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