#!/usr/bin/env python
# This is Pytecache.  See the file README in this directory for information.
# Pytecache is Copyright (C) 2000 Tom Goulet.
# This program is protected under the terms of the GNU General Public
# License version 2, see the file COPYING in this directory.
# Pytecache requires a pickled hosts list named 'hosts' to function.
import sys				# for sys.exit()
import string				# for string manipulation
import pickle				# for loading the hosts list
from socket import *			# for scoket operations

def makeguid():			# Create a random message identifier.
	guid = ''		# Initialise as empty string.
	for i in range(16):	# guids are 128 bits, which is 16 bytes.
		guid = guid + chr(whrandom.randint(0, 255))#
	return(guid)		# Return the random message identifier.

def sendping():                 # Send a ping out
        guid = ''               # random identifier
        flag = '\000'           # ping
        ttl = '\004'            # default ttl of 4
        hops = '\000'           # default hops of 0
        payloadsize = '\000\000\000\000'# pings have precisely 0 payload
	guid = makeguid()	# Generated random GUID.
	sendstring = guid+flag+ttl+hops+payloadsize# make a sendstring
	s.send(sendstring)	# Send it
        print "Sent ping:", `sendstring`#diagnostic
        return()                # Done, now.


f = open("hosts", "r")			# Open the hosts file
hosts = pickle.load(f)			# Read it into a variable
s = socket(AF_INET, SOCK_STREAM)	# Create socket...
s.bind('', 6346)			# Bind to localhost:6346
print "bound"				# diagnostic
s.listen(1)				# Listen on port
print "listening"			# diagnostic
while 1:				# Loop forever
	print "Main loop."#diagnostic
	conn, addr = s.accept()		# accept a connection
	print "conn, addr = s.accept()", `conn`, `addr`#diagnostic
	handshake = conn.recv(64)	# receive handshake
	if not handshake:		# It was in the example...I'm copying it
		print "'if not handshake:' returned true"#diagnostic
		conn.close()		# I assume this is a good idea
		#break
	print "got handshake:", `handshake`#diagnostic
	if handshake == 'GNUTELLA CONNECT/0.4\n\n':#Specification's handshake
		conn.send('GNUTELLA OK\n\n')# Shake back.
		print "sent response: GNUTELLA OK\\n\\n"#diagnostic
	else:				#Got something I didn't expect...
		print "handshake barfed"#diagnostic
		conn.close()		# Close connection
		#break
	for i in range(4):		# Don't deal with more than four packets
		print "packet loop"#diagnostic
		rheader = conn.recv(23) 
		print "header received:",`rheader`
		if rheader[16] == '\000':
			print "ping with",
			guid = rheader[0:16]
			print "a guid of", `guid`
			for i in hosts:
				h = string.split(i[0], '.')
				host = chr(int(h[0])) + chr(int(h[1])) + chr(int(h[2])) + chr(int(h[3]))
				port = chr(i[1] % 256) + chr(i[1] / 256)
				sheader = guid+'\001\004\000\016\000\000\000'
				print "Sending header:", `sheader`
				conn.send(sheader)
				spayload = port+host+'\000\000\000\000\000\000\000\000'
				print "Sending payload:", `spayload`
				conn.send(spayload)
			print "pong flood sent."
			conn.close()
			break
		else:
			print "header", `rheader[16]`, "is not a ping"
			pll = ord(rheader[19]) + ord(rheader[20])*256 + ord(rheader[21])*65536 + ord(rheader[22])*16777216
			#print "header says payload is this long:", pll
			rpayload = conn.recv(pll)
			#print "Received payload:",`payload`
	print "four packets or pongflood accomplished"
	conn.close()

# EOF