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 * Representation of a user on the device. 21 */ 22 public final class UserHandle implements Parcelable { 23 /** 24 * @hide Range of uids allocated for a user. 25 */ 26 public static final int PER_USER_RANGE = 100000; 27 28 /** @hide A user id to indicate all users on the device */ 29 public static final int USER_ALL = -1; 30 31 /** @hide A user handle to indicate all users on the device */ 32 public static final UserHandle ALL = new UserHandle(USER_ALL); 33 34 /** @hide A user id to indicate the currently active user */ 35 public static final int USER_CURRENT = -2; 36 37 /** @hide A user handle to indicate the current user of the device */ 38 public static final UserHandle CURRENT = new UserHandle(USER_CURRENT); 39 40 /** @hide A user id to indicate that we would like to send to the current 41 * user, but if this is calling from a user process then we will send it 42 * to the caller's user instead of failing wiht a security exception */ 43 public static final int USER_CURRENT_OR_SELF = -3; 44 45 /** @hide A user handle to indicate that we would like to send to the current 46 * user, but if this is calling from a user process then we will send it 47 * to the caller's user instead of failing wiht a security exception */ 48 public static final UserHandle CURRENT_OR_SELF = new UserHandle(USER_CURRENT_OR_SELF); 49 50 /** @hide An undefined user id */ 51 public static final int USER_NULL = -10000; 52 53 /** @hide A user id constant to indicate the "owner" user of the device */ 54 public static final int USER_OWNER = 0; 55 56 /** @hide A user handle to indicate the primary/owner user of the device */ 57 public static final UserHandle OWNER = new UserHandle(USER_OWNER); 58 59 /** 60 * @hide Enable multi-user related side effects. Set this to false if 61 * there are problems with single user use-cases. 62 */ 63 public static final boolean MU_ENABLED = true; 64 65 final int mHandle; 66 67 /** 68 * Checks to see if the user id is the same for the two uids, i.e., they belong to the same 69 * user. 70 * @hide 71 */ 72 public static final boolean isSameUser(int uid1, int uid2) { 73 return getUserId(uid1) == getUserId(uid2); 74 } 75 76 /** 77 * Checks to see if both uids are referring to the same app id, ignoring the user id part of the 78 * uids. 79 * @param uid1 uid to compare 80 * @param uid2 other uid to compare 81 * @return whether the appId is the same for both uids 82 * @hide 83 */ 84 public static final boolean isSameApp(int uid1, int uid2) { 85 return getAppId(uid1) == getAppId(uid2); 86 } 87 88 /** @hide */ 89 public static final boolean isIsolated(int uid) { 90 if (uid > 0) { 91 final int appId = getAppId(uid); 92 return appId >= Process.FIRST_ISOLATED_UID && appId <= Process.LAST_ISOLATED_UID; 93 } else { 94 return false; 95 } 96 } 97 98 /** @hide */ 99 public static boolean isApp(int uid) { 100 if (uid > 0) { 101 final int appId = getAppId(uid); 102 return appId >= Process.FIRST_APPLICATION_UID && appId <= Process.LAST_APPLICATION_UID; 103 } else { 104 return false; 105 } 106 } 107 108 /** 109 * Returns the user id for a given uid. 110 * @hide 111 */ 112 public static final int getUserId(int uid) { 113 if (MU_ENABLED) { 114 return uid / PER_USER_RANGE; 115 } else { 116 return 0; 117 } 118 } 119 120 /** @hide */ 121 public static final int getCallingUserId() { 122 return getUserId(Binder.getCallingUid()); 123 } 124 125 /** 126 * Returns the uid that is composed from the userId and the appId. 127 * @hide 128 */ 129 public static final int getUid(int userId, int appId) { 130 if (MU_ENABLED) { 131 return userId * PER_USER_RANGE + (appId % PER_USER_RANGE); 132 } else { 133 return appId; 134 } 135 } 136 137 /** 138 * Returns the app id (or base uid) for a given uid, stripping out the user id from it. 139 * @hide 140 */ 141 public static final int getAppId(int uid) { 142 return uid % PER_USER_RANGE; 143 } 144 145 /** 146 * Returns the shared app gid for a given uid or appId. 147 * @hide 148 */ 149 public static final int getSharedAppGid(int id) { 150 return Process.FIRST_SHARED_APPLICATION_GID + (id % PER_USER_RANGE) 151 - Process.FIRST_APPLICATION_UID; 152 } 153 154 /** 155 * Returns the user id of the current process 156 * @return user id of the current process 157 * @hide 158 */ 159 public static final int myUserId() { 160 return getUserId(Process.myUid()); 161 } 162 163 /** @hide */ 164 public UserHandle(int h) { 165 mHandle = h; 166 } 167 168 /** @hide */ 169 public int getIdentifier() { 170 return mHandle; 171 } 172 173 @Override 174 public String toString() { 175 return "UserHandle{" + mHandle + "}"; 176 } 177 178 @Override 179 public boolean equals(Object obj) { 180 try { 181 if (obj != null) { 182 UserHandle other = (UserHandle)obj; 183 return mHandle == other.mHandle; 184 } 185 } catch (ClassCastException e) { 186 } 187 return false; 188 } 189 190 @Override 191 public int hashCode() { 192 return mHandle; 193 } 194 195 public int describeContents() { 196 return 0; 197 } 198 199 public void writeToParcel(Parcel out, int flags) { 200 out.writeInt(mHandle); 201 } 202 203 /** 204 * Write a UserHandle to a Parcel, handling null pointers. Must be 205 * read with {@link #readFromParcel(Parcel)}. 206 * 207 * @param h The UserHandle to be written. 208 * @param out The Parcel in which the UserHandle will be placed. 209 * 210 * @see #readFromParcel(Parcel) 211 */ 212 public static void writeToParcel(UserHandle h, Parcel out) { 213 if (h != null) { 214 h.writeToParcel(out, 0); 215 } else { 216 out.writeInt(USER_NULL); 217 } 218 } 219 220 /** 221 * Read a UserHandle from a Parcel that was previously written 222 * with {@link #writeToParcel(UserHandle, Parcel)}, returning either 223 * a null or new object as appropriate. 224 * 225 * @param in The Parcel from which to read the UserHandle 226 * @return Returns a new UserHandle matching the previously written 227 * object, or null if a null had been written. 228 * 229 * @see #writeToParcel(UserHandle, Parcel) 230 */ 231 public static UserHandle readFromParcel(Parcel in) { 232 int h = in.readInt(); 233 return h != USER_NULL ? new UserHandle(h) : null; 234 } 235 236 public static final Parcelable.Creator<UserHandle> CREATOR 237 = new Parcelable.Creator<UserHandle>() { 238 public UserHandle createFromParcel(Parcel in) { 239 return new UserHandle(in); 240 } 241 242 public UserHandle[] newArray(int size) { 243 return new UserHandle[size]; 244 } 245 }; 246 247 /** 248 * Instantiate a new UserHandle from the data in a Parcel that was 249 * previously written with {@link #writeToParcel(Parcel, int)}. Note that you 250 * must not use this with data written by 251 * {@link #writeToParcel(UserHandle, Parcel)} since it is not possible 252 * to handle a null UserHandle here. 253 * 254 * @param in The Parcel containing the previously written UserHandle, 255 * positioned at the location in the buffer where it was written. 256 */ 257 public UserHandle(Parcel in) { 258 mHandle = in.readInt(); 259 } 260 } 261
