diff options
Diffstat (limited to 'net/netfilter/xt_LED.c')
| -rw-r--r-- | net/netfilter/xt_LED.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/net/netfilter/xt_LED.c b/net/netfilter/xt_LED.c new file mode 100644 index 000000000000..8ff7843bb921 --- /dev/null +++ b/net/netfilter/xt_LED.c @@ -0,0 +1,161 @@ +/* + * 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. + * + */ + +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/netfilter/x_tables.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"); + +/* + * 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 led_trigger netfilter_led_trigger; + struct timer_list timer; +}; + +static unsigned int +led_tg(struct sk_buff *skb, const struct xt_target_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 *ledinfo = (struct xt_led_info *)data; + struct xt_led_info_internal *ledinternal = ledinfo->internal_data; + + led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF); +} + +static bool 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') { + printk(KERN_ERR KBUILD_MODNAME ": No 'id' parameter given.\n"); + return false; + } + + ledinternal = kzalloc(sizeof(struct xt_led_info_internal), GFP_KERNEL); + if (!ledinternal) { + printk(KERN_CRIT KBUILD_MODNAME ": out of memory\n"); + return false; + } + + ledinternal->netfilter_led_trigger.name = ledinfo->id; + + err = led_trigger_register(&ledinternal->netfilter_led_trigger); + if (err) { + printk(KERN_CRIT KBUILD_MODNAME + ": led_trigger_register() failed\n"); + if (err == -EEXIST) + printk(KERN_ERR KBUILD_MODNAME + ": 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)ledinfo); + + ledinfo->internal_data = ledinternal; + + return true; + +exit_alloc: + kfree(ledinternal); + + return false; +} + +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; + + if (ledinfo->delay > 0) + del_timer_sync(&ledinternal->timer); + + led_trigger_unregister(&ledinternal->netfilter_led_trigger); + kfree(ledinternal); +} + +static struct xt_target led_tg_reg __read_mostly = { + .name = "LED", + .revision = 0, + .family = NFPROTO_UNSPEC, + .target = led_tg, + .targetsize = XT_ALIGN(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); |