1/*
2 * Copyright (c) Huawei Technologies Co., Ltd., 2015
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2 of the License, or
6 *  (at your option) any later version.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
11 * the GNU General Public License for more details.
12 */
13
14/*
15 * Verify that:
16 * The kernel imposes a limit of at least 32 nested levels on user namespaces.
17 */
18
19#define _GNU_SOURCE
20#include <sys/wait.h>
21#include <assert.h>
22#include <stdio.h>
23#include <stdlib.h>
24#include <unistd.h>
25#include <string.h>
26#include <errno.h>
27#include "userns_helper.h"
28#include "test.h"
29
30#define MAXNEST 32
31
32char *TCID = "userns07";
33int TST_TOTAL = 1;
34
35static void setup(void)
36{
37	check_newuser();
38	tst_tmpdir();
39	TST_CHECKPOINT_INIT(NULL);
40}
41
42static void cleanup(void)
43{
44	tst_rmdir();
45}
46
47static int child_fn1(void *arg)
48{
49	pid_t cpid1;
50	long level = (long)arg;
51	int status;
52	int parentuid;
53	int parentgid;
54
55	TST_SAFE_CHECKPOINT_WAIT(NULL, 0);
56
57	if (level == MAXNEST)
58		return 0;
59	cpid1 = ltp_clone_quick(CLONE_NEWUSER | SIGCHLD,
60		(void *)child_fn1, (void *)(level + 1));
61	if (cpid1 < 0) {
62		printf("level %ld:unexpected error: (%d) %s\n",
63			level, errno, strerror(errno));
64		return 1;
65	}
66
67	parentuid = geteuid();
68	parentgid = getegid();
69
70	updatemap(cpid1, UID_MAP, 0, parentuid, NULL);
71	updatemap(cpid1, GID_MAP, 0, parentgid, NULL);
72
73	TST_SAFE_CHECKPOINT_WAKE(cleanup, 0);
74
75	if (waitpid(cpid1, &status, 0) == -1)
76		return 1;
77
78	if (WIFEXITED(status) && WEXITSTATUS(status) != 0) {
79		printf("child exited abnormally\n");
80		return 1;
81	} else if (WIFSIGNALED(status)) {
82		printf("child was killed with signal = %d", WTERMSIG(status));
83		return 1;
84	}
85	return 0;
86}
87
88static void test_max_nest(void)
89{
90	pid_t cpid1;
91	int parentuid;
92	int parentgid;
93	int fd;
94	char path[BUFSIZ];
95
96	cpid1 = ltp_clone_quick(CLONE_NEWUSER | SIGCHLD,
97		(void *)child_fn1, (void *)0);
98	if (cpid1 < 0)
99		tst_brkm(TBROK | TERRNO, cleanup, "clone failed");
100
101	parentuid = geteuid();
102	parentgid = getegid();
103
104	if (access("/proc/self/setgroups", F_OK) == 0) {
105		sprintf(path, "/proc/%d/setgroups", cpid1);
106		fd = SAFE_OPEN(cleanup, path, O_WRONLY, 0644);
107		SAFE_WRITE(cleanup, 1, fd, "deny", 4);
108		SAFE_CLOSE(cleanup, fd);
109	}
110
111	updatemap(cpid1, UID_MAP, 0, parentuid, cleanup);
112	updatemap(cpid1, GID_MAP, 0, parentgid, cleanup);
113
114	TST_SAFE_CHECKPOINT_WAKE(cleanup, 0);
115	tst_record_childstatus(cleanup, cpid1);
116}
117
118int main(int argc, char *argv[])
119{
120	int lc;
121
122	setup();
123	tst_parse_opts(argc, argv, NULL, NULL);
124
125	for (lc = 0; TEST_LOOPING(lc); lc++) {
126		tst_count = 0;
127		test_max_nest();
128	}
129
130	cleanup();
131	tst_exit();
132}
133
134