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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> |
9a575a92 | 22 | #include <linux/pid_namespace.h> |
0437eb59 SH |
23 | |
24 | struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy); | |
ab516013 SH |
25 | |
26 | static inline void get_nsproxy(struct nsproxy *ns) | |
27 | { | |
28 | atomic_inc(&ns->count); | |
29 | } | |
30 | ||
31 | void get_task_namespaces(struct task_struct *tsk) | |
32 | { | |
33 | struct nsproxy *ns = tsk->nsproxy; | |
34 | if (ns) { | |
35 | get_nsproxy(ns); | |
36 | } | |
37 | } | |
38 | ||
39 | /* | |
40 | * creates a copy of "orig" with refcount 1. | |
41 | * This does not grab references to the contained namespaces, | |
42 | * so that needs to be done by dup_namespaces. | |
43 | */ | |
44 | static inline struct nsproxy *clone_namespaces(struct nsproxy *orig) | |
45 | { | |
46 | struct nsproxy *ns; | |
47 | ||
e05d722e | 48 | ns = kmemdup(orig, sizeof(struct nsproxy), GFP_KERNEL); |
5f8442ed | 49 | if (ns) |
ab516013 | 50 | atomic_set(&ns->count, 1); |
ab516013 SH |
51 | return ns; |
52 | } | |
53 | ||
54 | /* | |
55 | * copies the nsproxy, setting refcount to 1, and grabbing a | |
56 | * reference to all contained namespaces. Called from | |
57 | * sys_unshare() | |
58 | */ | |
59 | struct nsproxy *dup_namespaces(struct nsproxy *orig) | |
60 | { | |
61 | struct nsproxy *ns = clone_namespaces(orig); | |
62 | ||
1651e14e | 63 | if (ns) { |
6b3286ed KK |
64 | if (ns->mnt_ns) |
65 | get_mnt_ns(ns->mnt_ns); | |
4865ecf1 SH |
66 | if (ns->uts_ns) |
67 | get_uts_ns(ns->uts_ns); | |
25b21cb2 KK |
68 | if (ns->ipc_ns) |
69 | get_ipc_ns(ns->ipc_ns); | |
9a575a92 CLG |
70 | if (ns->pid_ns) |
71 | get_pid_ns(ns->pid_ns); | |
1651e14e SH |
72 | } |
73 | ||
ab516013 SH |
74 | return ns; |
75 | } | |
76 | ||
77 | /* | |
78 | * called from clone. This now handles copy for nsproxy and all | |
79 | * namespaces therein. | |
80 | */ | |
81 | int copy_namespaces(int flags, struct task_struct *tsk) | |
82 | { | |
83 | struct nsproxy *old_ns = tsk->nsproxy; | |
1651e14e SH |
84 | struct nsproxy *new_ns; |
85 | int err = 0; | |
ab516013 SH |
86 | |
87 | if (!old_ns) | |
88 | return 0; | |
89 | ||
90 | get_nsproxy(old_ns); | |
91 | ||
25b21cb2 | 92 | if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC))) |
1651e14e SH |
93 | return 0; |
94 | ||
95 | new_ns = clone_namespaces(old_ns); | |
96 | if (!new_ns) { | |
97 | err = -ENOMEM; | |
98 | goto out; | |
99 | } | |
100 | ||
101 | tsk->nsproxy = new_ns; | |
102 | ||
6b3286ed | 103 | err = copy_mnt_ns(flags, tsk); |
25b21cb2 KK |
104 | if (err) |
105 | goto out_ns; | |
1651e14e | 106 | |
4865ecf1 | 107 | err = copy_utsname(flags, tsk); |
25b21cb2 KK |
108 | if (err) |
109 | goto out_uts; | |
110 | ||
111 | err = copy_ipcs(flags, tsk); | |
112 | if (err) | |
113 | goto out_ipc; | |
4865ecf1 | 114 | |
9a575a92 CLG |
115 | err = copy_pid_ns(flags, tsk); |
116 | if (err) | |
117 | goto out_pid; | |
118 | ||
1651e14e | 119 | out: |
7a238fcb | 120 | put_and_finalize_nsproxy(old_ns); |
1651e14e | 121 | return err; |
25b21cb2 | 122 | |
9a575a92 CLG |
123 | out_pid: |
124 | if (new_ns->ipc_ns) | |
125 | put_ipc_ns(new_ns->ipc_ns); | |
25b21cb2 KK |
126 | out_ipc: |
127 | if (new_ns->uts_ns) | |
128 | put_uts_ns(new_ns->uts_ns); | |
129 | out_uts: | |
6b3286ed KK |
130 | if (new_ns->mnt_ns) |
131 | put_mnt_ns(new_ns->mnt_ns); | |
25b21cb2 KK |
132 | out_ns: |
133 | tsk->nsproxy = old_ns; | |
5d124e99 | 134 | kfree(new_ns); |
25b21cb2 | 135 | goto out; |
ab516013 SH |
136 | } |
137 | ||
7a238fcb SH |
138 | struct nsproxy *put_nsproxy(struct nsproxy *ns) |
139 | { | |
140 | if (ns) { | |
141 | if (atomic_dec_and_test(&ns->count)) { | |
142 | if (ns->mnt_ns) { | |
143 | put_mnt_ns(ns->mnt_ns); | |
144 | ns->mnt_ns = NULL; | |
145 | } | |
146 | return ns; | |
147 | } | |
148 | } | |
149 | return NULL; | |
150 | } | |
151 | ||
ab516013 SH |
152 | void free_nsproxy(struct nsproxy *ns) |
153 | { | |
9a575a92 CLG |
154 | if (ns->mnt_ns) |
155 | put_mnt_ns(ns->mnt_ns); | |
156 | if (ns->uts_ns) | |
157 | put_uts_ns(ns->uts_ns); | |
158 | if (ns->ipc_ns) | |
159 | put_ipc_ns(ns->ipc_ns); | |
160 | if (ns->pid_ns) | |
161 | put_pid_ns(ns->pid_ns); | |
162 | kfree(ns); | |
ab516013 | 163 | } |