1  /* Test that openat works.
       2     Copyright (C) 2009-2023 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 <stdio.h>
      29  #include <unistd.h>
      30  
      31  #include "macros.h"
      32  
      33  #define BASE "test-openat.t"
      34  
      35  #include "test-open.h"
      36  
      37  static int dfd = AT_FDCWD;
      38  
      39  /* Wrapper around openat to test open behavior.  */
      40  static int
      41  do_open (char const *name, int flags, ...)
      42  {
      43    if (flags & O_CREAT)
      44      {
      45        mode_t mode = 0;
      46        va_list arg;
      47        va_start (arg, flags);
      48  
      49        /* We have to use PROMOTED_MODE_T instead of mode_t, otherwise GCC 4
      50           creates crashing code when 'mode_t' is smaller than 'int'.  */
      51        mode = va_arg (arg, PROMOTED_MODE_T);
      52  
      53        va_end (arg);
      54        return openat (dfd, name, flags, mode);
      55      }
      56    return openat (dfd, name, flags);
      57  }
      58  
      59  int
      60  main (_GL_UNUSED int argc, char *argv[])
      61  {
      62    int result;
      63  
      64    /* Test behaviour for invalid file descriptors.  */
      65    {
      66      errno = 0;
      67      ASSERT (openat (-1, "foo", O_RDONLY) == -1);
      68      ASSERT (errno == EBADF);
      69    }
      70    {
      71      close (99);
      72      errno = 0;
      73      ASSERT (openat (99, "foo", O_RDONLY) == -1);
      74      ASSERT (errno == EBADF);
      75    }
      76  
      77    /* Basic checks.  */
      78    result = test_open (do_open, false);
      79    dfd = open (".", O_RDONLY);
      80    ASSERT (0 <= dfd);
      81    ASSERT (test_open (do_open, false) == result);
      82    ASSERT (close (dfd) == 0);
      83  
      84    /* Check that even when *-safer modules are in use, plain openat can
      85       land in fd 0.  Do this test last, since it is destructive to
      86       stdin.  */
      87    ASSERT (close (STDIN_FILENO) == 0);
      88    ASSERT (openat (AT_FDCWD, ".", O_RDONLY) == STDIN_FILENO);
      89    {
      90      dfd = open (".", O_RDONLY);
      91      ASSERT (STDIN_FILENO < dfd);
      92      ASSERT (chdir ("..") == 0);
      93      ASSERT (close (STDIN_FILENO) == 0);
      94      ASSERT (openat (dfd, ".", O_RDONLY) == STDIN_FILENO);
      95      ASSERT (close (dfd) == 0);
      96    }
      97    return result;
      98  }