gmscompat: synthesize GSF package presence when GmsCore is installed

core/java/android/app/ApplicationPackageManager.java

@@ -141,6 +141,7 @@
 
 import com.android.internal.annotations.GuardedBy;
 import com.android.internal.annotations.VisibleForTesting;
+import com.android.internal.gmscompat.GsfPresenceCompat;
 import com.android.internal.gmscompat.sysservice.GmcPackageManager;
 import com.android.internal.os.ApplicationSharedMemory;
 import com.android.internal.os.SomeArgs;
@@ -265,15 +266,20 @@ public PackageInfo getPackageInfo(VersionedPackage versionedPackage, int flags)
     public PackageInfo getPackageInfo(VersionedPackage versionedPackage, PackageInfoFlags flags)
             throws NameNotFoundException {
         final int userId = getUserId();
+        final long updatedFlags = updateFlagsForPackage(flags.getValue(), userId);
         try {
-            PackageInfo pi = mPM.getPackageInfoVersioned(versionedPackage,
-                    updateFlagsForPackage(flags.getValue(), userId), userId);
+            PackageInfo pi = mPM.getPackageInfoVersioned(versionedPackage, updatedFlags, userId);
             if (pi != null) {
                 return pi;
             }
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
+        PackageInfo synth = GsfPresenceCompat.maybeSynthesizePackageInfo(
+                versionedPackage.getPackageName(), updatedFlags, userId);
+        if (synth != null) {
+            return synth;
+        }
         throw new NameNotFoundException(versionedPackage.toString());
     }
 
@@ -286,12 +292,14 @@ public PackageInfo getPackageInfoAsUser(String packageName, int flags, int userI
     @Override
     public PackageInfo getPackageInfoAsUser(String packageName, PackageInfoFlags flags, int userId)
             throws NameNotFoundException {
-        PackageInfo pi =
-                getPackageInfoAsUserCached(
-                        packageName,
-                        updateFlagsForPackage(flags.getValue(), userId),
-                        userId);
+        final long updatedFlags = updateFlagsForPackage(flags.getValue(), userId);
+        PackageInfo pi = getPackageInfoAsUserCached(packageName, updatedFlags, userId);
         if (pi == null) {
+            PackageInfo synth = GsfPresenceCompat.maybeSynthesizePackageInfo(
+                    packageName, updatedFlags, userId);
+            if (synth != null) {
+                return synth;
+            }
             throw new NameNotFoundException(packageName);
         }
         GmcPackageManager.maybeAdjustPackageInfo(pi);
@@ -549,11 +557,14 @@ public ApplicationInfo getApplicationInfoAsUser(String packageName, int flags, i
     @Override
     public ApplicationInfo getApplicationInfoAsUser(String packageName, ApplicationInfoFlags flags,
             int userId) throws NameNotFoundException {
-        ApplicationInfo ai = getApplicationInfoAsUserCached(
-                        packageName,
-                        updateFlagsForApplication(flags.getValue(), userId),
-                        userId);
+        final long updatedFlags = updateFlagsForApplication(flags.getValue(), userId);
+        ApplicationInfo ai = getApplicationInfoAsUserCached(packageName, updatedFlags, userId);
         if (ai == null) {
+            ApplicationInfo synth = GsfPresenceCompat.maybeSynthesizeApplicationInfo(
+                    packageName, updatedFlags, userId);
+            if (synth != null) {
+                return synth;
+            }
             throw new NameNotFoundException(packageName);
         }
 

core/java/com/android/internal/gmscompat/GsfPresenceCompat.java

@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2026 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.internal.gmscompat;
+
+import android.annotation.Nullable;
+import android.app.ActivityThread;
+import android.content.pm.ApplicationInfo;
+import android.content.pm.IPackageManager;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+import android.ext.PackageId;
+import android.os.RemoteException;
+import android.util.Log;
+
+/**
+ * Synthesizes {@link PackageId#GSF_NAME} package presence for third-party apps when
+ * Play Services is installed but GSF itself is absent (fresh GrapheneOS installs).
+ * <p>
+ * Some apps (e.g. Hikvision Hik-Connect / Guarding Vision) gate FCM on
+ * {@code getPackageInfo("com.google.android.gsf")} even though FCM works through GmsCore.
+ * This helper answers that presence probe only; it does not allow installing real GSF.
+ * <p>
+ * The GmsCore presence check is subject to the caller's package visibility. That matches
+ * when FCM is viable for the app.
+ *
+ * @hide
+ */
+public final class GsfPresenceCompat {
+    private static final String TAG = "GsfPresenceCompat";
+
+    private GsfPresenceCompat() {}
+
+    /**
+     * @param flags unused; kept so call sites can pass the original query flags unchanged
+     * @return a synthetic {@link PackageInfo} for GSF, or null if this request should
+     *         still throw {@link PackageManager.NameNotFoundException}
+     */
+    @Nullable
+    public static PackageInfo maybeSynthesizePackageInfo(String packageName, long flags,
+            int userId) {
+        if (!PackageId.GSF_NAME.equals(packageName)) {
+            return null;
+        }
+        if (!isVerifiedGmsCoreInstalled(userId)) {
+            return null;
+        }
+        // Minimal presence-only object. Do not copy GmsCore fields (version, signatures,
+        // sharedUserId, etc.) under the GSF name.
+        PackageInfo pi = new PackageInfo();
+        pi.packageName = PackageId.GSF_NAME;
+        pi.applicationInfo = synthesizeApplicationInfo();
+        Log.d(TAG, "synthesized PackageInfo for " + PackageId.GSF_NAME
+                + " (GmsCore present, userId=" + userId + ")");
+        return pi;
+    }
+
+    /**
+     * @param flags unused; kept so call sites can pass the original query flags unchanged
+     * @return a synthetic {@link ApplicationInfo} for GSF, or null if this request should
+     *         still throw {@link PackageManager.NameNotFoundException}
+     */
+    @Nullable
+    public static ApplicationInfo maybeSynthesizeApplicationInfo(String packageName, long flags,
+            int userId) {
+        if (!PackageId.GSF_NAME.equals(packageName)) {
+            return null;
+        }
+        if (!isVerifiedGmsCoreInstalled(userId)) {
+            return null;
+        }
+        ApplicationInfo ai = synthesizeApplicationInfo();
+        Log.d(TAG, "synthesized ApplicationInfo for " + PackageId.GSF_NAME
+                + " (GmsCore present, userId=" + userId + ")");
+        return ai;
+    }
+
+    private static ApplicationInfo synthesizeApplicationInfo() {
+        ApplicationInfo ai = new ApplicationInfo();
+        ai.packageName = PackageId.GSF_NAME;
+        ai.enabled = true;
+        return ai;
+    }
+
+    /**
+     * True if verified Play Services is installed and visible to the caller for {@code userId}.
+     */
+    private static boolean isVerifiedGmsCoreInstalled(int userId) {
+        IPackageManager pm = ActivityThread.getPackageManager();
+        ApplicationInfo ai;
+        try {
+            ai = pm.getApplicationInfo(PackageId.GMS_CORE_NAME, /* flags */ 0L, userId);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+        if (ai == null || !ai.enabled) {
+            return false;
+        }
+        // Reject lookalikes (wrong signing key / no GrapheneOS PackageId assignment).
+        return ai.ext().getPackageId() == PackageId.GMS_CORE;
+    }
+}