partition_tools/lpunpack.cc - platform/system/extras - Git at Google

 /*
  * Copyright (C) 2019 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 <fcntl.h>
 #include <getopt.h>
 #include <stdio.h>
 #include <sysexits.h>
 #include <sys/types.h>
 #include <unistd.h>

 #include <iostream>
 #include <limits>
 #include <string>
 #include <unordered_map>
 #include <unordered_set>

 #include <android-base/file.h>
 #include <android-base/parseint.h>
 #include <liblp/liblp.h>
 #include <sparse/sparse.h>

 using namespace android::fs_mgr;
 using android::base::unique_fd;
 using SparsePtr = std::unique_ptr<sparse_file, decltype(&sparse_file_destroy)>;

 class ImageExtractor final {
   public:
     ImageExtractor(unique_fd&& image_fd, std::unique_ptr<LpMetadata>&& metadata,
                    std::unordered_set<std::string>&& partitions, const std::string& output_dir);

     bool Extract();

   private:
     bool BuildPartitionList();
     bool ExtractPartition(const LpMetadataPartition* partition);
     bool ExtractExtent(const LpMetadataExtent& extent, int output_fd);

     unique_fd image_fd_;
     std::unique_ptr<LpMetadata> metadata_;
     std::unordered_set<std::string> partitions_;
     std::string output_dir_;
     std::unordered_map<std::string, const LpMetadataPartition*> partition_map_;
 };

 // Note that "sparse" here refers to filesystem sparse, not the Android sparse
 // file format.
 class SparseWriter final {
   public:
     SparseWriter(int output_fd, int image_fd, uint32_t block_size);

     bool WriteExtent(const LpMetadataExtent& extent);
     bool Finish();

   private:
     bool WriteBlock(const uint8_t* data);

     int output_fd_;
     int image_fd_;
     uint32_t block_size_;
     off_t hole_size_ = 0;
 };

 /* Prints program usage to |where|. */
 static int usage(int /* argc */, char* argv[]) {
     fprintf(stderr,
             "%s - command-line tool for extracting partition images from super\n"
             "\n"
             "Usage:\n"
             "  %s [options...] SUPER_IMAGE [OUTPUT_DIR]\n"
             "\n"
             "Options:\n"
             "  -p, --partition=NAME     Extract the named partition. This can\n"
             "                           be specified multiple times.\n"
             "  -S, --slot=NUM           Slot number (default is 0).\n",
             argv[0], argv[0]);
     return EX_USAGE;
 }

 int main(int argc, char* argv[]) {
     // clang-format off
     struct option options[] = {
         { "partition",  required_argument,  nullptr, 'p' },
         { "slot",       required_argument,  nullptr, 'S' },
         { nullptr,      0,                  nullptr, 0 },
     };
     // clang-format on

     uint32_t slot_num = 0;
     std::unordered_set<std::string> partitions;

     int rv, index;
     while ((rv = getopt_long_only(argc, argv, "+p:sh", options, &index)) != -1) {
         switch (rv) {
             case 'h':
                 usage(argc, argv);
                 return EX_OK;
             case '?':
                 std::cerr << "Unrecognized argument.\n";
                 return usage(argc, argv);
             case 'S':
                 if (!android::base::ParseUint(optarg, &slot_num)) {
                     std::cerr << "Slot must be a valid unsigned number.\n";
                     return usage(argc, argv);
                 }
                 break;
             case 'p':
                 partitions.emplace(optarg);
                 break;
         }
     }

     if (optind + 1 > argc) {
         std::cerr << "Missing super image argument.\n";
         return usage(argc, argv);
     }
     std::string super_path = argv[optind++];

     std::string output_dir = ".";
     if (optind + 1 <= argc) {
         output_dir = argv[optind++];
     }

     if (optind < argc) {
         std::cerr << "Unrecognized command-line arguments.\n";
         return usage(argc, argv);
     }

     // Done reading arguments; open super.img. PartitionOpener will decorate
     // relative paths with /dev/block/by-name, so get an absolute path here.
     std::string abs_super_path;
     if (!android::base::Realpath(super_path, &abs_super_path)) {
         std::cerr << "realpath failed: " << super_path << ": " << strerror(errno) << "\n";
         return EX_OSERR;
     }

     unique_fd fd(open(super_path.c_str(), O_RDONLY | O_CLOEXEC));
     if (fd < 0) {
         std::cerr << "open failed: " << abs_super_path << ": " << strerror(errno) << "\n";
         return EX_OSERR;
     }

     auto metadata = ReadMetadata(abs_super_path, slot_num);
     if (!metadata) {
         SparsePtr ptr(sparse_file_import(fd, false, false), sparse_file_destroy);
         if (ptr) {
             std::cerr << "This image appears to be a sparse image. It must be "
                          "unsparsed to be"
                       << " unpacked.\n";
             return EX_USAGE;
         }
         std::cerr << "Image does not appear to be in super-partition format.\n";
         return EX_USAGE;
     }

     ImageExtractor extractor(std::move(fd), std::move(metadata), std::move(partitions), output_dir);
     if (!extractor.Extract()) {
         return EX_SOFTWARE;
     }
     return EX_OK;
 }

 ImageExtractor::ImageExtractor(unique_fd&& image_fd, std::unique_ptr<LpMetadata>&& metadata,
                                std::unordered_set<std::string>&& partitions,
                                const std::string& output_dir)
     : image_fd_(std::move(image_fd)),
       metadata_(std::move(metadata)),
       partitions_(std::move(partitions)),
       output_dir_(output_dir) {}

 bool ImageExtractor::Extract() {
     if (!BuildPartitionList()) {
         return false;
     }

     for (const auto& [name, info] : partition_map_) {
         if (!ExtractPartition(info)) {
             return false;
         }
     }
     return true;
 }

 bool ImageExtractor::BuildPartitionList() {
     bool extract_all = partitions_.empty();

     for (const auto& partition : metadata_->partitions) {
         auto name = GetPartitionName(partition);
         if (extract_all || partitions_.count(name)) {
             partition_map_[name] = &partition;
             partitions_.erase(name);
         }
     }

     if (!extract_all && !partitions_.empty()) {
         std::cerr << "Could not find partition: " << *partitions_.begin() << "\n";
         return false;
     }
     return true;
 }

 bool ImageExtractor::ExtractPartition(const LpMetadataPartition* partition) {
     // Validate the extents and find the total image size.
     uint64_t total_size = 0;
     for (uint32_t i = 0; i < partition->num_extents; i++) {
         uint32_t index = partition->first_extent_index + i;
         const LpMetadataExtent& extent = metadata_->extents[index];

         if (extent.target_type != LP_TARGET_TYPE_LINEAR) {
             std::cerr << "Unsupported target type in extent: " << extent.target_type << "\n";
             return false;
         }
         if (extent.target_source != 0) {
             std::cerr << "Split super devices are not supported.\n";
             return false;
         }
         total_size += extent.num_sectors * LP_SECTOR_SIZE;
     }

     // Make a temporary file so we can import it with sparse_file_read.
     std::string output_path = output_dir_ + "/" + GetPartitionName(*partition) + ".img";
     unique_fd output_fd(open(output_path.c_str(), O_RDWR | O_CLOEXEC | O_CREAT | O_TRUNC, 0644));
     if (output_fd < 0) {
         std::cerr << "open failed: " << output_path << ": " << strerror(errno) << "\n";
         return false;
     }

     SparseWriter writer(output_fd, image_fd_, metadata_->geometry.logical_block_size);

     // Extract each extent into output_fd.
     for (uint32_t i = 0; i < partition->num_extents; i++) {
         uint32_t index = partition->first_extent_index + i;
         const LpMetadataExtent& extent = metadata_->extents[index];

         if (!writer.WriteExtent(extent)) {
             return false;
         }
     }
     return writer.Finish();
 }

 SparseWriter::SparseWriter(int output_fd, int image_fd, uint32_t block_size)
     : output_fd_(output_fd), image_fd_(image_fd), block_size_(block_size) {}

 bool SparseWriter::WriteExtent(const LpMetadataExtent& extent) {
     auto buffer = std::make_unique<uint8_t[]>(block_size_);

     off_t super_offset = extent.target_data * LP_SECTOR_SIZE;
     if (lseek(image_fd_, super_offset, SEEK_SET) < 0) {
         std::cerr << "image lseek failed: " << strerror(errno) << "\n";
         return false;
     }

     uint64_t remaining_bytes = extent.num_sectors * LP_SECTOR_SIZE;
     while (remaining_bytes) {
         if (remaining_bytes < block_size_) {
             std::cerr << "extent is not block-aligned\n";
             return false;
         }
         if (!android::base::ReadFully(image_fd_, buffer.get(), block_size_)) {
             std::cerr << "read failed: " << strerror(errno) << "\n";
             return false;
         }
         if (!WriteBlock(buffer.get())) {
             return false;
         }
         remaining_bytes -= block_size_;
     }
     return true;
 }

 static bool ShouldSkipChunk(const uint8_t* data, size_t len) {
     for (size_t i = 0; i < len; i++) {
         if (data[i] != 0) {
             return false;
         }
     }
     return true;
 }

 bool SparseWriter::WriteBlock(const uint8_t* data) {
     if (ShouldSkipChunk(data, block_size_)) {
         hole_size_ += block_size_;
         return true;
     }

     if (hole_size_) {
         if (lseek(output_fd_, hole_size_, SEEK_CUR) < 0) {
             std::cerr << "lseek failed: " << strerror(errno) << "\n";
             return false;
         }
         hole_size_ = 0;
     }
     if (!android::base::WriteFully(output_fd_, data, block_size_)) {
         std::cerr << "write failed: " << strerror(errno) << "\n";
         return false;
     }
     return true;
 }

 bool SparseWriter::Finish() {
     if (hole_size_) {
         off_t offset = lseek(output_fd_, 0, SEEK_CUR);
         if (offset < 0) {
             std::cerr << "lseek failed: " << strerror(errno) << "\n";
             return false;
         }
         if (ftruncate(output_fd_, offset + hole_size_) < 0) {
             std::cerr << "ftruncate failed: " << strerror(errno) << "\n";
             return false;
         }
     }
     return true;
 }
	/*
	* Copyright (C) 2019 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 <fcntl.h>
	#include <getopt.h>
	#include <stdio.h>
	#include <sysexits.h>
	#include <sys/types.h>
	#include <unistd.h>

	#include <iostream>
	#include <limits>
	#include <string>
	#include <unordered_map>
	#include <unordered_set>

	#include <android-base/file.h>
	#include <android-base/parseint.h>
	#include <liblp/liblp.h>
	#include <sparse/sparse.h>

	using namespace android::fs_mgr;
	using android::base::unique_fd;
	using SparsePtr = std::unique_ptr<sparse_file, decltype(&sparse_file_destroy)>;

	class ImageExtractor final {
	public:
	ImageExtractor(unique_fd&& image_fd, std::unique_ptr<LpMetadata>&& metadata,
	std::unordered_set<std::string>&& partitions, const std::string& output_dir);

	bool Extract();

	private:
	bool BuildPartitionList();
	bool ExtractPartition(const LpMetadataPartition* partition);
	bool ExtractExtent(const LpMetadataExtent& extent, int output_fd);

	unique_fd image_fd_;
	std::unique_ptr<LpMetadata> metadata_;
	std::unordered_set<std::string> partitions_;
	std::string output_dir_;
	std::unordered_map<std::string, const LpMetadataPartition*> partition_map_;
	};

	// Note that "sparse" here refers to filesystem sparse, not the Android sparse
	// file format.
	class SparseWriter final {
	public:
	SparseWriter(int output_fd, int image_fd, uint32_t block_size);

	bool WriteExtent(const LpMetadataExtent& extent);
	bool Finish();

	private:
	bool WriteBlock(const uint8_t* data);

	int output_fd_;
	int image_fd_;
	uint32_t block_size_;
	off_t hole_size_ = 0;
	};

	/* Prints program usage to \|where\|. */
	static int usage(int /* argc /, char argv[]) {
	fprintf(stderr,
	"%s - command-line tool for extracting partition images from super\n"
	"\n"
	"Usage:\n"
	" %s [options...] SUPER_IMAGE [OUTPUT_DIR]\n"
	"\n"
	"Options:\n"
	" -p, --partition=NAME Extract the named partition. This can\n"
	" be specified multiple times.\n"
	" -S, --slot=NUM Slot number (default is 0).\n",
	argv[0], argv[0]);
	return EX_USAGE;
	}

	int main(int argc, char* argv[]) {
	// clang-format off
	struct option options[] = {
	{ "partition", required_argument, nullptr, 'p' },
	{ "slot", required_argument, nullptr, 'S' },
	{ nullptr, 0, nullptr, 0 },
	};
	// clang-format on

	uint32_t slot_num = 0;
	std::unordered_set<std::string> partitions;

	int rv, index;
	while ((rv = getopt_long_only(argc, argv, "+p:sh", options, &index)) != -1) {
	switch (rv) {
	case 'h':
	usage(argc, argv);
	return EX_OK;
	case '?':
	std::cerr << "Unrecognized argument.\n";
	return usage(argc, argv);
	case 'S':
	if (!android::base::ParseUint(optarg, &slot_num)) {
	std::cerr << "Slot must be a valid unsigned number.\n";
	return usage(argc, argv);
	}
	break;
	case 'p':
	partitions.emplace(optarg);
	break;
	}
	}

	if (optind + 1 > argc) {
	std::cerr << "Missing super image argument.\n";
	return usage(argc, argv);
	}
	std::string super_path = argv[optind++];

	std::string output_dir = ".";
	if (optind + 1 <= argc) {
	output_dir = argv[optind++];
	}

	if (optind < argc) {
	std::cerr << "Unrecognized command-line arguments.\n";
	return usage(argc, argv);
	}

	// Done reading arguments; open super.img. PartitionOpener will decorate
	// relative paths with /dev/block/by-name, so get an absolute path here.
	std::string abs_super_path;
	if (!android::base::Realpath(super_path, &abs_super_path)) {
	std::cerr << "realpath failed: " << super_path << ": " << strerror(errno) << "\n";
	return EX_OSERR;
	}

	unique_fd fd(open(super_path.c_str(), O_RDONLY \| O_CLOEXEC));
	if (fd < 0) {
	std::cerr << "open failed: " << abs_super_path << ": " << strerror(errno) << "\n";
	return EX_OSERR;
	}

	auto metadata = ReadMetadata(abs_super_path, slot_num);
	if (!metadata) {
	SparsePtr ptr(sparse_file_import(fd, false, false), sparse_file_destroy);
	if (ptr) {
	std::cerr << "This image appears to be a sparse image. It must be "
	"unsparsed to be"
	<< " unpacked.\n";
	return EX_USAGE;
	}
	std::cerr << "Image does not appear to be in super-partition format.\n";
	return EX_USAGE;
	}

	ImageExtractor extractor(std::move(fd), std::move(metadata), std::move(partitions), output_dir);
	if (!extractor.Extract()) {
	return EX_SOFTWARE;
	}
	return EX_OK;
	}

	ImageExtractor::ImageExtractor(unique_fd&& image_fd, std::unique_ptr<LpMetadata>&& metadata,
	std::unordered_set<std::string>&& partitions,
	const std::string& output_dir)
	: image_fd_(std::move(image_fd)),
	metadata_(std::move(metadata)),
	partitions_(std::move(partitions)),
	output_dir_(output_dir) {}

	bool ImageExtractor::Extract() {
	if (!BuildPartitionList()) {
	return false;
	}

	for (const auto& [name, info] : partition_map_) {
	if (!ExtractPartition(info)) {
	return false;
	}
	}
	return true;
	}

	bool ImageExtractor::BuildPartitionList() {
	bool extract_all = partitions_.empty();

	for (const auto& partition : metadata_->partitions) {
	auto name = GetPartitionName(partition);
	if (extract_all \|\| partitions_.count(name)) {
	partition_map_[name] = &partition;
	partitions_.erase(name);
	}
	}

	if (!extract_all && !partitions_.empty()) {
	std::cerr << "Could not find partition: " << *partitions_.begin() << "\n";
	return false;
	}
	return true;
	}

	bool ImageExtractor::ExtractPartition(const LpMetadataPartition* partition) {
	// Validate the extents and find the total image size.
	uint64_t total_size = 0;
	for (uint32_t i = 0; i < partition->num_extents; i++) {
	uint32_t index = partition->first_extent_index + i;
	const LpMetadataExtent& extent = metadata_->extents[index];

	if (extent.target_type != LP_TARGET_TYPE_LINEAR) {
	std::cerr << "Unsupported target type in extent: " << extent.target_type << "\n";
	return false;
	}
	if (extent.target_source != 0) {
	std::cerr << "Split super devices are not supported.\n";
	return false;
	}
	total_size += extent.num_sectors * LP_SECTOR_SIZE;
	}

	// Make a temporary file so we can import it with sparse_file_read.
	std::string output_path = output_dir_ + "/" + GetPartitionName(*partition) + ".img";
	unique_fd output_fd(open(output_path.c_str(), O_RDWR \| O_CLOEXEC \| O_CREAT \| O_TRUNC, 0644));
	if (output_fd < 0) {
	std::cerr << "open failed: " << output_path << ": " << strerror(errno) << "\n";
	return false;
	}

	SparseWriter writer(output_fd, image_fd_, metadata_->geometry.logical_block_size);

	// Extract each extent into output_fd.
	for (uint32_t i = 0; i < partition->num_extents; i++) {
	uint32_t index = partition->first_extent_index + i;
	const LpMetadataExtent& extent = metadata_->extents[index];

	if (!writer.WriteExtent(extent)) {
	return false;
	}
	}
	return writer.Finish();
	}

	SparseWriter::SparseWriter(int output_fd, int image_fd, uint32_t block_size)
	: output_fd_(output_fd), image_fd_(image_fd), block_size_(block_size) {}

	bool SparseWriter::WriteExtent(const LpMetadataExtent& extent) {
	auto buffer = std::make_unique<uint8_t[]>(block_size_);

	off_t super_offset = extent.target_data * LP_SECTOR_SIZE;
	if (lseek(image_fd_, super_offset, SEEK_SET) < 0) {
	std::cerr << "image lseek failed: " << strerror(errno) << "\n";
	return false;
	}

	uint64_t remaining_bytes = extent.num_sectors * LP_SECTOR_SIZE;
	while (remaining_bytes) {
	if (remaining_bytes < block_size_) {
	std::cerr << "extent is not block-aligned\n";
	return false;
	}
	if (!android::base::ReadFully(image_fd_, buffer.get(), block_size_)) {
	std::cerr << "read failed: " << strerror(errno) << "\n";
	return false;
	}
	if (!WriteBlock(buffer.get())) {
	return false;
	}
	remaining_bytes -= block_size_;
	}
	return true;
	}

	static bool ShouldSkipChunk(const uint8_t* data, size_t len) {
	for (size_t i = 0; i < len; i++) {
	if (data[i] != 0) {
	return false;
	}
	}
	return true;
	}

	bool SparseWriter::WriteBlock(const uint8_t* data) {
	if (ShouldSkipChunk(data, block_size_)) {
	hole_size_ += block_size_;
	return true;
	}

	if (hole_size_) {
	if (lseek(output_fd_, hole_size_, SEEK_CUR) < 0) {
	std::cerr << "lseek failed: " << strerror(errno) << "\n";
	return false;
	}
	hole_size_ = 0;
	}
	if (!android::base::WriteFully(output_fd_, data, block_size_)) {
	std::cerr << "write failed: " << strerror(errno) << "\n";
	return false;
	}
	return true;
	}

	bool SparseWriter::Finish() {
	if (hole_size_) {
	off_t offset = lseek(output_fd_, 0, SEEK_CUR);
	if (offset < 0) {
	std::cerr << "lseek failed: " << strerror(errno) << "\n";
	return false;
	}
	if (ftruncate(output_fd_, offset + hole_size_) < 0) {
	std::cerr << "ftruncate failed: " << strerror(errno) << "\n";
	return false;
	}
	}
	return true;
	}