/* * xt_LED.c - netfilter target to make LEDs blink upon packet matches * * Copyright (C) 2008 Adam Nielsen <a.nielsen@shikadi.net> * * 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. * * 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 Street, Fifth Floor, Boston, MA * 02110-1301 USA. * */#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt#include <linux/module.h>#include <linux/skbuff.h>#include <linux/netfilter/x_tables.h>#include <linux/slab.h>#include <linux/leds.h>#include <linux/mutex.h> #include <linux/netfilter/xt_LED.h> MODULE_LICENSE("GPL");MODULE_AUTHOR("Adam Nielsen <a.nielsen@shikadi.net>");MODULE_DESCRIPTION("Xtables: trigger LED devices on packet match");MODULE_ALIAS("ipt_LED");MODULE_ALIAS("ip6t_LED"); static LIST_HEAD(xt_led_triggers);static DEFINE_MUTEX(xt_led_mutex); /* * This is declared in here (the kernel module) only, to avoid having these * dependencies in userspace code.  This is what xt_led_info.internal_data * points to. */struct xt_led_info_internal {	struct list_head list;	int refcnt;	char *trigger_id;	struct led_trigger netfilter_led_trigger;	struct timer_list timer;}; static unsigned intled_tg(struct sk_buff *skb, const struct xt_action_param *par){	const struct xt_led_info *ledinfo = par->targinfo;	struct xt_led_info_internal *ledinternal = ledinfo->internal_data; 	/*	 * If "always blink" is enabled, and there's still some time until the	 * LED will switch off, briefly switch it off now.	 */	if ((ledinfo->delay > 0) && ledinfo->always_blink &&	    timer_pending(&ledinternal->timer))		led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF); 	led_trigger_event(&ledinternal->netfilter_led_trigger, LED_FULL); 	/* If there's a positive delay, start/update the timer */	if (ledinfo->delay > 0) {		mod_timer(&ledinternal->timer,			  jiffies + msecs_to_jiffies(ledinfo->delay)); 	/* Otherwise if there was no delay given, blink as fast as possible */	} else if (ledinfo->delay == 0) {		led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF);	} 	/* else the delay is negative, which means switch on and stay on */ 	return XT_CONTINUE;} static void led_timeout_callback(unsigned long data){	struct xt_led_info_internal *ledinternal = (struct xt_led_info_internal *)data; 	led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF);} static struct xt_led_info_internal *led_trigger_lookup(const char *name){	struct xt_led_info_internal *ledinternal; 	list_for_each_entry(ledinternal, &xt_led_triggers, list) {		if (!strcmp(name, ledinternal->netfilter_led_trigger.name)) {			return ledinternal;		}	}	return NULL;} static int led_tg_check(const struct xt_tgchk_param *par){	struct xt_led_info *ledinfo = par->targinfo;	struct xt_led_info_internal *ledinternal;	int err; 	if (ledinfo->id[0] == '\0') {		pr_info("No 'id' parameter given.\n");		return -EINVAL;	} 	mutex_lock(&xt_led_mutex); 	ledinternal = led_trigger_lookup(ledinfo->id);	if (ledinternal) {		ledinternal->refcnt++;		goto out;	} 	err = -ENOMEM;	ledinternal = kzalloc(sizeof(struct xt_led_info_internal), GFP_KERNEL);	if (!ledinternal)		goto exit_mutex_only; 	ledinternal->trigger_id = kstrdup(ledinfo->id, GFP_KERNEL);	if (!ledinternal->trigger_id)		goto exit_internal_alloc; 	ledinternal->refcnt = 1;	ledinternal->netfilter_led_trigger.name = ledinternal->trigger_id; 	err = led_trigger_register(&ledinternal->netfilter_led_trigger);	if (err) {		pr_warning("led_trigger_register() failed\n");		if (err == -EEXIST)			pr_warning("Trigger name is already in use.\n");		goto exit_alloc;	} 	/* See if we need to set up a timer */	if (ledinfo->delay > 0)		setup_timer(&ledinternal->timer, led_timeout_callback,			    (unsigned long)ledinternal); 	list_add_tail(&ledinternal->list, &xt_led_triggers); out:	mutex_unlock(&xt_led_mutex); 	ledinfo->internal_data = ledinternal; 	return 0; exit_alloc:	kfree(ledinternal->trigger_id); exit_internal_alloc:	kfree(ledinternal); exit_mutex_only:	mutex_unlock(&xt_led_mutex); 	return err;} static void led_tg_destroy(const struct xt_tgdtor_param *par){	const struct xt_led_info *ledinfo = par->targinfo;	struct xt_led_info_internal *ledinternal = ledinfo->internal_data; 	mutex_lock(&xt_led_mutex); 	if (--ledinternal->refcnt) {		mutex_unlock(&xt_led_mutex);		return;	} 	list_del(&ledinternal->list); 	if (ledinfo->delay > 0)		del_timer_sync(&ledinternal->timer); 	led_trigger_unregister(&ledinternal->netfilter_led_trigger); 	mutex_unlock(&xt_led_mutex); 	kfree(ledinternal->trigger_id);	kfree(ledinternal);} static struct xt_target led_tg_reg __read_mostly = {	.name		= "LED",	.revision	= 0,	.family		= NFPROTO_UNSPEC,	.target		= led_tg,	.targetsize	= sizeof(struct xt_led_info),	.checkentry	= led_tg_check,	.destroy	= led_tg_destroy,	.me		= THIS_MODULE,}; static int __init led_tg_init(void){	return xt_register_target(&led_tg_reg);} static void __exit led_tg_exit(void){	xt_unregister_target(&led_tg_reg);} module_init(led_tg_init);module_exit(led_tg_exit);