1. # - Install Python 2.7.x
  2. # - python -m pip install dnslib
  3. # - Copy current host file where your dns_proxy.py file is
  4. # - Change your host file to blank
  5. # - Cahnge your dns server to 127.0.0.1
  6. # - Run python dns_proxy.py
  7. # The blocked hosts will be added to hosts_blocked file
  9. from dnslib import *
  10. from dnslib import server
  12. # Customize the port and address of your local server to suit your needs (e.g. localhost -> 0.0.0.0)
  13. local_addr = 'localhost'
  14. local_port = 53
  16. # Customize the address and port of the external DNS server
  17. external_dns_server_addr = '8.8.8.8' # Google dns server
  18. external_dns_server_port = 53
  20. def loadHosts(file_name):
  21. blocked = {}
  22. for line in open(file_name):
  23. if not " " in line:
  24. continue
  25. _, domain = line.strip().split(" ", 1)
  26. blocked[domain] = True
  27. return blocked
  29. blocklist = loadHosts("hosts")
  30. print "Loaded blocklist:", len(blocklist), blocklist.keys()[0:30]
  31. blocked = loadHosts("hosts_blocked")
  32. print "Loaded blocked:", len(blocked), blocked.keys()[0:30]
  34. class SpecialResolver:
  35. def resolve(self, request, handler):
  36. d = request.reply()
  37. q = request.get_q()
  38. q_name = str(q.qname)
  39. name = q_name.strip(".")
  41. if name in blocklist:
  42. # Answers
  43. d.add_answer(*RR.fromZone("%s 136 A 0.0.0.0" % name))
  45. # Authoritative Name Servers
  46. d.add_auth(*RR.fromZone("pfghmj.com 128505 NS localhost"))
  47. d.add_auth(*RR.fromZone("pfghmj.com 128505 NS localhost"))
  48. print "! Blocked", name
  49. if name not in blocked:
  50. print "--- New Blocked", name
  51. open("hosts_blocked", "a").write("\n0.0.0.0 " + name)
  52. blocked[name] = True
  54. # Recursively query another DNS server for other domains
  55. else:
  56. a = DNSRecord.parse(DNSRecord.question(q_name).send(external_dns_server_addr, external_dns_server_port))
  57. for rr in a.rr:
  58. d.add_answer(rr)
  59. return d
  61. r = SpecialResolver()
  62. s = server.DNSServer(r, port=local_port, address=local_addr)
  63. s.start_thread()
  65. import time
  66. while True:
  67. time.sleep(1)

DNS proxy to filter hosts file