Source/WebCore/loader/DocumentThreadableLoader.cpp - platform/external/chromium_org/third_party/WebKit - Git at Google

 /*
  * Copyright (C) 2011, 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"
 #include "DocumentThreadableLoader.h"

 #include "CachedRawResource.h"
 #include "CachedResourceLoader.h"
 #include "CachedResourceRequest.h"
 #include "CrossOriginAccessControl.h"
 #include "CrossOriginPreflightResultCache.h"
 #include "Document.h"
 #include "DocumentThreadableLoaderClient.h"
 #include "Frame.h"
 #include "FrameLoader.h"
 #include "InspectorInstrumentation.h"
 #include "ResourceError.h"
 #include "ResourceRequest.h"
 #include "SchemeRegistry.h"
 #include "SecurityOrigin.h"
 #include "SubresourceLoader.h"
 #include "ThreadableLoaderClient.h"
 #include <wtf/Assertions.h>
 #include <wtf/UnusedParam.h>

 #if ENABLE(INSPECTOR)
 #include "ProgressTracker.h"
 #endif

 namespace WebCore {

 void DocumentThreadableLoader::loadResourceSynchronously(Document* document, const ResourceRequest& request, ThreadableLoaderClient& client, const ThreadableLoaderOptions& options)
 {
     // The loader will be deleted as soon as this function exits.
     RefPtr<DocumentThreadableLoader> loader = adoptRef(new DocumentThreadableLoader(document, &client, LoadSynchronously, request, options));
     ASSERT(loader->hasOneRef());
 }

 PassRefPtr<DocumentThreadableLoader> DocumentThreadableLoader::create(Document* document, ThreadableLoaderClient* client, const ResourceRequest& request, const ThreadableLoaderOptions& options)
 {
     RefPtr<DocumentThreadableLoader> loader = adoptRef(new DocumentThreadableLoader(document, client, LoadAsynchronously, request, options));
     if (!loader->m_resource)
         loader = 0;
     return loader.release();
 }

 DocumentThreadableLoader::DocumentThreadableLoader(Document* document, ThreadableLoaderClient* client, BlockingBehavior blockingBehavior, const ResourceRequest& request, const ThreadableLoaderOptions& options)
     : m_client(client)
     , m_document(document)
     , m_options(options)
     , m_sameOriginRequest(securityOrigin()->canRequest(request.url()))
     , m_simpleRequest(true)
     , m_async(blockingBehavior == LoadAsynchronously)
 #if ENABLE(INSPECTOR)
     , m_preflightRequestIdentifier(0)
 #endif
 {
     ASSERT(document);
     ASSERT(client);
     // Setting an outgoing referer is only supported in the async code path.
     ASSERT(m_async || request.httpReferrer().isEmpty());

     if (m_sameOriginRequest || m_options.crossOriginRequestPolicy == AllowCrossOriginRequests) {
         loadRequest(request, DoSecurityCheck);
         return;
     }

     if (m_options.crossOriginRequestPolicy == DenyCrossOriginRequests) {
         m_client->didFail(ResourceError(errorDomainWebKitInternal, 0, request.url().string(), "Cross origin requests are not supported."));
         return;
     }

     makeCrossOriginAccessRequest(request);
 }

 void DocumentThreadableLoader::makeCrossOriginAccessRequest(const ResourceRequest& request)
 {
     ASSERT(m_options.crossOriginRequestPolicy == UseAccessControl);

     OwnPtr<ResourceRequest> crossOriginRequest = adoptPtr(new ResourceRequest(request));
     updateRequestForAccessControl(*crossOriginRequest, securityOrigin(), m_options.allowCredentials);

     if ((m_options.preflightPolicy == ConsiderPreflight && isSimpleCrossOriginAccessRequest(crossOriginRequest->httpMethod(), crossOriginRequest->httpHeaderFields())) || m_options.preflightPolicy == PreventPreflight)
         makeSimpleCrossOriginAccessRequest(*crossOriginRequest);
     else {
         m_simpleRequest = false;
         m_actualRequest = crossOriginRequest.release();

         if (CrossOriginPreflightResultCache::shared().canSkipPreflight(securityOrigin()->toString(), m_actualRequest->url(), m_options.allowCredentials, m_actualRequest->httpMethod(), m_actualRequest->httpHeaderFields()))
             preflightSuccess();
         else
             makeCrossOriginAccessRequestWithPreflight(*m_actualRequest);
     }
 }

 void DocumentThreadableLoader::makeSimpleCrossOriginAccessRequest(const ResourceRequest& request)
 {
     ASSERT(m_options.preflightPolicy != ForcePreflight);
     ASSERT(m_options.preflightPolicy == PreventPreflight || isSimpleCrossOriginAccessRequest(request.httpMethod(), request.httpHeaderFields()));

     // Cross-origin requests are only allowed for HTTP and registered schemes. We would catch this when checking response headers later, but there is no reason to send a request that's guaranteed to be denied.
     if (!SchemeRegistry::shouldTreatURLSchemeAsCORSEnabled(request.url().protocol())) {
         m_client->didFail(ResourceError(errorDomainWebKitInternal, 0, request.url().string(), "Cross origin requests are only supported for HTTP."));
         return;
     }

     loadRequest(request, DoSecurityCheck);
 }

 void DocumentThreadableLoader::makeCrossOriginAccessRequestWithPreflight(const ResourceRequest& request)
 {
     ResourceRequest preflightRequest = createAccessControlPreflightRequest(request, securityOrigin());
     loadRequest(preflightRequest, DoSecurityCheck);
 }

 DocumentThreadableLoader::~DocumentThreadableLoader()
 {
     if (m_resource)
         m_resource->removeClient(this);
 }

 void DocumentThreadableLoader::cancel()
 {
     RefPtr<DocumentThreadableLoader> protect(this);

     // Cancel can re-enter and m_resource might be null here as a result.
     if (m_client && m_resource) {
         ResourceError error(errorDomainWebKitInternal, 0, m_resource->url(), "Load cancelled");
         error.setIsCancellation(true);
         didFail(error);
     }
     clearResource();
     m_client = 0;
 }

 void DocumentThreadableLoader::setDefersLoading(bool value)
 {
     if (m_resource)
         m_resource->setDefersLoading(value);
 }

 void DocumentThreadableLoader::clearResource()
 {
     // Script can cancel and restart a request reentrantly within removeClient(),
     // which could lead to calling CachedResource::removeClient() multiple times for
     // this DocumentThreadableLoader. Save off a copy of m_resource and clear it to
     // prevent the reentrancy.
     if (CachedResourceHandle<CachedRawResource> resource = m_resource) {
         m_resource = 0;
         resource->removeClient(this);
     }
 }

 void DocumentThreadableLoader::redirectReceived(CachedResource* resource, ResourceRequest& request, const ResourceResponse& redirectResponse)
 {
     ASSERT(m_client);
     ASSERT_UNUSED(resource, resource == m_resource);

     RefPtr<DocumentThreadableLoader> protect(this);
     // Allow same origin requests to continue after allowing clients to audit the redirect.
     if (isAllowedRedirect(request.url())) {
         if (m_client->isDocumentThreadableLoaderClient())
             static_cast<DocumentThreadableLoaderClient*>(m_client)->willSendRequest(request, redirectResponse);
         return;
     }

     // When using access control, only simple cross origin requests are allowed to redirect. The new request URL must have a supported
     // scheme and not contain the userinfo production. In addition, the redirect response must pass the access control check.
     if (m_options.crossOriginRequestPolicy == UseAccessControl) {
         bool allowRedirect = false;
         if (m_simpleRequest) {
             String accessControlErrorDescription;
             allowRedirect = SchemeRegistry::shouldTreatURLSchemeAsCORSEnabled(request.url().protocol())
                             && request.url().user().isEmpty()
                             && request.url().pass().isEmpty()
                             && passesAccessControlCheck(redirectResponse, m_options.allowCredentials, securityOrigin(), accessControlErrorDescription);
         }

         if (allowRedirect) {
             if (m_resource)
                 clearResource();

             RefPtr<SecurityOrigin> originalOrigin = SecurityOrigin::createFromString(redirectResponse.url());
             RefPtr<SecurityOrigin> requestOrigin = SecurityOrigin::createFromString(request.url());
             // If the request URL origin is not same origin with the original URL origin, set source origin to a globally unique identifier.
             if (!originalOrigin->isSameSchemeHostPort(requestOrigin.get()))
                 m_options.securityOrigin = SecurityOrigin::createUnique();
             // Force any subsequent requests to use these checks.
             m_sameOriginRequest = false;

             // Remove any headers that may have been added by the network layer that cause access control to fail.
             request.clearHTTPContentType();
             request.clearHTTPReferrer();
             request.clearHTTPOrigin();
             request.clearHTTPUserAgent();
             request.clearHTTPAccept();
             makeCrossOriginAccessRequest(request);
             return;
         }
     }

     m_client->didFailRedirectCheck();
     request = ResourceRequest();
 }

 void DocumentThreadableLoader::dataSent(CachedResource* resource, unsigned long long bytesSent, unsigned long long totalBytesToBeSent)
 {
     ASSERT(m_client);
     ASSERT_UNUSED(resource, resource == m_resource);
     m_client->didSendData(bytesSent, totalBytesToBeSent);
 }

 void DocumentThreadableLoader::responseReceived(CachedResource* resource, const ResourceResponse& response)
 {
     ASSERT_UNUSED(resource, resource == m_resource);
     didReceiveResponse(m_resource->identifier(), response);
 }

 void DocumentThreadableLoader::didReceiveResponse(unsigned long identifier, const ResourceResponse& response)
 {
     ASSERT(m_client);

 #if ENABLE(INSPECTOR)
     if (m_preflightRequestIdentifier) {
         DocumentLoader* loader = m_document->frame()->loader()->documentLoader();
         InspectorInstrumentationCookie cookie = InspectorInstrumentation::willReceiveResourceResponse(m_document->frame(), m_preflightRequestIdentifier, response);
         InspectorInstrumentation::didReceiveResourceResponse(cookie, m_preflightRequestIdentifier, loader, response, 0);
     }
 #endif

     String accessControlErrorDescription;
     if (m_actualRequest) {
         if (!passesAccessControlCheck(response, m_options.allowCredentials, securityOrigin(), accessControlErrorDescription)) {
             preflightFailure(response.url(), accessControlErrorDescription);
             return;
         }

         OwnPtr<CrossOriginPreflightResultCacheItem> preflightResult = adoptPtr(new CrossOriginPreflightResultCacheItem(m_options.allowCredentials));
         if (!preflightResult->parse(response, accessControlErrorDescription)
             || !preflightResult->allowsCrossOriginMethod(m_actualRequest->httpMethod(), accessControlErrorDescription)
             || !preflightResult->allowsCrossOriginHeaders(m_actualRequest->httpHeaderFields(), accessControlErrorDescription)) {
             preflightFailure(response.url(), accessControlErrorDescription);
             return;
         }

         CrossOriginPreflightResultCache::shared().appendEntry(securityOrigin()->toString(), m_actualRequest->url(), preflightResult.release());
     } else {
         if (!m_sameOriginRequest && m_options.crossOriginRequestPolicy == UseAccessControl) {
             if (!passesAccessControlCheck(response, m_options.allowCredentials, securityOrigin(), accessControlErrorDescription)) {
                 m_client->didFail(ResourceError(errorDomainWebKitInternal, 0, response.url().string(), accessControlErrorDescription));
                 return;
             }
         }

         m_client->didReceiveResponse(identifier, response);
     }
 }

 void DocumentThreadableLoader::dataReceived(CachedResource* resource, const char* data, int dataLength)
 {
     ASSERT(m_client);
     ASSERT_UNUSED(resource, resource == m_resource);

 #if ENABLE(INSPECTOR)
     if (m_preflightRequestIdentifier)
         InspectorInstrumentation::didReceiveData(m_document->frame(), m_preflightRequestIdentifier, 0, 0, dataLength);
 #endif

     // Preflight data should be invisible to clients.
     if (m_actualRequest)
         return;

     m_client->didReceiveData(data, dataLength);
 }

 void DocumentThreadableLoader::notifyFinished(CachedResource* resource)
 {
     ASSERT(m_client);
     ASSERT_UNUSED(resource, resource == m_resource);

     if (m_resource && m_resource->errorOccurred())
         didFail(m_resource->resourceError());
     else
         didFinishLoading(m_resource->identifier(), m_resource->loadFinishTime());
 }

 void DocumentThreadableLoader::didFinishLoading(unsigned long identifier, double finishTime)
 {
 #if ENABLE(INSPECTOR)
     if (m_preflightRequestIdentifier)
         InspectorInstrumentation::didFinishLoading(m_document->frame(), m_document->frame()->loader()->documentLoader(), m_preflightRequestIdentifier, finishTime);
 #endif

     if (m_actualRequest) {
         ASSERT(!m_sameOriginRequest);
         ASSERT(m_options.crossOriginRequestPolicy == UseAccessControl);
         preflightSuccess();
     } else
         m_client->didFinishLoading(identifier, finishTime);
 }

 void DocumentThreadableLoader::didFail(const ResourceError& error)
 {
 #if ENABLE(INSPECTOR)
     if (m_preflightRequestIdentifier)
         InspectorInstrumentation::didFailLoading(m_document->frame(), m_document->frame()->loader()->documentLoader(), m_preflightRequestIdentifier, error);
 #endif

     m_client->didFail(error);
 }

 void DocumentThreadableLoader::preflightSuccess()
 {
     OwnPtr<ResourceRequest> actualRequest;
     actualRequest.swap(m_actualRequest);

     actualRequest->setHTTPOrigin(securityOrigin()->toString());

     clearResource();

     // It should be ok to skip the security check since we already asked about the preflight request.
     loadRequest(*actualRequest, SkipSecurityCheck);
 }

 void DocumentThreadableLoader::preflightFailure(const String& url, const String& errorDescription)
 {
     m_actualRequest = nullptr; // Prevent didFinishLoading() from bypassing access check.
     m_client->didFail(ResourceError(errorDomainWebKitInternal, 0, url, errorDescription));
 }

 void DocumentThreadableLoader::loadRequest(const ResourceRequest& request, SecurityCheckPolicy securityCheck)
 {
     // Any credential should have been removed from the cross-site requests.
     const KURL& requestURL = request.url();
     m_options.securityCheck = securityCheck;
     ASSERT(m_sameOriginRequest || requestURL.user().isEmpty());
     ASSERT(m_sameOriginRequest || requestURL.pass().isEmpty());

     if (m_async) {
         ThreadableLoaderOptions options = m_options;
         options.crossOriginCredentialPolicy = DoNotAskClientForCrossOriginCredentials;
         if (m_actualRequest) {
             // Don't sniff content or send load callbacks for the preflight request.
             options.sendLoadCallbacks = DoNotSendCallbacks;
             options.sniffContent = DoNotSniffContent;
             // Keep buffering the data for the preflight request.
             options.shouldBufferData = BufferData;
         }

         CachedResourceRequest newRequest(request, options);
 #if ENABLE(INSPECTOR)
         if (m_actualRequest) {
             // Because willSendRequest only gets called during redirects, we initialize the identifier and the first willSendRequest here.
             m_preflightRequestIdentifier = m_document->frame()->page()->progress()->createUniqueIdentifier();
             ResourceResponse redirectResponse = ResourceResponse();
             InspectorInstrumentation::willSendRequest(m_document->frame(), m_preflightRequestIdentifier, m_document->frame()->loader()->documentLoader(), newRequest.mutableResourceRequest(), redirectResponse);
         }
 #endif
         ASSERT(!m_resource);
         m_resource = m_document->cachedResourceLoader()->requestRawResource(newRequest);
         if (m_resource) {
 #if ENABLE(INSPECTOR)
             if (m_resource->loader()) {
                 unsigned long identifier = m_actualRequest ? m_preflightRequestIdentifier : m_resource->loader()->identifier();
                 InspectorInstrumentation::documentThreadableLoaderStartedLoadingForClient(m_document, identifier, m_client);
             }
 #endif
             m_resource->addClient(this);
         }
         return;
     }

     // FIXME: ThreadableLoaderOptions.sniffContent is not supported for synchronous requests.
     Vector<char> data;
     ResourceError error;
     ResourceResponse response;
     unsigned long identifier = std::numeric_limits<unsigned long>::max();
     if (m_document->frame())
         identifier = m_document->frame()->loader()->loadResourceSynchronously(request, m_options.allowCredentials, error, response, data);

     InspectorInstrumentation::documentThreadableLoaderStartedLoadingForClient(m_document, identifier, m_client);

     // No exception for file:/// resources, see <rdar://problem/4962298>.
     // Also, if we have an HTTP response, then it wasn't a network error in fact.
     if (!error.isNull() && !requestURL.isLocalFile() && response.httpStatusCode() <= 0) {
         m_client->didFail(error);
         return;
     }

     // FIXME: FrameLoader::loadSynchronously() does not tell us whether a redirect happened or not, so we guess by comparing the
     // request and response URLs. This isn't a perfect test though, since a server can serve a redirect to the same URL that was
     // requested. Also comparing the request and response URLs as strings will fail if the requestURL still has its credentials.
     if (requestURL != response.url() && !isAllowedRedirect(response.url())) {
         m_client->didFailRedirectCheck();
         return;
     }

     didReceiveResponse(identifier, response);

     const char* bytes = static_cast<const char*>(data.data());
     int len = static_cast<int>(data.size());
     dataReceived(0, bytes, len);

     didFinishLoading(identifier, 0.0);
 }

 bool DocumentThreadableLoader::isAllowedRedirect(const KURL& url)
 {
     if (m_options.crossOriginRequestPolicy == AllowCrossOriginRequests)
         return true;

     return m_sameOriginRequest && securityOrigin()->canRequest(url);
 }

 SecurityOrigin* DocumentThreadableLoader::securityOrigin() const
 {
     return m_options.securityOrigin ? m_options.securityOrigin.get() : m_document->securityOrigin();
 }

 } // namespace WebCore
	/*
	* Copyright (C) 2011, 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"
	#include "DocumentThreadableLoader.h"

	#include "CachedRawResource.h"
	#include "CachedResourceLoader.h"
	#include "CachedResourceRequest.h"
	#include "CrossOriginAccessControl.h"
	#include "CrossOriginPreflightResultCache.h"
	#include "Document.h"
	#include "DocumentThreadableLoaderClient.h"
	#include "Frame.h"
	#include "FrameLoader.h"
	#include "InspectorInstrumentation.h"
	#include "ResourceError.h"
	#include "ResourceRequest.h"
	#include "SchemeRegistry.h"
	#include "SecurityOrigin.h"
	#include "SubresourceLoader.h"
	#include "ThreadableLoaderClient.h"
	#include <wtf/Assertions.h>
	#include <wtf/UnusedParam.h>

	#if ENABLE(INSPECTOR)
	#include "ProgressTracker.h"
	#endif

	namespace WebCore {

	void DocumentThreadableLoader::loadResourceSynchronously(Document* document, const ResourceRequest& request, ThreadableLoaderClient& client, const ThreadableLoaderOptions& options)
	{
	// The loader will be deleted as soon as this function exits.
	RefPtr<DocumentThreadableLoader> loader = adoptRef(new DocumentThreadableLoader(document, &client, LoadSynchronously, request, options));
	ASSERT(loader->hasOneRef());
	}

	PassRefPtr<DocumentThreadableLoader> DocumentThreadableLoader::create(Document* document, ThreadableLoaderClient* client, const ResourceRequest& request, const ThreadableLoaderOptions& options)
	{
	RefPtr<DocumentThreadableLoader> loader = adoptRef(new DocumentThreadableLoader(document, client, LoadAsynchronously, request, options));
	if (!loader->m_resource)
	loader = 0;
	return loader.release();
	}

	DocumentThreadableLoader::DocumentThreadableLoader(Document* document, ThreadableLoaderClient* client, BlockingBehavior blockingBehavior, const ResourceRequest& request, const ThreadableLoaderOptions& options)
	: m_client(client)
	, m_document(document)
	, m_options(options)
	, m_sameOriginRequest(securityOrigin()->canRequest(request.url()))
	, m_simpleRequest(true)
	, m_async(blockingBehavior == LoadAsynchronously)
	#if ENABLE(INSPECTOR)
	, m_preflightRequestIdentifier(0)
	#endif
	{
	ASSERT(document);
	ASSERT(client);
	// Setting an outgoing referer is only supported in the async code path.
	ASSERT(m_async \|\| request.httpReferrer().isEmpty());

	if (m_sameOriginRequest \|\| m_options.crossOriginRequestPolicy == AllowCrossOriginRequests) {
	loadRequest(request, DoSecurityCheck);
	return;
	}

	if (m_options.crossOriginRequestPolicy == DenyCrossOriginRequests) {
	m_client->didFail(ResourceError(errorDomainWebKitInternal, 0, request.url().string(), "Cross origin requests are not supported."));
	return;
	}

	makeCrossOriginAccessRequest(request);
	}

	void DocumentThreadableLoader::makeCrossOriginAccessRequest(const ResourceRequest& request)
	{
	ASSERT(m_options.crossOriginRequestPolicy == UseAccessControl);

	OwnPtr<ResourceRequest> crossOriginRequest = adoptPtr(new ResourceRequest(request));
	updateRequestForAccessControl(*crossOriginRequest, securityOrigin(), m_options.allowCredentials);

	if ((m_options.preflightPolicy == ConsiderPreflight && isSimpleCrossOriginAccessRequest(crossOriginRequest->httpMethod(), crossOriginRequest->httpHeaderFields())) \|\| m_options.preflightPolicy == PreventPreflight)
	makeSimpleCrossOriginAccessRequest(*crossOriginRequest);
	else {
	m_simpleRequest = false;
	m_actualRequest = crossOriginRequest.release();

	if (CrossOriginPreflightResultCache::shared().canSkipPreflight(securityOrigin()->toString(), m_actualRequest->url(), m_options.allowCredentials, m_actualRequest->httpMethod(), m_actualRequest->httpHeaderFields()))
	preflightSuccess();
	else
	makeCrossOriginAccessRequestWithPreflight(*m_actualRequest);
	}
	}

	void DocumentThreadableLoader::makeSimpleCrossOriginAccessRequest(const ResourceRequest& request)
	{
	ASSERT(m_options.preflightPolicy != ForcePreflight);
	ASSERT(m_options.preflightPolicy == PreventPreflight \|\| isSimpleCrossOriginAccessRequest(request.httpMethod(), request.httpHeaderFields()));

	// Cross-origin requests are only allowed for HTTP and registered schemes. We would catch this when checking response headers later, but there is no reason to send a request that's guaranteed to be denied.
	if (!SchemeRegistry::shouldTreatURLSchemeAsCORSEnabled(request.url().protocol())) {
	m_client->didFail(ResourceError(errorDomainWebKitInternal, 0, request.url().string(), "Cross origin requests are only supported for HTTP."));
	return;
	}

	loadRequest(request, DoSecurityCheck);
	}

	void DocumentThreadableLoader::makeCrossOriginAccessRequestWithPreflight(const ResourceRequest& request)
	{
	ResourceRequest preflightRequest = createAccessControlPreflightRequest(request, securityOrigin());
	loadRequest(preflightRequest, DoSecurityCheck);
	}

	DocumentThreadableLoader::~DocumentThreadableLoader()
	{
	if (m_resource)
	m_resource->removeClient(this);
	}

	void DocumentThreadableLoader::cancel()
	{
	RefPtr<DocumentThreadableLoader> protect(this);

	// Cancel can re-enter and m_resource might be null here as a result.
	if (m_client && m_resource) {
	ResourceError error(errorDomainWebKitInternal, 0, m_resource->url(), "Load cancelled");
	error.setIsCancellation(true);
	didFail(error);
	}
	clearResource();
	m_client = 0;
	}

	void DocumentThreadableLoader::setDefersLoading(bool value)
	{
	if (m_resource)
	m_resource->setDefersLoading(value);
	}

	void DocumentThreadableLoader::clearResource()
	{
	// Script can cancel and restart a request reentrantly within removeClient(),
	// which could lead to calling CachedResource::removeClient() multiple times for
	// this DocumentThreadableLoader. Save off a copy of m_resource and clear it to
	// prevent the reentrancy.
	if (CachedResourceHandle<CachedRawResource> resource = m_resource) {
	m_resource = 0;
	resource->removeClient(this);
	}
	}

	void DocumentThreadableLoader::redirectReceived(CachedResource* resource, ResourceRequest& request, const ResourceResponse& redirectResponse)
	{
	ASSERT(m_client);
	ASSERT_UNUSED(resource, resource == m_resource);

	RefPtr<DocumentThreadableLoader> protect(this);
	// Allow same origin requests to continue after allowing clients to audit the redirect.
	if (isAllowedRedirect(request.url())) {
	if (m_client->isDocumentThreadableLoaderClient())
	static_cast<DocumentThreadableLoaderClient*>(m_client)->willSendRequest(request, redirectResponse);
	return;
	}

	// When using access control, only simple cross origin requests are allowed to redirect. The new request URL must have a supported
	// scheme and not contain the userinfo production. In addition, the redirect response must pass the access control check.
	if (m_options.crossOriginRequestPolicy == UseAccessControl) {
	bool allowRedirect = false;
	if (m_simpleRequest) {
	String accessControlErrorDescription;
	allowRedirect = SchemeRegistry::shouldTreatURLSchemeAsCORSEnabled(request.url().protocol())
	&& request.url().user().isEmpty()
	&& request.url().pass().isEmpty()
	&& passesAccessControlCheck(redirectResponse, m_options.allowCredentials, securityOrigin(), accessControlErrorDescription);
	}

	if (allowRedirect) {
	if (m_resource)
	clearResource();

	RefPtr<SecurityOrigin> originalOrigin = SecurityOrigin::createFromString(redirectResponse.url());
	RefPtr<SecurityOrigin> requestOrigin = SecurityOrigin::createFromString(request.url());
	// If the request URL origin is not same origin with the original URL origin, set source origin to a globally unique identifier.
	if (!originalOrigin->isSameSchemeHostPort(requestOrigin.get()))
	m_options.securityOrigin = SecurityOrigin::createUnique();
	// Force any subsequent requests to use these checks.
	m_sameOriginRequest = false;

	// Remove any headers that may have been added by the network layer that cause access control to fail.
	request.clearHTTPContentType();
	request.clearHTTPReferrer();
	request.clearHTTPOrigin();
	request.clearHTTPUserAgent();
	request.clearHTTPAccept();
	makeCrossOriginAccessRequest(request);
	return;
	}
	}

	m_client->didFailRedirectCheck();
	request = ResourceRequest();
	}

	void DocumentThreadableLoader::dataSent(CachedResource* resource, unsigned long long bytesSent, unsigned long long totalBytesToBeSent)
	{
	ASSERT(m_client);
	ASSERT_UNUSED(resource, resource == m_resource);
	m_client->didSendData(bytesSent, totalBytesToBeSent);
	}

	void DocumentThreadableLoader::responseReceived(CachedResource* resource, const ResourceResponse& response)
	{
	ASSERT_UNUSED(resource, resource == m_resource);
	didReceiveResponse(m_resource->identifier(), response);
	}

	void DocumentThreadableLoader::didReceiveResponse(unsigned long identifier, const ResourceResponse& response)
	{
	ASSERT(m_client);

	#if ENABLE(INSPECTOR)
	if (m_preflightRequestIdentifier) {
	DocumentLoader* loader = m_document->frame()->loader()->documentLoader();
	InspectorInstrumentationCookie cookie = InspectorInstrumentation::willReceiveResourceResponse(m_document->frame(), m_preflightRequestIdentifier, response);
	InspectorInstrumentation::didReceiveResourceResponse(cookie, m_preflightRequestIdentifier, loader, response, 0);
	}
	#endif

	String accessControlErrorDescription;
	if (m_actualRequest) {
	if (!passesAccessControlCheck(response, m_options.allowCredentials, securityOrigin(), accessControlErrorDescription)) {
	preflightFailure(response.url(), accessControlErrorDescription);
	return;
	}

	OwnPtr<CrossOriginPreflightResultCacheItem> preflightResult = adoptPtr(new CrossOriginPreflightResultCacheItem(m_options.allowCredentials));
	if (!preflightResult->parse(response, accessControlErrorDescription)
	\|\| !preflightResult->allowsCrossOriginMethod(m_actualRequest->httpMethod(), accessControlErrorDescription)
	\|\| !preflightResult->allowsCrossOriginHeaders(m_actualRequest->httpHeaderFields(), accessControlErrorDescription)) {
	preflightFailure(response.url(), accessControlErrorDescription);
	return;
	}

	CrossOriginPreflightResultCache::shared().appendEntry(securityOrigin()->toString(), m_actualRequest->url(), preflightResult.release());
	} else {
	if (!m_sameOriginRequest && m_options.crossOriginRequestPolicy == UseAccessControl) {
	if (!passesAccessControlCheck(response, m_options.allowCredentials, securityOrigin(), accessControlErrorDescription)) {
	m_client->didFail(ResourceError(errorDomainWebKitInternal, 0, response.url().string(), accessControlErrorDescription));
	return;
	}
	}

	m_client->didReceiveResponse(identifier, response);
	}
	}

	void DocumentThreadableLoader::dataReceived(CachedResource* resource, const char* data, int dataLength)
	{
	ASSERT(m_client);
	ASSERT_UNUSED(resource, resource == m_resource);

	#if ENABLE(INSPECTOR)
	if (m_preflightRequestIdentifier)
	InspectorInstrumentation::didReceiveData(m_document->frame(), m_preflightRequestIdentifier, 0, 0, dataLength);
	#endif

	// Preflight data should be invisible to clients.
	if (m_actualRequest)
	return;

	m_client->didReceiveData(data, dataLength);
	}

	void DocumentThreadableLoader::notifyFinished(CachedResource* resource)
	{
	ASSERT(m_client);
	ASSERT_UNUSED(resource, resource == m_resource);

	if (m_resource && m_resource->errorOccurred())
	didFail(m_resource->resourceError());
	else
	didFinishLoading(m_resource->identifier(), m_resource->loadFinishTime());
	}

	void DocumentThreadableLoader::didFinishLoading(unsigned long identifier, double finishTime)
	{
	#if ENABLE(INSPECTOR)
	if (m_preflightRequestIdentifier)
	InspectorInstrumentation::didFinishLoading(m_document->frame(), m_document->frame()->loader()->documentLoader(), m_preflightRequestIdentifier, finishTime);
	#endif

	if (m_actualRequest) {
	ASSERT(!m_sameOriginRequest);
	ASSERT(m_options.crossOriginRequestPolicy == UseAccessControl);
	preflightSuccess();
	} else
	m_client->didFinishLoading(identifier, finishTime);
	}

	void DocumentThreadableLoader::didFail(const ResourceError& error)
	{
	#if ENABLE(INSPECTOR)
	if (m_preflightRequestIdentifier)
	InspectorInstrumentation::didFailLoading(m_document->frame(), m_document->frame()->loader()->documentLoader(), m_preflightRequestIdentifier, error);
	#endif

	m_client->didFail(error);
	}

	void DocumentThreadableLoader::preflightSuccess()
	{
	OwnPtr<ResourceRequest> actualRequest;
	actualRequest.swap(m_actualRequest);

	actualRequest->setHTTPOrigin(securityOrigin()->toString());

	clearResource();

	// It should be ok to skip the security check since we already asked about the preflight request.
	loadRequest(*actualRequest, SkipSecurityCheck);
	}

	void DocumentThreadableLoader::preflightFailure(const String& url, const String& errorDescription)
	{
	m_actualRequest = nullptr; // Prevent didFinishLoading() from bypassing access check.
	m_client->didFail(ResourceError(errorDomainWebKitInternal, 0, url, errorDescription));
	}

	void DocumentThreadableLoader::loadRequest(const ResourceRequest& request, SecurityCheckPolicy securityCheck)
	{
	// Any credential should have been removed from the cross-site requests.
	const KURL& requestURL = request.url();
	m_options.securityCheck = securityCheck;
	ASSERT(m_sameOriginRequest \|\| requestURL.user().isEmpty());
	ASSERT(m_sameOriginRequest \|\| requestURL.pass().isEmpty());

	if (m_async) {
	ThreadableLoaderOptions options = m_options;
	options.crossOriginCredentialPolicy = DoNotAskClientForCrossOriginCredentials;
	if (m_actualRequest) {
	// Don't sniff content or send load callbacks for the preflight request.
	options.sendLoadCallbacks = DoNotSendCallbacks;
	options.sniffContent = DoNotSniffContent;
	// Keep buffering the data for the preflight request.
	options.shouldBufferData = BufferData;
	}

	CachedResourceRequest newRequest(request, options);
	#if ENABLE(INSPECTOR)
	if (m_actualRequest) {
	// Because willSendRequest only gets called during redirects, we initialize the identifier and the first willSendRequest here.
	m_preflightRequestIdentifier = m_document->frame()->page()->progress()->createUniqueIdentifier();
	ResourceResponse redirectResponse = ResourceResponse();
	InspectorInstrumentation::willSendRequest(m_document->frame(), m_preflightRequestIdentifier, m_document->frame()->loader()->documentLoader(), newRequest.mutableResourceRequest(), redirectResponse);
	}
	#endif
	ASSERT(!m_resource);
	m_resource = m_document->cachedResourceLoader()->requestRawResource(newRequest);
	if (m_resource) {
	#if ENABLE(INSPECTOR)
	if (m_resource->loader()) {
	unsigned long identifier = m_actualRequest ? m_preflightRequestIdentifier : m_resource->loader()->identifier();
	InspectorInstrumentation::documentThreadableLoaderStartedLoadingForClient(m_document, identifier, m_client);
	}
	#endif
	m_resource->addClient(this);
	}
	return;
	}

	// FIXME: ThreadableLoaderOptions.sniffContent is not supported for synchronous requests.
	Vector<char> data;
	ResourceError error;
	ResourceResponse response;
	unsigned long identifier = std::numeric_limits<unsigned long>::max();
	if (m_document->frame())
	identifier = m_document->frame()->loader()->loadResourceSynchronously(request, m_options.allowCredentials, error, response, data);

	InspectorInstrumentation::documentThreadableLoaderStartedLoadingForClient(m_document, identifier, m_client);

	// No exception for file:/// resources, see <rdar://problem/4962298>.
	// Also, if we have an HTTP response, then it wasn't a network error in fact.
	if (!error.isNull() && !requestURL.isLocalFile() && response.httpStatusCode() <= 0) {
	m_client->didFail(error);
	return;
	}

	// FIXME: FrameLoader::loadSynchronously() does not tell us whether a redirect happened or not, so we guess by comparing the
	// request and response URLs. This isn't a perfect test though, since a server can serve a redirect to the same URL that was
	// requested. Also comparing the request and response URLs as strings will fail if the requestURL still has its credentials.
	if (requestURL != response.url() && !isAllowedRedirect(response.url())) {
	m_client->didFailRedirectCheck();
	return;
	}

	didReceiveResponse(identifier, response);

	const char* bytes = static_cast<const char*>(data.data());
	int len = static_cast<int>(data.size());
	dataReceived(0, bytes, len);

	didFinishLoading(identifier, 0.0);
	}

	bool DocumentThreadableLoader::isAllowedRedirect(const KURL& url)
	{
	if (m_options.crossOriginRequestPolicy == AllowCrossOriginRequests)
	return true;

	return m_sameOriginRequest && securityOrigin()->canRequest(url);
	}

	SecurityOrigin* DocumentThreadableLoader::securityOrigin() const
	{
	return m_options.securityOrigin ? m_options.securityOrigin.get() : m_document->securityOrigin();
	}

	} // namespace WebCore