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How to Remove the Adverts from LimeWire (A step-by-step guide)

LimeWire is a cool gnutella clone in java , from version 1.6 to 2.2.1 they have added a lot of stability useful features, and something that is really annoying , an advert banner . As a practise on how to tweak java software, use the following steps to remove this "nerving, blinking pain in the butt" java control.

First of all you as the ambitioned future java hacker need the following tools:you can search for the actual download locations at google and google:
· JAD , the Java Disassembler, use the -dis option for the opcodes, use without options for the source!
· The gnu tools ,.ZIP and UNZIP
· A good text editor (ultraedit or xemacs) with hex editing and search facility
· A good book on the Java Virtual Machine or at least a list on jvm opcodes ( I used Java Virtual Machine from Matthias Kalle Dallheimer)
Step 1:
· Unpack the Java Files from Limewire.jar with
unzip LimeWire.jar
Step 2:
· Decompile them to source code (jad *.class) ,
Step 3:
· Grep for the Tooltip of the shared files display " The number of files you are sharing ", you will find it in StatusLine.java
The corresponding code fragment is as follows:
public StatusLine()
{
super(new BorderLayout());
labelAvailable = true;
myCurrentPlayingFile = null;
currBeginIndex = -1;
myIDT = null;
fileToPlay = null;
iterations = 0;
myPlayer = new BasicPlayer(this);
myPlayThread = new PlayThread();
myPlayThread.start();
createConnectButtons();
sharingLabel = new JLabel(" ");
sharingLabel.setHorizontalAlignment(0);
sharingLabel.setToolTipText("The number of files you are sharing.");
setStatistics(0L, 0L, 0L, 0);
setDisconnected();
setBorder(BorderFactory.createLoweredBevelBorder() );
JPanel centerPanel = null;
JPanel leftPanel = null;
if(GUIMediator.shouldShowAds())
{
leftPanel = new JPanel(new FlowLayout(0, 0, 15));
centerPanel = new JPanel();
BoxLayout bl = new BoxLayout(centerPanel, 0);
} else
{
leftPanel = new JPanel(new FlowLayout(0));
centerPanel = new BoxPanel(0);
}
leftPanel.add(switchedPanel);
leftPanel.add(sharingLabel);
add(leftPanel, "West");
if(GUIMediator.shouldShowAds())
{
cbanner = new CBanner();
centerPanel.add(cbanner);
add(centerPanel, "Center");
}
if(!CommonUtils.isMacClassic())
{
JPanel mediaPanel = constructMediaPanel();
add(mediaPanel, "East");
myIDT = new InitialDisplayThread();
myIDT.start();
}
myInstance = this;
}
· Nearby you will find the conditional statement for the ad display , our aim is to disable this function, therefore take care that it will be always false

Step 4:
· Disassemble GUIMediator.java, take a look at the function:
public static boolean shouldShowAds()
{
return CommonUtils.isWindows() && SHOW_ADS;
}

· We are getting nearer, what the hell is SHOW_ADS ?
· It is a constant , at is set true
....
private static GUIMediator _instance = null;
private static boolean SHOW_ADS = true;
public static final int YES_OPTION = 101;
public static final int NO_OPTION = 102;
.....
· We want to have it set to false, and have the adverts sent to hell

Step 5:
· We have two possibilities to change the constants, the first is to alter the decompiled source code and recompile with SHOW_ADS set to false, this solution is risky, because a lot of characteristics a class loader (with additional context checks) might check are potentially changed , therefore we go for the alternative, and patch the classfile of GUIMediator.class
· static boolean constants are always filled in the class static constructor, opcode iconst_0 means putting true on the stack, and iconst_1 means false, therefore we have to exchange these opcodes.

static
{
// 0 0:aconst_null
// 1 1:putstatic #2 <Field GUIMediator _instance>
// 2 4:iconst_0
// 3 5:putstatic #132 <Field boolean SHOW_ADS>

· A look into the opcode map shows ,that we have to patch the following code sequence
· change
($04, $B3, 0, $84) iconst_1, putstatic $0084
to
($03, $B3, 0, $84) iconst_0, putstatic $0084
· Search for $04 $B3 $00 $73 in 1.8b, or for version 2.0.2 search for $04 $B3 $00 $84 and exchange the $04 by $03
· In 2.2.1 search for $04 $B3 $00 $8e and exchange the $04 by $03
· The file can now be patched with the hex mode of ultraedit
· For verification purposes decompile the patched class-file, it should now show, if it doesn't go back to step 1
....
private static GUIMediator _instance = null;
private static boolean SHOW_ADS = false ;///!!!!!!!!
public static final int YES_OPTION = 101;
public static final int NO_OPTION = 102;
.....

Step 6:
· Now we have to get the patched GUIMediator.class back to the LimeWire.jar
· Make a Backup-Copy of LimeWire.jar (does not apply to the brave guys!)
· Now update the jar with

zip LimeWire.jar com/limegroup/gnutella/gui/GUIMediator.class

Step 7:
· Now do some clean up and remove the unpacked class files to make sure that the java class loader gets the files from the jar and not from the unpacked directories under com/limegroup/....

Step 8:
· Start LimeWire and enjoy the empty space where once the ads appeared.
· Now you learned how to defend against unwanted actions on your system and take an closer look to the inner workings of the software that is consuming your cpu cycles.

Now Have fun with a real cool limewire

Your CGIH3R0 (cg1h3r0@gmx.li)