all: use named pipes on windows

Signed-off-by: Maisem Ali <maisem@tailscale.com>

ipn/ipnauth/ipnauth_notwindows.go

@@ -0,0 +1,24 @@
+// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !windows
+
+package ipnauth
+
+import (
+	"net"
+
+	"inet.af/peercred"
+	"tailscale.com/types/logger"
+)
+
+// GetConnIdentity extracts the identity information from the connection
+// based on the user who owns the other end of the connection.
+// and couldn't. The returned connIdentity has NotWindows set to true.
+func GetConnIdentity(_ logger.Logf, c net.Conn) (ci *ConnIdentity, err error) {
+	ci = &ConnIdentity{conn: c, notWindows: true}
+	_, ci.isUnixSock = c.(*net.UnixConn)
+	ci.creds, _ = peercred.Get(c)
+	return ci, nil
+}