1 /* Copyright (c) 2014 Red Hat, Inc.
2 *
3 * This program is free software: you can redistribute it and/or modify
4 * it under the terms of version 2 the GNU General Public License as
5 * published by the Free Software Foundation.
6 *
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
11 *
12 * You should have received a copy of the GNU General Public License
13 * along with this program. If not, see <http://www.gnu.org/licenses/>.
14 ***********************************************************************
15 * File: mountns04.c
16 *
17 * Tests an unbindable mount: unbindable mount is an unbindable
18 * private mount.
19 * Description:
20 * 1. Creates directories "A", "B" and files "A/A", "B/B"
21 * 2. Unshares mount namespace and makes it private (so mounts/umounts
22 * have no effect on a real system)
23 * 3. Bind mounts directory "A" to "A"
24 * 4. Makes directory directory "A" unbindable
25 * 5. Tries to bind mount unbindable "A" to "B":
26 * - if it fails, test passes
27 * - if it passes, test fails
28 ***********************************************************************/
29
30 #define _GNU_SOURCE
31 #include <sys/wait.h>
32 #include <sys/mount.h>
33 #include <stdio.h>
34 #include <errno.h>
35 #include "mountns_helper.h"
36 #include "test.h"
37 #include "safe_macros.h"
38
39 char *TCID = "mountns04";
40 int TST_TOTAL = 1;
41
42 #if defined(MS_SHARED) && defined(MS_PRIVATE) \
43 && defined(MS_REC) && defined(MS_UNBINDABLE)
44
test(void)45 static void test(void)
46 {
47 /* unshares the mount ns */
48 if (unshare(CLONE_NEWNS) == -1)
49 tst_brkm(TBROK | TERRNO, cleanup, "unshare failed");
50 /* makes sure mounts/umounts have no effect on a real system */
51 SAFE_MOUNT(cleanup, "none", "/", "none", MS_REC|MS_PRIVATE, NULL);
52
53 /* bind mounts DIRA to itself */
54 SAFE_MOUNT(cleanup, DIRA, DIRA, "none", MS_BIND, NULL);
55 /* makes mount DIRA unbindable */
56 SAFE_MOUNT(cleanup, "none", DIRA, "none", MS_UNBINDABLE, NULL);
57
58 /* tries to bind mount unbindable DIRA to DIRB which should fail */
59 if (mount(DIRA, DIRB, "none", MS_BIND, NULL) == -1) {
60 tst_resm(TPASS, "unbindable mount passed");
61 } else {
62 SAFE_UMOUNT(cleanup, DIRB);
63 tst_resm(TFAIL, "unbindable mount faled");
64 }
65
66 SAFE_UMOUNT(cleanup, DIRA);
67 }
68
main(int argc,char * argv[])69 int main(int argc, char *argv[])
70 {
71 int lc;
72
73 tst_parse_opts(argc, argv, NULL, NULL);
74
75 setup();
76
77 for (lc = 0; TEST_LOOPING(lc); lc++)
78 test();
79
80 cleanup();
81 tst_exit();
82 }
83
84 #else
main(void)85 int main(void)
86 {
87 tst_brkm(TCONF, NULL, "needed mountflags are not defined");
88 }
89 #endif
90