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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
/***
*memcpy_s.c - contains memcpy_s routine
*
*
*Purpose:
* memcpy_s() copies a source memory buffer to a destination buffer.
* Overlapping buffers are not treated specially, so propagation may occur.
*
*Revision History:
* 10-07-03 AC Module created.
* 03-10-04 AC Return ERANGE when buffer is too small
* 01-14-05 AC Prefast (espx) fixes
*
*******************************************************************************/
#include <string.h>
#include <errno.h>
#include <assert.h>
#include "internal_securecrt.h"
#include "mbusafecrt_internal.h"
/***
*memcpy_s - Copy source buffer to destination buffer
*
*Purpose:
* memcpy_s() copies a source memory buffer to a destination memory buffer.
* This routine does NOT recognize overlapping buffers, and thus can lead
* to propagation.
*
* For cases where propagation must be avoided, memmove_s() must be used.
*
*Entry:
* void *dst = pointer to destination buffer
* size_t sizeInBytes = size in bytes of the destination buffer
* const void *src = pointer to source buffer
* size_t count = number of bytes to copy
*
*Exit:
* Returns 0 if everything is ok, else return the error code.
*
*Exceptions:
* Input parameters are validated. Refer to the validation section of the function.
* On error, the error code is returned and the destination buffer is zeroed.
*
*******************************************************************************/
errno_t __cdecl memcpy_s(
void * dst,
size_t sizeInBytes,
const void * src,
size_t count
)
{
if (count == 0)
{
/* nothing to do */
return 0;
}
/* validation section */
_VALIDATE_RETURN_ERRCODE(dst != NULL, EINVAL);
if (src == NULL || sizeInBytes < count)
{
/* zeroes the destination buffer */
memset(dst, 0, sizeInBytes);
_VALIDATE_RETURN_ERRCODE(src != NULL, EINVAL);
_VALIDATE_RETURN_ERRCODE(sizeInBytes >= count, ERANGE);
/* useless, but prefast is confused */
return EINVAL;
}
UINT_PTR x = (UINT_PTR)dst, y = (UINT_PTR)src;
assert((x + count <= y) || (y + count <= x));
memcpy(dst, src, count);
return 0;
}
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