test fixup

client/dns.go

@@ -81,3 +81,46 @@ func DoDNSChecked(in string, f DNSCheckFunc) (connectTo string, host string, por
 	connectTo = outIP.String() + ":" + port
 	return
 }
+
+// DoDnsSimple resolves a DNS name to an IP address
+// It should resolve a minecraft compatible address into something net.Dial
+// It does not check the address
+func DoDnsSimple(in string) (out string, err error) {
+	host, port, err := net.SplitHostPort(in)
+	if err != nil {
+		var addrErr *net.AddrError
+		if errors.As(err, &addrErr) && addrErr.Err == "missing port in address" {
+			err = nil
+			host = in
+			port = "25565"
+		} else {
+			return
+		}
+	}
+	porti, err := strconv.Atoi(port)
+	if err != nil {
+		return
+	}
+	portN := uint16(porti)
+	_, err = net.ResolveIPAddr("ip", host)
+	if err != nil {
+		return
+	}
+	out = in
+	if portN != 25565 {
+		return
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second) // otherwise this takes 10+ seconds
+	defer cancel()
+
+	r := &net.Resolver{}
+
+	_, srvs, _ := r.LookupSRV(ctx, "minecraft", "tcp", host)
+	if len(srvs) == 0 {
+		return
+	}
+	host = strings.TrimSuffix(srvs[0].Target, ".")
+	portN = srvs[0].Port
+	out = host + ":" + strconv.Itoa(int(portN))
+	return
+}