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
32 static char *dummy_hostname = "setns_dummy_uts";
33 static int ns_ipc_fd;
34 static int ns_uts_fd;
35 static key_t ipc_key;
36 static int shmid;
37
38 static void setup(void);
39 static void cleanup(void);
40
do_child_newuts(void * arg)41 static 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
do_child_newipc(void * arg)82 static 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
test_flag(int clone_flag,int ns_flag,int (* fn)(void * arg))114 static 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
test_all(void)132 void 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
setup(void)149 static 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
cleanup(void)168 static 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
178 static struct tst_test test = {
179 .test_all = test_all,
180 .setup = setup,
181 .cleanup = cleanup,
182 .needs_root = 1,
183 };
184