Merge "Reset Ike session if stall is not recovered by MOBIKE" am: 246fc31ef5

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2159077

Change-Id: Ife1ebd8e4bbfcbf37dbff8b4cf0de1b7dbfb6583
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

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

@@ -79,6 +79,7 @@ import android.net.NetworkScore;
 import android.net.RouteInfo;
 import android.net.UidRangeParcel;
 import android.net.UnderlyingNetworkInfo;
+import android.net.Uri;
 import android.net.VpnManager;
 import android.net.VpnProfileState;
 import android.net.VpnService;
@@ -225,6 +226,16 @@ public class Vpn {
      */
     private static final int VPN_DEFAULT_SCORE = 101;
 
+    /**
+     * The reset session timer for data stall. If a session has not successfully revalidated after
+     * the delay, the session will be torn down and restarted in an attempt to recover. Delay
+     * counter is reset on successful validation only.
+     *
+     * <p>If retries have exceeded the length of this array, the last entry in the array will be
+     * used as a repeating interval.
+     */
+    private static final long[] DATA_STALL_RESET_DELAYS_SEC = {30L, 60L, 120L, 240L, 480L, 960L};
+
     /**
      * The initial token value of IKE session.
      */
@@ -271,6 +282,7 @@ public class Vpn {
     private final UserManager mUserManager;
 
     private final VpnProfileStore mVpnProfileStore;
+    protected boolean mDataStallSuspected = false;
 
     @VisibleForTesting
     VpnProfileStore getVpnProfileStore() {
@@ -522,10 +534,28 @@ public class Vpn {
                 @NonNull LinkProperties lp,
                 @NonNull NetworkScore score,
                 @NonNull NetworkAgentConfig config,
-                @Nullable NetworkProvider provider) {
+                @Nullable NetworkProvider provider,
+                @Nullable ValidationStatusCallback callback) {
             return new VpnNetworkAgentWrapper(
-                    context, looper, logTag, nc, lp, score, config, provider);
+                    context, looper, logTag, nc, lp, score, config, provider, callback);
         }
+
+        /**
+         * Get the length of time to wait before resetting the ike session when a data stall is
+         * suspected.
+         */
+        public long getDataStallResetSessionSeconds(int count) {
+            if (count >= DATA_STALL_RESET_DELAYS_SEC.length) {
+                return DATA_STALL_RESET_DELAYS_SEC[DATA_STALL_RESET_DELAYS_SEC.length - 1];
+            } else {
+                return DATA_STALL_RESET_DELAYS_SEC[count];
+            }
+        }
+    }
+
+    @VisibleForTesting
+    interface ValidationStatusCallback {
+        void onValidationStatus(int status);
     }
 
     public Vpn(Looper looper, Context context, INetworkManagementService netService, INetd netd,
@@ -1460,6 +1490,11 @@ public class Vpn {
 
     @GuardedBy("this")
     private void agentConnect() {
+        agentConnect(null /* validationCallback */);
+    }
+
+    @GuardedBy("this")
+    private void agentConnect(@Nullable ValidationStatusCallback validationCallback) {
         LinkProperties lp = makeLinkProperties();
 
         // VPN either provide a default route (IPv4 or IPv6 or both), or they are a split tunnel
@@ -1507,7 +1542,7 @@ public class Vpn {
         mNetworkAgent = mDeps.newNetworkAgent(mContext, mLooper, NETWORKTYPE /* logtag */,
                 mNetworkCapabilities, lp,
                 new NetworkScore.Builder().setLegacyInt(VPN_DEFAULT_SCORE).build(),
-                networkAgentConfig, mNetworkProvider);
+                networkAgentConfig, mNetworkProvider, validationCallback);
         final long token = Binder.clearCallingIdentity();
         try {
             mNetworkAgent.register();
@@ -2723,7 +2758,7 @@ public class Vpn {
 
         @Nullable private ScheduledFuture<?> mScheduledHandleNetworkLostFuture;
         @Nullable private ScheduledFuture<?> mScheduledHandleRetryIkeSessionFuture;
-
+        @Nullable private ScheduledFuture<?> mScheduledHandleDataStallFuture;
         /** Signal to ensure shutdown is honored even if a new Network is connected. */
         private boolean mIsRunning = true;
 
@@ -2749,6 +2784,14 @@ public class Vpn {
         // mMobikeEnabled can only be updated after IKE AUTH is finished.
         private boolean mMobikeEnabled = false;
 
+        /**
+         * The number of attempts to reset the IKE session since the last successful connection.
+         *
+         * <p>This variable controls the retry delay, and is reset when the VPN pass network
+         * validation.
+         */
+        private int mDataStallRetryCount = 0;
+
         /**
          * The number of attempts since the last successful connection.
          *
@@ -2931,7 +2974,7 @@ public class Vpn {
                         if (isSettingsVpnLocked()) {
                             prepareStatusIntent();
                         }
-                        agentConnect();
+                        agentConnect(this::onValidationStatus);
                         return; // Link properties are already sent.
                     } else {
                         // Underlying networks also set in agentConnect()
@@ -3200,18 +3243,52 @@ public class Vpn {
                     // Ignore stale runner.
                     if (mVpnRunner != Vpn.IkeV2VpnRunner.this) return;
 
-                    // Handle the report only for current VPN network.
+                    // Handle the report only for current VPN network. If data stall is already
+                    // reported, ignoring the other reports. It means that the stall is not
+                    // recovered by MOBIKE and should be on the way to reset the ike session.
                     if (mNetworkAgent != null
-                            && mNetworkAgent.getNetwork().equals(report.getNetwork())) {
+                            && mNetworkAgent.getNetwork().equals(report.getNetwork())
+                            && !mDataStallSuspected) {
                         Log.d(TAG, "Data stall suspected");
 
                         // Trigger MOBIKE.
                         maybeMigrateIkeSession(mActiveNetwork);
+                        mDataStallSuspected = true;
                     }
                 }
             }
         }
 
+        public void onValidationStatus(int status) {
+            if (status == NetworkAgent.VALIDATION_STATUS_VALID) {
+                // No data stall now. Reset it.
+                mExecutor.execute(() -> {
+                    mDataStallSuspected = false;
+                    mDataStallRetryCount = 0;
+                    if (mScheduledHandleDataStallFuture != null) {
+                        Log.d(TAG, "Recovered from stall. Cancel pending reset action.");
+                        mScheduledHandleDataStallFuture.cancel(false /* mayInterruptIfRunning */);
+                        mScheduledHandleDataStallFuture = null;
+                    }
+                });
+            } else {
+                // Skip other invalid status if the scheduled recovery exists.
+                if (mScheduledHandleDataStallFuture != null) return;
+
+                mScheduledHandleDataStallFuture = mExecutor.schedule(() -> {
+                    if (mDataStallSuspected) {
+                        Log.d(TAG, "Reset session to recover stalled network");
+                        // This will reset old state if it exists.
+                        startIkeSession(mActiveNetwork);
+                    }
+
+                    // Reset mScheduledHandleDataStallFuture since it's already run on executor
+                    // thread.
+                    mScheduledHandleDataStallFuture = null;
+                }, mDeps.getDataStallResetSessionSeconds(mDataStallRetryCount++), TimeUnit.SECONDS);
+            }
+        }
+
         /**
          * Handles loss of the default underlying network
          *
@@ -4339,6 +4416,7 @@ public class Vpn {
     // un-finalized.
     @VisibleForTesting
     public static class VpnNetworkAgentWrapper extends NetworkAgent {
+        private final ValidationStatusCallback mCallback;
         /** Create an VpnNetworkAgentWrapper */
         public VpnNetworkAgentWrapper(
                 @NonNull Context context,
@@ -4348,8 +4426,10 @@ public class Vpn {
                 @NonNull LinkProperties lp,
                 @NonNull NetworkScore score,
                 @NonNull NetworkAgentConfig config,
-                @Nullable NetworkProvider provider) {
+                @Nullable NetworkProvider provider,
+                @Nullable ValidationStatusCallback callback) {
             super(context, looper, logTag, nc, lp, score, config, provider);
+            mCallback = callback;
         }
 
         /** Update the LinkProperties */
@@ -4371,6 +4451,13 @@ public class Vpn {
         public void onNetworkUnwanted() {
             // We are user controlled, not driven by NetworkRequest.
         }
+
+        @Override
+        public void onValidationStatus(int status, Uri redirectUri) {
+            if (mCallback != null) {
+                mCallback.onValidationStatus(status);
+            }
+        }
     }
 
     /**