+/** Determine the next L2 node based on the output feature bitmap */
+static_always_inline void
+l2_output_dispatch (vlib_buffer_t * b0, vlib_node_runtime_t * node,
+ u32 * cached_sw_if_index, u32 * cached_next_index,
+ u32 sw_if_index, u32 feature_bitmap, u32 * next0)
+{
+ /*
+ * The output feature bitmap always have at least the L2 output bit set
+ * for a normal L2 interface (or 0 if the interface is changed from L2
+ * to L3 mode). So if the feature bitmap is 0 or just have L2 output bits set,
+ * we know there is no more feature and will just output packets on interface.
+ * Otherwise, get the index of the next feature node.
+ */
+ if (PREDICT_FALSE ((feature_bitmap & ~L2OUTPUT_FEAT_OUTPUT) != 0))
+ {
+ /* Save bitmap for the next feature graph nodes */
+ vnet_buffer (b0)->l2.feature_bitmap = feature_bitmap;
+
+ /* Determine the next node */
+ *next0 =
+ feat_bitmap_get_next_node_index (l2output_main.l2_out_feat_next,
+ feature_bitmap);
+ }
+ else
+ {
+ /*
+ * There are no features. Send packet to TX node for sw_if_index0
+ * This is a little tricky in that the output interface next node indexes
+ * are not precomputed at init time.
+ */
+
+ if (sw_if_index == *cached_sw_if_index)
+ {
+ /* We hit in the one-entry cache. Use it. */
+ *next0 = *cached_next_index;
+ }
+ else
+ {
+ /* Look up the output TX node for the sw_if_index */
+ *next0 = vec_elt (l2output_main.output_node_index_vec, sw_if_index);
+
+ if (PREDICT_FALSE (*next0 == L2OUTPUT_NEXT_DROP))
+ b0->error = node->errors[L2OUTPUT_ERROR_MAPPING_DROP];
+
+ /* Update the one-entry cache */
+ *cached_sw_if_index = sw_if_index;
+ *cached_next_index = *next0;
+ }
+ }
+}
+