Merge "Implement DisconnectingState"

services/core/java/com/android/server/vcn/VcnGatewayConnection.java

@@ -122,7 +122,9 @@ public class VcnGatewayConnection extends StateMachine {
     private static final int TOKEN_ALL = Integer.MIN_VALUE;
 
     private static final int NETWORK_LOSS_DISCONNECT_TIMEOUT_SECONDS = 30;
-    private static final int TEARDOWN_TIMEOUT_SECONDS = 5;
+
+    @VisibleForTesting(visibility = Visibility.PRIVATE)
+    static final int TEARDOWN_TIMEOUT_SECONDS = 5;
 
     private interface EventInfo {}
 
@@ -412,13 +414,6 @@ public class VcnGatewayConnection extends StateMachine {
      */
     private int mCurrentToken = -1;
 
-    /**
-     * The next usable token.
-     *
-     * <p>A new token MUST be used for all new IKE sessions.
-     */
-    private int mNextToken = 0;
-
     /**
      * The number of unsuccessful attempts since the last successful connection.
      *
@@ -440,7 +435,7 @@ public class VcnGatewayConnection extends StateMachine {
      * <p>Set in Connecting or Migrating States, always @NonNull in Connecting, Connected, and
      * Migrating states, null otherwise.
      */
-    private IkeSession mIkeSession;
+    private VcnIkeSession mIkeSession;
 
     /**
      * The last known child configuration.
@@ -774,7 +769,70 @@ public class VcnGatewayConnection extends StateMachine {
      */
     private class DisconnectingState extends ActiveBaseState {
         @Override
-        protected void processStateMsg(Message msg) {}
+        protected void enterState() throws Exception {
+            if (mIkeSession == null) {
+                Slog.wtf(TAG, "IKE session was already closed when entering Disconnecting state.");
+                sendMessage(EVENT_SESSION_CLOSED, mCurrentToken);
+                return;
+            }
+
+            // If underlying network has already been lost, save some time and just kill the session
+            if (mUnderlying == null) {
+                // Will trigger a EVENT_SESSION_CLOSED as IkeSession shuts down.
+                mIkeSession.kill();
+                return;
+            }
+
+            sendMessageDelayed(
+                    EVENT_TEARDOWN_TIMEOUT_EXPIRED,
+                    mCurrentToken,
+                    TimeUnit.SECONDS.toMillis(TEARDOWN_TIMEOUT_SECONDS));
+        }
+
+        @Override
+        protected void processStateMsg(Message msg) {
+            switch (msg.what) {
+                case EVENT_UNDERLYING_NETWORK_CHANGED: // Fallthrough
+                    mUnderlying = ((EventUnderlyingNetworkChangedInfo) msg.obj).newUnderlying;
+
+                    // If we received a new underlying network, continue.
+                    if (mUnderlying != null) {
+                        break;
+                    }
+
+                    // Fallthrough; no network exists to send IKE close session requests.
+                case EVENT_TEARDOWN_TIMEOUT_EXPIRED:
+                    // Grace period ended. Kill session, triggering EVENT_SESSION_CLOSED
+                    mIkeSession.kill();
+
+                    break;
+                case EVENT_DISCONNECT_REQUESTED:
+                    teardownNetwork();
+
+                    String reason = ((EventDisconnectRequestedInfo) msg.obj).reason;
+                    if (reason.equals(DISCONNECT_REASON_UNDERLYING_NETWORK_LOST)) {
+                        // Will trigger EVENT_SESSION_CLOSED immediately.
+                        mIkeSession.kill();
+                        break;
+                    }
+
+                    // Otherwise we are already in the process of shutting down.
+                    break;
+                case EVENT_SESSION_CLOSED:
+                    mIkeSession = null;
+
+                    if (mIsRunning && mUnderlying != null) {
+                        transitionTo(mRetryTimeoutState);
+                    } else {
+                        teardownNetwork();
+                        transitionTo(mDisconnectedState);
+                    }
+                    break;
+                default:
+                    logUnhandledMessage(msg);
+                    break;
+            }
+        }
     }
 
     /**
@@ -946,6 +1004,38 @@ public class VcnGatewayConnection extends StateMachine {
         mIsRunning = isRunning;
     }
 
+    @VisibleForTesting(visibility = Visibility.PRIVATE)
+    VcnIkeSession getIkeSession() {
+        return mIkeSession;
+    }
+
+    @VisibleForTesting(visibility = Visibility.PRIVATE)
+    void setIkeSession(@Nullable VcnIkeSession session) {
+        mIkeSession = session;
+    }
+
+    private IkeSessionParams buildIkeParams() {
+        // TODO: Implement this with ConnectingState
+        return null;
+    }
+
+    private ChildSessionParams buildChildParams() {
+        // TODO: Implement this with ConnectingState
+        return null;
+    }
+
+    @VisibleForTesting(visibility = Visibility.PRIVATE)
+    VcnIkeSession buildIkeSession() {
+        final int token = ++mCurrentToken;
+
+        return mDeps.newIkeSession(
+                mVcnContext,
+                buildIkeParams(),
+                buildChildParams(),
+                new IkeSessionCallbackImpl(token),
+                new ChildSessionCallbackImpl(token));
+    }
+
     /** External dependencies used by VcnGatewayConnection, for injection in tests */
     @VisibleForTesting(visibility = Visibility.PRIVATE)
     public static class Dependencies {
@@ -958,19 +1048,67 @@ public class VcnGatewayConnection extends StateMachine {
         }
 
         /** Builds a new IkeSession. */
-        public IkeSession newIkeSession(
+        public VcnIkeSession newIkeSession(
                 VcnContext vcnContext,
                 IkeSessionParams ikeSessionParams,
                 ChildSessionParams childSessionParams,
                 IkeSessionCallback ikeSessionCallback,
                 ChildSessionCallback childSessionCallback) {
-            return new IkeSession(
-                    vcnContext.getContext(),
+            return new VcnIkeSession(
+                    vcnContext,
                     ikeSessionParams,
                     childSessionParams,
-                    new HandlerExecutor(new Handler(vcnContext.getLooper())),
                     ikeSessionCallback,
                     childSessionCallback);
         }
     }
+
+    /** Proxy implementation of IKE session, used for testing. */
+    @VisibleForTesting(visibility = Visibility.PRIVATE)
+    public static class VcnIkeSession {
+        private final IkeSession mImpl;
+
+        public VcnIkeSession(
+                VcnContext vcnContext,
+                IkeSessionParams ikeSessionParams,
+                ChildSessionParams childSessionParams,
+                IkeSessionCallback ikeSessionCallback,
+                ChildSessionCallback childSessionCallback) {
+            mImpl =
+                    new IkeSession(
+                            vcnContext.getContext(),
+                            ikeSessionParams,
+                            childSessionParams,
+                            new HandlerExecutor(new Handler(vcnContext.getLooper())),
+                            ikeSessionCallback,
+                            childSessionCallback);
+        }
+
+        /** Creates a new IKE Child session. */
+        public void openChildSession(
+                @NonNull ChildSessionParams childSessionParams,
+                @NonNull ChildSessionCallback childSessionCallback) {
+            mImpl.openChildSession(childSessionParams, childSessionCallback);
+        }
+
+        /** Closes an IKE session as identified by the ChildSessionCallback. */
+        public void closeChildSession(@NonNull ChildSessionCallback childSessionCallback) {
+            mImpl.closeChildSession(childSessionCallback);
+        }
+
+        /** Gracefully closes this IKE Session, waiting for remote acknowledgement. */
+        public void close() {
+            mImpl.close();
+        }
+
+        /** Forcibly kills this IKE Session, without waiting for a closure confirmation. */
+        public void kill() {
+            mImpl.kill();
+        }
+
+        /** Sets the underlying network used by the IkeSession. */
+        public void setNetwork(@NonNull Network network) {
+            mImpl.setNetwork(network);
+        }
+    }
 }

tests/vcn/java/com/android/server/vcn/VcnGatewayConnectionDisconnectingStateTest.java

@@ -0,0 +1,71 @@
+/*
+ * 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.server.vcn;
+
+import static com.android.server.vcn.VcnGatewayConnection.TEARDOWN_TIMEOUT_SECONDS;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.verify;
+
+import androidx.test.filters.SmallTest;
+import androidx.test.runner.AndroidJUnit4;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.util.concurrent.TimeUnit;
+
+/** Tests for VcnGatewayConnection.DisconnectedState */
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public class VcnGatewayConnectionDisconnectingStateTest extends VcnGatewayConnectionTestBase {
+    @Before
+    public void setUp() throws Exception {
+        super.setUp();
+
+        mGatewayConnection.setIkeSession(mGatewayConnection.buildIkeSession());
+
+        mGatewayConnection.transitionTo(mGatewayConnection.mDisconnectingState);
+        mTestLooper.dispatchAll();
+    }
+
+    @Test
+    public void testIkeSessionClosed() throws Exception {
+        getIkeSessionCallback().onClosed();
+        mTestLooper.dispatchAll();
+
+        assertEquals(mGatewayConnection.mDisconnectedState, mGatewayConnection.getCurrentState());
+    }
+
+    @Test
+    public void testTimeoutExpired() throws Exception {
+        mTestLooper.moveTimeForward(TimeUnit.SECONDS.toMillis(TEARDOWN_TIMEOUT_SECONDS));
+        mTestLooper.dispatchAll();
+
+        verify(mMockIkeSession).kill();
+    }
+
+    @Test
+    public void testTeardown() throws Exception {
+        mGatewayConnection.teardownAsynchronously();
+        mTestLooper.dispatchAll();
+
+        // Should do nothing; already tearing down.
+        assertEquals(mGatewayConnection.mDisconnectingState, mGatewayConnection.getCurrentState());
+    }
+}

tests/vcn/java/com/android/server/vcn/VcnGatewayConnectionTestBase.java

@@ -17,11 +17,13 @@
 package com.android.server.vcn;
 
 import static com.android.server.vcn.UnderlyingNetworkTracker.UnderlyingNetworkRecord;
+import static com.android.server.vcn.VcnGatewayConnection.VcnIkeSession;
 import static com.android.server.vcn.VcnTestUtils.setupIpSecManager;
 
 import static org.mockito.Matchers.any;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
 
 import android.annotation.NonNull;
 import android.content.Context;
@@ -30,6 +32,7 @@ import android.net.IpSecTunnelInterfaceResponse;
 import android.net.LinkProperties;
 import android.net.Network;
 import android.net.NetworkCapabilities;
+import android.net.ipsec.ike.IkeSessionCallback;
 import android.net.vcn.VcnGatewayConnectionConfig;
 import android.net.vcn.VcnGatewayConnectionConfigTest;
 import android.os.ParcelUuid;
@@ -38,6 +41,7 @@ import android.os.test.TestLooper;
 import com.android.server.IpSecService;
 
 import org.junit.Before;
+import org.mockito.ArgumentCaptor;
 
 import java.util.UUID;
 
@@ -68,6 +72,7 @@ public class VcnGatewayConnectionTestBase {
 
     @NonNull protected final IpSecService mIpSecSvc;
 
+    protected VcnIkeSession mMockIkeSession;
     protected VcnGatewayConnection mGatewayConnection;
 
     public VcnGatewayConnectionTestBase() {
@@ -100,6 +105,16 @@ public class VcnGatewayConnectionTestBase {
                         TEST_IPSEC_TUNNEL_IFACE);
         doReturn(resp).when(mIpSecSvc).createTunnelInterface(any(), any(), any(), any(), any());
 
+        mMockIkeSession = mock(VcnIkeSession.class);
+        doReturn(mMockIkeSession).when(mDeps).newIkeSession(any(), any(), any(), any(), any());
+
         mGatewayConnection = new VcnGatewayConnection(mVcnContext, TEST_SUB_GRP, mConfig, mDeps);
     }
+
+    protected IkeSessionCallback getIkeSessionCallback() {
+        ArgumentCaptor<IkeSessionCallback> captor =
+                ArgumentCaptor.forClass(IkeSessionCallback.class);
+        verify(mDeps).newIkeSession(any(), any(), any(), captor.capture(), any());
+        return captor.getValue();
+    }
 }