Add freeze period support in SystemUpdatePolicy

Freeze period is defined as a pair of calendar dates (recurring annually)
during which the system should block any incoming system updates, including
security patches. They are set on top of existing system udpate policy
types (automatic, windowed, postpone) such that outside the freeze
periods existing policy semantics will still apply. They are created to
allow admin to keep their device fleet from any destabilizing changes during
critical period of the year, for example during Christmas sales period.

Device Owner can set several freeze periods, although to prevent the device
from not receiving OTAs indefinitely, each single freeze period is
restricted to be at most 90 days, and adjacent freeze periods need to be at
least 60 days apart. To properly enforce these restrictions, any freeze
periods the device previously experienced is tracked by DevicePolicyManager
and are validated against any new policy. This is to deal with corner cases
such as the admin repeatedly set a short but overlapping freeze period on a
rolling basis, hence bypassing the 90-day freeze period restriction.

Test: runtest -c com.android.server.devicepolicy.SystemUpdatePolicyTest frameworks-services
Bug: 64813061
Change-Id: I2864192797dc194edd9c183b881da6cfe3fdba5e

1 files changed, 14 insertions, 1 deletions

diff --git a/cmds/dpm/src/com/android/commands/dpm/Dpm.java b/cmds/dpm/src/com/android/commands/dpm/Dpm.java
index 3ac70d668198..47581e10e937 100644
--- a/cmds/dpm/src/com/android/commands/dpm/Dpm.java
+++ b/cmds/dpm/src/com/android/commands/dpm/Dpm.java
@@ -45,6 +45,7 @@ public final class Dpm extends BaseCommand {
     private static final String COMMAND_SET_DEVICE_OWNER = "set-device-owner";
     private static final String COMMAND_SET_PROFILE_OWNER = "set-profile-owner";
     private static final String COMMAND_REMOVE_ACTIVE_ADMIN = "remove-active-admin";
+    private static final String COMMAND_CLEAR_FREEZE_PERIOD_RECORD = "clear-freeze-period-record";
 
     private IDevicePolicyManager mDevicePolicyManager;
     private int mUserId = UserHandle.USER_SYSTEM;
@@ -75,7 +76,11 @@ public final class Dpm extends BaseCommand {
                 "\n" +
                 "dpm remove-active-admin: Disables an active admin, the admin must have declared" +
                 " android:testOnly in the application in its manifest. This will also remove" +
-                " device and profile owners\n");
+                " device and profile owners\n" +
+                "\n" +
+                "dpm " + COMMAND_CLEAR_FREEZE_PERIOD_RECORD + ": clears framework-maintained " +
+                "record of past freeze periods that the device went through. For use during " +
+                "feature development to prevent triggering restriction on setting freeze periods");
     }
 
     @Override
@@ -101,6 +106,9 @@ public final class Dpm extends BaseCommand {
             case COMMAND_REMOVE_ACTIVE_ADMIN:
                 runRemoveActiveAdmin();
                 break;
+            case COMMAND_CLEAR_FREEZE_PERIOD_RECORD:
+                runClearFreezePeriodRecord();
+                break;
             default:
                 throw new IllegalArgumentException ("unknown command '" + command + "'");
         }
@@ -190,6 +198,11 @@ public final class Dpm extends BaseCommand {
                 + mComponent.toShortString() + " for user " + mUserId);
     }
 
+    private void runClearFreezePeriodRecord() throws RemoteException {
+        mDevicePolicyManager.clearSystemUpdatePolicyFreezePeriodRecord();
+        System.out.println("Success");
+    }
+
     private ComponentName parseComponentName(String component) {
         ComponentName cn = ComponentName.unflattenFromString(component);
         if (cn == null) {