udp_write_dgram_header();
elp_write_response();
udp_write_checksum(ETH_HEADER_SIZE + IP_HEADER_SIZE);
netdev_send_end(ETH_HEADER_SIZE + IP_HEADER_SIZE
+ UDP_HEADER_SIZE + len);
udp_write_dgram_header();
elp_write_response();
udp_write_checksum(ETH_HEADER_SIZE + IP_HEADER_SIZE);
netdev_send_end(ETH_HEADER_SIZE + IP_HEADER_SIZE
+ UDP_HEADER_SIZE + len);