/*
* Copyright (C) 2014 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.hdmi;
import android.hardware.hdmi.HdmiDeviceInfo;
import android.util.SparseArray;
/**
* A helper class to validates {@link HdmiCecMessage}.
*/
public final class HdmiCecMessageValidator {
private static final String TAG = "HdmiCecMessageValidator";
static final int OK = 0;
static final int ERROR_SOURCE = 1;
static final int ERROR_DESTINATION = 2;
static final int ERROR_PARAMETER = 3;
static final int ERROR_PARAMETER_SHORT = 4;
private final HdmiControlService mService;
interface ParameterValidator {
/**
* @return errorCode errorCode can be {@link #OK}, {@link #ERROR_PARAMETER} or
* {@link #ERROR_PARAMETER_SHORT}.
*/
int isValid(byte[] params);
}
// Only the direct addressing is allowed.
private static final int DEST_DIRECT = 1 << 0;
// Only the broadcast addressing is allowed.
private static final int DEST_BROADCAST = 1 << 1;
// Both the direct and the broadcast addressing are allowed.
private static final int DEST_ALL = DEST_DIRECT | DEST_BROADCAST;
// True if the messages from address 15 (unregistered) are allowed.
private static final int SRC_UNREGISTERED = 1 << 2;
private static class ValidationInfo {
public final ParameterValidator parameterValidator;
public final int addressType;
public ValidationInfo(ParameterValidator validator, int type) {
parameterValidator = validator;
addressType = type;
}
}
final SparseArray<ValidationInfo> mValidationInfo = new SparseArray<>();
public HdmiCecMessageValidator(HdmiControlService service) {
mService = service;
// Messages related to the physical address.
PhysicalAddressValidator physicalAddressValidator = new PhysicalAddressValidator();
addValidationInfo(Constants.MESSAGE_ACTIVE_SOURCE,
physicalAddressValidator, DEST_BROADCAST | SRC_UNREGISTERED);
addValidationInfo(Constants.MESSAGE_INACTIVE_SOURCE, physicalAddressValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_REPORT_PHYSICAL_ADDRESS,
new ReportPhysicalAddressValidator(), DEST_BROADCAST | SRC_UNREGISTERED);
addValidationInfo(Constants.MESSAGE_ROUTING_CHANGE,
new RoutingChangeValidator(), DEST_BROADCAST | SRC_UNREGISTERED);
addValidationInfo(Constants.MESSAGE_ROUTING_INFORMATION,
physicalAddressValidator, DEST_BROADCAST | SRC_UNREGISTERED);
addValidationInfo(Constants.MESSAGE_SET_STREAM_PATH,
physicalAddressValidator, DEST_BROADCAST);
addValidationInfo(Constants.MESSAGE_SYSTEM_AUDIO_MODE_REQUEST,
new SystemAudioModeRequestValidator(), DEST_DIRECT);
// Messages have no parameter.
FixedLengthValidator noneValidator = new FixedLengthValidator(0);
addValidationInfo(Constants.MESSAGE_ABORT, noneValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_GET_CEC_VERSION, noneValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_GET_MENU_LANGUAGE,
noneValidator, DEST_DIRECT | SRC_UNREGISTERED);
addValidationInfo(Constants.MESSAGE_GIVE_AUDIO_STATUS, noneValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_GIVE_DEVICE_POWER_STATUS, noneValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_GIVE_DEVICE_VENDOR_ID,
noneValidator, DEST_DIRECT | SRC_UNREGISTERED);
addValidationInfo(Constants.MESSAGE_GIVE_OSD_NAME, noneValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_GIVE_PHYSICAL_ADDRESS,
noneValidator, DEST_DIRECT | SRC_UNREGISTERED);
addValidationInfo(Constants.MESSAGE_GIVE_SYSTEM_AUDIO_MODE_STATUS,
noneValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_IMAGE_VIEW_ON, noneValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_INITIATE_ARC, noneValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_RECORD_OFF, noneValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_RECORD_TV_SCREEN, noneValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_REPORT_ARC_INITIATED, noneValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_REPORT_ARC_TERMINATED, noneValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_REQUEST_ARC_INITIATION, noneValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_REQUEST_ARC_TERMINATION, noneValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_REQUEST_ACTIVE_SOURCE,
noneValidator, DEST_BROADCAST | SRC_UNREGISTERED);
addValidationInfo(Constants.MESSAGE_STANDBY, noneValidator, DEST_ALL | SRC_UNREGISTERED);
addValidationInfo(Constants.MESSAGE_TERMINATE_ARC, noneValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_TEXT_VIEW_ON, noneValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_TUNER_STEP_DECREMENT, noneValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_TUNER_STEP_INCREMENT, noneValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_USER_CONTROL_RELEASED, noneValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_VENDOR_REMOTE_BUTTON_UP, noneValidator, DEST_ALL);
// TODO: Validate more than length for the following messages.
// Messages for the One Touch Record.
FixedLengthValidator oneByteValidator = new FixedLengthValidator(1);
addValidationInfo(Constants.MESSAGE_RECORD_ON,
new VariableLengthValidator(1, 8), DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_RECORD_STATUS, oneByteValidator, DEST_DIRECT);
// TODO: Handle messages for the Timer Programming.
// Messages for the System Information.
addValidationInfo(Constants.MESSAGE_CEC_VERSION, oneByteValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_SET_MENU_LANGUAGE,
new FixedLengthValidator(3), DEST_BROADCAST);
// TODO: Handle messages for the Deck Control.
// TODO: Handle messages for the Tuner Control.
// Messages for the Vendor Specific Commands.
VariableLengthValidator maxLengthValidator = new VariableLengthValidator(0, 14);
addValidationInfo(Constants.MESSAGE_DEVICE_VENDOR_ID,
new FixedLengthValidator(3), DEST_BROADCAST);
// Allow unregistered source for all vendor specific commands, because we don't know
// how to use the commands at this moment.
addValidationInfo(Constants.MESSAGE_VENDOR_COMMAND,
maxLengthValidator, DEST_DIRECT | SRC_UNREGISTERED);
addValidationInfo(Constants.MESSAGE_VENDOR_COMMAND_WITH_ID,
new VariableLengthValidator(4, 14), DEST_ALL | SRC_UNREGISTERED);
addValidationInfo(Constants.MESSAGE_VENDOR_REMOTE_BUTTON_DOWN,
maxLengthValidator, DEST_ALL | SRC_UNREGISTERED);
// Messages for the OSD.
addValidationInfo(Constants.MESSAGE_SET_OSD_STRING, maxLengthValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_SET_OSD_NAME, maxLengthValidator, DEST_DIRECT);
// Messages for the Device Menu Control.
addValidationInfo(Constants.MESSAGE_MENU_REQUEST, oneByteValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_MENU_STATUS, oneByteValidator, DEST_DIRECT);
// Messages for the Remote Control Passthrough.
// TODO: Parse the first parameter and determine if it can have the next parameter.
addValidationInfo(Constants.MESSAGE_USER_CONTROL_PRESSED,
new VariableLengthValidator(1, 2), DEST_DIRECT);
// Messages for the Power Status.
addValidationInfo(Constants.MESSAGE_REPORT_POWER_STATUS, oneByteValidator, DEST_DIRECT);
// Messages for the General Protocol.
addValidationInfo(Constants.MESSAGE_FEATURE_ABORT,
new FixedLengthValidator(2), DEST_DIRECT);
// Messages for the System Audio Control.
addValidationInfo(Constants.MESSAGE_REPORT_AUDIO_STATUS, oneByteValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_REPORT_SHORT_AUDIO_DESCRIPTOR,
new FixedLengthValidator(3), DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_REQUEST_SHORT_AUDIO_DESCRIPTOR,
oneByteValidator, DEST_DIRECT);
addValidationInfo(Constants.MESSAGE_SET_SYSTEM_AUDIO_MODE, oneByteValidator, DEST_ALL);
addValidationInfo(Constants.MESSAGE_SYSTEM_AUDIO_MODE_STATUS,
oneByteValidator, DEST_DIRECT);
// Messages for the Audio Rate Control.
addValidationInfo(Constants.MESSAGE_SET_AUDIO_RATE, oneByteValidator, DEST_DIRECT);
// All Messages for the ARC have no parameters.
// Messages for the Capability Discovery and Control.
addValidationInfo(Constants.MESSAGE_CDC_MESSAGE, maxLengthValidator,
DEST_BROADCAST | SRC_UNREGISTERED);
}
private void addValidationInfo(int opcode, ParameterValidator validator, int addrType) {
mValidationInfo.append(opcode, new ValidationInfo(validator, addrType));
}
int isValid(HdmiCecMessage message) {
int opcode = message.getOpcode();
ValidationInfo info = mValidationInfo.get(opcode);
if (info == null) {
HdmiLogger.warning("No validation information for the message: " + message);
return OK;
}
// Check the source field.
if (message.getSource() == Constants.ADDR_UNREGISTERED &&
(info.addressType & SRC_UNREGISTERED) == 0) {
HdmiLogger.warning("Unexpected source: " + message);
return ERROR_SOURCE;
}
// Check the destination field.
if (message.getDestination() == Constants.ADDR_BROADCAST) {
if ((info.addressType & DEST_BROADCAST) == 0) {
HdmiLogger.warning("Unexpected broadcast message: " + message);
return ERROR_DESTINATION;
}
} else { // Direct addressing.
if ((info.addressType & DEST_DIRECT) == 0) {
HdmiLogger.warning("Unexpected direct message: " + message);
return ERROR_DESTINATION;
}
}
// Check the parameter type.
int errorCode = info.parameterValidator.isValid(message.getParams());
if (errorCode != OK) {
HdmiLogger.warning("Unexpected parameters: " + message);
return errorCode;
}
return OK;
}
private static class FixedLengthValidator implements ParameterValidator {
private final int mLength;
public FixedLengthValidator(int length) {
mLength = length;
}
@Override
public int isValid(byte[] params) {
// If the length is longer than expected, we assume it's OK since the parameter can be
// extended in the future version.
return params.length < mLength ? ERROR_PARAMETER_SHORT : OK;
}
}
private static class VariableLengthValidator implements ParameterValidator {
private final int mMinLength;
private final int mMaxLength;
public VariableLengthValidator(int minLength, int maxLength) {
mMinLength = minLength;
mMaxLength = maxLength;
}
@Override
public int isValid(byte[] params) {
return params.length < mMinLength ? ERROR_PARAMETER_SHORT : OK;
}
}
private boolean isValidPhysicalAddress(byte[] params, int offset) {
// TODO: Add more logic like validating 1.0.1.0.
if (!mService.isTvDevice()) {
// If the device is not TV, we can't convert path to port-id, so stop here.
return true;
}
int path = HdmiUtils.twoBytesToInt(params, offset);
if (path != Constants.INVALID_PHYSICAL_ADDRESS && path == mService.getPhysicalAddress()) {
return true;
}
int portId = mService.pathToPortId(path);
if (portId == Constants.INVALID_PORT_ID) {
return false;
}
return true;
}
/**
* Check if the given type is valid. A valid type is one of the actual logical device types
* defined in the standard ({@link HdmiDeviceInfo#DEVICE_TV},
* {@link HdmiDeviceInfo#DEVICE_PLAYBACK}, {@link HdmiDeviceInfo#DEVICE_TUNER},
* {@link HdmiDeviceInfo#DEVICE_RECORDER}, and {@link HdmiDeviceInfo#DEVICE_AUDIO_SYSTEM}).
*
* @param type device type
* @return true if the given type is valid
*/
static boolean isValidType(int type) {
return (HdmiDeviceInfo.DEVICE_TV <= type
&& type <= HdmiDeviceInfo.DEVICE_VIDEO_PROCESSOR)
&& type != HdmiDeviceInfo.DEVICE_RESERVED;
}
private static int toErrorCode(boolean success) {
return success ? OK : ERROR_PARAMETER;
}
private class PhysicalAddressValidator implements ParameterValidator {
@Override
public int isValid(byte[] params) {
if (params.length < 2) {
return ERROR_PARAMETER_SHORT;
}
return toErrorCode(isValidPhysicalAddress(params, 0));
}
}
private class SystemAudioModeRequestValidator extends PhysicalAddressValidator {
@Override
public int isValid(byte[] params) {
// TV can send <System Audio Mode Request> with no parameters to terminate system audio.
if (params.length == 0) {
return OK;
}
return super.isValid(params);
}
}
private class ReportPhysicalAddressValidator implements ParameterValidator {
@Override
public int isValid(byte[] params) {
if (params.length < 3) {
return ERROR_PARAMETER_SHORT;
}
return toErrorCode(isValidPhysicalAddress(params, 0) && isValidType(params[2]));
}
}
private class RoutingChangeValidator implements ParameterValidator {
@Override
public int isValid(byte[] params) {
if (params.length < 4) {
return ERROR_PARAMETER_SHORT;
}
return toErrorCode(
isValidPhysicalAddress(params, 0) && isValidPhysicalAddress(params, 2));
}
}
}
|
