diff --git a/TEST_MAPPING b/TEST_MAPPING
index ffbd1fc..780ba26 100644
--- a/TEST_MAPPING
+++ b/TEST_MAPPING
@@ -26,6 +26,9 @@
     },
     {
       "name": "traffic_controller_unit_test"
+    },
+    {
+      "name": "libnetworkstats_test"
     }
   ],
   "postsubmit": [
@@ -42,6 +45,9 @@
     {
       "name": "traffic_controller_unit_test",
       "keywords": ["netd-device-kernel-4.9", "netd-device-kernel-4.14"]
+    },
+    {
+      "name": "libnetworkstats_test"
     }
   ],
   "mainline-presubmit": [
@@ -61,6 +67,9 @@
     },
     {
       "name": "traffic_controller_unit_test[CaptivePortalLoginGoogle.apk+NetworkStackGoogle.apk+com.google.android.resolv.apex+com.google.android.tethering.apex]"
+    },
+    {
+      "name": "libnetworkstats_test[CaptivePortalLoginGoogle.apk+NetworkStackGoogle.apk+com.google.android.resolv.apex+com.google.android.tethering.apex]"
     }
   ],
   "mainline-postsubmit": [
diff --git a/bpf_progs/Android.bp b/bpf_progs/Android.bp
index a3ca90c..fa5af49 100644
--- a/bpf_progs/Android.bp
+++ b/bpf_progs/Android.bp
@@ -45,9 +45,8 @@
         "//packages/modules/Connectivity/service/native/libs/libclat",
         "//packages/modules/Connectivity/Tethering",
         "//packages/modules/Connectivity/service/native",
+        "//packages/modules/Connectivity/service-t/native/libs/libnetworkstats",
         "//packages/modules/Connectivity/tests/unit/jni",
-        // TODO: remove system/netd/* when all BPF code is moved out of Netd.
-        "//system/netd/libnetdbpf",
         "//system/netd/server",
         "//system/netd/tests",
     ],
diff --git a/bpf_progs/bpf_shared.h b/bpf_progs/bpf_shared.h
index 8577d9d..f0df97b 100644
--- a/bpf_progs/bpf_shared.h
+++ b/bpf_progs/bpf_shared.h
@@ -20,7 +20,6 @@
 #include <linux/if_ether.h>
 #include <linux/in.h>
 #include <linux/in6.h>
-#include <netdutils/UidConstants.h>
 
 // This header file is shared by eBPF kernel programs (C) and netd (C++) and
 // some of the maps are also accessed directly from Java mainline module code.
diff --git a/bpf_progs/netd.c b/bpf_progs/netd.c
index 72ee431..f0af8b4 100644
--- a/bpf_progs/netd.c
+++ b/bpf_progs/netd.c
@@ -25,6 +25,7 @@
 #include <linux/ipv6.h>
 #include <linux/pkt_cls.h>
 #include <linux/tcp.h>
+#include <netdutils/UidConstants.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include "bpf_net_helpers.h"
diff --git a/service-t/native/libs/libnetworkstats/Android.bp b/service-t/native/libs/libnetworkstats/Android.bp
new file mode 100644
index 0000000..bceeefa
--- /dev/null
+++ b/service-t/native/libs/libnetworkstats/Android.bp
@@ -0,0 +1,71 @@
+//
+// Copyright (C) 2017 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 {
+    default_applicable_licenses: ["Android-Apache-2.0"],
+}
+
+cc_library {
+    name: "libnetworkstats",
+    vendor_available: false,
+    host_supported: false,
+    header_libs: ["bpf_connectivity_headers"],
+    srcs: [
+        "BpfNetworkStats.cpp"
+    ],
+    shared_libs: [
+        "libbase",
+        "liblog",
+    ],
+    export_include_dirs: ["include"],
+    cflags: [
+        "-Wall",
+        "-Werror",
+        "-Wno-unused-parameter",
+        "-Wthread-safety",
+    ],
+    sanitize: {
+        cfi: true,
+    },
+    apex_available: [
+        "//apex_available:platform",
+        "com.android.tethering",
+    ],
+    min_sdk_version: "30",
+}
+
+cc_test {
+    name: "libnetworkstats_test",
+    test_suites: ["general-tests"],
+    require_root: true,  // required by setrlimitForTest()
+    header_libs: ["bpf_connectivity_headers"],
+    srcs: [
+        "BpfNetworkStatsTest.cpp",
+    ],
+    cflags: [
+        "-Wall",
+        "-Werror",
+        "-Wno-unused-parameter",
+        "-Wthread-safety",
+    ],
+    static_libs: ["libgmock"],
+    shared_libs: [
+        "libbase",
+        "liblog",
+        "libnetworkstats",
+        "libutils",
+    ],
+}
diff --git a/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp b/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp
new file mode 100644
index 0000000..2970503
--- /dev/null
+++ b/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp
@@ -0,0 +1,350 @@
+/*
+ * Copyright (C) 2017 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 <inttypes.h>
+#include <net/if.h>
+#include <string.h>
+#include <unordered_set>
+
+#include <utils/Log.h>
+#include <utils/misc.h>
+
+#include "android-base/file.h"
+#include "android-base/strings.h"
+#include "android-base/unique_fd.h"
+#include "bpf/BpfMap.h"
+#include "bpf_shared.h"
+#include "netdbpf/BpfNetworkStats.h"
+
+#ifdef LOG_TAG
+#undef LOG_TAG
+#endif
+
+#define LOG_TAG "BpfNetworkStats"
+
+namespace android {
+namespace bpf {
+
+using base::Result;
+
+// The target map for stats reading should be the inactive map, which is oppsite
+// from the config value.
+static constexpr char const* STATS_MAP_PATH[] = {STATS_MAP_B_PATH, STATS_MAP_A_PATH};
+
+int bpfGetUidStatsInternal(uid_t uid, Stats* stats,
+                           const BpfMap<uint32_t, StatsValue>& appUidStatsMap) {
+    auto statsEntry = appUidStatsMap.readValue(uid);
+    if (statsEntry.ok()) {
+        stats->rxPackets = statsEntry.value().rxPackets;
+        stats->txPackets = statsEntry.value().txPackets;
+        stats->rxBytes = statsEntry.value().rxBytes;
+        stats->txBytes = statsEntry.value().txBytes;
+    }
+    return (statsEntry.ok() || statsEntry.error().code() == ENOENT) ? 0
+                                                                    : -statsEntry.error().code();
+}
+
+int bpfGetUidStats(uid_t uid, Stats* stats) {
+    BpfMapRO<uint32_t, StatsValue> appUidStatsMap(APP_UID_STATS_MAP_PATH);
+
+    if (!appUidStatsMap.isValid()) {
+        int ret = -errno;
+        ALOGE("Opening appUidStatsMap(%s) failed: %s", APP_UID_STATS_MAP_PATH, strerror(errno));
+        return ret;
+    }
+    return bpfGetUidStatsInternal(uid, stats, appUidStatsMap);
+}
+
+int bpfGetIfaceStatsInternal(const char* iface, Stats* stats,
+                             const BpfMap<uint32_t, StatsValue>& ifaceStatsMap,
+                             const BpfMap<uint32_t, IfaceValue>& ifaceNameMap) {
+    int64_t unknownIfaceBytesTotal = 0;
+    stats->tcpRxPackets = -1;
+    stats->tcpTxPackets = -1;
+    const auto processIfaceStats =
+            [iface, stats, &ifaceNameMap, &unknownIfaceBytesTotal](
+                    const uint32_t& key,
+                    const BpfMap<uint32_t, StatsValue>& ifaceStatsMap) -> Result<void> {
+        char ifname[IFNAMSIZ];
+        if (getIfaceNameFromMap(ifaceNameMap, ifaceStatsMap, key, ifname, key,
+                                &unknownIfaceBytesTotal)) {
+            return Result<void>();
+        }
+        if (!iface || !strcmp(iface, ifname)) {
+            Result<StatsValue> statsEntry = ifaceStatsMap.readValue(key);
+            if (!statsEntry.ok()) {
+                return statsEntry.error();
+            }
+            stats->rxPackets += statsEntry.value().rxPackets;
+            stats->txPackets += statsEntry.value().txPackets;
+            stats->rxBytes += statsEntry.value().rxBytes;
+            stats->txBytes += statsEntry.value().txBytes;
+        }
+        return Result<void>();
+    };
+    auto res = ifaceStatsMap.iterate(processIfaceStats);
+    return res.ok() ? 0 : -res.error().code();
+}
+
+int bpfGetIfaceStats(const char* iface, Stats* stats) {
+    BpfMapRO<uint32_t, StatsValue> ifaceStatsMap(IFACE_STATS_MAP_PATH);
+    int ret;
+    if (!ifaceStatsMap.isValid()) {
+        ret = -errno;
+        ALOGE("get ifaceStats map fd failed: %s", strerror(errno));
+        return ret;
+    }
+    BpfMapRO<uint32_t, IfaceValue> ifaceIndexNameMap(IFACE_INDEX_NAME_MAP_PATH);
+    if (!ifaceIndexNameMap.isValid()) {
+        ret = -errno;
+        ALOGE("get ifaceIndexName map fd failed: %s", strerror(errno));
+        return ret;
+    }
+    return bpfGetIfaceStatsInternal(iface, stats, ifaceStatsMap, ifaceIndexNameMap);
+}
+
+stats_line populateStatsEntry(const StatsKey& statsKey, const StatsValue& statsEntry,
+                              const char* ifname) {
+    stats_line newLine;
+    strlcpy(newLine.iface, ifname, sizeof(newLine.iface));
+    newLine.uid = (int32_t)statsKey.uid;
+    newLine.set = (int32_t)statsKey.counterSet;
+    newLine.tag = (int32_t)statsKey.tag;
+    newLine.rxPackets = statsEntry.rxPackets;
+    newLine.txPackets = statsEntry.txPackets;
+    newLine.rxBytes = statsEntry.rxBytes;
+    newLine.txBytes = statsEntry.txBytes;
+    return newLine;
+}
+
+int parseBpfNetworkStatsDetailInternal(std::vector<stats_line>* lines,
+                                       const std::vector<std::string>& limitIfaces, int limitTag,
+                                       int limitUid, const BpfMap<StatsKey, StatsValue>& statsMap,
+                                       const BpfMap<uint32_t, IfaceValue>& ifaceMap) {
+    int64_t unknownIfaceBytesTotal = 0;
+    const auto processDetailUidStats =
+            [lines, &limitIfaces, &limitTag, &limitUid, &unknownIfaceBytesTotal, &ifaceMap](
+                    const StatsKey& key,
+                    const BpfMap<StatsKey, StatsValue>& statsMap) -> Result<void> {
+        char ifname[IFNAMSIZ];
+        if (getIfaceNameFromMap(ifaceMap, statsMap, key.ifaceIndex, ifname, key,
+                                &unknownIfaceBytesTotal)) {
+            return Result<void>();
+        }
+        std::string ifnameStr(ifname);
+        if (limitIfaces.size() > 0 &&
+            std::find(limitIfaces.begin(), limitIfaces.end(), ifnameStr) == limitIfaces.end()) {
+            // Nothing matched; skip this line.
+            return Result<void>();
+        }
+        if (limitTag != TAG_ALL && uint32_t(limitTag) != key.tag) {
+            return Result<void>();
+        }
+        if (limitUid != UID_ALL && uint32_t(limitUid) != key.uid) {
+            return Result<void>();
+        }
+        Result<StatsValue> statsEntry = statsMap.readValue(key);
+        if (!statsEntry.ok()) {
+            return base::ResultError(statsEntry.error().message(), statsEntry.error().code());
+        }
+        lines->push_back(populateStatsEntry(key, statsEntry.value(), ifname));
+        return Result<void>();
+    };
+    Result<void> res = statsMap.iterate(processDetailUidStats);
+    if (!res.ok()) {
+        ALOGE("failed to iterate per uid Stats map for detail traffic stats: %s",
+              strerror(res.error().code()));
+        return -res.error().code();
+    }
+
+    // Since eBPF use hash map to record stats, network stats collected from
+    // eBPF will be out of order. And the performance of findIndexHinted in
+    // NetworkStats will also be impacted.
+    //
+    // Furthermore, since the StatsKey contains iface index, the network stats
+    // reported to framework would create items with the same iface, uid, tag
+    // and set, which causes NetworkStats maps wrong item to subtract.
+    //
+    // Thus, the stats needs to be properly sorted and grouped before reported.
+    groupNetworkStats(lines);
+    return 0;
+}
+
+int parseBpfNetworkStatsDetail(std::vector<stats_line>* lines,
+                               const std::vector<std::string>& limitIfaces, int limitTag,
+                               int limitUid) {
+    BpfMapRO<uint32_t, IfaceValue> ifaceIndexNameMap(IFACE_INDEX_NAME_MAP_PATH);
+    if (!ifaceIndexNameMap.isValid()) {
+        int ret = -errno;
+        ALOGE("get ifaceIndexName map fd failed: %s", strerror(errno));
+        return ret;
+    }
+
+    BpfMapRO<uint32_t, uint8_t> configurationMap(CONFIGURATION_MAP_PATH);
+    if (!configurationMap.isValid()) {
+        int ret = -errno;
+        ALOGE("get configuration map fd failed: %s", strerror(errno));
+        return ret;
+    }
+    auto configuration = configurationMap.readValue(CURRENT_STATS_MAP_CONFIGURATION_KEY);
+    if (!configuration.ok()) {
+        ALOGE("Cannot read the old configuration from map: %s",
+              configuration.error().message().c_str());
+        return -configuration.error().code();
+    }
+    const char* statsMapPath = STATS_MAP_PATH[configuration.value()];
+    BpfMap<StatsKey, StatsValue> statsMap(statsMapPath);
+    if (!statsMap.isValid()) {
+        int ret = -errno;
+        ALOGE("get stats map fd failed: %s, path: %s", strerror(errno), statsMapPath);
+        return ret;
+    }
+
+    // It is safe to read and clear the old map now since the
+    // networkStatsFactory should call netd to swap the map in advance already.
+    int ret = parseBpfNetworkStatsDetailInternal(lines, limitIfaces, limitTag, limitUid, statsMap,
+                                                 ifaceIndexNameMap);
+    if (ret) {
+        ALOGE("parse detail network stats failed: %s", strerror(errno));
+        return ret;
+    }
+
+    Result<void> res = statsMap.clear();
+    if (!res.ok()) {
+        ALOGE("Clean up current stats map failed: %s", strerror(res.error().code()));
+        return -res.error().code();
+    }
+
+    return 0;
+}
+
+int parseBpfNetworkStatsDevInternal(std::vector<stats_line>* lines,
+                                    const BpfMap<uint32_t, StatsValue>& statsMap,
+                                    const BpfMap<uint32_t, IfaceValue>& ifaceMap) {
+    int64_t unknownIfaceBytesTotal = 0;
+    const auto processDetailIfaceStats = [lines, &unknownIfaceBytesTotal, &ifaceMap, &statsMap](
+                                             const uint32_t& key, const StatsValue& value,
+                                             const BpfMap<uint32_t, StatsValue>&) {
+        char ifname[IFNAMSIZ];
+        if (getIfaceNameFromMap(ifaceMap, statsMap, key, ifname, key, &unknownIfaceBytesTotal)) {
+            return Result<void>();
+        }
+        StatsKey fakeKey = {
+                .uid = (uint32_t)UID_ALL,
+                .tag = (uint32_t)TAG_NONE,
+                .counterSet = (uint32_t)SET_ALL,
+        };
+        lines->push_back(populateStatsEntry(fakeKey, value, ifname));
+        return Result<void>();
+    };
+    Result<void> res = statsMap.iterateWithValue(processDetailIfaceStats);
+    if (!res.ok()) {
+        ALOGE("failed to iterate per uid Stats map for detail traffic stats: %s",
+              strerror(res.error().code()));
+        return -res.error().code();
+    }
+
+    groupNetworkStats(lines);
+    return 0;
+}
+
+int parseBpfNetworkStatsDev(std::vector<stats_line>* lines) {
+    int ret = 0;
+    BpfMapRO<uint32_t, IfaceValue> ifaceIndexNameMap(IFACE_INDEX_NAME_MAP_PATH);
+    if (!ifaceIndexNameMap.isValid()) {
+        ret = -errno;
+        ALOGE("get ifaceIndexName map fd failed: %s", strerror(errno));
+        return ret;
+    }
+
+    BpfMapRO<uint32_t, StatsValue> ifaceStatsMap(IFACE_STATS_MAP_PATH);
+    if (!ifaceStatsMap.isValid()) {
+        ret = -errno;
+        ALOGE("get ifaceStats map fd failed: %s", strerror(errno));
+        return ret;
+    }
+    return parseBpfNetworkStatsDevInternal(lines, ifaceStatsMap, ifaceIndexNameMap);
+}
+
+uint64_t combineUidTag(const uid_t uid, const uint32_t tag) {
+    return (uint64_t)uid << 32 | tag;
+}
+
+void groupNetworkStats(std::vector<stats_line>* lines) {
+    if (lines->size() <= 1) return;
+    std::sort(lines->begin(), lines->end());
+
+    // Similar to std::unique(), but aggregates the duplicates rather than discarding them.
+    size_t nextOutput = 0;
+    for (size_t i = 1; i < lines->size(); i++) {
+        if (lines->at(nextOutput) == lines->at(i)) {
+            lines->at(nextOutput) += lines->at(i);
+        } else {
+            nextOutput++;
+            if (nextOutput != i) {
+                lines->at(nextOutput) = lines->at(i);
+            }
+        }
+    }
+
+    if (lines->size() != nextOutput + 1) {
+        lines->resize(nextOutput + 1);
+    }
+}
+
+// True if lhs equals to rhs, only compare iface, uid, tag and set.
+bool operator==(const stats_line& lhs, const stats_line& rhs) {
+    return ((lhs.uid == rhs.uid) && (lhs.tag == rhs.tag) && (lhs.set == rhs.set) &&
+            !strncmp(lhs.iface, rhs.iface, sizeof(lhs.iface)));
+}
+
+// True if lhs is smaller then rhs, only compare iface, uid, tag and set.
+bool operator<(const stats_line& lhs, const stats_line& rhs) {
+    int ret = strncmp(lhs.iface, rhs.iface, sizeof(lhs.iface));
+    if (ret != 0) return ret < 0;
+    if (lhs.uid < rhs.uid) return true;
+    if (lhs.uid > rhs.uid) return false;
+    if (lhs.tag < rhs.tag) return true;
+    if (lhs.tag > rhs.tag) return false;
+    if (lhs.set < rhs.set) return true;
+    if (lhs.set > rhs.set) return false;
+    return false;
+}
+
+stats_line& stats_line::operator=(const stats_line& rhs) {
+    if (this == &rhs) return *this;
+
+    strlcpy(iface, rhs.iface, sizeof(iface));
+    uid = rhs.uid;
+    set = rhs.set;
+    tag = rhs.tag;
+    rxPackets = rhs.rxPackets;
+    txPackets = rhs.txPackets;
+    rxBytes = rhs.rxBytes;
+    txBytes = rhs.txBytes;
+    return *this;
+}
+
+stats_line& stats_line::operator+=(const stats_line& rhs) {
+    rxPackets += rhs.rxPackets;
+    txPackets += rhs.txPackets;
+    rxBytes += rhs.rxBytes;
+    txBytes += rhs.txBytes;
+    return *this;
+}
+
+}  // namespace bpf
+}  // namespace android
diff --git a/service-t/native/libs/libnetworkstats/BpfNetworkStatsTest.cpp b/service-t/native/libs/libnetworkstats/BpfNetworkStatsTest.cpp
new file mode 100644
index 0000000..03e6016
--- /dev/null
+++ b/service-t/native/libs/libnetworkstats/BpfNetworkStatsTest.cpp
@@ -0,0 +1,569 @@
+/*
+ * 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 "bpf/BpfMap.h"
+#include "bpf/BpfUtils.h"
+#include "netdbpf/BpfNetworkStats.h"
+
+using ::testing::Test;
+
+namespace android {
+namespace bpf {
+
+using base::Result;
+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, UidTagValue> mFakeCookieTagMap;
+    BpfMap<uint32_t, StatsValue> mFakeAppUidStatsMap;
+    BpfMap<StatsKey, StatsValue> mFakeStatsMap;
+    BpfMap<uint32_t, IfaceValue> mFakeIfaceIndexNameMap;
+    BpfMap<uint32_t, StatsValue> mFakeIfaceStatsMap;
+
+    void SetUp() {
+        ASSERT_EQ(0, setrlimitForTest());
+
+        mFakeCookieTagMap = BpfMap<uint64_t, UidTagValue>(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE, 0);
+        ASSERT_LE(0, mFakeCookieTagMap.getMap());
+
+        mFakeAppUidStatsMap = BpfMap<uint32_t, StatsValue>(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE, 0);
+        ASSERT_LE(0, mFakeAppUidStatsMap.getMap());
+
+        mFakeStatsMap = BpfMap<StatsKey, StatsValue>(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE, 0);
+        ASSERT_LE(0, mFakeStatsMap.getMap());
+
+        mFakeIfaceIndexNameMap = BpfMap<uint32_t, IfaceValue>(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE, 0);
+        ASSERT_LE(0, mFakeIfaceIndexNameMap.getMap());
+
+        mFakeIfaceStatsMap = BpfMap<uint32_t, StatsValue>(BPF_MAP_TYPE_HASH, 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_RESULT_OK(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_RESULT_OK(map.writeValue(key, value, BPF_ANY));
+    }
+
+    void updateIfaceMap(const char* ifaceName, uint32_t ifaceIndex) {
+        IfaceValue iface;
+        strlcpy(iface.name, ifaceName, IFNAMSIZ);
+        EXPECT_RESULT_OK(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((uint32_t) 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) {
+    for (int i = 0; i < 5; i++) {
+        uint64_t cookie = i + 1;
+        UidTagValue tag = {.uid = TEST_UID1, .tag = TEST_TAG};
+        EXPECT_RESULT_OK(mFakeCookieTagMap.writeValue(cookie, tag, BPF_ANY));
+    }
+    uint64_t curCookie = 0;
+    auto nextCookie = mFakeCookieTagMap.getNextKey(curCookie);
+    EXPECT_RESULT_OK(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_RESULT_OK(nextCookie);
+    EXPECT_RESULT_OK(mFakeCookieTagMap.deleteValue((nextCookie.value())));
+    // Find the entry that is now immediately after headOfMap, then delete that.
+    nextCookie = mFakeCookieTagMap.getNextKey(curCookie);
+    EXPECT_RESULT_OK(nextCookie);
+    EXPECT_RESULT_OK(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.error().code());
+    // Finding the entry after our deleted entry restarts iteration from the beginning of the map.
+    nextCookie = mFakeCookieTagMap.getNextKey(curCookie);
+    EXPECT_RESULT_OK(nextCookie);
+    EXPECT_EQ(headOfMap, nextCookie.value());
+}
+
+TEST_F(BpfNetworkStatsHelperTest, TestBpfIterateMap) {
+    for (int i = 0; i < 5; i++) {
+        uint64_t cookie = i + 1;
+        UidTagValue tag = {.uid = TEST_UID1, .tag = TEST_TAG};
+        EXPECT_RESULT_OK(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, UidTagValue>&) {
+                EXPECT_GE((uint64_t)5, key);
+                totalCount++;
+                totalSum += key;
+                return Result<void>();
+            };
+    EXPECT_RESULT_OK(mFakeCookieTagMap.iterate(iterateWithoutDeletion));
+    EXPECT_EQ(5, totalCount);
+    EXPECT_EQ(1 + 2 + 3 + 4 + 5, totalSum);
+}
+
+TEST_F(BpfNetworkStatsHelperTest, TestUidStatsNoTraffic) {
+    StatsValue value1 = {
+            .rxPackets = 0,
+            .rxBytes = 0,
+            .txPackets = 0,
+            .txBytes = 0,
+    };
+    Stats result1 = {};
+    ASSERT_EQ(0, bpfGetUidStatsInternal(TEST_UID1, &result1, mFakeAppUidStatsMap));
+    expectStatsEqual(value1, result1);
+}
+
+TEST_F(BpfNetworkStatsHelperTest, TestGetUidStatsTotal) {
+    updateIfaceMap(IFACE_NAME1, IFACE_INDEX1);
+    updateIfaceMap(IFACE_NAME2, IFACE_INDEX2);
+    updateIfaceMap(IFACE_NAME3, IFACE_INDEX3);
+    StatsValue value1 = {
+            .rxPackets = TEST_PACKET0,
+            .rxBytes = TEST_BYTES0,
+            .txPackets = TEST_PACKET1,
+            .txBytes = TEST_BYTES1,
+    };
+    StatsValue value2 = {
+            .rxPackets = TEST_PACKET0 * 2,
+            .rxBytes = TEST_BYTES0 * 2,
+            .txPackets = TEST_PACKET1 * 2,
+            .txBytes = TEST_BYTES1 * 2,
+    };
+    ASSERT_RESULT_OK(mFakeAppUidStatsMap.writeValue(TEST_UID1, value1, BPF_ANY));
+    ASSERT_RESULT_OK(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, mFakeStatsMap);
+    populateFakeStats(TEST_UID1, 0, IFACE_INDEX2, TEST_COUNTERSET1, value1, mFakeStatsMap);
+    populateFakeStats(TEST_UID2, 0, IFACE_INDEX3, TEST_COUNTERSET1, value1, mFakeStatsMap);
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TAG_ALL, TEST_UID1,
+                                                    mFakeStatsMap, mFakeIfaceIndexNameMap));
+    ASSERT_EQ((unsigned long)2, lines.size());
+    lines.clear();
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TAG_ALL, TEST_UID2,
+                                                    mFakeStatsMap, mFakeIfaceIndexNameMap));
+    ASSERT_EQ((unsigned long)1, lines.size());
+    expectStatsLineEqual(value1, IFACE_NAME3, TEST_UID2, TEST_COUNTERSET1, 0, lines.front());
+}
+
+TEST_F(BpfNetworkStatsHelperTest, TestGetIfaceStatsInternal) {
+    updateIfaceMap(IFACE_NAME1, IFACE_INDEX1);
+    updateIfaceMap(IFACE_NAME2, IFACE_INDEX2);
+    updateIfaceMap(IFACE_NAME3, IFACE_INDEX3);
+    StatsValue value1 = {
+            .rxPackets = TEST_PACKET0,
+            .rxBytes = TEST_BYTES0,
+            .txPackets = TEST_PACKET1,
+            .txBytes = TEST_BYTES1,
+    };
+    StatsValue value2 = {
+            .rxPackets = TEST_PACKET1,
+            .rxBytes = TEST_BYTES1,
+            .txPackets = TEST_PACKET0,
+            .txBytes = TEST_BYTES0,
+    };
+    uint32_t ifaceStatsKey = IFACE_INDEX1;
+    EXPECT_RESULT_OK(mFakeIfaceStatsMap.writeValue(ifaceStatsKey, value1, BPF_ANY));
+    ifaceStatsKey = IFACE_INDEX2;
+    EXPECT_RESULT_OK(mFakeIfaceStatsMap.writeValue(ifaceStatsKey, value2, BPF_ANY));
+    ifaceStatsKey = IFACE_INDEX3;
+    EXPECT_RESULT_OK(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 = {
+            .rxPackets = TEST_PACKET0 * 2 + TEST_PACKET1,
+            .rxBytes = TEST_BYTES0 * 2 + TEST_BYTES1,
+            .txPackets = TEST_PACKET1 * 2 + TEST_PACKET0,
+            .txBytes = TEST_BYTES1 * 2 + TEST_BYTES0,
+    };
+    expectStatsEqual(totalValue, totalResult);
+}
+
+TEST_F(BpfNetworkStatsHelperTest, TestGetStatsDetail) {
+    updateIfaceMap(IFACE_NAME1, IFACE_INDEX1);
+    updateIfaceMap(IFACE_NAME2, IFACE_INDEX2);
+    StatsValue value1 = {
+            .rxPackets = TEST_PACKET0,
+            .rxBytes = TEST_BYTES0,
+            .txPackets = TEST_PACKET1,
+            .txBytes = TEST_BYTES1,
+    };
+    populateFakeStats(TEST_UID1, TEST_TAG, IFACE_INDEX1, TEST_COUNTERSET0, value1, mFakeStatsMap);
+    populateFakeStats(TEST_UID1, TEST_TAG, IFACE_INDEX2, TEST_COUNTERSET0, value1, mFakeStatsMap);
+    populateFakeStats(TEST_UID1, TEST_TAG + 1, IFACE_INDEX1, TEST_COUNTERSET0, value1,
+                      mFakeStatsMap);
+    populateFakeStats(TEST_UID2, TEST_TAG, IFACE_INDEX1, TEST_COUNTERSET0, value1, mFakeStatsMap);
+    std::vector<stats_line> lines;
+    std::vector<std::string> ifaces;
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TAG_ALL, UID_ALL, mFakeStatsMap,
+                                                    mFakeIfaceIndexNameMap));
+    ASSERT_EQ((unsigned long)4, lines.size());
+    lines.clear();
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TAG_ALL, TEST_UID1,
+                                                    mFakeStatsMap, mFakeIfaceIndexNameMap));
+    ASSERT_EQ((unsigned long)3, lines.size());
+    lines.clear();
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TEST_TAG, TEST_UID1,
+                                                    mFakeStatsMap, 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,
+                                                    mFakeStatsMap, mFakeIfaceIndexNameMap));
+    ASSERT_EQ((unsigned long)1, lines.size());
+    expectStatsLineEqual(value1, IFACE_NAME1, TEST_UID1, TEST_COUNTERSET0, TEST_TAG, lines.front());
+}
+
+TEST_F(BpfNetworkStatsHelperTest, TestGetStatsWithSkippedIface) {
+    updateIfaceMap(IFACE_NAME1, IFACE_INDEX1);
+    updateIfaceMap(IFACE_NAME2, IFACE_INDEX2);
+    StatsValue value1 = {
+            .rxPackets = TEST_PACKET0,
+            .rxBytes = TEST_BYTES0,
+            .txPackets = TEST_PACKET1,
+            .txBytes = TEST_BYTES1,
+    };
+    populateFakeStats(0, 0, 0, OVERFLOW_COUNTERSET, value1, mFakeStatsMap);
+    populateFakeStats(TEST_UID1, 0, IFACE_INDEX1, TEST_COUNTERSET0, value1, mFakeStatsMap);
+    populateFakeStats(TEST_UID1, 0, IFACE_INDEX2, TEST_COUNTERSET0, value1, mFakeStatsMap);
+    populateFakeStats(TEST_UID1, 0, IFACE_INDEX1, TEST_COUNTERSET1, value1, mFakeStatsMap);
+    populateFakeStats(TEST_UID2, 0, IFACE_INDEX1, TEST_COUNTERSET0, value1, mFakeStatsMap);
+    std::vector<stats_line> lines;
+    std::vector<std::string> ifaces;
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TAG_ALL, UID_ALL, mFakeStatsMap,
+                                                    mFakeIfaceIndexNameMap));
+    ASSERT_EQ((unsigned long)4, lines.size());
+    lines.clear();
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TAG_ALL, TEST_UID1,
+                                                    mFakeStatsMap, mFakeIfaceIndexNameMap));
+    ASSERT_EQ((unsigned long)3, lines.size());
+    lines.clear();
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TAG_ALL, TEST_UID2,
+                                                    mFakeStatsMap, 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,
+                                                    mFakeStatsMap, mFakeIfaceIndexNameMap));
+    ASSERT_EQ((unsigned long)2, lines.size());
+}
+
+TEST_F(BpfNetworkStatsHelperTest, TestUnkownIfaceError) {
+    updateIfaceMap(IFACE_NAME1, IFACE_INDEX1);
+    StatsValue value1 = {
+            .rxPackets = TEST_PACKET0,
+            .rxBytes = TEST_BYTES0 * 20,
+            .txPackets = TEST_PACKET1,
+            .txBytes = TEST_BYTES1 * 20,
+    };
+    uint32_t ifaceIndex = UNKNOWN_IFACE;
+    populateFakeStats(TEST_UID1, 0, ifaceIndex, TEST_COUNTERSET0, value1, mFakeStatsMap);
+    populateFakeStats(TEST_UID1, 0, IFACE_INDEX1, TEST_COUNTERSET0, value1, mFakeStatsMap);
+    StatsValue value2 = {
+            .rxPackets = TEST_PACKET0,
+            .rxBytes = TEST_BYTES0 * 40,
+            .txPackets = TEST_PACKET1,
+            .txBytes = TEST_BYTES1 * 40,
+    };
+    populateFakeStats(TEST_UID1, 0, IFACE_INDEX2, TEST_COUNTERSET0, value2, mFakeStatsMap);
+    StatsKey curKey = {
+            .uid = TEST_UID1,
+            .tag = 0,
+            .counterSet = TEST_COUNTERSET0,
+            .ifaceIndex = ifaceIndex,
+    };
+    char ifname[IFNAMSIZ];
+    int64_t unknownIfaceBytesTotal = 0;
+    ASSERT_EQ(-ENODEV, getIfaceNameFromMap(mFakeIfaceIndexNameMap, mFakeStatsMap, ifaceIndex,
+                                           ifname, curKey, &unknownIfaceBytesTotal));
+    ASSERT_EQ(((int64_t)(TEST_BYTES0 * 20 + TEST_BYTES1 * 20)), unknownIfaceBytesTotal);
+    curKey.ifaceIndex = IFACE_INDEX2;
+    ASSERT_EQ(-ENODEV, getIfaceNameFromMap(mFakeIfaceIndexNameMap, mFakeStatsMap, 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, mFakeStatsMap,
+                                                    mFakeIfaceIndexNameMap));
+    ASSERT_EQ((unsigned long)1, lines.size());
+    expectStatsLineEqual(value1, IFACE_NAME1, TEST_UID1, TEST_COUNTERSET0, 0, lines.front());
+}
+
+TEST_F(BpfNetworkStatsHelperTest, TestGetIfaceStatsDetail) {
+    updateIfaceMap(IFACE_NAME1, IFACE_INDEX1);
+    updateIfaceMap(IFACE_NAME2, IFACE_INDEX2);
+    updateIfaceMap(IFACE_NAME3, IFACE_INDEX3);
+    updateIfaceMap(LONG_IFACE_NAME, IFACE_INDEX4);
+    StatsValue value1 = {
+            .rxPackets = TEST_PACKET0,
+            .rxBytes = TEST_BYTES0,
+            .txPackets = TEST_PACKET1,
+            .txBytes = TEST_BYTES1,
+    };
+    StatsValue value2 = {
+            .rxPackets = TEST_PACKET1,
+            .rxBytes = TEST_BYTES1,
+            .txPackets = TEST_PACKET0,
+            .txBytes = TEST_BYTES0,
+    };
+    uint32_t ifaceStatsKey = IFACE_INDEX1;
+    EXPECT_RESULT_OK(mFakeIfaceStatsMap.writeValue(ifaceStatsKey, value1, BPF_ANY));
+    ifaceStatsKey = IFACE_INDEX2;
+    EXPECT_RESULT_OK(mFakeIfaceStatsMap.writeValue(ifaceStatsKey, value2, BPF_ANY));
+    ifaceStatsKey = IFACE_INDEX3;
+    EXPECT_RESULT_OK(mFakeIfaceStatsMap.writeValue(ifaceStatsKey, value1, BPF_ANY));
+    ifaceStatsKey = IFACE_INDEX4;
+    EXPECT_RESULT_OK(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());
+
+    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]);
+}
+
+TEST_F(BpfNetworkStatsHelperTest, TestGetStatsSortedAndGrouped) {
+    // Create iface indexes with duplicate iface name.
+    updateIfaceMap(IFACE_NAME1, IFACE_INDEX1);
+    updateIfaceMap(IFACE_NAME2, IFACE_INDEX2);
+    updateIfaceMap(IFACE_NAME1, IFACE_INDEX3);  // Duplicate!
+
+    StatsValue value1 = {
+            .rxPackets = TEST_PACKET0,
+            .rxBytes = TEST_BYTES0,
+            .txPackets = TEST_PACKET1,
+            .txBytes = TEST_BYTES1,
+    };
+    StatsValue value2 = {
+            .rxPackets = TEST_PACKET1,
+            .rxBytes = TEST_BYTES1,
+            .txPackets = TEST_PACKET0,
+            .txBytes = TEST_BYTES0,
+    };
+    StatsValue value3 = {
+            .rxPackets = TEST_PACKET0 * 2,
+            .rxBytes = TEST_BYTES0 * 2,
+            .txPackets = TEST_PACKET1 * 2,
+            .txBytes = TEST_BYTES1 * 2,
+    };
+
+    std::vector<stats_line> lines;
+    std::vector<std::string> ifaces;
+
+    // Test empty stats.
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TAG_ALL, UID_ALL, mFakeStatsMap,
+                                                    mFakeIfaceIndexNameMap));
+    ASSERT_EQ((size_t) 0, lines.size());
+    lines.clear();
+
+    // Test 1 line stats.
+    populateFakeStats(TEST_UID1, TEST_TAG, IFACE_INDEX1, TEST_COUNTERSET0, value1, mFakeStatsMap);
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TAG_ALL, UID_ALL, mFakeStatsMap,
+                                                    mFakeIfaceIndexNameMap));
+    ASSERT_EQ((size_t) 1, lines.size());
+    expectStatsLineEqual(value1, IFACE_NAME1, TEST_UID1, TEST_COUNTERSET0, TEST_TAG, lines[0]);
+    lines.clear();
+
+    // These items should not be grouped.
+    populateFakeStats(TEST_UID1, TEST_TAG, IFACE_INDEX2, TEST_COUNTERSET0, value2, mFakeStatsMap);
+    populateFakeStats(TEST_UID1, TEST_TAG, IFACE_INDEX3, TEST_COUNTERSET1, value2, mFakeStatsMap);
+    populateFakeStats(TEST_UID1, TEST_TAG + 1, IFACE_INDEX1, TEST_COUNTERSET0, value2,
+                      mFakeStatsMap);
+    populateFakeStats(TEST_UID2, TEST_TAG, IFACE_INDEX1, TEST_COUNTERSET0, value1, mFakeStatsMap);
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TAG_ALL, UID_ALL, mFakeStatsMap,
+                                                    mFakeIfaceIndexNameMap));
+    ASSERT_EQ((size_t) 5, lines.size());
+    lines.clear();
+
+    // These items should be grouped.
+    populateFakeStats(TEST_UID1, TEST_TAG, IFACE_INDEX3, TEST_COUNTERSET0, value1, mFakeStatsMap);
+    populateFakeStats(TEST_UID2, TEST_TAG, IFACE_INDEX3, TEST_COUNTERSET0, value1, mFakeStatsMap);
+
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TAG_ALL, UID_ALL, mFakeStatsMap,
+                                                    mFakeIfaceIndexNameMap));
+    ASSERT_EQ((size_t) 5, lines.size());
+
+    // Verify Sorted & Grouped.
+    expectStatsLineEqual(value3, IFACE_NAME1, TEST_UID1, TEST_COUNTERSET0, TEST_TAG, lines[0]);
+    expectStatsLineEqual(value2, IFACE_NAME1, TEST_UID1, TEST_COUNTERSET1, TEST_TAG, lines[1]);
+    expectStatsLineEqual(value2, IFACE_NAME1, TEST_UID1, TEST_COUNTERSET0, TEST_TAG + 1, lines[2]);
+    expectStatsLineEqual(value3, IFACE_NAME1, TEST_UID2, TEST_COUNTERSET0, TEST_TAG, lines[3]);
+    expectStatsLineEqual(value2, IFACE_NAME2, TEST_UID1, TEST_COUNTERSET0, TEST_TAG, lines[4]);
+    lines.clear();
+
+    // Perform test on IfaceStats.
+    uint32_t ifaceStatsKey = IFACE_INDEX2;
+    EXPECT_RESULT_OK(mFakeIfaceStatsMap.writeValue(ifaceStatsKey, value2, BPF_ANY));
+    ifaceStatsKey = IFACE_INDEX1;
+    EXPECT_RESULT_OK(mFakeIfaceStatsMap.writeValue(ifaceStatsKey, value1, BPF_ANY));
+
+    // This should be grouped.
+    ifaceStatsKey = IFACE_INDEX3;
+    EXPECT_RESULT_OK(mFakeIfaceStatsMap.writeValue(ifaceStatsKey, value1, BPF_ANY));
+
+    ASSERT_EQ(0,
+              parseBpfNetworkStatsDevInternal(&lines, mFakeIfaceStatsMap, mFakeIfaceIndexNameMap));
+    ASSERT_EQ((size_t) 2, lines.size());
+
+    expectStatsLineEqual(value3, IFACE_NAME1, UID_ALL, SET_ALL, TAG_NONE, lines[0]);
+    expectStatsLineEqual(value2, IFACE_NAME2, UID_ALL, SET_ALL, TAG_NONE, lines[1]);
+    lines.clear();
+}
+
+// Test to verify that subtract overflow will not be triggered by the compare function invoked from
+// sorting. See http:/b/119193941.
+TEST_F(BpfNetworkStatsHelperTest, TestGetStatsSortAndOverflow) {
+    updateIfaceMap(IFACE_NAME1, IFACE_INDEX1);
+
+    StatsValue value1 = {
+            .rxPackets = TEST_PACKET0,
+            .rxBytes = TEST_BYTES0,
+            .txPackets = TEST_PACKET1,
+            .txBytes = TEST_BYTES1,
+    };
+
+    // Mutate uid, 0 < TEST_UID1 < INT_MAX < INT_MIN < UINT_MAX.
+    populateFakeStats(0, TEST_TAG, IFACE_INDEX1, TEST_COUNTERSET0, value1, mFakeStatsMap);
+    populateFakeStats(UINT_MAX, TEST_TAG, IFACE_INDEX1, TEST_COUNTERSET0, value1, mFakeStatsMap);
+    populateFakeStats(INT_MIN, TEST_TAG, IFACE_INDEX1, TEST_COUNTERSET0, value1, mFakeStatsMap);
+    populateFakeStats(INT_MAX, TEST_TAG, IFACE_INDEX1, TEST_COUNTERSET0, value1, mFakeStatsMap);
+
+    // Mutate tag, 0 < TEST_TAG < INT_MAX < INT_MIN < UINT_MAX.
+    populateFakeStats(TEST_UID1, INT_MAX, IFACE_INDEX1, TEST_COUNTERSET0, value1, mFakeStatsMap);
+    populateFakeStats(TEST_UID1, INT_MIN, IFACE_INDEX1, TEST_COUNTERSET0, value1, mFakeStatsMap);
+    populateFakeStats(TEST_UID1, 0, IFACE_INDEX1, TEST_COUNTERSET0, value1, mFakeStatsMap);
+    populateFakeStats(TEST_UID1, UINT_MAX, IFACE_INDEX1, TEST_COUNTERSET0, value1, mFakeStatsMap);
+
+    // TODO: Mutate counterSet and enlarge TEST_MAP_SIZE if overflow on counterSet is possible.
+
+    std::vector<stats_line> lines;
+    std::vector<std::string> ifaces;
+    ASSERT_EQ(0, parseBpfNetworkStatsDetailInternal(&lines, ifaces, TAG_ALL, UID_ALL, mFakeStatsMap,
+                                                    mFakeIfaceIndexNameMap));
+    ASSERT_EQ((size_t) 8, lines.size());
+
+    // Uid 0 first
+    expectStatsLineEqual(value1, IFACE_NAME1, 0, TEST_COUNTERSET0, TEST_TAG, lines[0]);
+
+    // Test uid, mutate tag.
+    expectStatsLineEqual(value1, IFACE_NAME1, TEST_UID1, TEST_COUNTERSET0, 0, lines[1]);
+    expectStatsLineEqual(value1, IFACE_NAME1, TEST_UID1, TEST_COUNTERSET0, INT_MAX, lines[2]);
+    expectStatsLineEqual(value1, IFACE_NAME1, TEST_UID1, TEST_COUNTERSET0, INT_MIN, lines[3]);
+    expectStatsLineEqual(value1, IFACE_NAME1, TEST_UID1, TEST_COUNTERSET0, UINT_MAX, lines[4]);
+
+    // Mutate uid.
+    expectStatsLineEqual(value1, IFACE_NAME1, INT_MAX, TEST_COUNTERSET0, TEST_TAG, lines[5]);
+    expectStatsLineEqual(value1, IFACE_NAME1, INT_MIN, TEST_COUNTERSET0, TEST_TAG, lines[6]);
+    expectStatsLineEqual(value1, IFACE_NAME1, UINT_MAX, TEST_COUNTERSET0, TEST_TAG, lines[7]);
+    lines.clear();
+}
+}  // namespace bpf
+}  // namespace android
diff --git a/service-t/native/libs/libnetworkstats/include/netdbpf/BpfNetworkStats.h b/service-t/native/libs/libnetworkstats/include/netdbpf/BpfNetworkStats.h
new file mode 100644
index 0000000..8ab7e25
--- /dev/null
+++ b/service-t/native/libs/libnetworkstats/include/netdbpf/BpfNetworkStats.h
@@ -0,0 +1,126 @@
+/*
+ * 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.
+ */
+
+#ifndef _BPF_NETWORKSTATS_H
+#define _BPF_NETWORKSTATS_H
+
+#include <bpf/BpfMap.h>
+#include "bpf_shared.h"
+
+namespace android {
+namespace bpf {
+
+// TODO: set this to a proper value based on the map size;
+constexpr int TAG_STATS_MAP_SOFT_LIMIT = 3;
+constexpr int UID_ALL = -1;
+constexpr int TAG_ALL = -1;
+constexpr int TAG_NONE = 0;
+constexpr int SET_ALL = -1;
+constexpr int SET_DEFAULT = 0;
+constexpr int SET_FOREGROUND = 1;
+
+// The limit for stats received by a unknown interface;
+constexpr const int64_t MAX_UNKNOWN_IFACE_BYTES = 100 * 1000;
+
+// This is used by
+// frameworks/base/core/jni/com_android_internal_net_NetworkStatsFactory.cpp
+// make sure it is consistent with the JNI code before changing this.
+struct stats_line {
+    char iface[32];
+    uint32_t uid;
+    uint32_t set;
+    uint32_t tag;
+    int64_t rxBytes;
+    int64_t rxPackets;
+    int64_t txBytes;
+    int64_t txPackets;
+
+    stats_line& operator=(const stats_line& rhs);
+    stats_line& operator+=(const stats_line& rhs);
+};
+
+bool operator==(const stats_line& lhs, const stats_line& rhs);
+bool operator<(const stats_line& lhs, const stats_line& rhs);
+
+// For test only
+int bpfGetUidStatsInternal(uid_t uid, Stats* stats,
+                           const BpfMap<uint32_t, StatsValue>& appUidStatsMap);
+// For test only
+int bpfGetIfaceStatsInternal(const char* iface, Stats* stats,
+                             const BpfMap<uint32_t, StatsValue>& ifaceStatsMap,
+                             const BpfMap<uint32_t, IfaceValue>& ifaceNameMap);
+// For test only
+int parseBpfNetworkStatsDetailInternal(std::vector<stats_line>* lines,
+                                       const std::vector<std::string>& limitIfaces, int limitTag,
+                                       int limitUid, const BpfMap<StatsKey, StatsValue>& statsMap,
+                                       const BpfMap<uint32_t, IfaceValue>& ifaceMap);
+// For test only
+int cleanStatsMapInternal(const base::unique_fd& cookieTagMap, const base::unique_fd& tagStatsMap);
+// For test only
+template <class Key>
+int getIfaceNameFromMap(const BpfMap<uint32_t, IfaceValue>& ifaceMap,
+                        const BpfMap<Key, StatsValue>& statsMap, uint32_t ifaceIndex, char* ifname,
+                        const Key& curKey, int64_t* unknownIfaceBytesTotal) {
+    auto iface = ifaceMap.readValue(ifaceIndex);
+    if (!iface.ok()) {
+        maybeLogUnknownIface(ifaceIndex, statsMap, curKey, unknownIfaceBytesTotal);
+        return -ENODEV;
+    }
+    strlcpy(ifname, iface.value().name, sizeof(IfaceValue));
+    return 0;
+}
+
+template <class Key>
+void maybeLogUnknownIface(int ifaceIndex, const BpfMap<Key, StatsValue>& statsMap,
+                          const Key& curKey, int64_t* unknownIfaceBytesTotal) {
+    // Have we already logged an error?
+    if (*unknownIfaceBytesTotal == -1) {
+        return;
+    }
+
+    // Are we undercounting enough data to be worth logging?
+    auto statsEntry = statsMap.readValue(curKey);
+    if (!statsEntry.ok()) {
+        // No data is being undercounted.
+        return;
+    }
+
+    *unknownIfaceBytesTotal += (statsEntry.value().rxBytes + statsEntry.value().txBytes);
+    if (*unknownIfaceBytesTotal >= MAX_UNKNOWN_IFACE_BYTES) {
+        ALOGE("Unknown name for ifindex %d with more than %" PRId64 " bytes of traffic", ifaceIndex,
+              *unknownIfaceBytesTotal);
+        *unknownIfaceBytesTotal = -1;
+    }
+}
+
+// For test only
+int parseBpfNetworkStatsDevInternal(std::vector<stats_line>* lines,
+                                    const BpfMap<uint32_t, StatsValue>& statsMap,
+                                    const BpfMap<uint32_t, IfaceValue>& ifaceMap);
+
+int bpfGetUidStats(uid_t uid, Stats* stats);
+int bpfGetIfaceStats(const char* iface, Stats* stats);
+int parseBpfNetworkStatsDetail(std::vector<stats_line>* lines,
+                               const std::vector<std::string>& limitIfaces, int limitTag,
+                               int limitUid);
+
+int parseBpfNetworkStatsDev(std::vector<stats_line>* lines);
+void groupNetworkStats(std::vector<stats_line>* lines);
+int cleanStatsMap();
+}  // namespace bpf
+}  // namespace android
+
+#endif  // _BPF_NETWORKSTATS_H
diff --git a/service/native/TrafficController.cpp b/service/native/TrafficController.cpp
index cac545d..97fcc43 100644
--- a/service/native/TrafficController.cpp
+++ b/service/native/TrafficController.cpp
@@ -40,6 +40,7 @@
 #include <android-base/unique_fd.h>
 #include <netdutils/StatusOr.h>
 #include <netdutils/Syscalls.h>
+#include <netdutils/UidConstants.h>
 #include <netdutils/Utils.h>
 #include <private/android_filesystem_config.h>
 
diff --git a/tests/unit/Android.bp b/tests/unit/Android.bp
index 0bef0e2..2b698fd 100644
--- a/tests/unit/Android.bp
+++ b/tests/unit/Android.bp
@@ -38,8 +38,8 @@
         "liblog",
         "liblzma",
         "libnativehelper",
-        "libnetdbpf",
         "libnetdutils",
+        "libnetworkstats",
         "libnetworkstatsfactorytestjni",
         "libpackagelistparser",
         "libpcre2",
diff --git a/tests/unit/jni/Android.bp b/tests/unit/jni/Android.bp
index fe971e7..0f71c13 100644
--- a/tests/unit/jni/Android.bp
+++ b/tests/unit/jni/Android.bp
@@ -24,7 +24,7 @@
         "libbpf_android",
         "liblog",
         "libnativehelper",
-        "libnetdbpf",
         "libnetdutils",
+        "libnetworkstats",
     ],
 }