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	/*
	* Copyright (c) 2002, 2007, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code 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
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package com.sun.jmx.snmp.IPAcl;

	import static com.sun.jmx.defaults.JmxProperties.SNMP_LOGGER;

	import java.util.logging.Level;
	import java.util.Vector;
	import java.util.Enumeration;
	import java.io.Serializable;
	import java.net.UnknownHostException;
	import java.net.InetAddress;

	import java.security.Principal;
	import java.security.acl.Group;


	/**
	* This class is used to represent a subnet mask (a group of hosts matching the same
	* IP mask).
	*
	* @see java.security.acl.Group
	*/

	class NetMaskImpl extends PrincipalImpl implements Group, Serializable {
	private static final long serialVersionUID = -7332541893877932896L;

	protected byte[] subnet = null;
	protected int prefix = -1;
	/**
	* Constructs an empty group.
	* @exception UnknownHostException Not implemented
	*/
	public NetMaskImpl () throws UnknownHostException {
	}

	private byte[] extractSubNet(byte[] b) {
	int addrLength = b.length;
	byte[] subnet = null;
	if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
	SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(),
	"extractSubNet", "BINARY ARRAY :");
	StringBuffer buff = new StringBuffer();
	for(int i =0; i < addrLength; i++) {
	buff.append((b[i] &0xFF) +":");
	}
	SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(),
	"extractSubNet", buff.toString());
	}

	// 8 is a byte size. Common to any InetAddress (V4 or V6).
	int fullyCoveredByte = prefix / 8;
	if(fullyCoveredByte == addrLength) {
	if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
	SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "extractSubNet",
	"The mask is the complete address, strange..." + addrLength);
	}
	subnet = b;
	return subnet;
	}
	if(fullyCoveredByte > addrLength) {
	if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
	SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "extractSubNet",
	"The number of covered byte is longer than the address. BUG");
	}
	throw new IllegalArgumentException("The number of covered byte is longer than the address.");
	}
	int partialyCoveredIndex = fullyCoveredByte;
	if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
	SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "extractSubNet",
	"Partially covered index : " + partialyCoveredIndex);
	}
	byte toDeal = b[partialyCoveredIndex];
	if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
	SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "extractSubNet",
	"Partially covered byte : " + toDeal);
	}

	// 8 is a byte size. Common to any InetAddress (V4 or V6).
	int nbbits = prefix % 8;
	int subnetSize = 0;

	if(nbbits == 0)
	subnetSize = partialyCoveredIndex;
	else
	subnetSize = partialyCoveredIndex + 1;

	if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
	SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "extractSubNet",
	"Remains : " + nbbits);
	}

	byte mask = 0;
	for(int i = 0; i < nbbits; i++) {
	mask \|= (1 << (7 - i));
	}
	if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
	SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "extractSubNet",
	"Mask value : " + (mask & 0xFF));
	}

	byte maskedValue = (byte) ((int)toDeal & (int)mask);

	if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
	SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "extractSubNet",
	"Masked byte : " + (maskedValue &0xFF));
	}
	subnet = new byte[subnetSize];
	if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
	SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "extractSubNet",
	"Resulting subnet : ");
	}
	for(int i = 0; i < partialyCoveredIndex; i++) {
	subnet[i] = b[i];

	if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
	SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "extractSubNet",
	(subnet[i] & 0xFF) +":");
	}
	}

	if(nbbits != 0) {
	subnet[partialyCoveredIndex] = maskedValue;
	if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
	SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "extractSubNet",
	"Last subnet byte : " + (subnet[partialyCoveredIndex] &0xFF));
	}
	}
	return subnet;
	}

	/**
	* Constructs a group using the specified subnet mask.
	* THIS ALGORITHM IS V4 and V6 compatible.
	*
	* @exception UnknownHostException if the subnet mask cann't be built.
	*/
	public NetMaskImpl (String a, int prefix) throws UnknownHostException {
	super(a);
	this.prefix = prefix;
	subnet = extractSubNet(getAddress().getAddress());
	}

	/**
	* Adds the specified member to the group.
	*
	* @param p the principal to add to this group.
	* @return true if the member was successfully added, false if the
	* principal was already a member.
	*/
	public boolean addMember(Principal p) {
	// we don't need to add members because the ip address is a subnet mask
	return true;
	}

	public int hashCode() {
	return super.hashCode();
	}

	/**
	* Compares this group to the specified object. Returns true if the object
	* passed in matches the group represented.
	*
	* @param p the object to compare with.
	* @return true if the object passed in matches the subnet mask,
	* false otherwise.
	*/
	public boolean equals (Object p) {
	if (p instanceof PrincipalImpl \|\| p instanceof NetMaskImpl){
	PrincipalImpl received = (PrincipalImpl) p;
	InetAddress addr = received.getAddress();
	if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
	SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "equals",
	"Received Address : " + addr);
	}
	byte[] recAddr = addr.getAddress();
	for(int i = 0; i < subnet.length; i++) {
	if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
	SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "equals",
	"(recAddr[i]) : " + (recAddr[i] & 0xFF));
	SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "equals",
	"(recAddr[i] & subnet[i]) : " +
	((recAddr[i] & (int)subnet[i]) &0xFF) +
	" subnet[i] : " + (subnet[i] &0xFF));
	}
	if((recAddr[i] & subnet[i]) != subnet[i]) {
	if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
	SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "equals",
	"FALSE");
	}
	return false;
	}
	}
	if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
	SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "equals",
	"TRUE");
	}
	return true;
	} else
	return false;
	}
	/**
	* Returns true if the passed principal is a member of the group.
	*
	* @param p the principal whose membership is to be checked.
	* @return true if the principal is a member of this group, false otherwise.
	*/
	public boolean isMember(Principal p) {
	if ((p.hashCode() & super.hashCode()) == p.hashCode()) return true;
	else return false;
	}

	/**
	* Returns an enumeration which contains the subnet mask.
	*
	* @return an enumeration which contains the subnet mask.
	*/
	public Enumeration<? extends Principal> members(){
	Vector<Principal> v = new Vector<Principal>(1);
	v.addElement(this);
	return v.elements();
	}

	/**
	* Removes the specified member from the group. (Not implemented)
	*
	* @param p the principal to remove from this group.
	* @return allways return true.
	*/
	public boolean removeMember(Principal p) {
	return true;
	}

	/**
	* Prints a string representation of this group.
	*
	* @return a string representation of this group.
	*/
	public String toString() {
	return ("NetMaskImpl :"+ super.getAddress().toString() + "/" + prefix);
	}

	}

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