#ifndef ETHERLIB_TCP_UDP_COMMON_H
#define ETHERLIB_TCP_UDP_COMMON_H

#include <stdint.h>

typedef struct {
    uint32_t sourceIpAddr;
    uint32_t destIpAddr;
    uint8_t zero;
    uint8_t protocol;
    uint16_t udpLength;
} IPv4PseudoHeader;

/**
 * Calculate TCP or UDP checksum.
 * @param pseudoHeader pointer to IPv4 pseudo-header
 * @param hdr pointer to data
 * @param size size of data
 * @return checksum
 */
uint16_t tcp_udp_checksum(const IPv4PseudoHeader *pseudoHeader, const uint8_t * hdr, uint32_t size);

#endif //ETHERLIB_TCP_UDP_COMMON_H