1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (c) Linux Test Project, 2014-2020
4 *
5 * functional test for setns(2) - reassociate thread with a namespace
6 * 1. create child with CLONE_NEWUTS, set different hostname in child,
7 *    set namespace back to parent ns and check that hostname has changed
8 * 2. create child with CLONE_NEWIPC, set up shared memory in parent
9 *    and verify that child can't shmat it, then set namespace
10 *    back to parent one and verify that child is able to do shmat
11 */
12#define _GNU_SOURCE
13#include <sys/ipc.h>
14#include <sys/shm.h>
15#include <sys/stat.h>
16#include <sys/types.h>
17#include <sys/utsname.h>
18#include <sys/wait.h>
19#include <errno.h>
20#include <sched.h>
21#include <stdlib.h>
22#include <string.h>
23#include "config.h"
24#include "tst_test.h"
25#include "tst_safe_sysv_ipc.h"
26#include "lapi/syscalls.h"
27#include "setns.h"
28
29#define CHILD_STACK_SIZE (1024*1024)
30#define CP "(child) "
31
32static char *dummy_hostname = "setns_dummy_uts";
33static int ns_ipc_fd;
34static int ns_uts_fd;
35static key_t ipc_key;
36static int shmid;
37
38static void setup(void);
39static void cleanup(void);
40
41static int do_child_newuts(void *arg)
42{
43	struct utsname uts, uts_parent;
44	int ns_flag = *(int *)arg;
45
46	if (uname(&uts_parent) == -1)
47		tst_res(TFAIL|TERRNO, CP"uname");
48	tst_res(TINFO, CP"hostname (inherited from parent): %s",
49		uts_parent.nodename);
50
51	if (sethostname(dummy_hostname, strlen(dummy_hostname)) == -1)
52		tst_res(TFAIL|TERRNO, CP"sethostname");
53	if (uname(&uts) == -1)
54		tst_res(TFAIL|TERRNO, CP"uname");
55
56	tst_res(TINFO, CP"hostname changed to: %s", uts.nodename);
57	if (strcmp(uts_parent.nodename, uts.nodename) == 0) {
58		tst_res(TFAIL, CP"expected hostname to be different");
59		return 1;
60	} else {
61		tst_res(TPASS, CP"hostname is different in parent/child");
62	}
63
64	tst_res(TINFO, CP"attempting to switch ns back to parent ns");
65	if (tst_syscall(__NR_setns, ns_uts_fd, ns_flag) == -1) {
66		tst_res(TFAIL|TERRNO, CP"setns");
67		return 2;
68	}
69	if (uname(&uts) == -1)
70		tst_res(TFAIL|TERRNO, CP"uname");
71
72	tst_res(TINFO, CP"hostname: %s", uts.nodename);
73	if (strcmp(uts_parent.nodename, uts.nodename) != 0) {
74		tst_res(TFAIL, CP"expected hostname to match parent");
75		return 3;
76	} else {
77		tst_res(TPASS, CP"hostname now as expected");
78	}
79	return 0;
80}
81
82static int do_child_newipc(void *arg)
83{
84	void *p;
85	int ns_flag = *(int *)arg;
86
87	p = shmat(shmid, NULL, 0);
88	if (p == (void *) -1) {
89		tst_res(TPASS|TERRNO, CP"shmat failed as expected");
90	} else {
91		tst_res(TFAIL, CP"shmat unexpectedly suceeded");
92		shmdt(p);
93		return 1;
94	}
95
96	tst_res(TINFO, CP"attempting to switch ns back to parent ns");
97	if (tst_syscall(__NR_setns, ns_ipc_fd, ns_flag) == -1) {
98		tst_res(TFAIL|TERRNO, CP"setns");
99		return 2;
100	}
101
102	p = shmat(shmid, NULL, 0);
103	if (p == (void *) -1) {
104		tst_res(TFAIL|TERRNO, CP"shmat failed after setns");
105		return 3;
106	} else {
107		tst_res(TPASS, CP"shmat suceeded");
108		shmdt(p);
109	}
110
111	return 0;
112}
113
114static void test_flag(int clone_flag, int ns_flag, int (*fn) (void *arg))
115{
116	void *child_stack;
117	int ret, status;
118
119	child_stack = SAFE_MALLOC(CHILD_STACK_SIZE);
120
121	tst_res(TINFO, "creating child with clone_flag=0x%x, ns_flag=0x%x",
122		clone_flag, ns_flag);
123	ret = ltp_clone(SIGCHLD|clone_flag, fn, &ns_flag,
124		CHILD_STACK_SIZE, child_stack);
125	if (ret == -1)
126		tst_brk(TBROK|TERRNO, "ltp_clone");
127
128	SAFE_WAITPID(ret, &status, 0);
129	free(child_stack);
130}
131
132void test_all(void)
133{
134	if (ns_uts_fd != -1) {
135		tst_res(TINFO, "test_newuts");
136		test_flag(CLONE_NEWUTS, CLONE_NEWUTS, do_child_newuts);
137		test_flag(CLONE_NEWUTS, 0, do_child_newuts);
138	} else
139		tst_res(TCONF, "CLONE_NEWUTS is not supported");
140
141	if (ns_ipc_fd != -1) {
142		tst_res(TINFO, "test_newipc");
143		test_flag(CLONE_NEWIPC, CLONE_NEWIPC, do_child_newipc);
144		test_flag(CLONE_NEWIPC, 0, do_child_newipc);
145	} else
146		tst_res(TCONF, "CLONE_NEWIPC is not supported");
147}
148
149static void setup(void)
150{
151	char tmp[PATH_MAX];
152
153	/* runtime check if syscall is supported */
154	tst_syscall(__NR_setns, -1, 0);
155
156	/* check if kernel has CONFIG_*_NS set and exports /proc entries */
157	ns_ipc_fd = get_ns_fd(getpid(), "ipc");
158	ns_uts_fd = get_ns_fd(getpid(), "uts");
159	if (ns_ipc_fd == -1 && ns_uts_fd == -1)
160		tst_brk(TCONF, "your kernel has CONFIG_IPC_NS, "
161			"CONFIG_UTS_NS or CONFIG_PROC disabled");
162
163	SAFE_GETCWD(tmp, PATH_MAX);
164	ipc_key = ftok(tmp, 65);
165	shmid = SAFE_SHMGET(ipc_key, getpagesize(), IPC_CREAT | 0666);
166}
167
168static void cleanup(void)
169{
170	if (ns_ipc_fd != -1)
171		SAFE_CLOSE(ns_ipc_fd);
172	if (ns_uts_fd != -1)
173		SAFE_CLOSE(ns_uts_fd);
174
175	SAFE_SHMCTL(shmid, IPC_RMID, NULL);
176}
177
178static struct tst_test test = {
179	.test_all = test_all,
180	.setup = setup,
181	.cleanup = cleanup,
182	.needs_root = 1,
183};
184