| // Copyright 2020 The Fuchsia 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 <zircon/assert.h> |
| #include <zircon/errors.h> |
| |
| #include <cstdint> |
| #include <cstring> |
| #include <memory> |
| #include <vector> |
| |
| #include <fuzzer/FuzzedDataProvider.h> |
| |
| #include "src/storage/blobfs/compression-settings.h" |
| #include "src/storage/blobfs/compression/zstd-seekable.h" |
| |
| // Compression/decompression symmetry fuzzer for zstd seekable. The fuzzer compresses and then |
| // decompresses part of a seekable zstd archive. This fuzzer uses its input to: |
| // 1. Select the size of the read (in uncompressed space) during decompression; |
| // 2. Select the offset for the read (in uncompressed space) during decompression; |
| // 3. Determine the contents of the archive (in incumpressed space) prior to compression. |
| extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) { |
| FuzzedDataProvider provider(data, size); |
| size_t uncompressed_size = provider.ConsumeIntegral<size_t>(); |
| size_t offset = provider.ConsumeIntegral<size_t>(); |
| const size_t data_size = provider.remaining_bytes(); |
| std::vector<uint8_t> src_buf = provider.ConsumeRemainingBytes<uint8_t>(); |
| const size_t max_compressed_size = blobfs::ZSTDSeekableCompressor::BufferMax(data_size); |
| std::vector<uint8_t> compressed_buf(max_compressed_size); |
| |
| // Compress data. |
| std::unique_ptr<blobfs::ZSTDSeekableCompressor> compressor; |
| blobfs::CompressionSettings settings = {.compression_algorithm = |
| blobfs::CompressionAlgorithm::ZSTD_SEEKABLE}; |
| ZX_ASSERT(blobfs::ZSTDSeekableCompressor::Create(settings, data_size, compressed_buf.data(), |
| max_compressed_size, &compressor) == ZX_OK); |
| ZX_ASSERT(compressor->Update(data, data_size) == ZX_OK); |
| ZX_ASSERT(compressor->End() == ZX_OK); |
| |
| // Select size and offset for decompression. |
| uncompressed_size %= data_size + 1; |
| offset %= data_size - uncompressed_size + 1; |
| |
| // Store initial `uncompressed_size` to check for complete read. |
| const size_t initial_uncompressed_size = uncompressed_size; |
| |
| // Decompress from uncompressed space `offset` through `offset + uncompressed_size` into |
| // `uncompressed_buf`. |
| std::vector<uint8_t> uncompressed_buf(initial_uncompressed_size); |
| blobfs::ZSTDSeekableDecompressor decompressor; |
| ZX_ASSERT(decompressor.DecompressRange(uncompressed_buf.data(), &uncompressed_size, |
| compressed_buf.data(), compressor->Size(), offset) == 0); |
| |
| // Verify correctness of read. |
| ZX_ASSERT(std::memcmp(data + offset, uncompressed_buf.data(), uncompressed_size) == 0); |
| |
| // Verify size of read. |
| ZX_ASSERT(initial_uncompressed_size == uncompressed_size); |
| |
| return 0; |
| } |