diff options
Diffstat (limited to 'update_verifier')
| -rw-r--r-- | update_verifier/Android.mk | 5 | ||||
| -rw-r--r-- | update_verifier/update_verifier.cpp | 131 |
2 files changed, 124 insertions, 12 deletions
diff --git a/update_verifier/Android.mk b/update_verifier/Android.mk index 8f5194db6..090db998b 100644 --- a/update_verifier/Android.mk +++ b/update_verifier/Android.mk @@ -18,8 +18,11 @@ include $(CLEAR_VARS) LOCAL_CLANG := true LOCAL_SRC_FILES := update_verifier.cpp + LOCAL_MODULE := update_verifier -LOCAL_SHARED_LIBRARIES := libhardware libbase +LOCAL_SHARED_LIBRARIES := libbase libcutils libhardware liblog + +LOCAL_C_INCLUDES += $(LOCAL_PATH)/.. LOCAL_CFLAGS := -Werror include $(BUILD_EXECUTABLE) diff --git a/update_verifier/update_verifier.cpp b/update_verifier/update_verifier.cpp index 0a040c564..93ac605b1 100644 --- a/update_verifier/update_verifier.cpp +++ b/update_verifier/update_verifier.cpp @@ -22,22 +22,121 @@ * It relies on dm-verity to capture any corruption on the partitions being * verified. dm-verity must be in enforcing mode, so that it will reboot the * device on dm-verity failures. When that happens, the bootloader should - * mark the slot as unbootable and stops trying. We should never see a device - * started in dm-verity logging mode but with isSlotMarkedSuccessful equals to - * 0. + * mark the slot as unbootable and stops trying. Other dm-verity modes ( + * for example, veritymode=EIO) are not accepted and simply lead to a + * verification failure. * * The current slot will be marked as having booted successfully if the * verifier reaches the end after the verification. * - * TODO: The actual verification part will be added later after we have the - * A/B OTA package format in place. */ +#include <errno.h> +#include <fcntl.h> +#include <stdio.h> #include <string.h> +#include <string> +#include <vector> + +#include <android-base/file.h> #include <android-base/logging.h> +#include <android-base/parseint.h> +#include <android-base/strings.h> +#include <android-base/unique_fd.h> +#include <cutils/properties.h> #include <hardware/boot_control.h> +constexpr auto CARE_MAP_FILE = "/data/ota_package/care_map.txt"; +constexpr int BLOCKSIZE = 4096; + +static bool read_blocks(const std::string& blk_device_prefix, const std::string& range_str) { + char slot_suffix[PROPERTY_VALUE_MAX]; + property_get("ro.boot.slot_suffix", slot_suffix, ""); + std::string blk_device = blk_device_prefix + std::string(slot_suffix); + android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(blk_device.c_str(), O_RDONLY))); + if (fd.get() == -1) { + PLOG(ERROR) << "Error reading partition " << blk_device; + return false; + } + + // For block range string, first integer 'count' equals 2 * total number of valid ranges, + // followed by 'count' number comma separated integers. Every two integers reprensent a + // block range with the first number included in range but second number not included. + // For example '4,64536,65343,74149,74150' represents: [64536,65343) and [74149,74150). + std::vector<std::string> ranges = android::base::Split(range_str, ","); + size_t range_count; + bool status = android::base::ParseUint(ranges[0].c_str(), &range_count); + if (!status || (range_count == 0) || (range_count % 2 != 0) || + (range_count != ranges.size()-1)) { + LOG(ERROR) << "Error in parsing range string."; + return false; + } + + size_t blk_count = 0; + for (size_t i = 1; i < ranges.size(); i += 2) { + unsigned int range_start, range_end; + bool parse_status = android::base::ParseUint(ranges[i].c_str(), &range_start); + parse_status = parse_status && android::base::ParseUint(ranges[i+1].c_str(), &range_end); + if (!parse_status || range_start >= range_end) { + LOG(ERROR) << "Invalid range pair " << ranges[i] << ", " << ranges[i+1]; + return false; + } + + if (lseek64(fd.get(), static_cast<off64_t>(range_start) * BLOCKSIZE, SEEK_SET) == -1) { + PLOG(ERROR) << "lseek to " << range_start << " failed"; + return false; + } + + size_t size = (range_end - range_start) * BLOCKSIZE; + std::vector<uint8_t> buf(size); + if (!android::base::ReadFully(fd.get(), buf.data(), size)) { + PLOG(ERROR) << "Failed to read blocks " << range_start << " to " << range_end; + return false; + } + blk_count += (range_end - range_start); + } + + LOG(INFO) << "Finished reading " << blk_count << " blocks on " << blk_device; + return true; +} + +static bool verify_image(const std::string& care_map_name) { + android::base::unique_fd care_map_fd(TEMP_FAILURE_RETRY(open(care_map_name.c_str(), O_RDONLY))); + // If the device is flashed before the current boot, it may not have care_map.txt + // in /data/ota_package. To allow the device to continue booting in this situation, + // we should print a warning and skip the block verification. + if (care_map_fd.get() == -1) { + LOG(WARNING) << "Warning: care map " << care_map_name << " not found."; + return true; + } + // Care map file has four lines (two lines if vendor partition is not present): + // First line has the block device name, e.g./dev/block/.../by-name/system. + // Second line holds all ranges of blocks to verify. + // The next two lines have the same format but for vendor partition. + std::string file_content; + if (!android::base::ReadFdToString(care_map_fd.get(), &file_content)) { + LOG(ERROR) << "Error reading care map contents to string."; + return false; + } + + std::vector<std::string> lines; + lines = android::base::Split(android::base::Trim(file_content), "\n"); + if (lines.size() != 2 && lines.size() != 4) { + LOG(ERROR) << "Invalid lines in care_map: found " << lines.size() + << " lines, expecting 2 or 4 lines."; + return false; + } + + for (size_t i = 0; i < lines.size(); i += 2) { + if (!read_blocks(lines[i], lines[i+1])) { + return false; + } + } + + return true; +} + int main(int argc, char** argv) { for (int i = 1; i < argc; i++) { LOG(INFO) << "Started with arg " << i << ": " << argv[i]; @@ -59,12 +158,22 @@ int main(int argc, char** argv) { if (is_successful == 0) { // The current slot has not booted successfully. - - // TODO: Add the actual verification after we have the A/B OTA package - // format in place. - - // TODO: Assert the dm-verity mode. Bootloader should never boot a newly - // flashed slot (isSlotMarkedSuccessful == 0) with dm-verity logging mode. + char verity_mode[PROPERTY_VALUE_MAX]; + if (property_get("ro.boot.veritymode", verity_mode, "") == -1) { + LOG(ERROR) << "Failed to get dm-verity mode."; + return -1; + } else if (strcasecmp(verity_mode, "eio") == 0) { + // We shouldn't see verity in EIO mode if the current slot hasn't booted + // successfully before. Therefore, fail the verification when veritymode=eio. + LOG(ERROR) << "Found dm-verity in EIO mode, skip verification."; + return -1; + } else if (strcmp(verity_mode, "enforcing") != 0) { + LOG(ERROR) << "Unexpected dm-verity mode : " << verity_mode << ", expecting enforcing."; + return -1; + } else if (!verify_image(CARE_MAP_FILE)) { + LOG(ERROR) << "Failed to verify all blocks in care map file."; + return -1; + } int ret = module->markBootSuccessful(module); if (ret != 0) { |