Loading...
1#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
2
3#include <linux/workqueue.h>
4#include <linux/rtnetlink.h>
5#include <linux/cache.h>
6#include <linux/slab.h>
7#include <linux/list.h>
8#include <linux/delay.h>
9#include <linux/sched.h>
10#include <linux/idr.h>
11#include <linux/rculist.h>
12#include <linux/nsproxy.h>
13#include <linux/fs.h>
14#include <linux/proc_ns.h>
15#include <linux/file.h>
16#include <linux/export.h>
17#include <linux/user_namespace.h>
18#include <linux/net_namespace.h>
19#include <linux/sched/task.h>
20
21#include <net/sock.h>
22#include <net/netlink.h>
23#include <net/net_namespace.h>
24#include <net/netns/generic.h>
25
26/*
27 * Our network namespace constructor/destructor lists
28 */
29
30static LIST_HEAD(pernet_list);
31static struct list_head *first_device = &pernet_list;
32
33LIST_HEAD(net_namespace_list);
34EXPORT_SYMBOL_GPL(net_namespace_list);
35
36/* Protects net_namespace_list. Nests iside rtnl_lock() */
37DECLARE_RWSEM(net_rwsem);
38EXPORT_SYMBOL_GPL(net_rwsem);
39
40struct net init_net = {
41 .count = REFCOUNT_INIT(1),
42 .dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head),
43};
44EXPORT_SYMBOL(init_net);
45
46static bool init_net_initialized;
47/*
48 * pernet_ops_rwsem: protects: pernet_list, net_generic_ids,
49 * init_net_initialized and first_device pointer.
50 * This is internal net namespace object. Please, don't use it
51 * outside.
52 */
53DECLARE_RWSEM(pernet_ops_rwsem);
54EXPORT_SYMBOL_GPL(pernet_ops_rwsem);
55
56#define MIN_PERNET_OPS_ID \
57 ((sizeof(struct net_generic) + sizeof(void *) - 1) / sizeof(void *))
58
59#define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */
60
61static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS;
62
63static struct net_generic *net_alloc_generic(void)
64{
65 struct net_generic *ng;
66 unsigned int generic_size = offsetof(struct net_generic, ptr[max_gen_ptrs]);
67
68 ng = kzalloc(generic_size, GFP_KERNEL);
69 if (ng)
70 ng->s.len = max_gen_ptrs;
71
72 return ng;
73}
74
75static int net_assign_generic(struct net *net, unsigned int id, void *data)
76{
77 struct net_generic *ng, *old_ng;
78
79 BUG_ON(id < MIN_PERNET_OPS_ID);
80
81 old_ng = rcu_dereference_protected(net->gen,
82 lockdep_is_held(&pernet_ops_rwsem));
83 if (old_ng->s.len > id) {
84 old_ng->ptr[id] = data;
85 return 0;
86 }
87
88 ng = net_alloc_generic();
89 if (ng == NULL)
90 return -ENOMEM;
91
92 /*
93 * Some synchronisation notes:
94 *
95 * The net_generic explores the net->gen array inside rcu
96 * read section. Besides once set the net->gen->ptr[x]
97 * pointer never changes (see rules in netns/generic.h).
98 *
99 * That said, we simply duplicate this array and schedule
100 * the old copy for kfree after a grace period.
101 */
102
103 memcpy(&ng->ptr[MIN_PERNET_OPS_ID], &old_ng->ptr[MIN_PERNET_OPS_ID],
104 (old_ng->s.len - MIN_PERNET_OPS_ID) * sizeof(void *));
105 ng->ptr[id] = data;
106
107 rcu_assign_pointer(net->gen, ng);
108 kfree_rcu(old_ng, s.rcu);
109 return 0;
110}
111
112static int ops_init(const struct pernet_operations *ops, struct net *net)
113{
114 int err = -ENOMEM;
115 void *data = NULL;
116
117 if (ops->id && ops->size) {
118 data = kzalloc(ops->size, GFP_KERNEL);
119 if (!data)
120 goto out;
121
122 err = net_assign_generic(net, *ops->id, data);
123 if (err)
124 goto cleanup;
125 }
126 err = 0;
127 if (ops->init)
128 err = ops->init(net);
129 if (!err)
130 return 0;
131
132cleanup:
133 kfree(data);
134
135out:
136 return err;
137}
138
139static void ops_free(const struct pernet_operations *ops, struct net *net)
140{
141 if (ops->id && ops->size) {
142 kfree(net_generic(net, *ops->id));
143 }
144}
145
146static void ops_exit_list(const struct pernet_operations *ops,
147 struct list_head *net_exit_list)
148{
149 struct net *net;
150 if (ops->exit) {
151 list_for_each_entry(net, net_exit_list, exit_list)
152 ops->exit(net);
153 }
154 if (ops->exit_batch)
155 ops->exit_batch(net_exit_list);
156}
157
158static void ops_free_list(const struct pernet_operations *ops,
159 struct list_head *net_exit_list)
160{
161 struct net *net;
162 if (ops->size && ops->id) {
163 list_for_each_entry(net, net_exit_list, exit_list)
164 ops_free(ops, net);
165 }
166}
167
168/* should be called with nsid_lock held */
169static int alloc_netid(struct net *net, struct net *peer, int reqid)
170{
171 int min = 0, max = 0;
172
173 if (reqid >= 0) {
174 min = reqid;
175 max = reqid + 1;
176 }
177
178 return idr_alloc(&net->netns_ids, peer, min, max, GFP_ATOMIC);
179}
180
181/* This function is used by idr_for_each(). If net is equal to peer, the
182 * function returns the id so that idr_for_each() stops. Because we cannot
183 * returns the id 0 (idr_for_each() will not stop), we return the magic value
184 * NET_ID_ZERO (-1) for it.
185 */
186#define NET_ID_ZERO -1
187static int net_eq_idr(int id, void *net, void *peer)
188{
189 if (net_eq(net, peer))
190 return id ? : NET_ID_ZERO;
191 return 0;
192}
193
194/* Should be called with nsid_lock held. If a new id is assigned, the bool alloc
195 * is set to true, thus the caller knows that the new id must be notified via
196 * rtnl.
197 */
198static int __peernet2id_alloc(struct net *net, struct net *peer, bool *alloc)
199{
200 int id = idr_for_each(&net->netns_ids, net_eq_idr, peer);
201 bool alloc_it = *alloc;
202
203 *alloc = false;
204
205 /* Magic value for id 0. */
206 if (id == NET_ID_ZERO)
207 return 0;
208 if (id > 0)
209 return id;
210
211 if (alloc_it) {
212 id = alloc_netid(net, peer, -1);
213 *alloc = true;
214 return id >= 0 ? id : NETNSA_NSID_NOT_ASSIGNED;
215 }
216
217 return NETNSA_NSID_NOT_ASSIGNED;
218}
219
220/* should be called with nsid_lock held */
221static int __peernet2id(struct net *net, struct net *peer)
222{
223 bool no = false;
224
225 return __peernet2id_alloc(net, peer, &no);
226}
227
228static void rtnl_net_notifyid(struct net *net, int cmd, int id);
229/* This function returns the id of a peer netns. If no id is assigned, one will
230 * be allocated and returned.
231 */
232int peernet2id_alloc(struct net *net, struct net *peer)
233{
234 bool alloc = false, alive = false;
235 int id;
236
237 if (refcount_read(&net->count) == 0)
238 return NETNSA_NSID_NOT_ASSIGNED;
239 spin_lock_bh(&net->nsid_lock);
240 /*
241 * When peer is obtained from RCU lists, we may race with
242 * its cleanup. Check whether it's alive, and this guarantees
243 * we never hash a peer back to net->netns_ids, after it has
244 * just been idr_remove()'d from there in cleanup_net().
245 */
246 if (maybe_get_net(peer))
247 alive = alloc = true;
248 id = __peernet2id_alloc(net, peer, &alloc);
249 spin_unlock_bh(&net->nsid_lock);
250 if (alloc && id >= 0)
251 rtnl_net_notifyid(net, RTM_NEWNSID, id);
252 if (alive)
253 put_net(peer);
254 return id;
255}
256EXPORT_SYMBOL_GPL(peernet2id_alloc);
257
258/* This function returns, if assigned, the id of a peer netns. */
259int peernet2id(struct net *net, struct net *peer)
260{
261 int id;
262
263 spin_lock_bh(&net->nsid_lock);
264 id = __peernet2id(net, peer);
265 spin_unlock_bh(&net->nsid_lock);
266 return id;
267}
268EXPORT_SYMBOL(peernet2id);
269
270/* This function returns true is the peer netns has an id assigned into the
271 * current netns.
272 */
273bool peernet_has_id(struct net *net, struct net *peer)
274{
275 return peernet2id(net, peer) >= 0;
276}
277
278struct net *get_net_ns_by_id(struct net *net, int id)
279{
280 struct net *peer;
281
282 if (id < 0)
283 return NULL;
284
285 rcu_read_lock();
286 peer = idr_find(&net->netns_ids, id);
287 if (peer)
288 peer = maybe_get_net(peer);
289 rcu_read_unlock();
290
291 return peer;
292}
293
294/*
295 * setup_net runs the initializers for the network namespace object.
296 */
297static __net_init int setup_net(struct net *net, struct user_namespace *user_ns)
298{
299 /* Must be called with pernet_ops_rwsem held */
300 const struct pernet_operations *ops, *saved_ops;
301 int error = 0;
302 LIST_HEAD(net_exit_list);
303
304 refcount_set(&net->count, 1);
305 refcount_set(&net->passive, 1);
306 net->dev_base_seq = 1;
307 net->user_ns = user_ns;
308 idr_init(&net->netns_ids);
309 spin_lock_init(&net->nsid_lock);
310 mutex_init(&net->ipv4.ra_mutex);
311
312 list_for_each_entry(ops, &pernet_list, list) {
313 error = ops_init(ops, net);
314 if (error < 0)
315 goto out_undo;
316 }
317 down_write(&net_rwsem);
318 list_add_tail_rcu(&net->list, &net_namespace_list);
319 up_write(&net_rwsem);
320out:
321 return error;
322
323out_undo:
324 /* Walk through the list backwards calling the exit functions
325 * for the pernet modules whose init functions did not fail.
326 */
327 list_add(&net->exit_list, &net_exit_list);
328 saved_ops = ops;
329 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
330 ops_exit_list(ops, &net_exit_list);
331
332 ops = saved_ops;
333 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
334 ops_free_list(ops, &net_exit_list);
335
336 rcu_barrier();
337 goto out;
338}
339
340static int __net_init net_defaults_init_net(struct net *net)
341{
342 net->core.sysctl_somaxconn = SOMAXCONN;
343 return 0;
344}
345
346static struct pernet_operations net_defaults_ops = {
347 .init = net_defaults_init_net,
348};
349
350static __init int net_defaults_init(void)
351{
352 if (register_pernet_subsys(&net_defaults_ops))
353 panic("Cannot initialize net default settings");
354
355 return 0;
356}
357
358core_initcall(net_defaults_init);
359
360#ifdef CONFIG_NET_NS
361static struct ucounts *inc_net_namespaces(struct user_namespace *ns)
362{
363 return inc_ucount(ns, current_euid(), UCOUNT_NET_NAMESPACES);
364}
365
366static void dec_net_namespaces(struct ucounts *ucounts)
367{
368 dec_ucount(ucounts, UCOUNT_NET_NAMESPACES);
369}
370
371static struct kmem_cache *net_cachep __ro_after_init;
372static struct workqueue_struct *netns_wq;
373
374static struct net *net_alloc(void)
375{
376 struct net *net = NULL;
377 struct net_generic *ng;
378
379 ng = net_alloc_generic();
380 if (!ng)
381 goto out;
382
383 net = kmem_cache_zalloc(net_cachep, GFP_KERNEL);
384 if (!net)
385 goto out_free;
386
387 rcu_assign_pointer(net->gen, ng);
388out:
389 return net;
390
391out_free:
392 kfree(ng);
393 goto out;
394}
395
396static void net_free(struct net *net)
397{
398 kfree(rcu_access_pointer(net->gen));
399 kmem_cache_free(net_cachep, net);
400}
401
402void net_drop_ns(void *p)
403{
404 struct net *ns = p;
405 if (ns && refcount_dec_and_test(&ns->passive))
406 net_free(ns);
407}
408
409struct net *copy_net_ns(unsigned long flags,
410 struct user_namespace *user_ns, struct net *old_net)
411{
412 struct ucounts *ucounts;
413 struct net *net;
414 int rv;
415
416 if (!(flags & CLONE_NEWNET))
417 return get_net(old_net);
418
419 ucounts = inc_net_namespaces(user_ns);
420 if (!ucounts)
421 return ERR_PTR(-ENOSPC);
422
423 net = net_alloc();
424 if (!net) {
425 rv = -ENOMEM;
426 goto dec_ucounts;
427 }
428 refcount_set(&net->passive, 1);
429 net->ucounts = ucounts;
430 get_user_ns(user_ns);
431
432 rv = down_read_killable(&pernet_ops_rwsem);
433 if (rv < 0)
434 goto put_userns;
435
436 rv = setup_net(net, user_ns);
437
438 up_read(&pernet_ops_rwsem);
439
440 if (rv < 0) {
441put_userns:
442 put_user_ns(user_ns);
443 net_drop_ns(net);
444dec_ucounts:
445 dec_net_namespaces(ucounts);
446 return ERR_PTR(rv);
447 }
448 return net;
449}
450
451static void unhash_nsid(struct net *net, struct net *last)
452{
453 struct net *tmp;
454 /* This function is only called from cleanup_net() work,
455 * and this work is the only process, that may delete
456 * a net from net_namespace_list. So, when the below
457 * is executing, the list may only grow. Thus, we do not
458 * use for_each_net_rcu() or net_rwsem.
459 */
460 for_each_net(tmp) {
461 int id;
462
463 spin_lock_bh(&tmp->nsid_lock);
464 id = __peernet2id(tmp, net);
465 if (id >= 0)
466 idr_remove(&tmp->netns_ids, id);
467 spin_unlock_bh(&tmp->nsid_lock);
468 if (id >= 0)
469 rtnl_net_notifyid(tmp, RTM_DELNSID, id);
470 if (tmp == last)
471 break;
472 }
473 spin_lock_bh(&net->nsid_lock);
474 idr_destroy(&net->netns_ids);
475 spin_unlock_bh(&net->nsid_lock);
476}
477
478static LLIST_HEAD(cleanup_list);
479
480static void cleanup_net(struct work_struct *work)
481{
482 const struct pernet_operations *ops;
483 struct net *net, *tmp, *last;
484 struct llist_node *net_kill_list;
485 LIST_HEAD(net_exit_list);
486
487 /* Atomically snapshot the list of namespaces to cleanup */
488 net_kill_list = llist_del_all(&cleanup_list);
489
490 down_read(&pernet_ops_rwsem);
491
492 /* Don't let anyone else find us. */
493 down_write(&net_rwsem);
494 llist_for_each_entry(net, net_kill_list, cleanup_list)
495 list_del_rcu(&net->list);
496 /* Cache last net. After we unlock rtnl, no one new net
497 * added to net_namespace_list can assign nsid pointer
498 * to a net from net_kill_list (see peernet2id_alloc()).
499 * So, we skip them in unhash_nsid().
500 *
501 * Note, that unhash_nsid() does not delete nsid links
502 * between net_kill_list's nets, as they've already
503 * deleted from net_namespace_list. But, this would be
504 * useless anyway, as netns_ids are destroyed there.
505 */
506 last = list_last_entry(&net_namespace_list, struct net, list);
507 up_write(&net_rwsem);
508
509 llist_for_each_entry(net, net_kill_list, cleanup_list) {
510 unhash_nsid(net, last);
511 list_add_tail(&net->exit_list, &net_exit_list);
512 }
513
514 /*
515 * Another CPU might be rcu-iterating the list, wait for it.
516 * This needs to be before calling the exit() notifiers, so
517 * the rcu_barrier() below isn't sufficient alone.
518 */
519 synchronize_rcu();
520
521 /* Run all of the network namespace exit methods */
522 list_for_each_entry_reverse(ops, &pernet_list, list)
523 ops_exit_list(ops, &net_exit_list);
524
525 /* Free the net generic variables */
526 list_for_each_entry_reverse(ops, &pernet_list, list)
527 ops_free_list(ops, &net_exit_list);
528
529 up_read(&pernet_ops_rwsem);
530
531 /* Ensure there are no outstanding rcu callbacks using this
532 * network namespace.
533 */
534 rcu_barrier();
535
536 /* Finally it is safe to free my network namespace structure */
537 list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
538 list_del_init(&net->exit_list);
539 dec_net_namespaces(net->ucounts);
540 put_user_ns(net->user_ns);
541 net_drop_ns(net);
542 }
543}
544
545/**
546 * net_ns_barrier - wait until concurrent net_cleanup_work is done
547 *
548 * cleanup_net runs from work queue and will first remove namespaces
549 * from the global list, then run net exit functions.
550 *
551 * Call this in module exit path to make sure that all netns
552 * ->exit ops have been invoked before the function is removed.
553 */
554void net_ns_barrier(void)
555{
556 down_write(&pernet_ops_rwsem);
557 up_write(&pernet_ops_rwsem);
558}
559EXPORT_SYMBOL(net_ns_barrier);
560
561static DECLARE_WORK(net_cleanup_work, cleanup_net);
562
563void __put_net(struct net *net)
564{
565 /* Cleanup the network namespace in process context */
566 if (llist_add(&net->cleanup_list, &cleanup_list))
567 queue_work(netns_wq, &net_cleanup_work);
568}
569EXPORT_SYMBOL_GPL(__put_net);
570
571struct net *get_net_ns_by_fd(int fd)
572{
573 struct file *file;
574 struct ns_common *ns;
575 struct net *net;
576
577 file = proc_ns_fget(fd);
578 if (IS_ERR(file))
579 return ERR_CAST(file);
580
581 ns = get_proc_ns(file_inode(file));
582 if (ns->ops == &netns_operations)
583 net = get_net(container_of(ns, struct net, ns));
584 else
585 net = ERR_PTR(-EINVAL);
586
587 fput(file);
588 return net;
589}
590
591#else
592struct net *get_net_ns_by_fd(int fd)
593{
594 return ERR_PTR(-EINVAL);
595}
596#endif
597EXPORT_SYMBOL_GPL(get_net_ns_by_fd);
598
599struct net *get_net_ns_by_pid(pid_t pid)
600{
601 struct task_struct *tsk;
602 struct net *net;
603
604 /* Lookup the network namespace */
605 net = ERR_PTR(-ESRCH);
606 rcu_read_lock();
607 tsk = find_task_by_vpid(pid);
608 if (tsk) {
609 struct nsproxy *nsproxy;
610 task_lock(tsk);
611 nsproxy = tsk->nsproxy;
612 if (nsproxy)
613 net = get_net(nsproxy->net_ns);
614 task_unlock(tsk);
615 }
616 rcu_read_unlock();
617 return net;
618}
619EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
620
621static __net_init int net_ns_net_init(struct net *net)
622{
623#ifdef CONFIG_NET_NS
624 net->ns.ops = &netns_operations;
625#endif
626 return ns_alloc_inum(&net->ns);
627}
628
629static __net_exit void net_ns_net_exit(struct net *net)
630{
631 ns_free_inum(&net->ns);
632}
633
634static struct pernet_operations __net_initdata net_ns_ops = {
635 .init = net_ns_net_init,
636 .exit = net_ns_net_exit,
637};
638
639static const struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = {
640 [NETNSA_NONE] = { .type = NLA_UNSPEC },
641 [NETNSA_NSID] = { .type = NLA_S32 },
642 [NETNSA_PID] = { .type = NLA_U32 },
643 [NETNSA_FD] = { .type = NLA_U32 },
644};
645
646static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh,
647 struct netlink_ext_ack *extack)
648{
649 struct net *net = sock_net(skb->sk);
650 struct nlattr *tb[NETNSA_MAX + 1];
651 struct nlattr *nla;
652 struct net *peer;
653 int nsid, err;
654
655 err = nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX,
656 rtnl_net_policy, extack);
657 if (err < 0)
658 return err;
659 if (!tb[NETNSA_NSID]) {
660 NL_SET_ERR_MSG(extack, "nsid is missing");
661 return -EINVAL;
662 }
663 nsid = nla_get_s32(tb[NETNSA_NSID]);
664
665 if (tb[NETNSA_PID]) {
666 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
667 nla = tb[NETNSA_PID];
668 } else if (tb[NETNSA_FD]) {
669 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
670 nla = tb[NETNSA_FD];
671 } else {
672 NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
673 return -EINVAL;
674 }
675 if (IS_ERR(peer)) {
676 NL_SET_BAD_ATTR(extack, nla);
677 NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
678 return PTR_ERR(peer);
679 }
680
681 spin_lock_bh(&net->nsid_lock);
682 if (__peernet2id(net, peer) >= 0) {
683 spin_unlock_bh(&net->nsid_lock);
684 err = -EEXIST;
685 NL_SET_BAD_ATTR(extack, nla);
686 NL_SET_ERR_MSG(extack,
687 "Peer netns already has a nsid assigned");
688 goto out;
689 }
690
691 err = alloc_netid(net, peer, nsid);
692 spin_unlock_bh(&net->nsid_lock);
693 if (err >= 0) {
694 rtnl_net_notifyid(net, RTM_NEWNSID, err);
695 err = 0;
696 } else if (err == -ENOSPC && nsid >= 0) {
697 err = -EEXIST;
698 NL_SET_BAD_ATTR(extack, tb[NETNSA_NSID]);
699 NL_SET_ERR_MSG(extack, "The specified nsid is already used");
700 }
701out:
702 put_net(peer);
703 return err;
704}
705
706static int rtnl_net_get_size(void)
707{
708 return NLMSG_ALIGN(sizeof(struct rtgenmsg))
709 + nla_total_size(sizeof(s32)) /* NETNSA_NSID */
710 ;
711}
712
713static int rtnl_net_fill(struct sk_buff *skb, u32 portid, u32 seq, int flags,
714 int cmd, struct net *net, int nsid)
715{
716 struct nlmsghdr *nlh;
717 struct rtgenmsg *rth;
718
719 nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rth), flags);
720 if (!nlh)
721 return -EMSGSIZE;
722
723 rth = nlmsg_data(nlh);
724 rth->rtgen_family = AF_UNSPEC;
725
726 if (nla_put_s32(skb, NETNSA_NSID, nsid))
727 goto nla_put_failure;
728
729 nlmsg_end(skb, nlh);
730 return 0;
731
732nla_put_failure:
733 nlmsg_cancel(skb, nlh);
734 return -EMSGSIZE;
735}
736
737static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh,
738 struct netlink_ext_ack *extack)
739{
740 struct net *net = sock_net(skb->sk);
741 struct nlattr *tb[NETNSA_MAX + 1];
742 struct nlattr *nla;
743 struct sk_buff *msg;
744 struct net *peer;
745 int err, id;
746
747 err = nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX,
748 rtnl_net_policy, extack);
749 if (err < 0)
750 return err;
751 if (tb[NETNSA_PID]) {
752 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
753 nla = tb[NETNSA_PID];
754 } else if (tb[NETNSA_FD]) {
755 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
756 nla = tb[NETNSA_FD];
757 } else {
758 NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
759 return -EINVAL;
760 }
761
762 if (IS_ERR(peer)) {
763 NL_SET_BAD_ATTR(extack, nla);
764 NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
765 return PTR_ERR(peer);
766 }
767
768 msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
769 if (!msg) {
770 err = -ENOMEM;
771 goto out;
772 }
773
774 id = peernet2id(net, peer);
775 err = rtnl_net_fill(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq, 0,
776 RTM_NEWNSID, net, id);
777 if (err < 0)
778 goto err_out;
779
780 err = rtnl_unicast(msg, net, NETLINK_CB(skb).portid);
781 goto out;
782
783err_out:
784 nlmsg_free(msg);
785out:
786 put_net(peer);
787 return err;
788}
789
790struct rtnl_net_dump_cb {
791 struct net *net;
792 struct sk_buff *skb;
793 struct netlink_callback *cb;
794 int idx;
795 int s_idx;
796};
797
798static int rtnl_net_dumpid_one(int id, void *peer, void *data)
799{
800 struct rtnl_net_dump_cb *net_cb = (struct rtnl_net_dump_cb *)data;
801 int ret;
802
803 if (net_cb->idx < net_cb->s_idx)
804 goto cont;
805
806 ret = rtnl_net_fill(net_cb->skb, NETLINK_CB(net_cb->cb->skb).portid,
807 net_cb->cb->nlh->nlmsg_seq, NLM_F_MULTI,
808 RTM_NEWNSID, net_cb->net, id);
809 if (ret < 0)
810 return ret;
811
812cont:
813 net_cb->idx++;
814 return 0;
815}
816
817static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb)
818{
819 struct net *net = sock_net(skb->sk);
820 struct rtnl_net_dump_cb net_cb = {
821 .net = net,
822 .skb = skb,
823 .cb = cb,
824 .idx = 0,
825 .s_idx = cb->args[0],
826 };
827
828 spin_lock_bh(&net->nsid_lock);
829 idr_for_each(&net->netns_ids, rtnl_net_dumpid_one, &net_cb);
830 spin_unlock_bh(&net->nsid_lock);
831
832 cb->args[0] = net_cb.idx;
833 return skb->len;
834}
835
836static void rtnl_net_notifyid(struct net *net, int cmd, int id)
837{
838 struct sk_buff *msg;
839 int err = -ENOMEM;
840
841 msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
842 if (!msg)
843 goto out;
844
845 err = rtnl_net_fill(msg, 0, 0, 0, cmd, net, id);
846 if (err < 0)
847 goto err_out;
848
849 rtnl_notify(msg, net, 0, RTNLGRP_NSID, NULL, 0);
850 return;
851
852err_out:
853 nlmsg_free(msg);
854out:
855 rtnl_set_sk_err(net, RTNLGRP_NSID, err);
856}
857
858static int __init net_ns_init(void)
859{
860 struct net_generic *ng;
861
862#ifdef CONFIG_NET_NS
863 net_cachep = kmem_cache_create("net_namespace", sizeof(struct net),
864 SMP_CACHE_BYTES,
865 SLAB_PANIC|SLAB_ACCOUNT, NULL);
866
867 /* Create workqueue for cleanup */
868 netns_wq = create_singlethread_workqueue("netns");
869 if (!netns_wq)
870 panic("Could not create netns workq");
871#endif
872
873 ng = net_alloc_generic();
874 if (!ng)
875 panic("Could not allocate generic netns");
876
877 rcu_assign_pointer(init_net.gen, ng);
878
879 down_write(&pernet_ops_rwsem);
880 if (setup_net(&init_net, &init_user_ns))
881 panic("Could not setup the initial network namespace");
882
883 init_net_initialized = true;
884 up_write(&pernet_ops_rwsem);
885
886 register_pernet_subsys(&net_ns_ops);
887
888 rtnl_register(PF_UNSPEC, RTM_NEWNSID, rtnl_net_newid, NULL,
889 RTNL_FLAG_DOIT_UNLOCKED);
890 rtnl_register(PF_UNSPEC, RTM_GETNSID, rtnl_net_getid, rtnl_net_dumpid,
891 RTNL_FLAG_DOIT_UNLOCKED);
892
893 return 0;
894}
895
896pure_initcall(net_ns_init);
897
898#ifdef CONFIG_NET_NS
899static int __register_pernet_operations(struct list_head *list,
900 struct pernet_operations *ops)
901{
902 struct net *net;
903 int error;
904 LIST_HEAD(net_exit_list);
905
906 list_add_tail(&ops->list, list);
907 if (ops->init || (ops->id && ops->size)) {
908 /* We held write locked pernet_ops_rwsem, and parallel
909 * setup_net() and cleanup_net() are not possible.
910 */
911 for_each_net(net) {
912 error = ops_init(ops, net);
913 if (error)
914 goto out_undo;
915 list_add_tail(&net->exit_list, &net_exit_list);
916 }
917 }
918 return 0;
919
920out_undo:
921 /* If I have an error cleanup all namespaces I initialized */
922 list_del(&ops->list);
923 ops_exit_list(ops, &net_exit_list);
924 ops_free_list(ops, &net_exit_list);
925 return error;
926}
927
928static void __unregister_pernet_operations(struct pernet_operations *ops)
929{
930 struct net *net;
931 LIST_HEAD(net_exit_list);
932
933 list_del(&ops->list);
934 /* See comment in __register_pernet_operations() */
935 for_each_net(net)
936 list_add_tail(&net->exit_list, &net_exit_list);
937 ops_exit_list(ops, &net_exit_list);
938 ops_free_list(ops, &net_exit_list);
939}
940
941#else
942
943static int __register_pernet_operations(struct list_head *list,
944 struct pernet_operations *ops)
945{
946 if (!init_net_initialized) {
947 list_add_tail(&ops->list, list);
948 return 0;
949 }
950
951 return ops_init(ops, &init_net);
952}
953
954static void __unregister_pernet_operations(struct pernet_operations *ops)
955{
956 if (!init_net_initialized) {
957 list_del(&ops->list);
958 } else {
959 LIST_HEAD(net_exit_list);
960 list_add(&init_net.exit_list, &net_exit_list);
961 ops_exit_list(ops, &net_exit_list);
962 ops_free_list(ops, &net_exit_list);
963 }
964}
965
966#endif /* CONFIG_NET_NS */
967
968static DEFINE_IDA(net_generic_ids);
969
970static int register_pernet_operations(struct list_head *list,
971 struct pernet_operations *ops)
972{
973 int error;
974
975 if (ops->id) {
976again:
977 error = ida_get_new_above(&net_generic_ids, MIN_PERNET_OPS_ID, ops->id);
978 if (error < 0) {
979 if (error == -EAGAIN) {
980 ida_pre_get(&net_generic_ids, GFP_KERNEL);
981 goto again;
982 }
983 return error;
984 }
985 max_gen_ptrs = max(max_gen_ptrs, *ops->id + 1);
986 }
987 error = __register_pernet_operations(list, ops);
988 if (error) {
989 rcu_barrier();
990 if (ops->id)
991 ida_remove(&net_generic_ids, *ops->id);
992 }
993
994 return error;
995}
996
997static void unregister_pernet_operations(struct pernet_operations *ops)
998{
999 __unregister_pernet_operations(ops);
1000 rcu_barrier();
1001 if (ops->id)
1002 ida_remove(&net_generic_ids, *ops->id);
1003}
1004
1005/**
1006 * register_pernet_subsys - register a network namespace subsystem
1007 * @ops: pernet operations structure for the subsystem
1008 *
1009 * Register a subsystem which has init and exit functions
1010 * that are called when network namespaces are created and
1011 * destroyed respectively.
1012 *
1013 * When registered all network namespace init functions are
1014 * called for every existing network namespace. Allowing kernel
1015 * modules to have a race free view of the set of network namespaces.
1016 *
1017 * When a new network namespace is created all of the init
1018 * methods are called in the order in which they were registered.
1019 *
1020 * When a network namespace is destroyed all of the exit methods
1021 * are called in the reverse of the order with which they were
1022 * registered.
1023 */
1024int register_pernet_subsys(struct pernet_operations *ops)
1025{
1026 int error;
1027 down_write(&pernet_ops_rwsem);
1028 error = register_pernet_operations(first_device, ops);
1029 up_write(&pernet_ops_rwsem);
1030 return error;
1031}
1032EXPORT_SYMBOL_GPL(register_pernet_subsys);
1033
1034/**
1035 * unregister_pernet_subsys - unregister a network namespace subsystem
1036 * @ops: pernet operations structure to manipulate
1037 *
1038 * Remove the pernet operations structure from the list to be
1039 * used when network namespaces are created or destroyed. In
1040 * addition run the exit method for all existing network
1041 * namespaces.
1042 */
1043void unregister_pernet_subsys(struct pernet_operations *ops)
1044{
1045 down_write(&pernet_ops_rwsem);
1046 unregister_pernet_operations(ops);
1047 up_write(&pernet_ops_rwsem);
1048}
1049EXPORT_SYMBOL_GPL(unregister_pernet_subsys);
1050
1051/**
1052 * register_pernet_device - register a network namespace device
1053 * @ops: pernet operations structure for the subsystem
1054 *
1055 * Register a device which has init and exit functions
1056 * that are called when network namespaces are created and
1057 * destroyed respectively.
1058 *
1059 * When registered all network namespace init functions are
1060 * called for every existing network namespace. Allowing kernel
1061 * modules to have a race free view of the set of network namespaces.
1062 *
1063 * When a new network namespace is created all of the init
1064 * methods are called in the order in which they were registered.
1065 *
1066 * When a network namespace is destroyed all of the exit methods
1067 * are called in the reverse of the order with which they were
1068 * registered.
1069 */
1070int register_pernet_device(struct pernet_operations *ops)
1071{
1072 int error;
1073 down_write(&pernet_ops_rwsem);
1074 error = register_pernet_operations(&pernet_list, ops);
1075 if (!error && (first_device == &pernet_list))
1076 first_device = &ops->list;
1077 up_write(&pernet_ops_rwsem);
1078 return error;
1079}
1080EXPORT_SYMBOL_GPL(register_pernet_device);
1081
1082/**
1083 * unregister_pernet_device - unregister a network namespace netdevice
1084 * @ops: pernet operations structure to manipulate
1085 *
1086 * Remove the pernet operations structure from the list to be
1087 * used when network namespaces are created or destroyed. In
1088 * addition run the exit method for all existing network
1089 * namespaces.
1090 */
1091void unregister_pernet_device(struct pernet_operations *ops)
1092{
1093 down_write(&pernet_ops_rwsem);
1094 if (&ops->list == first_device)
1095 first_device = first_device->next;
1096 unregister_pernet_operations(ops);
1097 up_write(&pernet_ops_rwsem);
1098}
1099EXPORT_SYMBOL_GPL(unregister_pernet_device);
1100
1101#ifdef CONFIG_NET_NS
1102static struct ns_common *netns_get(struct task_struct *task)
1103{
1104 struct net *net = NULL;
1105 struct nsproxy *nsproxy;
1106
1107 task_lock(task);
1108 nsproxy = task->nsproxy;
1109 if (nsproxy)
1110 net = get_net(nsproxy->net_ns);
1111 task_unlock(task);
1112
1113 return net ? &net->ns : NULL;
1114}
1115
1116static inline struct net *to_net_ns(struct ns_common *ns)
1117{
1118 return container_of(ns, struct net, ns);
1119}
1120
1121static void netns_put(struct ns_common *ns)
1122{
1123 put_net(to_net_ns(ns));
1124}
1125
1126static int netns_install(struct nsproxy *nsproxy, struct ns_common *ns)
1127{
1128 struct net *net = to_net_ns(ns);
1129
1130 if (!ns_capable(net->user_ns, CAP_SYS_ADMIN) ||
1131 !ns_capable(current_user_ns(), CAP_SYS_ADMIN))
1132 return -EPERM;
1133
1134 put_net(nsproxy->net_ns);
1135 nsproxy->net_ns = get_net(net);
1136 return 0;
1137}
1138
1139static struct user_namespace *netns_owner(struct ns_common *ns)
1140{
1141 return to_net_ns(ns)->user_ns;
1142}
1143
1144const struct proc_ns_operations netns_operations = {
1145 .name = "net",
1146 .type = CLONE_NEWNET,
1147 .get = netns_get,
1148 .put = netns_put,
1149 .install = netns_install,
1150 .owner = netns_owner,
1151};
1152#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#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
33static LIST_HEAD(pernet_list);
34static struct list_head *first_device = &pernet_list;
35
36LIST_HEAD(net_namespace_list);
37EXPORT_SYMBOL_GPL(net_namespace_list);
38
39/* Protects net_namespace_list. Nests iside rtnl_lock() */
40DECLARE_RWSEM(net_rwsem);
41EXPORT_SYMBOL_GPL(net_rwsem);
42
43#ifdef CONFIG_KEYS
44static struct key_tag init_net_key_domain = { .usage = REFCOUNT_INIT(1) };
45#endif
46
47struct net init_net = {
48 .ns.count = REFCOUNT_INIT(1),
49 .dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head),
50#ifdef CONFIG_KEYS
51 .key_domain = &init_net_key_domain,
52#endif
53};
54EXPORT_SYMBOL(init_net);
55
56static bool init_net_initialized;
57/*
58 * pernet_ops_rwsem: protects: pernet_list, net_generic_ids,
59 * init_net_initialized and first_device pointer.
60 * This is internal net namespace object. Please, don't use it
61 * outside.
62 */
63DECLARE_RWSEM(pernet_ops_rwsem);
64EXPORT_SYMBOL_GPL(pernet_ops_rwsem);
65
66#define MIN_PERNET_OPS_ID \
67 ((sizeof(struct net_generic) + sizeof(void *) - 1) / sizeof(void *))
68
69#define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */
70
71static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS;
72
73DEFINE_COOKIE(net_cookie);
74
75static struct net_generic *net_alloc_generic(void)
76{
77 struct net_generic *ng;
78 unsigned int generic_size = offsetof(struct net_generic, ptr[max_gen_ptrs]);
79
80 ng = kzalloc(generic_size, GFP_KERNEL);
81 if (ng)
82 ng->s.len = max_gen_ptrs;
83
84 return ng;
85}
86
87static int net_assign_generic(struct net *net, unsigned int id, void *data)
88{
89 struct net_generic *ng, *old_ng;
90
91 BUG_ON(id < MIN_PERNET_OPS_ID);
92
93 old_ng = rcu_dereference_protected(net->gen,
94 lockdep_is_held(&pernet_ops_rwsem));
95 if (old_ng->s.len > id) {
96 old_ng->ptr[id] = data;
97 return 0;
98 }
99
100 ng = net_alloc_generic();
101 if (ng == NULL)
102 return -ENOMEM;
103
104 /*
105 * Some synchronisation notes:
106 *
107 * The net_generic explores the net->gen array inside rcu
108 * read section. Besides once set the net->gen->ptr[x]
109 * pointer never changes (see rules in netns/generic.h).
110 *
111 * That said, we simply duplicate this array and schedule
112 * the old copy for kfree after a grace period.
113 */
114
115 memcpy(&ng->ptr[MIN_PERNET_OPS_ID], &old_ng->ptr[MIN_PERNET_OPS_ID],
116 (old_ng->s.len - MIN_PERNET_OPS_ID) * sizeof(void *));
117 ng->ptr[id] = data;
118
119 rcu_assign_pointer(net->gen, ng);
120 kfree_rcu(old_ng, s.rcu);
121 return 0;
122}
123
124static int ops_init(const struct pernet_operations *ops, struct net *net)
125{
126 int err = -ENOMEM;
127 void *data = NULL;
128
129 if (ops->id && ops->size) {
130 data = kzalloc(ops->size, GFP_KERNEL);
131 if (!data)
132 goto out;
133
134 err = net_assign_generic(net, *ops->id, data);
135 if (err)
136 goto cleanup;
137 }
138 err = 0;
139 if (ops->init)
140 err = ops->init(net);
141 if (!err)
142 return 0;
143
144cleanup:
145 kfree(data);
146
147out:
148 return err;
149}
150
151static void ops_free(const struct pernet_operations *ops, struct net *net)
152{
153 if (ops->id && ops->size) {
154 kfree(net_generic(net, *ops->id));
155 }
156}
157
158static void ops_pre_exit_list(const struct pernet_operations *ops,
159 struct list_head *net_exit_list)
160{
161 struct net *net;
162
163 if (ops->pre_exit) {
164 list_for_each_entry(net, net_exit_list, exit_list)
165 ops->pre_exit(net);
166 }
167}
168
169static void ops_exit_list(const struct pernet_operations *ops,
170 struct list_head *net_exit_list)
171{
172 struct net *net;
173 if (ops->exit) {
174 list_for_each_entry(net, net_exit_list, exit_list)
175 ops->exit(net);
176 }
177 if (ops->exit_batch)
178 ops->exit_batch(net_exit_list);
179}
180
181static void ops_free_list(const struct pernet_operations *ops,
182 struct list_head *net_exit_list)
183{
184 struct net *net;
185 if (ops->size && ops->id) {
186 list_for_each_entry(net, net_exit_list, exit_list)
187 ops_free(ops, net);
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}
309
310/*
311 * setup_net runs the initializers for the network namespace object.
312 */
313static __net_init int setup_net(struct net *net, struct user_namespace *user_ns)
314{
315 /* Must be called with pernet_ops_rwsem held */
316 const struct pernet_operations *ops, *saved_ops;
317 int error = 0;
318 LIST_HEAD(net_exit_list);
319
320 refcount_set(&net->ns.count, 1);
321 refcount_set(&net->passive, 1);
322 get_random_bytes(&net->hash_mix, sizeof(u32));
323 preempt_disable();
324 net->net_cookie = gen_cookie_next(&net_cookie);
325 preempt_enable();
326 net->dev_base_seq = 1;
327 net->user_ns = user_ns;
328 idr_init(&net->netns_ids);
329 spin_lock_init(&net->nsid_lock);
330 mutex_init(&net->ipv4.ra_mutex);
331
332 list_for_each_entry(ops, &pernet_list, list) {
333 error = ops_init(ops, net);
334 if (error < 0)
335 goto out_undo;
336 }
337 down_write(&net_rwsem);
338 list_add_tail_rcu(&net->list, &net_namespace_list);
339 up_write(&net_rwsem);
340out:
341 return error;
342
343out_undo:
344 /* Walk through the list backwards calling the exit functions
345 * for the pernet modules whose init functions did not fail.
346 */
347 list_add(&net->exit_list, &net_exit_list);
348 saved_ops = ops;
349 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
350 ops_pre_exit_list(ops, &net_exit_list);
351
352 synchronize_rcu();
353
354 ops = saved_ops;
355 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
356 ops_exit_list(ops, &net_exit_list);
357
358 ops = saved_ops;
359 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
360 ops_free_list(ops, &net_exit_list);
361
362 rcu_barrier();
363 goto out;
364}
365
366static int __net_init net_defaults_init_net(struct net *net)
367{
368 net->core.sysctl_somaxconn = SOMAXCONN;
369 return 0;
370}
371
372static struct pernet_operations net_defaults_ops = {
373 .init = net_defaults_init_net,
374};
375
376static __init int net_defaults_init(void)
377{
378 if (register_pernet_subsys(&net_defaults_ops))
379 panic("Cannot initialize net default settings");
380
381 return 0;
382}
383
384core_initcall(net_defaults_init);
385
386#ifdef CONFIG_NET_NS
387static struct ucounts *inc_net_namespaces(struct user_namespace *ns)
388{
389 return inc_ucount(ns, current_euid(), UCOUNT_NET_NAMESPACES);
390}
391
392static void dec_net_namespaces(struct ucounts *ucounts)
393{
394 dec_ucount(ucounts, UCOUNT_NET_NAMESPACES);
395}
396
397static struct kmem_cache *net_cachep __ro_after_init;
398static struct workqueue_struct *netns_wq;
399
400static struct net *net_alloc(void)
401{
402 struct net *net = NULL;
403 struct net_generic *ng;
404
405 ng = net_alloc_generic();
406 if (!ng)
407 goto out;
408
409 net = kmem_cache_zalloc(net_cachep, GFP_KERNEL);
410 if (!net)
411 goto out_free;
412
413#ifdef CONFIG_KEYS
414 net->key_domain = kzalloc(sizeof(struct key_tag), GFP_KERNEL);
415 if (!net->key_domain)
416 goto out_free_2;
417 refcount_set(&net->key_domain->usage, 1);
418#endif
419
420 rcu_assign_pointer(net->gen, ng);
421out:
422 return net;
423
424#ifdef CONFIG_KEYS
425out_free_2:
426 kmem_cache_free(net_cachep, net);
427 net = NULL;
428#endif
429out_free:
430 kfree(ng);
431 goto out;
432}
433
434static void net_free(struct net *net)
435{
436 kfree(rcu_access_pointer(net->gen));
437 kmem_cache_free(net_cachep, net);
438}
439
440void net_drop_ns(void *p)
441{
442 struct net *ns = p;
443 if (ns && refcount_dec_and_test(&ns->passive))
444 net_free(ns);
445}
446
447struct net *copy_net_ns(unsigned long flags,
448 struct user_namespace *user_ns, struct net *old_net)
449{
450 struct ucounts *ucounts;
451 struct net *net;
452 int rv;
453
454 if (!(flags & CLONE_NEWNET))
455 return get_net(old_net);
456
457 ucounts = inc_net_namespaces(user_ns);
458 if (!ucounts)
459 return ERR_PTR(-ENOSPC);
460
461 net = net_alloc();
462 if (!net) {
463 rv = -ENOMEM;
464 goto dec_ucounts;
465 }
466 refcount_set(&net->passive, 1);
467 net->ucounts = ucounts;
468 get_user_ns(user_ns);
469
470 rv = down_read_killable(&pernet_ops_rwsem);
471 if (rv < 0)
472 goto put_userns;
473
474 rv = setup_net(net, user_ns);
475
476 up_read(&pernet_ops_rwsem);
477
478 if (rv < 0) {
479put_userns:
480 key_remove_domain(net->key_domain);
481 put_user_ns(user_ns);
482 net_drop_ns(net);
483dec_ucounts:
484 dec_net_namespaces(ucounts);
485 return ERR_PTR(rv);
486 }
487 return net;
488}
489
490/**
491 * net_ns_get_ownership - get sysfs ownership data for @net
492 * @net: network namespace in question (can be NULL)
493 * @uid: kernel user ID for sysfs objects
494 * @gid: kernel group ID for sysfs objects
495 *
496 * Returns the uid/gid pair of root in the user namespace associated with the
497 * given network namespace.
498 */
499void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid)
500{
501 if (net) {
502 kuid_t ns_root_uid = make_kuid(net->user_ns, 0);
503 kgid_t ns_root_gid = make_kgid(net->user_ns, 0);
504
505 if (uid_valid(ns_root_uid))
506 *uid = ns_root_uid;
507
508 if (gid_valid(ns_root_gid))
509 *gid = ns_root_gid;
510 } else {
511 *uid = GLOBAL_ROOT_UID;
512 *gid = GLOBAL_ROOT_GID;
513 }
514}
515EXPORT_SYMBOL_GPL(net_ns_get_ownership);
516
517static void unhash_nsid(struct net *net, struct net *last)
518{
519 struct net *tmp;
520 /* This function is only called from cleanup_net() work,
521 * and this work is the only process, that may delete
522 * a net from net_namespace_list. So, when the below
523 * is executing, the list may only grow. Thus, we do not
524 * use for_each_net_rcu() or net_rwsem.
525 */
526 for_each_net(tmp) {
527 int id;
528
529 spin_lock_bh(&tmp->nsid_lock);
530 id = __peernet2id(tmp, net);
531 if (id >= 0)
532 idr_remove(&tmp->netns_ids, id);
533 spin_unlock_bh(&tmp->nsid_lock);
534 if (id >= 0)
535 rtnl_net_notifyid(tmp, RTM_DELNSID, id, 0, NULL,
536 GFP_KERNEL);
537 if (tmp == last)
538 break;
539 }
540 spin_lock_bh(&net->nsid_lock);
541 idr_destroy(&net->netns_ids);
542 spin_unlock_bh(&net->nsid_lock);
543}
544
545static LLIST_HEAD(cleanup_list);
546
547static void cleanup_net(struct work_struct *work)
548{
549 const struct pernet_operations *ops;
550 struct net *net, *tmp, *last;
551 struct llist_node *net_kill_list;
552 LIST_HEAD(net_exit_list);
553
554 /* Atomically snapshot the list of namespaces to cleanup */
555 net_kill_list = llist_del_all(&cleanup_list);
556
557 down_read(&pernet_ops_rwsem);
558
559 /* Don't let anyone else find us. */
560 down_write(&net_rwsem);
561 llist_for_each_entry(net, net_kill_list, cleanup_list)
562 list_del_rcu(&net->list);
563 /* Cache last net. After we unlock rtnl, no one new net
564 * added to net_namespace_list can assign nsid pointer
565 * to a net from net_kill_list (see peernet2id_alloc()).
566 * So, we skip them in unhash_nsid().
567 *
568 * Note, that unhash_nsid() does not delete nsid links
569 * between net_kill_list's nets, as they've already
570 * deleted from net_namespace_list. But, this would be
571 * useless anyway, as netns_ids are destroyed there.
572 */
573 last = list_last_entry(&net_namespace_list, struct net, list);
574 up_write(&net_rwsem);
575
576 llist_for_each_entry(net, net_kill_list, cleanup_list) {
577 unhash_nsid(net, last);
578 list_add_tail(&net->exit_list, &net_exit_list);
579 }
580
581 /* Run all of the network namespace pre_exit methods */
582 list_for_each_entry_reverse(ops, &pernet_list, list)
583 ops_pre_exit_list(ops, &net_exit_list);
584
585 /*
586 * Another CPU might be rcu-iterating the list, wait for it.
587 * This needs to be before calling the exit() notifiers, so
588 * the rcu_barrier() below isn't sufficient alone.
589 * Also the pre_exit() and exit() methods need this barrier.
590 */
591 synchronize_rcu();
592
593 /* Run all of the network namespace exit methods */
594 list_for_each_entry_reverse(ops, &pernet_list, list)
595 ops_exit_list(ops, &net_exit_list);
596
597 /* Free the net generic variables */
598 list_for_each_entry_reverse(ops, &pernet_list, list)
599 ops_free_list(ops, &net_exit_list);
600
601 up_read(&pernet_ops_rwsem);
602
603 /* Ensure there are no outstanding rcu callbacks using this
604 * network namespace.
605 */
606 rcu_barrier();
607
608 /* Finally it is safe to free my network namespace structure */
609 list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
610 list_del_init(&net->exit_list);
611 dec_net_namespaces(net->ucounts);
612 key_remove_domain(net->key_domain);
613 put_user_ns(net->user_ns);
614 net_drop_ns(net);
615 }
616}
617
618/**
619 * net_ns_barrier - wait until concurrent net_cleanup_work is done
620 *
621 * cleanup_net runs from work queue and will first remove namespaces
622 * from the global list, then run net exit functions.
623 *
624 * Call this in module exit path to make sure that all netns
625 * ->exit ops have been invoked before the function is removed.
626 */
627void net_ns_barrier(void)
628{
629 down_write(&pernet_ops_rwsem);
630 up_write(&pernet_ops_rwsem);
631}
632EXPORT_SYMBOL(net_ns_barrier);
633
634static DECLARE_WORK(net_cleanup_work, cleanup_net);
635
636void __put_net(struct net *net)
637{
638 /* Cleanup the network namespace in process context */
639 if (llist_add(&net->cleanup_list, &cleanup_list))
640 queue_work(netns_wq, &net_cleanup_work);
641}
642EXPORT_SYMBOL_GPL(__put_net);
643
644/**
645 * get_net_ns - increment the refcount of the network namespace
646 * @ns: common namespace (net)
647 *
648 * Returns the net's common namespace.
649 */
650struct ns_common *get_net_ns(struct ns_common *ns)
651{
652 return &get_net(container_of(ns, struct net, ns))->ns;
653}
654EXPORT_SYMBOL_GPL(get_net_ns);
655
656struct net *get_net_ns_by_fd(int fd)
657{
658 struct file *file;
659 struct ns_common *ns;
660 struct net *net;
661
662 file = proc_ns_fget(fd);
663 if (IS_ERR(file))
664 return ERR_CAST(file);
665
666 ns = get_proc_ns(file_inode(file));
667 if (ns->ops == &netns_operations)
668 net = get_net(container_of(ns, struct net, ns));
669 else
670 net = ERR_PTR(-EINVAL);
671
672 fput(file);
673 return net;
674}
675EXPORT_SYMBOL_GPL(get_net_ns_by_fd);
676#endif
677
678struct net *get_net_ns_by_pid(pid_t pid)
679{
680 struct task_struct *tsk;
681 struct net *net;
682
683 /* Lookup the network namespace */
684 net = ERR_PTR(-ESRCH);
685 rcu_read_lock();
686 tsk = find_task_by_vpid(pid);
687 if (tsk) {
688 struct nsproxy *nsproxy;
689 task_lock(tsk);
690 nsproxy = tsk->nsproxy;
691 if (nsproxy)
692 net = get_net(nsproxy->net_ns);
693 task_unlock(tsk);
694 }
695 rcu_read_unlock();
696 return net;
697}
698EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
699
700static __net_init int net_ns_net_init(struct net *net)
701{
702#ifdef CONFIG_NET_NS
703 net->ns.ops = &netns_operations;
704#endif
705 return ns_alloc_inum(&net->ns);
706}
707
708static __net_exit void net_ns_net_exit(struct net *net)
709{
710 ns_free_inum(&net->ns);
711}
712
713static struct pernet_operations __net_initdata net_ns_ops = {
714 .init = net_ns_net_init,
715 .exit = net_ns_net_exit,
716};
717
718static const struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = {
719 [NETNSA_NONE] = { .type = NLA_UNSPEC },
720 [NETNSA_NSID] = { .type = NLA_S32 },
721 [NETNSA_PID] = { .type = NLA_U32 },
722 [NETNSA_FD] = { .type = NLA_U32 },
723 [NETNSA_TARGET_NSID] = { .type = NLA_S32 },
724};
725
726static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh,
727 struct netlink_ext_ack *extack)
728{
729 struct net *net = sock_net(skb->sk);
730 struct nlattr *tb[NETNSA_MAX + 1];
731 struct nlattr *nla;
732 struct net *peer;
733 int nsid, err;
734
735 err = nlmsg_parse_deprecated(nlh, sizeof(struct rtgenmsg), tb,
736 NETNSA_MAX, rtnl_net_policy, extack);
737 if (err < 0)
738 return err;
739 if (!tb[NETNSA_NSID]) {
740 NL_SET_ERR_MSG(extack, "nsid is missing");
741 return -EINVAL;
742 }
743 nsid = nla_get_s32(tb[NETNSA_NSID]);
744
745 if (tb[NETNSA_PID]) {
746 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
747 nla = tb[NETNSA_PID];
748 } else if (tb[NETNSA_FD]) {
749 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
750 nla = tb[NETNSA_FD];
751 } else {
752 NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
753 return -EINVAL;
754 }
755 if (IS_ERR(peer)) {
756 NL_SET_BAD_ATTR(extack, nla);
757 NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
758 return PTR_ERR(peer);
759 }
760
761 spin_lock_bh(&net->nsid_lock);
762 if (__peernet2id(net, peer) >= 0) {
763 spin_unlock_bh(&net->nsid_lock);
764 err = -EEXIST;
765 NL_SET_BAD_ATTR(extack, nla);
766 NL_SET_ERR_MSG(extack,
767 "Peer netns already has a nsid assigned");
768 goto out;
769 }
770
771 err = alloc_netid(net, peer, nsid);
772 spin_unlock_bh(&net->nsid_lock);
773 if (err >= 0) {
774 rtnl_net_notifyid(net, RTM_NEWNSID, err, NETLINK_CB(skb).portid,
775 nlh, GFP_KERNEL);
776 err = 0;
777 } else if (err == -ENOSPC && nsid >= 0) {
778 err = -EEXIST;
779 NL_SET_BAD_ATTR(extack, tb[NETNSA_NSID]);
780 NL_SET_ERR_MSG(extack, "The specified nsid is already used");
781 }
782out:
783 put_net(peer);
784 return err;
785}
786
787static int rtnl_net_get_size(void)
788{
789 return NLMSG_ALIGN(sizeof(struct rtgenmsg))
790 + nla_total_size(sizeof(s32)) /* NETNSA_NSID */
791 + nla_total_size(sizeof(s32)) /* NETNSA_CURRENT_NSID */
792 ;
793}
794
795struct net_fill_args {
796 u32 portid;
797 u32 seq;
798 int flags;
799 int cmd;
800 int nsid;
801 bool add_ref;
802 int ref_nsid;
803};
804
805static int rtnl_net_fill(struct sk_buff *skb, struct net_fill_args *args)
806{
807 struct nlmsghdr *nlh;
808 struct rtgenmsg *rth;
809
810 nlh = nlmsg_put(skb, args->portid, args->seq, args->cmd, sizeof(*rth),
811 args->flags);
812 if (!nlh)
813 return -EMSGSIZE;
814
815 rth = nlmsg_data(nlh);
816 rth->rtgen_family = AF_UNSPEC;
817
818 if (nla_put_s32(skb, NETNSA_NSID, args->nsid))
819 goto nla_put_failure;
820
821 if (args->add_ref &&
822 nla_put_s32(skb, NETNSA_CURRENT_NSID, args->ref_nsid))
823 goto nla_put_failure;
824
825 nlmsg_end(skb, nlh);
826 return 0;
827
828nla_put_failure:
829 nlmsg_cancel(skb, nlh);
830 return -EMSGSIZE;
831}
832
833static int rtnl_net_valid_getid_req(struct sk_buff *skb,
834 const struct nlmsghdr *nlh,
835 struct nlattr **tb,
836 struct netlink_ext_ack *extack)
837{
838 int i, err;
839
840 if (!netlink_strict_get_check(skb))
841 return nlmsg_parse_deprecated(nlh, sizeof(struct rtgenmsg),
842 tb, NETNSA_MAX, rtnl_net_policy,
843 extack);
844
845 err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct rtgenmsg), tb,
846 NETNSA_MAX, rtnl_net_policy,
847 extack);
848 if (err)
849 return err;
850
851 for (i = 0; i <= NETNSA_MAX; i++) {
852 if (!tb[i])
853 continue;
854
855 switch (i) {
856 case NETNSA_PID:
857 case NETNSA_FD:
858 case NETNSA_NSID:
859 case NETNSA_TARGET_NSID:
860 break;
861 default:
862 NL_SET_ERR_MSG(extack, "Unsupported attribute in peer netns getid request");
863 return -EINVAL;
864 }
865 }
866
867 return 0;
868}
869
870static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh,
871 struct netlink_ext_ack *extack)
872{
873 struct net *net = sock_net(skb->sk);
874 struct nlattr *tb[NETNSA_MAX + 1];
875 struct net_fill_args fillargs = {
876 .portid = NETLINK_CB(skb).portid,
877 .seq = nlh->nlmsg_seq,
878 .cmd = RTM_NEWNSID,
879 };
880 struct net *peer, *target = net;
881 struct nlattr *nla;
882 struct sk_buff *msg;
883 int err;
884
885 err = rtnl_net_valid_getid_req(skb, nlh, tb, extack);
886 if (err < 0)
887 return err;
888 if (tb[NETNSA_PID]) {
889 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
890 nla = tb[NETNSA_PID];
891 } else if (tb[NETNSA_FD]) {
892 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
893 nla = tb[NETNSA_FD];
894 } else if (tb[NETNSA_NSID]) {
895 peer = get_net_ns_by_id(net, nla_get_s32(tb[NETNSA_NSID]));
896 if (!peer)
897 peer = ERR_PTR(-ENOENT);
898 nla = tb[NETNSA_NSID];
899 } else {
900 NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
901 return -EINVAL;
902 }
903
904 if (IS_ERR(peer)) {
905 NL_SET_BAD_ATTR(extack, nla);
906 NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
907 return PTR_ERR(peer);
908 }
909
910 if (tb[NETNSA_TARGET_NSID]) {
911 int id = nla_get_s32(tb[NETNSA_TARGET_NSID]);
912
913 target = rtnl_get_net_ns_capable(NETLINK_CB(skb).sk, id);
914 if (IS_ERR(target)) {
915 NL_SET_BAD_ATTR(extack, tb[NETNSA_TARGET_NSID]);
916 NL_SET_ERR_MSG(extack,
917 "Target netns reference is invalid");
918 err = PTR_ERR(target);
919 goto out;
920 }
921 fillargs.add_ref = true;
922 fillargs.ref_nsid = peernet2id(net, peer);
923 }
924
925 msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
926 if (!msg) {
927 err = -ENOMEM;
928 goto out;
929 }
930
931 fillargs.nsid = peernet2id(target, peer);
932 err = rtnl_net_fill(msg, &fillargs);
933 if (err < 0)
934 goto err_out;
935
936 err = rtnl_unicast(msg, net, NETLINK_CB(skb).portid);
937 goto out;
938
939err_out:
940 nlmsg_free(msg);
941out:
942 if (fillargs.add_ref)
943 put_net(target);
944 put_net(peer);
945 return err;
946}
947
948struct rtnl_net_dump_cb {
949 struct net *tgt_net;
950 struct net *ref_net;
951 struct sk_buff *skb;
952 struct net_fill_args fillargs;
953 int idx;
954 int s_idx;
955};
956
957/* Runs in RCU-critical section. */
958static int rtnl_net_dumpid_one(int id, void *peer, void *data)
959{
960 struct rtnl_net_dump_cb *net_cb = (struct rtnl_net_dump_cb *)data;
961 int ret;
962
963 if (net_cb->idx < net_cb->s_idx)
964 goto cont;
965
966 net_cb->fillargs.nsid = id;
967 if (net_cb->fillargs.add_ref)
968 net_cb->fillargs.ref_nsid = __peernet2id(net_cb->ref_net, peer);
969 ret = rtnl_net_fill(net_cb->skb, &net_cb->fillargs);
970 if (ret < 0)
971 return ret;
972
973cont:
974 net_cb->idx++;
975 return 0;
976}
977
978static int rtnl_valid_dump_net_req(const struct nlmsghdr *nlh, struct sock *sk,
979 struct rtnl_net_dump_cb *net_cb,
980 struct netlink_callback *cb)
981{
982 struct netlink_ext_ack *extack = cb->extack;
983 struct nlattr *tb[NETNSA_MAX + 1];
984 int err, i;
985
986 err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct rtgenmsg), tb,
987 NETNSA_MAX, rtnl_net_policy,
988 extack);
989 if (err < 0)
990 return err;
991
992 for (i = 0; i <= NETNSA_MAX; i++) {
993 if (!tb[i])
994 continue;
995
996 if (i == NETNSA_TARGET_NSID) {
997 struct net *net;
998
999 net = rtnl_get_net_ns_capable(sk, nla_get_s32(tb[i]));
1000 if (IS_ERR(net)) {
1001 NL_SET_BAD_ATTR(extack, tb[i]);
1002 NL_SET_ERR_MSG(extack,
1003 "Invalid target network namespace id");
1004 return PTR_ERR(net);
1005 }
1006 net_cb->fillargs.add_ref = true;
1007 net_cb->ref_net = net_cb->tgt_net;
1008 net_cb->tgt_net = net;
1009 } else {
1010 NL_SET_BAD_ATTR(extack, tb[i]);
1011 NL_SET_ERR_MSG(extack,
1012 "Unsupported attribute in dump request");
1013 return -EINVAL;
1014 }
1015 }
1016
1017 return 0;
1018}
1019
1020static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb)
1021{
1022 struct rtnl_net_dump_cb net_cb = {
1023 .tgt_net = sock_net(skb->sk),
1024 .skb = skb,
1025 .fillargs = {
1026 .portid = NETLINK_CB(cb->skb).portid,
1027 .seq = cb->nlh->nlmsg_seq,
1028 .flags = NLM_F_MULTI,
1029 .cmd = RTM_NEWNSID,
1030 },
1031 .idx = 0,
1032 .s_idx = cb->args[0],
1033 };
1034 int err = 0;
1035
1036 if (cb->strict_check) {
1037 err = rtnl_valid_dump_net_req(cb->nlh, skb->sk, &net_cb, cb);
1038 if (err < 0)
1039 goto end;
1040 }
1041
1042 rcu_read_lock();
1043 idr_for_each(&net_cb.tgt_net->netns_ids, rtnl_net_dumpid_one, &net_cb);
1044 rcu_read_unlock();
1045
1046 cb->args[0] = net_cb.idx;
1047end:
1048 if (net_cb.fillargs.add_ref)
1049 put_net(net_cb.tgt_net);
1050 return err < 0 ? err : skb->len;
1051}
1052
1053static void rtnl_net_notifyid(struct net *net, int cmd, int id, u32 portid,
1054 struct nlmsghdr *nlh, gfp_t gfp)
1055{
1056 struct net_fill_args fillargs = {
1057 .portid = portid,
1058 .seq = nlh ? nlh->nlmsg_seq : 0,
1059 .cmd = cmd,
1060 .nsid = id,
1061 };
1062 struct sk_buff *msg;
1063 int err = -ENOMEM;
1064
1065 msg = nlmsg_new(rtnl_net_get_size(), gfp);
1066 if (!msg)
1067 goto out;
1068
1069 err = rtnl_net_fill(msg, &fillargs);
1070 if (err < 0)
1071 goto err_out;
1072
1073 rtnl_notify(msg, net, portid, RTNLGRP_NSID, nlh, gfp);
1074 return;
1075
1076err_out:
1077 nlmsg_free(msg);
1078out:
1079 rtnl_set_sk_err(net, RTNLGRP_NSID, err);
1080}
1081
1082static int __init net_ns_init(void)
1083{
1084 struct net_generic *ng;
1085
1086#ifdef CONFIG_NET_NS
1087 net_cachep = kmem_cache_create("net_namespace", sizeof(struct net),
1088 SMP_CACHE_BYTES,
1089 SLAB_PANIC|SLAB_ACCOUNT, NULL);
1090
1091 /* Create workqueue for cleanup */
1092 netns_wq = create_singlethread_workqueue("netns");
1093 if (!netns_wq)
1094 panic("Could not create netns workq");
1095#endif
1096
1097 ng = net_alloc_generic();
1098 if (!ng)
1099 panic("Could not allocate generic netns");
1100
1101 rcu_assign_pointer(init_net.gen, ng);
1102
1103 down_write(&pernet_ops_rwsem);
1104 if (setup_net(&init_net, &init_user_ns))
1105 panic("Could not setup the initial network namespace");
1106
1107 init_net_initialized = true;
1108 up_write(&pernet_ops_rwsem);
1109
1110 if (register_pernet_subsys(&net_ns_ops))
1111 panic("Could not register network namespace subsystems");
1112
1113 rtnl_register(PF_UNSPEC, RTM_NEWNSID, rtnl_net_newid, NULL,
1114 RTNL_FLAG_DOIT_UNLOCKED);
1115 rtnl_register(PF_UNSPEC, RTM_GETNSID, rtnl_net_getid, rtnl_net_dumpid,
1116 RTNL_FLAG_DOIT_UNLOCKED);
1117
1118 return 0;
1119}
1120
1121pure_initcall(net_ns_init);
1122
1123#ifdef CONFIG_NET_NS
1124static int __register_pernet_operations(struct list_head *list,
1125 struct pernet_operations *ops)
1126{
1127 struct net *net;
1128 int error;
1129 LIST_HEAD(net_exit_list);
1130
1131 list_add_tail(&ops->list, list);
1132 if (ops->init || (ops->id && ops->size)) {
1133 /* We held write locked pernet_ops_rwsem, and parallel
1134 * setup_net() and cleanup_net() are not possible.
1135 */
1136 for_each_net(net) {
1137 error = ops_init(ops, net);
1138 if (error)
1139 goto out_undo;
1140 list_add_tail(&net->exit_list, &net_exit_list);
1141 }
1142 }
1143 return 0;
1144
1145out_undo:
1146 /* If I have an error cleanup all namespaces I initialized */
1147 list_del(&ops->list);
1148 ops_pre_exit_list(ops, &net_exit_list);
1149 synchronize_rcu();
1150 ops_exit_list(ops, &net_exit_list);
1151 ops_free_list(ops, &net_exit_list);
1152 return error;
1153}
1154
1155static void __unregister_pernet_operations(struct pernet_operations *ops)
1156{
1157 struct net *net;
1158 LIST_HEAD(net_exit_list);
1159
1160 list_del(&ops->list);
1161 /* See comment in __register_pernet_operations() */
1162 for_each_net(net)
1163 list_add_tail(&net->exit_list, &net_exit_list);
1164 ops_pre_exit_list(ops, &net_exit_list);
1165 synchronize_rcu();
1166 ops_exit_list(ops, &net_exit_list);
1167 ops_free_list(ops, &net_exit_list);
1168}
1169
1170#else
1171
1172static int __register_pernet_operations(struct list_head *list,
1173 struct pernet_operations *ops)
1174{
1175 if (!init_net_initialized) {
1176 list_add_tail(&ops->list, list);
1177 return 0;
1178 }
1179
1180 return ops_init(ops, &init_net);
1181}
1182
1183static void __unregister_pernet_operations(struct pernet_operations *ops)
1184{
1185 if (!init_net_initialized) {
1186 list_del(&ops->list);
1187 } else {
1188 LIST_HEAD(net_exit_list);
1189 list_add(&init_net.exit_list, &net_exit_list);
1190 ops_pre_exit_list(ops, &net_exit_list);
1191 synchronize_rcu();
1192 ops_exit_list(ops, &net_exit_list);
1193 ops_free_list(ops, &net_exit_list);
1194 }
1195}
1196
1197#endif /* CONFIG_NET_NS */
1198
1199static DEFINE_IDA(net_generic_ids);
1200
1201static int register_pernet_operations(struct list_head *list,
1202 struct pernet_operations *ops)
1203{
1204 int error;
1205
1206 if (ops->id) {
1207 error = ida_alloc_min(&net_generic_ids, MIN_PERNET_OPS_ID,
1208 GFP_KERNEL);
1209 if (error < 0)
1210 return error;
1211 *ops->id = error;
1212 max_gen_ptrs = max(max_gen_ptrs, *ops->id + 1);
1213 }
1214 error = __register_pernet_operations(list, ops);
1215 if (error) {
1216 rcu_barrier();
1217 if (ops->id)
1218 ida_free(&net_generic_ids, *ops->id);
1219 }
1220
1221 return error;
1222}
1223
1224static void unregister_pernet_operations(struct pernet_operations *ops)
1225{
1226 __unregister_pernet_operations(ops);
1227 rcu_barrier();
1228 if (ops->id)
1229 ida_free(&net_generic_ids, *ops->id);
1230}
1231
1232/**
1233 * register_pernet_subsys - register a network namespace subsystem
1234 * @ops: pernet operations structure for the subsystem
1235 *
1236 * Register a subsystem which has init and exit functions
1237 * that are called when network namespaces are created and
1238 * destroyed respectively.
1239 *
1240 * When registered all network namespace init functions are
1241 * called for every existing network namespace. Allowing kernel
1242 * modules to have a race free view of the set of network namespaces.
1243 *
1244 * When a new network namespace is created all of the init
1245 * methods are called in the order in which they were registered.
1246 *
1247 * When a network namespace is destroyed all of the exit methods
1248 * are called in the reverse of the order with which they were
1249 * registered.
1250 */
1251int register_pernet_subsys(struct pernet_operations *ops)
1252{
1253 int error;
1254 down_write(&pernet_ops_rwsem);
1255 error = register_pernet_operations(first_device, ops);
1256 up_write(&pernet_ops_rwsem);
1257 return error;
1258}
1259EXPORT_SYMBOL_GPL(register_pernet_subsys);
1260
1261/**
1262 * unregister_pernet_subsys - unregister a network namespace subsystem
1263 * @ops: pernet operations structure to manipulate
1264 *
1265 * Remove the pernet operations structure from the list to be
1266 * used when network namespaces are created or destroyed. In
1267 * addition run the exit method for all existing network
1268 * namespaces.
1269 */
1270void unregister_pernet_subsys(struct pernet_operations *ops)
1271{
1272 down_write(&pernet_ops_rwsem);
1273 unregister_pernet_operations(ops);
1274 up_write(&pernet_ops_rwsem);
1275}
1276EXPORT_SYMBOL_GPL(unregister_pernet_subsys);
1277
1278/**
1279 * register_pernet_device - register a network namespace device
1280 * @ops: pernet operations structure for the subsystem
1281 *
1282 * Register a device which has init and exit functions
1283 * that are called when network namespaces are created and
1284 * destroyed respectively.
1285 *
1286 * When registered all network namespace init functions are
1287 * called for every existing network namespace. Allowing kernel
1288 * modules to have a race free view of the set of network namespaces.
1289 *
1290 * When a new network namespace is created all of the init
1291 * methods are called in the order in which they were registered.
1292 *
1293 * When a network namespace is destroyed all of the exit methods
1294 * are called in the reverse of the order with which they were
1295 * registered.
1296 */
1297int register_pernet_device(struct pernet_operations *ops)
1298{
1299 int error;
1300 down_write(&pernet_ops_rwsem);
1301 error = register_pernet_operations(&pernet_list, ops);
1302 if (!error && (first_device == &pernet_list))
1303 first_device = &ops->list;
1304 up_write(&pernet_ops_rwsem);
1305 return error;
1306}
1307EXPORT_SYMBOL_GPL(register_pernet_device);
1308
1309/**
1310 * unregister_pernet_device - unregister a network namespace netdevice
1311 * @ops: pernet operations structure to manipulate
1312 *
1313 * Remove the pernet operations structure from the list to be
1314 * used when network namespaces are created or destroyed. In
1315 * addition run the exit method for all existing network
1316 * namespaces.
1317 */
1318void unregister_pernet_device(struct pernet_operations *ops)
1319{
1320 down_write(&pernet_ops_rwsem);
1321 if (&ops->list == first_device)
1322 first_device = first_device->next;
1323 unregister_pernet_operations(ops);
1324 up_write(&pernet_ops_rwsem);
1325}
1326EXPORT_SYMBOL_GPL(unregister_pernet_device);
1327
1328#ifdef CONFIG_NET_NS
1329static struct ns_common *netns_get(struct task_struct *task)
1330{
1331 struct net *net = NULL;
1332 struct nsproxy *nsproxy;
1333
1334 task_lock(task);
1335 nsproxy = task->nsproxy;
1336 if (nsproxy)
1337 net = get_net(nsproxy->net_ns);
1338 task_unlock(task);
1339
1340 return net ? &net->ns : NULL;
1341}
1342
1343static inline struct net *to_net_ns(struct ns_common *ns)
1344{
1345 return container_of(ns, struct net, ns);
1346}
1347
1348static void netns_put(struct ns_common *ns)
1349{
1350 put_net(to_net_ns(ns));
1351}
1352
1353static int netns_install(struct nsset *nsset, struct ns_common *ns)
1354{
1355 struct nsproxy *nsproxy = nsset->nsproxy;
1356 struct net *net = to_net_ns(ns);
1357
1358 if (!ns_capable(net->user_ns, CAP_SYS_ADMIN) ||
1359 !ns_capable(nsset->cred->user_ns, CAP_SYS_ADMIN))
1360 return -EPERM;
1361
1362 put_net(nsproxy->net_ns);
1363 nsproxy->net_ns = get_net(net);
1364 return 0;
1365}
1366
1367static struct user_namespace *netns_owner(struct ns_common *ns)
1368{
1369 return to_net_ns(ns)->user_ns;
1370}
1371
1372const struct proc_ns_operations netns_operations = {
1373 .name = "net",
1374 .type = CLONE_NEWNET,
1375 .get = netns_get,
1376 .put = netns_put,
1377 .install = netns_install,
1378 .owner = netns_owner,
1379};
1380#endif