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Serge E. Hallynab516012006-10-02 02:18:06 -07001/*
2 * Copyright (C) 2006 IBM Corporation
3 *
4 * Author: Serge Hallyn <serue@us.ibm.com>
5 *
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
9 * License.
Kirill Korotaev25b21cb2006-10-02 02:18:19 -070010 *
11 * Jun 2006 - namespaces support
12 * OpenVZ, SWsoft Inc.
13 * Pavel Emelianov <xemul@openvz.org>
Serge E. Hallynab516012006-10-02 02:18:06 -070014 */
15
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090016#include <linux/slab.h>
Paul Gortmaker9984de12011-05-23 14:51:41 -040017#include <linux/export.h>
Serge E. Hallynab516012006-10-02 02:18:06 -070018#include <linux/nsproxy.h>
Serge E. Hallyn0437eb52006-10-02 02:18:07 -070019#include <linux/init_task.h>
Kirill Korotaev6b3286e2006-12-08 02:37:56 -080020#include <linux/mnt_namespace.h>
Serge E. Hallyn4865ecf2006-10-02 02:18:14 -070021#include <linux/utsname.h>
Cedric Le Goater9a575a92006-12-08 02:37:59 -080022#include <linux/pid_namespace.h>
Eric W. Biederman9dd776b2007-09-26 22:04:26 -070023#include <net/net_namespace.h>
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -080024#include <linux/ipc_namespace.h>
Eric W. Biederman0663c6f2010-03-07 17:48:52 -080025#include <linux/proc_fs.h>
26#include <linux/file.h>
27#include <linux/syscalls.h>
Serge E. Hallyn0437eb52006-10-02 02:18:07 -070028
Cedric Le Goater98c0d072007-07-15 23:41:07 -070029static struct kmem_cache *nsproxy_cachep;
30
Alexey Dobriyan84670052010-03-10 15:23:10 -080031struct 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,
36#endif
37 .mnt_ns = NULL,
38 .pid_ns = &init_pid_ns,
39#ifdef CONFIG_NET
40 .net_ns = &init_net,
41#endif
42};
Serge E. Hallynab516012006-10-02 02:18:06 -070043
Alexey Dobriyan90af90d2009-06-17 16:27:56 -070044static inline struct nsproxy *create_nsproxy(void)
Serge E. Hallynab516012006-10-02 02:18:06 -070045{
Alexey Dobriyan90af90d2009-06-17 16:27:56 -070046 struct nsproxy *nsproxy;
Serge E. Hallynab516012006-10-02 02:18:06 -070047
Alexey Dobriyan90af90d2009-06-17 16:27:56 -070048 nsproxy = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL);
49 if (nsproxy)
50 atomic_set(&nsproxy->count, 1);
51 return nsproxy;
Serge E. Hallynab516012006-10-02 02:18:06 -070052}
53
54/*
Badari Pulavartye3222c42007-05-08 00:25:21 -070055 * 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.
Serge E. Hallynab516012006-10-02 02:18:06 -070058 */
Eric W. Biederman213dd262007-07-15 23:41:15 -070059static struct nsproxy *create_new_namespaces(unsigned long flags,
60 struct task_struct *tsk, struct fs_struct *new_fs)
Serge E. Hallynab516012006-10-02 02:18:06 -070061{
Badari Pulavartye3222c42007-05-08 00:25:21 -070062 struct nsproxy *new_nsp;
Cedric Le Goater467e9f42007-07-15 23:41:06 -070063 int err;
Serge E. Hallynab516012006-10-02 02:18:06 -070064
Alexey Dobriyan90af90d2009-06-17 16:27:56 -070065 new_nsp = create_nsproxy();
Badari Pulavartye3222c42007-05-08 00:25:21 -070066 if (!new_nsp)
67 return ERR_PTR(-ENOMEM);
Serge E. Hallyn1651e142006-10-02 02:18:08 -070068
Badari Pulavartye3222c42007-05-08 00:25:21 -070069 new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, new_fs);
Cedric Le Goater467e9f42007-07-15 23:41:06 -070070 if (IS_ERR(new_nsp->mnt_ns)) {
71 err = PTR_ERR(new_nsp->mnt_ns);
Badari Pulavartye3222c42007-05-08 00:25:21 -070072 goto out_ns;
Cedric Le Goater467e9f42007-07-15 23:41:06 -070073 }
Badari Pulavartye3222c42007-05-08 00:25:21 -070074
Serge E. Hallynbb96a6f2011-03-23 16:43:18 -070075 new_nsp->uts_ns = copy_utsname(flags, tsk);
Cedric Le Goater467e9f42007-07-15 23:41:06 -070076 if (IS_ERR(new_nsp->uts_ns)) {
77 err = PTR_ERR(new_nsp->uts_ns);
Badari Pulavartye3222c42007-05-08 00:25:21 -070078 goto out_uts;
Cedric Le Goater467e9f42007-07-15 23:41:06 -070079 }
Badari Pulavartye3222c42007-05-08 00:25:21 -070080
Serge E. Hallynb0e77592011-03-23 16:43:24 -070081 new_nsp->ipc_ns = copy_ipcs(flags, tsk);
Cedric Le Goater467e9f42007-07-15 23:41:06 -070082 if (IS_ERR(new_nsp->ipc_ns)) {
83 err = PTR_ERR(new_nsp->ipc_ns);
Badari Pulavartye3222c42007-05-08 00:25:21 -070084 goto out_ipc;
Cedric Le Goater467e9f42007-07-15 23:41:06 -070085 }
Badari Pulavartye3222c42007-05-08 00:25:21 -070086
Sukadev Bhattiprolu2894d6502007-10-18 23:39:49 -070087 new_nsp->pid_ns = copy_pid_ns(flags, task_active_pid_ns(tsk));
Cedric Le Goater467e9f42007-07-15 23:41:06 -070088 if (IS_ERR(new_nsp->pid_ns)) {
89 err = PTR_ERR(new_nsp->pid_ns);
Badari Pulavartye3222c42007-05-08 00:25:21 -070090 goto out_pid;
Cedric Le Goater467e9f42007-07-15 23:41:06 -070091 }
Badari Pulavartye3222c42007-05-08 00:25:21 -070092
Eric W. Biederman9dd776b2007-09-26 22:04:26 -070093 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);
96 goto out_net;
97 }
98
Badari Pulavartye3222c42007-05-08 00:25:21 -070099 return new_nsp;
100
Eric W. Biederman9dd776b2007-09-26 22:04:26 -0700101out_net:
Cedric Le Goateracce2922007-07-15 23:40:59 -0700102 if (new_nsp->pid_ns)
103 put_pid_ns(new_nsp->pid_ns);
Badari Pulavartye3222c42007-05-08 00:25:21 -0700104out_pid:
105 if (new_nsp->ipc_ns)
106 put_ipc_ns(new_nsp->ipc_ns);
107out_ipc:
108 if (new_nsp->uts_ns)
109 put_uts_ns(new_nsp->uts_ns);
110out_uts:
111 if (new_nsp->mnt_ns)
112 put_mnt_ns(new_nsp->mnt_ns);
113out_ns:
Cedric Le Goater98c0d072007-07-15 23:41:07 -0700114 kmem_cache_free(nsproxy_cachep, new_nsp);
Cedric Le Goater467e9f42007-07-15 23:41:06 -0700115 return ERR_PTR(err);
Serge E. Hallynab516012006-10-02 02:18:06 -0700116}
117
118/*
119 * called from clone. This now handles copy for nsproxy and all
120 * namespaces therein.
121 */
Eric W. Biederman213dd262007-07-15 23:41:15 -0700122int copy_namespaces(unsigned long flags, struct task_struct *tsk)
Serge E. Hallynab516012006-10-02 02:18:06 -0700123{
124 struct nsproxy *old_ns = tsk->nsproxy;
Serge E. Hallyn1651e142006-10-02 02:18:08 -0700125 struct nsproxy *new_ns;
126 int err = 0;
Serge E. Hallynab516012006-10-02 02:18:06 -0700127
128 if (!old_ns)
129 return 0;
130
131 get_nsproxy(old_ns);
132
Pavel Emelyanov30e49c22007-10-18 23:40:10 -0700133 if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
Serge Hallyn18b6e042008-10-15 16:38:45 -0500134 CLONE_NEWPID | CLONE_NEWNET)))
Serge E. Hallyn1651e142006-10-02 02:18:08 -0700135 return 0;
136
Badari Pulavartye3222c42007-05-08 00:25:21 -0700137 if (!capable(CAP_SYS_ADMIN)) {
138 err = -EPERM;
139 goto out;
140 }
141
Serge E. Hallyn02fdb362008-04-29 01:01:00 -0700142 /*
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.
148 */
149 if ((flags & CLONE_NEWIPC) && (flags & CLONE_SYSVSEM)) {
150 err = -EINVAL;
151 goto out;
152 }
153
Badari Pulavartye3222c42007-05-08 00:25:21 -0700154 new_ns = create_new_namespaces(flags, tsk, tsk->fs);
155 if (IS_ERR(new_ns)) {
156 err = PTR_ERR(new_ns);
Serge E. Hallyn1651e142006-10-02 02:18:08 -0700157 goto out;
158 }
159
160 tsk->nsproxy = new_ns;
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700161
Serge E. Hallyn1651e142006-10-02 02:18:08 -0700162out:
Linus Torvalds444f3782007-01-30 13:35:18 -0800163 put_nsproxy(old_ns);
Serge E. Hallyn1651e142006-10-02 02:18:08 -0700164 return err;
Serge E. Hallynab516012006-10-02 02:18:06 -0700165}
166
167void free_nsproxy(struct nsproxy *ns)
168{
Cedric Le Goater9a575a92006-12-08 02:37:59 -0800169 if (ns->mnt_ns)
170 put_mnt_ns(ns->mnt_ns);
171 if (ns->uts_ns)
172 put_uts_ns(ns->uts_ns);
173 if (ns->ipc_ns)
174 put_ipc_ns(ns->ipc_ns);
175 if (ns->pid_ns)
176 put_pid_ns(ns->pid_ns);
Eric W. Biederman9dd776b2007-09-26 22:04:26 -0700177 put_net(ns->net_ns);
Cedric Le Goater98c0d072007-07-15 23:41:07 -0700178 kmem_cache_free(nsproxy_cachep, ns);
Serge E. Hallynab516012006-10-02 02:18:06 -0700179}
Badari Pulavartye3222c42007-05-08 00:25:21 -0700180
181/*
182 * Called from unshare. Unshare all the namespaces part of nsproxy.
Cedric Le Goater4e71e4742007-06-23 17:16:25 -0700183 * On success, returns the new nsproxy.
Badari Pulavartye3222c42007-05-08 00:25:21 -0700184 */
185int unshare_nsproxy_namespaces(unsigned long unshare_flags,
186 struct nsproxy **new_nsp, struct fs_struct *new_fs)
187{
Badari Pulavartye3222c42007-05-08 00:25:21 -0700188 int err = 0;
189
Serge E. Hallyn77ec7392007-07-15 23:41:01 -0700190 if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
Serge Hallyn18b6e042008-10-15 16:38:45 -0500191 CLONE_NEWNET)))
Badari Pulavartye3222c42007-05-08 00:25:21 -0700192 return 0;
193
Badari Pulavartye3222c42007-05-08 00:25:21 -0700194 if (!capable(CAP_SYS_ADMIN))
195 return -EPERM;
196
Badari Pulavartye3222c42007-05-08 00:25:21 -0700197 *new_nsp = create_new_namespaces(unshare_flags, current,
198 new_fs ? new_fs : current->fs);
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700199 if (IS_ERR(*new_nsp)) {
Badari Pulavartye3222c42007-05-08 00:25:21 -0700200 err = PTR_ERR(*new_nsp);
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700201 goto out;
202 }
203
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700204out:
Badari Pulavartye3222c42007-05-08 00:25:21 -0700205 return err;
206}
Cedric Le Goater98c0d072007-07-15 23:41:07 -0700207
Pavel Emelyanovcf7b7082007-10-18 23:39:54 -0700208void switch_task_namespaces(struct task_struct *p, struct nsproxy *new)
209{
210 struct nsproxy *ns;
211
212 might_sleep();
213
214 ns = p->nsproxy;
215
216 rcu_assign_pointer(p->nsproxy, new);
217
218 if (ns && atomic_dec_and_test(&ns->count)) {
219 /*
220 * wait for others to get what they want from this nsproxy.
221 *
222 * cannot release this nsproxy via the call_rcu() since
223 * put_mnt_ns() will want to sleep
224 */
225 synchronize_rcu();
226 free_nsproxy(ns);
227 }
228}
229
230void exit_task_namespaces(struct task_struct *p)
231{
232 switch_task_namespaces(p, NULL);
233}
234
Eric W. Biederman0663c6f2010-03-07 17:48:52 -0800235SYSCALL_DEFINE2(setns, int, fd, int, nstype)
236{
237 const struct proc_ns_operations *ops;
238 struct task_struct *tsk = current;
239 struct nsproxy *new_nsproxy;
240 struct proc_inode *ei;
241 struct file *file;
242 int err;
243
244 if (!capable(CAP_SYS_ADMIN))
245 return -EPERM;
246
247 file = proc_ns_fget(fd);
248 if (IS_ERR(file))
249 return PTR_ERR(file);
250
251 err = -EINVAL;
252 ei = PROC_I(file->f_dentry->d_inode);
253 ops = ei->ns_ops;
254 if (nstype && (ops->type != nstype))
255 goto out;
256
257 new_nsproxy = create_new_namespaces(0, tsk, tsk->fs);
258 if (IS_ERR(new_nsproxy)) {
259 err = PTR_ERR(new_nsproxy);
260 goto out;
261 }
262
263 err = ops->install(new_nsproxy, ei->ns);
264 if (err) {
265 free_nsproxy(new_nsproxy);
266 goto out;
267 }
268 switch_task_namespaces(tsk, new_nsproxy);
269out:
270 fput(file);
271 return err;
272}
273
Al Viro66577192011-06-28 15:41:10 -0400274int __init nsproxy_cache_init(void)
Cedric Le Goater98c0d072007-07-15 23:41:07 -0700275{
Pavel Emelyanovdb8906d2007-10-16 23:30:11 -0700276 nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);
Cedric Le Goater98c0d072007-07-15 23:41:07 -0700277 return 0;
278}