Add usbip module for usb support in WSL

flake.nix

@@ -19,7 +19,7 @@
         imports = [
           ./modules
 
-          ({ ... }: {
+          (_: {
             wsl.version.rev = mkIf (self ? rev) self.rev;
           })
         ];

modules/default.nix

@@ -5,6 +5,7 @@
     ./interop.nix
     ./recovery.nix
     ./systemd
+    ./usbip.nix
     ./version.nix
     ./welcome.nix
     ./wsl-conf.nix

modules/usbip.nix

@@ -0,0 +1,51 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  usbipd-win-auto-attach = pkgs.fetchurl {
+    url = "https://raw.githubusercontent.com/dorssel/usbipd-win/v3.1.0/Usbipd/wsl-scripts/auto-attach.sh";
+    hash = "sha256-KJ0tEuY+hDJbBQtJj8nSNk17FHqdpDWTpy9/DLqUFaM=";
+  };
+
+  cfg = config.wsl.usbip;
+in
+{
+  options.wsl.usbip = with types; {
+    enable = mkEnableOption "USB/IP integration";
+    autoAttach = mkOption {
+      type = listOf str;
+      default = [ ];
+      example = [ "4-1" ];
+      description = "Auto attach devices with provided Bus IDs.";
+    };
+  };
+
+  config = mkIf (config.wsl.enable && cfg.enable) {
+    environment.systemPackages = [
+      pkgs.linuxPackages.usbip
+    ];
+
+    services.udev.enable = true;
+
+    systemd = {
+      services."usbip-auto-attach@" = {
+        description = "Auto attach device having busid %i with usbip";
+        after = [ "network.target" ];
+
+        scriptArgs = "%i";
+        path = [ pkgs.linuxPackages.usbip ];
+
+        script = ''
+          busid="$1"
+          ip="$(grep nameserver /etc/resolv.conf | cut -d' ' -f2)"
+
+          echo "Starting auto attach for busid $busid on $ip."
+          source ${usbipd-win-auto-attach} "$ip" "$busid"
+        '';
+      };
+
+      targets.multi-user.wants = map (busid: "usbip-auto-attach@${busid}.service") cfg.autoAttach;
+    };
+  };
+}