+ vnet_buffer(p0)->sw_if_index[VLIB_TX] = adj0->rewrite_header.sw_if_index;
+ /* since we are coming out of the L2 world, where the vlib_buffer
+ * union is used for other things, make sure it is clean for
+ * MPLS from now on.
+ */
+ vnet_buffer(p0)->mpls.first = 0;