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 = NULL;
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);
164 trace_pkt(" discard a request from an indirect router"
165 " (possibly an attack)");
169 if (rip->rip_vers == 0) {
170 msglim(&bad_router, FROM_NADDR,
171 "RIP version 0, cmd %d, packet received from %s",
172 rip->rip_cmd, naddr_ntoa(FROM_NADDR));
174 } else if (rip->rip_vers > RIPv2) {
175 rip->rip_vers = RIPv2;
177 if (cc > (int)OVER_MAXPACKETSIZE) {
178 msglim(&bad_router, FROM_NADDR,
179 "packet at least %d bytes too long received from %s",
180 cc-MAXPACKETSIZE, naddr_ntoa(FROM_NADDR));
185 lim = (struct netinfo *)((char*)rip + cc);
187 /* Notice authentication.
188 * As required by section 4.2 in RFC 1723, discard authenticated
189 * RIPv2 messages, but only if configured for that silliness.
191 * RIPv2 authentication is lame. Why authenticate queries?
192 * Why should a RIPv2 implementation with authentication disabled
193 * not be able to listen to RIPv2 packets with authentication, while
194 * RIPv1 systems will listen? Crazy!
197 && rip->rip_vers == RIPv2
198 && n < lim && n->n_family == RIP_AF_AUTH) {
199 msglim(&use_auth, FROM_NADDR,
200 "RIPv2 message with authentication from %s discarded",
201 naddr_ntoa(FROM_NADDR));
205 switch (rip->rip_cmd) {
207 /* For mere requests, be a little sloppy about the source
212 /* Are we talking to ourself or a remote gateway?
214 ifp1 = ifwithaddr(FROM_NADDR, 0, 1);
216 if (ifp1->int_state & IS_REMOTE) {
219 if (check_remote(aifp)) {
220 aifp->int_act_time = now.tv_sec;
221 (void)if_ok(aifp, "remote ");
223 } else if (from->sin_port == htons(RIP_PORT)) {
224 trace_pkt(" discard our own RIP request");
229 /* did the request come from a router?
231 if (from->sin_port == htons(RIP_PORT)) {
232 /* yes, ignore the request if RIP is off so that
233 * the router does not depend on us.
237 && IS_RIP_OUT_OFF(aifp->int_state))) {
238 trace_pkt(" discard request while RIP off");
243 /* According to RFC 1723, we should ignore unauthenticated
244 * queries. That is too silly to bother with. Sheesh!
245 * Are forwarding tables supposed to be secret, when
246 * a bad guy can infer them with test traffic? When RIP
247 * is still the most common router-discovery protocol
248 * and so hosts need to send queries that will be answered?
249 * What about `rtquery`?
250 * Maybe on firewalls you'd care, but not enough to
251 * give up the diagnostic facilities of remote probing.
255 msglim(&bad_len, FROM_NADDR, "empty request from %s",
256 naddr_ntoa(FROM_NADDR));
259 if (cc%sizeof(*n) != sizeof(struct rip)%sizeof(*n)) {
260 msglim(&bad_len, FROM_NADDR,
261 "request of bad length (%d) from %s",
262 cc, naddr_ntoa(FROM_NADDR));
265 if (rip->rip_vers == RIPv2
266 && (aifp == NULL || (aifp->int_state & IS_NO_RIPV1_OUT))) {
267 v12buf.buf->rip_vers = RIPv2;
268 /* If we have a secret but it is a cleartext secret,
269 * do not disclose our secret unless the other guy
272 ap = find_auth(aifp);
273 if (ap != NULL && ap->type == RIP_AUTH_PW
274 && n->n_family == RIP_AF_AUTH
275 && !ck_passwd(aifp,rip,lim,FROM_NADDR,&use_auth))
278 v12buf.buf->rip_vers = RIPv1;
281 clr_ws_buf(&v12buf, ap);
284 n->n_metric = ntohl(n->n_metric);
286 /* A single entry with family RIP_AF_UNSPEC and
287 * metric HOPCNT_INFINITY means "all routes".
288 * We respond to routers only if we are acting
289 * as a supplier, or to anyone other than a router
292 if (n->n_family == RIP_AF_UNSPEC
293 && n->n_metric == HOPCNT_INFINITY) {
294 /* Answer a query from a utility program
298 trace_pkt("ignore remote query");
301 if (from->sin_port != htons(RIP_PORT)) {
303 * insecure: query from non-router node
304 * > 1: allow from distant node
305 * > 0: allow from neighbor node
308 if ((aifp != NULL && insecure > 0) ||
309 (aifp == NULL && insecure > 1))
310 supply(from, aifp, OUT_QUERY, 0,
314 trace_pkt("Warning: "
315 "possible attack detected");
319 /* A router trying to prime its tables.
320 * Filter the answer in the about same way
321 * broadcasts are filtered.
323 * Only answer a router if we are a supplier
324 * to keep an unwary host that is just starting
325 * from picking us as a router.
328 trace_pkt("ignore distant router");
332 || IS_RIP_OFF(aifp->int_state)) {
333 trace_pkt("ignore; not supplying");
337 /* Do not answer a RIPv1 router if
338 * we are sending RIPv2. But do offer
339 * poor man's router discovery.
341 if ((aifp->int_state & IS_NO_RIPV1_OUT)
342 && rip->rip_vers == RIPv1) {
343 if (!(aifp->int_state & IS_PM_RDISC)) {
344 trace_pkt("ignore; sending RIPv2");
348 v12buf.n->n_family = RIP_AF_INET;
349 v12buf.n->n_dst = RIP_DEFAULT;
350 i = aifp->int_d_metric;
351 if (NULL != (rt = rtget(RIP_DEFAULT, 0))) {
354 +aifp->int_adj_outmetric
359 v12buf.n->n_metric = htonl(i);
364 /* Respond with RIPv1 instead of RIPv2 if
365 * that is what we are broadcasting on the
366 * interface to keep the remote router from
367 * getting the wrong initial idea of the
370 supply(from, aifp, OUT_UNICAST, 0,
371 (aifp->int_state & IS_NO_RIPV1_OUT)
377 /* Ignore authentication */
378 if (n->n_family == RIP_AF_AUTH)
381 if (n->n_family != RIP_AF_INET) {
382 msglim(&bad_router, FROM_NADDR,
383 "request from %s for unsupported"
385 naddr_ntoa(FROM_NADDR),
387 naddr_ntoa(n->n_dst));
391 /* We are being asked about a specific destination.
394 if (!check_dst(dst)) {
395 msglim(&bad_router, FROM_NADDR,
396 "bad queried destination %s from %s",
398 naddr_ntoa(FROM_NADDR));
402 /* decide what mask was intended */
403 if (rip->rip_vers == RIPv1
404 || 0 == (mask = ntohl(n->n_mask))
405 || 0 != (ntohl(dst) & ~mask))
406 mask = ripv1_mask_host(dst, aifp);
408 /* try to find the answer */
409 rt = rtget(dst, mask);
410 if (!rt && dst != RIP_DEFAULT)
411 rt = rtfind(n->n_dst);
413 if (v12buf.buf->rip_vers != RIPv1)
414 v12buf.n->n_mask = mask;
416 /* we do not have the answer */
417 v12buf.n->n_metric = HOPCNT_INFINITY;
419 /* we have the answer, so compute the
420 * right metric and next hop.
422 v12buf.n->n_family = RIP_AF_INET;
423 v12buf.n->n_dst = dst;
428 j += (aifp->int_metric
429 + aifp->int_adj_outmetric);
430 if (j < HOPCNT_INFINITY)
431 v12buf.n->n_metric = j;
433 v12buf.n->n_metric = HOPCNT_INFINITY;
434 if (v12buf.buf->rip_vers != RIPv1) {
435 v12buf.n->n_tag = rt->rt_tag;
436 v12buf.n->n_mask = mask;
438 && on_net(rt->rt_gate,
441 && rt->rt_gate != aifp->int_addr)
442 v12buf.n->n_nhop = rt->rt_gate;
445 v12buf.n->n_metric = htonl(v12buf.n->n_metric);
447 /* Stop paying attention if we fill the output buffer.
449 if (++v12buf.n >= v12buf.lim)
453 /* Send the answer about specific routes.
455 if (ap != NULL && ap->type == RIP_AUTH_MD5)
456 end_md5_auth(&v12buf, ap);
458 if (from->sin_port != htons(RIP_PORT)) {
460 (void)output(OUT_QUERY, from, aifp,
462 ((char *)v12buf.n - (char*)v12buf.buf));
463 } else if (supplier) {
464 (void)output(OUT_UNICAST, from, aifp,
466 ((char *)v12buf.n - (char*)v12buf.buf));
468 /* Only answer a router if we are a supplier
469 * to keep an unwary host that is just starting
470 * from picking us an a router.
477 case RIPCMD_TRACEOFF:
478 /* Notice that trace messages are turned off for all possible
479 * abuse if _PATH_TRACE is undefined in pathnames.h.
480 * Notice also that because of the way the trace file is
481 * handled in trace.c, no abuse is plausible even if
482 * _PATH_TRACE_ is defined.
484 * First verify message came from a privileged port. */
485 if (ntohs(from->sin_port) > IPPORT_RESERVED) {
486 msglog("trace command from untrusted port on %s",
487 naddr_ntoa(FROM_NADDR));
491 msglog("trace command from unknown router %s",
492 naddr_ntoa(FROM_NADDR));
495 if (rip->rip_cmd == RIPCMD_TRACEON) {
496 rip->rip_tracefile[cc-4] = '\0';
497 set_tracefile((char*)rip->rip_tracefile,
498 "trace command: %s\n", 0);
500 trace_off("tracing turned off by %s",
501 naddr_ntoa(FROM_NADDR));
505 case RIPCMD_RESPONSE:
506 if (cc%sizeof(*n) != sizeof(struct rip)%sizeof(*n)) {
507 msglim(&bad_len, FROM_NADDR,
508 "response of bad length (%d) from %s",
509 cc, naddr_ntoa(FROM_NADDR));
512 /* verify message came from a router */
513 if (from->sin_port != ntohs(RIP_PORT)) {
514 msglim(&bad_router, FROM_NADDR,
515 " discard RIP response from unknown port"
517 ntohs(from->sin_port), naddr_ntoa(FROM_NADDR));
522 trace_pkt(" discard response while RIP off");
526 /* Are we talking to ourself or a remote gateway?
528 ifp1 = ifwithaddr(FROM_NADDR, 0, 1);
530 if (ifp1->int_state & IS_REMOTE) {
533 if (check_remote(aifp)) {
534 aifp->int_act_time = now.tv_sec;
535 (void)if_ok(aifp, "remote ");
538 trace_pkt(" discard our own RIP response");
543 /* Accept routing packets from routers directly connected
544 * via broadcast or point-to-point networks, and from
545 * those listed in /etc/gateways.
548 msglim(&unk_router, FROM_NADDR,
549 " discard response from %s"
550 " via unexpected interface",
551 naddr_ntoa(FROM_NADDR));
554 if (IS_RIP_IN_OFF(aifp->int_state)) {
555 trace_pkt(" discard RIPv%d response"
556 " via disabled interface %s",
557 rip->rip_vers, aifp->int_name);
562 msglim(&bad_len, FROM_NADDR, "empty response from %s",
563 naddr_ntoa(FROM_NADDR));
567 if (((aifp->int_state & IS_NO_RIPV1_IN)
568 && rip->rip_vers == RIPv1)
569 || ((aifp->int_state & IS_NO_RIPV2_IN)
570 && rip->rip_vers != RIPv1)) {
571 trace_pkt(" discard RIPv%d response",
576 /* Ignore routes via dead interface.
578 if (aifp->int_state & IS_BROKE) {
579 trace_pkt("discard response via broken interface %s",
584 /* If the interface cares, ignore bad routers.
585 * Trace but do not log this problem, because where it
586 * happens, it happens frequently.
588 if (aifp->int_state & IS_DISTRUST) {
590 while (tg->tgate_addr != FROM_NADDR) {
593 trace_pkt(" discard RIP response"
594 " from untrusted router %s",
595 naddr_ntoa(FROM_NADDR));
601 /* Authenticate the packet if we have a secret.
602 * If we do not have any secrets, ignore the error in
603 * RFC 1723 and accept it regardless.
605 if (aifp->int_auth[0].type != RIP_AUTH_NONE
606 && rip->rip_vers != RIPv1
607 && !ck_passwd(aifp,rip,lim,FROM_NADDR,&use_auth))
611 if (n->n_family == RIP_AF_AUTH)
614 n->n_metric = ntohl(n->n_metric);
616 if (n->n_family != RIP_AF_INET
617 && (n->n_family != RIP_AF_UNSPEC
618 || dst != RIP_DEFAULT)) {
619 msglim(&bad_router, FROM_NADDR,
620 "route from %s to unsupported"
621 " address family=%d destination=%s",
622 naddr_ntoa(FROM_NADDR),
627 if (!check_dst(dst)) {
628 msglim(&bad_router, FROM_NADDR,
629 "bad destination %s from %s",
631 naddr_ntoa(FROM_NADDR));
635 || n->n_metric > HOPCNT_INFINITY) {
636 msglim(&bad_router, FROM_NADDR,
637 "bad metric %d from %s"
638 " for destination %s",
640 naddr_ntoa(FROM_NADDR),
645 /* Notice the next-hop.
648 if (n->n_nhop != 0) {
649 if (rip->rip_vers == RIPv1) {
652 /* Use it only if it is valid. */
653 if (on_net(n->n_nhop,
654 aifp->int_net, aifp->int_mask)
655 && check_dst(n->n_nhop)) {
658 msglim(&bad_nhop, FROM_NADDR,
660 " has bad next hop %s",
661 naddr_ntoa(FROM_NADDR),
663 naddr_ntoa(n->n_nhop));
669 if (rip->rip_vers == RIPv1
670 || 0 == (mask = ntohl(n->n_mask))) {
671 mask = ripv1_mask_host(dst,aifp);
672 } else if ((ntohl(dst) & ~mask) != 0) {
673 msglim(&bad_mask, FROM_NADDR,
674 "router %s sent bad netmask"
676 naddr_ntoa(FROM_NADDR),
681 if (rip->rip_vers == RIPv1)
684 /* Adjust metric according to incoming interface..
686 n->n_metric += (aifp->int_metric
687 + aifp->int_adj_inmetric);
688 if (n->n_metric > HOPCNT_INFINITY)
689 n->n_metric = HOPCNT_INFINITY;
691 /* Should we trust this route from this router? */
692 if (tg && (tn = tg->tgate_nets)->mask != 0) {
693 for (i = 0; i < MAX_TGATE_NETS; i++, tn++) {
694 if (on_net(dst, tn->net, tn->mask)
698 if (i >= MAX_TGATE_NETS || tn->mask == 0) {
699 trace_pkt(" ignored unauthorized %s",
700 addrname(dst,mask,0));
705 /* Recognize and ignore a default route we faked
706 * which is being sent back to us by a machine with
707 * broken split-horizon.
708 * Be a little more paranoid than that, and reject
709 * default routes with the same metric we advertised.
711 if (aifp->int_d_metric != 0
712 && dst == RIP_DEFAULT
713 && (int)n->n_metric >= aifp->int_d_metric)
716 /* We can receive aggregated RIPv2 routes that must
717 * be broken down before they are transmitted by
718 * RIPv1 via an interface on a subnet.
719 * We might also receive the same routes aggregated
720 * via other RIPv2 interfaces.
721 * This could cause duplicate routes to be sent on
722 * the RIPv1 interfaces. "Longest matching variable
723 * length netmasks" lets RIPv2 listeners understand,
724 * but breaking down the aggregated routes for RIPv1
725 * listeners can produce duplicate routes.
727 * Breaking down aggregated routes here bloats
728 * the daemon table, but does not hurt the kernel
729 * table, since routes are always aggregated for
732 * Notice that this does not break down network
733 * routes corresponding to subnets. This is part
734 * of the defense against RS_NET_SYN.
737 && (((rt = rtget(dst,mask)) == NULL
738 || !(rt->rt_state & RS_NET_SYN)))
739 && (v1_mask = ripv1_mask_net(dst,0)) > mask) {
740 ddst_h = v1_mask & -v1_mask;
741 i = (v1_mask & ~mask)/ddst_h;
743 /* Punt if we would have to generate
744 * an unreasonable number of routes.
747 trace_misc("accept %s-->%s as 1"
748 " instead of %d routes",
749 addrname(dst,mask,0),
750 naddr_ntoa(FROM_NADDR),
761 new.rts_router = FROM_NADDR;
762 new.rts_metric = n->n_metric;
763 new.rts_tag = n->n_tag;
764 new.rts_time = now.tv_sec;
769 input_route(dst, mask, &new, n);
772 dst = htonl(ntohl(dst) + ddst_h);
781 /* Process a single input route.
784 input_route(naddr dst, /* network order */
786 struct rt_spare *new,
791 struct rt_spare *rts, *rts0;
792 struct interface *ifp1;
795 /* See if the other guy is telling us to send our packets to him.
796 * Sometimes network routes arrive over a point-to-point link for
797 * the network containing the address(es) of the link.
799 * If our interface is broken, switch to using the other guy.
801 ifp1 = ifwithaddr(dst, 1, 1);
803 && (!(ifp1->int_state & IS_BROKE)
804 || (ifp1->int_state & IS_PASSIVE)))
807 /* Look for the route in our table.
809 rt = rtget(dst, mask);
811 /* Consider adding the route if we do not already have it.
814 /* Ignore unknown routes being poisoned.
816 if (new->rts_metric == HOPCNT_INFINITY)
819 /* Ignore the route if it points to us */
821 && ifwithaddr(n->n_nhop, 1, 0) != NULL)
824 /* If something has not gone crazy and tried to fill
825 * our memory, accept the new route.
827 if (total_routes < MAX_ROUTES)
828 rtadd(dst, mask, 0, new);
832 /* We already know about the route. Consider this update.
834 * If (rt->rt_state & RS_NET_SYN), then this route
835 * is the same as a network route we have inferred
836 * for subnets we know, in order to tell RIPv1 routers
839 * It is impossible to tell if the route is coming
840 * from a distant RIPv2 router with the standard
841 * netmask because that router knows about the entire
842 * network, or if it is a round-about echo of a
843 * synthetic, RIPv1 network route of our own.
844 * The worst is that both kinds of routes might be
845 * received, and the bad one might have the smaller
846 * metric. Partly solve this problem by never
847 * aggregating into such a route. Also keep it
848 * around as long as the interface exists.
851 rts0 = rt->rt_spares;
852 for (rts = rts0, i = NUM_SPARES; i != 0; i--, rts++) {
853 if (rts->rts_router == new->rts_router)
855 /* Note the worst slot to reuse,
856 * other than the current slot.
858 if (rts0 == rt->rt_spares
859 || BETTER_LINK(rt, rts0, rts))
863 /* Found a route from the router already in the table.
866 /* If the new route is a route broken down from an
867 * aggregated route, and if the previous route is either
868 * not a broken down route or was broken down from a finer
869 * netmask, and if the previous route is current,
870 * then forget this one.
872 if (new->rts_de_ag > rts->rts_de_ag
873 && now_stale <= rts->rts_time)
876 /* Keep poisoned routes around only long enough to pass
877 * the poison on. Use a new timestamp for good routes.
879 if (rts->rts_metric == HOPCNT_INFINITY
880 && new->rts_metric == HOPCNT_INFINITY)
881 new->rts_time = rts->rts_time;
883 /* If this is an update for the router we currently prefer,
886 if (i == NUM_SPARES) {
887 rtchange(rt, rt->rt_state, new, 0);
888 /* If the route got worse, check for something better.
890 if (new->rts_metric > rts->rts_metric)
895 /* This is an update for a spare route.
896 * Finished if the route is unchanged.
898 if (rts->rts_gate == new->rts_gate
899 && rts->rts_metric == new->rts_metric
900 && rts->rts_tag == new->rts_tag) {
901 trace_upslot(rt, rts, new);
905 /* Forget it if it has gone bad.
907 if (new->rts_metric == HOPCNT_INFINITY) {
913 /* The update is for a route we know about,
914 * but not from a familiar router.
916 * Ignore the route if it points to us.
919 && NULL != ifwithaddr(n->n_nhop, 1, 0))
922 /* the loop above set rts0=worst spare */
925 /* Save the route as a spare only if it has
926 * a better metric than our worst spare.
927 * This also ignores poisoned routes (those
928 * received with metric HOPCNT_INFINITY).
930 if (new->rts_metric >= rts->rts_metric)
934 trace_upslot(rt, rts, new);
937 /* try to switch to a better route */
942 static int /* 0 if bad */
943 ck_passwd(struct interface *aifp,
947 struct msg_limit *use_authp)
949 # define NA (rip->rip_auths)
953 u_char hash[RIP_AUTH_PW_LEN];
956 assert(aifp != NULL);
957 if ((void *)NA >= lim || NA->a_family != RIP_AF_AUTH) {
958 msglim(use_authp, from, "missing password from %s",
963 /* accept any current (+/- 24 hours) password
965 for (ap = aifp->int_auth, i = 0; i < MAX_AUTH_KEYS; i++, ap++) {
966 if (ap->type != NA->a_type
967 || (u_long)ap->start > (u_long)clk.tv_sec+DAY
968 || (u_long)ap->end+DAY < (u_long)clk.tv_sec)
971 if (NA->a_type == RIP_AUTH_PW) {
972 if (!memcmp(NA->au.au_pw, ap->key, RIP_AUTH_PW_LEN))
976 /* accept MD5 secret with the right key ID
978 if (NA->au.a_md5.md5_keyid != ap->keyid)
981 len = ntohs(NA->au.a_md5.md5_pkt_len);
982 if ((len-sizeof(*rip)) % sizeof(*NA) != 0
983 || len != (char *)lim-(char*)rip-(int)sizeof(*NA)) {
984 msglim(use_authp, from,
985 "wrong MD5 RIPv2 packet length of %d"
986 " instead of %d from %s",
987 len, (int)((char *)lim-(char *)rip
992 na2 = (struct netauth *)((char *)rip+len);
994 /* Given a good hash value, these are not security
995 * problems so be generous and accept the routes,
999 if (NA->au.a_md5.md5_auth_len
1000 != RIP_AUTH_MD5_HASH_LEN)
1001 msglim(use_authp, from,
1002 "unknown MD5 RIPv2 auth len %#x"
1003 " instead of %#x from %s",
1004 NA->au.a_md5.md5_auth_len,
1005 (unsigned)RIP_AUTH_MD5_HASH_LEN,
1007 if (na2->a_family != RIP_AF_AUTH)
1008 msglim(use_authp, from,
1009 "unknown MD5 RIPv2 family %#x"
1010 " instead of %#x from %s",
1011 na2->a_family, RIP_AF_AUTH,
1013 if (na2->a_type != ntohs(1))
1014 msglim(use_authp, from,
1015 "MD5 RIPv2 hash has %#x"
1016 " instead of %#x from %s",
1017 na2->a_type, ntohs(1),
1022 MD5Update(&md5_ctx, (u_char *)rip,
1023 len + RIP_AUTH_MD5_HASH_XTRA);
1024 MD5Update(&md5_ctx, ap->key, RIP_AUTH_MD5_KEY_LEN);
1025 MD5Final(hash, &md5_ctx);
1026 if (!memcmp(hash, na2->au.au_pw, sizeof(hash)))
1031 msglim(use_authp, from, "bad password from %s",