| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #include <linux/workqueue.h> |
| #include <linux/rtnetlink.h> |
| #include <linux/cache.h> |
| #include <linux/slab.h> |
| #include <linux/list.h> |
| #include <linux/delay.h> |
| #include <linux/sched.h> |
| #include <linux/idr.h> |
| #include <linux/rculist.h> |
| #include <linux/nsproxy.h> |
| #include <linux/fs.h> |
| #include <linux/proc_ns.h> |
| #include <linux/file.h> |
| #include <linux/export.h> |
| #include <linux/user_namespace.h> |
| #include <linux/net_namespace.h> |
| #include <linux/rtnetlink.h> |
| #include <net/sock.h> |
| #include <net/netlink.h> |
| #include <net/net_namespace.h> |
| #include <net/netns/generic.h> |
| |
| /* |
| * Our network namespace constructor/destructor lists |
| */ |
| |
| static LIST_HEAD(pernet_list); |
| static struct list_head *first_device = &pernet_list; |
| DEFINE_MUTEX(net_mutex); |
| |
| LIST_HEAD(net_namespace_list); |
| EXPORT_SYMBOL_GPL(net_namespace_list); |
| |
| struct net init_net = { |
| .dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head), |
| }; |
| EXPORT_SYMBOL(init_net); |
| |
| #define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */ |
| |
| static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS; |
| |
| static struct net_generic *net_alloc_generic(void) |
| { |
| struct net_generic *ng; |
| size_t generic_size = offsetof(struct net_generic, ptr[max_gen_ptrs]); |
| |
| ng = kzalloc(generic_size, GFP_KERNEL); |
| if (ng) |
| ng->len = max_gen_ptrs; |
| |
| return ng; |
| } |
| |
| static int net_assign_generic(struct net *net, int id, void *data) |
| { |
| struct net_generic *ng, *old_ng; |
| |
| BUG_ON(!mutex_is_locked(&net_mutex)); |
| BUG_ON(id == 0); |
| |
| old_ng = rcu_dereference_protected(net->gen, |
| lockdep_is_held(&net_mutex)); |
| ng = old_ng; |
| if (old_ng->len >= id) |
| goto assign; |
| |
| ng = net_alloc_generic(); |
| if (ng == NULL) |
| return -ENOMEM; |
| |
| /* |
| * Some synchronisation notes: |
| * |
| * The net_generic explores the net->gen array inside rcu |
| * read section. Besides once set the net->gen->ptr[x] |
| * pointer never changes (see rules in netns/generic.h). |
| * |
| * That said, we simply duplicate this array and schedule |
| * the old copy for kfree after a grace period. |
| */ |
| |
| memcpy(&ng->ptr, &old_ng->ptr, old_ng->len * sizeof(void*)); |
| |
| rcu_assign_pointer(net->gen, ng); |
| kfree_rcu(old_ng, rcu); |
| assign: |
| ng->ptr[id - 1] = data; |
| return 0; |
| } |
| |
| static int ops_init(const struct pernet_operations *ops, struct net *net) |
| { |
| int err = -ENOMEM; |
| void *data = NULL; |
| |
| if (ops->id && ops->size) { |
| data = kzalloc(ops->size, GFP_KERNEL); |
| if (!data) |
| goto out; |
| |
| err = net_assign_generic(net, *ops->id, data); |
| if (err) |
| goto cleanup; |
| } |
| err = 0; |
| if (ops->init) |
| err = ops->init(net); |
| if (!err) |
| return 0; |
| |
| cleanup: |
| kfree(data); |
| |
| out: |
| return err; |
| } |
| |
| static void ops_free(const struct pernet_operations *ops, struct net *net) |
| { |
| if (ops->id && ops->size) { |
| int id = *ops->id; |
| kfree(net_generic(net, id)); |
| } |
| } |
| |
| static void ops_exit_list(const struct pernet_operations *ops, |
| struct list_head *net_exit_list) |
| { |
| struct net *net; |
| if (ops->exit) { |
| list_for_each_entry(net, net_exit_list, exit_list) |
| ops->exit(net); |
| } |
| if (ops->exit_batch) |
| ops->exit_batch(net_exit_list); |
| } |
| |
| static void ops_free_list(const struct pernet_operations *ops, |
| struct list_head *net_exit_list) |
| { |
| struct net *net; |
| if (ops->size && ops->id) { |
| list_for_each_entry(net, net_exit_list, exit_list) |
| ops_free(ops, net); |
| } |
| } |
| |
| static int alloc_netid(struct net *net, struct net *peer, int reqid) |
| { |
| int min = 0, max = 0; |
| |
| ASSERT_RTNL(); |
| |
| if (reqid >= 0) { |
| min = reqid; |
| max = reqid + 1; |
| } |
| |
| return idr_alloc(&net->netns_ids, peer, min, max, GFP_KERNEL); |
| } |
| |
| /* This function is used by idr_for_each(). If net is equal to peer, the |
| * function returns the id so that idr_for_each() stops. Because we cannot |
| * returns the id 0 (idr_for_each() will not stop), we return the magic value |
| * NET_ID_ZERO (-1) for it. |
| */ |
| #define NET_ID_ZERO -1 |
| static int net_eq_idr(int id, void *net, void *peer) |
| { |
| if (net_eq(net, peer)) |
| return id ? : NET_ID_ZERO; |
| return 0; |
| } |
| |
| static int __peernet2id(struct net *net, struct net *peer, bool alloc) |
| { |
| int id = idr_for_each(&net->netns_ids, net_eq_idr, peer); |
| |
| ASSERT_RTNL(); |
| |
| /* Magic value for id 0. */ |
| if (id == NET_ID_ZERO) |
| return 0; |
| if (id > 0) |
| return id; |
| |
| if (alloc) |
| return alloc_netid(net, peer, -1); |
| |
| return -ENOENT; |
| } |
| |
| /* This function returns the id of a peer netns. If no id is assigned, one will |
| * be allocated and returned. |
| */ |
| int peernet2id(struct net *net, struct net *peer) |
| { |
| int id = __peernet2id(net, peer, true); |
| |
| return id >= 0 ? id : NETNSA_NSID_NOT_ASSIGNED; |
| } |
| EXPORT_SYMBOL(peernet2id); |
| |
| struct net *get_net_ns_by_id(struct net *net, int id) |
| { |
| struct net *peer; |
| |
| if (id < 0) |
| return NULL; |
| |
| rcu_read_lock(); |
| peer = idr_find(&net->netns_ids, id); |
| if (peer) |
| get_net(peer); |
| rcu_read_unlock(); |
| |
| return peer; |
| } |
| |
| /* |
| * setup_net runs the initializers for the network namespace object. |
| */ |
| static __net_init int setup_net(struct net *net, struct user_namespace *user_ns) |
| { |
| /* Must be called with net_mutex held */ |
| const struct pernet_operations *ops, *saved_ops; |
| int error = 0; |
| LIST_HEAD(net_exit_list); |
| |
| atomic_set(&net->count, 1); |
| atomic_set(&net->passive, 1); |
| net->dev_base_seq = 1; |
| net->user_ns = user_ns; |
| idr_init(&net->netns_ids); |
| |
| #ifdef NETNS_REFCNT_DEBUG |
| atomic_set(&net->use_count, 0); |
| #endif |
| |
| list_for_each_entry(ops, &pernet_list, list) { |
| error = ops_init(ops, net); |
| if (error < 0) |
| goto out_undo; |
| } |
| out: |
| return error; |
| |
| out_undo: |
| /* Walk through the list backwards calling the exit functions |
| * for the pernet modules whose init functions did not fail. |
| */ |
| list_add(&net->exit_list, &net_exit_list); |
| saved_ops = ops; |
| list_for_each_entry_continue_reverse(ops, &pernet_list, list) |
| ops_exit_list(ops, &net_exit_list); |
| |
| ops = saved_ops; |
| list_for_each_entry_continue_reverse(ops, &pernet_list, list) |
| ops_free_list(ops, &net_exit_list); |
| |
| rcu_barrier(); |
| goto out; |
| } |
| |
| |
| #ifdef CONFIG_NET_NS |
| static struct kmem_cache *net_cachep; |
| static struct workqueue_struct *netns_wq; |
| |
| static struct net *net_alloc(void) |
| { |
| struct net *net = NULL; |
| struct net_generic *ng; |
| |
| ng = net_alloc_generic(); |
| if (!ng) |
| goto out; |
| |
| net = kmem_cache_zalloc(net_cachep, GFP_KERNEL); |
| if (!net) |
| goto out_free; |
| |
| rcu_assign_pointer(net->gen, ng); |
| out: |
| return net; |
| |
| out_free: |
| kfree(ng); |
| goto out; |
| } |
| |
| static void net_free(struct net *net) |
| { |
| #ifdef NETNS_REFCNT_DEBUG |
| if (unlikely(atomic_read(&net->use_count) != 0)) { |
| pr_emerg("network namespace not free! Usage: %d\n", |
| atomic_read(&net->use_count)); |
| return; |
| } |
| #endif |
| kfree(rcu_access_pointer(net->gen)); |
| kmem_cache_free(net_cachep, net); |
| } |
| |
| void net_drop_ns(void *p) |
| { |
| struct net *ns = p; |
| if (ns && atomic_dec_and_test(&ns->passive)) |
| net_free(ns); |
| } |
| |
| struct net *copy_net_ns(unsigned long flags, |
| struct user_namespace *user_ns, struct net *old_net) |
| { |
| struct net *net; |
| int rv; |
| |
| if (!(flags & CLONE_NEWNET)) |
| return get_net(old_net); |
| |
| net = net_alloc(); |
| if (!net) |
| return ERR_PTR(-ENOMEM); |
| |
| get_user_ns(user_ns); |
| |
| mutex_lock(&net_mutex); |
| rv = setup_net(net, user_ns); |
| if (rv == 0) { |
| rtnl_lock(); |
| list_add_tail_rcu(&net->list, &net_namespace_list); |
| rtnl_unlock(); |
| } |
| mutex_unlock(&net_mutex); |
| if (rv < 0) { |
| put_user_ns(user_ns); |
| net_drop_ns(net); |
| return ERR_PTR(rv); |
| } |
| return net; |
| } |
| |
| static DEFINE_SPINLOCK(cleanup_list_lock); |
| static LIST_HEAD(cleanup_list); /* Must hold cleanup_list_lock to touch */ |
| |
| static void cleanup_net(struct work_struct *work) |
| { |
| const struct pernet_operations *ops; |
| struct net *net, *tmp; |
| struct list_head net_kill_list; |
| LIST_HEAD(net_exit_list); |
| |
| /* Atomically snapshot the list of namespaces to cleanup */ |
| spin_lock_irq(&cleanup_list_lock); |
| list_replace_init(&cleanup_list, &net_kill_list); |
| spin_unlock_irq(&cleanup_list_lock); |
| |
| mutex_lock(&net_mutex); |
| |
| /* Don't let anyone else find us. */ |
| rtnl_lock(); |
| list_for_each_entry(net, &net_kill_list, cleanup_list) { |
| list_del_rcu(&net->list); |
| list_add_tail(&net->exit_list, &net_exit_list); |
| for_each_net(tmp) { |
| int id = __peernet2id(tmp, net, false); |
| |
| if (id >= 0) |
| idr_remove(&tmp->netns_ids, id); |
| } |
| idr_destroy(&net->netns_ids); |
| |
| } |
| rtnl_unlock(); |
| |
| /* |
| * Another CPU might be rcu-iterating the list, wait for it. |
| * This needs to be before calling the exit() notifiers, so |
| * the rcu_barrier() below isn't sufficient alone. |
| */ |
| synchronize_rcu(); |
| |
| /* Run all of the network namespace exit methods */ |
| list_for_each_entry_reverse(ops, &pernet_list, list) |
| ops_exit_list(ops, &net_exit_list); |
| |
| /* Free the net generic variables */ |
| list_for_each_entry_reverse(ops, &pernet_list, list) |
| ops_free_list(ops, &net_exit_list); |
| |
| mutex_unlock(&net_mutex); |
| |
| /* Ensure there are no outstanding rcu callbacks using this |
| * network namespace. |
| */ |
| rcu_barrier(); |
| |
| /* Finally it is safe to free my network namespace structure */ |
| list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) { |
| list_del_init(&net->exit_list); |
| put_user_ns(net->user_ns); |
| net_drop_ns(net); |
| } |
| } |
| static DECLARE_WORK(net_cleanup_work, cleanup_net); |
| |
| void __put_net(struct net *net) |
| { |
| /* Cleanup the network namespace in process context */ |
| unsigned long flags; |
| |
| spin_lock_irqsave(&cleanup_list_lock, flags); |
| list_add(&net->cleanup_list, &cleanup_list); |
| spin_unlock_irqrestore(&cleanup_list_lock, flags); |
| |
| queue_work(netns_wq, &net_cleanup_work); |
| } |
| EXPORT_SYMBOL_GPL(__put_net); |
| |
| struct net *get_net_ns_by_fd(int fd) |
| { |
| struct file *file; |
| struct ns_common *ns; |
| struct net *net; |
| |
| file = proc_ns_fget(fd); |
| if (IS_ERR(file)) |
| return ERR_CAST(file); |
| |
| ns = get_proc_ns(file_inode(file)); |
| if (ns->ops == &netns_operations) |
| net = get_net(container_of(ns, struct net, ns)); |
| else |
| net = ERR_PTR(-EINVAL); |
| |
| fput(file); |
| return net; |
| } |
| |
| #else |
| struct net *get_net_ns_by_fd(int fd) |
| { |
| return ERR_PTR(-EINVAL); |
| } |
| #endif |
| |
| struct net *get_net_ns_by_pid(pid_t pid) |
| { |
| struct task_struct *tsk; |
| struct net *net; |
| |
| /* Lookup the network namespace */ |
| net = ERR_PTR(-ESRCH); |
| rcu_read_lock(); |
| tsk = find_task_by_vpid(pid); |
| if (tsk) { |
| struct nsproxy *nsproxy; |
| task_lock(tsk); |
| nsproxy = tsk->nsproxy; |
| if (nsproxy) |
| net = get_net(nsproxy->net_ns); |
| task_unlock(tsk); |
| } |
| rcu_read_unlock(); |
| return net; |
| } |
| EXPORT_SYMBOL_GPL(get_net_ns_by_pid); |
| |
| static __net_init int net_ns_net_init(struct net *net) |
| { |
| #ifdef CONFIG_NET_NS |
| net->ns.ops = &netns_operations; |
| #endif |
| return ns_alloc_inum(&net->ns); |
| } |
| |
| static __net_exit void net_ns_net_exit(struct net *net) |
| { |
| ns_free_inum(&net->ns); |
| } |
| |
| static struct pernet_operations __net_initdata net_ns_ops = { |
| .init = net_ns_net_init, |
| .exit = net_ns_net_exit, |
| }; |
| |
| static struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = { |
| [NETNSA_NONE] = { .type = NLA_UNSPEC }, |
| [NETNSA_NSID] = { .type = NLA_S32 }, |
| [NETNSA_PID] = { .type = NLA_U32 }, |
| [NETNSA_FD] = { .type = NLA_U32 }, |
| }; |
| |
| static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh) |
| { |
| struct net *net = sock_net(skb->sk); |
| struct nlattr *tb[NETNSA_MAX + 1]; |
| struct net *peer; |
| int nsid, err; |
| |
| err = nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX, |
| rtnl_net_policy); |
| if (err < 0) |
| return err; |
| if (!tb[NETNSA_NSID]) |
| return -EINVAL; |
| nsid = nla_get_s32(tb[NETNSA_NSID]); |
| |
| if (tb[NETNSA_PID]) |
| peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID])); |
| else if (tb[NETNSA_FD]) |
| peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD])); |
| else |
| return -EINVAL; |
| if (IS_ERR(peer)) |
| return PTR_ERR(peer); |
| |
| if (__peernet2id(net, peer, false) >= 0) { |
| err = -EEXIST; |
| goto out; |
| } |
| |
| err = alloc_netid(net, peer, nsid); |
| if (err > 0) |
| err = 0; |
| out: |
| put_net(peer); |
| return err; |
| } |
| |
| static int rtnl_net_get_size(void) |
| { |
| return NLMSG_ALIGN(sizeof(struct rtgenmsg)) |
| + nla_total_size(sizeof(s32)) /* NETNSA_NSID */ |
| ; |
| } |
| |
| static int rtnl_net_fill(struct sk_buff *skb, u32 portid, u32 seq, int flags, |
| int cmd, struct net *net, struct net *peer) |
| { |
| struct nlmsghdr *nlh; |
| struct rtgenmsg *rth; |
| int id; |
| |
| ASSERT_RTNL(); |
| |
| nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rth), flags); |
| if (!nlh) |
| return -EMSGSIZE; |
| |
| rth = nlmsg_data(nlh); |
| rth->rtgen_family = AF_UNSPEC; |
| |
| id = __peernet2id(net, peer, false); |
| if (id < 0) |
| id = NETNSA_NSID_NOT_ASSIGNED; |
| if (nla_put_s32(skb, NETNSA_NSID, id)) |
| goto nla_put_failure; |
| |
| nlmsg_end(skb, nlh); |
| return 0; |
| |
| nla_put_failure: |
| nlmsg_cancel(skb, nlh); |
| return -EMSGSIZE; |
| } |
| |
| static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh) |
| { |
| struct net *net = sock_net(skb->sk); |
| struct nlattr *tb[NETNSA_MAX + 1]; |
| struct sk_buff *msg; |
| int err = -ENOBUFS; |
| struct net *peer; |
| |
| err = nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX, |
| rtnl_net_policy); |
| if (err < 0) |
| return err; |
| if (tb[NETNSA_PID]) |
| peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID])); |
| else if (tb[NETNSA_FD]) |
| peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD])); |
| else |
| return -EINVAL; |
| |
| if (IS_ERR(peer)) |
| return PTR_ERR(peer); |
| |
| msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL); |
| if (!msg) { |
| err = -ENOMEM; |
| goto out; |
| } |
| |
| err = rtnl_net_fill(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq, 0, |
| RTM_GETNSID, net, peer); |
| if (err < 0) |
| goto err_out; |
| |
| err = rtnl_unicast(msg, net, NETLINK_CB(skb).portid); |
| goto out; |
| |
| err_out: |
| nlmsg_free(msg); |
| out: |
| put_net(peer); |
| return err; |
| } |
| |
| static int __init net_ns_init(void) |
| { |
| struct net_generic *ng; |
| |
| #ifdef CONFIG_NET_NS |
| net_cachep = kmem_cache_create("net_namespace", sizeof(struct net), |
| SMP_CACHE_BYTES, |
| SLAB_PANIC, NULL); |
| |
| /* Create workqueue for cleanup */ |
| netns_wq = create_singlethread_workqueue("netns"); |
| if (!netns_wq) |
| panic("Could not create netns workq"); |
| #endif |
| |
| ng = net_alloc_generic(); |
| if (!ng) |
| panic("Could not allocate generic netns"); |
| |
| rcu_assign_pointer(init_net.gen, ng); |
| |
| mutex_lock(&net_mutex); |
| if (setup_net(&init_net, &init_user_ns)) |
| panic("Could not setup the initial network namespace"); |
| |
| rtnl_lock(); |
| list_add_tail_rcu(&init_net.list, &net_namespace_list); |
| rtnl_unlock(); |
| |
| mutex_unlock(&net_mutex); |
| |
| register_pernet_subsys(&net_ns_ops); |
| |
| rtnl_register(PF_UNSPEC, RTM_NEWNSID, rtnl_net_newid, NULL, NULL); |
| rtnl_register(PF_UNSPEC, RTM_GETNSID, rtnl_net_getid, NULL, NULL); |
| |
| return 0; |
| } |
| |
| pure_initcall(net_ns_init); |
| |
| #ifdef CONFIG_NET_NS |
| static int __register_pernet_operations(struct list_head *list, |
| struct pernet_operations *ops) |
| { |
| struct net *net; |
| int error; |
| LIST_HEAD(net_exit_list); |
| |
| list_add_tail(&ops->list, list); |
| if (ops->init || (ops->id && ops->size)) { |
| for_each_net(net) { |
| error = ops_init(ops, net); |
| if (error) |
| goto out_undo; |
| list_add_tail(&net->exit_list, &net_exit_list); |
| } |
| } |
| return 0; |
| |
| out_undo: |
| /* If I have an error cleanup all namespaces I initialized */ |
| list_del(&ops->list); |
| ops_exit_list(ops, &net_exit_list); |
| ops_free_list(ops, &net_exit_list); |
| return error; |
| } |
| |
| static void __unregister_pernet_operations(struct pernet_operations *ops) |
| { |
| struct net *net; |
| LIST_HEAD(net_exit_list); |
| |
| list_del(&ops->list); |
| for_each_net(net) |
| list_add_tail(&net->exit_list, &net_exit_list); |
| ops_exit_list(ops, &net_exit_list); |
| ops_free_list(ops, &net_exit_list); |
| } |
| |
| #else |
| |
| static int __register_pernet_operations(struct list_head *list, |
| struct pernet_operations *ops) |
| { |
| return ops_init(ops, &init_net); |
| } |
| |
| static void __unregister_pernet_operations(struct pernet_operations *ops) |
| { |
| LIST_HEAD(net_exit_list); |
| list_add(&init_net.exit_list, &net_exit_list); |
| ops_exit_list(ops, &net_exit_list); |
| ops_free_list(ops, &net_exit_list); |
| } |
| |
| #endif /* CONFIG_NET_NS */ |
| |
| static DEFINE_IDA(net_generic_ids); |
| |
| static int register_pernet_operations(struct list_head *list, |
| struct pernet_operations *ops) |
| { |
| int error; |
| |
| if (ops->id) { |
| again: |
| error = ida_get_new_above(&net_generic_ids, 1, ops->id); |
| if (error < 0) { |
| if (error == -EAGAIN) { |
| ida_pre_get(&net_generic_ids, GFP_KERNEL); |
| goto again; |
| } |
| return error; |
| } |
| max_gen_ptrs = max_t(unsigned int, max_gen_ptrs, *ops->id); |
| } |
| error = __register_pernet_operations(list, ops); |
| if (error) { |
| rcu_barrier(); |
| if (ops->id) |
| ida_remove(&net_generic_ids, *ops->id); |
| } |
| |
| return error; |
| } |
| |
| static void unregister_pernet_operations(struct pernet_operations *ops) |
| { |
| |
| __unregister_pernet_operations(ops); |
| rcu_barrier(); |
| if (ops->id) |
| ida_remove(&net_generic_ids, *ops->id); |
| } |
| |
| /** |
| * register_pernet_subsys - register a network namespace subsystem |
| * @ops: pernet operations structure for the subsystem |
| * |
| * Register a subsystem which has init and exit functions |
| * that are called when network namespaces are created and |
| * destroyed respectively. |
| * |
| * When registered all network namespace init functions are |
| * called for every existing network namespace. Allowing kernel |
| * modules to have a race free view of the set of network namespaces. |
| * |
| * When a new network namespace is created all of the init |
| * methods are called in the order in which they were registered. |
| * |
| * When a network namespace is destroyed all of the exit methods |
| * are called in the reverse of the order with which they were |
| * registered. |
| */ |
| int register_pernet_subsys(struct pernet_operations *ops) |
| { |
| int error; |
| mutex_lock(&net_mutex); |
| error = register_pernet_operations(first_device, ops); |
| mutex_unlock(&net_mutex); |
| return error; |
| } |
| EXPORT_SYMBOL_GPL(register_pernet_subsys); |
| |
| /** |
| * unregister_pernet_subsys - unregister a network namespace subsystem |
| * @ops: pernet operations structure to manipulate |
| * |
| * Remove the pernet operations structure from the list to be |
| * used when network namespaces are created or destroyed. In |
| * addition run the exit method for all existing network |
| * namespaces. |
| */ |
| void unregister_pernet_subsys(struct pernet_operations *ops) |
| { |
| mutex_lock(&net_mutex); |
| unregister_pernet_operations(ops); |
| mutex_unlock(&net_mutex); |
| } |
| EXPORT_SYMBOL_GPL(unregister_pernet_subsys); |
| |
| /** |
| * register_pernet_device - register a network namespace device |
| * @ops: pernet operations structure for the subsystem |
| * |
| * Register a device which has init and exit functions |
| * that are called when network namespaces are created and |
| * destroyed respectively. |
| * |
| * When registered all network namespace init functions are |
| * called for every existing network namespace. Allowing kernel |
| * modules to have a race free view of the set of network namespaces. |
| * |
| * When a new network namespace is created all of the init |
| * methods are called in the order in which they were registered. |
| * |
| * When a network namespace is destroyed all of the exit methods |
| * are called in the reverse of the order with which they were |
| * registered. |
| */ |
| int register_pernet_device(struct pernet_operations *ops) |
| { |
| int error; |
| mutex_lock(&net_mutex); |
| error = register_pernet_operations(&pernet_list, ops); |
| if (!error && (first_device == &pernet_list)) |
| first_device = &ops->list; |
| mutex_unlock(&net_mutex); |
| return error; |
| } |
| EXPORT_SYMBOL_GPL(register_pernet_device); |
| |
| /** |
| * unregister_pernet_device - unregister a network namespace netdevice |
| * @ops: pernet operations structure to manipulate |
| * |
| * Remove the pernet operations structure from the list to be |
| * used when network namespaces are created or destroyed. In |
| * addition run the exit method for all existing network |
| * namespaces. |
| */ |
| void unregister_pernet_device(struct pernet_operations *ops) |
| { |
| mutex_lock(&net_mutex); |
| if (&ops->list == first_device) |
| first_device = first_device->next; |
| unregister_pernet_operations(ops); |
| mutex_unlock(&net_mutex); |
| } |
| EXPORT_SYMBOL_GPL(unregister_pernet_device); |
| |
| #ifdef CONFIG_NET_NS |
| static struct ns_common *netns_get(struct task_struct *task) |
| { |
| struct net *net = NULL; |
| struct nsproxy *nsproxy; |
| |
| task_lock(task); |
| nsproxy = task->nsproxy; |
| if (nsproxy) |
| net = get_net(nsproxy->net_ns); |
| task_unlock(task); |
| |
| return net ? &net->ns : NULL; |
| } |
| |
| static inline struct net *to_net_ns(struct ns_common *ns) |
| { |
| return container_of(ns, struct net, ns); |
| } |
| |
| static void netns_put(struct ns_common *ns) |
| { |
| put_net(to_net_ns(ns)); |
| } |
| |
| static int netns_install(struct nsproxy *nsproxy, struct ns_common *ns) |
| { |
| struct net *net = to_net_ns(ns); |
| |
| if (!ns_capable(net->user_ns, CAP_SYS_ADMIN) || |
| !ns_capable(current_user_ns(), CAP_SYS_ADMIN)) |
| return -EPERM; |
| |
| put_net(nsproxy->net_ns); |
| nsproxy->net_ns = get_net(net); |
| return 0; |
| } |
| |
| const struct proc_ns_operations netns_operations = { |
| .name = "net", |
| .type = CLONE_NEWNET, |
| .get = netns_get, |
| .put = netns_put, |
| .install = netns_install, |
| }; |
| #endif |