/*++ Copyright (c) 2000 Microsoft Corporation Module Name: EmulateCDFS.cpp Abstract: Removes read only attributes from CD directories: just like Win9x. This shim has gone through several revisions. Originally it was thought that win9x simply ignored the ReadOnly, DesiredAccess and ShareMode parameters, but after some testing, it turns out that this is only true for the CDRom drive. Unfortunately we have to check every file to see if it's on the CD first, just in case someone opens with exclusive access and then tries to open again. Notes: This is a general purpose shim. History: 01/03/2000 a-jamd Created 12/02/2000 linstev Separated into 2 shims: RemoveReadOnlyAttribute and this one Added CreateFile hooks 02/14/2002 mnikkel Changed InitializeCriticalSection to InitializeCriticalSectionAndSpinCount --*/ #include "precomp.h" #include "CharVector.h" IMPLEMENT_SHIM_BEGIN(EmulateCDFS) #include "ShimHookMacro.h" APIHOOK_ENUM_BEGIN APIHOOK_ENUM_ENTRY(OpenFile) APIHOOK_ENUM_ENTRY(CreateFileA) APIHOOK_ENUM_ENTRY(CreateFileW) APIHOOK_ENUM_ENTRY(CreateFileMappingA) APIHOOK_ENUM_ENTRY(MapViewOfFile) APIHOOK_ENUM_ENTRY(MapViewOfFileEx) APIHOOK_ENUM_ENTRY(DuplicateHandle) APIHOOK_ENUM_ENTRY(CloseHandle) APIHOOK_ENUM_ENTRY(GetFileAttributesW) APIHOOK_ENUM_ENTRY(GetFileAttributesA) APIHOOK_ENUM_ENTRY(FindFirstFileW) APIHOOK_ENUM_ENTRY(FindFirstFileA) APIHOOK_ENUM_ENTRY(FindNextFileW) APIHOOK_ENUM_ENTRY(FindNextFileA) APIHOOK_ENUM_ENTRY(GetFileInformationByHandle) APIHOOK_ENUM_ENTRY(GetDiskFreeSpaceA) APIHOOK_ENUM_END typedef struct _FINDFILE_HANDLE { HANDLE DirectoryHandle; PVOID FindBufferBase; PVOID FindBufferNext; ULONG FindBufferLength; ULONG FindBufferValidLength; RTL_CRITICAL_SECTION FindBufferLock; } FINDFILE_HANDLE, *PFINDFILE_HANDLE; class RO_FileMappingList { private: static VectorT * g_phROHandles; // File mapping handles that we have forced to Read only static RO_FileMappingList * g_RO_Handles; static CRITICAL_SECTION critSec; inline int GetIndex(HANDLE handle) const; RO_FileMappingList(); ~RO_FileMappingList(); public: static void Add(HANDLE roHandle); static void Remove(HANDLE roHandle); static BOOL Exist(HANDLE handle); static BOOL Initialize(); }; // A global list of file mapping handles that we have forced to readonly RO_FileMappingList * RO_FileMappingList::g_RO_Handles = NULL; VectorT * RO_FileMappingList::g_phROHandles = NULL; // File mapping handles that we have forced to Read only CRITICAL_SECTION RO_FileMappingList::critSec; RO_FileMappingList::RO_FileMappingList() { } RO_FileMappingList::~RO_FileMappingList() { DeleteCriticalSection(&critSec); } void RO_FileMappingList::Add(HANDLE roHandle) { if (roHandle != NULL) { EnterCriticalSection(&critSec); int index = g_RO_Handles->GetIndex(roHandle); if (index == -1) // not found { DPFN(eDbgLevelSpew, "[RO_FileMappingList::Add] Handle 0x%08x", roHandle); g_phROHandles->Append(roHandle); } LeaveCriticalSection(&critSec); } } void RO_FileMappingList::Remove(HANDLE roHandle) { if (roHandle != NULL) { EnterCriticalSection(&critSec); int index = g_RO_Handles->GetIndex(roHandle); if (index >= 0) // found it { DPFN(eDbgLevelSpew, "[RO_FileMappingList::Remove] Handle 0x%08x", roHandle); g_phROHandles->Remove(index); } LeaveCriticalSection(&critSec); } } inline int RO_FileMappingList::GetIndex(HANDLE handle) const { int index = g_phROHandles->Find(handle); return index; } BOOL RO_FileMappingList::Exist(HANDLE handle) { EnterCriticalSection(&critSec); BOOL bExist = g_RO_Handles->GetIndex(handle) >= 0; LeaveCriticalSection(&critSec); return bExist; } BOOL RO_FileMappingList::Initialize() { g_RO_Handles = new RO_FileMappingList; g_phROHandles = new VectorT; if (g_RO_Handles && g_phROHandles) { return InitializeCriticalSectionAndSpinCount(&(g_RO_Handles->critSec),0x80000000); } return FALSE; } /*++ Remove write attributes for read-only devices. --*/ HFILE APIHOOK(OpenFile)( LPCSTR lpFileName, // file name LPOFSTRUCT lpReOpenBuff, // file information UINT uStyle // action and attributes ) { if ((uStyle & OF_READWRITE) && IsOnCDRomA(lpFileName)) { // Remove the Read/Write bits uStyle &= ~OF_READWRITE; uStyle |= OF_READ; LOGN(eDbgLevelInfo, "[OpenFile] \"%s\": attributes modified for read-only device", lpFileName); } HFILE returnValue = ORIGINAL_API(OpenFile)(lpFileName, lpReOpenBuff, uStyle); return returnValue; } /*++ Remove write attributes for read-only devices. --*/ HANDLE APIHOOK(CreateFileA)( LPSTR lpFileName, DWORD dwDesiredAccess, DWORD dwShareMode, LPSECURITY_ATTRIBUTES lpSecurityAttributes, DWORD dwCreationDisposition, DWORD dwFlagsAndAttributes, HANDLE hTemplateFile ) { if (((dwCreationDisposition == OPEN_EXISTING) || (dwCreationDisposition == OPEN_ALWAYS)) && ((dwDesiredAccess & GENERIC_WRITE) || (dwShareMode != FILE_SHARE_READ)) && IsOnCDRomA(lpFileName)) { dwDesiredAccess &= ~GENERIC_WRITE; dwShareMode = FILE_SHARE_READ; LOGN(eDbgLevelInfo, "[CreateFileA] \"%s\": attributes modified for read-only device", lpFileName); } if (dwFlagsAndAttributes & FILE_FLAG_NO_BUFFERING) { dwFlagsAndAttributes &= ~FILE_FLAG_NO_BUFFERING; LOGN(eDbgLevelInfo, "[CreateFileA] \"%s\": removed NO_BUFFERING flag", lpFileName); } HANDLE hRet = ORIGINAL_API(CreateFileA)( lpFileName, dwDesiredAccess, dwShareMode, lpSecurityAttributes, dwCreationDisposition, dwFlagsAndAttributes, hTemplateFile); DPFN(eDbgLevelSpew, "[CreateFileA] -File: \"%s\" -GENERIC_WRITE:%c -FILE_SHARE_WRITE:%c%s", lpFileName, (dwDesiredAccess & GENERIC_WRITE) ? 'Y' : 'N', (dwShareMode & FILE_SHARE_WRITE) ? 'Y' : 'N', (hRet == INVALID_HANDLE_VALUE) ? "\n\t***********Failed***********" : ""); return hRet; } /*++ Remove write attributes for read-only devices. --*/ HANDLE APIHOOK(CreateFileW)( LPWSTR lpFileName, DWORD dwDesiredAccess, DWORD dwShareMode, LPSECURITY_ATTRIBUTES lpSecurityAttributes, DWORD dwCreationDisposition, DWORD dwFlagsAndAttributes, HANDLE hTemplateFile ) { if (((dwCreationDisposition == OPEN_EXISTING) || (dwCreationDisposition == OPEN_ALWAYS)) && ((dwDesiredAccess & GENERIC_WRITE) || (dwShareMode != FILE_SHARE_READ)) && IsOnCDRomW(lpFileName)) { dwDesiredAccess &= ~GENERIC_WRITE; dwShareMode = FILE_SHARE_READ; LOGN(eDbgLevelError, "[CreateFileW] \"%S\": attributes modified for read-only device", lpFileName); } if (dwFlagsAndAttributes & FILE_FLAG_NO_BUFFERING) { dwFlagsAndAttributes &= ~FILE_FLAG_NO_BUFFERING; LOGN(eDbgLevelInfo, "[CreateFileW] \"%S\": removed NO_BUFFERING flag", lpFileName); } HANDLE hRet = ORIGINAL_API(CreateFileW)( lpFileName, dwDesiredAccess, dwShareMode, lpSecurityAttributes, dwCreationDisposition, dwFlagsAndAttributes, hTemplateFile); DPFN(eDbgLevelSpew, "[CreateFileW] -File: \"%S\" -GENERIC_WRITE:%c -FILE_SHARE_WRITE:%c%s", lpFileName, (dwDesiredAccess & GENERIC_WRITE) ? 'Y' : 'N', (dwShareMode & FILE_SHARE_WRITE) ? 'Y' : 'N', (hRet == INVALID_HANDLE_VALUE) ? "\n\t***********Failed***********" : ""); return hRet; } HANDLE APIHOOK(CreateFileMappingA)( HANDLE hFile, // handle to file LPSECURITY_ATTRIBUTES lpAttributes, // security DWORD flProtect, // protection DWORD dwMaximumSizeHigh, // high-order DWORD of size DWORD dwMaximumSizeLow, // low-order DWORD of size LPCSTR lpName // object name ) { BOOL bChangedProtect = FALSE; if (!(flProtect & PAGE_READONLY) && IsOnCDRom(hFile)) { // This handle is on a CD-ROM, force the protection to READONLY flProtect = PAGE_READONLY; bChangedProtect = TRUE; LOGN(eDbgLevelError, "[CreateFileMappingA] Handle 0x%08x: attributes modified for read-only device", hFile); } HANDLE hRet = ORIGINAL_API(CreateFileMappingA)( hFile, lpAttributes, flProtect, dwMaximumSizeHigh, dwMaximumSizeLow, lpName); // If the handle is on a CD-ROM, rember it if (bChangedProtect) { RO_FileMappingList::Add(hRet); } DPFN(eDbgLevelSpew, "[CreateFileMappingA] Handle 0x%08x -PAGE_READWRITE:%c -PAGE_WRITECOPY:%c%s", lpName, (flProtect & PAGE_READWRITE) ? 'Y' : 'N', (flProtect & PAGE_WRITECOPY) ? 'Y' : 'N', (hRet == INVALID_HANDLE_VALUE) ? "\n\t***********Failed***********" : ""); return hRet; } LPVOID APIHOOK(MapViewOfFile)( HANDLE hFileMappingObject, // handle to file-mapping object DWORD dwDesiredAccess, // access mode DWORD dwFileOffsetHigh, // high-order DWORD of offset DWORD dwFileOffsetLow, // low-order DWORD of offset SIZE_T dwNumberOfBytesToMap // number of bytes to map ) { // // Check to see if we need to force Read access for CD-ROM files // Only the FILE_MAP_READ bit may be enabled for CD-ROM access // if ((dwDesiredAccess != FILE_MAP_READ) && RO_FileMappingList::Exist(hFileMappingObject)) { dwDesiredAccess = FILE_MAP_READ; LOGN(eDbgLevelError, "[MapViewOfFile] Handle 0x%08x: attributes modified for read-only device", hFileMappingObject); } HANDLE hRet = ORIGINAL_API(MapViewOfFile)( hFileMappingObject, dwDesiredAccess, dwFileOffsetHigh, dwFileOffsetLow, dwNumberOfBytesToMap); return hRet; } LPVOID APIHOOK(MapViewOfFileEx)( HANDLE hFileMappingObject, // handle to file-mapping object DWORD dwDesiredAccess, // access mode DWORD dwFileOffsetHigh, // high-order DWORD of offset DWORD dwFileOffsetLow, // low-order DWORD of offset SIZE_T dwNumberOfBytesToMap, // number of bytes to map LPVOID lpBaseAddress // starting addres ) { // // Check to see if we need to force Read access for CD-ROM files // Only the FILE_MAP_READ bit may be enabled for CD-ROM access // if ((dwDesiredAccess != FILE_MAP_READ) && RO_FileMappingList::Exist(hFileMappingObject)) { dwDesiredAccess = FILE_MAP_READ; LOGN(eDbgLevelError, "[MapViewOfFile] Handle 0x%08x: attributes modified for read-only device", hFileMappingObject); } HANDLE hRet = ORIGINAL_API(MapViewOfFileEx)( hFileMappingObject, dwDesiredAccess, dwFileOffsetHigh, dwFileOffsetLow, dwNumberOfBytesToMap, lpBaseAddress); return hRet; } /*++ If hSourceHandle has been mucked with, add the duplicated handle to our list --*/ BOOL APIHOOK(DuplicateHandle)( HANDLE hSourceProcessHandle, // handle to source process HANDLE hSourceHandle, // handle to duplicate HANDLE hTargetProcessHandle, // handle to target process LPHANDLE lpTargetHandle, // duplicate handle DWORD dwDesiredAccess, // requested access BOOL bInheritHandle, // handle inheritance option DWORD dwOptions // optional actions ) { BOOL retval = ORIGINAL_API(DuplicateHandle)( hSourceProcessHandle, hSourceHandle, hTargetProcessHandle, lpTargetHandle, dwDesiredAccess, bInheritHandle, dwOptions); if (retval && RO_FileMappingList::Exist(hSourceHandle)) { RO_FileMappingList::Add(hTargetProcessHandle); } return retval; } /*++ If hObject has been mucked with, remove it from the list. --*/ BOOL APIHOOK(CloseHandle)( HANDLE hObject // handle to object ) { RO_FileMappingList::Remove(hObject); return ORIGINAL_API(CloseHandle)(hObject); } /*++ Remove read only attribute if it's a directory --*/ DWORD APIHOOK(GetFileAttributesA)(LPCSTR lpFileName) { DWORD dwFileAttributes = ORIGINAL_API(GetFileAttributesA)(lpFileName); // Check for READONLY and DIRECTORY attributes if ((dwFileAttributes != INT_PTR(-1)) && (dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) && (dwFileAttributes & FILE_ATTRIBUTE_READONLY) && IsOnCDRomA(lpFileName)) { // Flip the read-only bit. LOGN(eDbgLevelWarning, "[GetFileAttributesA] Removing FILE_ATTRIBUTE_READONLY"); dwFileAttributes ^= FILE_ATTRIBUTE_READONLY; } return dwFileAttributes; } /*++ Remove read only attribute if it's a directory --*/ DWORD APIHOOK(GetFileAttributesW)(LPCWSTR wcsFileName) { DWORD dwFileAttributes = ORIGINAL_API(GetFileAttributesW)(wcsFileName); // Check for READONLY and DIRECTORY attributes if ((dwFileAttributes != INT_PTR(-1)) && (dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) && (dwFileAttributes & FILE_ATTRIBUTE_READONLY) && IsOnCDRomW(wcsFileName)) { // Flip the read-only bit. LOGN(eDbgLevelWarning, "[GetFileAttributesW] Removing FILE_ATTRIBUTE_READONLY"); dwFileAttributes ^= FILE_ATTRIBUTE_READONLY; } return dwFileAttributes; } /*++ Remove read only attribute if it's a directory --*/ HANDLE APIHOOK(FindFirstFileA)( LPCSTR lpFileName, LPWIN32_FIND_DATAA lpFindFileData ) { HANDLE hFindFile = ORIGINAL_API(FindFirstFileA)(lpFileName, lpFindFileData); if ((hFindFile != INVALID_HANDLE_VALUE) && (lpFindFileData->dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) && (lpFindFileData->dwFileAttributes & FILE_ATTRIBUTE_READONLY) && IsOnCDRom(((PFINDFILE_HANDLE) hFindFile)->DirectoryHandle)) { // Flip the read-only bit LOGN(eDbgLevelWarning, "[FindFirstFileA] Removing FILE_ATTRIBUTE_READONLY"); lpFindFileData->dwFileAttributes ^= FILE_ATTRIBUTE_READONLY; } return hFindFile; } /*++ Remove read only attribute if it's a directory. --*/ HANDLE APIHOOK(FindFirstFileW)( LPCWSTR wcsFileName, LPWIN32_FIND_DATAW lpFindFileData ) { HANDLE hFindFile = ORIGINAL_API(FindFirstFileW)(wcsFileName, lpFindFileData); if ((hFindFile != INVALID_HANDLE_VALUE) && (lpFindFileData->dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) && (lpFindFileData->dwFileAttributes & FILE_ATTRIBUTE_READONLY) && IsOnCDRom(((PFINDFILE_HANDLE) hFindFile)->DirectoryHandle)) { // It's a directory: flip the read-only bit LOGN(eDbgLevelInfo, "[FindFirstFileW] Removing FILE_ATTRIBUTE_READONLY"); lpFindFileData->dwFileAttributes ^= FILE_ATTRIBUTE_READONLY; } return hFindFile; } /*++ Remove read only attribute if it's a directory. --*/ BOOL APIHOOK(FindNextFileA)( HANDLE hFindFile, LPWIN32_FIND_DATAA lpFindFileData ) { BOOL bRet = ORIGINAL_API(FindNextFileA)(hFindFile, lpFindFileData); if (bRet && (lpFindFileData->dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) && (lpFindFileData->dwFileAttributes & FILE_ATTRIBUTE_READONLY) && IsOnCDRom(((PFINDFILE_HANDLE) hFindFile)->DirectoryHandle)) { // Flip the read-only bit. LOGN(eDbgLevelWarning, "[FindNextFileA] Removing FILE_ATTRIBUTE_READONLY"); lpFindFileData->dwFileAttributes ^= FILE_ATTRIBUTE_READONLY; } return bRet; } /*++ Remove read only attribute if it's a directory. --*/ BOOL APIHOOK(FindNextFileW)( HANDLE hFindFile, LPWIN32_FIND_DATAW lpFindFileData ) { BOOL bRet = ORIGINAL_API(FindNextFileW)(hFindFile, lpFindFileData); if (bRet && (lpFindFileData->dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) && (lpFindFileData->dwFileAttributes & FILE_ATTRIBUTE_READONLY) && IsOnCDRom(((PFINDFILE_HANDLE) hFindFile)->DirectoryHandle)) { // Flip the read-only bit LOGN(eDbgLevelWarning, "[FindNextFileW] Removing FILE_ATTRIBUTE_READONLY"); lpFindFileData->dwFileAttributes ^= FILE_ATTRIBUTE_READONLY; } return bRet; } /*++ Remove read only attribute if it's a directory. --*/ BOOL APIHOOK(GetFileInformationByHandle)( HANDLE hFile, LPBY_HANDLE_FILE_INFORMATION lpFileInformation ) { BOOL bRet = ORIGINAL_API(GetFileInformationByHandle)(hFile, lpFileInformation); if (bRet && (lpFileInformation->dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) && (lpFileInformation->dwFileAttributes & FILE_ATTRIBUTE_READONLY) && IsOnCDRom(hFile)) { // It's a CDROM: flip the read-only bit. LOGN(eDbgLevelWarning, "[GetFileInformationByHandle] Removing FILE_ATTRIBUTE_READONLY"); lpFileInformation->dwFileAttributes ^= FILE_ATTRIBUTE_READONLY; } return bRet; } /*++ If the disk is a CDROM, return the same wrong numbers as Win9x --*/ BOOL APIHOOK(GetDiskFreeSpaceA)( LPCSTR lpRootPathName, LPDWORD lpSectorsPerCluster, LPDWORD lpBytesPerSector, LPDWORD lpNumberOfFreeClusters, LPDWORD lpTotalNumberOfClusters ) { if (IsOnCDRomA(lpRootPathName)) { // Hard code values to match Win9x (wrong) description of CDROM *lpSectorsPerCluster = 0x10; *lpBytesPerSector = 0x800; *lpNumberOfFreeClusters = 0; *lpTotalNumberOfClusters = 0x2b7; return TRUE; } else { // Call the original API BOOL lRet = ORIGINAL_API(GetDiskFreeSpaceA)( lpRootPathName, lpSectorsPerCluster, lpBytesPerSector, lpNumberOfFreeClusters, lpTotalNumberOfClusters); return lRet; } } /*++ Initialize all the registry hooks --*/ BOOL NOTIFY_FUNCTION( DWORD fdwReason ) { if (fdwReason == DLL_PROCESS_ATTACH) { // This forces the allocation of the array: return RO_FileMappingList::Initialize(); } return TRUE; } /*++ Register hooked functions --*/ HOOK_BEGIN CALL_NOTIFY_FUNCTION APIHOOK_ENTRY(KERNEL32.DLL, OpenFile) APIHOOK_ENTRY(KERNEL32.DLL, CreateFileA) APIHOOK_ENTRY(KERNEL32.DLL, CreateFileW) APIHOOK_ENTRY(KERNEL32.DLL, CreateFileMappingA) APIHOOK_ENTRY(KERNEL32.DLL, MapViewOfFile) APIHOOK_ENTRY(KERNEL32.DLL, MapViewOfFileEx) APIHOOK_ENTRY(KERNEL32.DLL, DuplicateHandle) APIHOOK_ENTRY(KERNEL32.DLL, CloseHandle) APIHOOK_ENTRY(KERNEL32.DLL, GetFileAttributesA) APIHOOK_ENTRY(KERNEL32.DLL, GetFileAttributesW) APIHOOK_ENTRY(KERNEL32.DLL, FindFirstFileA) APIHOOK_ENTRY(KERNEL32.DLL, FindFirstFileW) APIHOOK_ENTRY(KERNEL32.DLL, FindNextFileA) APIHOOK_ENTRY(KERNEL32.DLL, FindNextFileW) APIHOOK_ENTRY(KERNEL32.DLL, GetFileInformationByHandle) APIHOOK_ENTRY(KERNEL32.DLL, GetDiskFreeSpaceA) HOOK_END IMPLEMENT_SHIM_END