    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 * The TelnetOption class cannot be instantiated and only serves as a
    022 * storehouse for telnet option constants.
    023 * <p>
    024 * Details regarding Telnet option specification can be found in RFC 855.
    025 *
    026 *
    027 * @see org.apache.commons.net.telnet.Telnet
    028 * @see org.apache.commons.net.telnet.TelnetClient
    029 */
    030
    031public class TelnetOption
    032{
    033    /** The maximum value an option code can have.  This value is 255. */
    034    public static final int MAX_OPTION_VALUE = 255;
    035
    036    public static final int BINARY = 0;
    037
    038    public static final int ECHO = 1;
    039
    040    public static final int PREPARE_TO_RECONNECT = 2;
    041
    042    public static final int SUPPRESS_GO_AHEAD = 3;
    043
    044    public static final int APPROXIMATE_MESSAGE_SIZE = 4;
    045
    046    public static final int STATUS = 5;
    047
    048    public static final int TIMING_MARK = 6;
    049
    050    public static final int REMOTE_CONTROLLED_TRANSMISSION = 7;
    051
    052    public static final int NEGOTIATE_OUTPUT_LINE_WIDTH = 8;
    053
    054    public static final int NEGOTIATE_OUTPUT_PAGE_SIZE = 9;
    055
    056    public static final int NEGOTIATE_CARRIAGE_RETURN = 10;
    057
    058    public static final int NEGOTIATE_HORIZONTAL_TAB_STOP = 11;
    059
    060    public static final int NEGOTIATE_HORIZONTAL_TAB = 12;
    061
    062    public static final int NEGOTIATE_FORMFEED = 13;
    063
    064    public static final int NEGOTIATE_VERTICAL_TAB_STOP = 14;
    065
    066    public static final int NEGOTIATE_VERTICAL_TAB = 15;
    067
    068    public static final int NEGOTIATE_LINEFEED = 16;
    069
    070    public static final int EXTENDED_ASCII = 17;
    071
    072    public static final int FORCE_LOGOUT = 18;
    073
    074    public static final int BYTE_MACRO = 19;
    075
    076    public static final int DATA_ENTRY_TERMINAL = 20;
    077
    078    public static final int SUPDUP = 21;
    079
    080    public static final int SUPDUP_OUTPUT = 22;
    081
    082    public static final int SEND_LOCATION = 23;
    083
    084    public static final int TERMINAL_TYPE = 24;
    085
    086    public static final int END_OF_RECORD = 25;
    087
    088    public static final int TACACS_USER_IDENTIFICATION = 26;
    089
    090    public static final int OUTPUT_MARKING = 27;
    091
    092    public static final int TERMINAL_LOCATION_NUMBER = 28;
    093
    094    public static final int REGIME_3270 = 29;
    095
    096    public static final int X3_PAD = 30;
    097
    098    public static final int WINDOW_SIZE = 31;
    099
    100    public static final int TERMINAL_SPEED = 32;
    101
    102    public static final int REMOTE_FLOW_CONTROL = 33;
    103
    104    public static final int LINEMODE = 34;
    105
    106    public static final int X_DISPLAY_LOCATION = 35;
    107
    108    public static final int OLD_ENVIRONMENT_VARIABLES = 36;
    109
    110    public static final int AUTHENTICATION = 37;
    111
    112    public static final int ENCRYPTION = 38;
    113
    114    public static final int NEW_ENVIRONMENT_VARIABLES = 39;
    115
    116    public static final int EXTENDED_OPTIONS_LIST = 255;
    117
    118    @SuppressWarnings("unused")
    119    private static final int FIRST_OPTION = BINARY;
    120    private static final int LAST_OPTION = EXTENDED_OPTIONS_LIST;
    121
    122    private static final String optionString[] = {
    123                "BINARY", "ECHO", "RCP", "SUPPRESS GO AHEAD", "NAME", "STATUS",
    124                "TIMING MARK", "RCTE", "NAOL", "NAOP", "NAOCRD", "NAOHTS", "NAOHTD",
    125                "NAOFFD", "NAOVTS", "NAOVTD", "NAOLFD", "EXTEND ASCII", "LOGOUT",
    126                "BYTE MACRO", "DATA ENTRY TERMINAL", "SUPDUP", "SUPDUP OUTPUT",
    127                "SEND LOCATION", "TERMINAL TYPE", "END OF RECORD", "TACACS UID",
    128                "OUTPUT MARKING", "TTYLOC", "3270 REGIME", "X.3 PAD", "NAWS", "TSPEED",
    129                "LFLOW", "LINEMODE", "XDISPLOC", "OLD-ENVIRON", "AUTHENTICATION",
    130                "ENCRYPT", "NEW-ENVIRON", "TN3270E", "XAUTH", "CHARSET", "RSP",
    131                "Com Port Control", "Suppress Local Echo", "Start TLS",
    132                "KERMIT", "SEND-URL", "FORWARD_X", "", "", "",
    133                "", "", "", "", "", "", "", "", "", "",
    134                "", "", "", "", "", "", "", "", "", "",
    135                "", "", "", "", "", "", "", "", "", "",
    136                "", "", "", "", "", "", "", "", "", "",
    137                "", "", "", "", "", "", "", "", "", "",
    138                "", "", "", "", "", "", "", "", "", "",
    139                "", "", "", "", "", "", "", "", "", "",
    140                "", "", "", "", "", "", "", "", "", "",
    141                "", "", "", "", "", "TELOPT PRAGMA LOGON", "TELOPT SSPI LOGON",
    142                "TELOPT PRAGMA HEARTBEAT", "", "", "", "",
    143                "", "", "", "", "", "", "", "", "", "",
    144                "", "", "", "", "", "", "", "", "", "",
    145                "", "", "", "", "", "", "", "", "", "",
    146                "", "", "", "", "", "", "", "", "", "",
    147                "", "", "", "", "", "", "", "", "", "",
    148                "", "", "", "", "", "", "", "", "", "",
    149                "", "", "", "", "", "", "", "", "", "",
    150                "", "", "", "", "", "", "", "", "", "",
    151                "", "", "", "", "", "", "", "", "", "",
    152                "", "", "", "", "", "", "", "", "", "",
    153                "", "", "", "", "", "", "", "", "", "",
    154                "Extended-Options-List"
    155            };
    156
    157
    158    /**
    159     * Returns the string representation of the telnet protocol option
    160     * corresponding to the given option code.
    161     *
    162     * @param code The option code of the telnet protocol option
    163     * @return The string representation of the telnet protocol option.
    164     */
    165    public static final String getOption(final int code)
    166    {
    167        if(optionString[code].isEmpty())
    168        {
    169            return "UNASSIGNED";
    170        }
    171        return optionString[code];
    172    }
    173
    174
    175    /**
    176     * Determines if a given option code is valid.  Returns true if valid,
    177     * false if not.
    178     *
    179     * @param code  The option code to test.
    180     * @return True if the option code is valid, false if not.
    181     **/
    182    public static final boolean isValidOption(final int code)
    183    {
    184        return code <= LAST_OPTION;
    185    }
    186
    187    // Cannot be instantiated
    188    private TelnetOption()
    189    { }
    190}