struct tcphdr {
uint16_t th_sport; /* source port */
uint16_t th_dport; /* destination port */
tcp_seq th_seq; /* sequence number */
tcp_seq th_ack; /* acknowledgement number */
#ifdef HOST_WORDS_BIGENDIAN
struct tcphdr {
uint16_t th_sport; /* source port */
uint16_t th_dport; /* destination port */
tcp_seq th_seq; /* sequence number */
tcp_seq th_ack; /* acknowledgement number */
#ifdef HOST_WORDS_BIGENDIAN