sys/netinet/tcp.h

   1 /*      $NetBSD: tcp.h,v 1.27 2007/08/02 02:42:40 rmind Exp $   */
   2
   3 /*
   4  * Copyright (c) 1982, 1986, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  *      @(#)tcp.h       8.1 (Berkeley) 6/10/93
  32  */
  33
  34 #ifndef _NETINET_TCP_H_
  35 #define _NETINET_TCP_H_
  36
  37 #include <sys/featuretest.h>
  38
  39 #if defined(_NETBSD_SOURCE)
  40
  41 typedef u_int32_t tcp_seq;
  42 /*
  43  * TCP header.
  44  * Per RFC 793, September, 1981.
  45  * Updated by RFC 3168, September, 2001.
  46  */
  47 struct tcphdr {
  48         u_int16_t th_sport;             /* source port */
  49         u_int16_t th_dport;             /* destination port */
  50         tcp_seq   th_seq;               /* sequence number */
  51         tcp_seq   th_ack;               /* acknowledgement number */
  52 #if BYTE_ORDER == LITTLE_ENDIAN
  53         /*LINTED non-portable bitfields*/
  54         u_int8_t  th_x2:4,              /* (unused) */
  55                   th_off:4;             /* data offset */
  56 #endif
  57 #if BYTE_ORDER == BIG_ENDIAN
  58         /*LINTED non-portable bitfields*/
  59         u_int8_t  th_off:4,             /* data offset */
  60                   th_x2:4;              /* (unused) */
  61 #endif
  62         u_int8_t  th_flags;
  63 #define TH_FIN    0x01
  64 #define TH_SYN    0x02
  65 #define TH_RST    0x04
  66 #define TH_PUSH   0x08
  67 #define TH_ACK    0x10
  68 #define TH_URG    0x20
  69 #define TH_ECE    0x40
  70 #define TH_CWR    0x80
  71         u_int16_t th_win;                       /* window */
  72         u_int16_t th_sum;                       /* checksum */
  73         u_int16_t th_urp;                       /* urgent pointer */
  74 } __packed;
  75
  76 #define TCPOPT_EOL              0
  77 #define TCPOPT_NOP              1
  78 #define TCPOPT_MAXSEG           2
  79 #define    TCPOLEN_MAXSEG               4
  80 #define TCPOPT_WINDOW           3
  81 #define    TCPOLEN_WINDOW               3
  82 #define TCPOPT_SACK_PERMITTED   4               /* Experimental */
  83 #define    TCPOLEN_SACK_PERMITTED       2
  84 #define TCPOPT_SACK             5               /* Experimental */
  85 #define TCPOPT_TIMESTAMP        8
  86 #define    TCPOLEN_TIMESTAMP            10
  87 #define    TCPOLEN_TSTAMP_APPA          (TCPOLEN_TIMESTAMP+2) /* appendix A */
  88
  89 #define TCPOPT_TSTAMP_HDR       \
  90     (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)
  91
  92 #define TCPOPT_SIGNATURE        19              /* Keyed MD5: RFC 2385 */
  93 #define    TCPOLEN_SIGNATURE            18
  94 #define    TCPOLEN_SIGLEN               (TCPOLEN_SIGNATURE+2) /* padding */
  95
  96 #define MAX_TCPOPTLEN   40      /* max # bytes that go in options */
  97
  98 /*
  99  * Default maximum segment size for TCP.
 100  * This is defined by RFC 1112 Sec 4.2.2.6.
 101  */
 102 #define TCP_MSS         536
 103
 104 #define TCP_MINMSS      216
 105
 106 #define TCP_MAXWIN      65535   /* largest value for (unscaled) window */
 107
 108 #define TCP_MAX_WINSHIFT        14      /* maximum window shift */
 109
 110 #define TCP_MAXBURST    4       /* maximum segments in a burst */
 111
 112 #endif /* _NETBSD_SOURCE */
 113
 114 /*
 115  * User-settable options (used with setsockopt).
 116  */
 117 #define TCP_NODELAY     1       /* don't delay send to coalesce packets */
 118 #define TCP_MAXSEG      2       /* set maximum segment size */
 119 #define TCP_KEEPIDLE    3
 120 #ifdef notyet
 121 #define TCP_NOPUSH      4       /* reserved for FreeBSD compat */
 122 #endif
 123 #define TCP_KEEPINTVL   5
 124 #define TCP_KEEPCNT     6
 125 #define TCP_KEEPINIT    7
 126 #ifdef notyet
 127 #define TCP_NOOPT       8       /* reserved for FreeBSD compat */
 128 #endif
 129 #define TCP_MD5SIG      0x10    /* use MD5 digests (RFC2385) */
 130 #define TCP_CONGCTL     0x20    /* selected congestion control */
 131
 132 #endif /* !_NETINET_TCP_H_ */