1 /* 2 * Copyright (C) 2011 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 android.os; 18 19 /** 20 * @hide 21 */ 22 public final class UserId { 23 /** 24 * Range of IDs allocated for a user. 25 * 26 * @hide 27 */ 28 public static final int PER_USER_RANGE = 100000; 29 30 public static final int USER_ALL = -1; 31 32 /** 33 * Enable multi-user related side effects. Set this to false if there are problems with single 34 * user usecases. 35 * */ 36 public static final boolean MU_ENABLED = true; 37 38 /** 39 * Checks to see if the user id is the same for the two uids, i.e., they belong to the same 40 * user. 41 * @hide 42 */ 43 public static final boolean isSameUser(int uid1, int uid2) { 44 return getUserId(uid1) == getUserId(uid2); 45 } 46 47 /** 48 * Checks to see if both uids are referring to the same app id, ignoring the user id part of the 49 * uids. 50 * @param uid1 uid to compare 51 * @param uid2 other uid to compare 52 * @return whether the appId is the same for both uids 53 * @hide 54 */ 55 public static final boolean isSameApp(int uid1, int uid2) { 56 return getAppId(uid1) == getAppId(uid2); 57 } 58 59 public static final boolean isIsolated(int uid) { 60 uid = getAppId(uid); 61 return uid >= Process.FIRST_ISOLATED_UID && uid <= Process.LAST_ISOLATED_UID; 62 } 63 64 public static boolean isApp(int uid) { 65 if (uid > 0) { 66 uid = UserId.getAppId(uid); 67 return uid >= Process.FIRST_APPLICATION_UID && uid <= Process.LAST_APPLICATION_UID; 68 } else { 69 return false; 70 } 71 } 72 73 /** 74 * Returns the user id for a given uid. 75 * @hide 76 */ 77 public static final int getUserId(int uid) { 78 if (MU_ENABLED) { 79 return uid / PER_USER_RANGE; 80 } else { 81 return 0; 82 } 83 } 84 85 public static final int getCallingUserId() { 86 return getUserId(Binder.getCallingUid()); 87 } 88 89 /** 90 * Returns the uid that is composed from the userId and the appId. 91 * @hide 92 */ 93 public static final int getUid(int userId, int appId) { 94 if (MU_ENABLED) { 95 return userId * PER_USER_RANGE + (appId % PER_USER_RANGE); 96 } else { 97 return appId; 98 } 99 } 100 101 /** 102 * Returns the app id (or base uid) for a given uid, stripping out the user id from it. 103 * @hide 104 */ 105 public static final int getAppId(int uid) { 106 return uid % PER_USER_RANGE; 107 } 108 109 /** 110 * Returns the user id of the current process 111 * @return user id of the current process 112 */ 113 public static final int myUserId() { 114 return getUserId(Process.myUid()); 115 } 116 } 117
