/* Test that directory streams leave standard fds alone.

   Copyright (C) 2009-2017 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 <http://www.gnu.org/licenses/>.  */

/* Written by Eric Blake <ebb9@byu.net>, 2009.  */

#include <config.h>

#include "dirent--.h"

#include <errno.h>

#include <fcntl.h>

#include <stdio.h>

#include <unistd.h>

#include "unistd-safer.h"

/* This test intentionally closes stderr.  So, we arrange to have fd 10

   (outside the range of interesting fd's during the test) set up to

   duplicate the original stderr.  */

#define BACKUP_STDERR_FILENO 10

#define ASSERT_STREAM myerr

#include "macros.h"

static FILE *myerr;

int

main (void)

{

  int i;

  DIR *dp;

  /* The dirent-safer module works without the use of fdopendir (which

     would also pull in fchdir and openat); but if those modules were

     also used, we ensure that they are safe.  In particular, the

     gnulib version of fdopendir is unable to guarantee that

     dirfd(fdopendir(fd))==fd, but we can at least guarantee that if

     they are not equal, the fd returned by dirfd is safe.  */

#if HAVE_FDOPENDIR || GNULIB_TEST_FDOPENDIR

  int dfd;

#endif

  /* We close fd 2 later, so save it in fd 10.  */

  if (dup2 (STDERR_FILENO, BACKUP_STDERR_FILENO) != BACKUP_STDERR_FILENO

      || (myerr = fdopen (BACKUP_STDERR_FILENO, "w")) == NULL)

    return 2;

#if HAVE_FDOPENDIR || GNULIB_TEST_FDOPENDIR

  dfd = open (".", O_RDONLY);

  ASSERT (STDERR_FILENO < dfd);

#endif

  /* Four iterations, with progressively more standard descriptors

     closed.  */

  for (i = -1; i <= STDERR_FILENO; i++)

    {

      if (0 <= i)

        ASSERT (close (i) == 0);

      dp = opendir (".");

      ASSERT (dp);

      ASSERT (dirfd (dp) == -1 || STDERR_FILENO < dirfd (dp));

      ASSERT (closedir (dp) == 0);

#if HAVE_FDOPENDIR || GNULIB_TEST_FDOPENDIR

      {

        int fd = dup_safer (dfd);

        ASSERT (STDERR_FILENO < fd);

        dp = fdopendir (fd);

        ASSERT (dp);

        ASSERT (dirfd (dp) == -1 || STDERR_FILENO < dirfd (dp));

        ASSERT (closedir (dp) == 0);

        errno = 0;

        ASSERT (close (fd) == -1);

        ASSERT (errno == EBADF);

      }

#endif

    }

#if HAVE_FDOPENDIR || GNULIB_TEST_FDOPENDIR

  ASSERT (close (dfd) == 0);

#endif

  return 0;

}