| /* |
| * Copyright (C) 2006 IBM Corporation |
| * |
| * Author: Serge Hallyn <serue@us.ibm.com> |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License as |
| * published by the Free Software Foundation, version 2 of the |
| * License. |
| * |
| * Jun 2006 - namespaces support |
| * OpenVZ, SWsoft Inc. |
| * Pavel Emelianov <xemul@openvz.org> |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/version.h> |
| #include <linux/nsproxy.h> |
| #include <linux/init_task.h> |
| #include <linux/mnt_namespace.h> |
| #include <linux/utsname.h> |
| |
| struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy); |
| |
| static inline void get_nsproxy(struct nsproxy *ns) |
| { |
| atomic_inc(&ns->count); |
| } |
| |
| void get_task_namespaces(struct task_struct *tsk) |
| { |
| struct nsproxy *ns = tsk->nsproxy; |
| if (ns) { |
| get_nsproxy(ns); |
| } |
| } |
| |
| /* |
| * creates a copy of "orig" with refcount 1. |
| * This does not grab references to the contained namespaces, |
| * so that needs to be done by dup_namespaces. |
| */ |
| static inline struct nsproxy *clone_namespaces(struct nsproxy *orig) |
| { |
| struct nsproxy *ns; |
| |
| ns = kmemdup(orig, sizeof(struct nsproxy), GFP_KERNEL); |
| if (ns) { |
| atomic_set(&ns->count, 1); |
| ns->id = -1; |
| } |
| return ns; |
| } |
| |
| /* |
| * copies the nsproxy, setting refcount to 1, and grabbing a |
| * reference to all contained namespaces. Called from |
| * sys_unshare() |
| */ |
| struct nsproxy *dup_namespaces(struct nsproxy *orig) |
| { |
| struct nsproxy *ns = clone_namespaces(orig); |
| |
| if (ns) { |
| if (ns->mnt_ns) |
| get_mnt_ns(ns->mnt_ns); |
| if (ns->uts_ns) |
| get_uts_ns(ns->uts_ns); |
| if (ns->ipc_ns) |
| get_ipc_ns(ns->ipc_ns); |
| } |
| |
| return ns; |
| } |
| |
| /* |
| * called from clone. This now handles copy for nsproxy and all |
| * namespaces therein. |
| */ |
| int copy_namespaces(int flags, struct task_struct *tsk) |
| { |
| struct nsproxy *old_ns = tsk->nsproxy; |
| struct nsproxy *new_ns; |
| int err = 0; |
| |
| if (!old_ns) |
| return 0; |
| |
| get_nsproxy(old_ns); |
| |
| if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC))) |
| return 0; |
| |
| new_ns = clone_namespaces(old_ns); |
| if (!new_ns) { |
| err = -ENOMEM; |
| goto out; |
| } |
| |
| tsk->nsproxy = new_ns; |
| |
| err = copy_mnt_ns(flags, tsk); |
| if (err) |
| goto out_ns; |
| |
| err = copy_utsname(flags, tsk); |
| if (err) |
| goto out_uts; |
| |
| err = copy_ipcs(flags, tsk); |
| if (err) |
| goto out_ipc; |
| |
| out: |
| put_nsproxy(old_ns); |
| return err; |
| |
| out_ipc: |
| if (new_ns->uts_ns) |
| put_uts_ns(new_ns->uts_ns); |
| out_uts: |
| if (new_ns->mnt_ns) |
| put_mnt_ns(new_ns->mnt_ns); |
| out_ns: |
| tsk->nsproxy = old_ns; |
| kfree(new_ns); |
| goto out; |
| } |
| |
| void free_nsproxy(struct nsproxy *ns) |
| { |
| if (ns->mnt_ns) |
| put_mnt_ns(ns->mnt_ns); |
| if (ns->uts_ns) |
| put_uts_ns(ns->uts_ns); |
| if (ns->ipc_ns) |
| put_ipc_ns(ns->ipc_ns); |
| kfree(ns); |
| } |