#!/usr/bin/python

# srcupdatecheck v7 - part of
# NemRun v1.2 - Nephyrin@Doublezen.net, 07/11/2010

# Copyright © 2010 Nephyrin@DoubleZen.net
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import socket
import struct
import sys
import re

# Master server to ping for version. There are many masters/ports, but valve
# advises we use this one, which is a round robin.
host = "hl2master.steampowered.com"
port = 27011

fakeport = 47015
# You will register one 'fake' server on the master list on this port for check
# reasons (it wont respond/be visible) We used to register on port '0', which
# caused no erroneous listings, but valve broke that on 03/03/2010 when they
# fixed people spamming listings.

if not len(sys.argv) == 2:
	print "Usage: ./srcupdatecheck /path/to/steam.inf"
	sys.exit(-1)

#
# Read PatchVersion from provided steam.inf
#
try:
	steaminf = open(sys.argv[1])
except IOError:
	print "File \"%s\" does not exist!" % sys.argv[1]
	sys.exit(-1)

verstring = steaminf.readline()
verre = re.search('PatchVersion=([^\r\n]+)', verstring)

if not verre:
	print "Invalid steam.inf file."
	sys.exit(-1)

ver = verre.group(1)

#
# Read ProductName
#

prodstring = steaminf.readline()
prodre = re.search('ProductName=([^\r\n]+)', prodstring)

if not prodre:
	print "Invalid steam.inf file."
	sys.exit(-1)

game = prodre.group(1)

#
# And AppID
#

appstring = steaminf.readline()
appre = re.search('appID=([^\r\n]+)', appstring)

if not appre:
	print "Invalid steam.inf file."
	sys.exit(-1)

appid = appre.group(1)

print "%s%s%s" % (prodstring,appstring,verstring)

# Recv, filtering out 0x52 packets, which are A2C_PRINT - they often arrive
# out of order and unsolicited, and dont contain anything we need.
def recvfilt(sock):
	somebuffer = sock.recv(2048);
	if (somebuffer.startswith(struct.pack("<iB", -1, 0x52))):
		return recvfilt(sock);
	return somebuffer;

def tryCheck(attempt):
	#
	# Create socket and send master_getchallenge (0x71)
	#
	# print "[%i] Creating socket" % attempt
	s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
	# print "[%i] Connecting" % attempt
	# s.bind(("0.0.0.0", fakeport))
	s.connect((host, port))
	print "[%i] Requesting challenge" % attempt
	s.sendall("\x4D\xFF")
	s.settimeout(3.0)
	# print "[%i] Waiting for reponse" % attempt
	#
	# Receive challenge
	#

	try:
		buf = recvfilt(s)
	except socket.timeout:
		print "[%i] - Timed out contacting server" % attempt
		return -1

	#
	# Pack challenge and product version into dummy query
	#
	challenge = struct.unpack("8xI", "\xFF\xFF%s" % buf)[0]
	print "[%i] Got challenge, sending registration" % attempt
	query = "\x30\x0A\\protocol\\7\\challenge\\%u\\players\\0\\max\\24\\bots\\0\\gamedir\\%s\\map\\neph_vercheck\\password\\0\\os\\l\\lan\\0\\region\\255\\gameport\\%i\\specport\\0\\dedicated\\1\\gametype\\ctf\\appid\\%s\\type\\d\\secure\\1\\version\\%s\\product\\%s\x0A" % (challenge, game, fakeport, appid, ver, game)
	s.sendall(query)
	s.shutdown(1)

	#
	# Wait 3s for out-of-date response. If no response received, we're up to date.
	# (not the best method ever, but if we got a challenge it's pretty
	# reliable - plus the error is false negative)
	#
	# print "[%i] Waiting for response" % attempt
	try:
		buf2 = recvfilt(s)
		if (buf2 == struct.pack("<iBI", -1, 0x4f, challenge)):
			print "[%i] - Got out of date message" % attempt
			return 1
		else:
			print "[%i] - Got unexpected message from master (bad challenge?). Retrying" % attempt
			return -1
	except socket.timeout:
		print "[%i] - No response" % attempt
		return 0

validattempts = 0;
attempt = 1;
while (validattempts < 3):
	ret = tryCheck(attempt);
	attempt += 1
	if (ret == 0):
		validattempts += 1
	elif (ret == 1):
		print "Got definite out of date message. OUT OF DATE!"
		sys.exit(7)

print "Got three non-rejected queries, UP TO DATE!"