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freebsd/sys/netinet/tcp_seq.h
Paul Saab 6d90faf3d8 Add support for TCP Selective Acknowledgements. The work for this
originated on RELENG_4 and was ported to -CURRENT.

The scoreboarding code was obtained from OpenBSD, and many
of the remaining changes were inspired by OpenBSD, but not
taken directly from there.

You can enable/disable sack using net.inet.tcp.do_sack. You can
also limit the number of sack holes that all senders can have in
the scoreboard with net.inet.tcp.sackhole_limit.

Reviewed by:	gnn
Obtained from:	Yahoo! (Mohan Srinivasan, Jayanth Vijayaraghavan)
2004-06-23 21:04:37 +00:00

84 lines
3.2 KiB
C

/*
* 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
* $FreeBSD$
*/
#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)
#define SEQ_MIN(a, b) ((SEQ_LT(a, b)) ? (a) : (b))
#define SEQ_MAX(a, b) ((SEQ_GT(a, b)) ? (a) : (b))
/* 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)->snd_recover = (tp)->iss
#define TCP_PAWS_IDLE (24 * 24 * 60 * 60 * hz)
/* timestamp wrap-around time */
#ifdef _KERNEL
extern tcp_cc tcp_ccgen; /* global connection count */
#endif /* _KERNEL */
#endif /* _NETINET_TCP_SEQ_H_ */