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![Eric W. Biederman](/assets/img/avatar_default.png)
This patch allows you to create a new network namespace using sys_clone, or sys_unshare. As the network namespace is still experimental and under development clone and unshare support is only made available when CONFIG_NET_NS is selected at compile time. As this patch introduces network namespace support into code paths that exist when the CONFIG_NET is not selected there are a few additions made to net_namespace.h to allow a few more functions to be used when the networking stack is not compiled in. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
211 lines
4.6 KiB
C
211 lines
4.6 KiB
C
/*
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* Copyright (C) 2006 IBM Corporation
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*
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* Author: Serge Hallyn <serue@us.ibm.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, version 2 of the
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* License.
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*
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* Jun 2006 - namespaces support
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* OpenVZ, SWsoft Inc.
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* Pavel Emelianov <xemul@openvz.org>
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*/
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#include <linux/module.h>
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#include <linux/version.h>
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#include <linux/nsproxy.h>
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#include <linux/init_task.h>
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#include <linux/mnt_namespace.h>
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#include <linux/utsname.h>
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#include <linux/pid_namespace.h>
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#include <net/net_namespace.h>
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static struct kmem_cache *nsproxy_cachep;
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struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
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static inline void get_nsproxy(struct nsproxy *ns)
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{
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atomic_inc(&ns->count);
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}
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void get_task_namespaces(struct task_struct *tsk)
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{
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struct nsproxy *ns = tsk->nsproxy;
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if (ns) {
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get_nsproxy(ns);
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}
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}
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/*
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* creates a copy of "orig" with refcount 1.
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*/
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static inline struct nsproxy *clone_nsproxy(struct nsproxy *orig)
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{
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struct nsproxy *ns;
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ns = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL);
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if (ns) {
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memcpy(ns, orig, sizeof(struct nsproxy));
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atomic_set(&ns->count, 1);
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}
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return ns;
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}
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/*
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* Create new nsproxy and all of its the associated namespaces.
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* Return the newly created nsproxy. Do not attach this to the task,
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* leave it to the caller to do proper locking and attach it to task.
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*/
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static struct nsproxy *create_new_namespaces(unsigned long flags,
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struct task_struct *tsk, struct fs_struct *new_fs)
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{
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struct nsproxy *new_nsp;
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int err;
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new_nsp = clone_nsproxy(tsk->nsproxy);
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if (!new_nsp)
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return ERR_PTR(-ENOMEM);
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new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, new_fs);
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if (IS_ERR(new_nsp->mnt_ns)) {
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err = PTR_ERR(new_nsp->mnt_ns);
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goto out_ns;
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}
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new_nsp->uts_ns = copy_utsname(flags, tsk->nsproxy->uts_ns);
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if (IS_ERR(new_nsp->uts_ns)) {
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err = PTR_ERR(new_nsp->uts_ns);
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goto out_uts;
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}
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new_nsp->ipc_ns = copy_ipcs(flags, tsk->nsproxy->ipc_ns);
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if (IS_ERR(new_nsp->ipc_ns)) {
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err = PTR_ERR(new_nsp->ipc_ns);
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goto out_ipc;
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}
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new_nsp->pid_ns = copy_pid_ns(flags, tsk->nsproxy->pid_ns);
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if (IS_ERR(new_nsp->pid_ns)) {
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err = PTR_ERR(new_nsp->pid_ns);
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goto out_pid;
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}
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new_nsp->user_ns = copy_user_ns(flags, tsk->nsproxy->user_ns);
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if (IS_ERR(new_nsp->user_ns)) {
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err = PTR_ERR(new_nsp->user_ns);
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goto out_user;
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}
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new_nsp->net_ns = copy_net_ns(flags, tsk->nsproxy->net_ns);
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if (IS_ERR(new_nsp->net_ns)) {
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err = PTR_ERR(new_nsp->net_ns);
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goto out_net;
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}
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return new_nsp;
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out_net:
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if (new_nsp->user_ns)
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put_user_ns(new_nsp->user_ns);
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out_user:
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if (new_nsp->pid_ns)
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put_pid_ns(new_nsp->pid_ns);
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out_pid:
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if (new_nsp->ipc_ns)
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put_ipc_ns(new_nsp->ipc_ns);
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out_ipc:
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if (new_nsp->uts_ns)
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put_uts_ns(new_nsp->uts_ns);
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out_uts:
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if (new_nsp->mnt_ns)
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put_mnt_ns(new_nsp->mnt_ns);
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out_ns:
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kmem_cache_free(nsproxy_cachep, new_nsp);
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return ERR_PTR(err);
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}
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/*
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* called from clone. This now handles copy for nsproxy and all
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* namespaces therein.
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*/
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int copy_namespaces(unsigned long flags, struct task_struct *tsk)
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{
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struct nsproxy *old_ns = tsk->nsproxy;
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struct nsproxy *new_ns;
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int err = 0;
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if (!old_ns)
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return 0;
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get_nsproxy(old_ns);
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if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | CLONE_NEWUSER | CLONE_NEWNET)))
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return 0;
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if (!capable(CAP_SYS_ADMIN)) {
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err = -EPERM;
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goto out;
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}
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new_ns = create_new_namespaces(flags, tsk, tsk->fs);
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if (IS_ERR(new_ns)) {
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err = PTR_ERR(new_ns);
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goto out;
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}
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tsk->nsproxy = new_ns;
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out:
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put_nsproxy(old_ns);
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return err;
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}
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void free_nsproxy(struct nsproxy *ns)
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{
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if (ns->mnt_ns)
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put_mnt_ns(ns->mnt_ns);
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if (ns->uts_ns)
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put_uts_ns(ns->uts_ns);
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if (ns->ipc_ns)
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put_ipc_ns(ns->ipc_ns);
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if (ns->pid_ns)
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put_pid_ns(ns->pid_ns);
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if (ns->user_ns)
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put_user_ns(ns->user_ns);
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put_net(ns->net_ns);
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kmem_cache_free(nsproxy_cachep, ns);
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}
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/*
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* Called from unshare. Unshare all the namespaces part of nsproxy.
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* On success, returns the new nsproxy.
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*/
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int unshare_nsproxy_namespaces(unsigned long unshare_flags,
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struct nsproxy **new_nsp, struct fs_struct *new_fs)
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{
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int err = 0;
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if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
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CLONE_NEWUSER | CLONE_NEWNET)))
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return 0;
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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*new_nsp = create_new_namespaces(unshare_flags, current,
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new_fs ? new_fs : current->fs);
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if (IS_ERR(*new_nsp))
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err = PTR_ERR(*new_nsp);
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return err;
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}
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static int __init nsproxy_cache_init(void)
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{
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nsproxy_cachep = kmem_cache_create("nsproxy", sizeof(struct nsproxy),
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0, SLAB_PANIC, NULL);
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return 0;
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}
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module_init(nsproxy_cache_init);
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