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Diffstat (limited to 'shared/symlink_target.h')
| -rw-r--r-- | shared/symlink_target.h | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/shared/symlink_target.h b/shared/symlink_target.h new file mode 100644 index 00000000..c68d5229 --- /dev/null +++ b/shared/symlink_target.h @@ -0,0 +1,146 @@ +// ************************************************************************** +// * This file is part of the FreeFileSync project. It is distributed under * +// * GNU General Public License: http://www.gnu.org/licenses/gpl.html * +// * Copyright (C) 2008-2010 ZenJu (zhnmju123 AT gmx.de) * +// ************************************************************************** +// +#ifndef SYMLINK_WIN_H_INCLUDED +#define SYMLINK_WIN_H_INCLUDED + +#include <boost/shared_ptr.hpp> +#include <boost/scoped_array.hpp> +#include "system_func.h" +#include <wx/intl.h> +#include "string_conv.h" +#include "file_error.h" + +#ifdef FFS_WIN +#include <wx/msw/wrapwin.h> //includes "windows.h" +#include "WinIoCtl.h" +#include "long_path_prefix.h" + +#elif defined FFS_LINUX +#include <unistd.h> +#endif + + +#ifdef _MSC_VER //I don't have Windows Driver Kit at hands right now, so unfortunately we need to redefine this structures and cross fingers... +typedef struct _REPARSE_DATA_BUFFER +{ + ULONG ReparseTag; + USHORT ReparseDataLength; + USHORT Reserved; + union + { + struct + { + USHORT SubstituteNameOffset; + USHORT SubstituteNameLength; + USHORT PrintNameOffset; + USHORT PrintNameLength; + ULONG Flags; + WCHAR PathBuffer[1]; + } SymbolicLinkReparseBuffer; + struct + { + USHORT SubstituteNameOffset; + USHORT SubstituteNameLength; + USHORT PrintNameOffset; + USHORT PrintNameLength; + WCHAR PathBuffer[1]; + } MountPointReparseBuffer; + struct + { + UCHAR DataBuffer[1]; + } GenericReparseBuffer; + }; +} REPARSE_DATA_BUFFER, *PREPARSE_DATA_BUFFER; +#define REPARSE_DATA_BUFFER_HEADER_SIZE FIELD_OFFSET(REPARSE_DATA_BUFFER, GenericReparseBuffer) +#endif + +namespace +{ + //retrieve raw target data of symlink or junction +Zstring getSymlinkRawTargetString(const Zstring& linkPath) //throw (FileError) +{ + using ffs3::zToWx; + using ffs3::FileError; +#ifdef FFS_WIN +//FSCTL_GET_REPARSE_POINT: http://msdn.microsoft.com/en-us/library/aa364571(VS.85).aspx + + const HANDLE hLink = ::CreateFile(ffs3::applyLongPathPrefix(linkPath).c_str(), + GENERIC_READ, + FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, + NULL, + OPEN_EXISTING, + FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OPEN_REPARSE_POINT, + NULL); + if (hLink == INVALID_HANDLE_VALUE) + { + wxString errorMessage = wxString(_("Error resolving symbolic link:")) + wxT("\n\"") + ffs3::zToWx(linkPath) + wxT("\""); + throw FileError(errorMessage + wxT("\n\n") + ffs3::getLastErrorFormatted()); + } + boost::shared_ptr<void> dummy(hLink, ::CloseHandle); + + //respect alignment issues... + const size_t bufferSize = REPARSE_DATA_BUFFER_HEADER_SIZE + MAXIMUM_REPARSE_DATA_BUFFER_SIZE; + boost::scoped_array<char> buffer(new char[bufferSize]); + + DWORD bytesReturned; //dummy value required by FSCTL_GET_REPARSE_POINT! + if (!::DeviceIoControl(hLink, //__in HANDLE hDevice, + FSCTL_GET_REPARSE_POINT, //__in DWORD dwIoControlCode, + NULL, //__in_opt LPVOID lpInBuffer, + 0, //__in DWORD nInBufferSize, + buffer.get(), //__out_opt LPVOID lpOutBuffer, + bufferSize, //__in DWORD nOutBufferSize, + &bytesReturned, //__out_opt LPDWORD lpBytesReturned, + NULL)) //__inout_opt LPOVERLAPPED lpOverlapped + { + wxString errorMessage = wxString(_("Error resolving symbolic link:")) + wxT("\n\"") + ffs3::zToWx(linkPath) + wxT("\""); + throw FileError(errorMessage + wxT("\n\n") + ffs3::getLastErrorFormatted()); + } + + REPARSE_DATA_BUFFER& reparseData = *reinterpret_cast<REPARSE_DATA_BUFFER*>(buffer.get()); //REPARSE_DATA_BUFFER needs to be artificially enlarged! + + Zstring output; + if (reparseData.ReparseTag == IO_REPARSE_TAG_SYMLINK) + { + output = Zstring(reparseData.SymbolicLinkReparseBuffer.PathBuffer + reparseData.SymbolicLinkReparseBuffer.SubstituteNameOffset / sizeof(WCHAR), + reparseData.SymbolicLinkReparseBuffer.SubstituteNameLength / sizeof(WCHAR)); + } + else if (reparseData.ReparseTag == IO_REPARSE_TAG_MOUNT_POINT) + { + output = Zstring(reparseData.MountPointReparseBuffer.PathBuffer + reparseData.MountPointReparseBuffer.SubstituteNameOffset / sizeof(WCHAR), + reparseData.MountPointReparseBuffer.SubstituteNameLength / sizeof(WCHAR)); + } + else + { + wxString errorMessage = wxString(_("Error resolving symbolic link:")) + wxT("\n\"") + ffs3::zToWx(linkPath) + wxT("\""); + throw FileError(errorMessage + wxT("\n\n") + wxT("Not a symbolic link or junction!")); + } + + //absolute symlinks and junctions technically start with \??\ while relative ones do not + if (output.StartsWith(Zstr("\\??\\"))) + output = Zstring(output.c_str() + 4, output.length() - 4); + + return output; + +#elif defined FFS_LINUX + const int BUFFER_SIZE = 10000; + char buffer[BUFFER_SIZE]; + + const int bytesWritten = ::readlink(linkPath.c_str(), buffer, BUFFER_SIZE); + if (bytesWritten < 0 || bytesWritten >= BUFFER_SIZE) + { + wxString errorMessage = wxString(_("Error resolving symbolic link:")) + wxT("\n\"") + zToWx(linkPath) + wxT("\""); + if (bytesWritten < 0) errorMessage += wxString(wxT("\n\n")) + ffs3::getLastErrorFormatted(); + throw FileError(errorMessage); + } + buffer[bytesWritten] = 0; //set null-terminating char + + return buffer; +#endif +} +} + +#endif // SYMLINK_WIN_H_INCLUDED |