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>
24 #include <net/netlink.h>
25 #include <net/net_namespace.h>
26 #include <net/netns/generic.h>
29 * Our network namespace constructor/destructor lists
32 static LIST_HEAD(pernet_list);
33 static struct list_head *first_device = &pernet_list;
35 LIST_HEAD(net_namespace_list);
36 EXPORT_SYMBOL_GPL(net_namespace_list);
38 /* Protects net_namespace_list. Nests iside rtnl_lock() */
39 DECLARE_RWSEM(net_rwsem);
40 EXPORT_SYMBOL_GPL(net_rwsem);
42 struct net init_net = {
43 .count = REFCOUNT_INIT(1),
44 .dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head),
46 EXPORT_SYMBOL(init_net);
48 static bool init_net_initialized;
50 * pernet_ops_rwsem: protects: pernet_list, net_generic_ids,
51 * init_net_initialized and first_device pointer.
52 * This is internal net namespace object. Please, don't use it
55 DECLARE_RWSEM(pernet_ops_rwsem);
56 EXPORT_SYMBOL_GPL(pernet_ops_rwsem);
58 #define MIN_PERNET_OPS_ID \
59 ((sizeof(struct net_generic) + sizeof(void *) - 1) / sizeof(void *))
61 #define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */
63 static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS;
65 static struct net_generic *net_alloc_generic(void)
67 struct net_generic *ng;
68 unsigned int generic_size = offsetof(struct net_generic, ptr[max_gen_ptrs]);
70 ng = kzalloc(generic_size, GFP_KERNEL);
72 ng->s.len = max_gen_ptrs;
77 static int net_assign_generic(struct net *net, unsigned int id, void *data)
79 struct net_generic *ng, *old_ng;
81 BUG_ON(id < MIN_PERNET_OPS_ID);
83 old_ng = rcu_dereference_protected(net->gen,
84 lockdep_is_held(&pernet_ops_rwsem));
85 if (old_ng->s.len > id) {
86 old_ng->ptr[id] = data;
90 ng = net_alloc_generic();
95 * Some synchronisation notes:
97 * The net_generic explores the net->gen array inside rcu
98 * read section. Besides once set the net->gen->ptr[x]
99 * pointer never changes (see rules in netns/generic.h).
101 * That said, we simply duplicate this array and schedule
102 * the old copy for kfree after a grace period.
105 memcpy(&ng->ptr[MIN_PERNET_OPS_ID], &old_ng->ptr[MIN_PERNET_OPS_ID],
106 (old_ng->s.len - MIN_PERNET_OPS_ID) * sizeof(void *));
109 rcu_assign_pointer(net->gen, ng);
110 kfree_rcu(old_ng, s.rcu);
114 static int ops_init(const struct pernet_operations *ops, struct net *net)
119 if (ops->id && ops->size) {
120 data = kzalloc(ops->size, GFP_KERNEL);
124 err = net_assign_generic(net, *ops->id, data);
130 err = ops->init(net);
141 static void ops_free(const struct pernet_operations *ops, struct net *net)
143 if (ops->id && ops->size) {
144 kfree(net_generic(net, *ops->id));
148 static void ops_exit_list(const struct pernet_operations *ops,
149 struct list_head *net_exit_list)
153 list_for_each_entry(net, net_exit_list, exit_list)
157 ops->exit_batch(net_exit_list);
160 static void ops_free_list(const struct pernet_operations *ops,
161 struct list_head *net_exit_list)
164 if (ops->size && ops->id) {
165 list_for_each_entry(net, net_exit_list, exit_list)
170 /* should be called with nsid_lock held */
171 static int alloc_netid(struct net *net, struct net *peer, int reqid)
173 int min = 0, max = 0;
180 return idr_alloc(&net->netns_ids, peer, min, max, GFP_ATOMIC);
183 /* This function is used by idr_for_each(). If net is equal to peer, the
184 * function returns the id so that idr_for_each() stops. Because we cannot
185 * returns the id 0 (idr_for_each() will not stop), we return the magic value
186 * NET_ID_ZERO (-1) for it.
188 #define NET_ID_ZERO -1
189 static int net_eq_idr(int id, void *net, void *peer)
191 if (net_eq(net, peer))
192 return id ? : NET_ID_ZERO;
196 /* Should be called with nsid_lock held. If a new id is assigned, the bool alloc
197 * is set to true, thus the caller knows that the new id must be notified via
200 static int __peernet2id_alloc(struct net *net, struct net *peer, bool *alloc)
202 int id = idr_for_each(&net->netns_ids, net_eq_idr, peer);
203 bool alloc_it = *alloc;
207 /* Magic value for id 0. */
208 if (id == NET_ID_ZERO)
214 id = alloc_netid(net, peer, -1);
216 return id >= 0 ? id : NETNSA_NSID_NOT_ASSIGNED;
219 return NETNSA_NSID_NOT_ASSIGNED;
222 /* should be called with nsid_lock held */
223 static int __peernet2id(struct net *net, struct net *peer)
227 return __peernet2id_alloc(net, peer, &no);
230 static void rtnl_net_notifyid(struct net *net, int cmd, int id);
231 /* This function returns the id of a peer netns. If no id is assigned, one will
232 * be allocated and returned.
234 int peernet2id_alloc(struct net *net, struct net *peer)
236 bool alloc = false, alive = false;
239 if (refcount_read(&net->count) == 0)
240 return NETNSA_NSID_NOT_ASSIGNED;
241 spin_lock_bh(&net->nsid_lock);
243 * When peer is obtained from RCU lists, we may race with
244 * its cleanup. Check whether it's alive, and this guarantees
245 * we never hash a peer back to net->netns_ids, after it has
246 * just been idr_remove()'d from there in cleanup_net().
248 if (maybe_get_net(peer))
249 alive = alloc = true;
250 id = __peernet2id_alloc(net, peer, &alloc);
251 spin_unlock_bh(&net->nsid_lock);
252 if (alloc && id >= 0)
253 rtnl_net_notifyid(net, RTM_NEWNSID, id);
258 EXPORT_SYMBOL_GPL(peernet2id_alloc);
260 /* This function returns, if assigned, the id of a peer netns. */
261 int peernet2id(struct net *net, struct net *peer)
265 spin_lock_bh(&net->nsid_lock);
266 id = __peernet2id(net, peer);
267 spin_unlock_bh(&net->nsid_lock);
270 EXPORT_SYMBOL(peernet2id);
272 /* This function returns true is the peer netns has an id assigned into the
275 bool peernet_has_id(struct net *net, struct net *peer)
277 return peernet2id(net, peer) >= 0;
280 struct net *get_net_ns_by_id(struct net *net, int id)
288 peer = idr_find(&net->netns_ids, id);
290 peer = maybe_get_net(peer);
297 * setup_net runs the initializers for the network namespace object.
299 static __net_init int setup_net(struct net *net, struct user_namespace *user_ns)
301 /* Must be called with pernet_ops_rwsem held */
302 const struct pernet_operations *ops, *saved_ops;
304 LIST_HEAD(net_exit_list);
306 refcount_set(&net->count, 1);
307 refcount_set(&net->passive, 1);
308 get_random_bytes(&net->hash_mix, sizeof(u32));
309 net->dev_base_seq = 1;
310 net->user_ns = user_ns;
311 idr_init(&net->netns_ids);
312 spin_lock_init(&net->nsid_lock);
313 mutex_init(&net->ipv4.ra_mutex);
315 list_for_each_entry(ops, &pernet_list, list) {
316 error = ops_init(ops, net);
320 down_write(&net_rwsem);
321 list_add_tail_rcu(&net->list, &net_namespace_list);
322 up_write(&net_rwsem);
327 /* Walk through the list backwards calling the exit functions
328 * for the pernet modules whose init functions did not fail.
330 list_add(&net->exit_list, &net_exit_list);
332 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
333 ops_exit_list(ops, &net_exit_list);
336 list_for_each_entry_continue_reverse(ops, &pernet_list, list)
337 ops_free_list(ops, &net_exit_list);
343 static int __net_init net_defaults_init_net(struct net *net)
345 net->core.sysctl_somaxconn = SOMAXCONN;
349 static struct pernet_operations net_defaults_ops = {
350 .init = net_defaults_init_net,
353 static __init int net_defaults_init(void)
355 if (register_pernet_subsys(&net_defaults_ops))
356 panic("Cannot initialize net default settings");
361 core_initcall(net_defaults_init);
364 static struct ucounts *inc_net_namespaces(struct user_namespace *ns)
366 return inc_ucount(ns, current_euid(), UCOUNT_NET_NAMESPACES);
369 static void dec_net_namespaces(struct ucounts *ucounts)
371 dec_ucount(ucounts, UCOUNT_NET_NAMESPACES);
374 static struct kmem_cache *net_cachep __ro_after_init;
375 static struct workqueue_struct *netns_wq;
377 static struct net *net_alloc(void)
379 struct net *net = NULL;
380 struct net_generic *ng;
382 ng = net_alloc_generic();
386 net = kmem_cache_zalloc(net_cachep, GFP_KERNEL);
390 rcu_assign_pointer(net->gen, ng);
399 static void net_free(struct net *net)
401 kfree(rcu_access_pointer(net->gen));
402 kmem_cache_free(net_cachep, net);
405 void net_drop_ns(void *p)
408 if (ns && refcount_dec_and_test(&ns->passive))
412 struct net *copy_net_ns(unsigned long flags,
413 struct user_namespace *user_ns, struct net *old_net)
415 struct ucounts *ucounts;
419 if (!(flags & CLONE_NEWNET))
420 return get_net(old_net);
422 ucounts = inc_net_namespaces(user_ns);
424 return ERR_PTR(-ENOSPC);
431 refcount_set(&net->passive, 1);
432 net->ucounts = ucounts;
433 get_user_ns(user_ns);
435 rv = down_read_killable(&pernet_ops_rwsem);
439 rv = setup_net(net, user_ns);
441 up_read(&pernet_ops_rwsem);
445 put_user_ns(user_ns);
448 dec_net_namespaces(ucounts);
455 * net_ns_get_ownership - get sysfs ownership data for @net
456 * @net: network namespace in question (can be NULL)
457 * @uid: kernel user ID for sysfs objects
458 * @gid: kernel group ID for sysfs objects
460 * Returns the uid/gid pair of root in the user namespace associated with the
461 * given network namespace.
463 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid)
466 kuid_t ns_root_uid = make_kuid(net->user_ns, 0);
467 kgid_t ns_root_gid = make_kgid(net->user_ns, 0);
469 if (uid_valid(ns_root_uid))
472 if (gid_valid(ns_root_gid))
475 *uid = GLOBAL_ROOT_UID;
476 *gid = GLOBAL_ROOT_GID;
479 EXPORT_SYMBOL_GPL(net_ns_get_ownership);
481 static void unhash_nsid(struct net *net, struct net *last)
484 /* This function is only called from cleanup_net() work,
485 * and this work is the only process, that may delete
486 * a net from net_namespace_list. So, when the below
487 * is executing, the list may only grow. Thus, we do not
488 * use for_each_net_rcu() or net_rwsem.
493 spin_lock_bh(&tmp->nsid_lock);
494 id = __peernet2id(tmp, net);
496 idr_remove(&tmp->netns_ids, id);
497 spin_unlock_bh(&tmp->nsid_lock);
499 rtnl_net_notifyid(tmp, RTM_DELNSID, id);
503 spin_lock_bh(&net->nsid_lock);
504 idr_destroy(&net->netns_ids);
505 spin_unlock_bh(&net->nsid_lock);
508 static LLIST_HEAD(cleanup_list);
510 static void cleanup_net(struct work_struct *work)
512 const struct pernet_operations *ops;
513 struct net *net, *tmp, *last;
514 struct llist_node *net_kill_list;
515 LIST_HEAD(net_exit_list);
517 /* Atomically snapshot the list of namespaces to cleanup */
518 net_kill_list = llist_del_all(&cleanup_list);
520 down_read(&pernet_ops_rwsem);
522 /* Don't let anyone else find us. */
523 down_write(&net_rwsem);
524 llist_for_each_entry(net, net_kill_list, cleanup_list)
525 list_del_rcu(&net->list);
526 /* Cache last net. After we unlock rtnl, no one new net
527 * added to net_namespace_list can assign nsid pointer
528 * to a net from net_kill_list (see peernet2id_alloc()).
529 * So, we skip them in unhash_nsid().
531 * Note, that unhash_nsid() does not delete nsid links
532 * between net_kill_list's nets, as they've already
533 * deleted from net_namespace_list. But, this would be
534 * useless anyway, as netns_ids are destroyed there.
536 last = list_last_entry(&net_namespace_list, struct net, list);
537 up_write(&net_rwsem);
539 llist_for_each_entry(net, net_kill_list, cleanup_list) {
540 unhash_nsid(net, last);
541 list_add_tail(&net->exit_list, &net_exit_list);
545 * Another CPU might be rcu-iterating the list, wait for it.
546 * This needs to be before calling the exit() notifiers, so
547 * the rcu_barrier() below isn't sufficient alone.
551 /* Run all of the network namespace exit methods */
552 list_for_each_entry_reverse(ops, &pernet_list, list)
553 ops_exit_list(ops, &net_exit_list);
555 /* Free the net generic variables */
556 list_for_each_entry_reverse(ops, &pernet_list, list)
557 ops_free_list(ops, &net_exit_list);
559 up_read(&pernet_ops_rwsem);
561 /* Ensure there are no outstanding rcu callbacks using this
566 /* Finally it is safe to free my network namespace structure */
567 list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
568 list_del_init(&net->exit_list);
569 dec_net_namespaces(net->ucounts);
570 put_user_ns(net->user_ns);
576 * net_ns_barrier - wait until concurrent net_cleanup_work is done
578 * cleanup_net runs from work queue and will first remove namespaces
579 * from the global list, then run net exit functions.
581 * Call this in module exit path to make sure that all netns
582 * ->exit ops have been invoked before the function is removed.
584 void net_ns_barrier(void)
586 down_write(&pernet_ops_rwsem);
587 up_write(&pernet_ops_rwsem);
589 EXPORT_SYMBOL(net_ns_barrier);
591 static DECLARE_WORK(net_cleanup_work, cleanup_net);
593 void __put_net(struct net *net)
595 /* Cleanup the network namespace in process context */
596 if (llist_add(&net->cleanup_list, &cleanup_list))
597 queue_work(netns_wq, &net_cleanup_work);
599 EXPORT_SYMBOL_GPL(__put_net);
601 struct net *get_net_ns_by_fd(int fd)
604 struct ns_common *ns;
607 file = proc_ns_fget(fd);
609 return ERR_CAST(file);
611 ns = get_proc_ns(file_inode(file));
612 if (ns->ops == &netns_operations)
613 net = get_net(container_of(ns, struct net, ns));
615 net = ERR_PTR(-EINVAL);
622 struct net *get_net_ns_by_fd(int fd)
624 return ERR_PTR(-EINVAL);
627 EXPORT_SYMBOL_GPL(get_net_ns_by_fd);
629 struct net *get_net_ns_by_pid(pid_t pid)
631 struct task_struct *tsk;
634 /* Lookup the network namespace */
635 net = ERR_PTR(-ESRCH);
637 tsk = find_task_by_vpid(pid);
639 struct nsproxy *nsproxy;
641 nsproxy = tsk->nsproxy;
643 net = get_net(nsproxy->net_ns);
649 EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
651 static __net_init int net_ns_net_init(struct net *net)
654 net->ns.ops = &netns_operations;
656 return ns_alloc_inum(&net->ns);
659 static __net_exit void net_ns_net_exit(struct net *net)
661 ns_free_inum(&net->ns);
664 static struct pernet_operations __net_initdata net_ns_ops = {
665 .init = net_ns_net_init,
666 .exit = net_ns_net_exit,
669 static const struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = {
670 [NETNSA_NONE] = { .type = NLA_UNSPEC },
671 [NETNSA_NSID] = { .type = NLA_S32 },
672 [NETNSA_PID] = { .type = NLA_U32 },
673 [NETNSA_FD] = { .type = NLA_U32 },
674 [NETNSA_TARGET_NSID] = { .type = NLA_S32 },
677 static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh,
678 struct netlink_ext_ack *extack)
680 struct net *net = sock_net(skb->sk);
681 struct nlattr *tb[NETNSA_MAX + 1];
686 err = nlmsg_parse_deprecated(nlh, sizeof(struct rtgenmsg), tb,
687 NETNSA_MAX, rtnl_net_policy, extack);
690 if (!tb[NETNSA_NSID]) {
691 NL_SET_ERR_MSG(extack, "nsid is missing");
694 nsid = nla_get_s32(tb[NETNSA_NSID]);
696 if (tb[NETNSA_PID]) {
697 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
698 nla = tb[NETNSA_PID];
699 } else if (tb[NETNSA_FD]) {
700 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
703 NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
707 NL_SET_BAD_ATTR(extack, nla);
708 NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
709 return PTR_ERR(peer);
712 spin_lock_bh(&net->nsid_lock);
713 if (__peernet2id(net, peer) >= 0) {
714 spin_unlock_bh(&net->nsid_lock);
716 NL_SET_BAD_ATTR(extack, nla);
717 NL_SET_ERR_MSG(extack,
718 "Peer netns already has a nsid assigned");
722 err = alloc_netid(net, peer, nsid);
723 spin_unlock_bh(&net->nsid_lock);
725 rtnl_net_notifyid(net, RTM_NEWNSID, err);
727 } else if (err == -ENOSPC && nsid >= 0) {
729 NL_SET_BAD_ATTR(extack, tb[NETNSA_NSID]);
730 NL_SET_ERR_MSG(extack, "The specified nsid is already used");
737 static int rtnl_net_get_size(void)
739 return NLMSG_ALIGN(sizeof(struct rtgenmsg))
740 + nla_total_size(sizeof(s32)) /* NETNSA_NSID */
741 + nla_total_size(sizeof(s32)) /* NETNSA_CURRENT_NSID */
745 struct net_fill_args {
755 static int rtnl_net_fill(struct sk_buff *skb, struct net_fill_args *args)
757 struct nlmsghdr *nlh;
758 struct rtgenmsg *rth;
760 nlh = nlmsg_put(skb, args->portid, args->seq, args->cmd, sizeof(*rth),
765 rth = nlmsg_data(nlh);
766 rth->rtgen_family = AF_UNSPEC;
768 if (nla_put_s32(skb, NETNSA_NSID, args->nsid))
769 goto nla_put_failure;
772 nla_put_s32(skb, NETNSA_CURRENT_NSID, args->ref_nsid))
773 goto nla_put_failure;
779 nlmsg_cancel(skb, nlh);
783 static int rtnl_net_valid_getid_req(struct sk_buff *skb,
784 const struct nlmsghdr *nlh,
786 struct netlink_ext_ack *extack)
790 if (!netlink_strict_get_check(skb))
791 return nlmsg_parse_deprecated(nlh, sizeof(struct rtgenmsg),
792 tb, NETNSA_MAX, rtnl_net_policy,
795 err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct rtgenmsg), tb,
796 NETNSA_MAX, rtnl_net_policy,
801 for (i = 0; i <= NETNSA_MAX; i++) {
809 case NETNSA_TARGET_NSID:
812 NL_SET_ERR_MSG(extack, "Unsupported attribute in peer netns getid request");
820 static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh,
821 struct netlink_ext_ack *extack)
823 struct net *net = sock_net(skb->sk);
824 struct nlattr *tb[NETNSA_MAX + 1];
825 struct net_fill_args fillargs = {
826 .portid = NETLINK_CB(skb).portid,
827 .seq = nlh->nlmsg_seq,
830 struct net *peer, *target = net;
835 err = rtnl_net_valid_getid_req(skb, nlh, tb, extack);
838 if (tb[NETNSA_PID]) {
839 peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
840 nla = tb[NETNSA_PID];
841 } else if (tb[NETNSA_FD]) {
842 peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
844 } else if (tb[NETNSA_NSID]) {
845 peer = get_net_ns_by_id(net, nla_get_s32(tb[NETNSA_NSID]));
847 peer = ERR_PTR(-ENOENT);
848 nla = tb[NETNSA_NSID];
850 NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
855 NL_SET_BAD_ATTR(extack, nla);
856 NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
857 return PTR_ERR(peer);
860 if (tb[NETNSA_TARGET_NSID]) {
861 int id = nla_get_s32(tb[NETNSA_TARGET_NSID]);
863 target = rtnl_get_net_ns_capable(NETLINK_CB(skb).sk, id);
864 if (IS_ERR(target)) {
865 NL_SET_BAD_ATTR(extack, tb[NETNSA_TARGET_NSID]);
866 NL_SET_ERR_MSG(extack,
867 "Target netns reference is invalid");
868 err = PTR_ERR(target);
871 fillargs.add_ref = true;
872 fillargs.ref_nsid = peernet2id(net, peer);
875 msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
881 fillargs.nsid = peernet2id(target, peer);
882 err = rtnl_net_fill(msg, &fillargs);
886 err = rtnl_unicast(msg, net, NETLINK_CB(skb).portid);
892 if (fillargs.add_ref)
898 struct rtnl_net_dump_cb {
902 struct net_fill_args fillargs;
907 static int rtnl_net_dumpid_one(int id, void *peer, void *data)
909 struct rtnl_net_dump_cb *net_cb = (struct rtnl_net_dump_cb *)data;
912 if (net_cb->idx < net_cb->s_idx)
915 net_cb->fillargs.nsid = id;
916 if (net_cb->fillargs.add_ref)
917 net_cb->fillargs.ref_nsid = __peernet2id(net_cb->ref_net, peer);
918 ret = rtnl_net_fill(net_cb->skb, &net_cb->fillargs);
927 static int rtnl_valid_dump_net_req(const struct nlmsghdr *nlh, struct sock *sk,
928 struct rtnl_net_dump_cb *net_cb,
929 struct netlink_callback *cb)
931 struct netlink_ext_ack *extack = cb->extack;
932 struct nlattr *tb[NETNSA_MAX + 1];
935 err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct rtgenmsg), tb,
936 NETNSA_MAX, rtnl_net_policy,
941 for (i = 0; i <= NETNSA_MAX; i++) {
945 if (i == NETNSA_TARGET_NSID) {
948 net = rtnl_get_net_ns_capable(sk, nla_get_s32(tb[i]));
950 NL_SET_BAD_ATTR(extack, tb[i]);
951 NL_SET_ERR_MSG(extack,
952 "Invalid target network namespace id");
955 net_cb->fillargs.add_ref = true;
956 net_cb->ref_net = net_cb->tgt_net;
957 net_cb->tgt_net = net;
959 NL_SET_BAD_ATTR(extack, tb[i]);
960 NL_SET_ERR_MSG(extack,
961 "Unsupported attribute in dump request");
969 static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb)
971 struct rtnl_net_dump_cb net_cb = {
972 .tgt_net = sock_net(skb->sk),
975 .portid = NETLINK_CB(cb->skb).portid,
976 .seq = cb->nlh->nlmsg_seq,
977 .flags = NLM_F_MULTI,
981 .s_idx = cb->args[0],
985 if (cb->strict_check) {
986 err = rtnl_valid_dump_net_req(cb->nlh, skb->sk, &net_cb, cb);
991 spin_lock_bh(&net_cb.tgt_net->nsid_lock);
992 if (net_cb.fillargs.add_ref &&
993 !net_eq(net_cb.ref_net, net_cb.tgt_net) &&
994 !spin_trylock_bh(&net_cb.ref_net->nsid_lock)) {
995 spin_unlock_bh(&net_cb.tgt_net->nsid_lock);
999 idr_for_each(&net_cb.tgt_net->netns_ids, rtnl_net_dumpid_one, &net_cb);
1000 if (net_cb.fillargs.add_ref &&
1001 !net_eq(net_cb.ref_net, net_cb.tgt_net))
1002 spin_unlock_bh(&net_cb.ref_net->nsid_lock);
1003 spin_unlock_bh(&net_cb.tgt_net->nsid_lock);
1005 cb->args[0] = net_cb.idx;
1007 if (net_cb.fillargs.add_ref)
1008 put_net(net_cb.tgt_net);
1009 return err < 0 ? err : skb->len;
1012 static void rtnl_net_notifyid(struct net *net, int cmd, int id)
1014 struct net_fill_args fillargs = {
1018 struct sk_buff *msg;
1021 msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
1025 err = rtnl_net_fill(msg, &fillargs);
1029 rtnl_notify(msg, net, 0, RTNLGRP_NSID, NULL, 0);
1035 rtnl_set_sk_err(net, RTNLGRP_NSID, err);
1038 static int __init net_ns_init(void)
1040 struct net_generic *ng;
1042 #ifdef CONFIG_NET_NS
1043 net_cachep = kmem_cache_create("net_namespace", sizeof(struct net),
1045 SLAB_PANIC|SLAB_ACCOUNT, NULL);
1047 /* Create workqueue for cleanup */
1048 netns_wq = create_singlethread_workqueue("netns");
1050 panic("Could not create netns workq");
1053 ng = net_alloc_generic();
1055 panic("Could not allocate generic netns");
1057 rcu_assign_pointer(init_net.gen, ng);
1059 down_write(&pernet_ops_rwsem);
1060 if (setup_net(&init_net, &init_user_ns))
1061 panic("Could not setup the initial network namespace");
1063 init_net_initialized = true;
1064 up_write(&pernet_ops_rwsem);
1066 if (register_pernet_subsys(&net_ns_ops))
1067 panic("Could not register network namespace subsystems");
1069 rtnl_register(PF_UNSPEC, RTM_NEWNSID, rtnl_net_newid, NULL,
1070 RTNL_FLAG_DOIT_UNLOCKED);
1071 rtnl_register(PF_UNSPEC, RTM_GETNSID, rtnl_net_getid, rtnl_net_dumpid,
1072 RTNL_FLAG_DOIT_UNLOCKED);
1077 pure_initcall(net_ns_init);
1079 #ifdef CONFIG_NET_NS
1080 static int __register_pernet_operations(struct list_head *list,
1081 struct pernet_operations *ops)
1085 LIST_HEAD(net_exit_list);
1087 list_add_tail(&ops->list, list);
1088 if (ops->init || (ops->id && ops->size)) {
1089 /* We held write locked pernet_ops_rwsem, and parallel
1090 * setup_net() and cleanup_net() are not possible.
1093 error = ops_init(ops, net);
1096 list_add_tail(&net->exit_list, &net_exit_list);
1102 /* If I have an error cleanup all namespaces I initialized */
1103 list_del(&ops->list);
1104 ops_exit_list(ops, &net_exit_list);
1105 ops_free_list(ops, &net_exit_list);
1109 static void __unregister_pernet_operations(struct pernet_operations *ops)
1112 LIST_HEAD(net_exit_list);
1114 list_del(&ops->list);
1115 /* See comment in __register_pernet_operations() */
1117 list_add_tail(&net->exit_list, &net_exit_list);
1118 ops_exit_list(ops, &net_exit_list);
1119 ops_free_list(ops, &net_exit_list);
1124 static int __register_pernet_operations(struct list_head *list,
1125 struct pernet_operations *ops)
1127 if (!init_net_initialized) {
1128 list_add_tail(&ops->list, list);
1132 return ops_init(ops, &init_net);
1135 static void __unregister_pernet_operations(struct pernet_operations *ops)
1137 if (!init_net_initialized) {
1138 list_del(&ops->list);
1140 LIST_HEAD(net_exit_list);
1141 list_add(&init_net.exit_list, &net_exit_list);
1142 ops_exit_list(ops, &net_exit_list);
1143 ops_free_list(ops, &net_exit_list);
1147 #endif /* CONFIG_NET_NS */
1149 static DEFINE_IDA(net_generic_ids);
1151 static int register_pernet_operations(struct list_head *list,
1152 struct pernet_operations *ops)
1157 error = ida_alloc_min(&net_generic_ids, MIN_PERNET_OPS_ID,
1162 max_gen_ptrs = max(max_gen_ptrs, *ops->id + 1);
1164 error = __register_pernet_operations(list, ops);
1168 ida_free(&net_generic_ids, *ops->id);
1174 static void unregister_pernet_operations(struct pernet_operations *ops)
1176 __unregister_pernet_operations(ops);
1179 ida_free(&net_generic_ids, *ops->id);
1183 * register_pernet_subsys - register a network namespace subsystem
1184 * @ops: pernet operations structure for the subsystem
1186 * Register a subsystem which has init and exit functions
1187 * that are called when network namespaces are created and
1188 * destroyed respectively.
1190 * When registered all network namespace init functions are
1191 * called for every existing network namespace. Allowing kernel
1192 * modules to have a race free view of the set of network namespaces.
1194 * When a new network namespace is created all of the init
1195 * methods are called in the order in which they were registered.
1197 * When a network namespace is destroyed all of the exit methods
1198 * are called in the reverse of the order with which they were
1201 int register_pernet_subsys(struct pernet_operations *ops)
1204 down_write(&pernet_ops_rwsem);
1205 error = register_pernet_operations(first_device, ops);
1206 up_write(&pernet_ops_rwsem);
1209 EXPORT_SYMBOL_GPL(register_pernet_subsys);
1212 * unregister_pernet_subsys - unregister a network namespace subsystem
1213 * @ops: pernet operations structure to manipulate
1215 * Remove the pernet operations structure from the list to be
1216 * used when network namespaces are created or destroyed. In
1217 * addition run the exit method for all existing network
1220 void unregister_pernet_subsys(struct pernet_operations *ops)
1222 down_write(&pernet_ops_rwsem);
1223 unregister_pernet_operations(ops);
1224 up_write(&pernet_ops_rwsem);
1226 EXPORT_SYMBOL_GPL(unregister_pernet_subsys);
1229 * register_pernet_device - register a network namespace device
1230 * @ops: pernet operations structure for the subsystem
1232 * Register a device which has init and exit functions
1233 * that are called when network namespaces are created and
1234 * destroyed respectively.
1236 * When registered all network namespace init functions are
1237 * called for every existing network namespace. Allowing kernel
1238 * modules to have a race free view of the set of network namespaces.
1240 * When a new network namespace is created all of the init
1241 * methods are called in the order in which they were registered.
1243 * When a network namespace is destroyed all of the exit methods
1244 * are called in the reverse of the order with which they were
1247 int register_pernet_device(struct pernet_operations *ops)
1250 down_write(&pernet_ops_rwsem);
1251 error = register_pernet_operations(&pernet_list, ops);
1252 if (!error && (first_device == &pernet_list))
1253 first_device = &ops->list;
1254 up_write(&pernet_ops_rwsem);
1257 EXPORT_SYMBOL_GPL(register_pernet_device);
1260 * unregister_pernet_device - unregister a network namespace netdevice
1261 * @ops: pernet operations structure to manipulate
1263 * Remove the pernet operations structure from the list to be
1264 * used when network namespaces are created or destroyed. In
1265 * addition run the exit method for all existing network
1268 void unregister_pernet_device(struct pernet_operations *ops)
1270 down_write(&pernet_ops_rwsem);
1271 if (&ops->list == first_device)
1272 first_device = first_device->next;
1273 unregister_pernet_operations(ops);
1274 up_write(&pernet_ops_rwsem);
1276 EXPORT_SYMBOL_GPL(unregister_pernet_device);
1278 #ifdef CONFIG_NET_NS
1279 static struct ns_common *netns_get(struct task_struct *task)
1281 struct net *net = NULL;
1282 struct nsproxy *nsproxy;
1285 nsproxy = task->nsproxy;
1287 net = get_net(nsproxy->net_ns);
1290 return net ? &net->ns : NULL;
1293 static inline struct net *to_net_ns(struct ns_common *ns)
1295 return container_of(ns, struct net, ns);
1298 static void netns_put(struct ns_common *ns)
1300 put_net(to_net_ns(ns));
1303 static int netns_install(struct nsproxy *nsproxy, struct ns_common *ns)
1305 struct net *net = to_net_ns(ns);
1307 if (!ns_capable(net->user_ns, CAP_SYS_ADMIN) ||
1308 !ns_capable(current_user_ns(), CAP_SYS_ADMIN))
1311 put_net(nsproxy->net_ns);
1312 nsproxy->net_ns = get_net(net);
1316 static struct user_namespace *netns_owner(struct ns_common *ns)
1318 return to_net_ns(ns)->user_ns;
1321 const struct proc_ns_operations netns_operations = {
1323 .type = CLONE_NEWNET,
1326 .install = netns_install,
1327 .owner = netns_owner,