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);
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 == 0 || (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 != 0 && 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)) {
302 supply(from, aifp, OUT_QUERY, 0,
303 rip->rip_vers, ap != 0);
307 /* A router trying to prime its tables.
308 * Filter the answer in the about same way
309 * broadcasts are filtered.
311 * Only answer a router if we are a supplier
312 * to keep an unwary host that is just starting
313 * from picking us as a router.
316 trace_pkt("ignore distant router");
320 || IS_RIP_OFF(aifp->int_state)) {
321 trace_pkt("ignore; not supplying");
325 /* Do not answer a RIPv1 router if
326 * we are sending RIPv2. But do offer
327 * poor man's router discovery.
329 if ((aifp->int_state & IS_NO_RIPV1_OUT)
330 && rip->rip_vers == RIPv1) {
331 if (!(aifp->int_state & IS_PM_RDISC)) {
332 trace_pkt("ignore; sending RIPv2");
336 v12buf.n->n_family = RIP_AF_INET;
337 v12buf.n->n_dst = RIP_DEFAULT;
338 i = aifp->int_d_metric;
339 if (0 != (rt = rtget(RIP_DEFAULT, 0))) {
342 +aifp->int_adj_outmetric
347 v12buf.n->n_metric = htonl(i);
352 /* Respond with RIPv1 instead of RIPv2 if
353 * that is what we are broadcasting on the
354 * interface to keep the remote router from
355 * getting the wrong initial idea of the
358 supply(from, aifp, OUT_UNICAST, 0,
359 (aifp->int_state & IS_NO_RIPV1_OUT)
365 /* Ignore authentication */
366 if (n->n_family == RIP_AF_AUTH)
369 if (n->n_family != RIP_AF_INET) {
370 msglim(&bad_router, FROM_NADDR,
371 "request from %s for unsupported"
373 naddr_ntoa(FROM_NADDR),
375 naddr_ntoa(n->n_dst));
379 /* We are being asked about a specific destination.
382 if (!check_dst(dst)) {
383 msglim(&bad_router, FROM_NADDR,
384 "bad queried destination %s from %s",
386 naddr_ntoa(FROM_NADDR));
390 /* decide what mask was intended */
391 if (rip->rip_vers == RIPv1
392 || 0 == (mask = ntohl(n->n_mask))
393 || 0 != (ntohl(dst) & ~mask))
394 mask = ripv1_mask_host(dst, aifp);
396 /* try to find the answer */
397 rt = rtget(dst, mask);
398 if (!rt && dst != RIP_DEFAULT)
399 rt = rtfind(n->n_dst);
401 if (v12buf.buf->rip_vers != RIPv1)
402 v12buf.n->n_mask = mask;
404 /* we do not have the answer */
405 v12buf.n->n_metric = HOPCNT_INFINITY;
407 /* we have the answer, so compute the
408 * right metric and next hop.
410 v12buf.n->n_family = RIP_AF_INET;
411 v12buf.n->n_dst = dst;
416 j += (aifp->int_metric
417 + aifp->int_adj_outmetric);
418 if (j < HOPCNT_INFINITY)
419 v12buf.n->n_metric = j;
421 v12buf.n->n_metric = HOPCNT_INFINITY;
422 if (v12buf.buf->rip_vers != RIPv1) {
423 v12buf.n->n_tag = rt->rt_tag;
424 v12buf.n->n_mask = mask;
426 && on_net(rt->rt_gate,
429 && rt->rt_gate != aifp->int_addr)
430 v12buf.n->n_nhop = rt->rt_gate;
433 v12buf.n->n_metric = htonl(v12buf.n->n_metric);
435 /* Stop paying attention if we fill the output buffer.
437 if (++v12buf.n >= v12buf.lim)
441 /* Send the answer about specific routes.
443 if (ap != 0 && ap->type == RIP_AUTH_MD5)
444 end_md5_auth(&v12buf, ap);
446 if (from->sin_port != htons(RIP_PORT)) {
448 (void)output(OUT_QUERY, from, aifp,
450 ((char *)v12buf.n - (char*)v12buf.buf));
451 } else if (supplier) {
452 (void)output(OUT_UNICAST, from, aifp,
454 ((char *)v12buf.n - (char*)v12buf.buf));
456 /* Only answer a router if we are a supplier
457 * to keep an unwary host that is just starting
458 * from picking us an a router.
465 case RIPCMD_TRACEOFF:
466 /* Notice that trace messages are turned off for all possible
467 * abuse if _PATH_TRACE is undefined in pathnames.h.
468 * Notice also that because of the way the trace file is
469 * handled in trace.c, no abuse is plausible even if
470 * _PATH_TRACE_ is defined.
472 * First verify message came from a privileged port. */
473 if (ntohs(from->sin_port) > IPPORT_RESERVED) {
474 msglog("trace command from untrusted port on %s",
475 naddr_ntoa(FROM_NADDR));
479 msglog("trace command from unknown router %s",
480 naddr_ntoa(FROM_NADDR));
483 if (rip->rip_cmd == RIPCMD_TRACEON) {
484 rip->rip_tracefile[cc-4] = '\0';
485 set_tracefile((char*)rip->rip_tracefile,
486 "trace command: %s\n", 0);
488 trace_off("tracing turned off by %s",
489 naddr_ntoa(FROM_NADDR));
493 case RIPCMD_RESPONSE:
494 if (cc%sizeof(*n) != sizeof(struct rip)%sizeof(*n)) {
495 msglim(&bad_len, FROM_NADDR,
496 "response of bad length (%d) from %s",
497 cc, naddr_ntoa(FROM_NADDR));
500 /* verify message came from a router */
501 if (from->sin_port != ntohs(RIP_PORT)) {
502 msglim(&bad_router, FROM_NADDR,
503 " discard RIP response from unknown port"
505 ntohs(from->sin_port), naddr_ntoa(FROM_NADDR));
510 trace_pkt(" discard response while RIP off");
514 /* Are we talking to ourself or a remote gateway?
516 ifp1 = ifwithaddr(FROM_NADDR, 0, 1);
518 if (ifp1->int_state & IS_REMOTE) {
521 if (check_remote(aifp)) {
522 aifp->int_act_time = now.tv_sec;
523 (void)if_ok(aifp, "remote ");
526 trace_pkt(" discard our own RIP response");
531 /* Accept routing packets from routers directly connected
532 * via broadcast or point-to-point networks, and from
533 * those listed in /etc/gateways.
536 msglim(&unk_router, FROM_NADDR,
537 " discard response from %s"
538 " via unexpected interface",
539 naddr_ntoa(FROM_NADDR));
542 if (IS_RIP_IN_OFF(aifp->int_state)) {
543 trace_pkt(" discard RIPv%d response"
544 " via disabled interface %s",
545 rip->rip_vers, aifp->int_name);
550 msglim(&bad_len, FROM_NADDR, "empty response from %s",
551 naddr_ntoa(FROM_NADDR));
555 if (((aifp->int_state & IS_NO_RIPV1_IN)
556 && rip->rip_vers == RIPv1)
557 || ((aifp->int_state & IS_NO_RIPV2_IN)
558 && rip->rip_vers != RIPv1)) {
559 trace_pkt(" discard RIPv%d response",
564 /* Ignore routes via dead interface.
566 if (aifp->int_state & IS_BROKE) {
567 trace_pkt("discard response via broken interface %s",
572 /* If the interface cares, ignore bad routers.
573 * Trace but do not log this problem, because where it
574 * happens, it happens frequently.
576 if (aifp->int_state & IS_DISTRUST) {
578 while (tg->tgate_addr != FROM_NADDR) {
581 trace_pkt(" discard RIP response"
582 " from untrusted router %s",
583 naddr_ntoa(FROM_NADDR));
589 /* Authenticate the packet if we have a secret.
590 * If we do not have any secrets, ignore the error in
591 * RFC 1723 and accept it regardless.
593 if (aifp->int_auth[0].type != RIP_AUTH_NONE
594 && rip->rip_vers != RIPv1
595 && !ck_passwd(aifp,rip,lim,FROM_NADDR,&use_auth))
599 if (n->n_family == RIP_AF_AUTH)
602 n->n_metric = ntohl(n->n_metric);
604 if (n->n_family != RIP_AF_INET
605 && (n->n_family != RIP_AF_UNSPEC
606 || dst != RIP_DEFAULT)) {
607 msglim(&bad_router, FROM_NADDR,
608 "route from %s to unsupported"
609 " address family=%d destination=%s",
610 naddr_ntoa(FROM_NADDR),
615 if (!check_dst(dst)) {
616 msglim(&bad_router, FROM_NADDR,
617 "bad destination %s from %s",
619 naddr_ntoa(FROM_NADDR));
623 || n->n_metric > HOPCNT_INFINITY) {
624 msglim(&bad_router, FROM_NADDR,
625 "bad metric %d from %s"
626 " for destination %s",
628 naddr_ntoa(FROM_NADDR),
633 /* Notice the next-hop.
636 if (n->n_nhop != 0) {
637 if (rip->rip_vers == RIPv1) {
640 /* Use it only if it is valid. */
641 if (on_net(n->n_nhop,
642 aifp->int_net, aifp->int_mask)
643 && check_dst(n->n_nhop)) {
646 msglim(&bad_nhop, FROM_NADDR,
648 " has bad next hop %s",
649 naddr_ntoa(FROM_NADDR),
651 naddr_ntoa(n->n_nhop));
657 if (rip->rip_vers == RIPv1
658 || 0 == (mask = ntohl(n->n_mask))) {
659 mask = ripv1_mask_host(dst,aifp);
660 } else if ((ntohl(dst) & ~mask) != 0) {
661 msglim(&bad_mask, FROM_NADDR,
662 "router %s sent bad netmask"
664 naddr_ntoa(FROM_NADDR),
669 if (rip->rip_vers == RIPv1)
672 /* Adjust metric according to incoming interface..
674 n->n_metric += (aifp->int_metric
675 + aifp->int_adj_inmetric);
676 if (n->n_metric > HOPCNT_INFINITY)
677 n->n_metric = HOPCNT_INFINITY;
679 /* Should we trust this route from this router? */
680 if (tg && (tn = tg->tgate_nets)->mask != 0) {
681 for (i = 0; i < MAX_TGATE_NETS; i++, tn++) {
682 if (on_net(dst, tn->net, tn->mask)
686 if (i >= MAX_TGATE_NETS || tn->mask == 0) {
687 trace_pkt(" ignored unauthorized %s",
688 addrname(dst,mask,0));
693 /* Recognize and ignore a default route we faked
694 * which is being sent back to us by a machine with
695 * broken split-horizon.
696 * Be a little more paranoid than that, and reject
697 * default routes with the same metric we advertised.
699 if (aifp->int_d_metric != 0
700 && dst == RIP_DEFAULT
701 && (int)n->n_metric >= aifp->int_d_metric)
704 /* We can receive aggregated RIPv2 routes that must
705 * be broken down before they are transmitted by
706 * RIPv1 via an interface on a subnet.
707 * We might also receive the same routes aggregated
708 * via other RIPv2 interfaces.
709 * This could cause duplicate routes to be sent on
710 * the RIPv1 interfaces. "Longest matching variable
711 * length netmasks" lets RIPv2 listeners understand,
712 * but breaking down the aggregated routes for RIPv1
713 * listeners can produce duplicate routes.
715 * Breaking down aggregated routes here bloats
716 * the daemon table, but does not hurt the kernel
717 * table, since routes are always aggregated for
720 * Notice that this does not break down network
721 * routes corresponding to subnets. This is part
722 * of the defense against RS_NET_SYN.
725 && (((rt = rtget(dst,mask)) == 0
726 || !(rt->rt_state & RS_NET_SYN)))
727 && (v1_mask = ripv1_mask_net(dst,0)) > mask) {
728 ddst_h = v1_mask & -v1_mask;
729 i = (v1_mask & ~mask)/ddst_h;
731 /* Punt if we would have to generate
732 * an unreasonable number of routes.
735 trace_misc("accept %s-->%s as 1"
736 " instead of %d routes",
737 addrname(dst,mask,0),
738 naddr_ntoa(FROM_NADDR),
749 new.rts_router = FROM_NADDR;
750 new.rts_metric = n->n_metric;
751 new.rts_tag = n->n_tag;
752 new.rts_time = now.tv_sec;
757 input_route(dst, mask, &new, n);
760 dst = htonl(ntohl(dst) + ddst_h);
769 /* Process a single input route.
772 input_route(naddr dst, /* network order */
774 struct rt_spare *new,
779 struct rt_spare *rts, *rts0;
780 struct interface *ifp1;
783 /* See if the other guy is telling us to send our packets to him.
784 * Sometimes network routes arrive over a point-to-point link for
785 * the network containing the address(es) of the link.
787 * If our interface is broken, switch to using the other guy.
789 ifp1 = ifwithaddr(dst, 1, 1);
791 && (!(ifp1->int_state & IS_BROKE)
792 || (ifp1->int_state & IS_PASSIVE)))
795 /* Look for the route in our table.
797 rt = rtget(dst, mask);
799 /* Consider adding the route if we do not already have it.
802 /* Ignore unknown routes being poisoned.
804 if (new->rts_metric == HOPCNT_INFINITY)
807 /* Ignore the route if it points to us */
809 && 0 != ifwithaddr(n->n_nhop, 1, 0))
812 /* If something has not gone crazy and tried to fill
813 * our memory, accept the new route.
815 if (total_routes < MAX_ROUTES)
816 rtadd(dst, mask, 0, new);
820 /* We already know about the route. Consider this update.
822 * If (rt->rt_state & RS_NET_SYN), then this route
823 * is the same as a network route we have inferred
824 * for subnets we know, in order to tell RIPv1 routers
827 * It is impossible to tell if the route is coming
828 * from a distant RIPv2 router with the standard
829 * netmask because that router knows about the entire
830 * network, or if it is a round-about echo of a
831 * synthetic, RIPv1 network route of our own.
832 * The worst is that both kinds of routes might be
833 * received, and the bad one might have the smaller
834 * metric. Partly solve this problem by never
835 * aggregating into such a route. Also keep it
836 * around as long as the interface exists.
839 rts0 = rt->rt_spares;
840 for (rts = rts0, i = NUM_SPARES; i != 0; i--, rts++) {
841 if (rts->rts_router == new->rts_router)
843 /* Note the worst slot to reuse,
844 * other than the current slot.
846 if (rts0 == rt->rt_spares
847 || BETTER_LINK(rt, rts0, rts))
851 /* Found a route from the router already in the table.
854 /* If the new route is a route broken down from an
855 * aggregated route, and if the previous route is either
856 * not a broken down route or was broken down from a finer
857 * netmask, and if the previous route is current,
858 * then forget this one.
860 if (new->rts_de_ag > rts->rts_de_ag
861 && now_stale <= rts->rts_time)
864 /* Keep poisoned routes around only long enough to pass
865 * the poison on. Use a new timestamp for good routes.
867 if (rts->rts_metric == HOPCNT_INFINITY
868 && new->rts_metric == HOPCNT_INFINITY)
869 new->rts_time = rts->rts_time;
871 /* If this is an update for the router we currently prefer,
874 if (i == NUM_SPARES) {
875 rtchange(rt, rt->rt_state, new, 0);
876 /* If the route got worse, check for something better.
878 if (new->rts_metric > rts->rts_metric)
883 /* This is an update for a spare route.
884 * Finished if the route is unchanged.
886 if (rts->rts_gate == new->rts_gate
887 && rts->rts_metric == new->rts_metric
888 && rts->rts_tag == new->rts_tag) {
889 trace_upslot(rt, rts, new);
893 /* Forget it if it has gone bad.
895 if (new->rts_metric == HOPCNT_INFINITY) {
901 /* The update is for a route we know about,
902 * but not from a familiar router.
904 * Ignore the route if it points to us.
907 && 0 != ifwithaddr(n->n_nhop, 1, 0))
910 /* the loop above set rts0=worst spare */
913 /* Save the route as a spare only if it has
914 * a better metric than our worst spare.
915 * This also ignores poisoned routes (those
916 * received with metric HOPCNT_INFINITY).
918 if (new->rts_metric >= rts->rts_metric)
922 trace_upslot(rt, rts, new);
925 /* try to switch to a better route */
930 static int /* 0 if bad */
931 ck_passwd(struct interface *aifp,
935 struct msg_limit *use_authp)
937 # define NA (rip->rip_auths)
941 u_char hash[RIP_AUTH_PW_LEN];
944 assert(aifp != NULL);
945 if ((void *)NA >= lim || NA->a_family != RIP_AF_AUTH) {
946 msglim(use_authp, from, "missing password from %s",
951 /* accept any current (+/- 24 hours) password
953 for (ap = aifp->int_auth, i = 0; i < MAX_AUTH_KEYS; i++, ap++) {
954 if (ap->type != NA->a_type
955 || (u_long)ap->start > (u_long)clk.tv_sec+DAY
956 || (u_long)ap->end+DAY < (u_long)clk.tv_sec)
959 if (NA->a_type == RIP_AUTH_PW) {
960 if (!memcmp(NA->au.au_pw, ap->key, RIP_AUTH_PW_LEN))
964 /* accept MD5 secret with the right key ID
966 if (NA->au.a_md5.md5_keyid != ap->keyid)
969 len = ntohs(NA->au.a_md5.md5_pkt_len);
970 if ((len-sizeof(*rip)) % sizeof(*NA) != 0
971 || len != (char *)lim-(char*)rip-(int)sizeof(*NA)) {
972 msglim(use_authp, from,
973 "wrong MD5 RIPv2 packet length of %d"
974 " instead of %d from %s",
975 len, (int)((char *)lim-(char *)rip
980 na2 = (struct netauth *)((char *)rip+len);
982 /* Given a good hash value, these are not security
983 * problems so be generous and accept the routes,
987 if (NA->au.a_md5.md5_auth_len
988 != RIP_AUTH_MD5_HASH_LEN)
989 msglim(use_authp, from,
990 "unknown MD5 RIPv2 auth len %#x"
991 " instead of %#x from %s",
992 NA->au.a_md5.md5_auth_len,
993 (unsigned)RIP_AUTH_MD5_HASH_LEN,
995 if (na2->a_family != RIP_AF_AUTH)
996 msglim(use_authp, from,
997 "unknown MD5 RIPv2 family %#x"
998 " instead of %#x from %s",
999 na2->a_family, RIP_AF_AUTH,
1001 if (na2->a_type != ntohs(1))
1002 msglim(use_authp, from,
1003 "MD5 RIPv2 hash has %#x"
1004 " instead of %#x from %s",
1005 na2->a_type, ntohs(1),
1010 MD5Update(&md5_ctx, (u_char *)rip,
1011 len + RIP_AUTH_MD5_HASH_XTRA);
1012 MD5Update(&md5_ctx, ap->key, RIP_AUTH_MD5_KEY_LEN);
1013 MD5Final(hash, &md5_ctx);
1014 if (!memcmp(hash, na2->au.au_pw, sizeof(hash)))
1019 msglim(use_authp, from, "bad password from %s",