Move out the code to parse block map in MemMap
We will reuse them to implement the fuse provider from block maps.
Test: unit tests pass, sideload an OTA
Change-Id: Iaa409d19569c4ccc0bb24e12518044fcddb45c69
diff --git a/otautil/sysutil.cpp b/otautil/sysutil.cpp
index d8969a0..8366fa0 100644
--- a/otautil/sysutil.cpp
+++ b/otautil/sysutil.cpp
@@ -18,12 +18,13 @@
#include <errno.h> // TEMP_FAILURE_RETRY
#include <fcntl.h>
-#include <stdint.h> // SIZE_MAX
+#include <inttypes.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <algorithm>
+#include <limits>
#include <string>
#include <vector>
@@ -34,6 +35,68 @@
#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) {
@@ -55,115 +118,61 @@
return true;
}
-// A "block map" which looks like this (from uncrypt/uncrypt.cpp):
-//
-// /dev/block/platform/msm_sdcc.1/by-name/userdata # block device
-// 49652 4096 # file size in bytes, block size
-// 3 # count of block ranges
-// 1000 1008 # block range 0
-// 2100 2102 # ... block range 1
-// 30 33 # ... block range 2
-//
-// Each block range represents a half-open interval; the line "30 33" reprents the blocks
-// [30, 31, 32].
bool MemMapping::MapBlockFile(const std::string& filename) {
- std::string content;
- if (!android::base::ReadFileToString(filename, &content)) {
- PLOG(ERROR) << "Failed to read " << filename;
+ auto block_map_data = BlockMapData::ParseBlockMapFile(filename);
+ if (!block_map_data) {
return false;
}
- 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 false;
- }
-
- size_t size;
- size_t blksize;
- if (sscanf(lines[1].c_str(), "%zu %zu", &size, &blksize) != 2) {
- LOG(ERROR) << "Failed to parse file size and block size: " << lines[1];
- return false;
- }
-
- 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 false;
- }
-
- size_t blocks;
- if (blksize != 0) {
- blocks = ((size - 1) / blksize) + 1;
- }
- if (size == 0 || blksize == 0 || blocks > SIZE_MAX / blksize || range_count == 0 ||
- lines.size() != 3 + range_count) {
- LOG(ERROR) << "Invalid data in block map file: size " << size << ", blksize " << blksize
- << ", range_count " << range_count << ", lines " << lines.size();
+ 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;
}
- const std::string& block_dev = lines[0];
- android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(block_dev.c_str(), O_RDONLY)));
+ 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_dev;
+ PLOG(ERROR) << "failed to open block device " << block_map_data.path();
munmap(reserve, blocks * blksize);
return false;
}
ranges_.clear();
- unsigned char* next = static_cast<unsigned char*>(reserve);
+ auto next = static_cast<unsigned char*>(reserve);
size_t remaining_size = blocks * blksize;
- bool success = true;
- for (size_t i = 0; i < range_count; ++i) {
- const std::string& line = lines[i + 3];
-
- size_t start, end;
- if (sscanf(line.c_str(), "%zu %zu\n", &start, &end) != 2) {
- LOG(ERROR) << "failed to parse range " << i << ": " << line;
- success = false;
- break;
- }
+ for (const auto& [start, end] : block_map_data.block_ranges()) {
size_t range_size = (end - start) * blksize;
- if (end <= start || (end - start) > SIZE_MAX / blksize || range_size > remaining_size) {
- LOG(ERROR) << "Invalid range: " << start << " " << end;
- success = false;
- break;
- }
-
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 " << i << ": " << line;
- success = false;
- break;
+ 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 (success && remaining_size != 0) {
+ if (remaining_size != 0) {
LOG(ERROR) << "Invalid ranges: remaining_size " << remaining_size;
- success = false;
- }
- if (!success) {
munmap(reserve, blocks * blksize);
return false;
}
addr = static_cast<unsigned char*>(reserve);
- length = size;
+ length = block_map_data.file_size();
- LOG(INFO) << "mmapped " << range_count << " ranges";
+ LOG(INFO) << "mmapped " << block_map_data.block_ranges().size() << " ranges";
return true;
}