netfilter: x_tables: add LED trigger target
Kernel module providing implementation of LED netfilter target. Each
instance of the target appears as a led-trigger device, which can be
associated with one or more LEDs in /sys/class/leds/
Signed-off-by: Adam Nielsen <a.nielsen@shikadi.net>
Acked-by: Richard Purdie <rpurdie@linux.intel.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/net/netfilter/xt_LED.c b/net/netfilter/xt_LED.c
new file mode 100644
index 0000000..8ff7843
--- /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);