1 files changed, 542 insertions, 0 deletions

diff --git a/net/netfilter/xt_IDLETIMER.c b/net/netfilter/xt_IDLETIMER.c
new file mode 100644
index 000000000..0f8bb0bf5
--- /dev/null
+++ b/net/netfilter/xt_IDLETIMER.c
@@ -0,0 +1,542 @@
+// 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);
+		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 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,
+	.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(THIS_MODULE, "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");