1 | /* Test execveat at the various corner cases. |
2 | Copyright (C) 2021-2022 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | The GNU C Library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library; if not, see |
17 | <https://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <fcntl.h> |
20 | #include <errno.h> |
21 | #include <stdlib.h> |
22 | #include <sys/types.h> |
23 | #include <dirent.h> |
24 | #include <support/check.h> |
25 | #include <support/support.h> |
26 | #include <support/temp_file.h> |
27 | #include <support/xdlfcn.h> |
28 | #include <support/xstdio.h> |
29 | #include <support/xunistd.h> |
30 | #include <wait.h> |
31 | #include <support/test-driver.h> |
32 | |
33 | int |
34 | call_execveat (int fd, const char *pathname, int flags, int expected_fail, |
35 | int num) |
36 | { |
37 | char *envp[] = { (char *) "FOO=3" , NULL }; |
38 | char *argv[] = { (char *) "sh" , (char *) "-c" , (char *) "exit $FOO" , NULL }; |
39 | pid_t pid; |
40 | int status; |
41 | |
42 | if (test_verbose > 0) |
43 | printf (format: "call line number: %d\n" , num); |
44 | |
45 | pid = xfork (); |
46 | if (pid == 0) |
47 | { |
48 | TEST_COMPARE (execveat (fd, pathname, argv, envp, flags), -1); |
49 | if (errno == ENOSYS) |
50 | exit (EXIT_UNSUPPORTED); |
51 | else if (errno == expected_fail) |
52 | { |
53 | if (test_verbose > 0) |
54 | printf (format: "expected fail: errno %d\n" , errno); |
55 | _exit (0); |
56 | } |
57 | else |
58 | FAIL_EXIT1 ("execveat failed: %m (%d)" , errno); |
59 | } |
60 | xwaitpid (pid, status: &status, flags: 0); |
61 | |
62 | if (!WIFEXITED (status)) |
63 | FAIL_RET ("child hasn't exited normally" ); |
64 | |
65 | if (WIFEXITED (status)) |
66 | { |
67 | if (WEXITSTATUS (status) == EXIT_UNSUPPORTED) |
68 | FAIL_UNSUPPORTED ("execveat is unimplemented" ); |
69 | else if (expected_fail != 0) |
70 | TEST_COMPARE (WEXITSTATUS (status), 0); |
71 | else |
72 | TEST_COMPARE (WEXITSTATUS (status), 3); |
73 | } |
74 | return 0; |
75 | } |
76 | |
77 | static int |
78 | do_test (void) |
79 | { |
80 | DIR *dirp; |
81 | int fd; |
82 | #ifdef O_PATH |
83 | int fd_out; |
84 | char *tmp_dir, *symlink_name, *tmp_sh; |
85 | struct stat64 st; |
86 | #endif |
87 | |
88 | dirp = opendir (name: "/bin" ); |
89 | if (dirp == NULL) |
90 | FAIL_EXIT1 ("failed to open /bin" ); |
91 | fd = dirfd (dirp); |
92 | |
93 | /* Call execveat for various fd/pathname combinations. */ |
94 | |
95 | /* Check the pathname relative to a valid dirfd. */ |
96 | call_execveat (fd, pathname: "sh" , flags: 0, expected_fail: 0, __LINE__); |
97 | xchdir (path: "/bin" ); |
98 | /* Use the special value AT_FDCWD as dirfd. Quoting open(2): |
99 | If pathname is relative and dirfd is the special value AT_FDCWD, then |
100 | pathname is interpreted relative to the current working directory of |
101 | the calling process. */ |
102 | call_execveat (AT_FDCWD, pathname: "sh" , flags: 0, expected_fail: 0, __LINE__); |
103 | xclose (fd); |
104 | #ifdef O_PATH |
105 | /* Check the pathname relative to a valid dirfd with O_PATH. */ |
106 | fd = xopen (path: "/bin" , O_PATH | O_DIRECTORY, O_RDONLY); |
107 | call_execveat (fd, pathname: "sh" , flags: 0, expected_fail: 0, __LINE__); |
108 | xclose (fd); |
109 | |
110 | /* Check absolute pathname, dirfd should be ignored. */ |
111 | call_execveat (AT_FDCWD, pathname: "/bin/sh" , flags: 0, expected_fail: 0, __LINE__); |
112 | fd = xopen (path: "/usr" , O_PATH | O_DIRECTORY, 0); |
113 | /* Same check for absolute pathname, but with input file descriptor |
114 | openend with different flags. The dirfd should be ignored. */ |
115 | call_execveat (fd, pathname: "/bin/sh" , flags: 0, expected_fail: 0, __LINE__); |
116 | xclose (fd); |
117 | #endif |
118 | |
119 | fd = xopen (path: "/usr" , O_RDONLY, 0); |
120 | /* Same check for absolute pathname, but with input file descriptor |
121 | openend with different flags. The dirfd should be ignored. */ |
122 | call_execveat (fd, pathname: "/bin/sh" , flags: 0, expected_fail: 0, __LINE__); |
123 | xclose (fd); |
124 | |
125 | fd = xopen (path: "/bin/sh" , O_RDONLY, 0); |
126 | /* Check relative pathname, where dirfd does not point to a directory. */ |
127 | call_execveat (fd, pathname: "sh" , flags: 0, ENOTDIR, __LINE__); |
128 | /* Check absolute pathname, but dirfd is a regular file. The dirfd |
129 | should be ignored. */ |
130 | call_execveat (fd, pathname: "/bin/sh" , flags: 0, expected_fail: 0, __LINE__); |
131 | xclose (fd); |
132 | |
133 | #ifdef O_PATH |
134 | /* Quoting open(2): O_PATH |
135 | Obtain a file descriptor that can be used for two purposes: to |
136 | indicate a location in the filesystem tree and to perform |
137 | operations that act purely at the file descriptor level. */ |
138 | fd = xopen (path: "/bin/sh" , O_PATH, 0); |
139 | /* Check the empty pathname. Dirfd is a regular file with O_PATH. */ |
140 | call_execveat (fd, pathname: "" , flags: 0, ENOENT, __LINE__); |
141 | /* Same check for an empty pathname, but with AT_EMPTY_PATH flag. |
142 | Quoting open(2): |
143 | If oldpath is an empty string, create a link to the file referenced |
144 | by olddirfd (which may have been obtained using the open(2) O_PATH flag. */ |
145 | call_execveat (fd, pathname: "" , AT_EMPTY_PATH, expected_fail: 0, __LINE__); |
146 | call_execveat (fd, pathname: "" , AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW, expected_fail: 0, __LINE__); |
147 | xclose (fd); |
148 | |
149 | /* Create a temporary directory "tmp_dir" and create a symbolik link tmp_sh |
150 | pointing to /bin/sh inside the tmp_dir. Open dirfd as a symbolic link. */ |
151 | tmp_dir = support_create_temp_directory (base: "tst-execveat_dir" ); |
152 | symlink_name = xasprintf (format: "%s/symlink" , tmp_dir); |
153 | xsymlink (target: "tmp_sh" , linkpath: symlink_name); |
154 | add_temp_file (name: symlink_name); |
155 | tmp_sh = xasprintf (format: "%s/tmp_sh" , tmp_dir); |
156 | add_temp_file (name: tmp_sh); |
157 | fd_out = xopen (path: symlink_name, O_CREAT | O_WRONLY, 0); |
158 | xstat (path: "/bin/sh" , &st); |
159 | fd = xopen (path: "/bin/sh" , O_RDONLY, 0); |
160 | xcopy_file_range (fd_in: fd, off_in: 0, fd_out, off_out: 0, len: st.st_size, flags: 0); |
161 | xfchmod (fd: fd_out, mode: 0700); |
162 | xclose (fd); |
163 | xclose (fd_out); |
164 | fd_out = xopen (path: symlink_name, O_PATH, 0); |
165 | |
166 | /* Check the empty pathname. Dirfd is a symbolic link. */ |
167 | call_execveat (fd: fd_out, pathname: "" , flags: 0, ENOENT, __LINE__); |
168 | call_execveat (fd: fd_out, pathname: "" , AT_EMPTY_PATH, expected_fail: 0, __LINE__); |
169 | call_execveat (fd: fd_out, pathname: "" , AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW, expected_fail: 0, |
170 | __LINE__); |
171 | xclose (fd_out); |
172 | free (ptr: symlink_name); |
173 | free (ptr: tmp_sh); |
174 | free (ptr: tmp_dir); |
175 | #endif |
176 | |
177 | /* Call execveat with closed fd, we expect this to fail with EBADF. */ |
178 | call_execveat (fd, pathname: "sh" , flags: 0, EBADF, __LINE__); |
179 | /* Call execveat with closed fd, we expect this to pass because the pathname is |
180 | absolute. */ |
181 | call_execveat (fd, pathname: "/bin/sh" , flags: 0, expected_fail: 0, __LINE__); |
182 | |
183 | return 0; |
184 | } |
185 | |
186 | #include <support/test-driver.c> |
187 | |