Merge changes from topic "dump_map_status"

* changes:
  Move Interface index name map dump to NetworkStatsService
  Move stats map A/B dump to NetworkStatsService
  Add BpfInterfaceMapUpdater#getIfNameByIndex
diff --git a/service-t/src/com/android/server/net/BpfInterfaceMapUpdater.java b/service-t/src/com/android/server/net/BpfInterfaceMapUpdater.java
index 3b44d81..57466a6 100644
--- a/service-t/src/com/android/server/net/BpfInterfaceMapUpdater.java
+++ b/service-t/src/com/android/server/net/BpfInterfaceMapUpdater.java
@@ -22,10 +22,12 @@
 import android.os.RemoteException;
 import android.os.ServiceSpecificException;
 import android.system.ErrnoException;
+import android.util.IndentingPrintWriter;
 import android.util.Log;
 
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.net.module.util.BaseNetdUnsolicitedEventListener;
+import com.android.net.module.util.BpfDump;
 import com.android.net.module.util.BpfMap;
 import com.android.net.module.util.IBpfMap;
 import com.android.net.module.util.InterfaceParams;
@@ -136,4 +138,37 @@
             mHandler.post(() -> addInterface(ifName));
         }
     }
+
+    /** get interface name by interface index from bpf map */
+    public String getIfNameByIndex(final long index) {
+        try {
+            final InterfaceMapValue value = mBpfMap.getValue(new U32(index));
+            if (value == null) {
+                Log.e(TAG, "No if name entry for index " + index);
+                return null;
+            }
+            return value.getInterfaceNameString();
+        } catch (ErrnoException e) {
+            Log.e(TAG, "Failed to get entry for index " + index + ": " + e);
+            return null;
+        }
+    }
+
+    /**
+     * Dump BPF map
+     *
+     * @param pw print writer
+     */
+    public void dump(final IndentingPrintWriter pw) {
+        pw.println("BPF map status:");
+        pw.increaseIndent();
+        BpfDump.dumpMapStatus(mBpfMap, pw, "IfaceIndexNameMap", IFACE_INDEX_NAME_MAP_PATH);
+        pw.decreaseIndent();
+        pw.println("BPF map content:");
+        pw.increaseIndent();
+        BpfDump.dumpMap(mBpfMap, pw, "IfaceIndexNameMap",
+                (key, value) -> "ifaceIndex=" + key.val
+                        + " ifaceName=" + value.getInterfaceNameString());
+        pw.decreaseIndent();
+    }
 }
diff --git a/service-t/src/com/android/server/net/InterfaceMapValue.java b/service-t/src/com/android/server/net/InterfaceMapValue.java
index 42c0044..95da981 100644
--- a/service-t/src/com/android/server/net/InterfaceMapValue.java
+++ b/service-t/src/com/android/server/net/InterfaceMapValue.java
@@ -16,20 +16,45 @@
 package com.android.server.net;
 
 import com.android.net.module.util.Struct;
-import com.android.net.module.util.Struct.Field;
-import com.android.net.module.util.Struct.Type;
+
+import java.util.Arrays;
 
 /**
  * The value of bpf interface index map which is used for NetworkStatsService.
  */
 public class InterfaceMapValue extends Struct {
+    private static final int IF_NAME_SIZE = 16;
+
     @Field(order = 0, type = Type.ByteArray, arraysize = 16)
     public final byte[] interfaceName;
 
     public InterfaceMapValue(String iface) {
-        final byte[] ifaceArray = iface.getBytes();
-        interfaceName = new byte[16];
         // All array bytes after the interface name, if any, must be 0.
-        System.arraycopy(ifaceArray, 0, interfaceName, 0, ifaceArray.length);
+        interfaceName = Arrays.copyOf(iface.getBytes(), IF_NAME_SIZE);
+    }
+
+    /**
+     * Constructor for Struct#parse. Build this struct from byte array of interface name.
+     *
+     * @param ifName Byte array of interface name, length is expected to be IF_NAME_SIZE(16).
+     *               If longer or shorter, interface name will be truncated or padded with zeros.
+     *               All array bytes after the interface name, if any, must be 0.
+     */
+    public InterfaceMapValue(final byte[] ifName) {
+        interfaceName = Arrays.copyOf(ifName, IF_NAME_SIZE);
+    }
+
+    /** Returns the length of the null-terminated string. */
+    private int strlen(byte[] str) {
+        for (int i = 0; i < str.length; ++i) {
+            if (str[i] == '\0') {
+                return i;
+            }
+        }
+        return str.length;
+    }
+
+    public String getInterfaceNameString() {
+        return new String(interfaceName, 0 /* offset */,  strlen(interfaceName));
     }
 }
diff --git a/service-t/src/com/android/server/net/NetworkStatsService.java b/service-t/src/com/android/server/net/NetworkStatsService.java
index 8d5c881..09eb54c 100644
--- a/service-t/src/com/android/server/net/NetworkStatsService.java
+++ b/service-t/src/com/android/server/net/NetworkStatsService.java
@@ -2741,6 +2741,12 @@
             }
 
             pw.println();
+            pw.println("InterfaceMapUpdater:");
+            pw.increaseIndent();
+            mInterfaceMapUpdater.dump(pw);
+            pw.decreaseIndent();
+
+            pw.println();
             pw.println("BPF map status:");
             pw.increaseIndent();
             dumpMapStatus(pw);
@@ -2755,6 +2761,8 @@
             dumpCookieTagMapLocked(pw);
             dumpUidCounterSetMapLocked(pw);
             dumpAppUidStatsMapLocked(pw);
+            dumpStatsMapLocked(mStatsMapA, pw, "mStatsMapA");
+            dumpStatsMapLocked(mStatsMapB, pw, "mStatsMapB");
             pw.decreaseIndent();
         }
     }
@@ -2840,6 +2848,8 @@
         pw.println("mUidCounterSetMap: "
                 + getMapStatus(mUidCounterSetMap, UID_COUNTERSET_MAP_PATH));
         pw.println("mAppUidStatsMap: " + getMapStatus(mAppUidStatsMap, APP_UID_STATS_MAP_PATH));
+        pw.println("mStatsMapA: " + getMapStatus(mStatsMapA, STATS_MAP_A_PATH));
+        pw.println("mStatsMapB: " + getMapStatus(mStatsMapB, STATS_MAP_B_PATH));
     }
 
     @GuardedBy("mStatsLock")
@@ -2876,6 +2886,30 @@
                         + value.txPackets);
     }
 
+    @GuardedBy("mStatsLock")
+    private void dumpStatsMapLocked(final IBpfMap<StatsMapKey, StatsMapValue> statsMap,
+            final IndentingPrintWriter pw, final String mapName) {
+        if (statsMap == null) {
+            return;
+        }
+
+        BpfDump.dumpMap(statsMap, pw, mapName,
+                "ifaceIndex ifaceName tag_hex uid_int cnt_set rxBytes rxPackets txBytes txPackets",
+                (key, value) -> {
+                    final long ifIndex = key.ifaceIndex;
+                    final String ifName = mInterfaceMapUpdater.getIfNameByIndex(ifIndex);
+                    return ifIndex + " "
+                            + (ifName != null ? ifName : "unknown") + " "
+                            + "0x" + Long.toHexString(key.tag) + " "
+                            + key.uid + " "
+                            + key.counterSet + " "
+                            + value.rxBytes + " "
+                            + value.rxPackets + " "
+                            + value.txBytes + " "
+                            + value.txPackets;
+                });
+    }
+
     private NetworkStats readNetworkStatsSummaryDev() {
         try {
             return mStatsFactory.readNetworkStatsSummaryDev();
diff --git a/service/native/TrafficController.cpp b/service/native/TrafficController.cpp
index 7fb1b34..49b23c9 100644
--- a/service/native/TrafficController.cpp
+++ b/service/native/TrafficController.cpp
@@ -647,48 +647,6 @@
         dw.println("mCookieTagMap print end with error: %s", res.error().message().c_str());
     }
 
-
-    // Print uidStatsMap content.
-    std::string statsHeader = StringPrintf("ifaceIndex ifaceName tag_hex uid_int cnt_set rxBytes"
-                                           " rxPackets txBytes txPackets");
-    dumpBpfMap("mStatsMapA", dw, statsHeader);
-    const auto printStatsInfo = [&dw, this](const StatsKey& key, const StatsValue& value,
-                                            const BpfMap<StatsKey, StatsValue>&) {
-        uint32_t ifIndex = key.ifaceIndex;
-        auto ifname = mIfaceIndexNameMap.readValue(ifIndex);
-        if (!ifname.ok()) {
-            ifname = IfaceValue{"unknown"};
-        }
-        dw.println("%u %s 0x%x %u %u %" PRIu64 " %" PRIu64 " %" PRIu64 " %" PRIu64, ifIndex,
-                   ifname.value().name, key.tag, key.uid, key.counterSet, value.rxBytes,
-                   value.rxPackets, value.txBytes, value.txPackets);
-        return base::Result<void>();
-    };
-    res = mStatsMapA.iterateWithValue(printStatsInfo);
-    if (!res.ok()) {
-        dw.println("mStatsMapA print end with error: %s", res.error().message().c_str());
-    }
-
-    // Print TagStatsMap content.
-    dumpBpfMap("mStatsMapB", dw, statsHeader);
-    res = mStatsMapB.iterateWithValue(printStatsInfo);
-    if (!res.ok()) {
-        dw.println("mStatsMapB print end with error: %s", res.error().message().c_str());
-    }
-
-    // Print ifaceIndexToNameMap content.
-    dumpBpfMap("mIfaceIndexNameMap", dw, "");
-    const auto printIfaceNameInfo = [&dw](const uint32_t& key, const IfaceValue& value,
-                                          const BpfMap<uint32_t, IfaceValue>&) {
-        const char* ifname = value.name;
-        dw.println("ifaceIndex=%u ifaceName=%s", key, ifname);
-        return base::Result<void>();
-    };
-    res = mIfaceIndexNameMap.iterateWithValue(printIfaceNameInfo);
-    if (!res.ok()) {
-        dw.println("mIfaceIndexNameMap print end with error: %s", res.error().message().c_str());
-    }
-
     // Print ifaceStatsMap content
     std::string ifaceStatsHeader = StringPrintf("ifaceIndex ifaceName rxBytes rxPackets txBytes"
                                                 " txPackets");
diff --git a/service/native/TrafficControllerTest.cpp b/service/native/TrafficControllerTest.cpp
index d08ffee..8525738 100644
--- a/service/native/TrafficControllerTest.cpp
+++ b/service/native/TrafficControllerTest.cpp
@@ -60,7 +60,6 @@
 constexpr uint32_t TEST_TAG = 42;
 constexpr uint32_t TEST_COUNTERSET = 1;
 constexpr int TEST_COOKIE = 1;
-constexpr char TEST_IFNAME[] = "test0";
 constexpr int TEST_IFINDEX = 999;
 constexpr int RXPACKETS = 1;
 constexpr int RXBYTES = 100;
@@ -792,17 +791,7 @@
     // 999 test0 0x2a 10086 1 100 1 0 0
     std::vector<std::string> expectedLines = {
         "mCookieTagMap:",
-        fmt::format("cookie={} tag={:#x} uid={}", TEST_COOKIE, TEST_TAG, TEST_UID),
-        "mStatsMapA",
-        "ifaceIndex ifaceName tag_hex uid_int cnt_set rxBytes rxPackets txBytes txPackets",
-        fmt::format("{} {} {:#x} {} {} {} {} {} {}",
-                    TEST_IFINDEX, TEST_IFNAME, TEST_TAG, TEST_UID, TEST_COUNTERSET, RXBYTES,
-                    RXPACKETS, TXBYTES, TXPACKETS)};
-
-    populateFakeIfaceIndexName(TEST_IFNAME, TEST_IFINDEX);
-    expectedLines.emplace_back("mIfaceIndexNameMap:");
-    expectedLines.emplace_back(fmt::format("ifaceIndex={} ifaceName={}",
-                                           TEST_IFINDEX, TEST_IFNAME));
+        fmt::format("cookie={} tag={:#x} uid={}", TEST_COOKIE, TEST_TAG, TEST_UID)};
 
     ASSERT_TRUE(isOk(updateUidOwnerMaps({TEST_UID}, HAPPY_BOX_MATCH,
                                         TrafficController::IptOpInsert)));
@@ -829,9 +818,6 @@
 
     std::vector<std::string> expectedLines = {
         fmt::format("mCookieTagMap {}", kErrIterate),
-        fmt::format("mStatsMapA {}", kErrIterate),
-        fmt::format("mStatsMapB {}", kErrIterate),
-        fmt::format("mIfaceIndexNameMap {}", kErrIterate),
         fmt::format("mIfaceStatsMap {}", kErrIterate),
         fmt::format("mConfigurationMap {}", kErrReadRulesConfig),
         fmt::format("mConfigurationMap {}", kErrReadStatsMapConfig),
diff --git a/tests/unit/java/com/android/server/net/BpfInterfaceMapUpdaterTest.java b/tests/unit/java/com/android/server/net/BpfInterfaceMapUpdaterTest.java
index c6852d1..83e6b5f 100644
--- a/tests/unit/java/com/android/server/net/BpfInterfaceMapUpdaterTest.java
+++ b/tests/unit/java/com/android/server/net/BpfInterfaceMapUpdaterTest.java
@@ -16,7 +16,14 @@
 
 package com.android.server.net;
 
+import static android.system.OsConstants.EPERM;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
 import static org.mockito.Matchers.eq;
+import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
 import static org.mockito.Mockito.when;
@@ -27,6 +34,8 @@
 import android.os.Build;
 import android.os.Handler;
 import android.os.test.TestLooper;
+import android.system.ErrnoException;
+import android.util.IndentingPrintWriter;
 
 import androidx.test.filters.SmallTest;
 
@@ -36,6 +45,7 @@
 import com.android.net.module.util.Struct.U32;
 import com.android.testutils.DevSdkIgnoreRule;
 import com.android.testutils.DevSdkIgnoreRunner;
+import com.android.testutils.TestBpfMap;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -44,6 +54,9 @@
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 
+import java.io.PrintWriter;
+import java.io.StringWriter;
+
 @SmallTest
 @RunWith(DevSdkIgnoreRunner.class)
 @DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
@@ -56,7 +69,8 @@
     private final TestLooper mLooper = new TestLooper();
     private BaseNetdUnsolicitedEventListener mListener;
     private BpfInterfaceMapUpdater mUpdater;
-    @Mock private IBpfMap<U32, InterfaceMapValue> mBpfMap;
+    private IBpfMap<U32, InterfaceMapValue> mBpfMap =
+            spy(new TestBpfMap<>(U32.class, InterfaceMapValue.class));
     @Mock private INetd mNetd;
     @Mock private Context mContext;
 
@@ -118,4 +132,43 @@
         mLooper.dispatchAll();
         verifyNoMoreInteractions(mBpfMap);
     }
+
+    @Test
+    public void testGetIfNameByIndex() throws Exception {
+        mBpfMap.updateEntry(new U32(TEST_INDEX), new InterfaceMapValue(TEST_INTERFACE_NAME));
+        assertEquals(TEST_INTERFACE_NAME, mUpdater.getIfNameByIndex(TEST_INDEX));
+    }
+
+    @Test
+    public void testGetIfNameByIndexNoEntry() {
+        assertNull(mUpdater.getIfNameByIndex(TEST_INDEX));
+    }
+
+    @Test
+    public void testGetIfNameByIndexException() throws Exception {
+        doThrow(new ErrnoException("", EPERM)).when(mBpfMap).getValue(new U32(TEST_INDEX));
+        assertNull(mUpdater.getIfNameByIndex(TEST_INDEX));
+    }
+
+    private void assertDumpContains(final String dump, final String message) {
+        assertTrue(String.format("dump(%s) does not contain '%s'", dump, message),
+                dump.contains(message));
+    }
+
+    private String getDump() {
+        final StringWriter sw = new StringWriter();
+        mUpdater.dump(new IndentingPrintWriter(new PrintWriter(sw), " "));
+        return sw.toString();
+    }
+
+    @Test
+    public void testDump() throws ErrnoException {
+        mBpfMap.updateEntry(new U32(TEST_INDEX), new InterfaceMapValue(TEST_INTERFACE_NAME));
+        mBpfMap.updateEntry(new U32(TEST_INDEX2), new InterfaceMapValue(TEST_INTERFACE_NAME2));
+
+        final String dump = getDump();
+        assertDumpContains(dump, "IfaceIndexNameMap: OK");
+        assertDumpContains(dump, "ifaceIndex=1 ifaceName=test1");
+        assertDumpContains(dump, "ifaceIndex=2 ifaceName=test2");
+    }
 }
diff --git a/tests/unit/java/com/android/server/net/InterfaceMapValueTest.java b/tests/unit/java/com/android/server/net/InterfaceMapValueTest.java
new file mode 100644
index 0000000..ee13d5f
--- /dev/null
+++ b/tests/unit/java/com/android/server/net/InterfaceMapValueTest.java
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2022 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.
+ */
+
+package com.android.server.net;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@RunWith(AndroidJUnit4.class)
+public class InterfaceMapValueTest {
+    private static final String IF_NAME = "wlan0";
+    private static final byte[] IF_NAME_BYTE = new byte[]{'w', 'l', 'a', 'n', '0'};
+    private static final byte[] IF_NAME_BYTE_WITH_PADDING =
+            new byte[]{'w', 'l', 'a', 'n', '0', 0, 0, 0,
+                    0, 0, 0, 0, 0, 0, 0, 0}; // IF_NAME_BYTE_WITH_PADDING.length = 16
+    private static final byte[] IF_NAME_BYTE_LONG =
+            new byte[]{'w', 'l', 'a', 'n', '0', 0, 0, 0,
+                    0, 0, 0, 0, 0, 0, 0, 0,
+                    0, 0, 0, 0, 0, 0, 0, 0}; // IF_NAME_BYTE_LONG.length = 24
+
+    @Test
+    public void testInterfaceMapValueFromString() {
+        final InterfaceMapValue value = new InterfaceMapValue(IF_NAME);
+        assertArrayEquals(IF_NAME_BYTE_WITH_PADDING, value.interfaceName);
+    }
+
+    @Test
+    public void testInterfaceMapValueFromByte() {
+        final InterfaceMapValue value = new InterfaceMapValue(IF_NAME_BYTE_WITH_PADDING);
+        assertArrayEquals(IF_NAME_BYTE_WITH_PADDING, value.interfaceName);
+    }
+
+    @Test
+    public void testInterfaceMapValueFromByteShort() {
+        final InterfaceMapValue value = new InterfaceMapValue(IF_NAME_BYTE);
+        assertArrayEquals(IF_NAME_BYTE_WITH_PADDING, value.interfaceName);
+    }
+
+    @Test
+    public void testInterfaceMapValueFromByteLong() {
+        final InterfaceMapValue value = new InterfaceMapValue(IF_NAME_BYTE_LONG);
+        assertArrayEquals(IF_NAME_BYTE_WITH_PADDING, value.interfaceName);
+    }
+
+    @Test
+    public void testGetInterfaceNameString() {
+        final InterfaceMapValue value = new InterfaceMapValue(IF_NAME_BYTE_WITH_PADDING);
+        assertEquals(IF_NAME, value.getInterfaceNameString());
+    }
+}
diff --git a/tests/unit/java/com/android/server/net/NetworkStatsServiceTest.java b/tests/unit/java/com/android/server/net/NetworkStatsServiceTest.java
index e27e4e2..fdbccba 100644
--- a/tests/unit/java/com/android/server/net/NetworkStatsServiceTest.java
+++ b/tests/unit/java/com/android/server/net/NetworkStatsServiceTest.java
@@ -2528,4 +2528,28 @@
         assertDumpContains(dump, "uid rxBytes rxPackets txBytes txPackets");
         assertDumpContains(dump, "1002 10000 10 6000 6");
     }
+
+    private void doTestDumpStatsMap(final String expectedIfaceName) throws ErrnoException {
+        initBpfMapsWithTagData(UID_BLUE);
+
+        final String dump = getDump();
+        assertDumpContains(dump, "mStatsMapA: OK");
+        assertDumpContains(dump, "mStatsMapB: OK");
+        assertDumpContains(dump,
+                "ifaceIndex ifaceName tag_hex uid_int cnt_set rxBytes rxPackets txBytes txPackets");
+        assertDumpContains(dump, "10 " + expectedIfaceName + " 0x2 1002 0 5000 5 3000 3");
+        assertDumpContains(dump, "10 " + expectedIfaceName + " 0x1 1002 0 5000 5 3000 3");
+    }
+
+    @Test
+    public void testDumpStatsMap() throws ErrnoException {
+        doReturn("wlan0").when(mBpfInterfaceMapUpdater).getIfNameByIndex(10 /* index */);
+        doTestDumpStatsMap("wlan0");
+    }
+
+    @Test
+    public void testDumpStatsMapUnknownInterface() throws ErrnoException {
+        doReturn(null).when(mBpfInterfaceMapUpdater).getIfNameByIndex(10 /* index */);
+        doTestDumpStatsMap("unknown");
+    }
 }