/* 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);
}
