pyminifakedns/pyminifakedns.py

   1 #!/usr/bin/python2
   2
   3 import socket
   4
   5 class DNSQuery:
   6   def __init__(self, data):
   7     self.data=data
   8     self.dominio=''
   9
  10     tipo = (ord(data[2]) >> 3) & 15
  11     if tipo == 0:
  12       ini=12
  13       lon=ord(data[ini])
  14       while lon != 0:
  15         self.dominio+=data[ini+1:ini+lon+1]+'.'
  16         ini+=lon+1
  17         lon=ord(data[ini])
  18
  19   def respuesta(self, ip):
  20     packet=''
  21     if self.dominio:
  22       packet+=self.data[:2] + "\x81\x80"
  23       packet+=self.data[4:6] + self.data[4:6] + '\x00\x00\x00\x00'
  24       packet+=self.data[12:]
  25       packet+='\xc0\x0c'
  26       packet+='\x00\x01\x00\x01\x00\x00\x00\x3c\x00\x04'
  27       packet+=str.join('',map(lambda x: chr(int(x)), ip.split('.')))
  28     return packet
  29
  30 if __name__ == '__main__':
  31   ip='127.0.0.1'
  32   print 'pyminifakeDNS:: dom.query. 60 IN A %s' % ip
  33
  34   udps = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
  35   udps.bind(('',53))
  36
  37   try:
  38     while 1:
  39       data, addr = udps.recvfrom(1024)
  40       p=DNSQuery(data)
  41       udps.sendto(p.respuesta(ip), addr)
  42       print 'Response: %s -> %s' % (p.dominio, ip)
  43   except KeyboardInterrupt:
  44     print 'Finalizing ...'
  45     udps.close()