/* tcp.h 1.21 82/01/18 */
* Per RFC 793, September, 1981.
u_short th_sport
; /* source port */
u_short th_dport
; /* destination port */
tcp_seq th_seq
; /* sequence number */
tcp_seq th_ack
; /* acknowledgement number */
th_off
:4; /* data offset */
u_short th_win
; /* window */
u_short th_sum
; /* checksum */
u_short th_urp
; /* urgent pointer */
* True out-of-band as value added option.
* Advertise willingness with TCPOPT_WILOOB in
* initial segment. If peer is willing, will receive
* such also. Then can send TCPOPT_OOBDATA whenever oob data
* exists; peer should ack with TCPOPT_OOBACK in segment.
#define TCPOPT_WILLOOB 64 /* bytes: 64, 2 */
#define TCPOPT_OOBDATA 65 /* bytes: 65, 8, seq#, data, markseq */
#define TCPOPT_OOBACK 66 /* bytes: 66, 3, ack# */