net/websockets/websocket_basic_handshake_stream.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "net/websockets/websocket_basic_handshake_stream.h"
   6
   7 #include <algorithm>
   8 #include <iterator>
   9 #include <set>
  10 #include <string>
  11 #include <vector>
  12
  13 #include "base/base64.h"
  14 #include "base/basictypes.h"
  15 #include "base/bind.h"
  16 #include "base/compiler_specific.h"
  17 #include "base/containers/hash_tables.h"
  18 #include "base/logging.h"
  19 #include "base/metrics/histogram_macros.h"
  20 #include "base/metrics/sparse_histogram.h"
  21 #include "base/stl_util.h"
  22 #include "base/strings/string_number_conversions.h"
  23 #include "base/strings/string_piece.h"
  24 #include "base/strings/string_util.h"
  25 #include "base/strings/stringprintf.h"
  26 #include "base/time/time.h"
  27 #include "crypto/random.h"
  28 #include "net/base/io_buffer.h"
  29 #include "net/http/http_request_headers.h"
  30 #include "net/http/http_request_info.h"
  31 #include "net/http/http_response_body_drainer.h"
  32 #include "net/http/http_response_headers.h"
  33 #include "net/http/http_status_code.h"
  34 #include "net/http/http_stream_parser.h"
  35 #include "net/socket/client_socket_handle.h"
  36 #include "net/socket/websocket_transport_client_socket_pool.h"
  37 #include "net/websockets/websocket_basic_stream.h"
  38 #include "net/websockets/websocket_deflate_predictor.h"
  39 #include "net/websockets/websocket_deflate_predictor_impl.h"
  40 #include "net/websockets/websocket_deflate_stream.h"
  41 #include "net/websockets/websocket_deflater.h"
  42 #include "net/websockets/websocket_extension_parser.h"
  43 #include "net/websockets/websocket_handshake_challenge.h"
  44 #include "net/websockets/websocket_handshake_constants.h"
  45 #include "net/websockets/websocket_handshake_request_info.h"
  46 #include "net/websockets/websocket_handshake_response_info.h"
  47 #include "net/websockets/websocket_stream.h"
  48
  49 namespace net {
  50
  51 namespace {
  52
  53 const char kConnectionErrorStatusLine[] = "HTTP/1.1 503 Connection Error";
  54
  55 }  // namespace
  56
  57 // TODO(ricea): If more extensions are added, replace this with a more general
  58 // mechanism.
  59 struct WebSocketExtensionParams {
  60   WebSocketExtensionParams()
  61       : deflate_enabled(false),
  62         client_window_bits(15),
  63         deflate_mode(WebSocketDeflater::TAKE_OVER_CONTEXT) {}
  64
  65   bool deflate_enabled;
  66   int client_window_bits;
  67   WebSocketDeflater::ContextTakeOverMode deflate_mode;
  68 };
  69
  70 namespace {
  71
  72 enum GetHeaderResult {
  73   GET_HEADER_OK,
  74   GET_HEADER_MISSING,
  75   GET_HEADER_MULTIPLE,
  76 };
  77
  78 std::string MissingHeaderMessage(const std::string& header_name) {
  79   return std::string("'") + header_name + "' header is missing";
  80 }
  81
  82 std::string MultipleHeaderValuesMessage(const std::string& header_name) {
  83   return
  84       std::string("'") +
  85       header_name +
  86       "' header must not appear more than once in a response";
  87 }
  88
  89 std::string GenerateHandshakeChallenge() {
  90   std::string raw_challenge(websockets::kRawChallengeLength, '\0');
  91   crypto::RandBytes(string_as_array(&raw_challenge), raw_challenge.length());
  92   std::string encoded_challenge;
  93   base::Base64Encode(raw_challenge, &encoded_challenge);
  94   return encoded_challenge;
  95 }
  96
  97 void AddVectorHeaderIfNonEmpty(const char* name,
  98                                const std::vector<std::string>& value,
  99                                HttpRequestHeaders* headers) {
 100   if (value.empty())
 101     return;
 102   headers->SetHeader(name, base::JoinString(value, ", "));
 103 }
 104
 105 GetHeaderResult GetSingleHeaderValue(const HttpResponseHeaders* headers,
 106                                      const base::StringPiece& name,
 107                                      std::string* value) {
 108   void* state = nullptr;
 109   size_t num_values = 0;
 110   std::string temp_value;
 111   while (headers->EnumerateHeader(&state, name, &temp_value)) {
 112     if (++num_values > 1)
 113       return GET_HEADER_MULTIPLE;
 114     *value = temp_value;
 115   }
 116   return num_values > 0 ? GET_HEADER_OK : GET_HEADER_MISSING;
 117 }
 118
 119 bool ValidateHeaderHasSingleValue(GetHeaderResult result,
 120                                   const std::string& header_name,
 121                                   std::string* failure_message) {
 122   if (result == GET_HEADER_MISSING) {
 123     *failure_message = MissingHeaderMessage(header_name);
 124     return false;
 125   }
 126   if (result == GET_HEADER_MULTIPLE) {
 127     *failure_message = MultipleHeaderValuesMessage(header_name);
 128     return false;
 129   }
 130   DCHECK_EQ(result, GET_HEADER_OK);
 131   return true;
 132 }
 133
 134 bool ValidateUpgrade(const HttpResponseHeaders* headers,
 135                      std::string* failure_message) {
 136   std::string value;
 137   GetHeaderResult result =
 138       GetSingleHeaderValue(headers, websockets::kUpgrade, &value);
 139   if (!ValidateHeaderHasSingleValue(result,
 140                                     websockets::kUpgrade,
 141                                     failure_message)) {
 142     return false;
 143   }
 144
 145   if (!base::LowerCaseEqualsASCII(value, websockets::kWebSocketLowercase)) {
 146     *failure_message =
 147         "'Upgrade' header value is not 'WebSocket': " + value;
 148     return false;
 149   }
 150   return true;
 151 }
 152
 153 bool ValidateSecWebSocketAccept(const HttpResponseHeaders* headers,
 154                                 const std::string& expected,
 155                                 std::string* failure_message) {
 156   std::string actual;
 157   GetHeaderResult result =
 158       GetSingleHeaderValue(headers, websockets::kSecWebSocketAccept, &actual);
 159   if (!ValidateHeaderHasSingleValue(result,
 160                                     websockets::kSecWebSocketAccept,
 161                                     failure_message)) {
 162     return false;
 163   }
 164
 165   if (expected != actual) {
 166     *failure_message = "Incorrect 'Sec-WebSocket-Accept' header value";
 167     return false;
 168   }
 169   return true;
 170 }
 171
 172 bool ValidateConnection(const HttpResponseHeaders* headers,
 173                         std::string* failure_message) {
 174   // Connection header is permitted to contain other tokens.
 175   if (!headers->HasHeader(HttpRequestHeaders::kConnection)) {
 176     *failure_message = MissingHeaderMessage(HttpRequestHeaders::kConnection);
 177     return false;
 178   }
 179   if (!headers->HasHeaderValue(HttpRequestHeaders::kConnection,
 180                                websockets::kUpgrade)) {
 181     *failure_message = "'Connection' header value must contain 'Upgrade'";
 182     return false;
 183   }
 184   return true;
 185 }
 186
 187 bool ValidateSubProtocol(
 188     const HttpResponseHeaders* headers,
 189     const std::vector<std::string>& requested_sub_protocols,
 190     std::string* sub_protocol,
 191     std::string* failure_message) {
 192   void* state = nullptr;
 193   std::string value;
 194   base::hash_set<std::string> requested_set(requested_sub_protocols.begin(),
 195                                             requested_sub_protocols.end());
 196   int count = 0;
 197   bool has_multiple_protocols = false;
 198   bool has_invalid_protocol = false;
 199
 200   while (!has_invalid_protocol || !has_multiple_protocols) {
 201     std::string temp_value;
 202     if (!headers->EnumerateHeader(
 203             &state, websockets::kSecWebSocketProtocol, &temp_value))
 204       break;
 205     value = temp_value;
 206     if (requested_set.count(value) == 0)
 207       has_invalid_protocol = true;
 208     if (++count > 1)
 209       has_multiple_protocols = true;
 210   }
 211
 212   if (has_multiple_protocols) {
 213     *failure_message =
 214         MultipleHeaderValuesMessage(websockets::kSecWebSocketProtocol);
 215     return false;
 216   } else if (count > 0 && requested_sub_protocols.size() == 0) {
 217     *failure_message =
 218         std::string("Response must not include 'Sec-WebSocket-Protocol' "
 219                     "header if not present in request: ")
 220         + value;
 221     return false;
 222   } else if (has_invalid_protocol) {
 223     *failure_message =
 224         "'Sec-WebSocket-Protocol' header value '" +
 225         value +
 226         "' in response does not match any of sent values";
 227     return false;
 228   } else if (requested_sub_protocols.size() > 0 && count == 0) {
 229     *failure_message =
 230         "Sent non-empty 'Sec-WebSocket-Protocol' header "
 231         "but no response was received";
 232     return false;
 233   }
 234   *sub_protocol = value;
 235   return true;
 236 }
 237
 238 bool DeflateError(std::string* message, const base::StringPiece& piece) {
 239   *message = "Error in permessage-deflate: ";
 240   piece.AppendToString(message);
 241   return false;
 242 }
 243
 244 bool ValidatePerMessageDeflateExtension(const WebSocketExtension& extension,
 245                                         std::string* failure_message,
 246                                         WebSocketExtensionParams* params) {
 247   static const char kClientPrefix[] = "client_";
 248   static const char kServerPrefix[] = "server_";
 249   static const char kNoContextTakeover[] = "no_context_takeover";
 250   static const char kMaxWindowBits[] = "max_window_bits";
 251   const size_t kPrefixLen = arraysize(kClientPrefix) - 1;
 252   static_assert(kPrefixLen == arraysize(kServerPrefix) - 1,
 253                 "the strings server and client must be the same length");
 254   typedef std::vector<WebSocketExtension::Parameter> ParameterVector;
 255
 256   DCHECK_EQ("permessage-deflate", extension.name());
 257   const ParameterVector& parameters = extension.parameters();
 258   std::set<std::string> seen_names;
 259   for (ParameterVector::const_iterator it = parameters.begin();
 260        it != parameters.end(); ++it) {
 261     const std::string& name = it->name();
 262     if (seen_names.count(name) != 0) {
 263       return DeflateError(
 264           failure_message,
 265           "Received duplicate permessage-deflate extension parameter " + name);
 266     }
 267     seen_names.insert(name);
 268     const std::string client_or_server(name, 0, kPrefixLen);
 269     const bool is_client = (client_or_server == kClientPrefix);
 270     if (!is_client && client_or_server != kServerPrefix) {
 271       return DeflateError(
 272           failure_message,
 273           "Received an unexpected permessage-deflate extension parameter");
 274     }
 275     const std::string rest(name, kPrefixLen);
 276     if (rest == kNoContextTakeover) {
 277       if (it->HasValue()) {
 278         return DeflateError(failure_message,
 279                             "Received invalid " + name + " parameter");
 280       }
 281       if (is_client)
 282         params->deflate_mode = WebSocketDeflater::DO_NOT_TAKE_OVER_CONTEXT;
 283     } else if (rest == kMaxWindowBits) {
 284       if (!it->HasValue())
 285         return DeflateError(failure_message, name + " must have value");
 286       int bits = 0;
 287       if (!base::StringToInt(it->value(), &bits) || bits < 8 || bits > 15 ||
 288           it->value()[0] == '0' ||
 289           it->value().find_first_not_of("0123456789") != std::string::npos) {
 290         return DeflateError(failure_message,
 291                             "Received invalid " + name + " parameter");
 292       }
 293       if (is_client)
 294         params->client_window_bits = bits;
 295     } else {
 296       return DeflateError(
 297           failure_message,
 298           "Received an unexpected permessage-deflate extension parameter");
 299     }
 300   }
 301   params->deflate_enabled = true;
 302   return true;
 303 }
 304
 305 bool ValidateExtensions(const HttpResponseHeaders* headers,
 306                         std::string* accepted_extensions_descriptor,
 307                         std::string* failure_message,
 308                         WebSocketExtensionParams* params) {
 309   void* state = nullptr;
 310   std::string header_value;
 311   std::vector<std::string> header_values;
 312   // TODO(ricea): If adding support for additional extensions, generalise this
 313   // code.
 314   bool seen_permessage_deflate = false;
 315   while (headers->EnumerateHeader(&state, websockets::kSecWebSocketExtensions,
 316                                   &header_value)) {
 317     WebSocketExtensionParser parser;
 318     if (!parser.Parse(header_value)) {
 319       // TODO(yhirano) Set appropriate failure message.
 320       *failure_message =
 321           "'Sec-WebSocket-Extensions' header value is "
 322           "rejected by the parser: " +
 323           header_value;
 324       return false;
 325     }
 326
 327     const std::vector<WebSocketExtension>& extensions = parser.extensions();
 328     for (const auto& extension : extensions) {
 329       if (extension.name() == "permessage-deflate") {
 330         if (seen_permessage_deflate) {
 331           *failure_message = "Received duplicate permessage-deflate response";
 332           return false;
 333         }
 334         seen_permessage_deflate = true;
 335
 336         if (!ValidatePerMessageDeflateExtension(extension, failure_message,
 337                                                 params)) {
 338           return false;
 339         }
 340         header_values.push_back(header_value);
 341       } else {
 342         *failure_message = "Found an unsupported extension '" +
 343                            extension.name() +
 344                            "' in 'Sec-WebSocket-Extensions' header";
 345         return false;
 346       }
 347     }
 348   }
 349   *accepted_extensions_descriptor = base::JoinString(header_values, ", ");
 350   return true;
 351 }
 352
 353 }  // namespace
 354
 355 WebSocketBasicHandshakeStream::WebSocketBasicHandshakeStream(
 356     scoped_ptr<ClientSocketHandle> connection,
 357     WebSocketStream::ConnectDelegate* connect_delegate,
 358     bool using_proxy,
 359     std::vector<std::string> requested_sub_protocols,
 360     std::vector<std::string> requested_extensions,
 361     std::string* failure_message)
 362     : state_(connection.release(), using_proxy),
 363       connect_delegate_(connect_delegate),
 364       http_response_info_(nullptr),
 365       requested_sub_protocols_(requested_sub_protocols),
 366       requested_extensions_(requested_extensions),
 367       failure_message_(failure_message) {
 368   DCHECK(connect_delegate);
 369   DCHECK(failure_message);
 370 }
 371
 372 WebSocketBasicHandshakeStream::~WebSocketBasicHandshakeStream() {}
 373
 374 int WebSocketBasicHandshakeStream::InitializeStream(
 375     const HttpRequestInfo* request_info,
 376     RequestPriority priority,
 377     const BoundNetLog& net_log,
 378     const CompletionCallback& callback) {
 379   url_ = request_info->url;
 380   state_.Initialize(request_info, priority, net_log, callback);
 381   return OK;
 382 }
 383
 384 int WebSocketBasicHandshakeStream::SendRequest(
 385     const HttpRequestHeaders& headers,
 386     HttpResponseInfo* response,
 387     const CompletionCallback& callback) {
 388   DCHECK(!headers.HasHeader(websockets::kSecWebSocketKey));
 389   DCHECK(!headers.HasHeader(websockets::kSecWebSocketProtocol));
 390   DCHECK(!headers.HasHeader(websockets::kSecWebSocketExtensions));
 391   DCHECK(headers.HasHeader(HttpRequestHeaders::kOrigin));
 392   DCHECK(headers.HasHeader(websockets::kUpgrade));
 393   DCHECK(headers.HasHeader(HttpRequestHeaders::kConnection));
 394   DCHECK(headers.HasHeader(websockets::kSecWebSocketVersion));
 395   DCHECK(parser());
 396
 397   http_response_info_ = response;
 398
 399   // Create a copy of the headers object, so that we can add the
 400   // Sec-WebSockey-Key header.
 401   HttpRequestHeaders enriched_headers;
 402   enriched_headers.CopyFrom(headers);
 403   std::string handshake_challenge;
 404   if (handshake_challenge_for_testing_) {
 405     handshake_challenge = *handshake_challenge_for_testing_;
 406     handshake_challenge_for_testing_.reset();
 407   } else {
 408     handshake_challenge = GenerateHandshakeChallenge();
 409   }
 410   enriched_headers.SetHeader(websockets::kSecWebSocketKey, handshake_challenge);
 411
 412   AddVectorHeaderIfNonEmpty(websockets::kSecWebSocketExtensions,
 413                             requested_extensions_,
 414                             &enriched_headers);
 415   AddVectorHeaderIfNonEmpty(websockets::kSecWebSocketProtocol,
 416                             requested_sub_protocols_,
 417                             &enriched_headers);
 418
 419   handshake_challenge_response_ =
 420       ComputeSecWebSocketAccept(handshake_challenge);
 421
 422   DCHECK(connect_delegate_);
 423   scoped_ptr<WebSocketHandshakeRequestInfo> request(
 424       new WebSocketHandshakeRequestInfo(url_, base::Time::Now()));
 425   request->headers.CopyFrom(enriched_headers);
 426   connect_delegate_->OnStartOpeningHandshake(request.Pass());
 427
 428   return parser()->SendRequest(
 429       state_.GenerateRequestLine(), enriched_headers, response, callback);
 430 }
 431
 432 int WebSocketBasicHandshakeStream::ReadResponseHeaders(
 433     const CompletionCallback& callback) {
 434   // HttpStreamParser uses a weak pointer when reading from the
 435   // socket, so it won't be called back after being destroyed. The
 436   // HttpStreamParser is owned by HttpBasicState which is owned by this object,
 437   // so this use of base::Unretained() is safe.
 438   int rv = parser()->ReadResponseHeaders(
 439       base::Bind(&WebSocketBasicHandshakeStream::ReadResponseHeadersCallback,
 440                  base::Unretained(this),
 441                  callback));
 442   if (rv == ERR_IO_PENDING)
 443     return rv;
 444   return ValidateResponse(rv);
 445 }
 446
 447 int WebSocketBasicHandshakeStream::ReadResponseBody(
 448     IOBuffer* buf,
 449     int buf_len,
 450     const CompletionCallback& callback) {
 451   return parser()->ReadResponseBody(buf, buf_len, callback);
 452 }
 453
 454 void WebSocketBasicHandshakeStream::Close(bool not_reusable) {
 455   // This class ignores the value of |not_reusable| and never lets the socket be
 456   // re-used.
 457   if (parser())
 458     parser()->Close(true);
 459 }
 460
 461 bool WebSocketBasicHandshakeStream::IsResponseBodyComplete() const {
 462   return parser()->IsResponseBodyComplete();
 463 }
 464
 465 bool WebSocketBasicHandshakeStream::IsConnectionReused() const {
 466   return parser()->IsConnectionReused();
 467 }
 468
 469 void WebSocketBasicHandshakeStream::SetConnectionReused() {
 470   parser()->SetConnectionReused();
 471 }
 472
 473 bool WebSocketBasicHandshakeStream::CanReuseConnection() const {
 474   return false;
 475 }
 476
 477 int64 WebSocketBasicHandshakeStream::GetTotalReceivedBytes() const {
 478   return 0;
 479 }
 480
 481 int64_t WebSocketBasicHandshakeStream::GetTotalSentBytes() const {
 482   return 0;
 483 }
 484
 485 bool WebSocketBasicHandshakeStream::GetLoadTimingInfo(
 486     LoadTimingInfo* load_timing_info) const {
 487   return state_.connection()->GetLoadTimingInfo(IsConnectionReused(),
 488                                                 load_timing_info);
 489 }
 490
 491 void WebSocketBasicHandshakeStream::GetSSLInfo(SSLInfo* ssl_info) {
 492   parser()->GetSSLInfo(ssl_info);
 493 }
 494
 495 void WebSocketBasicHandshakeStream::GetSSLCertRequestInfo(
 496     SSLCertRequestInfo* cert_request_info) {
 497   parser()->GetSSLCertRequestInfo(cert_request_info);
 498 }
 499
 500 void WebSocketBasicHandshakeStream::Drain(HttpNetworkSession* session) {
 501   HttpResponseBodyDrainer* drainer = new HttpResponseBodyDrainer(this);
 502   drainer->Start(session);
 503   // |drainer| will delete itself.
 504 }
 505
 506 void WebSocketBasicHandshakeStream::SetPriority(RequestPriority priority) {
 507   // TODO(ricea): See TODO comment in HttpBasicStream::SetPriority(). If it is
 508   // gone, then copy whatever has happened there over here.
 509 }
 510
 511 UploadProgress WebSocketBasicHandshakeStream::GetUploadProgress() const {
 512   return UploadProgress();
 513 }
 514
 515 HttpStream* WebSocketBasicHandshakeStream::RenewStreamForAuth() {
 516   // Return null because we don't support renewing the stream.
 517   return nullptr;
 518 }
 519
 520 scoped_ptr<WebSocketStream> WebSocketBasicHandshakeStream::Upgrade() {
 521   // The HttpStreamParser object has a pointer to our ClientSocketHandle. Make
 522   // sure it does not touch it again before it is destroyed.
 523   state_.DeleteParser();
 524   WebSocketTransportClientSocketPool::UnlockEndpoint(state_.connection());
 525   scoped_ptr<WebSocketStream> basic_stream(
 526       new WebSocketBasicStream(state_.ReleaseConnection(),
 527                                state_.read_buf(),
 528                                sub_protocol_,
 529                                extensions_));
 530   DCHECK(extension_params_.get());
 531   if (extension_params_->deflate_enabled) {
 532     UMA_HISTOGRAM_ENUMERATION(
 533         "Net.WebSocket.DeflateMode",
 534         extension_params_->deflate_mode,
 535         WebSocketDeflater::NUM_CONTEXT_TAKEOVER_MODE_TYPES);
 536
 537     return scoped_ptr<WebSocketStream>(
 538         new WebSocketDeflateStream(basic_stream.Pass(),
 539                                    extension_params_->deflate_mode,
 540                                    extension_params_->client_window_bits,
 541                                    scoped_ptr<WebSocketDeflatePredictor>(
 542                                        new WebSocketDeflatePredictorImpl)));
 543   } else {
 544     return basic_stream.Pass();
 545   }
 546 }
 547
 548 void WebSocketBasicHandshakeStream::SetWebSocketKeyForTesting(
 549     const std::string& key) {
 550   handshake_challenge_for_testing_.reset(new std::string(key));
 551 }
 552
 553 void WebSocketBasicHandshakeStream::ReadResponseHeadersCallback(
 554     const CompletionCallback& callback,
 555     int result) {
 556   callback.Run(ValidateResponse(result));
 557 }
 558
 559 void WebSocketBasicHandshakeStream::OnFinishOpeningHandshake() {
 560   DCHECK(http_response_info_);
 561   WebSocketDispatchOnFinishOpeningHandshake(connect_delegate_,
 562                                             url_,
 563                                             http_response_info_->headers,
 564                                             http_response_info_->response_time);
 565 }
 566
 567 int WebSocketBasicHandshakeStream::ValidateResponse(int rv) {
 568   DCHECK(http_response_info_);
 569   // Most net errors happen during connection, so they are not seen by this
 570   // method. The histogram for error codes is created in
 571   // Delegate::OnResponseStarted in websocket_stream.cc instead.
 572   if (rv >= 0) {
 573     const HttpResponseHeaders* headers = http_response_info_->headers.get();
 574     const int response_code = headers->response_code();
 575     UMA_HISTOGRAM_SPARSE_SLOWLY("Net.WebSocket.ResponseCode", response_code);
 576     switch (response_code) {
 577       case HTTP_SWITCHING_PROTOCOLS:
 578         OnFinishOpeningHandshake();
 579         return ValidateUpgradeResponse(headers);
 580
 581       // We need to pass these through for authentication to work.
 582       case HTTP_UNAUTHORIZED:
 583       case HTTP_PROXY_AUTHENTICATION_REQUIRED:
 584         return OK;
 585
 586       // Other status codes are potentially risky (see the warnings in the
 587       // WHATWG WebSocket API spec) and so are dropped by default.
 588       default:
 589         // A WebSocket server cannot be using HTTP/0.9, so if we see version
 590         // 0.9, it means the response was garbage.
 591         // Reporting "Unexpected response code: 200" in this case is not
 592         // helpful, so use a different error message.
 593         if (headers->GetHttpVersion() == HttpVersion(0, 9)) {
 594           set_failure_message(
 595               "Error during WebSocket handshake: Invalid status line");
 596         } else {
 597           set_failure_message(base::StringPrintf(
 598               "Error during WebSocket handshake: Unexpected response code: %d",
 599               headers->response_code()));
 600         }
 601         OnFinishOpeningHandshake();
 602         return ERR_INVALID_RESPONSE;
 603     }
 604   } else {
 605     if (rv == ERR_EMPTY_RESPONSE) {
 606       set_failure_message(
 607           "Connection closed before receiving a handshake response");
 608       return rv;
 609     }
 610     set_failure_message(std::string("Error during WebSocket handshake: ") +
 611                         ErrorToString(rv));
 612     OnFinishOpeningHandshake();
 613     // Some error codes (for example ERR_CONNECTION_CLOSED) get changed to OK at
 614     // higher levels. To prevent an unvalidated connection getting erroneously
 615     // upgraded, don't pass through the status code unchanged if it is
 616     // HTTP_SWITCHING_PROTOCOLS.
 617     if (http_response_info_->headers &&
 618         http_response_info_->headers->response_code() ==
 619             HTTP_SWITCHING_PROTOCOLS) {
 620       http_response_info_->headers->ReplaceStatusLine(
 621           kConnectionErrorStatusLine);
 622     }
 623     return rv;
 624   }
 625 }
 626
 627 int WebSocketBasicHandshakeStream::ValidateUpgradeResponse(
 628     const HttpResponseHeaders* headers) {
 629   extension_params_.reset(new WebSocketExtensionParams);
 630   std::string failure_message;
 631   if (ValidateUpgrade(headers, &failure_message) &&
 632       ValidateSecWebSocketAccept(
 633           headers, handshake_challenge_response_, &failure_message) &&
 634       ValidateConnection(headers, &failure_message) &&
 635       ValidateSubProtocol(headers,
 636                           requested_sub_protocols_,
 637                           &sub_protocol_,
 638                           &failure_message) &&
 639       ValidateExtensions(headers,
 640                          &extensions_,
 641                          &failure_message,
 642                          extension_params_.get())) {
 643     return OK;
 644   }
 645   set_failure_message("Error during WebSocket handshake: " + failure_message);
 646   return ERR_INVALID_RESPONSE;
 647 }
 648
 649 void WebSocketBasicHandshakeStream::set_failure_message(
 650     const std::string& failure_message) {
 651   *failure_message_ = failure_message;
 652 }
 653
 654 }  // namespace net