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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#include <linux/perf_event.h>
30
31static struct kmem_cache *nsproxy_cachep;
32
33struct nsproxy init_nsproxy = {
34 .count = ATOMIC_INIT(1),
35 .uts_ns = &init_uts_ns,
36#if defined(CONFIG_POSIX_MQUEUE) || defined(CONFIG_SYSVIPC)
37 .ipc_ns = &init_ipc_ns,
38#endif
39 .mnt_ns = NULL,
40 .pid_ns_for_children = &init_pid_ns,
41#ifdef CONFIG_NET
42 .net_ns = &init_net,
43#endif
44#ifdef CONFIG_CGROUPS
45 .cgroup_ns = &init_cgroup_ns,
46#endif
47};
48
49static inline struct nsproxy *create_nsproxy(void)
50{
51 struct nsproxy *nsproxy;
52
53 nsproxy = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL);
54 if (nsproxy)
55 atomic_set(&nsproxy->count, 1);
56 return nsproxy;
57}
58
59/*
60 * Create new nsproxy and all of its the associated namespaces.
61 * Return the newly created nsproxy. Do not attach this to the task,
62 * leave it to the caller to do proper locking and attach it to task.
63 */
64static struct nsproxy *create_new_namespaces(unsigned long flags,
65 struct task_struct *tsk, struct user_namespace *user_ns,
66 struct fs_struct *new_fs)
67{
68 struct nsproxy *new_nsp;
69 int err;
70
71 new_nsp = create_nsproxy();
72 if (!new_nsp)
73 return ERR_PTR(-ENOMEM);
74
75 new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, user_ns, new_fs);
76 if (IS_ERR(new_nsp->mnt_ns)) {
77 err = PTR_ERR(new_nsp->mnt_ns);
78 goto out_ns;
79 }
80
81 new_nsp->uts_ns = copy_utsname(flags, user_ns, tsk->nsproxy->uts_ns);
82 if (IS_ERR(new_nsp->uts_ns)) {
83 err = PTR_ERR(new_nsp->uts_ns);
84 goto out_uts;
85 }
86
87 new_nsp->ipc_ns = copy_ipcs(flags, user_ns, tsk->nsproxy->ipc_ns);
88 if (IS_ERR(new_nsp->ipc_ns)) {
89 err = PTR_ERR(new_nsp->ipc_ns);
90 goto out_ipc;
91 }
92
93 new_nsp->pid_ns_for_children =
94 copy_pid_ns(flags, user_ns, tsk->nsproxy->pid_ns_for_children);
95 if (IS_ERR(new_nsp->pid_ns_for_children)) {
96 err = PTR_ERR(new_nsp->pid_ns_for_children);
97 goto out_pid;
98 }
99
100 new_nsp->cgroup_ns = copy_cgroup_ns(flags, user_ns,
101 tsk->nsproxy->cgroup_ns);
102 if (IS_ERR(new_nsp->cgroup_ns)) {
103 err = PTR_ERR(new_nsp->cgroup_ns);
104 goto out_cgroup;
105 }
106
107 new_nsp->net_ns = copy_net_ns(flags, user_ns, tsk->nsproxy->net_ns);
108 if (IS_ERR(new_nsp->net_ns)) {
109 err = PTR_ERR(new_nsp->net_ns);
110 goto out_net;
111 }
112
113 return new_nsp;
114
115out_net:
116 put_cgroup_ns(new_nsp->cgroup_ns);
117out_cgroup:
118 if (new_nsp->pid_ns_for_children)
119 put_pid_ns(new_nsp->pid_ns_for_children);
120out_pid:
121 if (new_nsp->ipc_ns)
122 put_ipc_ns(new_nsp->ipc_ns);
123out_ipc:
124 if (new_nsp->uts_ns)
125 put_uts_ns(new_nsp->uts_ns);
126out_uts:
127 if (new_nsp->mnt_ns)
128 put_mnt_ns(new_nsp->mnt_ns);
129out_ns:
130 kmem_cache_free(nsproxy_cachep, new_nsp);
131 return ERR_PTR(err);
132}
133
134/*
135 * called from clone. This now handles copy for nsproxy and all
136 * namespaces therein.
137 */
138int copy_namespaces(unsigned long flags, struct task_struct *tsk)
139{
140 struct nsproxy *old_ns = tsk->nsproxy;
141 struct user_namespace *user_ns = task_cred_xxx(tsk, user_ns);
142 struct nsproxy *new_ns;
143
144 if (likely(!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
145 CLONE_NEWPID | CLONE_NEWNET |
146 CLONE_NEWCGROUP)))) {
147 get_nsproxy(old_ns);
148 return 0;
149 }
150
151 if (!ns_capable(user_ns, CAP_SYS_ADMIN))
152 return -EPERM;
153
154 /*
155 * CLONE_NEWIPC must detach from the undolist: after switching
156 * to a new ipc namespace, the semaphore arrays from the old
157 * namespace are unreachable. In clone parlance, CLONE_SYSVSEM
158 * means share undolist with parent, so we must forbid using
159 * it along with CLONE_NEWIPC.
160 */
161 if ((flags & (CLONE_NEWIPC | CLONE_SYSVSEM)) ==
162 (CLONE_NEWIPC | CLONE_SYSVSEM))
163 return -EINVAL;
164
165 new_ns = create_new_namespaces(flags, tsk, user_ns, tsk->fs);
166 if (IS_ERR(new_ns))
167 return PTR_ERR(new_ns);
168
169 tsk->nsproxy = new_ns;
170 return 0;
171}
172
173void free_nsproxy(struct nsproxy *ns)
174{
175 if (ns->mnt_ns)
176 put_mnt_ns(ns->mnt_ns);
177 if (ns->uts_ns)
178 put_uts_ns(ns->uts_ns);
179 if (ns->ipc_ns)
180 put_ipc_ns(ns->ipc_ns);
181 if (ns->pid_ns_for_children)
182 put_pid_ns(ns->pid_ns_for_children);
183 put_cgroup_ns(ns->cgroup_ns);
184 put_net(ns->net_ns);
185 kmem_cache_free(nsproxy_cachep, ns);
186}
187
188/*
189 * Called from unshare. Unshare all the namespaces part of nsproxy.
190 * On success, returns the new nsproxy.
191 */
192int unshare_nsproxy_namespaces(unsigned long unshare_flags,
193 struct nsproxy **new_nsp, struct cred *new_cred, struct fs_struct *new_fs)
194{
195 struct user_namespace *user_ns;
196 int err = 0;
197
198 if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
199 CLONE_NEWNET | CLONE_NEWPID | CLONE_NEWCGROUP)))
200 return 0;
201
202 user_ns = new_cred ? new_cred->user_ns : current_user_ns();
203 if (!ns_capable(user_ns, CAP_SYS_ADMIN))
204 return -EPERM;
205
206 *new_nsp = create_new_namespaces(unshare_flags, current, user_ns,
207 new_fs ? new_fs : current->fs);
208 if (IS_ERR(*new_nsp)) {
209 err = PTR_ERR(*new_nsp);
210 goto out;
211 }
212
213out:
214 return err;
215}
216
217void switch_task_namespaces(struct task_struct *p, struct nsproxy *new)
218{
219 struct nsproxy *ns;
220
221 might_sleep();
222
223 task_lock(p);
224 ns = p->nsproxy;
225 p->nsproxy = new;
226 task_unlock(p);
227
228 if (ns && atomic_dec_and_test(&ns->count))
229 free_nsproxy(ns);
230}
231
232void exit_task_namespaces(struct task_struct *p)
233{
234 switch_task_namespaces(p, NULL);
235}
236
237SYSCALL_DEFINE2(setns, int, fd, int, nstype)
238{
239 struct task_struct *tsk = current;
240 struct nsproxy *new_nsproxy;
241 struct file *file;
242 struct ns_common *ns;
243 int err;
244
245 file = proc_ns_fget(fd);
246 if (IS_ERR(file))
247 return PTR_ERR(file);
248
249 err = -EINVAL;
250 ns = get_proc_ns(file_inode(file));
251 if (nstype && (ns->ops->type != nstype))
252 goto out;
253
254 new_nsproxy = create_new_namespaces(0, tsk, current_user_ns(), tsk->fs);
255 if (IS_ERR(new_nsproxy)) {
256 err = PTR_ERR(new_nsproxy);
257 goto out;
258 }
259
260 err = ns->ops->install(new_nsproxy, ns);
261 if (err) {
262 free_nsproxy(new_nsproxy);
263 goto out;
264 }
265 switch_task_namespaces(tsk, new_nsproxy);
266
267 perf_event_namespaces(tsk);
268out:
269 fput(file);
270 return err;
271}
272
273int __init nsproxy_cache_init(void)
274{
275 nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);
276 return 0;
277}