1/*
2 * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/*
29 * Copyright (c) 1982, 1986, 1993
30 *	The Regents of the University of California.  All rights reserved.
31 *
32 * Redistribution and use in source and binary forms, with or without
33 * modification, are permitted provided that the following conditions
34 * are met:
35 * 1. Redistributions of source code must retain the above copyright
36 *    notice, this list of conditions and the following disclaimer.
37 * 2. Redistributions in binary form must reproduce the above copyright
38 *    notice, this list of conditions and the following disclaimer in the
39 *    documentation and/or other materials provided with the distribution.
40 * 3. All advertising materials mentioning features or use of this software
41 *    must display the following acknowledgement:
42 *	This product includes software developed by the University of
43 *	California, Berkeley and its contributors.
44 * 4. Neither the name of the University nor the names of its contributors
45 *    may be used to endorse or promote products derived from this software
46 *    without specific prior written permission.
47 *
48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58 * SUCH DAMAGE.
59 *
60 *	@(#)tcp.h	8.1 (Berkeley) 6/10/93
61 * $FreeBSD: src/sys/netinet/tcp.h,v 1.13.2.3 2001/03/01 22:08:42 jlemon Exp $
62 */
63
64#ifndef _NETINET_TCP_H_
65#define _NETINET_TCP_H_
66#include <sys/appleapiopts.h>
67#include <sys/_types.h>
68#include <machine/endian.h>
69
70#if !defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE)
71typedef	__uint32_t tcp_seq;
72typedef __uint32_t tcp_cc;		/* connection count per rfc1644 */
73
74#define tcp6_seq	tcp_seq	/* for KAME src sync over BSD*'s */
75#define tcp6hdr		tcphdr	/* for KAME src sync over BSD*'s */
76
77/*
78 * TCP header.
79 * Per RFC 793, September, 1981.
80 */
81struct tcphdr {
82	unsigned short	th_sport;	/* source port */
83	unsigned short	th_dport;	/* destination port */
84	tcp_seq	th_seq;			/* sequence number */
85	tcp_seq	th_ack;			/* acknowledgement number */
86#if __DARWIN_BYTE_ORDER == __DARWIN_LITTLE_ENDIAN
87	unsigned int	th_x2:4,	/* (unused) */
88			th_off:4;	/* data offset */
89#endif
90#if __DARWIN_BYTE_ORDER == __DARWIN_BIG_ENDIAN
91	unsigned int	th_off:4,	/* data offset */
92			th_x2:4;	/* (unused) */
93#endif
94	unsigned char	th_flags;
95#define	TH_FIN	0x01
96#define	TH_SYN	0x02
97#define	TH_RST	0x04
98#define	TH_PUSH	0x08
99#define	TH_ACK	0x10
100#define	TH_URG	0x20
101#define	TH_ECE	0x40
102#define	TH_CWR	0x80
103#define	TH_FLAGS	(TH_FIN|TH_SYN|TH_RST|TH_ACK|TH_URG|TH_ECE|TH_CWR)
104
105	unsigned short	th_win;		/* window */
106	unsigned short	th_sum;		/* checksum */
107	unsigned short	th_urp;		/* urgent pointer */
108};
109
110#define	TCPOPT_EOL		0
111#define	TCPOPT_NOP		1
112#define	TCPOPT_MAXSEG		2
113#define TCPOLEN_MAXSEG		4
114#define TCPOPT_WINDOW		3
115#define TCPOLEN_WINDOW		3
116#define TCPOPT_SACK_PERMITTED	4		/* Experimental */
117#define TCPOLEN_SACK_PERMITTED	2
118#define TCPOPT_SACK		5		/* Experimental */
119#define TCPOLEN_SACK		8		/* len of sack block */
120#define TCPOPT_TIMESTAMP	8
121#define TCPOLEN_TIMESTAMP	10
122#define TCPOLEN_TSTAMP_APPA		(TCPOLEN_TIMESTAMP+2) /* appendix A */
123#define TCPOPT_TSTAMP_HDR		\
124    (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)
125
126#define	MAX_TCPOPTLEN		40	/* Absolute maximum TCP options len */
127
128#define	TCPOPT_CC		11		/* CC options: RFC-1644 */
129#define TCPOPT_CCNEW		12
130#define TCPOPT_CCECHO		13
131#define	   TCPOLEN_CC			6
132#define	   TCPOLEN_CC_APPA		(TCPOLEN_CC+2)
133#define	   TCPOPT_CC_HDR(ccopt)		\
134    (TCPOPT_NOP<<24|TCPOPT_NOP<<16|(ccopt)<<8|TCPOLEN_CC)
135#define	TCPOPT_SIGNATURE		19	/* Keyed MD5: RFC 2385 */
136#define	   TCPOLEN_SIGNATURE		18
137
138/* Option definitions */
139#define TCPOPT_SACK_PERMIT_HDR	\
140(TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_SACK_PERMITTED<<8|TCPOLEN_SACK_PERMITTED)
141#define	TCPOPT_SACK_HDR		(TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_SACK<<8)
142/* Miscellaneous constants */
143#define	MAX_SACK_BLKS	6	/* Max # SACK blocks stored at sender side */
144#define	TCP_MAX_SACK	3	/* MAX # SACKs sent in any segment */
145
146
147/*
148 * Default maximum segment size for TCP.
149 * With an IP MTU of 576, this is 536,
150 * but 512 is probably more convenient.
151 * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)).
152 */
153#define	TCP_MSS	512
154
155/*
156 * TCP_MINMSS is defined to be 216 which is fine for the smallest
157 * link MTU (256 bytes, SLIP interface) in the Internet.
158 * However it is very unlikely to come across such low MTU interfaces
159 * these days (anno dato 2004).
160 * Probably it can be set to 512 without ill effects. But we play safe.
161 * See tcp_subr.c tcp_minmss SYSCTL declaration for more comments.
162 * Setting this to "0" disables the minmss check.
163 */
164#define	TCP_MINMSS 216
165
166/*
167 * TCP_MINMSSOVERLOAD is defined to be 1000 which should cover any type
168 * of interactive TCP session.
169 * See tcp_subr.c tcp_minmssoverload SYSCTL declaration and tcp_input.c
170 * for more comments.
171 * Setting this to "0" disables the minmssoverload check.
172 */
173#define	TCP_MINMSSOVERLOAD 1000
174
175/*
176 * Default maximum segment size for TCP6.
177 * With an IP6 MSS of 1280, this is 1220,
178 * but 1024 is probably more convenient. (xxx kazu in doubt)
179 * This should be defined as MIN(1024, IP6_MSS - sizeof (struct tcpip6hdr))
180 */
181#define	TCP6_MSS	1024
182
183#define	TCP_MAXWIN	65535	/* largest value for (unscaled) window */
184#define	TTCP_CLIENT_SND_WND	4096	/* dflt send window for T/TCP client */
185
186#define TCP_MAX_WINSHIFT	14	/* maximum window shift */
187
188#define TCP_MAXBURST		4 	/* maximum segments in a burst */
189
190#define TCP_MAXHLEN	(0xf<<2)	/* max length of header in bytes */
191#define TCP_MAXOLEN	(TCP_MAXHLEN - sizeof(struct tcphdr))
192					/* max space left for options */
193#endif /* (_POSIX_C_SOURCE && !_DARWIN_C_SOURCE) */
194
195/*
196 * User-settable options (used with setsockopt).
197 */
198#define	TCP_NODELAY	0x01	/* don't delay send to coalesce packets */
199#if !defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE)
200#define	TCP_MAXSEG	0x02	/* set maximum segment size */
201#define TCP_NOPUSH	0x04	/* don't push last block of write */
202#define TCP_NOOPT	0x08	/* don't use TCP options */
203#define TCP_KEEPALIVE	0x10	/* idle time used when SO_KEEPALIVE is enabled */
204#endif /* (_POSIX_C_SOURCE && !_DARWIN_C_SOURCE) */
205
206#endif
207