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

/*
 * Copyright (c) 1983, 1988 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#ifndef lint
static char sccsid[] = "@(#)input.c	5.20 (Berkeley) %G%";
#endif /* not lint */

/*
 * Routing Table Management Daemon
 */
#include "defs.h"
#include <sys/syslog.h>

/*
 * Process a newly received packet.
 */
rip_input(from, rip, size)
	struct sockaddr *from;
	register struct rip *rip;
	int size;
{
	register struct rt_entry *rt;
	register struct netinfo *n;
	register struct interface *ifp;
	struct interface *if_ifwithdstaddr();
	int count, changes = 0;
	register struct afswitch *afp;
	static struct sockaddr badfrom, badfrom2;

	ifp = 0;
	TRACE_INPUT(ifp, from, (char *)rip, size);
	if (from->sa_family >= af_max ||
	    (afp = &afswitch[from->sa_family])->af_hash == (int (*)())0) {
		syslog(LOG_INFO,
	 "\"from\" address in unsupported address family (%d), cmd %d\n",
		    from->sa_family, rip->rip_cmd);
		return;
	}
	if (rip->rip_vers == 0) {
		syslog(LOG_ERR,
		    "RIP version 0 packet received from %s! (cmd %d)",
		    (*afswitch[from->sa_family].af_format)(from), rip->rip_cmd);
		return;
	}
	switch (rip->rip_cmd) {

	case RIPCMD_REQUEST:
		n = rip->rip_nets;
		count = size - ((char *)n - (char *)rip);
		if (count < sizeof (struct netinfo))
			return;
		for (; count > 0; n++) {
			if (count < sizeof (struct netinfo))
				break;
			count -= sizeof (struct netinfo);

#if BSD < 198810
			if (sizeof(n->rip_dst.sa_family) > 1)/* XXX */
				n->rip_dst.sa_family =
					ntohs(n->rip_dst.sa_family);
#endif
			n->rip_metric = ntohl(n->rip_metric);
			/* 
			 * A single entry with sa_family == AF_UNSPEC and
			 * metric ``infinity'' means ``all routes''.
			 * We respond to routers only if we are acting
			 * as a supplier, or to anyone other than a router
			 * (eg, query).
			 */
			if (n->rip_dst.sa_family == AF_UNSPEC &&
			    n->rip_metric == HOPCNT_INFINITY && count == 0) {
			    	if (supplier || (*afp->af_portmatch)(from) == 0)
					supply(from, 0, 0, 0);
				return;
			}
			if (n->rip_dst.sa_family < af_max &&
			    afswitch[n->rip_dst.sa_family].af_hash)
				rt = rtlookup(&n->rip_dst);
			else
				rt = 0;
			n->rip_metric = rt == 0 ? HOPCNT_INFINITY :
				min(rt->rt_metric + 1, HOPCNT_INFINITY);
#if BSD < 198810
			if (sizeof(n->rip_dst.sa_family) > 1)	/* XXX */
			    n->rip_dst.sa_family = htons(n->rip_dst.sa_family);
#endif
			n->rip_metric = htonl(n->rip_metric);
		}
		rip->rip_cmd = RIPCMD_RESPONSE;
		bcopy((char *)rip, packet, size);
		(*afp->af_output)(s, 0, from, size);
		return;

	case RIPCMD_TRACEON:
	case RIPCMD_TRACEOFF:
		/* verify message came from a privileged port */
		if ((*afp->af_portcheck)(from) == 0)
			return;
		if ((ifp = if_iflookup(from)) == 0 || (ifp->int_flags &
		    (IFF_BROADCAST | IFF_POINTOPOINT | IFF_REMOTE)) == 0 ||
		    ifp->int_flags & IFF_PASSIVE) {
			syslog(LOG_ERR, "trace command from unknown router, %s",
			    (*afswitch[from->sa_family].af_format)(from));
			return;
		}
		((char *)rip)[size] = '\0';
		if (rip->rip_cmd == RIPCMD_TRACEON)
			traceon(rip->rip_tracefile);
		else
			traceoff();
		return;

	case RIPCMD_RESPONSE:
		/* verify message came from a router */
		if ((*afp->af_portmatch)(from) == 0)
			return;
		(*afp->af_canon)(from);
		/* are we talking to ourselves? */
		ifp = if_ifwithaddr(from);
		if (ifp) {
			if (ifp->int_flags & IFF_PASSIVE) {
				syslog(LOG_ERR,
				  "bogus input (from passive interface, %s)",
				  (*afswitch[from->sa_family].af_format)(from));
				return;
			}
			rt = rtfind(from);
			if (rt == 0 || ((rt->rt_state & RTS_INTERFACE) == 0) &&
			    rt->rt_metric >= ifp->int_metric) 
				addrouteforif(ifp);
			else
				rt->rt_timer = 0;
			return;
		}
		/*
		 * Update timer for interface on which the packet arrived.
		 * If from other end of a point-to-point link that isn't
		 * in the routing tables, (re-)add the route.
		 */
		if ((rt = rtfind(from)) &&
		    (rt->rt_state & (RTS_INTERFACE | RTS_REMOTE)))
			rt->rt_timer = 0;
		else if ((ifp = if_ifwithdstaddr(from)) &&
		    (rt == 0 || rt->rt_metric >= ifp->int_metric))
			addrouteforif(ifp);
		/*
		 * "Authenticate" router from which message originated.
		 * We accept routing packets from routers directly connected
		 * via broadcast or point-to-point networks,
		 * and from those listed in /etc/gateways.
		 */
		if ((ifp = if_iflookup(from)) == 0 || (ifp->int_flags &
		    (IFF_BROADCAST | IFF_POINTOPOINT | IFF_REMOTE)) == 0 ||
		    ifp->int_flags & IFF_PASSIVE) {
			if (bcmp((char *)from, (char *)&badfrom,
			    sizeof(badfrom)) != 0) {
				syslog(LOG_ERR,
				  "packet from unknown router, %s",
				  (*afswitch[from->sa_family].af_format)(from));
				badfrom = *from;
			}
			return;
		}
		size -= 4 * sizeof (char);
		n = rip->rip_nets;
		for (; size > 0; size -= sizeof (struct netinfo), n++) {
			if (size < sizeof (struct netinfo))
				break;
#if BSD < 198810
			if (sizeof(n->rip_dst.sa_family) > 1)	/* XXX */
				n->rip_dst.sa_family =
					ntohs(n->rip_dst.sa_family);
#endif
			n->rip_metric = ntohl(n->rip_metric);
			if (n->rip_dst.sa_family >= af_max ||
			    (afp = &afswitch[n->rip_dst.sa_family])->af_hash ==
			    (int (*)())0) {
				syslog(LOG_INFO,
		"route in unsupported address family (%d), from %s (af %d)\n",
				   n->rip_dst.sa_family,
				   (*afswitch[from->sa_family].af_format)(from),
				   from->sa_family);
				continue;
			}
			if (((*afp->af_checkhost)(&n->rip_dst)) == 0) {
				syslog(LOG_DEBUG,
				    "bad host in route from %s (af %d)\n",
				   (*afswitch[from->sa_family].af_format)(from),
				   from->sa_family);
				continue;
			}
			if (n->rip_metric == 0 ||
			    (unsigned) n->rip_metric > HOPCNT_INFINITY) {
				if (bcmp((char *)from, (char *)&badfrom2,
				    sizeof(badfrom2)) != 0) {
					syslog(LOG_ERR,
					    "bad metric (%d) from %s\n",
					    n->rip_metric,
				  (*afswitch[from->sa_family].af_format)(from));
					badfrom2 = *from;
				}
				continue;
			}
			/*
			 * Adjust metric according to incoming interface.
			 */
			if ((unsigned) n->rip_metric < HOPCNT_INFINITY)
				n->rip_metric += ifp->int_metric;
			if ((unsigned) n->rip_metric > HOPCNT_INFINITY)
				n->rip_metric = HOPCNT_INFINITY;
			rt = rtlookup(&n->rip_dst);
			if (rt == 0 ||
			    (rt->rt_state & (RTS_INTERNAL|RTS_INTERFACE)) ==
			    (RTS_INTERNAL|RTS_INTERFACE)) {
				/*
				 * If we're hearing a logical network route
				 * back from a peer to which we sent it,
				 * ignore it.
				 */
				if (rt && rt->rt_state & RTS_SUBNET &&
				    (*afp->af_sendroute)(rt, from))
					continue;
				if ((unsigned)n->rip_metric < HOPCNT_INFINITY) {
				    /*
				     * Look for an equivalent route that
				     * includes this one before adding
				     * this route.
				     */
				    rt = rtfind(&n->rip_dst);
				    if (rt && equal(from, &rt->rt_router))
					    continue;
				    rtadd(&n->rip_dst, from, n->rip_metric, 0);
				    changes++;
				}
				continue;
			}

			/*
			 * Update if from gateway and different,
			 * shorter, or equivalent but old route
			 * is getting stale.
			 */
			if (equal(from, &rt->rt_router)) {
				if (n->rip_metric != rt->rt_metric) {
					rtchange(rt, from, n->rip_metric);
					changes++;
					rt->rt_timer = 0;
					if (rt->rt_metric >= HOPCNT_INFINITY)
						rt->rt_timer =
						    GARBAGE_TIME - EXPIRE_TIME;
				} else if (rt->rt_metric < HOPCNT_INFINITY)
					rt->rt_timer = 0;
			} else if ((unsigned) n->rip_metric < rt->rt_metric ||
			    (rt->rt_metric == n->rip_metric &&
			    rt->rt_timer > (EXPIRE_TIME/2) &&
			    (unsigned) n->rip_metric < HOPCNT_INFINITY)) {
				rtchange(rt, from, n->rip_metric);
				changes++;
				rt->rt_timer = 0;
			}
		}
		break;
	}

	/*
	 * If changes have occurred, and if we have not sent a broadcast
	 * recently, send a dynamic update.  This update is sent only
	 * on interfaces other than the one on which we received notice
	 * of the change.  If we are within MIN_WAITTIME of a full update,
	 * don't bother sending; if we just sent a dynamic update
	 * and set a timer (nextbcast), delay until that time.
	 * If we just sent a full update, delay the dynamic update.
	 * Set a timer for a randomized value to suppress additional
	 * dynamic updates until it expires; if we delayed sending
	 * the current changes, set needupdate.
	 */
	if (changes && supplier &&
	   now.tv_sec - lastfullupdate.tv_sec < SUPPLY_INTERVAL-MAX_WAITTIME) {
		u_long delay;
		extern long random();

		if (now.tv_sec - lastbcast.tv_sec >= MIN_WAITTIME &&
		    timercmp(&nextbcast, &now, <)) {
			if (traceactions)
				fprintf(ftrace, "send dynamic update\n");
			toall(supply, RTS_CHANGED, ifp);
			lastbcast = now;
			needupdate = 0;
			nextbcast.tv_sec = 0;
		} else {
			needupdate++;
			if (traceactions)
				fprintf(ftrace, "delay dynamic update\n");
		}
#define RANDOMDELAY()	(MIN_WAITTIME * 1000000 + \
		(u_long)random() % ((MAX_WAITTIME - MIN_WAITTIME) * 1000000))

		if (nextbcast.tv_sec == 0) {
			delay = RANDOMDELAY();
			if (traceactions)
				fprintf(ftrace,
				    "inhibit dynamic update for %d usec\n",
				    delay);
			nextbcast.tv_sec = delay / 1000000;
			nextbcast.tv_usec = delay % 1000000;
			timevaladd(&nextbcast, &now);
			/*
			 * If the next possibly dynamic update
			 * is within MIN_WAITTIME of the next full update,
			 * force the delay past the full update,
			 * or we might send a dynamic update just before
			 * the full update.
			 */
			if (nextbcast.tv_sec > lastfullupdate.tv_sec +
			    SUPPLY_INTERVAL - MIN_WAITTIME)
				nextbcast.tv_sec = lastfullupdate.tv_sec +
				    SUPPLY_INTERVAL + 1;
		}
	}
}
Commit	Line	Data
5ff67f98	1	/*
0f7c421b	2	* Copyright (c) 1983, 1988 Regents of the University of California.
0eb85d71 KB	3	* All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms are permitted
b8c620d6 KB	6	* provided that the above copyright notice and this paragraph are
	7	* duplicated in all such forms and that any documentation,
	8	* advertising materials, and other materials related to such
	9	* distribution and use acknowledge that the software was developed
	10	* by the University of California, Berkeley. The name of the
	11	* University may not be used to endorse or promote products derived
	12	* from this software without specific prior written permission.
	13	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
	14	* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
	15	* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
5ff67f98 DF	16	*/
5ff67f98 DF	17
2e74322d	18	#ifndef lint
787d3210	19	static char sccsid[] = "@(#)input.c 5.20 (Berkeley) %G%";
0eb85d71	20	#endif /* not lint */
2e74322d SL	21
	22	/*
	23	* Routing Table Management Daemon
	24	*/
7fe7fe74	25	#include "defs.h"
17fe297f	26	#include <sys/syslog.h>
2e74322d SL	27
	28	/*
	29	* Process a newly received packet.
	30	*/
787d3210	31	rip_input(from, rip, size)
2e74322d	32	struct sockaddr *from;
787d3210	33	register struct rip *rip;
2e74322d SL	34	int size;
2e74322d SL	35	{
20df59f1 MK	36	register struct rt_entry *rt;
	37	register struct netinfo *n;
	38	register struct interface *ifp;
	39	struct interface *if_ifwithdstaddr();
4033c8f6	40	int count, changes = 0;
20df59f1	41	register struct afswitch *afp;
09b9aef2	42	static struct sockaddr badfrom, badfrom2;
2e74322d SL	43
2e74322d SL	44	ifp = 0;
787d3210	45	TRACE_INPUT(ifp, from, (char *)rip, size);
17fe297f MK	46	if (from->sa_family >= af_max \|\|
	47	(afp = &afswitch[from->sa_family])->af_hash == (int (*)())0) {
	48	syslog(LOG_INFO,
	49	"\"from\" address in unsupported address family (%d), cmd %d\n",
787d3210	50	from->sa_family, rip->rip_cmd);
2e74322d	51	return;
17fe297f	52	}
787d3210	53	if (rip->rip_vers == 0) {
4033c8f6 MK	54	syslog(LOG_ERR,
4033c8f6 MK	55	"RIP version 0 packet received from %s! (cmd %d)",
787d3210	56	(*afswitch[from->sa_family].af_format)(from), rip->rip_cmd);
4033c8f6 MK	57	return;
4033c8f6 MK	58	}
787d3210	59	switch (rip->rip_cmd) {
2e74322d SL	60
2e74322d SL	61	case RIPCMD_REQUEST:
787d3210 MK	62	n = rip->rip_nets;
787d3210 MK	63	count = size - ((char )n - (char )rip);
4033c8f6 MK	64	if (count < sizeof (struct netinfo))
	65	return;
	66	for (; count > 0; n++) {
	67	if (count < sizeof (struct netinfo))
2e74322d	68	break;
4033c8f6	69	count -= sizeof (struct netinfo);
2e74322d	70
4033c8f6 MK	71	#if BSD < 198810
4033c8f6 MK	72	if (sizeof(n->rip_dst.sa_family) > 1)/* XXX */
55d340a4 SL	73	n->rip_dst.sa_family =
55d340a4 SL	74	ntohs(n->rip_dst.sa_family);
4033c8f6 MK	75	#endif
4033c8f6 MK	76	n->rip_metric = ntohl(n->rip_metric);
2e74322d SL	77	/*
	78	* A single entry with sa_family == AF_UNSPEC and
	79	* metric ``infinity'' means ``all routes''.
17fe297f MK	80	* We respond to routers only if we are acting
	81	* as a supplier, or to anyone other than a router
	82	* (eg, query).
2e74322d SL	83	*/
2e74322d SL	84	if (n->rip_dst.sa_family == AF_UNSPEC &&
4033c8f6	85	n->rip_metric == HOPCNT_INFINITY && count == 0) {
17deb420	86	if (supplier \|\| (*afp->af_portmatch)(from) == 0)
4033c8f6	87	supply(from, 0, 0, 0);
2e74322d SL	88	return;
2e74322d SL	89	}
17deb420 MK	90	if (n->rip_dst.sa_family < af_max &&
	91	afswitch[n->rip_dst.sa_family].af_hash)
	92	rt = rtlookup(&n->rip_dst);
	93	else
	94	rt = 0;
2e74322d	95	n->rip_metric = rt == 0 ? HOPCNT_INFINITY :
cdf21aa5	96	min(rt->rt_metric + 1, HOPCNT_INFINITY);
4033c8f6 MK	97	#if BSD < 198810
	98	if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */
	99	n->rip_dst.sa_family = htons(n->rip_dst.sa_family);
	100	#endif
	101	n->rip_metric = htonl(n->rip_metric);
2e74322d	102	}
787d3210 MK	103	rip->rip_cmd = RIPCMD_RESPONSE;
787d3210 MK	104	bcopy((char *)rip, packet, size);
4033c8f6	105	(*afp->af_output)(s, 0, from, size);
2e74322d SL	106	return;
	107
	108	case RIPCMD_TRACEON:
	109	case RIPCMD_TRACEOFF:
b7e4f8be	110	/* verify message came from a privileged port */
2e74322d SL	111	if ((*afp->af_portcheck)(from) == 0)
2e74322d SL	112	return;
71786f50	113	if ((ifp = if_iflookup(from)) == 0 \|\| (ifp->int_flags &
98a1809a MK	114	(IFF_BROADCAST \| IFF_POINTOPOINT \| IFF_REMOTE)) == 0 \|\|
98a1809a MK	115	ifp->int_flags & IFF_PASSIVE) {
09069ad0	116	syslog(LOG_ERR, "trace command from unknown router, %s",
eb39c032	117	(*afswitch[from->sa_family].af_format)(from));
09069ad0 MK	118	return;
09069ad0 MK	119	}
787d3210 MK	120	((char *)rip)[size] = '\0';
	121	if (rip->rip_cmd == RIPCMD_TRACEON)
	122	traceon(rip->rip_tracefile);
2e74322d SL	123	else
	124	traceoff();
	125	return;
	126
	127	case RIPCMD_RESPONSE:
	128	/* verify message came from a router */
	129	if ((*afp->af_portmatch)(from) == 0)
	130	return;
	131	(*afp->af_canon)(from);
	132	/* are we talking to ourselves? */
	133	ifp = if_ifwithaddr(from);
	134	if (ifp) {
0f7c421b MK	135	if (ifp->int_flags & IFF_PASSIVE) {
	136	syslog(LOG_ERR,
	137	"bogus input (from passive interface, %s)",
	138	(*afswitch[from->sa_family].af_format)(from));
	139	return;
	140	}
2e74322d	141	rt = rtfind(from);
7892134c MK	142	if (rt == 0 \|\| ((rt->rt_state & RTS_INTERFACE) == 0) &&
7892134c MK	143	rt->rt_metric >= ifp->int_metric)
2e74322d SL	144	addrouteforif(ifp);
	145	else
	146	rt->rt_timer = 0;
	147	return;
	148	}
f1e15e15 MK	149	/*
	150	* Update timer for interface on which the packet arrived.
	151	* If from other end of a point-to-point link that isn't
	152	* in the routing tables, (re-)add the route.
	153	*/
09069ad0 MK	154	if ((rt = rtfind(from)) &&
09069ad0 MK	155	(rt->rt_state & (RTS_INTERFACE \| RTS_REMOTE)))
b7e4f8be	156	rt->rt_timer = 0;
7892134c MK	157	else if ((ifp = if_ifwithdstaddr(from)) &&
7892134c MK	158	(rt == 0 \|\| rt->rt_metric >= ifp->int_metric))
f1e15e15	159	addrouteforif(ifp);
71786f50 MK	160	/*
	161	* "Authenticate" router from which message originated.
	162	* We accept routing packets from routers directly connected
	163	* via broadcast or point-to-point networks,
	164	* and from those listed in /etc/gateways.
	165	*/
	166	if ((ifp = if_iflookup(from)) == 0 \|\| (ifp->int_flags &
98a1809a MK	167	(IFF_BROADCAST \| IFF_POINTOPOINT \| IFF_REMOTE)) == 0 \|\|
98a1809a MK	168	ifp->int_flags & IFF_PASSIVE) {
eb39c032 MK	169	if (bcmp((char )from, (char )&badfrom,
	170	sizeof(badfrom)) != 0) {
	171	syslog(LOG_ERR,
	172	"packet from unknown router, %s",
	173	(*afswitch[from->sa_family].af_format)(from));
	174	badfrom = *from;
	175	}
09069ad0 MK	176	return;
09069ad0 MK	177	}
2e74322d	178	size -= 4 * sizeof (char);
787d3210	179	n = rip->rip_nets;
2e74322d SL	180	for (; size > 0; size -= sizeof (struct netinfo), n++) {
	181	if (size < sizeof (struct netinfo))
	182	break;
4033c8f6 MK	183	#if BSD < 198810
4033c8f6 MK	184	if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */
55d340a4 SL	185	n->rip_dst.sa_family =
55d340a4 SL	186	ntohs(n->rip_dst.sa_family);
4033c8f6 MK	187	#endif
4033c8f6 MK	188	n->rip_metric = ntohl(n->rip_metric);
17fe297f MK	189	if (n->rip_dst.sa_family >= af_max \|\|
	190	(afp = &afswitch[n->rip_dst.sa_family])->af_hash ==
	191	(int (*)())0) {
	192	syslog(LOG_INFO,
	193	"route in unsupported address family (%d), from %s (af %d)\n",
	194	n->rip_dst.sa_family,
	195	(*afswitch[from->sa_family].af_format)(from),
	196	from->sa_family);
ed36994a	197	continue;
17fe297f MK	198	}
	199	if (((*afp->af_checkhost)(&n->rip_dst)) == 0) {
	200	syslog(LOG_DEBUG,
	201	"bad host in route from %s (af %d)\n",
	202	(*afswitch[from->sa_family].af_format)(from),
	203	from->sa_family);
2e74322d	204	continue;
17fe297f	205	}
09b9aef2 MK	206	if (n->rip_metric == 0 \|\|
	207	(unsigned) n->rip_metric > HOPCNT_INFINITY) {
	208	if (bcmp((char )from, (char )&badfrom2,
	209	sizeof(badfrom2)) != 0) {
	210	syslog(LOG_ERR,
	211	"bad metric (%d) from %s\n",
	212	n->rip_metric,
	213	(*afswitch[from->sa_family].af_format)(from));
	214	badfrom2 = *from;
	215	}
	216	continue;
	217	}
7892134c MK	218	/*
	219	* Adjust metric according to incoming interface.
	220	*/
cdf21aa5	221	if ((unsigned) n->rip_metric < HOPCNT_INFINITY)
7892134c	222	n->rip_metric += ifp->int_metric;
cdf21aa5 MK	223	if ((unsigned) n->rip_metric > HOPCNT_INFINITY)
cdf21aa5 MK	224	n->rip_metric = HOPCNT_INFINITY;
2e74322d	225	rt = rtlookup(&n->rip_dst);
97cb3618 MK	226	if (rt == 0 \|\|
	227	(rt->rt_state & (RTS_INTERNAL\|RTS_INTERFACE)) ==
	228	(RTS_INTERNAL\|RTS_INTERFACE)) {
7892134c MK	229	/*
	230	* If we're hearing a logical network route
	231	* back from a peer to which we sent it,
	232	* ignore it.
	233	*/
	234	if (rt && rt->rt_state & RTS_SUBNET &&
	235	(*afp->af_sendroute)(rt, from))
	236	continue;
0f7c421b MK	237	if ((unsigned)n->rip_metric < HOPCNT_INFINITY) {
	238	/*
	239	* Look for an equivalent route that
	240	* includes this one before adding
	241	* this route.
	242	*/
	243	rt = rtfind(&n->rip_dst);
	244	if (rt && equal(from, &rt->rt_router))
	245	continue;
20df59f1	246	rtadd(&n->rip_dst, from, n->rip_metric, 0);
4033c8f6	247	changes++;
0f7c421b	248	}
2e74322d SL	249	continue;
	250	}
	251
	252	/*
38ca17a8	253	* Update if from gateway and different,
0f7c421b MK	254	* shorter, or equivalent but old route
0f7c421b MK	255	* is getting stale.
2e74322d	256	*/
15e56604	257	if (equal(from, &rt->rt_router)) {
88709531	258	if (n->rip_metric != rt->rt_metric) {
15e56604	259	rtchange(rt, from, n->rip_metric);
4033c8f6	260	changes++;
0f7c421b	261	rt->rt_timer = 0;
7892134c	262	if (rt->rt_metric >= HOPCNT_INFINITY)
88709531 MK	263	rt->rt_timer =
	264	GARBAGE_TIME - EXPIRE_TIME;
	265	} else if (rt->rt_metric < HOPCNT_INFINITY)
585e6328	266	rt->rt_timer = 0;
cdf21aa5	267	} else if ((unsigned) n->rip_metric < rt->rt_metric \|\|
0f7c421b MK	268	(rt->rt_metric == n->rip_metric &&
0f7c421b MK	269	rt->rt_timer > (EXPIRE_TIME/2) &&
cdf21aa5	270	(unsigned) n->rip_metric < HOPCNT_INFINITY)) {
2e74322d	271	rtchange(rt, from, n->rip_metric);
4033c8f6	272	changes++;
2e74322d SL	273	rt->rt_timer = 0;
	274	}
	275	}
4033c8f6 MK	276	break;
	277	}
	278
	279	/*
	280	* If changes have occurred, and if we have not sent a broadcast
	281	* recently, send a dynamic update. This update is sent only
	282	* on interfaces other than the one on which we received notice
	283	* of the change. If we are within MIN_WAITTIME of a full update,
	284	* don't bother sending; if we just sent a dynamic update
	285	* and set a timer (nextbcast), delay until that time.
	286	* If we just sent a full update, delay the dynamic update.
	287	* Set a timer for a randomized value to suppress additional
	288	* dynamic updates until it expires; if we delayed sending
	289	* the current changes, set needupdate.
	290	*/
	291	if (changes && supplier &&
	292	now.tv_sec - lastfullupdate.tv_sec < SUPPLY_INTERVAL-MAX_WAITTIME) {
	293	u_long delay;
	294	extern long random();
	295
	296	if (now.tv_sec - lastbcast.tv_sec >= MIN_WAITTIME &&
	297	timercmp(&nextbcast, &now, <)) {
	298	if (traceactions)
	299	fprintf(ftrace, "send dynamic update\n");
	300	toall(supply, RTS_CHANGED, ifp);
	301	lastbcast = now;
	302	needupdate = 0;
	303	nextbcast.tv_sec = 0;
	304	} else {
	305	needupdate++;
	306	if (traceactions)
	307	fprintf(ftrace, "delay dynamic update\n");
	308	}
	309	#define RANDOMDELAY() (MIN_WAITTIME * 1000000 + \
	310	(u_long)random() % ((MAX_WAITTIME - MIN_WAITTIME) * 1000000))
	311
	312	if (nextbcast.tv_sec == 0) {
	313	delay = RANDOMDELAY();
	314	if (traceactions)
	315	fprintf(ftrace,
	316	"inhibit dynamic update for %d usec\n",
	317	delay);
	318	nextbcast.tv_sec = delay / 1000000;
	319	nextbcast.tv_usec = delay % 1000000;
	320	timevaladd(&nextbcast, &now);
	321	/*
	322	* If the next possibly dynamic update
	323	* is within MIN_WAITTIME of the next full update,
	324	* force the delay past the full update,
	325	* or we might send a dynamic update just before
	326	* the full update.
	327	*/
	328	if (nextbcast.tv_sec > lastfullupdate.tv_sec +
	329	SUPPLY_INTERVAL - MIN_WAITTIME)
	330	nextbcast.tv_sec = lastfullupdate.tv_sec +
	331	SUPPLY_INTERVAL + 1;
	332	}
2e74322d SL	333	}
2e74322d SL	334	}