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
67 if (LOGGER.isDebugEnabled()) {
68 LOGGER.debug("Event queue CLEARED");
69 }
70 }
71 }
72
73 /**
74 * Event is enqueued only if necessary :
75 * - socks proxies do not need the reconnection feature so events are always
76 * forwarded for these.
77 * - http proxies events will be enqueued while handshake has not been completed
78 * or until connection was closed.
79 * If connection was prematurely closed previous events are discarded and only the
80 * session closed is delivered.
81 *
82 * @param evt the event to enqueue
83 */
84 public void enqueueEventIfNecessary(final IoSessionEvent evt) {
85 if (LOGGER.isDebugEnabled()) {
86 LOGGER.debug("??? >> Enqueue {}", evt);
87 }
88
89 if (proxyIoSession.getRequest() instanceof SocksProxyRequest) {
90 // No reconnection used
91 evt.deliverEvent();
92
93 return;
94 }
95
96 if (proxyIoSession.getHandler().isHandshakeComplete()) {
97 evt.deliverEvent();
98 } else {
99 if (evt.getType() == IoSessionEventType.CLOSED) {
100 if (proxyIoSession.isAuthenticationFailed()) {
101 proxyIoSession.getConnector().cancelConnectFuture();
102 discardSessionQueueEvents();
103 evt.deliverEvent();
104 } else {
105 discardSessionQueueEvents();
106 }
107 } else if (evt.getType() == IoSessionEventType.OPENED) {
108 // Enqueue event cause it will not reach IoHandler but deliver it to enable
109 // session creation.
110 enqueueSessionEvent(evt);
111 evt.deliverEvent();
112 } else {
113 enqueueSessionEvent(evt);
114 }
115 }
116 }
117
118 /**
119 * Send any session event which were queued while waiting for handshaking to complete.
120 *
121 * Please note this is an internal method. DO NOT USE it in your code.
122 *
123 * @throws Exception If something went wrong while flushing the pending events
124 */
125 public void flushPendingSessionEvents() throws Exception {
126 synchronized (sessionEventsQueue) {
127 IoSessionEvent evt;
128
129 while ((evt = sessionEventsQueue.poll()) != null) {
130 if (LOGGER.isDebugEnabled()) {
131 LOGGER.debug(" Flushing buffered event: {}", evt);
132 }
133
134 evt.deliverEvent();
135 }
136 }
137 }
138
139 /**
140 * Enqueue an event to be delivered once handshaking is complete.
141 *
142 * @param evt the session event to enqueue
143 */
144 private void enqueueSessionEvent(final IoSessionEvent evt) {
145 synchronized (sessionEventsQueue) {
146 if (LOGGER.isDebugEnabled()) {
147 LOGGER.debug("Enqueuing event: {}", evt);
148 }
149
150 sessionEventsQueue.offer(evt);
151 }
152 }
153 }