batman-adv: Multicast Listener Announcements via Translation Table

	  If you think that your network does not need this feature you

	  can safely disable it and save some space.

config BATMAN_ADV_MCAST

	bool "Multicast optimisation"

	depends on BATMAN_ADV

	default n

	help

	  This option enables the multicast optimisation which aims to

	  reduce the air overhead while improving the reliability of

	  multicast messages.

config BATMAN_ADV_DEBUG

	bool "B.A.T.M.A.N. debugging"

	depends on BATMAN_ADV

batman-adv-y += soft-interface.o

batman-adv-y += sysfs.o

batman-adv-y += translation-table.o

batman-adv-$(CONFIG_BATMAN_ADV_MCAST) += multicast.o

#include "gateway_client.h"

#include "bridge_loop_avoidance.h"

#include "distributed-arp-table.h"

#include "multicast.h"

#include "gateway_common.h"

#include "hash.h"

#include "bat_algo.h"

	INIT_LIST_HEAD(&bat_priv->tt.changes_list);

	INIT_LIST_HEAD(&bat_priv->tt.req_list);

	INIT_LIST_HEAD(&bat_priv->tt.roam_list);

#ifdef CONFIG_BATMAN_ADV_MCAST

	INIT_HLIST_HEAD(&bat_priv->mcast.mla_list);

#endif

	INIT_HLIST_HEAD(&bat_priv->tvlv.container_list);

	INIT_HLIST_HEAD(&bat_priv->tvlv.handler_list);

	INIT_HLIST_HEAD(&bat_priv->softif_vlan_list);

	batadv_dat_free(bat_priv);

	batadv_bla_free(bat_priv);

	batadv_mcast_free(bat_priv);

	/* Free the TT and the originator tables only after having terminated

	 * all the other depending components which may use these structures for

	 * their purposes.

#include <linux/percpu.h>

#include <linux/slab.h>

#include <net/sock.h>		/* struct sock */

#include <net/addrconf.h>	/* ipv6 address stuff */

#include <net/rtnetlink.h>

#include <linux/jiffies.h>

#include <linux/seq_file.h>

/* Copyright (C) 2014 B.A.T.M.A.N. contributors:

 *

 * Linus Lüssing

 *

 * 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 "main.h"

#include "multicast.h"

#include "originator.h"

#include "hard-interface.h"

#include "translation-table.h"

/**

 * batadv_mcast_mla_softif_get - get softif multicast listeners

 * @dev: the device to collect multicast addresses from

 * @mcast_list: a list to put found addresses into

 *

 * Collect multicast addresses of the local multicast listeners

 * on the given soft interface, dev, in the given mcast_list.

 *

 * Returns -ENOMEM on memory allocation error or the number of

 * items added to the mcast_list otherwise.

 */

static int batadv_mcast_mla_softif_get(struct net_device *dev,

				       struct hlist_head *mcast_list)

{

	struct netdev_hw_addr *mc_list_entry;

	struct batadv_hw_addr *new;

	int ret = 0;

	netif_addr_lock_bh(dev);

	netdev_for_each_mc_addr(mc_list_entry, dev) {

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

		if (!new) {

			ret = -ENOMEM;

			break;

		}

		ether_addr_copy(new->addr, mc_list_entry->addr);

		hlist_add_head(&new->list, mcast_list);

		ret++;

	}

	netif_addr_unlock_bh(dev);

	return ret;

}

/**

 * batadv_mcast_mla_is_duplicate - check whether an address is in a list

 * @mcast_addr: the multicast address to check

 * @mcast_list: the list with multicast addresses to search in

 *

 * Returns true if the given address is already in the given list.

 * Otherwise returns false.

 */

static bool batadv_mcast_mla_is_duplicate(uint8_t *mcast_addr,

					  struct hlist_head *mcast_list)

{

	struct batadv_hw_addr *mcast_entry;

	hlist_for_each_entry(mcast_entry, mcast_list, list)

		if (batadv_compare_eth(mcast_entry->addr, mcast_addr))

			return true;

	return false;

}

/**

 * batadv_mcast_mla_list_free - free a list of multicast addresses

 * @mcast_list: the list to free

 *

 * Removes and frees all items in the given mcast_list.

 */

static void batadv_mcast_mla_list_free(struct hlist_head *mcast_list)

{

	struct batadv_hw_addr *mcast_entry;

	struct hlist_node *tmp;

	hlist_for_each_entry_safe(mcast_entry, tmp, mcast_list, list) {

		hlist_del(&mcast_entry->list);

		kfree(mcast_entry);

	}

}

/**

 * batadv_mcast_mla_tt_retract - clean up multicast listener announcements

 * @bat_priv: the bat priv with all the soft interface information

 * @mcast_list: a list of addresses which should _not_ be removed

 *

 * Retracts the announcement of any multicast listener from the

 * translation table except the ones listed in the given mcast_list.

 *

 * If mcast_list is NULL then all are retracted.

 */

static void batadv_mcast_mla_tt_retract(struct batadv_priv *bat_priv,

					struct hlist_head *mcast_list)

{

	struct batadv_hw_addr *mcast_entry;

	struct hlist_node *tmp;

	hlist_for_each_entry_safe(mcast_entry, tmp, &bat_priv->mcast.mla_list,

				  list) {

		if (mcast_list &&

		    batadv_mcast_mla_is_duplicate(mcast_entry->addr,

						  mcast_list))

			continue;

		batadv_tt_local_remove(bat_priv, mcast_entry->addr,

				       BATADV_NO_FLAGS,

				       "mcast TT outdated", false);

		hlist_del(&mcast_entry->list);

		kfree(mcast_entry);

	}

}

/**

 * batadv_mcast_mla_tt_add - add multicast listener announcements

 * @bat_priv: the bat priv with all the soft interface information

 * @mcast_list: a list of addresses which are going to get added

 *

 * Adds multicast listener announcements from the given mcast_list to the

 * translation table if they have not been added yet.

 */

static void batadv_mcast_mla_tt_add(struct batadv_priv *bat_priv,

				    struct hlist_head *mcast_list)

{

	struct batadv_hw_addr *mcast_entry;

	struct hlist_node *tmp;

	if (!mcast_list)

		return;

	hlist_for_each_entry_safe(mcast_entry, tmp, mcast_list, list) {

		if (batadv_mcast_mla_is_duplicate(mcast_entry->addr,

						  &bat_priv->mcast.mla_list))

			continue;

		if (!batadv_tt_local_add(bat_priv->soft_iface,

					 mcast_entry->addr, BATADV_NO_FLAGS,

					 BATADV_NULL_IFINDEX, BATADV_NO_MARK))

			continue;

		hlist_del(&mcast_entry->list);

		hlist_add_head(&mcast_entry->list, &bat_priv->mcast.mla_list);

	}

}

/**

 * batadv_mcast_has_bridge - check whether the soft-iface is bridged

 * @bat_priv: the bat priv with all the soft interface information

 *

 * Checks whether there is a bridge on top of our soft interface. Returns

 * true if so, false otherwise.

 */

static bool batadv_mcast_has_bridge(struct batadv_priv *bat_priv)

{

	struct net_device *upper = bat_priv->soft_iface;

	rcu_read_lock();

	do {

		upper = netdev_master_upper_dev_get_rcu(upper);

	} while (upper && !(upper->priv_flags & IFF_EBRIDGE));

	rcu_read_unlock();

	return upper;

}

/**

 * batadv_mcast_mla_update - update the own MLAs

 * @bat_priv: the bat priv with all the soft interface information

 *

 * Update the own multicast listener announcements in the translation

 * table.

 */

void batadv_mcast_mla_update(struct batadv_priv *bat_priv)

{

	struct net_device *soft_iface = bat_priv->soft_iface;

	struct hlist_head mcast_list = HLIST_HEAD_INIT;

	int ret;

	/* Avoid attaching MLAs, if there is a bridge on top of our soft

	 * interface, we don't support that yet (TODO)

	 */

	if (batadv_mcast_has_bridge(bat_priv))

		goto update;

	ret = batadv_mcast_mla_softif_get(soft_iface, &mcast_list);

	if (ret < 0)

		goto out;

update:

	batadv_mcast_mla_tt_retract(bat_priv, &mcast_list);

	batadv_mcast_mla_tt_add(bat_priv, &mcast_list);

out:

	batadv_mcast_mla_list_free(&mcast_list);

}

/**

 * batadv_mcast_free - free the multicast optimizations structures

 * @bat_priv: the bat priv with all the soft interface information

 */

void batadv_mcast_free(struct batadv_priv *bat_priv)

{

	batadv_mcast_mla_tt_retract(bat_priv, NULL);

}