/*

   * 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 "translation-table.h"
  #include "soft-interface.h"

  #include "hard-interface.h"

  #include "send.h"

  #include "hash.h"
  #include "originator.h"

  #include "routing.h"

  #include <linux/crc16.h>
  
  static void _tt_global_del(struct bat_priv *bat_priv,
  			   struct tt_global_entry *tt_global_entry,
  			   const char *message);
  static void tt_purge(struct work_struct *work);

  /* returns 1 if they are the same mac addr */

  static int compare_tt(const struct hlist_node *node, const void *data2)

  {

  	const void *data1 = container_of(node, struct tt_common_entry,

  					 hash_entry);

  
  	return (memcmp(data1, data2, ETH_ALEN) == 0 ? 1 : 0);
  }

  static void tt_start_timer(struct bat_priv *bat_priv)

  {

  	INIT_DELAYED_WORK(&bat_priv->tt_work, tt_purge);
  	queue_delayed_work(bat_event_workqueue, &bat_priv->tt_work,
  			   msecs_to_jiffies(5000));

  }

  static struct tt_common_entry *tt_hash_find(struct hashtable_t *hash,
  					    const void *data)

  {

  	struct hlist_head *head;
  	struct hlist_node *node;

  	struct tt_common_entry *tt_common_entry, *tt_common_entry_tmp = NULL;

  	uint32_t index;

  
  	if (!hash)
  		return NULL;
  
  	index = choose_orig(data, hash->size);
  	head = &hash->table[index];
  
  	rcu_read_lock();

  	hlist_for_each_entry_rcu(tt_common_entry, node, head, hash_entry) {
  		if (!compare_eth(tt_common_entry, data))

  			continue;

  		if (!atomic_inc_not_zero(&tt_common_entry->refcount))

  			continue;

  		tt_common_entry_tmp = tt_common_entry;

  		break;
  	}
  	rcu_read_unlock();

  	return tt_common_entry_tmp;

  }

  static struct tt_local_entry *tt_local_hash_find(struct bat_priv *bat_priv,
  						 const void *data)

  {

  	struct tt_common_entry *tt_common_entry;
  	struct tt_local_entry *tt_local_entry = NULL;

  	tt_common_entry = tt_hash_find(bat_priv->tt_local_hash, data);
  	if (tt_common_entry)
  		tt_local_entry = container_of(tt_common_entry,
  					      struct tt_local_entry, common);
  	return tt_local_entry;
  }

  static struct tt_global_entry *tt_global_hash_find(struct bat_priv *bat_priv,
  						   const void *data)
  {
  	struct tt_common_entry *tt_common_entry;
  	struct tt_global_entry *tt_global_entry = NULL;

  	tt_common_entry = tt_hash_find(bat_priv->tt_global_hash, data);
  	if (tt_common_entry)
  		tt_global_entry = container_of(tt_common_entry,
  					       struct tt_global_entry, common);
  	return tt_global_entry;

  }

  static bool is_out_of_time(unsigned long starting_time, unsigned long timeout)
  {
  	unsigned long deadline;
  	deadline = starting_time + msecs_to_jiffies(timeout);
  
  	return time_after(jiffies, deadline);
  }

  static void tt_local_entry_free_ref(struct tt_local_entry *tt_local_entry)
  {

  	if (atomic_dec_and_test(&tt_local_entry->common.refcount))
  		kfree_rcu(tt_local_entry, common.rcu);

  }

  static void tt_global_entry_free_rcu(struct rcu_head *rcu)
  {

  	struct tt_common_entry *tt_common_entry;

  	struct tt_global_entry *tt_global_entry;

  	tt_common_entry = container_of(rcu, struct tt_common_entry, rcu);
  	tt_global_entry = container_of(tt_common_entry, struct tt_global_entry,
  				       common);

  
  	if (tt_global_entry->orig_node)
  		orig_node_free_ref(tt_global_entry->orig_node);
  
  	kfree(tt_global_entry);
  }

  static void tt_global_entry_free_ref(struct tt_global_entry *tt_global_entry)
  {

  	if (atomic_dec_and_test(&tt_global_entry->common.refcount))
  		call_rcu(&tt_global_entry->common.rcu,
  			 tt_global_entry_free_rcu);

  }

  static void tt_local_event(struct bat_priv *bat_priv, const uint8_t *addr,
  			   uint8_t flags)

  {
  	struct tt_change_node *tt_change_node;
  
  	tt_change_node = kmalloc(sizeof(*tt_change_node), GFP_ATOMIC);
  
  	if (!tt_change_node)
  		return;

  	tt_change_node->change.flags = flags;

  	memcpy(tt_change_node->change.addr, addr, ETH_ALEN);
  
  	spin_lock_bh(&bat_priv->tt_changes_list_lock);
  	/* track the change in the OGMinterval list */
  	list_add_tail(&tt_change_node->list, &bat_priv->tt_changes_list);
  	atomic_inc(&bat_priv->tt_local_changes);
  	spin_unlock_bh(&bat_priv->tt_changes_list_lock);
  
  	atomic_set(&bat_priv->tt_ogm_append_cnt, 0);
  }
  
  int tt_len(int changes_num)
  {
  	return changes_num * sizeof(struct tt_change);
  }
  
  static int tt_local_init(struct bat_priv *bat_priv)

  {

  	if (bat_priv->tt_local_hash)

  		return 1;

  	bat_priv->tt_local_hash = hash_new(1024);

  	if (!bat_priv->tt_local_hash)

  		return 0;

  	return 1;
  }

  void tt_local_add(struct net_device *soft_iface, const uint8_t *addr,
  		  int ifindex)

  {
  	struct bat_priv *bat_priv = netdev_priv(soft_iface);

  	struct tt_local_entry *tt_local_entry = NULL;
  	struct tt_global_entry *tt_global_entry = NULL;

  	int hash_added;

  	tt_local_entry = tt_local_hash_find(bat_priv, addr);

  	if (tt_local_entry) {
  		tt_local_entry->last_seen = jiffies;

  		goto out;

  	}

  	tt_local_entry = kmalloc(sizeof(*tt_local_entry), GFP_ATOMIC);

  	if (!tt_local_entry)

  		goto out;

  	bat_dbg(DBG_TT, bat_priv,
  		"Creating new local tt entry: %pM (ttvn: %d)
  ", addr,
  		(uint8_t)atomic_read(&bat_priv->ttvn));

  	memcpy(tt_local_entry->common.addr, addr, ETH_ALEN);
  	tt_local_entry->common.flags = NO_FLAGS;

  	if (is_wifi_iface(ifindex))

  		tt_local_entry->common.flags |= TT_CLIENT_WIFI;
  	atomic_set(&tt_local_entry->common.refcount, 2);
  	tt_local_entry->last_seen = jiffies;

  
  	/* the batman interface mac address should never be purged */

  	if (compare_eth(addr, soft_iface->dev_addr))

  		tt_local_entry->common.flags |= TT_CLIENT_NOPURGE;

  	hash_added = hash_add(bat_priv->tt_local_hash, compare_tt, choose_orig,
  			 &tt_local_entry->common,
  			 &tt_local_entry->common.hash_entry);
  
  	if (unlikely(hash_added != 0)) {
  		/* remove the reference for the hash */
  		tt_local_entry_free_ref(tt_local_entry);
  		goto out;
  	}

  	tt_local_event(bat_priv, addr, tt_local_entry->common.flags);

  	/* The local entry has to be marked as NEW to avoid to send it in
  	 * a full table response going out before the next ttvn increment
  	 * (consistency check) */

  	tt_local_entry->common.flags |= TT_CLIENT_NEW;

  	/* remove address from global hash if present */

  	tt_global_entry = tt_global_hash_find(bat_priv, addr);

  	/* Check whether it is a roaming! */
  	if (tt_global_entry) {

  		/* This node is probably going to update its tt table */
  		tt_global_entry->orig_node->tt_poss_change = true;

  		/* The global entry has to be marked as ROAMING and has to be

  		 * kept for consistency purpose */

  		tt_global_entry->common.flags |= TT_CLIENT_ROAM;

  		tt_global_entry->roam_at = jiffies;

  		send_roam_adv(bat_priv, tt_global_entry->common.addr,

  			      tt_global_entry->orig_node);
  	}
  out:
  	if (tt_local_entry)
  		tt_local_entry_free_ref(tt_local_entry);
  	if (tt_global_entry)
  		tt_global_entry_free_ref(tt_global_entry);

  }

  int tt_changes_fill_buffer(struct bat_priv *bat_priv,
  			   unsigned char *buff, int buff_len)

  {

  	int count = 0, tot_changes = 0;
  	struct tt_change_node *entry, *safe;

  	if (buff_len > 0)
  		tot_changes = buff_len / tt_len(1);

  	spin_lock_bh(&bat_priv->tt_changes_list_lock);
  	atomic_set(&bat_priv->tt_local_changes, 0);

  	list_for_each_entry_safe(entry, safe, &bat_priv->tt_changes_list,
  			list) {
  		if (count < tot_changes) {
  			memcpy(buff + tt_len(count),
  			       &entry->change, sizeof(struct tt_change));

  			count++;
  		}

  		list_del(&entry->list);
  		kfree(entry);

  	}

  	spin_unlock_bh(&bat_priv->tt_changes_list_lock);
  
  	/* Keep the buffer for possible tt_request */
  	spin_lock_bh(&bat_priv->tt_buff_lock);
  	kfree(bat_priv->tt_buff);
  	bat_priv->tt_buff_len = 0;
  	bat_priv->tt_buff = NULL;
  	/* We check whether this new OGM has no changes due to size
  	 * problems */
  	if (buff_len > 0) {
  		/**
  		 * if kmalloc() fails we will reply with the full table
  		 * instead of providing the diff
  		 */
  		bat_priv->tt_buff = kmalloc(buff_len, GFP_ATOMIC);
  		if (bat_priv->tt_buff) {
  			memcpy(bat_priv->tt_buff, buff, buff_len);
  			bat_priv->tt_buff_len = buff_len;
  		}
  	}
  	spin_unlock_bh(&bat_priv->tt_buff_lock);

  	return tot_changes;

  }

  int tt_local_seq_print_text(struct seq_file *seq, void *offset)

  {
  	struct net_device *net_dev = (struct net_device *)seq->private;
  	struct bat_priv *bat_priv = netdev_priv(net_dev);

  	struct hashtable_t *hash = bat_priv->tt_local_hash;

  	struct tt_common_entry *tt_common_entry;

  	struct hard_iface *primary_if;

  	struct hlist_node *node;

  	struct hlist_head *head;

  	uint32_t i;
  	int ret = 0;

  
  	primary_if = primary_if_get_selected(bat_priv);
  	if (!primary_if) {
  		ret = seq_printf(seq, "BATMAN mesh %s disabled - "
  				 "please specify interfaces to enable it
  ",
  				 net_dev->name);
  		goto out;
  	}

  	if (primary_if->if_status != IF_ACTIVE) {
  		ret = seq_printf(seq, "BATMAN mesh %s disabled - "
  				 "primary interface not active
  ",
  				 net_dev->name);
  		goto out;

  	}
  
  	seq_printf(seq, "Locally retrieved addresses (from %s) "

  		   "announced via TT (TTVN: %u):
  ",
  		   net_dev->name, (uint8_t)atomic_read(&bat_priv->ttvn));

  	for (i = 0; i < hash->size; i++) {
  		head = &hash->table[i];

  		rcu_read_lock();

  		hlist_for_each_entry_rcu(tt_common_entry, node,

  					 head, hash_entry) {

  			seq_printf(seq, " * %pM [%c%c%c%c%c]
  ",

  					tt_common_entry->addr,
  					(tt_common_entry->flags &

  					 TT_CLIENT_ROAM ? 'R' : '.'),

  					(tt_common_entry->flags &

  					 TT_CLIENT_NOPURGE ? 'P' : '.'),

  					(tt_common_entry->flags &

  					 TT_CLIENT_NEW ? 'N' : '.'),

  					(tt_common_entry->flags &

  					 TT_CLIENT_PENDING ? 'X' : '.'),

  					(tt_common_entry->flags &

  					 TT_CLIENT_WIFI ? 'W' : '.'));

  		}

  		rcu_read_unlock();

  	}

  out:
  	if (primary_if)
  		hardif_free_ref(primary_if);
  	return ret;

  }

  static void tt_local_set_pending(struct bat_priv *bat_priv,
  				 struct tt_local_entry *tt_local_entry,
  				 uint16_t flags)

  {

  	tt_local_event(bat_priv, tt_local_entry->common.addr,
  		       tt_local_entry->common.flags | flags);

  	/* The local client has to be marked as "pending to be removed" but has
  	 * to be kept in the table in order to send it in a full table

  	 * response issued before the net ttvn increment (consistency check) */

  	tt_local_entry->common.flags |= TT_CLIENT_PENDING;

  }

  void tt_local_remove(struct bat_priv *bat_priv, const uint8_t *addr,

  		     const char *message, bool roaming)

  {

  	struct tt_local_entry *tt_local_entry = NULL;

  	tt_local_entry = tt_local_hash_find(bat_priv, addr);

  	if (!tt_local_entry)
  		goto out;

  	tt_local_set_pending(bat_priv, tt_local_entry, TT_CLIENT_DEL |
  			     (roaming ? TT_CLIENT_ROAM : NO_FLAGS));
  
  	bat_dbg(DBG_TT, bat_priv, "Local tt entry (%pM) pending to be removed: "

  		"%s
  ", tt_local_entry->common.addr, message);

  out:
  	if (tt_local_entry)
  		tt_local_entry_free_ref(tt_local_entry);

  }

  static void tt_local_purge(struct bat_priv *bat_priv)

  {

  	struct hashtable_t *hash = bat_priv->tt_local_hash;
  	struct tt_local_entry *tt_local_entry;

  	struct tt_common_entry *tt_common_entry;

  	struct hlist_node *node, *node_tmp;

  	struct hlist_head *head;

  	spinlock_t *list_lock; /* protects write access to the hash lists */

  	uint32_t i;

  	for (i = 0; i < hash->size; i++) {
  		head = &hash->table[i];

  		list_lock = &hash->list_locks[i];

  		spin_lock_bh(list_lock);

  		hlist_for_each_entry_safe(tt_common_entry, node, node_tmp,

  					  head, hash_entry) {

  			tt_local_entry = container_of(tt_common_entry,
  						      struct tt_local_entry,
  						      common);
  			if (tt_local_entry->common.flags & TT_CLIENT_NOPURGE)

  				continue;

  			/* entry already marked for deletion */

  			if (tt_local_entry->common.flags & TT_CLIENT_PENDING)

  				continue;

  			if (!is_out_of_time(tt_local_entry->last_seen,

  					    TT_LOCAL_TIMEOUT * 1000))

  				continue;

  			tt_local_set_pending(bat_priv, tt_local_entry,
  					     TT_CLIENT_DEL);
  			bat_dbg(DBG_TT, bat_priv, "Local tt entry (%pM) "
  				"pending to be removed: timed out
  ",

  				tt_local_entry->common.addr);

  		}

  		spin_unlock_bh(list_lock);

  	}

  }

  static void tt_local_table_free(struct bat_priv *bat_priv)

  {

  	struct hashtable_t *hash;

  	spinlock_t *list_lock; /* protects write access to the hash lists */

  	struct tt_common_entry *tt_common_entry;

  	struct tt_local_entry *tt_local_entry;

  	struct hlist_node *node, *node_tmp;
  	struct hlist_head *head;

  	uint32_t i;

  	if (!bat_priv->tt_local_hash)

  		return;

  	hash = bat_priv->tt_local_hash;
  
  	for (i = 0; i < hash->size; i++) {
  		head = &hash->table[i];
  		list_lock = &hash->list_locks[i];
  
  		spin_lock_bh(list_lock);

  		hlist_for_each_entry_safe(tt_common_entry, node, node_tmp,

  					  head, hash_entry) {
  			hlist_del_rcu(node);

  			tt_local_entry = container_of(tt_common_entry,
  						      struct tt_local_entry,
  						      common);

  			tt_local_entry_free_ref(tt_local_entry);

  		}
  		spin_unlock_bh(list_lock);
  	}
  
  	hash_destroy(hash);

  	bat_priv->tt_local_hash = NULL;

  }

  static int tt_global_init(struct bat_priv *bat_priv)

  {

  	if (bat_priv->tt_global_hash)

  		return 1;

  	bat_priv->tt_global_hash = hash_new(1024);

  	if (!bat_priv->tt_global_hash)

  		return 0;
  
  	return 1;
  }

  static void tt_changes_list_free(struct bat_priv *bat_priv)

  {

  	struct tt_change_node *entry, *safe;

  	spin_lock_bh(&bat_priv->tt_changes_list_lock);

  	list_for_each_entry_safe(entry, safe, &bat_priv->tt_changes_list,
  				 list) {
  		list_del(&entry->list);
  		kfree(entry);
  	}

  	atomic_set(&bat_priv->tt_local_changes, 0);
  	spin_unlock_bh(&bat_priv->tt_changes_list_lock);
  }

  /* caller must hold orig_node refcount */
  int tt_global_add(struct bat_priv *bat_priv, struct orig_node *orig_node,

  		  const unsigned char *tt_addr, uint8_t ttvn, bool roaming,
  		  bool wifi)

  {
  	struct tt_global_entry *tt_global_entry;

  	struct orig_node *orig_node_tmp;

  	int ret = 0;

  	int hash_added;

  	tt_global_entry = tt_global_hash_find(bat_priv, tt_addr);
  
  	if (!tt_global_entry) {
  		tt_global_entry =
  			kmalloc(sizeof(*tt_global_entry),
  				GFP_ATOMIC);
  		if (!tt_global_entry)

  			goto out;

  		memcpy(tt_global_entry->common.addr, tt_addr, ETH_ALEN);
  		tt_global_entry->common.flags = NO_FLAGS;
  		atomic_set(&tt_global_entry->common.refcount, 2);

  		/* Assign the new orig_node */
  		atomic_inc(&orig_node->refcount);

  		tt_global_entry->orig_node = orig_node;

  		tt_global_entry->ttvn = ttvn;

  		tt_global_entry->roam_at = 0;

  		hash_added = hash_add(bat_priv->tt_global_hash, compare_tt,
  				 choose_orig, &tt_global_entry->common,
  				 &tt_global_entry->common.hash_entry);
  
  		if (unlikely(hash_added != 0)) {
  			/* remove the reference for the hash */
  			tt_global_entry_free_ref(tt_global_entry);
  			goto out_remove;
  		}

  		atomic_inc(&orig_node->tt_size);

  	} else {
  		if (tt_global_entry->orig_node != orig_node) {
  			atomic_dec(&tt_global_entry->orig_node->tt_size);
  			orig_node_tmp = tt_global_entry->orig_node;
  			atomic_inc(&orig_node->refcount);
  			tt_global_entry->orig_node = orig_node;

  			orig_node_free_ref(orig_node_tmp);
  			atomic_inc(&orig_node->tt_size);
  		}

  		tt_global_entry->common.flags = NO_FLAGS;

  		tt_global_entry->ttvn = ttvn;

  		tt_global_entry->roam_at = 0;

  	}

  	if (wifi)

  		tt_global_entry->common.flags |= TT_CLIENT_WIFI;

  	bat_dbg(DBG_TT, bat_priv,
  		"Creating new global tt entry: %pM (via %pM)
  ",

  		tt_global_entry->common.addr, orig_node->orig);

  out_remove:

  	/* remove address from local hash if present */

  	tt_local_remove(bat_priv, tt_global_entry->common.addr,

  			"global tt received", roaming);
  	ret = 1;
  out:
  	if (tt_global_entry)
  		tt_global_entry_free_ref(tt_global_entry);
  	return ret;

  }

  int tt_global_seq_print_text(struct seq_file *seq, void *offset)

  {
  	struct net_device *net_dev = (struct net_device *)seq->private;
  	struct bat_priv *bat_priv = netdev_priv(net_dev);

  	struct hashtable_t *hash = bat_priv->tt_global_hash;

  	struct tt_common_entry *tt_common_entry;

  	struct tt_global_entry *tt_global_entry;

  	struct hard_iface *primary_if;

  	struct hlist_node *node;

  	struct hlist_head *head;

  	uint32_t i;
  	int ret = 0;

  
  	primary_if = primary_if_get_selected(bat_priv);
  	if (!primary_if) {
  		ret = seq_printf(seq, "BATMAN mesh %s disabled - please "
  				 "specify interfaces to enable it
  ",
  				 net_dev->name);
  		goto out;
  	}

  	if (primary_if->if_status != IF_ACTIVE) {
  		ret = seq_printf(seq, "BATMAN mesh %s disabled - "
  				 "primary interface not active
  ",
  				 net_dev->name);
  		goto out;

  	}

  	seq_printf(seq,
  		   "Globally announced TT entries received via the mesh %s
  ",

  		   net_dev->name);

  	seq_printf(seq, "       %-13s %s       %-15s %s %s
  ",
  		   "Client", "(TTVN)", "Originator", "(Curr TTVN)", "Flags");

  	for (i = 0; i < hash->size; i++) {
  		head = &hash->table[i];

  		rcu_read_lock();

  		hlist_for_each_entry_rcu(tt_common_entry, node,

  					 head, hash_entry) {

  			tt_global_entry = container_of(tt_common_entry,
  						       struct tt_global_entry,
  						       common);

  			seq_printf(seq, " * %pM  (%3u) via %pM     (%3u)   "

  					"[%c%c%c]
  ",
  					tt_global_entry->common.addr,

  					tt_global_entry->ttvn,
  					tt_global_entry->orig_node->orig,
  					(uint8_t) atomic_read(
  						&tt_global_entry->orig_node->

  						last_ttvn),

  					(tt_global_entry->common.flags &

  					 TT_CLIENT_ROAM ? 'R' : '.'),

  					(tt_global_entry->common.flags &

  					 TT_CLIENT_PENDING ? 'X' : '.'),

  					(tt_global_entry->common.flags &

  					 TT_CLIENT_WIFI ? 'W' : '.'));

  		}

  		rcu_read_unlock();

  	}

  out:
  	if (primary_if)
  		hardif_free_ref(primary_if);
  	return ret;

  }

  static void _tt_global_del(struct bat_priv *bat_priv,
  			   struct tt_global_entry *tt_global_entry,
  			   const char *message)

  {

  	if (!tt_global_entry)

  		goto out;

  
  	bat_dbg(DBG_TT, bat_priv,

  		"Deleting global tt entry %pM (via %pM): %s
  ",

  		tt_global_entry->common.addr, tt_global_entry->orig_node->orig,

  		message);

  	atomic_dec(&tt_global_entry->orig_node->tt_size);

  	hash_remove(bat_priv->tt_global_hash, compare_tt, choose_orig,
  		    tt_global_entry->common.addr);

  out:
  	if (tt_global_entry)
  		tt_global_entry_free_ref(tt_global_entry);

  }

  void tt_global_del(struct bat_priv *bat_priv,
  		   struct orig_node *orig_node, const unsigned char *addr,

  		   const char *message, bool roaming)

  {

  	struct tt_global_entry *tt_global_entry = NULL;

  	struct tt_local_entry *tt_local_entry = NULL;

  	tt_global_entry = tt_global_hash_find(bat_priv, addr);

  	if (!tt_global_entry)
  		goto out;

  	if (tt_global_entry->orig_node == orig_node) {

  		if (roaming) {

  			/* if we are deleting a global entry due to a roam
  			 * event, there are two possibilities:
  			 * 1) the client roamed from node A to node B => we mark
  			 *    it with TT_CLIENT_ROAM, we start a timer and we
  			 *    wait for node B to claim it. In case of timeout
  			 *    the entry is purged.
  			 * 2) the client roamed to us => we can directly delete
  			 *    the global entry, since it is useless now. */
  			tt_local_entry = tt_local_hash_find(bat_priv,

  							    tt_global_entry->common.addr);

  			if (!tt_local_entry) {

  				tt_global_entry->common.flags |= TT_CLIENT_ROAM;

  				tt_global_entry->roam_at = jiffies;
  				goto out;
  			}

  		}

  		_tt_global_del(bat_priv, tt_global_entry, message);
  	}

  out:

  	if (tt_global_entry)
  		tt_global_entry_free_ref(tt_global_entry);

  	if (tt_local_entry)
  		tt_local_entry_free_ref(tt_local_entry);

  }

  void tt_global_del_orig(struct bat_priv *bat_priv,

  			struct orig_node *orig_node, const char *message)

  {

  	struct tt_global_entry *tt_global_entry;

  	struct tt_common_entry *tt_common_entry;

  	uint32_t i;

  	struct hashtable_t *hash = bat_priv->tt_global_hash;
  	struct hlist_node *node, *safe;
  	struct hlist_head *head;

  	spinlock_t *list_lock; /* protects write access to the hash lists */

  	if (!hash)
  		return;

  	for (i = 0; i < hash->size; i++) {
  		head = &hash->table[i];

  		list_lock = &hash->list_locks[i];

  		spin_lock_bh(list_lock);

  		hlist_for_each_entry_safe(tt_common_entry, node, safe,

  					 head, hash_entry) {

  			tt_global_entry = container_of(tt_common_entry,
  						       struct tt_global_entry,
  						       common);

  			if (tt_global_entry->orig_node == orig_node) {
  				bat_dbg(DBG_TT, bat_priv,
  					"Deleting global tt entry %pM "

  					"(via %pM): %s
  ",

  					tt_global_entry->common.addr,

  					tt_global_entry->orig_node->orig,
  					message);

  				hlist_del_rcu(node);
  				tt_global_entry_free_ref(tt_global_entry);
  			}

  		}

  		spin_unlock_bh(list_lock);

  	}

  	atomic_set(&orig_node->tt_size, 0);

  }

  static void tt_global_roam_purge(struct bat_priv *bat_priv)
  {
  	struct hashtable_t *hash = bat_priv->tt_global_hash;

  	struct tt_common_entry *tt_common_entry;

  	struct tt_global_entry *tt_global_entry;
  	struct hlist_node *node, *node_tmp;
  	struct hlist_head *head;

  	spinlock_t *list_lock; /* protects write access to the hash lists */

  	uint32_t i;

  	for (i = 0; i < hash->size; i++) {
  		head = &hash->table[i];

  		list_lock = &hash->list_locks[i];

  		spin_lock_bh(list_lock);

  		hlist_for_each_entry_safe(tt_common_entry, node, node_tmp,

  					  head, hash_entry) {

  			tt_global_entry = container_of(tt_common_entry,
  						       struct tt_global_entry,
  						       common);
  			if (!(tt_global_entry->common.flags & TT_CLIENT_ROAM))

  				continue;
  			if (!is_out_of_time(tt_global_entry->roam_at,
  					    TT_CLIENT_ROAM_TIMEOUT * 1000))
  				continue;

  			bat_dbg(DBG_TT, bat_priv, "Deleting global "
  				"tt entry (%pM): Roaming timeout
  ",

  				tt_global_entry->common.addr);

  			atomic_dec(&tt_global_entry->orig_node->tt_size);
  			hlist_del_rcu(node);
  			tt_global_entry_free_ref(tt_global_entry);

  		}

  		spin_unlock_bh(list_lock);

  	}

  }

  static void tt_global_table_free(struct bat_priv *bat_priv)

  {

  	struct hashtable_t *hash;
  	spinlock_t *list_lock; /* protects write access to the hash lists */

  	struct tt_common_entry *tt_common_entry;

  	struct tt_global_entry *tt_global_entry;
  	struct hlist_node *node, *node_tmp;
  	struct hlist_head *head;

  	uint32_t i;

  	if (!bat_priv->tt_global_hash)

  		return;

  	hash = bat_priv->tt_global_hash;
  
  	for (i = 0; i < hash->size; i++) {
  		head = &hash->table[i];
  		list_lock = &hash->list_locks[i];
  
  		spin_lock_bh(list_lock);

  		hlist_for_each_entry_safe(tt_common_entry, node, node_tmp,

  					  head, hash_entry) {
  			hlist_del_rcu(node);

  			tt_global_entry = container_of(tt_common_entry,
  						       struct tt_global_entry,
  						       common);

  			tt_global_entry_free_ref(tt_global_entry);
  		}
  		spin_unlock_bh(list_lock);
  	}
  
  	hash_destroy(hash);

  	bat_priv->tt_global_hash = NULL;

  }

  static bool _is_ap_isolated(struct tt_local_entry *tt_local_entry,
  			    struct tt_global_entry *tt_global_entry)
  {
  	bool ret = false;

  	if (tt_local_entry->common.flags & TT_CLIENT_WIFI &&
  	    tt_global_entry->common.flags & TT_CLIENT_WIFI)

  		ret = true;
  
  	return ret;
  }

  struct orig_node *transtable_search(struct bat_priv *bat_priv,

  				    const uint8_t *src, const uint8_t *addr)

  {

  	struct tt_local_entry *tt_local_entry = NULL;
  	struct tt_global_entry *tt_global_entry = NULL;

  	struct orig_node *orig_node = NULL;

  	if (src && atomic_read(&bat_priv->ap_isolation)) {
  		tt_local_entry = tt_local_hash_find(bat_priv, src);
  		if (!tt_local_entry)
  			goto out;
  	}

  	tt_global_entry = tt_global_hash_find(bat_priv, addr);

  	if (!tt_global_entry)

  		goto out;

  	/* check whether the clients should not communicate due to AP
  	 * isolation */
  	if (tt_local_entry && _is_ap_isolated(tt_local_entry, tt_global_entry))
  		goto out;

  	if (!atomic_inc_not_zero(&tt_global_entry->orig_node->refcount))

  		goto out;

  	/* A global client marked as PENDING has already moved from that
  	 * originator */

  	if (tt_global_entry->common.flags & TT_CLIENT_PENDING)

  		goto out;

  	orig_node = tt_global_entry->orig_node;

  out:

  	if (tt_global_entry)
  		tt_global_entry_free_ref(tt_global_entry);
  	if (tt_local_entry)
  		tt_local_entry_free_ref(tt_local_entry);

  	return orig_node;

  }

  
  /* Calculates the checksum of the local table of a given orig_node */
  uint16_t tt_global_crc(struct bat_priv *bat_priv, struct orig_node *orig_node)
  {
  	uint16_t total = 0, total_one;
  	struct hashtable_t *hash = bat_priv->tt_global_hash;

  	struct tt_common_entry *tt_common_entry;

  	struct tt_global_entry *tt_global_entry;
  	struct hlist_node *node;
  	struct hlist_head *head;

  	uint32_t i;
  	int j;

  
  	for (i = 0; i < hash->size; i++) {
  		head = &hash->table[i];
  
  		rcu_read_lock();

  		hlist_for_each_entry_rcu(tt_common_entry, node,

  					 head, hash_entry) {

  			tt_global_entry = container_of(tt_common_entry,
  						       struct tt_global_entry,
  						       common);

  			if (compare_eth(tt_global_entry->orig_node,
  					orig_node)) {

  				/* Roaming clients are in the global table for
  				 * consistency only. They don't have to be
  				 * taken into account while computing the
  				 * global crc */

  				if (tt_common_entry->flags & TT_CLIENT_ROAM)

  					continue;

  				total_one = 0;
  				for (j = 0; j < ETH_ALEN; j++)
  					total_one = crc16_byte(total_one,

  						tt_common_entry->addr[j]);

  				total ^= total_one;
  			}
  		}
  		rcu_read_unlock();
  	}
  
  	return total;
  }
  
  /* Calculates the checksum of the local table */
  uint16_t tt_local_crc(struct bat_priv *bat_priv)
  {
  	uint16_t total = 0, total_one;
  	struct hashtable_t *hash = bat_priv->tt_local_hash;

  	struct tt_common_entry *tt_common_entry;

  	struct hlist_node *node;
  	struct hlist_head *head;

  	uint32_t i;
  	int j;

  
  	for (i = 0; i < hash->size; i++) {
  		head = &hash->table[i];
  
  		rcu_read_lock();

  		hlist_for_each_entry_rcu(tt_common_entry, node,

  					 head, hash_entry) {

  			/* not yet committed clients have not to be taken into
  			 * account while computing the CRC */

  			if (tt_common_entry->flags & TT_CLIENT_NEW)

  				continue;

  			total_one = 0;
  			for (j = 0; j < ETH_ALEN; j++)
  				total_one = crc16_byte(total_one,

  						   tt_common_entry->addr[j]);

  			total ^= total_one;
  		}

  		rcu_read_unlock();
  	}
  
  	return total;
  }
  
  static void tt_req_list_free(struct bat_priv *bat_priv)
  {
  	struct tt_req_node *node, *safe;
  
  	spin_lock_bh(&bat_priv->tt_req_list_lock);
  
  	list_for_each_entry_safe(node, safe, &bat_priv->tt_req_list, list) {
  		list_del(&node->list);
  		kfree(node);
  	}
  
  	spin_unlock_bh(&bat_priv->tt_req_list_lock);
  }
  
  void tt_save_orig_buffer(struct bat_priv *bat_priv, struct orig_node *orig_node,
  			 const unsigned char *tt_buff, uint8_t tt_num_changes)
  {
  	uint16_t tt_buff_len = tt_len(tt_num_changes);
  
  	/* Replace the old buffer only if I received something in the
  	 * last OGM (the OGM could carry no changes) */
  	spin_lock_bh(&orig_node->tt_buff_lock);
  	if (tt_buff_len > 0) {
  		kfree(orig_node->tt_buff);
  		orig_node->tt_buff_len = 0;
  		orig_node->tt_buff = kmalloc(tt_buff_len, GFP_ATOMIC);
  		if (orig_node->tt_buff) {
  			memcpy(orig_node->tt_buff, tt_buff, tt_buff_len);
  			orig_node->tt_buff_len = tt_buff_len;
  		}
  	}
  	spin_unlock_bh(&orig_node->tt_buff_lock);
  }
  
  static void tt_req_purge(struct bat_priv *bat_priv)
  {
  	struct tt_req_node *node, *safe;
  
  	spin_lock_bh(&bat_priv->tt_req_list_lock);
  	list_for_each_entry_safe(node, safe, &bat_priv->tt_req_list, list) {
  		if (is_out_of_time(node->issued_at,
  		    TT_REQUEST_TIMEOUT * 1000)) {
  			list_del(&node->list);
  			kfree(node);
  		}
  	}
  	spin_unlock_bh(&bat_priv->tt_req_list_lock);
  }
  
  /* returns the pointer to the new tt_req_node struct if no request
   * has already been issued for this orig_node, NULL otherwise */
  static struct tt_req_node *new_tt_req_node(struct bat_priv *bat_priv,
  					  struct orig_node *orig_node)
  {
  	struct tt_req_node *tt_req_node_tmp, *tt_req_node = NULL;
  
  	spin_lock_bh(&bat_priv->tt_req_list_lock);
  	list_for_each_entry(tt_req_node_tmp, &bat_priv->tt_req_list, list) {
  		if (compare_eth(tt_req_node_tmp, orig_node) &&
  		    !is_out_of_time(tt_req_node_tmp->issued_at,
  				    TT_REQUEST_TIMEOUT * 1000))
  			goto unlock;
  	}
  
  	tt_req_node = kmalloc(sizeof(*tt_req_node), GFP_ATOMIC);
  	if (!tt_req_node)
  		goto unlock;
  
  	memcpy(tt_req_node->addr, orig_node->orig, ETH_ALEN);
  	tt_req_node->issued_at = jiffies;
  
  	list_add(&tt_req_node->list, &bat_priv->tt_req_list);
  unlock:
  	spin_unlock_bh(&bat_priv->tt_req_list_lock);
  	return tt_req_node;
  }

  /* data_ptr is useless here, but has to be kept to respect the prototype */
  static int tt_local_valid_entry(const void *entry_ptr, const void *data_ptr)
  {

  	const struct tt_common_entry *tt_common_entry = entry_ptr;

  	if (tt_common_entry->flags & TT_CLIENT_NEW)

  		return 0;
  	return 1;
  }

  static int tt_global_valid_entry(const void *entry_ptr, const void *data_ptr)
  {

  	const struct tt_common_entry *tt_common_entry = entry_ptr;
  	const struct tt_global_entry *tt_global_entry;

  	const struct orig_node *orig_node = data_ptr;

  	if (tt_common_entry->flags & TT_CLIENT_ROAM)

  		return 0;

  	tt_global_entry = container_of(tt_common_entry, struct tt_global_entry,
  				       common);

  	return (tt_global_entry->orig_node == orig_node);
  }
  
  static struct sk_buff *tt_response_fill_table(uint16_t tt_len, uint8_t ttvn,
  					      struct hashtable_t *hash,
  					      struct hard_iface *primary_if,
  					      int (*valid_cb)(const void *,
  							      const void *),
  					      void *cb_data)
  {

  	struct tt_common_entry *tt_common_entry;

  	struct tt_query_packet *tt_response;
  	struct tt_change *tt_change;
  	struct hlist_node *node;
  	struct hlist_head *head;
  	struct sk_buff *skb = NULL;
  	uint16_t tt_tot, tt_count;
  	ssize_t tt_query_size = sizeof(struct tt_query_packet);

  	uint32_t i;

  
  	if (tt_query_size + tt_len > primary_if->soft_iface->mtu) {
  		tt_len = primary_if->soft_iface->mtu - tt_query_size;
  		tt_len -= tt_len % sizeof(struct tt_change);
  	}
  	tt_tot = tt_len / sizeof(struct tt_change);
  
  	skb = dev_alloc_skb(tt_query_size + tt_len + ETH_HLEN);
  	if (!skb)
  		goto out;
  
  	skb_reserve(skb, ETH_HLEN);
  	tt_response = (struct tt_query_packet *)skb_put(skb,
  						     tt_query_size + tt_len);
  	tt_response->ttvn = ttvn;

  
  	tt_change = (struct tt_change *)(skb->data + tt_query_size);
  	tt_count = 0;
  
  	rcu_read_lock();
  	for (i = 0; i < hash->size; i++) {
  		head = &hash->table[i];

  		hlist_for_each_entry_rcu(tt_common_entry, node,

  					 head, hash_entry) {
  			if (tt_count == tt_tot)
  				break;

  			if ((valid_cb) && (!valid_cb(tt_common_entry, cb_data)))

  				continue;

  			memcpy(tt_change->addr, tt_common_entry->addr,
  			       ETH_ALEN);

  			tt_change->flags = NO_FLAGS;
  
  			tt_count++;
  			tt_change++;
  		}
  	}
  	rcu_read_unlock();

  	/* store in the message the number of entries we have successfully
  	 * copied */
  	tt_response->tt_data = htons(tt_count);

  out:
  	return skb;
  }

  static int send_tt_request(struct bat_priv *bat_priv,
  			   struct orig_node *dst_orig_node,
  			   uint8_t ttvn, uint16_t tt_crc, bool full_table)

  {
  	struct sk_buff *skb = NULL;
  	struct tt_query_packet *tt_request;
  	struct neigh_node *neigh_node = NULL;
  	struct hard_iface *primary_if;
  	struct tt_req_node *tt_req_node = NULL;
  	int ret = 1;
  
  	primary_if = primary_if_get_selected(bat_priv);
  	if (!primary_if)
  		goto out;
  
  	/* The new tt_req will be issued only if I'm not waiting for a
  	 * reply from the same orig_node yet */
  	tt_req_node = new_tt_req_node(bat_priv, dst_orig_node);
  	if (!tt_req_node)
  		goto out;
  
  	skb = dev_alloc_skb(sizeof(struct tt_query_packet) + ETH_HLEN);
  	if (!skb)
  		goto out;
  
  	skb_reserve(skb, ETH_HLEN);
  
  	tt_request = (struct tt_query_packet *)skb_put(skb,
  				sizeof(struct tt_query_packet));
  
  	tt_request->packet_type = BAT_TT_QUERY;
  	tt_request->version = COMPAT_VERSION;
  	memcpy(tt_request->src, primary_if->net_dev->dev_addr, ETH_ALEN);
  	memcpy(tt_request->dst, dst_orig_node->orig, ETH_ALEN);
  	tt_request->ttl = TTL;
  	tt_request->ttvn = ttvn;
  	tt_request->tt_data = tt_crc;
  	tt_request->flags = TT_REQUEST;
  
  	if (full_table)
  		tt_request->flags |= TT_FULL_TABLE;
  
  	neigh_node = orig_node_get_router(dst_orig_node);
  	if (!neigh_node)
  		goto out;
  
  	bat_dbg(DBG_TT, bat_priv, "Sending TT_REQUEST to %pM via %pM "
  		"[%c]
  ", dst_orig_node->orig, neigh_node->addr,
  		(full_table ? 'F' : '.'));
  
  	send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
  	ret = 0;
  
  out:
  	if (neigh_node)
  		neigh_node_free_ref(neigh_node);
  	if (primary_if)
  		hardif_free_ref(primary_if);
  	if (ret)
  		kfree_skb(skb);
  	if (ret && tt_req_node) {
  		spin_lock_bh(&bat_priv->tt_req_list_lock);
  		list_del(&tt_req_node->list);
  		spin_unlock_bh(&bat_priv->tt_req_list_lock);
  		kfree(tt_req_node);
  	}
  	return ret;
  }
  
  static bool send_other_tt_response(struct bat_priv *bat_priv,
  				   struct tt_query_packet *tt_request)
  {
  	struct orig_node *req_dst_orig_node = NULL, *res_dst_orig_node = NULL;
  	struct neigh_node *neigh_node = NULL;
  	struct hard_iface *primary_if = NULL;
  	uint8_t orig_ttvn, req_ttvn, ttvn;
  	int ret = false;
  	unsigned char *tt_buff;
  	bool full_table;
  	uint16_t tt_len, tt_tot;
  	struct sk_buff *skb = NULL;
  	struct tt_query_packet *tt_response;
  
  	bat_dbg(DBG_TT, bat_priv,
  		"Received TT_REQUEST from %pM for "
  		"ttvn: %u (%pM) [%c]
  ", tt_request->src,
  		tt_request->ttvn, tt_request->dst,
  		(tt_request->flags & TT_FULL_TABLE ? 'F' : '.'));
  
  	/* Let's get the orig node of the REAL destination */

  	req_dst_orig_node = orig_hash_find(bat_priv, tt_request->dst);

  	if (!req_dst_orig_node)
  		goto out;

  	res_dst_orig_node = orig_hash_find(bat_priv, tt_request->src);

  	if (!res_dst_orig_node)
  		goto out;
  
  	neigh_node = orig_node_get_router(res_dst_orig_node);
  	if (!neigh_node)
  		goto out;
  
  	primary_if = primary_if_get_selected(bat_priv);
  	if (!primary_if)
  		goto out;
  
  	orig_ttvn = (uint8_t)atomic_read(&req_dst_orig_node->last_ttvn);
  	req_ttvn = tt_request->ttvn;

  	/* I don't have the requested data */

  	if (orig_ttvn != req_ttvn ||
  	    tt_request->tt_data != req_dst_orig_node->tt_crc)
  		goto out;

  	/* If the full table has been explicitly requested */

  	if (tt_request->flags & TT_FULL_TABLE ||
  	    !req_dst_orig_node->tt_buff)
  		full_table = true;
  	else
  		full_table = false;
  
  	/* In this version, fragmentation is not implemented, then
  	 * I'll send only one packet with as much TT entries as I can */
  	if (!full_table) {
  		spin_lock_bh(&req_dst_orig_node->tt_buff_lock);
  		tt_len = req_dst_orig_node->tt_buff_len;
  		tt_tot = tt_len / sizeof(struct tt_change);
  
  		skb = dev_alloc_skb(sizeof(struct tt_query_packet) +
  				    tt_len + ETH_HLEN);
  		if (!skb)
  			goto unlock;
  
  		skb_reserve(skb, ETH_HLEN);
  		tt_response = (struct tt_query_packet *)skb_put(skb,
  				sizeof(struct tt_query_packet) + tt_len);
  		tt_response->ttvn = req_ttvn;
  		tt_response->tt_data = htons(tt_tot);
  
  		tt_buff = skb->data + sizeof(struct tt_query_packet);
  		/* Copy the last orig_node's OGM buffer */
  		memcpy(tt_buff, req_dst_orig_node->tt_buff,
  		       req_dst_orig_node->tt_buff_len);
  
  		spin_unlock_bh(&req_dst_orig_node->tt_buff_lock);
  	} else {
  		tt_len = (uint16_t)atomic_read(&req_dst_orig_node->tt_size) *
  						sizeof(struct tt_change);
  		ttvn = (uint8_t)atomic_read(&req_dst_orig_node->last_ttvn);
  
  		skb = tt_response_fill_table(tt_len, ttvn,
  					     bat_priv->tt_global_hash,
  					     primary_if, tt_global_valid_entry,
  					     req_dst_orig_node);
  		if (!skb)
  			goto out;
  
  		tt_response = (struct tt_query_packet *)skb->data;
  	}
  
  	tt_response->packet_type = BAT_TT_QUERY;
  	tt_response->version = COMPAT_VERSION;
  	tt_response->ttl = TTL;
  	memcpy(tt_response->src, req_dst_orig_node->orig, ETH_ALEN);
  	memcpy(tt_response->dst, tt_request->src, ETH_ALEN);
  	tt_response->flags = TT_RESPONSE;
  
  	if (full_table)
  		tt_response->flags |= TT_FULL_TABLE;
  
  	bat_dbg(DBG_TT, bat_priv,
  		"Sending TT_RESPONSE %pM via %pM for %pM (ttvn: %u)
  ",
  		res_dst_orig_node->orig, neigh_node->addr,
  		req_dst_orig_node->orig, req_ttvn);
  
  	send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
  	ret = true;
  	goto out;
  
  unlock:
  	spin_unlock_bh(&req_dst_orig_node->tt_buff_lock);
  
  out:
  	if (res_dst_orig_node)
  		orig_node_free_ref(res_dst_orig_node);
  	if (req_dst_orig_node)
  		orig_node_free_ref(req_dst_orig_node);
  	if (neigh_node)
  		neigh_node_free_ref(neigh_node);
  	if (primary_if)
  		hardif_free_ref(primary_if);
  	if (!ret)
  		kfree_skb(skb);
  	return ret;
  
  }
  static bool send_my_tt_response(struct bat_priv *bat_priv,
  				struct tt_query_packet *tt_request)
  {
  	struct orig_node *orig_node = NULL;
  	struct neigh_node *neigh_node = NULL;
  	struct hard_iface *primary_if = NULL;
  	uint8_t my_ttvn, req_ttvn, ttvn;
  	int ret = false;
  	unsigned char *tt_buff;
  	bool full_table;
  	uint16_t tt_len, tt_tot;
  	struct sk_buff *skb = NULL;
  	struct tt_query_packet *tt_response;
  
  	bat_dbg(DBG_TT, bat_priv,
  		"Received TT_REQUEST from %pM for "
  		"ttvn: %u (me) [%c]
  ", tt_request->src,
  		tt_request->ttvn,
  		(tt_request->flags & TT_FULL_TABLE ? 'F' : '.'));
  
  
  	my_ttvn = (uint8_t)atomic_read(&bat_priv->ttvn);
  	req_ttvn = tt_request->ttvn;

  	orig_node = orig_hash_find(bat_priv, tt_request->src);

  	if (!orig_node)
  		goto out;
  
  	neigh_node = orig_node_get_router(orig_node);
  	if (!neigh_node)
  		goto out;
  
  	primary_if = primary_if_get_selected(bat_priv);
  	if (!primary_if)
  		goto out;
  
  	/* If the full table has been explicitly requested or the gap
  	 * is too big send the whole local translation table */
  	if (tt_request->flags & TT_FULL_TABLE || my_ttvn != req_ttvn ||
  	    !bat_priv->tt_buff)
  		full_table = true;
  	else
  		full_table = false;
  
  	/* In this version, fragmentation is not implemented, then
  	 * I'll send only one packet with as much TT entries as I can */
  	if (!full_table) {
  		spin_lock_bh(&bat_priv->tt_buff_lock);
  		tt_len = bat_priv->tt_buff_len;
  		tt_tot = tt_len / sizeof(struct tt_change);
  
  		skb = dev_alloc_skb(sizeof(struct tt_query_packet) +
  				    tt_len + ETH_HLEN);
  		if (!skb)
  			goto unlock;
  
  		skb_reserve(skb, ETH_HLEN);
  		tt_response = (struct tt_query_packet *)skb_put(skb,
  				sizeof(struct tt_query_packet) + tt_len);
  		tt_response->ttvn = req_ttvn;
  		tt_response->tt_data = htons(tt_tot);
  
  		tt_buff = skb->data + sizeof(struct tt_query_packet);
  		memcpy(tt_buff, bat_priv->tt_buff,
  		       bat_priv->tt_buff_len);
  		spin_unlock_bh(&bat_priv->tt_buff_lock);
  	} else {
  		tt_len = (uint16_t)atomic_read(&bat_priv->num_local_tt) *
  						sizeof(struct tt_change);
  		ttvn = (uint8_t)atomic_read(&bat_priv->ttvn);
  
  		skb = tt_response_fill_table(tt_len, ttvn,
  					     bat_priv->tt_local_hash,

  					     primary_if, tt_local_valid_entry,
  					     NULL);

  		if (!skb)
  			goto out;
  
  		tt_response = (struct tt_query_packet *)skb->data;
  	}
  
  	tt_response->packet_type = BAT_TT_QUERY;
  	tt_response->version = COMPAT_VERSION;
  	tt_response->ttl = TTL;
  	memcpy(tt_response->src, primary_if->net_dev->dev_addr, ETH_ALEN);
  	memcpy(tt_response->dst, tt_request->src, ETH_ALEN);
  	tt_response->flags = TT_RESPONSE;
  
  	if (full_table)
  		tt_response->flags |= TT_FULL_TABLE;
  
  	bat_dbg(DBG_TT, bat_priv,
  		"Sending TT_RESPONSE to %pM via %pM [%c]
  ",
  		orig_node->orig, neigh_node->addr,
  		(tt_response->flags & TT_FULL_TABLE ? 'F' : '.'));
  
  	send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
  	ret = true;
  	goto out;
  
  unlock:
  	spin_unlock_bh(&bat_priv->tt_buff_lock);
  out:
  	if (orig_node)
  		orig_node_free_ref(orig_node);
  	if (neigh_node)
  		neigh_node_free_ref(neigh_node);
  	if (primary_if)
  		hardif_free_ref(primary_if);
  	if (!ret)
  		kfree_skb(skb);
  	/* This packet was for me, so it doesn't need to be re-routed */
  	return true;
  }
  
  bool send_tt_response(struct bat_priv *bat_priv,
  		      struct tt_query_packet *tt_request)
  {
  	if (is_my_mac(tt_request->dst))
  		return send_my_tt_response(bat_priv, tt_request);
  	else
  		return send_other_tt_response(bat_priv, tt_request);
  }
  
  static void _tt_update_changes(struct bat_priv *bat_priv,
  			       struct orig_node *orig_node,
  			       struct tt_change *tt_change,
  			       uint16_t tt_num_changes, uint8_t ttvn)
  {
  	int i;
  
  	for (i = 0; i < tt_num_changes; i++) {

  		if ((tt_change + i)->flags & TT_CLIENT_DEL)

  			tt_global_del(bat_priv, orig_node,
  				      (tt_change + i)->addr,

  				      "tt removed by changes",
  				      (tt_change + i)->flags & TT_CLIENT_ROAM);

  		else
  			if (!tt_global_add(bat_priv, orig_node,

  					   (tt_change + i)->addr, ttvn, false,
  					   (tt_change + i)->flags &
  							TT_CLIENT_WIFI))

  				/* In case of problem while storing a
  				 * global_entry, we stop the updating
  				 * procedure without committing the
  				 * ttvn change. This will avoid to send
  				 * corrupted data on tt_request
  				 */
  				return;
  	}
  }
  
  static void tt_fill_gtable(struct bat_priv *bat_priv,
  			   struct tt_query_packet *tt_response)
  {
  	struct orig_node *orig_node = NULL;
  
  	orig_node = orig_hash_find(bat_priv, tt_response->src);
  	if (!orig_node)
  		goto out;
  
  	/* Purge the old table first.. */
  	tt_global_del_orig(bat_priv, orig_node, "Received full table");
  
  	_tt_update_changes(bat_priv, orig_node,
  			   (struct tt_change *)(tt_response + 1),
  			   tt_response->tt_data, tt_response->ttvn);
  
  	spin_lock_bh(&orig_node->tt_buff_lock);
  	kfree(orig_node->tt_buff);
  	orig_node->tt_buff_len = 0;
  	orig_node->tt_buff = NULL;
  	spin_unlock_bh(&orig_node->tt_buff_lock);
  
  	atomic_set(&orig_node->last_ttvn, tt_response->ttvn);
  
  out:
  	if (orig_node)
  		orig_node_free_ref(orig_node);
  }

  static void tt_update_changes(struct bat_priv *bat_priv,
  			      struct orig_node *orig_node,
  			      uint16_t tt_num_changes, uint8_t ttvn,
  			      struct tt_change *tt_change)

  {
  	_tt_update_changes(bat_priv, orig_node, tt_change, tt_num_changes,
  			   ttvn);
  
  	tt_save_orig_buffer(bat_priv, orig_node, (unsigned char *)tt_change,
  			    tt_num_changes);
  	atomic_set(&orig_node->last_ttvn, ttvn);
  }
  
  bool is_my_client(struct bat_priv *bat_priv, const uint8_t *addr)
  {

  	struct tt_local_entry *tt_local_entry = NULL;
  	bool ret = false;

  	tt_local_entry = tt_local_hash_find(bat_priv, addr);

  	if (!tt_local_entry)
  		goto out;

  	/* Check if the client has been logically deleted (but is kept for
  	 * consistency purpose) */

  	if (tt_local_entry->common.flags & TT_CLIENT_PENDING)

  		goto out;

  	ret = true;
  out:

  	if (tt_local_entry)

  		tt_local_entry_free_ref(tt_local_entry);
  	return ret;

  }
  
  void handle_tt_response(struct bat_priv *bat_priv,
  			struct tt_query_packet *tt_response)
  {
  	struct tt_req_node *node, *safe;
  	struct orig_node *orig_node = NULL;
  
  	bat_dbg(DBG_TT, bat_priv, "Received TT_RESPONSE from %pM for "
  		"ttvn %d t_size: %d [%c]
  ",
  		tt_response->src, tt_response->ttvn,
  		tt_response->tt_data,
  		(tt_response->flags & TT_FULL_TABLE ? 'F' : '.'));
  
  	orig_node = orig_hash_find(bat_priv, tt_response->src);
  	if (!orig_node)
  		goto out;
  
  	if (tt_response->flags & TT_FULL_TABLE)
  		tt_fill_gtable(bat_priv, tt_response);
  	else
  		tt_update_changes(bat_priv, orig_node, tt_response->tt_data,
  				  tt_response->ttvn,
  				  (struct tt_change *)(tt_response + 1));
  
  	/* Delete the tt_req_node from pending tt_requests list */
  	spin_lock_bh(&bat_priv->tt_req_list_lock);
  	list_for_each_entry_safe(node, safe, &bat_priv->tt_req_list, list) {
  		if (!compare_eth(node->addr, tt_response->src))
  			continue;
  		list_del(&node->list);
  		kfree(node);
  	}
  	spin_unlock_bh(&bat_priv->tt_req_list_lock);
  
  	/* Recalculate the CRC for this orig_node and store it */

  	orig_node->tt_crc = tt_global_crc(bat_priv, orig_node);

  	/* Roaming phase is over: tables are in sync again. I can
  	 * unset the flag */
  	orig_node->tt_poss_change = false;

  out:
  	if (orig_node)
  		orig_node_free_ref(orig_node);
  }
  
  int tt_init(struct bat_priv *bat_priv)
  {
  	if (!tt_local_init(bat_priv))
  		return 0;
  
  	if (!tt_global_init(bat_priv))
  		return 0;
  
  	tt_start_timer(bat_priv);
  
  	return 1;
  }

  static void tt_roam_list_free(struct bat_priv *bat_priv)

  {

  	struct tt_roam_node *node, *safe;

  	spin_lock_bh(&bat_priv->tt_roam_list_lock);

  	list_for_each_entry_safe(node, safe, &bat_priv->tt_roam_list, list) {
  		list_del(&node->list);
  		kfree(node);
  	}
  
  	spin_unlock_bh(&bat_priv->tt_roam_list_lock);
  }
  
  static void tt_roam_purge(struct bat_priv *bat_priv)
  {
  	struct tt_roam_node *node, *safe;
  
  	spin_lock_bh(&bat_priv->tt_roam_list_lock);
  	list_for_each_entry_safe(node, safe, &bat_priv->tt_roam_list, list) {
  		if (!is_out_of_time(node->first_time,
  				    ROAMING_MAX_TIME * 1000))
  			continue;
  
  		list_del(&node->list);
  		kfree(node);
  	}
  	spin_unlock_bh(&bat_priv->tt_roam_list_lock);
  }
  
  /* This function checks whether the client already reached the
   * maximum number of possible roaming phases. In this case the ROAMING_ADV
   * will not be sent.
   *
   * returns true if the ROAMING_ADV can be sent, false otherwise */
  static bool tt_check_roam_count(struct bat_priv *bat_priv,
  				uint8_t *client)
  {
  	struct tt_roam_node *tt_roam_node;
  	bool ret = false;
  
  	spin_lock_bh(&bat_priv->tt_roam_list_lock);
  	/* The new tt_req will be issued only if I'm not waiting for a
  	 * reply from the same orig_node yet */
  	list_for_each_entry(tt_roam_node, &bat_priv->tt_roam_list, list) {
  		if (!compare_eth(tt_roam_node->addr, client))
  			continue;
  
  		if (is_out_of_time(tt_roam_node->first_time,
  				   ROAMING_MAX_TIME * 1000))
  			continue;
  
  		if (!atomic_dec_not_zero(&tt_roam_node->counter))
  			/* Sorry, you roamed too many times! */
  			goto unlock;
  		ret = true;
  		break;
  	}
  
  	if (!ret) {
  		tt_roam_node = kmalloc(sizeof(*tt_roam_node), GFP_ATOMIC);
  		if (!tt_roam_node)
  			goto unlock;
  
  		tt_roam_node->first_time = jiffies;
  		atomic_set(&tt_roam_node->counter, ROAMING_MAX_COUNT - 1);
  		memcpy(tt_roam_node->addr, client, ETH_ALEN);
  
  		list_add(&tt_roam_node->list, &bat_priv->tt_roam_list);
  		ret = true;
  	}
  
  unlock:
  	spin_unlock_bh(&bat_priv->tt_roam_list_lock);
  	return ret;
  }
  
  void send_roam_adv(struct bat_priv *bat_priv, uint8_t *client,
  		   struct orig_node *orig_node)
  {
  	struct neigh_node *neigh_node = NULL;
  	struct sk_buff *skb = NULL;
  	struct roam_adv_packet *roam_adv_packet;
  	int ret = 1;
  	struct hard_iface *primary_if;
  
  	/* before going on we have to check whether the client has
  	 * already roamed to us too many times */
  	if (!tt_check_roam_count(bat_priv, client))
  		goto out;
  
  	skb = dev_alloc_skb(sizeof(struct roam_adv_packet) + ETH_HLEN);
  	if (!skb)
  		goto out;
  
  	skb_reserve(skb, ETH_HLEN);
  
  	roam_adv_packet = (struct roam_adv_packet *)skb_put(skb,
  					sizeof(struct roam_adv_packet));
  
  	roam_adv_packet->packet_type = BAT_ROAM_ADV;
  	roam_adv_packet->version = COMPAT_VERSION;
  	roam_adv_packet->ttl = TTL;
  	primary_if = primary_if_get_selected(bat_priv);
  	if (!primary_if)
  		goto out;
  	memcpy(roam_adv_packet->src, primary_if->net_dev->dev_addr, ETH_ALEN);
  	hardif_free_ref(primary_if);
  	memcpy(roam_adv_packet->dst, orig_node->orig, ETH_ALEN);
  	memcpy(roam_adv_packet->client, client, ETH_ALEN);
  
  	neigh_node = orig_node_get_router(orig_node);
  	if (!neigh_node)
  		goto out;
  
  	bat_dbg(DBG_TT, bat_priv,
  		"Sending ROAMING_ADV to %pM (client %pM) via %pM
  ",
  		orig_node->orig, client, neigh_node->addr);
  
  	send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
  	ret = 0;
  
  out:
  	if (neigh_node)
  		neigh_node_free_ref(neigh_node);
  	if (ret)
  		kfree_skb(skb);
  	return;

  }
  
  static void tt_purge(struct work_struct *work)
  {
  	struct delayed_work *delayed_work =
  		container_of(work, struct delayed_work, work);
  	struct bat_priv *bat_priv =
  		container_of(delayed_work, struct bat_priv, tt_work);
  
  	tt_local_purge(bat_priv);

  	tt_global_roam_purge(bat_priv);

  	tt_req_purge(bat_priv);

  	tt_roam_purge(bat_priv);

  
  	tt_start_timer(bat_priv);
  }

  
  void tt_free(struct bat_priv *bat_priv)
  {
  	cancel_delayed_work_sync(&bat_priv->tt_work);
  
  	tt_local_table_free(bat_priv);
  	tt_global_table_free(bat_priv);
  	tt_req_list_free(bat_priv);
  	tt_changes_list_free(bat_priv);
  	tt_roam_list_free(bat_priv);
  
  	kfree(bat_priv->tt_buff);
  }

  /* This function will enable or disable the specified flags for all the entries
   * in the given hash table and returns the number of modified entries */
  static uint16_t tt_set_flags(struct hashtable_t *hash, uint16_t flags,
  			     bool enable)

  {

  	uint32_t i;

  	uint16_t changed_num = 0;

  	struct hlist_head *head;
  	struct hlist_node *node;

  	struct tt_common_entry *tt_common_entry;

  
  	if (!hash)

  		goto out;

  
  	for (i = 0; i < hash->size; i++) {
  		head = &hash->table[i];
  
  		rcu_read_lock();

  		hlist_for_each_entry_rcu(tt_common_entry, node,

  					 head, hash_entry) {

  			if (enable) {
  				if ((tt_common_entry->flags & flags) == flags)
  					continue;
  				tt_common_entry->flags |= flags;
  			} else {
  				if (!(tt_common_entry->flags & flags))
  					continue;
  				tt_common_entry->flags &= ~flags;
  			}
  			changed_num++;

  		}
  		rcu_read_unlock();
  	}

  out:
  	return changed_num;

  }
  
  /* Purge out all the tt local entries marked with TT_CLIENT_PENDING */
  static void tt_local_purge_pending_clients(struct bat_priv *bat_priv)
  {
  	struct hashtable_t *hash = bat_priv->tt_local_hash;

  	struct tt_common_entry *tt_common_entry;

  	struct tt_local_entry *tt_local_entry;
  	struct hlist_node *node, *node_tmp;
  	struct hlist_head *head;
  	spinlock_t *list_lock; /* protects write access to the hash lists */

  	uint32_t i;

  
  	if (!hash)
  		return;
  
  	for (i = 0; i < hash->size; i++) {
  		head = &hash->table[i];
  		list_lock = &hash->list_locks[i];
  
  		spin_lock_bh(list_lock);

  		hlist_for_each_entry_safe(tt_common_entry, node, node_tmp,

  					  head, hash_entry) {

  			if (!(tt_common_entry->flags & TT_CLIENT_PENDING))

  				continue;
  
  			bat_dbg(DBG_TT, bat_priv, "Deleting local tt entry "

  				"(%pM): pending
  ", tt_common_entry->addr);

  
  			atomic_dec(&bat_priv->num_local_tt);
  			hlist_del_rcu(node);

  			tt_local_entry = container_of(tt_common_entry,
  						      struct tt_local_entry,
  						      common);

  			tt_local_entry_free_ref(tt_local_entry);
  		}
  		spin_unlock_bh(list_lock);
  	}
  
  }
  
  void tt_commit_changes(struct bat_priv *bat_priv)
  {

  	uint16_t changed_num = tt_set_flags(bat_priv->tt_local_hash,
  					    TT_CLIENT_NEW, false);
  	/* all the reset entries have now to be effectively counted as local
  	 * entries */
  	atomic_add(changed_num, &bat_priv->num_local_tt);

  	tt_local_purge_pending_clients(bat_priv);
  
  	/* Increment the TTVN only once per OGM interval */
  	atomic_inc(&bat_priv->ttvn);
  	bat_priv->tt_poss_change = false;
  }

  
  bool is_ap_isolated(struct bat_priv *bat_priv, uint8_t *src, uint8_t *dst)
  {
  	struct tt_local_entry *tt_local_entry = NULL;
  	struct tt_global_entry *tt_global_entry = NULL;
  	bool ret = true;
  
  	if (!atomic_read(&bat_priv->ap_isolation))
  		return false;
  
  	tt_local_entry = tt_local_hash_find(bat_priv, dst);
  	if (!tt_local_entry)
  		goto out;
  
  	tt_global_entry = tt_global_hash_find(bat_priv, src);
  	if (!tt_global_entry)
  		goto out;
  
  	if (_is_ap_isolated(tt_local_entry, tt_global_entry))
  		goto out;
  
  	ret = false;
  
  out:
  	if (tt_global_entry)
  		tt_global_entry_free_ref(tt_global_entry);
  	if (tt_local_entry)
  		tt_local_entry_free_ref(tt_local_entry);
  	return ret;
  }

  
  void tt_update_orig(struct bat_priv *bat_priv, struct orig_node *orig_node,
  		    const unsigned char *tt_buff, uint8_t tt_num_changes,
  		    uint8_t ttvn, uint16_t tt_crc)
  {
  	uint8_t orig_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
  	bool full_table = true;
  
  	/* the ttvn increased by one -> we can apply the attached changes */
  	if (ttvn - orig_ttvn == 1) {
  		/* the OGM could not contain the changes due to their size or
  		 * because they have already been sent TT_OGM_APPEND_MAX times.
  		 * In this case send a tt request */
  		if (!tt_num_changes) {
  			full_table = false;
  			goto request_table;
  		}
  
  		tt_update_changes(bat_priv, orig_node, tt_num_changes, ttvn,
  				  (struct tt_change *)tt_buff);
  
  		/* Even if we received the precomputed crc with the OGM, we
  		 * prefer to recompute it to spot any possible inconsistency
  		 * in the global table */
  		orig_node->tt_crc = tt_global_crc(bat_priv, orig_node);
  
  		/* The ttvn alone is not enough to guarantee consistency
  		 * because a single value could represent different states
  		 * (due to the wrap around). Thus a node has to check whether
  		 * the resulting table (after applying the changes) is still
  		 * consistent or not. E.g. a node could disconnect while its
  		 * ttvn is X and reconnect on ttvn = X + TTVN_MAX: in this case
  		 * checking the CRC value is mandatory to detect the
  		 * inconsistency */
  		if (orig_node->tt_crc != tt_crc)
  			goto request_table;
  
  		/* Roaming phase is over: tables are in sync again. I can
  		 * unset the flag */
  		orig_node->tt_poss_change = false;
  	} else {
  		/* if we missed more than one change or our tables are not
  		 * in sync anymore -> request fresh tt data */
  		if (ttvn != orig_ttvn || orig_node->tt_crc != tt_crc) {
  request_table:
  			bat_dbg(DBG_TT, bat_priv, "TT inconsistency for %pM. "
  				"Need to retrieve the correct information "
  				"(ttvn: %u last_ttvn: %u crc: %u last_crc: "
  				"%u num_changes: %u)
  ", orig_node->orig, ttvn,
  				orig_ttvn, tt_crc, orig_node->tt_crc,
  				tt_num_changes);
  			send_tt_request(bat_priv, orig_node, ttvn, tt_crc,
  					full_table);
  			return;
  		}
  	}
  }