request_maker.py

import socket


class DNSRequestMaker:

    def __init__(self):
        self.port = 53

    def make_request(self, request, host):
        address = (host, self.port)
        with socket.socket(socket.AF_INET, socket.SOCK_DGRAM) as sock:
            sock.sendto(request, address)
            answer, address = sock.recvfrom(1024)
        return answer

    def form_dns_request(self, request):
        header = self.form_dns_header()
        body = self.form_dns_body(request)
        request_type = bytes([0, 1])
        request_class = bytes([0, 1])
        return header + body + request_type + request_class

    def form_dns_header(self):
        request_id = bytearray("id", "utf-8")
        flags = self.form_flags()
        requests_count = bytes([0, 1])
        answers_count = bytes([0, 0])
        add_count = bytes([0, 0, 0, 0])
        return request_id + flags + requests_count + answers_count + add_count

    def form_flags(self):
        qr = '0'
        opcode = '0000'
        aa = '0'
        tc = '0'
        rd = '0'
        ra = '0'
        z = '000'
        rcode = '0000'
        return int(f"{qr}{opcode}{aa}{tc}{rd}{ra}{z}{rcode}", 2)\
            .to_bytes(2, byteorder="big")

    @staticmethod
    def form_dns_body(request):
        domain_parts = request.split('.')
        bytes_request = bytes(0)
        for domain_part in domain_parts:
            bytes_request += bytes([len(domain_part)]) + bytearray(domain_part,
                                                                   "utf-8")
        bytes_request += bytes([0])
        return bytes_request