[apple/network_cmds.git] / routed.tproj / input.c

/*
 * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * Copyright (c) 1983, 1988, 1993
 *	The 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 acknowledgment:
 *	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.
 *
 *	@(#)defs.h	8.1 (Berkeley) 6/5/93
 */


/*
 * 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;
		memmove(packet, rip, 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 (memcmp(from, &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 (memcmp(from, &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
b7080c8e A	1	/*
	2	* Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
07f47057 A	6	* Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
	7	*
	8	* This file contains Original Code and/or Modifications of Original Code
	9	* as defined in and that are subject to the Apple Public Source License
	10	* Version 2.0 (the 'License'). You may not use this file except in
	11	* compliance with the License. Please obtain a copy of the License at
	12	* http://www.opensource.apple.com/apsl/ and read it before using this
	13	* file.
b7080c8e A	14	*
	15	* The Original Code and all software distributed under the License are
	16	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	17	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	18	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
07f47057 A	19	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	20	* Please see the License for the specific language governing rights and
	21	* limitations under the License.
b7080c8e A	22	*
	23	* @APPLE_LICENSE_HEADER_END@
	24	*/
	25	/*
	26	* Copyright (c) 1983, 1988, 1993
	27	* The Regents of the University of California. All rights reserved.
	28	*
	29	* Redistribution and use in source and binary forms, with or without
	30	* modification, are permitted provided that the following conditions
	31	* are met:
	32	* 1. Redistributions of source code must retain the above copyright
	33	* notice, this list of conditions and the following disclaimer.
	34	* 2. Redistributions in binary form must reproduce the above copyright
	35	* notice, this list of conditions and the following disclaimer in the
	36	* documentation and/or other materials provided with the distribution.
	37	* 3. All advertising materials mentioning features or use of this software
	38	* must display the following acknowledgment:
	39	* This product includes software developed by the University of
	40	* California, Berkeley and its contributors.
	41	* 4. Neither the name of the University nor the names of its contributors
	42	* may be used to endorse or promote products derived from this software
	43	* without specific prior written permission.
	44	*
	45	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	46	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	47	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	48	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	49	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	50	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	51	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	52	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	53	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	54	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	55	* SUCH DAMAGE.
	56	*
	57	* @(#)defs.h 8.1 (Berkeley) 6/5/93
	58	*/
	59
	60
	61	/*
	62	* Routing Table Management Daemon
	63	*/
	64	#include "defs.h"
	65	#include <sys/syslog.h>
	66
	67	/*
	68	* Process a newly received packet.
	69	*/
	70	rip_input(from, rip, size)
	71	struct sockaddr *from;
	72	register struct rip *rip;
	73	int size;
	74	{
	75	register struct rt_entry *rt;
	76	register struct netinfo *n;
	77	register struct interface *ifp;
	78	struct interface *if_ifwithdstaddr();
	79	int count, changes = 0;
	80	register struct afswitch *afp;
	81	static struct sockaddr badfrom, badfrom2;
	82
	83	ifp = 0;
	84	TRACE_INPUT(ifp, from, (char *)rip, size);
	85	if (from->sa_family >= af_max \|\|
86	(afp = &afswitch[from->sa_family])->af_hash == (int (*)())0) {
87	syslog(LOG_INFO,
88	"\"from\" address in unsupported address family (%d), cmd %d\n",
89	from->sa_family, rip->rip_cmd);
90	return;
91	}
92	if (rip->rip_vers == 0) {
93	syslog(LOG_ERR,
94	"RIP version 0 packet received from %s! (cmd %d)",
95	(*afswitch[from->sa_family].af_format)(from), rip->rip_cmd);
96	return;
97	}
98	switch (rip->rip_cmd) {
99
100	case RIPCMD_REQUEST:
101	n = rip->rip_nets;
102	count = size - ((char )n - (char )rip);
103	if (count < sizeof (struct netinfo))
104	return;
105	for (; count > 0; n++) {
106	if (count < sizeof (struct netinfo))
107	break;
108	count -= sizeof (struct netinfo);
109
110	#if BSD < 198810
111	if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */
112	n->rip_dst.sa_family = ntohs(n->rip_dst.sa_family);
113	#else
114	#define osa(x) ((struct osockaddr *)(&(x)))
115	n->rip_dst.sa_family =
116	ntohs(osa(n->rip_dst)->sa_family);
117	n->rip_dst.sa_len = sizeof(n->rip_dst);
118	#endif
119	n->rip_metric = ntohl(n->rip_metric);
120	/*
121	* A single entry with sa_family == AF_UNSPEC and
122	* metric ``infinity'' means ``all routes''.
123	* We respond to routers only if we are acting
124	* as a supplier, or to anyone other than a router
125	* (eg, query).
126	*/
127	if (n->rip_dst.sa_family == AF_UNSPEC &&
128	n->rip_metric == HOPCNT_INFINITY && count == 0) {
129	if (supplier \|\| (*afp->af_portmatch)(from) == 0)
130	supply(from, 0, 0, 0);
131	return;
132	}
133	if (n->rip_dst.sa_family < af_max &&
134	afswitch[n->rip_dst.sa_family].af_hash)
135	rt = rtlookup(&n->rip_dst);
136	else
137	rt = 0;
138	#define min(a, b) (a < b ? a : b)
139	n->rip_metric = rt == 0 ? HOPCNT_INFINITY :
140	min(rt->rt_metric + 1, HOPCNT_INFINITY);
141	#if BSD < 198810
142	if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */
143	n->rip_dst.sa_family = htons(n->rip_dst.sa_family);
144	#else
145	osa(n->rip_dst)->sa_family =
146	htons(n->rip_dst.sa_family);
147	#endif
148	n->rip_metric = htonl(n->rip_metric);
149	}
150	rip->rip_cmd = RIPCMD_RESPONSE;
151	memmove(packet, rip, size);
152	(*afp->af_output)(s, 0, from, size);
153	return;
154
155	case RIPCMD_TRACEON:
156	case RIPCMD_TRACEOFF:
157	/* verify message came from a privileged port */
158	if ((*afp->af_portcheck)(from) == 0)
159	return;
160	if ((ifp = if_iflookup(from)) == 0 \|\| (ifp->int_flags &
161	(IFF_BROADCAST \| IFF_POINTOPOINT \| IFF_REMOTE)) == 0 \|\|
162	ifp->int_flags & IFF_PASSIVE) {
163	syslog(LOG_ERR, "trace command from unknown router, %s",
164	(*afswitch[from->sa_family].af_format)(from));
165	return;
166	}
167	((char *)rip)[size] = '\0';
168	if (rip->rip_cmd == RIPCMD_TRACEON)
169	traceon(rip->rip_tracefile);
170	else
171	traceoff();
172	return;
173
174	case RIPCMD_RESPONSE:
175	/* verify message came from a router */
176	if ((*afp->af_portmatch)(from) == 0)
177	return;
178	(*afp->af_canon)(from);
179	/* are we talking to ourselves? */
180	ifp = if_ifwithaddr(from);
181	if (ifp) {
182	if (ifp->int_flags & IFF_PASSIVE) {
183	syslog(LOG_ERR,
184	"bogus input (from passive interface, %s)",
185	(*afswitch[from->sa_family].af_format)(from));
186	return;
187	}
188	rt = rtfind(from);
189	if (rt == 0 \|\| ((rt->rt_state & RTS_INTERFACE) == 0) &&
190	rt->rt_metric >= ifp->int_metric)
191	addrouteforif(ifp);
192	else
193	rt->rt_timer = 0;
194	return;
195	}
196	/*
197	* Update timer for interface on which the packet arrived.
198	* If from other end of a point-to-point link that isn't
199	* in the routing tables, (re-)add the route.
200	*/
201	if ((rt = rtfind(from)) &&
202	(rt->rt_state & (RTS_INTERFACE \| RTS_REMOTE)))
203	rt->rt_timer = 0;
204	else if ((ifp = if_ifwithdstaddr(from)) &&
205	(rt == 0 \|\| rt->rt_metric >= ifp->int_metric))
206	addrouteforif(ifp);
207	/*
208	* "Authenticate" router from which message originated.
209	* We accept routing packets from routers directly connected
210	* via broadcast or point-to-point networks,
211	* and from those listed in /etc/gateways.
212	*/
213	if ((ifp = if_iflookup(from)) == 0 \|\| (ifp->int_flags &
214	(IFF_BROADCAST \| IFF_POINTOPOINT \| IFF_REMOTE)) == 0 \|\|
215	ifp->int_flags & IFF_PASSIVE) {
216	if (memcmp(from, &badfrom, sizeof(badfrom)) != 0) {
217	syslog(LOG_ERR,
218	"packet from unknown router, %s",
219	(*afswitch[from->sa_family].af_format)(from));
220	badfrom = *from;
221	}
222	return;
223	}
224	size -= 4 * sizeof (char);
225	n = rip->rip_nets;
226	for (; size > 0; size -= sizeof (struct netinfo), n++) {
227	if (size < sizeof (struct netinfo))
228	break;
229	#if BSD < 198810
230	if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */
231	n->rip_dst.sa_family =
232	ntohs(n->rip_dst.sa_family);
233	#else
234	n->rip_dst.sa_family =
235	ntohs(osa(n->rip_dst)->sa_family);
236	n->rip_dst.sa_len = sizeof(n->rip_dst);
237	#endif
238	n->rip_metric = ntohl(n->rip_metric);
239	if (n->rip_dst.sa_family >= af_max \|\|
240	(afp = &afswitch[n->rip_dst.sa_family])->af_hash ==
241	(int (*)())0) {
242	syslog(LOG_INFO,
243	"route in unsupported address family (%d), from %s (af %d)\n",
244	n->rip_dst.sa_family,
245	(*afswitch[from->sa_family].af_format)(from),
246	from->sa_family);
247	continue;
248	}
249	if (((*afp->af_checkhost)(&n->rip_dst)) == 0) {
250	syslog(LOG_DEBUG,
251	"bad host in route from %s (af %d)\n",
252	(*afswitch[from->sa_family].af_format)(from),
253	from->sa_family);
254	continue;
255	}
256	if (n->rip_metric == 0 \|\|
257	(unsigned) n->rip_metric > HOPCNT_INFINITY) {
258	if (memcmp(from, &badfrom2,
259	sizeof(badfrom2)) != 0) {
260	syslog(LOG_ERR,
261	"bad metric (%d) from %s\n",
262	n->rip_metric,
263	(*afswitch[from->sa_family].af_format)(from));
264	badfrom2 = *from;
265	}
266	continue;
267	}
268	/*
269	* Adjust metric according to incoming interface.
270	*/
271	if ((unsigned) n->rip_metric < HOPCNT_INFINITY)
272	n->rip_metric += ifp->int_metric;
273	if ((unsigned) n->rip_metric > HOPCNT_INFINITY)
274	n->rip_metric = HOPCNT_INFINITY;
275	rt = rtlookup(&n->rip_dst);
276	if (rt == 0 \|\|
277	(rt->rt_state & (RTS_INTERNAL\|RTS_INTERFACE)) ==
278	(RTS_INTERNAL\|RTS_INTERFACE)) {
279	/*
280	* If we're hearing a logical network route
281	* back from a peer to which we sent it,
282	* ignore it.
283	*/
284	if (rt && rt->rt_state & RTS_SUBNET &&
285	(*afp->af_sendroute)(rt, from))
286	continue;
287	if ((unsigned)n->rip_metric < HOPCNT_INFINITY) {
288	/*
289	* Look for an equivalent route that
290	* includes this one before adding
291	* this route.
292	*/
293	rt = rtfind(&n->rip_dst);
294	if (rt && equal(from, &rt->rt_router))
295	continue;
296	rtadd(&n->rip_dst, from, n->rip_metric, 0);
297	changes++;
298	}
299	continue;
300	}
301
302	/*
303	* Update if from gateway and different,
304	* shorter, or equivalent but old route
305	* is getting stale.
306	*/
307	if (equal(from, &rt->rt_router)) {
308	if (n->rip_metric != rt->rt_metric) {
309	rtchange(rt, from, n->rip_metric);
310	changes++;
311	rt->rt_timer = 0;
312	if (rt->rt_metric >= HOPCNT_INFINITY)
313	rt->rt_timer =
314	GARBAGE_TIME - EXPIRE_TIME;
315	} else if (rt->rt_metric < HOPCNT_INFINITY)
316	rt->rt_timer = 0;
317	} else if ((unsigned) n->rip_metric < rt->rt_metric \|\|
318	(rt->rt_metric == n->rip_metric &&
319	rt->rt_timer > (EXPIRE_TIME/2) &&
320	(unsigned) n->rip_metric < HOPCNT_INFINITY)) {
321	rtchange(rt, from, n->rip_metric);
322	changes++;
323	rt->rt_timer = 0;
324	}
325	}
326	break;
327	}
328
329	/*
330	* If changes have occurred, and if we have not sent a broadcast
331	* recently, send a dynamic update. This update is sent only
332	* on interfaces other than the one on which we received notice
333	* of the change. If we are within MIN_WAITTIME of a full update,
334	* don't bother sending; if we just sent a dynamic update
335	* and set a timer (nextbcast), delay until that time.
336	* If we just sent a full update, delay the dynamic update.
337	* Set a timer for a randomized value to suppress additional
338	* dynamic updates until it expires; if we delayed sending
339	* the current changes, set needupdate.
340	*/
341	if (changes && supplier &&
342	now.tv_sec - lastfullupdate.tv_sec < SUPPLY_INTERVAL-MAX_WAITTIME) {
343	u_long delay;
344	extern long random();
345
346	if (now.tv_sec - lastbcast.tv_sec >= MIN_WAITTIME &&
347	timercmp(&nextbcast, &now, <)) {
348	if (traceactions)
349	fprintf(ftrace, "send dynamic update\n");
350	toall(supply, RTS_CHANGED, ifp);
351	lastbcast = now;
352	needupdate = 0;
353	nextbcast.tv_sec = 0;
354	} else {
355	needupdate++;
356	if (traceactions)
357	fprintf(ftrace, "delay dynamic update\n");
358	}
359	#define RANDOMDELAY() (MIN_WAITTIME * 1000000 + \
360	(u_long)random() % ((MAX_WAITTIME - MIN_WAITTIME) * 1000000))
361
362	if (nextbcast.tv_sec == 0) {
363	delay = RANDOMDELAY();
364	if (traceactions)
365	fprintf(ftrace,
366	"inhibit dynamic update for %d usec\n",
367	delay);
368	nextbcast.tv_sec = delay / 1000000;
369	nextbcast.tv_usec = delay % 1000000;
370	timevaladd(&nextbcast, &now);
371	/*
372	* If the next possibly dynamic update
373	* is within MIN_WAITTIME of the next full update,
374	* force the delay past the full update,
375	* or we might send a dynamic update just before
376	* the full update.
377	*/
378	if (nextbcast.tv_sec > lastfullupdate.tv_sec +
379	SUPPLY_INTERVAL - MIN_WAITTIME)
380	nextbcast.tv_sec = lastfullupdate.tv_sec +
381	SUPPLY_INTERVAL + 1;
382	}
383	}
384	}