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/* Test execveat at the various corner cases.
Copyright (C) 2021-2024 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;
#ifdef O_PATH
int fd_out;
char *tmp_dir, *symlink_name, *tmp_sh;
struct stat64 st;
#endif
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
opened 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
opened 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);
xstat64 ("/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>
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