text: /* Test that openat_safer leave standard fds alone.
     Copyright (C) 2009-2012 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 "fcntl--.h"
  
  #include <errno.h>
  #include <stdio.h>
  #include <sys/stat.h>
  #include <unistd.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;
  
  #define witness "test-openat-safer.txt"
  
  int
  main (void)
  {
    int i;
    int j;
    int dfd;
    int fd;
    char buf[2];
  
    /* 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;
  
    /* Create handle for future use.  */
    dfd = openat (AT_FDCWD, ".", O_RDONLY);
    ASSERT (STDERR_FILENO < dfd);
  
    /* Create file for later checks.  */
    remove (witness);
    fd = openat (dfd, witness, O_WRONLY | O_CREAT | O_EXCL, 0600);
    ASSERT (STDERR_FILENO < fd);
    ASSERT (write (fd, "hi", 2) == 2);
    ASSERT (close (fd) == 0);
  
    /* Four iterations, with progressively more standard descriptors
       closed.  */
    for (i = -1; i <= STDERR_FILENO; i++)
      {
        ASSERT (fchdir (dfd) == 0);
        if (0 <= i)
          ASSERT (close (i) == 0);
  
        /* Execute once in ".", once in "..".  */
        for (j = 0; j <= 1; j++)
          {
            if (j)
              ASSERT (chdir ("..") == 0);
  
            /* Check for error detection.  */
            errno = 0;
            ASSERT (openat (AT_FDCWD, "", O_RDONLY) == -1);
            ASSERT (errno == ENOENT);
            errno = 0;
            ASSERT (openat (dfd, "", O_RDONLY) == -1);
            ASSERT (errno == ENOENT);
            errno = 0;
            ASSERT (openat (-1, ".", O_RDONLY) == -1);
            ASSERT (errno == EBADF);
  
            /* Check for trailing slash and /dev/null handling.  */
            errno = 0;
            ASSERT (openat (dfd, "nonexist.ent/", O_CREAT | O_RDONLY,
                            S_IRUSR | S_IWUSR) == -1);
            ASSERT (errno == ENOTDIR || errno == EISDIR || errno == ENOENT
                    || errno == EINVAL);
            errno = 0;
            ASSERT (openat (dfd, witness "/", O_RDONLY) == -1);
            ASSERT (errno == ENOTDIR || errno == EISDIR || errno == EINVAL);
            /* Using a bad directory is okay for absolute paths.  */
            fd = openat (-1, "/dev/null", O_WRONLY);
            ASSERT (STDERR_FILENO < fd);
            /* Using a non-directory is wrong for relative paths.  */
            errno = 0;
            ASSERT (openat (fd, ".", O_RDONLY) == -1);
            ASSERT (errno == EBADF || errno == ENOTDIR);
            ASSERT (close (fd) == 0);
  
            /* Check for our witness file.  */
            fd = openat (dfd, witness, O_RDONLY | O_NOFOLLOW);
            ASSERT (STDERR_FILENO < fd);
            ASSERT (read (fd, buf, 2) == 2);
            ASSERT (buf[0] == 'h' && buf[1] == 'i');
            ASSERT (close (fd) == 0);
          }
      }
    ASSERT (fchdir (dfd) == 0);
    ASSERT (unlink (witness) == 0);
    ASSERT (close (dfd) == 0);
  
    return 0;
  }
  