diff --git a/tests/cts/hostside/app/src/com/android/cts/net/hostside/MyVpnService.java b/tests/cts/hostside/app/src/com/android/cts/net/hostside/MyVpnService.java
index 449454e..fe522a0 100644
--- a/tests/cts/hostside/app/src/com/android/cts/net/hostside/MyVpnService.java
+++ b/tests/cts/hostside/app/src/com/android/cts/net/hostside/MyVpnService.java
@@ -32,6 +32,7 @@
 import com.android.networkstack.apishim.VpnServiceBuilderShimImpl;
 import com.android.networkstack.apishim.common.UnsupportedApiLevelException;
 import com.android.networkstack.apishim.common.VpnServiceBuilderShim;
+import com.android.testutils.PacketReflector;
 
 import java.io.IOException;
 import java.net.InetAddress;
diff --git a/tests/cts/hostside/app/src/com/android/cts/net/hostside/PacketReflector.java b/tests/cts/hostside/app/src/com/android/cts/net/hostside/PacketReflector.java
deleted file mode 100644
index 124c2c3..0000000
--- a/tests/cts/hostside/app/src/com/android/cts/net/hostside/PacketReflector.java
+++ /dev/null
@@ -1,254 +0,0 @@
-/*
- * Copyright (C) 2014 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.cts.net.hostside;
-
-import static android.system.OsConstants.ICMP6_ECHO_REPLY;
-import static android.system.OsConstants.ICMP6_ECHO_REQUEST;
-import static android.system.OsConstants.ICMP_ECHO;
-import static android.system.OsConstants.ICMP_ECHOREPLY;
-
-import android.system.ErrnoException;
-import android.system.Os;
-import android.util.Log;
-
-import java.io.FileDescriptor;
-import java.io.IOException;
-
-public class PacketReflector extends Thread {
-
-    private static int IPV4_HEADER_LENGTH = 20;
-    private static int IPV6_HEADER_LENGTH = 40;
-
-    private static int IPV4_ADDR_OFFSET = 12;
-    private static int IPV6_ADDR_OFFSET = 8;
-    private static int IPV4_ADDR_LENGTH = 4;
-    private static int IPV6_ADDR_LENGTH = 16;
-
-    private static int IPV4_PROTO_OFFSET = 9;
-    private static int IPV6_PROTO_OFFSET = 6;
-
-    private static final byte IPPROTO_ICMP = 1;
-    private static final byte IPPROTO_TCP = 6;
-    private static final byte IPPROTO_UDP = 17;
-    private static final byte IPPROTO_ICMPV6 = 58;
-
-    private static int ICMP_HEADER_LENGTH = 8;
-    private static int TCP_HEADER_LENGTH = 20;
-    private static int UDP_HEADER_LENGTH = 8;
-
-    private static final byte ICMP_ECHO = 8;
-    private static final byte ICMP_ECHOREPLY = 0;
-
-    private static String TAG = "PacketReflector";
-
-    private FileDescriptor mFd;
-    private byte[] mBuf;
-
-    public PacketReflector(FileDescriptor fd, int mtu) {
-        super("PacketReflector");
-        mFd = fd;
-        mBuf = new byte[mtu];
-    }
-
-    private static void swapBytes(byte[] buf, int pos1, int pos2, int len) {
-        for (int i = 0; i < len; i++) {
-            byte b = buf[pos1 + i];
-            buf[pos1 + i] = buf[pos2 + i];
-            buf[pos2 + i] = b;
-        }
-    }
-
-    private static void swapAddresses(byte[] buf, int version) {
-        int addrPos, addrLen;
-        switch(version) {
-            case 4:
-                addrPos = IPV4_ADDR_OFFSET;
-                addrLen = IPV4_ADDR_LENGTH;
-                break;
-            case 6:
-                addrPos = IPV6_ADDR_OFFSET;
-                addrLen = IPV6_ADDR_LENGTH;
-                break;
-            default:
-                throw new IllegalArgumentException();
-        }
-        swapBytes(buf, addrPos, addrPos + addrLen, addrLen);
-    }
-
-    // Reflect TCP packets: swap the source and destination addresses, but don't change the ports.
-    // This is used by the test to "connect to itself" through the VPN.
-    private void processTcpPacket(byte[] buf, int version, int len, int hdrLen) {
-        if (len < hdrLen + TCP_HEADER_LENGTH) {
-            return;
-        }
-
-        // Swap src and dst IP addresses.
-        swapAddresses(buf, version);
-
-        // Send the packet back.
-        writePacket(buf, len);
-    }
-
-    // Echo UDP packets: swap source and destination addresses, and source and destination ports.
-    // This is used by the test to check that the bytes it sends are echoed back.
-    private void processUdpPacket(byte[] buf, int version, int len, int hdrLen) {
-        if (len < hdrLen + UDP_HEADER_LENGTH) {
-            return;
-        }
-
-        // Swap src and dst IP addresses.
-        swapAddresses(buf, version);
-
-        // Swap dst and src ports.
-        int portOffset = hdrLen;
-        swapBytes(buf, portOffset, portOffset + 2, 2);
-
-        // Send the packet back.
-        writePacket(buf, len);
-    }
-
-    private void processIcmpPacket(byte[] buf, int version, int len, int hdrLen) {
-        if (len < hdrLen + ICMP_HEADER_LENGTH) {
-            return;
-        }
-
-        byte type = buf[hdrLen];
-        if (!(version == 4 && type == ICMP_ECHO) &&
-            !(version == 6 && type == (byte) ICMP6_ECHO_REQUEST)) {
-            return;
-        }
-
-        // Save the ping packet we received.
-        byte[] request = buf.clone();
-
-        // Swap src and dst IP addresses, and send the packet back.
-        // This effectively pings the device to see if it replies.
-        swapAddresses(buf, version);
-        writePacket(buf, len);
-
-        // The device should have replied, and buf should now contain a ping response.
-        int received = readPacket(buf);
-        if (received != len) {
-            Log.i(TAG, "Reflecting ping did not result in ping response: " +
-                       "read=" + received + " expected=" + len);
-            return;
-        }
-
-        byte replyType = buf[hdrLen];
-        if ((type == ICMP_ECHO && replyType != ICMP_ECHOREPLY)
-                || (type == (byte) ICMP6_ECHO_REQUEST && replyType != (byte) ICMP6_ECHO_REPLY)) {
-            Log.i(TAG, "Received unexpected ICMP reply: original " + type
-                    + ", reply " + replyType);
-            return;
-        }
-
-        // Compare the response we got with the original packet.
-        // The only thing that should have changed are addresses, type and checksum.
-        // Overwrite them with the received bytes and see if the packet is otherwise identical.
-        request[hdrLen] = buf[hdrLen];          // Type
-        request[hdrLen + 2] = buf[hdrLen + 2];  // Checksum byte 1.
-        request[hdrLen + 3] = buf[hdrLen + 3];  // Checksum byte 2.
-
-        // Since Linux kernel 4.2, net.ipv6.auto_flowlabels is set by default, and therefore
-        // the request and reply may have different IPv6 flow label: ignore that as well.
-        if (version == 6) {
-            request[1] = (byte)(request[1] & 0xf0 | buf[1] & 0x0f);
-            request[2] = buf[2];
-            request[3] = buf[3];
-        }
-
-        for (int i = 0; i < len; i++) {
-            if (buf[i] != request[i]) {
-                Log.i(TAG, "Received non-matching packet when expecting ping response.");
-                return;
-            }
-        }
-
-        // Now swap the addresses again and reflect the packet. This sends a ping reply.
-        swapAddresses(buf, version);
-        writePacket(buf, len);
-    }
-
-    private void writePacket(byte[] buf, int len) {
-        try {
-            Os.write(mFd, buf, 0, len);
-        } catch (ErrnoException|IOException e) {
-            Log.e(TAG, "Error writing packet: " + e.getMessage());
-        }
-    }
-
-    private int readPacket(byte[] buf) {
-        int len;
-        try {
-            len = Os.read(mFd, buf, 0, buf.length);
-        } catch (ErrnoException|IOException e) {
-            Log.e(TAG, "Error reading packet: " + e.getMessage());
-            len = -1;
-        }
-        return len;
-    }
-
-    // Reads one packet from our mFd, and possibly writes the packet back.
-    private void processPacket() {
-        int len = readPacket(mBuf);
-        if (len < 1) {
-            return;
-        }
-
-        int version = mBuf[0] >> 4;
-        int addrPos, protoPos, hdrLen, addrLen;
-        if (version == 4) {
-            hdrLen = IPV4_HEADER_LENGTH;
-            protoPos = IPV4_PROTO_OFFSET;
-            addrPos = IPV4_ADDR_OFFSET;
-            addrLen = IPV4_ADDR_LENGTH;
-        } else if (version == 6) {
-            hdrLen = IPV6_HEADER_LENGTH;
-            protoPos = IPV6_PROTO_OFFSET;
-            addrPos = IPV6_ADDR_OFFSET;
-            addrLen = IPV6_ADDR_LENGTH;
-        } else {
-            return;
-        }
-
-        if (len < hdrLen) {
-            return;
-        }
-
-        byte proto = mBuf[protoPos];
-        switch (proto) {
-            case IPPROTO_ICMP:
-            case IPPROTO_ICMPV6:
-                processIcmpPacket(mBuf, version, len, hdrLen);
-                break;
-            case IPPROTO_TCP:
-                processTcpPacket(mBuf, version, len, hdrLen);
-                break;
-            case IPPROTO_UDP:
-                processUdpPacket(mBuf, version, len, hdrLen);
-                break;
-        }
-    }
-
-    public void run() {
-        Log.i(TAG, "PacketReflector starting fd=" + mFd + " valid=" + mFd.valid());
-        while (!interrupted() && mFd.valid()) {
-            processPacket();
-        }
-        Log.i(TAG, "PacketReflector exiting fd=" + mFd + " valid=" + mFd.valid());
-    }
-}