xref: /freebsd/sbin/routed/output.c (revision ad30f8e79bd1007cc2476e491bd21b4f5e389e0a)
1 /*
2  * Copyright (c) 1983, 1988, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
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.
16  *
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
27  * SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 
32 #include "defs.h"
33 
34 #ifdef __NetBSD__
35 __RCSID("$NetBSD$");
36 #elif defined(__FreeBSD__)
37 __RCSID("$FreeBSD$");
38 #else
39 __RCSID("$Revision: 2.27 $");
40 #ident "$Revision: 2.27 $"
41 #endif
42 
43 
44 u_int update_seqno;
45 
46 
47 /* walk the tree of routes with this for output
48  */
49 static struct {
50 	struct sockaddr_in to;
51 	naddr	to_mask;
52 	naddr	to_net;
53 	naddr	to_std_mask;
54 	naddr	to_std_net;
55 	struct interface *ifp;		/* usually output interface */
56 	struct auth *a;
57 	char	metric;			/* adjust metrics by interface */
58 	int	npackets;
59 	int	gen_limit;
60 	u_int	state;
61 #define	    WS_ST_FLASH	    0x001	/* send only changed routes */
62 #define	    WS_ST_RIP2_ALL  0x002	/* send full featured RIPv2 */
63 #define	    WS_ST_AG	    0x004	/* ok to aggregate subnets */
64 #define	    WS_ST_SUPER_AG  0x008	/* ok to aggregate networks */
65 #define	    WS_ST_QUERY	    0x010	/* responding to a query */
66 #define	    WS_ST_TO_ON_NET 0x020	/* sending onto one of our nets */
67 #define	    WS_ST_DEFAULT   0x040	/* faking a default */
68 } ws;
69 
70 /* A buffer for what can be heard by both RIPv1 and RIPv2 listeners */
71 struct ws_buf v12buf;
72 static union pkt_buf ripv12_buf;
73 
74 /* Another for only RIPv2 listeners */
75 static struct ws_buf v2buf;
76 static union pkt_buf rip_v2_buf;
77 
78 
79 
80 void
81 bufinit(void)
82 {
83 	ripv12_buf.rip.rip_cmd = RIPCMD_RESPONSE;
84 	v12buf.buf = &ripv12_buf.rip;
85 	v12buf.base = &v12buf.buf->rip_nets[0];
86 
87 	rip_v2_buf.rip.rip_cmd = RIPCMD_RESPONSE;
88 	rip_v2_buf.rip.rip_vers = RIPv2;
89 	v2buf.buf = &rip_v2_buf.rip;
90 	v2buf.base = &v2buf.buf->rip_nets[0];
91 }
92 
93 
94 /* Send the contents of the global buffer via the non-multicast socket
95  */
96 int					/* <0 on failure */
97 output(enum output_type type,
98        struct sockaddr_in *dst,		/* send to here */
99        struct interface *ifp,
100        struct rip *buf,
101        int size)			/* this many bytes */
102 {
103 	struct sockaddr_in osin;
104 	int flags;
105 	const char *msg;
106 	int res;
107 	int soc;
108 	int serrno;
109 
110 	assert(ifp != NULL);
111 	osin = *dst;
112 	if (osin.sin_port == 0)
113 		osin.sin_port = htons(RIP_PORT);
114 #ifdef _HAVE_SIN_LEN
115 	if (osin.sin_len == 0)
116 		osin.sin_len = sizeof(osin);
117 #endif
118 
119 	soc = rip_sock;
120 	flags = 0;
121 
122 	switch (type) {
123 	case OUT_QUERY:
124 		msg = "Answer Query";
125 		if (soc < 0)
126 			soc = ifp->int_rip_sock;
127 		break;
128 	case OUT_UNICAST:
129 		msg = "Send";
130 		if (soc < 0)
131 			soc = ifp->int_rip_sock;
132 		flags = MSG_DONTROUTE;
133 		break;
134 	case OUT_BROADCAST:
135 		if (ifp->int_if_flags & IFF_POINTOPOINT) {
136 			msg = "Send";
137 		} else {
138 			msg = "Send bcast";
139 		}
140 		flags = MSG_DONTROUTE;
141 		break;
142 	case OUT_MULTICAST:
143 		if ((ifp->int_if_flags & (IFF_POINTOPOINT|IFF_MULTICAST)) ==
144 		    IFF_POINTOPOINT) {
145 			msg = "Send pt-to-pt";
146 		} else if (ifp->int_state & IS_DUP) {
147 			trace_act("abort multicast output via %s"
148 				  " with duplicate address",
149 				  ifp->int_name);
150 			return 0;
151 		} else {
152 			msg = "Send mcast";
153 			if (rip_sock_mcast != ifp) {
154 				struct ip_mreqn mreqn;
155 
156 				memset(&mreqn, 0, sizeof(struct ip_mreqn));
157 				mreqn.imr_ifindex = ifp->int_index;
158 				if (0 > setsockopt(rip_sock,
159 						   IPPROTO_IP,
160 						   IP_MULTICAST_IF,
161 						   &mreqn,
162 						   sizeof(mreqn))) {
163 					serrno = errno;
164 					LOGERR("setsockopt(rip_sock, "
165 					       "IP_MULTICAST_IF)");
166 					errno = serrno;
167 					ifp = 0;
168 					return -1;
169 				}
170 				rip_sock_mcast = ifp;
171 			}
172 			osin.sin_addr.s_addr = htonl(INADDR_RIP_GROUP);
173 		}
174 		break;
175 
176 	case NO_OUT_MULTICAST:
177 	case NO_OUT_RIPV2:
178 	default:
179 #ifdef DEBUG
180 		abort();
181 #endif
182 		return -1;
183 	}
184 
185 	trace_rip(msg, "to", &osin, ifp, buf, size);
186 
187 	res = sendto(soc, buf, size, flags,
188 		     (struct sockaddr *)&osin, sizeof(osin));
189 	if (res < 0
190 	    && (ifp == 0 || !(ifp->int_state & IS_BROKE))) {
191 		serrno = errno;
192 		msglog("%s sendto(%s%s%s.%d): %s", msg,
193 		       ifp != 0 ? ifp->int_name : "",
194 		       ifp != 0 ? ", " : "",
195 		       inet_ntoa(osin.sin_addr),
196 		       ntohs(osin.sin_port),
197 		       strerror(errno));
198 		errno = serrno;
199 	}
200 
201 	return res;
202 }
203 
204 
205 /* Find the first key for a packet to send.
206  * Try for a key that is eligible and has not expired, but settle for
207  * the last key if they have all expired.
208  * If no key is ready yet, give up.
209  */
210 struct auth *
211 find_auth(struct interface *ifp)
212 {
213 	struct auth *ap, *res;
214 	int i;
215 
216 
217 	if (ifp == 0)
218 		return 0;
219 
220 	res = 0;
221 	ap = ifp->int_auth;
222 	for (i = 0; i < MAX_AUTH_KEYS; i++, ap++) {
223 		/* stop looking after the last key */
224 		if (ap->type == RIP_AUTH_NONE)
225 			break;
226 
227 		/* ignore keys that are not ready yet */
228 		if ((u_long)ap->start > (u_long)clk.tv_sec)
229 			continue;
230 
231 		if ((u_long)ap->end < (u_long)clk.tv_sec) {
232 			/* note best expired password as a fall-back */
233 			if (res == 0 || (u_long)ap->end > (u_long)res->end)
234 				res = ap;
235 			continue;
236 		}
237 
238 		/* note key with the best future */
239 		if (res == 0 || (u_long)res->end < (u_long)ap->end)
240 			res = ap;
241 	}
242 	return res;
243 }
244 
245 
246 void
247 clr_ws_buf(struct ws_buf *wb,
248 	   struct auth *ap)
249 {
250 	struct netauth *na;
251 
252 	wb->lim = wb->base + NETS_LEN;
253 	wb->n = wb->base;
254 	memset(wb->n, 0, NETS_LEN*sizeof(*wb->n));
255 
256 	/* (start to) install authentication if appropriate
257 	 */
258 	if (ap == 0)
259 		return;
260 
261 	na = (struct netauth*)wb->n;
262 	if (ap->type == RIP_AUTH_PW) {
263 		na->a_family = RIP_AF_AUTH;
264 		na->a_type = RIP_AUTH_PW;
265 		memcpy(na->au.au_pw, ap->key, sizeof(na->au.au_pw));
266 		wb->n++;
267 
268 	} else if (ap->type ==  RIP_AUTH_MD5) {
269 		na->a_family = RIP_AF_AUTH;
270 		na->a_type = RIP_AUTH_MD5;
271 		na->au.a_md5.md5_keyid = ap->keyid;
272 		na->au.a_md5.md5_auth_len = RIP_AUTH_MD5_KEY_LEN;
273 		na->au.a_md5.md5_seqno = htonl(clk.tv_sec);
274 		wb->n++;
275 		wb->lim--;		/* make room for trailer */
276 	}
277 }
278 
279 
280 void
281 end_md5_auth(struct ws_buf *wb,
282 	     struct auth *ap)
283 {
284 	struct netauth *na, *na2;
285 	MD5_CTX md5_ctx;
286 	int len;
287 
288 
289 	na = (struct netauth*)wb->base;
290 	na2 = (struct netauth*)wb->n;
291 	len = (char *)na2-(char *)wb->buf;
292 	na2->a_family = RIP_AF_AUTH;
293 	na2->a_type = htons(1);
294 	na->au.a_md5.md5_pkt_len = htons(len);
295 	MD5Init(&md5_ctx);
296 	MD5Update(&md5_ctx, (u_char *)wb->buf, len + RIP_AUTH_MD5_HASH_XTRA);
297 	MD5Update(&md5_ctx, ap->key, RIP_AUTH_MD5_KEY_LEN);
298 	MD5Final(na2->au.au_pw, &md5_ctx);
299 	wb->n++;
300 }
301 
302 
303 /* Send the buffer
304  */
305 static void
306 supply_write(struct ws_buf *wb)
307 {
308 	/* Output multicast only if legal.
309 	 * If we would multicast and it would be illegal, then discard the
310 	 * packet.
311 	 */
312 	switch (wb->type) {
313 	case NO_OUT_MULTICAST:
314 		trace_pkt("skip multicast to %s because impossible",
315 			  naddr_ntoa(ws.to.sin_addr.s_addr));
316 		break;
317 	case NO_OUT_RIPV2:
318 		break;
319 	default:
320 		if (ws.a != 0 && ws.a->type == RIP_AUTH_MD5)
321 			end_md5_auth(wb,ws.a);
322 		if (output(wb->type, &ws.to, ws.ifp, wb->buf,
323 			   ((char *)wb->n - (char*)wb->buf)) < 0
324 		    && ws.ifp != 0)
325 			if_sick(ws.ifp);
326 		ws.npackets++;
327 		break;
328 	}
329 
330 	clr_ws_buf(wb,ws.a);
331 }
332 
333 
334 /* put an entry into the packet
335  */
336 static void
337 supply_out(struct ag_info *ag)
338 {
339 	int i;
340 	naddr mask, v1_mask, dst_h, ddst_h = 0;
341 	struct ws_buf *wb;
342 
343 
344 	/* Skip this route if doing a flash update and it and the routes
345 	 * it aggregates have not changed recently.
346 	 */
347 	if (ag->ag_seqno < update_seqno
348 	    && (ws.state & WS_ST_FLASH))
349 		return;
350 
351 	dst_h = ag->ag_dst_h;
352 	mask = ag->ag_mask;
353 	v1_mask = ripv1_mask_host(htonl(dst_h),
354 				  (ws.state & WS_ST_TO_ON_NET) ? ws.ifp : 0);
355 	i = 0;
356 
357 	/* If we are sending RIPv2 packets that cannot (or must not) be
358 	 * heard by RIPv1 listeners, do not worry about sub- or supernets.
359 	 * Subnets (from other networks) can only be sent via multicast.
360 	 * A pair of subnet routes might have been promoted so that they
361 	 * are legal to send by RIPv1.
362 	 * If RIPv1 is off, use the multicast buffer.
363 	 */
364 	if ((ws.state & WS_ST_RIP2_ALL)
365 	    || ((ag->ag_state & AGS_RIPV2) && v1_mask != mask)) {
366 		/* use the RIPv2-only buffer */
367 		wb = &v2buf;
368 
369 	} else {
370 		/* use the RIPv1-or-RIPv2 buffer */
371 		wb = &v12buf;
372 
373 		/* Convert supernet route into corresponding set of network
374 		 * routes for RIPv1, but leave non-contiguous netmasks
375 		 * to ag_check().
376 		 */
377 		if (v1_mask > mask
378 		    && mask + (mask & -mask) == 0) {
379 			ddst_h = v1_mask & -v1_mask;
380 			i = (v1_mask & ~mask)/ddst_h;
381 
382 			if (i > ws.gen_limit) {
383 				/* Punt if we would have to generate an
384 				 * unreasonable number of routes.
385 				 */
386 				if (TRACECONTENTS)
387 					trace_misc("sending %s-->%s as 1"
388 						   " instead of %d routes",
389 						   addrname(htonl(dst_h), mask,
390 							1),
391 						   naddr_ntoa(ws.to.sin_addr
392 							.s_addr),
393 						   i+1);
394 				i = 0;
395 
396 			} else {
397 				mask = v1_mask;
398 				ws.gen_limit -= i;
399 			}
400 		}
401 	}
402 
403 	do {
404 		wb->n->n_family = RIP_AF_INET;
405 		wb->n->n_dst = htonl(dst_h);
406 		/* If the route is from router-discovery or we are
407 		 * shutting down, admit only a bad metric.
408 		 */
409 		wb->n->n_metric = ((stopint || ag->ag_metric < 1)
410 				   ? HOPCNT_INFINITY
411 				   : ag->ag_metric);
412 		wb->n->n_metric = htonl(wb->n->n_metric);
413 		/* Any non-zero bits in the supposedly unused RIPv1 fields
414 		 * cause the old `routed` to ignore the route.
415 		 * That means the mask and so forth cannot be sent
416 		 * in the hybrid RIPv1/RIPv2 mode.
417 		 */
418 		if (ws.state & WS_ST_RIP2_ALL) {
419 			if (ag->ag_nhop != 0
420 			    && ((ws.state & WS_ST_QUERY)
421 				|| (ag->ag_nhop != ws.ifp->int_addr
422 				    && on_net(ag->ag_nhop,
423 					      ws.ifp->int_net,
424 					      ws.ifp->int_mask))))
425 				wb->n->n_nhop = ag->ag_nhop;
426 			wb->n->n_mask = htonl(mask);
427 			wb->n->n_tag = ag->ag_tag;
428 		}
429 		dst_h += ddst_h;
430 
431 		if (++wb->n >= wb->lim)
432 			supply_write(wb);
433 	} while (i-- != 0);
434 }
435 
436 
437 /* supply one route from the table
438  */
439 /* ARGSUSED */
440 static int
441 walk_supply(struct radix_node *rn,
442 	    struct walkarg *argp UNUSED)
443 {
444 #define RT ((struct rt_entry *)rn)
445 	u_short ags;
446 	char metric, pref;
447 	naddr dst, nhop;
448 	struct rt_spare *rts;
449 	int i;
450 
451 
452 	/* Do not advertise external remote interfaces or passive interfaces.
453 	 */
454 	if ((RT->rt_state & RS_IF)
455 	    && RT->rt_ifp != 0
456 	    && (RT->rt_ifp->int_state & IS_PASSIVE)
457 	    && !(RT->rt_state & RS_MHOME))
458 		return 0;
459 
460 	/* If being quiet about our ability to forward, then
461 	 * do not say anything unless responding to a query,
462 	 * except about our main interface.
463 	 */
464 	if (!supplier && !(ws.state & WS_ST_QUERY)
465 	    && !(RT->rt_state & RS_MHOME))
466 		return 0;
467 
468 	dst = RT->rt_dst;
469 
470 	/* do not collide with the fake default route */
471 	if (dst == RIP_DEFAULT
472 	    && (ws.state & WS_ST_DEFAULT))
473 		return 0;
474 
475 	if (RT->rt_state & RS_NET_SYN) {
476 		if (RT->rt_state & RS_NET_INT) {
477 			/* Do not send manual synthetic network routes
478 			 * into the subnet.
479 			 */
480 			if (on_net(ws.to.sin_addr.s_addr,
481 				   ntohl(dst), RT->rt_mask))
482 				return 0;
483 
484 		} else {
485 			/* Do not send automatic synthetic network routes
486 			 * if they are not needed because no RIPv1 listeners
487 			 * can hear them.
488 			 */
489 			if (ws.state & WS_ST_RIP2_ALL)
490 				return 0;
491 
492 			/* Do not send automatic synthetic network routes to
493 			 * the real subnet.
494 			 */
495 			if (on_net(ws.to.sin_addr.s_addr,
496 				   ntohl(dst), RT->rt_mask))
497 				return 0;
498 		}
499 		nhop = 0;
500 
501 	} else {
502 		/* Advertise the next hop if this is not a route for one
503 		 * of our interfaces and the next hop is on the same
504 		 * network as the target.
505 		 * The final determination is made by supply_out().
506 		 */
507 		if (!(RT->rt_state & RS_IF)
508 		    && RT->rt_gate != myaddr
509 		    && RT->rt_gate != loopaddr)
510 			nhop = RT->rt_gate;
511 		else
512 			nhop = 0;
513 	}
514 
515 	metric = RT->rt_metric;
516 	ags = 0;
517 
518 	if (RT->rt_state & RS_MHOME) {
519 		/* retain host route of multi-homed servers */
520 		;
521 
522 	} else if (RT_ISHOST(RT)) {
523 		/* We should always suppress (into existing network routes)
524 		 * the host routes for the local end of our point-to-point
525 		 * links.
526 		 * If we are suppressing host routes in general, then do so.
527 		 * Avoid advertising host routes onto their own network,
528 		 * where they should be handled by proxy-ARP.
529 		 */
530 		if ((RT->rt_state & RS_LOCAL)
531 		    || ridhosts
532 		    || on_net(dst, ws.to_net, ws.to_mask))
533 			ags |= AGS_SUPPRESS;
534 
535 		/* Aggregate stray host routes into network routes if allowed.
536 		 * We cannot aggregate host routes into small network routes
537 		 * without confusing RIPv1 listeners into thinking the
538 		 * network routes are host routes.
539 		 */
540 		if ((ws.state & WS_ST_AG) && (ws.state & WS_ST_RIP2_ALL))
541 			ags |= AGS_AGGREGATE;
542 
543 	} else {
544 		/* Always suppress network routes into other, existing
545 		 * network routes
546 		 */
547 		ags |= AGS_SUPPRESS;
548 
549 		/* Generate supernets if allowed.
550 		 * If we can be heard by RIPv1 systems, we will
551 		 * later convert back to ordinary nets.
552 		 * This unifies dealing with received supernets.
553 		 */
554 		if ((ws.state & WS_ST_AG)
555 		    && ((RT->rt_state & RS_SUBNET)
556 			|| (ws.state & WS_ST_SUPER_AG)))
557 			ags |= AGS_AGGREGATE;
558 	}
559 
560 	/* Do not send RIPv1 advertisements of subnets to other
561 	 * networks. If possible, multicast them by RIPv2.
562 	 */
563 	if ((RT->rt_state & RS_SUBNET)
564 	    && !(ws.state & WS_ST_RIP2_ALL)
565 	    && !on_net(dst, ws.to_std_net, ws.to_std_mask))
566 		ags |= AGS_RIPV2 | AGS_AGGREGATE;
567 
568 
569 	/* Do not send a route back to where it came from, except in
570 	 * response to a query.  This is "split-horizon".  That means not
571 	 * advertising back to the same network	and so via the same interface.
572 	 *
573 	 * We want to suppress routes that might have been fragmented
574 	 * from this route by a RIPv1 router and sent back to us, and so we
575 	 * cannot forget this route here.  Let the split-horizon route
576 	 * suppress the fragmented routes and then itself be forgotten.
577 	 *
578 	 * Include the routes for both ends of point-to-point interfaces
579 	 * among those suppressed by split-horizon, since the other side
580 	 * should knows them as well as we do.
581 	 *
582 	 * Notice spare routes with the same metric that we are about to
583 	 * advertise, to split the horizon on redundant, inactive paths.
584 	 *
585 	 * Do not suppress advertisements of interface-related addresses on
586 	 * non-point-to-point interfaces.  This ensures that we have something
587 	 * to say every 30 seconds to help detect broken Ethernets or
588 	 * other interfaces where one packet every 30 seconds costs nothing.
589 	 */
590 	if (ws.ifp != 0
591 	    && !(ws.state & WS_ST_QUERY)
592 	    && (ws.state & WS_ST_TO_ON_NET)
593 	    && (!(RT->rt_state & RS_IF)
594 		|| ws.ifp->int_if_flags & IFF_POINTOPOINT)) {
595 		for (rts = RT->rt_spares, i = NUM_SPARES; i != 0; i--, rts++) {
596 			if (rts->rts_metric > metric
597 			    || rts->rts_ifp != ws.ifp)
598 				continue;
599 
600 			/* If we do not mark the route with AGS_SPLIT_HZ here,
601 			 * it will be poisoned-reverse, or advertised back
602 			 * toward its source with an infinite metric.
603 			 * If we have recently advertised the route with a
604 			 * better metric than we now have, then we should
605 			 * poison-reverse the route before suppressing it for
606 			 * split-horizon.
607 			 *
608 			 * In almost all cases, if there is no spare for the
609 			 * route then it is either old and dead or a brand
610 			 * new route. If it is brand new, there is no need
611 			 * for poison-reverse. If it is old and dead, it
612 			 * is already poisoned.
613 			 */
614 			if (RT->rt_poison_time < now_expire
615 			    || RT->rt_poison_metric >= metric
616 			    || RT->rt_spares[1].rts_gate == 0) {
617 				ags |= AGS_SPLIT_HZ;
618 				ags &= ~AGS_SUPPRESS;
619 			}
620 			metric = HOPCNT_INFINITY;
621 			break;
622 		}
623 	}
624 
625 	/* Keep track of the best metric with which the
626 	 * route has been advertised recently.
627 	 */
628 	if (RT->rt_poison_metric >= metric
629 	    || RT->rt_poison_time < now_expire) {
630 		RT->rt_poison_time = now.tv_sec;
631 		RT->rt_poison_metric = metric;
632 	}
633 
634 	/* Adjust the outgoing metric by the cost of the link.
635 	 * Avoid aggregation when a route is counting to infinity.
636 	 */
637 	pref = RT->rt_poison_metric + ws.metric;
638 	metric += ws.metric;
639 
640 	/* Do not advertise stable routes that will be ignored,
641 	 * unless we are answering a query.
642 	 * If the route recently was advertised with a metric that
643 	 * would have been less than infinity through this interface,
644 	 * we need to continue to advertise it in order to poison it.
645 	 */
646 	if (metric >= HOPCNT_INFINITY) {
647 		if (!(ws.state & WS_ST_QUERY)
648 		    && (pref >= HOPCNT_INFINITY
649 			|| RT->rt_poison_time < now_garbage))
650 			return 0;
651 
652 		metric = HOPCNT_INFINITY;
653 	}
654 
655 	ag_check(dst, RT->rt_mask, 0, nhop, metric, pref,
656 		 RT->rt_seqno, RT->rt_tag, ags, supply_out);
657 	return 0;
658 #undef RT
659 }
660 
661 
662 /* Supply dst with the contents of the routing tables.
663  * If this won't fit in one packet, chop it up into several.
664  */
665 void
666 supply(struct sockaddr_in *dst,
667        struct interface *ifp,		/* output interface */
668        enum output_type type,
669        int flash,			/* 1=flash update */
670        int vers,			/* RIP version */
671        int passwd_ok)			/* OK to include cleartext password */
672 {
673 	struct rt_entry *rt;
674 	int def_metric;
675 
676 	assert(ifp != NULL);
677 
678 	ws.state = 0;
679 	ws.gen_limit = 1024;
680 
681 	ws.to = *dst;
682 	ws.to_std_mask = std_mask(ws.to.sin_addr.s_addr);
683 	ws.to_std_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_std_mask;
684 
685 	if (ifp != 0) {
686 		ws.to_mask = ifp->int_mask;
687 		ws.to_net = ifp->int_net;
688 		if (on_net(ws.to.sin_addr.s_addr, ws.to_net, ws.to_mask))
689 			ws.state |= WS_ST_TO_ON_NET;
690 
691 	} else {
692 		ws.to_mask = ripv1_mask_net(ws.to.sin_addr.s_addr, 0);
693 		ws.to_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_mask;
694 		rt = rtfind(dst->sin_addr.s_addr);
695 		if (rt)
696 			ifp = rt->rt_ifp;
697 	}
698 
699 	ws.npackets = 0;
700 	if (flash)
701 		ws.state |= WS_ST_FLASH;
702 
703 	if ((ws.ifp = ifp) == 0) {
704 		ws.metric = 1;
705 	} else {
706 		/* Adjust the advertised metric by the outgoing interface
707 		 * metric.
708 		 */
709 		ws.metric = ifp->int_metric + 1 + ifp->int_adj_outmetric;
710 	}
711 
712 	ripv12_buf.rip.rip_vers = vers;
713 
714 	switch (type) {
715 	case OUT_MULTICAST:
716 		if (ifp->int_if_flags & IFF_MULTICAST)
717 			v2buf.type = OUT_MULTICAST;
718 		else
719 			v2buf.type = NO_OUT_MULTICAST;
720 		v12buf.type = OUT_BROADCAST;
721 		break;
722 
723 	case OUT_QUERY:
724 		ws.state |= WS_ST_QUERY;
725 		/* FALLTHROUGH */
726 	case OUT_BROADCAST:
727 	case OUT_UNICAST:
728 		v2buf.type = (vers == RIPv2) ? type : NO_OUT_RIPV2;
729 		v12buf.type = type;
730 		break;
731 
732 	case NO_OUT_MULTICAST:
733 	case NO_OUT_RIPV2:
734 		break;			/* no output */
735 	}
736 
737 	if (vers == RIPv2) {
738 		/* full RIPv2 only if cannot be heard by RIPv1 listeners */
739 		if (type != OUT_BROADCAST)
740 			ws.state |= WS_ST_RIP2_ALL;
741 		if ((ws.state & WS_ST_QUERY)
742 		    || !(ws.state & WS_ST_TO_ON_NET)) {
743 			ws.state |= (WS_ST_AG | WS_ST_SUPER_AG);
744 		} else if (ifp == 0 || !(ifp->int_state & IS_NO_AG)) {
745 			ws.state |= WS_ST_AG;
746 			if (type != OUT_BROADCAST
747 			    && (ifp == 0
748 				|| !(ifp->int_state & IS_NO_SUPER_AG)))
749 				ws.state |= WS_ST_SUPER_AG;
750 		}
751 	}
752 
753 	ws.a = (vers == RIPv2) ? find_auth(ifp) : 0;
754 	if (!passwd_ok && ws.a != 0 && ws.a->type == RIP_AUTH_PW)
755 		ws.a = 0;
756 	clr_ws_buf(&v12buf,ws.a);
757 	clr_ws_buf(&v2buf,ws.a);
758 
759 	/*  Fake a default route if asked and if there is not already
760 	 * a better, real default route.
761 	 */
762 	if (supplier && (def_metric = ifp->int_d_metric) != 0) {
763 		if (0 == (rt = rtget(RIP_DEFAULT, 0))
764 		    || rt->rt_metric+ws.metric >= def_metric) {
765 			ws.state |= WS_ST_DEFAULT;
766 			ag_check(0, 0, 0, 0, def_metric, def_metric,
767 				 0, 0, 0, supply_out);
768 		} else {
769 			def_metric = rt->rt_metric+ws.metric;
770 		}
771 
772 		/* If both RIPv2 and the poor-man's router discovery
773 		 * kludge are on, arrange to advertise an extra
774 		 * default route via RIPv1.
775 		 */
776 		if ((ws.state & WS_ST_RIP2_ALL)
777 		    && (ifp->int_state & IS_PM_RDISC)) {
778 			ripv12_buf.rip.rip_vers = RIPv1;
779 			v12buf.n->n_family = RIP_AF_INET;
780 			v12buf.n->n_dst = htonl(RIP_DEFAULT);
781 			v12buf.n->n_metric = htonl(def_metric);
782 			v12buf.n++;
783 		}
784 	}
785 
786 	(void)rn_walktree(rhead, walk_supply, 0);
787 	ag_flush(0,0,supply_out);
788 
789 	/* Flush the packet buffers, provided they are not empty and
790 	 * do not contain only the password.
791 	 */
792 	if (v12buf.n != v12buf.base
793 	    && (v12buf.n > v12buf.base+1
794 		|| v12buf.base->n_family != RIP_AF_AUTH))
795 		supply_write(&v12buf);
796 	if (v2buf.n != v2buf.base
797 	    && (v2buf.n > v2buf.base+1
798 		|| v2buf.base->n_family != RIP_AF_AUTH))
799 		supply_write(&v2buf);
800 
801 	/* If we sent nothing and this is an answer to a query, send
802 	 * an empty buffer.
803 	 */
804 	if (ws.npackets == 0
805 	    && (ws.state & WS_ST_QUERY))
806 		supply_write(&v12buf);
807 }
808 
809 
810 /* send all of the routing table or just do a flash update
811  */
812 void
813 rip_bcast(int flash)
814 {
815 #ifdef _HAVE_SIN_LEN
816 	static struct sockaddr_in dst = {sizeof(dst), AF_INET, 0, {0}, {0}};
817 #else
818 	static struct sockaddr_in dst = {AF_INET};
819 #endif
820 	struct interface *ifp;
821 	enum output_type type;
822 	int vers;
823 	struct timeval rtime;
824 
825 
826 	need_flash = 0;
827 	intvl_random(&rtime, MIN_WAITTIME, MAX_WAITTIME);
828 	no_flash = rtime;
829 	timevaladd(&no_flash, &now);
830 
831 	if (rip_sock < 0)
832 		return;
833 
834 	trace_act("send %s and inhibit dynamic updates for %.3f sec",
835 		  flash ? "dynamic update" : "all routes",
836 		  rtime.tv_sec + ((float)rtime.tv_usec)/1000000.0);
837 
838 	LIST_FOREACH(ifp, &ifnet, int_list) {
839 		/* Skip interfaces not doing RIP.
840 		 * Do try broken interfaces to see if they have healed.
841 		 */
842 		if (IS_RIP_OUT_OFF(ifp->int_state))
843 			continue;
844 
845 		/* skip turned off interfaces */
846 		if (!iff_up(ifp->int_if_flags))
847 			continue;
848 
849 		vers = (ifp->int_state & IS_NO_RIPV1_OUT) ? RIPv2 : RIPv1;
850 
851 		if (ifp->int_if_flags & IFF_BROADCAST) {
852 			/* ordinary, hardware interface */
853 			dst.sin_addr.s_addr = ifp->int_brdaddr;
854 
855 			if (vers == RIPv2
856 			    && !(ifp->int_state  & IS_NO_RIP_MCAST)) {
857 				type = OUT_MULTICAST;
858 			} else {
859 				type = OUT_BROADCAST;
860 			}
861 
862 		} else if (ifp->int_if_flags & IFF_POINTOPOINT) {
863 			/* point-to-point hardware interface */
864 			dst.sin_addr.s_addr = ifp->int_dstaddr;
865 			if (vers == RIPv2 &&
866 			    ifp->int_if_flags & IFF_MULTICAST &&
867 			    !(ifp->int_state  & IS_NO_RIP_MCAST)) {
868 				type = OUT_MULTICAST;
869 			} else {
870 				type = OUT_UNICAST;
871 			}
872 
873 		} else if (ifp->int_state & IS_REMOTE) {
874 			/* remote interface */
875 			dst.sin_addr.s_addr = ifp->int_addr;
876 			type = OUT_UNICAST;
877 
878 		} else {
879 			/* ATM, HIPPI, etc. */
880 			continue;
881 		}
882 
883 		supply(&dst, ifp, type, flash, vers, 1);
884 	}
885 
886 	update_seqno++;			/* all routes are up to date */
887 }
888 
889 
890 /* Ask for routes
891  * Do it only once to an interface, and not even after the interface
892  * was broken and recovered.
893  */
894 void
895 rip_query(void)
896 {
897 #ifdef _HAVE_SIN_LEN
898 	static struct sockaddr_in dst = {sizeof(dst), AF_INET, 0, {0}, {0}};
899 #else
900 	static struct sockaddr_in dst = {AF_INET};
901 #endif
902 	struct interface *ifp;
903 	struct rip buf;
904 	enum output_type type;
905 
906 
907 	if (rip_sock < 0)
908 		return;
909 
910 	memset(&buf, 0, sizeof(buf));
911 
912 	LIST_FOREACH(ifp, &ifnet, int_list) {
913 		/* Skip interfaces those already queried.
914 		 * Do not ask via interfaces through which we don't
915 		 * accept input.  Do not ask via interfaces that cannot
916 		 * send RIP packets.
917 		 * Do try broken interfaces to see if they have healed.
918 		 */
919 		if (IS_RIP_IN_OFF(ifp->int_state)
920 		    || ifp->int_query_time != NEVER)
921 			continue;
922 
923 		/* skip turned off interfaces */
924 		if (!iff_up(ifp->int_if_flags))
925 			continue;
926 
927 		buf.rip_vers = (ifp->int_state&IS_NO_RIPV1_OUT) ? RIPv2:RIPv1;
928 		buf.rip_cmd = RIPCMD_REQUEST;
929 		buf.rip_nets[0].n_family = RIP_AF_UNSPEC;
930 		buf.rip_nets[0].n_metric = htonl(HOPCNT_INFINITY);
931 
932 		/* Send a RIPv1 query only if allowed and if we will
933 		 * listen to RIPv1 routers.
934 		 */
935 		if ((ifp->int_state & IS_NO_RIPV1_OUT)
936 		    || (ifp->int_state & IS_NO_RIPV1_IN)) {
937 			buf.rip_vers = RIPv2;
938 		} else {
939 			buf.rip_vers = RIPv1;
940 		}
941 
942 		if (ifp->int_if_flags & IFF_BROADCAST) {
943 			/* ordinary, hardware interface */
944 			dst.sin_addr.s_addr = ifp->int_brdaddr;
945 
946 			/* Broadcast RIPv1 queries and RIPv2 queries
947 			 * when the hardware cannot multicast.
948 			 */
949 			if (buf.rip_vers == RIPv2
950 			    && (ifp->int_if_flags & IFF_MULTICAST)
951 			    && !(ifp->int_state  & IS_NO_RIP_MCAST)) {
952 				type = OUT_MULTICAST;
953 			} else {
954 				type = OUT_BROADCAST;
955 			}
956 
957 		} else if (ifp->int_if_flags & IFF_POINTOPOINT) {
958 			/* point-to-point hardware interface */
959 			dst.sin_addr.s_addr = ifp->int_dstaddr;
960 			type = OUT_UNICAST;
961 
962 		} else if (ifp->int_state & IS_REMOTE) {
963 			/* remote interface */
964 			dst.sin_addr.s_addr = ifp->int_addr;
965 			type = OUT_UNICAST;
966 
967 		} else {
968 			/* ATM, HIPPI, etc. */
969 			continue;
970 		}
971 
972 		ifp->int_query_time = now.tv_sec+SUPPLY_INTERVAL;
973 		if (output(type, &dst, ifp, &buf, sizeof(buf)) < 0)
974 			if_sick(ifp);
975 	}
976 }
977