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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. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	@(#)tcp.h	8.1 (Berkeley) 6/10/93
34  * tcp.h,v 1.3 1994/08/21 05:27:34 paul Exp
35  */
36 
37 #ifndef _TCP_H_
38 #define _TCP_H_
39 
40 #include "helper.h"
41 
42 typedef	u_int32_t	tcp_seq;
43 
44 #define      PR_SLOWHZ       2               /* 2 slow timeouts per second (approx) */
45 #define      PR_FASTHZ       5               /* 5 fast timeouts per second (not important) */
46 
47 extern int tcp_rcvspace;
48 extern int tcp_sndspace;
49 extern struct socket *tcp_last_so;
50 
51 #define TCP_SNDSPACE 8192
52 #define TCP_RCVSPACE 8192
53 
54 /*
55  * TCP header.
56  * Per RFC 793, September, 1981.
57  */
58 struct tcphdr {
59 	port_t	th_sport;		/* source port */
60 	port_t	th_dport;		/* destination port */
61 	tcp_seq	th_seq;			/* sequence number */
62 	tcp_seq	th_ack;			/* acknowledgement number */
63 #ifdef WORDS_BIGENDIAN
64 	u_int	th_off:4,		/* data offset */
65 		th_x2:4;		/* (unused) */
66 #else
67 	u_int	th_x2:4,		/* (unused) */
68 		th_off:4;		/* data offset */
69 #endif
70 	u_int8_t	th_flags;
71 #define	TH_FIN	0x01
72 #define	TH_SYN	0x02
73 #define	TH_RST	0x04
74 #define	TH_PUSH	0x08
75 #define	TH_ACK	0x10
76 #define	TH_URG	0x20
77 	u_int16_t	th_win;			/* window */
78 	u_int16_t	th_sum;			/* checksum */
79 	u_int16_t	th_urp;			/* urgent pointer */
80 };
81 
82 #include "tcp_var.h"
83 
84 #define	TCPOPT_EOL		0
85 #define	TCPOPT_NOP		1
86 #define	TCPOPT_MAXSEG		2
87 #define    TCPOLEN_MAXSEG		4
88 #define TCPOPT_WINDOW		3
89 #define    TCPOLEN_WINDOW		3
90 #define TCPOPT_SACK_PERMITTED	4		/* Experimental */
91 #define    TCPOLEN_SACK_PERMITTED	2
92 #define TCPOPT_SACK		5		/* Experimental */
93 #define TCPOPT_TIMESTAMP	8
94 #define    TCPOLEN_TIMESTAMP		10
95 #define    TCPOLEN_TSTAMP_APPA		(TCPOLEN_TIMESTAMP+2) /* appendix A */
96 
97 #define TCPOPT_TSTAMP_HDR	\
98     (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)
99 
100 /*
101  * Default maximum segment size for TCP.
102  * With an IP MSS of 576, this is 536,
103  * but 512 is probably more convenient.
104  * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)).
105  *
106  * We make this 1460 because we only care about Ethernet in the qemu context.
107  */
108 #define	TCP_MSS	1460
109 
110 #define	TCP_MAXWIN	65535	/* largest value for (unscaled) window */
111 
112 #define TCP_MAX_WINSHIFT	14	/* maximum window shift */
113 
114 /*
115  * User-settable options (used with setsockopt).
116  */
117 #undef  TCP_NODELAY
118 #define	TCP_NODELAY	0x01	/* don't delay send to coalesce packets */
119 #undef  TCP_MAXSEG
120 /* #define	TCP_MAXSEG	0x02 */	/* set maximum segment size */
121 
122 /*
123  * TCP FSM state definitions.
124  * Per RFC793, September, 1981.
125  */
126 
127 #define TCP_NSTATES     11
128 
129 #define TCPS_CLOSED             0       /* closed */
130 #define TCPS_LISTEN             1       /* listening for connection */
131 #define TCPS_SYN_SENT           2       /* active, have sent syn */
132 #define TCPS_SYN_RECEIVED       3       /* have send and received syn */
133 /* states < TCPS_ESTABLISHED are those where connections not established */
134 #define TCPS_ESTABLISHED        4       /* established */
135 #define TCPS_CLOSE_WAIT         5       /* rcvd fin, waiting for close */
136 /* states > TCPS_CLOSE_WAIT are those where user has closed */
137 #define TCPS_FIN_WAIT_1         6       /* have closed, sent fin */
138 #define TCPS_CLOSING            7       /* closed xchd FIN; await FIN ACK */
139 #define TCPS_LAST_ACK           8       /* had fin and close; await FIN ACK */
140 /* states > TCPS_CLOSE_WAIT && < TCPS_FIN_WAIT_2 await ACK of FIN */
141 #define TCPS_FIN_WAIT_2         9       /* have closed, fin is acked */
142 #define TCPS_TIME_WAIT          10      /* in 2*msl quiet wait after close */
143 
144 #define TCPS_HAVERCVDSYN(s)     ((s) >= TCPS_SYN_RECEIVED)
145 #define TCPS_HAVEESTABLISHED(s) ((s) >= TCPS_ESTABLISHED)
146 #define TCPS_HAVERCVDFIN(s)     ((s) >= TCPS_TIME_WAIT)
147 
148 /*
149  * TCP sequence numbers are 32 bit integers operated
150  * on with modular arithmetic.  These macros can be
151  * used to compare such integers.
152  */
153 #define SEQ_LT(a,b)     ((int)((a)-(b)) < 0)
154 #define SEQ_LEQ(a,b)    ((int)((a)-(b)) <= 0)
155 #define SEQ_GT(a,b)     ((int)((a)-(b)) > 0)
156 #define SEQ_GEQ(a,b)    ((int)((a)-(b)) >= 0)
157 
158 /*
159  * Macros to initialize tcp sequence numbers for
160  * send and receive from initial send and receive
161  * sequence numbers.
162  */
163 #define tcp_rcvseqinit(tp) \
164      (tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
165 
166 #define tcp_sendseqinit(tp) \
167     (tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = (tp)->iss
168 
169 #define TCP_ISSINCR     (125*1024)      /* increment for tcp_iss each second */
170 
171 extern tcp_seq tcp_iss;                /* tcp initial send seq # */
172 
173 extern char *tcpstates[];
174 
175 #endif
176