qdbusutil.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
 
#include "qdbusutil_p.h"
 
#include "qdbus_symbols_p.h"
 
#include <QtCore/qlist.h>
#include <QtCore/qstringlist.h>
#include <private/qtools_p.h>
 
#include "qdbusargument.h"
#include "qdbusunixfiledescriptor.h"
 
#ifndef QT_NO_DBUS
 
QT_BEGIN_NAMESPACE
 
using namespace Qt::StringLiterals;
using namespace QtMiscUtils;
 
static inline bool isValidCharacterNoDash(QChar c)
{
    ushort u = c.unicode();
    return isAsciiLetterOrNumber(u) || (u == '_');
}
 
static inline bool isValidCharacter(QChar c)
{
    ushort u = c.unicode();
    return isAsciiLetterOrNumber(u)
            || (u == '_') || (u == '-');
}
 
static inline bool isValidNumber(QChar c)
{
    return (isAsciiDigit(c.toLatin1()));
}
 
#ifndef QT_BOOTSTRAPPED
static bool argToString(const QDBusArgument &arg, QString &out);
 
static bool variantToString(const QVariant &arg, QString &out)
{
    int argType = arg.metaType().id();
 
    if (argType == QMetaType::QStringList) {
        out += u'{';
        const QStringList list = arg.toStringList();
        for (const QString &item : list)
            out += u'\"' + item + "\", "_L1;
        if (!list.isEmpty())
            out.chop(2);
        out += u'}';
    } else if (argType == QMetaType::QByteArray) {
        out += u'{';
        QByteArray list = arg.toByteArray();
        for (int i = 0; i < list.size(); ++i) {
            out += QString::number(list.at(i));
            out += ", "_L1;
        }
        if (!list.isEmpty())
            out.chop(2);
        out += u'}';
    } else if (argType == QMetaType::QVariantList) {
        out += u'{';
        const QList<QVariant> list = arg.toList();
        for (const QVariant &item : list) {
            if (!variantToString(item, out))
                return false;
            out += ", "_L1;
        }
        if (!list.isEmpty())
            out.chop(2);
        out += u'}';
    } else if (argType == QMetaType::Char || argType == QMetaType::Short || argType == QMetaType::Int
               || argType == QMetaType::Long || argType == QMetaType::LongLong) {
        out += QString::number(arg.toLongLong());
    } else if (argType == QMetaType::UChar || argType == QMetaType::UShort || argType == QMetaType::UInt
               || argType == QMetaType::ULong || argType == QMetaType::ULongLong) {
        out += QString::number(arg.toULongLong());
    } else if (argType == QMetaType::Double) {
        out += QString::number(arg.toDouble());
    } else if (argType == QMetaType::Bool) {
        out += arg.toBool() ? "true"_L1 : "false"_L1;
    } else if (argType == qMetaTypeId<QDBusArgument>()) {
        argToString(qvariant_cast<QDBusArgument>(arg), out);
    } else if (argType == qMetaTypeId<QDBusObjectPath>()) {
        const QString path = qvariant_cast<QDBusObjectPath>(arg).path();
        out += "[ObjectPath: "_L1;
        out += path;
        out += u']';
    } else if (argType == qMetaTypeId<QDBusSignature>()) {
        out += "[Signature: "_L1 + qvariant_cast<QDBusSignature>(arg).signature();
        out += u']';
    } else if (argType == qMetaTypeId<QDBusUnixFileDescriptor>()) {
        out += "[Unix FD: "_L1;
        out += qvariant_cast<QDBusUnixFileDescriptor>(arg).isValid() ? "valid"_L1 : "not valid"_L1;
        out += u']';
    } else if (argType == qMetaTypeId<QDBusVariant>()) {
        const QVariant v = qvariant_cast<QDBusVariant>(arg).variant();
        out += "[Variant"_L1;
        QMetaType vUserType = v.metaType();
        if (vUserType != QMetaType::fromType<QDBusVariant>()
                && vUserType != QMetaType::fromType<QDBusSignature>()
                && vUserType != QMetaType::fromType<QDBusObjectPath>()
                && vUserType != QMetaType::fromType<QDBusArgument>())
            out += u'(' + QLatin1StringView(v.typeName()) + u')';
        out += ": "_L1;
        if (!variantToString(v, out))
            return false;
        out += u']';
    } else if (arg.canConvert<QString>()) {
        out += u'\"' + arg.toString() + u'\"';
    } else {
        out += u'[';
        out += QLatin1StringView(arg.typeName());
        out += u']';
    }
 
    return true;
}
 
bool argToString(const QDBusArgument &busArg, QString &out)
{
    QString busSig = busArg.currentSignature();
    bool doIterate = false;
    QDBusArgument::ElementType elementType = busArg.currentType();
 
    if (elementType != QDBusArgument::BasicType && elementType != QDBusArgument::VariantType
            && elementType != QDBusArgument::MapEntryType)
        out += "[Argument: "_L1 + busSig + u' ';
 
    switch (elementType) {
        case QDBusArgument::BasicType:
        case QDBusArgument::VariantType:
            if (!variantToString(busArg.asVariant(), out))
                return false;
            break;
        case QDBusArgument::StructureType:
            busArg.beginStructure();
            doIterate = true;
            break;
        case QDBusArgument::ArrayType:
            busArg.beginArray();
            out += u'{';
            doIterate = true;
            break;
        case QDBusArgument::MapType:
            busArg.beginMap();
            out += u'{';
            doIterate = true;
            break;
        case QDBusArgument::MapEntryType:
            busArg.beginMapEntry();
            if (!variantToString(busArg.asVariant(), out))
                return false;
            out += " = "_L1;
            if (!argToString(busArg, out))
                return false;
            busArg.endMapEntry();
            break;
        case QDBusArgument::UnknownType:
        default:
            out += "<ERROR - Unknown Type>"_L1;
            return false;
    }
    if (doIterate && !busArg.atEnd()) {
        while (!busArg.atEnd()) {
            if (!argToString(busArg, out))
                return false;
            out += ", "_L1;
        }
        out.chop(2);
    }
    switch (elementType) {
        case QDBusArgument::BasicType:
        case QDBusArgument::VariantType:
        case QDBusArgument::UnknownType:
        case QDBusArgument::MapEntryType:
            // nothing to do
            break;
        case QDBusArgument::StructureType:
            busArg.endStructure();
            break;
        case QDBusArgument::ArrayType:
            out += u'}';
            busArg.endArray();
            break;
        case QDBusArgument::MapType:
            out += u'}';
            busArg.endMap();
            break;
    }
 
    if (elementType != QDBusArgument::BasicType && elementType != QDBusArgument::VariantType
            && elementType != QDBusArgument::MapEntryType)
        out += u']';
 
    return true;
}
#endif
 
//------- D-Bus Types --------
static const char oneLetterTypes[] = "vsogybnqiuxtdh";
static const char basicTypes[] =      "sogybnqiuxtdh";
static const char fixedTypes[] =         "ybnqiuxtdh";
 
/*
    D-Bus signature grammar (in ABNF), as of 0.42 (2023-08-21):
    https://dbus.freedesktop.org/doc/dbus-specification.html#type-system
 
    <signature>            = *<single-complete-type>
    <single-complete-type> = <basic-type> / <variant> / <struct> / <array>
    <fixed-type>           = "y" / "b" / "n" / "q" / "i" / "u" / "x" / "t" / "d" / "h"
    <variable-length-type> = "s" / "o" / "g"
    <basic-type>           = <variable-length-type> / <fixed-type>
    <variant>              = "v"
    <struct>               = "(" 1*<single-complete-type> ")"
    <array>                = "a" ( <single-complete-type> / <dict-entry> )
    <dict-entry>           = "{" <basic-type> <single-complete-type> "}"
*/
 
static bool isBasicType(int c)
{
    return c != DBUS_TYPE_INVALID && strchr(basicTypes, c) != nullptr;
}
 
static bool isFixedType(int c)
{
    return c != DBUS_TYPE_INVALID && strchr(fixedTypes, c) != nullptr;
}
 
// Returns a pointer to one-past-end of this type if it's valid;
// returns NULL if it isn't valid.
static const char *validateSingleType(const char *signature)
{
    char c = *signature;
    if (c == DBUS_TYPE_INVALID)
        return nullptr;
 
    // is it one of the one-letter types?
    if (strchr(oneLetterTypes, c) != nullptr)
        return signature + 1;
 
    // is it an array?
    if (c == DBUS_TYPE_ARRAY) {
        // then it's valid if the next type is valid
        // or if it's a dict-entry
        c = *++signature;
        if (c == DBUS_DICT_ENTRY_BEGIN_CHAR) {
            // beginning of a dictionary entry
            // a dictionary entry has a key which is of basic types
            // and a free value
            c = *++signature;
            if (!isBasicType(c))
                return nullptr;
            signature = validateSingleType(signature + 1);
            return signature && *signature == DBUS_DICT_ENTRY_END_CHAR ? signature + 1 : nullptr;
        }
 
        return validateSingleType(signature);
    }
 
    if (c == DBUS_STRUCT_BEGIN_CHAR) {
        // beginning of a struct
        ++signature;
        while (true) {
            signature = validateSingleType(signature);
            if (!signature)
                return nullptr;
            if (*signature == DBUS_STRUCT_END_CHAR)
                return signature + 1;
        }
    }
 
    // invalid/unknown type
    return nullptr;
}
 
namespace QDBusUtil
{
    QString argumentToString(const QVariant &arg)
    {
        QString out;
 
#ifndef QT_BOOTSTRAPPED
        variantToString(arg, out);
#else
        Q_UNUSED(arg);
#endif
 
        return out;
    }
 
    bool isValidPartOfObjectPath(QStringView part)
    {
        if (part.isEmpty())
            return false;       // can't be valid if it's empty
 
        const QChar *c = part.data();
        for (int i = 0; i < part.size(); ++i)
            if (!isValidCharacterNoDash(c[i]))
                return false;
 
        return true;
    }
 
    bool isValidInterfaceName(const QString& ifaceName)
    {
        if (ifaceName.isEmpty() || ifaceName.size() > DBUS_MAXIMUM_NAME_LENGTH)
            return false;
 
        const auto parts = QStringView{ifaceName}.split(u'.');
        if (parts.size() < 2)
            return false;           // at least two parts
 
        for (auto part : parts)
            if (!isValidMemberName(part))
                return false;
 
        return true;
    }
 
    bool isValidUniqueConnectionName(QStringView connName)
    {
        if (connName.isEmpty() || connName.size() > DBUS_MAXIMUM_NAME_LENGTH ||
            !connName.startsWith(u':'))
            return false;
 
        const auto parts = connName.mid(1).split(u'.');
        if (parts.size() < 1)
            return false;
 
        for (QStringView part : parts) {
            if (part.isEmpty())
                 return false;
 
            const QChar* c = part.data();
            for (int j = 0; j < part.size(); ++j)
                if (!isValidCharacter(c[j]))
                    return false;
        }
 
        return true;
    }
 
    bool isValidBusName(const QString &busName)
    {
        if (busName.isEmpty() || busName.size() > DBUS_MAXIMUM_NAME_LENGTH)
            return false;
 
        if (busName.startsWith(u':'))
            return isValidUniqueConnectionName(busName);
 
        const auto parts = QStringView{busName}.split(u'.');
        for (QStringView part : parts) {
            if (part.isEmpty())
                return false;
 
            const QChar *c = part.data();
            if (isValidNumber(c[0]))
                return false;
            for (int j = 0; j < part.size(); ++j)
                if (!isValidCharacter(c[j]))
                    return false;
        }
 
        return true;
    }
 
    bool isValidMemberName(QStringView memberName)
    {
        if (memberName.isEmpty() || memberName.size() > DBUS_MAXIMUM_NAME_LENGTH)
            return false;
 
        const QChar* c = memberName.data();
        if (isValidNumber(c[0]))
            return false;
        for (int j = 0; j < memberName.size(); ++j)
            if (!isValidCharacterNoDash(c[j]))
                return false;
        return true;
    }
 
    bool isValidErrorName(const QString &errorName)
    {
        return isValidInterfaceName(errorName);
    }
 
    bool isValidObjectPath(const QString &path)
    {
        if (path == "/"_L1)
            return true;
 
        if (!path.startsWith(u'/') || path.indexOf("//"_L1) != -1 ||
            path.endsWith(u'/'))
            return false;
 
        // it starts with /, so we skip the empty first part
        const auto parts = QStringView{path}.mid(1).split(u'/');
        for (QStringView part : parts)
            if (!isValidPartOfObjectPath(part))
                return false;
 
        return true;
    }
 
    bool isValidBasicType(int c)
    {
        return isBasicType(c);
    }
 
    bool isValidFixedType(int c)
    {
        return isFixedType(c);
    }
 
 
    bool isValidSignature(const QString &signature)
    {
        QByteArray ba = signature.toLatin1();
        const char *data = ba.constBegin();
        const char *end = ba.constEnd();
        while (data != end) {
            data = validateSingleType(data);
            if (!data)
                return false;
        }
        return true;
    }
 
    bool isValidSingleSignature(const QString &signature)
    {
        QByteArray ba = signature.toLatin1();
        const char *data = validateSingleType(ba.constData());
        return data && *data == '\0';
    }
 
} // namespace QDBusUtil
 
QT_END_NAMESPACE
 
#endif // QT_NO_DBUS