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/export.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>
24 #include <linux/ipc_namespace.h>
25 #include <linux/proc_fs.h>
26 #include <linux/file.h>
27 #include <linux/syscalls.h>
29 static struct kmem_cache
*nsproxy_cachep
;
31 struct nsproxy init_nsproxy
= {
32 .count
= ATOMIC_INIT(1),
33 .uts_ns
= &init_uts_ns
,
34 #if defined(CONFIG_POSIX_MQUEUE) || defined(CONFIG_SYSVIPC)
35 .ipc_ns
= &init_ipc_ns
,
38 .pid_ns
= &init_pid_ns
,
44 static inline struct nsproxy
*create_nsproxy(void)
46 struct nsproxy
*nsproxy
;
48 nsproxy
= kmem_cache_alloc(nsproxy_cachep
, GFP_KERNEL
);
50 atomic_set(&nsproxy
->count
, 1);
55 * Create new nsproxy and all of its the associated namespaces.
56 * Return the newly created nsproxy. Do not attach this to the task,
57 * leave it to the caller to do proper locking and attach it to task.
59 static struct nsproxy
*create_new_namespaces(unsigned long flags
,
60 struct task_struct
*tsk
, struct fs_struct
*new_fs
)
62 struct nsproxy
*new_nsp
;
65 new_nsp
= create_nsproxy();
67 return ERR_PTR(-ENOMEM
);
69 new_nsp
->mnt_ns
= copy_mnt_ns(flags
, tsk
->nsproxy
->mnt_ns
, new_fs
);
70 if (IS_ERR(new_nsp
->mnt_ns
)) {
71 err
= PTR_ERR(new_nsp
->mnt_ns
);
75 new_nsp
->uts_ns
= copy_utsname(flags
, tsk
);
76 if (IS_ERR(new_nsp
->uts_ns
)) {
77 err
= PTR_ERR(new_nsp
->uts_ns
);
81 new_nsp
->ipc_ns
= copy_ipcs(flags
, tsk
);
82 if (IS_ERR(new_nsp
->ipc_ns
)) {
83 err
= PTR_ERR(new_nsp
->ipc_ns
);
87 new_nsp
->pid_ns
= copy_pid_ns(flags
, task_active_pid_ns(tsk
));
88 if (IS_ERR(new_nsp
->pid_ns
)) {
89 err
= PTR_ERR(new_nsp
->pid_ns
);
93 new_nsp
->net_ns
= copy_net_ns(flags
, tsk
->nsproxy
->net_ns
);
94 if (IS_ERR(new_nsp
->net_ns
)) {
95 err
= PTR_ERR(new_nsp
->net_ns
);
103 put_pid_ns(new_nsp
->pid_ns
);
106 put_ipc_ns(new_nsp
->ipc_ns
);
109 put_uts_ns(new_nsp
->uts_ns
);
112 put_mnt_ns(new_nsp
->mnt_ns
);
114 kmem_cache_free(nsproxy_cachep
, new_nsp
);
119 * called from clone. This now handles copy for nsproxy and all
120 * namespaces therein.
122 int copy_namespaces(unsigned long flags
, struct task_struct
*tsk
)
124 struct nsproxy
*old_ns
= tsk
->nsproxy
;
125 struct nsproxy
*new_ns
;
133 if (!(flags
& (CLONE_NEWNS
| CLONE_NEWUTS
| CLONE_NEWIPC
|
134 CLONE_NEWPID
| CLONE_NEWNET
)))
137 if (!capable(CAP_SYS_ADMIN
)) {
143 * CLONE_NEWIPC must detach from the undolist: after switching
144 * to a new ipc namespace, the semaphore arrays from the old
145 * namespace are unreachable. In clone parlance, CLONE_SYSVSEM
146 * means share undolist with parent, so we must forbid using
147 * it along with CLONE_NEWIPC.
149 if ((flags
& CLONE_NEWIPC
) && (flags
& CLONE_SYSVSEM
)) {
154 new_ns
= create_new_namespaces(flags
, tsk
, tsk
->fs
);
155 if (IS_ERR(new_ns
)) {
156 err
= PTR_ERR(new_ns
);
160 tsk
->nsproxy
= new_ns
;
167 void free_nsproxy(struct nsproxy
*ns
)
170 put_mnt_ns(ns
->mnt_ns
);
172 put_uts_ns(ns
->uts_ns
);
174 put_ipc_ns(ns
->ipc_ns
);
176 put_pid_ns(ns
->pid_ns
);
178 kmem_cache_free(nsproxy_cachep
, ns
);
182 * Called from unshare. Unshare all the namespaces part of nsproxy.
183 * On success, returns the new nsproxy.
185 int unshare_nsproxy_namespaces(unsigned long unshare_flags
,
186 struct nsproxy
**new_nsp
, struct fs_struct
*new_fs
)
190 if (!(unshare_flags
& (CLONE_NEWNS
| CLONE_NEWUTS
| CLONE_NEWIPC
|
194 if (!capable(CAP_SYS_ADMIN
))
197 *new_nsp
= create_new_namespaces(unshare_flags
, current
,
198 new_fs
? new_fs
: current
->fs
);
199 if (IS_ERR(*new_nsp
)) {
200 err
= PTR_ERR(*new_nsp
);
208 void switch_task_namespaces(struct task_struct
*p
, struct nsproxy
*new)
216 rcu_assign_pointer(p
->nsproxy
, new);
218 if (ns
&& atomic_dec_and_test(&ns
->count
)) {
220 * wait for others to get what they want from this nsproxy.
222 * cannot release this nsproxy via the call_rcu() since
223 * put_mnt_ns() will want to sleep
230 void exit_task_namespaces(struct task_struct
*p
)
232 switch_task_namespaces(p
, NULL
);
235 SYSCALL_DEFINE2(setns
, int, fd
, int, nstype
)
237 const struct proc_ns_operations
*ops
;
238 struct task_struct
*tsk
= current
;
239 struct nsproxy
*new_nsproxy
;
240 struct proc_inode
*ei
;
244 if (!capable(CAP_SYS_ADMIN
))
247 file
= proc_ns_fget(fd
);
249 return PTR_ERR(file
);
252 ei
= PROC_I(file
->f_dentry
->d_inode
);
254 if (nstype
&& (ops
->type
!= nstype
))
257 new_nsproxy
= create_new_namespaces(0, tsk
, tsk
->fs
);
258 if (IS_ERR(new_nsproxy
)) {
259 err
= PTR_ERR(new_nsproxy
);
263 err
= ops
->install(new_nsproxy
, ei
->ns
);
265 free_nsproxy(new_nsproxy
);
268 switch_task_namespaces(tsk
, new_nsproxy
);
274 int __init
nsproxy_cache_init(void)
276 nsproxy_cachep
= KMEM_CACHE(nsproxy
, SLAB_PANIC
);