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> | |
bc3b2d7f | 13 | #include <linux/export.h> |
5f256bec | 14 | #include <net/net_namespace.h> |
dec827d1 | 15 | #include <net/netns/generic.h> |
5f256bec EB |
16 | |
17 | /* | |
18 | * Our network namespace constructor/destructor lists | |
19 | */ | |
20 | ||
21 | static LIST_HEAD(pernet_list); | |
22 | static struct list_head *first_device = &pernet_list; | |
23 | static DEFINE_MUTEX(net_mutex); | |
24 | ||
5f256bec | 25 | LIST_HEAD(net_namespace_list); |
b76a461f | 26 | EXPORT_SYMBOL_GPL(net_namespace_list); |
5f256bec | 27 | |
5f256bec | 28 | struct net init_net; |
ff4b9502 | 29 | EXPORT_SYMBOL(init_net); |
5f256bec | 30 | |
dec827d1 PE |
31 | #define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */ |
32 | ||
05fceb4a JP |
33 | static int net_assign_generic(struct net *net, int id, void *data) |
34 | { | |
35 | struct net_generic *ng, *old_ng; | |
36 | ||
37 | BUG_ON(!mutex_is_locked(&net_mutex)); | |
38 | BUG_ON(id == 0); | |
39 | ||
1c87733d ED |
40 | old_ng = rcu_dereference_protected(net->gen, |
41 | lockdep_is_held(&net_mutex)); | |
42 | ng = old_ng; | |
05fceb4a JP |
43 | if (old_ng->len >= id) |
44 | goto assign; | |
45 | ||
46 | ng = kzalloc(sizeof(struct net_generic) + | |
47 | id * sizeof(void *), GFP_KERNEL); | |
48 | if (ng == NULL) | |
49 | return -ENOMEM; | |
50 | ||
51 | /* | |
52 | * Some synchronisation notes: | |
53 | * | |
54 | * The net_generic explores the net->gen array inside rcu | |
55 | * read section. Besides once set the net->gen->ptr[x] | |
56 | * pointer never changes (see rules in netns/generic.h). | |
57 | * | |
58 | * That said, we simply duplicate this array and schedule | |
59 | * the old copy for kfree after a grace period. | |
60 | */ | |
61 | ||
62 | ng->len = id; | |
63 | memcpy(&ng->ptr, &old_ng->ptr, old_ng->len * sizeof(void*)); | |
64 | ||
65 | rcu_assign_pointer(net->gen, ng); | |
04d4dfed | 66 | kfree_rcu(old_ng, rcu); |
05fceb4a JP |
67 | assign: |
68 | ng->ptr[id - 1] = data; | |
69 | return 0; | |
70 | } | |
71 | ||
f875bae0 EB |
72 | static int ops_init(const struct pernet_operations *ops, struct net *net) |
73 | { | |
74 | int err; | |
75 | if (ops->id && ops->size) { | |
76 | void *data = kzalloc(ops->size, GFP_KERNEL); | |
77 | if (!data) | |
78 | return -ENOMEM; | |
79 | ||
80 | err = net_assign_generic(net, *ops->id, data); | |
81 | if (err) { | |
82 | kfree(data); | |
83 | return err; | |
84 | } | |
85 | } | |
86 | if (ops->init) | |
87 | return ops->init(net); | |
88 | return 0; | |
89 | } | |
90 | ||
91 | static void ops_free(const struct pernet_operations *ops, struct net *net) | |
92 | { | |
93 | if (ops->id && ops->size) { | |
94 | int id = *ops->id; | |
95 | kfree(net_generic(net, id)); | |
96 | } | |
97 | } | |
98 | ||
72ad937a EB |
99 | static void ops_exit_list(const struct pernet_operations *ops, |
100 | struct list_head *net_exit_list) | |
101 | { | |
102 | struct net *net; | |
103 | if (ops->exit) { | |
104 | list_for_each_entry(net, net_exit_list, exit_list) | |
105 | ops->exit(net); | |
106 | } | |
72ad937a EB |
107 | if (ops->exit_batch) |
108 | ops->exit_batch(net_exit_list); | |
109 | } | |
110 | ||
111 | static void ops_free_list(const struct pernet_operations *ops, | |
112 | struct list_head *net_exit_list) | |
113 | { | |
114 | struct net *net; | |
115 | if (ops->size && ops->id) { | |
116 | list_for_each_entry(net, net_exit_list, exit_list) | |
117 | ops_free(ops, net); | |
118 | } | |
119 | } | |
120 | ||
5f256bec EB |
121 | /* |
122 | * setup_net runs the initializers for the network namespace object. | |
123 | */ | |
1a2ee93d | 124 | static __net_init int setup_net(struct net *net) |
5f256bec EB |
125 | { |
126 | /* Must be called with net_mutex held */ | |
f875bae0 | 127 | const struct pernet_operations *ops, *saved_ops; |
486a87f1 | 128 | int error = 0; |
72ad937a | 129 | LIST_HEAD(net_exit_list); |
5f256bec | 130 | |
5f256bec | 131 | atomic_set(&net->count, 1); |
a685e089 | 132 | atomic_set(&net->passive, 1); |
4e985ada | 133 | net->dev_base_seq = 1; |
486a87f1 | 134 | |
5d1e4468 | 135 | #ifdef NETNS_REFCNT_DEBUG |
5f256bec | 136 | atomic_set(&net->use_count, 0); |
5d1e4468 | 137 | #endif |
5f256bec | 138 | |
768f3591 | 139 | list_for_each_entry(ops, &pernet_list, list) { |
f875bae0 EB |
140 | error = ops_init(ops, net); |
141 | if (error < 0) | |
142 | goto out_undo; | |
5f256bec EB |
143 | } |
144 | out: | |
145 | return error; | |
768f3591 | 146 | |
5f256bec EB |
147 | out_undo: |
148 | /* Walk through the list backwards calling the exit functions | |
149 | * for the pernet modules whose init functions did not fail. | |
150 | */ | |
72ad937a | 151 | list_add(&net->exit_list, &net_exit_list); |
f875bae0 | 152 | saved_ops = ops; |
72ad937a EB |
153 | list_for_each_entry_continue_reverse(ops, &pernet_list, list) |
154 | ops_exit_list(ops, &net_exit_list); | |
155 | ||
f875bae0 EB |
156 | ops = saved_ops; |
157 | list_for_each_entry_continue_reverse(ops, &pernet_list, list) | |
72ad937a | 158 | ops_free_list(ops, &net_exit_list); |
310928d9 DL |
159 | |
160 | rcu_barrier(); | |
5f256bec EB |
161 | goto out; |
162 | } | |
163 | ||
486a87f1 | 164 | static struct net_generic *net_alloc_generic(void) |
6a1a3b9f | 165 | { |
486a87f1 DL |
166 | struct net_generic *ng; |
167 | size_t generic_size = sizeof(struct net_generic) + | |
168 | INITIAL_NET_GEN_PTRS * sizeof(void *); | |
169 | ||
170 | ng = kzalloc(generic_size, GFP_KERNEL); | |
171 | if (ng) | |
172 | ng->len = INITIAL_NET_GEN_PTRS; | |
173 | ||
174 | return ng; | |
6a1a3b9f PE |
175 | } |
176 | ||
ebe47d47 CN |
177 | #ifdef CONFIG_NET_NS |
178 | static struct kmem_cache *net_cachep; | |
179 | static struct workqueue_struct *netns_wq; | |
180 | ||
486a87f1 | 181 | static struct net *net_alloc(void) |
45a19b0a | 182 | { |
486a87f1 DL |
183 | struct net *net = NULL; |
184 | struct net_generic *ng; | |
185 | ||
186 | ng = net_alloc_generic(); | |
187 | if (!ng) | |
188 | goto out; | |
189 | ||
190 | net = kmem_cache_zalloc(net_cachep, GFP_KERNEL); | |
45a19b0a | 191 | if (!net) |
486a87f1 | 192 | goto out_free; |
45a19b0a | 193 | |
486a87f1 DL |
194 | rcu_assign_pointer(net->gen, ng); |
195 | out: | |
196 | return net; | |
197 | ||
198 | out_free: | |
199 | kfree(ng); | |
200 | goto out; | |
201 | } | |
202 | ||
203 | static void net_free(struct net *net) | |
204 | { | |
5d1e4468 | 205 | #ifdef NETNS_REFCNT_DEBUG |
45a19b0a JFS |
206 | if (unlikely(atomic_read(&net->use_count) != 0)) { |
207 | printk(KERN_EMERG "network namespace not free! Usage: %d\n", | |
208 | atomic_read(&net->use_count)); | |
209 | return; | |
210 | } | |
5d1e4468 | 211 | #endif |
4ef079cc | 212 | kfree(net->gen); |
45a19b0a JFS |
213 | kmem_cache_free(net_cachep, net); |
214 | } | |
215 | ||
a685e089 AV |
216 | void net_drop_ns(void *p) |
217 | { | |
218 | struct net *ns = p; | |
219 | if (ns && atomic_dec_and_test(&ns->passive)) | |
220 | net_free(ns); | |
221 | } | |
222 | ||
911cb193 | 223 | struct net *copy_net_ns(unsigned long flags, struct net *old_net) |
9dd776b6 | 224 | { |
088eb2d9 AD |
225 | struct net *net; |
226 | int rv; | |
9dd776b6 | 227 | |
911cb193 RL |
228 | if (!(flags & CLONE_NEWNET)) |
229 | return get_net(old_net); | |
230 | ||
088eb2d9 AD |
231 | net = net_alloc(); |
232 | if (!net) | |
233 | return ERR_PTR(-ENOMEM); | |
9dd776b6 | 234 | mutex_lock(&net_mutex); |
088eb2d9 AD |
235 | rv = setup_net(net); |
236 | if (rv == 0) { | |
486a87f1 | 237 | rtnl_lock(); |
11a28d37 | 238 | list_add_tail_rcu(&net->list, &net_namespace_list); |
486a87f1 DL |
239 | rtnl_unlock(); |
240 | } | |
9dd776b6 | 241 | mutex_unlock(&net_mutex); |
088eb2d9 | 242 | if (rv < 0) { |
a685e089 | 243 | net_drop_ns(net); |
088eb2d9 AD |
244 | return ERR_PTR(rv); |
245 | } | |
246 | return net; | |
247 | } | |
486a87f1 | 248 | |
2b035b39 EB |
249 | static DEFINE_SPINLOCK(cleanup_list_lock); |
250 | static LIST_HEAD(cleanup_list); /* Must hold cleanup_list_lock to touch */ | |
251 | ||
6a1a3b9f PE |
252 | static void cleanup_net(struct work_struct *work) |
253 | { | |
f875bae0 | 254 | const struct pernet_operations *ops; |
2b035b39 EB |
255 | struct net *net, *tmp; |
256 | LIST_HEAD(net_kill_list); | |
72ad937a | 257 | LIST_HEAD(net_exit_list); |
6a1a3b9f | 258 | |
2b035b39 EB |
259 | /* Atomically snapshot the list of namespaces to cleanup */ |
260 | spin_lock_irq(&cleanup_list_lock); | |
261 | list_replace_init(&cleanup_list, &net_kill_list); | |
262 | spin_unlock_irq(&cleanup_list_lock); | |
6a1a3b9f PE |
263 | |
264 | mutex_lock(&net_mutex); | |
265 | ||
266 | /* Don't let anyone else find us. */ | |
267 | rtnl_lock(); | |
72ad937a | 268 | list_for_each_entry(net, &net_kill_list, cleanup_list) { |
2b035b39 | 269 | list_del_rcu(&net->list); |
72ad937a EB |
270 | list_add_tail(&net->exit_list, &net_exit_list); |
271 | } | |
6a1a3b9f PE |
272 | rtnl_unlock(); |
273 | ||
11a28d37 JB |
274 | /* |
275 | * Another CPU might be rcu-iterating the list, wait for it. | |
276 | * This needs to be before calling the exit() notifiers, so | |
277 | * the rcu_barrier() below isn't sufficient alone. | |
278 | */ | |
279 | synchronize_rcu(); | |
280 | ||
6a1a3b9f | 281 | /* Run all of the network namespace exit methods */ |
72ad937a EB |
282 | list_for_each_entry_reverse(ops, &pernet_list, list) |
283 | ops_exit_list(ops, &net_exit_list); | |
284 | ||
f875bae0 | 285 | /* Free the net generic variables */ |
72ad937a EB |
286 | list_for_each_entry_reverse(ops, &pernet_list, list) |
287 | ops_free_list(ops, &net_exit_list); | |
6a1a3b9f PE |
288 | |
289 | mutex_unlock(&net_mutex); | |
290 | ||
291 | /* Ensure there are no outstanding rcu callbacks using this | |
292 | * network namespace. | |
293 | */ | |
294 | rcu_barrier(); | |
295 | ||
296 | /* Finally it is safe to free my network namespace structure */ | |
72ad937a EB |
297 | list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) { |
298 | list_del_init(&net->exit_list); | |
a685e089 | 299 | net_drop_ns(net); |
2b035b39 | 300 | } |
6a1a3b9f | 301 | } |
2b035b39 | 302 | static DECLARE_WORK(net_cleanup_work, cleanup_net); |
6a1a3b9f PE |
303 | |
304 | void __put_net(struct net *net) | |
305 | { | |
306 | /* Cleanup the network namespace in process context */ | |
2b035b39 EB |
307 | unsigned long flags; |
308 | ||
309 | spin_lock_irqsave(&cleanup_list_lock, flags); | |
310 | list_add(&net->cleanup_list, &cleanup_list); | |
311 | spin_unlock_irqrestore(&cleanup_list_lock, flags); | |
312 | ||
313 | queue_work(netns_wq, &net_cleanup_work); | |
6a1a3b9f PE |
314 | } |
315 | EXPORT_SYMBOL_GPL(__put_net); | |
316 | ||
956c9207 SR |
317 | struct net *get_net_ns_by_fd(int fd) |
318 | { | |
319 | struct proc_inode *ei; | |
320 | struct file *file; | |
321 | struct net *net; | |
322 | ||
956c9207 | 323 | file = proc_ns_fget(fd); |
c316e6a3 AV |
324 | if (IS_ERR(file)) |
325 | return ERR_CAST(file); | |
956c9207 SR |
326 | |
327 | ei = PROC_I(file->f_dentry->d_inode); | |
c316e6a3 AV |
328 | if (ei->ns_ops == &netns_operations) |
329 | net = get_net(ei->ns); | |
330 | else | |
331 | net = ERR_PTR(-EINVAL); | |
956c9207 | 332 | |
c316e6a3 | 333 | fput(file); |
956c9207 SR |
334 | return net; |
335 | } | |
336 | ||
6a1a3b9f PE |
337 | #else |
338 | struct net *copy_net_ns(unsigned long flags, struct net *old_net) | |
339 | { | |
340 | if (flags & CLONE_NEWNET) | |
341 | return ERR_PTR(-EINVAL); | |
342 | return old_net; | |
343 | } | |
956c9207 SR |
344 | |
345 | struct net *get_net_ns_by_fd(int fd) | |
346 | { | |
347 | return ERR_PTR(-EINVAL); | |
348 | } | |
6a1a3b9f PE |
349 | #endif |
350 | ||
30ffee84 JB |
351 | struct net *get_net_ns_by_pid(pid_t pid) |
352 | { | |
353 | struct task_struct *tsk; | |
354 | struct net *net; | |
355 | ||
356 | /* Lookup the network namespace */ | |
357 | net = ERR_PTR(-ESRCH); | |
358 | rcu_read_lock(); | |
359 | tsk = find_task_by_vpid(pid); | |
360 | if (tsk) { | |
361 | struct nsproxy *nsproxy; | |
362 | nsproxy = task_nsproxy(tsk); | |
363 | if (nsproxy) | |
364 | net = get_net(nsproxy->net_ns); | |
365 | } | |
366 | rcu_read_unlock(); | |
367 | return net; | |
368 | } | |
369 | EXPORT_SYMBOL_GPL(get_net_ns_by_pid); | |
370 | ||
5f256bec EB |
371 | static int __init net_ns_init(void) |
372 | { | |
486a87f1 | 373 | struct net_generic *ng; |
5f256bec | 374 | |
d57a9212 | 375 | #ifdef CONFIG_NET_NS |
5f256bec EB |
376 | net_cachep = kmem_cache_create("net_namespace", sizeof(struct net), |
377 | SMP_CACHE_BYTES, | |
378 | SLAB_PANIC, NULL); | |
3ef1355d BT |
379 | |
380 | /* Create workqueue for cleanup */ | |
381 | netns_wq = create_singlethread_workqueue("netns"); | |
382 | if (!netns_wq) | |
383 | panic("Could not create netns workq"); | |
d57a9212 | 384 | #endif |
3ef1355d | 385 | |
486a87f1 DL |
386 | ng = net_alloc_generic(); |
387 | if (!ng) | |
388 | panic("Could not allocate generic netns"); | |
389 | ||
390 | rcu_assign_pointer(init_net.gen, ng); | |
391 | ||
5f256bec | 392 | mutex_lock(&net_mutex); |
ca0f3112 SH |
393 | if (setup_net(&init_net)) |
394 | panic("Could not setup the initial network namespace"); | |
5f256bec | 395 | |
f4618d39 | 396 | rtnl_lock(); |
11a28d37 | 397 | list_add_tail_rcu(&init_net.list, &net_namespace_list); |
f4618d39 | 398 | rtnl_unlock(); |
5f256bec EB |
399 | |
400 | mutex_unlock(&net_mutex); | |
5f256bec EB |
401 | |
402 | return 0; | |
403 | } | |
404 | ||
405 | pure_initcall(net_ns_init); | |
406 | ||
ed160e83 | 407 | #ifdef CONFIG_NET_NS |
f875bae0 EB |
408 | static int __register_pernet_operations(struct list_head *list, |
409 | struct pernet_operations *ops) | |
5f256bec | 410 | { |
72ad937a | 411 | struct net *net; |
5f256bec | 412 | int error; |
72ad937a | 413 | LIST_HEAD(net_exit_list); |
5f256bec | 414 | |
5f256bec | 415 | list_add_tail(&ops->list, list); |
f875bae0 | 416 | if (ops->init || (ops->id && ops->size)) { |
1dba323b | 417 | for_each_net(net) { |
f875bae0 | 418 | error = ops_init(ops, net); |
5f256bec EB |
419 | if (error) |
420 | goto out_undo; | |
72ad937a | 421 | list_add_tail(&net->exit_list, &net_exit_list); |
5f256bec EB |
422 | } |
423 | } | |
1dba323b | 424 | return 0; |
5f256bec EB |
425 | |
426 | out_undo: | |
427 | /* If I have an error cleanup all namespaces I initialized */ | |
428 | list_del(&ops->list); | |
72ad937a EB |
429 | ops_exit_list(ops, &net_exit_list); |
430 | ops_free_list(ops, &net_exit_list); | |
1dba323b | 431 | return error; |
5f256bec EB |
432 | } |
433 | ||
f875bae0 | 434 | static void __unregister_pernet_operations(struct pernet_operations *ops) |
5f256bec EB |
435 | { |
436 | struct net *net; | |
72ad937a | 437 | LIST_HEAD(net_exit_list); |
5f256bec EB |
438 | |
439 | list_del(&ops->list); | |
72ad937a EB |
440 | for_each_net(net) |
441 | list_add_tail(&net->exit_list, &net_exit_list); | |
442 | ops_exit_list(ops, &net_exit_list); | |
443 | ops_free_list(ops, &net_exit_list); | |
5f256bec EB |
444 | } |
445 | ||
ed160e83 DL |
446 | #else |
447 | ||
f875bae0 EB |
448 | static int __register_pernet_operations(struct list_head *list, |
449 | struct pernet_operations *ops) | |
ed160e83 | 450 | { |
f875bae0 EB |
451 | int err = 0; |
452 | err = ops_init(ops, &init_net); | |
453 | if (err) | |
454 | ops_free(ops, &init_net); | |
455 | return err; | |
456 | ||
ed160e83 DL |
457 | } |
458 | ||
f875bae0 | 459 | static void __unregister_pernet_operations(struct pernet_operations *ops) |
ed160e83 | 460 | { |
72ad937a EB |
461 | LIST_HEAD(net_exit_list); |
462 | list_add(&init_net.exit_list, &net_exit_list); | |
463 | ops_exit_list(ops, &net_exit_list); | |
464 | ops_free_list(ops, &net_exit_list); | |
ed160e83 | 465 | } |
f875bae0 EB |
466 | |
467 | #endif /* CONFIG_NET_NS */ | |
ed160e83 | 468 | |
c93cf61f PE |
469 | static DEFINE_IDA(net_generic_ids); |
470 | ||
f875bae0 EB |
471 | static int register_pernet_operations(struct list_head *list, |
472 | struct pernet_operations *ops) | |
473 | { | |
474 | int error; | |
475 | ||
476 | if (ops->id) { | |
477 | again: | |
478 | error = ida_get_new_above(&net_generic_ids, 1, ops->id); | |
479 | if (error < 0) { | |
480 | if (error == -EAGAIN) { | |
481 | ida_pre_get(&net_generic_ids, GFP_KERNEL); | |
482 | goto again; | |
483 | } | |
484 | return error; | |
485 | } | |
486 | } | |
487 | error = __register_pernet_operations(list, ops); | |
3a765eda EB |
488 | if (error) { |
489 | rcu_barrier(); | |
490 | if (ops->id) | |
491 | ida_remove(&net_generic_ids, *ops->id); | |
492 | } | |
f875bae0 EB |
493 | |
494 | return error; | |
495 | } | |
496 | ||
497 | static void unregister_pernet_operations(struct pernet_operations *ops) | |
498 | { | |
499 | ||
500 | __unregister_pernet_operations(ops); | |
3a765eda | 501 | rcu_barrier(); |
f875bae0 EB |
502 | if (ops->id) |
503 | ida_remove(&net_generic_ids, *ops->id); | |
504 | } | |
505 | ||
5f256bec EB |
506 | /** |
507 | * register_pernet_subsys - register a network namespace subsystem | |
508 | * @ops: pernet operations structure for the subsystem | |
509 | * | |
510 | * Register a subsystem which has init and exit functions | |
511 | * that are called when network namespaces are created and | |
512 | * destroyed respectively. | |
513 | * | |
514 | * When registered all network namespace init functions are | |
515 | * called for every existing network namespace. Allowing kernel | |
516 | * modules to have a race free view of the set of network namespaces. | |
517 | * | |
518 | * When a new network namespace is created all of the init | |
519 | * methods are called in the order in which they were registered. | |
520 | * | |
521 | * When a network namespace is destroyed all of the exit methods | |
522 | * are called in the reverse of the order with which they were | |
523 | * registered. | |
524 | */ | |
525 | int register_pernet_subsys(struct pernet_operations *ops) | |
526 | { | |
527 | int error; | |
528 | mutex_lock(&net_mutex); | |
529 | error = register_pernet_operations(first_device, ops); | |
530 | mutex_unlock(&net_mutex); | |
531 | return error; | |
532 | } | |
533 | EXPORT_SYMBOL_GPL(register_pernet_subsys); | |
534 | ||
535 | /** | |
536 | * unregister_pernet_subsys - unregister a network namespace subsystem | |
537 | * @ops: pernet operations structure to manipulate | |
538 | * | |
539 | * Remove the pernet operations structure from the list to be | |
53379e57 | 540 | * used when network namespaces are created or destroyed. In |
5f256bec EB |
541 | * addition run the exit method for all existing network |
542 | * namespaces. | |
543 | */ | |
b3c981d2 | 544 | void unregister_pernet_subsys(struct pernet_operations *ops) |
5f256bec EB |
545 | { |
546 | mutex_lock(&net_mutex); | |
b3c981d2 | 547 | unregister_pernet_operations(ops); |
5f256bec EB |
548 | mutex_unlock(&net_mutex); |
549 | } | |
550 | EXPORT_SYMBOL_GPL(unregister_pernet_subsys); | |
551 | ||
552 | /** | |
553 | * register_pernet_device - register a network namespace device | |
554 | * @ops: pernet operations structure for the subsystem | |
555 | * | |
556 | * Register a device which has init and exit functions | |
557 | * that are called when network namespaces are created and | |
558 | * destroyed respectively. | |
559 | * | |
560 | * When registered all network namespace init functions are | |
561 | * called for every existing network namespace. Allowing kernel | |
562 | * modules to have a race free view of the set of network namespaces. | |
563 | * | |
564 | * When a new network namespace is created all of the init | |
565 | * methods are called in the order in which they were registered. | |
566 | * | |
567 | * When a network namespace is destroyed all of the exit methods | |
568 | * are called in the reverse of the order with which they were | |
569 | * registered. | |
570 | */ | |
571 | int register_pernet_device(struct pernet_operations *ops) | |
572 | { | |
573 | int error; | |
574 | mutex_lock(&net_mutex); | |
575 | error = register_pernet_operations(&pernet_list, ops); | |
576 | if (!error && (first_device == &pernet_list)) | |
577 | first_device = &ops->list; | |
578 | mutex_unlock(&net_mutex); | |
579 | return error; | |
580 | } | |
581 | EXPORT_SYMBOL_GPL(register_pernet_device); | |
582 | ||
583 | /** | |
584 | * unregister_pernet_device - unregister a network namespace netdevice | |
585 | * @ops: pernet operations structure to manipulate | |
586 | * | |
587 | * Remove the pernet operations structure from the list to be | |
53379e57 | 588 | * used when network namespaces are created or destroyed. In |
5f256bec EB |
589 | * addition run the exit method for all existing network |
590 | * namespaces. | |
591 | */ | |
592 | void unregister_pernet_device(struct pernet_operations *ops) | |
593 | { | |
594 | mutex_lock(&net_mutex); | |
595 | if (&ops->list == first_device) | |
596 | first_device = first_device->next; | |
597 | unregister_pernet_operations(ops); | |
598 | mutex_unlock(&net_mutex); | |
599 | } | |
600 | EXPORT_SYMBOL_GPL(unregister_pernet_device); | |
13b6f576 EB |
601 | |
602 | #ifdef CONFIG_NET_NS | |
603 | static void *netns_get(struct task_struct *task) | |
604 | { | |
f0630529 EB |
605 | struct net *net = NULL; |
606 | struct nsproxy *nsproxy; | |
607 | ||
13b6f576 | 608 | rcu_read_lock(); |
f0630529 EB |
609 | nsproxy = task_nsproxy(task); |
610 | if (nsproxy) | |
611 | net = get_net(nsproxy->net_ns); | |
13b6f576 | 612 | rcu_read_unlock(); |
f0630529 | 613 | |
13b6f576 EB |
614 | return net; |
615 | } | |
616 | ||
617 | static void netns_put(void *ns) | |
618 | { | |
619 | put_net(ns); | |
620 | } | |
621 | ||
622 | static int netns_install(struct nsproxy *nsproxy, void *ns) | |
623 | { | |
624 | put_net(nsproxy->net_ns); | |
625 | nsproxy->net_ns = get_net(ns); | |
626 | return 0; | |
627 | } | |
628 | ||
629 | const struct proc_ns_operations netns_operations = { | |
630 | .name = "net", | |
631 | .type = CLONE_NEWNET, | |
632 | .get = netns_get, | |
633 | .put = netns_put, | |
634 | .install = netns_install, | |
635 | }; | |
636 | #endif |