I suspect this breaks proxy arp/ndisc!

The arp/ndisc requests are queued up for a random time before being
processed by the proxy. Check out pneigh_enqueue() in net/core/neighbour.c
for details. The skb->stamp.tv_sec check was used to separate the locally
re-fed requests from ones received from the net.

Ok, thanks for clarifying this. I guessed the intention wrong then.

A better way may be to just add a new skb flag for this that is managed
by the arp code? Comments?

-Andi