Network packet parsing routine

[Petr Laznovsky]

Utilizing PacketSender console utility, receiving 'UBNT discovery packet'
(https://github.com/nitefood/python-ubnt-discovery/blob/master/ubnt_discovery.py) and trying to
parse it for 'UBNT field types' (see link) content. Program output few lines (each line, one packet)
of spaces separated HEXA bytes. I am currently able to convert HEXA bytes into DEC or ASCII values
(see bottom), but not able get parsing logic :-/

Packet structure is following:

01 00 00 90 <-> 02 <-> 00 0A <-> DC 9F DB 40 2E 40 0A 0C 66 E3 .. .. .. .. .. .. .. ..

After four initial bytes, there is "constant" 02, than size of following content 00 0A (decadic 10),
and than content itself (MAC + IP in this case). This three items repeatedly makes whole packet´s
content. Rewriting whole routine three times, still cant get the right point. Do not expect full
code, only put me to right way please, because I am lost....

thanks, L.




:hex2dec
for /f %%a in ('set /a "0x%~1"') do set "%~2=%%~a"
GOTO:EOF

:hex2asc
REM == Replacing hexadecimal strings with its ASCII representation characters ==
call :hex_prep %~1
set "arg1=%str%"
set "arg1=%arg1:\x=0x%"
forfiles /p "%~dp0." /m "%~nx0" /c "cmd /c echo(%arg1% > clip"
GOTO:EOF

:hex_prep
REM == Replace spaces by '\' and insert 'x' string before each token ===========
set "str="
:loop
if not "%str%"=="" (set "str=%str%\x%~1") else (set "str=\x%~1")
shift
if not "%~1"=="" goto loop
GOTO:EOF