+int
+vnet_sw_interface_is_nbma (vnet_main_t * vnm, u32 sw_if_index)
+{
+ vnet_hw_interface_t *hw = vnet_get_sup_hw_interface (vnm, sw_if_index);
+ vnet_hw_interface_class_t *hc =
+ vnet_get_hw_interface_class (vnm, hw->hw_class_index);
+
+ return (hc->flags & VNET_HW_INTERFACE_CLASS_FLAG_NBMA);
+}
+
+clib_error_t *
+vnet_sw_interface_supports_addressing (vnet_main_t *vnm, u32 sw_if_index)
+{
+ if (sw_if_index == 0)
+ {
+ return clib_error_create (
+ "local0 interface doesn't support IP addressing");
+ }
+
+ if (vnet_sw_interface_is_sub (vnm, sw_if_index))
+ {
+ vnet_sw_interface_t *si;
+ si = vnet_get_sw_interface_or_null (vnm, sw_if_index);
+ if (si && si->type == VNET_SW_INTERFACE_TYPE_SUB &&
+ si->sub.eth.flags.exact_match == 0)
+ {
+ return clib_error_create (
+ "sub-interface without exact-match doesn't support IP addressing");
+ }
+ }
+ return NULL;
+}
+
+u32
+vnet_register_device_class (vlib_main_t *vm, vnet_device_class_t *c)
+{
+ vnet_main_t *vnm = vnet_get_main ();
+ vnet_interface_main_t *im = &vnm->interface_main;
+ c->index = vec_len (im->device_classes);
+ hash_set_mem (im->device_class_by_name, c->name, c->index);
+
+ /* to avoid confusion, please remove ".tx_function" statement
+ from VNET_DEVICE_CLASS() if using function candidates */
+ ASSERT (c->tx_fn_registrations == 0 || c->tx_function == 0);
+
+ if (c->tx_fn_registrations)
+ c->tx_function =
+ vlib_node_get_preferred_node_fn_variant (vm, c->tx_fn_registrations);
+
+ vec_add1 (im->device_classes, c[0]);
+ return c->index;
+}
+