Merge "Ignore NTP time fixes that differ from system time by more than 5 minutes." into eclair (a0460004) · Commits · e / os / android_frameworks_base

location/java/com/android/internal/location/GpsLocationProvider.java

+26 −8

Original line number	Diff line number	Diff line
		@@ -57,6 +57,7 @@ import java.io.StringBufferInputStream;
		import java.net.InetAddress;
		import java.net.UnknownHostException;
		import java.util.ArrayList;
		import java.util.Date;
		import java.util.Properties;
		import java.util.Map.Entry;

		@@ -245,6 +246,10 @@ public class GpsLocationProvider extends ILocationProvider.Stub {
		// current setting - 5 minutes
		private static final long RETRY_INTERVAL = 5601000;

		// to avoid injecting bad NTP time, we reject any time fixes that differ from system time
		// by more than 5 minutes.
		private static final long MAX_NTP_SYSTEM_TIME_OFFSET = 5601000;

		private final IGpsStatusProvider mGpsStatusProvider = new IGpsStatusProvider.Stub() {
		public void addGpsStatusListener(IGpsStatusListener listener) throws RemoteException {
		if (listener == null) {
		@@ -1253,13 +1258,26 @@ public class GpsLocationProvider extends ILocationProvider.Stub {
		long time = client.getNtpTime();
		long timeReference = client.getNtpTimeReference();
		int certainty = (int)(client.getRoundTripTime()/2);
		long now = System.currentTimeMillis();
		long systemTimeOffset = time - now;

		if (Config.LOGD) Log.d(TAG, "calling native_inject_time: " +
		time + " reference: " + timeReference
		+ " certainty: " + certainty);
		Log.d(TAG, "NTP server returned: "
		+ time + " (" + new Date(time)
		+ ") reference: " + timeReference
		+ " certainty: " + certainty
		+ " system time offset: " + systemTimeOffset);

		// sanity check NTP time and do not use if it is too far from system time
		if (systemTimeOffset < 0) {
		systemTimeOffset = -systemTimeOffset;
		}
		if (systemTimeOffset < MAX_NTP_SYSTEM_TIME_OFFSET) {
		native_inject_time(time, timeReference, certainty);
		mNextNtpTime = System.currentTimeMillis() + NTP_INTERVAL;
		} else {
		Log.e(TAG, "NTP time differs from system time by " + systemTimeOffset
		+ "ms. Ignoring.");
		}
		mNextNtpTime = now + NTP_INTERVAL;
		} else {
		if (Config.LOGD) Log.d(TAG, "requestTime failed");
		mNextNtpTime = System.currentTimeMillis() + RETRY_INTERVAL;