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 { 172 sb.append('a'); 173 sb.append(appId); 174 } 175 } 176 } 177 178 /** 179 * Generate a text representation of the uid, breaking out its individual 180 * components -- user, app, isolated, etc. 181 * @hide 182 */ 183 public static void formatUid(PrintWriter pw, int uid) { 184 if (uid < Process.FIRST_APPLICATION_UID) { 185 pw.print(uid); 186 } else { 187 pw.print('u'); 188 pw.print(getUserId(uid)); 189 final int appId = getAppId(uid); 190 if (appId >= Process.FIRST_ISOLATED_UID && appId <= Process.LAST_ISOLATED_UID) { 191 pw.print('i'); 192 pw.print(appId - Process.FIRST_ISOLATED_UID); 193 } else { 194 pw.print('a'); 195 pw.print(appId); 196 } 197 } 198 } 199 200 /** 201 * Returns the user id of the current process 202 * @return user id of the current process 203 * @hide 204 */ 205 public static final int myUserId() { 206 return getUserId(Process.myUid()); 207 } 208 209 /** @hide */ 210 public UserHandle(int h) { 211 mHandle = h; 212 } 213 214 /** @hide */ 215 public int getIdentifier() { 216 return mHandle; 217 } 218 219 @Override 220 public String toString() { 221 return "UserHandle{" + mHandle + "}"; 222 } 223 224 @Override 225 public boolean equals(Object obj) { 226 try { 227 if (obj != null) { 228 UserHandle other = (UserHandle)obj; 229 return mHandle == other.mHandle; 230 } 231 } catch (ClassCastException e) { 232 } 233 return false; 234 } 235 236 @Override 237 public int hashCode() { 238 return mHandle; 239 } 240 241 public int describeContents() { 242 return 0; 243 } 244 245 public void writeToParcel(Parcel out, int flags) { 246 out.writeInt(mHandle); 247 } 248 249 /** 250 * Write a UserHandle to a Parcel, handling null pointers. Must be 251 * read with {@link #readFromParcel(Parcel)}. 252 * 253 * @param h The UserHandle to be written. 254 * @param out The Parcel in which the UserHandle will be placed. 255 * 256 * @see #readFromParcel(Parcel) 257 */ 258 public static void writeToParcel(UserHandle h, Parcel out) { 259 if (h != null) { 260 h.writeToParcel(out, 0); 261 } else { 262 out.writeInt(USER_NULL); 263 } 264 } 265 266 /** 267 * Read a UserHandle from a Parcel that was previously written 268 * with {@link #writeToParcel(UserHandle, Parcel)}, returning either 269 * a null or new object as appropriate. 270 * 271 * @param in The Parcel from which to read the UserHandle 272 * @return Returns a new UserHandle matching the previously written 273 * object, or null if a null had been written. 274 * 275 * @see #writeToParcel(UserHandle, Parcel) 276 */ 277 public static UserHandle readFromParcel(Parcel in) { 278 int h = in.readInt(); 279 return h != USER_NULL ? new UserHandle(h) : null; 280 } 281 282 public static final Parcelable.Creator<UserHandle> CREATOR 283 = new Parcelable.Creator<UserHandle>() { 284 public UserHandle createFromParcel(Parcel in) { 285 return new UserHandle(in); 286 } 287 288 public UserHandle[] newArray(int size) { 289 return new UserHandle[size]; 290 } 291 }; 292 293 /** 294 * Instantiate a new UserHandle from the data in a Parcel that was 295 * previously written with {@link #writeToParcel(Parcel, int)}. Note that you 296 * must not use this with data written by 297 * {@link #writeToParcel(UserHandle, Parcel)} since it is not possible 298 * to handle a null UserHandle here. 299 * 300 * @param in The Parcel containing the previously written UserHandle, 301 * positioned at the location in the buffer where it was written. 302 */ 303 public UserHandle(Parcel in) { 304 mHandle = in.readInt(); 305 } 306 } 307
