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Diffstat (limited to 'include/netinet/tcp_seq.h')
-rw-r--r-- | include/netinet/tcp_seq.h | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/include/netinet/tcp_seq.h b/include/netinet/tcp_seq.h new file mode 100644 index 0000000000..c24b294250 --- /dev/null +++ b/include/netinet/tcp_seq.h @@ -0,0 +1,99 @@ +/* + * Copyright (c) 1982, 1986, 1993, 1995 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * @(#)tcp_seq.h 8.3 (Berkeley) 6/21/95 + * $FreeBSD: src/sys/netinet/tcp_seq.h,v 1.26 2006/06/18 14:24:12 andre Exp $ + */ + + +#ifndef _NETINET_TCP_SEQ_H_ +#define _NETINET_TCP_SEQ_H_ +/* + * TCP sequence numbers are 32 bit integers operated + * on with modular arithmetic. These macros can be + * used to compare such integers. + */ +#define SEQ_LT(a,b) ((int)((a)-(b)) < 0) +#define SEQ_LEQ(a,b) ((int)((a)-(b)) <= 0) +#define SEQ_GT(a,b) ((int)((a)-(b)) > 0) +#define SEQ_GEQ(a,b) ((int)((a)-(b)) >= 0) + +/* for modulo comparisons of timestamps */ +#define TSTMP_LT(a,b) ((int)((a)-(b)) < 0) +#define TSTMP_GEQ(a,b) ((int)((a)-(b)) >= 0) + +/* + * TCP connection counts are 32 bit integers operated + * on with modular arithmetic. These macros can be + * used to compare such integers. + */ +#define CC_LT(a,b) ((int)((a)-(b)) < 0) +#define CC_LEQ(a,b) ((int)((a)-(b)) <= 0) +#define CC_GT(a,b) ((int)((a)-(b)) > 0) +#define CC_GEQ(a,b) ((int)((a)-(b)) >= 0) + +/* Macro to increment a CC: skip 0 which has a special meaning */ +#define CC_INC(c) (++(c) == 0 ? ++(c) : (c)) + +/* + * Macros to initialize tcp sequence numbers for + * send and receive from initial send and receive + * sequence numbers. + */ +#define tcp_rcvseqinit(tp) \ + (tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1 + +#define tcp_sendseqinit(tp) \ + (tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \ + (tp)->iss + +#define TCP_PAWS_IDLE (uint32_t)(24L * 24L * 60L * 60L * PR_SLOWHZ) + /* timestamp wrap-around time */ + +#ifdef _KERNEL +extern tcp_cc tcp_ccgen; /* global connection count */ + +/* + * Increment for tcp_iss each second. + * This is designed to increment at the standard 250 KB/s, + * but with a random component averaging 128 KB. + * We also increment tcp_iss by a quarter of this amount + * each time we use the value for a new connection. + * If defined, the tcp_random18() macro should produce a + * number in the range [0-0x3ffff] that is hard to predict. + */ +#ifndef tcp_random18 +#define tcp_random18() (((uint32_t)random() >> 14) & 0x3ffffL) +#endif +#define TCP_ISSINCR (uint32_t)(122L*1024L + tcp_random18()) + +extern tcp_seq tcp_iss; /* tcp initial send seq # */ +#else +#define TCP_ISSINCR (250*1024) /* increment for tcp_iss each second */ +#endif /* _KERNEL */ +#endif /* _NETINET_TCP_SEQ_H_ */ |