2 * Copyright (C) 2006 IBM Corporation
4 * Author: Serge Hallyn <serue@us.ibm.com>
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
11 * Jun 2006 - namespaces support
13 * Pavel Emelianov <xemul@openvz.org>
16 #include <linux/module.h>
17 #include <linux/version.h>
18 #include <linux/nsproxy.h>
19 #include <linux/init_task.h>
20 #include <linux/mnt_namespace.h>
21 #include <linux/utsname.h>
22 #include <linux/pid_namespace.h>
24 static struct kmem_cache *nsproxy_cachep;
26 struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
28 static inline void get_nsproxy(struct nsproxy *ns)
30 atomic_inc(&ns->count);
33 void get_task_namespaces(struct task_struct *tsk)
35 struct nsproxy *ns = tsk->nsproxy;
42 * creates a copy of "orig" with refcount 1.
44 static inline struct nsproxy *clone_nsproxy(struct nsproxy *orig)
48 ns = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL);
50 memcpy(ns, orig, sizeof(struct nsproxy));
51 atomic_set(&ns->count, 1);
57 * Create new nsproxy and all of its the associated namespaces.
58 * Return the newly created nsproxy. Do not attach this to the task,
59 * leave it to the caller to do proper locking and attach it to task.
61 static struct nsproxy *create_new_namespaces(unsigned long flags,
62 struct task_struct *tsk, struct fs_struct *new_fs)
64 struct nsproxy *new_nsp;
67 new_nsp = clone_nsproxy(tsk->nsproxy);
69 return ERR_PTR(-ENOMEM);
71 new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, new_fs);
72 if (IS_ERR(new_nsp->mnt_ns)) {
73 err = PTR_ERR(new_nsp->mnt_ns);
77 new_nsp->uts_ns = copy_utsname(flags, tsk->nsproxy->uts_ns);
78 if (IS_ERR(new_nsp->uts_ns)) {
79 err = PTR_ERR(new_nsp->uts_ns);
83 new_nsp->ipc_ns = copy_ipcs(flags, tsk->nsproxy->ipc_ns);
84 if (IS_ERR(new_nsp->ipc_ns)) {
85 err = PTR_ERR(new_nsp->ipc_ns);
89 new_nsp->pid_ns = copy_pid_ns(flags, tsk->nsproxy->pid_ns);
90 if (IS_ERR(new_nsp->pid_ns)) {
91 err = PTR_ERR(new_nsp->pid_ns);
95 new_nsp->user_ns = copy_user_ns(flags, tsk->nsproxy->user_ns);
96 if (IS_ERR(new_nsp->user_ns)) {
97 err = PTR_ERR(new_nsp->user_ns);
105 put_pid_ns(new_nsp->pid_ns);
108 put_ipc_ns(new_nsp->ipc_ns);
111 put_uts_ns(new_nsp->uts_ns);
114 put_mnt_ns(new_nsp->mnt_ns);
116 kmem_cache_free(nsproxy_cachep, new_nsp);
121 * called from clone. This now handles copy for nsproxy and all
122 * namespaces therein.
124 int copy_namespaces(unsigned long flags, struct task_struct *tsk)
126 struct nsproxy *old_ns = tsk->nsproxy;
127 struct nsproxy *new_ns;
135 if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | CLONE_NEWUSER)))
138 if (!capable(CAP_SYS_ADMIN)) {
143 new_ns = create_new_namespaces(flags, tsk, tsk->fs);
144 if (IS_ERR(new_ns)) {
145 err = PTR_ERR(new_ns);
149 tsk->nsproxy = new_ns;
155 void free_nsproxy(struct nsproxy *ns)
158 put_mnt_ns(ns->mnt_ns);
160 put_uts_ns(ns->uts_ns);
162 put_ipc_ns(ns->ipc_ns);
164 put_pid_ns(ns->pid_ns);
166 put_user_ns(ns->user_ns);
167 kmem_cache_free(nsproxy_cachep, ns);
171 * Called from unshare. Unshare all the namespaces part of nsproxy.
172 * On success, returns the new nsproxy.
174 int unshare_nsproxy_namespaces(unsigned long unshare_flags,
175 struct nsproxy **new_nsp, struct fs_struct *new_fs)
179 if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
183 if (!capable(CAP_SYS_ADMIN))
186 *new_nsp = create_new_namespaces(unshare_flags, current,
187 new_fs ? new_fs : current->fs);
188 if (IS_ERR(*new_nsp))
189 err = PTR_ERR(*new_nsp);
193 static int __init nsproxy_cache_init(void)
195 nsproxy_cachep = kmem_cache_create("nsproxy", sizeof(struct nsproxy),
196 0, SLAB_PANIC, NULL, NULL);
200 module_init(nsproxy_cache_init);