| // | 
 | // 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 |