| /* |
| * Copyright (C) 2019 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.location; |
| |
| import static android.Manifest.permission.ACCESS_COARSE_LOCATION; |
| import static android.Manifest.permission.ACCESS_FINE_LOCATION; |
| import static android.content.pm.PackageManager.PERMISSION_GRANTED; |
| |
| import android.annotation.IntDef; |
| import android.annotation.Nullable; |
| import android.app.AppOpsManager; |
| import android.content.Context; |
| import android.os.Binder; |
| import android.os.UserHandle; |
| |
| import com.android.internal.annotations.VisibleForTesting; |
| import com.android.internal.util.ArrayUtils; |
| import com.android.internal.util.Preconditions; |
| |
| import java.lang.annotation.Retention; |
| import java.lang.annotation.RetentionPolicy; |
| import java.util.Objects; |
| |
| /** |
| * Represents the calling process's uid, pid, and package name. |
| */ |
| public final class CallerIdentity { |
| |
| public static final int PERMISSION_NONE = 0; |
| public static final int PERMISSION_COARSE = 1; |
| public static final int PERMISSION_FINE = 2; |
| |
| @IntDef({PERMISSION_NONE, PERMISSION_COARSE, PERMISSION_FINE}) |
| @Retention(RetentionPolicy.SOURCE) |
| public @interface PermissionLevel {} |
| |
| /** |
| * Converts the given permission level to the corresponding permission. |
| */ |
| public static String asPermission(@PermissionLevel int permissionLevel) { |
| switch (permissionLevel) { |
| case PERMISSION_COARSE: |
| return ACCESS_COARSE_LOCATION; |
| case PERMISSION_FINE: |
| return ACCESS_FINE_LOCATION; |
| default: |
| throw new IllegalArgumentException(); |
| } |
| } |
| |
| /** |
| * Converts the given permission level to the corresponding appop. |
| */ |
| public static int asAppOp(@PermissionLevel int permissionLevel) { |
| switch (permissionLevel) { |
| case PERMISSION_COARSE: |
| return AppOpsManager.OP_COARSE_LOCATION; |
| case PERMISSION_FINE: |
| return AppOpsManager.OP_FINE_LOCATION; |
| default: |
| throw new IllegalArgumentException(); |
| } |
| } |
| |
| /** |
| * Creates a CallerIdentity from the current binder identity, using the given package and |
| * feature id. The package will be checked to enforce it belongs to the calling uid, and a |
| * security exception will be thrown if it is invalid. |
| */ |
| public static CallerIdentity fromBinder(Context context, String packageName, |
| @Nullable String featureId) { |
| int uid = Binder.getCallingUid(); |
| if (!ArrayUtils.contains(context.getPackageManager().getPackagesForUid(uid), packageName)) { |
| throw new SecurityException("invalid package \"" + packageName + "\" for uid " + uid); |
| } |
| |
| return fromBinderUnsafe(context, packageName, featureId); |
| } |
| |
| /** |
| * Creates a CallerIdentity from the current binder identity, using the given package and |
| * feature id. The package will not be checked to enforce that it belongs to the calling uid - |
| * this method should only be used if the package will be validated by some other means, such as |
| * an appops call. |
| */ |
| public static CallerIdentity fromBinderUnsafe(Context context, String packageName, |
| @Nullable String featureId) { |
| return new CallerIdentity(Binder.getCallingUid(), Binder.getCallingPid(), |
| UserHandle.getCallingUserId(), packageName, featureId, |
| getBinderPermissionLevel(context)); |
| } |
| |
| /** |
| * Throws a security exception if the caller does not hold a location permission. |
| */ |
| public static void enforceCallingOrSelfLocationPermission(Context context) { |
| enforceLocationPermission(Binder.getCallingUid(), getBinderPermissionLevel(context)); |
| } |
| |
| /** |
| * Returns false if the caller does not hold a location permission, true otherwise. |
| */ |
| public static boolean checkCallingOrSelfLocationPermission(Context context) { |
| return checkLocationPermission(getBinderPermissionLevel(context)); |
| } |
| |
| private static void enforceLocationPermission(int uid, @PermissionLevel int permissionLevel) { |
| if (checkLocationPermission(permissionLevel)) { |
| return; |
| } |
| |
| throw new SecurityException("uid " + uid + " does not have " + ACCESS_COARSE_LOCATION |
| + " or " + ACCESS_FINE_LOCATION + "."); |
| } |
| |
| private static boolean checkLocationPermission(@PermissionLevel int permissionLevel) { |
| return permissionLevel >= PERMISSION_COARSE; |
| } |
| |
| private static @PermissionLevel int getBinderPermissionLevel(Context context) { |
| if (context.checkCallingOrSelfPermission(ACCESS_FINE_LOCATION) == PERMISSION_GRANTED) { |
| return PERMISSION_FINE; |
| } |
| if (context.checkCallingOrSelfPermission(ACCESS_COARSE_LOCATION) == PERMISSION_GRANTED) { |
| return PERMISSION_COARSE; |
| } |
| |
| return PERMISSION_NONE; |
| } |
| |
| /** The calling UID. */ |
| public final int uid; |
| |
| /** The calling PID. */ |
| public final int pid; |
| |
| /** The calling user. */ |
| public final int userId; |
| |
| /** The calling package name. */ |
| public final String packageName; |
| |
| /** The calling feature id. */ |
| public final @Nullable String featureId; |
| |
| /** |
| * The calling location permission level. This field should only be used for validating |
| * permissions for API access. It should not be used for validating permissions for location |
| * access - that must be done through appops. |
| */ |
| public final @PermissionLevel int permissionLevel; |
| |
| @VisibleForTesting |
| public CallerIdentity(int uid, int pid, int userId, String packageName, |
| @Nullable String featureId, @PermissionLevel int permissionLevel) { |
| this.uid = uid; |
| this.pid = pid; |
| this.userId = userId; |
| this.packageName = Objects.requireNonNull(packageName); |
| this.featureId = featureId; |
| this.permissionLevel = Preconditions.checkArgumentInRange(permissionLevel, PERMISSION_NONE, |
| PERMISSION_FINE, "permissionLevel"); |
| } |
| |
| /** |
| * Throws a security exception if the CallerIdentity does not hold a location permission. |
| */ |
| public void enforceLocationPermission() { |
| enforceLocationPermission(uid, permissionLevel); |
| } |
| |
| @Override |
| public String toString() { |
| int length = 10 + packageName.length(); |
| if (featureId != null) { |
| length += featureId.length(); |
| } |
| |
| StringBuilder builder = new StringBuilder(length); |
| builder.append(pid).append("/").append(packageName); |
| if (featureId != null) { |
| builder.append("["); |
| if (featureId.startsWith(packageName)) { |
| builder.append(featureId.substring(packageName.length())); |
| } else { |
| builder.append(featureId); |
| } |
| builder.append("]"); |
| } |
| return builder.toString(); |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (this == o) { |
| return true; |
| } |
| if (!(o instanceof CallerIdentity)) { |
| return false; |
| } |
| CallerIdentity that = (CallerIdentity) o; |
| return uid == that.uid |
| && pid == that.pid |
| && packageName.equals(that.packageName) |
| && Objects.equals(featureId, that.featureId); |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(uid, pid, packageName, featureId); |
| } |
| } |