import socket
    from struct import *
    import binascii


    class Packet:
        def __init__(self, dest_ip, dest_port):
            # https://docs.python.org/3.7/library/struct.html#format-characters
            # all values need to be at least one byte long (-> we need to add up some values)

            ############
            # IP segment
            self.version = 0x4
            self.ihl = 0x5
            self.type_of_service = 0x0
            self.total_length = 0x28
            self.identification = 0xabcd
            self.flags = 0x0
            self.fragment_offset = 0x0
            self.ttl = 0x40
            self.protocol = 0x6
            self.header_checksum = 0x0
            self.src_ip = socket.gethostbyname(socket.getfqdn())
            self.dest_ip = dest_ip
            self.src_addr = socket.inet_aton(self.src_ip)
            self.dest_addr = socket.inet_aton(dest_ip)
            self.v_ihl = (self.version << 4) + self.ihl
            self.f_fo = (self.flags << 13) + self.fragment_offset

            #############
            # TCP segment
            self.src_port = 0x3039
            self.dest_port = dest_port
            self.seq_no = 0x0
            self.ack_no = 0x0
            self.data_offset = 0x5
            self.reserved = 0x0
            self.ns, self.cwr, self.ece, self.urg, self.ack, self.psh, self.rst, self.syn, self.fin = 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1, 0x0
            self.window_size = 0x7110
            self.checksum = 0x0
            self.urg_pointer = 0x0
            self.data_offset_res_flags = (self.data_offset << 12) + (self.reserved << 9) + (self.ns << 8) + (
                        self.cwr << 7) + (self.ece << 6) + (self.urg << 5) + (self.ack << 4) + (self.psh << 3) + (
                                                     self.rst << 2) + (self.syn << 1) + self.fin

            ########
            # packet
            self.tcp_header = b""
            self.ip_header = b""
            self.packet = b""

        def calc_checksum(self, msg):
            s = 0
            for i in range(0, len(msg), 2):
                w = (msg[i] << 8) + msg[i + 1]
                s = s + w
            # s = 0x119cc
            s = (s >> 16) + (s & 0xffff)
            # s = 0x19cd
            s = ~s & 0xffff
            # s = 0xe632
            return s

        def generate_tmp_ip_header(self):
            tmp_ip_header = pack("!BBHHHBBH4s4s", self.v_ihl, self.type_of_service, self.total_length,
                self.identification, self.f_fo,
                self.ttl, self.protocol, self.header_checksum,
                self.src_addr,
                self.dest_addr)
            return tmp_ip_header

        def generate_tmp_tcp_header(self):
            tmp_tcp_header = pack("!HHLLHHHH", self.src_port, self.dest_port,
                self.seq_no,
                self.ack_no,
                self.data_offset_res_flags, self.window_size,
                self.checksum, self.urg_pointer)
            return tmp_tcp_header

        def generate_packet(self):
            # IP header + checksum
            final_ip_header = pack("!BBHHHBBH4s4s", self.v_ihl, self.type_of_service, self.total_length,
                self.identification, self.f_fo,
                self.ttl, self.protocol, self.calc_checksum(self.generate_tmp_ip_header()),
                self.src_addr,
                self.dest_addr)
            # TCP header + checksum
            tmp_tcp_header = self.generate_tmp_tcp_header()
            pseudo_header = pack("!4s4sBBH", self.src_addr, self.dest_addr, self.checksum, self.protocol,
                len(tmp_tcp_header))
            psh = pseudo_header + tmp_tcp_header
            final_tcp_header = pack("!HHLLHHHH", self.src_port, self.dest_port,
                self.seq_no,
                self.ack_no,
                self.data_offset_res_flags, self.window_size,
                self.calc_checksum(psh), self.urg_pointer)

            self.ip_header = final_ip_header
            self.tcp_header = final_tcp_header
            self.packet = final_ip_header + final_tcp_header

        def send_packet(self):
            s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_TCP)
            s.setsockopt(socket.IPPROTO_IP, socket.IP_HDRINCL, 1)
            s.sendto(self.packet, (self.dest_ip, 1))
            data = s.recv(1024)
            s.close()
            return data

    if __name__ == '__main__':
        p = Packet("8.8.8.8", 80)
        p.generate_packet()
        result = p.send_packet()