GUIDE: LUA unit testing and TDD

I've just uncovered this subject, here is my insights:

Fast start

1. Open LUA
2. Start a new test file (let's call it 'my_code.tests.lua').
3. Edit 'my_code.tests.lua' (example template below)

--- my_code.tests.lua Code --------------------------------------------

-- Some super function to test
function my_super_function( arg1, arg2 ) return arg1 + arg2 end

-- Unit testing starts
require('luaunit')

TestMyStuff = {} --class
    function TestMyStuff:testWithNumbers()
        a = 1
        b = 2
        result = my_super_function( a, b )
        assertEquals( type(result), 'number' )
        assertEquals( result, 3 )
    end

    function TestMyStuff:testWithRealNumbers()
        a = 1.1
        b = 2.2
        result = my_super_function( a, b )
        assertEquals( type(result), 'number' )
        -- I would like the result to be always rounded to an integer
        -- but it won't work with my simple implementation
        -- thus, the test will fail
        assertEquals( result, 3 )
    end

-- class TestMyStuff

luaUnit:run()

--- Code End -----------------------------------------------------------------------

Execute the test code.
Add your tests and assumption checking.
Fix what's broken.

Understand more

• http://phil.freehackers.org/programs/luaunit/
• http://lua-users.org/wiki/UnitTesting

LUA tutorial / newbie, nob getting started and advanced links.

NOB? here you go:

Fast start

• Download 'LUA For Windows' - A batteries included Lua installation on Windows.
• http://code.google.com/p/luaforwindows/downloads/list
• Write code in an online interpreter
• http://www.lua.org/cgi-bin/demo

Know your LUA

• http://en.wikipedia.org/wiki/Lua_(programming_language)

Reference cards

• Lua 5.1 Reference Manual
• http://www.tdistler.com/media/docs/luarefv51.pdf
• http://lua-users.org/wiki/
• http://www.lua.org/manual/5.1/

A bit more advanced stuff

• Dynamic invocation
• http://stackoverflow.com/questions/1791234/lua-call-function-from-a-string-with-function-name
• http://en.wikipedia.org/wiki/Eval#Lua
• BitwiseOperators
• http://lua-users.org/wiki/BitwiseOperators
• Recommended - http://bitop.luajit.org/
• Notes - Problems with unsigned numbers detected!

Integrating LUA with Eclipse

• http://lunareclipse.sourceforge.net/
• Download - http://sourceforge.net/projects/lunareclipse/

Hope this helps.

GUIDE: Creating your own fast Wireshark plugin / dissector using LUA.

After hitting my head agains the keyboard to create my own LUA protocol, I've desided that none shall suffer anymore.

Some background to understand stuff

• Wireshark reads PCAP file format for captured files.
• Wireshark can be extended using C code or, for fast development you can use LUA code (I'll explain later...).

• PCAP File Format

• Development/LibpcapFileFormat - The Wireshark Wiki
• Know your Wireshark
• http://www.wireshark.org/docs/

Creating LUA based plugin / dissector

1. Download and install Wireshark.
2. Create LUA dissector (let's save it as 'trivial.lua')

-- trivial protocol example
-- declare our protocol
trivial_proto = Proto("trivial","Trivial Protocol")
-- create a function to dissect it
function trivial_proto.dissector(buffer,pinfo,tree)
    pinfo.cols.protocol = "TRIVIAL"
    local subtree = tree:add(trivial_proto,buffer(),"Trivial Protocol Data")
    subtree:add(buffer(0,2),"The first two bytes: " .. buffer(0,2):uint())
    subtree = subtree:add(buffer(2,2),"The next two bytes")
    subtree:add(buffer(2,1),"The 3rd byte: " .. buffer(2,1):uint())
    subtree:add(buffer(3,1),"The 4th byte: " .. buffer(3,1):uint())
end
-- load the udp.port table
udp_table = DissectorTable.get("udp.port")
-- register our protocol to handle udp port 7777
udp_table:add(7777,trivial_proto)

1. Edit  ...\Wireshark\init.lua file as follows
1. disable_lua = false
2. At the end of the file: dofile("trivial.lua") 
1. You can read more here - http://simplestcodings.com/2011/01/09/how-to-use-lua-to-create-wireshark-dissector/
2. Open Wireshark
1. Menu >> Edit >> Preferences >> Protocols >> DLT_USER >> Edit >> New:
1. DLT: User 0 (147)
2. Payload protocol: MyProtocolName
3. Header size 0
4. Trailer size: 0
5. Press OK
3. Create PCAP dumps for analyze.
1. Using HEX-Editor (see below for nice hex-editor recomendations).
2. If you can - ask the protocol team to provide their dumps. 
4. Open the PCAP dump for editing (binary mode).
1. Change the dump's 'Global Header' section / 'data link type' (network) to 147 (LINKTYPE_USER0)
1. Read more here - http://www.tcpdump.org/linktypes.html
2. save it.
5. Load the dump to Wireshark for analyses.
6. Start changing the trivial.lua code to parse your protocol.

Hope this will bring you to a working point fast. In the process read related stuff to understand more, you can upgrade this solution to create better and better protocol sniffer using Wireshark.

• Related reference stuff
• http://simplestcodings.com/2011/01/09/how-to-use-lua-to-create-wireshark-dissector/
• http://delog.wordpress.com/2010/09/27/create-a-wireshark-dissector-in-lua/
• http://lua-users.org/wiki/TutorialDirectory
• http://wiki.wireshark.org/Lua
• http://wiki.wireshark.org/Lua/Dissectors
• http://wiki.wireshark.org/Lua/Examples

More nice stuff that can help

• You can use 'Hex Workshop' to simulate your protocol binary streams more easily (using it's feature Structure Editing).
• http://www.hexworkshop.com/screen_shots.html
• Wireshark tools
• http://wiki.wireshark.org/Tools
• bit-twist: Network Traffic Generator 
• http://www.blindhog.net/bit-twist-network-traffic-generator-and-editor-2/
• http://bittwist.sourceforge.net/

GUIDE: dotNetInstaller - Free fast and easy installer for windows

In a nutshell

1. Download dotNetInstaller: setup bootstrapper for Windows
1. Great tutorials:
1. http://www.codeproject.com/KB/install/dotNetInstaller.aspx
2. http://code.dblock.org/ShowPost.aspx?Id=118
2. Read this article if you're using 'Setup project using the Windows Installer'.
1. http://www.simple-talk.com/dotnet/visual-studio/updates-to-setup-projects/
3. Read this article if you'r using 'Install shield limited edition'.
1. http://blogs.msdn.com/b/somasegar/archive/2009/12/14/building-setup-and-deployment-packages-in-vs-2010.aspx
4. If using MSI file...
1. http://codefornothing.wordpress.com/2007/11/27/short-msi-tutorial/
2. http://technet.microsoft.com/en-us/library/cc759262(WS.10).aspx
3. http://www.advancedinstaller.com/user-guide/msiexec.html
4. http://www.robvanderwoude.com/msiexec.php

Command line utilities for the job

• http://www.pc-tools.net/dos/dosutils/

VB-Script macro to help you uninstall stuff

• http://support.microsoft.com/kb/308364
• http://www.w3schools.com/vbscript/vbscript_ref_functions.asp

REM Option Explicit

Dim exitcode : exitcode = 0

REM --- Functions ------------------------------------------------------------------


function readFromRegistry (strRegistryKey, strDefault )
    Dim value
 Dim objFSO, WSHShell

    On Error Resume Next
 Set objFSO   = CreateObject("Scripting.FileSystemObject")      
 Set WSHShell = CreateObject("Wscript.Shell")
    value = WSHShell.RegRead( strRegistryKey )

    if err.number <> 0 then
        readFromRegistry= strDefault
    else
        readFromRegistry=value
    end if

    set WSHShell = nothing
end function


function readDataFromMsiFile(file_path)
 Set objInstaller = CreateObject("WindowsInstaller.Installer")
 Set objProduct = objInstaller.SummaryInformation(file_path)
 Wscript.Echo "Code page: " &objProduct.Property(1)
 Wscript.Echo "Title: " & objProduct.Property(2)
 Wscript.Echo "Subject: " & objProduct.Property(3)
 Wscript.Echo "Author: " & objProduct.Property(4)
 Wscript.Echo "Keywords: " & objProduct.Property(5)
 Wscript.Echo "Comment: " & objProduct.Property(6)
 Wscript.Echo "Template: " & objProduct.Property(7)
 Wscript.Echo "Last Author: " & objProduct.Property(8)
 Wscript.Echo "Revision number: " & objProduct.Property(9)
 Wscript.Echo "Edit Time: " & objProduct.Property(10)
 Wscript.Echo "Last Printed: " & objProduct.Property(11)
 Wscript.Echo "Creation Date: " & objProduct.Property(12)
 Wscript.Echo "Last Saved: " & objProduct.Property(13)
 Wscript.Echo "Page Count: " & objProduct.Property(14)
 Wscript.Echo "Word Count: " & objProduct.Property(15)
 Wscript.Echo "Character Count: " & objProduct.Property(16)
 Wscript.Echo "Application Name: " & objProduct.Property(18)
 Wscript.Echo "Security: " & objProduct.Property(19)

 Set objProduct = Nothing
 Set objInstaller = Nothing

end function

function ProductVersion()
 ' SOURCE: http://stackoverflow.com/questions/815744/retrieving-version-of-an-msi-file-built-with-wix
 Dim installer, database, view, result

 Set installer = CreateObject("WindowsInstaller.Installer")
 Set database = installer.OpenDatabase (".\installer.msi", 0)

 Dim sumInfo  : Set sumInfo = installer.SummaryInformation(".\installer.msi", 0)
 sPackageCode =  sumInfo.Property(9) ' PID_REVNUMBER = 9, contains the package code.

 Set view = database.OpenView ("SELECT Value FROM Property WHERE Property='ProductVersion'")
    view.Execute
    Set result = view.Fetch
 
    ProductVersion = result.StringData(1)
end function

REM --- Code -------------------------------------------------------------------

new_version = ProductVersion()
installed_version = readFromRegistry ("HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{12345678-D8EF-4EE9-8DC4-FF5911256E0D}\DisplayVersion", "0.0.0" )
uninstall_user_result = MsgBox("About to install " + new_version + " instead of " + installed_version + ", continue?",3,"Please answer")


Select Case uninstall_user_result
 Case 6 ' Yes
  exitcode = 0
  
 Case Else
  exitcode = 1 
End Select

WScript.Quit exitcode  REM return results

Executing VBScripts from command line

http://commandwindows.com/scripts.htm

Hope it helps.