xref: /netbsd-src/sbin/routed/output.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: output.c,v 1.14 1997/09/15 11:51:57 lukem Exp $	*/
2 
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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #if !defined(lint) && !defined(sgi) && !defined(__NetBSD__)
37 static char sccsid[] = "@(#)output.c	8.1 (Berkeley) 6/5/93";
38 #elif defined(__NetBSD__)
39 #include <sys/cdefs.h>
40 __RCSID("$NetBSD: output.c,v 1.14 1997/09/15 11:51:57 lukem Exp $");
41 #endif
42 
43 #include "defs.h"
44 
45 
46 int update_seqno;
47 
48 
49 /* walk the tree of routes with this for output
50  */
51 struct {
52 	struct sockaddr_in to;
53 	naddr	to_mask;
54 	naddr	to_net;
55 	naddr	to_std_mask;
56 	naddr	to_std_net;
57 	struct interface *ifp;		/* usually output interface */
58 	struct auth *a;
59 	char	metric;			/* adjust metrics by interface */
60 	int	npackets;
61 	int	gen_limit;
62 	u_int	state;
63 #define	    WS_ST_FLASH	    0x001	/* send only changed routes */
64 #define	    WS_ST_RIP2_ALL  0x002	/* send full featured RIPv2 */
65 #define	    WS_ST_AG	    0x004	/* ok to aggregate subnets */
66 #define	    WS_ST_SUPER_AG  0x008	/* ok to aggregate networks */
67 #define	    WS_ST_SUB_AG    0x010	/* aggregate subnets in odd case */
68 #define	    WS_ST_QUERY	    0x020	/* responding to a query */
69 #define	    WS_ST_TO_ON_NET 0x040	/* sending onto one of our nets */
70 #define	    WS_ST_DEFAULT   0x080	/* faking a default */
71 } ws;
72 
73 /* A buffer for what can be heard by both RIPv1 and RIPv2 listeners */
74 struct ws_buf v12buf;
75 union pkt_buf ripv12_buf;
76 
77 /* Another for only RIPv2 listeners */
78 struct ws_buf v2buf;
79 union pkt_buf rip_v2_buf;
80 
81 
82 
83 void
84 bufinit(void)
85 {
86 	ripv12_buf.rip.rip_cmd = RIPCMD_RESPONSE;
87 	v12buf.buf = &ripv12_buf.rip;
88 	v12buf.base = &v12buf.buf->rip_nets[0];
89 
90 	rip_v2_buf.rip.rip_cmd = RIPCMD_RESPONSE;
91 	rip_v2_buf.rip.rip_vers = RIPv2;
92 	v2buf.buf = &rip_v2_buf.rip;
93 	v2buf.base = &v2buf.buf->rip_nets[0];
94 }
95 
96 
97 /* Send the contents of the global buffer via the non-multicast socket
98  */
99 int					/* <0 on failure */
100 output(enum output_type type,
101        struct sockaddr_in *dst,		/* send to here */
102        struct interface *ifp,
103        struct rip *buf,
104        int size)			/* this many bytes */
105 {
106 	struct sockaddr_in sin;
107 	int flags;
108 	char *msg;
109 	int res;
110 	naddr tgt_mcast;
111 	int soc;
112 	int serrno;
113 
114 	sin = *dst;
115 	if (sin.sin_port == 0)
116 		sin.sin_port = htons(RIP_PORT);
117 #ifdef _HAVE_SIN_LEN
118 	if (sin.sin_len == 0)
119 		sin.sin_len = sizeof(sin);
120 #endif
121 
122 	soc = rip_sock;
123 	flags = 0;
124 
125 	switch (type) {
126 	case OUT_QUERY:
127 		msg = "Answer Query";
128 		if (soc < 0)
129 			soc = ifp->int_rip_sock;
130 		break;
131 	case OUT_UNICAST:
132 		msg = "Send";
133 		if (soc < 0)
134 			soc = ifp->int_rip_sock;
135 		flags = MSG_DONTROUTE;
136 		break;
137 	case OUT_BROADCAST:
138 		if (ifp->int_if_flags & IFF_POINTOPOINT) {
139 			msg = "Send";
140 		} else {
141 			msg = "Send bcast";
142 		}
143 		flags = MSG_DONTROUTE;
144 		break;
145 	case OUT_MULTICAST:
146 		if (ifp->int_if_flags & IFF_POINTOPOINT) {
147 			msg = "Send pt-to-pt";
148 		} else if (ifp->int_state & IS_DUP) {
149 			trace_act("abort multicast output via %s"
150 				  " with duplicate address",
151 				  ifp->int_name);
152 			return 0;
153 		} else {
154 			msg = "Send mcast";
155 			if (rip_sock_mcast != ifp) {
156 #ifdef MCAST_PPP_BUG
157 				/* Do not specifiy the primary interface
158 				 * explicitly if we have the multicast
159 				 * point-to-point kernel bug, since the
160 				 * kernel will do the wrong thing if the
161 				 * local address of a point-to-point link
162 				 * is the same as the address of an ordinary
163 				 * interface.
164 				 */
165 				if (ifp->int_addr == myaddr) {
166 					tgt_mcast = 0;
167 				} else
168 #endif
169 				tgt_mcast = ifp->int_addr;
170 				if (0 > setsockopt(rip_sock,
171 						   IPPROTO_IP, IP_MULTICAST_IF,
172 						   &tgt_mcast,
173 						   sizeof(tgt_mcast))) {
174 					serrno = errno;
175 					LOGERR("setsockopt(rip_sock,"
176 					       "IP_MULTICAST_IF)");
177 					errno = serrno;
178 					ifp = 0;
179 					return -1;
180 				}
181 				rip_sock_mcast = ifp;
182 			}
183 			sin.sin_addr.s_addr = htonl(INADDR_RIP_GROUP);
184 		}
185 		break;
186 
187 	case NO_OUT_MULTICAST:
188 	case NO_OUT_RIPV2:
189 	default:
190 #ifdef DEBUG
191 		abort();
192 #endif
193 		return -1;
194 	}
195 
196 	trace_rip(msg, "to", &sin, ifp, buf, size);
197 
198 	res = sendto(soc, buf, size, flags,
199 		     (struct sockaddr *)&sin, sizeof(sin));
200 	if (res < 0
201 	    && (ifp == 0 || !(ifp->int_state & IS_BROKE))) {
202 		serrno = errno;
203 		msglog("%s sendto(%s%s%s.%d): %s", msg,
204 		       ifp != 0 ? ifp->int_name : "",
205 		       ifp != 0 ? ", " : "",
206 		       inet_ntoa(sin.sin_addr),
207 		       ntohs(sin.sin_port),
208 		       strerror(errno));
209 		errno = serrno;
210 	}
211 
212 	return res;
213 }
214 
215 
216 /* Find the first key for a packet to send.
217  * Try for a key that is eligable and has not expired, but settle for
218  * the last key if they have all expired.
219  * If no key is ready yet, give up.
220  */
221 struct auth *
222 find_auth(struct interface *ifp)
223 {
224 	struct auth *ap, *res;
225 	int i;
226 
227 
228 	if (ifp == 0)
229 		return 0;
230 
231 	res = 0;
232 	ap = ifp->int_auth;
233 	for (i = 0; i < MAX_AUTH_KEYS; i++, ap++) {
234 		/* stop looking after the last key */
235 		if (ap->type == RIP_AUTH_NONE)
236 			break;
237 
238 		/* ignore keys that are not ready yet */
239 		if ((u_long)ap->start > (u_long)clk.tv_sec)
240 			continue;
241 
242 		if ((u_long)ap->end < (u_long)clk.tv_sec) {
243 			/* note best expired password as a fall-back */
244 			if (res == 0 || (u_long)ap->end > (u_long)res->end)
245 				res = ap;
246 			continue;
247 		}
248 
249 		/* note key with the best future */
250 		if (res == 0 || (u_long)res->end < (u_long)ap->end)
251 			res = ap;
252 	}
253 	return res;
254 }
255 
256 
257 void
258 clr_ws_buf(struct ws_buf *wb,
259 	   struct auth *ap)
260 {
261 	struct netauth *na;
262 
263 	wb->lim = wb->base + NETS_LEN;
264 	wb->n = wb->base;
265 	memset(wb->n, 0, NETS_LEN*sizeof(*wb->n));
266 
267 	/* install authentication if appropriate
268 	 */
269 	if (ap == 0)
270 		return;
271 	na = (struct netauth*)wb->n;
272 	if (ap->type == RIP_AUTH_PW) {
273 		na->a_family = RIP_AF_AUTH;
274 		na->a_type = RIP_AUTH_PW;
275 		memmove(na->au.au_pw, ap->key, sizeof(na->au.au_pw));
276 		wb->n++;
277 
278 	} else if (ap->type ==  RIP_AUTH_MD5) {
279 		na->a_family = RIP_AF_AUTH;
280 		na->a_type = RIP_AUTH_MD5;
281 		na->au.a_md5.md5_keyid = ap->keyid;
282 		na->au.a_md5.md5_auth_len = RIP_AUTH_PW_LEN;
283 		na->au.a_md5.md5_seqno = clk.tv_sec;
284 		wb->n++;
285 		wb->lim--;		/* make room for trailer */
286 	}
287 }
288 
289 
290 void
291 end_md5_auth(struct ws_buf *wb,
292 	     struct auth *ap)
293 {
294 	struct netauth *na, *na2;
295 	MD5_CTX md5_ctx;
296 
297 
298 	na = (struct netauth*)wb->base;
299 	na2 = (struct netauth*)wb->n;
300 	na2->a_family = RIP_AF_AUTH;
301 	na2->a_type = 1;
302 	memmove(na2->au.au_pw, ap->key, sizeof(na2->au.au_pw));
303 	na->au.a_md5.md5_pkt_len = (char *)na2-(char *)(na+1);
304 	MD5Init(&md5_ctx);
305 	MD5Update(&md5_ctx, (u_char *)na,
306 		  (char *)(na2+1) - (char *)na);
307 	MD5Final(na2->au.au_pw, &md5_ctx);
308 	wb->n++;
309 }
310 
311 
312 /* Send the buffer
313  */
314 static void
315 supply_write(struct ws_buf *wb)
316 {
317 	/* Output multicast only if legal.
318 	 * If we would multcast and it would be illegal, then discard the
319 	 * packet.
320 	 */
321 	switch (wb->type) {
322 	case NO_OUT_MULTICAST:
323 		trace_pkt("skip multicast to %s because impossible",
324 			  naddr_ntoa(ws.to.sin_addr.s_addr));
325 		break;
326 	case NO_OUT_RIPV2:
327 		break;
328 	default:
329 		if (ws.a != 0 && ws.a->type == RIP_AUTH_MD5)
330 			end_md5_auth(wb,ws.a);
331 		if (output(wb->type, &ws.to, ws.ifp, wb->buf,
332 			   ((char *)wb->n - (char*)wb->buf)) < 0
333 		    && ws.ifp != 0)
334 			if_sick(ws.ifp);
335 		ws.npackets++;
336 		break;
337 	}
338 
339 	clr_ws_buf(wb,ws.a);
340 }
341 
342 
343 /* put an entry into the packet
344  */
345 static void
346 supply_out(struct ag_info *ag)
347 {
348 	int i;
349 	naddr mask, v1_mask, dst_h, ddst_h = 0;
350 	struct ws_buf *wb;
351 
352 
353 	/* Skip this route if doing a flash update and it and the routes
354 	 * it aggregates have not changed recently.
355 	 */
356 	if (ag->ag_seqno < update_seqno
357 	    && (ws.state & WS_ST_FLASH))
358 		return;
359 
360 	/* Skip this route if required by split-horizon.
361 	 */
362 	if (ag->ag_state & AGS_SPLIT_HZ)
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 #ifdef DEBUG
401 				msglog("sending %s to %s as 1 instead"
402 				       " of %d routes",
403 				       addrname(htonl(dst_h),mask,1),
404 				       naddr_ntoa(ws.to.sin_addr.s_addr),
405 				       i+1);
406 #endif
407 				i = 0;
408 
409 			} else {
410 				mask = v1_mask;
411 				ws.gen_limit -= i;
412 			}
413 		}
414 	}
415 
416 	do {
417 		wb->n->n_family = RIP_AF_INET;
418 		wb->n->n_dst = htonl(dst_h);
419 		/* If the route is from router-discovery or we are
420 		 * shutting down, admit only a bad metric.
421 		 */
422 		wb->n->n_metric = ((stopint || ag->ag_metric < 1)
423 				   ? HOPCNT_INFINITY
424 				   : ag->ag_metric);
425 		HTONL(wb->n->n_metric);
426 		/* Any non-zero bits in the supposedly unused RIPv1 fields
427 		 * cause the old `routed` to ignore the route.
428 		 * That means the mask and so forth cannot be sent
429 		 * in the hybrid RIPv1/RIPv2 mode.
430 		 */
431 		if (ws.state & WS_ST_RIP2_ALL) {
432 			if (ag->ag_nhop != 0
433 			    && ((ws.state & WS_ST_QUERY)
434 				|| (ag->ag_nhop != ws.ifp->int_addr
435 				    && on_net(ag->ag_nhop,
436 					      ws.ifp->int_net,
437 					      ws.ifp->int_mask))))
438 				wb->n->n_nhop = ag->ag_nhop;
439 			wb->n->n_mask = htonl(mask);
440 			wb->n->n_tag = ag->ag_tag;
441 		}
442 		dst_h += ddst_h;
443 
444 		if (++wb->n >= wb->lim)
445 			supply_write(wb);
446 	} while (i-- != 0);
447 }
448 
449 
450 /* supply one route from the table
451  */
452 /* ARGSUSED */
453 static int
454 walk_supply(struct radix_node *rn, struct walkarg *argp)
455 {
456 #define RT ((struct rt_entry *)rn)
457 	u_short ags;
458 	char metric, pref;
459 	naddr dst, nhop;
460 	struct rt_spare *rts;
461 	int i;
462 
463 
464 	/* Do not advertise external remote interfaces or passive interfaces.
465 	 */
466 	if ((RT->rt_state & RS_IF)
467 	    && RT->rt_ifp != 0
468 	    && (RT->rt_ifp->int_if_flags & IS_PASSIVE)
469 	    && !(RT->rt_state & RS_MHOME))
470 		return 0;
471 
472 	/* If being quiet about our ability to forward, then
473 	 * do not say anything unless responding to a query,
474 	 * except about our main interface.
475 	 */
476 	if (!supplier && !(ws.state & WS_ST_QUERY)
477 	    && !(RT->rt_state & RS_MHOME))
478 		return 0;
479 
480 	dst = RT->rt_dst;
481 
482 	/* do not collide with the fake default route */
483 	if (dst == RIP_DEFAULT
484 	    && (ws.state & WS_ST_DEFAULT))
485 		return 0;
486 
487 	if (RT->rt_state & RS_NET_SYN) {
488 		if (RT->rt_state & RS_NET_INT) {
489 			/* Do not send manual synthetic network routes
490 			 * into the subnet.
491 			 */
492 			if (on_net(ws.to.sin_addr.s_addr,
493 				   ntohl(dst), RT->rt_mask))
494 				return 0;
495 
496 		} else {
497 			/* Do not send automatic synthetic network routes
498 			 * if they are not needed becaus no RIPv1 listeners
499 			 * can hear them.
500 			 */
501 			if (ws.state & WS_ST_RIP2_ALL)
502 				return 0;
503 
504 			/* Do not send automatic synthetic network routes to
505 			 * the real subnet.
506 			 */
507 			if (on_net(ws.to.sin_addr.s_addr,
508 				   ntohl(dst), RT->rt_mask))
509 				return 0;
510 		}
511 		nhop = 0;
512 
513 	} else {
514 		/* Advertise the next hop if this is not a route for one
515 		 * of our interfaces and the next hop is on the same
516 		 * network as the target.
517 		 */
518 		if (!(RT->rt_state & RS_IF)
519 		    && RT->rt_gate != myaddr
520 		    && RT->rt_gate != loopaddr)
521 			nhop = RT->rt_gate;
522 		else
523 			nhop = 0;
524 	}
525 
526 	metric = RT->rt_metric;
527 	ags = 0;
528 
529 	if (RT->rt_state & RS_MHOME) {
530 		/* retain host route of multi-homed servers */
531 		;
532 
533 	} else if (RT_ISHOST(RT)) {
534 		/* We should always aggregate the host routes
535 		 * for the local end of our point-to-point links.
536 		 * If we are suppressing host routes in general, then do so.
537 		 * Avoid advertising host routes onto their own network,
538 		 * where they should be handled by proxy-ARP.
539 		 */
540 		if ((RT->rt_state & RS_LOCAL)
541 		    || ridhosts
542 		    || (ws.state & WS_ST_SUPER_AG)
543 		    || on_net(dst, ws.to_net, ws.to_mask))
544 			ags |= AGS_SUPPRESS;
545 
546 		if (ws.state & WS_ST_SUPER_AG)
547 			ags |= AGS_PROMOTE;
548 
549 	} else if (ws.state & WS_ST_AG) {
550 		/* Aggregate network routes, if we are allowed.
551 		 */
552 		ags |= AGS_SUPPRESS;
553 
554 		/* Generate supernets if allowed.
555 		 * If we can be heard by RIPv1 systems, we will
556 		 * later convert back to ordinary nets.
557 		 * This unifies dealing with received supernets.
558 		 */
559 		if ((RT->rt_state & RS_SUBNET)
560 		    || (ws.state & WS_ST_SUPER_AG))
561 			ags |= AGS_PROMOTE;
562 
563 	}
564 
565 	/* Do not send RIPv1 advertisements of subnets to other
566 	 * networks. If possible, multicast them by RIPv2.
567 	 */
568 	if ((RT->rt_state & RS_SUBNET)
569 	    && !(ws.state & WS_ST_RIP2_ALL)
570 	    && !on_net(dst, ws.to_std_net, ws.to_std_mask)) {
571 		ags |= AGS_RIPV2 | AGS_PROMOTE;
572 		if (ws.state & WS_ST_SUB_AG)
573 			ags |= AGS_SUPPRESS;
574 	}
575 
576 	/* Do not send a route back to where it came from, except in
577 	 * response to a query.  This is "split-horizon".  That means not
578 	 * advertising back to the same network	and so via the same interface.
579 	 *
580 	 * We want to suppress routes that might have been fragmented
581 	 * from this route by a RIPv1 router and sent back to us, and so we
582 	 * cannot forget this route here.  Let the split-horizon route
583 	 * aggregate (suppress) the fragmented routes and then itself be
584 	 * forgotten.
585 	 *
586 	 * Include the routes for both ends of point-to-point interfaces
587 	 * among those suppressed by split-horizon, since the other side
588 	 * should knows them as well as we do.
589 	 *
590 	 * Notice spare routes with the same metric that we are about to
591 	 * advertise, to split the horizon on redunant, inactive paths.
592 	 */
593 	if (ws.ifp != 0
594 	    && !(ws.state & WS_ST_QUERY)
595 	    && (ws.state & WS_ST_TO_ON_NET)
596 	    && (!(RT->rt_state & RS_IF)
597 		|| ws.ifp->int_if_flags & IFF_POINTOPOINT)) {
598 		for (rts = RT->rt_spares, i = NUM_SPARES; i != 0; i--, rts++) {
599 			if (rts->rts_ifp == ws.ifp
600 			    && rts->rts_metric <= metric)
601 				break;
602 		}
603 		if (i != 0) {
604 			/* If we do not mark the route with AGS_SPLIT_HZ here,
605 			 * it will be poisoned-reverse, or advertised back
606 			 * toward its source with an infinite metric.
607 			 * If we have recently advertised the route with a
608 			 * better metric than we now have, then we should
609 			 * poison-reverse the route before suppressing it for
610 			 * split-horizon.
611 			 *
612 			 * In almost all cases, if there is no spare for the
613 			 * route then it is either old and dead or a brand
614 			 * new route. If it is brand new, there is no need
615 			 * for poison-reverse. If it is old and dead, it
616 			 * is already poisoned.
617 			 */
618 			if (RT->rt_poison_time < now_expire
619 			    || RT->rt_poison_metric >= metric
620 			    || RT->rt_spares[1].rts_gate == 0) {
621 				ags |= AGS_SPLIT_HZ;
622 				ags &= ~(AGS_PROMOTE | AGS_SUPPRESS);
623 			}
624 			metric = HOPCNT_INFINITY;
625 		}
626 	}
627 
628 	/* Keep track of the best metric with which the
629 	 * route has been advertised recently.
630 	 */
631 	if (RT->rt_poison_metric >= metric
632 	    || RT->rt_poison_time < now_expire) {
633 		RT->rt_poison_time = now.tv_sec;
634 		RT->rt_poison_metric = metric;
635 	}
636 
637 	/* Adjust the outgoing metric by the cost of the link.
638 	 * Avoid aggregation when a route is counting to infinity.
639 	 */
640 	pref = RT->rt_poison_metric + ws.metric;
641 	metric += ws.metric;
642 
643 	/* Do not advertise stable routes that will be ignored,
644 	 * unless we are answering a query.
645 	 * If the route recently was advertised with a metric that
646 	 * would have been less than infinity through this interface,
647 	 * we need to continue to advertise it in order to poison it.
648 	 */
649 	if (metric >= HOPCNT_INFINITY) {
650 		if (!(ws.state & WS_ST_QUERY)
651 		    && (pref >= HOPCNT_INFINITY
652 			|| RT->rt_poison_time < now_garbage))
653 			return 0;
654 
655 		metric = HOPCNT_INFINITY;
656 	}
657 
658 	ag_check(dst, RT->rt_mask, 0, nhop, metric, pref,
659 		 RT->rt_seqno, RT->rt_tag, ags, supply_out);
660 	return 0;
661 #undef RT
662 }
663 
664 
665 /* Supply dst with the contents of the routing tables.
666  * If this won't fit in one packet, chop it up into several.
667  */
668 void
669 supply(struct sockaddr_in *dst,
670        struct interface *ifp,		/* output interface */
671        enum output_type type,
672        int flash,			/* 1=flash update */
673        int vers,			/* RIP version */
674        int passwd_ok)			/* OK to include cleartext password */
675 {
676 	struct rt_entry *rt;
677 	int def_metric;
678 
679 
680 	ws.state = 0;
681 	ws.gen_limit = 1024;
682 
683 	ws.to = *dst;
684 	ws.to_std_mask = std_mask(ws.to.sin_addr.s_addr);
685 	ws.to_std_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_std_mask;
686 
687 	if (ifp != 0) {
688 		ws.to_mask = ifp->int_mask;
689 		ws.to_net = ifp->int_net;
690 		if (on_net(ws.to.sin_addr.s_addr, ws.to_net, ws.to_mask))
691 			ws.state |= WS_ST_TO_ON_NET;
692 
693 	} else {
694 		ws.to_mask = ripv1_mask_net(ws.to.sin_addr.s_addr, 0);
695 		ws.to_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_mask;
696 		rt = rtfind(dst->sin_addr.s_addr);
697 		if (rt)
698 			ifp = rt->rt_ifp;
699 	}
700 
701 	ws.npackets = 0;
702 	if (flash)
703 		ws.state |= WS_ST_FLASH;
704 	if (type == OUT_QUERY)
705 		ws.state |= WS_ST_QUERY;
706 
707 	if ((ws.ifp = ifp) == 0) {
708 		ws.metric = 1;
709 	} else {
710 		/* Adjust the advertised metric by the outgoing interface
711 		 * metric.
712 		 */
713 		ws.metric = ifp->int_metric+1;
714 	}
715 
716 	ripv12_buf.rip.rip_vers = vers;
717 
718 	switch (type) {
719 	case OUT_BROADCAST:
720 		v2buf.type = ((ifp != 0 && (ifp->int_if_flags & IFF_MULTICAST))
721 			      ? OUT_MULTICAST
722 			      : NO_OUT_MULTICAST);
723 		v12buf.type = OUT_BROADCAST;
724 		break;
725 	case OUT_MULTICAST:
726 		v2buf.type = ((ifp != 0 && (ifp->int_if_flags & IFF_MULTICAST))
727 			      ? OUT_MULTICAST
728 			      : NO_OUT_MULTICAST);
729 		v12buf.type = OUT_BROADCAST;
730 		break;
731 	case OUT_UNICAST:
732 	case OUT_QUERY:
733 		v2buf.type = (vers == RIPv2) ? type : NO_OUT_RIPV2;
734 		v12buf.type = type;
735 		break;
736 	default:
737 		v2buf.type = type;
738 		v12buf.type = type;
739 		break;
740 	}
741 
742 	if (vers == RIPv2) {
743 		/* full RIPv2 only if cannot be heard by RIPv1 listeners */
744 		if (type != OUT_BROADCAST)
745 			ws.state |= WS_ST_RIP2_ALL;
746 		if (!(ws.state & WS_ST_TO_ON_NET)) {
747 			ws.state |= (WS_ST_AG | WS_ST_SUPER_AG);
748 		} else if (ifp == 0 || !(ifp->int_state & IS_NO_AG)) {
749 			ws.state |= WS_ST_AG;
750 			if (type != OUT_BROADCAST
751 			    && (ifp == 0 || !(ifp->int_state&IS_NO_SUPER_AG)))
752 				ws.state |= WS_ST_SUPER_AG;
753 		}
754 
755 	} else if (ifp == 0 || !(ifp->int_state & IS_NO_AG)) {
756 		ws.state |= WS_ST_SUB_AG;
757 	}
758 
759 	ws.a = (vers == RIPv2) ? find_auth(ifp) : 0;
760 	if (!passwd_ok && ws.a != 0 && ws.a->type == RIP_AUTH_PW)
761 		ws.a = 0;
762 	clr_ws_buf(&v12buf,ws.a);
763 	clr_ws_buf(&v2buf,ws.a);
764 
765 	/*  Fake a default route if asked and if there is not already
766 	 * a better, real default route.
767 	 */
768 	if (supplier && (def_metric = ifp->int_d_metric) != 0) {
769 		if (0 == (rt = rtget(RIP_DEFAULT, 0))
770 		    || rt->rt_metric+ws.metric >= def_metric) {
771 			ws.state |= WS_ST_DEFAULT;
772 			ag_check(0, 0, 0, 0, def_metric, def_metric,
773 				 0, 0, 0, supply_out);
774 		} else {
775 			def_metric = rt->rt_metric+ws.metric;
776 		}
777 
778 		/* If both RIPv2 and the poor-man's router discovery
779 		 * kludge are on, arrange to advertise an extra
780 		 * default route via RIPv1.
781 		 */
782 		if ((ws.state & WS_ST_RIP2_ALL)
783 		    && (ifp->int_state & IS_PM_RDISC)) {
784 			ripv12_buf.rip.rip_vers = RIPv1;
785 			v12buf.n->n_family = RIP_AF_INET;
786 			v12buf.n->n_dst = htonl(RIP_DEFAULT);
787 			v12buf.n->n_metric = htonl(def_metric);
788 			v12buf.n++;
789 		}
790 	}
791 
792 	(void)rn_walktree(rhead, walk_supply, 0);
793 	ag_flush(0,0,supply_out);
794 
795 	/* Flush the packet buffers, provided they are not empty and
796 	 * do not contain only the password.
797 	 */
798 	if (v12buf.n != v12buf.base
799 	    && (v12buf.n > v12buf.base+1
800 		|| v12buf.base->n_family != RIP_AF_AUTH))
801 		supply_write(&v12buf);
802 	if (v2buf.n != v2buf.base
803 	    && (v2buf.n > v2buf.base+1
804 		|| v2buf.base->n_family != RIP_AF_AUTH))
805 		supply_write(&v2buf);
806 
807 	/* If we sent nothing and this is an answer to a query, send
808 	 * an empty buffer.
809 	 */
810 	if (ws.npackets == 0
811 	    && (ws.state & WS_ST_QUERY))
812 		supply_write(&v12buf);
813 }
814 
815 
816 /* send all of the routing table or just do a flash update
817  */
818 void
819 rip_bcast(int flash)
820 {
821 #ifdef _HAVE_SIN_LEN
822 	static struct sockaddr_in dst = {sizeof(dst), AF_INET};
823 #else
824 	static struct sockaddr_in dst = {AF_INET};
825 #endif
826 	struct interface *ifp;
827 	enum output_type type;
828 	int vers;
829 	struct timeval rtime;
830 
831 
832 	need_flash = 0;
833 	intvl_random(&rtime, MIN_WAITTIME, MAX_WAITTIME);
834 	no_flash = rtime;
835 	timevaladd(&no_flash, &now);
836 
837 	if (rip_sock < 0)
838 		return;
839 
840 	trace_act("send %s and inhibit dynamic updates for %.3f sec",
841 		  flash ? "dynamic update" : "all routes",
842 		  rtime.tv_sec + ((float)rtime.tv_usec)/1000000.0);
843 
844 	for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
845 		/* Skip interfaces not doing RIP.
846 		 * Do try broken interfaces to see if they have healed.
847 		 */
848 		if (IS_RIP_OUT_OFF(ifp->int_state))
849 			continue;
850 
851 		/* skip turned off interfaces */
852 		if (!iff_alive(ifp->int_if_flags))
853 			continue;
854 
855 		vers = (ifp->int_state & IS_NO_RIPV1_OUT) ? RIPv2 : RIPv1;
856 
857 		if (ifp->int_if_flags & IFF_BROADCAST) {
858 			/* ordinary, hardware interface */
859 			dst.sin_addr.s_addr = ifp->int_brdaddr;
860 
861 			/* If RIPv1 is not turned off, then broadcast so
862 			 * that RIPv1 listeners can hear.
863 			 */
864 			if (vers == RIPv2
865 			    && (ifp->int_state & IS_NO_RIPV1_OUT)) {
866 				type = OUT_MULTICAST;
867 			} else {
868 				type = OUT_BROADCAST;
869 			}
870 
871 		} else if (ifp->int_if_flags & IFF_POINTOPOINT) {
872 			/* point-to-point hardware interface */
873 			dst.sin_addr.s_addr = ifp->int_dstaddr;
874 			type = OUT_UNICAST;
875 
876 		} else if (ifp->int_state & IS_REMOTE) {
877 			/* remote interface */
878 			dst.sin_addr.s_addr = ifp->int_addr;
879 			type = OUT_UNICAST;
880 
881 		} else {
882 			/* ATM, HIPPI, etc. */
883 			continue;
884 		}
885 
886 		supply(&dst, ifp, type, flash, vers, 1);
887 	}
888 
889 	update_seqno++;			/* all routes are up to date */
890 }
891 
892 
893 /* Ask for routes
894  * Do it only once to an interface, and not even after the interface
895  * was broken and recovered.
896  */
897 void
898 rip_query(void)
899 {
900 #ifdef _HAVE_SIN_LEN
901 	static struct sockaddr_in dst = {sizeof(dst), AF_INET};
902 #else
903 	static struct sockaddr_in dst = {AF_INET};
904 #endif
905 	struct interface *ifp;
906 	struct rip buf;
907 	enum output_type type;
908 
909 
910 	if (rip_sock < 0)
911 		return;
912 
913 	memset(&buf, 0, sizeof(buf));
914 
915 	for (ifp = ifnet; ifp; ifp = ifp->int_next) {
916 		/* Skip interfaces those already queried.
917 		 * Do not ask via interfaces through which we don't
918 		 * accept input.  Do not ask via interfaces that cannot
919 		 * send RIP packets.
920 		 * Do try broken interfaces to see if they have healed.
921 		 */
922 		if (IS_RIP_IN_OFF(ifp->int_state)
923 		    || ifp->int_query_time != NEVER)
924 			continue;
925 
926 		/* skip turned off interfaces */
927 		if (!iff_alive(ifp->int_if_flags))
928 			continue;
929 
930 		buf.rip_vers = (ifp->int_state&IS_NO_RIPV1_OUT) ? RIPv2:RIPv1;
931 		buf.rip_cmd = RIPCMD_REQUEST;
932 		buf.rip_nets[0].n_family = RIP_AF_UNSPEC;
933 		buf.rip_nets[0].n_metric = htonl(HOPCNT_INFINITY);
934 
935 		if (ifp->int_if_flags & IFF_BROADCAST) {
936 			/* ordinary, hardware interface */
937 			dst.sin_addr.s_addr = ifp->int_brdaddr;
938 			/* if RIPv1 is not turned off, then broadcast so
939 			 * that RIPv1 listeners can hear.
940 			 */
941 			if (buf.rip_vers == RIPv2
942 			    && (ifp->int_state & IS_NO_RIPV1_OUT)) {
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