code: /*
   * 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 com.lody.virtual.os;
  
  import android.os.Parcel;
  import android.os.Parcelable;
  import android.os.Process;
  import android.util.SparseArray;
  
  import com.lody.virtual.client.VClientImpl;
  
  import java.io.PrintWriter;
  
  /**
   * Representation of a user on the device.
   */
  public final class VUserHandle 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 VUserHandle ALL = new VUserHandle(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 VUserHandle CURRENT = new VUserHandle(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 VUserHandle CURRENT_OR_SELF = new VUserHandle(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 VUserHandle OWNER = new VUserHandle(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;
      /**
       * First gid for applications to share resources. Used when forward-locking
       * is enabled but all UserHandles need to be able to read the resources.
       * @hide
       */
      public static final int FIRST_SHARED_APPLICATION_GID = 50000;
      /**
       * Last gid for applications to share resources. Used when forward-locking
       * is enabled but all UserHandles need to be able to read the resources.
       * @hide
       */
      public static final int LAST_SHARED_APPLICATION_GID = 59999;
      /**
       * First vuid used for fully isolated sandboxed processes (with no permissions of their own)
       * @hide
       */
      public static final int FIRST_ISOLATED_UID = 99000;
      /**
       * Last vuid used for fully isolated sandboxed processes (with no permissions of their own)
       * @hide
       */
      public static final int LAST_ISOLATED_UID = 99999;
      public static final Parcelable.Creator<VUserHandle> CREATOR
              = new Parcelable.Creator<VUserHandle>() {
          public VUserHandle createFromParcel(Parcel in) {
              return new VUserHandle(in);
          }
  
          public VUserHandle[] newArray(int size) {
              return new VUserHandle[size];
          }
      };
      private static final SparseArray<VUserHandle> userHandles = new SparseArray<VUserHandle>();
      final int mHandle;
  
      /** @hide */
      public VUserHandle(int h) {
          mHandle = h;
      }
  
  
      /**
       * Instantiate a new VUserHandle 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(VUserHandle, Parcel)} since it is not possible
       * to handle a null VUserHandle here.
       *
       * @param in The Parcel containing the previously written VUserHandle,
       * positioned at the location in the buffer where it was written.
       */
      public VUserHandle(Parcel in) {
          mHandle = in.readInt();
      }
  
      /**
       * 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 boolean isSameUser(int uid1, int uid2) {
          return getUserId(uid1) == getUserId(uid2);
      }
  
      public static boolean accept(int userId) {
          if (userId == USER_ALL || userId == myUserId()) {
              return true;
          }
          return false;
      }
  
      /**
       * Checks to see if both uids are referring to the same app id, ignoring the user id part of the
       * uids.
       * @param uid1 vuid to compare
       * @param uid2 other vuid 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 >= FIRST_ISOLATED_UID && appId <= 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 vuid.
       * @hide
       */
      public static int getUserId(int uid) {
          if (MU_ENABLED) {
              return uid / PER_USER_RANGE;
          } else {
              return 0;
          }
      }
  
      /** @hide */
      public static int getCallingUserId() {
          return getUserId(VBinder.getCallingUid());
      }
  
      /**
       * Generate a text representation of the vuid, breaking out its individual
       * components -- user, app, isolated, etc.
       * @hide
       */
  
      /** @hide */
      public static VUserHandle getCallingUserHandle() {
          int userId = getUserId(VBinder.getCallingUid());
          VUserHandle userHandle = userHandles.get(userId);
          // Intentionally not synchronized to save time
          if (userHandle == null) {
              userHandle = new VUserHandle(userId);
              userHandles.put(userId, userHandle);
          }
          return userHandle;
      }
  
      /**
       * Returns the vuid that is composed from the userId and the appId.
       * @hide
       */
      public static 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 vuid) for a given vuid, stripping out the user id from it.
       * @hide
       */
      public static int getAppId(int uid) {
          return uid % PER_USER_RANGE;
      }
  
      public static int myAppId() {
          return getAppId(VClientImpl.get().getVUid());
      }
  
      /**
       * Returns the app id for a given shared app gid.
       * @hide
       */
      public static int getAppIdFromSharedAppGid(int gid) {
          final int noUserGid = getAppId(gid);
          if (noUserGid < FIRST_SHARED_APPLICATION_GID ||
                  noUserGid > LAST_SHARED_APPLICATION_GID) {
              throw new IllegalArgumentException(Integer.toString(gid) + " is not a shared app gid");
          }
          return (noUserGid + Process.FIRST_APPLICATION_UID) - FIRST_SHARED_APPLICATION_GID;
      }
  
      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 >= FIRST_ISOLATED_UID && appId <= LAST_ISOLATED_UID) {
                  sb.append('i');
                  sb.append(appId - 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 vuid, breaking out its individual
       * components -- user, app, isolated, etc.
       * @hide
       */
      public static String formatUid(int uid) {
          StringBuilder sb = new StringBuilder();
          formatUid(sb, uid);
          return sb.toString();
      }
  
      /**
       * Generate a text representation of the vuid, 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 >= FIRST_ISOLATED_UID && appId <= LAST_ISOLATED_UID) {
                  pw.print('i');
                  pw.print(appId - 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
       */
      public static int myUserId() {
          return getUserId(VClientImpl.get().getVUid());
      }
  
      /**
       * Write a VUserHandle to a Parcel, handling null pointers.  Must be
       * read with {@link #readFromParcel(Parcel)}.
       *
       * @param h The VUserHandle to be written.
       * @param out The Parcel in which the VUserHandle will be placed.
       *
       * @see #readFromParcel(Parcel)
       */
      public static void writeToParcel(VUserHandle h, Parcel out) {
          if (h != null) {
              h.writeToParcel(out, 0);
          } else {
              out.writeInt(USER_NULL);
          }
      }
  
      /**
       * Read a VUserHandle from a Parcel that was previously written
       * with {@link #writeToParcel(VUserHandle, Parcel)}, returning either
       * a null or new object as appropriate.
       *
       * @param in The Parcel from which to read the VUserHandle
       * @return Returns a new VUserHandle matching the previously written
       * object, or null if a null had been written.
       *
       * @see #writeToParcel(VUserHandle, Parcel)
       */
      public static VUserHandle readFromParcel(Parcel in) {
          int h = in.readInt();
          return h != USER_NULL ? new VUserHandle(h) : null;
      }
  
      public static VUserHandle myUserHandle() {
          return new VUserHandle(myUserId());
      }
      
      /**
       * Returns true if this VUserHandle refers to the owner user; false otherwise.
       * @return true if this VUserHandle refers to the owner user; false otherwise.
       * @hide
       */
      public final boolean isOwner() {
          return this.equals(OWNER);
      }
  
      /**
       * Returns the userId stored in this VUserHandle.
       * @hide
       */
      public int getIdentifier() {
          return mHandle;
      }
  
      @Override
      public String toString() {
          return "VUserHandle{" + mHandle + "}";
      }
      
      @Override
      public boolean equals(Object obj) {
          try {
              if (obj != null) {
                  VUserHandle other = (VUserHandle)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);
      }
  }
  