BSD 4_3_Net_2 release

[unix-history] / usr / src / sbin / routed / timer.c

/*
* Copyright (c) 1983, 1988 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.
*/

#ifndef lint
static char sccsid[] = "@(#)timer.c     5.10 (Berkeley) 2/28/91";
#endif /* not lint */

/*
* Routing Table Management Daemon
*/
#include "defs.h"

int     faketime;

/*
* Timer routine.  Performs routing information supply
* duties and manages timers on routing table entries.
* Management of the RTS_CHANGED bit assumes that we broadcast
* each time called.
*/
void
timer()
{
       register struct rthash *rh;
       register struct rt_entry *rt;
       struct rthash *base = hosthash;
       int doinghost = 1, timetobroadcast;
       extern int externalinterfaces;

       (void) gettimeofday(&now, (struct timezone *)NULL);
       faketime += TIMER_RATE;
       if (lookforinterfaces && (faketime % CHECK_INTERVAL) == 0)
               ifinit();
       timetobroadcast = supplier && (faketime % SUPPLY_INTERVAL) == 0;
again:
       for (rh = base; rh < &base[ROUTEHASHSIZ]; rh++) {
               rt = rh->rt_forw;
               for (; rt != (struct rt_entry *)rh; rt = rt->rt_forw) {
                       /*
                        * We don't advance time on a routing entry for
                        * a passive gateway, or any interface if we're
                        * not acting as supplier.
                        */
                       if (!(rt->rt_state & RTS_PASSIVE) &&
                           (supplier || !(rt->rt_state & RTS_INTERFACE)))
                               rt->rt_timer += TIMER_RATE;
                       if (rt->rt_timer >= GARBAGE_TIME) {
                               rt = rt->rt_back;
                               rtdelete(rt->rt_forw);
                               continue;
                       }
                       if (rt->rt_timer >= EXPIRE_TIME &&
                           rt->rt_metric < HOPCNT_INFINITY)
                               rtchange(rt, &rt->rt_router, HOPCNT_INFINITY);
                       rt->rt_state &= ~RTS_CHANGED;
               }
       }
       if (doinghost) {
               doinghost = 0;
               base = nethash;
               goto again;
       }
       if (timetobroadcast) {
               toall(supply, 0, (struct interface *)NULL);
               lastbcast = now;
               lastfullupdate = now;
               needupdate = 0;         /* cancel any pending dynamic update */
               nextbcast.tv_sec = 0;
       }
}

/*
* On hangup, let everyone know we're going away.
*/
hup()
{
       register struct rthash *rh;
       register struct rt_entry *rt;
       struct rthash *base = hosthash;
       int doinghost = 1;

       if (supplier) {
again:
               for (rh = base; rh < &base[ROUTEHASHSIZ]; rh++) {
                       rt = rh->rt_forw;
                       for (; rt != (struct rt_entry *)rh; rt = rt->rt_forw)
                               rt->rt_metric = HOPCNT_INFINITY;
               }
               if (doinghost) {
                       doinghost = 0;
                       base = nethash;
                       goto again;
               }
               toall(supply, 0, (struct interface *)NULL);
       }
       exit(1);
}