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}