| // 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 "http2/hpack/varint/hpack_varint_decoder.h" |
| |
| // Test HpackVarintDecoder against data encoded via HpackBlockBuilder, |
| // which uses HpackVarintEncoder under the hood. |
| |
| #include <stddef.h> |
| |
| #include <iterator> |
| #include <set> |
| #include <vector> |
| |
| #include "absl/strings/str_cat.h" |
| #include "absl/strings/string_view.h" |
| #include "http2/hpack/tools/hpack_block_builder.h" |
| #include "http2/platform/api/http2_logging.h" |
| #include "http2/platform/api/http2_string_utils.h" |
| #include "http2/tools/random_decoder_test.h" |
| #include "common/platform/api/quiche_test.h" |
| |
| using ::testing::AssertionFailure; |
| using ::testing::AssertionSuccess; |
| |
| namespace http2 { |
| namespace test { |
| namespace { |
| |
| // Returns the highest value with the specified number of extension bytes |
| // and the specified prefix length (bits). |
| uint64_t HiValueOfExtensionBytes(uint32_t extension_bytes, |
| uint32_t prefix_length) { |
| return (1 << prefix_length) - 2 + |
| (extension_bytes == 0 ? 0 : (1LLU << (extension_bytes * 7))); |
| } |
| |
| class HpackVarintRoundTripTest : public RandomDecoderTest { |
| protected: |
| HpackVarintRoundTripTest() : prefix_length_(0) {} |
| |
| DecodeStatus StartDecoding(DecodeBuffer* b) override { |
| QUICHE_CHECK_LT(0u, b->Remaining()); |
| uint8_t prefix = b->DecodeUInt8(); |
| return decoder_.Start(prefix, prefix_length_, b); |
| } |
| |
| DecodeStatus ResumeDecoding(DecodeBuffer* b) override { |
| return decoder_.Resume(b); |
| } |
| |
| void DecodeSeveralWays(uint64_t expected_value, uint32_t expected_offset) { |
| // The validator is called after each of the several times that the input |
| // DecodeBuffer is decoded, each with a different segmentation of the input. |
| // Validate that decoder_.value() matches the expected value. |
| Validator validator = [expected_value, this]( |
| const DecodeBuffer& /*db*/, |
| DecodeStatus /*status*/) -> AssertionResult { |
| if (decoder_.value() != expected_value) { |
| return AssertionFailure() |
| << "Value doesn't match expected: " << decoder_.value() |
| << " != " << expected_value; |
| } |
| return AssertionSuccess(); |
| }; |
| |
| // First validate that decoding is done and that we've advanced the cursor |
| // the expected amount. |
| validator = ValidateDoneAndOffset(expected_offset, validator); |
| |
| // StartDecoding, above, requires the DecodeBuffer be non-empty so that it |
| // can call Start with the prefix byte. |
| bool return_non_zero_on_first = true; |
| |
| DecodeBuffer b(buffer_); |
| EXPECT_TRUE( |
| DecodeAndValidateSeveralWays(&b, return_non_zero_on_first, validator)); |
| |
| EXPECT_EQ(expected_value, decoder_.value()); |
| EXPECT_EQ(expected_offset, b.Offset()); |
| } |
| |
| void EncodeNoRandom(uint64_t value, uint8_t prefix_length) { |
| QUICHE_DCHECK_LE(3, prefix_length); |
| QUICHE_DCHECK_LE(prefix_length, 8); |
| prefix_length_ = prefix_length; |
| |
| HpackBlockBuilder bb; |
| bb.AppendHighBitsAndVarint(0, prefix_length_, value); |
| buffer_ = bb.buffer(); |
| ASSERT_LT(0u, buffer_.size()); |
| |
| const uint8_t prefix_mask = (1 << prefix_length_) - 1; |
| ASSERT_EQ(static_cast<uint8_t>(buffer_[0]), |
| static_cast<uint8_t>(buffer_[0]) & prefix_mask); |
| } |
| |
| void Encode(uint64_t value, uint8_t prefix_length) { |
| EncodeNoRandom(value, prefix_length); |
| // Add some random bits to the prefix (the first byte) above the mask. |
| uint8_t prefix = buffer_[0]; |
| buffer_[0] = prefix | (Random().Rand8() << prefix_length); |
| const uint8_t prefix_mask = (1 << prefix_length_) - 1; |
| ASSERT_EQ(prefix, buffer_[0] & prefix_mask); |
| } |
| |
| // This is really a test of HpackBlockBuilder, making sure that the input to |
| // HpackVarintDecoder is as expected, which also acts as confirmation that |
| // my thinking about the encodings being used by the tests, i.e. cover the |
| // range desired. |
| void ValidateEncoding(uint64_t value, |
| uint64_t minimum, |
| uint64_t maximum, |
| size_t expected_bytes) { |
| ASSERT_EQ(expected_bytes, buffer_.size()); |
| if (expected_bytes > 1) { |
| const uint8_t prefix_mask = (1 << prefix_length_) - 1; |
| EXPECT_EQ(prefix_mask, buffer_[0] & prefix_mask); |
| size_t last = expected_bytes - 1; |
| for (size_t ndx = 1; ndx < last; ++ndx) { |
| // Before the last extension byte, we expect the high-bit set. |
| uint8_t byte = buffer_[ndx]; |
| if (value == minimum) { |
| EXPECT_EQ(0x80, byte) << "ndx=" << ndx; |
| } else if (value == maximum) { |
| if (expected_bytes < 11) { |
| EXPECT_EQ(0xff, byte) << "ndx=" << ndx; |
| } |
| } else { |
| EXPECT_EQ(0x80, byte & 0x80) << "ndx=" << ndx; |
| } |
| } |
| // The last extension byte should not have the high-bit set. |
| uint8_t byte = buffer_[last]; |
| if (value == minimum) { |
| if (expected_bytes == 2) { |
| EXPECT_EQ(0x00, byte); |
| } else { |
| EXPECT_EQ(0x01, byte); |
| } |
| } else if (value == maximum) { |
| if (expected_bytes < 11) { |
| EXPECT_EQ(0x7f, byte); |
| } |
| } else { |
| EXPECT_EQ(0x00, byte & 0x80); |
| } |
| } else { |
| const uint8_t prefix_mask = (1 << prefix_length_) - 1; |
| EXPECT_EQ(value, static_cast<uint32_t>(buffer_[0] & prefix_mask)); |
| EXPECT_LT(value, prefix_mask); |
| } |
| } |
| |
| void EncodeAndDecodeValues(const std::set<uint64_t>& values, |
| uint8_t prefix_length, |
| size_t expected_bytes) { |
| QUICHE_CHECK(!values.empty()); |
| const uint64_t minimum = *values.begin(); |
| const uint64_t maximum = *values.rbegin(); |
| for (const uint64_t value : values) { |
| Encode(value, prefix_length); // Sets buffer_. |
| |
| std::string msg = absl::StrCat("value=", value, " (0x", Http2Hex(value), |
| "), prefix_length=", prefix_length, |
| ", expected_bytes=", expected_bytes, "\n", |
| Http2HexDump(buffer_)); |
| |
| if (value == minimum) { |
| HTTP2_LOG(INFO) << "Checking minimum; " << msg; |
| } else if (value == maximum) { |
| HTTP2_LOG(INFO) << "Checking maximum; " << msg; |
| } |
| |
| SCOPED_TRACE(msg); |
| ValidateEncoding(value, minimum, maximum, expected_bytes); |
| DecodeSeveralWays(value, expected_bytes); |
| |
| // Append some random data to the end of buffer_ and repeat. That random |
| // data should be ignored. |
| buffer_.append(Random().RandString(1 + Random().Uniform(10))); |
| DecodeSeveralWays(value, expected_bytes); |
| |
| // If possible, add extension bytes that don't change the value. |
| if (1 < expected_bytes) { |
| buffer_.resize(expected_bytes); |
| for (uint8_t total_bytes = expected_bytes + 1; total_bytes <= 6; |
| ++total_bytes) { |
| // Mark the current last byte as not being the last one. |
| EXPECT_EQ(0x00, 0x80 & buffer_.back()); |
| buffer_.back() |= 0x80; |
| buffer_.push_back('\0'); |
| DecodeSeveralWays(value, total_bytes); |
| } |
| } |
| } |
| } |
| |
| // Encode values (all or some of it) in [start, start+range). Check |
| // that |start| is the smallest value and |start+range-1| is the largest value |
| // corresponding to |expected_bytes|, except if |expected_bytes| is maximal. |
| void EncodeAndDecodeValuesInRange(uint64_t start, |
| uint64_t range, |
| uint8_t prefix_length, |
| size_t expected_bytes) { |
| const uint8_t prefix_mask = (1 << prefix_length) - 1; |
| const uint64_t beyond = start + range; |
| |
| HTTP2_LOG(INFO) |
| << "############################################################"; |
| HTTP2_LOG(INFO) << "prefix_length=" << static_cast<int>(prefix_length); |
| HTTP2_LOG(INFO) << "prefix_mask=" << std::hex |
| << static_cast<int>(prefix_mask); |
| HTTP2_LOG(INFO) << "start=" << start << " (" << std::hex << start << ")"; |
| HTTP2_LOG(INFO) << "range=" << range << " (" << std::hex << range << ")"; |
| HTTP2_LOG(INFO) << "beyond=" << beyond << " (" << std::hex << beyond << ")"; |
| HTTP2_LOG(INFO) << "expected_bytes=" << expected_bytes; |
| |
| if (expected_bytes < 11) { |
| // Confirm the claim that beyond requires more bytes. |
| Encode(beyond, prefix_length); |
| EXPECT_EQ(expected_bytes + 1, buffer_.size()) << Http2HexDump(buffer_); |
| } |
| |
| std::set<uint64_t> values; |
| if (range < 200) { |
| // Select all values in the range. |
| for (uint64_t offset = 0; offset < range; ++offset) { |
| values.insert(start + offset); |
| } |
| } else { |
| // Select some values in this range, including the minimum and maximum |
| // values that require exactly |expected_bytes| extension bytes. |
| values.insert({start, start + 1, beyond - 2, beyond - 1}); |
| while (values.size() < 100) { |
| values.insert(Random().UniformInRange(start, beyond - 1)); |
| } |
| } |
| |
| EncodeAndDecodeValues(values, prefix_length, expected_bytes); |
| } |
| |
| HpackVarintDecoder decoder_; |
| std::string buffer_; |
| uint8_t prefix_length_; |
| }; |
| |
| // To help me and future debuggers of varint encodings, this HTTP2_LOGs out the |
| // transition points where a new extension byte is added. |
| TEST_F(HpackVarintRoundTripTest, Encode) { |
| for (int prefix_length = 3; prefix_length <= 8; ++prefix_length) { |
| const uint64_t a = HiValueOfExtensionBytes(0, prefix_length); |
| const uint64_t b = HiValueOfExtensionBytes(1, prefix_length); |
| const uint64_t c = HiValueOfExtensionBytes(2, prefix_length); |
| const uint64_t d = HiValueOfExtensionBytes(3, prefix_length); |
| const uint64_t e = HiValueOfExtensionBytes(4, prefix_length); |
| const uint64_t f = HiValueOfExtensionBytes(5, prefix_length); |
| const uint64_t g = HiValueOfExtensionBytes(6, prefix_length); |
| const uint64_t h = HiValueOfExtensionBytes(7, prefix_length); |
| const uint64_t i = HiValueOfExtensionBytes(8, prefix_length); |
| const uint64_t j = HiValueOfExtensionBytes(9, prefix_length); |
| |
| HTTP2_LOG(INFO) |
| << "############################################################"; |
| HTTP2_LOG(INFO) << "prefix_length=" << prefix_length << " a=" << a |
| << " b=" << b << " c=" << c << " d=" << d |
| << " e=" << e << " f=" << f << " g=" << g |
| << " h=" << h << " i=" << i << " j=" << j; |
| |
| std::vector<uint64_t> values = { |
| 0, 1, // Force line break. |
| a - 1, a, a + 1, a + 2, a + 3, // Force line break. |
| b - 1, b, b + 1, b + 2, b + 3, // Force line break. |
| c - 1, c, c + 1, c + 2, c + 3, // Force line break. |
| d - 1, d, d + 1, d + 2, d + 3, // Force line break. |
| e - 1, e, e + 1, e + 2, e + 3, // Force line break. |
| f - 1, f, f + 1, f + 2, f + 3, // Force line break. |
| g - 1, g, g + 1, g + 2, g + 3, // Force line break. |
| h - 1, h, h + 1, h + 2, h + 3, // Force line break. |
| i - 1, i, i + 1, i + 2, i + 3, // Force line break. |
| j - 1, j, j + 1, j + 2, j + 3, // Force line break. |
| }; |
| |
| for (uint64_t value : values) { |
| EncodeNoRandom(value, prefix_length); |
| std::string dump = Http2HexDump(buffer_); |
| HTTP2_LOG(INFO) << Http2StringPrintf("%10llu %0#18x ", value, value) |
| << Http2HexDump(buffer_).substr(7); |
| } |
| } |
| } |
| |
| TEST_F(HpackVarintRoundTripTest, FromSpec1337) { |
| DecodeBuffer b(absl::string_view("\x1f\x9a\x0a")); |
| uint32_t prefix_length = 5; |
| uint8_t p = b.DecodeUInt8(); |
| EXPECT_EQ(1u, b.Offset()); |
| EXPECT_EQ(DecodeStatus::kDecodeDone, decoder_.Start(p, prefix_length, &b)); |
| EXPECT_EQ(3u, b.Offset()); |
| EXPECT_EQ(1337u, decoder_.value()); |
| |
| EncodeNoRandom(1337, prefix_length); |
| EXPECT_EQ(3u, buffer_.size()); |
| EXPECT_EQ('\x1f', buffer_[0]); |
| EXPECT_EQ('\x9a', buffer_[1]); |
| EXPECT_EQ('\x0a', buffer_[2]); |
| } |
| |
| // Test all the values that fit into the prefix (one less than the mask). |
| TEST_F(HpackVarintRoundTripTest, ValidatePrefixOnly) { |
| for (int prefix_length = 3; prefix_length <= 8; ++prefix_length) { |
| const uint8_t prefix_mask = (1 << prefix_length) - 1; |
| EncodeAndDecodeValuesInRange(0, prefix_mask, prefix_length, 1); |
| } |
| } |
| |
| // Test all values that require exactly 1 extension byte. |
| TEST_F(HpackVarintRoundTripTest, ValidateOneExtensionByte) { |
| for (int prefix_length = 3; prefix_length <= 8; ++prefix_length) { |
| const uint64_t start = HiValueOfExtensionBytes(0, prefix_length) + 1; |
| EncodeAndDecodeValuesInRange(start, 128, prefix_length, 2); |
| } |
| } |
| |
| // Test *some* values that require exactly 2 extension bytes. |
| TEST_F(HpackVarintRoundTripTest, ValidateTwoExtensionBytes) { |
| for (int prefix_length = 3; prefix_length <= 8; ++prefix_length) { |
| const uint64_t start = HiValueOfExtensionBytes(1, prefix_length) + 1; |
| const uint64_t range = 127 << 7; |
| |
| EncodeAndDecodeValuesInRange(start, range, prefix_length, 3); |
| } |
| } |
| |
| // Test *some* values that require 3 extension bytes. |
| TEST_F(HpackVarintRoundTripTest, ValidateThreeExtensionBytes) { |
| for (int prefix_length = 3; prefix_length <= 8; ++prefix_length) { |
| const uint64_t start = HiValueOfExtensionBytes(2, prefix_length) + 1; |
| const uint64_t range = 127 << 14; |
| |
| EncodeAndDecodeValuesInRange(start, range, prefix_length, 4); |
| } |
| } |
| |
| // Test *some* values that require 4 extension bytes. |
| TEST_F(HpackVarintRoundTripTest, ValidateFourExtensionBytes) { |
| for (int prefix_length = 3; prefix_length <= 8; ++prefix_length) { |
| const uint64_t start = HiValueOfExtensionBytes(3, prefix_length) + 1; |
| const uint64_t range = 127 << 21; |
| |
| EncodeAndDecodeValuesInRange(start, range, prefix_length, 5); |
| } |
| } |
| |
| // Test *some* values that require 5 extension bytes. |
| TEST_F(HpackVarintRoundTripTest, ValidateFiveExtensionBytes) { |
| for (int prefix_length = 3; prefix_length <= 8; ++prefix_length) { |
| const uint64_t start = HiValueOfExtensionBytes(4, prefix_length) + 1; |
| const uint64_t range = 127llu << 28; |
| |
| EncodeAndDecodeValuesInRange(start, range, prefix_length, 6); |
| } |
| } |
| |
| // Test *some* values that require 6 extension bytes. |
| TEST_F(HpackVarintRoundTripTest, ValidateSixExtensionBytes) { |
| for (int prefix_length = 3; prefix_length <= 8; ++prefix_length) { |
| const uint64_t start = HiValueOfExtensionBytes(5, prefix_length) + 1; |
| const uint64_t range = 127llu << 35; |
| |
| EncodeAndDecodeValuesInRange(start, range, prefix_length, 7); |
| } |
| } |
| |
| // Test *some* values that require 7 extension bytes. |
| TEST_F(HpackVarintRoundTripTest, ValidateSevenExtensionBytes) { |
| for (int prefix_length = 3; prefix_length <= 8; ++prefix_length) { |
| const uint64_t start = HiValueOfExtensionBytes(6, prefix_length) + 1; |
| const uint64_t range = 127llu << 42; |
| |
| EncodeAndDecodeValuesInRange(start, range, prefix_length, 8); |
| } |
| } |
| |
| // Test *some* values that require 8 extension bytes. |
| TEST_F(HpackVarintRoundTripTest, ValidateEightExtensionBytes) { |
| for (int prefix_length = 3; prefix_length <= 8; ++prefix_length) { |
| const uint64_t start = HiValueOfExtensionBytes(7, prefix_length) + 1; |
| const uint64_t range = 127llu << 49; |
| |
| EncodeAndDecodeValuesInRange(start, range, prefix_length, 9); |
| } |
| } |
| |
| // Test *some* values that require 9 extension bytes. |
| TEST_F(HpackVarintRoundTripTest, ValidateNineExtensionBytes) { |
| for (int prefix_length = 3; prefix_length <= 8; ++prefix_length) { |
| const uint64_t start = HiValueOfExtensionBytes(8, prefix_length) + 1; |
| const uint64_t range = 127llu << 56; |
| |
| EncodeAndDecodeValuesInRange(start, range, prefix_length, 10); |
| } |
| } |
| |
| // Test *some* values that require 10 extension bytes. |
| TEST_F(HpackVarintRoundTripTest, ValidateTenExtensionBytes) { |
| for (int prefix_length = 3; prefix_length <= 8; ++prefix_length) { |
| const uint64_t start = HiValueOfExtensionBytes(9, prefix_length) + 1; |
| const uint64_t range = std::numeric_limits<uint64_t>::max() - start; |
| |
| EncodeAndDecodeValuesInRange(start, range, prefix_length, 11); |
| } |
| } |
| |
| } // namespace |
| } // namespace test |
| } // namespace http2 |