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      1 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com)
      2  * All rights reserved.
      3  *
      4  * This package is an SSL implementation written
      5  * by Eric Young (eay (at) 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 (at) 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 (at) 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 (at) 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 #include <openssl/stack.h>
     58 
     59 #include <string.h>
     60 
     61 #include <openssl/mem.h>
     62 
     63 /* kMinSize is the number of pointers that will be initially allocated in a new
     64  * stack. */
     65 static const size_t kMinSize = 4;
     66 
     67 _STACK *sk_new(stack_cmp_func comp) {
     68   _STACK *ret;
     69 
     70   ret = OPENSSL_malloc(sizeof(_STACK));
     71   if (ret == NULL) {
     72     goto err;
     73   }
     74   memset(ret, 0, sizeof(_STACK));
     75 
     76   ret->data = OPENSSL_malloc(sizeof(void *) * kMinSize);
     77   if (ret->data == NULL) {
     78     goto err;
     79   }
     80 
     81   memset(ret->data, 0, sizeof(void *) * kMinSize);
     82 
     83   ret->comp = comp;
     84   ret->num_alloc = kMinSize;
     85 
     86   return ret;
     87 
     88 err:
     89   OPENSSL_free(ret);
     90   return NULL;
     91 }
     92 
     93 _STACK *sk_new_null(void) { return sk_new(NULL); }
     94 
     95 size_t sk_num(const _STACK *sk) {
     96   if (sk == NULL) {
     97     return 0;
     98   }
     99   return sk->num;
    100 }
    101 
    102 void sk_zero(_STACK *sk) {
    103   if (sk == NULL || sk->num == 0) {
    104     return;
    105   }
    106   memset(sk->data, 0, sizeof(void*) * sk->num);
    107   sk->num = 0;
    108   sk->sorted = 0;
    109 }
    110 
    111 void *sk_value(const _STACK *sk, size_t i) {
    112   if (!sk || i >= sk->num) {
    113     return NULL;
    114   }
    115   return sk->data[i];
    116 }
    117 
    118 void *sk_set(_STACK *sk, size_t i, void *value) {
    119   if (!sk || i >= sk->num) {
    120     return NULL;
    121   }
    122   return sk->data[i] = value;
    123 }
    124 
    125 void sk_free(_STACK *sk) {
    126   if (sk == NULL) {
    127     return;
    128   }
    129   OPENSSL_free(sk->data);
    130   OPENSSL_free(sk);
    131 }
    132 
    133 void sk_pop_free(_STACK *sk, void (*func)(void *)) {
    134   size_t i;
    135 
    136   if (sk == NULL) {
    137     return;
    138   }
    139 
    140   for (i = 0; i < sk->num; i++) {
    141     if (sk->data[i] != NULL) {
    142       func(sk->data[i]);
    143     }
    144   }
    145   sk_free(sk);
    146 }
    147 
    148 size_t sk_insert(_STACK *sk, void *p, size_t where) {
    149   if (sk == NULL) {
    150     return 0;
    151   }
    152 
    153   if (sk->num_alloc <= sk->num + 1) {
    154     /* Attempt to double the size of the array. */
    155     size_t new_alloc = sk->num_alloc << 1;
    156     size_t alloc_size = new_alloc * sizeof(void *);
    157     void **data;
    158 
    159     /* If the doubling overflowed, try to increment. */
    160     if (new_alloc < sk->num_alloc || alloc_size / sizeof(void *) != new_alloc) {
    161       new_alloc = sk->num_alloc + 1;
    162       alloc_size = new_alloc * sizeof(void *);
    163     }
    164 
    165     /* If the increment also overflowed, fail. */
    166     if (new_alloc < sk->num_alloc || alloc_size / sizeof(void *) != new_alloc) {
    167       return 0;
    168     }
    169 
    170     data = OPENSSL_realloc(sk->data, alloc_size);
    171     if (data == NULL) {
    172       return 0;
    173     }
    174 
    175     sk->data = data;
    176     sk->num_alloc = new_alloc;
    177   }
    178 
    179   if (where >= sk->num) {
    180     sk->data[sk->num] = p;
    181   } else {
    182     memmove(&sk->data[where + 1], &sk->data[where],
    183             sizeof(void *) * (sk->num - where));
    184     sk->data[where] = p;
    185   }
    186 
    187   sk->num++;
    188   sk->sorted = 0;
    189 
    190   return sk->num;
    191 }
    192 
    193 void *sk_delete(_STACK *sk, size_t where) {
    194   void *ret;
    195 
    196   if (!sk || where >= sk->num) {
    197     return NULL;
    198   }
    199 
    200   ret = sk->data[where];
    201 
    202   if (where != sk->num - 1) {
    203     memmove(&sk->data[where], &sk->data[where + 1],
    204             sizeof(void *) * (sk->num - where - 1));
    205   }
    206 
    207   sk->num--;
    208   return ret;
    209 }
    210 
    211 void *sk_delete_ptr(_STACK *sk, void *p) {
    212   size_t i;
    213 
    214   if (sk == NULL) {
    215     return NULL;
    216   }
    217 
    218   for (i = 0; i < sk->num; i++) {
    219     if (sk->data[i] == p) {
    220       return sk_delete(sk, i);
    221     }
    222   }
    223 
    224   return NULL;
    225 }
    226 
    227 int sk_find(_STACK *sk, size_t *out_index, void *p) {
    228   const void *const *r;
    229   size_t i;
    230   int (*comp_func)(const void *,const void *);
    231 
    232   if (sk == NULL) {
    233     return 0;
    234   }
    235 
    236   if (sk->comp == NULL) {
    237     /* Use pointer equality when no comparison function has been set. */
    238     for (i = 0; i < sk->num; i++) {
    239       if (sk->data[i] == p) {
    240         if (out_index) {
    241           *out_index = i;
    242         }
    243         return 1;
    244       }
    245     }
    246     return 0;
    247   }
    248 
    249   if (p == NULL) {
    250     return 0;
    251   }
    252 
    253   sk_sort(sk);
    254 
    255   /* sk->comp is a function that takes pointers to pointers to elements, but
    256    * qsort and bsearch take a comparison function that just takes pointers to
    257    * elements. However, since we're passing an array of pointers to
    258    * qsort/bsearch, we can just cast the comparison function and everything
    259    * works. */
    260   comp_func=(int (*)(const void *,const void *))(sk->comp);
    261   r = bsearch(&p, sk->data, sk->num, sizeof(void *), comp_func);
    262   if (r == NULL) {
    263     return 0;
    264   }
    265   i = ((void **)r) - sk->data;
    266   /* This function always returns the first result. */
    267   while (i > 0 && sk->comp((const void**) &p, (const void**) &sk->data[i-1]) == 0) {
    268     i--;
    269   }
    270   if (out_index) {
    271     *out_index = i;
    272   }
    273   return 1;
    274 }
    275 
    276 void *sk_shift(_STACK *sk) {
    277   if (sk == NULL) {
    278     return NULL;
    279   }
    280   if (sk->num == 0) {
    281     return NULL;
    282   }
    283   return sk_delete(sk, 0);
    284 }
    285 
    286 size_t sk_push(_STACK *sk, void *p) { return (sk_insert(sk, p, sk->num)); }
    287 
    288 void *sk_pop(_STACK *sk) {
    289   if (sk == NULL) {
    290     return NULL;
    291   }
    292   if (sk->num == 0) {
    293     return NULL;
    294   }
    295   return sk_delete(sk, sk->num - 1);
    296 }
    297 
    298 _STACK *sk_dup(const _STACK *sk) {
    299   _STACK *ret;
    300   void **s;
    301 
    302   if (sk == NULL) {
    303     return NULL;
    304   }
    305 
    306   ret = sk_new(sk->comp);
    307   if (ret == NULL) {
    308     goto err;
    309   }
    310 
    311   s = (void **)OPENSSL_realloc(ret->data, sizeof(void *) * sk->num_alloc);
    312   if (s == NULL) {
    313     goto err;
    314   }
    315   ret->data = s;
    316 
    317   ret->num = sk->num;
    318   memcpy(ret->data, sk->data, sizeof(void *) * sk->num);
    319   ret->sorted = sk->sorted;
    320   ret->num_alloc = sk->num_alloc;
    321   ret->comp = sk->comp;
    322   return ret;
    323 
    324 err:
    325   sk_free(ret);
    326   return NULL;
    327 }
    328 
    329 void sk_sort(_STACK *sk) {
    330   int (*comp_func)(const void *,const void *);
    331 
    332   if (sk == NULL || sk->sorted) {
    333     return;
    334   }
    335 
    336   /* See the comment in sk_find about this cast. */
    337   comp_func = (int (*)(const void *, const void *))(sk->comp);
    338   qsort(sk->data, sk->num, sizeof(void *), comp_func);
    339   sk->sorted = 1;
    340 }
    341 
    342 int sk_is_sorted(const _STACK *sk) {
    343   if (!sk) {
    344     return 1;
    345   }
    346   return sk->sorted;
    347 }
    348 
    349 stack_cmp_func sk_set_cmp_func(_STACK *sk, stack_cmp_func comp) {
    350   stack_cmp_func old = sk->comp;
    351 
    352   if (sk->comp != comp) {
    353     sk->sorted = 0;
    354   }
    355   sk->comp = comp;
    356 
    357   return old;
    358 }
    359 
    360 _STACK *sk_deep_copy(const _STACK *sk, void *(*copy_func)(void *),
    361                      void (*free_func)(void *)) {
    362   _STACK *ret = sk_dup(sk);
    363   if (ret == NULL) {
    364     return NULL;
    365   }
    366 
    367   size_t i;
    368   for (i = 0; i < ret->num; i++) {
    369     if (ret->data[i] == NULL) {
    370       continue;
    371     }
    372     ret->data[i] = copy_func(ret->data[i]);
    373     if (ret->data[i] == NULL) {
    374       size_t j;
    375       for (j = 0; j < i; j++) {
    376         if (ret->data[j] != NULL) {
    377           free_func(ret->data[j]);
    378         }
    379       }
    380       sk_free(ret);
    381       return NULL;
    382     }
    383   }
    384 
    385   return ret;
    386 }
    387