usbipd-win

USB/IP basically forwards USB over IP/Network, as the name implies. Forwarding or sharing sockets, or similar, is an absolute nightmare, so this enables a quick and easy operation.

The only downside is that the device won’t be available on Windows anymore. This is either the case while the device is attached, or even as long as it’s bound (see below for further explanation). This I can live with, as my whole development environment lives within WSL anyway.

Install

Attention

You need to perform the Windows installation in addition to the distro’s specific instructions.

Windows

First, you need to install the usbipd-win software on the Windows side. Some GUI tools automatically install this.

You can also run (from an elevated prompt)

winget install usbipd

Tip

Make sure to reopen any shell/terminal and check that uspipd.exe is available on your PATH.

Set up

Note

You might need to perform some or even all of the following steps using elevated rights.

GUI

The process can be greatly simplified, by installing downloading wsl-usb-manager on the Windows side.

Note

This GUI does not automatically install usbipd-win! Please download the installer from the release page and install it.

You can do everything you desire from within the GUI, even set up auto attachments, without a hassle.

CLI

First, list available devices using

usbipd.exe list

Take note of the BUSID of the desired (smart card) device.

Tip

You can also use the Hardware ID (VID:PID column) by using the -i flag instead of the -b one.

Then simply execute

usbipd.exe bind -b BUSID

Replace

• BUSID : the one you took note of earlier.

Note

It might be necessary to force this operation with the -f flag, in which case the device will be unavailable under Windows until you perform an unbind.

Now the only thing left to do is attaching the smart card to WSL

usbipd.exe attach -w -b BUSID

You can even have it auto-attached with

usbipd.exe attach -w -a -b BUSID

Note

The bind procedure is persistent between reboots. The attach procedure however isn’t, necessitating a reattachement.

This also means forcing the bind using -f makes it unavailable until you explicitly do an unbind, when attach on the contrary, reinstates control to Windows whenever the device is no longer connected to WSL.

Tip

You can easily check if this worked by observing the usbipd.exe command output, or by utilizing lsusb from the usbutils package.

FIDO2

Despite all this, some utilities, for example ssh-keygen, utilize a direct smart card access using, e.g., the /dev/hidraw devices the USB/IP setup produces.

For that to work, I had to set up a udev rule.