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1#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
2
3#include <linux/workqueue.h>
4#include <linux/rtnetlink.h>
5#include <linux/cache.h>
6#include <linux/slab.h>
7#include <linux/list.h>
8#include <linux/delay.h>
9#include <linux/sched.h>
10#include <linux/idr.h>
11#include <linux/rculist.h>
12#include <linux/nsproxy.h>
13#include <linux/fs.h>
14#include <linux/proc_ns.h>
15#include <linux/file.h>
16#include <linux/export.h>
17#include <linux/user_namespace.h>
18#include <net/net_namespace.h>
19#include <net/netns/generic.h>
20
21/*
22 * Our network namespace constructor/destructor lists
23 */
24
25static LIST_HEAD(pernet_list);
26static struct list_head *first_device = &pernet_list;
27DEFINE_MUTEX(net_mutex);
28
29LIST_HEAD(net_namespace_list);
30EXPORT_SYMBOL_GPL(net_namespace_list);
31
32struct net init_net = {
33 .dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head),
34};
35EXPORT_SYMBOL(init_net);
36
37#define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */
38
39static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS;
40
41static struct net_generic *net_alloc_generic(void)
42{
43 struct net_generic *ng;
44 size_t generic_size = offsetof(struct net_generic, ptr[max_gen_ptrs]);
45
46 ng = kzalloc(generic_size, GFP_KERNEL);
47 if (ng)
48 ng->len = max_gen_ptrs;
49
50 return ng;
51}
52
53static int net_assign_generic(struct net *net, int id, void *data)
54{
55 struct net_generic *ng, *old_ng;
56
57 BUG_ON(!mutex_is_locked(&net_mutex));
58 BUG_ON(id == 0);
59
60 old_ng = rcu_dereference_protected(net->gen,
61 lockdep_is_held(&net_mutex));
62 ng = old_ng;
63 if (old_ng->len >= id)
64 goto assign;
65
66 ng = net_alloc_generic();
67 if (ng == NULL)
68 return -ENOMEM;
69
70 /*
71 * Some synchronisation notes:
72 *
73 * The net_generic explores the net->gen array inside rcu
74 * read section. Besides once set the net->gen->ptr[x]
75 * pointer never changes (see rules in netns/generic.h).
76 *
77 * That said, we simply duplicate this array and schedule
78 * the old copy for kfree after a grace period.
79 */
80
81 memcpy(&ng->ptr, &old_ng->ptr, old_ng->len * sizeof(void*));
82
83 rcu_assign_pointer(net->gen, ng);
84 kfree_rcu(old_ng, rcu);
85assign:
86 ng->ptr[id - 1] = data;
87 return 0;
88}
89
90static int ops_init(const struct pernet_operations *ops, struct net *net)
91{
92 int err = -ENOMEM;
93 void *data = NULL;
94
95 if (ops->id && ops->size) {
96 data = kzalloc(ops->size, GFP_KERNEL);
97 if (!data)
98 goto out;
99
100 err = net_assign_generic(net, *ops->id, data);
101 if (err)
102 goto cleanup;
103 }
104 err = 0;
105 if (ops->init)
106 err = ops->init(net);
107 if (!err)
108 return 0;
109
110cleanup:
111 kfree(data);
112
113out:
114 return err;
115}
116
117static void ops_free(const struct pernet_operations *ops, struct net *net)
118{
119 if (ops->id && ops->size) {
120 int id = *ops->id;
121 kfree(net_generic(net, id));
122 }
123}
124
125static void ops_exit_list(const struct pernet_operations *ops,
126 struct list_head *net_exit_list)
127{
128 struct net *net;
129 if (ops->exit) {
130 list_for_each_entry(net, net_exit_list, exit_list)
131 ops->exit(net);
132 }
133 if (ops->exit_batch)
134 ops->exit_batch(net_exit_list);
135}
136
137static void ops_free_list(const struct pernet_operations *ops,
138 struct list_head *net_exit_list)
139{
140 struct net *net;
141 if (ops->size && ops->id) {
142 list_for_each_entry(net, net_exit_list, exit_list)
143 ops_free(ops, net);
144 }
145}
146
147/*
148 * setup_net runs the initializers for the network namespace object.
149 */
150static __net_init int setup_net(struct net *net, struct user_namespace *user_ns)
151{
152 /* Must be called with net_mutex held */
153 const struct pernet_operations *ops, *saved_ops;
154 int error = 0;
155 LIST_HEAD(net_exit_list);
156
157 atomic_set(&net->count, 1);
158 atomic_set(&net->passive, 1);
159 net->dev_base_seq = 1;
160 net->user_ns = user_ns;
161
162#ifdef NETNS_REFCNT_DEBUG
163 atomic_set(&net->use_count, 0);
164#endif
165
166 list_for_each_entry(ops, &pernet_list, list) {
167 error = ops_init(ops, net);
168 if (error < 0)
169 goto out_undo;
170 }
171out:
172 return error;
173
174out_undo:
175 /* Walk through the list backwards calling the exit functions
176 * for the pernet modules whose init functions did not fail.
177 */
178 list_add(&net->exit_list, &net_exit_list);
179 saved_ops = ops;
180 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
181 ops_exit_list(ops, &net_exit_list);
182
183 ops = saved_ops;
184 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
185 ops_free_list(ops, &net_exit_list);
186
187 rcu_barrier();
188 goto out;
189}
190
191
192#ifdef CONFIG_NET_NS
193static struct kmem_cache *net_cachep;
194static struct workqueue_struct *netns_wq;
195
196static struct net *net_alloc(void)
197{
198 struct net *net = NULL;
199 struct net_generic *ng;
200
201 ng = net_alloc_generic();
202 if (!ng)
203 goto out;
204
205 net = kmem_cache_zalloc(net_cachep, GFP_KERNEL);
206 if (!net)
207 goto out_free;
208
209 rcu_assign_pointer(net->gen, ng);
210out:
211 return net;
212
213out_free:
214 kfree(ng);
215 goto out;
216}
217
218static void net_free(struct net *net)
219{
220#ifdef NETNS_REFCNT_DEBUG
221 if (unlikely(atomic_read(&net->use_count) != 0)) {
222 pr_emerg("network namespace not free! Usage: %d\n",
223 atomic_read(&net->use_count));
224 return;
225 }
226#endif
227 kfree(net->gen);
228 kmem_cache_free(net_cachep, net);
229}
230
231void net_drop_ns(void *p)
232{
233 struct net *ns = p;
234 if (ns && atomic_dec_and_test(&ns->passive))
235 net_free(ns);
236}
237
238struct net *copy_net_ns(unsigned long flags,
239 struct user_namespace *user_ns, struct net *old_net)
240{
241 struct net *net;
242 int rv;
243
244 if (!(flags & CLONE_NEWNET))
245 return get_net(old_net);
246
247 net = net_alloc();
248 if (!net)
249 return ERR_PTR(-ENOMEM);
250
251 get_user_ns(user_ns);
252
253 mutex_lock(&net_mutex);
254 rv = setup_net(net, user_ns);
255 if (rv == 0) {
256 rtnl_lock();
257 list_add_tail_rcu(&net->list, &net_namespace_list);
258 rtnl_unlock();
259 }
260 mutex_unlock(&net_mutex);
261 if (rv < 0) {
262 put_user_ns(user_ns);
263 net_drop_ns(net);
264 return ERR_PTR(rv);
265 }
266 return net;
267}
268
269static DEFINE_SPINLOCK(cleanup_list_lock);
270static LIST_HEAD(cleanup_list); /* Must hold cleanup_list_lock to touch */
271
272static void cleanup_net(struct work_struct *work)
273{
274 const struct pernet_operations *ops;
275 struct net *net, *tmp;
276 LIST_HEAD(net_kill_list);
277 LIST_HEAD(net_exit_list);
278
279 /* Atomically snapshot the list of namespaces to cleanup */
280 spin_lock_irq(&cleanup_list_lock);
281 list_replace_init(&cleanup_list, &net_kill_list);
282 spin_unlock_irq(&cleanup_list_lock);
283
284 mutex_lock(&net_mutex);
285
286 /* Don't let anyone else find us. */
287 rtnl_lock();
288 list_for_each_entry(net, &net_kill_list, cleanup_list) {
289 list_del_rcu(&net->list);
290 list_add_tail(&net->exit_list, &net_exit_list);
291 }
292 rtnl_unlock();
293
294 /*
295 * Another CPU might be rcu-iterating the list, wait for it.
296 * This needs to be before calling the exit() notifiers, so
297 * the rcu_barrier() below isn't sufficient alone.
298 */
299 synchronize_rcu();
300
301 /* Run all of the network namespace exit methods */
302 list_for_each_entry_reverse(ops, &pernet_list, list)
303 ops_exit_list(ops, &net_exit_list);
304
305 /* Free the net generic variables */
306 list_for_each_entry_reverse(ops, &pernet_list, list)
307 ops_free_list(ops, &net_exit_list);
308
309 mutex_unlock(&net_mutex);
310
311 /* Ensure there are no outstanding rcu callbacks using this
312 * network namespace.
313 */
314 rcu_barrier();
315
316 /* Finally it is safe to free my network namespace structure */
317 list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
318 list_del_init(&net->exit_list);
319 put_user_ns(net->user_ns);
320 net_drop_ns(net);
321 }
322}
323static DECLARE_WORK(net_cleanup_work, cleanup_net);
324
325void __put_net(struct net *net)
326{
327 /* Cleanup the network namespace in process context */
328 unsigned long flags;
329
330 spin_lock_irqsave(&cleanup_list_lock, flags);
331 list_add(&net->cleanup_list, &cleanup_list);
332 spin_unlock_irqrestore(&cleanup_list_lock, flags);
333
334 queue_work(netns_wq, &net_cleanup_work);
335}
336EXPORT_SYMBOL_GPL(__put_net);
337
338struct net *get_net_ns_by_fd(int fd)
339{
340 struct proc_ns *ei;
341 struct file *file;
342 struct net *net;
343
344 file = proc_ns_fget(fd);
345 if (IS_ERR(file))
346 return ERR_CAST(file);
347
348 ei = get_proc_ns(file_inode(file));
349 if (ei->ns_ops == &netns_operations)
350 net = get_net(ei->ns);
351 else
352 net = ERR_PTR(-EINVAL);
353
354 fput(file);
355 return net;
356}
357
358#else
359struct net *get_net_ns_by_fd(int fd)
360{
361 return ERR_PTR(-EINVAL);
362}
363#endif
364
365struct net *get_net_ns_by_pid(pid_t pid)
366{
367 struct task_struct *tsk;
368 struct net *net;
369
370 /* Lookup the network namespace */
371 net = ERR_PTR(-ESRCH);
372 rcu_read_lock();
373 tsk = find_task_by_vpid(pid);
374 if (tsk) {
375 struct nsproxy *nsproxy;
376 nsproxy = task_nsproxy(tsk);
377 if (nsproxy)
378 net = get_net(nsproxy->net_ns);
379 }
380 rcu_read_unlock();
381 return net;
382}
383EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
384
385static __net_init int net_ns_net_init(struct net *net)
386{
387 return proc_alloc_inum(&net->proc_inum);
388}
389
390static __net_exit void net_ns_net_exit(struct net *net)
391{
392 proc_free_inum(net->proc_inum);
393}
394
395static struct pernet_operations __net_initdata net_ns_ops = {
396 .init = net_ns_net_init,
397 .exit = net_ns_net_exit,
398};
399
400static int __init net_ns_init(void)
401{
402 struct net_generic *ng;
403
404#ifdef CONFIG_NET_NS
405 net_cachep = kmem_cache_create("net_namespace", sizeof(struct net),
406 SMP_CACHE_BYTES,
407 SLAB_PANIC, NULL);
408
409 /* Create workqueue for cleanup */
410 netns_wq = create_singlethread_workqueue("netns");
411 if (!netns_wq)
412 panic("Could not create netns workq");
413#endif
414
415 ng = net_alloc_generic();
416 if (!ng)
417 panic("Could not allocate generic netns");
418
419 rcu_assign_pointer(init_net.gen, ng);
420
421 mutex_lock(&net_mutex);
422 if (setup_net(&init_net, &init_user_ns))
423 panic("Could not setup the initial network namespace");
424
425 rtnl_lock();
426 list_add_tail_rcu(&init_net.list, &net_namespace_list);
427 rtnl_unlock();
428
429 mutex_unlock(&net_mutex);
430
431 register_pernet_subsys(&net_ns_ops);
432
433 return 0;
434}
435
436pure_initcall(net_ns_init);
437
438#ifdef CONFIG_NET_NS
439static int __register_pernet_operations(struct list_head *list,
440 struct pernet_operations *ops)
441{
442 struct net *net;
443 int error;
444 LIST_HEAD(net_exit_list);
445
446 list_add_tail(&ops->list, list);
447 if (ops->init || (ops->id && ops->size)) {
448 for_each_net(net) {
449 error = ops_init(ops, net);
450 if (error)
451 goto out_undo;
452 list_add_tail(&net->exit_list, &net_exit_list);
453 }
454 }
455 return 0;
456
457out_undo:
458 /* If I have an error cleanup all namespaces I initialized */
459 list_del(&ops->list);
460 ops_exit_list(ops, &net_exit_list);
461 ops_free_list(ops, &net_exit_list);
462 return error;
463}
464
465static void __unregister_pernet_operations(struct pernet_operations *ops)
466{
467 struct net *net;
468 LIST_HEAD(net_exit_list);
469
470 list_del(&ops->list);
471 for_each_net(net)
472 list_add_tail(&net->exit_list, &net_exit_list);
473 ops_exit_list(ops, &net_exit_list);
474 ops_free_list(ops, &net_exit_list);
475}
476
477#else
478
479static int __register_pernet_operations(struct list_head *list,
480 struct pernet_operations *ops)
481{
482 return ops_init(ops, &init_net);
483}
484
485static void __unregister_pernet_operations(struct pernet_operations *ops)
486{
487 LIST_HEAD(net_exit_list);
488 list_add(&init_net.exit_list, &net_exit_list);
489 ops_exit_list(ops, &net_exit_list);
490 ops_free_list(ops, &net_exit_list);
491}
492
493#endif /* CONFIG_NET_NS */
494
495static DEFINE_IDA(net_generic_ids);
496
497static int register_pernet_operations(struct list_head *list,
498 struct pernet_operations *ops)
499{
500 int error;
501
502 if (ops->id) {
503again:
504 error = ida_get_new_above(&net_generic_ids, 1, ops->id);
505 if (error < 0) {
506 if (error == -EAGAIN) {
507 ida_pre_get(&net_generic_ids, GFP_KERNEL);
508 goto again;
509 }
510 return error;
511 }
512 max_gen_ptrs = max_t(unsigned int, max_gen_ptrs, *ops->id);
513 }
514 error = __register_pernet_operations(list, ops);
515 if (error) {
516 rcu_barrier();
517 if (ops->id)
518 ida_remove(&net_generic_ids, *ops->id);
519 }
520
521 return error;
522}
523
524static void unregister_pernet_operations(struct pernet_operations *ops)
525{
526
527 __unregister_pernet_operations(ops);
528 rcu_barrier();
529 if (ops->id)
530 ida_remove(&net_generic_ids, *ops->id);
531}
532
533/**
534 * register_pernet_subsys - register a network namespace subsystem
535 * @ops: pernet operations structure for the subsystem
536 *
537 * Register a subsystem which has init and exit functions
538 * that are called when network namespaces are created and
539 * destroyed respectively.
540 *
541 * When registered all network namespace init functions are
542 * called for every existing network namespace. Allowing kernel
543 * modules to have a race free view of the set of network namespaces.
544 *
545 * When a new network namespace is created all of the init
546 * methods are called in the order in which they were registered.
547 *
548 * When a network namespace is destroyed all of the exit methods
549 * are called in the reverse of the order with which they were
550 * registered.
551 */
552int register_pernet_subsys(struct pernet_operations *ops)
553{
554 int error;
555 mutex_lock(&net_mutex);
556 error = register_pernet_operations(first_device, ops);
557 mutex_unlock(&net_mutex);
558 return error;
559}
560EXPORT_SYMBOL_GPL(register_pernet_subsys);
561
562/**
563 * unregister_pernet_subsys - unregister a network namespace subsystem
564 * @ops: pernet operations structure to manipulate
565 *
566 * Remove the pernet operations structure from the list to be
567 * used when network namespaces are created or destroyed. In
568 * addition run the exit method for all existing network
569 * namespaces.
570 */
571void unregister_pernet_subsys(struct pernet_operations *ops)
572{
573 mutex_lock(&net_mutex);
574 unregister_pernet_operations(ops);
575 mutex_unlock(&net_mutex);
576}
577EXPORT_SYMBOL_GPL(unregister_pernet_subsys);
578
579/**
580 * register_pernet_device - register a network namespace device
581 * @ops: pernet operations structure for the subsystem
582 *
583 * Register a device which has init and exit functions
584 * that are called when network namespaces are created and
585 * destroyed respectively.
586 *
587 * When registered all network namespace init functions are
588 * called for every existing network namespace. Allowing kernel
589 * modules to have a race free view of the set of network namespaces.
590 *
591 * When a new network namespace is created all of the init
592 * methods are called in the order in which they were registered.
593 *
594 * When a network namespace is destroyed all of the exit methods
595 * are called in the reverse of the order with which they were
596 * registered.
597 */
598int register_pernet_device(struct pernet_operations *ops)
599{
600 int error;
601 mutex_lock(&net_mutex);
602 error = register_pernet_operations(&pernet_list, ops);
603 if (!error && (first_device == &pernet_list))
604 first_device = &ops->list;
605 mutex_unlock(&net_mutex);
606 return error;
607}
608EXPORT_SYMBOL_GPL(register_pernet_device);
609
610/**
611 * unregister_pernet_device - unregister a network namespace netdevice
612 * @ops: pernet operations structure to manipulate
613 *
614 * Remove the pernet operations structure from the list to be
615 * used when network namespaces are created or destroyed. In
616 * addition run the exit method for all existing network
617 * namespaces.
618 */
619void unregister_pernet_device(struct pernet_operations *ops)
620{
621 mutex_lock(&net_mutex);
622 if (&ops->list == first_device)
623 first_device = first_device->next;
624 unregister_pernet_operations(ops);
625 mutex_unlock(&net_mutex);
626}
627EXPORT_SYMBOL_GPL(unregister_pernet_device);
628
629#ifdef CONFIG_NET_NS
630static void *netns_get(struct task_struct *task)
631{
632 struct net *net = NULL;
633 struct nsproxy *nsproxy;
634
635 rcu_read_lock();
636 nsproxy = task_nsproxy(task);
637 if (nsproxy)
638 net = get_net(nsproxy->net_ns);
639 rcu_read_unlock();
640
641 return net;
642}
643
644static void netns_put(void *ns)
645{
646 put_net(ns);
647}
648
649static int netns_install(struct nsproxy *nsproxy, void *ns)
650{
651 struct net *net = ns;
652
653 if (!ns_capable(net->user_ns, CAP_SYS_ADMIN) ||
654 !ns_capable(current_user_ns(), CAP_SYS_ADMIN))
655 return -EPERM;
656
657 put_net(nsproxy->net_ns);
658 nsproxy->net_ns = get_net(net);
659 return 0;
660}
661
662static unsigned int netns_inum(void *ns)
663{
664 struct net *net = ns;
665 return net->proc_inum;
666}
667
668const struct proc_ns_operations netns_operations = {
669 .name = "net",
670 .type = CLONE_NEWNET,
671 .get = netns_get,
672 .put = netns_put,
673 .install = netns_install,
674 .inum = netns_inum,
675};
676#endif
1// SPDX-License-Identifier: GPL-2.0-only
2#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
3
4#include <linux/workqueue.h>
5#include <linux/rtnetlink.h>
6#include <linux/cache.h>
7#include <linux/slab.h>
8#include <linux/list.h>
9#include <linux/delay.h>
10#include <linux/sched.h>
11#include <linux/idr.h>
12#include <linux/rculist.h>
13#include <linux/nsproxy.h>
14#include <linux/fs.h>
15#include <linux/proc_ns.h>
16#include <linux/file.h>
17#include <linux/export.h>
18#include <linux/user_namespace.h>
19#include <linux/net_namespace.h>
20#include <linux/sched/task.h>
21#include <linux/uidgid.h>
22
23#include <net/sock.h>
24#include <net/netlink.h>
25#include <net/net_namespace.h>
26#include <net/netns/generic.h>
27
28/*
29 * Our network namespace constructor/destructor lists
30 */
31
32static LIST_HEAD(pernet_list);
33static struct list_head *first_device = &pernet_list;
34
35LIST_HEAD(net_namespace_list);
36EXPORT_SYMBOL_GPL(net_namespace_list);
37
38/* Protects net_namespace_list. Nests iside rtnl_lock() */
39DECLARE_RWSEM(net_rwsem);
40EXPORT_SYMBOL_GPL(net_rwsem);
41
42#ifdef CONFIG_KEYS
43static struct key_tag init_net_key_domain = { .usage = REFCOUNT_INIT(1) };
44#endif
45
46struct net init_net = {
47 .count = REFCOUNT_INIT(1),
48 .dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head),
49#ifdef CONFIG_KEYS
50 .key_domain = &init_net_key_domain,
51#endif
52};
53EXPORT_SYMBOL(init_net);
54
55static bool init_net_initialized;
56/*
57 * pernet_ops_rwsem: protects: pernet_list, net_generic_ids,
58 * init_net_initialized and first_device pointer.
59 * This is internal net namespace object. Please, don't use it
60 * outside.
61 */
62DECLARE_RWSEM(pernet_ops_rwsem);
63EXPORT_SYMBOL_GPL(pernet_ops_rwsem);
64
65#define MIN_PERNET_OPS_ID \
66 ((sizeof(struct net_generic) + sizeof(void *) - 1) / sizeof(void *))
67
68#define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */
69
70static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS;
71
72static struct net_generic *net_alloc_generic(void)
73{
74 struct net_generic *ng;
75 unsigned int generic_size = offsetof(struct net_generic, ptr[max_gen_ptrs]);
76
77 ng = kzalloc(generic_size, GFP_KERNEL);
78 if (ng)
79 ng->s.len = max_gen_ptrs;
80
81 return ng;
82}
83
84static int net_assign_generic(struct net *net, unsigned int id, void *data)
85{
86 struct net_generic *ng, *old_ng;
87
88 BUG_ON(id < MIN_PERNET_OPS_ID);
89
90 old_ng = rcu_dereference_protected(net->gen,
91 lockdep_is_held(&pernet_ops_rwsem));
92 if (old_ng->s.len > id) {
93 old_ng->ptr[id] = data;
94 return 0;
95 }
96
97 ng = net_alloc_generic();
98 if (ng == NULL)
99 return -ENOMEM;
100
101 /*
102 * Some synchronisation notes:
103 *
104 * The net_generic explores the net->gen array inside rcu
105 * read section. Besides once set the net->gen->ptr[x]
106 * pointer never changes (see rules in netns/generic.h).
107 *
108 * That said, we simply duplicate this array and schedule
109 * the old copy for kfree after a grace period.
110 */
111
112 memcpy(&ng->ptr[MIN_PERNET_OPS_ID], &old_ng->ptr[MIN_PERNET_OPS_ID],
113 (old_ng->s.len - MIN_PERNET_OPS_ID) * sizeof(void *));
114 ng->ptr[id] = data;
115
116 rcu_assign_pointer(net->gen, ng);
117 kfree_rcu(old_ng, s.rcu);
118 return 0;
119}
120
121static int ops_init(const struct pernet_operations *ops, struct net *net)
122{
123 int err = -ENOMEM;
124 void *data = NULL;
125
126 if (ops->id && ops->size) {
127 data = kzalloc(ops->size, GFP_KERNEL);
128 if (!data)
129 goto out;
130
131 err = net_assign_generic(net, *ops->id, data);
132 if (err)
133 goto cleanup;
134 }
135 err = 0;
136 if (ops->init)
137 err = ops->init(net);
138 if (!err)
139 return 0;
140
141cleanup:
142 kfree(data);
143
144out:
145 return err;
146}
147
148static void ops_free(const struct pernet_operations *ops, struct net *net)
149{
150 if (ops->id && ops->size) {
151 kfree(net_generic(net, *ops->id));
152 }
153}
154
155static void ops_pre_exit_list(const struct pernet_operations *ops,
156 struct list_head *net_exit_list)
157{
158 struct net *net;
159
160 if (ops->pre_exit) {
161 list_for_each_entry(net, net_exit_list, exit_list)
162 ops->pre_exit(net);
163 }
164}
165
166static void ops_exit_list(const struct pernet_operations *ops,
167 struct list_head *net_exit_list)
168{
169 struct net *net;
170 if (ops->exit) {
171 list_for_each_entry(net, net_exit_list, exit_list)
172 ops->exit(net);
173 }
174 if (ops->exit_batch)
175 ops->exit_batch(net_exit_list);
176}
177
178static void ops_free_list(const struct pernet_operations *ops,
179 struct list_head *net_exit_list)
180{
181 struct net *net;
182 if (ops->size && ops->id) {
183 list_for_each_entry(net, net_exit_list, exit_list)
184 ops_free(ops, net);
185 }
186}
187
188/* should be called with nsid_lock held */
189static int alloc_netid(struct net *net, struct net *peer, int reqid)
190{
191 int min = 0, max = 0;
192
193 if (reqid >= 0) {
194 min = reqid;
195 max = reqid + 1;
196 }
197
198 return idr_alloc(&net->netns_ids, peer, min, max, GFP_ATOMIC);
199}
200
201/* This function is used by idr_for_each(). If net is equal to peer, the
202 * function returns the id so that idr_for_each() stops. Because we cannot
203 * returns the id 0 (idr_for_each() will not stop), we return the magic value
204 * NET_ID_ZERO (-1) for it.
205 */
206#define NET_ID_ZERO -1
207static int net_eq_idr(int id, void *net, void *peer)
208{
209 if (net_eq(net, peer))
210 return id ? : NET_ID_ZERO;
211 return 0;
212}
213
214/* Should be called with nsid_lock held. If a new id is assigned, the bool alloc
215 * is set to true, thus the caller knows that the new id must be notified via
216 * rtnl.
217 */
218static int __peernet2id_alloc(struct net *net, struct net *peer, bool *alloc)
219{
220 int id = idr_for_each(&net->netns_ids, net_eq_idr, peer);
221 bool alloc_it = *alloc;
222
223 *alloc = false;
224
225 /* Magic value for id 0. */
226 if (id == NET_ID_ZERO)
227 return 0;
228 if (id > 0)
229 return id;
230
231 if (alloc_it) {
232 id = alloc_netid(net, peer, -1);
233 *alloc = true;
234 return id >= 0 ? id : NETNSA_NSID_NOT_ASSIGNED;
235 }
236
237 return NETNSA_NSID_NOT_ASSIGNED;
238}
239
240/* should be called with nsid_lock held */
241static int __peernet2id(struct net *net, struct net *peer)
242{
243 bool no = false;
244
245 return __peernet2id_alloc(net, peer, &no);
246}
247
248static void rtnl_net_notifyid(struct net *net, int cmd, int id, u32 portid,
249 struct nlmsghdr *nlh, gfp_t gfp);
250/* This function returns the id of a peer netns. If no id is assigned, one will
251 * be allocated and returned.
252 */
253int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp)
254{
255 bool alloc = false, alive = false;
256 int id;
257
258 if (refcount_read(&net->count) == 0)
259 return NETNSA_NSID_NOT_ASSIGNED;
260 spin_lock_bh(&net->nsid_lock);
261 /*
262 * When peer is obtained from RCU lists, we may race with
263 * its cleanup. Check whether it's alive, and this guarantees
264 * we never hash a peer back to net->netns_ids, after it has
265 * just been idr_remove()'d from there in cleanup_net().
266 */
267 if (maybe_get_net(peer))
268 alive = alloc = true;
269 id = __peernet2id_alloc(net, peer, &alloc);
270 spin_unlock_bh(&net->nsid_lock);
271 if (alloc && id >= 0)
272 rtnl_net_notifyid(net, RTM_NEWNSID, id, 0, NULL, gfp);
273 if (alive)
274 put_net(peer);
275 return id;
276}
277EXPORT_SYMBOL_GPL(peernet2id_alloc);
278
279/* This function returns, if assigned, the id of a peer netns. */
280int peernet2id(struct net *net, struct net *peer)
281{
282 int id;
283
284 spin_lock_bh(&net->nsid_lock);
285 id = __peernet2id(net, peer);
286 spin_unlock_bh(&net->nsid_lock);
287 return id;
288}
289EXPORT_SYMBOL(peernet2id);
290
291/* This function returns true is the peer netns has an id assigned into the
292 * current netns.
293 */
294bool peernet_has_id(struct net *net, struct net *peer)
295{
296 return peernet2id(net, peer) >= 0;
297}
298
299struct net *get_net_ns_by_id(struct net *net, int id)
300{
301 struct net *peer;
302
303 if (id < 0)
304 return NULL;
305
306 rcu_read_lock();
307 peer = idr_find(&net->netns_ids, id);
308 if (peer)
309 peer = maybe_get_net(peer);
310 rcu_read_unlock();
311
312 return peer;
313}
314
315/*
316 * setup_net runs the initializers for the network namespace object.
317 */
318static __net_init int setup_net(struct net *net, struct user_namespace *user_ns)
319{
320 /* Must be called with pernet_ops_rwsem held */
321 const struct pernet_operations *ops, *saved_ops;
322 int error = 0;
323 LIST_HEAD(net_exit_list);
324
325 refcount_set(&net->count, 1);
326 refcount_set(&net->passive, 1);
327 get_random_bytes(&net->hash_mix, sizeof(u32));
328 net->dev_base_seq = 1;
329 net->user_ns = user_ns;
330 idr_init(&net->netns_ids);
331 spin_lock_init(&net->nsid_lock);
332 mutex_init(&net->ipv4.ra_mutex);
333
334 list_for_each_entry(ops, &pernet_list, list) {
335 error = ops_init(ops, net);
336 if (error < 0)
337 goto out_undo;
338 }
339 down_write(&net_rwsem);
340 list_add_tail_rcu(&net->list, &net_namespace_list);
341 up_write(&net_rwsem);
342out:
343 return error;
344
345out_undo:
346 /* Walk through the list backwards calling the exit functions
347 * for the pernet modules whose init functions did not fail.
348 */
349 list_add(&net->exit_list, &net_exit_list);
350 saved_ops = ops;
351 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
352 ops_pre_exit_list(ops, &net_exit_list);
353
354 synchronize_rcu();
355
356 ops = saved_ops;
357 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
358 ops_exit_list(ops, &net_exit_list);
359
360 ops = saved_ops;
361 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
362 ops_free_list(ops, &net_exit_list);
363
364 rcu_barrier();
365 goto out;
366}
367
368static int __net_init net_defaults_init_net(struct net *net)
369{
370 net->core.sysctl_somaxconn = SOMAXCONN;
371 return 0;
372}
373
374static struct pernet_operations net_defaults_ops = {
375 .init = net_defaults_init_net,
376};
377
378static __init int net_defaults_init(void)
379{
380 if (register_pernet_subsys(&net_defaults_ops))
381 panic("Cannot initialize net default settings");
382
383 return 0;
384}
385
386core_initcall(net_defaults_init);
387
388#ifdef CONFIG_NET_NS
389static struct ucounts *inc_net_namespaces(struct user_namespace *ns)
390{
391 return inc_ucount(ns, current_euid(), UCOUNT_NET_NAMESPACES);
392}
393
394static void dec_net_namespaces(struct ucounts *ucounts)
395{
396 dec_ucount(ucounts, UCOUNT_NET_NAMESPACES);
397}
398
399static struct kmem_cache *net_cachep __ro_after_init;
400static struct workqueue_struct *netns_wq;
401
402static struct net *net_alloc(void)
403{
404 struct net *net = NULL;
405 struct net_generic *ng;
406
407 ng = net_alloc_generic();
408 if (!ng)
409 goto out;
410
411 net = kmem_cache_zalloc(net_cachep, GFP_KERNEL);
412 if (!net)
413 goto out_free;
414
415#ifdef CONFIG_KEYS
416 net->key_domain = kzalloc(sizeof(struct key_tag), GFP_KERNEL);
417 if (!net->key_domain)
418 goto out_free_2;
419 refcount_set(&net->key_domain->usage, 1);
420#endif
421
422 rcu_assign_pointer(net->gen, ng);
423out:
424 return net;
425
426#ifdef CONFIG_KEYS
427out_free_2:
428 kmem_cache_free(net_cachep, net);
429 net = NULL;
430#endif
431out_free:
432 kfree(ng);
433 goto out;
434}
435
436static void net_free(struct net *net)
437{
438 kfree(rcu_access_pointer(net->gen));
439 kmem_cache_free(net_cachep, net);
440}
441
442void net_drop_ns(void *p)
443{
444 struct net *ns = p;
445 if (ns && refcount_dec_and_test(&ns->passive))
446 net_free(ns);
447}
448
449struct net *copy_net_ns(unsigned long flags,
450 struct user_namespace *user_ns, struct net *old_net)
451{
452 struct ucounts *ucounts;
453 struct net *net;
454 int rv;
455
456 if (!(flags & CLONE_NEWNET))
457 return get_net(old_net);
458
459 ucounts = inc_net_namespaces(user_ns);
460 if (!ucounts)
461 return ERR_PTR(-ENOSPC);
462
463 net = net_alloc();
464 if (!net) {
465 rv = -ENOMEM;
466 goto dec_ucounts;
467 }
468 refcount_set(&net->passive, 1);
469 net->ucounts = ucounts;
470 get_user_ns(user_ns);
471
472 rv = down_read_killable(&pernet_ops_rwsem);
473 if (rv < 0)
474 goto put_userns;
475
476 rv = setup_net(net, user_ns);
477
478 up_read(&pernet_ops_rwsem);
479
480 if (rv < 0) {
481put_userns:
482 key_remove_domain(net->key_domain);
483 put_user_ns(user_ns);
484 net_drop_ns(net);
485dec_ucounts:
486 dec_net_namespaces(ucounts);
487 return ERR_PTR(rv);
488 }
489 return net;
490}
491
492/**
493 * net_ns_get_ownership - get sysfs ownership data for @net
494 * @net: network namespace in question (can be NULL)
495 * @uid: kernel user ID for sysfs objects
496 * @gid: kernel group ID for sysfs objects
497 *
498 * Returns the uid/gid pair of root in the user namespace associated with the
499 * given network namespace.
500 */
501void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid)
502{
503 if (net) {
504 kuid_t ns_root_uid = make_kuid(net->user_ns, 0);
505 kgid_t ns_root_gid = make_kgid(net->user_ns, 0);
506
507 if (uid_valid(ns_root_uid))
508 *uid = ns_root_uid;
509
510 if (gid_valid(ns_root_gid))
511 *gid = ns_root_gid;
512 } else {
513 *uid = GLOBAL_ROOT_UID;
514 *gid = GLOBAL_ROOT_GID;
515 }
516}
517EXPORT_SYMBOL_GPL(net_ns_get_ownership);
518
519static void unhash_nsid(struct net *net, struct net *last)
520{
521 struct net *tmp;
522 /* This function is only called from cleanup_net() work,
523 * and this work is the only process, that may delete
524 * a net from net_namespace_list. So, when the below
525 * is executing, the list may only grow. Thus, we do not
526 * use for_each_net_rcu() or net_rwsem.
527 */
528 for_each_net(tmp) {
529 int id;
530
531 spin_lock_bh(&tmp->nsid_lock);
532 id = __peernet2id(tmp, net);
533 if (id >= 0)
534 idr_remove(&tmp->netns_ids, id);
535 spin_unlock_bh(&tmp->nsid_lock);
536 if (id >= 0)
537 rtnl_net_notifyid(tmp, RTM_DELNSID, id, 0, NULL,
538 GFP_KERNEL);
539 if (tmp == last)
540 break;
541 }
542 spin_lock_bh(&net->nsid_lock);
543 idr_destroy(&net->netns_ids);
544 spin_unlock_bh(&net->nsid_lock);
545}
546
547static LLIST_HEAD(cleanup_list);
548
549static void cleanup_net(struct work_struct *work)
550{
551 const struct pernet_operations *ops;
552 struct net *net, *tmp, *last;
553 struct llist_node *net_kill_list;
554 LIST_HEAD(net_exit_list);
555
556 /* Atomically snapshot the list of namespaces to cleanup */
557 net_kill_list = llist_del_all(&cleanup_list);
558
559 down_read(&pernet_ops_rwsem);
560
561 /* Don't let anyone else find us. */
562 down_write(&net_rwsem);
563 llist_for_each_entry(net, net_kill_list, cleanup_list)
564 list_del_rcu(&net->list);
565 /* Cache last net. After we unlock rtnl, no one new net
566 * added to net_namespace_list can assign nsid pointer
567 * to a net from net_kill_list (see peernet2id_alloc()).
568 * So, we skip them in unhash_nsid().
569 *
570 * Note, that unhash_nsid() does not delete nsid links
571 * between net_kill_list's nets, as they've already
572 * deleted from net_namespace_list. But, this would be
573 * useless anyway, as netns_ids are destroyed there.
574 */
575 last = list_last_entry(&net_namespace_list, struct net, list);
576 up_write(&net_rwsem);
577
578 llist_for_each_entry(net, net_kill_list, cleanup_list) {
579 unhash_nsid(net, last);
580 list_add_tail(&net->exit_list, &net_exit_list);
581 }
582
583 /* Run all of the network namespace pre_exit methods */
584 list_for_each_entry_reverse(ops, &pernet_list, list)
585 ops_pre_exit_list(ops, &net_exit_list);
586
587 /*
588 * Another CPU might be rcu-iterating the list, wait for it.
589 * This needs to be before calling the exit() notifiers, so
590 * the rcu_barrier() below isn't sufficient alone.
591 * Also the pre_exit() and exit() methods need this barrier.
592 */
593 synchronize_rcu();
594
595 /* Run all of the network namespace exit methods */
596 list_for_each_entry_reverse(ops, &pernet_list, list)
597 ops_exit_list(ops, &net_exit_list);
598
599 /* Free the net generic variables */
600 list_for_each_entry_reverse(ops, &pernet_list, list)
601 ops_free_list(ops, &net_exit_list);
602
603 up_read(&pernet_ops_rwsem);
604
605 /* Ensure there are no outstanding rcu callbacks using this
606 * network namespace.
607 */
608 rcu_barrier();
609
610 /* Finally it is safe to free my network namespace structure */
611 list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
612 list_del_init(&net->exit_list);
613 dec_net_namespaces(net->ucounts);
614 key_remove_domain(net->key_domain);
615 put_user_ns(net->user_ns);
616 net_drop_ns(net);
617 }
618}
619
620/**
621 * net_ns_barrier - wait until concurrent net_cleanup_work is done
622 *
623 * cleanup_net runs from work queue and will first remove namespaces
624 * from the global list, then run net exit functions.
625 *
626 * Call this in module exit path to make sure that all netns
627 * ->exit ops have been invoked before the function is removed.
628 */
629void net_ns_barrier(void)
630{
631 down_write(&pernet_ops_rwsem);
632 up_write(&pernet_ops_rwsem);
633}
634EXPORT_SYMBOL(net_ns_barrier);
635
636static DECLARE_WORK(net_cleanup_work, cleanup_net);
637
638void __put_net(struct net *net)
639{
640 /* Cleanup the network namespace in process context */
641 if (llist_add(&net->cleanup_list, &cleanup_list))
642 queue_work(netns_wq, &net_cleanup_work);
643}
644EXPORT_SYMBOL_GPL(__put_net);
645
646struct net *get_net_ns_by_fd(int fd)
647{
648 struct file *file;
649 struct ns_common *ns;
650 struct net *net;
651
652 file = proc_ns_fget(fd);
653 if (IS_ERR(file))
654 return ERR_CAST(file);
655
656 ns = get_proc_ns(file_inode(file));
657 if (ns->ops == &netns_operations)
658 net = get_net(container_of(ns, struct net, ns));
659 else
660 net = ERR_PTR(-EINVAL);
661
662 fput(file);
663 return net;
664}
665
666#else
667struct net *get_net_ns_by_fd(int fd)
668{
669 return ERR_PTR(-EINVAL);
670}
671#endif
672EXPORT_SYMBOL_GPL(get_net_ns_by_fd);
673
674struct net *get_net_ns_by_pid(pid_t pid)
675{
676 struct task_struct *tsk;
677 struct net *net;
678
679 /* Lookup the network namespace */
680 net = ERR_PTR(-ESRCH);
681 rcu_read_lock();
682 tsk = find_task_by_vpid(pid);
683 if (tsk) {
684 struct nsproxy *nsproxy;
685 task_lock(tsk);
686 nsproxy = tsk->nsproxy;
687 if (nsproxy)
688 net = get_net(nsproxy->net_ns);
689 task_unlock(tsk);
690 }
691 rcu_read_unlock();
692 return net;
693}
694EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
695
696static __net_init int net_ns_net_init(struct net *net)
697{
698#ifdef CONFIG_NET_NS
699 net->ns.ops = &netns_operations;
700#endif
701 return ns_alloc_inum(&net->ns);
702}
703
704static __net_exit void net_ns_net_exit(struct net *net)
705{
706 ns_free_inum(&net->ns);
707}
708
709static struct pernet_operations __net_initdata net_ns_ops = {
710 .init = net_ns_net_init,
711 .exit = net_ns_net_exit,
712};
713
714static const struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = {
715 [NETNSA_NONE] = { .type = NLA_UNSPEC },
716 [NETNSA_NSID] = { .type = NLA_S32 },
717 [NETNSA_PID] = { .type = NLA_U32 },
718 [NETNSA_FD] = { .type = NLA_U32 },
719 [NETNSA_TARGET_NSID] = { .type = NLA_S32 },
720};
721
722static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh,
723 struct netlink_ext_ack *extack)
724{
725 struct net *net = sock_net(skb->sk);
726 struct nlattr *tb[NETNSA_MAX + 1];
727 struct nlattr *nla;
728 struct net *peer;
729 int nsid, err;
730
731 err = nlmsg_parse_deprecated(nlh, sizeof(struct rtgenmsg), tb,
732 NETNSA_MAX, rtnl_net_policy, extack);
733 if (err < 0)
734 return err;
735 if (!tb[NETNSA_NSID]) {
736 NL_SET_ERR_MSG(extack, "nsid is missing");
737 return -EINVAL;
738 }
739 nsid = nla_get_s32(tb[NETNSA_NSID]);
740
741 if (tb[NETNSA_PID]) {
742 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
743 nla = tb[NETNSA_PID];
744 } else if (tb[NETNSA_FD]) {
745 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
746 nla = tb[NETNSA_FD];
747 } else {
748 NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
749 return -EINVAL;
750 }
751 if (IS_ERR(peer)) {
752 NL_SET_BAD_ATTR(extack, nla);
753 NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
754 return PTR_ERR(peer);
755 }
756
757 spin_lock_bh(&net->nsid_lock);
758 if (__peernet2id(net, peer) >= 0) {
759 spin_unlock_bh(&net->nsid_lock);
760 err = -EEXIST;
761 NL_SET_BAD_ATTR(extack, nla);
762 NL_SET_ERR_MSG(extack,
763 "Peer netns already has a nsid assigned");
764 goto out;
765 }
766
767 err = alloc_netid(net, peer, nsid);
768 spin_unlock_bh(&net->nsid_lock);
769 if (err >= 0) {
770 rtnl_net_notifyid(net, RTM_NEWNSID, err, NETLINK_CB(skb).portid,
771 nlh, GFP_KERNEL);
772 err = 0;
773 } else if (err == -ENOSPC && nsid >= 0) {
774 err = -EEXIST;
775 NL_SET_BAD_ATTR(extack, tb[NETNSA_NSID]);
776 NL_SET_ERR_MSG(extack, "The specified nsid is already used");
777 }
778out:
779 put_net(peer);
780 return err;
781}
782
783static int rtnl_net_get_size(void)
784{
785 return NLMSG_ALIGN(sizeof(struct rtgenmsg))
786 + nla_total_size(sizeof(s32)) /* NETNSA_NSID */
787 + nla_total_size(sizeof(s32)) /* NETNSA_CURRENT_NSID */
788 ;
789}
790
791struct net_fill_args {
792 u32 portid;
793 u32 seq;
794 int flags;
795 int cmd;
796 int nsid;
797 bool add_ref;
798 int ref_nsid;
799};
800
801static int rtnl_net_fill(struct sk_buff *skb, struct net_fill_args *args)
802{
803 struct nlmsghdr *nlh;
804 struct rtgenmsg *rth;
805
806 nlh = nlmsg_put(skb, args->portid, args->seq, args->cmd, sizeof(*rth),
807 args->flags);
808 if (!nlh)
809 return -EMSGSIZE;
810
811 rth = nlmsg_data(nlh);
812 rth->rtgen_family = AF_UNSPEC;
813
814 if (nla_put_s32(skb, NETNSA_NSID, args->nsid))
815 goto nla_put_failure;
816
817 if (args->add_ref &&
818 nla_put_s32(skb, NETNSA_CURRENT_NSID, args->ref_nsid))
819 goto nla_put_failure;
820
821 nlmsg_end(skb, nlh);
822 return 0;
823
824nla_put_failure:
825 nlmsg_cancel(skb, nlh);
826 return -EMSGSIZE;
827}
828
829static int rtnl_net_valid_getid_req(struct sk_buff *skb,
830 const struct nlmsghdr *nlh,
831 struct nlattr **tb,
832 struct netlink_ext_ack *extack)
833{
834 int i, err;
835
836 if (!netlink_strict_get_check(skb))
837 return nlmsg_parse_deprecated(nlh, sizeof(struct rtgenmsg),
838 tb, NETNSA_MAX, rtnl_net_policy,
839 extack);
840
841 err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct rtgenmsg), tb,
842 NETNSA_MAX, rtnl_net_policy,
843 extack);
844 if (err)
845 return err;
846
847 for (i = 0; i <= NETNSA_MAX; i++) {
848 if (!tb[i])
849 continue;
850
851 switch (i) {
852 case NETNSA_PID:
853 case NETNSA_FD:
854 case NETNSA_NSID:
855 case NETNSA_TARGET_NSID:
856 break;
857 default:
858 NL_SET_ERR_MSG(extack, "Unsupported attribute in peer netns getid request");
859 return -EINVAL;
860 }
861 }
862
863 return 0;
864}
865
866static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh,
867 struct netlink_ext_ack *extack)
868{
869 struct net *net = sock_net(skb->sk);
870 struct nlattr *tb[NETNSA_MAX + 1];
871 struct net_fill_args fillargs = {
872 .portid = NETLINK_CB(skb).portid,
873 .seq = nlh->nlmsg_seq,
874 .cmd = RTM_NEWNSID,
875 };
876 struct net *peer, *target = net;
877 struct nlattr *nla;
878 struct sk_buff *msg;
879 int err;
880
881 err = rtnl_net_valid_getid_req(skb, nlh, tb, extack);
882 if (err < 0)
883 return err;
884 if (tb[NETNSA_PID]) {
885 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
886 nla = tb[NETNSA_PID];
887 } else if (tb[NETNSA_FD]) {
888 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
889 nla = tb[NETNSA_FD];
890 } else if (tb[NETNSA_NSID]) {
891 peer = get_net_ns_by_id(net, nla_get_s32(tb[NETNSA_NSID]));
892 if (!peer)
893 peer = ERR_PTR(-ENOENT);
894 nla = tb[NETNSA_NSID];
895 } else {
896 NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
897 return -EINVAL;
898 }
899
900 if (IS_ERR(peer)) {
901 NL_SET_BAD_ATTR(extack, nla);
902 NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
903 return PTR_ERR(peer);
904 }
905
906 if (tb[NETNSA_TARGET_NSID]) {
907 int id = nla_get_s32(tb[NETNSA_TARGET_NSID]);
908
909 target = rtnl_get_net_ns_capable(NETLINK_CB(skb).sk, id);
910 if (IS_ERR(target)) {
911 NL_SET_BAD_ATTR(extack, tb[NETNSA_TARGET_NSID]);
912 NL_SET_ERR_MSG(extack,
913 "Target netns reference is invalid");
914 err = PTR_ERR(target);
915 goto out;
916 }
917 fillargs.add_ref = true;
918 fillargs.ref_nsid = peernet2id(net, peer);
919 }
920
921 msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
922 if (!msg) {
923 err = -ENOMEM;
924 goto out;
925 }
926
927 fillargs.nsid = peernet2id(target, peer);
928 err = rtnl_net_fill(msg, &fillargs);
929 if (err < 0)
930 goto err_out;
931
932 err = rtnl_unicast(msg, net, NETLINK_CB(skb).portid);
933 goto out;
934
935err_out:
936 nlmsg_free(msg);
937out:
938 if (fillargs.add_ref)
939 put_net(target);
940 put_net(peer);
941 return err;
942}
943
944struct rtnl_net_dump_cb {
945 struct net *tgt_net;
946 struct net *ref_net;
947 struct sk_buff *skb;
948 struct net_fill_args fillargs;
949 int idx;
950 int s_idx;
951};
952
953static int rtnl_net_dumpid_one(int id, void *peer, void *data)
954{
955 struct rtnl_net_dump_cb *net_cb = (struct rtnl_net_dump_cb *)data;
956 int ret;
957
958 if (net_cb->idx < net_cb->s_idx)
959 goto cont;
960
961 net_cb->fillargs.nsid = id;
962 if (net_cb->fillargs.add_ref)
963 net_cb->fillargs.ref_nsid = __peernet2id(net_cb->ref_net, peer);
964 ret = rtnl_net_fill(net_cb->skb, &net_cb->fillargs);
965 if (ret < 0)
966 return ret;
967
968cont:
969 net_cb->idx++;
970 return 0;
971}
972
973static int rtnl_valid_dump_net_req(const struct nlmsghdr *nlh, struct sock *sk,
974 struct rtnl_net_dump_cb *net_cb,
975 struct netlink_callback *cb)
976{
977 struct netlink_ext_ack *extack = cb->extack;
978 struct nlattr *tb[NETNSA_MAX + 1];
979 int err, i;
980
981 err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct rtgenmsg), tb,
982 NETNSA_MAX, rtnl_net_policy,
983 extack);
984 if (err < 0)
985 return err;
986
987 for (i = 0; i <= NETNSA_MAX; i++) {
988 if (!tb[i])
989 continue;
990
991 if (i == NETNSA_TARGET_NSID) {
992 struct net *net;
993
994 net = rtnl_get_net_ns_capable(sk, nla_get_s32(tb[i]));
995 if (IS_ERR(net)) {
996 NL_SET_BAD_ATTR(extack, tb[i]);
997 NL_SET_ERR_MSG(extack,
998 "Invalid target network namespace id");
999 return PTR_ERR(net);
1000 }
1001 net_cb->fillargs.add_ref = true;
1002 net_cb->ref_net = net_cb->tgt_net;
1003 net_cb->tgt_net = net;
1004 } else {
1005 NL_SET_BAD_ATTR(extack, tb[i]);
1006 NL_SET_ERR_MSG(extack,
1007 "Unsupported attribute in dump request");
1008 return -EINVAL;
1009 }
1010 }
1011
1012 return 0;
1013}
1014
1015static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb)
1016{
1017 struct rtnl_net_dump_cb net_cb = {
1018 .tgt_net = sock_net(skb->sk),
1019 .skb = skb,
1020 .fillargs = {
1021 .portid = NETLINK_CB(cb->skb).portid,
1022 .seq = cb->nlh->nlmsg_seq,
1023 .flags = NLM_F_MULTI,
1024 .cmd = RTM_NEWNSID,
1025 },
1026 .idx = 0,
1027 .s_idx = cb->args[0],
1028 };
1029 int err = 0;
1030
1031 if (cb->strict_check) {
1032 err = rtnl_valid_dump_net_req(cb->nlh, skb->sk, &net_cb, cb);
1033 if (err < 0)
1034 goto end;
1035 }
1036
1037 spin_lock_bh(&net_cb.tgt_net->nsid_lock);
1038 if (net_cb.fillargs.add_ref &&
1039 !net_eq(net_cb.ref_net, net_cb.tgt_net) &&
1040 !spin_trylock_bh(&net_cb.ref_net->nsid_lock)) {
1041 spin_unlock_bh(&net_cb.tgt_net->nsid_lock);
1042 err = -EAGAIN;
1043 goto end;
1044 }
1045 idr_for_each(&net_cb.tgt_net->netns_ids, rtnl_net_dumpid_one, &net_cb);
1046 if (net_cb.fillargs.add_ref &&
1047 !net_eq(net_cb.ref_net, net_cb.tgt_net))
1048 spin_unlock_bh(&net_cb.ref_net->nsid_lock);
1049 spin_unlock_bh(&net_cb.tgt_net->nsid_lock);
1050
1051 cb->args[0] = net_cb.idx;
1052end:
1053 if (net_cb.fillargs.add_ref)
1054 put_net(net_cb.tgt_net);
1055 return err < 0 ? err : skb->len;
1056}
1057
1058static void rtnl_net_notifyid(struct net *net, int cmd, int id, u32 portid,
1059 struct nlmsghdr *nlh, gfp_t gfp)
1060{
1061 struct net_fill_args fillargs = {
1062 .portid = portid,
1063 .seq = nlh ? nlh->nlmsg_seq : 0,
1064 .cmd = cmd,
1065 .nsid = id,
1066 };
1067 struct sk_buff *msg;
1068 int err = -ENOMEM;
1069
1070 msg = nlmsg_new(rtnl_net_get_size(), gfp);
1071 if (!msg)
1072 goto out;
1073
1074 err = rtnl_net_fill(msg, &fillargs);
1075 if (err < 0)
1076 goto err_out;
1077
1078 rtnl_notify(msg, net, portid, RTNLGRP_NSID, nlh, gfp);
1079 return;
1080
1081err_out:
1082 nlmsg_free(msg);
1083out:
1084 rtnl_set_sk_err(net, RTNLGRP_NSID, err);
1085}
1086
1087static int __init net_ns_init(void)
1088{
1089 struct net_generic *ng;
1090
1091#ifdef CONFIG_NET_NS
1092 net_cachep = kmem_cache_create("net_namespace", sizeof(struct net),
1093 SMP_CACHE_BYTES,
1094 SLAB_PANIC|SLAB_ACCOUNT, NULL);
1095
1096 /* Create workqueue for cleanup */
1097 netns_wq = create_singlethread_workqueue("netns");
1098 if (!netns_wq)
1099 panic("Could not create netns workq");
1100#endif
1101
1102 ng = net_alloc_generic();
1103 if (!ng)
1104 panic("Could not allocate generic netns");
1105
1106 rcu_assign_pointer(init_net.gen, ng);
1107
1108 down_write(&pernet_ops_rwsem);
1109 if (setup_net(&init_net, &init_user_ns))
1110 panic("Could not setup the initial network namespace");
1111
1112 init_net_initialized = true;
1113 up_write(&pernet_ops_rwsem);
1114
1115 if (register_pernet_subsys(&net_ns_ops))
1116 panic("Could not register network namespace subsystems");
1117
1118 rtnl_register(PF_UNSPEC, RTM_NEWNSID, rtnl_net_newid, NULL,
1119 RTNL_FLAG_DOIT_UNLOCKED);
1120 rtnl_register(PF_UNSPEC, RTM_GETNSID, rtnl_net_getid, rtnl_net_dumpid,
1121 RTNL_FLAG_DOIT_UNLOCKED);
1122
1123 return 0;
1124}
1125
1126pure_initcall(net_ns_init);
1127
1128#ifdef CONFIG_NET_NS
1129static int __register_pernet_operations(struct list_head *list,
1130 struct pernet_operations *ops)
1131{
1132 struct net *net;
1133 int error;
1134 LIST_HEAD(net_exit_list);
1135
1136 list_add_tail(&ops->list, list);
1137 if (ops->init || (ops->id && ops->size)) {
1138 /* We held write locked pernet_ops_rwsem, and parallel
1139 * setup_net() and cleanup_net() are not possible.
1140 */
1141 for_each_net(net) {
1142 error = ops_init(ops, net);
1143 if (error)
1144 goto out_undo;
1145 list_add_tail(&net->exit_list, &net_exit_list);
1146 }
1147 }
1148 return 0;
1149
1150out_undo:
1151 /* If I have an error cleanup all namespaces I initialized */
1152 list_del(&ops->list);
1153 ops_pre_exit_list(ops, &net_exit_list);
1154 synchronize_rcu();
1155 ops_exit_list(ops, &net_exit_list);
1156 ops_free_list(ops, &net_exit_list);
1157 return error;
1158}
1159
1160static void __unregister_pernet_operations(struct pernet_operations *ops)
1161{
1162 struct net *net;
1163 LIST_HEAD(net_exit_list);
1164
1165 list_del(&ops->list);
1166 /* See comment in __register_pernet_operations() */
1167 for_each_net(net)
1168 list_add_tail(&net->exit_list, &net_exit_list);
1169 ops_pre_exit_list(ops, &net_exit_list);
1170 synchronize_rcu();
1171 ops_exit_list(ops, &net_exit_list);
1172 ops_free_list(ops, &net_exit_list);
1173}
1174
1175#else
1176
1177static int __register_pernet_operations(struct list_head *list,
1178 struct pernet_operations *ops)
1179{
1180 if (!init_net_initialized) {
1181 list_add_tail(&ops->list, list);
1182 return 0;
1183 }
1184
1185 return ops_init(ops, &init_net);
1186}
1187
1188static void __unregister_pernet_operations(struct pernet_operations *ops)
1189{
1190 if (!init_net_initialized) {
1191 list_del(&ops->list);
1192 } else {
1193 LIST_HEAD(net_exit_list);
1194 list_add(&init_net.exit_list, &net_exit_list);
1195 ops_pre_exit_list(ops, &net_exit_list);
1196 synchronize_rcu();
1197 ops_exit_list(ops, &net_exit_list);
1198 ops_free_list(ops, &net_exit_list);
1199 }
1200}
1201
1202#endif /* CONFIG_NET_NS */
1203
1204static DEFINE_IDA(net_generic_ids);
1205
1206static int register_pernet_operations(struct list_head *list,
1207 struct pernet_operations *ops)
1208{
1209 int error;
1210
1211 if (ops->id) {
1212 error = ida_alloc_min(&net_generic_ids, MIN_PERNET_OPS_ID,
1213 GFP_KERNEL);
1214 if (error < 0)
1215 return error;
1216 *ops->id = error;
1217 max_gen_ptrs = max(max_gen_ptrs, *ops->id + 1);
1218 }
1219 error = __register_pernet_operations(list, ops);
1220 if (error) {
1221 rcu_barrier();
1222 if (ops->id)
1223 ida_free(&net_generic_ids, *ops->id);
1224 }
1225
1226 return error;
1227}
1228
1229static void unregister_pernet_operations(struct pernet_operations *ops)
1230{
1231 __unregister_pernet_operations(ops);
1232 rcu_barrier();
1233 if (ops->id)
1234 ida_free(&net_generic_ids, *ops->id);
1235}
1236
1237/**
1238 * register_pernet_subsys - register a network namespace subsystem
1239 * @ops: pernet operations structure for the subsystem
1240 *
1241 * Register a subsystem which has init and exit functions
1242 * that are called when network namespaces are created and
1243 * destroyed respectively.
1244 *
1245 * When registered all network namespace init functions are
1246 * called for every existing network namespace. Allowing kernel
1247 * modules to have a race free view of the set of network namespaces.
1248 *
1249 * When a new network namespace is created all of the init
1250 * methods are called in the order in which they were registered.
1251 *
1252 * When a network namespace is destroyed all of the exit methods
1253 * are called in the reverse of the order with which they were
1254 * registered.
1255 */
1256int register_pernet_subsys(struct pernet_operations *ops)
1257{
1258 int error;
1259 down_write(&pernet_ops_rwsem);
1260 error = register_pernet_operations(first_device, ops);
1261 up_write(&pernet_ops_rwsem);
1262 return error;
1263}
1264EXPORT_SYMBOL_GPL(register_pernet_subsys);
1265
1266/**
1267 * unregister_pernet_subsys - unregister a network namespace subsystem
1268 * @ops: pernet operations structure to manipulate
1269 *
1270 * Remove the pernet operations structure from the list to be
1271 * used when network namespaces are created or destroyed. In
1272 * addition run the exit method for all existing network
1273 * namespaces.
1274 */
1275void unregister_pernet_subsys(struct pernet_operations *ops)
1276{
1277 down_write(&pernet_ops_rwsem);
1278 unregister_pernet_operations(ops);
1279 up_write(&pernet_ops_rwsem);
1280}
1281EXPORT_SYMBOL_GPL(unregister_pernet_subsys);
1282
1283/**
1284 * register_pernet_device - register a network namespace device
1285 * @ops: pernet operations structure for the subsystem
1286 *
1287 * Register a device which has init and exit functions
1288 * that are called when network namespaces are created and
1289 * destroyed respectively.
1290 *
1291 * When registered all network namespace init functions are
1292 * called for every existing network namespace. Allowing kernel
1293 * modules to have a race free view of the set of network namespaces.
1294 *
1295 * When a new network namespace is created all of the init
1296 * methods are called in the order in which they were registered.
1297 *
1298 * When a network namespace is destroyed all of the exit methods
1299 * are called in the reverse of the order with which they were
1300 * registered.
1301 */
1302int register_pernet_device(struct pernet_operations *ops)
1303{
1304 int error;
1305 down_write(&pernet_ops_rwsem);
1306 error = register_pernet_operations(&pernet_list, ops);
1307 if (!error && (first_device == &pernet_list))
1308 first_device = &ops->list;
1309 up_write(&pernet_ops_rwsem);
1310 return error;
1311}
1312EXPORT_SYMBOL_GPL(register_pernet_device);
1313
1314/**
1315 * unregister_pernet_device - unregister a network namespace netdevice
1316 * @ops: pernet operations structure to manipulate
1317 *
1318 * Remove the pernet operations structure from the list to be
1319 * used when network namespaces are created or destroyed. In
1320 * addition run the exit method for all existing network
1321 * namespaces.
1322 */
1323void unregister_pernet_device(struct pernet_operations *ops)
1324{
1325 down_write(&pernet_ops_rwsem);
1326 if (&ops->list == first_device)
1327 first_device = first_device->next;
1328 unregister_pernet_operations(ops);
1329 up_write(&pernet_ops_rwsem);
1330}
1331EXPORT_SYMBOL_GPL(unregister_pernet_device);
1332
1333#ifdef CONFIG_NET_NS
1334static struct ns_common *netns_get(struct task_struct *task)
1335{
1336 struct net *net = NULL;
1337 struct nsproxy *nsproxy;
1338
1339 task_lock(task);
1340 nsproxy = task->nsproxy;
1341 if (nsproxy)
1342 net = get_net(nsproxy->net_ns);
1343 task_unlock(task);
1344
1345 return net ? &net->ns : NULL;
1346}
1347
1348static inline struct net *to_net_ns(struct ns_common *ns)
1349{
1350 return container_of(ns, struct net, ns);
1351}
1352
1353static void netns_put(struct ns_common *ns)
1354{
1355 put_net(to_net_ns(ns));
1356}
1357
1358static int netns_install(struct nsproxy *nsproxy, struct ns_common *ns)
1359{
1360 struct net *net = to_net_ns(ns);
1361
1362 if (!ns_capable(net->user_ns, CAP_SYS_ADMIN) ||
1363 !ns_capable(current_user_ns(), CAP_SYS_ADMIN))
1364 return -EPERM;
1365
1366 put_net(nsproxy->net_ns);
1367 nsproxy->net_ns = get_net(net);
1368 return 0;
1369}
1370
1371static struct user_namespace *netns_owner(struct ns_common *ns)
1372{
1373 return to_net_ns(ns)->user_ns;
1374}
1375
1376const struct proc_ns_operations netns_operations = {
1377 .name = "net",
1378 .type = CLONE_NEWNET,
1379 .get = netns_get,
1380 .put = netns_put,
1381 .install = netns_install,
1382 .owner = netns_owner,
1383};
1384#endif