/*

 * Copyright (c) 1982, 1986, 1993

 *	The Regents of the University of California.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 4. Neither the name of the University nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 *

 *	@(#)tcp.h	8.1 (Berkeley) 6/10/93

 */

#ifndef _NETINET_TCP_H

#define _NETINET_TCP_H	1

#include <sys/cdefs.h>

__BEGIN_DECLS

typedef	unsigned int	tcp_seq;

/*

 * TCP header.

 * Per RFC 793, September, 1981.

 */

struct tcphdr {

	unsigned short	th_sport;	/* source port */

	unsigned short	th_dport;	/* destination port */

	tcp_seq		th_seq;		/* sequence number */

	tcp_seq		th_ack;		/* acknowledgement number */

#if __BYTE_ORDER == __LITTLE_ENDIAN

	unsigned char	th_x2:4,	/* (unused) */

			th_off:4;	/* data offset */

#endif

#if __BYTE_ORDER == __BIG_ENDIAN

	unsigned char	th_off:4,	/* data offset */

			th_x2:4;	/* (unused) */

#endif

	unsigned 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

	unsigned short	th_win;		/* window */

	unsigned short	th_sum;		/* checksum */

	unsigned short	th_urp;		/* urgent pointer */

};

#define	TCPOPT_EOL		0

#define	TCPOPT_NOP		1

#define	TCPOPT_MAXSEG		2

#define TCPOLEN_MAXSEG		4

#define TCPOPT_WINDOW		3

#define TCPOLEN_WINDOW		3

#define TCPOPT_SACK_PERMITTED	4		/* Experimental */

#define TCPOLEN_SACK_PERMITTED	2

#define TCPOPT_SACK		5		/* Experimental */

#define TCPOPT_TIMESTAMP	8

#define TCPOLEN_TIMESTAMP	10

#define TCPOLEN_TSTAMP_APPA	(TCPOLEN_TIMESTAMP+2) /* appendix A */

#define TCPOPT_TSTAMP_HDR	\

    (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)

/*

 * 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 (unscaled) window */

#define TCP_MAX_WINSHIFT	14	/* maximum window shift */

/*

 * 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 */

#define SOL_TCP		6	/* TCP level */

__END_DECLS

#endif /* netinet/tcp.h */