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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
56
57
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
122
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 int err = 0;
130
131 if (!old_ns)
132 return 0;
133
134 get_nsproxy(old_ns);
135
136 if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
137 CLONE_NEWPID | CLONE_NEWNET)))
138 return 0;
139
140 if (!ns_capable(user_ns, CAP_SYS_ADMIN)) {
141 err = -EPERM;
142 goto out;
143 }
144
145
146
147
148
149
150
151
152 if ((flags & CLONE_NEWIPC) && (flags & CLONE_SYSVSEM)) {
153 err = -EINVAL;
154 goto out;
155 }
156
157 new_ns = create_new_namespaces(flags, tsk, user_ns, tsk->fs);
158 if (IS_ERR(new_ns)) {
159 err = PTR_ERR(new_ns);
160 goto out;
161 }
162
163 tsk->nsproxy = new_ns;
164
165out:
166 put_nsproxy(old_ns);
167 return err;
168}
169
170void free_nsproxy(struct nsproxy *ns)
171{
172 if (ns->mnt_ns)
173 put_mnt_ns(ns->mnt_ns);
174 if (ns->uts_ns)
175 put_uts_ns(ns->uts_ns);
176 if (ns->ipc_ns)
177 put_ipc_ns(ns->ipc_ns);
178 if (ns->pid_ns_for_children)
179 put_pid_ns(ns->pid_ns_for_children);
180 put_net(ns->net_ns);
181 kmem_cache_free(nsproxy_cachep, ns);
182}
183
184
185
186
187
188int unshare_nsproxy_namespaces(unsigned long unshare_flags,
189 struct nsproxy **new_nsp, struct cred *new_cred, struct fs_struct *new_fs)
190{
191 struct user_namespace *user_ns;
192 int err = 0;
193
194 if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
195 CLONE_NEWNET | CLONE_NEWPID)))
196 return 0;
197
198 user_ns = new_cred ? new_cred->user_ns : current_user_ns();
199 if (!ns_capable(user_ns, CAP_SYS_ADMIN))
200 return -EPERM;
201
202 *new_nsp = create_new_namespaces(unshare_flags, current, user_ns,
203 new_fs ? new_fs : current->fs);
204 if (IS_ERR(*new_nsp)) {
205 err = PTR_ERR(*new_nsp);
206 goto out;
207 }
208
209out:
210 return err;
211}
212
213void switch_task_namespaces(struct task_struct *p, struct nsproxy *new)
214{
215 struct nsproxy *ns;
216
217 might_sleep();
218
219 ns = p->nsproxy;
220
221 rcu_assign_pointer(p->nsproxy, new);
222
223 if (ns && atomic_dec_and_test(&ns->count)) {
224
225
226
227
228
229
230 synchronize_rcu();
231 free_nsproxy(ns);
232 }
233}
234
235void exit_task_namespaces(struct task_struct *p)
236{
237 switch_task_namespaces(p, NULL);
238}
239
240SYSCALL_DEFINE2(setns, int, fd, int, nstype)
241{
242 const struct proc_ns_operations *ops;
243 struct task_struct *tsk = current;
244 struct nsproxy *new_nsproxy;
245 struct proc_ns *ei;
246 struct file *file;
247 int err;
248
249 file = proc_ns_fget(fd);
250 if (IS_ERR(file))
251 return PTR_ERR(file);
252
253 err = -EINVAL;
254 ei = get_proc_ns(file_inode(file));
255 ops = ei->ns_ops;
256 if (nstype && (ops->type != nstype))
257 goto out;
258
259 new_nsproxy = create_new_namespaces(0, tsk, current_user_ns(), tsk->fs);
260 if (IS_ERR(new_nsproxy)) {
261 err = PTR_ERR(new_nsproxy);
262 goto out;
263 }
264
265 err = ops->install(new_nsproxy, ei->ns);
266 if (err) {
267 free_nsproxy(new_nsproxy);
268 goto out;
269 }
270 switch_task_namespaces(tsk, new_nsproxy);
271out:
272 fput(file);
273 return err;
274}
275
276int __init nsproxy_cache_init(void)
277{
278 nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);
279 return 0;
280}
281