Demo/dns/asgethost.py

   1 import sys
   2 import dnslib
   3 import dnstype
   4 import dnsopcode
   5 import dnsclass
   6 import socket
   7 import select
   8
   9 def main():
  10     server = 'cnri.reston.va.us'        # How?
  11     port = 53
  12     opcode = dnsopcode.QUERY
  13     rd = 0
  14     qtype = dnstype.MX
  15     qname = sys.argv[1:] and sys.argv[1] or 'www.python.org'
  16     m = dnslib.Mpacker()
  17     m.addHeader(0,
  18                 0, opcode, 0, 0, rd, 0, 0, 0,
  19                 1, 0, 0, 0)
  20     m.addQuestion(qname, qtype, dnsclass.IN)
  21     request = m.getbuf()
  22     s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
  23     s.connect((server, port))
  24     s.send(request)
  25     while 1:
  26         r, w, x = [s], [], []
  27         r, w, x = select.select(r, w, x, 0.333)
  28         print r, w, x
  29         if r:
  30             reply = s.recv(1024)
  31             u = dnslib.Munpacker(reply)
  32             dnslib.dumpM(u)
  33             break
  34
  35 main()