/*
* proc sysctl test driver
*
* Copyright (C) 2017 Luis R. Rodriguez <mcgrof@kernel.org>
*
* 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; either version 2 of the License, or at your option any
* later version; or, when distributed separately from the Linux kernel or
* when incorporated into other software packages, subject to the following
* license:
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of copyleft-next (version 0.3.1 or later) as published
* at http://copyleft-next.org/.
*/
/*
* This module provides an interface to the the proc sysctl interfaces. This
* driver requires CONFIG_PROC_SYSCTL. It will not normally be loaded by the
* system unless explicitly requested by name. You can also build this driver
* into your kernel.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/init.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/printk.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/async.h>
#include <linux/delay.h>
#include <linux/vmalloc.h>
static int i_zero;
static int i_one_hundred = 100;
struct test_sysctl_data {
int int_0001;
int int_0002;
int int_0003[4];
unsigned int uint_0001;
char string_0001[65];
#define SYSCTL_TEST_BITMAP_SIZE 65536
unsigned long *bitmap_0001;
};
static struct test_sysctl_data test_data = {
.int_0001 = 60,
.int_0002 = 1,
.int_0003[0] = 0,
.int_0003[1] = 1,
.int_0003[2] = 2,
.int_0003[3] = 3,
.uint_0001 = 314,
.string_0001 = "(none)",
};
/* These are all under /proc/sys/debug/test_sysctl/ */
static struct ctl_table test_table[] = {
{
.procname = "int_0001",
.data = &test_data.int_0001,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &i_zero,
.extra2 = &i_one_hundred,
},
{
.procname = "int_0002",
.data = &test_data.int_0002,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "int_0003",
.data = &test_data.int_0003,
.maxlen = sizeof(test_data.int_0003),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "uint_0001",
.data = &test_data.uint_0001,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_douintvec,
},
{
.procname = "string_0001",
.data = &test_data.string_0001,
.maxlen = sizeof(test_data.string_0001),
.mode = 0644,
.proc_handler = proc_dostring,
},
{
.procname = "bitmap_0001",
.data = &test_data.bitmap_0001,
.maxlen = SYSCTL_TEST_BITMAP_SIZE,
.mode = 0644,
.proc_handler = proc_do_large_bitmap,
},
{ }
};
static struct ctl_table test_sysctl_table[] = {
{
.procname = "test_sysctl",
.maxlen = 0,
.mode = 0555,
.child = test_table,
},
{ }
};
static struct ctl_table test_sysctl_root_table[] = {
{
.procname = "debug",
.maxlen = 0,
.mode = 0555,
.child = test_sysctl_table,
},
{ }
};
static struct ctl_table_header *test_sysctl_header;
static int __init test_sysctl_init(void)
{
test_data.bitmap_0001 = kzalloc(SYSCTL_TEST_BITMAP_SIZE/8, GFP_KERNEL);
if (!test_data.bitmap_0001)
return -ENOMEM;
test_sysctl_header = register_sysctl_table(test_sysctl_root_table);
if (!test_sysctl_header) {
kfree(test_data.bitmap_0001);
return -ENOMEM;
}
return 0;
}
late_initcall(test_sysctl_init);
static void __exit test_sysctl_exit(void)
{
kfree(test_data.bitmap_0001);
if (test_sysctl_header)
unregister_sysctl_table(test_sysctl_header);
}
module_exit(test_sysctl_exit);
MODULE_AUTHOR("Luis R. Rodriguez <mcgrof@kernel.org>");
MODULE_LICENSE("GPL");
