xref: /dragonfly/sbin/routed/output.c (revision 0ca59c34)
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  */
35 
36 #include "defs.h"
37 
38 #if !defined(sgi) && !defined(__NetBSD__)
39 static char sccsid[] __attribute__((unused)) = "@(#)output.c	8.1 (Berkeley) 6/5/93";
40 #elif defined(__NetBSD__)
41 __RCSID("$NetBSD$");
42 #endif
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 in;
105 	int flags;
106 	const char *msg;
107 	int res;
108 	naddr tgt_mcast;
109 	int soc;
110 	int serrno;
111 
112 	in = *dst;
113 	if (in.sin_port == 0)
114 		in.sin_port = htons(RIP_PORT);
115 #ifdef _HAVE_SIN_LEN
116 	if (in.sin_len == 0)
117 		in.sin_len = sizeof(in);
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_PPP_BUG
155 				/* Do not specify the primary interface
156 				 * explicitly if we have the multicast
157 				 * point-to-point kernel bug, since the
158 				 * kernel will do the wrong thing if the
159 				 * local address of a point-to-point link
160 				 * is the same as the address of an ordinary
161 				 * interface.
162 				 */
163 				if (ifp->int_addr == myaddr) {
164 					tgt_mcast = 0;
165 				} else
166 #endif
167 				tgt_mcast = ifp->int_addr;
168 				if (0 > setsockopt(rip_sock,
169 						   IPPROTO_IP, IP_MULTICAST_IF,
170 						   &tgt_mcast,
171 						   sizeof(tgt_mcast))) {
172 					serrno = errno;
173 					LOGERR("setsockopt(rip_sock,"
174 					       "IP_MULTICAST_IF)");
175 					errno = serrno;
176 					ifp = NULL;
177 					return -1;
178 				}
179 				rip_sock_mcast = ifp;
180 			}
181 			in.sin_addr.s_addr = htonl(INADDR_RIP_GROUP);
182 		}
183 		break;
184 
185 	case NO_OUT_MULTICAST:
186 	case NO_OUT_RIPV2:
187 	default:
188 #ifdef DEBUG
189 		abort();
190 #endif
191 		return -1;
192 	}
193 
194 	trace_rip(msg, "to", &in, ifp, buf, size);
195 
196 	res = sendto(soc, buf, size, flags,
197 		     (struct sockaddr *)&in, sizeof(in));
198 	if (res < 0
199 	    && (ifp == NULL || !(ifp->int_state & IS_BROKE))) {
200 		serrno = errno;
201 		msglog("%s sendto(%s%s%s.%d): %s", msg,
202 		       ifp != NULL ? ifp->int_name : "",
203 		       ifp != NULL ? ", " : "",
204 		       inet_ntoa(in.sin_addr),
205 		       ntohs(in.sin_port),
206 		       strerror(errno));
207 		errno = serrno;
208 	}
209 
210 	return res;
211 }
212 
213 
214 /* Find the first key for a packet to send.
215  * Try for a key that is eligible and has not expired, but settle for
216  * the last key if they have all expired.
217  * If no key is ready yet, give up.
218  */
219 struct auth *
220 find_auth(struct interface *ifp)
221 {
222 	struct auth *ap, *res;
223 	int i;
224 
225 
226 	if (ifp == NULL)
227 		return 0;
228 
229 	res = NULL;
230 	ap = ifp->int_auth;
231 	for (i = 0; i < MAX_AUTH_KEYS; i++, ap++) {
232 		/* stop looking after the last key */
233 		if (ap->type == RIP_AUTH_NONE)
234 			break;
235 
236 		/* ignore keys that are not ready yet */
237 		if ((u_long)ap->start > (u_long)clk.tv_sec)
238 			continue;
239 
240 		if ((u_long)ap->end < (u_long)clk.tv_sec) {
241 			/* note best expired password as a fall-back */
242 			if (res == NULL || (u_long)ap->end > (u_long)res->end)
243 				res = ap;
244 			continue;
245 		}
246 
247 		/* note key with the best future */
248 		if (res == NULL || (u_long)res->end < (u_long)ap->end)
249 			res = ap;
250 	}
251 	return res;
252 }
253 
254 
255 void
256 clr_ws_buf(struct ws_buf *wb,
257 	   struct auth *ap)
258 {
259 	struct netauth *na;
260 
261 	wb->lim = wb->base + NETS_LEN;
262 	wb->n = wb->base;
263 	memset(wb->n, 0, NETS_LEN*sizeof(*wb->n));
264 
265 	/* (start to) install authentication if appropriate
266 	 */
267 	if (ap == NULL)
268 		return;
269 
270 	na = (struct netauth*)wb->n;
271 	if (ap->type == RIP_AUTH_PW) {
272 		na->a_family = RIP_AF_AUTH;
273 		na->a_type = RIP_AUTH_PW;
274 		memcpy(na->au.au_pw, ap->key, sizeof(na->au.au_pw));
275 		wb->n++;
276 
277 	} else if (ap->type ==  RIP_AUTH_MD5) {
278 		na->a_family = RIP_AF_AUTH;
279 		na->a_type = RIP_AUTH_MD5;
280 		na->au.a_md5.md5_keyid = ap->keyid;
281 		na->au.a_md5.md5_auth_len = RIP_AUTH_MD5_LEN;
282 		na->au.a_md5.md5_seqno = htonl(clk.tv_sec);
283 		wb->n++;
284 		wb->lim--;		/* make room for trailer */
285 	}
286 }
287 
288 
289 void
290 end_md5_auth(struct ws_buf *wb,
291 	     struct auth *ap)
292 {
293 	struct netauth *na, *na2;
294 	MD5_CTX md5_ctx;
295 	int len;
296 
297 
298 	na = (struct netauth*)wb->base;
299 	na2 = (struct netauth*)wb->n;
300 	len = (char *)na2-(char *)wb->buf;
301 	na2->a_family = RIP_AF_AUTH;
302 	na2->a_type = htons(1);
303 	na->au.a_md5.md5_pkt_len = htons(len);
304 	MD5Init(&md5_ctx);
305 	MD5Update(&md5_ctx, (u_char *)wb->buf, len);
306 	MD5Update(&md5_ctx, ap->key, RIP_AUTH_MD5_LEN);
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 multicast 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 != NULL && 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 != NULL)
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 	dst_h = ag->ag_dst_h;
361 	mask = ag->ag_mask;
362 	v1_mask = ripv1_mask_host(htonl(dst_h),
363 				  (ws.state & WS_ST_TO_ON_NET) ? ws.ifp : 0);
364 	i = 0;
365 
366 	/* If we are sending RIPv2 packets that cannot (or must not) be
367 	 * heard by RIPv1 listeners, do not worry about sub- or supernets.
368 	 * Subnets (from other networks) can only be sent via multicast.
369 	 * A pair of subnet routes might have been promoted so that they
370 	 * are legal to send by RIPv1.
371 	 * If RIPv1 is off, use the multicast buffer.
372 	 */
373 	if ((ws.state & WS_ST_RIP2_ALL)
374 	    || ((ag->ag_state & AGS_RIPV2) && v1_mask != mask)) {
375 		/* use the RIPv2-only buffer */
376 		wb = &v2buf;
377 
378 	} else {
379 		/* use the RIPv1-or-RIPv2 buffer */
380 		wb = &v12buf;
381 
382 		/* Convert supernet route into corresponding set of network
383 		 * routes for RIPv1, but leave non-contiguous netmasks
384 		 * to ag_check().
385 		 */
386 		if (v1_mask > mask
387 		    && mask + (mask & -mask) == 0) {
388 			ddst_h = v1_mask & -v1_mask;
389 			i = (v1_mask & ~mask)/ddst_h;
390 
391 			if (i > ws.gen_limit) {
392 				/* Punt if we would have to generate an
393 				 * unreasonable number of routes.
394 				 */
395 				if (TRACECONTENTS)
396 					trace_misc("sending %s-->%s as 1"
397 						   " instead of %d routes",
398 						   addrname(htonl(dst_h), mask,
399 							1),
400 						   naddr_ntoa(ws.to.sin_addr
401 							.s_addr),
402 						   i+1);
403 				i = 0;
404 
405 			} else {
406 				mask = v1_mask;
407 				ws.gen_limit -= i;
408 			}
409 		}
410 	}
411 
412 	do {
413 		wb->n->n_family = RIP_AF_INET;
414 		wb->n->n_dst = htonl(dst_h);
415 		/* If the route is from router-discovery or we are
416 		 * shutting down, admit only a bad metric.
417 		 */
418 		wb->n->n_metric = ((stopint || ag->ag_metric < 1)
419 				   ? HOPCNT_INFINITY
420 				   : ag->ag_metric);
421 		wb->n->n_metric = htonl(wb->n->n_metric);
422 		/* Any non-zero bits in the supposedly unused RIPv1 fields
423 		 * cause the old `routed` to ignore the route.
424 		 * That means the mask and so forth cannot be sent
425 		 * in the hybrid RIPv1/RIPv2 mode.
426 		 */
427 		if (ws.state & WS_ST_RIP2_ALL) {
428 			if (ag->ag_nhop != 0
429 			    && ((ws.state & WS_ST_QUERY)
430 				|| (ag->ag_nhop != ws.ifp->int_addr
431 				    && on_net(ag->ag_nhop,
432 					      ws.ifp->int_net,
433 					      ws.ifp->int_mask))))
434 				wb->n->n_nhop = ag->ag_nhop;
435 			wb->n->n_mask = htonl(mask);
436 			wb->n->n_tag = ag->ag_tag;
437 		}
438 		dst_h += ddst_h;
439 
440 		if (++wb->n >= wb->lim)
441 			supply_write(wb);
442 	} while (i-- != 0);
443 }
444 
445 
446 /* supply one route from the table
447  */
448 /* ARGSUSED */
449 static int
450 walk_supply(struct radix_node *rn,
451 	    struct walkarg *argp UNUSED)
452 {
453 #define RT ((struct rt_entry *)rn)
454 	u_short ags;
455 	char metric, pref;
456 	naddr dst, nhop;
457 	struct rt_spare *rts;
458 	int i;
459 
460 
461 	/* Do not advertise external remote interfaces or passive interfaces.
462 	 */
463 	if ((RT->rt_state & RS_IF)
464 	    && RT->rt_ifp != 0
465 	    && (RT->rt_ifp->int_state & IS_PASSIVE)
466 	    && !(RT->rt_state & RS_MHOME))
467 		return 0;
468 
469 	/* If being quiet about our ability to forward, then
470 	 * do not say anything unless responding to a query,
471 	 * except about our main interface.
472 	 */
473 	if (!supplier && !(ws.state & WS_ST_QUERY)
474 	    && !(RT->rt_state & RS_MHOME))
475 		return 0;
476 
477 	dst = RT->rt_dst;
478 
479 	/* do not collide with the fake default route */
480 	if (dst == RIP_DEFAULT
481 	    && (ws.state & WS_ST_DEFAULT))
482 		return 0;
483 
484 	if (RT->rt_state & RS_NET_SYN) {
485 		if (RT->rt_state & RS_NET_INT) {
486 			/* Do not send manual synthetic network routes
487 			 * into the subnet.
488 			 */
489 			if (on_net(ws.to.sin_addr.s_addr,
490 				   ntohl(dst), RT->rt_mask))
491 				return 0;
492 
493 		} else {
494 			/* Do not send automatic synthetic network routes
495 			 * if they are not needed because no RIPv1 listeners
496 			 * can hear them.
497 			 */
498 			if (ws.state & WS_ST_RIP2_ALL)
499 				return 0;
500 
501 			/* Do not send automatic synthetic network routes to
502 			 * the real subnet.
503 			 */
504 			if (on_net(ws.to.sin_addr.s_addr,
505 				   ntohl(dst), RT->rt_mask))
506 				return 0;
507 		}
508 		nhop = 0;
509 
510 	} else {
511 		/* Advertise the next hop if this is not a route for one
512 		 * of our interfaces and the next hop is on the same
513 		 * network as the target.
514 		 * The final determination is made by supply_out().
515 		 */
516 		if (!(RT->rt_state & RS_IF)
517 		    && RT->rt_gate != myaddr
518 		    && RT->rt_gate != loopaddr)
519 			nhop = RT->rt_gate;
520 		else
521 			nhop = 0;
522 	}
523 
524 	metric = RT->rt_metric;
525 	ags = 0;
526 
527 	if (RT->rt_state & RS_MHOME) {
528 		/* retain host route of multi-homed servers */
529 		;
530 
531 	} else if (RT_ISHOST(RT)) {
532 		/* We should always suppress (into existing network routes)
533 		 * the host routes for the local end of our point-to-point
534 		 * links.
535 		 * If we are suppressing host routes in general, then do so.
536 		 * Avoid advertising host routes onto their own network,
537 		 * where they should be handled by proxy-ARP.
538 		 */
539 		if ((RT->rt_state & RS_LOCAL)
540 		    || ridhosts
541 		    || on_net(dst, ws.to_net, ws.to_mask))
542 			ags |= AGS_SUPPRESS;
543 
544 		/* Aggregate stray host routes into network routes if allowed.
545 		 * We cannot aggregate host routes into small network routes
546 		 * without confusing RIPv1 listeners into thinking the
547 		 * network routes are host routes.
548 		 */
549 		if ((ws.state & WS_ST_AG)
550 		    && !(ws.state & WS_ST_RIP2_ALL))
551 			ags |= AGS_AGGREGATE;
552 
553 	} else {
554 		/* Always suppress network routes into other, existing
555 		 * network routes
556 		 */
557 		ags |= AGS_SUPPRESS;
558 
559 		/* Generate supernets if allowed.
560 		 * If we can be heard by RIPv1 systems, we will
561 		 * later convert back to ordinary nets.
562 		 * This unifies dealing with received supernets.
563 		 */
564 		if ((ws.state & WS_ST_AG)
565 		    && ((RT->rt_state & RS_SUBNET)
566 			|| (ws.state & WS_ST_SUPER_AG)))
567 			ags |= AGS_AGGREGATE;
568 	}
569 
570 	/* Do not send RIPv1 advertisements of subnets to other
571 	 * networks. If possible, multicast them by RIPv2.
572 	 */
573 	if ((RT->rt_state & RS_SUBNET)
574 	    && !(ws.state & WS_ST_RIP2_ALL)
575 	    && !on_net(dst, ws.to_std_net, ws.to_std_mask))
576 		ags |= AGS_RIPV2 | AGS_AGGREGATE;
577 
578 
579 	/* Do not send a route back to where it came from, except in
580 	 * response to a query.  This is "split-horizon".  That means not
581 	 * advertising back to the same network	and so via the same interface.
582 	 *
583 	 * We want to suppress routes that might have been fragmented
584 	 * from this route by a RIPv1 router and sent back to us, and so we
585 	 * cannot forget this route here.  Let the split-horizon route
586 	 * suppress the fragmented routes and then itself be forgotten.
587 	 *
588 	 * Include the routes for both ends of point-to-point interfaces
589 	 * among those suppressed by split-horizon, since the other side
590 	 * should knows them as well as we do.
591 	 *
592 	 * Notice spare routes with the same metric that we are about to
593 	 * advertise, to split the horizon on redundant, inactive paths.
594 	 */
595 	if (ws.ifp != 0
596 	    && !(ws.state & WS_ST_QUERY)
597 	    && (ws.state & WS_ST_TO_ON_NET)
598 	    && (!(RT->rt_state & RS_IF)
599 		|| ws.ifp->int_if_flags & IFF_POINTOPOINT)) {
600 		for (rts = RT->rt_spares, i = NUM_SPARES; i != 0; i--, rts++) {
601 			if (rts->rts_metric > metric
602 			    || rts->rts_ifp != ws.ifp)
603 				continue;
604 
605 			/* If we do not mark the route with AGS_SPLIT_HZ here,
606 			 * it will be poisoned-reverse, or advertised back
607 			 * toward its source with an infinite metric.
608 			 * If we have recently advertised the route with a
609 			 * better metric than we now have, then we should
610 			 * poison-reverse the route before suppressing it for
611 			 * split-horizon.
612 			 *
613 			 * In almost all cases, if there is no spare for the
614 			 * route then it is either old and dead or a brand
615 			 * new route. If it is brand new, there is no need
616 			 * for poison-reverse. If it is old and dead, it
617 			 * is already poisoned.
618 			 */
619 			if (RT->rt_poison_time < now_expire
620 			    || RT->rt_poison_metric >= metric
621 			    || RT->rt_spares[1].rts_gate == 0) {
622 				ags |= AGS_SPLIT_HZ;
623 				ags &= ~AGS_SUPPRESS;
624 			}
625 			metric = HOPCNT_INFINITY;
626 			break;
627 		}
628 	}
629 
630 	/* Keep track of the best metric with which the
631 	 * route has been advertised recently.
632 	 */
633 	if (RT->rt_poison_metric >= metric
634 	    || RT->rt_poison_time < now_expire) {
635 		RT->rt_poison_time = now.tv_sec;
636 		RT->rt_poison_metric = metric;
637 	}
638 
639 	/* Adjust the outgoing metric by the cost of the link.
640 	 * Avoid aggregation when a route is counting to infinity.
641 	 */
642 	pref = RT->rt_poison_metric + ws.metric;
643 	metric += ws.metric;
644 
645 	/* Do not advertise stable routes that will be ignored,
646 	 * unless we are answering a query.
647 	 * If the route recently was advertised with a metric that
648 	 * would have been less than infinity through this interface,
649 	 * we need to continue to advertise it in order to poison it.
650 	 */
651 	if (metric >= HOPCNT_INFINITY) {
652 		if (!(ws.state & WS_ST_QUERY)
653 		    && (pref >= HOPCNT_INFINITY
654 			|| RT->rt_poison_time < now_garbage))
655 			return 0;
656 
657 		metric = HOPCNT_INFINITY;
658 	}
659 
660 	ag_check(dst, RT->rt_mask, 0, nhop, metric, pref,
661 		 RT->rt_seqno, RT->rt_tag, ags, supply_out);
662 	return 0;
663 #undef RT
664 }
665 
666 
667 /* Supply dst with the contents of the routing tables.
668  * If this won't fit in one packet, chop it up into several.
669  */
670 void
671 supply(struct sockaddr_in *dst,
672        struct interface *ifp,		/* output interface */
673        enum output_type type,
674        int flash,			/* 1=flash update */
675        int vers,			/* RIP version */
676        int passwd_ok)			/* OK to include cleartext password */
677 {
678 	struct rt_entry *rt;
679 	int def_metric;
680 
681 
682 	ws.state = 0;
683 	ws.gen_limit = 1024;
684 
685 	ws.to = *dst;
686 	ws.to_std_mask = std_mask(ws.to.sin_addr.s_addr);
687 	ws.to_std_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_std_mask;
688 
689 	if (ifp != NULL) {
690 		ws.to_mask = ifp->int_mask;
691 		ws.to_net = ifp->int_net;
692 		if (on_net(ws.to.sin_addr.s_addr, ws.to_net, ws.to_mask))
693 			ws.state |= WS_ST_TO_ON_NET;
694 
695 	} else {
696 		ws.to_mask = ripv1_mask_net(ws.to.sin_addr.s_addr, 0);
697 		ws.to_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_mask;
698 		rt = rtfind(dst->sin_addr.s_addr);
699 		if (rt)
700 			ifp = rt->rt_ifp;
701 	}
702 
703 	ws.npackets = 0;
704 	if (flash)
705 		ws.state |= WS_ST_FLASH;
706 
707 	if ((ws.ifp = ifp) == NULL) {
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_MULTICAST:
720 		if (ifp->int_if_flags & IFF_MULTICAST)
721 			v2buf.type = OUT_MULTICAST;
722 		else
723 			v2buf.type = NO_OUT_MULTICAST;
724 		v12buf.type = OUT_BROADCAST;
725 		break;
726 
727 	case OUT_QUERY:
728 		ws.state |= WS_ST_QUERY;
729 		/* fall through */
730 	case OUT_BROADCAST:
731 	case OUT_UNICAST:
732 		v2buf.type = (vers == RIPv2) ? type : NO_OUT_RIPV2;
733 		v12buf.type = type;
734 		break;
735 
736 	case NO_OUT_MULTICAST:
737 	case NO_OUT_RIPV2:
738 		break;			/* no output */
739 	}
740 
741 	if (vers == RIPv2) {
742 		/* full RIPv2 only if cannot be heard by RIPv1 listeners */
743 		if (type != OUT_BROADCAST)
744 			ws.state |= WS_ST_RIP2_ALL;
745 		if ((ws.state & WS_ST_QUERY)
746 		    || !(ws.state & WS_ST_TO_ON_NET)) {
747 			ws.state |= (WS_ST_AG | WS_ST_SUPER_AG);
748 		} else if (ifp == NULL || !(ifp->int_state & IS_NO_AG)) {
749 			ws.state |= WS_ST_AG;
750 			if (type != OUT_BROADCAST
751 			    && (ifp == NULL
752 				|| !(ifp->int_state & IS_NO_SUPER_AG)))
753 				ws.state |= WS_ST_SUPER_AG;
754 		}
755 	}
756 
757 	ws.a = (vers == RIPv2) ? find_auth(ifp) : 0;
758 	if (!passwd_ok && ws.a != NULL && ws.a->type == RIP_AUTH_PW)
759 		ws.a = NULL;
760 	clr_ws_buf(&v12buf,ws.a);
761 	clr_ws_buf(&v2buf,ws.a);
762 
763 	/*  Fake a default route if asked and if there is not already
764 	 * a better, real default route.
765 	 */
766 	if (supplier && (def_metric = ifp->int_d_metric) != 0) {
767 		if (NULL == (rt = rtget(RIP_DEFAULT, 0))
768 		    || rt->rt_metric+ws.metric >= def_metric) {
769 			ws.state |= WS_ST_DEFAULT;
770 			ag_check(0, 0, 0, 0, def_metric, def_metric,
771 				 0, 0, 0, supply_out);
772 		} else {
773 			def_metric = rt->rt_metric+ws.metric;
774 		}
775 
776 		/* If both RIPv2 and the poor-man's router discovery
777 		 * kludge are on, arrange to advertise an extra
778 		 * default route via RIPv1.
779 		 */
780 		if ((ws.state & WS_ST_RIP2_ALL)
781 		    && (ifp->int_state & IS_PM_RDISC)) {
782 			ripv12_buf.rip.rip_vers = RIPv1;
783 			v12buf.n->n_family = RIP_AF_INET;
784 			v12buf.n->n_dst = htonl(RIP_DEFAULT);
785 			v12buf.n->n_metric = htonl(def_metric);
786 			v12buf.n++;
787 		}
788 	}
789 
790 	rn_walktree(rhead, walk_supply, 0);
791 	ag_flush(0,0,supply_out);
792 
793 	/* Flush the packet buffers, provided they are not empty and
794 	 * do not contain only the password.
795 	 */
796 	if (v12buf.n != v12buf.base
797 	    && (v12buf.n > v12buf.base+1
798 		|| v12buf.base->n_family != RIP_AF_AUTH))
799 		supply_write(&v12buf);
800 	if (v2buf.n != v2buf.base
801 	    && (v2buf.n > v2buf.base+1
802 		|| v2buf.base->n_family != RIP_AF_AUTH))
803 		supply_write(&v2buf);
804 
805 	/* If we sent nothing and this is an answer to a query, send
806 	 * an empty buffer.
807 	 */
808 	if (ws.npackets == 0
809 	    && (ws.state & WS_ST_QUERY))
810 		supply_write(&v12buf);
811 }
812 
813 
814 /* send all of the routing table or just do a flash update
815  */
816 void
817 rip_bcast(int flash)
818 {
819 #ifdef _HAVE_SIN_LEN
820 	static struct sockaddr_in dst = {sizeof(dst), AF_INET, 0, {0}, {0}};
821 #else
822 	static struct sockaddr_in dst = {AF_INET};
823 #endif
824 	struct interface *ifp;
825 	enum output_type type;
826 	int vers;
827 	struct timeval rtime;
828 
829 
830 	need_flash = 0;
831 	intvl_random(&rtime, MIN_WAITTIME, MAX_WAITTIME);
832 	no_flash = rtime;
833 	timevaladd(&no_flash, &now);
834 
835 	if (rip_sock < 0)
836 		return;
837 
838 	trace_act("send %s and inhibit dynamic updates for %.3f sec",
839 		  flash ? "dynamic update" : "all routes",
840 		  rtime.tv_sec + ((float)rtime.tv_usec)/1000000.0);
841 
842 	for (ifp = ifnet; ifp != NULL; ifp = ifp->int_next) {
843 		/* Skip interfaces not doing RIP.
844 		 * Do try broken interfaces to see if they have healed.
845 		 */
846 		if (IS_RIP_OUT_OFF(ifp->int_state))
847 			continue;
848 
849 		/* skip turned off interfaces */
850 		if (!iff_up(ifp->int_if_flags))
851 			continue;
852 
853 		vers = (ifp->int_state & IS_NO_RIPV1_OUT) ? RIPv2 : RIPv1;
854 
855 		if (ifp->int_if_flags & IFF_BROADCAST) {
856 			/* ordinary, hardware interface */
857 			dst.sin_addr.s_addr = ifp->int_brdaddr;
858 
859 			if (vers == RIPv2
860 			    && !(ifp->int_state  & IS_NO_RIP_MCAST)) {
861 				type = OUT_MULTICAST;
862 			} else {
863 				type = OUT_BROADCAST;
864 			}
865 
866 		} else if (ifp->int_if_flags & IFF_POINTOPOINT) {
867 			/* point-to-point hardware interface */
868 			dst.sin_addr.s_addr = ifp->int_dstaddr;
869 			type = OUT_UNICAST;
870 
871 		} else if (ifp->int_state & IS_REMOTE) {
872 			/* remote interface */
873 			dst.sin_addr.s_addr = ifp->int_addr;
874 			type = OUT_UNICAST;
875 
876 		} else {
877 			/* ATM, HIPPI, etc. */
878 			continue;
879 		}
880 
881 		supply(&dst, ifp, type, flash, vers, 1);
882 	}
883 
884 	update_seqno++;			/* all routes are up to date */
885 }
886 
887 
888 /* Ask for routes
889  * Do it only once to an interface, and not even after the interface
890  * was broken and recovered.
891  */
892 void
893 rip_query(void)
894 {
895 #ifdef _HAVE_SIN_LEN
896 	static struct sockaddr_in dst = {sizeof(dst), AF_INET, 0, {0}, {0}};
897 #else
898 	static struct sockaddr_in dst = {AF_INET};
899 #endif
900 	struct interface *ifp;
901 	struct rip buf;
902 	enum output_type type;
903 
904 
905 	if (rip_sock < 0)
906 		return;
907 
908 	memset(&buf, 0, sizeof(buf));
909 
910 	for (ifp = ifnet; ifp; ifp = ifp->int_next) {
911 		/* Skip interfaces those already queried.
912 		 * Do not ask via interfaces through which we don't
913 		 * accept input.  Do not ask via interfaces that cannot
914 		 * send RIP packets.
915 		 * Do try broken interfaces to see if they have healed.
916 		 */
917 		if (IS_RIP_IN_OFF(ifp->int_state)
918 		    || ifp->int_query_time != NEVER)
919 			continue;
920 
921 		/* skip turned off interfaces */
922 		if (!iff_up(ifp->int_if_flags))
923 			continue;
924 
925 		buf.rip_vers = (ifp->int_state&IS_NO_RIPV1_OUT) ? RIPv2:RIPv1;
926 		buf.rip_cmd = RIPCMD_REQUEST;
927 		buf.rip_nets[0].n_family = RIP_AF_UNSPEC;
928 		buf.rip_nets[0].n_metric = htonl(HOPCNT_INFINITY);
929 
930 		/* Send a RIPv1 query only if allowed and if we will
931 		 * listen to RIPv1 routers.
932 		 */
933 		if ((ifp->int_state & IS_NO_RIPV1_OUT)
934 		    || (ifp->int_state & IS_NO_RIPV1_IN)) {
935 			buf.rip_vers = RIPv2;
936 		} else {
937 			buf.rip_vers = RIPv1;
938 		}
939 
940 		if (ifp->int_if_flags & IFF_BROADCAST) {
941 			/* ordinary, hardware interface */
942 			dst.sin_addr.s_addr = ifp->int_brdaddr;
943 
944 			/* Broadcast RIPv1 queries and RIPv2 queries
945 			 * when the hardware cannot multicast.
946 			 */
947 			if (buf.rip_vers == RIPv2
948 			    && (ifp->int_if_flags & IFF_MULTICAST)
949 			    && !(ifp->int_state  & IS_NO_RIP_MCAST)) {
950 				type = OUT_MULTICAST;
951 			} else {
952 				type = OUT_BROADCAST;
953 			}
954 
955 		} else if (ifp->int_if_flags & IFF_POINTOPOINT) {
956 			/* point-to-point hardware interface */
957 			dst.sin_addr.s_addr = ifp->int_dstaddr;
958 			type = OUT_UNICAST;
959 
960 		} else if (ifp->int_state & IS_REMOTE) {
961 			/* remote interface */
962 			dst.sin_addr.s_addr = ifp->int_addr;
963 			type = OUT_UNICAST;
964 
965 		} else {
966 			/* ATM, HIPPI, etc. */
967 			continue;
968 		}
969 
970 		ifp->int_query_time = now.tv_sec+SUPPLY_INTERVAL;
971 		if (output(type, &dst, ifp, &buf, sizeof(buf)) < 0)
972 			if_sick(ifp);
973 	}
974 }
975