Commit | Line | Data |
---|---|---|
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> |
f0630529 EB |
13 | #include <linux/proc_fs.h> |
14 | #include <linux/file.h> | |
bc3b2d7f | 15 | #include <linux/export.h> |
5f256bec | 16 | #include <net/net_namespace.h> |
dec827d1 | 17 | #include <net/netns/generic.h> |
5f256bec EB |
18 | |
19 | /* | |
20 | * Our network namespace constructor/destructor lists | |
21 | */ | |
22 | ||
23 | static LIST_HEAD(pernet_list); | |
24 | static struct list_head *first_device = &pernet_list; | |
25 | static DEFINE_MUTEX(net_mutex); | |
26 | ||
5f256bec | 27 | LIST_HEAD(net_namespace_list); |
b76a461f | 28 | EXPORT_SYMBOL_GPL(net_namespace_list); |
5f256bec | 29 | |
734b6541 RM |
30 | struct net init_net = { |
31 | .dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head), | |
32 | }; | |
ff4b9502 | 33 | EXPORT_SYMBOL(init_net); |
5f256bec | 34 | |
dec827d1 PE |
35 | #define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */ |
36 | ||
073862ba ED |
37 | static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS; |
38 | ||
39 | static struct net_generic *net_alloc_generic(void) | |
40 | { | |
41 | struct net_generic *ng; | |
42 | size_t generic_size = offsetof(struct net_generic, ptr[max_gen_ptrs]); | |
43 | ||
44 | ng = kzalloc(generic_size, GFP_KERNEL); | |
45 | if (ng) | |
46 | ng->len = max_gen_ptrs; | |
47 | ||
48 | return ng; | |
49 | } | |
50 | ||
05fceb4a JP |
51 | static int net_assign_generic(struct net *net, int id, void *data) |
52 | { | |
53 | struct net_generic *ng, *old_ng; | |
54 | ||
55 | BUG_ON(!mutex_is_locked(&net_mutex)); | |
56 | BUG_ON(id == 0); | |
57 | ||
1c87733d ED |
58 | old_ng = rcu_dereference_protected(net->gen, |
59 | lockdep_is_held(&net_mutex)); | |
60 | ng = old_ng; | |
05fceb4a JP |
61 | if (old_ng->len >= id) |
62 | goto assign; | |
63 | ||
073862ba | 64 | ng = net_alloc_generic(); |
05fceb4a JP |
65 | if (ng == NULL) |
66 | return -ENOMEM; | |
67 | ||
68 | /* | |
69 | * Some synchronisation notes: | |
70 | * | |
71 | * The net_generic explores the net->gen array inside rcu | |
72 | * read section. Besides once set the net->gen->ptr[x] | |
73 | * pointer never changes (see rules in netns/generic.h). | |
74 | * | |
75 | * That said, we simply duplicate this array and schedule | |
76 | * the old copy for kfree after a grace period. | |
77 | */ | |
78 | ||
05fceb4a JP |
79 | memcpy(&ng->ptr, &old_ng->ptr, old_ng->len * sizeof(void*)); |
80 | ||
81 | rcu_assign_pointer(net->gen, ng); | |
04d4dfed | 82 | kfree_rcu(old_ng, rcu); |
05fceb4a JP |
83 | assign: |
84 | ng->ptr[id - 1] = data; | |
85 | return 0; | |
86 | } | |
87 | ||
f875bae0 EB |
88 | static int ops_init(const struct pernet_operations *ops, struct net *net) |
89 | { | |
b922934d JA |
90 | int err = -ENOMEM; |
91 | void *data = NULL; | |
92 | ||
f875bae0 | 93 | if (ops->id && ops->size) { |
b922934d | 94 | data = kzalloc(ops->size, GFP_KERNEL); |
f875bae0 | 95 | if (!data) |
b922934d | 96 | goto out; |
f875bae0 EB |
97 | |
98 | err = net_assign_generic(net, *ops->id, data); | |
b922934d JA |
99 | if (err) |
100 | goto cleanup; | |
f875bae0 | 101 | } |
b922934d | 102 | err = 0; |
f875bae0 | 103 | if (ops->init) |
b922934d JA |
104 | err = ops->init(net); |
105 | if (!err) | |
106 | return 0; | |
107 | ||
108 | cleanup: | |
109 | kfree(data); | |
110 | ||
111 | out: | |
112 | return err; | |
f875bae0 EB |
113 | } |
114 | ||
115 | static void ops_free(const struct pernet_operations *ops, struct net *net) | |
116 | { | |
117 | if (ops->id && ops->size) { | |
118 | int id = *ops->id; | |
119 | kfree(net_generic(net, id)); | |
120 | } | |
121 | } | |
122 | ||
72ad937a EB |
123 | static void ops_exit_list(const struct pernet_operations *ops, |
124 | struct list_head *net_exit_list) | |
125 | { | |
126 | struct net *net; | |
127 | if (ops->exit) { | |
128 | list_for_each_entry(net, net_exit_list, exit_list) | |
129 | ops->exit(net); | |
130 | } | |
72ad937a EB |
131 | if (ops->exit_batch) |
132 | ops->exit_batch(net_exit_list); | |
133 | } | |
134 | ||
135 | static void ops_free_list(const struct pernet_operations *ops, | |
136 | struct list_head *net_exit_list) | |
137 | { | |
138 | struct net *net; | |
139 | if (ops->size && ops->id) { | |
140 | list_for_each_entry(net, net_exit_list, exit_list) | |
141 | ops_free(ops, net); | |
142 | } | |
143 | } | |
144 | ||
5f256bec EB |
145 | /* |
146 | * setup_net runs the initializers for the network namespace object. | |
147 | */ | |
1a2ee93d | 148 | static __net_init int setup_net(struct net *net) |
5f256bec EB |
149 | { |
150 | /* Must be called with net_mutex held */ | |
f875bae0 | 151 | const struct pernet_operations *ops, *saved_ops; |
486a87f1 | 152 | int error = 0; |
72ad937a | 153 | LIST_HEAD(net_exit_list); |
5f256bec | 154 | |
5f256bec | 155 | atomic_set(&net->count, 1); |
a685e089 | 156 | atomic_set(&net->passive, 1); |
4e985ada | 157 | net->dev_base_seq = 1; |
486a87f1 | 158 | |
5d1e4468 | 159 | #ifdef NETNS_REFCNT_DEBUG |
5f256bec | 160 | atomic_set(&net->use_count, 0); |
5d1e4468 | 161 | #endif |
5f256bec | 162 | |
768f3591 | 163 | list_for_each_entry(ops, &pernet_list, list) { |
f875bae0 EB |
164 | error = ops_init(ops, net); |
165 | if (error < 0) | |
166 | goto out_undo; | |
5f256bec EB |
167 | } |
168 | out: | |
169 | return error; | |
768f3591 | 170 | |
5f256bec EB |
171 | out_undo: |
172 | /* Walk through the list backwards calling the exit functions | |
173 | * for the pernet modules whose init functions did not fail. | |
174 | */ | |
72ad937a | 175 | list_add(&net->exit_list, &net_exit_list); |
f875bae0 | 176 | saved_ops = ops; |
72ad937a EB |
177 | list_for_each_entry_continue_reverse(ops, &pernet_list, list) |
178 | ops_exit_list(ops, &net_exit_list); | |
179 | ||
f875bae0 EB |
180 | ops = saved_ops; |
181 | list_for_each_entry_continue_reverse(ops, &pernet_list, list) | |
72ad937a | 182 | ops_free_list(ops, &net_exit_list); |
310928d9 DL |
183 | |
184 | rcu_barrier(); | |
5f256bec EB |
185 | goto out; |
186 | } | |
187 | ||
6a1a3b9f | 188 | |
ebe47d47 CN |
189 | #ifdef CONFIG_NET_NS |
190 | static struct kmem_cache *net_cachep; | |
191 | static struct workqueue_struct *netns_wq; | |
192 | ||
486a87f1 | 193 | static struct net *net_alloc(void) |
45a19b0a | 194 | { |
486a87f1 DL |
195 | struct net *net = NULL; |
196 | struct net_generic *ng; | |
197 | ||
198 | ng = net_alloc_generic(); | |
199 | if (!ng) | |
200 | goto out; | |
201 | ||
202 | net = kmem_cache_zalloc(net_cachep, GFP_KERNEL); | |
45a19b0a | 203 | if (!net) |
486a87f1 | 204 | goto out_free; |
45a19b0a | 205 | |
486a87f1 DL |
206 | rcu_assign_pointer(net->gen, ng); |
207 | out: | |
208 | return net; | |
209 | ||
210 | out_free: | |
211 | kfree(ng); | |
212 | goto out; | |
213 | } | |
214 | ||
215 | static void net_free(struct net *net) | |
216 | { | |
5d1e4468 | 217 | #ifdef NETNS_REFCNT_DEBUG |
45a19b0a | 218 | if (unlikely(atomic_read(&net->use_count) != 0)) { |
e005d193 JP |
219 | pr_emerg("network namespace not free! Usage: %d\n", |
220 | atomic_read(&net->use_count)); | |
45a19b0a JFS |
221 | return; |
222 | } | |
5d1e4468 | 223 | #endif |
4ef079cc | 224 | kfree(net->gen); |
45a19b0a JFS |
225 | kmem_cache_free(net_cachep, net); |
226 | } | |
227 | ||
a685e089 AV |
228 | void net_drop_ns(void *p) |
229 | { | |
230 | struct net *ns = p; | |
231 | if (ns && atomic_dec_and_test(&ns->passive)) | |
232 | net_free(ns); | |
233 | } | |
234 | ||
911cb193 | 235 | struct net *copy_net_ns(unsigned long flags, struct net *old_net) |
9dd776b6 | 236 | { |
088eb2d9 AD |
237 | struct net *net; |
238 | int rv; | |
9dd776b6 | 239 | |
911cb193 RL |
240 | if (!(flags & CLONE_NEWNET)) |
241 | return get_net(old_net); | |
242 | ||
088eb2d9 AD |
243 | net = net_alloc(); |
244 | if (!net) | |
245 | return ERR_PTR(-ENOMEM); | |
9dd776b6 | 246 | mutex_lock(&net_mutex); |
088eb2d9 AD |
247 | rv = setup_net(net); |
248 | if (rv == 0) { | |
486a87f1 | 249 | rtnl_lock(); |
11a28d37 | 250 | list_add_tail_rcu(&net->list, &net_namespace_list); |
486a87f1 DL |
251 | rtnl_unlock(); |
252 | } | |
9dd776b6 | 253 | mutex_unlock(&net_mutex); |
088eb2d9 | 254 | if (rv < 0) { |
a685e089 | 255 | net_drop_ns(net); |
088eb2d9 AD |
256 | return ERR_PTR(rv); |
257 | } | |
258 | return net; | |
259 | } | |
486a87f1 | 260 | |
2b035b39 EB |
261 | static DEFINE_SPINLOCK(cleanup_list_lock); |
262 | static LIST_HEAD(cleanup_list); /* Must hold cleanup_list_lock to touch */ | |
263 | ||
6a1a3b9f PE |
264 | static void cleanup_net(struct work_struct *work) |
265 | { | |
f875bae0 | 266 | const struct pernet_operations *ops; |
2b035b39 EB |
267 | struct net *net, *tmp; |
268 | LIST_HEAD(net_kill_list); | |
72ad937a | 269 | LIST_HEAD(net_exit_list); |
6a1a3b9f | 270 | |
2b035b39 EB |
271 | /* Atomically snapshot the list of namespaces to cleanup */ |
272 | spin_lock_irq(&cleanup_list_lock); | |
273 | list_replace_init(&cleanup_list, &net_kill_list); | |
274 | spin_unlock_irq(&cleanup_list_lock); | |
6a1a3b9f PE |
275 | |
276 | mutex_lock(&net_mutex); | |
277 | ||
278 | /* Don't let anyone else find us. */ | |
279 | rtnl_lock(); | |
72ad937a | 280 | list_for_each_entry(net, &net_kill_list, cleanup_list) { |
2b035b39 | 281 | list_del_rcu(&net->list); |
72ad937a EB |
282 | list_add_tail(&net->exit_list, &net_exit_list); |
283 | } | |
6a1a3b9f PE |
284 | rtnl_unlock(); |
285 | ||
11a28d37 JB |
286 | /* |
287 | * Another CPU might be rcu-iterating the list, wait for it. | |
288 | * This needs to be before calling the exit() notifiers, so | |
289 | * the rcu_barrier() below isn't sufficient alone. | |
290 | */ | |
291 | synchronize_rcu(); | |
292 | ||
6a1a3b9f | 293 | /* Run all of the network namespace exit methods */ |
72ad937a EB |
294 | list_for_each_entry_reverse(ops, &pernet_list, list) |
295 | ops_exit_list(ops, &net_exit_list); | |
296 | ||
f875bae0 | 297 | /* Free the net generic variables */ |
72ad937a EB |
298 | list_for_each_entry_reverse(ops, &pernet_list, list) |
299 | ops_free_list(ops, &net_exit_list); | |
6a1a3b9f PE |
300 | |
301 | mutex_unlock(&net_mutex); | |
302 | ||
303 | /* Ensure there are no outstanding rcu callbacks using this | |
304 | * network namespace. | |
305 | */ | |
306 | rcu_barrier(); | |
307 | ||
308 | /* Finally it is safe to free my network namespace structure */ | |
72ad937a EB |
309 | list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) { |
310 | list_del_init(&net->exit_list); | |
a685e089 | 311 | net_drop_ns(net); |
2b035b39 | 312 | } |
6a1a3b9f | 313 | } |
2b035b39 | 314 | static DECLARE_WORK(net_cleanup_work, cleanup_net); |
6a1a3b9f PE |
315 | |
316 | void __put_net(struct net *net) | |
317 | { | |
318 | /* Cleanup the network namespace in process context */ | |
2b035b39 EB |
319 | unsigned long flags; |
320 | ||
321 | spin_lock_irqsave(&cleanup_list_lock, flags); | |
322 | list_add(&net->cleanup_list, &cleanup_list); | |
323 | spin_unlock_irqrestore(&cleanup_list_lock, flags); | |
324 | ||
325 | queue_work(netns_wq, &net_cleanup_work); | |
6a1a3b9f PE |
326 | } |
327 | EXPORT_SYMBOL_GPL(__put_net); | |
328 | ||
956c9207 SR |
329 | struct net *get_net_ns_by_fd(int fd) |
330 | { | |
331 | struct proc_inode *ei; | |
332 | struct file *file; | |
333 | struct net *net; | |
334 | ||
956c9207 | 335 | file = proc_ns_fget(fd); |
c316e6a3 AV |
336 | if (IS_ERR(file)) |
337 | return ERR_CAST(file); | |
956c9207 SR |
338 | |
339 | ei = PROC_I(file->f_dentry->d_inode); | |
c316e6a3 AV |
340 | if (ei->ns_ops == &netns_operations) |
341 | net = get_net(ei->ns); | |
342 | else | |
343 | net = ERR_PTR(-EINVAL); | |
956c9207 | 344 | |
c316e6a3 | 345 | fput(file); |
956c9207 SR |
346 | return net; |
347 | } | |
348 | ||
6a1a3b9f PE |
349 | #else |
350 | struct net *copy_net_ns(unsigned long flags, struct net *old_net) | |
351 | { | |
352 | if (flags & CLONE_NEWNET) | |
353 | return ERR_PTR(-EINVAL); | |
354 | return old_net; | |
355 | } | |
956c9207 SR |
356 | |
357 | struct net *get_net_ns_by_fd(int fd) | |
358 | { | |
359 | return ERR_PTR(-EINVAL); | |
360 | } | |
6a1a3b9f PE |
361 | #endif |
362 | ||
30ffee84 JB |
363 | struct net *get_net_ns_by_pid(pid_t pid) |
364 | { | |
365 | struct task_struct *tsk; | |
366 | struct net *net; | |
367 | ||
368 | /* Lookup the network namespace */ | |
369 | net = ERR_PTR(-ESRCH); | |
370 | rcu_read_lock(); | |
371 | tsk = find_task_by_vpid(pid); | |
372 | if (tsk) { | |
373 | struct nsproxy *nsproxy; | |
374 | nsproxy = task_nsproxy(tsk); | |
375 | if (nsproxy) | |
376 | net = get_net(nsproxy->net_ns); | |
377 | } | |
378 | rcu_read_unlock(); | |
379 | return net; | |
380 | } | |
381 | EXPORT_SYMBOL_GPL(get_net_ns_by_pid); | |
382 | ||
5f256bec EB |
383 | static int __init net_ns_init(void) |
384 | { | |
486a87f1 | 385 | struct net_generic *ng; |
5f256bec | 386 | |
d57a9212 | 387 | #ifdef CONFIG_NET_NS |
5f256bec EB |
388 | net_cachep = kmem_cache_create("net_namespace", sizeof(struct net), |
389 | SMP_CACHE_BYTES, | |
390 | SLAB_PANIC, NULL); | |
3ef1355d BT |
391 | |
392 | /* Create workqueue for cleanup */ | |
393 | netns_wq = create_singlethread_workqueue("netns"); | |
394 | if (!netns_wq) | |
395 | panic("Could not create netns workq"); | |
d57a9212 | 396 | #endif |
3ef1355d | 397 | |
486a87f1 DL |
398 | ng = net_alloc_generic(); |
399 | if (!ng) | |
400 | panic("Could not allocate generic netns"); | |
401 | ||
402 | rcu_assign_pointer(init_net.gen, ng); | |
403 | ||
5f256bec | 404 | mutex_lock(&net_mutex); |
ca0f3112 SH |
405 | if (setup_net(&init_net)) |
406 | panic("Could not setup the initial network namespace"); | |
5f256bec | 407 | |
f4618d39 | 408 | rtnl_lock(); |
11a28d37 | 409 | list_add_tail_rcu(&init_net.list, &net_namespace_list); |
f4618d39 | 410 | rtnl_unlock(); |
5f256bec EB |
411 | |
412 | mutex_unlock(&net_mutex); | |
5f256bec EB |
413 | |
414 | return 0; | |
415 | } | |
416 | ||
417 | pure_initcall(net_ns_init); | |
418 | ||
ed160e83 | 419 | #ifdef CONFIG_NET_NS |
f875bae0 EB |
420 | static int __register_pernet_operations(struct list_head *list, |
421 | struct pernet_operations *ops) | |
5f256bec | 422 | { |
72ad937a | 423 | struct net *net; |
5f256bec | 424 | int error; |
72ad937a | 425 | LIST_HEAD(net_exit_list); |
5f256bec | 426 | |
5f256bec | 427 | list_add_tail(&ops->list, list); |
f875bae0 | 428 | if (ops->init || (ops->id && ops->size)) { |
1dba323b | 429 | for_each_net(net) { |
f875bae0 | 430 | error = ops_init(ops, net); |
5f256bec EB |
431 | if (error) |
432 | goto out_undo; | |
72ad937a | 433 | list_add_tail(&net->exit_list, &net_exit_list); |
5f256bec EB |
434 | } |
435 | } | |
1dba323b | 436 | return 0; |
5f256bec EB |
437 | |
438 | out_undo: | |
439 | /* If I have an error cleanup all namespaces I initialized */ | |
440 | list_del(&ops->list); | |
72ad937a EB |
441 | ops_exit_list(ops, &net_exit_list); |
442 | ops_free_list(ops, &net_exit_list); | |
1dba323b | 443 | return error; |
5f256bec EB |
444 | } |
445 | ||
f875bae0 | 446 | static void __unregister_pernet_operations(struct pernet_operations *ops) |
5f256bec EB |
447 | { |
448 | struct net *net; | |
72ad937a | 449 | LIST_HEAD(net_exit_list); |
5f256bec EB |
450 | |
451 | list_del(&ops->list); | |
72ad937a EB |
452 | for_each_net(net) |
453 | list_add_tail(&net->exit_list, &net_exit_list); | |
454 | ops_exit_list(ops, &net_exit_list); | |
455 | ops_free_list(ops, &net_exit_list); | |
5f256bec EB |
456 | } |
457 | ||
ed160e83 DL |
458 | #else |
459 | ||
f875bae0 EB |
460 | static int __register_pernet_operations(struct list_head *list, |
461 | struct pernet_operations *ops) | |
ed160e83 | 462 | { |
b922934d | 463 | return ops_init(ops, &init_net); |
ed160e83 DL |
464 | } |
465 | ||
f875bae0 | 466 | static void __unregister_pernet_operations(struct pernet_operations *ops) |
ed160e83 | 467 | { |
72ad937a EB |
468 | LIST_HEAD(net_exit_list); |
469 | list_add(&init_net.exit_list, &net_exit_list); | |
470 | ops_exit_list(ops, &net_exit_list); | |
471 | ops_free_list(ops, &net_exit_list); | |
ed160e83 | 472 | } |
f875bae0 EB |
473 | |
474 | #endif /* CONFIG_NET_NS */ | |
ed160e83 | 475 | |
c93cf61f PE |
476 | static DEFINE_IDA(net_generic_ids); |
477 | ||
f875bae0 EB |
478 | static int register_pernet_operations(struct list_head *list, |
479 | struct pernet_operations *ops) | |
480 | { | |
481 | int error; | |
482 | ||
483 | if (ops->id) { | |
484 | again: | |
485 | error = ida_get_new_above(&net_generic_ids, 1, ops->id); | |
486 | if (error < 0) { | |
487 | if (error == -EAGAIN) { | |
488 | ida_pre_get(&net_generic_ids, GFP_KERNEL); | |
489 | goto again; | |
490 | } | |
491 | return error; | |
492 | } | |
073862ba | 493 | max_gen_ptrs = max_t(unsigned int, max_gen_ptrs, *ops->id); |
f875bae0 EB |
494 | } |
495 | error = __register_pernet_operations(list, ops); | |
3a765eda EB |
496 | if (error) { |
497 | rcu_barrier(); | |
498 | if (ops->id) | |
499 | ida_remove(&net_generic_ids, *ops->id); | |
500 | } | |
f875bae0 EB |
501 | |
502 | return error; | |
503 | } | |
504 | ||
505 | static void unregister_pernet_operations(struct pernet_operations *ops) | |
506 | { | |
507 | ||
508 | __unregister_pernet_operations(ops); | |
3a765eda | 509 | rcu_barrier(); |
f875bae0 EB |
510 | if (ops->id) |
511 | ida_remove(&net_generic_ids, *ops->id); | |
512 | } | |
513 | ||
5f256bec EB |
514 | /** |
515 | * register_pernet_subsys - register a network namespace subsystem | |
516 | * @ops: pernet operations structure for the subsystem | |
517 | * | |
518 | * Register a subsystem which has init and exit functions | |
519 | * that are called when network namespaces are created and | |
520 | * destroyed respectively. | |
521 | * | |
522 | * When registered all network namespace init functions are | |
523 | * called for every existing network namespace. Allowing kernel | |
524 | * modules to have a race free view of the set of network namespaces. | |
525 | * | |
526 | * When a new network namespace is created all of the init | |
527 | * methods are called in the order in which they were registered. | |
528 | * | |
529 | * When a network namespace is destroyed all of the exit methods | |
530 | * are called in the reverse of the order with which they were | |
531 | * registered. | |
532 | */ | |
533 | int register_pernet_subsys(struct pernet_operations *ops) | |
534 | { | |
535 | int error; | |
536 | mutex_lock(&net_mutex); | |
537 | error = register_pernet_operations(first_device, ops); | |
538 | mutex_unlock(&net_mutex); | |
539 | return error; | |
540 | } | |
541 | EXPORT_SYMBOL_GPL(register_pernet_subsys); | |
542 | ||
543 | /** | |
544 | * unregister_pernet_subsys - unregister a network namespace subsystem | |
545 | * @ops: pernet operations structure to manipulate | |
546 | * | |
547 | * Remove the pernet operations structure from the list to be | |
53379e57 | 548 | * used when network namespaces are created or destroyed. In |
5f256bec EB |
549 | * addition run the exit method for all existing network |
550 | * namespaces. | |
551 | */ | |
b3c981d2 | 552 | void unregister_pernet_subsys(struct pernet_operations *ops) |
5f256bec EB |
553 | { |
554 | mutex_lock(&net_mutex); | |
b3c981d2 | 555 | unregister_pernet_operations(ops); |
5f256bec EB |
556 | mutex_unlock(&net_mutex); |
557 | } | |
558 | EXPORT_SYMBOL_GPL(unregister_pernet_subsys); | |
559 | ||
560 | /** | |
561 | * register_pernet_device - register a network namespace device | |
562 | * @ops: pernet operations structure for the subsystem | |
563 | * | |
564 | * Register a device which has init and exit functions | |
565 | * that are called when network namespaces are created and | |
566 | * destroyed respectively. | |
567 | * | |
568 | * When registered all network namespace init functions are | |
569 | * called for every existing network namespace. Allowing kernel | |
570 | * modules to have a race free view of the set of network namespaces. | |
571 | * | |
572 | * When a new network namespace is created all of the init | |
573 | * methods are called in the order in which they were registered. | |
574 | * | |
575 | * When a network namespace is destroyed all of the exit methods | |
576 | * are called in the reverse of the order with which they were | |
577 | * registered. | |
578 | */ | |
579 | int register_pernet_device(struct pernet_operations *ops) | |
580 | { | |
581 | int error; | |
582 | mutex_lock(&net_mutex); | |
583 | error = register_pernet_operations(&pernet_list, ops); | |
584 | if (!error && (first_device == &pernet_list)) | |
585 | first_device = &ops->list; | |
586 | mutex_unlock(&net_mutex); | |
587 | return error; | |
588 | } | |
589 | EXPORT_SYMBOL_GPL(register_pernet_device); | |
590 | ||
591 | /** | |
592 | * unregister_pernet_device - unregister a network namespace netdevice | |
593 | * @ops: pernet operations structure to manipulate | |
594 | * | |
595 | * Remove the pernet operations structure from the list to be | |
53379e57 | 596 | * used when network namespaces are created or destroyed. In |
5f256bec EB |
597 | * addition run the exit method for all existing network |
598 | * namespaces. | |
599 | */ | |
600 | void unregister_pernet_device(struct pernet_operations *ops) | |
601 | { | |
602 | mutex_lock(&net_mutex); | |
603 | if (&ops->list == first_device) | |
604 | first_device = first_device->next; | |
605 | unregister_pernet_operations(ops); | |
606 | mutex_unlock(&net_mutex); | |
607 | } | |
608 | EXPORT_SYMBOL_GPL(unregister_pernet_device); | |
13b6f576 EB |
609 | |
610 | #ifdef CONFIG_NET_NS | |
611 | static void *netns_get(struct task_struct *task) | |
612 | { | |
f0630529 EB |
613 | struct net *net = NULL; |
614 | struct nsproxy *nsproxy; | |
615 | ||
13b6f576 | 616 | rcu_read_lock(); |
f0630529 EB |
617 | nsproxy = task_nsproxy(task); |
618 | if (nsproxy) | |
619 | net = get_net(nsproxy->net_ns); | |
13b6f576 | 620 | rcu_read_unlock(); |
f0630529 | 621 | |
13b6f576 EB |
622 | return net; |
623 | } | |
624 | ||
625 | static void netns_put(void *ns) | |
626 | { | |
627 | put_net(ns); | |
628 | } | |
629 | ||
630 | static int netns_install(struct nsproxy *nsproxy, void *ns) | |
631 | { | |
632 | put_net(nsproxy->net_ns); | |
633 | nsproxy->net_ns = get_net(ns); | |
634 | return 0; | |
635 | } | |
636 | ||
637 | const struct proc_ns_operations netns_operations = { | |
638 | .name = "net", | |
639 | .type = CLONE_NEWNET, | |
640 | .get = netns_get, | |
641 | .put = netns_put, | |
642 | .install = netns_install, | |
643 | }; | |
644 | #endif |