Merge "Remove time compensation for bad NITZ offset info" (e90eaa72) · Commits · e / os / android_frameworks_opt_telephony

src/java/com/android/internal/telephony/NitzStateMachine.java

+42 −75

Original line number	Diff line number	Diff line
		@@ -25,7 +25,6 @@ import android.telephony.Rlog;
		import android.telephony.TelephonyManager;
		import android.text.TextUtils;
		import android.util.LocalLog;
		import android.util.TimeUtils;

		import com.android.internal.annotations.VisibleForTesting;
		import com.android.internal.telephony.TimeZoneLookupHelper.CountryResult;
		@@ -36,7 +35,6 @@ import com.android.internal.util.IndentingPrintWriter;

		import java.io.FileDescriptor;
		import java.io.PrintWriter;
		import java.util.TimeZone;

		/**
		* {@hide}
		@@ -241,67 +239,17 @@ public class NitzStateMachine {
		+ " not setting zone");
		}
		} else { // mLatestNitzSignal != null
		if (nitzOffsetMightBeBogus(mLatestNitzSignal.mValue)
		&& isTimeZoneSettingInitialized
		&& !countryUsesUtc(isoCountryCode, mLatestNitzSignal)) {

		// This case means that (1) the device received an NITZ signal that could be
		// bogus due to having a zero offset from UTC, (2) the device has had a time
		// zone set explicitly and (3) the iso tells us the country is NOT one that uses
		// a zero offset. This is interpreted as being NITZ incorrectly reporting a
		// local time and not a UTC time. The zone is left as the current device's zone
		// setting, and the system clock may be adjusted by taking the NITZ time and
		// assuming the current zone setting is correct.

		TimeZone zone = TimeZone.getDefault();
		if (isNitzSignalOffsetInfoBogus(mLatestNitzSignal, isoCountryCode)) {
		String logMsg = "handleNetworkCountryCodeSet: Stored NITZ looks bogus, "
		+ " isoCountryCode=" + isoCountryCode
		+ " mLatestNitzSignal=" + mLatestNitzSignal;
		if (DBG) {
		Rlog.d(LOG_TAG, "handleNetworkCountryCodeSet: NITZ looks bogus, maybe using"
		+ " current default zone to adjust the system clock,"
		+ " mNeedCountryCodeForNitz=" + mNeedCountryCodeForNitz
		+ " mLatestNitzSignal=" + mLatestNitzSignal
		+ " zone=" + zone);
		Rlog.d(LOG_TAG, logMsg);
		}
		zoneId = zone.getID();

		if (mNeedCountryCodeForNitz) {
		NitzData nitzData = mLatestNitzSignal.mValue;
		try {
		// Acquire the wakelock as we're reading the elapsed realtime clock
		// here.
		mWakeLock.acquire();
		mTimeZoneLog.log(logMsg);

		// Use the time that came with the NITZ offset that we think is bogus:
		// we just interpret it as local time.
		long ctm = nitzData.getCurrentTimeInMillis();
		long delayAdjustedCtm = ctm + (mTimeServiceHelper.elapsedRealtime()
		- mLatestNitzSignal.mElapsedRealtime);
		long tzOffset = zone.getOffset(delayAdjustedCtm);
		if (DBG) {
		Rlog.d(LOG_TAG, "handleNetworkCountryCodeSet:"
		+ " tzOffset=" + tzOffset
		+ " delayAdjustedCtm="
		+ TimeUtils.logTimeOfDay(delayAdjustedCtm));
		}
		if (mTimeServiceHelper.isTimeDetectionEnabled()) {
		long timeZoneAdjustedCtm = delayAdjustedCtm - tzOffset;
		String msg = "handleNetworkCountryCodeSet: setting time"
		+ " timeZoneAdjustedCtm="
		+ TimeUtils.logTimeOfDay(timeZoneAdjustedCtm);
		setAndBroadcastNetworkSetTime(msg, timeZoneAdjustedCtm);
		} else {
		// Adjust the saved NITZ time to account for tzOffset.
		mSavedNitzTime = new TimeStampedValue<>(
		mSavedNitzTime.mValue - tzOffset,
		mSavedNitzTime.mElapsedRealtime);
		if (DBG) {
		Rlog.d(LOG_TAG, "handleNetworkCountryCodeSet:"
		+ "adjusting time mSavedNitzTime=" + mSavedNitzTime);
		}
		}
		} finally {
		mWakeLock.release();
		}
		}
		// No zone can be determined.
		zoneId = null;
		} else {
		NitzData nitzData = mLatestNitzSignal.mValue;
		OffsetResult lookupResult =
		@@ -372,14 +320,6 @@ public class NitzStateMachine {
		mNitzTimeZoneDetectionSuccessful = false;
		}

		/**
		* Returns {@code true} if the NITZ data looks like it might be incomplete or bogus, i.e. it has
		* a zero offset from UTC with either no DST information available or a zero DST offset.
		*/
		private static boolean nitzOffsetMightBeBogus(NitzData nitzData) {
		return nitzData.getLocalOffsetMillis() == 0 && !nitzData.isDst();
		}

		/**
		* Handle a new NITZ signal being received.
		*/
		@@ -391,6 +331,22 @@ public class NitzStateMachine {
		handleTimeFromNitz(nitzSignal);
		}

		/**
		* Returns true if the NITZ signal is definitely bogus, assuming that the country is correct.
		*/
		private boolean isNitzSignalOffsetInfoBogus(
		TimeStampedValue<NitzData> nitzSignal, String isoCountryCode) {

		if (TextUtils.isEmpty(isoCountryCode)) {
		// We cannot say for sure.
		return false;
		}

		NitzData newNitzData = nitzSignal.mValue;
		boolean zeroOffsetNitz = newNitzData.getLocalOffsetMillis() == 0 && !newNitzData.isDst();
		return zeroOffsetNitz && !countryUsesUtc(isoCountryCode, nitzSignal);
		}

		private void handleTimeZoneFromNitz(TimeStampedValue<NitzData> nitzSignal) {
		try {
		NitzData newNitzData = nitzSignal.mValue;
		@@ -406,12 +362,7 @@ public class NitzStateMachine {
		// We don't have a country code so we won't try to look up the time zone.
		zoneId = null;
		needCountryCode = true;
		} else if (!TextUtils.isEmpty(isoCountryCode)) {
		OffsetResult lookupResult = mTimeZoneLookupHelper.lookupByNitzCountry(
		newNitzData, isoCountryCode);
		zoneId = lookupResult != null ? lookupResult.zoneId : null;
		needCountryCode = false;
		} else {
		} else if (TextUtils.isEmpty(isoCountryCode)) {
		// We have a country code but it's empty. This is most likely because we're on a
		// test network that's using a bogus MCC (eg, "001"), so get a TimeZone
		// based only on the NITZ parameters.
		@@ -422,6 +373,22 @@ public class NitzStateMachine {
		}
		zoneId = lookupResult != null ? lookupResult.zoneId : null;
		needCountryCode = false;
		} else if (isNitzSignalOffsetInfoBogus(nitzSignal, isoCountryCode)) {
		String logMsg = "handleNitzReceived: Received NITZ looks bogus, "
		+ " isoCountryCode=" + isoCountryCode
		+ " nitzSignal=" + nitzSignal;
		if (DBG) {
		Rlog.d(LOG_TAG, logMsg);
		}
		mTimeZoneLog.log(logMsg);

		zoneId = null;
		needCountryCode = false;
		} else {
		OffsetResult lookupResult = mTimeZoneLookupHelper.lookupByNitzCountry(
		newNitzData, isoCountryCode);
		zoneId = lookupResult != null ? lookupResult.zoneId : null;
		needCountryCode = false;
		}
		}

tests/telephonytests/src/com/android/internal/telephony/NitzStateMachineTest.java

+274 −22

Original line number	Diff line number	Diff line
		@@ -45,6 +45,37 @@ import org.mockito.Mock;

		public class NitzStateMachineTest extends TelephonyTest {

		// A country with a single zone : the zone can be guessed from the country.
		// The UK uses UTC for part of the year so it is not good for detecting bogus NITZ signals.
		private static final Scenario UNITED_KINGDOM_SCENARIO = new Scenario.Builder()
		.setInitialDeviceSystemClockUtc(1977, 1, 1, 12, 0, 0)
		.setInitialDeviceRealtimeMillis(123456789L)
		.setTimeZone("Europe/London")
		.setActualTimeUtc(2018, 1, 1, 12, 0, 0)
		.setCountryIso("gb")
		.build();

		// A country that has multiple zones, but there is only one matching time zone at the time :
		// the zone cannot be guessed from the country alone, but can be guessed from the country +
		// NITZ. The US never uses UTC so it can be used for testing bogus NITZ signal handling.
		private static final Scenario UNIQUE_US_ZONE_SCENARIO = new Scenario.Builder()
		.setInitialDeviceSystemClockUtc(1977, 1, 1, 12, 0, 0)
		.setInitialDeviceRealtimeMillis(123456789L)
		.setTimeZone("America/Los_Angeles")
		.setActualTimeUtc(2018, 1, 1, 12, 0, 0)
		.setCountryIso("us")
		.build();

		// A country with a single zone: the zone can be guessed from the country alone. CZ never uses
		// UTC so it can be used for testing bogus NITZ signal handling.
		private static final Scenario CZECHIA_SCENARIO = new Scenario.Builder()
		.setInitialDeviceSystemClockUtc(1977, 1, 1, 12, 0, 0)
		.setInitialDeviceRealtimeMillis(123456789L)
		.setTimeZone("Europe/Prague")
		.setActualTimeUtc(2018, 1, 1, 12, 0, 0)
		.setCountryIso("cz")
		.build();

		@Mock
		private NitzStateMachine.DeviceState mDeviceState;

		@@ -75,17 +106,6 @@ public class NitzStateMachineTest extends TelephonyTest {
		super.tearDown();
		}

		// A country that has multiple zones, but there is only one matching time zone at the time :
		// the zone cannot be guessed from the country alone, but can be guessed from the country +
		// NITZ.
		private static final Scenario UNIQUE_US_ZONE_SCENARIO = new Scenario.Builder()
		.setInitialDeviceSystemClockUtc(1977, 1, 1, 12, 0, 0)
		.setInitialDeviceRealtimeMillis(123456789L)
		.setTimeZone("America/Los_Angeles")
		.setActualTimeUtc(2018, 1, 1, 12, 0, 0)
		.setCountryIso("us")
		.build();

		@Test
		public void test_uniqueUsZone_Assumptions() {
		// Check we'll get the expected behavior from TimeZoneLookupHelper.
		@@ -109,15 +129,6 @@ public class NitzStateMachineTest extends TelephonyTest {
		assertEquals(expectedLookupResult, actualLookupResult);
		}

		// A country with a single zone : the zone can be guessed from the country.
		private static final Scenario UNITED_KINGDOM_SCENARIO = new Scenario.Builder()
		.setInitialDeviceSystemClockUtc(1977, 1, 1, 12, 0, 0)
		.setInitialDeviceRealtimeMillis(123456789L)
		.setTimeZone("Europe/London")
		.setActualTimeUtc(2018, 1, 1, 12, 0, 0)
		.setCountryIso("gb")
		.build();

		@Test
		public void test_unitedKingdom_Assumptions() {
		// Check we'll get the expected behavior from TimeZoneLookupHelper.
		@@ -416,6 +427,246 @@ public class NitzStateMachineTest extends TelephonyTest {
		assertEquals(scenario.getTimeZoneId(), mNitzStateMachine.getSavedTimeZoneId());
		}

		@Test
		public void test_validCzNitzSignal_nitzReceivedFirst() throws Exception {
		Scenario scenario = CZECHIA_SCENARIO;
		Device device = new DeviceBuilder()
		.setClocksFromScenario(scenario)
		.setTimeDetectionEnabled(true)
		.setTimeZoneDetectionEnabled(true)
		.setTimeZoneSettingInitialized(true)
		.initialize();
		Script script = new Script(device);

		TimeStampedValue<NitzData> goodNitzSignal = scenario.getNitzSignal();

		// Simulate receiving an NITZ signal.
		script.nitzReceived(goodNitzSignal)
		// The NITZ alone isn't enough to detect a time zone.
		.verifyOnlyTimeWasSetAndReset(scenario.getActualTimeMillis());

		// Check NitzStateMachine state.
		assertFalse(mNitzStateMachine.getNitzTimeZoneDetectionSuccessful());
		assertEquals(goodNitzSignal.mValue, mNitzStateMachine.getCachedNitzData());
		assertNull(mNitzStateMachine.getSavedTimeZoneId());

		// Simulate the country code becoming known.
		script.countryReceived(scenario.getNetworkCountryIsoCode())
		// The NITZ country is enough to detect the time zone, but the NITZ + country is
		// also sufficient so we expect the time zone to be set twice.
		.verifyOnlyTimeZoneWasSetAndReset(scenario.getTimeZoneId(), 2);

		// Check NitzStateMachine state.
		assertTrue(mNitzStateMachine.getNitzTimeZoneDetectionSuccessful());
		assertEquals(goodNitzSignal.mValue, mNitzStateMachine.getCachedNitzData());
		assertEquals(scenario.getTimeZoneId(), mNitzStateMachine.getSavedTimeZoneId());
		}

		@Test
		public void test_validCzNitzSignal_countryReceivedFirst() throws Exception {
		Scenario scenario = CZECHIA_SCENARIO;
		Device device = new DeviceBuilder()
		.setClocksFromScenario(scenario)
		.setTimeDetectionEnabled(true)
		.setTimeZoneDetectionEnabled(true)
		.setTimeZoneSettingInitialized(true)
		.initialize();
		Script script = new Script(device);

		TimeStampedValue<NitzData> goodNitzSignal = scenario.getNitzSignal();

		// Simulate the country code becoming known.
		script.countryReceived(scenario.getNetworkCountryIsoCode())
		// The NITZ country is enough to detect the time zone.
		.verifyOnlyTimeZoneWasSetAndReset(scenario.getTimeZoneId(), 1);

		// Check NitzStateMachine state.
		assertFalse(mNitzStateMachine.getNitzTimeZoneDetectionSuccessful());
		assertNull(mNitzStateMachine.getCachedNitzData());
		assertEquals(scenario.getTimeZoneId(), mNitzStateMachine.getSavedTimeZoneId());

		// Simulate receiving an NITZ signal.
		script.nitzReceived(goodNitzSignal)
		// The time will be set from the NITZ signal.
		// The combination of NITZ + country will cause the time zone to be set.
		.verifyTimeAndZoneSetAndReset(
		scenario.getActualTimeMillis(), scenario.getTimeZoneId());

		// Check NitzStateMachine state.
		assertTrue(mNitzStateMachine.getNitzTimeZoneDetectionSuccessful());
		assertEquals(goodNitzSignal.mValue, mNitzStateMachine.getCachedNitzData());
		assertEquals(scenario.getTimeZoneId(), mNitzStateMachine.getSavedTimeZoneId());
		}

		@Test
		public void test_bogusCzNitzSignal_nitzReceivedFirst() throws Exception {
		Scenario scenario = CZECHIA_SCENARIO;
		Device device = new DeviceBuilder()
		.setClocksFromScenario(scenario)
		.setTimeDetectionEnabled(true)
		.setTimeZoneDetectionEnabled(true)
		.setTimeZoneSettingInitialized(true)
		.initialize();
		Script script = new Script(device);

		TimeStampedValue<NitzData> goodNitzSignal = scenario.getNitzSignal();

		// Create a corrupted NITZ signal, where the offset information has been lost.
		NitzData bogusNitzData = NitzData.createForTests(
		0 /* UTC! /, null / dstOffsetMillis */,
		goodNitzSignal.mValue.getCurrentTimeInMillis(), null /* emulatorHostTimeZone */);
		TimeStampedValue<NitzData> badNitzSignal = new TimeStampedValue<>(
		bogusNitzData, goodNitzSignal.mElapsedRealtime);

		// Simulate receiving an NITZ signal.
		script.nitzReceived(badNitzSignal)
		// The NITZ alone isn't enough to detect a time zone, but there isn't enough
		// information to work out its bogus.
		.verifyOnlyTimeWasSetAndReset(scenario.getActualTimeMillis());

		// Check NitzStateMachine state.
		assertFalse(mNitzStateMachine.getNitzTimeZoneDetectionSuccessful());
		assertEquals(badNitzSignal.mValue, mNitzStateMachine.getCachedNitzData());
		assertNull(mNitzStateMachine.getSavedTimeZoneId());

		// Simulate the country code becoming known.
		script.countryReceived(scenario.getNetworkCountryIsoCode())
		// The country is enough to detect the time zone for CZ. If the NITZ signal
		// wasn't obviously bogus we'd try to set it twice.
		.verifyOnlyTimeZoneWasSetAndReset(scenario.getTimeZoneId(), 1);

		// Check NitzStateMachine state.
		assertFalse(mNitzStateMachine.getNitzTimeZoneDetectionSuccessful());
		assertEquals(badNitzSignal.mValue, mNitzStateMachine.getCachedNitzData());
		assertEquals(scenario.getTimeZoneId(), mNitzStateMachine.getSavedTimeZoneId());
		}

		@Test
		public void test_bogusCzNitzSignal_countryReceivedFirst() throws Exception {
		Scenario scenario = CZECHIA_SCENARIO;
		Device device = new DeviceBuilder()
		.setClocksFromScenario(scenario)
		.setTimeDetectionEnabled(true)
		.setTimeZoneDetectionEnabled(true)
		.setTimeZoneSettingInitialized(true)
		.initialize();
		Script script = new Script(device);

		TimeStampedValue<NitzData> goodNitzSignal = scenario.getNitzSignal();

		// Create a corrupted NITZ signal, where the offset information has been lost.
		NitzData bogusNitzData = NitzData.createForTests(
		0 /* UTC! /, null / dstOffsetMillis */,
		goodNitzSignal.mValue.getCurrentTimeInMillis(), null /* emulatorHostTimeZone */);
		TimeStampedValue<NitzData> badNitzSignal = new TimeStampedValue<>(
		bogusNitzData, goodNitzSignal.mElapsedRealtime);

		// Simulate the country code becoming known.
		script.countryReceived(scenario.getNetworkCountryIsoCode())
		// The country is enough to detect the time zone for CZ.
		.verifyOnlyTimeZoneWasSetAndReset(scenario.getTimeZoneId());

		// Check NitzStateMachine state.
		assertFalse(mNitzStateMachine.getNitzTimeZoneDetectionSuccessful());
		assertNull(mNitzStateMachine.getCachedNitzData());
		assertEquals(scenario.getTimeZoneId(), mNitzStateMachine.getSavedTimeZoneId());

		// Simulate receiving an NITZ signal.
		script.nitzReceived(badNitzSignal)
		// The NITZ should be detected as bogus so only the time will be set.
		.verifyOnlyTimeWasSetAndReset(scenario.getActualTimeMillis());

		// Check NitzStateMachine state.
		assertFalse(mNitzStateMachine.getNitzTimeZoneDetectionSuccessful());
		assertEquals(badNitzSignal.mValue, mNitzStateMachine.getCachedNitzData());
		assertEquals(scenario.getTimeZoneId(), mNitzStateMachine.getSavedTimeZoneId());
		}

		@Test
		public void test_bogusUniqueUsNitzSignal_nitzReceivedFirst() throws Exception {
		Scenario scenario = UNIQUE_US_ZONE_SCENARIO;
		Device device = new DeviceBuilder()
		.setClocksFromScenario(scenario)
		.setTimeDetectionEnabled(true)
		.setTimeZoneDetectionEnabled(true)
		.setTimeZoneSettingInitialized(true)
		.initialize();
		Script script = new Script(device);

		TimeStampedValue<NitzData> goodNitzSignal = scenario.getNitzSignal();

		// Create a corrupted NITZ signal, where the offset information has been lost.
		NitzData bogusNitzData = NitzData.createForTests(
		0 /* UTC! /, null / dstOffsetMillis */,
		goodNitzSignal.mValue.getCurrentTimeInMillis(), null /* emulatorHostTimeZone */);
		TimeStampedValue<NitzData> badNitzSignal = new TimeStampedValue<>(
		bogusNitzData, goodNitzSignal.mElapsedRealtime);

		// Simulate receiving an NITZ signal.
		script.nitzReceived(badNitzSignal)
		// The NITZ alone isn't enough to detect a time zone, but there isn't enough
		// information to work out its bogus.
		.verifyOnlyTimeWasSetAndReset(scenario.getActualTimeMillis());

		// Check NitzStateMachine state.
		assertFalse(mNitzStateMachine.getNitzTimeZoneDetectionSuccessful());
		assertEquals(badNitzSignal.mValue, mNitzStateMachine.getCachedNitzData());
		assertNull(mNitzStateMachine.getSavedTimeZoneId());

		// Simulate the country code becoming known.
		script.countryReceived(scenario.getNetworkCountryIsoCode())
		// The country isn't enough to detect the time zone for US so we will leave the time
		// zone unset.
		.verifyNothingWasSetAndReset();

		// Check NitzStateMachine state.
		assertFalse(mNitzStateMachine.getNitzTimeZoneDetectionSuccessful());
		assertEquals(badNitzSignal.mValue, mNitzStateMachine.getCachedNitzData());
		assertNull(mNitzStateMachine.getSavedTimeZoneId());
		}

		@Test
		public void test_bogusUsUniqueNitzSignal_countryReceivedFirst() throws Exception {
		Scenario scenario = UNIQUE_US_ZONE_SCENARIO;
		Device device = new DeviceBuilder()
		.setClocksFromScenario(scenario)
		.setTimeDetectionEnabled(true)
		.setTimeZoneDetectionEnabled(true)
		.setTimeZoneSettingInitialized(true)
		.initialize();
		Script script = new Script(device);

		TimeStampedValue<NitzData> goodNitzSignal = scenario.getNitzSignal();

		// Create a corrupted NITZ signal, where the offset information has been lost.
		NitzData bogusNitzData = NitzData.createForTests(
		0 /* UTC! /, null / dstOffsetMillis */,
		goodNitzSignal.mValue.getCurrentTimeInMillis(), null /* emulatorHostTimeZone */);
		TimeStampedValue<NitzData> badNitzSignal = new TimeStampedValue<>(
		bogusNitzData, goodNitzSignal.mElapsedRealtime);

		// Simulate the country code becoming known.
		script.countryReceived(scenario.getNetworkCountryIsoCode())
		// The country isn't enough to detect the time zone for US so we will leave the time
		// zone unset.
		.verifyNothingWasSetAndReset();

		// Check NitzStateMachine state.
		assertFalse(mNitzStateMachine.getNitzTimeZoneDetectionSuccessful());
		assertNull(mNitzStateMachine.getCachedNitzData());
		assertNull(mNitzStateMachine.getSavedTimeZoneId());

		// Simulate receiving an NITZ signal.
		script.nitzReceived(badNitzSignal)
		// The NITZ should be detected as bogus so only the time will be set.
		.verifyOnlyTimeWasSetAndReset(scenario.getActualTimeMillis());

		// Check NitzStateMachine state.
		assertFalse(mNitzStateMachine.getNitzTimeZoneDetectionSuccessful());
		assertEquals(badNitzSignal.mValue, mNitzStateMachine.getCachedNitzData());
		assertNull(mNitzStateMachine.getSavedTimeZoneId());
		}

		private static long createUtcTime(int year, int monthInYear, int day, int hourOfDay, int minute,
		int second) {
		Calendar cal = new GregorianCalendar(TimeZone.getTimeZone("Etc/UTC"));
		@@ -647,8 +898,9 @@ public class NitzStateMachineTest extends TelephonyTest {
		int[] offsets = new int[2];
		mZone.getOffset(mActualTimeMillis, false /* local */, offsets);
		int zoneOffsetMillis = offsets[0] + offsets[1];
		NitzData nitzData = NitzData
		.createForTests(zoneOffsetMillis, offsets[1], mActualTimeMillis, null);
		NitzData nitzData = NitzData.createForTests(
		zoneOffsetMillis, offsets[1], mActualTimeMillis,
		null /* emulatorHostTimeZone */);
		mNitzSignal = new TimeStampedValue<>(nitzData, mInitialDeviceRealtimeMillis);
		}
		return mNitzSignal;