PHP to C# - Sockets, or whatever, I dunno

[NickThissen]

Hi,

Sorry for the confusing title, as will become clear shortly this is completely unfamiliar territory for me, so I have really no clue what I'm doing.


Anyway, I am trying to interact with a game server for Call of Duty: Black Ops, this is usually called 'remote console'. I had no idea where to start so I googled around a bit and found a complete web-based remote console implementation (I did not try it but I am assuming it works). Unfortunately, it is in PHP, about which I know absolutely nothing.

The most important file in the PHP implementation, I think, is this:

<?php defined('SYSPATH') or die('No direct script access.');
/**
 * Remote console connection
 *
 * @author      EpicLegion
 * @package     rcon
 * @subpackage  lib
 */
class Rcon {
 
    /**
     * Socket res
     *
     * @var resource
     */
    protected $socket = NULL;
 
    /**
     * Password
     *
     * @var string
     */
    protected $password = '';
 
    /**
     * Host (IP)
     *
     * @var string
     */
    protected $host = '';
 
    /**
     * Serve port
     * @var int
     */
    protected $port = 3074;
 
    /**
     * Constructor
     *
     * @param   string  $host
     * @param   int     $port
     * @param   string  $password
     */
    public function __construct($host = '', $port = 3074, $password = '')
    {
        $this->host = $host;
        $this->port = $port;
        $this->password = $password;
    }
 
    /**
     * Send command
     *
     * @param   string      $command
     * @param   bool        $return_response
     * @throws  Exception
     * @return  mixed
     */
    public function command($command, $return_response = TRUE)
    {
        // No connection
        if(!$this->socket OR !is_resource($this->socket))
        {
            throw new Exception('You must connect to remote console before issuing commands');
        }
 
        // Send command
        fwrite($this->socket, "\xff\xff\xff\xff\x00".$this->password.' '.$command."\x00");
 
        // Wait for response?
        if($return_response)
        {
            // Retrieve reponse
            $response = $this->get_response();
 
            // Invalid password?
            if(trim($response) == 'Invalid password.')
            {
                throw new Exception('Invalid remote console password.');
            }
 
            return $response;
        }
    }
 
    /**
     * Connect to rcon
     *
     * @throws  Exception
     */
    public function connect()
    {
        // Errors
        $errno = 0;
        $errstr = '';
 
        // Open socket
        $this->socket = fsockopen('udp://'.$this->host, $this->port, $errno, $errstr, 5);
 
        // Invalid?
        if(!$this->socket)
        {
            throw new Exception('Cannot connect to remote console');
        }
    }
 
    /**
     * Disconnect
     */
    public function disconnect()
    {
        fclose($this->socket);
    }
 
    /**
     * Read response
     *
     * @return  string
     */
    public function get_response()
    {
        // Var containing response
        $response = '';
 
        // Set socket timeout
        stream_set_timeout($this->socket, 0, 7e5);
 
        // Lol how rare
        do
        {
            // Read 8kb
            $stream_read = fread($this->socket, 8192);
 
            // End of response?
            if(strpos($stream_read, "\x00") !== FALSE)
            {
                // Cut
                $stream_read = substr($stream_read, 0, strpos($stream_read, "\x00"));
            }
 
            // Get socket info
            $stream_info = stream_get_meta_data($this->socket);
 
            // Append
            $response .= substr(trim($stream_read, "\x0a"), 11);
        }
        while(!$stream_info['timed_out']);
 
        // Return
        return $response;
    }
 
    /**
     * Get socket resource
     *
     * @return  resource
     */
    public function get_socket()
    {
        return $this->socket;
    }
 
    /**
     * Set RCON password
     *
     * @param   string  $password
     */
    public function set_password($password = '')
    {
        $this->password = $password;
    }
 
    /**
     * Set server connection details
     *
     * @param   string  $host
     * @param   int     $port
     */
    public function set_server_info($host = '', $port = 3074)
    {
        $this->host = $host;
        $this->port = $port;
    }
}

I can logically split this file into three parts:

1. 'Properties' like Host, Port and Password, including setters / getters / constructor, etc. I can manage this obviously.
2. Connecting and sending commands to the host, as well as receiving a response. This is what I'm having trouble with.
3. Parsing the response into readable chunks. I am not here yet (though I might need some help with that too), I'd rather get item 2 working first.

So, I looked around a bit and found the UdpClient class. The command to connect in the PHP source uses "udp:// ..." so I thought that would be a good place to start.


I wrote this class as a translation of the PHP code, at least the connecting and sending a command part:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
 
namespace BlackOpsRconTest
{
    public class Rcon
    {
        public Rcon(string host, string password)
        {
            this.Host = host;
            this.Port = 3074; // I don't think this can ever change for this game
            this.Password = password;
 
            client = new UdpClient();
        }
 
        public string Host { get; set; }
        public int Port { get; set; }
        public string Password { get; set; }
 
        private readonly UdpClient client;
 
        private static bool messageReceived = false;
 
        public void Connect()
        {
            client.Connect(this.Host, this.Port);
        }
 
        public void Disconnect()
        {
            client.Close();
        }
        
        public void SendCommand(string command)
        {
            // preCommand is supposed to be the '\xff\xff\xff\xff\x00' stuff...
            string preCommand = new String(Convert.ToChar(0xff), 4);
            preCommand += Convert.ToChar(0x00);
 
            // get the bytes to send
            // this spells     \xff\xff\xff\xff\x00<password> <command>\x00
            // as in the PHP source...
            var commandBytes = Encoding.ASCII.GetBytes(String.Format("{0}{1} {2}{3}",
                                                                     preCommand,
                                                                     this.Password,
                                                                     command,
                                                                     Convert.ToChar(0x00)));
            // Send it!
            client.Send(commandBytes, commandBytes.Length);
 
 
            // Now listen for response.
            IPEndPoint e = new IPEndPoint(IPAddress.Any, this.Port);
            UdpState s = new UdpState();
            s.e = e;
            s.u = client;
 
            Console.WriteLine("listening for messages");
            client.BeginReceive(new AsyncCallback(ReceiveCallback), s);
 
            // Do some work while we wait for a message. For this example,
            // we'll just sleep
            while (!messageReceived)
            {
                Thread.Sleep(100);
            }
        }
 
        private static void ReceiveCallback(IAsyncResult ar)
        {
            UdpClient u = (UdpClient)((UdpState)(ar.AsyncState)).u;
            IPEndPoint e = (IPEndPoint)((UdpState)(ar.AsyncState)).e;
 
            Byte[] receiveBytes = u.EndReceive(ar, ref e);
            string receiveString = Encoding.ASCII.GetString(receiveBytes);
 
            Console.WriteLine("Received: {0}", receiveString);
            messageReceived = true;
        }
 
        struct UdpState
        {
            public UdpClient u;
            public IPEndPoint e;
        }
 
    }
}

The sending part is mostly 'made up', I assumed that the \xff and \x00 stuff was hex so I used Convert.ToChar to convert those hex numbers to characters and insert them before the actual command to send, just like the PHP source code does (at least: i think it does that, I may be completely wrong here as I have no clue how PHP works).

The receiving part is straight from MSDN.

I am trying to use it as such:

Rcon r = new Rcon("173.199.111.167", "mypassword");
            r.Connect();
            r.SendCommand("teamstatus");

"teamstatus" is supposed to be a valid command that should result in the server returning the players and their status (name, id, score, ping, etc).


When I try to run this, nothing happens. The console displays "listening for messages" but nothing after that. I waited a few minutes but no response ever came.


What am I doing wrong? As I said, I am completely new to this (both the PHP and to 'socket' stuff in general) so I really have no clue what I'm doing. At this point basically I'm trying to hack together a translation and I'm just looking to get A response, no matter what.

Thanks!