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. | |
25b21cb2 KK |
10 | * |
11 | * Jun 2006 - namespaces support | |
12 | * OpenVZ, SWsoft Inc. | |
13 | * Pavel Emelianov <xemul@openvz.org> | |
ab516013 SH |
14 | */ |
15 | ||
16 | #include <linux/module.h> | |
17 | #include <linux/version.h> | |
18 | #include <linux/nsproxy.h> | |
0437eb59 | 19 | #include <linux/init_task.h> |
6b3286ed | 20 | #include <linux/mnt_namespace.h> |
4865ecf1 | 21 | #include <linux/utsname.h> |
0437eb59 SH |
22 | |
23 | struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy); | |
ab516013 SH |
24 | |
25 | static inline void get_nsproxy(struct nsproxy *ns) | |
26 | { | |
27 | atomic_inc(&ns->count); | |
28 | } | |
29 | ||
30 | void get_task_namespaces(struct task_struct *tsk) | |
31 | { | |
32 | struct nsproxy *ns = tsk->nsproxy; | |
33 | if (ns) { | |
34 | get_nsproxy(ns); | |
35 | } | |
36 | } | |
37 | ||
38 | /* | |
39 | * creates a copy of "orig" with refcount 1. | |
40 | * This does not grab references to the contained namespaces, | |
41 | * so that needs to be done by dup_namespaces. | |
42 | */ | |
43 | static inline struct nsproxy *clone_namespaces(struct nsproxy *orig) | |
44 | { | |
45 | struct nsproxy *ns; | |
46 | ||
e05d722e | 47 | ns = kmemdup(orig, sizeof(struct nsproxy), GFP_KERNEL); |
373beb35 | 48 | if (ns) { |
ab516013 | 49 | atomic_set(&ns->count, 1); |
373beb35 CLG |
50 | ns->id = -1; |
51 | } | |
ab516013 SH |
52 | return ns; |
53 | } | |
54 | ||
55 | /* | |
56 | * copies the nsproxy, setting refcount to 1, and grabbing a | |
57 | * reference to all contained namespaces. Called from | |
58 | * sys_unshare() | |
59 | */ | |
60 | struct nsproxy *dup_namespaces(struct nsproxy *orig) | |
61 | { | |
62 | struct nsproxy *ns = clone_namespaces(orig); | |
63 | ||
1651e14e | 64 | if (ns) { |
6b3286ed KK |
65 | if (ns->mnt_ns) |
66 | get_mnt_ns(ns->mnt_ns); | |
4865ecf1 SH |
67 | if (ns->uts_ns) |
68 | get_uts_ns(ns->uts_ns); | |
25b21cb2 KK |
69 | if (ns->ipc_ns) |
70 | get_ipc_ns(ns->ipc_ns); | |
1651e14e SH |
71 | } |
72 | ||
ab516013 SH |
73 | return ns; |
74 | } | |
75 | ||
76 | /* | |
77 | * called from clone. This now handles copy for nsproxy and all | |
78 | * namespaces therein. | |
79 | */ | |
80 | int copy_namespaces(int flags, struct task_struct *tsk) | |
81 | { | |
82 | struct nsproxy *old_ns = tsk->nsproxy; | |
1651e14e SH |
83 | struct nsproxy *new_ns; |
84 | int err = 0; | |
ab516013 SH |
85 | |
86 | if (!old_ns) | |
87 | return 0; | |
88 | ||
89 | get_nsproxy(old_ns); | |
90 | ||
25b21cb2 | 91 | if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC))) |
1651e14e SH |
92 | return 0; |
93 | ||
94 | new_ns = clone_namespaces(old_ns); | |
95 | if (!new_ns) { | |
96 | err = -ENOMEM; | |
97 | goto out; | |
98 | } | |
99 | ||
100 | tsk->nsproxy = new_ns; | |
101 | ||
6b3286ed | 102 | err = copy_mnt_ns(flags, tsk); |
25b21cb2 KK |
103 | if (err) |
104 | goto out_ns; | |
1651e14e | 105 | |
4865ecf1 | 106 | err = copy_utsname(flags, tsk); |
25b21cb2 KK |
107 | if (err) |
108 | goto out_uts; | |
109 | ||
110 | err = copy_ipcs(flags, tsk); | |
111 | if (err) | |
112 | goto out_ipc; | |
4865ecf1 | 113 | |
1651e14e SH |
114 | out: |
115 | put_nsproxy(old_ns); | |
116 | return err; | |
25b21cb2 KK |
117 | |
118 | out_ipc: | |
119 | if (new_ns->uts_ns) | |
120 | put_uts_ns(new_ns->uts_ns); | |
121 | out_uts: | |
6b3286ed KK |
122 | if (new_ns->mnt_ns) |
123 | put_mnt_ns(new_ns->mnt_ns); | |
25b21cb2 KK |
124 | out_ns: |
125 | tsk->nsproxy = old_ns; | |
5d124e99 | 126 | kfree(new_ns); |
25b21cb2 | 127 | goto out; |
ab516013 SH |
128 | } |
129 | ||
130 | void free_nsproxy(struct nsproxy *ns) | |
131 | { | |
6b3286ed KK |
132 | if (ns->mnt_ns) |
133 | put_mnt_ns(ns->mnt_ns); | |
4865ecf1 SH |
134 | if (ns->uts_ns) |
135 | put_uts_ns(ns->uts_ns); | |
25b21cb2 KK |
136 | if (ns->ipc_ns) |
137 | put_ipc_ns(ns->ipc_ns); | |
ab516013 SH |
138 | kfree(ns); |
139 | } |