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/nsproxy.h>
18 #include <linux/init_task.h>
19 #include <linux/mnt_namespace.h>
20 #include <linux/utsname.h>
21 #include <linux/pid_namespace.h>
22 #include <net/net_namespace.h>
23 #include <linux/ipc_namespace.h>
25 static struct kmem_cache
*nsproxy_cachep
;
27 struct nsproxy init_nsproxy
= INIT_NSPROXY(init_nsproxy
);
29 static inline struct nsproxy
*create_nsproxy(void)
31 struct nsproxy
*nsproxy
;
33 nsproxy
= kmem_cache_alloc(nsproxy_cachep
, GFP_KERNEL
);
35 atomic_set(&nsproxy
->count
, 1);
40 * Create new nsproxy and all of its the associated namespaces.
41 * Return the newly created nsproxy. Do not attach this to the task,
42 * leave it to the caller to do proper locking and attach it to task.
44 static struct nsproxy
*create_new_namespaces(unsigned long flags
,
45 struct task_struct
*tsk
, struct fs_struct
*new_fs
)
47 struct nsproxy
*new_nsp
;
50 new_nsp
= create_nsproxy();
52 return ERR_PTR(-ENOMEM
);
54 new_nsp
->mnt_ns
= copy_mnt_ns(flags
, tsk
->nsproxy
->mnt_ns
, new_fs
);
55 if (IS_ERR(new_nsp
->mnt_ns
)) {
56 err
= PTR_ERR(new_nsp
->mnt_ns
);
60 new_nsp
->uts_ns
= copy_utsname(flags
, tsk
->nsproxy
->uts_ns
);
61 if (IS_ERR(new_nsp
->uts_ns
)) {
62 err
= PTR_ERR(new_nsp
->uts_ns
);
66 new_nsp
->ipc_ns
= copy_ipcs(flags
, tsk
->nsproxy
->ipc_ns
);
67 if (IS_ERR(new_nsp
->ipc_ns
)) {
68 err
= PTR_ERR(new_nsp
->ipc_ns
);
72 new_nsp
->pid_ns
= copy_pid_ns(flags
, task_active_pid_ns(tsk
));
73 if (IS_ERR(new_nsp
->pid_ns
)) {
74 err
= PTR_ERR(new_nsp
->pid_ns
);
78 new_nsp
->net_ns
= copy_net_ns(flags
, tsk
->nsproxy
->net_ns
);
79 if (IS_ERR(new_nsp
->net_ns
)) {
80 err
= PTR_ERR(new_nsp
->net_ns
);
88 put_pid_ns(new_nsp
->pid_ns
);
91 put_ipc_ns(new_nsp
->ipc_ns
);
94 put_uts_ns(new_nsp
->uts_ns
);
97 put_mnt_ns(new_nsp
->mnt_ns
);
99 kmem_cache_free(nsproxy_cachep
, new_nsp
);
104 * called from clone. This now handles copy for nsproxy and all
105 * namespaces therein.
107 int copy_namespaces(unsigned long flags
, struct task_struct
*tsk
)
109 struct nsproxy
*old_ns
= tsk
->nsproxy
;
110 struct nsproxy
*new_ns
;
118 if (!(flags
& (CLONE_NEWNS
| CLONE_NEWUTS
| CLONE_NEWIPC
|
119 CLONE_NEWPID
| CLONE_NEWNET
)))
122 if (!capable(CAP_SYS_ADMIN
)) {
128 * CLONE_NEWIPC must detach from the undolist: after switching
129 * to a new ipc namespace, the semaphore arrays from the old
130 * namespace are unreachable. In clone parlance, CLONE_SYSVSEM
131 * means share undolist with parent, so we must forbid using
132 * it along with CLONE_NEWIPC.
134 if ((flags
& CLONE_NEWIPC
) && (flags
& CLONE_SYSVSEM
)) {
139 new_ns
= create_new_namespaces(flags
, tsk
, tsk
->fs
);
140 if (IS_ERR(new_ns
)) {
141 err
= PTR_ERR(new_ns
);
145 tsk
->nsproxy
= new_ns
;
152 void free_nsproxy(struct nsproxy
*ns
)
155 put_mnt_ns(ns
->mnt_ns
);
157 put_uts_ns(ns
->uts_ns
);
159 put_ipc_ns(ns
->ipc_ns
);
161 put_pid_ns(ns
->pid_ns
);
163 kmem_cache_free(nsproxy_cachep
, ns
);
167 * Called from unshare. Unshare all the namespaces part of nsproxy.
168 * On success, returns the new nsproxy.
170 int unshare_nsproxy_namespaces(unsigned long unshare_flags
,
171 struct nsproxy
**new_nsp
, struct fs_struct
*new_fs
)
175 if (!(unshare_flags
& (CLONE_NEWNS
| CLONE_NEWUTS
| CLONE_NEWIPC
|
179 if (!capable(CAP_SYS_ADMIN
))
182 *new_nsp
= create_new_namespaces(unshare_flags
, current
,
183 new_fs
? new_fs
: current
->fs
);
184 if (IS_ERR(*new_nsp
)) {
185 err
= PTR_ERR(*new_nsp
);
189 err
= ns_cgroup_clone(current
, task_pid(current
));
191 put_nsproxy(*new_nsp
);
197 void switch_task_namespaces(struct task_struct
*p
, struct nsproxy
*new)
205 rcu_assign_pointer(p
->nsproxy
, new);
207 if (ns
&& atomic_dec_and_test(&ns
->count
)) {
209 * wait for others to get what they want from this nsproxy.
211 * cannot release this nsproxy via the call_rcu() since
212 * put_mnt_ns() will want to sleep
219 void exit_task_namespaces(struct task_struct
*p
)
221 switch_task_namespaces(p
, NULL
);
224 static int __init
nsproxy_cache_init(void)
226 nsproxy_cachep
= KMEM_CACHE(nsproxy
, SLAB_PANIC
);
230 module_init(nsproxy_cache_init
);
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