Commit 07afe1ba authored by Linus Lüssing's avatar Linus Lüssing Committed by Simon Wunderlich
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batman-adv: mcast: implement multicast packet reception and forwarding 



Implement functionality to receive and forward a new TVLV capable
multicast packet type.

The new batman-adv multicast packet type allows to contain several
originator destination addresses within a TVLV. Routers on the way will
potentially split the batman-adv multicast packet and adjust its tracker
TVLV contents.

Routing decisions are still based on the selected BATMAN IV or BATMAN V
routing algorithm. So this new batman-adv multicast packet type retains
the same loop-free properties.

Also a new OGM multicast TVLV flag is introduced to signal to other
nodes that we are capable of handling a batman-adv multicast packet and
multicast tracker TVLV. And that all of our hard interfaces have an MTU
of at least 1280 bytes (IPv6 minimum MTU), as a simple solution for now
to avoid MTU issues while forwarding.

Signed-off-by: default avatarLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: default avatarSimon Wunderlich <sw@simonwunderlich.de>
parent e4679a1b

include/uapi/linux/batadv_packet.h

+39 −6
Original line number Diff line number Diff line
@@ -116,6 +116,9 @@ enum batadv_icmp_packettype { 
 * only need routable IPv4 multicast packets we signed up for explicitly

 * @BATADV_MCAST_WANT_NO_RTR6: we have no IPv6 multicast router and therefore

 * only need routable IPv6 multicast packets we signed up for explicitly

 * @BATADV_MCAST_HAVE_MC_PTYPE_CAPA: we can parse, receive and forward

 * batman-adv multicast packets with a multicast tracker TVLV. And all our

 * hard interfaces have an MTU of at least 1280 bytes.

 */

enum batadv_mcast_flags {

	BATADV_MCAST_WANT_ALL_UNSNOOPABLES	= 1UL << 0,
@@ -123,6 +126,7 @@ enum batadv_mcast_flags { 
	BATADV_MCAST_WANT_ALL_IPV6		= 1UL << 2,

	BATADV_MCAST_WANT_NO_RTR4		= 1UL << 3,

	BATADV_MCAST_WANT_NO_RTR6		= 1UL << 4,

	BATADV_MCAST_HAVE_MC_PTYPE_CAPA		= 1UL << 5,

};



/* tt data subtypes */
@@ -174,6 +178,7 @@ enum batadv_bla_claimframe { 
 * @BATADV_TVLV_TT: translation table tvlv

 * @BATADV_TVLV_ROAM: roaming advertisement tvlv

 * @BATADV_TVLV_MCAST: multicast capability tvlv

 * @BATADV_TVLV_MCAST_TRACKER: multicast tracker tvlv

 */

enum batadv_tvlv_type {

	BATADV_TVLV_GW			= 0x01,
@@ -182,6 +187,7 @@ enum batadv_tvlv_type { 
	BATADV_TVLV_TT			= 0x04,

	BATADV_TVLV_ROAM		= 0x05,

	BATADV_TVLV_MCAST		= 0x06,

	BATADV_TVLV_MCAST_TRACKER	= 0x07,

};



#pragma pack(2)
@@ -487,6 +493,25 @@ struct batadv_bcast_packet { 
	 */

};



/**

 * struct batadv_mcast_packet - multicast packet for network payload

 * @packet_type: batman-adv packet type, part of the general header

 * @version: batman-adv protocol version, part of the general header

 * @ttl: time to live for this packet, part of the general header

 * @reserved: reserved byte for alignment

 * @tvlv_len: length of the appended tvlv buffer (in bytes)

 */

struct batadv_mcast_packet {

	__u8 packet_type;

	__u8 version;

	__u8 ttl;

	__u8 reserved;

	__be16 tvlv_len;

	/* "4 bytes boundary + 2 bytes" long to make the payload after the

	 * following ethernet header again 4 bytes boundary aligned

	 */

};



/**

 * struct batadv_coded_packet - network coded packet

 * @packet_type: batman-adv packet type, part of the general header
@@ -628,6 +653,14 @@ struct batadv_tvlv_mcast_data { 
	__u8 reserved[3];

};



/**

 * struct batadv_tvlv_mcast_tracker - payload of a multicast tracker tvlv

 * @num_dests: number of subsequent destination originator MAC addresses

 */

struct batadv_tvlv_mcast_tracker {

	__be16	num_dests;

};



#pragma pack()



#endif /* _UAPI_LINUX_BATADV_PACKET_H_ */

net/batman-adv/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ batman-adv-y += hash.o 
batman-adv-$(CONFIG_BATMAN_ADV_DEBUG) += log.o

batman-adv-y += main.o

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

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

batman-adv-y += netlink.o

batman-adv-$(CONFIG_BATMAN_ADV_NC) += network-coding.o

batman-adv-y += originator.o

net/batman-adv/fragmentation.c

+1 −7
Original line number Diff line number Diff line
@@ -25,7 +25,6 @@ 


#include "hard-interface.h"

#include "originator.h"

#include "routing.h"

#include "send.h"



/**
@@ -351,18 +350,14 @@ bool batadv_frag_skb_fwd(struct sk_buff *skb, 
			 struct batadv_orig_node *orig_node_src)

{

	struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);

	struct batadv_orig_node *orig_node_dst;

	struct batadv_neigh_node *neigh_node = NULL;

	struct batadv_frag_packet *packet;

	u16 total_size;

	bool ret = false;



	packet = (struct batadv_frag_packet *)skb->data;

	orig_node_dst = batadv_orig_hash_find(bat_priv, packet->dest);

	if (!orig_node_dst)

		goto out;



	neigh_node = batadv_find_router(bat_priv, orig_node_dst, recv_if);

	neigh_node = batadv_orig_to_router(bat_priv, packet->dest, recv_if);

	if (!neigh_node)

		goto out;
@@ -381,7 +376,6 @@ bool batadv_frag_skb_fwd(struct sk_buff *skb, 
	}



out:

	batadv_orig_node_put(orig_node_dst);

	batadv_neigh_node_put(neigh_node);

	return ret;

}

net/batman-adv/main.c

+2 −0
Original line number Diff line number Diff line
@@ -532,6 +532,8 @@ static void batadv_recv_handler_init(void) 


	/* broadcast packet */

	batadv_rx_handler[BATADV_BCAST] = batadv_recv_bcast_packet;

	/* multicast packet */

	batadv_rx_handler[BATADV_MCAST] = batadv_recv_mcast_packet;



	/* unicast packets ... */

	/* unicast with 4 addresses packet */

net/batman-adv/multicast.c

+43 −5
Original line number Diff line number Diff line
@@ -235,6 +235,37 @@ static u8 batadv_mcast_mla_rtr_flags_get(struct batadv_priv *bat_priv, 
	return flags;

}



/**

 * batadv_mcast_mla_forw_flags_get() - get multicast forwarding flags

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

 *

 * Checks if all active hard interfaces have an MTU larger or equal to 1280

 * bytes (IPv6 minimum MTU).

 *

 * Return: BATADV_MCAST_HAVE_MC_PTYPE_CAPA if yes, BATADV_NO_FLAGS otherwise.

 */

static u8 batadv_mcast_mla_forw_flags_get(struct batadv_priv *bat_priv)

{

	const struct batadv_hard_iface *hard_iface;



	rcu_read_lock();

	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {

		if (hard_iface->if_status != BATADV_IF_ACTIVE)

			continue;



		if (hard_iface->soft_iface != bat_priv->soft_iface)

			continue;



		if (hard_iface->net_dev->mtu < IPV6_MIN_MTU) {

			rcu_read_unlock();

			return BATADV_NO_FLAGS;

		}

	}

	rcu_read_unlock();



	return BATADV_MCAST_HAVE_MC_PTYPE_CAPA;

}



/**

 * batadv_mcast_mla_flags_get() - get the new multicast flags

 * @bat_priv: the bat priv with all the soft interface information
@@ -256,6 +287,7 @@ batadv_mcast_mla_flags_get(struct batadv_priv *bat_priv) 
	mla_flags.enabled = 1;

	mla_flags.tvlv_flags |= batadv_mcast_mla_rtr_flags_get(bat_priv,

							       bridge);

	mla_flags.tvlv_flags |= batadv_mcast_mla_forw_flags_get(bat_priv);



	if (!bridge)

		return mla_flags;
@@ -806,23 +838,25 @@ static void batadv_mcast_flags_log(struct batadv_priv *bat_priv, u8 flags) 
{

	bool old_enabled = bat_priv->mcast.mla_flags.enabled;

	u8 old_flags = bat_priv->mcast.mla_flags.tvlv_flags;

	char str_old_flags[] = "[.... . ]";

	char str_old_flags[] = "[.... . .]";



	sprintf(str_old_flags, "[%c%c%c%s%s]",

	sprintf(str_old_flags, "[%c%c%c%s%s%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' : '.',

		!(old_flags & BATADV_MCAST_WANT_NO_RTR4) ? "R4" : ". ",

		!(old_flags & BATADV_MCAST_WANT_NO_RTR6) ? "R6" : ". ");

		!(old_flags & BATADV_MCAST_WANT_NO_RTR6) ? "R6" : ". ",

		!(old_flags & BATADV_MCAST_HAVE_MC_PTYPE_CAPA) ? 'P' : '.');



	batadv_dbg(BATADV_DBG_MCAST, bat_priv,

		   "Changing multicast flags from '%s' to '[%c%c%c%s%s]'\n",

		   "Changing multicast flags from '%s' to '[%c%c%c%s%s%c]'\n",

		   old_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' : '.',

		   !(flags & BATADV_MCAST_WANT_NO_RTR4) ? "R4" : ". ",

		   !(flags & BATADV_MCAST_WANT_NO_RTR6) ? "R6" : ". ");

		   !(flags & BATADV_MCAST_WANT_NO_RTR6) ? "R6" : ". ",

		   !(flags & BATADV_MCAST_HAVE_MC_PTYPE_CAPA) ? 'P' : '.');

}



/**
@@ -1820,6 +1854,10 @@ void batadv_mcast_init(struct batadv_priv *bat_priv) 
	batadv_tvlv_handler_register(bat_priv, batadv_mcast_tvlv_ogm_handler,

				     NULL, NULL, BATADV_TVLV_MCAST, 2,

				     BATADV_TVLV_HANDLER_OGM_CIFNOTFND);

	batadv_tvlv_handler_register(bat_priv, NULL, NULL,

				     batadv_mcast_forw_tracker_tvlv_handler,

				     BATADV_TVLV_MCAST_TRACKER, 1,

				     BATADV_TVLV_HANDLER_OGM_CIFNOTFND);



	INIT_DELAYED_WORK(&bat_priv->mcast.work, batadv_mcast_mla_update);

	batadv_mcast_start_timer(bat_priv);