Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.commons.net.telnet; import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.OutputStream; import java.io.IOException; import java.util.Arrays; import org.apache.commons.net.SocketClient; /** * @author Bruno D'Avanzo */ class Telnet extends SocketClient { static final boolean debug = /*true;*/ false; static final boolean debugoptions = /*true;*/ false; static final byte[] _COMMAND_DO = { (byte) TelnetCommand.IAC, (byte) TelnetCommand.DO }; static final byte[] _COMMAND_DONT = { (byte) TelnetCommand.IAC, (byte) TelnetCommand.DONT }; static final byte[] _COMMAND_WILL = { (byte) TelnetCommand.IAC, (byte) TelnetCommand.WILL }; static final byte[] _COMMAND_WONT = { (byte) TelnetCommand.IAC, (byte) TelnetCommand.WONT }; static final byte[] _COMMAND_SB = { (byte) TelnetCommand.IAC, (byte) TelnetCommand.SB }; static final byte[] _COMMAND_SE = { (byte) TelnetCommand.IAC, (byte) TelnetCommand.SE }; static final int _WILL_MASK = 0x01, _DO_MASK = 0x02, _REQUESTED_WILL_MASK = 0x04, _REQUESTED_DO_MASK = 0x08; /* public */ static final int DEFAULT_PORT = 23; int[] _doResponse, _willResponse, _options; /* TERMINAL-TYPE option (start)*/ /*** * Terminal type option ***/ protected static final int TERMINAL_TYPE = 24; /*** * Send (for subnegotiation) ***/ protected static final int TERMINAL_TYPE_SEND = 1; /*** * Is (for subnegotiation) ***/ protected static final int TERMINAL_TYPE_IS = 0; /*** * Is sequence (for subnegotiation) ***/ static final byte[] _COMMAND_IS = { (byte) TERMINAL_TYPE, (byte) TERMINAL_TYPE_IS }; /*** * Terminal type ***/ private String terminalType = null; /* TERMINAL-TYPE option (end)*/ /* open TelnetOptionHandler functionality (start)*/ /*** * Array of option handlers ***/ private final TelnetOptionHandler optionHandlers[]; /* open TelnetOptionHandler functionality (end)*/ /* Code Section added for supporting AYT (start)*/ /*** * AYT sequence ***/ static final byte[] _COMMAND_AYT = { (byte) TelnetCommand.IAC, (byte) TelnetCommand.AYT }; /*** * monitor to wait for AYT ***/ private final Object aytMonitor = new Object(); /*** * flag for AYT ***/ private volatile boolean aytFlag = true; /* Code Section added for supporting AYT (end)*/ /*** * The stream on which to spy ***/ private volatile OutputStream spyStream = null; /*** * The notification handler ***/ private TelnetNotificationHandler __notifhand = null; /*** * Empty Constructor ***/ Telnet() { setDefaultPort(DEFAULT_PORT); _doResponse = new int[TelnetOption.MAX_OPTION_VALUE + 1]; _willResponse = new int[TelnetOption.MAX_OPTION_VALUE + 1]; _options = new int[TelnetOption.MAX_OPTION_VALUE + 1]; optionHandlers = new TelnetOptionHandler[TelnetOption.MAX_OPTION_VALUE + 1]; } /* TERMINAL-TYPE option (start)*/ /*** * This constructor lets you specify the terminal type. * <p> * @param termtype - terminal type to be negotiated (ej. VT100) ***/ Telnet(String termtype) { setDefaultPort(DEFAULT_PORT); _doResponse = new int[TelnetOption.MAX_OPTION_VALUE + 1]; _willResponse = new int[TelnetOption.MAX_OPTION_VALUE + 1]; _options = new int[TelnetOption.MAX_OPTION_VALUE + 1]; terminalType = termtype; optionHandlers = new TelnetOptionHandler[TelnetOption.MAX_OPTION_VALUE + 1]; } /* TERMINAL-TYPE option (end)*/ /*** * Looks for the state of the option. * <p> * @return returns true if a will has been acknowledged * <p> * @param option - option code to be looked up. ***/ boolean _stateIsWill(int option) { return ((_options[option] & _WILL_MASK) != 0); } /*** * Looks for the state of the option. * <p> * @return returns true if a wont has been acknowledged * <p> * @param option - option code to be looked up. ***/ boolean _stateIsWont(int option) { return !_stateIsWill(option); } /*** * Looks for the state of the option. * <p> * @return returns true if a do has been acknowledged * <p> * @param option - option code to be looked up. ***/ boolean _stateIsDo(int option) { return ((_options[option] & _DO_MASK) != 0); } /*** * Looks for the state of the option. * <p> * @return returns true if a dont has been acknowledged * <p> * @param option - option code to be looked up. ***/ boolean _stateIsDont(int option) { return !_stateIsDo(option); } /*** * Looks for the state of the option. * <p> * @return returns true if a will has been reuqested * <p> * @param option - option code to be looked up. ***/ boolean _requestedWill(int option) { return ((_options[option] & _REQUESTED_WILL_MASK) != 0); } /*** * Looks for the state of the option. * <p> * @return returns true if a wont has been reuqested * <p> * @param option - option code to be looked up. ***/ boolean _requestedWont(int option) { return !_requestedWill(option); } /*** * Looks for the state of the option. * <p> * @return returns true if a do has been reuqested * <p> * @param option - option code to be looked up. ***/ boolean _requestedDo(int option) { return ((_options[option] & _REQUESTED_DO_MASK) != 0); } /*** * Looks for the state of the option. * <p> * @return returns true if a dont has been reuqested * <p> * @param option - option code to be looked up. ***/ boolean _requestedDont(int option) { return !_requestedDo(option); } /*** * Sets the state of the option. * <p> * @param option - option code to be set. * @throws IOException ***/ void _setWill(int option) throws IOException { _options[option] |= _WILL_MASK; /* open TelnetOptionHandler functionality (start)*/ if (_requestedWill(option)) { if (optionHandlers[option] != null) { optionHandlers[option].setWill(true); int subneg[] = optionHandlers[option].startSubnegotiationLocal(); if (subneg != null) { _sendSubnegotiation(subneg); } } } /* open TelnetOptionHandler functionality (end)*/ } /*** * Sets the state of the option. * <p> * @param option - option code to be set. * @throws IOException ***/ void _setDo(int option) throws IOException { _options[option] |= _DO_MASK; /* open TelnetOptionHandler functionality (start)*/ if (_requestedDo(option)) { if (optionHandlers[option] != null) { optionHandlers[option].setDo(true); int subneg[] = optionHandlers[option].startSubnegotiationRemote(); if (subneg != null) { _sendSubnegotiation(subneg); } } } /* open TelnetOptionHandler functionality (end)*/ } /*** * Sets the state of the option. * <p> * @param option - option code to be set. ***/ void _setWantWill(int option) { _options[option] |= _REQUESTED_WILL_MASK; } /*** * Sets the state of the option. * <p> * @param option - option code to be set. ***/ void _setWantDo(int option) { _options[option] |= _REQUESTED_DO_MASK; } /*** * Sets the state of the option. * <p> * @param option - option code to be set. ***/ void _setWont(int option) { _options[option] &= ~_WILL_MASK; /* open TelnetOptionHandler functionality (start)*/ if (optionHandlers[option] != null) { optionHandlers[option].setWill(false); } /* open TelnetOptionHandler functionality (end)*/ } /*** * Sets the state of the option. * <p> * @param option - option code to be set. ***/ void _setDont(int option) { _options[option] &= ~_DO_MASK; /* open TelnetOptionHandler functionality (start)*/ if (optionHandlers[option] != null) { optionHandlers[option].setDo(false); } /* open TelnetOptionHandler functionality (end)*/ } /*** * Sets the state of the option. * <p> * @param option - option code to be set. ***/ void _setWantWont(int option) { _options[option] &= ~_REQUESTED_WILL_MASK; } /*** * Sets the state of the option. * <p> * @param option - option code to be set. ***/ void _setWantDont(int option) { _options[option] &= ~_REQUESTED_DO_MASK; } /** * Processes a COMMAND. * * @param command - option code to be set. **/ void _processCommand(int command) { if (debugoptions) { System.err.println("RECEIVED COMMAND: " + command); } if (__notifhand != null) { __notifhand.receivedNegotiation(TelnetNotificationHandler.RECEIVED_COMMAND, command); } } /** * Processes a DO request. * * @param option - option code to be set. * @throws IOException - Exception in I/O. **/ void _processDo(int option) throws IOException { if (debugoptions) { System.err.println("RECEIVED DO: " + TelnetOption.getOption(option)); } if (__notifhand != null) { __notifhand.receivedNegotiation(TelnetNotificationHandler.RECEIVED_DO, option); } boolean acceptNewState = false; /* open TelnetOptionHandler functionality (start)*/ if (optionHandlers[option] != null) { acceptNewState = optionHandlers[option].getAcceptLocal(); } else { /* open TelnetOptionHandler functionality (end)*/ /* TERMINAL-TYPE option (start)*/ if (option == TERMINAL_TYPE) { if ((terminalType != null) && (terminalType.length() > 0)) { acceptNewState = true; } } /* TERMINAL-TYPE option (end)*/ /* open TelnetOptionHandler functionality (start)*/ } /* open TelnetOptionHandler functionality (end)*/ if (_willResponse[option] > 0) { --_willResponse[option]; if (_willResponse[option] > 0 && _stateIsWill(option)) { --_willResponse[option]; } } if (_willResponse[option] == 0) { if (_requestedWont(option)) { switch (option) { default: break; } if (acceptNewState) { _setWantWill(option); _sendWill(option); } else { ++_willResponse[option]; _sendWont(option); } } else { // Other end has acknowledged option. switch (option) { default: break; } } } _setWill(option); } /** * Processes a DONT request. * * @param option - option code to be set. * @throws IOException - Exception in I/O. **/ void _processDont(int option) throws IOException { if (debugoptions) { System.err.println("RECEIVED DONT: " + TelnetOption.getOption(option)); } if (__notifhand != null) { __notifhand.receivedNegotiation(TelnetNotificationHandler.RECEIVED_DONT, option); } if (_willResponse[option] > 0) { --_willResponse[option]; if (_willResponse[option] > 0 && _stateIsWont(option)) { --_willResponse[option]; } } if (_willResponse[option] == 0 && _requestedWill(option)) { switch (option) { default: break; } /* FIX for a BUG in the negotiation (start)*/ if ((_stateIsWill(option)) || (_requestedWill(option))) { _sendWont(option); } _setWantWont(option); /* FIX for a BUG in the negotiation (end)*/ } _setWont(option); } /** * Processes a WILL request. * * @param option - option code to be set. * @throws IOException - Exception in I/O. **/ void _processWill(int option) throws IOException { if (debugoptions) { System.err.println("RECEIVED WILL: " + TelnetOption.getOption(option)); } if (__notifhand != null) { __notifhand.receivedNegotiation(TelnetNotificationHandler.RECEIVED_WILL, option); } boolean acceptNewState = false; /* open TelnetOptionHandler functionality (start)*/ if (optionHandlers[option] != null) { acceptNewState = optionHandlers[option].getAcceptRemote(); } /* open TelnetOptionHandler functionality (end)*/ if (_doResponse[option] > 0) { --_doResponse[option]; if (_doResponse[option] > 0 && _stateIsDo(option)) { --_doResponse[option]; } } if (_doResponse[option] == 0 && _requestedDont(option)) { switch (option) { default: break; } if (acceptNewState) { _setWantDo(option); _sendDo(option); } else { ++_doResponse[option]; _sendDont(option); } } _setDo(option); } /** * Processes a WONT request. * * @param option - option code to be set. * @throws IOException - Exception in I/O. **/ void _processWont(int option) throws IOException { if (debugoptions) { System.err.println("RECEIVED WONT: " + TelnetOption.getOption(option)); } if (__notifhand != null) { __notifhand.receivedNegotiation(TelnetNotificationHandler.RECEIVED_WONT, option); } if (_doResponse[option] > 0) { --_doResponse[option]; if (_doResponse[option] > 0 && _stateIsDont(option)) { --_doResponse[option]; } } if (_doResponse[option] == 0 && _requestedDo(option)) { switch (option) { default: break; } /* FIX for a BUG in the negotiation (start)*/ if ((_stateIsDo(option)) || (_requestedDo(option))) { _sendDont(option); } _setWantDont(option); /* FIX for a BUG in the negotiation (end)*/ } _setDont(option); } /* TERMINAL-TYPE option (start)*/ /** * Processes a suboption negotiation. * * @param suboption - subnegotiation data received * @param suboptionLength - length of data received * @throws IOException - Exception in I/O. **/ void _processSuboption(int suboption[], int suboptionLength) throws IOException { if (debug) { System.err.println("PROCESS SUBOPTION."); } /* open TelnetOptionHandler functionality (start)*/ if (suboptionLength > 0) { if (optionHandlers[suboption[0]] != null) { int responseSuboption[] = optionHandlers[suboption[0]].answerSubnegotiation(suboption, suboptionLength); _sendSubnegotiation(responseSuboption); } else { if (suboptionLength > 1) { if (debug) { for (int ii = 0; ii < suboptionLength; ii++) { System.err.println("SUB[" + ii + "]: " + suboption[ii]); } } if ((suboption[0] == TERMINAL_TYPE) && (suboption[1] == TERMINAL_TYPE_SEND)) { _sendTerminalType(); } } } } /* open TelnetOptionHandler functionality (end)*/ } /*** * Sends terminal type information. * <p> * @throws IOException - Exception in I/O. ***/ final synchronized void _sendTerminalType() throws IOException { if (debug) { System.err.println("SEND TERMINAL-TYPE: " + terminalType); } if (terminalType != null) { _output_.write(_COMMAND_SB); _output_.write(_COMMAND_IS); _output_.write(terminalType.getBytes(getCharsetName())); // Java 1.6 can use getCharset() _output_.write(_COMMAND_SE); _output_.flush(); } } /* TERMINAL-TYPE option (end)*/ /* open TelnetOptionHandler functionality (start)*/ /** * Manages subnegotiation for Terminal Type. * * @param subn - subnegotiation data to be sent * @throws IOException - Exception in I/O. **/ final synchronized void _sendSubnegotiation(int subn[]) throws IOException { if (debug) { System.err.println("SEND SUBNEGOTIATION: "); if (subn != null) { System.err.println(Arrays.toString(subn)); } } if (subn != null) { _output_.write(_COMMAND_SB); // Note _output_ is buffered, so might as well simplify by writing single bytes for (int element : subn) { byte b = (byte) element; if (b == (byte) TelnetCommand.IAC) { // cast is necessary because IAC is outside the signed byte range _output_.write(b); // double any IAC bytes } _output_.write(b); } _output_.write(_COMMAND_SE); /* Code Section added for sending the negotiation ASAP (start)*/ _output_.flush(); /* Code Section added for sending the negotiation ASAP (end)*/ } } /* open TelnetOptionHandler functionality (end)*/ /** * Sends a command, automatically adds IAC prefix and flushes the output. * * @param cmd - command data to be sent * @throws IOException - Exception in I/O. * @since 3.0 */ final synchronized void _sendCommand(byte cmd) throws IOException { _output_.write(TelnetCommand.IAC); _output_.write(cmd); _output_.flush(); } /* Code Section added for supporting AYT (start)*/ /*** * Processes the response of an AYT ***/ final synchronized void _processAYTResponse() { if (!aytFlag) { synchronized (aytMonitor) { aytFlag = true; aytMonitor.notifyAll(); } } } /* Code Section added for supporting AYT (end)*/ /*** * Called upon connection. * <p> * @throws IOException - Exception in I/O. ***/ @Override protected void _connectAction_() throws IOException { /* (start). BUGFIX: clean the option info for each connection*/ for (int ii = 0; ii < TelnetOption.MAX_OPTION_VALUE + 1; ii++) { _doResponse[ii] = 0; _willResponse[ii] = 0; _options[ii] = 0; if (optionHandlers[ii] != null) { optionHandlers[ii].setDo(false); optionHandlers[ii].setWill(false); } } /* (end). BUGFIX: clean the option info for each connection*/ super._connectAction_(); _input_ = new BufferedInputStream(_input_); _output_ = new BufferedOutputStream(_output_); /* open TelnetOptionHandler functionality (start)*/ for (int ii = 0; ii < TelnetOption.MAX_OPTION_VALUE + 1; ii++) { if (optionHandlers[ii] != null) { if (optionHandlers[ii].getInitLocal()) { _requestWill(optionHandlers[ii].getOptionCode()); } if (optionHandlers[ii].getInitRemote()) { _requestDo(optionHandlers[ii].getOptionCode()); } } } /* open TelnetOptionHandler functionality (end)*/ } /** * Sends a DO. * * @param option - Option code. * @throws IOException - Exception in I/O. **/ final synchronized void _sendDo(int option) throws IOException { if (debug || debugoptions) { System.err.println("DO: " + TelnetOption.getOption(option)); } _output_.write(_COMMAND_DO); _output_.write(option); /* Code Section added for sending the negotiation ASAP (start)*/ _output_.flush(); /* Code Section added for sending the negotiation ASAP (end)*/ } /** * Requests a DO. * * @param option - Option code. * @throws IOException - Exception in I/O. **/ final synchronized void _requestDo(int option) throws IOException { if ((_doResponse[option] == 0 && _stateIsDo(option)) || _requestedDo(option)) { return; } _setWantDo(option); ++_doResponse[option]; _sendDo(option); } /** * Sends a DONT. * * @param option - Option code. * @throws IOException - Exception in I/O. **/ final synchronized void _sendDont(int option) throws IOException { if (debug || debugoptions) { System.err.println("DONT: " + TelnetOption.getOption(option)); } _output_.write(_COMMAND_DONT); _output_.write(option); /* Code Section added for sending the negotiation ASAP (start)*/ _output_.flush(); /* Code Section added for sending the negotiation ASAP (end)*/ } /** * Requests a DONT. * * @param option - Option code. * @throws IOException - Exception in I/O. **/ final synchronized void _requestDont(int option) throws IOException { if ((_doResponse[option] == 0 && _stateIsDont(option)) || _requestedDont(option)) { return; } _setWantDont(option); ++_doResponse[option]; _sendDont(option); } /** * Sends a WILL. * * @param option - Option code. * @throws IOException - Exception in I/O. **/ final synchronized void _sendWill(int option) throws IOException { if (debug || debugoptions) { System.err.println("WILL: " + TelnetOption.getOption(option)); } _output_.write(_COMMAND_WILL); _output_.write(option); /* Code Section added for sending the negotiation ASAP (start)*/ _output_.flush(); /* Code Section added for sending the negotiation ASAP (end)*/ } /** * Requests a WILL. * * @param option - Option code. * @throws IOException - Exception in I/O. **/ final synchronized void _requestWill(int option) throws IOException { if ((_willResponse[option] == 0 && _stateIsWill(option)) || _requestedWill(option)) { return; } _setWantWill(option); ++_doResponse[option]; _sendWill(option); } /** * Sends a WONT. * * @param option - Option code. * @throws IOException - Exception in I/O. **/ final synchronized void _sendWont(int option) throws IOException { if (debug || debugoptions) { System.err.println("WONT: " + TelnetOption.getOption(option)); } _output_.write(_COMMAND_WONT); _output_.write(option); /* Code Section added for sending the negotiation ASAP (start)*/ _output_.flush(); /* Code Section added for sending the negotiation ASAP (end)*/ } /** * Requests a WONT. * * @param option - Option code. * @throws IOException - Exception in I/O. **/ final synchronized void _requestWont(int option) throws IOException { if ((_willResponse[option] == 0 && _stateIsWont(option)) || _requestedWont(option)) { return; } _setWantWont(option); ++_doResponse[option]; _sendWont(option); } /** * Sends a byte. * * @param b - byte to send * @throws IOException - Exception in I/O. **/ final synchronized void _sendByte(int b) throws IOException { _output_.write(b); /* Code Section added for supporting spystreams (start)*/ _spyWrite(b); /* Code Section added for supporting spystreams (end)*/ } /* Code Section added for supporting AYT (start)*/ /** * Sends an Are You There sequence and waits for the result. * * @param timeout - Time to wait for a response (millis.) * @throws IOException - Exception in I/O. * @throws IllegalArgumentException - Illegal argument * @throws InterruptedException - Interrupted during wait. * @return true if AYT received a response, false otherwise **/ final boolean _sendAYT(long timeout) throws IOException, IllegalArgumentException, InterruptedException { boolean retValue = false; synchronized (aytMonitor) { synchronized (this) { aytFlag = false; _output_.write(_COMMAND_AYT); _output_.flush(); } aytMonitor.wait(timeout); if (aytFlag == false) { retValue = false; aytFlag = true; } else { retValue = true; } } return (retValue); } /* Code Section added for supporting AYT (end)*/ /* open TelnetOptionHandler functionality (start)*/ /** * Registers a new TelnetOptionHandler for this telnet to use. * * @param opthand - option handler to be registered. * @throws InvalidTelnetOptionException - The option code is invalid. * @throws IOException **/ void addOptionHandler(TelnetOptionHandler opthand) throws InvalidTelnetOptionException, IOException { int optcode = opthand.getOptionCode(); if (TelnetOption.isValidOption(optcode)) { if (optionHandlers[optcode] == null) { optionHandlers[optcode] = opthand; if (isConnected()) { if (opthand.getInitLocal()) { _requestWill(optcode); } if (opthand.getInitRemote()) { _requestDo(optcode); } } } else { throw (new InvalidTelnetOptionException("Already registered option", optcode)); } } else { throw (new InvalidTelnetOptionException("Invalid Option Code", optcode)); } } /** * Unregisters a TelnetOptionHandler. * * @param optcode - Code of the option to be unregistered. * @throws InvalidTelnetOptionException - The option code is invalid. * @throws IOException **/ void deleteOptionHandler(int optcode) throws InvalidTelnetOptionException, IOException { if (TelnetOption.isValidOption(optcode)) { if (optionHandlers[optcode] == null) { throw (new InvalidTelnetOptionException("Unregistered option", optcode)); } else { TelnetOptionHandler opthand = optionHandlers[optcode]; optionHandlers[optcode] = null; if (opthand.getWill()) { _requestWont(optcode); } if (opthand.getDo()) { _requestDont(optcode); } } } else { throw (new InvalidTelnetOptionException("Invalid Option Code", optcode)); } } /* open TelnetOptionHandler functionality (end)*/ /* Code Section added for supporting spystreams (start)*/ /*** * Registers an OutputStream for spying what's going on in * the Telnet session. * <p> * @param spystream - OutputStream on which session activity * will be echoed. ***/ void _registerSpyStream(OutputStream spystream) { spyStream = spystream; } /*** * Stops spying this Telnet. * <p> ***/ void _stopSpyStream() { spyStream = null; } /*** * Sends a read char on the spy stream. * <p> * @param ch - character read from the session ***/ void _spyRead(int ch) { OutputStream spy = spyStream; if (spy != null) { try { if (ch != '\r') { spy.write(ch); if (ch == '\n') { spy.write('\r'); } spy.flush(); } } catch (IOException e) { spyStream = null; } } } /*** * Sends a written char on the spy stream. * <p> * @param ch - character written to the session ***/ void _spyWrite(int ch) { if (!(_stateIsDo(TelnetOption.ECHO) && _requestedDo(TelnetOption.ECHO))) { OutputStream spy = spyStream; if (spy != null) { try { spy.write(ch); spy.flush(); } catch (IOException e) { spyStream = null; } } } } /* Code Section added for supporting spystreams (end)*/ /*** * Registers a notification handler to which will be sent * notifications of received telnet option negotiation commands. * <p> * @param notifhand - TelnetNotificationHandler to be registered ***/ public void registerNotifHandler(TelnetNotificationHandler notifhand) { __notifhand = notifhand; } /*** * Unregisters the current notification handler. * <p> ***/ public void unregisterNotifHandler() { __notifhand = null; } }