net/dns: windows DNS experiments

net/dns/dns_windows_test.go

@@ -0,0 +1,39 @@
+// Copyright (c) 2021 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 dns
+
+import (
+	"testing"
+
+	"golang.org/x/sys/windows"
+)
+
+func TestWindowsDNSQuery(t *testing.T) {
+	/*
+		DNS_TYPE_A    = 0x0001
+		DNS_TYPE_AAAA    = 0x001c
+		DNS_TYPE_SRV     = 0x0021
+		DNS_TYPE_TEXT    = 0x0010
+	*/
+	var options uint32 = 0
+	var qtype uint16 = windows.DNS_TYPE_AAAA
+	var qrs *windows.DNSRecord
+	st := windows.DnsQuery("google.com", qtype, options, nil, &qrs, nil)
+	t.Logf("status = %v", st)
+	if qrs != nil {
+		const (
+			DnsFreeFlat                = 0
+			DnsFreeRecordList          = 1
+			DnsFreeParsedMessageFields = 2
+		)
+		defer windows.DnsRecordListFree(qrs, DnsFreeRecordList)
+	}
+	t.Logf("qrs = %p", qrs)
+	for rec := qrs; rec != nil; rec = rec.Next {
+		t.Logf("rec: %+v", rec)
+		name := windows.UTF16PtrToString(rec.Name)
+		t.Logf("  name = %q", name)
+	}
+}