    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 *      https://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 storehouse for Telnet option constants.
    022 * <p>
    023 * Details regarding Telnet option specification can be found in RFC 855.
    024 * </p>
    025 *
    026 * @see org.apache.commons.net.telnet.Telnet
    027 * @see org.apache.commons.net.telnet.TelnetClient
    028 */
    029public class TelnetOption {
    030
    031    /** The maximum value an option code can have. This value is 255. */
    032    public static final int MAX_OPTION_VALUE = 255;
    033
    034    /**
    035     * {@value}
    036     */
    037    public static final int BINARY = 0;
    038
    039    /**
    040     * {@value}
    041     */
    042    public static final int ECHO = 1;
    043
    044    /**
    045     * {@value}
    046     */
    047    public static final int PREPARE_TO_RECONNECT = 2;
    048
    049    /**
    050     * {@value}
    051     */
    052    public static final int SUPPRESS_GO_AHEAD = 3;
    053
    054    /**
    055     * {@value}
    056     */
    057    public static final int APPROXIMATE_MESSAGE_SIZE = 4;
    058
    059    /**
    060     * {@value}
    061     */
    062    public static final int STATUS = 5;
    063
    064    /**
    065     * {@value}
    066     */
    067    public static final int TIMING_MARK = 6;
    068
    069    /**
    070     * {@value}
    071     */
    072    public static final int REMOTE_CONTROLLED_TRANSMISSION = 7;
    073
    074    /**
    075     * {@value}
    076     */
    077    public static final int NEGOTIATE_OUTPUT_LINE_WIDTH = 8;
    078
    079    /**
    080     * {@value}
    081     */
    082    public static final int NEGOTIATE_OUTPUT_PAGE_SIZE = 9;
    083
    084    /**
    085     * {@value}
    086     */
    087    public static final int NEGOTIATE_CARRIAGE_RETURN = 10;
    088
    089    /**
    090     * {@value}
    091     */
    092    public static final int NEGOTIATE_HORIZONTAL_TAB_STOP = 11;
    093
    094    /**
    095     * {@value}
    096     */
    097    public static final int NEGOTIATE_HORIZONTAL_TAB = 12;
    098
    099    /**
    100     * {@value}
    101     */
    102    public static final int NEGOTIATE_FORMFEED = 13;
    103
    104    /**
    105     * {@value}
    106     */
    107    public static final int NEGOTIATE_VERTICAL_TAB_STOP = 14;
    108
    109    /**
    110     * {@value}
    111     */
    112    public static final int NEGOTIATE_VERTICAL_TAB = 15;
    113
    114    /**
    115     * {@value}
    116     */
    117    public static final int NEGOTIATE_LINEFEED = 16;
    118
    119    /**
    120     * {@value}
    121     */
    122    public static final int EXTENDED_ASCII = 17;
    123
    124    /**
    125     * {@value}
    126     */
    127    public static final int FORCE_LOGOUT = 18;
    128
    129    /**
    130     * {@value}
    131     */
    132    public static final int BYTE_MACRO = 19;
    133
    134    /**
    135     * {@value}
    136     */
    137    public static final int DATA_ENTRY_TERMINAL = 20;
    138
    139    /**
    140     * {@value}
    141     */
    142    public static final int SUPDUP = 21;
    143
    144    /**
    145     * {@value}
    146     */
    147    public static final int SUPDUP_OUTPUT = 22;
    148
    149    /**
    150     * {@value}
    151     */
    152    public static final int SEND_LOCATION = 23;
    153
    154    /**
    155     * {@value}
    156     */
    157    public static final int TERMINAL_TYPE = 24;
    158
    159    /**
    160     * {@value}
    161     */
    162    public static final int END_OF_RECORD = 25;
    163
    164    /**
    165     * {@value}
    166     */
    167    public static final int TACACS_USER_IDENTIFICATION = 26;
    168
    169    /**
    170     * {@value}
    171     */
    172    public static final int OUTPUT_MARKING = 27;
    173
    174    /**
    175     * {@value}
    176     */
    177    public static final int TERMINAL_LOCATION_NUMBER = 28;
    178
    179    /**
    180     * {@value}
    181     */
    182    public static final int REGIME_3270 = 29;
    183
    184    /**
    185     * {@value}
    186     */
    187    public static final int X3_PAD = 30;
    188
    189    /**
    190     * {@value}
    191     */
    192    public static final int WINDOW_SIZE = 31;
    193
    194    /**
    195     * {@value}
    196     */
    197    public static final int TERMINAL_SPEED = 32;
    198
    199    /**
    200     * {@value}
    201     */
    202    public static final int REMOTE_FLOW_CONTROL = 33;
    203
    204    /**
    205     * {@value}
    206     */
    207    public static final int LINEMODE = 34;
    208
    209    /**
    210     * {@value}
    211     */
    212    public static final int X_DISPLAY_LOCATION = 35;
    213
    214    /**
    215     * {@value}
    216     */
    217    public static final int OLD_ENVIRONMENT_VARIABLES = 36;
    218
    219    /**
    220     * {@value}
    221     */
    222    public static final int AUTHENTICATION = 37;
    223
    224    /**
    225     * {@value}
    226     */
    227    public static final int ENCRYPTION = 38;
    228
    229    /**
    230     * {@value}
    231     */
    232    public static final int NEW_ENVIRONMENT_VARIABLES = 39;
    233
    234    /**
    235     * {@value}
    236     */
    237    public static final int EXTENDED_OPTIONS_LIST = 255;
    238
    239    /**
    240     * {@value}
    241     */
    242    @SuppressWarnings("unused")
    243    private static final int FIRST_OPTION = BINARY;
    244
    245    /**
    246     * {@value}
    247     */
    248    private static final int LAST_OPTION = EXTENDED_OPTIONS_LIST;
    249
    250    /**
    251     * {@value}
    252     */
    253    private static final String[] optionString = { "BINARY", "ECHO", "RCP", "SUPPRESS GO AHEAD", "NAME", "STATUS", "TIMING MARK", "RCTE", "NAOL", "NAOP",
    254            "NAOCRD", "NAOHTS", "NAOHTD", "NAOFFD", "NAOVTS", "NAOVTD", "NAOLFD", "EXTEND ASCII", "LOGOUT", "BYTE MACRO", "DATA ENTRY TERMINAL", "SUPDUP",
    255            "SUPDUP OUTPUT", "SEND LOCATION", "TERMINAL TYPE", "END OF RECORD", "TACACS UID", "OUTPUT MARKING", "TTYLOC", "3270 REGIME", "X.3 PAD", "NAWS",
    256            "TSPEED", "LFLOW", "LINEMODE", "XDISPLOC", "OLD-ENVIRON", "AUTHENTICATION", "ENCRYPT", "NEW-ENVIRON", "TN3270E", "XAUTH", "CHARSET", "RSP",
    257            "Com Port Control", "Suppress Local Echo", "Start TLS", "KERMIT", "SEND-URL", "FORWARD_X", "", "", "", "", "", "", "", "", "", "", "", "", "", "",
    258            "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "",
    259            "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "",
    260            "TELOPT PRAGMA LOGON", "TELOPT SSPI LOGON", "TELOPT PRAGMA HEARTBEAT", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "",
    261            "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "",
    262            "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "",
    263            "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "Extended-Options-List" };
    264
    265    /**
    266     * Returns the string representation of the Telnet protocol option corresponding to the given option code.
    267     *
    268     * @param code The option code of the Telnet protocol option
    269     * @return The string representation of the Telnet protocol option.
    270     */
    271    public static final String getOption(final int code) {
    272        if (optionString[code].isEmpty()) {
    273            return "UNASSIGNED";
    274        }
    275        return optionString[code];
    276    }
    277
    278    /**
    279     * Determines if a given option code is valid. Returns true if valid, false if not.
    280     *
    281     * @param code The option code to test.
    282     * @return True if the option code is valid, false if not.
    283     **/
    284    public static final boolean isValidOption(final int code) {
    285        return code <= LAST_OPTION;
    286    }
    287
    288    /** Cannot be instantiated. */
    289    private TelnetOption() {
    290    }
    291}