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/*
* Copyright (c) 1985, 1993
* The Regents of the University of California. All rights reserved.
*
* This file includes significant work done at Cornell University by
* Bill Nesheim. That work included by permission.
*
* 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 8.1 (Berkeley) 6/5/93";
#endif /* not lint */
/*
* Routing Table Management Daemon
*/
#include "defs.h"
int timeval = -TIMER_RATE;
/*
* Timer routine. Performs routing information supply
* duties and manages timers on routing table entries.
*/
void
timer()
{
register struct rthash *rh;
register struct rt_entry *rt;
struct rthash *base = hosthash;
int doinghost = 1, timetobroadcast;
timeval += TIMER_RATE;
if (lookforinterfaces && (timeval % CHECK_INTERVAL) == 0)
ifinit();
timetobroadcast = supplier && (timeval % 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 that for our only interface.
* The latter is excused because we don't act as
* a routing information supplier and hence would
* time it out. This is fair as if it's down
* we're cut off from the world anyway and it's
* not likely we'll grow any new hardware in
* the mean time.
*/
if (!(rt->rt_state & RTS_PASSIVE) &&
(supplier || !(rt->rt_state & RTS_INTERFACE)))
rt->rt_timer += TIMER_RATE;
if (rt->rt_timer >= EXPIRE_TIME)
rt->rt_metric = HOPCNT_INFINITY;
if (rt->rt_timer >= GARBAGE_TIME) {
rt = rt->rt_back;
/* Perhaps we should send a REQUEST for this route? */
rtdelete(rt->rt_forw);
continue;
}
if (rt->rt_state & RTS_CHANGED) {
rt->rt_state &= ~RTS_CHANGED;
/* don't send extraneous packets */
if (!supplier || timetobroadcast)
continue;
msg->rip_cmd = htons(RIPCMD_RESPONSE);
msg->rip_nets[0].rip_dst =
(satons_addr(rt->rt_dst)).x_net;
msg->rip_nets[0].rip_metric =
htons(min(rt->rt_metric+1, HOPCNT_INFINITY));
toall(sndmsg);
}
}
}
if (doinghost) {
doinghost = 0;
base = nethash;
goto again;
}
if (timetobroadcast)
toall(supply);
alarm(TIMER_RATE);
}
/*
* On hangup, let everyone know we're going away.
*/
void
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);
}
exit(1);
}
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