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| ****************************************************************************/ |
| |
| |
| #define QT_NO_CAST_FROM_ASCII |
| |
| #include "qmimemagicrule_p.h" |
| |
| #include "qmimetypeparser_p.h" |
| #include <QtCore/QList> |
| #include <QtCore/QDebug> |
| #include <qendian.h> |
| |
| QT_BEGIN_NAMESPACE |
| |
| // in the same order as Type! |
| static const char magicRuleTypes_string[] = |
| "invalid\0" |
| "string\0" |
| "host16\0" |
| "host32\0" |
| "big16\0" |
| "big32\0" |
| "little16\0" |
| "little32\0" |
| "byte\0" |
| "\0"; |
| |
| static const int magicRuleTypes_indices[] = { |
| 0, 8, 15, 22, 29, 35, 41, 50, 59, 64, 0 |
| }; |
| |
| QMimeMagicRule::Type QMimeMagicRule::type(const QByteArray &theTypeName) |
| { |
| for (int i = String; i <= Byte; ++i) { |
| if (theTypeName == magicRuleTypes_string + magicRuleTypes_indices[i]) |
| return Type(i); |
| } |
| return Invalid; |
| } |
| |
| QByteArray QMimeMagicRule::typeName(QMimeMagicRule::Type theType) |
| { |
| return magicRuleTypes_string + magicRuleTypes_indices[theType]; |
| } |
| |
| bool QMimeMagicRule::operator==(const QMimeMagicRule &other) const |
| { |
| return m_type == other.m_type && |
| m_value == other.m_value && |
| m_startPos == other.m_startPos && |
| m_endPos == other.m_endPos && |
| m_mask == other.m_mask && |
| m_pattern == other.m_pattern && |
| m_number == other.m_number && |
| m_numberMask == other.m_numberMask && |
| m_matchFunction == other.m_matchFunction; |
| } |
| |
| // Used by both providers |
| bool QMimeMagicRule::matchSubstring(const char *dataPtr, int dataSize, int rangeStart, int rangeLength, |
| int valueLength, const char *valueData, const char *mask) |
| { |
| // Size of searched data. |
| // Example: value="ABC", rangeLength=3 -> we need 3+3-1=5 bytes (ABCxx,xABCx,xxABC would match) |
| const int dataNeeded = qMin(rangeLength + valueLength - 1, dataSize - rangeStart); |
| |
| if (!mask) { |
| // callgrind says QByteArray::indexOf is much slower, since our strings are typically too |
| // short for be worth Boyer-Moore matching (1 to 71 bytes, 11 bytes on average). |
| bool found = false; |
| for (int i = rangeStart; i < rangeStart + rangeLength; ++i) { |
| if (i + valueLength > dataSize) |
| break; |
| |
| if (memcmp(valueData, dataPtr + i, valueLength) == 0) { |
| found = true; |
| break; |
| } |
| } |
| if (!found) |
| return false; |
| } else { |
| bool found = false; |
| const char *readDataBase = dataPtr + rangeStart; |
| // Example (continued from above): |
| // deviceSize is 4, so dataNeeded was max'ed to 4. |
| // maxStartPos = 4 - 3 + 1 = 2, and indeed |
| // we need to check for a match a positions 0 and 1 (ABCx and xABC). |
| const int maxStartPos = dataNeeded - valueLength + 1; |
| for (int i = 0; i < maxStartPos; ++i) { |
| const char *d = readDataBase + i; |
| bool valid = true; |
| for (int idx = 0; idx < valueLength; ++idx) { |
| if (((*d++) & mask[idx]) != (valueData[idx] & mask[idx])) { |
| valid = false; |
| break; |
| } |
| } |
| if (valid) |
| found = true; |
| } |
| if (!found) |
| return false; |
| } |
| //qDebug() << "Found" << value << "in" << searchedData; |
| return true; |
| } |
| |
| bool QMimeMagicRule::matchString(const QByteArray &data) const |
| { |
| const int rangeLength = m_endPos - m_startPos + 1; |
| return QMimeMagicRule::matchSubstring(data.constData(), data.size(), m_startPos, rangeLength, m_pattern.size(), m_pattern.constData(), m_mask.constData()); |
| } |
| |
| template <typename T> |
| bool QMimeMagicRule::matchNumber(const QByteArray &data) const |
| { |
| const T value(m_number); |
| const T mask(m_numberMask); |
| |
| //qDebug() << "matchNumber" << "0x" << QString::number(m_number, 16) << "size" << sizeof(T); |
| //qDebug() << "mask" << QString::number(m_numberMask, 16); |
| |
| const char *p = data.constData() + m_startPos; |
| const char *e = data.constData() + qMin(data.size() - int(sizeof(T)), m_endPos); |
| for ( ; p <= e; ++p) { |
| if ((qFromUnaligned<T>(p) & mask) == (value & mask)) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static inline QByteArray makePattern(const QByteArray &value) |
| { |
| QByteArray pattern(value.size(), Qt::Uninitialized); |
| char *data = pattern.data(); |
| |
| const char *p = value.constData(); |
| const char *e = p + value.size(); |
| for ( ; p < e; ++p) { |
| if (*p == '\\' && ++p < e) { |
| if (*p == 'x') { // hex (\\xff) |
| char c = 0; |
| for (int i = 0; i < 2 && p + 1 < e; ++i) { |
| ++p; |
| if (*p >= '0' && *p <= '9') |
| c = (c << 4) + *p - '0'; |
| else if (*p >= 'a' && *p <= 'f') |
| c = (c << 4) + *p - 'a' + 10; |
| else if (*p >= 'A' && *p <= 'F') |
| c = (c << 4) + *p - 'A' + 10; |
| else |
| continue; |
| } |
| *data++ = c; |
| } else if (*p >= '0' && *p <= '7') { // oct (\\7, or \\77, or \\377) |
| char c = *p - '0'; |
| if (p + 1 < e && p[1] >= '0' && p[1] <= '7') { |
| c = (c << 3) + *(++p) - '0'; |
| if (p + 1 < e && p[1] >= '0' && p[1] <= '7' && p[-1] <= '3') |
| c = (c << 3) + *(++p) - '0'; |
| } |
| *data++ = c; |
| } else if (*p == 'n') { |
| *data++ = '\n'; |
| } else if (*p == 'r') { |
| *data++ = '\r'; |
| } else if (*p == 't') { |
| *data++ = '\t'; |
| } else { // escaped |
| *data++ = *p; |
| } |
| } else { |
| *data++ = *p; |
| } |
| } |
| pattern.truncate(data - pattern.data()); |
| |
| return pattern; |
| } |
| |
| // Evaluate a magic match rule like |
| // <match value="must be converted with BinHex" type="string" offset="11"/> |
| // <match value="0x9501" type="big16" offset="0:64"/> |
| |
| QMimeMagicRule::QMimeMagicRule(const QString &type, |
| const QByteArray &value, |
| const QString &offsets, |
| const QByteArray &mask, |
| QString *errorString) |
| : m_type(QMimeMagicRule::type(type.toLatin1())), |
| m_value(value), |
| m_mask(mask), |
| m_matchFunction(nullptr) |
| { |
| if (Q_UNLIKELY(m_type == Invalid)) |
| *errorString = QLatin1String("Type ") + type + QLatin1String(" is not supported"); |
| |
| // Parse for offset as "1" or "1:10" |
| const int colonIndex = offsets.indexOf(QLatin1Char(':')); |
| const QStringRef startPosStr = offsets.midRef(0, colonIndex); // \ These decay to returning 'offsets' |
| const QStringRef endPosStr = offsets.midRef(colonIndex + 1);// / unchanged when colonIndex == -1 |
| if (Q_UNLIKELY(!QMimeTypeParserBase::parseNumber(startPosStr, &m_startPos, errorString)) || |
| Q_UNLIKELY(!QMimeTypeParserBase::parseNumber(endPosStr, &m_endPos, errorString))) { |
| m_type = Invalid; |
| return; |
| } |
| |
| if (Q_UNLIKELY(m_value.isEmpty())) { |
| m_type = Invalid; |
| if (errorString) |
| *errorString = QStringLiteral("Invalid empty magic rule value"); |
| return; |
| } |
| |
| if (m_type >= Host16 && m_type <= Byte) { |
| bool ok; |
| m_number = m_value.toUInt(&ok, 0); // autodetect base |
| if (Q_UNLIKELY(!ok)) { |
| m_type = Invalid; |
| if (errorString) |
| *errorString = QLatin1String("Invalid magic rule value \"") + QLatin1String(m_value) + QLatin1Char('"'); |
| return; |
| } |
| m_numberMask = !m_mask.isEmpty() ? m_mask.toUInt(&ok, 0) : 0; // autodetect base |
| } |
| |
| switch (m_type) { |
| case String: |
| m_pattern = makePattern(m_value); |
| m_pattern.squeeze(); |
| if (!m_mask.isEmpty()) { |
| if (Q_UNLIKELY(m_mask.size() < 4 || !m_mask.startsWith("0x"))) { |
| m_type = Invalid; |
| if (errorString) |
| *errorString = QLatin1String("Invalid magic rule mask \"") + QLatin1String(m_mask) + QLatin1Char('"'); |
| return; |
| } |
| const QByteArray &tempMask = QByteArray::fromHex(QByteArray::fromRawData( |
| m_mask.constData() + 2, m_mask.size() - 2)); |
| if (Q_UNLIKELY(tempMask.size() != m_pattern.size())) { |
| m_type = Invalid; |
| if (errorString) |
| *errorString = QLatin1String("Invalid magic rule mask size \"") + QLatin1String(m_mask) + QLatin1Char('"'); |
| return; |
| } |
| m_mask = tempMask; |
| } else { |
| m_mask.fill(char(-1), m_pattern.size()); |
| } |
| m_mask.squeeze(); |
| m_matchFunction = &QMimeMagicRule::matchString; |
| break; |
| case Byte: |
| if (m_number <= quint8(-1)) { |
| if (m_numberMask == 0) |
| m_numberMask = quint8(-1); |
| m_matchFunction = &QMimeMagicRule::matchNumber<quint8>; |
| } |
| break; |
| case Big16: |
| case Little16: |
| if (m_number <= quint16(-1)) { |
| m_number = m_type == Little16 ? qFromLittleEndian<quint16>(m_number) : qFromBigEndian<quint16>(m_number); |
| if (m_numberMask != 0) |
| m_numberMask = m_type == Little16 ? qFromLittleEndian<quint16>(m_numberMask) : qFromBigEndian<quint16>(m_numberMask); |
| } |
| Q_FALLTHROUGH(); |
| case Host16: |
| if (m_number <= quint16(-1)) { |
| if (m_numberMask == 0) |
| m_numberMask = quint16(-1); |
| m_matchFunction = &QMimeMagicRule::matchNumber<quint16>; |
| } |
| break; |
| case Big32: |
| case Little32: |
| m_number = m_type == Little32 ? qFromLittleEndian<quint32>(m_number) : qFromBigEndian<quint32>(m_number); |
| if (m_numberMask != 0) |
| m_numberMask = m_type == Little32 ? qFromLittleEndian<quint32>(m_numberMask) : qFromBigEndian<quint32>(m_numberMask); |
| Q_FALLTHROUGH(); |
| case Host32: |
| if (m_numberMask == 0) |
| m_numberMask = quint32(-1); |
| m_matchFunction = &QMimeMagicRule::matchNumber<quint32>; |
| break; |
| default: |
| break; |
| } |
| } |
| |
| QByteArray QMimeMagicRule::mask() const |
| { |
| QByteArray result = m_mask; |
| if (m_type == String) { |
| // restore '0x' |
| result = "0x" + result.toHex(); |
| } |
| return result; |
| } |
| |
| bool QMimeMagicRule::matches(const QByteArray &data) const |
| { |
| const bool ok = m_matchFunction && (this->*m_matchFunction)(data); |
| if (!ok) |
| return false; |
| |
| // No submatch? Then we are done. |
| if (m_subMatches.isEmpty()) |
| return true; |
| |
| //qDebug() << "Checking" << m_subMatches.count() << "sub-rules"; |
| // Check that one of the submatches matches too |
| for ( QList<QMimeMagicRule>::const_iterator it = m_subMatches.begin(), end = m_subMatches.end() ; |
| it != end ; ++it ) { |
| if ((*it).matches(data)) { |
| // One of the hierarchies matched -> mimetype recognized. |
| return true; |
| } |
| } |
| return false; |
| |
| |
| } |
| |
| QT_END_NAMESPACE |
