/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.os;
import android.annotation.SystemApi;
import android.util.SparseArray;
import java.io.PrintWriter;
import java.util.HashMap;
/**
* Representation of a user on the device.
*/
public final class UserHandle implements Parcelable {
/**
* @hide Range of uids allocated for a user.
*/
public static final int PER_USER_RANGE = 100000;
/** @hide A user id to indicate all users on the device */
public static final int USER_ALL = -1;
/** @hide A user handle to indicate all users on the device */
public static final UserHandle ALL = new UserHandle(USER_ALL);
/** @hide A user id to indicate the currently active user */
public static final int USER_CURRENT = -2;
/** @hide A user handle to indicate the current user of the device */
public static final UserHandle CURRENT = new UserHandle(USER_CURRENT);
/** @hide A user id to indicate that we would like to send to the current
* user, but if this is calling from a user process then we will send it
* to the caller's user instead of failing with a security exception */
public static final int USER_CURRENT_OR_SELF = -3;
/** @hide A user handle to indicate that we would like to send to the current
* user, but if this is calling from a user process then we will send it
* to the caller's user instead of failing with a security exception */
public static final UserHandle CURRENT_OR_SELF = new UserHandle(USER_CURRENT_OR_SELF);
/** @hide An undefined user id */
public static final int USER_NULL = -10000;
/** @hide A user id constant to indicate the "owner" user of the device */
public static final int USER_OWNER = 0;
/** @hide A user handle to indicate the primary/owner user of the device */
public static final UserHandle OWNER = new UserHandle(USER_OWNER);
/**
* @hide Enable multi-user related side effects. Set this to false if
* there are problems with single user use-cases.
*/
public static final boolean MU_ENABLED = true;
final int mHandle;
private static final SparseArray<UserHandle> userHandles = new SparseArray<UserHandle>();
/**
* Checks to see if the user id is the same for the two uids, i.e., they belong to the same
* user.
* @hide
*/
public static final boolean isSameUser(int uid1, int uid2) {
return getUserId(uid1) == getUserId(uid2);
}
/**
* Checks to see if both uids are referring to the same app id, ignoring the user id part of the
* uids.
* @param uid1 uid to compare
* @param uid2 other uid to compare
* @return whether the appId is the same for both uids
* @hide
*/
public static final boolean isSameApp(int uid1, int uid2) {
return getAppId(uid1) == getAppId(uid2);
}
/** @hide */
public static final boolean isIsolated(int uid) {
if (uid > 0) {
final int appId = getAppId(uid);
return appId >= Process.FIRST_ISOLATED_UID && appId <= Process.LAST_ISOLATED_UID;
} else {
return false;
}
}
/** @hide */
public static boolean isApp(int uid) {
if (uid > 0) {
final int appId = getAppId(uid);
return appId >= Process.FIRST_APPLICATION_UID && appId <= Process.LAST_APPLICATION_UID;
} else {
return false;
}
}
/**
* Returns the user id for a given uid.
* @hide
*/
public static final int getUserId(int uid) {
if (MU_ENABLED) {
return uid / PER_USER_RANGE;
} else {
return 0;
}
}
/** @hide */
public static final int getCallingUserId() {
return getUserId(Binder.getCallingUid());
}
/** @hide */
public static final UserHandle getCallingUserHandle() {
int userId = getUserId(Binder.getCallingUid());
UserHandle userHandle = userHandles.get(userId);
// Intentionally not synchronized to save time
if (userHandle == null) {
userHandle = new UserHandle(userId);
userHandles.put(userId, userHandle);
}
return userHandle;
}
/**
* Returns the uid that is composed from the userId and the appId.
* @hide
*/
public static final int getUid(int userId, int appId) {
if (MU_ENABLED) {
return userId * PER_USER_RANGE + (appId % PER_USER_RANGE);
} else {
return appId;
}
}
/**
* Returns the app id (or base uid) for a given uid, stripping out the user id from it.
* @hide
*/
public static final int getAppId(int uid) {
return uid % PER_USER_RANGE;
}
/**
* Returns the gid shared between all apps with this userId.
* @hide
*/
public static final int getUserGid(int userId) {
return getUid(userId, Process.SHARED_USER_GID);
}
/**
* Returns the shared app gid for a given uid or appId.
* @hide
*/
public static final int getSharedAppGid(int id) {
return Process.FIRST_SHARED_APPLICATION_GID + (id % PER_USER_RANGE)
- Process.FIRST_APPLICATION_UID;
}
/**
* Generate a text representation of the uid, breaking out its individual
* components -- user, app, isolated, etc.
* @hide
*/
public static void formatUid(StringBuilder sb, int uid) {
if (uid < Process.FIRST_APPLICATION_UID) {
sb.append(uid);
} else {
sb.append('u');
sb.append(getUserId(uid));
final int appId = getAppId(uid);
if (appId >= Process.FIRST_ISOLATED_UID && appId <= Process.LAST_ISOLATED_UID) {
sb.append('i');
sb.append(appId - Process.FIRST_ISOLATED_UID);
} else if (appId >= Process.FIRST_APPLICATION_UID) {
sb.append('a');
sb.append(appId - Process.FIRST_APPLICATION_UID);
} else {
sb.append('s');
sb.append(appId);
}
}
}
/**
* Generate a text representation of the uid, breaking out its individual
* components -- user, app, isolated, etc.
* @hide
*/
public static void formatUid(PrintWriter pw, int uid) {
if (uid < Process.FIRST_APPLICATION_UID) {
pw.print(uid);
} else {
pw.print('u');
pw.print(getUserId(uid));
final int appId = getAppId(uid);
if (appId >= Process.FIRST_ISOLATED_UID && appId <= Process.LAST_ISOLATED_UID) {
pw.print('i');
pw.print(appId - Process.FIRST_ISOLATED_UID);
} else if (appId >= Process.FIRST_APPLICATION_UID) {
pw.print('a');
pw.print(appId - Process.FIRST_APPLICATION_UID);
} else {
pw.print('s');
pw.print(appId);
}
}
}
/**
* Returns the user id of the current process
* @return user id of the current process
* @hide
*/
@SystemApi
public static final int myUserId() {
return getUserId(Process.myUid());
}
/**
* Returns true if this UserHandle refers to the owner user; false otherwise.
* @return true if this UserHandle refers to the owner user; false otherwise.
* @hide
*/
@SystemApi
public final boolean isOwner() {
return this.equals(OWNER);
}
/** @hide */
public UserHandle(int h) {
mHandle = h;
}
/**
* Returns the userId stored in this UserHandle.
* @hide
*/
@SystemApi
public int getIdentifier() {
return mHandle;
}
@Override
public String toString() {
return "UserHandle{" + mHandle + "}";
}
@Override
public boolean equals(Object obj) {
try {
if (obj != null) {
UserHandle other = (UserHandle)obj;
return mHandle == other.mHandle;
}
} catch (ClassCastException e) {
}
return false;
}
@Override
public int hashCode() {
return mHandle;
}
public int describeContents() {
return 0;
}
public void writeToParcel(Parcel out, int flags) {
out.writeInt(mHandle);
}
/**
* Write a UserHandle to a Parcel, handling null pointers. Must be
* read with {@link #readFromParcel(Parcel)}.
*
* @param h The UserHandle to be written.
* @param out The Parcel in which the UserHandle will be placed.
*
* @see #readFromParcel(Parcel)
*/
public static void writeToParcel(UserHandle h, Parcel out) {
if (h != null) {
h.writeToParcel(out, 0);
} else {
out.writeInt(USER_NULL);
}
}
/**
* Read a UserHandle from a Parcel that was previously written
* with {@link #writeToParcel(UserHandle, Parcel)}, returning either
* a null or new object as appropriate.
*
* @param in The Parcel from which to read the UserHandle
* @return Returns a new UserHandle matching the previously written
* object, or null if a null had been written.
*
* @see #writeToParcel(UserHandle, Parcel)
*/
public static UserHandle readFromParcel(Parcel in) {
int h = in.readInt();
return h != USER_NULL ? new UserHandle(h) : null;
}
public static final Parcelable.Creator<UserHandle> CREATOR
= new Parcelable.Creator<UserHandle>() {
public UserHandle createFromParcel(Parcel in) {
return new UserHandle(in);
}
public UserHandle[] newArray(int size) {
return new UserHandle[size];
}
};
/**
* Instantiate a new UserHandle from the data in a Parcel that was
* previously written with {@link #writeToParcel(Parcel, int)}. Note that you
* must not use this with data written by
* {@link #writeToParcel(UserHandle, Parcel)} since it is not possible
* to handle a null UserHandle here.
*
* @param in The Parcel containing the previously written UserHandle,
* positioned at the location in the buffer where it was written.
*/
public UserHandle(Parcel in) {
mHandle = in.readInt();
}
}
