Re: [Bug 155] Outgoing MLD packets are not traversing netfilter

Harald,

1) ip6_tables not matching it as icmp6 packet

Just a guess, but if netfilter6 doesn't go through all
the extension headers, then the protocol won't look like
ICMP6 because of the router alert option.

2) ip6_queue copying the linklayer header to userspace

   >This means that skb->data does not point at the beginning of the
   >ipv6 packet (i.e. skb->data != skb->nh.ip6h), but to the beginning of
   >the hardware header (i.e. skb->data == skb->head).
   >
   >This is because mcast.c writes the full packet including the hardware
   >header and _then_ calls NF_HOOK.  All other code (ipv6 or ipv4) is
   >building the layer 3 packet, then calling NF_HOOK and later on (via
   >ipX_outpur_finish() or dst_output()) adding the hardware header.

...

So the fundamental question (with regard to the ipv6 gods) is:  Is it
really necessarry that the ipv6 mcast code bypasses the destination
cache?

      It can't go through the routing table. The advertisements
are only meaningful on the particular interface, whether or not
there is a route pointing output multicasts to a different
interface (which is useful frequently, but MLD packets can't
go there too).

                              +-DLS