xref: /linux/tools/testing/selftests/namespaces/nsid_test.c (revision 85cdaca6970028bf6f544c355c90035586836ddf)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include <assert.h>
4 #include <fcntl.h>
5 #include <inttypes.h>
6 #include <libgen.h>
7 #include <limits.h>
8 #include <pthread.h>
9 #include <signal.h>
10 #include <string.h>
11 #include <sys/mount.h>
12 #include <poll.h>
13 #include <sys/epoll.h>
14 #include <sys/resource.h>
15 #include <sys/stat.h>
16 #include <sys/socket.h>
17 #include <sys/un.h>
18 #include <sys/wait.h>
19 #include <unistd.h>
20 #include <linux/fs.h>
21 #include <linux/limits.h>
22 #include <linux/nsfs.h>
23 #include "kselftest_harness.h"
24 
25 /* Fixture for tests that create child processes */
26 FIXTURE(nsid) {
27 	pid_t child_pid;
28 	pid_t grandchild_pid;
29 };
30 
31 FIXTURE_SETUP(nsid) {
32 	self->child_pid = 0;
33 	self->grandchild_pid = 0;
34 }
35 
36 FIXTURE_TEARDOWN(nsid) {
37 	/*
38 	 * Kill grandchild first: timens_separate and pidns_separate fork a
39 	 * grandchild that calls pause().  It is reparented to init on child
40 	 * exit and keeps the test runner's tap pipe open, hanging the runner.
41 	 */
42 	if (self->grandchild_pid > 0) {
43 		kill(self->grandchild_pid, SIGKILL);
44 		waitpid(self->grandchild_pid, NULL, 0);
45 	}
46 	if (self->child_pid > 0) {
47 		kill(self->child_pid, SIGKILL);
48 		waitpid(self->child_pid, NULL, 0);
49 	}
50 }
51 
52 TEST(nsid_mntns_basic)
53 {
54 	__u64 mnt_ns_id = 0;
55 	int fd_mntns;
56 	int ret;
57 
58 	/* Open the current mount namespace */
59 	fd_mntns = open("/proc/self/ns/mnt", O_RDONLY);
60 	ASSERT_GE(fd_mntns, 0);
61 
62 	/* Get the mount namespace ID */
63 	ret = ioctl(fd_mntns, NS_GET_MNTNS_ID, &mnt_ns_id);
64 	ASSERT_EQ(ret, 0);
65 	ASSERT_NE(mnt_ns_id, 0);
66 
67 	/* Verify we can get the same ID again */
68 	__u64 mnt_ns_id2 = 0;
69 	ret = ioctl(fd_mntns, NS_GET_ID, &mnt_ns_id2);
70 	ASSERT_EQ(ret, 0);
71 	ASSERT_EQ(mnt_ns_id, mnt_ns_id2);
72 
73 	close(fd_mntns);
74 }
75 
76 TEST_F(nsid, mntns_separate)
77 {
78 	__u64 parent_mnt_ns_id = 0;
79 	__u64 child_mnt_ns_id = 0;
80 	int fd_parent_mntns, fd_child_mntns;
81 	int ret;
82 	pid_t pid;
83 	int pipefd[2];
84 
85 	/* Get parent's mount namespace ID */
86 	fd_parent_mntns = open("/proc/self/ns/mnt", O_RDONLY);
87 	ASSERT_GE(fd_parent_mntns, 0);
88 	ret = ioctl(fd_parent_mntns, NS_GET_ID, &parent_mnt_ns_id);
89 	ASSERT_EQ(ret, 0);
90 	ASSERT_NE(parent_mnt_ns_id, 0);
91 
92 	/* Create a pipe for synchronization */
93 	ASSERT_EQ(pipe(pipefd), 0);
94 
95 	pid = fork();
96 	ASSERT_GE(pid, 0);
97 
98 	if (pid == 0) {
99 		/* Child process */
100 		close(pipefd[0]);
101 
102 		/* Create new mount namespace */
103 		ret = unshare(CLONE_NEWNS);
104 		if (ret != 0) {
105 			/* Skip test if we don't have permission */
106 			if (errno == EPERM || errno == EACCES) {
107 				write(pipefd[1], "S", 1); /* Signal skip */
108 				_exit(0);
109 			}
110 			_exit(1);
111 		}
112 
113 		/* Signal success */
114 		write(pipefd[1], "Y", 1);
115 		close(pipefd[1]);
116 
117 		/* Keep namespace alive */
118 		pause();
119 		_exit(0);
120 	}
121 
122 	/* Track child for cleanup */
123 	self->child_pid = pid;
124 
125 	/* Parent process */
126 	close(pipefd[1]);
127 
128 	char buf;
129 	ASSERT_EQ(read(pipefd[0], &buf, 1), 1);
130 	close(pipefd[0]);
131 
132 	if (buf == 'S') {
133 		/* Child couldn't create namespace, skip test */
134 		close(fd_parent_mntns);
135 		SKIP(return, "No permission to create mount namespace");
136 	}
137 
138 	ASSERT_EQ(buf, 'Y');
139 
140 	/* Open child's mount namespace */
141 	char path[256];
142 	snprintf(path, sizeof(path), "/proc/%d/ns/mnt", pid);
143 	fd_child_mntns = open(path, O_RDONLY);
144 	ASSERT_GE(fd_child_mntns, 0);
145 
146 	/* Get child's mount namespace ID */
147 	ret = ioctl(fd_child_mntns, NS_GET_ID, &child_mnt_ns_id);
148 	ASSERT_EQ(ret, 0);
149 	ASSERT_NE(child_mnt_ns_id, 0);
150 
151 	/* Parent and child should have different mount namespace IDs */
152 	ASSERT_NE(parent_mnt_ns_id, child_mnt_ns_id);
153 
154 	close(fd_parent_mntns);
155 	close(fd_child_mntns);
156 }
157 
158 TEST(nsid_cgroupns_basic)
159 {
160 	__u64 cgroup_ns_id = 0;
161 	int fd_cgroupns;
162 	int ret;
163 
164 	/* Open the current cgroup namespace */
165 	fd_cgroupns = open("/proc/self/ns/cgroup", O_RDONLY);
166 	ASSERT_GE(fd_cgroupns, 0);
167 
168 	/* Get the cgroup namespace ID */
169 	ret = ioctl(fd_cgroupns, NS_GET_ID, &cgroup_ns_id);
170 	ASSERT_EQ(ret, 0);
171 	ASSERT_NE(cgroup_ns_id, 0);
172 
173 	/* Verify we can get the same ID again */
174 	__u64 cgroup_ns_id2 = 0;
175 	ret = ioctl(fd_cgroupns, NS_GET_ID, &cgroup_ns_id2);
176 	ASSERT_EQ(ret, 0);
177 	ASSERT_EQ(cgroup_ns_id, cgroup_ns_id2);
178 
179 	close(fd_cgroupns);
180 }
181 
182 TEST_F(nsid, cgroupns_separate)
183 {
184 	__u64 parent_cgroup_ns_id = 0;
185 	__u64 child_cgroup_ns_id = 0;
186 	int fd_parent_cgroupns, fd_child_cgroupns;
187 	int ret;
188 	pid_t pid;
189 	int pipefd[2];
190 
191 	/* Get parent's cgroup namespace ID */
192 	fd_parent_cgroupns = open("/proc/self/ns/cgroup", O_RDONLY);
193 	ASSERT_GE(fd_parent_cgroupns, 0);
194 	ret = ioctl(fd_parent_cgroupns, NS_GET_ID, &parent_cgroup_ns_id);
195 	ASSERT_EQ(ret, 0);
196 	ASSERT_NE(parent_cgroup_ns_id, 0);
197 
198 	/* Create a pipe for synchronization */
199 	ASSERT_EQ(pipe(pipefd), 0);
200 
201 	pid = fork();
202 	ASSERT_GE(pid, 0);
203 
204 	if (pid == 0) {
205 		/* Child process */
206 		close(pipefd[0]);
207 
208 		/* Create new cgroup namespace */
209 		ret = unshare(CLONE_NEWCGROUP);
210 		if (ret != 0) {
211 			/* Skip test if we don't have permission */
212 			if (errno == EPERM || errno == EACCES) {
213 				write(pipefd[1], "S", 1); /* Signal skip */
214 				_exit(0);
215 			}
216 			_exit(1);
217 		}
218 
219 		/* Signal success */
220 		write(pipefd[1], "Y", 1);
221 		close(pipefd[1]);
222 
223 		/* Keep namespace alive */
224 		pause();
225 		_exit(0);
226 	}
227 
228 	/* Track child for cleanup */
229 	self->child_pid = pid;
230 
231 	/* Parent process */
232 	close(pipefd[1]);
233 
234 	char buf;
235 	ASSERT_EQ(read(pipefd[0], &buf, 1), 1);
236 	close(pipefd[0]);
237 
238 	if (buf == 'S') {
239 		/* Child couldn't create namespace, skip test */
240 		close(fd_parent_cgroupns);
241 		SKIP(return, "No permission to create cgroup namespace");
242 	}
243 
244 	ASSERT_EQ(buf, 'Y');
245 
246 	/* Open child's cgroup namespace */
247 	char path[256];
248 	snprintf(path, sizeof(path), "/proc/%d/ns/cgroup", pid);
249 	fd_child_cgroupns = open(path, O_RDONLY);
250 	ASSERT_GE(fd_child_cgroupns, 0);
251 
252 	/* Get child's cgroup namespace ID */
253 	ret = ioctl(fd_child_cgroupns, NS_GET_ID, &child_cgroup_ns_id);
254 	ASSERT_EQ(ret, 0);
255 	ASSERT_NE(child_cgroup_ns_id, 0);
256 
257 	/* Parent and child should have different cgroup namespace IDs */
258 	ASSERT_NE(parent_cgroup_ns_id, child_cgroup_ns_id);
259 
260 	close(fd_parent_cgroupns);
261 	close(fd_child_cgroupns);
262 }
263 
264 TEST(nsid_ipcns_basic)
265 {
266 	__u64 ipc_ns_id = 0;
267 	int fd_ipcns;
268 	int ret;
269 
270 	/* Open the current IPC namespace */
271 	fd_ipcns = open("/proc/self/ns/ipc", O_RDONLY);
272 	ASSERT_GE(fd_ipcns, 0);
273 
274 	/* Get the IPC namespace ID */
275 	ret = ioctl(fd_ipcns, NS_GET_ID, &ipc_ns_id);
276 	ASSERT_EQ(ret, 0);
277 	ASSERT_NE(ipc_ns_id, 0);
278 
279 	/* Verify we can get the same ID again */
280 	__u64 ipc_ns_id2 = 0;
281 	ret = ioctl(fd_ipcns, NS_GET_ID, &ipc_ns_id2);
282 	ASSERT_EQ(ret, 0);
283 	ASSERT_EQ(ipc_ns_id, ipc_ns_id2);
284 
285 	close(fd_ipcns);
286 }
287 
288 TEST_F(nsid, ipcns_separate)
289 {
290 	__u64 parent_ipc_ns_id = 0;
291 	__u64 child_ipc_ns_id = 0;
292 	int fd_parent_ipcns, fd_child_ipcns;
293 	int ret;
294 	pid_t pid;
295 	int pipefd[2];
296 
297 	/* Get parent's IPC namespace ID */
298 	fd_parent_ipcns = open("/proc/self/ns/ipc", O_RDONLY);
299 	ASSERT_GE(fd_parent_ipcns, 0);
300 	ret = ioctl(fd_parent_ipcns, NS_GET_ID, &parent_ipc_ns_id);
301 	ASSERT_EQ(ret, 0);
302 	ASSERT_NE(parent_ipc_ns_id, 0);
303 
304 	/* Create a pipe for synchronization */
305 	ASSERT_EQ(pipe(pipefd), 0);
306 
307 	pid = fork();
308 	ASSERT_GE(pid, 0);
309 
310 	if (pid == 0) {
311 		/* Child process */
312 		close(pipefd[0]);
313 
314 		/* Create new IPC namespace */
315 		ret = unshare(CLONE_NEWIPC);
316 		if (ret != 0) {
317 			/* Skip test if we don't have permission */
318 			if (errno == EPERM || errno == EACCES) {
319 				write(pipefd[1], "S", 1); /* Signal skip */
320 				_exit(0);
321 			}
322 			_exit(1);
323 		}
324 
325 		/* Signal success */
326 		write(pipefd[1], "Y", 1);
327 		close(pipefd[1]);
328 
329 		/* Keep namespace alive */
330 		pause();
331 		_exit(0);
332 	}
333 
334 	/* Track child for cleanup */
335 	self->child_pid = pid;
336 
337 	/* Parent process */
338 	close(pipefd[1]);
339 
340 	char buf;
341 	ASSERT_EQ(read(pipefd[0], &buf, 1), 1);
342 	close(pipefd[0]);
343 
344 	if (buf == 'S') {
345 		/* Child couldn't create namespace, skip test */
346 		close(fd_parent_ipcns);
347 		SKIP(return, "No permission to create IPC namespace");
348 	}
349 
350 	ASSERT_EQ(buf, 'Y');
351 
352 	/* Open child's IPC namespace */
353 	char path[256];
354 	snprintf(path, sizeof(path), "/proc/%d/ns/ipc", pid);
355 	fd_child_ipcns = open(path, O_RDONLY);
356 	ASSERT_GE(fd_child_ipcns, 0);
357 
358 	/* Get child's IPC namespace ID */
359 	ret = ioctl(fd_child_ipcns, NS_GET_ID, &child_ipc_ns_id);
360 	ASSERT_EQ(ret, 0);
361 	ASSERT_NE(child_ipc_ns_id, 0);
362 
363 	/* Parent and child should have different IPC namespace IDs */
364 	ASSERT_NE(parent_ipc_ns_id, child_ipc_ns_id);
365 
366 	close(fd_parent_ipcns);
367 	close(fd_child_ipcns);
368 }
369 
370 TEST(nsid_utsns_basic)
371 {
372 	__u64 uts_ns_id = 0;
373 	int fd_utsns;
374 	int ret;
375 
376 	/* Open the current UTS namespace */
377 	fd_utsns = open("/proc/self/ns/uts", O_RDONLY);
378 	ASSERT_GE(fd_utsns, 0);
379 
380 	/* Get the UTS namespace ID */
381 	ret = ioctl(fd_utsns, NS_GET_ID, &uts_ns_id);
382 	ASSERT_EQ(ret, 0);
383 	ASSERT_NE(uts_ns_id, 0);
384 
385 	/* Verify we can get the same ID again */
386 	__u64 uts_ns_id2 = 0;
387 	ret = ioctl(fd_utsns, NS_GET_ID, &uts_ns_id2);
388 	ASSERT_EQ(ret, 0);
389 	ASSERT_EQ(uts_ns_id, uts_ns_id2);
390 
391 	close(fd_utsns);
392 }
393 
394 TEST_F(nsid, utsns_separate)
395 {
396 	__u64 parent_uts_ns_id = 0;
397 	__u64 child_uts_ns_id = 0;
398 	int fd_parent_utsns, fd_child_utsns;
399 	int ret;
400 	pid_t pid;
401 	int pipefd[2];
402 
403 	/* Get parent's UTS namespace ID */
404 	fd_parent_utsns = open("/proc/self/ns/uts", O_RDONLY);
405 	ASSERT_GE(fd_parent_utsns, 0);
406 	ret = ioctl(fd_parent_utsns, NS_GET_ID, &parent_uts_ns_id);
407 	ASSERT_EQ(ret, 0);
408 	ASSERT_NE(parent_uts_ns_id, 0);
409 
410 	/* Create a pipe for synchronization */
411 	ASSERT_EQ(pipe(pipefd), 0);
412 
413 	pid = fork();
414 	ASSERT_GE(pid, 0);
415 
416 	if (pid == 0) {
417 		/* Child process */
418 		close(pipefd[0]);
419 
420 		/* Create new UTS namespace */
421 		ret = unshare(CLONE_NEWUTS);
422 		if (ret != 0) {
423 			/* Skip test if we don't have permission */
424 			if (errno == EPERM || errno == EACCES) {
425 				write(pipefd[1], "S", 1); /* Signal skip */
426 				_exit(0);
427 			}
428 			_exit(1);
429 		}
430 
431 		/* Signal success */
432 		write(pipefd[1], "Y", 1);
433 		close(pipefd[1]);
434 
435 		/* Keep namespace alive */
436 		pause();
437 		_exit(0);
438 	}
439 
440 	/* Track child for cleanup */
441 	self->child_pid = pid;
442 
443 	/* Parent process */
444 	close(pipefd[1]);
445 
446 	char buf;
447 	ASSERT_EQ(read(pipefd[0], &buf, 1), 1);
448 	close(pipefd[0]);
449 
450 	if (buf == 'S') {
451 		/* Child couldn't create namespace, skip test */
452 		close(fd_parent_utsns);
453 		SKIP(return, "No permission to create UTS namespace");
454 	}
455 
456 	ASSERT_EQ(buf, 'Y');
457 
458 	/* Open child's UTS namespace */
459 	char path[256];
460 	snprintf(path, sizeof(path), "/proc/%d/ns/uts", pid);
461 	fd_child_utsns = open(path, O_RDONLY);
462 	ASSERT_GE(fd_child_utsns, 0);
463 
464 	/* Get child's UTS namespace ID */
465 	ret = ioctl(fd_child_utsns, NS_GET_ID, &child_uts_ns_id);
466 	ASSERT_EQ(ret, 0);
467 	ASSERT_NE(child_uts_ns_id, 0);
468 
469 	/* Parent and child should have different UTS namespace IDs */
470 	ASSERT_NE(parent_uts_ns_id, child_uts_ns_id);
471 
472 	close(fd_parent_utsns);
473 	close(fd_child_utsns);
474 }
475 
476 TEST(nsid_userns_basic)
477 {
478 	__u64 user_ns_id = 0;
479 	int fd_userns;
480 	int ret;
481 
482 	/* Open the current user namespace */
483 	fd_userns = open("/proc/self/ns/user", O_RDONLY);
484 	ASSERT_GE(fd_userns, 0);
485 
486 	/* Get the user namespace ID */
487 	ret = ioctl(fd_userns, NS_GET_ID, &user_ns_id);
488 	ASSERT_EQ(ret, 0);
489 	ASSERT_NE(user_ns_id, 0);
490 
491 	/* Verify we can get the same ID again */
492 	__u64 user_ns_id2 = 0;
493 	ret = ioctl(fd_userns, NS_GET_ID, &user_ns_id2);
494 	ASSERT_EQ(ret, 0);
495 	ASSERT_EQ(user_ns_id, user_ns_id2);
496 
497 	close(fd_userns);
498 }
499 
500 TEST_F(nsid, userns_separate)
501 {
502 	__u64 parent_user_ns_id = 0;
503 	__u64 child_user_ns_id = 0;
504 	int fd_parent_userns, fd_child_userns;
505 	int ret;
506 	pid_t pid;
507 	int pipefd[2];
508 
509 	/* Get parent's user namespace ID */
510 	fd_parent_userns = open("/proc/self/ns/user", O_RDONLY);
511 	ASSERT_GE(fd_parent_userns, 0);
512 	ret = ioctl(fd_parent_userns, NS_GET_ID, &parent_user_ns_id);
513 	ASSERT_EQ(ret, 0);
514 	ASSERT_NE(parent_user_ns_id, 0);
515 
516 	/* Create a pipe for synchronization */
517 	ASSERT_EQ(pipe(pipefd), 0);
518 
519 	pid = fork();
520 	ASSERT_GE(pid, 0);
521 
522 	if (pid == 0) {
523 		/* Child process */
524 		close(pipefd[0]);
525 
526 		/* Create new user namespace */
527 		ret = unshare(CLONE_NEWUSER);
528 		if (ret != 0) {
529 			/* Skip test if we don't have permission */
530 			if (errno == EPERM || errno == EACCES) {
531 				write(pipefd[1], "S", 1); /* Signal skip */
532 				_exit(0);
533 			}
534 			_exit(1);
535 		}
536 
537 		/* Signal success */
538 		write(pipefd[1], "Y", 1);
539 		close(pipefd[1]);
540 
541 		/* Keep namespace alive */
542 		pause();
543 		_exit(0);
544 	}
545 
546 	/* Track child for cleanup */
547 	self->child_pid = pid;
548 
549 	/* Parent process */
550 	close(pipefd[1]);
551 
552 	char buf;
553 	ASSERT_EQ(read(pipefd[0], &buf, 1), 1);
554 	close(pipefd[0]);
555 
556 	if (buf == 'S') {
557 		/* Child couldn't create namespace, skip test */
558 		close(fd_parent_userns);
559 		SKIP(return, "No permission to create user namespace");
560 	}
561 
562 	ASSERT_EQ(buf, 'Y');
563 
564 	/* Open child's user namespace */
565 	char path[256];
566 	snprintf(path, sizeof(path), "/proc/%d/ns/user", pid);
567 	fd_child_userns = open(path, O_RDONLY);
568 	ASSERT_GE(fd_child_userns, 0);
569 
570 	/* Get child's user namespace ID */
571 	ret = ioctl(fd_child_userns, NS_GET_ID, &child_user_ns_id);
572 	ASSERT_EQ(ret, 0);
573 	ASSERT_NE(child_user_ns_id, 0);
574 
575 	/* Parent and child should have different user namespace IDs */
576 	ASSERT_NE(parent_user_ns_id, child_user_ns_id);
577 
578 	close(fd_parent_userns);
579 	close(fd_child_userns);
580 }
581 
582 TEST(nsid_timens_basic)
583 {
584 	__u64 time_ns_id = 0;
585 	int fd_timens;
586 	int ret;
587 
588 	/* Open the current time namespace */
589 	fd_timens = open("/proc/self/ns/time", O_RDONLY);
590 	if (fd_timens < 0) {
591 		SKIP(return, "Time namespaces not supported");
592 	}
593 
594 	/* Get the time namespace ID */
595 	ret = ioctl(fd_timens, NS_GET_ID, &time_ns_id);
596 	ASSERT_EQ(ret, 0);
597 	ASSERT_NE(time_ns_id, 0);
598 
599 	/* Verify we can get the same ID again */
600 	__u64 time_ns_id2 = 0;
601 	ret = ioctl(fd_timens, NS_GET_ID, &time_ns_id2);
602 	ASSERT_EQ(ret, 0);
603 	ASSERT_EQ(time_ns_id, time_ns_id2);
604 
605 	close(fd_timens);
606 }
607 
608 TEST_F(nsid, timens_separate)
609 {
610 	__u64 parent_time_ns_id = 0;
611 	__u64 child_time_ns_id = 0;
612 	int fd_parent_timens, fd_child_timens;
613 	int ret;
614 	pid_t pid;
615 	int pipefd[2];
616 
617 	/* Open the current time namespace */
618 	fd_parent_timens = open("/proc/self/ns/time", O_RDONLY);
619 	if (fd_parent_timens < 0) {
620 		SKIP(return, "Time namespaces not supported");
621 	}
622 
623 	/* Get parent's time namespace ID */
624 	ret = ioctl(fd_parent_timens, NS_GET_ID, &parent_time_ns_id);
625 	ASSERT_EQ(ret, 0);
626 	ASSERT_NE(parent_time_ns_id, 0);
627 
628 	/* Create a pipe for synchronization */
629 	ASSERT_EQ(pipe(pipefd), 0);
630 
631 	pid = fork();
632 	ASSERT_GE(pid, 0);
633 
634 	if (pid == 0) {
635 		/* Child process */
636 		close(pipefd[0]);
637 
638 		/* Create new time namespace */
639 		ret = unshare(CLONE_NEWTIME);
640 		if (ret != 0) {
641 			/* Skip test if we don't have permission */
642 			if (errno == EPERM || errno == EACCES || errno == EINVAL) {
643 				write(pipefd[1], "S", 1); /* Signal skip */
644 				_exit(0);
645 			}
646 			_exit(1);
647 		}
648 
649 		/* Fork a grandchild to actually enter the new namespace */
650 		pid_t grandchild = fork();
651 		if (grandchild == 0) {
652 			close(pipefd[1]);
653 			pause();
654 			_exit(0);
655 		} else if (grandchild > 0) {
656 			/* Child writes grandchild PID and waits */
657 			write(pipefd[1], "Y", 1);
658 			write(pipefd[1], &grandchild, sizeof(grandchild));
659 			close(pipefd[1]);
660 			pause(); /* Keep the parent alive to maintain the grandchild */
661 			_exit(0);
662 		} else {
663 			_exit(1);
664 		}
665 	}
666 
667 	/* Track child for cleanup */
668 	self->child_pid = pid;
669 
670 	/* Parent process */
671 	close(pipefd[1]);
672 
673 	char buf;
674 	ASSERT_EQ(read(pipefd[0], &buf, 1), 1);
675 
676 	if (buf == 'S') {
677 		/* Child couldn't create namespace, skip test */
678 		close(fd_parent_timens);
679 		close(pipefd[0]);
680 		SKIP(return, "Cannot create time namespace");
681 	}
682 
683 	ASSERT_EQ(buf, 'Y');
684 
685 	pid_t grandchild_pid;
686 	ASSERT_EQ(read(pipefd[0], &grandchild_pid, sizeof(grandchild_pid)), sizeof(grandchild_pid));
687 	self->grandchild_pid = grandchild_pid;
688 	close(pipefd[0]);
689 
690 	/* Open grandchild's time namespace */
691 	char path[256];
692 	snprintf(path, sizeof(path), "/proc/%d/ns/time", grandchild_pid);
693 	fd_child_timens = open(path, O_RDONLY);
694 	ASSERT_GE(fd_child_timens, 0);
695 
696 	/* Get child's time namespace ID */
697 	ret = ioctl(fd_child_timens, NS_GET_ID, &child_time_ns_id);
698 	ASSERT_EQ(ret, 0);
699 	ASSERT_NE(child_time_ns_id, 0);
700 
701 	/* Parent and child should have different time namespace IDs */
702 	ASSERT_NE(parent_time_ns_id, child_time_ns_id);
703 
704 	close(fd_parent_timens);
705 	close(fd_child_timens);
706 }
707 
708 TEST(nsid_pidns_basic)
709 {
710 	__u64 pid_ns_id = 0;
711 	int fd_pidns;
712 	int ret;
713 
714 	/* Open the current PID namespace */
715 	fd_pidns = open("/proc/self/ns/pid", O_RDONLY);
716 	ASSERT_GE(fd_pidns, 0);
717 
718 	/* Get the PID namespace ID */
719 	ret = ioctl(fd_pidns, NS_GET_ID, &pid_ns_id);
720 	ASSERT_EQ(ret, 0);
721 	ASSERT_NE(pid_ns_id, 0);
722 
723 	/* Verify we can get the same ID again */
724 	__u64 pid_ns_id2 = 0;
725 	ret = ioctl(fd_pidns, NS_GET_ID, &pid_ns_id2);
726 	ASSERT_EQ(ret, 0);
727 	ASSERT_EQ(pid_ns_id, pid_ns_id2);
728 
729 	close(fd_pidns);
730 }
731 
732 TEST_F(nsid, pidns_separate)
733 {
734 	__u64 parent_pid_ns_id = 0;
735 	__u64 child_pid_ns_id = 0;
736 	int fd_parent_pidns, fd_child_pidns;
737 	int ret;
738 	pid_t pid;
739 	int pipefd[2];
740 
741 	/* Get parent's PID namespace ID */
742 	fd_parent_pidns = open("/proc/self/ns/pid", O_RDONLY);
743 	ASSERT_GE(fd_parent_pidns, 0);
744 	ret = ioctl(fd_parent_pidns, NS_GET_ID, &parent_pid_ns_id);
745 	ASSERT_EQ(ret, 0);
746 	ASSERT_NE(parent_pid_ns_id, 0);
747 
748 	/* Create a pipe for synchronization */
749 	ASSERT_EQ(pipe(pipefd), 0);
750 
751 	pid = fork();
752 	ASSERT_GE(pid, 0);
753 
754 	if (pid == 0) {
755 		/* Child process */
756 		close(pipefd[0]);
757 
758 		/* Create new PID namespace */
759 		ret = unshare(CLONE_NEWPID);
760 		if (ret != 0) {
761 			/* Skip test if we don't have permission */
762 			if (errno == EPERM || errno == EACCES) {
763 				write(pipefd[1], "S", 1); /* Signal skip */
764 				_exit(0);
765 			}
766 			_exit(1);
767 		}
768 
769 		/* Fork a grandchild to actually enter the new namespace */
770 		pid_t grandchild = fork();
771 		if (grandchild == 0) {
772 			close(pipefd[1]);
773 			pause();
774 			_exit(0);
775 		} else if (grandchild > 0) {
776 			/* Child writes grandchild PID and waits */
777 			write(pipefd[1], "Y", 1);
778 			write(pipefd[1], &grandchild, sizeof(grandchild));
779 			close(pipefd[1]);
780 			pause(); /* Keep the parent alive to maintain the grandchild */
781 			_exit(0);
782 		} else {
783 			_exit(1);
784 		}
785 	}
786 
787 	/* Track child for cleanup */
788 	self->child_pid = pid;
789 
790 	/* Parent process */
791 	close(pipefd[1]);
792 
793 	char buf;
794 	ASSERT_EQ(read(pipefd[0], &buf, 1), 1);
795 
796 	if (buf == 'S') {
797 		/* Child couldn't create namespace, skip test */
798 		close(fd_parent_pidns);
799 		close(pipefd[0]);
800 		SKIP(return, "No permission to create PID namespace");
801 	}
802 
803 	ASSERT_EQ(buf, 'Y');
804 
805 	pid_t grandchild_pid;
806 	ASSERT_EQ(read(pipefd[0], &grandchild_pid, sizeof(grandchild_pid)), sizeof(grandchild_pid));
807 	self->grandchild_pid = grandchild_pid;
808 	close(pipefd[0]);
809 
810 	/* Open grandchild's PID namespace */
811 	char path[256];
812 	snprintf(path, sizeof(path), "/proc/%d/ns/pid", grandchild_pid);
813 	fd_child_pidns = open(path, O_RDONLY);
814 	ASSERT_GE(fd_child_pidns, 0);
815 
816 	/* Get child's PID namespace ID */
817 	ret = ioctl(fd_child_pidns, NS_GET_ID, &child_pid_ns_id);
818 	ASSERT_EQ(ret, 0);
819 	ASSERT_NE(child_pid_ns_id, 0);
820 
821 	/* Parent and child should have different PID namespace IDs */
822 	ASSERT_NE(parent_pid_ns_id, child_pid_ns_id);
823 
824 	close(fd_parent_pidns);
825 	close(fd_child_pidns);
826 }
827 
828 TEST(nsid_netns_basic)
829 {
830 	__u64 net_ns_id = 0;
831 	__u64 netns_cookie = 0;
832 	int fd_netns;
833 	int sock;
834 	socklen_t optlen;
835 	int ret;
836 
837 	/* Open the current network namespace */
838 	fd_netns = open("/proc/self/ns/net", O_RDONLY);
839 	ASSERT_GE(fd_netns, 0);
840 
841 	/* Get the network namespace ID via ioctl */
842 	ret = ioctl(fd_netns, NS_GET_ID, &net_ns_id);
843 	ASSERT_EQ(ret, 0);
844 	ASSERT_NE(net_ns_id, 0);
845 
846 	/* Create a socket to get the SO_NETNS_COOKIE */
847 	sock = socket(AF_UNIX, SOCK_STREAM, 0);
848 	ASSERT_GE(sock, 0);
849 
850 	/* Get the network namespace cookie via socket option */
851 	optlen = sizeof(netns_cookie);
852 	ret = getsockopt(sock, SOL_SOCKET, SO_NETNS_COOKIE, &netns_cookie, &optlen);
853 	ASSERT_EQ(ret, 0);
854 	ASSERT_EQ(optlen, sizeof(netns_cookie));
855 
856 	/* The namespace ID and cookie should be identical */
857 	ASSERT_EQ(net_ns_id, netns_cookie);
858 
859 	/* Verify we can get the same ID again */
860 	__u64 net_ns_id2 = 0;
861 	ret = ioctl(fd_netns, NS_GET_ID, &net_ns_id2);
862 	ASSERT_EQ(ret, 0);
863 	ASSERT_EQ(net_ns_id, net_ns_id2);
864 
865 	close(sock);
866 	close(fd_netns);
867 }
868 
869 TEST_F(nsid, netns_separate)
870 {
871 	__u64 parent_net_ns_id = 0;
872 	__u64 parent_netns_cookie = 0;
873 	__u64 child_net_ns_id = 0;
874 	__u64 child_netns_cookie = 0;
875 	int fd_parent_netns, fd_child_netns;
876 	int parent_sock, child_sock;
877 	socklen_t optlen;
878 	int ret;
879 	pid_t pid;
880 	int pipefd[2];
881 
882 	/* Get parent's network namespace ID */
883 	fd_parent_netns = open("/proc/self/ns/net", O_RDONLY);
884 	ASSERT_GE(fd_parent_netns, 0);
885 	ret = ioctl(fd_parent_netns, NS_GET_ID, &parent_net_ns_id);
886 	ASSERT_EQ(ret, 0);
887 	ASSERT_NE(parent_net_ns_id, 0);
888 
889 	/* Get parent's network namespace cookie */
890 	parent_sock = socket(AF_UNIX, SOCK_STREAM, 0);
891 	ASSERT_GE(parent_sock, 0);
892 	optlen = sizeof(parent_netns_cookie);
893 	ret = getsockopt(parent_sock, SOL_SOCKET, SO_NETNS_COOKIE, &parent_netns_cookie, &optlen);
894 	ASSERT_EQ(ret, 0);
895 
896 	/* Verify parent's ID and cookie match */
897 	ASSERT_EQ(parent_net_ns_id, parent_netns_cookie);
898 
899 	/* Create a pipe for synchronization */
900 	ASSERT_EQ(pipe(pipefd), 0);
901 
902 	pid = fork();
903 	ASSERT_GE(pid, 0);
904 
905 	if (pid == 0) {
906 		/* Child process */
907 		close(pipefd[0]);
908 
909 		/* Create new network namespace */
910 		ret = unshare(CLONE_NEWNET);
911 		if (ret != 0) {
912 			/* Skip test if we don't have permission */
913 			if (errno == EPERM || errno == EACCES) {
914 				write(pipefd[1], "S", 1); /* Signal skip */
915 				_exit(0);
916 			}
917 			_exit(1);
918 		}
919 
920 		/* Signal success */
921 		write(pipefd[1], "Y", 1);
922 		close(pipefd[1]);
923 
924 		/* Keep namespace alive */
925 		pause();
926 		_exit(0);
927 	}
928 
929 	/* Track child for cleanup */
930 	self->child_pid = pid;
931 
932 	/* Parent process */
933 	close(pipefd[1]);
934 
935 	char buf;
936 	ASSERT_EQ(read(pipefd[0], &buf, 1), 1);
937 	close(pipefd[0]);
938 
939 	if (buf == 'S') {
940 		/* Child couldn't create namespace, skip test */
941 		close(fd_parent_netns);
942 		close(parent_sock);
943 		SKIP(return, "No permission to create network namespace");
944 	}
945 
946 	ASSERT_EQ(buf, 'Y');
947 
948 	/* Open child's network namespace */
949 	char path[256];
950 	snprintf(path, sizeof(path), "/proc/%d/ns/net", pid);
951 	fd_child_netns = open(path, O_RDONLY);
952 	ASSERT_GE(fd_child_netns, 0);
953 
954 	/* Get child's network namespace ID */
955 	ret = ioctl(fd_child_netns, NS_GET_ID, &child_net_ns_id);
956 	ASSERT_EQ(ret, 0);
957 	ASSERT_NE(child_net_ns_id, 0);
958 
959 	/* Create socket in child's namespace to get cookie */
960 	ret = setns(fd_child_netns, CLONE_NEWNET);
961 	if (ret == 0) {
962 		child_sock = socket(AF_UNIX, SOCK_STREAM, 0);
963 		ASSERT_GE(child_sock, 0);
964 
965 		optlen = sizeof(child_netns_cookie);
966 		ret = getsockopt(child_sock, SOL_SOCKET, SO_NETNS_COOKIE, &child_netns_cookie, &optlen);
967 		ASSERT_EQ(ret, 0);
968 
969 		/* Verify child's ID and cookie match */
970 		ASSERT_EQ(child_net_ns_id, child_netns_cookie);
971 
972 		close(child_sock);
973 
974 		/* Return to parent namespace */
975 		setns(fd_parent_netns, CLONE_NEWNET);
976 	}
977 
978 	/* Parent and child should have different network namespace IDs */
979 	ASSERT_NE(parent_net_ns_id, child_net_ns_id);
980 	if (child_netns_cookie != 0) {
981 		ASSERT_NE(parent_netns_cookie, child_netns_cookie);
982 	}
983 
984 	close(fd_parent_netns);
985 	close(fd_child_netns);
986 	close(parent_sock);
987 }
988 
989 TEST_HARNESS_MAIN
990