/* alloc - Convenience routines for safely allocating memory

 * Copyright (C) 2007-2009  Josh Coalson

 * Copyright (C) 2011-2016  Xiph.Org Foundation

 *

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

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * - Redistributions of source code must retain the above copyright

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

 *

 * - 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.

 *

 * - Neither the name of the Xiph.org Foundation nor the names of its

 * contributors may be used to endorse or promote products derived from

 * this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * ``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 FOUNDATION 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.

 */

#ifndef FLAC__SHARE__ALLOC_H

#define FLAC__SHARE__ALLOC_H

#ifdef HAVE_CONFIG_H

#  include <config.h>

#endif

/* WATCHOUT: for c++ you may have to #define __STDC_LIMIT_MACROS 1 real early

 * before #including this file,  otherwise SIZE_MAX might not be defined

 */

#include <limits.h> /* for SIZE_MAX */

#if HAVE_STDINT_H

#include <stdint.h> /* for SIZE_MAX in case limits.h didn't get it */

#endif

#include <stdlib.h> /* for size_t, malloc(), etc */

#include "share/compat.h"

#ifndef SIZE_MAX

# ifndef SIZE_T_MAX

#  ifdef _MSC_VER

#   ifdef _WIN64

#    define SIZE_T_MAX FLAC__U64L(0xffffffffffffffff)

#   else

#    define SIZE_T_MAX 0xffffffff

#   endif

#  else

#   error

#  endif

# endif

# define SIZE_MAX SIZE_T_MAX

#endif

/* avoid malloc()ing 0 bytes, see:

 * https://www.securecoding.cert.org/confluence/display/seccode/MEM04-A.+Do+not+make+assumptions+about+the+result+of+allocating+0+bytes?focusedCommentId=5407003

*/

static inline void *safe_malloc_(size_t size)

{

	/* malloc(0) is undefined; FLAC src convention is to always allocate */

	if(!size)

		size++;

	return malloc(size);

}

static inline void *safe_calloc_(size_t nmemb, size_t size)

{

	if(!nmemb || !size)

		return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */

	return calloc(nmemb, size);

}

/*@@@@ there's probably a better way to prevent overflows when allocating untrusted sums but this works for now */

static inline void *safe_malloc_add_2op_(size_t size1, size_t size2)

{

	size2 += size1;

	if(size2 < size1)

		return 0;

	return safe_malloc_(size2);

}

static inline void *safe_malloc_add_3op_(size_t size1, size_t size2, size_t size3)

{

	size2 += size1;

	if(size2 < size1)

		return 0;

	size3 += size2;

	if(size3 < size2)

		return 0;

	return safe_malloc_(size3);

}

static inline void *safe_malloc_add_4op_(size_t size1, size_t size2, size_t size3, size_t size4)

{

	size2 += size1;

	if(size2 < size1)

		return 0;

	size3 += size2;

	if(size3 < size2)

		return 0;

	size4 += size3;

	if(size4 < size3)

		return 0;

	return safe_malloc_(size4);

}

void *safe_malloc_mul_2op_(size_t size1, size_t size2) ;

static inline void *safe_malloc_mul_3op_(size_t size1, size_t size2, size_t size3)

{

	if(!size1 || !size2 || !size3)

		return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */

	if(size1 > SIZE_MAX / size2)

		return 0;

	size1 *= size2;

	if(size1 > SIZE_MAX / size3)

		return 0;

	return malloc(size1*size3);

}

/* size1*size2 + size3 */

static inline void *safe_malloc_mul2add_(size_t size1, size_t size2, size_t size3)

{

	if(!size1 || !size2)

		return safe_malloc_(size3);

	if(size1 > SIZE_MAX / size2)

		return 0;

	return safe_malloc_add_2op_(size1*size2, size3);

}

/* size1 * (size2 + size3) */

static inline void *safe_malloc_muladd2_(size_t size1, size_t size2, size_t size3)

{

	if(!size1 || (!size2 && !size3))

		return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */

	size2 += size3;

	if(size2 < size3)

		return 0;

	if(size1 > SIZE_MAX / size2)

		return 0;

	return malloc(size1*size2);

}

static inline void *safe_realloc_(void *ptr, size_t size)

{

	void *oldptr = ptr;

	void *newptr = realloc(ptr, size);

	if(size > 0 && newptr == 0)

		free(oldptr);

	return newptr;

}

static inline void *safe_realloc_add_2op_(void *ptr, size_t size1, size_t size2)

{

	size2 += size1;

	if(size2 < size1) {

		free(ptr);

		return 0;

	}

	return realloc(ptr, size2);

}

static inline void *safe_realloc_add_3op_(void *ptr, size_t size1, size_t size2, size_t size3)

{

	size2 += size1;

	if(size2 < size1)

		return 0;

	size3 += size2;

	if(size3 < size2)

		return 0;

	return realloc(ptr, size3);

}

static inline void *safe_realloc_add_4op_(void *ptr, size_t size1, size_t size2, size_t size3, size_t size4)

{

	size2 += size1;

	if(size2 < size1)

		return 0;

	size3 += size2;

	if(size3 < size2)

		return 0;

	size4 += size3;

	if(size4 < size3)

		return 0;

	return realloc(ptr, size4);

}

static inline void *safe_realloc_mul_2op_(void *ptr, size_t size1, size_t size2)

{

	if(!size1 || !size2)

		return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */

	if(size1 > SIZE_MAX / size2)

		return 0;

	return safe_realloc_(ptr, size1*size2);

}

/* size1 * (size2 + size3) */

static inline void *safe_realloc_muladd2_(void *ptr, size_t size1, size_t size2, size_t size3)

{

	if(!size1 || (!size2 && !size3))

		return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */

	size2 += size3;

	if(size2 < size3)

		return 0;

	return safe_realloc_mul_2op_(ptr, size1, size2);

}

#endif