1 /*
2 * Copyright 2012 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License,
5 * version 2.0 (the "License"); you may not use this file except in compliance
6 * with the License. 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, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations
14 * under the License.
15 */
16 package org.jboss.netty.handler.ipfilter;
17
18 import java.net.InetAddress;
19 import java.net.InetSocketAddress;
20 import java.util.concurrent.ConcurrentHashMap;
21 import java.util.concurrent.ConcurrentMap;
22
23 import org.jboss.netty.channel.ChannelEvent;
24 import org.jboss.netty.channel.ChannelHandler.Sharable;
25 import org.jboss.netty.channel.ChannelHandlerContext;
26 import org.jboss.netty.channel.ChannelState;
27 import org.jboss.netty.channel.ChannelStateEvent;
28
29 /**
30 * Handler that block any new connection if there are already a currently active
31 * channel connected with the same InetAddress (IP).<br>
32 * <br>
33 * <p/>
34 * Take care to not change isBlocked method except if you know what you are doing
35 * since it is used to test if the current closed connection is to be removed
36 * or not from the map of currently connected channel.
37 */
38 @Sharable
39 public class OneIpFilterHandler extends IpFilteringHandlerImpl {
40 /** HashMap of current remote connected InetAddress */
41 private final ConcurrentMap<InetAddress, Boolean> connectedSet = new ConcurrentHashMap<InetAddress, Boolean>();
42
43 @Override
44 protected boolean accept(ChannelHandlerContext ctx, ChannelEvent e, InetSocketAddress inetSocketAddress)
45 throws Exception {
46 InetAddress inetAddress = inetSocketAddress.getAddress();
47 if (connectedSet.containsKey(inetAddress)) {
48 return false;
49 }
50 connectedSet.put(inetAddress, Boolean.TRUE);
51 return true;
52 }
53
54 @Override
55 public void handleUpstream(ChannelHandlerContext ctx, ChannelEvent e) throws Exception {
56 super.handleUpstream(ctx, e);
57 // Try to remove entry from Map if already exists
58 if (e instanceof ChannelStateEvent) {
59 ChannelStateEvent evt = (ChannelStateEvent) e;
60 if (evt.getState() == ChannelState.CONNECTED) {
61 if (evt.getValue() == null) {
62 // DISCONNECTED but was this channel blocked or not
63 if (isBlocked(ctx)) {
64 // remove inetsocketaddress from set since this channel was not blocked before
65 InetSocketAddress inetSocketAddress = (InetSocketAddress) e.getChannel().getRemoteAddress();
66 connectedSet.remove(inetSocketAddress.getAddress());
67 }
68 }
69 }
70 }
71 }
72
73 }