xref: /dragonfly/sbin/routed/output.c (revision 71126e33)
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  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgment:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * $FreeBSD: src/sbin/routed/output.c,v 1.5.2.1 2000/08/14 17:00:03 sheldonh Exp $
34  * $DragonFly: src/sbin/routed/output.c,v 1.4 2004/12/18 21:43:40 swildner Exp $
35  */
36 
37 #include "defs.h"
38 
39 #if !defined(sgi) && !defined(__NetBSD__)
40 static char sccsid[] __attribute__((unused)) = "@(#)output.c	8.1 (Berkeley) 6/5/93";
41 #elif defined(__NetBSD__)
42 __RCSID("$NetBSD$");
43 #endif
44 #ident "$FreeBSD: src/sbin/routed/output.c,v 1.5.2.1 2000/08/14 17:00:03 sheldonh Exp $"
45 
46 
47 u_int update_seqno;
48 
49 
50 /* walk the tree of routes with this for output
51  */
52 struct {
53 	struct sockaddr_in to;
54 	naddr	to_mask;
55 	naddr	to_net;
56 	naddr	to_std_mask;
57 	naddr	to_std_net;
58 	struct interface *ifp;		/* usually output interface */
59 	struct auth *a;
60 	char	metric;			/* adjust metrics by interface */
61 	int	npackets;
62 	int	gen_limit;
63 	u_int	state;
64 #define	    WS_ST_FLASH	    0x001	/* send only changed routes */
65 #define	    WS_ST_RIP2_ALL  0x002	/* send full featured RIPv2 */
66 #define	    WS_ST_AG	    0x004	/* ok to aggregate subnets */
67 #define	    WS_ST_SUPER_AG  0x008	/* ok to aggregate networks */
68 #define	    WS_ST_QUERY	    0x010	/* responding to a query */
69 #define	    WS_ST_TO_ON_NET 0x020	/* sending onto one of our nets */
70 #define	    WS_ST_DEFAULT   0x040	/* 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 	const 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 specify 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 eligible 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 	/* (start to) install authentication if appropriate
268 	 */
269 	if (ap == 0)
270 		return;
271 
272 	na = (struct netauth*)wb->n;
273 	if (ap->type == RIP_AUTH_PW) {
274 		na->a_family = RIP_AF_AUTH;
275 		na->a_type = RIP_AUTH_PW;
276 		memcpy(na->au.au_pw, ap->key, sizeof(na->au.au_pw));
277 		wb->n++;
278 
279 	} else if (ap->type ==  RIP_AUTH_MD5) {
280 		na->a_family = RIP_AF_AUTH;
281 		na->a_type = RIP_AUTH_MD5;
282 		na->au.a_md5.md5_keyid = ap->keyid;
283 		na->au.a_md5.md5_auth_len = RIP_AUTH_MD5_LEN;
284 		na->au.a_md5.md5_seqno = htonl(clk.tv_sec);
285 		wb->n++;
286 		wb->lim--;		/* make room for trailer */
287 	}
288 }
289 
290 
291 void
292 end_md5_auth(struct ws_buf *wb,
293 	     struct auth *ap)
294 {
295 	struct netauth *na, *na2;
296 	MD5_CTX md5_ctx;
297 	int len;
298 
299 
300 	na = (struct netauth*)wb->base;
301 	na2 = (struct netauth*)wb->n;
302 	len = (char *)na2-(char *)wb->buf;
303 	na2->a_family = RIP_AF_AUTH;
304 	na2->a_type = htons(1);
305 	na->au.a_md5.md5_pkt_len = htons(len);
306 	MD5Init(&md5_ctx);
307 	MD5Update(&md5_ctx, (u_char *)wb->buf, len);
308 	MD5Update(&md5_ctx, ap->key, RIP_AUTH_MD5_LEN);
309 	MD5Final(na2->au.au_pw, &md5_ctx);
310 	wb->n++;
311 }
312 
313 
314 /* Send the buffer
315  */
316 static void
317 supply_write(struct ws_buf *wb)
318 {
319 	/* Output multicast only if legal.
320 	 * If we would multicast and it would be illegal, then discard the
321 	 * packet.
322 	 */
323 	switch (wb->type) {
324 	case NO_OUT_MULTICAST:
325 		trace_pkt("skip multicast to %s because impossible",
326 			  naddr_ntoa(ws.to.sin_addr.s_addr));
327 		break;
328 	case NO_OUT_RIPV2:
329 		break;
330 	default:
331 		if (ws.a != 0 && ws.a->type == RIP_AUTH_MD5)
332 			end_md5_auth(wb,ws.a);
333 		if (output(wb->type, &ws.to, ws.ifp, wb->buf,
334 			   ((char *)wb->n - (char*)wb->buf)) < 0
335 		    && ws.ifp != 0)
336 			if_sick(ws.ifp);
337 		ws.npackets++;
338 		break;
339 	}
340 
341 	clr_ws_buf(wb,ws.a);
342 }
343 
344 
345 /* put an entry into the packet
346  */
347 static void
348 supply_out(struct ag_info *ag)
349 {
350 	int i;
351 	naddr mask, v1_mask, dst_h, ddst_h = 0;
352 	struct ws_buf *wb;
353 
354 
355 	/* Skip this route if doing a flash update and it and the routes
356 	 * it aggregates have not changed recently.
357 	 */
358 	if (ag->ag_seqno < update_seqno
359 	    && (ws.state & WS_ST_FLASH))
360 		return;
361 
362 	dst_h = ag->ag_dst_h;
363 	mask = ag->ag_mask;
364 	v1_mask = ripv1_mask_host(htonl(dst_h),
365 				  (ws.state & WS_ST_TO_ON_NET) ? ws.ifp : 0);
366 	i = 0;
367 
368 	/* If we are sending RIPv2 packets that cannot (or must not) be
369 	 * heard by RIPv1 listeners, do not worry about sub- or supernets.
370 	 * Subnets (from other networks) can only be sent via multicast.
371 	 * A pair of subnet routes might have been promoted so that they
372 	 * are legal to send by RIPv1.
373 	 * If RIPv1 is off, use the multicast buffer.
374 	 */
375 	if ((ws.state & WS_ST_RIP2_ALL)
376 	    || ((ag->ag_state & AGS_RIPV2) && v1_mask != mask)) {
377 		/* use the RIPv2-only buffer */
378 		wb = &v2buf;
379 
380 	} else {
381 		/* use the RIPv1-or-RIPv2 buffer */
382 		wb = &v12buf;
383 
384 		/* Convert supernet route into corresponding set of network
385 		 * routes for RIPv1, but leave non-contiguous netmasks
386 		 * to ag_check().
387 		 */
388 		if (v1_mask > mask
389 		    && mask + (mask & -mask) == 0) {
390 			ddst_h = v1_mask & -v1_mask;
391 			i = (v1_mask & ~mask)/ddst_h;
392 
393 			if (i > ws.gen_limit) {
394 				/* Punt if we would have to generate an
395 				 * unreasonable number of routes.
396 				 */
397 				if (TRACECONTENTS)
398 					trace_misc("sending %s-->%s as 1"
399 						   " instead of %d routes",
400 						   addrname(htonl(dst_h), mask,
401 							1),
402 						   naddr_ntoa(ws.to.sin_addr
403 							.s_addr),
404 						   i+1);
405 				i = 0;
406 
407 			} else {
408 				mask = v1_mask;
409 				ws.gen_limit -= i;
410 			}
411 		}
412 	}
413 
414 	do {
415 		wb->n->n_family = RIP_AF_INET;
416 		wb->n->n_dst = htonl(dst_h);
417 		/* If the route is from router-discovery or we are
418 		 * shutting down, admit only a bad metric.
419 		 */
420 		wb->n->n_metric = ((stopint || ag->ag_metric < 1)
421 				   ? HOPCNT_INFINITY
422 				   : ag->ag_metric);
423 		wb->n->n_metric = htonl(wb->n->n_metric);
424 		/* Any non-zero bits in the supposedly unused RIPv1 fields
425 		 * cause the old `routed` to ignore the route.
426 		 * That means the mask and so forth cannot be sent
427 		 * in the hybrid RIPv1/RIPv2 mode.
428 		 */
429 		if (ws.state & WS_ST_RIP2_ALL) {
430 			if (ag->ag_nhop != 0
431 			    && ((ws.state & WS_ST_QUERY)
432 				|| (ag->ag_nhop != ws.ifp->int_addr
433 				    && on_net(ag->ag_nhop,
434 					      ws.ifp->int_net,
435 					      ws.ifp->int_mask))))
436 				wb->n->n_nhop = ag->ag_nhop;
437 			wb->n->n_mask = htonl(mask);
438 			wb->n->n_tag = ag->ag_tag;
439 		}
440 		dst_h += ddst_h;
441 
442 		if (++wb->n >= wb->lim)
443 			supply_write(wb);
444 	} while (i-- != 0);
445 }
446 
447 
448 /* supply one route from the table
449  */
450 /* ARGSUSED */
451 static int
452 walk_supply(struct radix_node *rn,
453 	    struct walkarg *argp UNUSED)
454 {
455 #define RT ((struct rt_entry *)rn)
456 	u_short ags;
457 	char metric, pref;
458 	naddr dst, nhop;
459 	struct rt_spare *rts;
460 	int i;
461 
462 
463 	/* Do not advertise external remote interfaces or passive interfaces.
464 	 */
465 	if ((RT->rt_state & RS_IF)
466 	    && RT->rt_ifp != 0
467 	    && (RT->rt_ifp->int_state & IS_PASSIVE)
468 	    && !(RT->rt_state & RS_MHOME))
469 		return 0;
470 
471 	/* If being quiet about our ability to forward, then
472 	 * do not say anything unless responding to a query,
473 	 * except about our main interface.
474 	 */
475 	if (!supplier && !(ws.state & WS_ST_QUERY)
476 	    && !(RT->rt_state & RS_MHOME))
477 		return 0;
478 
479 	dst = RT->rt_dst;
480 
481 	/* do not collide with the fake default route */
482 	if (dst == RIP_DEFAULT
483 	    && (ws.state & WS_ST_DEFAULT))
484 		return 0;
485 
486 	if (RT->rt_state & RS_NET_SYN) {
487 		if (RT->rt_state & RS_NET_INT) {
488 			/* Do not send manual synthetic network routes
489 			 * into the subnet.
490 			 */
491 			if (on_net(ws.to.sin_addr.s_addr,
492 				   ntohl(dst), RT->rt_mask))
493 				return 0;
494 
495 		} else {
496 			/* Do not send automatic synthetic network routes
497 			 * if they are not needed because no RIPv1 listeners
498 			 * can hear them.
499 			 */
500 			if (ws.state & WS_ST_RIP2_ALL)
501 				return 0;
502 
503 			/* Do not send automatic synthetic network routes to
504 			 * the real subnet.
505 			 */
506 			if (on_net(ws.to.sin_addr.s_addr,
507 				   ntohl(dst), RT->rt_mask))
508 				return 0;
509 		}
510 		nhop = 0;
511 
512 	} else {
513 		/* Advertise the next hop if this is not a route for one
514 		 * of our interfaces and the next hop is on the same
515 		 * network as the target.
516 		 * The final determination is made by supply_out().
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 suppress (into existing network routes)
535 		 * the host routes for the local end of our point-to-point
536 		 * links.
537 		 * If we are suppressing host routes in general, then do so.
538 		 * Avoid advertising host routes onto their own network,
539 		 * where they should be handled by proxy-ARP.
540 		 */
541 		if ((RT->rt_state & RS_LOCAL)
542 		    || ridhosts
543 		    || on_net(dst, ws.to_net, ws.to_mask))
544 			ags |= AGS_SUPPRESS;
545 
546 		/* Aggregate stray host routes into network routes if allowed.
547 		 * We cannot aggregate host routes into small network routes
548 		 * without confusing RIPv1 listeners into thinking the
549 		 * network routes are host routes.
550 		 */
551 		if ((ws.state & WS_ST_AG)
552 		    && !(ws.state & WS_ST_RIP2_ALL))
553 			ags |= AGS_AGGREGATE;
554 
555 	} else {
556 		/* Always suppress network routes into other, existing
557 		 * network routes
558 		 */
559 		ags |= AGS_SUPPRESS;
560 
561 		/* Generate supernets if allowed.
562 		 * If we can be heard by RIPv1 systems, we will
563 		 * later convert back to ordinary nets.
564 		 * This unifies dealing with received supernets.
565 		 */
566 		if ((ws.state & WS_ST_AG)
567 		    && ((RT->rt_state & RS_SUBNET)
568 			|| (ws.state & WS_ST_SUPER_AG)))
569 			ags |= AGS_AGGREGATE;
570 	}
571 
572 	/* Do not send RIPv1 advertisements of subnets to other
573 	 * networks. If possible, multicast them by RIPv2.
574 	 */
575 	if ((RT->rt_state & RS_SUBNET)
576 	    && !(ws.state & WS_ST_RIP2_ALL)
577 	    && !on_net(dst, ws.to_std_net, ws.to_std_mask))
578 		ags |= AGS_RIPV2 | AGS_AGGREGATE;
579 
580 
581 	/* Do not send a route back to where it came from, except in
582 	 * response to a query.  This is "split-horizon".  That means not
583 	 * advertising back to the same network	and so via the same interface.
584 	 *
585 	 * We want to suppress routes that might have been fragmented
586 	 * from this route by a RIPv1 router and sent back to us, and so we
587 	 * cannot forget this route here.  Let the split-horizon route
588 	 * suppress the fragmented routes and then itself be forgotten.
589 	 *
590 	 * Include the routes for both ends of point-to-point interfaces
591 	 * among those suppressed by split-horizon, since the other side
592 	 * should knows them as well as we do.
593 	 *
594 	 * Notice spare routes with the same metric that we are about to
595 	 * advertise, to split the horizon on redundant, inactive paths.
596 	 */
597 	if (ws.ifp != 0
598 	    && !(ws.state & WS_ST_QUERY)
599 	    && (ws.state & WS_ST_TO_ON_NET)
600 	    && (!(RT->rt_state & RS_IF)
601 		|| ws.ifp->int_if_flags & IFF_POINTOPOINT)) {
602 		for (rts = RT->rt_spares, i = NUM_SPARES; i != 0; i--, rts++) {
603 			if (rts->rts_metric > metric
604 			    || rts->rts_ifp != ws.ifp)
605 				continue;
606 
607 			/* If we do not mark the route with AGS_SPLIT_HZ here,
608 			 * it will be poisoned-reverse, or advertised back
609 			 * toward its source with an infinite metric.
610 			 * If we have recently advertised the route with a
611 			 * better metric than we now have, then we should
612 			 * poison-reverse the route before suppressing it for
613 			 * split-horizon.
614 			 *
615 			 * In almost all cases, if there is no spare for the
616 			 * route then it is either old and dead or a brand
617 			 * new route. If it is brand new, there is no need
618 			 * for poison-reverse. If it is old and dead, it
619 			 * is already poisoned.
620 			 */
621 			if (RT->rt_poison_time < now_expire
622 			    || RT->rt_poison_metric >= metric
623 			    || RT->rt_spares[1].rts_gate == 0) {
624 				ags |= AGS_SPLIT_HZ;
625 				ags &= ~AGS_SUPPRESS;
626 			}
627 			metric = HOPCNT_INFINITY;
628 			break;
629 		}
630 	}
631 
632 	/* Keep track of the best metric with which the
633 	 * route has been advertised recently.
634 	 */
635 	if (RT->rt_poison_metric >= metric
636 	    || RT->rt_poison_time < now_expire) {
637 		RT->rt_poison_time = now.tv_sec;
638 		RT->rt_poison_metric = metric;
639 	}
640 
641 	/* Adjust the outgoing metric by the cost of the link.
642 	 * Avoid aggregation when a route is counting to infinity.
643 	 */
644 	pref = RT->rt_poison_metric + ws.metric;
645 	metric += ws.metric;
646 
647 	/* Do not advertise stable routes that will be ignored,
648 	 * unless we are answering a query.
649 	 * If the route recently was advertised with a metric that
650 	 * would have been less than infinity through this interface,
651 	 * we need to continue to advertise it in order to poison it.
652 	 */
653 	if (metric >= HOPCNT_INFINITY) {
654 		if (!(ws.state & WS_ST_QUERY)
655 		    && (pref >= HOPCNT_INFINITY
656 			|| RT->rt_poison_time < now_garbage))
657 			return 0;
658 
659 		metric = HOPCNT_INFINITY;
660 	}
661 
662 	ag_check(dst, RT->rt_mask, 0, nhop, metric, pref,
663 		 RT->rt_seqno, RT->rt_tag, ags, supply_out);
664 	return 0;
665 #undef RT
666 }
667 
668 
669 /* Supply dst with the contents of the routing tables.
670  * If this won't fit in one packet, chop it up into several.
671  */
672 void
673 supply(struct sockaddr_in *dst,
674        struct interface *ifp,		/* output interface */
675        enum output_type type,
676        int flash,			/* 1=flash update */
677        int vers,			/* RIP version */
678        int passwd_ok)			/* OK to include cleartext password */
679 {
680 	struct rt_entry *rt;
681 	int def_metric;
682 
683 
684 	ws.state = 0;
685 	ws.gen_limit = 1024;
686 
687 	ws.to = *dst;
688 	ws.to_std_mask = std_mask(ws.to.sin_addr.s_addr);
689 	ws.to_std_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_std_mask;
690 
691 	if (ifp != 0) {
692 		ws.to_mask = ifp->int_mask;
693 		ws.to_net = ifp->int_net;
694 		if (on_net(ws.to.sin_addr.s_addr, ws.to_net, ws.to_mask))
695 			ws.state |= WS_ST_TO_ON_NET;
696 
697 	} else {
698 		ws.to_mask = ripv1_mask_net(ws.to.sin_addr.s_addr, 0);
699 		ws.to_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_mask;
700 		rt = rtfind(dst->sin_addr.s_addr);
701 		if (rt)
702 			ifp = rt->rt_ifp;
703 	}
704 
705 	ws.npackets = 0;
706 	if (flash)
707 		ws.state |= WS_ST_FLASH;
708 
709 	if ((ws.ifp = ifp) == 0) {
710 		ws.metric = 1;
711 	} else {
712 		/* Adjust the advertised metric by the outgoing interface
713 		 * metric.
714 		 */
715 		ws.metric = ifp->int_metric+1;
716 	}
717 
718 	ripv12_buf.rip.rip_vers = vers;
719 
720 	switch (type) {
721 	case OUT_MULTICAST:
722 		if (ifp->int_if_flags & IFF_MULTICAST)
723 			v2buf.type = OUT_MULTICAST;
724 		else
725 			v2buf.type = NO_OUT_MULTICAST;
726 		v12buf.type = OUT_BROADCAST;
727 		break;
728 
729 	case OUT_QUERY:
730 		ws.state |= WS_ST_QUERY;
731 		/* fall through */
732 	case OUT_BROADCAST:
733 	case OUT_UNICAST:
734 		v2buf.type = (vers == RIPv2) ? type : NO_OUT_RIPV2;
735 		v12buf.type = type;
736 		break;
737 
738 	case NO_OUT_MULTICAST:
739 	case NO_OUT_RIPV2:
740 		break;			/* no output */
741 	}
742 
743 	if (vers == RIPv2) {
744 		/* full RIPv2 only if cannot be heard by RIPv1 listeners */
745 		if (type != OUT_BROADCAST)
746 			ws.state |= WS_ST_RIP2_ALL;
747 		if ((ws.state & WS_ST_QUERY)
748 		    || !(ws.state & WS_ST_TO_ON_NET)) {
749 			ws.state |= (WS_ST_AG | WS_ST_SUPER_AG);
750 		} else if (ifp == 0 || !(ifp->int_state & IS_NO_AG)) {
751 			ws.state |= WS_ST_AG;
752 			if (type != OUT_BROADCAST
753 			    && (ifp == 0
754 				|| !(ifp->int_state & IS_NO_SUPER_AG)))
755 				ws.state |= WS_ST_SUPER_AG;
756 		}
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 	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, 0, {0}, {0}};
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_up(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 (vers == RIPv2
862 			    && !(ifp->int_state  & IS_NO_RIP_MCAST)) {
863 				type = OUT_MULTICAST;
864 			} else {
865 				type = OUT_BROADCAST;
866 			}
867 
868 		} else if (ifp->int_if_flags & IFF_POINTOPOINT) {
869 			/* point-to-point hardware interface */
870 			dst.sin_addr.s_addr = ifp->int_dstaddr;
871 			type = OUT_UNICAST;
872 
873 		} else if (ifp->int_state & IS_REMOTE) {
874 			/* remote interface */
875 			dst.sin_addr.s_addr = ifp->int_addr;
876 			type = OUT_UNICAST;
877 
878 		} else {
879 			/* ATM, HIPPI, etc. */
880 			continue;
881 		}
882 
883 		supply(&dst, ifp, type, flash, vers, 1);
884 	}
885 
886 	update_seqno++;			/* all routes are up to date */
887 }
888 
889 
890 /* Ask for routes
891  * Do it only once to an interface, and not even after the interface
892  * was broken and recovered.
893  */
894 void
895 rip_query(void)
896 {
897 #ifdef _HAVE_SIN_LEN
898 	static struct sockaddr_in dst = {sizeof(dst), AF_INET, 0, {0}, {0}};
899 #else
900 	static struct sockaddr_in dst = {AF_INET};
901 #endif
902 	struct interface *ifp;
903 	struct rip buf;
904 	enum output_type type;
905 
906 
907 	if (rip_sock < 0)
908 		return;
909 
910 	memset(&buf, 0, sizeof(buf));
911 
912 	for (ifp = ifnet; ifp; ifp = ifp->int_next) {
913 		/* Skip interfaces those already queried.
914 		 * Do not ask via interfaces through which we don't
915 		 * accept input.  Do not ask via interfaces that cannot
916 		 * send RIP packets.
917 		 * Do try broken interfaces to see if they have healed.
918 		 */
919 		if (IS_RIP_IN_OFF(ifp->int_state)
920 		    || ifp->int_query_time != NEVER)
921 			continue;
922 
923 		/* skip turned off interfaces */
924 		if (!iff_up(ifp->int_if_flags))
925 			continue;
926 
927 		buf.rip_vers = (ifp->int_state&IS_NO_RIPV1_OUT) ? RIPv2:RIPv1;
928 		buf.rip_cmd = RIPCMD_REQUEST;
929 		buf.rip_nets[0].n_family = RIP_AF_UNSPEC;
930 		buf.rip_nets[0].n_metric = htonl(HOPCNT_INFINITY);
931 
932 		/* Send a RIPv1 query only if allowed and if we will
933 		 * listen to RIPv1 routers.
934 		 */
935 		if ((ifp->int_state & IS_NO_RIPV1_OUT)
936 		    || (ifp->int_state & IS_NO_RIPV1_IN)) {
937 			buf.rip_vers = RIPv2;
938 		} else {
939 			buf.rip_vers = RIPv1;
940 		}
941 
942 		if (ifp->int_if_flags & IFF_BROADCAST) {
943 			/* ordinary, hardware interface */
944 			dst.sin_addr.s_addr = ifp->int_brdaddr;
945 
946 			/* Broadcast RIPv1 queries and RIPv2 queries
947 			 * when the hardware cannot multicast.
948 			 */
949 			if (buf.rip_vers == RIPv2
950 			    && (ifp->int_if_flags & IFF_MULTICAST)
951 			    && !(ifp->int_state  & IS_NO_RIP_MCAST)) {
952 				type = OUT_MULTICAST;
953 			} else {
954 				type = OUT_BROADCAST;
955 			}
956 
957 		} else if (ifp->int_if_flags & IFF_POINTOPOINT) {
958 			/* point-to-point hardware interface */
959 			dst.sin_addr.s_addr = ifp->int_dstaddr;
960 			type = OUT_UNICAST;
961 
962 		} else if (ifp->int_state & IS_REMOTE) {
963 			/* remote interface */
964 			dst.sin_addr.s_addr = ifp->int_addr;
965 			type = OUT_UNICAST;
966 
967 		} else {
968 			/* ATM, HIPPI, etc. */
969 			continue;
970 		}
971 
972 		ifp->int_query_time = now.tv_sec+SUPPLY_INTERVAL;
973 		if (output(type, &dst, ifp, &buf, sizeof(buf)) < 0)
974 			if_sick(ifp);
975 	}
976 }
977