3crwer100-75-telnet-catcher.py

'''

	Date   : 9/19/2015
	Author : Shay Ashkenazi

	Simple Telnet Catcher for 3Com 3CRWER100-75 Router
	==================================================

	As this router boots, port 9000 is opened for only 1 second.
	This simple script will open a connection and leave this port open.
	You may now proceed to Redboot

	Instructions:
	-------------
	1. Ping 192.168.1.1 and make sure you get to the router
	2. Start this script
	3. Power off the router
	4. Connect the router to power
	5. Wait for the connection to be made and this script to finish
	6. Open PuTTY and connect using telnet at port 9000.

	If it doesn't work:
	-------------------
	1. Make sure the router is at 192.168.1.1. Otherwise, change HOST to the proper IP.
	2. Try changing the timeout variable (TOUT).
	3. Try to reset the router before step 1.

'''

import telnetlib

if __name__ == "__main__":

	# Connection variables
	HOST = "192.168.1.1"
	PORT = 9000
	TOUT = 0.5

	# Loop until connected
	connected = False
	while not connected:
		try:
			tn = telnetlib.Telnet(HOST, PORT, TOUT)
			print("connected!")
			connected = True
		except:
			print("can't connect.")

	# Send ^C to stop boot process
	# By that, telnet will stay open
	commands = [b"\x03\n",b"\n"]
	response = ""
	for command in commands:
		response = tn.read_until(b"\n")
		print(HOST + " : " + str(response))
		tn.write(command)
		print("localhost : " + str(command))

	# Now simply connect via simple telnet client, like PuTTY
	print("Done.")