Implement COM server (timebox)

I copy/paste the comment from NXDRIVE-1156 just below, but the scope of this ticket is to have a working COM server. To validate, the given script Python must be able to connect.

—

Technical information here: The Component Object Model on MSDN.
There is a DLL source code in the wip-NXDRIVE-1156-windows-fs-decorator branch (taken from ownCloud and reduced/adapted for our needs). The revelant code is in tools/windows/icon_overlays.

Requirements

Download Visual Studio 2017 Community. Installation options: select Universal Windows Platform development with its subcomponent C++ Universal Windows Platform tools.

Build the DLL

Open OCShellExtensions.sln with Visual Studio 2017. Press F7 or use the Build menu entry.

Register the DLL

Open a Command Prompt in admin, go to dist/Debug/Win32 and type:

regsvr32 DriveOverlays_x86.dll

A message should tell you the registered status.

The Drive Add-Ons installer will also add more information in the registry, see tools/windows/setup-addons-common.iss for details.

I think both action needs to be done: the regsvr32 and Add-Ons Installation.

Communication

The DLL communicates with Drive via socket. It uses a named pipe \\.\pipe\ndrive-USERNAME instead of a local server.
This part is blurred in my mind: is it the DLL that should start the socket? Because the socket seems closed all the time.

This is a small Python script that will communicate with the socket (but this does not work as the server is not yet started):

import os
import time

import pywintypes
import win32file
import win32pipe


named_pipe = f"\\\\.\\pipe\\ndrive-{os.getenv('USERNAME')}"
print(named_pipe)

quit = False
while not quit:
    try:
        handle = win32file.CreateFile(
            named_pipe,
            win32file.GENERIC_READ | win32file.GENERIC_WRITE,
            0,
            None,
            win32file.OPEN_EXISTING,
            0,
            None,
        )

        res = win32pipe.SetNamedPipeHandleState(
            handle,
            win32pipe.PIPE_READMODE_MESSAGE,
            None,
            None,
        )

        data = win32file.ReadFile(res, 64 * 1024)
    except pywintypes.error as e:
        if e.args[0] == 2:
            print("no pipe, trying again in a sec")
            time.sleep(1)
        elif e.args[0] == 109:
            print("broken pipe, bye bye")
            quit = True
    else:
        print(data)

The script will undefinitely try to get something from the server. Easy for debugging and testing.

Ideas

In the registry, I saw a key like Root: HKCR; Subkey: "CLSID\\{{#RegistryKey}\LocalServer32"; ValueType: string; ValueData: "C:\Users\Windows7\Desktop\some.dll".
Perhaps this is required to launch the server, but as the DLL contains everything to manager the server, and I read somewhere that it should be used for testing only, this is not a good idea.

As I am writing this comment, I just found this post: Abusing the COM Registry Structure: CLSID, LocalServer32, & InprocServer32.
It may be very interesting to read