Scapy show CDP info

scapycdp.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import logging
import re

logging.getLogger("scapy").setLevel(logging.ERROR)

from scapy.all import *



def process_packets(pkt):
    """
    Function for processing packets and printing information of CDP Packets
    """
    p = pkt
    # Check if the packet is a CDP Packet
    if Dot3 in p and p.dst == '01:00:0c:cc:cc:cc':
        print "\n*******************************"
        print "Source MAC:", p.src

        # Process each field in the packet message
        for f in p[CDPv2_HDR].fields["msg"]:
            # Check if the filed type is a known one
            if f.type in _cdp_tlv_types:
                # Process each field according to type
                f_type = _cdp_tlv_types[f.type]
                # Make sure we process each address in the message
                if re.match(r"(Addresses|Management Address)", f_type):
                    for ip in f.fields["addr"]:
                        print f_type, ip.addr

                elif f_type == "Software Version":
                    print f_type+":"
                    print "\t" + string.replace(f.val, "\n", "\n\t")
                elif f_type == "Port ID":
                    print f_type, ":", f.iface
                elif f_type == "Capabilities":
                    # Ugly but works :)
                    print f_type, ":", "".join(re.findall(r"cap\s*=(\S*)", str(f.show)))

                elif re.match(r"Native VLAN|VoIP VLAN Reply",f_type):
                    print f_type, ":", f.vlan

                elif f_type == "Duplex":
                    print f_type, ":", _cdp_duplex[f.duplex]

                elif f_type == "IP Prefix":
                    print f_type, ":", f.defaultgw

                elif f_type == "Power":
                    print f_type, ":", f.power, " mW"

                # Fields not yet implemented in the current version of the
                # contributed cdp module.
                elif f_type == "Power Available":
                    # I know, this should provide the amount of power
                    print f_type, ": POE Enabled"

                elif f_type == "Protocol Hello":
                    pass

                else:
                    try:
                        # Make sure we do not have an empty value and print
                        if f.val is not '\0' and len(f.val) != 0: print f_type, ":", f.val


                    except Exception, e:
                        print "ERROR!!!!:", f_type
                        print e
                        pass

if __name__ == "__main__":
    load_contrib("cdp")

    sniff(iface = "eth1", prn = process_packets, store=0)