/*
* 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);
