netns: minor cleanup in rtnl_net_getid()
[deliverable/linux.git] / net / core / net_namespace.c
CommitLineData
e005d193
JP
1#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
2
5f256bec
EB
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>
9dd776b6 9#include <linux/sched.h>
c93cf61f 10#include <linux/idr.h>
11a28d37 11#include <linux/rculist.h>
30ffee84 12#include <linux/nsproxy.h>
0bb80f24
DH
13#include <linux/fs.h>
14#include <linux/proc_ns.h>
f0630529 15#include <linux/file.h>
bc3b2d7f 16#include <linux/export.h>
038e7332 17#include <linux/user_namespace.h>
0c7aecd4
ND
18#include <linux/net_namespace.h>
19#include <linux/rtnetlink.h>
20#include <net/sock.h>
21#include <net/netlink.h>
5f256bec 22#include <net/net_namespace.h>
dec827d1 23#include <net/netns/generic.h>
5f256bec
EB
24
25/*
26 * Our network namespace constructor/destructor lists
27 */
28
29static LIST_HEAD(pernet_list);
30static struct list_head *first_device = &pernet_list;
200b916f 31DEFINE_MUTEX(net_mutex);
5f256bec 32
5f256bec 33LIST_HEAD(net_namespace_list);
b76a461f 34EXPORT_SYMBOL_GPL(net_namespace_list);
5f256bec 35
734b6541
RM
36struct net init_net = {
37 .dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head),
38};
ff4b9502 39EXPORT_SYMBOL(init_net);
5f256bec 40
dec827d1
PE
41#define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */
42
073862ba
ED
43static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS;
44
45static struct net_generic *net_alloc_generic(void)
46{
47 struct net_generic *ng;
48 size_t generic_size = offsetof(struct net_generic, ptr[max_gen_ptrs]);
49
50 ng = kzalloc(generic_size, GFP_KERNEL);
51 if (ng)
52 ng->len = max_gen_ptrs;
53
54 return ng;
55}
56
05fceb4a
JP
57static int net_assign_generic(struct net *net, int id, void *data)
58{
59 struct net_generic *ng, *old_ng;
60
61 BUG_ON(!mutex_is_locked(&net_mutex));
62 BUG_ON(id == 0);
63
1c87733d
ED
64 old_ng = rcu_dereference_protected(net->gen,
65 lockdep_is_held(&net_mutex));
66 ng = old_ng;
05fceb4a
JP
67 if (old_ng->len >= id)
68 goto assign;
69
073862ba 70 ng = net_alloc_generic();
05fceb4a
JP
71 if (ng == NULL)
72 return -ENOMEM;
73
74 /*
75 * Some synchronisation notes:
76 *
77 * The net_generic explores the net->gen array inside rcu
78 * read section. Besides once set the net->gen->ptr[x]
79 * pointer never changes (see rules in netns/generic.h).
80 *
81 * That said, we simply duplicate this array and schedule
82 * the old copy for kfree after a grace period.
83 */
84
05fceb4a
JP
85 memcpy(&ng->ptr, &old_ng->ptr, old_ng->len * sizeof(void*));
86
87 rcu_assign_pointer(net->gen, ng);
04d4dfed 88 kfree_rcu(old_ng, rcu);
05fceb4a
JP
89assign:
90 ng->ptr[id - 1] = data;
91 return 0;
92}
93
f875bae0
EB
94static int ops_init(const struct pernet_operations *ops, struct net *net)
95{
b922934d
JA
96 int err = -ENOMEM;
97 void *data = NULL;
98
f875bae0 99 if (ops->id && ops->size) {
b922934d 100 data = kzalloc(ops->size, GFP_KERNEL);
f875bae0 101 if (!data)
b922934d 102 goto out;
f875bae0
EB
103
104 err = net_assign_generic(net, *ops->id, data);
b922934d
JA
105 if (err)
106 goto cleanup;
f875bae0 107 }
b922934d 108 err = 0;
f875bae0 109 if (ops->init)
b922934d
JA
110 err = ops->init(net);
111 if (!err)
112 return 0;
113
114cleanup:
115 kfree(data);
116
117out:
118 return err;
f875bae0
EB
119}
120
121static void ops_free(const struct pernet_operations *ops, struct net *net)
122{
123 if (ops->id && ops->size) {
124 int id = *ops->id;
125 kfree(net_generic(net, id));
126 }
127}
128
72ad937a
EB
129static void ops_exit_list(const struct pernet_operations *ops,
130 struct list_head *net_exit_list)
131{
132 struct net *net;
133 if (ops->exit) {
134 list_for_each_entry(net, net_exit_list, exit_list)
135 ops->exit(net);
136 }
72ad937a
EB
137 if (ops->exit_batch)
138 ops->exit_batch(net_exit_list);
139}
140
141static void ops_free_list(const struct pernet_operations *ops,
142 struct list_head *net_exit_list)
143{
144 struct net *net;
145 if (ops->size && ops->id) {
146 list_for_each_entry(net, net_exit_list, exit_list)
147 ops_free(ops, net);
148 }
149}
150
0c7aecd4
ND
151static int alloc_netid(struct net *net, struct net *peer, int reqid)
152{
153 int min = 0, max = 0;
154
155 ASSERT_RTNL();
156
157 if (reqid >= 0) {
158 min = reqid;
159 max = reqid + 1;
160 }
161
162 return idr_alloc(&net->netns_ids, peer, min, max, GFP_KERNEL);
163}
164
165/* This function is used by idr_for_each(). If net is equal to peer, the
166 * function returns the id so that idr_for_each() stops. Because we cannot
167 * returns the id 0 (idr_for_each() will not stop), we return the magic value
168 * NET_ID_ZERO (-1) for it.
169 */
170#define NET_ID_ZERO -1
171static int net_eq_idr(int id, void *net, void *peer)
172{
173 if (net_eq(net, peer))
174 return id ? : NET_ID_ZERO;
175 return 0;
176}
177
178static int __peernet2id(struct net *net, struct net *peer, bool alloc)
179{
180 int id = idr_for_each(&net->netns_ids, net_eq_idr, peer);
181
182 ASSERT_RTNL();
183
184 /* Magic value for id 0. */
185 if (id == NET_ID_ZERO)
186 return 0;
187 if (id > 0)
188 return id;
189
190 if (alloc)
191 return alloc_netid(net, peer, -1);
192
193 return -ENOENT;
194}
195
196/* This function returns the id of a peer netns. If no id is assigned, one will
197 * be allocated and returned.
198 */
199int peernet2id(struct net *net, struct net *peer)
200{
576b7cd2
ND
201 bool alloc = atomic_read(&peer->count) == 0 ? false : true;
202 int id;
0c7aecd4 203
576b7cd2 204 id = __peernet2id(net, peer, alloc);
0c7aecd4
ND
205 return id >= 0 ? id : NETNSA_NSID_NOT_ASSIGNED;
206}
193523bf 207EXPORT_SYMBOL(peernet2id);
0c7aecd4
ND
208
209struct net *get_net_ns_by_id(struct net *net, int id)
210{
211 struct net *peer;
212
213 if (id < 0)
214 return NULL;
215
216 rcu_read_lock();
217 peer = idr_find(&net->netns_ids, id);
218 if (peer)
219 get_net(peer);
220 rcu_read_unlock();
221
222 return peer;
223}
224
5f256bec
EB
225/*
226 * setup_net runs the initializers for the network namespace object.
227 */
038e7332 228static __net_init int setup_net(struct net *net, struct user_namespace *user_ns)
5f256bec
EB
229{
230 /* Must be called with net_mutex held */
f875bae0 231 const struct pernet_operations *ops, *saved_ops;
486a87f1 232 int error = 0;
72ad937a 233 LIST_HEAD(net_exit_list);
5f256bec 234
5f256bec 235 atomic_set(&net->count, 1);
a685e089 236 atomic_set(&net->passive, 1);
4e985ada 237 net->dev_base_seq = 1;
038e7332 238 net->user_ns = user_ns;
0c7aecd4 239 idr_init(&net->netns_ids);
486a87f1 240
768f3591 241 list_for_each_entry(ops, &pernet_list, list) {
f875bae0
EB
242 error = ops_init(ops, net);
243 if (error < 0)
244 goto out_undo;
5f256bec
EB
245 }
246out:
247 return error;
768f3591 248
5f256bec
EB
249out_undo:
250 /* Walk through the list backwards calling the exit functions
251 * for the pernet modules whose init functions did not fail.
252 */
72ad937a 253 list_add(&net->exit_list, &net_exit_list);
f875bae0 254 saved_ops = ops;
72ad937a
EB
255 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
256 ops_exit_list(ops, &net_exit_list);
257
f875bae0
EB
258 ops = saved_ops;
259 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
72ad937a 260 ops_free_list(ops, &net_exit_list);
310928d9
DL
261
262 rcu_barrier();
5f256bec
EB
263 goto out;
264}
265
6a1a3b9f 266
ebe47d47
CN
267#ifdef CONFIG_NET_NS
268static struct kmem_cache *net_cachep;
269static struct workqueue_struct *netns_wq;
270
486a87f1 271static struct net *net_alloc(void)
45a19b0a 272{
486a87f1
DL
273 struct net *net = NULL;
274 struct net_generic *ng;
275
276 ng = net_alloc_generic();
277 if (!ng)
278 goto out;
279
280 net = kmem_cache_zalloc(net_cachep, GFP_KERNEL);
45a19b0a 281 if (!net)
486a87f1 282 goto out_free;
45a19b0a 283
486a87f1
DL
284 rcu_assign_pointer(net->gen, ng);
285out:
286 return net;
287
288out_free:
289 kfree(ng);
290 goto out;
291}
292
293static void net_free(struct net *net)
294{
416c51e1 295 kfree(rcu_access_pointer(net->gen));
45a19b0a
JFS
296 kmem_cache_free(net_cachep, net);
297}
298
a685e089
AV
299void net_drop_ns(void *p)
300{
301 struct net *ns = p;
302 if (ns && atomic_dec_and_test(&ns->passive))
303 net_free(ns);
304}
305
038e7332
EB
306struct net *copy_net_ns(unsigned long flags,
307 struct user_namespace *user_ns, struct net *old_net)
9dd776b6 308{
088eb2d9
AD
309 struct net *net;
310 int rv;
9dd776b6 311
911cb193
RL
312 if (!(flags & CLONE_NEWNET))
313 return get_net(old_net);
314
088eb2d9
AD
315 net = net_alloc();
316 if (!net)
317 return ERR_PTR(-ENOMEM);
038e7332
EB
318
319 get_user_ns(user_ns);
320
9dd776b6 321 mutex_lock(&net_mutex);
038e7332 322 rv = setup_net(net, user_ns);
088eb2d9 323 if (rv == 0) {
486a87f1 324 rtnl_lock();
11a28d37 325 list_add_tail_rcu(&net->list, &net_namespace_list);
486a87f1
DL
326 rtnl_unlock();
327 }
9dd776b6 328 mutex_unlock(&net_mutex);
088eb2d9 329 if (rv < 0) {
038e7332 330 put_user_ns(user_ns);
a685e089 331 net_drop_ns(net);
088eb2d9
AD
332 return ERR_PTR(rv);
333 }
334 return net;
335}
486a87f1 336
2b035b39
EB
337static DEFINE_SPINLOCK(cleanup_list_lock);
338static LIST_HEAD(cleanup_list); /* Must hold cleanup_list_lock to touch */
339
6a1a3b9f
PE
340static void cleanup_net(struct work_struct *work)
341{
f875bae0 342 const struct pernet_operations *ops;
6d458f5b 343 struct net *net, *tmp;
1818ce4d 344 struct list_head net_kill_list;
72ad937a 345 LIST_HEAD(net_exit_list);
6a1a3b9f 346
2b035b39
EB
347 /* Atomically snapshot the list of namespaces to cleanup */
348 spin_lock_irq(&cleanup_list_lock);
349 list_replace_init(&cleanup_list, &net_kill_list);
350 spin_unlock_irq(&cleanup_list_lock);
6a1a3b9f
PE
351
352 mutex_lock(&net_mutex);
353
354 /* Don't let anyone else find us. */
355 rtnl_lock();
72ad937a 356 list_for_each_entry(net, &net_kill_list, cleanup_list) {
2b035b39 357 list_del_rcu(&net->list);
72ad937a 358 list_add_tail(&net->exit_list, &net_exit_list);
6d458f5b
ND
359 for_each_net(tmp) {
360 int id = __peernet2id(tmp, net, false);
361
362 if (id >= 0)
363 idr_remove(&tmp->netns_ids, id);
364 }
365 idr_destroy(&net->netns_ids);
366
72ad937a 367 }
6a1a3b9f
PE
368 rtnl_unlock();
369
11a28d37
JB
370 /*
371 * Another CPU might be rcu-iterating the list, wait for it.
372 * This needs to be before calling the exit() notifiers, so
373 * the rcu_barrier() below isn't sufficient alone.
374 */
375 synchronize_rcu();
376
6a1a3b9f 377 /* Run all of the network namespace exit methods */
72ad937a
EB
378 list_for_each_entry_reverse(ops, &pernet_list, list)
379 ops_exit_list(ops, &net_exit_list);
380
f875bae0 381 /* Free the net generic variables */
72ad937a
EB
382 list_for_each_entry_reverse(ops, &pernet_list, list)
383 ops_free_list(ops, &net_exit_list);
6a1a3b9f
PE
384
385 mutex_unlock(&net_mutex);
386
387 /* Ensure there are no outstanding rcu callbacks using this
388 * network namespace.
389 */
390 rcu_barrier();
391
392 /* Finally it is safe to free my network namespace structure */
72ad937a
EB
393 list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
394 list_del_init(&net->exit_list);
038e7332 395 put_user_ns(net->user_ns);
a685e089 396 net_drop_ns(net);
2b035b39 397 }
6a1a3b9f 398}
2b035b39 399static DECLARE_WORK(net_cleanup_work, cleanup_net);
6a1a3b9f
PE
400
401void __put_net(struct net *net)
402{
403 /* Cleanup the network namespace in process context */
2b035b39
EB
404 unsigned long flags;
405
406 spin_lock_irqsave(&cleanup_list_lock, flags);
407 list_add(&net->cleanup_list, &cleanup_list);
408 spin_unlock_irqrestore(&cleanup_list_lock, flags);
409
410 queue_work(netns_wq, &net_cleanup_work);
6a1a3b9f
PE
411}
412EXPORT_SYMBOL_GPL(__put_net);
413
956c9207
SR
414struct net *get_net_ns_by_fd(int fd)
415{
956c9207 416 struct file *file;
33c42940 417 struct ns_common *ns;
956c9207
SR
418 struct net *net;
419
956c9207 420 file = proc_ns_fget(fd);
c316e6a3
AV
421 if (IS_ERR(file))
422 return ERR_CAST(file);
956c9207 423
f77c8014 424 ns = get_proc_ns(file_inode(file));
33c42940
AV
425 if (ns->ops == &netns_operations)
426 net = get_net(container_of(ns, struct net, ns));
c316e6a3
AV
427 else
428 net = ERR_PTR(-EINVAL);
956c9207 429
c316e6a3 430 fput(file);
956c9207
SR
431 return net;
432}
433
6a1a3b9f 434#else
956c9207
SR
435struct net *get_net_ns_by_fd(int fd)
436{
437 return ERR_PTR(-EINVAL);
438}
6a1a3b9f 439#endif
4b681c82 440EXPORT_SYMBOL_GPL(get_net_ns_by_fd);
6a1a3b9f 441
30ffee84
JB
442struct net *get_net_ns_by_pid(pid_t pid)
443{
444 struct task_struct *tsk;
445 struct net *net;
446
447 /* Lookup the network namespace */
448 net = ERR_PTR(-ESRCH);
449 rcu_read_lock();
450 tsk = find_task_by_vpid(pid);
451 if (tsk) {
452 struct nsproxy *nsproxy;
728dba3a
EB
453 task_lock(tsk);
454 nsproxy = tsk->nsproxy;
30ffee84
JB
455 if (nsproxy)
456 net = get_net(nsproxy->net_ns);
728dba3a 457 task_unlock(tsk);
30ffee84
JB
458 }
459 rcu_read_unlock();
460 return net;
461}
462EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
463
98f842e6
EB
464static __net_init int net_ns_net_init(struct net *net)
465{
33c42940
AV
466#ifdef CONFIG_NET_NS
467 net->ns.ops = &netns_operations;
468#endif
6344c433 469 return ns_alloc_inum(&net->ns);
98f842e6
EB
470}
471
472static __net_exit void net_ns_net_exit(struct net *net)
473{
6344c433 474 ns_free_inum(&net->ns);
98f842e6
EB
475}
476
477static struct pernet_operations __net_initdata net_ns_ops = {
478 .init = net_ns_net_init,
479 .exit = net_ns_net_exit,
480};
481
0c7aecd4
ND
482static struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = {
483 [NETNSA_NONE] = { .type = NLA_UNSPEC },
484 [NETNSA_NSID] = { .type = NLA_S32 },
485 [NETNSA_PID] = { .type = NLA_U32 },
486 [NETNSA_FD] = { .type = NLA_U32 },
487};
488
489static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh)
490{
491 struct net *net = sock_net(skb->sk);
492 struct nlattr *tb[NETNSA_MAX + 1];
493 struct net *peer;
494 int nsid, err;
495
496 err = nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX,
497 rtnl_net_policy);
498 if (err < 0)
499 return err;
500 if (!tb[NETNSA_NSID])
501 return -EINVAL;
502 nsid = nla_get_s32(tb[NETNSA_NSID]);
503
504 if (tb[NETNSA_PID])
505 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
506 else if (tb[NETNSA_FD])
507 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
508 else
509 return -EINVAL;
510 if (IS_ERR(peer))
511 return PTR_ERR(peer);
512
513 if (__peernet2id(net, peer, false) >= 0) {
514 err = -EEXIST;
515 goto out;
516 }
517
518 err = alloc_netid(net, peer, nsid);
519 if (err > 0)
520 err = 0;
521out:
522 put_net(peer);
523 return err;
524}
525
526static int rtnl_net_get_size(void)
527{
528 return NLMSG_ALIGN(sizeof(struct rtgenmsg))
529 + nla_total_size(sizeof(s32)) /* NETNSA_NSID */
530 ;
531}
532
533static int rtnl_net_fill(struct sk_buff *skb, u32 portid, u32 seq, int flags,
534 int cmd, struct net *net, struct net *peer)
535{
536 struct nlmsghdr *nlh;
537 struct rtgenmsg *rth;
538 int id;
539
540 ASSERT_RTNL();
541
542 nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rth), flags);
543 if (!nlh)
544 return -EMSGSIZE;
545
546 rth = nlmsg_data(nlh);
547 rth->rtgen_family = AF_UNSPEC;
548
549 id = __peernet2id(net, peer, false);
550 if (id < 0)
551 id = NETNSA_NSID_NOT_ASSIGNED;
552 if (nla_put_s32(skb, NETNSA_NSID, id))
553 goto nla_put_failure;
554
555 nlmsg_end(skb, nlh);
556 return 0;
557
558nla_put_failure:
559 nlmsg_cancel(skb, nlh);
560 return -EMSGSIZE;
561}
562
563static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh)
564{
565 struct net *net = sock_net(skb->sk);
566 struct nlattr *tb[NETNSA_MAX + 1];
567 struct sk_buff *msg;
0c7aecd4 568 struct net *peer;
b111e4e1 569 int err;
0c7aecd4
ND
570
571 err = nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX,
572 rtnl_net_policy);
573 if (err < 0)
574 return err;
575 if (tb[NETNSA_PID])
576 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
577 else if (tb[NETNSA_FD])
578 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
579 else
580 return -EINVAL;
581
582 if (IS_ERR(peer))
583 return PTR_ERR(peer);
584
585 msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
586 if (!msg) {
587 err = -ENOMEM;
588 goto out;
589 }
590
591 err = rtnl_net_fill(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq, 0,
592 RTM_GETNSID, net, peer);
593 if (err < 0)
594 goto err_out;
595
596 err = rtnl_unicast(msg, net, NETLINK_CB(skb).portid);
597 goto out;
598
599err_out:
600 nlmsg_free(msg);
601out:
602 put_net(peer);
603 return err;
604}
605
5f256bec
EB
606static int __init net_ns_init(void)
607{
486a87f1 608 struct net_generic *ng;
5f256bec 609
d57a9212 610#ifdef CONFIG_NET_NS
5f256bec
EB
611 net_cachep = kmem_cache_create("net_namespace", sizeof(struct net),
612 SMP_CACHE_BYTES,
613 SLAB_PANIC, NULL);
3ef1355d
BT
614
615 /* Create workqueue for cleanup */
616 netns_wq = create_singlethread_workqueue("netns");
617 if (!netns_wq)
618 panic("Could not create netns workq");
d57a9212 619#endif
3ef1355d 620
486a87f1
DL
621 ng = net_alloc_generic();
622 if (!ng)
623 panic("Could not allocate generic netns");
624
625 rcu_assign_pointer(init_net.gen, ng);
626
5f256bec 627 mutex_lock(&net_mutex);
038e7332 628 if (setup_net(&init_net, &init_user_ns))
ca0f3112 629 panic("Could not setup the initial network namespace");
5f256bec 630
f4618d39 631 rtnl_lock();
11a28d37 632 list_add_tail_rcu(&init_net.list, &net_namespace_list);
f4618d39 633 rtnl_unlock();
5f256bec
EB
634
635 mutex_unlock(&net_mutex);
5f256bec 636
98f842e6
EB
637 register_pernet_subsys(&net_ns_ops);
638
0c7aecd4
ND
639 rtnl_register(PF_UNSPEC, RTM_NEWNSID, rtnl_net_newid, NULL, NULL);
640 rtnl_register(PF_UNSPEC, RTM_GETNSID, rtnl_net_getid, NULL, NULL);
641
5f256bec
EB
642 return 0;
643}
644
645pure_initcall(net_ns_init);
646
ed160e83 647#ifdef CONFIG_NET_NS
f875bae0
EB
648static int __register_pernet_operations(struct list_head *list,
649 struct pernet_operations *ops)
5f256bec 650{
72ad937a 651 struct net *net;
5f256bec 652 int error;
72ad937a 653 LIST_HEAD(net_exit_list);
5f256bec 654
5f256bec 655 list_add_tail(&ops->list, list);
f875bae0 656 if (ops->init || (ops->id && ops->size)) {
1dba323b 657 for_each_net(net) {
f875bae0 658 error = ops_init(ops, net);
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659 if (error)
660 goto out_undo;
72ad937a 661 list_add_tail(&net->exit_list, &net_exit_list);
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662 }
663 }
1dba323b 664 return 0;
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665
666out_undo:
667 /* If I have an error cleanup all namespaces I initialized */
668 list_del(&ops->list);
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669 ops_exit_list(ops, &net_exit_list);
670 ops_free_list(ops, &net_exit_list);
1dba323b 671 return error;
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672}
673
f875bae0 674static void __unregister_pernet_operations(struct pernet_operations *ops)
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675{
676 struct net *net;
72ad937a 677 LIST_HEAD(net_exit_list);
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678
679 list_del(&ops->list);
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680 for_each_net(net)
681 list_add_tail(&net->exit_list, &net_exit_list);
682 ops_exit_list(ops, &net_exit_list);
683 ops_free_list(ops, &net_exit_list);
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684}
685
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686#else
687
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688static int __register_pernet_operations(struct list_head *list,
689 struct pernet_operations *ops)
ed160e83 690{
b922934d 691 return ops_init(ops, &init_net);
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692}
693
f875bae0 694static void __unregister_pernet_operations(struct pernet_operations *ops)
ed160e83 695{
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696 LIST_HEAD(net_exit_list);
697 list_add(&init_net.exit_list, &net_exit_list);
698 ops_exit_list(ops, &net_exit_list);
699 ops_free_list(ops, &net_exit_list);
ed160e83 700}
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701
702#endif /* CONFIG_NET_NS */
ed160e83 703
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704static DEFINE_IDA(net_generic_ids);
705
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706static int register_pernet_operations(struct list_head *list,
707 struct pernet_operations *ops)
708{
709 int error;
710
711 if (ops->id) {
712again:
713 error = ida_get_new_above(&net_generic_ids, 1, ops->id);
714 if (error < 0) {
715 if (error == -EAGAIN) {
716 ida_pre_get(&net_generic_ids, GFP_KERNEL);
717 goto again;
718 }
719 return error;
720 }
073862ba 721 max_gen_ptrs = max_t(unsigned int, max_gen_ptrs, *ops->id);
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722 }
723 error = __register_pernet_operations(list, ops);
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724 if (error) {
725 rcu_barrier();
726 if (ops->id)
727 ida_remove(&net_generic_ids, *ops->id);
728 }
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729
730 return error;
731}
732
733static void unregister_pernet_operations(struct pernet_operations *ops)
734{
735
736 __unregister_pernet_operations(ops);
3a765eda 737 rcu_barrier();
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738 if (ops->id)
739 ida_remove(&net_generic_ids, *ops->id);
740}
741
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742/**
743 * register_pernet_subsys - register a network namespace subsystem
744 * @ops: pernet operations structure for the subsystem
745 *
746 * Register a subsystem which has init and exit functions
747 * that are called when network namespaces are created and
748 * destroyed respectively.
749 *
750 * When registered all network namespace init functions are
751 * called for every existing network namespace. Allowing kernel
752 * modules to have a race free view of the set of network namespaces.
753 *
754 * When a new network namespace is created all of the init
755 * methods are called in the order in which they were registered.
756 *
757 * When a network namespace is destroyed all of the exit methods
758 * are called in the reverse of the order with which they were
759 * registered.
760 */
761int register_pernet_subsys(struct pernet_operations *ops)
762{
763 int error;
764 mutex_lock(&net_mutex);
765 error = register_pernet_operations(first_device, ops);
766 mutex_unlock(&net_mutex);
767 return error;
768}
769EXPORT_SYMBOL_GPL(register_pernet_subsys);
770
771/**
772 * unregister_pernet_subsys - unregister a network namespace subsystem
773 * @ops: pernet operations structure to manipulate
774 *
775 * Remove the pernet operations structure from the list to be
53379e57 776 * used when network namespaces are created or destroyed. In
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777 * addition run the exit method for all existing network
778 * namespaces.
779 */
b3c981d2 780void unregister_pernet_subsys(struct pernet_operations *ops)
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781{
782 mutex_lock(&net_mutex);
b3c981d2 783 unregister_pernet_operations(ops);
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784 mutex_unlock(&net_mutex);
785}
786EXPORT_SYMBOL_GPL(unregister_pernet_subsys);
787
788/**
789 * register_pernet_device - register a network namespace device
790 * @ops: pernet operations structure for the subsystem
791 *
792 * Register a device which has init and exit functions
793 * that are called when network namespaces are created and
794 * destroyed respectively.
795 *
796 * When registered all network namespace init functions are
797 * called for every existing network namespace. Allowing kernel
798 * modules to have a race free view of the set of network namespaces.
799 *
800 * When a new network namespace is created all of the init
801 * methods are called in the order in which they were registered.
802 *
803 * When a network namespace is destroyed all of the exit methods
804 * are called in the reverse of the order with which they were
805 * registered.
806 */
807int register_pernet_device(struct pernet_operations *ops)
808{
809 int error;
810 mutex_lock(&net_mutex);
811 error = register_pernet_operations(&pernet_list, ops);
812 if (!error && (first_device == &pernet_list))
813 first_device = &ops->list;
814 mutex_unlock(&net_mutex);
815 return error;
816}
817EXPORT_SYMBOL_GPL(register_pernet_device);
818
819/**
820 * unregister_pernet_device - unregister a network namespace netdevice
821 * @ops: pernet operations structure to manipulate
822 *
823 * Remove the pernet operations structure from the list to be
53379e57 824 * used when network namespaces are created or destroyed. In
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825 * addition run the exit method for all existing network
826 * namespaces.
827 */
828void unregister_pernet_device(struct pernet_operations *ops)
829{
830 mutex_lock(&net_mutex);
831 if (&ops->list == first_device)
832 first_device = first_device->next;
833 unregister_pernet_operations(ops);
834 mutex_unlock(&net_mutex);
835}
836EXPORT_SYMBOL_GPL(unregister_pernet_device);
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837
838#ifdef CONFIG_NET_NS
64964528 839static struct ns_common *netns_get(struct task_struct *task)
13b6f576 840{
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841 struct net *net = NULL;
842 struct nsproxy *nsproxy;
843
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844 task_lock(task);
845 nsproxy = task->nsproxy;
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846 if (nsproxy)
847 net = get_net(nsproxy->net_ns);
728dba3a 848 task_unlock(task);
f0630529 849
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850 return net ? &net->ns : NULL;
851}
852
853static inline struct net *to_net_ns(struct ns_common *ns)
854{
855 return container_of(ns, struct net, ns);
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856}
857
64964528 858static void netns_put(struct ns_common *ns)
13b6f576 859{
ff24870f 860 put_net(to_net_ns(ns));
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861}
862
64964528 863static int netns_install(struct nsproxy *nsproxy, struct ns_common *ns)
13b6f576 864{
ff24870f 865 struct net *net = to_net_ns(ns);
142e1d1d 866
5e4a0847 867 if (!ns_capable(net->user_ns, CAP_SYS_ADMIN) ||
c7b96acf 868 !ns_capable(current_user_ns(), CAP_SYS_ADMIN))
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869 return -EPERM;
870
13b6f576 871 put_net(nsproxy->net_ns);
142e1d1d 872 nsproxy->net_ns = get_net(net);
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EB
873 return 0;
874}
875
876const struct proc_ns_operations netns_operations = {
877 .name = "net",
878 .type = CLONE_NEWNET,
879 .get = netns_get,
880 .put = netns_put,
881 .install = netns_install,
882};
883#endif
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