1 // SPDX-License-Identifier: GPL-2.0-only
2 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
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 #include <linux/cookie.h>
25 #include <net/netlink.h>
26 #include <net/net_namespace.h>
27 #include <net/netns/generic.h>
30 * Our network namespace constructor/destructor lists
33 static LIST_HEAD(pernet_list);
34 static struct list_head *first_device = &pernet_list;
36 LIST_HEAD(net_namespace_list);
37 EXPORT_SYMBOL_GPL(net_namespace_list);
39 /* Protects net_namespace_list. Nests iside rtnl_lock() */
40 DECLARE_RWSEM(net_rwsem);
41 EXPORT_SYMBOL_GPL(net_rwsem);
44 static struct key_tag init_net_key_domain = { .usage = REFCOUNT_INIT(1) };
48 EXPORT_SYMBOL(init_net);
50 static bool init_net_initialized;
52 * pernet_ops_rwsem: protects: pernet_list, net_generic_ids,
53 * init_net_initialized and first_device pointer.
54 * This is internal net namespace object. Please, don't use it
57 DECLARE_RWSEM(pernet_ops_rwsem);
58 EXPORT_SYMBOL_GPL(pernet_ops_rwsem);
60 #define MIN_PERNET_OPS_ID \
61 ((sizeof(struct net_generic) + sizeof(void *) - 1) / sizeof(void *))
63 #define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */
65 static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS;
67 DEFINE_COOKIE(net_cookie);
69 static struct net_generic *net_alloc_generic(void)
71 struct net_generic *ng;
72 unsigned int generic_size = offsetof(struct net_generic, ptr[max_gen_ptrs]);
74 ng = kzalloc(generic_size, GFP_KERNEL);
76 ng->s.len = max_gen_ptrs;
81 static int net_assign_generic(struct net *net, unsigned int id, void *data)
83 struct net_generic *ng, *old_ng;
85 BUG_ON(id < MIN_PERNET_OPS_ID);
87 old_ng = rcu_dereference_protected(net->gen,
88 lockdep_is_held(&pernet_ops_rwsem));
89 if (old_ng->s.len > id) {
90 old_ng->ptr[id] = data;
94 ng = net_alloc_generic();
99 * Some synchronisation notes:
101 * The net_generic explores the net->gen array inside rcu
102 * read section. Besides once set the net->gen->ptr[x]
103 * pointer never changes (see rules in netns/generic.h).
105 * That said, we simply duplicate this array and schedule
106 * the old copy for kfree after a grace period.
109 memcpy(&ng->ptr[MIN_PERNET_OPS_ID], &old_ng->ptr[MIN_PERNET_OPS_ID],
110 (old_ng->s.len - MIN_PERNET_OPS_ID) * sizeof(void *));
113 rcu_assign_pointer(net->gen, ng);
114 kfree_rcu(old_ng, s.rcu);
118 static int ops_init(const struct pernet_operations *ops, struct net *net)
120 struct net_generic *ng;
124 if (ops->id && ops->size) {
125 data = kzalloc(ops->size, GFP_KERNEL);
129 err = net_assign_generic(net, *ops->id, data);
135 err = ops->init(net);
139 if (ops->id && ops->size) {
140 ng = rcu_dereference_protected(net->gen,
141 lockdep_is_held(&pernet_ops_rwsem));
142 ng->ptr[*ops->id] = NULL;
152 static void ops_pre_exit_list(const struct pernet_operations *ops,
153 struct list_head *net_exit_list)
158 list_for_each_entry(net, net_exit_list, exit_list)
163 static void ops_exit_list(const struct pernet_operations *ops,
164 struct list_head *net_exit_list)
168 list_for_each_entry(net, net_exit_list, exit_list) {
174 ops->exit_batch(net_exit_list);
177 static void ops_free_list(const struct pernet_operations *ops,
178 struct list_head *net_exit_list)
181 if (ops->size && ops->id) {
182 list_for_each_entry(net, net_exit_list, exit_list)
183 kfree(net_generic(net, *ops->id));
187 /* should be called with nsid_lock held */
188 static int alloc_netid(struct net *net, struct net *peer, int reqid)
190 int min = 0, max = 0;
197 return idr_alloc(&net->netns_ids, peer, min, max, GFP_ATOMIC);
200 /* This function is used by idr_for_each(). If net is equal to peer, the
201 * function returns the id so that idr_for_each() stops. Because we cannot
202 * returns the id 0 (idr_for_each() will not stop), we return the magic value
203 * NET_ID_ZERO (-1) for it.
205 #define NET_ID_ZERO -1
206 static int net_eq_idr(int id, void *net, void *peer)
208 if (net_eq(net, peer))
209 return id ? : NET_ID_ZERO;
213 /* Must be called from RCU-critical section or with nsid_lock held */
214 static int __peernet2id(const struct net *net, struct net *peer)
216 int id = idr_for_each(&net->netns_ids, net_eq_idr, peer);
218 /* Magic value for id 0. */
219 if (id == NET_ID_ZERO)
224 return NETNSA_NSID_NOT_ASSIGNED;
227 static void rtnl_net_notifyid(struct net *net, int cmd, int id, u32 portid,
228 struct nlmsghdr *nlh, gfp_t gfp);
229 /* This function returns the id of a peer netns. If no id is assigned, one will
230 * be allocated and returned.
232 int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp)
236 if (refcount_read(&net->ns.count) == 0)
237 return NETNSA_NSID_NOT_ASSIGNED;
239 spin_lock_bh(&net->nsid_lock);
240 id = __peernet2id(net, peer);
242 spin_unlock_bh(&net->nsid_lock);
246 /* When peer is obtained from RCU lists, we may race with
247 * its cleanup. Check whether it's alive, and this guarantees
248 * we never hash a peer back to net->netns_ids, after it has
249 * just been idr_remove()'d from there in cleanup_net().
251 if (!maybe_get_net(peer)) {
252 spin_unlock_bh(&net->nsid_lock);
253 return NETNSA_NSID_NOT_ASSIGNED;
256 id = alloc_netid(net, peer, -1);
257 spin_unlock_bh(&net->nsid_lock);
261 return NETNSA_NSID_NOT_ASSIGNED;
263 rtnl_net_notifyid(net, RTM_NEWNSID, id, 0, NULL, gfp);
267 EXPORT_SYMBOL_GPL(peernet2id_alloc);
269 /* This function returns, if assigned, the id of a peer netns. */
270 int peernet2id(const struct net *net, struct net *peer)
275 id = __peernet2id(net, peer);
280 EXPORT_SYMBOL(peernet2id);
282 /* This function returns true is the peer netns has an id assigned into the
285 bool peernet_has_id(const struct net *net, struct net *peer)
287 return peernet2id(net, peer) >= 0;
290 struct net *get_net_ns_by_id(const struct net *net, int id)
298 peer = idr_find(&net->netns_ids, id);
300 peer = maybe_get_net(peer);
307 * setup_net runs the initializers for the network namespace object.
309 static __net_init int setup_net(struct net *net, struct user_namespace *user_ns)
311 /* Must be called with pernet_ops_rwsem held */
312 const struct pernet_operations *ops, *saved_ops;
314 LIST_HEAD(net_exit_list);
316 refcount_set(&net->ns.count, 1);
317 refcount_set(&net->passive, 1);
318 get_random_bytes(&net->hash_mix, sizeof(u32));
320 net->net_cookie = gen_cookie_next(&net_cookie);
322 net->dev_base_seq = 1;
323 net->user_ns = user_ns;
324 idr_init(&net->netns_ids);
325 spin_lock_init(&net->nsid_lock);
326 mutex_init(&net->ipv4.ra_mutex);
328 list_for_each_entry(ops, &pernet_list, list) {
329 error = ops_init(ops, net);
333 down_write(&net_rwsem);
334 list_add_tail_rcu(&net->list, &net_namespace_list);
335 up_write(&net_rwsem);
340 /* Walk through the list backwards calling the exit functions
341 * for the pernet modules whose init functions did not fail.
343 list_add(&net->exit_list, &net_exit_list);
345 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
346 ops_pre_exit_list(ops, &net_exit_list);
351 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
352 ops_exit_list(ops, &net_exit_list);
355 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
356 ops_free_list(ops, &net_exit_list);
362 static int __net_init net_defaults_init_net(struct net *net)
364 net->core.sysctl_somaxconn = SOMAXCONN;
368 static struct pernet_operations net_defaults_ops = {
369 .init = net_defaults_init_net,
372 static __init int net_defaults_init(void)
374 if (register_pernet_subsys(&net_defaults_ops))
375 panic("Cannot initialize net default settings");
380 core_initcall(net_defaults_init);
383 static struct ucounts *inc_net_namespaces(struct user_namespace *ns)
385 return inc_ucount(ns, current_euid(), UCOUNT_NET_NAMESPACES);
388 static void dec_net_namespaces(struct ucounts *ucounts)
390 dec_ucount(ucounts, UCOUNT_NET_NAMESPACES);
393 static struct kmem_cache *net_cachep __ro_after_init;
394 static struct workqueue_struct *netns_wq;
396 static struct net *net_alloc(void)
398 struct net *net = NULL;
399 struct net_generic *ng;
401 ng = net_alloc_generic();
405 net = kmem_cache_zalloc(net_cachep, GFP_KERNEL);
410 net->key_domain = kzalloc(sizeof(struct key_tag), GFP_KERNEL);
411 if (!net->key_domain)
413 refcount_set(&net->key_domain->usage, 1);
416 rcu_assign_pointer(net->gen, ng);
422 kmem_cache_free(net_cachep, net);
430 static void net_free(struct net *net)
432 if (refcount_dec_and_test(&net->passive)) {
433 kfree(rcu_access_pointer(net->gen));
434 kmem_cache_free(net_cachep, net);
438 void net_drop_ns(void *p)
440 struct net *net = (struct net *)p;
446 struct net *copy_net_ns(unsigned long flags,
447 struct user_namespace *user_ns, struct net *old_net)
449 struct ucounts *ucounts;
453 if (!(flags & CLONE_NEWNET))
454 return get_net(old_net);
456 ucounts = inc_net_namespaces(user_ns);
458 return ERR_PTR(-ENOSPC);
465 refcount_set(&net->passive, 1);
466 net->ucounts = ucounts;
467 get_user_ns(user_ns);
469 rv = down_read_killable(&pernet_ops_rwsem);
473 rv = setup_net(net, user_ns);
475 up_read(&pernet_ops_rwsem);
480 key_remove_domain(net->key_domain);
482 put_user_ns(user_ns);
485 dec_net_namespaces(ucounts);
492 * net_ns_get_ownership - get sysfs ownership data for @net
493 * @net: network namespace in question (can be NULL)
494 * @uid: kernel user ID for sysfs objects
495 * @gid: kernel group ID for sysfs objects
497 * Returns the uid/gid pair of root in the user namespace associated with the
498 * given network namespace.
500 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid)
503 kuid_t ns_root_uid = make_kuid(net->user_ns, 0);
504 kgid_t ns_root_gid = make_kgid(net->user_ns, 0);
506 if (uid_valid(ns_root_uid))
509 if (gid_valid(ns_root_gid))
512 *uid = GLOBAL_ROOT_UID;
513 *gid = GLOBAL_ROOT_GID;
516 EXPORT_SYMBOL_GPL(net_ns_get_ownership);
518 static void unhash_nsid(struct net *net, struct net *last)
521 /* This function is only called from cleanup_net() work,
522 * and this work is the only process, that may delete
523 * a net from net_namespace_list. So, when the below
524 * is executing, the list may only grow. Thus, we do not
525 * use for_each_net_rcu() or net_rwsem.
530 spin_lock_bh(&tmp->nsid_lock);
531 id = __peernet2id(tmp, net);
533 idr_remove(&tmp->netns_ids, id);
534 spin_unlock_bh(&tmp->nsid_lock);
536 rtnl_net_notifyid(tmp, RTM_DELNSID, id, 0, NULL,
541 spin_lock_bh(&net->nsid_lock);
542 idr_destroy(&net->netns_ids);
543 spin_unlock_bh(&net->nsid_lock);
546 static LLIST_HEAD(cleanup_list);
548 static void cleanup_net(struct work_struct *work)
550 const struct pernet_operations *ops;
551 struct net *net, *tmp, *last;
552 struct llist_node *net_kill_list;
553 LIST_HEAD(net_exit_list);
555 /* Atomically snapshot the list of namespaces to cleanup */
556 net_kill_list = llist_del_all(&cleanup_list);
558 down_read(&pernet_ops_rwsem);
560 /* Don't let anyone else find us. */
561 down_write(&net_rwsem);
562 llist_for_each_entry(net, net_kill_list, cleanup_list)
563 list_del_rcu(&net->list);
564 /* Cache last net. After we unlock rtnl, no one new net
565 * added to net_namespace_list can assign nsid pointer
566 * to a net from net_kill_list (see peernet2id_alloc()).
567 * So, we skip them in unhash_nsid().
569 * Note, that unhash_nsid() does not delete nsid links
570 * between net_kill_list's nets, as they've already
571 * deleted from net_namespace_list. But, this would be
572 * useless anyway, as netns_ids are destroyed there.
574 last = list_last_entry(&net_namespace_list, struct net, list);
575 up_write(&net_rwsem);
577 llist_for_each_entry(net, net_kill_list, cleanup_list) {
578 unhash_nsid(net, last);
579 list_add_tail(&net->exit_list, &net_exit_list);
582 /* Run all of the network namespace pre_exit methods */
583 list_for_each_entry_reverse(ops, &pernet_list, list)
584 ops_pre_exit_list(ops, &net_exit_list);
587 * Another CPU might be rcu-iterating the list, wait for it.
588 * This needs to be before calling the exit() notifiers, so
589 * the rcu_barrier() below isn't sufficient alone.
590 * Also the pre_exit() and exit() methods need this barrier.
594 /* Run all of the network namespace exit methods */
595 list_for_each_entry_reverse(ops, &pernet_list, list)
596 ops_exit_list(ops, &net_exit_list);
598 /* Free the net generic variables */
599 list_for_each_entry_reverse(ops, &pernet_list, list)
600 ops_free_list(ops, &net_exit_list);
602 up_read(&pernet_ops_rwsem);
604 /* Ensure there are no outstanding rcu callbacks using this
609 /* Finally it is safe to free my network namespace structure */
610 list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
611 list_del_init(&net->exit_list);
612 dec_net_namespaces(net->ucounts);
614 key_remove_domain(net->key_domain);
616 put_user_ns(net->user_ns);
622 * net_ns_barrier - wait until concurrent net_cleanup_work is done
624 * cleanup_net runs from work queue and will first remove namespaces
625 * from the global list, then run net exit functions.
627 * Call this in module exit path to make sure that all netns
628 * ->exit ops have been invoked before the function is removed.
630 void net_ns_barrier(void)
632 down_write(&pernet_ops_rwsem);
633 up_write(&pernet_ops_rwsem);
635 EXPORT_SYMBOL(net_ns_barrier);
637 static DECLARE_WORK(net_cleanup_work, cleanup_net);
639 void __put_net(struct net *net)
641 /* Cleanup the network namespace in process context */
642 if (llist_add(&net->cleanup_list, &cleanup_list))
643 queue_work(netns_wq, &net_cleanup_work);
645 EXPORT_SYMBOL_GPL(__put_net);
648 * get_net_ns - increment the refcount of the network namespace
649 * @ns: common namespace (net)
651 * Returns the net's common namespace.
653 struct ns_common *get_net_ns(struct ns_common *ns)
655 return &get_net(container_of(ns, struct net, ns))->ns;
657 EXPORT_SYMBOL_GPL(get_net_ns);
659 struct net *get_net_ns_by_fd(int fd)
662 struct ns_common *ns;
665 file = proc_ns_fget(fd);
667 return ERR_CAST(file);
669 ns = get_proc_ns(file_inode(file));
670 if (ns->ops == &netns_operations)
671 net = get_net(container_of(ns, struct net, ns));
673 net = ERR_PTR(-EINVAL);
678 EXPORT_SYMBOL_GPL(get_net_ns_by_fd);
681 struct net *get_net_ns_by_pid(pid_t pid)
683 struct task_struct *tsk;
686 /* Lookup the network namespace */
687 net = ERR_PTR(-ESRCH);
689 tsk = find_task_by_vpid(pid);
691 struct nsproxy *nsproxy;
693 nsproxy = tsk->nsproxy;
695 net = get_net(nsproxy->net_ns);
701 EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
703 static __net_init int net_ns_net_init(struct net *net)
706 net->ns.ops = &netns_operations;
708 return ns_alloc_inum(&net->ns);
711 static __net_exit void net_ns_net_exit(struct net *net)
713 ns_free_inum(&net->ns);
716 static struct pernet_operations __net_initdata net_ns_ops = {
717 .init = net_ns_net_init,
718 .exit = net_ns_net_exit,
721 static const struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = {
722 [NETNSA_NONE] = { .type = NLA_UNSPEC },
723 [NETNSA_NSID] = { .type = NLA_S32 },
724 [NETNSA_PID] = { .type = NLA_U32 },
725 [NETNSA_FD] = { .type = NLA_U32 },
726 [NETNSA_TARGET_NSID] = { .type = NLA_S32 },
729 static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh,
730 struct netlink_ext_ack *extack)
732 struct net *net = sock_net(skb->sk);
733 struct nlattr *tb[NETNSA_MAX + 1];
738 err = nlmsg_parse_deprecated(nlh, sizeof(struct rtgenmsg), tb,
739 NETNSA_MAX, rtnl_net_policy, extack);
742 if (!tb[NETNSA_NSID]) {
743 NL_SET_ERR_MSG(extack, "nsid is missing");
746 nsid = nla_get_s32(tb[NETNSA_NSID]);
748 if (tb[NETNSA_PID]) {
749 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
750 nla = tb[NETNSA_PID];
751 } else if (tb[NETNSA_FD]) {
752 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
755 NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
759 NL_SET_BAD_ATTR(extack, nla);
760 NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
761 return PTR_ERR(peer);
764 spin_lock_bh(&net->nsid_lock);
765 if (__peernet2id(net, peer) >= 0) {
766 spin_unlock_bh(&net->nsid_lock);
768 NL_SET_BAD_ATTR(extack, nla);
769 NL_SET_ERR_MSG(extack,
770 "Peer netns already has a nsid assigned");
774 err = alloc_netid(net, peer, nsid);
775 spin_unlock_bh(&net->nsid_lock);
777 rtnl_net_notifyid(net, RTM_NEWNSID, err, NETLINK_CB(skb).portid,
780 } else if (err == -ENOSPC && nsid >= 0) {
782 NL_SET_BAD_ATTR(extack, tb[NETNSA_NSID]);
783 NL_SET_ERR_MSG(extack, "The specified nsid is already used");
790 static int rtnl_net_get_size(void)
792 return NLMSG_ALIGN(sizeof(struct rtgenmsg))
793 + nla_total_size(sizeof(s32)) /* NETNSA_NSID */
794 + nla_total_size(sizeof(s32)) /* NETNSA_CURRENT_NSID */
798 struct net_fill_args {
808 static int rtnl_net_fill(struct sk_buff *skb, struct net_fill_args *args)
810 struct nlmsghdr *nlh;
811 struct rtgenmsg *rth;
813 nlh = nlmsg_put(skb, args->portid, args->seq, args->cmd, sizeof(*rth),
818 rth = nlmsg_data(nlh);
819 rth->rtgen_family = AF_UNSPEC;
821 if (nla_put_s32(skb, NETNSA_NSID, args->nsid))
822 goto nla_put_failure;
825 nla_put_s32(skb, NETNSA_CURRENT_NSID, args->ref_nsid))
826 goto nla_put_failure;
832 nlmsg_cancel(skb, nlh);
836 static int rtnl_net_valid_getid_req(struct sk_buff *skb,
837 const struct nlmsghdr *nlh,
839 struct netlink_ext_ack *extack)
843 if (!netlink_strict_get_check(skb))
844 return nlmsg_parse_deprecated(nlh, sizeof(struct rtgenmsg),
845 tb, NETNSA_MAX, rtnl_net_policy,
848 err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct rtgenmsg), tb,
849 NETNSA_MAX, rtnl_net_policy,
854 for (i = 0; i <= NETNSA_MAX; i++) {
862 case NETNSA_TARGET_NSID:
865 NL_SET_ERR_MSG(extack, "Unsupported attribute in peer netns getid request");
873 static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh,
874 struct netlink_ext_ack *extack)
876 struct net *net = sock_net(skb->sk);
877 struct nlattr *tb[NETNSA_MAX + 1];
878 struct net_fill_args fillargs = {
879 .portid = NETLINK_CB(skb).portid,
880 .seq = nlh->nlmsg_seq,
883 struct net *peer, *target = net;
888 err = rtnl_net_valid_getid_req(skb, nlh, tb, extack);
891 if (tb[NETNSA_PID]) {
892 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
893 nla = tb[NETNSA_PID];
894 } else if (tb[NETNSA_FD]) {
895 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
897 } else if (tb[NETNSA_NSID]) {
898 peer = get_net_ns_by_id(net, nla_get_s32(tb[NETNSA_NSID]));
900 peer = ERR_PTR(-ENOENT);
901 nla = tb[NETNSA_NSID];
903 NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
908 NL_SET_BAD_ATTR(extack, nla);
909 NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
910 return PTR_ERR(peer);
913 if (tb[NETNSA_TARGET_NSID]) {
914 int id = nla_get_s32(tb[NETNSA_TARGET_NSID]);
916 target = rtnl_get_net_ns_capable(NETLINK_CB(skb).sk, id);
917 if (IS_ERR(target)) {
918 NL_SET_BAD_ATTR(extack, tb[NETNSA_TARGET_NSID]);
919 NL_SET_ERR_MSG(extack,
920 "Target netns reference is invalid");
921 err = PTR_ERR(target);
924 fillargs.add_ref = true;
925 fillargs.ref_nsid = peernet2id(net, peer);
928 msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
934 fillargs.nsid = peernet2id(target, peer);
935 err = rtnl_net_fill(msg, &fillargs);
939 err = rtnl_unicast(msg, net, NETLINK_CB(skb).portid);
945 if (fillargs.add_ref)
951 struct rtnl_net_dump_cb {
955 struct net_fill_args fillargs;
960 /* Runs in RCU-critical section. */
961 static int rtnl_net_dumpid_one(int id, void *peer, void *data)
963 struct rtnl_net_dump_cb *net_cb = (struct rtnl_net_dump_cb *)data;
966 if (net_cb->idx < net_cb->s_idx)
969 net_cb->fillargs.nsid = id;
970 if (net_cb->fillargs.add_ref)
971 net_cb->fillargs.ref_nsid = __peernet2id(net_cb->ref_net, peer);
972 ret = rtnl_net_fill(net_cb->skb, &net_cb->fillargs);
981 static int rtnl_valid_dump_net_req(const struct nlmsghdr *nlh, struct sock *sk,
982 struct rtnl_net_dump_cb *net_cb,
983 struct netlink_callback *cb)
985 struct netlink_ext_ack *extack = cb->extack;
986 struct nlattr *tb[NETNSA_MAX + 1];
989 err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct rtgenmsg), tb,
990 NETNSA_MAX, rtnl_net_policy,
995 for (i = 0; i <= NETNSA_MAX; i++) {
999 if (i == NETNSA_TARGET_NSID) {
1002 net = rtnl_get_net_ns_capable(sk, nla_get_s32(tb[i]));
1004 NL_SET_BAD_ATTR(extack, tb[i]);
1005 NL_SET_ERR_MSG(extack,
1006 "Invalid target network namespace id");
1007 return PTR_ERR(net);
1009 net_cb->fillargs.add_ref = true;
1010 net_cb->ref_net = net_cb->tgt_net;
1011 net_cb->tgt_net = net;
1013 NL_SET_BAD_ATTR(extack, tb[i]);
1014 NL_SET_ERR_MSG(extack,
1015 "Unsupported attribute in dump request");
1023 static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb)
1025 struct rtnl_net_dump_cb net_cb = {
1026 .tgt_net = sock_net(skb->sk),
1029 .portid = NETLINK_CB(cb->skb).portid,
1030 .seq = cb->nlh->nlmsg_seq,
1031 .flags = NLM_F_MULTI,
1035 .s_idx = cb->args[0],
1039 if (cb->strict_check) {
1040 err = rtnl_valid_dump_net_req(cb->nlh, skb->sk, &net_cb, cb);
1046 idr_for_each(&net_cb.tgt_net->netns_ids, rtnl_net_dumpid_one, &net_cb);
1049 cb->args[0] = net_cb.idx;
1051 if (net_cb.fillargs.add_ref)
1052 put_net(net_cb.tgt_net);
1053 return err < 0 ? err : skb->len;
1056 static void rtnl_net_notifyid(struct net *net, int cmd, int id, u32 portid,
1057 struct nlmsghdr *nlh, gfp_t gfp)
1059 struct net_fill_args fillargs = {
1061 .seq = nlh ? nlh->nlmsg_seq : 0,
1065 struct sk_buff *msg;
1068 msg = nlmsg_new(rtnl_net_get_size(), gfp);
1072 err = rtnl_net_fill(msg, &fillargs);
1076 rtnl_notify(msg, net, portid, RTNLGRP_NSID, nlh, gfp);
1082 rtnl_set_sk_err(net, RTNLGRP_NSID, err);
1085 void __init net_ns_init(void)
1087 struct net_generic *ng;
1089 #ifdef CONFIG_NET_NS
1090 net_cachep = kmem_cache_create("net_namespace", sizeof(struct net),
1092 SLAB_PANIC|SLAB_ACCOUNT, NULL);
1094 /* Create workqueue for cleanup */
1095 netns_wq = create_singlethread_workqueue("netns");
1097 panic("Could not create netns workq");
1100 ng = net_alloc_generic();
1102 panic("Could not allocate generic netns");
1104 rcu_assign_pointer(init_net.gen, ng);
1107 init_net.key_domain = &init_net_key_domain;
1109 down_write(&pernet_ops_rwsem);
1110 if (setup_net(&init_net, &init_user_ns))
1111 panic("Could not setup the initial network namespace");
1113 init_net_initialized = true;
1114 up_write(&pernet_ops_rwsem);
1116 if (register_pernet_subsys(&net_ns_ops))
1117 panic("Could not register network namespace subsystems");
1119 rtnl_register(PF_UNSPEC, RTM_NEWNSID, rtnl_net_newid, NULL,
1120 RTNL_FLAG_DOIT_UNLOCKED);
1121 rtnl_register(PF_UNSPEC, RTM_GETNSID, rtnl_net_getid, rtnl_net_dumpid,
1122 RTNL_FLAG_DOIT_UNLOCKED);
1125 static void free_exit_list(struct pernet_operations *ops, struct list_head *net_exit_list)
1127 ops_pre_exit_list(ops, net_exit_list);
1129 ops_exit_list(ops, net_exit_list);
1130 ops_free_list(ops, net_exit_list);
1133 #ifdef CONFIG_NET_NS
1134 static int __register_pernet_operations(struct list_head *list,
1135 struct pernet_operations *ops)
1139 LIST_HEAD(net_exit_list);
1141 list_add_tail(&ops->list, list);
1142 if (ops->init || (ops->id && ops->size)) {
1143 /* We held write locked pernet_ops_rwsem, and parallel
1144 * setup_net() and cleanup_net() are not possible.
1147 error = ops_init(ops, net);
1150 list_add_tail(&net->exit_list, &net_exit_list);
1156 /* If I have an error cleanup all namespaces I initialized */
1157 list_del(&ops->list);
1158 free_exit_list(ops, &net_exit_list);
1162 static void __unregister_pernet_operations(struct pernet_operations *ops)
1165 LIST_HEAD(net_exit_list);
1167 list_del(&ops->list);
1168 /* See comment in __register_pernet_operations() */
1170 list_add_tail(&net->exit_list, &net_exit_list);
1172 free_exit_list(ops, &net_exit_list);
1177 static int __register_pernet_operations(struct list_head *list,
1178 struct pernet_operations *ops)
1180 if (!init_net_initialized) {
1181 list_add_tail(&ops->list, list);
1185 return ops_init(ops, &init_net);
1188 static void __unregister_pernet_operations(struct pernet_operations *ops)
1190 if (!init_net_initialized) {
1191 list_del(&ops->list);
1193 LIST_HEAD(net_exit_list);
1194 list_add(&init_net.exit_list, &net_exit_list);
1195 free_exit_list(ops, &net_exit_list);
1199 #endif /* CONFIG_NET_NS */
1201 static DEFINE_IDA(net_generic_ids);
1203 static int register_pernet_operations(struct list_head *list,
1204 struct pernet_operations *ops)
1209 error = ida_alloc_min(&net_generic_ids, MIN_PERNET_OPS_ID,
1214 max_gen_ptrs = max(max_gen_ptrs, *ops->id + 1);
1216 error = __register_pernet_operations(list, ops);
1220 ida_free(&net_generic_ids, *ops->id);
1226 static void unregister_pernet_operations(struct pernet_operations *ops)
1228 __unregister_pernet_operations(ops);
1231 ida_free(&net_generic_ids, *ops->id);
1235 * register_pernet_subsys - register a network namespace subsystem
1236 * @ops: pernet operations structure for the subsystem
1238 * Register a subsystem which has init and exit functions
1239 * that are called when network namespaces are created and
1240 * destroyed respectively.
1242 * When registered all network namespace init functions are
1243 * called for every existing network namespace. Allowing kernel
1244 * modules to have a race free view of the set of network namespaces.
1246 * When a new network namespace is created all of the init
1247 * methods are called in the order in which they were registered.
1249 * When a network namespace is destroyed all of the exit methods
1250 * are called in the reverse of the order with which they were
1253 int register_pernet_subsys(struct pernet_operations *ops)
1256 down_write(&pernet_ops_rwsem);
1257 error = register_pernet_operations(first_device, ops);
1258 up_write(&pernet_ops_rwsem);
1261 EXPORT_SYMBOL_GPL(register_pernet_subsys);
1264 * unregister_pernet_subsys - unregister a network namespace subsystem
1265 * @ops: pernet operations structure to manipulate
1267 * Remove the pernet operations structure from the list to be
1268 * used when network namespaces are created or destroyed. In
1269 * addition run the exit method for all existing network
1272 void unregister_pernet_subsys(struct pernet_operations *ops)
1274 down_write(&pernet_ops_rwsem);
1275 unregister_pernet_operations(ops);
1276 up_write(&pernet_ops_rwsem);
1278 EXPORT_SYMBOL_GPL(unregister_pernet_subsys);
1281 * register_pernet_device - register a network namespace device
1282 * @ops: pernet operations structure for the subsystem
1284 * Register a device which has init and exit functions
1285 * that are called when network namespaces are created and
1286 * destroyed respectively.
1288 * When registered all network namespace init functions are
1289 * called for every existing network namespace. Allowing kernel
1290 * modules to have a race free view of the set of network namespaces.
1292 * When a new network namespace is created all of the init
1293 * methods are called in the order in which they were registered.
1295 * When a network namespace is destroyed all of the exit methods
1296 * are called in the reverse of the order with which they were
1299 int register_pernet_device(struct pernet_operations *ops)
1302 down_write(&pernet_ops_rwsem);
1303 error = register_pernet_operations(&pernet_list, ops);
1304 if (!error && (first_device == &pernet_list))
1305 first_device = &ops->list;
1306 up_write(&pernet_ops_rwsem);
1309 EXPORT_SYMBOL_GPL(register_pernet_device);
1312 * unregister_pernet_device - unregister a network namespace netdevice
1313 * @ops: pernet operations structure to manipulate
1315 * Remove the pernet operations structure from the list to be
1316 * used when network namespaces are created or destroyed. In
1317 * addition run the exit method for all existing network
1320 void unregister_pernet_device(struct pernet_operations *ops)
1322 down_write(&pernet_ops_rwsem);
1323 if (&ops->list == first_device)
1324 first_device = first_device->next;
1325 unregister_pernet_operations(ops);
1326 up_write(&pernet_ops_rwsem);
1328 EXPORT_SYMBOL_GPL(unregister_pernet_device);
1330 #ifdef CONFIG_NET_NS
1331 static struct ns_common *netns_get(struct task_struct *task)
1333 struct net *net = NULL;
1334 struct nsproxy *nsproxy;
1337 nsproxy = task->nsproxy;
1339 net = get_net(nsproxy->net_ns);
1342 return net ? &net->ns : NULL;
1345 static inline struct net *to_net_ns(struct ns_common *ns)
1347 return container_of(ns, struct net, ns);
1350 static void netns_put(struct ns_common *ns)
1352 put_net(to_net_ns(ns));
1355 static int netns_install(struct nsset *nsset, struct ns_common *ns)
1357 struct nsproxy *nsproxy = nsset->nsproxy;
1358 struct net *net = to_net_ns(ns);
1360 if (!ns_capable(net->user_ns, CAP_SYS_ADMIN) ||
1361 !ns_capable(nsset->cred->user_ns, CAP_SYS_ADMIN))
1364 put_net(nsproxy->net_ns);
1365 nsproxy->net_ns = get_net(net);
1369 static struct user_namespace *netns_owner(struct ns_common *ns)
1371 return to_net_ns(ns)->user_ns;
1374 const struct proc_ns_operations netns_operations = {
1376 .type = CLONE_NEWNET,
1379 .install = netns_install,
1380 .owner = netns_owner,