5cd425b9ccbd2b8b62fde1886e0212a341bb397b
[apple/xnu.git] / bsd / netinet / tcp.h
1 /*
2 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_LICENSE_HEADER_START@
5 *
6 * The contents of this file constitute Original Code as defined in and
7 * are subject to the Apple Public Source License Version 1.1 (the
8 * "License"). You may not use this file except in compliance with the
9 * License. Please obtain a copy of the License at
10 * http://www.apple.com/publicsource and read it before using this file.
11 *
12 * This Original Code and all software distributed under the License are
13 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
14 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
15 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
17 * License for the specific language governing rights and limitations
18 * under the License.
19 *
20 * @APPLE_LICENSE_HEADER_END@
21 */
22 /*
23 * Copyright (c) 1982, 1986, 1993
24 * The Regents of the University of California. All rights reserved.
25 *
26 * Redistribution and use in source and binary forms, with or without
27 * modification, are permitted provided that the following conditions
28 * are met:
29 * 1. Redistributions of source code must retain the above copyright
30 * notice, this list of conditions and the following disclaimer.
31 * 2. Redistributions in binary form must reproduce the above copyright
32 * notice, this list of conditions and the following disclaimer in the
33 * documentation and/or other materials provided with the distribution.
34 * 3. All advertising materials mentioning features or use of this software
35 * must display the following acknowledgement:
36 * This product includes software developed by the University of
37 * California, Berkeley and its contributors.
38 * 4. Neither the name of the University nor the names of its contributors
39 * may be used to endorse or promote products derived from this software
40 * without specific prior written permission.
41 *
42 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
43 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
44 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
45 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
46 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
47 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
48 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
49 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
50 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
51 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52 * SUCH DAMAGE.
53 *
54 * @(#)tcp.h 8.1 (Berkeley) 6/10/93
55 */
56
57 #ifndef _NETINET_TCP_H_
58 #define _NETINET_TCP_H_
59
60 typedef u_int32_t tcp_seq;
61 typedef u_int32_t tcp_cc; /* connection count per rfc1644 */
62
63 #define tcp6_seq tcp_seq /* for KAME src sync over BSD*'s */
64 #define tcp6hdr tcphdr /* for KAME src sync over BSD*'s */
65
66 /*
67 * TCP header.
68 * Per RFC 793, September, 1981.
69 */
70 struct tcphdr {
71 u_short th_sport; /* source port */
72 u_short th_dport; /* destination port */
73 tcp_seq th_seq; /* sequence number */
74 tcp_seq th_ack; /* acknowledgement number */
75 #if BYTE_ORDER == LITTLE_ENDIAN
76 u_int th_x2:4, /* (unused) */
77 th_off:4; /* data offset */
78 #endif
79 #if BYTE_ORDER == BIG_ENDIAN
80 u_int th_off:4, /* data offset */
81 th_x2:4; /* (unused) */
82 #endif
83 u_char th_flags;
84 #define TH_FIN 0x01
85 #define TH_SYN 0x02
86 #define TH_RST 0x04
87 #define TH_PUSH 0x08
88 #define TH_ACK 0x10
89 #define TH_URG 0x20
90 #define TH_FLAGS (TH_FIN|TH_SYN|TH_RST|TH_ACK|TH_URG)
91
92 u_short th_win; /* window */
93 u_short th_sum; /* checksum */
94 u_short th_urp; /* urgent pointer */
95 };
96
97 #define TCPOPT_EOL 0
98 #define TCPOPT_NOP 1
99 #define TCPOPT_MAXSEG 2
100 #define TCPOLEN_MAXSEG 4
101 #define TCPOPT_WINDOW 3
102 #define TCPOLEN_WINDOW 3
103 #define TCPOPT_SACK_PERMITTED 4 /* Experimental */
104 #define TCPOLEN_SACK_PERMITTED 2
105 #define TCPOPT_SACK 5 /* Experimental */
106 #define TCPOPT_TIMESTAMP 8
107 #define TCPOLEN_TIMESTAMP 10
108 #define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP+2) /* appendix A */
109 #define TCPOPT_TSTAMP_HDR \
110 (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)
111
112 #define TCPOPT_CC 11 /* CC options: RFC-1644 */
113 #define TCPOPT_CCNEW 12
114 #define TCPOPT_CCECHO 13
115 #define TCPOLEN_CC 6
116 #define TCPOLEN_CC_APPA (TCPOLEN_CC+2)
117 #define TCPOPT_CC_HDR(ccopt) \
118 (TCPOPT_NOP<<24|TCPOPT_NOP<<16|(ccopt)<<8|TCPOLEN_CC)
119
120 /*
121 * Default maximum segment size for TCP.
122 * With an IP MSS of 576, this is 536,
123 * but 512 is probably more convenient.
124 * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)).
125 */
126 #define TCP_MSS 512
127
128 /*
129 * Default maximum segment size for TCP6.
130 * With an IP6 MSS of 1280, this is 1220,
131 * but 1024 is probably more convenient. (xxx kazu in doubt)
132 * This should be defined as MIN(1024, IP6_MSS - sizeof (struct tcpip6hdr))
133 */
134 #define TCP6_MSS 1024
135
136 #define TCP_MAXWIN 65535 /* largest value for (unscaled) window */
137 #define TTCP_CLIENT_SND_WND 4096 /* dflt send window for T/TCP client */
138
139 #define TCP_MAX_WINSHIFT 14 /* maximum window shift */
140
141 #define TCP_MAXHLEN (0xf<<2) /* max length of header in bytes */
142 #define TCP_MAXOLEN (TCP_MAXHLEN - sizeof(struct tcphdr))
143 /* max space left for options */
144
145 /*
146 * User-settable options (used with setsockopt).
147 */
148 #define TCP_NODELAY 0x01 /* don't delay send to coalesce packets */
149 #define TCP_MAXSEG 0x02 /* set maximum segment size */
150 #define TCP_NOPUSH 0x04 /* don't push last block of write */
151 #define TCP_NOOPT 0x08 /* don't use TCP options */
152
153 #endif