blob: a10950d0e41d72cda425284ee85d8b7183e263b3 [file] [log] [blame]
/*
* Copyright (C) 2011 Google Inc. All rights reserved.
* Copyright (C) 2015-2016 Apple 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"
#include "WebSocket.h"
#include "Blob.h"
#include "CloseEvent.h"
#include "ContentSecurityPolicy.h"
#include "DOMWindow.h"
#include "Document.h"
#include "Event.h"
#include "EventListener.h"
#include "EventNames.h"
#include "Frame.h"
#include "FrameLoader.h"
#include "FrameLoaderClient.h"
#include "Logging.h"
#include "MessageEvent.h"
#include "ResourceLoadObserver.h"
#include "ScriptController.h"
#include "ScriptExecutionContext.h"
#include "SecurityOrigin.h"
#include "SocketProvider.h"
#include "ThreadableWebSocketChannel.h"
#include "WebSocketChannel.h"
#include "WorkerGlobalScope.h"
#include "WorkerLoaderProxy.h"
#include "WorkerThread.h"
#include <JavaScriptCore/ArrayBuffer.h>
#include <JavaScriptCore/ArrayBufferView.h>
#include <JavaScriptCore/ScriptCallStack.h>
#include <wtf/HashSet.h>
#include <wtf/HexNumber.h>
#include <wtf/IsoMallocInlines.h>
#include <wtf/NeverDestroyed.h>
#include <wtf/RunLoop.h>
#include <wtf/StdLibExtras.h>
#include <wtf/text/CString.h>
#include <wtf/text/StringBuilder.h>
#if USE(WEB_THREAD)
#include "WebCoreThreadRun.h"
#endif
namespace WebCore {
WTF_MAKE_ISO_ALLOCATED_IMPL(WebSocket);
const size_t maxReasonSizeInBytes = 123;
static inline bool isValidProtocolCharacter(UChar character)
{
// Hybi-10 says "(Subprotocol string must consist of) characters in the range U+0021 to U+007E not including
// separator characters as defined in [RFC2616]."
const UChar minimumProtocolCharacter = '!'; // U+0021.
const UChar maximumProtocolCharacter = '~'; // U+007E.
return character >= minimumProtocolCharacter && character <= maximumProtocolCharacter
&& character != '"' && character != '(' && character != ')' && character != ',' && character != '/'
&& !(character >= ':' && character <= '@') // U+003A - U+0040 (':', ';', '<', '=', '>', '?', '@').
&& !(character >= '[' && character <= ']') // U+005B - U+005D ('[', '\\', ']').
&& character != '{' && character != '}';
}
static bool isValidProtocolString(StringView protocol)
{
if (protocol.isEmpty())
return false;
for (auto codeUnit : protocol.codeUnits()) {
if (!isValidProtocolCharacter(codeUnit))
return false;
}
return true;
}
static String encodeProtocolString(const String& protocol)
{
StringBuilder builder;
for (size_t i = 0; i < protocol.length(); i++) {
if (protocol[i] < 0x20 || protocol[i] > 0x7E) {
builder.appendLiteral("\\u");
builder.append(hex(protocol[i], 4));
} else if (protocol[i] == 0x5c)
builder.appendLiteral("\\\\");
else
builder.append(protocol[i]);
}
return builder.toString();
}
static String joinStrings(const Vector<String>& strings, const char* separator)
{
StringBuilder builder;
for (size_t i = 0; i < strings.size(); ++i) {
if (i)
builder.append(separator);
builder.append(strings[i]);
}
return builder.toString();
}
static unsigned saturateAdd(unsigned a, unsigned b)
{
if (std::numeric_limits<unsigned>::max() - a < b)
return std::numeric_limits<unsigned>::max();
return a + b;
}
const char* WebSocket::subprotocolSeparator()
{
return ", ";
}
WebSocket::WebSocket(ScriptExecutionContext& context)
: ActiveDOMObject(&context)
, m_subprotocol(emptyString())
, m_extensions(emptyString())
, m_resumeTimer(*this, &WebSocket::resumeTimerFired)
{
LockHolder lock(allActiveWebSocketsMutex());
allActiveWebSockets(lock).add(this);
}
WebSocket::~WebSocket()
{
{
LockHolder lock(allActiveWebSocketsMutex());
allActiveWebSockets(lock).remove(this);
}
if (m_channel)
m_channel->disconnect();
}
ExceptionOr<Ref<WebSocket>> WebSocket::create(ScriptExecutionContext& context, const String& url)
{
return create(context, url, Vector<String> { });
}
ExceptionOr<Ref<WebSocket>> WebSocket::create(ScriptExecutionContext& context, const String& url, const Vector<String>& protocols)
{
if (url.isNull())
return Exception { SyntaxError };
auto socket = adoptRef(*new WebSocket(context));
socket->suspendIfNeeded();
auto result = socket->connect(context.completeURL(url).string(), protocols);
if (result.hasException())
return result.releaseException();
return socket;
}
ExceptionOr<Ref<WebSocket>> WebSocket::create(ScriptExecutionContext& context, const String& url, const String& protocol)
{
return create(context, url, Vector<String> { 1, protocol });
}
HashSet<WebSocket*>& WebSocket::allActiveWebSockets(const LockHolder&)
{
static NeverDestroyed<HashSet<WebSocket*>> activeWebSockets;
return activeWebSockets;
}
Lock& WebSocket::allActiveWebSocketsMutex()
{
static Lock mutex;
return mutex;
}
ExceptionOr<void> WebSocket::connect(const String& url)
{
return connect(url, Vector<String> { });
}
ExceptionOr<void> WebSocket::connect(const String& url, const String& protocol)
{
return connect(url, Vector<String> { 1, protocol });
}
void WebSocket::failAsynchronously()
{
m_pendingActivity = makePendingActivity(*this);
// We must block this connection. Instead of throwing an exception, we indicate this
// using the error event. But since this code executes as part of the WebSocket's
// constructor, we have to wait until the constructor has completed before firing the
// event; otherwise, users can't connect to the event.
scriptExecutionContext()->postTask([this, protectedThis = makeRef(*this)](auto&) {
this->dispatchOrQueueErrorEvent();
this->stop();
});
}
ExceptionOr<void> WebSocket::connect(const String& url, const Vector<String>& protocols)
{
LOG(Network, "WebSocket %p connect() url='%s'", this, url.utf8().data());
m_url = URL(URL(), url);
ASSERT(scriptExecutionContext());
auto& context = *scriptExecutionContext();
if (!m_url.isValid()) {
context.addConsoleMessage(MessageSource::JS, MessageLevel::Error, "Invalid url for WebSocket " + m_url.stringCenterEllipsizedToLength());
m_state = CLOSED;
return Exception { SyntaxError };
}
if (!m_url.protocolIs("ws") && !m_url.protocolIs("wss")) {
context.addConsoleMessage(MessageSource::JS, MessageLevel::Error, "Wrong url scheme for WebSocket " + m_url.stringCenterEllipsizedToLength());
m_state = CLOSED;
return Exception { SyntaxError };
}
if (m_url.hasFragmentIdentifier()) {
context.addConsoleMessage(MessageSource::JS, MessageLevel::Error, "URL has fragment component " + m_url.stringCenterEllipsizedToLength());
m_state = CLOSED;
return Exception { SyntaxError };
}
ASSERT(context.contentSecurityPolicy());
auto& contentSecurityPolicy = *context.contentSecurityPolicy();
contentSecurityPolicy.upgradeInsecureRequestIfNeeded(m_url, ContentSecurityPolicy::InsecureRequestType::Load);
if (!portAllowed(m_url)) {
String message;
if (m_url.port())
message = makeString("WebSocket port ", m_url.port().value(), " blocked");
else
message = "WebSocket without port blocked"_s;
context.addConsoleMessage(MessageSource::JS, MessageLevel::Error, message);
m_state = CLOSED;
return Exception { SecurityError };
}
// FIXME: Convert this to check the isolated world's Content Security Policy once webkit.org/b/104520 is solved.
if (!context.shouldBypassMainWorldContentSecurityPolicy() && !contentSecurityPolicy.allowConnectToSource(m_url)) {
m_state = CLOSED;
// FIXME: Should this be throwing an exception?
return Exception { SecurityError };
}
if (auto* provider = context.socketProvider())
m_channel = ThreadableWebSocketChannel::create(*scriptExecutionContext(), *this, *provider);
// Every ScriptExecutionContext should have a SocketProvider.
RELEASE_ASSERT(m_channel);
// FIXME: There is a disagreement about restriction of subprotocols between WebSocket API and hybi-10 protocol
// draft. The former simply says "only characters in the range U+0021 to U+007E are allowed," while the latter
// imposes a stricter rule: "the elements MUST be non-empty strings with characters as defined in [RFC2616],
// and MUST all be unique strings."
//
// Here, we throw SyntaxError if the given protocols do not meet the latter criteria. This behavior does not
// comply with WebSocket API specification, but it seems to be the only reasonable way to handle this conflict.
for (auto& protocol : protocols) {
if (!isValidProtocolString(protocol)) {
context.addConsoleMessage(MessageSource::JS, MessageLevel::Error, "Wrong protocol for WebSocket '" + encodeProtocolString(protocol) + "'");
m_state = CLOSED;
return Exception { SyntaxError };
}
}
HashSet<String> visited;
for (auto& protocol : protocols) {
if (!visited.add(protocol).isNewEntry) {
context.addConsoleMessage(MessageSource::JS, MessageLevel::Error, "WebSocket protocols contain duplicates: '" + encodeProtocolString(protocol) + "'");
m_state = CLOSED;
return Exception { SyntaxError };
}
}
RunLoop::main().dispatch([targetURL = m_url.isolatedCopy(), mainFrameURL = context.url().isolatedCopy()]() {
ResourceLoadObserver::shared().logWebSocketLoading(targetURL, mainFrameURL);
});
if (is<Document>(context)) {
Document& document = downcast<Document>(context);
RefPtr<Frame> frame = document.frame();
// FIXME: make the mixed content check equivalent to the non-document mixed content check currently in WorkerThreadableWebSocketChannel::Bridge::connect()
if (!frame || !frame->loader().mixedContentChecker().canRunInsecureContent(document.securityOrigin(), m_url)) {
failAsynchronously();
return { };
}
}
String protocolString;
if (!protocols.isEmpty())
protocolString = joinStrings(protocols, subprotocolSeparator());
if (m_channel->connect(m_url, protocolString) == ThreadableWebSocketChannel::ConnectStatus::KO) {
failAsynchronously();
return { };
}
#if ENABLE(RESOURCE_LOAD_STATISTICS)
auto reportRegistrableDomain = [domain = RegistrableDomain(m_url).isolatedCopy()](auto& context) mutable {
if (auto* frame = downcast<Document>(context).frame())
frame->loader().client().didLoadFromRegistrableDomain(WTFMove(domain));
};
if (is<Document>(context))
reportRegistrableDomain(context);
else
downcast<WorkerGlobalScope>(context).thread().workerLoaderProxy().postTaskToLoader(WTFMove(reportRegistrableDomain));
#endif
m_pendingActivity = makePendingActivity(*this);
return { };
}
ExceptionOr<void> WebSocket::send(const String& message)
{
LOG(Network, "WebSocket %p send() Sending String '%s'", this, message.utf8().data());
if (m_state == CONNECTING)
return Exception { InvalidStateError };
// No exception is raised if the connection was once established but has subsequently been closed.
if (m_state == CLOSING || m_state == CLOSED) {
size_t payloadSize = message.utf8().length();
m_bufferedAmountAfterClose = saturateAdd(m_bufferedAmountAfterClose, payloadSize);
m_bufferedAmountAfterClose = saturateAdd(m_bufferedAmountAfterClose, getFramingOverhead(payloadSize));
return { };
}
ASSERT(m_channel);
m_channel->send(message);
return { };
}
ExceptionOr<void> WebSocket::send(ArrayBuffer& binaryData)
{
LOG(Network, "WebSocket %p send() Sending ArrayBuffer %p", this, &binaryData);
if (m_state == CONNECTING)
return Exception { InvalidStateError };
if (m_state == CLOSING || m_state == CLOSED) {
unsigned payloadSize = binaryData.byteLength();
m_bufferedAmountAfterClose = saturateAdd(m_bufferedAmountAfterClose, payloadSize);
m_bufferedAmountAfterClose = saturateAdd(m_bufferedAmountAfterClose, getFramingOverhead(payloadSize));
return { };
}
ASSERT(m_channel);
m_channel->send(binaryData, 0, binaryData.byteLength());
return { };
}
ExceptionOr<void> WebSocket::send(ArrayBufferView& arrayBufferView)
{
LOG(Network, "WebSocket %p send() Sending ArrayBufferView %p", this, &arrayBufferView);
if (m_state == CONNECTING)
return Exception { InvalidStateError };
if (m_state == CLOSING || m_state == CLOSED) {
unsigned payloadSize = arrayBufferView.byteLength();
m_bufferedAmountAfterClose = saturateAdd(m_bufferedAmountAfterClose, payloadSize);
m_bufferedAmountAfterClose = saturateAdd(m_bufferedAmountAfterClose, getFramingOverhead(payloadSize));
return { };
}
ASSERT(m_channel);
m_channel->send(*arrayBufferView.unsharedBuffer(), arrayBufferView.byteOffset(), arrayBufferView.byteLength());
return { };
}
ExceptionOr<void> WebSocket::send(Blob& binaryData)
{
LOG(Network, "WebSocket %p send() Sending Blob '%s'", this, binaryData.url().stringCenterEllipsizedToLength().utf8().data());
if (m_state == CONNECTING)
return Exception { InvalidStateError };
if (m_state == CLOSING || m_state == CLOSED) {
unsigned payloadSize = static_cast<unsigned>(binaryData.size());
m_bufferedAmountAfterClose = saturateAdd(m_bufferedAmountAfterClose, payloadSize);
m_bufferedAmountAfterClose = saturateAdd(m_bufferedAmountAfterClose, getFramingOverhead(payloadSize));
return { };
}
ASSERT(m_channel);
m_channel->send(binaryData);
return { };
}
ExceptionOr<void> WebSocket::close(Optional<unsigned short> optionalCode, const String& reason)
{
int code = optionalCode ? optionalCode.value() : static_cast<int>(WebSocketChannel::CloseEventCodeNotSpecified);
if (code == WebSocketChannel::CloseEventCodeNotSpecified)
LOG(Network, "WebSocket %p close() without code and reason", this);
else {
LOG(Network, "WebSocket %p close() code=%d reason='%s'", this, code, reason.utf8().data());
if (!(code == WebSocketChannel::CloseEventCodeNormalClosure || (WebSocketChannel::CloseEventCodeMinimumUserDefined <= code && code <= WebSocketChannel::CloseEventCodeMaximumUserDefined)))
return Exception { InvalidAccessError };
CString utf8 = reason.utf8(StrictConversionReplacingUnpairedSurrogatesWithFFFD);
if (utf8.length() > maxReasonSizeInBytes) {
scriptExecutionContext()->addConsoleMessage(MessageSource::JS, MessageLevel::Error, "WebSocket close message is too long."_s);
return Exception { SyntaxError };
}
}
if (m_state == CLOSING || m_state == CLOSED)
return { };
if (m_state == CONNECTING) {
m_state = CLOSING;
m_channel->fail("WebSocket is closed before the connection is established.");
return { };
}
m_state = CLOSING;
if (m_channel)
m_channel->close(code, reason);
return { };
}
RefPtr<ThreadableWebSocketChannel> WebSocket::channel() const
{
return m_channel;
}
const URL& WebSocket::url() const
{
return m_url;
}
WebSocket::State WebSocket::readyState() const
{
return m_state;
}
unsigned WebSocket::bufferedAmount() const
{
return saturateAdd(m_bufferedAmount, m_bufferedAmountAfterClose);
}
String WebSocket::protocol() const
{
return m_subprotocol;
}
String WebSocket::extensions() const
{
return m_extensions;
}
String WebSocket::binaryType() const
{
switch (m_binaryType) {
case BinaryType::Blob:
return "blob"_s;
case BinaryType::ArrayBuffer:
return "arraybuffer"_s;
}
ASSERT_NOT_REACHED();
return String();
}
ExceptionOr<void> WebSocket::setBinaryType(const String& binaryType)
{
if (binaryType == "blob") {
m_binaryType = BinaryType::Blob;
return { };
}
if (binaryType == "arraybuffer") {
m_binaryType = BinaryType::ArrayBuffer;
return { };
}
scriptExecutionContext()->addConsoleMessage(MessageSource::JS, MessageLevel::Error, "'" + binaryType + "' is not a valid value for binaryType; binaryType remains unchanged.");
return Exception { SyntaxError };
}
EventTargetInterface WebSocket::eventTargetInterface() const
{
return WebSocketEventTargetInterfaceType;
}
ScriptExecutionContext* WebSocket::scriptExecutionContext() const
{
return ActiveDOMObject::scriptExecutionContext();
}
void WebSocket::contextDestroyed()
{
LOG(Network, "WebSocket %p contextDestroyed()", this);
ASSERT(!m_channel);
ASSERT(m_state == CLOSED);
ActiveDOMObject::contextDestroyed();
}
void WebSocket::suspend(ReasonForSuspension reason)
{
if (m_resumeTimer.isActive())
m_resumeTimer.stop();
m_shouldDelayEventFiring = true;
if (m_channel) {
if (reason == ReasonForSuspension::BackForwardCache) {
// This will cause didClose() to be called.
m_channel->fail("WebSocket is closed due to suspension.");
} else
m_channel->suspend();
}
}
void WebSocket::resume()
{
if (m_channel)
m_channel->resume();
else if (!m_pendingEvents.isEmpty() && !m_resumeTimer.isActive()) {
// Fire the pending events in a timer as we are not allowed to execute arbitrary JS from resume().
m_resumeTimer.startOneShot(0_s);
}
m_shouldDelayEventFiring = false;
}
void WebSocket::resumeTimerFired()
{
Ref<WebSocket> protectedThis(*this);
ASSERT(!m_pendingEvents.isEmpty());
// Check m_shouldDelayEventFiring when iterating in case firing an event causes
// suspend() to be called.
while (!m_pendingEvents.isEmpty() && !m_shouldDelayEventFiring)
dispatchEvent(m_pendingEvents.takeFirst());
}
void WebSocket::stop()
{
if (m_channel)
m_channel->disconnect();
m_channel = nullptr;
m_state = CLOSED;
m_pendingEvents.clear();
ActiveDOMObject::stop();
m_pendingActivity = nullptr;
}
const char* WebSocket::activeDOMObjectName() const
{
return "WebSocket";
}
void WebSocket::didConnect()
{
LOG(Network, "WebSocket %p didConnect()", this);
if (m_state != CONNECTING) {
didClose(0, ClosingHandshakeIncomplete, WebSocketChannel::CloseEventCodeAbnormalClosure, emptyString());
return;
}
ASSERT(scriptExecutionContext());
m_state = OPEN;
m_subprotocol = m_channel->subprotocol();
m_extensions = m_channel->extensions();
dispatchEvent(Event::create(eventNames().openEvent, Event::CanBubble::No, Event::IsCancelable::No));
}
void WebSocket::didReceiveMessage(const String& msg)
{
LOG(Network, "WebSocket %p didReceiveMessage() Text message '%s'", this, msg.utf8().data());
if (m_state != OPEN)
return;
ASSERT(scriptExecutionContext());
dispatchEvent(MessageEvent::create(msg, SecurityOrigin::create(m_url)->toString()));
}
void WebSocket::didReceiveBinaryData(Vector<uint8_t>&& binaryData)
{
LOG(Network, "WebSocket %p didReceiveBinaryData() %u byte binary message", this, static_cast<unsigned>(binaryData.size()));
switch (m_binaryType) {
case BinaryType::Blob:
// FIXME: We just received the data from NetworkProcess, and are sending it back. This is inefficient.
dispatchEvent(MessageEvent::create(Blob::create(WTFMove(binaryData), emptyString()), SecurityOrigin::create(m_url)->toString()));
break;
case BinaryType::ArrayBuffer:
dispatchEvent(MessageEvent::create(ArrayBuffer::create(binaryData.data(), binaryData.size()), SecurityOrigin::create(m_url)->toString()));
break;
}
}
void WebSocket::didReceiveMessageError()
{
LOG(Network, "WebSocket %p didReceiveErrorMessage()", this);
m_state = CLOSED;
ASSERT(scriptExecutionContext());
dispatchOrQueueErrorEvent();
}
void WebSocket::didUpdateBufferedAmount(unsigned bufferedAmount)
{
LOG(Network, "WebSocket %p didUpdateBufferedAmount() New bufferedAmount is %u", this, bufferedAmount);
if (m_state == CLOSED)
return;
m_bufferedAmount = bufferedAmount;
}
void WebSocket::didStartClosingHandshake()
{
LOG(Network, "WebSocket %p didStartClosingHandshake()", this);
m_state = CLOSING;
}
void WebSocket::didClose(unsigned unhandledBufferedAmount, ClosingHandshakeCompletionStatus closingHandshakeCompletion, unsigned short code, const String& reason)
{
LOG(Network, "WebSocket %p didClose()", this);
if (!m_channel)
return;
bool wasClean = m_state == CLOSING && !unhandledBufferedAmount && closingHandshakeCompletion == ClosingHandshakeComplete && code != WebSocketChannel::CloseEventCodeAbnormalClosure;
m_state = CLOSED;
m_bufferedAmount = unhandledBufferedAmount;
ASSERT(scriptExecutionContext());
dispatchOrQueueEvent(CloseEvent::create(wasClean, code, reason));
if (m_channel) {
m_channel->disconnect();
m_channel = nullptr;
}
m_pendingActivity = nullptr;
}
void WebSocket::didUpgradeURL()
{
ASSERT(m_url.protocolIs("ws"));
m_url.setProtocol("wss");
}
size_t WebSocket::getFramingOverhead(size_t payloadSize)
{
static const size_t hybiBaseFramingOverhead = 2; // Every frame has at least two-byte header.
static const size_t hybiMaskingKeyLength = 4; // Every frame from client must have masking key.
static const size_t minimumPayloadSizeWithTwoByteExtendedPayloadLength = 126;
static const size_t minimumPayloadSizeWithEightByteExtendedPayloadLength = 0x10000;
size_t overhead = hybiBaseFramingOverhead + hybiMaskingKeyLength;
if (payloadSize >= minimumPayloadSizeWithEightByteExtendedPayloadLength)
overhead += 8;
else if (payloadSize >= minimumPayloadSizeWithTwoByteExtendedPayloadLength)
overhead += 2;
return overhead;
}
void WebSocket::dispatchOrQueueErrorEvent()
{
if (m_dispatchedErrorEvent)
return;
m_dispatchedErrorEvent = true;
dispatchOrQueueEvent(Event::create(eventNames().errorEvent, Event::CanBubble::No, Event::IsCancelable::No));
}
void WebSocket::dispatchOrQueueEvent(Ref<Event>&& event)
{
if (m_shouldDelayEventFiring)
m_pendingEvents.append(WTFMove(event));
else
dispatchEvent(event);
}
} // namespace WebCore