1 /*
   2  * Copyright (c) 2002, 2007, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.jmx.snmp.IPAcl;
  27 
  28 import static com.sun.jmx.defaults.JmxProperties.SNMP_LOGGER;
  29 
  30 import java.util.logging.Level;
  31 import java.util.Vector;
  32 import java.util.Enumeration;
  33 import java.io.Serializable;
  34 import java.net.UnknownHostException;
  35 import java.net.InetAddress;
  36 
  37 import java.security.Principal;
  38 import java.security.acl.Group;
  39 
  40 
  41 /**
  42  * This class is used to represent a subnet mask (a group of hosts matching the same
  43  * IP mask).
  44  *
  45  * @see java.security.acl.Group
  46  */
  47 
  48 class NetMaskImpl extends PrincipalImpl implements Group, Serializable {
  49     private static final long serialVersionUID = -7332541893877932896L;
  50 
  51     protected byte[] subnet = null;
  52     protected int prefix = -1;
  53     /**
  54      * Constructs an empty group.
  55      * @exception UnknownHostException Not implemented
  56      */
  57     public NetMaskImpl () throws UnknownHostException {
  58     }
  59 
  60     private byte[] extractSubNet(byte[] b) {
  61         int addrLength = b.length;
  62         byte[] subnet = null;
  63         if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
  64             SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(),
  65                 "extractSubNet", "BINARY ARRAY :");
  66             StringBuilder sb = new StringBuilder();
  67             for(int i =0; i < addrLength; i++) {
  68                 sb.append((b[i] & 0xFF) + ":");
  69             }
  70             SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(),
  71                 "extractSubNet", sb.toString());
  72         }
  73 
  74         // 8 is a byte size. Common to any InetAddress (V4 or V6).
  75         int fullyCoveredByte = prefix / 8;
  76         if(fullyCoveredByte == addrLength) {
  77             if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
  78                 SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "extractSubNet",
  79                    "The mask is the complete address, strange..." + addrLength);
  80             }
  81             subnet = b;
  82             return subnet;
  83         }
  84         if(fullyCoveredByte > addrLength) {
  85             if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
  86                 SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "extractSubNet",
  87                    "The number of covered byte is longer than the address. BUG");
  88             }
  89             throw new IllegalArgumentException("The number of covered byte is longer than the address.");
  90         }
  91         int partialyCoveredIndex = fullyCoveredByte;
  92         if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
  93             SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "extractSubNet",
  94                "Partially covered index : " + partialyCoveredIndex);
  95         }
  96         byte toDeal = b[partialyCoveredIndex];
  97         if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
  98             SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "extractSubNet",
  99                "Partially covered byte : " + toDeal);
 100         }
 101 
 102         // 8 is a byte size. Common to any InetAddress (V4 or V6).
 103         int nbbits = prefix % 8;
 104         int subnetSize = 0;
 105 
 106         if(nbbits == 0)
 107         subnetSize = partialyCoveredIndex;
 108         else
 109         subnetSize = partialyCoveredIndex + 1;
 110 
 111         if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
 112             SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "extractSubNet",
 113                "Remains : " + nbbits);
 114         }
 115 
 116         byte mask = 0;
 117         for(int i = 0; i < nbbits; i++) {
 118             mask |= (1 << (7 - i));
 119         }
 120         if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
 121             SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "extractSubNet",
 122                "Mask value : " + (mask & 0xFF));
 123         }
 124 
 125         byte maskedValue = (byte) ((int)toDeal & (int)mask);
 126 
 127         if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
 128             SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "extractSubNet",
 129                "Masked byte : "  + (maskedValue &0xFF));
 130         }
 131         subnet = new byte[subnetSize];
 132         if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
 133             SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "extractSubNet",
 134                "Resulting subnet : ");
 135         }
 136         for(int i = 0; i < partialyCoveredIndex; i++) {
 137             subnet[i] = b[i];
 138 
 139             if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
 140                 SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "extractSubNet",
 141                    (subnet[i] & 0xFF) +":");
 142             }
 143         }
 144 
 145         if(nbbits != 0) {
 146             subnet[partialyCoveredIndex] = maskedValue;
 147             if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
 148                 SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "extractSubNet",
 149                     "Last subnet byte : " + (subnet[partialyCoveredIndex] &0xFF));
 150             }
 151         }
 152         return subnet;
 153     }
 154 
 155   /**
 156    * Constructs a group using the specified subnet mask.
 157    * THIS ALGORITHM IS V4 and V6 compatible.
 158    *
 159    * @exception UnknownHostException if the subnet mask cann't be built.
 160    */
 161   public NetMaskImpl (String a, int prefix) throws UnknownHostException {
 162         super(a);
 163         this.prefix = prefix;
 164         subnet = extractSubNet(getAddress().getAddress());
 165   }
 166 
 167   /**
 168    * Adds the specified member to the group.
 169    *
 170    * @param p the principal to add to this group.
 171    * @return true if the member was successfully added, false if the
 172    *      principal was already a member.
 173    */
 174   public boolean addMember(Principal p) {
 175         // we don't need to add members because the ip address is a subnet mask
 176         return true;
 177   }
 178 
 179   public int hashCode() {
 180         return super.hashCode();
 181   }
 182 
 183   /**
 184    * Compares this group to the specified object. Returns true if the object
 185    * passed in matches the group represented.
 186    *
 187    * @param p the object to compare with.
 188    * @return true if the object passed in matches the subnet mask,
 189    *    false otherwise.
 190    */
 191     public boolean equals (Object p) {
 192         if (p instanceof PrincipalImpl || p instanceof NetMaskImpl){
 193             PrincipalImpl received = (PrincipalImpl) p;
 194             InetAddress addr = received.getAddress();
 195             if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
 196                 SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "equals",
 197                     "Received Address : " + addr);
 198             }
 199             byte[] recAddr = addr.getAddress();
 200             for(int i = 0; i < subnet.length; i++) {
 201                 if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
 202                     SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "equals",
 203                         "(recAddr[i]) : " + (recAddr[i] & 0xFF));
 204                     SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "equals",
 205                         "(recAddr[i] & subnet[i]) : " +
 206                          ((recAddr[i] & (int)subnet[i]) &0xFF) +
 207                          " subnet[i] : " + (subnet[i] &0xFF));
 208                 }
 209                 if((recAddr[i] & subnet[i]) != subnet[i]) {
 210                     if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
 211                         SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "equals",
 212                             "FALSE");
 213                     }
 214                     return false;
 215                 }
 216             }
 217             if (SNMP_LOGGER.isLoggable(Level.FINEST)) {
 218                 SNMP_LOGGER.logp(Level.FINEST, NetMaskImpl.class.getName(), "equals",
 219                     "TRUE");
 220             }
 221             return true;
 222         } else
 223             return false;
 224     }
 225   /**
 226    * Returns true if the passed principal is a member of the group.
 227    *
 228    * @param p the principal whose membership is to be checked.
 229    * @return true if the principal is a member of this group, false otherwise.
 230    */
 231   public boolean isMember(Principal p) {
 232         if ((p.hashCode() & super.hashCode()) == p.hashCode()) return true;
 233         else return false;
 234   }
 235 
 236   /**
 237    * Returns an enumeration which contains the subnet mask.
 238    *
 239    * @return an enumeration which contains the subnet mask.
 240    */
 241   public Enumeration<? extends Principal> members(){
 242         Vector<Principal> v = new Vector<Principal>(1);
 243         v.addElement(this);
 244         return v.elements();
 245   }
 246 
 247   /**
 248    * Removes the specified member from the group. (Not implemented)
 249    *
 250    * @param p the principal to remove from this group.
 251    * @return allways return true.
 252    */
 253   public boolean removeMember(Principal p) {
 254         return true;
 255   }
 256 
 257   /**
 258    * Prints a string representation of this group.
 259    *
 260    * @return  a string representation of this group.
 261    */
 262   public String toString() {
 263         return ("NetMaskImpl :"+ super.getAddress().toString() + "/" + prefix);
 264   }
 265 
 266 }