PathFinder-Server.py

#******************************************************************************
# MAC path finder - Server part
#		equivalent to traceroute but based on MAC address
# Version: 1.0
# Revision history: 
# 		1.0 - 30/06/2014 : Initial coding (Yannick Castano, Hewlett-Packard)
#
# Pre-requisite: LLDP enables on all switch to switch interfaces
#				 Management IP address configured on the lowest VLAN interface
#
# Remarks:		 This script needs more testing
#				 You can launch server script through scheduler job command
#				 Any comment/feedback is welcome: castano@hp.com
#******************************************************************************
import socket
import os
import re
import sys
import comware

__author__ = 'Yannick Castano'

#******************************************************************************
# Global variables
#******************************************************************************

SERVERPORT = 50000
CLIENTPORT = 50001

#******************************************************************************
# Procedures
#******************************************************************************

def get_lldp_mgt_ip():
	command = comware.CLI('display lldp local-information', False)
	output = command.get_output()
	local_ip = 'none'
	#Extracts the LLDP local IP management address
	for s in output:
		if s.find('Management address') != -1:
			# keeps only the line with the management IP address
			if '.' in s.split()[3]:
				local_ip = s.split()[3]
				break # stops at the first management IP address
	return local_ip
	
def find_local_mac_next_if(mac):
	command = comware.CLI('display mac-address ' + mac, False)
	output = command.get_output()
	if len(output) <= 2:
		# no mac address corresponding, result is empty
		return 'none'
	else:
		# get the third line and extract the local interface
		# first line is the command, second line the header
		result = output[2].split()
		return result [3]

def find_local_arp_ip(mac):
	command = comware.CLI('display arp | include ' + mac, False)
	output = command.get_output()
	if len(output) == 1:
		# no mac address corresponding, result is empty
		return 'none'
	else:
		# get the first line and extract the IP address
		result = output[1].split()
		return result [0]

def find_lldp_neighbor(interface):
	# LLDP rule: the lowest interface ID with an IP address is used as management interface (loopback are excluded)
	command = comware.CLI('display lldp neighbor-information interface ' + interface + ' verbose', False)
	output = command.get_output()
	neighbor = ['none', 'none']
	if len(output) != 1:
		# extracts the LLDP peer name
		for s in output:
			if s.find('System name') != -1:
				neighbor[0] = s.split()[3]
		# extracts the LLDP peer IP management address
		for s in output:
			if s.find('Management address') != -1:
				# keeps only the line with the management IP address
				if '.' in s.split()[3]:
					neighbor[1] = s.split()[3]
	return neighbor

def send_tracemac_request(originhost,neighbor_ip,mac):
	# sending on UDP port 50000
	sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
	sock.connect((neighbor_ip, SERVERPORT))
	sock.sendall(originhost + ' ' + mac)
	sock.close()
	return
	
def send_tracemac_response(remotehost,message):
	# sending on UDP port 50001
	sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
	sock.connect((remotehost, CLIENTPORT))
	sock.sendall(message)
	sock.close()
	return

def convert_interface_name(intf):
	# currently supports 1G, 10G and 40G interfaces
	if intf.find('XGE') != -1:
		interface = intf.replace('XGE','Ten-GigabitEthernet')
	elif intf.find('FGE') != -1:
		interface = intf.replace ('FGE', 'FortyGigE')
	elif intf.find('GE') != -1:
		interface = intf.replace ('GE', 'GigabitEthernet')
	return interface

#******************************************************************************
# Main code
#******************************************************************************
localhost = get_lldp_mgt_ip()
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.bind((localhost, SERVERPORT))
print 'Listening on ' + localhost
while True:
	received_data = sock.recv(1024)
	command_data = received_data.split()
	remotehost = command_data[0]
	mac = command_data[1]
	print 'Sender is: ', remotehost
	print 'Mac to find is: ', mac
	# Try to find if this MAC has a local ARP entry
	ip = find_local_arp_ip(mac.lower())
	if ip != 'none': 
		send_tracemac_response (remotehost,'[' + localhost + ']:\t MAC address {} has IP address {}'.format(mac,ip))
	
	# Find the interface where this MAC has been learned
	intf = find_local_mac_next_if(mac.lower())
	if intf == 'none':
		send_tracemac_response (remotehost,'[' + localhost + ']:\t No corresponding MAC address on this device')
	else:
		interface = convert_interface_name(intf)
		neighbor = find_lldp_neighbor(interface)
		if neighbor[0] == 'none':
			send_tracemac_response (remotehost,'[' + localhost + ']:\t MAC address {} is on {}'.format(mac,interface))
			send_tracemac_response (remotehost,'END')
		else:
			send_tracemac_response (remotehost,'[' + localhost + ']:\t MAC address {} is on {} via switch {} (IP: {})'.format(mac,interface,neighbor[0],neighbor[1]))
			#sending request to the next switch
			send_tracemac_request(remotehost,neighbor[1],mac)