Merge "Change tzdatacheck to account for bundle format changes" (6540dfef) · Commits · e / os / android_system_core

tzdatacheck/tzdatacheck.cpp

+209 −71

Original line number	Diff line number	Diff line
		@@ -14,6 +14,7 @@
		* limitations under the License.
		*/

		#include <ctype.h>
		#include <errno.h>
		#include <ftw.h>
		#include <libgen.h>
		@@ -29,47 +30,105 @@

		#include "android-base/logging.h"

		static const char* BUNDLE_VERSION_FILENAME = "/bundle_version";
		// bundle_version is an ASCII file consisting of 17 bytes in the form: AAA.BBB\|CCCCC\|DDD
		// AAA.BBB is the major/minor version of the bundle format (e.g. 001.001),
		// CCCCC is the rules version (e.g. 2016g)
		// DDD is the android revision for this rules version to allow for bundle corrections (e.g. 001)
		// We only need the first 13 to determine if it is suitable for the device.
		static const int BUNDLE_VERSION_LENGTH = 13;
		// The major version of the bundle format supported by this code as a null-terminated char[].
		static const char REQUIRED_BUNDLE_VERSION[] = "001";
		static const size_t REQUIRED_BUNDLE_VERSION_LEN = sizeof(REQUIRED_BUNDLE_VERSION) - 1; // exclude \0
		// The length of the IANA rules version bytes. e.g. 2016a
		static const size_t RULES_VERSION_LEN = 5;
		// Bundle version bytes are: AAA.BBB\|CCCCC - the rules version is CCCCC
		static const size_t BUNDLE_VERSION_RULES_IDX = 8;

		static const char* TZDATA_FILENAME = "/tzdata";
		// tzdata file header (as much as we need for the version):
		// byte[11] tzdata_version -- e.g. "tzdata2012f"
		static const int TZ_HEADER_LENGTH = 11;
		// The major version of the bundle format supported by this code as a null-terminated char[].
		static const char TZ_DATA_HEADER_PREFIX[] = "tzdata";
		static const size_t TZ_DATA_HEADER_PREFIX_LEN = sizeof(TZ_DATA_HEADER_PREFIX) - 1; // exclude \0


		static void usage() {
		std::cerr << "Usage: tzdatacheck SYSTEM_TZ_DIR DATA_TZ_DIR\n"
		"\n"
		"Compares the headers of two tzdata files. If the one in SYSTEM_TZ_DIR is the\n"
		"same or a higher version than the one in DATA_TZ_DIR the DATA_TZ_DIR is renamed\n"
		"and then deleted.\n";
		"Checks whether any timezone update bundle in DATA_TZ_DIR is compatible with the\n"
		"current Android release and better than or the same as base system timezone rules in\n"
		"SYSTEM_TZ_DIR. If the timezone rules in SYSTEM_TZ_DIR are a higher version than the\n"
		"one in DATA_TZ_DIR the DATA_TZ_DIR is renamed and then deleted.\n";
		exit(1);
		}

		/*
		* Opens a file and fills headerBytes with the first byteCount bytes from the file. It is a fatal
		* error if the file is too small or cannot be opened. If the file does not exist false is returned.
		* Opens a file and fills buffer with the first byteCount bytes from the file.
		* If the file does not exist or cannot be opened or is too short then false is returned.
		* If the bytes were read successfully then true is returned.
		*/
		static bool readHeader(const std::string& tzDataFileName, char* headerBytes, size_t byteCount) {
		FILE* tzDataFile = fopen(tzDataFileName.c_str(), "r");
		if (tzDataFile == nullptr) {
		if (errno == ENOENT) {
		return false;
		} else {
		PLOG(FATAL) << "Error opening tzdata file " << tzDataFileName;
		static bool readBytes(const std::string& fileName, char* buffer, size_t byteCount) {
		FILE* file = fopen(fileName.c_str(), "r");
		if (file == nullptr) {
		if (errno != ENOENT) {
		PLOG(WARNING) << "Error opening file " << fileName;
		}
		return false;
		}
		size_t bytesRead = fread(headerBytes, 1, byteCount, tzDataFile);
		size_t bytesRead = fread(buffer, 1, byteCount, file);
		fclose(file);
		if (bytesRead != byteCount) {
		LOG(FATAL) << tzDataFileName << " is too small. " << byteCount << " bytes required";
		LOG(WARNING) << fileName << " is too small. " << byteCount << " bytes required";
		return false;
		}
		fclose(tzDataFile);
		return true;
		}

		/* Checks the contents of headerBytes. It is a fatal error if it not a tzdata header. */
		static void checkValidHeader(const std::string& fileName, char* headerBytes) {
		/*
		* Checks the contents of headerBytes. Returns true if it is valid (starts with "tzdata"), false
		* otherwise.
		*/
		static bool checkValidTzDataHeader(const std::string& fileName, const char* headerBytes) {
		if (strncmp("tzdata", headerBytes, 6) != 0) {
		LOG(FATAL) << fileName << " does not start with the expected bytes (tzdata)";
		LOG(WARNING) << fileName << " does not start with the expected bytes (tzdata)";
		return false;
		}
		return true;
		}

		static bool checkDigits(const char* buffer, const size_t count, size_t* i) {
		for (size_t j = 0; j < count; j++) {
		char toCheck = buffer[(*i)++];
		if (!isdigit(toCheck)) {
		return false;
		}
		}
		return true;
		}

		static bool checkValidBundleVersion(const char* buffer) {
		// See BUNDLE_VERSION_LENGTH comments above for a description of the format.
		size_t i = 0;
		if (!checkDigits(buffer, 3, &i)) {
		return false;
		}
		if (buffer[i++] != '.') {
		return false;
		}
		if (!checkDigits(buffer, 3, &i)) {
		return false;
		}
		if (buffer[i++] != '\|') {
		return false;
		}
		if (!checkDigits(buffer, 4, &i)) {
		return false;
		}
		// Ignore the last character. It is assumed to be a letter but we don't check because it's not
		// obvious what would happen at 'z'.
		return true;
		}

		/* Return the parent directory of dirName. */
		@@ -103,9 +162,24 @@ static int deleteFn(const char* fpath, const struct stat*, int typeflag, struct
		return 0;
		}

		enum PathStatus { ERR, NONE, IS_DIR, NOT_DIR };

		static PathStatus checkPath(const std::string& path) {
		struct stat buf;
		if (stat(path.c_str(), &buf) != 0) {
		if (errno != ENOENT) {
		PLOG(WARNING) << "Unable to stat " << path;
		return ERR;
		}
		return NONE;
		}
		return S_ISDIR(buf.st_mode) ? IS_DIR : NOT_DIR;
		}

		/*
		* Deletes dirToDelete and returns true if it is successful in removing or moving the directory out
		* of the way. If dirToDelete does not exist this function does nothing and returns true.
		* of the way. If dirToDelete does not exist this function does nothing and returns true. If
		* dirToDelete is not a directory or cannot be accessed this method returns false.
		*
		* During deletion, this function first renames the directory to a temporary name. If the temporary
		* directory cannot be created, or the directory cannot be renamed, false is returned. After the
		@@ -114,23 +188,18 @@ static int deleteFn(const char* fpath, const struct stat*, int typeflag, struct
		*/
		static bool deleteDir(const std::string& dirToDelete) {
		// Check whether the dir exists.
		struct stat buf;
		if (stat(dirToDelete.c_str(), &buf) == 0) {
		if (!S_ISDIR(buf.st_mode)) {
		LOG(WARNING) << dirToDelete << " is not a directory";
		return false;
		}
		} else {
		if (errno == ENOENT) {
		PLOG(INFO) << "Directory does not exist: " << dirToDelete;
		int pathStatus = checkPath(dirToDelete);
		if (pathStatus == NONE) {
		LOG(INFO) << "Path " << dirToDelete << " does not exist";
		return true;
		} else {
		PLOG(WARNING) << "Unable to stat " << dirToDelete;
		return false;
		}
		if (pathStatus != IS_DIR) {
		LOG(WARNING) << "Path " << dirToDelete << " failed to stat() or is not a directory.";
		return false;
		}

		// First, rename dirToDelete.

		std::string tempDirNameTemplate = getParentDir(dirToDelete);
		tempDirNameTemplate += "/tempXXXXXX";

		@@ -142,7 +211,7 @@ static bool deleteDir(const std::string& dirToDelete) {
		return false;
		}

		// Rename dirToDelete to tempDirName.
		// Rename dirToDelete to tempDirName (replacing the empty tempDirName directory created above).
		int rc = rename(dirToDelete.c_str(), &tempDirName[0]);
		if (rc == -1) {
		PLOG(WARNING) << "Unable to rename directory from " << dirToDelete << " to "
		@@ -151,6 +220,7 @@ static bool deleteDir(const std::string& dirToDelete) {
		}

		// Recursively delete contents of tempDirName.

		rc = nftw(&tempDirName[0], deleteFn, 10 /* openFiles */,
		FTW_DEPTH \| FTW_MOUNT \| FTW_PHYS);
		if (rc == -1) {
		@@ -159,10 +229,37 @@ static bool deleteDir(const std::string& dirToDelete) {
		return true;
		}

		/*
		* Deletes the ConfigInstaller metadata directory.
		* TODO(nfuller). http://b/31008728 Remove this when ConfigInstaller is no longer used.
		*/
		static void deleteConfigUpdaterMetadataDir(const char* dataZoneInfoDir) {
		// Delete the update metadata
		std::string dataUpdatesDirName(dataZoneInfoDir);
		dataUpdatesDirName += "/updates";
		LOG(INFO) << "Removing: " << dataUpdatesDirName;
		bool deleted = deleteDir(dataUpdatesDirName);
		if (!deleted) {
		LOG(WARNING) << "Deletion of install metadata " << dataUpdatesDirName
		<< " was not successful";
		}
		}

		/*
		* Deletes the timezone update bundle directory.
		*/
		static void deleteUpdateBundleDir(std::string& bundleDirName) {
		LOG(INFO) << "Removing: " << bundleDirName;
		bool deleted = deleteDir(bundleDirName);
		if (!deleted) {
		LOG(WARNING) << "Deletion of bundle dir " << bundleDirName << " was not successful";
		}
		}

		/*
		* After a platform update it is likely that timezone data found on the system partition will be
		* newer than the version found in the data partition. This tool detects this case and removes the
		* version in /data along with any update metadata.
		* version in /data.
		*
		* Note: This code is related to code in com.android.server.updates.TzDataInstallReceiver. The
		* paths for the metadata and current timezone data must match.
		@@ -175,62 +272,103 @@ static bool deleteDir(const std::string& dirToDelete) {
		int main(int argc, char* argv[]) {
		if (argc != 3) {
		usage();
		return 1;
		}

		const char* systemZoneInfoDir = argv[1];
		const char* dataZoneInfoDir = argv[2];

		// Check the bundle directory exists. If it does not, exit quickly: nothing to do.
		std::string dataCurrentDirName(dataZoneInfoDir);
		dataCurrentDirName += "/current";
		std::string dataTzDataFileName(dataCurrentDirName);
		dataTzDataFileName += TZDATA_FILENAME;
		int dataCurrentDirStatus = checkPath(dataCurrentDirName);
		if (dataCurrentDirStatus == NONE) {
		LOG(INFO) << "timezone bundle dir " << dataCurrentDirName
		<< " does not exist. No action required.";
		return 0;
		}
		// If the bundle directory path is not a directory or we can't stat() the path, exit with a
		// warning: either there's a problem accessing storage or the world is not as it should be;
		// nothing to do.
		if (dataCurrentDirStatus != IS_DIR) {
		LOG(WARNING) << "Current bundle dir " << dataCurrentDirName
		<< " could not be accessed or is not a directory. result=" << dataCurrentDirStatus;
		return 2;
		}

		std::vector<char> dataTzDataHeader;
		dataTzDataHeader.reserve(TZ_HEADER_LENGTH);
		// Check the installed bundle version.
		std::string bundleVersionFileName(dataCurrentDirName);
		bundleVersionFileName += BUNDLE_VERSION_FILENAME;
		std::vector<char> bundleVersion;
		bundleVersion.reserve(BUNDLE_VERSION_LENGTH);
		bool bundleVersionReadOk =
		readBytes(bundleVersionFileName, bundleVersion.data(), BUNDLE_VERSION_LENGTH);
		if (!bundleVersionReadOk) {
		LOG(WARNING) << "bundle version file " << bundleVersionFileName
		<< " does not exist or is too short. Deleting bundle dir.";
		// Implies the contents of the data partition is corrupt in some way. Try to clean up.
		deleteConfigUpdaterMetadataDir(dataZoneInfoDir);
		deleteUpdateBundleDir(dataCurrentDirName);
		return 3;
		}

		bool dataFileExists = readHeader(dataTzDataFileName, dataTzDataHeader.data(), TZ_HEADER_LENGTH);
		if (!dataFileExists) {
		LOG(INFO) << "tzdata file " << dataTzDataFileName << " does not exist. No action required.";
		return 0;
		if (!checkValidBundleVersion(bundleVersion.data())) {
		LOG(WARNING) << "bundle version file " << bundleVersionFileName
		<< " is not valid. Deleting bundle dir.";
		// Implies the contents of the data partition is corrupt in some way. Try to clean up.
		deleteConfigUpdaterMetadataDir(dataZoneInfoDir);
		deleteUpdateBundleDir(dataCurrentDirName);
		return 4;
		}
		checkValidHeader(dataTzDataFileName, dataTzDataHeader.data());

		// Check the first 3 bytes of the bundleVersionHeader: these are the major version (e.g. 001).
		// It must match exactly to be ok. The minor version is currently ignored.
		if (strncmp(&bundleVersion[0], REQUIRED_BUNDLE_VERSION, REQUIRED_BUNDLE_VERSION_LEN) != 0) {
		LOG(INFO) << "bundle version file " << bundleVersionFileName
		<< " is not the required version " << REQUIRED_BUNDLE_VERSION
		<< ". Deleting bundle dir.";
		// This shouldn't happen with 001, but it in future, this will imply there has been an OTA
		// and the installed bundle is not compatible with the new version of Android. Remove the
		// installed bundle.
		deleteConfigUpdaterMetadataDir(dataZoneInfoDir);
		deleteUpdateBundleDir(dataCurrentDirName);
		return 5;
		}

		// Read the system rules version out of the /system tzdata file.
		std::string systemTzDataFileName(systemZoneInfoDir);
		systemTzDataFileName += TZDATA_FILENAME;
		std::vector<char> systemTzDataHeader;
		systemTzDataHeader.reserve(TZ_HEADER_LENGTH);
		bool systemFileExists =
		readHeader(systemTzDataFileName, systemTzDataHeader.data(), TZ_HEADER_LENGTH);
		readBytes(systemTzDataFileName, systemTzDataHeader.data(), TZ_HEADER_LENGTH);
		if (!systemFileExists) {
		LOG(FATAL) << systemTzDataFileName << " does not exist or could not be opened";
		// Implies the contents of the system partition is corrupt in some way. Nothing we can do.
		LOG(WARNING) << systemTzDataFileName << " does not exist or could not be opened";
		return 6;
		}
		checkValidHeader(systemTzDataFileName, systemTzDataHeader.data());

		if (strncmp(&systemTzDataHeader[0], &dataTzDataHeader[0], TZ_HEADER_LENGTH) < 0) {
		LOG(INFO) << "tzdata file " << dataTzDataFileName << " is the newer than "
		<< systemTzDataFileName << ". No action required.";
		} else {
		// We have detected the case this tool is intended to prevent. Go fix it.
		LOG(INFO) << "tzdata file " << dataTzDataFileName << " is the same as or older than "
		<< systemTzDataFileName << "; fixing...";

		// Delete the update metadata
		std::string dataUpdatesDirName(dataZoneInfoDir);
		dataUpdatesDirName += "/updates";
		LOG(INFO) << "Removing: " << dataUpdatesDirName;
		bool deleted = deleteDir(dataUpdatesDirName);
		if (!deleted) {
		LOG(WARNING) << "Deletion of install metadata " << dataUpdatesDirName
		<< " was not successful";
		if (!checkValidTzDataHeader(systemTzDataFileName, systemTzDataHeader.data())) {
		// Implies the contents of the system partition is corrupt in some way. Nothing we can do.
		LOG(WARNING) << systemTzDataFileName << " does not have a valid header.";
		return 7;
		}

		// Delete the TZ data
		LOG(INFO) << "Removing: " << dataCurrentDirName;
		deleted = deleteDir(dataCurrentDirName);
		if (!deleted) {
		LOG(WARNING) << "Deletion of tzdata " << dataCurrentDirName << " was not successful";
		}
		// Compare the bundle rules version against the system rules version.
		if (strncmp(
		&systemTzDataHeader[TZ_DATA_HEADER_PREFIX_LEN],
		&bundleVersion[BUNDLE_VERSION_RULES_IDX],
		RULES_VERSION_LEN) <= 0) {
		LOG(INFO) << "Found an installed bundle but it is valid. No action taken.";
		// Implies there is an installed update, but it is good.
		return 0;
		}

		// Implies there has been an OTA and the system version of the timezone rules is now newer
		// than the version installed in /data. Remove the installed bundle.
		LOG(INFO) << "timezone bundle in " << dataCurrentDirName << " is older than data in "
		<< systemTzDataFileName << "; fixing...";

		deleteConfigUpdaterMetadataDir(dataZoneInfoDir);
		deleteUpdateBundleDir(dataCurrentDirName);
		return 0;
		}