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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
16#include <linux/module.h>
Serge E. Hallynab516012006-10-02 02:18:06 -070017#include <linux/nsproxy.h>
Serge E. Hallyn0437eb52006-10-02 02:18:07 -070018#include <linux/init_task.h>
Kirill Korotaev6b3286e2006-12-08 02:37:56 -080019#include <linux/mnt_namespace.h>
Serge E. Hallyn4865ecf2006-10-02 02:18:14 -070020#include <linux/utsname.h>
Cedric Le Goater9a575a92006-12-08 02:37:59 -080021#include <linux/pid_namespace.h>
Eric W. Biederman9dd776b2007-09-26 22:04:26 -070022#include <net/net_namespace.h>
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -080023#include <linux/ipc_namespace.h>
Serge E. Hallyn0437eb52006-10-02 02:18:07 -070024
Cedric Le Goater98c0d072007-07-15 23:41:07 -070025static struct kmem_cache *nsproxy_cachep;
26
Serge E. Hallyn0437eb52006-10-02 02:18:07 -070027struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
Serge E. Hallynab516012006-10-02 02:18:06 -070028
Alexey Dobriyan90af90d2009-06-17 16:27:56 -070029static inline struct nsproxy *create_nsproxy(void)
Serge E. Hallynab516012006-10-02 02:18:06 -070030{
Alexey Dobriyan90af90d2009-06-17 16:27:56 -070031 struct nsproxy *nsproxy;
Serge E. Hallynab516012006-10-02 02:18:06 -070032
Alexey Dobriyan90af90d2009-06-17 16:27:56 -070033 nsproxy = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL);
34 if (nsproxy)
35 atomic_set(&nsproxy->count, 1);
36 return nsproxy;
Serge E. Hallynab516012006-10-02 02:18:06 -070037}
38
39/*
Badari Pulavartye3222c42007-05-08 00:25:21 -070040 * 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.
Serge E. Hallynab516012006-10-02 02:18:06 -070043 */
Eric W. Biederman213dd262007-07-15 23:41:15 -070044static struct nsproxy *create_new_namespaces(unsigned long flags,
45 struct task_struct *tsk, struct fs_struct *new_fs)
Serge E. Hallynab516012006-10-02 02:18:06 -070046{
Badari Pulavartye3222c42007-05-08 00:25:21 -070047 struct nsproxy *new_nsp;
Cedric Le Goater467e9f42007-07-15 23:41:06 -070048 int err;
Serge E. Hallynab516012006-10-02 02:18:06 -070049
Alexey Dobriyan90af90d2009-06-17 16:27:56 -070050 new_nsp = create_nsproxy();
Badari Pulavartye3222c42007-05-08 00:25:21 -070051 if (!new_nsp)
52 return ERR_PTR(-ENOMEM);
Serge E. Hallyn1651e142006-10-02 02:18:08 -070053
Badari Pulavartye3222c42007-05-08 00:25:21 -070054 new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, new_fs);
Cedric Le Goater467e9f42007-07-15 23:41:06 -070055 if (IS_ERR(new_nsp->mnt_ns)) {
56 err = PTR_ERR(new_nsp->mnt_ns);
Badari Pulavartye3222c42007-05-08 00:25:21 -070057 goto out_ns;
Cedric Le Goater467e9f42007-07-15 23:41:06 -070058 }
Badari Pulavartye3222c42007-05-08 00:25:21 -070059
60 new_nsp->uts_ns = copy_utsname(flags, tsk->nsproxy->uts_ns);
Cedric Le Goater467e9f42007-07-15 23:41:06 -070061 if (IS_ERR(new_nsp->uts_ns)) {
62 err = PTR_ERR(new_nsp->uts_ns);
Badari Pulavartye3222c42007-05-08 00:25:21 -070063 goto out_uts;
Cedric Le Goater467e9f42007-07-15 23:41:06 -070064 }
Badari Pulavartye3222c42007-05-08 00:25:21 -070065
66 new_nsp->ipc_ns = copy_ipcs(flags, tsk->nsproxy->ipc_ns);
Cedric Le Goater467e9f42007-07-15 23:41:06 -070067 if (IS_ERR(new_nsp->ipc_ns)) {
68 err = PTR_ERR(new_nsp->ipc_ns);
Badari Pulavartye3222c42007-05-08 00:25:21 -070069 goto out_ipc;
Cedric Le Goater467e9f42007-07-15 23:41:06 -070070 }
Badari Pulavartye3222c42007-05-08 00:25:21 -070071
Sukadev Bhattiprolu2894d6502007-10-18 23:39:49 -070072 new_nsp->pid_ns = copy_pid_ns(flags, task_active_pid_ns(tsk));
Cedric Le Goater467e9f42007-07-15 23:41:06 -070073 if (IS_ERR(new_nsp->pid_ns)) {
74 err = PTR_ERR(new_nsp->pid_ns);
Badari Pulavartye3222c42007-05-08 00:25:21 -070075 goto out_pid;
Cedric Le Goater467e9f42007-07-15 23:41:06 -070076 }
Badari Pulavartye3222c42007-05-08 00:25:21 -070077
Eric W. Biederman9dd776b2007-09-26 22:04:26 -070078 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);
81 goto out_net;
82 }
83
Badari Pulavartye3222c42007-05-08 00:25:21 -070084 return new_nsp;
85
Eric W. Biederman9dd776b2007-09-26 22:04:26 -070086out_net:
Cedric Le Goateracce2922007-07-15 23:40:59 -070087 if (new_nsp->pid_ns)
88 put_pid_ns(new_nsp->pid_ns);
Badari Pulavartye3222c42007-05-08 00:25:21 -070089out_pid:
90 if (new_nsp->ipc_ns)
91 put_ipc_ns(new_nsp->ipc_ns);
92out_ipc:
93 if (new_nsp->uts_ns)
94 put_uts_ns(new_nsp->uts_ns);
95out_uts:
96 if (new_nsp->mnt_ns)
97 put_mnt_ns(new_nsp->mnt_ns);
98out_ns:
Cedric Le Goater98c0d072007-07-15 23:41:07 -070099 kmem_cache_free(nsproxy_cachep, new_nsp);
Cedric Le Goater467e9f42007-07-15 23:41:06 -0700100 return ERR_PTR(err);
Serge E. Hallynab516012006-10-02 02:18:06 -0700101}
102
103/*
104 * called from clone. This now handles copy for nsproxy and all
105 * namespaces therein.
106 */
Eric W. Biederman213dd262007-07-15 23:41:15 -0700107int copy_namespaces(unsigned long flags, struct task_struct *tsk)
Serge E. Hallynab516012006-10-02 02:18:06 -0700108{
109 struct nsproxy *old_ns = tsk->nsproxy;
Serge E. Hallyn1651e142006-10-02 02:18:08 -0700110 struct nsproxy *new_ns;
111 int err = 0;
Serge E. Hallynab516012006-10-02 02:18:06 -0700112
113 if (!old_ns)
114 return 0;
115
116 get_nsproxy(old_ns);
117
Pavel Emelyanov30e49c22007-10-18 23:40:10 -0700118 if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
Serge Hallyn18b6e042008-10-15 16:38:45 -0500119 CLONE_NEWPID | CLONE_NEWNET)))
Serge E. Hallyn1651e142006-10-02 02:18:08 -0700120 return 0;
121
Badari Pulavartye3222c42007-05-08 00:25:21 -0700122 if (!capable(CAP_SYS_ADMIN)) {
123 err = -EPERM;
124 goto out;
125 }
126
Serge E. Hallyn02fdb362008-04-29 01:01:00 -0700127 /*
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.
133 */
134 if ((flags & CLONE_NEWIPC) && (flags & CLONE_SYSVSEM)) {
135 err = -EINVAL;
136 goto out;
137 }
138
Badari Pulavartye3222c42007-05-08 00:25:21 -0700139 new_ns = create_new_namespaces(flags, tsk, tsk->fs);
140 if (IS_ERR(new_ns)) {
141 err = PTR_ERR(new_ns);
Serge E. Hallyn1651e142006-10-02 02:18:08 -0700142 goto out;
143 }
144
145 tsk->nsproxy = new_ns;
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700146
Serge E. Hallyn1651e142006-10-02 02:18:08 -0700147out:
Linus Torvalds444f3782007-01-30 13:35:18 -0800148 put_nsproxy(old_ns);
Serge E. Hallyn1651e142006-10-02 02:18:08 -0700149 return err;
Serge E. Hallynab516012006-10-02 02:18:06 -0700150}
151
152void free_nsproxy(struct nsproxy *ns)
153{
Cedric Le Goater9a575a92006-12-08 02:37:59 -0800154 if (ns->mnt_ns)
155 put_mnt_ns(ns->mnt_ns);
156 if (ns->uts_ns)
157 put_uts_ns(ns->uts_ns);
158 if (ns->ipc_ns)
159 put_ipc_ns(ns->ipc_ns);
160 if (ns->pid_ns)
161 put_pid_ns(ns->pid_ns);
Eric W. Biederman9dd776b2007-09-26 22:04:26 -0700162 put_net(ns->net_ns);
Cedric Le Goater98c0d072007-07-15 23:41:07 -0700163 kmem_cache_free(nsproxy_cachep, ns);
Serge E. Hallynab516012006-10-02 02:18:06 -0700164}
Badari Pulavartye3222c42007-05-08 00:25:21 -0700165
166/*
167 * Called from unshare. Unshare all the namespaces part of nsproxy.
Cedric Le Goater4e71e4742007-06-23 17:16:25 -0700168 * On success, returns the new nsproxy.
Badari Pulavartye3222c42007-05-08 00:25:21 -0700169 */
170int unshare_nsproxy_namespaces(unsigned long unshare_flags,
171 struct nsproxy **new_nsp, struct fs_struct *new_fs)
172{
Badari Pulavartye3222c42007-05-08 00:25:21 -0700173 int err = 0;
174
Serge E. Hallyn77ec7392007-07-15 23:41:01 -0700175 if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
Serge Hallyn18b6e042008-10-15 16:38:45 -0500176 CLONE_NEWNET)))
Badari Pulavartye3222c42007-05-08 00:25:21 -0700177 return 0;
178
Badari Pulavartye3222c42007-05-08 00:25:21 -0700179 if (!capable(CAP_SYS_ADMIN))
180 return -EPERM;
181
Badari Pulavartye3222c42007-05-08 00:25:21 -0700182 *new_nsp = create_new_namespaces(unshare_flags, current,
183 new_fs ? new_fs : current->fs);
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700184 if (IS_ERR(*new_nsp)) {
Badari Pulavartye3222c42007-05-08 00:25:21 -0700185 err = PTR_ERR(*new_nsp);
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700186 goto out;
187 }
188
Serge E. Hallyne885dcd2008-07-25 01:47:06 -0700189 err = ns_cgroup_clone(current, task_pid(current));
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700190 if (err)
191 put_nsproxy(*new_nsp);
192
193out:
Badari Pulavartye3222c42007-05-08 00:25:21 -0700194 return err;
195}
Cedric Le Goater98c0d072007-07-15 23:41:07 -0700196
Pavel Emelyanovcf7b7082007-10-18 23:39:54 -0700197void switch_task_namespaces(struct task_struct *p, struct nsproxy *new)
198{
199 struct nsproxy *ns;
200
201 might_sleep();
202
203 ns = p->nsproxy;
204
205 rcu_assign_pointer(p->nsproxy, new);
206
207 if (ns && atomic_dec_and_test(&ns->count)) {
208 /*
209 * wait for others to get what they want from this nsproxy.
210 *
211 * cannot release this nsproxy via the call_rcu() since
212 * put_mnt_ns() will want to sleep
213 */
214 synchronize_rcu();
215 free_nsproxy(ns);
216 }
217}
218
219void exit_task_namespaces(struct task_struct *p)
220{
221 switch_task_namespaces(p, NULL);
222}
223
Cedric Le Goater98c0d072007-07-15 23:41:07 -0700224static int __init nsproxy_cache_init(void)
225{
Pavel Emelyanovdb8906d2007-10-16 23:30:11 -0700226 nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);
Cedric Le Goater98c0d072007-07-15 23:41:07 -0700227 return 0;
228}
229
230module_init(nsproxy_cache_init);