2 * Copyright (C) 2006 IBM Corporation
4 * Author: Serge Hallyn <serue@us.ibm.com>
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation, version 2 of the
11 * Jun 2006 - namespaces support
13 * Pavel Emelianov <xemul@openvz.org>
16 #include <linux/module.h>
17 #include <linux/version.h>
18 #include <linux/nsproxy.h>
19 #include <linux/init_task.h>
20 #include <linux/mnt_namespace.h>
21 #include <linux/utsname.h>
22 #include <linux/pid_namespace.h>
23 #include <net/net_namespace.h>
25 static struct kmem_cache *nsproxy_cachep;
27 struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
30 * creates a copy of "orig" with refcount 1.
32 static inline struct nsproxy *clone_nsproxy(struct nsproxy *orig)
36 ns = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL);
38 memcpy(ns, orig, sizeof(struct nsproxy));
39 atomic_set(&ns->count, 1);
45 * Create new nsproxy and all of its the associated namespaces.
46 * Return the newly created nsproxy. Do not attach this to the task,
47 * leave it to the caller to do proper locking and attach it to task.
49 static struct nsproxy *create_new_namespaces(unsigned long flags,
50 struct task_struct *tsk, struct fs_struct *new_fs)
52 struct nsproxy *new_nsp;
55 new_nsp = clone_nsproxy(tsk->nsproxy);
57 return ERR_PTR(-ENOMEM);
59 new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, new_fs);
60 if (IS_ERR(new_nsp->mnt_ns)) {
61 err = PTR_ERR(new_nsp->mnt_ns);
65 new_nsp->uts_ns = copy_utsname(flags, tsk->nsproxy->uts_ns);
66 if (IS_ERR(new_nsp->uts_ns)) {
67 err = PTR_ERR(new_nsp->uts_ns);
71 new_nsp->ipc_ns = copy_ipcs(flags, tsk->nsproxy->ipc_ns);
72 if (IS_ERR(new_nsp->ipc_ns)) {
73 err = PTR_ERR(new_nsp->ipc_ns);
77 new_nsp->pid_ns = copy_pid_ns(flags, task_active_pid_ns(tsk));
78 if (IS_ERR(new_nsp->pid_ns)) {
79 err = PTR_ERR(new_nsp->pid_ns);
83 new_nsp->user_ns = copy_user_ns(flags, tsk->nsproxy->user_ns);
84 if (IS_ERR(new_nsp->user_ns)) {
85 err = PTR_ERR(new_nsp->user_ns);
89 new_nsp->net_ns = copy_net_ns(flags, tsk->nsproxy->net_ns);
90 if (IS_ERR(new_nsp->net_ns)) {
91 err = PTR_ERR(new_nsp->net_ns);
99 put_user_ns(new_nsp->user_ns);
102 put_pid_ns(new_nsp->pid_ns);
105 put_ipc_ns(new_nsp->ipc_ns);
108 put_uts_ns(new_nsp->uts_ns);
111 put_mnt_ns(new_nsp->mnt_ns);
113 kmem_cache_free(nsproxy_cachep, new_nsp);
118 * called from clone. This now handles copy for nsproxy and all
119 * namespaces therein.
121 int copy_namespaces(unsigned long flags, struct task_struct *tsk)
123 struct nsproxy *old_ns = tsk->nsproxy;
124 struct nsproxy *new_ns;
132 if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | CLONE_NEWUSER | CLONE_NEWNET)))
135 if (!capable(CAP_SYS_ADMIN)) {
140 new_ns = create_new_namespaces(flags, tsk, tsk->fs);
141 if (IS_ERR(new_ns)) {
142 err = PTR_ERR(new_ns);
146 err = ns_cgroup_clone(tsk);
152 tsk->nsproxy = new_ns;
159 void free_nsproxy(struct nsproxy *ns)
162 put_mnt_ns(ns->mnt_ns);
164 put_uts_ns(ns->uts_ns);
166 put_ipc_ns(ns->ipc_ns);
168 put_pid_ns(ns->pid_ns);
170 put_user_ns(ns->user_ns);
172 kmem_cache_free(nsproxy_cachep, ns);
176 * Called from unshare. Unshare all the namespaces part of nsproxy.
177 * On success, returns the new nsproxy.
179 int unshare_nsproxy_namespaces(unsigned long unshare_flags,
180 struct nsproxy **new_nsp, struct fs_struct *new_fs)
184 if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
185 CLONE_NEWUSER | CLONE_NEWNET)))
188 if (!capable(CAP_SYS_ADMIN))
191 *new_nsp = create_new_namespaces(unshare_flags, current,
192 new_fs ? new_fs : current->fs);
193 if (IS_ERR(*new_nsp)) {
194 err = PTR_ERR(*new_nsp);
198 err = ns_cgroup_clone(current);
200 put_nsproxy(*new_nsp);
206 void switch_task_namespaces(struct task_struct *p, struct nsproxy *new)
214 rcu_assign_pointer(p->nsproxy, new);
216 if (ns && atomic_dec_and_test(&ns->count)) {
218 * wait for others to get what they want from this nsproxy.
220 * cannot release this nsproxy via the call_rcu() since
221 * put_mnt_ns() will want to sleep
228 void exit_task_namespaces(struct task_struct *p)
230 switch_task_namespaces(p, NULL);
233 static int __init nsproxy_cache_init(void)
235 nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);
239 module_init(nsproxy_cache_init);