#ifndef NETINET_TCP_H
#define NETINET_TCP_H \
       "$Id: tcp.h,v 1.1.1.1 2001/11/26 22:21:17 tboeckel Exp $"
/*
 *      TCP header
 *
 *      Copyright © 1994 AmiTCP/IP Group,
 *                       Network Solutions Development, Inc.
 *                       All rights reserved.
 */

typedef	u_long	tcp_seq;

/*
 * TCP header.
 * Per RFC 793, September, 1981.
 */
struct tcphdr {
	u_short	th_sport;		/* source port */
	u_short	th_dport;		/* destination port */
	tcp_seq	th_seq;			/* sequence number */
	tcp_seq	th_ack;			/* acknowledgement number */
#if BYTE_ORDER == LITTLE_ENDIAN 
	u_char	th_x2:4;		/* (unused) */
	u_char	th_off:4;		/* data offset */
#endif
#if BYTE_ORDER == BIG_ENDIAN 
	u_char	th_off:4;		/* data offset */
	u_char	th_x2:4;		/* (unused) */
#endif
	u_char	th_flags;
#define	TH_FIN	0x01
#define	TH_SYN	0x02
#define	TH_RST	0x04
#define	TH_PUSH	0x08
#define	TH_ACK	0x10
#define	TH_URG	0x20
	u_short	th_win;			/* window */
	u_short	th_sum;			/* checksum */
	u_short	th_urp;			/* urgent pointer */
};

#define	TCPOPT_EOL	0
#define	TCPOPT_NOP	1
#define	TCPOPT_MAXSEG	2

/*
 * Default maximum segment size for TCP.
 * With an IP MSS of 576, this is 536,
 * but 512 is probably more convenient.
 * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)).
 */
#define	TCP_MSS	512

#define	TCP_MAXWIN	65535		/* largest value for window */

/*
 * User-settable options (used with setsockopt).
 */
#define	TCP_NODELAY	0x01	/* don't delay send to coalesce packets */
#define	TCP_MAXSEG	0x02	/* set maximum segment size */

#endif /* !NETINET_TCP_H */