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>
19 #include <linux/sched/task.h>
22 #include <net/netlink.h>
23 #include <net/net_namespace.h>
24 #include <net/netns/generic.h>
27 * Our network namespace constructor/destructor lists
30 static LIST_HEAD(pernet_list);
31 static struct list_head *first_device = &pernet_list;
32 DEFINE_MUTEX(net_mutex);
34 LIST_HEAD(net_namespace_list);
35 EXPORT_SYMBOL_GPL(net_namespace_list);
37 struct net init_net = {
38 .count = ATOMIC_INIT(1),
39 .dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head),
41 EXPORT_SYMBOL(init_net);
43 static bool init_net_initialized;
45 #define MIN_PERNET_OPS_ID \
46 ((sizeof(struct net_generic) + sizeof(void *) - 1) / sizeof(void *))
48 #define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */
50 static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS;
52 static struct net_generic *net_alloc_generic(void)
54 struct net_generic *ng;
55 unsigned int generic_size = offsetof(struct net_generic, ptr[max_gen_ptrs]);
57 ng = kzalloc(generic_size, GFP_KERNEL);
59 ng->s.len = max_gen_ptrs;
64 static int net_assign_generic(struct net *net, unsigned int id, void *data)
66 struct net_generic *ng, *old_ng;
68 BUG_ON(!mutex_is_locked(&net_mutex));
69 BUG_ON(id < MIN_PERNET_OPS_ID);
71 old_ng = rcu_dereference_protected(net->gen,
72 lockdep_is_held(&net_mutex));
73 if (old_ng->s.len > id) {
74 old_ng->ptr[id] = data;
78 ng = net_alloc_generic();
83 * Some synchronisation notes:
85 * The net_generic explores the net->gen array inside rcu
86 * read section. Besides once set the net->gen->ptr[x]
87 * pointer never changes (see rules in netns/generic.h).
89 * That said, we simply duplicate this array and schedule
90 * the old copy for kfree after a grace period.
93 memcpy(&ng->ptr[MIN_PERNET_OPS_ID], &old_ng->ptr[MIN_PERNET_OPS_ID],
94 (old_ng->s.len - MIN_PERNET_OPS_ID) * sizeof(void *));
97 rcu_assign_pointer(net->gen, ng);
98 kfree_rcu(old_ng, s.rcu);
102 static int ops_init(const struct pernet_operations *ops, struct net *net)
107 if (ops->id && ops->size) {
108 data = kzalloc(ops->size, GFP_KERNEL);
112 err = net_assign_generic(net, *ops->id, data);
118 err = ops->init(net);
129 static void ops_free(const struct pernet_operations *ops, struct net *net)
131 if (ops->id && ops->size) {
132 kfree(net_generic(net, *ops->id));
136 static void ops_exit_list(const struct pernet_operations *ops,
137 struct list_head *net_exit_list)
141 list_for_each_entry(net, net_exit_list, exit_list)
145 ops->exit_batch(net_exit_list);
148 static void ops_free_list(const struct pernet_operations *ops,
149 struct list_head *net_exit_list)
152 if (ops->size && ops->id) {
153 list_for_each_entry(net, net_exit_list, exit_list)
158 /* should be called with nsid_lock held */
159 static int alloc_netid(struct net *net, struct net *peer, int reqid)
161 int min = 0, max = 0;
168 return idr_alloc(&net->netns_ids, peer, min, max, GFP_ATOMIC);
171 /* This function is used by idr_for_each(). If net is equal to peer, the
172 * function returns the id so that idr_for_each() stops. Because we cannot
173 * returns the id 0 (idr_for_each() will not stop), we return the magic value
174 * NET_ID_ZERO (-1) for it.
176 #define NET_ID_ZERO -1
177 static int net_eq_idr(int id, void *net, void *peer)
179 if (net_eq(net, peer))
180 return id ? : NET_ID_ZERO;
184 /* Must be called from RCU-critical section or with nsid_lock held. If
185 * a new id is assigned, the bool alloc is set to true, thus the
186 * caller knows that the new id must be notified via rtnl.
188 static int __peernet2id_alloc(struct net *net, struct net *peer, bool *alloc)
190 int id = idr_for_each(&net->netns_ids, net_eq_idr, peer);
191 bool alloc_it = *alloc;
195 /* Magic value for id 0. */
196 if (id == NET_ID_ZERO)
202 id = alloc_netid(net, peer, -1);
204 return id >= 0 ? id : NETNSA_NSID_NOT_ASSIGNED;
207 return NETNSA_NSID_NOT_ASSIGNED;
210 /* Must be called from RCU-critical section or with nsid_lock held */
211 static int __peernet2id(struct net *net, struct net *peer)
215 return __peernet2id_alloc(net, peer, &no);
218 static void rtnl_net_notifyid(struct net *net, int cmd, int id);
219 /* This function returns the id of a peer netns. If no id is assigned, one will
220 * be allocated and returned.
222 int peernet2id_alloc(struct net *net, struct net *peer)
227 if (atomic_read(&net->count) == 0)
228 return NETNSA_NSID_NOT_ASSIGNED;
229 spin_lock_bh(&net->nsid_lock);
230 alloc = atomic_read(&peer->count) == 0 ? false : true;
231 id = __peernet2id_alloc(net, peer, &alloc);
232 spin_unlock_bh(&net->nsid_lock);
233 if (alloc && id >= 0)
234 rtnl_net_notifyid(net, RTM_NEWNSID, id);
238 /* This function returns, if assigned, the id of a peer netns. */
239 int peernet2id(struct net *net, struct net *peer)
244 id = __peernet2id(net, peer);
249 EXPORT_SYMBOL(peernet2id);
251 /* This function returns true is the peer netns has an id assigned into the
254 bool peernet_has_id(struct net *net, struct net *peer)
256 return peernet2id(net, peer) >= 0;
259 struct net *get_net_ns_by_id(struct net *net, int id)
267 spin_lock_bh(&net->nsid_lock);
268 peer = idr_find(&net->netns_ids, id);
270 peer = maybe_get_net(peer);
271 spin_unlock_bh(&net->nsid_lock);
278 * setup_net runs the initializers for the network namespace object.
280 static __net_init int setup_net(struct net *net, struct user_namespace *user_ns)
282 /* Must be called with net_mutex held */
283 const struct pernet_operations *ops, *saved_ops;
285 LIST_HEAD(net_exit_list);
287 atomic_set(&net->count, 1);
288 refcount_set(&net->passive, 1);
289 get_random_bytes(&net->hash_mix, sizeof(u32));
290 net->dev_base_seq = 1;
291 net->user_ns = user_ns;
292 idr_init(&net->netns_ids);
293 spin_lock_init(&net->nsid_lock);
295 list_for_each_entry(ops, &pernet_list, list) {
296 error = ops_init(ops, net);
304 /* Walk through the list backwards calling the exit functions
305 * for the pernet modules whose init functions did not fail.
307 list_add(&net->exit_list, &net_exit_list);
309 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
310 ops_exit_list(ops, &net_exit_list);
313 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
314 ops_free_list(ops, &net_exit_list);
320 static int __net_init net_defaults_init_net(struct net *net)
322 net->core.sysctl_somaxconn = SOMAXCONN;
326 static struct pernet_operations net_defaults_ops = {
327 .init = net_defaults_init_net,
330 static __init int net_defaults_init(void)
332 if (register_pernet_subsys(&net_defaults_ops))
333 panic("Cannot initialize net default settings");
338 core_initcall(net_defaults_init);
341 static struct ucounts *inc_net_namespaces(struct user_namespace *ns)
343 return inc_ucount(ns, current_euid(), UCOUNT_NET_NAMESPACES);
346 static void dec_net_namespaces(struct ucounts *ucounts)
348 dec_ucount(ucounts, UCOUNT_NET_NAMESPACES);
351 static struct kmem_cache *net_cachep;
352 static struct workqueue_struct *netns_wq;
354 static struct net *net_alloc(void)
356 struct net *net = NULL;
357 struct net_generic *ng;
359 ng = net_alloc_generic();
363 net = kmem_cache_zalloc(net_cachep, GFP_KERNEL);
367 rcu_assign_pointer(net->gen, ng);
376 static void net_free(struct net *net)
378 kfree(rcu_access_pointer(net->gen));
379 kmem_cache_free(net_cachep, net);
382 void net_drop_ns(void *p)
385 if (ns && refcount_dec_and_test(&ns->passive))
389 struct net *copy_net_ns(unsigned long flags,
390 struct user_namespace *user_ns, struct net *old_net)
392 struct ucounts *ucounts;
396 if (!(flags & CLONE_NEWNET))
397 return get_net(old_net);
399 ucounts = inc_net_namespaces(user_ns);
401 return ERR_PTR(-ENOSPC);
405 dec_net_namespaces(ucounts);
406 return ERR_PTR(-ENOMEM);
409 get_user_ns(user_ns);
411 rv = mutex_lock_killable(&net_mutex);
414 dec_net_namespaces(ucounts);
415 put_user_ns(user_ns);
419 net->ucounts = ucounts;
420 rv = setup_net(net, user_ns);
423 list_add_tail_rcu(&net->list, &net_namespace_list);
426 mutex_unlock(&net_mutex);
428 dec_net_namespaces(ucounts);
429 put_user_ns(user_ns);
436 static DEFINE_SPINLOCK(cleanup_list_lock);
437 static LIST_HEAD(cleanup_list); /* Must hold cleanup_list_lock to touch */
439 static void cleanup_net(struct work_struct *work)
441 const struct pernet_operations *ops;
442 struct net *net, *tmp;
443 struct list_head net_kill_list;
444 LIST_HEAD(net_exit_list);
446 /* Atomically snapshot the list of namespaces to cleanup */
447 spin_lock_irq(&cleanup_list_lock);
448 list_replace_init(&cleanup_list, &net_kill_list);
449 spin_unlock_irq(&cleanup_list_lock);
451 mutex_lock(&net_mutex);
453 /* Don't let anyone else find us. */
455 list_for_each_entry(net, &net_kill_list, cleanup_list) {
456 list_del_rcu(&net->list);
457 list_add_tail(&net->exit_list, &net_exit_list);
461 spin_lock_bh(&tmp->nsid_lock);
462 id = __peernet2id(tmp, net);
464 idr_remove(&tmp->netns_ids, id);
465 spin_unlock_bh(&tmp->nsid_lock);
467 rtnl_net_notifyid(tmp, RTM_DELNSID, id);
469 spin_lock_bh(&net->nsid_lock);
470 idr_destroy(&net->netns_ids);
471 spin_unlock_bh(&net->nsid_lock);
477 * Another CPU might be rcu-iterating the list, wait for it.
478 * This needs to be before calling the exit() notifiers, so
479 * the rcu_barrier() below isn't sufficient alone.
483 /* Run all of the network namespace exit methods */
484 list_for_each_entry_reverse(ops, &pernet_list, list)
485 ops_exit_list(ops, &net_exit_list);
487 /* Free the net generic variables */
488 list_for_each_entry_reverse(ops, &pernet_list, list)
489 ops_free_list(ops, &net_exit_list);
491 mutex_unlock(&net_mutex);
493 /* Ensure there are no outstanding rcu callbacks using this
498 /* Finally it is safe to free my network namespace structure */
499 list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
500 list_del_init(&net->exit_list);
501 dec_net_namespaces(net->ucounts);
502 put_user_ns(net->user_ns);
508 * net_ns_barrier - wait until concurrent net_cleanup_work is done
510 * cleanup_net runs from work queue and will first remove namespaces
511 * from the global list, then run net exit functions.
513 * Call this in module exit path to make sure that all netns
514 * ->exit ops have been invoked before the function is removed.
516 void net_ns_barrier(void)
518 mutex_lock(&net_mutex);
519 mutex_unlock(&net_mutex);
521 EXPORT_SYMBOL(net_ns_barrier);
523 static DECLARE_WORK(net_cleanup_work, cleanup_net);
525 void __put_net(struct net *net)
527 /* Cleanup the network namespace in process context */
530 spin_lock_irqsave(&cleanup_list_lock, flags);
531 list_add(&net->cleanup_list, &cleanup_list);
532 spin_unlock_irqrestore(&cleanup_list_lock, flags);
534 queue_work(netns_wq, &net_cleanup_work);
536 EXPORT_SYMBOL_GPL(__put_net);
538 struct net *get_net_ns_by_fd(int fd)
541 struct ns_common *ns;
544 file = proc_ns_fget(fd);
546 return ERR_CAST(file);
548 ns = get_proc_ns(file_inode(file));
549 if (ns->ops == &netns_operations)
550 net = get_net(container_of(ns, struct net, ns));
552 net = ERR_PTR(-EINVAL);
559 struct net *get_net_ns_by_fd(int fd)
561 return ERR_PTR(-EINVAL);
564 EXPORT_SYMBOL_GPL(get_net_ns_by_fd);
566 struct net *get_net_ns_by_pid(pid_t pid)
568 struct task_struct *tsk;
571 /* Lookup the network namespace */
572 net = ERR_PTR(-ESRCH);
574 tsk = find_task_by_vpid(pid);
576 struct nsproxy *nsproxy;
578 nsproxy = tsk->nsproxy;
580 net = get_net(nsproxy->net_ns);
586 EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
588 static __net_init int net_ns_net_init(struct net *net)
591 net->ns.ops = &netns_operations;
593 return ns_alloc_inum(&net->ns);
596 static __net_exit void net_ns_net_exit(struct net *net)
598 ns_free_inum(&net->ns);
601 static struct pernet_operations __net_initdata net_ns_ops = {
602 .init = net_ns_net_init,
603 .exit = net_ns_net_exit,
606 static const struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = {
607 [NETNSA_NONE] = { .type = NLA_UNSPEC },
608 [NETNSA_NSID] = { .type = NLA_S32 },
609 [NETNSA_PID] = { .type = NLA_U32 },
610 [NETNSA_FD] = { .type = NLA_U32 },
613 static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh,
614 struct netlink_ext_ack *extack)
616 struct net *net = sock_net(skb->sk);
617 struct nlattr *tb[NETNSA_MAX + 1];
622 err = nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX,
623 rtnl_net_policy, extack);
626 if (!tb[NETNSA_NSID]) {
627 NL_SET_ERR_MSG(extack, "nsid is missing");
630 nsid = nla_get_s32(tb[NETNSA_NSID]);
632 if (tb[NETNSA_PID]) {
633 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
634 nla = tb[NETNSA_PID];
635 } else if (tb[NETNSA_FD]) {
636 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
639 NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
643 NL_SET_BAD_ATTR(extack, nla);
644 NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
645 return PTR_ERR(peer);
648 spin_lock_bh(&net->nsid_lock);
649 if (__peernet2id(net, peer) >= 0) {
650 spin_unlock_bh(&net->nsid_lock);
652 NL_SET_BAD_ATTR(extack, nla);
653 NL_SET_ERR_MSG(extack,
654 "Peer netns already has a nsid assigned");
658 err = alloc_netid(net, peer, nsid);
659 spin_unlock_bh(&net->nsid_lock);
661 rtnl_net_notifyid(net, RTM_NEWNSID, err);
663 } else if (err == -ENOSPC && nsid >= 0) {
665 NL_SET_BAD_ATTR(extack, tb[NETNSA_NSID]);
666 NL_SET_ERR_MSG(extack, "The specified nsid is already used");
673 static int rtnl_net_get_size(void)
675 return NLMSG_ALIGN(sizeof(struct rtgenmsg))
676 + nla_total_size(sizeof(s32)) /* NETNSA_NSID */
680 static int rtnl_net_fill(struct sk_buff *skb, u32 portid, u32 seq, int flags,
681 int cmd, struct net *net, int nsid)
683 struct nlmsghdr *nlh;
684 struct rtgenmsg *rth;
686 nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rth), flags);
690 rth = nlmsg_data(nlh);
691 rth->rtgen_family = AF_UNSPEC;
693 if (nla_put_s32(skb, NETNSA_NSID, nsid))
694 goto nla_put_failure;
700 nlmsg_cancel(skb, nlh);
704 static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh,
705 struct netlink_ext_ack *extack)
707 struct net *net = sock_net(skb->sk);
708 struct nlattr *tb[NETNSA_MAX + 1];
714 err = nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX,
715 rtnl_net_policy, extack);
718 if (tb[NETNSA_PID]) {
719 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
720 nla = tb[NETNSA_PID];
721 } else if (tb[NETNSA_FD]) {
722 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
725 NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
730 NL_SET_BAD_ATTR(extack, nla);
731 NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
732 return PTR_ERR(peer);
735 msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
741 id = peernet2id(net, peer);
742 err = rtnl_net_fill(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq, 0,
743 RTM_NEWNSID, net, id);
747 err = rtnl_unicast(msg, net, NETLINK_CB(skb).portid);
757 struct rtnl_net_dump_cb {
760 struct netlink_callback *cb;
765 /* Runs in RCU-critical section. */
766 static int rtnl_net_dumpid_one(int id, void *peer, void *data)
768 struct rtnl_net_dump_cb *net_cb = (struct rtnl_net_dump_cb *)data;
771 if (net_cb->idx < net_cb->s_idx)
774 ret = rtnl_net_fill(net_cb->skb, NETLINK_CB(net_cb->cb->skb).portid,
775 net_cb->cb->nlh->nlmsg_seq, NLM_F_MULTI,
776 RTM_NEWNSID, net_cb->net, id);
785 static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb)
787 struct net *net = sock_net(skb->sk);
788 struct rtnl_net_dump_cb net_cb = {
793 .s_idx = cb->args[0],
797 idr_for_each(&net->netns_ids, rtnl_net_dumpid_one, &net_cb);
800 cb->args[0] = net_cb.idx;
804 static void rtnl_net_notifyid(struct net *net, int cmd, int id)
809 msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
813 err = rtnl_net_fill(msg, 0, 0, 0, cmd, net, id);
817 rtnl_notify(msg, net, 0, RTNLGRP_NSID, NULL, 0);
823 rtnl_set_sk_err(net, RTNLGRP_NSID, err);
826 static int __init net_ns_init(void)
828 struct net_generic *ng;
831 net_cachep = kmem_cache_create("net_namespace", sizeof(struct net),
835 /* Create workqueue for cleanup */
836 netns_wq = create_singlethread_workqueue("netns");
838 panic("Could not create netns workq");
841 ng = net_alloc_generic();
843 panic("Could not allocate generic netns");
845 rcu_assign_pointer(init_net.gen, ng);
847 mutex_lock(&net_mutex);
848 if (setup_net(&init_net, &init_user_ns))
849 panic("Could not setup the initial network namespace");
851 init_net_initialized = true;
854 list_add_tail_rcu(&init_net.list, &net_namespace_list);
857 mutex_unlock(&net_mutex);
859 if (register_pernet_subsys(&net_ns_ops))
860 panic("Could not register network namespace subsystems");
862 rtnl_register(PF_UNSPEC, RTM_NEWNSID, rtnl_net_newid, NULL,
863 RTNL_FLAG_DOIT_UNLOCKED);
864 rtnl_register(PF_UNSPEC, RTM_GETNSID, rtnl_net_getid, rtnl_net_dumpid,
865 RTNL_FLAG_DOIT_UNLOCKED);
870 pure_initcall(net_ns_init);
873 static int __register_pernet_operations(struct list_head *list,
874 struct pernet_operations *ops)
878 LIST_HEAD(net_exit_list);
880 list_add_tail(&ops->list, list);
881 if (ops->init || (ops->id && ops->size)) {
883 error = ops_init(ops, net);
886 list_add_tail(&net->exit_list, &net_exit_list);
892 /* If I have an error cleanup all namespaces I initialized */
893 list_del(&ops->list);
894 ops_exit_list(ops, &net_exit_list);
895 ops_free_list(ops, &net_exit_list);
899 static void __unregister_pernet_operations(struct pernet_operations *ops)
902 LIST_HEAD(net_exit_list);
904 list_del(&ops->list);
906 list_add_tail(&net->exit_list, &net_exit_list);
907 ops_exit_list(ops, &net_exit_list);
908 ops_free_list(ops, &net_exit_list);
913 static int __register_pernet_operations(struct list_head *list,
914 struct pernet_operations *ops)
916 if (!init_net_initialized) {
917 list_add_tail(&ops->list, list);
921 return ops_init(ops, &init_net);
924 static void __unregister_pernet_operations(struct pernet_operations *ops)
926 if (!init_net_initialized) {
927 list_del(&ops->list);
929 LIST_HEAD(net_exit_list);
930 list_add(&init_net.exit_list, &net_exit_list);
931 ops_exit_list(ops, &net_exit_list);
932 ops_free_list(ops, &net_exit_list);
936 #endif /* CONFIG_NET_NS */
938 static DEFINE_IDA(net_generic_ids);
940 static int register_pernet_operations(struct list_head *list,
941 struct pernet_operations *ops)
947 error = ida_get_new_above(&net_generic_ids, MIN_PERNET_OPS_ID, ops->id);
949 if (error == -EAGAIN) {
950 ida_pre_get(&net_generic_ids, GFP_KERNEL);
955 max_gen_ptrs = max(max_gen_ptrs, *ops->id + 1);
957 error = __register_pernet_operations(list, ops);
961 ida_remove(&net_generic_ids, *ops->id);
967 static void unregister_pernet_operations(struct pernet_operations *ops)
970 __unregister_pernet_operations(ops);
973 ida_remove(&net_generic_ids, *ops->id);
977 * register_pernet_subsys - register a network namespace subsystem
978 * @ops: pernet operations structure for the subsystem
980 * Register a subsystem which has init and exit functions
981 * that are called when network namespaces are created and
982 * destroyed respectively.
984 * When registered all network namespace init functions are
985 * called for every existing network namespace. Allowing kernel
986 * modules to have a race free view of the set of network namespaces.
988 * When a new network namespace is created all of the init
989 * methods are called in the order in which they were registered.
991 * When a network namespace is destroyed all of the exit methods
992 * are called in the reverse of the order with which they were
995 int register_pernet_subsys(struct pernet_operations *ops)
998 mutex_lock(&net_mutex);
999 error = register_pernet_operations(first_device, ops);
1000 mutex_unlock(&net_mutex);
1003 EXPORT_SYMBOL_GPL(register_pernet_subsys);
1006 * unregister_pernet_subsys - unregister a network namespace subsystem
1007 * @ops: pernet operations structure to manipulate
1009 * Remove the pernet operations structure from the list to be
1010 * used when network namespaces are created or destroyed. In
1011 * addition run the exit method for all existing network
1014 void unregister_pernet_subsys(struct pernet_operations *ops)
1016 mutex_lock(&net_mutex);
1017 unregister_pernet_operations(ops);
1018 mutex_unlock(&net_mutex);
1020 EXPORT_SYMBOL_GPL(unregister_pernet_subsys);
1023 * register_pernet_device - register a network namespace device
1024 * @ops: pernet operations structure for the subsystem
1026 * Register a device which has init and exit functions
1027 * that are called when network namespaces are created and
1028 * destroyed respectively.
1030 * When registered all network namespace init functions are
1031 * called for every existing network namespace. Allowing kernel
1032 * modules to have a race free view of the set of network namespaces.
1034 * When a new network namespace is created all of the init
1035 * methods are called in the order in which they were registered.
1037 * When a network namespace is destroyed all of the exit methods
1038 * are called in the reverse of the order with which they were
1041 int register_pernet_device(struct pernet_operations *ops)
1044 mutex_lock(&net_mutex);
1045 error = register_pernet_operations(&pernet_list, ops);
1046 if (!error && (first_device == &pernet_list))
1047 first_device = &ops->list;
1048 mutex_unlock(&net_mutex);
1051 EXPORT_SYMBOL_GPL(register_pernet_device);
1054 * unregister_pernet_device - unregister a network namespace netdevice
1055 * @ops: pernet operations structure to manipulate
1057 * Remove the pernet operations structure from the list to be
1058 * used when network namespaces are created or destroyed. In
1059 * addition run the exit method for all existing network
1062 void unregister_pernet_device(struct pernet_operations *ops)
1064 mutex_lock(&net_mutex);
1065 if (&ops->list == first_device)
1066 first_device = first_device->next;
1067 unregister_pernet_operations(ops);
1068 mutex_unlock(&net_mutex);
1070 EXPORT_SYMBOL_GPL(unregister_pernet_device);
1072 #ifdef CONFIG_NET_NS
1073 static struct ns_common *netns_get(struct task_struct *task)
1075 struct net *net = NULL;
1076 struct nsproxy *nsproxy;
1079 nsproxy = task->nsproxy;
1081 net = get_net(nsproxy->net_ns);
1084 return net ? &net->ns : NULL;
1087 static inline struct net *to_net_ns(struct ns_common *ns)
1089 return container_of(ns, struct net, ns);
1092 static void netns_put(struct ns_common *ns)
1094 put_net(to_net_ns(ns));
1097 static int netns_install(struct nsproxy *nsproxy, struct ns_common *ns)
1099 struct net *net = to_net_ns(ns);
1101 if (!ns_capable(net->user_ns, CAP_SYS_ADMIN) ||
1102 !ns_capable(current_user_ns(), CAP_SYS_ADMIN))
1105 put_net(nsproxy->net_ns);
1106 nsproxy->net_ns = get_net(net);
1110 static struct user_namespace *netns_owner(struct ns_common *ns)
1112 return to_net_ns(ns)->user_ns;
1115 const struct proc_ns_operations netns_operations = {
1117 .type = CLONE_NEWNET,
1120 .install = netns_install,
1121 .owner = netns_owner,