| /* |
| * Copyright (C) 2018 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 "images.h" |
| |
| #include <limits.h> |
| #include <sys/stat.h> |
| |
| #include <android-base/file.h> |
| |
| #include "reader.h" |
| #include "utility.h" |
| #include "writer.h" |
| |
| namespace android { |
| namespace fs_mgr { |
| |
| using android::base::borrowed_fd; |
| using android::base::unique_fd; |
| |
| #if defined(_WIN32) |
| static const int O_NOFOLLOW = 0; |
| #endif |
| |
| static bool IsEmptySuperImage(borrowed_fd fd) { |
| struct stat s; |
| if (fstat(fd.get(), &s) < 0) { |
| PERROR << __PRETTY_FUNCTION__ << " fstat failed"; |
| return false; |
| } |
| if (s.st_size < LP_METADATA_GEOMETRY_SIZE) { |
| return false; |
| } |
| |
| // Rewind back to the start, read the geometry struct. |
| LpMetadataGeometry geometry = {}; |
| if (SeekFile64(fd.get(), 0, SEEK_SET) < 0) { |
| PERROR << __PRETTY_FUNCTION__ << " lseek failed"; |
| return false; |
| } |
| if (!android::base::ReadFully(fd, &geometry, sizeof(geometry))) { |
| PERROR << __PRETTY_FUNCTION__ << " read failed"; |
| return false; |
| } |
| return geometry.magic == LP_METADATA_GEOMETRY_MAGIC; |
| } |
| |
| bool IsEmptySuperImage(const std::string& file) { |
| unique_fd fd = GetControlFileOrOpen(file, O_RDONLY | O_CLOEXEC); |
| if (fd < 0) { |
| PERROR << __PRETTY_FUNCTION__ << " open failed"; |
| return false; |
| } |
| return IsEmptySuperImage(fd); |
| } |
| |
| std::unique_ptr<LpMetadata> ReadFromImageFile(int fd) { |
| std::unique_ptr<uint8_t[]> buffer = std::make_unique<uint8_t[]>(LP_METADATA_GEOMETRY_SIZE); |
| if (SeekFile64(fd, 0, SEEK_SET) < 0) { |
| PERROR << __PRETTY_FUNCTION__ << " lseek failed"; |
| return nullptr; |
| } |
| if (!android::base::ReadFully(fd, buffer.get(), LP_METADATA_GEOMETRY_SIZE)) { |
| PERROR << __PRETTY_FUNCTION__ << " read failed"; |
| return nullptr; |
| } |
| LpMetadataGeometry geometry; |
| if (!ParseGeometry(buffer.get(), &geometry)) { |
| return nullptr; |
| } |
| return ParseMetadata(geometry, fd); |
| } |
| |
| std::unique_ptr<LpMetadata> ReadFromImageBlob(const void* data, size_t bytes) { |
| if (bytes < LP_METADATA_GEOMETRY_SIZE) { |
| LERROR << __PRETTY_FUNCTION__ << ": " << bytes << " is smaller than geometry header"; |
| return nullptr; |
| } |
| |
| LpMetadataGeometry geometry; |
| if (!ParseGeometry(data, &geometry)) { |
| return nullptr; |
| } |
| |
| const uint8_t* metadata_buffer = |
| reinterpret_cast<const uint8_t*>(data) + LP_METADATA_GEOMETRY_SIZE; |
| size_t metadata_buffer_size = bytes - LP_METADATA_GEOMETRY_SIZE; |
| return ParseMetadata(geometry, metadata_buffer, metadata_buffer_size); |
| } |
| |
| std::unique_ptr<LpMetadata> ReadFromImageFile(const std::string& image_file) { |
| unique_fd fd = GetControlFileOrOpen(image_file.c_str(), O_RDONLY | O_CLOEXEC); |
| if (fd < 0) { |
| PERROR << __PRETTY_FUNCTION__ << " open failed: " << image_file; |
| return nullptr; |
| } |
| return ReadFromImageFile(fd); |
| } |
| |
| bool WriteToImageFile(borrowed_fd fd, const LpMetadata& input) { |
| std::string geometry = SerializeGeometry(input.geometry); |
| std::string metadata = SerializeMetadata(input); |
| |
| std::string everything = geometry + metadata; |
| |
| if (!android::base::WriteFully(fd, everything.data(), everything.size())) { |
| PERROR << __PRETTY_FUNCTION__ << " write " << everything.size() << " bytes failed"; |
| return false; |
| } |
| return true; |
| } |
| |
| bool WriteToImageFile(const std::string& file, const LpMetadata& input) { |
| unique_fd fd(open(file.c_str(), O_CREAT | O_RDWR | O_TRUNC | O_CLOEXEC | O_BINARY, 0644)); |
| if (fd < 0) { |
| PERROR << __PRETTY_FUNCTION__ << " open failed: " << file; |
| return false; |
| } |
| return WriteToImageFile(fd, input); |
| } |
| |
| ImageBuilder::ImageBuilder(const LpMetadata& metadata, uint32_t block_size, |
| const std::map<std::string, std::string>& images, bool sparsify) |
| : metadata_(metadata), |
| geometry_(metadata.geometry), |
| block_size_(block_size), |
| sparsify_(sparsify), |
| images_(images) { |
| uint64_t total_size = GetTotalSuperPartitionSize(metadata); |
| if (block_size % LP_SECTOR_SIZE != 0) { |
| LERROR << "Block size must be a multiple of the sector size, " << LP_SECTOR_SIZE; |
| return; |
| } |
| if (total_size % block_size != 0) { |
| LERROR << "Device size must be a multiple of the block size, " << block_size; |
| return; |
| } |
| if (metadata.geometry.metadata_max_size % block_size != 0) { |
| LERROR << "Metadata max size must be a multiple of the block size, " << block_size; |
| return; |
| } |
| if (LP_METADATA_GEOMETRY_SIZE % block_size != 0) { |
| LERROR << "Geometry size is not a multiple of the block size, " << block_size; |
| return; |
| } |
| if (LP_PARTITION_RESERVED_BYTES % block_size != 0) { |
| LERROR << "Reserved size is not a multiple of the block size, " << block_size; |
| return; |
| } |
| |
| uint64_t num_blocks = total_size / block_size; |
| if (num_blocks >= UINT_MAX) { |
| // libsparse counts blocks in unsigned 32-bit integers, so we check to |
| // make sure we're not going to overflow. |
| LERROR << "Block device is too large to encode with libsparse."; |
| return; |
| } |
| |
| for (const auto& block_device : metadata.block_devices) { |
| SparsePtr file(sparse_file_new(block_size_, block_device.size), sparse_file_destroy); |
| if (!file) { |
| LERROR << "Could not allocate sparse file of size " << block_device.size; |
| return; |
| } |
| device_images_.emplace_back(std::move(file)); |
| } |
| } |
| |
| bool ImageBuilder::IsValid() const { |
| return device_images_.size() == metadata_.block_devices.size(); |
| } |
| |
| bool ImageBuilder::Export(const std::string& file) { |
| unique_fd fd(open(file.c_str(), O_CREAT | O_RDWR | O_TRUNC | O_CLOEXEC | O_BINARY, 0644)); |
| if (fd < 0) { |
| PERROR << "open failed: " << file; |
| return false; |
| } |
| if (device_images_.size() > 1) { |
| LERROR << "Cannot export to a single image on retrofit builds."; |
| return false; |
| } |
| // No gzip compression; no checksum. |
| int ret = sparse_file_write(device_images_[0].get(), fd, false, sparsify_, false); |
| if (ret != 0) { |
| LERROR << "sparse_file_write failed (error code " << ret << ")"; |
| return false; |
| } |
| return true; |
| } |
| |
| bool ImageBuilder::ExportFiles(const std::string& output_dir) { |
| for (size_t i = 0; i < device_images_.size(); i++) { |
| std::string name = GetBlockDevicePartitionName(metadata_.block_devices[i]); |
| std::string file_name = "super_" + name + ".img"; |
| std::string file_path = output_dir + "/" + file_name; |
| |
| static const int kOpenFlags = O_CREAT | O_RDWR | O_TRUNC | O_CLOEXEC | O_NOFOLLOW | O_BINARY; |
| unique_fd fd(open(file_path.c_str(), kOpenFlags, 0644)); |
| if (fd < 0) { |
| PERROR << "open failed: " << file_path; |
| return false; |
| } |
| // No gzip compression; no checksum. |
| int ret = sparse_file_write(device_images_[i].get(), fd, false, sparsify_, false); |
| if (ret != 0) { |
| LERROR << "sparse_file_write failed (error code " << ret << ")"; |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| bool ImageBuilder::AddData(sparse_file* file, const std::string& blob, uint64_t sector) { |
| uint32_t block; |
| if (!SectorToBlock(sector, &block)) { |
| return false; |
| } |
| void* data = const_cast<char*>(blob.data()); |
| int ret = sparse_file_add_data(file, data, blob.size(), block); |
| if (ret != 0) { |
| LERROR << "sparse_file_add_data failed (error code " << ret << ")"; |
| return false; |
| } |
| return true; |
| } |
| |
| bool ImageBuilder::SectorToBlock(uint64_t sector, uint32_t* block) { |
| // The caller must ensure that the metadata has an alignment that is a |
| // multiple of the block size. liblp will take care of the rest, ensuring |
| // that all partitions are on an aligned boundary. Therefore all writes |
| // should be block-aligned, and if they are not, the table was misconfigured. |
| // Note that the default alignment is 1MiB, which is a multiple of the |
| // default block size (4096). |
| if ((sector * LP_SECTOR_SIZE) % block_size_ != 0) { |
| LERROR << "sector " << sector << " is not aligned to block size " << block_size_; |
| return false; |
| } |
| *block = (sector * LP_SECTOR_SIZE) / block_size_; |
| return true; |
| } |
| |
| uint64_t ImageBuilder::BlockToSector(uint64_t block) const { |
| return (block * block_size_) / LP_SECTOR_SIZE; |
| } |
| |
| bool ImageBuilder::Build() { |
| if (sparse_file_add_fill(device_images_[0].get(), 0, LP_PARTITION_RESERVED_BYTES, 0) < 0) { |
| LERROR << "Could not add initial sparse block for reserved zeroes"; |
| return false; |
| } |
| |
| std::string geometry_blob = SerializeGeometry(geometry_); |
| std::string metadata_blob = SerializeMetadata(metadata_); |
| metadata_blob.resize(geometry_.metadata_max_size); |
| |
| // Two copies of geometry, then two copies of each metadata slot. |
| all_metadata_ += geometry_blob + geometry_blob; |
| for (size_t i = 0; i < geometry_.metadata_slot_count * 2; i++) { |
| all_metadata_ += metadata_blob; |
| } |
| |
| uint64_t first_sector = LP_PARTITION_RESERVED_BYTES / LP_SECTOR_SIZE; |
| if (!AddData(device_images_[0].get(), all_metadata_, first_sector)) { |
| return false; |
| } |
| |
| if (!CheckExtentOrdering()) { |
| return false; |
| } |
| |
| for (const auto& partition : metadata_.partitions) { |
| auto iter = images_.find(GetPartitionName(partition)); |
| if (iter == images_.end()) { |
| continue; |
| } |
| if (!AddPartitionImage(partition, iter->second)) { |
| return false; |
| } |
| images_.erase(iter); |
| } |
| |
| if (!images_.empty()) { |
| LERROR << "Partition image was specified but no partition was found."; |
| return false; |
| } |
| return true; |
| } |
| |
| static inline bool HasFillValue(uint32_t* buffer, size_t count) { |
| uint32_t fill_value = buffer[0]; |
| for (size_t i = 1; i < count; i++) { |
| if (fill_value != buffer[i]) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| bool ImageBuilder::AddPartitionImage(const LpMetadataPartition& partition, |
| const std::string& file) { |
| if (partition.num_extents == 0) { |
| LERROR << "Partition size is zero: " << GetPartitionName(partition); |
| return false; |
| } |
| |
| // Track which extent we're processing. |
| uint32_t extent_index = partition.first_extent_index; |
| |
| const LpMetadataExtent& extent = metadata_.extents[extent_index]; |
| if (extent.target_type != LP_TARGET_TYPE_LINEAR) { |
| LERROR << "Partition should only have linear extents: " << GetPartitionName(partition); |
| return false; |
| } |
| |
| int fd = OpenImageFile(file); |
| if (fd < 0) { |
| LERROR << "Could not open image for partition: " << GetPartitionName(partition); |
| return false; |
| } |
| |
| // Make sure the image does not exceed the partition size. |
| uint64_t file_length; |
| if (!GetDescriptorSize(fd, &file_length)) { |
| LERROR << "Could not compute image size"; |
| return false; |
| } |
| uint64_t partition_size = ComputePartitionSize(partition); |
| if (file_length > partition_size) { |
| LERROR << "Image for partition '" << GetPartitionName(partition) |
| << "' is greater than its size (" << file_length << ", expected " << partition_size |
| << ")"; |
| return false; |
| } |
| if (SeekFile64(fd, 0, SEEK_SET)) { |
| PERROR << "lseek failed"; |
| return false; |
| } |
| |
| // We track the current logical sector and the position the current extent |
| // ends at. |
| uint64_t output_sector = 0; |
| uint64_t extent_last_sector = extent.num_sectors; |
| |
| // We also track the output device and the current output block within that |
| // device. |
| uint32_t output_block; |
| if (!SectorToBlock(extent.target_data, &output_block)) { |
| return false; |
| } |
| sparse_file* output_device = device_images_[extent.target_source].get(); |
| |
| // Proceed to read the file and build sparse images. |
| uint64_t pos = 0; |
| uint64_t remaining = file_length; |
| while (remaining) { |
| // Check if we need to advance to the next extent. |
| if (output_sector == extent_last_sector) { |
| extent_index++; |
| if (extent_index >= partition.first_extent_index + partition.num_extents) { |
| LERROR << "image is larger than extent table"; |
| return false; |
| } |
| |
| const LpMetadataExtent& extent = metadata_.extents[extent_index]; |
| extent_last_sector += extent.num_sectors; |
| output_device = device_images_[extent.target_source].get(); |
| if (!SectorToBlock(extent.target_data, &output_block)) { |
| return false; |
| } |
| } |
| |
| uint32_t buffer[block_size_ / sizeof(uint32_t)]; |
| size_t read_size = remaining >= sizeof(buffer) ? sizeof(buffer) : size_t(remaining); |
| if (!android::base::ReadFully(fd, buffer, sizeof(buffer))) { |
| PERROR << "read failed"; |
| return false; |
| } |
| if (read_size != sizeof(buffer) || !HasFillValue(buffer, read_size / sizeof(uint32_t))) { |
| int rv = sparse_file_add_fd(output_device, fd, pos, read_size, output_block); |
| if (rv) { |
| LERROR << "sparse_file_add_fd failed with code: " << rv; |
| return false; |
| } |
| } else { |
| int rv = sparse_file_add_fill(output_device, buffer[0], read_size, output_block); |
| if (rv) { |
| LERROR << "sparse_file_add_fill failed with code: " << rv; |
| return false; |
| } |
| } |
| pos += read_size; |
| remaining -= read_size; |
| output_sector += block_size_ / LP_SECTOR_SIZE; |
| output_block++; |
| } |
| |
| return true; |
| } |
| |
| uint64_t ImageBuilder::ComputePartitionSize(const LpMetadataPartition& partition) const { |
| uint64_t sectors = 0; |
| for (size_t i = 0; i < partition.num_extents; i++) { |
| sectors += metadata_.extents[partition.first_extent_index + i].num_sectors; |
| } |
| return sectors * LP_SECTOR_SIZE; |
| } |
| |
| // For simplicity, we don't allow serializing any configuration: extents must |
| // be ordered, such that any extent at position I in the table occurs *before* |
| // any extent after position I, for the same block device. We validate that |
| // here. |
| // |
| // Without this, it would be more difficult to find the appropriate extent for |
| // an output block. With this guarantee it is a linear walk. |
| bool ImageBuilder::CheckExtentOrdering() { |
| std::vector<uint64_t> last_sectors(metadata_.block_devices.size()); |
| |
| for (const auto& extent : metadata_.extents) { |
| if (extent.target_type != LP_TARGET_TYPE_LINEAR) { |
| LERROR << "Extents must all be type linear."; |
| return false; |
| } |
| if (extent.target_data <= last_sectors[extent.target_source]) { |
| LERROR << "Extents must appear in increasing order."; |
| return false; |
| } |
| if ((extent.num_sectors * LP_SECTOR_SIZE) % block_size_ != 0) { |
| LERROR << "Extents must be aligned to the block size."; |
| return false; |
| } |
| last_sectors[extent.target_source] = extent.target_data; |
| } |
| return true; |
| } |
| |
| int ImageBuilder::OpenImageFile(const std::string& file) { |
| unique_fd source_fd = GetControlFileOrOpen(file.c_str(), O_RDONLY | O_CLOEXEC | O_BINARY); |
| if (source_fd < 0) { |
| PERROR << "open image file failed: " << file; |
| return -1; |
| } |
| |
| SparsePtr source(sparse_file_import(source_fd, true, true), sparse_file_destroy); |
| if (!source) { |
| int fd = source_fd.get(); |
| temp_fds_.push_back(std::move(source_fd)); |
| return fd; |
| } |
| |
| TemporaryFile tf; |
| if (tf.fd < 0) { |
| PERROR << "make temporary file failed"; |
| return -1; |
| } |
| |
| // We temporarily unsparse the file, rather than try to merge its chunks. |
| int rv = sparse_file_write(source.get(), tf.fd, false, false, false); |
| if (rv) { |
| LERROR << "sparse_file_write failed with code: " << rv; |
| return -1; |
| } |
| temp_fds_.push_back(android::base::unique_fd(tf.release())); |
| return temp_fds_.back().get(); |
| } |
| |
| bool WriteToImageFile(const std::string& file, const LpMetadata& metadata, uint32_t block_size, |
| const std::map<std::string, std::string>& images, bool sparsify) { |
| ImageBuilder builder(metadata, block_size, images, sparsify); |
| return builder.IsValid() && builder.Build() && builder.Export(file); |
| } |
| |
| bool WriteSplitImageFiles(const std::string& output_dir, const LpMetadata& metadata, |
| uint32_t block_size, const std::map<std::string, std::string>& images, |
| bool sparsify) { |
| ImageBuilder builder(metadata, block_size, images, sparsify); |
| return builder.IsValid() && builder.Build() && builder.ExportFiles(output_dir); |
| } |
| |
| } // namespace fs_mgr |
| } // namespace android |