1/*
2 * Copyright (C) 2012 Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met:
7 *
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 * * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include "config.h"
32
33#include "WebSocketExtensionDispatcher.h"
34#include "WebSocketExtensionParser.h"
35#include <wtf/ASCIICType.h>
36#include <wtf/HashMap.h>
37#include <wtf/text/CString.h>
38#include <wtf/text/StringHash.h>
39
40namespace WebCore {
41
42void WebSocketExtensionDispatcher::reset()
43{
44 m_processors.clear();
45}
46
47void WebSocketExtensionDispatcher::addProcessor(std::unique_ptr<WebSocketExtensionProcessor> processor)
48{
49 for (auto& extensionProcessor : m_processors) {
50 if (extensionProcessor->extensionToken() == processor->extensionToken())
51 return;
52 }
53 ASSERT(processor->handshakeString().length());
54 ASSERT(!processor->handshakeString().contains('\n'));
55 ASSERT(!processor->handshakeString().contains(static_cast<UChar>('\0')));
56 m_processors.append(WTFMove(processor));
57}
58
59const String WebSocketExtensionDispatcher::createHeaderValue() const
60{
61 size_t numProcessors = m_processors.size();
62 if (!numProcessors)
63 return String();
64
65 StringBuilder builder;
66 builder.append(m_processors[0]->handshakeString());
67 for (size_t i = 1; i < numProcessors; ++i) {
68 builder.appendLiteral(", ");
69 builder.append(m_processors[i]->handshakeString());
70 }
71 return builder.toString();
72}
73
74void WebSocketExtensionDispatcher::appendAcceptedExtension(const String& extensionToken, HashMap<String, String>& extensionParameters)
75{
76 if (!m_acceptedExtensionsBuilder.isEmpty())
77 m_acceptedExtensionsBuilder.appendLiteral(", ");
78 m_acceptedExtensionsBuilder.append(extensionToken);
79 // FIXME: Should use ListHashSet to keep the order of the parameters.
80 for (auto& parameter : extensionParameters) {
81 m_acceptedExtensionsBuilder.appendLiteral("; ");
82 m_acceptedExtensionsBuilder.append(parameter.key);
83 if (!parameter.value.isNull()) {
84 m_acceptedExtensionsBuilder.append('=');
85 m_acceptedExtensionsBuilder.append(parameter.value);
86 }
87 }
88}
89
90void WebSocketExtensionDispatcher::fail(const String& reason)
91{
92 m_failureReason = reason;
93 m_acceptedExtensionsBuilder.clear();
94}
95
96bool WebSocketExtensionDispatcher::processHeaderValue(const String& headerValue)
97{
98 if (!headerValue.length())
99 return true;
100
101 // If we don't send Sec-WebSocket-Extensions header, the server should not return the header.
102 if (!m_processors.size()) {
103 fail("Received unexpected Sec-WebSocket-Extensions header");
104 return false;
105 }
106
107 const CString headerValueData = headerValue.utf8();
108 WebSocketExtensionParser parser(headerValueData.data(), headerValueData.data() + headerValueData.length());
109 while (!parser.finished()) {
110 String extensionToken;
111 HashMap<String, String> extensionParameters;
112 if (!parser.parseExtension(extensionToken, extensionParameters)) {
113 fail("Sec-WebSocket-Extensions header is invalid");
114 return false;
115 }
116
117 size_t index = 0;
118 for (auto& processor : m_processors) {
119 if (extensionToken == processor->extensionToken()) {
120 if (processor->processResponse(extensionParameters)) {
121 appendAcceptedExtension(extensionToken, extensionParameters);
122 break;
123 }
124 fail(processor->failureReason());
125 return false;
126 }
127 ++index;
128 }
129 // There is no extension which can process the response.
130 if (index == m_processors.size()) {
131 fail("Received unexpected extension: " + extensionToken);
132 return false;
133 }
134 }
135 return parser.parsedSuccessfully();
136}
137
138String WebSocketExtensionDispatcher::acceptedExtensions() const
139{
140 if (m_acceptedExtensionsBuilder.isEmpty())
141 return String();
142 return m_acceptedExtensionsBuilder.toStringPreserveCapacity();
143}
144
145String WebSocketExtensionDispatcher::failureReason() const
146{
147 return m_failureReason;
148}
149
150} // namespace WebCore
151