simple scapy dns resolver example

dns_qq.py

#!/usr/bin/env python3
from scapy.all import *

def parse_args():
    argc = len(sys.argv)
    if (argc <= 1 or argc > 3):
        print('Usage: %s: q_name resolver_ip')
        sys.exit(0)
    if (argc == 2):
        resolver='1.1.1.1'
    if (argc == 3):
        resolver=sys.argv[2]
    return (sys.argv[1], resolver)

def craft_query(_qname, _resolver_ip):
    Q=IP(dst=_resolver_ip)/UDP(dport=53)/DNS(rd=1,qd=DNSQR(qname=_qname))
    return Q
if __name__ == '__main__':
    qname, resolver = parse_args()
    print("--- Crafting     DNS query for %s to %s: " %(qname, resolver))
    Q = craft_query(qname, resolver)
    print("--- Transmiting  DNS query for %s to %s: " %(qname, resolver))
    R = sr1(Q, verbose=0)
    #ls(R)
    print("--- Results:     %s" %(R))
    sys.exit(0)