/* * 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);}