tcp_seq.h revision 50477
11541Srgrimes/* 211150Swollman * Copyright (c) 1982, 1986, 1993, 1995 31541Srgrimes * The Regents of the University of California. All rights reserved. 41541Srgrimes * 51541Srgrimes * Redistribution and use in source and binary forms, with or without 61541Srgrimes * modification, are permitted provided that the following conditions 71541Srgrimes * are met: 81541Srgrimes * 1. Redistributions of source code must retain the above copyright 91541Srgrimes * notice, this list of conditions and the following disclaimer. 101541Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 111541Srgrimes * notice, this list of conditions and the following disclaimer in the 121541Srgrimes * documentation and/or other materials provided with the distribution. 131541Srgrimes * 3. All advertising materials mentioning features or use of this software 141541Srgrimes * must display the following acknowledgement: 151541Srgrimes * This product includes software developed by the University of 161541Srgrimes * California, Berkeley and its contributors. 171541Srgrimes * 4. Neither the name of the University nor the names of its contributors 181541Srgrimes * may be used to endorse or promote products derived from this software 191541Srgrimes * without specific prior written permission. 201541Srgrimes * 211541Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 221541Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 231541Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 241541Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 251541Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 261541Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 271541Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 281541Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 291541Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 301541Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 311541Srgrimes * SUCH DAMAGE. 321541Srgrimes * 3311150Swollman * @(#)tcp_seq.h 8.3 (Berkeley) 6/21/95 3450477Speter * $FreeBSD: head/sys/netinet/tcp_seq.h 50477 1999-08-28 01:08:13Z peter $ 351541Srgrimes */ 361541Srgrimes 372169Spaul#ifndef _NETINET_TCP_SEQ_H_ 382169Spaul#define _NETINET_TCP_SEQ_H_ 391541Srgrimes/* 401541Srgrimes * TCP sequence numbers are 32 bit integers operated 411541Srgrimes * on with modular arithmetic. These macros can be 421541Srgrimes * used to compare such integers. 431541Srgrimes */ 441541Srgrimes#define SEQ_LT(a,b) ((int)((a)-(b)) < 0) 451541Srgrimes#define SEQ_LEQ(a,b) ((int)((a)-(b)) <= 0) 461541Srgrimes#define SEQ_GT(a,b) ((int)((a)-(b)) > 0) 471541Srgrimes#define SEQ_GEQ(a,b) ((int)((a)-(b)) >= 0) 481541Srgrimes 496247Swollman/* for modulo comparisons of timestamps */ 506247Swollman#define TSTMP_LT(a,b) ((int)((a)-(b)) < 0) 516247Swollman#define TSTMP_GEQ(a,b) ((int)((a)-(b)) >= 0) 526247Swollman 531541Srgrimes/* 546247Swollman * TCP connection counts are 32 bit integers operated 556247Swollman * on with modular arithmetic. These macros can be 566247Swollman * used to compare such integers. 576247Swollman */ 586247Swollman#define CC_LT(a,b) ((int)((a)-(b)) < 0) 596247Swollman#define CC_LEQ(a,b) ((int)((a)-(b)) <= 0) 606247Swollman#define CC_GT(a,b) ((int)((a)-(b)) > 0) 616247Swollman#define CC_GEQ(a,b) ((int)((a)-(b)) >= 0) 626247Swollman 636247Swollman/* Macro to increment a CC: skip 0 which has a special meaning */ 646247Swollman#define CC_INC(c) (++(c) == 0 ? ++(c) : (c)) 656247Swollman 666247Swollman/* 671541Srgrimes * Macros to initialize tcp sequence numbers for 681541Srgrimes * send and receive from initial send and receive 691541Srgrimes * sequence numbers. 701541Srgrimes */ 711541Srgrimes#define tcp_rcvseqinit(tp) \ 721541Srgrimes (tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1 731541Srgrimes 741541Srgrimes#define tcp_sendseqinit(tp) \ 751541Srgrimes (tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \ 761541Srgrimes (tp)->iss 771541Srgrimes 786247Swollman#define TCP_PAWS_IDLE (24 * 24 * 60 * 60 * PR_SLOWHZ) 796247Swollman /* timestamp wrap-around time */ 806247Swollman 811541Srgrimes#ifdef KERNEL 826348Swollmanextern tcp_cc tcp_ccgen; /* global connection count */ 8311150Swollman 8411150Swollman/* 8511150Swollman * Increment for tcp_iss each second. 8611150Swollman * This is designed to increment at the standard 250 KB/s, 8711150Swollman * but with a random component averaging 128 KB. 8811150Swollman * We also increment tcp_iss by a quarter of this amount 8911150Swollman * each time we use the value for a new connection. 9011150Swollman * If defined, the tcp_random18() macro should produce a 9111150Swollman * number in the range [0-0x3ffff] that is hard to predict. 9211150Swollman */ 9311150Swollman#ifndef tcp_random18 9411150Swollman#define tcp_random18() ((random() >> 14) & 0x3ffff) 951541Srgrimes#endif 9611150Swollman#define TCP_ISSINCR (122*1024 + tcp_random18()) 9711150Swollman 9811150Swollmanextern tcp_seq tcp_iss; /* tcp initial send seq # */ 9911150Swollman#else 10011150Swollman#define TCP_ISSINCR (250*1024) /* increment for tcp_iss each second */ 10111150Swollman#endif /* KERNEL */ 10211150Swollman#endif /* _NETINET_TCP_SEQ_H_ */ 103