net/batman-adv/bat_v.c - linux - Git at Google

 /* Copyright (C) 2013-2016 B.A.T.M.A.N. contributors:
  *
  * Linus Lüssing, Marek Lindner
  *
  * 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, see <http://www.gnu.org/licenses/>.
  */

 #include "bat_v.h"
 #include "main.h"

 #include <linux/atomic.h>
 #include <linux/bug.h>
 #include <linux/cache.h>
 #include <linux/init.h>
 #include <linux/jiffies.h>
 #include <linux/netdevice.h>
 #include <linux/rculist.h>
 #include <linux/rcupdate.h>
 #include <linux/seq_file.h>
 #include <linux/stddef.h>
 #include <linux/types.h>
 #include <linux/workqueue.h>

 #include "bat_algo.h"
 #include "bat_v_elp.h"
 #include "bat_v_ogm.h"
 #include "hard-interface.h"
 #include "hash.h"
 #include "originator.h"
 #include "packet.h"

 static void batadv_v_iface_activate(struct batadv_hard_iface *hard_iface)
 {
 	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 	struct batadv_hard_iface *primary_if;

 	primary_if = batadv_primary_if_get_selected(bat_priv);

 	if (primary_if) {
 		batadv_v_elp_iface_activate(primary_if, hard_iface);
 		batadv_hardif_put(primary_if);
 	}

 	/* B.A.T.M.A.N. V does not use any queuing mechanism, therefore it can
 	 * set the interface as ACTIVE right away, without any risk of race
 	 * condition
 	 */
 	if (hard_iface->if_status == BATADV_IF_TO_BE_ACTIVATED)
 		hard_iface->if_status = BATADV_IF_ACTIVE;
 }

 static int batadv_v_iface_enable(struct batadv_hard_iface *hard_iface)
 {
 	int ret;

 	ret = batadv_v_elp_iface_enable(hard_iface);
 	if (ret < 0)
 		return ret;

 	ret = batadv_v_ogm_iface_enable(hard_iface);
 	if (ret < 0)
 		batadv_v_elp_iface_disable(hard_iface);

 	return ret;
 }

 static void batadv_v_iface_disable(struct batadv_hard_iface *hard_iface)
 {
 	batadv_v_elp_iface_disable(hard_iface);
 }

 static void batadv_v_primary_iface_set(struct batadv_hard_iface *hard_iface)
 {
 	batadv_v_elp_primary_iface_set(hard_iface);
 	batadv_v_ogm_primary_iface_set(hard_iface);
 }

 /**
  * batadv_v_iface_update_mac - react to hard-interface MAC address change
  * @hard_iface: the modified interface
  *
  * If the modified interface is the primary one, update the originator
  * address in the ELP and OGM messages to reflect the new MAC address.
  */
 static void batadv_v_iface_update_mac(struct batadv_hard_iface *hard_iface)
 {
 	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 	struct batadv_hard_iface *primary_if;

 	primary_if = batadv_primary_if_get_selected(bat_priv);
 	if (primary_if != hard_iface)
 		goto out;

 	batadv_v_primary_iface_set(hard_iface);
 out:
 	if (primary_if)
 		batadv_hardif_put(primary_if);
 }

 static void
 batadv_v_hardif_neigh_init(struct batadv_hardif_neigh_node *hardif_neigh)
 {
 	ewma_throughput_init(&hardif_neigh->bat_v.throughput);
 	INIT_WORK(&hardif_neigh->bat_v.metric_work,
 		  batadv_v_elp_throughput_metric_update);
 }

 /**
  * batadv_v_orig_print_neigh - print neighbors for the originator table
  * @orig_node: the orig_node for which the neighbors are printed
  * @if_outgoing: outgoing interface for these entries
  * @seq: debugfs table seq_file struct
  *
  * Must be called while holding an rcu lock.
  */
 static void
 batadv_v_orig_print_neigh(struct batadv_orig_node *orig_node,
 			  struct batadv_hard_iface *if_outgoing,
 			  struct seq_file *seq)
 {
 	struct batadv_neigh_node *neigh_node;
 	struct batadv_neigh_ifinfo *n_ifinfo;

 	hlist_for_each_entry_rcu(neigh_node, &orig_node->neigh_list, list) {
 		n_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 		if (!n_ifinfo)
 			continue;

 		seq_printf(seq, " %pM (%9u.%1u)",
 			   neigh_node->addr,
 			   n_ifinfo->bat_v.throughput / 10,
 			   n_ifinfo->bat_v.throughput % 10);

 		batadv_neigh_ifinfo_put(n_ifinfo);
 	}
 }

 /**
  * batadv_v_hardif_neigh_print - print a single ELP neighbour node
  * @seq: neighbour table seq_file struct
  * @hardif_neigh: hardif neighbour information
  */
 static void
 batadv_v_hardif_neigh_print(struct seq_file *seq,
 			    struct batadv_hardif_neigh_node *hardif_neigh)
 {
 	int last_secs, last_msecs;
 	u32 throughput;

 	last_secs = jiffies_to_msecs(jiffies - hardif_neigh->last_seen) / 1000;
 	last_msecs = jiffies_to_msecs(jiffies - hardif_neigh->last_seen) % 1000;
 	throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);

 	seq_printf(seq, "%pM %4i.%03is (%9u.%1u) [%10s]\n",
 		   hardif_neigh->addr, last_secs, last_msecs, throughput / 10,
 		   throughput % 10, hardif_neigh->if_incoming->net_dev->name);
 }

 /**
  * batadv_v_neigh_print - print the single hop neighbour list
  * @bat_priv: the bat priv with all the soft interface information
  * @seq: neighbour table seq_file struct
  */
 static void batadv_v_neigh_print(struct batadv_priv *bat_priv,
 				 struct seq_file *seq)
 {
 	struct net_device *net_dev = (struct net_device *)seq->private;
 	struct batadv_hardif_neigh_node *hardif_neigh;
 	struct batadv_hard_iface *hard_iface;
 	int batman_count = 0;

 	seq_puts(seq,
 		 "  Neighbor        last-seen ( throughput) [        IF]\n");

 	rcu_read_lock();
 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 		if (hard_iface->soft_iface != net_dev)
 			continue;

 		hlist_for_each_entry_rcu(hardif_neigh,
 					 &hard_iface->neigh_list, list) {
 			batadv_v_hardif_neigh_print(seq, hardif_neigh);
 			batman_count++;
 		}
 	}
 	rcu_read_unlock();

 	if (batman_count == 0)
 		seq_puts(seq, "No batman nodes in range ...\n");
 }

 /**
  * batadv_v_orig_print - print the originator table
  * @bat_priv: the bat priv with all the soft interface information
  * @seq: debugfs table seq_file struct
  * @if_outgoing: the outgoing interface for which this should be printed
  */
 static void batadv_v_orig_print(struct batadv_priv *bat_priv,
 				struct seq_file *seq,
 				struct batadv_hard_iface *if_outgoing)
 {
 	struct batadv_neigh_node *neigh_node;
 	struct batadv_hashtable *hash = bat_priv->orig_hash;
 	int last_seen_msecs, last_seen_secs;
 	struct batadv_orig_node *orig_node;
 	struct batadv_neigh_ifinfo *n_ifinfo;
 	unsigned long last_seen_jiffies;
 	struct hlist_head *head;
 	int batman_count = 0;
 	u32 i;

 	seq_puts(seq,
 		 "  Originator      last-seen ( throughput)           Nexthop [outgoingIF]:   Potential nexthops ...\n");

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

 		rcu_read_lock();
 		hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
 			neigh_node = batadv_orig_router_get(orig_node,
 							    if_outgoing);
 			if (!neigh_node)
 				continue;

 			n_ifinfo = batadv_neigh_ifinfo_get(neigh_node,
 							   if_outgoing);
 			if (!n_ifinfo)
 				goto next;

 			last_seen_jiffies = jiffies - orig_node->last_seen;
 			last_seen_msecs = jiffies_to_msecs(last_seen_jiffies);
 			last_seen_secs = last_seen_msecs / 1000;
 			last_seen_msecs = last_seen_msecs % 1000;

 			seq_printf(seq, "%pM %4i.%03is (%9u.%1u) %pM [%10s]:",
 				   orig_node->orig, last_seen_secs,
 				   last_seen_msecs,
 				   n_ifinfo->bat_v.throughput / 10,
 				   n_ifinfo->bat_v.throughput % 10,
 				   neigh_node->addr,
 				   neigh_node->if_incoming->net_dev->name);

 			batadv_v_orig_print_neigh(orig_node, if_outgoing, seq);
 			seq_puts(seq, "\n");
 			batman_count++;

 next:
 			batadv_neigh_node_put(neigh_node);
 			if (n_ifinfo)
 				batadv_neigh_ifinfo_put(n_ifinfo);
 		}
 		rcu_read_unlock();
 	}

 	if (batman_count == 0)
 		seq_puts(seq, "No batman nodes in range ...\n");
 }

 static int batadv_v_neigh_cmp(struct batadv_neigh_node *neigh1,
 			      struct batadv_hard_iface *if_outgoing1,
 			      struct batadv_neigh_node *neigh2,
 			      struct batadv_hard_iface *if_outgoing2)
 {
 	struct batadv_neigh_ifinfo *ifinfo1, *ifinfo2;
 	int ret = 0;

 	ifinfo1 = batadv_neigh_ifinfo_get(neigh1, if_outgoing1);
 	if (WARN_ON(!ifinfo1))
 		goto err_ifinfo1;

 	ifinfo2 = batadv_neigh_ifinfo_get(neigh2, if_outgoing2);
 	if (WARN_ON(!ifinfo2))
 		goto err_ifinfo2;

 	ret = ifinfo1->bat_v.throughput - ifinfo2->bat_v.throughput;

 	batadv_neigh_ifinfo_put(ifinfo2);
 err_ifinfo2:
 	batadv_neigh_ifinfo_put(ifinfo1);
 err_ifinfo1:
 	return ret;
 }

 static bool batadv_v_neigh_is_sob(struct batadv_neigh_node *neigh1,
 				  struct batadv_hard_iface *if_outgoing1,
 				  struct batadv_neigh_node *neigh2,
 				  struct batadv_hard_iface *if_outgoing2)
 {
 	struct batadv_neigh_ifinfo *ifinfo1, *ifinfo2;
 	u32 threshold;
 	bool ret = false;

 	ifinfo1 = batadv_neigh_ifinfo_get(neigh1, if_outgoing1);
 	if (WARN_ON(!ifinfo1))
 		goto err_ifinfo1;

 	ifinfo2 = batadv_neigh_ifinfo_get(neigh2, if_outgoing2);
 	if (WARN_ON(!ifinfo2))
 		goto err_ifinfo2;

 	threshold = ifinfo1->bat_v.throughput / 4;
 	threshold = ifinfo1->bat_v.throughput - threshold;

 	ret = ifinfo2->bat_v.throughput > threshold;

 	batadv_neigh_ifinfo_put(ifinfo2);
 err_ifinfo2:
 	batadv_neigh_ifinfo_put(ifinfo1);
 err_ifinfo1:
 	return ret;
 }

 static struct batadv_algo_ops batadv_batman_v __read_mostly = {
 	.name = "BATMAN_V",
 	.iface = {
 		.activate = batadv_v_iface_activate,
 		.enable = batadv_v_iface_enable,
 		.disable = batadv_v_iface_disable,
 		.update_mac = batadv_v_iface_update_mac,
 		.primary_set = batadv_v_primary_iface_set,
 	},
 	.neigh = {
 		.hardif_init = batadv_v_hardif_neigh_init,
 		.cmp = batadv_v_neigh_cmp,
 		.is_similar_or_better = batadv_v_neigh_is_sob,
 		.print = batadv_v_neigh_print,
 	},
 	.orig = {
 		.print = batadv_v_orig_print,
 	},
 };

 /**
  * batadv_v_hardif_init - initialize the algorithm specific fields in the
  *  hard-interface object
  * @hard_iface: the hard-interface to initialize
  */
 void batadv_v_hardif_init(struct batadv_hard_iface *hard_iface)
 {
 	/* enable link throughput auto-detection by setting the throughput
 	 * override to zero
 	 */
 	atomic_set(&hard_iface->bat_v.throughput_override, 0);
 	atomic_set(&hard_iface->bat_v.elp_interval, 500);
 }

 /**
  * batadv_v_mesh_init - initialize the B.A.T.M.A.N. V private resources for a
  *  mesh
  * @bat_priv: the object representing the mesh interface to initialise
  *
  * Return: 0 on success or a negative error code otherwise
  */
 int batadv_v_mesh_init(struct batadv_priv *bat_priv)
 {
 	return batadv_v_ogm_init(bat_priv);
 }

 /**
  * batadv_v_mesh_free - free the B.A.T.M.A.N. V private resources for a mesh
  * @bat_priv: the object representing the mesh interface to free
  */
 void batadv_v_mesh_free(struct batadv_priv *bat_priv)
 {
 	batadv_v_ogm_free(bat_priv);
 }

 /**
  * batadv_v_init - B.A.T.M.A.N. V initialization function
  *
  * Description: Takes care of initializing all the subcomponents.
  * It is invoked upon module load only.
  *
  * Return: 0 on success or a negative error code otherwise
  */
 int __init batadv_v_init(void)
 {
 	int ret;

 	/* B.A.T.M.A.N. V echo location protocol packet  */
 	ret = batadv_recv_handler_register(BATADV_ELP,
 					   batadv_v_elp_packet_recv);
 	if (ret < 0)
 		return ret;

 	ret = batadv_recv_handler_register(BATADV_OGM2,
 					   batadv_v_ogm_packet_recv);
 	if (ret < 0)
 		goto elp_unregister;

 	ret = batadv_algo_register(&batadv_batman_v);
 	if (ret < 0)
 		goto ogm_unregister;

 	return ret;

 ogm_unregister:
 	batadv_recv_handler_unregister(BATADV_OGM2);

 elp_unregister:
 	batadv_recv_handler_unregister(BATADV_ELP);

 	return ret;
 }
	/* Copyright (C) 2013-2016 B.A.T.M.A.N. contributors:
	*
	* Linus Lüssing, Marek Lindner
	*
	* 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, see <http://www.gnu.org/licenses/>.
	*/

	#include "bat_v.h"
	#include "main.h"

	#include <linux/atomic.h>
	#include <linux/bug.h>
	#include <linux/cache.h>
	#include <linux/init.h>
	#include <linux/jiffies.h>
	#include <linux/netdevice.h>
	#include <linux/rculist.h>
	#include <linux/rcupdate.h>
	#include <linux/seq_file.h>
	#include <linux/stddef.h>
	#include <linux/types.h>
	#include <linux/workqueue.h>

	#include "bat_algo.h"
	#include "bat_v_elp.h"
	#include "bat_v_ogm.h"
	#include "hard-interface.h"
	#include "hash.h"
	#include "originator.h"
	#include "packet.h"

	static void batadv_v_iface_activate(struct batadv_hard_iface *hard_iface)
	{
	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
	struct batadv_hard_iface *primary_if;

	primary_if = batadv_primary_if_get_selected(bat_priv);

	if (primary_if) {
	batadv_v_elp_iface_activate(primary_if, hard_iface);
	batadv_hardif_put(primary_if);
	}

	/* B.A.T.M.A.N. V does not use any queuing mechanism, therefore it can
	* set the interface as ACTIVE right away, without any risk of race
	* condition
	*/
	if (hard_iface->if_status == BATADV_IF_TO_BE_ACTIVATED)
	hard_iface->if_status = BATADV_IF_ACTIVE;
	}

	static int batadv_v_iface_enable(struct batadv_hard_iface *hard_iface)
	{
	int ret;

	ret = batadv_v_elp_iface_enable(hard_iface);
	if (ret < 0)
	return ret;

	ret = batadv_v_ogm_iface_enable(hard_iface);
	if (ret < 0)
	batadv_v_elp_iface_disable(hard_iface);

	return ret;
	}

	static void batadv_v_iface_disable(struct batadv_hard_iface *hard_iface)
	{
	batadv_v_elp_iface_disable(hard_iface);
	}

	static void batadv_v_primary_iface_set(struct batadv_hard_iface *hard_iface)
	{
	batadv_v_elp_primary_iface_set(hard_iface);
	batadv_v_ogm_primary_iface_set(hard_iface);
	}

	/**
	* batadv_v_iface_update_mac - react to hard-interface MAC address change
	* @hard_iface: the modified interface
	*
	* If the modified interface is the primary one, update the originator
	* address in the ELP and OGM messages to reflect the new MAC address.
	*/
	static void batadv_v_iface_update_mac(struct batadv_hard_iface *hard_iface)
	{
	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
	struct batadv_hard_iface *primary_if;

	primary_if = batadv_primary_if_get_selected(bat_priv);
	if (primary_if != hard_iface)
	goto out;

	batadv_v_primary_iface_set(hard_iface);
	out:
	if (primary_if)
	batadv_hardif_put(primary_if);
	}

	static void
	batadv_v_hardif_neigh_init(struct batadv_hardif_neigh_node *hardif_neigh)
	{
	ewma_throughput_init(&hardif_neigh->bat_v.throughput);
	INIT_WORK(&hardif_neigh->bat_v.metric_work,
	batadv_v_elp_throughput_metric_update);
	}

	/**
	* batadv_v_orig_print_neigh - print neighbors for the originator table
	* @orig_node: the orig_node for which the neighbors are printed
	* @if_outgoing: outgoing interface for these entries
	* @seq: debugfs table seq_file struct
	*
	* Must be called while holding an rcu lock.
	*/
	static void
	batadv_v_orig_print_neigh(struct batadv_orig_node *orig_node,
	struct batadv_hard_iface *if_outgoing,
	struct seq_file *seq)
	{
	struct batadv_neigh_node *neigh_node;
	struct batadv_neigh_ifinfo *n_ifinfo;

	hlist_for_each_entry_rcu(neigh_node, &orig_node->neigh_list, list) {
	n_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
	if (!n_ifinfo)
	continue;

	seq_printf(seq, " %pM (%9u.%1u)",
	neigh_node->addr,
	n_ifinfo->bat_v.throughput / 10,
	n_ifinfo->bat_v.throughput % 10);

	batadv_neigh_ifinfo_put(n_ifinfo);
	}
	}

	/**
	* batadv_v_hardif_neigh_print - print a single ELP neighbour node
	* @seq: neighbour table seq_file struct
	* @hardif_neigh: hardif neighbour information
	*/
	static void
	batadv_v_hardif_neigh_print(struct seq_file *seq,
	struct batadv_hardif_neigh_node *hardif_neigh)
	{
	int last_secs, last_msecs;
	u32 throughput;

	last_secs = jiffies_to_msecs(jiffies - hardif_neigh->last_seen) / 1000;
	last_msecs = jiffies_to_msecs(jiffies - hardif_neigh->last_seen) % 1000;
	throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);

	seq_printf(seq, "%pM %4i.%03is (%9u.%1u) [%10s]\n",
	hardif_neigh->addr, last_secs, last_msecs, throughput / 10,
	throughput % 10, hardif_neigh->if_incoming->net_dev->name);
	}

	/**
	* batadv_v_neigh_print - print the single hop neighbour list
	* @bat_priv: the bat priv with all the soft interface information
	* @seq: neighbour table seq_file struct
	*/
	static void batadv_v_neigh_print(struct batadv_priv *bat_priv,
	struct seq_file *seq)
	{
	struct net_device net_dev = (struct net_device )seq->private;
	struct batadv_hardif_neigh_node *hardif_neigh;
	struct batadv_hard_iface *hard_iface;
	int batman_count = 0;

	seq_puts(seq,
	" Neighbor last-seen ( throughput) [ IF]\n");

	rcu_read_lock();
	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
	if (hard_iface->soft_iface != net_dev)
	continue;

	hlist_for_each_entry_rcu(hardif_neigh,
	&hard_iface->neigh_list, list) {
	batadv_v_hardif_neigh_print(seq, hardif_neigh);
	batman_count++;
	}
	}
	rcu_read_unlock();

	if (batman_count == 0)
	seq_puts(seq, "No batman nodes in range ...\n");
	}

	/**
	* batadv_v_orig_print - print the originator table
	* @bat_priv: the bat priv with all the soft interface information
	* @seq: debugfs table seq_file struct
	* @if_outgoing: the outgoing interface for which this should be printed
	*/
	static void batadv_v_orig_print(struct batadv_priv *bat_priv,
	struct seq_file *seq,
	struct batadv_hard_iface *if_outgoing)
	{
	struct batadv_neigh_node *neigh_node;
	struct batadv_hashtable *hash = bat_priv->orig_hash;
	int last_seen_msecs, last_seen_secs;
	struct batadv_orig_node *orig_node;
	struct batadv_neigh_ifinfo *n_ifinfo;
	unsigned long last_seen_jiffies;
	struct hlist_head *head;
	int batman_count = 0;
	u32 i;

	seq_puts(seq,
	" Originator last-seen ( throughput) Nexthop [outgoingIF]: Potential nexthops ...\n");

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

	rcu_read_lock();
	hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
	neigh_node = batadv_orig_router_get(orig_node,
	if_outgoing);
	if (!neigh_node)
	continue;

	n_ifinfo = batadv_neigh_ifinfo_get(neigh_node,
	if_outgoing);
	if (!n_ifinfo)
	goto next;

	last_seen_jiffies = jiffies - orig_node->last_seen;
	last_seen_msecs = jiffies_to_msecs(last_seen_jiffies);
	last_seen_secs = last_seen_msecs / 1000;
	last_seen_msecs = last_seen_msecs % 1000;

	seq_printf(seq, "%pM %4i.%03is (%9u.%1u) %pM [%10s]:",
	orig_node->orig, last_seen_secs,
	last_seen_msecs,
	n_ifinfo->bat_v.throughput / 10,
	n_ifinfo->bat_v.throughput % 10,
	neigh_node->addr,
	neigh_node->if_incoming->net_dev->name);

	batadv_v_orig_print_neigh(orig_node, if_outgoing, seq);
	seq_puts(seq, "\n");
	batman_count++;

	next:
	batadv_neigh_node_put(neigh_node);
	if (n_ifinfo)
	batadv_neigh_ifinfo_put(n_ifinfo);
	}
	rcu_read_unlock();
	}

	if (batman_count == 0)
	seq_puts(seq, "No batman nodes in range ...\n");
	}

	static int batadv_v_neigh_cmp(struct batadv_neigh_node *neigh1,
	struct batadv_hard_iface *if_outgoing1,
	struct batadv_neigh_node *neigh2,
	struct batadv_hard_iface *if_outgoing2)
	{
	struct batadv_neigh_ifinfo ifinfo1, ifinfo2;
	int ret = 0;

	ifinfo1 = batadv_neigh_ifinfo_get(neigh1, if_outgoing1);
	if (WARN_ON(!ifinfo1))
	goto err_ifinfo1;

	ifinfo2 = batadv_neigh_ifinfo_get(neigh2, if_outgoing2);
	if (WARN_ON(!ifinfo2))
	goto err_ifinfo2;

	ret = ifinfo1->bat_v.throughput - ifinfo2->bat_v.throughput;

	batadv_neigh_ifinfo_put(ifinfo2);
	err_ifinfo2:
	batadv_neigh_ifinfo_put(ifinfo1);
	err_ifinfo1:
	return ret;
	}

	static bool batadv_v_neigh_is_sob(struct batadv_neigh_node *neigh1,
	struct batadv_hard_iface *if_outgoing1,
	struct batadv_neigh_node *neigh2,
	struct batadv_hard_iface *if_outgoing2)
	{
	struct batadv_neigh_ifinfo ifinfo1, ifinfo2;
	u32 threshold;
	bool ret = false;

	ifinfo1 = batadv_neigh_ifinfo_get(neigh1, if_outgoing1);
	if (WARN_ON(!ifinfo1))
	goto err_ifinfo1;

	ifinfo2 = batadv_neigh_ifinfo_get(neigh2, if_outgoing2);
	if (WARN_ON(!ifinfo2))
	goto err_ifinfo2;

	threshold = ifinfo1->bat_v.throughput / 4;
	threshold = ifinfo1->bat_v.throughput - threshold;

	ret = ifinfo2->bat_v.throughput > threshold;

	batadv_neigh_ifinfo_put(ifinfo2);
	err_ifinfo2:
	batadv_neigh_ifinfo_put(ifinfo1);
	err_ifinfo1:
	return ret;
	}

	static struct batadv_algo_ops batadv_batman_v __read_mostly = {
	.name = "BATMAN_V",
	.iface = {
	.activate = batadv_v_iface_activate,
	.enable = batadv_v_iface_enable,
	.disable = batadv_v_iface_disable,
	.update_mac = batadv_v_iface_update_mac,
	.primary_set = batadv_v_primary_iface_set,
	},
	.neigh = {
	.hardif_init = batadv_v_hardif_neigh_init,
	.cmp = batadv_v_neigh_cmp,
	.is_similar_or_better = batadv_v_neigh_is_sob,
	.print = batadv_v_neigh_print,
	},
	.orig = {
	.print = batadv_v_orig_print,
	},
	};

	/**
	* batadv_v_hardif_init - initialize the algorithm specific fields in the
	* hard-interface object
	* @hard_iface: the hard-interface to initialize
	*/
	void batadv_v_hardif_init(struct batadv_hard_iface *hard_iface)
	{
	/* enable link throughput auto-detection by setting the throughput
	* override to zero
	*/
	atomic_set(&hard_iface->bat_v.throughput_override, 0);
	atomic_set(&hard_iface->bat_v.elp_interval, 500);
	}

	/**
	* batadv_v_mesh_init - initialize the B.A.T.M.A.N. V private resources for a
	* mesh
	* @bat_priv: the object representing the mesh interface to initialise
	*
	* Return: 0 on success or a negative error code otherwise
	*/
	int batadv_v_mesh_init(struct batadv_priv *bat_priv)
	{
	return batadv_v_ogm_init(bat_priv);
	}

	/**
	* batadv_v_mesh_free - free the B.A.T.M.A.N. V private resources for a mesh
	* @bat_priv: the object representing the mesh interface to free
	*/
	void batadv_v_mesh_free(struct batadv_priv *bat_priv)
	{
	batadv_v_ogm_free(bat_priv);
	}

	/**
	* batadv_v_init - B.A.T.M.A.N. V initialization function
	*
	* Description: Takes care of initializing all the subcomponents.
	* It is invoked upon module load only.
	*
	* Return: 0 on success or a negative error code otherwise
	*/
	int __init batadv_v_init(void)
	{
	int ret;

	/* B.A.T.M.A.N. V echo location protocol packet */
	ret = batadv_recv_handler_register(BATADV_ELP,
	batadv_v_elp_packet_recv);
	if (ret < 0)
	return ret;

	ret = batadv_recv_handler_register(BATADV_OGM2,
	batadv_v_ogm_packet_recv);
	if (ret < 0)
	goto elp_unregister;

	ret = batadv_algo_register(&batadv_batman_v);
	if (ret < 0)
	goto ogm_unregister;

	return ret;

	ogm_unregister:
	batadv_recv_handler_unregister(BATADV_OGM2);

	elp_unregister:
	batadv_recv_handler_unregister(BATADV_ELP);

	return ret;
	}