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