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Release 4.14 net/netfilter/xt_IDLETIMER.c

Directory: net/netfilter
/*
 * 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>
 *
 * 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/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_attr {
	
struct attribute attr;
	
ssize_t	(*show)(struct kobject *kobj,
			struct attribute *attr, char *buf);
};


struct idletimer_tg {
	
struct list_head entry;
	
struct timer_list timer;
	
struct work_struct work;

	
struct kobject *kobj;
	
struct idletimer_tg_attr attr;

	
unsigned int refcnt;
};

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; BUG_ON(!label); list_for_each_entry(entry, &idletimer_tg_list, entry) { if (!strcmp(label, entry->attr.attr.name)) return entry; } return NULL; }

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Luciano Coelho56100.00%1100.00%
Total56100.00%1100.00%


static ssize_t idletimer_tg_show(struct kobject *kobj, struct attribute *attr, char *buf) { struct idletimer_tg *timer; unsigned long expires = 0; mutex_lock(&list_mutex); timer = __idletimer_tg_find_by_label(attr->name); if (timer) expires = timer->timer.expires; mutex_unlock(&list_mutex); if (time_after(expires, jiffies)) return sprintf(buf, "%u\n", jiffies_to_msecs(expires - jiffies) / 1000); return sprintf(buf, "0\n"); }

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Luciano Coelho98100.00%1100.00%
Total98100.00%1100.00%


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); }

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Luciano Coelho41100.00%1100.00%
Total41100.00%1100.00%


static void idletimer_tg_expired(unsigned long data) { struct idletimer_tg *timer = (struct idletimer_tg *) data; pr_debug("timer %s expired\n", timer->attr.attr.name); schedule_work(&timer->work); }

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Luciano Coelho43100.00%1100.00%
Total43100.00%1100.00%


static int idletimer_tg_create(struct idletimer_tg_info *info) { int ret; info->timer = kmalloc(sizeof(*info->timer), GFP_KERNEL); if (!info->timer) { ret = -ENOMEM; goto out; } 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 = S_IRUGO; 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); setup_timer(&info->timer->timer, idletimer_tg_expired, (unsigned long) info->timer); info->timer->refcnt = 1; mod_timer(&info->timer->timer, msecs_to_jiffies(info->timeout * 1000) + jiffies); INIT_WORK(&info->timer->work, idletimer_tg_work); return 0; out_free_attr: kfree(info->timer->attr.attr.name); out_free_timer: kfree(info->timer); out: return ret; }

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Luciano Coelho25095.42%150.00%
Dmitry Torokhov124.58%150.00%
Total262100.00%2100.00%

/* * 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); BUG_ON(!info->timer); mod_timer(&info->timer->timer, msecs_to_jiffies(info->timeout * 1000) + jiffies); return XT_CONTINUE; }

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PersonTokensPropCommitsCommitProp
Luciano Coelho73100.00%1100.00%
Total73100.00%1100.00%


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); if (info->timeout == 0) { pr_debug("timeout value is zero\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; } 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; }

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Luciano Coelho194100.00%1100.00%
Total194100.00%1100.00%


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); }

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Luciano Coelho13793.20%150.00%
Liping Zhang106.80%150.00%
Total147100.00%2100.00%

static struct xt_target idletimer_tg __read_mostly = { .name = "IDLETIMER", .family = NFPROTO_UNSPEC, .target = idletimer_tg_target, .targetsize = sizeof(struct idletimer_tg_info), .checkentry = idletimer_tg_checkentry, .destroy = idletimer_tg_destroy, .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_target(&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; }

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Luciano Coelho149100.00%1100.00%
Total149100.00%1100.00%


static void __exit idletimer_tg_exit(void) { xt_unregister_target(&idletimer_tg); device_destroy(idletimer_tg_class, MKDEV(0, 0)); class_destroy(idletimer_tg_class); }

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Luciano Coelho32100.00%1100.00%
Total32100.00%1100.00%

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");

Overall Contributors

PersonTokensPropCommitsCommitProp
Luciano Coelho127997.34%120.00%
Dmitry Torokhov120.91%120.00%
Liping Zhang100.76%120.00%
Jan Engelhardt100.76%120.00%
Randy Dunlap30.23%120.00%
Total1314100.00%5100.00%
Directory: net/netfilter
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