| 1 | /* Modified for gcc/os2 by bird 2003
|
|---|
| 2 | *
|
|---|
| 3 | * Copyright (c) 1982, 1986, 1993
|
|---|
| 4 | * The Regents of the University of California. All rights reserved.
|
|---|
| 5 | *
|
|---|
| 6 | * Redistribution and use in source and binary forms, with or without
|
|---|
| 7 | * modification, are permitted provided that the following conditions
|
|---|
| 8 | * are met:
|
|---|
| 9 | * 1. Redistributions of source code must retain the above copyright
|
|---|
| 10 | * notice, this list of conditions and the following disclaimer.
|
|---|
| 11 | * 2. Redistributions in binary form must reproduce the above copyright
|
|---|
| 12 | * notice, this list of conditions and the following disclaimer in the
|
|---|
| 13 | * documentation and/or other materials provided with the distribution.
|
|---|
| 14 | * 3. All advertising materials mentioning features or use of this software
|
|---|
| 15 | * must display the following acknowledgement:
|
|---|
| 16 | * This product includes software developed by the University of
|
|---|
| 17 | * California, Berkeley and its contributors.
|
|---|
| 18 | * 4. Neither the name of the University nor the names of its contributors
|
|---|
| 19 | * may be used to endorse or promote products derived from this software
|
|---|
| 20 | * without specific prior written permission.
|
|---|
| 21 | *
|
|---|
| 22 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|---|
| 23 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|---|
| 24 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|---|
| 25 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|---|
| 26 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|---|
| 27 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|---|
| 28 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|---|
| 29 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|---|
| 30 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|---|
| 31 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|---|
| 32 | * SUCH DAMAGE.
|
|---|
| 33 | *
|
|---|
| 34 | * @(#)tcp_timer.h 8.1 (Berkeley) 6/10/93
|
|---|
| 35 | * $FreeBSD: src/sys/netinet/tcp_timer.h,v 1.18.2.1 2002/08/16 22:16:39 dillon Exp $
|
|---|
| 36 | */
|
|---|
| 37 |
|
|---|
| 38 | #ifndef _NETINET_TCP_TIMER_H_
|
|---|
| 39 | #define _NETINET_TCP_TIMER_H_
|
|---|
| 40 | #ifndef TCPV40HDRS
|
|---|
| 41 |
|
|---|
| 42 | /*
|
|---|
| 43 | * The TCPT_REXMT timer is used to force retransmissions.
|
|---|
| 44 | * The TCP has the TCPT_REXMT timer set whenever segments
|
|---|
| 45 | * have been sent for which ACKs are expected but not yet
|
|---|
| 46 | * received. If an ACK is received which advances tp->snd_una,
|
|---|
| 47 | * then the retransmit timer is cleared (if there are no more
|
|---|
| 48 | * outstanding segments) or reset to the base value (if there
|
|---|
| 49 | * are more ACKs expected). Whenever the retransmit timer goes off,
|
|---|
| 50 | * we retransmit one unacknowledged segment, and do a backoff
|
|---|
| 51 | * on the retransmit timer.
|
|---|
| 52 | *
|
|---|
| 53 | * The TCPT_PERSIST timer is used to keep window size information
|
|---|
| 54 | * flowing even if the window goes shut. If all previous transmissions
|
|---|
| 55 | * have been acknowledged (so that there are no retransmissions in progress),
|
|---|
| 56 | * and the window is too small to bother sending anything, then we start
|
|---|
| 57 | * the TCPT_PERSIST timer. When it expires, if the window is nonzero,
|
|---|
| 58 | * we go to transmit state. Otherwise, at intervals send a single byte
|
|---|
| 59 | * into the peer's window to force him to update our window information.
|
|---|
|
|---|
