/* *  Copyright (C) 2007 * *  Author: Eric Biederman <ebiederm@xmision.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. */ #include <linux/module.h>#include <linux/uts.h>#include <linux/utsname.h>#include <linux/sysctl.h> static void *get_uts(ctl_table *table, int write){	char *which = table->data;	struct uts_namespace *uts_ns; 	uts_ns = current->nsproxy->uts_ns;	which = (which - (char *)&init_uts_ns) + (char *)uts_ns; 	if (!write)		down_read(&uts_sem);	else		down_write(&uts_sem);	return which;} static void put_uts(ctl_table *table, int write, void *which){	if (!write)		up_read(&uts_sem);	else		up_write(&uts_sem);} #ifdef CONFIG_PROC_FS/* *	Special case of dostring for the UTS structure. This has locks *	to observe. Should this be in kernel/sys.c ???? */static int proc_do_uts_string(ctl_table *table, int write, struct file *filp,		  void __user *buffer, size_t *lenp, loff_t *ppos){	struct ctl_table uts_table;	int r;	memcpy(&uts_table, table, sizeof(uts_table));	uts_table.data = get_uts(table, write);	r = proc_dostring(&uts_table,write,filp,buffer,lenp, ppos);	put_uts(table, write, uts_table.data);	return r;}#else#define proc_do_uts_string NULL#endif  #ifdef CONFIG_SYSCTL_SYSCALL/* The generic string strategy routine: */static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen,		  void __user *oldval, size_t __user *oldlenp,		  void __user *newval, size_t newlen){	struct ctl_table uts_table;	int r, write;	write = newval && newlen;	memcpy(&uts_table, table, sizeof(uts_table));	uts_table.data = get_uts(table, write);	r = sysctl_string(&uts_table, name, nlen,		oldval, oldlenp, newval, newlen);	put_uts(table, write, uts_table.data);	return r;}#else#define sysctl_uts_string NULL#endif static struct ctl_table uts_kern_table[] = {	{		.ctl_name	= KERN_OSTYPE,		.procname	= "ostype",		.data		= init_uts_ns.name.sysname,		.maxlen		= sizeof(init_uts_ns.name.sysname),		.mode		= 0444,		.proc_handler	= proc_do_uts_string,		.strategy	= sysctl_uts_string,	},	{		.ctl_name	= KERN_OSRELEASE,		.procname	= "osrelease",		.data		= init_uts_ns.name.release,		.maxlen		= sizeof(init_uts_ns.name.release),		.mode		= 0444,		.proc_handler	= proc_do_uts_string,		.strategy	= sysctl_uts_string,	},	{		.ctl_name	= KERN_VERSION,		.procname	= "version",		.data		= init_uts_ns.name.version,		.maxlen		= sizeof(init_uts_ns.name.version),		.mode		= 0444,		.proc_handler	= proc_do_uts_string,		.strategy	= sysctl_uts_string,	},	{		.ctl_name	= KERN_NODENAME,		.procname	= "hostname",		.data		= init_uts_ns.name.nodename,		.maxlen		= sizeof(init_uts_ns.name.nodename),		.mode		= 0644,		.proc_handler	= proc_do_uts_string,		.strategy	= sysctl_uts_string,	},	{		.ctl_name	= KERN_DOMAINNAME,		.procname	= "domainname",		.data		= init_uts_ns.name.domainname,		.maxlen		= sizeof(init_uts_ns.name.domainname),		.mode		= 0644,		.proc_handler	= proc_do_uts_string,		.strategy	= sysctl_uts_string,	},	{}}; static struct ctl_table uts_root_table[] = {	{		.ctl_name	= CTL_KERN,		.procname	= "kernel",		.mode		= 0555,		.child		= uts_kern_table,	},	{}}; static int __init utsname_sysctl_init(void){	register_sysctl_table(uts_root_table);	return 0;} __initcall(utsname_sysctl_init);