1 files changed, 278 insertions, 0 deletions
diff --git a/Source/WebCore/websockets/WebSocketExtensionDispatcher.cpp b/Source/WebCore/websockets/WebSocketExtensionDispatcher.cpp
new file mode 100644
index 000000000..7c592ad1b
--- /dev/null
+++ b/Source/WebCore/websockets/WebSocketExtensionDispatcher.cpp
@@ -0,0 +1,278 @@
+/*
+ * Copyright (C) 2012 Google Inc.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+
+#if ENABLE(WEB_SOCKETS)
+
+#include "WebSocketExtensionDispatcher.h"
+
+#include <wtf/ASCIICType.h>
+#include <wtf/HashMap.h>
+#include <wtf/text/CString.h>
+#include <wtf/text/StringHash.h>
+
+namespace WebCore {
+
+class ExtensionParser {
+public:
+    ExtensionParser(const char* start, const char* end)
+        : m_current(start)
+        , m_end(end)
+    {
+    }
+    bool finished();
+    bool parsedSuccessfully();
+    const String& currentToken() { return m_currentToken; }
+
+    // The following member functions basically follow the grammer defined
+    // in Section 2.2 of RFC 2616.
+    bool consumeToken();
+    bool consumeQuotedString();
+    bool consumeQuotedStringOrToken();
+    bool consumeCharacter(char);
+
+private:
+    void skipSpaces();
+
+    const char* m_current;
+    const char* m_end;
+    String m_currentToken;
+};
+
+bool ExtensionParser::finished()
+{
+    return m_current >= m_end;
+}
+
+bool ExtensionParser::parsedSuccessfully()
+{
+    return m_current == m_end;
+}
+
+static bool isSeparator(char character)
+{
+    static const char* separatorCharacters = "()<>@,;:\\\"/[]?={} \t";
+    const char* p = strchr(separatorCharacters, character);
+    return p && *p;
+}
+
+void ExtensionParser::skipSpaces()
+{
+    while (m_current < m_end && (*m_current == ' ' || *m_current == '\t'))
+        ++m_current;
+}
+
+bool ExtensionParser::consumeToken()
+{
+    skipSpaces();
+    const char* start = m_current;
+    while (m_current < m_end && isASCIIPrintable(*m_current) && !isSeparator(*m_current))
+        ++m_current;
+    if (start < m_current) {
+        m_currentToken = String(start, m_current - start);
+        return true;
+    }
+    return false;
+}
+
+bool ExtensionParser::consumeQuotedString()
+{
+    skipSpaces();
+    if (m_current >= m_end || *m_current != '"')
+        return false;
+
+    Vector<char> buffer;
+    ++m_current;
+    while (m_current < m_end && *m_current != '"') {
+        if (*m_current == '\\' && ++m_current >= m_end)
+            return false;
+        buffer.append(*m_current);
+        ++m_current;
+    }
+    if (m_current >= m_end || *m_current != '"')
+        return false;
+    m_currentToken = String::fromUTF8(buffer.data(), buffer.size());
+    ++m_current;
+    return true;
+}
+
+bool ExtensionParser::consumeQuotedStringOrToken()
+{
+    // This is ok because consumeQuotedString() doesn't update m_current or
+    // makes it same as m_end on failure.
+    return consumeQuotedString() || consumeToken();
+}
+
+bool ExtensionParser::consumeCharacter(char character)
+{
+    skipSpaces();
+    if (m_current < m_end && *m_current == character) {
+        ++m_current;
+        return true;
+    }
+    return false;
+}
+
+void WebSocketExtensionDispatcher::reset()
+{
+    m_processors.clear();
+}
+
+void WebSocketExtensionDispatcher::addProcessor(PassOwnPtr<WebSocketExtensionProcessor> processor)
+{
+    for (size_t i = 0; i < m_processors.size(); ++i) {
+        if (m_processors[i]->extensionToken() == processor->extensionToken())
+            return;
+    }
+    ASSERT(processor->handshakeString().length());
+    ASSERT(!processor->handshakeString().contains('\n'));
+    ASSERT(!processor->handshakeString().contains(static_cast<UChar>('\0')));
+    m_processors.append(processor);
+}
+
+const String WebSocketExtensionDispatcher::createHeaderValue() const
+{
+    size_t numProcessors = m_processors.size();
+    if (!numProcessors)
+        return String();
+
+    StringBuilder builder;
+    builder.append(m_processors[0]->handshakeString());
+    for (size_t i = 1; i < numProcessors; ++i) {
+        builder.append(", ");
+        builder.append(m_processors[i]->handshakeString());
+    }
+    return builder.toString();
+}
+
+void WebSocketExtensionDispatcher::appendAcceptedExtension(const String& extensionToken, HashMap<String, String>& extensionParameters)
+{
+    if (!m_acceptedExtensionsBuilder.isEmpty())
+        m_acceptedExtensionsBuilder.append(", ");
+    m_acceptedExtensionsBuilder.append(extensionToken);
+    // FIXME: Should use ListHashSet to keep the order of the parameters.
+    for (HashMap<String, String>::const_iterator iterator = extensionParameters.begin(); iterator != extensionParameters.end(); ++iterator) {
+        m_acceptedExtensionsBuilder.append("; ");
+        m_acceptedExtensionsBuilder.append(iterator->first);
+        if (!iterator->second.isNull()) {
+            m_acceptedExtensionsBuilder.append("=");
+            m_acceptedExtensionsBuilder.append(iterator->second);
+        }
+    }
+}
+
+void WebSocketExtensionDispatcher::fail(const String& reason)
+{
+    m_failureReason = reason;
+    m_acceptedExtensionsBuilder.clear();
+}
+
+bool WebSocketExtensionDispatcher::processHeaderValue(const String& headerValue)
+{
+    if (!headerValue.length())
+        return true;
+
+    // If we don't send Sec-WebSocket-Extensions header, the server should not return the header.
+    if (!m_processors.size()) {
+        fail("Received unexpected Sec-WebSocket-Extensions header");
+        return false;
+    }
+
+    const CString headerValueData = headerValue.utf8();
+    ExtensionParser parser(headerValueData.data(), headerValueData.data() + headerValueData.length());
+    while (!parser.finished()) {
+        // Parse extension-token.
+        if (!parser.consumeToken()) {
+            fail("Sec-WebSocket-Extensions header is invalid");
+            return false;
+        }
+        String extensionToken = parser.currentToken();
+
+        // Parse extension-parameters if exists.
+        HashMap<String, String> extensionParameters;
+        while (parser.consumeCharacter(';')) {
+            if (!parser.consumeToken()) {
+                fail("Sec-WebSocket-Extensions header is invalid");
+                return false;
+            }
+
+            String parameterToken = parser.currentToken();
+            if (parser.consumeCharacter('=')) {
+                if (parser.consumeQuotedStringOrToken())
+                    extensionParameters.add(parameterToken, parser.currentToken());
+                else {
+                    fail("Sec-WebSocket-Extensions header is invalid");
+                    return false;
+                }
+            } else
+                extensionParameters.add(parameterToken, String());
+        }
+        if (!parser.finished() && !parser.consumeCharacter(',')) {
+            fail("Sec-WebSocket-Extensions header is invalid");
+            return false;
+        }
+
+        size_t index;
+        for (index = 0; index < m_processors.size(); ++index) {
+            WebSocketExtensionProcessor* processor = m_processors[index].get();
+            if (extensionToken == processor->extensionToken()) {
+                if (processor->processResponse(extensionParameters)) {
+                    appendAcceptedExtension(extensionToken, extensionParameters);
+                    break;
+                }
+                fail(processor->failureReason());
+                return false;
+            }
+        }
+        // There is no extension which can process the response.
+        if (index == m_processors.size()) {
+            fail("Received unexpected extension: " + extensionToken);
+            return false;
+        }
+    }
+    return parser.parsedSuccessfully();
+}
+
+String WebSocketExtensionDispatcher::acceptedExtensions() const
+{
+    if (m_acceptedExtensionsBuilder.isEmpty())
+        return String();
+    return m_acceptedExtensionsBuilder.toStringPreserveCapacity();
+}
+
+String WebSocketExtensionDispatcher::failureReason() const
+{
+    return m_failureReason;
+}
+
+} // namespace WebCore
+
+#endif // ENABLE(WEB_SOCKETS)