1 /*
2  * Copyright (C) 2012 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.server.wm;
18 
19 import android.app.ActivityManagerNative;
20 import android.app.admin.DevicePolicyManager;
21 import android.content.Context;
22 import android.os.Handler;
23 import android.os.IBinder;
24 import android.os.Message;
25 import android.os.RemoteException;
26 import android.os.TokenWatcher;
27 import android.util.Log;
28 import android.util.Pair;
29 import android.view.WindowManagerPolicy;
30 
31 public class KeyguardDisableHandler extends Handler {
32     private static final String TAG = "KeyguardDisableHandler";
33 
34     private static final int ALLOW_DISABLE_YES = 1;
35     private static final int ALLOW_DISABLE_NO = 0;
36     private static final int ALLOW_DISABLE_UNKNOWN = -1; // check with DevicePolicyManager
37     private int mAllowDisableKeyguard = ALLOW_DISABLE_UNKNOWN; // sync'd by mKeyguardTokenWatcher
38 
39     // Message.what constants
40     static final int KEYGUARD_DISABLE = 1;
41     static final int KEYGUARD_REENABLE = 2;
42     static final int KEYGUARD_POLICY_CHANGED = 3;
43 
44     final Context mContext;
45     final WindowManagerPolicy mPolicy;
46     KeyguardTokenWatcher mKeyguardTokenWatcher;
47 
KeyguardDisableHandler(final Context context, final WindowManagerPolicy policy)48     public KeyguardDisableHandler(final Context context, final WindowManagerPolicy policy) {
49         mContext = context;
50         mPolicy = policy;
51     }
52 
53     @SuppressWarnings("unchecked")
54     @Override
handleMessage(Message msg)55     public void handleMessage(Message msg) {
56         if (mKeyguardTokenWatcher == null) {
57             mKeyguardTokenWatcher = new KeyguardTokenWatcher(this);
58         }
59 
60         switch (msg.what) {
61             case KEYGUARD_DISABLE:
62                 final Pair<IBinder, String> pair = (Pair<IBinder, String>)msg.obj;
63                 mKeyguardTokenWatcher.acquire(pair.first, pair.second);
64                 break;
65 
66             case KEYGUARD_REENABLE:
67                 mKeyguardTokenWatcher.release((IBinder)msg.obj);
68                 break;
69 
70             case KEYGUARD_POLICY_CHANGED:
71                 mAllowDisableKeyguard = ALLOW_DISABLE_UNKNOWN;
72                 if (mKeyguardTokenWatcher.isAcquired()) {
73                     // If we are currently disabled we need to know if the keyguard
74                     // should be re-enabled, so determine the allow state immediately.
75                     mKeyguardTokenWatcher.updateAllowState();
76                     if (mAllowDisableKeyguard != ALLOW_DISABLE_YES) {
77                         mPolicy.enableKeyguard(true);
78                     }
79                 } else {
80                     // lazily evaluate this next time we're asked to disable keyguard
81                     mPolicy.enableKeyguard(true);
82                 }
83                 break;
84         }
85     }
86 
87     class KeyguardTokenWatcher extends TokenWatcher {
88 
KeyguardTokenWatcher(final Handler handler)89         public KeyguardTokenWatcher(final Handler handler) {
90             super(handler, TAG);
91         }
92 
updateAllowState()93         public void updateAllowState() {
94             // We fail safe and prevent disabling keyguard in the unlikely event this gets
95             // called before DevicePolicyManagerService has started.
96             DevicePolicyManager dpm = (DevicePolicyManager) mContext.getSystemService(
97                     Context.DEVICE_POLICY_SERVICE);
98             if (dpm != null) {
99                 try {
100                     mAllowDisableKeyguard = dpm.getPasswordQuality(null,
101                             ActivityManagerNative.getDefault().getCurrentUser().id)
102                             == DevicePolicyManager.PASSWORD_QUALITY_UNSPECIFIED ?
103                                     ALLOW_DISABLE_YES : ALLOW_DISABLE_NO;
104                 } catch (RemoteException re) {
105                     // Nothing much we can do
106                 }
107             }
108         }
109 
110         @Override
acquired()111         public void acquired() {
112             if (mAllowDisableKeyguard == ALLOW_DISABLE_UNKNOWN) {
113                 updateAllowState();
114             }
115             if (mAllowDisableKeyguard == ALLOW_DISABLE_YES) {
116                 mPolicy.enableKeyguard(false);
117             } else {
118                 Log.v(TAG, "Not disabling keyguard since device policy is enforced");
119             }
120         }
121 
122         @Override
released()123         public void released() {
124             mPolicy.enableKeyguard(true);
125         }
126     }
127 }
128