originator.c

// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) B.A.T.M.A.N. contributors:
 *
 * Marek Lindner, Simon Wunderlich
 */

#include "originator.h"
#include "main.h"

#include <linux/atomic.h>
#include <linux/container_of.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/etherdevice.h>
#include <linux/gfp.h>
#include <linux/if_vlan.h>
#include <linux/jiffies.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/lockdep.h>
#include <linux/netdevice.h>
#include <linux/netlink.h>
#include <linux/rculist.h>
#include <linux/rcupdate.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/stddef.h>
#include <linux/workqueue.h>
#include <uapi/linux/batadv_packet.h>

#include "distributed-arp-table.h"
#include "fragmentation.h"
#include "gateway_client.h"
#include "hard-interface.h"
#include "hash.h"
#include "log.h"
#include "multicast.h"
#include "netlink.h"
#include "routing.h"
#include "translation-table.h"

/* hash class keys */
static struct lock_class_key batadv_orig_hash_lock_class_key;

/**
 * batadv_orig_hash_find() - Find and return originator from orig_hash
 * @bat_priv: the bat priv with all the mesh interface information
 * @data: mac address of the originator
 *
 * Return: orig_node (with increased refcnt), NULL on errors
 */
struct batadv_orig_node *
batadv_orig_hash_find(struct batadv_priv *bat_priv, const void *data)
{
	struct batadv_hashtable *hash = bat_priv->orig_hash;
	struct hlist_head *head;
	struct batadv_orig_node *orig_node, *orig_node_tmp = NULL;
	int index;

	if (!hash)
		return NULL;

	index = batadv_choose_orig(data, hash->size);
	head = &hash->table[index];

	rcu_read_lock();
	hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
		if (!batadv_compare_eth(orig_node, data))
			continue;

		if (!kref_get_unless_zero(&orig_node->refcount))
			continue;

		orig_node_tmp = orig_node;
		break;
	}
	rcu_read_unlock();

	return orig_node_tmp;
}

static void batadv_purge_orig(struct work_struct *work);

/**
 * batadv_compare_orig() - comparing function used in the originator hash table
 * @node: node in the local table
 * @data2: second object to compare the node to
 *
 * Return: true if they are the same originator
 */
bool batadv_compare_orig(const struct hlist_node *node, const void *data2)
{
	const void *data1 = container_of(node, struct batadv_orig_node,
					 hash_entry);

	return batadv_compare_eth(data1, data2);
}

/**
 * batadv_orig_node_vlan_get() - get an orig_node_vlan object
 * @orig_node: the originator serving the VLAN
 * @vid: the VLAN identifier
 *
 * Return: the vlan object identified by vid and belonging to orig_node or NULL
 * if it does not exist.
 */
struct batadv_orig_node_vlan *
batadv_orig_node_vlan_get(struct batadv_orig_node *orig_node,
			  unsigned short vid)
{
	struct batadv_orig_node_vlan *vlan = NULL, *tmp;

	rcu_read_lock();
	hlist_for_each_entry_rcu(tmp, &orig_node->vlan_list, list) {
		if (tmp->vid != vid)
			continue;

		if (!kref_get_unless_zero(&tmp->refcount))
			continue;

		vlan = tmp;

		break;
	}
	rcu_read_unlock();

	return vlan;
}

/**
 * batadv_vlan_id_valid() - check if vlan id is in valid batman-adv encoding
 * @vid: the VLAN identifier
 *
 * Return: true when either no vlan is set or if VLAN is in correct range,
 *  false otherwise
 */
static bool batadv_vlan_id_valid(unsigned short vid)
{
	unsigned short non_vlan = vid & ~(BATADV_VLAN_HAS_TAG | VLAN_VID_MASK);

	if (vid == 0)
		return true;

	if (!(vid & BATADV_VLAN_HAS_TAG))
		return false;

	if (non_vlan)
		return false;

	return true;
}

/**
 * batadv_orig_node_vlan_new() - search and possibly create an orig_node_vlan
 *  object
 * @orig_node: the originator serving the VLAN
 * @vid: the VLAN identifier
 *
 * Return: NULL in case of failure or the vlan object identified by vid and
 * belonging to orig_node otherwise. The object is created and added to the list
 * if it does not exist.
 *
 * The object is returned with refcounter increased by 1.
 */
struct batadv_orig_node_vlan *
batadv_orig_node_vlan_new(struct batadv_orig_node *orig_node,
			  unsigned short vid)
{
	struct batadv_orig_node_vlan *vlan;

	if (!batadv_vlan_id_valid(vid))
		return NULL;

	spin_lock_bh(&orig_node->vlan_list_lock);

	/* first look if an object for this vid already exists */
	vlan = batadv_orig_node_vlan_get(orig_node, vid);
	if (vlan)
		goto out;

	vlan = kzalloc(sizeof(*vlan), GFP_ATOMIC);
	if (!vlan)
		goto out;

	kref_init(&vlan->refcount);
	vlan->vid = vid;

	kref_get(&vlan->refcount);
	hlist_add_head_rcu(&vlan->list, &orig_node->vlan_list);

out:
	spin_unlock_bh(&orig_node->vlan_list_lock);

	return vlan;
}

/**
 * batadv_orig_node_vlan_release() - release originator-vlan object from lists
 *  and queue for free after rcu grace period
 * @ref: kref pointer of the originator-vlan object
 */
void batadv_orig_node_vlan_release(struct kref *ref)
{
	struct batadv_orig_node_vlan *orig_vlan;

	orig_vlan = container_of(ref, struct batadv_orig_node_vlan, refcount);

	kfree_rcu(orig_vlan, rcu);
}

/**
 * batadv_originator_init() - Initialize all originator structures
 * @bat_priv: the bat priv with all the mesh interface information
 *
 * Return: 0 on success or negative error number in case of failure
 */
int batadv_originator_init(struct batadv_priv *bat_priv)
{
	if (bat_priv->orig_hash)
		return 0;

	bat_priv->orig_hash = batadv_hash_new(1024);

	if (!bat_priv->orig_hash)
		goto err;

	batadv_hash_set_lock_class(bat_priv->orig_hash,
				   &batadv_orig_hash_lock_class_key);

	INIT_DELAYED_WORK(&bat_priv->orig_work, batadv_purge_orig);
	queue_delayed_work(batadv_event_workqueue,
			   &bat_priv->orig_work,
			   msecs_to_jiffies(BATADV_ORIG_WORK_PERIOD));

	return 0;

err:
	return -ENOMEM;
}

/**
 * batadv_neigh_ifinfo_release() - release neigh_ifinfo from lists and queue for
 *  free after rcu grace period
 * @ref: kref pointer of the neigh_ifinfo
 */
void batadv_neigh_ifinfo_release(struct kref *ref)
{
	struct batadv_neigh_ifinfo *neigh_ifinfo;

	neigh_ifinfo = container_of(ref, struct batadv_neigh_ifinfo, refcount);

	if (neigh_ifinfo->if_outgoing != BATADV_IF_DEFAULT)
		batadv_hardif_put(neigh_ifinfo->if_outgoing);

	kfree_rcu(neigh_ifinfo, rcu);
}

/**
 * batadv_hardif_neigh_release() - release hardif neigh node from lists and
 *  queue for free after rcu grace period
 * @ref: kref pointer of the neigh_node
 */
void batadv_hardif_neigh_release(struct kref *ref)
{
	struct batadv_hardif_neigh_node *hardif_neigh;

	hardif_neigh = container_of(ref, struct batadv_hardif_neigh_node,
				    refcount);

	spin_lock_bh(&hardif_neigh->if_incoming->neigh_list_lock);
	hlist_del_init_rcu(&hardif_neigh->list);
	spin_unlock_bh(&hardif_neigh->if_incoming->neigh_list_lock);

	batadv_hardif_put(hardif_neigh->if_incoming);
	kfree_rcu(hardif_neigh, rcu);
}

/**
 * batadv_neigh_node_release() - release neigh_node from lists and queue for
 *  free after rcu grace period
 * @ref: kref pointer of the neigh_node
 */
void batadv_neigh_node_release(struct kref *ref)
{
	struct hlist_node *node_tmp;
	struct batadv_neigh_node *neigh_node;
	struct batadv_neigh_ifinfo *neigh_ifinfo;

	neigh_node = container_of(ref, struct batadv_neigh_node, refcount);

	hlist_for_each_entry_safe(neigh_ifinfo, node_tmp,
				  &neigh_node->ifinfo_list, list) {
		batadv_neigh_ifinfo_put(neigh_ifinfo);
	}

	batadv_hardif_neigh_put(neigh_node->hardif_neigh);

	batadv_hardif_put(neigh_node->if_incoming);

	kfree_rcu(neigh_node, rcu);
}

/**
 * batadv_orig_router_get() - router to the originator depending on iface
 * @orig_node: the orig node for the router
 * @if_outgoing: the interface where the payload packet has been received or
 *  the OGM should be sent to
 *
 * Return: the neighbor which should be the router for this orig_node/iface.
 *
 * The object is returned with refcounter increased by 1.
 */
struct batadv_neigh_node *
batadv_orig_router_get(struct batadv_orig_node *orig_node,
		       const struct batadv_hard_iface *if_outgoing)
{
	struct batadv_orig_ifinfo *orig_ifinfo;
	struct batadv_neigh_node *router = NULL;

	rcu_read_lock();
	hlist_for_each_entry_rcu(orig_ifinfo, &orig_node->ifinfo_list, list) {
		if (orig_ifinfo->if_outgoing != if_outgoing)
			continue;

		router = rcu_dereference(orig_ifinfo->router);
		break;
	}

	if (router && !kref_get_unless_zero(&router->refcount))
		router = NULL;

	rcu_read_unlock();
	return router;
}

/**
 * batadv_orig_to_router() - get next hop neighbor to an orig address
 * @bat_priv: the bat priv with all the mesh interface information
 * @orig_addr: the originator MAC address to search the best next hop router for
 * @if_outgoing: the interface where the payload packet has been received or
 *  the OGM should be sent to
 *
 * Return: A neighbor node which is the best router towards the given originator
 * address.
 */
struct batadv_neigh_node *
batadv_orig_to_router(struct batadv_priv *bat_priv, u8 *orig_addr,
		      struct batadv_hard_iface *if_outgoing)
{
	struct batadv_neigh_node *neigh_node;
	struct batadv_orig_node *orig_node;

	orig_node = batadv_orig_hash_find(bat_priv, orig_addr);
	if (!orig_node)
		return NULL;

	neigh_node = batadv_find_router(bat_priv, orig_node, if_outgoing);
	batadv_orig_node_put(orig_node);

	return neigh_node;
}

/**
 * batadv_orig_ifinfo_get() - find the ifinfo from an orig_node
 * @orig_node: the orig node to be queried
 * @if_outgoing: the interface for which the ifinfo should be acquired
 *
 * Return: the requested orig_ifinfo or NULL if not found.
 *
 * The object is returned with refcounter increased by 1.
 */
struct batadv_orig_ifinfo *
batadv_orig_ifinfo_get(struct batadv_orig_node *orig_node,
		       struct batadv_hard_iface *if_outgoing)
{
	struct batadv_orig_ifinfo *tmp, *orig_ifinfo = NULL;

	rcu_read_lock();
	hlist_for_each_entry_rcu(tmp, &orig_node->ifinfo_list,
				 list) {
		if (tmp->if_outgoing != if_outgoing)
			continue;

		if (!kref_get_unless_zero(&tmp->refcount))
			continue;

		orig_ifinfo = tmp;
		break;
	}
	rcu_read_unlock();

	return orig_ifinfo;
}

/**
 * batadv_orig_ifinfo_new() - search and possibly create an orig_ifinfo object
 * @orig_node: the orig node to be queried
 * @if_outgoing: the interface for which the ifinfo should be acquired
 *
 * Return: NULL in case of failure or the orig_ifinfo object for the if_outgoing
 * interface otherwise. The object is created and added to the list
 * if it does not exist.
 *
 * The object is returned with refcounter increased by 1.
 */
struct batadv_orig_ifinfo *
batadv_orig_ifinfo_new(struct batadv_orig_node *orig_node,
		       struct batadv_hard_iface *if_outgoing)
{
	struct batadv_orig_ifinfo *orig_ifinfo;
	unsigned long reset_time;

	spin_lock_bh(&orig_node->neigh_list_lock);

	orig_ifinfo = batadv_orig_ifinfo_get(orig_node, if_outgoing);
	if (orig_ifinfo)
		goto out;

	orig_ifinfo = kzalloc(sizeof(*orig_ifinfo), GFP_ATOMIC);
	if (!orig_ifinfo)
		goto out;

	if (if_outgoing != BATADV_IF_DEFAULT)
		kref_get(&if_outgoing->refcount);

	reset_time = jiffies - 1;
	reset_time -= msecs_to_jiffies(BATADV_RESET_PROTECTION_MS);
	orig_ifinfo->batman_seqno_reset = reset_time;
	orig_ifinfo->if_outgoing = if_outgoing;
	INIT_HLIST_NODE(&orig_ifinfo->list);
	kref_init(&orig_ifinfo->refcount);

	kref_get(&orig_ifinfo->refcount);
	hlist_add_head_rcu(&orig_ifinfo->list,
			   &orig_node->ifinfo_list);
out:
	spin_unlock_bh(&orig_node->neigh_list_lock);
	return orig_ifinfo;
}

/**
 * batadv_neigh_ifinfo_get() - find the ifinfo from an neigh_node
 * @neigh: the neigh node to be queried
 * @if_outgoing: the interface for which the ifinfo should be acquired
 *
 * The object is returned with refcounter increased by 1.
 *
 * Return: the requested neigh_ifinfo or NULL if not found
 */
struct batadv_neigh_ifinfo *
batadv_neigh_ifinfo_get(struct batadv_neigh_node *neigh,
			struct batadv_hard_iface *if_outgoing)
{
	struct batadv_neigh_ifinfo *neigh_ifinfo = NULL,
				   *tmp_neigh_ifinfo;

	rcu_read_lock();
	hlist_for_each_entry_rcu(tmp_neigh_ifinfo, &neigh->ifinfo_list,
				 list) {
		if (tmp_neigh_ifinfo->if_outgoing != if_outgoing)
			continue;

		if (!kref_get_unless_zero(&tmp_neigh_ifinfo->refcount))
			continue;

		neigh_ifinfo = tmp_neigh_ifinfo;
		break;
	}
	rcu_read_unlock();

	return neigh_ifinfo;
}

/**
 * batadv_neigh_ifinfo_new() - search and possibly create an neigh_ifinfo object
 * @neigh: the neigh node to be queried
 * @if_outgoing: the interface for which the ifinfo should be acquired
 *
 * Return: NULL in case of failure or the neigh_ifinfo object for the
 * if_outgoing interface otherwise. The object is created and added to the list
 * if it does not exist.
 *
 * The object is returned with refcounter increased by 1.
 */
struct batadv_neigh_ifinfo *
batadv_neigh_ifinfo_new(struct batadv_neigh_node *neigh,
			struct batadv_hard_iface *if_outgoing)
{
	struct batadv_neigh_ifinfo *neigh_ifinfo;

	spin_lock_bh(&neigh->ifinfo_lock);

	neigh_ifinfo = batadv_neigh_ifinfo_get(neigh, if_outgoing);
	if (neigh_ifinfo)
		goto out;

	neigh_ifinfo = kzalloc(sizeof(*neigh_ifinfo), GFP_ATOMIC);
	if (!neigh_ifinfo)
		goto out;

	if (if_outgoing)
		kref_get(&if_outgoing->refcount);

	INIT_HLIST_NODE(&neigh_ifinfo->list);
	kref_init(&neigh_ifinfo->refcount);
	neigh_ifinfo->if_outgoing = if_outgoing;

	kref_get(&neigh_ifinfo->refcount);
	hlist_add_head_rcu(&neigh_ifinfo->list, &neigh->ifinfo_list);

out:
	spin_unlock_bh(&neigh->ifinfo_lock);

	return neigh_ifinfo;
}

/**
 * batadv_neigh_node_get() - retrieve a neighbour from the list
 * @orig_node: originator which the neighbour belongs to
 * @hard_iface: the interface where this neighbour is connected to
 * @addr: the address of the neighbour
 *
 * Looks for and possibly returns a neighbour belonging to this originator list
 * which is connected through the provided hard interface.
 *
 * Return: neighbor when found. Otherwise NULL
 */
static struct batadv_neigh_node *
batadv_neigh_node_get(const struct batadv_orig_node *orig_node,
		      const struct batadv_hard_iface *hard_iface,
		      const u8 *addr)
{
	struct batadv_neigh_node *tmp_neigh_node, *res = NULL;

	rcu_read_lock();
	hlist_for_each_entry_rcu(tmp_neigh_node, &orig_node->neigh_list, list) {
		if (!batadv_compare_eth(tmp_neigh_node->addr, addr))
			continue;

		if (tmp_neigh_node->if_incoming != hard_iface)
			continue;

		if (!kref_get_unless_zero(&tmp_neigh_node->refcount))
			continue;

		res = tmp_neigh_node;
		break;
	}
	rcu_read_unlock();

	return res;
}

/**
 * batadv_hardif_neigh_create() - create a hardif neighbour node
 * @hard_iface: the interface this neighbour is connected to
 * @neigh_addr: the interface address of the neighbour to retrieve
 * @orig_node: originator object representing the neighbour
 *
 * Return: the hardif neighbour node if found or created or NULL otherwise.
 */
static struct batadv_hardif_neigh_node *
batadv_hardif_neigh_create(struct batadv_hard_iface *hard_iface,
			   const u8 *neigh_addr,
			   struct batadv_orig_node *orig_node)
{
	struct batadv_priv *bat_priv = netdev_priv(hard_iface->mesh_iface);
	struct batadv_hardif_neigh_node *hardif_neigh;

	spin_lock_bh(&hard_iface->neigh_list_lock);

	/* check if neighbor hasn't been added in the meantime */
	hardif_neigh = batadv_hardif_neigh_get(hard_iface, neigh_addr);
	if (hardif_neigh)
		goto out;

	hardif_neigh = kzalloc(sizeof(*hardif_neigh), GFP_ATOMIC);
	if (!hardif_neigh)
		goto out;

	kref_get(&hard_iface->refcount);
	INIT_HLIST_NODE(&hardif_neigh->list);
	ether_addr_copy(hardif_neigh->addr, neigh_addr);
	ether_addr_copy(hardif_neigh->orig, orig_node->orig);
	hardif_neigh->if_incoming = hard_iface;
	hardif_neigh->last_seen = jiffies;

	kref_init(&hardif_neigh->refcount);

	if (bat_priv->algo_ops->neigh.hardif_init)
		bat_priv->algo_ops->neigh.hardif_init(hardif_neigh);

	hlist_add_head_rcu(&hardif_neigh->list, &hard_iface->neigh_list);

out:
	spin_unlock_bh(&hard_iface->neigh_list_lock);
	return hardif_neigh;
}

/**
 * batadv_hardif_neigh_get_or_create() - retrieve or create a hardif neighbour
 *  node
 * @hard_iface: the interface this neighbour is connected to
 * @neigh_addr: the interface address of the neighbour to retrieve
 * @orig_node: originator object representing the neighbour
 *
 * Return: the hardif neighbour node if found or created or NULL otherwise.
 */
static struct batadv_hardif_neigh_node *
batadv_hardif_neigh_get_or_create(struct batadv_hard_iface *hard_iface,
				  const u8 *neigh_addr,
				  struct batadv_orig_node *orig_node)
{
	struct batadv_hardif_neigh_node *hardif_neigh;

	/* first check without locking to avoid the overhead */
	hardif_neigh = batadv_hardif_neigh_get(hard_iface, neigh_addr);
	if (hardif_neigh)
		return hardif_neigh;

	return batadv_hardif_neigh_create(hard_iface, neigh_addr, orig_node);
}

/**
 * batadv_hardif_neigh_get() - retrieve a hardif neighbour from the list
 * @hard_iface: the interface where this neighbour is connected to
 * @neigh_addr: the address of the neighbour
 *
 * Looks for and possibly returns a neighbour belonging to this hard interface.
 *
 * Return: neighbor when found. Otherwise NULL
 */
struct batadv_hardif_neigh_node *
batadv_hardif_neigh_get(const struct batadv_hard_iface *hard_iface,
			const u8 *neigh_addr)
{
	struct batadv_hardif_neigh_node *tmp_hardif_neigh, *hardif_neigh = NULL;

	rcu_read_lock();
	hlist_for_each_entry_rcu(tmp_hardif_neigh,
				 &hard_iface->neigh_list, list) {
		if (!batadv_compare_eth(tmp_hardif_neigh->addr, neigh_addr))
			continue;

		if (!kref_get_unless_zero(&tmp_hardif_neigh->refcount))
			continue;

		hardif_neigh = tmp_hardif_neigh;
		break;
	}
	rcu_read_unlock();

	return hardif_neigh;
}

/**
 * batadv_neigh_node_create() - create a neigh node object
 * @orig_node: originator object representing the neighbour
 * @hard_iface: the interface where the neighbour is connected to
 * @neigh_addr: the mac address of the neighbour interface
 *
 * Allocates a new neigh_node object and initialises all the generic fields.
 *
 * Return: the neighbour node if found or created or NULL otherwise.
 */
static struct batadv_neigh_node *
batadv_neigh_node_create(struct batadv_orig_node *orig_node,
			 struct batadv_hard_iface *hard_iface,
			 const u8 *neigh_addr)
{
	struct batadv_neigh_node *neigh_node;
	struct batadv_hardif_neigh_node *hardif_neigh = NULL;

	spin_lock_bh(&orig_node->neigh_list_lock);

	neigh_node = batadv_neigh_node_get(orig_node, hard_iface, neigh_addr);
	if (neigh_node)
		goto out;

	hardif_neigh = batadv_hardif_neigh_get_or_create(hard_iface,
							 neigh_addr, orig_node);
	if (!hardif_neigh)
		goto out;

	neigh_node = kzalloc(sizeof(*neigh_node), GFP_ATOMIC);
	if (!neigh_node)
		goto out;

	INIT_HLIST_NODE(&neigh_node->list);
	INIT_HLIST_HEAD(&neigh_node->ifinfo_list);
	spin_lock_init(&neigh_node->ifinfo_lock);

	kref_get(&hard_iface->refcount);
	ether_addr_copy(neigh_node->addr, neigh_addr);
	neigh_node->if_incoming = hard_iface;
	neigh_node->orig_node = orig_node;
	neigh_node->last_seen = jiffies;

	/* increment unique neighbor refcount */
	kref_get(&hardif_neigh->refcount);
	neigh_node->hardif_neigh = hardif_neigh;

	/* extra reference for return */
	kref_init(&neigh_node->refcount);

	kref_get(&neigh_node->refcount);
	hlist_add_head_rcu(&neigh_node->list, &orig_node->neigh_list);

	batadv_dbg(BATADV_DBG_BATMAN, orig_node->bat_priv,
		   "Creating new neighbor %pM for orig_node %pM on interface %s\n",
		   neigh_addr, orig_node->orig, hard_iface->net_dev->name);

out:
	spin_unlock_bh(&orig_node->neigh_list_lock);

	batadv_hardif_neigh_put(hardif_neigh);
	return neigh_node;
}

/**
 * batadv_neigh_node_get_or_create() - retrieve or create a neigh node object
 * @orig_node: originator object representing the neighbour
 * @hard_iface: the interface where the neighbour is connected to
 * @neigh_addr: the mac address of the neighbour interface
 *
 * Return: the neighbour node if found or created or NULL otherwise.
 */
struct batadv_neigh_node *
batadv_neigh_node_get_or_create(struct batadv_orig_node *orig_node,
				struct batadv_hard_iface *hard_iface,
				const u8 *neigh_addr)
{
	struct batadv_neigh_node *neigh_node;

	/* first check without locking to avoid the overhead */
	neigh_node = batadv_neigh_node_get(orig_node, hard_iface, neigh_addr);
	if (neigh_node)
		return neigh_node;

	return batadv_neigh_node_create(orig_node, hard_iface, neigh_addr);
}

/**
 * batadv_hardif_neigh_dump() - Dump to netlink the neighbor infos for a
 *  specific outgoing interface
 * @msg: message to dump into
 * @cb: parameters for the dump
 *
 * Return: 0 or error value
 */
int batadv_hardif_neigh_dump(struct sk_buff *msg, struct netlink_callback *cb)
{
	struct batadv_hard_iface *primary_if, *hard_iface;
	struct net_device *mesh_iface;
	struct batadv_priv *bat_priv;
	int ret;

	mesh_iface = batadv_netlink_get_meshif(cb);
	if (IS_ERR(mesh_iface))
		return PTR_ERR(mesh_iface);

	bat_priv = netdev_priv(mesh_iface);

	primary_if = batadv_primary_if_get_selected(bat_priv);
	if (!primary_if) {
		ret = -ENOENT;
		goto out_put_mesh_iface;
	}

	if (primary_if->if_status != BATADV_IF_ACTIVE) {
		ret = -ENOENT;
		goto out_put_primary_if;
	}

	hard_iface = batadv_netlink_get_hardif(bat_priv, cb);
	if (IS_ERR(hard_iface) && PTR_ERR(hard_iface) != -ENONET) {
		ret = PTR_ERR(hard_iface);
		goto out_put_primary_if;
	} else if (IS_ERR(hard_iface)) {
		/* => PTR_ERR(hard_iface) == -ENONET
		 * => no hard-iface given, ok
		 */
		hard_iface = BATADV_IF_DEFAULT;
	}

	if (!bat_priv->algo_ops->neigh.dump) {
		ret = -EOPNOTSUPP;
		goto out_put_hard_iface;
	}

	bat_priv->algo_ops->neigh.dump(msg, cb, bat_priv, hard_iface);

	ret = msg->len;

out_put_hard_iface:
	batadv_hardif_put(hard_iface);
out_put_primary_if:
	batadv_hardif_put(primary_if);
out_put_mesh_iface:
	dev_put(mesh_iface);

	return ret;
}

/**
 * batadv_orig_ifinfo_release() - release orig_ifinfo from lists and queue for
 *  free after rcu grace period
 * @ref: kref pointer of the orig_ifinfo
 */
void batadv_orig_ifinfo_release(struct kref *ref)
{
	struct batadv_orig_ifinfo *orig_ifinfo;
	struct batadv_neigh_node *router;

	orig_ifinfo = container_of(ref, struct batadv_orig_ifinfo, refcount);

	if (orig_ifinfo->if_outgoing != BATADV_IF_DEFAULT)
		batadv_hardif_put(orig_ifinfo->if_outgoing);

	/* this is the last reference to this object */
	router = rcu_dereference_protected(orig_ifinfo->router, true);
	batadv_neigh_node_put(router);

	kfree_rcu(orig_ifinfo, rcu);
}

/**
 * batadv_orig_node_free_rcu() - free the orig_node
 * @rcu: rcu pointer of the orig_node
 */
static void batadv_orig_node_free_rcu(struct rcu_head *rcu)
{
	struct batadv_orig_node *orig_node;

	orig_node = container_of(rcu, struct batadv_orig_node, rcu);

	batadv_mcast_purge_orig(orig_node);

	batadv_frag_purge_orig(orig_node, NULL);

	kfree(orig_node->tt_buff);
	kfree(orig_node);
}

/**
 * batadv_orig_node_release() - release orig_node from lists and queue for
 *  free after rcu grace period
 * @ref: kref pointer of the orig_node
 */
void batadv_orig_node_release(struct kref *ref)
{
	struct hlist_node *node_tmp;
	struct batadv_neigh_node *neigh_node;
	struct batadv_orig_node *orig_node;
	struct batadv_orig_ifinfo *orig_ifinfo;
	struct batadv_orig_node_vlan *vlan;
	struct batadv_orig_ifinfo *last_candidate;

	orig_node = container_of(ref, struct batadv_orig_node, refcount);

	spin_lock_bh(&orig_node->neigh_list_lock);

	/* for all neighbors towards this originator ... */
	hlist_for_each_entry_safe(neigh_node, node_tmp,
				  &orig_node->neigh_list, list) {
		hlist_del_rcu(&neigh_node->list);
		batadv_neigh_node_put(neigh_node);
	}

	hlist_for_each_entry_safe(orig_ifinfo, node_tmp,
				  &orig_node->ifinfo_list, list) {
		hlist_del_rcu(&orig_ifinfo->list);
		batadv_orig_ifinfo_put(orig_ifinfo);
	}

	last_candidate = orig_node->last_bonding_candidate;
	orig_node->last_bonding_candidate = NULL;
	spin_unlock_bh(&orig_node->neigh_list_lock);

	batadv_orig_ifinfo_put(last_candidate);

	spin_lock_bh(&orig_node->vlan_list_lock);
	hlist_for_each_entry_safe(vlan, node_tmp, &orig_node->vlan_list, list) {
		hlist_del_rcu(&vlan->list);
		batadv_orig_node_vlan_put(vlan);
	}
	spin_unlock_bh(&orig_node->vlan_list_lock);

	call_rcu(&orig_node->rcu, batadv_orig_node_free_rcu);
}

/**
 * batadv_originator_free() - Free all originator structures
 * @bat_priv: the bat priv with all the mesh interface information
 */
void batadv_originator_free(struct batadv_priv *bat_priv)
{
	struct batadv_hashtable *hash = bat_priv->orig_hash;
	struct hlist_node *node_tmp;
	struct hlist_head *head;
	spinlock_t *list_lock; /* spinlock to protect write access */
	struct batadv_orig_node *orig_node;
	u32 i;

	if (!hash)
		return;

	cancel_delayed_work_sync(&bat_priv->orig_work);

	bat_priv->orig_hash = NULL;

	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(orig_node, node_tmp,
					  head, hash_entry) {
			hlist_del_rcu(&orig_node->hash_entry);
			batadv_orig_node_put(orig_node);
		}
		spin_unlock_bh(list_lock);
	}

	batadv_hash_destroy(hash);
}

/**
 * batadv_orig_node_new() - creates a new orig_node
 * @bat_priv: the bat priv with all the mesh interface information
 * @addr: the mac address of the originator
 *
 * Creates a new originator object and initialises all the generic fields.
 * The new object is not added to the originator list.
 *
 * Return: the newly created object or NULL on failure.
 */
struct batadv_orig_node *batadv_orig_node_new(struct batadv_priv *bat_priv,
					      const u8 *addr)
{
	struct batadv_orig_node *orig_node;
	struct batadv_orig_node_vlan *vlan;
	unsigned long reset_time;
	int i;

	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
		   "Creating new originator: %pM\n", addr);

	orig_node = kzalloc(sizeof(*orig_node), GFP_ATOMIC);
	if (!orig_node)
		return NULL;

	INIT_HLIST_HEAD(&orig_node->neigh_list);
	INIT_HLIST_HEAD(&orig_node->vlan_list);
	INIT_HLIST_HEAD(&orig_node->ifinfo_list);
	spin_lock_init(&orig_node->bcast_seqno_lock);
	spin_lock_init(&orig_node->neigh_list_lock);
	spin_lock_init(&orig_node->tt_buff_lock);
	spin_lock_init(&orig_node->tt_lock);
	spin_lock_init(&orig_node->vlan_list_lock);

	/* extra reference for return */
	kref_init(&orig_node->refcount);

	orig_node->bat_priv = bat_priv;
	ether_addr_copy(orig_node->orig, addr);
	batadv_dat_init_orig_node_addr(orig_node);
	atomic_set(&orig_node->last_ttvn, 0);
	orig_node->tt_buff = NULL;
	orig_node->tt_buff_len = 0;
	orig_node->last_seen = jiffies;
	reset_time = jiffies - 1 - msecs_to_jiffies(BATADV_RESET_PROTECTION_MS);
	orig_node->bcast_seqno_reset = reset_time;

#ifdef CONFIG_BATMAN_ADV_MCAST
	orig_node->mcast_flags = BATADV_MCAST_WANT_NO_RTR4;
	orig_node->mcast_flags |= BATADV_MCAST_WANT_NO_RTR6;
	orig_node->mcast_flags |= BATADV_MCAST_HAVE_MC_PTYPE_CAPA;
	INIT_HLIST_NODE(&orig_node->mcast_want_all_unsnoopables_node);
	INIT_HLIST_NODE(&orig_node->mcast_want_all_ipv4_node);
	INIT_HLIST_NODE(&orig_node->mcast_want_all_ipv6_node);
	spin_lock_init(&orig_node->mcast_handler_lock);
#endif

	/* create a vlan object for the "untagged" LAN */
	vlan = batadv_orig_node_vlan_new(orig_node, BATADV_NO_FLAGS);
	if (!vlan)
		goto free_orig_node;
	/* batadv_orig_node_vlan_new() increases the refcounter.
	 * Immediately release vlan since it is not needed anymore in this
	 * context
	 */
	batadv_orig_node_vlan_put(vlan);

	for (i = 0; i < BATADV_FRAG_BUFFER_COUNT; i++) {
		INIT_HLIST_HEAD(&orig_node->fragments[i].fragment_list);
		spin_lock_init(&orig_node->fragments[i].lock);
		orig_node->fragments[i].size = 0;
	}

	return orig_node;
free_orig_node:
	kfree(orig_node);
	return NULL;
}

/**
 * batadv_purge_neigh_ifinfo() - purge obsolete ifinfo entries from neighbor
 * @bat_priv: the bat priv with all the mesh interface information
 * @neigh: orig node which is to be checked
 */
static void
batadv_purge_neigh_ifinfo(struct batadv_priv *bat_priv,
			  struct batadv_neigh_node *neigh)
{
	struct batadv_neigh_ifinfo *neigh_ifinfo;
	struct batadv_hard_iface *if_outgoing;
	struct hlist_node *node_tmp;

	spin_lock_bh(&neigh->ifinfo_lock);

	/* for all ifinfo objects for this neighinator */
	hlist_for_each_entry_safe(neigh_ifinfo, node_tmp,
				  &neigh->ifinfo_list, list) {
		if_outgoing = neigh_ifinfo->if_outgoing;

		/* always keep the default interface */
		if (if_outgoing == BATADV_IF_DEFAULT)
			continue;

		/* don't purge if the interface is not (going) down */
		if (if_outgoing->if_status != BATADV_IF_INACTIVE &&
		    if_outgoing->if_status != BATADV_IF_NOT_IN_USE &&
		    if_outgoing->if_status != BATADV_IF_TO_BE_REMOVED)
			continue;

		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
			   "neighbor/ifinfo purge: neighbor %pM, iface: %s\n",
			   neigh->addr, if_outgoing->net_dev->name);

		hlist_del_rcu(&neigh_ifinfo->list);
		batadv_neigh_ifinfo_put(neigh_ifinfo);
	}

	spin_unlock_bh(&neigh->ifinfo_lock);
}

/**
 * batadv_purge_orig_ifinfo() - purge obsolete ifinfo entries from originator
 * @bat_priv: the bat priv with all the mesh interface information
 * @orig_node: orig node which is to be checked
 *
 * Return: true if any ifinfo entry was purged, false otherwise.
 */
static bool
batadv_purge_orig_ifinfo(struct batadv_priv *bat_priv,
			 struct batadv_orig_node *orig_node)
{
	struct batadv_orig_ifinfo *orig_ifinfo;
	struct batadv_hard_iface *if_outgoing;
	struct hlist_node *node_tmp;
	bool ifinfo_purged = false;

	spin_lock_bh(&orig_node->neigh_list_lock);

	/* for all ifinfo objects for this originator */
	hlist_for_each_entry_safe(orig_ifinfo, node_tmp,
				  &orig_node->ifinfo_list, list) {
		if_outgoing = orig_ifinfo->if_outgoing;

		/* always keep the default interface */
		if (if_outgoing == BATADV_IF_DEFAULT)
			continue;

		/* don't purge if the interface is not (going) down */
		if (if_outgoing->if_status != BATADV_IF_INACTIVE &&
		    if_outgoing->if_status != BATADV_IF_NOT_IN_USE &&
		    if_outgoing->if_status != BATADV_IF_TO_BE_REMOVED)
			continue;

		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
			   "router/ifinfo purge: originator %pM, iface: %s\n",
			   orig_node->orig, if_outgoing->net_dev->name);

		ifinfo_purged = true;

		hlist_del_rcu(&orig_ifinfo->list);
		batadv_orig_ifinfo_put(orig_ifinfo);
		if (orig_node->last_bonding_candidate == orig_ifinfo) {
			orig_node->last_bonding_candidate = NULL;
			batadv_orig_ifinfo_put(orig_ifinfo);
		}
	}

	spin_unlock_bh(&orig_node->neigh_list_lock);

	return ifinfo_purged;
}

/**
 * batadv_purge_orig_neighbors() - purges neighbors from originator
 * @bat_priv: the bat priv with all the mesh interface information
 * @orig_node: orig node which is to be checked
 *
 * Return: true if any neighbor was purged, false otherwise
 */
static bool
batadv_purge_orig_neighbors(struct batadv_priv *bat_priv,
			    struct batadv_orig_node *orig_node)
{
	struct hlist_node *node_tmp;
	struct batadv_neigh_node *neigh_node;
	bool neigh_purged = false;
	unsigned long last_seen;
	struct batadv_hard_iface *if_incoming;

	spin_lock_bh(&orig_node->neigh_list_lock);

	/* for all neighbors towards this originator ... */
	hlist_for_each_entry_safe(neigh_node, node_tmp,
				  &orig_node->neigh_list, list) {
		last_seen = neigh_node->last_seen;
		if_incoming = neigh_node->if_incoming;

		if (batadv_has_timed_out(last_seen, BATADV_PURGE_TIMEOUT) ||
		    if_incoming->if_status == BATADV_IF_INACTIVE ||
		    if_incoming->if_status == BATADV_IF_NOT_IN_USE ||
		    if_incoming->if_status == BATADV_IF_TO_BE_REMOVED) {
			if (if_incoming->if_status == BATADV_IF_INACTIVE ||
			    if_incoming->if_status == BATADV_IF_NOT_IN_USE ||
			    if_incoming->if_status == BATADV_IF_TO_BE_REMOVED)
				batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
					   "neighbor purge: originator %pM, neighbor: %pM, iface: %s\n",
					   orig_node->orig, neigh_node->addr,
					   if_incoming->net_dev->name);
			else
				batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
					   "neighbor timeout: originator %pM, neighbor: %pM, last_seen: %u\n",
					   orig_node->orig, neigh_node->addr,
					   jiffies_to_msecs(last_seen));

			neigh_purged = true;

			hlist_del_rcu(&neigh_node->list);
			batadv_neigh_node_put(neigh_node);
		} else {
			/* only necessary if not the whole neighbor is to be
			 * deleted, but some interface has been removed.
			 */
			batadv_purge_neigh_ifinfo(bat_priv, neigh_node);
		}
	}

	spin_unlock_bh(&orig_node->neigh_list_lock);
	return neigh_purged;
}

/**
 * batadv_find_best_neighbor() - finds the best neighbor after purging
 * @bat_priv: the bat priv with all the mesh interface information
 * @orig_node: orig node which is to be checked
 * @if_outgoing: the interface for which the metric should be compared
 *
 * Return: the current best neighbor, with refcount increased.
 */
static struct batadv_neigh_node *
batadv_find_best_neighbor(struct batadv_priv *bat_priv,
			  struct batadv_orig_node *orig_node,
			  struct batadv_hard_iface *if_outgoing)
{
	struct batadv_neigh_node *best = NULL, *neigh;
	struct batadv_algo_ops *bao = bat_priv->algo_ops;

	rcu_read_lock();
	hlist_for_each_entry_rcu(neigh, &orig_node->neigh_list, list) {
		if (best && (bao->neigh.cmp(neigh, if_outgoing, best,
					    if_outgoing) <= 0))
			continue;

		if (!kref_get_unless_zero(&neigh->refcount))
			continue;

		batadv_neigh_node_put(best);

		best = neigh;
	}
	rcu_read_unlock();

	return best;
}

/**
 * batadv_purge_orig_node() - purges obsolete information from an orig_node
 * @bat_priv: the bat priv with all the mesh interface information
 * @orig_node: orig node which is to be checked
 *
 * This function checks if the orig_node or substructures of it have become
 * obsolete, and purges this information if that's the case.
 *
 * Return: true if the orig_node is to be removed, false otherwise.
 */
static bool batadv_purge_orig_node(struct batadv_priv *bat_priv,
				   struct batadv_orig_node *orig_node)
{
	struct batadv_neigh_node *best_neigh_node;
	struct batadv_hard_iface *hard_iface;
	bool changed_ifinfo, changed_neigh;
	struct list_head *iter;

	if (batadv_has_timed_out(orig_node->last_seen,
				 2 * BATADV_PURGE_TIMEOUT)) {
		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
			   "Originator timeout: originator %pM, last_seen %u\n",
			   orig_node->orig,
			   jiffies_to_msecs(orig_node->last_seen));
		return true;
	}
	changed_ifinfo = batadv_purge_orig_ifinfo(bat_priv, orig_node);
	changed_neigh = batadv_purge_orig_neighbors(bat_priv, orig_node);

	if (!changed_ifinfo && !changed_neigh)
		return false;

	/* first for NULL ... */
	best_neigh_node = batadv_find_best_neighbor(bat_priv, orig_node,
						    BATADV_IF_DEFAULT);
	batadv_update_route(bat_priv, orig_node, BATADV_IF_DEFAULT,
			    best_neigh_node);
	batadv_neigh_node_put(best_neigh_node);

	/* ... then for all other interfaces. */
	rcu_read_lock();
	netdev_for_each_lower_private_rcu(bat_priv->mesh_iface, hard_iface, iter) {
		if (hard_iface->if_status != BATADV_IF_ACTIVE)
			continue;

		if (!kref_get_unless_zero(&hard_iface->refcount))
			continue;

		best_neigh_node = batadv_find_best_neighbor(bat_priv,
							    orig_node,
							    hard_iface);
		batadv_update_route(bat_priv, orig_node, hard_iface,
				    best_neigh_node);
		batadv_neigh_node_put(best_neigh_node);

		batadv_hardif_put(hard_iface);
	}
	rcu_read_unlock();

	return false;
}

/**
 * batadv_purge_orig_ref() - Purge all outdated originators
 * @bat_priv: the bat priv with all the mesh interface information
 */
void batadv_purge_orig_ref(struct batadv_priv *bat_priv)
{
	struct batadv_hashtable *hash = bat_priv->orig_hash;
	struct hlist_node *node_tmp;
	struct hlist_head *head;
	spinlock_t *list_lock; /* spinlock to protect write access */
	struct batadv_orig_node *orig_node;
	u32 i;

	if (!hash)
		return;

	/* for all origins... */
	for (i = 0; i < hash->size; i++) {
		head = &hash->table[i];
		if (hlist_empty(head))
			continue;
		list_lock = &hash->list_locks[i];

		spin_lock_bh(list_lock);
		hlist_for_each_entry_safe(orig_node, node_tmp,
					  head, hash_entry) {
			if (batadv_purge_orig_node(bat_priv, orig_node)) {
				batadv_gw_node_delete(bat_priv, orig_node);
				hlist_del_rcu(&orig_node->hash_entry);
				batadv_tt_global_del_orig(orig_node->bat_priv,
							  orig_node, -1,
							  "originator timed out");
				batadv_orig_node_put(orig_node);
				continue;
			}

			batadv_frag_purge_orig(orig_node,
					       batadv_frag_check_entry);
		}
		spin_unlock_bh(list_lock);
	}

	batadv_gw_election(bat_priv);
}

static void batadv_purge_orig(struct work_struct *work)
{
	struct delayed_work *delayed_work;
	struct batadv_priv *bat_priv;

	delayed_work = to_delayed_work(work);
	bat_priv = container_of(delayed_work, struct batadv_priv, orig_work);
	batadv_purge_orig_ref(bat_priv);
	queue_delayed_work(batadv_event_workqueue,
			   &bat_priv->orig_work,
			   msecs_to_jiffies(BATADV_ORIG_WORK_PERIOD));
}

/**
 * batadv_orig_dump() - Dump to netlink the originator infos for a specific
 *  outgoing interface
 * @msg: message to dump into
 * @cb: parameters for the dump
 *
 * Return: 0 or error value
 */
int batadv_orig_dump(struct sk_buff *msg, struct netlink_callback *cb)
{
	struct batadv_hard_iface *primary_if, *hard_iface;
	struct net_device *mesh_iface;
	struct batadv_priv *bat_priv;
	int ret;

	mesh_iface = batadv_netlink_get_meshif(cb);
	if (IS_ERR(mesh_iface))
		return PTR_ERR(mesh_iface);

	bat_priv = netdev_priv(mesh_iface);

	primary_if = batadv_primary_if_get_selected(bat_priv);
	if (!primary_if) {
		ret = -ENOENT;
		goto out_put_mesh_iface;
	}

	if (primary_if->if_status != BATADV_IF_ACTIVE) {
		ret = -ENOENT;
		goto out_put_primary_if;
	}

	hard_iface = batadv_netlink_get_hardif(bat_priv, cb);
	if (IS_ERR(hard_iface) && PTR_ERR(hard_iface) != -ENONET) {
		ret = PTR_ERR(hard_iface);
		goto out_put_primary_if;
	} else if (IS_ERR(hard_iface)) {
		/* => PTR_ERR(hard_iface) == -ENONET
		 * => no hard-iface given, ok
		 */
		hard_iface = BATADV_IF_DEFAULT;
	}

	if (!bat_priv->algo_ops->orig.dump) {
		ret = -EOPNOTSUPP;
		goto out_put_hard_iface;
	}

	bat_priv->algo_ops->orig.dump(msg, cb, bat_priv, hard_iface);

	ret = msg->len;

out_put_hard_iface:
	batadv_hardif_put(hard_iface);
out_put_primary_if:
	batadv_hardif_put(primary_if);
out_put_mesh_iface:
	dev_put(mesh_iface);

	return ret;
}