linux/net/batman-adv/multicast.h
Linus Lüssing 938f2e0b57 batman-adv: mcast: don't send link-local multicast to mcast routers
The addition of routable multicast TX handling introduced a
bug/regression for packets with a link-local multicast destination:
These packets would be sent to all batman-adv nodes with a multicast
router and to all batman-adv nodes with an old version without multicast
router detection.

This even disregards the batman-adv multicast fanout setting, which can
potentially lead to an unwanted, high number of unicast transmissions or
even congestion.

Fixing this by avoiding to send link-local multicast packets to nodes in
the multicast router list.

Fixes: 11d458c1cb ("batman-adv: mcast: apply optimizations for routable packets, too")
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>
2022-01-02 09:31:17 +01:00

124 lines
2.8 KiB
C

/* 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_
#include "main.h"
#include <linux/netlink.h>
#include <linux/skbuff.h>
/**
* enum batadv_forw_mode - the way a packet should be forwarded as
*/
enum batadv_forw_mode {
/**
* @BATADV_FORW_ALL: forward the packet to all nodes (currently via
* classic flooding)
*/
BATADV_FORW_ALL,
/**
* @BATADV_FORW_SOME: forward the packet to some nodes (currently via
* a multicast-to-unicast conversion and the BATMAN unicast routing
* protocol)
*/
BATADV_FORW_SOME,
/**
* @BATADV_FORW_SINGLE: forward the packet to a single node (currently
* via the BATMAN unicast routing protocol)
*/
BATADV_FORW_SINGLE,
/** @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,
struct batadv_orig_node **mcast_single_orig,
int *is_routable);
int batadv_mcast_forw_send_orig(struct batadv_priv *bat_priv,
struct sk_buff *skb,
unsigned short vid,
struct batadv_orig_node *orig_node);
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);
#else
static inline enum batadv_forw_mode
batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
struct batadv_orig_node **mcast_single_orig,
int *is_routable)
{
return BATADV_FORW_ALL;
}
static inline int
batadv_mcast_forw_send_orig(struct batadv_priv *bat_priv,
struct sk_buff *skb,
unsigned short vid,
struct batadv_orig_node *orig_node)
{
kfree_skb(skb);
return NET_XMIT_DROP;
}
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)
{
}
#endif /* CONFIG_BATMAN_ADV_MCAST */
#endif /* _NET_BATMAN_ADV_MULTICAST_H_ */