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1/*
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.
10 *
11 * Jun 2006 - namespaces support
12 * OpenVZ, SWsoft Inc.
13 * Pavel Emelianov <xemul@openvz.org>
14 */
15
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>
29
30static struct kmem_cache *nsproxy_cachep;
31
32struct 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,
37#endif
38 .mnt_ns = NULL,
39 .pid_ns_for_children = &init_pid_ns,
40#ifdef CONFIG_NET
41 .net_ns = &init_net,
42#endif
43#ifdef CONFIG_CGROUPS
44 .cgroup_ns = &init_cgroup_ns,
45#endif
46};
47
48static inline struct nsproxy *create_nsproxy(void)
49{
50 struct nsproxy *nsproxy;
51
52 nsproxy = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL);
53 if (nsproxy)
54 atomic_set(&nsproxy->count, 1);
55 return nsproxy;
56}
57
58/*
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.
62 */
63static struct nsproxy *create_new_namespaces(unsigned long flags,
64 struct task_struct *tsk, struct user_namespace *user_ns,
65 struct fs_struct *new_fs)
66{
67 struct nsproxy *new_nsp;
68 int err;
69
70 new_nsp = create_nsproxy();
71 if (!new_nsp)
72 return ERR_PTR(-ENOMEM);
73
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);
77 goto out_ns;
78 }
79
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);
83 goto out_uts;
84 }
85
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);
89 goto out_ipc;
90 }
91
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);
96 goto out_pid;
97 }
98
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);
103 goto out_cgroup;
104 }
105
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);
109 goto out_net;
110 }
111
112 return new_nsp;
113
114out_net:
115 put_cgroup_ns(new_nsp->cgroup_ns);
116out_cgroup:
117 if (new_nsp->pid_ns_for_children)
118 put_pid_ns(new_nsp->pid_ns_for_children);
119out_pid:
120 if (new_nsp->ipc_ns)
121 put_ipc_ns(new_nsp->ipc_ns);
122out_ipc:
123 if (new_nsp->uts_ns)
124 put_uts_ns(new_nsp->uts_ns);
125out_uts:
126 if (new_nsp->mnt_ns)
127 put_mnt_ns(new_nsp->mnt_ns);
128out_ns:
129 kmem_cache_free(nsproxy_cachep, new_nsp);
130 return ERR_PTR(err);
131}
132
133/*
134 * called from clone. This now handles copy for nsproxy and all
135 * namespaces therein.
136 */
137int copy_namespaces(unsigned long flags, struct task_struct *tsk)
138{
139 struct nsproxy *old_ns = tsk->nsproxy;
140 struct user_namespace *user_ns = task_cred_xxx(tsk, user_ns);
141 struct nsproxy *new_ns;
142
143 if (likely(!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
144 CLONE_NEWPID | CLONE_NEWNET |
145 CLONE_NEWCGROUP)))) {
146 get_nsproxy(old_ns);
147 return 0;
148 }
149
150 if (!ns_capable(user_ns, CAP_SYS_ADMIN))
151 return -EPERM;
152
153 /*
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.
159 */
160 if ((flags & (CLONE_NEWIPC | CLONE_SYSVSEM)) ==
161 (CLONE_NEWIPC | CLONE_SYSVSEM))
162 return -EINVAL;
163
164 new_ns = create_new_namespaces(flags, tsk, user_ns, tsk->fs);
165 if (IS_ERR(new_ns))
166 return PTR_ERR(new_ns);
167
168 tsk->nsproxy = new_ns;
169 return 0;
170}
171
172void free_nsproxy(struct nsproxy *ns)
173{
174 if (ns->mnt_ns)
175 put_mnt_ns(ns->mnt_ns);
176 if (ns->uts_ns)
177 put_uts_ns(ns->uts_ns);
178 if (ns->ipc_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);
183 put_net(ns->net_ns);
184 kmem_cache_free(nsproxy_cachep, ns);
185}
186
187/*
188 * Called from unshare. Unshare all the namespaces part of nsproxy.
189 * On success, returns the new nsproxy.
190 */
191int unshare_nsproxy_namespaces(unsigned long unshare_flags,
192 struct nsproxy **new_nsp, struct cred *new_cred, struct fs_struct *new_fs)
193{
194 struct user_namespace *user_ns;
195 int err = 0;
196
197 if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
198 CLONE_NEWNET | CLONE_NEWPID | CLONE_NEWCGROUP)))
199 return 0;
200
201 user_ns = new_cred ? new_cred->user_ns : current_user_ns();
202 if (!ns_capable(user_ns, CAP_SYS_ADMIN))
203 return -EPERM;
204
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);
209 goto out;
210 }
211
212out:
213 return err;
214}
215
216void switch_task_namespaces(struct task_struct *p, struct nsproxy *new)
217{
218 struct nsproxy *ns;
219
220 might_sleep();
221
222 task_lock(p);
223 ns = p->nsproxy;
224 p->nsproxy = new;
225 task_unlock(p);
226
227 if (ns && atomic_dec_and_test(&ns->count))
228 free_nsproxy(ns);
229}
230
231void exit_task_namespaces(struct task_struct *p)
232{
233 switch_task_namespaces(p, NULL);
234}
235
236SYSCALL_DEFINE2(setns, int, fd, int, nstype)
237{
238 struct task_struct *tsk = current;
239 struct nsproxy *new_nsproxy;
240 struct file *file;
241 struct ns_common *ns;
242 int err;
243
244 file = proc_ns_fget(fd);
245 if (IS_ERR(file))
246 return PTR_ERR(file);
247
248 err = -EINVAL;
249 ns = get_proc_ns(file_inode(file));
250 if (nstype && (ns->ops->type != nstype))
251 goto out;
252
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);
256 goto out;
257 }
258
259 err = ns->ops->install(new_nsproxy, ns);
260 if (err) {
261 free_nsproxy(new_nsproxy);
262 goto out;
263 }
264 switch_task_namespaces(tsk, new_nsproxy);
265out:
266 fput(file);
267 return err;
268}
269
270int __init nsproxy_cache_init(void)
271{
272 nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);
273 return 0;
274}
1/*
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.
10 *
11 * Jun 2006 - namespaces support
12 * OpenVZ, SWsoft Inc.
13 * Pavel Emelianov <xemul@openvz.org>
14 */
15
16#include <linux/slab.h>
17#include <linux/module.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_fs.h>
26#include <linux/file.h>
27#include <linux/syscalls.h>
28
29static struct kmem_cache *nsproxy_cachep;
30
31struct 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};
43
44static inline struct nsproxy *create_nsproxy(void)
45{
46 struct nsproxy *nsproxy;
47
48 nsproxy = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL);
49 if (nsproxy)
50 atomic_set(&nsproxy->count, 1);
51 return nsproxy;
52}
53
54/*
55 * 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.
58 */
59static struct nsproxy *create_new_namespaces(unsigned long flags,
60 struct task_struct *tsk, struct fs_struct *new_fs)
61{
62 struct nsproxy *new_nsp;
63 int err;
64
65 new_nsp = create_nsproxy();
66 if (!new_nsp)
67 return ERR_PTR(-ENOMEM);
68
69 new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, new_fs);
70 if (IS_ERR(new_nsp->mnt_ns)) {
71 err = PTR_ERR(new_nsp->mnt_ns);
72 goto out_ns;
73 }
74
75 new_nsp->uts_ns = copy_utsname(flags, tsk);
76 if (IS_ERR(new_nsp->uts_ns)) {
77 err = PTR_ERR(new_nsp->uts_ns);
78 goto out_uts;
79 }
80
81 new_nsp->ipc_ns = copy_ipcs(flags, tsk);
82 if (IS_ERR(new_nsp->ipc_ns)) {
83 err = PTR_ERR(new_nsp->ipc_ns);
84 goto out_ipc;
85 }
86
87 new_nsp->pid_ns = copy_pid_ns(flags, task_active_pid_ns(tsk));
88 if (IS_ERR(new_nsp->pid_ns)) {
89 err = PTR_ERR(new_nsp->pid_ns);
90 goto out_pid;
91 }
92
93 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
99 return new_nsp;
100
101out_net:
102 if (new_nsp->pid_ns)
103 put_pid_ns(new_nsp->pid_ns);
104out_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:
114 kmem_cache_free(nsproxy_cachep, new_nsp);
115 return ERR_PTR(err);
116}
117
118/*
119 * called from clone. This now handles copy for nsproxy and all
120 * namespaces therein.
121 */
122int copy_namespaces(unsigned long flags, struct task_struct *tsk)
123{
124 struct nsproxy *old_ns = tsk->nsproxy;
125 struct nsproxy *new_ns;
126 int err = 0;
127
128 if (!old_ns)
129 return 0;
130
131 get_nsproxy(old_ns);
132
133 if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
134 CLONE_NEWPID | CLONE_NEWNET)))
135 return 0;
136
137 if (!capable(CAP_SYS_ADMIN)) {
138 err = -EPERM;
139 goto out;
140 }
141
142 /*
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
154 new_ns = create_new_namespaces(flags, tsk, tsk->fs);
155 if (IS_ERR(new_ns)) {
156 err = PTR_ERR(new_ns);
157 goto out;
158 }
159
160 tsk->nsproxy = new_ns;
161
162out:
163 put_nsproxy(old_ns);
164 return err;
165}
166
167void free_nsproxy(struct nsproxy *ns)
168{
169 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);
177 put_net(ns->net_ns);
178 kmem_cache_free(nsproxy_cachep, ns);
179}
180
181/*
182 * Called from unshare. Unshare all the namespaces part of nsproxy.
183 * On success, returns the new nsproxy.
184 */
185int unshare_nsproxy_namespaces(unsigned long unshare_flags,
186 struct nsproxy **new_nsp, struct fs_struct *new_fs)
187{
188 int err = 0;
189
190 if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
191 CLONE_NEWNET)))
192 return 0;
193
194 if (!capable(CAP_SYS_ADMIN))
195 return -EPERM;
196
197 *new_nsp = create_new_namespaces(unshare_flags, current,
198 new_fs ? new_fs : current->fs);
199 if (IS_ERR(*new_nsp)) {
200 err = PTR_ERR(*new_nsp);
201 goto out;
202 }
203
204out:
205 return err;
206}
207
208void 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
235SYSCALL_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
274int __init nsproxy_cache_init(void)
275{
276 nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);
277 return 0;
278}