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    1   /*
    2    *  Licensed to the Apache Software Foundation (ASF) under one
    3    *  or more contributor license agreements.  See the NOTICE file
    4    *  distributed with this work for additional information
    5    *  regarding copyright ownership.  The ASF licenses this file
    6    *  to you under the Apache License, Version 2.0 (the
    7    *  "License"); you may not use this file except in compliance
    8    *  with the License.  You may obtain a copy of the License at
    9    *
    10   *    http://www.apache.org/licenses/LICENSE-2.0
    11   *
    12   *  Unless required by applicable law or agreed to in writing,
    13   *  software distributed under the License is distributed on an
    14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    15   *  KIND, either express or implied.  See the License for the
    16   *  specific language governing permissions and limitations
    17   *  under the License.
    18   *
    19   */
    20  package org.apache.mina.filter;
    21
    22  import java.net.InetAddress;
    23  import java.net.InetSocketAddress;
    24  import java.net.SocketAddress;
    25  import java.util.Collection;
    26  import java.util.Set;
    27  import java.util.concurrent.CopyOnWriteArraySet;
    28
    29  import org.apache.mina.common.IdleStatus;
    30  import org.apache.mina.common.IoFilter;
    31  import org.apache.mina.common.IoFilterAdapter;
    32  import org.apache.mina.common.IoSession;
    33  import org.apache.mina.util.SessionLog;
    34
    35  /**
    36   * A {@link IoFilter} which blocks connections from blacklisted remote
    37   * address.
    38   *
    39   * @author The Apache Directory Project (mina-dev@directory.apache.org)
    40   * @version $Rev: 587373 $, $Date: 2007-10-23 11:54:05 +0900 (Tue, 23 Oct 2007) $
    41   */
    42  public class BlacklistFilter extends IoFilterAdapter {
    43      private final Set<InetAddress> blacklist = new CopyOnWriteArraySet<InetAddress>();
    44
    45      /**
    46       * Sets the addresses to be blacklisted.
    47       *
    48       * NOTE: this call will remove any previously blacklisted addresses.
    49       *
    50       * @param addresses an array of addresses to be blacklisted.
    51       */
    52      public void setBlacklist(InetAddress... addresses) {
    53          if (addresses == null)
    54              throw new NullPointerException("addresses");
    55          blacklist.clear();
    56          for (int i = 0; i < addresses.length; i++) {
    57              InetAddress addr = addresses[i];
    58              block(addr, "addresses[" + i + ']');
    59          }
    60      }
    61
    62      /**
    63       * Sets the addresses to be blacklisted.
    64       *
    65       * NOTE: this call will remove any previously blacklisted addresses.
    66       *
    67       * @param addresses a collection of InetAddress objects representing the
    68       *        addresses to be blacklisted.
    69       * @throws IllegalArgumentException if the specified collections contains
    70       *         non-{@link InetAddress} objects.
    71       */
    72      public void setBlacklist(Collection<InetAddress> addresses) {
    73          if (addresses == null)
    74              throw new NullPointerException("addresses");
    75
    76          InetAddress[] inetAddresses = new InetAddress[addresses.size()];
    77          try {
    78              setBlacklist(addresses.toArray(inetAddresses));
    79          } catch (ArrayStoreException ase) {
    80              IllegalArgumentException iae = new IllegalArgumentException(
    81                      "Collection of addresses must contain only InetAddress instances.");
    82              iae.initCause(ase);
    83              throw iae;
    84          }
    85      }
    86
    87      /**
    88       * Blocks the specified endpoint.
    89       */
    90      public void block(InetAddress address, String error_string) {
    91          if (address == null)
    92              throw new NullPointerException(error_string);
    93          blacklist.add(address);
    94      }
    95
    96      /**
    97       * Blocks the specified endpoint.
    98       */
    99      public void block(InetAddress address) {
    100         block(address, "address");
    101     }
    102
    103     /**
    104      * Unblocks the specified endpoint.
    105      */
    106     public void unblock(InetAddress address) {
    107         if (address == null)
    108             throw new NullPointerException("address");
    109         blacklist.remove(address);
    110     }
    111
    112     @Override
    113     public void sessionCreated(NextFilter nextFilter, IoSession session) {
    114         if (!isBlocked(session)) {
    115             // forward if not blocked
    116             nextFilter.sessionCreated(session);
    117         } else {
    118             blockSession(session);
    119         }
    120     }
    121
    122     @Override
    123     public void sessionOpened(NextFilter nextFilter, IoSession session)
    124             throws Exception {
    125         if (!isBlocked(session)) {
    126             // forward if not blocked
    127             nextFilter.sessionOpened(session);
    128         } else {
    129             blockSession(session);
    130         }
    131     }
    132
    133     @Override
    134     public void sessionClosed(NextFilter nextFilter, IoSession session)
    135             throws Exception {
    136         if (!isBlocked(session)) {
    137             // forward if not blocked
    138             nextFilter.sessionClosed(session);
    139         } else {
    140             blockSession(session);
    141         }
    142     }
    143
    144     @Override
    145     public void sessionIdle(NextFilter nextFilter, IoSession session,
    146             IdleStatus status) throws Exception {
    147         if (!isBlocked(session)) {
    148             // forward if not blocked
    149             nextFilter.sessionIdle(session, status);
    150         } else {
    151             blockSession(session);
    152         }
    153     }
    154
    155     @Override
    156     public void messageReceived(NextFilter nextFilter, IoSession session,
    157             Object message) {
    158         if (!isBlocked(session)) {
    159             // forward if not blocked
    160             nextFilter.messageReceived(session, message);
    161         } else {
    162             blockSession(session);
    163         }
    164     }
    165
    166     @Override
    167     public void messageSent(NextFilter nextFilter, IoSession session,
    168             Object message) throws Exception {
    169         if (!isBlocked(session)) {
    170             // forward if not blocked
    171             nextFilter.messageSent(session, message);
    172         } else {
    173             blockSession(session);
    174         }
    175     }
    176
    177     private void blockSession(IoSession session) {
    178         SessionLog.info(session, "Remote address in the blacklist; closing.");
    179         session.close();
    180     }
    181
    182     private boolean isBlocked(IoSession session) {
    183         SocketAddress remoteAddress = session.getRemoteAddress();
    184         if (remoteAddress instanceof InetSocketAddress) {
    185             if (blacklist.contains(((InetSocketAddress) remoteAddress)
    186                     .getAddress())) {
    187                 return true;
    188             }
    189         }
    190
    191         return false;
    192     }
    193 }