// HANDLE.CPP -- Implementation of handle object
// Copyright (C) 1999 by Walter Oney
// All rights reserved

#include "precomp.h"
#include "stddcls.h"
#include "driver.h"
#include "cons_def.h"

extern PFILE_OBJECT 		g_alarmfop;
extern PDEVICE_EXTENSION 	g_alarmpdx;
extern PFILE_OBJECT 		g_logfop;
extern PDEVICE_EXTENSION 	g_logpdx;

///////////////////////////////////////////////////////////////////////////////

VOID CloseHandle(PDEVICE_EXTENSION pdx, PFILE_OBJECT fop)
	{							// CloseHandle
	PHANDLE_OBJECT hop = FindHandle(pdx, fop);
	KIRQL oldirql;
	if (!hop)
		return;
	KeAcquireSpinLock(&pdx->lockHandles, &oldirql);
	RemoveEntryList(&hop->link);
	KeReleaseSpinLock(&pdx->lockHandles, oldirql);

	ReleaseHandle(hop);
	g_alarmfop=NULL;
	g_alarmpdx=NULL;
	g_logfop=NULL;
	g_logpdx=NULL;
	//ReleaseHandle(hop);
	}							// CloseHandle

///////////////////////////////////////////////////////////////////////////////

VOID DeregisterEvent(PDEVICE_EXTENSION pdx, PFILE_OBJECT fop)
	{							// DeregisterEvent
	PHANDLE_OBJECT hop = FindHandle(pdx, fop);
	if (!hop)
		return;
	if (hop->pevent)
		{						// dereference event
		ObDereferenceObject(hop->pevent);
		hop->pevent = NULL;
		}						// dereference vent
	ReleaseHandle(hop);
	}							// DeregisterEvent

///////////////////////////////////////////////////////////////////////////////

PHANDLE_OBJECT FindHandle(PDEVICE_EXTENSION pdx, PFILE_OBJECT fop)
	{							// FindHandle

	// The FsContext and FsContext2	fields of the file object are for use by
	// whoever actually implements the IRP_MJ_CREATE (us, this case). We 
	// save our handle object pointer there in OpenHandle

	PHANDLE_OBJECT hop = (PHANDLE_OBJECT) fop->FsContext;
	if (hop)
		++hop->refcnt;
	return hop;
	}							// FindHandle

///////////////////////////////////////////////////////////////////////////////

PHANDLE_OBJECT OpenHandle(PDEVICE_EXTENSION pdx, PFILE_OBJECT fop)
	{							// OpenHandle
	PHANDLE_OBJECT hop = (PHANDLE_OBJECT) ExAllocatePool(NonPagedPool, sizeof(HANDLE_OBJECT));
	if (!hop)
		return NULL;
	hop->refcnt = 1;
	hop->pevent = NULL;
	hop->FileObject = fop;
	fop->FsContext = (PVOID) hop;
	ExInterlockedInsertTailList(&pdx->hlist, &hop->link, &pdx->lockHandles);
	return hop;
	}							// OpenHandle

///////////////////////////////////////////////////////////////////////////////

BOOLEAN RegisterEvent(PDEVICE_EXTENSION pdx, PFILE_OBJECT fop, HANDLE hEvent, KPROCESSOR_MODE AccessMode, char eType)
	{							// RegisterEvent
	NTSTATUS status;
	PHANDLE_OBJECT hop = FindHandle(pdx, fop);
	switch (eType)
		{
		case E_ALARM:
			g_alarmpdx=pdx;
			g_alarmfop=fop;
			break;
		case E_LOG:
			g_logpdx=pdx;
			g_logfop=fop;
			break;
		default:
			break;
		}
	if (!hop)
		return FALSE;			// no handle for this file object??
	if (hop->pevent)
		{						// event already registered
		ObDereferenceObject(hop->pevent);
		hop->pevent = NULL;
		}						// event already registered

	status = ObReferenceObjectByHandle(hEvent, EVENT_MODIFY_STATE, *ExEventObjectType,
			AccessMode, (PVOID*) &hop->pevent, NULL);
	ReleaseHandle(hop);
	if (!NT_SUCCESS(status))
		{
		return FALSE;
		}
	return TRUE;
	}							// RegisterEvent

///////////////////////////////////////////////////////////////////////////////

VOID ReleaseHandle(PHANDLE_OBJECT hop)
	{							// ReleaseHandle
	if (InterlockedDecrement(&hop->refcnt) > 0)
		return;
	if (hop->pevent)
		ObDereferenceObject(hop->pevent);
	ExFreePool(hop);
	}							// ReleaseHandle

///////////////////////////////////////////////////////////////////////////////

VOID SignalEvent(PDEVICE_EXTENSION pdx, PFILE_OBJECT fop)
	{							// SignalEvent
	PHANDLE_OBJECT hop = FindHandle(pdx, fop);
	if (hop && hop->pevent)
		KeSetEvent(hop->pevent, 0, FALSE);
	if (hop)
		ReleaseHandle(hop);
	}							// SignalEvent
///////////////////////////////////////////////////////////////////////////////


NTSTATUS CompleteRequest(IN PIRP Irp, IN NTSTATUS status, IN ULONG_PTR info)
	{							// CompleteRequest
	Irp->IoStatus.Status = status;
	Irp->IoStatus.Information = info;
	IoCompleteRequest(Irp, IO_NO_INCREMENT);
	return status;
	}							// CompleteRequest