Parameter request list is yet another option that ISC dhcpd ignores
unless it's in the main options block.

Fix logic error in parsing file and sname fields.

cycle.  :)

doesn't seem to be required by the RFCs, but at least ISC dhcpd and
ethereal refuse to recognise it otherwise.

packets.

(apart from the bad UDP checksum).

functions that return status codes.

Zero the DHCP packet buffer *before* creating the options structures
inside it.

parsed DHCP responses.

structure, and populating it with options.  This should allow us to
use the same basic options list for both DHCPDISCOVER and DHCPREQUEST,
plus making it much easier to set the non-constant parameters
(e.g. requested IP address) in request packets.

derived is a 16-bit big-endian field, but htype is only 8 bits wide.

is a DHCP option" data structures.

We need this code in order to be able to return a DHCP packet to a PXE NBP
which reflects options from our multiple sources (e.g. NVS and DHCP
server).  This is expensive, but necessary.  Having paid this cost, we may
as well try to use the same code to generate our DHCP request packets,
since the process is similar.

DHCP options block from the contents.