1. DNS请求报文头

[]byte{0x01, 0b100000000, 1, 0, 0, 0}

2. 查询的域名 QNAME

func parseDomain(domain string) []byte {
	var b = []byte{}
	for _, s := range strings.Split(domain, ".") {
		b = append(b, byte(len(s)))
		b = append(b, []byte(s)...)
	}
	b = append(b, byte(0x00))
	return b
}

3. 报文头尾部

[]byte{1, 1}