FreeBSD/Linux Kernel Cross Reference
sys/netinet/tcp_seq.h
1 /*-
2 * Copyright (c) 1982, 1986, 1993, 1995
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 * 4. 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_seq.h 8.3 (Berkeley) 6/21/95
30 * $FreeBSD$
31 */
32
33 #ifndef _NETINET_TCP_SEQ_H_
34 #define _NETINET_TCP_SEQ_H_
35 /*
36 * TCP sequence numbers are 32 bit integers operated
37 * on with modular arithmetic. These macros can be
38 * used to compare such integers.
39 */
40 #define SEQ_LT(a,b) ((int)((a)-(b)) < 0)
41 #define SEQ_LEQ(a,b) ((int)((a)-(b)) <= 0)
42 #define SEQ_GT(a,b) ((int)((a)-(b)) > 0)
43 #define SEQ_GEQ(a,b) ((int)((a)-(b)) >= 0)
44 #define SEQ_SUB(a,b) ((int)((a)-(b)))
45
46 #define SEQ_MIN(a, b) ((SEQ_LT(a, b)) ? (a) : (b))
47 #define SEQ_MAX(a, b) ((SEQ_GT(a, b)) ? (a) : (b))
48
49 #define WIN_LT(a,b) (ntohs(a) < ntohs(b))
50 #define WIN_LEQ(a,b) (ntohs(a) <= ntohs(b))
51 #define WIN_GT(a,b) (ntohs(a) > ntohs(b))
52 #define WIN_GEQ(a,b) (ntohs(a) >= ntohs(b))
53
54 #define WIN_MIN(a, b) ((WIN_LT(a, b)) ? (a) : (b))
55 #define WIN_MAX(a, b) ((WIN_GT(a, b)) ? (a) : (b))
56
57 /* for modulo comparisons of timestamps */
58 #define TSTMP_LT(a,b) ((int)((a)-(b)) < 0)
59 #define TSTMP_GT(a,b) ((int)((a)-(b)) > 0)
60 #define TSTMP_GEQ(a,b) ((int)((a)-(b)) >= 0)
61
62 /*
63 * Macros to initialize tcp sequence numbers for
64 * send and receive from initial send and receive
65 * sequence numbers.
66 */
67 #define tcp_rcvseqinit(tp) \
68 (tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
69
70 #define tcp_sendseqinit(tp) \
71 (tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \
72 (tp)->snd_recover = (tp)->iss
73
74 #ifdef _KERNEL
75 /*
76 * Clock macros for RFC 1323 timestamps.
77 */
78 #define TCP_TS_TO_TICKS(_t) ((_t) * hz / 1000)
79
80 /* Timestamp wrap-around time, 24 days. */
81 #define TCP_PAWS_IDLE (24 * 24 * 60 * 60 * 1000)
82
83 /*
84 * tcp_ts_getticks() in ms, should be 1ms < x < 1000ms according to RFC 1323.
85 * We always use 1ms granularity independent of hz.
86 */
87 static __inline u_int
88 tcp_ts_getticks(void)
89 {
90 struct timeval tv;
91 u_long ms;
92
93 /*
94 * getmicrouptime() should be good enough for any 1-1000ms granularity.
95 * Do not use getmicrotime() here as it might break nfsroot/tcp.
96 */
97 getmicrouptime(&tv);
98 ms = tv.tv_sec * 1000 + tv.tv_usec / 1000;
99
100 return (ms);
101 }
102 #endif /* _KERNEL */
103
104 #endif /* _NETINET_TCP_SEQ_H_ */
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