Use java BpfMap in BpfNetMaps#removeNaughtyApp

Bug: 217624062
Test: atest BpfNetMapsTest HostsideRestrictBackgroundNetworkTests
Change-Id: Ibfb3ae48427b7dc5d06708e63f4a16f7527ce86c
diff --git a/service/src/com/android/server/BpfNetMaps.java b/service/src/com/android/server/BpfNetMaps.java
index 3a5fc06..c3302cd 100644
--- a/service/src/com/android/server/BpfNetMaps.java
+++ b/service/src/com/android/server/BpfNetMaps.java
@@ -25,6 +25,7 @@
 import static android.net.ConnectivityManager.FIREWALL_CHAIN_RESTRICTED;
 import static android.net.ConnectivityManager.FIREWALL_CHAIN_STANDBY;
 import static android.system.OsConstants.EINVAL;
+import static android.system.OsConstants.ENOENT;
 import static android.system.OsConstants.EOPNOTSUPP;
 
 import android.net.INetd;
@@ -77,19 +78,19 @@
     private static BpfMap<U32, UidOwnerValue> sUidOwnerMap = null;
 
     // LINT.IfChange(match_type)
-    private static final long NO_MATCH = 0;
-    private static final long HAPPY_BOX_MATCH = (1 << 0);
-    private static final long PENALTY_BOX_MATCH = (1 << 1);
-    private static final long DOZABLE_MATCH = (1 << 2);
-    private static final long STANDBY_MATCH = (1 << 3);
-    private static final long POWERSAVE_MATCH = (1 << 4);
-    private static final long RESTRICTED_MATCH = (1 << 5);
-    private static final long LOW_POWER_STANDBY_MATCH = (1 << 6);
-    private static final long IIF_MATCH = (1 << 7);
-    private static final long LOCKDOWN_VPN_MATCH = (1 << 8);
-    private static final long OEM_DENY_1_MATCH = (1 << 9);
-    private static final long OEM_DENY_2_MATCH = (1 << 10);
-    private static final long OEM_DENY_3_MATCH = (1 << 11);
+    @VisibleForTesting public static final long NO_MATCH = 0;
+    @VisibleForTesting public static final long HAPPY_BOX_MATCH = (1 << 0);
+    @VisibleForTesting public static final long PENALTY_BOX_MATCH = (1 << 1);
+    @VisibleForTesting public static final long DOZABLE_MATCH = (1 << 2);
+    @VisibleForTesting public static final long STANDBY_MATCH = (1 << 3);
+    @VisibleForTesting public static final long POWERSAVE_MATCH = (1 << 4);
+    @VisibleForTesting public static final long RESTRICTED_MATCH = (1 << 5);
+    @VisibleForTesting public static final long LOW_POWER_STANDBY_MATCH = (1 << 6);
+    @VisibleForTesting public static final long IIF_MATCH = (1 << 7);
+    @VisibleForTesting public static final long LOCKDOWN_VPN_MATCH = (1 << 8);
+    @VisibleForTesting public static final long OEM_DENY_1_MATCH = (1 << 9);
+    @VisibleForTesting public static final long OEM_DENY_2_MATCH = (1 << 10);
+    @VisibleForTesting public static final long OEM_DENY_3_MATCH = (1 << 11);
     // LINT.ThenChange(packages/modules/Connectivity/bpf_progs/bpf_shared.h)
 
     // TODO: Use Java BpfMap instead of JNI code (TrafficController) for map update.
@@ -200,6 +201,33 @@
         }
     }
 
+    private void removeRule(final int uid, final long match, final String caller) {
+        try {
+            synchronized (sUidOwnerMap) {
+                final UidOwnerValue oldMatch = sUidOwnerMap.getValue(new U32(uid));
+
+                if (oldMatch == null) {
+                    throw new ServiceSpecificException(ENOENT,
+                            "sUidOwnerMap does not have entry for uid: " + uid);
+                }
+
+                final UidOwnerValue newMatch = new UidOwnerValue(
+                        (match == IIF_MATCH) ? 0 : oldMatch.iif,
+                        oldMatch.rule & ~match
+                );
+
+                if (newMatch.rule == 0) {
+                    sUidOwnerMap.deleteEntry(new U32(uid));
+                } else {
+                    sUidOwnerMap.updateEntry(new U32(uid), newMatch);
+                }
+            }
+        } catch (ErrnoException e) {
+            throw new ServiceSpecificException(e.errno,
+                    caller + " failed to remove rule: " + Os.strerror(e.errno));
+        }
+    }
+
     /**
      * Add naughty app bandwidth rule for specific app
      *
@@ -222,10 +250,8 @@
      *                                  cause of the failure.
      */
     public void removeNaughtyApp(final int uid) {
-        synchronized (sUidOwnerMap) {
-            final int err = native_removeNaughtyApp(uid);
-            maybeThrow(err, "Unable to remove naughty app");
-        }
+        throwIfPreT("removeNaughtyApp is not available on pre-T devices");
+        removeRule(uid, PENALTY_BOX_MATCH, "removeNaughtyApp");
     }
 
     /**
diff --git a/tests/unit/java/com/android/server/BpfNetMapsTest.java b/tests/unit/java/com/android/server/BpfNetMapsTest.java
index eee08e2..79bf66e 100644
--- a/tests/unit/java/com/android/server/BpfNetMapsTest.java
+++ b/tests/unit/java/com/android/server/BpfNetMapsTest.java
@@ -26,8 +26,15 @@
 import static android.net.ConnectivityManager.FIREWALL_CHAIN_STANDBY;
 import static android.net.INetd.PERMISSION_INTERNET;
 
+import static com.android.server.BpfNetMaps.DOZABLE_MATCH;
+import static com.android.server.BpfNetMaps.IIF_MATCH;
+import static com.android.server.BpfNetMaps.PENALTY_BOX_MATCH;
+import static com.android.server.BpfNetMaps.POWERSAVE_MATCH;
+import static com.android.server.BpfNetMaps.RESTRICTED_MATCH;
+
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertThrows;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assume.assumeFalse;
@@ -68,7 +75,9 @@
 
     private static final int TEST_UID = 10086;
     private static final int[] TEST_UIDS = {10002, 10003};
-    private static final String IFNAME = "wlan0";
+    private static final String TEST_IF_NAME = "wlan0";
+    private static final int TEST_IF_INDEX = 7;
+    private static final int NO_IIF = 0;
     private static final String CHAINNAME = "fw_dozable";
     private static final U32 UID_RULES_CONFIGURATION_KEY = new U32(0);
     private static final List<Integer> FIREWALL_CHAINS = List.of(
@@ -100,8 +109,8 @@
     @Test
     public void testBpfNetMapsBeforeT() throws Exception {
         assumeFalse(SdkLevel.isAtLeastT());
-        mBpfNetMaps.addUidInterfaceRules(IFNAME, TEST_UIDS);
-        verify(mNetd).firewallAddUidInterfaceRules(IFNAME, TEST_UIDS);
+        mBpfNetMaps.addUidInterfaceRules(TEST_IF_NAME, TEST_UIDS);
+        verify(mNetd).firewallAddUidInterfaceRules(TEST_IF_NAME, TEST_UIDS);
         mBpfNetMaps.removeUidInterfaceRules(TEST_UIDS);
         verify(mNetd).firewallRemoveUidInterfaceRules(TEST_UIDS);
         mBpfNetMaps.setNetPermForUids(PERMISSION_INTERNET, TEST_UIDS);
@@ -241,4 +250,53 @@
         assertThrows(UnsupportedOperationException.class,
                 () -> mBpfNetMaps.setChildChain(FIREWALL_CHAIN_DOZABLE, true /* enable */));
     }
+
+    private void checkUidOwnerValue(final long uid, final long expectedIif,
+            final long expectedMatch) throws Exception {
+        final UidOwnerValue config = mUidOwnerMap.getValue(new U32(uid));
+        if (expectedMatch == 0) {
+            assertNull(config);
+        } else {
+            assertEquals(expectedIif, config.iif);
+            assertEquals(expectedMatch, config.rule);
+        }
+    }
+
+    private void doTestRemoveNaughtyApp(final long iif, final long match) throws Exception {
+        mUidOwnerMap.updateEntry(new U32(TEST_UID), new UidOwnerValue(iif, match));
+
+        mBpfNetMaps.removeNaughtyApp(TEST_UID);
+
+        checkUidOwnerValue(TEST_UID, iif, match & ~PENALTY_BOX_MATCH);
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testRemoveNaughtyApp() throws Exception {
+        doTestRemoveNaughtyApp(NO_IIF, PENALTY_BOX_MATCH);
+
+        // PENALTY_BOX_MATCH with other matches
+        doTestRemoveNaughtyApp(NO_IIF, PENALTY_BOX_MATCH | DOZABLE_MATCH | POWERSAVE_MATCH);
+
+        // PENALTY_BOX_MATCH with IIF_MATCH
+        doTestRemoveNaughtyApp(TEST_IF_INDEX, PENALTY_BOX_MATCH | IIF_MATCH);
+
+        // PENALTY_BOX_MATCH is not enabled
+        doTestRemoveNaughtyApp(NO_IIF, DOZABLE_MATCH | POWERSAVE_MATCH | RESTRICTED_MATCH);
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testRemoveNaughtyAppMissingUid() {
+        // UidOwnerMap does not have entry for TEST_UID
+        assertThrows(ServiceSpecificException.class,
+                () -> mBpfNetMaps.removeNaughtyApp(TEST_UID));
+    }
+
+    @Test
+    @IgnoreAfter(Build.VERSION_CODES.S_V2)
+    public void testRemoveNaughtyAppBeforeT() {
+        assertThrows(UnsupportedOperationException.class,
+                () -> mBpfNetMaps.removeNaughtyApp(TEST_UID));
+    }
 }