net/websockets/websocket_stream.cc - chromium/src - Git at Google

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include "net/websockets/websocket_stream.h"

 #include <utility>

 #include "base/logging.h"
 #include "base/metrics/histogram_functions.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "net/base/load_flags.h"
 #include "net/base/url_util.h"
 #include "net/http/http_request_headers.h"
 #include "net/http/http_response_headers.h"
 #include "net/http/http_status_code.h"
 #include "net/traffic_annotation/network_traffic_annotation.h"
 #include "net/url_request/redirect_info.h"
 #include "net/url_request/url_request.h"
 #include "net/url_request/url_request_context.h"
 #include "net/websockets/websocket_errors.h"
 #include "net/websockets/websocket_event_interface.h"
 #include "net/websockets/websocket_handshake_constants.h"
 #include "net/websockets/websocket_handshake_stream_base.h"
 #include "net/websockets/websocket_handshake_stream_create_helper.h"
 #include "url/gurl.h"
 #include "url/origin.h"

 namespace {

 constexpr net::NetworkTrafficAnnotationTag kTrafficAnnotation =
     net::DefineNetworkTrafficAnnotation("websocket_stream", R"(
         semantics {
           sender: "WebSocket Handshake"
           description:
             "Renderer process initiated WebSocket handshake. The WebSocket "
             "handshake is used to establish a connection between a web page "
             "and a consenting server for bi-directional communication."
           trigger:
             "A handshake is performed every time a new connection is "
             "established via the Javascript or PPAPI WebSocket API. Any web "
             "page or extension can create a WebSocket connection."
           data: "The path and sub-protocols requested when the WebSocket was "
                 "created, plus the origin of the creating page."
           destination: OTHER
         }
         policy {
           cookies_allowed: YES
           cookies_store: "user or per-app cookie store"
           setting: "These requests cannot be disabled."
           policy_exception_justification:
             "Not implemented. WebSocket is a core web platform API."
         })");

 }  // namespace

 namespace net {
 namespace {

 // The timeout duration of WebSocket handshake.
 // It is defined as the same value as the TCP connection timeout value in
 // net/socket/websocket_transport_client_socket_pool.cc to make it hard for
 // JavaScript programs to recognize the timeout cause.
 const int kHandshakeTimeoutIntervalInSeconds = 240;

 class WebSocketStreamRequestImpl;

 class Delegate : public URLRequest::Delegate {
  public:
   enum HandshakeResult {
     INCOMPLETE,
     CONNECTED,
     FAILED,
     NUM_HANDSHAKE_RESULT_TYPES,
   };

   explicit Delegate(WebSocketStreamRequestImpl* owner)
       : owner_(owner), result_(INCOMPLETE) {}
   ~Delegate() override {
     UMA_HISTOGRAM_ENUMERATION(
         "Net.WebSocket.HandshakeResult", result_, NUM_HANDSHAKE_RESULT_TYPES);
   }

   // Implementation of URLRequest::Delegate methods.
   void OnReceivedRedirect(URLRequest* request,
                           const RedirectInfo& redirect_info,
                           bool* defer_redirect) override;

   void OnResponseStarted(URLRequest* request, int net_error) override;

   void OnAuthRequired(URLRequest* request,
                       AuthChallengeInfo* auth_info) override;

   void OnCertificateRequested(URLRequest* request,
                               SSLCertRequestInfo* cert_request_info) override;

   void OnSSLCertificateError(URLRequest* request,
                              const SSLInfo& ssl_info,
                              bool fatal) override;

   void OnReadCompleted(URLRequest* request, int bytes_read) override;

  private:
   WebSocketStreamRequestImpl* owner_;
   HandshakeResult result_;
 };

 class WebSocketStreamRequestImpl : public WebSocketStreamRequest {
  public:
   WebSocketStreamRequestImpl(
       const GURL& url,
       const URLRequestContext* context,
       const url::Origin& origin,
       const GURL& site_for_cookies,
       const std::string& additional_headers,
       std::unique_ptr<WebSocketStream::ConnectDelegate> connect_delegate,
       std::unique_ptr<WebSocketHandshakeStreamCreateHelper> create_helper)
       : delegate_(new Delegate(this)),
         url_request_(context->CreateRequest(url,
                                             DEFAULT_PRIORITY,
                                             delegate_.get(),
                                             kTrafficAnnotation)),
         connect_delegate_(std::move(connect_delegate)),
         handshake_stream_(nullptr) {
     create_helper->set_stream_request(this);
     HttpRequestHeaders headers;
     headers.SetHeader(websockets::kUpgrade, websockets::kWebSocketLowercase);
     headers.SetHeader(HttpRequestHeaders::kConnection, websockets::kUpgrade);
     headers.SetHeader(HttpRequestHeaders::kOrigin, origin.Serialize());
     headers.SetHeader(websockets::kSecWebSocketVersion,
                       websockets::kSupportedVersion);

     headers.AddHeadersFromString(additional_headers);

     url_request_->SetExtraRequestHeaders(headers);
     url_request_->set_initiator(origin);
     url_request_->set_site_for_cookies(site_for_cookies);

     url_request_->SetUserData(
         WebSocketHandshakeStreamBase::CreateHelper::DataKey(),
         std::move(create_helper));
     url_request_->SetLoadFlags(LOAD_DISABLE_CACHE | LOAD_BYPASS_CACHE);
     connect_delegate_->OnCreateRequest(url_request_.get());
   }

   // Destroying this object destroys the URLRequest, which cancels the request
   // and so terminates the handshake if it is incomplete.
   ~WebSocketStreamRequestImpl() override = default;

   void OnHandshakeStreamCreated(
       WebSocketHandshakeStreamBase* handshake_stream) override {
     handshake_stream_ = handshake_stream;
   }

   void OnFailure(const std::string& message) override {
     failure_message_ = message;
   }

   void Start(std::unique_ptr<base::Timer> timer) {
     DCHECK(timer);
     base::TimeDelta timeout(base::TimeDelta::FromSeconds(
         kHandshakeTimeoutIntervalInSeconds));
     timer_ = std::move(timer);
     timer_->Start(FROM_HERE, timeout,
                   base::Bind(&WebSocketStreamRequestImpl::OnTimeout,
                              base::Unretained(this)));
     url_request_->Start();
   }

   void PerformUpgrade() {
     DCHECK(timer_);
     DCHECK(handshake_stream_);

     timer_->Stop();

     std::unique_ptr<URLRequest> url_request = std::move(url_request_);
     WebSocketHandshakeStreamBase* handshake_stream = handshake_stream_;
     handshake_stream_ = nullptr;
     connect_delegate_->OnSuccess(handshake_stream->Upgrade());

     // This is safe even if |this| has already been deleted.
     url_request->CancelWithError(ERR_WS_UPGRADE);
   }

   std::string FailureMessageFromNetError(int net_error) {
     if (net_error == ERR_TUNNEL_CONNECTION_FAILED) {
       // This error is common and confusing, so special-case it.
       // TODO(ricea): Include the HostPortPair of the selected proxy server in
       // the error message. This is not currently possible because it isn't set
       // in HttpResponseInfo when a ERR_TUNNEL_CONNECTION_FAILED error happens.
       return "Establishing a tunnel via proxy server failed.";
     } else {
       return std::string("Error in connection establishment: ") +
              ErrorToString(net_error);
     }
   }

   void ReportFailure(int net_error) {
     DCHECK(timer_);
     timer_->Stop();
     if (failure_message_.empty()) {
       switch (net_error) {
         case OK:
         case ERR_IO_PENDING:
           break;
         case ERR_ABORTED:
           failure_message_ = "WebSocket opening handshake was canceled";
           break;
         case ERR_TIMED_OUT:
           failure_message_ = "WebSocket opening handshake timed out";
           break;
         default:
           failure_message_ = FailureMessageFromNetError(net_error);
           break;
       }
     }
     ReportFailureWithMessage(failure_message_);
   }

   void ReportFailureWithMessage(const std::string& failure_message) {
     connect_delegate_->OnFailure(failure_message);
   }

   void OnFinishOpeningHandshake() {
     WebSocketDispatchOnFinishOpeningHandshake(connect_delegate(),
                                               url_request_->url(),
                                               url_request_->response_headers(),
                                               url_request_->response_time());
   }

   WebSocketStream::ConnectDelegate* connect_delegate() const {
     return connect_delegate_.get();
   }

   void OnTimeout() {
     url_request_->CancelWithError(ERR_TIMED_OUT);
   }

  private:
   // |delegate_| needs to be declared before |url_request_| so that it gets
   // initialised first.
   std::unique_ptr<Delegate> delegate_;

   // Deleting the WebSocketStreamRequestImpl object deletes this URLRequest
   // object, cancelling the whole connection.
   std::unique_ptr<URLRequest> url_request_;

   std::unique_ptr<WebSocketStream::ConnectDelegate> connect_delegate_;

   // This is owned by the caller of
   // WebsocketHandshakeStreamCreateHelper::CreateBaseStream().  Both the stream
   // and this object will be destroyed during the destruction of the URLRequest
   // object associated with the handshake. This is only guaranteed to be a valid
   // pointer if the handshake succeeded.
   WebSocketHandshakeStreamBase* handshake_stream_;

   // The failure message supplied by WebSocketBasicHandshakeStream, if any.
   std::string failure_message_;

   // A timer for handshake timeout.
   std::unique_ptr<base::Timer> timer_;
 };

 class SSLErrorCallbacks : public WebSocketEventInterface::SSLErrorCallbacks {
  public:
   explicit SSLErrorCallbacks(URLRequest* url_request)
       : url_request_(url_request) {}

   void CancelSSLRequest(int error, const SSLInfo* ssl_info) override {
     if (ssl_info) {
       url_request_->CancelWithSSLError(error, *ssl_info);
     } else {
       url_request_->CancelWithError(error);
     }
   }

   void ContinueSSLRequest() override {
     url_request_->ContinueDespiteLastError();
   }

  private:
   URLRequest* url_request_;
 };

 void Delegate::OnReceivedRedirect(URLRequest* request,
                                   const RedirectInfo& redirect_info,
                                   bool* defer_redirect) {
   // This code should never be reached for externally generated redirects,
   // as WebSocketBasicHandshakeStream is responsible for filtering out
   // all response codes besides 101, 401, and 407. As such, the URLRequest
   // should never see a redirect sent over the network. However, internal
   // redirects also result in this method being called, such as those
   // caused by HSTS.
   // Because it's security critical to prevent externally-generated
   // redirects in WebSockets, perform additional checks to ensure this
   // is only internal.
   GURL::Replacements replacements;
   replacements.SetSchemeStr("wss");
   GURL expected_url = request->original_url().ReplaceComponents(replacements);
   if (redirect_info.new_method != "GET" ||
       redirect_info.new_url != expected_url) {
     // This should not happen.
     DLOG(FATAL) << "Unauthorized WebSocket redirect to "
                 << redirect_info.new_method << " "
                 << redirect_info.new_url.spec();
     request->Cancel();
   }
 }

 void Delegate::OnResponseStarted(URLRequest* request, int net_error) {
   DCHECK_NE(ERR_IO_PENDING, net_error);
   // All error codes, including OK and ABORTED, as with
   // Net.ErrorCodesForMainFrame3
   base::UmaHistogramSparse("Net.WebSocket.ErrorCodes", -net_error);
   if (net::IsLocalhost(request->url())) {
     base::UmaHistogramSparse("Net.WebSocket.ErrorCodes_Localhost", -net_error);
   } else {
     base::UmaHistogramSparse("Net.WebSocket.ErrorCodes_NotLocalhost",
                              -net_error);
   }

   if (net_error != OK) {
     DVLOG(3) << "OnResponseStarted (request failed)";
     owner_->ReportFailure(net_error);
     return;
   }
   const int response_code = request->GetResponseCode();
   DVLOG(3) << "OnResponseStarted (response code " << response_code << ")";
   switch (response_code) {
     case HTTP_SWITCHING_PROTOCOLS:
       result_ = CONNECTED;
       owner_->PerformUpgrade();
       return;

     case HTTP_UNAUTHORIZED:
       result_ = FAILED;
       owner_->OnFinishOpeningHandshake();
       owner_->ReportFailureWithMessage(
           "HTTP Authentication failed; no valid credentials available");
       return;

     case HTTP_PROXY_AUTHENTICATION_REQUIRED:
       result_ = FAILED;
       owner_->OnFinishOpeningHandshake();
       owner_->ReportFailureWithMessage("Proxy authentication failed");
       return;

     default:
       result_ = FAILED;
       owner_->ReportFailure(net_error);
   }
 }

 void Delegate::OnAuthRequired(URLRequest* request,
                               AuthChallengeInfo* auth_info) {
   // This should only be called if credentials are not already stored.
   request->CancelAuth();
 }

 void Delegate::OnCertificateRequested(URLRequest* request,
                                       SSLCertRequestInfo* cert_request_info) {
   // This method is called when a client certificate is requested, and the
   // request context does not already contain a client certificate selection for
   // the endpoint. In this case, a main frame resource request would pop-up UI
   // to permit selection of a client certificate, but since WebSockets are
   // sub-resources they should not pop-up UI and so there is nothing more we can
   // do.
   request->Cancel();
 }

 void Delegate::OnSSLCertificateError(URLRequest* request,
                                      const SSLInfo& ssl_info,
                                      bool fatal) {
   owner_->connect_delegate()->OnSSLCertificateError(
       std::unique_ptr<WebSocketEventInterface::SSLErrorCallbacks>(
           new SSLErrorCallbacks(request)),
       ssl_info, fatal);
 }

 void Delegate::OnReadCompleted(URLRequest* request, int bytes_read) {
   NOTREACHED();
 }

 }  // namespace

 WebSocketStreamRequest::~WebSocketStreamRequest() = default;

 WebSocketStream::WebSocketStream() = default;
 WebSocketStream::~WebSocketStream() = default;

 WebSocketStream::ConnectDelegate::~ConnectDelegate() = default;

 std::unique_ptr<WebSocketStreamRequest> WebSocketStream::CreateAndConnectStream(
     const GURL& socket_url,
     std::unique_ptr<WebSocketHandshakeStreamCreateHelper> create_helper,
     const url::Origin& origin,
     const GURL& site_for_cookies,
     const std::string& additional_headers,
     URLRequestContext* url_request_context,
     const NetLogWithSource& net_log,
     std::unique_ptr<ConnectDelegate> connect_delegate) {
   std::unique_ptr<WebSocketStreamRequestImpl> request(
       new WebSocketStreamRequestImpl(socket_url, url_request_context, origin,
                                      site_for_cookies, additional_headers,
                                      std::move(connect_delegate),
                                      std::move(create_helper)));
   request->Start(std::unique_ptr<base::Timer>(new base::Timer(false, false)));
   return std::move(request);
 }

 std::unique_ptr<WebSocketStreamRequest>
 WebSocketStream::CreateAndConnectStreamForTesting(
     const GURL& socket_url,
     std::unique_ptr<WebSocketHandshakeStreamCreateHelper> create_helper,
     const url::Origin& origin,
     const GURL& site_for_cookies,
     const std::string& additional_headers,
     URLRequestContext* url_request_context,
     const NetLogWithSource& net_log,
     std::unique_ptr<WebSocketStream::ConnectDelegate> connect_delegate,
     std::unique_ptr<base::Timer> timer) {
   std::unique_ptr<WebSocketStreamRequestImpl> request(
       new WebSocketStreamRequestImpl(socket_url, url_request_context, origin,
                                      site_for_cookies, additional_headers,
                                      std::move(connect_delegate),
                                      std::move(create_helper)));
   request->Start(std::move(timer));
   return std::move(request);
 }

 void WebSocketDispatchOnFinishOpeningHandshake(
     WebSocketStream::ConnectDelegate* connect_delegate,
     const GURL& url,
     const scoped_refptr<HttpResponseHeaders>& headers,
     base::Time response_time) {
   DCHECK(connect_delegate);
   if (headers.get()) {
     connect_delegate->OnFinishOpeningHandshake(
         std::make_unique<WebSocketHandshakeResponseInfo>(
             url, headers->response_code(), headers->GetStatusText(), headers,
             response_time));
   }
 }

 }  // namespace net
	// Copyright 2013 The Chromium Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#include "net/websockets/websocket_stream.h"

	#include <utility>

	#include "base/logging.h"
	#include "base/metrics/histogram_functions.h"
	#include "base/metrics/histogram_macros.h"
	#include "base/time/time.h"
	#include "base/timer/timer.h"
	#include "net/base/load_flags.h"
	#include "net/base/url_util.h"
	#include "net/http/http_request_headers.h"
	#include "net/http/http_response_headers.h"
	#include "net/http/http_status_code.h"
	#include "net/traffic_annotation/network_traffic_annotation.h"
	#include "net/url_request/redirect_info.h"
	#include "net/url_request/url_request.h"
	#include "net/url_request/url_request_context.h"
	#include "net/websockets/websocket_errors.h"
	#include "net/websockets/websocket_event_interface.h"
	#include "net/websockets/websocket_handshake_constants.h"
	#include "net/websockets/websocket_handshake_stream_base.h"
	#include "net/websockets/websocket_handshake_stream_create_helper.h"
	#include "url/gurl.h"
	#include "url/origin.h"

	namespace {

	constexpr net::NetworkTrafficAnnotationTag kTrafficAnnotation =
	net::DefineNetworkTrafficAnnotation("websocket_stream", R"(
	semantics {
	sender: "WebSocket Handshake"
	description:
	"Renderer process initiated WebSocket handshake. The WebSocket "
	"handshake is used to establish a connection between a web page "
	"and a consenting server for bi-directional communication."
	trigger:
	"A handshake is performed every time a new connection is "
	"established via the Javascript or PPAPI WebSocket API. Any web "
	"page or extension can create a WebSocket connection."
	data: "The path and sub-protocols requested when the WebSocket was "
	"created, plus the origin of the creating page."
	destination: OTHER
	}
	policy {
	cookies_allowed: YES
	cookies_store: "user or per-app cookie store"
	setting: "These requests cannot be disabled."
	policy_exception_justification:
	"Not implemented. WebSocket is a core web platform API."
	})");

	} // namespace

	namespace net {
	namespace {

	// The timeout duration of WebSocket handshake.
	// It is defined as the same value as the TCP connection timeout value in
	// net/socket/websocket_transport_client_socket_pool.cc to make it hard for
	// JavaScript programs to recognize the timeout cause.
	const int kHandshakeTimeoutIntervalInSeconds = 240;

	class WebSocketStreamRequestImpl;

	class Delegate : public URLRequest::Delegate {
	public:
	enum HandshakeResult {
	INCOMPLETE,
	CONNECTED,
	FAILED,
	NUM_HANDSHAKE_RESULT_TYPES,
	};

	explicit Delegate(WebSocketStreamRequestImpl* owner)
	: owner_(owner), result_(INCOMPLETE) {}
	~Delegate() override {
	UMA_HISTOGRAM_ENUMERATION(
	"Net.WebSocket.HandshakeResult", result_, NUM_HANDSHAKE_RESULT_TYPES);
	}

	// Implementation of URLRequest::Delegate methods.
	void OnReceivedRedirect(URLRequest* request,
	const RedirectInfo& redirect_info,
	bool* defer_redirect) override;

	void OnResponseStarted(URLRequest* request, int net_error) override;

	void OnAuthRequired(URLRequest* request,
	AuthChallengeInfo* auth_info) override;

	void OnCertificateRequested(URLRequest* request,
	SSLCertRequestInfo* cert_request_info) override;

	void OnSSLCertificateError(URLRequest* request,
	const SSLInfo& ssl_info,
	bool fatal) override;

	void OnReadCompleted(URLRequest* request, int bytes_read) override;

	private:
	WebSocketStreamRequestImpl* owner_;
	HandshakeResult result_;
	};

	class WebSocketStreamRequestImpl : public WebSocketStreamRequest {
	public:
	WebSocketStreamRequestImpl(
	const GURL& url,
	const URLRequestContext* context,
	const url::Origin& origin,
	const GURL& site_for_cookies,
	const std::string& additional_headers,
	std::unique_ptr<WebSocketStream::ConnectDelegate> connect_delegate,
	std::unique_ptr<WebSocketHandshakeStreamCreateHelper> create_helper)
	: delegate_(new Delegate(this)),
	url_request_(context->CreateRequest(url,
	DEFAULT_PRIORITY,
	delegate_.get(),
	kTrafficAnnotation)),
	connect_delegate_(std::move(connect_delegate)),
	handshake_stream_(nullptr) {
	create_helper->set_stream_request(this);
	HttpRequestHeaders headers;
	headers.SetHeader(websockets::kUpgrade, websockets::kWebSocketLowercase);
	headers.SetHeader(HttpRequestHeaders::kConnection, websockets::kUpgrade);
	headers.SetHeader(HttpRequestHeaders::kOrigin, origin.Serialize());
	headers.SetHeader(websockets::kSecWebSocketVersion,
	websockets::kSupportedVersion);

	headers.AddHeadersFromString(additional_headers);

	url_request_->SetExtraRequestHeaders(headers);
	url_request_->set_initiator(origin);
	url_request_->set_site_for_cookies(site_for_cookies);

	url_request_->SetUserData(
	WebSocketHandshakeStreamBase::CreateHelper::DataKey(),
	std::move(create_helper));
	url_request_->SetLoadFlags(LOAD_DISABLE_CACHE \| LOAD_BYPASS_CACHE);
	connect_delegate_->OnCreateRequest(url_request_.get());
	}

	// Destroying this object destroys the URLRequest, which cancels the request
	// and so terminates the handshake if it is incomplete.
	~WebSocketStreamRequestImpl() override = default;

	void OnHandshakeStreamCreated(
	WebSocketHandshakeStreamBase* handshake_stream) override {
	handshake_stream_ = handshake_stream;
	}

	void OnFailure(const std::string& message) override {
	failure_message_ = message;
	}

	void Start(std::unique_ptr<base::Timer> timer) {
	DCHECK(timer);
	base::TimeDelta timeout(base::TimeDelta::FromSeconds(
	kHandshakeTimeoutIntervalInSeconds));
	timer_ = std::move(timer);
	timer_->Start(FROM_HERE, timeout,
	base::Bind(&WebSocketStreamRequestImpl::OnTimeout,
	base::Unretained(this)));
	url_request_->Start();
	}

	void PerformUpgrade() {
	DCHECK(timer_);
	DCHECK(handshake_stream_);

	timer_->Stop();

	std::unique_ptr<URLRequest> url_request = std::move(url_request_);
	WebSocketHandshakeStreamBase* handshake_stream = handshake_stream_;
	handshake_stream_ = nullptr;
	connect_delegate_->OnSuccess(handshake_stream->Upgrade());

	// This is safe even if \|this\| has already been deleted.
	url_request->CancelWithError(ERR_WS_UPGRADE);
	}

	std::string FailureMessageFromNetError(int net_error) {
	if (net_error == ERR_TUNNEL_CONNECTION_FAILED) {
	// This error is common and confusing, so special-case it.
	// TODO(ricea): Include the HostPortPair of the selected proxy server in
	// the error message. This is not currently possible because it isn't set
	// in HttpResponseInfo when a ERR_TUNNEL_CONNECTION_FAILED error happens.
	return "Establishing a tunnel via proxy server failed.";
	} else {
	return std::string("Error in connection establishment: ") +
	ErrorToString(net_error);
	}
	}

	void ReportFailure(int net_error) {
	DCHECK(timer_);
	timer_->Stop();
	if (failure_message_.empty()) {
	switch (net_error) {
	case OK:
	case ERR_IO_PENDING:
	break;
	case ERR_ABORTED:
	failure_message_ = "WebSocket opening handshake was canceled";
	break;
	case ERR_TIMED_OUT:
	failure_message_ = "WebSocket opening handshake timed out";
	break;
	default:
	failure_message_ = FailureMessageFromNetError(net_error);
	break;
	}
	}
	ReportFailureWithMessage(failure_message_);
	}

	void ReportFailureWithMessage(const std::string& failure_message) {
	connect_delegate_->OnFailure(failure_message);
	}

	void OnFinishOpeningHandshake() {
	WebSocketDispatchOnFinishOpeningHandshake(connect_delegate(),
	url_request_->url(),
	url_request_->response_headers(),
	url_request_->response_time());
	}

	WebSocketStream::ConnectDelegate* connect_delegate() const {
	return connect_delegate_.get();
	}

	void OnTimeout() {
	url_request_->CancelWithError(ERR_TIMED_OUT);
	}

	private:
	// \|delegate_\| needs to be declared before \|url_request_\| so that it gets
	// initialised first.
	std::unique_ptr<Delegate> delegate_;

	// Deleting the WebSocketStreamRequestImpl object deletes this URLRequest
	// object, cancelling the whole connection.
	std::unique_ptr<URLRequest> url_request_;

	std::unique_ptr<WebSocketStream::ConnectDelegate> connect_delegate_;

	// This is owned by the caller of
	// WebsocketHandshakeStreamCreateHelper::CreateBaseStream(). Both the stream
	// and this object will be destroyed during the destruction of the URLRequest
	// object associated with the handshake. This is only guaranteed to be a valid
	// pointer if the handshake succeeded.
	WebSocketHandshakeStreamBase* handshake_stream_;

	// The failure message supplied by WebSocketBasicHandshakeStream, if any.
	std::string failure_message_;

	// A timer for handshake timeout.
	std::unique_ptr<base::Timer> timer_;
	};

	class SSLErrorCallbacks : public WebSocketEventInterface::SSLErrorCallbacks {
	public:
	explicit SSLErrorCallbacks(URLRequest* url_request)
	: url_request_(url_request) {}

	void CancelSSLRequest(int error, const SSLInfo* ssl_info) override {
	if (ssl_info) {
	url_request_->CancelWithSSLError(error, *ssl_info);
	} else {
	url_request_->CancelWithError(error);
	}
	}

	void ContinueSSLRequest() override {
	url_request_->ContinueDespiteLastError();
	}

	private:
	URLRequest* url_request_;
	};

	void Delegate::OnReceivedRedirect(URLRequest* request,
	const RedirectInfo& redirect_info,
	bool* defer_redirect) {
	// This code should never be reached for externally generated redirects,
	// as WebSocketBasicHandshakeStream is responsible for filtering out
	// all response codes besides 101, 401, and 407. As such, the URLRequest
	// should never see a redirect sent over the network. However, internal
	// redirects also result in this method being called, such as those
	// caused by HSTS.
	// Because it's security critical to prevent externally-generated
	// redirects in WebSockets, perform additional checks to ensure this
	// is only internal.
	GURL::Replacements replacements;
	replacements.SetSchemeStr("wss");
	GURL expected_url = request->original_url().ReplaceComponents(replacements);
	if (redirect_info.new_method != "GET" \|\|
	redirect_info.new_url != expected_url) {
	// This should not happen.
	DLOG(FATAL) << "Unauthorized WebSocket redirect to "
	<< redirect_info.new_method << " "
	<< redirect_info.new_url.spec();
	request->Cancel();
	}
	}

	void Delegate::OnResponseStarted(URLRequest* request, int net_error) {
	DCHECK_NE(ERR_IO_PENDING, net_error);
	// All error codes, including OK and ABORTED, as with
	// Net.ErrorCodesForMainFrame3
	base::UmaHistogramSparse("Net.WebSocket.ErrorCodes", -net_error);
	if (net::IsLocalhost(request->url())) {
	base::UmaHistogramSparse("Net.WebSocket.ErrorCodes_Localhost", -net_error);
	} else {
	base::UmaHistogramSparse("Net.WebSocket.ErrorCodes_NotLocalhost",
	-net_error);
	}

	if (net_error != OK) {
	DVLOG(3) << "OnResponseStarted (request failed)";
	owner_->ReportFailure(net_error);
	return;
	}
	const int response_code = request->GetResponseCode();
	DVLOG(3) << "OnResponseStarted (response code " << response_code << ")";
	switch (response_code) {
	case HTTP_SWITCHING_PROTOCOLS:
	result_ = CONNECTED;
	owner_->PerformUpgrade();
	return;

	case HTTP_UNAUTHORIZED:
	result_ = FAILED;
	owner_->OnFinishOpeningHandshake();
	owner_->ReportFailureWithMessage(
	"HTTP Authentication failed; no valid credentials available");
	return;

	case HTTP_PROXY_AUTHENTICATION_REQUIRED:
	result_ = FAILED;
	owner_->OnFinishOpeningHandshake();
	owner_->ReportFailureWithMessage("Proxy authentication failed");
	return;

	default:
	result_ = FAILED;
	owner_->ReportFailure(net_error);
	}
	}

	void Delegate::OnAuthRequired(URLRequest* request,
	AuthChallengeInfo* auth_info) {
	// This should only be called if credentials are not already stored.
	request->CancelAuth();
	}

	void Delegate::OnCertificateRequested(URLRequest* request,
	SSLCertRequestInfo* cert_request_info) {
	// This method is called when a client certificate is requested, and the
	// request context does not already contain a client certificate selection for
	// the endpoint. In this case, a main frame resource request would pop-up UI
	// to permit selection of a client certificate, but since WebSockets are
	// sub-resources they should not pop-up UI and so there is nothing more we can
	// do.
	request->Cancel();
	}

	void Delegate::OnSSLCertificateError(URLRequest* request,
	const SSLInfo& ssl_info,
	bool fatal) {
	owner_->connect_delegate()->OnSSLCertificateError(
	std::unique_ptr<WebSocketEventInterface::SSLErrorCallbacks>(
	new SSLErrorCallbacks(request)),
	ssl_info, fatal);
	}

	void Delegate::OnReadCompleted(URLRequest* request, int bytes_read) {
	NOTREACHED();
	}

	} // namespace

	WebSocketStreamRequest::~WebSocketStreamRequest() = default;

	WebSocketStream::WebSocketStream() = default;
	WebSocketStream::~WebSocketStream() = default;

	WebSocketStream::ConnectDelegate::~ConnectDelegate() = default;

	std::unique_ptr<WebSocketStreamRequest> WebSocketStream::CreateAndConnectStream(
	const GURL& socket_url,
	std::unique_ptr<WebSocketHandshakeStreamCreateHelper> create_helper,
	const url::Origin& origin,
	const GURL& site_for_cookies,
	const std::string& additional_headers,
	URLRequestContext* url_request_context,
	const NetLogWithSource& net_log,
	std::unique_ptr<ConnectDelegate> connect_delegate) {
	std::unique_ptr<WebSocketStreamRequestImpl> request(
	new WebSocketStreamRequestImpl(socket_url, url_request_context, origin,
	site_for_cookies, additional_headers,
	std::move(connect_delegate),
	std::move(create_helper)));
	request->Start(std::unique_ptr<base::Timer>(new base::Timer(false, false)));
	return std::move(request);
	}

	std::unique_ptr<WebSocketStreamRequest>
	WebSocketStream::CreateAndConnectStreamForTesting(
	const GURL& socket_url,
	std::unique_ptr<WebSocketHandshakeStreamCreateHelper> create_helper,
	const url::Origin& origin,
	const GURL& site_for_cookies,
	const std::string& additional_headers,
	URLRequestContext* url_request_context,
	const NetLogWithSource& net_log,
	std::unique_ptr<WebSocketStream::ConnectDelegate> connect_delegate,
	std::unique_ptr<base::Timer> timer) {
	std::unique_ptr<WebSocketStreamRequestImpl> request(
	new WebSocketStreamRequestImpl(socket_url, url_request_context, origin,
	site_for_cookies, additional_headers,
	std::move(connect_delegate),
	std::move(create_helper)));
	request->Start(std::move(timer));
	return std::move(request);
	}

	void WebSocketDispatchOnFinishOpeningHandshake(
	WebSocketStream::ConnectDelegate* connect_delegate,
	const GURL& url,
	const scoped_refptr<HttpResponseHeaders>& headers,
	base::Time response_time) {
	DCHECK(connect_delegate);
	if (headers.get()) {
	connect_delegate->OnFinishOpeningHandshake(
	std::make_unique<WebSocketHandshakeResponseInfo>(
	url, headers->response_code(), headers->GetStatusText(), headers,
	response_time));
	}
	}

	} // namespace net