Whitelist packages from VPN lockdown: DPM API.

Bug: 77468593
Test: atest MixedDeviceOwnerTest#testAlwaysOnVpn
Test: atest MixedDeviceOwnerTest#testAlwaysOnVpnAcrossReboot
Change-Id: I7508070f828fb7150df5d9e34846535d57c6a7c3
diff --git a/api/current.txt b/api/current.txt
index fe7f97f..f33f209 100755
--- a/api/current.txt
+++ b/api/current.txt
@@ -6450,6 +6450,7 @@
     method @Nullable public String[] getAccountTypesWithManagementDisabled();
     method @Nullable public java.util.List<android.content.ComponentName> getActiveAdmins();
     method @NonNull public java.util.Set<java.lang.String> getAffiliationIds(@NonNull android.content.ComponentName);
+    method @Nullable public java.util.List<java.lang.String> getAlwaysOnVpnLockdownWhitelist(@NonNull android.content.ComponentName);
     method @Nullable public String getAlwaysOnVpnPackage(@NonNull android.content.ComponentName);
     method @WorkerThread @NonNull public android.os.Bundle getApplicationRestrictions(@Nullable android.content.ComponentName, String);
     method @Deprecated @Nullable public String getApplicationRestrictionsManagingPackage(@NonNull android.content.ComponentName);
@@ -6519,6 +6520,7 @@
     method public boolean isActivePasswordSufficient();
     method public boolean isAdminActive(@NonNull android.content.ComponentName);
     method public boolean isAffiliatedUser();
+    method public boolean isAlwaysOnVpnLockdownEnabled(@NonNull android.content.ComponentName);
     method public boolean isApplicationHidden(@NonNull android.content.ComponentName, String);
     method public boolean isBackupServiceEnabled(@NonNull android.content.ComponentName);
     method @Deprecated public boolean isCallerApplicationRestrictionsManagingPackage();
@@ -6555,7 +6557,8 @@
     method @Nullable public java.util.List<android.app.admin.SecurityLog.SecurityEvent> retrieveSecurityLogs(@NonNull android.content.ComponentName);
     method public void setAccountManagementDisabled(@NonNull android.content.ComponentName, String, boolean);
     method public void setAffiliationIds(@NonNull android.content.ComponentName, @NonNull java.util.Set<java.lang.String>);
-    method public void setAlwaysOnVpnPackage(@NonNull android.content.ComponentName, @Nullable String, boolean) throws android.content.pm.PackageManager.NameNotFoundException, java.lang.UnsupportedOperationException;
+    method public void setAlwaysOnVpnPackage(@NonNull android.content.ComponentName, @Nullable String, boolean) throws android.content.pm.PackageManager.NameNotFoundException;
+    method public void setAlwaysOnVpnPackage(@NonNull android.content.ComponentName, @Nullable String, boolean, @Nullable java.util.List<java.lang.String>) throws android.content.pm.PackageManager.NameNotFoundException;
     method public boolean setApplicationHidden(@NonNull android.content.ComponentName, String, boolean);
     method @WorkerThread public void setApplicationRestrictions(@Nullable android.content.ComponentName, String, android.os.Bundle);
     method @Deprecated public void setApplicationRestrictionsManagingPackage(@NonNull android.content.ComponentName, @Nullable String) throws android.content.pm.PackageManager.NameNotFoundException;
diff --git a/core/java/android/app/admin/DevicePolicyManager.java b/core/java/android/app/admin/DevicePolicyManager.java
index a965e5f..3871d7a 100644
--- a/core/java/android/app/admin/DevicePolicyManager.java
+++ b/core/java/android/app/admin/DevicePolicyManager.java
@@ -4469,11 +4469,16 @@
     }
 
     /**
+     * Service-specific error code used in implementation of {@code setAlwaysOnVpnPackage} methods.
+     * @hide
+     */
+    public static final int ERROR_VPN_PACKAGE_NOT_FOUND = 1;
+
+    /**
      * Called by a device or profile owner to configure an always-on VPN connection through a
      * specific application for the current user. This connection is automatically granted and
      * persisted after a reboot.
-     * <p>
-     * To support the always-on feature, an app must
+     * <p> To support the always-on feature, an app must
      * <ul>
      *     <li>declare a {@link android.net.VpnService} in its manifest, guarded by
      *         {@link android.Manifest.permission#BIND_VPN_SERVICE};</li>
@@ -4482,25 +4487,61 @@
      *         {@link android.net.VpnService#SERVICE_META_DATA_SUPPORTS_ALWAYS_ON}.</li>
      * </ul>
      * The call will fail if called with the package name of an unsupported VPN app.
+     * <p> Enabling lockdown via {@code lockdownEnabled} argument carries the risk that any failure
+     * of the VPN provider could break networking for all apps.
      *
      * @param vpnPackage The package name for an installed VPN app on the device, or {@code null} to
      *        remove an existing always-on VPN configuration.
      * @param lockdownEnabled {@code true} to disallow networking when the VPN is not connected or
-     *        {@code false} otherwise. This carries the risk that any failure of the VPN provider
-     *        could break networking for all apps. This has no effect when clearing.
+     *        {@code false} otherwise. This has no effect when clearing.
      * @throws SecurityException if {@code admin} is not a device or a profile owner.
      * @throws NameNotFoundException if {@code vpnPackage} is not installed.
      * @throws UnsupportedOperationException if {@code vpnPackage} exists but does not support being
      *         set as always-on, or if always-on VPN is not available.
+     * @see #setAlwaysOnVpnPackage(ComponentName, String, boolean, List)
      */
     public void setAlwaysOnVpnPackage(@NonNull ComponentName admin, @Nullable String vpnPackage,
-            boolean lockdownEnabled)
-            throws NameNotFoundException, UnsupportedOperationException {
+            boolean lockdownEnabled) throws NameNotFoundException {
+        setAlwaysOnVpnPackage(admin, vpnPackage, lockdownEnabled, Collections.emptyList());
+    }
+
+    /**
+     * A version of {@link #setAlwaysOnVpnPackage(ComponentName, String, boolean)} that allows the
+     * admin to specify a set of apps that should be able to access the network directly when VPN
+     * is not connected. When VPN connects these apps switch over to VPN if allowed to use that VPN.
+     * System apps can always bypass VPN.
+     * <p> Note that the system doesn't update the whitelist when packages are installed or
+     * uninstalled, the admin app must call this method to keep the list up to date.
+     *
+     * @param vpnPackage package name for an installed VPN app on the device, or {@code null}
+     *         to remove an existing always-on VPN configuration
+     * @param lockdownEnabled {@code true} to disallow networking when the VPN is not connected or
+     *         {@code false} otherwise. This has no effect when clearing.
+     * @param lockdownWhitelist Packages that will be able to access the network directly when VPN
+     *         is in lockdown mode but not connected. Has no effect when clearing.
+     * @throws SecurityException if {@code admin} is not a device or a profile
+     *         owner.
+     * @throws NameNotFoundException if {@code vpnPackage} or one of
+     *         {@code lockdownWhitelist} is not installed.
+     * @throws UnsupportedOperationException if {@code vpnPackage} exists but does
+     *         not support being set as always-on, or if always-on VPN is not
+     *         available.
+     */
+    public void setAlwaysOnVpnPackage(@NonNull ComponentName admin, @Nullable String vpnPackage,
+            boolean lockdownEnabled, @Nullable List<String> lockdownWhitelist)
+            throws NameNotFoundException {
         throwIfParentInstance("setAlwaysOnVpnPackage");
         if (mService != null) {
             try {
-                if (!mService.setAlwaysOnVpnPackage(admin, vpnPackage, lockdownEnabled)) {
-                    throw new NameNotFoundException(vpnPackage);
+                mService.setAlwaysOnVpnPackage(
+                        admin, vpnPackage, lockdownEnabled, lockdownWhitelist);
+            } catch (ServiceSpecificException e) {
+                switch (e.errorCode) {
+                    case ERROR_VPN_PACKAGE_NOT_FOUND:
+                        throw new NameNotFoundException(e.getMessage());
+                    default:
+                        throw new RuntimeException(
+                                "Unknown error setting always-on VPN: " + e.errorCode, e);
                 }
             } catch (RemoteException e) {
                 throw e.rethrowFromSystemServer();
@@ -4509,6 +4550,51 @@
     }
 
     /**
+     * Called by device or profile owner to query whether current always-on VPN is configured in
+     * lockdown mode. Returns {@code false} when no always-on configuration is set.
+     *
+     * @param admin Which {@link DeviceAdminReceiver} this request is associated with.
+     *
+     * @throws SecurityException if {@code admin} is not a device or a profile owner.
+     *
+     * @see #setAlwaysOnVpnPackage(ComponentName, String, boolean)
+     */
+    public boolean isAlwaysOnVpnLockdownEnabled(@NonNull ComponentName admin) {
+        throwIfParentInstance("isAlwaysOnVpnLockdownEnabled");
+        if (mService != null) {
+            try {
+                return mService.isAlwaysOnVpnLockdownEnabled(admin);
+            } catch (RemoteException e) {
+                throw e.rethrowFromSystemServer();
+            }
+        }
+        return false;
+    }
+
+    /**
+     * Called by device or profile owner to query the list of packages that are allowed to access
+     * the network directly when always-on VPN is in lockdown mode but not connected. Returns
+     * {@code null} when always-on VPN is not active or not in lockdown mode.
+     *
+     * @param admin Which {@link DeviceAdminReceiver} this request is associated with.
+     *
+     * @throws SecurityException if {@code admin} is not a device or a profile owner.
+     *
+     * @see #setAlwaysOnVpnPackage(ComponentName, String, boolean, List)
+     */
+    public @Nullable List<String> getAlwaysOnVpnLockdownWhitelist(@NonNull ComponentName admin) {
+        throwIfParentInstance("getAlwaysOnVpnLockdownWhitelist");
+        if (mService != null) {
+            try {
+                return mService.getAlwaysOnVpnLockdownWhitelist(admin);
+            } catch (RemoteException e) {
+                throw e.rethrowFromSystemServer();
+            }
+        }
+        return null;
+    }
+
+    /**
      * Called by a device or profile owner to read the name of the package administering an
      * always-on VPN connection for the current user. If there is no such package, or the always-on
      * VPN is provided by the system instead of by an application, {@code null} will be returned.
diff --git a/core/java/android/app/admin/IDevicePolicyManager.aidl b/core/java/android/app/admin/IDevicePolicyManager.aidl
index 37508cd..0046302 100644
--- a/core/java/android/app/admin/IDevicePolicyManager.aidl
+++ b/core/java/android/app/admin/IDevicePolicyManager.aidl
@@ -182,8 +182,10 @@
     void setCertInstallerPackage(in ComponentName who, String installerPackage);
     String getCertInstallerPackage(in ComponentName who);
 
-    boolean setAlwaysOnVpnPackage(in ComponentName who, String vpnPackage, boolean lockdown);
+    boolean setAlwaysOnVpnPackage(in ComponentName who, String vpnPackage, boolean lockdown, in List<String> lockdownWhitelist);
     String getAlwaysOnVpnPackage(in ComponentName who);
+    boolean isAlwaysOnVpnLockdownEnabled(in ComponentName who);
+    List<String> getAlwaysOnVpnLockdownWhitelist(in ComponentName who);
 
     void addPersistentPreferredActivity(in ComponentName admin, in IntentFilter filter, in ComponentName activity);
     void clearPackagePersistentPreferredActivities(in ComponentName admin, String packageName);
diff --git a/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java b/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java
index 11fe763..9c6b52f 100644
--- a/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java
+++ b/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java
@@ -1852,7 +1852,11 @@
         }
 
         AlarmManager getAlarmManager() {
-            return (AlarmManager) mContext.getSystemService(AlarmManager.class);
+            return mContext.getSystemService(AlarmManager.class);
+        }
+
+        ConnectivityManager getConnectivityManager() {
+            return mContext.getSystemService(ConnectivityManager.class);
         }
 
         IWindowManager getIWindowManager() {
@@ -5877,7 +5881,8 @@
      * @throws UnsupportedOperationException if the package does not support being set as always-on.
      */
     @Override
-    public boolean setAlwaysOnVpnPackage(ComponentName admin, String vpnPackage, boolean lockdown)
+    public boolean setAlwaysOnVpnPackage(ComponentName admin, String vpnPackage, boolean lockdown,
+            List<String> lockdownWhitelist)
             throws SecurityException {
         enforceProfileOrDeviceOwner(admin);
 
@@ -5885,11 +5890,23 @@
         final long token = mInjector.binderClearCallingIdentity();
         try {
             if (vpnPackage != null && !isPackageInstalledForUser(vpnPackage, userId)) {
-                return false;
+                Slog.w(LOG_TAG, "Non-existent VPN package specified: " + vpnPackage);
+                throw new ServiceSpecificException(
+                        DevicePolicyManager.ERROR_VPN_PACKAGE_NOT_FOUND, vpnPackage);
             }
-            ConnectivityManager connectivityManager = (ConnectivityManager)
-                    mContext.getSystemService(Context.CONNECTIVITY_SERVICE);
-            if (!connectivityManager.setAlwaysOnVpnPackageForUser(userId, vpnPackage, lockdown)) {
+
+            if (vpnPackage != null && lockdown && lockdownWhitelist != null) {
+                for (String packageName : lockdownWhitelist) {
+                    if (!isPackageInstalledForUser(packageName, userId)) {
+                        Slog.w(LOG_TAG, "Non-existent package in VPN whitelist: " + packageName);
+                        throw new ServiceSpecificException(
+                                DevicePolicyManager.ERROR_VPN_PACKAGE_NOT_FOUND, packageName);
+                    }
+                }
+            }
+            // If some package is uninstalled after the check above, it will be ignored by CM.
+            if (!mInjector.getConnectivityManager().setAlwaysOnVpnPackageForUser(
+                    userId, vpnPackage, lockdown, lockdownWhitelist)) {
                 throw new UnsupportedOperationException();
             }
         } finally {
@@ -5899,16 +5916,40 @@
     }
 
     @Override
-    public String getAlwaysOnVpnPackage(ComponentName admin)
+    public String getAlwaysOnVpnPackage(ComponentName admin) throws SecurityException {
+        enforceProfileOrDeviceOwner(admin);
+
+        final int userId = mInjector.userHandleGetCallingUserId();
+        final long token = mInjector.binderClearCallingIdentity();
+        try {
+            return mInjector.getConnectivityManager().getAlwaysOnVpnPackageForUser(userId);
+        } finally {
+            mInjector.binderRestoreCallingIdentity(token);
+        }
+    }
+
+    @Override
+    public boolean isAlwaysOnVpnLockdownEnabled(ComponentName admin) throws SecurityException {
+        enforceProfileOrDeviceOwner(admin);
+
+        final int userId = mInjector.userHandleGetCallingUserId();
+        final long token = mInjector.binderClearCallingIdentity();
+        try {
+            return mInjector.getConnectivityManager().isVpnLockdownEnabled(userId);
+        } finally {
+            mInjector.binderRestoreCallingIdentity(token);
+        }
+    }
+
+    @Override
+    public List<String> getAlwaysOnVpnLockdownWhitelist(ComponentName admin)
             throws SecurityException {
         enforceProfileOrDeviceOwner(admin);
 
         final int userId = mInjector.userHandleGetCallingUserId();
         final long token = mInjector.binderClearCallingIdentity();
-        try{
-            ConnectivityManager connectivityManager = (ConnectivityManager)
-                    mContext.getSystemService(Context.CONNECTIVITY_SERVICE);
-            return connectivityManager.getAlwaysOnVpnPackageForUser(userId);
+        try {
+            return mInjector.getConnectivityManager().getVpnLockdownWhitelist(userId);
         } finally {
             mInjector.binderRestoreCallingIdentity(token);
         }
@@ -6378,9 +6419,7 @@
         }
         long token = mInjector.binderClearCallingIdentity();
         try {
-            ConnectivityManager connectivityManager = (ConnectivityManager)
-                    mContext.getSystemService(Context.CONNECTIVITY_SERVICE);
-            connectivityManager.setGlobalProxy(proxyInfo);
+            mInjector.getConnectivityManager().setGlobalProxy(proxyInfo);
         } finally {
             mInjector.binderRestoreCallingIdentity(token);
         }