/*
* PROJECT: Alcyone Kernel
* LICENSE: BSD Clause 3
* PURPOSE: Cache Controller:: MDL Handler
* NT KERNEL: 5.11.9360
* COPYRIGHT: 2023-2029 Dibymartanda Samanta <>
*
*/
#include <ntoskrnl.h>
#define NTDEBUG
#include <debug.h>
#include "ccinternal.hpp"
#include "ccmdl.hpp"
extern "C"
/*Internal Function*/
VOID
NTAPI
CcMdlReadComplete2 (
IN PFILE_OBJECT FileObject,
IN PMDL MdlChain
)
{
/* Check if MDL Chain is Valid */
if (MdlChain)
{
/*Iterate Through the MDL CHain*/
for( auto it = begin(MdlChain); it != end(MdlChain);++it)
{
/*Unlock the memory pages associated with the MDL*/
MmUnlockPages(*it);
/*Free The MDL */
IoFreeMdl(*it);
}
}
}
CcMdlWriteComplete2(IN PFILE_OBJECT FileObject,
IN PLARGE_INTEGER FileOffset,
IN PMDL MdlChain)
{
PLARGE_INTEGER FOffset = nullptr;
NTSTATUS Exception = {0};
PIO_STATUS_BLOCK IoStatus = nullptr;
for( auto it = begin(MdlChain); it != end(MdlChain);++it)
{
if (!(MdlChain->MdlFlags & 2) == 0) )
{
MmUnlockPages(*it);
}
if ( (FileObject->Flags & 16) != 0 )
{
MmFlushSection((*it)->ByteCount, SharedCacheMap, &IoStatus, 1);
if ( !NTSTATUS(IoStatus.Status) )
Exception = IoStatus.Status;
}
else
{
CcSetDirtyInMask(SharedCacheMap, &FOffset, (*it)->ByteCount);
}
FOffset.QuadPart += (*it)->ByteCount;
}
if (!(MdlChain->MdlFlags & 2) == 0))
{
SpinLockGuard lockGuard(LockQueueMasterLock);
CcDecrementOpenCount(SharedCacheMap);
}
if (!NT_SUCCESS(Exception))
{
RtlRaiseStatus(FsRtlNormalizeNtstatus(Exception, WRITE_EXCEPTION));
}
/* Write Operation is COmplete, Now Free the MDL Chain*/
for( auto it = begin(MdlChain); it != end(MdlChain);++it)
{
/*Free The MDL */
IoFreeMdl(*it);
}
}
/* External Function */
VOID
NTAPI
CcMdlRead (
IN PFILE_OBJECT FileObject,
IN PLARGE_INTEGER FileOffset,
IN ULONG Length,
OUT PMDL * MdlChain,
OUT PIO_STATUS_BLOCK IoStatus)
{
ULONG LENGTH_FINAL = Length;
PVOID VirtualAddress = nullptr;
PVACB VACB = nullptr;
ULONG ReceivedLength = {0};
ULONG Information = {0};
PMDL Allocated = nullptr;
LARGE_INTEGER FOffset = {0};
PSHARED_CACHE_MAP sharedcachmap = FileObject->SectionObjectPointer->SharedCacheMap;
PRIVATE_CACHE_MAP PrivateCacheMap = FileObject->PrivateCacheMap;
PVOID VirtualAddress = nullptr;
LARGE_INTEGER Offset_Lenghth = {0};
_try
{
/* Iterate until it is final length is null*/
while(Length != NULL)
{
VirtualAddress = static_cast<void*>(CcGetVirtualAddress(sharedcachmap, &VACB, FOffset,(LARGE_INTEGER)&ReceivedLength, 0));
INT PagePriority = static_cast<int>(((&sharedcachmap->NodeTypeCode >> 18) & 7));
if ((sharedcachmap->Flags & 8)== null )
{
/* Our Memory Manager doesn't support prefetching yet, will be added in 2025*/
//CcFetchDataForRead(FileObject,&FOffset,Length,Wait_Type_MDL_Read,&FaultedData,&VACB,PagePriority,MDL_READTYPE_DiskIoAttribution); // Return
}
if ( ReceivedLength > Length )
{
ReceivedLength = Length;
}
Offset_Lenghth = FOffset.QuadPart + static_cast<LONGLONG>(ReceivedLength);
/* Allocate the MDL ,it is not associated with Specific IRP*/
Allocated = IoAllocateMdl(VirtualAddress,ReceivedLength , false, false, optional_irp);
/* Assign the MDL to MmProbeAndLockPages to prevent Page Fault/ Data Corruption */
MmProbeAndLockPages(Allocated, KernelMode, IoReadAccess);
/* Free the VACB */
CcFreeVirtualAddress(VACB);
/* Now Update the MDL Chain with allocated one */
/* Check if Valid MDL Chain already exist, if so update it with allocated one else assign MDL Chain with one we allocated */
if ( *MdlChain != NULL)
{ for( auto it = begin(MdlChain); it != end(MdlChain);++it)
{
*it = Allocated;
}
}
else
{
*MdlChain = Allocated;
}
FOffset.QuadPart = Offset_Lenghth.QuadPart;
/* Update the IOSTATUS Information FLag */
Information += ReceivedLength;
/* Adjust the length , else you will be in mess of a infinite nonsensical loop fighting with Exception Handler */
Length -= ReceivedLength;
}
}
_finally{
if ( (FileObject->Flags & 0x100000) = = 0 ||(&PrivateCacheMap->NodeType_UlongFlags & 0x20000 == 0) && FaultedData )
{
CcScheduleReadAheadEx(FileObject, FileOffset,Length,NULL);
_InterlockedOr(&PrivateCacheMap->NodeType_UlongFlags, FLAG_UPDATE_READAHEAD);
}
/* No mater What , Catch History must be updated even if Aliens Invasion Happens that day*/
/* UPDATE CATCH HISTORY */
InterlockedExchange64(&PrivateCachemap->FileOffset1,PrivateCachemap->FileOffset2);
InterlockedExchange64(&PrivateCachemap->BeyondLastByte1,PrivateCachemap->BeyondLastByte2);
InterlockedExchange64(&PrivateCachemap->FileOffset2,*FileOffset);
LONG LONG FinalLength =FileOffset->QuadPart+ static_cast<LONGLONG>(Length);
InterlockedExchange64(&PrivateCachemap->BeyondLastByte2.Quadpart,FinalLength);
/* Update Shared Cachemap Flags */
if ( (SharedCacheMap->Flags & 8) != 0 )
{
SpinLockGuard lockGuard(LockQueueMasterLock);
SharedCacheMap->Flags &= ~8;
}
/* Update IRP Bytes */
IoStatus->Status = Status_Sucess;
IoStatus->Information = Information;
}
}
VOID
NTAPI
CcMdlReadComplete(IN PFILE_OBJECT FileObject,
IN PMDL MdlChain)
{
PDEVICE_OBJECT RelatedDeviceObject = nullptr;
PFAST_IO_DISPATCH FastIoDispatch = nullptr;
IO_MDLREAD_COMPLETE_ROUTINE MdlReadComplete;
RelatedDeviceObject = IoGetRelatedDeviceObject(FileObject);
FastIoDispatch = RelatedDeviceObject->DriverObject->FastIoDispatch;
if(MdlChain == nullptr)
{ DBGPRINT("Invalid MDLChain \n");
return;
}
if (FastIoDispatch &&
FastIoDispatch->SizeOfFastIoDispatch >= sizeof(FAST_IO_DISPATCH) &&
(MdlReadComplete = FastIoDispatch->MdlReadComplete) != NULL &&
MdlReadComplete(FileObject, MdlChain, RelatedDeviceObject))
{
/* Faster Fast I/O MDL path successful, if it fails, we will go for our slower implementation*/
return;
}
CcMdlReadComplete2(FileObject, MdlChain);
}
VOID
NTAPI
CcMdlWriteAbort(IN PFILE_OBJECT FileObject,
IN PMDL MdlChain)
{
PSHARED_CACHE_MAP SharedCacheMap = FileObject->SectionObjectPointer->SharedCacheMap;
for( auto it = begin(MdlChain); it != end(MdlChain);++it)
{
if ((MdlChain->MdlFlags & 2) != 0 )
{
MmUnlockPages(*it);
}
IoFreeMdl(*it);
}
if ( (MdlChain->MdlFlags & 2) != 0 )
{
SpinLockGuard lockGuard(LockQueueMasterLock);
CcDecrementOpenCount(SharedCacheMap);
}
}
VOID
NTAPI
CcMdlWriteComplete(IN PFILE_OBJECT FileObject,
IN PLARGE_INTEGER FileOffset,
IN PMDL MdlChain)
{
PDEVICE_OBJECT RelatedDeviceObject = nullptr;
PFAST_IO_DISPATCH FastIoDispatch = nullptr;
IO_MDLWRITE_COMPLETE_ROUTINE MdlWriteComplete;
if(MdlChain == nullptr)
{ DBGPRINT("Invalid MDLChain \n");
return;
}
RelatedDeviceObject = IoGetRelatedDeviceObject(FileObject);
FastIoDispatch = RelatedDeviceObject->DriverObject->FastIoDispatch;
if (FastIoDispatch &&
FastIoDispatch->SizeOfFastIoDispatch >= sizeof(FAST_IO_DISPATCH) &&
(MdlWriteComplete = FastIoDispatch->MdlWriteComplete) != NULL &&
MdlWriteComplete(FileObject, FileOffset, MdlChain, RelatedDeviceObject))
{
/* Faster Fast I/O MDL path successful, if it fails, we will go for our slower implementation*/
return;
}
CcMdlWriteComplete2(FileObject, FileOffset, MdlChain);
}
VOID
NTAPI
CcPrepareMdlWrite(IN PFILE_OBJECT FileObject,
IN PLARGE_INTEGER FileOffset,
IN ULONG Length,
OUT PMDL *MdlChain,
OUT PIO_STATUS_BLOCK IoStatus)
{
PMDL Mdl = nullptr;
PVOID VirtualAddress = nullptr;
PSHARED_CACHE_MAP SharedCacheMap = FileObject->SectionObjectPointer->SharedCacheMap;
PLARGE_INTEGER FOffset = nullptr;
PLARGE_INTEGER ReadAheadLenghth = nullptr;
LARGE_INTEGER Final_Length = {0};
LARGE_INTEGER ReadAhead_Length = {0};
LARGE_INTEGER Information = {0};
ULONG ReceivedLength = {0};
ULONG SavedState = {0};
ULONG ZeroOpsFlags = {0};
PVACB Vacb = nullptr;
BOOL MapFlag = false;
PKTHREAD currentThread = nullptr;
UCHAR SavedState ={0};
if ((FileObject->Flags & 0x10) == 0)
{
if (IoIsFileOriginRemote(FileObject) && !CcCanIWriteStream(FileObject, Length, 0, 0))
RtlRaiseStatus(STATUS_INSUFFICIENT_RESOURCES );
}
_try{
while (Length != NULL)
{
VirtualAddress = CcGetVirtualAddress(SharedCacheMap, &ReceivedLength, &Vacb, 0, FOffset, ReadAheadLenghth);
/* Should not exceed PageLimit */
if (ReceivedLength > Length)
ReceivedLength = Length;
Final_Length.QuadPart = FileOffset->QuadPart;
ReadAhead_Length = (ReadAheadLenghth->QuadPart) + (FileOffset->QuadPart);
ZeroOpsFlags = 2;
/* Set the flags for CcMapAndRead */
if ((FOffset->Lowpart & 0xFFF) == 0 && ReceivedLength >= 0x1000)
{
ZeroOpsFlags = 3;
}
if ((Final_Length & 0xFFF) == 0)
{
ZeroOpsFlags |= 4;
}
KeAcquireInStackQueuedSpinLock(&SharedCacheMap->BcbSpinLock, &LockHandle);
LONGLONG ReadAhead_State = SharedCacheMap->ValidDataGoal.QuadPart - (ReadAheadLenghth << 12 | (FOffset->Lowpart & 0xFFFFF000));
ReadAheadLenghth = static_cast<ULONG>(ReadAhead_State >> 32);
KeReleaseInStackQueuedSpinLock(&LockHandle);
if (ReadAheadLenghth > 0)
{
SavedState = static_cast<ULONG>(ReadAhead_State);
}
else if ((ReadAheadLenghth & 0x80000000) != 0 || (SavedState = static_cast<ULONG>(ReadAhead_State)) == 0)
{
ZeroOpsFlags |= 7;
}
if (!ReadAheadLenghth && SavedState <= 0x1000)
{
ZeroOpsFlags |= 6;
}
MapFlag = CcMapAndRead(ReceivedLength, ZeroOpsFlags, 1, VirtualAddress);
if(!MapFlag)
{
DBGPRINT(" CcPrepareMdlWrite:: Page Maping Failed \n");
}
Mdl = IoAllocateMdl(VirtualAddress, ReceivedLength, FALSE, FALSE, NULL);
if (!Mdl)
RtlRaiseStatus(STATUS_INSUFFICIENT_RESOURCES );
currentThread = KeGetCurrentThread();
SavedState = currentThread->UserIdealProcessor ;
savedDisablePageFaultClustering = currentThread->DisablePageFaultClustering;
currentThread->DisablePageFaultClustering = 1;
MmProbeAndLockPages(Mdl, KernelMode, IoWriteAccess);
currentThread->UserIdealProcessor = SavedState;
currentThread->DisablePageFaultClustering = savedDisablePageFaultClustering;
/* Update the Read Aheas Stats*/
KeAcquireInStackQueuedSpinLock(&SharedCacheMap->BcbSpinLock, &LockHandle);
if ( ReadAhead_Length.QuadPart > SharedCacheMap->ValidDataGoal.QuadPart )
{
SharedCacheMap->ValidDataGoal.QuadPart = ReadAhead_Length.QuadPart;
}
KeReleaseInStackQueuedSpinLock(&LockHandle);
/*Free The VACB and Dereferance it*/
CcFreeVirtualAddress(Vacb);
Vacb = nullptr;
/* Check if Valid MDL Chain already exist, if so update it with allocated one else assign MDL Chain with one we allocated */
if (*MdlChain)
{
/*MDL Iterator in Action, While Loopers take your C++ Coolaid now */
for(auto it = begin(MdlChain); it != end(MdlChain);++it)
{
*it = Allocated;
}
}
else
{
*MdlChain = Mdl;
}
Mdl = nullptr;
FOffset.QuadPart = Final_Length;
ReadAheadLenghth = ReadAhead_Length;
/* Update the IOSTATUS Information FLag with amount of Byte Counts */
Information += ReceivedLength;
/* Adjust the length as per bytes written, else you will be in mess of a infinite nonsensical loop, Might result in Kaboom aka BSOD */
Length -= ReceivedLength;
}
}
_finally{
IoStatus->Status = STATUS_SUCESS;
IoStatus->Information = Information;
KIRQL LAST_IRQL = KeAcquireQueuedSpinLock(LockQueueMasterLock);
SharedCacheMap->OpenCount++;
KeReleaseQueuedSpinLock(LockQueueMasterLock, LAST_IRQL);
}