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
28
29
30static LIST_HEAD(pernet_list);
31static struct list_head *first_device = &pernet_list;
32DEFINE_MUTEX(net_mutex);
33
34LIST_HEAD(net_namespace_list);
35EXPORT_SYMBOL_GPL(net_namespace_list);
36
37struct net init_net = {
38 .count = ATOMIC_INIT(1),
39 .dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head),
40};
41EXPORT_SYMBOL(init_net);
42
43static bool init_net_initialized;
44
45#define MIN_PERNET_OPS_ID \
46 ((sizeof(struct net_generic) + sizeof(void *) - 1) / sizeof(void *))
47
48#define INITIAL_NET_GEN_PTRS 13
49
50static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS;
51
52static struct net_generic *net_alloc_generic(void)
53{
54 struct net_generic *ng;
55 unsigned int generic_size = offsetof(struct net_generic, ptr[max_gen_ptrs]);
56
57 ng = kzalloc(generic_size, GFP_KERNEL);
58 if (ng)
59 ng->s.len = max_gen_ptrs;
60
61 return ng;
62}
63
64static int net_assign_generic(struct net *net, unsigned int id, void *data)
65{
66 struct net_generic *ng, *old_ng;
67
68 BUG_ON(!mutex_is_locked(&net_mutex));
69 BUG_ON(id < MIN_PERNET_OPS_ID);
70
71 old_ng = rcu_dereference_protected(net->gen,
72 lockdep_is_held(&net_mutex));
73 if (old_ng->s.len > id) {
74 old_ng->ptr[id] = data;
75 return 0;
76 }
77
78 ng = net_alloc_generic();
79 if (ng == NULL)
80 return -ENOMEM;
81
82
83
84
85
86
87
88
89
90
91
92
93 memcpy(&ng->ptr[MIN_PERNET_OPS_ID], &old_ng->ptr[MIN_PERNET_OPS_ID],
94 (old_ng->s.len - MIN_PERNET_OPS_ID) * sizeof(void *));
95 ng->ptr[id] = data;
96
97 rcu_assign_pointer(net->gen, ng);
98 kfree_rcu(old_ng, s.rcu);
99 return 0;
100}
101
102static int ops_init(const struct pernet_operations *ops, struct net *net)
103{
104 int err = -ENOMEM;
105 void *data = NULL;
106
107 if (ops->id && ops->size) {
108 data = kzalloc(ops->size, GFP_KERNEL);
109 if (!data)
110 goto out;
111
112 err = net_assign_generic(net, *ops->id, data);
113 if (err)
114 goto cleanup;
115 }
116 err = 0;
117 if (ops->init)
118 err = ops->init(net);
119 if (!err)
120 return 0;
121
122cleanup:
123 kfree(data);
124
125out:
126 return err;
127}
128
129static void ops_free(const struct pernet_operations *ops, struct net *net)
130{
131 if (ops->id && ops->size) {
132 kfree(net_generic(net, *ops->id));
133 }
134}
135
136static void ops_exit_list(const struct pernet_operations *ops,
137 struct list_head *net_exit_list)
138{
139 struct net *net;
140 if (ops->exit) {
141 list_for_each_entry(net, net_exit_list, exit_list)
142 ops->exit(net);
143 }
144 if (ops->exit_batch)
145 ops->exit_batch(net_exit_list);
146}
147
148static void ops_free_list(const struct pernet_operations *ops,
149 struct list_head *net_exit_list)
150{
151 struct net *net;
152 if (ops->size && ops->id) {
153 list_for_each_entry(net, net_exit_list, exit_list)
154 ops_free(ops, net);
155 }
156}
157
158
159static int alloc_netid(struct net *net, struct net *peer, int reqid)
160{
161 int min = 0, max = 0;
162
163 if (reqid >= 0) {
164 min = reqid;
165 max = reqid + 1;
166 }
167
168 return idr_alloc(&net->netns_ids, peer, min, max, GFP_ATOMIC);
169}
170
171
172
173
174
175
176#define NET_ID_ZERO -1
177static int net_eq_idr(int id, void *net, void *peer)
178{
179 if (net_eq(net, peer))
180 return id ? : NET_ID_ZERO;
181 return 0;
182}
183
184
185
186
187
188static int __peernet2id_alloc(struct net *net, struct net *peer, bool *alloc)
189{
190 int id = idr_for_each(&net->netns_ids, net_eq_idr, peer);
191 bool alloc_it = *alloc;
192
193 *alloc = false;
194
195
196 if (id == NET_ID_ZERO)
197 return 0;
198 if (id > 0)
199 return id;
200
201 if (alloc_it) {
202 id = alloc_netid(net, peer, -1);
203 *alloc = true;
204 return id >= 0 ? id : NETNSA_NSID_NOT_ASSIGNED;
205 }
206
207 return NETNSA_NSID_NOT_ASSIGNED;
208}
209
210
211static int __peernet2id(struct net *net, struct net *peer)
212{
213 bool no = false;
214
215 return __peernet2id_alloc(net, peer, &no);
216}
217
218static void rtnl_net_notifyid(struct net *net, int cmd, int id);
219
220
221
222int peernet2id_alloc(struct net *net, struct net *peer)
223{
224 bool alloc;
225 int id;
226
227 if (atomic_read(&net->count) == 0)
228 return NETNSA_NSID_NOT_ASSIGNED;
229 spin_lock_bh(&net->nsid_lock);
230 alloc = atomic_read(&peer->count) == 0 ? false : true;
231 id = __peernet2id_alloc(net, peer, &alloc);
232 spin_unlock_bh(&net->nsid_lock);
233 if (alloc && id >= 0)
234 rtnl_net_notifyid(net, RTM_NEWNSID, id);
235 return id;
236}
237
238
239int peernet2id(struct net *net, struct net *peer)
240{
241 int id;
242
243 spin_lock_bh(&net->nsid_lock);
244 id = __peernet2id(net, peer);
245 spin_unlock_bh(&net->nsid_lock);
246 return id;
247}
248EXPORT_SYMBOL(peernet2id);
249
250
251
252
253bool peernet_has_id(struct net *net, struct net *peer)
254{
255 return peernet2id(net, peer) >= 0;
256}
257
258struct net *get_net_ns_by_id(struct net *net, int id)
259{
260 struct net *peer;
261
262 if (id < 0)
263 return NULL;
264
265 rcu_read_lock();
266 spin_lock_bh(&net->nsid_lock);
267 peer = idr_find(&net->netns_ids, id);
268 if (peer)
269 get_net(peer);
270 spin_unlock_bh(&net->nsid_lock);
271 rcu_read_unlock();
272
273 return peer;
274}
275
276
277
278
279static __net_init int setup_net(struct net *net, struct user_namespace *user_ns)
280{
281
282 const struct pernet_operations *ops, *saved_ops;
283 int error = 0;
284 LIST_HEAD(net_exit_list);
285
286 atomic_set(&net->count, 1);
287 refcount_set(&net->passive, 1);
288 net->dev_base_seq = 1;
289 net->user_ns = user_ns;
290 idr_init(&net->netns_ids);
291 spin_lock_init(&net->nsid_lock);
292
293 list_for_each_entry(ops, &pernet_list, list) {
294 error = ops_init(ops, net);
295 if (error < 0)
296 goto out_undo;
297 }
298out:
299 return error;
300
301out_undo:
302
303
304
305 list_add(&net->exit_list, &net_exit_list);
306 saved_ops = ops;
307 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
308 ops_exit_list(ops, &net_exit_list);
309
310 ops = saved_ops;
311 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
312 ops_free_list(ops, &net_exit_list);
313
314 rcu_barrier();
315 goto out;
316}
317
318static int __net_init net_defaults_init_net(struct net *net)
319{
320 net->core.sysctl_somaxconn = SOMAXCONN;
321 return 0;
322}
323
324static struct pernet_operations net_defaults_ops = {
325 .init = net_defaults_init_net,
326};
327
328static __init int net_defaults_init(void)
329{
330 if (register_pernet_subsys(&net_defaults_ops))
331 panic("Cannot initialize net default settings");
332
333 return 0;
334}
335
336core_initcall(net_defaults_init);
337
338#ifdef CONFIG_NET_NS
339static struct ucounts *inc_net_namespaces(struct user_namespace *ns)
340{
341 return inc_ucount(ns, current_euid(), UCOUNT_NET_NAMESPACES);
342}
343
344static void dec_net_namespaces(struct ucounts *ucounts)
345{
346 dec_ucount(ucounts, UCOUNT_NET_NAMESPACES);
347}
348
349static struct kmem_cache *net_cachep;
350static struct workqueue_struct *netns_wq;
351
352static struct net *net_alloc(void)
353{
354 struct net *net = NULL;
355 struct net_generic *ng;
356
357 ng = net_alloc_generic();
358 if (!ng)
359 goto out;
360
361 net = kmem_cache_zalloc(net_cachep, GFP_KERNEL);
362 if (!net)
363 goto out_free;
364
365 rcu_assign_pointer(net->gen, ng);
366out:
367 return net;
368
369out_free:
370 kfree(ng);
371 goto out;
372}
373
374static void net_free(struct net *net)
375{
376 kfree(rcu_access_pointer(net->gen));
377 kmem_cache_free(net_cachep, net);
378}
379
380void net_drop_ns(void *p)
381{
382 struct net *ns = p;
383 if (ns && refcount_dec_and_test(&ns->passive))
384 net_free(ns);
385}
386
387struct net *copy_net_ns(unsigned long flags,
388 struct user_namespace *user_ns, struct net *old_net)
389{
390 struct ucounts *ucounts;
391 struct net *net;
392 int rv;
393
394 if (!(flags & CLONE_NEWNET))
395 return get_net(old_net);
396
397 ucounts = inc_net_namespaces(user_ns);
398 if (!ucounts)
399 return ERR_PTR(-ENOSPC);
400
401 net = net_alloc();
402 if (!net) {
403 dec_net_namespaces(ucounts);
404 return ERR_PTR(-ENOMEM);
405 }
406
407 get_user_ns(user_ns);
408
409 rv = mutex_lock_killable(&net_mutex);
410 if (rv < 0) {
411 net_free(net);
412 dec_net_namespaces(ucounts);
413 put_user_ns(user_ns);
414 return ERR_PTR(rv);
415 }
416
417 net->ucounts = ucounts;
418 rv = setup_net(net, user_ns);
419 if (rv == 0) {
420 rtnl_lock();
421 list_add_tail_rcu(&net->list, &net_namespace_list);
422 rtnl_unlock();
423 }
424 mutex_unlock(&net_mutex);
425 if (rv < 0) {
426 dec_net_namespaces(ucounts);
427 put_user_ns(user_ns);
428 net_drop_ns(net);
429 return ERR_PTR(rv);
430 }
431 return net;
432}
433
434static DEFINE_SPINLOCK(cleanup_list_lock);
435static LIST_HEAD(cleanup_list);
436
437static void cleanup_net(struct work_struct *work)
438{
439 const struct pernet_operations *ops;
440 struct net *net, *tmp;
441 struct list_head net_kill_list;
442 LIST_HEAD(net_exit_list);
443
444
445 spin_lock_irq(&cleanup_list_lock);
446 list_replace_init(&cleanup_list, &net_kill_list);
447 spin_unlock_irq(&cleanup_list_lock);
448
449 mutex_lock(&net_mutex);
450
451
452 rtnl_lock();
453 list_for_each_entry(net, &net_kill_list, cleanup_list) {
454 list_del_rcu(&net->list);
455 list_add_tail(&net->exit_list, &net_exit_list);
456 for_each_net(tmp) {
457 int id;
458
459 spin_lock_bh(&tmp->nsid_lock);
460 id = __peernet2id(tmp, net);
461 if (id >= 0)
462 idr_remove(&tmp->netns_ids, id);
463 spin_unlock_bh(&tmp->nsid_lock);
464 if (id >= 0)
465 rtnl_net_notifyid(tmp, RTM_DELNSID, id);
466 }
467 spin_lock_bh(&net->nsid_lock);
468 idr_destroy(&net->netns_ids);
469 spin_unlock_bh(&net->nsid_lock);
470
471 }
472 rtnl_unlock();
473
474
475
476
477
478
479 synchronize_rcu();
480
481
482 list_for_each_entry_reverse(ops, &pernet_list, list)
483 ops_exit_list(ops, &net_exit_list);
484
485
486 list_for_each_entry_reverse(ops, &pernet_list, list)
487 ops_free_list(ops, &net_exit_list);
488
489 mutex_unlock(&net_mutex);
490
491
492
493
494 rcu_barrier();
495
496
497 list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
498 list_del_init(&net->exit_list);
499 dec_net_namespaces(net->ucounts);
500 put_user_ns(net->user_ns);
501 net_drop_ns(net);
502 }
503}
504
505
506
507
508
509
510
511
512
513
514void net_ns_barrier(void)
515{
516 mutex_lock(&net_mutex);
517 mutex_unlock(&net_mutex);
518}
519EXPORT_SYMBOL(net_ns_barrier);
520
521static DECLARE_WORK(net_cleanup_work, cleanup_net);
522
523void __put_net(struct net *net)
524{
525
526 unsigned long flags;
527
528 spin_lock_irqsave(&cleanup_list_lock, flags);
529 list_add(&net->cleanup_list, &cleanup_list);
530 spin_unlock_irqrestore(&cleanup_list_lock, flags);
531
532 queue_work(netns_wq, &net_cleanup_work);
533}
534EXPORT_SYMBOL_GPL(__put_net);
535
536struct net *get_net_ns_by_fd(int fd)
537{
538 struct file *file;
539 struct ns_common *ns;
540 struct net *net;
541
542 file = proc_ns_fget(fd);
543 if (IS_ERR(file))
544 return ERR_CAST(file);
545
546 ns = get_proc_ns(file_inode(file));
547 if (ns->ops == &netns_operations)
548 net = get_net(container_of(ns, struct net, ns));
549 else
550 net = ERR_PTR(-EINVAL);
551
552 fput(file);
553 return net;
554}
555
556#else
557struct net *get_net_ns_by_fd(int fd)
558{
559 return ERR_PTR(-EINVAL);
560}
561#endif
562EXPORT_SYMBOL_GPL(get_net_ns_by_fd);
563
564struct net *get_net_ns_by_pid(pid_t pid)
565{
566 struct task_struct *tsk;
567 struct net *net;
568
569
570 net = ERR_PTR(-ESRCH);
571 rcu_read_lock();
572 tsk = find_task_by_vpid(pid);
573 if (tsk) {
574 struct nsproxy *nsproxy;
575 task_lock(tsk);
576 nsproxy = tsk->nsproxy;
577 if (nsproxy)
578 net = get_net(nsproxy->net_ns);
579 task_unlock(tsk);
580 }
581 rcu_read_unlock();
582 return net;
583}
584EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
585
586static __net_init int net_ns_net_init(struct net *net)
587{
588#ifdef CONFIG_NET_NS
589 net->ns.ops = &netns_operations;
590#endif
591 return ns_alloc_inum(&net->ns);
592}
593
594static __net_exit void net_ns_net_exit(struct net *net)
595{
596 ns_free_inum(&net->ns);
597}
598
599static struct pernet_operations __net_initdata net_ns_ops = {
600 .init = net_ns_net_init,
601 .exit = net_ns_net_exit,
602};
603
604static const struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = {
605 [NETNSA_NONE] = { .type = NLA_UNSPEC },
606 [NETNSA_NSID] = { .type = NLA_S32 },
607 [NETNSA_PID] = { .type = NLA_U32 },
608 [NETNSA_FD] = { .type = NLA_U32 },
609};
610
611static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh,
612 struct netlink_ext_ack *extack)
613{
614 struct net *net = sock_net(skb->sk);
615 struct nlattr *tb[NETNSA_MAX + 1];
616 struct nlattr *nla;
617 struct net *peer;
618 int nsid, err;
619
620 err = nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX,
621 rtnl_net_policy, extack);
622 if (err < 0)
623 return err;
624 if (!tb[NETNSA_NSID]) {
625 NL_SET_ERR_MSG(extack, "nsid is missing");
626 return -EINVAL;
627 }
628 nsid = nla_get_s32(tb[NETNSA_NSID]);
629
630 if (tb[NETNSA_PID]) {
631 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
632 nla = tb[NETNSA_PID];
633 } else if (tb[NETNSA_FD]) {
634 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
635 nla = tb[NETNSA_FD];
636 } else {
637 NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
638 return -EINVAL;
639 }
640 if (IS_ERR(peer)) {
641 NL_SET_BAD_ATTR(extack, nla);
642 NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
643 return PTR_ERR(peer);
644 }
645
646 spin_lock_bh(&net->nsid_lock);
647 if (__peernet2id(net, peer) >= 0) {
648 spin_unlock_bh(&net->nsid_lock);
649 err = -EEXIST;
650 NL_SET_BAD_ATTR(extack, nla);
651 NL_SET_ERR_MSG(extack,
652 "Peer netns already has a nsid assigned");
653 goto out;
654 }
655
656 err = alloc_netid(net, peer, nsid);
657 spin_unlock_bh(&net->nsid_lock);
658 if (err >= 0) {
659 rtnl_net_notifyid(net, RTM_NEWNSID, err);
660 err = 0;
661 } else if (err == -ENOSPC && nsid >= 0) {
662 err = -EEXIST;
663 NL_SET_BAD_ATTR(extack, tb[NETNSA_NSID]);
664 NL_SET_ERR_MSG(extack, "The specified nsid is already used");
665 }
666out:
667 put_net(peer);
668 return err;
669}
670
671static int rtnl_net_get_size(void)
672{
673 return NLMSG_ALIGN(sizeof(struct rtgenmsg))
674 + nla_total_size(sizeof(s32))
675 ;
676}
677
678static int rtnl_net_fill(struct sk_buff *skb, u32 portid, u32 seq, int flags,
679 int cmd, struct net *net, int nsid)
680{
681 struct nlmsghdr *nlh;
682 struct rtgenmsg *rth;
683
684 nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rth), flags);
685 if (!nlh)
686 return -EMSGSIZE;
687
688 rth = nlmsg_data(nlh);
689 rth->rtgen_family = AF_UNSPEC;
690
691 if (nla_put_s32(skb, NETNSA_NSID, nsid))
692 goto nla_put_failure;
693
694 nlmsg_end(skb, nlh);
695 return 0;
696
697nla_put_failure:
698 nlmsg_cancel(skb, nlh);
699 return -EMSGSIZE;
700}
701
702static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh,
703 struct netlink_ext_ack *extack)
704{
705 struct net *net = sock_net(skb->sk);
706 struct nlattr *tb[NETNSA_MAX + 1];
707 struct nlattr *nla;
708 struct sk_buff *msg;
709 struct net *peer;
710 int err, id;
711
712 err = nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX,
713 rtnl_net_policy, extack);
714 if (err < 0)
715 return err;
716 if (tb[NETNSA_PID]) {
717 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
718 nla = tb[NETNSA_PID];
719 } else if (tb[NETNSA_FD]) {
720 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
721 nla = tb[NETNSA_FD];
722 } else {
723 NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
724 return -EINVAL;
725 }
726
727 if (IS_ERR(peer)) {
728 NL_SET_BAD_ATTR(extack, nla);
729 NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
730 return PTR_ERR(peer);
731 }
732
733 msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
734 if (!msg) {
735 err = -ENOMEM;
736 goto out;
737 }
738
739 id = peernet2id(net, peer);
740 err = rtnl_net_fill(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq, 0,
741 RTM_NEWNSID, net, id);
742 if (err < 0)
743 goto err_out;
744
745 err = rtnl_unicast(msg, net, NETLINK_CB(skb).portid);
746 goto out;
747
748err_out:
749 nlmsg_free(msg);
750out:
751 put_net(peer);
752 return err;
753}
754
755struct rtnl_net_dump_cb {
756 struct net *net;
757 struct sk_buff *skb;
758 struct netlink_callback *cb;
759 int idx;
760 int s_idx;
761};
762
763static int rtnl_net_dumpid_one(int id, void *peer, void *data)
764{
765 struct rtnl_net_dump_cb *net_cb = (struct rtnl_net_dump_cb *)data;
766 int ret;
767
768 if (net_cb->idx < net_cb->s_idx)
769 goto cont;
770
771 ret = rtnl_net_fill(net_cb->skb, NETLINK_CB(net_cb->cb->skb).portid,
772 net_cb->cb->nlh->nlmsg_seq, NLM_F_MULTI,
773 RTM_NEWNSID, net_cb->net, id);
774 if (ret < 0)
775 return ret;
776
777cont:
778 net_cb->idx++;
779 return 0;
780}
781
782static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb)
783{
784 struct net *net = sock_net(skb->sk);
785 struct rtnl_net_dump_cb net_cb = {
786 .net = net,
787 .skb = skb,
788 .cb = cb,
789 .idx = 0,
790 .s_idx = cb->args[0],
791 };
792
793 spin_lock_bh(&net->nsid_lock);
794 idr_for_each(&net->netns_ids, rtnl_net_dumpid_one, &net_cb);
795 spin_unlock_bh(&net->nsid_lock);
796
797 cb->args[0] = net_cb.idx;
798 return skb->len;
799}
800
801static void rtnl_net_notifyid(struct net *net, int cmd, int id)
802{
803 struct sk_buff *msg;
804 int err = -ENOMEM;
805
806 msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
807 if (!msg)
808 goto out;
809
810 err = rtnl_net_fill(msg, 0, 0, 0, cmd, net, id);
811 if (err < 0)
812 goto err_out;
813
814 rtnl_notify(msg, net, 0, RTNLGRP_NSID, NULL, 0);
815 return;
816
817err_out:
818 nlmsg_free(msg);
819out:
820 rtnl_set_sk_err(net, RTNLGRP_NSID, err);
821}
822
823static int __init net_ns_init(void)
824{
825 struct net_generic *ng;
826
827#ifdef CONFIG_NET_NS
828 net_cachep = kmem_cache_create("net_namespace", sizeof(struct net),
829 SMP_CACHE_BYTES,
830 SLAB_PANIC, NULL);
831
832
833 netns_wq = create_singlethread_workqueue("netns");
834 if (!netns_wq)
835 panic("Could not create netns workq");
836#endif
837
838 ng = net_alloc_generic();
839 if (!ng)
840 panic("Could not allocate generic netns");
841
842 rcu_assign_pointer(init_net.gen, ng);
843
844 mutex_lock(&net_mutex);
845 if (setup_net(&init_net, &init_user_ns))
846 panic("Could not setup the initial network namespace");
847
848 init_net_initialized = true;
849
850 rtnl_lock();
851 list_add_tail_rcu(&init_net.list, &net_namespace_list);
852 rtnl_unlock();
853
854 mutex_unlock(&net_mutex);
855
856 register_pernet_subsys(&net_ns_ops);
857
858 rtnl_register(PF_UNSPEC, RTM_NEWNSID, rtnl_net_newid, NULL, NULL);
859 rtnl_register(PF_UNSPEC, RTM_GETNSID, rtnl_net_getid, rtnl_net_dumpid,
860 NULL);
861
862 return 0;
863}
864
865pure_initcall(net_ns_init);
866
867#ifdef CONFIG_NET_NS
868static int __register_pernet_operations(struct list_head *list,
869 struct pernet_operations *ops)
870{
871 struct net *net;
872 int error;
873 LIST_HEAD(net_exit_list);
874
875 list_add_tail(&ops->list, list);
876 if (ops->init || (ops->id && ops->size)) {
877 for_each_net(net) {
878 error = ops_init(ops, net);
879 if (error)
880 goto out_undo;
881 list_add_tail(&net->exit_list, &net_exit_list);
882 }
883 }
884 return 0;
885
886out_undo:
887
888 list_del(&ops->list);
889 ops_exit_list(ops, &net_exit_list);
890 ops_free_list(ops, &net_exit_list);
891 return error;
892}
893
894static void __unregister_pernet_operations(struct pernet_operations *ops)
895{
896 struct net *net;
897 LIST_HEAD(net_exit_list);
898
899 list_del(&ops->list);
900 for_each_net(net)
901 list_add_tail(&net->exit_list, &net_exit_list);
902 ops_exit_list(ops, &net_exit_list);
903 ops_free_list(ops, &net_exit_list);
904}
905
906#else
907
908static int __register_pernet_operations(struct list_head *list,
909 struct pernet_operations *ops)
910{
911 if (!init_net_initialized) {
912 list_add_tail(&ops->list, list);
913 return 0;
914 }
915
916 return ops_init(ops, &init_net);
917}
918
919static void __unregister_pernet_operations(struct pernet_operations *ops)
920{
921 if (!init_net_initialized) {
922 list_del(&ops->list);
923 } else {
924 LIST_HEAD(net_exit_list);
925 list_add(&init_net.exit_list, &net_exit_list);
926 ops_exit_list(ops, &net_exit_list);
927 ops_free_list(ops, &net_exit_list);
928 }
929}
930
931#endif
932
933static DEFINE_IDA(net_generic_ids);
934
935static int register_pernet_operations(struct list_head *list,
936 struct pernet_operations *ops)
937{
938 int error;
939
940 if (ops->id) {
941again:
942 error = ida_get_new_above(&net_generic_ids, MIN_PERNET_OPS_ID, ops->id);
943 if (error < 0) {
944 if (error == -EAGAIN) {
945 ida_pre_get(&net_generic_ids, GFP_KERNEL);
946 goto again;
947 }
948 return error;
949 }
950 max_gen_ptrs = max(max_gen_ptrs, *ops->id + 1);
951 }
952 error = __register_pernet_operations(list, ops);
953 if (error) {
954 rcu_barrier();
955 if (ops->id)
956 ida_remove(&net_generic_ids, *ops->id);
957 }
958
959 return error;
960}
961
962static void unregister_pernet_operations(struct pernet_operations *ops)
963{
964
965 __unregister_pernet_operations(ops);
966 rcu_barrier();
967 if (ops->id)
968 ida_remove(&net_generic_ids, *ops->id);
969}
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990int register_pernet_subsys(struct pernet_operations *ops)
991{
992 int error;
993 mutex_lock(&net_mutex);
994 error = register_pernet_operations(first_device, ops);
995 mutex_unlock(&net_mutex);
996 return error;
997}
998EXPORT_SYMBOL_GPL(register_pernet_subsys);
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009void unregister_pernet_subsys(struct pernet_operations *ops)
1010{
1011 mutex_lock(&net_mutex);
1012 unregister_pernet_operations(ops);
1013 mutex_unlock(&net_mutex);
1014}
1015EXPORT_SYMBOL_GPL(unregister_pernet_subsys);
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036int register_pernet_device(struct pernet_operations *ops)
1037{
1038 int error;
1039 mutex_lock(&net_mutex);
1040 error = register_pernet_operations(&pernet_list, ops);
1041 if (!error && (first_device == &pernet_list))
1042 first_device = &ops->list;
1043 mutex_unlock(&net_mutex);
1044 return error;
1045}
1046EXPORT_SYMBOL_GPL(register_pernet_device);
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057void unregister_pernet_device(struct pernet_operations *ops)
1058{
1059 mutex_lock(&net_mutex);
1060 if (&ops->list == first_device)
1061 first_device = first_device->next;
1062 unregister_pernet_operations(ops);
1063 mutex_unlock(&net_mutex);
1064}
1065EXPORT_SYMBOL_GPL(unregister_pernet_device);
1066
1067#ifdef CONFIG_NET_NS
1068static struct ns_common *netns_get(struct task_struct *task)
1069{
1070 struct net *net = NULL;
1071 struct nsproxy *nsproxy;
1072
1073 task_lock(task);
1074 nsproxy = task->nsproxy;
1075 if (nsproxy)
1076 net = get_net(nsproxy->net_ns);
1077 task_unlock(task);
1078
1079 return net ? &net->ns : NULL;
1080}
1081
1082static inline struct net *to_net_ns(struct ns_common *ns)
1083{
1084 return container_of(ns, struct net, ns);
1085}
1086
1087static void netns_put(struct ns_common *ns)
1088{
1089 put_net(to_net_ns(ns));
1090}
1091
1092static int netns_install(struct nsproxy *nsproxy, struct ns_common *ns)
1093{
1094 struct net *net = to_net_ns(ns);
1095
1096 if (!ns_capable(net->user_ns, CAP_SYS_ADMIN) ||
1097 !ns_capable(current_user_ns(), CAP_SYS_ADMIN))
1098 return -EPERM;
1099
1100 put_net(nsproxy->net_ns);
1101 nsproxy->net_ns = get_net(net);
1102 return 0;
1103}
1104
1105static struct user_namespace *netns_owner(struct ns_common *ns)
1106{
1107 return to_net_ns(ns)->user_ns;
1108}
1109
1110const struct proc_ns_operations netns_operations = {
1111 .name = "net",
1112 .type = CLONE_NEWNET,
1113 .get = netns_get,
1114 .put = netns_put,
1115 .install = netns_install,
1116 .owner = netns_owner,
1117};
1118#endif
1119