1  /* Test that openat works.
       2     Copyright (C) 2009-2022 Free Software Foundation, Inc.
       3  
       4     This program is free software: you can redistribute it and/or modify
       5     it under the terms of the GNU General Public License as published by
       6     the Free Software Foundation, either version 3 of the License, or
       7     (at your option) any later version.
       8  
       9     This program is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      12     GNU General Public License for more details.
      13  
      14     You should have received a copy of the GNU General Public License
      15     along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
      16  
      17  /* Written by Eric Blake <ebb9@byu.net>, 2009.  */
      18  
      19  #include <config.h>
      20  
      21  #include <fcntl.h>
      22  
      23  #include "signature.h"
      24  SIGNATURE_CHECK (openat, int, (int, char const *, int, ...));
      25  
      26  #include <errno.h>
      27  #include <stdarg.h>
      28  #include <stdbool.h>
      29  #include <stdio.h>
      30  #include <unistd.h>
      31  
      32  #include "macros.h"
      33  
      34  #define BASE "test-openat.t"
      35  
      36  #include "test-open.h"
      37  
      38  static int dfd = AT_FDCWD;
      39  
      40  /* Wrapper around openat to test open behavior.  */
      41  static int
      42  do_open (char const *name, int flags, ...)
      43  {
      44    if (flags & O_CREAT)
      45      {
      46        mode_t mode = 0;
      47        va_list arg;
      48        va_start (arg, flags);
      49  
      50        /* We have to use PROMOTED_MODE_T instead of mode_t, otherwise GCC 4
      51           creates crashing code when 'mode_t' is smaller than 'int'.  */
      52        mode = va_arg (arg, PROMOTED_MODE_T);
      53  
      54        va_end (arg);
      55        return openat (dfd, name, flags, mode);
      56      }
      57    return openat (dfd, name, flags);
      58  }
      59  
      60  int
      61  main (_GL_UNUSED int argc, char *argv[])
      62  {
      63    int result;
      64  
      65    /* Test behaviour for invalid file descriptors.  */
      66    {
      67      errno = 0;
      68      ASSERT (openat (-1, "foo", O_RDONLY) == -1);
      69      ASSERT (errno == EBADF);
      70    }
      71    {
      72      close (99);
      73      errno = 0;
      74      ASSERT (openat (99, "foo", O_RDONLY) == -1);
      75      ASSERT (errno == EBADF);
      76    }
      77  
      78    /* Basic checks.  */
      79    result = test_open (do_open, false);
      80    dfd = open (".", O_RDONLY);
      81    ASSERT (0 <= dfd);
      82    ASSERT (test_open (do_open, false) == result);
      83    ASSERT (close (dfd) == 0);
      84  
      85    /* Check that even when *-safer modules are in use, plain openat can
      86       land in fd 0.  Do this test last, since it is destructive to
      87       stdin.  */
      88    ASSERT (close (STDIN_FILENO) == 0);
      89    ASSERT (openat (AT_FDCWD, ".", O_RDONLY) == STDIN_FILENO);
      90    {
      91      dfd = open (".", O_RDONLY);
      92      ASSERT (STDIN_FILENO < dfd);
      93      ASSERT (chdir ("..") == 0);
      94      ASSERT (close (STDIN_FILENO) == 0);
      95      ASSERT (openat (dfd, ".", O_RDONLY) == STDIN_FILENO);
      96      ASSERT (close (dfd) == 0);
      97    }
      98    return result;
      99  }