clib_memcpy_fast (b->data, d0 + data_offset, bytes_this_chunk);
vnet_buffer (b)->sw_if_index[VLIB_RX] = s->sw_if_index[VLIB_RX];
vnet_buffer (b)->sw_if_index[VLIB_TX] = s->sw_if_index[VLIB_TX];
clib_memcpy_fast (b->data, d0 + data_offset, bytes_this_chunk);
vnet_buffer (b)->sw_if_index[VLIB_RX] = s->sw_if_index[VLIB_RX];
vnet_buffer (b)->sw_if_index[VLIB_TX] = s->sw_if_index[VLIB_TX];