<?PHP

  require_once ("flap.php");
  
  class proxyOscar {
    private $RemoteAddr = "";
    private $RemoteCookie = "";
    
    private $Listener = null;
    private $Local = null;
    private $Remote = null;
    
    private $Authenticated = false;
    
    private $ClientIP = "";
    private $ClientPort = 0;
    private $ClientUser = "";
    
    private $Log = true;
    private $LogFD = null;
    
    function __construct ($Socket, $User = "") {
      // Create our BOS-Socket
      print "Creating local BOS-Forwarder for $User\n";
      
      $this->ClientUser = $User;
      $this->Listener = socket_create (AF_INET, SOCK_STREAM, SOL_TCP); 
      
      socket_getsockname ($Socket, $IP);
      socket_bind ($this->Listener, $IP);
      socket_listen ($this->Listener);
      
      // Remember this context
      self::restoreListener ();
    }
    
    public function handle ($Socket) {
      // Process an incoming connection
      if ($Socket == $this->Listener) {
        // Assign sockets
        $this->Local = socket_accept ($this->Listener);
        $this->Remote = socket_create (AF_INET, SOCK_STREAM, SOL_TCP);
        
        // Connect remote side
        $p = strpos ($this->RemoteAddr, ":");
        
        socket_connect ($this->Remote, substr ($this->RemoteAddr, 0, $p), intval (substr ($this->RemoteAddr, $p + 1)));
        
        $this->Authenticated = false;
        
        setContextSocket ($this->Local, $this);
        setContextSocket ($this->Remote, $this);
        
        // Stop waiting for events here
        unsetSocketContext ($this->Listener);
        
        socket_getpeername ($this->Local, $this->ClientIP, $this->ClientPort);
        
        print "Accepting connection on BOS-Forwarder from " . $this->ClientIP . ":" . $this->ClientPort . "\n";
        
        return;
      
      } elseif ($Socket == $this->Remote) {
        if (!($Flap = flapRead ($this->Remote, true, "BOS<<")))
          return $this->close ("Read FLAP from remote");
        
        self::log ($Flap, false);
        
        writeFlap ($this->Local, $Flap, false, "BOS>>");
        
        return;
      }
      
      // Read Flap from local connection
      if (!($Flap = flapRead ($this->Local, true, "BOS>>")))
        return $this->close ("Read FLAP from client");
      
      // Try to authenticate client
      if (!$this->Authenticated) {
        // Check initial version on FLAP
        if (substr ($Flap ["Payload"], 0, 4) != chr (0) . chr (0) . chr (0) . chr (1))
          return $this->close ("Invalid protocol");
        
        // Create a copy of the Flap
        $xFlap = $Flap;
        
        // Remove version from Flap
        $xFlap ["Payload"] = substr ($xFlap ["Payload"], 4);
        $xFlap ["Length"] -= 4;
        
        // Read TLVs from CLI_COOKIE
        $TLV = flapTreatTLV ($xFlap);
        
        // Search for a cookie
        $haveCookie = false;
        
        foreach ($TLV as $Item)
          if (($Item ["Type"] == 0x0006) && ($haveCookie = ($Item ["Payload"] == $this->RemoteCookie)))
            break;
        
        if (!$haveCookie)
          return $this->close ("Cookie missing");
        
        print "BOS-Connection authenticated\n";
        
        // Initiate remote connection
        $this->Authenticated = true;
        
        // Remove the listening socket
        socket_shutdown ($this->Listener, 2);
        socket_close ($this->Listener);
      }
      
      self::log ($Flap, true);
      
      // Forward FLAP to remote side
      writeFlap ($this->Remote, $Flap, false, "BOS<<");
    }
    
    private function restoreListener () {
      // Set context for listener socket
      setContextSocket ($this->Listener, $this);
    }
    
    public function setAddress ($Address) {
      $this->RemoteAddr = $Address;
    }
    
    public function setCookie ($Cookie) {
      $this->RemoteCookie = $Cookie;
    }
    
    public function getAddress () {
      socket_getsockname ($this->Listener, $IP, $Port);
      
      return $IP . ":" . $Port;
    }
    
    private function log ($Flap, $fromClient) {
      // Make sure that log is open
      if (!is_resource ($this->logFD)) {
        if (!is_resource ($this->logFD = @fopen ("logs/" . $this->ClientUser . "_" . time () . ".xml", "w")))
          return;
        
        // Start logging
        fwrite ($this->logFD, "<oscar>\n");
      }
      
      // Log header of Flap
      fwrite ($this->logFD, "  <flap channel='" . $Flap ["Channel"] . "' sequence='" . $Flap ["Sequence"] . "' from='" . ($fromClient ? "client" : "server") . "' stamp='" . time () . "'>\n");
      
      // Log payload of Flap
      if ($Flap ["Length"] > 0) {
        // Log payload of Flap
        fwrite ($this->logFD,
          "    <payload length='" . $Flap ["Length"] . "'>\n" .
          htmlentities (dumpData ($Flap ["Payload"], "      ", true)) .
          "    </payload>\n");
        
        // Handle SNACs on Channel 0x02
        if ($Flap ["Channel"] == 0x02) {
          $SNAC = flapReadSNAC ($Flap);
          
          fwrite ($this->logFD,
            "    <snac family='0x" . dechex ($SNAC ["Family"]) . "' type='0x" . dechex ($SNAC ["Subtype"]) . "' flags='0x" . dechex ($SNAC ["Flags"]) . "' sequence='0x" . dechex ($SNAC ["Subtype"]) . "'>\n" .
            "      <payload length='" . strlen ($SNAC ["Payload"]) . "'>\n" .
            htmlentities (dumpData ($SNAC ["Payload"], "      ", true)) .
            "      </payload>\n");
          
          // Handle TLVs on SNAC
          global $TLV_SNACs;
          
          if (isset ($TLV_SNACs [$SNAC ["Family"]]) && in_array ($SNAC ["Subtype"], $TLV_SNACs [$SNAC ["Family"]])) {
            $Items = flapTreatTLV ($SNAC);
            
            foreach ($Items as $Item)
              fwrite ($this->logFD,
                "      <tlv type='0x" . dechex ($Item ["Type"]) . "' length='" . $Item ["Length"] . "'>\n" .
                htmlentities (dumpData ($Item ["Payload"], "        ", true)) .
                "      </tlv>\n");
          }
          
          fwrite ($this->logFD, "    </snac>\n");
        }
      }
      
      // Close the Flap on log
      fwrite ($this->logFD, "  </flap>\n");
    }
    
    private function closeLog () {
      // Check if the log is already closed
      if (!is_resource ($this->logFD))
        return;
      
      // Close the log
      fwrite ($this->logFD, "</oscar>\n");
      fclose ($this->logFD);
      
      $this->logFD = null;
    }
    
    protected function close ($Reason = "") {
      if (is_resource ($this->Local)) {
        print "Client on BOS discarded\n";
        
        if ($Reason != "")
          print "Reason: " . $Reason . "\n";
        
        unsetSocketContext ($this->Local);   
        unsetSocketContext ($this->Remote);
       
        socket_shutdown ($this->Local, 2);
        socket_close ($this->Local);
        
        socket_shutdown ($this->Remote, 2);
        socket_close ($this->Remote);
      }
      
      self::closeLog ();
      
      if (!$this->Authenticated)
        return $this->restoreListener ();
    }
  }

?>