static constexpr int kRecoveryApiVersion = 3; // We define RECOVERY_API_VERSION in Android.mk, which will be picked up by build system and packed // into target_files.zip. Assert the version defined in code and in Android.mk are consistent.
static_assert(kRecoveryApiVersion == RECOVERY_API_VERSION, "Mismatching recovery API versions.");
// Default allocation of progress bar segments to operations static constexpr int VERIFICATION_PROGRESS_TIME = 60; static constexpr float VERIFICATION_PROGRESS_FRACTION = 0.25; // The charater used to separate dynamic fingerprints. e.x. sargo|aosp-sargo staticconstchar* FINGERPRING_SEPARATOR = "|"; static constexpr auto&& RELEASE_KEYS_TAG = "release-keys"; // If brick packages are smaller than |MEMORY_PACKAGE_LIMIT|, read the entire package into memory static constexpr size_t MEMORY_PACKAGE_LIMIT = 1024 * 1024;
for (const std::string& line : android::base::Split(metadata_string, "\n")) {
size_t eq = line.find('='); if (eq != std::string::npos) {
metadata->emplace(android::base::Trim(line.substr(0, eq)),
android::base::Trim(line.substr(eq + 1)));
}
}
returntrue;
}
// Gets the value for the given key in |metadata|. Returns an emtpy string if the key isn't // present. static std::string get_value(const std::map<std::string, std::string>& metadata, const std::string& key) { constauto& it = metadata.find(key); return (it == metadata.end()) ? "" : it->second;
}
static std::string OtaTypeToString(OtaType type) { switch (type) { case OtaType::AB: return"AB"; case OtaType::BLOCK: return"BLOCK"; case OtaType::BRICK: return"BRICK";
}
}
// Read the build.version.incremental of src/tgt from the metadata and log it to last_install. staticvoid ReadSourceTargetBuild(const std::map<std::string, std::string>& metadata,
std::vector<std::string>* log_buffer) { // Examples of the pre-build and post-build strings in metadata: // pre-build-incremental=2943039 // post-build-incremental=2951741 auto source_build = get_value(metadata, "pre-build-incremental"); if (!source_build.empty()) {
log_buffer->push_back("source_build: " + source_build);
}
auto target_build = get_value(metadata, "post-build-incremental"); if (!target_build.empty()) {
log_buffer->push_back("target_build: " + target_build);
}
}
// 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. staticbool CheckAbSpecificMetadata(const std::map<std::string, std::string>& metadata) { // 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"); if (!pkg_pre_build.empty() && pkg_pre_build != device_pre_build) {
LOG(ERROR) << "Package is for source build " << pkg_pre_build << " but expected "
<< device_pre_build; returnfalse;
}
auto device_fingerprint = android::base::GetProperty("ro.build.fingerprint", ""); auto pkg_pre_build_fingerprint = get_value(metadata, "pre-build"); if (!pkg_pre_build_fingerprint.empty() &&
!isInStringList(device_fingerprint, pkg_pre_build_fingerprint, FINGERPRING_SEPARATOR)) {
LOG(ERROR) << "Package is for source build " << pkg_pre_build_fingerprint << " but expected "
<< device_fingerprint; returnfalse;
}
// Check for downgrade version.
int64_t build_timestamp =
android::base::GetIntProperty("ro.build.date.utc", std::numeric_limits<int64_t>::max());
int64_t pkg_post_timestamp = 0; // We allow to full update to the same version we are running, in case there // is a problem with the current copy of that version. auto pkg_post_timestamp_string = get_value(metadata, "post-timestamp"); if (pkg_post_timestamp_string.empty() ||
!android::base::ParseInt(pkg_post_timestamp_string, &pkg_post_timestamp) ||
pkg_post_timestamp < build_timestamp) { if (get_value(metadata, "ota-downgrade") != "yes") {
LOG(ERROR) << "Update package is older than the current build, expected a build " "newer than timestamp "
<< build_timestamp << " but package has timestamp " << pkg_post_timestamp
<< " and downgrade not allowed."; returnfalse;
} if (pkg_pre_build_fingerprint.empty()) {
LOG(ERROR) << "Downgrade package must have a pre-build version set, not allowed."; returnfalse;
}
} constauto post_build = get_value(metadata, "post-build"); constauto build_fingerprint = android::base::Tokenize(post_build, "/"); if (!build_fingerprint.empty()) { constauto& post_build_tag = build_fingerprint.back(); constauto build_tag = android::base::GetProperty("ro.build.tags", ""); if (build_tag != post_build_tag) {
LOG(ERROR) << "Post build-tag " << post_build_tag << " does not match device build tag "
<< build_tag; returnfalse;
}
}
returntrue;
}
bool CheckPackageMetadata(const std::map<std::string, std::string>& metadata, OtaType ota_type) { 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) {
LOG(INFO) << "Skip package metadata check for ota type " << expected_ota_type; returntrue;
}
if (package_ota_type != expected_ota_type) {
LOG(ERROR) << "Unexpected ota package type, expects " << expected_ota_type << ", actual "
<< package_ota_type; returnfalse;
}
auto device = android::base::GetProperty("ro.product.device", ""); auto pkg_device = get_value(metadata, "pre-device"); // device name can be a | separated list, so need to check if (pkg_device.empty() || !isInStringList(device, pkg_device, FINGERPRING_SEPARATOR)) {
LOG(ERROR) << "Package is for product " << pkg_device << " but expected " << device; returnfalse;
}
// We allow the package to not have any serialno; and we also allow it to carry multiple serial // numbers split by "|"; e.g. serialno=serialno1|serialno2|serialno3 ... We will fail the // verification if the device's serialno doesn't match any of these carried numbers.
auto pkg_serial_no = get_value(metadata, "serialno"); if (!pkg_serial_no.empty()) { auto device_serial_no = android::base::GetProperty("ro.serialno", ""); bool serial_number_match = false; for (constauto& number : android::base::Split(pkg_serial_no, "|")) { if (device_serial_no == android::base::Trim(number)) {
serial_number_match = true;
}
} if (!serial_number_match) {
LOG(ERROR) << "Package is for serial " << pkg_serial_no; returnfalse;
}
} elseif (ota_type == OtaType::BRICK) { constauto device_build_tag = android::base::GetProperty("ro.build.tags", ""); if (device_build_tag.empty()) {
LOG(ERROR) << "Unable to determine device build tags, serial number is missing from package. " "Rejecting the brick OTA package."; returnfalse;
} if (device_build_tag == RELEASE_KEYS_TAG) {
LOG(ERROR) << "Device is release key build, serial number is missing from package. " "Rejecting the brick OTA package."; returnfalse;
}
LOG(INFO)
<< "Serial number is missing from brick OTA package, permitting anyway because device is "
<< device_build_tag;
}
if (ota_type == OtaType::AB) { return CheckAbSpecificMetadata(metadata);
}
returntrue;
}
static std::string ExtractPayloadProperties(ZipArchiveHandle zip) { // For A/B updates we extract the payload properties to a buffer and obtain the RAW payload offset // in the zip file. static constexpr constchar* AB_OTA_PAYLOAD_PROPERTIES = "payload_properties.txt";
ZipEntry64 properties_entry; if (FindEntry(zip, AB_OTA_PAYLOAD_PROPERTIES, &properties_entry) != 0) {
LOG(ERROR) << "Failed to find " << AB_OTA_PAYLOAD_PROPERTIES; return {};
} auto properties_entry_length = properties_entry.uncompressed_length; if (properties_entry_length > std::numeric_limits<size_t>::max()) {
LOG(ERROR) << "Failed to extract " << AB_OTA_PAYLOAD_PROPERTIES
<< " because's uncompressed size exceeds size of address space. "
<< properties_entry_length; return {};
}
std::string payload_properties(properties_entry_length, '\0');
int32_t err =
ExtractToMemory(zip, &properties_entry, reinterpret_cast<uint8_t*>(payload_properties.data()),
properties_entry_length); if (err != 0) {
LOG(ERROR) << "Failed to extract " << AB_OTA_PAYLOAD_PROPERTIES << ": " << ErrorCodeString(err); return {};
} return payload_properties;
}
// For A/B updates we extract the payload properties to a buffer and obtain the RAW payload offset // in the zip file. constauto payload_properties = ExtractPayloadProperties(zip); if (payload_properties.empty()) { returnfalse;
}
// When executing the update binary contained in the package, the arguments passed are: // - the version number for this interface // - an FD to which the program can write in order to update the progress bar. // - the name of the package zip file. // - an optional argument "retry" if this update is a retry of a failed update attempt.
*cmd = {
binary_path,
std::to_string(kRecoveryApiVersion),
std::to_string(status_fd),
package,
}; if (retry_count > 0) {
cmd->push_back("retry");
} returntrue;
}
// If the package contains an update binary, extract it and run it. static InstallResult TryUpdateBinary(Package* package, bool* wipe_cache,
std::vector<std::string>* log_buffer, int retry_count, int* max_temperature, Device* device) { auto ui = device->GetUI();
std::map<std::string, std::string> metadata; auto zip = package->GetZipArchiveHandle(); if (!ReadMetadataFromPackage(zip, &metadata)) {
LOG(ERROR) << "Failed to parse metadata in the zip file"; return INSTALL_CORRUPT;
}
constauto current_spl = android::base::GetProperty("ro.build.version.security_patch", ""); if (ViolatesSPLDowngrade(zip, current_spl)) {
LOG(ERROR) << "Denying OTA because it's SPL downgrade"; return INSTALL_ERROR;
}
if (package_is_ab) {
CHECK(package->GetType() == PackageType::kFile);
}
// Verify against the metadata in the package first. Expects A/B metadata if: // Package declares itself as an A/B package // 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)) {
log_buffer->push_back(android::base::StringPrintf("error: %d", kUpdateBinaryCommandFailure)); return INSTALL_ERROR;
}
}
ReadSourceTargetBuild(metadata, log_buffer);
// The updater in child process writes to the pipe to communicate with recovery.
android::base::unique_fd pipe_read, pipe_write; // Explicitly disable O_CLOEXEC using 0 as the flags (last) parameter to Pipe // so that the child updater process will recieve a non-closed fd. if (!android::base::Pipe(&pipe_read, &pipe_write, 0)) {
PLOG(ERROR) << "Failed to create pipe for updater-recovery communication"; return INSTALL_CORRUPT;
}
// The updater-recovery communication protocol. // // progress <frac> <secs> // fill up the next <frac> part of of the progress bar over <secs> seconds. If <secs> is // zero, use `set_progress` commands to manually control the progress of this segment of the // bar. // // set_progress <frac> // <frac> should be between 0.0 and 1.0; sets the progress bar within the segment defined by // the most recent progress command. // // ui_print <string> // display <string> on the screen. // // wipe_cache // a wipe of cache will be performed following a successful installation. // // clear_display // turn off the text display. // // enable_reboot // packages can explicitly request that they want the user to be able to reboot during // installation (useful for debugging packages that don't exit). // // retry_update // updater encounters some issue during the update. It requests a reboot to retry the same // package automatically. // // log <string> // updater requests logging the string (e.g. cause of the failure). //
// Convert the std::string vector to a NULL-terminated char* vector suitable for execv. auto chr_args = StringVectorToNullTerminatedArray(args);
execv(chr_args[0], chr_args.data()); // We shouldn't use LOG/PLOG in the forked process, since they may cause the child process to // hang. This deadlock results from an improperly copied mutex in the ui functions. // (Bug: 34769056)
fprintf(stdout, "E:Can't run %s (%s)\n", chr_args[0], strerror(errno));
_exit(EXIT_FAILURE);
}
pipe_write.reset();
char buffer[1024];
FILE* from_child = android::base::Fdopen(std::move(pipe_read), "r"); while (fgets(buffer, sizeof(buffer), from_child) != nullptr) {
std::string line(buffer);
size_t space = line.find_first_of(" \n");
std::string command(line.substr(0, space)); if (command.empty()) continue;
// Get rid of the leading and trailing space and/or newline.
std::string args = space == std::string::npos ? "" : android::base::Trim(line.substr(space));
if (command == "progress") {
std::vector<std::string> tokens = android::base::Split(args, " "); double fraction; int seconds; if (tokens.size() == 2 && android::base::ParseDouble(tokens[0].c_str(), &fraction) &&
android::base::ParseInt(tokens[1], &seconds)) {
ui->ShowProgress(fraction * (1 - VERIFICATION_PROGRESS_FRACTION), seconds);
} else {
LOG(ERROR) << "invalid \"progress\" parameters: " << line;
}
} elseif (command == "set_progress") {
std::vector<std::string> tokens = android::base::Split(args, " "); double fraction; if (tokens.size() == 1 && android::base::ParseDouble(tokens[0].c_str(), &fraction)) {
ui->SetProgress(fraction);
} else {
LOG(ERROR) << "invalid \"set_progress\" parameters: " << line;
}
} elseif (command == "ui_print") {
ui->PrintOnScreenOnly("%s\n", args.c_str());
fflush(stdout);
} elseif (command == "wipe_cache") {
*wipe_cache = true;
} elseif (command == "clear_display") {
ui->SetBackground(RecoveryUI::NONE);
} elseif (command == "enable_reboot") { // packages can explicitly request that they want the user // to be able to reboot during installation (useful for // debugging packages that don't exit).
ui->SetEnableReboot(true);
} elseif (command == "retry_update") {
retry_update = true;
} elseif (command == "log") { if (!args.empty()) { // Save the logging request from updater and write to last_install later.
log_buffer->push_back(args);
} else {
LOG(ERROR) << "invalid \"log\" parameters: " << line;
}
} else {
LOG(ERROR) << "unknown command [" << command << "]";
}
}
fclose(from_child);
// Verify and install the contents of the package.
ui->Print("Installing update...\n"); if (retry_count > 0) {
ui->Print("Retry attempt: %d\n", retry_count);
}
ui->SetEnableReboot(false); auto result =
TryUpdateBinary(package, wipe_cache, log_buffer, retry_count, max_temperature, device);
ui->SetEnableReboot(true);
ui->Print("\n");
return result;
}
InstallResult InstallPackage(Package* package, const std::string_view package_id, bool should_wipe_cache, int retry_count, Device* device) { auto ui = device->GetUI(); auto start = std::chrono::system_clock::now();
int start_temperature = GetMaxValueFromThermalZone(); int max_temperature = start_temperature;
ui->Print("Finding update package...\n");
LOG(INFO) << "Update package id: " << package_id; if (!package) {
log_buffer.push_back(android::base::StringPrintf("error: %d", kMapFileFailure));
result = INSTALL_CORRUPT;
} elseif (setup_install_mounts() != 0) {
LOG(ERROR) << "failed to set up expected mounts for install; aborting";
result = INSTALL_ERROR;
} else { bool updater_wipe_cache = false;
result = VerifyAndInstallPackage(package, &updater_wipe_cache, &log_buffer, retry_count,
&max_temperature, device);
should_wipe_cache = should_wipe_cache || updater_wipe_cache;
}
// Measure the time spent to apply OTA update in seconds.
std::chrono::duration<double> duration = std::chrono::system_clock::now() - start; int time_total = static_cast<int>(duration.count());
bool has_cache = volume_for_mount_point("/cache") != nullptr; // Skip logging the uncrypt_status on devices without /cache. if (has_cache) { static constexpr constchar* UNCRYPT_STATUS = "/cache/recovery/uncrypt_status"; if (ensure_path_mounted(UNCRYPT_STATUS) != 0) {
LOG(WARNING) << "Can't mount " << UNCRYPT_STATUS;
} else {
std::string uncrypt_status; if (!android::base::ReadFileToString(UNCRYPT_STATUS, &uncrypt_status)) {
PLOG(WARNING) << "failed to read uncrypt status";
} elseif (!android::base::StartsWith(uncrypt_status, "uncrypt_")) {
LOG(WARNING) << "corrupted uncrypt_status: " << uncrypt_status;
} else {
log_buffer.push_back(android::base::Trim(uncrypt_status));
}
}
}
// The first two lines need to be the package name and install result.
std::vector<std::string> log_header = {
std::string(package_id),
result == INSTALL_SUCCESS ? "1" : "0", "time_total: " + std::to_string(time_total), "retry: " + std::to_string(retry_count),
};
int end_temperature = GetMaxValueFromThermalZone();
max_temperature = std::max(end_temperature, max_temperature); if (start_temperature > 0) {
log_buffer.push_back("temperature_start: " + std::to_string(start_temperature));
} if (end_temperature > 0) {
log_buffer.push_back("temperature_end: " + std::to_string(end_temperature));
} if (max_temperature > 0) {
log_buffer.push_back("temperature_max: " + std::to_string(max_temperature));
}
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