title: ICMP traceroute in Python
body: <p>I am trying to implement an ICMP based Traceroute in Python. </p>
  
  <p>I found a very helpful guide ( <a href="https://blogs.oracle.com/ksplice/entry/learning_by_doing_writing_your" rel="nofollow">https://blogs.oracle.com/ksplice/entry/learning_by_doing_writing_your</a> ) that has allowed me to create a UDP based Traceroute (code below) so just needs modification. I have tried changing the send socket to ICMP however I can't get anything to run without exceptions. </p>
  
  <p>Note - The below code works however this is a UDP traceroute (sends a UDP packet and receives an ICMP one) and I need my program to send an ICMP packet and receive an ICMP packet. Essentially the UDP socket needs to be changed for an ICMP one. </p>
  
  <p>I guess this isn't the most common thing to try and achieve and am having trouble researching on the net on how to do this. If anybody can provide some insight it would be REALLY appreciated :-)</p>
  
  <pre><code>#!/usr/bin/python
  
      import socket
  
      def main(dest_name):
          dest_addr = socket.gethostbyname(dest_name)
          port = 33434
          max_hops = 30
          icmp = socket.getprotobyname('icmp')
          udp = socket.getprotobyname('udp')
          ttl = 1
          while True:
              recv_socket = socket.socket(socket.AF_INET, socket.SOCK_RAW, icmp)
              send_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, udp)
              send_socket.setsockopt(socket.SOL_IP, socket.IP_TTL, ttl)
              recv_socket.bind(("", port))
              send_socket.sendto("", (dest_name, port))
              curr_addr = None
              curr_name = None
              try:
                  _, curr_addr = recv_socket.recvfrom(512)
                  curr_addr = curr_addr[0]
                  try:
                      curr_name = socket.gethostbyaddr(curr_addr)[0]
                  except socket.error:
                      curr_name = curr_addr
              except socket.error:
                  pass
              finally:
                  send_socket.close()
                  recv_socket.close()
  
              if curr_addr is not None:
                  curr_host = "%s (%s)" % (curr_name, curr_addr)
              else:
                  curr_host = "*"
              print "%d\t%s" % (ttl, curr_host)
  
              ttl += 1
              if curr_addr == dest_addr or ttl &amp;gt; max_hops:
                  break
  
      if __name__ == "__main__":
          main('google.com')
  </code></pre>