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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>
Serge E. Hallynab516012006-10-02 02:18:06 -070017#include <linux/module.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>
Serge E. Hallyn0437eb52006-10-02 02:18:07 -070025
Cedric Le Goater98c0d072007-07-15 23:41:07 -070026static struct kmem_cache *nsproxy_cachep;
27
Alexey Dobriyan84670052010-03-10 15:23:10 -080028struct nsproxy init_nsproxy = {
29 .count = ATOMIC_INIT(1),
30 .uts_ns = &init_uts_ns,
31#if defined(CONFIG_POSIX_MQUEUE) || defined(CONFIG_SYSVIPC)
32 .ipc_ns = &init_ipc_ns,
33#endif
34 .mnt_ns = NULL,
35 .pid_ns = &init_pid_ns,
36#ifdef CONFIG_NET
37 .net_ns = &init_net,
38#endif
39};
Serge E. Hallynab516012006-10-02 02:18:06 -070040
Alexey Dobriyan90af90d2009-06-17 16:27:56 -070041static inline struct nsproxy *create_nsproxy(void)
Serge E. Hallynab516012006-10-02 02:18:06 -070042{
Alexey Dobriyan90af90d2009-06-17 16:27:56 -070043 struct nsproxy *nsproxy;
Serge E. Hallynab516012006-10-02 02:18:06 -070044
Alexey Dobriyan90af90d2009-06-17 16:27:56 -070045 nsproxy = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL);
46 if (nsproxy)
47 atomic_set(&nsproxy->count, 1);
48 return nsproxy;
Serge E. Hallynab516012006-10-02 02:18:06 -070049}
50
51/*
Badari Pulavartye3222c42007-05-08 00:25:21 -070052 * Create new nsproxy and all of its the associated namespaces.
53 * Return the newly created nsproxy. Do not attach this to the task,
54 * leave it to the caller to do proper locking and attach it to task.
Serge E. Hallynab516012006-10-02 02:18:06 -070055 */
Eric W. Biederman213dd262007-07-15 23:41:15 -070056static struct nsproxy *create_new_namespaces(unsigned long flags,
57 struct task_struct *tsk, struct fs_struct *new_fs)
Serge E. Hallynab516012006-10-02 02:18:06 -070058{
Badari Pulavartye3222c42007-05-08 00:25:21 -070059 struct nsproxy *new_nsp;
Cedric Le Goater467e9f42007-07-15 23:41:06 -070060 int err;
Serge E. Hallynab516012006-10-02 02:18:06 -070061
Alexey Dobriyan90af90d2009-06-17 16:27:56 -070062 new_nsp = create_nsproxy();
Badari Pulavartye3222c42007-05-08 00:25:21 -070063 if (!new_nsp)
64 return ERR_PTR(-ENOMEM);
Serge E. Hallyn1651e142006-10-02 02:18:08 -070065
Badari Pulavartye3222c42007-05-08 00:25:21 -070066 new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, new_fs);
Cedric Le Goater467e9f42007-07-15 23:41:06 -070067 if (IS_ERR(new_nsp->mnt_ns)) {
68 err = PTR_ERR(new_nsp->mnt_ns);
Badari Pulavartye3222c42007-05-08 00:25:21 -070069 goto out_ns;
Cedric Le Goater467e9f42007-07-15 23:41:06 -070070 }
Badari Pulavartye3222c42007-05-08 00:25:21 -070071
72 new_nsp->uts_ns = copy_utsname(flags, tsk->nsproxy->uts_ns);
Cedric Le Goater467e9f42007-07-15 23:41:06 -070073 if (IS_ERR(new_nsp->uts_ns)) {
74 err = PTR_ERR(new_nsp->uts_ns);
Badari Pulavartye3222c42007-05-08 00:25:21 -070075 goto out_uts;
Cedric Le Goater467e9f42007-07-15 23:41:06 -070076 }
Badari Pulavartye3222c42007-05-08 00:25:21 -070077
78 new_nsp->ipc_ns = copy_ipcs(flags, tsk->nsproxy->ipc_ns);
Cedric Le Goater467e9f42007-07-15 23:41:06 -070079 if (IS_ERR(new_nsp->ipc_ns)) {
80 err = PTR_ERR(new_nsp->ipc_ns);
Badari Pulavartye3222c42007-05-08 00:25:21 -070081 goto out_ipc;
Cedric Le Goater467e9f42007-07-15 23:41:06 -070082 }
Badari Pulavartye3222c42007-05-08 00:25:21 -070083
Sukadev Bhattiprolu2894d6502007-10-18 23:39:49 -070084 new_nsp->pid_ns = copy_pid_ns(flags, task_active_pid_ns(tsk));
Cedric Le Goater467e9f42007-07-15 23:41:06 -070085 if (IS_ERR(new_nsp->pid_ns)) {
86 err = PTR_ERR(new_nsp->pid_ns);
Badari Pulavartye3222c42007-05-08 00:25:21 -070087 goto out_pid;
Cedric Le Goater467e9f42007-07-15 23:41:06 -070088 }
Badari Pulavartye3222c42007-05-08 00:25:21 -070089
Eric W. Biederman9dd776b2007-09-26 22:04:26 -070090 new_nsp->net_ns = copy_net_ns(flags, tsk->nsproxy->net_ns);
91 if (IS_ERR(new_nsp->net_ns)) {
92 err = PTR_ERR(new_nsp->net_ns);
93 goto out_net;
94 }
95
Badari Pulavartye3222c42007-05-08 00:25:21 -070096 return new_nsp;
97
Eric W. Biederman9dd776b2007-09-26 22:04:26 -070098out_net:
Cedric Le Goateracce2922007-07-15 23:40:59 -070099 if (new_nsp->pid_ns)
100 put_pid_ns(new_nsp->pid_ns);
Badari Pulavartye3222c42007-05-08 00:25:21 -0700101out_pid:
102 if (new_nsp->ipc_ns)
103 put_ipc_ns(new_nsp->ipc_ns);
104out_ipc:
105 if (new_nsp->uts_ns)
106 put_uts_ns(new_nsp->uts_ns);
107out_uts:
108 if (new_nsp->mnt_ns)
109 put_mnt_ns(new_nsp->mnt_ns);
110out_ns:
Cedric Le Goater98c0d072007-07-15 23:41:07 -0700111 kmem_cache_free(nsproxy_cachep, new_nsp);
Cedric Le Goater467e9f42007-07-15 23:41:06 -0700112 return ERR_PTR(err);
Serge E. Hallynab516012006-10-02 02:18:06 -0700113}
114
115/*
116 * called from clone. This now handles copy for nsproxy and all
117 * namespaces therein.
118 */
Eric W. Biederman213dd262007-07-15 23:41:15 -0700119int copy_namespaces(unsigned long flags, struct task_struct *tsk)
Serge E. Hallynab516012006-10-02 02:18:06 -0700120{
121 struct nsproxy *old_ns = tsk->nsproxy;
Serge E. Hallyn1651e142006-10-02 02:18:08 -0700122 struct nsproxy *new_ns;
123 int err = 0;
Serge E. Hallynab516012006-10-02 02:18:06 -0700124
125 if (!old_ns)
126 return 0;
127
128 get_nsproxy(old_ns);
129
Pavel Emelyanov30e49c22007-10-18 23:40:10 -0700130 if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
Serge Hallyn18b6e042008-10-15 16:38:45 -0500131 CLONE_NEWPID | CLONE_NEWNET)))
Serge E. Hallyn1651e142006-10-02 02:18:08 -0700132 return 0;
133
Badari Pulavartye3222c42007-05-08 00:25:21 -0700134 if (!capable(CAP_SYS_ADMIN)) {
135 err = -EPERM;
136 goto out;
137 }
138
Serge E. Hallyn02fdb362008-04-29 01:01:00 -0700139 /*
140 * CLONE_NEWIPC must detach from the undolist: after switching
141 * to a new ipc namespace, the semaphore arrays from the old
142 * namespace are unreachable. In clone parlance, CLONE_SYSVSEM
143 * means share undolist with parent, so we must forbid using
144 * it along with CLONE_NEWIPC.
145 */
146 if ((flags & CLONE_NEWIPC) && (flags & CLONE_SYSVSEM)) {
147 err = -EINVAL;
148 goto out;
149 }
150
Badari Pulavartye3222c42007-05-08 00:25:21 -0700151 new_ns = create_new_namespaces(flags, tsk, tsk->fs);
152 if (IS_ERR(new_ns)) {
153 err = PTR_ERR(new_ns);
Serge E. Hallyn1651e142006-10-02 02:18:08 -0700154 goto out;
155 }
156
157 tsk->nsproxy = new_ns;
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700158
Serge E. Hallyn1651e142006-10-02 02:18:08 -0700159out:
Linus Torvalds444f3782007-01-30 13:35:18 -0800160 put_nsproxy(old_ns);
Serge E. Hallyn1651e142006-10-02 02:18:08 -0700161 return err;
Serge E. Hallynab516012006-10-02 02:18:06 -0700162}
163
164void free_nsproxy(struct nsproxy *ns)
165{
Cedric Le Goater9a575a92006-12-08 02:37:59 -0800166 if (ns->mnt_ns)
167 put_mnt_ns(ns->mnt_ns);
168 if (ns->uts_ns)
169 put_uts_ns(ns->uts_ns);
170 if (ns->ipc_ns)
171 put_ipc_ns(ns->ipc_ns);
172 if (ns->pid_ns)
173 put_pid_ns(ns->pid_ns);
Eric W. Biederman9dd776b2007-09-26 22:04:26 -0700174 put_net(ns->net_ns);
Cedric Le Goater98c0d072007-07-15 23:41:07 -0700175 kmem_cache_free(nsproxy_cachep, ns);
Serge E. Hallynab516012006-10-02 02:18:06 -0700176}
Badari Pulavartye3222c42007-05-08 00:25:21 -0700177
178/*
179 * Called from unshare. Unshare all the namespaces part of nsproxy.
Cedric Le Goater4e71e4742007-06-23 17:16:25 -0700180 * On success, returns the new nsproxy.
Badari Pulavartye3222c42007-05-08 00:25:21 -0700181 */
182int unshare_nsproxy_namespaces(unsigned long unshare_flags,
183 struct nsproxy **new_nsp, struct fs_struct *new_fs)
184{
Badari Pulavartye3222c42007-05-08 00:25:21 -0700185 int err = 0;
186
Serge E. Hallyn77ec7392007-07-15 23:41:01 -0700187 if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
Serge Hallyn18b6e042008-10-15 16:38:45 -0500188 CLONE_NEWNET)))
Badari Pulavartye3222c42007-05-08 00:25:21 -0700189 return 0;
190
Badari Pulavartye3222c42007-05-08 00:25:21 -0700191 if (!capable(CAP_SYS_ADMIN))
192 return -EPERM;
193
Badari Pulavartye3222c42007-05-08 00:25:21 -0700194 *new_nsp = create_new_namespaces(unshare_flags, current,
195 new_fs ? new_fs : current->fs);
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700196 if (IS_ERR(*new_nsp)) {
Badari Pulavartye3222c42007-05-08 00:25:21 -0700197 err = PTR_ERR(*new_nsp);
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700198 goto out;
199 }
200
Serge E. Hallyne885dcd2008-07-25 01:47:06 -0700201 err = ns_cgroup_clone(current, task_pid(current));
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700202 if (err)
203 put_nsproxy(*new_nsp);
204
205out:
Badari Pulavartye3222c42007-05-08 00:25:21 -0700206 return err;
207}
Cedric Le Goater98c0d072007-07-15 23:41:07 -0700208
Pavel Emelyanovcf7b7082007-10-18 23:39:54 -0700209void switch_task_namespaces(struct task_struct *p, struct nsproxy *new)
210{
211 struct nsproxy *ns;
212
213 might_sleep();
214
215 ns = p->nsproxy;
216
217 rcu_assign_pointer(p->nsproxy, new);
218
219 if (ns && atomic_dec_and_test(&ns->count)) {
220 /*
221 * wait for others to get what they want from this nsproxy.
222 *
223 * cannot release this nsproxy via the call_rcu() since
224 * put_mnt_ns() will want to sleep
225 */
226 synchronize_rcu();
227 free_nsproxy(ns);
228 }
229}
230
231void exit_task_namespaces(struct task_struct *p)
232{
233 switch_task_namespaces(p, NULL);
234}
235
Cedric Le Goater98c0d072007-07-15 23:41:07 -0700236static int __init nsproxy_cache_init(void)
237{
Pavel Emelyanovdb8906d2007-10-16 23:30:11 -0700238 nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);
Cedric Le Goater98c0d072007-07-15 23:41:07 -0700239 return 0;
240}
241
242module_init(nsproxy_cache_init);