aboutsummaryrefslogtreecommitdiff
path: root/posix/tst-execveat.c
blob: 53178c10d551aa4140d43cb37ddd5bc5267622b1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
/* Test execveat at the various corner cases.
   Copyright (C) 2021 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>
#include <sys/types.h>
#include <dirent.h>
#include <support/check.h>
#include <support/support.h>
#include <support/temp_file.h>
#include <support/xdlfcn.h>
#include <support/xstdio.h>
#include <support/xunistd.h>
#include <wait.h>
#include <support/test-driver.h>

int
call_execveat (int fd, const char *pathname, int flags, int expected_fail,
               int num)
{
  char *envp[] = { (char *) "FOO=3", NULL };
  char *argv[] = { (char *) "sh", (char *) "-c", (char *) "exit $FOO", NULL };
  pid_t pid;
  int status;

  if (test_verbose > 0)
    printf ("call line number: %d\n", num);

  pid = xfork ();
  if (pid == 0)
    {
      TEST_COMPARE (execveat (fd, pathname, argv, envp, flags), -1);
      if (errno == ENOSYS)
	exit (EXIT_UNSUPPORTED);
      else if (errno == expected_fail)
        {
          if (test_verbose > 0)
            printf ("expected fail: errno %d\n", errno);
          _exit (0);
        }
      else
        FAIL_EXIT1 ("execveat failed: %m (%d)", errno);
    }
  xwaitpid (pid, &status, 0);

  if (!WIFEXITED (status))
    FAIL_RET ("child hasn't exited normally");

  if (WIFEXITED (status))
    {
      if (WEXITSTATUS (status) == EXIT_UNSUPPORTED)
        FAIL_UNSUPPORTED ("execveat is unimplemented");
      else if (expected_fail != 0)
        TEST_COMPARE (WEXITSTATUS (status), 0);
      else
        TEST_COMPARE (WEXITSTATUS (status), 3);
    }
  return 0;
}

static int
do_test (void)
{
  DIR *dirp;
  int fd, fd_out;
  char *tmp_dir, *symlink_name, *tmp_sh;
  struct stat64 st;

  dirp = opendir ("/bin");
  if (dirp == NULL)
    FAIL_EXIT1 ("failed to open /bin");
  fd = dirfd (dirp);

  /* Call execveat for various fd/pathname combinations.  */

  /* Check the pathname relative to a valid dirfd.  */
  call_execveat (fd, "sh", 0, 0, __LINE__);
  xchdir ("/bin");
  /* Use the special value AT_FDCWD as dirfd. Quoting open(2):
     If pathname is relative and dirfd is the special value AT_FDCWD, then
     pathname is interpreted relative to the current working directory of
     the calling process.  */
  call_execveat (AT_FDCWD, "sh", 0, 0, __LINE__);
  xclose (fd);
#ifdef O_PATH
  /* Check the pathname relative to a valid dirfd with O_PATH.  */
  fd = xopen ("/bin", O_PATH | O_DIRECTORY, O_RDONLY);
  call_execveat (fd, "sh", 0, 0, __LINE__);
  xclose (fd);

  /* Check absolute pathname, dirfd should be ignored.  */
  call_execveat (AT_FDCWD, "/bin/sh", 0, 0, __LINE__);
  fd = xopen ("/usr", O_PATH | O_DIRECTORY, 0);
  /* Same check for absolute pathname, but with input file descriptor
     openend with different flags.  The dirfd should be ignored.  */
  call_execveat (fd, "/bin/sh", 0, 0, __LINE__);
  xclose (fd);
#endif

  fd = xopen ("/usr", O_RDONLY, 0);
  /* Same check for absolute pathname, but with input file descriptor
     openend with different flags.  The dirfd should be ignored.  */
  call_execveat (fd, "/bin/sh", 0, 0, __LINE__);
  xclose (fd);

  fd = xopen ("/bin/sh", O_RDONLY, 0);
  /* Check relative pathname, where dirfd does not point to a directory.  */
  call_execveat (fd, "sh", 0, ENOTDIR, __LINE__);
  /* Check absolute pathname, but dirfd is a regular file.  The dirfd
     should be ignored.  */
  call_execveat (fd, "/bin/sh", 0, 0, __LINE__);
  xclose (fd);

#ifdef O_PATH
  /* Quoting open(2): O_PATH
     Obtain a file descriptor that can be used for two purposes: to
     indicate a location in the filesystem tree and to perform
     operations that act purely at the file descriptor level.  */
  fd = xopen ("/bin/sh", O_PATH, 0);
  /* Check the empty pathname.  Dirfd is a regular file with O_PATH.  */
  call_execveat (fd, "", 0, ENOENT, __LINE__);
  /* Same check for an empty pathname, but with AT_EMPTY_PATH flag.
     Quoting open(2):
     If oldpath is an empty string, create a link to the file referenced
     by olddirfd (which may have been obtained using the open(2) O_PATH flag. */
  call_execveat (fd, "", AT_EMPTY_PATH, 0, __LINE__);
  call_execveat (fd, "", AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW, 0, __LINE__);
  xclose (fd);

  /* Create a temporary directory "tmp_dir" and create a symbolik link tmp_sh
     pointing to /bin/sh inside the tmp_dir. Open dirfd as a symbolic link.  */
  tmp_dir = support_create_temp_directory ("tst-execveat_dir");
  symlink_name = xasprintf ("%s/symlink", tmp_dir);
  xsymlink ("tmp_sh", symlink_name);
  add_temp_file (symlink_name);
  tmp_sh = xasprintf ("%s/tmp_sh", tmp_dir);
  add_temp_file (tmp_sh);
  fd_out = xopen (symlink_name, O_CREAT | O_WRONLY, 0);
  xstat ("/bin/sh", &st);
  fd = xopen ("/bin/sh", O_RDONLY, 0);
  xcopy_file_range (fd, 0, fd_out, 0, st.st_size, 0);
  xfchmod (fd_out, 0700);
  xclose (fd);
  xclose (fd_out);
  fd_out = xopen (symlink_name, O_PATH, 0);

 /* Check the empty pathname. Dirfd is a symbolic link.  */
  call_execveat (fd_out, "", 0, ENOENT, __LINE__);
  call_execveat (fd_out, "", AT_EMPTY_PATH, 0, __LINE__);
  call_execveat (fd_out, "", AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW, 0,
                 __LINE__);
  xclose (fd_out);
  free (symlink_name);
  free (tmp_sh);
  free (tmp_dir);
#endif

  /* Call execveat with closed fd, we expect this to fail with EBADF.  */
  call_execveat (fd, "sh", 0, EBADF, __LINE__);
  /* Call execveat with closed fd, we expect this to pass because the pathname is
     absolute.  */
  call_execveat (fd, "/bin/sh", 0, 0, __LINE__);

  return 0;
}

#include <support/test-driver.c>