KX Packet Inspector (Guild Wars 2)

Disclaimer: This is a developer tool intended for educational and research purposes only. It is a powerful utility and should be used responsibly. As with all our tools, its use is governed by our Terms of Service and Acceptable Use Policy. Users are responsible for using this tool in compliance with all applicable terms of service.

Overview

KX Packet Inspector is a tool designed to intercept and display both outgoing (sent) and incoming (received) network packets used by the Guild Wars 2 client (Gw2-64.exe). It uses DirectX 11 hooking and function detouring (via MinHook) to capture packet data. Outgoing packets are captured before final processing/encryption, while incoming packets are captured and potentially decrypted (if using RC4) before being fully processed by the client. Captured data is presented in a real-time ImGui window overlay.

The primary goal is to facilitate learning about the game's network protocol and potentially identify new or undocumented packet structures for both client-to-server (CMSG) and server-to-client (SMSG) communication.

Features

• Real-time Bidirectional Packet Logging: Captures and displays sent (CMSG) and received (SMSG) packet information (timestamp, direction, header ID, size, raw hex data).
• Individual Message Capture (SMSG): Hooks the game's internal message dispatcher at multiple key locations to comprehensively capture individual, framed, plaintext Server-to-Client messages after decryption and decompression have been handled by the game itself.
• Packet Identification: Attempts to identify known CMSG and SMSG packet headers based on their 2-byte opcode. Handles unknown headers gracefully, displaying the raw ID.
• ImGui Interface: Provides a clean in-game overlay to view packets, filter them, and control capture.
• Flexible Filtering:
  • Filter by direction (Show All / Sent Only / Received Only).
  • Filter by header/type (Show All / Include Checked / Exclude Checked).
  • Checkboxes provided for known CMSG, known SMSG, and special internal types (Unknown Header, Empty, etc.).
• Clipboard Support: Copy individual log lines or the entire current log content to the clipboard.
• Controls: Pause/resume capture, clear the log.
• Hotkeys:
  • INSERT: Show/Hide the Inspector window.
  • DELETE: Unload the DLL and safely detach from the game.

Status & Compatibility

This tool targets specific internal functions identified via pattern scanning. Packet parsing logic relies on structure offsets and behaviors derived from reverse engineering specific game versions. See the documentation for details on current targets and assumptions.

• Potential Stability: Core hooking (DirectX, function interception via patterns) may remain functional across some game patches.
• Potential Breakage: Significant game updates that modify internal network code, encryption methods, or data structure layouts may break this tool. This could affect function patterns, structure offsets (GameStructs.h), buffer state interpretation, or internal message processing logic (PacketProcessor.cpp).
• Maintenance: We will try to keep the tool updated if major breakages occur. However, community contributions for identifying issues and providing updated offsets, patterns, or logic are highly encouraged!

Building

kx-packet-inspector is a C++ project designed to work on Windows using Visual Studio.

Prerequisites:

• Visual Studio: Ensure that you have Visual Studio installed (2022 or later recommended), with the Desktop development with C++ workload.
• Windows SDK: Usually included with the Visual Studio workload.

Build Instructions:

1. Clone the Repository:

   git clone https://github.com/Krixx1337/kx-packet-inspector.git
   cd kx-packet-inspector

2. Open the Project in Visual Studio: Open KXPacketInspector.sln.
3. Build: Select configuration (e.g., Release | x64) and build (Build > Build Solution or Ctrl+Shift+B).
4. Output: The compiled DLL (KXPacketInspector.dll) will be in the output directory (e.g., x64/Release).

Usage

You can either download a pre-compiled .dll from the project's Releases page or build it yourself.

1. Obtain the KXPacketInspector.dll file.
2. Use a DLL loading tool (e.g., Xenos, Process Hacker) to load the DLL into the running Gw2-64.exe process, preferably after the game is fully loaded (character select or in-game).
3. Press INSERT to toggle the inspector window visibility.
4. Use the UI controls for filtering, pausing, clearing, and copying.
5. Press DELETE to unload the tool cleanly.

TODO & Community Contributions

This project is open source, and community involvement is highly welcome! Here are some areas where help would be great:

• [X] Log Received Packets: (Implemented) - Tool now logs both sent and received packets.
• [ ] Identify More Packet Headers: The PacketHeaders.h file contains only a small subset of known packets. Researching, identifying, and adding more headers (especially SMSG) with their correct IDs and names would greatly improve the tool's utility.
• [ ] Improve Packet Parsing: Define structures for the payload of known packets (both CMSG and SMSG) to automatically parse and display their fields instead of just raw hex data. This is the core area for community contribution.
• [ ] Refine Packet Processing: Investigate potential compression or other encoding methods used by the game.
• [ ] Update Structure Offsets/Patterns: If game updates break the tool, help reverse engineer the new function patterns or structure offsets.
• [ ] Bug Fixes & Enhancements: Improve the UI, add new features (e.g., saving logs, search), fix bugs.

Feel free to fork the repository, make changes, and submit Pull Requests!

Credits

• Initial hooking/scanning concepts adapted from rafzi's Hacklib_gw2.
• Uses Dear ImGui.
• Uses MinHook.
• Uses SafetyHook.

Community & Contact

Have questions or want to discuss development?

• 💬 Discord: Connect with us and other users on the official KX Tools Discord Server.
• 🌐 Website: Explore our other Guild Wars 2 projects at kxtools.xyz.

License

This project is licensed under the MIT License.