summaryrefslogtreecommitdiff
path: root/sys/netinet/tcp.h
blob: b9cf23d4c53eac9c09008cede707e116efd9560d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
/*	$OpenBSD: tcp.h,v 1.23 2022/08/11 09:13:21 claudio Exp $	*/
/*	$NetBSD: tcp.h,v 1.8 1995/04/17 05:32:58 cgd Exp $	*/

/*
 * Copyright (c) 1982, 1986, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)tcp.h	8.1 (Berkeley) 6/10/93
 */

#ifndef _NETINET_TCP_H_
#define	_NETINET_TCP_H_

#include <sys/cdefs.h>

#if __BSD_VISIBLE

typedef u_int32_t tcp_seq;

/*
 * TCP header.
 * Per RFC 793, September, 1981.
 */
struct tcphdr {
	u_int16_t th_sport;		/* source port */
	u_int16_t th_dport;		/* destination port */
	tcp_seq	  th_seq;		/* sequence number */
	tcp_seq	  th_ack;		/* acknowledgement number */
#if _BYTE_ORDER == _LITTLE_ENDIAN
	u_int32_t th_x2:4,		/* (unused) */
		  th_off:4;		/* data offset */
#endif
#if _BYTE_ORDER == _BIG_ENDIAN
	u_int32_t th_off:4,		/* data offset */
		  th_x2:4;		/* (unused) */
#endif
	u_int8_t  th_flags;
#define	TH_FIN	  0x01
#define	TH_SYN	  0x02
#define	TH_RST	  0x04
#define	TH_PUSH	  0x08
#define	TH_ACK	  0x10
#define	TH_URG	  0x20
#define	TH_ECE	  0x40
#define	TH_CWR	  0x80
	u_int16_t th_win;			/* window */
	u_int16_t th_sum;			/* checksum */
	u_int16_t th_urp;			/* urgent pointer */
};
#define th_reseqlen th_urp			/* TCP data length for
						   resequencing/reassembly */

#define	TCPOPT_EOL		0
#define	TCPOPT_NOP		1
#define	TCPOPT_MAXSEG		2
#define	TCPOLEN_MAXSEG		4
#define	TCPOPT_WINDOW		3
#define	TCPOLEN_WINDOW		3
#define	TCPOPT_SACK_PERMITTED	4		/* Experimental */
#define	TCPOLEN_SACK_PERMITTED	2
#define	TCPOPT_SACK		5		/* Experimental */
#define	TCPOLEN_SACK		8		/* 2*sizeof(tcp_seq) */
#define	TCPOPT_TIMESTAMP	8
#define	TCPOLEN_TIMESTAMP		10
#define	TCPOLEN_TSTAMP_APPA		(TCPOLEN_TIMESTAMP+2) /* appendix A */
#define	TCPOPT_SIGNATURE	19
#define	TCPOLEN_SIGNATURE		18
#define	TCPOLEN_SIGLEN		(TCPOLEN_SIGNATURE+2) /* padding */

#define	MAX_TCPOPTLEN		40	/* Absolute maximum TCP options len */

#define	TCPOPT_TSTAMP_HDR	\
    (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)

/* Option definitions */
#define	TCPOPT_SACK_PERMIT_HDR \
(TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_SACK_PERMITTED<<8|TCPOLEN_SACK_PERMITTED)
#define	TCPOPT_SACK_HDR   (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_SACK<<8)
/* Miscellaneous constants */
#define	MAX_SACK_BLKS	6	/* Max # SACK blocks stored at sender side */
#define	TCP_MAX_SACK	3	/* Max # SACKs sent in any segment */
#define	TCP_SACKHOLE_LIMIT 128	/* Max # SACK holes per connection */

/*
 * Default maximum segment size for TCP.
 * With an IP MSS of 576, this is 536,
 * but 512 is probably more convenient.
 * This should be defined as min(512, IP_MSS - sizeof (struct tcpiphdr)).
 */
#define	TCP_MSS		512

#define	TCP_MAXWIN	65535	/* largest value for (unscaled) window */

#define	TCP_MAX_WINSHIFT	14	/* maximum window shift */

#endif /* __BSD_VISIBLE */

/*
 * User-settable options (used with setsockopt).
 */
#define	TCP_NODELAY		0x01   /* don't delay send to coalesce pkts */
#define	TCP_MAXSEG		0x02   /* set maximum segment size */
#define	TCP_MD5SIG		0x04   /* enable TCP MD5 signature option */
#define	TCP_SACK_ENABLE		0x08   /* enable SACKs (if disabled by def.) */
#define	TCP_INFO		0x09   /* retrieve tcp_info structure */
#define	TCP_NOPUSH		0x10   /* don't push last block of write */

#define	TCPI_OPT_TIMESTAMPS	0x01
#define	TCPI_OPT_SACK		0x02
#define	TCPI_OPT_WSCALE		0x04
#define	TCPI_OPT_ECN		0x08
#define	TCPI_OPT_TOE		0x10

/*
 * The TCP_INFO socket option comes from the Linux 2.6 TCP API, and permits
 * the caller to query certain information about the state of a TCP
 * connection.  Provide an overlapping set of fields with the Linux
 * implementation, but at the same time add a lot of OpenBSD specific
 * extra information.
 */
struct tcp_info {
	uint8_t		tcpi_state;		/* TCP FSM state. */
	uint8_t		__tcpi_ca_state;
	uint8_t		__tcpi_retransmits;
	uint8_t		__tcpi_probes;
	uint8_t		__tcpi_backoff;
	uint8_t		tcpi_options;		/* Options enabled on conn. */
	uint8_t		tcpi_snd_wscale;	/* RFC1323 send shift value. */
	uint8_t		tcpi_rcv_wscale;	/* RFC1323 recv shift value. */

	uint32_t	tcpi_rto;	   /* Retransmission timeout (usec). */
	uint32_t	__tcpi_ato;
	uint32_t	tcpi_snd_mss;		/* Max segment size for send. */
	uint32_t	tcpi_rcv_mss;		/* Max segment size for recv. */

	uint32_t	__tcpi_unacked;
	uint32_t	__tcpi_sacked;
	uint32_t	__tcpi_lost;
	uint32_t	__tcpi_retrans;
	uint32_t	__tcpi_fackets;

	/* Times; measurements in usecs. */
	uint32_t	tcpi_last_data_sent;	/* since last sent data. */
	uint32_t	tcpi_last_ack_sent;	/* since last sent ack. */
	uint32_t	tcpi_last_data_recv;	/* since last recv data. */
	uint32_t	tcpi_last_ack_recv;	/* since last recv ack. */

	/* Metrics; variable units. */
	uint32_t	__tcpi_pmtu;
	uint32_t	__tcpi_rcv_ssthresh;
	uint32_t	tcpi_rtt;		/* Smoothed RTT in usecs. */
	uint32_t	tcpi_rttvar;		/* RTT variance in usecs. */
	uint32_t	tcpi_snd_ssthresh;	/* Slow start threshold. */
	uint32_t	tcpi_snd_cwnd;		/* Send congestion window. */
	uint32_t	__tcpi_advmss;
	uint32_t	__tcpi_reordering;

	uint32_t	__tcpi_rcv_rtt;
	uint32_t	tcpi_rcv_space;		/* Advertised recv window. */

	/*
	 * Members below this point are only set if process is privileged,
	 * otherwise values will be 0.
	 */

	/* FreeBSD/NetBSD extensions to tcp_info. */
	uint32_t	tcpi_snd_wnd;		/* Advertised send window. */
	uint32_t	tcpi_snd_nxt;		/* Next egress seqno */
	uint32_t	tcpi_rcv_nxt;		/* Next ingress seqno */
	uint32_t	tcpi_toe_tid;		/* HWTID for TOE endpoints */
	uint32_t	tcpi_snd_rexmitpack;	/* Retransmitted packets */
	uint32_t	tcpi_rcv_ooopack;	/* Out-of-order packets */
	uint32_t	tcpi_snd_zerowin;	/* Zero-sized windows sent */

	/* OpenBSD extensions */
	uint32_t	tcpi_rttmin;
	uint32_t	tcpi_max_sndwnd;
	uint32_t	tcpi_rcv_adv;
	uint32_t	tcpi_rcv_up;
	uint32_t	tcpi_snd_una;
	uint32_t	tcpi_snd_up;
	uint32_t	tcpi_snd_wl1;
	uint32_t	tcpi_snd_wl2;
	uint32_t	tcpi_snd_max;
	uint32_t	tcpi_ts_recent;
	uint32_t	tcpi_ts_recent_age;
	uint32_t	tcpi_rfbuf_cnt;
	uint32_t	tcpi_rfbuf_ts;
	uint32_t	tcpi_so_rcv_sb_cc;
	uint32_t	tcpi_so_rcv_sb_hiwat;
	uint32_t	tcpi_so_rcv_sb_lowat;
	uint32_t	tcpi_so_rcv_sb_wat;
	uint32_t	tcpi_so_snd_sb_cc;
	uint32_t	tcpi_so_snd_sb_hiwat;
	uint32_t	tcpi_so_snd_sb_lowat;
	uint32_t	tcpi_so_snd_sb_wat;
};

#endif /* _NETINET_TCP_H_ */