drivers/staging/batman-adv/hard-interface.c - maze/linux - Git at Google

 /*
  * Copyright (C) 2007-2009 B.A.T.M.A.N. contributors:
  *
  * Marek Lindner, Simon Wunderlich
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of version 2 of the GNU General Public
  * License 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 Street, Fifth Floor, Boston, MA
  * 02110-1301, USA
  *
  */

 #include "main.h"
 #include "hard-interface.h"
 #include "soft-interface.h"
 #include "send.h"
 #include "translation-table.h"
 #include "routing.h"
 #include "hash.h"

 #define MIN(x, y) ((x) < (y) ? (x) : (y))

 static char avail_ifs;
 static char active_ifs;

 static void hardif_free_interface(struct rcu_head *rcu);

 static struct batman_if *get_batman_if_by_name(char *name)
 {
 	struct batman_if *batman_if;

 	rcu_read_lock();
 	list_for_each_entry_rcu(batman_if, &if_list, list) {
 		if (strncmp(batman_if->dev, name, IFNAMSIZ) == 0)
 			goto out;
 	}

 	batman_if = NULL;

 out:
 	rcu_read_unlock();
 	return batman_if;
 }

 int hardif_min_mtu(void)
 {
 	struct batman_if *batman_if;
 	/* allow big frames if all devices are capable to do so
 	 * (have MTU > 1500 + BAT_HEADER_LEN) */
 	int min_mtu = ETH_DATA_LEN;

 	rcu_read_lock();
 	list_for_each_entry_rcu(batman_if, &if_list, list) {
 		if ((batman_if->if_active == IF_ACTIVE) ||
 		    (batman_if->if_active == IF_TO_BE_ACTIVATED))
 			min_mtu = MIN(batman_if->net_dev->mtu - BAT_HEADER_LEN,
 				      min_mtu);
 	}
 	rcu_read_unlock();

 	return min_mtu;
 }

 static void check_known_mac_addr(uint8_t *addr)
 {
 	struct batman_if *batman_if;

 	rcu_read_lock();
 	list_for_each_entry_rcu(batman_if, &if_list, list) {
 		if ((batman_if->if_active != IF_ACTIVE) &&
 		    (batman_if->if_active != IF_TO_BE_ACTIVATED))
 			continue;

 		if (!compare_orig(batman_if->net_dev->dev_addr, addr))
 			continue;

 		printk(KERN_WARNING "batman-adv:The newly added mac address (%pM) already exists on: %s\n",
 		       addr, batman_if->dev);
 		printk(KERN_WARNING "batman-adv:It is strongly recommended to keep mac addresses unique to avoid problems!\n");
 	}
 	rcu_read_unlock();
 }

 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
 void update_min_mtu(void)
 {
 	int min_mtu;

 	min_mtu = hardif_min_mtu();
 	if (soft_device->mtu != min_mtu)
 		soft_device->mtu = min_mtu;
 }

 /* checks if the interface is up. (returns 1 if it is) */
 static int hardif_is_interface_up(char *dev)
 {
 	struct net_device *net_dev;

 	/**
 	 * if we already have an interface in our interface list and
 	 * the current interface is not the primary interface and
 	 * the primary interface is not up and
 	 * the primary interface has never been up - don't activate any
 	 * secondary interface !
 	 */

 	rcu_read_lock();
 	if ((!list_empty(&if_list)) &&
 	    strncmp(((struct batman_if *)if_list.next)->dev, dev, IFNAMSIZ) &&
 	    !(((struct batman_if *)if_list.next)->if_active == IF_ACTIVE) &&
 	    !(((struct batman_if *)if_list.next)->if_active == IF_TO_BE_ACTIVATED) &&
 	    (!main_if_was_up())) {
 		rcu_read_unlock();
 		goto end;
 	}
 	rcu_read_unlock();

 #ifdef __NET_NET_NAMESPACE_H
 	net_dev = dev_get_by_name(&init_net, dev);
 #else
 	net_dev = dev_get_by_name(dev);
 #endif
 	if (!net_dev)
 		goto end;

 	if (!(net_dev->flags & IFF_UP))
 		goto failure;

 	dev_put(net_dev);
 	return 1;

 failure:
 	dev_put(net_dev);
 end:
 	return 0;
 }

 /* deactivates the interface. */
 void hardif_deactivate_interface(struct batman_if *batman_if)
 {
 	if (batman_if->if_active != IF_ACTIVE)
 		return;

 	/**
 	 * batman_if->net_dev has been acquired by dev_get_by_name() in
 	 * proc_interfaces_write() and has to be unreferenced.
 	 */

 	if (batman_if->net_dev)
 		dev_put(batman_if->net_dev);

 	batman_if->if_active = IF_INACTIVE;
 	active_ifs--;

 	printk(KERN_INFO "batman-adv:Interface deactivated: %s\n",
 		  batman_if->dev);
 }

 /* (re)activate given interface. */
 static void hardif_activate_interface(struct batman_if *batman_if)
 {
 	if (batman_if->if_active != IF_INACTIVE)
 		return;

 #ifdef __NET_NET_NAMESPACE_H
 	batman_if->net_dev = dev_get_by_name(&init_net, batman_if->dev);
 #else
 	batman_if->net_dev = dev_get_by_name(batman_if->dev);
 #endif
 	if (!batman_if->net_dev)
 		goto dev_err;

 	check_known_mac_addr(batman_if->net_dev->dev_addr);

 	addr_to_string(batman_if->addr_str, batman_if->net_dev->dev_addr);

 	memcpy(((struct batman_packet *)(batman_if->packet_buff))->orig,
 	       batman_if->net_dev->dev_addr, ETH_ALEN);
 	memcpy(((struct batman_packet *)(batman_if->packet_buff))->prev_sender,
 	       batman_if->net_dev->dev_addr, ETH_ALEN);

 	batman_if->if_active = IF_TO_BE_ACTIVATED;
 	active_ifs++;

 	/* save the mac address if it is our primary interface */
 	if (batman_if->if_num == 0)
 		set_main_if_addr(batman_if->net_dev->dev_addr);

 	printk(KERN_INFO "batman-adv:Interface activated: %s\n",
 		  batman_if->dev);

 	return;

 dev_err:
 	batman_if->net_dev = NULL;
 }

 static void hardif_free_interface(struct rcu_head *rcu)
 {
 	struct batman_if *batman_if = container_of(rcu, struct batman_if, rcu);

 	kfree(batman_if->packet_buff);
 	kfree(batman_if->dev);
 	kfree(batman_if);
 }

 /**
  * called by
  *  - echo '' > /proc/.../interfaces
  *  - modprobe -r batman-adv-core
  */
 /* removes and frees all interfaces */
 void hardif_remove_interfaces(void)
 {
 	struct batman_if *batman_if = NULL;

 	avail_ifs = 0;

 	/* no lock needed - we don't delete somewhere else */
 	list_for_each_entry(batman_if, &if_list, list) {

 		list_del_rcu(&batman_if->list);

 		/* first deactivate interface */
 		if (batman_if->if_active != IF_INACTIVE)
 			hardif_deactivate_interface(batman_if);

 		call_rcu(&batman_if->rcu, hardif_free_interface);
 	}
 }

 static int resize_orig(struct orig_node *orig_node, int if_num)
 {
 	void *data_ptr;

 	data_ptr = kmalloc((if_num + 1) * sizeof(TYPE_OF_WORD) * NUM_WORDS,
 			   GFP_ATOMIC);
 	if (!data_ptr) {
 		printk(KERN_ERR "batman-adv:Can't resize orig: out of memory\n");
 		return -1;
 	}

 	memcpy(data_ptr, orig_node->bcast_own,
 	       if_num * sizeof(TYPE_OF_WORD) * NUM_WORDS);
 	kfree(orig_node->bcast_own);
 	orig_node->bcast_own = data_ptr;

 	data_ptr = kmalloc((if_num + 1) * sizeof(uint8_t), GFP_ATOMIC);
 	if (!data_ptr) {
 		printk(KERN_ERR "batman-adv:Can't resize orig: out of memory\n");
 		return -1;
 	}

 	memcpy(data_ptr, orig_node->bcast_own_sum, if_num * sizeof(uint8_t));
 	kfree(orig_node->bcast_own_sum);
 	orig_node->bcast_own_sum = data_ptr;

 	return 0;
 }


 /* adds an interface the interface list and activate it, if possible */
 int hardif_add_interface(char *dev, int if_num)
 {
 	struct batman_if *batman_if;
 	struct batman_packet *batman_packet;
 	struct orig_node *orig_node;
 	unsigned long flags;
 	HASHIT(hashit);

 	batman_if = kmalloc(sizeof(struct batman_if), GFP_KERNEL);

 	if (!batman_if) {
 		printk(KERN_ERR "batman-adv:Can't add interface (%s): out of memory\n", dev);
 		return -1;
 	}

 	batman_if->net_dev = NULL;

 	if ((if_num == 0) && (num_hna > 0))
 		batman_if->packet_len = BAT_PACKET_LEN + num_hna * ETH_ALEN;
 	else
 		batman_if->packet_len = BAT_PACKET_LEN;

 	batman_if->packet_buff = kmalloc(batman_if->packet_len, GFP_KERNEL);

 	if (!batman_if->packet_buff) {
 		printk(KERN_ERR "batman-adv:Can't add interface packet (%s): out of memory\n", dev);
 		goto out;
 	}

 	batman_if->if_num = if_num;
 	batman_if->dev = dev;
 	batman_if->if_active = IF_INACTIVE;
 	INIT_RCU_HEAD(&batman_if->rcu);

 	printk(KERN_INFO "batman-adv:Adding interface: %s\n", dev);
 	avail_ifs++;

 	INIT_LIST_HEAD(&batman_if->list);

 	batman_packet = (struct batman_packet *)(batman_if->packet_buff);
 	batman_packet->packet_type = BAT_PACKET;
 	batman_packet->version = COMPAT_VERSION;
 	batman_packet->flags = 0x00;
 	batman_packet->ttl = (batman_if->if_num > 0 ? 2 : TTL);
 	batman_packet->flags = 0;
 	batman_packet->tq = TQ_MAX_VALUE;
 	batman_packet->num_hna = 0;

 	if (batman_if->packet_len != BAT_PACKET_LEN) {
 		unsigned char *hna_buff;
 		int hna_len;

 		hna_buff = batman_if->packet_buff + BAT_PACKET_LEN;
 		hna_len = batman_if->packet_len - BAT_PACKET_LEN;
 		batman_packet->num_hna = hna_local_fill_buffer(hna_buff,
 							       hna_len);
 	}

 	atomic_set(&batman_if->seqno, 1);

 	/* resize all orig nodes because orig_node->bcast_own(_sum) depend on
 	 * if_num */
 	spin_lock_irqsave(&orig_hash_lock, flags);

 	while (hash_iterate(orig_hash, &hashit)) {
 		orig_node = hashit.bucket->data;
 		if (resize_orig(orig_node, if_num) == -1) {
 			spin_unlock_irqrestore(&orig_hash_lock, flags);
 			goto out;
 		}
 	}

 	spin_unlock_irqrestore(&orig_hash_lock, flags);

 	if (!hardif_is_interface_up(batman_if->dev))
 		printk(KERN_ERR "batman-adv:Not using interface %s (retrying later): interface not active\n", batman_if->dev);
 	else
 		hardif_activate_interface(batman_if);

 	list_add_tail_rcu(&batman_if->list, &if_list);

 	/* begin sending originator messages on that interface */
 	schedule_own_packet(batman_if);
 	return 1;

 out:
 	kfree(batman_if->packet_buff);
 	kfree(batman_if);
 	kfree(dev);
 	return -1;
 }

 char hardif_get_active_if_num(void)
 {
 	return active_ifs;
 }

 static int hard_if_event(struct notifier_block *this,
 			    unsigned long event, void *ptr)
 {
 	struct net_device *dev = (struct net_device *)ptr;
 	struct batman_if *batman_if = get_batman_if_by_name(dev->name);

 	if (!batman_if)
 		goto out;

 	switch (event) {
 	case NETDEV_GOING_DOWN:
 	case NETDEV_DOWN:
 	case NETDEV_UNREGISTER:
 		hardif_deactivate_interface(batman_if);
 		break;
 	case NETDEV_UP:
 		hardif_activate_interface(batman_if);
 		if ((atomic_read(&module_state) == MODULE_INACTIVE) &&
 		    (hardif_get_active_if_num() > 0)) {
 			activate_module();
 		}
 		break;
 	/* NETDEV_CHANGEADDR - mac address change - what are we doing here ? */
 	default:
 		break;
 	};

 	update_min_mtu();

 out:
 	return NOTIFY_DONE;
 }

 /* find batman interface by netdev. assumes rcu_read_lock on */
 static struct batman_if *find_batman_if(struct net_device *dev)
 {
 	struct batman_if *batman_if;

 	rcu_read_lock();
 	list_for_each_entry_rcu(batman_if, &if_list, list) {
 		if (batman_if->net_dev == dev) {
 			rcu_read_unlock();
 			return batman_if;
 		}
 	}
 	rcu_read_unlock();
 	return NULL;
 }


 /* receive a packet with the batman ethertype coming on a hard
  * interface */
 int batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
 	struct packet_type *ptype, struct net_device *orig_dev)
 {
 	struct batman_packet *batman_packet;
 	struct batman_if *batman_if;
 	struct net_device_stats *stats;
 	int ret;

 	skb = skb_share_check(skb, GFP_ATOMIC);

 	/* skb was released by skb_share_check() */
 	if (!skb)
 		goto err_out;

 	if (atomic_read(&module_state) != MODULE_ACTIVE)
 		goto err_free;

 	/* packet should hold at least type and version */
 	if (unlikely(skb_headlen(skb) < 2))
 		goto err_free;

 	/* expect a valid ethernet header here. */
 	if (unlikely(skb->mac_len != sizeof(struct ethhdr)
 				|| !skb_mac_header(skb)))
 		goto err_free;

 	batman_if = find_batman_if(skb->dev);
 	if (!batman_if)
 		goto err_free;

 	/* discard frames on not active interfaces */
 	if (batman_if->if_active != IF_ACTIVE)
 		goto err_free;

 	stats = (struct net_device_stats *)dev_get_stats(skb->dev);
 	if (stats) {
 		stats->rx_packets++;
 		stats->rx_bytes += skb->len;
 	}

 	batman_packet = (struct batman_packet *)skb->data;

 	if (batman_packet->version != COMPAT_VERSION) {
 		bat_dbg(DBG_BATMAN,
 			"Drop packet: incompatible batman version (%i)\n",
 			batman_packet->version);
 		goto err_free;
 	}

 	/* all receive handlers return whether they received or reused
 	 * the supplied skb. if not, we have to free the skb. */

 	switch (batman_packet->packet_type) {
 		/* batman originator packet */
 	case BAT_PACKET:
 		ret = recv_bat_packet(skb, batman_if);
 		break;

 		/* batman icmp packet */
 	case BAT_ICMP:
 		ret = recv_icmp_packet(skb);
 		break;

 		/* unicast packet */
 	case BAT_UNICAST:
 		ret = recv_unicast_packet(skb);
 		break;

 		/* broadcast packet */
 	case BAT_BCAST:
 		ret = recv_bcast_packet(skb);
 		break;

 		/* vis packet */
 	case BAT_VIS:
 		ret = recv_vis_packet(skb);
 		break;
 	default:
 		ret = NET_RX_DROP;
 	}

 	if (ret == NET_RX_DROP)
 		kfree_skb(skb);

 	/* return NET_RX_SUCCESS in any case as we
 	 * most probably dropped the packet for
 	 * routing-logical reasons. */

 	return NET_RX_SUCCESS;

 err_free:
 	kfree_skb(skb);
 err_out:
 	return NET_RX_DROP;
 }


 struct notifier_block hard_if_notifier = {
 	.notifier_call = hard_if_event,
 };
	/*
	* Copyright (C) 2007-2009 B.A.T.M.A.N. contributors:
	*
	* Marek Lindner, Simon Wunderlich
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of version 2 of the GNU General Public
	* License 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 Street, Fifth Floor, Boston, MA
	* 02110-1301, USA
	*
	*/

	#include "main.h"
	#include "hard-interface.h"
	#include "soft-interface.h"
	#include "send.h"
	#include "translation-table.h"
	#include "routing.h"
	#include "hash.h"

	#define MIN(x, y) ((x) < (y) ? (x) : (y))

	static char avail_ifs;
	static char active_ifs;

	static void hardif_free_interface(struct rcu_head *rcu);

	static struct batman_if get_batman_if_by_name(char name)
	{
	struct batman_if *batman_if;

	rcu_read_lock();
	list_for_each_entry_rcu(batman_if, &if_list, list) {
	if (strncmp(batman_if->dev, name, IFNAMSIZ) == 0)
	goto out;
	}

	batman_if = NULL;

	out:
	rcu_read_unlock();
	return batman_if;
	}

	int hardif_min_mtu(void)
	{
	struct batman_if *batman_if;
	/* allow big frames if all devices are capable to do so
	* (have MTU > 1500 + BAT_HEADER_LEN) */
	int min_mtu = ETH_DATA_LEN;

	rcu_read_lock();
	list_for_each_entry_rcu(batman_if, &if_list, list) {
	if ((batman_if->if_active == IF_ACTIVE) \|\|
	(batman_if->if_active == IF_TO_BE_ACTIVATED))
	min_mtu = MIN(batman_if->net_dev->mtu - BAT_HEADER_LEN,
	min_mtu);
	}
	rcu_read_unlock();

	return min_mtu;
	}

	static void check_known_mac_addr(uint8_t *addr)
	{
	struct batman_if *batman_if;

	rcu_read_lock();
	list_for_each_entry_rcu(batman_if, &if_list, list) {
	if ((batman_if->if_active != IF_ACTIVE) &&
	(batman_if->if_active != IF_TO_BE_ACTIVATED))
	continue;

	if (!compare_orig(batman_if->net_dev->dev_addr, addr))
	continue;

	printk(KERN_WARNING "batman-adv:The newly added mac address (%pM) already exists on: %s\n",
	addr, batman_if->dev);
	printk(KERN_WARNING "batman-adv:It is strongly recommended to keep mac addresses unique to avoid problems!\n");
	}
	rcu_read_unlock();
	}

	/* adjusts the MTU if a new interface with a smaller MTU appeared. */
	void update_min_mtu(void)
	{
	int min_mtu;

	min_mtu = hardif_min_mtu();
	if (soft_device->mtu != min_mtu)
	soft_device->mtu = min_mtu;
	}

	/* checks if the interface is up. (returns 1 if it is) */
	static int hardif_is_interface_up(char *dev)
	{
	struct net_device *net_dev;

	/**
	* if we already have an interface in our interface list and
	* the current interface is not the primary interface and
	* the primary interface is not up and
	* the primary interface has never been up - don't activate any
	* secondary interface !
	*/

	rcu_read_lock();
	if ((!list_empty(&if_list)) &&
	strncmp(((struct batman_if *)if_list.next)->dev, dev, IFNAMSIZ) &&
	!(((struct batman_if *)if_list.next)->if_active == IF_ACTIVE) &&
	!(((struct batman_if *)if_list.next)->if_active == IF_TO_BE_ACTIVATED) &&
	(!main_if_was_up())) {
	rcu_read_unlock();
	goto end;
	}
	rcu_read_unlock();

	#ifdef __NET_NET_NAMESPACE_H
	net_dev = dev_get_by_name(&init_net, dev);
	#else
	net_dev = dev_get_by_name(dev);
	#endif
	if (!net_dev)
	goto end;

	if (!(net_dev->flags & IFF_UP))
	goto failure;

	dev_put(net_dev);
	return 1;

	failure:
	dev_put(net_dev);
	end:
	return 0;
	}

	/* deactivates the interface. */
	void hardif_deactivate_interface(struct batman_if *batman_if)
	{
	if (batman_if->if_active != IF_ACTIVE)
	return;

	/**
	* batman_if->net_dev has been acquired by dev_get_by_name() in
	* proc_interfaces_write() and has to be unreferenced.
	*/

	if (batman_if->net_dev)
	dev_put(batman_if->net_dev);

	batman_if->if_active = IF_INACTIVE;
	active_ifs--;

	printk(KERN_INFO "batman-adv:Interface deactivated: %s\n",
	batman_if->dev);
	}

	/* (re)activate given interface. */
	static void hardif_activate_interface(struct batman_if *batman_if)
	{
	if (batman_if->if_active != IF_INACTIVE)
	return;

	#ifdef __NET_NET_NAMESPACE_H
	batman_if->net_dev = dev_get_by_name(&init_net, batman_if->dev);
	#else
	batman_if->net_dev = dev_get_by_name(batman_if->dev);
	#endif
	if (!batman_if->net_dev)
	goto dev_err;

	check_known_mac_addr(batman_if->net_dev->dev_addr);

	addr_to_string(batman_if->addr_str, batman_if->net_dev->dev_addr);

	memcpy(((struct batman_packet *)(batman_if->packet_buff))->orig,
	batman_if->net_dev->dev_addr, ETH_ALEN);
	memcpy(((struct batman_packet *)(batman_if->packet_buff))->prev_sender,
	batman_if->net_dev->dev_addr, ETH_ALEN);

	batman_if->if_active = IF_TO_BE_ACTIVATED;
	active_ifs++;

	/* save the mac address if it is our primary interface */
	if (batman_if->if_num == 0)
	set_main_if_addr(batman_if->net_dev->dev_addr);

	printk(KERN_INFO "batman-adv:Interface activated: %s\n",
	batman_if->dev);

	return;

	dev_err:
	batman_if->net_dev = NULL;
	}

	static void hardif_free_interface(struct rcu_head *rcu)
	{
	struct batman_if *batman_if = container_of(rcu, struct batman_if, rcu);

	kfree(batman_if->packet_buff);
	kfree(batman_if->dev);
	kfree(batman_if);
	}

	/**
	* called by
	* - echo '' > /proc/.../interfaces
	* - modprobe -r batman-adv-core
	*/
	/* removes and frees all interfaces */
	void hardif_remove_interfaces(void)
	{
	struct batman_if *batman_if = NULL;

	avail_ifs = 0;

	/* no lock needed - we don't delete somewhere else */
	list_for_each_entry(batman_if, &if_list, list) {

	list_del_rcu(&batman_if->list);

	/* first deactivate interface */
	if (batman_if->if_active != IF_INACTIVE)
	hardif_deactivate_interface(batman_if);

	call_rcu(&batman_if->rcu, hardif_free_interface);
	}
	}

	static int resize_orig(struct orig_node *orig_node, int if_num)
	{
	void *data_ptr;

	data_ptr = kmalloc((if_num + 1) * sizeof(TYPE_OF_WORD) * NUM_WORDS,
	GFP_ATOMIC);
	if (!data_ptr) {
	printk(KERN_ERR "batman-adv:Can't resize orig: out of memory\n");
	return -1;
	}

	memcpy(data_ptr, orig_node->bcast_own,
	if_num * sizeof(TYPE_OF_WORD) * NUM_WORDS);
	kfree(orig_node->bcast_own);
	orig_node->bcast_own = data_ptr;

	data_ptr = kmalloc((if_num + 1) * sizeof(uint8_t), GFP_ATOMIC);
	if (!data_ptr) {
	printk(KERN_ERR "batman-adv:Can't resize orig: out of memory\n");
	return -1;
	}

	memcpy(data_ptr, orig_node->bcast_own_sum, if_num * sizeof(uint8_t));
	kfree(orig_node->bcast_own_sum);
	orig_node->bcast_own_sum = data_ptr;

	return 0;
	}


	/* adds an interface the interface list and activate it, if possible */
	int hardif_add_interface(char *dev, int if_num)
	{
	struct batman_if *batman_if;
	struct batman_packet *batman_packet;
	struct orig_node *orig_node;
	unsigned long flags;
	HASHIT(hashit);

	batman_if = kmalloc(sizeof(struct batman_if), GFP_KERNEL);

	if (!batman_if) {
	printk(KERN_ERR "batman-adv:Can't add interface (%s): out of memory\n", dev);
	return -1;
	}

	batman_if->net_dev = NULL;

	if ((if_num == 0) && (num_hna > 0))
	batman_if->packet_len = BAT_PACKET_LEN + num_hna * ETH_ALEN;
	else
	batman_if->packet_len = BAT_PACKET_LEN;

	batman_if->packet_buff = kmalloc(batman_if->packet_len, GFP_KERNEL);

	if (!batman_if->packet_buff) {
	printk(KERN_ERR "batman-adv:Can't add interface packet (%s): out of memory\n", dev);
	goto out;
	}

	batman_if->if_num = if_num;
	batman_if->dev = dev;
	batman_if->if_active = IF_INACTIVE;
	INIT_RCU_HEAD(&batman_if->rcu);

	printk(KERN_INFO "batman-adv:Adding interface: %s\n", dev);
	avail_ifs++;

	INIT_LIST_HEAD(&batman_if->list);

	batman_packet = (struct batman_packet *)(batman_if->packet_buff);
	batman_packet->packet_type = BAT_PACKET;
	batman_packet->version = COMPAT_VERSION;
	batman_packet->flags = 0x00;
	batman_packet->ttl = (batman_if->if_num > 0 ? 2 : TTL);
	batman_packet->flags = 0;
	batman_packet->tq = TQ_MAX_VALUE;
	batman_packet->num_hna = 0;

	if (batman_if->packet_len != BAT_PACKET_LEN) {
	unsigned char *hna_buff;
	int hna_len;

	hna_buff = batman_if->packet_buff + BAT_PACKET_LEN;
	hna_len = batman_if->packet_len - BAT_PACKET_LEN;
	batman_packet->num_hna = hna_local_fill_buffer(hna_buff,
	hna_len);
	}

	atomic_set(&batman_if->seqno, 1);

	/* resize all orig nodes because orig_node->bcast_own(_sum) depend on
	* if_num */
	spin_lock_irqsave(&orig_hash_lock, flags);

	while (hash_iterate(orig_hash, &hashit)) {
	orig_node = hashit.bucket->data;
	if (resize_orig(orig_node, if_num) == -1) {
	spin_unlock_irqrestore(&orig_hash_lock, flags);
	goto out;
	}
	}

	spin_unlock_irqrestore(&orig_hash_lock, flags);

	if (!hardif_is_interface_up(batman_if->dev))
	printk(KERN_ERR "batman-adv:Not using interface %s (retrying later): interface not active\n", batman_if->dev);
	else
	hardif_activate_interface(batman_if);

	list_add_tail_rcu(&batman_if->list, &if_list);

	/* begin sending originator messages on that interface */
	schedule_own_packet(batman_if);
	return 1;

	out:
	kfree(batman_if->packet_buff);
	kfree(batman_if);
	kfree(dev);
	return -1;
	}

	char hardif_get_active_if_num(void)
	{
	return active_ifs;
	}

	static int hard_if_event(struct notifier_block *this,
	unsigned long event, void *ptr)
	{
	struct net_device dev = (struct net_device )ptr;
	struct batman_if *batman_if = get_batman_if_by_name(dev->name);

	if (!batman_if)
	goto out;

	switch (event) {
	case NETDEV_GOING_DOWN:
	case NETDEV_DOWN:
	case NETDEV_UNREGISTER:
	hardif_deactivate_interface(batman_if);
	break;
	case NETDEV_UP:
	hardif_activate_interface(batman_if);
	if ((atomic_read(&module_state) == MODULE_INACTIVE) &&
	(hardif_get_active_if_num() > 0)) {
	activate_module();
	}
	break;
	/* NETDEV_CHANGEADDR - mac address change - what are we doing here ? */
	default:
	break;
	};

	update_min_mtu();

	out:
	return NOTIFY_DONE;
	}

	/* find batman interface by netdev. assumes rcu_read_lock on */
	static struct batman_if find_batman_if(struct net_device dev)
	{
	struct batman_if *batman_if;

	rcu_read_lock();
	list_for_each_entry_rcu(batman_if, &if_list, list) {
	if (batman_if->net_dev == dev) {
	rcu_read_unlock();
	return batman_if;
	}
	}
	rcu_read_unlock();
	return NULL;
	}


	/* receive a packet with the batman ethertype coming on a hard
	* interface */
	int batman_skb_recv(struct sk_buff skb, struct net_device dev,
	struct packet_type ptype, struct net_device orig_dev)
	{
	struct batman_packet *batman_packet;
	struct batman_if *batman_if;
	struct net_device_stats *stats;
	int ret;

	skb = skb_share_check(skb, GFP_ATOMIC);

	/* skb was released by skb_share_check() */
	if (!skb)
	goto err_out;

	if (atomic_read(&module_state) != MODULE_ACTIVE)
	goto err_free;

	/* packet should hold at least type and version */
	if (unlikely(skb_headlen(skb) < 2))
	goto err_free;

	/* expect a valid ethernet header here. */
	if (unlikely(skb->mac_len != sizeof(struct ethhdr)
	\|\| !skb_mac_header(skb)))
	goto err_free;

	batman_if = find_batman_if(skb->dev);
	if (!batman_if)
	goto err_free;

	/* discard frames on not active interfaces */
	if (batman_if->if_active != IF_ACTIVE)
	goto err_free;

	stats = (struct net_device_stats *)dev_get_stats(skb->dev);
	if (stats) {
	stats->rx_packets++;
	stats->rx_bytes += skb->len;
	}

	batman_packet = (struct batman_packet *)skb->data;

	if (batman_packet->version != COMPAT_VERSION) {
	bat_dbg(DBG_BATMAN,
	"Drop packet: incompatible batman version (%i)\n",
	batman_packet->version);
	goto err_free;
	}

	/* all receive handlers return whether they received or reused
	* the supplied skb. if not, we have to free the skb. */

	switch (batman_packet->packet_type) {
	/* batman originator packet */
	case BAT_PACKET:
	ret = recv_bat_packet(skb, batman_if);
	break;

	/* batman icmp packet */
	case BAT_ICMP:
	ret = recv_icmp_packet(skb);
	break;

	/* unicast packet */
	case BAT_UNICAST:
	ret = recv_unicast_packet(skb);
	break;

	/* broadcast packet */
	case BAT_BCAST:
	ret = recv_bcast_packet(skb);
	break;

	/* vis packet */
	case BAT_VIS:
	ret = recv_vis_packet(skb);
	break;
	default:
	ret = NET_RX_DROP;
	}

	if (ret == NET_RX_DROP)
	kfree_skb(skb);

	/* return NET_RX_SUCCESS in any case as we
	* most probably dropped the packet for
	* routing-logical reasons. */

	return NET_RX_SUCCESS;

	err_free:
	kfree_skb(skb);
	err_out:
	return NET_RX_DROP;
	}


	struct notifier_block hard_if_notifier = {
	.notifier_call = hard_if_event,
	};