Add master server web page CGI script to display a list of active

servers.

Subversion-branch: /master
Subversion-revision: 2199

web/index.py

@@ -0,0 +1,170 @@
+#!/usr/bin/env python
+#
+# Copyright(C) 2010 Simon Howard
+#
+# 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 2
+# 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, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+# 02111-1307, USA.
+#
+#
+# CGI script that generates master server web page.
+#
+
+from cgi import escape
+from time import time
+from select import select
+import socket
+import sys
+import struct
+import simplejson
+
+NET_MASTER_PACKET_TYPE_GET_METADATA = 4
+NET_MASTER_PACKET_TYPE_GET_METADATA_RESPONSE = 5
+
+METADATA_GATHER_TIME = 0.1 # seconds
+
+MASTER_SERVER = "master.chocolate-doom.org"
+UDP_PORT = 2342
+
+def send_message(sock, addr, message_type, payload=None):
+    header = struct.pack(">h", message_type)
+    packet = header
+
+    if payload is not None:
+        packet += payload
+
+    sock.sendto(packet, addr)
+
+def read_string(packet):
+    terminator = struct.pack("b", 0)
+    strlen = packet.index(terminator)
+
+    result, = struct.unpack("%ss" % strlen, packet[0:strlen])
+
+    return packet[strlen + 1:], result
+
+def decode_string_list(packet):
+    """ Decode binary data containing NUL-terminated strings. """
+
+    strings = []
+
+    while len(packet) > 0:
+        packet, string = read_string(packet)
+
+        strings.append(string)
+
+    return strings
+
+def process_metadata_response(packet):
+    """ Process a response received from the master server. """
+
+    type, = struct.unpack(">h", packet[0:2])
+
+    if type != NET_MASTER_PACKET_TYPE_GET_METADATA_RESPONSE:
+        raise Exception("Wrong packet type received: %i" % type)
+
+    # Process the payload data (list of NUL-terminated strings)
+
+    strings = decode_string_list(packet[2:])
+
+    # Each string is a JSON-encoded dictionary.  Decode these.
+
+    return map(simplejson.loads, strings)
+
+def get_metadata(addr_str):
+    """ Query a master server for metadata about its servers. """
+
+    addr = (socket.gethostbyname(addr_str), UDP_PORT)
+    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+
+    # Send request to master.
+
+    send_message(sock, addr, NET_MASTER_PACKET_TYPE_GET_METADATA)
+
+    # Wait for METADATA_GATHER_TIME seconds to receive responses from
+    # the master.  There may be multiple response packets if there are
+    # lots of servers.
+
+    servers = []
+    start_time = time()
+
+    while time() < start_time + METADATA_GATHER_TIME:
+        r, w, x = select([sock], [], [], METADATA_GATHER_TIME)
+
+        if sock in r:
+            packet, remote_addr = sock.recvfrom(1024)
+
+            servers += process_metadata_response(packet)
+
+    return servers
+
+# CGI script to print out server list.
+
+def get_server_data():
+    """ Query the master server and retrieve server metadata. """
+
+    return get_metadata(MASTER_SERVER)
+
+def generate_table_row(server):
+    """ Generate a row of the HTML table, containing data for a
+        particular server. """
+
+    data = [
+        "%s:%i" % (server["address"], server["port"]),
+        escape(server["name"]),
+        escape(server["version"]),
+        server["max_players"]
+    ]
+
+    result = []
+
+    for col in data:
+        result.append("    <td>%s</td>\n" % col)
+
+    return "<tr>\n" + ("".join(result)) + "</tr>\n"
+
+def generate_table(server_data):
+    """ Generate an HTML table from list of server metadata. """
+
+    result = []
+
+    for server in server_data:
+        result.append(generate_table_row(server))
+
+    return "\n".join(result)
+
+def read_template(filename):
+    """ Read HTML template file. """
+
+    file = open(filename)
+    result = file.read()
+    file.close()
+
+    return result
+
+def output_html(html):
+    """ Output HTML data back to client. """
+
+    print "Content-Type: text/html"
+    print
+    print html
+
+template = read_template("index.template")
+
+server_data = get_server_data()
+table_data = generate_table(server_data)
+html = template.replace("___TABLE_DATA___", table_data)
+
+output_html(html)
+

web/index.template

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+<html>
+
+<head>
+<link rel="stylesheet" href="style.css" type="text/css">
+<title> Chocolate Doom master server </title>
+</head>
+
+<body>
+<img id="cocoademon" src="cocoademon.png" alt="Cocoademon">
+<h1> Chocolate Doom master server </h1>
+
+<p> Currently active servers: </p>
+
+<table>
+<tr>
+<th> Server address
+<th> Server name
+<th> Version
+<th> Max. players
+
+___TABLE_DATA___
+
+</table>
+
+<p>
+For more information, see
+<a href="http://www.chocolate-doom.org/">the website</a>.
+</p>
+
+</body>
+</html>
+

web/style.css

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+body {
+    background-color: black;
+    color: white;
+}
+
+table {
+    border-color: white;
+    border-width: 0 0 1px 1px;
+    border-style: solid;
+    border-collapse: collapse;
+}
+
+td, th {
+    text-align: left;
+    border-color: white;
+    border-width: 1px 1px 0 0;
+    border-style: solid;
+    margin: 0;
+    padding: 4px;
+}
+
+#cocoademon {
+    float: right;
+    width: 150px;
+    border: 0px;
+    padding-right: 20px;
+    padding-top: 20px;
+}
+