129 lines
5.3 KiB
C
129 lines
5.3 KiB
C
/*
|
|
* Copyright (c) 1995, Mike Mitchell
|
|
* Copyright (c) 1982, 1986, 1988, 1993
|
|
* 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.
|
|
* 3. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the University of
|
|
* California, Berkeley and its contributors.
|
|
* 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.
|
|
*
|
|
* @(#)spx_timer.h
|
|
*
|
|
* $Id: spx_timer.h,v 1.4 1995/11/04 09:03:39 julian Exp $
|
|
*/
|
|
|
|
#ifndef _NETIPX_SPX_TIMER_H_
|
|
#define _NETIPX_SPX_TIMER_H_
|
|
|
|
/*
|
|
* Definitions of the SPX timers. These timers are counted
|
|
* down PR_SLOWHZ times a second.
|
|
*/
|
|
#define SPXT_REXMT 0 /* retransmit */
|
|
#define SPXT_PERSIST 1 /* retransmit persistence */
|
|
#define SPXT_KEEP 2 /* keep alive */
|
|
#define SPXT_2MSL 3 /* 2*msl quiet time timer */
|
|
|
|
/*
|
|
* The SPXT_REXMT timer is used to force retransmissions.
|
|
* The SPX has the SPXT_REXMT timer set whenever segments
|
|
* have been sent for which ACKs are expected but not yet
|
|
* received. If an ACK is received which advances tp->snd_una,
|
|
* then the retransmit timer is cleared (if there are no more
|
|
* outstanding segments) or reset to the base value (if there
|
|
* are more ACKs expected). Whenever the retransmit timer goes off,
|
|
* we retransmit one unacknowledged segment, and do a backoff
|
|
* on the retransmit timer.
|
|
*
|
|
* The SPXT_PERSIST timer is used to keep window size information
|
|
* flowing even if the window goes shut. If all previous transmissions
|
|
* have been acknowledged (so that there are no retransmissions in progress),
|
|
* and the window is too small to bother sending anything, then we start
|
|
* the SPXT_PERSIST timer. When it expires, if the window is nonzero,
|
|
* we go to transmit state. Otherwise, at intervals send a single byte
|
|
* into the peer's window to force him to update our window information.
|
|
* We do this at most as often as SPXT_PERSMIN time intervals,
|
|
* but no more frequently than the current estimate of round-trip
|
|
* packet time. The SPXT_PERSIST timer is cleared whenever we receive
|
|
* a window update from the peer.
|
|
*
|
|
* The SPXT_KEEP timer is used to keep connections alive. If an
|
|
* connection is idle (no segments received) for SPXTV_KEEP amount of time,
|
|
* but not yet established, then we drop the connection. If the connection
|
|
* is established, then we force the peer to send us a segment by sending:
|
|
* <SEQ=SND.UNA-1><ACK=RCV.NXT><CTL=ACK>
|
|
* This segment is (deliberately) outside the window, and should elicit
|
|
* an ack segment in response from the peer. If, despite the SPXT_KEEP
|
|
* initiated segments we cannot elicit a response from a peer in SPXT_MAXIDLE
|
|
* amount of time, then we drop the connection.
|
|
*/
|
|
|
|
#define SPX_TTL 30 /* default time to live for SPX segs */
|
|
/*
|
|
* Time constants.
|
|
*/
|
|
#define SPXTV_MSL ( 15*PR_SLOWHZ) /* max seg lifetime */
|
|
#define SPXTV_SRTTBASE 0 /* base roundtrip time;
|
|
if 0, no idea yet */
|
|
#define SPXTV_SRTTDFLT ( 3*PR_SLOWHZ) /* assumed RTT if no info */
|
|
|
|
#define SPXTV_PERSMIN ( 5*PR_SLOWHZ) /* retransmit persistence */
|
|
#define SPXTV_PERSMAX ( 60*PR_SLOWHZ) /* maximum persist interval */
|
|
|
|
#define SPXTV_KEEP ( 75*PR_SLOWHZ) /* keep alive - 75 secs */
|
|
#define SPXTV_MAXIDLE ( 8*SPXTV_KEEP) /* maximum allowable idle
|
|
time before drop conn */
|
|
|
|
#define SPXTV_MIN ( 1*PR_SLOWHZ) /* minimum allowable value */
|
|
#define SPXTV_REXMTMAX ( 64*PR_SLOWHZ) /* max allowable REXMT value */
|
|
|
|
#define SPX_LINGERTIME 120 /* linger at most 2 minutes */
|
|
|
|
#define SPX_MAXRXTSHIFT 12 /* maximum retransmits */
|
|
|
|
#ifdef SPXTIMERS
|
|
char *spxtimers[] =
|
|
{ "REXMT", "PERSIST", "KEEP", "2MSL" };
|
|
#endif
|
|
|
|
/*
|
|
* Force a time value to be in a certain range.
|
|
*/
|
|
#define SPXT_RANGESET(tv, value, tvmin, tvmax) { \
|
|
(tv) = (value); \
|
|
if ((tv) < (tvmin)) \
|
|
(tv) = (tvmin); \
|
|
else if ((tv) > (tvmax)) \
|
|
(tv) = (tvmax); \
|
|
}
|
|
|
|
#ifdef KERNEL
|
|
extern int spx_backoff[];
|
|
#endif
|
|
|
|
#endif
|