1/*
  2 *  Copyright (C) 2007
  3 *
  4 *  Author: Eric Biederman <ebiederm@xmision.com>
  5 *
  6 *  This program is free software; you can redistribute it and/or
  7 *  modify it under the terms of the GNU General Public License as
  8 *  published by the Free Software Foundation, version 2 of the
  9 *  License.
 10 */
 11
 12#include <linux/export.h>
 13#include <linux/uts.h>
 14#include <linux/utsname.h>
 15#include <linux/sysctl.h>
 16#include <linux/wait.h>
 17
 18#ifdef CONFIG_PROC_SYSCTL
 19
 20static void *get_uts(struct ctl_table *table, int write)
 21{
 22	char *which = table->data;
 23	struct uts_namespace *uts_ns;
 24
 25	uts_ns = current->nsproxy->uts_ns;
 26	which = (which - (char *)&init_uts_ns) + (char *)uts_ns;
 27
 28	if (!write)
 29		down_read(&uts_sem);
 30	else
 31		down_write(&uts_sem);
 32	return which;
 33}
 34
 35static void put_uts(struct ctl_table *table, int write, void *which)
 36{
 37	if (!write)
 38		up_read(&uts_sem);
 39	else
 40		up_write(&uts_sem);
 41}
 42
 43/*
 44 *	Special case of dostring for the UTS structure. This has locks
 45 *	to observe. Should this be in kernel/sys.c ????
 46 */
 47static int proc_do_uts_string(struct ctl_table *table, int write,
 48		  void __user *buffer, size_t *lenp, loff_t *ppos)
 49{
 50	struct ctl_table uts_table;
 51	int r;
 52	memcpy(&uts_table, table, sizeof(uts_table));
 53	uts_table.data = get_uts(table, write);
 54	r = proc_dostring(&uts_table, write, buffer, lenp, ppos);
 55	put_uts(table, write, uts_table.data);
 56
 57	if (write)
 58		proc_sys_poll_notify(table->poll);
 59
 60	return r;
 61}
 62#else
 63#define proc_do_uts_string NULL
 64#endif
 65
 66static DEFINE_CTL_TABLE_POLL(hostname_poll);
 67static DEFINE_CTL_TABLE_POLL(domainname_poll);
 68
 69static struct ctl_table uts_kern_table[] = {
 70	{
 71		.procname	= "ostype",
 72		.data		= init_uts_ns.name.sysname,
 73		.maxlen		= sizeof(init_uts_ns.name.sysname),
 74		.mode		= 0444,
 75		.proc_handler	= proc_do_uts_string,
 76	},
 77	{
 78		.procname	= "osrelease",
 79		.data		= init_uts_ns.name.release,
 80		.maxlen		= sizeof(init_uts_ns.name.release),
 81		.mode		= 0444,
 82		.proc_handler	= proc_do_uts_string,
 83	},
 84	{
 85		.procname	= "version",
 86		.data		= init_uts_ns.name.version,
 87		.maxlen		= sizeof(init_uts_ns.name.version),
 88		.mode		= 0444,
 89		.proc_handler	= proc_do_uts_string,
 90	},
 91	{
 92		.procname	= "hostname",
 93		.data		= init_uts_ns.name.nodename,
 94		.maxlen		= sizeof(init_uts_ns.name.nodename),
 95		.mode		= 0644,
 96		.proc_handler	= proc_do_uts_string,
 97		.poll		= &hostname_poll,
 98	},
 99	{
100		.procname	= "domainname",
101		.data		= init_uts_ns.name.domainname,
102		.maxlen		= sizeof(init_uts_ns.name.domainname),
103		.mode		= 0644,
104		.proc_handler	= proc_do_uts_string,
105		.poll		= &domainname_poll,
106	},
107	{}
108};
109
110static struct ctl_table uts_root_table[] = {
111	{
112		.procname	= "kernel",
113		.mode		= 0555,
114		.child		= uts_kern_table,
115	},
116	{}
117};
118
119#ifdef CONFIG_PROC_SYSCTL
120/*
121 * Notify userspace about a change in a certain entry of uts_kern_table,
122 * identified by the parameter proc.
123 */
124void uts_proc_notify(enum uts_proc proc)
125{
126	struct ctl_table *table = &uts_kern_table[proc];
127
128	proc_sys_poll_notify(table->poll);
129}
130#endif
131
132static int __init utsname_sysctl_init(void)
133{
134	register_sysctl_table(uts_root_table);
135	return 0;
136}
137
138device_initcall(utsname_sysctl_init);

  1/*
  2 *  Copyright (C) 2007
  3 *
  4 *  Author: Eric Biederman <ebiederm@xmision.com>
  5 *
  6 *  This program is free software; you can redistribute it and/or
  7 *  modify it under the terms of the GNU General Public License as
  8 *  published by the Free Software Foundation, version 2 of the
  9 *  License.
 10 */
 11
 12#include <linux/export.h>
 13#include <linux/uts.h>
 14#include <linux/utsname.h>
 15#include <linux/sysctl.h>
 16#include <linux/wait.h>
 17
 18#ifdef CONFIG_PROC_SYSCTL
 19
 20static void *get_uts(ctl_table *table, int write)
 21{
 22	char *which = table->data;
 23	struct uts_namespace *uts_ns;
 24
 25	uts_ns = current->nsproxy->uts_ns;
 26	which = (which - (char *)&init_uts_ns) + (char *)uts_ns;
 27
 28	if (!write)
 29		down_read(&uts_sem);
 30	else
 31		down_write(&uts_sem);
 32	return which;
 33}
 34
 35static void put_uts(ctl_table *table, int write, void *which)
 36{
 37	if (!write)
 38		up_read(&uts_sem);
 39	else
 40		up_write(&uts_sem);
 41}
 42
 43/*
 44 *	Special case of dostring for the UTS structure. This has locks
 45 *	to observe. Should this be in kernel/sys.c ????
 46 */
 47static int proc_do_uts_string(ctl_table *table, int write,
 48		  void __user *buffer, size_t *lenp, loff_t *ppos)
 49{
 50	struct ctl_table uts_table;
 51	int r;
 52	memcpy(&uts_table, table, sizeof(uts_table));
 53	uts_table.data = get_uts(table, write);
 54	r = proc_dostring(&uts_table,write,buffer,lenp, ppos);
 55	put_uts(table, write, uts_table.data);
 56
 57	if (write)
 58		proc_sys_poll_notify(table->poll);
 59
 60	return r;
 61}
 62#else
 63#define proc_do_uts_string NULL
 64#endif
 65
 66static DEFINE_CTL_TABLE_POLL(hostname_poll);
 67static DEFINE_CTL_TABLE_POLL(domainname_poll);
 68
 69static struct ctl_table uts_kern_table[] = {
 70	{
 71		.procname	= "ostype",
 72		.data		= init_uts_ns.name.sysname,
 73		.maxlen		= sizeof(init_uts_ns.name.sysname),
 74		.mode		= 0444,
 75		.proc_handler	= proc_do_uts_string,
 76	},
 77	{
 78		.procname	= "osrelease",
 79		.data		= init_uts_ns.name.release,
 80		.maxlen		= sizeof(init_uts_ns.name.release),
 81		.mode		= 0444,
 82		.proc_handler	= proc_do_uts_string,
 83	},
 84	{
 85		.procname	= "version",
 86		.data		= init_uts_ns.name.version,
 87		.maxlen		= sizeof(init_uts_ns.name.version),
 88		.mode		= 0444,
 89		.proc_handler	= proc_do_uts_string,
 90	},
 91	{
 92		.procname	= "hostname",
 93		.data		= init_uts_ns.name.nodename,
 94		.maxlen		= sizeof(init_uts_ns.name.nodename),
 95		.mode		= 0644,
 96		.proc_handler	= proc_do_uts_string,
 97		.poll		= &hostname_poll,
 98	},
 99	{
100		.procname	= "domainname",
101		.data		= init_uts_ns.name.domainname,
102		.maxlen		= sizeof(init_uts_ns.name.domainname),
103		.mode		= 0644,
104		.proc_handler	= proc_do_uts_string,
105		.poll		= &domainname_poll,
106	},
107	{}
108};
109
110static struct ctl_table uts_root_table[] = {
111	{
112		.procname	= "kernel",
113		.mode		= 0555,
114		.child		= uts_kern_table,
115	},
116	{}
117};
118
119#ifdef CONFIG_PROC_SYSCTL
120/*
121 * Notify userspace about a change in a certain entry of uts_kern_table,
122 * identified by the parameter proc.
123 */
124void uts_proc_notify(enum uts_proc proc)
125{
126	struct ctl_table *table = &uts_kern_table[proc];
127
128	proc_sys_poll_notify(table->poll);
129}
130#endif
131
132static int __init utsname_sysctl_init(void)
133{
134	register_sysctl_table(uts_root_table);
135	return 0;
136}
137
138__initcall(utsname_sysctl_init);