UserHandle.java revision 02cb6e773b323a0d54b21f43460a23f668b7727c
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 17package android.os; 18 19import android.annotation.SystemApi; 20 21import java.io.PrintWriter; 22 23/** 24 * Representation of a user on the device. 25 */ 26public final class UserHandle implements Parcelable { 27 /** 28 * @hide Range of uids allocated for a user. 29 */ 30 public static final int PER_USER_RANGE = 100000; 31 32 /** @hide A user id to indicate all users on the device */ 33 public static final int USER_ALL = -1; 34 35 /** @hide A user handle to indicate all users on the device */ 36 public static final UserHandle ALL = new UserHandle(USER_ALL); 37 38 /** @hide A user id to indicate the currently active user */ 39 public static final int USER_CURRENT = -2; 40 41 /** @hide A user handle to indicate the current user of the device */ 42 public static final UserHandle CURRENT = new UserHandle(USER_CURRENT); 43 44 /** @hide A user id to indicate that we would like to send to the current 45 * user, but if this is calling from a user process then we will send it 46 * to the caller's user instead of failing with a security exception */ 47 public static final int USER_CURRENT_OR_SELF = -3; 48 49 /** @hide A user handle to indicate that we would like to send to the current 50 * user, but if this is calling from a user process then we will send it 51 * to the caller's user instead of failing with a security exception */ 52 public static final UserHandle CURRENT_OR_SELF = new UserHandle(USER_CURRENT_OR_SELF); 53 54 /** @hide An undefined user id */ 55 public static final int USER_NULL = -10000; 56 57 /** 58 * @hide A user id constant to indicate the "owner" user of the device 59 * @deprecated Consider using either {@link UserHandle#USER_SYSTEM} constant or 60 * check the target user's flag {@link android.content.pm.UserInfo#isAdmin}. 61 */ 62 public static final int USER_OWNER = 0; 63 64 /** 65 * @hide A user handle to indicate the primary/owner user of the device 66 * @deprecated Consider using either {@link UserHandle#SYSTEM} constant or 67 * check the target user's flag {@link android.content.pm.UserInfo#isAdmin}. 68 */ 69 public static final UserHandle OWNER = new UserHandle(USER_OWNER); 70 71 /** @hide A user id constant to indicate the "system" user of the device */ 72 public static final int USER_SYSTEM = 0; 73 74 /** @hide A user handle to indicate the "system" user of the device */ 75 public static final UserHandle SYSTEM = new UserHandle(USER_SYSTEM); 76 77 /** 78 * @hide Enable multi-user related side effects. Set this to false if 79 * there are problems with single user use-cases. 80 */ 81 public static final boolean MU_ENABLED = true; 82 83 final int mHandle; 84 85 /** 86 * Checks to see if the user id is the same for the two uids, i.e., they belong to the same 87 * user. 88 * @hide 89 */ 90 public static boolean isSameUser(int uid1, int uid2) { 91 return getUserId(uid1) == getUserId(uid2); 92 } 93 94 /** 95 * Checks to see if both uids are referring to the same app id, ignoring the user id part of the 96 * uids. 97 * @param uid1 uid to compare 98 * @param uid2 other uid to compare 99 * @return whether the appId is the same for both uids 100 * @hide 101 */ 102 public static boolean isSameApp(int uid1, int uid2) { 103 return getAppId(uid1) == getAppId(uid2); 104 } 105 106 /** @hide */ 107 public static boolean isIsolated(int uid) { 108 if (uid > 0) { 109 final int appId = getAppId(uid); 110 return appId >= Process.FIRST_ISOLATED_UID && appId <= Process.LAST_ISOLATED_UID; 111 } else { 112 return false; 113 } 114 } 115 116 /** @hide */ 117 public static boolean isApp(int uid) { 118 if (uid > 0) { 119 final int appId = getAppId(uid); 120 return appId >= Process.FIRST_APPLICATION_UID && appId <= Process.LAST_APPLICATION_UID; 121 } else { 122 return false; 123 } 124 } 125 126 /** 127 * Returns the user id for a given uid. 128 * @hide 129 */ 130 public static int getUserId(int uid) { 131 if (MU_ENABLED) { 132 return uid / PER_USER_RANGE; 133 } else { 134 return UserHandle.USER_SYSTEM; 135 } 136 } 137 138 /** @hide */ 139 public static int getCallingUserId() { 140 return getUserId(Binder.getCallingUid()); 141 } 142 143 /** @hide */ 144 public static UserHandle of(int userId) { 145 return userId == USER_SYSTEM ? SYSTEM : new UserHandle(userId); 146 } 147 148 /** 149 * Returns the uid that is composed from the userId and the appId. 150 * @hide 151 */ 152 public static int getUid(int userId, int appId) { 153 if (MU_ENABLED) { 154 return userId * PER_USER_RANGE + (appId % PER_USER_RANGE); 155 } else { 156 return appId; 157 } 158 } 159 160 /** 161 * Returns the app id (or base uid) for a given uid, stripping out the user id from it. 162 * @hide 163 */ 164 public static int getAppId(int uid) { 165 return uid % PER_USER_RANGE; 166 } 167 168 /** 169 * Returns the gid shared between all apps with this userId. 170 * @hide 171 */ 172 public static int getUserGid(int userId) { 173 return getUid(userId, Process.SHARED_USER_GID); 174 } 175 176 /** 177 * Returns the shared app gid for a given uid or appId. 178 * @hide 179 */ 180 public static int getSharedAppGid(int id) { 181 return Process.FIRST_SHARED_APPLICATION_GID + (id % PER_USER_RANGE) 182 - Process.FIRST_APPLICATION_UID; 183 } 184 185 /** 186 * Returns the app id for a given shared app gid. Returns -1 if the ID is invalid. 187 * @hide 188 */ 189 public static int getAppIdFromSharedAppGid(int gid) { 190 final int appId = getAppId(gid) + Process.FIRST_APPLICATION_UID 191 - Process.FIRST_SHARED_APPLICATION_GID; 192 if (appId < 0 || appId >= Process.FIRST_SHARED_APPLICATION_GID) { 193 return -1; 194 } 195 return appId; 196 } 197 198 /** 199 * Generate a text representation of the uid, breaking out its individual 200 * components -- user, app, isolated, etc. 201 * @hide 202 */ 203 public static void formatUid(StringBuilder sb, int uid) { 204 if (uid < Process.FIRST_APPLICATION_UID) { 205 sb.append(uid); 206 } else { 207 sb.append('u'); 208 sb.append(getUserId(uid)); 209 final int appId = getAppId(uid); 210 if (appId >= Process.FIRST_ISOLATED_UID && appId <= Process.LAST_ISOLATED_UID) { 211 sb.append('i'); 212 sb.append(appId - Process.FIRST_ISOLATED_UID); 213 } else if (appId >= Process.FIRST_APPLICATION_UID) { 214 sb.append('a'); 215 sb.append(appId - Process.FIRST_APPLICATION_UID); 216 } else { 217 sb.append('s'); 218 sb.append(appId); 219 } 220 } 221 } 222 223 /** 224 * Generate a text representation of the uid, breaking out its individual 225 * components -- user, app, isolated, etc. 226 * @hide 227 */ 228 public static String formatUid(int uid) { 229 StringBuilder sb = new StringBuilder(); 230 formatUid(sb, uid); 231 return sb.toString(); 232 } 233 234 /** 235 * Generate a text representation of the uid, breaking out its individual 236 * components -- user, app, isolated, etc. 237 * @hide 238 */ 239 public static void formatUid(PrintWriter pw, int uid) { 240 if (uid < Process.FIRST_APPLICATION_UID) { 241 pw.print(uid); 242 } else { 243 pw.print('u'); 244 pw.print(getUserId(uid)); 245 final int appId = getAppId(uid); 246 if (appId >= Process.FIRST_ISOLATED_UID && appId <= Process.LAST_ISOLATED_UID) { 247 pw.print('i'); 248 pw.print(appId - Process.FIRST_ISOLATED_UID); 249 } else if (appId >= Process.FIRST_APPLICATION_UID) { 250 pw.print('a'); 251 pw.print(appId - Process.FIRST_APPLICATION_UID); 252 } else { 253 pw.print('s'); 254 pw.print(appId); 255 } 256 } 257 } 258 259 /** 260 * Returns the user id of the current process 261 * @return user id of the current process 262 * @hide 263 */ 264 @SystemApi 265 public static int myUserId() { 266 return getUserId(Process.myUid()); 267 } 268 269 /** 270 * Returns true if this UserHandle refers to the owner user; false otherwise. 271 * @return true if this UserHandle refers to the owner user; false otherwise. 272 * @hide 273 * TODO: find an alternative to this Api. 274 */ 275 @SystemApi 276 public boolean isOwner() { 277 return this.equals(OWNER); 278 } 279 280 /** @hide */ 281 public UserHandle(int h) { 282 mHandle = h; 283 } 284 285 /** 286 * Returns the userId stored in this UserHandle. 287 * @hide 288 */ 289 @SystemApi 290 public int getIdentifier() { 291 return mHandle; 292 } 293 294 @Override 295 public String toString() { 296 return "UserHandle{" + mHandle + "}"; 297 } 298 299 @Override 300 public boolean equals(Object obj) { 301 try { 302 if (obj != null) { 303 UserHandle other = (UserHandle)obj; 304 return mHandle == other.mHandle; 305 } 306 } catch (ClassCastException e) { 307 } 308 return false; 309 } 310 311 @Override 312 public int hashCode() { 313 return mHandle; 314 } 315 316 public int describeContents() { 317 return 0; 318 } 319 320 public void writeToParcel(Parcel out, int flags) { 321 out.writeInt(mHandle); 322 } 323 324 /** 325 * Write a UserHandle to a Parcel, handling null pointers. Must be 326 * read with {@link #readFromParcel(Parcel)}. 327 * 328 * @param h The UserHandle to be written. 329 * @param out The Parcel in which the UserHandle will be placed. 330 * 331 * @see #readFromParcel(Parcel) 332 */ 333 public static void writeToParcel(UserHandle h, Parcel out) { 334 if (h != null) { 335 h.writeToParcel(out, 0); 336 } else { 337 out.writeInt(USER_NULL); 338 } 339 } 340 341 /** 342 * Read a UserHandle from a Parcel that was previously written 343 * with {@link #writeToParcel(UserHandle, Parcel)}, returning either 344 * a null or new object as appropriate. 345 * 346 * @param in The Parcel from which to read the UserHandle 347 * @return Returns a new UserHandle matching the previously written 348 * object, or null if a null had been written. 349 * 350 * @see #writeToParcel(UserHandle, Parcel) 351 */ 352 public static UserHandle readFromParcel(Parcel in) { 353 int h = in.readInt(); 354 return h != USER_NULL ? new UserHandle(h) : null; 355 } 356 357 public static final Parcelable.Creator<UserHandle> CREATOR 358 = new Parcelable.Creator<UserHandle>() { 359 public UserHandle createFromParcel(Parcel in) { 360 return new UserHandle(in); 361 } 362 363 public UserHandle[] newArray(int size) { 364 return new UserHandle[size]; 365 } 366 }; 367 368 /** 369 * Instantiate a new UserHandle from the data in a Parcel that was 370 * previously written with {@link #writeToParcel(Parcel, int)}. Note that you 371 * must not use this with data written by 372 * {@link #writeToParcel(UserHandle, Parcel)} since it is not possible 373 * to handle a null UserHandle here. 374 * 375 * @param in The Parcel containing the previously written UserHandle, 376 * positioned at the location in the buffer where it was written. 377 */ 378 public UserHandle(Parcel in) { 379 mHandle = in.readInt(); 380 } 381} 382