+
+ /**
+ * Determines own remote IP address (e.g. can be used to probe if we are
+ * reachable from outside by determining external address and then connect to it.
+ * This is accomblished by connecting to the IP of www.shipsimu.org which
+ * should default to 188.138.90.169 and requesting /ip.php which does only
+ * return the content of $_SERVER['REMOTE_ADDR']. Of course, this method
+ * requires a working Internet connection.
+ *
+ * This method is taken from a user comment on php.net and heavily rewritten.
+ * Compare to following link:
+ * http://de.php.net/manual/en/function.socket-create.php#49368
+ *
+ * @return $externalAddress The determined external address address
+ * @todo Make IP, host name, port and script name configurable
+ */
+ public static function determineExternalAddress () {
+ // Get helper instance
+ $helperInstance = new ConsoleTools();
+
+ // First get a socket
+ // @TODO Add some DNS caching here
+
+ // Open connection
+ if ($helperInstance->isProxyUsed() === TRUE) {
+ // Resolve hostname into IP address
+ $ip = $helperInstance->resolveIpAddress($helperInstance->getConfigInstance()->getConfigEntry('proxy_host'));
+
+ // Connect to host through proxy connection
+ $socketResource = fsockopen($ip, $helperInstance->getConfigInstance()->getConfigEntry('proxy_port'), $errorNo, $errorStr, 30);
+ } else {
+ // Connect to host directly
+ $socketResource = fsockopen('188.138.90.169', 80, $errorNo, $errorStr, 30);
+ }
+
+ // Check if there was an error else
+ if ($errorNo > 0) {
+ // Then throw again
+ throw new InvalidSocketException(array($helperInstance, $socketResource, $errorNo, $errorStr), BaseListener::EXCEPTION_INVALID_SOCKET);
+ } // END - if
+
+ // Prepare the GET request
+ $request = 'GET ' . ($helperInstance->isProxyUsed() === TRUE ? 'http://shipsimu.org' : '') . '/ip.php HTTP/1.0' . self::HTTP_EOL;
+ $request .= 'Host: shipsimu.org' . self::HTTP_EOL;
+ $request .= 'User-Agent: ' . $this->getUserAgent() . self::HTTP_EOL;
+ $request .= 'Connection: close' . self::HTTP_EOL;
+
+ // Do we use proxy?
+ if ($helperInstance->isProxyUsed() === TRUE) {
+ // CONNECT method?
+ if ($helperInstance->getConfigInstance()->getConfigEntry('proxy_connect_method') == 'Y') {
+ // Setup proxy tunnel
+ $response = $helperInstance->setupProxyTunnel('shipsimu.org', 80, $socketResource);
+
+ // If the response is invalid, abort
+ if ((count($response) == 3) && (empty($response[0])) && (empty($response[1])) && (empty($response[2]))) {
+ // Invalid response!
+ $helperInstance->debugBackTrace('Proxy tunnel not working: response=' . print_r($response, TRUE));
+ } // END - if
+ } else {
+ // Add header for proxy
+ $request .= 'Proxy-Connection: Keep-Alive' . self::HTTP_EOL;
+ }
+ } // END - if
+
+ // Add last HTTP_EOL
+ $request .= self::HTTP_EOL;
+
+ // Send it to the socket
+ fwrite($socketResource, $request);
+
+ // Init IP (this will always be the last line)
+ $externalAddress = 'invalid';
+
+ // And read the reply
+ while (!feof($socketResource)) {
+ // Get line
+ $externalAddress = trim(fgets($socketResource, 128));
+
+ // Detect HTTP response
+ if ((substr($externalAddress, 0, 7) == 'HTTP/1.') && (substr($externalAddress, -6, 6) != '200 OK')) {
+ // Stop processing
+ break;
+ } // END - if
+ } // END - while
+
+ // Close socket
+ fclose($socketResource);
+
+
+ // Debug message
+ /* DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('CONSOLE-TOOLS[' . __METHOD__ . ':' . __LINE__ . ']: Resolved external address: ' . $externalAddress);
+
+ // Return determined external address
+ return $externalAddress;
+ }