Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1616 insertions, 0 deletions

diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c
new file mode 100644
index 000000000..9b3311dae
--- /dev/null
+++ b/net/batman-adv/multicast.c
@@ -0,0 +1,1616 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2014-2018  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 "multicast.h"
+#include "main.h"
+
+#include <linux/atomic.h>
+#include <linux/bitops.h>
+#include <linux/bug.h>
+#include <linux/byteorder/generic.h>
+#include <linux/errno.h>
+#include <linux/etherdevice.h>
+#include <linux/gfp.h>
+#include <linux/icmpv6.h>
+#include <linux/if_bridge.h>
+#include <linux/if_ether.h>
+#include <linux/igmp.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/ip.h>
+#include <linux/ipv6.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/printk.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/string.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+#include <net/addrconf.h>
+#include <net/genetlink.h>
+#include <net/if_inet6.h>
+#include <net/ip.h>
+#include <net/ipv6.h>
+#include <net/netlink.h>
+#include <net/sock.h>
+#include <uapi/linux/batadv_packet.h>
+#include <uapi/linux/batman_adv.h>
+
+#include "bridge_loop_avoidance.h"
+#include "hard-interface.h"
+#include "hash.h"
+#include "log.h"
+#include "netlink.h"
+#include "send.h"
+#include "soft-interface.h"
+#include "translation-table.h"
+#include "tvlv.h"
+
+static void batadv_mcast_mla_update(struct work_struct *work);
+
+/**
+ * batadv_mcast_start_timer() - schedule the multicast periodic worker
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+static void batadv_mcast_start_timer(struct batadv_priv *bat_priv)
+{
+	queue_delayed_work(batadv_event_workqueue, &bat_priv->mcast.work,
+			   msecs_to_jiffies(BATADV_MCAST_WORK_PERIOD));
+}
+
+/**
+ * batadv_mcast_get_bridge() - get the bridge on top of the softif if it exists
+ * @soft_iface: netdev struct of the mesh interface
+ *
+ * If the given soft interface has a bridge on top then the refcount
+ * of the according net device is increased.
+ *
+ * Return: NULL if no such bridge exists. Otherwise the net device of the
+ * bridge.
+ */
+static struct net_device *batadv_mcast_get_bridge(struct net_device *soft_iface)
+{
+	struct net_device *upper = soft_iface;
+
+	rcu_read_lock();
+	do {
+		upper = netdev_master_upper_dev_get_rcu(upper);
+	} while (upper && !(upper->priv_flags & IFF_EBRIDGE));
+
+	if (upper)
+		dev_hold(upper);
+	rcu_read_unlock();
+
+	return upper;
+}
+
+/**
+ * batadv_mcast_addr_is_ipv4() - check if multicast MAC is IPv4
+ * @addr: the MAC address to check
+ *
+ * Return: True, if MAC address is one reserved for IPv4 multicast, false
+ * otherwise.
+ */
+static bool batadv_mcast_addr_is_ipv4(const u8 *addr)
+{
+	static const u8 prefix[] = {0x01, 0x00, 0x5E};
+
+	return memcmp(prefix, addr, sizeof(prefix)) == 0;
+}
+
+/**
+ * batadv_mcast_addr_is_ipv6() - check if multicast MAC is IPv6
+ * @addr: the MAC address to check
+ *
+ * Return: True, if MAC address is one reserved for IPv6 multicast, false
+ * otherwise.
+ */
+static bool batadv_mcast_addr_is_ipv6(const u8 *addr)
+{
+	static const u8 prefix[] = {0x33, 0x33};
+
+	return memcmp(prefix, addr, sizeof(prefix)) == 0;
+}
+
+/**
+ * batadv_mcast_mla_softif_get() - get softif multicast listeners
+ * @bat_priv: the bat priv with all the soft interface information
+ * @dev: the device to collect multicast addresses from
+ * @mcast_list: a list to put found addresses into
+ *
+ * Collects multicast addresses of multicast listeners residing
+ * on this kernel on the given soft interface, dev, in
+ * the given mcast_list. In general, multicast listeners provided by
+ * your multicast receiving applications run directly on this node.
+ *
+ * If there is a bridge interface on top of dev, collects from that one
+ * instead. Just like with IP addresses and routes, multicast listeners
+ * will(/should) register to the bridge interface instead of an
+ * enslaved bat0.
+ *
+ * Return: -ENOMEM on memory allocation error or the number of
+ * items added to the mcast_list otherwise.
+ */
+static int batadv_mcast_mla_softif_get(struct batadv_priv *bat_priv,
+				       struct net_device *dev,
+				       struct hlist_head *mcast_list)
+{
+	bool all_ipv4 = bat_priv->mcast.flags & BATADV_MCAST_WANT_ALL_IPV4;
+	bool all_ipv6 = bat_priv->mcast.flags & BATADV_MCAST_WANT_ALL_IPV6;
+	struct net_device *bridge = batadv_mcast_get_bridge(dev);
+	struct netdev_hw_addr *mc_list_entry;
+	struct batadv_hw_addr *new;
+	int ret = 0;
+
+	netif_addr_lock_bh(bridge ? bridge : dev);
+	netdev_for_each_mc_addr(mc_list_entry, bridge ? bridge : dev) {
+		if (all_ipv4 && batadv_mcast_addr_is_ipv4(mc_list_entry->addr))
+			continue;
+
+		if (all_ipv6 && batadv_mcast_addr_is_ipv6(mc_list_entry->addr))
+			continue;
+
+		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(bridge ? bridge : dev);
+
+	if (bridge)
+		dev_put(bridge);
+
+	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
+ *
+ * Return: true if the given address is already in the given list.
+ * Otherwise returns false.
+ */
+static bool batadv_mcast_mla_is_duplicate(u8 *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_br_addr_cpy() - copy a bridge multicast address
+ * @dst: destination to write to - a multicast MAC address
+ * @src: source to read from - a multicast IP address
+ *
+ * Converts a given multicast IPv4/IPv6 address from a bridge
+ * to its matching multicast MAC address and copies it into the given
+ * destination buffer.
+ *
+ * Caller needs to make sure the destination buffer can hold
+ * at least ETH_ALEN bytes.
+ */
+static void batadv_mcast_mla_br_addr_cpy(char *dst, const struct br_ip *src)
+{
+	if (src->proto == htons(ETH_P_IP))
+		ip_eth_mc_map(src->u.ip4, dst);
+#if IS_ENABLED(CONFIG_IPV6)
+	else if (src->proto == htons(ETH_P_IPV6))
+		ipv6_eth_mc_map(&src->u.ip6, dst);
+#endif
+	else
+		eth_zero_addr(dst);
+}
+
+/**
+ * batadv_mcast_mla_bridge_get() - get bridged-in multicast listeners
+ * @bat_priv: the bat priv with all the soft interface information
+ * @dev: a bridge slave whose bridge to collect multicast addresses from
+ * @mcast_list: a list to put found addresses into
+ *
+ * Collects multicast addresses of multicast listeners residing
+ * on foreign, non-mesh devices which we gave access to our mesh via
+ * a bridge on top of the given soft interface, dev, in the given
+ * mcast_list.
+ *
+ * Return: -ENOMEM on memory allocation error or the number of
+ * items added to the mcast_list otherwise.
+ */
+static int batadv_mcast_mla_bridge_get(struct batadv_priv *bat_priv,
+				       struct net_device *dev,
+				       struct hlist_head *mcast_list)
+{
+	struct list_head bridge_mcast_list = LIST_HEAD_INIT(bridge_mcast_list);
+	bool all_ipv4 = bat_priv->mcast.flags & BATADV_MCAST_WANT_ALL_IPV4;
+	bool all_ipv6 = bat_priv->mcast.flags & BATADV_MCAST_WANT_ALL_IPV6;
+	struct br_ip_list *br_ip_entry, *tmp;
+	struct batadv_hw_addr *new;
+	u8 mcast_addr[ETH_ALEN];
+	int ret;
+
+	/* we don't need to detect these devices/listeners, the IGMP/MLD
+	 * snooping code of the Linux bridge already does that for us
+	 */
+	ret = br_multicast_list_adjacent(dev, &bridge_mcast_list);
+	if (ret < 0)
+		goto out;
+
+	list_for_each_entry(br_ip_entry, &bridge_mcast_list, list) {
+		if (all_ipv4 && br_ip_entry->addr.proto == htons(ETH_P_IP))
+			continue;
+
+		if (all_ipv6 && br_ip_entry->addr.proto == htons(ETH_P_IPV6))
+			continue;
+
+		batadv_mcast_mla_br_addr_cpy(mcast_addr, &br_ip_entry->addr);
+		if (batadv_mcast_mla_is_duplicate(mcast_addr, mcast_list))
+			continue;
+
+		new = kmalloc(sizeof(*new), GFP_ATOMIC);
+		if (!new) {
+			ret = -ENOMEM;
+			break;
+		}
+
+		ether_addr_copy(new->addr, mcast_addr);
+		hlist_add_head(&new->list, mcast_list);
+	}
+
+out:
+	list_for_each_entry_safe(br_ip_entry, tmp, &bridge_mcast_list, list) {
+		list_del(&br_ip_entry->list);
+		kfree(br_ip_entry);
+	}
+
+	return ret;
+}
+
+/**
+ * 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.
+ *
+ * Return: true if there is a bridge, 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_querier_log() - debug output regarding the querier status on
+ *  link
+ * @bat_priv: the bat priv with all the soft interface information
+ * @str_proto: a string for the querier protocol (e.g. "IGMP" or "MLD")
+ * @old_state: the previous querier state on our link
+ * @new_state: the new querier state on our link
+ *
+ * Outputs debug messages to the logging facility with log level 'mcast'
+ * regarding changes to the querier status on the link which are relevant
+ * to our multicast optimizations.
+ *
+ * Usually this is about whether a querier appeared or vanished in
+ * our mesh or whether the querier is in the suboptimal position of being
+ * behind our local bridge segment: Snooping switches will directly
+ * forward listener reports to the querier, therefore batman-adv and
+ * the bridge will potentially not see these listeners - the querier is
+ * potentially shadowing listeners from us then.
+ *
+ * This is only interesting for nodes with a bridge on top of their
+ * soft interface.
+ */
+static void
+batadv_mcast_querier_log(struct batadv_priv *bat_priv, char *str_proto,
+			 struct batadv_mcast_querier_state *old_state,
+			 struct batadv_mcast_querier_state *new_state)
+{
+	if (!old_state->exists && new_state->exists)
+		batadv_info(bat_priv->soft_iface, "%s Querier appeared\n",
+			    str_proto);
+	else if (old_state->exists && !new_state->exists)
+		batadv_info(bat_priv->soft_iface,
+			    "%s Querier disappeared - multicast optimizations disabled\n",
+			    str_proto);
+	else if (!bat_priv->mcast.bridged && !new_state->exists)
+		batadv_info(bat_priv->soft_iface,
+			    "No %s Querier present - multicast optimizations disabled\n",
+			    str_proto);
+
+	if (new_state->exists) {
+		if ((!old_state->shadowing && new_state->shadowing) ||
+		    (!old_state->exists && new_state->shadowing))
+			batadv_dbg(BATADV_DBG_MCAST, bat_priv,
+				   "%s Querier is behind our bridged segment: Might shadow listeners\n",
+				   str_proto);
+		else if (old_state->shadowing && !new_state->shadowing)
+			batadv_dbg(BATADV_DBG_MCAST, bat_priv,
+				   "%s Querier is not behind our bridged segment\n",
+				   str_proto);
+	}
+}
+
+/**
+ * batadv_mcast_bridge_log() - debug output for topology changes in bridged
+ *  setups
+ * @bat_priv: the bat priv with all the soft interface information
+ * @bridged: a flag about whether the soft interface is currently bridged or not
+ * @querier_ipv4: (maybe) new status of a potential, selected IGMP querier
+ * @querier_ipv6: (maybe) new status of a potential, selected MLD querier
+ *
+ * If no bridges are ever used on this node, then this function does nothing.
+ *
+ * Otherwise this function outputs debug information to the 'mcast' log level
+ * which might be relevant to our multicast optimizations.
+ *
+ * More precisely, it outputs information when a bridge interface is added or
+ * removed from a soft interface. And when a bridge is present, it further
+ * outputs information about the querier state which is relevant for the
+ * multicast flags this node is going to set.
+ */
+static void
+batadv_mcast_bridge_log(struct batadv_priv *bat_priv, bool bridged,
+			struct batadv_mcast_querier_state *querier_ipv4,
+			struct batadv_mcast_querier_state *querier_ipv6)
+{
+	if (!bat_priv->mcast.bridged && bridged)
+		batadv_dbg(BATADV_DBG_MCAST, bat_priv,
+			   "Bridge added: Setting Unsnoopables(U)-flag\n");
+	else if (bat_priv->mcast.bridged && !bridged)
+		batadv_dbg(BATADV_DBG_MCAST, bat_priv,
+			   "Bridge removed: Unsetting Unsnoopables(U)-flag\n");
+
+	if (bridged) {
+		batadv_mcast_querier_log(bat_priv, "IGMP",
+					 &bat_priv->mcast.querier_ipv4,
+					 querier_ipv4);
+		batadv_mcast_querier_log(bat_priv, "MLD",
+					 &bat_priv->mcast.querier_ipv6,
+					 querier_ipv6);
+	}
+}
+
+/**
+ * batadv_mcast_flags_logs() - output debug information about mcast flag changes
+ * @bat_priv: the bat priv with all the soft interface information
+ * @flags: flags indicating the new multicast state
+ *
+ * Whenever the multicast flags this nodes announces changes (@mcast_flags vs.
+ * bat_priv->mcast.flags), this notifies userspace via the 'mcast' log level.
+ */
+static void batadv_mcast_flags_log(struct batadv_priv *bat_priv, u8 flags)
+{
+	u8 old_flags = bat_priv->mcast.flags;
+	char str_old_flags[] = "[...]";
+
+	sprintf(str_old_flags, "[%c%c%c]",
+		(old_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) ? 'U' : '.',
+		(old_flags & BATADV_MCAST_WANT_ALL_IPV4) ? '4' : '.',
+		(old_flags & BATADV_MCAST_WANT_ALL_IPV6) ? '6' : '.');
+
+	batadv_dbg(BATADV_DBG_MCAST, bat_priv,
+		   "Changing multicast flags from '%s' to '[%c%c%c]'\n",
+		   bat_priv->mcast.enabled ? str_old_flags : "<undefined>",
+		   (flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) ? 'U' : '.',
+		   (flags & BATADV_MCAST_WANT_ALL_IPV4) ? '4' : '.',
+		   (flags & BATADV_MCAST_WANT_ALL_IPV6) ? '6' : '.');
+}
+
+/**
+ * batadv_mcast_mla_tvlv_update() - update multicast tvlv
+ * @bat_priv: the bat priv with all the soft interface information
+ *
+ * Updates the own multicast tvlv with our current multicast related settings,
+ * capabilities and inabilities.
+ *
+ * Return: false if we want all IPv4 && IPv6 multicast traffic and true
+ * otherwise.
+ */
+static bool batadv_mcast_mla_tvlv_update(struct batadv_priv *bat_priv)
+{
+	struct batadv_tvlv_mcast_data mcast_data;
+	struct batadv_mcast_querier_state querier4 = {false, false};
+	struct batadv_mcast_querier_state querier6 = {false, false};
+	struct net_device *dev = bat_priv->soft_iface;
+	bool bridged;
+
+	mcast_data.flags = BATADV_NO_FLAGS;
+	memset(mcast_data.reserved, 0, sizeof(mcast_data.reserved));
+
+	bridged = batadv_mcast_has_bridge(bat_priv);
+	if (!bridged)
+		goto update;
+
+	if (!IS_ENABLED(CONFIG_BRIDGE_IGMP_SNOOPING))
+		pr_warn_once("No bridge IGMP snooping compiled - multicast optimizations disabled\n");
+
+	querier4.exists = br_multicast_has_querier_anywhere(dev, ETH_P_IP);
+	querier4.shadowing = br_multicast_has_querier_adjacent(dev, ETH_P_IP);
+
+	querier6.exists = br_multicast_has_querier_anywhere(dev, ETH_P_IPV6);
+	querier6.shadowing = br_multicast_has_querier_adjacent(dev, ETH_P_IPV6);
+
+	mcast_data.flags |= BATADV_MCAST_WANT_ALL_UNSNOOPABLES;
+
+	/* 1) If no querier exists at all, then multicast listeners on
+	 *    our local TT clients behind the bridge will keep silent.
+	 * 2) If the selected querier is on one of our local TT clients,
+	 *    behind the bridge, then this querier might shadow multicast
+	 *    listeners on our local TT clients, behind this bridge.
+	 *
+	 * In both cases, we will signalize other batman nodes that
+	 * we need all multicast traffic of the according protocol.
+	 */
+	if (!querier4.exists || querier4.shadowing)
+		mcast_data.flags |= BATADV_MCAST_WANT_ALL_IPV4;
+
+	if (!querier6.exists || querier6.shadowing)
+		mcast_data.flags |= BATADV_MCAST_WANT_ALL_IPV6;
+
+update:
+	batadv_mcast_bridge_log(bat_priv, bridged, &querier4, &querier6);
+
+	bat_priv->mcast.querier_ipv4.exists = querier4.exists;
+	bat_priv->mcast.querier_ipv4.shadowing = querier4.shadowing;
+
+	bat_priv->mcast.querier_ipv6.exists = querier6.exists;
+	bat_priv->mcast.querier_ipv6.shadowing = querier6.shadowing;
+
+	bat_priv->mcast.bridged = bridged;
+
+	if (!bat_priv->mcast.enabled ||
+	    mcast_data.flags != bat_priv->mcast.flags) {
+		batadv_mcast_flags_log(bat_priv, mcast_data.flags);
+		batadv_tvlv_container_register(bat_priv, BATADV_TVLV_MCAST, 2,
+					       &mcast_data, sizeof(mcast_data));
+		bat_priv->mcast.flags = mcast_data.flags;
+		bat_priv->mcast.enabled = true;
+	}
+
+	return !(mcast_data.flags & BATADV_MCAST_WANT_ALL_IPV4 &&
+		 mcast_data.flags & BATADV_MCAST_WANT_ALL_IPV6);
+}
+
+/**
+ * __batadv_mcast_mla_update() - update the own MLAs
+ * @bat_priv: the bat priv with all the soft interface information
+ *
+ * Updates the own multicast listener announcements in the translation
+ * table as well as the own, announced multicast tvlv container.
+ *
+ * Note that non-conflicting reads and writes to bat_priv->mcast.mla_list
+ * in batadv_mcast_mla_tt_retract() and batadv_mcast_mla_tt_add() are
+ * ensured by the non-parallel execution of the worker this function
+ * belongs to.
+ */
+static 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;
+
+	if (!batadv_mcast_mla_tvlv_update(bat_priv))
+		goto update;
+
+	ret = batadv_mcast_mla_softif_get(bat_priv, soft_iface, &mcast_list);
+	if (ret < 0)
+		goto out;
+
+	ret = batadv_mcast_mla_bridge_get(bat_priv, 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_mla_update() - update the own MLAs
+ * @work: kernel work struct
+ *
+ * Updates the own multicast listener announcements in the translation
+ * table as well as the own, announced multicast tvlv container.
+ *
+ * In the end, reschedules the work timer.
+ */
+static void batadv_mcast_mla_update(struct work_struct *work)
+{
+	struct delayed_work *delayed_work;
+	struct batadv_priv_mcast *priv_mcast;
+	struct batadv_priv *bat_priv;
+
+	delayed_work = to_delayed_work(work);
+	priv_mcast = container_of(delayed_work, struct batadv_priv_mcast, work);
+	bat_priv = container_of(priv_mcast, struct batadv_priv, mcast);
+
+	spin_lock(&bat_priv->mcast.mla_lock);
+	__batadv_mcast_mla_update(bat_priv);
+	spin_unlock(&bat_priv->mcast.mla_lock);
+
+	batadv_mcast_start_timer(bat_priv);
+}
+
+/**
+ * batadv_mcast_is_report_ipv4() - check for IGMP reports
+ * @skb: the ethernet frame destined for the mesh
+ *
+ * This call might reallocate skb data.
+ *
+ * Checks whether the given frame is a valid IGMP report.
+ *
+ * Return: If so then true, otherwise false.
+ */
+static bool batadv_mcast_is_report_ipv4(struct sk_buff *skb)
+{
+	if (ip_mc_check_igmp(skb, NULL) < 0)
+		return false;
+
+	switch (igmp_hdr(skb)->type) {
+	case IGMP_HOST_MEMBERSHIP_REPORT:
+	case IGMPV2_HOST_MEMBERSHIP_REPORT:
+	case IGMPV3_HOST_MEMBERSHIP_REPORT:
+		return true;
+	}
+
+	return false;
+}
+
+/**
+ * batadv_mcast_forw_mode_check_ipv4() - check for optimized forwarding
+ *  potential
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: the IPv4 packet to check
+ * @is_unsnoopable: stores whether the destination is snoopable
+ *
+ * Checks whether the given IPv4 packet has the potential to be forwarded with a
+ * mode more optimal than classic flooding.
+ *
+ * Return: If so then 0. Otherwise -EINVAL or -ENOMEM in case of memory
+ * allocation failure.
+ */
+static int batadv_mcast_forw_mode_check_ipv4(struct batadv_priv *bat_priv,
+					     struct sk_buff *skb,
+					     bool *is_unsnoopable)
+{
+	struct iphdr *iphdr;
+
+	/* We might fail due to out-of-memory -> drop it */
+	if (!pskb_may_pull(skb, sizeof(struct ethhdr) + sizeof(*iphdr)))
+		return -ENOMEM;
+
+	if (batadv_mcast_is_report_ipv4(skb))
+		return -EINVAL;
+
+	iphdr = ip_hdr(skb);
+
+	/* TODO: Implement Multicast Router Discovery (RFC4286),
+	 * then allow scope > link local, too
+	 */
+	if (!ipv4_is_local_multicast(iphdr->daddr))
+		return -EINVAL;
+
+	/* link-local multicast listeners behind a bridge are
+	 * not snoopable (see RFC4541, section 2.1.2.2)
+	 */
+	*is_unsnoopable = true;
+
+	return 0;
+}
+
+/**
+ * batadv_mcast_is_report_ipv6() - check for MLD reports
+ * @skb: the ethernet frame destined for the mesh
+ *
+ * This call might reallocate skb data.
+ *
+ * Checks whether the given frame is a valid MLD report.
+ *
+ * Return: If so then true, otherwise false.
+ */
+static bool batadv_mcast_is_report_ipv6(struct sk_buff *skb)
+{
+	if (ipv6_mc_check_mld(skb, NULL) < 0)
+		return false;
+
+	switch (icmp6_hdr(skb)->icmp6_type) {
+	case ICMPV6_MGM_REPORT:
+	case ICMPV6_MLD2_REPORT:
+		return true;
+	}
+
+	return false;
+}
+
+/**
+ * batadv_mcast_forw_mode_check_ipv6() - check for optimized forwarding
+ *  potential
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: the IPv6 packet to check
+ * @is_unsnoopable: stores whether the destination is snoopable
+ *
+ * Checks whether the given IPv6 packet has the potential to be forwarded with a
+ * mode more optimal than classic flooding.
+ *
+ * Return: If so then 0. Otherwise -EINVAL is or -ENOMEM if we are out of memory
+ */
+static int batadv_mcast_forw_mode_check_ipv6(struct batadv_priv *bat_priv,
+					     struct sk_buff *skb,
+					     bool *is_unsnoopable)
+{
+	struct ipv6hdr *ip6hdr;
+
+	/* We might fail due to out-of-memory -> drop it */
+	if (!pskb_may_pull(skb, sizeof(struct ethhdr) + sizeof(*ip6hdr)))
+		return -ENOMEM;
+
+	if (batadv_mcast_is_report_ipv6(skb))
+		return -EINVAL;
+
+	ip6hdr = ipv6_hdr(skb);
+
+	/* TODO: Implement Multicast Router Discovery (RFC4286),
+	 * then allow scope > link local, too
+	 */
+	if (IPV6_ADDR_MC_SCOPE(&ip6hdr->daddr) != IPV6_ADDR_SCOPE_LINKLOCAL)
+		return -EINVAL;
+
+	/* link-local-all-nodes multicast listeners behind a bridge are
+	 * not snoopable (see RFC4541, section 3, paragraph 3)
+	 */
+	if (ipv6_addr_is_ll_all_nodes(&ip6hdr->daddr))
+		*is_unsnoopable = true;
+
+	return 0;
+}
+
+/**
+ * batadv_mcast_forw_mode_check() - check for optimized forwarding potential
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: the multicast frame to check
+ * @is_unsnoopable: stores whether the destination is snoopable
+ *
+ * Checks whether the given multicast ethernet frame has the potential to be
+ * forwarded with a mode more optimal than classic flooding.
+ *
+ * Return: If so then 0. Otherwise -EINVAL is or -ENOMEM if we are out of memory
+ */
+static int batadv_mcast_forw_mode_check(struct batadv_priv *bat_priv,
+					struct sk_buff *skb,
+					bool *is_unsnoopable)
+{
+	struct ethhdr *ethhdr = eth_hdr(skb);
+
+	if (!atomic_read(&bat_priv->multicast_mode))
+		return -EINVAL;
+
+	switch (ntohs(ethhdr->h_proto)) {
+	case ETH_P_IP:
+		return batadv_mcast_forw_mode_check_ipv4(bat_priv, skb,
+							 is_unsnoopable);
+	case ETH_P_IPV6:
+		if (!IS_ENABLED(CONFIG_IPV6))
+			return -EINVAL;
+
+		return batadv_mcast_forw_mode_check_ipv6(bat_priv, skb,
+							 is_unsnoopable);
+	default:
+		return -EINVAL;
+	}
+}
+
+/**
+ * batadv_mcast_forw_want_all_ip_count() - count nodes with unspecific mcast
+ *  interest
+ * @bat_priv: the bat priv with all the soft interface information
+ * @ethhdr: ethernet header of a packet
+ *
+ * Return: the number of nodes which want all IPv4 multicast traffic if the
+ * given ethhdr is from an IPv4 packet or the number of nodes which want all
+ * IPv6 traffic if it matches an IPv6 packet.
+ */
+static int batadv_mcast_forw_want_all_ip_count(struct batadv_priv *bat_priv,
+					       struct ethhdr *ethhdr)
+{
+	switch (ntohs(ethhdr->h_proto)) {
+	case ETH_P_IP:
+		return atomic_read(&bat_priv->mcast.num_want_all_ipv4);
+	case ETH_P_IPV6:
+		return atomic_read(&bat_priv->mcast.num_want_all_ipv6);
+	default:
+		/* we shouldn't be here... */
+		return 0;
+	}
+}
+
+/**
+ * batadv_mcast_forw_tt_node_get() - get a multicast tt node
+ * @bat_priv: the bat priv with all the soft interface information
+ * @ethhdr: the ether header containing the multicast destination
+ *
+ * Return: an orig_node matching the multicast address provided by ethhdr
+ * via a translation table lookup. This increases the returned nodes refcount.
+ */
+static struct batadv_orig_node *
+batadv_mcast_forw_tt_node_get(struct batadv_priv *bat_priv,
+			      struct ethhdr *ethhdr)
+{
+	return batadv_transtable_search(bat_priv, NULL, ethhdr->h_dest,
+					BATADV_NO_FLAGS);
+}
+
+/**
+ * batadv_mcast_forw_ipv4_node_get() - get a node with an ipv4 flag
+ * @bat_priv: the bat priv with all the soft interface information
+ *
+ * Return: an orig_node which has the BATADV_MCAST_WANT_ALL_IPV4 flag set and
+ * increases its refcount.
+ */
+static struct batadv_orig_node *
+batadv_mcast_forw_ipv4_node_get(struct batadv_priv *bat_priv)
+{
+	struct batadv_orig_node *tmp_orig_node, *orig_node = NULL;
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(tmp_orig_node,
+				 &bat_priv->mcast.want_all_ipv4_list,
+				 mcast_want_all_ipv4_node) {
+		if (!kref_get_unless_zero(&tmp_orig_node->refcount))
+			continue;
+
+		orig_node = tmp_orig_node;
+		break;
+	}
+	rcu_read_unlock();
+
+	return orig_node;
+}
+
+/**
+ * batadv_mcast_forw_ipv6_node_get() - get a node with an ipv6 flag
+ * @bat_priv: the bat priv with all the soft interface information
+ *
+ * Return: an orig_node which has the BATADV_MCAST_WANT_ALL_IPV6 flag set
+ * and increases its refcount.
+ */
+static struct batadv_orig_node *
+batadv_mcast_forw_ipv6_node_get(struct batadv_priv *bat_priv)
+{
+	struct batadv_orig_node *tmp_orig_node, *orig_node = NULL;
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(tmp_orig_node,
+				 &bat_priv->mcast.want_all_ipv6_list,
+				 mcast_want_all_ipv6_node) {
+		if (!kref_get_unless_zero(&tmp_orig_node->refcount))
+			continue;
+
+		orig_node = tmp_orig_node;
+		break;
+	}
+	rcu_read_unlock();
+
+	return orig_node;
+}
+
+/**
+ * batadv_mcast_forw_ip_node_get() - get a node with an ipv4/ipv6 flag
+ * @bat_priv: the bat priv with all the soft interface information
+ * @ethhdr: an ethernet header to determine the protocol family from
+ *
+ * Return: an orig_node which has the BATADV_MCAST_WANT_ALL_IPV4 or
+ * BATADV_MCAST_WANT_ALL_IPV6 flag, depending on the provided ethhdr, set and
+ * increases its refcount.
+ */
+static struct batadv_orig_node *
+batadv_mcast_forw_ip_node_get(struct batadv_priv *bat_priv,
+			      struct ethhdr *ethhdr)
+{
+	switch (ntohs(ethhdr->h_proto)) {
+	case ETH_P_IP:
+		return batadv_mcast_forw_ipv4_node_get(bat_priv);
+	case ETH_P_IPV6:
+		return batadv_mcast_forw_ipv6_node_get(bat_priv);
+	default:
+		/* we shouldn't be here... */
+		return NULL;
+	}
+}
+
+/**
+ * batadv_mcast_forw_unsnoop_node_get() - get a node with an unsnoopable flag
+ * @bat_priv: the bat priv with all the soft interface information
+ *
+ * Return: an orig_node which has the BATADV_MCAST_WANT_ALL_UNSNOOPABLES flag
+ * set and increases its refcount.
+ */
+static struct batadv_orig_node *
+batadv_mcast_forw_unsnoop_node_get(struct batadv_priv *bat_priv)
+{
+	struct batadv_orig_node *tmp_orig_node, *orig_node = NULL;
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(tmp_orig_node,
+				 &bat_priv->mcast.want_all_unsnoopables_list,
+				 mcast_want_all_unsnoopables_node) {
+		if (!kref_get_unless_zero(&tmp_orig_node->refcount))
+			continue;
+
+		orig_node = tmp_orig_node;
+		break;
+	}
+	rcu_read_unlock();
+
+	return orig_node;
+}
+
+/**
+ * batadv_mcast_forw_mode() - check on how to forward a multicast packet
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: The multicast packet to check
+ * @orig: an originator to be set to forward the skb to
+ *
+ * Return: the forwarding mode as enum batadv_forw_mode and in case of
+ * BATADV_FORW_SINGLE set the orig to the single originator the skb
+ * should be forwarded to.
+ */
+enum batadv_forw_mode
+batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
+		       struct batadv_orig_node **orig)
+{
+	int ret, tt_count, ip_count, unsnoop_count, total_count;
+	bool is_unsnoopable = false;
+	struct ethhdr *ethhdr;
+
+	ret = batadv_mcast_forw_mode_check(bat_priv, skb, &is_unsnoopable);
+	if (ret == -ENOMEM)
+		return BATADV_FORW_NONE;
+	else if (ret < 0)
+		return BATADV_FORW_ALL;
+
+	ethhdr = eth_hdr(skb);
+
+	tt_count = batadv_tt_global_hash_count(bat_priv, ethhdr->h_dest,
+					       BATADV_NO_FLAGS);
+	ip_count = batadv_mcast_forw_want_all_ip_count(bat_priv, ethhdr);
+	unsnoop_count = !is_unsnoopable ? 0 :
+			atomic_read(&bat_priv->mcast.num_want_all_unsnoopables);
+
+	total_count = tt_count + ip_count + unsnoop_count;
+
+	switch (total_count) {
+	case 1:
+		if (tt_count)
+			*orig = batadv_mcast_forw_tt_node_get(bat_priv, ethhdr);
+		else if (ip_count)
+			*orig = batadv_mcast_forw_ip_node_get(bat_priv, ethhdr);
+		else if (unsnoop_count)
+			*orig = batadv_mcast_forw_unsnoop_node_get(bat_priv);
+
+		if (*orig)
+			return BATADV_FORW_SINGLE;
+
+		/* fall through */
+	case 0:
+		return BATADV_FORW_NONE;
+	default:
+		return BATADV_FORW_ALL;
+	}
+}
+
+/**
+ * batadv_mcast_forw_send_orig() - send a multicast packet to an originator
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: the multicast packet to send
+ * @vid: the vlan identifier
+ * @orig_node: the originator to send the packet to
+ *
+ * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
+ */
+int batadv_mcast_forw_send_orig(struct batadv_priv *bat_priv,
+				struct sk_buff *skb,
+				unsigned short vid,
+				struct batadv_orig_node *orig_node)
+{
+	/* Avoid sending multicast-in-unicast packets to other BLA
+	 * gateways - they already got the frame from the LAN side
+	 * we share with them.
+	 * TODO: Refactor to take BLA into account earlier, to avoid
+	 * reducing the mcast_fanout count.
+	 */
+	if (batadv_bla_is_backbone_gw_orig(bat_priv, orig_node->orig, vid)) {
+		dev_kfree_skb(skb);
+		return NET_XMIT_SUCCESS;
+	}
+
+	return batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST, 0,
+				       orig_node, vid);
+}
+
+/**
+ * batadv_mcast_want_unsnoop_update() - update unsnoop counter and list
+ * @bat_priv: the bat priv with all the soft interface information
+ * @orig: the orig_node which multicast state might have changed of
+ * @mcast_flags: flags indicating the new multicast state
+ *
+ * If the BATADV_MCAST_WANT_ALL_UNSNOOPABLES flag of this originator,
+ * orig, has toggled then this method updates counter and list accordingly.
+ *
+ * Caller needs to hold orig->mcast_handler_lock.
+ */
+static void batadv_mcast_want_unsnoop_update(struct batadv_priv *bat_priv,
+					     struct batadv_orig_node *orig,
+					     u8 mcast_flags)
+{
+	struct hlist_node *node = &orig->mcast_want_all_unsnoopables_node;
+	struct hlist_head *head = &bat_priv->mcast.want_all_unsnoopables_list;
+
+	lockdep_assert_held(&orig->mcast_handler_lock);
+
+	/* switched from flag unset to set */
+	if (mcast_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES &&
+	    !(orig->mcast_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES)) {
+		atomic_inc(&bat_priv->mcast.num_want_all_unsnoopables);
+
+		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
+		/* flag checks above + mcast_handler_lock prevents this */
+		WARN_ON(!hlist_unhashed(node));
+
+		hlist_add_head_rcu(node, head);
+		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
+	/* switched from flag set to unset */
+	} else if (!(mcast_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) &&
+		   orig->mcast_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) {
+		atomic_dec(&bat_priv->mcast.num_want_all_unsnoopables);
+
+		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
+		/* flag checks above + mcast_handler_lock prevents this */
+		WARN_ON(hlist_unhashed(node));
+
+		hlist_del_init_rcu(node);
+		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
+	}
+}
+
+/**
+ * batadv_mcast_want_ipv4_update() - update want-all-ipv4 counter and list
+ * @bat_priv: the bat priv with all the soft interface information
+ * @orig: the orig_node which multicast state might have changed of
+ * @mcast_flags: flags indicating the new multicast state
+ *
+ * If the BATADV_MCAST_WANT_ALL_IPV4 flag of this originator, orig, has
+ * toggled then this method updates counter and list accordingly.
+ *
+ * Caller needs to hold orig->mcast_handler_lock.
+ */
+static void batadv_mcast_want_ipv4_update(struct batadv_priv *bat_priv,
+					  struct batadv_orig_node *orig,
+					  u8 mcast_flags)
+{
+	struct hlist_node *node = &orig->mcast_want_all_ipv4_node;
+	struct hlist_head *head = &bat_priv->mcast.want_all_ipv4_list;
+
+	lockdep_assert_held(&orig->mcast_handler_lock);
+
+	/* switched from flag unset to set */
+	if (mcast_flags & BATADV_MCAST_WANT_ALL_IPV4 &&
+	    !(orig->mcast_flags & BATADV_MCAST_WANT_ALL_IPV4)) {
+		atomic_inc(&bat_priv->mcast.num_want_all_ipv4);
+
+		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
+		/* flag checks above + mcast_handler_lock prevents this */
+		WARN_ON(!hlist_unhashed(node));
+
+		hlist_add_head_rcu(node, head);
+		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
+	/* switched from flag set to unset */
+	} else if (!(mcast_flags & BATADV_MCAST_WANT_ALL_IPV4) &&
+		   orig->mcast_flags & BATADV_MCAST_WANT_ALL_IPV4) {
+		atomic_dec(&bat_priv->mcast.num_want_all_ipv4);
+
+		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
+		/* flag checks above + mcast_handler_lock prevents this */
+		WARN_ON(hlist_unhashed(node));
+
+		hlist_del_init_rcu(node);
+		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
+	}
+}
+
+/**
+ * batadv_mcast_want_ipv6_update() - update want-all-ipv6 counter and list
+ * @bat_priv: the bat priv with all the soft interface information
+ * @orig: the orig_node which multicast state might have changed of
+ * @mcast_flags: flags indicating the new multicast state
+ *
+ * If the BATADV_MCAST_WANT_ALL_IPV6 flag of this originator, orig, has
+ * toggled then this method updates counter and list accordingly.
+ *
+ * Caller needs to hold orig->mcast_handler_lock.
+ */
+static void batadv_mcast_want_ipv6_update(struct batadv_priv *bat_priv,
+					  struct batadv_orig_node *orig,
+					  u8 mcast_flags)
+{
+	struct hlist_node *node = &orig->mcast_want_all_ipv6_node;
+	struct hlist_head *head = &bat_priv->mcast.want_all_ipv6_list;
+
+	lockdep_assert_held(&orig->mcast_handler_lock);
+
+	/* switched from flag unset to set */
+	if (mcast_flags & BATADV_MCAST_WANT_ALL_IPV6 &&
+	    !(orig->mcast_flags & BATADV_MCAST_WANT_ALL_IPV6)) {
+		atomic_inc(&bat_priv->mcast.num_want_all_ipv6);
+
+		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
+		/* flag checks above + mcast_handler_lock prevents this */
+		WARN_ON(!hlist_unhashed(node));
+
+		hlist_add_head_rcu(node, head);
+		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
+	/* switched from flag set to unset */
+	} else if (!(mcast_flags & BATADV_MCAST_WANT_ALL_IPV6) &&
+		   orig->mcast_flags & BATADV_MCAST_WANT_ALL_IPV6) {
+		atomic_dec(&bat_priv->mcast.num_want_all_ipv6);
+
+		spin_lock_bh(&bat_priv->mcast.want_lists_lock);
+		/* flag checks above + mcast_handler_lock prevents this */
+		WARN_ON(hlist_unhashed(node));
+
+		hlist_del_init_rcu(node);
+		spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
+	}
+}
+
+/**
+ * batadv_mcast_tvlv_ogm_handler() - process incoming multicast tvlv container
+ * @bat_priv: the bat priv with all the soft interface information
+ * @orig: the orig_node of the ogm
+ * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
+ * @tvlv_value: tvlv buffer containing the multicast data
+ * @tvlv_value_len: tvlv buffer length
+ */
+static void batadv_mcast_tvlv_ogm_handler(struct batadv_priv *bat_priv,
+					  struct batadv_orig_node *orig,
+					  u8 flags,
+					  void *tvlv_value,
+					  u16 tvlv_value_len)
+{
+	bool orig_mcast_enabled = !(flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
+	u8 mcast_flags = BATADV_NO_FLAGS;
+
+	if (orig_mcast_enabled && tvlv_value &&
+	    tvlv_value_len >= sizeof(mcast_flags))
+		mcast_flags = *(u8 *)tvlv_value;
+
+	if (!orig_mcast_enabled) {
+		mcast_flags |= BATADV_MCAST_WANT_ALL_IPV4;
+		mcast_flags |= BATADV_MCAST_WANT_ALL_IPV6;
+	}
+
+	spin_lock_bh(&orig->mcast_handler_lock);
+
+	if (orig_mcast_enabled &&
+	    !test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities)) {
+		set_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities);
+	} else if (!orig_mcast_enabled &&
+		   test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities)) {
+		clear_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities);
+	}
+
+	set_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capa_initialized);
+
+	batadv_mcast_want_unsnoop_update(bat_priv, orig, mcast_flags);
+	batadv_mcast_want_ipv4_update(bat_priv, orig, mcast_flags);
+	batadv_mcast_want_ipv6_update(bat_priv, orig, mcast_flags);
+
+	orig->mcast_flags = mcast_flags;
+	spin_unlock_bh(&orig->mcast_handler_lock);
+}
+
+/**
+ * batadv_mcast_init() - initialize the multicast optimizations structures
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+void batadv_mcast_init(struct batadv_priv *bat_priv)
+{
+	batadv_tvlv_handler_register(bat_priv, batadv_mcast_tvlv_ogm_handler,
+				     NULL, BATADV_TVLV_MCAST, 2,
+				     BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
+
+	INIT_DELAYED_WORK(&bat_priv->mcast.work, batadv_mcast_mla_update);
+	batadv_mcast_start_timer(bat_priv);
+}
+
+#ifdef CONFIG_BATMAN_ADV_DEBUGFS
+/**
+ * batadv_mcast_flags_print_header() - print own mcast flags to debugfs table
+ * @bat_priv: the bat priv with all the soft interface information
+ * @seq: debugfs table seq_file struct
+ *
+ * Prints our own multicast flags including a more specific reason why
+ * they are set, that is prints the bridge and querier state too, to
+ * the debugfs table specified via @seq.
+ */
+static void batadv_mcast_flags_print_header(struct batadv_priv *bat_priv,
+					    struct seq_file *seq)
+{
+	u8 flags = bat_priv->mcast.flags;
+	char querier4, querier6, shadowing4, shadowing6;
+	bool bridged = bat_priv->mcast.bridged;
+
+	if (bridged) {
+		querier4 = bat_priv->mcast.querier_ipv4.exists ? '.' : '4';
+		querier6 = bat_priv->mcast.querier_ipv6.exists ? '.' : '6';
+		shadowing4 = bat_priv->mcast.querier_ipv4.shadowing ? '4' : '.';
+		shadowing6 = bat_priv->mcast.querier_ipv6.shadowing ? '6' : '.';
+	} else {
+		querier4 = '?';
+		querier6 = '?';
+		shadowing4 = '?';
+		shadowing6 = '?';
+	}
+
+	seq_printf(seq, "Multicast flags (own flags: [%c%c%c])\n",
+		   (flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) ? 'U' : '.',
+		   (flags & BATADV_MCAST_WANT_ALL_IPV4) ? '4' : '.',
+		   (flags & BATADV_MCAST_WANT_ALL_IPV6) ? '6' : '.');
+	seq_printf(seq, "* Bridged [U]\t\t\t\t%c\n", bridged ? 'U' : '.');
+	seq_printf(seq, "* No IGMP/MLD Querier [4/6]:\t\t%c/%c\n",
+		   querier4, querier6);
+	seq_printf(seq, "* Shadowing IGMP/MLD Querier [4/6]:\t%c/%c\n",
+		   shadowing4, shadowing6);
+	seq_puts(seq, "-------------------------------------------\n");
+	seq_printf(seq, "       %-10s %s\n", "Originator", "Flags");
+}
+
+/**
+ * batadv_mcast_flags_seq_print_text() - print the mcast flags of other nodes
+ * @seq: seq file to print on
+ * @offset: not used
+ *
+ * This prints a table of (primary) originators and their according
+ * multicast flags, including (in the header) our own.
+ *
+ * Return: always 0
+ */
+int batadv_mcast_flags_seq_print_text(struct seq_file *seq, void *offset)
+{
+	struct net_device *net_dev = (struct net_device *)seq->private;
+	struct batadv_priv *bat_priv = netdev_priv(net_dev);
+	struct batadv_hard_iface *primary_if;
+	struct batadv_hashtable *hash = bat_priv->orig_hash;
+	struct batadv_orig_node *orig_node;
+	struct hlist_head *head;
+	u8 flags;
+	u32 i;
+
+	primary_if = batadv_seq_print_text_primary_if_get(seq);
+	if (!primary_if)
+		return 0;
+
+	batadv_mcast_flags_print_header(bat_priv, seq);
+
+	for (i = 0; i < hash->size; i++) {
+		head = &hash->table[i];
+
+		rcu_read_lock();
+		hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
+			if (!test_bit(BATADV_ORIG_CAPA_HAS_MCAST,
+				      &orig_node->capa_initialized))
+				continue;
+
+			if (!test_bit(BATADV_ORIG_CAPA_HAS_MCAST,
+				      &orig_node->capabilities)) {
+				seq_printf(seq, "%pM -\n", orig_node->orig);
+				continue;
+			}
+
+			flags = orig_node->mcast_flags;
+
+			seq_printf(seq, "%pM [%c%c%c]\n", orig_node->orig,
+				   (flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES)
+				   ? 'U' : '.',
+				   (flags & BATADV_MCAST_WANT_ALL_IPV4)
+				   ? '4' : '.',
+				   (flags & BATADV_MCAST_WANT_ALL_IPV6)
+				   ? '6' : '.');
+		}
+		rcu_read_unlock();
+	}
+
+	batadv_hardif_put(primary_if);
+
+	return 0;
+}
+#endif
+
+/**
+ * batadv_mcast_mesh_info_put() - put multicast info into a netlink message
+ * @msg: buffer for the message
+ * @bat_priv: the bat priv with all the soft interface information
+ *
+ * Return: 0 or error code.
+ */
+int batadv_mcast_mesh_info_put(struct sk_buff *msg,
+			       struct batadv_priv *bat_priv)
+{
+	u32 flags = bat_priv->mcast.flags;
+	u32 flags_priv = BATADV_NO_FLAGS;
+
+	if (bat_priv->mcast.bridged) {
+		flags_priv |= BATADV_MCAST_FLAGS_BRIDGED;
+
+		if (bat_priv->mcast.querier_ipv4.exists)
+			flags_priv |= BATADV_MCAST_FLAGS_QUERIER_IPV4_EXISTS;
+		if (bat_priv->mcast.querier_ipv6.exists)
+			flags_priv |= BATADV_MCAST_FLAGS_QUERIER_IPV6_EXISTS;
+		if (bat_priv->mcast.querier_ipv4.shadowing)
+			flags_priv |= BATADV_MCAST_FLAGS_QUERIER_IPV4_SHADOWING;
+		if (bat_priv->mcast.querier_ipv6.shadowing)
+			flags_priv |= BATADV_MCAST_FLAGS_QUERIER_IPV6_SHADOWING;
+	}
+
+	if (nla_put_u32(msg, BATADV_ATTR_MCAST_FLAGS, flags) ||
+	    nla_put_u32(msg, BATADV_ATTR_MCAST_FLAGS_PRIV, flags_priv))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+/**
+ * batadv_mcast_flags_dump_entry() - dump one entry of the multicast flags table
+ *  to a netlink socket
+ * @msg: buffer for the message
+ * @portid: netlink port
+ * @seq: Sequence number of netlink message
+ * @orig_node: originator to dump the multicast flags of
+ *
+ * Return: 0 or error code.
+ */
+static int
+batadv_mcast_flags_dump_entry(struct sk_buff *msg, u32 portid, u32 seq,
+			      struct batadv_orig_node *orig_node)
+{
+	void *hdr;
+
+	hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family,
+			  NLM_F_MULTI, BATADV_CMD_GET_MCAST_FLAGS);
+	if (!hdr)
+		return -ENOBUFS;
+
+	if (nla_put(msg, BATADV_ATTR_ORIG_ADDRESS, ETH_ALEN,
+		    orig_node->orig)) {
+		genlmsg_cancel(msg, hdr);
+		return -EMSGSIZE;
+	}
+
+	if (test_bit(BATADV_ORIG_CAPA_HAS_MCAST,
+		     &orig_node->capabilities)) {
+		if (nla_put_u32(msg, BATADV_ATTR_MCAST_FLAGS,
+				orig_node->mcast_flags)) {
+			genlmsg_cancel(msg, hdr);
+			return -EMSGSIZE;
+		}
+	}
+
+	genlmsg_end(msg, hdr);
+	return 0;
+}
+
+/**
+ * batadv_mcast_flags_dump_bucket() - dump one bucket of the multicast flags
+ *  table to a netlink socket
+ * @msg: buffer for the message
+ * @portid: netlink port
+ * @seq: Sequence number of netlink message
+ * @head: bucket to dump
+ * @idx_skip: How many entries to skip
+ *
+ * Return: 0 or error code.
+ */
+static int
+batadv_mcast_flags_dump_bucket(struct sk_buff *msg, u32 portid, u32 seq,
+			       struct hlist_head *head, long *idx_skip)
+{
+	struct batadv_orig_node *orig_node;
+	long idx = 0;
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
+		if (!test_bit(BATADV_ORIG_CAPA_HAS_MCAST,
+			      &orig_node->capa_initialized))
+			continue;
+
+		if (idx < *idx_skip)
+			goto skip;
+
+		if (batadv_mcast_flags_dump_entry(msg, portid, seq,
+						  orig_node)) {
+			rcu_read_unlock();
+			*idx_skip = idx;
+
+			return -EMSGSIZE;
+		}
+
+skip:
+		idx++;
+	}
+	rcu_read_unlock();
+
+	return 0;
+}
+
+/**
+ * __batadv_mcast_flags_dump() - dump multicast flags table to a netlink socket
+ * @msg: buffer for the message
+ * @portid: netlink port
+ * @seq: Sequence number of netlink message
+ * @bat_priv: the bat priv with all the soft interface information
+ * @bucket: current bucket to dump
+ * @idx: index in current bucket to the next entry to dump
+ *
+ * Return: 0 or error code.
+ */
+static int
+__batadv_mcast_flags_dump(struct sk_buff *msg, u32 portid, u32 seq,
+			  struct batadv_priv *bat_priv, long *bucket, long *idx)
+{
+	struct batadv_hashtable *hash = bat_priv->orig_hash;
+	long bucket_tmp = *bucket;
+	struct hlist_head *head;
+	long idx_tmp = *idx;
+
+	while (bucket_tmp < hash->size) {
+		head = &hash->table[bucket_tmp];
+
+		if (batadv_mcast_flags_dump_bucket(msg, portid, seq, head,
+						   &idx_tmp))
+			break;
+
+		bucket_tmp++;
+		idx_tmp = 0;
+	}
+
+	*bucket = bucket_tmp;
+	*idx = idx_tmp;
+
+	return msg->len;
+}
+
+/**
+ * batadv_mcast_netlink_get_primary() - get primary interface from netlink
+ *  callback
+ * @cb: netlink callback structure
+ * @primary_if: the primary interface pointer to return the result in
+ *
+ * Return: 0 or error code.
+ */
+static int
+batadv_mcast_netlink_get_primary(struct netlink_callback *cb,
+				 struct batadv_hard_iface **primary_if)
+{
+	struct batadv_hard_iface *hard_iface = NULL;
+	struct net *net = sock_net(cb->skb->sk);
+	struct net_device *soft_iface;
+	struct batadv_priv *bat_priv;
+	int ifindex;
+	int ret = 0;
+
+	ifindex = batadv_netlink_get_ifindex(cb->nlh, BATADV_ATTR_MESH_IFINDEX);
+	if (!ifindex)
+		return -EINVAL;
+
+	soft_iface = dev_get_by_index(net, ifindex);
+	if (!soft_iface || !batadv_softif_is_valid(soft_iface)) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	bat_priv = netdev_priv(soft_iface);
+
+	hard_iface = batadv_primary_if_get_selected(bat_priv);
+	if (!hard_iface || hard_iface->if_status != BATADV_IF_ACTIVE) {
+		ret = -ENOENT;
+		goto out;
+	}
+
+out:
+	if (soft_iface)
+		dev_put(soft_iface);
+
+	if (!ret && primary_if)
+		*primary_if = hard_iface;
+	else if (hard_iface)
+		batadv_hardif_put(hard_iface);
+
+	return ret;
+}
+
+/**
+ * batadv_mcast_flags_dump() - dump multicast flags table to a netlink socket
+ * @msg: buffer for the message
+ * @cb: callback structure containing arguments
+ *
+ * Return: message length.
+ */
+int batadv_mcast_flags_dump(struct sk_buff *msg, struct netlink_callback *cb)
+{
+	struct batadv_hard_iface *primary_if = NULL;
+	int portid = NETLINK_CB(cb->skb).portid;
+	struct batadv_priv *bat_priv;
+	long *bucket = &cb->args[0];
+	long *idx = &cb->args[1];
+	int ret;
+
+	ret = batadv_mcast_netlink_get_primary(cb, &primary_if);
+	if (ret)
+		return ret;
+
+	bat_priv = netdev_priv(primary_if->soft_iface);
+	ret = __batadv_mcast_flags_dump(msg, portid, cb->nlh->nlmsg_seq,
+					bat_priv, bucket, idx);
+
+	batadv_hardif_put(primary_if);
+	return ret;
+}
+
+/**
+ * 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)
+{
+	cancel_delayed_work_sync(&bat_priv->mcast.work);
+
+	batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_MCAST, 2);
+	batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_MCAST, 2);
+
+	/* safely calling outside of worker, as worker was canceled above */
+	batadv_mcast_mla_tt_retract(bat_priv, NULL);
+}
+
+/**
+ * batadv_mcast_purge_orig() - reset originator global mcast state modifications
+ * @orig: the originator which is going to get purged
+ */
+void batadv_mcast_purge_orig(struct batadv_orig_node *orig)
+{
+	struct batadv_priv *bat_priv = orig->bat_priv;
+
+	spin_lock_bh(&orig->mcast_handler_lock);
+
+	batadv_mcast_want_unsnoop_update(bat_priv, orig, BATADV_NO_FLAGS);
+	batadv_mcast_want_ipv4_update(bat_priv, orig, BATADV_NO_FLAGS);
+	batadv_mcast_want_ipv6_update(bat_priv, orig, BATADV_NO_FLAGS);
+
+	spin_unlock_bh(&orig->mcast_handler_lock);
+}