Updating a Service Connection Point

The following code example shows how to update a service connection point. This code is typically executed by a service when it starts.

This example retrieves the SCP's GUID binding string that the service installer cached in the registry. It uses this string to bind to an IDirectoryObject pointer on the SCP object, and then calls the IDirectoryObject::GetObjectAttributes method to get the serviceDNSName and serviceBindingInformation attributes of the SCP. Be aware that your service may require to verify and update additional attributes.

The code compares the serviceDNSName value to the DNS name returned by the GetComputerNameEx function. It also compares the service's current port number to the port number stored in the serviceBindingInformation attribute. If either of these values have changed, the code calls the IDirectoryObject::SetObjectAttributes method to update the SCP attributes.


DWORD
ScpUpdate(USHORT usPort)
{
DWORD   dwStat, dwType, dwLen;
BOOL    bUpdate=FALSE;

HKEY    hReg;

TCHAR   szAdsPath[MAX_PATH];
TCHAR   szServer[MAX_PATH];
TCHAR   szPort[8];
TCHAR   *pszAttrs[]={
    {TEXT("serviceDNSName")},
    {TEXT("serviceBindingInformation")},
};

HRESULT             hr;
IDirectoryObject    *pObj;
DWORD               dwAttrs;
int                 i;

PADS_ATTR_INFO  pAttribs;
ADSVALUE        dnsname,binding;

ADS_ATTR_INFO   Attribs[]={
    {TEXT("serviceDnsName"),ADS_ATTR_UPDATE,ADSTYPE_CASE_IGNORE_STRING,&dnsname,1},
    {TEXT("serviceBindingInformation"),ADS_ATTR_UPDATE,ADSTYPE_CASE_IGNORE_STRING,&binding,1},
};

// Open the service registry key.
dwStat = RegOpenKeyEx(
        HKEY_LOCAL_MACHINE,
        TEXT("Software\\Microsoft\\Windows 2000 Auth-O-Matic"),
        0,
        KEY_QUERY_VALUE,
        &hReg);
if (dwStat != NO_ERROR) 
{
    ReportServiceError("RegOpenKeyEx failed", dwStat);
    return dwStat;
}

// Get the GUID binding string used to bind to the service SCP.
dwLen = sizeof(szAdsPath);
dwStat = RegQueryValueEx(hReg, TEXT("GUIDBindingString"), 0, &dwType, 
                             (LPBYTE)szAdsPath, &dwLen);
if (dwStat != NO_ERROR) {
    ReportServiceError("RegQueryValueEx failed", dwStat);
    return dwStat;
}

RegCloseKey(hReg);

// Bind to the SCP.
hr = ADsGetObject(szAdsPath, IID_IDirectoryObject, (void **)&pObj);
if (FAILED(hr)) 
{
    char szMsg1[1024];
    sprintf_s(szMsg1, 
            "ADsGetObject failed to bind to GUID (bind string: %S): ", 
            szAdsPath);
    ReportServiceError(szMsg1, hr);
    if(pObj)
    {
        pObj->Release();
    }
    return dwStat;
}

// Retrieve attributes from the SCP.
hr = pObj->GetObjectAttributes(pszAttrs, 2, &pAttribs, &dwAttrs);
if (FAILED(hr)) {
    ReportServiceError("GetObjectAttributes failed", hr);
    pObj->Release();
    return hr;
}

// Get the current port and DNS name of the host server.
_stprintf_s(szPort,TEXT("%d"),usPort);
dwLen = sizeof(szServer);
if (!GetComputerNameEx(ComputerNameDnsFullyQualified,szServer,&dwLen)) 
{
    pObj->Release();
    return GetLastError();
}

// Compare the current DNS name and port to the values retrieved from
// the SCP. Update the SCP only if nothing has changed.
for (i=0; i<(LONG)dwAttrs; i++) 
{
    if ((_tcscmp(TEXT("serviceDNSName"),pAttribs[i].pszAttrName)==0) &&
        (pAttribs[i].dwADsType == ADSTYPE_CASE_IGNORE_STRING))
    {
        if (_tcscmp(szServer,pAttribs[i].pADsValues->CaseIgnoreString) != 0)
        {
            ReportServiceError("serviceDNSName being updated", 0);
            bUpdate = TRUE;
        }
        else
            ReportServiceError("serviceDNSName okay", 0);

    }

    if ((_tcscmp(TEXT("serviceBindingInformation"),pAttribs[i].pszAttrName)==0) &&
        (pAttribs[i].dwADsType == ADSTYPE_CASE_IGNORE_STRING))
    {
        if (_tcscmp(szPort,pAttribs[i].pADsValues->CaseIgnoreString) != 0)
        {
            ReportServiceError("serviceBindingInformation being updated", 0);
            bUpdate = TRUE;
        }
        else
            ReportServiceError("serviceBindingInformation okay", 0);
    }
}

FreeADsMem(pAttribs);

// The binding data or server name have changed, 
// so update the SCP values.
if (bUpdate)
{
    dnsname.dwType              = ADSTYPE_CASE_IGNORE_STRING;
    dnsname.CaseIgnoreString    = szServer;
    binding.dwType              = ADSTYPE_CASE_IGNORE_STRING;
    binding.CaseIgnoreString    = szPort;
    hr = pObj->SetObjectAttributes(Attribs, 2, &dwAttrs);
    if (FAILED(hr)) 
    {
        ReportServiceError("ScpUpdate: Failed to set SCP values.", hr);
        pObj->Release();
        return hr;
    }
}

pObj->Release();

return dwStat;
}

 

 

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