mcast_traffic.py

#!/usr/bin/python

import time,sys,os,subprocess
import re
import socket
import argparse
import warnings

# use argparse to take the user input, can fill in default values here if the user wishes
warnings.filterwarnings("ignore")
parser = argparse.ArgumentParser()
parser.add_argument('--interface', required=True,
                    default='', help='Interface to send traffic out of')
parser.add_argument('--mcast_group', required=True,
                    default=[], help='Multicast group to send traffic to')
parser.add_argument('--number', required=False,
                    default='100', help='Number of packets per second to send.')
parser.add_argument('--size', required=False,
                    default='500', help='Size of packets in bytes')
parser.add_argument('--ttl', required=False,
                    default='64', help='TTL of the packets to send')
parser.add_argument('--incorrect_mac', required=False, action='store_true',
                    help='Option to set an incorrect destination MAC addresss')


args = parser.parse_args()
interface = args.interface
mcast_group = args.mcast_group
number = args.number
size = args.size
ttl = args.ttl
incorrect_mac = args.incorrect_mac

output = subprocess.Popen(['ifconfig', interface], stdout = subprocess.PIPE, stderr=subprocess.STDOUT)
stdout,stderr = output.communicate()
ether_pos = stdout.find("ether")
ip_pos = stdout.find("inet")
netmask_pos = stdout.find("netmask")
src_mac = stdout[ether_pos+6:ether_pos+23]
src_ip = stdout[ip_pos+5:netmask_pos-2]


def convert_multicast_ip_to_mac(ip_address, incorrect_mac):
    """Convert the Multicast IP to it's equivalent Multicast MAC.
    Source info: https://technet.microsoft.com/en-us/library/cc957928.aspx
    """
    # Convert the IP String to a bit sequence string
    try:
        ip_binary = socket.inet_pton(socket.AF_INET, ip_address)
        ip_bit_string = ''.join(['{0:08b}'.format(ord(x)) for x in ip_binary])
    except socket.error:
        raise RuntimeError('Invalid IP Address to convert.')

    # The low order 23 bits of the IP multicast address are mapped directly to the low order
    # 23 bits in the MAC-layer multicast address
    lower_order_23 = ip_bit_string[-23:]
    if incorrect_mac:
      if lower_order_23[0] == '1':
        new_lower_order_23 = '0' + lower_order_23[1:]
      elif lower_order_23[0] == '0':
        new_lower_order_23 = '1' + lower_order_23[1:]
      lower_order_23 = new_lower_order_23
          
    # The high order 25 bits of the 48-bit MAC address are fixed
    high_order_25 = '0000000100000000010111100'

    mac_bit_string = high_order_25 + lower_order_23

    # Convert the bit string to the Typical MAC Address String
    final_string = '{0:012X}'.format(int(mac_bit_string, 2))
    mac_string = ':'.join(s.encode('hex') for s in final_string.decode('hex'))
    return mac_string.upper()



mcast_mac = convert_multicast_ip_to_mac(mcast_group, incorrect_mac)

while True:
   try:
      os.system("sudo ethxmit -S " + src_mac + " -D " + mcast_mac + " --ip-src=" + src_ip + " --ip-dst=" + mcast_group + " -n " + number + " -s " + size + " --ttl " + ttl + " " + interface)
      time.sleep(1)
   except KeyboardInterrupt:
      raise