1 files changed, 235 insertions, 13 deletions

diff --git a/net/netfilter/xt_IDLETIMER.c b/net/netfilter/xt_IDLETIMER.c
index f56d3ed93e56..75bd0e5dd312 100644
--- a/net/netfilter/xt_IDLETIMER.c
+++ b/net/netfilter/xt_IDLETIMER.c
@@ -18,6 +18,7 @@
 
 #include <linux/module.h>
 #include <linux/timer.h>
+#include <linux/alarmtimer.h>
 #include <linux/list.h>
 #include <linux/mutex.h>
 #include <linux/netfilter.h>
@@ -30,6 +31,7 @@
 
 struct idletimer_tg {
 	struct list_head entry;
+	struct alarm alarm;
 	struct timer_list timer;
 	struct work_struct work;
 
@@ -37,6 +39,7 @@ struct idletimer_tg {
 	struct device_attribute attr;
 
 	unsigned int refcnt;
+	u8 timer_type;
 };
 
 static LIST_HEAD(idletimer_tg_list);
@@ -62,20 +65,29 @@ static ssize_t idletimer_tg_show(struct device *dev,
 {
 	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)
-		expires = timer->timer.expires;
+	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))
-		return sprintf(buf, "%u\n",
-			       jiffies_to_msecs(expires - jiffies) / 1000);
+	if (time_after(expires, jiffies) || ktimespec.tv_sec > 0)
+		return snprintf(buf, PAGE_SIZE, "%ld\n", time_diff);
 
-	return sprintf(buf, "0\n");
+	return snprintf(buf, PAGE_SIZE, "0\n");
 }
 
 static void idletimer_tg_work(struct work_struct *work)
@@ -95,6 +107,16 @@ static void idletimer_tg_expired(struct timer_list *t)
 	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;
@@ -160,6 +182,68 @@ 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.
  */
@@ -177,13 +261,30 @@ static unsigned int idletimer_tg_target(struct sk_buff *skb,
 	return XT_CONTINUE;
 }
 
-static int idletimer_tg_checkentry(const struct xt_tgchk_param *par)
+/*
+ * The actual xt_tables plugin.
+ */
+static unsigned int idletimer_tg_target_v1(struct sk_buff *skb,
+					 const struct xt_action_param *par)
 {
-	struct idletimer_tg_info *info = par->targinfo;
-	int ret;
+	const struct idletimer_tg_info_v1 *info = par->targinfo;
 
-	pr_debug("checkentry targinfo%s\n", info->label);
+	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;
@@ -198,7 +299,23 @@ static int idletimer_tg_checkentry(const struct xt_tgchk_param *par)
 		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);
@@ -222,6 +339,65 @@ static int idletimer_tg_checkentry(const struct xt_tgchk_param *par)
 	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);
+
+	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;
@@ -247,7 +423,38 @@ static void idletimer_tg_destroy(const struct xt_tgdtor_param *par)
 	mutex_unlock(&list_mutex);
 }
 
-static struct xt_target idletimer_tg __read_mostly = {
+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 {
+			del_timer_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,
@@ -256,6 +463,20 @@ static struct xt_target idletimer_tg __read_mostly = {
 	.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;
@@ -283,7 +504,8 @@ static int __init idletimer_tg_init(void)
 
 	idletimer_tg_kobj = &idletimer_tg_device->kobj;
 
-	err = xt_register_target(&idletimer_tg);
+	err = xt_register_targets(idletimer_tg, ARRAY_SIZE(idletimer_tg));
+
 	if (err < 0) {
 		pr_debug("couldn't register xt target\n");
 		goto out_dev;
@@ -300,7 +522,7 @@ out:
 
 static void __exit idletimer_tg_exit(void)
 {
-	xt_unregister_target(&idletimer_tg);
+	xt_unregister_targets(idletimer_tg, ARRAY_SIZE(idletimer_tg));
 
 	device_destroy(idletimer_tg_class, MKDEV(0, 0));
 	class_destroy(idletimer_tg_class);