#!/usr/bin/python

import sys, os
import socket, binascii

if len(sys.argv) < 3:
   print "Usage: udp.py <group> <port> <listen address>"
   exit(0)
mcast_grp = sys.argv[1]
mcast_port = int(sys.argv[2])
listen_addr = len(sys.argv) == 4 and sys.argv[3] or '0.0.0.0'

sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_TTL, 32)
sock.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_LOOP, 1)
sock.bind((mcast_grp, mcast_port))

host = listen_addr
sock.setsockopt(socket.SOL_IP, socket.IP_MULTICAST_IF, socket.inet_aton(host))
sock.setsockopt(socket.SOL_IP, socket.IP_ADD_MEMBERSHIP, socket.inet_aton(mcast_grp) + socket.inet_aton(host))

while 1:
   try:
      data, addr = sock.recvfrom(1024)
   except socket.error, e:
      print "error", e
   hexdata = binascii.hexlify(data)
   print 'Data = %s' % hexdata