The Tcpdump Group git mirrors - tcpdump/blob - tcp.h

   1 /* @(#) $Header: /tcpdump/master/tcpdump/tcp.h,v 1.7 2000-10-03 09:17:41 guy Exp $ (LBL) */
   2 /*
   3  * Copyright (c) 1982, 1986, 1993
   4  *      The Regents of the University of California.  All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. All advertising materials mentioning features or use of this software
  15  *    must display the following acknowledgement:
  16  *      This product includes software developed by the University of
  17  *      California, Berkeley and its contributors.
  18  * 4. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  *      @(#)tcp.h       8.1 (Berkeley) 6/10/93
  35  */
  36
  37 typedef u_int32_t       tcp_seq;
  38 /*
  39  * TCP header.
  40  * Per RFC 793, September, 1981.
  41  */
  42 struct tcphdr {
  43         u_int16_t       th_sport;               /* source port */
  44         u_int16_t       th_dport;               /* destination port */
  45         tcp_seq         th_seq;                 /* sequence number */
  46         tcp_seq         th_ack;                 /* acknowledgement number */
  47         u_int8_t        th_offx2;               /* data offset, rsvd */
  48 #define TH_OFF(th)      (((th)->th_offx2 & 0xf0) >> 4)
  49         u_int8_t        th_flags;
  50 #define TH_FIN  0x01
  51 #define TH_SYN  0x02
  52 #define TH_RST  0x04
  53 #define TH_PUSH 0x08
  54 #define TH_ACK  0x10
  55 #define TH_URG  0x20
  56         u_int16_t       th_win;                 /* window */
  57         u_int16_t       th_sum;                 /* checksum */
  58         u_int16_t       th_urp;                 /* urgent pointer */
  59 };
  60
  61 #define TCPOPT_EOL              0
  62 #define TCPOPT_NOP              1
  63 #define TCPOPT_MAXSEG           2
  64 #define    TCPOLEN_MAXSEG               4
  65 #define TCPOPT_WINDOW           3
  66 #define    TCPOLEN_WINDOW               3
  67 #define TCPOPT_SACK_PERMITTED   4               /* Experimental */
  68 #define    TCPOLEN_SACK_PERMITTED       2
  69 #define TCPOPT_SACK             5               /* Experimental */
  70 #define TCPOPT_TIMESTAMP        8
  71 #define    TCPOLEN_TIMESTAMP            10
  72 #define    TCPOLEN_TSTAMP_APPA          (TCPOLEN_TIMESTAMP+2) /* appendix A */
  73
  74 #define TCPOPT_TSTAMP_HDR       \
  75     (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)