#! /usr/bin/env python
# Copyright (c) 2008, Arne Brodowski, http://www.arnebrodowski.de
# All rights reserved.
# 
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
# 
# * Redistributions of source code must retain the above copyright
#   notice, this list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above
#   copyright notice, this list of conditions and the following
#   disclaimer in the documentation and/or other materials provided
#   with the distribution.
#
# * Neither the name of the author nor the names of other
#   contributors may be used to endorse or promote products derived
#   from this software without specific prior written permission.
# 
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

import socket
import sys

def serve():
    """
    Run a proxy which forwards broadcast requests to a port to a given
    IP address. This makes it possible to bind HL servers to a fixed IP but
    discover them using the in-games client or other browsers in a lan
    environment.
    Works only on Linux.
    """
    server = sys.argv[1]
    host = '<broadcast>'
    try:
        port = int(sys.argv[2])
    except:
        port = 27015
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    sock.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
    sock.bind((host,port))

    sock2 = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    sock2.settimeout(2)

    while 1:
        msg, addr = sock.recvfrom(8192)
        print "%s :: %s" % (addr,msg)
        try:
            sock2.sendto(msg, (server,port))
            resp, adr = sock2.recvfrom(8192)
            if resp:
                sock.sendto(resp, addr)
        except socket.error:
            pass

def usage():
	print "Usage: %s hl-sever-ip-address [port if not 27015]" % __file__
			
if __name__ == "__main__":
    if not len(sys.argv) == 2 or len(sys.argv) == 3:
        usage()
    else:
        serve()