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