Comment les clients recherchent et utilisent un point de connexion de service
L’exemple de code suivant montre comment une application cliente recherche un point de connexion de service (SCP) dans le catalogue global. Dans cet exemple de code, l’application cliente a une chaîne GUID codée en dur qui identifie le service. Le programme d’installation du service a stocké la même chaîne GUID que l’une des valeurs de l’attribut de mots clés multi-valeurs SCPs.
Cet exemple se compose de deux routines. La routine GetGC récupère un pointeur IDirectorySearch pour un catalogue global (GC). La routine ScpLocate utilise les méthodes IDirectorySearch pour effectuer une recherche dans le GC.
Le GC contient une réplica partielle de chaque objet de la forêt, mais ne contient pas tous les attributs SCP requis par le client. Tout d’abord, le client doit effectuer une recherche dans le gc pour trouver le SCP et récupérer son nom de domaine. Ensuite, le client utilise le DN du SCP pour établir une liaison à un pointeur IDirectoryObject sur le SCP. Le client appelle ensuite la méthode IDirectoryObject::GetObjectAttributes pour récupérer le reste des attributs.
//***************************************************************************
//
// 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;
}