Home | History | Annotate | Download | only in am 
      1 /*
      2  * Copyright (C) 2010 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.am;
     18 
     19 import android.content.Intent;
     20 import android.net.Uri;
     21 import android.os.Binder;
     22 import android.os.IBinder;
     23 
     24 import java.util.HashSet;
     25 import java.util.Iterator;
     26 
     27 class UriPermissionOwner {
     28     final ActivityManagerService service;
     29     final Object owner;
     30 
     31     Binder externalToken;
     32 
     33     HashSet<UriPermission> readUriPermissions; // special access to reading uris.
     34     HashSet<UriPermission> writeUriPermissions; // special access to writing uris.
     35 
     36     class ExternalToken extends Binder {
     37         UriPermissionOwner getOwner() {
     38             return UriPermissionOwner.this;
     39         }
     40     }
     41 
     42     UriPermissionOwner(ActivityManagerService _service, Object _owner) {
     43         service = _service;
     44         owner = _owner;
     45     }
     46 
     47     Binder getExternalTokenLocked() {
     48         if (externalToken == null) {
     49             externalToken = new ExternalToken();
     50         }
     51         return externalToken;
     52     }
     53 
     54     static UriPermissionOwner fromExternalToken(IBinder token) {
     55         if (token instanceof ExternalToken) {
     56             return ((ExternalToken)token).getOwner();
     57         }
     58         return null;
     59     }
     60 
     61     void removeUriPermissionsLocked() {
     62         removeUriPermissionsLocked(Intent.FLAG_GRANT_READ_URI_PERMISSION
     63                 | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
     64     }
     65 
     66     void removeUriPermissionsLocked(int mode) {
     67         if ((mode&Intent.FLAG_GRANT_READ_URI_PERMISSION) != 0
     68                 && readUriPermissions != null) {
     69             for (UriPermission perm : readUriPermissions) {
     70                 perm.readOwners.remove(this);
     71                 if (perm.readOwners.size() == 0 && (perm.globalModeFlags
     72                         &Intent.FLAG_GRANT_READ_URI_PERMISSION) == 0) {
     73                     perm.modeFlags &= ~Intent.FLAG_GRANT_READ_URI_PERMISSION;
     74                     service.removeUriPermissionIfNeededLocked(perm);
     75                 }
     76             }
     77             readUriPermissions = null;
     78         }
     79         if ((mode&Intent.FLAG_GRANT_WRITE_URI_PERMISSION) != 0
     80                 && writeUriPermissions != null) {
     81             for (UriPermission perm : writeUriPermissions) {
     82                 perm.writeOwners.remove(this);
     83                 if (perm.writeOwners.size() == 0 && (perm.globalModeFlags
     84                         &Intent.FLAG_GRANT_WRITE_URI_PERMISSION) == 0) {
     85                     perm.modeFlags &= ~Intent.FLAG_GRANT_WRITE_URI_PERMISSION;
     86                     service.removeUriPermissionIfNeededLocked(perm);
     87                 }
     88             }
     89             writeUriPermissions = null;
     90         }
     91     }
     92 
     93     void removeUriPermissionLocked(Uri uri, int mode) {
     94         if ((mode&Intent.FLAG_GRANT_READ_URI_PERMISSION) != 0
     95                 && readUriPermissions != null) {
     96             Iterator<UriPermission> it = readUriPermissions.iterator();
     97             while (it.hasNext()) {
     98                 UriPermission perm = it.next();
     99                 if (uri.equals(perm.uri)) {
    100                     perm.readOwners.remove(this);
    101                     if (perm.readOwners.size() == 0 && (perm.globalModeFlags
    102                             &Intent.FLAG_GRANT_READ_URI_PERMISSION) == 0) {
    103                         perm.modeFlags &= ~Intent.FLAG_GRANT_READ_URI_PERMISSION;
    104                         service.removeUriPermissionIfNeededLocked(perm);
    105                     }
    106                     it.remove();
    107                 }
    108             }
    109             if (readUriPermissions.size() == 0) {
    110                 readUriPermissions = null;
    111             }
    112         }
    113         if ((mode&Intent.FLAG_GRANT_WRITE_URI_PERMISSION) != 0
    114                 && writeUriPermissions != null) {
    115             Iterator<UriPermission> it = writeUriPermissions.iterator();
    116             while (it.hasNext()) {
    117                 UriPermission perm = it.next();
    118                 if (uri.equals(perm.uri)) {
    119                     perm.writeOwners.remove(this);
    120                     if (perm.writeOwners.size() == 0 && (perm.globalModeFlags
    121                             &Intent.FLAG_GRANT_WRITE_URI_PERMISSION) == 0) {
    122                         perm.modeFlags &= ~Intent.FLAG_GRANT_WRITE_URI_PERMISSION;
    123                         service.removeUriPermissionIfNeededLocked(perm);
    124                     }
    125                     it.remove();
    126                 }
    127             }
    128             if (writeUriPermissions.size() == 0) {
    129                 writeUriPermissions = null;
    130             }
    131         }
    132     }
    133 
    134     public void addReadPermission(UriPermission perm) {
    135         if (readUriPermissions == null) {
    136             readUriPermissions = new HashSet<UriPermission>();
    137         }
    138         readUriPermissions.add(perm);
    139     }
    140 
    141     public void addWritePermission(UriPermission perm) {
    142         if (writeUriPermissions == null) {
    143             writeUriPermissions = new HashSet<UriPermission>();
    144         }
    145         writeUriPermissions.add(perm);
    146     }
    147 
    148     public void removeReadPermission(UriPermission perm) {
    149         readUriPermissions.remove(perm);
    150         if (readUriPermissions.size() == 0) {
    151             readUriPermissions = null;
    152         }
    153     }
    154 
    155     public void removeWritePermission(UriPermission perm) {
    156         writeUriPermissions.remove(perm);
    157         if (writeUriPermissions.size() == 0) {
    158             writeUriPermissions = null;
    159         }
    160     }
    161 
    162     @Override
    163     public String toString() {
    164         return owner.toString();
    165     }
    166 }
    167