/**
* Advances the buffer pointer.
*
* @param pThis The directory instance data.
*/
static int rtDirNtAdvanceBuffer(PRTDIR pThis)
{
int rc;
#ifdef IPRT_WITH_NT_PATH_PASSTHRU
if (pThis->enmInfoClass == FileMaximumInformation)
{
pThis->uCurData.pObjDir++;
pThis->fDataUnread = pThis->uCurData.pObjDir->Name.Length != 0;
return VINF_SUCCESS;
}
#endif
pThis->fDataUnread = false;
uint32_t const offNext = pThis->uCurData.pBoth->NextEntryOffset;
if (offNext == 0)
return VINF_SUCCESS;
#ifdef RTDIR_NT_STRICT
/* Make sure the next-record offset is beyond the current record. */
size_t cbRec;
if (pThis->enmInfoClass == FileIdBothDirectoryInformation)
cbRec = RT_UOFFSETOF(FILE_ID_BOTH_DIR_INFORMATION, FileName);
else
cbRec = RT_UOFFSETOF(FILE_BOTH_DIR_INFORMATION, FileName);
cbRec += pThis->uCurData.pBoth->FileNameLength;
AssertReturn(offNext >= cbRec, VERR_IO_GEN_FAILURE);
#endif
pThis->uCurData.u += offNext;
rc = rtDirNtCheckRecord(pThis);
pThis->fDataUnread = RT_SUCCESS(rc);
return rc;
}
/**
* Fetches more data from the file system.
*
* @returns IPRT status code
* @param pThis The directory instance data.
*/
static int rtDirNtFetchMore(PRTDIR pThis)
{
Assert(!pThis->fDataUnread);
/*
* Allocate the buffer the first time around.
* We do this in lazy fashion as some users of RTDirOpen will not actually
* list any files, just open it for various reasons.
*/
bool fFirst = false;
if (!pThis->pabBuffer)
{
fFirst = false;
pThis->cbBufferAlloc = _256K;
pThis->pabBuffer = (uint8_t *)RTMemAlloc(pThis->cbBufferAlloc);
if (!pThis->pabBuffer)
{
do
{
pThis->cbBufferAlloc /= 4;
pThis->pabBuffer = (uint8_t *)RTMemAlloc(pThis->cbBufferAlloc);
} while (pThis->pabBuffer == NULL && pThis->cbBufferAlloc > _4K);
if (!pThis->pabBuffer)
return VERR_NO_MEMORY;
}
}
/*
* Read more.
*/
NTSTATUS rcNt;
IO_STATUS_BLOCK Ios = MY_IO_STATUS_BLOCK_INITIALIZER;
if (pThis->enmInfoClass != (FILE_INFORMATION_CLASS)0)
{
#ifdef IPRT_WITH_NT_PATH_PASSTHRU
if (pThis->enmInfoClass == FileMaximumInformation)
{
Ios.Information = 0;
Ios.Status = rcNt = NtQueryDirectoryObject(pThis->hDir,
pThis->pabBuffer,
pThis->cbBufferAlloc,
RTDIR_NT_SINGLE_RECORD /*ReturnSingleEntry */,
FALSE /*RestartScan*/,
&pThis->uObjDirCtx,
(PULONG)&Ios.Information);
}
else
#endif
rcNt = NtQueryDirectoryFile(pThis->hDir,
NULL /* Event */,
NULL /* ApcRoutine */,
NULL /* ApcContext */,
&Ios,
pThis->pabBuffer,
pThis->cbBufferAlloc,
pThis->enmInfoClass,
RTDIR_NT_SINGLE_RECORD /*ReturnSingleEntry */,
pThis->pNtFilterStr,
FALSE /*RestartScan */);
}
else
{
/*
* The first time around we have figure which info class we can use.
* We prefer one which gives us file IDs, but we'll settle for less.
*/
pThis->enmInfoClass = FileIdBothDirectoryInformation;
rcNt = NtQueryDirectoryFile(pThis->hDir,
NULL /* Event */,
NULL /* ApcRoutine */,
NULL /* ApcContext */,
&Ios,
pThis->pabBuffer,
pThis->cbBufferAlloc,
pThis->enmInfoClass,
RTDIR_NT_SINGLE_RECORD /*ReturnSingleEntry */,
pThis->pNtFilterStr,
FALSE /*RestartScan */);
if (!NT_SUCCESS(rcNt))
{
pThis->enmInfoClass = FileBothDirectoryInformation;
rcNt = NtQueryDirectoryFile(pThis->hDir,
NULL /* Event */,
NULL /* ApcRoutine */,
NULL /* ApcContext */,
&Ios,
pThis->pabBuffer,
pThis->cbBufferAlloc,
pThis->enmInfoClass,
RTDIR_NT_SINGLE_RECORD /*ReturnSingleEntry */,
pThis->pNtFilterStr,
FALSE /*RestartScan */);
}
}
if (!NT_SUCCESS(rcNt))
{
if (rcNt == STATUS_NO_MORE_FILES || rcNt == STATUS_NO_MORE_ENTRIES)
return VERR_NO_MORE_FILES;
return RTErrConvertFromNtStatus(rcNt);
}
Assert(Ios.Information > sizeof(*pThis->uCurData.pBoth));
/*
* Set up the data members.
*/
pThis->uCurData.u = (uintptr_t)pThis->pabBuffer;
pThis->cbBuffer = Ios.Information;
int rc = rtDirNtCheckRecord(pThis);
pThis->fDataUnread = RT_SUCCESS(rc);
return rc;
}
/**
* Fetches more data from the file system.
*
* @returns IPRT status code
* @param pThis The directory instance data.
*/
static int rtDirNtFetchMore(PRTDIRINTERNAL pThis)
{
Assert(!pThis->fDataUnread);
/*
* Allocate the buffer the first time around.
* We do this in lazy fashion as some users of RTDirOpen will not actually
* list any files, just open it for various reasons.
*
* We also reduce the buffer size for networked devices as the windows 7-8.1,
* server 2012, ++ CIFS servers or/and IFSes screws up buffers larger than 64KB.
* There is an alternative hack below, btw. We'll leave both in for now.
*/
bool fFirst = false;
if (!pThis->pabBuffer)
{
pThis->cbBufferAlloc = _256K;
if (true) /** @todo skip for known local devices, like the boot device? */
{
IO_STATUS_BLOCK Ios2 = RTNT_IO_STATUS_BLOCK_INITIALIZER;
FILE_FS_DEVICE_INFORMATION Info = { 0, 0 };
NTSTATUS rcNt2 = NtQueryVolumeInformationFile(pThis->hDir, &Ios2, &Info, sizeof(Info), FileFsDeviceInformation);
if ( !NT_SUCCESS(rcNt2)
|| (Info.Characteristics & FILE_REMOTE_DEVICE)
|| Info.DeviceType == FILE_DEVICE_NETWORK
|| Info.DeviceType == FILE_DEVICE_NETWORK_FILE_SYSTEM
|| Info.DeviceType == FILE_DEVICE_NETWORK_REDIRECTOR
|| Info.DeviceType == FILE_DEVICE_SMB)
pThis->cbBufferAlloc = _64K;
}
fFirst = false;
pThis->pabBuffer = (uint8_t *)RTMemAlloc(pThis->cbBufferAlloc);
if (!pThis->pabBuffer)
{
do
{
pThis->cbBufferAlloc /= 4;
pThis->pabBuffer = (uint8_t *)RTMemAlloc(pThis->cbBufferAlloc);
} while (pThis->pabBuffer == NULL && pThis->cbBufferAlloc > _4K);
if (!pThis->pabBuffer)
return VERR_NO_MEMORY;
}
/*
* Also try determining the device number.
*/
PFILE_FS_VOLUME_INFORMATION pVolInfo = (PFILE_FS_VOLUME_INFORMATION)pThis->pabBuffer;
pVolInfo->VolumeSerialNumber = 0;
IO_STATUS_BLOCK Ios = RTNT_IO_STATUS_BLOCK_INITIALIZER;
NTSTATUS rcNt = NtQueryVolumeInformationFile(pThis->hDir, &Ios,
pVolInfo, RT_MIN(_2K, pThis->cbBufferAlloc),
FileFsVolumeInformation);
if (NT_SUCCESS(rcNt) && NT_SUCCESS(Ios.Status))
pThis->uDirDev = pVolInfo->VolumeSerialNumber;
else
pThis->uDirDev = 0;
AssertCompile(sizeof(pThis->uDirDev) == sizeof(pVolInfo->VolumeSerialNumber));
/** @todo Grow RTDEV to 64-bit and add low dword of VolumeCreationTime to the top of uDirDev. */
}
/*
* Read more.
*/
NTSTATUS rcNt;
IO_STATUS_BLOCK Ios = RTNT_IO_STATUS_BLOCK_INITIALIZER;
if (pThis->enmInfoClass != (FILE_INFORMATION_CLASS)0)
{
#ifdef IPRT_WITH_NT_PATH_PASSTHRU
if (pThis->enmInfoClass == FileMaximumInformation)
{
Ios.Information = 0;
Ios.Status = rcNt = NtQueryDirectoryObject(pThis->hDir,
pThis->pabBuffer,
pThis->cbBufferAlloc,
RTDIR_NT_SINGLE_RECORD /*ReturnSingleEntry */,
pThis->fRestartScan,
&pThis->uObjDirCtx,
(PULONG)&Ios.Information);
}
else
#endif
rcNt = NtQueryDirectoryFile(pThis->hDir,
NULL /* Event */,
NULL /* ApcRoutine */,
NULL /* ApcContext */,
&Ios,
pThis->pabBuffer,
pThis->cbBufferAlloc,
pThis->enmInfoClass,
RTDIR_NT_SINGLE_RECORD /*ReturnSingleEntry */,
pThis->pNtFilterStr,
pThis->fRestartScan);
}
else
{
/*
* The first time around we have to figure which info class we can use
* as well as the right buffer size. We prefer an info class which
* gives us file IDs (Vista+ IIRC) and we prefer large buffers (for long
* ReFS file names and such), but we'll settle for whatever works...
*
* The windows 7 thru 8.1 CIFS servers have been observed to have
* trouble with large buffers, but weirdly only when listing large
* directories. Seems 0x10000 is the max. (Samba does not exhibit
* these problems, of course.)
*
* This complicates things. The buffer size issues causes an
* STATUS_INVALID_PARAMETER error. Now, you would expect the lack of
* FileIdBothDirectoryInformation support to return
* STATUS_INVALID_INFO_CLASS, but I'm not entirely sure if we can 100%
* depend on third IFSs to get that right. Nor, am I entirely confident
* that we can depend on them to check the class before the buffer size.
*
* Thus the mess.
*/
if (RT_MAKE_U64(RTNtCurrentPeb()->OSMinorVersion, RTNtCurrentPeb()->OSMajorVersion) > RT_MAKE_U64(0,5) /* > W2K */)
pThis->enmInfoClass = FileIdBothDirectoryInformation; /* Introduced in XP, from I can tell. */
else
pThis->enmInfoClass = FileBothDirectoryInformation;
rcNt = NtQueryDirectoryFile(pThis->hDir,
NULL /* Event */,
NULL /* ApcRoutine */,
NULL /* ApcContext */,
&Ios,
pThis->pabBuffer,
pThis->cbBufferAlloc,
pThis->enmInfoClass,
RTDIR_NT_SINGLE_RECORD /*ReturnSingleEntry */,
pThis->pNtFilterStr,
pThis->fRestartScan);
if (NT_SUCCESS(rcNt))
{ /* likely */ }
else
{
bool fRestartScan = pThis->fRestartScan;
for (unsigned iRetry = 0; iRetry < 2; iRetry++)
{
if ( rcNt == STATUS_INVALID_INFO_CLASS
|| rcNt == STATUS_INVALID_PARAMETER_8
|| iRetry != 0)
pThis->enmInfoClass = FileBothDirectoryInformation;
uint32_t cbBuffer = pThis->cbBufferAlloc;
if ( rcNt == STATUS_INVALID_PARAMETER
|| rcNt == STATUS_INVALID_PARAMETER_7
|| rcNt == STATUS_INVALID_NETWORK_RESPONSE
|| iRetry != 0)
{
cbBuffer = RT_MIN(cbBuffer / 2, _64K);
fRestartScan = true;
}
for (;;)
{
rcNt = NtQueryDirectoryFile(pThis->hDir,
NULL /* Event */,
NULL /* ApcRoutine */,
NULL /* ApcContext */,
&Ios,
pThis->pabBuffer,
cbBuffer,
pThis->enmInfoClass,
RTDIR_NT_SINGLE_RECORD /*ReturnSingleEntry */,
pThis->pNtFilterStr,
fRestartScan);
if ( NT_SUCCESS(rcNt)
|| cbBuffer == pThis->cbBufferAlloc
|| cbBuffer <= sizeof(*pThis->uCurData.pBothId) + sizeof(WCHAR) * 260)
break;
/* Reduce the buffer size agressivly and try again. We fall back to
FindFirstFile values for the final lap. This means we'll do 4 rounds
with the current initial buffer size (64KB, 8KB, 1KB, 0x278/0x268). */
cbBuffer /= 8;
if (cbBuffer < 1024)
cbBuffer = pThis->enmInfoClass == FileIdBothDirectoryInformation
? sizeof(*pThis->uCurData.pBothId) + sizeof(WCHAR) * 260
: sizeof(*pThis->uCurData.pBoth) + sizeof(WCHAR) * 260;
}
if (NT_SUCCESS(rcNt))
{
pThis->cbBufferAlloc = cbBuffer;
break;
}
}
}
}
if (!NT_SUCCESS(rcNt))
{
/* Note! VBoxSVR and CIFS file systems both ends up with STATUS_NO_SUCH_FILE here instead of STATUS_NO_MORE_FILES. */
if (rcNt == STATUS_NO_MORE_FILES || rcNt == STATUS_NO_MORE_ENTRIES || rcNt == STATUS_NO_SUCH_FILE)
return VERR_NO_MORE_FILES;
return RTErrConvertFromNtStatus(rcNt);
}
pThis->fRestartScan = false;
AssertMsg( Ios.Information
> (pThis->enmInfoClass == FileMaximumInformation ? sizeof(*pThis->uCurData.pObjDir) : sizeof(*pThis->uCurData.pBoth)),
("Ios.Information=%#x\n", Ios.Information));
/*
* Set up the data members.
*/
pThis->uCurData.u = (uintptr_t)pThis->pabBuffer;
pThis->cbBuffer = Ios.Information;
int rc = rtDirNtCheckRecord(pThis);
pThis->fDataUnread = RT_SUCCESS(rc);
return rc;
}