org.jline.builtins.telnet.TelnetIO Maven / Gradle / Ivy
/*
* Copyright (c) 2002-2018, the original author or authors.
*
* This software is distributable under the BSD license. See the terms of the
* BSD license in the documentation provided with this software.
*
* https://opensource.org/licenses/BSD-3-Clause
*/
/*
* Java TelnetD library (embeddable telnet daemon)
* Copyright (c) 2000-2005 Dieter Wimberger
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the author nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS ``AS
* IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
***/
package org.jline.builtins.telnet;
import java.io.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.InetAddress;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Class that represents the TelnetIO implementation. It contains
* an inner IACHandler class to handle the telnet protocol level
* communication.
*
* Although supposed to work full-duplex, we only process the telnet protocol
* layer communication in case of reading requests from the higher levels.
* This is the only way to meet the one thread per connection requirement.
*
*
* The output is done via byte-oriented streams, definately suitable for the
* telnet protocol. The format of the output is UTF-8 (Unicode), which is a
* standard and supported by any telnet client, including the ones included
* in Microsoft OS's.
*
* Notes:
*
* - The underlying output is buffered, to ensure that all bytes written
* are send, the flush() method has to be called.
*
- This low-level routines ensure nice multithreading behaviour on I/O.
* Neither large outputs, nor input sequences excuted by the connection thread
* can hog the system.
*
*
* @author Dieter Wimberger
* @version 2.0 (16/07/2006)
*/
public class TelnetIO {
/**
* Interpret As Command
*/
protected static final int IAC = 255;
/**
* Go Ahead
Newer Telnets do not make use of this option
* that allows a specific communication mode.
*/
protected static final int GA = 249;
/**
* Negotiation: Will do option
*/
protected static final int WILL = 251;
/**
* Negotiation: Wont do option
*/
protected static final int WONT = 252;
/**
* Negotiation: Do option
*/
protected static final int DO = 253;
/**
* Negotiation: Dont do option
*/
protected static final int DONT = 254;
/**
* Marks start of a subnegotiation.
*/
protected static final int SB = 250;
/**
* Marks end of subnegotiation.
*/
protected static final int SE = 240;
/**
* No operation
*/
protected static final int NOP = 241;
/**
* Data mark its the data part of a SYNCH which helps to clean up the buffers between
* Telnet Server <-> Telnet Client.
* It should work like this we send a TCP urgent package and <IAC> <DM> the receiver
* should get the urgent package (SYNCH) and just discard everything until he receives
* our <IAC> <DM>.
* Remark:
*
* - can we send a TCP urgent package?
*
- can we make use of the thing at all?
*
*/
protected static final int DM = 242;
/**
* Break
*/
protected static final int BRK = 243;
/**
* Interrupt Process
*/
protected static final int IP = 244;
/**
* Abort Output
*/
protected static final int AO = 245;
/**** Implementation of OutputStream ****************************************************/
/**
* Are You There
*/
protected static final int AYT = 246;
/**
* Erase Char
*/
protected static final int EC = 247;
/**
* Erase Line
*/
protected static final int EL = 248;
/**
* Telnet Option: ECHO
*/
protected static final int ECHO = 1;
/**
* Telnet Option: SUPress Go Ahead
* This will be negotiated, all new telnet protocol implementations are
* recommended to do this.
*/
protected static final int SUPGA = 3;
/**
* Telnet Option: Negotiate About Window Size
*
* - Server request is IAC DO NAWS
*
- Client response contains subnegotiation with data (columns, rows).
*
*/
protected static final int NAWS = 31;
/**
* Telnet Option: Terminal TYPE
*
* - Server request contains subnegotiation SEND
*
- Client response contains subnegotiation with data IS,terminal type string
*
*/
protected static final int TTYPE = 24;
/**
* TTYPE subnegotiation: IS
*/
protected static final int IS = 0;
/**
* TTYPE subnegotiation: SEND
*/
protected static final int SEND = 1;
/**** End implementation of OutputStream ***********************************************/
/**** Implementation of InputStream ****************************************************/
/**
* Telnet Option: Logout
* This allows nice goodbye to time-outed or unwanted clients.
*/
protected static final int LOGOUT = 18;
/**
* Telnet Option: Linemode
*
* The infamous line mode option.
*/
protected static final int LINEMODE = 34;
protected static final int LM_MODE = 1;
protected static final int LM_EDIT = 1;
protected static final int LM_TRAPSIG = 2;
/**** Implementation of InputStream ****************************************************/
/****
* Following methods implement init/request/answer procedures for telnet
* protocol level communication.
*/
protected static final int LM_MODEACK = 4;
protected static final int LM_FORWARDMASK = 2;
protected static final int LM_SLC = 3;
protected static final int LM_SLC_NOSUPPORT = 0;
protected static final int LM_SLC_DEFAULT = 3;
/**** End telnet protocol level communication methods *******************************/
protected static final int LM_SLC_VALUE = 2;
/** Constants declaration ***********************************************/
//Telnet Protocoll Constants
protected static final int LM_SLC_CANTCHANGE = 1;
protected static final int LM_SLC_LEVELBITS = 3;
protected static final int LM_SLC_ACK = 128;
protected static final int LM_SLC_FLUSHIN = 64;
protected static final int LM_SLC_FLUSHOUT = 32;
protected static final int LM_SLC_SYNCH = 1;
protected static final int LM_SLC_BRK = 2;
protected static final int LM_SLC_IP = 3;
protected static final int LM_SLC_AO = 4;
protected static final int LM_SLC_AYT = 5;
protected static final int LM_SLC_EOR = 6;
/**
* The following implement the NVT (network virtual terminal) which offers the concept
* of a simple "printer". They are the basical meanings of control possibilities
* on a standard telnet implementation.
*/
protected static final int LM_SLC_ABORT = 7;
protected static final int LM_SLC_EOF = 8;
protected static final int LM_SLC_SUSP = 9;
/**
* Telnet Option: Environment
*/
protected static final int NEWENV = 39;
protected static final int NE_INFO = 2;
/**
* The following are constants for supported options,
* which can be negotiated based upon the telnet protocol
* specification.
*/
protected static final int NE_VAR = 0;
protected static final int NE_VALUE = 1;
/**
* The following options are options for which we also support subnegotiation
* based upon the telnet protocol specification.
*/
protected static final int NE_ESC = 2;
protected static final int NE_USERVAR = 3;
protected static final int NE_VAR_OK = 2;
protected static final int NE_VAR_DEFINED = 1;
protected static final int NE_VAR_DEFINED_EMPTY = 0;
protected static final int NE_VAR_UNDEFINED = -1;
protected static final int NE_IN_ERROR = -2;
protected static final int NE_IN_END = -3;
protected static final int NE_VAR_NAME_MAXLENGTH = 50;
protected static final int NE_VAR_VALUE_MAXLENGTH = 1000;
/**
* Unused
*/
protected static final int EXT_ASCII = 17; //Defines Extended ASCII
protected static final int SEND_LOC = 23; //Defines Send Location
protected static final int AUTHENTICATION = 37; //Defines Authentication
protected static final int ENCRYPT = 38; //Defines Encryption
private static final Logger LOG = Logger.getLogger(TelnetIO.class.getName());
/**
* Window Size Constants
*/
private static final int SMALLEST_BELIEVABLE_WIDTH = 20;
private static final int SMALLEST_BELIEVABLE_HEIGHT = 6;
private static final int DEFAULT_WIDTH = 80;
private static final int DEFAULT_HEIGHT = 25;
private Connection connection; //a reference to the connection this instance works for
private ConnectionData connectionData; //holds all important information of the connection
private DataOutputStream out; //the byte oriented outputstream
private DataInputStream in; //the byte oriented input stream
//Aggregations
private IACHandler iacHandler; //holds a reference to the aggregated IACHandler
//Members
private InetAddress localAddress; //address of the host the telnetd is running on
private boolean noIac = false; //describes if IAC was found and if its just processed
private boolean initializing;
private boolean crFlag;
/**
* Creates a TelnetIO object for the given connection.
* Input- and OutputStreams are properly set and the primary telnet
* protocol initialization is carried out by the inner IACHandler class.
*/
public TelnetIO() {
}//constructor
public void initIO() throws IOException {
//we make an instance of our inner class
iacHandler = new IACHandler();
//we setup underlying byte oriented streams
in = new DataInputStream(connectionData.getSocket().getInputStream());
out = new DataOutputStream(new BufferedOutputStream(connectionData.getSocket().getOutputStream()));
//we save the local address (necessary?)
localAddress = connectionData.getSocket().getLocalAddress();
crFlag = false;
//bootstrap telnet communication
initTelnetCommunication();
}//initIO
public void setConnection(Connection con) {
connection = con;
connectionData = connection.getConnectionData();
}//setConnection
/**
* Method to output a byte. Ensures that CR(\r) is never send
* alone,but CRLF(\r\n), which is a rule of the telnet protocol.
*
* @param b Byte to be written.
* @throws IOException if an error occurs
*/
public void write(byte b) throws IOException {
//ensure CRLF(\r\n) is written for LF(\n) to adhere
//to the telnet protocol.
if (!crFlag && b == 10) {
out.write(13);
}
out.write(b);
if (b == 13) {
crFlag = true;
} else {
crFlag = false;
}
}//write(byte)
/**
* Method to output an int.
*
* @param i Integer to be written.
* @throws IOException if an error occurs
*/
public void write(int i)
throws IOException {
write((byte) i);
}//write(int)
/**
* Method to write an array of bytes.
*
* @param sequence byte[] to be written.
* @throws IOException if an error occurs
*/
public void write(byte[] sequence) throws IOException {
for (byte b : sequence) {
write(b);
}
}//write(byte[])
/**
* Method to output an array of int' s.
*
* @param sequence int [] to write
* @throws IOException if an error occurs
*/
public void write(int[] sequence) throws IOException {
for (int i : sequence) {
write((byte) i);
}
}//write(int[])
/**
* Method to write a char.
*
* @param ch char to be written.
* @throws IOException if an error occurs
*/
public void write(char ch) throws IOException {
write((byte) ch);
}//write(char)
/**
* Method to output a string.
*
* @param str String to be written.
* @throws IOException if an error occurs
*/
public void write(String str) throws IOException {
write(str.getBytes());
}//write(String)
/**
* Method to flush all buffered output.
*
* @throws IOException if an error occurs
*/
public void flush() throws IOException {
out.flush();
}//flush
/**
* Method to close the underlying output stream to free system resources.
* Most likely only to be called by the ConnectionManager upon clean up of
* connections that ended or died.
*/
public void closeOutput() {
try {
//sends telnetprotocol logout acknowledgement
write(IAC);
write(DO);
write(LOGOUT);
//and now close underlying outputstream
out.close();
} catch (IOException ex) {
LOG.log(Level.SEVERE, "closeOutput()", ex);
//handle?
}
}//close
private void rawWrite(int i) throws IOException {
out.write(i);
}//rawWrite
/**
* Method to read a byte from the InputStream.
* Invokes the IACHandler upon IAC (Byte=255).
*
* @return int read from stream.
* @throws IOException if an error occurs
*/
public int read() throws IOException {
int c = rawread();
//if (c == 255) {
noIac = false;
while ((c == 255) && (!noIac)) {
/**
* Read next, and invoke
* the IACHandler he is taking care of the rest. Or at least he should :)
*/
c = rawread();
if (c != 255) {
iacHandler.handleC(c);
c = rawread();
} else {
noIac = true;
}
}
return stripCRSeq(c);
}//read
/**
* Method to close the underlying inputstream to free system resources.
* Most likely only to be called by the ConnectionManager upon clean up of
* connections that ended or died.
*/
public void closeInput() {
try {
in.close();
} catch (IOException e) {
//handle?
}
}//closeInput
/**
* This method reads an unsigned 16bit Integer from the stream,
* its here for getting the NAWS Data Values for height and width.
*
* @throws IOException if an error occurs
*/
private int read16int() throws IOException {
int c = in.readUnsignedShort();
return c;
}//read16int
/*
* The following options are options which might be of interest, but are not
* yet implemented or in use.
*/
/**
* Method to read a raw byte from the InputStream.
* Telnet protocol layer communication is filtered and processed here.
*
* @return int read from stream.
* @throws IOException if an error occurs
*/
private int rawread() throws IOException {
int b = 0;
//try {
b = in.readUnsignedByte();
connectionData.activity();
return b;
}//rawread
/**
* Checks for the telnet protocol specified CR followed by NULL or LF
* Subsequently reads for the next byte and forwards
* only a ENTER represented by LF internally.
*
* @throws IOException if an error occurs
*/
private int stripCRSeq(int input) throws IOException {
if (input == 13) {
rawread();
return 10;
}
return input;
}//stripCRSeq
/**
* Method that initializes the telnet communication layer.
*/
private void initTelnetCommunication() {
initializing = true;
try {
//start out, some clients just wait
if (connectionData.isLineMode()) {
iacHandler.doLineModeInit();
LOG.log(Level.FINE, "Line mode initialized.");
} else {
iacHandler.doCharacterModeInit();
LOG.log(Level.FINE, "Character mode initialized.");
}
//open for a defined timeout so we read incoming negotiation
connectionData.getSocket().setSoTimeout(1000);
read();
} catch (Exception e) {
//handle properly
//log.error("initTelnetCommunication()",e);
} finally {
//this is important, dont ask me why :)
try {
connectionData.getSocket().setSoTimeout(0);
} catch (Exception ex) {
LOG.log(Level.SEVERE, "initTelnetCommunication()", ex);
}
}
initializing = false;
}//initTelnetCommunication
/**
* Method that represents the answer to the
* AreYouThere question of the telnet protocol specification
*
* Output of the String [HostAdress:Yes]
*/
private void IamHere() {
try {
write("[" + localAddress.toString() + ":Yes]");
flush();
} catch (Exception ex) {
LOG.log(Level.SEVERE, "IamHere()", ex);
}
}//IamHere
/**
* Network virtual terminal break.
*/
private void nvtBreak() {
connection.processConnectionEvent(new ConnectionEvent(connection, ConnectionEvent.Type.CONNECTION_BREAK));
}//nvtBreak
/**
* Method that checks reported terminal sizes and sets the
* asserted values in the ConnectionData instance associated with
* the connection.
*
* @param width Integer that represents the Window width in chars
* @param height Integer that represents the Window height in chars
*/
private void setTerminalGeometry(int width, int height) {
if (width < SMALLEST_BELIEVABLE_WIDTH) {
width = DEFAULT_WIDTH;
}
if (height < SMALLEST_BELIEVABLE_HEIGHT) {
height = DEFAULT_HEIGHT;
}
//DEBUG: write("[New Window Size " + window_width + "x" + window_height + "]");
connectionData.setTerminalGeometry(width, height);
connection.processConnectionEvent(new ConnectionEvent(connection,
ConnectionEvent.Type.CONNECTION_TERMINAL_GEOMETRY_CHANGED));
}//setTerminalGeometry
public void setEcho(boolean b) {
}//setEcho
/**
* An inner class for handling incoming option negotiations implementing the telnet protocol
* specification based upon following Standards and RFCs:
*
* - 854 Telnet Protocol Specification
*
- 855 Telnet Option Specifications
*
- 857 Telnet Echo Option
*
- 858 Telnet Supress Go Ahead Option
*
- 727 Telnet Logout Option
*
- 1073 Telnet Window Size Option
*
- 1091 Telnet Terminal-Type Option
*
*
* Furthermore there are some more, which helped to solve problems, or might be important
* for future enhancements:
* 1143 The Q Method of Implementing Option Negotiation
* 1416 Telnet Authentication Option
*
*
* After an intense study of the available material (mainly cryptical written RFCs,
* a telnet client implementation for the macintosh based upon NCSA telnet, and a server side
* implementation called key, a mud-like system completely written in Java) I realized
* the problems we are facing regarding to the telnet protocol:
*
* - a minimal spread of invented options, which means there are a lot of invented options,
* but rarely they made it through to become a standard.
*
- Dependency on a special type of implementation is dangerous in our case.
* We are no kind of host that offers the user to run several processes at once,
* a BBS is intended to be a single process the user is interacting with.
*
- The LAMER has to be expected to log in with the standard Microsoft telnet
* implementation. This means forget every nice feature and most of the almost-standards.
*
*
* @author Dieter Wimberger
* @version 1.1 16/06/1998
*
*
* To-Do:
* - UNIX conform new style TTYPE negotiation. Setting a list and selecting from it...
*
*/
class IACHandler {
/**
* Telnet readin buffer
* Here its implemented guys. Open your eyes upon this solution.
* The others take a one byte solution :)
*/
private int[] buffer = new int[2];
/**
* DO_ECHO or not
*/
private boolean DO_ECHO = false;
/**
* DO_SUPGA or not
*/
private boolean DO_SUPGA = false;
/**
* DO_NAWS or not
*/
private boolean DO_NAWS = false;
/**
* DO_TTYPE or not
*/
private boolean DO_TTYPE = false;
/**
* DO_LINEMODE or not
*/
private boolean DO_LINEMODE = false;
/**
* DO_NEWENV or not
*/
private boolean DO_NEWENV = false;
/**
* Are we waiting for a DO reply?
*/
private boolean WAIT_DO_REPLY_SUPGA = false;
private boolean WAIT_DO_REPLY_ECHO = false;
private boolean WAIT_DO_REPLY_NAWS = false;
private boolean WAIT_DO_REPLY_TTYPE = false;
private boolean WAIT_DO_REPLY_LINEMODE = false;
private boolean WAIT_LM_MODE_ACK = false;
private boolean WAIT_LM_DO_REPLY_FORWARDMASK = false;
private boolean WAIT_DO_REPLY_NEWENV = false;
private boolean WAIT_NE_SEND_REPLY = false;
/**
* Are we waiting for a WILL reply?
*/
private boolean WAIT_WILL_REPLY_SUPGA = false;
private boolean WAIT_WILL_REPLY_ECHO = false;
private boolean WAIT_WILL_REPLY_NAWS = false;
private boolean WAIT_WILL_REPLY_TTYPE = false;
public void doCharacterModeInit() throws IOException {
sendCommand(WILL, ECHO, true);
sendCommand(DONT, ECHO, true); //necessary for some clients
sendCommand(DO, NAWS, true);
sendCommand(WILL, SUPGA, true);
sendCommand(DO, SUPGA, true);
sendCommand(DO, TTYPE, true);
sendCommand(DO, NEWENV, true); //environment variables
}//doCharacterModeInit
public void doLineModeInit() throws IOException {
sendCommand(DO, NAWS, true);
sendCommand(WILL, SUPGA, true);
sendCommand(DO, SUPGA, true);
sendCommand(DO, TTYPE, true);
sendCommand(DO, LINEMODE, true);
sendCommand(DO, NEWENV, true);
}//doLineModeInit
/**
* Method to handle a IAC that came in over the line.
*
* @param i (int)ed byte that followed the IAC
*/
public void handleC(int i) throws IOException {
buffer[0] = i;
if (!parseTWO(buffer)) {
buffer[1] = rawread();
parse(buffer);
}
buffer[0] = 0;
buffer[1] = 0;
}//handleC
/**
* Method that parses for options with two characters.
*
* @param buf int [] that represents the first byte that followed the IAC first.
* @return true when it was a two byte command (IAC OPTIONBYTE)
*/
private boolean parseTWO(int[] buf) {
switch (buf[0]) {
case IAC:
//doubled IAC to escape 255 is handled within the
//read method.
break;
case AYT:
IamHere();
break;
case AO:
case IP:
case EL:
case EC:
case NOP:
break;
case BRK:
nvtBreak();
break;
default:
return false;
}
return true;
}//parseTWO
/**
* Method that parses further on for options.
*
* @param buf that represents the first two bytes that followed the IAC.
*/
private void parse(int[] buf) throws IOException {
switch (buf[0]) {
/* First switch on the Negotiation Option */
case WILL:
if (supported(buf[1]) && isEnabled(buf[1])) {
;// do nothing
} else {
if (waitDOreply(buf[1]) && supported(buf[1])) {
enable(buf[1]);
setWait(DO, buf[1], false);
} else {
if (supported(buf[1])) {
sendCommand(DO, buf[1], false);
enable(buf[1]);
} else {
sendCommand(DONT, buf[1], false);
}
}
}
break;
case WONT:
if (waitDOreply(buf[1]) && supported(buf[1])) {
setWait(DO, buf[1], false);
} else {
if (supported(buf[1]) && isEnabled(buf[1])) {
// eanable() Method disables an Option that is already enabled
enable(buf[1]);
}
}
break;
case DO:
if (supported(buf[1]) && isEnabled(buf[1])) {
; // do nothing
} else {
if (waitWILLreply(buf[1]) && supported(buf[1])) {
enable(buf[1]);
setWait(WILL, buf[1], false);
} else {
if (supported(buf[1])) {
sendCommand(WILL, buf[1], false);
enable(buf[1]);
} else {
sendCommand(WONT, buf[1], false);
}
}
}
break;
case DONT:
if (waitWILLreply(buf[1]) && supported(buf[1])) {
setWait(WILL, buf[1], false);
} else {
if (supported(buf[1]) && isEnabled(buf[1])) {
// enable() Method disables an Option that is already enabled
enable(buf[1]);
}
}
break;
/* Now about other two byte IACs */
case DM: //How do I implement a SYNCH signal?
break;
case SB: //handle subnegotiations
if ((supported(buf[1])) && (isEnabled(buf[1]))) {
switch (buf[1]) {
case NAWS:
handleNAWS();
break;
case TTYPE:
handleTTYPE();
break;
case LINEMODE:
handleLINEMODE();
break;
case NEWENV:
handleNEWENV();
break;
default:
;
}
} else {
//do nothing
}
break;
default:
;
}//switch
}//parse
/**
* Method that reads a NawsSubnegotiation that ends up with a IAC SE
* If the measurements are unbelieveable it switches to the defaults.
*/
private void handleNAWS() throws IOException {
int width = read16int();
if (width == 255) {
width = read16int(); //handle doubled 255 value;
}
int height = read16int();
if (height == 255) {
height = read16int(); //handle doubled 255 value;
}
skipToSE();
setTerminalGeometry(width, height);
}//handleNAWS
/**
* Method that reads a TTYPE Subnegotiation String that ends up with a IAC SE
* If no Terminal is valid, we switch to the dumb "none" terminal.
*/
private void handleTTYPE() throws IOException {
String tmpstr = "";
// The next read should be 0 which is IS by the protocol
// specs. hmmm?
rawread(); //that should be the is :)
tmpstr = readIACSETerminatedString(40);
LOG.log(Level.FINE, "Reported terminal name " + tmpstr);
connectionData.setNegotiatedTerminalType(tmpstr);
}//handleTTYPE
/**
* Method that handles LINEMODE subnegotiation.
*/
public void handleLINEMODE() throws IOException {
int c = rawread();
switch (c) {
case LM_MODE:
handleLMMode();
break;
case LM_SLC:
handleLMSLC();
break;
case WONT:
case WILL:
handleLMForwardMask(c);
break;
default:
//skip to (including) SE
skipToSE();
}
}//handleLINEMODE
public void handleLMMode() throws IOException {
//we sent the default which no client might deny
//so we only wait the ACK
if (WAIT_LM_MODE_ACK) {
int mask = rawread();
if (mask != (LM_EDIT | LM_TRAPSIG | LM_MODEACK)) {
LOG.log(Level.FINE, "Client violates linemodeack sent: " + mask);
}
WAIT_LM_MODE_ACK = false;
}
skipToSE();
}//handleLMMode
public void handleLMSLC() throws IOException {
int[] triple = new int[3];
if (!readTriple(triple)) return;
//SLC will be initiated by the client
//case 1. client requests set
//LINEMODE SLC 0 SLC_DEFAULT 0
if ((triple[0] == 0) && (triple[1] == LM_SLC_DEFAULT) && (triple[2] == 0)) {
skipToSE();
//reply with SLC xxx SLC_DEFAULT 0
rawWrite(IAC);
rawWrite(SB);
rawWrite(LINEMODE);
rawWrite(LM_SLC);
//triples defaults for all
for (int i = 1; i < 12; i++) {
rawWrite(i);
rawWrite(LM_SLC_DEFAULT);
rawWrite(0);
}
rawWrite(IAC);
rawWrite(SE);
flush();
} else {
//case 2: just acknowledge anything we get from the client
rawWrite(IAC);
rawWrite(SB);
rawWrite(LINEMODE);
rawWrite(LM_SLC);
rawWrite(triple[0]);
rawWrite(triple[1] | LM_SLC_ACK);
rawWrite(triple[2]);
while (readTriple(triple)) {
rawWrite(triple[0]);
rawWrite(triple[1] | LM_SLC_ACK);
rawWrite(triple[2]);
}
rawWrite(IAC);
rawWrite(SE);
flush();
}
}//handleLMSLC
public void handleLMForwardMask(int WHAT) throws IOException {
switch (WHAT) {
case WONT:
if (WAIT_LM_DO_REPLY_FORWARDMASK) {
WAIT_LM_DO_REPLY_FORWARDMASK = false;
}
break;
}
skipToSE();
}//handleLMForward
public void handleNEWENV() throws IOException {
LOG.log(Level.FINE, "handleNEWENV()");
int c = rawread();
switch (c) {
case IS:
handleNEIs();
break;
case NE_INFO:
handleNEInfo();
break;
default:
//skip to (including) SE
skipToSE();
}
}//handleNEWENV
/*
The characters following a "type" up to the next "type" or VALUE specify the
variable name.
If a "type" is not followed by a VALUE
(e.g., by another VAR, USERVAR, or IAC SE) then that variable is
undefined.
*/
private int readNEVariableName(StringBuffer sbuf) throws IOException {
LOG.log(Level.FINE, "readNEVariableName()");
int i = -1;
do {
i = rawread();
if (i == -1) {
return NE_IN_ERROR;
} else if (i == IAC) {
i = rawread();
if (i == IAC) {
//duplicated IAC
sbuf.append((char) i);
} else if (i == SE) {
return NE_IN_END;
} else {
//Error should have been duplicated
return NE_IN_ERROR;
}
} else if (i == NE_ESC) {
i = rawread();
if (i == NE_ESC || i == NE_VAR || i == NE_USERVAR || i == NE_VALUE) {
sbuf.append((char) i);
} else {
return NE_IN_ERROR;
}
} else if (i == NE_VAR || i == NE_USERVAR) {
return NE_VAR_UNDEFINED;
} else if (i == NE_VALUE) {
return NE_VAR_DEFINED;
} else {
//check maximum length to prevent overflow
if (sbuf.length() >= NE_VAR_NAME_MAXLENGTH) {
//TODO: Log Overflow
return NE_IN_ERROR;
} else {
sbuf.append((char) i);
}
}
} while (true);
}//readNEVariableName
/*
The characters following a VALUE up to the next
"type" specify the value of the variable.
If a VALUE is immediately
followed by a "type" or IAC, then the variable is defined, but has
no value.
If an IAC is contained between the IS and the IAC SE,
it must be sent as IAC IAC.
*/
private int readNEVariableValue(StringBuffer sbuf) throws IOException {
LOG.log(Level.FINE, "readNEVariableValue()");
//check conditions for first character after VALUE
int i = rawread();
if (i == -1) {
return NE_IN_ERROR;
} else if (i == IAC) {
i = rawread();
if (i == IAC) {
//Double IAC
return NE_VAR_DEFINED_EMPTY;
} else if (i == SE) {
return NE_IN_END;
} else {
//according to rule IAC has to be duplicated
return NE_IN_ERROR;
}
} else if (i == NE_VAR || i == NE_USERVAR) {
return NE_VAR_DEFINED_EMPTY;
} else if (i == NE_ESC) {
//escaped value
i = rawread();
if (i == NE_ESC || i == NE_VAR || i == NE_USERVAR || i == NE_VALUE) {
sbuf.append((char) i);
} else {
return NE_IN_ERROR;
}
} else {
//character
sbuf.append((char) i);
}
//loop until end of value (IAC SE or TYPE)
do {
i = rawread();
if (i == -1) {
return NE_IN_ERROR;
} else if (i == IAC) {
i = rawread();
if (i == IAC) {
//duplicated IAC
sbuf.append((char) i);
} else if (i == SE) {
return NE_IN_END;
} else {
//Error should have been duplicated
return NE_IN_ERROR;
}
} else if (i == NE_ESC) {
i = rawread();
if (i == NE_ESC || i == NE_VAR || i == NE_USERVAR || i == NE_VALUE) {
sbuf.append((char) i);
} else {
return NE_IN_ERROR;
}
} else if (i == NE_VAR || i == NE_USERVAR) {
return NE_VAR_OK;
} else {
//check maximum length to prevent overflow
if (sbuf.length() > NE_VAR_VALUE_MAXLENGTH) {
//TODO: LOG Overflow
return NE_IN_ERROR;
} else {
sbuf.append((char) i);
}
}
} while (true);
}//readNEVariableValue
public void readNEVariables() throws IOException {
LOG.log(Level.FINE, "readNEVariables()");
StringBuffer sbuf = new StringBuffer(50);
int i = rawread();
if (i == IAC) {
//invalid or empty response
skipToSE();
LOG.log(Level.FINE, "readNEVariables()::INVALID VARIABLE");
return;
}
boolean cont = true;
if (i == NE_VAR || i == NE_USERVAR) {
do {
switch (readNEVariableName(sbuf)) {
case NE_IN_ERROR:
LOG.log(Level.FINE, "readNEVariables()::NE_IN_ERROR");
return;
case NE_IN_END:
LOG.log(Level.FINE, "readNEVariables()::NE_IN_END");
return;
case NE_VAR_DEFINED:
LOG.log(Level.FINE, "readNEVariables()::NE_VAR_DEFINED");
String str = sbuf.toString();
sbuf.delete(0, sbuf.length());
switch (readNEVariableValue(sbuf)) {
case NE_IN_ERROR:
LOG.log(Level.FINE, "readNEVariables()::NE_IN_ERROR");
return;
case NE_IN_END:
LOG.log(Level.FINE, "readNEVariables()::NE_IN_END");
return;
case NE_VAR_DEFINED_EMPTY:
LOG.log(Level.FINE, "readNEVariables()::NE_VAR_DEFINED_EMPTY");
break;
case NE_VAR_OK:
//add variable
LOG.log(Level.FINE, "readNEVariables()::NE_VAR_OK:VAR=" + str + " VAL=" + sbuf.toString());
TelnetIO.this.connectionData.getEnvironment().put(str, sbuf.toString());
sbuf.delete(0, sbuf.length());
break;
}
break;
case NE_VAR_UNDEFINED:
LOG.log(Level.FINE, "readNEVariables()::NE_VAR_UNDEFINED");
break;
}
} while (cont);
}
}//readVariables
public void handleNEIs() throws IOException {
LOG.log(Level.FINE, "handleNEIs()");
if (isEnabled(NEWENV)) {
readNEVariables();
}
}//handleNEIs
public void handleNEInfo() throws IOException {
LOG.log(Level.FINE, "handleNEInfo()");
if (isEnabled(NEWENV)) {
readNEVariables();
}
}//handleNEInfo
/**
* Method that sends a TTYPE Subnegotiation Request.
* IAC SB TERMINAL-TYPE SEND
*/
public void getTTYPE() throws IOException {
if (isEnabled(TTYPE)) {
rawWrite(IAC);
rawWrite(SB);
rawWrite(TTYPE);
rawWrite(SEND);
rawWrite(IAC);
rawWrite(SE);
flush();
}
}//getTTYPE
/**
* Method that sends a LINEMODE MODE Subnegotiation request.
* IAC LINEMODE MODE MASK SE
*/
public void negotiateLineMode() throws IOException {
if (isEnabled(LINEMODE)) {
rawWrite(IAC);
rawWrite(SB);
rawWrite(LINEMODE);
rawWrite(LM_MODE);
rawWrite(LM_EDIT | LM_TRAPSIG);
rawWrite(IAC);
rawWrite(SE);
WAIT_LM_MODE_ACK = true;
//dont forwardmask
rawWrite(IAC);
rawWrite(SB);
rawWrite(LINEMODE);
rawWrite(DONT);
rawWrite(LM_FORWARDMASK);
rawWrite(IAC);
rawWrite(SE);
WAIT_LM_DO_REPLY_FORWARDMASK = true;
flush();
}
}//negotiateLineMode
/**
* Method that sends a NEW-ENVIRON SEND subnegotiation request
* for default variables and user variables.
* IAC SB NEW-ENVIRON SEND VAR USERVAR IAC SE
*/
private void negotiateEnvironment() throws IOException {
//log.debug("negotiateEnvironment()");
if (isEnabled(NEWENV)) {
rawWrite(IAC);
rawWrite(SB);
rawWrite(NEWENV);
rawWrite(SEND);
rawWrite(NE_VAR);
rawWrite(NE_USERVAR);
rawWrite(IAC);
rawWrite(SE);
WAIT_NE_SEND_REPLY = true;
flush();
}
}//negotiateEnvironment
/**
* Method that skips a subnegotiation response.
*/
private void skipToSE() throws IOException {
while (rawread() != SE) ;
}//skipSubnegotiation
private boolean readTriple(int[] triple) throws IOException {
triple[0] = rawread();
triple[1] = rawread();
if ((triple[0] == IAC) && (triple[1] == SE)) {
return false;
} else {
triple[2] = rawread();
return true;
}
}//readTriple
/**
* Method that reads a subnegotiation String,
* one of those that end with a IAC SE combination.
* A maximum length is observed to prevent overflow.
*
* @return IAC SE terminated String
*/
private String readIACSETerminatedString(int maxlength) throws IOException {
int where = 0;
char[] cbuf = new char[maxlength];
char b = ' ';
boolean cont = true;
do {
int i;
i = rawread();
switch (i) {
case IAC:
i = rawread();
if (i == SE) {
cont = false;
}
break;
case -1:
return (new String("default"));
default:
}
if (cont) {
b = (char) i;
//Fix for overflow wimpi (10/06/2004)
if (b == '\n' || b == '\r' || where == maxlength) {
cont = false;
} else {
cbuf[where++] = b;
}
}
} while (cont);
return (new String(cbuf, 0, where));
}//readIACSETerminatedString
/**
* Method that informs internally about the supported Negotiation Options
*
* @param i int that represents requested the Option
* @return Boolean that represents support status
*/
private boolean supported(int i) {
switch (i) {
case SUPGA:
case ECHO:
case NAWS:
case TTYPE:
case NEWENV:
return true;
case LINEMODE:
return connectionData.isLineMode();
default:
return false;
}
}//supported
/**
* Method that sends a Telnet IAC String with TelnetIO.write(byte b) method.
*
* @param i int that represents requested Command Type (DO,DONT,WILL,WONT)
* @param j int that represents the Option itself (e.g. ECHO, NAWS)
*/
private void sendCommand(int i, int j, boolean westarted) throws IOException {
rawWrite(IAC);
rawWrite(i);
rawWrite(j);
// we started with DO OPTION and now wait for reply
if ((i == DO) && westarted) setWait(DO, j, true);
// we started with WILL OPTION and now wait for reply
if ((i == WILL) && westarted) setWait(WILL, j, true);
flush();
}//sendCommand
/**
* Method enables or disables a supported Option
*
* @param i int that represents the Option
*/
private void enable(int i) throws IOException {
switch (i) {
case SUPGA:
if (DO_SUPGA) {
DO_SUPGA = false;
} else {
DO_SUPGA = true;
}
break;
case ECHO:
if (DO_ECHO) {
DO_ECHO = false;
} else {
DO_ECHO = true;
}
break;
case NAWS:
if (DO_NAWS) {
DO_NAWS = false;
} else {
DO_NAWS = true;
}
break;
case TTYPE:
if (DO_TTYPE) {
DO_TTYPE = false;
} else {
DO_TTYPE = true;
getTTYPE();
}
break;
case LINEMODE:
if (DO_LINEMODE) {
DO_LINEMODE = false;
//set false in connection data, so the application knows.
connectionData.setLineMode(false);
} else {
DO_LINEMODE = true;
negotiateLineMode();
}
break;
case NEWENV:
if (DO_NEWENV) {
DO_NEWENV = false;
} else {
DO_NEWENV = true;
negotiateEnvironment();
}
break;
}
}//enable
/**
* Method that informs internally about the status of the supported
* Negotiation Options.
*
* @param i int that represents requested the Option
* @return Boolean that represents the enabled status
*/
private boolean isEnabled(int i) {
switch (i) {
case SUPGA:
return DO_SUPGA;
case ECHO:
return DO_ECHO;
case NAWS:
return DO_NAWS;
case TTYPE:
return DO_TTYPE;
case LINEMODE:
return DO_LINEMODE;
case NEWENV:
return DO_NEWENV;
default:
return false;
}
}//isEnabled
/**
* Method that informs internally about the WILL wait status
* of an option.
*
* @param i that represents requested the Option
* @return Boolean that represents WILL wait status of the Option
*/
private boolean waitWILLreply(int i) {
switch (i) {
case SUPGA:
return WAIT_WILL_REPLY_SUPGA;
case ECHO:
return WAIT_WILL_REPLY_ECHO;
case NAWS:
return WAIT_WILL_REPLY_NAWS;
case TTYPE:
return WAIT_WILL_REPLY_TTYPE;
default:
return false;
}
}//waitWILLreply
/**
* Method that informs internally about the DO wait status
* of an option.
*
* @param i Integer that represents requested the Option
* @return Boolean that represents DO wait status of the Option
*/
private boolean waitDOreply(int i) {
switch (i) {
case SUPGA:
return WAIT_DO_REPLY_SUPGA;
case ECHO:
return WAIT_DO_REPLY_ECHO;
case NAWS:
return WAIT_DO_REPLY_NAWS;
case TTYPE:
return WAIT_DO_REPLY_TTYPE;
case LINEMODE:
return WAIT_DO_REPLY_LINEMODE;
case NEWENV:
return WAIT_DO_REPLY_NEWENV;
default:
return false;
}
}//waitDOreply
/**
* Method that mutates the wait status of an option in
* negotiation. We need the wait status to keep track of
* negotiation in process. So we cant miss if we started out
* or the other and so on.
*
* @param WHAT Integer values of DO or WILL
* @param OPTION Integer that represents the Option
* @param WAIT Boolean that represents the status of wait that should be set
*/
private void setWait(int WHAT, int OPTION, boolean WAIT) {
switch (WHAT) {
case DO:
switch (OPTION) {
case SUPGA:
WAIT_DO_REPLY_SUPGA = WAIT;
break;
case ECHO:
WAIT_DO_REPLY_ECHO = WAIT;
break;
case NAWS:
WAIT_DO_REPLY_NAWS = WAIT;
break;
case TTYPE:
WAIT_DO_REPLY_TTYPE = WAIT;
break;
case LINEMODE:
WAIT_DO_REPLY_LINEMODE = WAIT;
break;
case NEWENV:
WAIT_DO_REPLY_NEWENV = WAIT;
break;
}
break;
case WILL:
switch (OPTION) {
case SUPGA:
WAIT_WILL_REPLY_SUPGA = WAIT;
break;
case ECHO:
WAIT_WILL_REPLY_ECHO = WAIT;
break;
case NAWS:
WAIT_WILL_REPLY_NAWS = WAIT;
break;
case TTYPE:
WAIT_WILL_REPLY_TTYPE = WAIT;
break;
}
break;
}
}//setWait
}//inner class IACHandler
/** end Constants declaration **************************************************/
}//class TelnetIO