1/* SPDX-License-Identifier: BSD-3-Clause */
2/*
3 * Copyright (c) 1982, 1986, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the University nor the names of its contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 * @(#)tcp.h 8.1 (Berkeley) 6/10/93
31 * tcp.h,v 1.3 1994/08/21 05:27:34 paul Exp
32 */
33
34#ifndef TCP_H
35#define TCP_H
36
37#include <glib.h>
38
39typedef uint32_t tcp_seq;
40
41#define PR_SLOWHZ 2 /* 2 slow timeouts per second (approx) */
42#define PR_FASTHZ 5 /* 5 fast timeouts per second (not important) */
43
44#define TCP_SNDSPACE 8192
45#define TCP_RCVSPACE 8192
46
47/*
48 * TCP header.
49 * Per RFC 793, September, 1981.
50 */
51#define tcphdr slirp_tcphdr
52struct tcphdr {
53 uint16_t th_sport; /* source port */
54 uint16_t th_dport; /* destination port */
55 tcp_seq th_seq; /* sequence number */
56 tcp_seq th_ack; /* acknowledgement number */
57#if G_BYTE_ORDER == G_BIG_ENDIAN
58 uint8_t th_off : 4, /* data offset */
59 th_x2 : 4; /* (unused) */
60#else
61 uint8_t th_x2 : 4, /* (unused) */
62 th_off : 4; /* data offset */
63#endif
64 uint8_t th_flags;
65 uint16_t th_win; /* window */
66 uint16_t th_sum; /* checksum */
67 uint16_t th_urp; /* urgent pointer */
68};
69
70#include "tcp_var.h"
71
72#ifndef TH_FIN
73#define TH_FIN 0x01
74#define TH_SYN 0x02
75#define TH_RST 0x04
76#define TH_PUSH 0x08
77#define TH_ACK 0x10
78#define TH_URG 0x20
79#endif
80
81#ifndef TCPOPT_EOL
82#define TCPOPT_EOL 0
83#define TCPOPT_NOP 1
84#define TCPOPT_MAXSEG 2
85#define TCPOPT_WINDOW 3
86#define TCPOPT_SACK_PERMITTED 4 /* Experimental */
87#define TCPOPT_SACK 5 /* Experimental */
88#define TCPOPT_TIMESTAMP 8
89
90#define TCPOPT_TSTAMP_HDR \
91 (TCPOPT_NOP << 24 | TCPOPT_NOP << 16 | TCPOPT_TIMESTAMP << 8 | \
92 TCPOLEN_TIMESTAMP)
93#endif
94
95#ifndef TCPOLEN_MAXSEG
96#define TCPOLEN_MAXSEG 4
97#define TCPOLEN_WINDOW 3
98#define TCPOLEN_SACK_PERMITTED 2
99#define TCPOLEN_TIMESTAMP 10
100#define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP + 2) /* appendix A */
101#endif
102
103/*
104 * Default maximum segment size for TCP.
105 * With an IP MSS of 576, this is 536,
106 * but 512 is probably more convenient.
107 * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)).
108 *
109 * We make this 1460 because we only care about Ethernet in the qemu context.
110 */
111#undef TCP_MSS
112#define TCP_MSS 1460
113#undef TCP6_MSS
114#define TCP6_MSS 1440
115
116#undef TCP_MAXWIN
117#define TCP_MAXWIN 65535 /* largest value for (unscaled) window */
118
119#undef TCP_MAX_WINSHIFT
120#define TCP_MAX_WINSHIFT 14 /* maximum window shift */
121
122/*
123 * User-settable options (used with setsockopt).
124 *
125 * We don't use the system headers on unix because we have conflicting
126 * local structures. We can't avoid the system definitions on Windows,
127 * so we undefine them.
128 */
129#undef TCP_NODELAY
130#define TCP_NODELAY 0x01 /* don't delay send to coalesce packets */
131#undef TCP_MAXSEG
132
133/*
134 * TCP FSM state definitions.
135 * Per RFC793, September, 1981.
136 */
137
138#define TCP_NSTATES 11
139
140#define TCPS_CLOSED 0 /* closed */
141#define TCPS_LISTEN 1 /* listening for connection */
142#define TCPS_SYN_SENT 2 /* active, have sent syn */
143#define TCPS_SYN_RECEIVED 3 /* have send and received syn */
144/* states < TCPS_ESTABLISHED are those where connections not established */
145#define TCPS_ESTABLISHED 4 /* established */
146#define TCPS_CLOSE_WAIT 5 /* rcvd fin, waiting for close */
147/* states > TCPS_CLOSE_WAIT are those where user has closed */
148#define TCPS_FIN_WAIT_1 6 /* have closed, sent fin */
149#define TCPS_CLOSING 7 /* closed xchd FIN; await FIN ACK */
150#define TCPS_LAST_ACK 8 /* had fin and close; await FIN ACK */
151/* states > TCPS_CLOSE_WAIT && < TCPS_FIN_WAIT_2 await ACK of FIN */
152#define TCPS_FIN_WAIT_2 9 /* have closed, fin is acked */
153#define TCPS_TIME_WAIT 10 /* in 2*msl quiet wait after close */
154
155#define TCPS_HAVERCVDSYN(s) ((s) >= TCPS_SYN_RECEIVED)
156#define TCPS_HAVEESTABLISHED(s) ((s) >= TCPS_ESTABLISHED)
157#define TCPS_HAVERCVDFIN(s) ((s) >= TCPS_TIME_WAIT)
158
159/*
160 * TCP sequence numbers are 32 bit integers operated
161 * on with modular arithmetic. These macros can be
162 * used to compare such integers.
163 */
164#define SEQ_LT(a, b) ((int)((a) - (b)) < 0)
165#define SEQ_LEQ(a, b) ((int)((a) - (b)) <= 0)
166#define SEQ_GT(a, b) ((int)((a) - (b)) > 0)
167#define SEQ_GEQ(a, b) ((int)((a) - (b)) >= 0)
168
169/*
170 * Macros to initialize tcp sequence numbers for
171 * send and receive from initial send and receive
172 * sequence numbers.
173 */
174#define tcp_rcvseqinit(tp) (tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
175
176#define tcp_sendseqinit(tp) \
177 (tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = (tp)->iss
178
179#define TCP_ISSINCR (125 * 1024) /* increment for tcp_iss each second */
180
181#endif
182