diff options
Diffstat (limited to 'fuse_sideload')
| -rw-r--r-- | fuse_sideload/Android.bp | 4 | ||||
| -rw-r--r-- | fuse_sideload/fuse_provider.cpp | 79 | ||||
| -rw-r--r-- | fuse_sideload/include/fuse_provider.h | 28 |
3 files changed, 111 insertions, 0 deletions
diff --git a/fuse_sideload/Android.bp b/fuse_sideload/Android.bp index 8548548d2..9bf19eb85 100644 --- a/fuse_sideload/Android.bp +++ b/fuse_sideload/Android.bp @@ -34,6 +34,10 @@ cc_library { "include", ], + static_libs: [ + "libotautil", + ], + shared_libs: [ "libbase", "libcrypto", diff --git a/fuse_sideload/fuse_provider.cpp b/fuse_sideload/fuse_provider.cpp index 58786f5f3..5ee6e247f 100644 --- a/fuse_sideload/fuse_provider.cpp +++ b/fuse_sideload/fuse_provider.cpp @@ -27,8 +27,11 @@ #include <functional> #include <android-base/file.h> +#include <android-base/logging.h> +#include <android-base/strings.h> #include "fuse_sideload.h" +#include "otautil/sysutil.h" FuseFileDataProvider::FuseFileDataProvider(const std::string& path, uint32_t block_size) { struct stat sb; @@ -69,3 +72,79 @@ bool FuseFileDataProvider::ReadBlockAlignedData(uint8_t* buffer, uint32_t fetch_ void FuseFileDataProvider::Close() { fd_.reset(); } + +FuseBlockDataProvider::FuseBlockDataProvider(uint64_t file_size, uint32_t fuse_block_size, + android::base::unique_fd&& fd, + uint32_t source_block_size, RangeSet ranges) + : FuseDataProvider(file_size, fuse_block_size), + fd_(std::move(fd)), + source_block_size_(source_block_size), + ranges_(std::move(ranges)) { + // Make sure the offset is also aligned with the blocks on the block device when we call + // ReadBlockAlignedData(). + CHECK_EQ(0, fuse_block_size_ % source_block_size_); +} + +bool FuseBlockDataProvider::ReadBlockAlignedData(uint8_t* buffer, uint32_t fetch_size, + uint32_t start_block) const { + uint64_t offset = static_cast<uint64_t>(start_block) * fuse_block_size_; + if (fetch_size > file_size_ || offset > file_size_ - fetch_size) { + LOG(ERROR) << "Out of bound read, offset: " << offset << ", fetch size: " << fetch_size + << ", file size " << file_size_; + return false; + } + + auto read_ranges = + ranges_.GetSubRanges(offset / source_block_size_, fetch_size / source_block_size_); + if (!read_ranges) { + return false; + } + + uint8_t* next_out = buffer; + for (const auto& [range_start, range_end] : read_ranges.value()) { + uint64_t bytes_start = static_cast<uint64_t>(range_start) * source_block_size_; + uint64_t bytes_to_read = static_cast<uint64_t>(range_end - range_start) * source_block_size_; + if (!android::base::ReadFullyAtOffset(fd_, next_out, bytes_to_read, bytes_start)) { + PLOG(ERROR) << "Failed to read " << bytes_to_read << " bytes at offset " << bytes_start; + return false; + } + + next_out += bytes_to_read; + } + + if (uint64_t tailing_bytes = fetch_size % source_block_size_; tailing_bytes != 0) { + // Calculate the offset to last partial block. + uint64_t tailing_offset = + read_ranges.value() + ? static_cast<uint64_t>((read_ranges->cend() - 1)->second) * source_block_size_ + : static_cast<uint64_t>(start_block) * source_block_size_; + if (!android::base::ReadFullyAtOffset(fd_, next_out, tailing_bytes, tailing_offset)) { + PLOG(ERROR) << "Failed to read tailing " << tailing_bytes << " bytes at offset " + << tailing_offset; + return false; + } + } + return true; +} + +std::unique_ptr<FuseBlockDataProvider> FuseBlockDataProvider::CreateFromBlockMap( + const std::string& block_map_path, uint32_t fuse_block_size) { + auto block_map = BlockMapData::ParseBlockMapFile(block_map_path); + if (!block_map) { + return nullptr; + } + + android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(block_map.path().c_str(), O_RDONLY))); + if (fd == -1) { + PLOG(ERROR) << "Failed to open " << block_map.path(); + return nullptr; + } + + return std::unique_ptr<FuseBlockDataProvider>( + new FuseBlockDataProvider(block_map.file_size(), fuse_block_size, std::move(fd), + block_map.block_size(), block_map.block_ranges())); +} + +void FuseBlockDataProvider::Close() { + fd_.reset(); +} diff --git a/fuse_sideload/include/fuse_provider.h b/fuse_sideload/include/fuse_provider.h index 59059cf9b..8d4ea4073 100644 --- a/fuse_sideload/include/fuse_provider.h +++ b/fuse_sideload/include/fuse_provider.h @@ -18,10 +18,13 @@ #include <stdint.h> +#include <memory> #include <string> #include <android-base/unique_fd.h> +#include "otautil/rangeset.h" + // This is the base class to read data from source and provide the data to FUSE. class FuseDataProvider { public: @@ -70,3 +73,28 @@ class FuseFileDataProvider : public FuseDataProvider { // The underlying source to read data from. android::base::unique_fd fd_; }; + +// This class parses a block map and reads data from the underlying block device. +class FuseBlockDataProvider : public FuseDataProvider { + public: + // Constructs the fuse provider from the block map. + static std::unique_ptr<FuseBlockDataProvider> CreateFromBlockMap( + const std::string& block_map_path, uint32_t fuse_block_size); + + RangeSet ranges() const { + return ranges_; + } + bool ReadBlockAlignedData(uint8_t* buffer, uint32_t fetch_size, + uint32_t start_block) const override; + void Close() override; + + private: + FuseBlockDataProvider(uint64_t file_size, uint32_t fuse_block_size, android::base::unique_fd&& fd, + uint32_t source_block_size, RangeSet ranges); + // The underlying block device to read data from. + android::base::unique_fd fd_; + // The block size of the source block device. + uint32_t source_block_size_; + // The block ranges from the source block device that consist of the file + RangeSet ranges_; +}; |