Commit | Line | Data |
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ab516013 SH |
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 | ||
12 | #include <linux/module.h> | |
13 | #include <linux/version.h> | |
14 | #include <linux/nsproxy.h> | |
0437eb59 | 15 | #include <linux/init_task.h> |
1651e14e | 16 | #include <linux/namespace.h> |
4865ecf1 | 17 | #include <linux/utsname.h> |
0437eb59 SH |
18 | |
19 | struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy); | |
ab516013 SH |
20 | |
21 | static inline void get_nsproxy(struct nsproxy *ns) | |
22 | { | |
23 | atomic_inc(&ns->count); | |
24 | } | |
25 | ||
26 | void get_task_namespaces(struct task_struct *tsk) | |
27 | { | |
28 | struct nsproxy *ns = tsk->nsproxy; | |
29 | if (ns) { | |
30 | get_nsproxy(ns); | |
31 | } | |
32 | } | |
33 | ||
34 | /* | |
35 | * creates a copy of "orig" with refcount 1. | |
36 | * This does not grab references to the contained namespaces, | |
37 | * so that needs to be done by dup_namespaces. | |
38 | */ | |
39 | static inline struct nsproxy *clone_namespaces(struct nsproxy *orig) | |
40 | { | |
41 | struct nsproxy *ns; | |
42 | ||
43 | ns = kmalloc(sizeof(struct nsproxy), GFP_KERNEL); | |
44 | if (ns) { | |
45 | memcpy(ns, orig, sizeof(struct nsproxy)); | |
46 | atomic_set(&ns->count, 1); | |
47 | } | |
48 | return ns; | |
49 | } | |
50 | ||
51 | /* | |
52 | * copies the nsproxy, setting refcount to 1, and grabbing a | |
53 | * reference to all contained namespaces. Called from | |
54 | * sys_unshare() | |
55 | */ | |
56 | struct nsproxy *dup_namespaces(struct nsproxy *orig) | |
57 | { | |
58 | struct nsproxy *ns = clone_namespaces(orig); | |
59 | ||
1651e14e SH |
60 | if (ns) { |
61 | if (ns->namespace) | |
62 | get_namespace(ns->namespace); | |
4865ecf1 SH |
63 | if (ns->uts_ns) |
64 | get_uts_ns(ns->uts_ns); | |
1651e14e SH |
65 | } |
66 | ||
ab516013 SH |
67 | return ns; |
68 | } | |
69 | ||
70 | /* | |
71 | * called from clone. This now handles copy for nsproxy and all | |
72 | * namespaces therein. | |
73 | */ | |
74 | int copy_namespaces(int flags, struct task_struct *tsk) | |
75 | { | |
76 | struct nsproxy *old_ns = tsk->nsproxy; | |
1651e14e SH |
77 | struct nsproxy *new_ns; |
78 | int err = 0; | |
ab516013 SH |
79 | |
80 | if (!old_ns) | |
81 | return 0; | |
82 | ||
83 | get_nsproxy(old_ns); | |
84 | ||
071df104 | 85 | if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS))) |
1651e14e SH |
86 | return 0; |
87 | ||
88 | new_ns = clone_namespaces(old_ns); | |
89 | if (!new_ns) { | |
90 | err = -ENOMEM; | |
91 | goto out; | |
92 | } | |
93 | ||
94 | tsk->nsproxy = new_ns; | |
95 | ||
96 | err = copy_namespace(flags, tsk); | |
97 | if (err) { | |
98 | tsk->nsproxy = old_ns; | |
99 | put_nsproxy(new_ns); | |
100 | goto out; | |
101 | } | |
102 | ||
4865ecf1 SH |
103 | err = copy_utsname(flags, tsk); |
104 | if (err) { | |
105 | if (new_ns->namespace) | |
106 | put_namespace(new_ns->namespace); | |
107 | tsk->nsproxy = old_ns; | |
108 | put_nsproxy(new_ns); | |
109 | goto out; | |
110 | } | |
111 | ||
1651e14e SH |
112 | out: |
113 | put_nsproxy(old_ns); | |
114 | return err; | |
ab516013 SH |
115 | } |
116 | ||
117 | void free_nsproxy(struct nsproxy *ns) | |
118 | { | |
1651e14e SH |
119 | if (ns->namespace) |
120 | put_namespace(ns->namespace); | |
4865ecf1 SH |
121 | if (ns->uts_ns) |
122 | put_uts_ns(ns->uts_ns); | |
ab516013 SH |
123 | kfree(ns); |
124 | } |