2014-12-22 16:00:45 -05:00

81 lines
2.3 KiB
Python
Executable File

#!/usr/bin/env python
__author__ = "bt3"
import threading
import time
import socket
import os
import struct
import ctypes
from netaddr import IPNetwork, IPAddress
from ICMPHeader import ICMP
# host to listen on
HOST = '192.168.1.114'
# subnet to target (iterates through all IP address in this subnet)
# our local network
SUBNET = '192.168.1.0/24'
# define string signature
MESSAGE = 'hellooooo'
# sprays out the udp datagram
def udp_sender(SUBNET, MESSAGE):
time.sleep(5)
sender = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
for ip in IPNetwork(SUBNET):
try:
sender.sendto(MESSAGE, ("%s" % ip, 65212))
except:
pass
# start sending packets: separated threads to make sure that we are not interfering
# with our ability to sniff responses
t = threading.Thread(target=udp_sender, args=(SUBNET, MESSAGE))
t.start()
def main():
socket_protocol = socket.IPPROTO_ICMP
sniffer = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket_protocol)
sniffer.bind(( HOST, 0 ))
sniffer.setsockopt(socket.IPPROTO_IP, socket.IP_HDRINCL, 1)
# continually read in packets and parse their information
while 1:
# read in a packet and pass the first 20 bytes to initialize the IP structure
raw_buffer = sniffer.recvfrom(65565)[0]
#take first 20 characters for the ip header
ip_header = raw_buffer[0:20]
#unpack them
iph = struct.unpack('!BBHHHBBH4s4s' , ip_header)
# print
version_ihl = iph[0]
ihl = version_ihl & 0xF
iph_length = ihl * 4
src_addr = socket.inet_ntoa(iph[8]);
# create our ICMP structure
buf = raw_buffer[iph_length:iph_length + ctypes.sizeof(ICMP)]
icmp_header = ICMP(buf)
# check for the type 3 and code: first check to make sure that the ICMP
# response is coming from within our target subenet
if icmp_header.code == 3 and icmp_header.type == 3:
# make sure host is in our target subnet
if IPAddress(src_addr) in IPNetwork(SUBNET):
# make sure it has magic message
if raw_buffer[len(raw_buffer) - len(MESSAGE):] == MESSAGE:
print("Host up: %s" % src_addr)
if __name__ == '__main__':
main()