Dump counters in "dumpsys tethering bpf".
This CL adds the counters collected by the tethering programs to
the output of "dumpsys tethering bpf". The counter names are
fetched by JNI code at startup and then read by the debugging
code on demand.
Example from my device:
Forwarding errors:
TCP_CONTROL_PACKET: 67
NON_GLOBAL_SRC: 13
NON_GLOBAL_DST: 17
LOCAL_SRC_DST: 7
Test: manual (debug-only code)
Change-Id: I7ec7992612556a4bca5f1b6bb52c655d6d870201
diff --git a/Tethering/jni/com_android_networkstack_tethering_BpfCoordinator.cpp b/Tethering/jni/com_android_networkstack_tethering_BpfCoordinator.cpp
new file mode 100644
index 0000000..27357f8
--- /dev/null
+++ b/Tethering/jni/com_android_networkstack_tethering_BpfCoordinator.cpp
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2021 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 <jni.h>
+#include <nativehelper/JNIHelp.h>
+
+#include "bpf_tethering.h"
+
+namespace android {
+
+static jobjectArray getBpfCounterNames(JNIEnv *env) {
+ size_t size = BPF_TETHER_ERR__MAX;
+ jobjectArray ret = env->NewObjectArray(size, env->FindClass("java/lang/String"), nullptr);
+ for (int i = 0; i < size; i++) {
+ env->SetObjectArrayElement(ret, i, env->NewStringUTF(bpf_tether_errors[i]));
+ }
+ return ret;
+}
+
+/*
+ * JNI registration.
+ */
+static const JNINativeMethod gMethods[] = {
+ /* name, signature, funcPtr */
+ { "getBpfCounterNames", "()[Ljava/lang/String;", (void*) getBpfCounterNames },
+};
+
+int register_com_android_networkstack_tethering_BpfCoordinator(JNIEnv* env) {
+ return jniRegisterNativeMethods(env,
+ "com/android/networkstack/tethering/BpfCoordinator",
+ gMethods, NELEM(gMethods));
+}
+
+}; // namespace android
diff --git a/Tethering/jni/onload.cpp b/Tethering/jni/onload.cpp
index 3766de9..e31da60 100644
--- a/Tethering/jni/onload.cpp
+++ b/Tethering/jni/onload.cpp
@@ -24,6 +24,7 @@
int register_android_net_util_TetheringUtils(JNIEnv* env);
int register_com_android_networkstack_tethering_BpfMap(JNIEnv* env);
+int register_com_android_networkstack_tethering_BpfCoordinator(JNIEnv* env);
extern "C" jint JNI_OnLoad(JavaVM* vm, void*) {
JNIEnv *env;
@@ -36,6 +37,8 @@
if (register_com_android_networkstack_tethering_BpfMap(env) < 0) return JNI_ERR;
+ if (register_com_android_networkstack_tethering_BpfCoordinator(env) < 0) return JNI_ERR;
+
return JNI_VERSION_1_6;
}
diff --git a/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java b/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
index 4ba5130..985328f 100644
--- a/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
+++ b/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
@@ -59,6 +59,7 @@
import com.android.internal.util.IndentingPrintWriter;
import com.android.modules.utils.build.SdkLevel;
import com.android.net.module.util.NetworkStackConstants;
+import com.android.net.module.util.Struct;
import com.android.networkstack.tethering.apishim.common.BpfCoordinatorShim;
import java.net.Inet4Address;
@@ -84,6 +85,13 @@
* @hide
*/
public class BpfCoordinator {
+ // Ensure the JNI code is loaded. In production this will already have been loaded by
+ // TetherService, but for tests it needs to be either loaded here or loaded by every test.
+ // TODO: is there a better way?
+ static {
+ System.loadLibrary("tetherutilsjni");
+ }
+
static final boolean DOWNSTREAM = true;
static final boolean UPSTREAM = false;
@@ -97,6 +105,10 @@
private static final String TETHER_UPSTREAM6_FS_PATH = makeMapPath(UPSTREAM, 6);
private static final String TETHER_STATS_MAP_PATH = makeMapPath("stats");
private static final String TETHER_LIMIT_MAP_PATH = makeMapPath("limit");
+ private static final String TETHER_ERROR_MAP_PATH = makeMapPath("error");
+
+ /** The names of all the BPF counters defined in bpf_tethering.h. */
+ public static final String[] sBpfCounterNames = getBpfCounterNames();
private static String makeMapPath(String which) {
return "/sys/fs/bpf/tethering/map_offload_tether_" + which + "_map";
@@ -717,6 +729,12 @@
dumpIpv4ForwardingRules(pw);
pw.decreaseIndent();
+ pw.println();
+ pw.println("Forwarding counters:");
+ pw.increaseIndent();
+ dumpCounters(pw);
+ pw.decreaseIndent();
+
dumpDone.open();
});
if (!dumpDone.block(DUMP_TIMEOUT_MS)) {
@@ -814,6 +832,36 @@
pw.decreaseIndent();
}
+ /**
+ * Simple struct that only contains a u32. Must be public because Struct needs access to it.
+ * TODO: make this a public inner class of Struct so anyone can use it as, e.g., Struct.U32?
+ */
+ public static class U32Struct extends Struct {
+ @Struct.Field(order = 0, type = Struct.Type.U32)
+ public long val;
+ }
+
+ private void dumpCounters(@NonNull IndentingPrintWriter pw) {
+ try (BpfMap<U32Struct, U32Struct> map = new BpfMap<>(TETHER_ERROR_MAP_PATH,
+ BpfMap.BPF_F_RDONLY, U32Struct.class, U32Struct.class)) {
+
+ map.forEach((k, v) -> {
+ String counterName;
+ try {
+ counterName = sBpfCounterNames[(int) k.val];
+ } catch (IndexOutOfBoundsException e) {
+ // Should never happen because this code gets the counter name from the same
+ // include file as the BPF program that increments the counter.
+ Log.wtf(TAG, "Unknown tethering counter type " + k.val);
+ counterName = Long.toString(k.val);
+ }
+ if (v.val > 0) pw.println(String.format("%s: %d", counterName, v.val));
+ });
+ } catch (ErrnoException e) {
+ pw.println("Error dumping counter map: " + e);
+ }
+ }
+
/** IPv6 forwarding rule class. */
public static class Ipv6ForwardingRule {
public final int upstreamIfindex;
@@ -1296,4 +1344,6 @@
final SparseArray<String> getInterfaceNamesForTesting() {
return mInterfaceNames;
}
+
+ private static native String[] getBpfCounterNames();
}
diff --git a/Tethering/tests/unit/Android.bp b/Tethering/tests/unit/Android.bp
index 5e4fe52..6c479a0 100644
--- a/Tethering/tests/unit/Android.bp
+++ b/Tethering/tests/unit/Android.bp
@@ -69,6 +69,7 @@
// For mockito extended
"libdexmakerjvmtiagent",
"libstaticjvmtiagent",
+ "libtetherutilsjni",
],
}