Block incoming packets in VPN Lockdown mode.

Currently, even when VPN Lockdown mode is enabled, incoming packets are
not dropped if VPN is not connected.

This commit fixed this issue.
After this commit, If VPN Lockdown mode is enabled, incoming packets
are dropped regardless of the VPN connectivity.

Bug: 206482423
Test: atest TrafficControllerTest ConnectivityServiceTest PermissionMonitorTest
Change-Id: If52ece613c8aac1073355e43b6fb9cb3fcc87d1d
(cherry picked from commit b08654ca0450d021da709a762ab509a8d4f87d40)
Merged-In: If52ece613c8aac1073355e43b6fb9cb3fcc87d1d

1 files changed, 85 insertions, 8 deletions

diff --git a/tests/unit/java/com/android/server/ConnectivityServiceTest.java b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
index b7da17befa..9961978da3 100644
--- a/tests/unit/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
@@ -52,6 +52,9 @@ import static android.net.ConnectivityManager.BLOCKED_REASON_NONE;
 import static android.net.ConnectivityManager.CONNECTIVITY_ACTION;
 import static android.net.ConnectivityManager.EXTRA_NETWORK_INFO;
 import static android.net.ConnectivityManager.EXTRA_NETWORK_TYPE;
+import static android.net.ConnectivityManager.FIREWALL_CHAIN_LOCKDOWN_VPN;
+import static android.net.ConnectivityManager.FIREWALL_RULE_ALLOW;
+import static android.net.ConnectivityManager.FIREWALL_RULE_DENY;
 import static android.net.ConnectivityManager.PROFILE_NETWORK_PREFERENCE_DEFAULT;
 import static android.net.ConnectivityManager.PROFILE_NETWORK_PREFERENCE_ENTERPRISE;
 import static android.net.ConnectivityManager.PROFILE_NETWORK_PREFERENCE_ENTERPRISE_NO_FALLBACK;
@@ -9502,6 +9505,46 @@ public class ConnectivityServiceTest {
         b2.expectBroadcast();
     }
 
+    @Test
+    public void testLockdownSetFirewallUidRule() throws Exception {
+        // For ConnectivityService#setAlwaysOnVpnPackage.
+        mServiceContext.setPermission(
+                Manifest.permission.CONTROL_ALWAYS_ON_VPN, PERMISSION_GRANTED);
+        // Needed to call Vpn#setAlwaysOnPackage.
+        mServiceContext.setPermission(Manifest.permission.CONTROL_VPN, PERMISSION_GRANTED);
+        // Needed to call Vpn#isAlwaysOnPackageSupported.
+        mServiceContext.setPermission(NETWORK_SETTINGS, PERMISSION_GRANTED);
+
+        // Enable Lockdown
+        final ArrayList<String> allowList = new ArrayList<>();
+        mVpnManagerService.setAlwaysOnVpnPackage(PRIMARY_USER, ALWAYS_ON_PACKAGE,
+                true /* lockdown */, allowList);
+        waitForIdle();
+
+        // Lockdown rule is set to apps uids
+        verify(mBpfNetMaps).setUidRule(
+                eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(APP1_UID), eq(FIREWALL_RULE_DENY));
+        verify(mBpfNetMaps).setUidRule(
+                eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(APP2_UID), eq(FIREWALL_RULE_DENY));
+
+        reset(mBpfNetMaps);
+
+        // Disable lockdown
+        mVpnManagerService.setAlwaysOnVpnPackage(PRIMARY_USER, null, false /* lockdown */,
+                allowList);
+        waitForIdle();
+
+        // Lockdown rule is removed from apps uids
+        verify(mBpfNetMaps).setUidRule(
+                eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(APP1_UID), eq(FIREWALL_RULE_ALLOW));
+        verify(mBpfNetMaps).setUidRule(
+                eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(APP2_UID), eq(FIREWALL_RULE_ALLOW));
+
+        // Interface rules are not changed by Lockdown mode enable/disable
+        verify(mBpfNetMaps, never()).addUidInterfaceRules(any(), any());
+        verify(mBpfNetMaps, never()).removeUidInterfaceRules(any());
+    }
+
     /**
      * Test mutable and requestable network capabilities such as
      * {@link NetworkCapabilities#NET_CAPABILITY_TRUSTED} and
@@ -10373,7 +10416,7 @@ public class ConnectivityServiceTest {
         verify(mBpfNetMaps, times(2)).addUidInterfaceRules(eq("tun0"), uidCaptor.capture());
         assertContainsExactly(uidCaptor.getAllValues().get(0), APP1_UID, APP2_UID);
         assertContainsExactly(uidCaptor.getAllValues().get(1), APP1_UID, APP2_UID);
-        assertTrue(mService.mPermissionMonitor.getVpnUidRanges("tun0").equals(vpnRange));
+        assertTrue(mService.mPermissionMonitor.getVpnInterfaceUidRanges("tun0").equals(vpnRange));
 
         mMockVpn.disconnect();
         waitForIdle();
@@ -10381,11 +10424,11 @@ public class ConnectivityServiceTest {
         // Disconnected VPN should have interface rules removed
         verify(mBpfNetMaps).removeUidInterfaceRules(uidCaptor.capture());
         assertContainsExactly(uidCaptor.getValue(), APP1_UID, APP2_UID);
-        assertNull(mService.mPermissionMonitor.getVpnUidRanges("tun0"));
+        assertNull(mService.mPermissionMonitor.getVpnInterfaceUidRanges("tun0"));
     }
 
     @Test
-    public void testLegacyVpnDoesNotResultInInterfaceFilteringRule() throws Exception {
+    public void testLegacyVpnSetInterfaceFilteringRuleWithWildcard() throws Exception {
         LinkProperties lp = new LinkProperties();
         lp.setInterfaceName("tun0");
         lp.addRoute(new RouteInfo(new IpPrefix(Inet6Address.ANY, 0), null));
@@ -10395,13 +10438,29 @@ public class ConnectivityServiceTest {
         mMockVpn.establish(lp, Process.SYSTEM_UID, vpnRange);
         assertVpnUidRangesUpdated(true, vpnRange, Process.SYSTEM_UID);
 
-        // Legacy VPN should not have interface rules set up
-        verify(mBpfNetMaps, never()).addUidInterfaceRules(any(), any());
+        // A connected Legacy VPN should have interface rules with null interface.
+        // Null Interface is a wildcard and this accepts traffic from all the interfaces.
+        // There are two expected invocations, one during the VPN initial connection,
+        // one during the VPN LinkProperties update.
+        ArgumentCaptor<int[]> uidCaptor = ArgumentCaptor.forClass(int[].class);
+        verify(mBpfNetMaps, times(2)).addUidInterfaceRules(
+                eq(null) /* iface */, uidCaptor.capture());
+        assertContainsExactly(uidCaptor.getAllValues().get(0), APP1_UID, APP2_UID, VPN_UID);
+        assertContainsExactly(uidCaptor.getAllValues().get(1), APP1_UID, APP2_UID, VPN_UID);
+        assertEquals(mService.mPermissionMonitor.getVpnInterfaceUidRanges(null /* iface */),
+                vpnRange);
+
+        mMockVpn.disconnect();
+        waitForIdle();
+
+        // Disconnected VPN should have interface rules removed
+        verify(mBpfNetMaps).removeUidInterfaceRules(uidCaptor.capture());
+        assertContainsExactly(uidCaptor.getValue(), APP1_UID, APP2_UID, VPN_UID);
+        assertNull(mService.mPermissionMonitor.getVpnInterfaceUidRanges(null /* iface */));
     }
 
     @Test
-    public void testLocalIpv4OnlyVpnDoesNotResultInInterfaceFilteringRule()
-            throws Exception {
+    public void testLocalIpv4OnlyVpnSetInterfaceFilteringRuleWithWildcard() throws Exception {
         LinkProperties lp = new LinkProperties();
         lp.setInterfaceName("tun0");
         lp.addRoute(new RouteInfo(new IpPrefix("192.0.2.0/24"), null, "tun0"));
@@ -10412,7 +10471,25 @@ public class ConnectivityServiceTest {
         assertVpnUidRangesUpdated(true, vpnRange, Process.SYSTEM_UID);
 
         // IPv6 unreachable route should not be misinterpreted as a default route
-        verify(mBpfNetMaps, never()).addUidInterfaceRules(any(), any());
+        // A connected VPN should have interface rules with null interface.
+        // Null Interface is a wildcard and this accepts traffic from all the interfaces.
+        // There are two expected invocations, one during the VPN initial connection,
+        // one during the VPN LinkProperties update.
+        ArgumentCaptor<int[]> uidCaptor = ArgumentCaptor.forClass(int[].class);
+        verify(mBpfNetMaps, times(2)).addUidInterfaceRules(
+                eq(null) /* iface */, uidCaptor.capture());
+        assertContainsExactly(uidCaptor.getAllValues().get(0), APP1_UID, APP2_UID, VPN_UID);
+        assertContainsExactly(uidCaptor.getAllValues().get(1), APP1_UID, APP2_UID, VPN_UID);
+        assertEquals(mService.mPermissionMonitor.getVpnInterfaceUidRanges(null /* iface */),
+                vpnRange);
+
+        mMockVpn.disconnect();
+        waitForIdle();
+
+        // Disconnected VPN should have interface rules removed
+        verify(mBpfNetMaps).removeUidInterfaceRules(uidCaptor.capture());
+        assertContainsExactly(uidCaptor.getValue(), APP1_UID, APP2_UID, VPN_UID);
+        assertNull(mService.mPermissionMonitor.getVpnInterfaceUidRanges(null /* iface */));
     }
 
     @Test