1 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
14 #include <linux/proc_ns.h>
15 #include <linux/file.h>
16 #include <linux/export.h>
17 #include <linux/user_namespace.h>
18 #include <linux/net_namespace.h>
20 #include <net/netlink.h>
21 #include <net/net_namespace.h>
22 #include <net/netns/generic.h>
25 * Our network namespace constructor/destructor lists
28 static LIST_HEAD(pernet_list
);
29 static struct list_head
*first_device
= &pernet_list
;
30 DEFINE_MUTEX(net_mutex
);
32 LIST_HEAD(net_namespace_list
);
33 EXPORT_SYMBOL_GPL(net_namespace_list
);
35 struct net init_net
= {
36 .dev_base_head
= LIST_HEAD_INIT(init_net
.dev_base_head
),
38 EXPORT_SYMBOL(init_net
);
40 static bool init_net_initialized
;
42 #define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */
44 static unsigned int max_gen_ptrs
= INITIAL_NET_GEN_PTRS
;
46 static struct net_generic
*net_alloc_generic(void)
48 struct net_generic
*ng
;
49 size_t generic_size
= offsetof(struct net_generic
, ptr
[max_gen_ptrs
]);
51 ng
= kzalloc(generic_size
, GFP_KERNEL
);
53 ng
->len
= max_gen_ptrs
;
58 static int net_assign_generic(struct net
*net
, int id
, void *data
)
60 struct net_generic
*ng
, *old_ng
;
62 BUG_ON(!mutex_is_locked(&net_mutex
));
65 old_ng
= rcu_dereference_protected(net
->gen
,
66 lockdep_is_held(&net_mutex
));
68 if (old_ng
->len
>= id
)
71 ng
= net_alloc_generic();
76 * Some synchronisation notes:
78 * The net_generic explores the net->gen array inside rcu
79 * read section. Besides once set the net->gen->ptr[x]
80 * pointer never changes (see rules in netns/generic.h).
82 * That said, we simply duplicate this array and schedule
83 * the old copy for kfree after a grace period.
86 memcpy(&ng
->ptr
, &old_ng
->ptr
, old_ng
->len
* sizeof(void*));
88 rcu_assign_pointer(net
->gen
, ng
);
89 kfree_rcu(old_ng
, rcu
);
91 ng
->ptr
[id
- 1] = data
;
95 static int ops_init(const struct pernet_operations
*ops
, struct net
*net
)
100 if (ops
->id
&& ops
->size
) {
101 data
= kzalloc(ops
->size
, GFP_KERNEL
);
105 err
= net_assign_generic(net
, *ops
->id
, data
);
111 err
= ops
->init(net
);
122 static void ops_free(const struct pernet_operations
*ops
, struct net
*net
)
124 if (ops
->id
&& ops
->size
) {
126 kfree(net_generic(net
, id
));
130 static void ops_exit_list(const struct pernet_operations
*ops
,
131 struct list_head
*net_exit_list
)
135 list_for_each_entry(net
, net_exit_list
, exit_list
)
139 ops
->exit_batch(net_exit_list
);
142 static void ops_free_list(const struct pernet_operations
*ops
,
143 struct list_head
*net_exit_list
)
146 if (ops
->size
&& ops
->id
) {
147 list_for_each_entry(net
, net_exit_list
, exit_list
)
152 /* should be called with nsid_lock held */
153 static int alloc_netid(struct net
*net
, struct net
*peer
, int reqid
)
155 int min
= 0, max
= 0;
162 return idr_alloc(&net
->netns_ids
, peer
, min
, max
, GFP_ATOMIC
);
165 /* This function is used by idr_for_each(). If net is equal to peer, the
166 * function returns the id so that idr_for_each() stops. Because we cannot
167 * returns the id 0 (idr_for_each() will not stop), we return the magic value
168 * NET_ID_ZERO (-1) for it.
170 #define NET_ID_ZERO -1
171 static int net_eq_idr(int id
, void *net
, void *peer
)
173 if (net_eq(net
, peer
))
174 return id
? : NET_ID_ZERO
;
178 /* Should be called with nsid_lock held. If a new id is assigned, the bool alloc
179 * is set to true, thus the caller knows that the new id must be notified via
182 static int __peernet2id_alloc(struct net
*net
, struct net
*peer
, bool *alloc
)
184 int id
= idr_for_each(&net
->netns_ids
, net_eq_idr
, peer
);
185 bool alloc_it
= *alloc
;
189 /* Magic value for id 0. */
190 if (id
== NET_ID_ZERO
)
196 id
= alloc_netid(net
, peer
, -1);
198 return id
>= 0 ? id
: NETNSA_NSID_NOT_ASSIGNED
;
201 return NETNSA_NSID_NOT_ASSIGNED
;
204 /* should be called with nsid_lock held */
205 static int __peernet2id(struct net
*net
, struct net
*peer
)
209 return __peernet2id_alloc(net
, peer
, &no
);
212 static void rtnl_net_notifyid(struct net
*net
, int cmd
, int id
);
213 /* This function returns the id of a peer netns. If no id is assigned, one will
214 * be allocated and returned.
216 int peernet2id_alloc(struct net
*net
, struct net
*peer
)
222 if (atomic_read(&net
->count
) == 0)
223 return NETNSA_NSID_NOT_ASSIGNED
;
224 spin_lock_irqsave(&net
->nsid_lock
, flags
);
225 alloc
= atomic_read(&peer
->count
) == 0 ? false : true;
226 id
= __peernet2id_alloc(net
, peer
, &alloc
);
227 spin_unlock_irqrestore(&net
->nsid_lock
, flags
);
228 if (alloc
&& id
>= 0)
229 rtnl_net_notifyid(net
, RTM_NEWNSID
, id
);
233 /* This function returns, if assigned, the id of a peer netns. */
234 int peernet2id(struct net
*net
, struct net
*peer
)
239 spin_lock_irqsave(&net
->nsid_lock
, flags
);
240 id
= __peernet2id(net
, peer
);
241 spin_unlock_irqrestore(&net
->nsid_lock
, flags
);
244 EXPORT_SYMBOL(peernet2id
);
246 /* This function returns true is the peer netns has an id assigned into the
249 bool peernet_has_id(struct net
*net
, struct net
*peer
)
251 return peernet2id(net
, peer
) >= 0;
254 struct net
*get_net_ns_by_id(struct net
*net
, int id
)
263 spin_lock_irqsave(&net
->nsid_lock
, flags
);
264 peer
= idr_find(&net
->netns_ids
, id
);
266 peer
= maybe_get_net(peer
);
267 spin_unlock_irqrestore(&net
->nsid_lock
, flags
);
274 * setup_net runs the initializers for the network namespace object.
276 static __net_init
int setup_net(struct net
*net
, struct user_namespace
*user_ns
)
278 /* Must be called with net_mutex held */
279 const struct pernet_operations
*ops
, *saved_ops
;
281 LIST_HEAD(net_exit_list
);
283 atomic_set(&net
->count
, 1);
284 atomic_set(&net
->passive
, 1);
285 net
->dev_base_seq
= 1;
286 net
->user_ns
= user_ns
;
287 idr_init(&net
->netns_ids
);
288 spin_lock_init(&net
->nsid_lock
);
290 list_for_each_entry(ops
, &pernet_list
, list
) {
291 error
= ops_init(ops
, net
);
299 /* Walk through the list backwards calling the exit functions
300 * for the pernet modules whose init functions did not fail.
302 list_add(&net
->exit_list
, &net_exit_list
);
304 list_for_each_entry_continue_reverse(ops
, &pernet_list
, list
)
305 ops_exit_list(ops
, &net_exit_list
);
308 list_for_each_entry_continue_reverse(ops
, &pernet_list
, list
)
309 ops_free_list(ops
, &net_exit_list
);
315 static int __net_init
net_defaults_init_net(struct net
*net
)
317 net
->core
.sysctl_somaxconn
= SOMAXCONN
;
321 static struct pernet_operations net_defaults_ops
= {
322 .init
= net_defaults_init_net
,
325 static __init
int net_defaults_init(void)
327 if (register_pernet_subsys(&net_defaults_ops
))
328 panic("Cannot initialize net default settings");
333 core_initcall(net_defaults_init
);
336 static struct ucounts
*inc_net_namespaces(struct user_namespace
*ns
)
338 return inc_ucount(ns
, current_euid(), UCOUNT_NET_NAMESPACES
);
341 static void dec_net_namespaces(struct ucounts
*ucounts
)
343 dec_ucount(ucounts
, UCOUNT_NET_NAMESPACES
);
346 static struct kmem_cache
*net_cachep
;
347 static struct workqueue_struct
*netns_wq
;
349 static struct net
*net_alloc(void)
351 struct net
*net
= NULL
;
352 struct net_generic
*ng
;
354 ng
= net_alloc_generic();
358 net
= kmem_cache_zalloc(net_cachep
, GFP_KERNEL
);
362 rcu_assign_pointer(net
->gen
, ng
);
371 static void net_free(struct net
*net
)
373 kfree(rcu_access_pointer(net
->gen
));
374 kmem_cache_free(net_cachep
, net
);
377 void net_drop_ns(void *p
)
380 if (ns
&& atomic_dec_and_test(&ns
->passive
))
384 struct net
*copy_net_ns(unsigned long flags
,
385 struct user_namespace
*user_ns
, struct net
*old_net
)
387 struct ucounts
*ucounts
;
391 if (!(flags
& CLONE_NEWNET
))
392 return get_net(old_net
);
394 ucounts
= inc_net_namespaces(user_ns
);
396 return ERR_PTR(-ENOSPC
);
400 dec_net_namespaces(ucounts
);
401 return ERR_PTR(-ENOMEM
);
404 get_user_ns(user_ns
);
406 mutex_lock(&net_mutex
);
407 net
->ucounts
= ucounts
;
408 rv
= setup_net(net
, user_ns
);
411 list_add_tail_rcu(&net
->list
, &net_namespace_list
);
414 mutex_unlock(&net_mutex
);
416 dec_net_namespaces(ucounts
);
417 put_user_ns(user_ns
);
424 static DEFINE_SPINLOCK(cleanup_list_lock
);
425 static LIST_HEAD(cleanup_list
); /* Must hold cleanup_list_lock to touch */
427 static void cleanup_net(struct work_struct
*work
)
429 const struct pernet_operations
*ops
;
430 struct net
*net
, *tmp
;
431 struct list_head net_kill_list
;
432 LIST_HEAD(net_exit_list
);
434 /* Atomically snapshot the list of namespaces to cleanup */
435 spin_lock_irq(&cleanup_list_lock
);
436 list_replace_init(&cleanup_list
, &net_kill_list
);
437 spin_unlock_irq(&cleanup_list_lock
);
439 mutex_lock(&net_mutex
);
441 /* Don't let anyone else find us. */
443 list_for_each_entry(net
, &net_kill_list
, cleanup_list
) {
444 list_del_rcu(&net
->list
);
445 list_add_tail(&net
->exit_list
, &net_exit_list
);
449 spin_lock_irq(&tmp
->nsid_lock
);
450 id
= __peernet2id(tmp
, net
);
452 idr_remove(&tmp
->netns_ids
, id
);
453 spin_unlock_irq(&tmp
->nsid_lock
);
455 rtnl_net_notifyid(tmp
, RTM_DELNSID
, id
);
457 spin_lock_irq(&net
->nsid_lock
);
458 idr_destroy(&net
->netns_ids
);
459 spin_unlock_irq(&net
->nsid_lock
);
465 * Another CPU might be rcu-iterating the list, wait for it.
466 * This needs to be before calling the exit() notifiers, so
467 * the rcu_barrier() below isn't sufficient alone.
471 /* Run all of the network namespace exit methods */
472 list_for_each_entry_reverse(ops
, &pernet_list
, list
)
473 ops_exit_list(ops
, &net_exit_list
);
475 /* Free the net generic variables */
476 list_for_each_entry_reverse(ops
, &pernet_list
, list
)
477 ops_free_list(ops
, &net_exit_list
);
479 mutex_unlock(&net_mutex
);
481 /* Ensure there are no outstanding rcu callbacks using this
486 /* Finally it is safe to free my network namespace structure */
487 list_for_each_entry_safe(net
, tmp
, &net_exit_list
, exit_list
) {
488 list_del_init(&net
->exit_list
);
489 dec_net_namespaces(net
->ucounts
);
490 put_user_ns(net
->user_ns
);
494 static DECLARE_WORK(net_cleanup_work
, cleanup_net
);
496 void __put_net(struct net
*net
)
498 /* Cleanup the network namespace in process context */
501 spin_lock_irqsave(&cleanup_list_lock
, flags
);
502 list_add(&net
->cleanup_list
, &cleanup_list
);
503 spin_unlock_irqrestore(&cleanup_list_lock
, flags
);
505 queue_work(netns_wq
, &net_cleanup_work
);
507 EXPORT_SYMBOL_GPL(__put_net
);
509 struct net
*get_net_ns_by_fd(int fd
)
512 struct ns_common
*ns
;
515 file
= proc_ns_fget(fd
);
517 return ERR_CAST(file
);
519 ns
= get_proc_ns(file_inode(file
));
520 if (ns
->ops
== &netns_operations
)
521 net
= get_net(container_of(ns
, struct net
, ns
));
523 net
= ERR_PTR(-EINVAL
);
530 struct net
*get_net_ns_by_fd(int fd
)
532 return ERR_PTR(-EINVAL
);
535 EXPORT_SYMBOL_GPL(get_net_ns_by_fd
);
537 struct net
*get_net_ns_by_pid(pid_t pid
)
539 struct task_struct
*tsk
;
542 /* Lookup the network namespace */
543 net
= ERR_PTR(-ESRCH
);
545 tsk
= find_task_by_vpid(pid
);
547 struct nsproxy
*nsproxy
;
549 nsproxy
= tsk
->nsproxy
;
551 net
= get_net(nsproxy
->net_ns
);
557 EXPORT_SYMBOL_GPL(get_net_ns_by_pid
);
559 static __net_init
int net_ns_net_init(struct net
*net
)
562 net
->ns
.ops
= &netns_operations
;
564 return ns_alloc_inum(&net
->ns
);
567 static __net_exit
void net_ns_net_exit(struct net
*net
)
569 ns_free_inum(&net
->ns
);
572 static struct pernet_operations __net_initdata net_ns_ops
= {
573 .init
= net_ns_net_init
,
574 .exit
= net_ns_net_exit
,
577 static const struct nla_policy rtnl_net_policy
[NETNSA_MAX
+ 1] = {
578 [NETNSA_NONE
] = { .type
= NLA_UNSPEC
},
579 [NETNSA_NSID
] = { .type
= NLA_S32
},
580 [NETNSA_PID
] = { .type
= NLA_U32
},
581 [NETNSA_FD
] = { .type
= NLA_U32
},
584 static int rtnl_net_newid(struct sk_buff
*skb
, struct nlmsghdr
*nlh
)
586 struct net
*net
= sock_net(skb
->sk
);
587 struct nlattr
*tb
[NETNSA_MAX
+ 1];
592 err
= nlmsg_parse(nlh
, sizeof(struct rtgenmsg
), tb
, NETNSA_MAX
,
596 if (!tb
[NETNSA_NSID
])
598 nsid
= nla_get_s32(tb
[NETNSA_NSID
]);
601 peer
= get_net_ns_by_pid(nla_get_u32(tb
[NETNSA_PID
]));
602 else if (tb
[NETNSA_FD
])
603 peer
= get_net_ns_by_fd(nla_get_u32(tb
[NETNSA_FD
]));
607 return PTR_ERR(peer
);
609 spin_lock_irqsave(&net
->nsid_lock
, flags
);
610 if (__peernet2id(net
, peer
) >= 0) {
611 spin_unlock_irqrestore(&net
->nsid_lock
, flags
);
616 err
= alloc_netid(net
, peer
, nsid
);
617 spin_unlock_irqrestore(&net
->nsid_lock
, flags
);
619 rtnl_net_notifyid(net
, RTM_NEWNSID
, err
);
627 static int rtnl_net_get_size(void)
629 return NLMSG_ALIGN(sizeof(struct rtgenmsg
))
630 + nla_total_size(sizeof(s32
)) /* NETNSA_NSID */
634 static int rtnl_net_fill(struct sk_buff
*skb
, u32 portid
, u32 seq
, int flags
,
635 int cmd
, struct net
*net
, int nsid
)
637 struct nlmsghdr
*nlh
;
638 struct rtgenmsg
*rth
;
640 nlh
= nlmsg_put(skb
, portid
, seq
, cmd
, sizeof(*rth
), flags
);
644 rth
= nlmsg_data(nlh
);
645 rth
->rtgen_family
= AF_UNSPEC
;
647 if (nla_put_s32(skb
, NETNSA_NSID
, nsid
))
648 goto nla_put_failure
;
654 nlmsg_cancel(skb
, nlh
);
658 static int rtnl_net_getid(struct sk_buff
*skb
, struct nlmsghdr
*nlh
)
660 struct net
*net
= sock_net(skb
->sk
);
661 struct nlattr
*tb
[NETNSA_MAX
+ 1];
666 err
= nlmsg_parse(nlh
, sizeof(struct rtgenmsg
), tb
, NETNSA_MAX
,
671 peer
= get_net_ns_by_pid(nla_get_u32(tb
[NETNSA_PID
]));
672 else if (tb
[NETNSA_FD
])
673 peer
= get_net_ns_by_fd(nla_get_u32(tb
[NETNSA_FD
]));
678 return PTR_ERR(peer
);
680 msg
= nlmsg_new(rtnl_net_get_size(), GFP_KERNEL
);
686 id
= peernet2id(net
, peer
);
687 err
= rtnl_net_fill(msg
, NETLINK_CB(skb
).portid
, nlh
->nlmsg_seq
, 0,
688 RTM_NEWNSID
, net
, id
);
692 err
= rtnl_unicast(msg
, net
, NETLINK_CB(skb
).portid
);
702 struct rtnl_net_dump_cb
{
705 struct netlink_callback
*cb
;
710 static int rtnl_net_dumpid_one(int id
, void *peer
, void *data
)
712 struct rtnl_net_dump_cb
*net_cb
= (struct rtnl_net_dump_cb
*)data
;
715 if (net_cb
->idx
< net_cb
->s_idx
)
718 ret
= rtnl_net_fill(net_cb
->skb
, NETLINK_CB(net_cb
->cb
->skb
).portid
,
719 net_cb
->cb
->nlh
->nlmsg_seq
, NLM_F_MULTI
,
720 RTM_NEWNSID
, net_cb
->net
, id
);
729 static int rtnl_net_dumpid(struct sk_buff
*skb
, struct netlink_callback
*cb
)
731 struct net
*net
= sock_net(skb
->sk
);
732 struct rtnl_net_dump_cb net_cb
= {
737 .s_idx
= cb
->args
[0],
741 spin_lock_irqsave(&net
->nsid_lock
, flags
);
742 idr_for_each(&net
->netns_ids
, rtnl_net_dumpid_one
, &net_cb
);
743 spin_unlock_irqrestore(&net
->nsid_lock
, flags
);
745 cb
->args
[0] = net_cb
.idx
;
749 static void rtnl_net_notifyid(struct net
*net
, int cmd
, int id
)
754 msg
= nlmsg_new(rtnl_net_get_size(), GFP_KERNEL
);
758 err
= rtnl_net_fill(msg
, 0, 0, 0, cmd
, net
, id
);
762 rtnl_notify(msg
, net
, 0, RTNLGRP_NSID
, NULL
, 0);
768 rtnl_set_sk_err(net
, RTNLGRP_NSID
, err
);
771 static int __init
net_ns_init(void)
773 struct net_generic
*ng
;
776 net_cachep
= kmem_cache_create("net_namespace", sizeof(struct net
),
780 /* Create workqueue for cleanup */
781 netns_wq
= create_singlethread_workqueue("netns");
783 panic("Could not create netns workq");
786 ng
= net_alloc_generic();
788 panic("Could not allocate generic netns");
790 rcu_assign_pointer(init_net
.gen
, ng
);
792 mutex_lock(&net_mutex
);
793 if (setup_net(&init_net
, &init_user_ns
))
794 panic("Could not setup the initial network namespace");
796 init_net_initialized
= true;
799 list_add_tail_rcu(&init_net
.list
, &net_namespace_list
);
802 mutex_unlock(&net_mutex
);
804 register_pernet_subsys(&net_ns_ops
);
806 rtnl_register(PF_UNSPEC
, RTM_NEWNSID
, rtnl_net_newid
, NULL
, NULL
);
807 rtnl_register(PF_UNSPEC
, RTM_GETNSID
, rtnl_net_getid
, rtnl_net_dumpid
,
813 pure_initcall(net_ns_init
);
816 static int __register_pernet_operations(struct list_head
*list
,
817 struct pernet_operations
*ops
)
821 LIST_HEAD(net_exit_list
);
823 list_add_tail(&ops
->list
, list
);
824 if (ops
->init
|| (ops
->id
&& ops
->size
)) {
826 error
= ops_init(ops
, net
);
829 list_add_tail(&net
->exit_list
, &net_exit_list
);
835 /* If I have an error cleanup all namespaces I initialized */
836 list_del(&ops
->list
);
837 ops_exit_list(ops
, &net_exit_list
);
838 ops_free_list(ops
, &net_exit_list
);
842 static void __unregister_pernet_operations(struct pernet_operations
*ops
)
845 LIST_HEAD(net_exit_list
);
847 list_del(&ops
->list
);
849 list_add_tail(&net
->exit_list
, &net_exit_list
);
850 ops_exit_list(ops
, &net_exit_list
);
851 ops_free_list(ops
, &net_exit_list
);
856 static int __register_pernet_operations(struct list_head
*list
,
857 struct pernet_operations
*ops
)
859 if (!init_net_initialized
) {
860 list_add_tail(&ops
->list
, list
);
864 return ops_init(ops
, &init_net
);
867 static void __unregister_pernet_operations(struct pernet_operations
*ops
)
869 if (!init_net_initialized
) {
870 list_del(&ops
->list
);
872 LIST_HEAD(net_exit_list
);
873 list_add(&init_net
.exit_list
, &net_exit_list
);
874 ops_exit_list(ops
, &net_exit_list
);
875 ops_free_list(ops
, &net_exit_list
);
879 #endif /* CONFIG_NET_NS */
881 static DEFINE_IDA(net_generic_ids
);
883 static int register_pernet_operations(struct list_head
*list
,
884 struct pernet_operations
*ops
)
890 error
= ida_get_new_above(&net_generic_ids
, 1, ops
->id
);
892 if (error
== -EAGAIN
) {
893 ida_pre_get(&net_generic_ids
, GFP_KERNEL
);
898 max_gen_ptrs
= max_t(unsigned int, max_gen_ptrs
, *ops
->id
);
900 error
= __register_pernet_operations(list
, ops
);
904 ida_remove(&net_generic_ids
, *ops
->id
);
910 static void unregister_pernet_operations(struct pernet_operations
*ops
)
913 __unregister_pernet_operations(ops
);
916 ida_remove(&net_generic_ids
, *ops
->id
);
920 * register_pernet_subsys - register a network namespace subsystem
921 * @ops: pernet operations structure for the subsystem
923 * Register a subsystem which has init and exit functions
924 * that are called when network namespaces are created and
925 * destroyed respectively.
927 * When registered all network namespace init functions are
928 * called for every existing network namespace. Allowing kernel
929 * modules to have a race free view of the set of network namespaces.
931 * When a new network namespace is created all of the init
932 * methods are called in the order in which they were registered.
934 * When a network namespace is destroyed all of the exit methods
935 * are called in the reverse of the order with which they were
938 int register_pernet_subsys(struct pernet_operations
*ops
)
941 mutex_lock(&net_mutex
);
942 error
= register_pernet_operations(first_device
, ops
);
943 mutex_unlock(&net_mutex
);
946 EXPORT_SYMBOL_GPL(register_pernet_subsys
);
949 * unregister_pernet_subsys - unregister a network namespace subsystem
950 * @ops: pernet operations structure to manipulate
952 * Remove the pernet operations structure from the list to be
953 * used when network namespaces are created or destroyed. In
954 * addition run the exit method for all existing network
957 void unregister_pernet_subsys(struct pernet_operations
*ops
)
959 mutex_lock(&net_mutex
);
960 unregister_pernet_operations(ops
);
961 mutex_unlock(&net_mutex
);
963 EXPORT_SYMBOL_GPL(unregister_pernet_subsys
);
966 * register_pernet_device - register a network namespace device
967 * @ops: pernet operations structure for the subsystem
969 * Register a device which has init and exit functions
970 * that are called when network namespaces are created and
971 * destroyed respectively.
973 * When registered all network namespace init functions are
974 * called for every existing network namespace. Allowing kernel
975 * modules to have a race free view of the set of network namespaces.
977 * When a new network namespace is created all of the init
978 * methods are called in the order in which they were registered.
980 * When a network namespace is destroyed all of the exit methods
981 * are called in the reverse of the order with which they were
984 int register_pernet_device(struct pernet_operations
*ops
)
987 mutex_lock(&net_mutex
);
988 error
= register_pernet_operations(&pernet_list
, ops
);
989 if (!error
&& (first_device
== &pernet_list
))
990 first_device
= &ops
->list
;
991 mutex_unlock(&net_mutex
);
994 EXPORT_SYMBOL_GPL(register_pernet_device
);
997 * unregister_pernet_device - unregister a network namespace netdevice
998 * @ops: pernet operations structure to manipulate
1000 * Remove the pernet operations structure from the list to be
1001 * used when network namespaces are created or destroyed. In
1002 * addition run the exit method for all existing network
1005 void unregister_pernet_device(struct pernet_operations
*ops
)
1007 mutex_lock(&net_mutex
);
1008 if (&ops
->list
== first_device
)
1009 first_device
= first_device
->next
;
1010 unregister_pernet_operations(ops
);
1011 mutex_unlock(&net_mutex
);
1013 EXPORT_SYMBOL_GPL(unregister_pernet_device
);
1015 #ifdef CONFIG_NET_NS
1016 static struct ns_common
*netns_get(struct task_struct
*task
)
1018 struct net
*net
= NULL
;
1019 struct nsproxy
*nsproxy
;
1022 nsproxy
= task
->nsproxy
;
1024 net
= get_net(nsproxy
->net_ns
);
1027 return net
? &net
->ns
: NULL
;
1030 static inline struct net
*to_net_ns(struct ns_common
*ns
)
1032 return container_of(ns
, struct net
, ns
);
1035 static void netns_put(struct ns_common
*ns
)
1037 put_net(to_net_ns(ns
));
1040 static int netns_install(struct nsproxy
*nsproxy
, struct ns_common
*ns
)
1042 struct net
*net
= to_net_ns(ns
);
1044 if (!ns_capable(net
->user_ns
, CAP_SYS_ADMIN
) ||
1045 !ns_capable(current_user_ns(), CAP_SYS_ADMIN
))
1048 put_net(nsproxy
->net_ns
);
1049 nsproxy
->net_ns
= get_net(net
);
1053 static struct user_namespace
*netns_owner(struct ns_common
*ns
)
1055 return to_net_ns(ns
)->user_ns
;
1058 const struct proc_ns_operations netns_operations
= {
1060 .type
= CLONE_NEWNET
,
1063 .install
= netns_install
,
1064 .owner
= netns_owner
,