/* 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.
 *
 * Authors:
 * (C) 2015 Pengutronix, Alexander Aring <aar@pengutronix.de>
 */

#include <linux/module.h>

#include <net/6lowpan.h>
#include <linux/if_arp.h>

#include "6lowpan_i.h"

int lowpan_register_netdevice(struct net_device *dev,
			      enum lowpan_lltypes lltype)
{
	int i, ret;

	dev->addr_len = EUI64_ADDR_LEN;
	dev->type = ARPHRD_6LOWPAN;
	dev->mtu = IPV6_MIN_MTU;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,3,0)
	dev->priv_flags |= IFF_NO_QUEUE;
#else
	dev->tx_queue_len = 0;
#endif

	lowpan_dev(dev)->lltype = lltype;

	spin_lock_init(&lowpan_dev(dev)->ctx.lock);
	for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++)
		lowpan_dev(dev)->ctx.table[i].id = i;

	ret = register_netdevice(dev);
	if (ret < 0)
		return ret;

	ret = lowpan_dev_debugfs_init(dev);
	if (ret < 0)
		unregister_netdevice(dev);

	return ret;
}
EXPORT_SYMBOL(lowpan_register_netdevice);

int lowpan_register_netdev(struct net_device *dev,
			   enum lowpan_lltypes lltype)
{
	int ret;

	rtnl_lock();
	ret = lowpan_register_netdevice(dev, lltype);
	rtnl_unlock();
	return ret;
}
EXPORT_SYMBOL(lowpan_register_netdev);

void lowpan_unregister_netdevice(struct net_device *dev)
{
	unregister_netdevice(dev);
	lowpan_dev_debugfs_exit(dev);
}
EXPORT_SYMBOL(lowpan_unregister_netdevice);

void lowpan_unregister_netdev(struct net_device *dev)
{
	rtnl_lock();
	lowpan_unregister_netdevice(dev);
	rtnl_unlock();
}
EXPORT_SYMBOL(lowpan_unregister_netdev);

static int lowpan_event(struct notifier_block *unused,
			unsigned long event, void *ptr)
{
	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
	int i;

	if (dev->type != ARPHRD_6LOWPAN)
		return NOTIFY_DONE;

	switch (event) {
	case NETDEV_DOWN:
		for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++)
			clear_bit(LOWPAN_IPHC_CTX_FLAG_ACTIVE,
				  &lowpan_dev(dev)->ctx.table[i].flags);
		break;
	default:
		return NOTIFY_DONE;
	}

	return NOTIFY_OK;
}

static struct notifier_block lowpan_notifier = {
	.notifier_call = lowpan_event,
};

static int __init lowpan_module_init(void)
{
	int ret;

	ret = lowpan_debugfs_init();
	if (ret < 0)
		return ret;

	ret = register_netdevice_notifier(&lowpan_notifier);
	if (ret < 0) {
		lowpan_debugfs_exit();
		return ret;
	}

	request_module_nowait("ipv6");

	request_module_nowait("nhc_dest");
	request_module_nowait("nhc_fragment");
	request_module_nowait("nhc_hop");
	request_module_nowait("nhc_ipv6");
	request_module_nowait("nhc_mobility");
	request_module_nowait("nhc_routing");
	request_module_nowait("nhc_udp");

	return 0;
}

static void __exit lowpan_module_exit(void)
{
	lowpan_debugfs_exit();
	unregister_netdevice_notifier(&lowpan_notifier);
}

module_init(lowpan_module_init);
module_exit(lowpan_module_exit);

MODULE_LICENSE("GPL");
