diff --git a/service/src/com/android/server/BpfNetMaps.java b/service/src/com/android/server/BpfNetMaps.java
index 2796dbe..cb1f38a 100644
--- a/service/src/com/android/server/BpfNetMaps.java
+++ b/service/src/com/android/server/BpfNetMaps.java
@@ -54,6 +54,7 @@
 import com.android.net.module.util.DeviceConfigUtils;
 import com.android.net.module.util.IBpfMap;
 import com.android.net.module.util.Struct;
+import com.android.net.module.util.Struct.S32;
 import com.android.net.module.util.Struct.U32;
 import com.android.net.module.util.Struct.U8;
 import com.android.net.module.util.bpf.CookieTagMapKey;
@@ -113,8 +114,8 @@
 
     private static IBpfMap<U32, U32> sConfigurationMap = null;
     // BpfMap for UID_OWNER_MAP_PATH. This map is not accessed by others.
-    private static IBpfMap<U32, UidOwnerValue> sUidOwnerMap = null;
-    private static IBpfMap<U32, U8> sUidPermissionMap = null;
+    private static IBpfMap<S32, UidOwnerValue> sUidOwnerMap = null;
+    private static IBpfMap<S32, U8> sUidPermissionMap = null;
     private static IBpfMap<CookieTagMapKey, CookieTagMapValue> sCookieTagMap = null;
 
     // LINT.IfChange(match_type)
@@ -153,7 +154,7 @@
      * Set uidOwnerMap for test.
      */
     @VisibleForTesting
-    public static void setUidOwnerMapForTest(IBpfMap<U32, UidOwnerValue> uidOwnerMap) {
+    public static void setUidOwnerMapForTest(IBpfMap<S32, UidOwnerValue> uidOwnerMap) {
         sUidOwnerMap = uidOwnerMap;
     }
 
@@ -161,7 +162,7 @@
      * Set uidPermissionMap for test.
      */
     @VisibleForTesting
-    public static void setUidPermissionMapForTest(IBpfMap<U32, U8> uidPermissionMap) {
+    public static void setUidPermissionMapForTest(IBpfMap<S32, U8> uidPermissionMap) {
         sUidPermissionMap = uidPermissionMap;
     }
 
@@ -183,19 +184,19 @@
         }
     }
 
-    private static IBpfMap<U32, UidOwnerValue> getUidOwnerMap() {
+    private static IBpfMap<S32, UidOwnerValue> getUidOwnerMap() {
         try {
             return new BpfMap<>(
-                    UID_OWNER_MAP_PATH, BpfMap.BPF_F_RDWR, U32.class, UidOwnerValue.class);
+                    UID_OWNER_MAP_PATH, BpfMap.BPF_F_RDWR, S32.class, UidOwnerValue.class);
         } catch (ErrnoException e) {
             throw new IllegalStateException("Cannot open uid owner map", e);
         }
     }
 
-    private static IBpfMap<U32, U8> getUidPermissionMap() {
+    private static IBpfMap<S32, U8> getUidPermissionMap() {
         try {
             return new BpfMap<>(
-                    UID_PERMISSION_MAP_PATH, BpfMap.BPF_F_RDWR, U32.class, U8.class);
+                    UID_PERMISSION_MAP_PATH, BpfMap.BPF_F_RDWR, S32.class, U8.class);
         } catch (ErrnoException e) {
             throw new IllegalStateException("Cannot open uid permission map", e);
         }
@@ -389,7 +390,7 @@
     private void removeRule(final int uid, final long match, final String caller) {
         try {
             synchronized (sUidOwnerMap) {
-                final UidOwnerValue oldMatch = sUidOwnerMap.getValue(new U32(uid));
+                final UidOwnerValue oldMatch = sUidOwnerMap.getValue(new S32(uid));
 
                 if (oldMatch == null) {
                     throw new ServiceSpecificException(ENOENT,
@@ -402,9 +403,9 @@
                 );
 
                 if (newMatch.rule == 0) {
-                    sUidOwnerMap.deleteEntry(new U32(uid));
+                    sUidOwnerMap.deleteEntry(new S32(uid));
                 } else {
-                    sUidOwnerMap.updateEntry(new U32(uid), newMatch);
+                    sUidOwnerMap.updateEntry(new S32(uid), newMatch);
                 }
             }
         } catch (ErrnoException e) {
@@ -421,7 +422,7 @@
 
         try {
             synchronized (sUidOwnerMap) {
-                final UidOwnerValue oldMatch = sUidOwnerMap.getValue(new U32(uid));
+                final UidOwnerValue oldMatch = sUidOwnerMap.getValue(new S32(uid));
 
                 final UidOwnerValue newMatch;
                 if (oldMatch != null) {
@@ -435,7 +436,7 @@
                             match
                     );
                 }
-                sUidOwnerMap.updateEntry(new U32(uid), newMatch);
+                sUidOwnerMap.updateEntry(new S32(uid), newMatch);
             }
         } catch (ErrnoException e) {
             throw new ServiceSpecificException(e.errno,
@@ -855,7 +856,7 @@
             if (permissions == PERMISSION_UNINSTALLED || permissions == PERMISSION_INTERNET) {
                 for (final int uid : uids) {
                     try {
-                        sUidPermissionMap.deleteEntry(new U32(uid));
+                        sUidPermissionMap.deleteEntry(new S32(uid));
                     } catch (ErrnoException e) {
                         Log.e(TAG, "Failed to remove uid " + uid + " from permission map: " + e);
                     }
@@ -865,7 +866,7 @@
 
             for (final int uid : uids) {
                 try {
-                    sUidPermissionMap.updateEntry(new U32(uid), new U8((short) permissions));
+                    sUidPermissionMap.updateEntry(new S32(uid), new U8((short) permissions));
                 } catch (ErrnoException e) {
                     Log.e(TAG, "Failed to set permission "
                             + permissions + " to uid " + uid + ": " + e);
diff --git a/tests/unit/java/com/android/server/BpfNetMapsTest.java b/tests/unit/java/com/android/server/BpfNetMapsTest.java
index 8450c2b..38d2cd2 100644
--- a/tests/unit/java/com/android/server/BpfNetMapsTest.java
+++ b/tests/unit/java/com/android/server/BpfNetMapsTest.java
@@ -66,6 +66,7 @@
 
 import com.android.modules.utils.build.SdkLevel;
 import com.android.net.module.util.IBpfMap;
+import com.android.net.module.util.Struct.S32;
 import com.android.net.module.util.Struct.U32;
 import com.android.net.module.util.Struct.U8;
 import com.android.net.module.util.bpf.CookieTagMapKey;
@@ -124,9 +125,9 @@
     @Mock BpfNetMaps.Dependencies mDeps;
     @Mock Context mContext;
     private final IBpfMap<U32, U32> mConfigurationMap = new TestBpfMap<>(U32.class, U32.class);
-    private final IBpfMap<U32, UidOwnerValue> mUidOwnerMap =
-            new TestBpfMap<>(U32.class, UidOwnerValue.class);
-    private final IBpfMap<U32, U8> mUidPermissionMap = new TestBpfMap<>(U32.class, U8.class);
+    private final IBpfMap<S32, UidOwnerValue> mUidOwnerMap =
+            new TestBpfMap<>(S32.class, UidOwnerValue.class);
+    private final IBpfMap<S32, U8> mUidPermissionMap = new TestBpfMap<>(S32.class, U8.class);
     private final IBpfMap<CookieTagMapKey, CookieTagMapValue> mCookieTagMap =
             spy(new TestBpfMap<>(CookieTagMapKey.class, CookieTagMapValue.class));
 
@@ -292,9 +293,9 @@
                 () -> mBpfNetMaps.setChildChain(FIREWALL_CHAIN_DOZABLE, true /* enable */));
     }
 
-    private void checkUidOwnerValue(final long uid, final int expectedIif,
+    private void checkUidOwnerValue(final int uid, final int expectedIif,
             final long expectedMatch) throws Exception {
-        final UidOwnerValue config = mUidOwnerMap.getValue(new U32(uid));
+        final UidOwnerValue config = mUidOwnerMap.getValue(new S32(uid));
         if (expectedMatch == 0) {
             assertNull(config);
         } else {
@@ -304,7 +305,7 @@
     }
 
     private void doTestRemoveNaughtyApp(final int iif, final long match) throws Exception {
-        mUidOwnerMap.updateEntry(new U32(TEST_UID), new UidOwnerValue(iif, match));
+        mUidOwnerMap.updateEntry(new S32(TEST_UID), new UidOwnerValue(iif, match));
 
         mBpfNetMaps.removeNaughtyApp(TEST_UID);
 
@@ -343,7 +344,7 @@
 
     private void doTestAddNaughtyApp(final int iif, final long match) throws Exception {
         if (match != NO_MATCH) {
-            mUidOwnerMap.updateEntry(new U32(TEST_UID), new UidOwnerValue(iif, match));
+            mUidOwnerMap.updateEntry(new S32(TEST_UID), new UidOwnerValue(iif, match));
         }
 
         mBpfNetMaps.addNaughtyApp(TEST_UID);
@@ -374,7 +375,7 @@
     }
 
     private void doTestRemoveNiceApp(final int iif, final long match) throws Exception {
-        mUidOwnerMap.updateEntry(new U32(TEST_UID), new UidOwnerValue(iif, match));
+        mUidOwnerMap.updateEntry(new S32(TEST_UID), new UidOwnerValue(iif, match));
 
         mBpfNetMaps.removeNiceApp(TEST_UID);
 
@@ -413,7 +414,7 @@
 
     private void doTestAddNiceApp(final int iif, final long match) throws Exception {
         if (match != NO_MATCH) {
-            mUidOwnerMap.updateEntry(new U32(TEST_UID), new UidOwnerValue(iif, match));
+            mUidOwnerMap.updateEntry(new S32(TEST_UID), new UidOwnerValue(iif, match));
         }
 
         mBpfNetMaps.addNiceApp(TEST_UID);
@@ -446,7 +447,7 @@
     private void doTestUpdateUidLockdownRule(final int iif, final long match, final boolean add)
             throws Exception {
         if (match != NO_MATCH) {
-            mUidOwnerMap.updateEntry(new U32(TEST_UID), new UidOwnerValue(iif, match));
+            mUidOwnerMap.updateEntry(new S32(TEST_UID), new UidOwnerValue(iif, match));
         }
 
         mBpfNetMaps.updateUidLockdownRule(TEST_UID, add);
@@ -516,8 +517,8 @@
         final int uid1 = TEST_UIDS[1];
         final long match0 = DOZABLE_MATCH;
         final long match1 = DOZABLE_MATCH | POWERSAVE_MATCH | RESTRICTED_MATCH;
-        mUidOwnerMap.updateEntry(new U32(uid0), new UidOwnerValue(NO_IIF, match0));
-        mUidOwnerMap.updateEntry(new U32(uid1), new UidOwnerValue(NO_IIF, match1));
+        mUidOwnerMap.updateEntry(new S32(uid0), new UidOwnerValue(NO_IIF, match0));
+        mUidOwnerMap.updateEntry(new S32(uid1), new UidOwnerValue(NO_IIF, match1));
 
         mBpfNetMaps.addUidInterfaceRules(TEST_IF_NAME, TEST_UIDS);
 
@@ -532,8 +533,8 @@
         final int uid1 = TEST_UIDS[1];
         final long match0 = IIF_MATCH;
         final long match1 = IIF_MATCH | DOZABLE_MATCH | POWERSAVE_MATCH | RESTRICTED_MATCH;
-        mUidOwnerMap.updateEntry(new U32(uid0), new UidOwnerValue(TEST_IF_INDEX + 1, match0));
-        mUidOwnerMap.updateEntry(new U32(uid1), new UidOwnerValue(NULL_IIF, match1));
+        mUidOwnerMap.updateEntry(new S32(uid0), new UidOwnerValue(TEST_IF_INDEX + 1, match0));
+        mUidOwnerMap.updateEntry(new S32(uid1), new UidOwnerValue(NULL_IIF, match1));
 
         mBpfNetMaps.addUidInterfaceRules(TEST_IF_NAME, TEST_UIDS);
 
@@ -556,8 +557,8 @@
         final int uid1 = TEST_UIDS[1];
         final long match0 = IIF_MATCH;
         final long match1 = IIF_MATCH | DOZABLE_MATCH | POWERSAVE_MATCH | RESTRICTED_MATCH;
-        mUidOwnerMap.updateEntry(new U32(uid0), new UidOwnerValue(TEST_IF_INDEX, match0));
-        mUidOwnerMap.updateEntry(new U32(uid1), new UidOwnerValue(NULL_IIF, match1));
+        mUidOwnerMap.updateEntry(new S32(uid0), new UidOwnerValue(TEST_IF_INDEX, match0));
+        mUidOwnerMap.updateEntry(new S32(uid1), new UidOwnerValue(NULL_IIF, match1));
 
         mBpfNetMaps.addUidInterfaceRules(null /* ifName */, TEST_UIDS);
 
@@ -569,8 +570,8 @@
             final int iif1, final long match1) throws Exception {
         final int uid0 = TEST_UIDS[0];
         final int uid1 = TEST_UIDS[1];
-        mUidOwnerMap.updateEntry(new U32(uid0), new UidOwnerValue(iif0, match0));
-        mUidOwnerMap.updateEntry(new U32(uid1), new UidOwnerValue(iif1, match1));
+        mUidOwnerMap.updateEntry(new S32(uid0), new UidOwnerValue(iif0, match0));
+        mUidOwnerMap.updateEntry(new S32(uid1), new UidOwnerValue(iif1, match1));
 
         mBpfNetMaps.removeUidInterfaceRules(TEST_UIDS);
 
@@ -593,7 +594,7 @@
     }
 
     private void doTestSetUidRule(final List<Integer> testChains) throws Exception {
-        mUidOwnerMap.updateEntry(new U32(TEST_UID), new UidOwnerValue(TEST_IF_INDEX, IIF_MATCH));
+        mUidOwnerMap.updateEntry(new S32(TEST_UID), new UidOwnerValue(TEST_IF_INDEX, IIF_MATCH));
 
         for (final int chain: testChains) {
             final int ruleToAddMatch = mBpfNetMaps.isFirewallAllowList(chain)
@@ -697,8 +698,8 @@
         final int uid1 = TEST_UIDS[1];
         final long match0 = POWERSAVE_MATCH;
         final long match1 = POWERSAVE_MATCH | RESTRICTED_MATCH;
-        mUidOwnerMap.updateEntry(new U32(uid0), new UidOwnerValue(NO_IIF, match0));
-        mUidOwnerMap.updateEntry(new U32(uid1), new UidOwnerValue(NO_IIF, match1));
+        mUidOwnerMap.updateEntry(new S32(uid0), new UidOwnerValue(NO_IIF, match0));
+        mUidOwnerMap.updateEntry(new S32(uid1), new UidOwnerValue(NO_IIF, match1));
 
         mBpfNetMaps.replaceUidChain(FIREWALL_CHAIN_DOZABLE, new int[]{uid1});
 
@@ -713,8 +714,8 @@
         final int uid1 = TEST_UIDS[1];
         final long match0 = IIF_MATCH;
         final long match1 = IIF_MATCH | POWERSAVE_MATCH | RESTRICTED_MATCH;
-        mUidOwnerMap.updateEntry(new U32(uid0), new UidOwnerValue(TEST_IF_INDEX, match0));
-        mUidOwnerMap.updateEntry(new U32(uid1), new UidOwnerValue(NULL_IIF, match1));
+        mUidOwnerMap.updateEntry(new S32(uid0), new UidOwnerValue(TEST_IF_INDEX, match0));
+        mUidOwnerMap.updateEntry(new S32(uid1), new UidOwnerValue(NULL_IIF, match1));
 
         mBpfNetMaps.replaceUidChain(FIREWALL_CHAIN_DOZABLE, TEST_UIDS);
 
@@ -729,8 +730,8 @@
         final int uid1 = TEST_UIDS[1];
         final long match0 = IIF_MATCH | DOZABLE_MATCH;
         final long match1 = IIF_MATCH | POWERSAVE_MATCH | RESTRICTED_MATCH;
-        mUidOwnerMap.updateEntry(new U32(uid0), new UidOwnerValue(TEST_IF_INDEX, match0));
-        mUidOwnerMap.updateEntry(new U32(uid1), new UidOwnerValue(NULL_IIF, match1));
+        mUidOwnerMap.updateEntry(new S32(uid0), new UidOwnerValue(TEST_IF_INDEX, match0));
+        mUidOwnerMap.updateEntry(new S32(uid1), new UidOwnerValue(NULL_IIF, match1));
 
         mBpfNetMaps.replaceUidChain(FIREWALL_CHAIN_DOZABLE, new int[]{uid1});
 
@@ -768,8 +769,8 @@
 
         final int uid0 = TEST_UIDS[0];
         final int uid1 = TEST_UIDS[1];
-        assertEquals(PERMISSION_UPDATE_DEVICE_STATS, mUidPermissionMap.getValue(new U32(uid0)).val);
-        assertEquals(PERMISSION_UPDATE_DEVICE_STATS, mUidPermissionMap.getValue(new U32(uid1)).val);
+        assertEquals(PERMISSION_UPDATE_DEVICE_STATS, mUidPermissionMap.getValue(new S32(uid0)).val);
+        assertEquals(PERMISSION_UPDATE_DEVICE_STATS, mUidPermissionMap.getValue(new S32(uid1)).val);
     }
 
     @Test
@@ -780,8 +781,8 @@
 
         final int uid0 = TEST_UIDS[0];
         final int uid1 = TEST_UIDS[1];
-        assertEquals(permission, mUidPermissionMap.getValue(new U32(uid0)).val);
-        assertEquals(permission, mUidPermissionMap.getValue(new U32(uid1)).val);
+        assertEquals(permission, mUidPermissionMap.getValue(new S32(uid0)).val);
+        assertEquals(permission, mUidPermissionMap.getValue(new S32(uid1)).val);
     }
 
     @Test
@@ -792,8 +793,8 @@
         mBpfNetMaps.setNetPermForUids(PERMISSION_INTERNET, TEST_UIDS);
         mBpfNetMaps.setNetPermForUids(PERMISSION_NONE, new int[]{uid0});
 
-        assertEquals(PERMISSION_NONE, mUidPermissionMap.getValue(new U32(uid0)).val);
-        assertNull(mUidPermissionMap.getValue(new U32(uid1)));
+        assertEquals(PERMISSION_NONE, mUidPermissionMap.getValue(new S32(uid0)).val);
+        assertNull(mUidPermissionMap.getValue(new S32(uid1)));
     }
 
     @Test
@@ -804,8 +805,8 @@
         mBpfNetMaps.setNetPermForUids(PERMISSION_UPDATE_DEVICE_STATS, TEST_UIDS);
         mBpfNetMaps.setNetPermForUids(PERMISSION_NONE, new int[]{uid0});
 
-        assertEquals(PERMISSION_NONE, mUidPermissionMap.getValue(new U32(uid0)).val);
-        assertEquals(PERMISSION_UPDATE_DEVICE_STATS, mUidPermissionMap.getValue(new U32(uid1)).val);
+        assertEquals(PERMISSION_NONE, mUidPermissionMap.getValue(new S32(uid0)).val);
+        assertEquals(PERMISSION_UPDATE_DEVICE_STATS, mUidPermissionMap.getValue(new S32(uid1)).val);
     }
 
     @Test
@@ -817,8 +818,8 @@
         mBpfNetMaps.setNetPermForUids(permission, TEST_UIDS);
         mBpfNetMaps.setNetPermForUids(PERMISSION_NONE, new int[]{uid0});
 
-        assertEquals(PERMISSION_NONE, mUidPermissionMap.getValue(new U32(uid0)).val);
-        assertEquals(permission, mUidPermissionMap.getValue(new U32(uid1)).val);
+        assertEquals(PERMISSION_NONE, mUidPermissionMap.getValue(new S32(uid0)).val);
+        assertEquals(permission, mUidPermissionMap.getValue(new S32(uid1)).val);
     }
 
     @Test
@@ -830,8 +831,8 @@
         mBpfNetMaps.setNetPermForUids(permission, TEST_UIDS);
         mBpfNetMaps.setNetPermForUids(PERMISSION_UNINSTALLED, new int[]{uid0});
 
-        assertNull(mUidPermissionMap.getValue(new U32(uid0)));
-        assertEquals(permission, mUidPermissionMap.getValue(new U32(uid1)).val);
+        assertNull(mUidPermissionMap.getValue(new S32(uid0)));
+        assertEquals(permission, mUidPermissionMap.getValue(new S32(uid1)).val);
     }
 
     @Test
@@ -842,28 +843,28 @@
         final int permission = PERMISSION_INTERNET | PERMISSION_UPDATE_DEVICE_STATS;
 
         mBpfNetMaps.setNetPermForUids(permission, TEST_UIDS);
-        assertEquals(permission, mUidPermissionMap.getValue(new U32(uid0)).val);
-        assertEquals(permission, mUidPermissionMap.getValue(new U32(uid1)).val);
+        assertEquals(permission, mUidPermissionMap.getValue(new S32(uid0)).val);
+        assertEquals(permission, mUidPermissionMap.getValue(new S32(uid1)).val);
 
         mBpfNetMaps.setNetPermForUids(permission, TEST_UIDS);
-        assertEquals(permission, mUidPermissionMap.getValue(new U32(uid0)).val);
-        assertEquals(permission, mUidPermissionMap.getValue(new U32(uid1)).val);
+        assertEquals(permission, mUidPermissionMap.getValue(new S32(uid0)).val);
+        assertEquals(permission, mUidPermissionMap.getValue(new S32(uid1)).val);
 
         mBpfNetMaps.setNetPermForUids(PERMISSION_NONE, TEST_UIDS);
-        assertEquals(PERMISSION_NONE, mUidPermissionMap.getValue(new U32(uid0)).val);
-        assertEquals(PERMISSION_NONE, mUidPermissionMap.getValue(new U32(uid1)).val);
+        assertEquals(PERMISSION_NONE, mUidPermissionMap.getValue(new S32(uid0)).val);
+        assertEquals(PERMISSION_NONE, mUidPermissionMap.getValue(new S32(uid1)).val);
 
         mBpfNetMaps.setNetPermForUids(PERMISSION_NONE, TEST_UIDS);
-        assertEquals(PERMISSION_NONE, mUidPermissionMap.getValue(new U32(uid0)).val);
-        assertEquals(PERMISSION_NONE, mUidPermissionMap.getValue(new U32(uid1)).val);
+        assertEquals(PERMISSION_NONE, mUidPermissionMap.getValue(new S32(uid0)).val);
+        assertEquals(PERMISSION_NONE, mUidPermissionMap.getValue(new S32(uid1)).val);
 
         mBpfNetMaps.setNetPermForUids(PERMISSION_UNINSTALLED, TEST_UIDS);
-        assertNull(mUidPermissionMap.getValue(new U32(uid0)));
-        assertNull(mUidPermissionMap.getValue(new U32(uid1)));
+        assertNull(mUidPermissionMap.getValue(new S32(uid0)));
+        assertNull(mUidPermissionMap.getValue(new S32(uid1)));
 
         mBpfNetMaps.setNetPermForUids(PERMISSION_UNINSTALLED, TEST_UIDS);
-        assertNull(mUidPermissionMap.getValue(new U32(uid0)));
-        assertNull(mUidPermissionMap.getValue(new U32(uid1)));
+        assertNull(mUidPermissionMap.getValue(new S32(uid0)));
+        assertNull(mUidPermissionMap.getValue(new S32(uid1)));
     }
 
     @Test
@@ -898,13 +899,13 @@
         mCookieTagMap.updateEntry(new CookieTagMapKey(0), new CookieTagMapValue(0, 0));
 
         // mUidOwnerMap has 2 entries
-        mUidOwnerMap.updateEntry(new U32(0), new UidOwnerValue(0, 0));
-        mUidOwnerMap.updateEntry(new U32(1), new UidOwnerValue(0, 0));
+        mUidOwnerMap.updateEntry(new S32(0), new UidOwnerValue(0, 0));
+        mUidOwnerMap.updateEntry(new S32(1), new UidOwnerValue(0, 0));
 
         // mUidPermissionMap has 3 entries
-        mUidPermissionMap.updateEntry(new U32(0), new U8((short) 0));
-        mUidPermissionMap.updateEntry(new U32(1), new U8((short) 0));
-        mUidPermissionMap.updateEntry(new U32(2), new U8((short) 0));
+        mUidPermissionMap.updateEntry(new S32(0), new U8((short) 0));
+        mUidPermissionMap.updateEntry(new S32(1), new U8((short) 0));
+        mUidPermissionMap.updateEntry(new S32(2), new U8((short) 0));
 
         final int ret = mBpfNetMaps.pullBpfMapInfoAtom(NETWORK_BPF_MAP_INFO, new ArrayList<>());
         assertEquals(StatsManager.PULL_SUCCESS, ret);