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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> | |
ab516013 | 17 | #include <linux/nsproxy.h> |
0437eb59 | 18 | #include <linux/init_task.h> |
6b3286ed | 19 | #include <linux/mnt_namespace.h> |
4865ecf1 | 20 | #include <linux/utsname.h> |
9a575a92 | 21 | #include <linux/pid_namespace.h> |
9dd776b6 | 22 | #include <net/net_namespace.h> |
ae5e1b22 | 23 | #include <linux/ipc_namespace.h> |
0437eb59 | 24 | |
98c0d07c CLG |
25 | static struct kmem_cache *nsproxy_cachep; |
26 | ||
0437eb59 | 27 | struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy); |
ab516013 | 28 | |
90af90d7 | 29 | static inline struct nsproxy *create_nsproxy(void) |
ab516013 | 30 | { |
90af90d7 | 31 | struct nsproxy *nsproxy; |
ab516013 | 32 | |
90af90d7 AD |
33 | nsproxy = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL); |
34 | if (nsproxy) | |
35 | atomic_set(&nsproxy->count, 1); | |
36 | return nsproxy; | |
ab516013 SH |
37 | } |
38 | ||
39 | /* | |
e3222c4e BP |
40 | * Create new nsproxy and all of its the associated namespaces. |
41 | * Return the newly created nsproxy. Do not attach this to the task, | |
42 | * leave it to the caller to do proper locking and attach it to task. | |
ab516013 | 43 | */ |
213dd266 EB |
44 | static struct nsproxy *create_new_namespaces(unsigned long flags, |
45 | struct task_struct *tsk, struct fs_struct *new_fs) | |
ab516013 | 46 | { |
e3222c4e | 47 | struct nsproxy *new_nsp; |
467e9f4b | 48 | int err; |
ab516013 | 49 | |
90af90d7 | 50 | new_nsp = create_nsproxy(); |
e3222c4e BP |
51 | if (!new_nsp) |
52 | return ERR_PTR(-ENOMEM); | |
1651e14e | 53 | |
e3222c4e | 54 | new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, new_fs); |
467e9f4b CLG |
55 | if (IS_ERR(new_nsp->mnt_ns)) { |
56 | err = PTR_ERR(new_nsp->mnt_ns); | |
e3222c4e | 57 | goto out_ns; |
467e9f4b | 58 | } |
e3222c4e BP |
59 | |
60 | new_nsp->uts_ns = copy_utsname(flags, tsk->nsproxy->uts_ns); | |
467e9f4b CLG |
61 | if (IS_ERR(new_nsp->uts_ns)) { |
62 | err = PTR_ERR(new_nsp->uts_ns); | |
e3222c4e | 63 | goto out_uts; |
467e9f4b | 64 | } |
e3222c4e BP |
65 | |
66 | new_nsp->ipc_ns = copy_ipcs(flags, tsk->nsproxy->ipc_ns); | |
467e9f4b CLG |
67 | if (IS_ERR(new_nsp->ipc_ns)) { |
68 | err = PTR_ERR(new_nsp->ipc_ns); | |
e3222c4e | 69 | goto out_ipc; |
467e9f4b | 70 | } |
e3222c4e | 71 | |
2894d650 | 72 | new_nsp->pid_ns = copy_pid_ns(flags, task_active_pid_ns(tsk)); |
467e9f4b CLG |
73 | if (IS_ERR(new_nsp->pid_ns)) { |
74 | err = PTR_ERR(new_nsp->pid_ns); | |
e3222c4e | 75 | goto out_pid; |
467e9f4b | 76 | } |
e3222c4e | 77 | |
9dd776b6 EB |
78 | new_nsp->net_ns = copy_net_ns(flags, tsk->nsproxy->net_ns); |
79 | if (IS_ERR(new_nsp->net_ns)) { | |
80 | err = PTR_ERR(new_nsp->net_ns); | |
81 | goto out_net; | |
82 | } | |
83 | ||
e3222c4e BP |
84 | return new_nsp; |
85 | ||
9dd776b6 | 86 | out_net: |
acce292c CLG |
87 | if (new_nsp->pid_ns) |
88 | put_pid_ns(new_nsp->pid_ns); | |
e3222c4e BP |
89 | out_pid: |
90 | if (new_nsp->ipc_ns) | |
91 | put_ipc_ns(new_nsp->ipc_ns); | |
92 | out_ipc: | |
93 | if (new_nsp->uts_ns) | |
94 | put_uts_ns(new_nsp->uts_ns); | |
95 | out_uts: | |
96 | if (new_nsp->mnt_ns) | |
97 | put_mnt_ns(new_nsp->mnt_ns); | |
98 | out_ns: | |
98c0d07c | 99 | kmem_cache_free(nsproxy_cachep, new_nsp); |
467e9f4b | 100 | return ERR_PTR(err); |
ab516013 SH |
101 | } |
102 | ||
103 | /* | |
104 | * called from clone. This now handles copy for nsproxy and all | |
105 | * namespaces therein. | |
106 | */ | |
213dd266 | 107 | int copy_namespaces(unsigned long flags, struct task_struct *tsk) |
ab516013 SH |
108 | { |
109 | struct nsproxy *old_ns = tsk->nsproxy; | |
1651e14e SH |
110 | struct nsproxy *new_ns; |
111 | int err = 0; | |
ab516013 SH |
112 | |
113 | if (!old_ns) | |
114 | return 0; | |
115 | ||
116 | get_nsproxy(old_ns); | |
117 | ||
30e49c26 | 118 | if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | |
18b6e041 | 119 | CLONE_NEWPID | CLONE_NEWNET))) |
1651e14e SH |
120 | return 0; |
121 | ||
e3222c4e BP |
122 | if (!capable(CAP_SYS_ADMIN)) { |
123 | err = -EPERM; | |
1651e14e SH |
124 | goto out; |
125 | } | |
126 | ||
02fdb36a SH |
127 | /* |
128 | * CLONE_NEWIPC must detach from the undolist: after switching | |
129 | * to a new ipc namespace, the semaphore arrays from the old | |
130 | * namespace are unreachable. In clone parlance, CLONE_SYSVSEM | |
131 | * means share undolist with parent, so we must forbid using | |
132 | * it along with CLONE_NEWIPC. | |
133 | */ | |
134 | if ((flags & CLONE_NEWIPC) && (flags & CLONE_SYSVSEM)) { | |
135 | err = -EINVAL; | |
136 | goto out; | |
137 | } | |
138 | ||
e3222c4e BP |
139 | new_ns = create_new_namespaces(flags, tsk, tsk->fs); |
140 | if (IS_ERR(new_ns)) { | |
141 | err = PTR_ERR(new_ns); | |
142 | goto out; | |
143 | } | |
9a575a92 | 144 | |
e3222c4e | 145 | tsk->nsproxy = new_ns; |
858d72ea | 146 | |
1651e14e | 147 | out: |
444f378b | 148 | put_nsproxy(old_ns); |
1651e14e | 149 | return err; |
ab516013 SH |
150 | } |
151 | ||
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); | |
9dd776b6 | 162 | put_net(ns->net_ns); |
98c0d07c | 163 | kmem_cache_free(nsproxy_cachep, ns); |
ab516013 | 164 | } |
e3222c4e BP |
165 | |
166 | /* | |
167 | * Called from unshare. Unshare all the namespaces part of nsproxy. | |
4e71e474 | 168 | * On success, returns the new nsproxy. |
e3222c4e BP |
169 | */ |
170 | int unshare_nsproxy_namespaces(unsigned long unshare_flags, | |
171 | struct nsproxy **new_nsp, struct fs_struct *new_fs) | |
172 | { | |
e3222c4e BP |
173 | int err = 0; |
174 | ||
77ec739d | 175 | if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | |
18b6e041 | 176 | CLONE_NEWNET))) |
e3222c4e BP |
177 | return 0; |
178 | ||
e3222c4e BP |
179 | if (!capable(CAP_SYS_ADMIN)) |
180 | return -EPERM; | |
181 | ||
e3222c4e BP |
182 | *new_nsp = create_new_namespaces(unshare_flags, current, |
183 | new_fs ? new_fs : current->fs); | |
858d72ea | 184 | if (IS_ERR(*new_nsp)) { |
e3222c4e | 185 | err = PTR_ERR(*new_nsp); |
858d72ea SH |
186 | goto out; |
187 | } | |
188 | ||
e885dcde | 189 | err = ns_cgroup_clone(current, task_pid(current)); |
858d72ea SH |
190 | if (err) |
191 | put_nsproxy(*new_nsp); | |
192 | ||
193 | out: | |
e3222c4e BP |
194 | return err; |
195 | } | |
98c0d07c | 196 | |
cf7b708c PE |
197 | void switch_task_namespaces(struct task_struct *p, struct nsproxy *new) |
198 | { | |
199 | struct nsproxy *ns; | |
200 | ||
201 | might_sleep(); | |
202 | ||
203 | ns = p->nsproxy; | |
204 | ||
205 | rcu_assign_pointer(p->nsproxy, new); | |
206 | ||
207 | if (ns && atomic_dec_and_test(&ns->count)) { | |
208 | /* | |
209 | * wait for others to get what they want from this nsproxy. | |
210 | * | |
211 | * cannot release this nsproxy via the call_rcu() since | |
212 | * put_mnt_ns() will want to sleep | |
213 | */ | |
214 | synchronize_rcu(); | |
215 | free_nsproxy(ns); | |
216 | } | |
217 | } | |
218 | ||
219 | void exit_task_namespaces(struct task_struct *p) | |
220 | { | |
221 | switch_task_namespaces(p, NULL); | |
222 | } | |
223 | ||
98c0d07c CLG |
224 | static int __init nsproxy_cache_init(void) |
225 | { | |
db8906da | 226 | nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC); |
98c0d07c CLG |
227 | return 0; |
228 | } | |
229 | ||
230 | module_init(nsproxy_cache_init); |