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/*++
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<HANDLE> * 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<HANDLE> * 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<HANDLE>;
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
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