/* *  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>#include <linux/pid_namespace.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. */static inline struct nsproxy *clone_nsproxy(struct nsproxy *orig){	struct nsproxy *ns; 	ns = kmemdup(orig, sizeof(struct nsproxy), GFP_KERNEL);	if (ns)		atomic_set(&ns->count, 1);	return ns;} /* * Create new nsproxy and all of its the associated namespaces. * Return the newly created nsproxy.  Do not attach this to the task, * leave it to the caller to do proper locking and attach it to task. */static struct nsproxy *create_new_namespaces(int flags, struct task_struct *tsk,			struct fs_struct *new_fs){	struct nsproxy *new_nsp; 	new_nsp = clone_nsproxy(tsk->nsproxy);	if (!new_nsp)		return ERR_PTR(-ENOMEM); 	new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, new_fs);	if (IS_ERR(new_nsp->mnt_ns))		goto out_ns; 	new_nsp->uts_ns = copy_utsname(flags, tsk->nsproxy->uts_ns);	if (IS_ERR(new_nsp->uts_ns))		goto out_uts; 	new_nsp->ipc_ns = copy_ipcs(flags, tsk->nsproxy->ipc_ns);	if (IS_ERR(new_nsp->ipc_ns))		goto out_ipc; 	new_nsp->pid_ns = copy_pid_ns(flags, tsk->nsproxy->pid_ns);	if (IS_ERR(new_nsp->pid_ns))		goto out_pid; 	return new_nsp; out_pid:	if (new_nsp->ipc_ns)		put_ipc_ns(new_nsp->ipc_ns);out_ipc:	if (new_nsp->uts_ns)		put_uts_ns(new_nsp->uts_ns);out_uts:	if (new_nsp->mnt_ns)		put_mnt_ns(new_nsp->mnt_ns);out_ns:	kfree(new_nsp);	return ERR_PTR(-ENOMEM);} /* * 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; 	if (!capable(CAP_SYS_ADMIN)) {		err = -EPERM;		goto out;	} 	new_ns = create_new_namespaces(flags, tsk, tsk->fs);	if (IS_ERR(new_ns)) {		err = PTR_ERR(new_ns);		goto out;	} 	tsk->nsproxy = new_ns;out:	put_nsproxy(old_ns);	return err;} 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);	if (ns->pid_ns)		put_pid_ns(ns->pid_ns);	kfree(ns);} /* * Called from unshare. Unshare all the namespaces part of nsproxy. * On sucess, returns the new nsproxy and a reference to old nsproxy * to make sure it stays around. */int unshare_nsproxy_namespaces(unsigned long unshare_flags,		struct nsproxy **new_nsp, struct fs_struct *new_fs){	struct nsproxy *old_ns = current->nsproxy;	int err = 0; 	if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC)))		return 0; #ifndef CONFIG_IPC_NS	if (unshare_flags & CLONE_NEWIPC)		return -EINVAL;#endif #ifndef CONFIG_UTS_NS	if (unshare_flags & CLONE_NEWUTS)		return -EINVAL;#endif 	if (!capable(CAP_SYS_ADMIN))		return -EPERM; 	get_nsproxy(old_ns); 	*new_nsp = create_new_namespaces(unshare_flags, current,				new_fs ? new_fs : current->fs);	if (IS_ERR(*new_nsp)) {		err = PTR_ERR(*new_nsp);		put_nsproxy(old_ns);	}	return err;}