Messages in this thread |  | | | Date | Mon, 24 Jan 2011 18:02:13 +0100 | | From | "Mario 'BitKoenig' Holbe" <> | | Subject | Re: netfilter: marking IPv6 packets sends them to the wrong interface |
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On Mon, Jan 24, 2011 at 05:10:50PM +0100, Patrick McHardy wrote: > > Yes, disabling the ip6_route_me_harder() call in ip6t_mangle_out() > > results in the advertisements being transmitted on the correct > > interfaces > Thanks. The problem appears to be that ip6_route_me_harder() > only uses the socket's oif for the route lookup when the > socket is bound to an interface, but radvd uses IPV6_PKTINFO > to specify the outgoing interface. > > I guess netfilter shouldn't be overriding IPV6_PKTINFO, but > we unfortunately have neither an indication of this nor the > original route lookup keys available at the time the packet > is rerouted.
Mh, I'm not sure, but I guess an indication of netfilter not overriding IPV6_PKTINFO could be the fact that the source address does not change...
From my 1st mail: | # ip6tables -t mangle -A OUTPUT -o eth0 -j MARK --set-mark 1 | # /etc/init.d/radvd start | -> eth0: <no traffic> | -> eth1: fe80::2a0:c9ff:fee6:90ce > ff02::1: prefix 2001:6f8:90c:10::/64 | -> eth1: fe80::2d0:b7ff:fe06:6b36 > ff02::1: prefix 2001:6f8:90c:12::/64
fe80::2d0:b7ff:fe06:6b36 is the link-local address of eth0 set by radvd in IPV6_PKTINFO as well. This, of course, is no guarantee for ipi6_ifindex not being changed, but I believe if something would have changed it, it would also have changed ipi6_addr.
Mario -- Doing it right is no excuse for not meeting the schedule. -- Plant Manager, Delphi Corporation [unhandled content-type:application/pgp-signature] |  |