xref: /freebsd/sbin/routed/output.c (revision b3e7694832e81d7a904a10f525f8797b753bf0d3)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1983, 1988, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include "defs.h"
33 
34 __RCSID("$FreeBSD$");
35 
36 
37 u_int update_seqno;
38 
39 
40 /* walk the tree of routes with this for output
41  */
42 static struct {
43 	struct sockaddr_in to;
44 	naddr	to_mask;
45 	naddr	to_net;
46 	naddr	to_std_mask;
47 	naddr	to_std_net;
48 	struct interface *ifp;		/* usually output interface */
49 	struct auth *a;
50 	char	metric;			/* adjust metrics by interface */
51 	int	npackets;
52 	int	gen_limit;
53 	u_int	state;
54 #define	    WS_ST_FLASH	    0x001	/* send only changed routes */
55 #define	    WS_ST_RIP2_ALL  0x002	/* send full featured RIPv2 */
56 #define	    WS_ST_AG	    0x004	/* ok to aggregate subnets */
57 #define	    WS_ST_SUPER_AG  0x008	/* ok to aggregate networks */
58 #define	    WS_ST_QUERY	    0x010	/* responding to a query */
59 #define	    WS_ST_TO_ON_NET 0x020	/* sending onto one of our nets */
60 #define	    WS_ST_DEFAULT   0x040	/* faking a default */
61 } ws;
62 
63 /* A buffer for what can be heard by both RIPv1 and RIPv2 listeners */
64 struct ws_buf v12buf;
65 static union pkt_buf ripv12_buf;
66 
67 /* Another for only RIPv2 listeners */
68 static struct ws_buf v2buf;
69 static union pkt_buf rip_v2_buf;
70 
71 
72 
73 void
74 bufinit(void)
75 {
76 	ripv12_buf.rip.rip_cmd = RIPCMD_RESPONSE;
77 	v12buf.buf = &ripv12_buf.rip;
78 	v12buf.base = &v12buf.buf->rip_nets[0];
79 
80 	rip_v2_buf.rip.rip_cmd = RIPCMD_RESPONSE;
81 	rip_v2_buf.rip.rip_vers = RIPv2;
82 	v2buf.buf = &rip_v2_buf.rip;
83 	v2buf.base = &v2buf.buf->rip_nets[0];
84 }
85 
86 
87 /* Send the contents of the global buffer via the non-multicast socket
88  */
89 int					/* <0 on failure */
90 output(enum output_type type,
91        struct sockaddr_in *dst,		/* send to here */
92        struct interface *ifp,
93        struct rip *buf,
94        int size)			/* this many bytes */
95 {
96 	struct sockaddr_in osin;
97 	int flags;
98 	const char *msg;
99 	int res;
100 	int soc;
101 	int serrno;
102 
103 	assert(ifp != NULL);
104 	osin = *dst;
105 	if (osin.sin_port == 0)
106 		osin.sin_port = htons(RIP_PORT);
107 #ifdef _HAVE_SIN_LEN
108 	if (osin.sin_len == 0)
109 		osin.sin_len = sizeof(osin);
110 #endif
111 
112 	soc = rip_sock;
113 	flags = 0;
114 
115 	switch (type) {
116 	case OUT_QUERY:
117 		msg = "Answer Query";
118 		if (soc < 0)
119 			soc = ifp->int_rip_sock;
120 		break;
121 	case OUT_UNICAST:
122 		msg = "Send";
123 		if (soc < 0)
124 			soc = ifp->int_rip_sock;
125 		flags = MSG_DONTROUTE;
126 		break;
127 	case OUT_BROADCAST:
128 		if (ifp->int_if_flags & IFF_POINTOPOINT) {
129 			msg = "Send";
130 		} else {
131 			msg = "Send bcast";
132 		}
133 		flags = MSG_DONTROUTE;
134 		break;
135 	case OUT_MULTICAST:
136 		if ((ifp->int_if_flags & (IFF_POINTOPOINT|IFF_MULTICAST)) ==
137 		    IFF_POINTOPOINT) {
138 			msg = "Send pt-to-pt";
139 		} else if (ifp->int_state & IS_DUP) {
140 			trace_act("abort multicast output via %s"
141 				  " with duplicate address",
142 				  ifp->int_name);
143 			return 0;
144 		} else {
145 			msg = "Send mcast";
146 			if (rip_sock_mcast != ifp) {
147 				struct ip_mreqn mreqn;
148 
149 				memset(&mreqn, 0, sizeof(struct ip_mreqn));
150 				mreqn.imr_ifindex = ifp->int_index;
151 				if (0 > setsockopt(rip_sock,
152 						   IPPROTO_IP,
153 						   IP_MULTICAST_IF,
154 						   &mreqn,
155 						   sizeof(mreqn))) {
156 					serrno = errno;
157 					LOGERR("setsockopt(rip_sock, "
158 					       "IP_MULTICAST_IF)");
159 					errno = serrno;
160 					ifp = NULL;
161 					return -1;
162 				}
163 				rip_sock_mcast = ifp;
164 			}
165 			osin.sin_addr.s_addr = htonl(INADDR_RIP_GROUP);
166 		}
167 		break;
168 
169 	case NO_OUT_MULTICAST:
170 	case NO_OUT_RIPV2:
171 	default:
172 #ifdef DEBUG
173 		abort();
174 #endif
175 		return -1;
176 	}
177 
178 	trace_rip(msg, "to", &osin, ifp, buf, size);
179 
180 	res = sendto(soc, buf, size, flags,
181 		     (struct sockaddr *)&osin, sizeof(osin));
182 	if (res < 0
183 	    && (ifp == NULL || !(ifp->int_state & IS_BROKE))) {
184 		serrno = errno;
185 		msglog("%s sendto(%s%s%s.%d): %s", msg,
186 		       ifp != NULL ? ifp->int_name : "",
187 		       ifp != NULL ? ", " : "",
188 		       inet_ntoa(osin.sin_addr),
189 		       ntohs(osin.sin_port),
190 		       strerror(errno));
191 		errno = serrno;
192 	}
193 
194 	return res;
195 }
196 
197 
198 /* Find the first key for a packet to send.
199  * Try for a key that is eligible and has not expired, but settle for
200  * the last key if they have all expired.
201  * If no key is ready yet, give up.
202  */
203 struct auth *
204 find_auth(struct interface *ifp)
205 {
206 	struct auth *ap, *res;
207 	int i;
208 
209 
210 	if (ifp == NULL)
211 		return 0;
212 
213 	res = NULL;
214 	ap = ifp->int_auth;
215 	for (i = 0; i < MAX_AUTH_KEYS; i++, ap++) {
216 		/* stop looking after the last key */
217 		if (ap->type == RIP_AUTH_NONE)
218 			break;
219 
220 		/* ignore keys that are not ready yet */
221 		if ((u_long)ap->start > (u_long)clk.tv_sec)
222 			continue;
223 
224 		if ((u_long)ap->end < (u_long)clk.tv_sec) {
225 			/* note best expired password as a fall-back */
226 			if (res == NULL || (u_long)ap->end > (u_long)res->end)
227 				res = ap;
228 			continue;
229 		}
230 
231 		/* note key with the best future */
232 		if (res == NULL || (u_long)res->end < (u_long)ap->end)
233 			res = ap;
234 	}
235 	return res;
236 }
237 
238 
239 void
240 clr_ws_buf(struct ws_buf *wb,
241 	   struct auth *ap)
242 {
243 	struct netauth *na;
244 
245 	wb->lim = wb->base + NETS_LEN;
246 	wb->n = wb->base;
247 	memset(wb->n, 0, NETS_LEN*sizeof(*wb->n));
248 
249 	/* (start to) install authentication if appropriate
250 	 */
251 	if (ap == NULL)
252 		return;
253 
254 	na = (struct netauth*)wb->n;
255 	if (ap->type == RIP_AUTH_PW) {
256 		na->a_family = RIP_AF_AUTH;
257 		na->a_type = RIP_AUTH_PW;
258 		memcpy(na->au.au_pw, ap->key, sizeof(na->au.au_pw));
259 		wb->n++;
260 
261 	} else if (ap->type ==  RIP_AUTH_MD5) {
262 		na->a_family = RIP_AF_AUTH;
263 		na->a_type = RIP_AUTH_MD5;
264 		na->au.a_md5.md5_keyid = ap->keyid;
265 		na->au.a_md5.md5_auth_len = RIP_AUTH_MD5_KEY_LEN;
266 		na->au.a_md5.md5_seqno = htonl(clk.tv_sec);
267 		wb->n++;
268 		wb->lim--;		/* make room for trailer */
269 	}
270 }
271 
272 
273 void
274 end_md5_auth(struct ws_buf *wb,
275 	     struct auth *ap)
276 {
277 	struct netauth *na, *na2;
278 	MD5_CTX md5_ctx;
279 	int len;
280 
281 
282 	na = (struct netauth*)wb->base;
283 	na2 = (struct netauth*)wb->n;
284 	len = (char *)na2-(char *)wb->buf;
285 	na2->a_family = RIP_AF_AUTH;
286 	na2->a_type = htons(1);
287 	na->au.a_md5.md5_pkt_len = htons(len);
288 	MD5Init(&md5_ctx);
289 	MD5Update(&md5_ctx, (u_char *)wb->buf, len + RIP_AUTH_MD5_HASH_XTRA);
290 	MD5Update(&md5_ctx, ap->key, RIP_AUTH_MD5_KEY_LEN);
291 	MD5Final(na2->au.au_pw, &md5_ctx);
292 	wb->n++;
293 }
294 
295 
296 /* Send the buffer
297  */
298 static void
299 supply_write(struct ws_buf *wb)
300 {
301 	/* Output multicast only if legal.
302 	 * If we would multicast and it would be illegal, then discard the
303 	 * packet.
304 	 */
305 	switch (wb->type) {
306 	case NO_OUT_MULTICAST:
307 		trace_pkt("skip multicast to %s because impossible",
308 			  naddr_ntoa(ws.to.sin_addr.s_addr));
309 		break;
310 	case NO_OUT_RIPV2:
311 		break;
312 	default:
313 		if (ws.a != NULL && ws.a->type == RIP_AUTH_MD5)
314 			end_md5_auth(wb,ws.a);
315 		if (output(wb->type, &ws.to, ws.ifp, wb->buf,
316 			   ((char *)wb->n - (char*)wb->buf)) < 0
317 		    && ws.ifp != NULL)
318 			if_sick(ws.ifp);
319 		ws.npackets++;
320 		break;
321 	}
322 
323 	clr_ws_buf(wb,ws.a);
324 }
325 
326 
327 /* put an entry into the packet
328  */
329 static void
330 supply_out(struct ag_info *ag)
331 {
332 	int i;
333 	naddr mask, v1_mask, dst_h, ddst_h = 0;
334 	struct ws_buf *wb;
335 
336 
337 	/* Skip this route if doing a flash update and it and the routes
338 	 * it aggregates have not changed recently.
339 	 */
340 	if (ag->ag_seqno < update_seqno
341 	    && (ws.state & WS_ST_FLASH))
342 		return;
343 
344 	dst_h = ag->ag_dst_h;
345 	mask = ag->ag_mask;
346 	v1_mask = ripv1_mask_host(htonl(dst_h),
347 				  (ws.state & WS_ST_TO_ON_NET) ? ws.ifp : 0);
348 	i = 0;
349 
350 	/* If we are sending RIPv2 packets that cannot (or must not) be
351 	 * heard by RIPv1 listeners, do not worry about sub- or supernets.
352 	 * Subnets (from other networks) can only be sent via multicast.
353 	 * A pair of subnet routes might have been promoted so that they
354 	 * are legal to send by RIPv1.
355 	 * If RIPv1 is off, use the multicast buffer.
356 	 */
357 	if ((ws.state & WS_ST_RIP2_ALL)
358 	    || ((ag->ag_state & AGS_RIPV2) && v1_mask != mask)) {
359 		/* use the RIPv2-only buffer */
360 		wb = &v2buf;
361 
362 	} else {
363 		/* use the RIPv1-or-RIPv2 buffer */
364 		wb = &v12buf;
365 
366 		/* Convert supernet route into corresponding set of network
367 		 * routes for RIPv1, but leave non-contiguous netmasks
368 		 * to ag_check().
369 		 */
370 		if (v1_mask > mask
371 		    && mask + (mask & -mask) == 0) {
372 			ddst_h = v1_mask & -v1_mask;
373 			i = (v1_mask & ~mask)/ddst_h;
374 
375 			if (i > ws.gen_limit) {
376 				/* Punt if we would have to generate an
377 				 * unreasonable number of routes.
378 				 */
379 				if (TRACECONTENTS)
380 					trace_misc("sending %s-->%s as 1"
381 						   " instead of %d routes",
382 						   addrname(htonl(dst_h), mask,
383 							1),
384 						   naddr_ntoa(ws.to.sin_addr
385 							.s_addr),
386 						   i+1);
387 				i = 0;
388 
389 			} else {
390 				mask = v1_mask;
391 				ws.gen_limit -= i;
392 			}
393 		}
394 	}
395 
396 	do {
397 		wb->n->n_family = RIP_AF_INET;
398 		wb->n->n_dst = htonl(dst_h);
399 		/* If the route is from router-discovery or we are
400 		 * shutting down, admit only a bad metric.
401 		 */
402 		wb->n->n_metric = ((stopint || ag->ag_metric < 1)
403 				   ? HOPCNT_INFINITY
404 				   : ag->ag_metric);
405 		wb->n->n_metric = htonl(wb->n->n_metric);
406 		/* Any non-zero bits in the supposedly unused RIPv1 fields
407 		 * cause the old `routed` to ignore the route.
408 		 * That means the mask and so forth cannot be sent
409 		 * in the hybrid RIPv1/RIPv2 mode.
410 		 */
411 		if (ws.state & WS_ST_RIP2_ALL) {
412 			if (ag->ag_nhop != 0
413 			    && ((ws.state & WS_ST_QUERY)
414 				|| (ag->ag_nhop != ws.ifp->int_addr
415 				    && on_net(ag->ag_nhop,
416 					      ws.ifp->int_net,
417 					      ws.ifp->int_mask))))
418 				wb->n->n_nhop = ag->ag_nhop;
419 			wb->n->n_mask = htonl(mask);
420 			wb->n->n_tag = ag->ag_tag;
421 		}
422 		dst_h += ddst_h;
423 
424 		if (++wb->n >= wb->lim)
425 			supply_write(wb);
426 	} while (i-- != 0);
427 }
428 
429 
430 /* supply one route from the table
431  */
432 /* ARGSUSED */
433 static int
434 walk_supply(struct radix_node *rn,
435 	    struct walkarg *argp UNUSED)
436 {
437 #define RT ((struct rt_entry *)rn)
438 	u_short ags;
439 	char metric, pref;
440 	naddr dst, nhop;
441 	struct rt_spare *rts;
442 	int i;
443 
444 
445 	/* Do not advertise external remote interfaces or passive interfaces.
446 	 */
447 	if ((RT->rt_state & RS_IF)
448 	    && RT->rt_ifp != 0
449 	    && (RT->rt_ifp->int_state & IS_PASSIVE)
450 	    && !(RT->rt_state & RS_MHOME))
451 		return 0;
452 
453 	/* If being quiet about our ability to forward, then
454 	 * do not say anything unless responding to a query,
455 	 * except about our main interface.
456 	 */
457 	if (!supplier && !(ws.state & WS_ST_QUERY)
458 	    && !(RT->rt_state & RS_MHOME))
459 		return 0;
460 
461 	dst = RT->rt_dst;
462 
463 	/* do not collide with the fake default route */
464 	if (dst == RIP_DEFAULT
465 	    && (ws.state & WS_ST_DEFAULT))
466 		return 0;
467 
468 	if (RT->rt_state & RS_NET_SYN) {
469 		if (RT->rt_state & RS_NET_INT) {
470 			/* Do not send manual synthetic network routes
471 			 * into the subnet.
472 			 */
473 			if (on_net(ws.to.sin_addr.s_addr,
474 				   ntohl(dst), RT->rt_mask))
475 				return 0;
476 
477 		} else {
478 			/* Do not send automatic synthetic network routes
479 			 * if they are not needed because no RIPv1 listeners
480 			 * can hear them.
481 			 */
482 			if (ws.state & WS_ST_RIP2_ALL)
483 				return 0;
484 
485 			/* Do not send automatic synthetic network routes to
486 			 * the real subnet.
487 			 */
488 			if (on_net(ws.to.sin_addr.s_addr,
489 				   ntohl(dst), RT->rt_mask))
490 				return 0;
491 		}
492 		nhop = 0;
493 
494 	} else {
495 		/* Advertise the next hop if this is not a route for one
496 		 * of our interfaces and the next hop is on the same
497 		 * network as the target.
498 		 * The final determination is made by supply_out().
499 		 */
500 		if (!(RT->rt_state & RS_IF)
501 		    && RT->rt_gate != myaddr
502 		    && RT->rt_gate != loopaddr)
503 			nhop = RT->rt_gate;
504 		else
505 			nhop = 0;
506 	}
507 
508 	metric = RT->rt_metric;
509 	ags = 0;
510 
511 	if (RT->rt_state & RS_MHOME) {
512 		/* retain host route of multi-homed servers */
513 		;
514 
515 	} else if (RT_ISHOST(RT)) {
516 		/* We should always suppress (into existing network routes)
517 		 * the host routes for the local end of our point-to-point
518 		 * links.
519 		 * If we are suppressing host routes in general, then do so.
520 		 * Avoid advertising host routes onto their own network,
521 		 * where they should be handled by proxy-ARP.
522 		 */
523 		if ((RT->rt_state & RS_LOCAL)
524 		    || ridhosts
525 		    || on_net(dst, ws.to_net, ws.to_mask))
526 			ags |= AGS_SUPPRESS;
527 
528 		/* Aggregate stray host routes into network routes if allowed.
529 		 * We cannot aggregate host routes into small network routes
530 		 * without confusing RIPv1 listeners into thinking the
531 		 * network routes are host routes.
532 		 */
533 		if ((ws.state & WS_ST_AG) && (ws.state & WS_ST_RIP2_ALL))
534 			ags |= AGS_AGGREGATE;
535 
536 	} else {
537 		/* Always suppress network routes into other, existing
538 		 * network routes
539 		 */
540 		ags |= AGS_SUPPRESS;
541 
542 		/* Generate supernets if allowed.
543 		 * If we can be heard by RIPv1 systems, we will
544 		 * later convert back to ordinary nets.
545 		 * This unifies dealing with received supernets.
546 		 */
547 		if ((ws.state & WS_ST_AG)
548 		    && ((RT->rt_state & RS_SUBNET)
549 			|| (ws.state & WS_ST_SUPER_AG)))
550 			ags |= AGS_AGGREGATE;
551 	}
552 
553 	/* Do not send RIPv1 advertisements of subnets to other
554 	 * networks. If possible, multicast them by RIPv2.
555 	 */
556 	if ((RT->rt_state & RS_SUBNET)
557 	    && !(ws.state & WS_ST_RIP2_ALL)
558 	    && !on_net(dst, ws.to_std_net, ws.to_std_mask))
559 		ags |= AGS_RIPV2 | AGS_AGGREGATE;
560 
561 
562 	/* Do not send a route back to where it came from, except in
563 	 * response to a query.  This is "split-horizon".  That means not
564 	 * advertising back to the same network	and so via the same interface.
565 	 *
566 	 * We want to suppress routes that might have been fragmented
567 	 * from this route by a RIPv1 router and sent back to us, and so we
568 	 * cannot forget this route here.  Let the split-horizon route
569 	 * suppress the fragmented routes and then itself be forgotten.
570 	 *
571 	 * Include the routes for both ends of point-to-point interfaces
572 	 * among those suppressed by split-horizon, since the other side
573 	 * should knows them as well as we do.
574 	 *
575 	 * Notice spare routes with the same metric that we are about to
576 	 * advertise, to split the horizon on redundant, inactive paths.
577 	 *
578 	 * Do not suppress advertisements of interface-related addresses on
579 	 * non-point-to-point interfaces.  This ensures that we have something
580 	 * to say every 30 seconds to help detect broken Ethernets or
581 	 * other interfaces where one packet every 30 seconds costs nothing.
582 	 */
583 	if (ws.ifp != NULL
584 	    && !(ws.state & WS_ST_QUERY)
585 	    && (ws.state & WS_ST_TO_ON_NET)
586 	    && (!(RT->rt_state & RS_IF)
587 		|| ws.ifp->int_if_flags & IFF_POINTOPOINT)) {
588 		for (rts = RT->rt_spares, i = NUM_SPARES; i != 0; i--, rts++) {
589 			if (rts->rts_metric > metric
590 			    || rts->rts_ifp != ws.ifp)
591 				continue;
592 
593 			/* If we do not mark the route with AGS_SPLIT_HZ here,
594 			 * it will be poisoned-reverse, or advertised back
595 			 * toward its source with an infinite metric.
596 			 * If we have recently advertised the route with a
597 			 * better metric than we now have, then we should
598 			 * poison-reverse the route before suppressing it for
599 			 * split-horizon.
600 			 *
601 			 * In almost all cases, if there is no spare for the
602 			 * route then it is either old and dead or a brand
603 			 * new route. If it is brand new, there is no need
604 			 * for poison-reverse. If it is old and dead, it
605 			 * is already poisoned.
606 			 */
607 			if (RT->rt_poison_time < now_expire
608 			    || RT->rt_poison_metric >= metric
609 			    || RT->rt_spares[1].rts_gate == 0) {
610 				ags |= AGS_SPLIT_HZ;
611 				ags &= ~AGS_SUPPRESS;
612 			}
613 			metric = HOPCNT_INFINITY;
614 			break;
615 		}
616 	}
617 
618 	/* Keep track of the best metric with which the
619 	 * route has been advertised recently.
620 	 */
621 	if (RT->rt_poison_metric >= metric
622 	    || RT->rt_poison_time < now_expire) {
623 		RT->rt_poison_time = now.tv_sec;
624 		RT->rt_poison_metric = metric;
625 	}
626 
627 	/* Adjust the outgoing metric by the cost of the link.
628 	 * Avoid aggregation when a route is counting to infinity.
629 	 */
630 	pref = RT->rt_poison_metric + ws.metric;
631 	metric += ws.metric;
632 
633 	/* Do not advertise stable routes that will be ignored,
634 	 * unless we are answering a query.
635 	 * If the route recently was advertised with a metric that
636 	 * would have been less than infinity through this interface,
637 	 * we need to continue to advertise it in order to poison it.
638 	 */
639 	if (metric >= HOPCNT_INFINITY) {
640 		if (!(ws.state & WS_ST_QUERY)
641 		    && (pref >= HOPCNT_INFINITY
642 			|| RT->rt_poison_time < now_garbage))
643 			return 0;
644 
645 		metric = HOPCNT_INFINITY;
646 	}
647 
648 	ag_check(dst, RT->rt_mask, 0, nhop, metric, pref,
649 		 RT->rt_seqno, RT->rt_tag, ags, supply_out);
650 	return 0;
651 #undef RT
652 }
653 
654 
655 /* Supply dst with the contents of the routing tables.
656  * If this won't fit in one packet, chop it up into several.
657  */
658 void
659 supply(struct sockaddr_in *dst,
660        struct interface *ifp,		/* output interface */
661        enum output_type type,
662        int flash,			/* 1=flash update */
663        int vers,			/* RIP version */
664        int passwd_ok)			/* OK to include cleartext password */
665 {
666 	struct rt_entry *rt;
667 	int def_metric;
668 
669 	ws.state = 0;
670 	ws.gen_limit = 1024;
671 
672 	ws.to = *dst;
673 	ws.to_std_mask = std_mask(ws.to.sin_addr.s_addr);
674 	ws.to_std_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_std_mask;
675 
676 	if (ifp != NULL) {
677 		ws.to_mask = ifp->int_mask;
678 		ws.to_net = ifp->int_net;
679 		if (on_net(ws.to.sin_addr.s_addr, ws.to_net, ws.to_mask))
680 			ws.state |= WS_ST_TO_ON_NET;
681 
682 	} else {
683 		ws.to_mask = ripv1_mask_net(ws.to.sin_addr.s_addr, 0);
684 		ws.to_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_mask;
685 		rt = rtfind(dst->sin_addr.s_addr);
686 		if (rt)
687 			ifp = rt->rt_ifp;
688 	}
689 
690 	ws.npackets = 0;
691 	if (flash)
692 		ws.state |= WS_ST_FLASH;
693 
694 	if ((ws.ifp = ifp) == NULL) {
695 		ws.metric = 1;
696 	} else {
697 		/* Adjust the advertised metric by the outgoing interface
698 		 * metric.
699 		 */
700 		ws.metric = ifp->int_metric + 1 + ifp->int_adj_outmetric;
701 	}
702 
703 	ripv12_buf.rip.rip_vers = vers;
704 
705 	switch (type) {
706 	case OUT_MULTICAST:
707 		if (ifp != NULL && ifp->int_if_flags & IFF_MULTICAST)
708 			v2buf.type = OUT_MULTICAST;
709 		else
710 			v2buf.type = NO_OUT_MULTICAST;
711 		v12buf.type = OUT_BROADCAST;
712 		break;
713 
714 	case OUT_QUERY:
715 		ws.state |= WS_ST_QUERY;
716 		/* FALLTHROUGH */
717 	case OUT_BROADCAST:
718 	case OUT_UNICAST:
719 		v2buf.type = (vers == RIPv2) ? type : NO_OUT_RIPV2;
720 		v12buf.type = type;
721 		break;
722 
723 	case NO_OUT_MULTICAST:
724 	case NO_OUT_RIPV2:
725 		break;			/* no output */
726 	}
727 
728 	if (vers == RIPv2) {
729 		/* full RIPv2 only if cannot be heard by RIPv1 listeners */
730 		if (type != OUT_BROADCAST)
731 			ws.state |= WS_ST_RIP2_ALL;
732 		if ((ws.state & WS_ST_QUERY)
733 		    || !(ws.state & WS_ST_TO_ON_NET)) {
734 			ws.state |= (WS_ST_AG | WS_ST_SUPER_AG);
735 		} else if (ifp == NULL || !(ifp->int_state & IS_NO_AG)) {
736 			ws.state |= WS_ST_AG;
737 			if (type != OUT_BROADCAST
738 			    && (ifp == NULL
739 				|| !(ifp->int_state & IS_NO_SUPER_AG)))
740 				ws.state |= WS_ST_SUPER_AG;
741 		}
742 	}
743 
744 	ws.a = (vers == RIPv2) ? find_auth(ifp) : 0;
745 	if (!passwd_ok && ws.a != NULL && ws.a->type == RIP_AUTH_PW)
746 		ws.a = NULL;
747 	clr_ws_buf(&v12buf,ws.a);
748 	clr_ws_buf(&v2buf,ws.a);
749 
750 	/*  Fake a default route if asked and if there is not already
751 	 * a better, real default route.
752 	 */
753 	if (supplier && ifp && (def_metric = ifp->int_d_metric) != 0) {
754 		if ((rt = rtget(RIP_DEFAULT, 0)) == NULL
755 		    || rt->rt_metric+ws.metric >= def_metric) {
756 			ws.state |= WS_ST_DEFAULT;
757 			ag_check(0, 0, 0, 0, def_metric, def_metric,
758 				 0, 0, 0, supply_out);
759 		} else {
760 			def_metric = rt->rt_metric+ws.metric;
761 		}
762 
763 		/* If both RIPv2 and the poor-man's router discovery
764 		 * kludge are on, arrange to advertise an extra
765 		 * default route via RIPv1.
766 		 */
767 		if ((ws.state & WS_ST_RIP2_ALL)
768 		    && (ifp->int_state & IS_PM_RDISC)) {
769 			ripv12_buf.rip.rip_vers = RIPv1;
770 			v12buf.n->n_family = RIP_AF_INET;
771 			v12buf.n->n_dst = htonl(RIP_DEFAULT);
772 			v12buf.n->n_metric = htonl(def_metric);
773 			v12buf.n++;
774 		}
775 	}
776 
777 	(void)rn_walktree(rhead, walk_supply, 0);
778 	ag_flush(0,0,supply_out);
779 
780 	/* Flush the packet buffers, provided they are not empty and
781 	 * do not contain only the password.
782 	 */
783 	if (v12buf.n != v12buf.base
784 	    && (v12buf.n > v12buf.base+1
785 		|| v12buf.base->n_family != RIP_AF_AUTH))
786 		supply_write(&v12buf);
787 	if (v2buf.n != v2buf.base
788 	    && (v2buf.n > v2buf.base+1
789 		|| v2buf.base->n_family != RIP_AF_AUTH))
790 		supply_write(&v2buf);
791 
792 	/* If we sent nothing and this is an answer to a query, send
793 	 * an empty buffer.
794 	 */
795 	if (ws.npackets == 0
796 	    && (ws.state & WS_ST_QUERY))
797 		supply_write(&v12buf);
798 }
799 
800 
801 /* send all of the routing table or just do a flash update
802  */
803 void
804 rip_bcast(int flash)
805 {
806 #ifdef _HAVE_SIN_LEN
807 	static struct sockaddr_in dst = {sizeof(dst), AF_INET, 0, {0}, {0}};
808 #else
809 	static struct sockaddr_in dst = {AF_INET};
810 #endif
811 	struct interface *ifp;
812 	enum output_type type;
813 	int vers;
814 	struct timeval rtime;
815 
816 
817 	need_flash = 0;
818 	intvl_random(&rtime, MIN_WAITTIME, MAX_WAITTIME);
819 	no_flash = rtime;
820 	timevaladd(&no_flash, &now);
821 
822 	if (rip_sock < 0)
823 		return;
824 
825 	trace_act("send %s and inhibit dynamic updates for %.3f sec",
826 		  flash ? "dynamic update" : "all routes",
827 		  rtime.tv_sec + ((float)rtime.tv_usec)/1000000.0);
828 
829 	LIST_FOREACH(ifp, &ifnet, int_list) {
830 		/* Skip interfaces not doing RIP.
831 		 * Do try broken interfaces to see if they have healed.
832 		 */
833 		if (IS_RIP_OUT_OFF(ifp->int_state))
834 			continue;
835 
836 		/* skip turned off interfaces */
837 		if (!iff_up(ifp->int_if_flags))
838 			continue;
839 
840 		vers = (ifp->int_state & IS_NO_RIPV1_OUT) ? RIPv2 : RIPv1;
841 
842 		if (ifp->int_if_flags & IFF_BROADCAST) {
843 			/* ordinary, hardware interface */
844 			dst.sin_addr.s_addr = ifp->int_brdaddr;
845 
846 			if (vers == RIPv2
847 			    && !(ifp->int_state  & IS_NO_RIP_MCAST)) {
848 				type = OUT_MULTICAST;
849 			} else {
850 				type = OUT_BROADCAST;
851 			}
852 
853 		} else if (ifp->int_if_flags & IFF_POINTOPOINT) {
854 			/* point-to-point hardware interface */
855 			dst.sin_addr.s_addr = ifp->int_dstaddr;
856 			if (vers == RIPv2 &&
857 			    ifp->int_if_flags & IFF_MULTICAST &&
858 			    !(ifp->int_state  & IS_NO_RIP_MCAST)) {
859 				type = OUT_MULTICAST;
860 			} else {
861 				type = OUT_UNICAST;
862 			}
863 
864 		} else if (ifp->int_state & IS_REMOTE) {
865 			/* remote interface */
866 			dst.sin_addr.s_addr = ifp->int_addr;
867 			type = OUT_UNICAST;
868 
869 		} else {
870 			/* ATM, HIPPI, etc. */
871 			continue;
872 		}
873 
874 		supply(&dst, ifp, type, flash, vers, 1);
875 	}
876 
877 	update_seqno++;			/* all routes are up to date */
878 }
879 
880 
881 /* Ask for routes
882  * Do it only once to an interface, and not even after the interface
883  * was broken and recovered.
884  */
885 void
886 rip_query(void)
887 {
888 #ifdef _HAVE_SIN_LEN
889 	static struct sockaddr_in dst = {sizeof(dst), AF_INET, 0, {0}, {0}};
890 #else
891 	static struct sockaddr_in dst = {AF_INET};
892 #endif
893 	struct interface *ifp;
894 	struct rip buf;
895 	enum output_type type;
896 
897 
898 	if (rip_sock < 0)
899 		return;
900 
901 	memset(&buf, 0, sizeof(buf));
902 
903 	LIST_FOREACH(ifp, &ifnet, int_list) {
904 		/* Skip interfaces those already queried.
905 		 * Do not ask via interfaces through which we don't
906 		 * accept input.  Do not ask via interfaces that cannot
907 		 * send RIP packets.
908 		 * Do try broken interfaces to see if they have healed.
909 		 */
910 		if (IS_RIP_IN_OFF(ifp->int_state)
911 		    || ifp->int_query_time != NEVER)
912 			continue;
913 
914 		/* skip turned off interfaces */
915 		if (!iff_up(ifp->int_if_flags))
916 			continue;
917 
918 		buf.rip_vers = (ifp->int_state&IS_NO_RIPV1_OUT) ? RIPv2:RIPv1;
919 		buf.rip_cmd = RIPCMD_REQUEST;
920 		buf.rip_nets[0].n_family = RIP_AF_UNSPEC;
921 		buf.rip_nets[0].n_metric = htonl(HOPCNT_INFINITY);
922 
923 		/* Send a RIPv1 query only if allowed and if we will
924 		 * listen to RIPv1 routers.
925 		 */
926 		if ((ifp->int_state & IS_NO_RIPV1_OUT)
927 		    || (ifp->int_state & IS_NO_RIPV1_IN)) {
928 			buf.rip_vers = RIPv2;
929 		} else {
930 			buf.rip_vers = RIPv1;
931 		}
932 
933 		if (ifp->int_if_flags & IFF_BROADCAST) {
934 			/* ordinary, hardware interface */
935 			dst.sin_addr.s_addr = ifp->int_brdaddr;
936 
937 			/* Broadcast RIPv1 queries and RIPv2 queries
938 			 * when the hardware cannot multicast.
939 			 */
940 			if (buf.rip_vers == RIPv2
941 			    && (ifp->int_if_flags & IFF_MULTICAST)
942 			    && !(ifp->int_state  & IS_NO_RIP_MCAST)) {
943 				type = OUT_MULTICAST;
944 			} else {
945 				type = OUT_BROADCAST;
946 			}
947 
948 		} else if (ifp->int_if_flags & IFF_POINTOPOINT) {
949 			/* point-to-point hardware interface */
950 			dst.sin_addr.s_addr = ifp->int_dstaddr;
951 			type = OUT_UNICAST;
952 
953 		} else if (ifp->int_state & IS_REMOTE) {
954 			/* remote interface */
955 			dst.sin_addr.s_addr = ifp->int_addr;
956 			type = OUT_UNICAST;
957 
958 		} else {
959 			/* ATM, HIPPI, etc. */
960 			continue;
961 		}
962 
963 		ifp->int_query_time = now.tv_sec+SUPPLY_INTERVAL;
964 		if (output(type, &dst, ifp, &buf, sizeof(buf)) < 0)
965 			if_sick(ifp);
966 	}
967 }
968