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> | |
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 | ||
8467005d AD |
27 | struct nsproxy init_nsproxy = { |
28 | .count = ATOMIC_INIT(1), | |
29 | .uts_ns = &init_uts_ns, | |
30 | #if defined(CONFIG_POSIX_MQUEUE) || defined(CONFIG_SYSVIPC) | |
31 | .ipc_ns = &init_ipc_ns, | |
32 | #endif | |
33 | .mnt_ns = NULL, | |
34 | .pid_ns = &init_pid_ns, | |
35 | #ifdef CONFIG_NET | |
36 | .net_ns = &init_net, | |
37 | #endif | |
38 | }; | |
ab516013 | 39 | |
90af90d7 | 40 | static inline struct nsproxy *create_nsproxy(void) |
ab516013 | 41 | { |
90af90d7 | 42 | struct nsproxy *nsproxy; |
ab516013 | 43 | |
90af90d7 AD |
44 | nsproxy = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL); |
45 | if (nsproxy) | |
46 | atomic_set(&nsproxy->count, 1); | |
47 | return nsproxy; | |
ab516013 SH |
48 | } |
49 | ||
50 | /* | |
e3222c4e BP |
51 | * Create new nsproxy and all of its the associated namespaces. |
52 | * Return the newly created nsproxy. Do not attach this to the task, | |
53 | * leave it to the caller to do proper locking and attach it to task. | |
ab516013 | 54 | */ |
213dd266 EB |
55 | static struct nsproxy *create_new_namespaces(unsigned long flags, |
56 | struct task_struct *tsk, struct fs_struct *new_fs) | |
ab516013 | 57 | { |
e3222c4e | 58 | struct nsproxy *new_nsp; |
467e9f4b | 59 | int err; |
ab516013 | 60 | |
90af90d7 | 61 | new_nsp = create_nsproxy(); |
e3222c4e BP |
62 | if (!new_nsp) |
63 | return ERR_PTR(-ENOMEM); | |
1651e14e | 64 | |
e3222c4e | 65 | new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, new_fs); |
467e9f4b CLG |
66 | if (IS_ERR(new_nsp->mnt_ns)) { |
67 | err = PTR_ERR(new_nsp->mnt_ns); | |
e3222c4e | 68 | goto out_ns; |
467e9f4b | 69 | } |
e3222c4e BP |
70 | |
71 | new_nsp->uts_ns = copy_utsname(flags, tsk->nsproxy->uts_ns); | |
467e9f4b CLG |
72 | if (IS_ERR(new_nsp->uts_ns)) { |
73 | err = PTR_ERR(new_nsp->uts_ns); | |
e3222c4e | 74 | goto out_uts; |
467e9f4b | 75 | } |
e3222c4e BP |
76 | |
77 | new_nsp->ipc_ns = copy_ipcs(flags, tsk->nsproxy->ipc_ns); | |
467e9f4b CLG |
78 | if (IS_ERR(new_nsp->ipc_ns)) { |
79 | err = PTR_ERR(new_nsp->ipc_ns); | |
e3222c4e | 80 | goto out_ipc; |
467e9f4b | 81 | } |
e3222c4e | 82 | |
2894d650 | 83 | new_nsp->pid_ns = copy_pid_ns(flags, task_active_pid_ns(tsk)); |
467e9f4b CLG |
84 | if (IS_ERR(new_nsp->pid_ns)) { |
85 | err = PTR_ERR(new_nsp->pid_ns); | |
e3222c4e | 86 | goto out_pid; |
467e9f4b | 87 | } |
e3222c4e | 88 | |
9dd776b6 EB |
89 | new_nsp->net_ns = copy_net_ns(flags, tsk->nsproxy->net_ns); |
90 | if (IS_ERR(new_nsp->net_ns)) { | |
91 | err = PTR_ERR(new_nsp->net_ns); | |
92 | goto out_net; | |
93 | } | |
94 | ||
e3222c4e BP |
95 | return new_nsp; |
96 | ||
9dd776b6 | 97 | out_net: |
acce292c CLG |
98 | if (new_nsp->pid_ns) |
99 | put_pid_ns(new_nsp->pid_ns); | |
e3222c4e BP |
100 | out_pid: |
101 | if (new_nsp->ipc_ns) | |
102 | put_ipc_ns(new_nsp->ipc_ns); | |
103 | out_ipc: | |
104 | if (new_nsp->uts_ns) | |
105 | put_uts_ns(new_nsp->uts_ns); | |
106 | out_uts: | |
107 | if (new_nsp->mnt_ns) | |
108 | put_mnt_ns(new_nsp->mnt_ns); | |
109 | out_ns: | |
98c0d07c | 110 | kmem_cache_free(nsproxy_cachep, new_nsp); |
467e9f4b | 111 | return ERR_PTR(err); |
ab516013 SH |
112 | } |
113 | ||
114 | /* | |
115 | * called from clone. This now handles copy for nsproxy and all | |
116 | * namespaces therein. | |
117 | */ | |
213dd266 | 118 | int copy_namespaces(unsigned long flags, struct task_struct *tsk) |
ab516013 SH |
119 | { |
120 | struct nsproxy *old_ns = tsk->nsproxy; | |
1651e14e SH |
121 | struct nsproxy *new_ns; |
122 | int err = 0; | |
ab516013 SH |
123 | |
124 | if (!old_ns) | |
125 | return 0; | |
126 | ||
127 | get_nsproxy(old_ns); | |
128 | ||
30e49c26 | 129 | if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | |
18b6e041 | 130 | CLONE_NEWPID | CLONE_NEWNET))) |
1651e14e SH |
131 | return 0; |
132 | ||
e3222c4e BP |
133 | if (!capable(CAP_SYS_ADMIN)) { |
134 | err = -EPERM; | |
1651e14e SH |
135 | goto out; |
136 | } | |
137 | ||
02fdb36a SH |
138 | /* |
139 | * CLONE_NEWIPC must detach from the undolist: after switching | |
140 | * to a new ipc namespace, the semaphore arrays from the old | |
141 | * namespace are unreachable. In clone parlance, CLONE_SYSVSEM | |
142 | * means share undolist with parent, so we must forbid using | |
143 | * it along with CLONE_NEWIPC. | |
144 | */ | |
145 | if ((flags & CLONE_NEWIPC) && (flags & CLONE_SYSVSEM)) { | |
146 | err = -EINVAL; | |
147 | goto out; | |
148 | } | |
149 | ||
e3222c4e BP |
150 | new_ns = create_new_namespaces(flags, tsk, tsk->fs); |
151 | if (IS_ERR(new_ns)) { | |
152 | err = PTR_ERR(new_ns); | |
153 | goto out; | |
154 | } | |
9a575a92 | 155 | |
e3222c4e | 156 | tsk->nsproxy = new_ns; |
858d72ea | 157 | |
1651e14e | 158 | out: |
444f378b | 159 | put_nsproxy(old_ns); |
1651e14e | 160 | return err; |
ab516013 SH |
161 | } |
162 | ||
163 | void free_nsproxy(struct nsproxy *ns) | |
164 | { | |
9a575a92 CLG |
165 | if (ns->mnt_ns) |
166 | put_mnt_ns(ns->mnt_ns); | |
167 | if (ns->uts_ns) | |
168 | put_uts_ns(ns->uts_ns); | |
169 | if (ns->ipc_ns) | |
170 | put_ipc_ns(ns->ipc_ns); | |
171 | if (ns->pid_ns) | |
172 | put_pid_ns(ns->pid_ns); | |
9dd776b6 | 173 | put_net(ns->net_ns); |
98c0d07c | 174 | kmem_cache_free(nsproxy_cachep, ns); |
ab516013 | 175 | } |
e3222c4e BP |
176 | |
177 | /* | |
178 | * Called from unshare. Unshare all the namespaces part of nsproxy. | |
4e71e474 | 179 | * On success, returns the new nsproxy. |
e3222c4e BP |
180 | */ |
181 | int unshare_nsproxy_namespaces(unsigned long unshare_flags, | |
182 | struct nsproxy **new_nsp, struct fs_struct *new_fs) | |
183 | { | |
e3222c4e BP |
184 | int err = 0; |
185 | ||
77ec739d | 186 | if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | |
18b6e041 | 187 | CLONE_NEWNET))) |
e3222c4e BP |
188 | return 0; |
189 | ||
e3222c4e BP |
190 | if (!capable(CAP_SYS_ADMIN)) |
191 | return -EPERM; | |
192 | ||
e3222c4e BP |
193 | *new_nsp = create_new_namespaces(unshare_flags, current, |
194 | new_fs ? new_fs : current->fs); | |
858d72ea | 195 | if (IS_ERR(*new_nsp)) { |
e3222c4e | 196 | err = PTR_ERR(*new_nsp); |
858d72ea SH |
197 | goto out; |
198 | } | |
199 | ||
e885dcde | 200 | err = ns_cgroup_clone(current, task_pid(current)); |
858d72ea SH |
201 | if (err) |
202 | put_nsproxy(*new_nsp); | |
203 | ||
204 | out: | |
e3222c4e BP |
205 | return err; |
206 | } | |
98c0d07c | 207 | |
cf7b708c PE |
208 | void switch_task_namespaces(struct task_struct *p, struct nsproxy *new) |
209 | { | |
210 | struct nsproxy *ns; | |
211 | ||
212 | might_sleep(); | |
213 | ||
214 | ns = p->nsproxy; | |
215 | ||
216 | rcu_assign_pointer(p->nsproxy, new); | |
217 | ||
218 | if (ns && atomic_dec_and_test(&ns->count)) { | |
219 | /* | |
220 | * wait for others to get what they want from this nsproxy. | |
221 | * | |
222 | * cannot release this nsproxy via the call_rcu() since | |
223 | * put_mnt_ns() will want to sleep | |
224 | */ | |
225 | synchronize_rcu(); | |
226 | free_nsproxy(ns); | |
227 | } | |
228 | } | |
229 | ||
230 | void exit_task_namespaces(struct task_struct *p) | |
231 | { | |
232 | switch_task_namespaces(p, NULL); | |
233 | } | |
234 | ||
98c0d07c CLG |
235 | static int __init nsproxy_cache_init(void) |
236 | { | |
db8906da | 237 | nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC); |
98c0d07c CLG |
238 | return 0; |
239 | } | |
240 | ||
241 | module_init(nsproxy_cache_init); |