Re: [PATCH net-next (v3)] ipv6: add anti-spoofing checks for 6to4 and 6rd

[David Miller <davem@davemloft.net>]

From: Hannes Frederic Sowa <hannes@stressinduktion.org>
Date: Tue, 29 Jan 2013 19:24:25 +0100

> This patch adds anti-spoofing checks in sit.c as specified in RFC3964
> section 5.2 for 6to4 and RFC5969 section 12 for 6rd. I left out the
> checks which could easily be implemented with netfilter.
> 
> Specifically this patch adds following logic (based loosely on the
> pseudocode in RFC3964 section 5.2):
> 
> if prefix (inner_src_v6) == rd6_prefix (2002::/16 is the default)
>         and outer_src_v4 != embedded_ipv4 (inner_src_v6)
>                 drop
> if prefix (inner_dst_v6) == rd6_prefix (or 2002::/16 is the default)
>         and outer_dst_v4 != embedded_ipv4 (inner_dst_v6)
>                 drop
> accept
> 
> To accomplish the specified security checks proposed by above RFCs,
> it is still necessary to employ uRPF filters with netfilter. These new
> checks only kick in if the employed addresses are within the 2002::/16 or
> another range specified by the 6rd-prefix (which defaults to 2002::/16).
> 
> Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
> Cc: David Miller <davem@davemloft.net>
> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>

Applied.