Re: [RFC] [GIT PATCH] IPv6 Routing / Ndisc Fixes

David Miller
2006-08-24T00:40:16Z

From: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Date: Thu, 10 Aug 2006 17:46:35 +0900 (JST)

> Hello.
>
> In article <44DA558A.1080706@tcs.hut.fi> (at Thu, 10 Aug 2006 00:37:14 +0300), Ville Nuorvala <vnuorval@tcs.hut.fi> says:
>
> > >> commit e0ad64d5b44179ea1296d737dec23279c72c9636
> > >> Author: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
> > >> Date: Wed Aug 9 17:08:33 2006 +0900
> > >>
> > >> [IPV6] NDISC: Allow redirects from other interfaces if it is not strict.
> > >>
> > >> Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
> > >>
> > >> diff --git a/net/ipv6/route.c b/net/ipv6/route.c
> > >> index 4650787..1698fec 100644
> > >> --- a/net/ipv6/route.c
> > >> +++ b/net/ipv6/route.c
> > >> @@ -1322,7 +1322,7 @@ restart:
> > >> continue;
> > >> if (!(rt->rt6i_flags & RTF_GATEWAY))
> > >> continue;
> > >> - if (fl->oif != rt->rt6i_dev->ifindex)
> > >> + if ((flags & RT6_F_STRICT) && fl->oif != rt->rt6i_dev->ifindex)
> > >> continue;
> > >> if (!ipv6_addr_equal(&rdfl->gateway, &rt->rt6i_gateway))
> > >> continue;
> > >>
> > >
> > > Is this absolutely safe? Doesn't this enable a malicious node on another
> > > link to make a bogus redirect if it uses same link-local source address
> > > as the real router on the other link. Keep in mind that the RT6_F_STRICT
> > > flag is set based on the destination of the original redirected packet
> > > and doesn't in any way depend on the router or source address.
> :
>
> Ah, you're right. I'll drop this.

Ok, I integrated all of these changes, dropping this RT6_F_STRICT
changeset, and integrating all of Ville's sign offs and ACKs.

It is all in the net-2.6.19 tree, thanks a lot.

I will start to review the MIPV6 patches next.