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

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

[Hannes Frederic Sowa]

Cc: Erik Hugne <erik.hugne@ericsson.com>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
---
 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);
 
-- 
1.8.1.2

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

[YOSHIFUJI Hideaki]

Hannes Frederic Sowa wrote:
> Cc: Erik Hugne <erik.hugne@ericsson.com>
> Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
> ---
>  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 <yoshfuji@linux-ipv6.org>

--yoshfuji

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

[Hannes Frederic Sowa]

On Sun, Feb 10, 2013 at 01:48:51PM +0100, Hannes Frederic Sowa wrote:
> +	/*
> +	 * 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.

Just nit-picking: The field is actually called scop without e, as pointed out
by three erratas to RFC4291. :)

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

[David Miller]

From: Hannes Frederic Sowa <hannes@stressinduktion.org>
Date: Mon, 11 Feb 2013 20:48:35 +0100

> On Sun, Feb 10, 2013 at 01:48:51PM +0100, Hannes Frederic Sowa wrote:
>> +	/*
>> +	 * 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.
> 
> Just nit-picking: The field is actually called scop without e, as pointed out
> by three erratas to RFC4291. :)

That's funny because I added the 'e' to your patches while applying
them, it just looks completely stupid to refer to this things as
'scop'.

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

[Ben Hutchings]

On Mon, 2013-02-11 at 14:52 -0500, David Miller wrote:
> From: Hannes Frederic Sowa <hannes@stressinduktion.org>
> Date: Mon, 11 Feb 2013 20:48:35 +0100
> 
> > On Sun, Feb 10, 2013 at 01:48:51PM +0100, Hannes Frederic Sowa wrote:
> >> +	/*
> >> +	 * 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.
> > 
> > Just nit-picking: The field is actually called scop without e, as pointed out
> > by three erratas to RFC4291. :)
> 
> That's funny because I added the 'e' to your patches while applying
> them, it just looks completely stupid to refer to this things as
> 'scop'.

It seems to be a long Unix tradition to creat names with trailing silent
vowels removed; this is hardly uniq.

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

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

[Stephen Hemminger]

On Mon, 11 Feb 2013 22:21:11 +0000
Ben Hutchings <bhutchings@solarflare.com> wrote:

> On Mon, 2013-02-11 at 14:52 -0500, David Miller wrote:
> > From: Hannes Frederic Sowa <hannes@stressinduktion.org>
> > Date: Mon, 11 Feb 2013 20:48:35 +0100
> > 
> > > On Sun, Feb 10, 2013 at 01:48:51PM +0100, Hannes Frederic Sowa wrote:
> > >> +	/*
> > >> +	 * 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.
> > > 
> > > Just nit-picking: The field is actually called scop without e, as pointed out
> > > by three erratas to RFC4291. :)
> > 
> > That's funny because I added the 'e' to your patches while applying
> > them, it just looks completely stupid to refer to this things as
> > 'scop'.
> 
> It seems to be a long Unix tradition to creat names with trailing silent
> vowels removed; this is hardly uniq.
> 
> Ben.
> 

Aussie's would call it scopie

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

[Dan Williams]

On Mon, 2013-02-11 at 22:21 +0000, Ben Hutchings wrote:
> On Mon, 2013-02-11 at 14:52 -0500, David Miller wrote:
> > From: Hannes Frederic Sowa <hannes@stressinduktion.org>
> > Date: Mon, 11 Feb 2013 20:48:35 +0100
> > 
> > > On Sun, Feb 10, 2013 at 01:48:51PM +0100, Hannes Frederic Sowa wrote:
> > >> +	/*
> > >> +	 * 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.
> > > 
> > > Just nit-picking: The field is actually called scop without e, as pointed out
> > > by three erratas to RFC4291. :)
> > 
> > That's funny because I added the 'e' to your patches while applying
> > them, it just looks completely stupid to refer to this things as
> > 'scop'.
> 
> It seems to be a long Unix tradition to creat names with trailing silent
> vowels removed; this is hardly uniq.

You had to buy vowels from Pat back then, and people were stingy with
their hard-earned money.  And then if you got the vowel wrong it was no
longer your turn.  So understandably people were reluctant to use vowels
much.

Dan