/*
* 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 "fuse_provider.h"
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
#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;
if (stat(path.c_str(), &sb) == -1) {
fprintf(stderr, "failed to stat %s: %s\n", path.c_str(), strerror(errno));
return;
}
fd_.reset(open(path.c_str(), O_RDONLY));
if (fd_ == -1) {
fprintf(stderr, "failed to open %s: %s\n", path.c_str(), strerror(errno));
return;
}
file_size_ = sb.st_size;
fuse_block_size_ = block_size;
}
std::unique_ptr<FuseDataProvider> FuseFileDataProvider::CreateFromFile(const std::string& path,
uint32_t block_size) {
return std::make_unique<FuseFileDataProvider>(path, block_size);
}
bool FuseFileDataProvider::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) {
fprintf(stderr,
"Out of bound read, start block: %" PRIu32 ", fetch size: %" PRIu32
", file size %" PRIu64 "\n",
start_block, fetch_size, file_size_);
return false;
}
if (!android::base::ReadFullyAtOffset(fd_, buffer, fetch_size, offset)) {
fprintf(stderr, "Failed to read fetch size: %" PRIu32 " bytes data at offset %" PRIu64 ": %s\n",
fetch_size, offset, strerror(errno));
return false;
}
return true;
}
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. Two possibilities as below:
// 1: fetch_size < source_block_size_, the read_ranges is a blank range_set.
// Get the last block num through GetBlockNumber() of the offset block.
// 2: fetch_size >= source_block_size_, the last block num is already stored
// in read-ranges by GetSubRanges() above.
uint64_t tailing_offset =
read_ranges.value()
? static_cast<uint64_t>((read_ranges->cend() - 1)->second) * source_block_size_
: static_cast<uint64_t>(ranges_.GetBlockNumber(offset / source_block_size_)) *
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<FuseDataProvider> 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();
}
