Wireshark Error During Loading

[JeffHochberg]

Hello,

I'm attempting to use the LUA plugins with Wireshark 2.6 on Windows 7 SP1 x64. When I reload the LUA plugins, I'm getting an error on line 174 in the xcmp.lua plugin:

Lua: Error during loading:
[string "C:\Program Files\Wireshark\plugins\2.6\xcmp.l..."]:174: bad argument #1 to
'new' (Field_new: a field with this name must exist)

If I open the xcmp.lua file, I see the following (lines 173 to 175):

-- dofile("xnl.luainc") -- uncomment to fix dependency order
local xnl_opcode = Field.new("xnl.opcode")
local xnl_transaction = Field.new("xnl.transaction")

The lines already appear to have been uncommented. I haven't tried to see what happens when commenting them out. I assume that they are uncommented because they are required.

I found the following article on Google that sounds similar to what's going on here but I'm stuck at this point:

https://osqa-ask.wireshark.org/questions/34562/lua-bad-argument-1-to-fieldnew-a-field-with-this-name-must-exist)

Any thoughts as to what might be happening here?

[george-hopkins]

Unfortunately, Wireshark does not load Lua files in a stable way. As you discovered, xcmp.lua is sometimes loaded before xnl.lua. To work around this issue, you can rename xnl.lua to xnl.luainc and uncomment dofile("xnl.luainc").

[BobDucker55]

I have followed the above instruction and now get an error at line 173 (dofile: file does not exist)

[aagedh]

I have followed the above instruction and now get an error at line 173 (dofile: file does not exist)

same error her. win 11. wireshark 4.2.6

[george-hopkins]

It might not work because in your case xnl.lua is in a subfolder. Can you check if it works with dofile("xcmp-xnl-dissector-master/xnl.lua")?

[kjkriegel]

I ran into the same problem even with both files in the root of the plugins folder. Switching to an absolute path for xnl.lua in the dofile statement solved the problem.

[aagedh]

It might not work because in your case xnl.lua is in a subfolder. Can you check if it works with dofile("xcmp-xnl-dissector-master/xnl.lua")?

did not work. tried moving to plugin and the version directory. still the same,

[aagedh]

one step closer with absolute path. now i get another issue.
How do i specify that wireshark loads this plugin with an absolute path?

[gunjubas]

1. For win - place files in %APPDATA%\Wireshark\plugins\
2. Than change name for xnl.lua to something else (for example xnl.luainc)
3. Modify line 174 and set location of xnl.luainc something like (with doubleescaping backslashes)
   dofile('C:\\Users\\!!!YourUserNameHereDontForgetToChangeThis!!!\\AppData\\Roaming\\Wireshark\\plugins\\xnl.luainc')

[Quphoria]

The solution for this is actually quite easy, wireshark loads LUA files in alphabetical order
Rename the LUA files to 0_xnl.lua and 1_xcmp.lua so wireshark loads xnl.lua before xcmp.lua

See: Lua Support in Wireshark

[gunjubas]

@Quphoria Great decision. Thanks for clarifying