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)) {
292 supply(from, aifp, OUT_QUERY, 0,
293 rip->rip_vers, ap != 0);
297 /* A router trying to prime its tables.
298 * Filter the answer in the about same way
299 * broadcasts are filtered.
301 * Only answer a router if we are a supplier
302 * to keep an unwary host that is just starting
303 * from picking us as a router.
306 trace_pkt("ignore distant router");
310 || IS_RIP_OFF(aifp->int_state)) {
311 trace_pkt("ignore; not supplying");
315 /* Do not answer a RIPv1 router if
316 * we are sending RIPv2. But do offer
317 * poor man's router discovery.
319 if ((aifp->int_state & IS_NO_RIPV1_OUT)
320 && rip->rip_vers == RIPv1) {
321 if (!(aifp->int_state & IS_PM_RDISC)) {
322 trace_pkt("ignore; sending RIPv2");
326 v12buf.n->n_family = RIP_AF_INET;
327 v12buf.n->n_dst = RIP_DEFAULT;
328 i = aifp->int_d_metric;
329 if (0 != (rt = rtget(RIP_DEFAULT, 0))) {
332 +aifp->int_adj_outmetric
337 v12buf.n->n_metric = htonl(i);
342 /* Respond with RIPv1 instead of RIPv2 if
343 * that is what we are broadcasting on the
344 * interface to keep the remote router from
345 * getting the wrong initial idea of the
348 supply(from, aifp, OUT_UNICAST, 0,
349 (aifp->int_state & IS_NO_RIPV1_OUT)
355 /* Ignore authentication */
356 if (n->n_family == RIP_AF_AUTH)
359 if (n->n_family != RIP_AF_INET) {
360 msglim(&bad_router, FROM_NADDR,
361 "request from %s for unsupported"
363 naddr_ntoa(FROM_NADDR),
365 naddr_ntoa(n->n_dst));
369 /* We are being asked about a specific destination.
372 if (!check_dst(dst)) {
373 msglim(&bad_router, FROM_NADDR,
374 "bad queried destination %s from %s",
376 naddr_ntoa(FROM_NADDR));
380 /* decide what mask was intended */
381 if (rip->rip_vers == RIPv1
382 || 0 == (mask = ntohl(n->n_mask))
383 || 0 != (ntohl(dst) & ~mask))
384 mask = ripv1_mask_host(dst, aifp);
386 /* try to find the answer */
387 rt = rtget(dst, mask);
388 if (!rt && dst != RIP_DEFAULT)
389 rt = rtfind(n->n_dst);
391 if (v12buf.buf->rip_vers != RIPv1)
392 v12buf.n->n_mask = mask;
394 /* we do not have the answer */
395 v12buf.n->n_metric = HOPCNT_INFINITY;
397 /* we have the answer, so compute the
398 * right metric and next hop.
400 v12buf.n->n_family = RIP_AF_INET;
401 v12buf.n->n_dst = dst;
406 j += (aifp->int_metric
407 + aifp->int_adj_outmetric);
408 if (j < HOPCNT_INFINITY)
409 v12buf.n->n_metric = j;
411 v12buf.n->n_metric = HOPCNT_INFINITY;
412 if (v12buf.buf->rip_vers != RIPv1) {
413 v12buf.n->n_tag = rt->rt_tag;
414 v12buf.n->n_mask = mask;
416 && on_net(rt->rt_gate,
419 && rt->rt_gate != aifp->int_addr)
420 v12buf.n->n_nhop = rt->rt_gate;
423 v12buf.n->n_metric = htonl(v12buf.n->n_metric);
425 /* Stop paying attention if we fill the output buffer.
427 if (++v12buf.n >= v12buf.lim)
431 /* Send the answer about specific routes.
433 if (ap != 0 && ap->type == RIP_AUTH_MD5)
434 end_md5_auth(&v12buf, ap);
436 if (from->sin_port != htons(RIP_PORT)) {
438 (void)output(OUT_QUERY, from, aifp,
440 ((char *)v12buf.n - (char*)v12buf.buf));
441 } else if (supplier) {
442 (void)output(OUT_UNICAST, from, aifp,
444 ((char *)v12buf.n - (char*)v12buf.buf));
446 /* Only answer a router if we are a supplier
447 * to keep an unwary host that is just starting
448 * from picking us an a router.
455 case RIPCMD_TRACEOFF:
456 /* Notice that trace messages are turned off for all possible
457 * abuse if _PATH_TRACE is undefined in pathnames.h.
458 * Notice also that because of the way the trace file is
459 * handled in trace.c, no abuse is plausible even if
460 * _PATH_TRACE_ is defined.
462 * First verify message came from a privileged port. */
463 if (ntohs(from->sin_port) > IPPORT_RESERVED) {
464 msglog("trace command from untrusted port on %s",
465 naddr_ntoa(FROM_NADDR));
469 msglog("trace command from unknown router %s",
470 naddr_ntoa(FROM_NADDR));
473 if (rip->rip_cmd == RIPCMD_TRACEON) {
474 rip->rip_tracefile[cc-4] = '\0';
475 set_tracefile((char*)rip->rip_tracefile,
476 "trace command: %s\n", 0);
478 trace_off("tracing turned off by %s",
479 naddr_ntoa(FROM_NADDR));
483 case RIPCMD_RESPONSE:
484 if (cc%sizeof(*n) != sizeof(struct rip)%sizeof(*n)) {
485 msglim(&bad_len, FROM_NADDR,
486 "response of bad length (%d) from %s",
487 cc, naddr_ntoa(FROM_NADDR));
490 /* verify message came from a router */
491 if (from->sin_port != ntohs(RIP_PORT)) {
492 msglim(&bad_router, FROM_NADDR,
493 " discard RIP response from unknown port"
495 ntohs(from->sin_port), naddr_ntoa(FROM_NADDR));
500 trace_pkt(" discard response while RIP off");
504 /* Are we talking to ourself or a remote gateway?
506 ifp1 = ifwithaddr(FROM_NADDR, 0, 1);
508 if (ifp1->int_state & IS_REMOTE) {
511 if (check_remote(aifp)) {
512 aifp->int_act_time = now.tv_sec;
513 (void)if_ok(aifp, "remote ");
516 trace_pkt(" discard our own RIP response");
521 /* Accept routing packets from routers directly connected
522 * via broadcast or point-to-point networks, and from
523 * those listed in /etc/gateways.
526 msglim(&unk_router, FROM_NADDR,
527 " discard response from %s"
528 " via unexpected interface",
529 naddr_ntoa(FROM_NADDR));
532 if (IS_RIP_IN_OFF(aifp->int_state)) {
533 trace_pkt(" discard RIPv%d response"
534 " via disabled interface %s",
535 rip->rip_vers, aifp->int_name);
540 msglim(&bad_len, FROM_NADDR, "empty response from %s",
541 naddr_ntoa(FROM_NADDR));
545 if (((aifp->int_state & IS_NO_RIPV1_IN)
546 && rip->rip_vers == RIPv1)
547 || ((aifp->int_state & IS_NO_RIPV2_IN)
548 && rip->rip_vers != RIPv1)) {
549 trace_pkt(" discard RIPv%d response",
554 /* Ignore routes via dead interface.
556 if (aifp->int_state & IS_BROKE) {
557 trace_pkt("discard response via broken interface %s",
562 /* If the interface cares, ignore bad routers.
563 * Trace but do not log this problem, because where it
564 * happens, it happens frequently.
566 if (aifp->int_state & IS_DISTRUST) {
568 while (tg->tgate_addr != FROM_NADDR) {
571 trace_pkt(" discard RIP response"
572 " from untrusted router %s",
573 naddr_ntoa(FROM_NADDR));
579 /* Authenticate the packet if we have a secret.
580 * If we do not have any secrets, ignore the error in
581 * RFC 1723 and accept it regardless.
583 if (aifp->int_auth[0].type != RIP_AUTH_NONE
584 && rip->rip_vers != RIPv1
585 && !ck_passwd(aifp,rip,lim,FROM_NADDR,&use_auth))
589 if (n->n_family == RIP_AF_AUTH)
592 n->n_metric = ntohl(n->n_metric);
594 if (n->n_family != RIP_AF_INET
595 && (n->n_family != RIP_AF_UNSPEC
596 || dst != RIP_DEFAULT)) {
597 msglim(&bad_router, FROM_NADDR,
598 "route from %s to unsupported"
599 " address family=%d destination=%s",
600 naddr_ntoa(FROM_NADDR),
605 if (!check_dst(dst)) {
606 msglim(&bad_router, FROM_NADDR,
607 "bad destination %s from %s",
609 naddr_ntoa(FROM_NADDR));
613 || n->n_metric > HOPCNT_INFINITY) {
614 msglim(&bad_router, FROM_NADDR,
615 "bad metric %d from %s"
616 " for destination %s",
618 naddr_ntoa(FROM_NADDR),
623 /* Notice the next-hop.
626 if (n->n_nhop != 0) {
627 if (rip->rip_vers == RIPv1) {
630 /* Use it only if it is valid. */
631 if (on_net(n->n_nhop,
632 aifp->int_net, aifp->int_mask)
633 && check_dst(n->n_nhop)) {
636 msglim(&bad_nhop, FROM_NADDR,
638 " has bad next hop %s",
639 naddr_ntoa(FROM_NADDR),
641 naddr_ntoa(n->n_nhop));
647 if (rip->rip_vers == RIPv1
648 || 0 == (mask = ntohl(n->n_mask))) {
649 mask = ripv1_mask_host(dst,aifp);
650 } else if ((ntohl(dst) & ~mask) != 0) {
651 msglim(&bad_mask, FROM_NADDR,
652 "router %s sent bad netmask"
654 naddr_ntoa(FROM_NADDR),
659 if (rip->rip_vers == RIPv1)
662 /* Adjust metric according to incoming interface..
664 n->n_metric += (aifp->int_metric
665 + aifp->int_adj_inmetric);
666 if (n->n_metric > HOPCNT_INFINITY)
667 n->n_metric = HOPCNT_INFINITY;
669 /* Should we trust this route from this router? */
670 if (tg && (tn = tg->tgate_nets)->mask != 0) {
671 for (i = 0; i < MAX_TGATE_NETS; i++, tn++) {
672 if (on_net(dst, tn->net, tn->mask)
676 if (i >= MAX_TGATE_NETS || tn->mask == 0) {
677 trace_pkt(" ignored unauthorized %s",
678 addrname(dst,mask,0));
683 /* Recognize and ignore a default route we faked
684 * which is being sent back to us by a machine with
685 * broken split-horizon.
686 * Be a little more paranoid than that, and reject
687 * default routes with the same metric we advertised.
689 if (aifp->int_d_metric != 0
690 && dst == RIP_DEFAULT
691 && (int)n->n_metric >= aifp->int_d_metric)
694 /* We can receive aggregated RIPv2 routes that must
695 * be broken down before they are transmitted by
696 * RIPv1 via an interface on a subnet.
697 * We might also receive the same routes aggregated
698 * via other RIPv2 interfaces.
699 * This could cause duplicate routes to be sent on
700 * the RIPv1 interfaces. "Longest matching variable
701 * length netmasks" lets RIPv2 listeners understand,
702 * but breaking down the aggregated routes for RIPv1
703 * listeners can produce duplicate routes.
705 * Breaking down aggregated routes here bloats
706 * the daemon table, but does not hurt the kernel
707 * table, since routes are always aggregated for
710 * Notice that this does not break down network
711 * routes corresponding to subnets. This is part
712 * of the defense against RS_NET_SYN.
715 && (((rt = rtget(dst,mask)) == 0
716 || !(rt->rt_state & RS_NET_SYN)))
717 && (v1_mask = ripv1_mask_net(dst,0)) > mask) {
718 ddst_h = v1_mask & -v1_mask;
719 i = (v1_mask & ~mask)/ddst_h;
721 /* Punt if we would have to generate
722 * an unreasonable number of routes.
725 trace_misc("accept %s-->%s as 1"
726 " instead of %d routes",
727 addrname(dst,mask,0),
728 naddr_ntoa(FROM_NADDR),
739 new.rts_router = FROM_NADDR;
740 new.rts_metric = n->n_metric;
741 new.rts_tag = n->n_tag;
742 new.rts_time = now.tv_sec;
747 input_route(dst, mask, &new, n);
750 dst = htonl(ntohl(dst) + ddst_h);
759 /* Process a single input route.
762 input_route(naddr dst, /* network order */
764 struct rt_spare *new,
769 struct rt_spare *rts, *rts0;
770 struct interface *ifp1;
773 /* See if the other guy is telling us to send our packets to him.
774 * Sometimes network routes arrive over a point-to-point link for
775 * the network containing the address(es) of the link.
777 * If our interface is broken, switch to using the other guy.
779 ifp1 = ifwithaddr(dst, 1, 1);
781 && (!(ifp1->int_state & IS_BROKE)
782 || (ifp1->int_state & IS_PASSIVE)))
785 /* Look for the route in our table.
787 rt = rtget(dst, mask);
789 /* Consider adding the route if we do not already have it.
792 /* Ignore unknown routes being poisoned.
794 if (new->rts_metric == HOPCNT_INFINITY)
797 /* Ignore the route if it points to us */
799 && 0 != ifwithaddr(n->n_nhop, 1, 0))
802 /* If something has not gone crazy and tried to fill
803 * our memory, accept the new route.
805 if (total_routes < MAX_ROUTES)
806 rtadd(dst, mask, 0, new);
810 /* We already know about the route. Consider this update.
812 * If (rt->rt_state & RS_NET_SYN), then this route
813 * is the same as a network route we have inferred
814 * for subnets we know, in order to tell RIPv1 routers
817 * It is impossible to tell if the route is coming
818 * from a distant RIPv2 router with the standard
819 * netmask because that router knows about the entire
820 * network, or if it is a round-about echo of a
821 * synthetic, RIPv1 network route of our own.
822 * The worst is that both kinds of routes might be
823 * received, and the bad one might have the smaller
824 * metric. Partly solve this problem by never
825 * aggregating into such a route. Also keep it
826 * around as long as the interface exists.
829 rts0 = rt->rt_spares;
830 for (rts = rts0, i = NUM_SPARES; i != 0; i--, rts++) {
831 if (rts->rts_router == new->rts_router)
833 /* Note the worst slot to reuse,
834 * other than the current slot.
836 if (rts0 == rt->rt_spares
837 || BETTER_LINK(rt, rts0, rts))
841 /* Found a route from the router already in the table.
844 /* If the new route is a route broken down from an
845 * aggregated route, and if the previous route is either
846 * not a broken down route or was broken down from a finer
847 * netmask, and if the previous route is current,
848 * then forget this one.
850 if (new->rts_de_ag > rts->rts_de_ag
851 && now_stale <= rts->rts_time)
854 /* Keep poisoned routes around only long enough to pass
855 * the poison on. Use a new timestamp for good routes.
857 if (rts->rts_metric == HOPCNT_INFINITY
858 && new->rts_metric == HOPCNT_INFINITY)
859 new->rts_time = rts->rts_time;
861 /* If this is an update for the router we currently prefer,
864 if (i == NUM_SPARES) {
865 rtchange(rt, rt->rt_state, new, 0);
866 /* If the route got worse, check for something better.
868 if (new->rts_metric > rts->rts_metric)
873 /* This is an update for a spare route.
874 * Finished if the route is unchanged.
876 if (rts->rts_gate == new->rts_gate
877 && rts->rts_metric == new->rts_metric
878 && rts->rts_tag == new->rts_tag) {
879 trace_upslot(rt, rts, new);
883 /* Forget it if it has gone bad.
885 if (new->rts_metric == HOPCNT_INFINITY) {
891 /* The update is for a route we know about,
892 * but not from a familiar router.
894 * Ignore the route if it points to us.
897 && 0 != ifwithaddr(n->n_nhop, 1, 0))
900 /* the loop above set rts0=worst spare */
903 /* Save the route as a spare only if it has
904 * a better metric than our worst spare.
905 * This also ignores poisoned routes (those
906 * received with metric HOPCNT_INFINITY).
908 if (new->rts_metric >= rts->rts_metric)
912 trace_upslot(rt, rts, new);
915 /* try to switch to a better route */
920 static int /* 0 if bad */
921 ck_passwd(struct interface *aifp,
925 struct msg_limit *use_authp)
927 # define NA (rip->rip_auths)
931 u_char hash[RIP_AUTH_PW_LEN];
934 assert(aifp != NULL);
935 if ((void *)NA >= lim || NA->a_family != RIP_AF_AUTH) {
936 msglim(use_authp, from, "missing password from %s",
941 /* accept any current (+/- 24 hours) password
943 for (ap = aifp->int_auth, i = 0; i < MAX_AUTH_KEYS; i++, ap++) {
944 if (ap->type != NA->a_type
945 || (u_long)ap->start > (u_long)clk.tv_sec+DAY
946 || (u_long)ap->end+DAY < (u_long)clk.tv_sec)
949 if (NA->a_type == RIP_AUTH_PW) {
950 if (!memcmp(NA->au.au_pw, ap->key, RIP_AUTH_PW_LEN))
954 /* accept MD5 secret with the right key ID
956 if (NA->au.a_md5.md5_keyid != ap->keyid)
959 len = ntohs(NA->au.a_md5.md5_pkt_len);
960 if ((len-sizeof(*rip)) % sizeof(*NA) != 0
961 || len != (char *)lim-(char*)rip-(int)sizeof(*NA)) {
962 msglim(use_authp, from,
963 "wrong MD5 RIPv2 packet length of %d"
964 " instead of %d from %s",
965 len, (int)((char *)lim-(char *)rip
970 na2 = (struct netauth *)((char *)rip+len);
972 /* Given a good hash value, these are not security
973 * problems so be generous and accept the routes,
977 if (NA->au.a_md5.md5_auth_len
978 != RIP_AUTH_MD5_HASH_LEN)
979 msglim(use_authp, from,
980 "unknown MD5 RIPv2 auth len %#x"
981 " instead of %#x from %s",
982 NA->au.a_md5.md5_auth_len,
983 (unsigned)RIP_AUTH_MD5_HASH_LEN,
985 if (na2->a_family != RIP_AF_AUTH)
986 msglim(use_authp, from,
987 "unknown MD5 RIPv2 family %#x"
988 " instead of %#x from %s",
989 na2->a_family, RIP_AF_AUTH,
991 if (na2->a_type != ntohs(1))
992 msglim(use_authp, from,
993 "MD5 RIPv2 hash has %#x"
994 " instead of %#x from %s",
995 na2->a_type, ntohs(1),
1000 MD5Update(&md5_ctx, (u_char *)rip,
1001 len + RIP_AUTH_MD5_HASH_XTRA);
1002 MD5Update(&md5_ctx, ap->key, RIP_AUTH_MD5_KEY_LEN);
1003 MD5Final(hash, &md5_ctx);
1004 if (!memcmp(hash, na2->au.au_pw, sizeof(hash)))
1009 msglim(use_authp, from, "bad password from %s",