Add permission to launch activities on VD

1. Added permission ACTIVITY_EMBEDDING which allows apps to launch
activities on virtual displays.
2. Allow owner of display to launch activities from same app without
permission check to owned display.
3. Added permission checks for launching on secondary displays to
more target task/stack resolution paths in ActivityStarter.

Bug: 63117330
Test: android.server.cts.ActivityManagerDisplayTests
Test: go/wm-smoke
Change-Id: If169a77fb56241e06f7de20168dc38c4b0a217f5
diff --git a/api/system-current.txt b/api/system-current.txt
index cc414bc..82ab6ea 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -22,6 +22,7 @@
     field public static final java.lang.String ACCESS_SURFACE_FLINGER = "android.permission.ACCESS_SURFACE_FLINGER";
     field public static final java.lang.String ACCESS_WIFI_STATE = "android.permission.ACCESS_WIFI_STATE";
     field public static final java.lang.String ACCOUNT_MANAGER = "android.permission.ACCOUNT_MANAGER";
+    field public static final java.lang.String ACTIVITY_EMBEDDING = "android.permission.ACTIVITY_EMBEDDING";
     field public static final java.lang.String ADD_VOICEMAIL = "com.android.voicemail.permission.ADD_VOICEMAIL";
     field public static final java.lang.String ALLOCATE_AGGRESSIVE = "android.permission.ALLOCATE_AGGRESSIVE";
     field public static final java.lang.String ALLOW_ANY_CODEC_FOR_PLAYBACK = "android.permission.ALLOW_ANY_CODEC_FOR_PLAYBACK";
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 54282b9..1d6957c 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -1855,6 +1855,10 @@
     <permission android:name="android.permission.MANAGE_ACTIVITY_STACKS"
         android:protectionLevel="signature|privileged" />
 
+    <!-- @SystemApi @hide Allows an application to embed other activities -->
+    <permission android:name="android.permission.ACTIVITY_EMBEDDING"
+                android:protectionLevel="signature|privileged" />
+
     <!-- Allows an application to start any activity, regardless of permission
          protection or exported state.
          @hide -->
diff --git a/data/etc/privapp-permissions-platform.xml b/data/etc/privapp-permissions-platform.xml
index a79376c..1a5cbd5 100644
--- a/data/etc/privapp-permissions-platform.xml
+++ b/data/etc/privapp-permissions-platform.xml
@@ -266,6 +266,7 @@
         <permission name="android.permission.DELETE_CACHE_FILES"/>
         <permission name="android.permission.DELETE_PACKAGES"/>
         <permission name="android.permission.DUMP"/>
+        <permission name="android.permission.ACTIVITY_EMBEDDING"/>
         <permission name="android.permission.FORCE_STOP_PACKAGES"/>
         <permission name="android.permission.GET_APP_OPS_STATS"/>
         <permission name="android.permission.INSTALL_LOCATION_PROVIDER"/>
diff --git a/packages/Shell/AndroidManifest.xml b/packages/Shell/AndroidManifest.xml
index e6d9a9a..2446775 100644
--- a/packages/Shell/AndroidManifest.xml
+++ b/packages/Shell/AndroidManifest.xml
@@ -114,6 +114,7 @@
     <uses-permission android:name="android.permission.GET_APP_OPS_STATS" />
     <uses-permission android:name="android.permission.VIBRATE" />
     <uses-permission android:name="android.permission.MANAGE_ACTIVITY_STACKS" />
+    <uses-permission android:name="android.permission.ACTIVITY_EMBEDDING" />
     <uses-permission android:name="android.permission.CONNECTIVITY_INTERNAL" />
     <uses-permission android:name="android.permission.CHANGE_COMPONENT_ENABLED_STATE" />
     <uses-permission android:name="android.permission.MANAGE_AUTO_FILL" />
diff --git a/services/core/java/com/android/server/am/ActivityRecord.java b/services/core/java/com/android/server/am/ActivityRecord.java
index 4a57369..1ed1ea6 100644
--- a/services/core/java/com/android/server/am/ActivityRecord.java
+++ b/services/core/java/com/android/server/am/ActivityRecord.java
@@ -1181,7 +1181,7 @@
      */
     boolean canBeLaunchedOnDisplay(int displayId) {
         return service.mStackSupervisor.canPlaceEntityOnDisplay(displayId,
-                supportsResizeableMultiWindow());
+                supportsResizeableMultiWindow(), launchedFromPid, launchedFromUid, info);
     }
 
     /**
diff --git a/services/core/java/com/android/server/am/ActivityStackSupervisor.java b/services/core/java/com/android/server/am/ActivityStackSupervisor.java
index 90d9149..fcdb91f 100644
--- a/services/core/java/com/android/server/am/ActivityStackSupervisor.java
+++ b/services/core/java/com/android/server/am/ActivityStackSupervisor.java
@@ -17,7 +17,6 @@
 package com.android.server.am;
 
 import static android.Manifest.permission.INTERNAL_SYSTEM_WINDOW;
-import static android.Manifest.permission.MANAGE_ACTIVITY_STACKS;
 import static android.Manifest.permission.START_ANY_ACTIVITY;
 import static android.Manifest.permission.START_TASKS_FROM_RECENTS;
 import static android.app.ActivityManager.LOCK_TASK_MODE_LOCKED;
@@ -491,9 +490,27 @@
     }
 
     /** Check if placing task or activity on specified display is allowed. */
-    boolean canPlaceEntityOnDisplay(int displayId, boolean resizeable) {
-        return displayId == DEFAULT_DISPLAY || (mService.mSupportsMultiDisplay
-                && (resizeable || displayConfigMatchesGlobal(displayId)));
+    boolean canPlaceEntityOnDisplay(int displayId, boolean resizeable, int callingPid,
+            int callingUid, ActivityInfo activityInfo) {
+        if (displayId == DEFAULT_DISPLAY) {
+            // No restrictions for the default display.
+            return true;
+        }
+        if (!mService.mSupportsMultiDisplay) {
+            // Can't launch on secondary displays if feature is not supported.
+            return false;
+        }
+        if (!resizeable && !displayConfigMatchesGlobal(displayId)) {
+            // Can't apply wrong configuration to non-resizeable activities.
+            return false;
+        }
+        if (!isCallerAllowedToLaunchOnDisplay(callingPid, callingUid, displayId, activityInfo)) {
+            // Can't place activities to a display that has restricted launch rules.
+            // In this case the request should be made by explicitly adding target display id and
+            // by caller with corresponding permissions. See #isCallerAllowedToLaunchOnDisplay().
+            return false;
+        }
+        return true;
     }
 
     /**
@@ -1679,8 +1696,8 @@
             // Check if someone tries to launch an activity on a private display with a different
             // owner.
             final int launchDisplayId = options.getLaunchDisplayId();
-            if (launchDisplayId != INVALID_DISPLAY
-                    && !isCallerAllowedToLaunchOnDisplay(callingPid, callingUid, launchDisplayId)) {
+            if (launchDisplayId != INVALID_DISPLAY && !isCallerAllowedToLaunchOnDisplay(callingPid,
+                    callingUid, launchDisplayId, aInfo)) {
                 final String msg = "Permission Denial: starting " + intent.toString()
                         + " from " + callerApp + " (pid=" + callingPid
                         + ", uid=" + callingUid + ") with launchDisplayId="
@@ -1694,17 +1711,24 @@
     }
 
     /** Check if caller is allowed to launch activities on specified display. */
-    boolean isCallerAllowedToLaunchOnDisplay(int callingPid, int callingUid, int launchDisplayId) {
+    boolean isCallerAllowedToLaunchOnDisplay(int callingPid, int callingUid, int launchDisplayId,
+            ActivityInfo aInfo) {
         if (DEBUG_TASKS) Slog.d(TAG, "Launch on display check: displayId=" + launchDisplayId
                 + " callingPid=" + callingPid + " callingUid=" + callingUid);
 
+        if (callingPid == -1 && callingUid == -1) {
+            if (DEBUG_TASKS) Slog.d(TAG, "Launch on display check: no caller info, skip check");
+            return true;
+        }
+
         final ActivityDisplay activityDisplay = getActivityDisplayOrCreateLocked(launchDisplayId);
         if (activityDisplay == null) {
             Slog.w(TAG, "Launch on display check: display not found");
             return false;
         }
 
-        // Check if the caller can manage activity stacks.
+        // Check if the caller has enough privileges to embed activities and launch to private
+        // displays.
         final int startAnyPerm = mService.checkPermission(INTERNAL_SYSTEM_WINDOW, callingPid,
                 callingUid);
         if (startAnyPerm == PERMISSION_GRANTED) {
@@ -1714,12 +1738,15 @@
         }
 
         if (activityDisplay.mDisplay.getType() == TYPE_VIRTUAL
-                && activityDisplay.mDisplay.getOwnerUid() != SYSTEM_UID) {
+                && activityDisplay.mDisplay.getOwnerUid() != SYSTEM_UID
+                && activityDisplay.mDisplay.getOwnerUid() != aInfo.applicationInfo.uid) {
             // Limit launching on virtual displays, because their contents can be read from Surface
             // by apps that created them.
-            if (DEBUG_TASKS) Slog.d(TAG, "Launch on display check:"
-                    + " disallow launch on virtual display for not-embedded activity");
-            return false;
+            if ((aInfo.flags & ActivityInfo.FLAG_ALLOW_EMBEDDED) == 0) {
+                if (DEBUG_TASKS) Slog.d(TAG, "Launch on display check:"
+                        + " disallow launch on virtual display for not-embedded activity.");
+                return false;
+            }
         }
 
         if (!activityDisplay.isPrivate()) {
diff --git a/services/core/java/com/android/server/am/ActivityStarter.java b/services/core/java/com/android/server/am/ActivityStarter.java
index a31c33e..c10c3bd 100644
--- a/services/core/java/com/android/server/am/ActivityStarter.java
+++ b/services/core/java/com/android/server/am/ActivityStarter.java
@@ -1841,13 +1841,30 @@
 
         final TaskRecord sourceTask = mSourceRecord.getTask();
         final ActivityStack sourceStack = mSourceRecord.getStack();
-        // We only want to allow changing stack if the target task is not the top one,
-        // otherwise we would move the launching task to the other side, rather than show
-        // two side by side.
-        final boolean moveStackAllowed = sourceStack.topTask() != sourceTask;
+        // We only want to allow changing stack in two cases:
+        // 1. If the target task is not the top one. Otherwise we would move the launching task to
+        //    the other side, rather than show two side by side.
+        // 2. If activity is not allowed on target display.
+        final int targetDisplayId = mTargetStack != null ? mTargetStack.mDisplayId
+                : sourceStack.mDisplayId;
+        final boolean moveStackAllowed = sourceStack.topTask() != sourceTask
+                || !mStartActivity.canBeLaunchedOnDisplay(targetDisplayId);
         if (moveStackAllowed) {
             mTargetStack = getLaunchStack(mStartActivity, mLaunchFlags, mStartActivity.getTask(),
                     mOptions);
+            // If target stack is not found now - we can't just rely on the source stack, as it may
+            // be not suitable. Let's check other displays.
+            if (mTargetStack == null && targetDisplayId != sourceStack.mDisplayId) {
+                // Can't use target display, lets find a stack on the source display.
+                mTargetStack = mService.mStackSupervisor.getValidLaunchStackOnDisplay(
+                        sourceStack.mDisplayId, mStartActivity);
+            }
+            if (mTargetStack == null) {
+                // There are no suitable stacks on the target and source display(s). Look on all
+                // displays.
+                mTargetStack = mService.mStackSupervisor.getNextValidLaunchStackLocked(
+                        mStartActivity, -1 /* currentFocus */);
+            }
         }
 
         if (mTargetStack == null) {
diff --git a/services/core/java/com/android/server/am/TaskRecord.java b/services/core/java/com/android/server/am/TaskRecord.java
index 96d8573..b776819 100644
--- a/services/core/java/com/android/server/am/TaskRecord.java
+++ b/services/core/java/com/android/server/am/TaskRecord.java
@@ -1582,7 +1582,8 @@
      */
     boolean canBeLaunchedOnDisplay(int displayId) {
         return mService.mStackSupervisor.canPlaceEntityOnDisplay(displayId,
-                isResizeable(false /* checkSupportsPip */));
+                isResizeable(false /* checkSupportsPip */), -1 /* don't check PID */,
+                -1 /* don't check UID */, null /* activityInfo */);
     }
 
     /**