How to dynamically unload a driver.

Srin_Kumar · January 9, 2003, 4:55pm

I want to load and unload a driver dynamically. For this i am using
ZwLoadDriver and ZwUnloadDriver. This is what was suggested. Now i have
problems with this api. This works fine on Win 2K, but on XP it returns
STATUS_INVALID_DEVICE_REQUEST. In my driver i do not have entry points only
for create close, deviceIoControl and Unload.

What is more required for me to unload this driver? Do i need plug and play
handlers to the driver being unloaded?
Or, Should i need to use any other api instead of ZwUnloadDriver for
unloading the driver?
Or, loading and unloading a driver dynamically is not possible on XP?

any help, any pointers are really appreciated.
Thanks,
Srin.

OSR_Community_User · January 9, 2003, 5:35pm

Hello,

Is there any problem in using this routines: OpenSCManager(…),
CreateService(…),CloseServiceHandle(…) for installing and …,
DeleteService(…), … for unsinstalling? I just noticed that no
one talkes about these routines.

here is a piece of code which is tested and works:

// install the driver:
void CDummyDlg::OnButtonInstall()
{
SC_HANDLE svc_manager = OpenSCManager( NULL, NULL, GENERIC_WRITE);
if( 0 == svc_manager )
{
TRACE(_T(“Error on opening ServiceManager!!!\n”));
return;
}

SC_HANDLE svc = CreateService(svc_manager, SERVICE_NAME,
SERVICE_DISPLAY,
SERVICE_ALL_ACCESS, SERVICE_KERNEL_DRIVER,
SERVICE_DEMAND_START,
SERVICE_ERROR_NORMAL,
SERVICE_PATH,
NULL, NULL, NULL, NULL, NULL);
if( 0 == svc )
{
char buf[200];
FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, 0, GetLastError(), 0,
buf, sizeof(buf), 0);
TRACE(_T(“Error on CreateService : %s\n”), buf);
CloseServiceHandle(svc_manager);
return;
}

if( svc )
CloseServiceHandle(svc);
if( svc_manager )
CloseServiceHandle(svc_manager);
TRACE(_T(“Driver Service Installed!\n”));
}

// Delete the driver
void CDummyDlg::OnButtonDelete()
{
SC_HANDLE svc_manager = OpenSCManager( NULL, NULL, GENERIC_WRITE);
if( 0 == svc_manager )
{
TRACE(_T(“Error on opening ServiceManager!!!\n”));
return;
}

SC_HANDLE svc = OpenService(svc_manager, SERVICE_NAME,
SERVICE_ALL_ACCESS);

if( svc )
{
if( FALSE == ::DeleteService(svc) )
{
char buf[200];
FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, 0, GetLastError(),
0, buf, sizeof(buf), 0);
MessageBox( buf, “Error” );
TRACE(_T(“Error on DeleteService : %s\n”), buf);
CloseServiceHandle(svc);
CloseServiceHandle(svc_manager);
return;
}
else
{
TRACE(_T(“Driver Service Deleted!\n”));
}
}

if( svc )
CloseServiceHandle(svc);
if( svc_manager )
CloseServiceHandle(svc_manager);
}

//Start the Driver
void CDummyDlg::OnButtonStart()
{
SC_HANDLE svc_manager = OpenSCManager( NULL, NULL, GENERIC_EXECUTE);
if( 0 == svc_manager )
{
TRACE(_T(“Error on opening ServiceManager!!!\n”));
return;
}

SC_HANDLE svc = OpenService(svc_manager, SERVICE_NAME,
SERVICE_ALL_ACCESS);
if( svc )
{
if( 0 == StartService(svc, NULL, NULL) )
{
char buf[200];
FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, 0, GetLastError(),
0, buf, sizeof(buf), 0);
TRACE(_T(“Error on StartService : %s\n”), buf);
CloseServiceHandle(svc_manager);
return;
}
}

if( svc )
CloseServiceHandle(svc);
if( svc_manager )
CloseServiceHandle(svc_manager);
TRACE(_T(“Driver Service Started!\n”));
}

//Stop the driver
void CDummyDlg::OnButtonStop()
{
SC_HANDLE svc_manager = OpenSCManager( NULL, NULL, GENERIC_EXECUTE);
if( 0 == svc_manager )
{
TRACE(_T(“Error on opening ServiceManager!!!\n”));
return;
}

SC_HANDLE svc = OpenService(svc_manager, SERVICE_NAME,
SERVICE_ALL_ACCESS);
if( svc )
{
SERVICE_STATUS svc_status;
if( FALSE == ControlService(svc, SERVICE_CONTROL_STOP,
&svc_status) ){
char buf[200];
FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, 0, GetLastError(), 0,
buf, sizeof(buf), 0);
TRACE(_T(“Error on StopService : %s\n”), buf);
CloseServiceHandle(svc_manager);
return;
}
}

if( svc )
CloseServiceHandle(svc);
if( svc_manager )
CloseServiceHandle(svc_manager);
}

Srin_Kumar · January 9, 2003, 8:24pm

I load and unload from another driver, so i can not use there routines.

I found a work around. In driver entry if i or the DriverObject->Flags with
0x02.
the driver gets unloaded.

Thanks any way for listening.

-Srin.

-----Original Message-----
From: Hardwired [mailto:xxxxx@rdslink.ro]
Sent: Thursday, January 09, 2003 2:36 PM
To: NT Developers Interest List
Subject: [ntdev] Re: How to dynamically unload a driver.