diff --git a/Tethering/src/android/net/ip/IpServer.java b/Tethering/src/android/net/ip/IpServer.java
index c065cd6..a8c8408 100644
--- a/Tethering/src/android/net/ip/IpServer.java
+++ b/Tethering/src/android/net/ip/IpServer.java
@@ -33,7 +33,6 @@
 
 import static com.android.net.module.util.Inet4AddressUtils.intToInet4AddressHTH;
 import static com.android.net.module.util.NetworkStackConstants.RFC7421_PREFIX_LENGTH;
-import static com.android.networkstack.tethering.TetheringConfiguration.USE_SYNC_SM;
 import static com.android.networkstack.tethering.UpstreamNetworkState.isVcnInterface;
 import static com.android.networkstack.tethering.util.PrefixUtils.asIpPrefix;
 import static com.android.networkstack.tethering.util.TetheringMessageBase.BASE_IPSERVER;
@@ -316,6 +315,7 @@
 
     private final TetheringMetrics mTetheringMetrics;
     private final Handler mHandler;
+    private final boolean mIsSyncSM;
 
     // TODO: Add a dependency object to pass the data members or variables from the tethering
     // object. It helps to reduce the arguments of the constructor.
@@ -325,7 +325,7 @@
             @Nullable LateSdk<RoutingCoordinatorManager> routingCoordinator, Callback callback,
             TetheringConfiguration config, PrivateAddressCoordinator addressCoordinator,
             TetheringMetrics tetheringMetrics, Dependencies deps) {
-        super(ifaceName, USE_SYNC_SM ? null : handler.getLooper());
+        super(ifaceName, config.isSyncSM() ? null : handler.getLooper());
         mHandler = handler;
         mLog = log.forSubComponent(ifaceName);
         mNetd = netd;
@@ -338,6 +338,7 @@
         mLinkProperties = new LinkProperties();
         mUsingLegacyDhcp = config.useLegacyDhcpServer();
         mP2pLeasesSubnetPrefixLength = config.getP2pLeasesSubnetPrefixLength();
+        mIsSyncSM = config.isSyncSM();
         mPrivateAddressCoordinator = addressCoordinator;
         mDeps = deps;
         mTetheringMetrics = tetheringMetrics;
@@ -515,7 +516,7 @@
 
         private void handleError() {
             mLastError = TETHER_ERROR_DHCPSERVER_ERROR;
-            if (USE_SYNC_SM) {
+            if (mIsSyncSM) {
                 sendMessage(CMD_SERVICE_FAILED_TO_START, TETHER_ERROR_DHCPSERVER_ERROR);
             } else {
                 sendMessageAtFrontOfQueueToAsyncSM(CMD_SERVICE_FAILED_TO_START,
@@ -1170,7 +1171,7 @@
                 // in previous versions of the mainline module.
                 // TODO : remove sendMessageAtFrontOfQueueToAsyncSM after migrating to the Sync
                 // StateMachine.
-                if (USE_SYNC_SM) {
+                if (mIsSyncSM) {
                     sendSelfMessageToSyncSM(CMD_SERVICE_FAILED_TO_START, mLastError);
                 } else {
                     sendMessageAtFrontOfQueueToAsyncSM(CMD_SERVICE_FAILED_TO_START, mLastError);
diff --git a/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java b/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
index 0678525..d09183a 100644
--- a/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
+++ b/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
@@ -132,15 +132,15 @@
 
     public static final String TETHER_FORCE_RANDOM_PREFIX_BASE_SELECTION =
             "tether_force_random_prefix_base_selection";
+
+    public static final String TETHER_ENABLE_SYNC_SM = "tether_enable_sync_sm";
+
     /**
      * Default value that used to periodic polls tether offload stats from tethering offload HAL
      * to make the data warnings work.
      */
     public static final int DEFAULT_TETHER_OFFLOAD_POLL_INTERVAL_MS = 5000;
 
-    /** A flag for using synchronous or asynchronous state machine. */
-    public static final boolean USE_SYNC_SM = false;
-
     public final String[] tetherableUsbRegexs;
     public final String[] tetherableWifiRegexs;
     public final String[] tetherableWigigRegexs;
@@ -174,6 +174,7 @@
 
     private final boolean mEnableWearTethering;
     private final boolean mRandomPrefixBase;
+    private final boolean mEnableSyncSm;
 
     private final int mUsbTetheringFunction;
     protected final ContentResolver mContentResolver;
@@ -292,6 +293,7 @@
         mEnableWearTethering = shouldEnableWearTethering(ctx);
 
         mRandomPrefixBase = mDeps.isFeatureEnabled(ctx, TETHER_FORCE_RANDOM_PREFIX_BASE_SELECTION);
+        mEnableSyncSm = mDeps.isFeatureEnabled(ctx, TETHER_ENABLE_SYNC_SM);
 
         configLog.log(toString());
     }
@@ -385,6 +387,10 @@
         return mRandomPrefixBase;
     }
 
+    public boolean isSyncSM() {
+        return mEnableSyncSm;
+    }
+
     /** Does the dumping.*/
     public void dump(PrintWriter pw) {
         pw.print("activeDataSubId: ");
@@ -438,6 +444,9 @@
 
         pw.print("mRandomPrefixBase: ");
         pw.println(mRandomPrefixBase);
+
+        pw.print("mEnableSyncSm: ");
+        pw.println(mEnableSyncSm);
     }
 
     /** Returns the string representation of this object.*/
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringConfigurationTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringConfigurationTest.java
index aa322dc..19c6e5a 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringConfigurationTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringConfigurationTest.java
@@ -754,4 +754,26 @@
                 new TetheringConfiguration(mMockContext, mLog, INVALID_SUBSCRIPTION_ID, mDeps);
         assertEquals(p2pLeasesSubnetPrefixLength, p2pCfg.getP2pLeasesSubnetPrefixLength());
     }
+
+    private void setTetherEnableSyncSMFlagEnabled(Boolean enabled) {
+        mDeps.setFeatureEnabled(TetheringConfiguration.TETHER_ENABLE_SYNC_SM, enabled);
+    }
+
+    private void assertEnableSyncSMIs(boolean value) {
+        assertEquals(value, new TetheringConfiguration(
+                mMockContext, mLog, INVALID_SUBSCRIPTION_ID, mDeps).isSyncSM());
+    }
+
+    @Test
+    public void testEnableSyncSMFlag() throws Exception {
+        // Test default disabled
+        setTetherEnableSyncSMFlagEnabled(null);
+        assertEnableSyncSMIs(false);
+
+        setTetherEnableSyncSMFlagEnabled(true);
+        assertEnableSyncSMIs(true);
+
+        setTetherEnableSyncSMFlagEnabled(false);
+        assertEnableSyncSMIs(false);
+    }
 }
diff --git a/framework-t/src/android/net/IIpSecService.aidl b/framework-t/src/android/net/IIpSecService.aidl
index 88ffd0e..f972ab9 100644
--- a/framework-t/src/android/net/IIpSecService.aidl
+++ b/framework-t/src/android/net/IIpSecService.aidl
@@ -22,6 +22,7 @@
 import android.net.IpSecUdpEncapResponse;
 import android.net.IpSecSpiResponse;
 import android.net.IpSecTransformResponse;
+import android.net.IpSecTransformState;
 import android.net.IpSecTunnelInterfaceResponse;
 import android.os.Bundle;
 import android.os.IBinder;
@@ -74,6 +75,8 @@
 
     void deleteTransform(int transformId);
 
+    IpSecTransformState getTransformState(int transformId);
+
     void applyTransportModeTransform(
             in ParcelFileDescriptor socket, int direction, int transformId);
 
diff --git a/framework-t/src/android/net/IpSecManager.java b/framework-t/src/android/net/IpSecManager.java
index 3afa6ef..3f74e1c 100644
--- a/framework-t/src/android/net/IpSecManager.java
+++ b/framework-t/src/android/net/IpSecManager.java
@@ -65,6 +65,13 @@
 public class IpSecManager {
     private static final String TAG = "IpSecManager";
 
+    // TODO : remove this class when udc-mainline-prod is abandoned and android.net.flags.Flags is
+    // available here
+    /** @hide */
+    public static class Flags {
+        static final String IPSEC_TRANSFORM_STATE = "com.android.net.flags.ipsec_transform_state";
+    }
+
     /**
      * Feature flag to declare the kernel support of updating IPsec SAs.
      *
@@ -1084,6 +1091,12 @@
         }
     }
 
+    /** @hide */
+    public IpSecTransformState getTransformState(int transformId)
+            throws IllegalStateException, RemoteException {
+        return mService.getTransformState(transformId);
+    }
+
     /**
      * Construct an instance of IpSecManager within an application context.
      *
diff --git a/framework-t/src/android/net/IpSecTransform.java b/framework-t/src/android/net/IpSecTransform.java
index c236b6c..0412a76 100644
--- a/framework-t/src/android/net/IpSecTransform.java
+++ b/framework-t/src/android/net/IpSecTransform.java
@@ -15,8 +15,11 @@
  */
 package android.net;
 
+import static android.net.IpSecManager.Flags.IPSEC_TRANSFORM_STATE;
 import static android.net.IpSecManager.INVALID_RESOURCE_ID;
 
+import android.annotation.CallbackExecutor;
+import android.annotation.FlaggedApi;
 import android.annotation.IntDef;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
@@ -26,6 +29,8 @@
 import android.content.Context;
 import android.content.pm.PackageManager;
 import android.os.Binder;
+import android.os.OutcomeReceiver;
+import android.os.RemoteException;
 import android.os.ServiceSpecificException;
 import android.util.Log;
 
@@ -38,6 +43,7 @@
 import java.lang.annotation.RetentionPolicy;
 import java.net.InetAddress;
 import java.util.Objects;
+import java.util.concurrent.Executor;
 
 /**
  * This class represents a transform, which roughly corresponds to an IPsec Security Association.
@@ -201,6 +207,44 @@
     }
 
     /**
+     * Retrieve the current state of this IpSecTransform.
+     *
+     * @param executor The {@link Executor} on which to call the supplied callback.
+     * @param callback Callback that's called after the transform state is ready or when an error
+     *     occurs.
+     * @see IpSecTransformState
+     * @hide
+     */
+    @FlaggedApi(IPSEC_TRANSFORM_STATE)
+    public void getIpSecTransformState(
+            @CallbackExecutor @NonNull Executor executor,
+            @NonNull OutcomeReceiver<IpSecTransformState, RuntimeException> callback) {
+        Objects.requireNonNull(executor);
+        Objects.requireNonNull(callback);
+
+        // TODO: Consider adding check to prevent DDoS attack.
+
+        try {
+            final IpSecTransformState ipSecTransformState =
+                    getIpSecManager(mContext).getTransformState(mResourceId);
+            executor.execute(
+                    () -> {
+                        callback.onResult(ipSecTransformState);
+                    });
+        } catch (IllegalStateException e) {
+            executor.execute(
+                    () -> {
+                        callback.onError(e);
+                    });
+        } catch (RemoteException e) {
+            executor.execute(
+                    () -> {
+                        callback.onError(e.rethrowFromSystemServer());
+                    });
+        }
+    }
+
+    /**
      * A callback class to provide status information regarding a NAT-T keepalive session
      *
      * <p>Use this callback to receive status information regarding a NAT-T keepalive session
diff --git a/framework-t/src/android/net/IpSecTransformState.aidl b/framework-t/src/android/net/IpSecTransformState.aidl
new file mode 100644
index 0000000..69cce28
--- /dev/null
+++ b/framework-t/src/android/net/IpSecTransformState.aidl
@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) 2023 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 android.net;
+
+/** @hide */
+parcelable IpSecTransformState;
\ No newline at end of file
diff --git a/framework-t/src/android/net/IpSecTransformState.java b/framework-t/src/android/net/IpSecTransformState.java
new file mode 100644
index 0000000..daebbc4
--- /dev/null
+++ b/framework-t/src/android/net/IpSecTransformState.java
@@ -0,0 +1,302 @@
+/*
+ * Copyright (C) 2023 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 android.net;
+
+import static android.net.IpSecManager.Flags.IPSEC_TRANSFORM_STATE;
+
+import static com.android.internal.annotations.VisibleForTesting.Visibility;
+
+import android.annotation.FlaggedApi;
+import android.annotation.NonNull;
+import android.os.Parcel;
+import android.os.Parcelable;
+
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.net.module.util.HexDump;
+
+import java.util.Objects;
+
+/**
+ * This class represents a snapshot of the state of an IpSecTransform
+ *
+ * <p>This class provides the current state of an IpSecTransform, enabling link metric analysis by
+ * the caller. Use cases include understanding transform usage, such as packet and byte counts, as
+ * well as observing out-of-order delivery by checking the bitmap. Additionally, callers can query
+ * IpSecTransformStates at two timestamps. By comparing the changes in packet counts and sequence
+ * numbers, callers can estimate IPsec data loss in the inbound direction.
+ *
+ * @hide
+ */
+@FlaggedApi(IPSEC_TRANSFORM_STATE)
+public final class IpSecTransformState implements Parcelable {
+    private final long mTimeStamp;
+    private final long mTxHighestSequenceNumber;
+    private final long mRxHighestSequenceNumber;
+    private final long mPacketCount;
+    private final long mByteCount;
+    private final byte[] mReplayBitmap;
+
+    private IpSecTransformState(
+            long timestamp,
+            long txHighestSequenceNumber,
+            long rxHighestSequenceNumber,
+            long packetCount,
+            long byteCount,
+            byte[] replayBitmap) {
+        mTimeStamp = timestamp;
+        mTxHighestSequenceNumber = txHighestSequenceNumber;
+        mRxHighestSequenceNumber = rxHighestSequenceNumber;
+        mPacketCount = packetCount;
+        mByteCount = byteCount;
+
+        Objects.requireNonNull(replayBitmap, "replayBitmap is null");
+        mReplayBitmap = replayBitmap.clone();
+
+        validate();
+    }
+
+    private void validate() {
+        Objects.requireNonNull(mReplayBitmap, "mReplayBitmap is null");
+    }
+
+    /**
+     * Deserializes a IpSecTransformState from a PersistableBundle.
+     *
+     * @hide
+     */
+    @VisibleForTesting(visibility = Visibility.PRIVATE)
+    public IpSecTransformState(@NonNull Parcel in) {
+        Objects.requireNonNull(in, "The input PersistableBundle is null");
+        mTimeStamp = in.readLong();
+        mTxHighestSequenceNumber = in.readLong();
+        mRxHighestSequenceNumber = in.readLong();
+        mPacketCount = in.readLong();
+        mByteCount = in.readLong();
+        mReplayBitmap = HexDump.hexStringToByteArray(in.readString());
+
+        validate();
+    }
+
+    // Parcelable methods
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(@NonNull Parcel out, int flags) {
+        out.writeLong(mTimeStamp);
+        out.writeLong(mTxHighestSequenceNumber);
+        out.writeLong(mRxHighestSequenceNumber);
+        out.writeLong(mPacketCount);
+        out.writeLong(mByteCount);
+        out.writeString(HexDump.toHexString(mReplayBitmap));
+    }
+
+    @NonNull
+    public static final Parcelable.Creator<IpSecTransformState> CREATOR =
+            new Parcelable.Creator<IpSecTransformState>() {
+                @NonNull
+                public IpSecTransformState createFromParcel(Parcel in) {
+                    return new IpSecTransformState(in);
+                }
+
+                @NonNull
+                public IpSecTransformState[] newArray(int size) {
+                    return new IpSecTransformState[size];
+                }
+            };
+
+    /**
+     * Retrieve the epoch timestamp (milliseconds) for when this state was created
+     *
+     * @see Builder#setTimestamp(long)
+     * @hide
+     */
+    public long getTimestamp() {
+        return mTimeStamp;
+    }
+
+    /**
+     * Retrieve the highest sequence number sent so far
+     *
+     * @see Builder#setTxHighestSequenceNumber(long)
+     * @hide
+     */
+    public long getTxHighestSequenceNumber() {
+        return mTxHighestSequenceNumber;
+    }
+
+    /**
+     * Retrieve the highest sequence number received so far
+     *
+     * @see Builder#setRxHighestSequenceNumber(long)
+     * @hide
+     */
+    public long getRxHighestSequenceNumber() {
+        return mRxHighestSequenceNumber;
+    }
+
+    /**
+     * Retrieve the number of packets received AND sent so far
+     *
+     * @see Builder#setPacketCount(long)
+     * @hide
+     */
+    public long getPacketCount() {
+        return mPacketCount;
+    }
+
+    /**
+     * Retrieve the number of bytes received AND sent so far
+     *
+     * @see Builder#setByteCount(long)
+     * @hide
+     */
+    public long getByteCount() {
+        return mByteCount;
+    }
+
+    /**
+     * Retrieve the replay bitmap
+     *
+     * <p>This bitmap represents a replay window, allowing the caller to observe out-of-order
+     * delivery. The last bit represents the highest sequence number received so far and bits for
+     * the received packets will be marked as true.
+     *
+     * <p>The size of a replay bitmap will never change over the lifetime of an IpSecTransform
+     *
+     * <p>The replay bitmap is solely useful for inbound IpSecTransforms. For outbound
+     * IpSecTransforms, all bits will be unchecked.
+     *
+     * @see Builder#setReplayBitmap(byte[])
+     * @hide
+     */
+    @NonNull
+    public byte[] getReplayBitmap() {
+        return mReplayBitmap.clone();
+    }
+
+    /**
+     * Builder class for testing purposes
+     *
+     * @hide
+     */
+    @FlaggedApi(IPSEC_TRANSFORM_STATE)
+    public static final class Builder {
+        private long mTimeStamp;
+        private long mTxHighestSequenceNumber;
+        private long mRxHighestSequenceNumber;
+        private long mPacketCount;
+        private long mByteCount;
+        private byte[] mReplayBitmap;
+
+        /** @hide */
+        public Builder() {
+            mTimeStamp = System.currentTimeMillis();
+        }
+
+        /**
+         * Set the epoch timestamp (milliseconds) for when this state was created
+         *
+         * @see IpSecTransformState#getTimestamp()
+         * @hide
+         */
+        @NonNull
+        public Builder setTimestamp(long timeStamp) {
+            mTimeStamp = timeStamp;
+            return this;
+        }
+
+        /**
+         * Set the highest sequence number sent so far
+         *
+         * @see IpSecTransformState#getTxHighestSequenceNumber()
+         * @hide
+         */
+        @NonNull
+        public Builder setTxHighestSequenceNumber(long seqNum) {
+            mTxHighestSequenceNumber = seqNum;
+            return this;
+        }
+
+        /**
+         * Set the highest sequence number received so far
+         *
+         * @see IpSecTransformState#getRxHighestSequenceNumber()
+         * @hide
+         */
+        @NonNull
+        public Builder setRxHighestSequenceNumber(long seqNum) {
+            mRxHighestSequenceNumber = seqNum;
+            return this;
+        }
+
+        /**
+         * Set the number of packets received AND sent so far
+         *
+         * @see IpSecTransformState#getPacketCount()
+         * @hide
+         */
+        @NonNull
+        public Builder setPacketCount(long packetCount) {
+            mPacketCount = packetCount;
+            return this;
+        }
+
+        /**
+         * Set the number of bytes received AND sent so far
+         *
+         * @see IpSecTransformState#getByteCount()
+         * @hide
+         */
+        @NonNull
+        public Builder setByteCount(long byteCount) {
+            mByteCount = byteCount;
+            return this;
+        }
+
+        /**
+         * Set the replay bitmap
+         *
+         * @see IpSecTransformState#getReplayBitmap()
+         * @hide
+         */
+        @NonNull
+        public Builder setReplayBitmap(@NonNull byte[] bitMap) {
+            mReplayBitmap = bitMap.clone();
+            return this;
+        }
+
+        /**
+         * Build and validate the IpSecTransformState
+         *
+         * @return an immutable IpSecTransformState instance
+         * @hide
+         */
+        @NonNull
+        public IpSecTransformState build() {
+            return new IpSecTransformState(
+                    mTimeStamp,
+                    mTxHighestSequenceNumber,
+                    mRxHighestSequenceNumber,
+                    mPacketCount,
+                    mByteCount,
+                    mReplayBitmap);
+        }
+    }
+}
diff --git a/service-t/src/com/android/server/IpSecService.java b/service-t/src/com/android/server/IpSecService.java
index a884840..ea91e64 100644
--- a/service-t/src/com/android/server/IpSecService.java
+++ b/service-t/src/com/android/server/IpSecService.java
@@ -42,6 +42,7 @@
 import android.net.IpSecSpiResponse;
 import android.net.IpSecTransform;
 import android.net.IpSecTransformResponse;
+import android.net.IpSecTransformState;
 import android.net.IpSecTunnelInterfaceResponse;
 import android.net.IpSecUdpEncapResponse;
 import android.net.LinkAddress;
@@ -70,6 +71,7 @@
 import com.android.net.module.util.BinderUtils;
 import com.android.net.module.util.NetdUtils;
 import com.android.net.module.util.PermissionUtils;
+import com.android.net.module.util.netlink.xfrm.XfrmNetlinkNewSaMessage;
 
 import libcore.io.IoUtils;
 
@@ -109,6 +111,7 @@
     @VisibleForTesting static final int MAX_PORT_BIND_ATTEMPTS = 10;
 
     private final INetd mNetd;
+    private final IpSecXfrmController mIpSecXfrmCtrl;
 
     static {
         try {
@@ -152,6 +155,11 @@
             }
             return netd;
         }
+
+        /** Get a instance of IpSecXfrmController */
+        public IpSecXfrmController getIpSecXfrmController() {
+            return new IpSecXfrmController();
+        }
     }
 
     final UidFdTagger mUidFdTagger;
@@ -1111,6 +1119,7 @@
         mContext = context;
         mDeps = Objects.requireNonNull(deps, "Missing dependencies.");
         mUidFdTagger = uidFdTagger;
+        mIpSecXfrmCtrl = mDeps.getIpSecXfrmController();
         try {
             mNetd = mDeps.getNetdInstance(mContext);
         } catch (RemoteException e) {
@@ -1862,6 +1871,48 @@
         releaseResource(userRecord.mTransformRecords, resourceId);
     }
 
+    @Override
+    public synchronized IpSecTransformState getTransformState(int transformId)
+            throws IllegalStateException, RemoteException {
+        mContext.enforceCallingOrSelfPermission(
+                android.Manifest.permission.ACCESS_NETWORK_STATE, "IpsecService#getTransformState");
+
+        UserRecord userRecord = mUserResourceTracker.getUserRecord(Binder.getCallingUid());
+        TransformRecord transformInfo =
+                userRecord.mTransformRecords.getResourceOrThrow(transformId);
+
+        final int spi = transformInfo.getSpiRecord().getSpi();
+        final InetAddress destAddress =
+                InetAddresses.parseNumericAddress(
+                        transformInfo.getConfig().getDestinationAddress());
+        Log.d(TAG, "getTransformState for spi " + spi + " destAddress " + destAddress);
+
+        // Make netlink call
+        final XfrmNetlinkNewSaMessage xfrmNewSaMsg;
+        try {
+            xfrmNewSaMsg = mIpSecXfrmCtrl.ipSecGetSa(destAddress, Integer.toUnsignedLong(spi));
+        } catch (ErrnoException | IOException e) {
+            Log.e(TAG, "getTransformState: failed to get IpSecTransformState" + e.toString());
+            throw new IllegalStateException("Failed to get IpSecTransformState", e);
+        }
+
+        // Keep the netlink socket open to save time for the next call. It is cheap to have a
+        // persistent netlink socket in the system server
+
+        if (xfrmNewSaMsg == null) {
+            Log.e(TAG, "getTransformState: failed to get IpSecTransformState xfrmNewSaMsg is null");
+            throw new IllegalStateException("Failed to get IpSecTransformState");
+        }
+
+        return new IpSecTransformState.Builder()
+                .setTxHighestSequenceNumber(xfrmNewSaMsg.getTxSequenceNumber())
+                .setRxHighestSequenceNumber(xfrmNewSaMsg.getRxSequenceNumber())
+                .setPacketCount(xfrmNewSaMsg.getPacketCount())
+                .setByteCount(xfrmNewSaMsg.getByteCount())
+                .setReplayBitmap(xfrmNewSaMsg.getBitmap())
+                .build();
+    }
+
     /**
      * Apply an active transport mode transform to a socket, which will apply the IPsec security
      * association as a correspondent policy to the provided socket
diff --git a/staticlibs/device/com/android/net/module/util/netlink/NetlinkMessage.java b/staticlibs/device/com/android/net/module/util/netlink/NetlinkMessage.java
index 111e0ba..781a04e 100644
--- a/staticlibs/device/com/android/net/module/util/netlink/NetlinkMessage.java
+++ b/staticlibs/device/com/android/net/module/util/netlink/NetlinkMessage.java
@@ -142,6 +142,7 @@
                 return (NetlinkMessage) RtNetlinkAddressMessage.parse(nlmsghdr, byteBuffer);
             case NetlinkConstants.RTM_NEWROUTE:
             case NetlinkConstants.RTM_DELROUTE:
+            case NetlinkConstants.RTM_GETROUTE:
                 return (NetlinkMessage) RtNetlinkRouteMessage.parse(nlmsghdr, byteBuffer);
             case NetlinkConstants.RTM_NEWNEIGH:
             case NetlinkConstants.RTM_DELNEIGH:
diff --git a/staticlibs/device/com/android/net/module/util/netlink/StructNlMsgHdr.java b/staticlibs/device/com/android/net/module/util/netlink/StructNlMsgHdr.java
index ff37639..5272366 100644
--- a/staticlibs/device/com/android/net/module/util/netlink/StructNlMsgHdr.java
+++ b/staticlibs/device/com/android/net/module/util/netlink/StructNlMsgHdr.java
@@ -71,13 +71,17 @@
             }
             sb.append("NLM_F_ECHO");
         }
-        if ((flags & NLM_F_ROOT) != 0) {
+        if ((flags & NLM_F_DUMP) == NLM_F_DUMP) {
+            if (sb.length() > 0) {
+                sb.append("|");
+            }
+            sb.append("NLM_F_DUMP");
+        } else if ((flags & NLM_F_ROOT) != 0) { // NLM_F_DUMP = NLM_F_ROOT | NLM_F_MATCH
             if (sb.length() > 0) {
                 sb.append("|");
             }
             sb.append("NLM_F_ROOT");
-        }
-        if ((flags & NLM_F_MATCH) != 0) {
+        } else if ((flags & NLM_F_MATCH) != 0) {
             if (sb.length() > 0) {
                 sb.append("|");
             }
diff --git a/staticlibs/tests/unit/Android.bp b/staticlibs/tests/unit/Android.bp
index 031e52f..0dfca57 100644
--- a/staticlibs/tests/unit/Android.bp
+++ b/staticlibs/tests/unit/Android.bp
@@ -33,7 +33,10 @@
         "//packages/modules/Connectivity/Tethering/tests:__subpackages__",
         "//packages/modules/NetworkStack/tests/integration",
     ],
-    lint: { strict_updatability_linting: true },
+    lint: {
+        strict_updatability_linting: true,
+        test: true
+    },
 }
 
 android_test {
diff --git a/staticlibs/tests/unit/src/com/android/net/module/util/netlink/StructNlMsgHdrTest.java b/staticlibs/tests/unit/src/com/android/net/module/util/netlink/StructNlMsgHdrTest.java
index b7f68c6..a0d8b8c 100644
--- a/staticlibs/tests/unit/src/com/android/net/module/util/netlink/StructNlMsgHdrTest.java
+++ b/staticlibs/tests/unit/src/com/android/net/module/util/netlink/StructNlMsgHdrTest.java
@@ -16,6 +16,7 @@
 
 package com.android.net.module.util.netlink;
 
+import static com.android.net.module.util.netlink.StructNlMsgHdr.NLM_F_DUMP;
 import static org.junit.Assert.fail;
 
 import android.system.OsConstants;
@@ -48,10 +49,14 @@
     public static final String TEST_NLMSG_PID_STR = "nlmsg_pid{5678}";
 
     private StructNlMsgHdr makeStructNlMsgHdr(short type) {
+        return makeStructNlMsgHdr(type, TEST_NLMSG_FLAGS);
+    }
+
+    private StructNlMsgHdr makeStructNlMsgHdr(short type, short flags) {
         final StructNlMsgHdr struct = new StructNlMsgHdr();
         struct.nlmsg_len = TEST_NLMSG_LEN;
         struct.nlmsg_type = type;
-        struct.nlmsg_flags = TEST_NLMSG_FLAGS;
+        struct.nlmsg_flags = flags;
         struct.nlmsg_seq = TEST_NLMSG_SEQ;
         struct.nlmsg_pid = TEST_NLMSG_PID;
         return struct;
@@ -62,6 +67,11 @@
         fail("\"" + actualValue + "\" does not contain \"" + expectedSubstring + "\"");
     }
 
+    private static void assertNotContains(String actualValue, String unexpectedSubstring) {
+        if (!actualValue.contains(unexpectedSubstring)) return;
+        fail("\"" + actualValue + "\" contains \"" + unexpectedSubstring + "\"");
+    }
+
     @Test
     public void testToString() {
         StructNlMsgHdr struct = makeStructNlMsgHdr(NetlinkConstants.RTM_NEWADDR);
@@ -99,4 +109,31 @@
         assertContains(s, TEST_NLMSG_PID_STR);
         assertContains(s, "nlmsg_type{20(SOCK_DIAG_BY_FAMILY)}");
     }
+
+    @Test
+    public void testToString_flags_dumpRequest() {
+        final short flags = StructNlMsgHdr.NLM_F_REQUEST | StructNlMsgHdr.NLM_F_DUMP;
+        StructNlMsgHdr struct = makeStructNlMsgHdr(NetlinkConstants.RTM_GETROUTE, flags);
+
+        String s = struct.toString(OsConstants.NETLINK_ROUTE);
+
+        assertContains(s, "RTM_GETROUTE");
+        assertContains(s, "NLM_F_REQUEST");
+        assertContains(s, "NLM_F_DUMP");
+        // NLM_F_DUMP = NLM_F_ROOT | NLM_F_MATCH;
+        assertNotContains(s, "NLM_F_MATCH");
+        assertNotContains(s, "NLM_F_ROOT");
+    }
+
+    @Test
+    public void testToString_flags_root() {
+        final short flags = StructNlMsgHdr.NLM_F_ROOT;
+        StructNlMsgHdr struct = makeStructNlMsgHdr(NetlinkConstants.RTM_GETROUTE, flags);
+
+        String s = struct.toString(OsConstants.NETLINK_ROUTE);
+
+        assertContains(s, "NLM_F_ROOT");
+        // NLM_F_DUMP = NLM_F_ROOT | NLM_F_MATCH;
+        assertNotContains(s, "NLM_F_DUMP");
+    }
 }
diff --git a/tests/unit/java/com/android/server/IpSecServiceParameterizedTest.java b/tests/unit/java/com/android/server/IpSecServiceParameterizedTest.java
index 1618a62..8037542 100644
--- a/tests/unit/java/com/android/server/IpSecServiceParameterizedTest.java
+++ b/tests/unit/java/com/android/server/IpSecServiceParameterizedTest.java
@@ -33,6 +33,7 @@
 import static org.junit.Assert.fail;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.ArgumentMatchers.anyLong;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.ArgumentMatchers.argThat;
 import static org.mockito.ArgumentMatchers.eq;
@@ -74,6 +75,7 @@
 
 import androidx.test.filters.SmallTest;
 
+import com.android.net.module.util.netlink.xfrm.XfrmNetlinkNewSaMessage;
 import com.android.server.IpSecService.TunnelInterfaceRecord;
 import com.android.testutils.DevSdkIgnoreRule;
 
@@ -85,6 +87,7 @@
 import org.junit.runners.Parameterized;
 
 import java.net.Inet4Address;
+import java.net.InetAddress;
 import java.net.Socket;
 import java.util.Arrays;
 import java.util.Collection;
@@ -149,6 +152,7 @@
         private Set<String> mAllowedPermissions = new ArraySet<>(Arrays.asList(
                 android.Manifest.permission.MANAGE_IPSEC_TUNNELS,
                 android.Manifest.permission.NETWORK_STACK,
+                android.Manifest.permission.ACCESS_NETWORK_STATE,
                 PERMISSION_MAINLINE_NETWORK_STACK));
 
         private void setAllowedPermissions(String... permissions) {
@@ -202,11 +206,13 @@
     private IpSecService.Dependencies makeDependencies() throws RemoteException {
         final IpSecService.Dependencies deps = mock(IpSecService.Dependencies.class);
         when(deps.getNetdInstance(mTestContext)).thenReturn(mMockNetd);
+        when(deps.getIpSecXfrmController()).thenReturn(mMockXfrmCtrl);
         return deps;
     }
 
     INetd mMockNetd;
     PackageManager mMockPkgMgr;
+    IpSecXfrmController mMockXfrmCtrl;
     IpSecService.Dependencies mDeps;
     IpSecService mIpSecService;
     Network fakeNetwork = new Network(0xAB);
@@ -235,6 +241,7 @@
     @Before
     public void setUp() throws Exception {
         mMockNetd = mock(INetd.class);
+        mMockXfrmCtrl = mock(IpSecXfrmController.class);
         mMockPkgMgr = mock(PackageManager.class);
         mDeps = makeDependencies();
         mIpSecService = new IpSecService(mTestContext, mDeps);
@@ -506,6 +513,32 @@
     }
 
     @Test
+    public void getTransformState() throws Exception {
+        XfrmNetlinkNewSaMessage mockXfrmNewSaMsg = mock(XfrmNetlinkNewSaMessage.class);
+        when(mockXfrmNewSaMsg.getBitmap()).thenReturn(new byte[512]);
+        when(mMockXfrmCtrl.ipSecGetSa(any(InetAddress.class), anyLong()))
+                .thenReturn(mockXfrmNewSaMsg);
+
+        // Create transform
+        IpSecConfig ipSecConfig = new IpSecConfig();
+        addDefaultSpisAndRemoteAddrToIpSecConfig(ipSecConfig);
+        addAuthAndCryptToIpSecConfig(ipSecConfig);
+
+        IpSecTransformResponse createTransformResp =
+                mIpSecService.createTransform(ipSecConfig, new Binder(), BLESSED_PACKAGE);
+        assertEquals(IpSecManager.Status.OK, createTransformResp.status);
+
+        // Get transform state
+        mIpSecService.getTransformState(createTransformResp.resourceId);
+
+        // Verifications
+        verify(mMockXfrmCtrl)
+                .ipSecGetSa(
+                        eq(InetAddresses.parseNumericAddress(mDestinationAddr)),
+                        eq(Integer.toUnsignedLong(TEST_SPI)));
+    }
+
+    @Test
     public void testReleaseOwnedSpi() throws Exception {
         IpSecConfig ipSecConfig = new IpSecConfig();
         addDefaultSpisAndRemoteAddrToIpSecConfig(ipSecConfig);
diff --git a/tests/unit/java/com/android/server/connectivity/VpnTest.java b/tests/unit/java/com/android/server/connectivity/VpnTest.java
index 46e9e45..c9cece0 100644
--- a/tests/unit/java/com/android/server/connectivity/VpnTest.java
+++ b/tests/unit/java/com/android/server/connectivity/VpnTest.java
@@ -2979,7 +2979,7 @@
                         null /* iface */, RTN_UNREACHABLE));
         assertEquals(expectedRoutes, lp.getRoutes());
 
-        verify(mMockNetworkAgent).unregister();
+        verify(mMockNetworkAgent, timeout(TEST_TIMEOUT_MS)).unregister();
     }
 
     @Test