diff options
| -rw-r--r-- | include/linux/netfilter/Kbuild | 1 | ||||
| -rw-r--r-- | include/linux/netfilter/xt_IDLETIMER.h | 45 | ||||
| -rw-r--r-- | net/netfilter/Kconfig | 12 | ||||
| -rw-r--r-- | net/netfilter/Makefile | 1 | ||||
| -rw-r--r-- | net/netfilter/xt_IDLETIMER.c | 314 |
5 files changed, 373 insertions, 0 deletions
diff --git a/include/linux/netfilter/Kbuild b/include/linux/netfilter/Kbuild index 48767cd..bb103f4 100644 --- a/include/linux/netfilter/Kbuild +++ b/include/linux/netfilter/Kbuild @@ -8,6 +8,7 @@ header-y += xt_CONNMARK.h header-y += xt_CONNSECMARK.h header-y += xt_CT.h header-y += xt_DSCP.h +header-y += xt_IDLETIMER.h header-y += xt_LED.h header-y += xt_MARK.h header-y += xt_NFLOG.h diff --git a/include/linux/netfilter/xt_IDLETIMER.h b/include/linux/netfilter/xt_IDLETIMER.h new file mode 100644 index 0000000..3e1aa1b --- /dev/null +++ b/include/linux/netfilter/xt_IDLETIMER.h @@ -0,0 +1,45 @@ +/* + * linux/include/linux/netfilter/xt_IDLETIMER.h + * + * Header file for Xtables timer target module. + * + * 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_IDLETIMER_H +#define _XT_IDLETIMER_H + +#include <linux/types.h> + +#define MAX_IDLETIMER_LABEL_SIZE 28 + +struct idletimer_tg_info { + __u32 timeout; + + char label[MAX_IDLETIMER_LABEL_SIZE]; + + /* for kernel module internal use only */ + struct idletimer_tg *timer __attribute((aligned(8))); +}; + +#endif diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig index 8593a77..413ed24 100644 --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -424,6 +424,18 @@ config NETFILTER_XT_TARGET_HL since you can easily create immortal packets that loop forever on the network. +config NETFILTER_XT_TARGET_IDLETIMER + tristate "IDLETIMER target support" + depends on NETFILTER_ADVANCED + help + + This option adds the `IDLETIMER' 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. + + 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 14e3a8f..e28420a 100644 --- a/net/netfilter/Makefile +++ b/net/netfilter/Makefile @@ -61,6 +61,7 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_TCPMSS) += xt_TCPMSS.o obj-$(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-$(CONFIG_NETFILTER_XT_TARGET_IDLETIMER) += xt_IDLETIMER.o # matches obj-$(CONFIG_NETFILTER_XT_MATCH_CLUSTER) += xt_cluster.o diff --git a/net/netfilter/xt_IDLETIMER.c b/net/netfilter/xt_IDLETIMER.c new file mode 100644 index 0000000..e11090a --- /dev/null +++ b/net/netfilter/xt_IDLETIMER.c @@ -0,0 +1,314 @@ +/* + * 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/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; +} + +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"); +} + +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(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); +} + +static int idletimer_tg_create(struct idletimer_tg_info *info) +{ + int ret; + + info->timer = kmalloc(sizeof(*info->timer), GFP_KERNEL); + if (!info->timer) { + pr_debug("couldn't alloc timer\n"); + ret = -ENOMEM; + goto out; + } + + info->timer->attr.attr.name = kstrdup(info->label, GFP_KERNEL); + if (!info->timer->attr.attr.name) { + pr_debug("couldn't alloc attribute name\n"); + 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; +} + +/* + * 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; +} + +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; +} + +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); + 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), + .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; +} + +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); +} + +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"); |
