1  /* Test of opening a file descriptor.
       2     Copyright (C) 2007-2021 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 Bruno Haible <bruno@clisp.org>, 2007.  */
      18  
      19  /* Make test_open always inline if we're using Fortify, which defines
      20     __always_inline to do that.  Do nothing otherwise.  This works
      21     around a glibc bug whereby 'open' cannot be used as a function
      22     pointer when _FORTIFY_SOURCE is positive.  */
      23  
      24  #if __GLIBC__ && defined __always_inline
      25  # define ALWAYS_INLINE __always_inline
      26  #else
      27  # define ALWAYS_INLINE
      28  #endif
      29  
      30  /* This file is designed to test both open(n,buf[,mode]) and
      31     openat(AT_FDCWD,n,buf[,mode]).  FUNC is the function to test.
      32     Assumes that BASE and ASSERT are already defined, and that
      33     appropriate headers are already included.  If PRINT, warn before
      34     skipping symlink tests with status 77.  */
      35  
      36  static ALWAYS_INLINE int
      37  test_open (int (*func) (char const *, int, ...), bool print)
      38  {
      39    int fd;
      40  
      41    /* Remove anything from prior partial run.  */
      42    unlink (BASE "file");
      43    unlink (BASE "e.exe");
      44    unlink (BASE "link");
      45  
      46    /* Cannot create directory.  */
      47    errno = 0;
      48    ASSERT (func ("nonexist.ent/", O_CREAT | O_RDONLY, 0600) == -1);
      49    ASSERT (errno == ENOTDIR || errno == EISDIR || errno == ENOENT
      50            || errno == EINVAL);
      51  
      52    /* Create a regular file.  */
      53    fd = func (BASE "file", O_CREAT | O_RDONLY, 0600);
      54    ASSERT (0 <= fd);
      55    ASSERT (close (fd) == 0);
      56  
      57    /* Create an executable regular file.  */
      58    fd = func (BASE "e.exe", O_CREAT | O_RDONLY, 0700);
      59    ASSERT (0 <= fd);
      60    ASSERT (close (fd) == 0);
      61  
      62    /* Trailing slash handling.  */
      63    errno = 0;
      64    ASSERT (func (BASE "file/", O_RDONLY) == -1);
      65    ASSERT (errno == ENOTDIR || errno == EISDIR || errno == EINVAL);
      66  
      67    /* Directories cannot be opened for writing.  */
      68    errno = 0;
      69    ASSERT (func (".", O_WRONLY) == -1);
      70    ASSERT (errno == EISDIR || errno == EACCES);
      71  
      72    /* /dev/null must exist, and be writable.  */
      73    fd = func ("/dev/null", O_RDONLY);
      74    ASSERT (0 <= fd);
      75    {
      76      char c;
      77      ASSERT (read (fd, &c, 1) == 0);
      78    }
      79    ASSERT (close (fd) == 0);
      80    fd = func ("/dev/null", O_WRONLY);
      81    ASSERT (0 <= fd);
      82    ASSERT (write (fd, "c", 1) == 1);
      83    ASSERT (close (fd) == 0);
      84  
      85    /* Although O_NONBLOCK on regular files can be ignored, it must not
      86       cause a failure.  */
      87    fd = func (BASE "file", O_NONBLOCK | O_RDONLY);
      88    ASSERT (0 <= fd);
      89    ASSERT (close (fd) == 0);
      90  
      91    /* O_CLOEXEC must be honoured.  */
      92    if (O_CLOEXEC)
      93      {
      94        /* Since the O_CLOEXEC handling goes through a special code path at its
      95           first invocation, test it twice.  */
      96        int i;
      97  
      98        for (i = 0; i < 2; i++)
      99          {
     100            int flags;
     101  
     102            fd = func (BASE "file", O_CLOEXEC | O_RDONLY);
     103            ASSERT (0 <= fd);
     104            flags = fcntl (fd, F_GETFD);
     105            ASSERT (flags >= 0);
     106            ASSERT ((flags & FD_CLOEXEC) != 0);
     107            ASSERT (close (fd) == 0);
     108          }
     109      }
     110  
     111    /* Symlink handling, where supported.  */
     112    if (symlink (BASE "file", BASE "link") != 0)
     113      {
     114        ASSERT (unlink (BASE "file") == 0);
     115        if (print)
     116          fputs ("skipping test: symlinks not supported on this file system\n",
     117                 stderr);
     118        return 77;
     119      }
     120    errno = 0;
     121    ASSERT (func (BASE "link/", O_RDONLY) == -1);
     122    ASSERT (errno == ENOTDIR);
     123    fd = func (BASE "link", O_RDONLY);
     124    ASSERT (0 <= fd);
     125    ASSERT (close (fd) == 0);
     126  
     127    /* Cleanup.  */
     128    ASSERT (unlink (BASE "file") == 0);
     129    ASSERT (unlink (BASE "e.exe") == 0);
     130    ASSERT (unlink (BASE "link") == 0);
     131  
     132    return 0;
     133  }