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

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

#ifndef lint
static char sccsid[] = "@(#)input.c	5.12 (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;

	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) {
			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) {
			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) {
			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 ((unsigned) n->rip_metric > HOPCNT_INFINITY)
				continue;
			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;
			}
			/*
			 * Adjust metric according to incoming interface.
			 */
			if ((unsigned)n->rip_metric < HOPCNT_INFINITY)
				n->rip_metric += ifp->int_metric;
			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;
				/*
				 * 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;
				if (n->rip_metric < HOPCNT_INFINITY)
				    rtadd(&n->rip_dst, from, n->rip_metric, 0);
				continue;
			}

			/*
			 * Update if from gateway and different,
			 * shorter, or getting stale and equivalent.
			 */
			if (equal(from, &rt->rt_router)) {
				if (n->rip_metric != rt->rt_metric) {
					rtchange(rt, from, n->rip_metric);
					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_timer > (EXPIRE_TIME/2) &&
			    rt->rt_metric == n->rip_metric &&
			    n->rip_metric < HOPCNT_INFINITY)) {
				rtchange(rt, from, n->rip_metric);
				rt->rt_timer = 0;
			}
		}
		return;
	}
}
Commit	Line	Data
5ff67f98 DF	1	/*
	2	* Copyright (c) 1983 Regents of the University of California.
	3	* All rights reserved. The Berkeley software License Agreement
	4	* specifies the terms and conditions for redistribution.
	5	*/
	6
2e74322d	7	#ifndef lint
7892134c	8	static char sccsid[] = "@(#)input.c 5.12 (Berkeley) %G%";
5ff67f98	9	#endif not lint
2e74322d SL	10
	11	/*
	12	* Routing Table Management Daemon
	13	*/
7fe7fe74	14	#include "defs.h"
17fe297f	15	#include <sys/syslog.h>
2e74322d SL	16
	17	/*
	18	* Process a newly received packet.
	19	*/
	20	rip_input(from, size)
	21	struct sockaddr *from;
	22	int size;
	23	{
20df59f1 MK	24	register struct rt_entry *rt;
	25	register struct netinfo *n;
	26	register struct interface *ifp;
	27	struct interface *if_ifwithdstaddr();
2e74322d	28	int newsize;
20df59f1	29	register struct afswitch *afp;
eb39c032	30	static struct sockaddr badfrom;
2e74322d SL	31
	32	ifp = 0;
	33	TRACE_INPUT(ifp, from, size);
17fe297f MK	34	if (from->sa_family >= af_max \|\|
	35	(afp = &afswitch[from->sa_family])->af_hash == (int (*)())0) {
	36	syslog(LOG_INFO,
	37	"\"from\" address in unsupported address family (%d), cmd %d\n",
	38	from->sa_family, msg->rip_cmd);
2e74322d	39	return;
17fe297f	40	}
2e74322d SL	41	switch (msg->rip_cmd) {
	42
	43	case RIPCMD_REQUEST:
	44	newsize = 0;
	45	size -= 4 * sizeof (char);
	46	n = msg->rip_nets;
	47	while (size > 0) {
	48	if (size < sizeof (struct netinfo))
	49	break;
	50	size -= sizeof (struct netinfo);
	51
55d340a4 SL	52	if (msg->rip_vers > 0) {
	53	n->rip_dst.sa_family =
	54	ntohs(n->rip_dst.sa_family);
	55	n->rip_metric = ntohl(n->rip_metric);
	56	}
2e74322d SL	57	/*
	58	* A single entry with sa_family == AF_UNSPEC and
	59	* metric ``infinity'' means ``all routes''.
17fe297f MK	60	* We respond to routers only if we are acting
	61	* as a supplier, or to anyone other than a router
	62	* (eg, query).
2e74322d SL	63	*/
2e74322d SL	64	if (n->rip_dst.sa_family == AF_UNSPEC &&
17deb420 MK	65	n->rip_metric == HOPCNT_INFINITY && size == 0) {
17deb420 MK	66	if (supplier \|\| (*afp->af_portmatch)(from) == 0)
4fad5a6e	67	supply(from, 0, 0);
2e74322d SL	68	return;
2e74322d SL	69	}
17deb420 MK	70	if (n->rip_dst.sa_family < af_max &&
	71	afswitch[n->rip_dst.sa_family].af_hash)
	72	rt = rtlookup(&n->rip_dst);
	73	else
	74	rt = 0;
2e74322d SL	75	n->rip_metric = rt == 0 ? HOPCNT_INFINITY :
2e74322d SL	76	min(rt->rt_metric+1, HOPCNT_INFINITY);
55d340a4 SL	77	if (msg->rip_vers > 0) {
	78	n->rip_dst.sa_family =
	79	htons(n->rip_dst.sa_family);
	80	n->rip_metric = htonl(n->rip_metric);
	81	}
2e74322d SL	82	n++, newsize += sizeof (struct netinfo);
	83	}
	84	if (newsize > 0) {
	85	msg->rip_cmd = RIPCMD_RESPONSE;
	86	newsize += sizeof (int);
4f4bffaa	87	(*afp->af_output)(s, 0, from, newsize);
2e74322d SL	88	}
	89	return;
	90
	91	case RIPCMD_TRACEON:
	92	case RIPCMD_TRACEOFF:
b7e4f8be	93	/* verify message came from a privileged port */
2e74322d SL	94	if ((*afp->af_portcheck)(from) == 0)
2e74322d SL	95	return;
71786f50 MK	96	if ((ifp = if_iflookup(from)) == 0 \|\| (ifp->int_flags &
71786f50 MK	97	(IFF_BROADCAST \| IFF_POINTOPOINT \| IFF_REMOTE)) == 0) {
09069ad0	98	syslog(LOG_ERR, "trace command from unknown router, %s",
eb39c032	99	(*afswitch[from->sa_family].af_format)(from));
09069ad0 MK	100	return;
09069ad0 MK	101	}
2e74322d SL	102	packet[size] = '\0';
	103	if (msg->rip_cmd == RIPCMD_TRACEON)
	104	traceon(msg->rip_tracefile);
	105	else
	106	traceoff();
	107	return;
	108
	109	case RIPCMD_RESPONSE:
	110	/* verify message came from a router */
	111	if ((*afp->af_portmatch)(from) == 0)
	112	return;
	113	(*afp->af_canon)(from);
	114	/* are we talking to ourselves? */
	115	ifp = if_ifwithaddr(from);
	116	if (ifp) {
	117	rt = rtfind(from);
7892134c MK	118	if (rt == 0 \|\| ((rt->rt_state & RTS_INTERFACE) == 0) &&
7892134c MK	119	rt->rt_metric >= ifp->int_metric)
2e74322d SL	120	addrouteforif(ifp);
	121	else
	122	rt->rt_timer = 0;
	123	return;
	124	}
f1e15e15 MK	125	/*
	126	* Update timer for interface on which the packet arrived.
	127	* If from other end of a point-to-point link that isn't
	128	* in the routing tables, (re-)add the route.
	129	*/
09069ad0 MK	130	if ((rt = rtfind(from)) &&
09069ad0 MK	131	(rt->rt_state & (RTS_INTERFACE \| RTS_REMOTE)))
b7e4f8be	132	rt->rt_timer = 0;
7892134c MK	133	else if ((ifp = if_ifwithdstaddr(from)) &&
7892134c MK	134	(rt == 0 \|\| rt->rt_metric >= ifp->int_metric))
f1e15e15	135	addrouteforif(ifp);
71786f50 MK	136	/*
	137	* "Authenticate" router from which message originated.
	138	* We accept routing packets from routers directly connected
	139	* via broadcast or point-to-point networks,
	140	* and from those listed in /etc/gateways.
	141	*/
	142	if ((ifp = if_iflookup(from)) == 0 \|\| (ifp->int_flags &
	143	(IFF_BROADCAST \| IFF_POINTOPOINT \| IFF_REMOTE)) == 0) {
eb39c032 MK	144	if (bcmp((char )from, (char )&badfrom,
	145	sizeof(badfrom)) != 0) {
	146	syslog(LOG_ERR,
	147	"packet from unknown router, %s",
	148	(*afswitch[from->sa_family].af_format)(from));
	149	badfrom = *from;
	150	}
09069ad0 MK	151	return;
09069ad0 MK	152	}
2e74322d SL	153	size -= 4 * sizeof (char);
	154	n = msg->rip_nets;
	155	for (; size > 0; size -= sizeof (struct netinfo), n++) {
	156	if (size < sizeof (struct netinfo))
	157	break;
55d340a4 SL	158	if (msg->rip_vers > 0) {
	159	n->rip_dst.sa_family =
	160	ntohs(n->rip_dst.sa_family);
	161	n->rip_metric = ntohl(n->rip_metric);
	162	}
20df59f1	163	if ((unsigned) n->rip_metric > HOPCNT_INFINITY)
d5568f13	164	continue;
17fe297f MK	165	if (n->rip_dst.sa_family >= af_max \|\|
	166	(afp = &afswitch[n->rip_dst.sa_family])->af_hash ==
	167	(int (*)())0) {
	168	syslog(LOG_INFO,
	169	"route in unsupported address family (%d), from %s (af %d)\n",
	170	n->rip_dst.sa_family,
	171	(*afswitch[from->sa_family].af_format)(from),
	172	from->sa_family);
ed36994a	173	continue;
17fe297f MK	174	}
	175	if (((*afp->af_checkhost)(&n->rip_dst)) == 0) {
	176	syslog(LOG_DEBUG,
	177	"bad host in route from %s (af %d)\n",
	178	(*afswitch[from->sa_family].af_format)(from),
	179	from->sa_family);
2e74322d	180	continue;
17fe297f	181	}
7892134c MK	182	/*
	183	* Adjust metric according to incoming interface.
	184	*/
	185	if ((unsigned)n->rip_metric < HOPCNT_INFINITY)
	186	n->rip_metric += ifp->int_metric;
2e74322d	187	rt = rtlookup(&n->rip_dst);
97cb3618 MK	188	if (rt == 0 \|\|
	189	(rt->rt_state & (RTS_INTERNAL\|RTS_INTERFACE)) ==
	190	(RTS_INTERNAL\|RTS_INTERFACE)) {
7892134c MK	191	/*
	192	* If we're hearing a logical network route
	193	* back from a peer to which we sent it,
	194	* ignore it.
	195	*/
	196	if (rt && rt->rt_state & RTS_SUBNET &&
	197	(*afp->af_sendroute)(rt, from))
	198	continue;
	199	/*
	200	* Look for an equivalent route that includes
	201	* this one before adding this route.
	202	*/
09069ad0	203	rt = rtfind(&n->rip_dst);
7892134c	204	if (rt && equal(from, &rt->rt_router))
09069ad0	205	continue;
20df59f1 MK	206	if (n->rip_metric < HOPCNT_INFINITY)
20df59f1 MK	207	rtadd(&n->rip_dst, from, n->rip_metric, 0);
2e74322d SL	208	continue;
	209	}
	210
	211	/*
38ca17a8 MK	212	* Update if from gateway and different,
38ca17a8 MK	213	* shorter, or getting stale and equivalent.
2e74322d	214	*/
15e56604	215	if (equal(from, &rt->rt_router)) {
88709531	216	if (n->rip_metric != rt->rt_metric) {
15e56604	217	rtchange(rt, from, n->rip_metric);
7892134c	218	if (rt->rt_metric >= HOPCNT_INFINITY)
88709531 MK	219	rt->rt_timer =
	220	GARBAGE_TIME - EXPIRE_TIME;
	221	} else if (rt->rt_metric < HOPCNT_INFINITY)
585e6328	222	rt->rt_timer = 0;
15e56604	223	} else if ((unsigned) (n->rip_metric) < rt->rt_metric \|\|
2e74322d	224	(rt->rt_timer > (EXPIRE_TIME/2) &&
7892134c MK	225	rt->rt_metric == n->rip_metric &&
7892134c MK	226	n->rip_metric < HOPCNT_INFINITY)) {
2e74322d SL	227	rtchange(rt, from, n->rip_metric);
	228	rt->rt_timer = 0;
	229	}
	230	}
	231	return;
	232	}
	233	}