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);
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);
317 static struct ucounts *inc_net_namespaces(struct user_namespace *ns)
319 return inc_ucount(ns, current_euid(), UCOUNT_NET_NAMESPACES);
322 static void dec_net_namespaces(struct ucounts *ucounts)
324 dec_ucount(ucounts, UCOUNT_NET_NAMESPACES);
327 static struct kmem_cache *net_cachep;
328 static struct workqueue_struct *netns_wq;
330 static struct net *net_alloc(void)
332 struct net *net = NULL;
333 struct net_generic *ng;
335 ng = net_alloc_generic();
339 net = kmem_cache_zalloc(net_cachep, GFP_KERNEL);
343 rcu_assign_pointer(net->gen, ng);
352 static void net_free(struct net *net)
354 kfree(rcu_access_pointer(net->gen));
355 kmem_cache_free(net_cachep, net);
358 void net_drop_ns(void *p)
361 if (ns && atomic_dec_and_test(&ns->passive))
365 struct net *copy_net_ns(unsigned long flags,
366 struct user_namespace *user_ns, struct net *old_net)
368 struct ucounts *ucounts;
372 if (!(flags & CLONE_NEWNET))
373 return get_net(old_net);
375 ucounts = inc_net_namespaces(user_ns);
377 return ERR_PTR(-ENOSPC);
381 dec_net_namespaces(ucounts);
382 return ERR_PTR(-ENOMEM);
385 get_user_ns(user_ns);
387 mutex_lock(&net_mutex);
388 net->ucounts = ucounts;
389 rv = setup_net(net, user_ns);
392 list_add_tail_rcu(&net->list, &net_namespace_list);
395 mutex_unlock(&net_mutex);
397 dec_net_namespaces(ucounts);
398 put_user_ns(user_ns);
405 static DEFINE_SPINLOCK(cleanup_list_lock);
406 static LIST_HEAD(cleanup_list); /* Must hold cleanup_list_lock to touch */
408 static void cleanup_net(struct work_struct *work)
410 const struct pernet_operations *ops;
411 struct net *net, *tmp;
412 struct list_head net_kill_list;
413 LIST_HEAD(net_exit_list);
415 /* Atomically snapshot the list of namespaces to cleanup */
416 spin_lock_irq(&cleanup_list_lock);
417 list_replace_init(&cleanup_list, &net_kill_list);
418 spin_unlock_irq(&cleanup_list_lock);
420 mutex_lock(&net_mutex);
422 /* Don't let anyone else find us. */
424 list_for_each_entry(net, &net_kill_list, cleanup_list) {
425 list_del_rcu(&net->list);
426 list_add_tail(&net->exit_list, &net_exit_list);
430 spin_lock_irq(&tmp->nsid_lock);
431 id = __peernet2id(tmp, net);
433 idr_remove(&tmp->netns_ids, id);
434 spin_unlock_irq(&tmp->nsid_lock);
436 rtnl_net_notifyid(tmp, RTM_DELNSID, id);
438 spin_lock_irq(&net->nsid_lock);
439 idr_destroy(&net->netns_ids);
440 spin_unlock_irq(&net->nsid_lock);
446 * Another CPU might be rcu-iterating the list, wait for it.
447 * This needs to be before calling the exit() notifiers, so
448 * the rcu_barrier() below isn't sufficient alone.
452 /* Run all of the network namespace exit methods */
453 list_for_each_entry_reverse(ops, &pernet_list, list)
454 ops_exit_list(ops, &net_exit_list);
456 /* Free the net generic variables */
457 list_for_each_entry_reverse(ops, &pernet_list, list)
458 ops_free_list(ops, &net_exit_list);
460 mutex_unlock(&net_mutex);
462 /* Ensure there are no outstanding rcu callbacks using this
467 /* Finally it is safe to free my network namespace structure */
468 list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
469 list_del_init(&net->exit_list);
470 dec_net_namespaces(net->ucounts);
471 put_user_ns(net->user_ns);
475 static DECLARE_WORK(net_cleanup_work, cleanup_net);
477 void __put_net(struct net *net)
479 /* Cleanup the network namespace in process context */
482 spin_lock_irqsave(&cleanup_list_lock, flags);
483 list_add(&net->cleanup_list, &cleanup_list);
484 spin_unlock_irqrestore(&cleanup_list_lock, flags);
486 queue_work(netns_wq, &net_cleanup_work);
488 EXPORT_SYMBOL_GPL(__put_net);
490 struct net *get_net_ns_by_fd(int fd)
493 struct ns_common *ns;
496 file = proc_ns_fget(fd);
498 return ERR_CAST(file);
500 ns = get_proc_ns(file_inode(file));
501 if (ns->ops == &netns_operations)
502 net = get_net(container_of(ns, struct net, ns));
504 net = ERR_PTR(-EINVAL);
511 struct net *get_net_ns_by_fd(int fd)
513 return ERR_PTR(-EINVAL);
516 EXPORT_SYMBOL_GPL(get_net_ns_by_fd);
518 struct net *get_net_ns_by_pid(pid_t pid)
520 struct task_struct *tsk;
523 /* Lookup the network namespace */
524 net = ERR_PTR(-ESRCH);
526 tsk = find_task_by_vpid(pid);
528 struct nsproxy *nsproxy;
530 nsproxy = tsk->nsproxy;
532 net = get_net(nsproxy->net_ns);
538 EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
540 static __net_init int net_ns_net_init(struct net *net)
543 net->ns.ops = &netns_operations;
545 return ns_alloc_inum(&net->ns);
548 static __net_exit void net_ns_net_exit(struct net *net)
550 ns_free_inum(&net->ns);
553 static struct pernet_operations __net_initdata net_ns_ops = {
554 .init = net_ns_net_init,
555 .exit = net_ns_net_exit,
558 static const struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = {
559 [NETNSA_NONE] = { .type = NLA_UNSPEC },
560 [NETNSA_NSID] = { .type = NLA_S32 },
561 [NETNSA_PID] = { .type = NLA_U32 },
562 [NETNSA_FD] = { .type = NLA_U32 },
565 static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh)
567 struct net *net = sock_net(skb->sk);
568 struct nlattr *tb[NETNSA_MAX + 1];
573 err = nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX,
577 if (!tb[NETNSA_NSID])
579 nsid = nla_get_s32(tb[NETNSA_NSID]);
582 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
583 else if (tb[NETNSA_FD])
584 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
588 return PTR_ERR(peer);
590 spin_lock_irqsave(&net->nsid_lock, flags);
591 if (__peernet2id(net, peer) >= 0) {
592 spin_unlock_irqrestore(&net->nsid_lock, flags);
597 err = alloc_netid(net, peer, nsid);
598 spin_unlock_irqrestore(&net->nsid_lock, flags);
600 rtnl_net_notifyid(net, RTM_NEWNSID, err);
608 static int rtnl_net_get_size(void)
610 return NLMSG_ALIGN(sizeof(struct rtgenmsg))
611 + nla_total_size(sizeof(s32)) /* NETNSA_NSID */
615 static int rtnl_net_fill(struct sk_buff *skb, u32 portid, u32 seq, int flags,
616 int cmd, struct net *net, int nsid)
618 struct nlmsghdr *nlh;
619 struct rtgenmsg *rth;
621 nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rth), flags);
625 rth = nlmsg_data(nlh);
626 rth->rtgen_family = AF_UNSPEC;
628 if (nla_put_s32(skb, NETNSA_NSID, nsid))
629 goto nla_put_failure;
635 nlmsg_cancel(skb, nlh);
639 static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh)
641 struct net *net = sock_net(skb->sk);
642 struct nlattr *tb[NETNSA_MAX + 1];
647 err = nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX,
652 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
653 else if (tb[NETNSA_FD])
654 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
659 return PTR_ERR(peer);
661 msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
667 id = peernet2id(net, peer);
668 err = rtnl_net_fill(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq, 0,
669 RTM_NEWNSID, net, id);
673 err = rtnl_unicast(msg, net, NETLINK_CB(skb).portid);
683 struct rtnl_net_dump_cb {
686 struct netlink_callback *cb;
691 static int rtnl_net_dumpid_one(int id, void *peer, void *data)
693 struct rtnl_net_dump_cb *net_cb = (struct rtnl_net_dump_cb *)data;
696 if (net_cb->idx < net_cb->s_idx)
699 ret = rtnl_net_fill(net_cb->skb, NETLINK_CB(net_cb->cb->skb).portid,
700 net_cb->cb->nlh->nlmsg_seq, NLM_F_MULTI,
701 RTM_NEWNSID, net_cb->net, id);
710 static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb)
712 struct net *net = sock_net(skb->sk);
713 struct rtnl_net_dump_cb net_cb = {
718 .s_idx = cb->args[0],
722 spin_lock_irqsave(&net->nsid_lock, flags);
723 idr_for_each(&net->netns_ids, rtnl_net_dumpid_one, &net_cb);
724 spin_unlock_irqrestore(&net->nsid_lock, flags);
726 cb->args[0] = net_cb.idx;
730 static void rtnl_net_notifyid(struct net *net, int cmd, int id)
735 msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
739 err = rtnl_net_fill(msg, 0, 0, 0, cmd, net, id);
743 rtnl_notify(msg, net, 0, RTNLGRP_NSID, NULL, 0);
749 rtnl_set_sk_err(net, RTNLGRP_NSID, err);
752 static int __init net_ns_init(void)
754 struct net_generic *ng;
757 net_cachep = kmem_cache_create("net_namespace", sizeof(struct net),
761 /* Create workqueue for cleanup */
762 netns_wq = create_singlethread_workqueue("netns");
764 panic("Could not create netns workq");
767 ng = net_alloc_generic();
769 panic("Could not allocate generic netns");
771 rcu_assign_pointer(init_net.gen, ng);
773 mutex_lock(&net_mutex);
774 if (setup_net(&init_net, &init_user_ns))
775 panic("Could not setup the initial network namespace");
777 init_net_initialized = true;
780 list_add_tail_rcu(&init_net.list, &net_namespace_list);
783 mutex_unlock(&net_mutex);
785 register_pernet_subsys(&net_ns_ops);
787 rtnl_register(PF_UNSPEC, RTM_NEWNSID, rtnl_net_newid, NULL, NULL);
788 rtnl_register(PF_UNSPEC, RTM_GETNSID, rtnl_net_getid, rtnl_net_dumpid,
794 pure_initcall(net_ns_init);
797 static int __register_pernet_operations(struct list_head *list,
798 struct pernet_operations *ops)
802 LIST_HEAD(net_exit_list);
804 list_add_tail(&ops->list, list);
805 if (ops->init || (ops->id && ops->size)) {
807 error = ops_init(ops, net);
810 list_add_tail(&net->exit_list, &net_exit_list);
816 /* If I have an error cleanup all namespaces I initialized */
817 list_del(&ops->list);
818 ops_exit_list(ops, &net_exit_list);
819 ops_free_list(ops, &net_exit_list);
823 static void __unregister_pernet_operations(struct pernet_operations *ops)
826 LIST_HEAD(net_exit_list);
828 list_del(&ops->list);
830 list_add_tail(&net->exit_list, &net_exit_list);
831 ops_exit_list(ops, &net_exit_list);
832 ops_free_list(ops, &net_exit_list);
837 static int __register_pernet_operations(struct list_head *list,
838 struct pernet_operations *ops)
840 if (!init_net_initialized) {
841 list_add_tail(&ops->list, list);
845 return ops_init(ops, &init_net);
848 static void __unregister_pernet_operations(struct pernet_operations *ops)
850 if (!init_net_initialized) {
851 list_del(&ops->list);
853 LIST_HEAD(net_exit_list);
854 list_add(&init_net.exit_list, &net_exit_list);
855 ops_exit_list(ops, &net_exit_list);
856 ops_free_list(ops, &net_exit_list);
860 #endif /* CONFIG_NET_NS */
862 static DEFINE_IDA(net_generic_ids);
864 static int register_pernet_operations(struct list_head *list,
865 struct pernet_operations *ops)
871 error = ida_get_new_above(&net_generic_ids, 1, ops->id);
873 if (error == -EAGAIN) {
874 ida_pre_get(&net_generic_ids, GFP_KERNEL);
879 max_gen_ptrs = max_t(unsigned int, max_gen_ptrs, *ops->id);
881 error = __register_pernet_operations(list, ops);
885 ida_remove(&net_generic_ids, *ops->id);
891 static void unregister_pernet_operations(struct pernet_operations *ops)
894 __unregister_pernet_operations(ops);
897 ida_remove(&net_generic_ids, *ops->id);
901 * register_pernet_subsys - register a network namespace subsystem
902 * @ops: pernet operations structure for the subsystem
904 * Register a subsystem which has init and exit functions
905 * that are called when network namespaces are created and
906 * destroyed respectively.
908 * When registered all network namespace init functions are
909 * called for every existing network namespace. Allowing kernel
910 * modules to have a race free view of the set of network namespaces.
912 * When a new network namespace is created all of the init
913 * methods are called in the order in which they were registered.
915 * When a network namespace is destroyed all of the exit methods
916 * are called in the reverse of the order with which they were
919 int register_pernet_subsys(struct pernet_operations *ops)
922 mutex_lock(&net_mutex);
923 error = register_pernet_operations(first_device, ops);
924 mutex_unlock(&net_mutex);
927 EXPORT_SYMBOL_GPL(register_pernet_subsys);
930 * unregister_pernet_subsys - unregister a network namespace subsystem
931 * @ops: pernet operations structure to manipulate
933 * Remove the pernet operations structure from the list to be
934 * used when network namespaces are created or destroyed. In
935 * addition run the exit method for all existing network
938 void unregister_pernet_subsys(struct pernet_operations *ops)
940 mutex_lock(&net_mutex);
941 unregister_pernet_operations(ops);
942 mutex_unlock(&net_mutex);
944 EXPORT_SYMBOL_GPL(unregister_pernet_subsys);
947 * register_pernet_device - register a network namespace device
948 * @ops: pernet operations structure for the subsystem
950 * Register a device which has init and exit functions
951 * that are called when network namespaces are created and
952 * destroyed respectively.
954 * When registered all network namespace init functions are
955 * called for every existing network namespace. Allowing kernel
956 * modules to have a race free view of the set of network namespaces.
958 * When a new network namespace is created all of the init
959 * methods are called in the order in which they were registered.
961 * When a network namespace is destroyed all of the exit methods
962 * are called in the reverse of the order with which they were
965 int register_pernet_device(struct pernet_operations *ops)
968 mutex_lock(&net_mutex);
969 error = register_pernet_operations(&pernet_list, ops);
970 if (!error && (first_device == &pernet_list))
971 first_device = &ops->list;
972 mutex_unlock(&net_mutex);
975 EXPORT_SYMBOL_GPL(register_pernet_device);
978 * unregister_pernet_device - unregister a network namespace netdevice
979 * @ops: pernet operations structure to manipulate
981 * Remove the pernet operations structure from the list to be
982 * used when network namespaces are created or destroyed. In
983 * addition run the exit method for all existing network
986 void unregister_pernet_device(struct pernet_operations *ops)
988 mutex_lock(&net_mutex);
989 if (&ops->list == first_device)
990 first_device = first_device->next;
991 unregister_pernet_operations(ops);
992 mutex_unlock(&net_mutex);
994 EXPORT_SYMBOL_GPL(unregister_pernet_device);
997 static struct ns_common *netns_get(struct task_struct *task)
999 struct net *net = NULL;
1000 struct nsproxy *nsproxy;
1003 nsproxy = task->nsproxy;
1005 net = get_net(nsproxy->net_ns);
1008 return net ? &net->ns : NULL;
1011 static inline struct net *to_net_ns(struct ns_common *ns)
1013 return container_of(ns, struct net, ns);
1016 static void netns_put(struct ns_common *ns)
1018 put_net(to_net_ns(ns));
1021 static int netns_install(struct nsproxy *nsproxy, struct ns_common *ns)
1023 struct net *net = to_net_ns(ns);
1025 if (!ns_capable(net->user_ns, CAP_SYS_ADMIN) ||
1026 !ns_capable(current_user_ns(), CAP_SYS_ADMIN))
1029 put_net(nsproxy->net_ns);
1030 nsproxy->net_ns = get_net(net);
1034 static struct user_namespace *netns_owner(struct ns_common *ns)
1036 return to_net_ns(ns)->user_ns;
1039 const struct proc_ns_operations netns_operations = {
1041 .type = CLONE_NEWNET,
1044 .install = netns_install,
1045 .owner = netns_owner,