tcp_seq.h revision 256281
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: stable/10/sys/netinet/tcp_seq.h 231767 2012-02-15 16:09:56Z bz $ 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 45#define SEQ_MIN(a, b) ((SEQ_LT(a, b)) ? (a) : (b)) 46#define SEQ_MAX(a, b) ((SEQ_GT(a, b)) ? (a) : (b)) 47 48/* for modulo comparisons of timestamps */ 49#define TSTMP_LT(a,b) ((int)((a)-(b)) < 0) 50#define TSTMP_GT(a,b) ((int)((a)-(b)) > 0) 51#define TSTMP_GEQ(a,b) ((int)((a)-(b)) >= 0) 52 53/* 54 * Macros to initialize tcp sequence numbers for 55 * send and receive from initial send and receive 56 * sequence numbers. 57 */ 58#define tcp_rcvseqinit(tp) \ 59 (tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1 60 61#define tcp_sendseqinit(tp) \ 62 (tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \ 63 (tp)->snd_recover = (tp)->iss 64 65#ifdef _KERNEL 66/* 67 * Clock macros for RFC 1323 timestamps. 68 */ 69#define TCP_TS_TO_TICKS(_t) ((_t) * hz / 1000) 70 71/* Timestamp wrap-around time, 24 days. */ 72#define TCP_PAWS_IDLE (24 * 24 * 60 * 60 * 1000) 73 74/* 75 * tcp_ts_getticks() in ms, should be 1ms < x < 1000ms according to RFC 1323. 76 * We always use 1ms granularity independent of hz. 77 */ 78static __inline u_int 79tcp_ts_getticks(void) 80{ 81 struct timeval tv; 82 u_long ms; 83 84 /* 85 * getmicrouptime() should be good enough for any 1-1000ms granularity. 86 * Do not use getmicrotime() here as it might break nfsroot/tcp. 87 */ 88 getmicrouptime(&tv); 89 ms = tv.tv_sec * 1000 + tv.tv_usec / 1000; 90 91 return (ms); 92} 93#endif /* _KERNEL */ 94 95#endif /* _NETINET_TCP_SEQ_H_ */ 96