/*
* Copyright (C) 2015 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.android.server.pm;
import android.content.pm.PackageManager;
import android.os.UserHandle;
import android.util.ArrayMap;
import android.util.ArraySet;
import android.util.SparseArray;
import android.util.SparseBooleanArray;
import com.android.internal.util.ArrayUtils;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Set;
/**
* This class encapsulates the permissions for a package or a shared user.
* <p>
* There are two types of permissions: install (granted at installation)
* and runtime (granted at runtime). Install permissions are granted to
* all device users while runtime permissions are granted explicitly to
* specific users.
* </p>
* <p>
* The permissions are kept on a per device user basis. For example, an
* application may have some runtime permissions granted under the device
* owner but not granted under the secondary user.
* <p>
* This class is also responsible for keeping track of the Linux gids per
* user for a package or a shared user. The gids are computed as a set of
* the gids for all granted permissions' gids on a per user basis.
* </p>
*/
public final class PermissionsState {
/** The permission operation failed. */
public static final int PERMISSION_OPERATION_FAILURE = -1;
/** The permission operation succeeded and no gids changed. */
public static final int PERMISSION_OPERATION_SUCCESS = 0;
/** The permission operation succeeded and gids changed. */
public static final int PERMISSION_OPERATION_SUCCESS_GIDS_CHANGED = 1;
private static final int[] NO_GIDS = {};
private ArrayMap<String, PermissionData> mPermissions;
private int[] mGlobalGids = NO_GIDS;
private SparseBooleanArray mPermissionReviewRequired;
public PermissionsState() {
/* do nothing */
}
public PermissionsState(PermissionsState prototype) {
copyFrom(prototype);
}
/**
* Sets the global gids, applicable to all users.
*
* @param globalGids The global gids.
*/
public void setGlobalGids(int[] globalGids) {
if (!ArrayUtils.isEmpty(globalGids)) {
mGlobalGids = Arrays.copyOf(globalGids, globalGids.length);
}
}
/**
* Initialized this instance from another one.
*
* @param other The other instance.
*/
public void copyFrom(PermissionsState other) {
if (other == this) {
return;
}
if (mPermissions != null) {
if (other.mPermissions == null) {
mPermissions = null;
} else {
mPermissions.clear();
}
}
if (other.mPermissions != null) {
if (mPermissions == null) {
mPermissions = new ArrayMap<>();
}
final int permissionCount = other.mPermissions.size();
for (int i = 0; i < permissionCount; i++) {
String name = other.mPermissions.keyAt(i);
PermissionData permissionData = other.mPermissions.valueAt(i);
mPermissions.put(name, new PermissionData(permissionData));
}
}
mGlobalGids = NO_GIDS;
if (other.mGlobalGids != NO_GIDS) {
mGlobalGids = Arrays.copyOf(other.mGlobalGids,
other.mGlobalGids.length);
}
if (mPermissionReviewRequired != null) {
if (other.mPermissionReviewRequired == null) {
mPermissionReviewRequired = null;
} else {
mPermissionReviewRequired.clear();
}
}
if (other.mPermissionReviewRequired != null) {
if (mPermissionReviewRequired == null) {
mPermissionReviewRequired = new SparseBooleanArray();
}
final int userCount = other.mPermissionReviewRequired.size();
for (int i = 0; i < userCount; i++) {
final boolean reviewRequired = other.mPermissionReviewRequired.valueAt(i);
mPermissionReviewRequired.put(i, reviewRequired);
}
}
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final PermissionsState other = (PermissionsState) obj;
if (mPermissions == null) {
if (other.mPermissions != null) {
return false;
}
} else if (!mPermissions.equals(other.mPermissions)) {
return false;
}
if (mPermissionReviewRequired == null) {
if (other.mPermissionReviewRequired != null) {
return false;
}
} else if (!mPermissionReviewRequired.equals(other.mPermissionReviewRequired)) {
return false;
}
return Arrays.equals(mGlobalGids, other.mGlobalGids);
}
public boolean isPermissionReviewRequired(int userId) {
return mPermissionReviewRequired != null && mPermissionReviewRequired.get(userId);
}
/**
* Grant an install permission.
*
* @param permission The permission to grant.
* @return The operation result which is either {@link #PERMISSION_OPERATION_SUCCESS},
* or {@link #PERMISSION_OPERATION_SUCCESS_GIDS_CHANGED}, or {@link
* #PERMISSION_OPERATION_FAILURE}.
*/
public int grantInstallPermission(BasePermission permission) {
return grantPermission(permission, UserHandle.USER_ALL);
}
/**
* Revoke an install permission.
*
* @param permission The permission to revoke.
* @return The operation result which is either {@link #PERMISSION_OPERATION_SUCCESS},
* or {@link #PERMISSION_OPERATION_SUCCESS_GIDS_CHANGED}, or {@link
* #PERMISSION_OPERATION_FAILURE}.
*/
public int revokeInstallPermission(BasePermission permission) {
return revokePermission(permission, UserHandle.USER_ALL);
}
/**
* Grant a runtime permission for a given device user.
*
* @param permission The permission to grant.
* @param userId The device user id.
* @return The operation result which is either {@link #PERMISSION_OPERATION_SUCCESS},
* or {@link #PERMISSION_OPERATION_SUCCESS_GIDS_CHANGED}, or {@link
* #PERMISSION_OPERATION_FAILURE}.
*/
public int grantRuntimePermission(BasePermission permission, int userId) {
enforceValidUserId(userId);
if (userId == UserHandle.USER_ALL) {
return PERMISSION_OPERATION_FAILURE;
}
return grantPermission(permission, userId);
}
/**
* Revoke a runtime permission for a given device user.
*
* @param permission The permission to revoke.
* @param userId The device user id.
* @return The operation result which is either {@link #PERMISSION_OPERATION_SUCCESS},
* or {@link #PERMISSION_OPERATION_SUCCESS_GIDS_CHANGED}, or {@link
* #PERMISSION_OPERATION_FAILURE}.
*/
public int revokeRuntimePermission(BasePermission permission, int userId) {
enforceValidUserId(userId);
if (userId == UserHandle.USER_ALL) {
return PERMISSION_OPERATION_FAILURE;
}
return revokePermission(permission, userId);
}
/**
* Gets whether this state has a given runtime permission for a
* given device user id.
*
* @param name The permission name.
* @param userId The device user id.
* @return Whether this state has the permission.
*/
public boolean hasRuntimePermission(String name, int userId) {
enforceValidUserId(userId);
return !hasInstallPermission(name) && hasPermission(name, userId);
}
/**
* Gets whether this state has a given install permission.
*
* @param name The permission name.
* @return Whether this state has the permission.
*/
public boolean hasInstallPermission(String name) {
return hasPermission(name, UserHandle.USER_ALL);
}
/**
* Gets whether the state has a given permission for the specified
* user, regardless if this is an install or a runtime permission.
*
* @param name The permission name.
* @param userId The device user id.
* @return Whether the user has the permission.
*/
public boolean hasPermission(String name, int userId) {
enforceValidUserId(userId);
if (mPermissions == null) {
return false;
}
PermissionData permissionData = mPermissions.get(name);
return permissionData != null && permissionData.isGranted(userId);
}
/**
* Returns whether the state has any known request for the given permission name,
* whether or not it has been granted.
*/
public boolean hasRequestedPermission(ArraySet<String> names) {
if (mPermissions == null) {
return false;
}
for (int i=names.size()-1; i>=0; i--) {
if (mPermissions.get(names.valueAt(i)) != null) {
return true;
}
}
return false;
}
/**
* Gets all permissions for a given device user id regardless if they
* are install time or runtime permissions.
*
* @param userId The device user id.
* @return The permissions or an empty set.
*/
public Set<String> getPermissions(int userId) {
enforceValidUserId(userId);
if (mPermissions == null) {
return Collections.emptySet();
}
Set<String> permissions = new ArraySet<>(mPermissions.size());
final int permissionCount = mPermissions.size();
for (int i = 0; i < permissionCount; i++) {
String permission = mPermissions.keyAt(i);
if (hasInstallPermission(permission)) {
permissions.add(permission);
continue;
}
if (userId != UserHandle.USER_ALL) {
if (hasRuntimePermission(permission, userId)) {
permissions.add(permission);
}
}
}
return permissions;
}
/**
* Gets the state for an install permission or null if no such.
*
* @param name The permission name.
* @return The permission state.
*/
public PermissionState getInstallPermissionState(String name) {
return getPermissionState(name, UserHandle.USER_ALL);
}
/**
* Gets the state for a runtime permission or null if no such.
*
* @param name The permission name.
* @param userId The device user id.
* @return The permission state.
*/
public PermissionState getRuntimePermissionState(String name, int userId) {
enforceValidUserId(userId);
return getPermissionState(name, userId);
}
/**
* Gets all install permission states.
*
* @return The permission states or an empty set.
*/
public List<PermissionState> getInstallPermissionStates() {
return getPermissionStatesInternal(UserHandle.USER_ALL);
}
/**
* Gets all runtime permission states.
*
* @return The permission states or an empty set.
*/
public List<PermissionState> getRuntimePermissionStates(int userId) {
enforceValidUserId(userId);
return getPermissionStatesInternal(userId);
}
/**
* Gets the flags for a permission regardless if it is install or
* runtime permission.
*
* @param name The permission name.
* @return The permission state or null if no such.
*/
public int getPermissionFlags(String name, int userId) {
PermissionState installPermState = getInstallPermissionState(name);
if (installPermState != null) {
return installPermState.getFlags();
}
PermissionState runtimePermState = getRuntimePermissionState(name, userId);
if (runtimePermState != null) {
return runtimePermState.getFlags();
}
return 0;
}
/**
* Update the flags associated with a given permission.
* @param permission The permission whose flags to update.
* @param userId The user for which to update.
* @param flagMask Mask for which flags to change.
* @param flagValues New values for the mask flags.
* @return Whether the permission flags changed.
*/
public boolean updatePermissionFlags(BasePermission permission, int userId,
int flagMask, int flagValues) {
enforceValidUserId(userId);
final boolean mayChangeFlags = flagValues != 0 || flagMask != 0;
if (mPermissions == null) {
if (!mayChangeFlags) {
return false;
}
ensurePermissionData(permission);
}
PermissionData permissionData = mPermissions.get(permission.name);
if (permissionData == null) {
if (!mayChangeFlags) {
return false;
}
permissionData = ensurePermissionData(permission);
}
final int oldFlags = permissionData.getFlags(userId);
final boolean updated = permissionData.updateFlags(userId, flagMask, flagValues);
if (updated) {
final int newFlags = permissionData.getFlags(userId);
if ((oldFlags & PackageManager.FLAG_PERMISSION_REVIEW_REQUIRED) == 0
&& (newFlags & PackageManager.FLAG_PERMISSION_REVIEW_REQUIRED) != 0) {
if (mPermissionReviewRequired == null) {
mPermissionReviewRequired = new SparseBooleanArray();
}
mPermissionReviewRequired.put(userId, true);
} else if ((oldFlags & PackageManager.FLAG_PERMISSION_REVIEW_REQUIRED) != 0
&& (newFlags & PackageManager.FLAG_PERMISSION_REVIEW_REQUIRED) == 0) {
if (mPermissionReviewRequired != null) {
mPermissionReviewRequired.delete(userId);
if (mPermissionReviewRequired.size() <= 0) {
mPermissionReviewRequired = null;
}
}
}
}
return updated;
}
public boolean updatePermissionFlagsForAllPermissions(
int userId, int flagMask, int flagValues) {
enforceValidUserId(userId);
if (mPermissions == null) {
return false;
}
boolean changed = false;
final int permissionCount = mPermissions.size();
for (int i = 0; i < permissionCount; i++) {
PermissionData permissionData = mPermissions.valueAt(i);
changed |= permissionData.updateFlags(userId, flagMask, flagValues);
}
return changed;
}
/**
* Compute the Linux gids for a given device user from the permissions
* granted to this user. Note that these are computed to avoid additional
* state as they are rarely accessed.
*
* @param userId The device user id.
* @return The gids for the device user.
*/
public int[] computeGids(int userId) {
enforceValidUserId(userId);
int[] gids = mGlobalGids;
if (mPermissions != null) {
final int permissionCount = mPermissions.size();
for (int i = 0; i < permissionCount; i++) {
String permission = mPermissions.keyAt(i);
if (!hasPermission(permission, userId)) {
continue;
}
PermissionData permissionData = mPermissions.valueAt(i);
final int[] permGids = permissionData.computeGids(userId);
if (permGids != NO_GIDS) {
gids = appendInts(gids, permGids);
}
}
}
return gids;
}
/**
* Compute the Linux gids for all device users from the permissions
* granted to these users.
*
* @return The gids for all device users.
*/
public int[] computeGids(int[] userIds) {
int[] gids = mGlobalGids;
for (int userId : userIds) {
final int[] userGids = computeGids(userId);
gids = appendInts(gids, userGids);
}
return gids;
}
/**
* Resets the internal state of this object.
*/
public void reset() {
mGlobalGids = NO_GIDS;
mPermissions = null;
mPermissionReviewRequired = null;
}
private PermissionState getPermissionState(String name, int userId) {
if (mPermissions == null) {
return null;
}
PermissionData permissionData = mPermissions.get(name);
if (permissionData == null) {
return null;
}
return permissionData.getPermissionState(userId);
}
private List<PermissionState> getPermissionStatesInternal(int userId) {
enforceValidUserId(userId);
if (mPermissions == null) {
return Collections.emptyList();
}
List<PermissionState> permissionStates = new ArrayList<>();
final int permissionCount = mPermissions.size();
for (int i = 0; i < permissionCount; i++) {
PermissionData permissionData = mPermissions.valueAt(i);
PermissionState permissionState = permissionData.getPermissionState(userId);
if (permissionState != null) {
permissionStates.add(permissionState);
}
}
return permissionStates;
}
private int grantPermission(BasePermission permission, int userId) {
if (hasPermission(permission.name, userId)) {
return PERMISSION_OPERATION_FAILURE;
}
final boolean hasGids = !ArrayUtils.isEmpty(permission.computeGids(userId));
final int[] oldGids = hasGids ? computeGids(userId) : NO_GIDS;
PermissionData permissionData = ensurePermissionData(permission);
if (!permissionData.grant(userId)) {
return PERMISSION_OPERATION_FAILURE;
}
if (hasGids) {
final int[] newGids = computeGids(userId);
if (oldGids.length != newGids.length) {
return PERMISSION_OPERATION_SUCCESS_GIDS_CHANGED;
}
}
return PERMISSION_OPERATION_SUCCESS;
}
private int revokePermission(BasePermission permission, int userId) {
if (!hasPermission(permission.name, userId)) {
return PERMISSION_OPERATION_FAILURE;
}
final boolean hasGids = !ArrayUtils.isEmpty(permission.computeGids(userId));
final int[] oldGids = hasGids ? computeGids(userId) : NO_GIDS;
PermissionData permissionData = mPermissions.get(permission.name);
if (!permissionData.revoke(userId)) {
return PERMISSION_OPERATION_FAILURE;
}
if (permissionData.isDefault()) {
ensureNoPermissionData(permission.name);
}
if (hasGids) {
final int[] newGids = computeGids(userId);
if (oldGids.length != newGids.length) {
return PERMISSION_OPERATION_SUCCESS_GIDS_CHANGED;
}
}
return PERMISSION_OPERATION_SUCCESS;
}
// TODO: fix this to use arraycopy and append all ints in one go
private static int[] appendInts(int[] current, int[] added) {
if (current != null && added != null) {
for (int guid : added) {
current = ArrayUtils.appendInt(current, guid);
}
}
return current;
}
private static void enforceValidUserId(int userId) {
if (userId != UserHandle.USER_ALL && userId < 0) {
throw new IllegalArgumentException("Invalid userId:" + userId);
}
}
private PermissionData ensurePermissionData(BasePermission permission) {
if (mPermissions == null) {
mPermissions = new ArrayMap<>();
}
PermissionData permissionData = mPermissions.get(permission.name);
if (permissionData == null) {
permissionData = new PermissionData(permission);
mPermissions.put(permission.name, permissionData);
}
return permissionData;
}
private void ensureNoPermissionData(String name) {
if (mPermissions == null) {
return;
}
mPermissions.remove(name);
if (mPermissions.isEmpty()) {
mPermissions = null;
}
}
private static final class PermissionData {
private final BasePermission mPerm;
private SparseArray<PermissionState> mUserStates = new SparseArray<>();
public PermissionData(BasePermission perm) {
mPerm = perm;
}
public PermissionData(PermissionData other) {
this(other.mPerm);
final int otherStateCount = other.mUserStates.size();
for (int i = 0; i < otherStateCount; i++) {
final int otherUserId = other.mUserStates.keyAt(i);
PermissionState otherState = other.mUserStates.valueAt(i);
mUserStates.put(otherUserId, new PermissionState(otherState));
}
}
public int[] computeGids(int userId) {
return mPerm.computeGids(userId);
}
public boolean isGranted(int userId) {
if (isInstallPermission()) {
userId = UserHandle.USER_ALL;
}
PermissionState userState = mUserStates.get(userId);
if (userState == null) {
return false;
}
return userState.mGranted;
}
public boolean grant(int userId) {
if (!isCompatibleUserId(userId)) {
return false;
}
if (isGranted(userId)) {
return false;
}
PermissionState userState = mUserStates.get(userId);
if (userState == null) {
userState = new PermissionState(mPerm.name);
mUserStates.put(userId, userState);
}
userState.mGranted = true;
return true;
}
public boolean revoke(int userId) {
if (!isCompatibleUserId(userId)) {
return false;
}
if (!isGranted(userId)) {
return false;
}
PermissionState userState = mUserStates.get(userId);
userState.mGranted = false;
if (userState.isDefault()) {
mUserStates.remove(userId);
}
return true;
}
public PermissionState getPermissionState(int userId) {
return mUserStates.get(userId);
}
public int getFlags(int userId) {
PermissionState userState = mUserStates.get(userId);
if (userState != null) {
return userState.mFlags;
}
return 0;
}
public boolean isDefault() {
return mUserStates.size() <= 0;
}
public static boolean isInstallPermissionKey(int userId) {
return userId == UserHandle.USER_ALL;
}
public boolean updateFlags(int userId, int flagMask, int flagValues) {
if (isInstallPermission()) {
userId = UserHandle.USER_ALL;
}
if (!isCompatibleUserId(userId)) {
return false;
}
final int newFlags = flagValues & flagMask;
PermissionState userState = mUserStates.get(userId);
if (userState != null) {
final int oldFlags = userState.mFlags;
userState.mFlags = (userState.mFlags & ~flagMask) | newFlags;
if (userState.isDefault()) {
mUserStates.remove(userId);
}
return userState.mFlags != oldFlags;
} else if (newFlags != 0) {
userState = new PermissionState(mPerm.name);
userState.mFlags = newFlags;
mUserStates.put(userId, userState);
return true;
}
return false;
}
private boolean isCompatibleUserId(int userId) {
return isDefault() || !(isInstallPermission() ^ isInstallPermissionKey(userId));
}
private boolean isInstallPermission() {
return mUserStates.size() == 1
&& mUserStates.get(UserHandle.USER_ALL) != null;
}
}
public static final class PermissionState {
private final String mName;
private boolean mGranted;
private int mFlags;
public PermissionState(String name) {
mName = name;
}
public PermissionState(PermissionState other) {
mName = other.mName;
mGranted = other.mGranted;
mFlags = other.mFlags;
}
public boolean isDefault() {
return !mGranted && mFlags == 0;
}
public String getName() {
return mName;
}
public boolean isGranted() {
return mGranted;
}
public int getFlags() {
return mFlags;
}
}
}