gnulib/lib/openat-safer.c

/* Invoke openat, but avoid some glitches.

   Copyright (C) 2005-2006, 2008-2020 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */

/* Written by Paul Eggert for open, ported by Eric Blake for openat.  */

#include <config.h>

#include "fcntl-safer.h"

#include <fcntl.h>
#include <stdarg.h>
#include "unistd-safer.h"

int
openat_safer (int fd, char const *file, int flags, ...)
{
  mode_t mode = 0;

  if (flags & O_CREAT)
    {
      va_list ap;
      va_start (ap, flags);

      /* We have to use PROMOTED_MODE_T instead of mode_t, otherwise GCC 4
         creates crashing code when 'mode_t' is smaller than 'int'.  */
      mode = va_arg (ap, PROMOTED_MODE_T);

      va_end (ap);
    }

  return fd_safer (openat (fd, file, flags, mode));
}