DHCP query script not work.

Thu Jun 19 08:56:57 EDT 2014

Dear all
i got code recipes from here. and i want to run it on win 7. 
http://code.activestate.com/recipes/577649-dhcp-query/
i have do some modify and use print to check how it is work, but i am stucked now. 
hope someone can help me. thanks a lot.
i meet this error:
Traceback (most recent call last):
 File "D:/Workspace/TestExcel/Test/test_DHCP.py", line 138, in <module>
 offer = DHCPOffer(data, discoverPacket.transactionID)
 File "D:/Workspace/TestExcel/Test/test_DHCP.py", line 82, in __init__
 self.unpack()
 File "D:/Workspace/TestExcel/Test/test_DHCP.py", line 95, in unpack
 dnsNB = int(data[268] / 4)
TypeError: unsupported operand type(s) for /: 'str' and 'int'
########################################
__author__ = 'Administrator'
'''
Created on Mar 27, 2011
@author: hassane
'''
import socket
import struct
from uuid import getnode as get_mac
from random import randint
def getMacInBytes():
 print get_mac()
 mac = str(hex(get_mac()))
 print mac
 mac = mac[2:]
 mac = mac[:-1] # i edited
 print mac, len(mac)
 while len(mac) < 12:
 mac = '0' + mac
 print mac
 macb = b''
 for i in range(0, 12, 2):
 print mac[i:i + 2]
 m = int(mac[i:i + 2], 16)
 #print m
 macb += struct.pack('!B', m)
 print repr(macb), struct.calcsize('!B'),"++"
 print macb,"=="
 return macb
class DHCPDiscover:
 def __init__(self):
 self.transactionID = b''
 for i in range(4):
 t = randint(0, 255)
 self.transactionID += struct.pack('!B', t)
 print self.transactionID, "=="
 def buildPacket(self):
 macb = getMacInBytes()
 print repr(macb)
 packet = b''
 packet += b'\x01' # Message type: Boot Request (1)
 packet += b'\x01' # Hardware type: Ethernet
 packet += b'\x06' # Hardware address length: 6
 packet += b'\x00' # Hops: 0
 packet += self.transactionID # Transaction ID
 packet += b'\x00\x00' # Seconds elapsed: 0
 packet += b'\x80\x00' # Bootp flags: 0x8000 (Broadcast) + reserved flags
 packet += b'\x00\x00\x00\x00' # Client IP address: 0.0.0.0
 packet += b'\x00\x00\x00\x00' # Your (client) IP address: 0.0.0.0
 packet += b'\x00\x00\x00\x00' # Next server IP address: 0.0.0.0
 packet += b'\x00\x00\x00\x00' # Relay agent IP address: 0.0.0.0
 # packet += b'\x00\x26\x9e\x04\x1e\x9b' #Client MAC address: 00:26:9e:04:1e:9b
 packet += macb
 packet += b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00' #Client hardware address padding: 00000000000000000000
 packet += b'\x00' * 67 #Server host name not given
 packet += b'\x00' * 125 #Boot file name not given
 packet += b'\x63\x82\x53\x63' #Magic cookie: DHCP
 packet += b'\x35\x01\x01' #Option: (t=53,l=1) DHCP Message Type = DHCP Discover
 #packet += b'\x3d\x06\x00\x26\x9e\x04\x1e\x9b' #Option: (t=61,l=6) Client identifier
 packet += b'\x3d\x06' + macb
 packet += b'\x37\x03\x03\x01\x06' #Option: (t=55,l=3) Parameter Request List
 packet += b'\xff' #End Option
 return packet
class DHCPOffer:
 def __init__(self, data, transID):
 self.data = data
 self.transID = transID
 self.offerIP = ''
 self.nextServerIP = ''
 self.DHCPServerIdentifier = ''
 self.leaseTime = ''
 self.router = ''
 self.subnetMask = ''
 self.DNS = []
 self.unpack()
 def unpack(self):
 if self.data[4:8] == self.transID:
 self.offerIP = '.'.join(map(lambda x: str(x), data[16:20]))
 self.nextServerIP = '.'.join(map(lambda x: str(x), data[20:24])) # c'est une option
 self.DHCPServerIdentifier = '.'.join(map(lambda x: str(x), data[245:249]))
 self.leaseTime = str(struct.unpack('!L', data[251:255])[0])
 self.router = '.'.join(map(lambda x: str(x), data[257:261]))
 self.subnetMask = '.'.join(map(lambda x: str(x), data[263:267]))
 #print self.router, self.subnetMask, self.leaseTime, self.DHCPServerIdentifier, repr(self.offerIP)
 print repr(data)
 print repr(data[268])
 dnsNB = int(data[268] / 4)
 for i in range(0, 4 * dnsNB, 4):
 self.DNS.append('.'.join(map(lambda x: str(x), data[269 + i:269 + i + 4])))
 def printOffer(self):
 key = ['DHCP Server', 'Offered IP address', 'subnet mask', 'lease time (s)', 'default gateway']
 val = [self.DHCPServerIdentifier, self.offerIP, self.subnetMask, self.leaseTime, self.router]
 for i in range(4):
 print('{0:20s} : {1:15s}'.format(key[i], val[i]))
 print('{0:20s}'.format('DNS Servers') + ' : ', ) #end='' here also have error.
 if self.DNS:
 print('{0:15s}'.format(self.DNS[0]))
 if len(self.DNS) > 1:
 for i in range(1, len(self.DNS)):
 print('{0:22s} {1:15s}'.format(' ', self.DNS[i]))
if __name__ == '__main__':
 # defining the socket
 dhcps = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) #internet, UDP
 dhcps.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1) #broadcast
 try:
 dhcps.bind(('', 68)) #we want to send from port 68
 except Exception as e:
 print('port 68 in use...')
 dhcps.close()
 input('press any key to quit...')
 exit()
 #buiding and sending the DHCPDiscover packet
 discoverPacket = DHCPDiscover()
 dhcps.sendto(discoverPacket.buildPacket(), ('<broadcast>', 67))
 print('DHCP Discover sent waiting for reply...\n')
 #receiving DHCPOffer packet
 dhcps.settimeout(3)
 try:
 while True:
 data = dhcps.recv(1024)
 print "here",repr(discoverPacket.transactionID), ">>>", len(data)
 offer = DHCPOffer(data, discoverPacket.transactionID)
 if offer.offerIP:
 offer.printOffer()
 break
 except socket.timeout as e:
 print(e)
 dhcps.close() #we close the socket
 input('press any key to quit...')
 exit()