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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#include <linux/proc_fs.h>
24
25#include <net/sock.h>
26#include <net/netlink.h>
27#include <net/net_namespace.h>
28#include <net/netns/generic.h>
29
30/*
31 * Our network namespace constructor/destructor lists
32 */
33
34static LIST_HEAD(pernet_list);
35static struct list_head *first_device = &pernet_list;
36
37LIST_HEAD(net_namespace_list);
38EXPORT_SYMBOL_GPL(net_namespace_list);
39
40/* Protects net_namespace_list. Nests iside rtnl_lock() */
41DECLARE_RWSEM(net_rwsem);
42EXPORT_SYMBOL_GPL(net_rwsem);
43
44#ifdef CONFIG_KEYS
45static struct key_tag init_net_key_domain = { .usage = REFCOUNT_INIT(1) };
46#endif
47
48struct net init_net;
49EXPORT_SYMBOL(init_net);
50
51static bool init_net_initialized;
52/*
53 * pernet_ops_rwsem: protects: pernet_list, net_generic_ids,
54 * init_net_initialized and first_device pointer.
55 * This is internal net namespace object. Please, don't use it
56 * outside.
57 */
58DECLARE_RWSEM(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
65static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS;
66
67DEFINE_COOKIE(net_cookie);
68
69static struct net_generic *net_alloc_generic(void)
70{
71 unsigned int gen_ptrs = READ_ONCE(max_gen_ptrs);
72 unsigned int generic_size;
73 struct net_generic *ng;
74
75 generic_size = offsetof(struct net_generic, ptr[gen_ptrs]);
76
77 ng = kzalloc(generic_size, GFP_KERNEL);
78 if (ng)
79 ng->s.len = gen_ptrs;
80
81 return ng;
82}
83
84static int net_assign_generic(struct net *net, unsigned int id, void *data)
85{
86 struct net_generic *ng, *old_ng;
87
88 BUG_ON(id < MIN_PERNET_OPS_ID);
89
90 old_ng = rcu_dereference_protected(net->gen,
91 lockdep_is_held(&pernet_ops_rwsem));
92 if (old_ng->s.len > id) {
93 old_ng->ptr[id] = data;
94 return 0;
95 }
96
97 ng = net_alloc_generic();
98 if (!ng)
99 return -ENOMEM;
100
101 /*
102 * Some synchronisation notes:
103 *
104 * The net_generic explores the net->gen array inside rcu
105 * read section. Besides once set the net->gen->ptr[x]
106 * pointer never changes (see rules in netns/generic.h).
107 *
108 * That said, we simply duplicate this array and schedule
109 * the old copy for kfree after a grace period.
110 */
111
112 memcpy(&ng->ptr[MIN_PERNET_OPS_ID], &old_ng->ptr[MIN_PERNET_OPS_ID],
113 (old_ng->s.len - MIN_PERNET_OPS_ID) * sizeof(void *));
114 ng->ptr[id] = data;
115
116 rcu_assign_pointer(net->gen, ng);
117 kfree_rcu(old_ng, s.rcu);
118 return 0;
119}
120
121static int ops_init(const struct pernet_operations *ops, struct net *net)
122{
123 struct net_generic *ng;
124 int err = -ENOMEM;
125 void *data = NULL;
126
127 if (ops->id) {
128 data = kzalloc(ops->size, GFP_KERNEL);
129 if (!data)
130 goto out;
131
132 err = net_assign_generic(net, *ops->id, data);
133 if (err)
134 goto cleanup;
135 }
136 err = 0;
137 if (ops->init)
138 err = ops->init(net);
139 if (!err)
140 return 0;
141
142 if (ops->id) {
143 ng = rcu_dereference_protected(net->gen,
144 lockdep_is_held(&pernet_ops_rwsem));
145 ng->ptr[*ops->id] = NULL;
146 }
147
148cleanup:
149 kfree(data);
150
151out:
152 return err;
153}
154
155static void ops_pre_exit_list(const struct pernet_operations *ops,
156 struct list_head *net_exit_list)
157{
158 struct net *net;
159
160 if (ops->pre_exit) {
161 list_for_each_entry(net, net_exit_list, exit_list)
162 ops->pre_exit(net);
163 }
164}
165
166static void ops_exit_list(const struct pernet_operations *ops,
167 struct list_head *net_exit_list)
168{
169 struct net *net;
170 if (ops->exit) {
171 list_for_each_entry(net, net_exit_list, exit_list) {
172 ops->exit(net);
173 cond_resched();
174 }
175 }
176 if (ops->exit_batch)
177 ops->exit_batch(net_exit_list);
178}
179
180static void ops_free_list(const struct pernet_operations *ops,
181 struct list_head *net_exit_list)
182{
183 struct net *net;
184
185 if (ops->id) {
186 list_for_each_entry(net, net_exit_list, exit_list)
187 kfree(net_generic(net, *ops->id));
188 }
189}
190
191/* should be called with nsid_lock held */
192static int alloc_netid(struct net *net, struct net *peer, int reqid)
193{
194 int min = 0, max = 0;
195
196 if (reqid >= 0) {
197 min = reqid;
198 max = reqid + 1;
199 }
200
201 return idr_alloc(&net->netns_ids, peer, min, max, GFP_ATOMIC);
202}
203
204/* This function is used by idr_for_each(). If net is equal to peer, the
205 * function returns the id so that idr_for_each() stops. Because we cannot
206 * returns the id 0 (idr_for_each() will not stop), we return the magic value
207 * NET_ID_ZERO (-1) for it.
208 */
209#define NET_ID_ZERO -1
210static int net_eq_idr(int id, void *net, void *peer)
211{
212 if (net_eq(net, peer))
213 return id ? : NET_ID_ZERO;
214 return 0;
215}
216
217/* Must be called from RCU-critical section or with nsid_lock held */
218static int __peernet2id(const struct net *net, struct net *peer)
219{
220 int id = idr_for_each(&net->netns_ids, net_eq_idr, peer);
221
222 /* Magic value for id 0. */
223 if (id == NET_ID_ZERO)
224 return 0;
225 if (id > 0)
226 return id;
227
228 return NETNSA_NSID_NOT_ASSIGNED;
229}
230
231static void rtnl_net_notifyid(struct net *net, int cmd, int id, u32 portid,
232 struct nlmsghdr *nlh, gfp_t gfp);
233/* This function returns the id of a peer netns. If no id is assigned, one will
234 * be allocated and returned.
235 */
236int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp)
237{
238 int id;
239
240 if (refcount_read(&net->ns.count) == 0)
241 return NETNSA_NSID_NOT_ASSIGNED;
242
243 spin_lock_bh(&net->nsid_lock);
244 id = __peernet2id(net, peer);
245 if (id >= 0) {
246 spin_unlock_bh(&net->nsid_lock);
247 return id;
248 }
249
250 /* When peer is obtained from RCU lists, we may race with
251 * its cleanup. Check whether it's alive, and this guarantees
252 * we never hash a peer back to net->netns_ids, after it has
253 * just been idr_remove()'d from there in cleanup_net().
254 */
255 if (!maybe_get_net(peer)) {
256 spin_unlock_bh(&net->nsid_lock);
257 return NETNSA_NSID_NOT_ASSIGNED;
258 }
259
260 id = alloc_netid(net, peer, -1);
261 spin_unlock_bh(&net->nsid_lock);
262
263 put_net(peer);
264 if (id < 0)
265 return NETNSA_NSID_NOT_ASSIGNED;
266
267 rtnl_net_notifyid(net, RTM_NEWNSID, id, 0, NULL, gfp);
268
269 return id;
270}
271EXPORT_SYMBOL_GPL(peernet2id_alloc);
272
273/* This function returns, if assigned, the id of a peer netns. */
274int peernet2id(const struct net *net, struct net *peer)
275{
276 int id;
277
278 rcu_read_lock();
279 id = __peernet2id(net, peer);
280 rcu_read_unlock();
281
282 return id;
283}
284EXPORT_SYMBOL(peernet2id);
285
286/* This function returns true is the peer netns has an id assigned into the
287 * current netns.
288 */
289bool peernet_has_id(const struct net *net, struct net *peer)
290{
291 return peernet2id(net, peer) >= 0;
292}
293
294struct net *get_net_ns_by_id(const struct net *net, int id)
295{
296 struct net *peer;
297
298 if (id < 0)
299 return NULL;
300
301 rcu_read_lock();
302 peer = idr_find(&net->netns_ids, id);
303 if (peer)
304 peer = maybe_get_net(peer);
305 rcu_read_unlock();
306
307 return peer;
308}
309EXPORT_SYMBOL_GPL(get_net_ns_by_id);
310
311static __net_init void preinit_net_sysctl(struct net *net)
312{
313 net->core.sysctl_somaxconn = SOMAXCONN;
314 /* Limits per socket sk_omem_alloc usage.
315 * TCP zerocopy regular usage needs 128 KB.
316 */
317 net->core.sysctl_optmem_max = 128 * 1024;
318 net->core.sysctl_txrehash = SOCK_TXREHASH_ENABLED;
319 net->core.sysctl_tstamp_allow_data = 1;
320}
321
322/* init code that must occur even if setup_net() is not called. */
323static __net_init void preinit_net(struct net *net, struct user_namespace *user_ns)
324{
325 refcount_set(&net->passive, 1);
326 refcount_set(&net->ns.count, 1);
327 ref_tracker_dir_init(&net->refcnt_tracker, 128, "net refcnt");
328 ref_tracker_dir_init(&net->notrefcnt_tracker, 128, "net notrefcnt");
329
330 get_random_bytes(&net->hash_mix, sizeof(u32));
331 net->dev_base_seq = 1;
332 net->user_ns = user_ns;
333
334 idr_init(&net->netns_ids);
335 spin_lock_init(&net->nsid_lock);
336 mutex_init(&net->ipv4.ra_mutex);
337
338#ifdef CONFIG_DEBUG_NET_SMALL_RTNL
339 mutex_init(&net->rtnl_mutex);
340 lock_set_cmp_fn(&net->rtnl_mutex, rtnl_net_lock_cmp_fn, NULL);
341#endif
342
343 preinit_net_sysctl(net);
344}
345
346/*
347 * setup_net runs the initializers for the network namespace object.
348 */
349static __net_init int setup_net(struct net *net)
350{
351 /* Must be called with pernet_ops_rwsem held */
352 const struct pernet_operations *ops, *saved_ops;
353 LIST_HEAD(net_exit_list);
354 LIST_HEAD(dev_kill_list);
355 int error = 0;
356
357 preempt_disable();
358 net->net_cookie = gen_cookie_next(&net_cookie);
359 preempt_enable();
360
361 list_for_each_entry(ops, &pernet_list, list) {
362 error = ops_init(ops, net);
363 if (error < 0)
364 goto out_undo;
365 }
366 down_write(&net_rwsem);
367 list_add_tail_rcu(&net->list, &net_namespace_list);
368 up_write(&net_rwsem);
369out:
370 return error;
371
372out_undo:
373 /* Walk through the list backwards calling the exit functions
374 * for the pernet modules whose init functions did not fail.
375 */
376 list_add(&net->exit_list, &net_exit_list);
377 saved_ops = ops;
378 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
379 ops_pre_exit_list(ops, &net_exit_list);
380
381 synchronize_rcu();
382
383 ops = saved_ops;
384 rtnl_lock();
385 list_for_each_entry_continue_reverse(ops, &pernet_list, list) {
386 if (ops->exit_batch_rtnl)
387 ops->exit_batch_rtnl(&net_exit_list, &dev_kill_list);
388 }
389 unregister_netdevice_many(&dev_kill_list);
390 rtnl_unlock();
391
392 ops = saved_ops;
393 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
394 ops_exit_list(ops, &net_exit_list);
395
396 ops = saved_ops;
397 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
398 ops_free_list(ops, &net_exit_list);
399
400 rcu_barrier();
401 goto out;
402}
403
404#ifdef CONFIG_NET_NS
405static struct ucounts *inc_net_namespaces(struct user_namespace *ns)
406{
407 return inc_ucount(ns, current_euid(), UCOUNT_NET_NAMESPACES);
408}
409
410static void dec_net_namespaces(struct ucounts *ucounts)
411{
412 dec_ucount(ucounts, UCOUNT_NET_NAMESPACES);
413}
414
415static struct kmem_cache *net_cachep __ro_after_init;
416static struct workqueue_struct *netns_wq;
417
418static struct net *net_alloc(void)
419{
420 struct net *net = NULL;
421 struct net_generic *ng;
422
423 ng = net_alloc_generic();
424 if (!ng)
425 goto out;
426
427 net = kmem_cache_zalloc(net_cachep, GFP_KERNEL);
428 if (!net)
429 goto out_free;
430
431#ifdef CONFIG_KEYS
432 net->key_domain = kzalloc(sizeof(struct key_tag), GFP_KERNEL);
433 if (!net->key_domain)
434 goto out_free_2;
435 refcount_set(&net->key_domain->usage, 1);
436#endif
437
438 rcu_assign_pointer(net->gen, ng);
439out:
440 return net;
441
442#ifdef CONFIG_KEYS
443out_free_2:
444 kmem_cache_free(net_cachep, net);
445 net = NULL;
446#endif
447out_free:
448 kfree(ng);
449 goto out;
450}
451
452static LLIST_HEAD(defer_free_list);
453
454static void net_complete_free(void)
455{
456 struct llist_node *kill_list;
457 struct net *net, *next;
458
459 /* Get the list of namespaces to free from last round. */
460 kill_list = llist_del_all(&defer_free_list);
461
462 llist_for_each_entry_safe(net, next, kill_list, defer_free_list)
463 kmem_cache_free(net_cachep, net);
464
465}
466
467void net_passive_dec(struct net *net)
468{
469 if (refcount_dec_and_test(&net->passive)) {
470 kfree(rcu_access_pointer(net->gen));
471
472 /* There should not be any trackers left there. */
473 ref_tracker_dir_exit(&net->notrefcnt_tracker);
474
475 /* Wait for an extra rcu_barrier() before final free. */
476 llist_add(&net->defer_free_list, &defer_free_list);
477 }
478}
479
480void net_drop_ns(void *p)
481{
482 struct net *net = (struct net *)p;
483
484 if (net)
485 net_passive_dec(net);
486}
487
488struct net *copy_net_ns(unsigned long flags,
489 struct user_namespace *user_ns, struct net *old_net)
490{
491 struct ucounts *ucounts;
492 struct net *net;
493 int rv;
494
495 if (!(flags & CLONE_NEWNET))
496 return get_net(old_net);
497
498 ucounts = inc_net_namespaces(user_ns);
499 if (!ucounts)
500 return ERR_PTR(-ENOSPC);
501
502 net = net_alloc();
503 if (!net) {
504 rv = -ENOMEM;
505 goto dec_ucounts;
506 }
507
508 preinit_net(net, user_ns);
509 net->ucounts = ucounts;
510 get_user_ns(user_ns);
511
512 rv = down_read_killable(&pernet_ops_rwsem);
513 if (rv < 0)
514 goto put_userns;
515
516 rv = setup_net(net);
517
518 up_read(&pernet_ops_rwsem);
519
520 if (rv < 0) {
521put_userns:
522#ifdef CONFIG_KEYS
523 key_remove_domain(net->key_domain);
524#endif
525 put_user_ns(user_ns);
526 net_passive_dec(net);
527dec_ucounts:
528 dec_net_namespaces(ucounts);
529 return ERR_PTR(rv);
530 }
531 return net;
532}
533
534/**
535 * net_ns_get_ownership - get sysfs ownership data for @net
536 * @net: network namespace in question (can be NULL)
537 * @uid: kernel user ID for sysfs objects
538 * @gid: kernel group ID for sysfs objects
539 *
540 * Returns the uid/gid pair of root in the user namespace associated with the
541 * given network namespace.
542 */
543void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid)
544{
545 if (net) {
546 kuid_t ns_root_uid = make_kuid(net->user_ns, 0);
547 kgid_t ns_root_gid = make_kgid(net->user_ns, 0);
548
549 if (uid_valid(ns_root_uid))
550 *uid = ns_root_uid;
551
552 if (gid_valid(ns_root_gid))
553 *gid = ns_root_gid;
554 } else {
555 *uid = GLOBAL_ROOT_UID;
556 *gid = GLOBAL_ROOT_GID;
557 }
558}
559EXPORT_SYMBOL_GPL(net_ns_get_ownership);
560
561static void unhash_nsid(struct net *net, struct net *last)
562{
563 struct net *tmp;
564 /* This function is only called from cleanup_net() work,
565 * and this work is the only process, that may delete
566 * a net from net_namespace_list. So, when the below
567 * is executing, the list may only grow. Thus, we do not
568 * use for_each_net_rcu() or net_rwsem.
569 */
570 for_each_net(tmp) {
571 int id;
572
573 spin_lock_bh(&tmp->nsid_lock);
574 id = __peernet2id(tmp, net);
575 if (id >= 0)
576 idr_remove(&tmp->netns_ids, id);
577 spin_unlock_bh(&tmp->nsid_lock);
578 if (id >= 0)
579 rtnl_net_notifyid(tmp, RTM_DELNSID, id, 0, NULL,
580 GFP_KERNEL);
581 if (tmp == last)
582 break;
583 }
584 spin_lock_bh(&net->nsid_lock);
585 idr_destroy(&net->netns_ids);
586 spin_unlock_bh(&net->nsid_lock);
587}
588
589static LLIST_HEAD(cleanup_list);
590
591static void cleanup_net(struct work_struct *work)
592{
593 const struct pernet_operations *ops;
594 struct net *net, *tmp, *last;
595 struct llist_node *net_kill_list;
596 LIST_HEAD(net_exit_list);
597 LIST_HEAD(dev_kill_list);
598
599 /* Atomically snapshot the list of namespaces to cleanup */
600 net_kill_list = llist_del_all(&cleanup_list);
601
602 down_read(&pernet_ops_rwsem);
603
604 /* Don't let anyone else find us. */
605 down_write(&net_rwsem);
606 llist_for_each_entry(net, net_kill_list, cleanup_list)
607 list_del_rcu(&net->list);
608 /* Cache last net. After we unlock rtnl, no one new net
609 * added to net_namespace_list can assign nsid pointer
610 * to a net from net_kill_list (see peernet2id_alloc()).
611 * So, we skip them in unhash_nsid().
612 *
613 * Note, that unhash_nsid() does not delete nsid links
614 * between net_kill_list's nets, as they've already
615 * deleted from net_namespace_list. But, this would be
616 * useless anyway, as netns_ids are destroyed there.
617 */
618 last = list_last_entry(&net_namespace_list, struct net, list);
619 up_write(&net_rwsem);
620
621 llist_for_each_entry(net, net_kill_list, cleanup_list) {
622 unhash_nsid(net, last);
623 list_add_tail(&net->exit_list, &net_exit_list);
624 }
625
626 /* Run all of the network namespace pre_exit methods */
627 list_for_each_entry_reverse(ops, &pernet_list, list)
628 ops_pre_exit_list(ops, &net_exit_list);
629
630 /*
631 * Another CPU might be rcu-iterating the list, wait for it.
632 * This needs to be before calling the exit() notifiers, so
633 * the rcu_barrier() below isn't sufficient alone.
634 * Also the pre_exit() and exit() methods need this barrier.
635 */
636 synchronize_rcu_expedited();
637
638 rtnl_lock();
639 list_for_each_entry_reverse(ops, &pernet_list, list) {
640 if (ops->exit_batch_rtnl)
641 ops->exit_batch_rtnl(&net_exit_list, &dev_kill_list);
642 }
643 unregister_netdevice_many(&dev_kill_list);
644 rtnl_unlock();
645
646 /* Run all of the network namespace exit methods */
647 list_for_each_entry_reverse(ops, &pernet_list, list)
648 ops_exit_list(ops, &net_exit_list);
649
650 /* Free the net generic variables */
651 list_for_each_entry_reverse(ops, &pernet_list, list)
652 ops_free_list(ops, &net_exit_list);
653
654 up_read(&pernet_ops_rwsem);
655
656 /* Ensure there are no outstanding rcu callbacks using this
657 * network namespace.
658 */
659 rcu_barrier();
660
661 net_complete_free();
662
663 /* Finally it is safe to free my network namespace structure */
664 list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
665 list_del_init(&net->exit_list);
666 dec_net_namespaces(net->ucounts);
667#ifdef CONFIG_KEYS
668 key_remove_domain(net->key_domain);
669#endif
670 put_user_ns(net->user_ns);
671 net_passive_dec(net);
672 }
673}
674
675/**
676 * net_ns_barrier - wait until concurrent net_cleanup_work is done
677 *
678 * cleanup_net runs from work queue and will first remove namespaces
679 * from the global list, then run net exit functions.
680 *
681 * Call this in module exit path to make sure that all netns
682 * ->exit ops have been invoked before the function is removed.
683 */
684void net_ns_barrier(void)
685{
686 down_write(&pernet_ops_rwsem);
687 up_write(&pernet_ops_rwsem);
688}
689EXPORT_SYMBOL(net_ns_barrier);
690
691static DECLARE_WORK(net_cleanup_work, cleanup_net);
692
693void __put_net(struct net *net)
694{
695 ref_tracker_dir_exit(&net->refcnt_tracker);
696 /* Cleanup the network namespace in process context */
697 if (llist_add(&net->cleanup_list, &cleanup_list))
698 queue_work(netns_wq, &net_cleanup_work);
699}
700EXPORT_SYMBOL_GPL(__put_net);
701
702/**
703 * get_net_ns - increment the refcount of the network namespace
704 * @ns: common namespace (net)
705 *
706 * Returns the net's common namespace or ERR_PTR() if ref is zero.
707 */
708struct ns_common *get_net_ns(struct ns_common *ns)
709{
710 struct net *net;
711
712 net = maybe_get_net(container_of(ns, struct net, ns));
713 if (net)
714 return &net->ns;
715 return ERR_PTR(-EINVAL);
716}
717EXPORT_SYMBOL_GPL(get_net_ns);
718
719struct net *get_net_ns_by_fd(int fd)
720{
721 CLASS(fd, f)(fd);
722
723 if (fd_empty(f))
724 return ERR_PTR(-EBADF);
725
726 if (proc_ns_file(fd_file(f))) {
727 struct ns_common *ns = get_proc_ns(file_inode(fd_file(f)));
728 if (ns->ops == &netns_operations)
729 return get_net(container_of(ns, struct net, ns));
730 }
731
732 return ERR_PTR(-EINVAL);
733}
734EXPORT_SYMBOL_GPL(get_net_ns_by_fd);
735#endif
736
737struct net *get_net_ns_by_pid(pid_t pid)
738{
739 struct task_struct *tsk;
740 struct net *net;
741
742 /* Lookup the network namespace */
743 net = ERR_PTR(-ESRCH);
744 rcu_read_lock();
745 tsk = find_task_by_vpid(pid);
746 if (tsk) {
747 struct nsproxy *nsproxy;
748 task_lock(tsk);
749 nsproxy = tsk->nsproxy;
750 if (nsproxy)
751 net = get_net(nsproxy->net_ns);
752 task_unlock(tsk);
753 }
754 rcu_read_unlock();
755 return net;
756}
757EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
758
759static __net_init int net_ns_net_init(struct net *net)
760{
761#ifdef CONFIG_NET_NS
762 net->ns.ops = &netns_operations;
763#endif
764 return ns_alloc_inum(&net->ns);
765}
766
767static __net_exit void net_ns_net_exit(struct net *net)
768{
769 ns_free_inum(&net->ns);
770}
771
772static struct pernet_operations __net_initdata net_ns_ops = {
773 .init = net_ns_net_init,
774 .exit = net_ns_net_exit,
775};
776
777static const struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = {
778 [NETNSA_NONE] = { .type = NLA_UNSPEC },
779 [NETNSA_NSID] = { .type = NLA_S32 },
780 [NETNSA_PID] = { .type = NLA_U32 },
781 [NETNSA_FD] = { .type = NLA_U32 },
782 [NETNSA_TARGET_NSID] = { .type = NLA_S32 },
783};
784
785static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh,
786 struct netlink_ext_ack *extack)
787{
788 struct net *net = sock_net(skb->sk);
789 struct nlattr *tb[NETNSA_MAX + 1];
790 struct nlattr *nla;
791 struct net *peer;
792 int nsid, err;
793
794 err = nlmsg_parse_deprecated(nlh, sizeof(struct rtgenmsg), tb,
795 NETNSA_MAX, rtnl_net_policy, extack);
796 if (err < 0)
797 return err;
798 if (!tb[NETNSA_NSID]) {
799 NL_SET_ERR_MSG(extack, "nsid is missing");
800 return -EINVAL;
801 }
802 nsid = nla_get_s32(tb[NETNSA_NSID]);
803
804 if (tb[NETNSA_PID]) {
805 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
806 nla = tb[NETNSA_PID];
807 } else if (tb[NETNSA_FD]) {
808 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
809 nla = tb[NETNSA_FD];
810 } else {
811 NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
812 return -EINVAL;
813 }
814 if (IS_ERR(peer)) {
815 NL_SET_BAD_ATTR(extack, nla);
816 NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
817 return PTR_ERR(peer);
818 }
819
820 spin_lock_bh(&net->nsid_lock);
821 if (__peernet2id(net, peer) >= 0) {
822 spin_unlock_bh(&net->nsid_lock);
823 err = -EEXIST;
824 NL_SET_BAD_ATTR(extack, nla);
825 NL_SET_ERR_MSG(extack,
826 "Peer netns already has a nsid assigned");
827 goto out;
828 }
829
830 err = alloc_netid(net, peer, nsid);
831 spin_unlock_bh(&net->nsid_lock);
832 if (err >= 0) {
833 rtnl_net_notifyid(net, RTM_NEWNSID, err, NETLINK_CB(skb).portid,
834 nlh, GFP_KERNEL);
835 err = 0;
836 } else if (err == -ENOSPC && nsid >= 0) {
837 err = -EEXIST;
838 NL_SET_BAD_ATTR(extack, tb[NETNSA_NSID]);
839 NL_SET_ERR_MSG(extack, "The specified nsid is already used");
840 }
841out:
842 put_net(peer);
843 return err;
844}
845
846static int rtnl_net_get_size(void)
847{
848 return NLMSG_ALIGN(sizeof(struct rtgenmsg))
849 + nla_total_size(sizeof(s32)) /* NETNSA_NSID */
850 + nla_total_size(sizeof(s32)) /* NETNSA_CURRENT_NSID */
851 ;
852}
853
854struct net_fill_args {
855 u32 portid;
856 u32 seq;
857 int flags;
858 int cmd;
859 int nsid;
860 bool add_ref;
861 int ref_nsid;
862};
863
864static int rtnl_net_fill(struct sk_buff *skb, struct net_fill_args *args)
865{
866 struct nlmsghdr *nlh;
867 struct rtgenmsg *rth;
868
869 nlh = nlmsg_put(skb, args->portid, args->seq, args->cmd, sizeof(*rth),
870 args->flags);
871 if (!nlh)
872 return -EMSGSIZE;
873
874 rth = nlmsg_data(nlh);
875 rth->rtgen_family = AF_UNSPEC;
876
877 if (nla_put_s32(skb, NETNSA_NSID, args->nsid))
878 goto nla_put_failure;
879
880 if (args->add_ref &&
881 nla_put_s32(skb, NETNSA_CURRENT_NSID, args->ref_nsid))
882 goto nla_put_failure;
883
884 nlmsg_end(skb, nlh);
885 return 0;
886
887nla_put_failure:
888 nlmsg_cancel(skb, nlh);
889 return -EMSGSIZE;
890}
891
892static int rtnl_net_valid_getid_req(struct sk_buff *skb,
893 const struct nlmsghdr *nlh,
894 struct nlattr **tb,
895 struct netlink_ext_ack *extack)
896{
897 int i, err;
898
899 if (!netlink_strict_get_check(skb))
900 return nlmsg_parse_deprecated(nlh, sizeof(struct rtgenmsg),
901 tb, NETNSA_MAX, rtnl_net_policy,
902 extack);
903
904 err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct rtgenmsg), tb,
905 NETNSA_MAX, rtnl_net_policy,
906 extack);
907 if (err)
908 return err;
909
910 for (i = 0; i <= NETNSA_MAX; i++) {
911 if (!tb[i])
912 continue;
913
914 switch (i) {
915 case NETNSA_PID:
916 case NETNSA_FD:
917 case NETNSA_NSID:
918 case NETNSA_TARGET_NSID:
919 break;
920 default:
921 NL_SET_ERR_MSG(extack, "Unsupported attribute in peer netns getid request");
922 return -EINVAL;
923 }
924 }
925
926 return 0;
927}
928
929static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh,
930 struct netlink_ext_ack *extack)
931{
932 struct net *net = sock_net(skb->sk);
933 struct nlattr *tb[NETNSA_MAX + 1];
934 struct net_fill_args fillargs = {
935 .portid = NETLINK_CB(skb).portid,
936 .seq = nlh->nlmsg_seq,
937 .cmd = RTM_NEWNSID,
938 };
939 struct net *peer, *target = net;
940 struct nlattr *nla;
941 struct sk_buff *msg;
942 int err;
943
944 err = rtnl_net_valid_getid_req(skb, nlh, tb, extack);
945 if (err < 0)
946 return err;
947 if (tb[NETNSA_PID]) {
948 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
949 nla = tb[NETNSA_PID];
950 } else if (tb[NETNSA_FD]) {
951 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
952 nla = tb[NETNSA_FD];
953 } else if (tb[NETNSA_NSID]) {
954 peer = get_net_ns_by_id(net, nla_get_s32(tb[NETNSA_NSID]));
955 if (!peer)
956 peer = ERR_PTR(-ENOENT);
957 nla = tb[NETNSA_NSID];
958 } else {
959 NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
960 return -EINVAL;
961 }
962
963 if (IS_ERR(peer)) {
964 NL_SET_BAD_ATTR(extack, nla);
965 NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
966 return PTR_ERR(peer);
967 }
968
969 if (tb[NETNSA_TARGET_NSID]) {
970 int id = nla_get_s32(tb[NETNSA_TARGET_NSID]);
971
972 target = rtnl_get_net_ns_capable(NETLINK_CB(skb).sk, id);
973 if (IS_ERR(target)) {
974 NL_SET_BAD_ATTR(extack, tb[NETNSA_TARGET_NSID]);
975 NL_SET_ERR_MSG(extack,
976 "Target netns reference is invalid");
977 err = PTR_ERR(target);
978 goto out;
979 }
980 fillargs.add_ref = true;
981 fillargs.ref_nsid = peernet2id(net, peer);
982 }
983
984 msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
985 if (!msg) {
986 err = -ENOMEM;
987 goto out;
988 }
989
990 fillargs.nsid = peernet2id(target, peer);
991 err = rtnl_net_fill(msg, &fillargs);
992 if (err < 0)
993 goto err_out;
994
995 err = rtnl_unicast(msg, net, NETLINK_CB(skb).portid);
996 goto out;
997
998err_out:
999 nlmsg_free(msg);
1000out:
1001 if (fillargs.add_ref)
1002 put_net(target);
1003 put_net(peer);
1004 return err;
1005}
1006
1007struct rtnl_net_dump_cb {
1008 struct net *tgt_net;
1009 struct net *ref_net;
1010 struct sk_buff *skb;
1011 struct net_fill_args fillargs;
1012 int idx;
1013 int s_idx;
1014};
1015
1016/* Runs in RCU-critical section. */
1017static int rtnl_net_dumpid_one(int id, void *peer, void *data)
1018{
1019 struct rtnl_net_dump_cb *net_cb = (struct rtnl_net_dump_cb *)data;
1020 int ret;
1021
1022 if (net_cb->idx < net_cb->s_idx)
1023 goto cont;
1024
1025 net_cb->fillargs.nsid = id;
1026 if (net_cb->fillargs.add_ref)
1027 net_cb->fillargs.ref_nsid = __peernet2id(net_cb->ref_net, peer);
1028 ret = rtnl_net_fill(net_cb->skb, &net_cb->fillargs);
1029 if (ret < 0)
1030 return ret;
1031
1032cont:
1033 net_cb->idx++;
1034 return 0;
1035}
1036
1037static int rtnl_valid_dump_net_req(const struct nlmsghdr *nlh, struct sock *sk,
1038 struct rtnl_net_dump_cb *net_cb,
1039 struct netlink_callback *cb)
1040{
1041 struct netlink_ext_ack *extack = cb->extack;
1042 struct nlattr *tb[NETNSA_MAX + 1];
1043 int err, i;
1044
1045 err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct rtgenmsg), tb,
1046 NETNSA_MAX, rtnl_net_policy,
1047 extack);
1048 if (err < 0)
1049 return err;
1050
1051 for (i = 0; i <= NETNSA_MAX; i++) {
1052 if (!tb[i])
1053 continue;
1054
1055 if (i == NETNSA_TARGET_NSID) {
1056 struct net *net;
1057
1058 net = rtnl_get_net_ns_capable(sk, nla_get_s32(tb[i]));
1059 if (IS_ERR(net)) {
1060 NL_SET_BAD_ATTR(extack, tb[i]);
1061 NL_SET_ERR_MSG(extack,
1062 "Invalid target network namespace id");
1063 return PTR_ERR(net);
1064 }
1065 net_cb->fillargs.add_ref = true;
1066 net_cb->ref_net = net_cb->tgt_net;
1067 net_cb->tgt_net = net;
1068 } else {
1069 NL_SET_BAD_ATTR(extack, tb[i]);
1070 NL_SET_ERR_MSG(extack,
1071 "Unsupported attribute in dump request");
1072 return -EINVAL;
1073 }
1074 }
1075
1076 return 0;
1077}
1078
1079static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb)
1080{
1081 struct rtnl_net_dump_cb net_cb = {
1082 .tgt_net = sock_net(skb->sk),
1083 .skb = skb,
1084 .fillargs = {
1085 .portid = NETLINK_CB(cb->skb).portid,
1086 .seq = cb->nlh->nlmsg_seq,
1087 .flags = NLM_F_MULTI,
1088 .cmd = RTM_NEWNSID,
1089 },
1090 .idx = 0,
1091 .s_idx = cb->args[0],
1092 };
1093 int err = 0;
1094
1095 if (cb->strict_check) {
1096 err = rtnl_valid_dump_net_req(cb->nlh, skb->sk, &net_cb, cb);
1097 if (err < 0)
1098 goto end;
1099 }
1100
1101 rcu_read_lock();
1102 idr_for_each(&net_cb.tgt_net->netns_ids, rtnl_net_dumpid_one, &net_cb);
1103 rcu_read_unlock();
1104
1105 cb->args[0] = net_cb.idx;
1106end:
1107 if (net_cb.fillargs.add_ref)
1108 put_net(net_cb.tgt_net);
1109 return err;
1110}
1111
1112static void rtnl_net_notifyid(struct net *net, int cmd, int id, u32 portid,
1113 struct nlmsghdr *nlh, gfp_t gfp)
1114{
1115 struct net_fill_args fillargs = {
1116 .portid = portid,
1117 .seq = nlh ? nlh->nlmsg_seq : 0,
1118 .cmd = cmd,
1119 .nsid = id,
1120 };
1121 struct sk_buff *msg;
1122 int err = -ENOMEM;
1123
1124 msg = nlmsg_new(rtnl_net_get_size(), gfp);
1125 if (!msg)
1126 goto out;
1127
1128 err = rtnl_net_fill(msg, &fillargs);
1129 if (err < 0)
1130 goto err_out;
1131
1132 rtnl_notify(msg, net, portid, RTNLGRP_NSID, nlh, gfp);
1133 return;
1134
1135err_out:
1136 nlmsg_free(msg);
1137out:
1138 rtnl_set_sk_err(net, RTNLGRP_NSID, err);
1139}
1140
1141#ifdef CONFIG_NET_NS
1142static void __init netns_ipv4_struct_check(void)
1143{
1144 /* TX readonly hotpath cache lines */
1145 CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_tx,
1146 sysctl_tcp_early_retrans);
1147 CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_tx,
1148 sysctl_tcp_tso_win_divisor);
1149 CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_tx,
1150 sysctl_tcp_tso_rtt_log);
1151 CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_tx,
1152 sysctl_tcp_autocorking);
1153 CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_tx,
1154 sysctl_tcp_min_snd_mss);
1155 CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_tx,
1156 sysctl_tcp_notsent_lowat);
1157 CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_tx,
1158 sysctl_tcp_limit_output_bytes);
1159 CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_tx,
1160 sysctl_tcp_min_rtt_wlen);
1161 CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_tx,
1162 sysctl_tcp_wmem);
1163 CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_tx,
1164 sysctl_ip_fwd_use_pmtu);
1165 CACHELINE_ASSERT_GROUP_SIZE(struct netns_ipv4, netns_ipv4_read_tx, 33);
1166
1167 /* TXRX readonly hotpath cache lines */
1168 CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_txrx,
1169 sysctl_tcp_moderate_rcvbuf);
1170 CACHELINE_ASSERT_GROUP_SIZE(struct netns_ipv4, netns_ipv4_read_txrx, 1);
1171
1172 /* RX readonly hotpath cache line */
1173 CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_rx,
1174 sysctl_ip_early_demux);
1175 CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_rx,
1176 sysctl_tcp_early_demux);
1177 CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_rx,
1178 sysctl_tcp_l3mdev_accept);
1179 CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_rx,
1180 sysctl_tcp_reordering);
1181 CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_rx,
1182 sysctl_tcp_rmem);
1183 CACHELINE_ASSERT_GROUP_SIZE(struct netns_ipv4, netns_ipv4_read_rx, 22);
1184}
1185#endif
1186
1187static const struct rtnl_msg_handler net_ns_rtnl_msg_handlers[] __initconst = {
1188 {.msgtype = RTM_NEWNSID, .doit = rtnl_net_newid,
1189 .flags = RTNL_FLAG_DOIT_UNLOCKED},
1190 {.msgtype = RTM_GETNSID, .doit = rtnl_net_getid,
1191 .dumpit = rtnl_net_dumpid,
1192 .flags = RTNL_FLAG_DOIT_UNLOCKED | RTNL_FLAG_DUMP_UNLOCKED},
1193};
1194
1195void __init net_ns_init(void)
1196{
1197 struct net_generic *ng;
1198
1199#ifdef CONFIG_NET_NS
1200 netns_ipv4_struct_check();
1201 net_cachep = kmem_cache_create("net_namespace", sizeof(struct net),
1202 SMP_CACHE_BYTES,
1203 SLAB_PANIC|SLAB_ACCOUNT, NULL);
1204
1205 /* Create workqueue for cleanup */
1206 netns_wq = create_singlethread_workqueue("netns");
1207 if (!netns_wq)
1208 panic("Could not create netns workq");
1209#endif
1210
1211 ng = net_alloc_generic();
1212 if (!ng)
1213 panic("Could not allocate generic netns");
1214
1215 rcu_assign_pointer(init_net.gen, ng);
1216
1217#ifdef CONFIG_KEYS
1218 init_net.key_domain = &init_net_key_domain;
1219#endif
1220 preinit_net(&init_net, &init_user_ns);
1221
1222 down_write(&pernet_ops_rwsem);
1223 if (setup_net(&init_net))
1224 panic("Could not setup the initial network namespace");
1225
1226 init_net_initialized = true;
1227 up_write(&pernet_ops_rwsem);
1228
1229 if (register_pernet_subsys(&net_ns_ops))
1230 panic("Could not register network namespace subsystems");
1231
1232 rtnl_register_many(net_ns_rtnl_msg_handlers);
1233}
1234
1235static void free_exit_list(struct pernet_operations *ops, struct list_head *net_exit_list)
1236{
1237 ops_pre_exit_list(ops, net_exit_list);
1238 synchronize_rcu();
1239
1240 if (ops->exit_batch_rtnl) {
1241 LIST_HEAD(dev_kill_list);
1242
1243 rtnl_lock();
1244 ops->exit_batch_rtnl(net_exit_list, &dev_kill_list);
1245 unregister_netdevice_many(&dev_kill_list);
1246 rtnl_unlock();
1247 }
1248 ops_exit_list(ops, net_exit_list);
1249
1250 ops_free_list(ops, net_exit_list);
1251}
1252
1253#ifdef CONFIG_NET_NS
1254static int __register_pernet_operations(struct list_head *list,
1255 struct pernet_operations *ops)
1256{
1257 struct net *net;
1258 int error;
1259 LIST_HEAD(net_exit_list);
1260
1261 list_add_tail(&ops->list, list);
1262 if (ops->init || ops->id) {
1263 /* We held write locked pernet_ops_rwsem, and parallel
1264 * setup_net() and cleanup_net() are not possible.
1265 */
1266 for_each_net(net) {
1267 error = ops_init(ops, net);
1268 if (error)
1269 goto out_undo;
1270 list_add_tail(&net->exit_list, &net_exit_list);
1271 }
1272 }
1273 return 0;
1274
1275out_undo:
1276 /* If I have an error cleanup all namespaces I initialized */
1277 list_del(&ops->list);
1278 free_exit_list(ops, &net_exit_list);
1279 return error;
1280}
1281
1282static void __unregister_pernet_operations(struct pernet_operations *ops)
1283{
1284 struct net *net;
1285 LIST_HEAD(net_exit_list);
1286
1287 list_del(&ops->list);
1288 /* See comment in __register_pernet_operations() */
1289 for_each_net(net)
1290 list_add_tail(&net->exit_list, &net_exit_list);
1291
1292 free_exit_list(ops, &net_exit_list);
1293}
1294
1295#else
1296
1297static int __register_pernet_operations(struct list_head *list,
1298 struct pernet_operations *ops)
1299{
1300 if (!init_net_initialized) {
1301 list_add_tail(&ops->list, list);
1302 return 0;
1303 }
1304
1305 return ops_init(ops, &init_net);
1306}
1307
1308static void __unregister_pernet_operations(struct pernet_operations *ops)
1309{
1310 if (!init_net_initialized) {
1311 list_del(&ops->list);
1312 } else {
1313 LIST_HEAD(net_exit_list);
1314 list_add(&init_net.exit_list, &net_exit_list);
1315 free_exit_list(ops, &net_exit_list);
1316 }
1317}
1318
1319#endif /* CONFIG_NET_NS */
1320
1321static DEFINE_IDA(net_generic_ids);
1322
1323static int register_pernet_operations(struct list_head *list,
1324 struct pernet_operations *ops)
1325{
1326 int error;
1327
1328 if (WARN_ON(!!ops->id ^ !!ops->size))
1329 return -EINVAL;
1330
1331 if (ops->id) {
1332 error = ida_alloc_min(&net_generic_ids, MIN_PERNET_OPS_ID,
1333 GFP_KERNEL);
1334 if (error < 0)
1335 return error;
1336 *ops->id = error;
1337 /* This does not require READ_ONCE as writers already hold
1338 * pernet_ops_rwsem. But WRITE_ONCE is needed to protect
1339 * net_alloc_generic.
1340 */
1341 WRITE_ONCE(max_gen_ptrs, max(max_gen_ptrs, *ops->id + 1));
1342 }
1343 error = __register_pernet_operations(list, ops);
1344 if (error) {
1345 rcu_barrier();
1346 if (ops->id)
1347 ida_free(&net_generic_ids, *ops->id);
1348 }
1349
1350 return error;
1351}
1352
1353static void unregister_pernet_operations(struct pernet_operations *ops)
1354{
1355 __unregister_pernet_operations(ops);
1356 rcu_barrier();
1357 if (ops->id)
1358 ida_free(&net_generic_ids, *ops->id);
1359}
1360
1361/**
1362 * register_pernet_subsys - register a network namespace subsystem
1363 * @ops: pernet operations structure for the subsystem
1364 *
1365 * Register a subsystem which has init and exit functions
1366 * that are called when network namespaces are created and
1367 * destroyed respectively.
1368 *
1369 * When registered all network namespace init functions are
1370 * called for every existing network namespace. Allowing kernel
1371 * modules to have a race free view of the set of network namespaces.
1372 *
1373 * When a new network namespace is created all of the init
1374 * methods are called in the order in which they were registered.
1375 *
1376 * When a network namespace is destroyed all of the exit methods
1377 * are called in the reverse of the order with which they were
1378 * registered.
1379 */
1380int register_pernet_subsys(struct pernet_operations *ops)
1381{
1382 int error;
1383 down_write(&pernet_ops_rwsem);
1384 error = register_pernet_operations(first_device, ops);
1385 up_write(&pernet_ops_rwsem);
1386 return error;
1387}
1388EXPORT_SYMBOL_GPL(register_pernet_subsys);
1389
1390/**
1391 * unregister_pernet_subsys - unregister a network namespace subsystem
1392 * @ops: pernet operations structure to manipulate
1393 *
1394 * Remove the pernet operations structure from the list to be
1395 * used when network namespaces are created or destroyed. In
1396 * addition run the exit method for all existing network
1397 * namespaces.
1398 */
1399void unregister_pernet_subsys(struct pernet_operations *ops)
1400{
1401 down_write(&pernet_ops_rwsem);
1402 unregister_pernet_operations(ops);
1403 up_write(&pernet_ops_rwsem);
1404}
1405EXPORT_SYMBOL_GPL(unregister_pernet_subsys);
1406
1407/**
1408 * register_pernet_device - register a network namespace device
1409 * @ops: pernet operations structure for the subsystem
1410 *
1411 * Register a device which has init and exit functions
1412 * that are called when network namespaces are created and
1413 * destroyed respectively.
1414 *
1415 * When registered all network namespace init functions are
1416 * called for every existing network namespace. Allowing kernel
1417 * modules to have a race free view of the set of network namespaces.
1418 *
1419 * When a new network namespace is created all of the init
1420 * methods are called in the order in which they were registered.
1421 *
1422 * When a network namespace is destroyed all of the exit methods
1423 * are called in the reverse of the order with which they were
1424 * registered.
1425 */
1426int register_pernet_device(struct pernet_operations *ops)
1427{
1428 int error;
1429 down_write(&pernet_ops_rwsem);
1430 error = register_pernet_operations(&pernet_list, ops);
1431 if (!error && (first_device == &pernet_list))
1432 first_device = &ops->list;
1433 up_write(&pernet_ops_rwsem);
1434 return error;
1435}
1436EXPORT_SYMBOL_GPL(register_pernet_device);
1437
1438/**
1439 * unregister_pernet_device - unregister a network namespace netdevice
1440 * @ops: pernet operations structure to manipulate
1441 *
1442 * Remove the pernet operations structure from the list to be
1443 * used when network namespaces are created or destroyed. In
1444 * addition run the exit method for all existing network
1445 * namespaces.
1446 */
1447void unregister_pernet_device(struct pernet_operations *ops)
1448{
1449 down_write(&pernet_ops_rwsem);
1450 if (&ops->list == first_device)
1451 first_device = first_device->next;
1452 unregister_pernet_operations(ops);
1453 up_write(&pernet_ops_rwsem);
1454}
1455EXPORT_SYMBOL_GPL(unregister_pernet_device);
1456
1457#ifdef CONFIG_NET_NS
1458static struct ns_common *netns_get(struct task_struct *task)
1459{
1460 struct net *net = NULL;
1461 struct nsproxy *nsproxy;
1462
1463 task_lock(task);
1464 nsproxy = task->nsproxy;
1465 if (nsproxy)
1466 net = get_net(nsproxy->net_ns);
1467 task_unlock(task);
1468
1469 return net ? &net->ns : NULL;
1470}
1471
1472static inline struct net *to_net_ns(struct ns_common *ns)
1473{
1474 return container_of(ns, struct net, ns);
1475}
1476
1477static void netns_put(struct ns_common *ns)
1478{
1479 put_net(to_net_ns(ns));
1480}
1481
1482static int netns_install(struct nsset *nsset, struct ns_common *ns)
1483{
1484 struct nsproxy *nsproxy = nsset->nsproxy;
1485 struct net *net = to_net_ns(ns);
1486
1487 if (!ns_capable(net->user_ns, CAP_SYS_ADMIN) ||
1488 !ns_capable(nsset->cred->user_ns, CAP_SYS_ADMIN))
1489 return -EPERM;
1490
1491 put_net(nsproxy->net_ns);
1492 nsproxy->net_ns = get_net(net);
1493 return 0;
1494}
1495
1496static struct user_namespace *netns_owner(struct ns_common *ns)
1497{
1498 return to_net_ns(ns)->user_ns;
1499}
1500
1501const struct proc_ns_operations netns_operations = {
1502 .name = "net",
1503 .type = CLONE_NEWNET,
1504 .get = netns_get,
1505 .put = netns_put,
1506 .install = netns_install,
1507 .owner = netns_owner,
1508};
1509#endif
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
23#include <net/sock.h>
24#include <net/netlink.h>
25#include <net/net_namespace.h>
26#include <net/netns/generic.h>
27
28/*
29 * Our network namespace constructor/destructor lists
30 */
31
32static LIST_HEAD(pernet_list);
33static struct list_head *first_device = &pernet_list;
34
35LIST_HEAD(net_namespace_list);
36EXPORT_SYMBOL_GPL(net_namespace_list);
37
38/* Protects net_namespace_list. Nests iside rtnl_lock() */
39DECLARE_RWSEM(net_rwsem);
40EXPORT_SYMBOL_GPL(net_rwsem);
41
42#ifdef CONFIG_KEYS
43static struct key_tag init_net_key_domain = { .usage = REFCOUNT_INIT(1) };
44#endif
45
46struct net init_net = {
47 .count = REFCOUNT_INIT(1),
48 .dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head),
49#ifdef CONFIG_KEYS
50 .key_domain = &init_net_key_domain,
51#endif
52};
53EXPORT_SYMBOL(init_net);
54
55static bool init_net_initialized;
56/*
57 * pernet_ops_rwsem: protects: pernet_list, net_generic_ids,
58 * init_net_initialized and first_device pointer.
59 * This is internal net namespace object. Please, don't use it
60 * outside.
61 */
62DECLARE_RWSEM(pernet_ops_rwsem);
63EXPORT_SYMBOL_GPL(pernet_ops_rwsem);
64
65#define MIN_PERNET_OPS_ID \
66 ((sizeof(struct net_generic) + sizeof(void *) - 1) / sizeof(void *))
67
68#define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */
69
70static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS;
71
72static atomic64_t cookie_gen;
73
74u64 net_gen_cookie(struct net *net)
75{
76 while (1) {
77 u64 res = atomic64_read(&net->net_cookie);
78
79 if (res)
80 return res;
81 res = atomic64_inc_return(&cookie_gen);
82 atomic64_cmpxchg(&net->net_cookie, 0, res);
83 }
84}
85
86static struct net_generic *net_alloc_generic(void)
87{
88 struct net_generic *ng;
89 unsigned int generic_size = offsetof(struct net_generic, ptr[max_gen_ptrs]);
90
91 ng = kzalloc(generic_size, GFP_KERNEL);
92 if (ng)
93 ng->s.len = max_gen_ptrs;
94
95 return ng;
96}
97
98static int net_assign_generic(struct net *net, unsigned int id, void *data)
99{
100 struct net_generic *ng, *old_ng;
101
102 BUG_ON(id < MIN_PERNET_OPS_ID);
103
104 old_ng = rcu_dereference_protected(net->gen,
105 lockdep_is_held(&pernet_ops_rwsem));
106 if (old_ng->s.len > id) {
107 old_ng->ptr[id] = data;
108 return 0;
109 }
110
111 ng = net_alloc_generic();
112 if (ng == NULL)
113 return -ENOMEM;
114
115 /*
116 * Some synchronisation notes:
117 *
118 * The net_generic explores the net->gen array inside rcu
119 * read section. Besides once set the net->gen->ptr[x]
120 * pointer never changes (see rules in netns/generic.h).
121 *
122 * That said, we simply duplicate this array and schedule
123 * the old copy for kfree after a grace period.
124 */
125
126 memcpy(&ng->ptr[MIN_PERNET_OPS_ID], &old_ng->ptr[MIN_PERNET_OPS_ID],
127 (old_ng->s.len - MIN_PERNET_OPS_ID) * sizeof(void *));
128 ng->ptr[id] = data;
129
130 rcu_assign_pointer(net->gen, ng);
131 kfree_rcu(old_ng, s.rcu);
132 return 0;
133}
134
135static int ops_init(const struct pernet_operations *ops, struct net *net)
136{
137 int err = -ENOMEM;
138 void *data = NULL;
139
140 if (ops->id && ops->size) {
141 data = kzalloc(ops->size, GFP_KERNEL);
142 if (!data)
143 goto out;
144
145 err = net_assign_generic(net, *ops->id, data);
146 if (err)
147 goto cleanup;
148 }
149 err = 0;
150 if (ops->init)
151 err = ops->init(net);
152 if (!err)
153 return 0;
154
155cleanup:
156 kfree(data);
157
158out:
159 return err;
160}
161
162static void ops_free(const struct pernet_operations *ops, struct net *net)
163{
164 if (ops->id && ops->size) {
165 kfree(net_generic(net, *ops->id));
166 }
167}
168
169static void ops_pre_exit_list(const struct pernet_operations *ops,
170 struct list_head *net_exit_list)
171{
172 struct net *net;
173
174 if (ops->pre_exit) {
175 list_for_each_entry(net, net_exit_list, exit_list)
176 ops->pre_exit(net);
177 }
178}
179
180static void ops_exit_list(const struct pernet_operations *ops,
181 struct list_head *net_exit_list)
182{
183 struct net *net;
184 if (ops->exit) {
185 list_for_each_entry(net, net_exit_list, exit_list)
186 ops->exit(net);
187 }
188 if (ops->exit_batch)
189 ops->exit_batch(net_exit_list);
190}
191
192static void ops_free_list(const struct pernet_operations *ops,
193 struct list_head *net_exit_list)
194{
195 struct net *net;
196 if (ops->size && ops->id) {
197 list_for_each_entry(net, net_exit_list, exit_list)
198 ops_free(ops, net);
199 }
200}
201
202/* should be called with nsid_lock held */
203static int alloc_netid(struct net *net, struct net *peer, int reqid)
204{
205 int min = 0, max = 0;
206
207 if (reqid >= 0) {
208 min = reqid;
209 max = reqid + 1;
210 }
211
212 return idr_alloc(&net->netns_ids, peer, min, max, GFP_ATOMIC);
213}
214
215/* This function is used by idr_for_each(). If net is equal to peer, the
216 * function returns the id so that idr_for_each() stops. Because we cannot
217 * returns the id 0 (idr_for_each() will not stop), we return the magic value
218 * NET_ID_ZERO (-1) for it.
219 */
220#define NET_ID_ZERO -1
221static int net_eq_idr(int id, void *net, void *peer)
222{
223 if (net_eq(net, peer))
224 return id ? : NET_ID_ZERO;
225 return 0;
226}
227
228/* Must be called from RCU-critical section or with nsid_lock held */
229static int __peernet2id(const struct net *net, struct net *peer)
230{
231 int id = idr_for_each(&net->netns_ids, net_eq_idr, peer);
232
233 /* Magic value for id 0. */
234 if (id == NET_ID_ZERO)
235 return 0;
236 if (id > 0)
237 return id;
238
239 return NETNSA_NSID_NOT_ASSIGNED;
240}
241
242static void rtnl_net_notifyid(struct net *net, int cmd, int id, u32 portid,
243 struct nlmsghdr *nlh, gfp_t gfp);
244/* This function returns the id of a peer netns. If no id is assigned, one will
245 * be allocated and returned.
246 */
247int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp)
248{
249 int id;
250
251 if (refcount_read(&net->count) == 0)
252 return NETNSA_NSID_NOT_ASSIGNED;
253
254 spin_lock_bh(&net->nsid_lock);
255 id = __peernet2id(net, peer);
256 if (id >= 0) {
257 spin_unlock_bh(&net->nsid_lock);
258 return id;
259 }
260
261 /* When peer is obtained from RCU lists, we may race with
262 * its cleanup. Check whether it's alive, and this guarantees
263 * we never hash a peer back to net->netns_ids, after it has
264 * just been idr_remove()'d from there in cleanup_net().
265 */
266 if (!maybe_get_net(peer)) {
267 spin_unlock_bh(&net->nsid_lock);
268 return NETNSA_NSID_NOT_ASSIGNED;
269 }
270
271 id = alloc_netid(net, peer, -1);
272 spin_unlock_bh(&net->nsid_lock);
273
274 put_net(peer);
275 if (id < 0)
276 return NETNSA_NSID_NOT_ASSIGNED;
277
278 rtnl_net_notifyid(net, RTM_NEWNSID, id, 0, NULL, gfp);
279
280 return id;
281}
282EXPORT_SYMBOL_GPL(peernet2id_alloc);
283
284/* This function returns, if assigned, the id of a peer netns. */
285int peernet2id(const struct net *net, struct net *peer)
286{
287 int id;
288
289 rcu_read_lock();
290 id = __peernet2id(net, peer);
291 rcu_read_unlock();
292
293 return id;
294}
295EXPORT_SYMBOL(peernet2id);
296
297/* This function returns true is the peer netns has an id assigned into the
298 * current netns.
299 */
300bool peernet_has_id(const struct net *net, struct net *peer)
301{
302 return peernet2id(net, peer) >= 0;
303}
304
305struct net *get_net_ns_by_id(const struct net *net, int id)
306{
307 struct net *peer;
308
309 if (id < 0)
310 return NULL;
311
312 rcu_read_lock();
313 peer = idr_find(&net->netns_ids, id);
314 if (peer)
315 peer = maybe_get_net(peer);
316 rcu_read_unlock();
317
318 return peer;
319}
320
321/*
322 * setup_net runs the initializers for the network namespace object.
323 */
324static __net_init int setup_net(struct net *net, struct user_namespace *user_ns)
325{
326 /* Must be called with pernet_ops_rwsem held */
327 const struct pernet_operations *ops, *saved_ops;
328 int error = 0;
329 LIST_HEAD(net_exit_list);
330
331 refcount_set(&net->count, 1);
332 refcount_set(&net->passive, 1);
333 get_random_bytes(&net->hash_mix, sizeof(u32));
334 net->dev_base_seq = 1;
335 net->user_ns = user_ns;
336 idr_init(&net->netns_ids);
337 spin_lock_init(&net->nsid_lock);
338 mutex_init(&net->ipv4.ra_mutex);
339
340 list_for_each_entry(ops, &pernet_list, list) {
341 error = ops_init(ops, net);
342 if (error < 0)
343 goto out_undo;
344 }
345 down_write(&net_rwsem);
346 list_add_tail_rcu(&net->list, &net_namespace_list);
347 up_write(&net_rwsem);
348out:
349 return error;
350
351out_undo:
352 /* Walk through the list backwards calling the exit functions
353 * for the pernet modules whose init functions did not fail.
354 */
355 list_add(&net->exit_list, &net_exit_list);
356 saved_ops = ops;
357 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
358 ops_pre_exit_list(ops, &net_exit_list);
359
360 synchronize_rcu();
361
362 ops = saved_ops;
363 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
364 ops_exit_list(ops, &net_exit_list);
365
366 ops = saved_ops;
367 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
368 ops_free_list(ops, &net_exit_list);
369
370 rcu_barrier();
371 goto out;
372}
373
374static int __net_init net_defaults_init_net(struct net *net)
375{
376 net->core.sysctl_somaxconn = SOMAXCONN;
377 return 0;
378}
379
380static struct pernet_operations net_defaults_ops = {
381 .init = net_defaults_init_net,
382};
383
384static __init int net_defaults_init(void)
385{
386 if (register_pernet_subsys(&net_defaults_ops))
387 panic("Cannot initialize net default settings");
388
389 return 0;
390}
391
392core_initcall(net_defaults_init);
393
394#ifdef CONFIG_NET_NS
395static struct ucounts *inc_net_namespaces(struct user_namespace *ns)
396{
397 return inc_ucount(ns, current_euid(), UCOUNT_NET_NAMESPACES);
398}
399
400static void dec_net_namespaces(struct ucounts *ucounts)
401{
402 dec_ucount(ucounts, UCOUNT_NET_NAMESPACES);
403}
404
405static struct kmem_cache *net_cachep __ro_after_init;
406static struct workqueue_struct *netns_wq;
407
408static struct net *net_alloc(void)
409{
410 struct net *net = NULL;
411 struct net_generic *ng;
412
413 ng = net_alloc_generic();
414 if (!ng)
415 goto out;
416
417 net = kmem_cache_zalloc(net_cachep, GFP_KERNEL);
418 if (!net)
419 goto out_free;
420
421#ifdef CONFIG_KEYS
422 net->key_domain = kzalloc(sizeof(struct key_tag), GFP_KERNEL);
423 if (!net->key_domain)
424 goto out_free_2;
425 refcount_set(&net->key_domain->usage, 1);
426#endif
427
428 rcu_assign_pointer(net->gen, ng);
429out:
430 return net;
431
432#ifdef CONFIG_KEYS
433out_free_2:
434 kmem_cache_free(net_cachep, net);
435 net = NULL;
436#endif
437out_free:
438 kfree(ng);
439 goto out;
440}
441
442static void net_free(struct net *net)
443{
444 kfree(rcu_access_pointer(net->gen));
445 kmem_cache_free(net_cachep, net);
446}
447
448void net_drop_ns(void *p)
449{
450 struct net *ns = p;
451 if (ns && refcount_dec_and_test(&ns->passive))
452 net_free(ns);
453}
454
455struct net *copy_net_ns(unsigned long flags,
456 struct user_namespace *user_ns, struct net *old_net)
457{
458 struct ucounts *ucounts;
459 struct net *net;
460 int rv;
461
462 if (!(flags & CLONE_NEWNET))
463 return get_net(old_net);
464
465 ucounts = inc_net_namespaces(user_ns);
466 if (!ucounts)
467 return ERR_PTR(-ENOSPC);
468
469 net = net_alloc();
470 if (!net) {
471 rv = -ENOMEM;
472 goto dec_ucounts;
473 }
474 refcount_set(&net->passive, 1);
475 net->ucounts = ucounts;
476 get_user_ns(user_ns);
477
478 rv = down_read_killable(&pernet_ops_rwsem);
479 if (rv < 0)
480 goto put_userns;
481
482 rv = setup_net(net, user_ns);
483
484 up_read(&pernet_ops_rwsem);
485
486 if (rv < 0) {
487put_userns:
488 key_remove_domain(net->key_domain);
489 put_user_ns(user_ns);
490 net_drop_ns(net);
491dec_ucounts:
492 dec_net_namespaces(ucounts);
493 return ERR_PTR(rv);
494 }
495 return net;
496}
497
498/**
499 * net_ns_get_ownership - get sysfs ownership data for @net
500 * @net: network namespace in question (can be NULL)
501 * @uid: kernel user ID for sysfs objects
502 * @gid: kernel group ID for sysfs objects
503 *
504 * Returns the uid/gid pair of root in the user namespace associated with the
505 * given network namespace.
506 */
507void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid)
508{
509 if (net) {
510 kuid_t ns_root_uid = make_kuid(net->user_ns, 0);
511 kgid_t ns_root_gid = make_kgid(net->user_ns, 0);
512
513 if (uid_valid(ns_root_uid))
514 *uid = ns_root_uid;
515
516 if (gid_valid(ns_root_gid))
517 *gid = ns_root_gid;
518 } else {
519 *uid = GLOBAL_ROOT_UID;
520 *gid = GLOBAL_ROOT_GID;
521 }
522}
523EXPORT_SYMBOL_GPL(net_ns_get_ownership);
524
525static void unhash_nsid(struct net *net, struct net *last)
526{
527 struct net *tmp;
528 /* This function is only called from cleanup_net() work,
529 * and this work is the only process, that may delete
530 * a net from net_namespace_list. So, when the below
531 * is executing, the list may only grow. Thus, we do not
532 * use for_each_net_rcu() or net_rwsem.
533 */
534 for_each_net(tmp) {
535 int id;
536
537 spin_lock_bh(&tmp->nsid_lock);
538 id = __peernet2id(tmp, net);
539 if (id >= 0)
540 idr_remove(&tmp->netns_ids, id);
541 spin_unlock_bh(&tmp->nsid_lock);
542 if (id >= 0)
543 rtnl_net_notifyid(tmp, RTM_DELNSID, id, 0, NULL,
544 GFP_KERNEL);
545 if (tmp == last)
546 break;
547 }
548 spin_lock_bh(&net->nsid_lock);
549 idr_destroy(&net->netns_ids);
550 spin_unlock_bh(&net->nsid_lock);
551}
552
553static LLIST_HEAD(cleanup_list);
554
555static void cleanup_net(struct work_struct *work)
556{
557 const struct pernet_operations *ops;
558 struct net *net, *tmp, *last;
559 struct llist_node *net_kill_list;
560 LIST_HEAD(net_exit_list);
561
562 /* Atomically snapshot the list of namespaces to cleanup */
563 net_kill_list = llist_del_all(&cleanup_list);
564
565 down_read(&pernet_ops_rwsem);
566
567 /* Don't let anyone else find us. */
568 down_write(&net_rwsem);
569 llist_for_each_entry(net, net_kill_list, cleanup_list)
570 list_del_rcu(&net->list);
571 /* Cache last net. After we unlock rtnl, no one new net
572 * added to net_namespace_list can assign nsid pointer
573 * to a net from net_kill_list (see peernet2id_alloc()).
574 * So, we skip them in unhash_nsid().
575 *
576 * Note, that unhash_nsid() does not delete nsid links
577 * between net_kill_list's nets, as they've already
578 * deleted from net_namespace_list. But, this would be
579 * useless anyway, as netns_ids are destroyed there.
580 */
581 last = list_last_entry(&net_namespace_list, struct net, list);
582 up_write(&net_rwsem);
583
584 llist_for_each_entry(net, net_kill_list, cleanup_list) {
585 unhash_nsid(net, last);
586 list_add_tail(&net->exit_list, &net_exit_list);
587 }
588
589 /* Run all of the network namespace pre_exit methods */
590 list_for_each_entry_reverse(ops, &pernet_list, list)
591 ops_pre_exit_list(ops, &net_exit_list);
592
593 /*
594 * Another CPU might be rcu-iterating the list, wait for it.
595 * This needs to be before calling the exit() notifiers, so
596 * the rcu_barrier() below isn't sufficient alone.
597 * Also the pre_exit() and exit() methods need this barrier.
598 */
599 synchronize_rcu();
600
601 /* Run all of the network namespace exit methods */
602 list_for_each_entry_reverse(ops, &pernet_list, list)
603 ops_exit_list(ops, &net_exit_list);
604
605 /* Free the net generic variables */
606 list_for_each_entry_reverse(ops, &pernet_list, list)
607 ops_free_list(ops, &net_exit_list);
608
609 up_read(&pernet_ops_rwsem);
610
611 /* Ensure there are no outstanding rcu callbacks using this
612 * network namespace.
613 */
614 rcu_barrier();
615
616 /* Finally it is safe to free my network namespace structure */
617 list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
618 list_del_init(&net->exit_list);
619 dec_net_namespaces(net->ucounts);
620 key_remove_domain(net->key_domain);
621 put_user_ns(net->user_ns);
622 net_drop_ns(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 */
635void net_ns_barrier(void)
636{
637 down_write(&pernet_ops_rwsem);
638 up_write(&pernet_ops_rwsem);
639}
640EXPORT_SYMBOL(net_ns_barrier);
641
642static DECLARE_WORK(net_cleanup_work, cleanup_net);
643
644void __put_net(struct net *net)
645{
646 /* Cleanup the network namespace in process context */
647 if (llist_add(&net->cleanup_list, &cleanup_list))
648 queue_work(netns_wq, &net_cleanup_work);
649}
650EXPORT_SYMBOL_GPL(__put_net);
651
652struct net *get_net_ns_by_fd(int fd)
653{
654 struct file *file;
655 struct ns_common *ns;
656 struct net *net;
657
658 file = proc_ns_fget(fd);
659 if (IS_ERR(file))
660 return ERR_CAST(file);
661
662 ns = get_proc_ns(file_inode(file));
663 if (ns->ops == &netns_operations)
664 net = get_net(container_of(ns, struct net, ns));
665 else
666 net = ERR_PTR(-EINVAL);
667
668 fput(file);
669 return net;
670}
671
672#else
673struct net *get_net_ns_by_fd(int fd)
674{
675 return ERR_PTR(-EINVAL);
676}
677#endif
678EXPORT_SYMBOL_GPL(get_net_ns_by_fd);
679
680struct net *get_net_ns_by_pid(pid_t pid)
681{
682 struct task_struct *tsk;
683 struct net *net;
684
685 /* Lookup the network namespace */
686 net = ERR_PTR(-ESRCH);
687 rcu_read_lock();
688 tsk = find_task_by_vpid(pid);
689 if (tsk) {
690 struct nsproxy *nsproxy;
691 task_lock(tsk);
692 nsproxy = tsk->nsproxy;
693 if (nsproxy)
694 net = get_net(nsproxy->net_ns);
695 task_unlock(tsk);
696 }
697 rcu_read_unlock();
698 return net;
699}
700EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
701
702static __net_init int net_ns_net_init(struct net *net)
703{
704#ifdef CONFIG_NET_NS
705 net->ns.ops = &netns_operations;
706#endif
707 return ns_alloc_inum(&net->ns);
708}
709
710static __net_exit void net_ns_net_exit(struct net *net)
711{
712 ns_free_inum(&net->ns);
713}
714
715static struct pernet_operations __net_initdata net_ns_ops = {
716 .init = net_ns_net_init,
717 .exit = net_ns_net_exit,
718};
719
720static const struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = {
721 [NETNSA_NONE] = { .type = NLA_UNSPEC },
722 [NETNSA_NSID] = { .type = NLA_S32 },
723 [NETNSA_PID] = { .type = NLA_U32 },
724 [NETNSA_FD] = { .type = NLA_U32 },
725 [NETNSA_TARGET_NSID] = { .type = NLA_S32 },
726};
727
728static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh,
729 struct netlink_ext_ack *extack)
730{
731 struct net *net = sock_net(skb->sk);
732 struct nlattr *tb[NETNSA_MAX + 1];
733 struct nlattr *nla;
734 struct net *peer;
735 int nsid, err;
736
737 err = nlmsg_parse_deprecated(nlh, sizeof(struct rtgenmsg), tb,
738 NETNSA_MAX, rtnl_net_policy, extack);
739 if (err < 0)
740 return err;
741 if (!tb[NETNSA_NSID]) {
742 NL_SET_ERR_MSG(extack, "nsid is missing");
743 return -EINVAL;
744 }
745 nsid = nla_get_s32(tb[NETNSA_NSID]);
746
747 if (tb[NETNSA_PID]) {
748 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
749 nla = tb[NETNSA_PID];
750 } else if (tb[NETNSA_FD]) {
751 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
752 nla = tb[NETNSA_FD];
753 } else {
754 NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
755 return -EINVAL;
756 }
757 if (IS_ERR(peer)) {
758 NL_SET_BAD_ATTR(extack, nla);
759 NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
760 return PTR_ERR(peer);
761 }
762
763 spin_lock_bh(&net->nsid_lock);
764 if (__peernet2id(net, peer) >= 0) {
765 spin_unlock_bh(&net->nsid_lock);
766 err = -EEXIST;
767 NL_SET_BAD_ATTR(extack, nla);
768 NL_SET_ERR_MSG(extack,
769 "Peer netns already has a nsid assigned");
770 goto out;
771 }
772
773 err = alloc_netid(net, peer, nsid);
774 spin_unlock_bh(&net->nsid_lock);
775 if (err >= 0) {
776 rtnl_net_notifyid(net, RTM_NEWNSID, err, NETLINK_CB(skb).portid,
777 nlh, GFP_KERNEL);
778 err = 0;
779 } else if (err == -ENOSPC && nsid >= 0) {
780 err = -EEXIST;
781 NL_SET_BAD_ATTR(extack, tb[NETNSA_NSID]);
782 NL_SET_ERR_MSG(extack, "The specified nsid is already used");
783 }
784out:
785 put_net(peer);
786 return err;
787}
788
789static int rtnl_net_get_size(void)
790{
791 return NLMSG_ALIGN(sizeof(struct rtgenmsg))
792 + nla_total_size(sizeof(s32)) /* NETNSA_NSID */
793 + nla_total_size(sizeof(s32)) /* NETNSA_CURRENT_NSID */
794 ;
795}
796
797struct net_fill_args {
798 u32 portid;
799 u32 seq;
800 int flags;
801 int cmd;
802 int nsid;
803 bool add_ref;
804 int ref_nsid;
805};
806
807static int rtnl_net_fill(struct sk_buff *skb, struct net_fill_args *args)
808{
809 struct nlmsghdr *nlh;
810 struct rtgenmsg *rth;
811
812 nlh = nlmsg_put(skb, args->portid, args->seq, args->cmd, sizeof(*rth),
813 args->flags);
814 if (!nlh)
815 return -EMSGSIZE;
816
817 rth = nlmsg_data(nlh);
818 rth->rtgen_family = AF_UNSPEC;
819
820 if (nla_put_s32(skb, NETNSA_NSID, args->nsid))
821 goto nla_put_failure;
822
823 if (args->add_ref &&
824 nla_put_s32(skb, NETNSA_CURRENT_NSID, args->ref_nsid))
825 goto nla_put_failure;
826
827 nlmsg_end(skb, nlh);
828 return 0;
829
830nla_put_failure:
831 nlmsg_cancel(skb, nlh);
832 return -EMSGSIZE;
833}
834
835static int rtnl_net_valid_getid_req(struct sk_buff *skb,
836 const struct nlmsghdr *nlh,
837 struct nlattr **tb,
838 struct netlink_ext_ack *extack)
839{
840 int i, err;
841
842 if (!netlink_strict_get_check(skb))
843 return nlmsg_parse_deprecated(nlh, sizeof(struct rtgenmsg),
844 tb, NETNSA_MAX, rtnl_net_policy,
845 extack);
846
847 err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct rtgenmsg), tb,
848 NETNSA_MAX, rtnl_net_policy,
849 extack);
850 if (err)
851 return err;
852
853 for (i = 0; i <= NETNSA_MAX; i++) {
854 if (!tb[i])
855 continue;
856
857 switch (i) {
858 case NETNSA_PID:
859 case NETNSA_FD:
860 case NETNSA_NSID:
861 case NETNSA_TARGET_NSID:
862 break;
863 default:
864 NL_SET_ERR_MSG(extack, "Unsupported attribute in peer netns getid request");
865 return -EINVAL;
866 }
867 }
868
869 return 0;
870}
871
872static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh,
873 struct netlink_ext_ack *extack)
874{
875 struct net *net = sock_net(skb->sk);
876 struct nlattr *tb[NETNSA_MAX + 1];
877 struct net_fill_args fillargs = {
878 .portid = NETLINK_CB(skb).portid,
879 .seq = nlh->nlmsg_seq,
880 .cmd = RTM_NEWNSID,
881 };
882 struct net *peer, *target = net;
883 struct nlattr *nla;
884 struct sk_buff *msg;
885 int err;
886
887 err = rtnl_net_valid_getid_req(skb, nlh, tb, extack);
888 if (err < 0)
889 return err;
890 if (tb[NETNSA_PID]) {
891 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
892 nla = tb[NETNSA_PID];
893 } else if (tb[NETNSA_FD]) {
894 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
895 nla = tb[NETNSA_FD];
896 } else if (tb[NETNSA_NSID]) {
897 peer = get_net_ns_by_id(net, nla_get_s32(tb[NETNSA_NSID]));
898 if (!peer)
899 peer = ERR_PTR(-ENOENT);
900 nla = tb[NETNSA_NSID];
901 } else {
902 NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
903 return -EINVAL;
904 }
905
906 if (IS_ERR(peer)) {
907 NL_SET_BAD_ATTR(extack, nla);
908 NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
909 return PTR_ERR(peer);
910 }
911
912 if (tb[NETNSA_TARGET_NSID]) {
913 int id = nla_get_s32(tb[NETNSA_TARGET_NSID]);
914
915 target = rtnl_get_net_ns_capable(NETLINK_CB(skb).sk, id);
916 if (IS_ERR(target)) {
917 NL_SET_BAD_ATTR(extack, tb[NETNSA_TARGET_NSID]);
918 NL_SET_ERR_MSG(extack,
919 "Target netns reference is invalid");
920 err = PTR_ERR(target);
921 goto out;
922 }
923 fillargs.add_ref = true;
924 fillargs.ref_nsid = peernet2id(net, peer);
925 }
926
927 msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
928 if (!msg) {
929 err = -ENOMEM;
930 goto out;
931 }
932
933 fillargs.nsid = peernet2id(target, peer);
934 err = rtnl_net_fill(msg, &fillargs);
935 if (err < 0)
936 goto err_out;
937
938 err = rtnl_unicast(msg, net, NETLINK_CB(skb).portid);
939 goto out;
940
941err_out:
942 nlmsg_free(msg);
943out:
944 if (fillargs.add_ref)
945 put_net(target);
946 put_net(peer);
947 return err;
948}
949
950struct rtnl_net_dump_cb {
951 struct net *tgt_net;
952 struct net *ref_net;
953 struct sk_buff *skb;
954 struct net_fill_args fillargs;
955 int idx;
956 int s_idx;
957};
958
959/* Runs in RCU-critical section. */
960static int rtnl_net_dumpid_one(int id, void *peer, void *data)
961{
962 struct rtnl_net_dump_cb *net_cb = (struct rtnl_net_dump_cb *)data;
963 int ret;
964
965 if (net_cb->idx < net_cb->s_idx)
966 goto cont;
967
968 net_cb->fillargs.nsid = id;
969 if (net_cb->fillargs.add_ref)
970 net_cb->fillargs.ref_nsid = __peernet2id(net_cb->ref_net, peer);
971 ret = rtnl_net_fill(net_cb->skb, &net_cb->fillargs);
972 if (ret < 0)
973 return ret;
974
975cont:
976 net_cb->idx++;
977 return 0;
978}
979
980static int rtnl_valid_dump_net_req(const struct nlmsghdr *nlh, struct sock *sk,
981 struct rtnl_net_dump_cb *net_cb,
982 struct netlink_callback *cb)
983{
984 struct netlink_ext_ack *extack = cb->extack;
985 struct nlattr *tb[NETNSA_MAX + 1];
986 int err, i;
987
988 err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct rtgenmsg), tb,
989 NETNSA_MAX, rtnl_net_policy,
990 extack);
991 if (err < 0)
992 return err;
993
994 for (i = 0; i <= NETNSA_MAX; i++) {
995 if (!tb[i])
996 continue;
997
998 if (i == NETNSA_TARGET_NSID) {
999 struct net *net;
1000
1001 net = rtnl_get_net_ns_capable(sk, nla_get_s32(tb[i]));
1002 if (IS_ERR(net)) {
1003 NL_SET_BAD_ATTR(extack, tb[i]);
1004 NL_SET_ERR_MSG(extack,
1005 "Invalid target network namespace id");
1006 return PTR_ERR(net);
1007 }
1008 net_cb->fillargs.add_ref = true;
1009 net_cb->ref_net = net_cb->tgt_net;
1010 net_cb->tgt_net = net;
1011 } else {
1012 NL_SET_BAD_ATTR(extack, tb[i]);
1013 NL_SET_ERR_MSG(extack,
1014 "Unsupported attribute in dump request");
1015 return -EINVAL;
1016 }
1017 }
1018
1019 return 0;
1020}
1021
1022static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb)
1023{
1024 struct rtnl_net_dump_cb net_cb = {
1025 .tgt_net = sock_net(skb->sk),
1026 .skb = skb,
1027 .fillargs = {
1028 .portid = NETLINK_CB(cb->skb).portid,
1029 .seq = cb->nlh->nlmsg_seq,
1030 .flags = NLM_F_MULTI,
1031 .cmd = RTM_NEWNSID,
1032 },
1033 .idx = 0,
1034 .s_idx = cb->args[0],
1035 };
1036 int err = 0;
1037
1038 if (cb->strict_check) {
1039 err = rtnl_valid_dump_net_req(cb->nlh, skb->sk, &net_cb, cb);
1040 if (err < 0)
1041 goto end;
1042 }
1043
1044 rcu_read_lock();
1045 idr_for_each(&net_cb.tgt_net->netns_ids, rtnl_net_dumpid_one, &net_cb);
1046 rcu_read_unlock();
1047
1048 cb->args[0] = net_cb.idx;
1049end:
1050 if (net_cb.fillargs.add_ref)
1051 put_net(net_cb.tgt_net);
1052 return err < 0 ? err : skb->len;
1053}
1054
1055static void rtnl_net_notifyid(struct net *net, int cmd, int id, u32 portid,
1056 struct nlmsghdr *nlh, gfp_t gfp)
1057{
1058 struct net_fill_args fillargs = {
1059 .portid = portid,
1060 .seq = nlh ? nlh->nlmsg_seq : 0,
1061 .cmd = cmd,
1062 .nsid = id,
1063 };
1064 struct sk_buff *msg;
1065 int err = -ENOMEM;
1066
1067 msg = nlmsg_new(rtnl_net_get_size(), gfp);
1068 if (!msg)
1069 goto out;
1070
1071 err = rtnl_net_fill(msg, &fillargs);
1072 if (err < 0)
1073 goto err_out;
1074
1075 rtnl_notify(msg, net, portid, RTNLGRP_NSID, nlh, gfp);
1076 return;
1077
1078err_out:
1079 nlmsg_free(msg);
1080out:
1081 rtnl_set_sk_err(net, RTNLGRP_NSID, err);
1082}
1083
1084static int __init net_ns_init(void)
1085{
1086 struct net_generic *ng;
1087
1088#ifdef CONFIG_NET_NS
1089 net_cachep = kmem_cache_create("net_namespace", sizeof(struct net),
1090 SMP_CACHE_BYTES,
1091 SLAB_PANIC|SLAB_ACCOUNT, NULL);
1092
1093 /* Create workqueue for cleanup */
1094 netns_wq = create_singlethread_workqueue("netns");
1095 if (!netns_wq)
1096 panic("Could not create netns workq");
1097#endif
1098
1099 ng = net_alloc_generic();
1100 if (!ng)
1101 panic("Could not allocate generic netns");
1102
1103 rcu_assign_pointer(init_net.gen, ng);
1104 net_gen_cookie(&init_net);
1105
1106 down_write(&pernet_ops_rwsem);
1107 if (setup_net(&init_net, &init_user_ns))
1108 panic("Could not setup the initial network namespace");
1109
1110 init_net_initialized = true;
1111 up_write(&pernet_ops_rwsem);
1112
1113 if (register_pernet_subsys(&net_ns_ops))
1114 panic("Could not register network namespace subsystems");
1115
1116 rtnl_register(PF_UNSPEC, RTM_NEWNSID, rtnl_net_newid, NULL,
1117 RTNL_FLAG_DOIT_UNLOCKED);
1118 rtnl_register(PF_UNSPEC, RTM_GETNSID, rtnl_net_getid, rtnl_net_dumpid,
1119 RTNL_FLAG_DOIT_UNLOCKED);
1120
1121 return 0;
1122}
1123
1124pure_initcall(net_ns_init);
1125
1126#ifdef CONFIG_NET_NS
1127static int __register_pernet_operations(struct list_head *list,
1128 struct pernet_operations *ops)
1129{
1130 struct net *net;
1131 int error;
1132 LIST_HEAD(net_exit_list);
1133
1134 list_add_tail(&ops->list, list);
1135 if (ops->init || (ops->id && ops->size)) {
1136 /* We held write locked pernet_ops_rwsem, and parallel
1137 * setup_net() and cleanup_net() are not possible.
1138 */
1139 for_each_net(net) {
1140 error = ops_init(ops, net);
1141 if (error)
1142 goto out_undo;
1143 list_add_tail(&net->exit_list, &net_exit_list);
1144 }
1145 }
1146 return 0;
1147
1148out_undo:
1149 /* If I have an error cleanup all namespaces I initialized */
1150 list_del(&ops->list);
1151 ops_pre_exit_list(ops, &net_exit_list);
1152 synchronize_rcu();
1153 ops_exit_list(ops, &net_exit_list);
1154 ops_free_list(ops, &net_exit_list);
1155 return error;
1156}
1157
1158static void __unregister_pernet_operations(struct pernet_operations *ops)
1159{
1160 struct net *net;
1161 LIST_HEAD(net_exit_list);
1162
1163 list_del(&ops->list);
1164 /* See comment in __register_pernet_operations() */
1165 for_each_net(net)
1166 list_add_tail(&net->exit_list, &net_exit_list);
1167 ops_pre_exit_list(ops, &net_exit_list);
1168 synchronize_rcu();
1169 ops_exit_list(ops, &net_exit_list);
1170 ops_free_list(ops, &net_exit_list);
1171}
1172
1173#else
1174
1175static int __register_pernet_operations(struct list_head *list,
1176 struct pernet_operations *ops)
1177{
1178 if (!init_net_initialized) {
1179 list_add_tail(&ops->list, list);
1180 return 0;
1181 }
1182
1183 return ops_init(ops, &init_net);
1184}
1185
1186static void __unregister_pernet_operations(struct pernet_operations *ops)
1187{
1188 if (!init_net_initialized) {
1189 list_del(&ops->list);
1190 } else {
1191 LIST_HEAD(net_exit_list);
1192 list_add(&init_net.exit_list, &net_exit_list);
1193 ops_pre_exit_list(ops, &net_exit_list);
1194 synchronize_rcu();
1195 ops_exit_list(ops, &net_exit_list);
1196 ops_free_list(ops, &net_exit_list);
1197 }
1198}
1199
1200#endif /* CONFIG_NET_NS */
1201
1202static DEFINE_IDA(net_generic_ids);
1203
1204static int register_pernet_operations(struct list_head *list,
1205 struct pernet_operations *ops)
1206{
1207 int error;
1208
1209 if (ops->id) {
1210 error = ida_alloc_min(&net_generic_ids, MIN_PERNET_OPS_ID,
1211 GFP_KERNEL);
1212 if (error < 0)
1213 return error;
1214 *ops->id = error;
1215 max_gen_ptrs = max(max_gen_ptrs, *ops->id + 1);
1216 }
1217 error = __register_pernet_operations(list, ops);
1218 if (error) {
1219 rcu_barrier();
1220 if (ops->id)
1221 ida_free(&net_generic_ids, *ops->id);
1222 }
1223
1224 return error;
1225}
1226
1227static void unregister_pernet_operations(struct pernet_operations *ops)
1228{
1229 __unregister_pernet_operations(ops);
1230 rcu_barrier();
1231 if (ops->id)
1232 ida_free(&net_generic_ids, *ops->id);
1233}
1234
1235/**
1236 * register_pernet_subsys - register a network namespace subsystem
1237 * @ops: pernet operations structure for the subsystem
1238 *
1239 * Register a subsystem which has init and exit functions
1240 * that are called when network namespaces are created and
1241 * destroyed respectively.
1242 *
1243 * When registered all network namespace init functions are
1244 * called for every existing network namespace. Allowing kernel
1245 * modules to have a race free view of the set of network namespaces.
1246 *
1247 * When a new network namespace is created all of the init
1248 * methods are called in the order in which they were registered.
1249 *
1250 * When a network namespace is destroyed all of the exit methods
1251 * are called in the reverse of the order with which they were
1252 * registered.
1253 */
1254int register_pernet_subsys(struct pernet_operations *ops)
1255{
1256 int error;
1257 down_write(&pernet_ops_rwsem);
1258 error = register_pernet_operations(first_device, ops);
1259 up_write(&pernet_ops_rwsem);
1260 return error;
1261}
1262EXPORT_SYMBOL_GPL(register_pernet_subsys);
1263
1264/**
1265 * unregister_pernet_subsys - unregister a network namespace subsystem
1266 * @ops: pernet operations structure to manipulate
1267 *
1268 * Remove the pernet operations structure from the list to be
1269 * used when network namespaces are created or destroyed. In
1270 * addition run the exit method for all existing network
1271 * namespaces.
1272 */
1273void unregister_pernet_subsys(struct pernet_operations *ops)
1274{
1275 down_write(&pernet_ops_rwsem);
1276 unregister_pernet_operations(ops);
1277 up_write(&pernet_ops_rwsem);
1278}
1279EXPORT_SYMBOL_GPL(unregister_pernet_subsys);
1280
1281/**
1282 * register_pernet_device - register a network namespace device
1283 * @ops: pernet operations structure for the subsystem
1284 *
1285 * Register a device which has init and exit functions
1286 * that are called when network namespaces are created and
1287 * destroyed respectively.
1288 *
1289 * When registered all network namespace init functions are
1290 * called for every existing network namespace. Allowing kernel
1291 * modules to have a race free view of the set of network namespaces.
1292 *
1293 * When a new network namespace is created all of the init
1294 * methods are called in the order in which they were registered.
1295 *
1296 * When a network namespace is destroyed all of the exit methods
1297 * are called in the reverse of the order with which they were
1298 * registered.
1299 */
1300int register_pernet_device(struct pernet_operations *ops)
1301{
1302 int error;
1303 down_write(&pernet_ops_rwsem);
1304 error = register_pernet_operations(&pernet_list, ops);
1305 if (!error && (first_device == &pernet_list))
1306 first_device = &ops->list;
1307 up_write(&pernet_ops_rwsem);
1308 return error;
1309}
1310EXPORT_SYMBOL_GPL(register_pernet_device);
1311
1312/**
1313 * unregister_pernet_device - unregister a network namespace netdevice
1314 * @ops: pernet operations structure to manipulate
1315 *
1316 * Remove the pernet operations structure from the list to be
1317 * used when network namespaces are created or destroyed. In
1318 * addition run the exit method for all existing network
1319 * namespaces.
1320 */
1321void unregister_pernet_device(struct pernet_operations *ops)
1322{
1323 down_write(&pernet_ops_rwsem);
1324 if (&ops->list == first_device)
1325 first_device = first_device->next;
1326 unregister_pernet_operations(ops);
1327 up_write(&pernet_ops_rwsem);
1328}
1329EXPORT_SYMBOL_GPL(unregister_pernet_device);
1330
1331#ifdef CONFIG_NET_NS
1332static struct ns_common *netns_get(struct task_struct *task)
1333{
1334 struct net *net = NULL;
1335 struct nsproxy *nsproxy;
1336
1337 task_lock(task);
1338 nsproxy = task->nsproxy;
1339 if (nsproxy)
1340 net = get_net(nsproxy->net_ns);
1341 task_unlock(task);
1342
1343 return net ? &net->ns : NULL;
1344}
1345
1346static inline struct net *to_net_ns(struct ns_common *ns)
1347{
1348 return container_of(ns, struct net, ns);
1349}
1350
1351static void netns_put(struct ns_common *ns)
1352{
1353 put_net(to_net_ns(ns));
1354}
1355
1356static int netns_install(struct nsset *nsset, struct ns_common *ns)
1357{
1358 struct nsproxy *nsproxy = nsset->nsproxy;
1359 struct net *net = to_net_ns(ns);
1360
1361 if (!ns_capable(net->user_ns, CAP_SYS_ADMIN) ||
1362 !ns_capable(nsset->cred->user_ns, CAP_SYS_ADMIN))
1363 return -EPERM;
1364
1365 put_net(nsproxy->net_ns);
1366 nsproxy->net_ns = get_net(net);
1367 return 0;
1368}
1369
1370static struct user_namespace *netns_owner(struct ns_common *ns)
1371{
1372 return to_net_ns(ns)->user_ns;
1373}
1374
1375const struct proc_ns_operations netns_operations = {
1376 .name = "net",
1377 .type = CLONE_NEWNET,
1378 .get = netns_get,
1379 .put = netns_put,
1380 .install = netns_install,
1381 .owner = netns_owner,
1382};
1383#endif