func: static void net_l2tpv3_cleanup(NetClientState *nc)
  
  {
  
      NetL2TPV3State *s = DO_UPCAST(NetL2TPV3State, nc, nc);
  
      qemu_purge_queued_packets(nc);
  
      l2tpv3_read_poll(s, false);
  
      l2tpv3_write_poll(s, false);
  
      if (s->fd > 0) {
  
          close(s->fd);
  
      }
  
      destroy_vector(s->msgvec, MAX_L2TPV3_MSGCNT, IOVSIZE);
  
      g_free(s->vec);
  
      g_free(s->header_buf);
  
      g_free(s->dgram_dst);
  
  }
  