Fix the build problem in netd

With the main bpf library moved into system/bpf, the rest of the netd
only bpf files are renamed into libnetdbpf. Fixed some dependency issue
on the new libbpf outside netd.

Test: BpfBasicTest libbpf_test netd_unit_test netd_integration_test
Bug: 112334572
Change-Id: I71f2c5285fee6fe96e0db55578dc618d16444d98
diff --git a/libnetdbpf/BpfNetworkStatsTest.cpp b/libnetdbpf/BpfNetworkStatsTest.cpp
new file mode 100644
index 0000000..64dc7d4
--- /dev/null
+++ b/libnetdbpf/BpfNetworkStatsTest.cpp
@@ -0,0 +1,444 @@
+/*
+ * Copyright (C) 2018 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 <fstream>
+#include <iostream>
+#include <string>
+#include <vector>
+
+#include <fcntl.h>
+#include <inttypes.h>
+#include <linux/inet_diag.h>
+#include <linux/sock_diag.h>
+#include <net/if.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <gtest/gtest.h>
+
+#include <android-base/stringprintf.h>
+#include <android-base/strings.h>
+
+#include <netdutils/MockSyscalls.h>
+#include "bpf/BpfMap.h"
+#include "bpf/BpfUtils.h"
+#include "netdbpf/BpfNetworkStats.h"
+
+using namespace android::bpf;
+
+using ::testing::_;
+using ::testing::ByMove;
+using ::testing::Invoke;
+using ::testing::Return;
+using ::testing::StrictMock;
+using ::testing::Test;
+
+namespace android {
+namespace bpf {
+
+using base::unique_fd;
+
+constexpr int TEST_MAP_SIZE = 10;
+constexpr uid_t TEST_UID1 = 10086;
+constexpr uid_t TEST_UID2 = 12345;
+constexpr uint32_t TEST_TAG = 42;
+constexpr int TEST_COUNTERSET0 = 0;
+constexpr int TEST_COUNTERSET1 = 1;
+constexpr uint64_t TEST_BYTES0 = 1000;
+constexpr uint64_t TEST_BYTES1 = 2000;
+constexpr uint64_t TEST_PACKET0 = 100;
+constexpr uint64_t TEST_PACKET1 = 200;
+constexpr const char IFACE_NAME1[] = "lo";
+constexpr const char IFACE_NAME2[] = "wlan0";
+constexpr const char IFACE_NAME3[] = "rmnet_data0";
+// A iface name that the size is bigger then IFNAMSIZ
+constexpr const char LONG_IFACE_NAME[] = "wlanWithALongName";
+constexpr const char TRUNCATED_IFACE_NAME[] = "wlanWithALongNa";
+constexpr uint32_t IFACE_INDEX1 = 1;
+constexpr uint32_t IFACE_INDEX2 = 2;
+constexpr uint32_t IFACE_INDEX3 = 3;
+constexpr uint32_t IFACE_INDEX4 = 4;
+constexpr uint32_t UNKNOWN_IFACE = 0;
+
+class BpfNetworkStatsHelperTest : public testing::Test {
+  protected:
+    BpfNetworkStatsHelperTest() {}
+    BpfMap<uint64_t, UidTag> mFakeCookieTagMap;
+    BpfMap<uint32_t, StatsValue> mFakeAppUidStatsMap;
+    BpfMap<StatsKey, StatsValue> mFakeUidStatsMap;
+    BpfMap<StatsKey, StatsValue> mFakeTagStatsMap;
+    BpfMap<uint32_t, IfaceValue> mFakeIfaceIndexNameMap;
+    BpfMap<uint32_t, StatsValue> mFakeIfaceStatsMap;
+
+    void SetUp() {
+        mFakeCookieTagMap = BpfMap<uint64_t, UidTag>(createMap(
+            BPF_MAP_TYPE_HASH, sizeof(uint64_t), sizeof(struct UidTag), TEST_MAP_SIZE, 0));
+        ASSERT_LE(0, mFakeCookieTagMap.getMap());
+
+        mFakeAppUidStatsMap = BpfMap<uint32_t, StatsValue>(createMap(
+            BPF_MAP_TYPE_HASH, sizeof(uint32_t), sizeof(struct StatsValue), TEST_MAP_SIZE, 0));
+        ASSERT_LE(0, mFakeAppUidStatsMap.getMap());
+
+        mFakeUidStatsMap =
+            BpfMap<StatsKey, StatsValue>(createMap(BPF_MAP_TYPE_HASH, sizeof(struct StatsKey),
+                                                   sizeof(struct StatsValue), TEST_MAP_SIZE, 0));
+        ASSERT_LE(0, mFakeUidStatsMap.getMap());
+
+        mFakeTagStatsMap =
+            BpfMap<StatsKey, StatsValue>(createMap(BPF_MAP_TYPE_HASH, sizeof(struct StatsKey),
+                                                   sizeof(struct StatsValue), TEST_MAP_SIZE, 0));
+        ASSERT_LE(0, mFakeTagStatsMap.getMap());
+
+        mFakeIfaceIndexNameMap = BpfMap<uint32_t, IfaceValue>(
+            createMap(BPF_MAP_TYPE_HASH, sizeof(uint32_t), sizeof(IfaceValue), TEST_MAP_SIZE, 0));
+        ASSERT_LE(0, mFakeIfaceIndexNameMap.getMap());
+
+        mFakeIfaceStatsMap = BpfMap<uint32_t, StatsValue>(createMap(
+            BPF_MAP_TYPE_HASH, sizeof(uint32_t), sizeof(struct StatsValue), TEST_MAP_SIZE, 0));
+        ASSERT_LE(0, mFakeIfaceStatsMap.getMap());
+    }
+
+    void expectUidTag(uint64_t cookie, uid_t uid, uint32_t tag) {
+        auto tagResult = mFakeCookieTagMap.readValue(cookie);
+        EXPECT_TRUE(isOk(tagResult));
+        EXPECT_EQ(uid, tagResult.value().uid);
+        EXPECT_EQ(tag, tagResult.value().tag);
+    }
+
+    void populateFakeStats(uid_t uid, uint32_t tag, uint32_t ifaceIndex, uint32_t counterSet,
+                           StatsValue value, BpfMap<StatsKey, StatsValue>& map) {
+        StatsKey key = {
+            .uid = (uint32_t)uid, .tag = tag, .counterSet = counterSet, .ifaceIndex = ifaceIndex};
+        EXPECT_TRUE(isOk(map.writeValue(key, value, BPF_ANY)));
+    }
+
+    void updateIfaceMap(const char* ifaceName, uint32_t ifaceIndex) {
+        IfaceValue iface;
+        strlcpy(iface.name, ifaceName, IFNAMSIZ);
+        EXPECT_TRUE(isOk(mFakeIfaceIndexNameMap.writeValue(ifaceIndex, iface, BPF_ANY)));
+    }
+
+    void expectStatsEqual(const StatsValue& target, const Stats& result) {
+        EXPECT_EQ(target.rxPackets, result.rxPackets);
+        EXPECT_EQ(target.rxBytes, result.rxBytes);
+        EXPECT_EQ(target.txPackets, result.txPackets);
+        EXPECT_EQ(target.txBytes, result.txBytes);
+    }
+
+    void expectStatsLineEqual(const StatsValue target, const char* iface, uint32_t uid,
+                              int counterSet, uint32_t tag, const stats_line& result) {
+        EXPECT_EQ(0, strcmp(iface, result.iface));
+        EXPECT_EQ(uid, (uint32_t)result.uid);
+        EXPECT_EQ(counterSet, result.set);
+        EXPECT_EQ(tag, (uint32_t)result.tag);
+        EXPECT_EQ(target.rxPackets, (uint64_t)result.rxPackets);
+        EXPECT_EQ(target.rxBytes, (uint64_t)result.rxBytes);
+        EXPECT_EQ(target.txPackets, (uint64_t)result.txPackets);
+        EXPECT_EQ(target.txBytes, (uint64_t)result.txBytes);
+    }
+};
+
+// TEST to verify the behavior of bpf map when cocurrent deletion happens when
+// iterating the same map.
+TEST_F(BpfNetworkStatsHelperTest, TestIterateMapWithDeletion) {
+    SKIP_IF_BPF_NOT_SUPPORTED;
+
+    for (int i = 0; i < 5; i++) {
+        uint64_t cookie = i + 1;
+        struct UidTag tag = {.uid = TEST_UID1, .tag = TEST_TAG};
+        EXPECT_TRUE(isOk(mFakeCookieTagMap.writeValue(cookie, tag, BPF_ANY)));
+    }
+    uint64_t curCookie = 0;
+    auto nextCookie = mFakeCookieTagMap.getNextKey(curCookie);
+    EXPECT_TRUE(isOk(nextCookie));
+    uint64_t headOfMap = nextCookie.value();
+    curCookie = nextCookie.value();
+    // Find the second entry in the map, then immediately delete it.
+    nextCookie = mFakeCookieTagMap.getNextKey(curCookie);
+    EXPECT_TRUE(isOk(nextCookie));
+    EXPECT_TRUE(isOk(mFakeCookieTagMap.deleteValue((nextCookie.value()))));
+    // Find the entry that is now immediately after headOfMap, then delete that.
+    nextCookie = mFakeCookieTagMap.getNextKey(curCookie);
+    EXPECT_TRUE(isOk(nextCookie));
+    EXPECT_TRUE(isOk(mFakeCookieTagMap.deleteValue((nextCookie.value()))));
+    // Attempting to read an entry that has been deleted fails with ENOENT.
+    curCookie = nextCookie.value();
+    auto tagResult = mFakeCookieTagMap.readValue(curCookie);
+    EXPECT_EQ(ENOENT, tagResult.status().code());
+    // Finding the entry after our deleted entry restarts iteration from the beginning of the map.
+    nextCookie = mFakeCookieTagMap.getNextKey(curCookie);
+    EXPECT_TRUE(isOk(nextCookie));
+    EXPECT_EQ(headOfMap, nextCookie.value());
+}
+
+TEST_F(BpfNetworkStatsHelperTest, TestBpfIterateMap) {
+    SKIP_IF_BPF_NOT_SUPPORTED;
+
+    for (int i = 0; i < 5; i++) {
+        uint64_t cookie = i + 1;
+        struct UidTag tag = {.uid = TEST_UID1, .tag = TEST_TAG};
+        EXPECT_TRUE(isOk(mFakeCookieTagMap.writeValue(cookie, tag, BPF_ANY)));
+    }
+    int totalCount = 0;
+    int totalSum = 0;
+    const auto iterateWithoutDeletion = [&totalCount, &totalSum](const uint64_t& key,
+                                                                 const BpfMap<uint64_t, UidTag>&) {
+        EXPECT_GE((uint64_t)5, key);
+        totalCount++;
+        totalSum += key;
+        return netdutils::status::ok;
+    };
+    EXPECT_TRUE(isOk(mFakeCookieTagMap.iterate(iterateWithoutDeletion)));
+    EXPECT_EQ(5, totalCount);
+    EXPECT_EQ(1 + 2 + 3 + 4 + 5, totalSum);
+}
+
+TEST_F(BpfNetworkStatsHelperTest, TestGetUidStatsTotal) {
+    SKIP_IF_BPF_NOT_SUPPORTED;
+
+    updateIfaceMap(IFACE_NAME1, IFACE_INDEX1);
+    updateIfaceMap(IFACE_NAME2, IFACE_INDEX2);
+    updateIfaceMap(IFACE_NAME3, IFACE_INDEX3);
+    StatsValue value1 = {.rxBytes = TEST_BYTES0,
+                         .rxPackets = TEST_PACKET0,
+                         .txBytes = TEST_BYTES1,
+                         .txPackets = TEST_PACKET1,};
+    StatsValue value2 = {
+        .rxBytes = TEST_BYTES0 * 2,
+        .rxPackets = TEST_PACKET0 * 2,
+        .txBytes = TEST_BYTES1 * 2,
+        .txPackets = TEST_PACKET1 * 2,
+    };
+    ASSERT_TRUE(isOk(mFakeAppUidStatsMap.writeValue(TEST_UID1, value1, BPF_ANY)));
+    ASSERT_TRUE(isOk(mFakeAppUidStatsMap.writeValue(TEST_UID2, value2, BPF_ANY)));
+    Stats result1 = {};
+    ASSERT_EQ(0, bpfGetUidStatsInternal(TEST_UID1, &result1, mFakeAppUidStatsMap));
+    expectStatsEqual(value1, result1);
+
+    Stats result2 = {};
+    ASSERT_EQ(0, bpfGetUidStatsInternal(TEST_UID2, &result2, mFakeAppUidStatsMap));
+    expectStatsEqual(value2, result2);
+    std::vector<stats_line> lines;
+    std::vector<std::string> ifaces;
+    populateFakeStats(TEST_UID1, 0, IFACE_INDEX1, TEST_COUNTERSET0, value1, mFakeUidStatsMap);
+    populateFakeStats(TEST_UID1, 0, IFACE_INDEX2, TEST_COUNTERSET1, value1, mFakeUidStatsMap);
+    populateFakeStats(TEST_UID2, 0, IFACE_INDEX3, TEST_COUNTERSET1, value1, mFakeUidStatsMap);
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TAG_ALL, TEST_UID1,
+                                                    mFakeUidStatsMap, mFakeIfaceIndexNameMap));
+    ASSERT_EQ((unsigned long)2, lines.size());
+    lines.clear();
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TAG_ALL, TEST_UID2,
+                                                    mFakeUidStatsMap, mFakeIfaceIndexNameMap));
+    ASSERT_EQ((unsigned long)1, lines.size());
+    expectStatsLineEqual(value1, IFACE_NAME3, TEST_UID2, TEST_COUNTERSET1, 0, lines.front());
+}
+
+TEST_F(BpfNetworkStatsHelperTest, TestGetIfaceStatsInternal) {
+    SKIP_IF_BPF_NOT_SUPPORTED;
+
+    updateIfaceMap(IFACE_NAME1, IFACE_INDEX1);
+    updateIfaceMap(IFACE_NAME2, IFACE_INDEX2);
+    updateIfaceMap(IFACE_NAME3, IFACE_INDEX3);
+    StatsValue value1 = {
+        .rxBytes = TEST_BYTES0,
+        .rxPackets = TEST_PACKET0,
+        .txBytes = TEST_BYTES1,
+        .txPackets = TEST_PACKET1,
+    };
+    StatsValue value2 = {
+        .rxBytes = TEST_BYTES1,
+        .rxPackets = TEST_PACKET1,
+        .txBytes = TEST_BYTES0,
+        .txPackets = TEST_PACKET0,
+    };
+    uint32_t ifaceStatsKey = IFACE_INDEX1;
+    EXPECT_TRUE(isOk(mFakeIfaceStatsMap.writeValue(ifaceStatsKey, value1, BPF_ANY)));
+    ifaceStatsKey = IFACE_INDEX2;
+    EXPECT_TRUE(isOk(mFakeIfaceStatsMap.writeValue(ifaceStatsKey, value2, BPF_ANY)));
+    ifaceStatsKey = IFACE_INDEX3;
+    EXPECT_TRUE(isOk(mFakeIfaceStatsMap.writeValue(ifaceStatsKey, value1, BPF_ANY)));
+
+    Stats result1 = {};
+    ASSERT_EQ(0, bpfGetIfaceStatsInternal(IFACE_NAME1, &result1, mFakeIfaceStatsMap,
+                                          mFakeIfaceIndexNameMap));
+    expectStatsEqual(value1, result1);
+    Stats result2 = {};
+    ASSERT_EQ(0, bpfGetIfaceStatsInternal(IFACE_NAME2, &result2, mFakeIfaceStatsMap,
+                                          mFakeIfaceIndexNameMap));
+    expectStatsEqual(value2, result2);
+    Stats totalResult = {};
+    ASSERT_EQ(0, bpfGetIfaceStatsInternal(NULL, &totalResult, mFakeIfaceStatsMap,
+                                          mFakeIfaceIndexNameMap));
+    StatsValue totalValue = {
+        .rxBytes = TEST_BYTES0 * 2 + TEST_BYTES1,
+        .rxPackets = TEST_PACKET0 * 2 + TEST_PACKET1,
+        .txBytes = TEST_BYTES1 * 2 + TEST_BYTES0,
+        .txPackets = TEST_PACKET1 * 2 + TEST_PACKET0,
+    };
+    expectStatsEqual(totalValue, totalResult);
+}
+
+TEST_F(BpfNetworkStatsHelperTest, TestGetStatsDetail) {
+    SKIP_IF_BPF_NOT_SUPPORTED;
+
+    updateIfaceMap(IFACE_NAME1, IFACE_INDEX1);
+    updateIfaceMap(IFACE_NAME2, IFACE_INDEX2);
+    StatsValue value1 = {.rxBytes = TEST_BYTES0,
+                         .rxPackets = TEST_PACKET0,
+                         .txBytes = TEST_BYTES1,
+                         .txPackets = TEST_PACKET1,};
+    populateFakeStats(TEST_UID1, TEST_TAG, IFACE_INDEX1, TEST_COUNTERSET0, value1, mFakeTagStatsMap);
+    populateFakeStats(TEST_UID1, TEST_TAG, IFACE_INDEX2, TEST_COUNTERSET0, value1, mFakeTagStatsMap);
+    populateFakeStats(TEST_UID1, TEST_TAG + 1, IFACE_INDEX1, TEST_COUNTERSET0, value1,
+                      mFakeTagStatsMap);
+    populateFakeStats(TEST_UID2, TEST_TAG, IFACE_INDEX1, TEST_COUNTERSET0, value1, mFakeTagStatsMap);
+    std::vector<stats_line> lines;
+    std::vector<std::string> ifaces;
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TAG_ALL, UID_ALL,
+                                                    mFakeTagStatsMap, mFakeIfaceIndexNameMap));
+    ASSERT_EQ((unsigned long)4, lines.size());
+    lines.clear();
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TAG_ALL, TEST_UID1,
+                                                    mFakeTagStatsMap, mFakeIfaceIndexNameMap));
+    ASSERT_EQ((unsigned long)3, lines.size());
+    lines.clear();
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TEST_TAG, TEST_UID1,
+                                                    mFakeTagStatsMap, mFakeIfaceIndexNameMap));
+    ASSERT_EQ((unsigned long)2, lines.size());
+    lines.clear();
+    ifaces.push_back(std::string(IFACE_NAME1));
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TEST_TAG, TEST_UID1,
+                                                    mFakeTagStatsMap, mFakeIfaceIndexNameMap));
+    ASSERT_EQ((unsigned long)1, lines.size());
+    expectStatsLineEqual(value1, IFACE_NAME1, TEST_UID1, TEST_COUNTERSET0, TEST_TAG, lines.front());
+}
+
+TEST_F(BpfNetworkStatsHelperTest, TestGetStatsWithSkippedIface) {
+    SKIP_IF_BPF_NOT_SUPPORTED;
+
+    updateIfaceMap(IFACE_NAME1, IFACE_INDEX1);
+    updateIfaceMap(IFACE_NAME2, IFACE_INDEX2);
+    StatsValue value1 = {.rxBytes = TEST_BYTES0,
+                         .rxPackets = TEST_PACKET0,
+                         .txBytes = TEST_BYTES1,
+                         .txPackets = TEST_PACKET1,};
+    populateFakeStats(0, 0, 0, OVERFLOW_COUNTERSET, value1, mFakeUidStatsMap);
+    populateFakeStats(TEST_UID1, 0, IFACE_INDEX1, TEST_COUNTERSET0, value1, mFakeUidStatsMap);
+    populateFakeStats(TEST_UID1, 0, IFACE_INDEX2, TEST_COUNTERSET0, value1, mFakeUidStatsMap);
+    populateFakeStats(TEST_UID1, 0, IFACE_INDEX1, TEST_COUNTERSET1, value1, mFakeUidStatsMap);
+    populateFakeStats(TEST_UID2, 0, IFACE_INDEX1, TEST_COUNTERSET0, value1, mFakeUidStatsMap);
+    std::vector<stats_line> lines;
+    std::vector<std::string> ifaces;
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TAG_ALL, UID_ALL,
+                                                    mFakeUidStatsMap, mFakeIfaceIndexNameMap));
+    ASSERT_EQ((unsigned long)4, lines.size());
+    lines.clear();
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TAG_ALL, TEST_UID1,
+                                                    mFakeUidStatsMap, mFakeIfaceIndexNameMap));
+    ASSERT_EQ((unsigned long)3, lines.size());
+    lines.clear();
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TAG_ALL, TEST_UID2,
+                                                    mFakeUidStatsMap, mFakeIfaceIndexNameMap));
+    ASSERT_EQ((unsigned long)1, lines.size());
+    expectStatsLineEqual(value1, IFACE_NAME1, TEST_UID2, TEST_COUNTERSET0, 0, lines.front());
+    lines.clear();
+    ifaces.push_back(std::string(IFACE_NAME1));
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TAG_ALL, TEST_UID1,
+                                                    mFakeUidStatsMap, mFakeIfaceIndexNameMap));
+    ASSERT_EQ((unsigned long)2, lines.size());
+}
+
+TEST_F(BpfNetworkStatsHelperTest, TestUnkownIfaceError) {
+    SKIP_IF_BPF_NOT_SUPPORTED;
+
+    updateIfaceMap(IFACE_NAME1, IFACE_INDEX1);
+    StatsValue value1 = {.rxBytes = TEST_BYTES0 * 20,
+                         .rxPackets = TEST_PACKET0,
+                         .txBytes = TEST_BYTES1 * 20,
+                         .txPackets = TEST_PACKET1,};
+    uint32_t ifaceIndex = UNKNOWN_IFACE;
+    populateFakeStats(TEST_UID1, 0, ifaceIndex, TEST_COUNTERSET0, value1, mFakeUidStatsMap);
+    populateFakeStats(TEST_UID1, 0, IFACE_INDEX1, TEST_COUNTERSET0, value1, mFakeUidStatsMap);
+    StatsValue value2 = {.rxBytes = TEST_BYTES0 * 40,
+                         .rxPackets = TEST_PACKET0,
+                         .txBytes = TEST_BYTES1 * 40,
+                         .txPackets = TEST_PACKET1,};
+    populateFakeStats(TEST_UID1, 0, IFACE_INDEX2, TEST_COUNTERSET0, value2, mFakeUidStatsMap);
+    StatsKey curKey = {.uid = TEST_UID1,
+                       .tag = 0,
+                       .ifaceIndex = ifaceIndex,
+                       .counterSet = TEST_COUNTERSET0};
+    char ifname[IFNAMSIZ];
+    int64_t unknownIfaceBytesTotal = 0;
+    ASSERT_EQ(-ENODEV, getIfaceNameFromMap(mFakeIfaceIndexNameMap, mFakeUidStatsMap, ifaceIndex,
+                                           ifname, curKey, &unknownIfaceBytesTotal));
+    ASSERT_EQ(((int64_t)(TEST_BYTES0 * 20 + TEST_BYTES1 * 20)), unknownIfaceBytesTotal);
+    curKey.ifaceIndex = IFACE_INDEX2;
+    ASSERT_EQ(-ENODEV, getIfaceNameFromMap(mFakeIfaceIndexNameMap, mFakeUidStatsMap, ifaceIndex,
+                                           ifname, curKey, &unknownIfaceBytesTotal));
+    ASSERT_EQ(-1, unknownIfaceBytesTotal);
+    std::vector<stats_line> lines;
+    std::vector<std::string> ifaces;
+    // TODO: find a way to test the total of unknown Iface Bytes go above limit.
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TAG_ALL, UID_ALL,
+                                                    mFakeUidStatsMap, mFakeIfaceIndexNameMap));
+    ASSERT_EQ((unsigned long)1, lines.size());
+    expectStatsLineEqual(value1, IFACE_NAME1, TEST_UID1, TEST_COUNTERSET0, 0, lines.front());
+}
+
+TEST_F(BpfNetworkStatsHelperTest, TestGetIfaceStatsDetail) {
+    SKIP_IF_BPF_NOT_SUPPORTED;
+
+    updateIfaceMap(IFACE_NAME1, IFACE_INDEX1);
+    updateIfaceMap(IFACE_NAME2, IFACE_INDEX2);
+    updateIfaceMap(IFACE_NAME3, IFACE_INDEX3);
+    updateIfaceMap(LONG_IFACE_NAME, IFACE_INDEX4);
+    StatsValue value1 = {
+        .rxBytes = TEST_BYTES0,
+        .rxPackets = TEST_PACKET0,
+        .txBytes = TEST_BYTES1,
+        .txPackets = TEST_PACKET1,
+    };
+    StatsValue value2 = {
+        .rxBytes = TEST_BYTES1,
+        .rxPackets = TEST_PACKET1,
+        .txBytes = TEST_BYTES0,
+        .txPackets = TEST_PACKET0,
+    };
+    uint32_t ifaceStatsKey = IFACE_INDEX1;
+    EXPECT_TRUE(isOk(mFakeIfaceStatsMap.writeValue(ifaceStatsKey, value1, BPF_ANY)));
+    ifaceStatsKey = IFACE_INDEX2;
+    EXPECT_TRUE(isOk(mFakeIfaceStatsMap.writeValue(ifaceStatsKey, value2, BPF_ANY)));
+    ifaceStatsKey = IFACE_INDEX3;
+    EXPECT_TRUE(isOk(mFakeIfaceStatsMap.writeValue(ifaceStatsKey, value1, BPF_ANY)));
+    ifaceStatsKey = IFACE_INDEX4;
+    EXPECT_TRUE(isOk(mFakeIfaceStatsMap.writeValue(ifaceStatsKey, value2, BPF_ANY)));
+    std::vector<stats_line> lines;
+    ASSERT_EQ(0,
+              parseBpfNetworkStatsDevInternal(&lines, mFakeIfaceStatsMap, mFakeIfaceIndexNameMap));
+    ASSERT_EQ((unsigned long)4, lines.size());
+    std::sort(lines.begin(), lines.end(), [](const auto& line1, const auto& line2)-> bool {
+        return strcmp(line1.iface, line2.iface) < 0;
+    });
+    expectStatsLineEqual(value1, IFACE_NAME1, UID_ALL, SET_ALL, TAG_NONE, lines[0]);
+    expectStatsLineEqual(value1, IFACE_NAME3, UID_ALL, SET_ALL, TAG_NONE, lines[1]);
+    expectStatsLineEqual(value2, IFACE_NAME2, UID_ALL, SET_ALL, TAG_NONE, lines[2]);
+    ASSERT_EQ(0, strcmp(TRUNCATED_IFACE_NAME, lines[3].iface));
+    expectStatsLineEqual(value2, TRUNCATED_IFACE_NAME, UID_ALL, SET_ALL, TAG_NONE, lines[3]);
+}
+}  // namespace bpf
+}  // namespace android