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git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/blob - kernel/nsproxy.c
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_ns.h>
26 #include <linux/file.h>
27 #include <linux/syscalls.h>
28 #include <linux/cgroup.h>
30 static struct kmem_cache
*nsproxy_cachep
;
32 struct nsproxy init_nsproxy
= {
33 .count
= ATOMIC_INIT(1),
34 .uts_ns
= &init_uts_ns
,
35 #if defined(CONFIG_POSIX_MQUEUE) || defined(CONFIG_SYSVIPC)
36 .ipc_ns
= &init_ipc_ns
,
39 .pid_ns_for_children
= &init_pid_ns
,
44 .cgroup_ns
= &init_cgroup_ns
,
48 static inline struct nsproxy
*create_nsproxy(void)
50 struct nsproxy
*nsproxy
;
52 nsproxy
= kmem_cache_alloc(nsproxy_cachep
, GFP_KERNEL
);
54 atomic_set(&nsproxy
->count
, 1);
59 * Create new nsproxy and all of its the associated namespaces.
60 * Return the newly created nsproxy. Do not attach this to the task,
61 * leave it to the caller to do proper locking and attach it to task.
63 static struct nsproxy
*create_new_namespaces(unsigned long flags
,
64 struct task_struct
*tsk
, struct user_namespace
*user_ns
,
65 struct fs_struct
*new_fs
)
67 struct nsproxy
*new_nsp
;
70 new_nsp
= create_nsproxy();
72 return ERR_PTR(-ENOMEM
);
74 new_nsp
->mnt_ns
= copy_mnt_ns(flags
, tsk
->nsproxy
->mnt_ns
, user_ns
, new_fs
);
75 if (IS_ERR(new_nsp
->mnt_ns
)) {
76 err
= PTR_ERR(new_nsp
->mnt_ns
);
80 new_nsp
->uts_ns
= copy_utsname(flags
, user_ns
, tsk
->nsproxy
->uts_ns
);
81 if (IS_ERR(new_nsp
->uts_ns
)) {
82 err
= PTR_ERR(new_nsp
->uts_ns
);
86 new_nsp
->ipc_ns
= copy_ipcs(flags
, user_ns
, tsk
->nsproxy
->ipc_ns
);
87 if (IS_ERR(new_nsp
->ipc_ns
)) {
88 err
= PTR_ERR(new_nsp
->ipc_ns
);
92 new_nsp
->pid_ns_for_children
=
93 copy_pid_ns(flags
, user_ns
, tsk
->nsproxy
->pid_ns_for_children
);
94 if (IS_ERR(new_nsp
->pid_ns_for_children
)) {
95 err
= PTR_ERR(new_nsp
->pid_ns_for_children
);
99 new_nsp
->cgroup_ns
= copy_cgroup_ns(flags
, user_ns
,
100 tsk
->nsproxy
->cgroup_ns
);
101 if (IS_ERR(new_nsp
->cgroup_ns
)) {
102 err
= PTR_ERR(new_nsp
->cgroup_ns
);
106 new_nsp
->net_ns
= copy_net_ns(flags
, user_ns
, tsk
->nsproxy
->net_ns
);
107 if (IS_ERR(new_nsp
->net_ns
)) {
108 err
= PTR_ERR(new_nsp
->net_ns
);
115 put_cgroup_ns(new_nsp
->cgroup_ns
);
117 if (new_nsp
->pid_ns_for_children
)
118 put_pid_ns(new_nsp
->pid_ns_for_children
);
121 put_ipc_ns(new_nsp
->ipc_ns
);
124 put_uts_ns(new_nsp
->uts_ns
);
127 put_mnt_ns(new_nsp
->mnt_ns
);
129 kmem_cache_free(nsproxy_cachep
, new_nsp
);
134 * called from clone. This now handles copy for nsproxy and all
135 * namespaces therein.
137 int copy_namespaces(unsigned long flags
, struct task_struct
*tsk
)
139 struct nsproxy
*old_ns
= tsk
->nsproxy
;
140 struct user_namespace
*user_ns
= task_cred_xxx(tsk
, user_ns
);
141 struct nsproxy
*new_ns
;
143 if (likely(!(flags
& (CLONE_NEWNS
| CLONE_NEWUTS
| CLONE_NEWIPC
|
144 CLONE_NEWPID
| CLONE_NEWNET
|
145 CLONE_NEWCGROUP
)))) {
150 if (!ns_capable(user_ns
, CAP_SYS_ADMIN
))
154 * CLONE_NEWIPC must detach from the undolist: after switching
155 * to a new ipc namespace, the semaphore arrays from the old
156 * namespace are unreachable. In clone parlance, CLONE_SYSVSEM
157 * means share undolist with parent, so we must forbid using
158 * it along with CLONE_NEWIPC.
160 if ((flags
& (CLONE_NEWIPC
| CLONE_SYSVSEM
)) ==
161 (CLONE_NEWIPC
| CLONE_SYSVSEM
))
164 new_ns
= create_new_namespaces(flags
, tsk
, user_ns
, tsk
->fs
);
166 return PTR_ERR(new_ns
);
168 tsk
->nsproxy
= new_ns
;
172 void free_nsproxy(struct nsproxy
*ns
)
175 put_mnt_ns(ns
->mnt_ns
);
177 put_uts_ns(ns
->uts_ns
);
179 put_ipc_ns(ns
->ipc_ns
);
180 if (ns
->pid_ns_for_children
)
181 put_pid_ns(ns
->pid_ns_for_children
);
182 put_cgroup_ns(ns
->cgroup_ns
);
184 kmem_cache_free(nsproxy_cachep
, ns
);
188 * Called from unshare. Unshare all the namespaces part of nsproxy.
189 * On success, returns the new nsproxy.
191 int unshare_nsproxy_namespaces(unsigned long unshare_flags
,
192 struct nsproxy
**new_nsp
, struct cred
*new_cred
, struct fs_struct
*new_fs
)
194 struct user_namespace
*user_ns
;
197 if (!(unshare_flags
& (CLONE_NEWNS
| CLONE_NEWUTS
| CLONE_NEWIPC
|
198 CLONE_NEWNET
| CLONE_NEWPID
| CLONE_NEWCGROUP
)))
201 user_ns
= new_cred
? new_cred
->user_ns
: current_user_ns();
202 if (!ns_capable(user_ns
, CAP_SYS_ADMIN
))
205 *new_nsp
= create_new_namespaces(unshare_flags
, current
, user_ns
,
206 new_fs
? new_fs
: current
->fs
);
207 if (IS_ERR(*new_nsp
)) {
208 err
= PTR_ERR(*new_nsp
);
216 void switch_task_namespaces(struct task_struct
*p
, struct nsproxy
*new)
227 if (ns
&& atomic_dec_and_test(&ns
->count
))
231 void exit_task_namespaces(struct task_struct
*p
)
233 switch_task_namespaces(p
, NULL
);
236 SYSCALL_DEFINE2(setns
, int, fd
, int, nstype
)
238 struct task_struct
*tsk
= current
;
239 struct nsproxy
*new_nsproxy
;
241 struct ns_common
*ns
;
244 file
= proc_ns_fget(fd
);
246 return PTR_ERR(file
);
249 ns
= get_proc_ns(file_inode(file
));
250 if (nstype
&& (ns
->ops
->type
!= nstype
))
253 new_nsproxy
= create_new_namespaces(0, tsk
, current_user_ns(), tsk
->fs
);
254 if (IS_ERR(new_nsproxy
)) {
255 err
= PTR_ERR(new_nsproxy
);
259 err
= ns
->ops
->install(new_nsproxy
, ns
);
261 free_nsproxy(new_nsproxy
);
264 switch_task_namespaces(tsk
, new_nsproxy
);
270 int __init
nsproxy_cache_init(void)
272 nsproxy_cachep
= KMEM_CACHE(nsproxy
, SLAB_PANIC
);