2 * xt_LED.c - netfilter target to make LEDs blink upon packet matches
4 * Copyright (C) 2008 Adam Nielsen <a.nielsen@shikadi.net>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; version 2 of the License.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
22 #include <linux/module.h>
23 #include <linux/skbuff.h>
24 #include <linux/netfilter/x_tables.h>
25 #include <linux/leds.h>
26 #include <linux/mutex.h>
28 #include <linux/netfilter/xt_LED.h>
30 MODULE_LICENSE("GPL");
31 MODULE_AUTHOR("Adam Nielsen <a.nielsen@shikadi.net>");
32 MODULE_DESCRIPTION("Xtables: trigger LED devices on packet match");
35 * This is declared in here (the kernel module) only, to avoid having these
36 * dependencies in userspace code. This is what xt_led_info.internal_data
39 struct xt_led_info_internal {
40 struct led_trigger netfilter_led_trigger;
41 struct timer_list timer;
45 led_tg(struct sk_buff *skb, const struct xt_target_param *par)
47 const struct xt_led_info *ledinfo = par->targinfo;
48 struct xt_led_info_internal *ledinternal = ledinfo->internal_data;
51 * If "always blink" is enabled, and there's still some time until the
52 * LED will switch off, briefly switch it off now.
54 if ((ledinfo->delay > 0) && ledinfo->always_blink &&
55 timer_pending(&ledinternal->timer))
56 led_trigger_event(&ledinternal->netfilter_led_trigger,LED_OFF);
58 led_trigger_event(&ledinternal->netfilter_led_trigger, LED_FULL);
60 /* If there's a positive delay, start/update the timer */
61 if (ledinfo->delay > 0) {
62 mod_timer(&ledinternal->timer,
63 jiffies + msecs_to_jiffies(ledinfo->delay));
65 /* Otherwise if there was no delay given, blink as fast as possible */
66 } else if (ledinfo->delay == 0) {
67 led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF);
70 /* else the delay is negative, which means switch on and stay on */
75 static void led_timeout_callback(unsigned long data)
77 struct xt_led_info *ledinfo = (struct xt_led_info *)data;
78 struct xt_led_info_internal *ledinternal = ledinfo->internal_data;
80 led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF);
83 static bool led_tg_check(const struct xt_tgchk_param *par)
85 struct xt_led_info *ledinfo = par->targinfo;
86 struct xt_led_info_internal *ledinternal;
89 if (ledinfo->id[0] == '\0') {
90 printk(KERN_ERR KBUILD_MODNAME ": No 'id' parameter given.\n");
94 ledinternal = kzalloc(sizeof(struct xt_led_info_internal), GFP_KERNEL);
96 printk(KERN_CRIT KBUILD_MODNAME ": out of memory\n");
100 ledinternal->netfilter_led_trigger.name = ledinfo->id;
102 err = led_trigger_register(&ledinternal->netfilter_led_trigger);
104 printk(KERN_CRIT KBUILD_MODNAME
105 ": led_trigger_register() failed\n");
107 printk(KERN_ERR KBUILD_MODNAME
108 ": Trigger name is already in use.\n");
112 /* See if we need to set up a timer */
113 if (ledinfo->delay > 0)
114 setup_timer(&ledinternal->timer, led_timeout_callback,
115 (unsigned long)ledinfo);
117 ledinfo->internal_data = ledinternal;
127 static void led_tg_destroy(const struct xt_tgdtor_param *par)
129 const struct xt_led_info *ledinfo = par->targinfo;
130 struct xt_led_info_internal *ledinternal = ledinfo->internal_data;
132 if (ledinfo->delay > 0)
133 del_timer_sync(&ledinternal->timer);
135 led_trigger_unregister(&ledinternal->netfilter_led_trigger);
139 static struct xt_target led_tg_reg __read_mostly = {
142 .family = NFPROTO_UNSPEC,
144 .targetsize = XT_ALIGN(sizeof(struct xt_led_info)),
145 .checkentry = led_tg_check,
146 .destroy = led_tg_destroy,
150 static int __init led_tg_init(void)
152 return xt_register_target(&led_tg_reg);
155 static void __exit led_tg_exit(void)
157 xt_unregister_target(&led_tg_reg);
160 module_init(led_tg_init);
161 module_exit(led_tg_exit);