+++ /dev/null
-/*
-* PROJECT: Filesystem Filter Manager
-* LICENSE: GPL - See COPYING in the top level directory
-* FILE: drivers/filters/fltmgr/Object.c
-* PURPOSE: Miscellaneous library functions
-* PROGRAMMERS: Ged Murphy (gedmurphy@reactos.org)
-*/
-
-// NOTE: Split this file into filter object and device object functions
-// when the code base grows sufficiently
-
-/* INCLUDES ******************************************************************/
-
-#include "fltmgr.h"
-#include "fltmgrint.h"
-
-#define NDEBUG
-#include <debug.h>
-
-
-/* DATA *********************************************************************/
-
-#define ExpChangePushlock(x, y, z) InterlockedCompareExchangePointer((PVOID*)x, (PVOID)y, (PVOID)z)
-
-//
-// Pushlock bits
-//
-#define EX_PUSH_LOCK_LOCK_V ((ULONG_PTR)0x0)
-#define EX_PUSH_LOCK_LOCK ((ULONG_PTR)0x1)
-#define EX_PUSH_LOCK_WAITING ((ULONG_PTR)0x2)
-#define EX_PUSH_LOCK_WAKING ((ULONG_PTR)0x4)
-#define EX_PUSH_LOCK_MULTIPLE_SHARED ((ULONG_PTR)0x8)
-#define EX_PUSH_LOCK_SHARE_INC ((ULONG_PTR)0x10)
-#define EX_PUSH_LOCK_PTR_BITS ((ULONG_PTR)0xf)
-
-/* EXPORTED FUNCTIONS ******************************************************/
-
-
-NTSTATUS
-FLTAPI
-FltObjectReference(_Inout_ PVOID Object)
-{
- if (!FltpExAcquireRundownProtection(&((PFLT_OBJECT)Object)->RundownRef))
- {
- return STATUS_FLT_DELETING_OBJECT;
- }
-
- return STATUS_SUCCESS;
-}
-
-VOID
-FLTAPI
-FltObjectDereference(_Inout_ PVOID Object)
-{
- FltpExReleaseRundownProtection(&((PFLT_OBJECT)Object)->RundownRef);
-}
-
-
-_Acquires_lock_(_Global_critical_region_)
-_IRQL_requires_max_(APC_LEVEL)
-VOID
-FLTAPI
-FltAcquirePushLockExclusive(_Inout_ _Requires_lock_not_held_(*_Curr_) _Acquires_lock_(*_Curr_) PEX_PUSH_LOCK PushLock)
-{
- KeEnterCriticalRegion();
-
- /* Try acquiring the lock */
- if (InterlockedBitTestAndSet((PLONG)PushLock, EX_PUSH_LOCK_LOCK_V))
- {
- /* Someone changed it, use the slow path */
- ExfAcquirePushLockExclusive(PushLock);
- }
-
- /* Sanity check */
- FLT_ASSERT(PushLock->Locked);
-}
-
-
-_Acquires_lock_(_Global_critical_region_)
-_IRQL_requires_max_(APC_LEVEL)
-VOID
-FLTAPI
-FltAcquirePushLockShared(_Inout_ _Requires_lock_not_held_(*_Curr_) _Acquires_lock_(*_Curr_) PEX_PUSH_LOCK PushLock)
-{
- EX_PUSH_LOCK NewValue;
-
- KeEnterCriticalRegion();
-
- /* Try acquiring the lock */
- NewValue.Value = EX_PUSH_LOCK_LOCK | EX_PUSH_LOCK_SHARE_INC;
- if (ExpChangePushlock(PushLock, NewValue.Ptr, 0))
- {
- /* Someone changed it, use the slow path */
- ExfAcquirePushLockShared(PushLock);
- }
-
- /* Sanity checks */
- ASSERT(PushLock->Locked);
-}
-
-_Releases_lock_(_Global_critical_region_)
-_IRQL_requires_max_(APC_LEVEL)
-VOID
-FLTAPI
-FltReleasePushLock(_Inout_ _Requires_lock_held_(*_Curr_) _Releases_lock_(*_Curr_) PEX_PUSH_LOCK PushLock)
-{
- EX_PUSH_LOCK OldValue = *PushLock;
- EX_PUSH_LOCK NewValue;
-
- /* Sanity checks */
- FLT_ASSERT(OldValue.Locked);
-
- /* Check if the pushlock is shared */
- if (OldValue.Shared > 1)
- {
- /* Decrease the share count */
- NewValue.Value = OldValue.Value - EX_PUSH_LOCK_SHARE_INC;
- }
- else
- {
- /* Clear the pushlock entirely */
- NewValue.Value = 0;
- }
-
- /* Check if nobody is waiting on us and try clearing the lock here */
- if ((OldValue.Waiting) ||
- (ExpChangePushlock(PushLock, NewValue.Ptr, OldValue.Ptr) !=
- OldValue.Ptr))
- {
- /* We have waiters, use the long path */
- ExfReleasePushLock(PushLock);
- }
-
- KeLeaveCriticalRegion();
-}
-
-
-
-/* INTERNAL FUNCTIONS ******************************************************/
-
-VOID
-FltpExInitializeRundownProtection(_Out_ PEX_RUNDOWN_REF RundownRef)
-{
- ExInitializeRundownProtection(RundownRef);
-}
-
-BOOLEAN
-FltpExAcquireRundownProtection(_Inout_ PEX_RUNDOWN_REF RundownRef)
-{
- return ExAcquireRundownProtection(RundownRef);
-}
-
-BOOLEAN
-FltpExReleaseRundownProtection(_Inout_ PEX_RUNDOWN_REF RundownRef)
-{
- ExReleaseRundownProtection(RundownRef);
- return TRUE;
-}
-
-BOOLEAN
-FltpExRundownCompleted(_Inout_ PEX_RUNDOWN_REF RundownRef)
-{
- return _InterlockedExchange((PLONG)RundownRef, 1);
-}
-
-NTSTATUS
-NTAPI
-FltpObjectRundownWait(_Inout_ PEX_RUNDOWN_REF RundownRef)
-{
- //return FltpExWaitForRundownProtectionRelease(RundownRef);
- return 0;
-}
-
-NTSTATUS
-FltpGetBaseDeviceObjectName(_In_ PDEVICE_OBJECT DeviceObject,
- _Inout_ PUNICODE_STRING ObjectName)
-{
- PDEVICE_OBJECT BaseDeviceObject;
- NTSTATUS Status;
-
- /*
- * Get the lowest device object on the stack, which may be the
- * object we were passed, and lookup the name for that object
- */
- BaseDeviceObject = IoGetDeviceAttachmentBaseRef(DeviceObject);
- Status = FltpGetObjectName(BaseDeviceObject, ObjectName);
- ObDereferenceObject(BaseDeviceObject);
-
- return Status;
-}
-
-NTSTATUS
-FltpGetObjectName(_In_ PVOID Object,
- _Inout_ PUNICODE_STRING ObjectName)
-{
- POBJECT_NAME_INFORMATION ObjectNameInfo = NULL;
- OBJECT_NAME_INFORMATION LocalNameInfo;
- ULONG ReturnLength;
- NTSTATUS Status;
-
- if (ObjectName == NULL)
- return STATUS_INVALID_PARAMETER;
-
- /* Get the size of the buffer required to hold the nameinfo */
- Status = ObQueryNameString(Object,
- &LocalNameInfo,
- sizeof(LocalNameInfo),
- &ReturnLength);
- if (Status == STATUS_INFO_LENGTH_MISMATCH)
- {
- ObjectNameInfo = ExAllocatePoolWithTag(PagedPool,
- ReturnLength,
- FM_TAG_UNICODE_STRING);
- if (ObjectNameInfo == NULL) return STATUS_INSUFFICIENT_RESOURCES;
-
- /* Get the actual name info now we have the buffer to hold it */
- Status = ObQueryNameString(Object,
- ObjectNameInfo,
- ReturnLength,
- &ReturnLength);
- }
-
-
- if (NT_SUCCESS(Status))
- {
- /* Make sure the buffer we were passed is large enough to hold the string */
- if (ObjectName->MaximumLength < ObjectNameInfo->Name.Length)
- {
- /* It wasn't, let's enlarge the buffer */
- Status = FltpReallocateUnicodeString(ObjectName,
- ObjectNameInfo->Name.Length,
- FALSE);
-
- }
-
- if (NT_SUCCESS(Status))
- {
- /* Copy the object name into the callers buffer */
- RtlCopyUnicodeString(ObjectName, &ObjectNameInfo->Name);
- }
- }
-
- if (ObjectNameInfo)
- {
- ExFreePoolWithTag(ObjectNameInfo, FM_TAG_UNICODE_STRING);
- }
-
- return Status;
-}
-
-ULONG
-FltpObjectPointerReference(_In_ PFLT_OBJECT Object)
-{
- PULONG Result;
-
- /* Store the old count and increment */
- Result = &Object->PointerCount;
- InterlockedIncrement((PLONG)&Object->PointerCount);
-
- /* Return the initial value */
- return *Result;
-}
-
-VOID
-FltpObjectPointerDereference(_In_ PFLT_OBJECT Object)
-{
- if (!InterlockedDecrement((PLONG)Object->PointerCount))
- {
- // Cleanup
- FLT_ASSERT(FALSE);
- }
-}
\ No newline at end of file
projects / reactos.git / blobdiff