001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.net.telnet;
019
020/**
021 * Implements the telnet terminal type option RFC 1091.
022 */
023public class TerminalTypeOptionHandler extends TelnetOptionHandler {
024    /**
025     * Terminal type option
026     */
027    protected static final int TERMINAL_TYPE = 24;
028
029    /**
030     * Send (for subnegotiation)
031     */
032    protected static final int TERMINAL_TYPE_SEND = 1;
033
034    /**
035     * Is (for subnegotiation)
036     */
037    protected static final int TERMINAL_TYPE_IS = 0;
038
039    /**
040     * Terminal type
041     */
042    private final String termType;
043
044    /**
045     * Constructor for the TerminalTypeOptionHandler. Initial and accept behavior flags are set to false
046     * <p>
047     *
048     * @param termtype - terminal type that will be negotiated.
049     */
050    public TerminalTypeOptionHandler(final String termtype) {
051        super(TelnetOption.TERMINAL_TYPE, false, false, false, false);
052        termType = termtype;
053    }
054
055    /**
056     * Constructor for the TerminalTypeOptionHandler. Allows defining desired initial setting for local/remote activation of this option and behavior in case a
057     * local/remote activation request for this option is received.
058     * <p>
059     *
060     * @param termtype     - terminal type that will be negotiated.
061     * @param initlocal    - if set to true, a WILL is sent upon connection.
062     * @param initremote   - if set to true, a DO is sent upon connection.
063     * @param acceptlocal  - if set to true, any DO request is accepted.
064     * @param acceptremote - if set to true, any WILL request is accepted.
065     */
066    public TerminalTypeOptionHandler(final String termtype, final boolean initlocal, final boolean initremote, final boolean acceptlocal,
067            final boolean acceptremote) {
068        super(TelnetOption.TERMINAL_TYPE, initlocal, initremote, acceptlocal, acceptremote);
069        termType = termtype;
070    }
071
072    /**
073     * Implements the abstract method of TelnetOptionHandler.
074     * <p>
075     *
076     * @param suboptionData   - the sequence received, without IAC SB &amp; IAC SE
077     * @param suboptionLength - the length of data in suboption_data
078     *                        <p>
079     * @return terminal type information
080     */
081    @Override
082    public int[] answerSubnegotiation(final int suboptionData[], final int suboptionLength) {
083        if ((suboptionData != null) && (suboptionLength > 1) && (termType != null)) {
084            if ((suboptionData[0] == TERMINAL_TYPE) && (suboptionData[1] == TERMINAL_TYPE_SEND)) {
085                final int response[] = new int[termType.length() + 2];
086
087                response[0] = TERMINAL_TYPE;
088                response[1] = TERMINAL_TYPE_IS;
089
090                for (int ii = 0; ii < termType.length(); ii++) {
091                    response[ii + 2] = termType.charAt(ii);
092                }
093
094                return response;
095            }
096        }
097        return null;
098    }
099}