1/* @(#) $Header: /tcpdump/master/tcpdump/tcp.h,v 1.11.2.1 2005/11/29 09:09:26 hannes 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
37typedef	u_int32_t	tcp_seq;
38/*
39 * TCP header.
40 * Per RFC 793, September, 1981.
41 */
42struct 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#define TH_ECNECHO	0x40	/* ECN Echo */
57#define TH_CWR		0x80	/* ECN Cwnd Reduced */
58	u_int16_t	th_win;			/* window */
59	u_int16_t	th_sum;			/* checksum */
60	u_int16_t	th_urp;			/* urgent pointer */
61};
62
63#define	TCPOPT_EOL		0
64#define	TCPOPT_NOP		1
65#define	TCPOPT_MAXSEG		2
66#define    TCPOLEN_MAXSEG		4
67#define	TCPOPT_WSCALE		3	/* window scale factor (rfc1323) */
68#define	TCPOPT_SACKOK		4	/* selective ack ok (rfc2018) */
69#define	TCPOPT_SACK		5	/* selective ack (rfc2018) */
70#define	TCPOPT_ECHO		6	/* echo (rfc1072) */
71#define	TCPOPT_ECHOREPLY	7	/* echo (rfc1072) */
72#define TCPOPT_TIMESTAMP	8	/* timestamp (rfc1323) */
73#define    TCPOLEN_TIMESTAMP		10
74#define    TCPOLEN_TSTAMP_APPA		(TCPOLEN_TIMESTAMP+2) /* appendix A */
75#define TCPOPT_CC		11	/* T/TCP CC options (rfc1644) */
76#define TCPOPT_CCNEW		12	/* T/TCP CC options (rfc1644) */
77#define TCPOPT_CCECHO		13	/* T/TCP CC options (rfc1644) */
78#define TCPOPT_SIGNATURE	19	/* Keyed MD5 (rfc2385) */
79#define    TCPOLEN_SIGNATURE		18
80#define TCP_SIGLEN 16			/* length of an option 19 digest */
81#define TCPOPT_AUTH             20      /* Enhanced AUTH option */
82
83#define TCPOPT_TSTAMP_HDR	\
84    (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)
85