Wireshark Lua dissector plugin table error

0
votes

I have packet with trailer data after the packet as in ixia timestamp trailer. I am trying to write a dissector for Wireshark that is quite the same as ixia-packet_trailer plugin. https://raw.githubusercontent.com/boundary/wireshark/master/epan/dissectors/packet-ixiatrailer.c

But i wanted to write in Lua, so it is easiest to change. So i replace the C line 

heur_dissector_add("eth.trailer", dissect_ixiatrailer, proto_ixiatrailer);

by the following in the Lua

eth_table = DissectorTable.get("eth.trailer")

But i got error from Wireshark "bad argument to get (DissectorTable_get no such dissector table)"

1
luawireshark
do you want the dissector or the the dissector table? maybe try Dissector.get instead of DissectorTable.get - Piglet
@Piglet in the examples it is DissectorTable, i tried what you proposed and it give an error also No such dissector - davidbobo

1 Answers

1
votes

Since "eth.trailer" is registered as a heuristic list (see packet-eth.c), I think you'll probably need to follow the example provided here: https://mika-s.github.io/wireshark/lua/dissector/2018/12/30/creating-port-independent-wireshark-dissectors-in-lua.html

Basically, I think you're going to need to do something like so:

your_protocol:register_heuristic("eth.trailer", heuristic_checker)

... where heuristic_checker is the function that checks if the trailer is in fact for your dissector or not.