cmds/idmap2/libidmap2/FabricatedOverlay.cpp - LeafOS-Project/android_frameworks_base - Gitiles

 /*
  * 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 "idmap2/FabricatedOverlay.h"

 #include <sys/stat.h>   // umask
 #include <sys/types.h>  // umask

 #include <android-base/file.h>
 #include <androidfw/ResourceUtils.h>
 #include <androidfw/StringPool.h>
 #include <google/protobuf/io/coded_stream.h>
 #include <google/protobuf/io/zero_copy_stream_impl.h>
 #include <utils/ByteOrder.h>
 #include <zlib.h>

 #include <fstream>
 #include <map>
 #include <memory>
 #include <string>
 #include <utility>

 namespace android::idmap2 {

 constexpr auto kBufferSize = 1024;

 namespace {
 bool Read32(std::istream& stream, uint32_t* out) {
   uint32_t value;
   if (stream.read(reinterpret_cast<char*>(&value), sizeof(uint32_t))) {
     *out = dtohl(value);
     return true;
   }
   return false;
 }

 void Write32(std::ostream& stream, uint32_t value) {
   uint32_t x = htodl(value);
   stream.write(reinterpret_cast<char*>(&x), sizeof(uint32_t));
 }
 }  // namespace

 FabricatedOverlay::FabricatedOverlay(pb::FabricatedOverlay&& overlay,
                                      std::string&& string_pool_data,
                                      std::vector<android::base::borrowed_fd> binary_files,
                                      off_t total_binary_bytes,
                                      std::optional<uint32_t> crc_from_disk)
     : overlay_pb_(std::forward<pb::FabricatedOverlay>(overlay)),
     string_pool_data_(std::move(string_pool_data)),
     binary_files_(std::move(binary_files)),
     total_binary_bytes_(total_binary_bytes),
     crc_from_disk_(crc_from_disk) {
 }

 FabricatedOverlay::Builder::Builder(const std::string& package_name, const std::string& name,
                                     const std::string& target_package_name) {
   package_name_ = package_name;
   name_ = name;
   target_package_name_ = target_package_name;
 }

 FabricatedOverlay::Builder& FabricatedOverlay::Builder::SetOverlayable(const std::string& name) {
   target_overlayable_ = name;
   return *this;
 }

 FabricatedOverlay::Builder& FabricatedOverlay::Builder::SetResourceValue(
     const std::string& resource_name, uint8_t data_type, uint32_t data_value,
     const std::string& configuration) {
   entries_.emplace_back(
       Entry{resource_name, data_type, data_value, "", std::nullopt, configuration});
   return *this;
 }

 FabricatedOverlay::Builder& FabricatedOverlay::Builder::SetResourceValue(
     const std::string& resource_name, uint8_t data_type, const std::string& data_string_value,
     const std::string& configuration) {
   entries_.emplace_back(
       Entry{resource_name, data_type, 0, data_string_value, std::nullopt, configuration});
   return *this;
 }

 FabricatedOverlay::Builder& FabricatedOverlay::Builder::SetResourceValue(
     const std::string& resource_name, std::optional<android::base::borrowed_fd>&& binary_value,
     const std::string& configuration) {
   entries_.emplace_back(Entry{resource_name, 0, 0, "", binary_value, configuration});
   return *this;
 }

 Result<FabricatedOverlay> FabricatedOverlay::Builder::Build() {
   using ConfigMap = std::map<std::string, TargetValue, std::less<>>;
   using EntryMap = std::map<std::string, ConfigMap, std::less<>>;
   using TypeMap = std::map<std::string, EntryMap, std::less<>>;
   using PackageMap = std::map<std::string, TypeMap, std::less<>>;
   PackageMap package_map;
   android::StringPool string_pool;
   for (const auto& res_entry : entries_) {
     StringPiece package_substr;
     StringPiece type_name;
     StringPiece entry_name;
     if (!android::ExtractResourceName(StringPiece(res_entry.resource_name), &package_substr,
                                       &type_name, &entry_name)) {
       return Error("failed to parse resource name '%s'", res_entry.resource_name.c_str());
     }

     std::string_view package_name = package_substr.empty() ? target_package_name_ : package_substr;
     if (type_name.empty()) {
       return Error("resource name '%s' missing type name", res_entry.resource_name.c_str());
     }

     if (entry_name.empty()) {
       return Error("resource name '%s' missing entry name", res_entry.resource_name.c_str());
     }

     auto package = package_map.find(package_name);
     if (package == package_map.end()) {
       package = package_map
                     .insert(std::make_pair(package_name, TypeMap()))
                     .first;
     }

     auto type = package->second.find(type_name);
     if (type == package->second.end()) {
       type = package->second.insert(std::make_pair(type_name, EntryMap())).first;
     }

     auto entry = type->second.find(entry_name);
     if (entry == type->second.end()) {
       entry = type->second.insert(std::make_pair(entry_name, ConfigMap())).first;
     }

     auto value = entry->second.find(res_entry.configuration);
     if (value == entry->second.end()) {
       value = entry->second.insert(std::make_pair(res_entry.configuration, TargetValue())).first;
     }

     value->second = TargetValue{res_entry.data_type, res_entry.data_value,
         res_entry.data_string_value, res_entry.data_binary_value};
   }

   pb::FabricatedOverlay overlay_pb;
   overlay_pb.set_package_name(package_name_);
   overlay_pb.set_name(name_);
   overlay_pb.set_target_package_name(target_package_name_);
   overlay_pb.set_target_overlayable(target_overlayable_);

   std::vector<android::base::borrowed_fd> binary_files;
   size_t total_binary_bytes = 0;
   // 16 for the number of bytes in the frro file before the binary data
   const size_t FRRO_HEADER_SIZE = 16;

   for (auto& package : package_map) {
     auto package_pb = overlay_pb.add_packages();
     package_pb->set_name(package.first);

     for (auto& type : package.second) {
       auto type_pb = package_pb->add_types();
       type_pb->set_name(type.first);

       for (auto& entry : type.second) {
         for (const auto& value: entry.second) {
           auto entry_pb = type_pb->add_entries();
           entry_pb->set_name(entry.first);
           entry_pb->set_configuration(value.first);
           pb::ResourceValue* pb_value = entry_pb->mutable_res_value();
           pb_value->set_data_type(value.second.data_type);
           if (value.second.data_type == Res_value::TYPE_STRING) {
             auto ref = string_pool.MakeRef(value.second.data_string_value);
             pb_value->set_data_value(ref.index());
           } else if (value.second.data_binary_value.has_value()) {
               pb_value->set_data_type(Res_value::TYPE_STRING);
               struct stat s;
               if (fstat(value.second.data_binary_value->get(), &s) == -1) {
                 return Error("unable to get size of binary file: %d", errno);
               }
               std::string uri
                   = StringPrintf("frro:/%s?offset=%d&size=%d", frro_path_.c_str(),
                                  static_cast<int> (FRRO_HEADER_SIZE + total_binary_bytes),
                                  static_cast<int> (s.st_size));
               total_binary_bytes += s.st_size;
               binary_files.emplace_back(value.second.data_binary_value->get());
               auto ref = string_pool.MakeRef(std::move(uri));
               pb_value->set_data_value(ref.index());
           } else {
             pb_value->set_data_value(value.second.data_value);
           }
         }
       }
     }
   }
   android::BigBuffer string_buffer(kBufferSize);
   android::StringPool::FlattenUtf8(&string_buffer, string_pool, nullptr);
   return FabricatedOverlay(std::move(overlay_pb), string_buffer.to_string(),
       std::move(binary_files), total_binary_bytes);
 }

 Result<FabricatedOverlay> FabricatedOverlay::FromBinaryStream(std::istream& stream) {
   uint32_t magic;
   if (!Read32(stream, &magic)) {
     return Error("Failed to read fabricated overlay magic.");
   }

   if (magic != kFabricatedOverlayMagic) {
     return Error("Not a fabricated overlay file.");
   }

   uint32_t version;
   if (!Read32(stream, &version)) {
     return Error("Failed to read fabricated overlay version.");
   }

   if (version < 1 || version > 3) {
     return Error("Invalid fabricated overlay version '%u'.", version);
   }

   uint32_t crc;
   if (!Read32(stream, &crc)) {
     return Error("Failed to read fabricated overlay crc.");
   }

   pb::FabricatedOverlay overlay{};
   std::string sp_data;
   uint32_t total_binary_bytes;
   if (version == 3) {
     if (!Read32(stream, &total_binary_bytes)) {
       return Error("Failed read total binary bytes.");
     }
     stream.seekg(total_binary_bytes, std::istream::cur);
   }
   if (version >= 2) {
     uint32_t sp_size;
     if (!Read32(stream, &sp_size)) {
       return Error("Failed read string pool size.");
     }
     std::string buf(sp_size, '\0');
     if (!stream.read(buf.data(), sp_size)) {
       return Error("Failed to read string pool.");
     }
     sp_data = buf;
   }
   if (!overlay.ParseFromIstream(&stream)) {
     return Error("Failed read fabricated overlay proto.");
   }

   // If the proto version is the latest version, then the contents of the proto must be the same
   // when the proto is re-serialized; otherwise, the crc must be calculated because migrating the
   // proto to the latest version will likely change the contents of the fabricated overlay.
   return FabricatedOverlay(std::move(overlay), std::move(sp_data), {}, total_binary_bytes,
                            version == kFabricatedOverlayCurrentVersion
                                                    ? std::optional<uint32_t>(crc)
                                                    : std::nullopt);
 }

 Result<FabricatedOverlay::SerializedData*> FabricatedOverlay::InitializeData() const {
   if (!data_.has_value()) {
     auto pb_size = overlay_pb_.ByteSizeLong();
     auto pb_data = std::unique_ptr<uint8_t[]>(new uint8_t[pb_size]);

     // Ensure serialization is deterministic
     google::protobuf::io::ArrayOutputStream array_stream(pb_data.get(), pb_size);
     google::protobuf::io::CodedOutputStream output_stream(&array_stream);
     output_stream.SetSerializationDeterministic(true);
     overlay_pb_.SerializeWithCachedSizes(&output_stream);
     if (output_stream.HadError() || pb_size != output_stream.ByteCount()) {
       return Error("Failed to serialize fabricated overlay.");
     }

     // Calculate the crc using the proto data and the version.
     uint32_t pb_crc = crc32(0L, Z_NULL, 0);
     pb_crc = crc32(pb_crc, reinterpret_cast<const uint8_t*>(&kFabricatedOverlayCurrentVersion),
                 sizeof(uint32_t));
     pb_crc = crc32(pb_crc, pb_data.get(), pb_size);

     data_ = SerializedData{std::move(pb_data), pb_size, pb_crc, string_pool_data_};
   }
   return &(*data_);
 }
 Result<uint32_t> FabricatedOverlay::GetCrc() const {
   if (crc_from_disk_.has_value()) {
     return *crc_from_disk_;
   }
   auto data = InitializeData();
   if (!data) {
     return data.GetError();
   }
   return (*data)->pb_crc;
 }

 Result<Unit> FabricatedOverlay::ToBinaryStream(std::ostream& stream) const {
   auto data = InitializeData();
   if (!data) {
     return data.GetError();
   }

   Write32(stream, kFabricatedOverlayMagic);
   Write32(stream, kFabricatedOverlayCurrentVersion);
   Write32(stream, (*data)->pb_crc);
   Write32(stream, total_binary_bytes_);
   std::string file_contents;
   for (const android::base::borrowed_fd fd : binary_files_) {
     if (!ReadFdToString(fd, &file_contents)) {
       return Error("Failed to read binary file data.");
     }
     stream.write(file_contents.data(), file_contents.length());
   }
   Write32(stream, (*data)->sp_data.length());
   stream.write((*data)->sp_data.data(), (*data)->sp_data.length());
   if (stream.bad()) {
     return Error("Failed to write string pool data.");
   }
   stream.write(reinterpret_cast<const char*>((*data)->pb_data.get()), (*data)->pb_data_size);
   if (stream.bad()) {
     return Error("Failed to write serialized fabricated overlay.");
   }

   return Unit{};
 }

 using FabContainer = FabricatedOverlayContainer;
 FabContainer::FabricatedOverlayContainer(FabricatedOverlay&& overlay, std::string&& path)
     : overlay_(std::forward<FabricatedOverlay>(overlay)), path_(std::forward<std::string>(path)) {
 }

 FabContainer::~FabricatedOverlayContainer() = default;

 Result<std::unique_ptr<FabContainer>> FabContainer::FromPath(std::string path) {
   std::fstream fin(path);
   auto overlay = FabricatedOverlay::FromBinaryStream(fin);
   if (!overlay) {
     return overlay.GetError();
   }
   return std::unique_ptr<FabContainer>(
       new FabricatedOverlayContainer(std::move(*overlay), std::move(path)));
 }

 std::unique_ptr<FabricatedOverlayContainer> FabContainer::FromOverlay(FabricatedOverlay&& overlay) {
   return std::unique_ptr<FabContainer>(
       new FabricatedOverlayContainer(std::move(overlay), {} /* path */));
 }

 OverlayManifestInfo FabContainer::GetManifestInfo() const {
   const pb::FabricatedOverlay& overlay_pb = overlay_.overlay_pb_;
   return OverlayManifestInfo{
       .package_name = overlay_pb.package_name(),
       .name = overlay_pb.name(),
       .target_package = overlay_pb.target_package_name(),
       .target_name = overlay_pb.target_overlayable(),
   };
 }

 Result<OverlayManifestInfo> FabContainer::FindOverlayInfo(const std::string& name) const {
   const OverlayManifestInfo info = GetManifestInfo();
   if (name != info.name) {
     return Error("Failed to find name '%s' in fabricated overlay", name.c_str());
   }
   return info;
 }

 Result<OverlayData> FabContainer::GetOverlayData(const OverlayManifestInfo& info) const {
   const pb::FabricatedOverlay& overlay_pb = overlay_.overlay_pb_;
   if (info.name != overlay_pb.name()) {
     return Error("Failed to find name '%s' in fabricated overlay", info.name.c_str());
   }

   OverlayData result{};
   for (const auto& package : overlay_pb.packages()) {
     for (const auto& type : package.types()) {
       for (const auto& entry : type.entries()) {
         auto name = base::StringPrintf("%s:%s/%s", package.name().c_str(), type.name().c_str(),
                                        entry.name().c_str());
         const auto& res_value = entry.res_value();
         result.pairs.emplace_back(OverlayData::Value{
             name, TargetValueWithConfig{.config = entry.configuration(), .value = TargetValue{
                     .data_type = static_cast<uint8_t>(res_value.data_type()),
                     .data_value = res_value.data_value()}}});
       }
     }
   }
   const uint32_t string_pool_data_length = overlay_.string_pool_data_.length();
   result.string_pool_data = OverlayData::InlineStringPoolData{
       .data = std::unique_ptr<uint8_t[]>(new uint8_t[string_pool_data_length]),
       .data_length = string_pool_data_length,
       .string_pool_offset = 0,
   };
   memcpy(result.string_pool_data->data.get(), overlay_.string_pool_data_.data(),
        string_pool_data_length);
   return result;
 }

 Result<uint32_t> FabContainer::GetCrc() const {
   return overlay_.GetCrc();
 }

 const std::string& FabContainer::GetPath() const {
   return path_;
 }

 Result<std::string> FabContainer::GetResourceName(ResourceId /* id */) const {
   return Error("Fabricated overlay does not contain resources.");
 }

 }  // namespace android::idmap2
	/*
	* 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 "idmap2/FabricatedOverlay.h"

	#include <sys/stat.h> // umask
	#include <sys/types.h> // umask

	#include <android-base/file.h>
	#include <androidfw/ResourceUtils.h>
	#include <androidfw/StringPool.h>
	#include <google/protobuf/io/coded_stream.h>
	#include <google/protobuf/io/zero_copy_stream_impl.h>
	#include <utils/ByteOrder.h>
	#include <zlib.h>

	#include <fstream>
	#include <map>
	#include <memory>
	#include <string>
	#include <utility>

	namespace android::idmap2 {

	constexpr auto kBufferSize = 1024;

	namespace {
	bool Read32(std::istream& stream, uint32_t* out) {
	uint32_t value;
	if (stream.read(reinterpret_cast<char*>(&value), sizeof(uint32_t))) {
	*out = dtohl(value);
	return true;
	}
	return false;
	}

	void Write32(std::ostream& stream, uint32_t value) {
	uint32_t x = htodl(value);
	stream.write(reinterpret_cast<char*>(&x), sizeof(uint32_t));
	}
	} // namespace

	FabricatedOverlay::FabricatedOverlay(pb::FabricatedOverlay&& overlay,
	std::string&& string_pool_data,
	std::vector<android::base::borrowed_fd> binary_files,
	off_t total_binary_bytes,
	std::optional<uint32_t> crc_from_disk)
	: overlay_pb_(std::forward<pb::FabricatedOverlay>(overlay)),
	string_pool_data_(std::move(string_pool_data)),
	binary_files_(std::move(binary_files)),
	total_binary_bytes_(total_binary_bytes),
	crc_from_disk_(crc_from_disk) {
	}

	FabricatedOverlay::Builder::Builder(const std::string& package_name, const std::string& name,
	const std::string& target_package_name) {
	package_name_ = package_name;
	name_ = name;
	target_package_name_ = target_package_name;
	}

	FabricatedOverlay::Builder& FabricatedOverlay::Builder::SetOverlayable(const std::string& name) {
	target_overlayable_ = name;
	return *this;
	}

	FabricatedOverlay::Builder& FabricatedOverlay::Builder::SetResourceValue(
	const std::string& resource_name, uint8_t data_type, uint32_t data_value,
	const std::string& configuration) {
	entries_.emplace_back(
	Entry{resource_name, data_type, data_value, "", std::nullopt, configuration});
	return *this;
	}

	FabricatedOverlay::Builder& FabricatedOverlay::Builder::SetResourceValue(
	const std::string& resource_name, uint8_t data_type, const std::string& data_string_value,
	const std::string& configuration) {
	entries_.emplace_back(
	Entry{resource_name, data_type, 0, data_string_value, std::nullopt, configuration});
	return *this;
	}

	FabricatedOverlay::Builder& FabricatedOverlay::Builder::SetResourceValue(
	const std::string& resource_name, std::optional<android::base::borrowed_fd>&& binary_value,
	const std::string& configuration) {
	entries_.emplace_back(Entry{resource_name, 0, 0, "", binary_value, configuration});
	return *this;
	}

	Result<FabricatedOverlay> FabricatedOverlay::Builder::Build() {
	using ConfigMap = std::map<std::string, TargetValue, std::less<>>;
	using EntryMap = std::map<std::string, ConfigMap, std::less<>>;
	using TypeMap = std::map<std::string, EntryMap, std::less<>>;
	using PackageMap = std::map<std::string, TypeMap, std::less<>>;
	PackageMap package_map;
	android::StringPool string_pool;
	for (const auto& res_entry : entries_) {
	StringPiece package_substr;
	StringPiece type_name;
	StringPiece entry_name;
	if (!android::ExtractResourceName(StringPiece(res_entry.resource_name), &package_substr,
	&type_name, &entry_name)) {
	return Error("failed to parse resource name '%s'", res_entry.resource_name.c_str());
	}

	std::string_view package_name = package_substr.empty() ? target_package_name_ : package_substr;
	if (type_name.empty()) {
	return Error("resource name '%s' missing type name", res_entry.resource_name.c_str());
	}

	if (entry_name.empty()) {
	return Error("resource name '%s' missing entry name", res_entry.resource_name.c_str());
	}

	auto package = package_map.find(package_name);
	if (package == package_map.end()) {
	package = package_map
	.insert(std::make_pair(package_name, TypeMap()))
	.first;
	}

	auto type = package->second.find(type_name);
	if (type == package->second.end()) {
	type = package->second.insert(std::make_pair(type_name, EntryMap())).first;
	}

	auto entry = type->second.find(entry_name);
	if (entry == type->second.end()) {
	entry = type->second.insert(std::make_pair(entry_name, ConfigMap())).first;
	}

	auto value = entry->second.find(res_entry.configuration);
	if (value == entry->second.end()) {
	value = entry->second.insert(std::make_pair(res_entry.configuration, TargetValue())).first;
	}

	value->second = TargetValue{res_entry.data_type, res_entry.data_value,
	res_entry.data_string_value, res_entry.data_binary_value};
	}

	pb::FabricatedOverlay overlay_pb;
	overlay_pb.set_package_name(package_name_);
	overlay_pb.set_name(name_);
	overlay_pb.set_target_package_name(target_package_name_);
	overlay_pb.set_target_overlayable(target_overlayable_);

	std::vector<android::base::borrowed_fd> binary_files;
	size_t total_binary_bytes = 0;
	// 16 for the number of bytes in the frro file before the binary data
	const size_t FRRO_HEADER_SIZE = 16;

	for (auto& package : package_map) {
	auto package_pb = overlay_pb.add_packages();
	package_pb->set_name(package.first);

	for (auto& type : package.second) {
	auto type_pb = package_pb->add_types();
	type_pb->set_name(type.first);

	for (auto& entry : type.second) {
	for (const auto& value: entry.second) {
	auto entry_pb = type_pb->add_entries();
	entry_pb->set_name(entry.first);
	entry_pb->set_configuration(value.first);
	pb::ResourceValue* pb_value = entry_pb->mutable_res_value();
	pb_value->set_data_type(value.second.data_type);
	if (value.second.data_type == Res_value::TYPE_STRING) {
	auto ref = string_pool.MakeRef(value.second.data_string_value);
	pb_value->set_data_value(ref.index());
	} else if (value.second.data_binary_value.has_value()) {
	pb_value->set_data_type(Res_value::TYPE_STRING);
	struct stat s;
	if (fstat(value.second.data_binary_value->get(), &s) == -1) {
	return Error("unable to get size of binary file: %d", errno);
	}
	std::string uri
	= StringPrintf("frro:/%s?offset=%d&size=%d", frro_path_.c_str(),
	static_cast<int> (FRRO_HEADER_SIZE + total_binary_bytes),
	static_cast<int> (s.st_size));
	total_binary_bytes += s.st_size;
	binary_files.emplace_back(value.second.data_binary_value->get());
	auto ref = string_pool.MakeRef(std::move(uri));
	pb_value->set_data_value(ref.index());
	} else {
	pb_value->set_data_value(value.second.data_value);
	}
	}
	}
	}
	}
	android::BigBuffer string_buffer(kBufferSize);
	android::StringPool::FlattenUtf8(&string_buffer, string_pool, nullptr);
	return FabricatedOverlay(std::move(overlay_pb), string_buffer.to_string(),
	std::move(binary_files), total_binary_bytes);
	}

	Result<FabricatedOverlay> FabricatedOverlay::FromBinaryStream(std::istream& stream) {
	uint32_t magic;
	if (!Read32(stream, &magic)) {
	return Error("Failed to read fabricated overlay magic.");
	}

	if (magic != kFabricatedOverlayMagic) {
	return Error("Not a fabricated overlay file.");
	}

	uint32_t version;
	if (!Read32(stream, &version)) {
	return Error("Failed to read fabricated overlay version.");
	}

	if (version < 1 \|\| version > 3) {
	return Error("Invalid fabricated overlay version '%u'.", version);
	}

	uint32_t crc;
	if (!Read32(stream, &crc)) {
	return Error("Failed to read fabricated overlay crc.");
	}

	pb::FabricatedOverlay overlay{};
	std::string sp_data;
	uint32_t total_binary_bytes;
	if (version == 3) {
	if (!Read32(stream, &total_binary_bytes)) {
	return Error("Failed read total binary bytes.");
	}
	stream.seekg(total_binary_bytes, std::istream::cur);
	}
	if (version >= 2) {
	uint32_t sp_size;
	if (!Read32(stream, &sp_size)) {
	return Error("Failed read string pool size.");
	}
	std::string buf(sp_size, '\0');
	if (!stream.read(buf.data(), sp_size)) {
	return Error("Failed to read string pool.");
	}
	sp_data = buf;
	}
	if (!overlay.ParseFromIstream(&stream)) {
	return Error("Failed read fabricated overlay proto.");
	}

	// If the proto version is the latest version, then the contents of the proto must be the same
	// when the proto is re-serialized; otherwise, the crc must be calculated because migrating the
	// proto to the latest version will likely change the contents of the fabricated overlay.
	return FabricatedOverlay(std::move(overlay), std::move(sp_data), {}, total_binary_bytes,
	version == kFabricatedOverlayCurrentVersion
	? std::optional<uint32_t>(crc)
	: std::nullopt);
	}

	Result<FabricatedOverlay::SerializedData*> FabricatedOverlay::InitializeData() const {
	if (!data_.has_value()) {
	auto pb_size = overlay_pb_.ByteSizeLong();
	auto pb_data = std::unique_ptr<uint8_t[]>(new uint8_t[pb_size]);

	// Ensure serialization is deterministic
	google::protobuf::io::ArrayOutputStream array_stream(pb_data.get(), pb_size);
	google::protobuf::io::CodedOutputStream output_stream(&array_stream);
	output_stream.SetSerializationDeterministic(true);
	overlay_pb_.SerializeWithCachedSizes(&output_stream);
	if (output_stream.HadError() \|\| pb_size != output_stream.ByteCount()) {
	return Error("Failed to serialize fabricated overlay.");
	}

	// Calculate the crc using the proto data and the version.
	uint32_t pb_crc = crc32(0L, Z_NULL, 0);
	pb_crc = crc32(pb_crc, reinterpret_cast<const uint8_t*>(&kFabricatedOverlayCurrentVersion),
	sizeof(uint32_t));
	pb_crc = crc32(pb_crc, pb_data.get(), pb_size);

	data_ = SerializedData{std::move(pb_data), pb_size, pb_crc, string_pool_data_};
	}
	return &(*data_);
	}
	Result<uint32_t> FabricatedOverlay::GetCrc() const {
	if (crc_from_disk_.has_value()) {
	return *crc_from_disk_;
	}
	auto data = InitializeData();
	if (!data) {
	return data.GetError();
	}
	return (*data)->pb_crc;
	}

	Result<Unit> FabricatedOverlay::ToBinaryStream(std::ostream& stream) const {
	auto data = InitializeData();
	if (!data) {
	return data.GetError();
	}

	Write32(stream, kFabricatedOverlayMagic);
	Write32(stream, kFabricatedOverlayCurrentVersion);
	Write32(stream, (*data)->pb_crc);
	Write32(stream, total_binary_bytes_);
	std::string file_contents;
	for (const android::base::borrowed_fd fd : binary_files_) {
	if (!ReadFdToString(fd, &file_contents)) {
	return Error("Failed to read binary file data.");
	}
	stream.write(file_contents.data(), file_contents.length());
	}
	Write32(stream, (*data)->sp_data.length());
	stream.write((data)->sp_data.data(), (data)->sp_data.length());
	if (stream.bad()) {
	return Error("Failed to write string pool data.");
	}
	stream.write(reinterpret_cast<const char>((data)->pb_data.get()), (*data)->pb_data_size);
	if (stream.bad()) {
	return Error("Failed to write serialized fabricated overlay.");
	}

	return Unit{};
	}

	using FabContainer = FabricatedOverlayContainer;
	FabContainer::FabricatedOverlayContainer(FabricatedOverlay&& overlay, std::string&& path)
	: overlay_(std::forward<FabricatedOverlay>(overlay)), path_(std::forward<std::string>(path)) {
	}

	FabContainer::~FabricatedOverlayContainer() = default;

	Result<std::unique_ptr<FabContainer>> FabContainer::FromPath(std::string path) {
	std::fstream fin(path);
	auto overlay = FabricatedOverlay::FromBinaryStream(fin);
	if (!overlay) {
	return overlay.GetError();
	}
	return std::unique_ptr<FabContainer>(
	new FabricatedOverlayContainer(std::move(*overlay), std::move(path)));
	}

	std::unique_ptr<FabricatedOverlayContainer> FabContainer::FromOverlay(FabricatedOverlay&& overlay) {
	return std::unique_ptr<FabContainer>(
	new FabricatedOverlayContainer(std::move(overlay), {} /* path */));
	}

	OverlayManifestInfo FabContainer::GetManifestInfo() const {
	const pb::FabricatedOverlay& overlay_pb = overlay_.overlay_pb_;
	return OverlayManifestInfo{
	.package_name = overlay_pb.package_name(),
	.name = overlay_pb.name(),
	.target_package = overlay_pb.target_package_name(),
	.target_name = overlay_pb.target_overlayable(),
	};
	}

	Result<OverlayManifestInfo> FabContainer::FindOverlayInfo(const std::string& name) const {
	const OverlayManifestInfo info = GetManifestInfo();
	if (name != info.name) {
	return Error("Failed to find name '%s' in fabricated overlay", name.c_str());
	}
	return info;
	}

	Result<OverlayData> FabContainer::GetOverlayData(const OverlayManifestInfo& info) const {
	const pb::FabricatedOverlay& overlay_pb = overlay_.overlay_pb_;
	if (info.name != overlay_pb.name()) {
	return Error("Failed to find name '%s' in fabricated overlay", info.name.c_str());
	}

	OverlayData result{};
	for (const auto& package : overlay_pb.packages()) {
	for (const auto& type : package.types()) {
	for (const auto& entry : type.entries()) {
	auto name = base::StringPrintf("%s:%s/%s", package.name().c_str(), type.name().c_str(),
	entry.name().c_str());
	const auto& res_value = entry.res_value();
	result.pairs.emplace_back(OverlayData::Value{
	name, TargetValueWithConfig{.config = entry.configuration(), .value = TargetValue{
	.data_type = static_cast<uint8_t>(res_value.data_type()),
	.data_value = res_value.data_value()}}});
	}
	}
	}
	const uint32_t string_pool_data_length = overlay_.string_pool_data_.length();
	result.string_pool_data = OverlayData::InlineStringPoolData{
	.data = std::unique_ptr<uint8_t[]>(new uint8_t[string_pool_data_length]),
	.data_length = string_pool_data_length,
	.string_pool_offset = 0,
	};
	memcpy(result.string_pool_data->data.get(), overlay_.string_pool_data_.data(),
	string_pool_data_length);
	return result;
	}

	Result<uint32_t> FabContainer::GetCrc() const {
	return overlay_.GetCrc();
	}

	const std::string& FabContainer::GetPath() const {
	return path_;
	}

	Result<std::string> FabContainer::GetResourceName(ResourceId /* id */) const {
	return Error("Fabricated overlay does not contain resources.");
	}

	} // namespace android::idmap2