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/* Smoke test for faccessat with different UID/GID combinations. Needs root
access.
Copyright The GNU Toolchain Authors.
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 <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <pwd.h>
#include <support/check.h>
#include <support/namespace.h>
#include <support/support.h>
#include <support/temp_file.h>
#include <support/test-driver.h>
#include <support/xdirent.h>
#include <support/xunistd.h>
#define SOMEFILE "some-file"
static int dir_fd;
uid_t users[3];
gid_t groups[3];
struct test_case
{
int mode;
uid_t uid;
uid_t euid;
gid_t gid;
gid_t egid;
int flags;
bool succeeds;
};
static void
run_one_test_child (void *in)
{
struct test_case *t = (struct test_case *) in;
printf ("TEST: MODE=%s, UID=%d, EUID=%d, GID=%d, EGID=%d, FLAGS=%s: ",
t->mode == R_OK ? "R_OK" : "W_OK", t->uid, t->euid, t->gid, t->egid,
t->flags ? "AT_EACCESS" : "0");
if (setregid (t->gid, t->egid) != 0)
FAIL_EXIT1 ("Could not change group: %m\n");
if (setreuid (t->uid, t->euid) != 0)
FAIL_EXIT1 ("Could not change user: %m\n");
if (faccessat (dir_fd, SOMEFILE, t->mode, t->flags) != 0 && t->succeeds)
FAIL_EXIT1 ("faccessat failed: %m\n");
if (!t->succeeds && errno != EACCES)
FAIL_EXIT1 ("Unexpected faccessat failure: %m\n");
printf ("OK%s\n", !t->succeeds ? " (FAILED with EACCES)" : "");
}
static void
run_one_test (int mode, int u, int eu, int g, int eg, int flags, bool succeeds)
{
struct test_case t =
{mode, users[u], users[eu], groups[g], groups[eg], flags, succeeds};
support_isolate_in_subprocess (run_one_test_child, &t);
}
static int
do_test (void)
{
/* We need to start as root. */
if (getuid () != 0)
FAIL_UNSUPPORTED ("Test needs to be run as root (UID 0)\n");
/* Collect 3 distinct users and groups to test with. */
struct passwd *ent = NULL;
int count = 0;
while ((ent = getpwent ()) != NULL && count < 3)
{
if (ent->pw_uid == 0 || ent->pw_gid == 0)
continue;
int i = count;
bool skip = false;
while (i > 0)
if (groups[--i] == ent->pw_gid)
skip = true;
if (skip)
continue;
users[count] = ent->pw_uid;
groups[count++] = ent->pw_gid;
}
if (count < 3)
FAIL_UNSUPPORTED ("Not enough users in the system to do this test\n");
printf ("Testing with UID/GID:\n");
while (--count >= 0)
printf (" UID: %d, GID: %d\n", users[count], groups[count]);
printf ("\n");
char *tempdir = support_create_temp_directory ("tst-faccessat-setuid.");
dir_fd = xopen (tempdir, O_RDONLY | O_DIRECTORY, 0);
xfchmod (dir_fd, 0777);
/* Now, create a file in it, which will be our test case. */
int fd = openat (dir_fd, SOMEFILE, O_CREAT|O_RDWR|O_EXCL, 0640);
if (fd == -1)
{
if (errno == ENOSYS)
FAIL_UNSUPPORTED ("*at functions not supported");
FAIL_EXIT1 ("file creation failed");
}
xwrite (fd, "hello", 5);
if (fchown (fd, users[0], groups[1]) == -1)
FAIL_EXIT1 ("fchown failed: %m\n");
xclose (fd);
char *somefile = xasprintf ("%s/" SOMEFILE, tempdir);
add_temp_file (somefile);
/* Finally, run through the combinations. */
for (int u = 0; u < 3; u++)
for (int eu = 0; eu < 3; eu++)
for (int g = 0; g < 3; g++)
for (int eg = 0; eg < 3; eg++)
{
run_one_test (R_OK, u, eu, g, eg, 0, u == 0 || g == 1);
run_one_test (W_OK, u, eu, g, eg, 0, u == 0);
run_one_test (R_OK, u, eu, g, eg, AT_EACCESS, eu == 0 || eg == 1);
run_one_test (W_OK, u, eu, g, eg, AT_EACCESS, eu == 0);
}
xclose (dir_fd);
free (tempdir);
free (somefile);
return 0;
}
#include <support/test-driver.c>
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