diff --git a/staticlibs/tests/unit/Android.bp b/staticlibs/tests/unit/Android.bp
index 52c5f82..cb15277 100644
--- a/staticlibs/tests/unit/Android.bp
+++ b/staticlibs/tests/unit/Android.bp
@@ -5,6 +5,7 @@
 android_library {
     name: "NetworkStaticLibTestsLib",
     srcs: ["src/**/*.java","src/**/*.kt"],
+    min_sdk_version: "29",
     jarjar_rules: "jarjar-rules.txt",
     static_libs: [
         "net-utils-framework-common",
@@ -16,6 +17,7 @@
     ],
     visibility: [
         "//frameworks/base/packages/Tethering/tests/integration",
+        "//packages/modules/NetworkStack/tests/integration",
     ]
 }
 
diff --git a/staticlibs/tests/unit/src/com/android/net/module/util/Inet4AddressUtilsTest.java b/staticlibs/tests/unit/src/com/android/net/module/util/Inet4AddressUtilsTest.java
new file mode 100644
index 0000000..5d5ed91
--- /dev/null
+++ b/staticlibs/tests/unit/src/com/android/net/module/util/Inet4AddressUtilsTest.java
@@ -0,0 +1,210 @@
+/*
+ * Copyright (C) 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.
+ */
+
+package com.android.net.module.util;
+
+import static com.android.net.module.util.Inet4AddressUtils.getBroadcastAddress;
+import static com.android.net.module.util.Inet4AddressUtils.getImplicitNetmask;
+import static com.android.net.module.util.Inet4AddressUtils.getPrefixMaskAsInet4Address;
+import static com.android.net.module.util.Inet4AddressUtils.inet4AddressToIntHTH;
+import static com.android.net.module.util.Inet4AddressUtils.inet4AddressToIntHTL;
+import static com.android.net.module.util.Inet4AddressUtils.intToInet4AddressHTH;
+import static com.android.net.module.util.Inet4AddressUtils.intToInet4AddressHTL;
+import static com.android.net.module.util.Inet4AddressUtils.netmaskToPrefixLength;
+import static com.android.net.module.util.Inet4AddressUtils.prefixLengthToV4NetmaskIntHTH;
+import static com.android.net.module.util.Inet4AddressUtils.prefixLengthToV4NetmaskIntHTL;
+
+import static junit.framework.Assert.assertEquals;
+
+import static org.junit.Assert.fail;
+
+import android.net.InetAddresses;
+
+import androidx.test.filters.SmallTest;
+import androidx.test.runner.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.net.Inet4Address;
+
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public class Inet4AddressUtilsTest {
+
+    @Test
+    public void testInet4AddressToIntHTL() {
+        assertEquals(0, inet4AddressToIntHTL(ipv4Address("0.0.0.0")));
+        assertEquals(0x000080ff, inet4AddressToIntHTL(ipv4Address("255.128.0.0")));
+        assertEquals(0x0080ff0a, inet4AddressToIntHTL(ipv4Address("10.255.128.0")));
+        assertEquals(0x00feff0a, inet4AddressToIntHTL(ipv4Address("10.255.254.0")));
+        assertEquals(0xfeffa8c0, inet4AddressToIntHTL(ipv4Address("192.168.255.254")));
+        assertEquals(0xffffa8c0, inet4AddressToIntHTL(ipv4Address("192.168.255.255")));
+    }
+
+    @Test
+    public void testIntToInet4AddressHTL() {
+        assertEquals(ipv4Address("0.0.0.0"), intToInet4AddressHTL(0));
+        assertEquals(ipv4Address("255.128.0.0"), intToInet4AddressHTL(0x000080ff));
+        assertEquals(ipv4Address("10.255.128.0"), intToInet4AddressHTL(0x0080ff0a));
+        assertEquals(ipv4Address("10.255.254.0"), intToInet4AddressHTL(0x00feff0a));
+        assertEquals(ipv4Address("192.168.255.254"), intToInet4AddressHTL(0xfeffa8c0));
+        assertEquals(ipv4Address("192.168.255.255"), intToInet4AddressHTL(0xffffa8c0));
+    }
+
+    @Test
+    public void testInet4AddressToIntHTH() {
+        assertEquals(0, inet4AddressToIntHTH(ipv4Address("0.0.0.0")));
+        assertEquals(0xff800000, inet4AddressToIntHTH(ipv4Address("255.128.0.0")));
+        assertEquals(0x0aff8000, inet4AddressToIntHTH(ipv4Address("10.255.128.0")));
+        assertEquals(0x0afffe00, inet4AddressToIntHTH(ipv4Address("10.255.254.0")));
+        assertEquals(0xc0a8fffe, inet4AddressToIntHTH(ipv4Address("192.168.255.254")));
+        assertEquals(0xc0a8ffff, inet4AddressToIntHTH(ipv4Address("192.168.255.255")));
+    }
+
+    @Test
+    public void testIntToInet4AddressHTH() {
+        assertEquals(ipv4Address("0.0.0.0"), intToInet4AddressHTH(0));
+        assertEquals(ipv4Address("255.128.0.0"), intToInet4AddressHTH(0xff800000));
+        assertEquals(ipv4Address("10.255.128.0"), intToInet4AddressHTH(0x0aff8000));
+        assertEquals(ipv4Address("10.255.254.0"), intToInet4AddressHTH(0x0afffe00));
+        assertEquals(ipv4Address("192.168.255.254"), intToInet4AddressHTH(0xc0a8fffe));
+        assertEquals(ipv4Address("192.168.255.255"), intToInet4AddressHTH(0xc0a8ffff));
+    }
+
+
+    @Test
+    public void testPrefixLengthToV4NetmaskIntHTL() {
+        assertEquals(0, prefixLengthToV4NetmaskIntHTL(0));
+        assertEquals(0x000080ff /* 255.128.0.0 */, prefixLengthToV4NetmaskIntHTL(9));
+        assertEquals(0x0080ffff /* 255.255.128.0 */, prefixLengthToV4NetmaskIntHTL(17));
+        assertEquals(0x00feffff /* 255.255.254.0 */, prefixLengthToV4NetmaskIntHTL(23));
+        assertEquals(0xfeffffff /* 255.255.255.254 */, prefixLengthToV4NetmaskIntHTL(31));
+        assertEquals(0xffffffff /* 255.255.255.255 */, prefixLengthToV4NetmaskIntHTL(32));
+    }
+
+    @Test
+    public void testPrefixLengthToV4NetmaskIntHTH() {
+        assertEquals(0, prefixLengthToV4NetmaskIntHTH(0));
+        assertEquals(0xff800000 /* 255.128.0.0 */, prefixLengthToV4NetmaskIntHTH(9));
+        assertEquals(0xffff8000 /* 255.255.128.0 */, prefixLengthToV4NetmaskIntHTH(17));
+        assertEquals(0xfffffe00 /* 255.255.254.0 */, prefixLengthToV4NetmaskIntHTH(23));
+        assertEquals(0xfffffffe /* 255.255.255.254 */, prefixLengthToV4NetmaskIntHTH(31));
+        assertEquals(0xffffffff /* 255.255.255.255 */, prefixLengthToV4NetmaskIntHTH(32));
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testPrefixLengthToV4NetmaskIntHTH_NegativeLength() {
+        prefixLengthToV4NetmaskIntHTH(-1);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testPrefixLengthToV4NetmaskIntHTH_LengthTooLarge() {
+        prefixLengthToV4NetmaskIntHTH(33);
+    }
+
+    private void checkAddressMasking(String expectedAddr, String addr, int prefixLength) {
+        final int prefix = prefixLengthToV4NetmaskIntHTH(prefixLength);
+        final int addrInt = inet4AddressToIntHTH(ipv4Address(addr));
+        assertEquals(ipv4Address(expectedAddr), intToInet4AddressHTH(prefix & addrInt));
+    }
+
+    @Test
+    public void testPrefixLengthToV4NetmaskIntHTH_MaskAddr() {
+        checkAddressMasking("192.168.0.0", "192.168.128.1", 16);
+        checkAddressMasking("255.240.0.0", "255.255.255.255", 12);
+        checkAddressMasking("255.255.255.255", "255.255.255.255", 32);
+        checkAddressMasking("0.0.0.0", "255.255.255.255", 0);
+    }
+
+    @Test
+    public void testGetImplicitNetmask() {
+        assertEquals(8, getImplicitNetmask(ipv4Address("4.2.2.2")));
+        assertEquals(8, getImplicitNetmask(ipv4Address("10.5.6.7")));
+        assertEquals(16, getImplicitNetmask(ipv4Address("173.194.72.105")));
+        assertEquals(16, getImplicitNetmask(ipv4Address("172.23.68.145")));
+        assertEquals(24, getImplicitNetmask(ipv4Address("192.0.2.1")));
+        assertEquals(24, getImplicitNetmask(ipv4Address("192.168.5.1")));
+        assertEquals(32, getImplicitNetmask(ipv4Address("224.0.0.1")));
+        assertEquals(32, getImplicitNetmask(ipv4Address("255.6.7.8")));
+    }
+
+    private void assertInvalidNetworkMask(Inet4Address addr) {
+        try {
+            netmaskToPrefixLength(addr);
+            fail("Invalid netmask " + addr.getHostAddress() + " did not cause exception");
+        } catch (IllegalArgumentException expected) {
+        }
+    }
+
+    @Test
+    public void testNetmaskToPrefixLength() {
+        assertEquals(0, netmaskToPrefixLength(ipv4Address("0.0.0.0")));
+        assertEquals(9, netmaskToPrefixLength(ipv4Address("255.128.0.0")));
+        assertEquals(17, netmaskToPrefixLength(ipv4Address("255.255.128.0")));
+        assertEquals(23, netmaskToPrefixLength(ipv4Address("255.255.254.0")));
+        assertEquals(31, netmaskToPrefixLength(ipv4Address("255.255.255.254")));
+        assertEquals(32, netmaskToPrefixLength(ipv4Address("255.255.255.255")));
+
+        assertInvalidNetworkMask(ipv4Address("0.0.0.1"));
+        assertInvalidNetworkMask(ipv4Address("255.255.255.253"));
+        assertInvalidNetworkMask(ipv4Address("255.255.0.255"));
+    }
+
+    @Test
+    public void testGetPrefixMaskAsAddress() {
+        assertEquals("255.255.240.0", getPrefixMaskAsInet4Address(20).getHostAddress());
+        assertEquals("255.0.0.0", getPrefixMaskAsInet4Address(8).getHostAddress());
+        assertEquals("0.0.0.0", getPrefixMaskAsInet4Address(0).getHostAddress());
+        assertEquals("255.255.255.255", getPrefixMaskAsInet4Address(32).getHostAddress());
+    }
+
+    @Test
+    public void testGetBroadcastAddress() {
+        assertEquals("192.168.15.255",
+                getBroadcastAddress(ipv4Address("192.168.0.123"), 20).getHostAddress());
+        assertEquals("192.255.255.255",
+                getBroadcastAddress(ipv4Address("192.168.0.123"), 8).getHostAddress());
+        assertEquals("192.168.0.123",
+                getBroadcastAddress(ipv4Address("192.168.0.123"), 32).getHostAddress());
+        assertEquals("255.255.255.255",
+                getBroadcastAddress(ipv4Address("192.168.0.123"), 0).getHostAddress());
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testGetBroadcastAddress_PrefixTooLarge() {
+        getBroadcastAddress(ipv4Address("192.168.0.123"), 33);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testGetBroadcastAddress_NegativePrefix() {
+        getBroadcastAddress(ipv4Address("192.168.0.123"), -1);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testGetPrefixMaskAsAddress_PrefixTooLarge() {
+        getPrefixMaskAsInet4Address(33);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testGetPrefixMaskAsAddress_NegativePrefix() {
+        getPrefixMaskAsInet4Address(-1);
+    }
+
+    private Inet4Address ipv4Address(String addr) {
+        return (Inet4Address) InetAddresses.parseNumericAddress(addr);
+    }
+}