icmpheader.java

来自「This a java ICMP JNI interface」· Java 代码 · 共 566 行 · 第 1/2 页

//
// This file is part of the OpenNMS(R) Application.
//
// OpenNMS(R) is Copyright (C) 2002-2003 The OpenNMS Group, Inc.  All rights reserved.
// OpenNMS(R) is a derivative work, containing both original code, included code and modified
// code that was published under the GNU General Public License. Copyrights for modified 
// and included code are below.
//
// OpenNMS(R) is a registered trademark of The OpenNMS Group, Inc.
//
// Modifications:
//
// 2003 Mar 05: Changes to support response times and more platforms.
//
// Original code base Copyright (C) 1999-2001 Oculan Corp.  All rights reserved.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
//
// For more information contact:
//      OpenNMS Licensing       <[e-mail]>
//      http://www.opennms.org/
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// Tab Size = 8
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package org.opennms.protocols.icmp;

import java.util.Date;
import java.util.Random;

import org.opennms.protocols.ip.OC16ChecksumProducer;

/**
 * This class defines Internet Control Message Protocol header. The header
 * defines the first 8 bytes of any ICMP message. Some ICMP messages may need to
 * override the format of the second 4 bytes, the first 4 bytes are fixed by the
 * RFC. The minimum message size for any ICMP message is 8 bytes.
 * 
 * @author Brian Weaver <[e-mail]>
 * @version 0.1
 * 
 */
public class ICMPHeader extends Object {
    public static final byte TYPE_ECHO_REPLY = (byte) 0;

    public static final byte TYPE_DESTINATION_UNREACHABLE = (byte) 3;

    public static final byte CODE_NETWORK_UNREACHABLE = (byte) 0;

    public static final byte CODE_HOST_UNREACHABLE = (byte) 1;

    public static final byte CODE_PROTOCOL_UNREACHABLE = (byte) 2;

    public static final byte CODE_PORT_UNREACHABLE = (byte) 3;

    public static final byte CODE_FRAGMENTATION_NEEDED = (byte) 4;

    public static final byte CODE_SOURCE_ROUTE_FAILED = (byte) 5;

    public static final byte CODE_DESTINATION_NETWORK_UNKNOWN = (byte) 6;

    public static final byte CODE_DESTINATION_HOST_UNKNOWN = (byte) 7;

    public static final byte CODE_SOURCE_HOST_ISOLATED = (byte) 8;

    public static final byte CODE_DESTINATION_NETWORK_ADMIN_PROHIBITED = (byte) 9;

    public static final byte CODE_DESTINATION_HOST_ADMIN_PROHIBITED = (byte) 10;

    public static final byte CODE_NETWORK_UNREACHABLE_FOR_TOS = (byte) 11;

    public static final byte CODE_HOST_UNREACHABLE_FOR_TOS = (byte) 12;

    public static final byte CODE_COMMUNICATIONS_ADMIN_PROHIBITIED = (byte) 13;

    public static final byte CODE_HOST_PRECEDENCE_VIOLATION = (byte) 14;

    public static final byte CODE_PRECEDENCE_CUTOFF_IN_EFFECT = (byte) 15;

    public static final byte TYPE_SOURCE_QUENCH = (byte) 4;

    public static final byte TYPE_REDIRECT = (byte) 5;

    public static final byte CODE_REDIRECT_FOR_NETWORK = (byte) 0;

    public static final byte CODE_REDIRECT_FOR_HOST = (byte) 1;

    public static final byte CODE_REDIRECT_FOR_TYPE_OF_SERVICE_AND_NETWORK = (byte) 2;

    public static final byte CODE_REDIRECT_FOR_TYPE_OF_SERVICE_AND_HOST = (byte) 3;

    public static final byte TYPE_ECHO_REQUEST = (byte) 8;

    public static final byte TYPE_ROUTER_ADVERTISEMENT = (byte) 9;

    public static final byte TYPE_ROUTER_SOLICITATION = (byte) 10;

    public static final byte TYPE_TIME_EXCEEDED = (byte) 11;

    public static final byte CODE_TTL_EQ_ZERO_IN_TRANSIT = (byte) 0;

    public static final byte CODE_TTL_EQ_ZERO_IN_REASSEMBLY = (byte) 1;

    public static final byte TYPE_PARAMETER_PROBLEM = (byte) 12;

    public static final byte CODE_BAD_IP_HEADER = (byte) 0;

    public static final byte CODE_REQUIRED_OPTION_MISSING = (byte) 1;

    public static final byte TYPE_TIMESTAMP_REQUEST = (byte) 13;

    public static final byte TYPE_TIMESTAMP_REPLY = (byte) 14;

    public static final byte TYPE_INFORMATION_REQUEST = (byte) 15;

    public static final byte TYPE_INFORMATION_REPLY = (byte) 16;

    public static final byte TYPE_ADDRESS_MASK_REQUEST = (byte) 17;

    public static final byte TYPE_ADDRESS_MASK_REPLY = (byte) 18;

    private byte m_type; // ECHO_REQUEST, ECHO_REPLY, etc...

    private byte m_code; // echo code

    private short m_checksum; // 16-bit one's complement checksum

    private short m_ident; // 16-bit identity

    private short m_sequence; // 16-bit sequence

    /**
     * Used to generate the sequence numbers for the class. This number is
     * generated application wide.
     * 
     */
    private static short sm_seq = 0;

    /**
     * Returns the next 16-bit sequence identifier for the class. The method is
     * synchronized to prevent duplicate identifiers from being issued.
     * depending on the number of classes and how often the method is called it
     * will eventually wrap. When the value wraps back to zero, a random number
     * is generated and may cause a collision with an existing identifier. The
     * probability is low, but possible.
     * 
     * @return The next 16-bit sequence number, may be negative.
     */
    public final static synchronized short nextSequenceId() {
        if (sm_seq == 0) {
            Date d = new Date();
            Random r = new Random(d.getTime());
            sm_seq = (short) (r.nextInt());
        }
        return ++sm_seq;
    }

    /**
     * Converts a byte to a short.
     * 
     * @param b
     *            The byte to convert.
     * 
     * @return The converted byte.
     * 
     */
    protected static short byteToShort(byte b) {
        short s = (short) b;
        if (s < 0)
            s += 256;
        return s;
    }

    /**
     * Converts a byte to an integer.
     * 
     * @param b
     *            The byte to convert.
     * 
     * @return The converted byte.
     * 
     */
    protected static int byteToInt(byte b) {
        int i = (int) b;
        if (i < 0)
            i += 256;
        return i;
    }

    /**
     * Initializes the header to a default value.
     */
    public ICMPHeader() {
        m_type = 0;
        m_code = 0;
        m_checksum = 0;
        m_ident = 0;
        m_sequence = 0;
    }

    /**
     * Initializes the header using the specified type.
     * 
     * @param type
     *            The header type.
     * 
     */
    public ICMPHeader(byte type) {
        this();
        m_type = type;
    }

    /**
     * Initializes the header with the specified type and code values.
     * 
     * @param type
     *            The type value for the header
     * @param code
     *            The code value for the header
     * 
     */
    public ICMPHeader(byte type, byte code) {
        this(type);
        m_code = code;
    }

    /**
     * Constructs an ICMP header with the specified header fields.
     * 
     * @param type
     *            The 8-bit ICMP type.
     * @param code
     *            The 8-bit ICMP code.
     * @param checksum
     *            The 16-bit checksum header.
     * @param identity
     *            The 16-bit identity (user).
     * @param sequence
     *            The 16-bit sequence id.
     * 
     */
    public ICMPHeader(byte type, byte code, short checksum, short identity, short sequence) {
        m_type = type;
        m_code = code;
        m_checksum = checksum;
        m_ident = identity;
        m_sequence = sequence;
    }

    /**
     * Constructs a duplicate ICMP header that is identical to the passed
     * ICMPHeader object.
     * 
     * @param second
     *            The object to duplicate.
     * 
     */
    public ICMPHeader(ICMPHeader second) {
        m_type = second.m_type;
        m_code = second.m_code;
        m_checksum = second.m_checksum;
        m_sequence = second.m_sequence;
        m_ident = second.m_ident;
    }

    /**
     * <P>
     * Constructs a new ICMP header based upon the data contained in the buffer.
     * The buffer is decode in network byte ordering (big-endin) and must be at
     * least a {@link #getNetworkSize minimum}number of bytes available to be