bsd/netccitt/hd_timer.c

   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) University of British Columbia, 1984
  24  * Copyright (c) 1990, 1993
  25  *      The Regents of the University of California.  All rights reserved.
  26  *
  27  * This code is derived from software contributed to Berkeley by
  28  * the Laboratory for Computation Vision and the Computer Science Department
  29  * of the University of British Columbia.
  30  *
  31  * Redistribution and use in source and binary forms, with or without
  32  * modification, are permitted provided that the following conditions
  33  * are met:
  34  * 1. Redistributions of source code must retain the above copyright
  35  *    notice, this list of conditions and the following disclaimer.
  36  * 2. Redistributions in binary form must reproduce the above copyright
  37  *    notice, this list of conditions and the following disclaimer in the
  38  *    documentation and/or other materials provided with the distribution.
  39  * 3. All advertising materials mentioning features or use of this software
  40  *    must display the following acknowledgement:
  41  *      This product includes software developed by the University of
  42  *      California, Berkeley and its contributors.
  43  * 4. Neither the name of the University nor the names of its contributors
  44  *    may be used to endorse or promote products derived from this software
  45  *    without specific prior written permission.
  46  *
  47  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  48  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  49  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  50  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  51  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  52  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  53  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  54  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  55  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  56  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  57  * SUCH DAMAGE.
  58  *
  59  *      @(#)hd_timer.c  8.1 (Berkeley) 6/10/93
  60  */
  61
  62 #include <sys/param.h>
  63 #include <sys/systm.h>
  64 #include <sys/mbuf.h>
  65 #include <sys/domain.h>
  66 #include <sys/socket.h>
  67 #include <sys/protosw.h>
  68 #include <sys/errno.h>
  69 #include <sys/time.h>
  70 #include <sys/kernel.h>
  71
  72 #include <net/if.h>
  73
  74 #include <netccitt/hdlc.h>
  75 #include <netccitt/hd_var.h>
  76 #include <netccitt/x25.h>
  77
  78 /*
  79  * these can be patched with adb if the
  80  * default values are inappropriate
  81  */
  82
  83 int     hd_t1 = T1;
  84 int     hd_t3 = T3;
  85 int     hd_n2 = N2;
  86
  87 /*
  88  *  HDLC TIMER
  89  *
  90  *  This routine is called every 500ms by the kernel. Decrement timer by this
  91  *  amount - if expired then process the event.
  92  */
  93
  94 hd_timer ()
  95 {
  96         register struct hdcb *hdp;
  97         register int s = splimp ();
  98
  99         for (hdp = hdcbhead; hdp; hdp = hdp->hd_next) {
 100                 if (hdp->hd_rrtimer && (--hdp->hd_rrtimer == 0)) {
 101                         if (hdp->hd_lasttxnr != hdp->hd_vr)
 102                                 hd_writeinternal (hdp, RR, POLLOFF);
 103                 }
 104
 105                 if (!(hdp->hd_timer && --hdp->hd_timer == 0))
 106                         continue;
 107
 108                 switch (hdp->hd_state) {
 109                 case INIT:
 110                 case DISC_SENT:
 111                         hd_writeinternal (hdp, DISC, POLLON);
 112                         break;
 113
 114                 case ABM:
 115                         if (hdp->hd_lastrxnr != hdp->hd_vs) {   /* XXX */
 116                                 hdp->hd_timeouts++;
 117                                 hd_resend_iframe (hdp);
 118                         }
 119                         break;
 120
 121                 case WAIT_SABM:
 122                         hd_writeinternal (hdp, FRMR, POLLOFF);
 123                         if (++hdp->hd_retxcnt == hd_n2) {
 124                                 hdp->hd_retxcnt = 0;
 125                                 hd_writeinternal (hdp, SABM, POLLOFF);
 126                                 hdp->hd_state = WAIT_UA;
 127                         }
 128                         break;
 129
 130                 case DM_SENT:
 131                         if (++hdp->hd_retxcnt == hd_n2) {
 132                                 /* Notify the packet level. */
 133                                 (void) pk_ctlinput (PRC_LINKDOWN, hdp->hd_pkp);
 134                                 hdp->hd_retxcnt = 0;
 135                                 hdp->hd_state = SABM_SENT;
 136                                 hd_writeinternal (hdp, SABM, POLLOFF);
 137                         } else
 138                                 hd_writeinternal (hdp, DM, POLLOFF);
 139                         break;
 140
 141                 case WAIT_UA:
 142                         if (++hdp->hd_retxcnt == hd_n2) {
 143                                 hdp->hd_retxcnt = 0;
 144                                 hd_writeinternal (hdp, DM, POLLOFF);
 145                                 hdp->hd_state = DM_SENT;
 146                         } else
 147                                 hd_writeinternal (hdp, SABM, POLLOFF);
 148                         break;
 149
 150                 case SABM_SENT:
 151                         /* Do this indefinitely. */
 152                         hd_writeinternal (hdp, SABM, POLLON);
 153                         break;
 154
 155                 case DISCONNECTED:
 156                         /*
 157                          * Poll the interface driver flags waiting
 158                          * for the IFF_UP bit to come on.
 159                          */
 160                         if (hdp->hd_ifp->if_flags & IFF_UP)
 161                                 hdp->hd_state = INIT;
 162
 163                 }
 164                 SET_TIMER (hdp);
 165         }
 166
 167         splx (s);
 168 }