xref: /freebsd/sys/netinet/tcp.h (revision 65450f2f77f82c5083ecd137a9c02767423cdf13)
1df8bae1dSRodney W. Grimes /*
2df8bae1dSRodney W. Grimes  * Copyright (c) 1982, 1986, 1993
3df8bae1dSRodney W. Grimes  *	The Regents of the University of California.  All rights reserved.
4df8bae1dSRodney W. Grimes  *
5df8bae1dSRodney W. Grimes  * Redistribution and use in source and binary forms, with or without
6df8bae1dSRodney W. Grimes  * modification, are permitted provided that the following conditions
7df8bae1dSRodney W. Grimes  * are met:
8df8bae1dSRodney W. Grimes  * 1. Redistributions of source code must retain the above copyright
9df8bae1dSRodney W. Grimes  *    notice, this list of conditions and the following disclaimer.
10df8bae1dSRodney W. Grimes  * 2. Redistributions in binary form must reproduce the above copyright
11df8bae1dSRodney W. Grimes  *    notice, this list of conditions and the following disclaimer in the
12df8bae1dSRodney W. Grimes  *    documentation and/or other materials provided with the distribution.
13df8bae1dSRodney W. Grimes  * 3. All advertising materials mentioning features or use of this software
14df8bae1dSRodney W. Grimes  *    must display the following acknowledgement:
15df8bae1dSRodney W. Grimes  *	This product includes software developed by the University of
16df8bae1dSRodney W. Grimes  *	California, Berkeley and its contributors.
17df8bae1dSRodney W. Grimes  * 4. Neither the name of the University nor the names of its contributors
18df8bae1dSRodney W. Grimes  *    may be used to endorse or promote products derived from this software
19df8bae1dSRodney W. Grimes  *    without specific prior written permission.
20df8bae1dSRodney W. Grimes  *
21df8bae1dSRodney W. Grimes  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22df8bae1dSRodney W. Grimes  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23df8bae1dSRodney W. Grimes  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24df8bae1dSRodney W. Grimes  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25df8bae1dSRodney W. Grimes  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26df8bae1dSRodney W. Grimes  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27df8bae1dSRodney W. Grimes  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28df8bae1dSRodney W. Grimes  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29df8bae1dSRodney W. Grimes  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30df8bae1dSRodney W. Grimes  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31df8bae1dSRodney W. Grimes  * SUCH DAMAGE.
32df8bae1dSRodney W. Grimes  *
33df8bae1dSRodney W. Grimes  *	@(#)tcp.h	8.1 (Berkeley) 6/10/93
34c3aac50fSPeter Wemm  * $FreeBSD$
35df8bae1dSRodney W. Grimes  */
36df8bae1dSRodney W. Grimes 
37707f139eSPaul Richards #ifndef _NETINET_TCP_H_
38707f139eSPaul Richards #define _NETINET_TCP_H_
39707f139eSPaul Richards 
4007a4df4fSBruce Evans typedef	u_int32_t tcp_seq;
4107a4df4fSBruce Evans typedef u_int32_t tcp_cc;		/* connection count per rfc1644 */
42eb6ad696SGarrett Wollman 
43fb59c426SYoshinobu Inoue #define tcp6_seq	tcp_seq	/* for KAME src sync over BSD*'s */
44fb59c426SYoshinobu Inoue #define tcp6hdr		tcphdr	/* for KAME src sync over BSD*'s */
45fb59c426SYoshinobu Inoue 
46df8bae1dSRodney W. Grimes /*
47df8bae1dSRodney W. Grimes  * TCP header.
48df8bae1dSRodney W. Grimes  * Per RFC 793, September, 1981.
49df8bae1dSRodney W. Grimes  */
50df8bae1dSRodney W. Grimes struct tcphdr {
51df8bae1dSRodney W. Grimes 	u_short	th_sport;		/* source port */
52df8bae1dSRodney W. Grimes 	u_short	th_dport;		/* destination port */
53df8bae1dSRodney W. Grimes 	tcp_seq	th_seq;			/* sequence number */
54df8bae1dSRodney W. Grimes 	tcp_seq	th_ack;			/* acknowledgement number */
55df8bae1dSRodney W. Grimes #if BYTE_ORDER == LITTLE_ENDIAN
56a09bee1aSBruce Evans 	u_int	th_x2:4,		/* (unused) */
57df8bae1dSRodney W. Grimes 		th_off:4;		/* data offset */
58df8bae1dSRodney W. Grimes #endif
59df8bae1dSRodney W. Grimes #if BYTE_ORDER == BIG_ENDIAN
60a09bee1aSBruce Evans 	u_int	th_off:4,		/* data offset */
61df8bae1dSRodney W. Grimes 		th_x2:4;		/* (unused) */
62df8bae1dSRodney W. Grimes #endif
63df8bae1dSRodney W. Grimes 	u_char	th_flags;
64df8bae1dSRodney W. Grimes #define	TH_FIN	0x01
65df8bae1dSRodney W. Grimes #define	TH_SYN	0x02
66df8bae1dSRodney W. Grimes #define	TH_RST	0x04
67df8bae1dSRodney W. Grimes #define	TH_PUSH	0x08
68df8bae1dSRodney W. Grimes #define	TH_ACK	0x10
69df8bae1dSRodney W. Grimes #define	TH_URG	0x20
7065450f2fSRobert Watson #define	TH_ECE	0x40
7165450f2fSRobert Watson #define	TH_CWR	0x80
7265450f2fSRobert Watson #define TH_FLAGS (TH_FIN|TH_SYN|TH_RST|TH_ACK|TH_URG|TH_ECE|TH_CWR)
732f96f1f4SGarrett Wollman 
74df8bae1dSRodney W. Grimes 	u_short	th_win;			/* window */
75df8bae1dSRodney W. Grimes 	u_short	th_sum;			/* checksum */
76df8bae1dSRodney W. Grimes 	u_short	th_urp;			/* urgent pointer */
77df8bae1dSRodney W. Grimes };
78df8bae1dSRodney W. Grimes 
79df8bae1dSRodney W. Grimes #define	TCPOPT_EOL		0
80df8bae1dSRodney W. Grimes #define	TCPOPT_NOP		1
81df8bae1dSRodney W. Grimes #define	TCPOPT_MAXSEG		2
82df8bae1dSRodney W. Grimes #define    TCPOLEN_MAXSEG		4
83df8bae1dSRodney W. Grimes #define TCPOPT_WINDOW		3
84df8bae1dSRodney W. Grimes #define    TCPOLEN_WINDOW		3
85df8bae1dSRodney W. Grimes #define TCPOPT_SACK_PERMITTED	4		/* Experimental */
86df8bae1dSRodney W. Grimes #define    TCPOLEN_SACK_PERMITTED	2
87df8bae1dSRodney W. Grimes #define TCPOPT_SACK		5		/* Experimental */
88df8bae1dSRodney W. Grimes #define TCPOPT_TIMESTAMP	8
89df8bae1dSRodney W. Grimes #define    TCPOLEN_TIMESTAMP		10
90df8bae1dSRodney W. Grimes #define    TCPOLEN_TSTAMP_APPA		(TCPOLEN_TIMESTAMP+2) /* appendix A */
91df8bae1dSRodney W. Grimes #define    TCPOPT_TSTAMP_HDR		\
92df8bae1dSRodney W. Grimes     (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)
93df8bae1dSRodney W. Grimes 
94eb6ad696SGarrett Wollman #define	TCPOPT_CC		11		/* CC options: RFC-1644 */
95eb6ad696SGarrett Wollman #define TCPOPT_CCNEW		12
96eb6ad696SGarrett Wollman #define TCPOPT_CCECHO		13
97eb6ad696SGarrett Wollman #define	   TCPOLEN_CC			6
98eb6ad696SGarrett Wollman #define	   TCPOLEN_CC_APPA		(TCPOLEN_CC+2)
99eb6ad696SGarrett Wollman #define	   TCPOPT_CC_HDR(ccopt)		\
100eb6ad696SGarrett Wollman     (TCPOPT_NOP<<24|TCPOPT_NOP<<16|(ccopt)<<8|TCPOLEN_CC)
101eb6ad696SGarrett Wollman 
102df8bae1dSRodney W. Grimes /*
103df8bae1dSRodney W. Grimes  * Default maximum segment size for TCP.
104df8bae1dSRodney W. Grimes  * With an IP MSS of 576, this is 536,
105df8bae1dSRodney W. Grimes  * but 512 is probably more convenient.
106df8bae1dSRodney W. Grimes  * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)).
107df8bae1dSRodney W. Grimes  */
108df8bae1dSRodney W. Grimes #define	TCP_MSS	512
109df8bae1dSRodney W. Grimes 
11076429de4SYoshinobu Inoue /*
11176429de4SYoshinobu Inoue  * Default maximum segment size for TCP6.
11276429de4SYoshinobu Inoue  * With an IP6 MSS of 1280, this is 1220,
11376429de4SYoshinobu Inoue  * but 1024 is probably more convenient. (xxx kazu in doubt)
11476429de4SYoshinobu Inoue  * This should be defined as MIN(1024, IP6_MSS - sizeof (struct tcpip6hdr))
11576429de4SYoshinobu Inoue  */
11676429de4SYoshinobu Inoue #define	TCP6_MSS	1024
11776429de4SYoshinobu Inoue 
118df8bae1dSRodney W. Grimes #define	TCP_MAXWIN	65535	/* largest value for (unscaled) window */
119eb6ad696SGarrett Wollman #define	TTCP_CLIENT_SND_WND	4096	/* dflt send window for T/TCP client */
120df8bae1dSRodney W. Grimes 
121df8bae1dSRodney W. Grimes #define TCP_MAX_WINSHIFT	14	/* maximum window shift */
122df8bae1dSRodney W. Grimes 
12346f58482SJonathan Lemon #define TCP_MAXBURST		4 	/* maximum segments in a burst */
12446f58482SJonathan Lemon 
125eb6ad696SGarrett Wollman #define TCP_MAXHLEN	(0xf<<2)	/* max length of header in bytes */
126eb6ad696SGarrett Wollman #define TCP_MAXOLEN	(TCP_MAXHLEN - sizeof(struct tcphdr))
127eb6ad696SGarrett Wollman 					/* max space left for options */
128eb6ad696SGarrett Wollman 
129df8bae1dSRodney W. Grimes /*
130df8bae1dSRodney W. Grimes  * User-settable options (used with setsockopt).
131df8bae1dSRodney W. Grimes  */
132df8bae1dSRodney W. Grimes #define	TCP_NODELAY	0x01	/* don't delay send to coalesce packets */
133df8bae1dSRodney W. Grimes #define	TCP_MAXSEG	0x02	/* set maximum segment size */
134eb6ad696SGarrett Wollman #define TCP_NOPUSH	0x04	/* don't push last block of write */
135eb6ad696SGarrett Wollman #define TCP_NOOPT	0x08	/* don't use TCP options */
136707f139eSPaul Richards 
137707f139eSPaul Richards #endif
138