Commit | Line | Data |
---|---|---|
5f256bec EB |
1 | #include <linux/workqueue.h> |
2 | #include <linux/rtnetlink.h> | |
3 | #include <linux/cache.h> | |
4 | #include <linux/slab.h> | |
5 | #include <linux/list.h> | |
6 | #include <linux/delay.h> | |
9dd776b6 | 7 | #include <linux/sched.h> |
c93cf61f | 8 | #include <linux/idr.h> |
11a28d37 | 9 | #include <linux/rculist.h> |
30ffee84 | 10 | #include <linux/nsproxy.h> |
f0630529 EB |
11 | #include <linux/proc_fs.h> |
12 | #include <linux/file.h> | |
5f256bec | 13 | #include <net/net_namespace.h> |
dec827d1 | 14 | #include <net/netns/generic.h> |
5f256bec EB |
15 | |
16 | /* | |
17 | * Our network namespace constructor/destructor lists | |
18 | */ | |
19 | ||
20 | static LIST_HEAD(pernet_list); | |
21 | static struct list_head *first_device = &pernet_list; | |
22 | static DEFINE_MUTEX(net_mutex); | |
23 | ||
5f256bec | 24 | LIST_HEAD(net_namespace_list); |
b76a461f | 25 | EXPORT_SYMBOL_GPL(net_namespace_list); |
5f256bec | 26 | |
5f256bec | 27 | struct net init_net; |
ff4b9502 | 28 | EXPORT_SYMBOL(init_net); |
5f256bec | 29 | |
dec827d1 PE |
30 | #define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */ |
31 | ||
05fceb4a JP |
32 | static int net_assign_generic(struct net *net, int id, void *data) |
33 | { | |
34 | struct net_generic *ng, *old_ng; | |
35 | ||
36 | BUG_ON(!mutex_is_locked(&net_mutex)); | |
37 | BUG_ON(id == 0); | |
38 | ||
1c87733d ED |
39 | old_ng = rcu_dereference_protected(net->gen, |
40 | lockdep_is_held(&net_mutex)); | |
41 | ng = old_ng; | |
05fceb4a JP |
42 | if (old_ng->len >= id) |
43 | goto assign; | |
44 | ||
45 | ng = kzalloc(sizeof(struct net_generic) + | |
46 | id * sizeof(void *), GFP_KERNEL); | |
47 | if (ng == NULL) | |
48 | return -ENOMEM; | |
49 | ||
50 | /* | |
51 | * Some synchronisation notes: | |
52 | * | |
53 | * The net_generic explores the net->gen array inside rcu | |
54 | * read section. Besides once set the net->gen->ptr[x] | |
55 | * pointer never changes (see rules in netns/generic.h). | |
56 | * | |
57 | * That said, we simply duplicate this array and schedule | |
58 | * the old copy for kfree after a grace period. | |
59 | */ | |
60 | ||
61 | ng->len = id; | |
62 | memcpy(&ng->ptr, &old_ng->ptr, old_ng->len * sizeof(void*)); | |
63 | ||
64 | rcu_assign_pointer(net->gen, ng); | |
04d4dfed | 65 | kfree_rcu(old_ng, rcu); |
05fceb4a JP |
66 | assign: |
67 | ng->ptr[id - 1] = data; | |
68 | return 0; | |
69 | } | |
70 | ||
f875bae0 EB |
71 | static int ops_init(const struct pernet_operations *ops, struct net *net) |
72 | { | |
73 | int err; | |
74 | if (ops->id && ops->size) { | |
75 | void *data = kzalloc(ops->size, GFP_KERNEL); | |
76 | if (!data) | |
77 | return -ENOMEM; | |
78 | ||
79 | err = net_assign_generic(net, *ops->id, data); | |
80 | if (err) { | |
81 | kfree(data); | |
82 | return err; | |
83 | } | |
84 | } | |
85 | if (ops->init) | |
86 | return ops->init(net); | |
87 | return 0; | |
88 | } | |
89 | ||
90 | static void ops_free(const struct pernet_operations *ops, struct net *net) | |
91 | { | |
92 | if (ops->id && ops->size) { | |
93 | int id = *ops->id; | |
94 | kfree(net_generic(net, id)); | |
95 | } | |
96 | } | |
97 | ||
72ad937a EB |
98 | static void ops_exit_list(const struct pernet_operations *ops, |
99 | struct list_head *net_exit_list) | |
100 | { | |
101 | struct net *net; | |
102 | if (ops->exit) { | |
103 | list_for_each_entry(net, net_exit_list, exit_list) | |
104 | ops->exit(net); | |
105 | } | |
72ad937a EB |
106 | if (ops->exit_batch) |
107 | ops->exit_batch(net_exit_list); | |
108 | } | |
109 | ||
110 | static void ops_free_list(const struct pernet_operations *ops, | |
111 | struct list_head *net_exit_list) | |
112 | { | |
113 | struct net *net; | |
114 | if (ops->size && ops->id) { | |
115 | list_for_each_entry(net, net_exit_list, exit_list) | |
116 | ops_free(ops, net); | |
117 | } | |
118 | } | |
119 | ||
5f256bec EB |
120 | /* |
121 | * setup_net runs the initializers for the network namespace object. | |
122 | */ | |
1a2ee93d | 123 | static __net_init int setup_net(struct net *net) |
5f256bec EB |
124 | { |
125 | /* Must be called with net_mutex held */ | |
f875bae0 | 126 | const struct pernet_operations *ops, *saved_ops; |
486a87f1 | 127 | int error = 0; |
72ad937a | 128 | LIST_HEAD(net_exit_list); |
5f256bec | 129 | |
5f256bec | 130 | atomic_set(&net->count, 1); |
a685e089 | 131 | atomic_set(&net->passive, 1); |
4e985ada | 132 | net->dev_base_seq = 1; |
486a87f1 | 133 | |
5d1e4468 | 134 | #ifdef NETNS_REFCNT_DEBUG |
5f256bec | 135 | atomic_set(&net->use_count, 0); |
5d1e4468 | 136 | #endif |
5f256bec | 137 | |
768f3591 | 138 | list_for_each_entry(ops, &pernet_list, list) { |
f875bae0 EB |
139 | error = ops_init(ops, net); |
140 | if (error < 0) | |
141 | goto out_undo; | |
5f256bec EB |
142 | } |
143 | out: | |
144 | return error; | |
768f3591 | 145 | |
5f256bec EB |
146 | out_undo: |
147 | /* Walk through the list backwards calling the exit functions | |
148 | * for the pernet modules whose init functions did not fail. | |
149 | */ | |
72ad937a | 150 | list_add(&net->exit_list, &net_exit_list); |
f875bae0 | 151 | saved_ops = ops; |
72ad937a EB |
152 | list_for_each_entry_continue_reverse(ops, &pernet_list, list) |
153 | ops_exit_list(ops, &net_exit_list); | |
154 | ||
f875bae0 EB |
155 | ops = saved_ops; |
156 | list_for_each_entry_continue_reverse(ops, &pernet_list, list) | |
72ad937a | 157 | ops_free_list(ops, &net_exit_list); |
310928d9 DL |
158 | |
159 | rcu_barrier(); | |
5f256bec EB |
160 | goto out; |
161 | } | |
162 | ||
486a87f1 | 163 | static struct net_generic *net_alloc_generic(void) |
6a1a3b9f | 164 | { |
486a87f1 DL |
165 | struct net_generic *ng; |
166 | size_t generic_size = sizeof(struct net_generic) + | |
167 | INITIAL_NET_GEN_PTRS * sizeof(void *); | |
168 | ||
169 | ng = kzalloc(generic_size, GFP_KERNEL); | |
170 | if (ng) | |
171 | ng->len = INITIAL_NET_GEN_PTRS; | |
172 | ||
173 | return ng; | |
6a1a3b9f PE |
174 | } |
175 | ||
ebe47d47 CN |
176 | #ifdef CONFIG_NET_NS |
177 | static struct kmem_cache *net_cachep; | |
178 | static struct workqueue_struct *netns_wq; | |
179 | ||
486a87f1 | 180 | static struct net *net_alloc(void) |
45a19b0a | 181 | { |
486a87f1 DL |
182 | struct net *net = NULL; |
183 | struct net_generic *ng; | |
184 | ||
185 | ng = net_alloc_generic(); | |
186 | if (!ng) | |
187 | goto out; | |
188 | ||
189 | net = kmem_cache_zalloc(net_cachep, GFP_KERNEL); | |
45a19b0a | 190 | if (!net) |
486a87f1 | 191 | goto out_free; |
45a19b0a | 192 | |
486a87f1 DL |
193 | rcu_assign_pointer(net->gen, ng); |
194 | out: | |
195 | return net; | |
196 | ||
197 | out_free: | |
198 | kfree(ng); | |
199 | goto out; | |
200 | } | |
201 | ||
202 | static void net_free(struct net *net) | |
203 | { | |
5d1e4468 | 204 | #ifdef NETNS_REFCNT_DEBUG |
45a19b0a JFS |
205 | if (unlikely(atomic_read(&net->use_count) != 0)) { |
206 | printk(KERN_EMERG "network namespace not free! Usage: %d\n", | |
207 | atomic_read(&net->use_count)); | |
208 | return; | |
209 | } | |
5d1e4468 | 210 | #endif |
4ef079cc | 211 | kfree(net->gen); |
45a19b0a JFS |
212 | kmem_cache_free(net_cachep, net); |
213 | } | |
214 | ||
a685e089 AV |
215 | void net_drop_ns(void *p) |
216 | { | |
217 | struct net *ns = p; | |
218 | if (ns && atomic_dec_and_test(&ns->passive)) | |
219 | net_free(ns); | |
220 | } | |
221 | ||
911cb193 | 222 | struct net *copy_net_ns(unsigned long flags, struct net *old_net) |
9dd776b6 | 223 | { |
088eb2d9 AD |
224 | struct net *net; |
225 | int rv; | |
9dd776b6 | 226 | |
911cb193 RL |
227 | if (!(flags & CLONE_NEWNET)) |
228 | return get_net(old_net); | |
229 | ||
088eb2d9 AD |
230 | net = net_alloc(); |
231 | if (!net) | |
232 | return ERR_PTR(-ENOMEM); | |
9dd776b6 | 233 | mutex_lock(&net_mutex); |
088eb2d9 AD |
234 | rv = setup_net(net); |
235 | if (rv == 0) { | |
486a87f1 | 236 | rtnl_lock(); |
11a28d37 | 237 | list_add_tail_rcu(&net->list, &net_namespace_list); |
486a87f1 DL |
238 | rtnl_unlock(); |
239 | } | |
9dd776b6 | 240 | mutex_unlock(&net_mutex); |
088eb2d9 | 241 | if (rv < 0) { |
a685e089 | 242 | net_drop_ns(net); |
088eb2d9 AD |
243 | return ERR_PTR(rv); |
244 | } | |
245 | return net; | |
246 | } | |
486a87f1 | 247 | |
2b035b39 EB |
248 | static DEFINE_SPINLOCK(cleanup_list_lock); |
249 | static LIST_HEAD(cleanup_list); /* Must hold cleanup_list_lock to touch */ | |
250 | ||
6a1a3b9f PE |
251 | static void cleanup_net(struct work_struct *work) |
252 | { | |
f875bae0 | 253 | const struct pernet_operations *ops; |
2b035b39 EB |
254 | struct net *net, *tmp; |
255 | LIST_HEAD(net_kill_list); | |
72ad937a | 256 | LIST_HEAD(net_exit_list); |
6a1a3b9f | 257 | |
2b035b39 EB |
258 | /* Atomically snapshot the list of namespaces to cleanup */ |
259 | spin_lock_irq(&cleanup_list_lock); | |
260 | list_replace_init(&cleanup_list, &net_kill_list); | |
261 | spin_unlock_irq(&cleanup_list_lock); | |
6a1a3b9f PE |
262 | |
263 | mutex_lock(&net_mutex); | |
264 | ||
265 | /* Don't let anyone else find us. */ | |
266 | rtnl_lock(); | |
72ad937a | 267 | list_for_each_entry(net, &net_kill_list, cleanup_list) { |
2b035b39 | 268 | list_del_rcu(&net->list); |
72ad937a EB |
269 | list_add_tail(&net->exit_list, &net_exit_list); |
270 | } | |
6a1a3b9f PE |
271 | rtnl_unlock(); |
272 | ||
11a28d37 JB |
273 | /* |
274 | * Another CPU might be rcu-iterating the list, wait for it. | |
275 | * This needs to be before calling the exit() notifiers, so | |
276 | * the rcu_barrier() below isn't sufficient alone. | |
277 | */ | |
278 | synchronize_rcu(); | |
279 | ||
6a1a3b9f | 280 | /* Run all of the network namespace exit methods */ |
72ad937a EB |
281 | list_for_each_entry_reverse(ops, &pernet_list, list) |
282 | ops_exit_list(ops, &net_exit_list); | |
283 | ||
f875bae0 | 284 | /* Free the net generic variables */ |
72ad937a EB |
285 | list_for_each_entry_reverse(ops, &pernet_list, list) |
286 | ops_free_list(ops, &net_exit_list); | |
6a1a3b9f PE |
287 | |
288 | mutex_unlock(&net_mutex); | |
289 | ||
290 | /* Ensure there are no outstanding rcu callbacks using this | |
291 | * network namespace. | |
292 | */ | |
293 | rcu_barrier(); | |
294 | ||
295 | /* Finally it is safe to free my network namespace structure */ | |
72ad937a EB |
296 | list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) { |
297 | list_del_init(&net->exit_list); | |
a685e089 | 298 | net_drop_ns(net); |
2b035b39 | 299 | } |
6a1a3b9f | 300 | } |
2b035b39 | 301 | static DECLARE_WORK(net_cleanup_work, cleanup_net); |
6a1a3b9f PE |
302 | |
303 | void __put_net(struct net *net) | |
304 | { | |
305 | /* Cleanup the network namespace in process context */ | |
2b035b39 EB |
306 | unsigned long flags; |
307 | ||
308 | spin_lock_irqsave(&cleanup_list_lock, flags); | |
309 | list_add(&net->cleanup_list, &cleanup_list); | |
310 | spin_unlock_irqrestore(&cleanup_list_lock, flags); | |
311 | ||
312 | queue_work(netns_wq, &net_cleanup_work); | |
6a1a3b9f PE |
313 | } |
314 | EXPORT_SYMBOL_GPL(__put_net); | |
315 | ||
956c9207 SR |
316 | struct net *get_net_ns_by_fd(int fd) |
317 | { | |
318 | struct proc_inode *ei; | |
319 | struct file *file; | |
320 | struct net *net; | |
321 | ||
956c9207 | 322 | file = proc_ns_fget(fd); |
c316e6a3 AV |
323 | if (IS_ERR(file)) |
324 | return ERR_CAST(file); | |
956c9207 SR |
325 | |
326 | ei = PROC_I(file->f_dentry->d_inode); | |
c316e6a3 AV |
327 | if (ei->ns_ops == &netns_operations) |
328 | net = get_net(ei->ns); | |
329 | else | |
330 | net = ERR_PTR(-EINVAL); | |
956c9207 | 331 | |
c316e6a3 | 332 | fput(file); |
956c9207 SR |
333 | return net; |
334 | } | |
335 | ||
6a1a3b9f PE |
336 | #else |
337 | struct net *copy_net_ns(unsigned long flags, struct net *old_net) | |
338 | { | |
339 | if (flags & CLONE_NEWNET) | |
340 | return ERR_PTR(-EINVAL); | |
341 | return old_net; | |
342 | } | |
956c9207 SR |
343 | |
344 | struct net *get_net_ns_by_fd(int fd) | |
345 | { | |
346 | return ERR_PTR(-EINVAL); | |
347 | } | |
6a1a3b9f PE |
348 | #endif |
349 | ||
30ffee84 JB |
350 | struct net *get_net_ns_by_pid(pid_t pid) |
351 | { | |
352 | struct task_struct *tsk; | |
353 | struct net *net; | |
354 | ||
355 | /* Lookup the network namespace */ | |
356 | net = ERR_PTR(-ESRCH); | |
357 | rcu_read_lock(); | |
358 | tsk = find_task_by_vpid(pid); | |
359 | if (tsk) { | |
360 | struct nsproxy *nsproxy; | |
361 | nsproxy = task_nsproxy(tsk); | |
362 | if (nsproxy) | |
363 | net = get_net(nsproxy->net_ns); | |
364 | } | |
365 | rcu_read_unlock(); | |
366 | return net; | |
367 | } | |
368 | EXPORT_SYMBOL_GPL(get_net_ns_by_pid); | |
369 | ||
5f256bec EB |
370 | static int __init net_ns_init(void) |
371 | { | |
486a87f1 | 372 | struct net_generic *ng; |
5f256bec | 373 | |
d57a9212 | 374 | #ifdef CONFIG_NET_NS |
5f256bec EB |
375 | net_cachep = kmem_cache_create("net_namespace", sizeof(struct net), |
376 | SMP_CACHE_BYTES, | |
377 | SLAB_PANIC, NULL); | |
3ef1355d BT |
378 | |
379 | /* Create workqueue for cleanup */ | |
380 | netns_wq = create_singlethread_workqueue("netns"); | |
381 | if (!netns_wq) | |
382 | panic("Could not create netns workq"); | |
d57a9212 | 383 | #endif |
3ef1355d | 384 | |
486a87f1 DL |
385 | ng = net_alloc_generic(); |
386 | if (!ng) | |
387 | panic("Could not allocate generic netns"); | |
388 | ||
389 | rcu_assign_pointer(init_net.gen, ng); | |
390 | ||
5f256bec | 391 | mutex_lock(&net_mutex); |
ca0f3112 SH |
392 | if (setup_net(&init_net)) |
393 | panic("Could not setup the initial network namespace"); | |
5f256bec | 394 | |
f4618d39 | 395 | rtnl_lock(); |
11a28d37 | 396 | list_add_tail_rcu(&init_net.list, &net_namespace_list); |
f4618d39 | 397 | rtnl_unlock(); |
5f256bec EB |
398 | |
399 | mutex_unlock(&net_mutex); | |
5f256bec EB |
400 | |
401 | return 0; | |
402 | } | |
403 | ||
404 | pure_initcall(net_ns_init); | |
405 | ||
ed160e83 | 406 | #ifdef CONFIG_NET_NS |
f875bae0 EB |
407 | static int __register_pernet_operations(struct list_head *list, |
408 | struct pernet_operations *ops) | |
5f256bec | 409 | { |
72ad937a | 410 | struct net *net; |
5f256bec | 411 | int error; |
72ad937a | 412 | LIST_HEAD(net_exit_list); |
5f256bec | 413 | |
5f256bec | 414 | list_add_tail(&ops->list, list); |
f875bae0 | 415 | if (ops->init || (ops->id && ops->size)) { |
1dba323b | 416 | for_each_net(net) { |
f875bae0 | 417 | error = ops_init(ops, net); |
5f256bec EB |
418 | if (error) |
419 | goto out_undo; | |
72ad937a | 420 | list_add_tail(&net->exit_list, &net_exit_list); |
5f256bec EB |
421 | } |
422 | } | |
1dba323b | 423 | return 0; |
5f256bec EB |
424 | |
425 | out_undo: | |
426 | /* If I have an error cleanup all namespaces I initialized */ | |
427 | list_del(&ops->list); | |
72ad937a EB |
428 | ops_exit_list(ops, &net_exit_list); |
429 | ops_free_list(ops, &net_exit_list); | |
1dba323b | 430 | return error; |
5f256bec EB |
431 | } |
432 | ||
f875bae0 | 433 | static void __unregister_pernet_operations(struct pernet_operations *ops) |
5f256bec EB |
434 | { |
435 | struct net *net; | |
72ad937a | 436 | LIST_HEAD(net_exit_list); |
5f256bec EB |
437 | |
438 | list_del(&ops->list); | |
72ad937a EB |
439 | for_each_net(net) |
440 | list_add_tail(&net->exit_list, &net_exit_list); | |
441 | ops_exit_list(ops, &net_exit_list); | |
442 | ops_free_list(ops, &net_exit_list); | |
5f256bec EB |
443 | } |
444 | ||
ed160e83 DL |
445 | #else |
446 | ||
f875bae0 EB |
447 | static int __register_pernet_operations(struct list_head *list, |
448 | struct pernet_operations *ops) | |
ed160e83 | 449 | { |
f875bae0 EB |
450 | int err = 0; |
451 | err = ops_init(ops, &init_net); | |
452 | if (err) | |
453 | ops_free(ops, &init_net); | |
454 | return err; | |
455 | ||
ed160e83 DL |
456 | } |
457 | ||
f875bae0 | 458 | static void __unregister_pernet_operations(struct pernet_operations *ops) |
ed160e83 | 459 | { |
72ad937a EB |
460 | LIST_HEAD(net_exit_list); |
461 | list_add(&init_net.exit_list, &net_exit_list); | |
462 | ops_exit_list(ops, &net_exit_list); | |
463 | ops_free_list(ops, &net_exit_list); | |
ed160e83 | 464 | } |
f875bae0 EB |
465 | |
466 | #endif /* CONFIG_NET_NS */ | |
ed160e83 | 467 | |
c93cf61f PE |
468 | static DEFINE_IDA(net_generic_ids); |
469 | ||
f875bae0 EB |
470 | static int register_pernet_operations(struct list_head *list, |
471 | struct pernet_operations *ops) | |
472 | { | |
473 | int error; | |
474 | ||
475 | if (ops->id) { | |
476 | again: | |
477 | error = ida_get_new_above(&net_generic_ids, 1, ops->id); | |
478 | if (error < 0) { | |
479 | if (error == -EAGAIN) { | |
480 | ida_pre_get(&net_generic_ids, GFP_KERNEL); | |
481 | goto again; | |
482 | } | |
483 | return error; | |
484 | } | |
485 | } | |
486 | error = __register_pernet_operations(list, ops); | |
3a765eda EB |
487 | if (error) { |
488 | rcu_barrier(); | |
489 | if (ops->id) | |
490 | ida_remove(&net_generic_ids, *ops->id); | |
491 | } | |
f875bae0 EB |
492 | |
493 | return error; | |
494 | } | |
495 | ||
496 | static void unregister_pernet_operations(struct pernet_operations *ops) | |
497 | { | |
498 | ||
499 | __unregister_pernet_operations(ops); | |
3a765eda | 500 | rcu_barrier(); |
f875bae0 EB |
501 | if (ops->id) |
502 | ida_remove(&net_generic_ids, *ops->id); | |
503 | } | |
504 | ||
5f256bec EB |
505 | /** |
506 | * register_pernet_subsys - register a network namespace subsystem | |
507 | * @ops: pernet operations structure for the subsystem | |
508 | * | |
509 | * Register a subsystem which has init and exit functions | |
510 | * that are called when network namespaces are created and | |
511 | * destroyed respectively. | |
512 | * | |
513 | * When registered all network namespace init functions are | |
514 | * called for every existing network namespace. Allowing kernel | |
515 | * modules to have a race free view of the set of network namespaces. | |
516 | * | |
517 | * When a new network namespace is created all of the init | |
518 | * methods are called in the order in which they were registered. | |
519 | * | |
520 | * When a network namespace is destroyed all of the exit methods | |
521 | * are called in the reverse of the order with which they were | |
522 | * registered. | |
523 | */ | |
524 | int register_pernet_subsys(struct pernet_operations *ops) | |
525 | { | |
526 | int error; | |
527 | mutex_lock(&net_mutex); | |
528 | error = register_pernet_operations(first_device, ops); | |
529 | mutex_unlock(&net_mutex); | |
530 | return error; | |
531 | } | |
532 | EXPORT_SYMBOL_GPL(register_pernet_subsys); | |
533 | ||
534 | /** | |
535 | * unregister_pernet_subsys - unregister a network namespace subsystem | |
536 | * @ops: pernet operations structure to manipulate | |
537 | * | |
538 | * Remove the pernet operations structure from the list to be | |
53379e57 | 539 | * used when network namespaces are created or destroyed. In |
5f256bec EB |
540 | * addition run the exit method for all existing network |
541 | * namespaces. | |
542 | */ | |
b3c981d2 | 543 | void unregister_pernet_subsys(struct pernet_operations *ops) |
5f256bec EB |
544 | { |
545 | mutex_lock(&net_mutex); | |
b3c981d2 | 546 | unregister_pernet_operations(ops); |
5f256bec EB |
547 | mutex_unlock(&net_mutex); |
548 | } | |
549 | EXPORT_SYMBOL_GPL(unregister_pernet_subsys); | |
550 | ||
551 | /** | |
552 | * register_pernet_device - register a network namespace device | |
553 | * @ops: pernet operations structure for the subsystem | |
554 | * | |
555 | * Register a device which has init and exit functions | |
556 | * that are called when network namespaces are created and | |
557 | * destroyed respectively. | |
558 | * | |
559 | * When registered all network namespace init functions are | |
560 | * called for every existing network namespace. Allowing kernel | |
561 | * modules to have a race free view of the set of network namespaces. | |
562 | * | |
563 | * When a new network namespace is created all of the init | |
564 | * methods are called in the order in which they were registered. | |
565 | * | |
566 | * When a network namespace is destroyed all of the exit methods | |
567 | * are called in the reverse of the order with which they were | |
568 | * registered. | |
569 | */ | |
570 | int register_pernet_device(struct pernet_operations *ops) | |
571 | { | |
572 | int error; | |
573 | mutex_lock(&net_mutex); | |
574 | error = register_pernet_operations(&pernet_list, ops); | |
575 | if (!error && (first_device == &pernet_list)) | |
576 | first_device = &ops->list; | |
577 | mutex_unlock(&net_mutex); | |
578 | return error; | |
579 | } | |
580 | EXPORT_SYMBOL_GPL(register_pernet_device); | |
581 | ||
582 | /** | |
583 | * unregister_pernet_device - unregister a network namespace netdevice | |
584 | * @ops: pernet operations structure to manipulate | |
585 | * | |
586 | * Remove the pernet operations structure from the list to be | |
53379e57 | 587 | * used when network namespaces are created or destroyed. In |
5f256bec EB |
588 | * addition run the exit method for all existing network |
589 | * namespaces. | |
590 | */ | |
591 | void unregister_pernet_device(struct pernet_operations *ops) | |
592 | { | |
593 | mutex_lock(&net_mutex); | |
594 | if (&ops->list == first_device) | |
595 | first_device = first_device->next; | |
596 | unregister_pernet_operations(ops); | |
597 | mutex_unlock(&net_mutex); | |
598 | } | |
599 | EXPORT_SYMBOL_GPL(unregister_pernet_device); | |
13b6f576 EB |
600 | |
601 | #ifdef CONFIG_NET_NS | |
602 | static void *netns_get(struct task_struct *task) | |
603 | { | |
f0630529 EB |
604 | struct net *net = NULL; |
605 | struct nsproxy *nsproxy; | |
606 | ||
13b6f576 | 607 | rcu_read_lock(); |
f0630529 EB |
608 | nsproxy = task_nsproxy(task); |
609 | if (nsproxy) | |
610 | net = get_net(nsproxy->net_ns); | |
13b6f576 | 611 | rcu_read_unlock(); |
f0630529 | 612 | |
13b6f576 EB |
613 | return net; |
614 | } | |
615 | ||
616 | static void netns_put(void *ns) | |
617 | { | |
618 | put_net(ns); | |
619 | } | |
620 | ||
621 | static int netns_install(struct nsproxy *nsproxy, void *ns) | |
622 | { | |
623 | put_net(nsproxy->net_ns); | |
624 | nsproxy->net_ns = get_net(ns); | |
625 | return 0; | |
626 | } | |
627 | ||
628 | const struct proc_ns_operations netns_operations = { | |
629 | .name = "net", | |
630 | .type = CLONE_NEWNET, | |
631 | .get = netns_get, | |
632 | .put = netns_put, | |
633 | .install = netns_install, | |
634 | }; | |
635 | #endif |