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

net/http2/decoder/payload_decoders/payload_decoder_base_test_util.h

Index: net/http2/decoder/payload_decoders/payload_decoder_base_test_util.h
diff --git a/net/http2/decoder/payload_decoders/payload_decoder_base_test_util.h b/net/http2/decoder/payload_decoders/payload_decoder_base_test_util.h
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index 0000000000000000000000000000000000000000..b49b15efbd0e874582434a283a4c4f3b0941b98b
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+++ b/net/http2/decoder/payload_decoders/payload_decoder_base_test_util.h
@@ -0,0 +1,486 @@
+// 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.
+
+#ifndef NET_HTTP2_DECODER_PAYLOAD_DECODERS_PAYLOAD_DECODER_BASE_TEST_UTIL_H_
+#define NET_HTTP2_DECODER_PAYLOAD_DECODERS_PAYLOAD_DECODER_BASE_TEST_UTIL_H_
+
+// Base class for testing concrete payload decoder classes.
+
+#include <stddef.h>
+
+#include <string>
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/callback.h"
+#include "base/logging.h"
+#include "base/strings/string_piece.h"
+#include "net/http2/decoder/decode_buffer.h"
+#include "net/http2/decoder/decode_status.h"
+#include "net/http2/decoder/frame_decoder_state.h"
+#include "net/http2/decoder/frame_parts.h"
+#include "net/http2/decoder/http2_frame_decoder_listener.h"
+#include "net/http2/http2_constants.h"
+#include "net/http2/http2_constants_test_util.h"
+#include "net/http2/http2_structures.h"
+#include "net/http2/tools/http2_frame_builder.h"
+#include "net/http2/tools/random_decoder_test.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace net {
+namespace test {
+
+// Base class for tests of payload decoders. Below this there is a templated
+// sub-class that adds a bunch of type specific features.
+class PayloadDecoderBaseTest : public RandomDecoderTest {
+ protected:
+  PayloadDecoderBaseTest();
+
+  // Virtual functions to be implemented by the test classes for the individual
+  // payload decoders...
+
+  // Start decoding the payload.
+  virtual DecodeStatus StartDecodingPayload(DecodeBuffer* db) = 0;
+
+  // Resume decoding the payload.
+  virtual DecodeStatus ResumeDecodingPayload(DecodeBuffer* db) = 0;
+
+  // In support of ensuring that we're really accessing and updating the
+  // decoder, prepare the decoder by, for example, overwriting the decoder.
+  virtual void PreparePayloadDecoder() = 0;
+
+  // Get the listener to be inserted into the FrameDecoderState, ready for
+  // listening (e.g. reset if it is a FramePartsCollector).
+  virtual Http2FrameDecoderListener* PrepareListener() = 0;
+
+  // Record a frame header for use on each call to StartDecoding.
+  void set_frame_header(const Http2FrameHeader& header) {
+    EXPECT_EQ(0, InvalidFlagMaskForFrameType(header.type) & header.flags);
+    if (!frame_header_is_set_ || frame_header_ != header) {
+      VLOG(2) << "set_frame_header: " << frame_header_;
+    }
+    frame_header_ = header;
+    frame_header_is_set_ = true;
+  }
+
+  const Http2FrameHeader& frame_header() const {
+    CHECK(frame_header_is_set_);
+    return frame_header_;
+  }
+
+  FrameDecoderState* mutable_state() { return &frame_decoder_state_; }
+
+  // Randomize the payload decoder, sets the payload decoder's frame_header_,
+  // then start decoding the payload. Called by RandomDecoderTest. This method
+  // is final so that we can always perform certain actions when
+  // RandomDecoderTest starts the decoding of a payload, such as randomizing the
+  // the payload decoder, injecting the frame header and counting fast decoding
+  // cases. Sub-classes must implement StartDecodingPayload to perform their
+  // initial decoding of a frame's payload.
+  DecodeStatus StartDecoding(DecodeBuffer* db) final;
+
+  // Called by RandomDecoderTest. This method is final so that we can always
+  // perform certain actions when RandomDecoderTest calls it, such as counting
+  // slow decode cases. Sub-classes must implement ResumeDecodingPayload to
+  // continue decoding the frame's payload, which must not all be in one buffer.
+  DecodeStatus ResumeDecoding(DecodeBuffer* db) final;
+
+  // Given the specified payload (without the common frame header), decode
+  // it with several partitionings of the payload.
+  ::testing::AssertionResult DecodePayloadAndValidateSeveralWays(
+      base::StringPiece payload,
+      Validator validator);
+
+  // TODO(jamessynge): Add helper method for verifying these are both non-zero,
+  // and call the new method from tests that expect successful decoding.
+  void ResetDecodeSpeedCounters() {
+    fast_decode_count_ = 0;
+    slow_decode_count_ = 0;
+  }
+
+  // Count of payloads that are full decoded by StartDecodingPayload, or that
+  // an error was detected by StartDecodingPayload.
+  size_t fast_decode_count_ = 0;
+
+  // Count of payloads that require calling ResumeDecodingPayload in order to
+  // decode them completely (or to detect an error during decoding).
+  size_t slow_decode_count_ = 0;
+
+ private:
+  bool frame_header_is_set_ = false;
+  Http2FrameHeader frame_header_;
+  FrameDecoderState frame_decoder_state_;
+};
+
+// Base class for payload decoders of type Decoder, with corresponding test
+// peer of type DecoderPeer, and using class Listener as the implementation
+// of Http2FrameDecoderListenerInterface to be used during decoding.
+// Typically Listener is a sub-class of FramePartsCollector.
+// SupportedFrameType is set to false only for UnknownPayloadDecoder.
+template <class Decoder,
+          class DecoderPeer,
+          class Listener,
+          bool SupportedFrameType = true>
+class AbstractPayloadDecoderTest : public PayloadDecoderBaseTest {
+ public:
+  static bool SucceedingApproveSize(size_t size) { return true; }
+
+ protected:
+  // An ApproveSize function returns true to approve decoding the specified
+  // size of payload, else false to skip that size. Typically used for negative
+  // tests; for example, decoding a SETTINGS frame at all sizes except for
+  // multiples of 6.
+  typedef base::Callback<bool(size_t size)> ApproveSize;
+
+  AbstractPayloadDecoderTest() {}
+
+  // These tests are in setup rather than the constructor for two reasons:
+  // 1) Constructors are not allowed to fail, so gUnit documents that EXPECT_*
+  //    and ASSERT_* are not allowed in constructors, and should instead be in
+  //    SetUp if they are needed before the body of the test is executed.
+  // 2) To allow the sub-class constructor to make any desired modifications to
+  //    the DecoderPeer before these tests are executed; in particular,
+  //    UnknownPayloadDecoderPeer has not got a fixed frame type, but it is
+  //    instead set during the test's constructor.
+  void SetUp() override {
+    PayloadDecoderBaseTest::SetUp();
+
+    // Confirm that DecoderPeer et al returns sensible values. Using auto as the
+    // variable type so that no (narrowing) conversions take place that hide
+    // problems; i.e. if someone changes KnownFlagsMaskForFrameType so that it
+    // doesn't return a uint8, and has bits above the low-order 8 bits set, this
+    // bit of paranoia should detect the problem before we get too far.
+    auto frame_type = DecoderPeer::FrameType();
+    if (SupportedFrameType) {
+      EXPECT_TRUE(IsSupportedHttp2FrameType(frame_type)) << frame_type;
+    } else {
+      EXPECT_FALSE(IsSupportedHttp2FrameType(frame_type)) << frame_type;
+    }
+
+    auto known_flags = KnownFlagsMaskForFrameType(frame_type);
+    EXPECT_EQ(known_flags, known_flags & 0xff);
+
+    auto flags_to_avoid = DecoderPeer::FlagsAffectingPayloadDecoding();
+    EXPECT_EQ(flags_to_avoid, flags_to_avoid & known_flags);
+  }
+
+  void PreparePayloadDecoder() override {
+    payload_decoder_.~Decoder();
+    new (&payload_decoder_) Decoder;
+  }
+
+  Http2FrameDecoderListener* PrepareListener() override {
+    listener_.Reset();
+    return &listener_;
+  }
+
+  // Returns random flags, but only those valid for the frame type, yet not
+  // those that the DecoderPeer says will affect the decoding of the payload
+  // (e.g. the PRIORTY flag on a HEADERS frame or PADDED on DATA frames).
+  uint8_t RandFlags() {
+    return Random().Rand8() &
+           KnownFlagsMaskForFrameType(DecoderPeer::FrameType()) &
+           ~DecoderPeer::FlagsAffectingPayloadDecoding();
+  }
+
+  // Start decoding the payload.
+  DecodeStatus StartDecodingPayload(DecodeBuffer* db) override {
+    DVLOG(2) << "StartDecodingPayload, db->Remaining=" << db->Remaining();
+    return payload_decoder_.StartDecodingPayload(mutable_state(), db);
+  }
+
+  // Resume decoding the payload.
+  DecodeStatus ResumeDecodingPayload(DecodeBuffer* db) override {
+    DVLOG(2) << "ResumeDecodingPayload, db->Remaining=" << db->Remaining();
+    return payload_decoder_.ResumeDecodingPayload(mutable_state(), db);
+  }
+
+  // Wrap |validator| in another one which will check that we've reached the
+  // expected state of kDecodeError with OnFrameSizeError having been called by
+  AssertionResult ValidatorForDecodePayloadAndValidateSeveralWays(
+      const FrameParts& expected) {
+    VERIFY_FALSE(listener_.IsInProgress());
+    VERIFY_EQ(1u, listener_.size());
+    VERIFY_AND_RETURN_SUCCESS(expected.VerifyEquals(*listener_.frame(0)));
+  }
+
+  // Decode one frame's payload and confirm that the listener recorded the
+  // expected FrameParts instance, and only FrameParts instance. The payload
+  // will be decoded several times with different partitionings of the payload,
+  // and after each the validator will be called.
+  AssertionResult DecodePayloadAndValidateSeveralWays(
+      base::StringPiece payload,
+      const FrameParts& expected) {
+    return PayloadDecoderBaseTest::DecodePayloadAndValidateSeveralWays(
+        payload, this->ValidateDoneAndEmpty(base::Bind(
+                     &AbstractPayloadDecoderTest::
+                         ValidatorForDecodePayloadAndValidateSeveralWays,
+                     base::Unretained(this), base::ConstRef(expected))));
+  }
+
+  // Wrap |validator| in another one which will check that we've reached the
+  // expected state of kDecodeError with OnFrameSizeError having been called by
+  // the payload decoder.
+  AssertionResult ValidatorForVerifyDetectsFrameSizeError(
+      const Http2FrameHeader& header,
+      const Validator& validator,
+      const DecodeBuffer& input,
+      DecodeStatus status) {
+    DVLOG(2) << "VerifyDetectsFrameSizeError validator; status=" << status
+             << "; input.Remaining=" << input.Remaining();
+    VERIFY_EQ(DecodeStatus::kDecodeError, status);
+    VERIFY_FALSE(listener_.IsInProgress());
+    VERIFY_EQ(1u, listener_.size());
+    const FrameParts* frame = listener_.frame(0);
+    VERIFY_EQ(header, frame->frame_header);
+    VERIFY_TRUE(frame->has_frame_size_error);
+    // Verify did not get OnPaddingTooLong, as we should only ever produce
+    // one of these two errors for a single frame.
+    VERIFY_FALSE(frame->opt_missing_length);
+    return validator.Run(input, status);
+  }
+
+  // Decode one frame's payload, expecting that the final status will be
+  // kDecodeError, and that OnFrameSizeError will have been called on the
+  // listener. The payload will be decoded several times with different
+  // partitionings of the payload. The type WrappedValidator is either
+  // RandomDecoderTest::Validator, RandomDecoderTest::NoArgValidator or
+  // std::nullptr_t (not extra validation).
+  template <typename WrappedValidator>
+  ::testing::AssertionResult VerifyDetectsFrameSizeError(
+      base::StringPiece payload,
+      const Http2FrameHeader& header,
+      WrappedValidator wrapped_validator) {
+    set_frame_header(header);
+    // If wrapped_validator is not a RandomDecoderTest::Validator, make it so.
+    Validator validator = this->ToValidator(wrapped_validator);
+    VERIFY_AND_RETURN_SUCCESS(
+        PayloadDecoderBaseTest::DecodePayloadAndValidateSeveralWays(
+            payload, base::Bind(&AbstractPayloadDecoderTest::
+                                    ValidatorForVerifyDetectsFrameSizeError,
+                                base::Unretained(this), base::ConstRef(header),
+                                base::ConstRef(validator))));
+  }
+
+  // Confirm that we get OnFrameSizeError when trying to decode unpadded_payload
+  // at all sizes from zero to unpadded_payload.size(), except those sizes not
+  // approved by approve_size.
+  // If total_pad_length is greater than zero, then that amount of padding
+  // is added to the payload (including the Pad Length field).
+  // The flags will be required_flags, PADDED if total_pad_length > 0, and some
+  // randomly selected flag bits not excluded by FlagsAffectingPayloadDecoding.
+  ::testing::AssertionResult VerifyDetectsMultipleFrameSizeErrors(
+      uint8_t required_flags,
+      base::StringPiece unpadded_payload,
+      ApproveSize approve_size,
+      int total_pad_length) {
+    // required_flags should come from those that are defined for the frame
+    // type AND are those that affect the decoding of the payload (otherwise,
+    // the flag shouldn't be required).
+    Http2FrameType frame_type = DecoderPeer::FrameType();
+    VERIFY_EQ(required_flags,
+              required_flags & KnownFlagsMaskForFrameType(frame_type));
+    VERIFY_EQ(required_flags,
+              required_flags & DecoderPeer::FlagsAffectingPayloadDecoding());
+
+    if (0 != (Http2FrameFlag::FLAG_PADDED &
+              KnownFlagsMaskForFrameType(frame_type))) {
+      // Frame type supports padding.
+      if (total_pad_length == 0) {
+        required_flags &= ~Http2FrameFlag::FLAG_PADDED;
+      } else {
+        required_flags |= Http2FrameFlag::FLAG_PADDED;
+      }
+    } else {
+      VERIFY_EQ(0, total_pad_length);
+    }
+
+    bool validated = false;
+    for (size_t real_payload_size = 0;
+         real_payload_size <= unpadded_payload.size(); ++real_payload_size) {
+      if (!approve_size.Run(real_payload_size)) {
+        continue;
+      }
+      VLOG(1) << "real_payload_size=" << real_payload_size;
+      uint8_t flags = required_flags | RandFlags();
+      Http2FrameBuilder fb;
+      if (total_pad_length > 0) {
+        // total_pad_length_ includes the size of the Pad Length field, and thus
+        // ranges from 0 (no PADDED flag) to 256 (Pad Length == 255).
+        fb.AppendUInt8(total_pad_length - 1);
+      }
+      // Append a subset of the unpadded_payload, which the decoder should
+      // determine is not a valid amount.
+      fb.Append(unpadded_payload.substr(0, real_payload_size));
+      if (total_pad_length > 0) {
+        fb.AppendZeroes(total_pad_length - 1);
+      }
+      // We choose a random stream id because the payload decoders aren't
+      // checking stream ids.
+      uint32_t stream_id = RandStreamId();
+      Http2FrameHeader header(fb.size(), frame_type, flags, stream_id);
+      VERIFY_SUCCESS(VerifyDetectsFrameSizeError(
+          fb.buffer(), header, base::Bind(&SucceedingValidator)));
+      validated = true;
+    }
+    VERIFY_TRUE(validated);
+    return ::testing::AssertionSuccess();
+  }
+
+  // As above, but for frames without padding.
+  ::testing::AssertionResult VerifyDetectsFrameSizeError(
+      uint8_t required_flags,
+      base::StringPiece unpadded_payload,
+      ApproveSize approve_size) {
+    Http2FrameType frame_type = DecoderPeer::FrameType();
+    uint8_t known_flags = KnownFlagsMaskForFrameType(frame_type);
+    VERIFY_EQ(0, known_flags & Http2FrameFlag::FLAG_PADDED);
+    VERIFY_EQ(0, required_flags & Http2FrameFlag::FLAG_PADDED);
+    VERIFY_AND_RETURN_SUCCESS(VerifyDetectsMultipleFrameSizeErrors(
+        required_flags, unpadded_payload, approve_size, 0));
+  }
+
+  Listener listener_;
+  union {
+    // Confirm at compile time that Decoder can be in an anonymous union,
+    // i.e. complain loudly if Decoder has members that prevent this, as it
+    // becomes annoying and possibly difficult to deal with non-anonymous
+    // unions and such union members.
+    Decoder payload_decoder_;
+  };
+};
+
+// A base class for tests parameterized by the total number of bytes of
+// padding, including the Pad Length field (i.e. a total_pad_length of 0
+// means unpadded as there is then no room for the Pad Length field).
+// The frame type must support padding.
+template <class Decoder, class DecoderPeer, class Listener>
+class AbstractPaddablePayloadDecoderTest
+    : public AbstractPayloadDecoderTest<Decoder, DecoderPeer, Listener>,
+      public ::testing::WithParamInterface<int> {
+  typedef AbstractPayloadDecoderTest<Decoder, DecoderPeer, Listener> Base;
+
+ protected:
+  using Base::Random;
+  using Base::RandStreamId;
+  using Base::set_frame_header;
+  using Base::listener_;
+  typedef typename Base::Validator Validator;
+
+  AbstractPaddablePayloadDecoderTest() : total_pad_length_(GetParam()) {
+    LOG(INFO) << "total_pad_length_ = " << total_pad_length_;
+  }
+
+  // Note that total_pad_length_ includes the size of the Pad Length field,
+  // and thus ranges from 0 (no PADDED flag) to 256 (Pad Length == 255).
+  bool IsPadded() const { return total_pad_length_ > 0; }
+
+  // Value of the Pad Length field. Only call if IsPadded.
+  size_t pad_length() const {
+    EXPECT_TRUE(IsPadded());
+    return total_pad_length_ - 1;
+  }
+
+  // Clear the frame builder and add the Pad Length field if appropriate.
+  void Reset() {
+    frame_builder_ = Http2FrameBuilder();
+    if (IsPadded()) {
+      frame_builder_.AppendUInt8(pad_length());
+    }
+  }
+
+  void MaybeAppendTrailingPadding() {
+    if (IsPadded()) {
+      frame_builder_.AppendZeroes(pad_length());
+    }
+  }
+
+  uint8_t RandFlags() {
+    uint8_t flags = Base::RandFlags();
+    if (IsPadded()) {
+      flags |= Http2FrameFlag::FLAG_PADDED;
+    } else {
+      flags &= ~Http2FrameFlag::FLAG_PADDED;
+    }
+    return flags;
+  }
+
+  static ::testing::AssertionResult ValidatorForVerifyDetectsPaddingTooLong(
+      const Http2FrameHeader& header,
+      int expected_missing_length,
+      const Listener& listener,
+      const DecodeBuffer& input,
+      DecodeStatus status) {
+    VERIFY_EQ(DecodeStatus::kDecodeError, status);
+    VERIFY_FALSE(listener.IsInProgress());
+    VERIFY_EQ(1u, listener.size());
+    const FrameParts* frame = listener.frame(0);
+    VERIFY_EQ(header, frame->frame_header);
+    VERIFY_TRUE(frame->opt_missing_length);
+    VERIFY_EQ(expected_missing_length, frame->opt_missing_length.value());
+    // Verify did not get OnFrameSizeError.
+    VERIFY_FALSE(frame->has_frame_size_error);
+    return ::testing::AssertionSuccess();
+  }
+
+  // Verify that we get OnPaddingTooLong when decoding payload, and that the
+  // amount of missing padding is as specified. header.IsPadded must be true,
+  // and the payload must be empty or the PadLength field must be too large.
+  ::testing::AssertionResult VerifyDetectsPaddingTooLong(
+      base::StringPiece payload,
+      const Http2FrameHeader& header,
+      int expected_missing_length) {
+    set_frame_header(header);
+    auto& listener = listener_;
+    VERIFY_AND_RETURN_SUCCESS(
+        PayloadDecoderBaseTest::DecodePayloadAndValidateSeveralWays(
+            payload, base::Bind(&AbstractPaddablePayloadDecoderTest::
+                                    ValidatorForVerifyDetectsPaddingTooLong,
+                                header, expected_missing_length,
+                                base::ConstRef(listener))));
+  }
+
+  // Verifies that we get OnPaddingTooLong for a padded frame payload whose
+  // (randomly selected) payload length is less than total_pad_length_.
+  // Flags will be selected at random, except PADDED will be set and
+  // flags_to_avoid will not be set. The stream id is selected at random.
+  ::testing::AssertionResult VerifyDetectsPaddingTooLong() {
+    uint8_t flags = RandFlags() | Http2FrameFlag::FLAG_PADDED;
+
+    // Create an all padding payload for total_pad_length_.
+    int payload_length = 0;
+    Http2FrameBuilder fb;
+    if (IsPadded()) {
+      fb.AppendUInt8(pad_length());
+      fb.AppendZeroes(pad_length());
+      VLOG(1) << "fb.size=" << fb.size();
+      // Pick a random length for the payload that is shorter than neccesary.
+      payload_length = Random().Rand32() % fb.size();
+    }
+
+    VLOG(1) << "payload_length=" << payload_length;
+    std::string payload = fb.buffer().substr(0, payload_length);
+
+    // The missing length is the amount we cut off the end, unless
+    // payload_length is zero, in which case the decoder knows only that 1
+    // byte, the Pad Length field, is missing.
+    int missing_length = payload_length == 0 ? 1 : fb.size() - payload_length;
+    VLOG(1) << "missing_length=" << missing_length;
+
+    const Http2FrameHeader header(payload_length, DecoderPeer::FrameType(),
+                                  flags, RandStreamId());
+    VERIFY_AND_RETURN_SUCCESS(
+        VerifyDetectsPaddingTooLong(payload, header, missing_length));
+  }
+
+  // total_pad_length_ includes the size of the Pad Length field, and thus
+  // ranges from 0 (no PADDED flag) to 256 (Pad Length == 255).
+  const size_t total_pad_length_;
+  Http2FrameBuilder frame_builder_;
+};
+
+}  // namespace test
+}  // namespace net
+
+#endif  // NET_HTTP2_DECODER_PAYLOAD_DECODERS_PAYLOAD_DECODER_BASE_TEST_UTIL_H_