UserHandle.java revision f4216d30cd768638eebdb4124abae95bdf5b3597
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; 20import android.util.SparseArray; 21 22import java.io.PrintWriter; 23 24/** 25 * Representation of a user on the device. 26 */ 27public 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. 183 * @hide 184 */ 185 public static final int getAppIdFromSharedAppGid(int gid) { 186 final int noUserGid = getAppId(gid); 187 if (noUserGid < Process.FIRST_SHARED_APPLICATION_GID || 188 noUserGid > Process.LAST_SHARED_APPLICATION_GID) { 189 throw new IllegalArgumentException(Integer.toString(gid) + " is not a shared app gid"); 190 } 191 return (noUserGid + Process.FIRST_APPLICATION_UID) - Process.FIRST_SHARED_APPLICATION_GID; 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 void formatUid(PrintWriter pw, int uid) { 225 if (uid < Process.FIRST_APPLICATION_UID) { 226 pw.print(uid); 227 } else { 228 pw.print('u'); 229 pw.print(getUserId(uid)); 230 final int appId = getAppId(uid); 231 if (appId >= Process.FIRST_ISOLATED_UID && appId <= Process.LAST_ISOLATED_UID) { 232 pw.print('i'); 233 pw.print(appId - Process.FIRST_ISOLATED_UID); 234 } else if (appId >= Process.FIRST_APPLICATION_UID) { 235 pw.print('a'); 236 pw.print(appId - Process.FIRST_APPLICATION_UID); 237 } else { 238 pw.print('s'); 239 pw.print(appId); 240 } 241 } 242 } 243 244 /** 245 * Returns the user id of the current process 246 * @return user id of the current process 247 * @hide 248 */ 249 @SystemApi 250 public static final int myUserId() { 251 return getUserId(Process.myUid()); 252 } 253 254 /** 255 * Returns true if this UserHandle refers to the owner user; false otherwise. 256 * @return true if this UserHandle refers to the owner user; false otherwise. 257 * @hide 258 */ 259 @SystemApi 260 public final boolean isOwner() { 261 return this.equals(OWNER); 262 } 263 264 /** @hide */ 265 public UserHandle(int h) { 266 mHandle = h; 267 } 268 269 /** 270 * Returns the userId stored in this UserHandle. 271 * @hide 272 */ 273 @SystemApi 274 public int getIdentifier() { 275 return mHandle; 276 } 277 278 @Override 279 public String toString() { 280 return "UserHandle{" + mHandle + "}"; 281 } 282 283 @Override 284 public boolean equals(Object obj) { 285 try { 286 if (obj != null) { 287 UserHandle other = (UserHandle)obj; 288 return mHandle == other.mHandle; 289 } 290 } catch (ClassCastException e) { 291 } 292 return false; 293 } 294 295 @Override 296 public int hashCode() { 297 return mHandle; 298 } 299 300 public int describeContents() { 301 return 0; 302 } 303 304 public void writeToParcel(Parcel out, int flags) { 305 out.writeInt(mHandle); 306 } 307 308 /** 309 * Write a UserHandle to a Parcel, handling null pointers. Must be 310 * read with {@link #readFromParcel(Parcel)}. 311 * 312 * @param h The UserHandle to be written. 313 * @param out The Parcel in which the UserHandle will be placed. 314 * 315 * @see #readFromParcel(Parcel) 316 */ 317 public static void writeToParcel(UserHandle h, Parcel out) { 318 if (h != null) { 319 h.writeToParcel(out, 0); 320 } else { 321 out.writeInt(USER_NULL); 322 } 323 } 324 325 /** 326 * Read a UserHandle from a Parcel that was previously written 327 * with {@link #writeToParcel(UserHandle, Parcel)}, returning either 328 * a null or new object as appropriate. 329 * 330 * @param in The Parcel from which to read the UserHandle 331 * @return Returns a new UserHandle matching the previously written 332 * object, or null if a null had been written. 333 * 334 * @see #writeToParcel(UserHandle, Parcel) 335 */ 336 public static UserHandle readFromParcel(Parcel in) { 337 int h = in.readInt(); 338 return h != USER_NULL ? new UserHandle(h) : null; 339 } 340 341 public static final Parcelable.Creator<UserHandle> CREATOR 342 = new Parcelable.Creator<UserHandle>() { 343 public UserHandle createFromParcel(Parcel in) { 344 return new UserHandle(in); 345 } 346 347 public UserHandle[] newArray(int size) { 348 return new UserHandle[size]; 349 } 350 }; 351 352 /** 353 * Instantiate a new UserHandle from the data in a Parcel that was 354 * previously written with {@link #writeToParcel(Parcel, int)}. Note that you 355 * must not use this with data written by 356 * {@link #writeToParcel(UserHandle, Parcel)} since it is not possible 357 * to handle a null UserHandle here. 358 * 359 * @param in The Parcel containing the previously written UserHandle, 360 * positioned at the location in the buffer where it was written. 361 */ 362 public UserHandle(Parcel in) { 363 mHandle = in.readInt(); 364 } 365} 366