Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b660d048 authored by Adam Nielsen's avatar Adam Nielsen Committed by Patrick McHardy
Browse files

netfilter: xt_LED: add refcounts to LED target 



Add reference counting to the netfilter LED target, to fix errors when
multiple rules point to the same target ("LED trigger already exists").

Signed-off-by: default avatarAdam Nielsen <a.nielsen@shikadi.net>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
parent ed86308f

net/netfilter/xt_LED.c

+63 −6
Original line number Diff line number Diff line
@@ -31,12 +31,18 @@ MODULE_LICENSE("GPL"); 
MODULE_AUTHOR("Adam Nielsen <a.nielsen@shikadi.net>");

MODULE_DESCRIPTION("Xtables: trigger LED devices on packet match");



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;

};
@@ -74,12 +80,23 @@ led_tg(struct sk_buff *skb, const struct xt_target_param *par) 


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;

	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;
@@ -91,11 +108,25 @@ static int led_tg_check(const struct xt_tgchk_param *par) 
		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)

		return -ENOMEM;

		goto exit_mutex_only;



	ledinternal->trigger_id = kstrdup(ledinfo->id, GFP_KERNEL);

	if (!ledinternal->trigger_id)

		goto exit_internal_alloc;



	ledinternal->netfilter_led_trigger.name = ledinfo->id;

	ledinternal->refcnt = 1;

	ledinternal->netfilter_led_trigger.name = ledinternal->trigger_id;



	err = led_trigger_register(&ledinternal->netfilter_led_trigger);

	if (err) {
@@ -108,13 +139,26 @@ static int led_tg_check(const struct xt_tgchk_param *par) 
	/* See if we need to set up a timer */

	if (ledinfo->delay > 0)

		setup_timer(&ledinternal->timer, led_timeout_callback,

			    (unsigned long)ledinfo);

			    (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;

}
@@ -123,10 +167,23 @@ 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);

}