tests/test-open.h

   1 /* Test of opening a file descriptor.
   2    Copyright (C) 2007-2024 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 /* Tell GCC not to warn about the specific edge cases tested here.  */
  20 #if __GNUC__ >= 13
  21 # pragma GCC diagnostic ignored "-Wanalyzer-fd-leak"
  22 #endif
  23
  24 /* Make test_open always inline if we're using Fortify, which defines
  25    __always_inline to do that.  Do nothing otherwise.  This works
  26    around a glibc bug whereby 'open' cannot be used as a function
  27    pointer when _FORTIFY_SOURCE is positive.  */
  28
  29 #if __GLIBC__ && defined __always_inline
  30 # define ALWAYS_INLINE __always_inline
  31 #else
  32 # define ALWAYS_INLINE
  33 #endif
  34
  35 /* This file is designed to test both open(n,buf[,mode]) and
  36    openat(AT_FDCWD,n,buf[,mode]).  FUNC is the function to test.
  37    Assumes that BASE and ASSERT are already defined, and that
  38    appropriate headers are already included.  If PRINT, warn before
  39    skipping symlink tests with status 77.  */
  40
  41 static ALWAYS_INLINE int
  42 test_open (int (*func) (char const *, int, ...), bool print)
  43 {
  44   int fd;
  45
  46   /* Remove anything from prior partial run.  */
  47   unlink (BASE "file");
  48   unlink (BASE "e.exe");
  49   unlink (BASE "link");
  50
  51   /* Cannot create directory.  */
  52   errno = 0;
  53   ASSERT (func ("nonexist.ent/", O_CREAT | O_RDONLY, 0600) == -1);
  54   ASSERT (errno == ENOTDIR || errno == EISDIR || errno == ENOENT
  55           || errno == EINVAL);
  56
  57   /* Create a regular file.  */
  58   fd = func (BASE "file", O_CREAT | O_RDONLY, 0600);
  59   ASSERT (0 <= fd);
  60   ASSERT (close (fd) == 0);
  61
  62   /* Create an executable regular file.  */
  63   fd = func (BASE "e.exe", O_CREAT | O_RDONLY, 0700);
  64   ASSERT (0 <= fd);
  65   ASSERT (close (fd) == 0);
  66
  67   /* Trailing slash handling.  */
  68   errno = 0;
  69   ASSERT (func (BASE "file/", O_RDONLY) == -1);
  70   ASSERT (errno == ENOTDIR || errno == EISDIR || errno == EINVAL);
  71
  72   /* Directories cannot be opened for writing.  */
  73   errno = 0;
  74   ASSERT (func (".", O_WRONLY) == -1);
  75   ASSERT (errno == EISDIR || errno == EACCES);
  76
  77   /* /dev/null must exist, and be writable.  */
  78   fd = func ("/dev/null", O_RDONLY);
  79   ASSERT (0 <= fd);
  80   {
  81     char c;
  82     ASSERT (read (fd, &c, 1) == 0);
  83   }
  84   ASSERT (close (fd) == 0);
  85   fd = func ("/dev/null", O_WRONLY);
  86   ASSERT (0 <= fd);
  87   ASSERT (write (fd, "c", 1) == 1);
  88   ASSERT (close (fd) == 0);
  89
  90   /* Although O_NONBLOCK on regular files can be ignored, it must not
  91      cause a failure.  */
  92   fd = func (BASE "file", O_NONBLOCK | O_RDONLY);
  93   ASSERT (0 <= fd);
  94   ASSERT (close (fd) == 0);
  95
  96   /* O_CLOEXEC must be honoured.  */
  97   if (O_CLOEXEC)
  98     {
  99       /* Since the O_CLOEXEC handling goes through a special code path at its
 100          first invocation, test it twice.  */
 101       int i;
 102
 103       for (i = 0; i < 2; i++)
 104         {
 105           int flags;
 106
 107           fd = func (BASE "file", O_CLOEXEC | O_RDONLY);
 108           ASSERT (0 <= fd);
 109           flags = fcntl (fd, F_GETFD);
 110           ASSERT (flags >= 0);
 111           ASSERT ((flags & FD_CLOEXEC) != 0);
 112           ASSERT (close (fd) == 0);
 113         }
 114     }
 115
 116   /* Symlink handling, where supported.  */
 117   if (symlink (BASE "file", BASE "link") != 0)
 118     {
 119       ASSERT (unlink (BASE "file") == 0);
 120       if (print)
 121         fputs ("skipping test: symlinks not supported on this file system\n",
 122                stderr);
 123       return 77;
 124     }
 125   errno = 0;
 126   ASSERT (func (BASE "link/", O_RDONLY) == -1);
 127   ASSERT (errno == ENOTDIR);
 128   fd = func (BASE "link", O_RDONLY);
 129   ASSERT (0 <= fd);
 130   ASSERT (close (fd) == 0);
 131
 132   /* Cleanup.  */
 133   ASSERT (unlink (BASE "file") == 0);
 134   ASSERT (unlink (BASE "e.exe") == 0);
 135   ASSERT (unlink (BASE "link") == 0);
 136
 137   return 0;
 138 }