DHCP 4.0.0 and newer can not longer be compiled with USE_SOCKETS

[sthaug at nethelp.no]

DHCP 4.0.0 and newer can not longer be compiled with USE_SOCKETS defined
in site.h.

This is due to two problems:

- ./configure, at least on my FreeBSD 7.0-STABLE system, results in
USE_BPF being defined in all cases. It gets defined as:

#define USE_BPF ""

which is a kind of strange definition (I would expect it to be defined
as 1 if it is going to be used).

- If I manually comment out the USE_BPF definition, I get an undefined
get_hw_addr() at link time - this is called from if_register_socket()
in socket.c and is defined in bpf.c.

I would like to use USE_SOCKETS in order to have a DHCP server without
the whole BPF machinery, since *all* my DHCP requests are unicast -
either via a relay agent or directly from the client. But it looks like
this is currently not possible on 4.0.0 and newer code.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no