// Copyright (c) 2011 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. // This file contains the code to apply a Courgette patch. #include "courgette/ensemble.h" #include "base/basictypes.h" #include "base/file_util.h" #include "base/files/memory_mapped_file.h" #include "base/logging.h" #include "courgette/crc.h" #include "courgette/region.h" #include "courgette/streams.h" #include "courgette/simple_delta.h" #include "courgette/patcher_x86_32.h" namespace courgette { // EnsemblePatchApplication is all the logic and data required to apply the // multi-stage patch. class EnsemblePatchApplication { public: EnsemblePatchApplication(); ~EnsemblePatchApplication(); Status ReadHeader(SourceStream* header_stream); Status InitBase(const Region& region); Status ValidateBase(); Status ReadInitialParameters(SourceStream* initial_parameters); Status PredictTransformParameters(SinkStreamSet* predicted_parameters); Status SubpatchTransformParameters(SinkStreamSet* prediction, SourceStream* correction, SourceStreamSet* corrected_parameters); Status TransformUp(SourceStreamSet* parameters, SinkStreamSet* transformed_elements); Status SubpatchTransformedElements(SinkStreamSet* elements, SourceStream* correction, SourceStreamSet* corrected_elements); Status TransformDown(SourceStreamSet* transformed_elements, SinkStream* basic_elements); Status SubpatchFinalOutput(SourceStream* original, SourceStream* correction, SinkStream* corrected_ensemble); private: Status SubpatchStreamSets(SinkStreamSet* predicted_items, SourceStream* correction, SourceStreamSet* corrected_items, SinkStream* corrected_items_storage); Region base_region_; // Location of in-memory copy of 'old' version. uint32 source_checksum_; uint32 target_checksum_; uint32 final_patch_input_size_prediction_; std::vector<TransformationPatcher*> patchers_; SinkStream corrected_parameters_storage_; SinkStream corrected_elements_storage_; DISALLOW_COPY_AND_ASSIGN(EnsemblePatchApplication); }; EnsemblePatchApplication::EnsemblePatchApplication() : source_checksum_(0), target_checksum_(0), final_patch_input_size_prediction_(0) { } EnsemblePatchApplication::~EnsemblePatchApplication() { for (size_t i = 0; i < patchers_.size(); ++i) { delete patchers_[i]; } } Status EnsemblePatchApplication::ReadHeader(SourceStream* header_stream) { uint32 magic; if (!header_stream->ReadVarint32(&magic)) return C_BAD_ENSEMBLE_MAGIC; if (magic != CourgettePatchFile::kMagic) return C_BAD_ENSEMBLE_MAGIC; uint32 version; if (!header_stream->ReadVarint32(&version)) return C_BAD_ENSEMBLE_VERSION; if (version != CourgettePatchFile::kVersion) return C_BAD_ENSEMBLE_VERSION; if (!header_stream->ReadVarint32(&source_checksum_)) return C_BAD_ENSEMBLE_HEADER; if (!header_stream->ReadVarint32(&target_checksum_)) return C_BAD_ENSEMBLE_HEADER; if (!header_stream->ReadVarint32(&final_patch_input_size_prediction_)) return C_BAD_ENSEMBLE_HEADER; return C_OK; } Status EnsemblePatchApplication::InitBase(const Region& region) { base_region_.assign(region); return C_OK; } Status EnsemblePatchApplication::ValidateBase() { uint32 checksum = CalculateCrc(base_region_.start(), base_region_.length()); if (source_checksum_ != checksum) return C_BAD_ENSEMBLE_CRC; return C_OK; } Status EnsemblePatchApplication::ReadInitialParameters( SourceStream* transformation_parameters) { uint32 number_of_transformations = 0; if (!transformation_parameters->ReadVarint32(&number_of_transformations)) return C_BAD_ENSEMBLE_HEADER; for (size_t i = 0; i < number_of_transformations; ++i) { uint32 kind; if (!transformation_parameters->ReadVarint32(&kind)) return C_BAD_ENSEMBLE_HEADER; TransformationPatcher* patcher = NULL; switch (kind) { case EXE_WIN_32_X86: patcher = new PatcherX86_32(base_region_); break; case EXE_ELF_32_X86: patcher = new PatcherX86_32(base_region_); break; case EXE_ELF_32_ARM: patcher = new PatcherX86_32(base_region_); break; case EXE_WIN_32_X64: patcher = new PatcherX86_32(base_region_); break; } if (patcher) patchers_.push_back(patcher); else return C_BAD_ENSEMBLE_HEADER; } for (size_t i = 0; i < patchers_.size(); ++i) { Status status = patchers_[i]->Init(transformation_parameters); if (status != C_OK) return status; } // All transformation_parameters should have been consumed by the above loop. if (!transformation_parameters->Empty()) return C_BAD_ENSEMBLE_HEADER; return C_OK; } Status EnsemblePatchApplication::PredictTransformParameters( SinkStreamSet* all_predicted_parameters) { for (size_t i = 0; i < patchers_.size(); ++i) { SinkStreamSet single_predicted_parameters; Status status = patchers_[i]->PredictTransformParameters(&single_predicted_parameters); if (status != C_OK) return status; if (!all_predicted_parameters->WriteSet(&single_predicted_parameters)) return C_STREAM_ERROR; } return C_OK; } Status EnsemblePatchApplication::SubpatchTransformParameters( SinkStreamSet* predicted_parameters, SourceStream* correction, SourceStreamSet* corrected_parameters) { return SubpatchStreamSets(predicted_parameters, correction, corrected_parameters, &corrected_parameters_storage_); } Status EnsemblePatchApplication::TransformUp( SourceStreamSet* parameters, SinkStreamSet* transformed_elements) { for (size_t i = 0; i < patchers_.size(); ++i) { SourceStreamSet single_parameters; if (!parameters->ReadSet(&single_parameters)) return C_STREAM_ERROR; SinkStreamSet single_transformed_element; Status status = patchers_[i]->Transform(&single_parameters, &single_transformed_element); if (status != C_OK) return status; if (!single_parameters.Empty()) return C_STREAM_NOT_CONSUMED; if (!transformed_elements->WriteSet(&single_transformed_element)) return C_STREAM_ERROR; } if (!parameters->Empty()) return C_STREAM_NOT_CONSUMED; return C_OK; } Status EnsemblePatchApplication::SubpatchTransformedElements( SinkStreamSet* predicted_elements, SourceStream* correction, SourceStreamSet* corrected_elements) { return SubpatchStreamSets(predicted_elements, correction, corrected_elements, &corrected_elements_storage_); } Status EnsemblePatchApplication::TransformDown( SourceStreamSet* transformed_elements, SinkStream* basic_elements) { // Construct blob of original input followed by reformed elements. if (!basic_elements->Reserve(final_patch_input_size_prediction_)) { return C_STREAM_ERROR; } // The original input: if (!basic_elements->Write(base_region_.start(), base_region_.length())) return C_STREAM_ERROR; for (size_t i = 0; i < patchers_.size(); ++i) { SourceStreamSet single_corrected_element; if (!transformed_elements->ReadSet(&single_corrected_element)) return C_STREAM_ERROR; Status status = patchers_[i]->Reform(&single_corrected_element, basic_elements); if (status != C_OK) return status; if (!single_corrected_element.Empty()) return C_STREAM_NOT_CONSUMED; } if (!transformed_elements->Empty()) return C_STREAM_NOT_CONSUMED; // We have totally consumed transformed_elements, so can free the // storage to which it referred. corrected_elements_storage_.Retire(); return C_OK; } Status EnsemblePatchApplication::SubpatchFinalOutput( SourceStream* original, SourceStream* correction, SinkStream* corrected_ensemble) { Status delta_status = ApplySimpleDelta(original, correction, corrected_ensemble); if (delta_status != C_OK) return delta_status; if (CalculateCrc(corrected_ensemble->Buffer(), corrected_ensemble->Length()) != target_checksum_) return C_BAD_ENSEMBLE_CRC; return C_OK; } Status EnsemblePatchApplication::SubpatchStreamSets( SinkStreamSet* predicted_items, SourceStream* correction, SourceStreamSet* corrected_items, SinkStream* corrected_items_storage) { SinkStream linearized_predicted_items; if (!predicted_items->CopyTo(&linearized_predicted_items)) return C_STREAM_ERROR; SourceStream prediction; prediction.Init(linearized_predicted_items); Status status = ApplySimpleDelta(&prediction, correction, corrected_items_storage); if (status != C_OK) return status; if (!corrected_items->Init(corrected_items_storage->Buffer(), corrected_items_storage->Length())) return C_STREAM_ERROR; return C_OK; } Status ApplyEnsemblePatch(SourceStream* base, SourceStream* patch, SinkStream* output) { Status status; EnsemblePatchApplication patch_process; status = patch_process.ReadHeader(patch); if (status != C_OK) return status; status = patch_process.InitBase(Region(base->Buffer(), base->Remaining())); if (status != C_OK) return status; status = patch_process.ValidateBase(); if (status != C_OK) return status; // The rest of the patch stream is a StreamSet. SourceStreamSet patch_streams; patch_streams.Init(patch); SourceStream* transformation_descriptions = patch_streams.stream(0); SourceStream* parameter_correction = patch_streams.stream(1); SourceStream* transformed_elements_correction = patch_streams.stream(2); SourceStream* ensemble_correction = patch_streams.stream(3); status = patch_process.ReadInitialParameters(transformation_descriptions); if (status != C_OK) return status; SinkStreamSet predicted_parameters; status = patch_process.PredictTransformParameters(&predicted_parameters); if (status != C_OK) return status; SourceStreamSet corrected_parameters; status = patch_process.SubpatchTransformParameters(&predicted_parameters, parameter_correction, &corrected_parameters); if (status != C_OK) return status; SinkStreamSet transformed_elements; status = patch_process.TransformUp(&corrected_parameters, &transformed_elements); if (status != C_OK) return status; SourceStreamSet corrected_transformed_elements; status = patch_process.SubpatchTransformedElements( &transformed_elements, transformed_elements_correction, &corrected_transformed_elements); if (status != C_OK) return status; SinkStream original_ensemble_and_corrected_base_elements; status = patch_process.TransformDown( &corrected_transformed_elements, &original_ensemble_and_corrected_base_elements); if (status != C_OK) return status; SourceStream final_patch_prediction; final_patch_prediction.Init(original_ensemble_and_corrected_base_elements); status = patch_process.SubpatchFinalOutput(&final_patch_prediction, ensemble_correction, output); if (status != C_OK) return status; return C_OK; } Status ApplyEnsemblePatch(const base::FilePath::CharType* old_file_name, const base::FilePath::CharType* patch_file_name, const base::FilePath::CharType* new_file_name) { // First read enough of the patch file to validate the header is well-formed. // A few varint32 numbers should fit in 100. base::FilePath patch_file_path(patch_file_name); base::MemoryMappedFile patch_file; if (!patch_file.Initialize(patch_file_path)) return C_READ_OPEN_ERROR; // 'Dry-run' the first step of the patch process to validate format of header. SourceStream patch_header_stream; patch_header_stream.Init(patch_file.data(), patch_file.length()); EnsemblePatchApplication patch_process; Status status = patch_process.ReadHeader(&patch_header_stream); if (status != C_OK) return status; // Read the old_file. base::FilePath old_file_path(old_file_name); base::MemoryMappedFile old_file; if (!old_file.Initialize(old_file_path)) return C_READ_ERROR; // Apply patch on streams. SourceStream old_source_stream; SourceStream patch_source_stream; old_source_stream.Init(old_file.data(), old_file.length()); patch_source_stream.Init(patch_file.data(), patch_file.length()); SinkStream new_sink_stream; status = ApplyEnsemblePatch(&old_source_stream, &patch_source_stream, &new_sink_stream); if (status != C_OK) return status; // Write the patched data to |new_file_name|. base::FilePath new_file_path(new_file_name); int written = file_util::WriteFile( new_file_path, reinterpret_cast<const char*>(new_sink_stream.Buffer()), static_cast<int>(new_sink_stream.Length())); if (written == -1) return C_WRITE_OPEN_ERROR; if (static_cast<size_t>(written) != new_sink_stream.Length()) return C_WRITE_ERROR; return C_OK; } } // namespace