2 * Copyright (c) 1983, 1988, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 #elif defined(__FreeBSD__)
39 __RCSID("$Revision: 2.26 $");
40 #ident "$Revision: 2.26 $"
43 static void input(struct sockaddr_in *, struct interface *, struct interface *,
45 static void input_route(naddr, naddr, struct rt_spare *, struct netinfo *);
46 static int ck_passwd(struct interface *, struct rip *, void *,
47 naddr, struct msg_limit *);
54 struct interface *sifp)
56 struct sockaddr_in from;
57 struct interface *aifp;
61 static struct msg_limit bad_name;
63 char ifname[IFNAMSIZ];
74 fromlen = sizeof(from);
75 cc = recvfrom(sock, &inbuf, sizeof(inbuf), 0,
76 (struct sockaddr*)&from, &fromlen);
78 if (cc < 0 && errno != EWOULDBLOCK)
79 LOGERR("recvfrom(rip)");
82 if (fromlen != sizeof(struct sockaddr_in))
83 logbad(1,"impossible recvfrom(rip) fromlen=%d",
86 /* aifp is the "authenticated" interface via which the packet
87 * arrived. In fact, it is only the interface on which
88 * the packet should have arrived based on is source
90 * sifp is interface associated with the socket through which
91 * the packet was received.
94 if ((cc -= sizeof(inbuf.ifname)) < 0)
95 logbad(0,"missing USE_PASSIFNAME; only %d bytes",
96 cc+sizeof(inbuf.ifname));
98 /* check the remote interfaces first */
99 LIST_FOREACH(aifp, &remote_if, remote_list) {
100 if (aifp->int_addr == from.sin_addr.s_addr)
104 aifp = ifwithname(inbuf.ifname, 0);
106 msglim(&bad_name, from.sin_addr.s_addr,
107 "impossible interface name %.*s",
108 IFNAMSIZ, inbuf.ifname);
109 } else if (((aifp->int_if_flags & IFF_POINTOPOINT)
110 && aifp->int_dstaddr!=from.sin_addr.s_addr)
111 || (!(aifp->int_if_flags & IFF_POINTOPOINT)
112 && !on_net(from.sin_addr.s_addr,
115 /* If it came via the wrong interface, do not
122 aifp = iflookup(from.sin_addr.s_addr);
127 input(&from, sifp, aifp, &inbuf.pbuf.rip, cc);
132 /* Process a RIP packet
135 input(struct sockaddr_in *from, /* received from this IP address */
136 struct interface *sifp, /* interface of incoming socket */
137 struct interface *aifp, /* "authenticated" interface */
141 # define FROM_NADDR from->sin_addr.s_addr
142 static struct msg_limit use_auth, bad_len, bad_mask;
143 static struct msg_limit unk_router, bad_router, bad_nhop;
147 struct netinfo *n, *lim;
148 struct interface *ifp1;
149 naddr gate, mask, v1_mask, dst, ddst_h = 0;
151 struct tgate *tg = 0;
152 struct tgate_net *tn;
155 /* Notice when we hear from a remote gateway
158 && (aifp->int_state & IS_REMOTE))
159 aifp->int_act_time = now.tv_sec;
161 trace_rip("Recv", "from", from, sifp, rip, cc);
163 if (rip->rip_vers == 0) {
164 msglim(&bad_router, FROM_NADDR,
165 "RIP version 0, cmd %d, packet received from %s",
166 rip->rip_cmd, naddr_ntoa(FROM_NADDR));
168 } else if (rip->rip_vers > RIPv2) {
169 rip->rip_vers = RIPv2;
171 if (cc > (int)OVER_MAXPACKETSIZE) {
172 msglim(&bad_router, FROM_NADDR,
173 "packet at least %d bytes too long received from %s",
174 cc-MAXPACKETSIZE, naddr_ntoa(FROM_NADDR));
179 lim = (struct netinfo *)((char*)rip + cc);
181 /* Notice authentication.
182 * As required by section 4.2 in RFC 1723, discard authenticated
183 * RIPv2 messages, but only if configured for that silliness.
185 * RIPv2 authentication is lame. Why authenticate queries?
186 * Why should a RIPv2 implementation with authentication disabled
187 * not be able to listen to RIPv2 packets with authentication, while
188 * RIPv1 systems will listen? Crazy!
191 && rip->rip_vers == RIPv2
192 && n < lim && n->n_family == RIP_AF_AUTH) {
193 msglim(&use_auth, FROM_NADDR,
194 "RIPv2 message with authentication from %s discarded",
195 naddr_ntoa(FROM_NADDR));
199 switch (rip->rip_cmd) {
201 /* For mere requests, be a little sloppy about the source
206 /* Are we talking to ourself or a remote gateway?
208 ifp1 = ifwithaddr(FROM_NADDR, 0, 1);
210 if (ifp1->int_state & IS_REMOTE) {
213 if (check_remote(aifp)) {
214 aifp->int_act_time = now.tv_sec;
215 (void)if_ok(aifp, "remote ");
217 } else if (from->sin_port == htons(RIP_PORT)) {
218 trace_pkt(" discard our own RIP request");
223 /* did the request come from a router?
225 if (from->sin_port == htons(RIP_PORT)) {
226 /* yes, ignore the request if RIP is off so that
227 * the router does not depend on us.
231 && IS_RIP_OUT_OFF(aifp->int_state))) {
232 trace_pkt(" discard request while RIP off");
237 /* According to RFC 1723, we should ignore unauthenticated
238 * queries. That is too silly to bother with. Sheesh!
239 * Are forwarding tables supposed to be secret, when
240 * a bad guy can infer them with test traffic? When RIP
241 * is still the most common router-discovery protocol
242 * and so hosts need to send queries that will be answered?
243 * What about `rtquery`?
244 * Maybe on firewalls you'd care, but not enough to
245 * give up the diagnostic facilities of remote probing.
249 msglim(&bad_len, FROM_NADDR, "empty request from %s",
250 naddr_ntoa(FROM_NADDR));
253 if (cc%sizeof(*n) != sizeof(struct rip)%sizeof(*n)) {
254 msglim(&bad_len, FROM_NADDR,
255 "request of bad length (%d) from %s",
256 cc, naddr_ntoa(FROM_NADDR));
259 if (rip->rip_vers == RIPv2
260 && (aifp == 0 || (aifp->int_state & IS_NO_RIPV1_OUT))) {
261 v12buf.buf->rip_vers = RIPv2;
262 /* If we have a secret but it is a cleartext secret,
263 * do not disclose our secret unless the other guy
266 ap = find_auth(aifp);
267 if (ap != 0 && ap->type == RIP_AUTH_PW
268 && n->n_family == RIP_AF_AUTH
269 && !ck_passwd(aifp,rip,lim,FROM_NADDR,&use_auth))
272 v12buf.buf->rip_vers = RIPv1;
275 clr_ws_buf(&v12buf, ap);
278 n->n_metric = ntohl(n->n_metric);
280 /* A single entry with family RIP_AF_UNSPEC and
281 * metric HOPCNT_INFINITY means "all routes".
282 * We respond to routers only if we are acting
283 * as a supplier, or to anyone other than a router
286 if (n->n_family == RIP_AF_UNSPEC
287 && n->n_metric == HOPCNT_INFINITY) {
288 /* Answer a query from a utility program
292 trace_pkt("ignore remote query");
295 if (from->sin_port != htons(RIP_PORT)) {
297 * insecure: query from non-router node
298 * > 1: allow from distant node
299 * > 0: allow from neighbor node
302 if ((aifp != NULL && insecure > 0) ||
303 (aifp == NULL && insecure > 1))
304 supply(from, aifp, OUT_QUERY, 0,
305 rip->rip_vers, ap != 0);
307 trace_pkt("Warning: "
308 "possible attack detected");
312 /* A router trying to prime its tables.
313 * Filter the answer in the about same way
314 * broadcasts are filtered.
316 * Only answer a router if we are a supplier
317 * to keep an unwary host that is just starting
318 * from picking us as a router.
321 trace_pkt("ignore distant router");
325 || IS_RIP_OFF(aifp->int_state)) {
326 trace_pkt("ignore; not supplying");
330 /* Do not answer a RIPv1 router if
331 * we are sending RIPv2. But do offer
332 * poor man's router discovery.
334 if ((aifp->int_state & IS_NO_RIPV1_OUT)
335 && rip->rip_vers == RIPv1) {
336 if (!(aifp->int_state & IS_PM_RDISC)) {
337 trace_pkt("ignore; sending RIPv2");
341 v12buf.n->n_family = RIP_AF_INET;
342 v12buf.n->n_dst = RIP_DEFAULT;
343 i = aifp->int_d_metric;
344 if (0 != (rt = rtget(RIP_DEFAULT, 0))) {
347 +aifp->int_adj_outmetric
352 v12buf.n->n_metric = htonl(i);
357 /* Respond with RIPv1 instead of RIPv2 if
358 * that is what we are broadcasting on the
359 * interface to keep the remote router from
360 * getting the wrong initial idea of the
363 supply(from, aifp, OUT_UNICAST, 0,
364 (aifp->int_state & IS_NO_RIPV1_OUT)
370 /* Ignore authentication */
371 if (n->n_family == RIP_AF_AUTH)
374 if (n->n_family != RIP_AF_INET) {
375 msglim(&bad_router, FROM_NADDR,
376 "request from %s for unsupported"
378 naddr_ntoa(FROM_NADDR),
380 naddr_ntoa(n->n_dst));
384 /* We are being asked about a specific destination.
387 if (!check_dst(dst)) {
388 msglim(&bad_router, FROM_NADDR,
389 "bad queried destination %s from %s",
391 naddr_ntoa(FROM_NADDR));
395 /* decide what mask was intended */
396 if (rip->rip_vers == RIPv1
397 || 0 == (mask = ntohl(n->n_mask))
398 || 0 != (ntohl(dst) & ~mask))
399 mask = ripv1_mask_host(dst, aifp);
401 /* try to find the answer */
402 rt = rtget(dst, mask);
403 if (!rt && dst != RIP_DEFAULT)
404 rt = rtfind(n->n_dst);
406 if (v12buf.buf->rip_vers != RIPv1)
407 v12buf.n->n_mask = mask;
409 /* we do not have the answer */
410 v12buf.n->n_metric = HOPCNT_INFINITY;
412 /* we have the answer, so compute the
413 * right metric and next hop.
415 v12buf.n->n_family = RIP_AF_INET;
416 v12buf.n->n_dst = dst;
421 j += (aifp->int_metric
422 + aifp->int_adj_outmetric);
423 if (j < HOPCNT_INFINITY)
424 v12buf.n->n_metric = j;
426 v12buf.n->n_metric = HOPCNT_INFINITY;
427 if (v12buf.buf->rip_vers != RIPv1) {
428 v12buf.n->n_tag = rt->rt_tag;
429 v12buf.n->n_mask = mask;
431 && on_net(rt->rt_gate,
434 && rt->rt_gate != aifp->int_addr)
435 v12buf.n->n_nhop = rt->rt_gate;
438 v12buf.n->n_metric = htonl(v12buf.n->n_metric);
440 /* Stop paying attention if we fill the output buffer.
442 if (++v12buf.n >= v12buf.lim)
446 /* Send the answer about specific routes.
448 if (ap != 0 && ap->type == RIP_AUTH_MD5)
449 end_md5_auth(&v12buf, ap);
451 if (from->sin_port != htons(RIP_PORT)) {
453 (void)output(OUT_QUERY, from, aifp,
455 ((char *)v12buf.n - (char*)v12buf.buf));
456 } else if (supplier) {
457 (void)output(OUT_UNICAST, from, aifp,
459 ((char *)v12buf.n - (char*)v12buf.buf));
461 /* Only answer a router if we are a supplier
462 * to keep an unwary host that is just starting
463 * from picking us an a router.
470 case RIPCMD_TRACEOFF:
471 /* Notice that trace messages are turned off for all possible
472 * abuse if _PATH_TRACE is undefined in pathnames.h.
473 * Notice also that because of the way the trace file is
474 * handled in trace.c, no abuse is plausible even if
475 * _PATH_TRACE_ is defined.
477 * First verify message came from a privileged port. */
478 if (ntohs(from->sin_port) > IPPORT_RESERVED) {
479 msglog("trace command from untrusted port on %s",
480 naddr_ntoa(FROM_NADDR));
484 msglog("trace command from unknown router %s",
485 naddr_ntoa(FROM_NADDR));
488 if (rip->rip_cmd == RIPCMD_TRACEON) {
489 rip->rip_tracefile[cc-4] = '\0';
490 set_tracefile((char*)rip->rip_tracefile,
491 "trace command: %s\n", 0);
493 trace_off("tracing turned off by %s",
494 naddr_ntoa(FROM_NADDR));
498 case RIPCMD_RESPONSE:
499 if (cc%sizeof(*n) != sizeof(struct rip)%sizeof(*n)) {
500 msglim(&bad_len, FROM_NADDR,
501 "response of bad length (%d) from %s",
502 cc, naddr_ntoa(FROM_NADDR));
505 /* verify message came from a router */
506 if (from->sin_port != ntohs(RIP_PORT)) {
507 msglim(&bad_router, FROM_NADDR,
508 " discard RIP response from unknown port"
510 ntohs(from->sin_port), naddr_ntoa(FROM_NADDR));
515 trace_pkt(" discard response while RIP off");
519 /* Are we talking to ourself or a remote gateway?
521 ifp1 = ifwithaddr(FROM_NADDR, 0, 1);
523 if (ifp1->int_state & IS_REMOTE) {
526 if (check_remote(aifp)) {
527 aifp->int_act_time = now.tv_sec;
528 (void)if_ok(aifp, "remote ");
531 trace_pkt(" discard our own RIP response");
536 /* Accept routing packets from routers directly connected
537 * via broadcast or point-to-point networks, and from
538 * those listed in /etc/gateways.
541 msglim(&unk_router, FROM_NADDR,
542 " discard response from %s"
543 " via unexpected interface",
544 naddr_ntoa(FROM_NADDR));
547 if (IS_RIP_IN_OFF(aifp->int_state)) {
548 trace_pkt(" discard RIPv%d response"
549 " via disabled interface %s",
550 rip->rip_vers, aifp->int_name);
555 msglim(&bad_len, FROM_NADDR, "empty response from %s",
556 naddr_ntoa(FROM_NADDR));
560 if (((aifp->int_state & IS_NO_RIPV1_IN)
561 && rip->rip_vers == RIPv1)
562 || ((aifp->int_state & IS_NO_RIPV2_IN)
563 && rip->rip_vers != RIPv1)) {
564 trace_pkt(" discard RIPv%d response",
569 /* Ignore routes via dead interface.
571 if (aifp->int_state & IS_BROKE) {
572 trace_pkt("discard response via broken interface %s",
577 /* If the interface cares, ignore bad routers.
578 * Trace but do not log this problem, because where it
579 * happens, it happens frequently.
581 if (aifp->int_state & IS_DISTRUST) {
583 while (tg->tgate_addr != FROM_NADDR) {
586 trace_pkt(" discard RIP response"
587 " from untrusted router %s",
588 naddr_ntoa(FROM_NADDR));
594 /* Authenticate the packet if we have a secret.
595 * If we do not have any secrets, ignore the error in
596 * RFC 1723 and accept it regardless.
598 if (aifp->int_auth[0].type != RIP_AUTH_NONE
599 && rip->rip_vers != RIPv1
600 && !ck_passwd(aifp,rip,lim,FROM_NADDR,&use_auth))
604 if (n->n_family == RIP_AF_AUTH)
607 n->n_metric = ntohl(n->n_metric);
609 if (n->n_family != RIP_AF_INET
610 && (n->n_family != RIP_AF_UNSPEC
611 || dst != RIP_DEFAULT)) {
612 msglim(&bad_router, FROM_NADDR,
613 "route from %s to unsupported"
614 " address family=%d destination=%s",
615 naddr_ntoa(FROM_NADDR),
620 if (!check_dst(dst)) {
621 msglim(&bad_router, FROM_NADDR,
622 "bad destination %s from %s",
624 naddr_ntoa(FROM_NADDR));
628 || n->n_metric > HOPCNT_INFINITY) {
629 msglim(&bad_router, FROM_NADDR,
630 "bad metric %d from %s"
631 " for destination %s",
633 naddr_ntoa(FROM_NADDR),
638 /* Notice the next-hop.
641 if (n->n_nhop != 0) {
642 if (rip->rip_vers == RIPv1) {
645 /* Use it only if it is valid. */
646 if (on_net(n->n_nhop,
647 aifp->int_net, aifp->int_mask)
648 && check_dst(n->n_nhop)) {
651 msglim(&bad_nhop, FROM_NADDR,
653 " has bad next hop %s",
654 naddr_ntoa(FROM_NADDR),
656 naddr_ntoa(n->n_nhop));
662 if (rip->rip_vers == RIPv1
663 || 0 == (mask = ntohl(n->n_mask))) {
664 mask = ripv1_mask_host(dst,aifp);
665 } else if ((ntohl(dst) & ~mask) != 0) {
666 msglim(&bad_mask, FROM_NADDR,
667 "router %s sent bad netmask"
669 naddr_ntoa(FROM_NADDR),
674 if (rip->rip_vers == RIPv1)
677 /* Adjust metric according to incoming interface..
679 n->n_metric += (aifp->int_metric
680 + aifp->int_adj_inmetric);
681 if (n->n_metric > HOPCNT_INFINITY)
682 n->n_metric = HOPCNT_INFINITY;
684 /* Should we trust this route from this router? */
685 if (tg && (tn = tg->tgate_nets)->mask != 0) {
686 for (i = 0; i < MAX_TGATE_NETS; i++, tn++) {
687 if (on_net(dst, tn->net, tn->mask)
691 if (i >= MAX_TGATE_NETS || tn->mask == 0) {
692 trace_pkt(" ignored unauthorized %s",
693 addrname(dst,mask,0));
698 /* Recognize and ignore a default route we faked
699 * which is being sent back to us by a machine with
700 * broken split-horizon.
701 * Be a little more paranoid than that, and reject
702 * default routes with the same metric we advertised.
704 if (aifp->int_d_metric != 0
705 && dst == RIP_DEFAULT
706 && (int)n->n_metric >= aifp->int_d_metric)
709 /* We can receive aggregated RIPv2 routes that must
710 * be broken down before they are transmitted by
711 * RIPv1 via an interface on a subnet.
712 * We might also receive the same routes aggregated
713 * via other RIPv2 interfaces.
714 * This could cause duplicate routes to be sent on
715 * the RIPv1 interfaces. "Longest matching variable
716 * length netmasks" lets RIPv2 listeners understand,
717 * but breaking down the aggregated routes for RIPv1
718 * listeners can produce duplicate routes.
720 * Breaking down aggregated routes here bloats
721 * the daemon table, but does not hurt the kernel
722 * table, since routes are always aggregated for
725 * Notice that this does not break down network
726 * routes corresponding to subnets. This is part
727 * of the defense against RS_NET_SYN.
730 && (((rt = rtget(dst,mask)) == 0
731 || !(rt->rt_state & RS_NET_SYN)))
732 && (v1_mask = ripv1_mask_net(dst,0)) > mask) {
733 ddst_h = v1_mask & -v1_mask;
734 i = (v1_mask & ~mask)/ddst_h;
736 /* Punt if we would have to generate
737 * an unreasonable number of routes.
740 trace_misc("accept %s-->%s as 1"
741 " instead of %d routes",
742 addrname(dst,mask,0),
743 naddr_ntoa(FROM_NADDR),
754 new.rts_router = FROM_NADDR;
755 new.rts_metric = n->n_metric;
756 new.rts_tag = n->n_tag;
757 new.rts_time = now.tv_sec;
762 input_route(dst, mask, &new, n);
765 dst = htonl(ntohl(dst) + ddst_h);
774 /* Process a single input route.
777 input_route(naddr dst, /* network order */
779 struct rt_spare *new,
784 struct rt_spare *rts, *rts0;
785 struct interface *ifp1;
788 /* See if the other guy is telling us to send our packets to him.
789 * Sometimes network routes arrive over a point-to-point link for
790 * the network containing the address(es) of the link.
792 * If our interface is broken, switch to using the other guy.
794 ifp1 = ifwithaddr(dst, 1, 1);
796 && (!(ifp1->int_state & IS_BROKE)
797 || (ifp1->int_state & IS_PASSIVE)))
800 /* Look for the route in our table.
802 rt = rtget(dst, mask);
804 /* Consider adding the route if we do not already have it.
807 /* Ignore unknown routes being poisoned.
809 if (new->rts_metric == HOPCNT_INFINITY)
812 /* Ignore the route if it points to us */
814 && 0 != ifwithaddr(n->n_nhop, 1, 0))
817 /* If something has not gone crazy and tried to fill
818 * our memory, accept the new route.
820 if (total_routes < MAX_ROUTES)
821 rtadd(dst, mask, 0, new);
825 /* We already know about the route. Consider this update.
827 * If (rt->rt_state & RS_NET_SYN), then this route
828 * is the same as a network route we have inferred
829 * for subnets we know, in order to tell RIPv1 routers
832 * It is impossible to tell if the route is coming
833 * from a distant RIPv2 router with the standard
834 * netmask because that router knows about the entire
835 * network, or if it is a round-about echo of a
836 * synthetic, RIPv1 network route of our own.
837 * The worst is that both kinds of routes might be
838 * received, and the bad one might have the smaller
839 * metric. Partly solve this problem by never
840 * aggregating into such a route. Also keep it
841 * around as long as the interface exists.
844 rts0 = rt->rt_spares;
845 for (rts = rts0, i = NUM_SPARES; i != 0; i--, rts++) {
846 if (rts->rts_router == new->rts_router)
848 /* Note the worst slot to reuse,
849 * other than the current slot.
851 if (rts0 == rt->rt_spares
852 || BETTER_LINK(rt, rts0, rts))
856 /* Found a route from the router already in the table.
859 /* If the new route is a route broken down from an
860 * aggregated route, and if the previous route is either
861 * not a broken down route or was broken down from a finer
862 * netmask, and if the previous route is current,
863 * then forget this one.
865 if (new->rts_de_ag > rts->rts_de_ag
866 && now_stale <= rts->rts_time)
869 /* Keep poisoned routes around only long enough to pass
870 * the poison on. Use a new timestamp for good routes.
872 if (rts->rts_metric == HOPCNT_INFINITY
873 && new->rts_metric == HOPCNT_INFINITY)
874 new->rts_time = rts->rts_time;
876 /* If this is an update for the router we currently prefer,
879 if (i == NUM_SPARES) {
880 rtchange(rt, rt->rt_state, new, 0);
881 /* If the route got worse, check for something better.
883 if (new->rts_metric > rts->rts_metric)
888 /* This is an update for a spare route.
889 * Finished if the route is unchanged.
891 if (rts->rts_gate == new->rts_gate
892 && rts->rts_metric == new->rts_metric
893 && rts->rts_tag == new->rts_tag) {
894 trace_upslot(rt, rts, new);
898 /* Forget it if it has gone bad.
900 if (new->rts_metric == HOPCNT_INFINITY) {
906 /* The update is for a route we know about,
907 * but not from a familiar router.
909 * Ignore the route if it points to us.
912 && 0 != ifwithaddr(n->n_nhop, 1, 0))
915 /* the loop above set rts0=worst spare */
918 /* Save the route as a spare only if it has
919 * a better metric than our worst spare.
920 * This also ignores poisoned routes (those
921 * received with metric HOPCNT_INFINITY).
923 if (new->rts_metric >= rts->rts_metric)
927 trace_upslot(rt, rts, new);
930 /* try to switch to a better route */
935 static int /* 0 if bad */
936 ck_passwd(struct interface *aifp,
940 struct msg_limit *use_authp)
942 # define NA (rip->rip_auths)
946 u_char hash[RIP_AUTH_PW_LEN];
949 assert(aifp != NULL);
950 if ((void *)NA >= lim || NA->a_family != RIP_AF_AUTH) {
951 msglim(use_authp, from, "missing password from %s",
956 /* accept any current (+/- 24 hours) password
958 for (ap = aifp->int_auth, i = 0; i < MAX_AUTH_KEYS; i++, ap++) {
959 if (ap->type != NA->a_type
960 || (u_long)ap->start > (u_long)clk.tv_sec+DAY
961 || (u_long)ap->end+DAY < (u_long)clk.tv_sec)
964 if (NA->a_type == RIP_AUTH_PW) {
965 if (!memcmp(NA->au.au_pw, ap->key, RIP_AUTH_PW_LEN))
969 /* accept MD5 secret with the right key ID
971 if (NA->au.a_md5.md5_keyid != ap->keyid)
974 len = ntohs(NA->au.a_md5.md5_pkt_len);
975 if ((len-sizeof(*rip)) % sizeof(*NA) != 0
976 || len != (char *)lim-(char*)rip-(int)sizeof(*NA)) {
977 msglim(use_authp, from,
978 "wrong MD5 RIPv2 packet length of %d"
979 " instead of %d from %s",
980 len, (int)((char *)lim-(char *)rip
985 na2 = (struct netauth *)((char *)rip+len);
987 /* Given a good hash value, these are not security
988 * problems so be generous and accept the routes,
992 if (NA->au.a_md5.md5_auth_len
993 != RIP_AUTH_MD5_HASH_LEN)
994 msglim(use_authp, from,
995 "unknown MD5 RIPv2 auth len %#x"
996 " instead of %#x from %s",
997 NA->au.a_md5.md5_auth_len,
998 (unsigned)RIP_AUTH_MD5_HASH_LEN,
1000 if (na2->a_family != RIP_AF_AUTH)
1001 msglim(use_authp, from,
1002 "unknown MD5 RIPv2 family %#x"
1003 " instead of %#x from %s",
1004 na2->a_family, RIP_AF_AUTH,
1006 if (na2->a_type != ntohs(1))
1007 msglim(use_authp, from,
1008 "MD5 RIPv2 hash has %#x"
1009 " instead of %#x from %s",
1010 na2->a_type, ntohs(1),
1015 MD5Update(&md5_ctx, (u_char *)rip,
1016 len + RIP_AUTH_MD5_HASH_XTRA);
1017 MD5Update(&md5_ctx, ap->key, RIP_AUTH_MD5_KEY_LEN);
1018 MD5Final(hash, &md5_ctx);
1019 if (!memcmp(hash, na2->au.au_pw, sizeof(hash)))
1024 msglim(use_authp, from, "bad password from %s",