-/* checksumming functions (net-checksum.c) */
-uint32_t net_checksum_add(int len, uint8_t *buf);
-uint16_t net_checksum_finish(uint32_t sum);
-uint16_t net_checksum_tcpudp(uint16_t length, uint16_t proto,
- uint8_t *addrs, uint8_t *buf);
-void net_checksum_calculate(uint8_t *data, int length);
-