This is a snapshot of hardifletimer netfilter target as of msm-4.4
commit 469a150b7426 ("netfilter: xtables: hardidletimer target implementation")
This patch implements a hardidletimer Xtables target that can be
used to identify when interfaces have been idle for a certain period
of time.
Timers are identified by labels and are created when a rule is set
with a new label. The rules also take a timeout value (in seconds) as
an option. If more than one rule uses the same timer label, the timer
will be restarted whenever any of the rules get a hit.
One entry for each timer is created in sysfs. This attribute contains
the timer remaining for the timer to expire. The attributes are
located under the xt_idletimer class:
/sys/class/xt_hardidletimer/timers/<label>
When the timer expires, the target module sends a sysfs notification
to the userspace, which can then decide what to do (eg. disconnect to
save power)
Compared to xt_IDLETIMER, xt_HARDIDLETIMER can send notifications when
CPU is in suspend too, to notify the timer expiry.
Change-Id: Ib2e05af7267f3c86d1967f149f7e7e782c59807e
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@xxxxxxxxxxxxxx>
Signed-off-by: Manoj Basapathi <manojbm@xxxxxxxxxxxxxx>
---
.../uapi/linux/netfilter/xt_HARDIDLETIMER.h | 51 +++
net/netfilter/Kconfig | 14 +
net/netfilter/Makefile | 1 +
net/netfilter/xt_HARDIDLETIMER.c | 381 ++++++++++++++++++
net/netfilter/xt_IDLETIMER.c | 2 +
5 files changed, 449 insertions(+)
create mode 100644 include/uapi/linux/netfilter/xt_HARDIDLETIMER.h
create mode 100644 net/netfilter/xt_HARDIDLETIMER.c
diff --git a/include/uapi/linux/netfilter/xt_HARDIDLETIMER.h b/include/uapi/linux/netfilter/xt_HARDIDLETIMER.h
new file mode 100644
index 000000000000..7cd4a2e39b86
--- /dev/null
+++ b/include/uapi/linux/netfilter/xt_HARDIDLETIMER.h
@@ -0,0 +1,51 @@
+/*
+ * linux/include/linux/netfilter/xt_HARDIDLETIMER.h
+ *
+ * Header file for Xtables timer target module.
+ *
+ * Copyright (c) 2014, 2017 The Linux Foundation. All rights reserved.
+ *
+ * Copyright (C) 2004, 2010 Nokia Corporation
+ *
+ * Written by Timo Teras <ext-timo.teras@xxxxxxxxx>
+ *
+ * Converted to x_tables and forward-ported to 2.6.34
+ * by Luciano Coelho <luciano.coelho@xxxxxxxxx>
+ *
+ * Contact: Luciano Coelho <luciano.coelho@xxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ */
+
+#ifndef _XT_HARDIDLETIMER_H
+#define _XT_HARDIDLETIMER_H
+
+#include <linux/types.h>
+
+#define MAX_HARDIDLETIMER_LABEL_SIZE 28
+#define NLMSG_MAX_SIZE 64
+
+#define NL_EVENT_TYPE_INACTIVE 0
+#define NL_EVENT_TYPE_ACTIVE 1
+
+struct hardidletimer_tg_info {
+ __u32 timeout;
+
+ char label[MAX_HARDIDLETIMER_LABEL_SIZE];
+
+ /* Use netlink messages for notification in addition to sysfs */
+ __u8 send_nl_msg;
+
+ /* for kernel module internal use only */
+ struct hardidletimer_tg *timer __attribute__((aligned(8)));
+};
+
+#endif
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 91efae88e8c2..cd0ce929a59f 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -893,6 +893,20 @@ config NETFILTER_XT_TARGET_IDLETIMER
To compile it as a module, choose M here. If unsure, say N.
+config NETFILTER_XT_TARGET_HARDIDLETIMER
+ tristate "HARDIDLETIMER target support"
+ depends on NETFILTER_ADVANCED
+ help
+
+ This option adds the `HARDIDLETIMER' target. Each matching packet
+ resets the timer associated with label specified when the rule is
+ added. When the timer expires, it triggers a sysfs notification.
+ The remaining time for expiration can be read via sysfs.
+ Compared to IDLETIMER HARDIDLETIMER will send notification when
+ CPU in suspend too.
+
+ To compile it as a module, choose M here. If unsure, say N.
+
config NETFILTER_XT_TARGET_LED
tristate '"LED" target support'
depends on LEDS_CLASS && LEDS_TRIGGERS
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 4fc075b612fe..ecbe48437fbd 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -157,6 +157,7 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_TCPOPTSTRIP) += xt_TCPOPTSTRIP.o
obj-$(CONFIG_NETFILTER_XT_TARGET_TEE) += xt_TEE.o
obj-$(CONFIG_NETFILTER_XT_TARGET_TRACE) += xt_TRACE.o
obj-$(CONFIG_NETFILTER_XT_TARGET_IDLETIMER) += xt_IDLETIMER.o
+obj-$(CONFIG_NETFILTER_XT_TARGET_HARDIDLETIMER) += xt_HARDIDLETIMER.o
# matches
obj-$(CONFIG_NETFILTER_XT_MATCH_ADDRTYPE) += xt_addrtype.o
diff --git a/net/netfilter/xt_HARDIDLETIMER.c b/net/netfilter/xt_HARDIDLETIMER.c
new file mode 100644
index 000000000000..ea8b103a3f39
--- /dev/null
+++ b/net/netfilter/xt_HARDIDLETIMER.c
@@ -0,0 +1,381 @@
+/*
+ * linux/net/netfilter/xt_HARDIDLETIMER.c
+ *
+ * Netfilter module to trigger a timer when packet matches.
+ * After timer expires a kevent will be sent.
+ *
+ * Copyright (c) 2014-2015, 2017-2018, The Linux Foundation.
+ * All rights reserved.
+ *
+ * Copyright (C) 2004, 2010 Nokia Corporation
+ *
+ * Written by Timo Teras <ext-timo.teras@xxxxxxxxx>
+ *
+ * Converted to x_tables and reworked for upstream inclusion
+ * by Luciano Coelho <luciano.coelho@xxxxxxxxx>
+ *
+ * Contact: Luciano Coelho <luciano.coelho@xxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ */
+
+#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_HARDIDLETIMER.h>
+#include <linux/kdev_t.h>
+#include <linux/kobject.h>
+#include <linux/skbuff.h>
+#include <linux/workqueue.h>
+#include <linux/sysfs.h>
+#include <net/net_namespace.h>
+
+struct hardidletimer_tg_attr {
+ struct attribute attr;
+ ssize_t (*show)(struct kobject *kobj,
+ struct attribute *attr, char *buf);
+};
+
+struct hardidletimer_tg {
+ struct list_head entry;
+ struct alarm alarm;
+ struct work_struct work;
+
+ struct kobject *kobj;
+ struct hardidletimer_tg_attr attr;
+
+ unsigned int refcnt;
+ bool send_nl_msg;
+ bool active;
+};
+
+static LIST_HEAD(hardidletimer_tg_list);
+static DEFINE_MUTEX(list_mutex);
+
+static struct kobject *hardidletimer_tg_kobj;
+
+static void notify_netlink_uevent(const char *iface,
+ struct hardidletimer_tg *timer)
+{
+ char iface_msg[NLMSG_MAX_SIZE];
+ char state_msg[NLMSG_MAX_SIZE];
+ char *envp[] = { iface_msg, state_msg, NULL };
+ int res;
+
+ res = snprintf(iface_msg, NLMSG_MAX_SIZE, "INTERFACE=%s",
+ iface);
+ if (res >= NLMSG_MAX_SIZE) {
+ pr_err("message too long (%d)", res);
+ return;
+ }
+ res = snprintf(state_msg, NLMSG_MAX_SIZE, "STATE=%s",
+ timer->active ? "active" : "inactive");
+ if (res >= NLMSG_MAX_SIZE) {
+ pr_err("message too long (%d)", res);
+ return;
+ }
+ pr_debug("putting nlmsg: <%s> <%s>\n", iface_msg, state_msg);
+ kobject_uevent_env(hardidletimer_tg_kobj, KOBJ_CHANGE, envp);
+}
+
+static
+struct hardidletimer_tg *__hardidletimer_tg_find_by_label(const char *label)
+{
+ struct hardidletimer_tg *entry;
+
+ WARN_ON(!label);
+
+ list_for_each_entry(entry, &hardidletimer_tg_list, entry) {
+ if (!strcmp(label, entry->attr.attr.name))
+ return entry;
+ }
+
+ return NULL;
+}
+
+static ssize_t hardidletimer_tg_show(struct kobject *kobj,
+ struct attribute *attr, char *buf)
+{
+ struct hardidletimer_tg *timer;
+ ktime_t expires;
+ struct timespec ktimespec;
+
+ memset(&ktimespec, 0, sizeof(struct timespec));
+ mutex_lock(&list_mutex);
+
+ timer = __hardidletimer_tg_find_by_label(attr->name);
+ if (timer) {
+ expires = alarm_expires_remaining(&timer->alarm);
+ ktimespec = ktime_to_timespec(expires);
+ }
+
+ mutex_unlock(&list_mutex);
+
+ if (ktimespec.tv_sec >= 0)
+ return snprintf(buf, PAGE_SIZE, "%ld\n", ktimespec.tv_sec);
+
+ if ((timer) && timer->send_nl_msg)
+ return snprintf(buf, PAGE_SIZE, "0 %ld\n", ktimespec.tv_sec);
+ else
+ return snprintf(buf, PAGE_SIZE, "0\n");
+}
+
+static void hardidletimer_tg_work(struct work_struct *work)
+{
+ struct hardidletimer_tg *timer = container_of(work,
+ struct hardidletimer_tg, work);
+
+ sysfs_notify(hardidletimer_tg_kobj, NULL, timer->attr.attr.name);
+
+ if (timer->send_nl_msg)
+ notify_netlink_uevent(timer->attr.attr.name, timer);
+}
+
+static enum alarmtimer_restart hardidletimer_tg_alarmproc(struct alarm *alarm,
+ ktime_t now)
+{
+ struct hardidletimer_tg *timer = alarm->data;
+
+ pr_debug("alarm %s expired\n", timer->attr.attr.name);
+
+ timer->active = false;
+ schedule_work(&timer->work);
+ return ALARMTIMER_NORESTART;
+}
+
+static int hardidletimer_tg_create(struct hardidletimer_tg_info *info)
+{
+ int ret;
+ ktime_t tout;
+
+ info->timer = kmalloc(sizeof(*info->timer), GFP_KERNEL);
+ if (!info->timer) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ 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 = hardidletimer_tg_show;
+
+ ret = sysfs_create_file(hardidletimer_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(hardidletimer_tg_kobj, KOBJ_ADD);
+
+ list_add(&info->timer->entry, &hardidletimer_tg_list);
+
+ alarm_init(&info->timer->alarm, ALARM_BOOTTIME,
+ hardidletimer_tg_alarmproc);
+ info->timer->alarm.data = info->timer;
+ info->timer->refcnt = 1;
+ info->timer->send_nl_msg = (info->send_nl_msg == 0) ? false : true;
+ info->timer->active = true;
+ tout = ktime_set(info->timeout, 0);
+ alarm_start_relative(&info->timer->alarm, tout);
+
+ INIT_WORK(&info->timer->work, hardidletimer_tg_work);
+
+ 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 hardidletimer_tg_target(struct sk_buff *skb,
+ const struct xt_action_param *par)
+{
+ const struct hardidletimer_tg_info *info = par->targinfo;
+ ktime_t tout;
+
+ pr_debug("resetting timer %s, timeout period %u\n",
+ info->label, info->timeout);
+
+ WARN_ON(!info->timer);
+
+ if (!info->timer->active) {
+ schedule_work(&info->timer->work);
+ pr_debug("Starting timer %s\n", info->label);
+ }
+
+ info->timer->active = true;
+ /* TODO: Avoid modifying timers on each packet */
+ tout = ktime_set(info->timeout, 0);
+ alarm_start_relative(&info->timer->alarm, tout);
+
+ return XT_CONTINUE;
+}
+
+static int hardidletimer_tg_checkentry(const struct xt_tgchk_param *par)
+{
+ struct hardidletimer_tg_info *info = par->targinfo;
+ int ret;
+ ktime_t tout;
+ struct timespec ktimespec;
+
+ memset(&ktimespec, 0, sizeof(struct timespec));
+
+ pr_debug("checkentry targinfo %s\n", info->label);
+
+ if (info->timeout == 0) {
+ pr_debug("timeout value is zero\n");
+ return -EINVAL;
+ }
+
+ if (info->label[0] == '\0' ||
+ strnlen(info->label, MAX_HARDIDLETIMER_LABEL_SIZE)
+ == MAX_HARDIDLETIMER_LABEL_SIZE) {
+ pr_debug("label is empty or not nul-terminated\n");
+ return -EINVAL;
+ }
+
+ mutex_lock(&list_mutex);
+
+ info->timer = __hardidletimer_tg_find_by_label(info->label);
+ if (info->timer) {
+ info->timer->refcnt++;
+ /* calculate remaining expiry time */
+ tout = alarm_expires_remaining(&info->timer->alarm);
+ ktimespec = ktime_to_timespec(tout);
+
+ if (ktimespec.tv_sec > 0) {
+ pr_debug("time_expiry_remaining %ld\n",
+ ktimespec.tv_sec);
+ alarm_start_relative(&info->timer->alarm, tout);
+ }
+
+ pr_debug("increased refcnt of timer %s to %u\n",
+ info->label, info->timer->refcnt);
+ } else {
+ ret = hardidletimer_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 void hardidletimer_tg_destroy(const struct xt_tgdtor_param *par)
+{
+ const struct hardidletimer_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);
+ alarm_cancel(&info->timer->alarm);
+ cancel_work_sync(&info->timer->work);
+ sysfs_remove_file(hardidletimer_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 hardidletimer_tg __read_mostly = {
+ .name = "HARDIDLETIMER",
+ .revision = 1,
+ .family = NFPROTO_UNSPEC,
+ .target = hardidletimer_tg_target,
+ .targetsize = sizeof(struct hardidletimer_tg_info),
+ .checkentry = hardidletimer_tg_checkentry,
+ .destroy = hardidletimer_tg_destroy,
+ .me = THIS_MODULE,
+};
+
+static struct class *hardidletimer_tg_class;
+
+static struct device *hardidletimer_tg_device;
+
+static int __init hardidletimer_tg_init(void)
+{
+ int err;
+
+ hardidletimer_tg_class = class_create(THIS_MODULE, "xt_hardidletimer");
+ err = PTR_ERR(hardidletimer_tg_class);
+ if (IS_ERR(hardidletimer_tg_class)) {
+ pr_debug("couldn't register device class\n");
+ goto out;
+ }
+
+ hardidletimer_tg_device = device_create(hardidletimer_tg_class, NULL,
+ MKDEV(0, 0), NULL, "timers");
+ err = PTR_ERR(hardidletimer_tg_device);
+ if (IS_ERR(hardidletimer_tg_device)) {
+ pr_debug("couldn't register system device\n");
+ goto out_class;
+ }
+
+ hardidletimer_tg_kobj = &hardidletimer_tg_device->kobj;
+
+ err = xt_register_target(&hardidletimer_tg);
+ if (err < 0) {
+ pr_debug("couldn't register xt target\n");
+ goto out_dev;
+ }
+
+ return 0;
+out_dev:
+ device_destroy(hardidletimer_tg_class, MKDEV(0, 0));
+out_class:
+ class_destroy(hardidletimer_tg_class);
+out:
+ return err;
+}
+
+static void __exit hardidletimer_tg_exit(void)
+{
+ xt_unregister_target(&hardidletimer_tg);
+
+ device_destroy(hardidletimer_tg_class, MKDEV(0, 0));
+ class_destroy(hardidletimer_tg_class);
+}
+
+module_init(hardidletimer_tg_init);
+module_exit(hardidletimer_tg_exit);
+
+MODULE_AUTHOR("Timo Teras <ext-timo.teras@xxxxxxxxx>");
+MODULE_AUTHOR("Luciano Coelho <luciano.coelho@xxxxxxxxx>");
+MODULE_DESCRIPTION("Xtables: idle time monitor");
+MODULE_LICENSE("GPL v2");
+
diff --git a/net/netfilter/xt_IDLETIMER.c b/net/netfilter/xt_IDLETIMER.c
index f56d3ed93e56..68491e1bb66d 100644
--- a/net/netfilter/xt_IDLETIMER.c
+++ b/net/netfilter/xt_IDLETIMER.c
@@ -139,6 +139,8 @@ static int idletimer_tg_create(struct idletimer_tg_info *info)
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);
--
2.23.0
