We don't actually have a stdio.h header file. Our printf() functions are
defined in vsprintf.h. (This may change, since vsprintf.h is a
non-standard name, but for now it's the one to use.)
There should be no need to include vsprintf.h just for DBG() statements,
since include/compiler.h forces it in for a debug build anyway.
Make the UDP senddata() methods return a status code.
udp_connect() now follows the standard BSD sockets semantics and simply
sets the default address for outgoing packets; it doesn't filter incoming
packets.
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.
Split DHCP packet creation into two parts: creating the basic packet
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.
Add sketch code to reassemble a DHCP packet from our internal "everything
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.