From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?= Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- net/netfilter/xt_LED.c | 217 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 217 insertions(+) create mode 100644 net/netfilter/xt_LED.c (limited to 'net/netfilter/xt_LED.c') diff --git a/net/netfilter/xt_LED.c b/net/netfilter/xt_LED.c new file mode 100644 index 000000000..3ba31c194 --- /dev/null +++ b/net/netfilter/xt_LED.c @@ -0,0 +1,217 @@ +/* + * xt_LED.c - netfilter target to make LEDs blink upon packet matches + * + * Copyright (C) 2008 Adam Nielsen + * + * 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 +#include +#include +#include +#include +#include + +#include + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Adam Nielsen "); +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; +}; + +#define XT_LED_BLINK_DELAY 50 /* ms */ + +static unsigned int +led_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; + unsigned long led_delay = XT_LED_BLINK_DELAY; + + /* + * 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_blink_oneshot(&ledinternal->netfilter_led_trigger, + &led_delay, &led_delay, 1); + else + 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_err("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); -- cgit v1.2.3