iphlpapi: Implement GetNumberOfInterfaces() on top of nsi.

dlls/iphlpapi/iphlpapi_main.c

@@ -2376,21 +2376,18 @@ DWORD WINAPI GetNetworkParams(PFIXED_INFO pFixedInfo, PULONG pOutBufLen)
  * RETURNS
  *  NO_ERROR on success, ERROR_INVALID_PARAMETER if pdwNumIf is NULL.
  */
-DWORD WINAPI GetNumberOfInterfaces(PDWORD pdwNumIf)
+DWORD WINAPI GetNumberOfInterfaces( DWORD *count )
 {
-  DWORD ret;
+    DWORD err, num;
 
-  TRACE("pdwNumIf %p\n", pdwNumIf);
-  if (!pdwNumIf)
-    ret = ERROR_INVALID_PARAMETER;
-  else {
-    *pdwNumIf = get_interface_indices( FALSE, NULL );
-    ret = NO_ERROR;
-  }
-  TRACE("returning %d\n", ret);
-  return ret;
-}
+    TRACE( "count %p\n", count );
+    if (!count) return ERROR_INVALID_PARAMETER;
 
+    err = NsiEnumerateObjectsAllParameters( 1, 1, &NPI_MS_NDIS_MODULEID, NSI_NDIS_IFINFO_TABLE, NULL, 0,
+                                            NULL, 0, NULL, 0, NULL, 0, &num );
+    *count = err ? 0 : num;
+    return err;
+}
 
 /******************************************************************
  *    GetPerAdapterInfo (IPHLPAPI.@)

dlls/iphlpapi/tests/iphlpapi.c

@@ -138,10 +138,6 @@ static void testGetNumberOfInterfaces(void)
     }
 
     apiReturn = GetNumberOfInterfaces(&numInterfaces);
-    if (apiReturn == ERROR_NOT_SUPPORTED) {
-        skip("GetNumberOfInterfaces is not supported\n");
-        return;
-    }
     ok(apiReturn == NO_ERROR,
        "GetNumberOfInterfaces returned %d, expected 0\n", apiReturn);
 }