qdbusxmlparser.cpp

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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
// Qt-Security score:critical reason:data-parser
 
#include "qdbusxmlparser_p.h"
#include "qdbusutil_p.h"
 
#include <QtCore/qmap.h>
#include <QtCore/qvariant.h>
#include <QtCore/qtextstream.h>
#include <QtCore/qdebug.h>
 
#ifndef QT_NO_DBUS
 
QT_BEGIN_NAMESPACE
 
using namespace Qt::StringLiterals;
 
Q_LOGGING_CATEGORY(dbusParser, "dbus.parser", QtWarningMsg)
 
#define qDBusParserWarning(format, ...)
    do {
        if (m_reporter)
            m_reporter->warning(m_currentLocation, format "\n", ##__VA_ARGS__);
        else
            qCDebug(dbusParser, "Warning: " format, ##__VA_ARGS__);
    } while (0)
 
#define qDBusParserError(format, ...)
    do {
        if (m_reporter)
            m_reporter->error(m_currentLocation, format "\n", ##__VA_ARGS__);
        else
            qCDebug(dbusParser, "Error: " format, ##__VA_ARGS__);
    } while (0)
 
bool QDBusXmlParser::parseArg(const QXmlStreamAttributes &attributes,
                              QDBusIntrospection::Argument &argData)
{
    Q_ASSERT(m_currentInterface);
 
    const QString argType = attributes.value("type"_L1).toString();
 
    bool ok = QDBusUtil::isValidSingleSignature(argType);
    if (!ok) {
        qDBusParserError("Invalid D-Bus type signature '%s' found while parsing introspection",
                         qPrintable(argType));
    }
 
    argData.name = attributes.value("name"_L1).toString();
    argData.type = argType;
 
    m_currentInterface->introspection += "      <arg"_L1;
    if (attributes.hasAttribute("direction"_L1)) {
        const QString direction = attributes.value("direction"_L1).toString();
        m_currentInterface->introspection += " direction=\""_L1 + direction + u'"';
    }
    m_currentInterface->introspection += " type=\""_L1 + argData.type + u'"';
    if (!argData.name.isEmpty())
        m_currentInterface->introspection += " name=\""_L1 + argData.name + u'"';
    m_currentInterface->introspection += "/>\n"_L1;
 
    return ok;
}
 
bool QDBusXmlParser::parseAnnotation(QDBusIntrospection::Annotations &annotations,
                                     bool interfaceAnnotation)
{
    Q_ASSERT(m_currentInterface);
    Q_ASSERT(m_xml.isStartElement() && m_xml.name() == "annotation"_L1);
 
    QDBusIntrospection::Annotation annotation;
    annotation.location = m_currentLocation;
 
    const QXmlStreamAttributes attributes = m_xml.attributes();
    annotation.name = attributes.value("name"_L1).toString();
 
    if (!QDBusUtil::isValidInterfaceName(annotation.name)) {
        qDBusParserError("Invalid D-Bus annotation '%s' found while parsing introspection",
                         qPrintable(annotation.name));
        return false;
    }
    annotation.value = attributes.value("value"_L1).toString();
    annotations.insert(annotation.name, annotation);
    if (!interfaceAnnotation)
        m_currentInterface->introspection += "  "_L1;
    m_currentInterface->introspection += "    <annotation value=\""_L1
            + annotation.value.toHtmlEscaped() + "\" name=\""_L1 + annotation.name + "\"/>\n"_L1;
    return true;
}
 
bool QDBusXmlParser::parseProperty(QDBusIntrospection::Property &propertyData)
{
    Q_ASSERT(m_currentInterface);
    Q_ASSERT(m_xml.isStartElement() && m_xml.name() == "property"_L1);
 
    QXmlStreamAttributes attributes = m_xml.attributes();
    const QString propertyName = attributes.value("name"_L1).toString();
    if (!QDBusUtil::isValidMemberName(propertyName)) {
        qDBusParserWarning("Invalid D-Bus member name '%s' found in interface '%s' while parsing "
                           "introspection",
                           qPrintable(propertyName), qPrintable(m_currentInterface->name));
        m_xml.skipCurrentElement();
        return false;
    }
 
    // parse data
    propertyData.name = propertyName;
    propertyData.type = attributes.value("type"_L1).toString();
 
    if (!QDBusUtil::isValidSingleSignature(propertyData.type)) {
        // cannot be!
        qDBusParserError("Invalid D-Bus type signature '%s' found in property '%s.%s' while "
                         "parsing introspection",
                         qPrintable(propertyData.type), qPrintable(m_currentInterface->name),
                         qPrintable(propertyName));
    }
 
    const QString access = attributes.value("access"_L1).toString();
    if (access == "read"_L1)
        propertyData.access = QDBusIntrospection::Property::Read;
    else if (access == "write"_L1)
        propertyData.access = QDBusIntrospection::Property::Write;
    else if (access == "readwrite"_L1)
        propertyData.access = QDBusIntrospection::Property::ReadWrite;
    else {
        qDBusParserError("Invalid D-Bus property access '%s' found in property '%s.%s' while "
                         "parsing introspection",
                         qPrintable(access), qPrintable(m_currentInterface->name),
                         qPrintable(propertyName));
        return false;       // invalid one!
    }
 
    m_currentInterface->introspection += "    <property access=\""_L1 + access + "\" type=\""_L1 + propertyData.type + "\" name=\""_L1 + propertyName + u'"';
 
    if (!readNextStartElement()) {
        m_currentInterface->introspection += "/>\n"_L1;
    } else {
        m_currentInterface->introspection += ">\n"_L1;
 
        do {
            if (m_xml.name() == "annotation"_L1) {
                parseAnnotation(propertyData.annotations);
            } else if (m_xml.prefix().isEmpty()) {
                qDBusParserWarning("Unknown element '%s' while checking for annotations",
                                   qPrintable(m_xml.name().toString()));
            }
            m_xml.skipCurrentElement();
        } while (readNextStartElement());
 
        m_currentInterface->introspection += "    </property>\n"_L1;
    }
 
    if (!m_xml.isEndElement() || m_xml.name() != "property"_L1) {
        qDBusParserError("Invalid property specification: '%s'", qPrintable(m_xml.tokenString()));
        return false;
    }
 
    return true;
}
 
bool QDBusXmlParser::parseMethod(QDBusIntrospection::Method &methodData)
{
    Q_ASSERT(m_currentInterface);
    Q_ASSERT(m_xml.isStartElement() && m_xml.name() == "method"_L1);
 
    const QXmlStreamAttributes attributes = m_xml.attributes();
    const QString methodName = attributes.value("name"_L1).toString();
    if (!QDBusUtil::isValidMemberName(methodName)) {
        qDBusParserError("Invalid D-Bus member name '%s' found in interface '%s' while parsing "
                         "introspection",
                         qPrintable(methodName), qPrintable(m_currentInterface->name));
        return false;
    }
 
    methodData.name = methodName;
    m_currentInterface->introspection += "    <method name=\""_L1 + methodName + u'"';
 
    QDBusIntrospection::Arguments outArguments;
    QDBusIntrospection::Arguments inArguments;
    QDBusIntrospection::Annotations annotations;
 
    if (!readNextStartElement()) {
        m_currentInterface->introspection += "/>\n"_L1;
    } else {
        m_currentInterface->introspection += ">\n"_L1;
 
        do {
            if (m_xml.name() == "annotation"_L1) {
                parseAnnotation(annotations);
            } else if (m_xml.name() == "arg"_L1) {
                const QXmlStreamAttributes attributes = m_xml.attributes();
                const QString direction = attributes.value("direction"_L1).toString();
                QDBusIntrospection::Argument argument;
                argument.location = m_currentLocation;
                if (!attributes.hasAttribute("direction"_L1) || direction == "in"_L1) {
                    parseArg(attributes, argument);
                    inArguments << argument;
                } else if (direction == "out"_L1) {
                    parseArg(attributes, argument);
                    outArguments << argument;
                }
            } else if (m_xml.prefix().isEmpty()) {
                qDBusParserWarning("Unknown element '%s' while checking for method arguments",
                                   qPrintable(m_xml.name().toString()));
            }
            m_xml.skipCurrentElement();
        } while (readNextStartElement());
 
        m_currentInterface->introspection += "    </method>\n"_L1;
    }
 
    methodData.inputArgs = inArguments;
    methodData.outputArgs = outArguments;
    methodData.annotations = annotations;
 
    return true;
}
 
bool QDBusXmlParser::parseSignal(QDBusIntrospection::Signal &signalData)
{
    Q_ASSERT(m_currentInterface);
    Q_ASSERT(m_xml.isStartElement() && m_xml.name() == "signal"_L1);
 
    const QXmlStreamAttributes attributes = m_xml.attributes();
    const QString signalName = attributes.value("name"_L1).toString();
 
    if (!QDBusUtil::isValidMemberName(signalName)) {
        qDBusParserError("Invalid D-Bus member name '%s' found in interface '%s' while parsing "
                         "introspection",
                         qPrintable(signalName), qPrintable(m_currentInterface->name));
        return false;
    }
 
    signalData.name = signalName;
    m_currentInterface->introspection += "    <signal name=\""_L1 + signalName + u'"';
 
    QDBusIntrospection::Arguments arguments;
    QDBusIntrospection::Annotations annotations;
 
    if (!readNextStartElement()) {
        m_currentInterface->introspection += "/>\n"_L1;
    } else {
        m_currentInterface->introspection += ">\n"_L1;
 
        do {
            if (m_xml.name() == "annotation"_L1) {
                parseAnnotation(annotations);
            } else if (m_xml.name() == "arg"_L1) {
                const QXmlStreamAttributes attributes = m_xml.attributes();
                QDBusIntrospection::Argument argument;
                argument.location = m_currentLocation;
                if (!attributes.hasAttribute("direction"_L1) ||
                    attributes.value("direction"_L1) == "out"_L1) {
                    parseArg(attributes, argument);
                    arguments << argument;
                }
            } else {
                qDBusParserWarning("Unknown element '%s' while checking for signal arguments",
                                   qPrintable(m_xml.name().toString()));
            }
            m_xml.skipCurrentElement();
        } while (readNextStartElement());
 
        m_currentInterface->introspection += "    </signal>\n"_L1;
    }
 
    signalData.outputArgs = arguments;
    signalData.annotations = annotations;
 
    return true;
}
 
void QDBusXmlParser::readInterface()
{
    Q_ASSERT(!m_currentInterface);
 
    const QString ifaceName = m_xml.attributes().value("name"_L1).toString();
    if (!QDBusUtil::isValidInterfaceName(ifaceName)) {
        qDBusParserError("Invalid D-Bus interface name '%s' found while parsing introspection",
                         qPrintable(ifaceName));
        return;
    }
 
    m_object->interfaces.append(ifaceName);
 
    m_currentInterface = std::make_unique<QDBusIntrospection::Interface>();
    m_currentInterface->location = m_currentLocation;
    m_currentInterface->name = ifaceName;
    m_currentInterface->introspection += "  <interface name=\""_L1 + ifaceName + "\">\n"_L1;
 
    while (readNextStartElement()) {
        if (m_xml.name() == "method"_L1) {
            QDBusIntrospection::Method methodData;
            methodData.location = m_currentLocation;
            if (parseMethod(methodData))
                m_currentInterface->methods.insert(methodData.name, methodData);
        } else if (m_xml.name() == "signal"_L1) {
            QDBusIntrospection::Signal signalData;
            signalData.location = m_currentLocation;
            if (parseSignal(signalData))
                m_currentInterface->signals_.insert(signalData.name, signalData);
        } else if (m_xml.name() == "property"_L1) {
            QDBusIntrospection::Property propertyData;
            propertyData.location = m_currentLocation;
            if (parseProperty(propertyData))
                m_currentInterface->properties.insert(propertyData.name, propertyData);
        } else if (m_xml.name() == "annotation"_L1) {
            parseAnnotation(m_currentInterface->annotations, true);
            m_xml.skipCurrentElement(); // skip over annotation object
        } else {
            if (m_xml.prefix().isEmpty()) {
                qDBusParserWarning("Unknown element '%s' while parsing interface",
                                   qPrintable(m_xml.name().toString()));
            }
            m_xml.skipCurrentElement();
        }
    }
 
    m_currentInterface->introspection += "  </interface>"_L1;
 
    m_interfaces.insert(
            ifaceName,
            QSharedDataPointer<QDBusIntrospection::Interface>(m_currentInterface.release()));
 
    if (!m_xml.isEndElement() || m_xml.name() != "interface"_L1) {
        qDBusParserError("Invalid Interface specification");
    }
}
 
void QDBusXmlParser::readNode(int nodeLevel)
{
    const QString objName = m_xml.attributes().value("name"_L1).toString();
    QString fullName = m_object->path;
    if (!(fullName.endsWith(u'/') || (nodeLevel == 0 && objName.startsWith(u'/'))))
        fullName.append(u'/');
    fullName += objName;
 
    if (!QDBusUtil::isValidObjectPath(fullName)) {
        qDBusParserError("Invalid D-Bus object path '%s' found while parsing introspection",
                         qPrintable(fullName));
        return;
    }
 
    if (nodeLevel > 0)
        m_object->childObjects.append(objName);
    else
        m_object->location = m_currentLocation;
}
 
void QDBusXmlParser::updateCurrentLocation()
{
    m_currentLocation =
            QDBusIntrospection::SourceLocation{ m_xml.lineNumber(), m_xml.columnNumber() };
}
 
// Similar to m_xml.readNextElement() but sets current location to point
// to the start element.
bool QDBusXmlParser::readNextStartElement()
{
    updateCurrentLocation();
 
    while (m_xml.readNext() != QXmlStreamReader::Invalid) {
        if (m_xml.isEndElement())
            return false;
        else if (m_xml.isStartElement())
            return true;
        updateCurrentLocation();
    }
    return false;
}
 
QDBusXmlParser::QDBusXmlParser(const QString &service, const QString &path, const QString &xmlData,
                               QDBusIntrospection::DiagnosticsReporter *reporter)
    : m_service(service),
      m_path(path),
      m_object(new QDBusIntrospection::Object),
      m_xml(xmlData),
      m_reporter(reporter)
{
    m_object->service = m_service;
    m_object->path = m_path;
 
    int nodeLevel = -1;
 
    while (!m_xml.atEnd()) {
        updateCurrentLocation();
        m_xml.readNext();
 
        switch (m_xml.tokenType()) {
        case QXmlStreamReader::StartElement:
            if (m_xml.name() == "node"_L1) {
                readNode(++nodeLevel);
            } else if (m_xml.name() == "interface"_L1) {
                readInterface();
            } else {
                if (m_xml.prefix().isEmpty()) {
                    qDBusParserWarning("Skipping unknown element '%s'",
                                       qPrintable(m_xml.name().toString()));
                }
                m_xml.skipCurrentElement();
            }
            break;
        case QXmlStreamReader::EndElement:
            if (m_xml.name() == "node"_L1) {
                --nodeLevel;
            } else {
                qDBusParserError("Invalid node declaration '%s'",
                                 qPrintable(m_xml.name().toString()));
            }
            break;
        case QXmlStreamReader::StartDocument:
        case QXmlStreamReader::EndDocument:
        case QXmlStreamReader::DTD:
            // not interested
            break;
        case QXmlStreamReader::Comment:
            // ignore comments and processing instructions
            break;
        case QXmlStreamReader::Characters:
            // ignore whitespace
            if (m_xml.isWhitespace())
                break;
            Q_FALLTHROUGH();
        default:
            qDBusParserError("Unknown token: '%s'", qPrintable(m_xml.tokenString()));
            break;
        }
    }
 
    if (m_xml.hasError())
        qDBusParserError("XML error: %s", qPrintable(m_xml.errorString()));
}
 
QT_END_NAMESPACE
 
#endif // QT_NO_DBUS