[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 this notice is preserved and that due credit is given
 * to the University of California at 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'' without express or implied warranty.
 */

#ifndef lint
static char sccsid[] = "@(#)input.c	5.17 (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
	6	* provided that this notice is preserved and that due credit is given
	7	* to the University of California at Berkeley. The name of the University
	8	* may not be used to endorse or promote products derived from this
	9	* software without specific prior written permission. This software
	10	* is provided ``as is'' without express or implied warranty.
5ff67f98 DF	11	*/
5ff67f98 DF	12
2e74322d	13	#ifndef lint
09b9aef2	14	static char sccsid[] = "@(#)input.c 5.17 (Berkeley) %G%";
0eb85d71	15	#endif /* not lint */
2e74322d SL	16
	17	/*
	18	* Routing Table Management Daemon
	19	*/
7fe7fe74	20	#include "defs.h"
17fe297f	21	#include <sys/syslog.h>
2e74322d SL	22
	23	/*
	24	* Process a newly received packet.
	25	*/
	26	rip_input(from, size)
	27	struct sockaddr *from;
	28	int size;
	29	{
20df59f1 MK	30	register struct rt_entry *rt;
	31	register struct netinfo *n;
	32	register struct interface *ifp;
	33	struct interface *if_ifwithdstaddr();
2e74322d	34	int newsize;
20df59f1	35	register struct afswitch *afp;
09b9aef2	36	static struct sockaddr badfrom, badfrom2;
2e74322d SL	37
	38	ifp = 0;
	39	TRACE_INPUT(ifp, from, size);
17fe297f MK	40	if (from->sa_family >= af_max \|\|
	41	(afp = &afswitch[from->sa_family])->af_hash == (int (*)())0) {
	42	syslog(LOG_INFO,
	43	"\"from\" address in unsupported address family (%d), cmd %d\n",
	44	from->sa_family, msg->rip_cmd);
2e74322d	45	return;
17fe297f	46	}
2e74322d SL	47	switch (msg->rip_cmd) {
	48
	49	case RIPCMD_REQUEST:
	50	newsize = 0;
	51	size -= 4 * sizeof (char);
	52	n = msg->rip_nets;
	53	while (size > 0) {
	54	if (size < sizeof (struct netinfo))
	55	break;
	56	size -= sizeof (struct netinfo);
	57
55d340a4 SL	58	if (msg->rip_vers > 0) {
	59	n->rip_dst.sa_family =
	60	ntohs(n->rip_dst.sa_family);
	61	n->rip_metric = ntohl(n->rip_metric);
	62	}
2e74322d SL	63	/*
	64	* A single entry with sa_family == AF_UNSPEC and
	65	* metric ``infinity'' means ``all routes''.
17fe297f MK	66	* We respond to routers only if we are acting
	67	* as a supplier, or to anyone other than a router
	68	* (eg, query).
2e74322d SL	69	*/
2e74322d SL	70	if (n->rip_dst.sa_family == AF_UNSPEC &&
17deb420 MK	71	n->rip_metric == HOPCNT_INFINITY && size == 0) {
17deb420 MK	72	if (supplier \|\| (*afp->af_portmatch)(from) == 0)
4fad5a6e	73	supply(from, 0, 0);
2e74322d SL	74	return;
2e74322d SL	75	}
17deb420 MK	76	if (n->rip_dst.sa_family < af_max &&
	77	afswitch[n->rip_dst.sa_family].af_hash)
	78	rt = rtlookup(&n->rip_dst);
	79	else
	80	rt = 0;
2e74322d	81	n->rip_metric = rt == 0 ? HOPCNT_INFINITY :
cdf21aa5	82	min(rt->rt_metric + 1, HOPCNT_INFINITY);
55d340a4 SL	83	if (msg->rip_vers > 0) {
	84	n->rip_dst.sa_family =
	85	htons(n->rip_dst.sa_family);
	86	n->rip_metric = htonl(n->rip_metric);
	87	}
2e74322d SL	88	n++, newsize += sizeof (struct netinfo);
	89	}
	90	if (newsize > 0) {
	91	msg->rip_cmd = RIPCMD_RESPONSE;
	92	newsize += sizeof (int);
4f4bffaa	93	(*afp->af_output)(s, 0, from, newsize);
2e74322d SL	94	}
	95	return;
	96
	97	case RIPCMD_TRACEON:
	98	case RIPCMD_TRACEOFF:
b7e4f8be	99	/* verify message came from a privileged port */
2e74322d SL	100	if ((*afp->af_portcheck)(from) == 0)
2e74322d SL	101	return;
71786f50	102	if ((ifp = if_iflookup(from)) == 0 \|\| (ifp->int_flags &
98a1809a MK	103	(IFF_BROADCAST \| IFF_POINTOPOINT \| IFF_REMOTE)) == 0 \|\|
98a1809a MK	104	ifp->int_flags & IFF_PASSIVE) {
09069ad0	105	syslog(LOG_ERR, "trace command from unknown router, %s",
eb39c032	106	(*afswitch[from->sa_family].af_format)(from));
09069ad0 MK	107	return;
09069ad0 MK	108	}
2e74322d SL	109	packet[size] = '\0';
	110	if (msg->rip_cmd == RIPCMD_TRACEON)
	111	traceon(msg->rip_tracefile);
	112	else
	113	traceoff();
	114	return;
	115
	116	case RIPCMD_RESPONSE:
	117	/* verify message came from a router */
	118	if ((*afp->af_portmatch)(from) == 0)
	119	return;
	120	(*afp->af_canon)(from);
	121	/* are we talking to ourselves? */
	122	ifp = if_ifwithaddr(from);
	123	if (ifp) {
0f7c421b MK	124	if (ifp->int_flags & IFF_PASSIVE) {
	125	syslog(LOG_ERR,
	126	"bogus input (from passive interface, %s)",
	127	(*afswitch[from->sa_family].af_format)(from));
	128	return;
	129	}
2e74322d	130	rt = rtfind(from);
7892134c MK	131	if (rt == 0 \|\| ((rt->rt_state & RTS_INTERFACE) == 0) &&
7892134c MK	132	rt->rt_metric >= ifp->int_metric)
2e74322d SL	133	addrouteforif(ifp);
	134	else
	135	rt->rt_timer = 0;
	136	return;
	137	}
f1e15e15 MK	138	/*
	139	* Update timer for interface on which the packet arrived.
	140	* If from other end of a point-to-point link that isn't
	141	* in the routing tables, (re-)add the route.
	142	*/
09069ad0 MK	143	if ((rt = rtfind(from)) &&
09069ad0 MK	144	(rt->rt_state & (RTS_INTERFACE \| RTS_REMOTE)))
b7e4f8be	145	rt->rt_timer = 0;
7892134c MK	146	else if ((ifp = if_ifwithdstaddr(from)) &&
7892134c MK	147	(rt == 0 \|\| rt->rt_metric >= ifp->int_metric))
f1e15e15	148	addrouteforif(ifp);
71786f50 MK	149	/*
	150	* "Authenticate" router from which message originated.
	151	* We accept routing packets from routers directly connected
	152	* via broadcast or point-to-point networks,
	153	* and from those listed in /etc/gateways.
	154	*/
	155	if ((ifp = if_iflookup(from)) == 0 \|\| (ifp->int_flags &
98a1809a MK	156	(IFF_BROADCAST \| IFF_POINTOPOINT \| IFF_REMOTE)) == 0 \|\|
98a1809a MK	157	ifp->int_flags & IFF_PASSIVE) {
eb39c032 MK	158	if (bcmp((char )from, (char )&badfrom,
	159	sizeof(badfrom)) != 0) {
	160	syslog(LOG_ERR,
	161	"packet from unknown router, %s",
	162	(*afswitch[from->sa_family].af_format)(from));
	163	badfrom = *from;
	164	}
09069ad0 MK	165	return;
09069ad0 MK	166	}
2e74322d SL	167	size -= 4 * sizeof (char);
	168	n = msg->rip_nets;
	169	for (; size > 0; size -= sizeof (struct netinfo), n++) {
	170	if (size < sizeof (struct netinfo))
	171	break;
55d340a4 SL	172	if (msg->rip_vers > 0) {
	173	n->rip_dst.sa_family =
	174	ntohs(n->rip_dst.sa_family);
	175	n->rip_metric = ntohl(n->rip_metric);
	176	}
17fe297f MK	177	if (n->rip_dst.sa_family >= af_max \|\|
	178	(afp = &afswitch[n->rip_dst.sa_family])->af_hash ==
	179	(int (*)())0) {
	180	syslog(LOG_INFO,
	181	"route in unsupported address family (%d), from %s (af %d)\n",
	182	n->rip_dst.sa_family,
	183	(*afswitch[from->sa_family].af_format)(from),
	184	from->sa_family);
ed36994a	185	continue;
17fe297f MK	186	}
	187	if (((*afp->af_checkhost)(&n->rip_dst)) == 0) {
	188	syslog(LOG_DEBUG,
	189	"bad host in route from %s (af %d)\n",
	190	(*afswitch[from->sa_family].af_format)(from),
	191	from->sa_family);
2e74322d	192	continue;
17fe297f	193	}
09b9aef2 MK	194	if (n->rip_metric == 0 \|\|
	195	(unsigned) n->rip_metric > HOPCNT_INFINITY) {
	196	if (bcmp((char )from, (char )&badfrom2,
	197	sizeof(badfrom2)) != 0) {
	198	syslog(LOG_ERR,
	199	"bad metric (%d) from %s\n",
	200	n->rip_metric,
	201	(*afswitch[from->sa_family].af_format)(from));
	202	badfrom2 = *from;
	203	}
	204	continue;
	205	}
7892134c MK	206	/*
	207	* Adjust metric according to incoming interface.
	208	*/
cdf21aa5	209	if ((unsigned) n->rip_metric < HOPCNT_INFINITY)
7892134c	210	n->rip_metric += ifp->int_metric;
cdf21aa5 MK	211	if ((unsigned) n->rip_metric > HOPCNT_INFINITY)
cdf21aa5 MK	212	n->rip_metric = HOPCNT_INFINITY;
2e74322d	213	rt = rtlookup(&n->rip_dst);
97cb3618 MK	214	if (rt == 0 \|\|
	215	(rt->rt_state & (RTS_INTERNAL\|RTS_INTERFACE)) ==
	216	(RTS_INTERNAL\|RTS_INTERFACE)) {
7892134c MK	217	/*
	218	* If we're hearing a logical network route
	219	* back from a peer to which we sent it,
	220	* ignore it.
	221	*/
	222	if (rt && rt->rt_state & RTS_SUBNET &&
	223	(*afp->af_sendroute)(rt, from))
	224	continue;
0f7c421b MK	225	if ((unsigned)n->rip_metric < HOPCNT_INFINITY) {
	226	/*
	227	* Look for an equivalent route that
	228	* includes this one before adding
	229	* this route.
	230	*/
	231	rt = rtfind(&n->rip_dst);
	232	if (rt && equal(from, &rt->rt_router))
	233	continue;
20df59f1	234	rtadd(&n->rip_dst, from, n->rip_metric, 0);
0f7c421b	235	}
2e74322d SL	236	continue;
	237	}
	238
	239	/*
38ca17a8	240	* Update if from gateway and different,
0f7c421b MK	241	* shorter, or equivalent but old route
0f7c421b MK	242	* is getting stale.
2e74322d	243	*/
15e56604	244	if (equal(from, &rt->rt_router)) {
88709531	245	if (n->rip_metric != rt->rt_metric) {
15e56604	246	rtchange(rt, from, n->rip_metric);
0f7c421b	247	rt->rt_timer = 0;
7892134c	248	if (rt->rt_metric >= HOPCNT_INFINITY)
88709531 MK	249	rt->rt_timer =
	250	GARBAGE_TIME - EXPIRE_TIME;
	251	} else if (rt->rt_metric < HOPCNT_INFINITY)
585e6328	252	rt->rt_timer = 0;
cdf21aa5	253	} else if ((unsigned) n->rip_metric < rt->rt_metric \|\|
0f7c421b MK	254	(rt->rt_metric == n->rip_metric &&
0f7c421b MK	255	rt->rt_timer > (EXPIRE_TIME/2) &&
cdf21aa5	256	(unsigned) n->rip_metric < HOPCNT_INFINITY)) {
2e74322d SL	257	rtchange(rt, from, n->rip_metric);
	258	rt->rt_timer = 0;
	259	}
	260	}
	261	return;
	262	}
	263	}