pidns03.c revision d1e794d62b1bf619df8390535e4c2a58899b1145 
1/* Copyright (c) 2014 Red Hat, Inc. All rights reserved.
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: pidns03.c
16 *
17 * Description:
18 * Clones a new child process with CLONE_NEWPID flag - the new child
19 * process mounts procfs to a "proc" directory and checks if it belongs
20 * to a new pid namespace by:
21 * 1. reading value of "proc/self", which is symlink
22 *    to directory named after current pid number
23 * 2. comparing read value (PID) with "1"
24 */
25
26#define _GNU_SOURCE
27#include <sys/wait.h>
28#include <sys/mount.h>
29#include <sys/types.h>
30#include <stdio.h>
31#include <string.h>
32#include <unistd.h>
33#include <errno.h>
34#include "test.h"
35#include "safe_macros.h"
36#include "libclone.h"
37#include "pidns_helper.h"
38
39#define PROCDIR "proc"
40char *TCID = "pidns03";
41int TST_TOTAL	= 1;
42
43
44static void cleanup(void)
45{
46	tst_rmdir();
47}
48
49static void setup(void)
50{
51	tst_require_root();
52	check_newpid();
53	tst_tmpdir();
54	SAFE_MKDIR(cleanup, PROCDIR, 0555);
55}
56
57int child_func(void *arg)
58{
59	char buf[10];
60
61	if (mount("none", PROCDIR, "proc", MS_RDONLY, NULL) == -1) {
62		perror("mount");
63		return 1;
64	}
65
66	/* self is symlink to directory named after current pid number */
67	if (readlink(PROCDIR"/self", buf, sizeof(buf)) == -1) {
68		perror("readlink");
69		umount(PROCDIR);
70		return 1;
71	}
72
73	umount(PROCDIR);
74
75	/* child should have PID 1 in a new pid namespace - if true
76	 * procfs belongs to the new pid namespace */
77	if (strcmp(buf, "1")) {
78		fprintf(stderr, "%s contains: %s\n", PROCDIR"/self", buf);
79		return 1;
80	}
81
82	return 0;
83}
84
85static void test(void)
86{
87	int status;
88
89	if (do_clone_tests(CLONE_NEWPID, child_func, NULL, NULL, NULL) == -1)
90		tst_brkm(TBROK | TERRNO, cleanup, "clone failed");
91
92	SAFE_WAIT(cleanup, &status);
93
94	if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
95		tst_resm(TPASS, "mounting procfs in a new namespace");
96		return;
97	}
98
99	if (WIFSIGNALED(status)) {
100		tst_resm(TFAIL, "child was killed with signal %s",
101			 tst_strsig(WTERMSIG(status)));
102		return;
103	}
104
105	tst_resm(TFAIL, "mounting procfs in a new namespace");
106}
107
108int main(int argc, char *argv[])
109{
110	int lc;
111
112	tst_parse_opts(argc, argv, NULL, NULL);
113
114	setup();
115
116	for (lc = 0; TEST_LOOPING(lc); lc++)
117		test();
118
119	cleanup();
120	tst_exit();
121}
122