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

/*
 * Copyright (c) 1983, 1988, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * %sccs.include.redist.c%
 */

#ifndef lint
static char sccsid[] = "@(#)input.c	8.1 (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);
#else
#define osa(x) ((struct osockaddr *)(&(x)))
			    n->rip_dst.sa_family =
					ntohs(osa(n->rip_dst)->sa_family);
			    n->rip_dst.sa_len = sizeof(n->rip_dst);
#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;
#define min(a, b) (a < b ? a : b)
			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);
#else
			    osa(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);
#else
			    n->rip_dst.sa_family =
					ntohs(osa(n->rip_dst)->sa_family);
			    n->rip_dst.sa_len = sizeof(n->rip_dst);
#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	/*
b2d6cd51 KB	2	* Copyright (c) 1983, 1988, 1993
b2d6cd51 KB	3	* The Regents of the University of California. All rights reserved.
0eb85d71	4	*
d60d530a	5	* %sccs.include.redist.c%
5ff67f98 DF	6	*/
5ff67f98 DF	7
2e74322d	8	#ifndef lint
b2d6cd51	9	static char sccsid[] = "@(#)input.c 8.1 (Berkeley) %G%";
0eb85d71	10	#endif /* not lint */
2e74322d SL	11
	12	/*
	13	* Routing Table Management Daemon
	14	*/
7fe7fe74	15	#include "defs.h"
17fe297f	16	#include <sys/syslog.h>
2e74322d SL	17
	18	/*
	19	* Process a newly received packet.
	20	*/
787d3210	21	rip_input(from, rip, size)
2e74322d	22	struct sockaddr *from;
787d3210	23	register struct rip *rip;
2e74322d SL	24	int size;
2e74322d SL	25	{
20df59f1 MK	26	register struct rt_entry *rt;
	27	register struct netinfo *n;
	28	register struct interface *ifp;
	29	struct interface *if_ifwithdstaddr();
4033c8f6	30	int count, changes = 0;
20df59f1	31	register struct afswitch *afp;
09b9aef2	32	static struct sockaddr badfrom, badfrom2;
2e74322d SL	33
2e74322d SL	34	ifp = 0;
787d3210	35	TRACE_INPUT(ifp, from, (char *)rip, size);
17fe297f MK	36	if (from->sa_family >= af_max \|\|
	37	(afp = &afswitch[from->sa_family])->af_hash == (int (*)())0) {
	38	syslog(LOG_INFO,
	39	"\"from\" address in unsupported address family (%d), cmd %d\n",
787d3210	40	from->sa_family, rip->rip_cmd);
2e74322d	41	return;
17fe297f	42	}
787d3210	43	if (rip->rip_vers == 0) {
4033c8f6 MK	44	syslog(LOG_ERR,
4033c8f6 MK	45	"RIP version 0 packet received from %s! (cmd %d)",
787d3210	46	(*afswitch[from->sa_family].af_format)(from), rip->rip_cmd);
4033c8f6 MK	47	return;
4033c8f6 MK	48	}
787d3210	49	switch (rip->rip_cmd) {
2e74322d SL	50
2e74322d SL	51	case RIPCMD_REQUEST:
787d3210 MK	52	n = rip->rip_nets;
787d3210 MK	53	count = size - ((char )n - (char )rip);
4033c8f6 MK	54	if (count < sizeof (struct netinfo))
	55	return;
	56	for (; count > 0; n++) {
	57	if (count < sizeof (struct netinfo))
2e74322d	58	break;
4033c8f6	59	count -= sizeof (struct netinfo);
2e74322d	60
4033c8f6	61	#if BSD < 198810
a33a5c17 KS	62	if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */
	63	n->rip_dst.sa_family = ntohs(n->rip_dst.sa_family);
	64	#else
	65	#define osa(x) ((struct osockaddr *)(&(x)))
	66	n->rip_dst.sa_family =
	67	ntohs(osa(n->rip_dst)->sa_family);
	68	n->rip_dst.sa_len = sizeof(n->rip_dst);
4033c8f6 MK	69	#endif
4033c8f6 MK	70	n->rip_metric = ntohl(n->rip_metric);
2e74322d SL	71	/*
	72	* A single entry with sa_family == AF_UNSPEC and
	73	* metric ``infinity'' means ``all routes''.
17fe297f MK	74	* We respond to routers only if we are acting
	75	* as a supplier, or to anyone other than a router
	76	* (eg, query).
2e74322d SL	77	*/
2e74322d SL	78	if (n->rip_dst.sa_family == AF_UNSPEC &&
4033c8f6	79	n->rip_metric == HOPCNT_INFINITY && count == 0) {
17deb420	80	if (supplier \|\| (*afp->af_portmatch)(from) == 0)
4033c8f6	81	supply(from, 0, 0, 0);
2e74322d SL	82	return;
2e74322d SL	83	}
17deb420 MK	84	if (n->rip_dst.sa_family < af_max &&
	85	afswitch[n->rip_dst.sa_family].af_hash)
	86	rt = rtlookup(&n->rip_dst);
	87	else
	88	rt = 0;
a33a5c17	89	#define min(a, b) (a < b ? a : b)
2e74322d	90	n->rip_metric = rt == 0 ? HOPCNT_INFINITY :
cdf21aa5	91	min(rt->rt_metric + 1, HOPCNT_INFINITY);
4033c8f6 MK	92	#if BSD < 198810
	93	if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */
	94	n->rip_dst.sa_family = htons(n->rip_dst.sa_family);
a33a5c17 KS	95	#else
	96	osa(n->rip_dst)->sa_family =
	97	htons(n->rip_dst.sa_family);
4033c8f6 MK	98	#endif
4033c8f6 MK	99	n->rip_metric = htonl(n->rip_metric);
2e74322d	100	}
787d3210 MK	101	rip->rip_cmd = RIPCMD_RESPONSE;
787d3210 MK	102	bcopy((char *)rip, packet, size);
4033c8f6	103	(*afp->af_output)(s, 0, from, size);
2e74322d SL	104	return;
	105
	106	case RIPCMD_TRACEON:
	107	case RIPCMD_TRACEOFF:
b7e4f8be	108	/* verify message came from a privileged port */
2e74322d SL	109	if ((*afp->af_portcheck)(from) == 0)
2e74322d SL	110	return;
71786f50	111	if ((ifp = if_iflookup(from)) == 0 \|\| (ifp->int_flags &
98a1809a MK	112	(IFF_BROADCAST \| IFF_POINTOPOINT \| IFF_REMOTE)) == 0 \|\|
98a1809a MK	113	ifp->int_flags & IFF_PASSIVE) {
09069ad0	114	syslog(LOG_ERR, "trace command from unknown router, %s",
eb39c032	115	(*afswitch[from->sa_family].af_format)(from));
09069ad0 MK	116	return;
09069ad0 MK	117	}
787d3210 MK	118	((char *)rip)[size] = '\0';
	119	if (rip->rip_cmd == RIPCMD_TRACEON)
	120	traceon(rip->rip_tracefile);
2e74322d SL	121	else
	122	traceoff();
	123	return;
	124
	125	case RIPCMD_RESPONSE:
	126	/* verify message came from a router */
	127	if ((*afp->af_portmatch)(from) == 0)
	128	return;
	129	(*afp->af_canon)(from);
	130	/* are we talking to ourselves? */
	131	ifp = if_ifwithaddr(from);
	132	if (ifp) {
0f7c421b MK	133	if (ifp->int_flags & IFF_PASSIVE) {
	134	syslog(LOG_ERR,
	135	"bogus input (from passive interface, %s)",
	136	(*afswitch[from->sa_family].af_format)(from));
	137	return;
	138	}
2e74322d	139	rt = rtfind(from);
7892134c MK	140	if (rt == 0 \|\| ((rt->rt_state & RTS_INTERFACE) == 0) &&
7892134c MK	141	rt->rt_metric >= ifp->int_metric)
2e74322d SL	142	addrouteforif(ifp);
	143	else
	144	rt->rt_timer = 0;
	145	return;
	146	}
f1e15e15 MK	147	/*
	148	* Update timer for interface on which the packet arrived.
	149	* If from other end of a point-to-point link that isn't
	150	* in the routing tables, (re-)add the route.
	151	*/
09069ad0 MK	152	if ((rt = rtfind(from)) &&
09069ad0 MK	153	(rt->rt_state & (RTS_INTERFACE \| RTS_REMOTE)))
b7e4f8be	154	rt->rt_timer = 0;
7892134c MK	155	else if ((ifp = if_ifwithdstaddr(from)) &&
7892134c MK	156	(rt == 0 \|\| rt->rt_metric >= ifp->int_metric))
f1e15e15	157	addrouteforif(ifp);
71786f50 MK	158	/*
	159	* "Authenticate" router from which message originated.
	160	* We accept routing packets from routers directly connected
	161	* via broadcast or point-to-point networks,
	162	* and from those listed in /etc/gateways.
	163	*/
	164	if ((ifp = if_iflookup(from)) == 0 \|\| (ifp->int_flags &
98a1809a MK	165	(IFF_BROADCAST \| IFF_POINTOPOINT \| IFF_REMOTE)) == 0 \|\|
98a1809a MK	166	ifp->int_flags & IFF_PASSIVE) {
eb39c032 MK	167	if (bcmp((char )from, (char )&badfrom,
	168	sizeof(badfrom)) != 0) {
	169	syslog(LOG_ERR,
	170	"packet from unknown router, %s",
	171	(*afswitch[from->sa_family].af_format)(from));
	172	badfrom = *from;
	173	}
09069ad0 MK	174	return;
09069ad0 MK	175	}
2e74322d	176	size -= 4 * sizeof (char);
787d3210	177	n = rip->rip_nets;
2e74322d SL	178	for (; size > 0; size -= sizeof (struct netinfo), n++) {
	179	if (size < sizeof (struct netinfo))
	180	break;
4033c8f6 MK	181	#if BSD < 198810
4033c8f6 MK	182	if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */
55d340a4 SL	183	n->rip_dst.sa_family =
55d340a4 SL	184	ntohs(n->rip_dst.sa_family);
a33a5c17 KS	185	#else
	186	n->rip_dst.sa_family =
	187	ntohs(osa(n->rip_dst)->sa_family);
	188	n->rip_dst.sa_len = sizeof(n->rip_dst);
4033c8f6 MK	189	#endif
4033c8f6 MK	190	n->rip_metric = ntohl(n->rip_metric);
17fe297f MK	191	if (n->rip_dst.sa_family >= af_max \|\|
	192	(afp = &afswitch[n->rip_dst.sa_family])->af_hash ==
	193	(int (*)())0) {
	194	syslog(LOG_INFO,
	195	"route in unsupported address family (%d), from %s (af %d)\n",
	196	n->rip_dst.sa_family,
	197	(*afswitch[from->sa_family].af_format)(from),
	198	from->sa_family);
ed36994a	199	continue;
17fe297f MK	200	}
	201	if (((*afp->af_checkhost)(&n->rip_dst)) == 0) {
	202	syslog(LOG_DEBUG,
	203	"bad host in route from %s (af %d)\n",
	204	(*afswitch[from->sa_family].af_format)(from),
	205	from->sa_family);
2e74322d	206	continue;
17fe297f	207	}
09b9aef2 MK	208	if (n->rip_metric == 0 \|\|
	209	(unsigned) n->rip_metric > HOPCNT_INFINITY) {
	210	if (bcmp((char )from, (char )&badfrom2,
	211	sizeof(badfrom2)) != 0) {
	212	syslog(LOG_ERR,
	213	"bad metric (%d) from %s\n",
	214	n->rip_metric,
	215	(*afswitch[from->sa_family].af_format)(from));
	216	badfrom2 = *from;
	217	}
	218	continue;
	219	}
7892134c MK	220	/*
	221	* Adjust metric according to incoming interface.
	222	*/
cdf21aa5	223	if ((unsigned) n->rip_metric < HOPCNT_INFINITY)
7892134c	224	n->rip_metric += ifp->int_metric;
cdf21aa5 MK	225	if ((unsigned) n->rip_metric > HOPCNT_INFINITY)
cdf21aa5 MK	226	n->rip_metric = HOPCNT_INFINITY;
2e74322d	227	rt = rtlookup(&n->rip_dst);
97cb3618 MK	228	if (rt == 0 \|\|
	229	(rt->rt_state & (RTS_INTERNAL\|RTS_INTERFACE)) ==
	230	(RTS_INTERNAL\|RTS_INTERFACE)) {
7892134c MK	231	/*
	232	* If we're hearing a logical network route
	233	* back from a peer to which we sent it,
	234	* ignore it.
	235	*/
	236	if (rt && rt->rt_state & RTS_SUBNET &&
	237	(*afp->af_sendroute)(rt, from))
	238	continue;
0f7c421b MK	239	if ((unsigned)n->rip_metric < HOPCNT_INFINITY) {
	240	/*
	241	* Look for an equivalent route that
	242	* includes this one before adding
	243	* this route.
	244	*/
	245	rt = rtfind(&n->rip_dst);
	246	if (rt && equal(from, &rt->rt_router))
	247	continue;
20df59f1	248	rtadd(&n->rip_dst, from, n->rip_metric, 0);
4033c8f6	249	changes++;
0f7c421b	250	}
2e74322d SL	251	continue;
	252	}
	253
	254	/*
38ca17a8	255	* Update if from gateway and different,
0f7c421b MK	256	* shorter, or equivalent but old route
0f7c421b MK	257	* is getting stale.
2e74322d	258	*/
15e56604	259	if (equal(from, &rt->rt_router)) {
88709531	260	if (n->rip_metric != rt->rt_metric) {
15e56604	261	rtchange(rt, from, n->rip_metric);
4033c8f6	262	changes++;
0f7c421b	263	rt->rt_timer = 0;
7892134c	264	if (rt->rt_metric >= HOPCNT_INFINITY)
88709531 MK	265	rt->rt_timer =
	266	GARBAGE_TIME - EXPIRE_TIME;
	267	} else if (rt->rt_metric < HOPCNT_INFINITY)
585e6328	268	rt->rt_timer = 0;
cdf21aa5	269	} else if ((unsigned) n->rip_metric < rt->rt_metric \|\|
0f7c421b MK	270	(rt->rt_metric == n->rip_metric &&
0f7c421b MK	271	rt->rt_timer > (EXPIRE_TIME/2) &&
cdf21aa5	272	(unsigned) n->rip_metric < HOPCNT_INFINITY)) {
2e74322d	273	rtchange(rt, from, n->rip_metric);
4033c8f6	274	changes++;
2e74322d SL	275	rt->rt_timer = 0;
	276	}
	277	}
4033c8f6 MK	278	break;
	279	}
	280
	281	/*
	282	* If changes have occurred, and if we have not sent a broadcast
	283	* recently, send a dynamic update. This update is sent only
	284	* on interfaces other than the one on which we received notice
	285	* of the change. If we are within MIN_WAITTIME of a full update,
	286	* don't bother sending; if we just sent a dynamic update
	287	* and set a timer (nextbcast), delay until that time.
	288	* If we just sent a full update, delay the dynamic update.
	289	* Set a timer for a randomized value to suppress additional
	290	* dynamic updates until it expires; if we delayed sending
	291	* the current changes, set needupdate.
	292	*/
	293	if (changes && supplier &&
	294	now.tv_sec - lastfullupdate.tv_sec < SUPPLY_INTERVAL-MAX_WAITTIME) {
	295	u_long delay;
	296	extern long random();
	297
	298	if (now.tv_sec - lastbcast.tv_sec >= MIN_WAITTIME &&
	299	timercmp(&nextbcast, &now, <)) {
	300	if (traceactions)
	301	fprintf(ftrace, "send dynamic update\n");
	302	toall(supply, RTS_CHANGED, ifp);
	303	lastbcast = now;
	304	needupdate = 0;
	305	nextbcast.tv_sec = 0;
	306	} else {
	307	needupdate++;
	308	if (traceactions)
	309	fprintf(ftrace, "delay dynamic update\n");
	310	}
	311	#define RANDOMDELAY() (MIN_WAITTIME * 1000000 + \
	312	(u_long)random() % ((MAX_WAITTIME - MIN_WAITTIME) * 1000000))
	313
	314	if (nextbcast.tv_sec == 0) {
	315	delay = RANDOMDELAY();
	316	if (traceactions)
	317	fprintf(ftrace,
	318	"inhibit dynamic update for %d usec\n",
	319	delay);
	320	nextbcast.tv_sec = delay / 1000000;
	321	nextbcast.tv_usec = delay % 1000000;
	322	timevaladd(&nextbcast, &now);
	323	/*
	324	* If the next possibly dynamic update
	325	* is within MIN_WAITTIME of the next full update,
	326	* force the delay past the full update,
	327	* or we might send a dynamic update just before
	328	* the full update.
	329	*/
	330	if (nextbcast.tv_sec > lastfullupdate.tv_sec +
	331	SUPPLY_INTERVAL - MIN_WAITTIME)
	332	nextbcast.tv_sec = lastfullupdate.tv_sec +
	333	SUPPLY_INTERVAL + 1;
	334	}
2e74322d SL	335	}
2e74322d SL	336	}