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netfilter: xt_LED: add refcounts to LED target

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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: Adam Nielsen <a.nielsen@shikadi.net>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This commit is contained in:
Adam Nielsen 2010-04-09 16:51:40 +02:00 committed by Patrick McHardy
parent ed86308f61
commit b660d0485e
1 changed files with 63 additions and 6 deletions
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69
net/netfilter/xt_LED.c
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@ -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;
};
@ -53,7 +59,7 @@ led_tg(struct sk_buff *skb, const struct xt_target_param *par)
*/
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_OFF);
led_trigger_event(&ledinternal->netfilter_led_trigger, LED_FULL);
@ -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->netfilter_led_trigger.name = ledinfo->id;
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) {
@ -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);
}