Add new HTTP/2 and HPACK decoder in net/http2/.

net/http2/decoder/http2_frame_decoder.cc

Index: net/http2/decoder/http2_frame_decoder.cc
diff --git a/net/http2/decoder/http2_frame_decoder.cc b/net/http2/decoder/http2_frame_decoder.cc
new file mode 100644
index 0000000000000000000000000000000000000000..fe24f91644cdd27208f41ee9872a28407274d858
--- /dev/null
+++ b/net/http2/decoder/http2_frame_decoder.cc
@@ -0,0 +1,426 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/http2/decoder/http2_frame_decoder.h"
+
+#include "net/http2/http2_constants.h"
+
+namespace net {
+
+std::ostream& operator<<(std::ostream& out, Http2FrameDecoder::State v) {
+  switch (v) {
+    case Http2FrameDecoder::State::kStartDecodingHeader:
+      return out << "kStartDecodingHeader";
+    case Http2FrameDecoder::State::kResumeDecodingHeader:
+      return out << "kResumeDecodingHeader";
+    case Http2FrameDecoder::State::kResumeDecodingPayload:
+      return out << "kResumeDecodingPayload";
+    case Http2FrameDecoder::State::kDiscardPayload:
+      return out << "kDiscardPayload";
+  }
+  return out << static_cast<int>(v);
+}
+
+Http2FrameDecoder::Http2FrameDecoder(Http2FrameDecoderListener* listener)
+    : state_(State::kStartDecodingHeader),
+      maximum_payload_size_(Http2SettingsInfo::DefaultMaxFrameSize()) {
+  set_listener(listener);
+}
+
+void Http2FrameDecoder::set_listener(Http2FrameDecoderListener* listener) {
+  if (listener == nullptr) {
+    listener = &no_op_listener_;
+  }
+  frame_decoder_state_.set_listener(listener);
+}
+
+Http2FrameDecoderListener* Http2FrameDecoder::listener() const {
+  return frame_decoder_state_.listener();
+}
+
+DecodeStatus Http2FrameDecoder::DecodeFrame(DecodeBuffer* db) {
+  DVLOG(2) << "Http2FrameDecoder::DecodeFrame state=" << state_;
+  switch (state_) {
+    case State::kStartDecodingHeader:
+      if (frame_decoder_state_.StartDecodingFrameHeader(db)) {
+        return StartDecodingPayload(db);
+      }
+      state_ = State::kResumeDecodingHeader;
+      return DecodeStatus::kDecodeInProgress;
+
+    case State::kResumeDecodingHeader:
+      if (frame_decoder_state_.ResumeDecodingFrameHeader(db)) {
+        return StartDecodingPayload(db);
+      }
+      return DecodeStatus::kDecodeInProgress;
+
+    case State::kResumeDecodingPayload:
+      return ResumeDecodingPayload(db);
+
+    case State::kDiscardPayload:
+      return DiscardPayload(db);
+  }
+
+  NOTREACHED();
+  return DecodeStatus::kDecodeError;
+}
+
+size_t Http2FrameDecoder::remaining_payload() const {
+  return frame_decoder_state_.remaining_payload();
+}
+
+uint32_t Http2FrameDecoder::remaining_padding() const {
+  return frame_decoder_state_.remaining_padding();
+}
+
+DecodeStatus Http2FrameDecoder::StartDecodingPayload(DecodeBuffer* db) {
+  const Http2FrameHeader& header = frame_header();
+
+  // TODO(jamessynge): Remove OnFrameHeader once done with supporting
+  // SpdyFramer's exact states.
+  if (!listener()->OnFrameHeader(header)) {
+    DVLOG(2) << "OnFrameHeader rejected the frame, will discard; header: "
+             << header;
+    state_ = State::kDiscardPayload;
+    frame_decoder_state_.InitializeRemainders();
+    return DecodeStatus::kDecodeError;
+  }
+
+  if (header.payload_length > maximum_payload_size_) {
+    DVLOG(2) << "Payload length is greater than allowed: "
+             << header.payload_length << " > " << maximum_payload_size_
+             << "\n   header: " << header;
+    state_ = State::kDiscardPayload;
+    frame_decoder_state_.InitializeRemainders();
+    listener()->OnFrameSizeError(header);
+    return DecodeStatus::kDecodeError;
+  }
+
+  // The decode buffer can extend across many frames. Make sure that the
+  // buffer we pass to the start method that is specific to the frame type
+  // does not exend beyond this frame.
+  DecodeBufferSubset subset(db, header.payload_length);
+  DecodeStatus status;
+  switch (header.type) {
+    case Http2FrameType::DATA:
+      status = StartDecodingDataPayload(&subset);
+      break;
+
+    case Http2FrameType::HEADERS:
+      status = StartDecodingHeadersPayload(&subset);
+      break;
+
+    case Http2FrameType::PRIORITY:
+      status = StartDecodingPriorityPayload(&subset);
+      break;
+
+    case Http2FrameType::RST_STREAM:
+      status = StartDecodingRstStreamPayload(&subset);
+      break;
+
+    case Http2FrameType::SETTINGS:
+      status = StartDecodingSettingsPayload(&subset);
+      break;
+
+    case Http2FrameType::PUSH_PROMISE:
+      status = StartDecodingPushPromisePayload(&subset);
+      break;
+
+    case Http2FrameType::PING:
+      status = StartDecodingPingPayload(&subset);
+      break;
+
+    case Http2FrameType::GOAWAY:
+      status = StartDecodingGoAwayPayload(&subset);
+      break;
+
+    case Http2FrameType::WINDOW_UPDATE:
+      status = StartDecodingWindowUpdatePayload(&subset);
+      break;
+
+    case Http2FrameType::CONTINUATION:
+      status = StartDecodingContinuationPayload(&subset);
+      break;
+
+    case Http2FrameType::ALTSVC:
+      status = StartDecodingAltSvcPayload(&subset);
+      break;
+
+    default:
+      status = StartDecodingUnknownPayload(&subset);
+      break;
+  }
+
+  if (status == DecodeStatus::kDecodeDone) {
+    state_ = State::kStartDecodingHeader;
+    return status;
+  } else if (status == DecodeStatus::kDecodeInProgress) {
+    state_ = State::kResumeDecodingPayload;
+    return status;
+  } else {
+    state_ = State::kDiscardPayload;
+    return status;
+  }
+}
+
+DecodeStatus Http2FrameDecoder::ResumeDecodingPayload(DecodeBuffer* db) {
+  // The decode buffer can extend across many frames. Make sure that the
+  // buffer we pass to the start method that is specific to the frame type
+  // does not exend beyond this frame.
+  size_t remaining = frame_decoder_state_.remaining_total_payload();
+  DCHECK_LE(remaining, frame_header().payload_length);
+  DecodeBufferSubset subset(db, remaining);
+  DecodeStatus status;
+  switch (frame_header().type) {
+    case Http2FrameType::DATA:
+      status = ResumeDecodingDataPayload(&subset);
+      break;
+
+    case Http2FrameType::HEADERS:
+      status = ResumeDecodingHeadersPayload(&subset);
+      break;
+
+    case Http2FrameType::PRIORITY:
+      status = ResumeDecodingPriorityPayload(&subset);
+      break;
+
+    case Http2FrameType::RST_STREAM:
+      status = ResumeDecodingRstStreamPayload(&subset);
+      break;
+
+    case Http2FrameType::SETTINGS:
+      status = ResumeDecodingSettingsPayload(&subset);
+      break;
+
+    case Http2FrameType::PUSH_PROMISE:
+      status = ResumeDecodingPushPromisePayload(&subset);
+      break;
+
+    case Http2FrameType::PING:
+      status = ResumeDecodingPingPayload(&subset);
+      break;
+
+    case Http2FrameType::GOAWAY:
+      status = ResumeDecodingGoAwayPayload(&subset);
+      break;
+
+    case Http2FrameType::WINDOW_UPDATE:
+      status = ResumeDecodingWindowUpdatePayload(&subset);
+      break;
+
+    case Http2FrameType::CONTINUATION:
+      status = ResumeDecodingContinuationPayload(&subset);
+      break;
+
+    case Http2FrameType::ALTSVC:
+      status = ResumeDecodingAltSvcPayload(&subset);
+      break;
+
+    default:
+      status = ResumeDecodingUnknownPayload(&subset);
+      break;
+  }
+
+  if (status == DecodeStatus::kDecodeDone) {
+    state_ = State::kStartDecodingHeader;
+    return status;
+  } else if (status == DecodeStatus::kDecodeInProgress) {
+    return status;
+  } else {
+    state_ = State::kDiscardPayload;
+    return status;
+  }
+}
+
+// Clear any of the flags in the frame header that aren't set in valid_flags.
+void Http2FrameDecoder::RetainFlags(uint8_t valid_flags) {
+  frame_decoder_state_.RetainFlags(valid_flags);
+}
+
+// Clear all of the flags in the frame header; for use with frame types that
+// don't define any flags, such as WINDOW_UPDATE.
+void Http2FrameDecoder::ClearFlags() {
+  frame_decoder_state_.ClearFlags();
+}
+
+DecodeStatus Http2FrameDecoder::StartDecodingAltSvcPayload(DecodeBuffer* db) {
+  ClearFlags();
+  return altsvc_payload_decoder_.StartDecodingPayload(&frame_decoder_state_,
+                                                      db);
+}
+DecodeStatus Http2FrameDecoder::ResumeDecodingAltSvcPayload(DecodeBuffer* db) {
+  // The frame is not paddable.
+  DCHECK_EQ(frame_decoder_state_.remaining_total_payload(),
+            frame_decoder_state_.remaining_payload());
+  return altsvc_payload_decoder_.ResumeDecodingPayload(&frame_decoder_state_,
+                                                       db);
+}
+
+DecodeStatus Http2FrameDecoder::StartDecodingContinuationPayload(
+    DecodeBuffer* db) {
+  RetainFlags(Http2FrameFlag::FLAG_END_HEADERS);
+  return continuation_payload_decoder_.StartDecodingPayload(
+      &frame_decoder_state_, db);
+}
+DecodeStatus Http2FrameDecoder::ResumeDecodingContinuationPayload(
+    DecodeBuffer* db) {
+  // The frame is not paddable.
+  DCHECK_EQ(frame_decoder_state_.remaining_total_payload(),
+            frame_decoder_state_.remaining_payload());
+  return continuation_payload_decoder_.ResumeDecodingPayload(
+      &frame_decoder_state_, db);
+}
+
+DecodeStatus Http2FrameDecoder::StartDecodingDataPayload(DecodeBuffer* db) {
+  RetainFlags(Http2FrameFlag::FLAG_END_STREAM | Http2FrameFlag::FLAG_PADDED);
+  return data_payload_decoder_.StartDecodingPayload(&frame_decoder_state_, db);
+}
+DecodeStatus Http2FrameDecoder::ResumeDecodingDataPayload(DecodeBuffer* db) {
+  return data_payload_decoder_.ResumeDecodingPayload(&frame_decoder_state_, db);
+}
+
+DecodeStatus Http2FrameDecoder::StartDecodingGoAwayPayload(DecodeBuffer* db) {
+  ClearFlags();
+  return goaway_payload_decoder_.StartDecodingPayload(&frame_decoder_state_,
+                                                      db);
+}
+DecodeStatus Http2FrameDecoder::ResumeDecodingGoAwayPayload(DecodeBuffer* db) {
+  // The frame is not paddable.
+  DCHECK_EQ(frame_decoder_state_.remaining_total_payload(),
+            frame_decoder_state_.remaining_payload());
+  return goaway_payload_decoder_.ResumeDecodingPayload(&frame_decoder_state_,
+                                                       db);
+}
+
+DecodeStatus Http2FrameDecoder::StartDecodingHeadersPayload(DecodeBuffer* db) {
+  RetainFlags(Http2FrameFlag::FLAG_END_STREAM |
+              Http2FrameFlag::FLAG_END_HEADERS | Http2FrameFlag::FLAG_PADDED |
+              Http2FrameFlag::FLAG_PRIORITY);
+  return headers_payload_decoder_.StartDecodingPayload(&frame_decoder_state_,
+                                                       db);
+}
+DecodeStatus Http2FrameDecoder::ResumeDecodingHeadersPayload(DecodeBuffer* db) {
+  DCHECK_LE(frame_decoder_state_.remaining_payload_and_padding(),
+            frame_header().payload_length);
+  return headers_payload_decoder_.ResumeDecodingPayload(&frame_decoder_state_,
+                                                        db);
+}
+
+DecodeStatus Http2FrameDecoder::StartDecodingPingPayload(DecodeBuffer* db) {
+  RetainFlags(Http2FrameFlag::FLAG_ACK);
+  return ping_payload_decoder_.StartDecodingPayload(&frame_decoder_state_, db);
+}
+DecodeStatus Http2FrameDecoder::ResumeDecodingPingPayload(DecodeBuffer* db) {
+  // The frame is not paddable.
+  DCHECK_EQ(frame_decoder_state_.remaining_total_payload(),
+            frame_decoder_state_.remaining_payload());
+  return ping_payload_decoder_.ResumeDecodingPayload(&frame_decoder_state_, db);
+}
+
+DecodeStatus Http2FrameDecoder::StartDecodingPriorityPayload(DecodeBuffer* db) {
+  ClearFlags();
+  return priority_payload_decoder_.StartDecodingPayload(&frame_decoder_state_,
+                                                        db);
+}
+DecodeStatus Http2FrameDecoder::ResumeDecodingPriorityPayload(
+    DecodeBuffer* db) {
+  // The frame is not paddable.
+  DCHECK_EQ(frame_decoder_state_.remaining_total_payload(),
+            frame_decoder_state_.remaining_payload());
+  return priority_payload_decoder_.ResumeDecodingPayload(&frame_decoder_state_,
+                                                         db);
+}
+
+DecodeStatus Http2FrameDecoder::StartDecodingPushPromisePayload(
+    DecodeBuffer* db) {
+  RetainFlags(Http2FrameFlag::FLAG_END_HEADERS | Http2FrameFlag::FLAG_PADDED);
+  return push_promise_payload_decoder_.StartDecodingPayload(
+      &frame_decoder_state_, db);
+}
+DecodeStatus Http2FrameDecoder::ResumeDecodingPushPromisePayload(
+    DecodeBuffer* db) {
+  DCHECK_LE(frame_decoder_state_.remaining_payload_and_padding(),
+            frame_header().payload_length);
+  return push_promise_payload_decoder_.ResumeDecodingPayload(
+      &frame_decoder_state_, db);
+}
+
+DecodeStatus Http2FrameDecoder::StartDecodingRstStreamPayload(
+    DecodeBuffer* db) {
+  ClearFlags();
+  return rst_stream_payload_decoder_.StartDecodingPayload(&frame_decoder_state_,
+                                                          db);
+}
+DecodeStatus Http2FrameDecoder::ResumeDecodingRstStreamPayload(
+    DecodeBuffer* db) {
+  // The frame is not paddable.
+  DCHECK_EQ(frame_decoder_state_.remaining_total_payload(),
+            frame_decoder_state_.remaining_payload());
+  return rst_stream_payload_decoder_.ResumeDecodingPayload(
+      &frame_decoder_state_, db);
+}
+
+DecodeStatus Http2FrameDecoder::StartDecodingSettingsPayload(DecodeBuffer* db) {
+  RetainFlags(Http2FrameFlag::FLAG_ACK);
+  return settings_payload_decoder_.StartDecodingPayload(&frame_decoder_state_,
+                                                        db);
+}
+DecodeStatus Http2FrameDecoder::ResumeDecodingSettingsPayload(
+    DecodeBuffer* db) {
+  // The frame is not paddable.
+  DCHECK_EQ(frame_decoder_state_.remaining_total_payload(),
+            frame_decoder_state_.remaining_payload());
+  return settings_payload_decoder_.ResumeDecodingPayload(&frame_decoder_state_,
+                                                         db);
+}
+
+DecodeStatus Http2FrameDecoder::StartDecodingUnknownPayload(DecodeBuffer* db) {
+  // We don't known what type of frame this is, so we don't know which flags
+  // are valid, so we don't touch them.
+  return unknown_payload_decoder_.StartDecodingPayload(&frame_decoder_state_,
+                                                       db);
+}
+DecodeStatus Http2FrameDecoder::ResumeDecodingUnknownPayload(DecodeBuffer* db) {
+  // We don't known what type of frame this is, so we treat it as not paddable.
+  DCHECK_EQ(frame_decoder_state_.remaining_total_payload(),
+            frame_decoder_state_.remaining_payload());
+  return unknown_payload_decoder_.ResumeDecodingPayload(&frame_decoder_state_,
+                                                        db);
+}
+
+DecodeStatus Http2FrameDecoder::StartDecodingWindowUpdatePayload(
+    DecodeBuffer* db) {
+  ClearFlags();
+  return window_update_payload_decoder_.StartDecodingPayload(
+      &frame_decoder_state_, db);
+}
+DecodeStatus Http2FrameDecoder::ResumeDecodingWindowUpdatePayload(
+    DecodeBuffer* db) {
+  // The frame is not paddable.
+  DCHECK_EQ(frame_decoder_state_.remaining_total_payload(),
+            frame_decoder_state_.remaining_payload());
+  return window_update_payload_decoder_.ResumeDecodingPayload(
+      &frame_decoder_state_, db);
+}
+
+DecodeStatus Http2FrameDecoder::DiscardPayload(DecodeBuffer* db) {
+  DVLOG(2) << "remaining_payload=" << frame_decoder_state_.remaining_payload_
+           << "; remaining_padding=" << frame_decoder_state_.remaining_padding_;
+  frame_decoder_state_.remaining_payload_ +=
+      frame_decoder_state_.remaining_padding_;
+  frame_decoder_state_.remaining_padding_ = 0;
+  const size_t avail = frame_decoder_state_.AvailablePayload(db);
+  DVLOG(2) << "avail=" << avail;
+  if (avail > 0) {
+    frame_decoder_state_.ConsumePayload(avail);
+    db->AdvanceCursor(avail);
+  }
+  if (frame_decoder_state_.remaining_payload_ == 0) {
+    state_ = State::kStartDecodingHeader;
+    return DecodeStatus::kDecodeDone;
+  }
+  return DecodeStatus::kDecodeInProgress;
+}
+
+}  // namespace net