text: /*
   * Copyright (C) 2007-2011 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 "routing.h"
  #include "send.h"
  #include "hash.h"
  #include "soft-interface.h"
  #include "hard-interface.h"
  #include "icmp_socket.h"
  #include "translation-table.h"
  #include "originator.h"
  #include "ring_buffer.h"
  #include "vis.h"
  #include "aggregation.h"
  #include "gateway_common.h"
  #include "gateway_client.h"
  #include "unicast.h"
  
  void slide_own_bcast_window(struct hard_iface *hard_iface)
  {
  	struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
  	struct hashtable_t *hash = bat_priv->orig_hash;
  	struct hlist_node *node;
  	struct hlist_head *head;
  	struct orig_node *orig_node;
  	unsigned long *word;
  	int i;
  	size_t word_index;
  
  	for (i = 0; i < hash->size; i++) {
  		head = &hash->table[i];
  
  		rcu_read_lock();
  		hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
  			spin_lock_bh(&orig_node->ogm_cnt_lock);
  			word_index = hard_iface->if_num * NUM_WORDS;
  			word = &(orig_node->bcast_own[word_index]);
  
  			bit_get_packet(bat_priv, word, 1, 0);
  			orig_node->bcast_own_sum[hard_iface->if_num] =
  				bit_packet_count(word);
  			spin_unlock_bh(&orig_node->ogm_cnt_lock);
  		}
  		rcu_read_unlock();
  	}
  }
  
  static void update_TT(struct bat_priv *bat_priv, struct orig_node *orig_node,
  		       unsigned char *tt_buff, int tt_buff_len)
  {
  	if ((tt_buff_len != orig_node->tt_buff_len) ||
  	    ((tt_buff_len > 0) &&
  	     (orig_node->tt_buff_len > 0) &&
  	     (memcmp(orig_node->tt_buff, tt_buff, tt_buff_len) != 0))) {
  
  		if (orig_node->tt_buff_len > 0)
  			tt_global_del_orig(bat_priv, orig_node,
  					    "originator changed tt");
  
  		if ((tt_buff_len > 0) && (tt_buff))
  			tt_global_add_orig(bat_priv, orig_node,
  					    tt_buff, tt_buff_len);
  	}
  }
  
  static void update_route(struct bat_priv *bat_priv,
  			 struct orig_node *orig_node,
  			 struct neigh_node *neigh_node,
  			 unsigned char *tt_buff, int tt_buff_len)
  {
  	struct neigh_node *curr_router;
  
  	curr_router = orig_node_get_router(orig_node);
  
  	/* route deleted */
  	if ((curr_router) && (!neigh_node)) {
  
  		bat_dbg(DBG_ROUTES, bat_priv, "Deleting route towards: %pM\n",
  			orig_node->orig);
  		tt_global_del_orig(bat_priv, orig_node,
  				    "originator timed out");
  
  	/* route added */
  	} else if ((!curr_router) && (neigh_node)) {
  
  		bat_dbg(DBG_ROUTES, bat_priv,
  			"Adding route towards: %pM (via %pM)\n",
  			orig_node->orig, neigh_node->addr);
  		tt_global_add_orig(bat_priv, orig_node,
  				    tt_buff, tt_buff_len);
  
  	/* route changed */
  	} else {
  		bat_dbg(DBG_ROUTES, bat_priv,
  			"Changing route towards: %pM "
  			"(now via %pM - was via %pM)\n",
  			orig_node->orig, neigh_node->addr,
  			curr_router->addr);
  	}
  
  	if (curr_router)
  		neigh_node_free_ref(curr_router);
  
  	/* increase refcount of new best neighbor */
  	if (neigh_node && !atomic_inc_not_zero(&neigh_node->refcount))
  		neigh_node = NULL;
  
  	spin_lock_bh(&orig_node->neigh_list_lock);
  	rcu_assign_pointer(orig_node->router, neigh_node);
  	spin_unlock_bh(&orig_node->neigh_list_lock);
  
  	/* decrease refcount of previous best neighbor */
  	if (curr_router)
  		neigh_node_free_ref(curr_router);
  }
  
  void update_routes(struct bat_priv *bat_priv, struct orig_node *orig_node,
  		   struct neigh_node *neigh_node, unsigned char *tt_buff,
  		   int tt_buff_len)
  {
  	struct neigh_node *router = NULL;
  
  	if (!orig_node)
  		goto out;
  
  	router = orig_node_get_router(orig_node);
  
  	if (router != neigh_node)
  		update_route(bat_priv, orig_node, neigh_node,
  			     tt_buff, tt_buff_len);
  	/* may be just TT changed */
  	else
  		update_TT(bat_priv, orig_node, tt_buff, tt_buff_len);
  
  out:
  	if (router)
  		neigh_node_free_ref(router);
  }
  
  static int is_bidirectional_neigh(struct orig_node *orig_node,
  				struct orig_node *orig_neigh_node,
  				struct batman_packet *batman_packet,
  				struct hard_iface *if_incoming)
  {
  	struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
  	struct neigh_node *neigh_node = NULL, *tmp_neigh_node;
  	struct hlist_node *node;
  	unsigned char total_count;
  	uint8_t orig_eq_count, neigh_rq_count, tq_own;
  	int tq_asym_penalty, ret = 0;
  
  	/* find corresponding one hop neighbor */
  	rcu_read_lock();
  	hlist_for_each_entry_rcu(tmp_neigh_node, node,
  				 &orig_neigh_node->neigh_list, list) {
  
  		if (!compare_eth(tmp_neigh_node->addr, orig_neigh_node->orig))
  			continue;
  
  		if (tmp_neigh_node->if_incoming != if_incoming)
  			continue;
  
  		if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
  			continue;
  
  		neigh_node = tmp_neigh_node;
  		break;
  	}
  	rcu_read_unlock();
  
  	if (!neigh_node)
  		neigh_node = create_neighbor(orig_neigh_node,
  					     orig_neigh_node,
  					     orig_neigh_node->orig,
  					     if_incoming);
  
  	if (!neigh_node)
  		goto out;
  
  	/* if orig_node is direct neighbour update neigh_node last_valid */
  	if (orig_node == orig_neigh_node)
  		neigh_node->last_valid = jiffies;
  
  	orig_node->last_valid = jiffies;
  
  	/* find packet count of corresponding one hop neighbor */
  	spin_lock_bh(&orig_node->ogm_cnt_lock);
  	orig_eq_count = orig_neigh_node->bcast_own_sum[if_incoming->if_num];
  	neigh_rq_count = neigh_node->real_packet_count;
  	spin_unlock_bh(&orig_node->ogm_cnt_lock);
  
  	/* pay attention to not get a value bigger than 100 % */
  	total_count = (orig_eq_count > neigh_rq_count ?
  		       neigh_rq_count : orig_eq_count);
  
  	/* if we have too few packets (too less data) we set tq_own to zero */
  	/* if we receive too few packets it is not considered bidirectional */
  	if ((total_count < TQ_LOCAL_BIDRECT_SEND_MINIMUM) ||
  	    (neigh_rq_count < TQ_LOCAL_BIDRECT_RECV_MINIMUM))
  		tq_own = 0;
  	else
  		/* neigh_node->real_packet_count is never zero as we
  		 * only purge old information when getting new
  		 * information */
  		tq_own = (TQ_MAX_VALUE * total_count) /	neigh_rq_count;
  
  	/*
  	 * 1 - ((1-x) ** 3), normalized to TQ_MAX_VALUE this does
  	 * affect the nearly-symmetric links only a little, but
  	 * punishes asymmetric links more.  This will give a value
  	 * between 0 and TQ_MAX_VALUE
  	 */
  	tq_asym_penalty = TQ_MAX_VALUE - (TQ_MAX_VALUE *
  				(TQ_LOCAL_WINDOW_SIZE - neigh_rq_count) *
  				(TQ_LOCAL_WINDOW_SIZE - neigh_rq_count) *
  				(TQ_LOCAL_WINDOW_SIZE - neigh_rq_count)) /
  					(TQ_LOCAL_WINDOW_SIZE *
  					 TQ_LOCAL_WINDOW_SIZE *
  					 TQ_LOCAL_WINDOW_SIZE);
  
  	batman_packet->tq = ((batman_packet->tq * tq_own * tq_asym_penalty) /
  						(TQ_MAX_VALUE * TQ_MAX_VALUE));
  
  	bat_dbg(DBG_BATMAN, bat_priv,
  		"bidirectional: "
  		"orig = %-15pM neigh = %-15pM => own_bcast = %2i, "
  		"real recv = %2i, local tq: %3i, asym_penalty: %3i, "
  		"total tq: %3i\n",
  		orig_node->orig, orig_neigh_node->orig, total_count,
  		neigh_rq_count, tq_own,	tq_asym_penalty, batman_packet->tq);
  
  	/* if link has the minimum required transmission quality
  	 * consider it bidirectional */
  	if (batman_packet->tq >= TQ_TOTAL_BIDRECT_LIMIT)
  		ret = 1;
  
  out:
  	if (neigh_node)
  		neigh_node_free_ref(neigh_node);
  	return ret;
  }
  
  /* caller must hold the neigh_list_lock */
  void bonding_candidate_del(struct orig_node *orig_node,
  			   struct neigh_node *neigh_node)
  {
  	/* this neighbor is not part of our candidate list */
  	if (list_empty(&neigh_node->bonding_list))
  		goto out;
  
  	list_del_rcu(&neigh_node->bonding_list);
  	INIT_LIST_HEAD(&neigh_node->bonding_list);
  	neigh_node_free_ref(neigh_node);
  	atomic_dec(&orig_node->bond_candidates);
  
  out:
  	return;
  }
  
  static void bonding_candidate_add(struct orig_node *orig_node,
  				  struct neigh_node *neigh_node)
  {
  	struct hlist_node *node;
  	struct neigh_node *tmp_neigh_node, *router = NULL;
  	uint8_t interference_candidate = 0;
  
  	spin_lock_bh(&orig_node->neigh_list_lock);
  
  	/* only consider if it has the same primary address ...  */
  	if (!compare_eth(orig_node->orig,
  			 neigh_node->orig_node->primary_addr))
  		goto candidate_del;
  
  	router = orig_node_get_router(orig_node);
  	if (!router)
  		goto candidate_del;
  
  	/* ... and is good enough to be considered */
  	if (neigh_node->tq_avg < router->tq_avg - BONDING_TQ_THRESHOLD)
  		goto candidate_del;
  
  	/**
  	 * check if we have another candidate with the same mac address or
  	 * interface. If we do, we won't select this candidate because of
  	 * possible interference.
  	 */
  	hlist_for_each_entry_rcu(tmp_neigh_node, node,
  				 &orig_node->neigh_list, list) {
  
  		if (tmp_neigh_node == neigh_node)
  			continue;
  
  		/* we only care if the other candidate is even
  		* considered as candidate. */
  		if (list_empty(&tmp_neigh_node->bonding_list))
  			continue;
  
  		if ((neigh_node->if_incoming == tmp_neigh_node->if_incoming) ||
  		    (compare_eth(neigh_node->addr, tmp_neigh_node->addr))) {
  			interference_candidate = 1;
  			break;
  		}
  	}
  
  	/* don't care further if it is an interference candidate */
  	if (interference_candidate)
  		goto candidate_del;
  
  	/* this neighbor already is part of our candidate list */
  	if (!list_empty(&neigh_node->bonding_list))
  		goto out;
  
  	if (!atomic_inc_not_zero(&neigh_node->refcount))
  		goto out;
  
  	list_add_rcu(&neigh_node->bonding_list, &orig_node->bond_list);
  	atomic_inc(&orig_node->bond_candidates);
  	goto out;
  
  candidate_del:
  	bonding_candidate_del(orig_node, neigh_node);
  
  out:
  	spin_unlock_bh(&orig_node->neigh_list_lock);
  
  	if (router)
  		neigh_node_free_ref(router);
  }
  
  /* copy primary address for bonding */
  static void bonding_save_primary(struct orig_node *orig_node,
  				 struct orig_node *orig_neigh_node,
  				 struct batman_packet *batman_packet)
  {
  	if (!(batman_packet->flags & PRIMARIES_FIRST_HOP))
  		return;
  
  	memcpy(orig_neigh_node->primary_addr, orig_node->orig, ETH_ALEN);
  }
  
  static void update_orig(struct bat_priv *bat_priv,
  			struct orig_node *orig_node,
  			struct ethhdr *ethhdr,
  			struct batman_packet *batman_packet,
  			struct hard_iface *if_incoming,
  			unsigned char *tt_buff, int tt_buff_len,
  			char is_duplicate)
  {
  	struct neigh_node *neigh_node = NULL, *tmp_neigh_node = NULL;
  	struct neigh_node *router = NULL;
  	struct orig_node *orig_node_tmp;
  	struct hlist_node *node;
  	int tmp_tt_buff_len;
  	uint8_t bcast_own_sum_orig, bcast_own_sum_neigh;
  
  	bat_dbg(DBG_BATMAN, bat_priv, "update_originator(): "
  		"Searching and updating originator entry of received packet\n");
  
  	rcu_read_lock();
  	hlist_for_each_entry_rcu(tmp_neigh_node, node,
  				 &orig_node->neigh_list, list) {
  		if (compare_eth(tmp_neigh_node->addr, ethhdr->h_source) &&
  		    (tmp_neigh_node->if_incoming == if_incoming) &&
  		     atomic_inc_not_zero(&tmp_neigh_node->refcount)) {
  			if (neigh_node)
  				neigh_node_free_ref(neigh_node);
  			neigh_node = tmp_neigh_node;
  			continue;
  		}
  
  		if (is_duplicate)
  			continue;
  
  		spin_lock_bh(&tmp_neigh_node->tq_lock);
  		ring_buffer_set(tmp_neigh_node->tq_recv,
  				&tmp_neigh_node->tq_index, 0);
  		tmp_neigh_node->tq_avg =
  			ring_buffer_avg(tmp_neigh_node->tq_recv);
  		spin_unlock_bh(&tmp_neigh_node->tq_lock);
  	}
  
  	if (!neigh_node) {
  		struct orig_node *orig_tmp;
  
  		orig_tmp = get_orig_node(bat_priv, ethhdr->h_source);
  		if (!orig_tmp)
  			goto unlock;
  
  		neigh_node = create_neighbor(orig_node, orig_tmp,
  					     ethhdr->h_source, if_incoming);
  
  		orig_node_free_ref(orig_tmp);
  		if (!neigh_node)
  			goto unlock;
  	} else
  		bat_dbg(DBG_BATMAN, bat_priv,
  			"Updating existing last-hop neighbor of originator\n");
  
  	rcu_read_unlock();
  
  	orig_node->flags = batman_packet->flags;
  	neigh_node->last_valid = jiffies;
  
  	spin_lock_bh(&neigh_node->tq_lock);
  	ring_buffer_set(neigh_node->tq_recv,
  			&neigh_node->tq_index,
  			batman_packet->tq);
  	neigh_node->tq_avg = ring_buffer_avg(neigh_node->tq_recv);
  	spin_unlock_bh(&neigh_node->tq_lock);
  
  	if (!is_duplicate) {
  		orig_node->last_ttl = batman_packet->ttl;
  		neigh_node->last_ttl = batman_packet->ttl;
  	}
  
  	bonding_candidate_add(orig_node, neigh_node);
  
  	tmp_tt_buff_len = (tt_buff_len > batman_packet->num_tt * ETH_ALEN ?
  			    batman_packet->num_tt * ETH_ALEN : tt_buff_len);
  
  	/* if this neighbor already is our next hop there is nothing
  	 * to change */
  	router = orig_node_get_router(orig_node);
  	if (router == neigh_node)
  		goto update_tt;
  
  	/* if this neighbor does not offer a better TQ we won't consider it */
  	if (router && (router->tq_avg > neigh_node->tq_avg))
  		goto update_tt;
  
  	/* if the TQ is the same and the link not more symetric we
  	 * won't consider it either */
  	if (router && (neigh_node->tq_avg == router->tq_avg)) {
  		orig_node_tmp = router->orig_node;
  		spin_lock_bh(&orig_node_tmp->ogm_cnt_lock);
  		bcast_own_sum_orig =
  			orig_node_tmp->bcast_own_sum[if_incoming->if_num];
  		spin_unlock_bh(&orig_node_tmp->ogm_cnt_lock);
  
  		orig_node_tmp = neigh_node->orig_node;
  		spin_lock_bh(&orig_node_tmp->ogm_cnt_lock);
  		bcast_own_sum_neigh =
  			orig_node_tmp->bcast_own_sum[if_incoming->if_num];
  		spin_unlock_bh(&orig_node_tmp->ogm_cnt_lock);
  
  		if (bcast_own_sum_orig >= bcast_own_sum_neigh)
  			goto update_tt;
  	}
  
  	update_routes(bat_priv, orig_node, neigh_node,
  		      tt_buff, tmp_tt_buff_len);
  	goto update_gw;
  
  update_tt:
  	update_routes(bat_priv, orig_node, router,
  		      tt_buff, tmp_tt_buff_len);
  
  update_gw:
  	if (orig_node->gw_flags != batman_packet->gw_flags)
  		gw_node_update(bat_priv, orig_node, batman_packet->gw_flags);
  
  	orig_node->gw_flags = batman_packet->gw_flags;
  
  	/* restart gateway selection if fast or late switching was enabled */
  	if ((orig_node->gw_flags) &&
  	    (atomic_read(&bat_priv->gw_mode) == GW_MODE_CLIENT) &&
  	    (atomic_read(&bat_priv->gw_sel_class) > 2))
  		gw_check_election(bat_priv, orig_node);
  
  	goto out;
  
  unlock:
  	rcu_read_unlock();
  out:
  	if (neigh_node)
  		neigh_node_free_ref(neigh_node);
  	if (router)
  		neigh_node_free_ref(router);
  }
  
  /* checks whether the host restarted and is in the protection time.
   * returns:
   *  0 if the packet is to be accepted
   *  1 if the packet is to be ignored.
   */
  static int window_protected(struct bat_priv *bat_priv,
  			    int32_t seq_num_diff,
  			    unsigned long *last_reset)
  {
  	if ((seq_num_diff <= -TQ_LOCAL_WINDOW_SIZE)
  		|| (seq_num_diff >= EXPECTED_SEQNO_RANGE)) {
  		if (time_after(jiffies, *last_reset +
  			msecs_to_jiffies(RESET_PROTECTION_MS))) {
  
  			*last_reset = jiffies;
  			bat_dbg(DBG_BATMAN, bat_priv,
  				"old packet received, start protection\n");
  
  			return 0;
  		} else
  			return 1;
  	}
  	return 0;
  }
  
  /* processes a batman packet for all interfaces, adjusts the sequence number and
   * finds out whether it is a duplicate.
   * returns:
   *   1 the packet is a duplicate
   *   0 the packet has not yet been received
   *  -1 the packet is old and has been received while the seqno window
   *     was protected. Caller should drop it.
   */
  static char count_real_packets(struct ethhdr *ethhdr,
  			       struct batman_packet *batman_packet,
  			       struct hard_iface *if_incoming)
  {
  	struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
  	struct orig_node *orig_node;
  	struct neigh_node *tmp_neigh_node;
  	struct hlist_node *node;
  	char is_duplicate = 0;
  	int32_t seq_diff;
  	int need_update = 0;
  	int set_mark, ret = -1;
  
  	orig_node = get_orig_node(bat_priv, batman_packet->orig);
  	if (!orig_node)
  		return 0;
  
  	spin_lock_bh(&orig_node->ogm_cnt_lock);
  	seq_diff = batman_packet->seqno - orig_node->last_real_seqno;
  
  	/* signalize caller that the packet is to be dropped. */
  	if (window_protected(bat_priv, seq_diff,
  			     &orig_node->batman_seqno_reset))
  		goto out;
  
  	rcu_read_lock();
  	hlist_for_each_entry_rcu(tmp_neigh_node, node,
  				 &orig_node->neigh_list, list) {
  
  		is_duplicate |= get_bit_status(tmp_neigh_node->real_bits,
  					       orig_node->last_real_seqno,
  					       batman_packet->seqno);
  
  		if (compare_eth(tmp_neigh_node->addr, ethhdr->h_source) &&
  		    (tmp_neigh_node->if_incoming == if_incoming))
  			set_mark = 1;
  		else
  			set_mark = 0;
  
  		/* if the window moved, set the update flag. */
  		need_update |= bit_get_packet(bat_priv,
  					      tmp_neigh_node->real_bits,
  					      seq_diff, set_mark);
  
  		tmp_neigh_node->real_packet_count =
  			bit_packet_count(tmp_neigh_node->real_bits);
  	}
  	rcu_read_unlock();
  
  	if (need_update) {
  		bat_dbg(DBG_BATMAN, bat_priv,
  			"updating last_seqno: old %d, new %d\n",
  			orig_node->last_real_seqno, batman_packet->seqno);
  		orig_node->last_real_seqno = batman_packet->seqno;
  	}
  
  	ret = is_duplicate;
  
  out:
  	spin_unlock_bh(&orig_node->ogm_cnt_lock);
  	orig_node_free_ref(orig_node);
  	return ret;
  }
  
  void receive_bat_packet(struct ethhdr *ethhdr,
  			struct batman_packet *batman_packet,
  			unsigned char *tt_buff, int tt_buff_len,
  			struct hard_iface *if_incoming)
  {
  	struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
  	struct hard_iface *hard_iface;
  	struct orig_node *orig_neigh_node, *orig_node;
  	struct neigh_node *router = NULL, *router_router = NULL;
  	struct neigh_node *orig_neigh_router = NULL;
  	char has_directlink_flag;
  	char is_my_addr = 0, is_my_orig = 0, is_my_oldorig = 0;
  	char is_broadcast = 0, is_bidirectional, is_single_hop_neigh;
  	char is_duplicate;
  	uint32_t if_incoming_seqno;
  
  	/* Silently drop when the batman packet is actually not a
  	 * correct packet.
  	 *
  	 * This might happen if a packet is padded (e.g. Ethernet has a
  	 * minimum frame length of 64 byte) and the aggregation interprets
  	 * it as an additional length.
  	 *
  	 * TODO: A more sane solution would be to have a bit in the
  	 * batman_packet to detect whether the packet is the last
  	 * packet in an aggregation.  Here we expect that the padding
  	 * is always zero (or not 0x01)
  	 */
  	if (batman_packet->packet_type != BAT_PACKET)
  		return;
  
  	/* could be changed by schedule_own_packet() */
  	if_incoming_seqno = atomic_read(&if_incoming->seqno);
  
  	has_directlink_flag = (batman_packet->flags & DIRECTLINK ? 1 : 0);
  
  	is_single_hop_neigh = (compare_eth(ethhdr->h_source,
  					   batman_packet->orig) ? 1 : 0);
  
  	bat_dbg(DBG_BATMAN, bat_priv,
  		"Received BATMAN packet via NB: %pM, IF: %s [%pM] "
  		"(from OG: %pM, via prev OG: %pM, seqno %d, tq %d, "
  		"TTL %d, V %d, IDF %d)\n",
  		ethhdr->h_source, if_incoming->net_dev->name,
  		if_incoming->net_dev->dev_addr, batman_packet->orig,
  		batman_packet->prev_sender, batman_packet->seqno,
  		batman_packet->tq, batman_packet->ttl, batman_packet->version,
  		has_directlink_flag);
  
  	rcu_read_lock();
  	list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
  		if (hard_iface->if_status != IF_ACTIVE)
  			continue;
  
  		if (hard_iface->soft_iface != if_incoming->soft_iface)
  			continue;
  
  		if (compare_eth(ethhdr->h_source,
  				hard_iface->net_dev->dev_addr))
  			is_my_addr = 1;
  
  		if (compare_eth(batman_packet->orig,
  				hard_iface->net_dev->dev_addr))
  			is_my_orig = 1;
  
  		if (compare_eth(batman_packet->prev_sender,
  				hard_iface->net_dev->dev_addr))
  			is_my_oldorig = 1;
  
  		if (compare_eth(ethhdr->h_source, broadcast_addr))
  			is_broadcast = 1;
  	}
  	rcu_read_unlock();
  
  	if (batman_packet->version != COMPAT_VERSION) {
  		bat_dbg(DBG_BATMAN, bat_priv,
  			"Drop packet: incompatible batman version (%i)\n",
  			batman_packet->version);
  		return;
  	}
  
  	if (is_my_addr) {
  		bat_dbg(DBG_BATMAN, bat_priv,
  			"Drop packet: received my own broadcast (sender: %pM"
  			")\n",
  			ethhdr->h_source);
  		return;
  	}
  
  	if (is_broadcast) {
  		bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: "
  		"ignoring all packets with broadcast source addr (sender: %pM"
  		")\n", ethhdr->h_source);
  		return;
  	}
  
  	if (is_my_orig) {
  		unsigned long *word;
  		int offset;
  
  		orig_neigh_node = get_orig_node(bat_priv, ethhdr->h_source);
  		if (!orig_neigh_node)
  			return;
  
  		/* neighbor has to indicate direct link and it has to
  		 * come via the corresponding interface */
  		/* if received seqno equals last send seqno save new
  		 * seqno for bidirectional check */
  		if (has_directlink_flag &&
  		    compare_eth(if_incoming->net_dev->dev_addr,
  				batman_packet->orig) &&
  		    (batman_packet->seqno - if_incoming_seqno + 2 == 0)) {
  			offset = if_incoming->if_num * NUM_WORDS;
  
  			spin_lock_bh(&orig_neigh_node->ogm_cnt_lock);
  			word = &(orig_neigh_node->bcast_own[offset]);
  			bit_mark(word, 0);
  			orig_neigh_node->bcast_own_sum[if_incoming->if_num] =
  				bit_packet_count(word);
  			spin_unlock_bh(&orig_neigh_node->ogm_cnt_lock);
  		}
  
  		bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: "
  			"originator packet from myself (via neighbor)\n");
  		orig_node_free_ref(orig_neigh_node);
  		return;
  	}
  
  	if (is_my_oldorig) {
  		bat_dbg(DBG_BATMAN, bat_priv,
  			"Drop packet: ignoring all rebroadcast echos (sender: "
  			"%pM)\n", ethhdr->h_source);
  		return;
  	}
  
  	orig_node = get_orig_node(bat_priv, batman_packet->orig);
  	if (!orig_node)
  		return;
  
  	is_duplicate = count_real_packets(ethhdr, batman_packet, if_incoming);
  
  	if (is_duplicate == -1) {
  		bat_dbg(DBG_BATMAN, bat_priv,
  			"Drop packet: packet within seqno protection time "
  			"(sender: %pM)\n", ethhdr->h_source);
  		goto out;
  	}
  
  	if (batman_packet->tq == 0) {
  		bat_dbg(DBG_BATMAN, bat_priv,
  			"Drop packet: originator packet with tq equal 0\n");
  		goto out;
  	}
  
  	router = orig_node_get_router(orig_node);
  	if (router)
  		router_router = orig_node_get_router(router->orig_node);
  
  	/* avoid temporary routing loops */
  	if (router && router_router &&
  	    (compare_eth(router->addr, batman_packet->prev_sender)) &&
  	    !(compare_eth(batman_packet->orig, batman_packet->prev_sender)) &&
  	    (compare_eth(router->addr, router_router->addr))) {
  		bat_dbg(DBG_BATMAN, bat_priv,
  			"Drop packet: ignoring all rebroadcast packets that "
  			"may make me loop (sender: %pM)\n", ethhdr->h_source);
  		goto out;
  	}
  
  	/* if sender is a direct neighbor the sender mac equals
  	 * originator mac */
  	orig_neigh_node = (is_single_hop_neigh ?
  			   orig_node :
  			   get_orig_node(bat_priv, ethhdr->h_source));
  	if (!orig_neigh_node)
  		goto out;
  
  	orig_neigh_router = orig_node_get_router(orig_neigh_node);
  
  	/* drop packet if sender is not a direct neighbor and if we
  	 * don't route towards it */
  	if (!is_single_hop_neigh && (!orig_neigh_router)) {
  		bat_dbg(DBG_BATMAN, bat_priv,
  			"Drop packet: OGM via unknown neighbor!\n");
  		goto out_neigh;
  	}
  
  	is_bidirectional = is_bidirectional_neigh(orig_node, orig_neigh_node,
  						batman_packet, if_incoming);
  
  	bonding_save_primary(orig_node, orig_neigh_node, batman_packet);
  
  	/* update ranking if it is not a duplicate or has the same
  	 * seqno and similar ttl as the non-duplicate */
  	if (is_bidirectional &&
  	    (!is_duplicate ||
  	     ((orig_node->last_real_seqno == batman_packet->seqno) &&
  	      (orig_node->last_ttl - 3 <= batman_packet->ttl))))
  		update_orig(bat_priv, orig_node, ethhdr, batman_packet,
  			    if_incoming, tt_buff, tt_buff_len, is_duplicate);
  
  	/* is single hop (direct) neighbor */
  	if (is_single_hop_neigh) {
  
  		/* mark direct link on incoming interface */
  		schedule_forward_packet(orig_node, ethhdr, batman_packet,
  					1, tt_buff_len, if_incoming);
  
  		bat_dbg(DBG_BATMAN, bat_priv, "Forwarding packet: "
  			"rebroadcast neighbor packet with direct link flag\n");
  		goto out_neigh;
  	}
  
  	/* multihop originator */
  	if (!is_bidirectional) {
  		bat_dbg(DBG_BATMAN, bat_priv,
  			"Drop packet: not received via bidirectional link\n");
  		goto out_neigh;
  	}
  
  	if (is_duplicate) {
  		bat_dbg(DBG_BATMAN, bat_priv,
  			"Drop packet: duplicate packet received\n");
  		goto out_neigh;
  	}
  
  	bat_dbg(DBG_BATMAN, bat_priv,
  		"Forwarding packet: rebroadcast originator packet\n");
  	schedule_forward_packet(orig_node, ethhdr, batman_packet,
  				0, tt_buff_len, if_incoming);
  
  out_neigh:
  	if ((orig_neigh_node) && (!is_single_hop_neigh))
  		orig_node_free_ref(orig_neigh_node);
  out:
  	if (router)
  		neigh_node_free_ref(router);
  	if (router_router)
  		neigh_node_free_ref(router_router);
  	if (orig_neigh_router)
  		neigh_node_free_ref(orig_neigh_router);
  
  	orig_node_free_ref(orig_node);
  }
  
  int recv_bat_packet(struct sk_buff *skb, struct hard_iface *hard_iface)
  {
  	struct ethhdr *ethhdr;
  
  	/* drop packet if it has not necessary minimum size */
  	if (unlikely(!pskb_may_pull(skb, sizeof(struct batman_packet))))
  		return NET_RX_DROP;
  
  	ethhdr = (struct ethhdr *)skb_mac_header(skb);
  
  	/* packet with broadcast indication but unicast recipient */
  	if (!is_broadcast_ether_addr(ethhdr->h_dest))
  		return NET_RX_DROP;
  
  	/* packet with broadcast sender address */
  	if (is_broadcast_ether_addr(ethhdr->h_source))
  		return NET_RX_DROP;
  
  	/* create a copy of the skb, if needed, to modify it. */
  	if (skb_cow(skb, 0) < 0)
  		return NET_RX_DROP;
  
  	/* keep skb linear */
  	if (skb_linearize(skb) < 0)
  		return NET_RX_DROP;
  
  	ethhdr = (struct ethhdr *)skb_mac_header(skb);
  
  	receive_aggr_bat_packet(ethhdr,
  				skb->data,
  				skb_headlen(skb),
  				hard_iface);
  
  	kfree_skb(skb);
  	return NET_RX_SUCCESS;
  }
  
  static int recv_my_icmp_packet(struct bat_priv *bat_priv,
  			       struct sk_buff *skb, size_t icmp_len)
  {
  	struct hard_iface *primary_if = NULL;
  	struct orig_node *orig_node = NULL;
  	struct neigh_node *router = NULL;
  	struct icmp_packet_rr *icmp_packet;
  	int ret = NET_RX_DROP;
  
  	icmp_packet = (struct icmp_packet_rr *)skb->data;
  
  	/* add data to device queue */
  	if (icmp_packet->msg_type != ECHO_REQUEST) {
  		bat_socket_receive_packet(icmp_packet, icmp_len);
  		goto out;
  	}
  
  	primary_if = primary_if_get_selected(bat_priv);
  	if (!primary_if)
  		goto out;
  
  	/* answer echo request (ping) */
  	/* get routing information */
  	orig_node = orig_hash_find(bat_priv, icmp_packet->orig);
  	if (!orig_node)
  		goto out;
  
  	router = orig_node_get_router(orig_node);
  	if (!router)
  		goto out;
  
  	/* create a copy of the skb, if needed, to modify it. */
  	if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
  		goto out;
  
  	icmp_packet = (struct icmp_packet_rr *)skb->data;
  
  	memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
  	memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
  	icmp_packet->msg_type = ECHO_REPLY;
  	icmp_packet->ttl = TTL;
  
  	send_skb_packet(skb, router->if_incoming, router->addr);
  	ret = NET_RX_SUCCESS;
  
  out:
  	if (primary_if)
  		hardif_free_ref(primary_if);
  	if (router)
  		neigh_node_free_ref(router);
  	if (orig_node)
  		orig_node_free_ref(orig_node);
  	return ret;
  }
  
  static int recv_icmp_ttl_exceeded(struct bat_priv *bat_priv,
  				  struct sk_buff *skb)
  {
  	struct hard_iface *primary_if = NULL;
  	struct orig_node *orig_node = NULL;
  	struct neigh_node *router = NULL;
  	struct icmp_packet *icmp_packet;
  	int ret = NET_RX_DROP;
  
  	icmp_packet = (struct icmp_packet *)skb->data;
  
  	/* send TTL exceeded if packet is an echo request (traceroute) */
  	if (icmp_packet->msg_type != ECHO_REQUEST) {
  		pr_debug("Warning - can't forward icmp packet from %pM to "
  			 "%pM: ttl exceeded\n", icmp_packet->orig,
  			 icmp_packet->dst);
  		goto out;
  	}
  
  	primary_if = primary_if_get_selected(bat_priv);
  	if (!primary_if)
  		goto out;
  
  	/* get routing information */
  	orig_node = orig_hash_find(bat_priv, icmp_packet->orig);
  	if (!orig_node)
  		goto out;
  
  	router = orig_node_get_router(orig_node);
  	if (!router)
  		goto out;
  
  	/* create a copy of the skb, if needed, to modify it. */
  	if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
  		goto out;
  
  	icmp_packet = (struct icmp_packet *)skb->data;
  
  	memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
  	memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
  	icmp_packet->msg_type = TTL_EXCEEDED;
  	icmp_packet->ttl = TTL;
  
  	send_skb_packet(skb, router->if_incoming, router->addr);
  	ret = NET_RX_SUCCESS;
  
  out:
  	if (primary_if)
  		hardif_free_ref(primary_if);
  	if (router)
  		neigh_node_free_ref(router);
  	if (orig_node)
  		orig_node_free_ref(orig_node);
  	return ret;
  }
  
  int recv_icmp_packet(struct sk_buff *skb, struct hard_iface *recv_if)
  {
  	struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
  	struct icmp_packet_rr *icmp_packet;
  	struct ethhdr *ethhdr;
  	struct orig_node *orig_node = NULL;
  	struct neigh_node *router = NULL;
  	int hdr_size = sizeof(struct icmp_packet);
  	int ret = NET_RX_DROP;
  
  	/**
  	 * we truncate all incoming icmp packets if they don't match our size
  	 */
  	if (skb->len >= sizeof(struct icmp_packet_rr))
  		hdr_size = sizeof(struct icmp_packet_rr);
  
  	/* drop packet if it has not necessary minimum size */
  	if (unlikely(!pskb_may_pull(skb, hdr_size)))
  		goto out;
  
  	ethhdr = (struct ethhdr *)skb_mac_header(skb);
  
  	/* packet with unicast indication but broadcast recipient */
  	if (is_broadcast_ether_addr(ethhdr->h_dest))
  		goto out;
  
  	/* packet with broadcast sender address */
  	if (is_broadcast_ether_addr(ethhdr->h_source))
  		goto out;
  
  	/* not for me */
  	if (!is_my_mac(ethhdr->h_dest))
  		goto out;
  
  	icmp_packet = (struct icmp_packet_rr *)skb->data;
  
  	/* add record route information if not full */
  	if ((hdr_size == sizeof(struct icmp_packet_rr)) &&
  	    (icmp_packet->rr_cur < BAT_RR_LEN)) {
  		memcpy(&(icmp_packet->rr[icmp_packet->rr_cur]),
  			ethhdr->h_dest, ETH_ALEN);
  		icmp_packet->rr_cur++;
  	}
  
  	/* packet for me */
  	if (is_my_mac(icmp_packet->dst))
  		return recv_my_icmp_packet(bat_priv, skb, hdr_size);
  
  	/* TTL exceeded */
  	if (icmp_packet->ttl < 2)
  		return recv_icmp_ttl_exceeded(bat_priv, skb);
  
  	/* get routing information */
  	orig_node = orig_hash_find(bat_priv, icmp_packet->dst);
  	if (!orig_node)
  		goto out;
  
  	router = orig_node_get_router(orig_node);
  	if (!router)
  		goto out;
  
  	/* create a copy of the skb, if needed, to modify it. */
  	if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
  		goto out;
  
  	icmp_packet = (struct icmp_packet_rr *)skb->data;
  
  	/* decrement ttl */
  	icmp_packet->ttl--;
  
  	/* route it */
  	send_skb_packet(skb, router->if_incoming, router->addr);
  	ret = NET_RX_SUCCESS;
  
  out:
  	if (router)
  		neigh_node_free_ref(router);
  	if (orig_node)
  		orig_node_free_ref(orig_node);
  	return ret;
  }
  
  /* In the bonding case, send the packets in a round
   * robin fashion over the remaining interfaces.
   *
   * This method rotates the bonding list and increases the
   * returned router's refcount. */
  static struct neigh_node *find_bond_router(struct orig_node *primary_orig,
  					   struct hard_iface *recv_if)
  {
  	struct neigh_node *tmp_neigh_node;
  	struct neigh_node *router = NULL, *first_candidate = NULL;
  
  	rcu_read_lock();
  	list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
  				bonding_list) {
  		if (!first_candidate)
  			first_candidate = tmp_neigh_node;
  
  		/* recv_if == NULL on the first node. */
  		if (tmp_neigh_node->if_incoming == recv_if)
  			continue;
  
  		if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
  			continue;
  
  		router = tmp_neigh_node;
  		break;
  	}
  
  	/* use the first candidate if nothing was found. */
  	if (!router && first_candidate &&
  	    atomic_inc_not_zero(&first_candidate->refcount))
  		router = first_candidate;
  
  	if (!router)
  		goto out;
  
  	/* selected should point to the next element
  	 * after the current router */
  	spin_lock_bh(&primary_orig->neigh_list_lock);
  	/* this is a list_move(), which unfortunately
  	 * does not exist as rcu version */
  	list_del_rcu(&primary_orig->bond_list);
  	list_add_rcu(&primary_orig->bond_list,
  		     &router->bonding_list);
  	spin_unlock_bh(&primary_orig->neigh_list_lock);
  
  out:
  	rcu_read_unlock();
  	return router;
  }
  
  /* Interface Alternating: Use the best of the
   * remaining candidates which are not using
   * this interface.
   *
   * Increases the returned router's refcount */
  static struct neigh_node *find_ifalter_router(struct orig_node *primary_orig,
  					      struct hard_iface *recv_if)
  {
  	struct neigh_node *tmp_neigh_node;
  	struct neigh_node *router = NULL, *first_candidate = NULL;
  
  	rcu_read_lock();
  	list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
  				bonding_list) {
  		if (!first_candidate)
  			first_candidate = tmp_neigh_node;
  
  		/* recv_if == NULL on the first node. */
  		if (tmp_neigh_node->if_incoming == recv_if)
  			continue;
  
  		if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
  			continue;
  
  		/* if we don't have a router yet
  		 * or this one is better, choose it. */
  		if ((!router) ||
  		    (tmp_neigh_node->tq_avg > router->tq_avg)) {
  			/* decrement refcount of
  			 * previously selected router */
  			if (router)
  				neigh_node_free_ref(router);
  
  			router = tmp_neigh_node;
  			atomic_inc_not_zero(&router->refcount);
  		}
  
  		neigh_node_free_ref(tmp_neigh_node);
  	}
  
  	/* use the first candidate if nothing was found. */
  	if (!router && first_candidate &&
  	    atomic_inc_not_zero(&first_candidate->refcount))
  		router = first_candidate;
  
  	rcu_read_unlock();
  	return router;
  }
  
  /* find a suitable router for this originator, and use
   * bonding if possible. increases the found neighbors
   * refcount.*/
  struct neigh_node *find_router(struct bat_priv *bat_priv,
  			       struct orig_node *orig_node,
  			       struct hard_iface *recv_if)
  {
  	struct orig_node *primary_orig_node;
  	struct orig_node *router_orig;
  	struct neigh_node *router;
  	static uint8_t zero_mac[ETH_ALEN] = {0, 0, 0, 0, 0, 0};
  	int bonding_enabled;
  
  	if (!orig_node)
  		return NULL;
  
  	router = orig_node_get_router(orig_node);
  	if (!router)
  		goto err;
  
  	/* without bonding, the first node should
  	 * always choose the default router. */
  	bonding_enabled = atomic_read(&bat_priv->bonding);
  
  	rcu_read_lock();
  	/* select default router to output */
  	router_orig = router->orig_node;
  	if (!router_orig)
  		goto err_unlock;
  
  	if ((!recv_if) && (!bonding_enabled))
  		goto return_router;
  
  	/* if we have something in the primary_addr, we can search
  	 * for a potential bonding candidate. */
  	if (compare_eth(router_orig->primary_addr, zero_mac))
  		goto return_router;
  
  	/* find the orig_node which has the primary interface. might
  	 * even be the same as our router_orig in many cases */
  
  	if (compare_eth(router_orig->primary_addr, router_orig->orig)) {
  		primary_orig_node = router_orig;
  	} else {
  		primary_orig_node = orig_hash_find(bat_priv,
  						   router_orig->primary_addr);
  		if (!primary_orig_node)
  			goto return_router;
  
  		orig_node_free_ref(primary_orig_node);
  	}
  
  	/* with less than 2 candidates, we can't do any
  	 * bonding and prefer the original router. */
  	if (atomic_read(&primary_orig_node->bond_candidates) < 2)
  		goto return_router;
  
  	/* all nodes between should choose a candidate which
  	 * is is not on the interface where the packet came
  	 * in. */
  
  	neigh_node_free_ref(router);
  
  	if (bonding_enabled)
  		router = find_bond_router(primary_orig_node, recv_if);
  	else
  		router = find_ifalter_router(primary_orig_node, recv_if);
  
  return_router:
  	rcu_read_unlock();
  	return router;
  err_unlock:
  	rcu_read_unlock();
  err:
  	if (router)
  		neigh_node_free_ref(router);
  	return NULL;
  }
  
  static int check_unicast_packet(struct sk_buff *skb, int hdr_size)
  {
  	struct ethhdr *ethhdr;
  
  	/* drop packet if it has not necessary minimum size */
  	if (unlikely(!pskb_may_pull(skb, hdr_size)))
  		return -1;
  
  	ethhdr = (struct ethhdr *)skb_mac_header(skb);
  
  	/* packet with unicast indication but broadcast recipient */
  	if (is_broadcast_ether_addr(ethhdr->h_dest))
  		return -1;
  
  	/* packet with broadcast sender address */
  	if (is_broadcast_ether_addr(ethhdr->h_source))
  		return -1;
  
  	/* not for me */
  	if (!is_my_mac(ethhdr->h_dest))
  		return -1;
  
  	return 0;
  }
  
  int route_unicast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
  {
  	struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
  	struct orig_node *orig_node = NULL;
  	struct neigh_node *neigh_node = NULL;
  	struct unicast_packet *unicast_packet;
  	struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb);
  	int ret = NET_RX_DROP;
  	struct sk_buff *new_skb;
  
  	unicast_packet = (struct unicast_packet *)skb->data;
  
  	/* TTL exceeded */
  	if (unicast_packet->ttl < 2) {
  		pr_debug("Warning - can't forward unicast packet from %pM to "
  			 "%pM: ttl exceeded\n", ethhdr->h_source,
  			 unicast_packet->dest);
  		goto out;
  	}
  
  	/* get routing information */
  	orig_node = orig_hash_find(bat_priv, unicast_packet->dest);
  
  	if (!orig_node)
  		goto out;
  
  	/* find_router() increases neigh_nodes refcount if found. */
  	neigh_node = find_router(bat_priv, orig_node, recv_if);
  
  	if (!neigh_node)
  		goto out;
  
  	/* create a copy of the skb, if needed, to modify it. */
  	if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
  		goto out;
  
  	unicast_packet = (struct unicast_packet *)skb->data;
  
  	if (unicast_packet->packet_type == BAT_UNICAST &&
  	    atomic_read(&bat_priv->fragmentation) &&
  	    skb->len > neigh_node->if_incoming->net_dev->mtu) {
  		ret = frag_send_skb(skb, bat_priv,
  				    neigh_node->if_incoming, neigh_node->addr);
  		goto out;
  	}
  
  	if (unicast_packet->packet_type == BAT_UNICAST_FRAG &&
  	    frag_can_reassemble(skb, neigh_node->if_incoming->net_dev->mtu)) {
  
  		ret = frag_reassemble_skb(skb, bat_priv, &new_skb);
  
  		if (ret == NET_RX_DROP)
  			goto out;
  
  		/* packet was buffered for late merge */
  		if (!new_skb) {
  			ret = NET_RX_SUCCESS;
  			goto out;
  		}
  
  		skb = new_skb;
  		unicast_packet = (struct unicast_packet *)skb->data;
  	}
  
  	/* decrement ttl */
  	unicast_packet->ttl--;
  
  	/* route it */
  	send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
  	ret = NET_RX_SUCCESS;
  
  out:
  	if (neigh_node)
  		neigh_node_free_ref(neigh_node);
  	if (orig_node)
  		orig_node_free_ref(orig_node);
  	return ret;
  }
  
  int recv_unicast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
  {
  	struct unicast_packet *unicast_packet;
  	int hdr_size = sizeof(struct unicast_packet);
  
  	if (check_unicast_packet(skb, hdr_size) < 0)
  		return NET_RX_DROP;
  
  	unicast_packet = (struct unicast_packet *)skb->data;
  
  	/* packet for me */
  	if (is_my_mac(unicast_packet->dest)) {
  		interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
  		return NET_RX_SUCCESS;
  	}
  
  	return route_unicast_packet(skb, recv_if);
  }
  
  int recv_ucast_frag_packet(struct sk_buff *skb, struct hard_iface *recv_if)
  {
  	struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
  	struct unicast_frag_packet *unicast_packet;
  	int hdr_size = sizeof(struct unicast_frag_packet);
  	struct sk_buff *new_skb = NULL;
  	int ret;
  
  	if (check_unicast_packet(skb, hdr_size) < 0)
  		return NET_RX_DROP;
  
  	unicast_packet = (struct unicast_frag_packet *)skb->data;
  
  	/* packet for me */
  	if (is_my_mac(unicast_packet->dest)) {
  
  		ret = frag_reassemble_skb(skb, bat_priv, &new_skb);
  
  		if (ret == NET_RX_DROP)
  			return NET_RX_DROP;
  
  		/* packet was buffered for late merge */
  		if (!new_skb)
  			return NET_RX_SUCCESS;
  
  		interface_rx(recv_if->soft_iface, new_skb, recv_if,
  			     sizeof(struct unicast_packet));
  		return NET_RX_SUCCESS;
  	}
  
  	return route_unicast_packet(skb, recv_if);
  }
  
  int recv_bcast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
  {
  	struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
  	struct orig_node *orig_node = NULL;
  	struct bcast_packet *bcast_packet;
  	struct ethhdr *ethhdr;
  	int hdr_size = sizeof(struct bcast_packet);
  	int ret = NET_RX_DROP;
  	int32_t seq_diff;
  
  	/* drop packet if it has not necessary minimum size */
  	if (unlikely(!pskb_may_pull(skb, hdr_size)))
  		goto out;
  
  	ethhdr = (struct ethhdr *)skb_mac_header(skb);
  
  	/* packet with broadcast indication but unicast recipient */
  	if (!is_broadcast_ether_addr(ethhdr->h_dest))
  		goto out;
  
  	/* packet with broadcast sender address */
  	if (is_broadcast_ether_addr(ethhdr->h_source))
  		goto out;
  
  	/* ignore broadcasts sent by myself */
  	if (is_my_mac(ethhdr->h_source))
  		goto out;
  
  	bcast_packet = (struct bcast_packet *)skb->data;
  
  	/* ignore broadcasts originated by myself */
  	if (is_my_mac(bcast_packet->orig))
  		goto out;
  
  	if (bcast_packet->ttl < 2)
  		goto out;
  
  	orig_node = orig_hash_find(bat_priv, bcast_packet->orig);
  
  	if (!orig_node)
  		goto out;
  
  	spin_lock_bh(&orig_node->bcast_seqno_lock);
  
  	/* check whether the packet is a duplicate */
  	if (get_bit_status(orig_node->bcast_bits, orig_node->last_bcast_seqno,
  			   ntohl(bcast_packet->seqno)))
  		goto spin_unlock;
  
  	seq_diff = ntohl(bcast_packet->seqno) - orig_node->last_bcast_seqno;
  
  	/* check whether the packet is old and the host just restarted. */
  	if (window_protected(bat_priv, seq_diff,
  			     &orig_node->bcast_seqno_reset))
  		goto spin_unlock;
  
  	/* mark broadcast in flood history, update window position
  	 * if required. */
  	if (bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1))
  		orig_node->last_bcast_seqno = ntohl(bcast_packet->seqno);
  
  	spin_unlock_bh(&orig_node->bcast_seqno_lock);
  
  	/* rebroadcast packet */
  	add_bcast_packet_to_list(bat_priv, skb);
  
  	/* broadcast for me */
  	interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
  	ret = NET_RX_SUCCESS;
  	goto out;
  
  spin_unlock:
  	spin_unlock_bh(&orig_node->bcast_seqno_lock);
  out:
  	if (orig_node)
  		orig_node_free_ref(orig_node);
  	return ret;
  }
  
  int recv_vis_packet(struct sk_buff *skb, struct hard_iface *recv_if)
  {
  	struct vis_packet *vis_packet;
  	struct ethhdr *ethhdr;
  	struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
  	int hdr_size = sizeof(struct vis_packet);
  
  	/* keep skb linear */
  	if (skb_linearize(skb) < 0)
  		return NET_RX_DROP;
  
  	if (unlikely(!pskb_may_pull(skb, hdr_size)))
  		return NET_RX_DROP;
  
  	vis_packet = (struct vis_packet *)skb->data;
  	ethhdr = (struct ethhdr *)skb_mac_header(skb);
  
  	/* not for me */
  	if (!is_my_mac(ethhdr->h_dest))
  		return NET_RX_DROP;
  
  	/* ignore own packets */
  	if (is_my_mac(vis_packet->vis_orig))
  		return NET_RX_DROP;
  
  	if (is_my_mac(vis_packet->sender_orig))
  		return NET_RX_DROP;
  
  	switch (vis_packet->vis_type) {
  	case VIS_TYPE_SERVER_SYNC:
  		receive_server_sync_packet(bat_priv, vis_packet,
  					   skb_headlen(skb));
  		break;
  
  	case VIS_TYPE_CLIENT_UPDATE:
  		receive_client_update_packet(bat_priv, vis_packet,
  					     skb_headlen(skb));
  		break;
  
  	default:	/* ignore unknown packet */
  		break;
  	}
  
  	/* We take a copy of the data in the packet, so we should
  	   always free the skbuf. */
  	return NET_RX_DROP;
  }
  