// Copyright (c) 2020 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. package resolver import ( "net" "os" "golang.org/x/sys/windows" ) func networkIsDown(err error) bool { if oe, ok := err.(*net.OpError); ok && oe.Op == "write" { if se, ok := oe.Err.(*os.SyscallError); ok { if se.Syscall == "wsasendto" && se.Err == windows.WSAENETUNREACH { return true } } } return false } func networkIsUnreachable(err error) bool { // TODO(bradfitz,josharian): something here? what is the // difference between down and unreachable? Add comments. return false }