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: mountns02.c
16 *
17 * Tests a private mount: private mount does not forward or receive
18 * propagation.
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 "A" private
25 * 5. Clones a new child process with CLONE_NEWNS flag
26 * 6. There are two test cases (where X is parent namespace and Y child
27 * namespace):
28 * 1)
29 * X: bind mounts "B" to "A"
30 * Y: must see "A/A" and must not see "A/B"
31 * X: umounts "A"
32 * 2)
33 * Y: bind mounts "B" to "A"
34 * X: must see "A/A" and must not see "A/B"
35 * Y: umounts A
36 ***********************************************************************/
37
38 #define _GNU_SOURCE
39 #include <sys/wait.h>
40 #include <sys/mount.h>
41 #include <stdio.h>
42 #include <errno.h>
43 #include "test.h"
44 #include "libclone.h"
45 #include "safe_macros.h"
46 #include "mountns_helper.h"
47
48
49 char *TCID = "mountns02";
50 int TST_TOTAL = 2;
51
52
53 #if defined(MS_SHARED) && defined(MS_PRIVATE) && defined(MS_REC)
54
child_func(void * arg LTP_ATTRIBUTE_UNUSED)55 int child_func(void *arg LTP_ATTRIBUTE_UNUSED)
56 {
57 int ret = 0;
58
59 TST_SAFE_CHECKPOINT_WAIT(NULL, 0);
60
61 if ((access(DIRA"/A", F_OK) != 0) || (access(DIRA"/B", F_OK) == 0))
62 ret = 2;
63
64 TST_SAFE_CHECKPOINT_WAKE_AND_WAIT(NULL, 0);
65
66 /* bind mounts DIRB to DIRA making contents of DIRB visible
67 * in DIRA */
68 if (mount(DIRB, DIRA, "none", MS_BIND, NULL) == -1) {
69 perror("mount");
70 return 1;
71 }
72
73 TST_SAFE_CHECKPOINT_WAKE_AND_WAIT(NULL, 0);
74
75 umount(DIRA);
76 return ret;
77 }
78
test(void)79 static void test(void)
80 {
81 int status;
82
83 /* unshares the mount ns */
84 if (unshare(CLONE_NEWNS) == -1)
85 tst_brkm(TBROK | TERRNO, cleanup, "unshare failed");
86 /* makes sure parent mounts/umounts have no effect on a real system */
87 SAFE_MOUNT(cleanup, "none", "/", "none", MS_REC|MS_PRIVATE, NULL);
88
89 /* bind mounts DIRA to itself */
90 SAFE_MOUNT(cleanup, DIRA, DIRA, "none", MS_BIND, NULL);
91
92 /* makes mount DIRA private */
93 SAFE_MOUNT(cleanup, "none", DIRA, "none", MS_PRIVATE, NULL);
94
95 if (do_clone_tests(CLONE_NEWNS, child_func, NULL, NULL, NULL) == -1)
96 tst_brkm(TBROK | TERRNO, cleanup, "clone failed");
97
98 /* bind mounts DIRB to DIRA making contents of DIRB visible
99 * in DIRA */
100 SAFE_MOUNT(cleanup, DIRB, DIRA, "none", MS_BIND, NULL);
101
102 TST_SAFE_CHECKPOINT_WAKE_AND_WAIT(cleanup, 0);
103
104 SAFE_UMOUNT(cleanup, DIRA);
105
106 TST_SAFE_CHECKPOINT_WAKE_AND_WAIT(cleanup, 0);
107
108 if ((access(DIRA"/A", F_OK) != 0) || (access(DIRA"/B", F_OK) == 0))
109 tst_resm(TFAIL, "private mount in child failed");
110 else
111 tst_resm(TPASS, "private mount in child passed");
112
113 TST_SAFE_CHECKPOINT_WAKE(cleanup, 0);
114
115
116 SAFE_WAIT(cleanup, &status);
117 if (WIFEXITED(status)) {
118 if ((WEXITSTATUS(status) == 0))
119 tst_resm(TPASS, "private mount in parent passed");
120 else
121 tst_resm(TFAIL, "private mount in parent failed");
122 }
123 if (WIFSIGNALED(status)) {
124 tst_resm(TBROK, "child was killed with signal %s",
125 tst_strsig(WTERMSIG(status)));
126 return;
127 }
128
129 SAFE_UMOUNT(cleanup, DIRA);
130 }
131
main(int argc,char * argv[])132 int main(int argc, char *argv[])
133 {
134 int lc;
135
136 tst_parse_opts(argc, argv, NULL, NULL);
137
138 setup();
139
140 for (lc = 0; TEST_LOOPING(lc); lc++)
141 test();
142
143 cleanup();
144 tst_exit();
145 }
146
147 #else
main(void)148 int main(void)
149 {
150 tst_brkm(TCONF, NULL, "needed mountflags are not defined");
151 }
152 #endif
153