1  /*
       2   * Copyright (c) 1982, 1986, 1993
       3   *	The Regents of the University of California.  All rights reserved.
       4   *
       5   * Redistribution and use in source and binary forms, with or without
       6   * modification, are permitted provided that the following conditions
       7   * are met:
       8   * 1. Redistributions of source code must retain the above copyright
       9   *    notice, this list of conditions and the following disclaimer.
      10   * 2. Redistributions in binary form must reproduce the above copyright
      11   *    notice, this list of conditions and the following disclaimer in the
      12   *    documentation and/or other materials provided with the distribution.
      13   * 4. Neither the name of the University nor the names of its contributors
      14   *    may be used to endorse or promote products derived from this software
      15   *    without specific prior written permission.
      16   *
      17   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
      18   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
      19   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
      20   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
      21   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
      22   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
      23   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
      24   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
      25   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
      26   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
      27   * SUCH DAMAGE.
      28   *
      29   *	@(#)tcp.h	8.1 (Berkeley) 6/10/93
      30   */
      31  
      32  #ifndef _NETINET_TCP_H
      33  
      34  #define _NETINET_TCP_H	1
      35  #include <sys/cdefs.h>
      36  
      37  
      38  __BEGIN_DECLS
      39  
      40  typedef	unsigned int	tcp_seq;
      41  /*
      42   * TCP header.
      43   * Per RFC 793, September, 1981.
      44   */
      45  struct tcphdr {
      46  	unsigned short	th_sport;	/* source port */
      47  	unsigned short	th_dport;	/* destination port */
      48  	tcp_seq		th_seq;		/* sequence number */
      49  	tcp_seq		th_ack;		/* acknowledgement number */
      50  #if __BYTE_ORDER == __LITTLE_ENDIAN
      51  	unsigned char	th_x2:4,	/* (unused) */
      52  			th_off:4;	/* data offset */
      53  #endif
      54  #if __BYTE_ORDER == __BIG_ENDIAN
      55  	unsigned char	th_off:4,	/* data offset */
      56  			th_x2:4;	/* (unused) */
      57  #endif
      58  	unsigned char	th_flags;
      59  #define	TH_FIN	0x01
      60  #define	TH_SYN	0x02
      61  #define	TH_RST	0x04
      62  #define	TH_PUSH	0x08
      63  #define	TH_ACK	0x10
      64  #define	TH_URG	0x20
      65  	unsigned short	th_win;		/* window */
      66  	unsigned short	th_sum;		/* checksum */
      67  	unsigned short	th_urp;		/* urgent pointer */
      68  };
      69  
      70  #define	TCPOPT_EOL		0
      71  #define	TCPOPT_NOP		1
      72  #define	TCPOPT_MAXSEG		2
      73  #define TCPOLEN_MAXSEG		4
      74  #define TCPOPT_WINDOW		3
      75  #define TCPOLEN_WINDOW		3
      76  #define TCPOPT_SACK_PERMITTED	4		/* Experimental */
      77  #define TCPOLEN_SACK_PERMITTED	2
      78  #define TCPOPT_SACK		5		/* Experimental */
      79  #define TCPOPT_TIMESTAMP	8
      80  #define TCPOLEN_TIMESTAMP	10
      81  #define TCPOLEN_TSTAMP_APPA	(TCPOLEN_TIMESTAMP+2) /* appendix A */
      82  
      83  #define TCPOPT_TSTAMP_HDR	\
      84      (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)
      85  
      86  /*
      87   * Default maximum segment size for TCP.
      88   * With an IP MSS of 576, this is 536,
      89   * but 512 is probably more convenient.
      90   * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)).
      91   */
      92  #define	TCP_MSS	512
      93  
      94  #define	TCP_MAXWIN	65535	/* largest value for (unscaled) window */
      95  
      96  #define TCP_MAX_WINSHIFT	14	/* maximum window shift */
      97  
      98  /*
      99   * User-settable options (used with setsockopt).
     100   */
     101  #define	TCP_NODELAY	0x01	/* don't delay send to coalesce packets */
     102  #define	TCP_MAXSEG	0x02	/* set maximum segment size */
     103  
     104  #define SOL_TCP		6	/* TCP level */
     105  
     106  __END_DECLS
     107  
     108  #endif /* netinet/tcp.h */