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/slab.h>
17 #include <linux/module.h>
18 #include <linux/syslog.h>
19 #include <linux/nsproxy.h>
20 #include <linux/init_task.h>
21 #include <linux/mnt_namespace.h>
22 #include <linux/utsname.h>
23 #include <linux/pid_namespace.h>
24 #include <net/net_namespace.h>
25 #include <linux/ipc_namespace.h>
27 static struct kmem_cache *nsproxy_cachep;
29 struct nsproxy init_nsproxy = {
30 .count = ATOMIC_INIT(1),
31 .uts_ns = &init_uts_ns,
32 #if defined(CONFIG_POSIX_MQUEUE) || defined(CONFIG_SYSVIPC)
33 .ipc_ns = &init_ipc_ns,
36 .pid_ns = &init_pid_ns,
42 static inline struct nsproxy *create_nsproxy(void)
44 struct nsproxy *nsproxy;
46 nsproxy = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL);
48 atomic_set(&nsproxy->count, 1);
53 * Create new nsproxy and all of its the associated namespaces.
54 * Return the newly created nsproxy. Do not attach this to the task,
55 * leave it to the caller to do proper locking and attach it to task.
57 static struct nsproxy *create_new_namespaces(unsigned long flags,
58 struct task_struct *tsk, struct fs_struct *new_fs)
60 struct nsproxy *new_nsp;
63 new_nsp = create_nsproxy();
65 return ERR_PTR(-ENOMEM);
67 new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, new_fs);
68 if (IS_ERR(new_nsp->mnt_ns)) {
69 err = PTR_ERR(new_nsp->mnt_ns);
73 new_nsp->uts_ns = copy_utsname(flags, tsk->nsproxy->uts_ns);
74 if (IS_ERR(new_nsp->uts_ns)) {
75 err = PTR_ERR(new_nsp->uts_ns);
79 new_nsp->ipc_ns = copy_ipcs(flags, tsk->nsproxy->ipc_ns);
80 if (IS_ERR(new_nsp->ipc_ns)) {
81 err = PTR_ERR(new_nsp->ipc_ns);
85 new_nsp->pid_ns = copy_pid_ns(flags, task_active_pid_ns(tsk));
86 if (IS_ERR(new_nsp->pid_ns)) {
87 err = PTR_ERR(new_nsp->pid_ns);
91 new_nsp->net_ns = copy_net_ns(flags, tsk->nsproxy->net_ns);
92 if (IS_ERR(new_nsp->net_ns)) {
93 err = PTR_ERR(new_nsp->net_ns);
97 new_nsp->syslog_ns = copy_syslog_ns(flags, tsk->nsproxy->syslog_ns);
98 if (IS_ERR(new_nsp->syslog_ns)) {
99 err = PTR_ERR(new_nsp->syslog_ns);
107 put_net(new_nsp->net_ns);
110 put_pid_ns(new_nsp->pid_ns);
113 put_ipc_ns(new_nsp->ipc_ns);
116 put_uts_ns(new_nsp->uts_ns);
119 put_mnt_ns(new_nsp->mnt_ns);
121 kmem_cache_free(nsproxy_cachep, new_nsp);
126 * called from clone. This now handles copy for nsproxy and all
127 * namespaces therein.
129 int copy_namespaces(unsigned long flags, struct task_struct *tsk)
131 struct nsproxy *old_ns = tsk->nsproxy;
132 struct nsproxy *new_ns;
140 if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
141 CLONE_NEWPID | CLONE_NEWNET)))
144 if (!capable(CAP_SYS_ADMIN)) {
150 * CLONE_NEWIPC must detach from the undolist: after switching
151 * to a new ipc namespace, the semaphore arrays from the old
152 * namespace are unreachable. In clone parlance, CLONE_SYSVSEM
153 * means share undolist with parent, so we must forbid using
154 * it along with CLONE_NEWIPC.
156 if ((flags & CLONE_NEWIPC) && (flags & CLONE_SYSVSEM)) {
161 new_ns = create_new_namespaces(flags, tsk, tsk->fs);
162 if (IS_ERR(new_ns)) {
163 err = PTR_ERR(new_ns);
167 tsk->nsproxy = new_ns;
174 void free_nsproxy(struct nsproxy *ns)
177 put_syslog_ns(ns->syslog_ns);
179 put_mnt_ns(ns->mnt_ns);
181 put_uts_ns(ns->uts_ns);
183 put_ipc_ns(ns->ipc_ns);
185 put_pid_ns(ns->pid_ns);
187 kmem_cache_free(nsproxy_cachep, ns);
191 * Called from unshare. Unshare all the namespaces part of nsproxy.
192 * On success, returns the new nsproxy.
194 int unshare_nsproxy_namespaces(unsigned long unshare_flags,
195 struct nsproxy **new_nsp, struct fs_struct *new_fs)
199 if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
203 if (!capable(CAP_SYS_ADMIN))
206 *new_nsp = create_new_namespaces(unshare_flags, current,
207 new_fs ? new_fs : current->fs);
208 if (IS_ERR(*new_nsp)) {
209 err = PTR_ERR(*new_nsp);
213 err = ns_cgroup_clone(current, task_pid(current));
215 put_nsproxy(*new_nsp);
221 void switch_task_namespaces(struct task_struct *p, struct nsproxy *new)
229 rcu_assign_pointer(p->nsproxy, new);
231 if (ns && atomic_dec_and_test(&ns->count)) {
233 * wait for others to get what they want from this nsproxy.
235 * cannot release this nsproxy via the call_rcu() since
236 * put_mnt_ns() will want to sleep
243 void exit_task_namespaces(struct task_struct *p)
245 switch_task_namespaces(p, NULL);
248 static int __init nsproxy_cache_init(void)
250 nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);
254 module_init(nsproxy_cache_init);