xref: /freebsd/sbin/routed/output.c (revision 4c723140)
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 $"
41 #endif
42 #ident "$FreeBSD$"
43 
44 
45 u_int update_seqno;
46 
47 
48 /* walk the tree of routes with this for output
49  */
50 struct {
51 	struct sockaddr_in to;
52 	naddr	to_mask;
53 	naddr	to_net;
54 	naddr	to_std_mask;
55 	naddr	to_std_net;
56 	struct interface *ifp;		/* usually output interface */
57 	struct auth *a;
58 	char	metric;			/* adjust metrics by interface */
59 	int	npackets;
60 	int	gen_limit;
61 	u_int	state;
62 #define	    WS_ST_FLASH	    0x001	/* send only changed routes */
63 #define	    WS_ST_RIP2_ALL  0x002	/* send full featured RIPv2 */
64 #define	    WS_ST_AG	    0x004	/* ok to aggregate subnets */
65 #define	    WS_ST_SUPER_AG  0x008	/* ok to aggregate networks */
66 #define	    WS_ST_QUERY	    0x010	/* responding to a query */
67 #define	    WS_ST_TO_ON_NET 0x020	/* sending onto one of our nets */
68 #define	    WS_ST_DEFAULT   0x040	/* faking a default */
69 } ws;
70 
71 /* A buffer for what can be heard by both RIPv1 and RIPv2 listeners */
72 struct ws_buf v12buf;
73 union pkt_buf ripv12_buf;
74 
75 /* Another for only RIPv2 listeners */
76 struct ws_buf v2buf;
77 union pkt_buf rip_v2_buf;
78 
79 
80 
81 void
82 bufinit(void)
83 {
84 	ripv12_buf.rip.rip_cmd = RIPCMD_RESPONSE;
85 	v12buf.buf = &ripv12_buf.rip;
86 	v12buf.base = &v12buf.buf->rip_nets[0];
87 
88 	rip_v2_buf.rip.rip_cmd = RIPCMD_RESPONSE;
89 	rip_v2_buf.rip.rip_vers = RIPv2;
90 	v2buf.buf = &rip_v2_buf.rip;
91 	v2buf.base = &v2buf.buf->rip_nets[0];
92 }
93 
94 
95 /* Send the contents of the global buffer via the non-multicast socket
96  */
97 int					/* <0 on failure */
98 output(enum output_type type,
99        struct sockaddr_in *dst,		/* send to here */
100        struct interface *ifp,
101        struct rip *buf,
102        int size)			/* this many bytes */
103 {
104 	struct sockaddr_in osin;
105 	int flags;
106 	const char *msg;
107 	int res;
108 	naddr tgt_mcast;
109 	int soc;
110 	int serrno;
111 
112 	osin = *dst;
113 	if (osin.sin_port == 0)
114 		osin.sin_port = htons(RIP_PORT);
115 #ifdef _HAVE_SIN_LEN
116 	if (osin.sin_len == 0)
117 		osin.sin_len = sizeof(osin);
118 #endif
119 
120 	soc = rip_sock;
121 	flags = 0;
122 
123 	switch (type) {
124 	case OUT_QUERY:
125 		msg = "Answer Query";
126 		if (soc < 0)
127 			soc = ifp->int_rip_sock;
128 		break;
129 	case OUT_UNICAST:
130 		msg = "Send";
131 		if (soc < 0)
132 			soc = ifp->int_rip_sock;
133 		flags = MSG_DONTROUTE;
134 		break;
135 	case OUT_BROADCAST:
136 		if (ifp->int_if_flags & IFF_POINTOPOINT) {
137 			msg = "Send";
138 		} else {
139 			msg = "Send bcast";
140 		}
141 		flags = MSG_DONTROUTE;
142 		break;
143 	case OUT_MULTICAST:
144 		if (ifp->int_if_flags & 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 #ifdef MCAST_IFINDEX
155 				/* specify ifindex */
156 				tgt_mcast = htonl(ifp->int_index);
157 #else
158 #ifdef MCAST_PPP_BUG
159 				/* Do not specify the primary interface
160 				 * explicitly if we have the multicast
161 				 * point-to-point kernel bug, since the
162 				 * kernel will do the wrong thing if the
163 				 * local address of a point-to-point link
164 				 * is the same as the address of an ordinary
165 				 * interface.
166 				 */
167 				if (ifp->int_addr == myaddr) {
168 					tgt_mcast = 0;
169 				} else
170 #endif
171 				tgt_mcast = ifp->int_addr;
172 #endif
173 				if (0 > setsockopt(rip_sock,
174 						   IPPROTO_IP, IP_MULTICAST_IF,
175 						   &tgt_mcast,
176 						   sizeof(tgt_mcast))) {
177 					serrno = errno;
178 					LOGERR("setsockopt(rip_sock,"
179 					       "IP_MULTICAST_IF)");
180 					errno = serrno;
181 					ifp = 0;
182 					return -1;
183 				}
184 				rip_sock_mcast = ifp;
185 			}
186 			osin.sin_addr.s_addr = htonl(INADDR_RIP_GROUP);
187 		}
188 		break;
189 
190 	case NO_OUT_MULTICAST:
191 	case NO_OUT_RIPV2:
192 	default:
193 #ifdef DEBUG
194 		abort();
195 #endif
196 		return -1;
197 	}
198 
199 	trace_rip(msg, "to", &osin, ifp, buf, size);
200 
201 	res = sendto(soc, buf, size, flags,
202 		     (struct sockaddr *)&osin, sizeof(osin));
203 	if (res < 0
204 	    && (ifp == 0 || !(ifp->int_state & IS_BROKE))) {
205 		serrno = errno;
206 		msglog("%s sendto(%s%s%s.%d): %s", msg,
207 		       ifp != 0 ? ifp->int_name : "",
208 		       ifp != 0 ? ", " : "",
209 		       inet_ntoa(osin.sin_addr),
210 		       ntohs(osin.sin_port),
211 		       strerror(errno));
212 		errno = serrno;
213 	}
214 
215 	return res;
216 }
217 
218 
219 /* Find the first key for a packet to send.
220  * Try for a key that is eligible and has not expired, but settle for
221  * the last key if they have all expired.
222  * If no key is ready yet, give up.
223  */
224 struct auth *
225 find_auth(struct interface *ifp)
226 {
227 	struct auth *ap, *res;
228 	int i;
229 
230 
231 	if (ifp == 0)
232 		return 0;
233 
234 	res = 0;
235 	ap = ifp->int_auth;
236 	for (i = 0; i < MAX_AUTH_KEYS; i++, ap++) {
237 		/* stop looking after the last key */
238 		if (ap->type == RIP_AUTH_NONE)
239 			break;
240 
241 		/* ignore keys that are not ready yet */
242 		if ((u_long)ap->start > (u_long)clk.tv_sec)
243 			continue;
244 
245 		if ((u_long)ap->end < (u_long)clk.tv_sec) {
246 			/* note best expired password as a fall-back */
247 			if (res == 0 || (u_long)ap->end > (u_long)res->end)
248 				res = ap;
249 			continue;
250 		}
251 
252 		/* note key with the best future */
253 		if (res == 0 || (u_long)res->end < (u_long)ap->end)
254 			res = ap;
255 	}
256 	return res;
257 }
258 
259 
260 void
261 clr_ws_buf(struct ws_buf *wb,
262 	   struct auth *ap)
263 {
264 	struct netauth *na;
265 
266 	wb->lim = wb->base + NETS_LEN;
267 	wb->n = wb->base;
268 	memset(wb->n, 0, NETS_LEN*sizeof(*wb->n));
269 
270 	/* (start to) install authentication if appropriate
271 	 */
272 	if (ap == 0)
273 		return;
274 
275 	na = (struct netauth*)wb->n;
276 	if (ap->type == RIP_AUTH_PW) {
277 		na->a_family = RIP_AF_AUTH;
278 		na->a_type = RIP_AUTH_PW;
279 		memcpy(na->au.au_pw, ap->key, sizeof(na->au.au_pw));
280 		wb->n++;
281 
282 	} else if (ap->type ==  RIP_AUTH_MD5) {
283 		na->a_family = RIP_AF_AUTH;
284 		na->a_type = RIP_AUTH_MD5;
285 		na->au.a_md5.md5_keyid = ap->keyid;
286 		na->au.a_md5.md5_auth_len = RIP_AUTH_MD5_KEY_LEN;
287 		na->au.a_md5.md5_seqno = htonl(clk.tv_sec);
288 		wb->n++;
289 		wb->lim--;		/* make room for trailer */
290 	}
291 }
292 
293 
294 void
295 end_md5_auth(struct ws_buf *wb,
296 	     struct auth *ap)
297 {
298 	struct netauth *na, *na2;
299 	MD5_CTX md5_ctx;
300 	int len;
301 
302 
303 	na = (struct netauth*)wb->base;
304 	na2 = (struct netauth*)wb->n;
305 	len = (char *)na2-(char *)wb->buf;
306 	na2->a_family = RIP_AF_AUTH;
307 	na2->a_type = htons(1);
308 	na->au.a_md5.md5_pkt_len = htons(len);
309 	MD5Init(&md5_ctx);
310 	MD5Update(&md5_ctx, (u_char *)wb->buf, len + RIP_AUTH_MD5_HASH_XTRA);
311 	MD5Update(&md5_ctx, ap->key, RIP_AUTH_MD5_KEY_LEN);
312 	MD5Final(na2->au.au_pw, &md5_ctx);
313 	wb->n++;
314 }
315 
316 
317 /* Send the buffer
318  */
319 static void
320 supply_write(struct ws_buf *wb)
321 {
322 	/* Output multicast only if legal.
323 	 * If we would multicast and it would be illegal, then discard the
324 	 * packet.
325 	 */
326 	switch (wb->type) {
327 	case NO_OUT_MULTICAST:
328 		trace_pkt("skip multicast to %s because impossible",
329 			  naddr_ntoa(ws.to.sin_addr.s_addr));
330 		break;
331 	case NO_OUT_RIPV2:
332 		break;
333 	default:
334 		if (ws.a != 0 && ws.a->type == RIP_AUTH_MD5)
335 			end_md5_auth(wb,ws.a);
336 		if (output(wb->type, &ws.to, ws.ifp, wb->buf,
337 			   ((char *)wb->n - (char*)wb->buf)) < 0
338 		    && ws.ifp != 0)
339 			if_sick(ws.ifp);
340 		ws.npackets++;
341 		break;
342 	}
343 
344 	clr_ws_buf(wb,ws.a);
345 }
346 
347 
348 /* put an entry into the packet
349  */
350 static void
351 supply_out(struct ag_info *ag)
352 {
353 	int i;
354 	naddr mask, v1_mask, dst_h, ddst_h = 0;
355 	struct ws_buf *wb;
356 
357 
358 	/* Skip this route if doing a flash update and it and the routes
359 	 * it aggregates have not changed recently.
360 	 */
361 	if (ag->ag_seqno < update_seqno
362 	    && (ws.state & WS_ST_FLASH))
363 		return;
364 
365 	dst_h = ag->ag_dst_h;
366 	mask = ag->ag_mask;
367 	v1_mask = ripv1_mask_host(htonl(dst_h),
368 				  (ws.state & WS_ST_TO_ON_NET) ? ws.ifp : 0);
369 	i = 0;
370 
371 	/* If we are sending RIPv2 packets that cannot (or must not) be
372 	 * heard by RIPv1 listeners, do not worry about sub- or supernets.
373 	 * Subnets (from other networks) can only be sent via multicast.
374 	 * A pair of subnet routes might have been promoted so that they
375 	 * are legal to send by RIPv1.
376 	 * If RIPv1 is off, use the multicast buffer.
377 	 */
378 	if ((ws.state & WS_ST_RIP2_ALL)
379 	    || ((ag->ag_state & AGS_RIPV2) && v1_mask != mask)) {
380 		/* use the RIPv2-only buffer */
381 		wb = &v2buf;
382 
383 	} else {
384 		/* use the RIPv1-or-RIPv2 buffer */
385 		wb = &v12buf;
386 
387 		/* Convert supernet route into corresponding set of network
388 		 * routes for RIPv1, but leave non-contiguous netmasks
389 		 * to ag_check().
390 		 */
391 		if (v1_mask > mask
392 		    && mask + (mask & -mask) == 0) {
393 			ddst_h = v1_mask & -v1_mask;
394 			i = (v1_mask & ~mask)/ddst_h;
395 
396 			if (i > ws.gen_limit) {
397 				/* Punt if we would have to generate an
398 				 * unreasonable number of routes.
399 				 */
400 				if (TRACECONTENTS)
401 					trace_misc("sending %s-->%s as 1"
402 						   " instead of %d routes",
403 						   addrname(htonl(dst_h), mask,
404 							1),
405 						   naddr_ntoa(ws.to.sin_addr
406 							.s_addr),
407 						   i+1);
408 				i = 0;
409 
410 			} else {
411 				mask = v1_mask;
412 				ws.gen_limit -= i;
413 			}
414 		}
415 	}
416 
417 	do {
418 		wb->n->n_family = RIP_AF_INET;
419 		wb->n->n_dst = htonl(dst_h);
420 		/* If the route is from router-discovery or we are
421 		 * shutting down, admit only a bad metric.
422 		 */
423 		wb->n->n_metric = ((stopint || ag->ag_metric < 1)
424 				   ? HOPCNT_INFINITY
425 				   : ag->ag_metric);
426 		wb->n->n_metric = htonl(wb->n->n_metric);
427 		/* Any non-zero bits in the supposedly unused RIPv1 fields
428 		 * cause the old `routed` to ignore the route.
429 		 * That means the mask and so forth cannot be sent
430 		 * in the hybrid RIPv1/RIPv2 mode.
431 		 */
432 		if (ws.state & WS_ST_RIP2_ALL) {
433 			if (ag->ag_nhop != 0
434 			    && ((ws.state & WS_ST_QUERY)
435 				|| (ag->ag_nhop != ws.ifp->int_addr
436 				    && on_net(ag->ag_nhop,
437 					      ws.ifp->int_net,
438 					      ws.ifp->int_mask))))
439 				wb->n->n_nhop = ag->ag_nhop;
440 			wb->n->n_mask = htonl(mask);
441 			wb->n->n_tag = ag->ag_tag;
442 		}
443 		dst_h += ddst_h;
444 
445 		if (++wb->n >= wb->lim)
446 			supply_write(wb);
447 	} while (i-- != 0);
448 }
449 
450 
451 /* supply one route from the table
452  */
453 /* ARGSUSED */
454 static int
455 walk_supply(struct radix_node *rn,
456 	    struct walkarg *argp UNUSED)
457 {
458 #define RT ((struct rt_entry *)rn)
459 	u_short ags;
460 	char metric, pref;
461 	naddr dst, nhop;
462 	struct rt_spare *rts;
463 	int i;
464 
465 
466 	/* Do not advertise external remote interfaces or passive interfaces.
467 	 */
468 	if ((RT->rt_state & RS_IF)
469 	    && RT->rt_ifp != 0
470 	    && (RT->rt_ifp->int_state & IS_PASSIVE)
471 	    && !(RT->rt_state & RS_MHOME))
472 		return 0;
473 
474 	/* If being quiet about our ability to forward, then
475 	 * do not say anything unless responding to a query,
476 	 * except about our main interface.
477 	 */
478 	if (!supplier && !(ws.state & WS_ST_QUERY)
479 	    && !(RT->rt_state & RS_MHOME))
480 		return 0;
481 
482 	dst = RT->rt_dst;
483 
484 	/* do not collide with the fake default route */
485 	if (dst == RIP_DEFAULT
486 	    && (ws.state & WS_ST_DEFAULT))
487 		return 0;
488 
489 	if (RT->rt_state & RS_NET_SYN) {
490 		if (RT->rt_state & RS_NET_INT) {
491 			/* Do not send manual synthetic network routes
492 			 * into the subnet.
493 			 */
494 			if (on_net(ws.to.sin_addr.s_addr,
495 				   ntohl(dst), RT->rt_mask))
496 				return 0;
497 
498 		} else {
499 			/* Do not send automatic synthetic network routes
500 			 * if they are not needed because no RIPv1 listeners
501 			 * can hear them.
502 			 */
503 			if (ws.state & WS_ST_RIP2_ALL)
504 				return 0;
505 
506 			/* Do not send automatic synthetic network routes to
507 			 * the real subnet.
508 			 */
509 			if (on_net(ws.to.sin_addr.s_addr,
510 				   ntohl(dst), RT->rt_mask))
511 				return 0;
512 		}
513 		nhop = 0;
514 
515 	} else {
516 		/* Advertise the next hop if this is not a route for one
517 		 * of our interfaces and the next hop is on the same
518 		 * network as the target.
519 		 * The final determination is made by supply_out().
520 		 */
521 		if (!(RT->rt_state & RS_IF)
522 		    && RT->rt_gate != myaddr
523 		    && RT->rt_gate != loopaddr)
524 			nhop = RT->rt_gate;
525 		else
526 			nhop = 0;
527 	}
528 
529 	metric = RT->rt_metric;
530 	ags = 0;
531 
532 	if (RT->rt_state & RS_MHOME) {
533 		/* retain host route of multi-homed servers */
534 		;
535 
536 	} else if (RT_ISHOST(RT)) {
537 		/* We should always suppress (into existing network routes)
538 		 * the host routes for the local end of our point-to-point
539 		 * links.
540 		 * If we are suppressing host routes in general, then do so.
541 		 * Avoid advertising host routes onto their own network,
542 		 * where they should be handled by proxy-ARP.
543 		 */
544 		if ((RT->rt_state & RS_LOCAL)
545 		    || ridhosts
546 		    || on_net(dst, ws.to_net, ws.to_mask))
547 			ags |= AGS_SUPPRESS;
548 
549 		/* Aggregate stray host routes into network routes if allowed.
550 		 * We cannot aggregate host routes into small network routes
551 		 * without confusing RIPv1 listeners into thinking the
552 		 * network routes are host routes.
553 		 */
554 		if ((ws.state & WS_ST_AG) && (ws.state & WS_ST_RIP2_ALL))
555 			ags |= AGS_AGGREGATE;
556 
557 	} else {
558 		/* Always suppress network routes into other, existing
559 		 * network routes
560 		 */
561 		ags |= AGS_SUPPRESS;
562 
563 		/* Generate supernets if allowed.
564 		 * If we can be heard by RIPv1 systems, we will
565 		 * later convert back to ordinary nets.
566 		 * This unifies dealing with received supernets.
567 		 */
568 		if ((ws.state & WS_ST_AG)
569 		    && ((RT->rt_state & RS_SUBNET)
570 			|| (ws.state & WS_ST_SUPER_AG)))
571 			ags |= AGS_AGGREGATE;
572 	}
573 
574 	/* Do not send RIPv1 advertisements of subnets to other
575 	 * networks. If possible, multicast them by RIPv2.
576 	 */
577 	if ((RT->rt_state & RS_SUBNET)
578 	    && !(ws.state & WS_ST_RIP2_ALL)
579 	    && !on_net(dst, ws.to_std_net, ws.to_std_mask))
580 		ags |= AGS_RIPV2 | AGS_AGGREGATE;
581 
582 
583 	/* Do not send a route back to where it came from, except in
584 	 * response to a query.  This is "split-horizon".  That means not
585 	 * advertising back to the same network	and so via the same interface.
586 	 *
587 	 * We want to suppress routes that might have been fragmented
588 	 * from this route by a RIPv1 router and sent back to us, and so we
589 	 * cannot forget this route here.  Let the split-horizon route
590 	 * suppress the fragmented routes and then itself be forgotten.
591 	 *
592 	 * Include the routes for both ends of point-to-point interfaces
593 	 * among those suppressed by split-horizon, since the other side
594 	 * should knows them as well as we do.
595 	 *
596 	 * Notice spare routes with the same metric that we are about to
597 	 * advertise, to split the horizon on redundant, inactive paths.
598 	 *
599 	 * Do not suppress advertisements of interface-related addresses on
600 	 * non-point-to-point interfaces.  This ensures that we have something
601 	 * to say every 30 seconds to help detect broken Ethernets or
602 	 * other interfaces where one packet every 30 seconds costs nothing.
603 	 */
604 	if (ws.ifp != 0
605 	    && !(ws.state & WS_ST_QUERY)
606 	    && (ws.state & WS_ST_TO_ON_NET)
607 	    && (!(RT->rt_state & RS_IF)
608 		|| ws.ifp->int_if_flags & IFF_POINTOPOINT)) {
609 		for (rts = RT->rt_spares, i = NUM_SPARES; i != 0; i--, rts++) {
610 			if (rts->rts_metric > metric
611 			    || rts->rts_ifp != ws.ifp)
612 				continue;
613 
614 			/* If we do not mark the route with AGS_SPLIT_HZ here,
615 			 * it will be poisoned-reverse, or advertised back
616 			 * toward its source with an infinite metric.
617 			 * If we have recently advertised the route with a
618 			 * better metric than we now have, then we should
619 			 * poison-reverse the route before suppressing it for
620 			 * split-horizon.
621 			 *
622 			 * In almost all cases, if there is no spare for the
623 			 * route then it is either old and dead or a brand
624 			 * new route. If it is brand new, there is no need
625 			 * for poison-reverse. If it is old and dead, it
626 			 * is already poisoned.
627 			 */
628 			if (RT->rt_poison_time < now_expire
629 			    || RT->rt_poison_metric >= metric
630 			    || RT->rt_spares[1].rts_gate == 0) {
631 				ags |= AGS_SPLIT_HZ;
632 				ags &= ~AGS_SUPPRESS;
633 			}
634 			metric = HOPCNT_INFINITY;
635 			break;
636 		}
637 	}
638 
639 	/* Keep track of the best metric with which the
640 	 * route has been advertised recently.
641 	 */
642 	if (RT->rt_poison_metric >= metric
643 	    || RT->rt_poison_time < now_expire) {
644 		RT->rt_poison_time = now.tv_sec;
645 		RT->rt_poison_metric = metric;
646 	}
647 
648 	/* Adjust the outgoing metric by the cost of the link.
649 	 * Avoid aggregation when a route is counting to infinity.
650 	 */
651 	pref = RT->rt_poison_metric + ws.metric;
652 	metric += ws.metric;
653 
654 	/* Do not advertise stable routes that will be ignored,
655 	 * unless we are answering a query.
656 	 * If the route recently was advertised with a metric that
657 	 * would have been less than infinity through this interface,
658 	 * we need to continue to advertise it in order to poison it.
659 	 */
660 	if (metric >= HOPCNT_INFINITY) {
661 		if (!(ws.state & WS_ST_QUERY)
662 		    && (pref >= HOPCNT_INFINITY
663 			|| RT->rt_poison_time < now_garbage))
664 			return 0;
665 
666 		metric = HOPCNT_INFINITY;
667 	}
668 
669 	ag_check(dst, RT->rt_mask, 0, nhop, metric, pref,
670 		 RT->rt_seqno, RT->rt_tag, ags, supply_out);
671 	return 0;
672 #undef RT
673 }
674 
675 
676 /* Supply dst with the contents of the routing tables.
677  * If this won't fit in one packet, chop it up into several.
678  */
679 void
680 supply(struct sockaddr_in *dst,
681        struct interface *ifp,		/* output interface */
682        enum output_type type,
683        int flash,			/* 1=flash update */
684        int vers,			/* RIP version */
685        int passwd_ok)			/* OK to include cleartext password */
686 {
687 	struct rt_entry *rt;
688 	int def_metric;
689 
690 
691 	ws.state = 0;
692 	ws.gen_limit = 1024;
693 
694 	ws.to = *dst;
695 	ws.to_std_mask = std_mask(ws.to.sin_addr.s_addr);
696 	ws.to_std_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_std_mask;
697 
698 	if (ifp != 0) {
699 		ws.to_mask = ifp->int_mask;
700 		ws.to_net = ifp->int_net;
701 		if (on_net(ws.to.sin_addr.s_addr, ws.to_net, ws.to_mask))
702 			ws.state |= WS_ST_TO_ON_NET;
703 
704 	} else {
705 		ws.to_mask = ripv1_mask_net(ws.to.sin_addr.s_addr, 0);
706 		ws.to_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_mask;
707 		rt = rtfind(dst->sin_addr.s_addr);
708 		if (rt)
709 			ifp = rt->rt_ifp;
710 	}
711 
712 	ws.npackets = 0;
713 	if (flash)
714 		ws.state |= WS_ST_FLASH;
715 
716 	if ((ws.ifp = ifp) == 0) {
717 		ws.metric = 1;
718 	} else {
719 		/* Adjust the advertised metric by the outgoing interface
720 		 * metric.
721 		 */
722 		ws.metric = ifp->int_metric + 1 + ifp->int_adj_outmetric;
723 	}
724 
725 	ripv12_buf.rip.rip_vers = vers;
726 
727 	switch (type) {
728 	case OUT_MULTICAST:
729 		if (ifp->int_if_flags & IFF_MULTICAST)
730 			v2buf.type = OUT_MULTICAST;
731 		else
732 			v2buf.type = NO_OUT_MULTICAST;
733 		v12buf.type = OUT_BROADCAST;
734 		break;
735 
736 	case OUT_QUERY:
737 		ws.state |= WS_ST_QUERY;
738 		/* FALLTHROUGH */
739 	case OUT_BROADCAST:
740 	case OUT_UNICAST:
741 		v2buf.type = (vers == RIPv2) ? type : NO_OUT_RIPV2;
742 		v12buf.type = type;
743 		break;
744 
745 	case NO_OUT_MULTICAST:
746 	case NO_OUT_RIPV2:
747 		break;			/* no output */
748 	}
749 
750 	if (vers == RIPv2) {
751 		/* full RIPv2 only if cannot be heard by RIPv1 listeners */
752 		if (type != OUT_BROADCAST)
753 			ws.state |= WS_ST_RIP2_ALL;
754 		if ((ws.state & WS_ST_QUERY)
755 		    || !(ws.state & WS_ST_TO_ON_NET)) {
756 			ws.state |= (WS_ST_AG | WS_ST_SUPER_AG);
757 		} else if (ifp == 0 || !(ifp->int_state & IS_NO_AG)) {
758 			ws.state |= WS_ST_AG;
759 			if (type != OUT_BROADCAST
760 			    && (ifp == 0
761 				|| !(ifp->int_state & IS_NO_SUPER_AG)))
762 				ws.state |= WS_ST_SUPER_AG;
763 		}
764 	}
765 
766 	ws.a = (vers == RIPv2) ? find_auth(ifp) : 0;
767 	if (!passwd_ok && ws.a != 0 && ws.a->type == RIP_AUTH_PW)
768 		ws.a = 0;
769 	clr_ws_buf(&v12buf,ws.a);
770 	clr_ws_buf(&v2buf,ws.a);
771 
772 	/*  Fake a default route if asked and if there is not already
773 	 * a better, real default route.
774 	 */
775 	if (supplier && (def_metric = ifp->int_d_metric) != 0) {
776 		if (0 == (rt = rtget(RIP_DEFAULT, 0))
777 		    || rt->rt_metric+ws.metric >= def_metric) {
778 			ws.state |= WS_ST_DEFAULT;
779 			ag_check(0, 0, 0, 0, def_metric, def_metric,
780 				 0, 0, 0, supply_out);
781 		} else {
782 			def_metric = rt->rt_metric+ws.metric;
783 		}
784 
785 		/* If both RIPv2 and the poor-man's router discovery
786 		 * kludge are on, arrange to advertise an extra
787 		 * default route via RIPv1.
788 		 */
789 		if ((ws.state & WS_ST_RIP2_ALL)
790 		    && (ifp->int_state & IS_PM_RDISC)) {
791 			ripv12_buf.rip.rip_vers = RIPv1;
792 			v12buf.n->n_family = RIP_AF_INET;
793 			v12buf.n->n_dst = htonl(RIP_DEFAULT);
794 			v12buf.n->n_metric = htonl(def_metric);
795 			v12buf.n++;
796 		}
797 	}
798 
799 	(void)rn_walktree(rhead, walk_supply, 0);
800 	ag_flush(0,0,supply_out);
801 
802 	/* Flush the packet buffers, provided they are not empty and
803 	 * do not contain only the password.
804 	 */
805 	if (v12buf.n != v12buf.base
806 	    && (v12buf.n > v12buf.base+1
807 		|| v12buf.base->n_family != RIP_AF_AUTH))
808 		supply_write(&v12buf);
809 	if (v2buf.n != v2buf.base
810 	    && (v2buf.n > v2buf.base+1
811 		|| v2buf.base->n_family != RIP_AF_AUTH))
812 		supply_write(&v2buf);
813 
814 	/* If we sent nothing and this is an answer to a query, send
815 	 * an empty buffer.
816 	 */
817 	if (ws.npackets == 0
818 	    && (ws.state & WS_ST_QUERY))
819 		supply_write(&v12buf);
820 }
821 
822 
823 /* send all of the routing table or just do a flash update
824  */
825 void
826 rip_bcast(int flash)
827 {
828 #ifdef _HAVE_SIN_LEN
829 	static struct sockaddr_in dst = {sizeof(dst), AF_INET, 0, {0}, {0}};
830 #else
831 	static struct sockaddr_in dst = {AF_INET};
832 #endif
833 	struct interface *ifp;
834 	enum output_type type;
835 	int vers;
836 	struct timeval rtime;
837 
838 
839 	need_flash = 0;
840 	intvl_random(&rtime, MIN_WAITTIME, MAX_WAITTIME);
841 	no_flash = rtime;
842 	timevaladd(&no_flash, &now);
843 
844 	if (rip_sock < 0)
845 		return;
846 
847 	trace_act("send %s and inhibit dynamic updates for %.3f sec",
848 		  flash ? "dynamic update" : "all routes",
849 		  rtime.tv_sec + ((float)rtime.tv_usec)/1000000.0);
850 
851 	for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
852 		/* Skip interfaces not doing RIP.
853 		 * Do try broken interfaces to see if they have healed.
854 		 */
855 		if (IS_RIP_OUT_OFF(ifp->int_state))
856 			continue;
857 
858 		/* skip turned off interfaces */
859 		if (!iff_up(ifp->int_if_flags))
860 			continue;
861 
862 		vers = (ifp->int_state & IS_NO_RIPV1_OUT) ? RIPv2 : RIPv1;
863 
864 		if (ifp->int_if_flags & IFF_BROADCAST) {
865 			/* ordinary, hardware interface */
866 			dst.sin_addr.s_addr = ifp->int_brdaddr;
867 
868 			if (vers == RIPv2
869 			    && !(ifp->int_state  & IS_NO_RIP_MCAST)) {
870 				type = OUT_MULTICAST;
871 			} else {
872 				type = OUT_BROADCAST;
873 			}
874 
875 		} else if (ifp->int_if_flags & IFF_POINTOPOINT) {
876 			/* point-to-point hardware interface */
877 			dst.sin_addr.s_addr = ifp->int_dstaddr;
878 			type = OUT_UNICAST;
879 
880 		} else if (ifp->int_state & IS_REMOTE) {
881 			/* remote interface */
882 			dst.sin_addr.s_addr = ifp->int_addr;
883 			type = OUT_UNICAST;
884 
885 		} else {
886 			/* ATM, HIPPI, etc. */
887 			continue;
888 		}
889 
890 		supply(&dst, ifp, type, flash, vers, 1);
891 	}
892 
893 	update_seqno++;			/* all routes are up to date */
894 }
895 
896 
897 /* Ask for routes
898  * Do it only once to an interface, and not even after the interface
899  * was broken and recovered.
900  */
901 void
902 rip_query(void)
903 {
904 #ifdef _HAVE_SIN_LEN
905 	static struct sockaddr_in dst = {sizeof(dst), AF_INET, 0, {0}, {0}};
906 #else
907 	static struct sockaddr_in dst = {AF_INET};
908 #endif
909 	struct interface *ifp;
910 	struct rip buf;
911 	enum output_type type;
912 
913 
914 	if (rip_sock < 0)
915 		return;
916 
917 	memset(&buf, 0, sizeof(buf));
918 
919 	for (ifp = ifnet; ifp; ifp = ifp->int_next) {
920 		/* Skip interfaces those already queried.
921 		 * Do not ask via interfaces through which we don't
922 		 * accept input.  Do not ask via interfaces that cannot
923 		 * send RIP packets.
924 		 * Do try broken interfaces to see if they have healed.
925 		 */
926 		if (IS_RIP_IN_OFF(ifp->int_state)
927 		    || ifp->int_query_time != NEVER)
928 			continue;
929 
930 		/* skip turned off interfaces */
931 		if (!iff_up(ifp->int_if_flags))
932 			continue;
933 
934 		buf.rip_vers = (ifp->int_state&IS_NO_RIPV1_OUT) ? RIPv2:RIPv1;
935 		buf.rip_cmd = RIPCMD_REQUEST;
936 		buf.rip_nets[0].n_family = RIP_AF_UNSPEC;
937 		buf.rip_nets[0].n_metric = htonl(HOPCNT_INFINITY);
938 
939 		/* Send a RIPv1 query only if allowed and if we will
940 		 * listen to RIPv1 routers.
941 		 */
942 		if ((ifp->int_state & IS_NO_RIPV1_OUT)
943 		    || (ifp->int_state & IS_NO_RIPV1_IN)) {
944 			buf.rip_vers = RIPv2;
945 		} else {
946 			buf.rip_vers = RIPv1;
947 		}
948 
949 		if (ifp->int_if_flags & IFF_BROADCAST) {
950 			/* ordinary, hardware interface */
951 			dst.sin_addr.s_addr = ifp->int_brdaddr;
952 
953 			/* Broadcast RIPv1 queries and RIPv2 queries
954 			 * when the hardware cannot multicast.
955 			 */
956 			if (buf.rip_vers == RIPv2
957 			    && (ifp->int_if_flags & IFF_MULTICAST)
958 			    && !(ifp->int_state  & IS_NO_RIP_MCAST)) {
959 				type = OUT_MULTICAST;
960 			} else {
961 				type = OUT_BROADCAST;
962 			}
963 
964 		} else if (ifp->int_if_flags & IFF_POINTOPOINT) {
965 			/* point-to-point hardware interface */
966 			dst.sin_addr.s_addr = ifp->int_dstaddr;
967 			type = OUT_UNICAST;
968 
969 		} else if (ifp->int_state & IS_REMOTE) {
970 			/* remote interface */
971 			dst.sin_addr.s_addr = ifp->int_addr;
972 			type = OUT_UNICAST;
973 
974 		} else {
975 			/* ATM, HIPPI, etc. */
976 			continue;
977 		}
978 
979 		ifp->int_query_time = now.tv_sec+SUPPLY_INTERVAL;
980 		if (output(type, &dst, ifp, &buf, sizeof(buf)) < 0)
981 			if_sick(ifp);
982 	}
983 }
984