xref: /freebsd/sbin/routed/output.c (revision cc68614da8232d8baaca0ae0d0dd8f890f06623e)
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  * $FreeBSD$
32  */
33 
34 #include "defs.h"
35 
36 __RCSID("$FreeBSD$");
37 
38 
39 u_int update_seqno;
40 
41 
42 /* walk the tree of routes with this for output
43  */
44 static struct {
45 	struct sockaddr_in to;
46 	naddr	to_mask;
47 	naddr	to_net;
48 	naddr	to_std_mask;
49 	naddr	to_std_net;
50 	struct interface *ifp;		/* usually output interface */
51 	struct auth *a;
52 	char	metric;			/* adjust metrics by interface */
53 	int	npackets;
54 	int	gen_limit;
55 	u_int	state;
56 #define	    WS_ST_FLASH	    0x001	/* send only changed routes */
57 #define	    WS_ST_RIP2_ALL  0x002	/* send full featured RIPv2 */
58 #define	    WS_ST_AG	    0x004	/* ok to aggregate subnets */
59 #define	    WS_ST_SUPER_AG  0x008	/* ok to aggregate networks */
60 #define	    WS_ST_QUERY	    0x010	/* responding to a query */
61 #define	    WS_ST_TO_ON_NET 0x020	/* sending onto one of our nets */
62 #define	    WS_ST_DEFAULT   0x040	/* faking a default */
63 } ws;
64 
65 /* A buffer for what can be heard by both RIPv1 and RIPv2 listeners */
66 struct ws_buf v12buf;
67 static union pkt_buf ripv12_buf;
68 
69 /* Another for only RIPv2 listeners */
70 static struct ws_buf v2buf;
71 static union pkt_buf rip_v2_buf;
72 
73 
74 
75 void
76 bufinit(void)
77 {
78 	ripv12_buf.rip.rip_cmd = RIPCMD_RESPONSE;
79 	v12buf.buf = &ripv12_buf.rip;
80 	v12buf.base = &v12buf.buf->rip_nets[0];
81 
82 	rip_v2_buf.rip.rip_cmd = RIPCMD_RESPONSE;
83 	rip_v2_buf.rip.rip_vers = RIPv2;
84 	v2buf.buf = &rip_v2_buf.rip;
85 	v2buf.base = &v2buf.buf->rip_nets[0];
86 }
87 
88 
89 /* Send the contents of the global buffer via the non-multicast socket
90  */
91 int					/* <0 on failure */
92 output(enum output_type type,
93        struct sockaddr_in *dst,		/* send to here */
94        struct interface *ifp,
95        struct rip *buf,
96        int size)			/* this many bytes */
97 {
98 	struct sockaddr_in osin;
99 	int flags;
100 	const char *msg;
101 	int res;
102 	int soc;
103 	int serrno;
104 
105 	assert(ifp != NULL);
106 	osin = *dst;
107 	if (osin.sin_port == 0)
108 		osin.sin_port = htons(RIP_PORT);
109 #ifdef _HAVE_SIN_LEN
110 	if (osin.sin_len == 0)
111 		osin.sin_len = sizeof(osin);
112 #endif
113 
114 	soc = rip_sock;
115 	flags = 0;
116 
117 	switch (type) {
118 	case OUT_QUERY:
119 		msg = "Answer Query";
120 		if (soc < 0)
121 			soc = ifp->int_rip_sock;
122 		break;
123 	case OUT_UNICAST:
124 		msg = "Send";
125 		if (soc < 0)
126 			soc = ifp->int_rip_sock;
127 		flags = MSG_DONTROUTE;
128 		break;
129 	case OUT_BROADCAST:
130 		if (ifp->int_if_flags & IFF_POINTOPOINT) {
131 			msg = "Send";
132 		} else {
133 			msg = "Send bcast";
134 		}
135 		flags = MSG_DONTROUTE;
136 		break;
137 	case OUT_MULTICAST:
138 		if ((ifp->int_if_flags & (IFF_POINTOPOINT|IFF_MULTICAST)) ==
139 		    IFF_POINTOPOINT) {
140 			msg = "Send pt-to-pt";
141 		} else if (ifp->int_state & IS_DUP) {
142 			trace_act("abort multicast output via %s"
143 				  " with duplicate address",
144 				  ifp->int_name);
145 			return 0;
146 		} else {
147 			msg = "Send mcast";
148 			if (rip_sock_mcast != ifp) {
149 				struct ip_mreqn mreqn;
150 
151 				memset(&mreqn, 0, sizeof(struct ip_mreqn));
152 				mreqn.imr_ifindex = ifp->int_index;
153 				if (0 > setsockopt(rip_sock,
154 						   IPPROTO_IP,
155 						   IP_MULTICAST_IF,
156 						   &mreqn,
157 						   sizeof(mreqn))) {
158 					serrno = errno;
159 					LOGERR("setsockopt(rip_sock, "
160 					       "IP_MULTICAST_IF)");
161 					errno = serrno;
162 					ifp = NULL;
163 					return -1;
164 				}
165 				rip_sock_mcast = ifp;
166 			}
167 			osin.sin_addr.s_addr = htonl(INADDR_RIP_GROUP);
168 		}
169 		break;
170 
171 	case NO_OUT_MULTICAST:
172 	case NO_OUT_RIPV2:
173 	default:
174 #ifdef DEBUG
175 		abort();
176 #endif
177 		return -1;
178 	}
179 
180 	trace_rip(msg, "to", &osin, ifp, buf, size);
181 
182 	res = sendto(soc, buf, size, flags,
183 		     (struct sockaddr *)&osin, sizeof(osin));
184 	if (res < 0
185 	    && (ifp == NULL || !(ifp->int_state & IS_BROKE))) {
186 		serrno = errno;
187 		msglog("%s sendto(%s%s%s.%d): %s", msg,
188 		       ifp != NULL ? ifp->int_name : "",
189 		       ifp != NULL ? ", " : "",
190 		       inet_ntoa(osin.sin_addr),
191 		       ntohs(osin.sin_port),
192 		       strerror(errno));
193 		errno = serrno;
194 	}
195 
196 	return res;
197 }
198 
199 
200 /* Find the first key for a packet to send.
201  * Try for a key that is eligible and has not expired, but settle for
202  * the last key if they have all expired.
203  * If no key is ready yet, give up.
204  */
205 struct auth *
206 find_auth(struct interface *ifp)
207 {
208 	struct auth *ap, *res;
209 	int i;
210 
211 
212 	if (ifp == NULL)
213 		return 0;
214 
215 	res = NULL;
216 	ap = ifp->int_auth;
217 	for (i = 0; i < MAX_AUTH_KEYS; i++, ap++) {
218 		/* stop looking after the last key */
219 		if (ap->type == RIP_AUTH_NONE)
220 			break;
221 
222 		/* ignore keys that are not ready yet */
223 		if ((u_long)ap->start > (u_long)clk.tv_sec)
224 			continue;
225 
226 		if ((u_long)ap->end < (u_long)clk.tv_sec) {
227 			/* note best expired password as a fall-back */
228 			if (res == NULL || (u_long)ap->end > (u_long)res->end)
229 				res = ap;
230 			continue;
231 		}
232 
233 		/* note key with the best future */
234 		if (res == NULL || (u_long)res->end < (u_long)ap->end)
235 			res = ap;
236 	}
237 	return res;
238 }
239 
240 
241 void
242 clr_ws_buf(struct ws_buf *wb,
243 	   struct auth *ap)
244 {
245 	struct netauth *na;
246 
247 	wb->lim = wb->base + NETS_LEN;
248 	wb->n = wb->base;
249 	memset(wb->n, 0, NETS_LEN*sizeof(*wb->n));
250 
251 	/* (start to) install authentication if appropriate
252 	 */
253 	if (ap == NULL)
254 		return;
255 
256 	na = (struct netauth*)wb->n;
257 	if (ap->type == RIP_AUTH_PW) {
258 		na->a_family = RIP_AF_AUTH;
259 		na->a_type = RIP_AUTH_PW;
260 		memcpy(na->au.au_pw, ap->key, sizeof(na->au.au_pw));
261 		wb->n++;
262 
263 	} else if (ap->type ==  RIP_AUTH_MD5) {
264 		na->a_family = RIP_AF_AUTH;
265 		na->a_type = RIP_AUTH_MD5;
266 		na->au.a_md5.md5_keyid = ap->keyid;
267 		na->au.a_md5.md5_auth_len = RIP_AUTH_MD5_KEY_LEN;
268 		na->au.a_md5.md5_seqno = htonl(clk.tv_sec);
269 		wb->n++;
270 		wb->lim--;		/* make room for trailer */
271 	}
272 }
273 
274 
275 void
276 end_md5_auth(struct ws_buf *wb,
277 	     struct auth *ap)
278 {
279 	struct netauth *na, *na2;
280 	MD5_CTX md5_ctx;
281 	int len;
282 
283 
284 	na = (struct netauth*)wb->base;
285 	na2 = (struct netauth*)wb->n;
286 	len = (char *)na2-(char *)wb->buf;
287 	na2->a_family = RIP_AF_AUTH;
288 	na2->a_type = htons(1);
289 	na->au.a_md5.md5_pkt_len = htons(len);
290 	MD5Init(&md5_ctx);
291 	MD5Update(&md5_ctx, (u_char *)wb->buf, len + RIP_AUTH_MD5_HASH_XTRA);
292 	MD5Update(&md5_ctx, ap->key, RIP_AUTH_MD5_KEY_LEN);
293 	MD5Final(na2->au.au_pw, &md5_ctx);
294 	wb->n++;
295 }
296 
297 
298 /* Send the buffer
299  */
300 static void
301 supply_write(struct ws_buf *wb)
302 {
303 	/* Output multicast only if legal.
304 	 * If we would multicast and it would be illegal, then discard the
305 	 * packet.
306 	 */
307 	switch (wb->type) {
308 	case NO_OUT_MULTICAST:
309 		trace_pkt("skip multicast to %s because impossible",
310 			  naddr_ntoa(ws.to.sin_addr.s_addr));
311 		break;
312 	case NO_OUT_RIPV2:
313 		break;
314 	default:
315 		if (ws.a != NULL && ws.a->type == RIP_AUTH_MD5)
316 			end_md5_auth(wb,ws.a);
317 		if (output(wb->type, &ws.to, ws.ifp, wb->buf,
318 			   ((char *)wb->n - (char*)wb->buf)) < 0
319 		    && ws.ifp != NULL)
320 			if_sick(ws.ifp);
321 		ws.npackets++;
322 		break;
323 	}
324 
325 	clr_ws_buf(wb,ws.a);
326 }
327 
328 
329 /* put an entry into the packet
330  */
331 static void
332 supply_out(struct ag_info *ag)
333 {
334 	int i;
335 	naddr mask, v1_mask, dst_h, ddst_h = 0;
336 	struct ws_buf *wb;
337 
338 
339 	/* Skip this route if doing a flash update and it and the routes
340 	 * it aggregates have not changed recently.
341 	 */
342 	if (ag->ag_seqno < update_seqno
343 	    && (ws.state & WS_ST_FLASH))
344 		return;
345 
346 	dst_h = ag->ag_dst_h;
347 	mask = ag->ag_mask;
348 	v1_mask = ripv1_mask_host(htonl(dst_h),
349 				  (ws.state & WS_ST_TO_ON_NET) ? ws.ifp : 0);
350 	i = 0;
351 
352 	/* If we are sending RIPv2 packets that cannot (or must not) be
353 	 * heard by RIPv1 listeners, do not worry about sub- or supernets.
354 	 * Subnets (from other networks) can only be sent via multicast.
355 	 * A pair of subnet routes might have been promoted so that they
356 	 * are legal to send by RIPv1.
357 	 * If RIPv1 is off, use the multicast buffer.
358 	 */
359 	if ((ws.state & WS_ST_RIP2_ALL)
360 	    || ((ag->ag_state & AGS_RIPV2) && v1_mask != mask)) {
361 		/* use the RIPv2-only buffer */
362 		wb = &v2buf;
363 
364 	} else {
365 		/* use the RIPv1-or-RIPv2 buffer */
366 		wb = &v12buf;
367 
368 		/* Convert supernet route into corresponding set of network
369 		 * routes for RIPv1, but leave non-contiguous netmasks
370 		 * to ag_check().
371 		 */
372 		if (v1_mask > mask
373 		    && mask + (mask & -mask) == 0) {
374 			ddst_h = v1_mask & -v1_mask;
375 			i = (v1_mask & ~mask)/ddst_h;
376 
377 			if (i > ws.gen_limit) {
378 				/* Punt if we would have to generate an
379 				 * unreasonable number of routes.
380 				 */
381 				if (TRACECONTENTS)
382 					trace_misc("sending %s-->%s as 1"
383 						   " instead of %d routes",
384 						   addrname(htonl(dst_h), mask,
385 							1),
386 						   naddr_ntoa(ws.to.sin_addr
387 							.s_addr),
388 						   i+1);
389 				i = 0;
390 
391 			} else {
392 				mask = v1_mask;
393 				ws.gen_limit -= i;
394 			}
395 		}
396 	}
397 
398 	do {
399 		wb->n->n_family = RIP_AF_INET;
400 		wb->n->n_dst = htonl(dst_h);
401 		/* If the route is from router-discovery or we are
402 		 * shutting down, admit only a bad metric.
403 		 */
404 		wb->n->n_metric = ((stopint || ag->ag_metric < 1)
405 				   ? HOPCNT_INFINITY
406 				   : ag->ag_metric);
407 		wb->n->n_metric = htonl(wb->n->n_metric);
408 		/* Any non-zero bits in the supposedly unused RIPv1 fields
409 		 * cause the old `routed` to ignore the route.
410 		 * That means the mask and so forth cannot be sent
411 		 * in the hybrid RIPv1/RIPv2 mode.
412 		 */
413 		if (ws.state & WS_ST_RIP2_ALL) {
414 			if (ag->ag_nhop != 0
415 			    && ((ws.state & WS_ST_QUERY)
416 				|| (ag->ag_nhop != ws.ifp->int_addr
417 				    && on_net(ag->ag_nhop,
418 					      ws.ifp->int_net,
419 					      ws.ifp->int_mask))))
420 				wb->n->n_nhop = ag->ag_nhop;
421 			wb->n->n_mask = htonl(mask);
422 			wb->n->n_tag = ag->ag_tag;
423 		}
424 		dst_h += ddst_h;
425 
426 		if (++wb->n >= wb->lim)
427 			supply_write(wb);
428 	} while (i-- != 0);
429 }
430 
431 
432 /* supply one route from the table
433  */
434 /* ARGSUSED */
435 static int
436 walk_supply(struct radix_node *rn,
437 	    struct walkarg *argp UNUSED)
438 {
439 #define RT ((struct rt_entry *)rn)
440 	u_short ags;
441 	char metric, pref;
442 	naddr dst, nhop;
443 	struct rt_spare *rts;
444 	int i;
445 
446 
447 	/* Do not advertise external remote interfaces or passive interfaces.
448 	 */
449 	if ((RT->rt_state & RS_IF)
450 	    && RT->rt_ifp != 0
451 	    && (RT->rt_ifp->int_state & IS_PASSIVE)
452 	    && !(RT->rt_state & RS_MHOME))
453 		return 0;
454 
455 	/* If being quiet about our ability to forward, then
456 	 * do not say anything unless responding to a query,
457 	 * except about our main interface.
458 	 */
459 	if (!supplier && !(ws.state & WS_ST_QUERY)
460 	    && !(RT->rt_state & RS_MHOME))
461 		return 0;
462 
463 	dst = RT->rt_dst;
464 
465 	/* do not collide with the fake default route */
466 	if (dst == RIP_DEFAULT
467 	    && (ws.state & WS_ST_DEFAULT))
468 		return 0;
469 
470 	if (RT->rt_state & RS_NET_SYN) {
471 		if (RT->rt_state & RS_NET_INT) {
472 			/* Do not send manual synthetic network routes
473 			 * into the subnet.
474 			 */
475 			if (on_net(ws.to.sin_addr.s_addr,
476 				   ntohl(dst), RT->rt_mask))
477 				return 0;
478 
479 		} else {
480 			/* Do not send automatic synthetic network routes
481 			 * if they are not needed because no RIPv1 listeners
482 			 * can hear them.
483 			 */
484 			if (ws.state & WS_ST_RIP2_ALL)
485 				return 0;
486 
487 			/* Do not send automatic synthetic network routes to
488 			 * the real subnet.
489 			 */
490 			if (on_net(ws.to.sin_addr.s_addr,
491 				   ntohl(dst), RT->rt_mask))
492 				return 0;
493 		}
494 		nhop = 0;
495 
496 	} else {
497 		/* Advertise the next hop if this is not a route for one
498 		 * of our interfaces and the next hop is on the same
499 		 * network as the target.
500 		 * The final determination is made by supply_out().
501 		 */
502 		if (!(RT->rt_state & RS_IF)
503 		    && RT->rt_gate != myaddr
504 		    && RT->rt_gate != loopaddr)
505 			nhop = RT->rt_gate;
506 		else
507 			nhop = 0;
508 	}
509 
510 	metric = RT->rt_metric;
511 	ags = 0;
512 
513 	if (RT->rt_state & RS_MHOME) {
514 		/* retain host route of multi-homed servers */
515 		;
516 
517 	} else if (RT_ISHOST(RT)) {
518 		/* We should always suppress (into existing network routes)
519 		 * the host routes for the local end of our point-to-point
520 		 * links.
521 		 * If we are suppressing host routes in general, then do so.
522 		 * Avoid advertising host routes onto their own network,
523 		 * where they should be handled by proxy-ARP.
524 		 */
525 		if ((RT->rt_state & RS_LOCAL)
526 		    || ridhosts
527 		    || on_net(dst, ws.to_net, ws.to_mask))
528 			ags |= AGS_SUPPRESS;
529 
530 		/* Aggregate stray host routes into network routes if allowed.
531 		 * We cannot aggregate host routes into small network routes
532 		 * without confusing RIPv1 listeners into thinking the
533 		 * network routes are host routes.
534 		 */
535 		if ((ws.state & WS_ST_AG) && (ws.state & WS_ST_RIP2_ALL))
536 			ags |= AGS_AGGREGATE;
537 
538 	} else {
539 		/* Always suppress network routes into other, existing
540 		 * network routes
541 		 */
542 		ags |= AGS_SUPPRESS;
543 
544 		/* Generate supernets if allowed.
545 		 * If we can be heard by RIPv1 systems, we will
546 		 * later convert back to ordinary nets.
547 		 * This unifies dealing with received supernets.
548 		 */
549 		if ((ws.state & WS_ST_AG)
550 		    && ((RT->rt_state & RS_SUBNET)
551 			|| (ws.state & WS_ST_SUPER_AG)))
552 			ags |= AGS_AGGREGATE;
553 	}
554 
555 	/* Do not send RIPv1 advertisements of subnets to other
556 	 * networks. If possible, multicast them by RIPv2.
557 	 */
558 	if ((RT->rt_state & RS_SUBNET)
559 	    && !(ws.state & WS_ST_RIP2_ALL)
560 	    && !on_net(dst, ws.to_std_net, ws.to_std_mask))
561 		ags |= AGS_RIPV2 | AGS_AGGREGATE;
562 
563 
564 	/* Do not send a route back to where it came from, except in
565 	 * response to a query.  This is "split-horizon".  That means not
566 	 * advertising back to the same network	and so via the same interface.
567 	 *
568 	 * We want to suppress routes that might have been fragmented
569 	 * from this route by a RIPv1 router and sent back to us, and so we
570 	 * cannot forget this route here.  Let the split-horizon route
571 	 * suppress the fragmented routes and then itself be forgotten.
572 	 *
573 	 * Include the routes for both ends of point-to-point interfaces
574 	 * among those suppressed by split-horizon, since the other side
575 	 * should knows them as well as we do.
576 	 *
577 	 * Notice spare routes with the same metric that we are about to
578 	 * advertise, to split the horizon on redundant, inactive paths.
579 	 *
580 	 * Do not suppress advertisements of interface-related addresses on
581 	 * non-point-to-point interfaces.  This ensures that we have something
582 	 * to say every 30 seconds to help detect broken Ethernets or
583 	 * other interfaces where one packet every 30 seconds costs nothing.
584 	 */
585 	if (ws.ifp != NULL
586 	    && !(ws.state & WS_ST_QUERY)
587 	    && (ws.state & WS_ST_TO_ON_NET)
588 	    && (!(RT->rt_state & RS_IF)
589 		|| ws.ifp->int_if_flags & IFF_POINTOPOINT)) {
590 		for (rts = RT->rt_spares, i = NUM_SPARES; i != 0; i--, rts++) {
591 			if (rts->rts_metric > metric
592 			    || rts->rts_ifp != ws.ifp)
593 				continue;
594 
595 			/* If we do not mark the route with AGS_SPLIT_HZ here,
596 			 * it will be poisoned-reverse, or advertised back
597 			 * toward its source with an infinite metric.
598 			 * If we have recently advertised the route with a
599 			 * better metric than we now have, then we should
600 			 * poison-reverse the route before suppressing it for
601 			 * split-horizon.
602 			 *
603 			 * In almost all cases, if there is no spare for the
604 			 * route then it is either old and dead or a brand
605 			 * new route. If it is brand new, there is no need
606 			 * for poison-reverse. If it is old and dead, it
607 			 * is already poisoned.
608 			 */
609 			if (RT->rt_poison_time < now_expire
610 			    || RT->rt_poison_metric >= metric
611 			    || RT->rt_spares[1].rts_gate == 0) {
612 				ags |= AGS_SPLIT_HZ;
613 				ags &= ~AGS_SUPPRESS;
614 			}
615 			metric = HOPCNT_INFINITY;
616 			break;
617 		}
618 	}
619 
620 	/* Keep track of the best metric with which the
621 	 * route has been advertised recently.
622 	 */
623 	if (RT->rt_poison_metric >= metric
624 	    || RT->rt_poison_time < now_expire) {
625 		RT->rt_poison_time = now.tv_sec;
626 		RT->rt_poison_metric = metric;
627 	}
628 
629 	/* Adjust the outgoing metric by the cost of the link.
630 	 * Avoid aggregation when a route is counting to infinity.
631 	 */
632 	pref = RT->rt_poison_metric + ws.metric;
633 	metric += ws.metric;
634 
635 	/* Do not advertise stable routes that will be ignored,
636 	 * unless we are answering a query.
637 	 * If the route recently was advertised with a metric that
638 	 * would have been less than infinity through this interface,
639 	 * we need to continue to advertise it in order to poison it.
640 	 */
641 	if (metric >= HOPCNT_INFINITY) {
642 		if (!(ws.state & WS_ST_QUERY)
643 		    && (pref >= HOPCNT_INFINITY
644 			|| RT->rt_poison_time < now_garbage))
645 			return 0;
646 
647 		metric = HOPCNT_INFINITY;
648 	}
649 
650 	ag_check(dst, RT->rt_mask, 0, nhop, metric, pref,
651 		 RT->rt_seqno, RT->rt_tag, ags, supply_out);
652 	return 0;
653 #undef RT
654 }
655 
656 
657 /* Supply dst with the contents of the routing tables.
658  * If this won't fit in one packet, chop it up into several.
659  */
660 void
661 supply(struct sockaddr_in *dst,
662        struct interface *ifp,		/* output interface */
663        enum output_type type,
664        int flash,			/* 1=flash update */
665        int vers,			/* RIP version */
666        int passwd_ok)			/* OK to include cleartext password */
667 {
668 	struct rt_entry *rt;
669 	int def_metric;
670 
671 	ws.state = 0;
672 	ws.gen_limit = 1024;
673 
674 	ws.to = *dst;
675 	ws.to_std_mask = std_mask(ws.to.sin_addr.s_addr);
676 	ws.to_std_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_std_mask;
677 
678 	if (ifp != NULL) {
679 		ws.to_mask = ifp->int_mask;
680 		ws.to_net = ifp->int_net;
681 		if (on_net(ws.to.sin_addr.s_addr, ws.to_net, ws.to_mask))
682 			ws.state |= WS_ST_TO_ON_NET;
683 
684 	} else {
685 		ws.to_mask = ripv1_mask_net(ws.to.sin_addr.s_addr, 0);
686 		ws.to_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_mask;
687 		rt = rtfind(dst->sin_addr.s_addr);
688 		if (rt)
689 			ifp = rt->rt_ifp;
690 	}
691 
692 	ws.npackets = 0;
693 	if (flash)
694 		ws.state |= WS_ST_FLASH;
695 
696 	if ((ws.ifp = ifp) == NULL) {
697 		ws.metric = 1;
698 	} else {
699 		/* Adjust the advertised metric by the outgoing interface
700 		 * metric.
701 		 */
702 		ws.metric = ifp->int_metric + 1 + ifp->int_adj_outmetric;
703 	}
704 
705 	ripv12_buf.rip.rip_vers = vers;
706 
707 	switch (type) {
708 	case OUT_MULTICAST:
709 		if (ifp != NULL && ifp->int_if_flags & IFF_MULTICAST)
710 			v2buf.type = OUT_MULTICAST;
711 		else
712 			v2buf.type = NO_OUT_MULTICAST;
713 		v12buf.type = OUT_BROADCAST;
714 		break;
715 
716 	case OUT_QUERY:
717 		ws.state |= WS_ST_QUERY;
718 		/* FALLTHROUGH */
719 	case OUT_BROADCAST:
720 	case OUT_UNICAST:
721 		v2buf.type = (vers == RIPv2) ? type : NO_OUT_RIPV2;
722 		v12buf.type = type;
723 		break;
724 
725 	case NO_OUT_MULTICAST:
726 	case NO_OUT_RIPV2:
727 		break;			/* no output */
728 	}
729 
730 	if (vers == RIPv2) {
731 		/* full RIPv2 only if cannot be heard by RIPv1 listeners */
732 		if (type != OUT_BROADCAST)
733 			ws.state |= WS_ST_RIP2_ALL;
734 		if ((ws.state & WS_ST_QUERY)
735 		    || !(ws.state & WS_ST_TO_ON_NET)) {
736 			ws.state |= (WS_ST_AG | WS_ST_SUPER_AG);
737 		} else if (ifp == NULL || !(ifp->int_state & IS_NO_AG)) {
738 			ws.state |= WS_ST_AG;
739 			if (type != OUT_BROADCAST
740 			    && (ifp == NULL
741 				|| !(ifp->int_state & IS_NO_SUPER_AG)))
742 				ws.state |= WS_ST_SUPER_AG;
743 		}
744 	}
745 
746 	ws.a = (vers == RIPv2) ? find_auth(ifp) : 0;
747 	if (!passwd_ok && ws.a != NULL && ws.a->type == RIP_AUTH_PW)
748 		ws.a = NULL;
749 	clr_ws_buf(&v12buf,ws.a);
750 	clr_ws_buf(&v2buf,ws.a);
751 
752 	/*  Fake a default route if asked and if there is not already
753 	 * a better, real default route.
754 	 */
755 	if (supplier && ifp && (def_metric = ifp->int_d_metric) != 0) {
756 		if ((rt = rtget(RIP_DEFAULT, 0)) == NULL
757 		    || rt->rt_metric+ws.metric >= def_metric) {
758 			ws.state |= WS_ST_DEFAULT;
759 			ag_check(0, 0, 0, 0, def_metric, def_metric,
760 				 0, 0, 0, supply_out);
761 		} else {
762 			def_metric = rt->rt_metric+ws.metric;
763 		}
764 
765 		/* If both RIPv2 and the poor-man's router discovery
766 		 * kludge are on, arrange to advertise an extra
767 		 * default route via RIPv1.
768 		 */
769 		if ((ws.state & WS_ST_RIP2_ALL)
770 		    && (ifp->int_state & IS_PM_RDISC)) {
771 			ripv12_buf.rip.rip_vers = RIPv1;
772 			v12buf.n->n_family = RIP_AF_INET;
773 			v12buf.n->n_dst = htonl(RIP_DEFAULT);
774 			v12buf.n->n_metric = htonl(def_metric);
775 			v12buf.n++;
776 		}
777 	}
778 
779 	(void)rn_walktree(rhead, walk_supply, 0);
780 	ag_flush(0,0,supply_out);
781 
782 	/* Flush the packet buffers, provided they are not empty and
783 	 * do not contain only the password.
784 	 */
785 	if (v12buf.n != v12buf.base
786 	    && (v12buf.n > v12buf.base+1
787 		|| v12buf.base->n_family != RIP_AF_AUTH))
788 		supply_write(&v12buf);
789 	if (v2buf.n != v2buf.base
790 	    && (v2buf.n > v2buf.base+1
791 		|| v2buf.base->n_family != RIP_AF_AUTH))
792 		supply_write(&v2buf);
793 
794 	/* If we sent nothing and this is an answer to a query, send
795 	 * an empty buffer.
796 	 */
797 	if (ws.npackets == 0
798 	    && (ws.state & WS_ST_QUERY))
799 		supply_write(&v12buf);
800 }
801 
802 
803 /* send all of the routing table or just do a flash update
804  */
805 void
806 rip_bcast(int flash)
807 {
808 #ifdef _HAVE_SIN_LEN
809 	static struct sockaddr_in dst = {sizeof(dst), AF_INET, 0, {0}, {0}};
810 #else
811 	static struct sockaddr_in dst = {AF_INET};
812 #endif
813 	struct interface *ifp;
814 	enum output_type type;
815 	int vers;
816 	struct timeval rtime;
817 
818 
819 	need_flash = 0;
820 	intvl_random(&rtime, MIN_WAITTIME, MAX_WAITTIME);
821 	no_flash = rtime;
822 	timevaladd(&no_flash, &now);
823 
824 	if (rip_sock < 0)
825 		return;
826 
827 	trace_act("send %s and inhibit dynamic updates for %.3f sec",
828 		  flash ? "dynamic update" : "all routes",
829 		  rtime.tv_sec + ((float)rtime.tv_usec)/1000000.0);
830 
831 	LIST_FOREACH(ifp, &ifnet, int_list) {
832 		/* Skip interfaces not doing RIP.
833 		 * Do try broken interfaces to see if they have healed.
834 		 */
835 		if (IS_RIP_OUT_OFF(ifp->int_state))
836 			continue;
837 
838 		/* skip turned off interfaces */
839 		if (!iff_up(ifp->int_if_flags))
840 			continue;
841 
842 		vers = (ifp->int_state & IS_NO_RIPV1_OUT) ? RIPv2 : RIPv1;
843 
844 		if (ifp->int_if_flags & IFF_BROADCAST) {
845 			/* ordinary, hardware interface */
846 			dst.sin_addr.s_addr = ifp->int_brdaddr;
847 
848 			if (vers == RIPv2
849 			    && !(ifp->int_state  & IS_NO_RIP_MCAST)) {
850 				type = OUT_MULTICAST;
851 			} else {
852 				type = OUT_BROADCAST;
853 			}
854 
855 		} else if (ifp->int_if_flags & IFF_POINTOPOINT) {
856 			/* point-to-point hardware interface */
857 			dst.sin_addr.s_addr = ifp->int_dstaddr;
858 			if (vers == RIPv2 &&
859 			    ifp->int_if_flags & IFF_MULTICAST &&
860 			    !(ifp->int_state  & IS_NO_RIP_MCAST)) {
861 				type = OUT_MULTICAST;
862 			} else {
863 				type = OUT_UNICAST;
864 			}
865 
866 		} else if (ifp->int_state & IS_REMOTE) {
867 			/* remote interface */
868 			dst.sin_addr.s_addr = ifp->int_addr;
869 			type = OUT_UNICAST;
870 
871 		} else {
872 			/* ATM, HIPPI, etc. */
873 			continue;
874 		}
875 
876 		supply(&dst, ifp, type, flash, vers, 1);
877 	}
878 
879 	update_seqno++;			/* all routes are up to date */
880 }
881 
882 
883 /* Ask for routes
884  * Do it only once to an interface, and not even after the interface
885  * was broken and recovered.
886  */
887 void
888 rip_query(void)
889 {
890 #ifdef _HAVE_SIN_LEN
891 	static struct sockaddr_in dst = {sizeof(dst), AF_INET, 0, {0}, {0}};
892 #else
893 	static struct sockaddr_in dst = {AF_INET};
894 #endif
895 	struct interface *ifp;
896 	struct rip buf;
897 	enum output_type type;
898 
899 
900 	if (rip_sock < 0)
901 		return;
902 
903 	memset(&buf, 0, sizeof(buf));
904 
905 	LIST_FOREACH(ifp, &ifnet, int_list) {
906 		/* Skip interfaces those already queried.
907 		 * Do not ask via interfaces through which we don't
908 		 * accept input.  Do not ask via interfaces that cannot
909 		 * send RIP packets.
910 		 * Do try broken interfaces to see if they have healed.
911 		 */
912 		if (IS_RIP_IN_OFF(ifp->int_state)
913 		    || ifp->int_query_time != NEVER)
914 			continue;
915 
916 		/* skip turned off interfaces */
917 		if (!iff_up(ifp->int_if_flags))
918 			continue;
919 
920 		buf.rip_vers = (ifp->int_state&IS_NO_RIPV1_OUT) ? RIPv2:RIPv1;
921 		buf.rip_cmd = RIPCMD_REQUEST;
922 		buf.rip_nets[0].n_family = RIP_AF_UNSPEC;
923 		buf.rip_nets[0].n_metric = htonl(HOPCNT_INFINITY);
924 
925 		/* Send a RIPv1 query only if allowed and if we will
926 		 * listen to RIPv1 routers.
927 		 */
928 		if ((ifp->int_state & IS_NO_RIPV1_OUT)
929 		    || (ifp->int_state & IS_NO_RIPV1_IN)) {
930 			buf.rip_vers = RIPv2;
931 		} else {
932 			buf.rip_vers = RIPv1;
933 		}
934 
935 		if (ifp->int_if_flags & IFF_BROADCAST) {
936 			/* ordinary, hardware interface */
937 			dst.sin_addr.s_addr = ifp->int_brdaddr;
938 
939 			/* Broadcast RIPv1 queries and RIPv2 queries
940 			 * when the hardware cannot multicast.
941 			 */
942 			if (buf.rip_vers == RIPv2
943 			    && (ifp->int_if_flags & IFF_MULTICAST)
944 			    && !(ifp->int_state  & IS_NO_RIP_MCAST)) {
945 				type = OUT_MULTICAST;
946 			} else {
947 				type = OUT_BROADCAST;
948 			}
949 
950 		} else if (ifp->int_if_flags & IFF_POINTOPOINT) {
951 			/* point-to-point hardware interface */
952 			dst.sin_addr.s_addr = ifp->int_dstaddr;
953 			type = OUT_UNICAST;
954 
955 		} else if (ifp->int_state & IS_REMOTE) {
956 			/* remote interface */
957 			dst.sin_addr.s_addr = ifp->int_addr;
958 			type = OUT_UNICAST;
959 
960 		} else {
961 			/* ATM, HIPPI, etc. */
962 			continue;
963 		}
964 
965 		ifp->int_query_time = now.tv_sec+SUPPLY_INTERVAL;
966 		if (output(type, &dst, ifp, &buf, sizeof(buf)) < 0)
967 			if_sick(ifp);
968 	}
969 }
970