import sys
import json
from collections import defaultdict
+from decimal import *
+
+ROUTER_MAC = "b0:b9:8a:73:69:8e"
JSON_KEY_SOURCE = "_source"
JSON_KEY_LAYERS = "layers"
JSON_KEY_DNS_A = "dns.a" # Key for retrieving IP. 'a' for type A DNS record.
JSON_KEY_DNS_RESP_NAME = "dns.resp.name"
JSON_KEY_DNS_CNAME = "dns.cname"
+JSON_KEY_ETH = "eth"
+JSON_KEY_ETH_DST = "eth.dst"
+JSON_KEY_FRAME = "frame"
+JSON_KEY_FRAME_TIME_EPOCH = "frame.time_epoch"
def main():
if len(sys.argv) < 2:
print "Usage: python", sys.argv[0], "input_file"
return
- maps_tuple = parse_json(sys.argv[1])
-
- # print hostname to ip map
- hn_ip_map = maps_tuple[0]
- for hn in hn_ip_map.keys():
- print "====================================================================="
- print hn, "maps to:"
- for ip in hn_ip_map[hn]:
- print " -", ip
- print "====================================================================="
+ mac_to_ddm = parse_json_dns(sys.argv[1])
+ for mac in mac_to_ddm:
+ ddm = mac_to_ddm[mac]
+ ddm.print_mappings()
+ # maps_tuple = parse_json_dns(sys.argv[1])
- print " "
+ # # print hostname to ip map
+ # hn_ip_map = maps_tuple[0]
+ # for hn in hn_ip_map.keys():
+ # print "====================================================================="
+ # print hn, "maps to:"
+ # for ip in hn_ip_map[hn]:
+ # print " -", ip
+ # print "====================================================================="
- # print ip to hostname map
- ip_hn_map = maps_tuple[1]
- for ip in ip_hn_map.keys():
- print "====================================================================="
- print ip, "maps to:"
- for hn in ip_hn_map[ip]:
- print " -", hn
- print "====================================================================="
-
-# Convert JSON file containing DNS traffic to a tuple with two maps.
-# Index 0 of the tuple is a map in which a hostname points to its set of associated IPs.
-# Index 1 of the tuple is a map in which an ip points to its set of associated hostnames.
-def parse_json(file_path):
- # Maps hostnames to IPs
- host_ip_mappings = defaultdict(set)
- # Maps ips to hostnames
- ip_host_mappings = defaultdict(set)
+ # print " "
+
+ # # print ip to hostname map
+ # ip_hn_map = maps_tuple[1]
+ # for ip in ip_hn_map.keys():
+ # print "====================================================================="
+ # print ip, "maps to:"
+ # for hn in ip_hn_map[ip]:
+ # print " -", hn
+ # print "====================================================================="
+
+class DeviceDNSMap:
+ def __init__(self, mac_address):
+ # MAC address of device
+ self.mac = mac_address
+ # Maps an external IP to a list of (timestamp,hostname) tuples.
+ # Entries in the list should be interpreted as follows:
+ # the timestamp indicates WHEN this device mapped the given ip (key in dict) to the hostname.
+ self.ip_mappings = defaultdict(list)
+
+ def hostname_for_ip_at_time(self, ip, timestamp):
+ # Does device have a mapping for the given IP?
+ if not ip in self.ip_mappings:
+ return None
+ if not self.ip_mappings[ip]:
+ # If list of (timestamp,hostname) tuples is empty, there is no mapping to report.
+ return None
+ # Best fit mapping: the mapping immediately BEFORE timestamp parameter.
+ # Start with random pick (element 0).
+ best_fit = self.ip_mappings[ip][0]
+ for t in self.ip_mappings[ip]:
+ # t is a (timestamp,hostname) tuple
+ if t[0] < timestamp and t[0] > best_fit[0]:
+ # t is a better fit if it happened BEFORE the input timestamp
+ # and is LATER than the current best_fit
+ best_fit = t
+ # return the matching hostname
+ return best_fit[1]
+
+ def add_mapping(self, ip, timestamp_hostname_tuple):
+ self.ip_mappings[ip].append(timestamp_hostname_tuple)
+
+ def print_mappings(self):
+ count = 0
+ print "### Mappings for MAC = ", self.mac, "###"
+ for ip in self.ip_mappings:
+ print "--- IP ", ip, " maps to: ---"
+ for t in self.ip_mappings[ip]:
+ print t[1], "at epoch time =", t[0]
+ count += 1
+ print "### Total of", count, "mappings for", self.mac, "###"
+
+ # --------------------------------------------------------------------------
+ # Define eq and hash such that instances of the class can be used as keys in dictionaries.
+ # Equality is based on MAC as a MAC uniquely identifies the device.
+ def __eq__(self, another):
+ return hasattr(another, 'mac') and self.mac == another.mac
+ def __hash__(self):
+ return hash(self.data)
+ # --------------------------------------------------------------------------
+
+
+def parse_json_dns(file_path):
+ # Our end output: dictionary of MAC addresses with DeviceDNSMaps as values.
+ # Each DeviceDNSMap contains DNS lookups performed by the device with the corresponding MAC.
+ result = defaultdict()
with open(file_path) as jf:
# Read JSON.
# data becomes reference to root JSON object (or in our case json array)
if len(queries.keys()) > 1:
# Unclear if script will behave correctly for DNS lookups with multiple queries
print "[ WARNING: Multi query DNS lookup ]"
+ # Get ethernet information for identifying the device performing the DNS lookup.
+ eth = layers.get(JSON_KEY_ETH, None)
+ if eth is None:
+ print "[ WARNING: eth data not found ]"
+ continue
+ # As this is a response to a DNS query, the IoT device is the destination.
+ # Get the device MAC of that device.
+ device_mac = eth.get(JSON_KEY_ETH_DST, None)
+ if device_mac is None:
+ print "[ WARNING: eth.dst data not found ]"
+ continue
+ # Get the router's timestamp for this packet
+ # so that we can mark when the DNS mapping occurred
+ timestamp = Decimal(layers[JSON_KEY_FRAME][JSON_KEY_FRAME_TIME_EPOCH])
for ak in answers.keys():
a = answers[ak]
# We are looking for type A records as these are the ones that contain the IP.
# The answer may be the canonical name.
# Now trace back the answer stack, looking for any higher level aliases.
hostname = find_alias_hostname(answers, a[JSON_KEY_DNS_RESP_NAME])
- # Add mapping of hostname to ip to our data structure
- host_ip_mappings[hostname].add(ip)
- # Add mapping of ip to hostname to our data structure
- ip_host_mappings[ip].add(hostname)
- return (host_ip_mappings, ip_host_mappings)
+ # Create the tuple that indicates WHEN the ip to hostname mapping occurred
+ timestamp_hostname_tuple = (timestamp,hostname)
+ if device_mac in result:
+ # If we already have DNS data for the device with this MAC:
+ # Add the mapping to the DeviceDNSMap that is already present in the dict.
+ result[device_mac].add_mapping(ip, timestamp_hostname_tuple)
+ else:
+ # No DNS data for this device yet:
+ # Create a new DeviceDNSMap, add the mapping, and at it to the dict.
+ ddm = DeviceDNSMap(device_mac)
+ ddm.add_mapping(ip, timestamp_hostname_tuple)
+ result[device_mac] = ddm
+ return result
# Recursively traverse set of answers trying to find the top most alias for a canonical name
def find_alias_hostname(answers, hostname):
projects / pingpong.git / blobdiff