This allows distinguishing multiple modems by specifying another
loopback ip i.e. -i 127.0.0.4
Linux has a default local route for 127.0.0.0/8 so it "just works".
This forwards the raw DIAG messages via GSMTAP, so the receiver (e.g.
wireshark) will have to do a full DIAG protocol decode. I currently
prefer this idea to that of converting only the protocol payload to
"native" GSMTAP messages like GSMTAP_UM.
One of the problems is that the LAPDm headers are alrady stripped, and
we would have to re-add fake LAPDm headers to generate GSMTAP_UM. So
let's rather forward all information we have and let wireshark deal with
it.
I'm not entirely sure if this is the best strategy, but we can always
implement both modes and switch between them at runtime.
Eric Wild
Harald Welte
Martin Hauke