cpgpdiskdrvios.cpp

vc环境下的pgp源码

//////////////////////////////////////////////////////////////////////////////
// CPGPdiskDrvIos.cpp
//
// Contains the AEP and IOS request handling routines for the driver.
//////////////////////////////////////////////////////////////////////////////

// $Id: CPGPdiskDrvIos.cpp,v 1.9 1999/02/13 04:24:34 nryan Exp $

// Copyright (C) 1998 by Network Associates, Inc.
// All rights reserved.

#include <vtoolscp.h>

#include "Required.h"
#include "CPGPdiskDrvIos.h"
#include "GenericCallback.h"
#include "Globals.h"
#include "IopProcessor.h"
#include "Volume.h"


////////////
// Constants
////////////


const PGPUInt32	kDefaultIopTimeout		= 15;
const PGPUInt32	kContextToggleSeconds	= 5;
const PGPUInt32	kContextVerifySeconds	= 5;


////////////////////////////////
// AEP message handling routines
////////////////////////////////

// The AepInitialize packet is recieved once during IOS registration for the
// driver. It is responsible for creating a DDB for the driver (which the IOS
// requires).

PGPUInt16 
CPGPdiskDrv::AepInitialize(PAEP_bi_init pAep)
{
	mTheDDB = IspCreateDdb(sizeof(IOSDDB), NULL);

	if (IsntNull(mTheDDB))
	{
		mLoadGroupNum = pAep->AEP_bi_i_hdr.AEP_lgn;
		return AEP_SUCCESS;
	}
	else
	{
		return AEP_FAILURE;
	}
}

// AepDeviceInquiry is called a number of times during IOS registration. We
// don't allocate any DCBs at this time so we return AEP_NO_MORE_DEVICES.

PGPUInt16 
CPGPdiskDrv::AepDeviceInquiry(PAEP_inquiry_device pAEP)
{
	return AEP_NO_MORE_DEVICES;
}

// AepIopTimeout is called whenever a timeout is issued on an IOP. If it is
// one of ours, we just reset the timer (assuming that it's just waiting in
// our queue).

PGPUInt16 
CPGPdiskDrv::AepIopTimeout(PAEP_iop_timeout_occurred pAep)
{
	PGPUInt8	drive;
	PIOP		pIop;
	PIOR		pIor;
	PGPdisk		*pPGD	= NULL;

	pIop = (PIOP) pAep->AEP_i_t_o_iop;
	pgpAssertAddrValid(pIop, IOP);

	pIor = &pIop->IOP_ior;
	pgpAssertAddrValid(pIor, IOR);

	// First see if this request is coming FROM a PGPdisk.
	if (pIor->IOR_private_client == kPGPdiskIopMagic)
		DebugOut("PGPdisk: I/O from PGPdisk to a host drive timed-out.");

	// Now see if this request is going TO a PGPdisk.
	drive = pIop->IOP_ior.IOR_vol_designtr;

	if (drive < kMaxDrives)
	{
		pPGD = mPGPdisks.FindPGPdisk(drive);
	}

	// If so, reset the timer.
	if (pPGD)
	{
		DebugOut("PGPdisk: Resetting timed-out I/O to a PGPdisk.");

		pIop->IOP_timer = pIop->IOP_timer_orig;
		return AEP_SUCCESS;
	}
	else
	{
		return AEP_FAILURE;
	}
}

// AepOneSecondCallback performs certain operations that must occur each
// second at a safe time.

VOID 
__stdcall 
CPGPdiskDrv::AepOneSecondCallback(
	VMHANDLE		hVM, 
	THREADHANDLE	hThread, 
	PVOID			Refdata, 
	PCLIENT_STRUCT	pRegs)
{
	static PGPUInt32	lastToggleTime	= 0;
	static PGPUInt32	lastVerifyTime	= 0;

	// Increase the inactivity timer.
	Driver->mSecondsInactive++;
	
	// If we are in 'unmount all mode', keep trying to unmount all until we
	// succeed.

	if (Driver->mUnmountAllMode)
	{
		DualErr derr;

		derr = Driver->UnmountAllPGPdisks(FALSE);
		Driver->mUnmountAllMode = !derr.IsntError();
	}

	// Flip contexts on all PGPdisks if this is the time to do so.
	if (lastToggleTime++ > kContextToggleSeconds)
	{
		lastToggleTime = 0;
		Driver->mPGPdisks.FlipAllContexts();
	}

	// Verify cipher contexts on all PGPdisks if this is the time to do so.
	if (lastVerifyTime++ > kContextVerifySeconds)
	{
		lastVerifyTime = 0;
		Driver->mPGPdisks.ValidateAllCipherContexts();
	}

	// If it is time to auto-unmount, we do so. We schedule the unmounts to
	// occur during an appy-time callback.

	if ((Driver->mAutoUnmount) && 
		(Driver->mSecondsInactive > Driver->mUnmountTimeout*60))
	{
		Driver->mSecondsInactive = 0;
		Driver->UnmountAllPGPdisks();
	}
}

// AepOneSecond is called every one second. We schedule a callback to perform
// necessary tasks at a safe time.

PGPUInt16                                                                                    
CPGPdiskDrv::AepOneSecond()
{
	static RestrictedEvent_THUNK callbackThunk;

	Call_Restricted_Event(0, NULL, PEF_WAIT_NOT_CRIT, NULL, 
		AepOneSecondCallback, 0, &callbackThunk);

	return AEP_SUCCESS;
}

// PGPDISK_Aer is the asynchronous event handler for the driver. It is called
// to handle AEP packets sent by the system that represent various events and
// occurences, most importantly the sequence of events that result in
// initialization of the DCBs needed for volume mounting.

VOID 
__cdecl 
CPGPdiskDrv::PGPDISK_Aer(PAEP pAep)
{
	pgpAssertAddrValid(pAep, AEP);

	if ((pAep->AEP_func != AEP_HALF_SEC) && 
		(pAep->AEP_func != AEP_1_SEC))
	{
		DebugOut("PGPdisk: %s", Driver->GetAEPFunctionName(pAep->AEP_func));
	}

	switch (pAep->AEP_func)
	{
	case AEP_INITIALIZE:			// recieved during IOS registration
		pAep->AEP_result = Driver->AepInitialize((PAEP_bi_init) pAep);
		break;

	case AEP_DEVICE_INQUIRY:		// rcvd to determine how many DCBs we want
		pAep->AEP_result = Driver->AepDeviceInquiry((PAEP_inquiry_device) 
			pAep);
		break;

	case AEP_IOP_TIMEOUT:			// rcvd to notify driver of IOP timeout
		pAep->AEP_result = Driver->AepIopTimeout((PAEP_iop_timeout_occurred) 
			pAep);
		break;

	case AEP_1_SEC:					// notify us every half second
		pAep->AEP_result = Driver->AepOneSecond();

	default:						// default by returning success
		pAep->AEP_result = AEP_SUCCESS;
		break;
	}
}


////////////////////////////////
// I/O request handling routines
////////////////////////////////

// Due to an incredibly obscure interaction involving MSVC an optimization and
// an IOS bug (it passes IOP address on the stack, expected that value to be
// unaltered when the function returns - within local parameter storage no
// less!), IOS request handlers have to be called using a stub function.

VOID 
__cdecl 
CPGPdiskDrv::PGPDISK_RequestHandlerStub(PIOP pIop)
{
	PGPDISK_RequestHandler(pIop);
}

// PGPDISK_RequestHandler passes the IOP to our IopProcessor for - you
// guessed it - processing.

void  
CPGPdiskDrv::PGPDISK_RequestHandler(PIOP pIop)
{
	Driver->mIopProcessor.ProcessIop(pIop);
}