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