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