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![Greg Kroah-Hartman](/assets/img/avatar_default.png)
The module pointer in class_create() never actually did anything, and it shouldn't have been requred to be set as a parameter even if it did something. So just remove it and fix up all callers of the function in the kernel tree at the same time. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Link: https://lore.kernel.org/r/20230313181843.1207845-4-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
542 lines
13 KiB
C
542 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* linux/net/netfilter/xt_IDLETIMER.c
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*
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* Netfilter module to trigger a timer when packet matches.
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* After timer expires a kevent will be sent.
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*
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* Copyright (C) 2004, 2010 Nokia Corporation
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* Written by Timo Teras <ext-timo.teras@nokia.com>
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*
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* Converted to x_tables and reworked for upstream inclusion
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* by Luciano Coelho <luciano.coelho@nokia.com>
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*
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* Contact: Luciano Coelho <luciano.coelho@nokia.com>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/timer.h>
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#include <linux/alarmtimer.h>
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#include <linux/list.h>
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#include <linux/mutex.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter/xt_IDLETIMER.h>
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#include <linux/kdev_t.h>
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#include <linux/kobject.h>
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#include <linux/workqueue.h>
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#include <linux/sysfs.h>
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struct idletimer_tg {
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struct list_head entry;
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struct alarm alarm;
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struct timer_list timer;
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struct work_struct work;
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struct kobject *kobj;
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struct device_attribute attr;
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unsigned int refcnt;
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u8 timer_type;
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};
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static LIST_HEAD(idletimer_tg_list);
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static DEFINE_MUTEX(list_mutex);
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static struct kobject *idletimer_tg_kobj;
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static
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struct idletimer_tg *__idletimer_tg_find_by_label(const char *label)
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{
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struct idletimer_tg *entry;
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list_for_each_entry(entry, &idletimer_tg_list, entry) {
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if (!strcmp(label, entry->attr.attr.name))
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return entry;
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}
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return NULL;
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}
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static ssize_t idletimer_tg_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct idletimer_tg *timer;
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unsigned long expires = 0;
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struct timespec64 ktimespec = {};
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long time_diff = 0;
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mutex_lock(&list_mutex);
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timer = __idletimer_tg_find_by_label(attr->attr.name);
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if (timer) {
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if (timer->timer_type & XT_IDLETIMER_ALARM) {
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ktime_t expires_alarm = alarm_expires_remaining(&timer->alarm);
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ktimespec = ktime_to_timespec64(expires_alarm);
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time_diff = ktimespec.tv_sec;
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} else {
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expires = timer->timer.expires;
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time_diff = jiffies_to_msecs(expires - jiffies) / 1000;
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}
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}
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mutex_unlock(&list_mutex);
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if (time_after(expires, jiffies) || ktimespec.tv_sec > 0)
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return sysfs_emit(buf, "%ld\n", time_diff);
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return sysfs_emit(buf, "0\n");
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}
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static void idletimer_tg_work(struct work_struct *work)
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{
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struct idletimer_tg *timer = container_of(work, struct idletimer_tg,
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work);
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sysfs_notify(idletimer_tg_kobj, NULL, timer->attr.attr.name);
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}
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static void idletimer_tg_expired(struct timer_list *t)
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{
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struct idletimer_tg *timer = from_timer(timer, t, timer);
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pr_debug("timer %s expired\n", timer->attr.attr.name);
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schedule_work(&timer->work);
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}
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static enum alarmtimer_restart idletimer_tg_alarmproc(struct alarm *alarm,
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ktime_t now)
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{
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struct idletimer_tg *timer = alarm->data;
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pr_debug("alarm %s expired\n", timer->attr.attr.name);
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schedule_work(&timer->work);
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return ALARMTIMER_NORESTART;
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}
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static int idletimer_check_sysfs_name(const char *name, unsigned int size)
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{
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int ret;
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ret = xt_check_proc_name(name, size);
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if (ret < 0)
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return ret;
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if (!strcmp(name, "power") ||
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!strcmp(name, "subsystem") ||
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!strcmp(name, "uevent"))
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return -EINVAL;
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return 0;
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}
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static int idletimer_tg_create(struct idletimer_tg_info *info)
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{
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int ret;
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info->timer = kzalloc(sizeof(*info->timer), GFP_KERNEL);
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if (!info->timer) {
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ret = -ENOMEM;
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goto out;
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}
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ret = idletimer_check_sysfs_name(info->label, sizeof(info->label));
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if (ret < 0)
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goto out_free_timer;
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sysfs_attr_init(&info->timer->attr.attr);
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info->timer->attr.attr.name = kstrdup(info->label, GFP_KERNEL);
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if (!info->timer->attr.attr.name) {
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ret = -ENOMEM;
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goto out_free_timer;
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}
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info->timer->attr.attr.mode = 0444;
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info->timer->attr.show = idletimer_tg_show;
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ret = sysfs_create_file(idletimer_tg_kobj, &info->timer->attr.attr);
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if (ret < 0) {
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pr_debug("couldn't add file to sysfs");
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goto out_free_attr;
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}
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list_add(&info->timer->entry, &idletimer_tg_list);
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timer_setup(&info->timer->timer, idletimer_tg_expired, 0);
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info->timer->refcnt = 1;
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INIT_WORK(&info->timer->work, idletimer_tg_work);
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mod_timer(&info->timer->timer,
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msecs_to_jiffies(info->timeout * 1000) + jiffies);
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return 0;
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out_free_attr:
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kfree(info->timer->attr.attr.name);
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out_free_timer:
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kfree(info->timer);
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out:
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return ret;
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}
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static int idletimer_tg_create_v1(struct idletimer_tg_info_v1 *info)
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{
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int ret;
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info->timer = kmalloc(sizeof(*info->timer), GFP_KERNEL);
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if (!info->timer) {
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ret = -ENOMEM;
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goto out;
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}
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ret = idletimer_check_sysfs_name(info->label, sizeof(info->label));
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if (ret < 0)
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goto out_free_timer;
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sysfs_attr_init(&info->timer->attr.attr);
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info->timer->attr.attr.name = kstrdup(info->label, GFP_KERNEL);
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if (!info->timer->attr.attr.name) {
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ret = -ENOMEM;
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goto out_free_timer;
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}
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info->timer->attr.attr.mode = 0444;
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info->timer->attr.show = idletimer_tg_show;
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ret = sysfs_create_file(idletimer_tg_kobj, &info->timer->attr.attr);
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if (ret < 0) {
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pr_debug("couldn't add file to sysfs");
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goto out_free_attr;
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}
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/* notify userspace */
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kobject_uevent(idletimer_tg_kobj,KOBJ_ADD);
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list_add(&info->timer->entry, &idletimer_tg_list);
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pr_debug("timer type value is %u", info->timer_type);
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info->timer->timer_type = info->timer_type;
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info->timer->refcnt = 1;
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INIT_WORK(&info->timer->work, idletimer_tg_work);
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if (info->timer->timer_type & XT_IDLETIMER_ALARM) {
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ktime_t tout;
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alarm_init(&info->timer->alarm, ALARM_BOOTTIME,
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idletimer_tg_alarmproc);
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info->timer->alarm.data = info->timer;
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tout = ktime_set(info->timeout, 0);
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alarm_start_relative(&info->timer->alarm, tout);
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} else {
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timer_setup(&info->timer->timer, idletimer_tg_expired, 0);
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mod_timer(&info->timer->timer,
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msecs_to_jiffies(info->timeout * 1000) + jiffies);
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}
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return 0;
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out_free_attr:
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kfree(info->timer->attr.attr.name);
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out_free_timer:
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kfree(info->timer);
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out:
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return ret;
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}
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/*
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* The actual xt_tables plugin.
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*/
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static unsigned int idletimer_tg_target(struct sk_buff *skb,
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const struct xt_action_param *par)
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{
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const struct idletimer_tg_info *info = par->targinfo;
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pr_debug("resetting timer %s, timeout period %u\n",
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info->label, info->timeout);
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mod_timer(&info->timer->timer,
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msecs_to_jiffies(info->timeout * 1000) + jiffies);
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return XT_CONTINUE;
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}
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/*
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* The actual xt_tables plugin.
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*/
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static unsigned int idletimer_tg_target_v1(struct sk_buff *skb,
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const struct xt_action_param *par)
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{
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const struct idletimer_tg_info_v1 *info = par->targinfo;
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pr_debug("resetting timer %s, timeout period %u\n",
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info->label, info->timeout);
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if (info->timer->timer_type & XT_IDLETIMER_ALARM) {
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ktime_t tout = ktime_set(info->timeout, 0);
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alarm_start_relative(&info->timer->alarm, tout);
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} else {
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mod_timer(&info->timer->timer,
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msecs_to_jiffies(info->timeout * 1000) + jiffies);
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}
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return XT_CONTINUE;
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}
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static int idletimer_tg_helper(struct idletimer_tg_info *info)
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{
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if (info->timeout == 0) {
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pr_debug("timeout value is zero\n");
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return -EINVAL;
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}
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if (info->timeout >= INT_MAX / 1000) {
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pr_debug("timeout value is too big\n");
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return -EINVAL;
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}
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if (info->label[0] == '\0' ||
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strnlen(info->label,
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MAX_IDLETIMER_LABEL_SIZE) == MAX_IDLETIMER_LABEL_SIZE) {
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pr_debug("label is empty or not nul-terminated\n");
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return -EINVAL;
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}
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return 0;
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}
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static int idletimer_tg_checkentry(const struct xt_tgchk_param *par)
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{
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struct idletimer_tg_info *info = par->targinfo;
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int ret;
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pr_debug("checkentry targinfo%s\n", info->label);
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ret = idletimer_tg_helper(info);
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if(ret < 0)
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{
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pr_debug("checkentry helper return invalid\n");
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return -EINVAL;
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}
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mutex_lock(&list_mutex);
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info->timer = __idletimer_tg_find_by_label(info->label);
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if (info->timer) {
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info->timer->refcnt++;
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mod_timer(&info->timer->timer,
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msecs_to_jiffies(info->timeout * 1000) + jiffies);
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pr_debug("increased refcnt of timer %s to %u\n",
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info->label, info->timer->refcnt);
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} else {
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ret = idletimer_tg_create(info);
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if (ret < 0) {
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pr_debug("failed to create timer\n");
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mutex_unlock(&list_mutex);
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return ret;
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}
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}
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mutex_unlock(&list_mutex);
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return 0;
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}
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static int idletimer_tg_checkentry_v1(const struct xt_tgchk_param *par)
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{
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struct idletimer_tg_info_v1 *info = par->targinfo;
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int ret;
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pr_debug("checkentry targinfo%s\n", info->label);
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if (info->send_nl_msg)
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return -EOPNOTSUPP;
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ret = idletimer_tg_helper((struct idletimer_tg_info *)info);
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if(ret < 0)
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{
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pr_debug("checkentry helper return invalid\n");
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return -EINVAL;
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}
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if (info->timer_type > XT_IDLETIMER_ALARM) {
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pr_debug("invalid value for timer type\n");
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return -EINVAL;
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}
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mutex_lock(&list_mutex);
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info->timer = __idletimer_tg_find_by_label(info->label);
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if (info->timer) {
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if (info->timer->timer_type != info->timer_type) {
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pr_debug("Adding/Replacing rule with same label and different timer type is not allowed\n");
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mutex_unlock(&list_mutex);
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return -EINVAL;
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}
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info->timer->refcnt++;
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if (info->timer_type & XT_IDLETIMER_ALARM) {
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/* calculate remaining expiry time */
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ktime_t tout = alarm_expires_remaining(&info->timer->alarm);
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struct timespec64 ktimespec = ktime_to_timespec64(tout);
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if (ktimespec.tv_sec > 0) {
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pr_debug("time_expiry_remaining %lld\n",
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ktimespec.tv_sec);
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alarm_start_relative(&info->timer->alarm, tout);
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}
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} else {
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mod_timer(&info->timer->timer,
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msecs_to_jiffies(info->timeout * 1000) + jiffies);
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}
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pr_debug("increased refcnt of timer %s to %u\n",
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info->label, info->timer->refcnt);
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} else {
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ret = idletimer_tg_create_v1(info);
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if (ret < 0) {
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pr_debug("failed to create timer\n");
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mutex_unlock(&list_mutex);
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return ret;
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}
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}
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mutex_unlock(&list_mutex);
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return 0;
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}
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static void idletimer_tg_destroy(const struct xt_tgdtor_param *par)
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{
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const struct idletimer_tg_info *info = par->targinfo;
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pr_debug("destroy targinfo %s\n", info->label);
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mutex_lock(&list_mutex);
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if (--info->timer->refcnt == 0) {
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pr_debug("deleting timer %s\n", info->label);
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list_del(&info->timer->entry);
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timer_shutdown_sync(&info->timer->timer);
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cancel_work_sync(&info->timer->work);
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sysfs_remove_file(idletimer_tg_kobj, &info->timer->attr.attr);
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kfree(info->timer->attr.attr.name);
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kfree(info->timer);
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} else {
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pr_debug("decreased refcnt of timer %s to %u\n",
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info->label, info->timer->refcnt);
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}
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mutex_unlock(&list_mutex);
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}
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static void idletimer_tg_destroy_v1(const struct xt_tgdtor_param *par)
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{
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const struct idletimer_tg_info_v1 *info = par->targinfo;
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pr_debug("destroy targinfo %s\n", info->label);
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mutex_lock(&list_mutex);
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if (--info->timer->refcnt == 0) {
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pr_debug("deleting timer %s\n", info->label);
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list_del(&info->timer->entry);
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if (info->timer->timer_type & XT_IDLETIMER_ALARM) {
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alarm_cancel(&info->timer->alarm);
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} else {
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timer_shutdown_sync(&info->timer->timer);
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}
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cancel_work_sync(&info->timer->work);
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sysfs_remove_file(idletimer_tg_kobj, &info->timer->attr.attr);
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kfree(info->timer->attr.attr.name);
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kfree(info->timer);
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} else {
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pr_debug("decreased refcnt of timer %s to %u\n",
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info->label, info->timer->refcnt);
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}
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mutex_unlock(&list_mutex);
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}
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static struct xt_target idletimer_tg[] __read_mostly = {
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{
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.name = "IDLETIMER",
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.family = NFPROTO_UNSPEC,
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.target = idletimer_tg_target,
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.targetsize = sizeof(struct idletimer_tg_info),
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.usersize = offsetof(struct idletimer_tg_info, timer),
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.checkentry = idletimer_tg_checkentry,
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.destroy = idletimer_tg_destroy,
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.me = THIS_MODULE,
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},
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{
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.name = "IDLETIMER",
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.family = NFPROTO_UNSPEC,
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.revision = 1,
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.target = idletimer_tg_target_v1,
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.targetsize = sizeof(struct idletimer_tg_info_v1),
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.usersize = offsetof(struct idletimer_tg_info_v1, timer),
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.checkentry = idletimer_tg_checkentry_v1,
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.destroy = idletimer_tg_destroy_v1,
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.me = THIS_MODULE,
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},
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};
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static struct class *idletimer_tg_class;
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static struct device *idletimer_tg_device;
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static int __init idletimer_tg_init(void)
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{
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int err;
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idletimer_tg_class = class_create("xt_idletimer");
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err = PTR_ERR(idletimer_tg_class);
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if (IS_ERR(idletimer_tg_class)) {
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pr_debug("couldn't register device class\n");
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goto out;
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}
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idletimer_tg_device = device_create(idletimer_tg_class, NULL,
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MKDEV(0, 0), NULL, "timers");
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err = PTR_ERR(idletimer_tg_device);
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if (IS_ERR(idletimer_tg_device)) {
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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");
|