mirror of
https://github.com/troglobit/libite.git
synced 2026-10-01 21:42:28 +07:00
72 lines
2.2 KiB
C
72 lines
2.2 KiB
C
/* A secure tmpfile() replacement.
|
|
*
|
|
* Copyright (c) 2015 Joachim Nilsson <troglobit@gmail.com>
|
|
*
|
|
* Permission to use, copy, modify, and/or 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.
|
|
*/
|
|
|
|
#include <paths.h>
|
|
#include <fcntl.h> /* O_TMPFILE requires -D_GNU_SOURCE */
|
|
#include <stdlib.h> /* mkstemp() */
|
|
#include <stdio.h> /* fdopen() */
|
|
#include <sys/stat.h> /* umask() */
|
|
|
|
#ifndef O_TMPFILE /* Too old GLIBC or kernel */
|
|
#warning O_TMPFILE missing on your system, tempfile() may not work!
|
|
#define O_TMPFILE 020200000 /* Define and let it fail at runtime */
|
|
#endif
|
|
|
|
/**
|
|
* tempfile - A secure tmpfile() replacement
|
|
*
|
|
* This is the secure replacement for tmpfile() that does not exist in
|
|
* GLIBC. The function uses the Linux specific %O_TMPFILE and %O_EXCL
|
|
* for security. When the %FILE is fclose()'ed the file contents is
|
|
* lost. The file is hidden in the %_PATH_TMP directory on the system.
|
|
*
|
|
* This function requires Linux 3.11, or later, due to %O_TMPFILE.
|
|
*
|
|
* Returns:
|
|
* An open %FILE pointer, or %NULL on error.
|
|
*/
|
|
FILE *tempfile(void)
|
|
{
|
|
int fd;
|
|
mode_t oldmask;
|
|
|
|
oldmask = umask(0077);
|
|
fd = open(_PATH_TMP, O_TMPFILE | O_RDWR | O_EXCL | O_CLOEXEC, S_IRUSR | S_IWUSR);
|
|
umask(oldmask);
|
|
if (-1 == fd)
|
|
return NULL;
|
|
|
|
return fdopen(fd, "rw");
|
|
}
|
|
|
|
#ifdef UNITTEST
|
|
int main(void)
|
|
{
|
|
FILE *fp = tempfile(); system("ls -lrt "
|
|
_PATH_TMP " | tail -10"); return fclose(fp);
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* Local Variables:
|
|
* compile-command: "gcc -D_GNU_SOURCE -DUNITTEST -o tempy tempfile.c && ./tempy"
|
|
* version-control: t
|
|
* indent-tabs-mode: t
|
|
* c-file-style: "linux"
|
|
* End:
|
|
*/
|