64 lines
1.8 KiB
C
64 lines
1.8 KiB
C
/* $Id: compat_mkstemps.c,v 1.1 2021/09/19 15:05:39 schwarze Exp $ */
|
|
/*
|
|
* Copyright (c) 2015, 2021 Ingo Schwarze <schwarze@openbsd.org>
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*
|
|
* Parts of the algorithm of this function are inspired by OpenBSD
|
|
* mkdtemp(3) by Theo de Raadt and Todd Miller, but the code differs.
|
|
*/
|
|
#include "config.h"
|
|
|
|
#include <sys/stat.h>
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <limits.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
int
|
|
mkstemps(char *path, int suffixlen)
|
|
{
|
|
char *start, *end, *cp;
|
|
int fd, tries;
|
|
char backup;
|
|
|
|
end = strchr(path, '\0');
|
|
if (suffixlen < 0 || suffixlen > end - path - 6) {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
end -= suffixlen;
|
|
for (start = end; start > path; start--)
|
|
if (start[-1] != 'X')
|
|
break;
|
|
|
|
backup = *end;
|
|
for (tries = INT_MAX; tries; tries--) {
|
|
*end = '\0';
|
|
cp = mktemp(path);
|
|
*end = backup;
|
|
if (cp == NULL)
|
|
return -1;
|
|
fd = open(path, O_CREAT | O_EXCL | O_RDWR, S_IRUSR | S_IWUSR);
|
|
if (fd != -1)
|
|
return fd;
|
|
for (cp = start; cp < end; cp++)
|
|
*cp = 'X';
|
|
if (errno != EEXIST)
|
|
return -1;
|
|
}
|
|
errno = EEXIST;
|
|
return -1;
|
|
}
|