1 /*
2 * Copyright 2007 Sun Microsystems, Inc. All rights reserved.
3 * Use is subject to license terms.
4 *
5 * Copyright (c) 1983, 1988, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgment:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * $FreeBSD: src/sbin/routed/output.c,v 1.7 2000/08/11 08:24:38 sheldonh Exp $
37 */
38
39 #pragma ident "%Z%%M% %I% %E% SMI"
40
41 #include "defs.h"
42 #include <md5.h>
43 #include <alloca.h>
44
45 uint_t update_seqno;
46
47
48 /*
49 * walk the tree of routes with this for output
50 */
51 static struct {
52 struct sockaddr_in to;
53 in_addr_t to_mask;
54 in_addr_t to_net;
55 in_addr_t to_std_mask;
56 in_addr_t to_std_net;
57 struct interface *ifp; /* usually output interface */
58 struct auth *a;
59 uint8_t metric; /* adjust metrics by interface */
60 uint32_t npackets;
61 uint32_t gen_limit;
62 #define WS_GEN_LIMIT_MAX 1024
63 uint16_t state;
64 #define WS_ST_FLASH 0x001 /* send only changed routes */
65 #define WS_ST_RIP2_ALL 0x002 /* send full featured RIPv2 */
66 #define WS_ST_AG 0x004 /* ok to aggregate subnets */
67 #define WS_ST_SUPER_AG 0x008 /* ok to aggregate networks */
68 #define WS_ST_QUERY 0x010 /* responding to a query */
69 #define WS_ST_TO_ON_NET 0x020 /* sending onto one of our nets */
70 #define WS_ST_DEFAULT 0x040 /* faking a default */
71 } ws;
72
73 /* A buffer for what can be heard by both RIPv1 and RIPv2 listeners */
74 struct ws_buf v12buf;
75 static union pkt_buf ripv12_buf;
76
77 /* Another for only RIPv2 listeners */
78 static struct ws_buf v2buf;
79 static union pkt_buf rip_v2_buf;
80
81
82
83 void
bufinit(void)84 bufinit(void)
85 {
86 ripv12_buf.rip.rip_cmd = RIPCMD_RESPONSE;
87 v12buf.buf = &ripv12_buf.rip;
88 v12buf.base = &v12buf.buf->rip_nets[0];
89
90 rip_v2_buf.rip.rip_cmd = RIPCMD_RESPONSE;
91 rip_v2_buf.rip.rip_vers = RIPv2;
92 v2buf.buf = &rip_v2_buf.rip;
93 v2buf.base = &v2buf.buf->rip_nets[0];
94 }
95
96
97 /*
98 * Send the contents of the global buffer via the non-multicast socket
99 */
100 int /* <0 on failure */
output(enum output_type type,struct sockaddr_in * dst,struct interface * ifp,struct rip * buf,int size)101 output(enum output_type type,
102 struct sockaddr_in *dst, /* send to here */
103 struct interface *ifp,
104 struct rip *buf,
105 int size) /* this many bytes */
106 {
107 struct sockaddr_in sin;
108 int flags;
109 const char *msg;
110 int res;
111 int ifindex;
112 struct in_addr addr;
113
114 sin = *dst;
115 if (sin.sin_port == 0)
116 sin.sin_port = htons(RIP_PORT);
117
118 flags = 0;
119
120 if (ifp == NULL && type == OUT_MULTICAST) {
121 msglog("Cannot send RIP message to %s",
122 inet_ntoa(sin.sin_addr));
123 return (-1);
124 }
125
126 switch (type) {
127 case OUT_QUERY:
128 msg = "Answer Query";
129 break;
130 case OUT_UNICAST:
131 msg = "Send";
132 flags = MSG_DONTROUTE;
133 break;
134 case OUT_BROADCAST:
135 msg = "Send bcast";
136 break;
137 case OUT_MULTICAST:
138 msg = "Send mcast";
139 break;
140
141 case NO_OUT_MULTICAST:
142 case NO_OUT_RIPV2:
143 default:
144 #ifdef DEBUG
145 abort();
146 #endif
147 return (-1);
148 }
149
150 /*
151 * IP_PKTINFO overrides IP_MULTICAST_IF, so we don't set ifindex
152 * for multicast traffic.
153 */
154 ifindex = (type != OUT_MULTICAST && type != OUT_QUERY &&
155 ifp != NULL && ifp->int_phys != NULL) ?
156 ifp->int_phys->phyi_index : 0;
157
158 if (rip_sock_interface != ifp) {
159 /*
160 * For multicast, we have to choose the source
161 * address. This is either the local address
162 * (non-point-to-point) or the remote address.
163 */
164 if (ifp != NULL) {
165 addr.s_addr = (ifp->int_if_flags & IFF_POINTOPOINT) ?
166 ifp->int_dstaddr : ifp->int_addr;
167 if (type == OUT_MULTICAST &&
168 setsockopt(rip_sock, IPPROTO_IP,
169 IP_MULTICAST_IF, &addr, sizeof (addr)) == -1) {
170 LOGERR("setsockopt(rip_sock, IP_MULTICAST_IF)");
171 return (-1);
172 }
173 }
174 rip_sock_interface = ifp;
175 }
176
177 trace_rip(msg, "to", &sin, ifp, buf, size);
178
179 res = sendtoif(rip_sock, buf, size, flags, &sin, ifindex);
180 if (res < 0 && (ifp == NULL || !(ifp->int_state & IS_BROKE))) {
181 writelog(LOG_WARNING, "%s sendto(%s%s%s.%d): %s", msg,
182 ifp != NULL ? ifp->int_name : "",
183 ifp != NULL ? ", " : "",
184 inet_ntoa(sin.sin_addr),
185 ntohs(sin.sin_port),
186 rip_strerror(errno));
187 }
188
189 return (res);
190 }
191
192 /*
193 * Semantically identical to sendto(), but sends the message through a
194 * specific interface (if ifindex is non-zero) using IP_PKTINFO.
195 */
196 int
sendtoif(int fd,const void * buf,uint_t bufsize,uint_t flags,struct sockaddr_in * sinp,uint_t ifindex)197 sendtoif(int fd, const void *buf, uint_t bufsize, uint_t flags,
198 struct sockaddr_in *sinp, uint_t ifindex)
199 {
200 struct iovec iov;
201 struct msghdr msg;
202 struct cmsghdr *cmsgp;
203 struct in_pktinfo *ipip;
204
205 iov.iov_base = (void *)buf;
206 iov.iov_len = bufsize;
207
208 (void) memset(&msg, 0, sizeof (struct msghdr));
209 msg.msg_name = (struct sockaddr *)sinp;
210 msg.msg_namelen = sizeof (struct sockaddr_in);
211 msg.msg_iov = &iov;
212 msg.msg_iovlen = 1;
213
214 if (ifindex != 0) {
215 /*
216 * We can't precisely predict the alignment padding we'll
217 * need, so we allocate the maximum alignment and then
218 * use CMSG_NXTHDR() to fix it up at the end.
219 */
220 msg.msg_controllen = sizeof (*cmsgp) + _MAX_ALIGNMENT +
221 sizeof (*ipip) + _MAX_ALIGNMENT + sizeof (*cmsgp);
222 msg.msg_control = alloca(msg.msg_controllen);
223
224 cmsgp = CMSG_FIRSTHDR(&msg);
225 ipip = (void *)CMSG_DATA(cmsgp);
226 (void) memset(ipip, 0, sizeof (struct in_pktinfo));
227 ipip->ipi_ifindex = ifindex;
228 cmsgp->cmsg_len = (caddr_t)(ipip + 1) - (caddr_t)cmsgp;
229 cmsgp->cmsg_type = IP_PKTINFO;
230 cmsgp->cmsg_level = IPPROTO_IP;
231
232 /*
233 * Correct the control message length.
234 */
235 cmsgp = CMSG_NXTHDR(&msg, cmsgp);
236 msg.msg_controllen = (caddr_t)cmsgp - (caddr_t)msg.msg_control;
237 }
238
239 return (sendmsg(fd, &msg, flags));
240 }
241
242 /*
243 * Find the first key for a packet to send.
244 * Try for a key that is eligible and has not expired, but settle for
245 * the last key if they have all expired.
246 * If no key is ready yet, give up.
247 */
248 struct auth *
find_auth(struct interface * ifp)249 find_auth(struct interface *ifp)
250 {
251 struct auth *ap, *res = NULL;
252 int i;
253
254
255 if (ifp == NULL)
256 return (NULL);
257
258 if ((ap = ifp->int_auth) == NULL)
259 return (NULL);
260
261 for (i = 0; i < MAX_AUTH_KEYS; i++, ap++) {
262 /* stop looking after the last key */
263 if (ap->type == RIP_AUTH_NONE)
264 break;
265
266 /* ignore keys that are not ready yet */
267 if ((ulong_t)ap->start > (ulong_t)clk.tv_sec)
268 continue;
269
270 if ((ulong_t)ap->end < (ulong_t)clk.tv_sec) {
271 /* note best expired password as a fall-back */
272 if (res == NULL ||
273 (((ulong_t)ap->end > (ulong_t)res->end)) &&
274 ((ulong_t)res->end < (ulong_t)clk.tv_sec))
275 res = ap;
276 continue;
277 }
278
279 /* note key with the best future */
280 if (res == NULL || (ulong_t)res->end < (ulong_t)ap->end)
281 res = ap;
282 }
283 return (res);
284 }
285
286
287 void
clr_ws_buf(struct ws_buf * wb,struct auth * ap)288 clr_ws_buf(struct ws_buf *wb, struct auth *ap)
289 {
290 struct netauth *na;
291
292 wb->lim = wb->base + NETS_LEN;
293 wb->n = wb->base;
294 (void) memset(wb->n, 0, NETS_LEN*sizeof (*wb->n));
295
296 /*
297 * (start to) install authentication if appropriate
298 */
299 if (ap == NULL)
300 return;
301
302 na = (struct netauth *)wb->n;
303 if (ap->type == RIP_AUTH_PW) {
304 na->a_family = RIP_AF_AUTH;
305 na->a_type = RIP_AUTH_PW;
306 (void) memcpy(na->au.au_pw, ap->key, sizeof (na->au.au_pw));
307 wb->n++;
308
309 } else if (ap->type == RIP_AUTH_MD5) {
310 na->a_family = RIP_AF_AUTH;
311 na->a_type = RIP_AUTH_MD5;
312 na->au.a_md5.md5_keyid = ap->keyid;
313 na->au.a_md5.md5_auth_len = RIP_AUTH_MD5_LEN;
314 na->au.a_md5.md5_seqno = htonl(clk.tv_sec);
315 wb->n++;
316 wb->lim--; /* make room for trailer */
317 }
318 }
319
320
321 void
end_md5_auth(struct ws_buf * wb,struct auth * ap)322 end_md5_auth(struct ws_buf *wb, struct auth *ap)
323 {
324 struct netauth *na, *na2;
325 MD5_CTX md5_ctx;
326 int len;
327
328 na = (struct netauth *)wb->base;
329 na2 = (struct netauth *)wb->n;
330 len = (char *)na2-(char *)wb->buf;
331 na2->a_family = RIP_AF_AUTH;
332 na2->a_type = RIP_AUTH_TRAILER;
333 na->au.a_md5.md5_pkt_len = htons(len);
334 MD5Init(&md5_ctx);
335 /* len+4 to include auth trailer's family/type in MD5 sum */
336 MD5Update(&md5_ctx, (uchar_t *)wb->buf, len + 4);
337 MD5Update(&md5_ctx, ap->key, RIP_AUTH_MD5_LEN);
338 MD5Final(na2->au.au_pw, &md5_ctx);
339 wb->n++;
340 }
341
342
343 /*
344 * Send the buffer
345 */
346 static void
supply_write(struct ws_buf * wb)347 supply_write(struct ws_buf *wb)
348 {
349 /*
350 * Output multicast only if legal.
351 * If we would multicast and it would be illegal, then discard the
352 * packet.
353 */
354 switch (wb->type) {
355 case NO_OUT_MULTICAST:
356 trace_pkt("skip multicast to %s because impossible",
357 naddr_ntoa(ws.to.sin_addr.s_addr));
358 break;
359 case NO_OUT_RIPV2:
360 break;
361 default:
362 if (ws.a != NULL && ws.a->type == RIP_AUTH_MD5)
363 end_md5_auth(wb, ws.a);
364 if (output(wb->type, &ws.to, ws.ifp, wb->buf,
365 ((char *)wb->n - (char *)wb->buf)) < 0 && ws.ifp != NULL)
366 if_sick(ws.ifp, _B_FALSE);
367 ws.npackets++;
368 break;
369 }
370
371 clr_ws_buf(wb, ws.a);
372 }
373
374
375 /*
376 * Put an entry into the packet
377 */
378 static void
supply_out(struct ag_info * ag)379 supply_out(struct ag_info *ag)
380 {
381 uint32_t dstcount;
382 in_addr_t mask, v1_mask, dst_h, ddst_h = 0;
383 struct ws_buf *wb;
384
385
386 /*
387 * Skip this route if doing a flash update and it and the routes
388 * it aggregates have not changed recently.
389 */
390 if (ag->ag_seqno < update_seqno && (ws.state & WS_ST_FLASH))
391 return;
392
393 dst_h = ag->ag_dst_h;
394 mask = ag->ag_mask;
395 v1_mask = ripv1_mask_host(htonl(dst_h),
396 (ws.state & WS_ST_TO_ON_NET) ? ws.ifp : NULL);
397 dstcount = 0;
398
399 /*
400 * If we are sending RIPv2 packets that cannot (or must not) be
401 * heard by RIPv1 listeners, do not worry about sub- or supernets.
402 * Subnets (from other networks) can only be sent via multicast.
403 * A pair of subnet routes might have been promoted so that they
404 * are legal to send by RIPv1.
405 * If RIPv1 is off, use the multicast buffer.
406 */
407 if ((ws.state & WS_ST_RIP2_ALL) ||
408 ((ag->ag_state & AGS_RIPV2) && v1_mask != mask)) {
409 /* use the RIPv2-only buffer */
410 wb = &v2buf;
411
412 } else {
413 /*
414 * use the RIPv1-or-RIPv2 buffer
415 */
416 wb = &v12buf;
417
418 /*
419 * Convert supernet route into corresponding set of network
420 * routes for RIPv1, but leave non-contiguous netmasks
421 * to ag_check().
422 */
423 if (v1_mask > mask &&
424 mask + (mask & -mask) == 0) {
425 ddst_h = v1_mask & -v1_mask;
426 dstcount = (v1_mask & ~mask)/ddst_h;
427
428 if (dstcount > ws.gen_limit) {
429 /*
430 * Punt if we would have to generate an
431 * unreasonable number of routes.
432 */
433 if (TRACECONTENTS)
434 trace_misc("sending %s-->%s as 1"
435 " instead of %d routes",
436 addrname(htonl(dst_h), mask, 1),
437 naddr_ntoa(ws.to.sin_addr.s_addr),
438 dstcount + 1);
439 dstcount = 0;
440
441 } else {
442 mask = v1_mask;
443 ws.gen_limit -= dstcount;
444 }
445 }
446 }
447
448 do {
449 wb->n->n_family = RIP_AF_INET;
450 wb->n->n_dst = htonl(dst_h);
451 /*
452 * If the route is from router-discovery or we are
453 * shutting down, or this is a broken/sick interface,
454 * admit only a bad metric.
455 */
456 wb->n->n_metric = ((stopint || ag->ag_metric < 1 ||
457 (ag->ag_ifp && (ag->ag_ifp->int_state &
458 (IS_BROKE|IS_SICK)))) ? HOPCNT_INFINITY : ag->ag_metric);
459 wb->n->n_metric = htonl(wb->n->n_metric);
460 /*
461 * Any non-zero bits in the supposedly unused RIPv1 fields
462 * cause the old `routed` to ignore the route.
463 * That means the mask and so forth cannot be sent
464 * in the hybrid RIPv1/RIPv2 mode.
465 */
466 if (ws.state & WS_ST_RIP2_ALL) {
467 if (ag->ag_nhop != 0 &&
468 ((ws.state & WS_ST_QUERY) ||
469 (ag->ag_nhop != ws.ifp->int_addr &&
470 on_net(ag->ag_nhop, ws.ifp->int_net,
471 ws.ifp->int_mask)) &&
472 ifwithaddr(ag->ag_nhop, _B_FALSE, _B_FALSE) ==
473 NULL))
474 wb->n->n_nhop = ag->ag_nhop;
475 wb->n->n_mask = htonl(mask);
476 wb->n->n_tag = ag->ag_tag;
477 }
478 dst_h += ddst_h;
479
480 if (++wb->n >= wb->lim)
481 supply_write(wb);
482 } while (dstcount-- > 0);
483 }
484
485
486 /*
487 * Supply one route from the table
488 */
489 /* ARGSUSED */
490 static int
walk_supply(struct radix_node * rn,void * argp)491 walk_supply(struct radix_node *rn, void *argp)
492 {
493 #define RT ((struct rt_entry *)rn)
494 ushort_t ags;
495 uint8_t metric, pref;
496 in_addr_t dst, nhop;
497 struct rt_spare *rts;
498 uint_t sparecount;
499
500
501 /*
502 * Do not advertise external remote interfaces or passive interfaces.
503 */
504 if ((RT->rt_state & RS_IF) && RT->rt_ifp != NULL &&
505 (RT->rt_ifp->int_state & IS_PASSIVE) &&
506 !(RT->rt_state & RS_MHOME))
507 return (0);
508 /*
509 * Do not advertise routes learnt from /etc/gateways.
510 */
511 if (RT->rt_spares[0].rts_origin == RO_FILE)
512 return (0);
513
514 /*
515 * Do not advertise routes which would lead to forwarding on a
516 * non-forwarding interface.
517 */
518 if (RT->rt_state & RS_NOPROPAGATE)
519 return (0);
520
521 /*
522 * If being quiet about our ability to forward, then
523 * do not say anything unless responding to a query,
524 * except about our main interface.
525 */
526 if (!should_supply(NULL) && !(ws.state & WS_ST_QUERY) &&
527 !(RT->rt_state & RS_MHOME))
528 return (0);
529
530 dst = RT->rt_dst;
531
532 /*
533 * do not collide with the fake default route
534 */
535 if (dst == RIP_DEFAULT && (ws.state & WS_ST_DEFAULT))
536 return (0);
537
538 if (RT->rt_state & RS_NET_SYN) {
539 if (RT->rt_state & RS_NET_INT) {
540 /*
541 * Do not send manual synthetic network routes
542 * into the subnet.
543 */
544 if (on_net(ws.to.sin_addr.s_addr,
545 ntohl(dst), RT->rt_mask))
546 return (0);
547
548 } else {
549 /*
550 * Do not send automatic synthetic network routes
551 * if they are not needed because no RIPv1 listeners
552 * can hear them.
553 */
554 if (ws.state & WS_ST_RIP2_ALL)
555 return (0);
556
557 /*
558 * Do not send automatic synthetic network routes to
559 * the real subnet.
560 */
561 if (on_net(ws.to.sin_addr.s_addr,
562 ntohl(dst), RT->rt_mask))
563 return (0);
564 }
565 nhop = 0;
566
567 } else {
568 /*
569 * Advertise the next hop if this is not a route for one
570 * of our interfaces and the next hop is on the same
571 * network as the target.
572 * The final determination is made by supply_out().
573 */
574 if (!(RT->rt_state & RS_IF) && !(RT->rt_state & RS_MHOME) &&
575 RT->rt_gate != loopaddr)
576 nhop = RT->rt_gate;
577 else
578 nhop = 0;
579 }
580
581 metric = RT->rt_metric;
582 ags = 0;
583
584 if (!RT_ISHOST(RT)) {
585 /*
586 * Always suppress network routes into other, existing
587 * network routes
588 */
589 ags |= AGS_SUPPRESS;
590
591 /*
592 * Generate supernets if allowed.
593 * If we can be heard by RIPv1 systems, we will
594 * later convert back to ordinary nets.
595 * This unifies dealing with received supernets.
596 */
597 if ((ws.state & WS_ST_AG) && ((RT->rt_state & RS_SUBNET) ||
598 (ws.state & WS_ST_SUPER_AG)))
599 ags |= AGS_AGGREGATE;
600 } else if (!(RT->rt_state & RS_MHOME)) {
601 /*
602 * We should always suppress (into existing network routes)
603 * the host routes for the local end of our point-to-point
604 * links.
605 * If we are suppressing host routes in general, then do so.
606 * Avoid advertising host routes onto their own network,
607 * where they should be handled by proxy-ARP.
608 */
609 if ((RT->rt_state & RS_LOCAL) || ridhosts ||
610 on_net(dst, ws.to_net, ws.to_mask))
611 ags |= AGS_SUPPRESS;
612
613 /*
614 * Aggregate stray host routes into network routes if allowed.
615 * We cannot aggregate host routes into small network routes
616 * without confusing RIPv1 listeners into thinking the
617 * network routes are host routes.
618 */
619 if ((ws.state & WS_ST_AG) && (ws.state & WS_ST_RIP2_ALL))
620 ags |= AGS_AGGREGATE;
621 }
622
623 /*
624 * Do not send RIPv1 advertisements of subnets to other
625 * networks. If possible, multicast them by RIPv2.
626 */
627 if ((RT->rt_state & RS_SUBNET) && !(ws.state & WS_ST_RIP2_ALL) &&
628 !on_net(dst, ws.to_std_net, ws.to_std_mask))
629 ags |= AGS_RIPV2 | AGS_AGGREGATE;
630
631
632 /*
633 * Do not send a route back to where it came from, except in
634 * response to a query. This is "split-horizon". That means not
635 * advertising back to the same network and so via the same interface.
636 *
637 * We want to suppress routes that might have been fragmented
638 * from this route by a RIPv1 router and sent back to us, and so we
639 * cannot forget this route here. Let the split-horizon route
640 * suppress the fragmented routes and then itself be forgotten.
641 *
642 * Include the routes for both ends of point-to-point interfaces
643 * among those suppressed by split-horizon, since the other side
644 * should knows them as well as we do.
645 *
646 * Notice spare routes with the same metric that we are about to
647 * advertise, to split the horizon on redundant, inactive paths.
648 */
649 if (ws.ifp != NULL && !(ws.state & WS_ST_QUERY) &&
650 (ws.state & WS_ST_TO_ON_NET) && (!(RT->rt_state & RS_IF) ||
651 (ws.ifp->int_if_flags & IFF_POINTOPOINT))) {
652 for (rts = RT->rt_spares, sparecount = 0;
653 sparecount < RT->rt_num_spares; sparecount++, rts++) {
654 if (rts->rts_metric > metric || rts->rts_ifp != ws.ifp)
655 continue;
656
657 /*
658 * If we do not mark the route with AGS_SPLIT_HZ here,
659 * it will be poisoned-reverse, or advertised back
660 * toward its source with an infinite metric.
661 * If we have recently advertised the route with a
662 * better metric than we now have, then we should
663 * poison-reverse the route before suppressing it for
664 * split-horizon.
665 *
666 * In almost all cases, if there is no spare for the
667 * route then it is either old and dead or a brand
668 * new route. If it is brand new, there is no need
669 * for poison-reverse. If it is old and dead, it
670 * is already poisoned.
671 */
672 if (RT->rt_poison_time < now_expire ||
673 RT->rt_poison_metric >= metric ||
674 RT->rt_spares[1].rts_gate == 0) {
675 ags |= AGS_SPLIT_HZ;
676 ags &= ~AGS_SUPPRESS;
677 }
678 metric = HOPCNT_INFINITY;
679 break;
680 }
681 }
682
683 /*
684 * Keep track of the best metric with which the
685 * route has been advertised recently.
686 */
687 if (RT->rt_poison_metric >= metric ||
688 RT->rt_poison_time < now_expire) {
689 RT->rt_poison_time = now.tv_sec;
690 RT->rt_poison_metric = metric;
691 }
692
693 /*
694 * Adjust the outgoing metric by the cost of the link.
695 * Avoid aggregation when a route is counting to infinity.
696 */
697 pref = RT->rt_poison_metric + ws.metric;
698 metric += ws.metric;
699
700 /*
701 * If this is a static route pointing to the same interface
702 * upon which we are sending out the RIP RESPONSE
703 * adjust the preference so that we don't aggregate into this
704 * route. Note that the maximum possible hop count on a route
705 * per RFC 2453 is 16 (HOPCNT_INFINITY)
706 */
707 if ((RT->rt_state & RS_STATIC) && (ws.ifp == RT->rt_ifp))
708 pref = (HOPCNT_INFINITY+1);
709
710 /*
711 * Do not advertise stable routes that will be ignored,
712 * unless we are answering a query.
713 * If the route recently was advertised with a metric that
714 * would have been less than infinity through this interface,
715 * we need to continue to advertise it in order to poison it.
716 */
717 if (metric >= HOPCNT_INFINITY) {
718 if (!(ws.state & WS_ST_QUERY) && (pref >= HOPCNT_INFINITY ||
719 RT->rt_poison_time < now_garbage))
720 return (0);
721
722 metric = HOPCNT_INFINITY;
723 }
724
725 /*
726 * supply this route out on the wire- we only care about dest/mask
727 * and so can ignore all rt_spares[i] with i > 0
728 */
729 ag_check(dst, RT->rt_mask, 0, RT->rt_ifp, nhop, metric, pref,
730 RT->rt_seqno, RT->rt_tag, ags, supply_out);
731 return (0);
732 #undef RT
733 }
734
735
736 /*
737 * Supply dst with the contents of the routing tables.
738 * If this won't fit in one packet, chop it up into several.
739 */
740 void
supply(struct sockaddr_in * dst,struct interface * ifp,enum output_type type,int flash,int vers,boolean_t passwd_ok)741 supply(struct sockaddr_in *dst,
742 struct interface *ifp, /* output interface */
743 enum output_type type,
744 int flash, /* 1=flash update */
745 int vers, /* RIP version */
746 boolean_t passwd_ok) /* OK to include cleartext password */
747 {
748 struct rt_entry *rt;
749 uint8_t def_metric;
750
751
752 ws.state = 0;
753 ws.gen_limit = WS_GEN_LIMIT_MAX;
754
755 ws.to = *dst;
756 ws.to_std_mask = std_mask(ws.to.sin_addr.s_addr);
757 ws.to_std_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_std_mask;
758
759 if (ifp != NULL) {
760 ws.to_mask = ifp->int_mask;
761 ws.to_net = ifp->int_net;
762 if (on_net(ws.to.sin_addr.s_addr, ws.to_net, ws.to_mask) ||
763 type == OUT_MULTICAST)
764 ws.state |= WS_ST_TO_ON_NET;
765
766 } else {
767 ws.to_mask = ripv1_mask_net(ws.to.sin_addr.s_addr, NULL);
768 ws.to_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_mask;
769 rt = rtfind(dst->sin_addr.s_addr);
770 if (rt != NULL)
771 ifp = rt->rt_ifp;
772 else
773 return;
774 }
775
776 ws.npackets = 0;
777 if (flash)
778 ws.state |= WS_ST_FLASH;
779
780 ws.ifp = ifp;
781
782 /*
783 * Routes in the table were already adjusted by their respective
784 * destination interface costs (which are zero by default) on
785 * input. The following is the value by which each route's metric
786 * will be bumped up on output.
787 */
788 ws.metric = 1;
789
790 ripv12_buf.rip.rip_vers = vers;
791
792 switch (type) {
793 case OUT_MULTICAST:
794 if (ifp->int_if_flags & IFF_MULTICAST)
795 v2buf.type = OUT_MULTICAST;
796 else
797 v2buf.type = NO_OUT_MULTICAST;
798 v12buf.type = OUT_BROADCAST;
799 break;
800
801 case OUT_QUERY:
802 ws.state |= WS_ST_QUERY;
803 /* FALLTHROUGH */
804 case OUT_BROADCAST:
805 case OUT_UNICAST:
806 v2buf.type = (vers == RIPv2) ? type : NO_OUT_RIPV2;
807 v12buf.type = type;
808 break;
809
810 case NO_OUT_MULTICAST:
811 case NO_OUT_RIPV2:
812 return; /* no output */
813 }
814
815 if (vers == RIPv2) {
816 /* full RIPv2 only if cannot be heard by RIPv1 listeners */
817 if (type != OUT_BROADCAST)
818 ws.state |= WS_ST_RIP2_ALL;
819 if ((ws.state & WS_ST_QUERY) || !(ws.state & WS_ST_TO_ON_NET)) {
820 ws.state |= (WS_ST_AG | WS_ST_SUPER_AG);
821 } else if (ifp == NULL || !(ifp->int_state & IS_NO_AG)) {
822 ws.state |= WS_ST_AG;
823 if (type != OUT_BROADCAST && (ifp == NULL ||
824 !(ifp->int_state & IS_NO_SUPER_AG)))
825 ws.state |= WS_ST_SUPER_AG;
826 }
827
828 /* See if this packet needs authenticating */
829 ws.a = find_auth(ifp);
830 if (!passwd_ok && ws.a != NULL && ws.a->type == RIP_AUTH_PW)
831 ws.a = NULL;
832 if (ws.a != NULL && (ulong_t)ws.a->end < (ulong_t)clk.tv_sec &&
833 !ws.a->warnedflag) {
834 /*
835 * If the best key is an expired one, we may as
836 * well use it. Log this event.
837 */
838 writelog(LOG_WARNING,
839 "Using expired auth while transmitting to %s",
840 naddr_ntoa(ws.to.sin_addr.s_addr));
841 ws.a->warnedflag = 1;
842 }
843 } else {
844 ws.a = NULL;
845 }
846
847 clr_ws_buf(&v12buf, ws.a);
848 clr_ws_buf(&v2buf, ws.a);
849
850 /*
851 * Fake a default route if asked and if there is not already
852 * a better, real default route.
853 */
854 if (should_supply(NULL) && (def_metric = ifp->int_d_metric) != 0) {
855 if (NULL == (rt = rtget(RIP_DEFAULT, 0)) ||
856 rt->rt_metric+ws.metric >= def_metric) {
857 ws.state |= WS_ST_DEFAULT;
858 ag_check(0, 0, 0, NULL, 0, def_metric, def_metric,
859 0, 0, 0, supply_out);
860 } else {
861 def_metric = rt->rt_metric+ws.metric;
862 }
863
864 /*
865 * If both RIPv2 and the poor-man's router discovery
866 * kludge are on, arrange to advertise an extra
867 * default route via RIPv1.
868 */
869 if ((ws.state & WS_ST_RIP2_ALL) &&
870 (ifp->int_state & IS_PM_RDISC)) {
871 ripv12_buf.rip.rip_vers = RIPv1;
872 v12buf.n->n_family = RIP_AF_INET;
873 v12buf.n->n_dst = htonl(RIP_DEFAULT);
874 v12buf.n->n_metric = htonl(def_metric);
875 v12buf.n++;
876 }
877 }
878
879 (void) rn_walktree(rhead, walk_supply, NULL);
880 ag_flush(0, 0, supply_out);
881
882 /*
883 * Flush the packet buffers, provided they are not empty and
884 * do not contain only the password.
885 */
886 if (v12buf.n != v12buf.base &&
887 (v12buf.n > v12buf.base+1 ||
888 v12buf.base->n_family != RIP_AF_AUTH))
889 supply_write(&v12buf);
890 if (v2buf.n != v2buf.base && (v2buf.n > v2buf.base+1 ||
891 v2buf.base->n_family != RIP_AF_AUTH))
892 supply_write(&v2buf);
893
894 /*
895 * If we sent nothing and this is an answer to a query, send
896 * an empty buffer.
897 */
898 if (ws.npackets == 0 && (ws.state & WS_ST_QUERY)) {
899 supply_write(&v2buf);
900 if (ws.npackets == 0)
901 supply_write(&v12buf);
902 }
903 }
904
905
906 /*
907 * send all of the routing table or just do a flash update
908 */
909 void
rip_bcast(int flash)910 rip_bcast(int flash)
911 {
912 static struct sockaddr_in dst = {AF_INET};
913 struct interface *ifp;
914 enum output_type type;
915 int vers;
916 struct timeval rtime;
917
918
919 need_flash = _B_FALSE;
920 intvl_random(&rtime, MIN_WAITTIME, MAX_WAITTIME);
921 no_flash = rtime;
922 timevaladd(&no_flash, &now);
923
924 if (!rip_enabled)
925 return;
926
927 trace_act("send %s and inhibit dynamic updates for %.3f sec",
928 flash ? "dynamic update" : "all routes",
929 rtime.tv_sec + ((double)rtime.tv_usec)/1000000.0);
930
931 for (ifp = ifnet; ifp != NULL; ifp = ifp->int_next) {
932 /*
933 * Skip interfaces not doing RIP or for which IP
934 * forwarding isn't turned on. Skip duplicate
935 * interfaces, we don't want to generate duplicate
936 * packets. Do try broken interfaces to see if they
937 * have healed.
938 */
939 if (IS_RIP_OUT_OFF(ifp->int_state) ||
940 (ifp->int_state & IS_DUP) ||
941 !IS_IFF_ROUTING(ifp->int_if_flags))
942 continue;
943
944 /* skip turned off interfaces */
945 if (!IS_IFF_UP(ifp->int_if_flags))
946 continue;
947
948 /* skip interfaces we shouldn't use */
949 if (IS_IFF_QUIET(ifp->int_if_flags))
950 continue;
951
952 vers = (ifp->int_state & IS_NO_RIPV1_OUT) ? RIPv2 : RIPv1;
953 dst.sin_addr.s_addr = ifp->int_ripout_addr;
954
955 /*
956 * Ignore the interface if it's not broadcast,
957 * point-to-point, or remote. It must be non-broadcast
958 * multiaccess, and therefore unsupported.
959 */
960 if (!(ifp->int_if_flags & (IFF_BROADCAST | IFF_POINTOPOINT)) &&
961 !(ifp->int_state & IS_REMOTE))
962 continue;
963
964 type = (ifp->int_if_flags & IFF_BROADCAST) ?
965 OUT_BROADCAST : OUT_UNICAST;
966 if (vers == RIPv2 && (ifp->int_if_flags & IFF_MULTICAST) &&
967 !(ifp->int_state & IS_NO_RIP_MCAST))
968 type = OUT_MULTICAST;
969
970 supply(&dst, ifp, type, flash, vers, _B_TRUE);
971 }
972
973 update_seqno++; /* all routes are up to date */
974 }
975
976
977 /*
978 * Ask for routes
979 * Do it only once to an interface, and not even after the interface
980 * was broken and recovered.
981 */
982 void
rip_query(void)983 rip_query(void)
984 {
985 static struct sockaddr_in dst = {AF_INET};
986 struct interface *ifp;
987 struct rip buf;
988 enum output_type type;
989
990
991 if (!rip_enabled)
992 return;
993
994 (void) memset(&buf, 0, sizeof (buf));
995
996 for (ifp = ifnet; ifp; ifp = ifp->int_next) {
997 /*
998 * Skip interfaces those already queried. Do not ask
999 * via interfaces through which we don't accept input.
1000 * Do not ask via interfaces that cannot send RIP
1001 * packets. Don't send queries on duplicate
1002 * interfaces, that would generate duplicate packets
1003 * on link. Do try broken interfaces to see if they
1004 * have healed.
1005 */
1006 if (IS_RIP_IN_OFF(ifp->int_state) ||
1007 (ifp->int_state & IS_DUP) ||
1008 ifp->int_query_time != NEVER)
1009 continue;
1010
1011 /* skip turned off interfaces */
1012 if (!IS_IFF_UP(ifp->int_if_flags))
1013 continue;
1014
1015 /* skip interfaces we shouldn't use */
1016 if (IS_IFF_QUIET(ifp->int_if_flags))
1017 continue;
1018
1019 /*
1020 * Ignore the interface if it's not broadcast,
1021 * point-to-point, or remote. It must be non-broadcast
1022 * multiaccess, and therefore unsupported.
1023 */
1024 if (!(ifp->int_if_flags & (IFF_BROADCAST | IFF_POINTOPOINT)) &&
1025 !(ifp->int_state & IS_REMOTE))
1026 continue;
1027
1028 buf.rip_cmd = RIPCMD_REQUEST;
1029 buf.rip_nets[0].n_family = RIP_AF_UNSPEC;
1030 buf.rip_nets[0].n_metric = htonl(HOPCNT_INFINITY);
1031
1032 /*
1033 * Send a RIPv1 query only if allowed and if we will
1034 * listen to RIPv1 routers.
1035 */
1036 if ((ifp->int_state & IS_NO_RIPV1_OUT) ||
1037 (ifp->int_state & IS_NO_RIPV1_IN)) {
1038 buf.rip_vers = RIPv2;
1039 } else {
1040 buf.rip_vers = RIPv1;
1041 }
1042
1043 dst.sin_addr.s_addr = ifp->int_ripout_addr;
1044
1045 type = (ifp->int_if_flags & IFF_BROADCAST) ?
1046 OUT_BROADCAST : OUT_UNICAST;
1047 if (buf.rip_vers == RIPv2 &&
1048 (ifp->int_if_flags & IFF_MULTICAST) &&
1049 !(ifp->int_state & IS_NO_RIP_MCAST))
1050 type = OUT_MULTICAST;
1051
1052 ifp->int_query_time = now.tv_sec+SUPPLY_INTERVAL;
1053 if (output(type, &dst, ifp, &buf, sizeof (buf)) < 0)
1054 if_sick(ifp, _B_FALSE);
1055 }
1056 }
1057