Return to spp_timer.h CVS log

Up to [Apple XNU] / XNU / bsd / netns

Annotation of XNU/bsd/netns/spp_timer.h, revision 1.1

1.1     ! root        1: /*
        !             2:  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
        !             3:  *
        !             4:  * @APPLE_LICENSE_HEADER_START@
        !             5:  * 
        !             6:  * The contents of this file constitute Original Code as defined in and
        !             7:  * are subject to the Apple Public Source License Version 1.1 (the
        !             8:  * "License").  You may not use this file except in compliance with the
        !             9:  * License.  Please obtain a copy of the License at
        !            10:  * http://www.apple.com/publicsource and read it before using this file.
        !            11:  * 
        !            12:  * This Original Code and all software distributed under the License are
        !            13:  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
        !            14:  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
        !            15:  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
        !            16:  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
        !            17:  * License for the specific language governing rights and limitations
        !            18:  * under the License.
        !            19:  * 
        !            20:  * @APPLE_LICENSE_HEADER_END@
        !            21:  */
        !            22: /*
        !            23:  * Copyright (c) 1982, 1986, 1988, 1993
        !            24:  *     The Regents of the University of California.  All rights reserved.
        !            25:  *
        !            26:  * Redistribution and use in source and binary forms, with or without
        !            27:  * modification, are permitted provided that the following conditions
        !            28:  * are met:
        !            29:  * 1. Redistributions of source code must retain the above copyright
        !            30:  *    notice, this list of conditions and the following disclaimer.
        !            31:  * 2. Redistributions in binary form must reproduce the above copyright
        !            32:  *    notice, this list of conditions and the following disclaimer in the
        !            33:  *    documentation and/or other materials provided with the distribution.
        !            34:  * 3. All advertising materials mentioning features or use of this software
        !            35:  *    must display the following acknowledgement:
        !            36:  *     This product includes software developed by the University of
        !            37:  *     California, Berkeley and its contributors.
        !            38:  * 4. Neither the name of the University nor the names of its contributors
        !            39:  *    may be used to endorse or promote products derived from this software
        !            40:  *    without specific prior written permission.
        !            41:  *
        !            42:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
        !            43:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
        !            44:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
        !            45:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
        !            46:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
        !            47:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
        !            48:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
        !            49:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
        !            50:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
        !            51:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
        !            52:  * SUCH DAMAGE.
        !            53:  *
        !            54:  *     @(#)spp_timer.h 8.1 (Berkeley) 6/10/93
        !            55:  */
        !            56: 
        !            57: /*
        !            58:  * Definitions of the SPP timers.  These timers are counted
        !            59:  * down PR_SLOWHZ times a second.
        !            60:  */
        !            61: #define        SPPT_NTIMERS    4
        !            62: 
        !            63: #define        SPPT_REXMT      0               /* retransmit */
        !            64: #define        SPPT_PERSIST    1               /* retransmit persistance */
        !            65: #define        SPPT_KEEP       2               /* keep alive */
        !            66: #define        SPPT_2MSL       3               /* 2*msl quiet time timer */
        !            67: 
        !            68: /*
        !            69:  * The SPPT_REXMT timer is used to force retransmissions.
        !            70:  * The SPP has the SPPT_REXMT timer set whenever segments
        !            71:  * have been sent for which ACKs are expected but not yet
        !            72:  * received.  If an ACK is received which advances tp->snd_una,
        !            73:  * then the retransmit timer is cleared (if there are no more
        !            74:  * outstanding segments) or reset to the base value (if there
        !            75:  * are more ACKs expected).  Whenever the retransmit timer goes off,
        !            76:  * we retransmit one unacknowledged segment, and do a backoff
        !            77:  * on the retransmit timer.
        !            78:  *
        !            79:  * The SPPT_PERSIST timer is used to keep window size information
        !            80:  * flowing even if the window goes shut.  If all previous transmissions
        !            81:  * have been acknowledged (so that there are no retransmissions in progress),
        !            82:  * and the window is too small to bother sending anything, then we start
        !            83:  * the SPPT_PERSIST timer.  When it expires, if the window is nonzero,
        !            84:  * we go to transmit state.  Otherwise, at intervals send a single byte
        !            85:  * into the peer's window to force him to update our window information.
        !            86:  * We do this at most as often as SPPT_PERSMIN time intervals,
        !            87:  * but no more frequently than the current estimate of round-trip
        !            88:  * packet time.  The SPPT_PERSIST timer is cleared whenever we receive
        !            89:  * a window update from the peer.
        !            90:  *
        !            91:  * The SPPT_KEEP timer is used to keep connections alive.  If an
        !            92:  * connection is idle (no segments received) for SPPTV_KEEP amount of time,
        !            93:  * but not yet established, then we drop the connection.  If the connection
        !            94:  * is established, then we force the peer to send us a segment by sending:
        !            95:  *     <SEQ=SND.UNA-1><ACK=RCV.NXT><CTL=ACK>
        !            96:  * This segment is (deliberately) outside the window, and should elicit
        !            97:  * an ack segment in response from the peer.  If, despite the SPPT_KEEP
        !            98:  * initiated segments we cannot elicit a response from a peer in SPPT_MAXIDLE
        !            99:  * amount of time, then we drop the connection.
        !           100:  */
        !           101: 
        !           102: #define        SPP_TTL         30              /* default time to live for SPP segs */
        !           103: /*
        !           104:  * Time constants.
        !           105:  */
        !           106: #define        SPPTV_MSL       ( 15*PR_SLOWHZ)         /* max seg lifetime */
        !           107: #define        SPPTV_SRTTBASE  0                       /* base roundtrip time;
        !           108:                                                   if 0, no idea yet */
        !           109: #define        SPPTV_SRTTDFLT  (  3*PR_SLOWHZ)         /* assumed RTT if no info */
        !           110: 
        !           111: #define        SPPTV_PERSMIN   (  5*PR_SLOWHZ)         /* retransmit persistance */
        !           112: #define        SPPTV_PERSMAX   ( 60*PR_SLOWHZ)         /* maximum persist interval */
        !           113: 
        !           114: #define        SPPTV_KEEP      ( 75*PR_SLOWHZ)         /* keep alive - 75 secs */
        !           115: #define        SPPTV_MAXIDLE   (  8*SPPTV_KEEP)        /* maximum allowable idle
        !           116:                                                   time before drop conn */
        !           117: 
        !           118: #define        SPPTV_MIN       (  1*PR_SLOWHZ)         /* minimum allowable value */
        !           119: #define        SPPTV_REXMTMAX  ( 64*PR_SLOWHZ)         /* max allowable REXMT value */
        !           120: 
        !           121: #define        SPP_LINGERTIME  120                     /* linger at most 2 minutes */
        !           122: 
        !           123: #define        SPP_MAXRXTSHIFT 12                      /* maximum retransmits */
        !           124: 
        !           125: #ifdef SPPTIMERS
        !           126: char *spptimers[] =
        !           127:     { "REXMT", "PERSIST", "KEEP", "2MSL" };
        !           128: #endif
        !           129: 
        !           130: /*
        !           131:  * Force a time value to be in a certain range.
        !           132:  */
        !           133: #define        SPPT_RANGESET(tv, value, tvmin, tvmax) { \
        !           134:        (tv) = (value); \
        !           135:        if ((tv) < (tvmin)) \
        !           136:                (tv) = (tvmin); \
        !           137:        else if ((tv) > (tvmax)) \
        !           138:                (tv) = (tvmax); \
        !           139: }
        !           140: 
        !           141: #ifdef KERNEL
        !           142: extern int spp_backoff[];
        !           143: #endif

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.