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Diffstat (limited to 'svl/source/misc/msodocumentlockfile.cxx')
| -rw-r--r-- | svl/source/misc/msodocumentlockfile.cxx | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/svl/source/misc/msodocumentlockfile.cxx b/svl/source/misc/msodocumentlockfile.cxx new file mode 100644 index 000000000..ce1bf287a --- /dev/null +++ b/svl/source/misc/msodocumentlockfile.cxx @@ -0,0 +1,273 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + */ + +#include <svl/msodocumentlockfile.hxx> +#include <algorithm> +#include <ucbhelper/content.hxx> +#include <comphelper/processfactory.hxx> +#include <o3tl/string_view.hxx> + +#include <com/sun/star/io/IOException.hpp> +#include <com/sun/star/io/XOutputStream.hpp> +#include <com/sun/star/io/XInputStream.hpp> +#include <com/sun/star/ucb/XCommandEnvironment.hpp> + +namespace svt +{ +namespace +{ +bool isWordFormat(std::u16string_view sExt) +{ + return o3tl::equalsIgnoreAsciiCase(sExt, u"DOC") || o3tl::equalsIgnoreAsciiCase(sExt, u"DOCX") + || o3tl::equalsIgnoreAsciiCase(sExt, u"RTF") + || o3tl::equalsIgnoreAsciiCase(sExt, u"ODT"); +} + +bool isExcelFormat(std::u16string_view sExt) +{ + return //sExt.equalsIgnoreAsciiCase("XLS") || // MSO does not create lockfile for XLS + o3tl::equalsIgnoreAsciiCase(sExt, u"XLSX") || o3tl::equalsIgnoreAsciiCase(sExt, u"ODS"); +} + +bool isPowerPointFormat(std::u16string_view sExt) +{ + return o3tl::equalsIgnoreAsciiCase(sExt, u"PPTX") || o3tl::equalsIgnoreAsciiCase(sExt, u"PPT") + || o3tl::equalsIgnoreAsciiCase(sExt, u"ODP"); +} + +// Need to generate different lock file name for MSO. +OUString GenerateMSOLockFileURL(std::u16string_view aOrigURL) +{ + INetURLObject aURL = LockFileCommon::ResolveLinks(INetURLObject(aOrigURL)); + + // For text documents MSO Word cuts some of the first characters of the file name + OUString sFileName = aURL.GetLastName(); + const OUString sExt = aURL.GetFileExtension(); + + if (isWordFormat(sExt)) + { + const sal_Int32 nFileNameLength = sFileName.getLength() - sExt.getLength() - 1; + if (nFileNameLength >= 8) + sFileName = sFileName.copy(2); + else if (nFileNameLength == 7) + sFileName = sFileName.copy(1); + } + aURL.setName(OUStringConcatenation("~$" + sFileName)); + return aURL.GetMainURL(INetURLObject::DecodeMechanism::NONE); +} +} + +// static +MSODocumentLockFile::AppType MSODocumentLockFile::getAppType(std::u16string_view sOrigURL) +{ + AppType eResult = AppType::PowerPoint; + INetURLObject aDocURL = LockFileCommon::ResolveLinks(INetURLObject(sOrigURL)); + const OUString sExt = aDocURL.GetFileExtension(); + if (isWordFormat(sExt)) + eResult = AppType::Word; + else if (isExcelFormat(sExt)) + eResult = AppType::Excel; + + return eResult; +} + +MSODocumentLockFile::MSODocumentLockFile(std::u16string_view aOrigURL) + : GenDocumentLockFile(GenerateMSOLockFileURL(aOrigURL)) + , m_eAppType(getAppType(aOrigURL)) +{ +} + +MSODocumentLockFile::~MSODocumentLockFile() {} + +void MSODocumentLockFile::WriteEntryToStream( + const LockFileEntry& aEntry, const css::uno::Reference<css::io::XOutputStream>& xOutput) +{ + ::osl::MutexGuard aGuard(m_aMutex); + + // Reallocate the date with the right size, different lock file size for different components + int nLockFileSize = m_eAppType == AppType::Word ? MSO_WORD_LOCKFILE_SIZE + : MSO_EXCEL_AND_POWERPOINT_LOCKFILE_SIZE; + css::uno::Sequence<sal_Int8> aData(nLockFileSize); + auto pData = aData.getArray(); + + // Write out the user name's length as a single byte integer + // The maximum length is 52 in MSO, so we'll need to truncate the user name if it's longer + OUString aUserName = aEntry[LockFileComponent::OOOUSERNAME]; + int nIndex = 0; + pData[nIndex] = static_cast<sal_Int8>( + std::min(aUserName.getLength(), sal_Int32(MSO_USERNAME_MAX_LENGTH))); + + if (aUserName.getLength() > MSO_USERNAME_MAX_LENGTH) + aUserName = aUserName.copy(0, MSO_USERNAME_MAX_LENGTH); + + // From the second position write out the user name using one byte characters. + nIndex = 1; + for (int nChar = 0; nChar < aUserName.getLength(); ++nChar) + { + pData[nIndex] = static_cast<sal_Int8>(aUserName[nChar]); + ++nIndex; + } + + // Fill up the remaining bytes with dummy data + switch (m_eAppType) + { + case AppType::Word: + while (nIndex < MSO_USERNAME_MAX_LENGTH + 2) + { + pData[nIndex] = static_cast<sal_Int8>(0); + ++nIndex; + } + break; + case AppType::PowerPoint: + pData[nIndex] = static_cast<sal_Int8>(0); + ++nIndex; + [[fallthrough]]; + case AppType::Excel: + while (nIndex < MSO_USERNAME_MAX_LENGTH + 3) + { + pData[nIndex] = static_cast<sal_Int8>(0x20); + ++nIndex; + } + break; + } + + // At the next position we have the user name's length again, but now as a 2 byte integer + pData[nIndex] = static_cast<sal_Int8>( + std::min(aUserName.getLength(), sal_Int32(MSO_USERNAME_MAX_LENGTH))); + ++nIndex; + pData[nIndex] = 0; + ++nIndex; + + // And the user name again with unicode characters + for (int nChar = 0; nChar < aUserName.getLength(); ++nChar) + { + pData[nIndex] = static_cast<sal_Int8>(aUserName[nChar] & 0xff); + ++nIndex; + pData[nIndex] = static_cast<sal_Int8>(aUserName[nChar] >> 8); + ++nIndex; + } + + // Fill the remaining part with dummy bits + switch (m_eAppType) + { + case AppType::Word: + while (nIndex < nLockFileSize) + { + pData[nIndex] = static_cast<sal_Int8>(0); + ++nIndex; + } + break; + case AppType::Excel: + case AppType::PowerPoint: + while (nIndex < nLockFileSize) + { + pData[nIndex] = static_cast<sal_Int8>(0x20); + ++nIndex; + if (nIndex < nLockFileSize) + { + pData[nIndex] = static_cast<sal_Int8>(0); + ++nIndex; + } + } + break; + } + + xOutput->writeBytes(aData); +} + +css::uno::Reference<css::io::XInputStream> MSODocumentLockFile::OpenStream() +{ + ::osl::MutexGuard aGuard(m_aMutex); + + css::uno::Reference<css::ucb::XCommandEnvironment> xEnv; + ::ucbhelper::Content aSourceContent(GetURL(), xEnv, comphelper::getProcessComponentContext()); + + // the file can be opened readonly, no locking will be done + return aSourceContent.openStreamNoLock(); +} + +LockFileEntry MSODocumentLockFile::GetLockData() +{ + ::osl::MutexGuard aGuard(m_aMutex); + + LockFileEntry aResult; + css::uno::Reference<css::io::XInputStream> xInput = OpenStream(); + if (!xInput.is()) + throw css::uno::RuntimeException(); + + const sal_Int32 nBufLen = 256; + css::uno::Sequence<sal_Int8> aBuf(nBufLen); + const sal_Int32 nRead = xInput->readBytes(aBuf, nBufLen); + xInput->closeInput(); + if (nRead >= 162) + { + // Reverse engineering of MS Office Owner Files format (MS Office 2016 tested). + // It starts with a single byte with name length, after which characters of username go + // in current Windows 8-bit codepage. + // For Word lockfiles, the name is followed by zero bytes up to position 54. + // For PowerPoint lockfiles, the name is followed by a single zero byte, and then 0x20 + // bytes up to position 55. + // For Excel lockfiles, the name is followed by 0x20 bytes up to position 55. + // At those positions in each type of lockfile, a name length 2-byte word goes, followed + // by UTF-16-LE-encoded copy of username. Spaces or some garbage follow up to the end of + // the lockfile (total 162 bytes for Word, 165 bytes for Excel/PowerPoint). + // Apparently MS Office does not allow username to be longer than 52 characters (trying + // to enter more in its options dialog results in error messages stating this limit). + const int nACPLen = aBuf[0]; + if (nACPLen > 0 && nACPLen <= 52) // skip wrong format + { + const sal_Int8* pBuf = aBuf.getConstArray() + 54; + int nUTF16Len = *pBuf; // try Word position + // If UTF-16 length is 0x20, then ACP length is also less than maximal, which means + // that in Word lockfile case, at least two preceding bytes would be zero. Both + // Excel and PowerPoint lockfiles would have at least one of those bytes non-zero. + if (nUTF16Len == 0x20 && (*(pBuf - 1) != 0 || *(pBuf - 2) != 0)) + nUTF16Len = *++pBuf; // use Excel/PowerPoint position + + if (nUTF16Len > 0 && nUTF16Len <= 52) // skip wrong format + { + OUStringBuffer str(nUTF16Len); + sal_uInt8 const* p = reinterpret_cast<sal_uInt8 const*>(pBuf + 2); + for (int i = 0; i != nUTF16Len; ++i) + { + str.append(sal_Unicode(p[0] | (sal_uInt32(p[1]) << 8))); + p += 2; + } + aResult[LockFileComponent::OOOUSERNAME] = str.makeStringAndClear(); + } + } + } + return aResult; +} + +void MSODocumentLockFile::RemoveFile() +{ + ::osl::MutexGuard aGuard(m_aMutex); + + // TODO/LATER: the removing is not atomic, is it possible in general to make it atomic? + LockFileEntry aNewEntry = GenerateOwnEntry(); + LockFileEntry aFileData = GetLockData(); + + if (aFileData[LockFileComponent::OOOUSERNAME] != aNewEntry[LockFileComponent::OOOUSERNAME]) + throw css::io::IOException(); // not the owner, access denied + + RemoveFileDirectly(); +} + +bool MSODocumentLockFile::IsMSOSupportedFileFormat(std::u16string_view aURL) +{ + INetURLObject aDocURL = LockFileCommon::ResolveLinks(INetURLObject(aURL)); + const OUString sExt = aDocURL.GetFileExtension(); + + return isWordFormat(sExt) || isExcelFormat(sExt) || isPowerPointFormat(sExt); +} + +} // namespace svt + +/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */ |