[DRAFT] Implementing memory patches

[KillStr3aK]

util related things and CMemPatch is borrowed from cs2fixes

this is a pretty wanky implementation, I think we should drop the gameconfig dependency from CMemPatch as thats why I made it like how it is currently.

assume we have the following gamedata:

{
    "ServerMovementUnlock": {
      "signatures": {
        "library": "server",
        "windows": "\\x76\\x2A\\xF2\\x0F\\x10\\x57\\x2A\\xF3\\x0F\\x10\\x2A\\x2A\\x0F\\x28\\xCA\\xF3\\x0F\\x59\\xC0",
        "linux": "\\x0F\\x87\\x2A\\x2A\\x2A\\x2A\\x49\\x8B\\x7C\\x24\\x2A\\xE8\\x2A\\x2A\\x2A\\x2A\\x66\\x0F\\xEF\\xED\\x66\\x0F\\xD6\\x85\\x2A\\x2A\\x2A\\x2A"
      },

      // we are still inside 'ServerMovementUnlock' so the patch would be for the signature above.
      "patches": {
        "windows": "\\xEB",
        "linux": "\\x90\\x90\\x90\\x90\\x90\\x90"
      }
    }
}

// this is a local build so no logger instance as I have not installed transitive packages
public class SamplePlugin : BasePlugin
{
    public override string ModuleName => "Sample Plugin";

    public override string ModuleVersion => "1.0.0";

    private MemoryPatch patch = new MemoryPatch("ServerMovementUnlock", "ServerMovementUnlock");

    public override void Load(bool hotReload)
    {
        if (patch.PerformPatch())
        {
            Console.WriteLine("Performed patch {0} ({1})", patch.Name, patch.Signature);
        }
        else
        {
            Console.WriteLine("Unable to perform patch {0} ({1})", patch.Name, patch.Signature);
        }
    }

    public override void Unload(bool hotReload)
    {
        patch.UndoPatch();
    }
}

hotreloading the plugin will undo the patch, then perform it again:

also patches performed using the wrapper method is automatically reverted on unload:

public class SamplePlugin : BasePlugin
{
    public override string ModuleName => "Sample Plugin";

    public override string ModuleVersion => "1.0.0";

    public override void Load(bool hotReload)
    {
        CreateMemoryPatch("ServerMovementUnlock", "ServerMovementUnlock");
    }
}

Caution

Plugins that create their patches using the wrapper classes only and call PerformPatch are responsible for reverting the patch on unload. Creating patches with CreateMemoryPatch will be automatically reverted.

[KillStr3aK]

This will require change or rehaul in the future for sure, but its something we can use.
Since the core does not require any patch I've disabled auto performing them on load to give full control to the plugins, this can be changed later on if we'd need any patch to be performed internally

[KillStr3aK]

This will be moved to managed code as we can have memory patches in managed code, I'll create a new pr later on

[Oylneechan]

I know this is already closed, but FYI I did test on my own server. it seem like the signature and patches can't be in other gamedata json file, except the main gamedata.json file

[KillStr3aK]

this will be recreated in managed