recovery: allow A/B updater to downgrade (1b5452bc) · Commits · e / os / android_bootable_recovery

install/include/install/install.h

+2 −1

Original line number	Diff line number	Diff line
		@@ -62,7 +62,8 @@ bool ReadMetadataFromPackage(ZipArchiveHandle zip, std::map<std::string, std::st
		// Checks if the metadata in the OTA package has expected values. Mandatory checks: ota-type,
		// pre-device and serial number (if presents). A/B OTA specific checks: pre-build version,
		// fingerprint, timestamp.
		bool CheckPackageMetadata(const std::map<std::string, std::string>& metadata, OtaType ota_type);
		bool CheckPackageMetadata(const std::map<std::string, std::string>& metadata, OtaType ota_type,
		RecoveryUI* ui);

		// Ensures the path to the update package is mounted. Also set the \|should_use_fuse\| to true if the
		// package stays on a removable media.

install/install.cpp

+16 −8

Original line number	Diff line number	Diff line
		@@ -62,6 +62,7 @@
		using namespace std::chrono_literals;

		bool ask_to_continue_unverified(Device* device);
		bool ask_to_continue_downgrade(Device* device);

		static constexpr int kRecoveryApiVersion = 3;
		// We define RECOVERY_API_VERSION in Android.mk, which will be picked up by build system and packed
		@@ -145,7 +146,8 @@ static void ReadSourceTargetBuild(const std::map<std::string, std::string>& meta
		// Checks the build version, fingerprint and timestamp in the metadata of the A/B package.
		// Downgrading is not allowed unless explicitly enabled in the package and only for
		// incremental packages.
		static bool CheckAbSpecificMetadata(const std::map<std::string, std::string>& metadata) {
		static bool CheckAbSpecificMetadata(const std::map<std::string, std::string>& metadata,
		RecoveryUI* ui) {
		// Incremental updates should match the current build.
		auto device_pre_build = android::base::GetProperty("ro.build.version.incremental", "");
		auto pkg_pre_build = get_value(metadata, "pre-build-incremental");
		@@ -165,6 +167,7 @@ static bool CheckAbSpecificMetadata(const std::map<std::string, std::string>& me
		}

		// Check for downgrade version.
		bool undeclared_downgrade = false;
		int64_t build_timestamp =
		android::base::GetIntProperty("ro.build.date.utc", std::numeric_limits<int64_t>::max());
		int64_t pkg_post_timestamp = 0;
		@@ -179,18 +182,23 @@ static bool CheckAbSpecificMetadata(const std::map<std::string, std::string>& me
		"newer than timestamp "
		<< build_timestamp << " but package has timestamp " << pkg_post_timestamp
		<< " and downgrade not allowed.";
		return false;
		}
		if (pkg_pre_build_fingerprint.empty()) {
		undeclared_downgrade = true;
		} else if (pkg_pre_build_fingerprint.empty()) {
		LOG(ERROR) << "Downgrade package must have a pre-build version set, not allowed.";
		return false;
		undeclared_downgrade = true;
		}
		}

		if (undeclared_downgrade &&
		!(ui->IsTextVisible() && ask_to_continue_downgrade(ui->GetDevice()))) {
		return false;
		}

		return true;
		}

		bool CheckPackageMetadata(const std::map<std::string, std::string>& metadata, OtaType ota_type) {
		bool CheckPackageMetadata(const std::map<std::string, std::string>& metadata, OtaType ota_type,
		RecoveryUI* ui) {
		auto package_ota_type = get_value(metadata, "ota-type");
		auto expected_ota_type = OtaTypeToString(ota_type);
		if (ota_type != OtaType::AB && ota_type != OtaType::BRICK) {
		@@ -231,7 +239,7 @@ bool CheckPackageMetadata(const std::map<std::string, std::string>& metadata, Ot
		}

		if (ota_type == OtaType::AB) {
		return CheckAbSpecificMetadata(metadata);
		return CheckAbSpecificMetadata(metadata, ui);
		}

		return true;
		@@ -362,7 +370,7 @@ static InstallResult TryUpdateBinary(Package* package, bool* wipe_cache,
		// Package does not declare itself as an A/B package, but device only supports A/B;
		// still calls CheckPackageMetadata to get a meaningful error message.
		if (package_is_ab \|\| device_only_supports_ab) {
		if (!CheckPackageMetadata(metadata, OtaType::AB)) {
		if (!CheckPackageMetadata(metadata, OtaType::AB, ui)) {
		log_buffer->push_back(android::base::StringPrintf("error: %d", kUpdateBinaryCommandFailure));
		return INSTALL_ERROR;
		}

install/wipe_device.cpp

+1 −1

Original line number	Diff line number	Diff line
		@@ -169,7 +169,7 @@ static bool CheckWipePackage(Package* wipe_package, RecoveryUI* ui) {
		return false;
		}

		return CheckPackageMetadata(metadata, OtaType::BRICK);
		return CheckPackageMetadata(metadata, OtaType::BRICK, ui);
		}

		bool WipeAbDevice(Device* device, size_t wipe_package_size) {

recovery.cpp

+9 −0

Original line number	Diff line number	Diff line
		@@ -178,6 +178,15 @@ bool ask_to_continue_unverified(Device* device) {
		}
		}

		bool ask_to_continue_downgrade(Device* device) {
		if (get_build_type() == "user") {
		return false;
		} else {
		device->GetUI()->SetProgressType(RecoveryUI::EMPTY);
		return yes_no(device, "This package will downgrade your system", "Install anyway?");
		}
		}

		static bool ask_to_wipe_data(Device* device) {
		std::vector<std::string> headers{ "Format user data?", "This includes internal storage.", "THIS CANNOT BE UNDONE!" };
		std::vector<std::string> items{ " Cancel", " Format data" };