protocols/ip/IPv4Address.java

//
// 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 Aug 21: Changes to support ScriptD.
//
// 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       <license@opennms.org>
//      http://www.opennms.org/
//      http://www.opennms.com/
//

package org.opennms.protocols.ip;

import java.io.Serializable;
import java.net.InetAddress;
import java.util.StringTokenizer;

/**
 * Represents an Internet Protocol version 4 address. An IPv4 address is a
 * 32-bit address that can be considered four eight bit octets. Each octet
 * represents a number in the range of [0..256). A string representation is a
 * dotted decimal address in the form of "xxx.xxx.xxx.xxx" where xxx is a single
 * octet.
 *
 * The main purpose of the class is to represent an IPv4 Address without the
 * associated lookup baggage in the java.net.InetAddress class.
 *
 *
 * @author Brian Weaver &lt;weave@oculan.com&gt;
 */
public class IPv4Address extends Object implements Serializable {
    static final long serialVersionUID = 1946711645921732057L; // generated by
                                                                // serialver
                                                                // tool

    private byte[] m_addr; // 4 byte address

    /**
     * Duplicates the array of bytes.
     *
     * @param src
     *            The source bytes to duplicate.
     *
     * @return The duplicated array of bytes.
     */
    private byte[] dup(byte[] src) {
        byte[] cpy = null;
        if (src != null) {
            cpy = new byte[src.length];
            for (int x = 0; x < src.length; x++) {
                cpy[x] = src[x];
            }
        }
        return cpy;
    }

    /**
     * Converts a byte to an integer, treating the byte as unsigned.
     *
     * @param b
     *            The byte to convert.
     *
     * @return The converted value.
     *
     */
    private static int byteToInt(byte b) {
        int r = (int) b;
        if (r < 0)
            r += 256;
        return r;
    }

    /**
     * Converts the passed 32-bit IPv4 address to a dotted decimal IP address
     * string.
     *
     * @param ipv4Addr
     *            The 32-bit address
     *
     * @return The dotted decimal address in the format "xxx.xxx.xxx.xxx" where
     *         0 <= xxx < 256
     *
     */
    public static String addressToString(int ipv4Addr) {
        StringBuffer buf = new StringBuffer();
        buf.append((ipv4Addr >> 24) & 0xff);
        buf.append('.');
        buf.append((ipv4Addr >> 16) & 0xff);
        buf.append('.');
        buf.append((ipv4Addr >> 8) & 0xff);
        buf.append('.');
        buf.append(ipv4Addr & 0xff);

        return buf.toString();
    }

    /**
     * Converts the passed IPv4 address buffer to a dotted decimal IP address
     * string.
     *
     * @param buf
     *            The 4 byte buffer
     *
     * @return The dotted decimal address in the format "xxx.xxx.xxx.xxx" where
     *         0 <= xxx < 256
     *
     * @exception IllegalArgumentException
     *                Thrown if the buffer is not exactly 4 bytes in length.
     */
    public static String addressToString(byte[] buf) {
        if (buf.length != 4)
            throw new IllegalArgumentException("IPv4 Address must be 4-bytes in length");

        int a = byteToInt(buf[0]);
        int b = byteToInt(buf[1]);
        int c = byteToInt(buf[2]);
        int d = byteToInt(buf[3]);

        StringBuffer sbuf = new StringBuffer();
        sbuf.append(a).append('.').append(b).append('.').append(c).append('.').append(d);

        return sbuf.toString();
    }

    /**
     * Constructs a new IPv4Address object. The default value for the object is
     * "0.0.0.0"
     *
     */
    public IPv4Address() {
        m_addr = new byte[4];
        m_addr[0] = 0;
        m_addr[1] = 0;
        m_addr[2] = 0;
        m_addr[3] = 0;
    }

    /**
     * Constructs a new address object based upon the value of the first object.
     *
     * @param second
     *            The object to copy the address from.
     */
    public IPv4Address(IPv4Address second) {
        m_addr = dup(second.m_addr);
    }

    /**
     * Constructs a new object based on the value stored in the passed array. An
     * IPv4 Address is 32-bits in length, thus the array must have exactly 4
     * elements.
     *
     * @param addr
     *            The IPv4Address data
     *
     * @exception IllegalArgumentException
     *                Thrown if the passed buffer is not in the correct format
     *                for an IPv4Address.
     *
     */
    public IPv4Address(byte[] addr) {
        if (addr.length != 4)
            throw new IllegalArgumentException("Invalid address length");

        m_addr = dup(addr);
    }

    /**
     * Constructs a new address object based on the 32-bit passed value. The
     * 32-bit integer is split into four eight bit values that represent the
     * IPv4 address.
     *
     * @param ipv4Addr
     *            The 32-bit IP address.
     *
     */
    public IPv4Address(int ipv4Addr) {
        m_addr = new byte[4];
        m_addr[0] = (byte) (ipv4Addr >>> 24);
        m_addr[1] = (byte) ((ipv4Addr >> 16) & 0xff);
        m_addr[2] = (byte) ((ipv4Addr >> 8) & 0xff);
        m_addr[3] = (byte) (ipv4Addr & 0xff);
    }

    /**
     * Creates a new object by decomposing the passed string into it four
     * components. The string must be in the format of "xxx.xxx.xxx.xxx" where
     * xxx is in the range of [0..256).
     *
     * @param ipv4Addr
     *            The dotted decimal address.
     *
     * @exception IllegalArgumentException
     *                Thrown if the string is a malformed dotted decimal
     *                address.
     *
     */
    public IPv4Address(String ipv4Addr) {
        StringTokenizer tok = new StringTokenizer(ipv4Addr, ".");
        if (tok.countTokens() != 4)
            throw new IllegalArgumentException("Invalid Dotted Decimal IPv4 Address");
        m_addr = new byte[4];

        int x;
        for (x = 0; x < 4; x++) {
            int converted = Integer.parseInt(tok.nextToken());
            if (converted < 0 || converted > 255)
                throw new IllegalArgumentException("Invalid IPv4 Address string");

            m_addr[x] = (byte) (converted & 0xff);
        }
    }

    /**
     * Creates a new IPv4Address from the passed InetAddress object.
     *
     * @param addr
     *            The Internet Address containing the IPv4 address.
     *
     */
    public IPv4Address(InetAddress addr) {
        m_addr = dup(addr.getAddress());
    }

    /**
     * Returns the 32-bit IPv4 address.
     *
     * @return 32-bit IPv4 address
     *
     */
    public int getAddress() {
        int addr = byteToInt(m_addr[0]) << 24;
        addr |= byteToInt(m_addr[1]) << 16;
        addr |= byteToInt(m_addr[2]) << 8;
        addr |= byteToInt(m_addr[3]);

        return addr;
    }

    /**
     * Returns the IPv4 address in the form of an array of 4 bytes
     *
     * @return the IPv4 address bytes
     *
     */
    public byte[] getAddressBytes() {
        return m_addr.clone();
    }

    /**
     * Sets the current address based upon the value of the passed object.
     *
     * @param second
     *            The new address.
     */
    public void setAddress(IPv4Address second) {
        m_addr = dup(second.m_addr);
    }

    /**
     * Sets the object based on the value stored in the passed array. An IPv4
     * Address is 32-bits in length, thus the array must have exactly 4
     * elements.
     *
     * @param addr
     *            The IPv4Address data
     *
     * @exception IllegalArgumentException
     *                Thrown if the passed buffer is not in the correct format
     *                for an IPv4Address.
     *
     */
    public void setAddress(byte[] addr) {
        if (addr.length != 4)
            throw new IllegalArgumentException("Invalid address length");

        m_addr = dup(addr);
    }

    /**
     * Sets the address object based on the 32-bit passed value. The 32-bit
     * integer is split into four eight bit values that represent the IPv4
     * address.
     *
     * @param ipv4Addr
     *            The 32-bit IP address.
     *
     */
    public void setAddress(int ipv4Addr) {
        m_addr = new byte[4];
        m_addr[0] = (byte) (ipv4Addr >>> 24);
        m_addr[1] = (byte) ((ipv4Addr >> 16) & 0xff);
        m_addr[2] = (byte) ((ipv4Addr >> 8) & 0xff);
        m_addr[3] = (byte) (ipv4Addr & 0xff);
    }

    /**
     * Sets the object by decomposing the passed string into it four components.
     * The string must be in the format of "xxx.xxx.xxx.xxx" where xxx is in the
     * range of [0..256).
     *
     * @param ipv4Addr
     *            The dotted decimal address.
     *
     * @exception IllegalArgumentException
     *                Thrown if the string is a malformed dotted decimal
     *                address.
     *
     */
    public void setAddress(String ipv4Addr) {
        StringTokenizer tok = new StringTokenizer(ipv4Addr, ".");
        if (tok.countTokens() != 4)
            throw new IllegalArgumentException("Invalid Dotted Decimal IPv4 Address");
        m_addr = new byte[4];

        int x;
        for (x = 0; x < 4; x++) {
            int converted = Integer.parseInt(tok.nextToken());
            if (converted < 0 || converted > 255)
                throw new IllegalArgumentException("Invalid IPv4 Address string");

            m_addr[x] = (byte) (converted & 0xff);
        }
    }

    /**
     * Sets the IPv4Address from the passed InetAddress object.
     *
     * @param addr
     *            The Internet Address containing the IPv4 address.
     *
     */
    public void setAddress(InetAddress addr) {
        m_addr = dup(addr.getAddress());
    }

    /**
     * Test to determine if the passed object is equal to self. The object may
     * be an Integer, String, or IPv4Address. If the object is a String then it
     * must be in the dotted decimal string format.
     *
     * @param obj
     *            The object to use in the comparison.
     *
     * @return True if equal, false if not equal.
     */
    public boolean equals(Object obj) {
        boolean bRC = false;

        if (obj instanceof IPv4Address) {
            byte[] t = ((IPv4Address) obj).m_addr;
            int x;

            bRC = true;
            for (x = 0; x < 4; x++) {
                if (m_addr[x] != t[x]) {
                    bRC = false;
                }
            }
        } else if (obj instanceof Integer) {
            if (((Integer) obj).intValue() == getAddress()) {
                bRC = true;
            }
        } else if (obj instanceof String) {
            try {
                IPv4Address addr = new IPv4Address((String) obj);
                bRC = this.equals(addr);
            } catch (IllegalArgumentException e) {
                bRC = false;
            }
        }

        return bRC;
    }

    /**
     * If you override equals() you need to make a hashCode implementation as well
     */
    public int hashCode() {
    	return toString().hashCode();
    }

    /**
     * Converts the object to a string and returns the string to the caller.
     *
     * @return The dotted decimal string for the address
     *
     */
    public String toString() {
        return addressToString(m_addr);
    }

}