ipv6 multicast forwarding

I have a concern with ipv6 multicast!! But I don't know "linux forwarding" well

I inserted 2 lines in ip6_mc_input()

	....
	if (ipv6_chk_mcast_addr(skb->dev, &hdr->daddr))
		deliver =1;

	>>if (ipv6_devconf.forwarding == 1)
	>>	ip6_mc_forward(skb, deliver);

	if (deliver)
		discard = 0;
		ip6_input(skb);
	}
	......

I made ip6_mc_forward() which was modified from ip6_forward().

But it doesn't work...
How do I make ip6_mc_forward()?

I want simple ipv6 multicast forward...
When host receive multicast packet, host forward it without multicast
routing cache..
Then I will filter unneeded packets.

Nobody help me??
Thank you!!