[linux-block.git] / net / netfilter / xt_IDLETIMER.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * linux/net/netfilter/xt_IDLETIMER.c
 *
 * Netfilter module to trigger a timer when packet matches.
 * After timer expires a kevent will be sent.
 *
 * Copyright (C) 2004, 2010 Nokia Corporation
 * Written by Timo Teras <ext-timo.teras@nokia.com>
 *
 * Converted to x_tables and reworked for upstream inclusion
 * by Luciano Coelho <luciano.coelho@nokia.com>
 *
 * Contact: Luciano Coelho <luciano.coelho@nokia.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/timer.h>
#include <linux/alarmtimer.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/netfilter.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_IDLETIMER.h>
#include <linux/kdev_t.h>
#include <linux/kobject.h>
#include <linux/workqueue.h>
#include <linux/sysfs.h>

struct idletimer_tg {
	struct list_head entry;
	struct alarm alarm;
	struct timer_list timer;
	struct work_struct work;

	struct kobject *kobj;
	struct device_attribute attr;

	unsigned int refcnt;
	u8 timer_type;
};

static LIST_HEAD(idletimer_tg_list);
static DEFINE_MUTEX(list_mutex);

static struct kobject *idletimer_tg_kobj;

static
struct idletimer_tg *__idletimer_tg_find_by_label(const char *label)
{
	struct idletimer_tg *entry;

	list_for_each_entry(entry, &idletimer_tg_list, entry) {
		if (!strcmp(label, entry->attr.attr.name))
			return entry;
	}

	return NULL;
}

static ssize_t idletimer_tg_show(struct device *dev,
				 struct device_attribute *attr, char *buf)
{
	struct idletimer_tg *timer;
	unsigned long expires = 0;
	struct timespec64 ktimespec = {};
	long time_diff = 0;

	mutex_lock(&list_mutex);

	timer =	__idletimer_tg_find_by_label(attr->attr.name);
	if (timer) {
		if (timer->timer_type & XT_IDLETIMER_ALARM) {
			ktime_t expires_alarm = alarm_expires_remaining(&timer->alarm);
			ktimespec = ktime_to_timespec64(expires_alarm);
			time_diff = ktimespec.tv_sec;
		} else {
			expires = timer->timer.expires;
			time_diff = jiffies_to_msecs(expires - jiffies) / 1000;
		}
	}

	mutex_unlock(&list_mutex);

	if (time_after(expires, jiffies) || ktimespec.tv_sec > 0)
		return sysfs_emit(buf, "%ld\n", time_diff);

	return sysfs_emit(buf, "0\n");
}

static void idletimer_tg_work(struct work_struct *work)
{
	struct idletimer_tg *timer = container_of(work, struct idletimer_tg,
						  work);

	sysfs_notify(idletimer_tg_kobj, NULL, timer->attr.attr.name);
}

static void idletimer_tg_expired(struct timer_list *t)
{
	struct idletimer_tg *timer = from_timer(timer, t, timer);

	pr_debug("timer %s expired\n", timer->attr.attr.name);

	schedule_work(&timer->work);
}

static enum alarmtimer_restart idletimer_tg_alarmproc(struct alarm *alarm,
							  ktime_t now)
{
	struct idletimer_tg *timer = alarm->data;

	pr_debug("alarm %s expired\n", timer->attr.attr.name);
	schedule_work(&timer->work);
	return ALARMTIMER_NORESTART;
}

static int idletimer_check_sysfs_name(const char *name, unsigned int size)
{
	int ret;

	ret = xt_check_proc_name(name, size);
	if (ret < 0)
		return ret;

	if (!strcmp(name, "power") ||
	    !strcmp(name, "subsystem") ||
	    !strcmp(name, "uevent"))
		return -EINVAL;

	return 0;
}

static int idletimer_tg_create(struct idletimer_tg_info *info)
{
	int ret;

	info->timer = kzalloc(sizeof(*info->timer), GFP_KERNEL);
	if (!info->timer) {
		ret = -ENOMEM;
		goto out;
	}

	ret = idletimer_check_sysfs_name(info->label, sizeof(info->label));
	if (ret < 0)
		goto out_free_timer;

	sysfs_attr_init(&info->timer->attr.attr);
	info->timer->attr.attr.name = kstrdup(info->label, GFP_KERNEL);
	if (!info->timer->attr.attr.name) {
		ret = -ENOMEM;
		goto out_free_timer;
	}
	info->timer->attr.attr.mode = 0444;
	info->timer->attr.show = idletimer_tg_show;

	ret = sysfs_create_file(idletimer_tg_kobj, &info->timer->attr.attr);
	if (ret < 0) {
		pr_debug("couldn't add file to sysfs");
		goto out_free_attr;
	}

	list_add(&info->timer->entry, &idletimer_tg_list);

	timer_setup(&info->timer->timer, idletimer_tg_expired, 0);
	info->timer->refcnt = 1;

	INIT_WORK(&info->timer->work, idletimer_tg_work);

	mod_timer(&info->timer->timer,
		  msecs_to_jiffies(info->timeout * 1000) + jiffies);

	return 0;

out_free_attr:
	kfree(info->timer->attr.attr.name);
out_free_timer:
	kfree(info->timer);
out:
	return ret;
}

static int idletimer_tg_create_v1(struct idletimer_tg_info_v1 *info)
{
	int ret;

	info->timer = kmalloc(sizeof(*info->timer), GFP_KERNEL);
	if (!info->timer) {
		ret = -ENOMEM;
		goto out;
	}

	ret = idletimer_check_sysfs_name(info->label, sizeof(info->label));
	if (ret < 0)
		goto out_free_timer;

	sysfs_attr_init(&info->timer->attr.attr);
	info->timer->attr.attr.name = kstrdup(info->label, GFP_KERNEL);
	if (!info->timer->attr.attr.name) {
		ret = -ENOMEM;
		goto out_free_timer;
	}
	info->timer->attr.attr.mode = 0444;
	info->timer->attr.show = idletimer_tg_show;

	ret = sysfs_create_file(idletimer_tg_kobj, &info->timer->attr.attr);
	if (ret < 0) {
		pr_debug("couldn't add file to sysfs");
		goto out_free_attr;
	}

	/*  notify userspace  */
	kobject_uevent(idletimer_tg_kobj,KOBJ_ADD);

	list_add(&info->timer->entry, &idletimer_tg_list);
	pr_debug("timer type value is %u", info->timer_type);
	info->timer->timer_type = info->timer_type;
	info->timer->refcnt = 1;

	INIT_WORK(&info->timer->work, idletimer_tg_work);

	if (info->timer->timer_type & XT_IDLETIMER_ALARM) {
		ktime_t tout;
		alarm_init(&info->timer->alarm, ALARM_BOOTTIME,
			   idletimer_tg_alarmproc);
		info->timer->alarm.data = info->timer;
		tout = ktime_set(info->timeout, 0);
		alarm_start_relative(&info->timer->alarm, tout);
	} else {
		timer_setup(&info->timer->timer, idletimer_tg_expired, 0);
		mod_timer(&info->timer->timer,
				msecs_to_jiffies(info->timeout * 1000) + jiffies);
	}

	return 0;

out_free_attr:
	kfree(info->timer->attr.attr.name);
out_free_timer:
	kfree(info->timer);
out:
	return ret;
}

/*
 * The actual xt_tables plugin.
 */
static unsigned int idletimer_tg_target(struct sk_buff *skb,
					 const struct xt_action_param *par)
{
	const struct idletimer_tg_info *info = par->targinfo;

	pr_debug("resetting timer %s, timeout period %u\n",
		 info->label, info->timeout);

	mod_timer(&info->timer->timer,
		  msecs_to_jiffies(info->timeout * 1000) + jiffies);

	return XT_CONTINUE;
}

/*
 * The actual xt_tables plugin.
 */
static unsigned int idletimer_tg_target_v1(struct sk_buff *skb,
					 const struct xt_action_param *par)
{
	const struct idletimer_tg_info_v1 *info = par->targinfo;

	pr_debug("resetting timer %s, timeout period %u\n",
		 info->label, info->timeout);

	if (info->timer->timer_type & XT_IDLETIMER_ALARM) {
		ktime_t tout = ktime_set(info->timeout, 0);
		alarm_start_relative(&info->timer->alarm, tout);
	} else {
		mod_timer(&info->timer->timer,
				msecs_to_jiffies(info->timeout * 1000) + jiffies);
	}

	return XT_CONTINUE;
}

static int idletimer_tg_helper(struct idletimer_tg_info *info)
{
	if (info->timeout == 0) {
		pr_debug("timeout value is zero\n");
		return -EINVAL;
	}
	if (info->timeout >= INT_MAX / 1000) {
		pr_debug("timeout value is too big\n");
		return -EINVAL;
	}
	if (info->label[0] == '\0' ||
	    strnlen(info->label,
		    MAX_IDLETIMER_LABEL_SIZE) == MAX_IDLETIMER_LABEL_SIZE) {
		pr_debug("label is empty or not nul-terminated\n");
		return -EINVAL;
	}
	return 0;
}


static int idletimer_tg_checkentry(const struct xt_tgchk_param *par)
{
	struct idletimer_tg_info *info = par->targinfo;
	int ret;

	pr_debug("checkentry targinfo%s\n", info->label);

	ret = idletimer_tg_helper(info);
	if(ret < 0)
	{
		pr_debug("checkentry helper return invalid\n");
		return -EINVAL;
	}
	mutex_lock(&list_mutex);

	info->timer = __idletimer_tg_find_by_label(info->label);
	if (info->timer) {
		info->timer->refcnt++;
		mod_timer(&info->timer->timer,
			  msecs_to_jiffies(info->timeout * 1000) + jiffies);

		pr_debug("increased refcnt of timer %s to %u\n",
			 info->label, info->timer->refcnt);
	} else {
		ret = idletimer_tg_create(info);
		if (ret < 0) {
			pr_debug("failed to create timer\n");
			mutex_unlock(&list_mutex);
			return ret;
		}
	}

	mutex_unlock(&list_mutex);
	return 0;
}

static int idletimer_tg_checkentry_v1(const struct xt_tgchk_param *par)
{
	struct idletimer_tg_info_v1 *info = par->targinfo;
	int ret;

	pr_debug("checkentry targinfo%s\n", info->label);

	if (info->send_nl_msg)
		return -EOPNOTSUPP;

	ret = idletimer_tg_helper((struct idletimer_tg_info *)info);
	if(ret < 0)
	{
		pr_debug("checkentry helper return invalid\n");
		return -EINVAL;
	}

	if (info->timer_type > XT_IDLETIMER_ALARM) {
		pr_debug("invalid value for timer type\n");
		return -EINVAL;
	}

	mutex_lock(&list_mutex);

	info->timer = __idletimer_tg_find_by_label(info->label);
	if (info->timer) {
		if (info->timer->timer_type != info->timer_type) {
			pr_debug("Adding/Replacing rule with same label and different timer type is not allowed\n");
			mutex_unlock(&list_mutex);
			return -EINVAL;
		}

		info->timer->refcnt++;
		if (info->timer_type & XT_IDLETIMER_ALARM) {
			/* calculate remaining expiry time */
			ktime_t tout = alarm_expires_remaining(&info->timer->alarm);
			struct timespec64 ktimespec = ktime_to_timespec64(tout);

			if (ktimespec.tv_sec > 0) {
				pr_debug("time_expiry_remaining %lld\n",
					 ktimespec.tv_sec);
				alarm_start_relative(&info->timer->alarm, tout);
			}
		} else {
				mod_timer(&info->timer->timer,
					msecs_to_jiffies(info->timeout * 1000) + jiffies);
		}
		pr_debug("increased refcnt of timer %s to %u\n",
			 info->label, info->timer->refcnt);
	} else {
		ret = idletimer_tg_create_v1(info);
		if (ret < 0) {
			pr_debug("failed to create timer\n");
			mutex_unlock(&list_mutex);
			return ret;
		}
	}

	mutex_unlock(&list_mutex);
	return 0;
}

static void idletimer_tg_destroy(const struct xt_tgdtor_param *par)
{
	const struct idletimer_tg_info *info = par->targinfo;

	pr_debug("destroy targinfo %s\n", info->label);

	mutex_lock(&list_mutex);

	if (--info->timer->refcnt == 0) {
		pr_debug("deleting timer %s\n", info->label);

		list_del(&info->timer->entry);
		timer_shutdown_sync(&info->timer->timer);
		cancel_work_sync(&info->timer->work);
		sysfs_remove_file(idletimer_tg_kobj, &info->timer->attr.attr);
		kfree(info->timer->attr.attr.name);
		kfree(info->timer);
	} else {
		pr_debug("decreased refcnt of timer %s to %u\n",
			 info->label, info->timer->refcnt);
	}

	mutex_unlock(&list_mutex);
}

static void idletimer_tg_destroy_v1(const struct xt_tgdtor_param *par)
{
	const struct idletimer_tg_info_v1 *info = par->targinfo;

	pr_debug("destroy targinfo %s\n", info->label);

	mutex_lock(&list_mutex);

	if (--info->timer->refcnt == 0) {
		pr_debug("deleting timer %s\n", info->label);

		list_del(&info->timer->entry);
		if (info->timer->timer_type & XT_IDLETIMER_ALARM) {
			alarm_cancel(&info->timer->alarm);
		} else {
			timer_shutdown_sync(&info->timer->timer);
		}
		cancel_work_sync(&info->timer->work);
		sysfs_remove_file(idletimer_tg_kobj, &info->timer->attr.attr);
		kfree(info->timer->attr.attr.name);
		kfree(info->timer);
	} else {
		pr_debug("decreased refcnt of timer %s to %u\n",
			 info->label, info->timer->refcnt);
	}

	mutex_unlock(&list_mutex);
}


static struct xt_target idletimer_tg[] __read_mostly = {
	{
	.name		= "IDLETIMER",
	.family		= NFPROTO_UNSPEC,
	.target		= idletimer_tg_target,
	.targetsize     = sizeof(struct idletimer_tg_info),
	.usersize	= offsetof(struct idletimer_tg_info, timer),
	.checkentry	= idletimer_tg_checkentry,
	.destroy        = idletimer_tg_destroy,
	.me		= THIS_MODULE,
	},
	{
	.name		= "IDLETIMER",
	.family		= NFPROTO_UNSPEC,
	.revision	= 1,
	.target		= idletimer_tg_target_v1,
	.targetsize     = sizeof(struct idletimer_tg_info_v1),
	.usersize	= offsetof(struct idletimer_tg_info_v1, timer),
	.checkentry	= idletimer_tg_checkentry_v1,
	.destroy        = idletimer_tg_destroy_v1,
	.me		= THIS_MODULE,
	},


};

static struct class *idletimer_tg_class;

static struct device *idletimer_tg_device;

static int __init idletimer_tg_init(void)
{
	int err;

	idletimer_tg_class = class_create("xt_idletimer");
	err = PTR_ERR(idletimer_tg_class);
	if (IS_ERR(idletimer_tg_class)) {
		pr_debug("couldn't register device class\n");
		goto out;
	}

	idletimer_tg_device = device_create(idletimer_tg_class, NULL,
					    MKDEV(0, 0), NULL, "timers");
	err = PTR_ERR(idletimer_tg_device);
	if (IS_ERR(idletimer_tg_device)) {
		pr_debug("couldn't register system device\n");
		goto out_class;
	}

	idletimer_tg_kobj = &idletimer_tg_device->kobj;

	err = xt_register_targets(idletimer_tg, ARRAY_SIZE(idletimer_tg));

	if (err < 0) {
		pr_debug("couldn't register xt target\n");
		goto out_dev;
	}

	return 0;
out_dev:
	device_destroy(idletimer_tg_class, MKDEV(0, 0));
out_class:
	class_destroy(idletimer_tg_class);
out:
	return err;
}

static void __exit idletimer_tg_exit(void)
{
	xt_unregister_targets(idletimer_tg, ARRAY_SIZE(idletimer_tg));

	device_destroy(idletimer_tg_class, MKDEV(0, 0));
	class_destroy(idletimer_tg_class);
}

module_init(idletimer_tg_init);
module_exit(idletimer_tg_exit);

MODULE_AUTHOR("Timo Teras <ext-timo.teras@nokia.com>");
MODULE_AUTHOR("Luciano Coelho <luciano.coelho@nokia.com>");
MODULE_DESCRIPTION("Xtables: idle time monitor");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("ipt_IDLETIMER");
MODULE_ALIAS("ip6t_IDLETIMER");
Commit	Line	Data
2b27bdcc	1	// SPDX-License-Identifier: GPL-2.0-only
0902b469 LC	2	/*
	3	* linux/net/netfilter/xt_IDLETIMER.c
	4	*
	5	* Netfilter module to trigger a timer when packet matches.
	6	* After timer expires a kevent will be sent.
	7	*
	8	* Copyright (C) 2004, 2010 Nokia Corporation
	9	* Written by Timo Teras <ext-timo.teras@nokia.com>
	10	*
	11	* Converted to x_tables and reworked for upstream inclusion
	12	* by Luciano Coelho <luciano.coelho@nokia.com>
	13	*
	14	* Contact: Luciano Coelho <luciano.coelho@nokia.com>
0902b469 LC	15	*/
	16
	17	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	18
	19	#include <linux/module.h>
	20	#include <linux/timer.h>
68983a35	21	#include <linux/alarmtimer.h>
0902b469 LC	22	#include <linux/list.h>
	23	#include <linux/mutex.h>
	24	#include <linux/netfilter.h>
	25	#include <linux/netfilter/x_tables.h>
	26	#include <linux/netfilter/xt_IDLETIMER.h>
600069da	27	#include <linux/kdev_t.h>
0902b469 LC	28	#include <linux/kobject.h>
	29	#include <linux/workqueue.h>
	30	#include <linux/sysfs.h>
	31
0902b469 LC	32	struct idletimer_tg {
0902b469 LC	33	struct list_head entry;
68983a35	34	struct alarm alarm;
0902b469 LC	35	struct timer_list timer;
	36	struct work_struct work;
	37
	38	struct kobject *kobj;
20fdaf6e	39	struct device_attribute attr;
0902b469 LC	40
0902b469 LC	41	unsigned int refcnt;
68983a35	42	u8 timer_type;
0902b469 LC	43	};
	44
	45	static LIST_HEAD(idletimer_tg_list);
	46	static DEFINE_MUTEX(list_mutex);
	47
	48	static struct kobject *idletimer_tg_kobj;
	49
	50	static
	51	struct idletimer_tg __idletimer_tg_find_by_label(const char label)
	52	{
	53	struct idletimer_tg *entry;
	54
0902b469 LC	55	list_for_each_entry(entry, &idletimer_tg_list, entry) {
	56	if (!strcmp(label, entry->attr.attr.name))
	57	return entry;
	58	}
	59
	60	return NULL;
	61	}
	62
20fdaf6e ST	63	static ssize_t idletimer_tg_show(struct device *dev,
20fdaf6e ST	64	struct device_attribute attr, char buf)
0902b469 LC	65	{
	66	struct idletimer_tg *timer;
	67	unsigned long expires = 0;
68983a35 MB	68	struct timespec64 ktimespec = {};
68983a35 MB	69	long time_diff = 0;
0902b469 LC	70
	71	mutex_lock(&list_mutex);
	72
20fdaf6e	73	timer = __idletimer_tg_find_by_label(attr->attr.name);
68983a35 MB	74	if (timer) {
	75	if (timer->timer_type & XT_IDLETIMER_ALARM) {
	76	ktime_t expires_alarm = alarm_expires_remaining(&timer->alarm);
	77	ktimespec = ktime_to_timespec64(expires_alarm);
	78	time_diff = ktimespec.tv_sec;
	79	} else {
f628c27d DC	80	expires = timer->timer.expires;
f628c27d DC	81	time_diff = jiffies_to_msecs(expires - jiffies) / 1000;
68983a35 MB	82	}
68983a35 MB	83	}
0902b469 LC	84
	85	mutex_unlock(&list_mutex);
	86
68983a35	87	if (time_after(expires, jiffies) \|\| ktimespec.tv_sec > 0)
c08d3286	88	return sysfs_emit(buf, "%ld\n", time_diff);
0902b469	89
c08d3286	90	return sysfs_emit(buf, "0\n");
0902b469 LC	91	}
	92
	93	static void idletimer_tg_work(struct work_struct *work)
	94	{
	95	struct idletimer_tg *timer = container_of(work, struct idletimer_tg,
	96	work);
	97
	98	sysfs_notify(idletimer_tg_kobj, NULL, timer->attr.attr.name);
	99	}
	100
e99e88a9	101	static void idletimer_tg_expired(struct timer_list *t)
0902b469	102	{
e99e88a9	103	struct idletimer_tg *timer = from_timer(timer, t, timer);
0902b469 LC	104
	105	pr_debug("timer %s expired\n", timer->attr.attr.name);
	106
	107	schedule_work(&timer->work);
	108	}
	109
68983a35 MB	110	static enum alarmtimer_restart idletimer_tg_alarmproc(struct alarm *alarm,
	111	ktime_t now)
	112	{
	113	struct idletimer_tg *timer = alarm->data;
	114
	115	pr_debug("alarm %s expired\n", timer->attr.attr.name);
	116	schedule_work(&timer->work);
	117	return ALARMTIMER_NORESTART;
	118	}
	119
54451f60 TY	120	static int idletimer_check_sysfs_name(const char *name, unsigned int size)
	121	{
	122	int ret;
	123
	124	ret = xt_check_proc_name(name, size);
	125	if (ret < 0)
	126	return ret;
	127
	128	if (!strcmp(name, "power") \|\|
	129	!strcmp(name, "subsystem") \|\|
	130	!strcmp(name, "uevent"))
	131	return -EINVAL;
	132
	133	return 0;
	134	}
	135
0902b469 LC	136	static int idletimer_tg_create(struct idletimer_tg_info *info)
	137	{
	138	int ret;
	139
902c0b18	140	info->timer = kzalloc(sizeof(*info->timer), GFP_KERNEL);
0902b469	141	if (!info->timer) {
0902b469 LC	142	ret = -ENOMEM;
	143	goto out;
	144	}
	145
54451f60 TY	146	ret = idletimer_check_sysfs_name(info->label, sizeof(info->label));
	147	if (ret < 0)
	148	goto out_free_timer;
	149
484836ec	150	sysfs_attr_init(&info->timer->attr.attr);
0902b469 LC	151	info->timer->attr.attr.name = kstrdup(info->label, GFP_KERNEL);
0902b469 LC	152	if (!info->timer->attr.attr.name) {
0902b469 LC	153	ret = -ENOMEM;
	154	goto out_free_timer;
	155	}
d6444062	156	info->timer->attr.attr.mode = 0444;
0902b469 LC	157	info->timer->attr.show = idletimer_tg_show;
	158
	159	ret = sysfs_create_file(idletimer_tg_kobj, &info->timer->attr.attr);
	160	if (ret < 0) {
	161	pr_debug("couldn't add file to sysfs");
	162	goto out_free_attr;
	163	}
	164
	165	list_add(&info->timer->entry, &idletimer_tg_list);
	166
e99e88a9	167	timer_setup(&info->timer->timer, idletimer_tg_expired, 0);
0902b469 LC	168	info->timer->refcnt = 1;
0902b469 LC	169
cfc2c740 ED	170	INIT_WORK(&info->timer->work, idletimer_tg_work);
cfc2c740 ED	171
0902b469 LC	172	mod_timer(&info->timer->timer,
	173	msecs_to_jiffies(info->timeout * 1000) + jiffies);
	174
0902b469 LC	175	return 0;
	176
	177	out_free_attr:
	178	kfree(info->timer->attr.attr.name);
	179	out_free_timer:
	180	kfree(info->timer);
	181	out:
	182	return ret;
	183	}
	184
68983a35 MB	185	static int idletimer_tg_create_v1(struct idletimer_tg_info_v1 *info)
	186	{
	187	int ret;
	188
	189	info->timer = kmalloc(sizeof(*info->timer), GFP_KERNEL);
	190	if (!info->timer) {
	191	ret = -ENOMEM;
	192	goto out;
	193	}
	194
	195	ret = idletimer_check_sysfs_name(info->label, sizeof(info->label));
	196	if (ret < 0)
	197	goto out_free_timer;
	198
	199	sysfs_attr_init(&info->timer->attr.attr);
	200	info->timer->attr.attr.name = kstrdup(info->label, GFP_KERNEL);
	201	if (!info->timer->attr.attr.name) {
	202	ret = -ENOMEM;
	203	goto out_free_timer;
	204	}
	205	info->timer->attr.attr.mode = 0444;
	206	info->timer->attr.show = idletimer_tg_show;
	207
	208	ret = sysfs_create_file(idletimer_tg_kobj, &info->timer->attr.attr);
	209	if (ret < 0) {
	210	pr_debug("couldn't add file to sysfs");
	211	goto out_free_attr;
	212	}
	213
	214	/* notify userspace */
	215	kobject_uevent(idletimer_tg_kobj,KOBJ_ADD);
	216
	217	list_add(&info->timer->entry, &idletimer_tg_list);
f628c27d	218	pr_debug("timer type value is %u", info->timer_type);
68983a35 MB	219	info->timer->timer_type = info->timer_type;
	220	info->timer->refcnt = 1;
	221
	222	INIT_WORK(&info->timer->work, idletimer_tg_work);
	223
	224	if (info->timer->timer_type & XT_IDLETIMER_ALARM) {
	225	ktime_t tout;
	226	alarm_init(&info->timer->alarm, ALARM_BOOTTIME,
	227	idletimer_tg_alarmproc);
	228	info->timer->alarm.data = info->timer;
	229	tout = ktime_set(info->timeout, 0);
	230	alarm_start_relative(&info->timer->alarm, tout);
	231	} else {
	232	timer_setup(&info->timer->timer, idletimer_tg_expired, 0);
	233	mod_timer(&info->timer->timer,
	234	msecs_to_jiffies(info->timeout * 1000) + jiffies);
	235	}
	236
	237	return 0;
	238
	239	out_free_attr:
	240	kfree(info->timer->attr.attr.name);
	241	out_free_timer:
	242	kfree(info->timer);
	243	out:
	244	return ret;
	245	}
	246
0902b469 LC	247	/*
	248	* The actual xt_tables plugin.
	249	*/
	250	static unsigned int idletimer_tg_target(struct sk_buff *skb,
	251	const struct xt_action_param *par)
	252	{
	253	const struct idletimer_tg_info *info = par->targinfo;
	254
	255	pr_debug("resetting timer %s, timeout period %u\n",
	256	info->label, info->timeout);
	257
0902b469 LC	258	mod_timer(&info->timer->timer,
	259	msecs_to_jiffies(info->timeout * 1000) + jiffies);
	260
	261	return XT_CONTINUE;
	262	}
	263
68983a35 MB	264	/*
	265	* The actual xt_tables plugin.
	266	*/
	267	static unsigned int idletimer_tg_target_v1(struct sk_buff *skb,
	268	const struct xt_action_param *par)
0902b469	269	{
68983a35	270	const struct idletimer_tg_info_v1 *info = par->targinfo;
0902b469	271
68983a35 MB	272	pr_debug("resetting timer %s, timeout period %u\n",
	273	info->label, info->timeout);
	274
	275	if (info->timer->timer_type & XT_IDLETIMER_ALARM) {
	276	ktime_t tout = ktime_set(info->timeout, 0);
	277	alarm_start_relative(&info->timer->alarm, tout);
	278	} else {
	279	mod_timer(&info->timer->timer,
	280	msecs_to_jiffies(info->timeout * 1000) + jiffies);
	281	}
0902b469	282
68983a35 MB	283	return XT_CONTINUE;
	284	}
	285
	286	static int idletimer_tg_helper(struct idletimer_tg_info *info)
	287	{
0902b469 LC	288	if (info->timeout == 0) {
	289	pr_debug("timeout value is zero\n");
	290	return -EINVAL;
	291	}
cfc2c740 ED	292	if (info->timeout >= INT_MAX / 1000) {
	293	pr_debug("timeout value is too big\n");
	294	return -EINVAL;
	295	}
0902b469 LC	296	if (info->label[0] == '\0' \|\|
	297	strnlen(info->label,
	298	MAX_IDLETIMER_LABEL_SIZE) == MAX_IDLETIMER_LABEL_SIZE) {
	299	pr_debug("label is empty or not nul-terminated\n");
	300	return -EINVAL;
	301	}
68983a35 MB	302	return 0;
68983a35 MB	303	}
0902b469	304
68983a35 MB	305
	306	static int idletimer_tg_checkentry(const struct xt_tgchk_param *par)
	307	{
	308	struct idletimer_tg_info *info = par->targinfo;
	309	int ret;
	310
	311	pr_debug("checkentry targinfo%s\n", info->label);
	312
	313	ret = idletimer_tg_helper(info);
	314	if(ret < 0)
	315	{
	316	pr_debug("checkentry helper return invalid\n");
	317	return -EINVAL;
	318	}
0902b469 LC	319	mutex_lock(&list_mutex);
	320
	321	info->timer = __idletimer_tg_find_by_label(info->label);
	322	if (info->timer) {
	323	info->timer->refcnt++;
	324	mod_timer(&info->timer->timer,
	325	msecs_to_jiffies(info->timeout * 1000) + jiffies);
	326
	327	pr_debug("increased refcnt of timer %s to %u\n",
	328	info->label, info->timer->refcnt);
	329	} else {
	330	ret = idletimer_tg_create(info);
	331	if (ret < 0) {
	332	pr_debug("failed to create timer\n");
	333	mutex_unlock(&list_mutex);
	334	return ret;
	335	}
	336	}
	337
	338	mutex_unlock(&list_mutex);
	339	return 0;
	340	}
	341
68983a35 MB	342	static int idletimer_tg_checkentry_v1(const struct xt_tgchk_param *par)
	343	{
	344	struct idletimer_tg_info_v1 *info = par->targinfo;
	345	int ret;
	346
	347	pr_debug("checkentry targinfo%s\n", info->label);
	348
bc9fe614 MŻ	349	if (info->send_nl_msg)
	350	return -EOPNOTSUPP;
	351
68983a35 MB	352	ret = idletimer_tg_helper((struct idletimer_tg_info *)info);
	353	if(ret < 0)
	354	{
	355	pr_debug("checkentry helper return invalid\n");
	356	return -EINVAL;
	357	}
	358
	359	if (info->timer_type > XT_IDLETIMER_ALARM) {
	360	pr_debug("invalid value for timer type\n");
	361	return -EINVAL;
	362	}
	363
	364	mutex_lock(&list_mutex);
	365
	366	info->timer = __idletimer_tg_find_by_label(info->label);
	367	if (info->timer) {
	368	if (info->timer->timer_type != info->timer_type) {
	369	pr_debug("Adding/Replacing rule with same label and different timer type is not allowed\n");
	370	mutex_unlock(&list_mutex);
	371	return -EINVAL;
	372	}
	373
	374	info->timer->refcnt++;
	375	if (info->timer_type & XT_IDLETIMER_ALARM) {
	376	/* calculate remaining expiry time */
	377	ktime_t tout = alarm_expires_remaining(&info->timer->alarm);
	378	struct timespec64 ktimespec = ktime_to_timespec64(tout);
	379
	380	if (ktimespec.tv_sec > 0) {
	381	pr_debug("time_expiry_remaining %lld\n",
	382	ktimespec.tv_sec);
	383	alarm_start_relative(&info->timer->alarm, tout);
	384	}
	385	} else {
	386	mod_timer(&info->timer->timer,
	387	msecs_to_jiffies(info->timeout * 1000) + jiffies);
	388	}
	389	pr_debug("increased refcnt of timer %s to %u\n",
	390	info->label, info->timer->refcnt);
	391	} else {
	392	ret = idletimer_tg_create_v1(info);
	393	if (ret < 0) {
	394	pr_debug("failed to create timer\n");
	395	mutex_unlock(&list_mutex);
	396	return ret;
	397	}
	398	}
	399
	400	mutex_unlock(&list_mutex);
	401	return 0;
	402	}
	403
0902b469 LC	404	static void idletimer_tg_destroy(const struct xt_tgdtor_param *par)
	405	{
	406	const struct idletimer_tg_info *info = par->targinfo;
	407
	408	pr_debug("destroy targinfo %s\n", info->label);
	409
	410	mutex_lock(&list_mutex);
	411
	412	if (--info->timer->refcnt == 0) {
	413	pr_debug("deleting timer %s\n", info->label);
	414
	415	list_del(&info->timer->entry);
292a089d	416	timer_shutdown_sync(&info->timer->timer);
cec5913c	417	cancel_work_sync(&info->timer->work);
0902b469 LC	418	sysfs_remove_file(idletimer_tg_kobj, &info->timer->attr.attr);
	419	kfree(info->timer->attr.attr.name);
	420	kfree(info->timer);
	421	} else {
	422	pr_debug("decreased refcnt of timer %s to %u\n",
	423	info->label, info->timer->refcnt);
	424	}
	425
	426	mutex_unlock(&list_mutex);
	427	}
	428
68983a35 MB	429	static void idletimer_tg_destroy_v1(const struct xt_tgdtor_param *par)
	430	{
	431	const struct idletimer_tg_info_v1 *info = par->targinfo;
	432
	433	pr_debug("destroy targinfo %s\n", info->label);
	434
	435	mutex_lock(&list_mutex);
	436
	437	if (--info->timer->refcnt == 0) {
	438	pr_debug("deleting timer %s\n", info->label);
	439
	440	list_del(&info->timer->entry);
	441	if (info->timer->timer_type & XT_IDLETIMER_ALARM) {
	442	alarm_cancel(&info->timer->alarm);
	443	} else {
292a089d	444	timer_shutdown_sync(&info->timer->timer);
68983a35 MB	445	}
	446	cancel_work_sync(&info->timer->work);
	447	sysfs_remove_file(idletimer_tg_kobj, &info->timer->attr.attr);
	448	kfree(info->timer->attr.attr.name);
	449	kfree(info->timer);
	450	} else {
	451	pr_debug("decreased refcnt of timer %s to %u\n",
	452	info->label, info->timer->refcnt);
	453	}
	454
	455	mutex_unlock(&list_mutex);
	456	}
	457
	458
	459	static struct xt_target idletimer_tg[] __read_mostly = {
	460	{
0902b469 LC	461	.name = "IDLETIMER",
	462	.family = NFPROTO_UNSPEC,
	463	.target = idletimer_tg_target,
	464	.targetsize = sizeof(struct idletimer_tg_info),
1e98ffea	465	.usersize = offsetof(struct idletimer_tg_info, timer),
0902b469 LC	466	.checkentry = idletimer_tg_checkentry,
	467	.destroy = idletimer_tg_destroy,
	468	.me = THIS_MODULE,
68983a35 MB	469	},
	470	{
	471	.name = "IDLETIMER",
	472	.family = NFPROTO_UNSPEC,
	473	.revision = 1,
	474	.target = idletimer_tg_target_v1,
	475	.targetsize = sizeof(struct idletimer_tg_info_v1),
	476	.usersize = offsetof(struct idletimer_tg_info_v1, timer),
	477	.checkentry = idletimer_tg_checkentry_v1,
	478	.destroy = idletimer_tg_destroy_v1,
	479	.me = THIS_MODULE,
	480	},
	481
	482
0902b469 LC	483	};
	484
	485	static struct class *idletimer_tg_class;
	486
	487	static struct device *idletimer_tg_device;
	488
	489	static int __init idletimer_tg_init(void)
	490	{
	491	int err;
	492
1aaba11d	493	idletimer_tg_class = class_create("xt_idletimer");
0902b469 LC	494	err = PTR_ERR(idletimer_tg_class);
	495	if (IS_ERR(idletimer_tg_class)) {
	496	pr_debug("couldn't register device class\n");
	497	goto out;
	498	}
	499
	500	idletimer_tg_device = device_create(idletimer_tg_class, NULL,
	501	MKDEV(0, 0), NULL, "timers");
	502	err = PTR_ERR(idletimer_tg_device);
	503	if (IS_ERR(idletimer_tg_device)) {
	504	pr_debug("couldn't register system device\n");
	505	goto out_class;
	506	}
	507
	508	idletimer_tg_kobj = &idletimer_tg_device->kobj;
	509
68983a35 MB	510	err = xt_register_targets(idletimer_tg, ARRAY_SIZE(idletimer_tg));
68983a35 MB	511
0902b469 LC	512	if (err < 0) {
	513	pr_debug("couldn't register xt target\n");
	514	goto out_dev;
	515	}
	516
	517	return 0;
	518	out_dev:
	519	device_destroy(idletimer_tg_class, MKDEV(0, 0));
	520	out_class:
	521	class_destroy(idletimer_tg_class);
	522	out:
	523	return err;
	524	}
	525
	526	static void __exit idletimer_tg_exit(void)
	527	{
68983a35	528	xt_unregister_targets(idletimer_tg, ARRAY_SIZE(idletimer_tg));
0902b469 LC	529
	530	device_destroy(idletimer_tg_class, MKDEV(0, 0));
	531	class_destroy(idletimer_tg_class);
	532	}
	533
	534	module_init(idletimer_tg_init);
	535	module_exit(idletimer_tg_exit);
	536
	537	MODULE_AUTHOR("Timo Teras <ext-timo.teras@nokia.com>");
	538	MODULE_AUTHOR("Luciano Coelho <luciano.coelho@nokia.com>");
	539	MODULE_DESCRIPTION("Xtables: idle time monitor");
	540	MODULE_LICENSE("GPL v2");
f1e231a3 JE	541	MODULE_ALIAS("ipt_IDLETIMER");
f1e231a3 JE	542	MODULE_ALIAS("ip6t_IDLETIMER");