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#include "WebSocketDeflateFramer.h"
33
34#include <wtf/HashMap.h>
35#include <wtf/text/StringHash.h>
36#include <wtf/text/WTFString.h>
37
38namespace WebCore {
39
40class WebSocketExtensionDeflateFrame : public WebSocketExtensionProcessor {
41 WTF_MAKE_FAST_ALLOCATED;
42public:
43 explicit WebSocketExtensionDeflateFrame(WebSocketDeflateFramer*);
44 virtual ~WebSocketExtensionDeflateFrame() = default;
45
46 String handshakeString() override;
47 bool processResponse(const HashMap<String, String>&) override;
48 String failureReason() override { return m_failureReason; }
49
50private:
51 WebSocketDeflateFramer* m_framer;
52 bool m_responseProcessed;
53 String m_failureReason;
54};
55
56// FXIME: Remove vendor prefix after the specification matured.
57WebSocketExtensionDeflateFrame::WebSocketExtensionDeflateFrame(WebSocketDeflateFramer* framer)
58 : WebSocketExtensionProcessor("x-webkit-deflate-frame")
59 , m_framer(framer)
60 , m_responseProcessed(false)
61{
62 ASSERT(m_framer);
63}
64
65String WebSocketExtensionDeflateFrame::handshakeString()
66{
67 return extensionToken(); // No parameter
68}
69
70bool WebSocketExtensionDeflateFrame::processResponse(const HashMap<String, String>& serverParameters)
71{
72#if USE(ZLIB)
73 if (m_responseProcessed) {
74 m_failureReason = "Received duplicate deflate-frame response";
75 return false;
76 }
77 m_responseProcessed = true;
78
79 unsigned expectedNumParameters = 0;
80 int windowBits = 15;
81 HashMap<String, String>::const_iterator parameter = serverParameters.find("max_window_bits");
82 if (parameter != serverParameters.end()) {
83 windowBits = parameter->value.toInt();
84 if (windowBits < 8 || windowBits > 15) {
85 m_failureReason = "Received invalid max_window_bits parameter";
86 return false;
87 }
88 expectedNumParameters++;
89 }
90
91 WebSocketDeflater::ContextTakeOverMode mode = WebSocketDeflater::TakeOverContext;
92 parameter = serverParameters.find("no_context_takeover");
93 if (parameter != serverParameters.end()) {
94 if (!parameter->value.isNull()) {
95 m_failureReason = "Received invalid no_context_takeover parameter";
96 return false;
97 }
98 mode = WebSocketDeflater::DoNotTakeOverContext;
99 expectedNumParameters++;
100 }
101
102 if (expectedNumParameters != serverParameters.size()) {
103 m_failureReason = "Received unexpected deflate-frame parameter";
104 return false;
105 }
106
107 m_framer->enableDeflate(windowBits, mode);
108 return true;
109#else
110 ASSERT_NOT_REACHED();
111 return false;
112#endif
113}
114
115DeflateResultHolder::DeflateResultHolder(WebSocketDeflateFramer* framer)
116 : m_framer(framer)
117 , m_succeeded(true)
118{
119 ASSERT(m_framer);
120}
121
122DeflateResultHolder::~DeflateResultHolder()
123{
124 m_framer->resetDeflateContext();
125}
126
127void DeflateResultHolder::fail(const String& failureReason)
128{
129 m_succeeded = false;
130 m_failureReason = failureReason;
131}
132
133InflateResultHolder::InflateResultHolder(WebSocketDeflateFramer* framer)
134 : m_framer(framer)
135 , m_succeeded(true)
136{
137 ASSERT(m_framer);
138}
139
140InflateResultHolder::~InflateResultHolder()
141{
142 m_framer->resetInflateContext();
143}
144
145void InflateResultHolder::fail(const String& failureReason)
146{
147 m_succeeded = false;
148 m_failureReason = failureReason;
149}
150
151WebSocketDeflateFramer::WebSocketDeflateFramer()
152 : m_enabled(false)
153{
154}
155
156std::unique_ptr<WebSocketExtensionProcessor> WebSocketDeflateFramer::createExtensionProcessor()
157{
158 return std::make_unique<WebSocketExtensionDeflateFrame>(this);
159}
160
161bool WebSocketDeflateFramer::canDeflate() const
162{
163#if USE(ZLIB)
164 return true;
165#else
166 return false;
167#endif
168}
169
170#if USE(ZLIB)
171void WebSocketDeflateFramer::enableDeflate(int windowBits, WebSocketDeflater::ContextTakeOverMode mode)
172{
173 m_deflater = std::make_unique<WebSocketDeflater>(windowBits, mode);
174 m_inflater = std::make_unique<WebSocketInflater>();
175 if (!m_deflater->initialize() || !m_inflater->initialize()) {
176 m_deflater = nullptr;
177 m_inflater = nullptr;
178 return;
179 }
180 m_enabled = true;
181}
182#endif
183
184std::unique_ptr<DeflateResultHolder> WebSocketDeflateFramer::deflate(WebSocketFrame& frame)
185{
186#if USE(ZLIB)
187 auto result = std::make_unique<DeflateResultHolder>(this);
188 if (!enabled() || !WebSocketFrame::isNonControlOpCode(frame.opCode) || !frame.payloadLength)
189 return result;
190 if (!m_deflater->addBytes(frame.payload, frame.payloadLength) || !m_deflater->finish()) {
191 result->fail("Failed to compress frame");
192 return result;
193 }
194 frame.compress = true;
195 frame.payload = m_deflater->data();
196 frame.payloadLength = m_deflater->size();
197 return result;
198#else
199 return std::make_unique<DeflateResultHolder>(this);
200#endif
201}
202
203void WebSocketDeflateFramer::resetDeflateContext()
204{
205#if USE(ZLIB)
206 if (m_deflater)
207 m_deflater->reset();
208#endif
209}
210
211std::unique_ptr<InflateResultHolder> WebSocketDeflateFramer::inflate(WebSocketFrame& frame)
212{
213 auto result = std::make_unique<InflateResultHolder>(this);
214 if (!enabled() && frame.compress) {
215 result->fail("Compressed bit must be 0 if no negotiated deflate-frame extension");
216 return result;
217 }
218#if USE(ZLIB)
219 if (!frame.compress)
220 return result;
221 if (!WebSocketFrame::isNonControlOpCode(frame.opCode)) {
222 result->fail("Received unexpected compressed frame");
223 return result;
224 }
225 if (!m_inflater->addBytes(frame.payload, frame.payloadLength) || !m_inflater->finish()) {
226 result->fail("Failed to decompress frame");
227 return result;
228 }
229 frame.compress = false;
230 frame.payload = m_inflater->data();
231 frame.payloadLength = m_inflater->size();
232 return result;
233#else
234 return result;
235#endif
236}
237
238void WebSocketDeflateFramer::resetInflateContext()
239{
240#if USE(ZLIB)
241 if (m_inflater)
242 m_inflater->reset();
243#endif
244}
245
246void WebSocketDeflateFramer::didFail()
247{
248 resetDeflateContext();
249 resetInflateContext();
250}
251
252} // namespace WebCore
253