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 TCPLP_NETINET_TCP_SEQ_H_
34  #define TCPLP_NETINET_TCP_SEQ_H_
35  
36  #include "../tcplp.h"
37  
38  /*
39   * TCP sequence numbers are 32 bit integers operated
40   * on with modular arithmetic.  These macros can be
41   * used to compare such integers.
42   */
43  #define	SEQ_LT(a,b)	((int)((a)-(b)) < 0)
44  #define	SEQ_LEQ(a,b)	((int)((a)-(b)) <= 0)
45  #define	SEQ_GT(a,b)	((int)((a)-(b)) > 0)
46  #define	SEQ_GEQ(a,b)	((int)((a)-(b)) >= 0)
47  
48  #define	SEQ_MIN(a, b)	((SEQ_LT(a, b)) ? (a) : (b))
49  #define	SEQ_MAX(a, b)	((SEQ_GT(a, b)) ? (a) : (b))
50  
51  /* for modulo comparisons of timestamps */
52  #define TSTMP_LT(a,b)	((int)((a)-(b)) < 0)
53  #define TSTMP_GT(a,b)	((int)((a)-(b)) > 0)
54  #define TSTMP_GEQ(a,b)	((int)((a)-(b)) >= 0)
55  
56  /*
57   * Macros to initialize tcp sequence numbers for
58   * send and receive from initial send and receive
59   * sequence numbers.
60   */
61  #define	tcp_rcvseqinit(tp) \
62  	(tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
63  
64  #define	tcp_sendseqinit(tp) \
65  	(tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \
66  	    (tp)->snd_recover = (tp)->iss
67  
68  /*
69   * Clock macros for RFC 1323 timestamps.
70   */
71  #define	TCP_TS_TO_TICKS(_t)	((_t) * hz / 1000)
72  
73  /* Timestamp wrap-around time, 24 days. */
74  #define TCP_PAWS_IDLE	(24 * 24 * 60 * 60 * 1000)
75  
76  /*
77   * tcp_ts_getticks() in ms, should be 1ms < x < 1000ms according to RFC 1323.
78   * We always use 1ms granularity independent of hz.
79   */
80  static __inline uint32_t
tcp_ts_getticks(void)81  tcp_ts_getticks(void)
82  {
83  	/* samkumar: This used to be implemented using getmicrouptime(). */
84  	return tcplp_sys_get_millis();
85  }
86  
87  #endif /* _NETINET_TCP_SEQ_H_ */
88