Move system/core/tzdatacheck to system/timezone

Move system/core/tzdatacheck to system/timezone.

Test: make droid
Bug: 31008728
Change-Id: I193767715956cb6076b7ec4a5240d4883a171fbf
diff --git a/tzdatacheck/Android.bp b/tzdatacheck/Android.bp
deleted file mode 100644
index 00ad141..0000000
--- a/tzdatacheck/Android.bp
+++ /dev/null
@@ -1,14 +0,0 @@
-// ========================================================
-// Executable
-// ========================================================
-cc_binary {
-    name: "tzdatacheck",
-    host_supported: true,
-    srcs: ["tzdatacheck.cpp"],
-    shared_libs: [
-        "libbase",
-        "libcutils",
-        "liblog",
-    ],
-    cflags: ["-Werror"],
-}
diff --git a/tzdatacheck/tzdatacheck.cpp b/tzdatacheck/tzdatacheck.cpp
deleted file mode 100644
index 7b8d5c7..0000000
--- a/tzdatacheck/tzdatacheck.cpp
+++ /dev/null
@@ -1,601 +0,0 @@
-/*
- * 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 <ctype.h>
-#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"
-
-// The name of the directory that holds a staged time zone update distro. If this exists it should
-// replace the one in CURRENT_DIR_NAME.
-// See also libcore.tzdata.update2.TimeZoneDistroInstaller.
-static const char* STAGED_DIR_NAME = "/staged";
-
-// The name of the directory that holds the (optional) installed time zone update distro.
-// See also libcore.tzdata.update2.TimeZoneDistroInstaller.
-static const char* CURRENT_DIR_NAME = "/current";
-
-// The name of a file in the staged dir that indicates the staged operation is an "uninstall".
-// See also libcore.tzdata.update2.TimeZoneDistroInstaller.
-static const char* UNINSTALL_TOMBSTONE_FILE_NAME = "/STAGED_UNINSTALL_TOMBSTONE";
-
-// The name of the file containing the distro version information.
-// See also com.android.timezone.distro.TimeZoneDistro / com.android.timezone.distro.DistroVersion.
-static const char* DISTRO_VERSION_FILENAME = "/distro_version";
-
-// distro_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 distro 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 distro corrections (e.g. 001)
-// We only need the first 13 to determine if it is suitable for the device.
-static const int DISTRO_VERSION_LENGTH = 13;
-
-// The major version of the distro format supported by this code as a null-terminated char[].
-// See also com.android.timezone.distro.TimeZoneDistro / com.android.timezone.distro.DistroVersion.
-static const char SUPPORTED_DISTRO_MAJOR_VERSION[] = "001";
-
-// The length of the distro format major version excluding the \0
-static const size_t SUPPORTED_DISTRO_MAJOR_VERSION_LEN = sizeof(SUPPORTED_DISTRO_MAJOR_VERSION) - 1;
-
-// The minor version of the distro format supported by this code as a null-terminated char[].
-// See also com.android.timezone.distro.TimeZoneDistro / com.android.timezone.distro.DistroVersion.
-static const char SUPPORTED_DISTRO_MINOR_VERSION[] = "001";
-
-// The length of the distro format minor version excluding the \0
-static const size_t SUPPORTED_DISTRO_MINOR_VERSION_LEN = sizeof(SUPPORTED_DISTRO_MINOR_VERSION) - 1;
-
-// The length of the distro format version. e.g. 001.001
-static const size_t SUPPORTED_DISTRO_VERSION_LEN =
-        SUPPORTED_DISTRO_MAJOR_VERSION_LEN + SUPPORTED_DISTRO_MINOR_VERSION_LEN + 1;
-
-// The length of the IANA rules version bytes. e.g. 2016a
-static const size_t RULES_VERSION_LEN = 5;
-
-// Distro version bytes are: AAA.BBB|CCCCC - the rules version is CCCCC
-static const size_t DISTRO_VERSION_RULES_IDX = 8;
-
-// See also com.android.timezone.distro.TimeZoneDistro.
-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 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"
-            "Checks whether any timezone update distro 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 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 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(buffer, 1, byteCount, file);
-    fclose(file);
-    if (bytesRead != byteCount) {
-        LOG(WARNING) << fileName << " is too small. " << byteCount << " bytes required";
-        return false;
-    }
-    return true;
-}
-
-/*
- * 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(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 checkValidDistroVersion(const char* buffer) {
-    // See DISTRO_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. */
-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;
-}
-
-enum PathStatus { ERR, NONE, IS_DIR, IS_REG, UNKNOWN };
-
-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 : S_ISREG(buf.st_mode) ? IS_REG : UNKNOWN;
-}
-
-/*
- * Deletes fileToDelete and returns true if it is successful. If fileToDelete is not a file or
- * cannot be accessed this method returns false.
- */
-static bool deleteFile(const std::string& fileToDelete) {
-    // Check whether the file exists.
-    PathStatus pathStatus = checkPath(fileToDelete);
-    if (pathStatus == NONE) {
-        LOG(INFO) << "Path " << fileToDelete << " does not exist";
-        return true;
-    }
-    if (pathStatus != IS_REG) {
-        LOG(WARNING) << "Path " << fileToDelete << " failed to stat() or is not a file.";
-        return false;
-    }
-
-    // Attempt the deletion.
-    int rc = unlink(fileToDelete.c_str());
-    if (rc != 0) {
-        PLOG(WARNING) << "unlink() failed for " << fileToDelete;
-    }
-    return rc == 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. 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
- * 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.
-    int pathStatus = checkPath(dirToDelete);
-    if (pathStatus == NONE) {
-        LOG(INFO) << "Path " << dirToDelete << " does not exist";
-        return true;
-    }
-    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";
-
-    // 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 (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 "
-                << &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;
-}
-
-/*
- * 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;
-    if (!deleteDir(dataUpdatesDirName)) {
-        LOG(WARNING) << "Deletion of install metadata " << dataUpdatesDirName
-                << " was not successful";
-    }
-}
-
-/*
- * Deletes the timezone update distro directory.
- */
-static void deleteUpdateDistroDir(const std::string& distroDirName) {
-    LOG(INFO) << "Removing: " << distroDirName;
-    if (!deleteDir(distroDirName)) {
-        LOG(WARNING) << "Deletion of distro dir " << distroDirName << " was not successful";
-    }
-}
-
-static void handleStagedUninstall(const std::string& dataStagedDirName,
-                                  const std::string& dataCurrentDirName,
-                                  const PathStatus dataCurrentDirStatus) {
-    LOG(INFO) << "Staged operation is an uninstall.";
-
-    // Delete the current install directory.
-    switch (dataCurrentDirStatus) {
-        case NONE:
-            // This is unexpected: No uninstall should be staged if there is nothing to
-            // uninstall. Carry on anyway.
-            LOG(WARNING) << "No current install to delete.";
-            break;
-        case IS_DIR:
-            // This is normal. Delete the current install dir.
-            if (!deleteDir(dataCurrentDirName)) {
-                LOG(WARNING) << "Deletion of current distro " << dataCurrentDirName
-                             << " was not successful";
-                // If this happens we don't know whether we were able to delete or not. We don't
-                // delete the staged operation so it will be retried next boot unless overridden.
-                return;
-            }
-            break;
-        case IS_REG:
-        default:
-            // This is unexpected: We can try to delete the unexpected file and carry on.
-            LOG(WARNING) << "Current distro dir " << dataCurrentDirName
-                         << " is not actually a directory. Attempting deletion.";
-            if (!deleteFile(dataCurrentDirName)) {
-                LOG(WARNING) << "Could not delete " << dataCurrentDirName;
-                return;
-            }
-            break;
-    }
-
-    // Delete the staged uninstall dir.
-    if (!deleteDir(dataStagedDirName)) {
-        LOG(WARNING) << "Deletion of current distro " << dataCurrentDirName
-                     << " was not successful";
-        // If this happens we don't know whether we were able to delete the staged operation
-        // or not.
-        return;
-    }
-    LOG(INFO) << "Staged uninstall complete.";
-}
-
-static void handleStagedInstall(const std::string& dataStagedDirName,
-                                const std::string& dataCurrentDirName,
-                                const PathStatus dataCurrentDirStatus) {
-    LOG(INFO) << "Staged operation is an install.";
-
-    switch (dataCurrentDirStatus) {
-        case NONE:
-            // This is expected: This is the first install.
-            LOG(INFO) << "No current install to replace.";
-            break;
-        case IS_DIR:
-            // This is expected: We are replacing an existing install.
-            // Delete the current dir so we can replace it.
-            if (!deleteDir(dataCurrentDirName)) {
-                LOG(WARNING) << "Deletion of current distro " << dataCurrentDirName
-                             << " was not successful";
-                // If this happens, we cannot proceed.
-                return;
-            }
-            break;
-        case IS_REG:
-        default:
-            // This is unexpected: We can try to delete the unexpected file and carry on.
-            LOG(WARNING) << "Current distro dir " << dataCurrentDirName
-                         << " is not actually a directory. Attempting deletion.";
-            if (!deleteFile(dataCurrentDirName)) {
-                LOG(WARNING) << "Could not delete " << dataCurrentDirName;
-                return;
-            }
-            break;
-    }
-
-    // Move the staged dir so it is the new current dir, completing the install.
-    LOG(INFO) << "Moving " << dataStagedDirName << " to " << dataCurrentDirName;
-    int rc = rename(dataStagedDirName.c_str(), dataCurrentDirName.c_str());
-    if (rc == -1) {
-        PLOG(WARNING) << "Unable to rename directory from " << dataStagedDirName << " to "
-                      << &dataCurrentDirName[0];
-        return;
-    }
-
-    LOG(INFO) << "Staged install complete.";
-}
-/*
- * Process a staged operation if there is one.
- */
-static void processStagedOperation(const std::string& dataStagedDirName,
-                                   const std::string& dataCurrentDirName) {
-    PathStatus dataStagedDirStatus = checkPath(dataStagedDirName);
-
-    // Exit early for the common case.
-    if (dataStagedDirStatus == NONE) {
-        LOG(DEBUG) << "No staged time zone operation.";
-        return;
-    }
-
-    // Check known directory names are in a good starting state.
-    if (dataStagedDirStatus != IS_DIR) {
-        LOG(WARNING) << "Staged distro dir " << dataStagedDirName
-                     << " could not be accessed or is not a directory."
-                     << " stagedDirStatus=" << dataStagedDirStatus;
-        return;
-    }
-
-    // dataStagedDirStatus == IS_DIR.
-
-    // Work out whether there is anything currently installed.
-    PathStatus dataCurrentDirStatus = checkPath(dataCurrentDirName);
-    if (dataCurrentDirStatus == ERR) {
-        LOG(WARNING) << "Current install dir " << dataCurrentDirName << " could not be accessed"
-                     << " dataCurrentDirStatus=" << dataCurrentDirStatus;
-        return;
-    }
-
-    // We must perform the staged operation.
-
-    // Check to see if the staged directory contains an uninstall or an install operation.
-    std::string uninstallTombStoneFile(dataStagedDirName);
-    uninstallTombStoneFile += UNINSTALL_TOMBSTONE_FILE_NAME;
-    int uninstallTombStoneFileStatus = checkPath(uninstallTombStoneFile);
-    if (uninstallTombStoneFileStatus != IS_REG && uninstallTombStoneFileStatus != NONE) {
-        // Error case.
-        LOG(WARNING) << "Unable to determine if the staged operation is an uninstall.";
-        return;
-    }
-    if (uninstallTombStoneFileStatus == IS_REG) {
-        handleStagedUninstall(dataStagedDirName, dataCurrentDirName, dataCurrentDirStatus);
-    } else {
-        // uninstallTombStoneFileStatus == NONE meaning this is a staged install.
-        handleStagedInstall(dataStagedDirName, dataCurrentDirName, dataCurrentDirStatus);
-    }
-}
-
-/*
- * 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.
- *
- * 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();
-        return 1;
-    }
-
-    const char* systemZoneInfoDir = argv[1];
-    const char* dataZoneInfoDir = argv[2];
-
-    std::string dataStagedDirName(dataZoneInfoDir);
-    dataStagedDirName += STAGED_DIR_NAME;
-
-    std::string dataCurrentDirName(dataZoneInfoDir);
-    dataCurrentDirName += CURRENT_DIR_NAME;
-
-    // Check for an process any staged operation.
-    // If the staged operation could not be handled we still have to validate the current installed
-    // directory so we do not check for errors and do not quit early.
-    processStagedOperation(dataStagedDirName, dataCurrentDirName);
-
-    // Check the distro directory exists. If it does not, exit quickly: nothing to do.
-    PathStatus dataCurrentDirStatus = checkPath(dataCurrentDirName);
-    if (dataCurrentDirStatus == NONE) {
-        LOG(INFO) << "timezone distro dir " << dataCurrentDirName
-                << " does not exist. No action required.";
-        return 0;
-    }
-
-    // If the distro 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 distro dir " << dataCurrentDirName
-                << " could not be accessed or is not a directory. result=" << dataCurrentDirStatus;
-        return 2;
-    }
-
-    // Check the installed distro version.
-    std::string distroVersionFileName(dataCurrentDirName);
-    distroVersionFileName += DISTRO_VERSION_FILENAME;
-    std::vector<char> distroVersion;
-    distroVersion.reserve(DISTRO_VERSION_LENGTH);
-    bool distroVersionReadOk =
-            readBytes(distroVersionFileName, distroVersion.data(), DISTRO_VERSION_LENGTH);
-    if (!distroVersionReadOk) {
-        LOG(WARNING) << "distro version file " << distroVersionFileName
-                << " does not exist or is too short. Deleting distro dir.";
-        // Implies the contents of the data partition is corrupt in some way. Try to clean up.
-        deleteConfigUpdaterMetadataDir(dataZoneInfoDir);
-        deleteUpdateDistroDir(dataCurrentDirName);
-        return 3;
-    }
-
-    if (!checkValidDistroVersion(distroVersion.data())) {
-        LOG(WARNING) << "distro version file " << distroVersionFileName
-                << " is not valid. Deleting distro dir.";
-        // Implies the contents of the data partition is corrupt in some way. Try to clean up.
-        deleteConfigUpdaterMetadataDir(dataZoneInfoDir);
-        deleteUpdateDistroDir(dataCurrentDirName);
-        return 4;
-    }
-
-    std::string actualDistroVersion =
-            std::string(distroVersion.data(), SUPPORTED_DISTRO_VERSION_LEN);
-    // Check the first 3 bytes of the distro version: these are the major version (e.g. 001).
-    // It must match the one we support exactly to be ok.
-    if (strncmp(
-            &distroVersion[0],
-            SUPPORTED_DISTRO_MAJOR_VERSION,
-            SUPPORTED_DISTRO_MAJOR_VERSION_LEN) != 0) {
-
-        LOG(INFO) << "distro version file " << distroVersionFileName
-                << " major version is not the required version " << SUPPORTED_DISTRO_MAJOR_VERSION
-                << ", was \"" << actualDistroVersion << "\". Deleting distro dir.";
-        // This implies there has been an OTA and the installed distro is not compatible with the
-        // new version of Android. Remove the installed distro.
-        deleteConfigUpdaterMetadataDir(dataZoneInfoDir);
-        deleteUpdateDistroDir(dataCurrentDirName);
-        return 5;
-    }
-
-    // Check the last 3 bytes of the distro version: these are the minor version (e.g. 001).
-    // If the version in the distro is < the minor version required by this device it cannot be
-    // used.
-    if (strncmp(
-            &distroVersion[4],
-            SUPPORTED_DISTRO_MINOR_VERSION,
-            SUPPORTED_DISTRO_MINOR_VERSION_LEN) < 0) {
-
-        LOG(INFO) << "distro version file " << distroVersionFileName
-                << " minor version is not the required version " << SUPPORTED_DISTRO_MINOR_VERSION
-                << ", was \"" << actualDistroVersion << "\". Deleting distro dir.";
-        // This implies there has been an OTA and the installed distro is not compatible with the
-        // new version of Android. Remove the installed distro.
-        deleteConfigUpdaterMetadataDir(dataZoneInfoDir);
-        deleteUpdateDistroDir(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 =
-            readBytes(systemTzDataFileName, systemTzDataHeader.data(), TZ_HEADER_LENGTH);
-    if (!systemFileExists) {
-        // 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;
-    }
-    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;
-    }
-
-    // Compare the distro rules version against the system rules version.
-    if (strncmp(
-            &systemTzDataHeader[TZ_DATA_HEADER_PREFIX_LEN],
-            &distroVersion[DISTRO_VERSION_RULES_IDX],
-            RULES_VERSION_LEN) <= 0) {
-        LOG(INFO) << "Found an installed distro 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 distro.
-    LOG(INFO) << "timezone distro in " << dataCurrentDirName << " is older than data in "
-            << systemTzDataFileName << "; fixing...";
-
-    deleteConfigUpdaterMetadataDir(dataZoneInfoDir);
-    deleteUpdateDistroDir(dataCurrentDirName);
-    return 0;
-}