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

/*
 * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * "Portions Copyright (c) 1999 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 1.0 (the 'License').  You may not use this file
 * except in compliance with the License.  Please obtain a copy of the
 * License at http://www.apple.com/publicsource 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 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	*
	6	* "Portions Copyright (c) 1999 Apple Computer, Inc. All Rights
	7	* Reserved. This file contains Original Code and/or Modifications of
	8	* Original Code as defined in and that are subject to the Apple Public
	9	* Source License Version 1.0 (the 'License'). You may not use this file
	10	* except in compliance with the License. Please obtain a copy of the
	11	* License at http://www.apple.com/publicsource and read it before using
	12	* this file.
	13	*
	14	* The Original Code and all software distributed under the License are
	15	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	16	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	17	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	18	* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
	19	* License for the specific language governing rights and limitations
	20	* under the License."
	21	*
	22	* @APPLE_LICENSE_HEADER_END@
	23	*/
	24	/*
	25	* Copyright (c) 1983, 1988, 1993
	26	* The Regents of the University of California. All rights reserved.
	27	*
	28	* Redistribution and use in source and binary forms, with or without
	29	* modification, are permitted provided that the following conditions
	30	* are met:
	31	* 1. Redistributions of source code must retain the above copyright
	32	* notice, this list of conditions and the following disclaimer.
	33	* 2. Redistributions in binary form must reproduce the above copyright
	34	* notice, this list of conditions and the following disclaimer in the
	35	* documentation and/or other materials provided with the distribution.
	36	* 3. All advertising materials mentioning features or use of this software
	37	* must display the following acknowledgment:
	38	* This product includes software developed by the University of
	39	* California, Berkeley and its contributors.
	40	* 4. Neither the name of the University nor the names of its contributors
	41	* may be used to endorse or promote products derived from this software
	42	* without specific prior written permission.
	43	*
	44	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	45	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	46	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	47	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	48	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	49	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	50	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	51	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	52	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	53	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	54	* SUCH DAMAGE.
	55	*
	56	* @(#)defs.h 8.1 (Berkeley) 6/5/93
	57	*/
	58
	59
	60	/*
	61	* Routing Table Management Daemon
	62	*/
	63	#include "defs.h"
	64	#include <sys/syslog.h>
65
66	/*
67	* Process a newly received packet.
68	*/
69	rip_input(from, rip, size)
70	struct sockaddr *from;
71	register struct rip *rip;
72	int size;
73	{
74	register struct rt_entry *rt;
75	register struct netinfo *n;
76	register struct interface *ifp;
77	struct interface *if_ifwithdstaddr();
78	int count, changes = 0;
79	register struct afswitch *afp;
80	static struct sockaddr badfrom, badfrom2;
81
82	ifp = 0;
83	TRACE_INPUT(ifp, from, (char *)rip, size);
84	if (from->sa_family >= af_max \|\|
85	(afp = &afswitch[from->sa_family])->af_hash == (int (*)())0) {
86	syslog(LOG_INFO,
87	"\"from\" address in unsupported address family (%d), cmd %d\n",
88	from->sa_family, rip->rip_cmd);
89	return;
90	}
91	if (rip->rip_vers == 0) {
92	syslog(LOG_ERR,
93	"RIP version 0 packet received from %s! (cmd %d)",
94	(*afswitch[from->sa_family].af_format)(from), rip->rip_cmd);
95	return;
96	}
97	switch (rip->rip_cmd) {
98
99	case RIPCMD_REQUEST:
100	n = rip->rip_nets;
101	count = size - ((char )n - (char )rip);
102	if (count < sizeof (struct netinfo))
103	return;
104	for (; count > 0; n++) {
105	if (count < sizeof (struct netinfo))
106	break;
107	count -= sizeof (struct netinfo);
108
109	#if BSD < 198810
110	if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */
111	n->rip_dst.sa_family = ntohs(n->rip_dst.sa_family);
112	#else
113	#define osa(x) ((struct osockaddr *)(&(x)))
114	n->rip_dst.sa_family =
115	ntohs(osa(n->rip_dst)->sa_family);
116	n->rip_dst.sa_len = sizeof(n->rip_dst);
117	#endif
118	n->rip_metric = ntohl(n->rip_metric);
119	/*
120	* A single entry with sa_family == AF_UNSPEC and
121	* metric ``infinity'' means ``all routes''.
122	* We respond to routers only if we are acting
123	* as a supplier, or to anyone other than a router
124	* (eg, query).
125	*/
126	if (n->rip_dst.sa_family == AF_UNSPEC &&
127	n->rip_metric == HOPCNT_INFINITY && count == 0) {
128	if (supplier \|\| (*afp->af_portmatch)(from) == 0)
129	supply(from, 0, 0, 0);
130	return;
131	}
132	if (n->rip_dst.sa_family < af_max &&
133	afswitch[n->rip_dst.sa_family].af_hash)
134	rt = rtlookup(&n->rip_dst);
135	else
136	rt = 0;
137	#define min(a, b) (a < b ? a : b)
138	n->rip_metric = rt == 0 ? HOPCNT_INFINITY :
139	min(rt->rt_metric + 1, HOPCNT_INFINITY);
140	#if BSD < 198810
141	if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */
142	n->rip_dst.sa_family = htons(n->rip_dst.sa_family);
143	#else
144	osa(n->rip_dst)->sa_family =
145	htons(n->rip_dst.sa_family);
146	#endif
147	n->rip_metric = htonl(n->rip_metric);
148	}
149	rip->rip_cmd = RIPCMD_RESPONSE;
150	memmove(packet, rip, size);
151	(*afp->af_output)(s, 0, from, size);
152	return;
153
154	case RIPCMD_TRACEON:
155	case RIPCMD_TRACEOFF:
156	/* verify message came from a privileged port */
157	if ((*afp->af_portcheck)(from) == 0)
158	return;
159	if ((ifp = if_iflookup(from)) == 0 \|\| (ifp->int_flags &
160	(IFF_BROADCAST \| IFF_POINTOPOINT \| IFF_REMOTE)) == 0 \|\|
161	ifp->int_flags & IFF_PASSIVE) {
162	syslog(LOG_ERR, "trace command from unknown router, %s",
163	(*afswitch[from->sa_family].af_format)(from));
164	return;
165	}
166	((char *)rip)[size] = '\0';
167	if (rip->rip_cmd == RIPCMD_TRACEON)
168	traceon(rip->rip_tracefile);
169	else
170	traceoff();
171	return;
172
173	case RIPCMD_RESPONSE:
174	/* verify message came from a router */
175	if ((*afp->af_portmatch)(from) == 0)
176	return;
177	(*afp->af_canon)(from);
178	/* are we talking to ourselves? */
179	ifp = if_ifwithaddr(from);
180	if (ifp) {
181	if (ifp->int_flags & IFF_PASSIVE) {
182	syslog(LOG_ERR,
183	"bogus input (from passive interface, %s)",
184	(*afswitch[from->sa_family].af_format)(from));
185	return;
186	}
187	rt = rtfind(from);
188	if (rt == 0 \|\| ((rt->rt_state & RTS_INTERFACE) == 0) &&
189	rt->rt_metric >= ifp->int_metric)
190	addrouteforif(ifp);
191	else
192	rt->rt_timer = 0;
193	return;
194	}
195	/*
196	* Update timer for interface on which the packet arrived.
197	* If from other end of a point-to-point link that isn't
198	* in the routing tables, (re-)add the route.
199	*/
200	if ((rt = rtfind(from)) &&
201	(rt->rt_state & (RTS_INTERFACE \| RTS_REMOTE)))
202	rt->rt_timer = 0;
203	else if ((ifp = if_ifwithdstaddr(from)) &&
204	(rt == 0 \|\| rt->rt_metric >= ifp->int_metric))
205	addrouteforif(ifp);
206	/*
207	* "Authenticate" router from which message originated.
208	* We accept routing packets from routers directly connected
209	* via broadcast or point-to-point networks,
210	* and from those listed in /etc/gateways.
211	*/
212	if ((ifp = if_iflookup(from)) == 0 \|\| (ifp->int_flags &
213	(IFF_BROADCAST \| IFF_POINTOPOINT \| IFF_REMOTE)) == 0 \|\|
214	ifp->int_flags & IFF_PASSIVE) {
215	if (memcmp(from, &badfrom, sizeof(badfrom)) != 0) {
216	syslog(LOG_ERR,
217	"packet from unknown router, %s",
218	(*afswitch[from->sa_family].af_format)(from));
219	badfrom = *from;
220	}
221	return;
222	}
223	size -= 4 * sizeof (char);
224	n = rip->rip_nets;
225	for (; size > 0; size -= sizeof (struct netinfo), n++) {
226	if (size < sizeof (struct netinfo))
227	break;
228	#if BSD < 198810
229	if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */
230	n->rip_dst.sa_family =
231	ntohs(n->rip_dst.sa_family);
232	#else
233	n->rip_dst.sa_family =
234	ntohs(osa(n->rip_dst)->sa_family);
235	n->rip_dst.sa_len = sizeof(n->rip_dst);
236	#endif
237	n->rip_metric = ntohl(n->rip_metric);
238	if (n->rip_dst.sa_family >= af_max \|\|
239	(afp = &afswitch[n->rip_dst.sa_family])->af_hash ==
240	(int (*)())0) {
241	syslog(LOG_INFO,
242	"route in unsupported address family (%d), from %s (af %d)\n",
243	n->rip_dst.sa_family,
244	(*afswitch[from->sa_family].af_format)(from),
245	from->sa_family);
246	continue;
247	}
248	if (((*afp->af_checkhost)(&n->rip_dst)) == 0) {
249	syslog(LOG_DEBUG,
250	"bad host in route from %s (af %d)\n",
251	(*afswitch[from->sa_family].af_format)(from),
252	from->sa_family);
253	continue;
254	}
255	if (n->rip_metric == 0 \|\|
256	(unsigned) n->rip_metric > HOPCNT_INFINITY) {
257	if (memcmp(from, &badfrom2,
258	sizeof(badfrom2)) != 0) {
259	syslog(LOG_ERR,
260	"bad metric (%d) from %s\n",
261	n->rip_metric,
262	(*afswitch[from->sa_family].af_format)(from));
263	badfrom2 = *from;
264	}
265	continue;
266	}
267	/*
268	* Adjust metric according to incoming interface.
269	*/
270	if ((unsigned) n->rip_metric < HOPCNT_INFINITY)
271	n->rip_metric += ifp->int_metric;
272	if ((unsigned) n->rip_metric > HOPCNT_INFINITY)
273	n->rip_metric = HOPCNT_INFINITY;
274	rt = rtlookup(&n->rip_dst);
275	if (rt == 0 \|\|
276	(rt->rt_state & (RTS_INTERNAL\|RTS_INTERFACE)) ==
277	(RTS_INTERNAL\|RTS_INTERFACE)) {
278	/*
279	* If we're hearing a logical network route
280	* back from a peer to which we sent it,
281	* ignore it.
282	*/
283	if (rt && rt->rt_state & RTS_SUBNET &&
284	(*afp->af_sendroute)(rt, from))
285	continue;
286	if ((unsigned)n->rip_metric < HOPCNT_INFINITY) {
287	/*
288	* Look for an equivalent route that
289	* includes this one before adding
290	* this route.
291	*/
292	rt = rtfind(&n->rip_dst);
293	if (rt && equal(from, &rt->rt_router))
294	continue;
295	rtadd(&n->rip_dst, from, n->rip_metric, 0);
296	changes++;
297	}
298	continue;
299	}
300
301	/*
302	* Update if from gateway and different,
303	* shorter, or equivalent but old route
304	* is getting stale.
305	*/
306	if (equal(from, &rt->rt_router)) {
307	if (n->rip_metric != rt->rt_metric) {
308	rtchange(rt, from, n->rip_metric);
309	changes++;
310	rt->rt_timer = 0;
311	if (rt->rt_metric >= HOPCNT_INFINITY)
312	rt->rt_timer =
313	GARBAGE_TIME - EXPIRE_TIME;
314	} else if (rt->rt_metric < HOPCNT_INFINITY)
315	rt->rt_timer = 0;
316	} else if ((unsigned) n->rip_metric < rt->rt_metric \|\|
317	(rt->rt_metric == n->rip_metric &&
318	rt->rt_timer > (EXPIRE_TIME/2) &&
319	(unsigned) n->rip_metric < HOPCNT_INFINITY)) {
320	rtchange(rt, from, n->rip_metric);
321	changes++;
322	rt->rt_timer = 0;
323	}
324	}
325	break;
326	}
327
328	/*
329	* If changes have occurred, and if we have not sent a broadcast
330	* recently, send a dynamic update. This update is sent only
331	* on interfaces other than the one on which we received notice
332	* of the change. If we are within MIN_WAITTIME of a full update,
333	* don't bother sending; if we just sent a dynamic update
334	* and set a timer (nextbcast), delay until that time.
335	* If we just sent a full update, delay the dynamic update.
336	* Set a timer for a randomized value to suppress additional
337	* dynamic updates until it expires; if we delayed sending
338	* the current changes, set needupdate.
339	*/
340	if (changes && supplier &&
341	now.tv_sec - lastfullupdate.tv_sec < SUPPLY_INTERVAL-MAX_WAITTIME) {
342	u_long delay;
343	extern long random();
344
345	if (now.tv_sec - lastbcast.tv_sec >= MIN_WAITTIME &&
346	timercmp(&nextbcast, &now, <)) {
347	if (traceactions)
348	fprintf(ftrace, "send dynamic update\n");
349	toall(supply, RTS_CHANGED, ifp);
350	lastbcast = now;
351	needupdate = 0;
352	nextbcast.tv_sec = 0;
353	} else {
354	needupdate++;
355	if (traceactions)
356	fprintf(ftrace, "delay dynamic update\n");
357	}
358	#define RANDOMDELAY() (MIN_WAITTIME * 1000000 + \
359	(u_long)random() % ((MAX_WAITTIME - MIN_WAITTIME) * 1000000))
360
361	if (nextbcast.tv_sec == 0) {
362	delay = RANDOMDELAY();
363	if (traceactions)
364	fprintf(ftrace,
365	"inhibit dynamic update for %d usec\n",
366	delay);
367	nextbcast.tv_sec = delay / 1000000;
368	nextbcast.tv_usec = delay % 1000000;
369	timevaladd(&nextbcast, &now);
370	/*
371	* If the next possibly dynamic update
372	* is within MIN_WAITTIME of the next full update,
373	* force the delay past the full update,
374	* or we might send a dynamic update just before
375	* the full update.
376	*/
377	if (nextbcast.tv_sec > lastfullupdate.tv_sec +
378	SUPPLY_INTERVAL - MIN_WAITTIME)
379	nextbcast.tv_sec = lastfullupdate.tv_sec +
380	SUPPLY_INTERVAL + 1;
381	}
382	}
383	}