diff --git a/framework/Android.bp b/framework/Android.bp
index 7261178..a1c6a15 100644
--- a/framework/Android.bp
+++ b/framework/Android.bp
@@ -75,6 +75,7 @@
             // the module builds against API (the parcelable declarations exist in framework.aidl)
             "frameworks/base/core/java", // For framework parcelables
             "frameworks/native/aidl/binder", // For PersistableBundle.aidl
+            "packages/modules/Connectivity/Tethering/common/TetheringLib/src",
         ],
     },
     stub_only_libs: [
@@ -335,6 +336,7 @@
     aidl: {
         include_dirs: [
             "packages/modules/Connectivity/framework/aidl-export",
+            "packages/modules/Connectivity/Tethering/common/TetheringLib/src",
             "frameworks/native/aidl/binder", // For PersistableBundle.aidl
         ],
     },
diff --git a/framework/src/android/net/CaptivePortal.java b/framework/src/android/net/CaptivePortal.java
index 4a7b601..4c534f3 100644
--- a/framework/src/android/net/CaptivePortal.java
+++ b/framework/src/android/net/CaptivePortal.java
@@ -18,10 +18,19 @@
 import android.annotation.NonNull;
 import android.annotation.RequiresPermission;
 import android.annotation.SystemApi;
+import android.annotation.TargetApi;
+import android.os.Binder;
+import android.os.Build;
 import android.os.IBinder;
+import android.os.OutcomeReceiver;
 import android.os.Parcel;
 import android.os.Parcelable;
 import android.os.RemoteException;
+import android.os.ServiceSpecificException;
+import android.system.OsConstants;
+
+import java.util.Objects;
+import java.util.concurrent.Executor;
 
 /**
  * A class allowing apps handling the {@link ConnectivityManager#ACTION_CAPTIVE_PORTAL_SIGN_IN}
@@ -69,6 +78,15 @@
     @SystemApi
     public static final int APP_REQUEST_REEVALUATION_REQUIRED = APP_REQUEST_BASE + 0;
 
+    /**
+     * Binder object used for tracking the lifetime of the process, so CS can perform cleanup if
+     * the CaptivePortal app dies. This binder is not parcelled as part of this object. It is
+     * created in the client process and sent to the server by setDelegateUid so that the server
+     * can use it to register a death recipient.
+     *
+     */
+    private final Binder mLifetimeBinder = new Binder();
+
     private final IBinder mBinder;
 
     /** @hide */
@@ -167,4 +185,56 @@
     @SystemApi
     public void logEvent(int eventId, @NonNull String packageName) {
     }
+
+    /**
+     * Sets the UID of the app that is allowed to perform network traffic for captive
+     * portal login.
+     *
+     * This app will be allowed to communicate directly on the captive
+     * portal by binding to the {@link android.net.Network} extra passed in the
+     * ACTION_CAPTIVE_PORTAL_SIGN_IN broadcast that contained this object.
+     *
+     * Communication will bypass network access restrictions such as VPNs and
+     * Private DNS settings, so the delegated UID must be trusted to ensure that only
+     * traffic intended for captive portal login binds to that network.
+     *
+     * By default, no UID is delegated. The delegation can be cleared by calling
+     * this method again with {@link android.os.Process.INVALID_UID}. Only one UID can
+     * be delegated at any given time.
+     *
+     * The operation is asynchronous. The uid is only guaranteed to have access when
+     * the provided OutcomeReceiver is called.
+     *
+     * @hide
+     */
+    @RequiresPermission(NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK)
+    // OutcomeReceiver is not available on R, but the mainline version of this
+    // class is only available on S+.
+    @TargetApi(Build.VERSION_CODES.S)
+    public void setDelegateUid(int uid, @NonNull Executor executor,
+            @NonNull final OutcomeReceiver<Void, ServiceSpecificException> receiver) {
+        Objects.requireNonNull(executor);
+        Objects.requireNonNull(receiver);
+        try {
+            ICaptivePortal.Stub.asInterface(mBinder).setDelegateUid(
+                    uid,
+                    mLifetimeBinder,
+                    new IIntResultListener.Stub() {
+                        @Override
+                        public void onResult(int resultCode) {
+                            if (resultCode != 0) {
+                                final String msg = "Fail to set the delegate UID " + uid
+                                        + ", error: " + OsConstants.errnoName(resultCode);
+                                executor.execute(() -> {
+                                    receiver.onError(new ServiceSpecificException(resultCode, msg));
+                                });
+                            } else {
+                                executor.execute(() -> receiver.onResult(null));
+                            }
+                        }
+                    });
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
 }
diff --git a/framework/src/android/net/ICaptivePortal.aidl b/framework/src/android/net/ICaptivePortal.aidl
index e35f8d4..5cbb428 100644
--- a/framework/src/android/net/ICaptivePortal.aidl
+++ b/framework/src/android/net/ICaptivePortal.aidl
@@ -16,6 +16,9 @@
 
 package android.net;
 
+import android.net.IIntResultListener;
+import android.os.IBinder;
+
 /**
  * Interface to inform NetworkMonitor of decisions of app handling captive portal.
  * @hide
@@ -23,4 +26,5 @@
 oneway interface ICaptivePortal {
     void appRequest(int request);
     void appResponse(int response);
+    void setDelegateUid(int uid, IBinder binder, IIntResultListener listener);
 }
diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index f3b97bc..4c0d7b3 100644
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -121,6 +121,9 @@
 import static android.net.connectivity.ConnectivityCompatChanges.NETWORK_BLOCKED_WITHOUT_INTERNET_PERMISSION;
 import static android.os.Process.INVALID_UID;
 import static android.os.Process.VPN_UID;
+import static android.system.OsConstants.ENOENT;
+import static android.system.OsConstants.ENOTCONN;
+import static android.system.OsConstants.EOPNOTSUPP;
 import static android.system.OsConstants.ETH_P_ALL;
 import static android.system.OsConstants.IPPROTO_TCP;
 import static android.system.OsConstants.IPPROTO_UDP;
@@ -195,6 +198,7 @@
 import android.net.IConnectivityDiagnosticsCallback;
 import android.net.IConnectivityManager;
 import android.net.IDnsResolver;
+import android.net.IIntResultListener;
 import android.net.INetd;
 import android.net.INetworkActivityListener;
 import android.net.INetworkAgent;
@@ -6340,8 +6344,20 @@
         }
     }
 
-    private class CaptivePortalImpl extends ICaptivePortal.Stub {
+    public class CaptivePortalImpl extends ICaptivePortal.Stub implements IBinder.DeathRecipient {
         private final Network mNetwork;
+        // Binder object to track the lifetime of the setDelegateUid caller for cleanup purposes.
+        //
+        // Note that in theory it can happen that there are multiple callers for a given
+        // object. For example, the app that receives the CaptivePortal object from the Intent
+        // fired by startCaptivePortalAppInternal could send the object to another process, or
+        // clone it. Only the first of these objects that calls setDelegateUid will properly
+        // register a death recipient. Calls from the other objects will work, but only the
+        // first object's death will cause the death recipient to fire.
+        // TODO: track all callers by callerBinder instead of CaptivePortalImpl, store callerBinder
+        // in a Set. When the death recipient fires, we can remove the callingBinder from the set,
+        // and when the set is empty, we can clear the delegated UID.
+        private IBinder mDelegateUidCaller;
 
         private CaptivePortalImpl(Network network) {
             mNetwork = network;
@@ -6381,6 +6397,55 @@
             }
         }
 
+        private int handleSetDelegateUid(int uid, @NonNull final IBinder callerBinder) {
+            if (mDelegateUidCaller == null) {
+                mDelegateUidCaller = callerBinder;
+                try {
+                    // While technically unnecessary, it is safe to register a DeathRecipient for
+                    // a cleanup operation (where uid = INVALID_UID).
+                    mDelegateUidCaller.linkToDeath(this, 0);
+                } catch (RemoteException e) {
+                    // remote has died, return early.
+                    return ENOTCONN;
+                }
+            }
+
+            final NetworkAgentInfo nai = getNetworkAgentInfoForNetwork(mNetwork);
+            if (nai == null) return ENOENT; // network does not exist anymore.
+            if (nai.isDestroyed()) return ENOENT; // network has already been destroyed.
+
+            // TODO: consider allowing the uid to bypass VPN on all networks before V.
+            if (!mDeps.isAtLeastV()) return EOPNOTSUPP;
+
+            // Check whether there has already been a delegate UID configured, if so, perform
+            // cleanup and disallow bypassing VPN for that UID if no other caller is delegating
+            // this UID.
+            // TODO: consider using exceptions instead of errnos.
+            final int errno = nai.removeCaptivePortalDelegateUid(this);
+            if (errno != 0) return errno;
+
+            // If uid == INVALID_UID, we are done.
+            if (uid == INVALID_UID) return 0;
+            return nai.setCaptivePortalDelegateUid(this, uid);
+        }
+
+        @Override
+        public void setDelegateUid(int uid, @NonNull final IBinder callerBinder,
+                @NonNull final IIntResultListener listener) {
+            Objects.requireNonNull(callerBinder);
+            Objects.requireNonNull(listener);
+            enforceAnyPermissionOf(mContext, NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK);
+
+            mHandler.post(() -> {
+                final int errno = handleSetDelegateUid(uid, callerBinder);
+                try {
+                    listener.onResult(errno);
+                } catch (RemoteException e) {
+                    // remote has died, nothing to do.
+                }
+            });
+        }
+
         @Nullable
         private NetworkMonitorManager getNetworkMonitorManager(final Network network) {
             // getNetworkAgentInfoForNetwork is thread-safe
@@ -6390,6 +6455,13 @@
             // nai.networkMonitor() is thread-safe
             return nai.networkMonitor();
         }
+
+        @Override
+        public void binderDied() {
+            // Cleanup invalid UID and restore the VPN bypass rule. Because mDelegateUidCaller is
+            // never reset, it cannot be null in this context.
+            mHandler.post(() -> handleSetDelegateUid(INVALID_UID, mDelegateUidCaller));
+        }
     }
 
     public boolean avoidBadWifi() {
diff --git a/service/src/com/android/server/connectivity/NetworkAgentInfo.java b/service/src/com/android/server/connectivity/NetworkAgentInfo.java
index 94b655f..2b00386 100644
--- a/service/src/com/android/server/connectivity/NetworkAgentInfo.java
+++ b/service/src/com/android/server/connectivity/NetworkAgentInfo.java
@@ -25,6 +25,9 @@
 import static android.net.NetworkCapabilities.TRANSPORT_TEST;
 import static android.net.NetworkCapabilities.TRANSPORT_WIFI;
 import static android.net.NetworkCapabilities.transportNamesOf;
+import static android.system.OsConstants.EIO;
+import static android.system.OsConstants.EEXIST;
+import static android.system.OsConstants.ENOENT;
 
 import android.annotation.NonNull;
 import android.annotation.Nullable;
@@ -57,9 +60,11 @@
 import android.os.Handler;
 import android.os.IBinder;
 import android.os.RemoteException;
+import android.os.ServiceSpecificException;
 import android.os.SystemClock;
 import android.telephony.data.EpsBearerQosSessionAttributes;
 import android.telephony.data.NrQosSessionAttributes;
+import android.util.ArrayMap;
 import android.util.ArraySet;
 import android.util.Log;
 import android.util.Pair;
@@ -70,6 +75,7 @@
 import com.android.internal.util.WakeupMessage;
 import com.android.net.module.util.HandlerUtils;
 import com.android.server.ConnectivityService;
+import com.android.server.ConnectivityService.CaptivePortalImpl;
 
 import java.io.PrintWriter;
 import java.net.Inet4Address;
@@ -574,6 +580,10 @@
     // For fast lookups. Indexes into mInactivityTimers by request ID.
     private final SparseArray<InactivityTimer> mInactivityTimerForRequest = new SparseArray<>();
 
+    // Map of delegated UIDs used to bypass VPN and its captive portal app caller.
+    private final ArrayMap<CaptivePortalImpl, Integer> mCaptivePortalDelegateUids =
+            new ArrayMap<>();
+
     // Inactivity expiry timer. Armed whenever mInactivityTimers is non-empty, regardless of
     // whether the network is inactive or not. Always set to the expiry of the mInactivityTimers
     // that expires last. When the timer fires, all inactivity state is cleared, and if the network
@@ -626,6 +636,7 @@
     private final Context mContext;
     private final Handler mHandler;
     private final QosCallbackTracker mQosCallbackTracker;
+    private final INetd mNetd;
 
     private final long mCreationTime;
 
@@ -655,6 +666,7 @@
         mConnServiceDeps = deps;
         setScore(score); // uses members connService, networkCapabilities and networkAgentConfig
         clatd = new Nat464Xlat(this, netd, dnsResolver, deps);
+        mNetd = netd;
         mContext = context;
         mHandler = handler;
         this.factorySerialNumber = factorySerialNumber;
@@ -1549,6 +1561,52 @@
         }
     }
 
+    private int allowBypassVpnOnNetwork(boolean allow, int uid, int netId) {
+        try {
+            mNetd.networkAllowBypassVpnOnNetwork(allow, uid, netId);
+            return 0;
+        } catch (RemoteException e) {
+            // Netd has crashed, and this process is about to crash as well.
+            return EIO;
+        } catch (ServiceSpecificException e) {
+            return e.errorCode;
+        }
+    }
+
+    /**
+     * Set the delegate UID of the app that is allowed to perform network traffic for captive
+     * portal login, and configure the netd bypass rule with this delegated UID.
+     *
+     * @param caller the captive portal app to that delegated UID
+     * @param uid the delegated UID of the captive portal app.
+     * @return Return 0 if set the UID and VPN bypass rule successfully or bypass rule corresponding
+     *                to this UID already exists otherwise return errno.
+     */
+    public int setCaptivePortalDelegateUid(@NonNull final CaptivePortalImpl caller, int uid) {
+        final int errorCode = allowBypassVpnOnNetwork(true /* allow */, uid, network.netId);
+        if (errorCode == 0 || errorCode == EEXIST) {
+            mCaptivePortalDelegateUids.put(caller, uid);
+        }
+        return errorCode == EEXIST ? 0 : errorCode;
+    }
+
+    /**
+     * Remove the delegate UID of the app that is allowed to perform network traffic for captive
+     * portal login, and remove the netd bypass rule if no other caller is delegating this UID.
+     *
+     * @param caller the captive portal app to that delegated UID.
+     * @return Return 0 if remove the UID and VPN bypass rule successfully or bypass rule
+     *                corresponding to this UID doesn't exist otherwise return errno.
+     */
+    public int removeCaptivePortalDelegateUid(@NonNull final CaptivePortalImpl caller) {
+        final Integer maybeDelegateUid = mCaptivePortalDelegateUids.remove(caller);
+        if (maybeDelegateUid == null) return 0;
+        if (mCaptivePortalDelegateUids.values().contains(maybeDelegateUid)) return 0;
+        final int errorCode =
+                allowBypassVpnOnNetwork(false /* allow */, maybeDelegateUid, network.netId);
+        return errorCode == ENOENT ? 0 : errorCode;
+    }
+
     private static boolean areAllowedUidsAcceptableFromNetworkAgent(
             @NonNull final NetworkCapabilities nc, final boolean hasAutomotiveFeature,
             @NonNull final ConnectivityService.Dependencies deps,
diff --git a/tests/common/java/android/net/CaptivePortalTest.java b/tests/common/java/android/net/CaptivePortalTest.java
index 15d3398..6655827 100644
--- a/tests/common/java/android/net/CaptivePortalTest.java
+++ b/tests/common/java/android/net/CaptivePortalTest.java
@@ -19,6 +19,7 @@
 import static org.junit.Assert.assertEquals;
 
 import android.os.Build;
+import android.os.IBinder;
 import android.os.RemoteException;
 
 import androidx.test.filters.SmallTest;
@@ -55,6 +56,10 @@
             mCode = request;
         }
 
+        @Override
+        public void setDelegateUid(int uid, IBinder binder, IIntResultListener listener) {
+        }
+
         // This is only @Override on R-
         public void logEvent(int eventId, String packageName) throws RemoteException {
             mCode = eventId;