/* $OpenBSD: stack.c,v 1.20 2018/04/01 00:36:28 schwarze Exp $ */

/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)

 * All rights reserved.

 *

 * This package is an SSL implementation written

 * by Eric Young (eay@cryptsoft.com).

 * The implementation was written so as to conform with Netscapes SSL.

 *

 * This library is free for commercial and non-commercial use as long as

 * the following conditions are aheared to.  The following conditions

 * apply to all code found in this distribution, be it the RC4, RSA,

 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation

 * included with this distribution is covered by the same copyright terms

 * except that the holder is Tim Hudson (tjh@cryptsoft.com).

 *

 * Copyright remains Eric Young's, and as such any Copyright notices in

 * the code are not to be removed.

 * If this package is used in a product, Eric Young should be given attribution

 * as the author of the parts of the library used.

 * This can be in the form of a textual message at program startup or

 * in documentation (online or textual) provided with the package.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. All advertising materials mentioning features or use of this software

 *    must display the following acknowledgement:

 *    "This product includes cryptographic software written by

 *     Eric Young (eay@cryptsoft.com)"

 *    The word 'cryptographic' can be left out if the rouines from the library

 *    being used are not cryptographic related :-).

 * 4. If you include any Windows specific code (or a derivative thereof) from

 *    the apps directory (application code) you must include an acknowledgement:

 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"

 *

 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 *

 * The licence and distribution terms for any publically available version or

 * derivative of this code cannot be changed.  i.e. this code cannot simply be

 * copied and put under another distribution licence

 * [including the GNU Public Licence.]

 */

#include <stdio.h>

#include <string.h>

#include <openssl/objects.h>

#include <openssl/stack.h>

#undef MIN_NODES

#define MIN_NODES 4

#include <errno.h>

int

(*sk_set_cmp_func(_STACK *sk, int (*c)(const void *, const void *)))(

    const void *, const void *)

{

  int (*old)(const void *, const void *) = sk->comp;

  if (sk->comp != c)

    sk->sorted = 0;

  sk->comp = c;

  return old;

}

_STACK *

sk_dup(_STACK *sk)

{

  _STACK *ret;

  char **s;

  if ((ret = sk_new(sk->comp)) == NULL)

    goto err;

  s = reallocarray(ret->data, sk->num_alloc, sizeof(char *));

  if (s == NULL)

    goto err;

  ret->data = s;

  ret->num = sk->num;

  memcpy(ret->data, sk->data, sizeof(char *) * sk->num);

  ret->sorted = sk->sorted;

  ret->num_alloc = sk->num_alloc;

  ret->comp = sk->comp;

  return (ret);

err:

  if (ret)

    sk_free(ret);

  return (NULL);

}

_STACK *

sk_new_null(void)

{

  return sk_new((int (*)(const void *, const void *))0);

}

_STACK *

sk_new(int (*c)(const void *, const void *))

{

  _STACK *ret;

  int i;

  if ((ret = malloc(sizeof(_STACK))) == NULL)

    goto err;

  if ((ret->data = reallocarray(NULL, MIN_NODES, sizeof(char *))) == NULL)

    goto err;

  for (i = 0; i < MIN_NODES; i++)

    ret->data[i] = NULL;

  ret->comp = c;

  ret->num_alloc = MIN_NODES;

  ret->num = 0;

  ret->sorted = 0;

  return (ret);

err:

  free(ret);

  return (NULL);

}

int

sk_insert(_STACK *st, void *data, int loc)

{

  char **s;

  if (st == NULL)

    return 0;

  if (st->num_alloc <= st->num + 1) {

    s = reallocarray(st->data, st->num_alloc, 2 * sizeof(char *));

    if (s == NULL)

      return (0);

    st->data = s;

    st->num_alloc *= 2;

  }

  if ((loc >= (int)st->num) || (loc < 0))

    st->data[st->num] = data;

  else {

    memmove(&(st->data[loc + 1]), &(st->data[loc]),

        sizeof(char *)*(st->num - loc));

    st->data[loc] = data;

  }

  st->num++;

  st->sorted = 0;

  return (st->num);

}

void *

sk_delete_ptr(_STACK *st, void *p)

{

  int i;

  for (i = 0; i < st->num; i++)

    if (st->data[i] == p)

      return (sk_delete(st, i));

  return (NULL);

}

void *

sk_delete(_STACK *st, int loc)

{

  char *ret;

  if (!st || (loc < 0) || (loc >= st->num))

    return NULL;

  ret = st->data[loc];

  if (loc != st->num - 1) {

    memmove(&(st->data[loc]), &(st->data[loc + 1]),

        sizeof(char *)*(st->num - 1 - loc));

  }

  st->num--;

  return (ret);

}

static int

internal_find(_STACK *st, void *data, int ret_val_options)

{

  const void * const *r;

  int i;

  if (st == NULL)

    return -1;

  if (st->comp == NULL) {

    for (i = 0; i < st->num; i++)

      if (st->data[i] == data)

        return (i);

    return (-1);

  }

  sk_sort(st);

  if (data == NULL)

    return (-1);

  r = OBJ_bsearch_ex_(&data, st->data, st->num, sizeof(void *), st->comp,

      ret_val_options);

  if (r == NULL)

    return (-1);

  return (int)((char **)r - st->data);

}

int

sk_find(_STACK *st, void *data)

{

  return internal_find(st, data, OBJ_BSEARCH_FIRST_VALUE_ON_MATCH);

}

int

sk_find_ex(_STACK *st, void *data)

{

  return internal_find(st, data, OBJ_BSEARCH_VALUE_ON_NOMATCH);

}

int

sk_push(_STACK *st, void *data)

{

  return (sk_insert(st, data, st->num));

}

int

sk_unshift(_STACK *st, void *data)

{

  return (sk_insert(st, data, 0));

}

void *

sk_shift(_STACK *st)

{

  if (st == NULL)

    return (NULL);

  if (st->num <= 0)

    return (NULL);

  return (sk_delete(st, 0));

}

void *

sk_pop(_STACK *st)

{

  if (st == NULL)

    return (NULL);

  if (st->num <= 0)

    return (NULL);

  return (sk_delete(st, st->num - 1));

}

void

sk_zero(_STACK *st)

{

  if (st == NULL)

    return;

  if (st->num <= 0)

    return;

  memset(st->data, 0, sizeof(st->data)*st->num);

  st->num = 0;

}

void

sk_pop_free(_STACK *st, void (*func)(void *))

{

  int i;

  if (st == NULL)

    return;

  for (i = 0; i < st->num; i++)

    if (st->data[i] != NULL)

      func(st->data[i]);

  sk_free(st);

}

void

sk_free(_STACK *st)

{

  if (st == NULL)

    return;

  free(st->data);

  free(st);

}

int

sk_num(const _STACK *st)

{

  if (st == NULL)

    return -1;

  return st->num;

}

void *

sk_value(const _STACK *st, int i)

{

  if (!st || (i < 0) || (i >= st->num))

    return NULL;

  return st->data[i];

}

void *

sk_set(_STACK *st, int i, void *value)

{

  if (!st || (i < 0) || (i >= st->num))

    return NULL;

  st->sorted = 0;

  return (st->data[i] = value);

}

void

sk_sort(_STACK *st)

{

  if (st && !st->sorted) {

    int (*comp_func)(const void *, const void *);

    /* same comment as in sk_find ... previously st->comp was declared

     * as a (void*,void*) callback type, but this made the population

     * of the callback pointer illogical - our callbacks compare

     * type** with type**, so we leave the casting until absolutely

     * necessary (ie. "now"). */

    comp_func = (int (*)(const void *, const void *))(st->comp);

    qsort(st->data, st->num, sizeof(char *), comp_func);

    st->sorted = 1;

  }

}

int

sk_is_sorted(const _STACK *st)

{

  if (!st)

    return 1;

  return st->sorted;

}