[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	5.18 (Berkeley) %G%";
#endif /* not lint */

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

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

	ifp = 0;
	TRACE_INPUT(ifp, from, 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, msg->rip_cmd);
		return;
	}
	switch (msg->rip_cmd) {

	case RIPCMD_REQUEST:
		newsize = 0;
		size -= 4 * sizeof (char);
		n = msg->rip_nets;
		while (size > 0) {
			if (size < sizeof (struct netinfo))
				break;
			size -= sizeof (struct netinfo);

			if (msg->rip_vers > 0) {
				n->rip_dst.sa_family =
					ntohs(n->rip_dst.sa_family);
				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 && size == 0) {
			    	if (supplier || (*afp->af_portmatch)(from) == 0)
					supply(from, 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 (msg->rip_vers > 0) {
				n->rip_dst.sa_family =
					htons(n->rip_dst.sa_family);
				n->rip_metric = htonl(n->rip_metric);
			}
			n++, newsize += sizeof (struct netinfo);
		}
		if (newsize > 0) {
			msg->rip_cmd = RIPCMD_RESPONSE;
			newsize += sizeof (int);
			(*afp->af_output)(s, 0, from, newsize);
		}
		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;
		}
		packet[size] = '\0';
		if (msg->rip_cmd == RIPCMD_TRACEON)
			traceon(msg->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 = msg->rip_nets;
		for (; size > 0; size -= sizeof (struct netinfo), n++) {
			if (size < sizeof (struct netinfo))
				break;
			if (msg->rip_vers > 0) {
				n->rip_dst.sa_family =
					ntohs(n->rip_dst.sa_family);
				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);
				}
				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);
					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);
				rt->rt_timer = 0;
			}
		}
		return;
	}
}
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
b8c620d6	19	static char sccsid[] = "@(#)input.c 5.18 (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	*/
	31	rip_input(from, size)
	32	struct sockaddr *from;
	33	int size;
	34	{
20df59f1 MK	35	register struct rt_entry *rt;
	36	register struct netinfo *n;
	37	register struct interface *ifp;
	38	struct interface *if_ifwithdstaddr();
2e74322d	39	int newsize;
20df59f1	40	register struct afswitch *afp;
09b9aef2	41	static struct sockaddr badfrom, badfrom2;
2e74322d SL	42
	43	ifp = 0;
	44	TRACE_INPUT(ifp, from, size);
17fe297f MK	45	if (from->sa_family >= af_max \|\|
	46	(afp = &afswitch[from->sa_family])->af_hash == (int (*)())0) {
	47	syslog(LOG_INFO,
	48	"\"from\" address in unsupported address family (%d), cmd %d\n",
	49	from->sa_family, msg->rip_cmd);
2e74322d	50	return;
17fe297f	51	}
2e74322d SL	52	switch (msg->rip_cmd) {
	53
	54	case RIPCMD_REQUEST:
	55	newsize = 0;
	56	size -= 4 * sizeof (char);
	57	n = msg->rip_nets;
	58	while (size > 0) {
	59	if (size < sizeof (struct netinfo))
	60	break;
	61	size -= sizeof (struct netinfo);
	62
55d340a4 SL	63	if (msg->rip_vers > 0) {
	64	n->rip_dst.sa_family =
	65	ntohs(n->rip_dst.sa_family);
	66	n->rip_metric = ntohl(n->rip_metric);
	67	}
2e74322d SL	68	/*
	69	* A single entry with sa_family == AF_UNSPEC and
	70	* metric ``infinity'' means ``all routes''.
17fe297f MK	71	* We respond to routers only if we are acting
	72	* as a supplier, or to anyone other than a router
	73	* (eg, query).
2e74322d SL	74	*/
2e74322d SL	75	if (n->rip_dst.sa_family == AF_UNSPEC &&
17deb420 MK	76	n->rip_metric == HOPCNT_INFINITY && size == 0) {
17deb420 MK	77	if (supplier \|\| (*afp->af_portmatch)(from) == 0)
4fad5a6e	78	supply(from, 0, 0);
2e74322d SL	79	return;
2e74322d SL	80	}
17deb420 MK	81	if (n->rip_dst.sa_family < af_max &&
	82	afswitch[n->rip_dst.sa_family].af_hash)
	83	rt = rtlookup(&n->rip_dst);
	84	else
	85	rt = 0;
2e74322d	86	n->rip_metric = rt == 0 ? HOPCNT_INFINITY :
cdf21aa5	87	min(rt->rt_metric + 1, HOPCNT_INFINITY);
55d340a4 SL	88	if (msg->rip_vers > 0) {
	89	n->rip_dst.sa_family =
	90	htons(n->rip_dst.sa_family);
	91	n->rip_metric = htonl(n->rip_metric);
	92	}
2e74322d SL	93	n++, newsize += sizeof (struct netinfo);
	94	}
	95	if (newsize > 0) {
	96	msg->rip_cmd = RIPCMD_RESPONSE;
	97	newsize += sizeof (int);
4f4bffaa	98	(*afp->af_output)(s, 0, from, newsize);
2e74322d SL	99	}
	100	return;
	101
	102	case RIPCMD_TRACEON:
	103	case RIPCMD_TRACEOFF:
b7e4f8be	104	/* verify message came from a privileged port */
2e74322d SL	105	if ((*afp->af_portcheck)(from) == 0)
2e74322d SL	106	return;
71786f50	107	if ((ifp = if_iflookup(from)) == 0 \|\| (ifp->int_flags &
98a1809a MK	108	(IFF_BROADCAST \| IFF_POINTOPOINT \| IFF_REMOTE)) == 0 \|\|
98a1809a MK	109	ifp->int_flags & IFF_PASSIVE) {
09069ad0	110	syslog(LOG_ERR, "trace command from unknown router, %s",
eb39c032	111	(*afswitch[from->sa_family].af_format)(from));
09069ad0 MK	112	return;
09069ad0 MK	113	}
2e74322d SL	114	packet[size] = '\0';
	115	if (msg->rip_cmd == RIPCMD_TRACEON)
	116	traceon(msg->rip_tracefile);
	117	else
	118	traceoff();
	119	return;
	120
	121	case RIPCMD_RESPONSE:
	122	/* verify message came from a router */
	123	if ((*afp->af_portmatch)(from) == 0)
	124	return;
	125	(*afp->af_canon)(from);
	126	/* are we talking to ourselves? */
	127	ifp = if_ifwithaddr(from);
	128	if (ifp) {
0f7c421b MK	129	if (ifp->int_flags & IFF_PASSIVE) {
	130	syslog(LOG_ERR,
	131	"bogus input (from passive interface, %s)",
	132	(*afswitch[from->sa_family].af_format)(from));
	133	return;
	134	}
2e74322d	135	rt = rtfind(from);
7892134c MK	136	if (rt == 0 \|\| ((rt->rt_state & RTS_INTERFACE) == 0) &&
7892134c MK	137	rt->rt_metric >= ifp->int_metric)
2e74322d SL	138	addrouteforif(ifp);
	139	else
	140	rt->rt_timer = 0;
	141	return;
	142	}
f1e15e15 MK	143	/*
	144	* Update timer for interface on which the packet arrived.
	145	* If from other end of a point-to-point link that isn't
	146	* in the routing tables, (re-)add the route.
	147	*/
09069ad0 MK	148	if ((rt = rtfind(from)) &&
09069ad0 MK	149	(rt->rt_state & (RTS_INTERFACE \| RTS_REMOTE)))
b7e4f8be	150	rt->rt_timer = 0;
7892134c MK	151	else if ((ifp = if_ifwithdstaddr(from)) &&
7892134c MK	152	(rt == 0 \|\| rt->rt_metric >= ifp->int_metric))
f1e15e15	153	addrouteforif(ifp);
71786f50 MK	154	/*
	155	* "Authenticate" router from which message originated.
	156	* We accept routing packets from routers directly connected
	157	* via broadcast or point-to-point networks,
	158	* and from those listed in /etc/gateways.
	159	*/
	160	if ((ifp = if_iflookup(from)) == 0 \|\| (ifp->int_flags &
98a1809a MK	161	(IFF_BROADCAST \| IFF_POINTOPOINT \| IFF_REMOTE)) == 0 \|\|
98a1809a MK	162	ifp->int_flags & IFF_PASSIVE) {
eb39c032 MK	163	if (bcmp((char )from, (char )&badfrom,
	164	sizeof(badfrom)) != 0) {
	165	syslog(LOG_ERR,
	166	"packet from unknown router, %s",
	167	(*afswitch[from->sa_family].af_format)(from));
	168	badfrom = *from;
	169	}
09069ad0 MK	170	return;
09069ad0 MK	171	}
2e74322d SL	172	size -= 4 * sizeof (char);
	173	n = msg->rip_nets;
	174	for (; size > 0; size -= sizeof (struct netinfo), n++) {
	175	if (size < sizeof (struct netinfo))
	176	break;
55d340a4 SL	177	if (msg->rip_vers > 0) {
	178	n->rip_dst.sa_family =
	179	ntohs(n->rip_dst.sa_family);
	180	n->rip_metric = ntohl(n->rip_metric);
	181	}
17fe297f MK	182	if (n->rip_dst.sa_family >= af_max \|\|
	183	(afp = &afswitch[n->rip_dst.sa_family])->af_hash ==
	184	(int (*)())0) {
	185	syslog(LOG_INFO,
	186	"route in unsupported address family (%d), from %s (af %d)\n",
	187	n->rip_dst.sa_family,
	188	(*afswitch[from->sa_family].af_format)(from),
	189	from->sa_family);
ed36994a	190	continue;
17fe297f MK	191	}
	192	if (((*afp->af_checkhost)(&n->rip_dst)) == 0) {
	193	syslog(LOG_DEBUG,
	194	"bad host in route from %s (af %d)\n",
	195	(*afswitch[from->sa_family].af_format)(from),
	196	from->sa_family);
2e74322d	197	continue;
17fe297f	198	}
09b9aef2 MK	199	if (n->rip_metric == 0 \|\|
	200	(unsigned) n->rip_metric > HOPCNT_INFINITY) {
	201	if (bcmp((char )from, (char )&badfrom2,
	202	sizeof(badfrom2)) != 0) {
	203	syslog(LOG_ERR,
	204	"bad metric (%d) from %s\n",
	205	n->rip_metric,
	206	(*afswitch[from->sa_family].af_format)(from));
	207	badfrom2 = *from;
	208	}
	209	continue;
	210	}
7892134c MK	211	/*
	212	* Adjust metric according to incoming interface.
	213	*/
cdf21aa5	214	if ((unsigned) n->rip_metric < HOPCNT_INFINITY)
7892134c	215	n->rip_metric += ifp->int_metric;
cdf21aa5 MK	216	if ((unsigned) n->rip_metric > HOPCNT_INFINITY)
cdf21aa5 MK	217	n->rip_metric = HOPCNT_INFINITY;
2e74322d	218	rt = rtlookup(&n->rip_dst);
97cb3618 MK	219	if (rt == 0 \|\|
	220	(rt->rt_state & (RTS_INTERNAL\|RTS_INTERFACE)) ==
	221	(RTS_INTERNAL\|RTS_INTERFACE)) {
7892134c MK	222	/*
	223	* If we're hearing a logical network route
	224	* back from a peer to which we sent it,
	225	* ignore it.
	226	*/
	227	if (rt && rt->rt_state & RTS_SUBNET &&
	228	(*afp->af_sendroute)(rt, from))
	229	continue;
0f7c421b MK	230	if ((unsigned)n->rip_metric < HOPCNT_INFINITY) {
	231	/*
	232	* Look for an equivalent route that
	233	* includes this one before adding
	234	* this route.
	235	*/
	236	rt = rtfind(&n->rip_dst);
	237	if (rt && equal(from, &rt->rt_router))
	238	continue;
20df59f1	239	rtadd(&n->rip_dst, from, n->rip_metric, 0);
0f7c421b	240	}
2e74322d SL	241	continue;
	242	}
	243
	244	/*
38ca17a8	245	* Update if from gateway and different,
0f7c421b MK	246	* shorter, or equivalent but old route
0f7c421b MK	247	* is getting stale.
2e74322d	248	*/
15e56604	249	if (equal(from, &rt->rt_router)) {
88709531	250	if (n->rip_metric != rt->rt_metric) {
15e56604	251	rtchange(rt, from, n->rip_metric);
0f7c421b	252	rt->rt_timer = 0;
7892134c	253	if (rt->rt_metric >= HOPCNT_INFINITY)
88709531 MK	254	rt->rt_timer =
	255	GARBAGE_TIME - EXPIRE_TIME;
	256	} else if (rt->rt_metric < HOPCNT_INFINITY)
585e6328	257	rt->rt_timer = 0;
cdf21aa5	258	} else if ((unsigned) n->rip_metric < rt->rt_metric \|\|
0f7c421b MK	259	(rt->rt_metric == n->rip_metric &&
0f7c421b MK	260	rt->rt_timer > (EXPIRE_TIME/2) &&
cdf21aa5	261	(unsigned) n->rip_metric < HOPCNT_INFINITY)) {
2e74322d SL	262	rtchange(rt, from, n->rip_metric);
	263	rt->rt_timer = 0;
	264	}
	265	}
	266	return;
	267	}
	268	}