InetAddressUtil


1   /*
2    * Copyright  1999-2004 The Apache Software Foundation
3    *
4    *  Licensed under the Apache License, Version 2.0 (the "License");
5    *  you may not use this file except in compliance with the License.
6    *  You may obtain a copy of the License at
7    *
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    *
10   *  Unless required by applicable law or agreed to in writing, software
11   *  distributed under the License is distributed on an "AS IS" BASIS,
12   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   *  See the License for the specific language governing permissions and
14   *  limitations under the License.
15   *
16   */
17  
18  /* $Id: InetAddressUtil.java 43095 2004-06-28 08:52:33Z andreas $  */
19  
20  package org.apache.lenya.net;
21  
22  import java.net.InetAddress  ;
23  import java.net.UnknownHostException  ;
24  
25  import org.apache.log4j.Category;
26  
27  /**
28   * A utility class for InetAddress. Also see http://jodies.de/ipcalc
29   */
30  public class InetAddressUtil {
31  
32      private static final Category log = Category.getInstance(InetAddressUtil.class);
33  
34      /**
35       * Ctor.
36       */
37      private InetAddressUtil() {
38      }
39  
40      /**
41       * Checks if a subnet contains a specific IP address.
42       * 
43       * @param network The network address.
44       * @param netmask The subnet mask.
45       * @param ip The IP address to check.
46       * @return A boolean value.
47       */
48      public static boolean contains(InetAddress   network, InetAddress   netmask, InetAddress   ip) {
49          if(log.isDebugEnabled()) {
50              log.debug("=======================================");
51              log.debug("Checking IP address: " + ip + " in " + network + " / " + netmask);
52          }
53          
54          byte[] networkBytes = network.getAddress();
55          byte[] netmaskBytes = netmask.getAddress();
56          byte[] ipBytes = ip.getAddress();
57          
58          /* check IPv4/v6-compatibility or parameters: */
59          if(networkBytes.length != netmaskBytes.length
60              || netmaskBytes.length != ipBytes.length)
61          {
62              /*
63               * FIXME: If network and netmask have the same size
64               * should already be checked whenever
65               * org.apache.lenya.ac.(impl.Abstract)IPRange
66               * is set. In that case the user should be notified
67               * of this configuration-error instead of silently
68               * accepting the buggy IPRange as one not matching
69               * any host!
70               * (Note that changes to the public API of IPRange
71               * and other classes would be necessary to fix this
72               * problem. This method and therefore this whole
73               * class would probably be obsolete in that case.)
74               */
75              if(log.isDebugEnabled()) {
76                  log.debug
77                      ("Network address " + network + ", subnet mask "
78                       + netmask + " and/or host address " + ip
79                       + " have different sizes! (return false ...)");
80                  log.debug("=======================================");
81              }
82              return false;
83          }
84          
85          /* Check if the masked network and ip addresses match: */
86          for(int i=0; i<netmaskBytes.length; i++) {
87              int mask = netmaskBytes[i] & 0xff;
88              if((networkBytes[i] & mask) != (ipBytes[i] & mask)) {
89                  if(log.isDebugEnabled()) {
90                      log.debug
91                          (ip + " is not in " + network + " / " + netmask);
92                      log.debug("=======================================");
93                  }
94                  return false;
95              }
96          }
97          if(log.isDebugEnabled()) {
98              log.debug
99                  (ip + " is in " + network + " / " + netmask);
100             log.debug("=======================================");
101         }
102         return true;
103     }
104 
105     /**
106      * Returns the n-th part of an InetAddress.
107      * @param ip The address.
108      * @param partNumber The number of the part.
109      * @return An integer value.
110      * 
111      * @deprecated This was an internal implementation detail of the
112      *      method {@link #contains} and should never have been
113      *      made public. (And it's inefficient and unnecessary
114      *      too, as well as broken for IPv6. ;-)
115      *      Use <code>ip.getAddress()[partNumber]</code>
116      *      instead.
117      */
118     public static int getClassPart(InetAddress   ip, int partNumber) {
119         String  [] parts = ip.getHostAddress().split("\\.");
120         String   part = parts[partNumber];
121         return new Integer  (part).intValue();
122     }
123 
124     /**
125      * Check netmask, e.g. 255.255.255.240 is fine, 255.255.240.16 is illegal (needs to be 255.255.240.0)
126      * @param netmask The netmask address.
127      * @return An integer value. -1 if illegal netmask, otherwise 0, 1, 2, 3
128      * 
129      * @deprecated This was an internal implementation detail of the
130      *      method {@link #contains} and should never have been
131      *      made public. Furthermore it's broken for IPv6.
132      *      (However, there is no real replacement. If you
133      *      need this functionality, you should rewrite it
134      *      yourself.)
135      */
136     public static int checkNetmask(InetAddress   netmask) {
137         String  [] parts = netmask.getHostAddress().split("\\.");
138         Integer  [] numbers = new Integer  [4];
139         for (int i = 0; i < 4; i++) {
140             numbers[i] = new Integer  (parts[i]);
141         }
142 
143         for (int i = 0; i < 4; i++) {
144             log.debug(".checkNetmask(): Check part: " + numbers[i]);
145             if (0 <= numbers[i].intValue() && numbers[i].intValue() <= 255) {
146                 if (numbers[i].intValue() != 255) {
147                     for (int k = i + 1; k < 4; k++) {
148                         if (numbers[k].intValue() != 0) {
149                             log.error(".checkNetmask(): Illegal Netmask: " + netmask);
150                             return -1;
151                         }
152                     }
153                     return i;
154                 } else {
155                     continue;
156                 }
157             } else {
158                 // FIXME: This check not really be necessary because java.net.UnknownHostException should be thrown long time before
159                 log.error(".checkNetmask(): Illegal Netmask: " + netmask);
160                 return -1;
161             }
162         }
163         if (log.isDebugEnabled()) {
164             log.debug("All parts equal 255: " + netmask);
165         }
166         return 3;
167     }
168 
169     /**
170      * Converts a string to an IP addres.
171      * @param string The IP address, represented by a string.
172      * @return An InetAddress object.
173      * @throws AccessControlException when something went wrong.
174      * 
175      * @deprecated This was an internal implementation detail of the
176      *      method {@link #contains} and should never have been
177      *      made public. (And it's unnecessary
178      *      too, as well as broken for IPv6. ;-)
179      *      Use <code>InetAddress.getByName(string)</code>
180      *      instead.
181      */
182     public static InetAddress   getAddress(String   string) throws UnknownHostException   {
183         String  [] strings = string.split("\\.");
184 
185         InetAddress   address;
186         byte[] numbers = new byte[strings.length];
187         for (int i = 0; i < strings.length; i++) {
188             int number = Integer.parseInt(strings[i]);
189             if (number > 127) {
190                 number = number - 256;
191             }
192             numbers[i] = (byte) number;
193         }
194 
195         address = InetAddress.getByAddress(numbers);
196         return address;
197     }
198 
199 }
200
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