*/
public final class TelnetSocket extends Socket {
- /**
- * The wrapped socket.
- */
- private Socket socket;
-
/**
* The telnet-aware socket InputStream.
*/
private TelnetInputStream input;
/**
- * The telnet-aware socket OutputStream. Note package private access:
- * input sends stuff to output.
+ * The telnet-aware socket OutputStream.
*/
- TelnetOutputStream output;
+ private TelnetOutputStream output;
// Telnet protocol special characters. Note package private access.
- public static final int TELNET_SE = 240;
- public static final int TELNET_NOP = 241;
- public static final int TELNET_DM = 242;
- public static final int TELNET_BRK = 243;
- public static final int TELNET_IP = 244;
- public static final int TELNET_AO = 245;
- public static final int TELNET_AYT = 246;
- public static final int TELNET_EC = 247;
- public static final int TELNET_EL = 248;
- public static final int TELNET_GA = 249;
- public static final int TELNET_SB = 250;
- public static final int TELNET_WILL = 251;
- public static final int TELNET_WONT = 252;
- public static final int TELNET_DO = 253;
- public static final int TELNET_DONT = 254;
- public static final int TELNET_IAC = 255;
- public static final int C_NUL = 0x00;
- public static final int C_LF = 0x0A;
- public static final int C_CR = 0x0D;
-
- /**
- * Telnet protocol speaks to a Network Virtual Terminal (NVT).
- */
- class TelnetState {
-
- // General status flags outside the NVT spec
- boolean doInit;
- boolean isServer;
-
- // NVT flags
- boolean echoMode;
- boolean binaryMode;
- boolean goAhead;
- boolean doTermType;
- boolean doTermSpeed;
- boolean doNAWS;
- boolean doEnvironment;
- String terminal = "";
-
- // Flags used by the TelnetInputStream
- boolean iac;
- boolean dowill;
- int dowillType;
- boolean subnegEnd;
- boolean isEof;
- boolean eofMsg;
- boolean readCR;
-
- // Flags used by the TelnetOutputStream
- boolean writeCR;
-
- /**
- * Constuctor calls reset().
- */
- public TelnetState() {
- reset();
- }
+ static final int TELNET_SE = 240;
+ static final int TELNET_NOP = 241;
+ static final int TELNET_DM = 242;
+ static final int TELNET_BRK = 243;
+ static final int TELNET_IP = 244;
+ static final int TELNET_AO = 245;
+ static final int TELNET_AYT = 246;
+ static final int TELNET_EC = 247;
+ static final int TELNET_EL = 248;
+ static final int TELNET_GA = 249;
+ static final int TELNET_SB = 250;
+ static final int TELNET_WILL = 251;
+ static final int TELNET_WONT = 252;
+ static final int TELNET_DO = 253;
+ static final int TELNET_DONT = 254;
+ static final int TELNET_IAC = 255;
+ static final int C_NUL = 0x00;
+ static final int C_LF = 0x0A;
+ static final int C_CR = 0x0D;
- /**
- * Reset NVT to default state as per RFC 854.
- */
- public void reset() {
- echoMode = false;
- binaryMode = false;
- goAhead = true;
- doTermType = true;
- doTermSpeed = true;
- doNAWS = true;
- doEnvironment = true;
- doInit = true;
- isServer = true;
-
- iac = false;
- dowill = false;
- subnegEnd = false;
- isEof = false;
- eofMsg = false;
- readCR = false;
-
- writeCR = false;
- }
- }
+ /**
+ * If true, this is a server socket (i.e. created by accept()).
+ */
+ boolean isServer = true;
+
+ /**
+ * If true, telnet ECHO mode is set such that local echo is off and
+ * remote echo is on. This is appropriate for server sockets.
+ */
+ boolean echoMode = false;
+
+ /**
+ * If true, telnet BINARY mode is enabled. We always want this to
+ * ensure a Unicode-safe stream.
+ */
+ boolean binaryMode = false;
+
+ /**
+ * If true, the SUPPRESS-GO-AHEAD option is enabled. We always want
+ * this.
+ */
+ boolean goAhead = true;
+
+ /**
+ * If true, request the client terminal type.
+ */
+ boolean doTermType = true;
+
+ /**
+ * If true, request the client terminal speed.
+ */
+ boolean doTermSpeed = true;
+
+ /**
+ * If true, request the Negotiate About Window Size option to
+ * determine the client text width/height.
+ */
+ boolean doNAWS = true;
+
+ /**
+ * If true, request the New Environment option to obtain the client
+ * LOGNAME, USER, and LANG variables.
+ */
+ boolean doEnvironment;
+
+ /**
+ * The terminal type reported by the client.
+ */
+ String terminalType = "";
/**
- * State of the protocol. Note package private access.
+ * The terminal speed reported by the client.
*/
- TelnetState nvt;
+ String terminalSpeed = "";
/**
* See if telnet server/client is in ASCII mode.
* @return if true, this connection is in ASCII mode
*/
public boolean isAscii() {
- return (!nvt.binaryMode);
+ return (!binaryMode);
}
/**
- * Creates a Socket that knows the telnet protocol.
+ * Creates a Socket that knows the telnet protocol. Note package private
+ * access, this is only used by TelnetServerSocket.
*
- * @param socket the underlying Socket
+ * @throws IOException if an I/O error occurs
*/
- TelnetSocket(Socket socket) throws IOException {
+ TelnetSocket() throws IOException {
super();
- nvt = new TelnetState();
- this.socket = socket;
-
- output = new TelnetOutputStream(this, super.getOutputStream());
- input = new TelnetInputStream(this, super.getInputStream(), output);
-
- // Initiate the telnet protocol negotiation.
- input.telnetSendOptions();
}
// Socket interface -------------------------------------------------------
* Returns an input stream for this socket.
*
* @return the input stream
+ * @throws IOException if an I/O error occurs
*/
@Override
public InputStream getInputStream() throws IOException {
+ if (input == null) {
+ assert (output == null);
+ output = new TelnetOutputStream(this, super.getOutputStream());
+ input = new TelnetInputStream(this, super.getInputStream(), output);
+ input.telnetSendOptions();
+ }
return input;
}
* Returns an output stream for this socket.
*
* @return the output stream
+ * @throws IOException if an I/O error occurs
*/
@Override
public OutputStream getOutputStream() throws IOException {
+ if (output == null) {
+ assert (input == null);
+ output = new TelnetOutputStream(this, super.getOutputStream());
+ input = new TelnetInputStream(this, super.getInputStream(), output);
+ input.telnetSendOptions();
+ }
return output;
}
git://git.nikiroo.be / nikiroo-utils.git / blobdiff