diff --git a/framework/jni/android_net_NetworkUtils.cpp b/framework/jni/android_net_NetworkUtils.cpp
new file mode 100644
index 0000000..c70309f
--- /dev/null
+++ b/framework/jni/android_net_NetworkUtils.cpp
@@ -0,0 +1,302 @@
+/*
+ * Copyright 2020, 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.
+ */
+
+#define LOG_TAG "NetworkUtils"
+
+#include <vector>
+
+#include <android/file_descriptor_jni.h>
+#include <arpa/inet.h>
+#include <linux/filter.h>
+#include <linux/if_arp.h>
+#include <linux/tcp.h>
+#include <net/if.h>
+#include <netinet/ether.h>
+#include <netinet/ip.h>
+#include <netinet/udp.h>
+
+#include <DnsProxydProtocol.h> // NETID_USE_LOCAL_NAMESERVERS
+#include <cutils/properties.h>
+#include <nativehelper/JNIPlatformHelp.h>
+#include <nativehelper/ScopedLocalRef.h>
+#include <utils/Log.h>
+#include <utils/misc.h>
+
+#include "NetdClient.h"
+#include "jni.h"
+
+extern "C" {
+int ifc_enable(const char *ifname);
+int ifc_disable(const char *ifname);
+}
+
+#define NETUTILS_PKG_NAME "android/net/NetworkUtils"
+
+namespace android {
+
+constexpr int MAXPACKETSIZE = 8 * 1024;
+// FrameworkListener limits the size of commands to 4096 bytes.
+constexpr int MAXCMDSIZE = 4096;
+
+static inline jclass FindClassOrDie(JNIEnv* env, const char* class_name) {
+    jclass clazz = env->FindClass(class_name);
+    LOG_ALWAYS_FATAL_IF(clazz == NULL, "Unable to find class %s", class_name);
+    return clazz;
+}
+
+static inline jmethodID GetMethodIDOrDie(JNIEnv* env, jclass clazz, const char* method_name,
+                                         const char* method_signature) {
+    jmethodID res = env->GetMethodID(clazz, method_name, method_signature);
+    LOG_ALWAYS_FATAL_IF(res == NULL, "Unable to find method %s with signature %s", method_name,
+                        method_signature);
+    return res;
+}
+
+template <typename T>
+static inline T MakeGlobalRefOrDie(JNIEnv* env, T in) {
+    jobject res = env->NewGlobalRef(in);
+    LOG_ALWAYS_FATAL_IF(res == NULL, "Unable to create global reference.");
+    return static_cast<T>(res);
+}
+
+static void throwErrnoException(JNIEnv* env, const char* functionName, int error) {
+    ScopedLocalRef<jstring> detailMessage(env, env->NewStringUTF(functionName));
+    if (detailMessage.get() == NULL) {
+        // Not really much we can do here. We're probably dead in the water,
+        // but let's try to stumble on...
+        env->ExceptionClear();
+    }
+    static jclass errnoExceptionClass =
+            MakeGlobalRefOrDie(env, FindClassOrDie(env, "android/system/ErrnoException"));
+
+    static jmethodID errnoExceptionCtor =
+            GetMethodIDOrDie(env, errnoExceptionClass,
+            "<init>", "(Ljava/lang/String;I)V");
+
+    jobject exception = env->NewObject(errnoExceptionClass,
+                                       errnoExceptionCtor,
+                                       detailMessage.get(),
+                                       error);
+    env->Throw(reinterpret_cast<jthrowable>(exception));
+}
+
+static void android_net_utils_attachDropAllBPFFilter(JNIEnv *env, jobject clazz, jobject javaFd)
+{
+    struct sock_filter filter_code[] = {
+        // Reject all.
+        BPF_STMT(BPF_RET | BPF_K, 0)
+    };
+    struct sock_fprog filter = {
+        sizeof(filter_code) / sizeof(filter_code[0]),
+        filter_code,
+    };
+
+    int fd = AFileDescriptor_getFD(env, javaFd);
+    if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter)) != 0) {
+        jniThrowExceptionFmt(env, "java/net/SocketException",
+                "setsockopt(SO_ATTACH_FILTER): %s", strerror(errno));
+    }
+}
+
+static void android_net_utils_detachBPFFilter(JNIEnv *env, jobject clazz, jobject javaFd)
+{
+    int optval_ignored = 0;
+    int fd = AFileDescriptor_getFD(env, javaFd);
+    if (setsockopt(fd, SOL_SOCKET, SO_DETACH_FILTER, &optval_ignored, sizeof(optval_ignored)) !=
+        0) {
+        jniThrowExceptionFmt(env, "java/net/SocketException",
+                "setsockopt(SO_DETACH_FILTER): %s", strerror(errno));
+    }
+}
+
+static jboolean android_net_utils_bindProcessToNetwork(JNIEnv *env, jobject thiz, jint netId)
+{
+    return (jboolean) !setNetworkForProcess(netId);
+}
+
+static jint android_net_utils_getBoundNetworkForProcess(JNIEnv *env, jobject thiz)
+{
+    return getNetworkForProcess();
+}
+
+static jboolean android_net_utils_bindProcessToNetworkForHostResolution(JNIEnv *env, jobject thiz,
+        jint netId)
+{
+    return (jboolean) !setNetworkForResolv(netId);
+}
+
+static jint android_net_utils_bindSocketToNetwork(JNIEnv *env, jobject thiz, jobject javaFd,
+                                                  jint netId) {
+    return setNetworkForSocket(netId, AFileDescriptor_getFD(env, javaFd));
+}
+
+static bool checkLenAndCopy(JNIEnv* env, const jbyteArray& addr, int len, void* dst)
+{
+    if (env->GetArrayLength(addr) != len) {
+        return false;
+    }
+    env->GetByteArrayRegion(addr, 0, len, reinterpret_cast<jbyte*>(dst));
+    return true;
+}
+
+static jobject android_net_utils_resNetworkQuery(JNIEnv *env, jobject thiz, jint netId,
+        jstring dname, jint ns_class, jint ns_type, jint flags) {
+    const jsize javaCharsCount = env->GetStringLength(dname);
+    const jsize byteCountUTF8 = env->GetStringUTFLength(dname);
+
+    // Only allow dname which could be simply formatted to UTF8.
+    // In native layer, res_mkquery would re-format the input char array to packet.
+    std::vector<char> queryname(byteCountUTF8 + 1, 0);
+
+    env->GetStringUTFRegion(dname, 0, javaCharsCount, queryname.data());
+    int fd = resNetworkQuery(netId, queryname.data(), ns_class, ns_type, flags);
+
+    if (fd < 0) {
+        throwErrnoException(env, "resNetworkQuery", -fd);
+        return nullptr;
+    }
+
+    return jniCreateFileDescriptor(env, fd);
+}
+
+static jobject android_net_utils_resNetworkSend(JNIEnv *env, jobject thiz, jint netId,
+        jbyteArray msg, jint msgLen, jint flags) {
+    uint8_t data[MAXCMDSIZE];
+
+    checkLenAndCopy(env, msg, msgLen, data);
+    int fd = resNetworkSend(netId, data, msgLen, flags);
+
+    if (fd < 0) {
+        throwErrnoException(env, "resNetworkSend", -fd);
+        return nullptr;
+    }
+
+    return jniCreateFileDescriptor(env, fd);
+}
+
+static jobject android_net_utils_resNetworkResult(JNIEnv *env, jobject thiz, jobject javaFd) {
+    int fd = AFileDescriptor_getFD(env, javaFd);
+    int rcode;
+    std::vector<uint8_t> buf(MAXPACKETSIZE, 0);
+
+    int res = resNetworkResult(fd, &rcode, buf.data(), MAXPACKETSIZE);
+    jniSetFileDescriptorOfFD(env, javaFd, -1);
+    if (res < 0) {
+        throwErrnoException(env, "resNetworkResult", -res);
+        return nullptr;
+    }
+
+    jbyteArray answer = env->NewByteArray(res);
+    if (answer == nullptr) {
+        throwErrnoException(env, "resNetworkResult", ENOMEM);
+        return nullptr;
+    } else {
+        env->SetByteArrayRegion(answer, 0, res,
+                reinterpret_cast<jbyte*>(buf.data()));
+    }
+
+    jclass class_DnsResponse = env->FindClass("android/net/DnsResolver$DnsResponse");
+    jmethodID ctor = env->GetMethodID(class_DnsResponse, "<init>", "([BI)V");
+
+    return env->NewObject(class_DnsResponse, ctor, answer, rcode);
+}
+
+static void android_net_utils_resNetworkCancel(JNIEnv *env, jobject thiz, jobject javaFd) {
+    int fd = AFileDescriptor_getFD(env, javaFd);
+    resNetworkCancel(fd);
+    jniSetFileDescriptorOfFD(env, javaFd, -1);
+}
+
+static jobject android_net_utils_getDnsNetwork(JNIEnv *env, jobject thiz) {
+    unsigned dnsNetId = 0;
+    if (int res = getNetworkForDns(&dnsNetId) < 0) {
+        throwErrnoException(env, "getDnsNetId", -res);
+        return nullptr;
+    }
+    bool privateDnsBypass = dnsNetId & NETID_USE_LOCAL_NAMESERVERS;
+
+    static jclass class_Network = MakeGlobalRefOrDie(
+            env, FindClassOrDie(env, "android/net/Network"));
+    static jmethodID ctor = env->GetMethodID(class_Network, "<init>", "(IZ)V");
+    return env->NewObject(
+            class_Network, ctor, dnsNetId & ~NETID_USE_LOCAL_NAMESERVERS, privateDnsBypass);
+}
+
+static jobject android_net_utils_getTcpRepairWindow(JNIEnv *env, jobject thiz, jobject javaFd) {
+    if (javaFd == NULL) {
+        jniThrowNullPointerException(env, NULL);
+        return NULL;
+    }
+
+    int fd = AFileDescriptor_getFD(env, javaFd);
+    struct tcp_repair_window trw = {};
+    socklen_t size = sizeof(trw);
+
+    // Obtain the parameters of the TCP repair window.
+    int rc = getsockopt(fd, IPPROTO_TCP, TCP_REPAIR_WINDOW, &trw, &size);
+    if (rc == -1) {
+        throwErrnoException(env, "getsockopt : TCP_REPAIR_WINDOW", errno);
+        return NULL;
+    }
+
+    struct tcp_info tcpinfo = {};
+    socklen_t tcpinfo_size = sizeof(tcp_info);
+
+    // Obtain the window scale from the tcp info structure. This contains a scale factor that
+    // should be applied to the window size.
+    rc = getsockopt(fd, IPPROTO_TCP, TCP_INFO, &tcpinfo, &tcpinfo_size);
+    if (rc == -1) {
+        throwErrnoException(env, "getsockopt : TCP_INFO", errno);
+        return NULL;
+    }
+
+    jclass class_TcpRepairWindow = env->FindClass("android/net/TcpRepairWindow");
+    jmethodID ctor = env->GetMethodID(class_TcpRepairWindow, "<init>", "(IIIIII)V");
+
+    return env->NewObject(class_TcpRepairWindow, ctor, trw.snd_wl1, trw.snd_wnd, trw.max_window,
+            trw.rcv_wnd, trw.rcv_wup, tcpinfo.tcpi_rcv_wscale);
+}
+
+// ----------------------------------------------------------------------------
+
+/*
+ * JNI registration.
+ */
+// clang-format off
+static const JNINativeMethod gNetworkUtilMethods[] = {
+    /* name, signature, funcPtr */
+    { "bindProcessToNetwork", "(I)Z", (void*) android_net_utils_bindProcessToNetwork },
+    { "getBoundNetworkForProcess", "()I", (void*) android_net_utils_getBoundNetworkForProcess },
+    { "bindProcessToNetworkForHostResolution", "(I)Z", (void*) android_net_utils_bindProcessToNetworkForHostResolution },
+    { "bindSocketToNetwork", "(Ljava/io/FileDescriptor;I)I", (void*) android_net_utils_bindSocketToNetwork },
+    { "attachDropAllBPFFilter", "(Ljava/io/FileDescriptor;)V", (void*) android_net_utils_attachDropAllBPFFilter },
+    { "detachBPFFilter", "(Ljava/io/FileDescriptor;)V", (void*) android_net_utils_detachBPFFilter },
+    { "getTcpRepairWindow", "(Ljava/io/FileDescriptor;)Landroid/net/TcpRepairWindow;", (void*) android_net_utils_getTcpRepairWindow },
+    { "resNetworkSend", "(I[BII)Ljava/io/FileDescriptor;", (void*) android_net_utils_resNetworkSend },
+    { "resNetworkQuery", "(ILjava/lang/String;III)Ljava/io/FileDescriptor;", (void*) android_net_utils_resNetworkQuery },
+    { "resNetworkResult", "(Ljava/io/FileDescriptor;)Landroid/net/DnsResolver$DnsResponse;", (void*) android_net_utils_resNetworkResult },
+    { "resNetworkCancel", "(Ljava/io/FileDescriptor;)V", (void*) android_net_utils_resNetworkCancel },
+    { "getDnsNetwork", "()Landroid/net/Network;", (void*) android_net_utils_getDnsNetwork },
+};
+// clang-format on
+
+int register_android_net_NetworkUtils(JNIEnv* env)
+{
+    return jniRegisterNativeMethods(env, NETUTILS_PKG_NAME, gNetworkUtilMethods,
+                                    NELEM(gNetworkUtilMethods));
+}
+
+}; // namespace android
diff --git a/framework/jni/onload.cpp b/framework/jni/onload.cpp
new file mode 100644
index 0000000..435f434
--- /dev/null
+++ b/framework/jni/onload.cpp
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <nativehelper/JNIHelp.h>
+#include <log/log.h>
+
+namespace android {
+
+int register_android_net_NetworkUtils(JNIEnv* env);
+
+extern "C" jint JNI_OnLoad(JavaVM* vm, void*) {
+    JNIEnv *env;
+    if (vm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6) != JNI_OK) {
+        ALOGE("GetEnv failed");
+        return JNI_ERR;
+    }
+
+    if (register_android_net_NetworkUtils(env) < 0) {
+        return JNI_ERR;
+    }
+
+    return JNI_VERSION_1_6;
+}
+
+};
\ No newline at end of file