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 /* 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 #include <openssl/crypto.h>
 101 #include <openssl/lhash.h>
 102
 103 const char *lh_version="lhash" OPENSSL_VERSION_PTEXT;
 104
 105 #undef MIN_NODES
 106 #define MIN_NODES       16
 107 #define UP_LOAD         (2*LH_LOAD_MULT) /* load times 256  (default 2) */
 108 #define DOWN_LOAD       (LH_LOAD_MULT)   /* load times 256  (default 1) */
 109
 110 static void expand(LHASH *lh);
 111 static void contract(LHASH *lh);
 112 static LHASH_NODE **getrn(LHASH *lh, const void *data, unsigned long *rhash);
 113
 114 LHASH *lh_new(LHASH_HASH_FN_TYPE h, LHASH_COMP_FN_TYPE c)
 115         {
 116         LHASH *ret;
 117         int i;
 118
 119         if ((ret=(LHASH *)OPENSSL_malloc(sizeof(LHASH))) == NULL)
 120                 goto err0;
 121         if ((ret->b=(LHASH_NODE **)OPENSSL_malloc(sizeof(LHASH_NODE *)*MIN_NODES)) == NULL)
 122                 goto err1;
 123         for (i=0; i<MIN_NODES; i++)
 124                 ret->b[i]=NULL;
 125         ret->comp=((c == NULL)?(LHASH_COMP_FN_TYPE)strcmp:c);
 126         ret->hash=((h == NULL)?(LHASH_HASH_FN_TYPE)lh_strhash:h);
 127         ret->num_nodes=MIN_NODES/2;
 128         ret->num_alloc_nodes=MIN_NODES;
 129         ret->p=0;
 130         ret->pmax=MIN_NODES/2;
 131         ret->up_load=UP_LOAD;
 132         ret->down_load=DOWN_LOAD;
 133         ret->num_items=0;
 134
 135         ret->num_expands=0;
 136         ret->num_expand_reallocs=0;
 137         ret->num_contracts=0;
 138         ret->num_contract_reallocs=0;
 139         ret->num_hash_calls=0;
 140         ret->num_comp_calls=0;
 141         ret->num_insert=0;
 142         ret->num_replace=0;
 143         ret->num_delete=0;
 144         ret->num_no_delete=0;
 145         ret->num_retrieve=0;
 146         ret->num_retrieve_miss=0;
 147         ret->num_hash_comps=0;
 148
 149         ret->error=0;
 150         return(ret);
 151 err1:
 152         OPENSSL_free(ret);
 153 err0:
 154         return(NULL);
 155         }
 156
 157 void lh_free(LHASH *lh)
 158         {
 159         unsigned int i;
 160         LHASH_NODE *n,*nn;
 161
 162         if (lh == NULL)
 163             return;
 164
 165         for (i=0; i<lh->num_nodes; i++)
 166                 {
 167                 n=lh->b[i];
 168                 while (n != NULL)
 169                         {
 170                         nn=n->next;
 171                         OPENSSL_free(n);
 172                         n=nn;
 173                         }
 174                 }
 175         OPENSSL_free(lh->b);
 176         OPENSSL_free(lh);
 177         }
 178
 179 void *lh_insert(LHASH *lh, void *data)
 180         {
 181         unsigned long hash;
 182         LHASH_NODE *nn,**rn;
 183         const void *ret;
 184
 185         lh->error=0;
 186         if (lh->up_load <= (lh->num_items*LH_LOAD_MULT/lh->num_nodes))
 187                 expand(lh);
 188
 189         rn=getrn(lh,data,&hash);
 190
 191         if (*rn == NULL)
 192                 {
 193                 if ((nn=(LHASH_NODE *)OPENSSL_malloc(sizeof(LHASH_NODE))) == NULL)
 194                         {
 195                         lh->error++;
 196                         return(NULL);
 197                         }
 198                 nn->data=data;
 199                 nn->next=NULL;
 200 #ifndef OPENSSL_NO_HASH_COMP
 201                 nn->hash=hash;
 202 #endif
 203                 *rn=nn;
 204                 ret=NULL;
 205                 lh->num_insert++;
 206                 lh->num_items++;
 207                 }
 208         else /* replace same key */
 209                 {
 210                 ret= (*rn)->data;
 211                 (*rn)->data=data;
 212                 lh->num_replace++;
 213                 }
 214         return((void *)ret);
 215         }
 216
 217 void *lh_delete(LHASH *lh, const void *data)
 218         {
 219         unsigned long hash;
 220         LHASH_NODE *nn,**rn;
 221         const void *ret;
 222
 223         lh->error=0;
 224         rn=getrn(lh,data,&hash);
 225
 226         if (*rn == NULL)
 227                 {
 228                 lh->num_no_delete++;
 229                 return(NULL);
 230                 }
 231         else
 232                 {
 233                 nn= *rn;
 234                 *rn=nn->next;
 235                 ret=nn->data;
 236                 OPENSSL_free(nn);
 237                 lh->num_delete++;
 238                 }
 239
 240         lh->num_items--;
 241         if ((lh->num_nodes > MIN_NODES) &&
 242                 (lh->down_load >= (lh->num_items*LH_LOAD_MULT/lh->num_nodes)))
 243                 contract(lh);
 244
 245         return((void *)ret);
 246         }
 247
 248 void *lh_retrieve(LHASH *lh, const void *data)
 249         {
 250         unsigned long hash;
 251         LHASH_NODE **rn;
 252         const void *ret;
 253
 254         lh->error=0;
 255         rn=getrn(lh,data,&hash);
 256
 257         if (*rn == NULL)
 258                 {
 259                 lh->num_retrieve_miss++;
 260                 return(NULL);
 261                 }
 262         else
 263                 {
 264                 ret= (*rn)->data;
 265                 lh->num_retrieve++;
 266                 }
 267         return((void *)ret);
 268         }
 269
 270 static void doall_util_fn(LHASH *lh, int use_arg, LHASH_DOALL_FN_TYPE func,
 271                           LHASH_DOALL_ARG_FN_TYPE func_arg, void *arg)
 272         {
 273         int i;
 274         LHASH_NODE *a,*n;
 275
 276         /* reverse the order so we search from 'top to bottom'
 277          * We were having memory leaks otherwise */
 278         for (i=lh->num_nodes-1; i>=0; i--)
 279                 {
 280                 a=lh->b[i];
 281                 while (a != NULL)
 282                         {
 283                         /* 28/05/91 - eay - n added so items can be deleted
 284                          * via lh_doall */
 285                         n=a->next;
 286                         if(use_arg)
 287                                 func_arg(a->data,arg);
 288                         else
 289                                 func(a->data);
 290                         a=n;
 291                         }
 292                 }
 293         }
 294
 295 void lh_doall(LHASH *lh, LHASH_DOALL_FN_TYPE func)
 296         {
 297         doall_util_fn(lh, 0, func, (LHASH_DOALL_ARG_FN_TYPE)0, NULL);
 298         }
 299
 300 void lh_doall_arg(LHASH *lh, LHASH_DOALL_ARG_FN_TYPE func, void *arg)
 301         {
 302         doall_util_fn(lh, 1, (LHASH_DOALL_FN_TYPE)0, func, arg);
 303         }
 304
 305 static void expand(LHASH *lh)
 306         {
 307         LHASH_NODE **n,**n1,**n2,*np;
 308         unsigned int p,i,j;
 309         unsigned long hash,nni;
 310
 311         lh->num_nodes++;
 312         lh->num_expands++;
 313         p=(int)lh->p++;
 314         n1= &(lh->b[p]);
 315         n2= &(lh->b[p+(int)lh->pmax]);
 316         *n2=NULL;        /* 27/07/92 - eay - undefined pointer bug */
 317         nni=lh->num_alloc_nodes;
 318
 319         for (np= *n1; np != NULL; )
 320                 {
 321 #ifndef OPENSSL_NO_HASH_COMP
 322                 hash=np->hash;
 323 #else
 324                 hash=lh->hash(np->data);
 325                 lh->num_hash_calls++;
 326 #endif
 327                 if ((hash%nni) != p)
 328                         { /* move it */
 329                         *n1= (*n1)->next;
 330                         np->next= *n2;
 331                         *n2=np;
 332                         }
 333                 else
 334                         n1= &((*n1)->next);
 335                 np= *n1;
 336                 }
 337
 338         if ((lh->p) >= lh->pmax)
 339                 {
 340                 j=(int)lh->num_alloc_nodes*2;
 341                 n=(LHASH_NODE **)OPENSSL_realloc(lh->b,
 342                         (unsigned int)sizeof(LHASH_NODE *)*j);
 343                 if (n == NULL)
 344                         {
 345 /*                      fputs("realloc error in lhash",stderr); */
 346                         lh->error++;
 347                         lh->p=0;
 348                         return;
 349                         }
 350                 /* else */
 351                 for (i=(int)lh->num_alloc_nodes; i<j; i++)/* 26/02/92 eay */
 352                         n[i]=NULL;                        /* 02/03/92 eay */
 353                 lh->pmax=lh->num_alloc_nodes;
 354                 lh->num_alloc_nodes=j;
 355                 lh->num_expand_reallocs++;
 356                 lh->p=0;
 357                 lh->b=n;
 358                 }
 359         }
 360
 361 static void contract(LHASH *lh)
 362         {
 363         LHASH_NODE **n,*n1,*np;
 364
 365         np=lh->b[lh->p+lh->pmax-1];
 366         lh->b[lh->p+lh->pmax-1]=NULL; /* 24/07-92 - eay - weird but :-( */
 367         if (lh->p == 0)
 368                 {
 369                 n=(LHASH_NODE **)OPENSSL_realloc(lh->b,
 370                         (unsigned int)(sizeof(LHASH_NODE *)*lh->pmax));
 371                 if (n == NULL)
 372                         {
 373 /*                      fputs("realloc error in lhash",stderr); */
 374                         lh->error++;
 375                         return;
 376                         }
 377                 lh->num_contract_reallocs++;
 378                 lh->num_alloc_nodes/=2;
 379                 lh->pmax/=2;
 380                 lh->p=lh->pmax-1;
 381                 lh->b=n;
 382                 }
 383         else
 384                 lh->p--;
 385
 386         lh->num_nodes--;
 387         lh->num_contracts++;
 388
 389         n1=lh->b[(int)lh->p];
 390         if (n1 == NULL)
 391                 lh->b[(int)lh->p]=np;
 392         else
 393                 {
 394                 while (n1->next != NULL)
 395                         n1=n1->next;
 396                 n1->next=np;
 397                 }
 398         }
 399
 400 static LHASH_NODE **getrn(LHASH *lh, const void *data, unsigned long *rhash)
 401         {
 402         LHASH_NODE **ret,*n1;
 403         unsigned long hash,nn;
 404         LHASH_COMP_FN_TYPE cf;
 405
 406         hash=(*(lh->hash))(data);
 407         lh->num_hash_calls++;
 408         *rhash=hash;
 409
 410         nn=hash%lh->pmax;
 411         if (nn < lh->p)
 412                 nn=hash%lh->num_alloc_nodes;
 413
 414         cf=lh->comp;
 415         ret= &(lh->b[(int)nn]);
 416         for (n1= *ret; n1 != NULL; n1=n1->next)
 417                 {
 418 #ifndef OPENSSL_NO_HASH_COMP
 419                 lh->num_hash_comps++;
 420                 if (n1->hash != hash)
 421                         {
 422                         ret= &(n1->next);
 423                         continue;
 424                         }
 425 #endif
 426                 lh->num_comp_calls++;
 427                 if(cf(n1->data,data) == 0)
 428                         break;
 429                 ret= &(n1->next);
 430                 }
 431         return(ret);
 432         }
 433
 434 /* The following hash seems to work very well on normal text strings
 435  * no collisions on /usr/dict/words and it distributes on %2^n quite
 436  * well, not as good as MD5, but still good.
 437  */
 438 unsigned long lh_strhash(const char *c)
 439         {
 440         unsigned long ret=0;
 441         long n;
 442         unsigned long v;
 443         int r;
 444
 445         if ((c == NULL) || (*c == '\0'))
 446                 return(ret);
 447 /*
 448         unsigned char b[16];
 449         MD5(c,strlen(c),b);
 450         return(b[0]|(b[1]<<8)|(b[2]<<16)|(b[3]<<24));
 451 */
 452
 453         n=0x100;
 454         while (*c)
 455                 {
 456                 v=n|(*c);
 457                 n+=0x100;
 458                 r= (int)((v>>2)^v)&0x0f;
 459                 ret=(ret<<r)|(ret>>(32-r));
 460                 ret&=0xFFFFFFFFL;
 461                 ret^=v*v;
 462                 c++;
 463                 }
 464         return((ret>>16)^ret);
 465         }
 466
 467 unsigned long lh_num_items(const LHASH *lh)
 468         {
 469         return lh ? lh->num_items : 0;
 470         }