/* * 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. * 3. All advertising materials mentioning features or use of this software *    must display the following acknowledgement: *	This product includes software developed by the University of *	California, Berkeley and its contributors. * 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 */typedef	u_int	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) */		th_off:4;		/* data offset */#endif#if BYTE_ORDER == BIG_ENDIAN 	u_char	th_off:4,		/* data offset */		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#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). */#ifndef TCP_NODELAY#define	TCP_NODELAY	0x01	/* don't delay send to coalesce packets */#endif#ifndef TCP_MAXSEG#define	TCP_MAXSEG	0x02	/* set maximum segment size */#endif