Enforce that NetworkAgentInfo fields are never null.

These fields have been recently audited, confirmed never to be
null, and annotated @NonNull. Ensure that they can never become
null by throwing exceptions in the codepaths that set them.
Also remove some null checks.

Test: atest FrameworksNetTests
Change-Id: I6ce5bb4d69a990f1c857c599b7e50e372352eb87

services/core/java/com/android/server/ConnectivityService.java

@@ -1644,7 +1644,6 @@ public class ConnectivityService extends IConnectivityManager.Stub
     private NetworkCapabilities getNetworkCapabilitiesInternal(NetworkAgentInfo nai) {
         if (nai == null) return null;
         synchronized (nai) {
-            if (nai.networkCapabilities == null) return null;
             return networkCapabilitiesRestrictedForCallerPermissions(
                     nai.networkCapabilities, Binder.getCallingPid(), mDeps.getCallingUid());
         }
@@ -2768,7 +2767,6 @@ public class ConnectivityService extends IConnectivityManager.Stub
     }
 
     private boolean isLiveNetworkAgent(NetworkAgentInfo nai, int what) {
-        if (nai.network == null) return false;
         final NetworkAgentInfo officialNai = getNetworkAgentInfoForNetwork(nai.network);
         if (officialNai != null && officialNai.equals(nai)) return true;
         if (officialNai != null || VDBG) {
@@ -6059,6 +6057,10 @@ public class ConnectivityService extends IConnectivityManager.Stub
     public Network registerNetworkAgent(INetworkAgent na, NetworkInfo networkInfo,
             LinkProperties linkProperties, NetworkCapabilities networkCapabilities,
             int currentScore, NetworkAgentConfig networkAgentConfig, int providerId) {
+        Objects.requireNonNull(networkInfo, "networkInfo must not be null");
+        Objects.requireNonNull(linkProperties, "linkProperties must not be null");
+        Objects.requireNonNull(networkCapabilities, "networkCapabilities must not be null");
+        Objects.requireNonNull(networkAgentConfig, "networkAgentConfig must not be null");
         if (networkCapabilities.hasTransport(TRANSPORT_TEST)) {
             enforceAnyPermissionOf(Manifest.permission.MANAGE_TEST_NETWORKS);
         } else {
@@ -7574,10 +7576,6 @@ public class ConnectivityService extends IConnectivityManager.Stub
         if (!networkAgent.everConnected && state == NetworkInfo.State.CONNECTED) {
             networkAgent.everConnected = true;
 
-            if (networkAgent.linkProperties == null) {
-                Log.wtf(TAG, networkAgent.toShortString() + " connected with null LinkProperties");
-            }
-
             // NetworkCapabilities need to be set before sending the private DNS config to
             // NetworkMonitor, otherwise NetworkMonitor cannot determine if validation is required.
             networkAgent.getAndSetNetworkCapabilities(networkAgent.networkCapabilities);

services/core/java/com/android/server/connectivity/Nat464Xlat.java

@@ -246,11 +246,6 @@ public class Nat464Xlat extends BaseNetworkObserver {
             return;
         }
 
-        if (mNetwork.linkProperties == null) {
-            Log.e(TAG, "startClat: Can't start clat with null LinkProperties");
-            return;
-        }
-
         String baseIface = mNetwork.linkProperties.getInterfaceName();
         if (baseIface == null) {
             Log.e(TAG, "startClat: Can't start clat on null interface");

services/core/java/com/android/server/connectivity/NetworkAgentInfo.java

@@ -329,6 +329,12 @@ public class NetworkAgentInfo implements Comparable<NetworkAgentInfo> {
             Handler handler, NetworkAgentConfig config, ConnectivityService connService, INetd netd,
             IDnsResolver dnsResolver, INetworkManagementService nms, int factorySerialNumber,
             int creatorUid) {
+        Objects.requireNonNull(net);
+        Objects.requireNonNull(info);
+        Objects.requireNonNull(lp);
+        Objects.requireNonNull(nc);
+        Objects.requireNonNull(context);
+        Objects.requireNonNull(config);
         networkAgent = na;
         network = net;
         networkInfo = info;
@@ -536,19 +542,22 @@ public class NetworkAgentInfo implements Comparable<NetworkAgentInfo> {
         }
 
         @Override
-        public void sendNetworkCapabilities(NetworkCapabilities nc) {
+        public void sendNetworkCapabilities(@NonNull NetworkCapabilities nc) {
+            Objects.requireNonNull(nc);
             mHandler.obtainMessage(NetworkAgent.EVENT_NETWORK_CAPABILITIES_CHANGED,
                     new Pair<>(NetworkAgentInfo.this, nc)).sendToTarget();
         }
 
         @Override
-        public void sendLinkProperties(LinkProperties lp) {
+        public void sendLinkProperties(@NonNull LinkProperties lp) {
+            Objects.requireNonNull(lp);
             mHandler.obtainMessage(NetworkAgent.EVENT_NETWORK_PROPERTIES_CHANGED,
                     new Pair<>(NetworkAgentInfo.this, lp)).sendToTarget();
         }
 
         @Override
-        public void sendNetworkInfo(NetworkInfo info) {
+        public void sendNetworkInfo(@NonNull NetworkInfo info) {
+            Objects.requireNonNull(info);
             mHandler.obtainMessage(NetworkAgent.EVENT_NETWORK_INFO_CHANGED,
                     new Pair<>(NetworkAgentInfo.this, info)).sendToTarget();
         }

tests/net/java/com/android/server/ConnectivityServiceTest.java

@@ -8112,11 +8112,18 @@ public class ConnectivityServiceTest {
         assertTrue(mService.mConnectivityDiagnosticsCallbacks.containsKey(mIBinder));
     }
 
+    public NetworkAgentInfo fakeMobileNai(NetworkCapabilities nc) {
+        final NetworkInfo info = new NetworkInfo(TYPE_MOBILE, TelephonyManager.NETWORK_TYPE_LTE,
+                ConnectivityManager.getNetworkTypeName(TYPE_MOBILE),
+                TelephonyManager.getNetworkTypeName(TelephonyManager.NETWORK_TYPE_LTE));
+        return new NetworkAgentInfo(null, new Network(NET_ID), info, new LinkProperties(),
+                nc, 0, mServiceContext, null, new NetworkAgentConfig(), mService, null, null, null,
+                0, INVALID_UID);
+    }
+
     @Test
     public void testCheckConnectivityDiagnosticsPermissionsNetworkStack() throws Exception {
-        final NetworkAgentInfo naiWithoutUid =
+        final NetworkAgentInfo naiWithoutUid = fakeMobileNai(new NetworkCapabilities());
-                new NetworkAgentInfo(null, null, null, null, new NetworkCapabilities(), 0,
-                        mServiceContext, null, null, mService, null, null, null, 0, INVALID_UID);
 
         mServiceContext.setPermission(
                 android.Manifest.permission.NETWORK_STACK, PERMISSION_GRANTED);
@@ -8129,9 +8136,7 @@ public class ConnectivityServiceTest {
 
     @Test
     public void testCheckConnectivityDiagnosticsPermissionsWrongUidPackageName() throws Exception {
-        final NetworkAgentInfo naiWithoutUid =
+        final NetworkAgentInfo naiWithoutUid = fakeMobileNai(new NetworkCapabilities());
-                new NetworkAgentInfo(null, null, null, null, new NetworkCapabilities(), 0,
-                        mServiceContext, null, null, mService, null, null, null, 0, INVALID_UID);
 
         mServiceContext.setPermission(android.Manifest.permission.NETWORK_STACK, PERMISSION_DENIED);
 
@@ -8144,9 +8149,7 @@ public class ConnectivityServiceTest {
 
     @Test
     public void testCheckConnectivityDiagnosticsPermissionsNoLocationPermission() throws Exception {
-        final NetworkAgentInfo naiWithoutUid =
+        final NetworkAgentInfo naiWithoutUid = fakeMobileNai(new NetworkCapabilities());
-                new NetworkAgentInfo(null, null, null, null, new NetworkCapabilities(), 0,
-                        mServiceContext, null, null, mService, null, null, null, 0, INVALID_UID);
 
         mServiceContext.setPermission(android.Manifest.permission.NETWORK_STACK, PERMISSION_DENIED);
 
@@ -8159,10 +8162,7 @@ public class ConnectivityServiceTest {
 
     @Test
     public void testCheckConnectivityDiagnosticsPermissionsActiveVpn() throws Exception {
-        final Network network = new Network(NET_ID);
+        final NetworkAgentInfo naiWithoutUid = fakeMobileNai(new NetworkCapabilities());
-        final NetworkAgentInfo naiWithoutUid =
-                new NetworkAgentInfo(null, network, null, null, new NetworkCapabilities(), 0,
-                        mServiceContext, null, null, mService, null, null, null, 0, INVALID_UID);
 
         mMockVpn.establishForMyUid();
         assertUidRangesUpdatedForMyUid(true);
@@ -8172,7 +8172,7 @@ public class ConnectivityServiceTest {
         setupLocationPermissions(Build.VERSION_CODES.Q, true, AppOpsManager.OPSTR_FINE_LOCATION,
                 Manifest.permission.ACCESS_FINE_LOCATION);
 
-        assertTrue(mService.setUnderlyingNetworksForVpn(new Network[] {network}));
+        assertTrue(mService.setUnderlyingNetworksForVpn(new Network[] {naiWithoutUid.network}));
         waitForIdle();
         assertTrue(
                 "Active VPN permission not applied",
@@ -8193,9 +8193,7 @@ public class ConnectivityServiceTest {
     public void testCheckConnectivityDiagnosticsPermissionsNetworkAdministrator() throws Exception {
         final NetworkCapabilities nc = new NetworkCapabilities();
         nc.setAdministratorUids(new int[] {Process.myUid()});
-        final NetworkAgentInfo naiWithUid =
+        final NetworkAgentInfo naiWithUid = fakeMobileNai(nc);
-                new NetworkAgentInfo(null, null, null, null, nc, 0, mServiceContext, null, null,
-                        mService, null, null, null, 0, INVALID_UID);
 
         setupLocationPermissions(Build.VERSION_CODES.Q, true, AppOpsManager.OPSTR_FINE_LOCATION,
                 Manifest.permission.ACCESS_FINE_LOCATION);
@@ -8212,9 +8210,7 @@ public class ConnectivityServiceTest {
         final NetworkCapabilities nc = new NetworkCapabilities();
         nc.setOwnerUid(Process.myUid());
         nc.setAdministratorUids(new int[] {Process.myUid()});
-        final NetworkAgentInfo naiWithUid =
+        final NetworkAgentInfo naiWithUid = fakeMobileNai(nc);
-                new NetworkAgentInfo(null, null, null, null, nc, 0, mServiceContext, null, null,
-                        mService, null, null, null, 0, INVALID_UID);
 
         setupLocationPermissions(Build.VERSION_CODES.Q, true, AppOpsManager.OPSTR_FINE_LOCATION,
                 Manifest.permission.ACCESS_FINE_LOCATION);

tests/net/java/com/android/server/connectivity/LingerMonitorTest.java

@@ -34,7 +34,9 @@ import android.content.res.Resources;
 import android.net.ConnectivityManager;
 import android.net.IDnsResolver;
 import android.net.INetd;
+import android.net.LinkProperties;
 import android.net.Network;
+import android.net.NetworkAgentConfig;
 import android.net.NetworkCapabilities;
 import android.net.NetworkInfo;
 import android.net.NetworkProvider;
@@ -353,9 +355,10 @@ public class LingerMonitorTest {
         NetworkCapabilities caps = new NetworkCapabilities();
         caps.addCapability(0);
         caps.addTransportType(transport);
-        NetworkAgentInfo nai = new NetworkAgentInfo(null, new Network(netId), info, null,
+        NetworkAgentInfo nai = new NetworkAgentInfo(null, new Network(netId), info,
-                caps, 50, mCtx, null, null /* config */, mConnService, mNetd, mDnsResolver, mNMS,
+                new LinkProperties(), caps, 50, mCtx, null, new NetworkAgentConfig() /* config */,
-                NetworkProvider.ID_NONE, Binder.getCallingUid());
+                mConnService, mNetd, mDnsResolver, mNMS, NetworkProvider.ID_NONE,
+                Binder.getCallingUid());
         nai.everValidated = true;
         return nai;
     }