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I have a serial device that I'm bridging over the network using socat from a linux box to WSL running on a windows box. On the WSL side, is it possible to make the virtual serial port created by socat visible to an application running on Windows outside of WSL?

I have a solution working using HW Virtual Serial Port, but I was curious if there was a way to do this purely from WSL.

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1 Answers1

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These are not direct solutions, but I hope that they will be helpful.

There is no answer, but there was a similar question.
Issue passing valid command-line arguments for socat

After that, it seems that it was supported by Build 17107 from Insider Build 17063/17093.
AF_UNIX comes to Windows

Unsupported\unavailable:
Summarizing from the above, the following Linux unix socket features are either currently unavailable or unsupported in the Windows unix socket implementation.

  • AF_UNIX datagram (SOCK_DGRAM) or sequence packet (SOCK_SEQPACKET) socket type.
  • Ancillary data: Linux's unix socket implementation supports passing ancillary data such as passing file descriptors (SCM_RIGHTS) or credentials (‘SCM_CREDENTIALS`) over the socket. There is no support for ancillary data in the Windows unix socket implementation.
  • Autobind feature (see the section on ‘sockaddr_un’ for details).
  • socketpair: socketpair socket API is not supported in Winsock 2.0.

Windows/WSL Interop with AF_UNIX

Requirements & Limitations:

  1. A WSL Unix socket can only communicate with a Win32 Unix socket OR with a WSL Unix socket, but not both. For instance, a WSL Unix socket server can only accept connections from either WSL Unix socket(s) OR Win32 Unix socket(s). So, how is it determined which one is it? It’s based on the path the socket is bound to or connecting to, as specified in the bind or connect syscall. If the Unix socket path is a DrvFS path (i.e your system volumes mounted within WSL, ex: /mnt/c, /mnt/d etc.) then it can only communicate to a Windows Unix socket. If the path is a LxFS path (i.e Linux mounted volume within WSL, ex: /home, /var, /usr etc.) then it can only communicate with WSL Unix sockets.
  2. For a WSL Unix socket to establish connection with Windows Unix sockets, the first operation after the socket is created should be either a bind or connect. Any other operation on the socket will render it an exclusive WSL Unix socket that can only communicate with other WSL Unix sockets.
  3. As Windows Unix socket implementation does not currently support passing ancillary data such as SCM_RIGHTS etc., the ancillary data will also not be supported for Win32<->WSL interop over Unix sockets.

socat not working complaining about tsetaddr #2552 Closed

This may be the HW Virtual Serial Port you say.
COM Port Access in WSL #1929 Closed

There seems to be various modifications of socket relationship after that.
Release Notes for Windows Subsystem for Linux

Even other programs that use socat seem to work, but some seem to be unstable.
WSLから pageant を利用する
benpye/wsl-ssh-pageant

jstarks/npiperelay

Use an ssh-agent in WSL with your ssh setup from windows 10
How to use GPG with YubiKey (bonus: WSL)

kunif
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