IW4x: Client

IW4x is a community-driven project that aims to revitalize and enhance the Call of Duty: Modern Warfare 2 (2009) multiplayer experience by providing a stable platform with support for dedicated servers and modding.

A Steam installation of Modern Warfare 2 is required to run IW4x, copies from the Microsoft Store are not compatible.

IW4x is distributed through the IW4x Launcher.

Compiling from Source

Important

Clone the git repository instead of downloading the ZIP, as the latter will not work.

1. Clone the repository - git clone https://github.com/iw4x/iw4x-client.git
2. Run generate.bat to initialize and update submodules and generate the Visual Studio solution
3. Open/build the generated solution file build\iw4x.sln with Visual Studio

To use the iw4x.dll, you must have a valid Modern Warfare 2 installation with the IW4x Rawfiles installed.

Development Setup

Build to MW2 Directory

1. Right-click the IW4x solution in Visual Studio
2. Select Properties
3. Set the output directory to your MW2 install path

Setup Debugger

1. Right-click the IW4x solution in Visual Studio
2. Select Properties
3. Select Debugging
4. Set the Command value to the path of your iw4x.exe inside your MW2 game files

Tip:

• Switch to Windowed mode in-game, as breakpoints will lock the window.
• Pressing F5 will launch the game and attach the debugger.
• The default hotkey for stopping the debugger is Shift+F5.

Premake arguments

Argument	Description
--copy-to=PATH	Optional, copy the DLL to a custom folder after build, define the path here if wanted.
--copy-pdb	Copy debug information for binaries as well to the path given via --copy-to.
--disable-binary-check	Do not perform integrity checks on the exe.
--sentry-dsn=URL	Submit crash reports to this Sentry DSN. Crash reporting is compiled out when it is not given.

Command line arguments

Argument	Description
-entries	Print to the console a list of every asset as they are loaded from zonefiles.
-stdout	Redirect all logging output to the terminal iw4x is started from, or if there is none, creates a new terminal window to write log information in.
-console	Allow the game to display its own separate interactive console window.
-dedicated	Starts the game as a headless dedicated server.
-dump	Write info of loaded assets to the raw folder as they are being loaded.
-nointro	Skip game's cinematic intro.
-version	Print IW4x build info on startup.
-steam	Enable friends feature and other Steam integrations.
-unprotect-dvars	Allow the server to modify saved/archive dvars.
-zonebuilder	Start the interactive zonebuilder tool console instead of starting the game.
-original-str-parsing	(ZoneBuilder mode only) Parse .str files in the same manner as the CoD4 Mod Tools.
-disable-notifies	Disable "Anti-CFG" checks
-disable-mongoose	Disable Mongoose HTTP server
-disable-rate-limit-check	Disable RCon rate limit checks
-disable-mod-unloading	Disable automatic mod (fs_game) unloading when disconnecting
-sentryfull	Capture full process memory in crash reports rather than the stack and its surroundings.
-sentrystack	Capture only stack memory in crash reports.
-sentrydebug	Print the crash reporter's own diagnostics to the console.

Crash reporting

Crash reports are submitted to Sentry through the Sentry Native SDK, using its out-of-process native backend. Three binaries make up the client side of it:

Binary	Role
iw4x.dll	Holds the SDK, the scope and the in-process crash handler.
sentry-crash.exe	Started at launch and parked until a crash. Writes the minidump against the crashed game from the outside and uploads it, so a corrupted heap or an exhausted stack cannot take the report down with it.
sentry-wer.dll	Registered with Windows Error Reporting. Catches fail-fast exceptions, stack buffer overruns and heap corruption, none of which reach a top level exception filter.

All three are published with each release and must be installed side by side.

Enabling it in a development build

Crash reporting is compiled out unless a DSN is passed to premake, so it is off by default and release builds take the DSN from a repository secret. To point a local build at Sentry, copy the example configuration and fill in the DSN:

cp sentry.bash.example sentry.bash
sh generate-linux.sh release

Note that sentry.bash is ignored by git and is picked up automatically by generate-linux.sh, which passes the DSN on to premake and exports the rest of the file so sentry-cli can upload debug symbols from the same shell.

On Windows the same is done with a user script, which git ignores as well. Create user.bat next to generate.bat containing:

@echo off
call generate.bat --sentry-dsn=https://...

Disclaimer

This software has been created purely for the purposes of academic research. It is not intended to be used to attack other systems. Project maintainers are not responsible or liable for misuse of the software. Use responsibly.