--- /dev/null
+/*
+ * linux/net/ipv4/netfilter/ipt_IDLETIMER.c
+ *
+ * Netfilter module to trigger a timer when packet matches.
+ * After timer expires a kevent will be sent.
+ *
+ * Copyright (C) 2004 Nokia Corporation. All rights reserved.
+ * Written by Timo Teras <ext-timo.teras@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
+ */
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/timer.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/notifier.h>
+#include <linux/netfilter.h>
+#include <linux/rtnetlink.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_ipv4/ipt_IDLETIMER.h>
+#include <linux/kobject.h>
+#include <linux/workqueue.h>
+
+#if 0
+#define DEBUGP(format, args...) printk("%s:%s:" format, \
+ __FILE__, __FUNCTION__ , ## args)
+#else
+#define DEBUGP(format, args...)
+#endif
+
+/*
+ * Internal timer management.
+ */
+static ssize_t utimer_attr_show(struct device *, struct device_attribute *attr, char *buf);
+static ssize_t utimer_attr_store(struct device *, struct device_attribute *attr,
+ const char *buf, size_t count);
+
+struct utimer_t {
+ char name[IFNAMSIZ];
+ struct list_head entry;
+ struct timer_list timer;
+ struct work_struct work;
+};
+
+static LIST_HEAD(active_utimer_head);
+static DEFINE_SPINLOCK(list_lock);
+static DEVICE_ATTR(idletimer, 0644, utimer_attr_show, utimer_attr_store);
+
+static void utimer_delete(struct utimer_t *timer)
+{
+ DEBUGP("Deleting timer '%s'\n", timer->name);
+
+ list_del(&timer->entry);
+ del_timer_sync(&timer->timer);
+ kfree(timer);
+}
+
+static void utimer_work(struct work_struct *work)
+{
+ struct utimer_t *timer = container_of(work, struct utimer_t, work);
+ struct net_device *netdev;
+
+ netdev = dev_get_by_name(&init_net, timer->name);
+
+ if (netdev != NULL) {
+ sysfs_notify(&netdev->dev.kobj, NULL,
+ "idletimer");
+ dev_put(netdev);
+ }
+}
+
+static void utimer_expired(unsigned long data)
+{
+ struct utimer_t *timer = (struct utimer_t *) data;
+
+ DEBUGP("Timer '%s' expired\n", timer->name);
+
+ spin_lock_bh(&list_lock);
+ utimer_delete(timer);
+ spin_unlock_bh(&list_lock);
+
+ schedule_work(&timer->work);
+}
+
+static struct utimer_t *utimer_create(const char *name)
+{
+ struct utimer_t *timer;
+
+ timer = kmalloc(sizeof(struct utimer_t), GFP_ATOMIC);
+ if (timer == NULL)
+ return NULL;
+
+ list_add(&timer->entry, &active_utimer_head);
+ strlcpy(timer->name, name, sizeof(timer->name));
+
+ init_timer(&timer->timer);
+ timer->timer.function = utimer_expired;
+ timer->timer.data = (unsigned long) timer;
+
+ INIT_WORK(&timer->work, utimer_work);
+
+ DEBUGP("Created timer '%s'\n", timer->name);
+
+ return timer;
+}
+
+static struct utimer_t *__utimer_find(const char *name)
+{
+ struct utimer_t *entry;
+
+ list_for_each_entry(entry, &active_utimer_head, entry) {
+ if (strcmp(name, entry->name) == 0) {
+ return entry;
+ }
+ }
+
+ return NULL;
+}
+
+static void utimer_modify(const char *name,
+ unsigned long expires)
+{
+ struct utimer_t *timer;
+
+ DEBUGP("Modifying timer '%s'\n", name);
+ spin_lock_bh(&list_lock);
+ timer = __utimer_find(name);
+ if (timer == NULL)
+ timer = utimer_create(name);
+ mod_timer(&timer->timer, expires);
+ spin_unlock_bh(&list_lock);
+}
+
+static ssize_t utimer_attr_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct utimer_t *timer;
+ unsigned long expires = 0;
+ struct net_device *netdev = container_of(dev, struct net_device, dev);
+
+ spin_lock_bh(&list_lock);
+ timer = __utimer_find(netdev->name);
+ if (timer)
+ expires = timer->timer.expires;
+ spin_unlock_bh(&list_lock);
+
+ if (expires)
+ return sprintf(buf, "%lu\n", (expires-jiffies) / HZ);
+
+ return sprintf(buf, "0\n");
+}
+
+static ssize_t utimer_attr_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int expires;
+ struct net_device *netdev = container_of(dev, struct net_device, dev);
+
+ if (sscanf(buf, "%d", &expires) == 1) {
+ if (expires > 0)
+ utimer_modify(netdev->name,
+ jiffies+HZ*(unsigned long)expires);
+ }
+
+ return count;
+}
+
+static int utimer_notifier_call(struct notifier_block *this,
+ unsigned long event, void *ptr)
+{
+ struct net_device *dev = ptr;
+ int ret = NOTIFY_DONE;
+
+ switch (event) {
+ case NETDEV_UP:
+ DEBUGP("NETDEV_UP: %s\n", dev->name);
+ ret = device_create_file(&dev->dev,
+ &dev_attr_idletimer);
+ break;
+ case NETDEV_DOWN:
+ DEBUGP("NETDEV_DOWN: %s\n", dev->name);
+ device_remove_file(&dev->dev,
+ &dev_attr_idletimer);
+ break;
+ }
+
+ return ret;
+}
+
+static struct notifier_block utimer_notifier_block = {
+ .notifier_call = utimer_notifier_call,
+};
+
+
+static int utimer_init(void)
+{
+ return register_netdevice_notifier(&utimer_notifier_block);
+}
+
+static void utimer_fini(void)
+{
+ struct utimer_t *entry, *next;
+ struct net_device *dev;
+
+ list_for_each_entry_safe(entry, next, &active_utimer_head, entry)
+ utimer_delete(entry);
+
+ rtnl_lock();
+ unregister_netdevice_notifier(&utimer_notifier_block);
+ for_each_netdev(&init_net, dev)
+ utimer_notifier_call(&utimer_notifier_block,
+ NETDEV_DOWN, dev);
+ rtnl_unlock();
+}
+
+/*
+ * The actual iptables plugin.
+ */
+static unsigned int ipt_idletimer_target(struct sk_buff *pskb,
+ const struct net_device *in,
+ const struct net_device *out,
+ unsigned int hooknum,
+ const struct xt_target *xttarget,
+ const void *targinfo)
+{
+ struct ipt_idletimer_info *target = (struct ipt_idletimer_info*) targinfo;
+ unsigned long expires;
+
+ expires = jiffies + HZ*target->timeout;
+
+ if (in != NULL)
+ utimer_modify(in->name, expires);
+
+ if (out != NULL)
+ utimer_modify(out->name, expires);
+
+ return XT_CONTINUE;
+}
+
+static bool ipt_idletimer_checkentry(const char *tablename,
+ const void *e,
+ const struct xt_target *target,
+ void *targinfo,
+ unsigned int hookmask)
+{
+ struct ipt_idletimer_info *info =
+ (struct ipt_idletimer_info *) targinfo;
+
+ if (info->timeout == 0) {
+ DEBUGP("timeout value is zero\n");
+ return 0;
+ }
+
+ return true;
+}
+
+static struct xt_target ipt_idletimer = {
+ .name = "IDLETIMER",
+ .target = ipt_idletimer_target,
+ .checkentry = ipt_idletimer_checkentry,
+ .me = THIS_MODULE,
+ .targetsize = sizeof(struct ipt_idletimer_info),
+};
+
+static int __init init(void)
+{
+ int ret;
+
+ ret = utimer_init();
+ if (ret)
+ return ret;
+
+ if (xt_register_target(&ipt_idletimer)) {
+ utimer_fini();
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void __exit fini(void)
+{
+ xt_unregister_target(&ipt_idletimer);
+ utimer_fini();
+}
+
+module_init(init);
+module_exit(fini);
+
+MODULE_AUTHOR("Timo Teras <ext-timo.teras@nokia.com>");
+MODULE_DESCRIPTION("iptables idletimer target module");
+MODULE_LICENSE("GPL");
projects / linux-2.6-omap-h63xx.git / blobdiff