Leaked source code of windows server 2003
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/*++
Copyright (c) 1989 Microsoft Corporation
Module Name:
read.c
Abstract:
This module implements the mini redirector call down routines pertaining to
read of file system objects.
Author:
Joe Linn [JoeLi] 7-March-1995
Revision History:
Balan Sethu Raman [SethuR] 7-October-1997
Notes:
The READ adn WRITE paths in the mini redirector have to contend with a number
of different variations based on the kind of the server and the capabilities
of the server.
Currently there are atleast four variations of the read operation that needs
to be supported.
1) SMB_COM_READ
This is the read operation of choice against all servers which
support old dialects of the SMB protocol ( < DF_LANMAN10 )
2) SMB_COM_READ_ANDX
This is the read operation of choice against all servers which
support read extensions in the new dialects of the SMB protocol
However READ_ANDX itself can be further customized based upon the
server capabilities. There are two dimensions in which this
change can occur -- large sized reads being supported and compressed
reads.
In addition the SMB protocol supports the following flavours of a READ
operation which are not supported in the redirector
1) SMB_COM_READ_RAW
This is used to initiate large transfers to a server. However this
ties up the VC exclusively for this operation. The large READ_ANDX
overcomes this by providing for large read operations which can
be multiplexed on the VC.
2) SMB_COM_READ_MPX,SMB_COM_READ_MPX_SECONDARY,
These operations were designed for a direct host client. The NT
redriector does not use these operations because the recent
changes to NetBt allows us to go directly over a TCP connection.
The implementation of a read operation in the RDR hinges upon two decisions --
selecting the type of command to use and decomposing the original read
operation into a number of smaller read operations while adhering to
protocol/server restrictions.
The exchange engine provides the facility for sending a packet to the server
and picking up the associated response. Based upon the amount of data to be
read a number of such operations need to be initiated.
This module is organized as follows ---
MRxSmbRead --
This represents the top level entry point in the dispatch vector for
read operations associated with this mini redirector.
MRxSmbBuildReadRequest --
This routine is used for formatting the read command to be sent to
the server. We will require a new routine for each new type of read
operation that we would like to support
SmbPseExchangeStart_Read --
This routine is the heart of the read engine. It farms out the
necessary number of read operations and ensures the continuation
of the local operation on completion for both synchronous and
asynchronous reads.
All the state information required for the read operation is captured in an
instance of SMB_PSE_ORDINARY_EXCHANGE. This state information can be split
into two parts - the generic state information and the state information
specific to the read operation. The read operation specific state information
has been encapsulated in SMB_PSE_OE_READWRITE field in the exchange instance.
The read operation begins with the instantiation of an exchange in MRxSmbRead
and is driven through the various stages based upon a state diagram. The
state diagram is encoded in the OpSpecificState field in the ordinary
exchange.
The state diagram associated with the read exchange is as follows
SmbPseOEInnerIoStates_Initial
|
|
|
V
---->SmbPseOEInnerIoStates_ReadyToSend
| |
| |
| |
| V
---SmbPseOEInnerIoStates_OperationOutstanding
|
|
|
V
SmbPseOEInnerIoStates_OperationCompleted
--*/
#include "precomp.h"
#pragma hdrstop
#pragma warning(error:4101) // Unreferenced local variable
#ifdef ALLOC_PRAGMA
#pragma alloc_text(PAGE, MRxSmbRead)
#pragma alloc_text(PAGE, MRxSmbBuildReadAndX)
#pragma alloc_text(PAGE, MRxSmbBuildCoreRead)
#pragma alloc_text(PAGE, MRxSmbBuildSmallRead)
#pragma alloc_text(PAGE, SmbPseExchangeStart_Read)
#pragma alloc_text(PAGE, MRxSmbFinishNoCopyRead)
#endif
//
// The local debug trace level
//
#define Dbg (DEBUG_TRACE_READ)
ULONG MRxSmbSrvReadBufSize = 0xffff; //use the negotiated size
ULONG MRxSmbReadSendOptions = 0; //use the default options
#define MIN_CHUNK_SIZE (0x1000)
NTSTATUS
MRxSmbBuildReadRequest(
PSMB_PSE_ORDINARY_EXCHANGE OrdinaryExchange);
#if DBG
VOID
MRxSmbValidateCompressedDataInfo(
PSMB_PSE_ORDINARY_EXCHANGE OrdinaryExchange);
#else
INLINE VOID
MRxSmbValidateCompressedDataInfo(
PSMB_PSE_ORDINARY_EXCHANGE OrdinaryExchange)
{
UNREFERENCED_PARAMETER(OrdinaryExchange);
}
#endif
NTSTATUS
MRxSmbRead(
IN PRX_CONTEXT RxContext
)
/*++
Routine Description:
This routine handles network read requests.
Arguments:
RxContext - the RDBSS context
Return Value:
NTSTATUS - The return status for the operation
--*/
{
NTSTATUS Status = STATUS_SUCCESS;
RxCaptureFcb;
RxCaptureFobx;
PMRX_SMB_FCB smbFcb = MRxSmbGetFcbExtension(capFcb);
PMRX_SRV_OPEN SrvOpen = capFobx->pSrvOpen;
PMRX_SMB_SRV_OPEN smbSrvOpen = MRxSmbGetSrvOpenExtension(SrvOpen);
PMRX_V_NET_ROOT VNetRootToUse = capFobx->pSrvOpen->pVNetRoot;
PSMB_PSE_ORDINARY_EXCHANGE OrdinaryExchange;
SMBFCB_HOLDING_STATE SmbFcbHoldingState = SmbFcb_NotHeld;
PAGED_CODE();
RxDbgTrace(+1, Dbg, ("MRxSmbRead\n", 0 ));
ASSERT( NodeType(capFobx->pSrvOpen) == RDBSS_NTC_SRVOPEN );
do {
IF_NOT_MRXSMB_CSC_ENABLED{
ASSERT(smbSrvOpen->hfShadow == 0);
} else {
if (smbSrvOpen->hfShadow != 0){
NTSTATUS ShadowReadNtStatus;
if (FlagOn(smbSrvOpen->Flags,SMB_SRVOPEN_FLAG_OPEN_SURROGATED)) {
if (smbFcb->SurrogateSrvOpen == NULL) {
//whoops....my surrogate closed.....
RxDbgTrace(-1, Dbg, ("MRxSmbRead surrogate closed!! rxc=%08lx\n", RxContext ));
return(STATUS_UNSUCCESSFUL);
}
VNetRootToUse = smbFcb->SurrogateSrvOpen->pVNetRoot;
} else if (FlagOn(smbSrvOpen->Flags,SMB_SRVOPEN_FLAG_NOT_REALLY_OPEN)) {
//whoops again........someone closed my handle!
RxDbgTrace(-1, Dbg, ("MRxSmbRead thruopen closed!! rxc=%08lx\n", RxContext ));
return(STATUS_UNSUCCESSFUL);
}
ShadowReadNtStatus = MRxSmbCscReadPrologue(RxContext,&SmbFcbHoldingState);
if (ShadowReadNtStatus != STATUS_MORE_PROCESSING_REQUIRED) {
RxDbgTrace(-1, Dbg, ("MRxSmbRead shadow hit with status=%08lx\n", ShadowReadNtStatus ));
return(ShadowReadNtStatus);
} else {
RxDbgTrace(0, Dbg, ("MRxSmbRead shadowmiss with status=%08lx\n", ShadowReadNtStatus ));
}
}
}
Status = SmbPseCreateOrdinaryExchange(
RxContext,
VNetRootToUse,
SMBPSE_OE_FROM_READ,
SmbPseExchangeStart_Read,
&OrdinaryExchange );
if (Status != STATUS_SUCCESS) {
RxDbgTrace(-1, Dbg, ("Couldn't get the smb buf!\n"));
goto FINALLY;
}
OrdinaryExchange->SmbFcbHoldingState = SmbFcbHoldingState;
OrdinaryExchange->pSmbCeSynchronizationEvent = &RxContext->SyncEvent;
Status = SmbPseInitiateOrdinaryExchange(OrdinaryExchange);
if (Status != STATUS_PENDING) {
BOOLEAN FinalizationComplete;
SmbFcbHoldingState = OrdinaryExchange->SmbFcbHoldingState;
FinalizationComplete = SmbPseFinalizeOrdinaryExchange(OrdinaryExchange);
ASSERT(FinalizationComplete);
} else {
// let the exchange engine take care it
SmbFcbHoldingState = SmbFcb_NotHeld;
}
if ((Status == STATUS_RETRY) &&
BooleanFlagOn(RxContext->Flags,RX_CONTEXT_FLAG_ASYNC_OPERATION)) {
MRxSmbResumeAsyncReadWriteRequests(RxContext);
Status = STATUS_PENDING;
}
} while (Status == STATUS_RETRY);
FINALLY:
RxDbgTrace(-1, Dbg, ("MRxSmbRead exit with status=%08lx\n", Status ));
if (SmbFcbHoldingState != SmbFcb_NotHeld) {
MRxSmbCscReleaseSmbFcb(
RxContext,
&SmbFcbHoldingState);
}
return(Status);
} // MRxSmbRead
NTSTATUS
SmbPseExchangeStart_Read(
SMBPSE_ORDINARY_EXCHANGE_ARGUMENT_SIGNATURE
)
/*++
Routine Description:
This is the start routine for read.
Arguments:
RxContext - the local context
OrdinaryExchange - the exchange instance
Return Value:
NTSTATUS - The return status for the operation
--*/
{
NTSTATUS Status;
PSMBSTUFFER_BUFFER_STATE StufferState = &OrdinaryExchange->AssociatedStufferState;
ULONG StartEntryCount;
PLOWIO_CONTEXT LowIoContext = &RxContext->LowIoContext;
PSMB_PSE_OE_READWRITE rw = &OrdinaryExchange->ReadWrite;
PSMBCEDB_SERVER_ENTRY pServerEntry = SmbCeGetExchangeServerEntry(OrdinaryExchange);
PSMBCE_SERVER pServer = SmbCeGetExchangeServer(OrdinaryExchange);
PSMBCE_NET_ROOT pNetRoot = SmbCeGetExchangeNetRoot(OrdinaryExchange);
RxCaptureFcb;
RxCaptureFobx;
PMRX_SRV_OPEN SrvOpen = capFobx->pSrvOpen;
PMRX_SMB_SRV_OPEN smbSrvOpen = MRxSmbGetSrvOpenExtension(SrvOpen);
PMRX_SMB_FCB SmbFcb = MRxSmbGetFcbExtension(capFcb);
PSMBCE_SESSION pSession = SmbCeGetExchangeSession(OrdinaryExchange);
BOOLEAN SynchronousIo =
!BooleanFlagOn(RxContext->Flags,RX_CONTEXT_FLAG_ASYNC_OPERATION);
PAGED_CODE();
RxDbgTrace(+1, Dbg, ("SmbPseExchangeStart_Read\n", 0 ));
ASSERT( (OrdinaryExchange->SmbCeFlags&SMBCE_EXCHANGE_ATTEMPT_RECONNECTS) == 0 );
ASSERT(OrdinaryExchange->Type == ORDINARY_EXCHANGE);
OrdinaryExchange->StartEntryCount++;
StartEntryCount = OrdinaryExchange->StartEntryCount;
// Ensure that the Fid is validated
SetFlag(OrdinaryExchange->Flags,SMBPSE_OE_FLAG_VALIDATE_FID);
for (;;) {
switch (OrdinaryExchange->OpSpecificState) {
case SmbPseOEInnerIoStates_Initial:
{
OrdinaryExchange->OpSpecificState = SmbPseOEInnerIoStates_ReadyToSend;
// If not a synchronous read, then continue here when resumed
if (!SynchronousIo) {
OrdinaryExchange->AsyncResumptionRoutine = SmbPseExchangeStart_Read;
}
MRxSmbSetInitialSMB(StufferState STUFFERTRACE(Dbg,'FC'));
rw->UserBufferBase = RxLowIoGetBufferAddress(RxContext);
rw->ByteOffsetAsLI.QuadPart = LowIoContext->ParamsFor.ReadWrite.ByteOffset;
rw->RemainingByteCount = LowIoContext->ParamsFor.ReadWrite.ByteCount;
//record if this is a msgmode/pipe operation......
if ((capFcb->pNetRoot->Type == NET_ROOT_PIPE) &&
(capFobx->PipeHandleInformation->ReadMode != FILE_PIPE_BYTE_STREAM_MODE) ) {
SetFlag(OrdinaryExchange->OpSpecificFlags,OE_RW_FLAG_MSGMODE_PIPE_OPERATION);
}
rw->ThisBufferOffset = 0;
rw->CompressedReadOrWrite = FALSE;
rw->PartialDataMdlInUse = FALSE;
rw->PartialExchangeMdlInUse = FALSE;
rw->UserBufferPortionLength = 0;
rw->ExchangeBufferPortionLength = 0;
}
//lack of break is intentional
case SmbPseOEInnerIoStates_ReadyToSend:
{
OrdinaryExchange->OpSpecificState = SmbPseOEInnerIoStates_OperationOutstanding;
ClearFlag(OrdinaryExchange->OpSpecificFlags,OE_RW_FLAG_SUCCESS_IN_COPYHANDLER);
OrdinaryExchange->SendOptions = MRxSmbReadSendOptions;
Status = MRxSmbBuildReadRequest(
OrdinaryExchange);
if (Status != STATUS_SUCCESS) {
RxDbgTrace(0, Dbg, ("bad read stuffer status........\n"));
goto FINALLY;
}
if (FlagOn(
LowIoContext->ParamsFor.ReadWrite.Flags,
LOWIO_READWRITEFLAG_PAGING_IO)) {
RxLog(
("PagingIoRead: rxc/offset/length %lx/%lx/%lx",
RxContext,
&rw->ByteOffsetAsLI,
rw->ThisByteCount
)
);
SmbLog(LOG,
SmbPseExchangeStart_Read,
LOGPTR(RxContext)
LOGULONG(rw->ByteOffsetAsLI.LowPart)
LOGULONG(rw->ThisByteCount));
}
InterlockedIncrement(&MRxSmbStatistics.ReadSmbs);
Status = SmbPseOrdinaryExchange(
SMBPSE_ORDINARY_EXCHANGE_ARGUMENTS,
SMBPSE_OETYPE_READ );
// If the status is PENDING, then we're done for now. We must
// wait until we're re-entered when the receive happens.
if (Status == STATUS_PENDING) {
ASSERT(!SynchronousIo);
goto FINALLY;
}
}
//lack of break is intentional
case SmbPseOEInnerIoStates_OperationOutstanding:
{
OrdinaryExchange->OpSpecificState = SmbPseOEInnerIoStates_ReadyToSend;
OrdinaryExchange->Status = OrdinaryExchange->SmbStatus;
if (OrdinaryExchange->SmbStatus == STATUS_RETRY) {
SmbCeUninitializeExchangeTransport((PSMB_EXCHANGE)OrdinaryExchange);
Status = SmbCeReconnect(SmbCeGetExchangeVNetRoot(OrdinaryExchange));
if (Status == STATUS_SUCCESS) {
rw->BytesReturned = 0;
OrdinaryExchange->SmbStatus = STATUS_SUCCESS;
Status = SmbCeInitializeExchangeTransport((PSMB_EXCHANGE)OrdinaryExchange);
ASSERT(Status == STATUS_SUCCESS);
if (Status != STATUS_SUCCESS) {
goto FINALLY;
}
} else {
goto FINALLY;
}
} else if (OrdinaryExchange->SmbStatus != STATUS_SUCCESS &&
FlagOn(pSession->Flags,SMBCE_SESSION_FLAGS_REMOTE_BOOT_SESSION)) {
switch (OrdinaryExchange->SmbStatus) {
case STATUS_IO_TIMEOUT:
case STATUS_BAD_NETWORK_PATH:
case STATUS_NETWORK_UNREACHABLE:
case STATUS_REMOTE_NOT_LISTENING:
case STATUS_USER_SESSION_DELETED:
case STATUS_CONNECTION_DISCONNECTED:
ASSERT(smbSrvOpen->DeferredOpenContext != NULL);
Status = SmbCeRemoteBootReconnect((PSMB_EXCHANGE)OrdinaryExchange, RxContext);
OrdinaryExchange->Status = STATUS_RETRY;
if (Status == STATUS_SUCCESS) {
// Resume the read from the previous offset.
OrdinaryExchange->SmbStatus = STATUS_SUCCESS;
SmbCeInitializeExchangeTransport((PSMB_EXCHANGE)OrdinaryExchange);
rw->BytesReturned = 0;
} else {
Status = STATUS_RETRY;
OrdinaryExchange->SmbStatus = STATUS_RETRY;
goto FINALLY;
}
break;
}
}
if (rw->BytesReturned > 0) {
if (rw->CompressedReadOrWrite) {
// The Server sent back a compressed response.
PUCHAR UserBufferPortion,ExchangeBufferPortion;
ULONG UserBufferPortionLength,ExchangeBufferPortionLength;
PUCHAR CompressedBuffer,CompressedTailBuffer;
ULONG CompressedBufferLength,CompressedTailBufferLength;
PMDL OriginalDataMdl = LowIoContext->ParamsFor.ReadWrite.Buffer;
UserBufferPortionLength = rw->UserBufferPortionLength;
ExchangeBufferPortionLength = rw->ExchangeBufferPortionLength;
rw->UserBufferPortionLength = 0;
if (rw->PartialDataMdlInUse) {
MmPrepareMdlForReuse(
&rw->PartialDataMdl);
rw->PartialDataMdlInUse = FALSE;
}
rw->ExchangeBufferPortionLength = 0;
if (rw->PartialExchangeMdlInUse) {
MmPrepareMdlForReuse(
&rw->PartialExchangeMdl);
rw->PartialExchangeMdlInUse = FALSE;
}
if (UserBufferPortionLength > 0) {
UserBufferPortion = (PCHAR)rw->UserBufferBase +
MmGetMdlByteCount(OriginalDataMdl) -
UserBufferPortionLength;
} else {
UserBufferPortion = NULL;
}
if (ExchangeBufferPortionLength > 0) {
ExchangeBufferPortion = StufferState->BufferBase;
} else {
ExchangeBufferPortion = NULL;
}
if (UserBufferPortionLength >= rw->CompressedDataInfoLength) {
RtlCopyMemory(
&rw->CompressedDataInfo,
UserBufferPortion,
rw->CompressedDataInfoLength);
UserBufferPortion += rw->CompressedDataInfoLength;
UserBufferPortionLength -= rw->CompressedDataInfoLength;
} else {
RtlCopyMemory(
&rw->CompressedDataInfo,
UserBufferPortion,
UserBufferPortionLength);
RtlCopyMemory(
((PUCHAR)&rw->CompressedDataInfo + UserBufferPortionLength),
ExchangeBufferPortion,
rw->CompressedDataInfoLength - UserBufferPortionLength);
ExchangeBufferPortionLength -= (rw->CompressedDataInfoLength
- UserBufferPortionLength);
ExchangeBufferPortion += (rw->CompressedDataInfoLength
- UserBufferPortionLength);
UserBufferPortionLength = 0;
}
if (UserBufferPortionLength > 0) {
CompressedBuffer = UserBufferPortion;
CompressedBufferLength = UserBufferPortionLength;
CompressedTailBuffer = ExchangeBufferPortion;
CompressedTailBufferLength = ExchangeBufferPortionLength;
} else {
CompressedBuffer = ExchangeBufferPortion;
CompressedBufferLength = ExchangeBufferPortionLength;
CompressedTailBuffer = NULL;
CompressedTailBufferLength = 0;
}
MRxSmbValidateCompressedDataInfo(
OrdinaryExchange);
OrdinaryExchange->Status =
RtlDecompressChunks(
(PCHAR)rw->UserBufferBase + rw->ThisBufferOffset,
LowIoContext->ParamsFor.ReadWrite.ByteCount - rw->ThisBufferOffset,
CompressedBuffer,
CompressedBufferLength,
CompressedTailBuffer,
CompressedTailBufferLength,
&rw->CompressedDataInfo);
rw->BytesReturned = rw->CompressedDataInfo.NumberOfChunks * MIN_CHUNK_SIZE;
{
LARGE_INTEGER Offset = rw->ByteOffsetAsLI;
Offset.QuadPart += rw->BytesReturned;
if (Offset.QuadPart > capFcb->Header.FileSize.QuadPart) {
DbgPrint("Truncating read size from %lx",
rw->BytesReturned);
rw->BytesReturned = (ULONG)( capFcb->Header.FileSize.QuadPart -
rw->ByteOffsetAsLI.QuadPart);
DbgPrint(" to %lx\n",rw->BytesReturned);
}
}
} else {
if (rw->PartialDataMdlInUse) {
MmPrepareMdlForReuse(
&rw->PartialDataMdl);
rw->PartialDataMdlInUse = FALSE;
}
}
} else {
if (OrdinaryExchange->Status == STATUS_SUCCESS) {
if (capFcb->pNetRoot->Type == NET_ROOT_PIPE){
OrdinaryExchange->Status = STATUS_PIPE_EMPTY;
} else {
OrdinaryExchange->Status = STATUS_END_OF_FILE;
}
}
}
rw->RemainingByteCount -= rw->BytesReturned;
if ((OrdinaryExchange->Status == STATUS_END_OF_FILE) &&
(RxContext->InformationToReturn > 0)) {
OrdinaryExchange->Status = STATUS_SUCCESS;
rw->RemainingByteCount = 0;
}
RxContext->InformationToReturn += rw->BytesReturned;
Status = OrdinaryExchange->Status;
if (Status != STATUS_RETRY) {
if (NT_ERROR(Status) || (rw->RemainingByteCount==0)) {
goto FINALLY;
}
if (capFcb->pNetRoot->Type != NET_ROOT_DISK) {
if (Status != STATUS_BUFFER_OVERFLOW) {
goto FINALLY;
} else {
ASSERT (rw->BytesReturned == rw->ThisByteCount);
}
}
}
//reset the smbstatus.....
rw->ByteOffsetAsLI.QuadPart += rw->BytesReturned;
rw->ThisBufferOffset += rw->BytesReturned;
rw->BytesReturned = 0;
MRxSmbSetInitialSMB(StufferState STUFFERTRACE(Dbg,'FC'));
break;
}
}
}
FINALLY:
if ( Status != STATUS_PENDING) {
// update shadow as appropriate............
IF_NOT_MRXSMB_CSC_ENABLED{
ASSERT(MRxSmbGetSrvOpenExtension(SrvOpen)->hfShadow == 0);
} else {
if (MRxSmbGetSrvOpenExtension(SrvOpen)->hfShadow != 0){
MRxSmbCscReadEpilogue(RxContext,&Status);
}
}
if (Status != STATUS_RETRY) {
if (OrdinaryExchange->SmbFcbHoldingState != SmbFcb_NotHeld) {
MRxSmbCscReleaseSmbFcb(
StufferState->RxContext,
&OrdinaryExchange->SmbFcbHoldingState);
}
SmbPseAsyncCompletionIfNecessary(OrdinaryExchange,RxContext);
} else {
// the exchange will be left hanging if STATUS_PENDING has been returned
ASSERT(!BooleanFlagOn(RxContext->Flags,RX_CONTEXT_FLAG_ASYNC_OPERATION));
RxContext->InformationToReturn = 0;
}
}
RxDbgTrace(-1, Dbg, ("SmbPseExchangeStart_Read exit w %08lx\n", Status ));
return Status;
} // SmbPseExchangeStart_Read
NTSTATUS
MRxSmbFinishNoCopyRead (
PSMB_PSE_ORDINARY_EXCHANGE OrdinaryExchange
)
{
PAGED_CODE();
return(OrdinaryExchange->NoCopyFinalStatus);
}
UCHAR
MRxSmbReadHandler_NoCopy (
IN OUT PSMB_PSE_ORDINARY_EXCHANGE OrdinaryExchange,
IN ULONG BytesIndicated,
IN ULONG BytesAvailable,
OUT ULONG *pBytesTaken,
IN PSMB_HEADER pSmbHeader,
OUT PMDL *pDataBufferPointer,
OUT PULONG pDataSize,
#if DBG
IN UCHAR ThisIsAReenter,
#endif
IN PRESP_READ_ANDX Response
)
/*++
Routine Description:
This routine causes the bytes from the message to be transferred to the user's
buffer. In order to do this, it takes enough bytes from the indication and
then crafts up an MDL to cause the transport to do the copy.
Arguments:
please refer to smbpse.c...the only place from which this may be called
Return Value:
UCHAR - a value representing the action that OE receive routine will perform.
options are discard (in case of an error),
copy_for_resume (never called after this is all debugged),
and normal
--*/
{
PSMBSTUFFER_BUFFER_STATE StufferState = &OrdinaryExchange->AssociatedStufferState;
PSMB_PSE_OE_READWRITE rw = &OrdinaryExchange->ReadWrite;
PRX_CONTEXT RxContext = OrdinaryExchange->RxContext;
PLOWIO_CONTEXT LowIoContext = &RxContext->LowIoContext;
PMDL OriginalDataMdl = LowIoContext->ParamsFor.ReadWrite.Buffer;
PBYTE UserBuffer,ExchangeBuffer;
ULONG BytesReturned,DataOffset,CompressedDataBytesReturned = 0;
ULONG UserBufferLength;
ULONG StartingOffsetInUserBuffer;
UCHAR ContinuationCode;
RxDbgTrace(+1, Dbg, ("MRxSmbFinishReadNoCopy\n"));
SmbPseOEAssertConsistentLinkageFromOE("MRxSmbFinishReadNoCopy:");
rw->CompressedReadOrWrite = BooleanFlagOn(pSmbHeader->Flags2,SMB_FLAGS2_COMPRESSED);
if (rw->CompressedReadOrWrite && !MRxSmbEnableCompression) {
rw->CompressedReadOrWrite = FALSE;
}
UserBufferLength = MmGetMdlByteCount(OriginalDataMdl);
UserBuffer = rw->UserBufferBase + rw->ThisBufferOffset;
ExchangeBuffer = StufferState->BufferBase;
switch (OrdinaryExchange->LastSmbCommand) {
case SMB_COM_READ_ANDX:
{
if (Response->WordCount != 12) {
OrdinaryExchange->Status = STATUS_INVALID_NETWORK_RESPONSE;
ContinuationCode = SMBPSE_NOCOPYACTION_DISCARD;
goto FINALLY;
}
BytesReturned = SmbGetUshort(&Response->DataLength);
DataOffset = SmbGetUshort(&Response->DataOffset);
if (rw->CompressedReadOrWrite) {
rw->CompressedDataInfoLength = SmbGetUshort(&Response->CdiLength);
CompressedDataBytesReturned = SmbGetUshort(&Response->ByteCount);
}
}
if (DataOffset > sizeof(SMB_HEADER)+sizeof(RESP_READ_ANDX)) {
OrdinaryExchange->Status = STATUS_INVALID_NETWORK_RESPONSE;
ContinuationCode = SMBPSE_NOCOPYACTION_DISCARD;
goto FINALLY;
}
break;
case SMB_COM_READ:
{
PRESP_READ CoreResponse = (PRESP_READ)Response; //recast response for core read
ASSERT(!rw->CompressedReadOrWrite);
if (Response->WordCount != 5) {
OrdinaryExchange->Status = STATUS_INVALID_NETWORK_RESPONSE;
ContinuationCode = SMBPSE_NOCOPYACTION_DISCARD;
goto FINALLY;
}
BytesReturned = SmbGetUshort(&CoreResponse->DataLength);
DataOffset = sizeof(SMB_HEADER)+FIELD_OFFSET(RESP_READ,Buffer[0]);
}
break;
}
if ( BytesReturned > rw->ThisByteCount ) {
//cut back if we got a bad response
BytesReturned = rw->ThisByteCount;
}
RxDbgTrace(0, Dbg, ("-->ByteCount,Offset,Returned,DOffset,Buffer=%08lx/%08lx/%08lx/%08lx/%08lx\n",
rw->ThisByteCount,
rw->ThisBufferOffset,
BytesReturned,DataOffset,UserBuffer
));
OrdinaryExchange->ContinuationRoutine = MRxSmbFinishNoCopyRead;
OrdinaryExchange->ReadWrite.BytesReturned = BytesReturned;
// now, move the data to the user's buffer If enough is showing, just copy it in.
if (rw->CompressedReadOrWrite) {
// The compressed data needs to be copied such that an inplace decompress
// can be attempted. In order to do so we exploit the fact that we have
// a preallocated SMB buffer as part of the exchange which spans one chunk
//
// This is accomplished by copying the compressed data returned at an offset
// greater than one chunk in the user buffer. The data returned from the
// server is copied to the tail portion of the user buffer using the
// preallocated buffer in the exchange if required.
//
// This leads to two possibilities
//
// 1) The compressed data returned from the server fits into
// the preallocated buffer in the exchange
//
// or alternatively
//
// 2) the compressed data returned from the server spans the tail
// portion of the user buffer and the preallocated buffer in the exchange
rw->ExchangeBufferPortionLength = min(
CompressedDataBytesReturned,
OrdinaryExchange->SmbBufSize);
rw->UserBufferPortionLength = CompressedDataBytesReturned -
rw->ExchangeBufferPortionLength;
StartingOffsetInUserBuffer = UserBufferLength -
rw->UserBufferPortionLength;
} else {
StartingOffsetInUserBuffer = rw->ThisBufferOffset;
rw->UserBufferPortionLength = BytesReturned;
rw->ExchangeBufferPortionLength = 0;
}
if (BytesIndicated >= (DataOffset +
rw->UserBufferPortionLength +
rw->ExchangeBufferPortionLength)) {
if (rw->CompressedReadOrWrite) {
if (rw->UserBufferPortionLength > 0) {
RtlCopyMemory(
UserBuffer,
((PBYTE)pSmbHeader)+DataOffset,
rw->UserBufferPortionLength);
}
if (rw->ExchangeBufferPortionLength > 0) {
RtlCopyMemory(
ExchangeBuffer,
((PBYTE)pSmbHeader) + DataOffset + rw->UserBufferPortionLength,
rw->ExchangeBufferPortionLength);
}
} else {
RtlCopyMemory(
UserBuffer,
((PBYTE)pSmbHeader)+DataOffset,
rw->UserBufferPortionLength);
}
*pBytesTaken = DataOffset +
rw->UserBufferPortionLength +
rw->ExchangeBufferPortionLength;
RxDbgTrace(-1, Dbg, ("MRxSmbFinishReadNoCopy copy fork\n" ));
ContinuationCode = SMBPSE_NOCOPYACTION_NORMALFINISH;
} else {
// otherwise, MDL it in. we use the smbbuf as an Mdl!
if (BytesIndicated < DataOffset) {
OrdinaryExchange->Status = STATUS_INVALID_NETWORK_RESPONSE;
ContinuationCode = SMBPSE_NOCOPYACTION_DISCARD;
goto FINALLY;
}
if (rw->UserBufferPortionLength > 0) {
rw->PartialDataMdlInUse = TRUE;
MmInitializeMdl(
&rw->PartialDataMdl,
0,
PAGE_SIZE + rw->UserBufferPortionLength);
IoBuildPartialMdl(
OriginalDataMdl,
&rw->PartialDataMdl,
(PCHAR)MmGetMdlVirtualAddress(OriginalDataMdl) + StartingOffsetInUserBuffer,
rw->UserBufferPortionLength);
}
if (rw->ExchangeBufferPortionLength > 0) {
rw->PartialExchangeMdlInUse = TRUE;
MmInitializeMdl(
&rw->PartialExchangeMdl,
0,
PAGE_SIZE + rw->ExchangeBufferPortionLength);
IoBuildPartialMdl(
StufferState->HeaderMdl,
&rw->PartialExchangeMdl,
MmGetMdlVirtualAddress( StufferState->HeaderMdl ),
rw->ExchangeBufferPortionLength);
}
if (rw->PartialDataMdlInUse) {
if (rw->PartialExchangeMdlInUse) {
rw->PartialDataMdl.Next = &rw->PartialExchangeMdl;
}
*pDataBufferPointer = &rw->PartialDataMdl;
} else {
*pDataBufferPointer = &rw->PartialExchangeMdl;
}
*pDataSize = rw->UserBufferPortionLength +
rw->ExchangeBufferPortionLength;
*pBytesTaken = DataOffset;
RxDbgTrace(-1, Dbg, ("MRxSmbFinishReadNoCopy mdlcopy fork \n" ));
ContinuationCode = SMBPSE_NOCOPYACTION_MDLFINISH;
}
FINALLY:
return ContinuationCode;
}
NTSTATUS
MRxSmbBuildReadRequest(
PSMB_PSE_ORDINARY_EXCHANGE OrdinaryExchange)
/*++
Routine Description:
This routine formats the appropriate type of read request issued to the
server
Arguments:
OrdinaryExchange - the exchange instance encapsulating the information
Return Value:
STATUS_SUCCESS if successful
--*/
{
NTSTATUS Status;
UCHAR SmbCommand;
ULONG SmbCommandSize;
BOOLEAN CompressedReadRequest;
ULONG OffsetLow,OffsetHigh;
PSMB_PSE_OE_READWRITE rw = &OrdinaryExchange->ReadWrite;
PSMBCEDB_SERVER_ENTRY pServerEntry = SmbCeGetExchangeServerEntry(OrdinaryExchange);
PSMBCE_SERVER pServer = SmbCeGetExchangeServer(OrdinaryExchange);
PSMBCE_NET_ROOT pNetRoot = SmbCeGetExchangeNetRoot(OrdinaryExchange);
PMRX_V_NET_ROOT pVNetRoot = SmbCeGetExchangeVNetRoot(OrdinaryExchange);
PRX_CONTEXT RxContext = OrdinaryExchange->RxContext;
PSMBSTUFFER_BUFFER_STATE StufferState = &OrdinaryExchange->AssociatedStufferState;
RxCaptureFcb;
RxCaptureFobx;
PLOWIO_CONTEXT LowIoContext = &RxContext->LowIoContext;
PMRX_SRV_OPEN SrvOpen = capFobx->pSrvOpen;
PMRX_SMB_SRV_OPEN smbSrvOpen = MRxSmbGetSrvOpenExtension(SrvOpen);
rw->ThisByteCount = min(rw->RemainingByteCount,pNetRoot->MaximumReadBufferSize);
OffsetLow = rw->ByteOffsetAsLI.LowPart;
OffsetHigh = rw->ByteOffsetAsLI.HighPart;
CompressedReadRequest = FALSE;
if (FlagOn(pServer->DialectFlags,DF_LANMAN10)) {
SmbCommand = SMB_COM_READ_ANDX;
SmbCommandSize = SMB_REQUEST_SIZE(NT_READ_ANDX);
if (MRxSmbEnableCompression &&
(pServer->Capabilities & COMPRESSED_DATA_CAPABILITY) &&
(capFcb->Attributes & FILE_ATTRIBUTE_COMPRESSED) &&
((rw->ThisByteCount & 0xfff) == 0 ) &&
((rw->ByteOffsetAsLI.LowPart & 0xfff) == 0 )) {
CompressedReadRequest = TRUE;
}
} else {
SmbCommandSize = SMB_REQUEST_SIZE(READ);
SmbCommand = SMB_COM_READ;
}
MRxSmbDumpStufferState(
1000,
"SMB w/ READ before stuffing",
StufferState);
Status = MRxSmbStartSMBCommand (
StufferState,
SetInitialSMB_Never,
SmbCommand,
SmbCommandSize,
NO_EXTRA_DATA,
NO_SPECIAL_ALIGNMENT,
RESPONSE_HEADER_SIZE_NOT_SPECIFIED,
0,0,0,0 STUFFERTRACE(Dbg,'FC'));
if (Status != STATUS_SUCCESS) {
return Status;
}
switch (SmbCommand) {
case SMB_COM_READ:
{
// below, we just set mincount==maxcount. rdr1 did this.......
MRxSmbStuffSMB (
StufferState,
"0wwdwB!",
// 0 UCHAR WordCount;
smbSrvOpen->Fid, // w _USHORT( Fid );
rw->ThisByteCount, // w _USHORT( Count );
OffsetLow, // d _ULONG( Offset );
rw->RemainingByteCount, // w _USHORT( Remaining );
// B! _USHORT( ByteCount );
SMB_WCT_CHECK(5) 0
// UCHAR Buffer[1];
);
}
break;
case SMB_COM_READ_ANDX:
{
PNT_SMB_HEADER NtSmbHeader = (PNT_SMB_HEADER)(StufferState->BufferBase);
BOOLEAN UseNtVersion;
ULONG Timeout = 0;
if (pVNetRoot->pNetRoot->Type == NET_ROOT_PIPE) {
Timeout = (ULONG)-1;
}
UseNtVersion = BooleanFlagOn(pServer->DialectFlags,DF_NT_SMBS);
if (UseNtVersion &&
FlagOn(
LowIoContext->ParamsFor.ReadWrite.Flags,
LOWIO_READWRITEFLAG_PAGING_IO)) {
SmbPutAlignedUshort(
&NtSmbHeader->Flags2,
SmbGetAlignedUshort(&NtSmbHeader->Flags2) | SMB_FLAGS2_PAGING_IO );
}
if (UseNtVersion &&
CompressedReadRequest) {
SmbPutAlignedUshort(
&NtSmbHeader->Flags2,
SmbGetAlignedUshort(&NtSmbHeader->Flags2) | SMB_FLAGS2_COMPRESSED);
}
IF_NOT_MRXSMB_CSC_ENABLED{
ASSERT(!FlagOn(smbSrvOpen->Flags,SMB_SRVOPEN_FLAG_OPEN_SURROGATED));
} else {
if (FlagOn(smbSrvOpen->Flags,SMB_SRVOPEN_FLAG_OPEN_SURROGATED)) {
SmbPutAlignedUshort(
&NtSmbHeader->Flags2,
SmbGetAlignedUshort(&NtSmbHeader->Flags2)|SMB_FLAGS2_PAGING_IO );
}
}
// below, we just set mincount==maxcount. rdr1 did this.......
MRxSmbStuffSMB (
StufferState,
"XwdwWdw",
// X UCHAR WordCount;
// UCHAR AndXCommand;
// UCHAR AndXReserved;
// _USHORT( AndXOffset );
smbSrvOpen->Fid, // w _USHORT( Fid );
OffsetLow, // d _ULONG( Offset );
rw->ThisByteCount, // w _USHORT( MaxCount );
SMB_OFFSET_CHECK(READ_ANDX,MinCount)
rw->ThisByteCount, // W _USHORT( MinCount );
Timeout, // d _ULONG( Timeout );
rw->RemainingByteCount, // w _USHORT( Remaining );
StufferCondition(UseNtVersion), "D",
SMB_OFFSET_CHECK(NT_READ_ANDX,OffsetHigh)
OffsetHigh, // D NTonly _ULONG( OffsetHigh );
//
STUFFER_CTL_NORMAL, "B!",
// B! _USHORT( ByteCount );
SMB_WCT_CHECK(((UseNtVersion)?12:10)) 0
// UCHAR Buffer[1];
);
}
break;
default:
break;
}
if (Status == STATUS_SUCCESS) {
MRxSmbDumpStufferState(
700,
"SMB w/ READ after stuffing",
StufferState);
InterlockedIncrement(&MRxSmbStatistics.SmallReadSmbs);
}
return Status;
}
#if DBG
VOID
MRxSmbValidateCompressedDataInfo(
PSMB_PSE_ORDINARY_EXCHANGE OrdinaryExchange)
/*++
Routine Description:
This routine validated the Compressed data info structure returned from the
server
Arguments:
OrdinaryExchange - the exchange instance encapsulating the information
--*/
{
PSMBCE_NET_ROOT pNetRoot;
PSMB_PSE_OE_READWRITE rw;
PCOMPRESSED_DATA_INFO pCompressedDataInfo;
ULONG RequestedReadLength,CompressedDataLength;
ULONG NumberOfChunks,ChunkSize;
USHORT i;
pNetRoot = SmbCeGetExchangeNetRoot(OrdinaryExchange);
rw = &OrdinaryExchange->ReadWrite;
pCompressedDataInfo = &rw->CompressedDataInfo;
RequestedReadLength = rw->ThisByteCount;
if ((pCompressedDataInfo->ChunkShift == 0) ||
(pCompressedDataInfo->ClusterShift == 0) ||
(pCompressedDataInfo->CompressionUnitShift == 0)) {
DbgPrint("Invalid CDI:%lx\n",pCompressedDataInfo);
//DbgBreakPoint();
}
ChunkSize = (1 << pCompressedDataInfo->ChunkShift);
if (ChunkSize == 0) {
DbgPrint("CDI: %lx Invalid Chunk Size\n",pCompressedDataInfo);
//DbgBreakPoint();
}
NumberOfChunks = RequestedReadLength / ChunkSize;
if ((pCompressedDataInfo->NumberOfChunks == 0) ||
(pCompressedDataInfo->NumberOfChunks > NumberOfChunks)){
DbgPrint("CDI: %lx, Invalid number Of Chunks returned\n",pCompressedDataInfo);
}
CompressedDataLength = 0;
for (i = 0; i < pCompressedDataInfo->NumberOfChunks; i++) {
CompressedDataLength += pCompressedDataInfo->CompressedChunkSizes[i];
}
if (CompressedDataLength > RequestedReadLength) {
DbgPrint("CDI: %lx, More data returned than requested\n",pCompressedDataInfo);
//DbgBreakPoint();
}
}
#endif