CreateService in Visual Basic

[Mountie]

I am trying to install and run a service using Visual Basic 6. I receive a handle to the SCM after executing the function OpenSCManager. I then try to install the service by using the function CreateService. At this point the program returns a 0 to indicate that it has an error and has not returned a handle. The code at that point is as follows:

schService = CreateService( _
schOpenSCM, _
lpServiceName, _
lpDisplayName, _
SERVICE_ALL_ACCESS, _
SERVICE_WIN32_OWN_PROCESS, _
SERVICE_AUTO_START, _
SERVICE_ERROR_IGNORE, _
lpszBinaryPathName, _
vbNullString, _
vbNull, _
vbNullString, _
vbNullString, _
vbNullString)

I receive the error message from Err.LastDllError of 87.

Any ideas?

Mountie

 

[chiph]

WinError.h lists 87 as being a Invalid Parameter.

Are you passing the strings as ByVal?

Chip H.

 

[Mountie]

Below is the Function I call from the API. This I got from Microsoft's web site, from the API Viewer in Visual Basic and from Dan Appleman's book.

Declare Function CreateService _
Lib "advapi32.dll" Alias "CreateServiceA" _
(ByVal hSCManager As Long, _
ByVal lpServiceName As String, _
ByVal lpDisplayName As String, _
ByVal dwDesiredAccess As Long, _
ByVal dwServiceType As Long, _
ByVal dwStartType As Long, _
ByVal dwErrorControl As Long, _
ByVal lpBinaryPathName As String, _
ByVal lpLoadOrderGroup As String, _
lpdwTagId As Long, _
ByVal lpDependencies As String, _
ByVal lp As String, _
ByVal lpPassword As String) _
As Long


In the previous message of what is in my own program, the following are the values which I pass for the variables.

schOpenSCM = a long value which is the handle to the SCM, and this looks okay in the Visual Basic Watch Window

lpServiceName = "SecureScreen"
lpDisplayName = "SecureScreen"
lpszBinaryPathName = "c:\\winnt\\system32\\securesc.exe"

 

[chiph]

Why are you doubling up the back-slashes in your path? This is VB, not C.

Chip H.

 

[Mountie]

The following is my function in VB. The whole thing...

Dim lpszBinaryPathName As String, lpServiceName As String, _
lpDisplayName As String
Dim schService As Long ' Handle to CreateService function
Dim schOpenSCM As Long ' Handle to Service Control Manager

lpszBinaryPathName = "C:\WINNT\system32\securesc.exe"
lpServiceName = "SecureScreen"
lpDisplayName = "SecureScreen"

'// Open a handle to the SC Manager database.
schOpenSCM = OpenSCManager( _
vbNullString, _
vbNullString, _
SC_MANAGER_ALL_ACCESS)

schService = CreateService( _
schOpenSCM, _
lpServiceName, _
lpDisplayName, _
SERVICE_ALL_ACCESS, _
SERVICE_WIN32_OWN_PROCESS, _
SERVICE_AUTO_START, _
SERVICE_ERROR_IGNORE, _
lpszBinaryPathName, _
vbNullString, _
vbNull, _
vbNullString, _
vbNullString, _
vbNullString)

If schService = 0 Then
MsgBox "Error in installing Service!" & vbCrLf _
& "Error: " & Err.LastDllError & vbCrLf, _
vbOKOnly, _
"SecureScreen Service"
Else
MsgBox "SecureScreen Service installed.", vbOKOnly, _
"SecureScreen Service"
End If
Call CloseServiceHandle(schService)
Call CloseServiceHandle(schOpenSCM)

-------------------------------------------------------

I have defined the constants I use in the CreateService function as thus:

Public Const SERVICE_ALL_ACCESS As Long = _
(STANDARD_RIGHTS_REQUIRED _
Or SERVICE_QUERY_CONFIG _
Or SERVICE_CHANGE_CONFIG _
Or SERVICE_QUERY_STATUS _
Or SERVICE_ENUMERATE_DEPENDENTS _
Or SERVICE_START _
Or SERVICE_STOP _
Or SERVICE_PAUSE_CONTINUE _
Or SERVICE_INTERROGATE _
Or SERVICE_USER_DEFINED_CONTROL)

Public Const SERVICE_WIN32_OWN_PROCESS As Long = &H10
Public Const SERVICE_AUTO_START As Long = &H2
Public Const SERVICE_ERROR_IGNORE As Long = 0