|  | // | 
|  | // Copyright (C) 2021 The Android Open Source Project | 
|  | // | 
|  | // Licensed under the Apache License, Version 2.0 (the "License"); | 
|  | // you may not use this file except in compliance with the License. | 
|  | // You may obtain a copy of the License at | 
|  | // | 
|  | //      http://www.apache.org/licenses/LICENSE-2.0 | 
|  | // | 
|  | // Unless required by applicable law or agreed to in writing, software | 
|  | // distributed under the License is distributed on an "AS IS" BASIS, | 
|  | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | 
|  | // See the License for the specific language governing permissions and | 
|  | // limitations under the License. | 
|  | // | 
|  |  | 
|  | #include "lz4diff.h" | 
|  | #include "lz4diff_compress.h" | 
|  |  | 
|  | #include <bsdiff/bsdiff.h> | 
|  | #include <bsdiff/constants.h> | 
|  | #include <bsdiff/patch_writer_factory.h> | 
|  | #include <bsdiff/patch_writer.h> | 
|  | #include <puffin/common.h> | 
|  | #include <puffin/puffdiff.h> | 
|  | #include <lz4.h> | 
|  | #include <lz4hc.h> | 
|  |  | 
|  | #include "update_engine/common/utils.h" | 
|  | #include "update_engine/common/hash_calculator.h" | 
|  | #include "update_engine/payload_generator/deflate_utils.h" | 
|  | #include "update_engine/payload_generator/delta_diff_generator.h" | 
|  | #include "lz4diff/lz4diff.pb.h" | 
|  | #include "lz4diff_format.h" | 
|  |  | 
|  | namespace chromeos_update_engine { | 
|  |  | 
|  | bool StoreDstCompressedFileInfo(std::string_view recompressed_blob, | 
|  | std::string_view target_blob, | 
|  | const CompressedFile& dst_file_info, | 
|  | Lz4diffHeader* output) { | 
|  | *output->mutable_dst_info()->mutable_algo() = dst_file_info.algo; | 
|  | output->mutable_dst_info()->set_zero_padding_enabled( | 
|  | dst_file_info.zero_padding_enabled); | 
|  | const auto& block_info = dst_file_info.blocks; | 
|  | auto& dst_block_info = *output->mutable_dst_info()->mutable_block_info(); | 
|  | dst_block_info.Clear(); | 
|  | size_t offset = 0; | 
|  | for (const auto& block : block_info) { | 
|  | auto& pb_block = *dst_block_info.Add(); | 
|  | pb_block.set_uncompressed_offset(block.uncompressed_offset); | 
|  | pb_block.set_uncompressed_length(block.uncompressed_length); | 
|  | pb_block.set_compressed_length(block.compressed_length); | 
|  | CHECK_LT(offset, recompressed_blob.size()); | 
|  | auto s1 = recompressed_blob.substr(offset, block.compressed_length); | 
|  | auto s2 = target_blob.substr(offset, block.compressed_length); | 
|  | if (s1 != s2) { | 
|  | ScopedTempFile patch; | 
|  | int err = | 
|  | bsdiff::bsdiff(reinterpret_cast<const unsigned char*>(s1.data()), | 
|  | s1.size(), | 
|  | reinterpret_cast<const unsigned char*>(s2.data()), | 
|  | s2.size(), | 
|  | patch.path().c_str(), | 
|  | nullptr); | 
|  | CHECK_EQ(err, 0); | 
|  | LOG(WARNING) << "Recompress Postfix patch size: " | 
|  | << utils::FileSize(patch.path()); | 
|  | std::string patch_content; | 
|  | TEST_AND_RETURN_FALSE(utils::ReadFile(patch.path(), &patch_content)); | 
|  | pb_block.set_postfix_bspatch(std::move(patch_content)); | 
|  | } | 
|  | // Include recompressed blob hash, so we can determine if the device | 
|  | // produces same compressed output | 
|  | Blob recompressed_blob_hash; | 
|  | TEST_AND_RETURN_FALSE(HashCalculator::RawHashOfBytes( | 
|  | s1.data(), s1.length(), &recompressed_blob_hash)); | 
|  | pb_block.set_sha256_hash(recompressed_blob_hash.data(), | 
|  | recompressed_blob_hash.size()); | 
|  |  | 
|  | offset += block.compressed_length; | 
|  | } | 
|  | return true; | 
|  | } | 
|  |  | 
|  | template <typename Blob> | 
|  | static bool TryBsdiff(Blob src, Blob dst, Blob* output) noexcept { | 
|  | static constexpr auto kLz4diffDefaultBrotliQuality = 9; | 
|  | CHECK_NE(output, nullptr); | 
|  | ScopedTempFile patch; | 
|  |  | 
|  | Blob bsdiff_delta; | 
|  | bsdiff::BsdiffPatchWriter patch_writer(patch.path(), | 
|  | {bsdiff::CompressorType::kBrotli}, | 
|  | kLz4diffDefaultBrotliQuality); | 
|  | TEST_AND_RETURN_FALSE(0 == bsdiff::bsdiff(src.data(), | 
|  | src.size(), | 
|  | dst.data(), | 
|  | dst.size(), | 
|  | &patch_writer, | 
|  | nullptr)); | 
|  |  | 
|  | TEST_AND_RETURN_FALSE(utils::ReadFile(patch.path(), &bsdiff_delta)); | 
|  | TEST_AND_RETURN_FALSE(!bsdiff_delta.empty()); | 
|  | *output = std::move(bsdiff_delta); | 
|  | return true; | 
|  | } | 
|  |  | 
|  | bool TryFindDeflates(puffin::Buffer data, | 
|  | std::vector<puffin::BitExtent>* deflates) { | 
|  | if (puffin::LocateDeflatesInZipArchive(data, deflates)) { | 
|  | return true; | 
|  | } | 
|  | deflates->clear(); | 
|  | if (puffin::LocateDeflatesInGzip(data, deflates)) { | 
|  | return true; | 
|  | } | 
|  | deflates->clear(); | 
|  | return false; | 
|  | } | 
|  |  | 
|  | static bool ConstructLz4diffPatch(Blob inner_patch, | 
|  | const Lz4diffHeader& header, | 
|  | Blob* output) { | 
|  | Blob patch(kLz4diffHeaderSize); | 
|  | std::memcpy(patch.data(), kLz4diffMagic.data(), kLz4diffMagic.size()); | 
|  | *reinterpret_cast<uint32_t*>(patch.data() + kLz4diffMagic.size()) = | 
|  | htobe32(kLz4diffVersion); | 
|  |  | 
|  | std::string serialized_pb; | 
|  | TEST_AND_RETURN_FALSE(header.SerializeToString(&serialized_pb)); | 
|  | *reinterpret_cast<uint32_t*>(patch.data() + kLz4diffMagic.size() + 4) = | 
|  | htobe32(serialized_pb.size()); | 
|  | patch.insert(patch.end(), serialized_pb.begin(), serialized_pb.end()); | 
|  | patch.insert(patch.end(), inner_patch.begin(), inner_patch.end()); | 
|  |  | 
|  | *output = std::move(patch); | 
|  | return true; | 
|  | } | 
|  |  | 
|  | static bool TryPuffdiff(puffin::Buffer src, | 
|  | puffin::Buffer dst, | 
|  | Blob* output) noexcept { | 
|  | CHECK_NE(output, nullptr); | 
|  | std::vector<puffin::BitExtent> src_deflates; | 
|  | TEST_AND_RETURN_FALSE(TryFindDeflates(src, &src_deflates)); | 
|  | std::vector<puffin::BitExtent> dst_deflates; | 
|  | TEST_AND_RETURN_FALSE(TryFindDeflates(dst, &dst_deflates)); | 
|  | if (src_deflates.empty() || dst_deflates.empty()) { | 
|  | return false; | 
|  | } | 
|  |  | 
|  | Blob puffdiff_delta; | 
|  | ScopedTempFile temp_file("puffdiff-delta.XXXXXX"); | 
|  | // Perform PuffDiff operation. | 
|  | TEST_AND_RETURN_FALSE(puffin::PuffDiff( | 
|  | src, dst, src_deflates, dst_deflates, temp_file.path(), &puffdiff_delta)); | 
|  | TEST_AND_RETURN_FALSE(!puffdiff_delta.empty()); | 
|  |  | 
|  | *output = std::move(puffdiff_delta); | 
|  | return true; | 
|  | } | 
|  |  | 
|  | static void StoreSrcCompressedFileInfo(const CompressedFile& src_file_info, | 
|  | Lz4diffHeader* header) { | 
|  | *header->mutable_src_info()->mutable_algo() = src_file_info.algo; | 
|  | header->mutable_src_info()->set_zero_padding_enabled( | 
|  | src_file_info.zero_padding_enabled); | 
|  | auto& src_blocks = *header->mutable_src_info()->mutable_block_info(); | 
|  | src_blocks.Clear(); | 
|  | for (const auto& block : src_file_info.blocks) { | 
|  | auto& block_info = *src_blocks.Add(); | 
|  | block_info.set_uncompressed_length(block.uncompressed_length); | 
|  | block_info.set_uncompressed_offset(block.uncompressed_offset); | 
|  | block_info.set_compressed_length(block.compressed_length); | 
|  | } | 
|  | return; | 
|  | } | 
|  |  | 
|  | bool Lz4Diff(std::string_view src, | 
|  | std::string_view dst, | 
|  | const CompressedFile& src_file_info, | 
|  | const CompressedFile& dst_file_info, | 
|  | Blob* output, | 
|  | InstallOperation::Type* op_type) noexcept { | 
|  | const auto& src_block_info = src_file_info.blocks; | 
|  | const auto& dst_block_info = dst_file_info.blocks; | 
|  |  | 
|  | auto decompressed_src = TryDecompressBlob( | 
|  | src, src_block_info, src_file_info.zero_padding_enabled); | 
|  | auto decompressed_dst = TryDecompressBlob( | 
|  | dst, dst_block_info, dst_file_info.zero_padding_enabled); | 
|  | if (decompressed_src.empty() || decompressed_dst.empty()) { | 
|  | LOG(ERROR) << "Failed to decompress input data"; | 
|  | return false; | 
|  | } | 
|  |  | 
|  | Lz4diffHeader header; | 
|  | // BSDIFF isn't supposed to fail, so return error if BSDIFF failed. | 
|  | Blob patch_data; | 
|  | TEST_AND_RETURN_FALSE( | 
|  | TryBsdiff(decompressed_src, decompressed_dst, &patch_data)); | 
|  | header.set_inner_type(InnerPatchType::BSDIFF); | 
|  | if (op_type) { | 
|  | *op_type = InstallOperation::LZ4DIFF_BSDIFF; | 
|  | } | 
|  | // PUFFDIFF might fail, as the input data might not be deflate compressed. | 
|  |  | 
|  | Blob puffdiff_delta; | 
|  | if (TryPuffdiff(decompressed_src, decompressed_dst, &puffdiff_delta) && | 
|  | puffdiff_delta.size() < patch_data.size()) { | 
|  | patch_data = std::move(puffdiff_delta); | 
|  | header.set_inner_type(InnerPatchType::PUFFDIFF); | 
|  | if (op_type) { | 
|  | *op_type = InstallOperation::LZ4DIFF_PUFFDIFF; | 
|  | } | 
|  | } | 
|  | // Free up memory used by |decompressed_src| , as we don't need it anymore. | 
|  | decompressed_src = {}; | 
|  |  | 
|  | auto recompressed_blob = TryCompressBlob(ToStringView(decompressed_dst), | 
|  | dst_block_info, | 
|  | dst_file_info.zero_padding_enabled, | 
|  | dst_file_info.algo); | 
|  | TEST_AND_RETURN_FALSE(recompressed_blob.size() > 0); | 
|  |  | 
|  | StoreSrcCompressedFileInfo(src_file_info, &header); | 
|  | StoreDstCompressedFileInfo( | 
|  | ToStringView(recompressed_blob), dst, dst_file_info, &header); | 
|  | return ConstructLz4diffPatch(std::move(patch_data), header, output); | 
|  | } | 
|  |  | 
|  | bool Lz4Diff(const Blob& src, | 
|  | const Blob& dst, | 
|  | const CompressedFile& src_file_info, | 
|  | const CompressedFile& dst_file_info, | 
|  | Blob* output, | 
|  | InstallOperation::Type* op_type) noexcept { | 
|  | return Lz4Diff(ToStringView(src), | 
|  | ToStringView(dst), | 
|  | src_file_info, | 
|  | dst_file_info, | 
|  | output, | 
|  | op_type); | 
|  | } | 
|  |  | 
|  | }  // namespace chromeos_update_engine |