Layer2 Wireshark integration

[Harald Welte]

Hi!

I've recycled the old GSMTAP wireshark plugin that I originally wrote
for project airprobe.

Using this patch (now in our git tree as well, applies against current
wireshark svn) and the layer2 host program as well as the l1test.bin target
program, you can watch BCCH messages in realtime.

The architecture is like this:

* DSP forwards decoded normal burst data to layer1/sync.c
* layer1/sync.c generates L1A_L23 protocol message and sends it
  via the SERCOMM HDLC layer over RS232
* "osmocon" receives the HDLC frame and relays it to the Unix domain
  socket
* "layer2" receives the L1A_L23 protocol message on the Unix domain
  socket, adds a GSMTAP header and sends it to the GSMTAP UDP port on
  localhost
* wireshark captures on the 'lo' interface and calls the GSMTAP dissector
  plugin for everything received on the GSMTAP UDP port number.

Have fun!
-- 
- Harald Welte <laforge at gnumonks.org>           http://laforge.gnumonks.org/
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