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.proxy.event;
21
22 import java.util.LinkedList;
23 import java.util.Queue;
24
25 import org.apache.mina.proxy.handlers.socks.SocksProxyRequest;
26 import org.apache.mina.proxy.session.ProxyIoSession;
27 import org.slf4j.Logger;
28 import org.slf4j.LoggerFactory;
29
30 /**
31 * IoSessionEventQueue.java - Queue that contains filtered session events
32 * while handshake isn't done.
33 *
34 * @author <a href="http://mina.apache.org">Apache MINA Project</a>
35 * @since MINA 2.0.0-M3
36 */
37 public class IoSessionEventQueue {
38 private static final Logger logger = LoggerFactory.getLogger(IoSessionEventQueue.class);
39
40 /**
41 * The proxy session object.
42 */
43 private ProxyIoSession proxyIoSession;
44
45 /**
46 * Queue of session events which occurred before the proxy handshake had completed.
47 */
48 private Queue<IoSessionEvent> sessionEventsQueue = new LinkedList<>();
49
50 /**
51 * Creates a new proxyIoSession instance
52 *
53 * @param proxyIoSession The proxy session instance
54 */
55 public IoSessionEventQueue(ProxyIoSession proxyIoSession) {
56 this.proxyIoSession = proxyIoSession;
57 }
58
59 /**
60 * Discard all events from the queue.
61 */
62 private void discardSessionQueueEvents() {
63 synchronized (sessionEventsQueue) {
64 // Free queue
65 sessionEventsQueue.clear();
66 logger.debug("Event queue CLEARED");
67 }
68 }
69
70 /**
71 * Event is enqueued only if necessary :
72 * - socks proxies do not need the reconnection feature so events are always
73 * forwarded for these.
74 * - http proxies events will be enqueued while handshake has not been completed
75 * or until connection was closed.
76 * If connection was prematurely closed previous events are discarded and only the
77 * session closed is delivered.
78 *
79 * @param evt the event to enqueue
80 */
81 public void enqueueEventIfNecessary(final IoSessionEvent evt) {
82 logger.debug("??? >> Enqueue {}", evt);
83
84 if (proxyIoSession.getRequest() instanceof SocksProxyRequest) {
85 // No reconnection used
86 evt.deliverEvent();
87
88 return;
89 }
90
91 if (proxyIoSession.getHandler().isHandshakeComplete()) {
92 evt.deliverEvent();
93 } else {
94 if (evt.getType() == IoSessionEventType.CLOSED) {
95 if (proxyIoSession.isAuthenticationFailed()) {
96 proxyIoSession.getConnector().cancelConnectFuture();
97 discardSessionQueueEvents();
98 evt.deliverEvent();
99 } else {
100 discardSessionQueueEvents();
101 }
102 } else if (evt.getType() == IoSessionEventType.OPENED) {
103 // Enqueue event cause it will not reach IoHandler but deliver it to enable
104 // session creation.
105 enqueueSessionEvent(evt);
106 evt.deliverEvent();
107 } else {
108 enqueueSessionEvent(evt);
109 }
110 }
111 }
112
113 /**
114 * Send any session event which were queued while waiting for handshaking to complete.
115 *
116 * Please note this is an internal method. DO NOT USE it in your code.
117 *
118 * @throws Exception If something went wrong while flushing the pending events
119 */
120 public void flushPendingSessionEvents() throws Exception {
121 synchronized (sessionEventsQueue) {
122 IoSessionEvent evt;
123
124 while ((evt = sessionEventsQueue.poll()) != null) {
125 logger.debug(" Flushing buffered event: {}", evt);
126 evt.deliverEvent();
127 }
128 }
129 }
130
131 /**
132 * Enqueue an event to be delivered once handshaking is complete.
133 *
134 * @param evt the session event to enqueue
135 */
136 private void enqueueSessionEvent(final IoSessionEvent evt) {
137 synchronized (sessionEventsQueue) {
138 logger.debug("Enqueuing event: {}", evt);
139 sessionEventsQueue.offer(evt);
140 }
141 }
142 }