1 // SPDX-License-Identifier: GPL-2.0-only
2 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
3
4 #include <linux/workqueue.h>
5 #include <linux/rtnetlink.h>
6 #include <linux/cache.h>
7 #include <linux/slab.h>
8 #include <linux/list.h>
9 #include <linux/delay.h>
10 #include <linux/sched.h>
11 #include <linux/idr.h>
12 #include <linux/rculist.h>
13 #include <linux/nsproxy.h>
14 #include <linux/fs.h>
15 #include <linux/proc_ns.h>
16 #include <linux/file.h>
17 #include <linux/export.h>
18 #include <linux/user_namespace.h>
19 #include <linux/net_namespace.h>
20 #include <linux/sched/task.h>
21 #include <linux/uidgid.h>
22 #include <linux/cookie.h>
23
24 #include <net/sock.h>
25 #include <net/netlink.h>
26 #include <net/net_namespace.h>
27 #include <net/netns/generic.h>
28
29 /*
30 * Our network namespace constructor/destructor lists
31 */
32
33 static LIST_HEAD(pernet_list);
34 static struct list_head *first_device = &pernet_list;
35
36 LIST_HEAD(net_namespace_list);
37 EXPORT_SYMBOL_GPL(net_namespace_list);
38
39 /* Protects net_namespace_list. Nests iside rtnl_lock() */
40 DECLARE_RWSEM(net_rwsem);
41 EXPORT_SYMBOL_GPL(net_rwsem);
42
43 #ifdef CONFIG_KEYS
44 static struct key_tag init_net_key_domain = { .usage = REFCOUNT_INIT(1) };
45 #endif
46
47 struct net init_net;
48 EXPORT_SYMBOL(init_net);
49
50 static bool init_net_initialized;
51 /*
52 * pernet_ops_rwsem: protects: pernet_list, net_generic_ids,
53 * init_net_initialized and first_device pointer.
54 * This is internal net namespace object. Please, don't use it
55 * outside.
56 */
57 DECLARE_RWSEM(pernet_ops_rwsem);
58 EXPORT_SYMBOL_GPL(pernet_ops_rwsem);
59
60 #define MIN_PERNET_OPS_ID \
61 ((sizeof(struct net_generic) + sizeof(void *) - 1) / sizeof(void *))
62
63 #define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */
64
65 static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS;
66
67 DEFINE_COOKIE(net_cookie);
68
net_alloc_generic(void)69 static struct net_generic *net_alloc_generic(void)
70 {
71 struct net_generic *ng;
72 unsigned int generic_size = offsetof(struct net_generic, ptr[max_gen_ptrs]);
73
74 ng = kzalloc(generic_size, GFP_KERNEL);
75 if (ng)
76 ng->s.len = max_gen_ptrs;
77
78 return ng;
79 }
80
net_assign_generic(struct net * net,unsigned int id,void * data)81 static int net_assign_generic(struct net *net, unsigned int id, void *data)
82 {
83 struct net_generic *ng, *old_ng;
84
85 BUG_ON(id < MIN_PERNET_OPS_ID);
86
87 old_ng = rcu_dereference_protected(net->gen,
88 lockdep_is_held(&pernet_ops_rwsem));
89 if (old_ng->s.len > id) {
90 old_ng->ptr[id] = data;
91 return 0;
92 }
93
94 ng = net_alloc_generic();
95 if (!ng)
96 return -ENOMEM;
97
98 /*
99 * Some synchronisation notes:
100 *
101 * The net_generic explores the net->gen array inside rcu
102 * read section. Besides once set the net->gen->ptr[x]
103 * pointer never changes (see rules in netns/generic.h).
104 *
105 * That said, we simply duplicate this array and schedule
106 * the old copy for kfree after a grace period.
107 */
108
109 memcpy(&ng->ptr[MIN_PERNET_OPS_ID], &old_ng->ptr[MIN_PERNET_OPS_ID],
110 (old_ng->s.len - MIN_PERNET_OPS_ID) * sizeof(void *));
111 ng->ptr[id] = data;
112
113 rcu_assign_pointer(net->gen, ng);
114 kfree_rcu(old_ng, s.rcu);
115 return 0;
116 }
117
ops_init(const struct pernet_operations * ops,struct net * net)118 static int ops_init(const struct pernet_operations *ops, struct net *net)
119 {
120 struct net_generic *ng;
121 int err = -ENOMEM;
122 void *data = NULL;
123
124 if (ops->id && ops->size) {
125 data = kzalloc(ops->size, GFP_KERNEL);
126 if (!data)
127 goto out;
128
129 err = net_assign_generic(net, *ops->id, data);
130 if (err)
131 goto cleanup;
132 }
133 err = 0;
134 if (ops->init)
135 err = ops->init(net);
136 if (!err)
137 return 0;
138
139 if (ops->id && ops->size) {
140 ng = rcu_dereference_protected(net->gen,
141 lockdep_is_held(&pernet_ops_rwsem));
142 ng->ptr[*ops->id] = NULL;
143 }
144
145 cleanup:
146 kfree(data);
147
148 out:
149 return err;
150 }
151
ops_pre_exit_list(const struct pernet_operations * ops,struct list_head * net_exit_list)152 static void ops_pre_exit_list(const struct pernet_operations *ops,
153 struct list_head *net_exit_list)
154 {
155 struct net *net;
156
157 if (ops->pre_exit) {
158 list_for_each_entry(net, net_exit_list, exit_list)
159 ops->pre_exit(net);
160 }
161 }
162
ops_exit_list(const struct pernet_operations * ops,struct list_head * net_exit_list)163 static void ops_exit_list(const struct pernet_operations *ops,
164 struct list_head *net_exit_list)
165 {
166 struct net *net;
167 if (ops->exit) {
168 list_for_each_entry(net, net_exit_list, exit_list) {
169 ops->exit(net);
170 cond_resched();
171 }
172 }
173 if (ops->exit_batch)
174 ops->exit_batch(net_exit_list);
175 }
176
ops_free_list(const struct pernet_operations * ops,struct list_head * net_exit_list)177 static void ops_free_list(const struct pernet_operations *ops,
178 struct list_head *net_exit_list)
179 {
180 struct net *net;
181 if (ops->size && ops->id) {
182 list_for_each_entry(net, net_exit_list, exit_list)
183 kfree(net_generic(net, *ops->id));
184 }
185 }
186
187 /* should be called with nsid_lock held */
alloc_netid(struct net * net,struct net * peer,int reqid)188 static int alloc_netid(struct net *net, struct net *peer, int reqid)
189 {
190 int min = 0, max = 0;
191
192 if (reqid >= 0) {
193 min = reqid;
194 max = reqid + 1;
195 }
196
197 return idr_alloc(&net->netns_ids, peer, min, max, GFP_ATOMIC);
198 }
199
200 /* This function is used by idr_for_each(). If net is equal to peer, the
201 * function returns the id so that idr_for_each() stops. Because we cannot
202 * returns the id 0 (idr_for_each() will not stop), we return the magic value
203 * NET_ID_ZERO (-1) for it.
204 */
205 #define NET_ID_ZERO -1
net_eq_idr(int id,void * net,void * peer)206 static int net_eq_idr(int id, void *net, void *peer)
207 {
208 if (net_eq(net, peer))
209 return id ? : NET_ID_ZERO;
210 return 0;
211 }
212
213 /* Must be called from RCU-critical section or with nsid_lock held */
__peernet2id(const struct net * net,struct net * peer)214 static int __peernet2id(const struct net *net, struct net *peer)
215 {
216 int id = idr_for_each(&net->netns_ids, net_eq_idr, peer);
217
218 /* Magic value for id 0. */
219 if (id == NET_ID_ZERO)
220 return 0;
221 if (id > 0)
222 return id;
223
224 return NETNSA_NSID_NOT_ASSIGNED;
225 }
226
227 static void rtnl_net_notifyid(struct net *net, int cmd, int id, u32 portid,
228 struct nlmsghdr *nlh, gfp_t gfp);
229 /* This function returns the id of a peer netns. If no id is assigned, one will
230 * be allocated and returned.
231 */
peernet2id_alloc(struct net * net,struct net * peer,gfp_t gfp)232 int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp)
233 {
234 int id;
235
236 if (refcount_read(&net->ns.count) == 0)
237 return NETNSA_NSID_NOT_ASSIGNED;
238
239 spin_lock_bh(&net->nsid_lock);
240 id = __peernet2id(net, peer);
241 if (id >= 0) {
242 spin_unlock_bh(&net->nsid_lock);
243 return id;
244 }
245
246 /* When peer is obtained from RCU lists, we may race with
247 * its cleanup. Check whether it's alive, and this guarantees
248 * we never hash a peer back to net->netns_ids, after it has
249 * just been idr_remove()'d from there in cleanup_net().
250 */
251 if (!maybe_get_net(peer)) {
252 spin_unlock_bh(&net->nsid_lock);
253 return NETNSA_NSID_NOT_ASSIGNED;
254 }
255
256 id = alloc_netid(net, peer, -1);
257 spin_unlock_bh(&net->nsid_lock);
258
259 put_net(peer);
260 if (id < 0)
261 return NETNSA_NSID_NOT_ASSIGNED;
262
263 rtnl_net_notifyid(net, RTM_NEWNSID, id, 0, NULL, gfp);
264
265 return id;
266 }
267 EXPORT_SYMBOL_GPL(peernet2id_alloc);
268
269 /* This function returns, if assigned, the id of a peer netns. */
peernet2id(const struct net * net,struct net * peer)270 int peernet2id(const struct net *net, struct net *peer)
271 {
272 int id;
273
274 rcu_read_lock();
275 id = __peernet2id(net, peer);
276 rcu_read_unlock();
277
278 return id;
279 }
280 EXPORT_SYMBOL(peernet2id);
281
282 /* This function returns true is the peer netns has an id assigned into the
283 * current netns.
284 */
peernet_has_id(const struct net * net,struct net * peer)285 bool peernet_has_id(const struct net *net, struct net *peer)
286 {
287 return peernet2id(net, peer) >= 0;
288 }
289
get_net_ns_by_id(const struct net * net,int id)290 struct net *get_net_ns_by_id(const struct net *net, int id)
291 {
292 struct net *peer;
293
294 if (id < 0)
295 return NULL;
296
297 rcu_read_lock();
298 peer = idr_find(&net->netns_ids, id);
299 if (peer)
300 peer = maybe_get_net(peer);
301 rcu_read_unlock();
302
303 return peer;
304 }
305 EXPORT_SYMBOL_GPL(get_net_ns_by_id);
306
307 /*
308 * setup_net runs the initializers for the network namespace object.
309 */
setup_net(struct net * net,struct user_namespace * user_ns)310 static __net_init int setup_net(struct net *net, struct user_namespace *user_ns)
311 {
312 /* Must be called with pernet_ops_rwsem held */
313 const struct pernet_operations *ops, *saved_ops;
314 int error = 0;
315 LIST_HEAD(net_exit_list);
316
317 refcount_set(&net->ns.count, 1);
318 ref_tracker_dir_init(&net->refcnt_tracker, 128);
319
320 refcount_set(&net->passive, 1);
321 get_random_bytes(&net->hash_mix, sizeof(u32));
322 preempt_disable();
323 net->net_cookie = gen_cookie_next(&net_cookie);
324 preempt_enable();
325 net->dev_base_seq = 1;
326 net->user_ns = user_ns;
327 idr_init(&net->netns_ids);
328 spin_lock_init(&net->nsid_lock);
329 mutex_init(&net->ipv4.ra_mutex);
330
331 list_for_each_entry(ops, &pernet_list, list) {
332 error = ops_init(ops, net);
333 if (error < 0)
334 goto out_undo;
335 }
336 down_write(&net_rwsem);
337 list_add_tail_rcu(&net->list, &net_namespace_list);
338 up_write(&net_rwsem);
339 out:
340 return error;
341
342 out_undo:
343 /* Walk through the list backwards calling the exit functions
344 * for the pernet modules whose init functions did not fail.
345 */
346 list_add(&net->exit_list, &net_exit_list);
347 saved_ops = ops;
348 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
349 ops_pre_exit_list(ops, &net_exit_list);
350
351 synchronize_rcu();
352
353 ops = saved_ops;
354 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
355 ops_exit_list(ops, &net_exit_list);
356
357 ops = saved_ops;
358 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
359 ops_free_list(ops, &net_exit_list);
360
361 rcu_barrier();
362 goto out;
363 }
364
net_defaults_init_net(struct net * net)365 static int __net_init net_defaults_init_net(struct net *net)
366 {
367 net->core.sysctl_somaxconn = SOMAXCONN;
368 net->core.sysctl_txrehash = SOCK_TXREHASH_ENABLED;
369
370 return 0;
371 }
372
373 static struct pernet_operations net_defaults_ops = {
374 .init = net_defaults_init_net,
375 };
376
net_defaults_init(void)377 static __init int net_defaults_init(void)
378 {
379 if (register_pernet_subsys(&net_defaults_ops))
380 panic("Cannot initialize net default settings");
381
382 return 0;
383 }
384
385 core_initcall(net_defaults_init);
386
387 #ifdef CONFIG_NET_NS
inc_net_namespaces(struct user_namespace * ns)388 static struct ucounts *inc_net_namespaces(struct user_namespace *ns)
389 {
390 return inc_ucount(ns, current_euid(), UCOUNT_NET_NAMESPACES);
391 }
392
dec_net_namespaces(struct ucounts * ucounts)393 static void dec_net_namespaces(struct ucounts *ucounts)
394 {
395 dec_ucount(ucounts, UCOUNT_NET_NAMESPACES);
396 }
397
398 static struct kmem_cache *net_cachep __ro_after_init;
399 static struct workqueue_struct *netns_wq;
400
net_alloc(void)401 static struct net *net_alloc(void)
402 {
403 struct net *net = NULL;
404 struct net_generic *ng;
405
406 ng = net_alloc_generic();
407 if (!ng)
408 goto out;
409
410 net = kmem_cache_zalloc(net_cachep, GFP_KERNEL);
411 if (!net)
412 goto out_free;
413
414 #ifdef CONFIG_KEYS
415 net->key_domain = kzalloc(sizeof(struct key_tag), GFP_KERNEL);
416 if (!net->key_domain)
417 goto out_free_2;
418 refcount_set(&net->key_domain->usage, 1);
419 #endif
420
421 rcu_assign_pointer(net->gen, ng);
422 out:
423 return net;
424
425 #ifdef CONFIG_KEYS
426 out_free_2:
427 kmem_cache_free(net_cachep, net);
428 net = NULL;
429 #endif
430 out_free:
431 kfree(ng);
432 goto out;
433 }
434
net_free(struct net * net)435 static void net_free(struct net *net)
436 {
437 if (refcount_dec_and_test(&net->passive)) {
438 kfree(rcu_access_pointer(net->gen));
439 kmem_cache_free(net_cachep, net);
440 }
441 }
442
net_drop_ns(void * p)443 void net_drop_ns(void *p)
444 {
445 struct net *net = (struct net *)p;
446
447 if (net)
448 net_free(net);
449 }
450
copy_net_ns(unsigned long flags,struct user_namespace * user_ns,struct net * old_net)451 struct net *copy_net_ns(unsigned long flags,
452 struct user_namespace *user_ns, struct net *old_net)
453 {
454 struct ucounts *ucounts;
455 struct net *net;
456 int rv;
457
458 if (!(flags & CLONE_NEWNET))
459 return get_net(old_net);
460
461 ucounts = inc_net_namespaces(user_ns);
462 if (!ucounts)
463 return ERR_PTR(-ENOSPC);
464
465 net = net_alloc();
466 if (!net) {
467 rv = -ENOMEM;
468 goto dec_ucounts;
469 }
470 refcount_set(&net->passive, 1);
471 net->ucounts = ucounts;
472 get_user_ns(user_ns);
473
474 rv = down_read_killable(&pernet_ops_rwsem);
475 if (rv < 0)
476 goto put_userns;
477
478 rv = setup_net(net, user_ns);
479
480 up_read(&pernet_ops_rwsem);
481
482 if (rv < 0) {
483 put_userns:
484 #ifdef CONFIG_KEYS
485 key_remove_domain(net->key_domain);
486 #endif
487 put_user_ns(user_ns);
488 net_free(net);
489 dec_ucounts:
490 dec_net_namespaces(ucounts);
491 return ERR_PTR(rv);
492 }
493 return net;
494 }
495
496 /**
497 * net_ns_get_ownership - get sysfs ownership data for @net
498 * @net: network namespace in question (can be NULL)
499 * @uid: kernel user ID for sysfs objects
500 * @gid: kernel group ID for sysfs objects
501 *
502 * Returns the uid/gid pair of root in the user namespace associated with the
503 * given network namespace.
504 */
net_ns_get_ownership(const struct net * net,kuid_t * uid,kgid_t * gid)505 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid)
506 {
507 if (net) {
508 kuid_t ns_root_uid = make_kuid(net->user_ns, 0);
509 kgid_t ns_root_gid = make_kgid(net->user_ns, 0);
510
511 if (uid_valid(ns_root_uid))
512 *uid = ns_root_uid;
513
514 if (gid_valid(ns_root_gid))
515 *gid = ns_root_gid;
516 } else {
517 *uid = GLOBAL_ROOT_UID;
518 *gid = GLOBAL_ROOT_GID;
519 }
520 }
521 EXPORT_SYMBOL_GPL(net_ns_get_ownership);
522
unhash_nsid(struct net * net,struct net * last)523 static void unhash_nsid(struct net *net, struct net *last)
524 {
525 struct net *tmp;
526 /* This function is only called from cleanup_net() work,
527 * and this work is the only process, that may delete
528 * a net from net_namespace_list. So, when the below
529 * is executing, the list may only grow. Thus, we do not
530 * use for_each_net_rcu() or net_rwsem.
531 */
532 for_each_net(tmp) {
533 int id;
534
535 spin_lock_bh(&tmp->nsid_lock);
536 id = __peernet2id(tmp, net);
537 if (id >= 0)
538 idr_remove(&tmp->netns_ids, id);
539 spin_unlock_bh(&tmp->nsid_lock);
540 if (id >= 0)
541 rtnl_net_notifyid(tmp, RTM_DELNSID, id, 0, NULL,
542 GFP_KERNEL);
543 if (tmp == last)
544 break;
545 }
546 spin_lock_bh(&net->nsid_lock);
547 idr_destroy(&net->netns_ids);
548 spin_unlock_bh(&net->nsid_lock);
549 }
550
551 static LLIST_HEAD(cleanup_list);
552
cleanup_net(struct work_struct * work)553 static void cleanup_net(struct work_struct *work)
554 {
555 const struct pernet_operations *ops;
556 struct net *net, *tmp, *last;
557 struct llist_node *net_kill_list;
558 LIST_HEAD(net_exit_list);
559
560 /* Atomically snapshot the list of namespaces to cleanup */
561 net_kill_list = llist_del_all(&cleanup_list);
562
563 down_read(&pernet_ops_rwsem);
564
565 /* Don't let anyone else find us. */
566 down_write(&net_rwsem);
567 llist_for_each_entry(net, net_kill_list, cleanup_list)
568 list_del_rcu(&net->list);
569 /* Cache last net. After we unlock rtnl, no one new net
570 * added to net_namespace_list can assign nsid pointer
571 * to a net from net_kill_list (see peernet2id_alloc()).
572 * So, we skip them in unhash_nsid().
573 *
574 * Note, that unhash_nsid() does not delete nsid links
575 * between net_kill_list's nets, as they've already
576 * deleted from net_namespace_list. But, this would be
577 * useless anyway, as netns_ids are destroyed there.
578 */
579 last = list_last_entry(&net_namespace_list, struct net, list);
580 up_write(&net_rwsem);
581
582 llist_for_each_entry(net, net_kill_list, cleanup_list) {
583 unhash_nsid(net, last);
584 list_add_tail(&net->exit_list, &net_exit_list);
585 }
586
587 /* Run all of the network namespace pre_exit methods */
588 list_for_each_entry_reverse(ops, &pernet_list, list)
589 ops_pre_exit_list(ops, &net_exit_list);
590
591 /*
592 * Another CPU might be rcu-iterating the list, wait for it.
593 * This needs to be before calling the exit() notifiers, so
594 * the rcu_barrier() below isn't sufficient alone.
595 * Also the pre_exit() and exit() methods need this barrier.
596 */
597 synchronize_rcu();
598
599 /* Run all of the network namespace exit methods */
600 list_for_each_entry_reverse(ops, &pernet_list, list)
601 ops_exit_list(ops, &net_exit_list);
602
603 /* Free the net generic variables */
604 list_for_each_entry_reverse(ops, &pernet_list, list)
605 ops_free_list(ops, &net_exit_list);
606
607 up_read(&pernet_ops_rwsem);
608
609 /* Ensure there are no outstanding rcu callbacks using this
610 * network namespace.
611 */
612 rcu_barrier();
613
614 /* Finally it is safe to free my network namespace structure */
615 list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
616 list_del_init(&net->exit_list);
617 dec_net_namespaces(net->ucounts);
618 #ifdef CONFIG_KEYS
619 key_remove_domain(net->key_domain);
620 #endif
621 put_user_ns(net->user_ns);
622 net_free(net);
623 }
624 }
625
626 /**
627 * net_ns_barrier - wait until concurrent net_cleanup_work is done
628 *
629 * cleanup_net runs from work queue and will first remove namespaces
630 * from the global list, then run net exit functions.
631 *
632 * Call this in module exit path to make sure that all netns
633 * ->exit ops have been invoked before the function is removed.
634 */
net_ns_barrier(void)635 void net_ns_barrier(void)
636 {
637 down_write(&pernet_ops_rwsem);
638 up_write(&pernet_ops_rwsem);
639 }
640 EXPORT_SYMBOL(net_ns_barrier);
641
642 static DECLARE_WORK(net_cleanup_work, cleanup_net);
643
__put_net(struct net * net)644 void __put_net(struct net *net)
645 {
646 ref_tracker_dir_exit(&net->refcnt_tracker);
647 /* Cleanup the network namespace in process context */
648 if (llist_add(&net->cleanup_list, &cleanup_list))
649 queue_work(netns_wq, &net_cleanup_work);
650 }
651 EXPORT_SYMBOL_GPL(__put_net);
652
653 /**
654 * get_net_ns - increment the refcount of the network namespace
655 * @ns: common namespace (net)
656 *
657 * Returns the net's common namespace.
658 */
get_net_ns(struct ns_common * ns)659 struct ns_common *get_net_ns(struct ns_common *ns)
660 {
661 return &get_net(container_of(ns, struct net, ns))->ns;
662 }
663 EXPORT_SYMBOL_GPL(get_net_ns);
664
get_net_ns_by_fd(int fd)665 struct net *get_net_ns_by_fd(int fd)
666 {
667 struct file *file;
668 struct ns_common *ns;
669 struct net *net;
670
671 file = proc_ns_fget(fd);
672 if (IS_ERR(file))
673 return ERR_CAST(file);
674
675 ns = get_proc_ns(file_inode(file));
676 if (ns->ops == &netns_operations)
677 net = get_net(container_of(ns, struct net, ns));
678 else
679 net = ERR_PTR(-EINVAL);
680
681 fput(file);
682 return net;
683 }
684 EXPORT_SYMBOL_GPL(get_net_ns_by_fd);
685 #endif
686
get_net_ns_by_pid(pid_t pid)687 struct net *get_net_ns_by_pid(pid_t pid)
688 {
689 struct task_struct *tsk;
690 struct net *net;
691
692 /* Lookup the network namespace */
693 net = ERR_PTR(-ESRCH);
694 rcu_read_lock();
695 tsk = find_task_by_vpid(pid);
696 if (tsk) {
697 struct nsproxy *nsproxy;
698 task_lock(tsk);
699 nsproxy = tsk->nsproxy;
700 if (nsproxy)
701 net = get_net(nsproxy->net_ns);
702 task_unlock(tsk);
703 }
704 rcu_read_unlock();
705 return net;
706 }
707 EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
708
net_ns_net_init(struct net * net)709 static __net_init int net_ns_net_init(struct net *net)
710 {
711 #ifdef CONFIG_NET_NS
712 net->ns.ops = &netns_operations;
713 #endif
714 return ns_alloc_inum(&net->ns);
715 }
716
net_ns_net_exit(struct net * net)717 static __net_exit void net_ns_net_exit(struct net *net)
718 {
719 ns_free_inum(&net->ns);
720 }
721
722 static struct pernet_operations __net_initdata net_ns_ops = {
723 .init = net_ns_net_init,
724 .exit = net_ns_net_exit,
725 };
726
727 static const struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = {
728 [NETNSA_NONE] = { .type = NLA_UNSPEC },
729 [NETNSA_NSID] = { .type = NLA_S32 },
730 [NETNSA_PID] = { .type = NLA_U32 },
731 [NETNSA_FD] = { .type = NLA_U32 },
732 [NETNSA_TARGET_NSID] = { .type = NLA_S32 },
733 };
734
rtnl_net_newid(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)735 static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh,
736 struct netlink_ext_ack *extack)
737 {
738 struct net *net = sock_net(skb->sk);
739 struct nlattr *tb[NETNSA_MAX + 1];
740 struct nlattr *nla;
741 struct net *peer;
742 int nsid, err;
743
744 err = nlmsg_parse_deprecated(nlh, sizeof(struct rtgenmsg), tb,
745 NETNSA_MAX, rtnl_net_policy, extack);
746 if (err < 0)
747 return err;
748 if (!tb[NETNSA_NSID]) {
749 NL_SET_ERR_MSG(extack, "nsid is missing");
750 return -EINVAL;
751 }
752 nsid = nla_get_s32(tb[NETNSA_NSID]);
753
754 if (tb[NETNSA_PID]) {
755 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
756 nla = tb[NETNSA_PID];
757 } else if (tb[NETNSA_FD]) {
758 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
759 nla = tb[NETNSA_FD];
760 } else {
761 NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
762 return -EINVAL;
763 }
764 if (IS_ERR(peer)) {
765 NL_SET_BAD_ATTR(extack, nla);
766 NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
767 return PTR_ERR(peer);
768 }
769
770 spin_lock_bh(&net->nsid_lock);
771 if (__peernet2id(net, peer) >= 0) {
772 spin_unlock_bh(&net->nsid_lock);
773 err = -EEXIST;
774 NL_SET_BAD_ATTR(extack, nla);
775 NL_SET_ERR_MSG(extack,
776 "Peer netns already has a nsid assigned");
777 goto out;
778 }
779
780 err = alloc_netid(net, peer, nsid);
781 spin_unlock_bh(&net->nsid_lock);
782 if (err >= 0) {
783 rtnl_net_notifyid(net, RTM_NEWNSID, err, NETLINK_CB(skb).portid,
784 nlh, GFP_KERNEL);
785 err = 0;
786 } else if (err == -ENOSPC && nsid >= 0) {
787 err = -EEXIST;
788 NL_SET_BAD_ATTR(extack, tb[NETNSA_NSID]);
789 NL_SET_ERR_MSG(extack, "The specified nsid is already used");
790 }
791 out:
792 put_net(peer);
793 return err;
794 }
795
rtnl_net_get_size(void)796 static int rtnl_net_get_size(void)
797 {
798 return NLMSG_ALIGN(sizeof(struct rtgenmsg))
799 + nla_total_size(sizeof(s32)) /* NETNSA_NSID */
800 + nla_total_size(sizeof(s32)) /* NETNSA_CURRENT_NSID */
801 ;
802 }
803
804 struct net_fill_args {
805 u32 portid;
806 u32 seq;
807 int flags;
808 int cmd;
809 int nsid;
810 bool add_ref;
811 int ref_nsid;
812 };
813
rtnl_net_fill(struct sk_buff * skb,struct net_fill_args * args)814 static int rtnl_net_fill(struct sk_buff *skb, struct net_fill_args *args)
815 {
816 struct nlmsghdr *nlh;
817 struct rtgenmsg *rth;
818
819 nlh = nlmsg_put(skb, args->portid, args->seq, args->cmd, sizeof(*rth),
820 args->flags);
821 if (!nlh)
822 return -EMSGSIZE;
823
824 rth = nlmsg_data(nlh);
825 rth->rtgen_family = AF_UNSPEC;
826
827 if (nla_put_s32(skb, NETNSA_NSID, args->nsid))
828 goto nla_put_failure;
829
830 if (args->add_ref &&
831 nla_put_s32(skb, NETNSA_CURRENT_NSID, args->ref_nsid))
832 goto nla_put_failure;
833
834 nlmsg_end(skb, nlh);
835 return 0;
836
837 nla_put_failure:
838 nlmsg_cancel(skb, nlh);
839 return -EMSGSIZE;
840 }
841
rtnl_net_valid_getid_req(struct sk_buff * skb,const struct nlmsghdr * nlh,struct nlattr ** tb,struct netlink_ext_ack * extack)842 static int rtnl_net_valid_getid_req(struct sk_buff *skb,
843 const struct nlmsghdr *nlh,
844 struct nlattr **tb,
845 struct netlink_ext_ack *extack)
846 {
847 int i, err;
848
849 if (!netlink_strict_get_check(skb))
850 return nlmsg_parse_deprecated(nlh, sizeof(struct rtgenmsg),
851 tb, NETNSA_MAX, rtnl_net_policy,
852 extack);
853
854 err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct rtgenmsg), tb,
855 NETNSA_MAX, rtnl_net_policy,
856 extack);
857 if (err)
858 return err;
859
860 for (i = 0; i <= NETNSA_MAX; i++) {
861 if (!tb[i])
862 continue;
863
864 switch (i) {
865 case NETNSA_PID:
866 case NETNSA_FD:
867 case NETNSA_NSID:
868 case NETNSA_TARGET_NSID:
869 break;
870 default:
871 NL_SET_ERR_MSG(extack, "Unsupported attribute in peer netns getid request");
872 return -EINVAL;
873 }
874 }
875
876 return 0;
877 }
878
rtnl_net_getid(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)879 static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh,
880 struct netlink_ext_ack *extack)
881 {
882 struct net *net = sock_net(skb->sk);
883 struct nlattr *tb[NETNSA_MAX + 1];
884 struct net_fill_args fillargs = {
885 .portid = NETLINK_CB(skb).portid,
886 .seq = nlh->nlmsg_seq,
887 .cmd = RTM_NEWNSID,
888 };
889 struct net *peer, *target = net;
890 struct nlattr *nla;
891 struct sk_buff *msg;
892 int err;
893
894 err = rtnl_net_valid_getid_req(skb, nlh, tb, extack);
895 if (err < 0)
896 return err;
897 if (tb[NETNSA_PID]) {
898 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
899 nla = tb[NETNSA_PID];
900 } else if (tb[NETNSA_FD]) {
901 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
902 nla = tb[NETNSA_FD];
903 } else if (tb[NETNSA_NSID]) {
904 peer = get_net_ns_by_id(net, nla_get_s32(tb[NETNSA_NSID]));
905 if (!peer)
906 peer = ERR_PTR(-ENOENT);
907 nla = tb[NETNSA_NSID];
908 } else {
909 NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
910 return -EINVAL;
911 }
912
913 if (IS_ERR(peer)) {
914 NL_SET_BAD_ATTR(extack, nla);
915 NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
916 return PTR_ERR(peer);
917 }
918
919 if (tb[NETNSA_TARGET_NSID]) {
920 int id = nla_get_s32(tb[NETNSA_TARGET_NSID]);
921
922 target = rtnl_get_net_ns_capable(NETLINK_CB(skb).sk, id);
923 if (IS_ERR(target)) {
924 NL_SET_BAD_ATTR(extack, tb[NETNSA_TARGET_NSID]);
925 NL_SET_ERR_MSG(extack,
926 "Target netns reference is invalid");
927 err = PTR_ERR(target);
928 goto out;
929 }
930 fillargs.add_ref = true;
931 fillargs.ref_nsid = peernet2id(net, peer);
932 }
933
934 msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
935 if (!msg) {
936 err = -ENOMEM;
937 goto out;
938 }
939
940 fillargs.nsid = peernet2id(target, peer);
941 err = rtnl_net_fill(msg, &fillargs);
942 if (err < 0)
943 goto err_out;
944
945 err = rtnl_unicast(msg, net, NETLINK_CB(skb).portid);
946 goto out;
947
948 err_out:
949 nlmsg_free(msg);
950 out:
951 if (fillargs.add_ref)
952 put_net(target);
953 put_net(peer);
954 return err;
955 }
956
957 struct rtnl_net_dump_cb {
958 struct net *tgt_net;
959 struct net *ref_net;
960 struct sk_buff *skb;
961 struct net_fill_args fillargs;
962 int idx;
963 int s_idx;
964 };
965
966 /* Runs in RCU-critical section. */
rtnl_net_dumpid_one(int id,void * peer,void * data)967 static int rtnl_net_dumpid_one(int id, void *peer, void *data)
968 {
969 struct rtnl_net_dump_cb *net_cb = (struct rtnl_net_dump_cb *)data;
970 int ret;
971
972 if (net_cb->idx < net_cb->s_idx)
973 goto cont;
974
975 net_cb->fillargs.nsid = id;
976 if (net_cb->fillargs.add_ref)
977 net_cb->fillargs.ref_nsid = __peernet2id(net_cb->ref_net, peer);
978 ret = rtnl_net_fill(net_cb->skb, &net_cb->fillargs);
979 if (ret < 0)
980 return ret;
981
982 cont:
983 net_cb->idx++;
984 return 0;
985 }
986
rtnl_valid_dump_net_req(const struct nlmsghdr * nlh,struct sock * sk,struct rtnl_net_dump_cb * net_cb,struct netlink_callback * cb)987 static int rtnl_valid_dump_net_req(const struct nlmsghdr *nlh, struct sock *sk,
988 struct rtnl_net_dump_cb *net_cb,
989 struct netlink_callback *cb)
990 {
991 struct netlink_ext_ack *extack = cb->extack;
992 struct nlattr *tb[NETNSA_MAX + 1];
993 int err, i;
994
995 err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct rtgenmsg), tb,
996 NETNSA_MAX, rtnl_net_policy,
997 extack);
998 if (err < 0)
999 return err;
1000
1001 for (i = 0; i <= NETNSA_MAX; i++) {
1002 if (!tb[i])
1003 continue;
1004
1005 if (i == NETNSA_TARGET_NSID) {
1006 struct net *net;
1007
1008 net = rtnl_get_net_ns_capable(sk, nla_get_s32(tb[i]));
1009 if (IS_ERR(net)) {
1010 NL_SET_BAD_ATTR(extack, tb[i]);
1011 NL_SET_ERR_MSG(extack,
1012 "Invalid target network namespace id");
1013 return PTR_ERR(net);
1014 }
1015 net_cb->fillargs.add_ref = true;
1016 net_cb->ref_net = net_cb->tgt_net;
1017 net_cb->tgt_net = net;
1018 } else {
1019 NL_SET_BAD_ATTR(extack, tb[i]);
1020 NL_SET_ERR_MSG(extack,
1021 "Unsupported attribute in dump request");
1022 return -EINVAL;
1023 }
1024 }
1025
1026 return 0;
1027 }
1028
rtnl_net_dumpid(struct sk_buff * skb,struct netlink_callback * cb)1029 static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb)
1030 {
1031 struct rtnl_net_dump_cb net_cb = {
1032 .tgt_net = sock_net(skb->sk),
1033 .skb = skb,
1034 .fillargs = {
1035 .portid = NETLINK_CB(cb->skb).portid,
1036 .seq = cb->nlh->nlmsg_seq,
1037 .flags = NLM_F_MULTI,
1038 .cmd = RTM_NEWNSID,
1039 },
1040 .idx = 0,
1041 .s_idx = cb->args[0],
1042 };
1043 int err = 0;
1044
1045 if (cb->strict_check) {
1046 err = rtnl_valid_dump_net_req(cb->nlh, skb->sk, &net_cb, cb);
1047 if (err < 0)
1048 goto end;
1049 }
1050
1051 rcu_read_lock();
1052 idr_for_each(&net_cb.tgt_net->netns_ids, rtnl_net_dumpid_one, &net_cb);
1053 rcu_read_unlock();
1054
1055 cb->args[0] = net_cb.idx;
1056 end:
1057 if (net_cb.fillargs.add_ref)
1058 put_net(net_cb.tgt_net);
1059 return err < 0 ? err : skb->len;
1060 }
1061
rtnl_net_notifyid(struct net * net,int cmd,int id,u32 portid,struct nlmsghdr * nlh,gfp_t gfp)1062 static void rtnl_net_notifyid(struct net *net, int cmd, int id, u32 portid,
1063 struct nlmsghdr *nlh, gfp_t gfp)
1064 {
1065 struct net_fill_args fillargs = {
1066 .portid = portid,
1067 .seq = nlh ? nlh->nlmsg_seq : 0,
1068 .cmd = cmd,
1069 .nsid = id,
1070 };
1071 struct sk_buff *msg;
1072 int err = -ENOMEM;
1073
1074 msg = nlmsg_new(rtnl_net_get_size(), gfp);
1075 if (!msg)
1076 goto out;
1077
1078 err = rtnl_net_fill(msg, &fillargs);
1079 if (err < 0)
1080 goto err_out;
1081
1082 rtnl_notify(msg, net, portid, RTNLGRP_NSID, nlh, gfp);
1083 return;
1084
1085 err_out:
1086 nlmsg_free(msg);
1087 out:
1088 rtnl_set_sk_err(net, RTNLGRP_NSID, err);
1089 }
1090
net_ns_init(void)1091 void __init net_ns_init(void)
1092 {
1093 struct net_generic *ng;
1094
1095 #ifdef CONFIG_NET_NS
1096 net_cachep = kmem_cache_create("net_namespace", sizeof(struct net),
1097 SMP_CACHE_BYTES,
1098 SLAB_PANIC|SLAB_ACCOUNT, NULL);
1099
1100 /* Create workqueue for cleanup */
1101 netns_wq = create_singlethread_workqueue("netns");
1102 if (!netns_wq)
1103 panic("Could not create netns workq");
1104 #endif
1105
1106 ng = net_alloc_generic();
1107 if (!ng)
1108 panic("Could not allocate generic netns");
1109
1110 rcu_assign_pointer(init_net.gen, ng);
1111
1112 #ifdef CONFIG_KEYS
1113 init_net.key_domain = &init_net_key_domain;
1114 #endif
1115 down_write(&pernet_ops_rwsem);
1116 if (setup_net(&init_net, &init_user_ns))
1117 panic("Could not setup the initial network namespace");
1118
1119 init_net_initialized = true;
1120 up_write(&pernet_ops_rwsem);
1121
1122 if (register_pernet_subsys(&net_ns_ops))
1123 panic("Could not register network namespace subsystems");
1124
1125 rtnl_register(PF_UNSPEC, RTM_NEWNSID, rtnl_net_newid, NULL,
1126 RTNL_FLAG_DOIT_UNLOCKED);
1127 rtnl_register(PF_UNSPEC, RTM_GETNSID, rtnl_net_getid, rtnl_net_dumpid,
1128 RTNL_FLAG_DOIT_UNLOCKED);
1129 }
1130
free_exit_list(struct pernet_operations * ops,struct list_head * net_exit_list)1131 static void free_exit_list(struct pernet_operations *ops, struct list_head *net_exit_list)
1132 {
1133 ops_pre_exit_list(ops, net_exit_list);
1134 synchronize_rcu();
1135 ops_exit_list(ops, net_exit_list);
1136 ops_free_list(ops, net_exit_list);
1137 }
1138
1139 #ifdef CONFIG_NET_NS
__register_pernet_operations(struct list_head * list,struct pernet_operations * ops)1140 static int __register_pernet_operations(struct list_head *list,
1141 struct pernet_operations *ops)
1142 {
1143 struct net *net;
1144 int error;
1145 LIST_HEAD(net_exit_list);
1146
1147 list_add_tail(&ops->list, list);
1148 if (ops->init || (ops->id && ops->size)) {
1149 /* We held write locked pernet_ops_rwsem, and parallel
1150 * setup_net() and cleanup_net() are not possible.
1151 */
1152 for_each_net(net) {
1153 error = ops_init(ops, net);
1154 if (error)
1155 goto out_undo;
1156 list_add_tail(&net->exit_list, &net_exit_list);
1157 }
1158 }
1159 return 0;
1160
1161 out_undo:
1162 /* If I have an error cleanup all namespaces I initialized */
1163 list_del(&ops->list);
1164 free_exit_list(ops, &net_exit_list);
1165 return error;
1166 }
1167
__unregister_pernet_operations(struct pernet_operations * ops)1168 static void __unregister_pernet_operations(struct pernet_operations *ops)
1169 {
1170 struct net *net;
1171 LIST_HEAD(net_exit_list);
1172
1173 list_del(&ops->list);
1174 /* See comment in __register_pernet_operations() */
1175 for_each_net(net)
1176 list_add_tail(&net->exit_list, &net_exit_list);
1177
1178 free_exit_list(ops, &net_exit_list);
1179 }
1180
1181 #else
1182
__register_pernet_operations(struct list_head * list,struct pernet_operations * ops)1183 static int __register_pernet_operations(struct list_head *list,
1184 struct pernet_operations *ops)
1185 {
1186 if (!init_net_initialized) {
1187 list_add_tail(&ops->list, list);
1188 return 0;
1189 }
1190
1191 return ops_init(ops, &init_net);
1192 }
1193
__unregister_pernet_operations(struct pernet_operations * ops)1194 static void __unregister_pernet_operations(struct pernet_operations *ops)
1195 {
1196 if (!init_net_initialized) {
1197 list_del(&ops->list);
1198 } else {
1199 LIST_HEAD(net_exit_list);
1200 list_add(&init_net.exit_list, &net_exit_list);
1201 free_exit_list(ops, &net_exit_list);
1202 }
1203 }
1204
1205 #endif /* CONFIG_NET_NS */
1206
1207 static DEFINE_IDA(net_generic_ids);
1208
register_pernet_operations(struct list_head * list,struct pernet_operations * ops)1209 static int register_pernet_operations(struct list_head *list,
1210 struct pernet_operations *ops)
1211 {
1212 int error;
1213
1214 if (ops->id) {
1215 error = ida_alloc_min(&net_generic_ids, MIN_PERNET_OPS_ID,
1216 GFP_KERNEL);
1217 if (error < 0)
1218 return error;
1219 *ops->id = error;
1220 max_gen_ptrs = max(max_gen_ptrs, *ops->id + 1);
1221 }
1222 error = __register_pernet_operations(list, ops);
1223 if (error) {
1224 rcu_barrier();
1225 if (ops->id)
1226 ida_free(&net_generic_ids, *ops->id);
1227 }
1228
1229 return error;
1230 }
1231
unregister_pernet_operations(struct pernet_operations * ops)1232 static void unregister_pernet_operations(struct pernet_operations *ops)
1233 {
1234 __unregister_pernet_operations(ops);
1235 rcu_barrier();
1236 if (ops->id)
1237 ida_free(&net_generic_ids, *ops->id);
1238 }
1239
1240 /**
1241 * register_pernet_subsys - register a network namespace subsystem
1242 * @ops: pernet operations structure for the subsystem
1243 *
1244 * Register a subsystem which has init and exit functions
1245 * that are called when network namespaces are created and
1246 * destroyed respectively.
1247 *
1248 * When registered all network namespace init functions are
1249 * called for every existing network namespace. Allowing kernel
1250 * modules to have a race free view of the set of network namespaces.
1251 *
1252 * When a new network namespace is created all of the init
1253 * methods are called in the order in which they were registered.
1254 *
1255 * When a network namespace is destroyed all of the exit methods
1256 * are called in the reverse of the order with which they were
1257 * registered.
1258 */
register_pernet_subsys(struct pernet_operations * ops)1259 int register_pernet_subsys(struct pernet_operations *ops)
1260 {
1261 int error;
1262 down_write(&pernet_ops_rwsem);
1263 error = register_pernet_operations(first_device, ops);
1264 up_write(&pernet_ops_rwsem);
1265 return error;
1266 }
1267 EXPORT_SYMBOL_GPL(register_pernet_subsys);
1268
1269 /**
1270 * unregister_pernet_subsys - unregister a network namespace subsystem
1271 * @ops: pernet operations structure to manipulate
1272 *
1273 * Remove the pernet operations structure from the list to be
1274 * used when network namespaces are created or destroyed. In
1275 * addition run the exit method for all existing network
1276 * namespaces.
1277 */
unregister_pernet_subsys(struct pernet_operations * ops)1278 void unregister_pernet_subsys(struct pernet_operations *ops)
1279 {
1280 down_write(&pernet_ops_rwsem);
1281 unregister_pernet_operations(ops);
1282 up_write(&pernet_ops_rwsem);
1283 }
1284 EXPORT_SYMBOL_GPL(unregister_pernet_subsys);
1285
1286 /**
1287 * register_pernet_device - register a network namespace device
1288 * @ops: pernet operations structure for the subsystem
1289 *
1290 * Register a device which has init and exit functions
1291 * that are called when network namespaces are created and
1292 * destroyed respectively.
1293 *
1294 * When registered all network namespace init functions are
1295 * called for every existing network namespace. Allowing kernel
1296 * modules to have a race free view of the set of network namespaces.
1297 *
1298 * When a new network namespace is created all of the init
1299 * methods are called in the order in which they were registered.
1300 *
1301 * When a network namespace is destroyed all of the exit methods
1302 * are called in the reverse of the order with which they were
1303 * registered.
1304 */
register_pernet_device(struct pernet_operations * ops)1305 int register_pernet_device(struct pernet_operations *ops)
1306 {
1307 int error;
1308 down_write(&pernet_ops_rwsem);
1309 error = register_pernet_operations(&pernet_list, ops);
1310 if (!error && (first_device == &pernet_list))
1311 first_device = &ops->list;
1312 up_write(&pernet_ops_rwsem);
1313 return error;
1314 }
1315 EXPORT_SYMBOL_GPL(register_pernet_device);
1316
1317 /**
1318 * unregister_pernet_device - unregister a network namespace netdevice
1319 * @ops: pernet operations structure to manipulate
1320 *
1321 * Remove the pernet operations structure from the list to be
1322 * used when network namespaces are created or destroyed. In
1323 * addition run the exit method for all existing network
1324 * namespaces.
1325 */
unregister_pernet_device(struct pernet_operations * ops)1326 void unregister_pernet_device(struct pernet_operations *ops)
1327 {
1328 down_write(&pernet_ops_rwsem);
1329 if (&ops->list == first_device)
1330 first_device = first_device->next;
1331 unregister_pernet_operations(ops);
1332 up_write(&pernet_ops_rwsem);
1333 }
1334 EXPORT_SYMBOL_GPL(unregister_pernet_device);
1335
1336 #ifdef CONFIG_NET_NS
netns_get(struct task_struct * task)1337 static struct ns_common *netns_get(struct task_struct *task)
1338 {
1339 struct net *net = NULL;
1340 struct nsproxy *nsproxy;
1341
1342 task_lock(task);
1343 nsproxy = task->nsproxy;
1344 if (nsproxy)
1345 net = get_net(nsproxy->net_ns);
1346 task_unlock(task);
1347
1348 return net ? &net->ns : NULL;
1349 }
1350
to_net_ns(struct ns_common * ns)1351 static inline struct net *to_net_ns(struct ns_common *ns)
1352 {
1353 return container_of(ns, struct net, ns);
1354 }
1355
netns_put(struct ns_common * ns)1356 static void netns_put(struct ns_common *ns)
1357 {
1358 put_net(to_net_ns(ns));
1359 }
1360
netns_install(struct nsset * nsset,struct ns_common * ns)1361 static int netns_install(struct nsset *nsset, struct ns_common *ns)
1362 {
1363 struct nsproxy *nsproxy = nsset->nsproxy;
1364 struct net *net = to_net_ns(ns);
1365
1366 if (!ns_capable(net->user_ns, CAP_SYS_ADMIN) ||
1367 !ns_capable(nsset->cred->user_ns, CAP_SYS_ADMIN))
1368 return -EPERM;
1369
1370 put_net(nsproxy->net_ns);
1371 nsproxy->net_ns = get_net(net);
1372 return 0;
1373 }
1374
netns_owner(struct ns_common * ns)1375 static struct user_namespace *netns_owner(struct ns_common *ns)
1376 {
1377 return to_net_ns(ns)->user_ns;
1378 }
1379
1380 const struct proc_ns_operations netns_operations = {
1381 .name = "net",
1382 .type = CLONE_NEWNET,
1383 .get = netns_get,
1384 .put = netns_put,
1385 .install = netns_install,
1386 .owner = netns_owner,
1387 };
1388 #endif
1389