ipv6 list open-resolver dns scan *multi threaded*

#!/usr/bin/env python
import os
import sys
import dns.resolver
import Queue
import time
import threading

# Various settings
numthreads = 150
resultList = []
wq = Queue.Queue()

# Thread Launcher
def launchThreads(argsfile,numthreads):
    global wq
    # Enqueing Stuff
    with open(args.file, "r") as ipsfile:
      for ip in ipsfile:
        wq.put(ip)
    # Spawning Threads
    for i in range(numthreads):
        t = threading.Thread(target=tRun)
        t.start()        
    while threading.active_count() > 1:
        time.sleep(0.1)

# Thread            
def tRun():
    global wq
    global resultList
    while not wq.empty():
        ip = wq.get()
        resolver = dns.resolver.Resolver()
        resolver.lifetime = args.timeout
        target = args.url or 'google.com'
        resolver.nameservers = [ip]
    # If we get an answer, it's open
        try:
          answers = resolver.query(target, 'A')
          print '%s,open' % (ip.rstrip())
          resultList.append('%s' % (ip))
        # If no response do nothing
        except (dns.resolver.NoAnswer, dns.resolver.NoNameservers), ex:
          print '%s,closed' % (ip.rstrip())
        # If timeout do nothing
        except dns.resolver.Timeout, ex:
          print '%s,unresponsive' % (ip.rstrip())
          pass
        # If something else went sideways do nothing
        except:
          print '%s,unresponsive' % (ip.rstrip())
          pass        

if __name__ == '__main__':
    # Process command line options
    import argparse
    parser = argparse.ArgumentParser(description = 'Scan IPv6 file for DNS resolvers')
    parser.add_argument('-t', '--timeout', type = float, default = 1.0, help = 'timeout for each request')
    parser.add_argument('-u', '--url', default = 'finn.hype', help = 'hostname to use as target')
    parser.add_argument('file', type = str, help = 'list of ip addresses')
    args = parser.parse_args()

    # Run scans, die properly on CTRL-C
    try: 
      launchThreads(args.file,numthreads)
        
      # Print results      
      print 'Final result list'
      for x in resultList:
         print x
      print "Number of open resolvers: %s" %(len(resultList))
      
    except KeyboardInterrupt, ex:
        pass