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