UriPermissionOwner.java revision 9158825f9c41869689d6b1786d7c7aa8bdd524ce 
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
17package com.android.server.am;
18
19import android.content.Intent;
20import android.net.Uri;
21import android.os.Binder;
22import android.os.IBinder;
23
24import java.util.HashSet;
25import java.util.Iterator;
26
27final 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.removeReadOwner(this);
71                service.removeUriPermissionIfNeededLocked(perm);
72            }
73            readUriPermissions = null;
74        }
75        if ((mode&Intent.FLAG_GRANT_WRITE_URI_PERMISSION) != 0
76                && writeUriPermissions != null) {
77            for (UriPermission perm : writeUriPermissions) {
78                perm.removeWriteOwner(this);
79                service.removeUriPermissionIfNeededLocked(perm);
80            }
81            writeUriPermissions = null;
82        }
83    }
84
85    void removeUriPermissionLocked(Uri uri, int mode) {
86        if ((mode&Intent.FLAG_GRANT_READ_URI_PERMISSION) != 0
87                && readUriPermissions != null) {
88            Iterator<UriPermission> it = readUriPermissions.iterator();
89            while (it.hasNext()) {
90                UriPermission perm = it.next();
91                if (uri.equals(perm.uri)) {
92                    perm.removeReadOwner(this);
93                    service.removeUriPermissionIfNeededLocked(perm);
94                    it.remove();
95                }
96            }
97            if (readUriPermissions.size() == 0) {
98                readUriPermissions = null;
99            }
100        }
101        if ((mode&Intent.FLAG_GRANT_WRITE_URI_PERMISSION) != 0
102                && writeUriPermissions != null) {
103            Iterator<UriPermission> it = writeUriPermissions.iterator();
104            while (it.hasNext()) {
105                UriPermission perm = it.next();
106                if (uri.equals(perm.uri)) {
107                    perm.removeWriteOwner(this);
108                    service.removeUriPermissionIfNeededLocked(perm);
109                    it.remove();
110                }
111            }
112            if (writeUriPermissions.size() == 0) {
113                writeUriPermissions = null;
114            }
115        }
116    }
117
118    public void addReadPermission(UriPermission perm) {
119        if (readUriPermissions == null) {
120            readUriPermissions = new HashSet<UriPermission>();
121        }
122        readUriPermissions.add(perm);
123    }
124
125    public void addWritePermission(UriPermission perm) {
126        if (writeUriPermissions == null) {
127            writeUriPermissions = new HashSet<UriPermission>();
128        }
129        writeUriPermissions.add(perm);
130    }
131
132    public void removeReadPermission(UriPermission perm) {
133        readUriPermissions.remove(perm);
134        if (readUriPermissions.size() == 0) {
135            readUriPermissions = null;
136        }
137    }
138
139    public void removeWritePermission(UriPermission perm) {
140        writeUriPermissions.remove(perm);
141        if (writeUriPermissions.size() == 0) {
142            writeUriPermissions = null;
143        }
144    }
145
146    @Override
147    public String toString() {
148        return owner.toString();
149    }
150}
151