src/net/websockets/websocket_channel.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_channel.h"
   6
   7 #include <limits.h>  // for INT_MAX
   8
   9 #include <algorithm>
  10 #include <deque>
  11
  12 #include "base/basictypes.h"  // for size_t
  13 #include "base/big_endian.h"
  14 #include "base/bind.h"
  15 #include "base/compiler_specific.h"
  16 #include "base/memory/ref_counted.h"
  17 #include "base/memory/weak_ptr.h"
  18 #include "base/message_loop/message_loop.h"
  19 #include "base/metrics/histogram.h"
  20 #include "base/numerics/safe_conversions.h"
  21 #include "base/stl_util.h"
  22 #include "base/strings/stringprintf.h"
  23 #include "base/time/time.h"
  24 #include "net/base/io_buffer.h"
  25 #include "net/base/net_log.h"
  26 #include "net/http/http_request_headers.h"
  27 #include "net/http/http_response_headers.h"
  28 #include "net/http/http_util.h"
  29 #include "net/websockets/websocket_errors.h"
  30 #include "net/websockets/websocket_event_interface.h"
  31 #include "net/websockets/websocket_frame.h"
  32 #include "net/websockets/websocket_handshake_request_info.h"
  33 #include "net/websockets/websocket_handshake_response_info.h"
  34 #include "net/websockets/websocket_mux.h"
  35 #include "net/websockets/websocket_stream.h"
  36 #include "url/origin.h"
  37
  38 namespace net {
  39
  40 namespace {
  41
  42 using base::StreamingUtf8Validator;
  43
  44 const int kDefaultSendQuotaLowWaterMark = 1 << 16;
  45 const int kDefaultSendQuotaHighWaterMark = 1 << 17;
  46 const size_t kWebSocketCloseCodeLength = 2;
  47 // This timeout is based on TCPMaximumSegmentLifetime * 2 from
  48 // MainThreadWebSocketChannel.cpp in Blink.
  49 const int kClosingHandshakeTimeoutSeconds = 2 * 2 * 60;
  50
  51 typedef WebSocketEventInterface::ChannelState ChannelState;
  52 const ChannelState CHANNEL_ALIVE = WebSocketEventInterface::CHANNEL_ALIVE;
  53 const ChannelState CHANNEL_DELETED = WebSocketEventInterface::CHANNEL_DELETED;
  54
  55 // Maximum close reason length = max control frame payload -
  56 //                               status code length
  57 //                             = 125 - 2
  58 const size_t kMaximumCloseReasonLength = 125 - kWebSocketCloseCodeLength;
  59
  60 // Check a close status code for strict compliance with RFC6455. This is only
  61 // used for close codes received from a renderer that we are intending to send
  62 // out over the network. See ParseClose() for the restrictions on incoming close
  63 // codes. The |code| parameter is type int for convenience of implementation;
  64 // the real type is uint16. Code 1005 is treated specially; it cannot be set
  65 // explicitly by Javascript but the renderer uses it to indicate we should send
  66 // a Close frame with no payload.
  67 bool IsStrictlyValidCloseStatusCode(int code) {
  68   static const int kInvalidRanges[] = {
  69       // [BAD, OK)
  70       0,    1000,   // 1000 is the first valid code
  71       1006, 1007,   // 1006 MUST NOT be set.
  72       1014, 3000,   // 1014 unassigned; 1015 up to 2999 are reserved.
  73       5000, 65536,  // Codes above 5000 are invalid.
  74   };
  75   const int* const kInvalidRangesEnd =
  76       kInvalidRanges + arraysize(kInvalidRanges);
  77
  78   DCHECK_GE(code, 0);
  79   DCHECK_LT(code, 65536);
  80   const int* upper = std::upper_bound(kInvalidRanges, kInvalidRangesEnd, code);
  81   DCHECK_NE(kInvalidRangesEnd, upper);
  82   DCHECK_GT(upper, kInvalidRanges);
  83   DCHECK_GT(*upper, code);
  84   DCHECK_LE(*(upper - 1), code);
  85   return ((upper - kInvalidRanges) % 2) == 0;
  86 }
  87
  88 // This function avoids a bunch of boilerplate code.
  89 void AllowUnused(ChannelState ALLOW_UNUSED unused) {}
  90
  91 // Sets |name| to the name of the frame type for the given |opcode|. Note that
  92 // for all of Text, Binary and Continuation opcode, this method returns
  93 // "Data frame".
  94 void GetFrameTypeForOpcode(WebSocketFrameHeader::OpCode opcode,
  95                            std::string* name) {
  96   switch (opcode) {
  97     case WebSocketFrameHeader::kOpCodeText:    // fall-thru
  98     case WebSocketFrameHeader::kOpCodeBinary:  // fall-thru
  99     case WebSocketFrameHeader::kOpCodeContinuation:
 100       *name = "Data frame";
 101       break;
 102
 103     case WebSocketFrameHeader::kOpCodePing:
 104       *name = "Ping";
 105       break;
 106
 107     case WebSocketFrameHeader::kOpCodePong:
 108       *name = "Pong";
 109       break;
 110
 111     case WebSocketFrameHeader::kOpCodeClose:
 112       *name = "Close";
 113       break;
 114
 115     default:
 116       *name = "Unknown frame type";
 117       break;
 118   }
 119
 120   return;
 121 }
 122
 123 }  // namespace
 124
 125 // A class to encapsulate a set of frames and information about the size of
 126 // those frames.
 127 class WebSocketChannel::SendBuffer {
 128  public:
 129   SendBuffer() : total_bytes_(0) {}
 130
 131   // Add a WebSocketFrame to the buffer and increase total_bytes_.
 132   void AddFrame(scoped_ptr<WebSocketFrame> chunk);
 133
 134   // Return a pointer to the frames_ for write purposes.
 135   ScopedVector<WebSocketFrame>* frames() { return &frames_; }
 136
 137  private:
 138   // The frames_ that will be sent in the next call to WriteFrames().
 139   ScopedVector<WebSocketFrame> frames_;
 140
 141   // The total size of the payload data in |frames_|. This will be used to
 142   // measure the throughput of the link.
 143   // TODO(ricea): Measure the throughput of the link.
 144   size_t total_bytes_;
 145 };
 146
 147 void WebSocketChannel::SendBuffer::AddFrame(scoped_ptr<WebSocketFrame> frame) {
 148   total_bytes_ += frame->header.payload_length;
 149   frames_.push_back(frame.release());
 150 }
 151
 152 // Implementation of WebSocketStream::ConnectDelegate that simply forwards the
 153 // calls on to the WebSocketChannel that created it.
 154 class WebSocketChannel::ConnectDelegate
 155     : public WebSocketStream::ConnectDelegate {
 156  public:
 157   explicit ConnectDelegate(WebSocketChannel* creator) : creator_(creator) {}
 158
 159   virtual void OnSuccess(scoped_ptr<WebSocketStream> stream) OVERRIDE {
 160     creator_->OnConnectSuccess(stream.Pass());
 161     // |this| may have been deleted.
 162   }
 163
 164   virtual void OnFailure(const std::string& message) OVERRIDE {
 165     creator_->OnConnectFailure(message);
 166     // |this| has been deleted.
 167   }
 168
 169   virtual void OnStartOpeningHandshake(
 170       scoped_ptr<WebSocketHandshakeRequestInfo> request) OVERRIDE {
 171     creator_->OnStartOpeningHandshake(request.Pass());
 172   }
 173
 174   virtual void OnFinishOpeningHandshake(
 175       scoped_ptr<WebSocketHandshakeResponseInfo> response) OVERRIDE {
 176     creator_->OnFinishOpeningHandshake(response.Pass());
 177   }
 178
 179  private:
 180   // A pointer to the WebSocketChannel that created this object. There is no
 181   // danger of this pointer being stale, because deleting the WebSocketChannel
 182   // cancels the connect process, deleting this object and preventing its
 183   // callbacks from being called.
 184   WebSocketChannel* const creator_;
 185
 186   DISALLOW_COPY_AND_ASSIGN(ConnectDelegate);
 187 };
 188
 189 class WebSocketChannel::HandshakeNotificationSender
 190     : public base::SupportsWeakPtr<HandshakeNotificationSender> {
 191  public:
 192   explicit HandshakeNotificationSender(WebSocketChannel* channel);
 193   ~HandshakeNotificationSender();
 194
 195   static void Send(base::WeakPtr<HandshakeNotificationSender> sender);
 196
 197   ChannelState SendImmediately(WebSocketEventInterface* event_interface);
 198
 199   const WebSocketHandshakeRequestInfo* handshake_request_info() const {
 200     return handshake_request_info_.get();
 201   }
 202
 203   void set_handshake_request_info(
 204       scoped_ptr<WebSocketHandshakeRequestInfo> request_info) {
 205     handshake_request_info_ = request_info.Pass();
 206   }
 207
 208   const WebSocketHandshakeResponseInfo* handshake_response_info() const {
 209     return handshake_response_info_.get();
 210   }
 211
 212   void set_handshake_response_info(
 213       scoped_ptr<WebSocketHandshakeResponseInfo> response_info) {
 214     handshake_response_info_ = response_info.Pass();
 215   }
 216
 217  private:
 218   WebSocketChannel* owner_;
 219   scoped_ptr<WebSocketHandshakeRequestInfo> handshake_request_info_;
 220   scoped_ptr<WebSocketHandshakeResponseInfo> handshake_response_info_;
 221 };
 222
 223 WebSocketChannel::HandshakeNotificationSender::HandshakeNotificationSender(
 224     WebSocketChannel* channel)
 225     : owner_(channel) {}
 226
 227 WebSocketChannel::HandshakeNotificationSender::~HandshakeNotificationSender() {}
 228
 229 void WebSocketChannel::HandshakeNotificationSender::Send(
 230     base::WeakPtr<HandshakeNotificationSender> sender) {
 231   // Do nothing if |sender| is already destructed.
 232   if (sender) {
 233     WebSocketChannel* channel = sender->owner_;
 234     AllowUnused(sender->SendImmediately(channel->event_interface_.get()));
 235   }
 236 }
 237
 238 ChannelState WebSocketChannel::HandshakeNotificationSender::SendImmediately(
 239     WebSocketEventInterface* event_interface) {
 240
 241   if (handshake_request_info_.get()) {
 242     if (CHANNEL_DELETED == event_interface->OnStartOpeningHandshake(
 243                                handshake_request_info_.Pass()))
 244       return CHANNEL_DELETED;
 245   }
 246
 247   if (handshake_response_info_.get()) {
 248     if (CHANNEL_DELETED == event_interface->OnFinishOpeningHandshake(
 249                                handshake_response_info_.Pass()))
 250       return CHANNEL_DELETED;
 251
 252     // TODO(yhirano): We can release |this| to save memory because
 253     // there will be no more opening handshake notification.
 254   }
 255
 256   return CHANNEL_ALIVE;
 257 }
 258
 259 WebSocketChannel::PendingReceivedFrame::PendingReceivedFrame(
 260     bool final,
 261     WebSocketFrameHeader::OpCode opcode,
 262     const scoped_refptr<IOBuffer>& data,
 263     size_t offset,
 264     size_t size)
 265     : final_(final),
 266       opcode_(opcode),
 267       data_(data),
 268       offset_(offset),
 269       size_(size) {}
 270
 271 WebSocketChannel::PendingReceivedFrame::~PendingReceivedFrame() {}
 272
 273 void WebSocketChannel::PendingReceivedFrame::ResetOpcode() {
 274   DCHECK(WebSocketFrameHeader::IsKnownDataOpCode(opcode_));
 275   opcode_ = WebSocketFrameHeader::kOpCodeContinuation;
 276 }
 277
 278 void WebSocketChannel::PendingReceivedFrame::DidConsume(size_t bytes) {
 279   DCHECK_LE(offset_, size_);
 280   DCHECK_LE(bytes, size_ - offset_);
 281   offset_ += bytes;
 282 }
 283
 284 WebSocketChannel::WebSocketChannel(
 285     scoped_ptr<WebSocketEventInterface> event_interface,
 286     URLRequestContext* url_request_context)
 287     : event_interface_(event_interface.Pass()),
 288       url_request_context_(url_request_context),
 289       send_quota_low_water_mark_(kDefaultSendQuotaLowWaterMark),
 290       send_quota_high_water_mark_(kDefaultSendQuotaHighWaterMark),
 291       current_send_quota_(0),
 292       current_receive_quota_(0),
 293       timeout_(base::TimeDelta::FromSeconds(kClosingHandshakeTimeoutSeconds)),
 294       received_close_code_(0),
 295       state_(FRESHLY_CONSTRUCTED),
 296       notification_sender_(new HandshakeNotificationSender(this)),
 297       sending_text_message_(false),
 298       receiving_text_message_(false),
 299       expecting_to_handle_continuation_(false),
 300       initial_frame_forwarded_(false) {}
 301
 302 WebSocketChannel::~WebSocketChannel() {
 303   // The stream may hold a pointer to read_frames_, and so it needs to be
 304   // destroyed first.
 305   stream_.reset();
 306   // The timer may have a callback pointing back to us, so stop it just in case
 307   // someone decides to run the event loop from their destructor.
 308   timer_.Stop();
 309 }
 310
 311 void WebSocketChannel::SendAddChannelRequest(
 312     const GURL& socket_url,
 313     const std::vector<std::string>& requested_subprotocols,
 314     const url::Origin& origin) {
 315   // Delegate to the tested version.
 316   SendAddChannelRequestWithSuppliedCreator(
 317       socket_url,
 318       requested_subprotocols,
 319       origin,
 320       base::Bind(&WebSocketStream::CreateAndConnectStream));
 321 }
 322
 323 void WebSocketChannel::SetState(State new_state) {
 324   DCHECK_NE(state_, new_state);
 325
 326   if (new_state == CONNECTED)
 327     established_on_ = base::TimeTicks::Now();
 328   if (state_ == CONNECTED && !established_on_.is_null()) {
 329     UMA_HISTOGRAM_LONG_TIMES(
 330         "Net.WebSocket.Duration", base::TimeTicks::Now() - established_on_);
 331   }
 332
 333   state_ = new_state;
 334 }
 335
 336 bool WebSocketChannel::InClosingState() const {
 337   // The state RECV_CLOSED is not supported here, because it is only used in one
 338   // code path and should not leak into the code in general.
 339   DCHECK_NE(RECV_CLOSED, state_)
 340       << "InClosingState called with state_ == RECV_CLOSED";
 341   return state_ == SEND_CLOSED || state_ == CLOSE_WAIT || state_ == CLOSED;
 342 }
 343
 344 void WebSocketChannel::SendFrame(bool fin,
 345                                  WebSocketFrameHeader::OpCode op_code,
 346                                  const std::vector<char>& data) {
 347   if (data.size() > INT_MAX) {
 348     NOTREACHED() << "Frame size sanity check failed";
 349     return;
 350   }
 351   if (stream_ == NULL) {
 352     LOG(DFATAL) << "Got SendFrame without a connection established; "
 353                 << "misbehaving renderer? fin=" << fin << " op_code=" << op_code
 354                 << " data.size()=" << data.size();
 355     return;
 356   }
 357   if (InClosingState()) {
 358     DVLOG(1) << "SendFrame called in state " << state_
 359              << ". This may be a bug, or a harmless race.";
 360     return;
 361   }
 362   if (state_ != CONNECTED) {
 363     NOTREACHED() << "SendFrame() called in state " << state_;
 364     return;
 365   }
 366   if (data.size() > base::checked_cast<size_t>(current_send_quota_)) {
 367     // TODO(ricea): Kill renderer.
 368     AllowUnused(
 369         FailChannel("Send quota exceeded", kWebSocketErrorGoingAway, ""));
 370     // |this| has been deleted.
 371     return;
 372   }
 373   if (!WebSocketFrameHeader::IsKnownDataOpCode(op_code)) {
 374     LOG(DFATAL) << "Got SendFrame with bogus op_code " << op_code
 375                 << "; misbehaving renderer? fin=" << fin
 376                 << " data.size()=" << data.size();
 377     return;
 378   }
 379   if (op_code == WebSocketFrameHeader::kOpCodeText ||
 380       (op_code == WebSocketFrameHeader::kOpCodeContinuation &&
 381        sending_text_message_)) {
 382     StreamingUtf8Validator::State state =
 383         outgoing_utf8_validator_.AddBytes(vector_as_array(&data), data.size());
 384     if (state == StreamingUtf8Validator::INVALID ||
 385         (state == StreamingUtf8Validator::VALID_MIDPOINT && fin)) {
 386       // TODO(ricea): Kill renderer.
 387       AllowUnused(
 388           FailChannel("Browser sent a text frame containing invalid UTF-8",
 389                       kWebSocketErrorGoingAway,
 390                       ""));
 391       // |this| has been deleted.
 392       return;
 393     }
 394     sending_text_message_ = !fin;
 395     DCHECK(!fin || state == StreamingUtf8Validator::VALID_ENDPOINT);
 396   }
 397   current_send_quota_ -= data.size();
 398   // TODO(ricea): If current_send_quota_ has dropped below
 399   // send_quota_low_water_mark_, it might be good to increase the "low
 400   // water mark" and "high water mark", but only if the link to the WebSocket
 401   // server is not saturated.
 402   scoped_refptr<IOBuffer> buffer(new IOBuffer(data.size()));
 403   std::copy(data.begin(), data.end(), buffer->data());
 404   AllowUnused(SendFrameFromIOBuffer(fin, op_code, buffer, data.size()));
 405   // |this| may have been deleted.
 406 }
 407
 408 void WebSocketChannel::SendFlowControl(int64 quota) {
 409   DCHECK(state_ == CONNECTING || state_ == CONNECTED || state_ == SEND_CLOSED ||
 410          state_ == CLOSE_WAIT);
 411   // TODO(ricea): Kill the renderer if it tries to send us a negative quota
 412   // value or > INT_MAX.
 413   DCHECK_GE(quota, 0);
 414   DCHECK_LE(quota, INT_MAX);
 415   if (!pending_received_frames_.empty()) {
 416     DCHECK_EQ(0, current_receive_quota_);
 417   }
 418   while (!pending_received_frames_.empty() && quota > 0) {
 419     PendingReceivedFrame& front = pending_received_frames_.front();
 420     const size_t data_size = front.size() - front.offset();
 421     const size_t bytes_to_send =
 422         std::min(base::checked_cast<size_t>(quota), data_size);
 423     const bool final = front.final() && data_size == bytes_to_send;
 424     const char* data = front.data() ?
 425         front.data()->data() + front.offset() : NULL;
 426     DCHECK(!bytes_to_send || data) << "Non empty data should not be null.";
 427     const std::vector<char> data_vector(data, data + bytes_to_send);
 428     DVLOG(3) << "Sending frame previously split due to quota to the "
 429              << "renderer: quota=" << quota << " data_size=" << data_size
 430              << " bytes_to_send=" << bytes_to_send;
 431     if (event_interface_->OnDataFrame(final, front.opcode(), data_vector) ==
 432         CHANNEL_DELETED)
 433       return;
 434     if (bytes_to_send < data_size) {
 435       front.DidConsume(bytes_to_send);
 436       front.ResetOpcode();
 437       return;
 438     }
 439     const int64 signed_bytes_to_send = base::checked_cast<int64>(bytes_to_send);
 440     DCHECK_GE(quota, signed_bytes_to_send);
 441     quota -= signed_bytes_to_send;
 442
 443     pending_received_frames_.pop();
 444   }
 445   // If current_receive_quota_ == 0 then there is no pending ReadFrames()
 446   // operation.
 447   const bool start_read =
 448       current_receive_quota_ == 0 && quota > 0 &&
 449       (state_ == CONNECTED || state_ == SEND_CLOSED || state_ == CLOSE_WAIT);
 450   current_receive_quota_ += base::checked_cast<int>(quota);
 451   if (start_read)
 452     AllowUnused(ReadFrames());
 453   // |this| may have been deleted.
 454 }
 455
 456 void WebSocketChannel::StartClosingHandshake(uint16 code,
 457                                              const std::string& reason) {
 458   if (InClosingState()) {
 459     DVLOG(1) << "StartClosingHandshake called in state " << state_
 460              << ". This may be a bug, or a harmless race.";
 461     return;
 462   }
 463   if (state_ == CONNECTING) {
 464     // Abort the in-progress handshake and drop the connection immediately.
 465     stream_request_.reset();
 466     SetState(CLOSED);
 467     AllowUnused(DoDropChannel(false, kWebSocketErrorAbnormalClosure, ""));
 468     return;
 469   }
 470   if (state_ != CONNECTED) {
 471     NOTREACHED() << "StartClosingHandshake() called in state " << state_;
 472     return;
 473   }
 474   // Javascript actually only permits 1000 and 3000-4999, but the implementation
 475   // itself may produce different codes. The length of |reason| is also checked
 476   // by Javascript.
 477   if (!IsStrictlyValidCloseStatusCode(code) ||
 478       reason.size() > kMaximumCloseReasonLength) {
 479     // "InternalServerError" is actually used for errors from any endpoint, per
 480     // errata 3227 to RFC6455. If the renderer is sending us an invalid code or
 481     // reason it must be malfunctioning in some way, and based on that we
 482     // interpret this as an internal error.
 483     if (SendClose(kWebSocketErrorInternalServerError, "") != CHANNEL_DELETED) {
 484       DCHECK_EQ(CONNECTED, state_);
 485       SetState(SEND_CLOSED);
 486     }
 487     return;
 488   }
 489   if (SendClose(
 490           code,
 491           StreamingUtf8Validator::Validate(reason) ? reason : std::string()) ==
 492       CHANNEL_DELETED)
 493     return;
 494   DCHECK_EQ(CONNECTED, state_);
 495   SetState(SEND_CLOSED);
 496 }
 497
 498 void WebSocketChannel::SendAddChannelRequestForTesting(
 499     const GURL& socket_url,
 500     const std::vector<std::string>& requested_subprotocols,
 501     const url::Origin& origin,
 502     const WebSocketStreamCreator& creator) {
 503   SendAddChannelRequestWithSuppliedCreator(
 504       socket_url, requested_subprotocols, origin, creator);
 505 }
 506
 507 void WebSocketChannel::SetClosingHandshakeTimeoutForTesting(
 508     base::TimeDelta delay) {
 509   timeout_ = delay;
 510 }
 511
 512 void WebSocketChannel::SendAddChannelRequestWithSuppliedCreator(
 513     const GURL& socket_url,
 514     const std::vector<std::string>& requested_subprotocols,
 515     const url::Origin& origin,
 516     const WebSocketStreamCreator& creator) {
 517   DCHECK_EQ(FRESHLY_CONSTRUCTED, state_);
 518   if (!socket_url.SchemeIsWSOrWSS()) {
 519     // TODO(ricea): Kill the renderer (this error should have been caught by
 520     // Javascript).
 521     AllowUnused(event_interface_->OnAddChannelResponse(true, "", ""));
 522     // |this| is deleted here.
 523     return;
 524   }
 525   socket_url_ = socket_url;
 526   scoped_ptr<WebSocketStream::ConnectDelegate> connect_delegate(
 527       new ConnectDelegate(this));
 528   stream_request_ = creator.Run(socket_url_,
 529                                 requested_subprotocols,
 530                                 origin,
 531                                 url_request_context_,
 532                                 BoundNetLog(),
 533                                 connect_delegate.Pass());
 534   SetState(CONNECTING);
 535 }
 536
 537 void WebSocketChannel::OnConnectSuccess(scoped_ptr<WebSocketStream> stream) {
 538   DCHECK(stream);
 539   DCHECK_EQ(CONNECTING, state_);
 540
 541   stream_ = stream.Pass();
 542
 543   SetState(CONNECTED);
 544
 545   if (event_interface_->OnAddChannelResponse(
 546           false, stream_->GetSubProtocol(), stream_->GetExtensions()) ==
 547       CHANNEL_DELETED)
 548     return;
 549
 550   // TODO(ricea): Get flow control information from the WebSocketStream once we
 551   // have a multiplexing WebSocketStream.
 552   current_send_quota_ = send_quota_high_water_mark_;
 553   if (event_interface_->OnFlowControl(send_quota_high_water_mark_) ==
 554       CHANNEL_DELETED)
 555     return;
 556
 557   // |stream_request_| is not used once the connection has succeeded.
 558   stream_request_.reset();
 559
 560   AllowUnused(ReadFrames());
 561   // |this| may have been deleted.
 562 }
 563
 564 void WebSocketChannel::OnConnectFailure(const std::string& message) {
 565   DCHECK_EQ(CONNECTING, state_);
 566
 567   SetState(CLOSED);
 568   stream_request_.reset();
 569
 570   if (CHANNEL_DELETED ==
 571       notification_sender_->SendImmediately(event_interface_.get())) {
 572     // |this| has been deleted.
 573     return;
 574   }
 575   AllowUnused(event_interface_->OnFailChannel(message));
 576   // |this| has been deleted.
 577 }
 578
 579 void WebSocketChannel::OnStartOpeningHandshake(
 580     scoped_ptr<WebSocketHandshakeRequestInfo> request) {
 581   DCHECK(!notification_sender_->handshake_request_info());
 582
 583   // Because it is hard to handle an IPC error synchronously is difficult,
 584   // we asynchronously notify the information.
 585   notification_sender_->set_handshake_request_info(request.Pass());
 586   ScheduleOpeningHandshakeNotification();
 587 }
 588
 589 void WebSocketChannel::OnFinishOpeningHandshake(
 590     scoped_ptr<WebSocketHandshakeResponseInfo> response) {
 591   DCHECK(!notification_sender_->handshake_response_info());
 592
 593   // Because it is hard to handle an IPC error synchronously is difficult,
 594   // we asynchronously notify the information.
 595   notification_sender_->set_handshake_response_info(response.Pass());
 596   ScheduleOpeningHandshakeNotification();
 597 }
 598
 599 void WebSocketChannel::ScheduleOpeningHandshakeNotification() {
 600   base::MessageLoop::current()->PostTask(
 601       FROM_HERE,
 602       base::Bind(HandshakeNotificationSender::Send,
 603                  notification_sender_->AsWeakPtr()));
 604 }
 605
 606 ChannelState WebSocketChannel::WriteFrames() {
 607   int result = OK;
 608   do {
 609     // This use of base::Unretained is safe because this object owns the
 610     // WebSocketStream and destroying it cancels all callbacks.
 611     result = stream_->WriteFrames(
 612         data_being_sent_->frames(),
 613         base::Bind(base::IgnoreResult(&WebSocketChannel::OnWriteDone),
 614                    base::Unretained(this),
 615                    false));
 616     if (result != ERR_IO_PENDING) {
 617       if (OnWriteDone(true, result) == CHANNEL_DELETED)
 618         return CHANNEL_DELETED;
 619       // OnWriteDone() returns CHANNEL_DELETED on error. Here |state_| is
 620       // guaranteed to be the same as before OnWriteDone() call.
 621     }
 622   } while (result == OK && data_being_sent_);
 623   return CHANNEL_ALIVE;
 624 }
 625
 626 ChannelState WebSocketChannel::OnWriteDone(bool synchronous, int result) {
 627   DCHECK_NE(FRESHLY_CONSTRUCTED, state_);
 628   DCHECK_NE(CONNECTING, state_);
 629   DCHECK_NE(ERR_IO_PENDING, result);
 630   DCHECK(data_being_sent_);
 631   switch (result) {
 632     case OK:
 633       if (data_to_send_next_) {
 634         data_being_sent_ = data_to_send_next_.Pass();
 635         if (!synchronous)
 636           return WriteFrames();
 637       } else {
 638         data_being_sent_.reset();
 639         if (current_send_quota_ < send_quota_low_water_mark_) {
 640           // TODO(ricea): Increase low_water_mark and high_water_mark if
 641           // throughput is high, reduce them if throughput is low.  Low water
 642           // mark needs to be >= the bandwidth delay product *of the IPC
 643           // channel*. Because factors like context-switch time, thread wake-up
 644           // time, and bus speed come into play it is complex and probably needs
 645           // to be determined empirically.
 646           DCHECK_LE(send_quota_low_water_mark_, send_quota_high_water_mark_);
 647           // TODO(ricea): Truncate quota by the quota specified by the remote
 648           // server, if the protocol in use supports quota.
 649           int fresh_quota = send_quota_high_water_mark_ - current_send_quota_;
 650           current_send_quota_ += fresh_quota;
 651           return event_interface_->OnFlowControl(fresh_quota);
 652         }
 653       }
 654       return CHANNEL_ALIVE;
 655
 656     // If a recoverable error condition existed, it would go here.
 657
 658     default:
 659       DCHECK_LT(result, 0)
 660           << "WriteFrames() should only return OK or ERR_ codes";
 661
 662       stream_->Close();
 663       SetState(CLOSED);
 664       return DoDropChannel(false, kWebSocketErrorAbnormalClosure, "");
 665   }
 666 }
 667
 668 ChannelState WebSocketChannel::ReadFrames() {
 669   int result = OK;
 670   while (result == OK && current_receive_quota_ > 0) {
 671     // This use of base::Unretained is safe because this object owns the
 672     // WebSocketStream, and any pending reads will be cancelled when it is
 673     // destroyed.
 674     result = stream_->ReadFrames(
 675         &read_frames_,
 676         base::Bind(base::IgnoreResult(&WebSocketChannel::OnReadDone),
 677                    base::Unretained(this),
 678                    false));
 679     if (result != ERR_IO_PENDING) {
 680       if (OnReadDone(true, result) == CHANNEL_DELETED)
 681         return CHANNEL_DELETED;
 682     }
 683     DCHECK_NE(CLOSED, state_);
 684   }
 685   return CHANNEL_ALIVE;
 686 }
 687
 688 ChannelState WebSocketChannel::OnReadDone(bool synchronous, int result) {
 689   DCHECK_NE(FRESHLY_CONSTRUCTED, state_);
 690   DCHECK_NE(CONNECTING, state_);
 691   DCHECK_NE(ERR_IO_PENDING, result);
 692   switch (result) {
 693     case OK:
 694       // ReadFrames() must use ERR_CONNECTION_CLOSED for a closed connection
 695       // with no data read, not an empty response.
 696       DCHECK(!read_frames_.empty())
 697           << "ReadFrames() returned OK, but nothing was read.";
 698       for (size_t i = 0; i < read_frames_.size(); ++i) {
 699         scoped_ptr<WebSocketFrame> frame(read_frames_[i]);
 700         read_frames_[i] = NULL;
 701         if (HandleFrame(frame.Pass()) == CHANNEL_DELETED)
 702           return CHANNEL_DELETED;
 703       }
 704       read_frames_.clear();
 705       // There should always be a call to ReadFrames pending.
 706       // TODO(ricea): Unless we are out of quota.
 707       DCHECK_NE(CLOSED, state_);
 708       if (!synchronous)
 709         return ReadFrames();
 710       return CHANNEL_ALIVE;
 711
 712     case ERR_WS_PROTOCOL_ERROR:
 713       // This could be kWebSocketErrorProtocolError (specifically, non-minimal
 714       // encoding of payload length) or kWebSocketErrorMessageTooBig, or an
 715       // extension-specific error.
 716       return FailChannel("Invalid frame header",
 717                          kWebSocketErrorProtocolError,
 718                          "WebSocket Protocol Error");
 719
 720     default:
 721       DCHECK_LT(result, 0)
 722           << "ReadFrames() should only return OK or ERR_ codes";
 723
 724       stream_->Close();
 725       SetState(CLOSED);
 726
 727       uint16 code = kWebSocketErrorAbnormalClosure;
 728       std::string reason = "";
 729       bool was_clean = false;
 730       if (received_close_code_ != 0) {
 731         code = received_close_code_;
 732         reason = received_close_reason_;
 733         was_clean = (result == ERR_CONNECTION_CLOSED);
 734       }
 735
 736       return DoDropChannel(was_clean, code, reason);
 737   }
 738 }
 739
 740 ChannelState WebSocketChannel::HandleFrame(scoped_ptr<WebSocketFrame> frame) {
 741   if (frame->header.masked) {
 742     // RFC6455 Section 5.1 "A client MUST close a connection if it detects a
 743     // masked frame."
 744     return FailChannel(
 745         "A server must not mask any frames that it sends to the "
 746         "client.",
 747         kWebSocketErrorProtocolError,
 748         "Masked frame from server");
 749   }
 750   const WebSocketFrameHeader::OpCode opcode = frame->header.opcode;
 751   DCHECK(!WebSocketFrameHeader::IsKnownControlOpCode(opcode) ||
 752          frame->header.final);
 753   if (frame->header.reserved1 || frame->header.reserved2 ||
 754       frame->header.reserved3) {
 755     return FailChannel(base::StringPrintf(
 756                            "One or more reserved bits are on: reserved1 = %d, "
 757                            "reserved2 = %d, reserved3 = %d",
 758                            static_cast<int>(frame->header.reserved1),
 759                            static_cast<int>(frame->header.reserved2),
 760                            static_cast<int>(frame->header.reserved3)),
 761                        kWebSocketErrorProtocolError,
 762                        "Invalid reserved bit");
 763   }
 764
 765   // Respond to the frame appropriately to its type.
 766   return HandleFrameByState(
 767       opcode, frame->header.final, frame->data, frame->header.payload_length);
 768 }
 769
 770 ChannelState WebSocketChannel::HandleFrameByState(
 771     const WebSocketFrameHeader::OpCode opcode,
 772     bool final,
 773     const scoped_refptr<IOBuffer>& data_buffer,
 774     size_t size) {
 775   DCHECK_NE(RECV_CLOSED, state_)
 776       << "HandleFrame() does not support being called re-entrantly from within "
 777          "SendClose()";
 778   DCHECK_NE(CLOSED, state_);
 779   if (state_ == CLOSE_WAIT) {
 780     std::string frame_name;
 781     GetFrameTypeForOpcode(opcode, &frame_name);
 782
 783     // FailChannel() won't send another Close frame.
 784     return FailChannel(
 785         frame_name + " received after close", kWebSocketErrorProtocolError, "");
 786   }
 787   switch (opcode) {
 788     case WebSocketFrameHeader::kOpCodeText:  // fall-thru
 789     case WebSocketFrameHeader::kOpCodeBinary:
 790     case WebSocketFrameHeader::kOpCodeContinuation:
 791       return HandleDataFrame(opcode, final, data_buffer, size);
 792
 793     case WebSocketFrameHeader::kOpCodePing:
 794       DVLOG(1) << "Got Ping of size " << size;
 795       if (state_ == CONNECTED)
 796         return SendFrameFromIOBuffer(
 797             true, WebSocketFrameHeader::kOpCodePong, data_buffer, size);
 798       DVLOG(3) << "Ignored ping in state " << state_;
 799       return CHANNEL_ALIVE;
 800
 801     case WebSocketFrameHeader::kOpCodePong:
 802       DVLOG(1) << "Got Pong of size " << size;
 803       // There is no need to do anything with pong messages.
 804       return CHANNEL_ALIVE;
 805
 806     case WebSocketFrameHeader::kOpCodeClose: {
 807       // TODO(ricea): If there is a message which is queued for transmission to
 808       // the renderer, then the renderer should not receive an
 809       // OnClosingHandshake or OnDropChannel IPC until the queued message has
 810       // been completedly transmitted.
 811       uint16 code = kWebSocketNormalClosure;
 812       std::string reason;
 813       std::string message;
 814       if (!ParseClose(data_buffer, size, &code, &reason, &message)) {
 815         return FailChannel(message, code, reason);
 816       }
 817       // TODO(ricea): Find a way to safely log the message from the close
 818       // message (escape control codes and so on).
 819       DVLOG(1) << "Got Close with code " << code;
 820       switch (state_) {
 821         case CONNECTED:
 822           SetState(RECV_CLOSED);
 823           if (SendClose(code, reason) == CHANNEL_DELETED)
 824             return CHANNEL_DELETED;
 825           DCHECK_EQ(RECV_CLOSED, state_);
 826           SetState(CLOSE_WAIT);
 827
 828           if (event_interface_->OnClosingHandshake() == CHANNEL_DELETED)
 829             return CHANNEL_DELETED;
 830           received_close_code_ = code;
 831           received_close_reason_ = reason;
 832           break;
 833
 834         case SEND_CLOSED:
 835           SetState(CLOSE_WAIT);
 836           // From RFC6455 section 7.1.5: "Each endpoint
 837           // will see the status code sent by the other end as _The WebSocket
 838           // Connection Close Code_."
 839           received_close_code_ = code;
 840           received_close_reason_ = reason;
 841           break;
 842
 843         default:
 844           LOG(DFATAL) << "Got Close in unexpected state " << state_;
 845           break;
 846       }
 847       return CHANNEL_ALIVE;
 848     }
 849
 850     default:
 851       return FailChannel(
 852           base::StringPrintf("Unrecognized frame opcode: %d", opcode),
 853           kWebSocketErrorProtocolError,
 854           "Unknown opcode");
 855   }
 856 }
 857
 858 ChannelState WebSocketChannel::HandleDataFrame(
 859     WebSocketFrameHeader::OpCode opcode,
 860     bool final,
 861     const scoped_refptr<IOBuffer>& data_buffer,
 862     size_t size) {
 863   if (state_ != CONNECTED) {
 864     DVLOG(3) << "Ignored data packet received in state " << state_;
 865     return CHANNEL_ALIVE;
 866   }
 867   DCHECK(opcode == WebSocketFrameHeader::kOpCodeContinuation ||
 868          opcode == WebSocketFrameHeader::kOpCodeText ||
 869          opcode == WebSocketFrameHeader::kOpCodeBinary);
 870   const bool got_continuation =
 871       (opcode == WebSocketFrameHeader::kOpCodeContinuation);
 872   if (got_continuation != expecting_to_handle_continuation_) {
 873     const std::string console_log = got_continuation
 874         ? "Received unexpected continuation frame."
 875         : "Received start of new message but previous message is unfinished.";
 876     const std::string reason = got_continuation
 877         ? "Unexpected continuation"
 878         : "Previous data frame unfinished";
 879     return FailChannel(console_log, kWebSocketErrorProtocolError, reason);
 880   }
 881   expecting_to_handle_continuation_ = !final;
 882   WebSocketFrameHeader::OpCode opcode_to_send = opcode;
 883   if (!initial_frame_forwarded_ &&
 884       opcode == WebSocketFrameHeader::kOpCodeContinuation) {
 885     opcode_to_send = receiving_text_message_
 886                          ? WebSocketFrameHeader::kOpCodeText
 887                          : WebSocketFrameHeader::kOpCodeBinary;
 888   }
 889   if (opcode == WebSocketFrameHeader::kOpCodeText ||
 890       (opcode == WebSocketFrameHeader::kOpCodeContinuation &&
 891        receiving_text_message_)) {
 892     // This call is not redundant when size == 0 because it tells us what
 893     // the current state is.
 894     StreamingUtf8Validator::State state = incoming_utf8_validator_.AddBytes(
 895         size ? data_buffer->data() : NULL, size);
 896     if (state == StreamingUtf8Validator::INVALID ||
 897         (state == StreamingUtf8Validator::VALID_MIDPOINT && final)) {
 898       return FailChannel("Could not decode a text frame as UTF-8.",
 899                          kWebSocketErrorProtocolError,
 900                          "Invalid UTF-8 in text frame");
 901     }
 902     receiving_text_message_ = !final;
 903     DCHECK(!final || state == StreamingUtf8Validator::VALID_ENDPOINT);
 904   }
 905   if (size == 0U && !final)
 906     return CHANNEL_ALIVE;
 907
 908   initial_frame_forwarded_ = !final;
 909   if (size > base::checked_cast<size_t>(current_receive_quota_) ||
 910       !pending_received_frames_.empty()) {
 911     const bool no_quota = (current_receive_quota_ == 0);
 912     DCHECK(no_quota || pending_received_frames_.empty());
 913     DVLOG(3) << "Queueing frame to renderer due to quota. quota="
 914              << current_receive_quota_ << " size=" << size;
 915     WebSocketFrameHeader::OpCode opcode_to_queue =
 916         no_quota ? opcode_to_send : WebSocketFrameHeader::kOpCodeContinuation;
 917     pending_received_frames_.push(PendingReceivedFrame(
 918         final, opcode_to_queue, data_buffer, current_receive_quota_, size));
 919     if (no_quota)
 920       return CHANNEL_ALIVE;
 921     size = current_receive_quota_;
 922     final = false;
 923   }
 924
 925   // TODO(ricea): Can this copy be eliminated?
 926   const char* const data_begin = size ? data_buffer->data() : NULL;
 927   const char* const data_end = data_begin + size;
 928   const std::vector<char> data(data_begin, data_end);
 929   current_receive_quota_ -= size;
 930   DCHECK_GE(current_receive_quota_, 0);
 931
 932   // Sends the received frame to the renderer process.
 933   return event_interface_->OnDataFrame(final, opcode_to_send, data);
 934 }
 935
 936 ChannelState WebSocketChannel::SendFrameFromIOBuffer(
 937     bool fin,
 938     WebSocketFrameHeader::OpCode op_code,
 939     const scoped_refptr<IOBuffer>& buffer,
 940     size_t size) {
 941   DCHECK(state_ == CONNECTED || state_ == RECV_CLOSED);
 942   DCHECK(stream_);
 943
 944   scoped_ptr<WebSocketFrame> frame(new WebSocketFrame(op_code));
 945   WebSocketFrameHeader& header = frame->header;
 946   header.final = fin;
 947   header.masked = true;
 948   header.payload_length = size;
 949   frame->data = buffer;
 950
 951   if (data_being_sent_) {
 952     // Either the link to the WebSocket server is saturated, or several messages
 953     // are being sent in a batch.
 954     // TODO(ricea): Keep some statistics to work out the situation and adjust
 955     // quota appropriately.
 956     if (!data_to_send_next_)
 957       data_to_send_next_.reset(new SendBuffer);
 958     data_to_send_next_->AddFrame(frame.Pass());
 959     return CHANNEL_ALIVE;
 960   }
 961
 962   data_being_sent_.reset(new SendBuffer);
 963   data_being_sent_->AddFrame(frame.Pass());
 964   return WriteFrames();
 965 }
 966
 967 ChannelState WebSocketChannel::FailChannel(const std::string& message,
 968                                            uint16 code,
 969                                            const std::string& reason) {
 970   DCHECK_NE(FRESHLY_CONSTRUCTED, state_);
 971   DCHECK_NE(CONNECTING, state_);
 972   DCHECK_NE(CLOSED, state_);
 973
 974   // TODO(ricea): Logging.
 975   if (state_ == CONNECTED) {
 976     if (SendClose(code, reason) == CHANNEL_DELETED)
 977       return CHANNEL_DELETED;
 978   }
 979
 980   // Careful study of RFC6455 section 7.1.7 and 7.1.1 indicates the browser
 981   // should close the connection itself without waiting for the closing
 982   // handshake.
 983   stream_->Close();
 984   SetState(CLOSED);
 985   return event_interface_->OnFailChannel(message);
 986 }
 987
 988 ChannelState WebSocketChannel::SendClose(uint16 code,
 989                                          const std::string& reason) {
 990   DCHECK(state_ == CONNECTED || state_ == RECV_CLOSED);
 991   DCHECK_LE(reason.size(), kMaximumCloseReasonLength);
 992   scoped_refptr<IOBuffer> body;
 993   size_t size = 0;
 994   if (code == kWebSocketErrorNoStatusReceived) {
 995     // Special case: translate kWebSocketErrorNoStatusReceived into a Close
 996     // frame with no payload.
 997     DCHECK(reason.empty());
 998     body = new IOBuffer(0);
 999   } else {
1000     const size_t payload_length = kWebSocketCloseCodeLength + reason.length();
1001     body = new IOBuffer(payload_length);
1002     size = payload_length;
1003     base::WriteBigEndian(body->data(), code);
1004     COMPILE_ASSERT(sizeof(code) == kWebSocketCloseCodeLength,
1005                    they_should_both_be_two);
1006     std::copy(
1007         reason.begin(), reason.end(), body->data() + kWebSocketCloseCodeLength);
1008   }
1009   // This use of base::Unretained() is safe because we stop the timer in the
1010   // destructor.
1011   timer_.Start(
1012       FROM_HERE,
1013       timeout_,
1014       base::Bind(&WebSocketChannel::CloseTimeout, base::Unretained(this)));
1015   if (SendFrameFromIOBuffer(
1016           true, WebSocketFrameHeader::kOpCodeClose, body, size) ==
1017       CHANNEL_DELETED)
1018     return CHANNEL_DELETED;
1019   return CHANNEL_ALIVE;
1020 }
1021
1022 bool WebSocketChannel::ParseClose(const scoped_refptr<IOBuffer>& buffer,
1023                                   size_t size,
1024                                   uint16* code,
1025                                   std::string* reason,
1026                                   std::string* message) {
1027   reason->clear();
1028   if (size < kWebSocketCloseCodeLength) {
1029     if (size == 0U) {
1030       *code = kWebSocketErrorNoStatusReceived;
1031       return true;
1032     }
1033
1034     DVLOG(1) << "Close frame with payload size " << size << " received "
1035              << "(the first byte is " << std::hex
1036              << static_cast<int>(buffer->data()[0]) << ")";
1037     *code = kWebSocketErrorProtocolError;
1038     *message =
1039         "Received a broken close frame containing an invalid size body.";
1040     return false;
1041   }
1042
1043   const char* data = buffer->data();
1044   uint16 unchecked_code = 0;
1045   base::ReadBigEndian(data, &unchecked_code);
1046   COMPILE_ASSERT(sizeof(unchecked_code) == kWebSocketCloseCodeLength,
1047                  they_should_both_be_two_bytes);
1048
1049   switch (unchecked_code) {
1050     case kWebSocketErrorNoStatusReceived:
1051     case kWebSocketErrorAbnormalClosure:
1052     case kWebSocketErrorTlsHandshake:
1053       *code = kWebSocketErrorProtocolError;
1054       *message =
1055           "Received a broken close frame containing a reserved status code.";
1056       return false;
1057
1058     default:
1059       *code = unchecked_code;
1060       break;
1061   }
1062
1063   std::string text(data + kWebSocketCloseCodeLength, data + size);
1064   if (StreamingUtf8Validator::Validate(text)) {
1065     reason->swap(text);
1066     return true;
1067   }
1068
1069   *code = kWebSocketErrorProtocolError;
1070   *reason = "Invalid UTF-8 in Close frame";
1071   *message = "Received a broken close frame containing invalid UTF-8.";
1072   return false;
1073 }
1074
1075 ChannelState WebSocketChannel::DoDropChannel(bool was_clean,
1076                                              uint16 code,
1077                                              const std::string& reason) {
1078   if (CHANNEL_DELETED ==
1079       notification_sender_->SendImmediately(event_interface_.get()))
1080     return CHANNEL_DELETED;
1081   ChannelState result =
1082       event_interface_->OnDropChannel(was_clean, code, reason);
1083   DCHECK_EQ(CHANNEL_DELETED, result);
1084   return result;
1085 }
1086
1087 void WebSocketChannel::CloseTimeout() {
1088   stream_->Close();
1089   SetState(CLOSED);
1090   AllowUnused(DoDropChannel(false, kWebSocketErrorAbnormalClosure, ""));
1091   // |this| has been deleted.
1092 }
1093
1094 }  // namespace net