diff --git a/service/src/com/android/server/NetIdManager.java b/service/src/com/android/server/NetIdManager.java
new file mode 100644
index 0000000..61925c8
--- /dev/null
+++ b/service/src/com/android/server/NetIdManager.java
@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2019 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;
+
+import android.annotation.NonNull;
+import android.net.ConnectivityManager;
+import android.util.SparseBooleanArray;
+
+import com.android.internal.annotations.GuardedBy;
+import com.android.internal.annotations.VisibleForTesting;
+
+/**
+ * Class used to reserve and release net IDs.
+ *
+ * <p>Instances of this class are thread-safe.
+ */
+public class NetIdManager {
+    // Sequence number for Networks; keep in sync with system/netd/NetworkController.cpp
+    public static final int MIN_NET_ID = 100; // some reserved marks
+    // Top IDs reserved by IpSecService
+    public static final int MAX_NET_ID = ConnectivityManager.getIpSecNetIdRange().getLower() - 1;
+
+    @GuardedBy("mNetIdInUse")
+    private final SparseBooleanArray mNetIdInUse = new SparseBooleanArray();
+
+    @GuardedBy("mNetIdInUse")
+    private int mLastNetId = MIN_NET_ID - 1;
+
+    private final int mMaxNetId;
+
+    public NetIdManager() {
+        this(MAX_NET_ID);
+    }
+
+    @VisibleForTesting
+    NetIdManager(int maxNetId) {
+        mMaxNetId = maxNetId;
+    }
+
+    /**
+     * Get the first netId that follows the provided lastId and is available.
+     */
+    private int getNextAvailableNetIdLocked(
+            int lastId, @NonNull SparseBooleanArray netIdInUse) {
+        int netId = lastId;
+        for (int i = MIN_NET_ID; i <= mMaxNetId; i++) {
+            netId = netId < mMaxNetId ? netId + 1 : MIN_NET_ID;
+            if (!netIdInUse.get(netId)) {
+                return netId;
+            }
+        }
+        throw new IllegalStateException("No free netIds");
+    }
+
+    /**
+     * Reserve a new ID for a network.
+     */
+    public int reserveNetId() {
+        synchronized (mNetIdInUse) {
+            mLastNetId = getNextAvailableNetIdLocked(mLastNetId, mNetIdInUse);
+            // Make sure NetID unused.  http://b/16815182
+            mNetIdInUse.put(mLastNetId, true);
+            return mLastNetId;
+        }
+    }
+
+    /**
+     * Clear a previously reserved ID for a network.
+     */
+    public void releaseNetId(int id) {
+        synchronized (mNetIdInUse) {
+            mNetIdInUse.delete(id);
+        }
+    }
+}
diff --git a/service/src/com/android/server/connectivity/ProfileNetworkPreferences.java b/service/src/com/android/server/connectivity/ProfileNetworkPreferences.java
new file mode 100644
index 0000000..dd2815d
--- /dev/null
+++ b/service/src/com/android/server/connectivity/ProfileNetworkPreferences.java
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2021 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.connectivity;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.net.NetworkCapabilities;
+import android.os.UserHandle;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * A data class containing all the per-profile network preferences.
+ *
+ * A given profile can only have one preference.
+ */
+public class ProfileNetworkPreferences {
+    /**
+     * A single preference, as it applies to a given user profile.
+     */
+    public static class Preference {
+        @NonNull public final UserHandle user;
+        // Capabilities are only null when sending an object to remove the setting for a user
+        @Nullable public final NetworkCapabilities capabilities;
+
+        public Preference(@NonNull final UserHandle user,
+                @Nullable final NetworkCapabilities capabilities) {
+            this.user = user;
+            this.capabilities = null == capabilities ? null : new NetworkCapabilities(capabilities);
+        }
+
+        /** toString */
+        public String toString() {
+            return "[ProfileNetworkPreference user=" + user + " caps=" + capabilities + "]";
+        }
+    }
+
+    @NonNull public final List<Preference> preferences;
+
+    public ProfileNetworkPreferences() {
+        preferences = Collections.EMPTY_LIST;
+    }
+
+    private ProfileNetworkPreferences(@NonNull final List<Preference> list) {
+        preferences = Collections.unmodifiableList(list);
+    }
+
+    /**
+     * Returns a new object consisting of this object plus the passed preference.
+     *
+     * If a preference already exists for the same user, it will be replaced by the passed
+     * preference. Passing a Preference object containing a null capabilities object is equivalent
+     * to (and indeed, implemented as) removing the preference for this user.
+     */
+    public ProfileNetworkPreferences plus(@NonNull final Preference pref) {
+        final ArrayList<Preference> newPrefs = new ArrayList<>();
+        for (final Preference existingPref : preferences) {
+            if (!existingPref.user.equals(pref.user)) {
+                newPrefs.add(existingPref);
+            }
+        }
+        if (null != pref.capabilities) {
+            newPrefs.add(pref);
+        }
+        return new ProfileNetworkPreferences(newPrefs);
+    }
+
+    public boolean isEmpty() {
+        return preferences.isEmpty();
+    }
+}