Watt-32 tcp/ip  2.2 dev-rel.10
tcp_seq.h
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1 
5 /*
6  * Copyright (c) 1982, 1986, 1993, 1995
7  * The Regents of the University of California. All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  * notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  * notice, this list of conditions and the following disclaimer in the
16  * documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  * must display the following acknowledgement:
19  * This product includes software developed by the University of
20  * California, Berkeley and its contributors.
21  * 4. Neither the name of the University nor the names of its contributors
22  * may be used to endorse or promote products derived from this software
23  * without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  * @(#)tcp_seq.h 8.3 (Berkeley) 6/21/95
38  * $Id: tcp_seq.h,v 1.6 1995/10/03 16:54:14 wollman Exp $
39  */
40 
41 #ifndef __NETINET_TCP_SEQ_H
42 #define __NETINET_TCP_SEQ_H
43 
44 /*
45  * TCP sequence numbers are 32 bit integers operated
46  * on with modular arithmetic. These macros can be
47  * used to compare such integers.
48  */
49 #define SEQ_LT(a,b) ((long)((a)-(b)) < 0)
50 #define SEQ_LEQ(a,b) ((long)((a)-(b)) <= 0)
51 #define SEQ_GT(a,b) ((long)((a)-(b)) > 0)
52 #define SEQ_GEQ(a,b) ((long)((a)-(b)) >= 0)
53 
54 /* for modulo comparisons of timestamps */
55 #define TSTMP_LT(a,b) ((long)((a)-(b)) < 0)
56 #define TSTMP_GEQ(a,b) ((long)((a)-(b)) >= 0)
57 
58 /*
59  * TCP connection counts are 32 bit integers operated
60  * on with modular arithmetic. These macros can be
61  * used to compare such integers.
62  */
63 #define CC_LT(a,b) ((long)((a)-(b)) < 0)
64 #define CC_LEQ(a,b) ((long)((a)-(b)) <= 0)
65 #define CC_GT(a,b) ((long)((a)-(b)) > 0)
66 #define CC_GEQ(a,b) ((long)((a)-(b)) >= 0)
67 
68 /* Macro to increment a CC: skip 0 which has a special meaning */
69 #define CC_INC(c) (++(c) == 0 ? ++(c) : (c))
70 
71 /*
72  * Macros to initialize tcp sequence numbers for
73  * send and receive from initial send and receive
74  * sequence numbers.
75  */
76 #define tcp_rcvseqinit(tp) \
77  (tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
78 
79 #if defined(TCP_SACK)
80 #define tcp_sendseqinit(tp) \
81  (tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \
82  (tp)->recover = (tp)->sb.last_ack = (tp)->iss
83 
84 #elif defined(TCP_FACK)
85 #define tcp_sendseqinit(tp) \
86  (tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \
87  (tp)->recover = (tp)->scrb.last_ack = (tp)->snd_fack = (tp)->iss
88 
89 #else
90 #define tcp_sendseqinit(tp) \
91  (tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \
92  (tp)->iss
93 #endif
94 
95 #define TCP_PAWS_IDLE (24 * 24 * 60 * 60 * PR_SLOWHZ)
96  /* timestamp wrap-around time */
97 
98 #define TCP_ISSINCR (125*1024) /* increment for tcp_iss each second */
99 
100 #ifdef _KERNEL
101 tcp_seq tcp_iss; /* tcp initial send seq # */
102 #endif
103 
104 #endif