tzdatacheck/tzdatacheck.cpp - android-core - Git at Google

 /*
  * Copyright (C) 2015 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include <errno.h>
 #include <ftw.h>
 #include <libgen.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 #include <iostream>
 #include <memory>
 #include <string>
 #include <vector>

 #include "android-base/logging.h"

 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;

 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";
     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.
  * 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;
         }
     }
     size_t bytesRead = fread(headerBytes, 1, byteCount, tzDataFile);
     if (bytesRead != byteCount) {
         LOG(FATAL) << tzDataFileName << " is too small. " << byteCount << " bytes required";
     }
     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) {
     if (strncmp("tzdata", headerBytes, 6) != 0) {
         LOG(FATAL) << fileName << " does not start with the expected bytes (tzdata)";
     }
 }

 /* Return the parent directory of dirName. */
 static std::string getParentDir(const std::string& dirName) {
     std::unique_ptr<char> mutable_dirname(strdup(dirName.c_str()));
     return dirname(mutable_dirname.get());
 }

 /* Deletes a single file, symlink or directory. Called from nftw(). */
 static int deleteFn(const char* fpath, const struct stat*, int typeflag, struct FTW*) {
     LOG(DEBUG) << "Inspecting " << fpath;
     switch (typeflag) {
     case FTW_F:
     case FTW_SL:
         LOG(DEBUG) << "Unlinking " << fpath;
         if (unlink(fpath)) {
             PLOG(WARNING) << "Failed to unlink file/symlink " << fpath;
         }
         break;
     case FTW_D:
     case FTW_DP:
         LOG(DEBUG) << "Removing dir " << fpath;
         if (rmdir(fpath)) {
             PLOG(WARNING) << "Failed to remove dir " << fpath;
         }
         break;
     default:
         LOG(WARNING) << "Unsupported file type " << fpath << ": " << typeflag;
         break;
     }
     return 0;
 }

 /*
  * 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.
  *
  * 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
  * rename, deletion of files and subdirs beneath the directory is performed on a "best effort"
  * basis. Symlinks beneath the directory are not followed.
  */
 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;
           return true;
       } else {
           PLOG(WARNING) << "Unable to stat " << dirToDelete;
           return false;
       }
     }

     // First, rename dirToDelete.
     std::string tempDirNameTemplate = getParentDir(dirToDelete);
     tempDirNameTemplate += "/tempXXXXXX";

     // Create an empty directory with the temporary name. For this we need a non-const char*.
     std::vector<char> tempDirName(tempDirNameTemplate.length() + 1);
     strcpy(&tempDirName[0], tempDirNameTemplate.c_str());
     if (mkdtemp(&tempDirName[0]) == nullptr) {
         PLOG(WARNING) << "Unable to create a temporary directory: " << tempDirNameTemplate;
         return false;
     }

     // Rename dirToDelete to tempDirName.
     int rc = rename(dirToDelete.c_str(), &tempDirName[0]);
     if (rc == -1) {
         PLOG(WARNING) << "Unable to rename directory from " << dirToDelete << " to "
                 << &tempDirName[0];
         return false;
     }

     // Recursively delete contents of tempDirName.
     rc = nftw(&tempDirName[0], deleteFn, 10 /* openFiles */,
             FTW_DEPTH | FTW_MOUNT | FTW_PHYS);
     if (rc == -1) {
         LOG(INFO) << "Could not delete directory: " << &tempDirName[0];
     }
     return true;
 }

 /*
  * 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.
  *
  * Note: This code is related to code in com.android.server.updates.TzDataInstallReceiver. The
  * paths for the metadata and current timezone data must match.
  *
  * Typically on device the two args will be:
  *   /system/usr/share/zoneinfo /data/misc/zoneinfo
  *
  * See usage() for usage notes.
  */
 int main(int argc, char* argv[]) {
     if (argc != 3) {
         usage();
     }

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

     std::string dataCurrentDirName(dataZoneInfoDir);
     dataCurrentDirName += "/current";
     std::string dataTzDataFileName(dataCurrentDirName);
     dataTzDataFileName += TZDATA_FILENAME;

     std::vector<char> dataTzDataHeader;
     dataTzDataHeader.reserve(TZ_HEADER_LENGTH);

     bool dataFileExists = readHeader(dataTzDataFileName, dataTzDataHeader.data(), TZ_HEADER_LENGTH);
     if (!dataFileExists) {
         LOG(INFO) << "tzdata file " << dataTzDataFileName << " does not exist. No action required.";
         return 0;
     }
     checkValidHeader(dataTzDataFileName, dataTzDataHeader.data());

     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);
     if (!systemFileExists) {
         LOG(FATAL) << systemTzDataFileName << " does not exist or could not be opened";
     }
     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";
         }

         // Delete the TZ data
         LOG(INFO) << "Removing: " << dataCurrentDirName;
         deleted = deleteDir(dataCurrentDirName);
         if (!deleted) {
             LOG(WARNING) << "Deletion of tzdata " << dataCurrentDirName << " was not successful";
         }
     }

     return 0;
 }
	/*
	* Copyright (C) 2015 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include <errno.h>
	#include <ftw.h>
	#include <libgen.h>
	#include <stdarg.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <unistd.h>
	#include <iostream>
	#include <memory>
	#include <string>
	#include <vector>

	#include "android-base/logging.h"

	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;

	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";
	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.
	* 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;
	}
	}
	size_t bytesRead = fread(headerBytes, 1, byteCount, tzDataFile);
	if (bytesRead != byteCount) {
	LOG(FATAL) << tzDataFileName << " is too small. " << byteCount << " bytes required";
	}
	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) {
	if (strncmp("tzdata", headerBytes, 6) != 0) {
	LOG(FATAL) << fileName << " does not start with the expected bytes (tzdata)";
	}
	}

	/* Return the parent directory of dirName. */
	static std::string getParentDir(const std::string& dirName) {
	std::unique_ptr<char> mutable_dirname(strdup(dirName.c_str()));
	return dirname(mutable_dirname.get());
	}

	/* Deletes a single file, symlink or directory. Called from nftw(). */
	static int deleteFn(const char* fpath, const struct stat, int typeflag, struct FTW) {
	LOG(DEBUG) << "Inspecting " << fpath;
	switch (typeflag) {
	case FTW_F:
	case FTW_SL:
	LOG(DEBUG) << "Unlinking " << fpath;
	if (unlink(fpath)) {
	PLOG(WARNING) << "Failed to unlink file/symlink " << fpath;
	}
	break;
	case FTW_D:
	case FTW_DP:
	LOG(DEBUG) << "Removing dir " << fpath;
	if (rmdir(fpath)) {
	PLOG(WARNING) << "Failed to remove dir " << fpath;
	}
	break;
	default:
	LOG(WARNING) << "Unsupported file type " << fpath << ": " << typeflag;
	break;
	}
	return 0;
	}

	/*
	* 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.
	*
	* 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
	* rename, deletion of files and subdirs beneath the directory is performed on a "best effort"
	* basis. Symlinks beneath the directory are not followed.
	*/
	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;
	return true;
	} else {
	PLOG(WARNING) << "Unable to stat " << dirToDelete;
	return false;
	}
	}

	// First, rename dirToDelete.
	std::string tempDirNameTemplate = getParentDir(dirToDelete);
	tempDirNameTemplate += "/tempXXXXXX";

	// Create an empty directory with the temporary name. For this we need a non-const char*.
	std::vector<char> tempDirName(tempDirNameTemplate.length() + 1);
	strcpy(&tempDirName[0], tempDirNameTemplate.c_str());
	if (mkdtemp(&tempDirName[0]) == nullptr) {
	PLOG(WARNING) << "Unable to create a temporary directory: " << tempDirNameTemplate;
	return false;
	}

	// Rename dirToDelete to tempDirName.
	int rc = rename(dirToDelete.c_str(), &tempDirName[0]);
	if (rc == -1) {
	PLOG(WARNING) << "Unable to rename directory from " << dirToDelete << " to "
	<< &tempDirName[0];
	return false;
	}

	// Recursively delete contents of tempDirName.
	rc = nftw(&tempDirName[0], deleteFn, 10 /* openFiles */,
	FTW_DEPTH \| FTW_MOUNT \| FTW_PHYS);
	if (rc == -1) {
	LOG(INFO) << "Could not delete directory: " << &tempDirName[0];
	}
	return true;
	}

	/*
	* 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.
	*
	* Note: This code is related to code in com.android.server.updates.TzDataInstallReceiver. The
	* paths for the metadata and current timezone data must match.
	*
	* Typically on device the two args will be:
	* /system/usr/share/zoneinfo /data/misc/zoneinfo
	*
	* See usage() for usage notes.
	*/
	int main(int argc, char* argv[]) {
	if (argc != 3) {
	usage();
	}

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

	std::string dataCurrentDirName(dataZoneInfoDir);
	dataCurrentDirName += "/current";
	std::string dataTzDataFileName(dataCurrentDirName);
	dataTzDataFileName += TZDATA_FILENAME;

	std::vector<char> dataTzDataHeader;
	dataTzDataHeader.reserve(TZ_HEADER_LENGTH);

	bool dataFileExists = readHeader(dataTzDataFileName, dataTzDataHeader.data(), TZ_HEADER_LENGTH);
	if (!dataFileExists) {
	LOG(INFO) << "tzdata file " << dataTzDataFileName << " does not exist. No action required.";
	return 0;
	}
	checkValidHeader(dataTzDataFileName, dataTzDataHeader.data());

	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);
	if (!systemFileExists) {
	LOG(FATAL) << systemTzDataFileName << " does not exist or could not be opened";
	}
	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";
	}

	// Delete the TZ data
	LOG(INFO) << "Removing: " << dataCurrentDirName;
	deleted = deleteDir(dataCurrentDirName);
	if (!deleted) {
	LOG(WARNING) << "Deletion of tzdata " << dataCurrentDirName << " was not successful";
	}
	}

	return 0;
	}