Question about tunnels, IPsec and redirect

[Kevin Wilson]

Hi,
I am looking at this patch:
http://lists.openwall.net/netdev/2007/08/24/29
and I cannot understand it. Can somebody please try
to explain ?
more specifically:
Can somebody please give an example of some setup of IPsec tunnel
where the ip_rt_send_redirect() method should not be called when the
skb->sp is not NULL ?
(in other words, why if the SKB is and IPsec SKB, we should not send a
redirect in such a case while forwarding a packet; note I am talking
about  IPv4)

Note that the check for skb->sp was changed in recent kernels to
skb_sec_path(skb), but it is essentially the same.


Regards,
Kevin