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
291 if (from->sin_port != htons(RIP_PORT)) {
293 * insecure: query from non-router node
294 * > 1: allow from distant node
295 * > 0: allow from neighbor node
298 if ((aifp != NULL && insecure > 0) ||
299 (aifp == NULL && insecure > 1))
300 supply(from, aifp, OUT_QUERY, 0,
301 rip->rip_vers, ap != 0);
303 trace_pkt("Warning: "
304 "possible attack detected");
308 /* A router trying to prime its tables.
309 * Filter the answer in the about same way
310 * broadcasts are filtered.
312 * Only answer a router if we are a supplier
313 * to keep an unwary host that is just starting
314 * from picking us as a router.
317 trace_pkt("ignore distant router");
321 || IS_RIP_OFF(aifp->int_state)) {
322 trace_pkt("ignore; not supplying");
326 /* Do not answer a RIPv1 router if
327 * we are sending RIPv2. But do offer
328 * poor man's router discovery.
330 if ((aifp->int_state & IS_NO_RIPV1_OUT)
331 && rip->rip_vers == RIPv1) {
332 if (!(aifp->int_state & IS_PM_RDISC)) {
333 trace_pkt("ignore; sending RIPv2");
337 v12buf.n->n_family = RIP_AF_INET;
338 v12buf.n->n_dst = RIP_DEFAULT;
339 i = aifp->int_d_metric;
340 if (0 != (rt = rtget(RIP_DEFAULT, 0))) {
343 +aifp->int_adj_outmetric
348 v12buf.n->n_metric = htonl(i);
353 /* Respond with RIPv1 instead of RIPv2 if
354 * that is what we are broadcasting on the
355 * interface to keep the remote router from
356 * getting the wrong initial idea of the
359 supply(from, aifp, OUT_UNICAST, 0,
360 (aifp->int_state & IS_NO_RIPV1_OUT)
366 /* Ignore authentication */
367 if (n->n_family == RIP_AF_AUTH)
370 if (n->n_family != RIP_AF_INET) {
371 msglim(&bad_router, FROM_NADDR,
372 "request from %s for unsupported"
374 naddr_ntoa(FROM_NADDR),
376 naddr_ntoa(n->n_dst));
380 /* We are being asked about a specific destination.
383 if (!check_dst(dst)) {
384 msglim(&bad_router, FROM_NADDR,
385 "bad queried destination %s from %s",
387 naddr_ntoa(FROM_NADDR));
391 /* decide what mask was intended */
392 if (rip->rip_vers == RIPv1
393 || 0 == (mask = ntohl(n->n_mask))
394 || 0 != (ntohl(dst) & ~mask))
395 mask = ripv1_mask_host(dst, aifp);
397 /* try to find the answer */
398 rt = rtget(dst, mask);
399 if (!rt && dst != RIP_DEFAULT)
400 rt = rtfind(n->n_dst);
402 if (v12buf.buf->rip_vers != RIPv1)
403 v12buf.n->n_mask = mask;
405 /* we do not have the answer */
406 v12buf.n->n_metric = HOPCNT_INFINITY;
408 /* we have the answer, so compute the
409 * right metric and next hop.
411 v12buf.n->n_family = RIP_AF_INET;
412 v12buf.n->n_dst = dst;
417 j += (aifp->int_metric
418 + aifp->int_adj_outmetric);
419 if (j < HOPCNT_INFINITY)
420 v12buf.n->n_metric = j;
422 v12buf.n->n_metric = HOPCNT_INFINITY;
423 if (v12buf.buf->rip_vers != RIPv1) {
424 v12buf.n->n_tag = rt->rt_tag;
425 v12buf.n->n_mask = mask;
427 && on_net(rt->rt_gate,
430 && rt->rt_gate != aifp->int_addr)
431 v12buf.n->n_nhop = rt->rt_gate;
434 v12buf.n->n_metric = htonl(v12buf.n->n_metric);
436 /* Stop paying attention if we fill the output buffer.
438 if (++v12buf.n >= v12buf.lim)
442 /* Send the answer about specific routes.
444 if (ap != 0 && ap->type == RIP_AUTH_MD5)
445 end_md5_auth(&v12buf, ap);
447 if (from->sin_port != htons(RIP_PORT)) {
449 (void)output(OUT_QUERY, from, aifp,
451 ((char *)v12buf.n - (char*)v12buf.buf));
452 } else if (supplier) {
453 (void)output(OUT_UNICAST, from, aifp,
455 ((char *)v12buf.n - (char*)v12buf.buf));
457 /* Only answer a router if we are a supplier
458 * to keep an unwary host that is just starting
459 * from picking us an a router.
466 case RIPCMD_TRACEOFF:
467 /* Notice that trace messages are turned off for all possible
468 * abuse if _PATH_TRACE is undefined in pathnames.h.
469 * Notice also that because of the way the trace file is
470 * handled in trace.c, no abuse is plausible even if
471 * _PATH_TRACE_ is defined.
473 * First verify message came from a privileged port. */
474 if (ntohs(from->sin_port) > IPPORT_RESERVED) {
475 msglog("trace command from untrusted port on %s",
476 naddr_ntoa(FROM_NADDR));
480 msglog("trace command from unknown router %s",
481 naddr_ntoa(FROM_NADDR));
484 if (rip->rip_cmd == RIPCMD_TRACEON) {
485 rip->rip_tracefile[cc-4] = '\0';
486 set_tracefile((char*)rip->rip_tracefile,
487 "trace command: %s\n", 0);
489 trace_off("tracing turned off by %s",
490 naddr_ntoa(FROM_NADDR));
494 case RIPCMD_RESPONSE:
495 if (cc%sizeof(*n) != sizeof(struct rip)%sizeof(*n)) {
496 msglim(&bad_len, FROM_NADDR,
497 "response of bad length (%d) from %s",
498 cc, naddr_ntoa(FROM_NADDR));
501 /* verify message came from a router */
502 if (from->sin_port != ntohs(RIP_PORT)) {
503 msglim(&bad_router, FROM_NADDR,
504 " discard RIP response from unknown port"
506 ntohs(from->sin_port), naddr_ntoa(FROM_NADDR));
511 trace_pkt(" discard response while RIP off");
515 /* Are we talking to ourself or a remote gateway?
517 ifp1 = ifwithaddr(FROM_NADDR, 0, 1);
519 if (ifp1->int_state & IS_REMOTE) {
522 if (check_remote(aifp)) {
523 aifp->int_act_time = now.tv_sec;
524 (void)if_ok(aifp, "remote ");
527 trace_pkt(" discard our own RIP response");
532 /* Accept routing packets from routers directly connected
533 * via broadcast or point-to-point networks, and from
534 * those listed in /etc/gateways.
537 msglim(&unk_router, FROM_NADDR,
538 " discard response from %s"
539 " via unexpected interface",
540 naddr_ntoa(FROM_NADDR));
543 if (IS_RIP_IN_OFF(aifp->int_state)) {
544 trace_pkt(" discard RIPv%d response"
545 " via disabled interface %s",
546 rip->rip_vers, aifp->int_name);
551 msglim(&bad_len, FROM_NADDR, "empty response from %s",
552 naddr_ntoa(FROM_NADDR));
556 if (((aifp->int_state & IS_NO_RIPV1_IN)
557 && rip->rip_vers == RIPv1)
558 || ((aifp->int_state & IS_NO_RIPV2_IN)
559 && rip->rip_vers != RIPv1)) {
560 trace_pkt(" discard RIPv%d response",
565 /* Ignore routes via dead interface.
567 if (aifp->int_state & IS_BROKE) {
568 trace_pkt("discard response via broken interface %s",
573 /* If the interface cares, ignore bad routers.
574 * Trace but do not log this problem, because where it
575 * happens, it happens frequently.
577 if (aifp->int_state & IS_DISTRUST) {
579 while (tg->tgate_addr != FROM_NADDR) {
582 trace_pkt(" discard RIP response"
583 " from untrusted router %s",
584 naddr_ntoa(FROM_NADDR));
590 /* Authenticate the packet if we have a secret.
591 * If we do not have any secrets, ignore the error in
592 * RFC 1723 and accept it regardless.
594 if (aifp->int_auth[0].type != RIP_AUTH_NONE
595 && rip->rip_vers != RIPv1
596 && !ck_passwd(aifp,rip,lim,FROM_NADDR,&use_auth))
600 if (n->n_family == RIP_AF_AUTH)
603 n->n_metric = ntohl(n->n_metric);
605 if (n->n_family != RIP_AF_INET
606 && (n->n_family != RIP_AF_UNSPEC
607 || dst != RIP_DEFAULT)) {
608 msglim(&bad_router, FROM_NADDR,
609 "route from %s to unsupported"
610 " address family=%d destination=%s",
611 naddr_ntoa(FROM_NADDR),
616 if (!check_dst(dst)) {
617 msglim(&bad_router, FROM_NADDR,
618 "bad destination %s from %s",
620 naddr_ntoa(FROM_NADDR));
624 || n->n_metric > HOPCNT_INFINITY) {
625 msglim(&bad_router, FROM_NADDR,
626 "bad metric %d from %s"
627 " for destination %s",
629 naddr_ntoa(FROM_NADDR),
634 /* Notice the next-hop.
637 if (n->n_nhop != 0) {
638 if (rip->rip_vers == RIPv1) {
641 /* Use it only if it is valid. */
642 if (on_net(n->n_nhop,
643 aifp->int_net, aifp->int_mask)
644 && check_dst(n->n_nhop)) {
647 msglim(&bad_nhop, FROM_NADDR,
649 " has bad next hop %s",
650 naddr_ntoa(FROM_NADDR),
652 naddr_ntoa(n->n_nhop));
658 if (rip->rip_vers == RIPv1
659 || 0 == (mask = ntohl(n->n_mask))) {
660 mask = ripv1_mask_host(dst,aifp);
661 } else if ((ntohl(dst) & ~mask) != 0) {
662 msglim(&bad_mask, FROM_NADDR,
663 "router %s sent bad netmask"
665 naddr_ntoa(FROM_NADDR),
670 if (rip->rip_vers == RIPv1)
673 /* Adjust metric according to incoming interface..
675 n->n_metric += (aifp->int_metric
676 + aifp->int_adj_inmetric);
677 if (n->n_metric > HOPCNT_INFINITY)
678 n->n_metric = HOPCNT_INFINITY;
680 /* Should we trust this route from this router? */
681 if (tg && (tn = tg->tgate_nets)->mask != 0) {
682 for (i = 0; i < MAX_TGATE_NETS; i++, tn++) {
683 if (on_net(dst, tn->net, tn->mask)
687 if (i >= MAX_TGATE_NETS || tn->mask == 0) {
688 trace_pkt(" ignored unauthorized %s",
689 addrname(dst,mask,0));
694 /* Recognize and ignore a default route we faked
695 * which is being sent back to us by a machine with
696 * broken split-horizon.
697 * Be a little more paranoid than that, and reject
698 * default routes with the same metric we advertised.
700 if (aifp->int_d_metric != 0
701 && dst == RIP_DEFAULT
702 && (int)n->n_metric >= aifp->int_d_metric)
705 /* We can receive aggregated RIPv2 routes that must
706 * be broken down before they are transmitted by
707 * RIPv1 via an interface on a subnet.
708 * We might also receive the same routes aggregated
709 * via other RIPv2 interfaces.
710 * This could cause duplicate routes to be sent on
711 * the RIPv1 interfaces. "Longest matching variable
712 * length netmasks" lets RIPv2 listeners understand,
713 * but breaking down the aggregated routes for RIPv1
714 * listeners can produce duplicate routes.
716 * Breaking down aggregated routes here bloats
717 * the daemon table, but does not hurt the kernel
718 * table, since routes are always aggregated for
721 * Notice that this does not break down network
722 * routes corresponding to subnets. This is part
723 * of the defense against RS_NET_SYN.
726 && (((rt = rtget(dst,mask)) == 0
727 || !(rt->rt_state & RS_NET_SYN)))
728 && (v1_mask = ripv1_mask_net(dst,0)) > mask) {
729 ddst_h = v1_mask & -v1_mask;
730 i = (v1_mask & ~mask)/ddst_h;
732 /* Punt if we would have to generate
733 * an unreasonable number of routes.
736 trace_misc("accept %s-->%s as 1"
737 " instead of %d routes",
738 addrname(dst,mask,0),
739 naddr_ntoa(FROM_NADDR),
750 new.rts_router = FROM_NADDR;
751 new.rts_metric = n->n_metric;
752 new.rts_tag = n->n_tag;
753 new.rts_time = now.tv_sec;
758 input_route(dst, mask, &new, n);
761 dst = htonl(ntohl(dst) + ddst_h);
770 /* Process a single input route.
773 input_route(naddr dst, /* network order */
775 struct rt_spare *new,
780 struct rt_spare *rts, *rts0;
781 struct interface *ifp1;
784 /* See if the other guy is telling us to send our packets to him.
785 * Sometimes network routes arrive over a point-to-point link for
786 * the network containing the address(es) of the link.
788 * If our interface is broken, switch to using the other guy.
790 ifp1 = ifwithaddr(dst, 1, 1);
792 && (!(ifp1->int_state & IS_BROKE)
793 || (ifp1->int_state & IS_PASSIVE)))
796 /* Look for the route in our table.
798 rt = rtget(dst, mask);
800 /* Consider adding the route if we do not already have it.
803 /* Ignore unknown routes being poisoned.
805 if (new->rts_metric == HOPCNT_INFINITY)
808 /* Ignore the route if it points to us */
810 && 0 != ifwithaddr(n->n_nhop, 1, 0))
813 /* If something has not gone crazy and tried to fill
814 * our memory, accept the new route.
816 if (total_routes < MAX_ROUTES)
817 rtadd(dst, mask, 0, new);
821 /* We already know about the route. Consider this update.
823 * If (rt->rt_state & RS_NET_SYN), then this route
824 * is the same as a network route we have inferred
825 * for subnets we know, in order to tell RIPv1 routers
828 * It is impossible to tell if the route is coming
829 * from a distant RIPv2 router with the standard
830 * netmask because that router knows about the entire
831 * network, or if it is a round-about echo of a
832 * synthetic, RIPv1 network route of our own.
833 * The worst is that both kinds of routes might be
834 * received, and the bad one might have the smaller
835 * metric. Partly solve this problem by never
836 * aggregating into such a route. Also keep it
837 * around as long as the interface exists.
840 rts0 = rt->rt_spares;
841 for (rts = rts0, i = NUM_SPARES; i != 0; i--, rts++) {
842 if (rts->rts_router == new->rts_router)
844 /* Note the worst slot to reuse,
845 * other than the current slot.
847 if (rts0 == rt->rt_spares
848 || BETTER_LINK(rt, rts0, rts))
852 /* Found a route from the router already in the table.
855 /* If the new route is a route broken down from an
856 * aggregated route, and if the previous route is either
857 * not a broken down route or was broken down from a finer
858 * netmask, and if the previous route is current,
859 * then forget this one.
861 if (new->rts_de_ag > rts->rts_de_ag
862 && now_stale <= rts->rts_time)
865 /* Keep poisoned routes around only long enough to pass
866 * the poison on. Use a new timestamp for good routes.
868 if (rts->rts_metric == HOPCNT_INFINITY
869 && new->rts_metric == HOPCNT_INFINITY)
870 new->rts_time = rts->rts_time;
872 /* If this is an update for the router we currently prefer,
875 if (i == NUM_SPARES) {
876 rtchange(rt, rt->rt_state, new, 0);
877 /* If the route got worse, check for something better.
879 if (new->rts_metric > rts->rts_metric)
884 /* This is an update for a spare route.
885 * Finished if the route is unchanged.
887 if (rts->rts_gate == new->rts_gate
888 && rts->rts_metric == new->rts_metric
889 && rts->rts_tag == new->rts_tag) {
890 trace_upslot(rt, rts, new);
894 /* Forget it if it has gone bad.
896 if (new->rts_metric == HOPCNT_INFINITY) {
902 /* The update is for a route we know about,
903 * but not from a familiar router.
905 * Ignore the route if it points to us.
908 && 0 != ifwithaddr(n->n_nhop, 1, 0))
911 /* the loop above set rts0=worst spare */
914 /* Save the route as a spare only if it has
915 * a better metric than our worst spare.
916 * This also ignores poisoned routes (those
917 * received with metric HOPCNT_INFINITY).
919 if (new->rts_metric >= rts->rts_metric)
923 trace_upslot(rt, rts, new);
926 /* try to switch to a better route */
931 static int /* 0 if bad */
932 ck_passwd(struct interface *aifp,
936 struct msg_limit *use_authp)
938 # define NA (rip->rip_auths)
942 u_char hash[RIP_AUTH_PW_LEN];
945 assert(aifp != NULL);
946 if ((void *)NA >= lim || NA->a_family != RIP_AF_AUTH) {
947 msglim(use_authp, from, "missing password from %s",
952 /* accept any current (+/- 24 hours) password
954 for (ap = aifp->int_auth, i = 0; i < MAX_AUTH_KEYS; i++, ap++) {
955 if (ap->type != NA->a_type
956 || (u_long)ap->start > (u_long)clk.tv_sec+DAY
957 || (u_long)ap->end+DAY < (u_long)clk.tv_sec)
960 if (NA->a_type == RIP_AUTH_PW) {
961 if (!memcmp(NA->au.au_pw, ap->key, RIP_AUTH_PW_LEN))
965 /* accept MD5 secret with the right key ID
967 if (NA->au.a_md5.md5_keyid != ap->keyid)
970 len = ntohs(NA->au.a_md5.md5_pkt_len);
971 if ((len-sizeof(*rip)) % sizeof(*NA) != 0
972 || len != (char *)lim-(char*)rip-(int)sizeof(*NA)) {
973 msglim(use_authp, from,
974 "wrong MD5 RIPv2 packet length of %d"
975 " instead of %d from %s",
976 len, (int)((char *)lim-(char *)rip
981 na2 = (struct netauth *)((char *)rip+len);
983 /* Given a good hash value, these are not security
984 * problems so be generous and accept the routes,
988 if (NA->au.a_md5.md5_auth_len
989 != RIP_AUTH_MD5_HASH_LEN)
990 msglim(use_authp, from,
991 "unknown MD5 RIPv2 auth len %#x"
992 " instead of %#x from %s",
993 NA->au.a_md5.md5_auth_len,
994 (unsigned)RIP_AUTH_MD5_HASH_LEN,
996 if (na2->a_family != RIP_AF_AUTH)
997 msglim(use_authp, from,
998 "unknown MD5 RIPv2 family %#x"
999 " instead of %#x from %s",
1000 na2->a_family, RIP_AF_AUTH,
1002 if (na2->a_type != ntohs(1))
1003 msglim(use_authp, from,
1004 "MD5 RIPv2 hash has %#x"
1005 " instead of %#x from %s",
1006 na2->a_type, ntohs(1),
1011 MD5Update(&md5_ctx, (u_char *)rip,
1012 len + RIP_AUTH_MD5_HASH_XTRA);
1013 MD5Update(&md5_ctx, ap->key, RIP_AUTH_MD5_KEY_LEN);
1014 MD5Final(hash, &md5_ctx);
1015 if (!memcmp(hash, na2->au.au_pw, sizeof(hash)))
1020 msglim(use_authp, from, "bad password from %s",