[Lazarus] FreePascal TCPIP data tunnel code sample?

[Koenraad Lelong]

Op 05-02-16 om 14:20 schreef Bo Berglund:
> On Thu, 4 Feb 2016 21:10:54 +0100, Koenraad Lelong
> <lazarus2 at de-brouwerij.be> wrote:
>
>> Op 04-02-16 om 17:17 schreef Bo Berglund:
>>> Then whatever data comes in through the Ethernet port should be sent
>>> via the WiFi connection to the instrument.
>>> All data received from the instrument should be sent out to the
>>> connected client on the Ethernet connection.
>>> So the program I am looking for should not do anything at all with the
>>> data content, except transfer byte-by-byte between the networks.
>>>
>>> And this should be running on a Raspberry Pi2B so it can be easily
>>> deployed in the place the instrument is located. Meanwhile I can sit
>>> in another building and test the actual client code.
>>>
>>> Is there something like this available already?
>>>
>>>
>> Hi,
>>
>> Isn't this just port-forwarding ? Set up the firewall to forward data to
>> the wired NIC to the device's address and port.
>>
> Which firewall?
> But you are right in the port forwarding part. I want my new RPi2 unit
> to forward the communications on port 1001 on the Ethernet side to a
> specific unit on the WiFi side on its 1001 port.
>

Every linux-machine, and the pi is no exception, has a firewall : 
iptables. You could configure it manually, but myself, I prefer 
shorewall to configure the firewall.

Koenraad.