BPF reading+writing

[Craig Metz <cmetz_(_at_)_inner_(_dot_)_net>]

  Has anyone worked with BPF doing both reading and writing?

  I'm finding that, if I have it set up to receive all packets off an interface
and write a packet to that interface, it also loops the packet I just wrote
back into the receive queue. Is there a way to prevent this from happenning?
I can squash this in userland by keeping around a checksum of packets I
recently wrote out, but that's a pretty gross hack.

									-Craig