Re: [PATCH net] bridge: do not add port to router list when receives query with source 0.0.0.0

[Nikolay Aleksandrov <nikolay@cumulusnetworks.com>]

On 26/10/2018 05:28, Hangbin Liu wrote:
> Based on RFC 4541, 2.1.1.  IGMP Forwarding Rules
> 
>   The switch supporting IGMP snooping must maintain a list of
>   multicast routers and the ports on which they are attached.  This
>   list can be constructed in any combination of the following ways:
> 
>   a) This list should be built by the snooping switch sending
>      Multicast Router Solicitation messages as described in IGMP
>      Multicast Router Discovery [MRDISC].  It may also snoop
>      Multicast Router Advertisement messages sent by and to other
>      nodes.
> 
>   b) The arrival port for IGMP Queries (sent by multicast routers)
>      where the source address is not 0.0.0.0.
> 
> We should not add the port to router list when receives query with source
> 0.0.0.0.
> 
> Reported-by: Ying Xu <yinxu@redhat.com>
> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
> ---
>  net/bridge/br_multicast.c | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
> index 024139b..41cdafb 100644
> --- a/net/bridge/br_multicast.c
> +++ b/net/bridge/br_multicast.c
> @@ -1422,7 +1422,15 @@ static void br_multicast_query_received(struct net_bridge *br,
>  		return;
>  
>  	br_multicast_update_query_timer(br, query, max_delay);
> -	br_multicast_mark_router(br, port);
> +
> +	/* Based on RFC4541, section 2.1.1 IGMP Forwarding Rules,
> +	 * the arrival port for IGMP Queries where the source address
> +	 * is 0.0.0.0 should not be added to router port list.
> +	 */
> +	if ((saddr->proto == htons(ETH_P_IP) && saddr->u.ip4) ||
> +	    (saddr->proto == htons(ETH_P_IPV6) &&
> +	     !ipv6_addr_any(&saddr->u.ip6)))
> +		br_multicast_mark_router(br, port);
>  }
>  
>  static void br_ip4_multicast_query(struct net_bridge *br,
> 

+CC Roopa & bridge@lists.linux-foundation.org