Subject: Re: [PATCH] ipv6: don't accept multicast traffic with scop 0

From: YOSHIFUJI Hideaki <[email-masked]>
Date: Sun, 10 Feb 2013 23:56:02 +0900

Hannes Frederic Sowa wrote:
> Cc: Erik Hugne <[email-masked]>
> Cc: YOSHIFUJI Hideaki <[email-masked]>
> Signed-off-by: Hannes Frederic Sowa <[email-masked]>
> ---
>  net/ipv6/ip6_input.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
> index 4ac5bf3..34ddebd 100644
> --- a/net/ipv6/ip6_input.c
> +++ b/net/ipv6/ip6_input.c
> @@ -126,6 +126,16 @@ int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt
>  	if (ipv6_addr_is_multicast(&hdr->saddr))
>  		goto err;
>  
> +	/*
> +	 * RFC4291 2.7
> +	 * Nodes must not originate a packet to a multicast address whose scop
> +	 * field contains the reserved value 0; if such a packet is received, it
> +	 * must be silently dropped.
> +	 */
> +	if (ipv6_addr_is_multicast(&hdr->daddr) &&
> +	    IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 0)
> +		goto err;
> +
>  	skb->transport_header = skb->network_header + sizeof(*hdr);
>  	IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
>  
> 

Would you place this before saddr check, just after loopback check, please?
Otherwise,

Acked-by: YOSHIFUJI Hideaki <[email-masked]>

--yoshfuji