data);
 322         lh->num_hash_calls++;
 323 #endif
 324         if ((hash % nni) != p) { /* move it */
 325             *n1 = (*n1)->next;
 326             np->next = *n2;
 327             *n2 = np;
 328         } else
 329             n1 = &((*n1)->next);
 330         np = *n1;
 331     }
 332
 333     if ((lh->p) >= lh->pmax) {
 334         j = (int)lh->num_alloc_nodes * 2;
 335         n = (LHASH_NODE **)OPENSSL_realloc(lh->b,
 336                                            (int)(sizeof(LHASH_NODE *) * j));
 337         if (n == NULL) {
 338 /*                      fputs("realloc error in lhash",stderr); */
 339             lh->error++;
 340             lh->p = 0;
 341             return;
 342         }
 343         /* else */
 344         for (i = (int)lh->num_alloc_nodes; i < j; i++) /* 26/02/92 eay */
 345             n[i] = NULL;        /* 02/03/92 eay */
 346         lh->pmax = lh->num_alloc_nodes;
 347         lh->num_alloc_nodes = j;
 348         lh->num_expand_reallocs++;
 349         lh->p = 0;
 350         lh->b = n;
 351     }
 352 }
 353
 354 static void contract(_LHASH *lh)
 355 {
 356     LHASH_NODE **n, *n1, *np;
 357
 358     np = lh->b[lh->p + lh->pmax - 1];
 359     lh->b[lh->p + lh->pmax - 1] = NULL; /* 24/07-92 - eay - weird but :-( */
 360     if (lh->p == 0) {
 361         n = (LHASH_NODE **)OPENSSL_realloc(lh->b,
 362                                            (unsigned int)(sizeof(LHASH_NODE *)
 363                                                           * lh->pmax));
 364         if (n == NULL) {
 365 /*                      fputs("realloc error in lhash",stderr); */
 366             lh->error++;
 367             return;
 368         }
 369         lh->num_contract_reallocs++;
 370         lh->num_alloc_nodes /= 2;
 371         lh->pmax /= 2;
 372         lh->p = lh->pmax - 1;
 373         lh->b = n;
 374     } else
 375         lh->p--;
 376
 377     lh->num_nodes--;
 378     lh->num_contracts++;
 379
 380     n1 = lh->b[(int)lh->p];
 381     if (n1 == NULL)
 382         lh->b[(int)lh->p] = np;
 383     else {
 384         while (n1->next != NULL)
 385             n1 = n1->next;
 386         n1->next = np;
 387     }
 388 }
 389
 390 static LHASH_NODE **getrn(_LHASH *lh, const void *data, unsigned long *rhash)
 391 {
 392     LHASH_NODE **ret, *n1;
 393     unsigned long hash, nn;
 394     LHASH_COMP_FN_TYPE cf;
 395
 396     hash = (*(lh->hash)) (data);
 397     lh->num_hash_calls++;
 398     *rhash = hash;
 399
 400     nn = hash % lh->pmax;
 401     if (nn < lh->p)
 402         nn = hash % lh->num_alloc_nodes;
 403
 404     cf = lh->comp;
 405     ret = &(lh->b[(int)nn]);
 406     for (n1 = *ret; n1 != NULL; n1 = n1->next) {
 407 #ifndef OPENSSL_NO_HASH_COMP
 408         lh->num_hash_comps++;
 409         if (n1->hash != hash) {
 410             ret = &(n1->next);
 411             continue;
 412         }
 413 #endif
 414         lh->num_comp_calls++;
 415         if (cf(n1->data, data) == 0)
 416             break;
 417         ret = &(n1->next);
 418     }
 419     return (ret);
 420 }
 421
 422 /*
 423  * The following hash seems to work very well on normal text strings no
 424  * collisions on /usr/dict/words and it distributes on %2^n quite well, not
 425  * as good as MD5, but still good.
 426  */
 427 unsigned long lh_strhash(const char *c)
 428 {
 429     unsigned long ret = 0;
 430     long n;
 431     unsigned long v;
 432     int r;
 433
 434     if ((c == NULL) || (*c == '\0'))
 435         return (ret);
 436 /*-
 437         unsigned char b[16];
 438         MD5(c,strlen(c),b);
 439         return(b[0]|(b[1]<<8)|(b[2]<<16)|(b[3]<<24));
 440 */
 441
 442     n = 0x100;
 443     while (*c) {
 444         v = n | (*c);
 445         n += 0x100;
 446         r = (int)((v >> 2) ^ v) & 0x0f;
 447         ret = (ret << r) | (ret >> (32 - r));
 448         ret &= 0xFFFFFFFFL;
 449         ret ^= v * v;
 450         c++;
 451     }
 452     return ((ret >> 16) ^ ret);
 453 }
 454
 455 unsigned long lh_num_items(const _LHASH *lh)
 456 {
 457     return lh ? lh->num_items : 0;
 458 }