Open Source - Revora/CnC-Online Client

C&C:Online is a community-made and -managed online server for Generals, Zero Hour, Tiberium Wars, Kane's Wrath, and Red Alert 3, allowing you to log in and continue playing online just like you could when GameSpy's servers were still online.

Description

This project provides a patch through DLL injection or DLL sideloading to restore online play features in games such as Red Alert 3 using the Revora/CnC-Online server. It serves as an alternative to the official CnC-Online launcher which use EasyHook for the patching process.

🐧 Running Linux ? This patch is compatible with Linux/Proton.

Note

This patch was mainly tested with Red Alert 3, which is the primary focus of this project, but it works just fine with the other games supported by Revora/CnC-Online.

Usage

A) DLL Sideloading (easy)

This patch DLL can act as a proxy to winmm.dll located in C:\Windows\System32\.

Rename opencnconline.dll to winmm.dll and copy it next to the game's executable (not the game's launcher).

Example:

• Red Alert 3:
  • Exec = RA3.exe ❌ -> \Data\ra3_1.12.game ✔️
  • DLL = \Data\winmm.dll
• C&C3 Kane's Wrath:
  • Exec = CNC3EP1.exe ❌ -> \RetailExe\1.2\cnc3ep1.dat ✔️
  • DLL = \RetailExe\1.2\winmm.dll
• C&C3 Tiberium Wars:
  • Exec = CNC3.exe ❌ -> \RetailExe\1.9\cnc3game.dat ✔️
  • DLL = \RetailExe\1.9\winmm.dll
• Zero Hour:
  • Exec = Generals.exe ❌ -> \game.dat ✔
  • DLL = \winmm.dll

🐧 Linux/Proton: Open up the game properties in Steam and add WINEDLLOVERRIDES="winmm=n,b" %command% to the launch options. Then launch the game as you would normally do.

B) DLL Injection (advanced)

This patch was originally designed to work with my RA3.exe re-implementation / alternative, but it can also be used with any DLL injection tool of your choice.

A quick google search will find you plenty on GitHub.
🐧 Linux: the classic combo createRemoteThread() + LoadLibrary() from Kernel32 works under Wine/Proton.

You need to inject the DLL into the game process and not the launcher.

Example:

• Red Alert 3:
  • Exec = RA3.exe ❌ -> \Data\ra3_1.12.game ✔️
  • Args = -config "%GAMEDIR%\RA3_english_1.12.SkuDef"
• C&C3 Kane's Wrath:
  • Exec = CNC3EP1.exe ❌ -> \RetailExe\1.2\cnc3ep1.dat ✔️
  • Args = -config "%GAMEDIR%\CNC3EP1_english_1.2.SkuDef"
• C&C3 Tiberium Wars:
  • Exec = CNC3.exe ❌ -> \RetailExe\1.9\cnc3game.dat ✔️
  • Args = -config "%GAMEDIR%\CNC3_english_1.9.SkuDef"
• Zero Hour:
  • Exec = Generals.exe ❌ -> \game.dat ✔️

How does it work ?

Upon injection into the game process, the patch DLL performs the following actions:

• Find and replace the original EA public key with the CnC-Online key (if any).
• Hook ws2_32 (winsock2) send() and gethostbyname() Win32 API calls to redirect them to the CnC Online GameSpy server emulation service.

Connected to C&C:Online

Why not use the official CnC-Online launcher ?

"Launchers inception" (Launcher that starts another Launcher) is despised by many but it remains a matter of personal preference. For me the core issue was that their launcher did not work with the Steam version nor with Linux/Proton when I tried it.

And I'm absolutely not a fan of registering their launcher as a debugger in the registry for specific executables (what they call "hook" mode in their launcher).

I aimed to restore the online features of Red Alert 3 without relying on their launcher and make the solution compatible with Linux/Proton.

Connected to C&C:Online under 🐧 Linux/Proton 9.0-2 (Fedora)

Reminder for Online Play

Registry

Please be advice that these games check the values in the registry: incorrect or missing value(s) may prompt an "offline" error when entering "Online play" in the menu even tho your network and the server are fine (not to be confused with actual network error).

NAT

These games use IPv4 only and are P2P meaning you most likely need port forwarding to play online. If you are playing with your mates consider using a VPN (hamachi, radmin, ...) even for online play as a work-around.

Red Alert 3 ports:

PORT	DESCRIPTION
TCP/3783	RA3 Voice Chat Port
TCP/4321	RA3 Mangler Servers
TCP/28900	RA3 Master Server List Request
TCP/29900	GP Connection Manager
TCP/29901	GP Search Manager
TCP/16000	Backend Server
UDP/6500	RA3 Query Port
UDP/6515	RA3 Dplay UDP
UDP/13139	RA3 Custom UDP Pings
UDP/27900	RA3 Master Server UDP Heartbeat
UDP/16000	Backend Server

Network interface

Being P2P these games generally have an option in their settings menu to choose which IP/Network adapter to use. Usually the default is fine and correct but sometimes it isn't.

Build

🆚 Visual Studio 2022

📦 Vendor dependencies:

• Microsoft Detours library

Solution: ./vc/opencnconline.sln
Output: ./build/output/${platform}/${config}