// SPDX-License-Identifier: GPL-2.0-only/* * xt_LED.c - netfilter target to make LEDs blink upon packet matches * * Copyright (C) 2008 Adam Nielsen <a.nielsen@shikadi.net> */#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt#include <linux/module.h>#include <linux/skbuff.h>#include <linux/netfilter/x_tables.h>#include <linux/slab.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");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 intled_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; 	/*	 * 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,					  XT_LED_BLINK_DELAY, XT_LED_BLINK_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(struct timer_list *t){	struct xt_led_info_internal *ledinternal = timer_container_of(ledinternal,								      t,								      timer); 	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; 	/* Bail out if empty string or not a string at all. */	if (ledinfo->id[0] == '\0' ||	    !memchr(ledinfo->id, '\0', sizeof(ledinfo->id)))		return -EINVAL; 	mutex_lock(&xt_led_mutex); 	ledinternal = led_trigger_lookup(ledinfo->id);	if (ledinternal) {		ledinternal->refcnt++;		goto out;	} 	err = -ENOMEM;	ledinternal = kzalloc_obj(struct xt_led_info_internal);	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_info_ratelimited("Trigger name is already in use.\n");		goto exit_alloc;	} 	/* Since the letinternal timer can be shared between multiple targets,	 * always set it up, even if the current target does not need it	 */	timer_setup(&ledinternal->timer, led_timeout_callback, 0); 	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); 	timer_shutdown_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_IPV4,		.target		= led_tg,		.targetsize	= sizeof(struct xt_led_info),		.usersize	= offsetof(struct xt_led_info, internal_data),		.checkentry	= led_tg_check,		.destroy	= led_tg_destroy,		.me		= THIS_MODULE,	},#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)	{		.name		= "LED",		.revision	= 0,		.family		= NFPROTO_IPV6,		.target		= led_tg,		.targetsize	= sizeof(struct xt_led_info),		.usersize	= offsetof(struct xt_led_info, internal_data),		.checkentry	= led_tg_check,		.destroy	= led_tg_destroy,		.me		= THIS_MODULE,	},#endif}; static int __init led_tg_init(void){	return xt_register_targets(led_tg_reg, ARRAY_SIZE(led_tg_reg));} static void __exit led_tg_exit(void){	xt_unregister_targets(led_tg_reg, ARRAY_SIZE(led_tg_reg));} module_init(led_tg_init);module_exit(led_tg_exit);