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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>
17#include <linux/version.h>
18#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>
Serge E. Hallyn0437eb52006-10-02 02:18:07 -070023
24struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
Serge E. Hallynab516012006-10-02 02:18:06 -070025
26static inline void get_nsproxy(struct nsproxy *ns)
27{
28 atomic_inc(&ns->count);
29}
30
31void get_task_namespaces(struct task_struct *tsk)
32{
33 struct nsproxy *ns = tsk->nsproxy;
34 if (ns) {
35 get_nsproxy(ns);
36 }
37}
38
39/*
40 * creates a copy of "orig" with refcount 1.
Serge E. Hallynab516012006-10-02 02:18:06 -070041 */
Badari Pulavartye3222c42007-05-08 00:25:21 -070042static inline struct nsproxy *clone_nsproxy(struct nsproxy *orig)
Serge E. Hallynab516012006-10-02 02:18:06 -070043{
44 struct nsproxy *ns;
45
Alexey Dobriyane05d7222006-10-19 23:29:12 -070046 ns = kmemdup(orig, sizeof(struct nsproxy), GFP_KERNEL);
Eric W. Biederman5f8442e2006-12-13 00:34:04 -080047 if (ns)
Serge E. Hallynab516012006-10-02 02:18:06 -070048 atomic_set(&ns->count, 1);
Serge E. Hallynab516012006-10-02 02:18:06 -070049 return ns;
50}
51
52/*
Badari Pulavartye3222c42007-05-08 00:25:21 -070053 * Create new nsproxy and all of its the associated namespaces.
54 * Return the newly created nsproxy. Do not attach this to the task,
55 * leave it to the caller to do proper locking and attach it to task.
Serge E. Hallynab516012006-10-02 02:18:06 -070056 */
Badari Pulavartye3222c42007-05-08 00:25:21 -070057static struct nsproxy *create_new_namespaces(int flags, struct task_struct *tsk,
58 struct fs_struct *new_fs)
Serge E. Hallynab516012006-10-02 02:18:06 -070059{
Badari Pulavartye3222c42007-05-08 00:25:21 -070060 struct nsproxy *new_nsp;
Serge E. Hallynab516012006-10-02 02:18:06 -070061
Badari Pulavartye3222c42007-05-08 00:25:21 -070062 new_nsp = clone_nsproxy(tsk->nsproxy);
63 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);
67 if (IS_ERR(new_nsp->mnt_ns))
68 goto out_ns;
69
70 new_nsp->uts_ns = copy_utsname(flags, tsk->nsproxy->uts_ns);
71 if (IS_ERR(new_nsp->uts_ns))
72 goto out_uts;
73
74 new_nsp->ipc_ns = copy_ipcs(flags, tsk->nsproxy->ipc_ns);
75 if (IS_ERR(new_nsp->ipc_ns))
76 goto out_ipc;
77
78 new_nsp->pid_ns = copy_pid_ns(flags, tsk->nsproxy->pid_ns);
79 if (IS_ERR(new_nsp->pid_ns))
80 goto out_pid;
81
82 return new_nsp;
83
84out_pid:
85 if (new_nsp->ipc_ns)
86 put_ipc_ns(new_nsp->ipc_ns);
87out_ipc:
88 if (new_nsp->uts_ns)
89 put_uts_ns(new_nsp->uts_ns);
90out_uts:
91 if (new_nsp->mnt_ns)
92 put_mnt_ns(new_nsp->mnt_ns);
93out_ns:
94 kfree(new_nsp);
95 return ERR_PTR(-ENOMEM);
Serge E. Hallynab516012006-10-02 02:18:06 -070096}
97
98/*
99 * called from clone. This now handles copy for nsproxy and all
100 * namespaces therein.
101 */
102int copy_namespaces(int flags, struct task_struct *tsk)
103{
104 struct nsproxy *old_ns = tsk->nsproxy;
Serge E. Hallyn1651e142006-10-02 02:18:08 -0700105 struct nsproxy *new_ns;
106 int err = 0;
Serge E. Hallynab516012006-10-02 02:18:06 -0700107
108 if (!old_ns)
109 return 0;
110
111 get_nsproxy(old_ns);
112
Kirill Korotaev25b21cb2006-10-02 02:18:19 -0700113 if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC)))
Serge E. Hallyn1651e142006-10-02 02:18:08 -0700114 return 0;
115
Badari Pulavartye3222c42007-05-08 00:25:21 -0700116 if (!capable(CAP_SYS_ADMIN)) {
117 err = -EPERM;
118 goto out;
119 }
120
121 new_ns = create_new_namespaces(flags, tsk, tsk->fs);
122 if (IS_ERR(new_ns)) {
123 err = PTR_ERR(new_ns);
Serge E. Hallyn1651e142006-10-02 02:18:08 -0700124 goto out;
125 }
126
127 tsk->nsproxy = new_ns;
Serge E. Hallyn1651e142006-10-02 02:18:08 -0700128out:
Linus Torvalds444f3782007-01-30 13:35:18 -0800129 put_nsproxy(old_ns);
Serge E. Hallyn1651e142006-10-02 02:18:08 -0700130 return err;
Serge E. Hallynab516012006-10-02 02:18:06 -0700131}
132
133void free_nsproxy(struct nsproxy *ns)
134{
Cedric Le Goater9a575a92006-12-08 02:37:59 -0800135 if (ns->mnt_ns)
136 put_mnt_ns(ns->mnt_ns);
137 if (ns->uts_ns)
138 put_uts_ns(ns->uts_ns);
139 if (ns->ipc_ns)
140 put_ipc_ns(ns->ipc_ns);
141 if (ns->pid_ns)
142 put_pid_ns(ns->pid_ns);
143 kfree(ns);
Serge E. Hallynab516012006-10-02 02:18:06 -0700144}
Badari Pulavartye3222c42007-05-08 00:25:21 -0700145
146/*
147 * Called from unshare. Unshare all the namespaces part of nsproxy.
148 * On sucess, returns the new nsproxy and a reference to old nsproxy
149 * to make sure it stays around.
150 */
151int unshare_nsproxy_namespaces(unsigned long unshare_flags,
152 struct nsproxy **new_nsp, struct fs_struct *new_fs)
153{
154 struct nsproxy *old_ns = current->nsproxy;
155 int err = 0;
156
157 if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC)))
158 return 0;
159
160#ifndef CONFIG_IPC_NS
161 if (unshare_flags & CLONE_NEWIPC)
162 return -EINVAL;
163#endif
164
165#ifndef CONFIG_UTS_NS
166 if (unshare_flags & CLONE_NEWUTS)
167 return -EINVAL;
168#endif
169
170 if (!capable(CAP_SYS_ADMIN))
171 return -EPERM;
172
173 get_nsproxy(old_ns);
174
175 *new_nsp = create_new_namespaces(unshare_flags, current,
176 new_fs ? new_fs : current->fs);
177 if (IS_ERR(*new_nsp)) {
178 err = PTR_ERR(*new_nsp);
179 put_nsproxy(old_ns);
180 }
181 return err;
182}