citus/vendor/safestringlib/safeclib/stpcpy_s.c

235 lines
7.3 KiB
C

/*------------------------------------------------------------------
* stpcpy_s.c
*
* August 2014, D Wheeler
*
* Copyright (c) 2014 by Intel Corp
* All rights reserved.
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*------------------------------------------------------------------
*/
#include "safeclib_private.h"
#include "safe_str_constraint.h"
#include "safe_str_lib.h"
/**
* NAME
* stpcpy_s
*
* SYNOPSIS
* #include "safe_str_lib.h"
* char *
* stpcpy_s(char *dest, rsize_t dmax, const char *src, errno_t *err);
*
* DESCRIPTION
* The stpcpy_s function copies the string pointed to by src
* (including the terminating null character) into the array
* pointed to by dest. All elements following the terminating
* null character (if any) written by stpcpy_s in the array
* of dmax characters pointed to by dest are nulled when
* strcpy_s returns. The function returns a pointer to the
* end of the string in dest - that is to the null terminator
* of dest - upon return. If an error occurs, NULL is returned
* and err is set to the error encountered.
*
* SPECIFIED IN
* ISO/IEC TR 24731, Programming languages, environments
* and system software interfaces, Extensions to the C Library,
* Part I: Bounds-checking interfaces
*
* INPUT PARAMETERS
* dest pointer to string that will be replaced by src.
*
* dmax restricted maximum length of dest
*
* src pointer to the string that will be copied
* to dest
*
* err the error code upon error, or EOK if successful
*
* OUTPUT PARAMETERS
* dest updated
* err updated as follows:
* EOK successful operation, the characters in src were
* copied into dest and the result is null terminated.
* ESNULLP NULL pointer
* ESZEROL zero length
* ESLEMAX length exceeds max limit
* ESOVRLP strings overlap
* ESNOSPC not enough space to copy src
*
* RUNTIME CONSTRAINTS
* Neither dest nor src shall be a null pointer.
* dmax shall not be greater than RSIZE_MAX_STR.
* dmax shall not equal zero.
* dmax shall be greater than strnlen_s(src, dmax).
* Copying shall not take place between objects that overlap.
* If there is a runtime-constraint violation, then if dest
* is not a null pointer and destmax is greater than zero and
* not greater than RSIZE_MAX_STR, then stpcpy_s nulls dest.
*
* RETURN VALUE
* a char pointer to the terminating null at the end of dest
*
* ALSO SEE
* strcpy_s(), strcat_s(), strncat_s(), strncpy_s()
*
*/
char *
stpcpy_s(char *dest, rsize_t dmax, const char *src, errno_t *err)
{
rsize_t orig_dmax;
char *orig_dest;
const char *overlap_bumper;
if (dest == NULL) {
invoke_safe_str_constraint_handler("stpcpy_s: dest is null",
NULL, ESNULLP);
*err = RCNEGATE(ESNULLP);
return NULL;
}
if (dmax == 0) {
invoke_safe_str_constraint_handler("stpcpy_s: dmax is 0",
NULL, ESZEROL);
*err = RCNEGATE(ESZEROL);
return NULL;
}
if (dmax > RSIZE_MAX_STR) {
invoke_safe_str_constraint_handler("stpcpy_s: dmax exceeds max",
NULL, ESLEMAX);
*err = RCNEGATE(ESLEMAX);
return NULL;
}
if (src == NULL) {
#ifdef SAFECLIB_STR_NULL_SLACK
/* null string to clear data */
while (dmax) { *dest = '\0'; dmax--; dest++; }
#else
*dest = '\0';
#endif
invoke_safe_str_constraint_handler("stpcpy_s: src is null",
NULL, ESNULLP);
*err = RCNEGATE(ESNULLP);
return NULL;
}
/* hold base of dest in case src was not copied */
orig_dmax = dmax;
orig_dest = dest;
if (dest == src) {
/* look for the terminating null character, or return err if not found in dmax bytes */
while (dmax > 0) {
if (*dest == '\0') {
#ifdef SAFECLIB_STR_NULL_SLACK
/* null slack to clear any data */
while (dmax) { *dest = '\0'; dmax--; dest++; }
#endif
*err = RCNEGATE(EOK);
return dest;
}
dmax--;
dest++;
}
/* null terminator not found in src before end of dmax */
handle_error(orig_dest, orig_dmax, "stpcpy_s: not enough space for src",
ESNOSPC);
*err = RCNEGATE(ESNOSPC);
return NULL;
}
if (dest < src) {
overlap_bumper = src;
/* Check that the dest buffer does not overlap src buffer */
while (dmax > 0) {
if (dest == overlap_bumper) {
handle_error(orig_dest, orig_dmax, "stpcpy_s: "
"overlapping objects",
ESOVRLP);
*err = RCNEGATE(ESOVRLP);
return NULL;
}
*dest = *src;
if (*dest == '\0') {
#ifdef SAFECLIB_STR_NULL_SLACK
/* null slack to clear any data */
while (dmax) { *dest = '\0'; dmax--; dest++; }
#endif
*err = RCNEGATE(EOK);
return dest;
}
dmax--;
dest++;
src++;
}
} else {
overlap_bumper = dest;
while (dmax > 0) {
/* check that the src buffer does not run into the dest buffer - inifinite loop */
if (src == overlap_bumper) {
/* NOTE (dmw) this condition guarantees that SRC has already been damaged! */
handle_error(orig_dest, orig_dmax, "stpcpy_s: overlapping objects",
ESOVRLP);
*err = RCNEGATE(ESOVRLP);
return NULL;
}
*dest = *src;
if (*dest == '\0') {
#ifdef SAFECLIB_STR_NULL_SLACK
/* null slack to clear any data */
while (dmax) { *dest = '\0'; dmax--; dest++; }
#endif
*err = RCNEGATE(EOK);
return dest;
}
dmax--;
dest++;
src++;
}
}
/*
* Ran out of space in dest, and did not find the null terminator in src
*/
handle_error(orig_dest, orig_dmax, "stpcpy_s: not "
"enough space for src",
ESNOSPC);
*err = RCNEGATE(ESNOSPC);
return NULL;
}
EXPORT_SYMBOL(stpcpy_s)