DO NOT MERGE: IpConnectivityMetrics: rate limit ApfProgramEvents
This patch uses the previously introduced TokenBucket to rate limit
ApfProgramEvents, still allowing for burst of ApfProgramEvents when a
new interface is set up (due to ipv4 provisioning, multicast lock, ipv6 RAs
triggering new APF program events in short amounts of time).
Test: new test in IpConnectivityMetricsTest
Bug: 1550402
(cherry picked from commit e1c173d2240a8eedf7685c9371087dc047a6931f)
Change-Id: Idb640dec13ba64180985544b9709a586af66eb6e
diff --git a/core/java/android/net/IIpConnectivityMetrics.aidl b/core/java/android/net/IIpConnectivityMetrics.aidl
index 8f634bb..d36b766 100644
--- a/core/java/android/net/IIpConnectivityMetrics.aidl
+++ b/core/java/android/net/IIpConnectivityMetrics.aidl
@@ -23,7 +23,8 @@
interface IIpConnectivityMetrics {
/**
- * @return number of remaining available slots in buffer.
+ * @return the number of remaining available slots in buffer,
+ * or -1 if the event was dropped due to rate limiting.
*/
int logEvent(in ConnectivityMetricsEvent event);
}
diff --git a/core/tests/coretests/src/android/util/TokenBucketTest.java b/core/tests/coretests/src/android/util/TokenBucketTest.java
index a053ad3..f7ac20c 100644
--- a/core/tests/coretests/src/android/util/TokenBucketTest.java
+++ b/core/tests/coretests/src/android/util/TokenBucketTest.java
@@ -177,4 +177,3 @@
interface Fn { void call(); }
}
-
diff --git a/services/core/java/com/android/server/connectivity/IpConnectivityMetrics.java b/services/core/java/com/android/server/connectivity/IpConnectivityMetrics.java
index 642f2e0..be68173 100644
--- a/services/core/java/com/android/server/connectivity/IpConnectivityMetrics.java
+++ b/services/core/java/com/android/server/connectivity/IpConnectivityMetrics.java
@@ -19,15 +19,19 @@
import android.content.Context;
import android.net.ConnectivityMetricsEvent;
import android.net.IIpConnectivityMetrics;
+import android.net.metrics.ApfProgramEvent;
import android.net.metrics.IpConnectivityLog;
import android.os.IBinder;
import android.os.Parcelable;
import android.provider.Settings;
import android.text.TextUtils;
+import android.text.format.DateUtils;
+import android.util.ArrayMap;
import android.util.Base64;
import android.util.Log;
import com.android.internal.annotations.GuardedBy;
import com.android.internal.annotations.VisibleForTesting;
+import com.android.internal.util.TokenBucket;
import com.android.server.SystemService;
import java.io.FileDescriptor;
import java.io.IOException;
@@ -56,6 +60,8 @@
// Maximum size of the event buffer.
private static final int MAXIMUM_BUFFER_SIZE = DEFAULT_BUFFER_SIZE * 10;
+ private static final int ERROR_RATE_LIMITED = -1;
+
// Lock ensuring that concurrent manipulations of the event buffer are correct.
// There are three concurrent operations to synchronize:
// - appending events to the buffer.
@@ -73,6 +79,8 @@
private int mDropped;
@GuardedBy("mLock")
private int mCapacity;
+ @GuardedBy("mLock")
+ private final ArrayMap<Class<?>, TokenBucket> mBuckets = makeRateLimitingBuckets();
private final ToIntFunction<Context> mCapacityGetter;
@@ -122,6 +130,10 @@
if (event == null) {
return left;
}
+ if (isRateLimited(event)) {
+ // Do not count as a dropped event. TODO: consider adding separate counter
+ return ERROR_RATE_LIMITED;
+ }
if (left == 0) {
mDropped++;
return 0;
@@ -131,6 +143,11 @@
}
}
+ private boolean isRateLimited(ConnectivityMetricsEvent event) {
+ TokenBucket tb = mBuckets.get(event.data.getClass());
+ return (tb != null) && !tb.get();
+ }
+
private String flushEncodedOutput() {
final ArrayList<ConnectivityMetricsEvent> events;
final int dropped;
@@ -256,4 +273,11 @@
}
return Math.min(size, MAXIMUM_BUFFER_SIZE);
};
+
+ private static ArrayMap<Class<?>, TokenBucket> makeRateLimitingBuckets() {
+ ArrayMap<Class<?>, TokenBucket> map = new ArrayMap<>();
+ // one token every minute, 50 tokens max: burst of ~50 events every hour.
+ map.put(ApfProgramEvent.class, new TokenBucket((int)DateUtils.MINUTE_IN_MILLIS, 50));
+ return map;
+ }
}
diff --git a/tests/net/java/com/android/server/connectivity/IpConnectivityMetricsTest.java b/tests/net/java/com/android/server/connectivity/IpConnectivityMetricsTest.java
index 14b5cbe..aa491bb 100644
--- a/tests/net/java/com/android/server/connectivity/IpConnectivityMetricsTest.java
+++ b/tests/net/java/com/android/server/connectivity/IpConnectivityMetricsTest.java
@@ -19,6 +19,7 @@
import android.content.Context;
import android.net.ConnectivityMetricsEvent;
import android.net.IIpConnectivityMetrics;
+import android.net.metrics.ApfProgramEvent;
import android.net.metrics.ApfStats;
import android.net.metrics.DefaultNetworkEvent;
import android.net.metrics.DhcpClientEvent;
@@ -112,6 +113,27 @@
assertEquals("", output3);
}
+ public void testRateLimiting() {
+ final IpConnectivityLog logger = new IpConnectivityLog(mService.impl);
+ final ApfProgramEvent ev = new ApfProgramEvent(0, 0, 0, 0, 0);
+ final long fakeTimestamp = 1;
+
+ int attempt = 100; // More than burst quota, but less than buffer size.
+ for (int i = 0; i < attempt; i++) {
+ logger.log(ev);
+ }
+
+ String output1 = getdump("flush");
+ assertFalse("".equals(output1));
+
+ for (int i = 0; i < attempt; i++) {
+ assertFalse("expected event to be dropped", logger.log(fakeTimestamp, ev));
+ }
+
+ String output2 = getdump("flush");
+ assertEquals("", output2);
+ }
+
public void testEndToEndLogging() {
IpConnectivityLog logger = new IpConnectivityLog(mService.impl);