1 // Copyright 2013 The Chromium Authors
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_stream.h"
6
7 #include <stddef.h>
8 #include <stdint.h>
9
10 #include <algorithm>
11 #include <limits>
12 #include <ostream>
13 #include <utility>
14
15 #include "base/check.h"
16 #include "base/check_op.h"
17 #include "base/functional/bind.h"
18 #include "base/functional/callback.h"
19 #include "base/logging.h"
20 #include "base/numerics/safe_conversions.h"
21 #include "base/values.h"
22 #include "build/build_config.h"
23 #include "net/base/io_buffer.h"
24 #include "net/base/net_errors.h"
25 #include "net/log/net_log_event_type.h"
26 #include "net/socket/client_socket_handle.h"
27 #include "net/traffic_annotation/network_traffic_annotation.h"
28 #include "net/websockets/websocket_basic_stream_adapters.h"
29 #include "net/websockets/websocket_errors.h"
30 #include "net/websockets/websocket_frame.h"
31
32 namespace net {
33
34 namespace {
35
36 // Please refer to the comment in class header if the usage changes.
37 constexpr net::NetworkTrafficAnnotationTag kTrafficAnnotation =
38 net::DefineNetworkTrafficAnnotation("websocket_basic_stream", R"(
39 semantics {
40 sender: "WebSocket Basic Stream"
41 description:
42 "Implementation of WebSocket API from web content (a page the user "
43 "visits)."
44 trigger: "Website calls the WebSocket API."
45 data:
46 "Any data provided by web content, masked and framed in accordance "
47 "with RFC6455."
48 destination: OTHER
49 destination_other:
50 "The address that the website has chosen to communicate to."
51 }
52 policy {
53 cookies_allowed: YES
54 cookies_store: "user"
55 setting: "These requests cannot be disabled."
56 policy_exception_justification:
57 "Not implemented. WebSocket is a core web platform API."
58 }
59 comments:
60 "The browser will never add cookies to a WebSocket message. But the "
61 "handshake that was performed when the WebSocket connection was "
62 "established may have contained cookies."
63 )");
64
65 // This uses type uint64_t to match the definition of
66 // WebSocketFrameHeader::payload_length in websocket_frame.h.
67 constexpr uint64_t kMaxControlFramePayload = 125;
68
69 // The number of bytes to attempt to read at a time. It's used only for high
70 // throughput connections.
71 // TODO(ricea): See if there is a better number or algorithm to fulfill our
72 // requirements:
73 // 1. We would like to use minimal memory on low-bandwidth or idle connections
74 // 2. We would like to read as close to line speed as possible on
75 // high-bandwidth connections
76 // 3. We can't afford to cause jank on the IO thread by copying large buffers
77 // around
78 // 4. We would like to hit any sweet-spots that might exist in terms of network
79 // packet sizes / encryption block sizes / IPC alignment issues, etc.
80 #if BUILDFLAG(IS_ANDROID)
81 constexpr size_t kLargeReadBufferSize = 32 * 1024;
82 #else
83 // |2^n - delta| is better than 2^n on Linux. See crrev.com/c/1792208.
84 constexpr size_t kLargeReadBufferSize = 131000;
85 #endif
86
87 // The number of bytes to attempt to read at a time. It's set as an initial read
88 // buffer size and used for low throughput connections.
89 constexpr size_t kSmallReadBufferSize = 1000;
90
91 // The threshold to decide whether to switch the read buffer size.
92 constexpr double kThresholdInBytesPerSecond = 1200 * 1000;
93
94 // Returns the total serialized size of |frames|. This function assumes that
95 // |frames| will be serialized with mask field. This function forces the
96 // masked bit of the frames on.
CalculateSerializedSizeAndTurnOnMaskBit(std::vector<std::unique_ptr<WebSocketFrame>> * frames)97 int CalculateSerializedSizeAndTurnOnMaskBit(
98 std::vector<std::unique_ptr<WebSocketFrame>>* frames) {
99 constexpr uint64_t kMaximumTotalSize = std::numeric_limits<int>::max();
100
101 uint64_t total_size = 0;
102 for (const auto& frame : *frames) {
103 // Force the masked bit on.
104 frame->header.masked = true;
105 // We enforce flow control so the renderer should never be able to force us
106 // to cache anywhere near 2GB of frames.
107 uint64_t frame_size = frame->header.payload_length +
108 GetWebSocketFrameHeaderSize(frame->header);
109 CHECK_LE(frame_size, kMaximumTotalSize - total_size)
110 << "Aborting to prevent overflow";
111 total_size += frame_size;
112 }
113 return static_cast<int>(total_size);
114 }
115
NetLogBufferSizeParam(int buffer_size)116 base::Value::Dict NetLogBufferSizeParam(int buffer_size) {
117 base::Value::Dict dict;
118 dict.Set("read_buffer_size_in_bytes", buffer_size);
119 return dict;
120 }
121
NetLogFrameHeaderParam(const WebSocketFrameHeader * header)122 base::Value::Dict NetLogFrameHeaderParam(const WebSocketFrameHeader* header) {
123 base::Value::Dict dict;
124 dict.Set("final", header->final);
125 dict.Set("reserved1", header->reserved1);
126 dict.Set("reserved2", header->reserved2);
127 dict.Set("reserved3", header->reserved3);
128 dict.Set("opcode", header->opcode);
129 dict.Set("masked", header->masked);
130 dict.Set("payload_length", static_cast<double>(header->payload_length));
131 return dict;
132 }
133
134 } // namespace
135
136 WebSocketBasicStream::BufferSizeManager::BufferSizeManager() = default;
137
138 WebSocketBasicStream::BufferSizeManager::~BufferSizeManager() = default;
139
OnRead(base::TimeTicks now)140 void WebSocketBasicStream::BufferSizeManager::OnRead(base::TimeTicks now) {
141 read_start_timestamps_.push(now);
142 }
143
OnReadComplete(base::TimeTicks now,int size)144 void WebSocketBasicStream::BufferSizeManager::OnReadComplete(
145 base::TimeTicks now,
146 int size) {
147 DCHECK_GT(size, 0);
148 // This cannot overflow because the result is at most
149 // kLargeReadBufferSize*rolling_average_window_.
150 rolling_byte_total_ += size;
151 recent_read_sizes_.push(size);
152 DCHECK_LE(read_start_timestamps_.size(), rolling_average_window_);
153 if (read_start_timestamps_.size() == rolling_average_window_) {
154 DCHECK_EQ(read_start_timestamps_.size(), recent_read_sizes_.size());
155 base::TimeDelta duration = now - read_start_timestamps_.front();
156 base::TimeDelta threshold_duration =
157 base::Seconds(rolling_byte_total_ / kThresholdInBytesPerSecond);
158 read_start_timestamps_.pop();
159 rolling_byte_total_ -= recent_read_sizes_.front();
160 recent_read_sizes_.pop();
161 if (threshold_duration < duration) {
162 buffer_size_ = BufferSize::kSmall;
163 } else {
164 buffer_size_ = BufferSize::kLarge;
165 }
166 }
167 }
168
WebSocketBasicStream(std::unique_ptr<Adapter> connection,const scoped_refptr<GrowableIOBuffer> & http_read_buffer,const std::string & sub_protocol,const std::string & extensions,const NetLogWithSource & net_log)169 WebSocketBasicStream::WebSocketBasicStream(
170 std::unique_ptr<Adapter> connection,
171 const scoped_refptr<GrowableIOBuffer>& http_read_buffer,
172 const std::string& sub_protocol,
173 const std::string& extensions,
174 const NetLogWithSource& net_log)
175 : read_buffer_(
176 base::MakeRefCounted<IOBufferWithSize>(kSmallReadBufferSize)),
177 target_read_buffer_size_(read_buffer_->size()),
178 connection_(std::move(connection)),
179 http_read_buffer_(http_read_buffer),
180 sub_protocol_(sub_protocol),
181 extensions_(extensions),
182 net_log_(net_log),
183 generate_websocket_masking_key_(&GenerateWebSocketMaskingKey) {
184 // http_read_buffer_ should not be set if it contains no data.
185 if (http_read_buffer_.get() && http_read_buffer_->offset() == 0)
186 http_read_buffer_ = nullptr;
187 DCHECK(connection_->is_initialized());
188 }
189
~WebSocketBasicStream()190 WebSocketBasicStream::~WebSocketBasicStream() { Close(); }
191
ReadFrames(std::vector<std::unique_ptr<WebSocketFrame>> * frames,CompletionOnceCallback callback)192 int WebSocketBasicStream::ReadFrames(
193 std::vector<std::unique_ptr<WebSocketFrame>>* frames,
194 CompletionOnceCallback callback) {
195 read_callback_ = std::move(callback);
196 complete_control_frame_body_.clear();
197 if (http_read_buffer_ && is_http_read_buffer_decoded_) {
198 http_read_buffer_.reset();
199 }
200 return ReadEverything(frames);
201 }
202
WriteFrames(std::vector<std::unique_ptr<WebSocketFrame>> * frames,CompletionOnceCallback callback)203 int WebSocketBasicStream::WriteFrames(
204 std::vector<std::unique_ptr<WebSocketFrame>>* frames,
205 CompletionOnceCallback callback) {
206 // This function always concatenates all frames into a single buffer.
207 // TODO(ricea): Investigate whether it would be better in some cases to
208 // perform multiple writes with smaller buffers.
209
210 write_callback_ = std::move(callback);
211
212 // First calculate the size of the buffer we need to allocate.
213 int total_size = CalculateSerializedSizeAndTurnOnMaskBit(frames);
214 auto combined_buffer = base::MakeRefCounted<IOBufferWithSize>(total_size);
215
216 char* dest = combined_buffer->data();
217 int remaining_size = total_size;
218 for (const auto& frame : *frames) {
219 net_log_.AddEvent(net::NetLogEventType::WEBSOCKET_SENT_FRAME_HEADER,
220 [&] { return NetLogFrameHeaderParam(&frame->header); });
221 WebSocketMaskingKey mask = generate_websocket_masking_key_();
222 int result =
223 WriteWebSocketFrameHeader(frame->header, &mask, dest, remaining_size);
224 DCHECK_NE(ERR_INVALID_ARGUMENT, result)
225 << "WriteWebSocketFrameHeader() says that " << remaining_size
226 << " is not enough to write the header in. This should not happen.";
227 CHECK_GE(result, 0) << "Potentially security-critical check failed";
228 dest += result;
229 remaining_size -= result;
230
231 CHECK_LE(frame->header.payload_length,
232 static_cast<uint64_t>(remaining_size));
233 const int frame_size = static_cast<int>(frame->header.payload_length);
234 if (frame_size > 0) {
235 const char* const frame_data = frame->payload;
236 std::copy(frame_data, frame_data + frame_size, dest);
237 MaskWebSocketFramePayload(mask, 0, dest, frame_size);
238 dest += frame_size;
239 remaining_size -= frame_size;
240 }
241 }
242 DCHECK_EQ(0, remaining_size) << "Buffer size calculation was wrong; "
243 << remaining_size << " bytes left over.";
244 auto drainable_buffer = base::MakeRefCounted<DrainableIOBuffer>(
245 std::move(combined_buffer), total_size);
246 return WriteEverything(drainable_buffer);
247 }
248
Close()249 void WebSocketBasicStream::Close() {
250 connection_->Disconnect();
251 }
252
GetSubProtocol() const253 std::string WebSocketBasicStream::GetSubProtocol() const {
254 return sub_protocol_;
255 }
256
GetExtensions() const257 std::string WebSocketBasicStream::GetExtensions() const { return extensions_; }
258
GetNetLogWithSource() const259 const NetLogWithSource& WebSocketBasicStream::GetNetLogWithSource() const {
260 return net_log_;
261 }
262
263 /*static*/
264 std::unique_ptr<WebSocketBasicStream>
CreateWebSocketBasicStreamForTesting(std::unique_ptr<ClientSocketHandle> connection,const scoped_refptr<GrowableIOBuffer> & http_read_buffer,const std::string & sub_protocol,const std::string & extensions,const NetLogWithSource & net_log,WebSocketMaskingKeyGeneratorFunction key_generator_function)265 WebSocketBasicStream::CreateWebSocketBasicStreamForTesting(
266 std::unique_ptr<ClientSocketHandle> connection,
267 const scoped_refptr<GrowableIOBuffer>& http_read_buffer,
268 const std::string& sub_protocol,
269 const std::string& extensions,
270 const NetLogWithSource& net_log,
271 WebSocketMaskingKeyGeneratorFunction key_generator_function) {
272 auto stream = std::make_unique<WebSocketBasicStream>(
273 std::make_unique<WebSocketClientSocketHandleAdapter>(
274 std::move(connection)),
275 http_read_buffer, sub_protocol, extensions, net_log);
276 stream->generate_websocket_masking_key_ = key_generator_function;
277 return stream;
278 }
279
ReadEverything(std::vector<std::unique_ptr<WebSocketFrame>> * frames)280 int WebSocketBasicStream::ReadEverything(
281 std::vector<std::unique_ptr<WebSocketFrame>>* frames) {
282 DCHECK(frames->empty());
283
284 // If there is data left over after parsing the HTTP headers, attempt to parse
285 // it as WebSocket frames.
286 if (http_read_buffer_.get() && !is_http_read_buffer_decoded_) {
287 DCHECK_GE(http_read_buffer_->offset(), 0);
288 is_http_read_buffer_decoded_ = true;
289 std::vector<std::unique_ptr<WebSocketFrameChunk>> frame_chunks;
290 if (!parser_.Decode(http_read_buffer_->StartOfBuffer(),
291 http_read_buffer_->offset(), &frame_chunks))
292 return WebSocketErrorToNetError(parser_.websocket_error());
293 if (!frame_chunks.empty()) {
294 int result = ConvertChunksToFrames(&frame_chunks, frames);
295 if (result != ERR_IO_PENDING)
296 return result;
297 }
298 }
299
300 // Run until socket stops giving us data or we get some frames.
301 while (true) {
302 if (buffer_size_manager_.buffer_size() != buffer_size_) {
303 read_buffer_ = base::MakeRefCounted<IOBufferWithSize>(
304 buffer_size_manager_.buffer_size() == BufferSize::kSmall
305 ? kSmallReadBufferSize
306 : kLargeReadBufferSize);
307 buffer_size_ = buffer_size_manager_.buffer_size();
308 net_log_.AddEvent(
309 net::NetLogEventType::WEBSOCKET_READ_BUFFER_SIZE_CHANGED,
310 [&] { return NetLogBufferSizeParam(read_buffer_->size()); });
311 }
312 buffer_size_manager_.OnRead(base::TimeTicks::Now());
313
314 // base::Unretained(this) here is safe because net::Socket guarantees not to
315 // call any callbacks after Disconnect(), which we call from the destructor.
316 // The caller of ReadEverything() is required to keep |frames| valid.
317 int result = connection_->Read(
318 read_buffer_.get(), read_buffer_->size(),
319 base::BindOnce(&WebSocketBasicStream::OnReadComplete,
320 base::Unretained(this), base::Unretained(frames)));
321 if (result == ERR_IO_PENDING)
322 return result;
323 result = HandleReadResult(result, frames);
324 if (result != ERR_IO_PENDING)
325 return result;
326 DCHECK(frames->empty());
327 }
328 }
329
OnReadComplete(std::vector<std::unique_ptr<WebSocketFrame>> * frames,int result)330 void WebSocketBasicStream::OnReadComplete(
331 std::vector<std::unique_ptr<WebSocketFrame>>* frames,
332 int result) {
333 result = HandleReadResult(result, frames);
334 if (result == ERR_IO_PENDING)
335 result = ReadEverything(frames);
336 if (result != ERR_IO_PENDING)
337 std::move(read_callback_).Run(result);
338 }
339
WriteEverything(const scoped_refptr<DrainableIOBuffer> & buffer)340 int WebSocketBasicStream::WriteEverything(
341 const scoped_refptr<DrainableIOBuffer>& buffer) {
342 while (buffer->BytesRemaining() > 0) {
343 // The use of base::Unretained() here is safe because on destruction we
344 // disconnect the socket, preventing any further callbacks.
345 int result = connection_->Write(
346 buffer.get(), buffer->BytesRemaining(),
347 base::BindOnce(&WebSocketBasicStream::OnWriteComplete,
348 base::Unretained(this), buffer),
349 kTrafficAnnotation);
350 if (result > 0) {
351 buffer->DidConsume(result);
352 } else {
353 return result;
354 }
355 }
356 return OK;
357 }
358
OnWriteComplete(const scoped_refptr<DrainableIOBuffer> & buffer,int result)359 void WebSocketBasicStream::OnWriteComplete(
360 const scoped_refptr<DrainableIOBuffer>& buffer,
361 int result) {
362 if (result < 0) {
363 DCHECK_NE(ERR_IO_PENDING, result);
364 std::move(write_callback_).Run(result);
365 return;
366 }
367
368 DCHECK_NE(0, result);
369
370 buffer->DidConsume(result);
371 result = WriteEverything(buffer);
372 if (result != ERR_IO_PENDING)
373 std::move(write_callback_).Run(result);
374 }
375
HandleReadResult(int result,std::vector<std::unique_ptr<WebSocketFrame>> * frames)376 int WebSocketBasicStream::HandleReadResult(
377 int result,
378 std::vector<std::unique_ptr<WebSocketFrame>>* frames) {
379 DCHECK_NE(ERR_IO_PENDING, result);
380 DCHECK(frames->empty());
381 if (result < 0)
382 return result;
383 if (result == 0)
384 return ERR_CONNECTION_CLOSED;
385
386 buffer_size_manager_.OnReadComplete(base::TimeTicks::Now(), result);
387
388 std::vector<std::unique_ptr<WebSocketFrameChunk>> frame_chunks;
389 if (!parser_.Decode(read_buffer_->data(), result, &frame_chunks))
390 return WebSocketErrorToNetError(parser_.websocket_error());
391 if (frame_chunks.empty())
392 return ERR_IO_PENDING;
393 return ConvertChunksToFrames(&frame_chunks, frames);
394 }
395
ConvertChunksToFrames(std::vector<std::unique_ptr<WebSocketFrameChunk>> * frame_chunks,std::vector<std::unique_ptr<WebSocketFrame>> * frames)396 int WebSocketBasicStream::ConvertChunksToFrames(
397 std::vector<std::unique_ptr<WebSocketFrameChunk>>* frame_chunks,
398 std::vector<std::unique_ptr<WebSocketFrame>>* frames) {
399 for (size_t i = 0; i < frame_chunks->size(); ++i) {
400 auto& chunk = (*frame_chunks)[i];
401 DCHECK(chunk == frame_chunks->back() || chunk->final_chunk)
402 << "Only last chunk can have |final_chunk| set to be false.";
403 if (const auto& header = chunk->header) {
404 net_log_.AddEvent(net::NetLogEventType::WEBSOCKET_RECV_FRAME_HEADER,
405 [&] { return NetLogFrameHeaderParam(header.get()); });
406 }
407 std::unique_ptr<WebSocketFrame> frame;
408 int result = ConvertChunkToFrame(std::move(chunk), &frame);
409 if (result != OK)
410 return result;
411 if (frame)
412 frames->push_back(std::move(frame));
413 }
414 frame_chunks->clear();
415 if (frames->empty())
416 return ERR_IO_PENDING;
417 return OK;
418 }
419
ConvertChunkToFrame(std::unique_ptr<WebSocketFrameChunk> chunk,std::unique_ptr<WebSocketFrame> * frame)420 int WebSocketBasicStream::ConvertChunkToFrame(
421 std::unique_ptr<WebSocketFrameChunk> chunk,
422 std::unique_ptr<WebSocketFrame>* frame) {
423 DCHECK(frame->get() == nullptr);
424 bool is_first_chunk = false;
425 if (chunk->header) {
426 DCHECK(current_frame_header_ == nullptr)
427 << "Received the header for a new frame without notification that "
428 << "the previous frame was complete (bug in WebSocketFrameParser?)";
429 is_first_chunk = true;
430 current_frame_header_.swap(chunk->header);
431 }
432 DCHECK(current_frame_header_) << "Unexpected header-less chunk received "
433 << "(final_chunk = " << chunk->final_chunk
434 << ", payload size = " << chunk->payload.size()
435 << ") (bug in WebSocketFrameParser?)";
436 const bool is_final_chunk = chunk->final_chunk;
437 const WebSocketFrameHeader::OpCode opcode = current_frame_header_->opcode;
438 if (WebSocketFrameHeader::IsKnownControlOpCode(opcode)) {
439 bool protocol_error = false;
440 if (!current_frame_header_->final) {
441 DVLOG(1) << "WebSocket protocol error. Control frame, opcode=" << opcode
442 << " received with FIN bit unset.";
443 protocol_error = true;
444 }
445 if (current_frame_header_->payload_length > kMaxControlFramePayload) {
446 DVLOG(1) << "WebSocket protocol error. Control frame, opcode=" << opcode
447 << ", payload_length=" << current_frame_header_->payload_length
448 << " exceeds maximum payload length for a control message.";
449 protocol_error = true;
450 }
451 if (protocol_error) {
452 current_frame_header_.reset();
453 return ERR_WS_PROTOCOL_ERROR;
454 }
455
456 if (!is_final_chunk) {
457 DVLOG(2) << "Encountered a split control frame, opcode " << opcode;
458 AddToIncompleteControlFrameBody(chunk->payload);
459 return OK;
460 }
461
462 if (!incomplete_control_frame_body_.empty()) {
463 DVLOG(2) << "Rejoining a split control frame, opcode " << opcode;
464 AddToIncompleteControlFrameBody(chunk->payload);
465 DCHECK(is_final_chunk);
466 DCHECK(complete_control_frame_body_.empty());
467 complete_control_frame_body_ = std::move(incomplete_control_frame_body_);
468 *frame = CreateFrame(is_final_chunk, complete_control_frame_body_);
469 return OK;
470 }
471 }
472
473 // Apply basic sanity checks to the |payload_length| field from the frame
474 // header. A check for exact equality can only be used when the whole frame
475 // arrives in one chunk.
476 DCHECK_GE(current_frame_header_->payload_length,
477 base::checked_cast<uint64_t>(chunk->payload.size()));
478 DCHECK(!is_first_chunk || !is_final_chunk ||
479 current_frame_header_->payload_length ==
480 base::checked_cast<uint64_t>(chunk->payload.size()));
481
482 // Convert the chunk to a complete frame.
483 *frame = CreateFrame(is_final_chunk, chunk->payload);
484 return OK;
485 }
486
CreateFrame(bool is_final_chunk,base::span<const char> data)487 std::unique_ptr<WebSocketFrame> WebSocketBasicStream::CreateFrame(
488 bool is_final_chunk,
489 base::span<const char> data) {
490 std::unique_ptr<WebSocketFrame> result_frame;
491 const bool is_final_chunk_in_message =
492 is_final_chunk && current_frame_header_->final;
493 const WebSocketFrameHeader::OpCode opcode = current_frame_header_->opcode;
494 // Empty frames convey no useful information unless they are the first frame
495 // (containing the type and flags) or have the "final" bit set.
496 if (is_final_chunk_in_message || data.size() > 0 ||
497 current_frame_header_->opcode !=
498 WebSocketFrameHeader::kOpCodeContinuation) {
499 result_frame = std::make_unique<WebSocketFrame>(opcode);
500 result_frame->header.CopyFrom(*current_frame_header_);
501 result_frame->header.final = is_final_chunk_in_message;
502 result_frame->header.payload_length = data.size();
503 result_frame->payload = data.data();
504 // Ensure that opcodes Text and Binary are only used for the first frame in
505 // the message. Also clear the reserved bits.
506 // TODO(ricea): If a future extension requires the reserved bits to be
507 // retained on continuation frames, make this behaviour conditional on a
508 // flag set at construction time.
509 if (!is_final_chunk && WebSocketFrameHeader::IsKnownDataOpCode(opcode)) {
510 current_frame_header_->opcode = WebSocketFrameHeader::kOpCodeContinuation;
511 current_frame_header_->reserved1 = false;
512 current_frame_header_->reserved2 = false;
513 current_frame_header_->reserved3 = false;
514 }
515 }
516 // Make sure that a frame header is not applied to any chunks that do not
517 // belong to it.
518 if (is_final_chunk)
519 current_frame_header_.reset();
520 return result_frame;
521 }
522
AddToIncompleteControlFrameBody(base::span<const char> data)523 void WebSocketBasicStream::AddToIncompleteControlFrameBody(
524 base::span<const char> data) {
525 if (data.empty()) {
526 return;
527 }
528 incomplete_control_frame_body_.insert(incomplete_control_frame_body_.end(),
529 data.begin(), data.end());
530 // This method checks for oversize control frames above, so as long as
531 // the frame parser is working correctly, this won't overflow. If a bug
532 // does cause it to overflow, it will CHECK() in
533 // AddToIncompleteControlFrameBody() without writing outside the buffer.
534 CHECK_LE(incomplete_control_frame_body_.size(), kMaxControlFramePayload)
535 << "Control frame body larger than frame header indicates; frame parser "
536 "bug?";
537 }
538
539 } // namespace net
540