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    /***
026     * Terminal type
027     ***/
028    private final String termType;
029
030    /***
031     * Terminal type option
032     ***/
033    protected static final int TERMINAL_TYPE = 24;
034
035    /***
036     * Send (for subnegotiation)
037     ***/
038    protected static final int TERMINAL_TYPE_SEND =  1;
039
040    /***
041     * Is (for subnegotiation)
042     ***/
043    protected static final int TERMINAL_TYPE_IS =  0;
044
045    /***
046     * Constructor for the TerminalTypeOptionHandler. Allows defining desired
047     * initial setting for local/remote activation of this option and
048     * behaviour in case a local/remote activation request for this
049     * option is received.
050     * <p>
051     * @param termtype - terminal type that will be negotiated.
052     * @param initlocal - if set to true, a WILL is sent upon connection.
053     * @param initremote - if set to true, a DO is sent upon connection.
054     * @param acceptlocal - if set to true, any DO request is accepted.
055     * @param acceptremote - if set to true, any WILL request is accepted.
056     ***/
057    public TerminalTypeOptionHandler(String termtype,
058                                boolean initlocal,
059                                boolean initremote,
060                                boolean acceptlocal,
061                                boolean acceptremote)
062    {
063        super(TelnetOption.TERMINAL_TYPE, initlocal, initremote,
064                                      acceptlocal, acceptremote);
065        termType = termtype;
066    }
067
068    /***
069     * Constructor for the TerminalTypeOptionHandler. Initial and accept
070     * behaviour flags are set to false
071     * <p>
072     * @param termtype - terminal type that will be negotiated.
073     ***/
074    public TerminalTypeOptionHandler(String termtype)
075    {
076        super(TelnetOption.TERMINAL_TYPE, false, false, false, false);
077        termType = termtype;
078    }
079
080    /***
081     * Implements the abstract method of TelnetOptionHandler.
082     * <p>
083     * @param suboptionData - the sequence received, without IAC SB &amp; IAC SE
084     * @param suboptionLength - the length of data in suboption_data
085     * <p>
086     * @return terminal type information
087     ***/
088    @Override
089    public int[] answerSubnegotiation(int suboptionData[], int suboptionLength)
090    {
091        if ((suboptionData != null) && (suboptionLength > 1)
092            && (termType != null))
093        {
094            if ((suboptionData[0] == TERMINAL_TYPE)
095                && (suboptionData[1] == TERMINAL_TYPE_SEND))
096            {
097                int response[] = new int[termType.length() + 2];
098
099                response[0] = TERMINAL_TYPE;
100                response[1] = TERMINAL_TYPE_IS;
101
102                for (int ii = 0; ii < termType.length(); ii++)
103                {
104                    response[ii + 2] = termType.charAt(ii);
105                }
106
107                return response;
108            }
109        }
110        return null;
111    }
112}