Cómo buscan y usan un punto de conexión de servicio los clientes
En el ejemplo de código siguiente se muestra cómo una aplicación cliente busca un punto de conexión de servicio (SCP) en el catálogo global. En este ejemplo de código, la aplicación cliente tiene una cadena GUID codificada de forma rígida que identifica el servicio. El instalador de servicio almacenó la misma cadena GUID que uno de los valores del atributo de palabras clave de varios valores de SCPs.
Este ejemplo consta de dos rutinas. La rutina GetGC recupera un puntero IDirectorySearch para un catálogo global (GC). La rutina ScpLocate usa los métodos IDirectorySearch para buscar en el GC.
El GC contiene una réplica parcial de todos los objetos del bosque, pero no contiene todos los atributos SCP que requiere el cliente. En primer lugar, el cliente debe buscar en el GC para buscar el SCP y recuperar su DN. A continuación, el cliente usa el DN de SCP para enlazar a un puntero IDirectoryObject en el SCP. A continuación, el cliente llama al método IDirectoryObject::GetObjectAttributes para recuperar el resto de los atributos.
//***************************************************************************
//
// ScpLocate()
//
// All strings returned by ScpLocate must be freed by the caller using
// FreeADsStr after it is finished using them.
//
//***************************************************************************
DWORD ScpLocate (
LPWSTR *ppszDN, // Returns distinguished name of SCP.
LPWSTR *ppszServiceDNSName, // Returns service DNS name.
LPWSTR *ppszServiceDNSNameType, // Returns type of DNS name.
LPWSTR *ppszClass, // Returns name of service class.
USHORT *pusPort) // Returns service port.
{
HRESULT hr;
IDirectoryObject *pSCP = NULL;
ADS_ATTR_INFO *pPropEntries = NULL;
IDirectorySearch *pSearch = NULL;
ADS_SEARCH_HANDLE hSearch = NULL;
// Get an IDirectorySearch pointer for the Global Catalog.
hr = GetGCSearch(&pSearch);
if (FAILED(hr))
{
fprintf(stderr,"GetGC failed 0x%x",hr);
goto Cleanup;
}
// Set up a deep search.
// Thousands of objects are not expected in this example, therefore
// query for 1000 rows per page.
ADS_SEARCHPREF_INFO SearchPref[2];
DWORD dwPref = sizeof(SearchPref)/sizeof(ADS_SEARCHPREF_INFO);
SearchPref[0].dwSearchPref = ADS_SEARCHPREF_SEARCH_SCOPE;
SearchPref[0].vValue.dwType = ADSTYPE_INTEGER;
SearchPref[0].vValue.Integer = ADS_SCOPE_SUBTREE;
SearchPref[1].dwSearchPref = ADS_SEARCHPREF_PAGESIZE;
SearchPref[1].vValue.dwType = ADSTYPE_INTEGER;
SearchPref[1].vValue.Integer = 1000;
hr = pSearch->SetSearchPreference(SearchPref, dwPref);
fprintf (stderr, "SetSearchPreference: 0x%x\n", hr);
if (FAILED(hr))
{
fprintf (stderr, "Failed to set search prefs: hr:0x%x\n", hr);
goto Cleanup;
}
// Execute the search. From the GC get the distinguished name
// of the SCP. Use the DN to bind to the SCP and get the other
// properties.
LPWSTR rgszDN[] = {L"distinguishedName"};
// Search for a match of the product GUID.
hr = pSearch->ExecuteSearch( L"keywords=A762885A-AA44-11d2-81F1-00C04FB9624E",
rgszDN,
1,
&hSearch);
fprintf (stderr, "ExecuteSearch: 0x%x\n", hr);
if (FAILED(hr))
{
fprintf (stderr, "ExecuteSearch failed: hr:0x%x\n", hr);
goto Cleanup;
}
// Loop through the results. Each row should be an instance of the
// service identified by the product GUID.
// Add logic to select from multiple service instances.
hr = pSearch->GetNextRow(hSearch);
if (SUCCEEDED(hr) && hr !=S_ADS_NOMORE_ROWS)
{
ADS_SEARCH_COLUMN Col;
hr = pSearch->GetColumn(hSearch, L"distinguishedName", &Col);
*ppszDN = AllocADsStr(Col.pADsValues->CaseIgnoreString);
pSearch->FreeColumn(&Col);
hr = pSearch->GetNextRow(hSearch);
}
// Bind to the DN to get the other properties.
LPWSTR lpszLDAPPrefix = L"LDAP://";
DWORD dwSCPPathLength = wcslen(lpszLDAPPrefix) + wcslen(*ppszDN) + 1;
LPWSTR pwszSCPPath = new WCHAR[dwSCPPathLength];
if(pwszSCPPath)
{
wcscpy_s(pwszSCPPath, lpszLDAPPrefix);
wcscat_s(pwszSCPPath, *ppszDN);
}
else
{
fprintf(stderr,"Failed to allocate a buffer");
goto Cleanup;
}
hr = ADsGetObject( pwszSCPPath,
IID_IDirectoryObject,
(void**)&pSCP);
// Free the string buffer
delete pwszSCPPath;
if (SUCCEEDED(hr))
{
// Properties to retrieve from the SCP object.
LPWSTR rgszAttribs[]=
{
{L"serviceClassName"},
{L"serviceDNSName"},
{L"serviceDNSNameType"},
{L"serviceBindingInformation"}
};
DWORD dwAttrs = sizeof(rgszAttribs)/sizeof(LPWSTR);
DWORD dwNumAttrGot;
hr = pSCP->GetObjectAttributes( rgszAttribs,
dwAttrs,
&pPropEntries,
&dwNumAttrGot);
if(FAILED(hr))
{
fprintf (stderr, "GetObjectAttributes Failed. hr:0x%x\n", hr);
goto Cleanup;
}
// Loop through the entries returned by GetObjectAttributes
// and save the values in the appropriate buffers.
for (int i = 0; i < (LONG)dwAttrs; i++)
{
if ((wcscmp(L"serviceDNSName", pPropEntries[i].pszAttrName)==0) &&
(pPropEntries[i].dwADsType == ADSTYPE_CASE_IGNORE_STRING))
{
*ppszServiceDNSName = AllocADsStr(pPropEntries[i].pADsValues->CaseIgnoreString);
}
if ((wcscmp(L"serviceDNSNameType", pPropEntries[i].pszAttrName)==0) &&
(pPropEntries[i].dwADsType == ADSTYPE_CASE_IGNORE_STRING))
{
*ppszServiceDNSNameType = AllocADsStr(pPropEntries[i].pADsValues->CaseIgnoreString);
}
if ((wcscmp(L"serviceClassName", pPropEntries[i].pszAttrName)==0) &&
(pPropEntries[i].dwADsType == ADSTYPE_CASE_IGNORE_STRING))
{
*ppszClass = AllocADsStr(pPropEntries[i].pADsValues->CaseIgnoreString);
}
if ((wcscmp(L"serviceBindingInformation", pPropEntries[i].pszAttrName)==0) &&
(pPropEntries[i].dwADsType == ADSTYPE_CASE_IGNORE_STRING))
{
*pusPort=(USHORT)_wtoi(pPropEntries[i].pADsValues->CaseIgnoreString);
}
}
}
Cleanup:
if (pSCP)
{
pSCP->Release();
pSCP = NULL;
}
if (pPropEntries)
{
FreeADsMem(pPropEntries);
pPropEntries = NULL;
}
if (pSearch)
{
if (hSearch)
{
pSearch->CloseSearchHandle(hSearch);
hSearch = NULL;
}
pSearch->Release();
pSearch = NULL;
}
return hr;
}
//***************************************************************************
//
// GetGCSearch()
//
// Retrieves an IDirectorySearch pointer for a Global Catalog (GC)
//
//***************************************************************************
HRESULT GetGCSearch(IDirectorySearch **ppDS)
{
HRESULT hr;
IEnumVARIANT *pEnum = NULL;
IADsContainer *pCont = NULL;
IDispatch *pDisp = NULL;
VARIANT var;
ULONG lFetch;
*ppDS = NULL;
// Bind to the GC: namespace container object. The true GC DN
// is a single immediate child of the GC: namespace, which must
// be obtained using enumeration.
hr = ADsOpenObject( L"GC:",
NULL,
NULL,
ADS_SECURE_AUTHENTICATION, // Use Secure Authentication.
IID_IADsContainer,
(void**)&pCont);
if (FAILED(hr))
{
_tprintf(TEXT("ADsOpenObject failed: 0x%x\n"), hr);
goto cleanup;
}
// Get an enumeration interface for the GC container.
hr = ADsBuildEnumerator(pCont, &pEnum);
if (FAILED(hr))
{
_tprintf(TEXT("ADsBuildEnumerator failed: 0x%x\n"), hr);
goto cleanup;
}
// Now enumerate. There is only one child of the GC: object.
hr = ADsEnumerateNext(pEnum, 1, &var, &lFetch);
if (FAILED(hr))
{
_tprintf(TEXT("ADsEnumerateNext failed: 0x%x\n"), hr);
goto cleanup;
}
if ((hr == S_OK) && (lFetch == 1))
{
pDisp = V_DISPATCH(&var);
hr = pDisp->QueryInterface( IID_IDirectorySearch, (void**)ppDS);
}
cleanup:
if (pEnum)
{
ADsFreeEnumerator(pEnum);
pEnum = NULL;
}
if (pCont)
{
pCont->Release();
pCont = NULL;
}
if (pDisp)
{
pDisp->Release();
pDisp = NULL;
}
return hr;
}