2 * TCP header and options.
5 /* $NetBSD: tcp.h,v 1.8 1995/04/17 05:32:58 cgd Exp $ */
8 * Copyright (c) 1982, 1986, 1993
9 * The Regents of the University of California. All rights reserved.
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12 * modification, are permitted provided that the following conditions
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15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
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19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the University of
22 * California, Berkeley and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 * may be used to endorse or promote products derived from this software
25 * without specific prior written permission.
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33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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39 * @(#)tcp.h 8.1 (Berkeley) 6/10/93
42 #ifndef __NETINET_TCP_H
43 #define __NETINET_TCP_H
45 typedef u_long tcp_seq;
46 typedef u_long tcp_cc; /* connection count per rfc1644 */
48 #include <sys/packon.h>
53 * Per RFC 793, September, 1981.
56 u_short th_sport; /* source port */
57 u_short th_dport; /* destination port */
58 tcp_seq th_seq; /* sequence number */
59 tcp_seq th_ack; /* acknowledgement number */
60 u_char th_x2:4; /* (unused) */
61 u_char th_off:4; /* data offset */
69 #define TH_FLAGS (TH_FIN|TH_SYN|TH_RST|TH_ACK|TH_URG)
71 u_short th_win; /* window */
72 u_short th_sum; /* checksum */
73 u_short th_urp; /* urgent pointer */
76 #include <sys/packoff.h>
80 #define TCPOPT_MAXSEG 2
81 #define TCPOLEN_MAXSEG 4
82 #define TCPOPT_WINDOW 3
83 #define TCPOLEN_WINDOW 3
84 #define TCPOPT_SACK_PERMITTED 4
85 #define TCPOLEN_SACK_PERMITTED 2
87 #define TCPOPT_TIMESTAMP 8
88 #define TCPOLEN_TIMESTAMP 10
89 #define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP+2) /* appendix A */
91 #define TCPOPT_TSTAMP_HDR \
92 (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)
94 #define TCPOPT_CC 11 /* CC options: RFC-1644 */
95 #define TCPOPT_CCNEW 12
96 #define TCPOPT_CCECHO 13
98 #define TCPOLEN_CC_APPA (TCPOLEN_CC+2)
99 #define TCPOPT_CC_HDR(ccopt) \
100 (TCPOPT_NOP<<24|TCPOPT_NOP<<16|(ccopt)<<8|TCPOLEN_CC)
102 #define TCPOPT_SIGNATURE 19
103 #define TCP_SIGLEN 16
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)).
113 #define TCP_MAXWIN 65535 /* largest value for (unscaled) window */
114 #define TTCP_CLIENT_SND_WND 4096 /* dflt send window for T/TCP client */
116 #define TCP_MAX_WINSHIFT 14 /* maximum window shift */
118 #define TCP_MAXHLEN (0xf<<2) /* max length of header in bytes */
119 #define TCP_MAXOLEN (TCP_MAXHLEN - sizeof(struct tcphdr))
120 /* max space left for options */
123 * User-settable options (used with setsockopt).
125 #define TCP_NODELAY 0x01 /* don't delay send to coalesce packets */
126 #define TCP_MAXSEG 0x02 /* set maximum segment size */
128 #define TCP_AUTO_OP 0x03 /* 0 to disable autotuning, 1 to reenable */
130 #define TCP_NOPUSH 0x04 /* don't push last block of write */
131 #define TCP_NOOPT 0x08 /* don't use TCP options */
133 /* For PSC modifications */
134 #if defined(TCP_AUTO) || defined(TCP_SACK) || defined(TCP_FACK)
135 #define PSC_VERSION "0.8"