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      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.AppIdInt;
     20 import android.annotation.SystemApi;
     21 import android.annotation.TestApi;
     22 import android.annotation.UserIdInt;
     23 
     24 import java.io.PrintWriter;
     25 
     26 /**
     27  * Representation of a user on the device.
     28  */
     29 public final class UserHandle implements Parcelable {
     30     /**
     31      * @hide Range of uids allocated for a user.
     32      */
     33     public static final int PER_USER_RANGE = 100000;
     34 
     35     /** @hide A user id to indicate all users on the device */
     36     public static final @UserIdInt int USER_ALL = -1;
     37 
     38     /** @hide A user handle to indicate all users on the device */
     39     public static final UserHandle ALL = new UserHandle(USER_ALL);
     40 
     41     /** @hide A user id to indicate the currently active user */
     42     public static final @UserIdInt int USER_CURRENT = -2;
     43 
     44     /** @hide A user handle to indicate the current user of the device */
     45     public static final UserHandle CURRENT = new UserHandle(USER_CURRENT);
     46 
     47     /** @hide A user id 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 with a security exception */
     50     public static final @UserIdInt int USER_CURRENT_OR_SELF = -3;
     51 
     52     /** @hide A user handle to indicate that we would like to send to the current
     53      *  user, but if this is calling from a user process then we will send it
     54      *  to the caller's user instead of failing with a security exception */
     55     public static final UserHandle CURRENT_OR_SELF = new UserHandle(USER_CURRENT_OR_SELF);
     56 
     57     /** @hide An undefined user id */
     58     public static final @UserIdInt int USER_NULL = -10000;
     59 
     60     /**
     61      * @hide A user id constant to indicate the "owner" user of the device
     62      * @deprecated Consider using either {@link UserHandle#USER_SYSTEM} constant or
     63      * check the target user's flag {@link android.content.pm.UserInfo#isAdmin}.
     64      */
     65     public static final @UserIdInt int USER_OWNER = 0;
     66 
     67     /**
     68      * @hide A user handle to indicate the primary/owner user of the device
     69      * @deprecated Consider using either {@link UserHandle#SYSTEM} constant or
     70      * check the target user's flag {@link android.content.pm.UserInfo#isAdmin}.
     71      */
     72     public static final UserHandle OWNER = new UserHandle(USER_OWNER);
     73 
     74     /** @hide A user id constant to indicate the "system" user of the device */
     75     public static final @UserIdInt int USER_SYSTEM = 0;
     76 
     77     /** @hide A user serial constant to indicate the "system" user of the device */
     78     public static final int USER_SERIAL_SYSTEM = 0;
     79 
     80     /** @hide A user handle to indicate the "system" user of the device */
     81     public static final UserHandle SYSTEM = new UserHandle(USER_SYSTEM);
     82 
     83     /**
     84      * @hide Enable multi-user related side effects. Set this to false if
     85      * there are problems with single user use-cases.
     86      */
     87     public static final boolean MU_ENABLED = true;
     88 
     89     final int mHandle;
     90 
     91     /**
     92      * Checks to see if the user id is the same for the two uids, i.e., they belong to the same
     93      * user.
     94      * @hide
     95      */
     96     public static boolean isSameUser(int uid1, int uid2) {
     97         return getUserId(uid1) == getUserId(uid2);
     98     }
     99 
    100     /**
    101      * Checks to see if both uids are referring to the same app id, ignoring the user id part of the
    102      * uids.
    103      * @param uid1 uid to compare
    104      * @param uid2 other uid to compare
    105      * @return whether the appId is the same for both uids
    106      * @hide
    107      */
    108     public static boolean isSameApp(int uid1, int uid2) {
    109         return getAppId(uid1) == getAppId(uid2);
    110     }
    111 
    112     /** @hide */
    113     public static boolean isIsolated(int uid) {
    114         if (uid > 0) {
    115             final int appId = getAppId(uid);
    116             return appId >= Process.FIRST_ISOLATED_UID && appId <= Process.LAST_ISOLATED_UID;
    117         } else {
    118             return false;
    119         }
    120     }
    121 
    122     /** @hide */
    123     public static boolean isApp(int uid) {
    124         if (uid > 0) {
    125             final int appId = getAppId(uid);
    126             return appId >= Process.FIRST_APPLICATION_UID && appId <= Process.LAST_APPLICATION_UID;
    127         } else {
    128             return false;
    129         }
    130     }
    131 
    132     /**
    133      * Returns the user for a given uid.
    134      * @param uid A uid for an application running in a particular user.
    135      * @return A {@link UserHandle} for that user.
    136      */
    137     public static UserHandle getUserHandleForUid(int uid) {
    138         return of(getUserId(uid));
    139     }
    140 
    141     /**
    142      * Returns the user id for a given uid.
    143      * @hide
    144      */
    145     public static @UserIdInt int getUserId(int uid) {
    146         if (MU_ENABLED) {
    147             return uid / PER_USER_RANGE;
    148         } else {
    149             return UserHandle.USER_SYSTEM;
    150         }
    151     }
    152 
    153     /** @hide */
    154     public static @UserIdInt int getCallingUserId() {
    155         return getUserId(Binder.getCallingUid());
    156     }
    157 
    158     /** @hide */
    159     @SystemApi
    160     public static UserHandle of(@UserIdInt int userId) {
    161         return userId == USER_SYSTEM ? SYSTEM : new UserHandle(userId);
    162     }
    163 
    164     /**
    165      * Returns the uid that is composed from the userId and the appId.
    166      * @hide
    167      */
    168     public static int getUid(@UserIdInt int userId, @AppIdInt int appId) {
    169         if (MU_ENABLED) {
    170             return userId * PER_USER_RANGE + (appId % PER_USER_RANGE);
    171         } else {
    172             return appId;
    173         }
    174     }
    175 
    176     /**
    177      * Returns the app id (or base uid) for a given uid, stripping out the user id from it.
    178      * @hide
    179      */
    180     @TestApi
    181     public static @AppIdInt int getAppId(int uid) {
    182         return uid % PER_USER_RANGE;
    183     }
    184 
    185     /**
    186      * Returns the gid shared between all apps with this userId.
    187      * @hide
    188      */
    189     public static int getUserGid(@UserIdInt int userId) {
    190         return getUid(userId, Process.SHARED_USER_GID);
    191     }
    192 
    193     /**
    194      * Returns the shared app gid for a given uid or appId.
    195      * @hide
    196      */
    197     public static int getSharedAppGid(int id) {
    198         return Process.FIRST_SHARED_APPLICATION_GID + (id % PER_USER_RANGE)
    199                 - Process.FIRST_APPLICATION_UID;
    200     }
    201 
    202     /**
    203      * Returns the app id for a given shared app gid. Returns -1 if the ID is invalid.
    204      * @hide
    205      */
    206     public static @AppIdInt int getAppIdFromSharedAppGid(int gid) {
    207         final int appId = getAppId(gid) + Process.FIRST_APPLICATION_UID
    208                 - Process.FIRST_SHARED_APPLICATION_GID;
    209         if (appId < 0 || appId >= Process.FIRST_SHARED_APPLICATION_GID) {
    210             return -1;
    211         }
    212         return appId;
    213     }
    214 
    215     /**
    216      * Generate a text representation of the uid, breaking out its individual
    217      * components -- user, app, isolated, etc.
    218      * @hide
    219      */
    220     public static void formatUid(StringBuilder sb, int uid) {
    221         if (uid < Process.FIRST_APPLICATION_UID) {
    222             sb.append(uid);
    223         } else {
    224             sb.append('u');
    225             sb.append(getUserId(uid));
    226             final int appId = getAppId(uid);
    227             if (appId >= Process.FIRST_ISOLATED_UID && appId <= Process.LAST_ISOLATED_UID) {
    228                 sb.append('i');
    229                 sb.append(appId - Process.FIRST_ISOLATED_UID);
    230             } else if (appId >= Process.FIRST_APPLICATION_UID) {
    231                 sb.append('a');
    232                 sb.append(appId - Process.FIRST_APPLICATION_UID);
    233             } else {
    234                 sb.append('s');
    235                 sb.append(appId);
    236             }
    237         }
    238     }
    239 
    240     /**
    241      * Generate a text representation of the uid, breaking out its individual
    242      * components -- user, app, isolated, etc.
    243      * @hide
    244      */
    245     public static String formatUid(int uid) {
    246         StringBuilder sb = new StringBuilder();
    247         formatUid(sb, uid);
    248         return sb.toString();
    249     }
    250 
    251     /**
    252      * Generate a text representation of the uid, breaking out its individual
    253      * components -- user, app, isolated, etc.
    254      * @hide
    255      */
    256     public static void formatUid(PrintWriter pw, int uid) {
    257         if (uid < Process.FIRST_APPLICATION_UID) {
    258             pw.print(uid);
    259         } else {
    260             pw.print('u');
    261             pw.print(getUserId(uid));
    262             final int appId = getAppId(uid);
    263             if (appId >= Process.FIRST_ISOLATED_UID && appId <= Process.LAST_ISOLATED_UID) {
    264                 pw.print('i');
    265                 pw.print(appId - Process.FIRST_ISOLATED_UID);
    266             } else if (appId >= Process.FIRST_APPLICATION_UID) {
    267                 pw.print('a');
    268                 pw.print(appId - Process.FIRST_APPLICATION_UID);
    269             } else {
    270                 pw.print('s');
    271                 pw.print(appId);
    272             }
    273         }
    274     }
    275 
    276     /** @hide */
    277     public static @UserIdInt int parseUserArg(String arg) {
    278         int userId;
    279         if ("all".equals(arg)) {
    280             userId = UserHandle.USER_ALL;
    281         } else if ("current".equals(arg) || "cur".equals(arg)) {
    282             userId = UserHandle.USER_CURRENT;
    283         } else {
    284             try {
    285                 userId = Integer.parseInt(arg);
    286             } catch (NumberFormatException e) {
    287                 throw new IllegalArgumentException("Bad user number: " + arg);
    288             }
    289         }
    290         return userId;
    291     }
    292 
    293     /**
    294      * Returns the user id of the current process
    295      * @return user id of the current process
    296      * @hide
    297      */
    298     @SystemApi
    299     public static @UserIdInt int myUserId() {
    300         return getUserId(Process.myUid());
    301     }
    302 
    303     /**
    304      * Returns true if this UserHandle refers to the owner user; false otherwise.
    305      * @return true if this UserHandle refers to the owner user; false otherwise.
    306      * @hide
    307      * @deprecated please use {@link #isSystem()} or check for
    308      * {@link android.content.pm.UserInfo#isPrimary()}
    309      * {@link android.content.pm.UserInfo#isAdmin()} based on your particular use case.
    310      */
    311     @SystemApi
    312     public boolean isOwner() {
    313         return this.equals(OWNER);
    314     }
    315 
    316     /**
    317      * @return true if this UserHandle refers to the system user; false otherwise.
    318      * @hide
    319      */
    320     @SystemApi
    321     public boolean isSystem() {
    322         return this.equals(SYSTEM);
    323     }
    324 
    325     /** @hide */
    326     public UserHandle(int h) {
    327         mHandle = h;
    328     }
    329 
    330     /**
    331      * Returns the userId stored in this UserHandle.
    332      * @hide
    333      */
    334     @SystemApi
    335     public @UserIdInt int getIdentifier() {
    336         return mHandle;
    337     }
    338 
    339     @Override
    340     public String toString() {
    341         return "UserHandle{" + mHandle + "}";
    342     }
    343 
    344     @Override
    345     public boolean equals(Object obj) {
    346         try {
    347             if (obj != null) {
    348                 UserHandle other = (UserHandle)obj;
    349                 return mHandle == other.mHandle;
    350             }
    351         } catch (ClassCastException e) {
    352         }
    353         return false;
    354     }
    355 
    356     @Override
    357     public int hashCode() {
    358         return mHandle;
    359     }
    360 
    361     public int describeContents() {
    362         return 0;
    363     }
    364 
    365     public void writeToParcel(Parcel out, int flags) {
    366         out.writeInt(mHandle);
    367     }
    368 
    369     /**
    370      * Write a UserHandle to a Parcel, handling null pointers.  Must be
    371      * read with {@link #readFromParcel(Parcel)}.
    372      *
    373      * @param h The UserHandle to be written.
    374      * @param out The Parcel in which the UserHandle will be placed.
    375      *
    376      * @see #readFromParcel(Parcel)
    377      */
    378     public static void writeToParcel(UserHandle h, Parcel out) {
    379         if (h != null) {
    380             h.writeToParcel(out, 0);
    381         } else {
    382             out.writeInt(USER_NULL);
    383         }
    384     }
    385 
    386     /**
    387      * Read a UserHandle from a Parcel that was previously written
    388      * with {@link #writeToParcel(UserHandle, Parcel)}, returning either
    389      * a null or new object as appropriate.
    390      *
    391      * @param in The Parcel from which to read the UserHandle
    392      * @return Returns a new UserHandle matching the previously written
    393      * object, or null if a null had been written.
    394      *
    395      * @see #writeToParcel(UserHandle, Parcel)
    396      */
    397     public static UserHandle readFromParcel(Parcel in) {
    398         int h = in.readInt();
    399         return h != USER_NULL ? new UserHandle(h) : null;
    400     }
    401 
    402     public static final Parcelable.Creator<UserHandle> CREATOR
    403             = new Parcelable.Creator<UserHandle>() {
    404         public UserHandle createFromParcel(Parcel in) {
    405             return new UserHandle(in);
    406         }
    407 
    408         public UserHandle[] newArray(int size) {
    409             return new UserHandle[size];
    410         }
    411     };
    412 
    413     /**
    414      * Instantiate a new UserHandle from the data in a Parcel that was
    415      * previously written with {@link #writeToParcel(Parcel, int)}.  Note that you
    416      * must not use this with data written by
    417      * {@link #writeToParcel(UserHandle, Parcel)} since it is not possible
    418      * to handle a null UserHandle here.
    419      *
    420      * @param in The Parcel containing the previously written UserHandle,
    421      * positioned at the location in the buffer where it was written.
    422      */
    423     public UserHandle(Parcel in) {
    424         mHandle = in.readInt();
    425     }
    426 }
    427