/* crypto/stack/stack.c */

/* 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.]

 */

/* Code for stacks

 * Author - Eric Young v 1.0

 * 1.2 eay 12-Mar-97 -	Modified sk_find so that it _DOES_ return the

 *			lowest index for the searched item.

 *

 * 1.1 eay - Take from netdb and added to SSLeay

 *

 * 1.0 eay - First version 29/07/92

 */

#include <stdio.h>

#include "cryptlib.h"

#include <openssl/stack.h>

#include <openssl/objects.h>

#undef MIN_NODES

#define MIN_NODES	4

const char STACK_version[]="Stack" OPENSSL_VERSION_PTEXT;

#include <errno.h>

EXPORT_C  int (*sk_set_cmp_func(STACK *sk, int (*c)(const char * const *,const char * const *)))

		(const char * const *, const char * const *)

	{

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

	if (sk->comp != c)

		sk->sorted=0;

	sk->comp=c;

	return old;

	}

EXPORT_C STACK *sk_dup(STACK *sk)

	{

	STACK *ret;

	char **s;

	if ((ret=sk_new(sk->comp)) == NULL) goto err;

	s=(char **)OPENSSL_realloc((char *)ret->data,

		(unsigned int)sizeof(char *)*sk->num_alloc);

	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);

	}

EXPORT_C STACK *sk_new_null(void)

	{

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

	}

EXPORT_C STACK *sk_new(int (*c)(const char * const *, const char * const *))

	{

	STACK *ret;

	int i;

	if ((ret=(STACK *)OPENSSL_malloc(sizeof(STACK))) == NULL)

		goto err;

	if ((ret->data=(char **)OPENSSL_malloc(sizeof(char *)*MIN_NODES)) == 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:

	if(ret)

		OPENSSL_free(ret);

	return(NULL);

	}

EXPORT_C int sk_insert(STACK *st, char *data, int loc)

	{

	char **s;

	if(st == NULL) return 0;

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

		{

		s=(char **)OPENSSL_realloc((char *)st->data,

			(unsigned int)sizeof(char *)*st->num_alloc*2);

		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

		{

		int i;

		char **f,**t;

		f=(char **)st->data;

		t=(char **)&(st->data[1]);

		for (i=st->num; i>=loc; i--)

			t[i]=f[i];

#ifdef undef /* no memmove on sunos :-( */

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

			(char *)&(st->data[loc]),

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

#endif

		st->data[loc]=data;

		}

	st->num++;

	st->sorted=0;

	return(st->num);

	}

EXPORT_C char *sk_delete_ptr(STACK *st, char *p)

	{

	int i;

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

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

			return(sk_delete(st,i));

	return(NULL);

	}

EXPORT_C char *sk_delete(STACK *st, int loc)

	{

	char *ret;

	int i,j;

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

	ret=st->data[loc];

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

		{

		j=st->num-1;

		for (i=loc; i<j; i++)

			st->data[i]=st->data[i+1];

		/* In theory memcpy is not safe for this

		 * memcpy( &(st->data[loc]),

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

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

		 */

		}

	st->num--;

	return(ret);

	}

static int internal_find(STACK *st, char *data, int ret_val_options)

	{

	char **r;

	int i;

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

	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);

	/* This (and the "qsort" below) are the two places in OpenSSL

	 * where we need to convert from our standard (type **,type **)

	 * compare callback type to the (void *,void *) type required by

	 * bsearch. However, the "data" it is being called(back) with are

	 * not (type *) pointers, but the *pointers* to (type *) pointers,

	 * so we get our extra level of pointer dereferencing that way. */

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

	r=(char **)OBJ_bsearch_ex((char *)&data,(char *)st->data,

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

	if (r == NULL) return(-1);

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

	}

EXPORT_C int sk_find(STACK *st, char *data)

	{

	return internal_find(st, data, OBJ_BSEARCH_FIRST_VALUE_ON_MATCH);

	}

EXPORT_C int sk_find_ex(STACK *st, char *data)

	{

	return internal_find(st, data, OBJ_BSEARCH_VALUE_ON_NOMATCH);

	}

EXPORT_C int sk_push(STACK *st, char *data)

	{

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

	}

EXPORT_C int sk_unshift(STACK *st, char *data)

	{

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

	}

EXPORT_C char *sk_shift(STACK *st)

	{

	if (st == NULL) return(NULL);

	if (st->num <= 0) return(NULL);

	return(sk_delete(st,0));

	}

EXPORT_C char *sk_pop(STACK *st)

	{

	if (st == NULL) return(NULL);

	if (st->num <= 0) return(NULL);

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

	}

EXPORT_C void sk_zero(STACK *st)

	{

	if (st == NULL) return;

	if (st->num <= 0) return;

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

	st->num=0;

	}

EXPORT_C 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);

	}

EXPORT_C void sk_free(STACK *st)

	{

	if (st == NULL) return;

	if (st->data != NULL) OPENSSL_free(st->data);

	OPENSSL_free(st);

	}

EXPORT_C int sk_num(const STACK *st)

{

	if(st == NULL) return -1;

	return st->num;

}

EXPORT_C char *sk_value(const STACK *st, int i)

{

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

	return st->data[i];

}

EXPORT_C char *sk_set(STACK *st, int i, char *value)

{

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

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

}

EXPORT_C 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;

		}

	}

EXPORT_C int sk_is_sorted(const STACK *st)

	{

	if (!st)

		return 1;

	return st->sorted;

	}