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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
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_for_children = &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 user_namespace *user_ns,
61 struct fs_struct *new_fs)
62{
63 struct nsproxy *new_nsp;
64 int err;
65
66 new_nsp = create_nsproxy();
67 if (!new_nsp)
68 return ERR_PTR(-ENOMEM);
69
70 new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, user_ns, new_fs);
71 if (IS_ERR(new_nsp->mnt_ns)) {
72 err = PTR_ERR(new_nsp->mnt_ns);
73 goto out_ns;
74 }
75
76 new_nsp->uts_ns = copy_utsname(flags, user_ns, tsk->nsproxy->uts_ns);
77 if (IS_ERR(new_nsp->uts_ns)) {
78 err = PTR_ERR(new_nsp->uts_ns);
79 goto out_uts;
80 }
81
82 new_nsp->ipc_ns = copy_ipcs(flags, user_ns, tsk->nsproxy->ipc_ns);
83 if (IS_ERR(new_nsp->ipc_ns)) {
84 err = PTR_ERR(new_nsp->ipc_ns);
85 goto out_ipc;
86 }
87
88 new_nsp->pid_ns_for_children =
89 copy_pid_ns(flags, user_ns, tsk->nsproxy->pid_ns_for_children);
90 if (IS_ERR(new_nsp->pid_ns_for_children)) {
91 err = PTR_ERR(new_nsp->pid_ns_for_children);
92 goto out_pid;
93 }
94
95 new_nsp->net_ns = copy_net_ns(flags, user_ns, tsk->nsproxy->net_ns);
96 if (IS_ERR(new_nsp->net_ns)) {
97 err = PTR_ERR(new_nsp->net_ns);
98 goto out_net;
99 }
100
101 return new_nsp;
102
103out_net:
104 if (new_nsp->pid_ns_for_children)
105 put_pid_ns(new_nsp->pid_ns_for_children);
106out_pid:
107 if (new_nsp->ipc_ns)
108 put_ipc_ns(new_nsp->ipc_ns);
109out_ipc:
110 if (new_nsp->uts_ns)
111 put_uts_ns(new_nsp->uts_ns);
112out_uts:
113 if (new_nsp->mnt_ns)
114 put_mnt_ns(new_nsp->mnt_ns);
115out_ns:
116 kmem_cache_free(nsproxy_cachep, new_nsp);
117 return ERR_PTR(err);
118}
119
120/*
121 * called from clone. This now handles copy for nsproxy and all
122 * namespaces therein.
123 */
124int copy_namespaces(unsigned long flags, struct task_struct *tsk)
125{
126 struct nsproxy *old_ns = tsk->nsproxy;
127 struct user_namespace *user_ns = task_cred_xxx(tsk, user_ns);
128 struct nsproxy *new_ns;
129
130 if (likely(!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
131 CLONE_NEWPID | CLONE_NEWNET)))) {
132 get_nsproxy(old_ns);
133 return 0;
134 }
135
136 if (!ns_capable(user_ns, CAP_SYS_ADMIN))
137 return -EPERM;
138
139 /*
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 | CLONE_SYSVSEM)) ==
147 (CLONE_NEWIPC | CLONE_SYSVSEM))
148 return -EINVAL;
149
150 new_ns = create_new_namespaces(flags, tsk, user_ns, tsk->fs);
151 if (IS_ERR(new_ns))
152 return PTR_ERR(new_ns);
153
154 tsk->nsproxy = new_ns;
155 return 0;
156}
157
158void free_nsproxy(struct nsproxy *ns)
159{
160 if (ns->mnt_ns)
161 put_mnt_ns(ns->mnt_ns);
162 if (ns->uts_ns)
163 put_uts_ns(ns->uts_ns);
164 if (ns->ipc_ns)
165 put_ipc_ns(ns->ipc_ns);
166 if (ns->pid_ns_for_children)
167 put_pid_ns(ns->pid_ns_for_children);
168 put_net(ns->net_ns);
169 kmem_cache_free(nsproxy_cachep, ns);
170}
171
172/*
173 * Called from unshare. Unshare all the namespaces part of nsproxy.
174 * On success, returns the new nsproxy.
175 */
176int unshare_nsproxy_namespaces(unsigned long unshare_flags,
177 struct nsproxy **new_nsp, struct cred *new_cred, struct fs_struct *new_fs)
178{
179 struct user_namespace *user_ns;
180 int err = 0;
181
182 if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
183 CLONE_NEWNET | CLONE_NEWPID)))
184 return 0;
185
186 user_ns = new_cred ? new_cred->user_ns : current_user_ns();
187 if (!ns_capable(user_ns, CAP_SYS_ADMIN))
188 return -EPERM;
189
190 *new_nsp = create_new_namespaces(unshare_flags, current, user_ns,
191 new_fs ? new_fs : current->fs);
192 if (IS_ERR(*new_nsp)) {
193 err = PTR_ERR(*new_nsp);
194 goto out;
195 }
196
197out:
198 return err;
199}
200
201void switch_task_namespaces(struct task_struct *p, struct nsproxy *new)
202{
203 struct nsproxy *ns;
204
205 might_sleep();
206
207 ns = p->nsproxy;
208
209 rcu_assign_pointer(p->nsproxy, new);
210
211 if (ns && atomic_dec_and_test(&ns->count)) {
212 /*
213 * wait for others to get what they want from this nsproxy.
214 *
215 * cannot release this nsproxy via the call_rcu() since
216 * put_mnt_ns() will want to sleep
217 */
218 synchronize_rcu();
219 free_nsproxy(ns);
220 }
221}
222
223void exit_task_namespaces(struct task_struct *p)
224{
225 switch_task_namespaces(p, NULL);
226}
227
228SYSCALL_DEFINE2(setns, int, fd, int, nstype)
229{
230 const struct proc_ns_operations *ops;
231 struct task_struct *tsk = current;
232 struct nsproxy *new_nsproxy;
233 struct proc_ns *ei;
234 struct file *file;
235 int err;
236
237 file = proc_ns_fget(fd);
238 if (IS_ERR(file))
239 return PTR_ERR(file);
240
241 err = -EINVAL;
242 ei = get_proc_ns(file_inode(file));
243 ops = ei->ns_ops;
244 if (nstype && (ops->type != nstype))
245 goto out;
246
247 new_nsproxy = create_new_namespaces(0, tsk, current_user_ns(), tsk->fs);
248 if (IS_ERR(new_nsproxy)) {
249 err = PTR_ERR(new_nsproxy);
250 goto out;
251 }
252
253 err = ops->install(new_nsproxy, ei->ns);
254 if (err) {
255 free_nsproxy(new_nsproxy);
256 goto out;
257 }
258 switch_task_namespaces(tsk, new_nsproxy);
259out:
260 fput(file);
261 return err;
262}
263
264int __init nsproxy_cache_init(void)
265{
266 nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);
267 return 0;
268}
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}