path: root/net/batman-adv/originator.c

// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2009-2019  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, see <http://www.gnu.org/licenses/>.
 */

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

#include <linux/atomic.h>
#include <linux/errno.h>
#include <linux/etherdevice.h>
#include <linux/gfp.h>
#include <linux/jiffies.h>
#include <linux/kernel.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/seq_file.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/stddef.h>
#include <linux/workqueue.h>
#include <net/sock.h>
#include <uapi/linux/batman_adv.h>

#include "bat_algo.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 "network-coding.h"
#include "routing.h"
#include "soft-interface.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 soft 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_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;

	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
 */
static 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_orig_node_vlan_put() - decrement the refcounter and possibly release
 *  the originator-vlan object
 * @orig_vlan: the originator-vlan object to release
 */
void batadv_orig_node_vlan_put(struct batadv_orig_node_vlan *orig_vlan)
{
	kref_put(&orig_vlan->refcount, batadv_orig_node_vlan_release);
}

/**
 * batadv_originator_init() - Initialize all originator structures
 * @bat_priv: the bat priv with all the soft 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
 */
static void batadv_neigh_ifinfo_release(struct kref *ref)