1 /*
2 * Copyright (C) 2013 4th Line GmbH, Switzerland
3 *
4 * The contents of this file are subject to the terms of either the GNU
5 * Lesser General Public License Version 2 or later ("LGPL") or the
6 * Common Development and Distribution License Version 1 or later
7 * ("CDDL") (collectively, the "License"). You may not use this file
8 * except in compliance with the License. See LICENSE.txt for more
9 * information.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
14 */
15
16 package org.fourthline.cling.protocol.async;
17
18 import org.fourthline.cling.UpnpService;
19 import org.fourthline.cling.model.ValidationError;
20 import org.fourthline.cling.model.ValidationException;
21 import org.fourthline.cling.model.message.IncomingDatagramMessage;
22 import org.fourthline.cling.model.message.UpnpRequest;
23 import org.fourthline.cling.model.message.discovery.IncomingNotificationRequest;
24 import org.fourthline.cling.model.meta.RemoteDevice;
25 import org.fourthline.cling.model.meta.RemoteDeviceIdentity;
26 import org.fourthline.cling.model.types.UDN;
27 import org.fourthline.cling.protocol.ReceivingAsync;
28 import org.fourthline.cling.protocol.RetrieveRemoteDescriptors;
29 import org.fourthline.cling.transport.RouterException;
30
31 import java.util.logging.Logger;
32
33 /**
34 * Handles reception of notification messages.
35 * <p>
36 * First, the UDN is created from the received message.
37 * </p>
38 * <p>
39 * If an <em>ALIVE</em> message has been received, a new background process will be started
40 * running {@link org.fourthline.cling.protocol.RetrieveRemoteDescriptors}.
41 * </p>
42 * <p>
43 * If a <em>BYEBYE</em> message has been received, the device will be removed from the registry
44 * directly.
45 * </p>
46 * <p>
47 * The following was added to the UDA 1.1 spec (in 1.3), clarifying the handling of messages:
48 * </p>
49 * <p>
50 * "If a control point has received at least one 'byebye' message of a root device, embedded device, or
51 * service, then the control point can assume that all are no longer available."
52 * </p>
53 * <p>
54 * Of course, they contradict this a little later:
55 * </p>
56 * <p>
57 * "Only when all original advertisements of a root device, embedded device, and services have
58 * expired can a control point assume that they are no longer available."
59 * </p>
60 * <p>
61 * This could mean that even if we get 'byeby'e for the root device, we still have to assume that its services
62 * are available. That clearly makes no sense at all and I think it's just badly worded and relates to the
63 * previous sentence wich says "if you don't get byebye's, rely on the expiration timeout". It does not
64 * imply that a service or embedded device lives beyond its root device. It actually reinforces that we are
65 * free to ignore anything that happens as long as the root device is not gone with 'byebye' or has expired.
66 * In other words: There is no reason at all why SSDP sends dozens of messages for all embedded devices and
67 * services. The composite is the root device and the composite defines the lifecycle of all.
68 * </p>
69 *
70 * @author Christian Bauer
71 */
72 public class ReceivingNotification extends ReceivingAsync<IncomingNotificationRequest> {
73
74 final private static Logger log = Logger.getLogger(ReceivingNotification.class.getName());
75
76 public ReceivingNotification(UpnpService upnpService, IncomingDatagramMessage<UpnpRequest> inputMessage) {
77 super(upnpService, new IncomingNotificationRequest(inputMessage));
78 }
79
80 protected void execute() throws RouterException {
81
82 UDN udn = getInputMessage().getUDN();
83 if (udn == null) {
84 log.fine("Ignoring notification message without UDN: " + getInputMessage());
85 return;
86 }
87
88 RemoteDeviceIdentity rdIdentity = new RemoteDeviceIdentity(getInputMessage());
89 log.fine("Received device notification: " + rdIdentity);
90
91 RemoteDevice rd;
92 try {
93 rd = new RemoteDevice(rdIdentity);
94 } catch (ValidationException ex) {
95 log.warning("Validation errors of device during discovery: " + rdIdentity);
96 for (ValidationError validationError : ex.getErrors()) {
97 log.warning(validationError.toString());
98 }
99 return;
100 }
101
102 if (getInputMessage().isAliveMessage()) {
103
104 log.fine("Received device ALIVE advertisement, descriptor location is: " + rdIdentity.getDescriptorURL());
105
106 if (rdIdentity.getDescriptorURL() == null) {
107 log.finer("Ignoring message without location URL header: " + getInputMessage());
108 return;
109 }
110
111 if (rdIdentity.getMaxAgeSeconds() == null) {
112 log.finer("Ignoring message without max-age header: " + getInputMessage());
113 return;
114 }
115
116 if (getUpnpService().getRegistry().update(rdIdentity)) {
117 log.finer("Remote device was already known: " + udn);
118 return;
119 }
120
121 // Unfortunately, we always have to retrieve the descriptor because at this point we
122 // have no idea if it's a root or embedded device
123 getUpnpService().getConfiguration().getAsyncProtocolExecutor().execute(
124 new RetrieveRemoteDescriptors(getUpnpService(), rd)
125 );
126
127 } else if (getInputMessage().isByeByeMessage()) {
128
129 log.fine("Received device BYEBYE advertisement");
130 boolean removed = getUpnpService().getRegistry().removeDevice(rd);
131 if (removed) {
132 log.fine("Removed remote device from registry: " + rd);
133 }
134
135 } else {
136 log.finer("Ignoring unknown notification message: " + getInputMessage());
137 }
138
139 }
140
141
142 }