Annotation of sys/netinet/tcp.h, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: tcp.h,v 1.17 2006/04/27 02:19:32 tedu Exp $ */
2: /* $NetBSD: tcp.h,v 1.8 1995/04/17 05:32:58 cgd Exp $ */
3:
4: /*
5: * Copyright (c) 1982, 1986, 1993
6: * The Regents of the University of California. All rights reserved.
7: *
8: * Redistribution and use in source and binary forms, with or without
9: * modification, are permitted provided that the following conditions
10: * are met:
11: * 1. Redistributions of source code must retain the above copyright
12: * notice, this list of conditions and the following disclaimer.
13: * 2. Redistributions in binary form must reproduce the above copyright
14: * notice, this list of conditions and the following disclaimer in the
15: * documentation and/or other materials provided with the distribution.
16: * 3. Neither the name of the University nor the names of its contributors
17: * may be used to endorse or promote products derived from this software
18: * without specific prior written permission.
19: *
20: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30: * SUCH DAMAGE.
31: *
32: * @(#)tcp.h 8.1 (Berkeley) 6/10/93
33: */
34:
35: #ifndef _NETINET_TCP_H_
36: #define _NETINET_TCP_H_
37:
38: typedef u_int32_t tcp_seq;
39:
40: /*
41: * TCP header.
42: * Per RFC 793, September, 1981.
43: */
44: struct tcphdr {
45: u_int16_t th_sport; /* source port */
46: u_int16_t th_dport; /* destination port */
47: tcp_seq th_seq; /* sequence number */
48: tcp_seq th_ack; /* acknowledgement number */
49: #if _BYTE_ORDER == _LITTLE_ENDIAN
50: u_int th_x2:4, /* (unused) */
51: th_off:4; /* data offset */
52: #endif
53: #if _BYTE_ORDER == _BIG_ENDIAN
54: u_int th_off:4, /* data offset */
55: th_x2:4; /* (unused) */
56: #endif
57: u_int8_t th_flags;
58: #define TH_FIN 0x01
59: #define TH_SYN 0x02
60: #define TH_RST 0x04
61: #define TH_PUSH 0x08
62: #define TH_ACK 0x10
63: #define TH_URG 0x20
64: #define TH_ECE 0x40
65: #define TH_CWR 0x80
66: u_int16_t th_win; /* window */
67: u_int16_t th_sum; /* checksum */
68: u_int16_t th_urp; /* urgent pointer */
69: };
70: #define th_reseqlen th_urp /* TCP data length for
71: resequencing/reassembly */
72:
73: #define TCPOPT_EOL 0
74: #define TCPOPT_NOP 1
75: #define TCPOPT_MAXSEG 2
76: #define TCPOLEN_MAXSEG 4
77: #define TCPOPT_WINDOW 3
78: #define TCPOLEN_WINDOW 3
79: #define TCPOPT_SACK_PERMITTED 4 /* Experimental */
80: #define TCPOLEN_SACK_PERMITTED 2
81: #define TCPOPT_SACK 5 /* Experimental */
82: #define TCPOLEN_SACK 8 /* 2*sizeof(tcp_seq) */
83: #define TCPOPT_TIMESTAMP 8
84: #define TCPOLEN_TIMESTAMP 10
85: #define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP+2) /* appendix A */
86: #define TCPOPT_SIGNATURE 19
87: #define TCPOLEN_SIGNATURE 18
88: #define TCPOLEN_SIGLEN (TCPOLEN_SIGNATURE+2) /* padding */
89:
90: #define MAX_TCPOPTLEN 40 /* Absolute maximum TCP options len */
91:
92: #define TCPOPT_TSTAMP_HDR \
93: (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)
94:
95: /* Option definitions */
96: #define TCPOPT_SACK_PERMIT_HDR \
97: (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_SACK_PERMITTED<<8|TCPOLEN_SACK_PERMITTED)
98: #define TCPOPT_SACK_HDR (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_SACK<<8)
99: /* Miscellaneous constants */
100: #define MAX_SACK_BLKS 6 /* Max # SACK blocks stored at sender side */
101: #define TCP_MAX_SACK 3 /* MAX # SACKs sent in any segment */
102:
103: #define TCP_MAXBURST 4 /* Max # packets after leaving Fast Rxmit */
104:
105: /*
106: * Default maximum segment size for TCP.
107: * With an IP MSS of 576, this is 536,
108: * but 512 is probably more convenient.
109: * This should be defined as min(512, IP_MSS - sizeof (struct tcpiphdr)).
110: */
111: #define TCP_MSS 512
112:
113: #define TCP_MAXWIN 65535 /* largest value for (unscaled) window */
114:
115: #define TCP_MAX_WINSHIFT 14 /* maximum window shift */
116:
117: /*
118: * User-settable options (used with setsockopt).
119: */
120: #define TCP_NODELAY 0x01 /* don't delay send to coalesce pkts */
121: #define TCP_MAXSEG 0x02 /* set maximum segment size */
122: #define TCP_MD5SIG 0x04 /* enable TCP MD5 signature option */
123: #define TCP_SACK_ENABLE 0x08 /* enable SACKs (if disabled by def.) */
124:
125: #endif /* _NETINET_TCP_H_ */
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