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: I1723d44e02df864d63da7550766ea7d763076de2 Signed-off-by: Bhavya Sokke Mallikarjunappa <bsokke@codeaurora.org>
This commit is contained in:
Bhavya Sokke Mallikarjunappa
parent
1fb7ca1e67
commit
69e2af9b6e
|
|
@ -0,0 +1,55 @@
|
|||
/*
|
||||
* linux/include/linux/netfilter/xt_HARDIDLETIMER.h
|
||||
*
|
||||
* Header file for Xtables timer target module.
|
||||
*
|
||||
* Copyright (c) 2014, The Linux Foundation. All rights reserved.
|
||||
*
|
||||
* Copyright (C) 2004, 2010 Nokia Corporation
|
||||
*
|
||||
* Written by Timo Teras <ext-timo.teras@nokia.com>
|
||||
*
|
||||
* Converted to x_tables and forward-ported to 2.6.34
|
||||
* by Luciano Coelho <luciano.coelho@nokia.com>
|
||||
*
|
||||
* Contact: Luciano Coelho <luciano.coelho@nokia.com>
|
||||
*
|
||||
* 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.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program; if not, write to the Free Software
|
||||
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
|
||||
* 02110-1301 USA
|
||||
*/
|
||||
|
||||
#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
|
||||
|
|
@ -608,6 +608,20 @@ 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
|
||||
|
|
|
|||
|
|
@ -96,6 +96,7 @@ 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
|
||||
|
|
|
|||
|
|
@ -0,0 +1,380 @@
|
|||
/*
|
||||
* 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, The Linux Foundation. All rights reserved.
|
||||
*
|
||||
* 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>
|
||||
*
|
||||
* 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.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program; if not, write to the Free Software
|
||||
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
|
||||
* 02110-1301 USA
|
||||
*/
|
||||
|
||||
#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 (NLMSG_MAX_SIZE <= res) {
|
||||
pr_err("message too long (%d)", res);
|
||||
return;
|
||||
}
|
||||
res = snprintf(state_msg, NLMSG_MAX_SIZE, "STATE=%s",
|
||||
timer->active ? "active" : "inactive");
|
||||
if (NLMSG_MAX_SIZE <= res) {
|
||||
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);
|
||||
return;
|
||||
|
||||
|
||||
}
|
||||
|
||||
static
|
||||
struct hardidletimer_tg *__hardidletimer_tg_find_by_label(const char *label)
|
||||
{
|
||||
struct hardidletimer_tg *entry;
|
||||
|
||||
BUG_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->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 = S_IRUGO;
|
||||
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;
|
||||
}
|
||||
|
||||
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);
|
||||
|
||||
BUG_ON(!info->timer);
|
||||
|
||||
if (info->timer->active == false) {
|
||||
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;
|
||||
|
||||
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++;
|
||||
if (info->timer->active == false) {
|
||||
schedule_work(&info->timer->work);
|
||||
pr_debug("Starting Checkentry timer\n");
|
||||
}
|
||||
|
||||
info->timer->active = true;
|
||||
tout = ktime_set(info->timeout, 0);
|
||||
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);
|
||||
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@nokia.com>");
|
||||
MODULE_AUTHOR("Luciano Coelho <luciano.coelho@nokia.com>");
|
||||
MODULE_DESCRIPTION("Xtables: idle time monitor");
|
||||
MODULE_LICENSE("GPL v2");
|
||||
|
||||
Loading…
Reference in New Issue