[mirror_ubuntu-bionic-kernel.git] / net / phonet / sysctl.c

/*
 * File: sysctl.c
 *
 * Phonet /proc/sys/net/phonet interface implementation
 *
 * Copyright (C) 2008 Nokia Corporation.
 *
 * Author: Rémi Denis-Courmont
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 */

#include <linux/seqlock.h>
#include <linux/sysctl.h>
#include <linux/errno.h>
#include <linux/init.h>

#include <net/sock.h>
#include <linux/phonet.h>
#include <net/phonet/phonet.h>

#define DYNAMIC_PORT_MIN	0x40
#define DYNAMIC_PORT_MAX	0x7f

static DEFINE_SEQLOCK(local_port_range_lock);
static int local_port_range_min[2] = {0, 0};
static int local_port_range_max[2] = {1023, 1023};
static int local_port_range[2] = {DYNAMIC_PORT_MIN, DYNAMIC_PORT_MAX};
static struct ctl_table_header *phonet_table_hrd;

static void set_local_port_range(int range[2])
{
	write_seqlock(&local_port_range_lock);
	local_port_range[0] = range[0];
	local_port_range[1] = range[1];
	write_sequnlock(&local_port_range_lock);
}

void phonet_get_local_port_range(int *min, int *max)
{
	unsigned int seq;

	do {
		seq = read_seqbegin(&local_port_range_lock);
		if (min)
			*min = local_port_range[0];
		if (max)
			*max = local_port_range[1];
	} while (read_seqretry(&local_port_range_lock, seq));
}

static int proc_local_port_range(struct ctl_table *table, int write,
				void __user *buffer,
				size_t *lenp, loff_t *ppos)
{
	int ret;
	int range[2] = {local_port_range[0], local_port_range[1]};
	struct ctl_table tmp = {
		.data = &range,
		.maxlen = sizeof(range),
		.mode = table->mode,
		.extra1 = &local_port_range_min,
		.extra2 = &local_port_range_max,
	};

	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);

	if (write && ret == 0) {
		if (range[1] < range[0])
			ret = -EINVAL;
		else
			set_local_port_range(range);
	}

	return ret;
}

static struct ctl_table phonet_table[] = {
	{
		.procname	= "local_port_range",
		.data		= &local_port_range,
		.maxlen		= sizeof(local_port_range),
		.mode		= 0644,
		.proc_handler	= proc_local_port_range,
	},
	{ }
};

int __init phonet_sysctl_init(void)
{
	phonet_table_hrd = register_net_sysctl(&init_net, "net/phonet", phonet_table);
	return phonet_table_hrd == NULL ? -ENOMEM : 0;
}

void phonet_sysctl_exit(void)
{
	unregister_net_sysctl_table(phonet_table_hrd);
}
Commit	Line	Data
87ab4e20 RDC	1	/*
	2	* File: sysctl.c
	3	*
	4	* Phonet /proc/sys/net/phonet interface implementation
	5	*
	6	* Copyright (C) 2008 Nokia Corporation.
	7	*
31fdc555	8	* Author: Rémi Denis-Courmont
87ab4e20 RDC	9	*
	10	* This program is free software; you can redistribute it and/or
	11	* modify it under the terms of the GNU General Public License
	12	* version 2 as published by the Free Software Foundation.
	13	*
	14	* This program is distributed in the hope that it will be useful, but
	15	* WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	17	* General Public License for more details.
	18	*
	19	* You should have received a copy of the GNU General Public License
	20	* along with this program; if not, write to the Free Software
	21	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
	22	* 02110-1301 USA
	23	*/
	24
	25	#include <linux/seqlock.h>
	26	#include <linux/sysctl.h>
	27	#include <linux/errno.h>
	28	#include <linux/init.h>
	29
8e052e52 RDC	30	#include <net/sock.h>
	31	#include <linux/phonet.h>
	32	#include <net/phonet/phonet.h>
	33
87ab4e20 RDC	34	#define DYNAMIC_PORT_MIN 0x40
	35	#define DYNAMIC_PORT_MAX 0x7f
	36
	37	static DEFINE_SEQLOCK(local_port_range_lock);
	38	static int local_port_range_min[2] = {0, 0};
	39	static int local_port_range_max[2] = {1023, 1023};
	40	static int local_port_range[2] = {DYNAMIC_PORT_MIN, DYNAMIC_PORT_MAX};
	41	static struct ctl_table_header *phonet_table_hrd;
	42
	43	static void set_local_port_range(int range[2])
	44	{
	45	write_seqlock(&local_port_range_lock);
	46	local_port_range[0] = range[0];
	47	local_port_range[1] = range[1];
	48	write_sequnlock(&local_port_range_lock);
	49	}
	50
	51	void phonet_get_local_port_range(int min, int max)
	52	{
95c96174 ED	53	unsigned int seq;
95c96174 ED	54
87ab4e20 RDC	55	do {
	56	seq = read_seqbegin(&local_port_range_lock);
	57	if (min)
	58	*min = local_port_range[0];
	59	if (max)
	60	*max = local_port_range[1];
	61	} while (read_seqretry(&local_port_range_lock, seq));
	62	}
	63
fe2c6338	64	static int proc_local_port_range(struct ctl_table *table, int write,
87ab4e20 RDC	65	void __user *buffer,
	66	size_t lenp, loff_t ppos)
	67	{
	68	int ret;
	69	int range[2] = {local_port_range[0], local_port_range[1]};
fe2c6338	70	struct ctl_table tmp = {
87ab4e20 RDC	71	.data = &range,
	72	.maxlen = sizeof(range),
	73	.mode = table->mode,
	74	.extra1 = &local_port_range_min,
	75	.extra2 = &local_port_range_max,
	76	};
	77
8d65af78	78	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
87ab4e20 RDC	79
	80	if (write && ret == 0) {
	81	if (range[1] < range[0])
	82	ret = -EINVAL;
	83	else
	84	set_local_port_range(range);
	85	}
	86
	87	return ret;
	88	}
	89
	90	static struct ctl_table phonet_table[] = {
	91	{
87ab4e20 RDC	92	.procname = "local_port_range",
	93	.data = &local_port_range,
	94	.maxlen = sizeof(local_port_range),
	95	.mode = 0644,
6d9f239a	96	.proc_handler = proc_local_port_range,
87ab4e20	97	},
f8572d8f	98	{ }
87ab4e20 RDC	99	};
87ab4e20 RDC	100
87ab4e20 RDC	101	int __init phonet_sysctl_init(void)
87ab4e20 RDC	102	{
ec8f23ce	103	phonet_table_hrd = register_net_sysctl(&init_net, "net/phonet", phonet_table);
87ab4e20 RDC	104	return phonet_table_hrd == NULL ? -ENOMEM : 0;
	105	}
	106
	107	void phonet_sysctl_exit(void)
	108	{
5dd3df10	109	unregister_net_sysctl_table(phonet_table_hrd);
87ab4e20	110	}