kernel-aes67/net/batman-adv/multicast.h

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/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (C) B.A.T.M.A.N. contributors:
*
* Linus Lüssing
*/
#ifndef _NET_BATMAN_ADV_MULTICAST_H_
#define _NET_BATMAN_ADV_MULTICAST_H_
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#include "main.h"
#include <linux/netlink.h>
#include <linux/skbuff.h>
#include <linux/types.h>
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/**
* enum batadv_forw_mode - the way a packet should be forwarded as
*/
enum batadv_forw_mode {
/**
* @BATADV_FORW_BCAST: forward the packet to all nodes via a batman-adv
* broadcast packet
*/
BATADV_FORW_BCAST,
/**
* @BATADV_FORW_UCASTS: forward the packet to some nodes via one
* or more batman-adv unicast packets
*/
BATADV_FORW_UCASTS,
/**
* @BATADV_FORW_MCAST: forward the packet to some nodes via a
* batman-adv multicast packet
*/
BATADV_FORW_MCAST,
/** @BATADV_FORW_NONE: don't forward, drop it */
BATADV_FORW_NONE,
};
#ifdef CONFIG_BATMAN_ADV_MCAST
enum batadv_forw_mode
batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
unsigned short vid, int *is_routable);
int batadv_mcast_forw_send(struct batadv_priv *bat_priv, struct sk_buff *skb,
unsigned short vid, int is_routable);
void batadv_mcast_init(struct batadv_priv *bat_priv);
int batadv_mcast_mesh_info_put(struct sk_buff *msg,
struct batadv_priv *bat_priv);
int batadv_mcast_flags_dump(struct sk_buff *msg, struct netlink_callback *cb);
void batadv_mcast_free(struct batadv_priv *bat_priv);
void batadv_mcast_purge_orig(struct batadv_orig_node *orig_node);
/* multicast_forw.c */
int batadv_mcast_forw_tracker_tvlv_handler(struct batadv_priv *bat_priv,
struct sk_buff *skb);
unsigned int batadv_mcast_forw_packet_hdrlen(unsigned int num_dests);
bool batadv_mcast_forw_push(struct batadv_priv *bat_priv, struct sk_buff *skb,
unsigned short vid, int is_routable, int count);
int batadv_mcast_forw_mcsend(struct batadv_priv *bat_priv, struct sk_buff *skb);
#else
static inline enum batadv_forw_mode
batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
unsigned short vid, int *is_routable)
{
return BATADV_FORW_BCAST;
batman-adv: mcast: fix duplicate mcast packets in BLA backbone from LAN Scenario: * Multicast frame send from a BLA backbone (multiple nodes with their bat0 bridged together, with BLA enabled) Issue: * BLA backbone nodes receive the frame multiple times on bat0 For multicast frames received via batman-adv broadcast packets the originator of the broadcast packet is checked before decapsulating and forwarding the frame to bat0 (batadv_bla_is_backbone_gw()-> batadv_recv_bcast_packet()). If it came from a node which shares the same BLA backbone with us then it is not forwarded to bat0 to avoid a loop. When sending a multicast frame in a non-4-address batman-adv unicast packet we are currently missing this check - and cannot do so because the batman-adv unicast packet has no originator address field. However, we can simply fix this on the sender side by only sending the multicast frame via unicasts to interested nodes which do not share the same BLA backbone with us. This also nicely avoids some unnecessary transmissions on mesh side. Note that no infinite loop was observed, probably because of dropping via batadv_interface_tx()->batadv_bla_tx(). However the duplicates still utterly confuse switches/bridges, ICMPv6 duplicate address detection and neighbor discovery and therefore leads to long delays before being able to establish TCP connections, for instance. And it also leads to the Linux bridge printing messages like: "br-lan: received packet on eth1 with own address as source address ..." Fixes: 2d3f6ccc4ea5 ("batman-adv: Modified forwarding behaviour for multicast packets") Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue> Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
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}
static inline int
batadv_mcast_forw_send(struct batadv_priv *bat_priv, struct sk_buff *skb,
unsigned short vid, int is_routable)
{
kfree_skb(skb);
return NET_XMIT_DROP;
}
static inline int batadv_mcast_init(struct batadv_priv *bat_priv)
{
return 0;
}
static inline int
batadv_mcast_mesh_info_put(struct sk_buff *msg, struct batadv_priv *bat_priv)
{
return 0;
}
static inline int batadv_mcast_flags_dump(struct sk_buff *msg,
struct netlink_callback *cb)
{
return -EOPNOTSUPP;
}
static inline void batadv_mcast_free(struct batadv_priv *bat_priv)
{
}
static inline void batadv_mcast_purge_orig(struct batadv_orig_node *orig_node)
{
}
static inline int batadv_mcast_forw_mcsend(struct batadv_priv *bat_priv,
struct sk_buff *skb)
{
kfree_skb(skb);
return NET_XMIT_DROP;
}
#endif /* CONFIG_BATMAN_ADV_MCAST */
#endif /* _NET_BATMAN_ADV_MULTICAST_H_ */