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/*
* Copyright 2006 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 "otautil/sysutil.h"
#include <errno.h> // TEMP_FAILURE_RETRY
#include <fcntl.h>
#include <inttypes.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <algorithm>
#include <limits>
#include <string>
#include <vector>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/properties.h>
#include <android-base/strings.h>
#include <android-base/unique_fd.h>
#include <cutils/android_reboot.h>
BlockMapData BlockMapData::ParseBlockMapFile(const std::string& block_map_path) {
std::string content;
if (!android::base::ReadFileToString(block_map_path, &content)) {
LOG(ERROR) << "Failed to read " << block_map_path;
return {};
}
std::vector<std::string> lines = android::base::Split(android::base::Trim(content), "\n");
if (lines.size() < 4) {
LOG(ERROR) << "Block map file is too short: " << lines.size();
return {};
}
const std::string& block_dev = lines[0];
uint64_t file_size;
uint32_t blksize;
if (sscanf(lines[1].c_str(), "%" SCNu64 "%" SCNu32, &file_size, &blksize) != 2) {
LOG(ERROR) << "Failed to parse file size and block size: " << lines[1];
return {};
}
if (file_size == 0 || blksize == 0) {
LOG(ERROR) << "Invalid size in block map file: size " << file_size << ", blksize " << blksize;
return {};
}
size_t range_count;
if (sscanf(lines[2].c_str(), "%zu", &range_count) != 1) {
LOG(ERROR) << "Failed to parse block map header: " << lines[2];
return {};
}
uint64_t blocks = ((file_size - 1) / blksize) + 1;
if (blocks > std::numeric_limits<uint32_t>::max() || range_count == 0 ||
lines.size() != 3 + range_count) {
LOG(ERROR) << "Invalid data in block map file: size " << file_size << ", blksize " << blksize
<< ", range_count " << range_count << ", lines " << lines.size();
return {};
}
RangeSet ranges;
uint64_t remaining_blocks = blocks;
for (size_t i = 0; i < range_count; ++i) {
const std::string& line = lines[i + 3];
uint64_t start, end;
if (sscanf(line.c_str(), "%" SCNu64 "%" SCNu64, &start, &end) != 2) {
LOG(ERROR) << "failed to parse range " << i << ": " << line;
return {};
}
uint64_t range_blocks = end - start;
if (end <= start || range_blocks > remaining_blocks) {
LOG(ERROR) << "Invalid range: " << start << " " << end;
return {};
}
ranges.PushBack({ start, end });
remaining_blocks -= range_blocks;
}
return BlockMapData(block_dev, file_size, blksize, std::move(ranges));
}
bool MemMapping::MapFD(int fd) {
struct stat sb;
if (fstat(fd, &sb) == -1) {
PLOG(ERROR) << "fstat(" << fd << ") failed";
return false;
}
void* memPtr = mmap(nullptr, sb.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
if (memPtr == MAP_FAILED) {
PLOG(ERROR) << "mmap(" << sb.st_size << ", R, PRIVATE, " << fd << ", 0) failed";
return false;
}
addr = static_cast<unsigned char*>(memPtr);
length = sb.st_size;
ranges_.clear();
ranges_.emplace_back(MappedRange{ memPtr, static_cast<size_t>(sb.st_size) });
return true;
}
bool MemMapping::MapBlockFile(const std::string& filename) {
auto block_map_data = BlockMapData::ParseBlockMapFile(filename);
if (!block_map_data) {
return false;
}
if (block_map_data.file_size() > std::numeric_limits<size_t>::max()) {
LOG(ERROR) << "File size is too large for mmap " << block_map_data.file_size();
return false;
}
// Reserve enough contiguous address space for the whole file.
uint32_t blksize = block_map_data.block_size();
uint64_t blocks = ((block_map_data.file_size() - 1) / blksize) + 1;
void* reserve = mmap(nullptr, blocks * blksize, PROT_NONE, MAP_PRIVATE | MAP_ANON, -1, 0);
if (reserve == MAP_FAILED) {
PLOG(ERROR) << "failed to reserve address space";
return false;
}
android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(block_map_data.path().c_str(), O_RDONLY)));
if (fd == -1) {
PLOG(ERROR) << "failed to open block device " << block_map_data.path();
munmap(reserve, blocks * blksize);
return false;
}
ranges_.clear();
auto next = static_cast<unsigned char*>(reserve);
size_t remaining_size = blocks * blksize;
for (const auto& [start, end] : block_map_data.block_ranges()) {
size_t range_size = (end - start) * blksize;
void* range_start = mmap(next, range_size, PROT_READ, MAP_PRIVATE | MAP_FIXED, fd,
static_cast<off_t>(start) * blksize);
if (range_start == MAP_FAILED) {
PLOG(ERROR) << "failed to map range " << start << ": " << end;
munmap(reserve, blocks * blksize);
return false;
}
ranges_.emplace_back(MappedRange{ range_start, range_size });
next += range_size;
remaining_size -= range_size;
}
if (remaining_size != 0) {
LOG(ERROR) << "Invalid ranges: remaining_size " << remaining_size;
munmap(reserve, blocks * blksize);
return false;
}
addr = static_cast<unsigned char*>(reserve);
length = block_map_data.file_size();
LOG(INFO) << "mmapped " << block_map_data.block_ranges().size() << " ranges";
return true;
}
bool MemMapping::MapFile(const std::string& fn) {
if (fn.empty()) {
LOG(ERROR) << "Empty filename";
return false;
}
if (fn[0] == '@') {
// Block map file "@/cache/recovery/block.map".
if (!MapBlockFile(fn.substr(1))) {
LOG(ERROR) << "Map of '" << fn << "' failed";
return false;
}
} else {
// This is a regular file.
android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(fn.c_str(), O_RDONLY)));
if (fd == -1) {
PLOG(ERROR) << "Unable to open '" << fn << "'";
return false;
}
if (!MapFD(fd)) {
LOG(ERROR) << "Map of '" << fn << "' failed";
return false;
}
}
return true;
}
MemMapping::~MemMapping() {
for (const auto& range : ranges_) {
if (munmap(range.addr, range.length) == -1) {
PLOG(ERROR) << "Failed to munmap(" << range.addr << ", " << range.length << ")";
}
};
ranges_.clear();
}
bool reboot(const std::string& command) {
std::string cmd = command;
if (android::base::GetBoolProperty("ro.boot.quiescent", false)) {
cmd += ",quiescent";
}
return android::base::SetProperty(ANDROID_RB_PROPERTY, cmd);
}
std::vector<char*> StringVectorToNullTerminatedArray(const std::vector<std::string>& args) {
std::vector<char*> result(args.size());
std::transform(args.cbegin(), args.cend(), result.begin(),
[](const std::string& arg) { return const_cast<char*>(arg.c_str()); });
result.push_back(nullptr);
return result;
}
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