tests/test-openat.c

   1 /* Test that openat works.
   2    Copyright (C) 2009-2021 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 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 (int argc _GL_UNUSED, 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 }