/* *  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/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);	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->namespace)			get_namespace(ns->namespace);		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_namespace(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->namespace)		put_namespace(new_ns->namespace);out_ns:	tsk->nsproxy = old_ns;	kfree(new_ns);	goto out;} void free_nsproxy(struct nsproxy *ns){		if (ns->namespace)			put_namespace(ns->namespace);		if (ns->uts_ns)			put_uts_ns(ns->uts_ns);		if (ns->ipc_ns)			put_ipc_ns(ns->ipc_ns);		kfree(ns);}