1/*	$NetBSD: output.c,v 1.24 2006/03/21 21:50:44 christos 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 acknowledgment:
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#include "defs.h"
37
38#ifdef __NetBSD__
39__RCSID("$NetBSD: output.c,v 1.24 2006/03/21 21:50:44 christos Exp $");
40#elif defined(__FreeBSD__)
41__RCSID("$FreeBSD$");
42#else
43__RCSID("Revision: 2.27 ");
44#ident "Revision: 2.27 "
45#endif
46
47
48u_int update_seqno;
49
50
51/* walk the tree of routes with this for output
52 */
53struct {
54	struct sockaddr_in to;
55	naddr	to_mask;
56	naddr	to_net;
57	naddr	to_std_mask;
58	naddr	to_std_net;
59	struct interface *ifp;		/* usually output interface */
60	struct auth *a;
61	char	metric;			/* adjust metrics by interface */
62	int	npackets;
63	int	gen_limit;
64	u_int	state;
65#define	    WS_ST_FLASH	    0x001	/* send only changed routes */
66#define	    WS_ST_RIP2_ALL  0x002	/* send full featured RIPv2 */
67#define	    WS_ST_AG	    0x004	/* ok to aggregate subnets */
68#define	    WS_ST_SUPER_AG  0x008	/* ok to aggregate networks */
69#define	    WS_ST_QUERY	    0x010	/* responding to a query */
70#define	    WS_ST_TO_ON_NET 0x020	/* sending onto one of our nets */
71#define	    WS_ST_DEFAULT   0x040	/* faking a default */
72} ws;
73
74/* A buffer for what can be heard by both RIPv1 and RIPv2 listeners */
75struct ws_buf v12buf;
76union pkt_buf ripv12_buf;
77
78/* Another for only RIPv2 listeners */
79struct ws_buf v2buf;
80union pkt_buf rip_v2_buf;
81
82
83
84void
85bufinit(void)
86{
87	ripv12_buf.rip.rip_cmd = RIPCMD_RESPONSE;
88	v12buf.buf = &ripv12_buf.rip;
89	v12buf.base = &v12buf.buf->rip_nets[0];
90
91	rip_v2_buf.rip.rip_cmd = RIPCMD_RESPONSE;
92	rip_v2_buf.rip.rip_vers = RIPv2;
93	v2buf.buf = &rip_v2_buf.rip;
94	v2buf.base = &v2buf.buf->rip_nets[0];
95}
96
97
98/* Send the contents of the global buffer via the non-multicast socket
99 */
100int					/* <0 on failure */
101output(enum output_type type,
102       struct sockaddr_in *dst,		/* send to here */
103       struct interface *ifp,
104       struct rip *buf,
105       int size)			/* this many bytes */
106{
107	struct sockaddr_in osin;
108	int flags;
109	const char *msg;
110	int res;
111	naddr tgt_mcast;
112	int soc;
113	int serrno;
114
115	osin = *dst;
116	if (osin.sin_port == 0)
117		osin.sin_port = htons(RIP_PORT);
118#ifdef _HAVE_SIN_LEN
119	if (osin.sin_len == 0)
120		osin.sin_len = sizeof(osin);
121#endif
122
123	soc = rip_sock;
124	flags = 0;
125
126	switch (type) {
127	case OUT_QUERY:
128		msg = "Answer Query";
129		if (soc < 0)
130			soc = ifp->int_rip_sock;
131		break;
132	case OUT_UNICAST:
133		msg = "Send";
134		if (soc < 0)
135			soc = ifp->int_rip_sock;
136		flags = MSG_DONTROUTE;
137		break;
138	case OUT_BROADCAST:
139		if (ifp->int_if_flags & IFF_POINTOPOINT) {
140			msg = "Send";
141		} else {
142			msg = "Send bcast";
143		}
144		flags = MSG_DONTROUTE;
145		break;
146	case OUT_MULTICAST:
147		if ((ifp->int_if_flags & IFF_POINTOPOINT)
148		    && !(ifp->int_if_flags & IFF_MULTICAST)) {
149			msg = "Send pt-to-pt";
150		} else if (ifp->int_state & IS_DUP) {
151			trace_act("abort multicast output via %s"
152				  " with duplicate address",
153				  ifp->int_name);
154			return 0;
155		} else {
156			msg = "Send mcast";
157			if (rip_sock_mcast != ifp) {
158#ifdef MCAST_IFINDEX
159				/* specify ifindex */
160				tgt_mcast = htonl(ifp->int_index);
161#else
162#ifdef MCAST_PPP_BUG
163				/* Do not specify the primary interface
164				 * explicitly if we have the multicast
165				 * point-to-point kernel bug, since the
166				 * kernel will do the wrong thing if the
167				 * local address of a point-to-point link
168				 * is the same as the address of an ordinary
169				 * interface.
170				 */
171				if (ifp->int_addr == myaddr) {
172					tgt_mcast = 0;
173				} else
174#endif
175				tgt_mcast = ifp->int_addr;
176#endif
177				if (0 > setsockopt(rip_sock,
178						   IPPROTO_IP, IP_MULTICAST_IF,
179						   &tgt_mcast,
180						   sizeof(tgt_mcast))) {
181					serrno = errno;
182					LOGERR("setsockopt(rip_sock,"
183					       "IP_MULTICAST_IF)");
184					errno = serrno;
185					ifp = 0;
186					return -1;
187				}
188				rip_sock_mcast = ifp;
189			}
190			osin.sin_addr.s_addr = htonl(INADDR_RIP_GROUP);
191		}
192		break;
193
194	case NO_OUT_MULTICAST:
195	case NO_OUT_RIPV2:
196	default:
197#ifdef DEBUG
198		abort();
199#endif
200		return -1;
201	}
202
203	trace_rip(msg, "to", &osin, ifp, buf, size);
204
205	res = sendto(soc, buf, size, flags,
206		     (struct sockaddr *)&osin, sizeof(osin));
207	if (res < 0
208	    && (ifp == 0 || !(ifp->int_state & IS_BROKE))) {
209		serrno = errno;
210		msglog("%s sendto(%s%s%s.%d): %s", msg,
211		       ifp != 0 ? ifp->int_name : "",
212		       ifp != 0 ? ", " : "",
213		       inet_ntoa(osin.sin_addr),
214		       ntohs(osin.sin_port),
215		       strerror(errno));
216		errno = serrno;
217	}
218
219	return res;
220}
221
222
223/* Find the first key for a packet to send.
224 * Try for a key that is eligible and has not expired, but settle for
225 * the last key if they have all expired.
226 * If no key is ready yet, give up.
227 */
228struct auth *
229find_auth(struct interface *ifp)
230{
231	struct auth *ap, *res;
232	int i;
233
234
235	if (ifp == 0)
236		return 0;
237
238	res = 0;
239	ap = ifp->int_auth;
240	for (i = 0; i < MAX_AUTH_KEYS; i++, ap++) {
241		/* stop looking after the last key */
242		if (ap->type == RIP_AUTH_NONE)
243			break;
244
245		/* ignore keys that are not ready yet */
246		if ((u_long)ap->start > (u_long)clk.tv_sec)
247			continue;
248
249		if ((u_long)ap->end < (u_long)clk.tv_sec) {
250			/* note best expired password as a fall-back */
251			if (res == 0 || (u_long)ap->end > (u_long)res->end)
252				res = ap;
253			continue;
254		}
255
256		/* note key with the best future */
257		if (res == 0 || (u_long)res->end < (u_long)ap->end)
258			res = ap;
259	}
260	return res;
261}
262
263
264void
265clr_ws_buf(struct ws_buf *wb,
266	   struct auth *ap)
267{
268	struct netauth *na;
269
270	wb->lim = wb->base + NETS_LEN;
271	wb->n = wb->base;
272	memset(wb->n, 0, NETS_LEN*sizeof(*wb->n));
273
274	/* (start to) install authentication if appropriate
275	 */
276	if (ap == 0)
277		return;
278
279	na = (struct netauth*)wb->n;
280	if (ap->type == RIP_AUTH_PW) {
281		na->a_family = RIP_AF_AUTH;
282		na->a_type = RIP_AUTH_PW;
283		memcpy(na->au.au_pw, ap->key, sizeof(na->au.au_pw));
284		wb->n++;
285
286	} else if (ap->type ==  RIP_AUTH_MD5) {
287		na->a_family = RIP_AF_AUTH;
288		na->a_type = RIP_AUTH_MD5;
289		na->au.a_md5.md5_keyid = ap->keyid;
290		na->au.a_md5.md5_auth_len = RIP_AUTH_MD5_KEY_LEN;
291		na->au.a_md5.md5_seqno = htonl(clk.tv_sec);
292		wb->n++;
293		wb->lim--;		/* make room for trailer */
294	}
295}
296
297
298void
299end_md5_auth(struct ws_buf *wb,
300	     struct auth *ap)
301{
302	struct netauth *na, *na2;
303	MD5_CTX md5_ctx;
304	int len;
305
306
307	na = (struct netauth*)wb->base;
308	na2 = (struct netauth*)wb->n;
309	len = (char *)na2-(char *)wb->buf;
310	na2->a_family = RIP_AF_AUTH;
311	na2->a_type = htons(1);
312	na->au.a_md5.md5_pkt_len = htons(len);
313	MD5Init(&md5_ctx);
314	MD5Update(&md5_ctx, (u_char *)wb->buf, len + RIP_AUTH_MD5_HASH_XTRA);
315	MD5Update(&md5_ctx, ap->key, RIP_AUTH_MD5_KEY_LEN);
316	MD5Final(na2->au.au_pw, &md5_ctx);
317	wb->n++;
318}
319
320
321/* Send the buffer
322 */
323static void
324supply_write(struct ws_buf *wb)
325{
326	/* Output multicast only if legal.
327	 * If we would multicast and it would be illegal, then discard the
328	 * packet.
329	 */
330	switch (wb->type) {
331	case NO_OUT_MULTICAST:
332		trace_pkt("skip multicast to %s because impossible",
333			  naddr_ntoa(ws.to.sin_addr.s_addr));
334		break;
335	case NO_OUT_RIPV2:
336		break;
337	default:
338		if (ws.a != 0 && ws.a->type == RIP_AUTH_MD5)
339			end_md5_auth(wb,ws.a);
340		if (output(wb->type, &ws.to, ws.ifp, wb->buf,
341			   ((char *)wb->n - (char*)wb->buf)) < 0
342		    && ws.ifp != 0)
343			if_sick(ws.ifp);
344		ws.npackets++;
345		break;
346	}
347
348	clr_ws_buf(wb,ws.a);
349}
350
351
352/* put an entry into the packet
353 */
354static void
355supply_out(struct ag_info *ag)
356{
357	int i;
358	naddr mask, v1_mask, dst_h, ddst_h = 0;
359	struct ws_buf *wb;
360
361
362	/* Skip this route if doing a flash update and it and the routes
363	 * it aggregates have not changed recently.
364	 */
365	if (ag->ag_seqno < update_seqno
366	    && (ws.state & WS_ST_FLASH))
367		return;
368
369	dst_h = ag->ag_dst_h;
370	mask = ag->ag_mask;
371	v1_mask = ripv1_mask_host(htonl(dst_h),
372				  (ws.state & WS_ST_TO_ON_NET) ? ws.ifp : 0);
373	i = 0;
374
375	/* If we are sending RIPv2 packets that cannot (or must not) be
376	 * heard by RIPv1 listeners, do not worry about sub- or supernets.
377	 * Subnets (from other networks) can only be sent via multicast.
378	 * A pair of subnet routes might have been promoted so that they
379	 * are legal to send by RIPv1.
380	 * If RIPv1 is off, use the multicast buffer.
381	 */
382	if ((ws.state & WS_ST_RIP2_ALL)
383	    || ((ag->ag_state & AGS_RIPV2) && v1_mask != mask)) {
384		/* use the RIPv2-only buffer */
385		wb = &v2buf;
386
387	} else {
388		/* use the RIPv1-or-RIPv2 buffer */
389		wb = &v12buf;
390
391		/* Convert supernet route into corresponding set of network
392		 * routes for RIPv1, but leave non-contiguous netmasks
393		 * to ag_check().
394		 */
395		if (v1_mask > mask
396		    && mask + (mask & -mask) == 0) {
397			ddst_h = v1_mask & -v1_mask;
398			i = (v1_mask & ~mask)/ddst_h;
399
400			if (i > ws.gen_limit) {
401				/* Punt if we would have to generate an
402				 * unreasonable number of routes.
403				 */
404				if (TRACECONTENTS)
405					trace_misc("sending %s-->%s as 1"
406						   " instead of %d routes",
407						   addrname(htonl(dst_h), mask,
408							1),
409						   naddr_ntoa(ws.to.sin_addr
410							.s_addr),
411						   i+1);
412				i = 0;
413
414			} else {
415				mask = v1_mask;
416				ws.gen_limit -= i;
417			}
418		}
419	}
420
421	do {
422		wb->n->n_family = RIP_AF_INET;
423		wb->n->n_dst = htonl(dst_h);
424		/* If the route is from router-discovery or we are
425		 * shutting down, admit only a bad metric.
426		 */
427		wb->n->n_metric = ((stopint || ag->ag_metric < 1)
428				   ? HOPCNT_INFINITY
429				   : ag->ag_metric);
430		wb->n->n_metric = htonl(wb->n->n_metric);
431		/* Any non-zero bits in the supposedly unused RIPv1 fields
432		 * cause the old `routed` to ignore the route.
433		 * That means the mask and so forth cannot be sent
434		 * in the hybrid RIPv1/RIPv2 mode.
435		 */
436		if (ws.state & WS_ST_RIP2_ALL) {
437			if (ag->ag_nhop != 0
438			    && ((ws.state & WS_ST_QUERY)
439				|| (ag->ag_nhop != ws.ifp->int_addr
440				    && on_net(ag->ag_nhop,
441					      ws.ifp->int_net,
442					      ws.ifp->int_mask))))
443				wb->n->n_nhop = ag->ag_nhop;
444			wb->n->n_mask = htonl(mask);
445			wb->n->n_tag = ag->ag_tag;
446		}
447		dst_h += ddst_h;
448
449		if (++wb->n >= wb->lim)
450			supply_write(wb);
451	} while (i-- != 0);
452}
453
454
455/* supply one route from the table
456 */
457/* ARGSUSED */
458static int
459walk_supply(struct radix_node *rn,
460	    struct walkarg *argp UNUSED)
461{
462#define RT ((struct rt_entry *)rn)
463	u_short ags;
464	char metric, pref;
465	naddr dst, nhop;
466	struct rt_spare *rts;
467	int i;
468
469
470	/* Do not advertise external remote interfaces or passive interfaces.
471	 */
472	if ((RT->rt_state & RS_IF)
473	    && RT->rt_ifp != 0
474	    && (RT->rt_ifp->int_state & IS_PASSIVE)
475	    && !(RT->rt_state & RS_MHOME))
476		return 0;
477
478	/* If being quiet about our ability to forward, then
479	 * do not say anything unless responding to a query,
480	 * except about our main interface.
481	 */
482	if (!supplier && !(ws.state & WS_ST_QUERY)
483	    && !(RT->rt_state & RS_MHOME))
484		return 0;
485
486	dst = RT->rt_dst;
487
488	/* do not collide with the fake default route */
489	if (dst == RIP_DEFAULT
490	    && (ws.state & WS_ST_DEFAULT))
491		return 0;
492
493	if (RT->rt_state & RS_NET_SYN) {
494		if (RT->rt_state & RS_NET_INT) {
495			/* Do not send manual synthetic network routes
496			 * into the subnet.
497			 */
498			if (on_net(ws.to.sin_addr.s_addr,
499				   ntohl(dst), RT->rt_mask))
500				return 0;
501
502		} else {
503			/* Do not send automatic synthetic network routes
504			 * if they are not needed because no RIPv1 listeners
505			 * can hear them.
506			 */
507			if (ws.state & WS_ST_RIP2_ALL)
508				return 0;
509
510			/* Do not send automatic synthetic network routes to
511			 * the real subnet.
512			 */
513			if (on_net(ws.to.sin_addr.s_addr,
514				   ntohl(dst), RT->rt_mask))
515				return 0;
516		}
517		nhop = 0;
518
519	} else {
520		/* Advertise the next hop if this is not a route for one
521		 * of our interfaces and the next hop is on the same
522		 * network as the target.
523		 * The final determination is made by supply_out().
524		 */
525		if (!(RT->rt_state & RS_IF)
526		    && RT->rt_gate != myaddr
527		    && RT->rt_gate != loopaddr)
528			nhop = RT->rt_gate;
529		else
530			nhop = 0;
531	}
532
533	metric = RT->rt_metric;
534	ags = 0;
535
536	if (RT->rt_state & RS_MHOME) {
537		/* retain host route of multi-homed servers */
538		;
539
540	} else if (RT_ISHOST(RT)) {
541		/* We should always suppress (into existing network routes)
542		 * the host routes for the local end of our point-to-point
543		 * links.
544		 * If we are suppressing host routes in general, then do so.
545		 * Avoid advertising host routes onto their own network,
546		 * where they should be handled by proxy-ARP.
547		 */
548		if ((RT->rt_state & RS_LOCAL)
549		    || ridhosts
550		    || on_net(dst, ws.to_net, ws.to_mask))
551			ags |= AGS_SUPPRESS;
552
553		/* Aggregate stray host routes into network routes if allowed.
554		 * We cannot aggregate host routes into small network routes
555		 * without confusing RIPv1 listeners into thinking the
556		 * network routes are host routes.
557		 */
558		if ((ws.state & WS_ST_AG) && (ws.state & WS_ST_RIP2_ALL))
559			ags |= AGS_AGGREGATE;
560
561	} else {
562		/* Always suppress network routes into other, existing
563		 * network routes
564		 */
565		ags |= AGS_SUPPRESS;
566
567		/* Generate supernets if allowed.
568		 * If we can be heard by RIPv1 systems, we will
569		 * later convert back to ordinary nets.
570		 * This unifies dealing with received supernets.
571		 */
572		if ((ws.state & WS_ST_AG)
573		    && ((RT->rt_state & RS_SUBNET)
574			|| (ws.state & WS_ST_SUPER_AG)))
575			ags |= AGS_AGGREGATE;
576	}
577
578	/* Do not send RIPv1 advertisements of subnets to other
579	 * networks. If possible, multicast them by RIPv2.
580	 */
581	if ((RT->rt_state & RS_SUBNET)
582	    && !(ws.state & WS_ST_RIP2_ALL)
583	    && !on_net(dst, ws.to_std_net, ws.to_std_mask))
584		ags |= AGS_RIPV2 | AGS_AGGREGATE;
585
586
587	/* Do not send a route back to where it came from, except in
588	 * response to a query.  This is "split-horizon".  That means not
589	 * advertising back to the same network	and so via the same interface.
590	 *
591	 * We want to suppress routes that might have been fragmented
592	 * from this route by a RIPv1 router and sent back to us, and so we
593	 * cannot forget this route here.  Let the split-horizon route
594	 * suppress the fragmented routes and then itself be forgotten.
595	 *
596	 * Include the routes for both ends of point-to-point interfaces
597	 * among those suppressed by split-horizon, since the other side
598	 * should knows them as well as we do.
599	 *
600	 * Notice spare routes with the same metric that we are about to
601	 * advertise, to split the horizon on redundant, inactive paths.
602	 *
603	 * Do not suppress advertisements of interface-related addresses on
604	 * non-point-to-point interfaces.  This ensures that we have something
605	 * to say every 30 seconds to help detect broken Ethernets or
606	 * other interfaces where one packet every 30 seconds costs nothing.
607	 */
608	if (ws.ifp != 0
609	    && !(ws.state & WS_ST_QUERY)
610	    && (ws.state & WS_ST_TO_ON_NET)
611	    && (!(RT->rt_state & RS_IF)
612		|| ws.ifp->int_if_flags & IFF_POINTOPOINT)) {
613		for (rts = RT->rt_spares, i = NUM_SPARES; i != 0; i--, rts++) {
614			if (rts->rts_metric > metric
615			    || rts->rts_ifp != ws.ifp)
616				continue;
617
618			/* If we do not mark the route with AGS_SPLIT_HZ here,
619			 * it will be poisoned-reverse, or advertised back
620			 * toward its source with an infinite metric.
621			 * If we have recently advertised the route with a
622			 * better metric than we now have, then we should
623			 * poison-reverse the route before suppressing it for
624			 * split-horizon.
625			 *
626			 * In almost all cases, if there is no spare for the
627			 * route then it is either old and dead or a brand
628			 * new route. If it is brand new, there is no need
629			 * for poison-reverse. If it is old and dead, it
630			 * is already poisoned.
631			 */
632			if (RT->rt_poison_time < now_expire
633			    || RT->rt_poison_metric >= metric
634			    || RT->rt_spares[1].rts_gate == 0) {
635				ags |= AGS_SPLIT_HZ;
636				ags &= ~AGS_SUPPRESS;
637			}
638			metric = HOPCNT_INFINITY;
639			break;
640		}
641	}
642
643	/* Keep track of the best metric with which the
644	 * route has been advertised recently.
645	 */
646	if (RT->rt_poison_metric >= metric
647	    || RT->rt_poison_time < now_expire) {
648		RT->rt_poison_time = now.tv_sec;
649		RT->rt_poison_metric = metric;
650	}
651
652	/* Adjust the outgoing metric by the cost of the link.
653	 * Avoid aggregation when a route is counting to infinity.
654	 */
655	pref = RT->rt_poison_metric + ws.metric;
656	metric += ws.metric;
657
658	/* Do not advertise stable routes that will be ignored,
659	 * unless we are answering a query.
660	 * If the route recently was advertised with a metric that
661	 * would have been less than infinity through this interface,
662	 * we need to continue to advertise it in order to poison it.
663	 */
664	if (metric >= HOPCNT_INFINITY) {
665		if (!(ws.state & WS_ST_QUERY)
666		    && (pref >= HOPCNT_INFINITY
667			|| RT->rt_poison_time < now_garbage))
668			return 0;
669
670		metric = HOPCNT_INFINITY;
671	}
672
673	ag_check(dst, RT->rt_mask, 0, nhop, metric, pref,
674		 RT->rt_seqno, RT->rt_tag, ags, supply_out);
675	return 0;
676#undef RT
677}
678
679
680/* Supply dst with the contents of the routing tables.
681 * If this won't fit in one packet, chop it up into several.
682 */
683void
684supply(struct sockaddr_in *dst,
685       struct interface *ifp,		/* output interface */
686       enum output_type type,
687       int flash,			/* 1=flash update */
688       int vers,			/* RIP version */
689       int passwd_ok)			/* OK to include cleartext password */
690{
691	struct rt_entry *rt;
692	int def_metric;
693
694
695	ws.state = 0;
696	ws.gen_limit = 1024;
697
698	ws.to = *dst;
699	ws.to_std_mask = std_mask(ws.to.sin_addr.s_addr);
700	ws.to_std_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_std_mask;
701
702	if (ifp != 0) {
703		ws.to_mask = ifp->int_mask;
704		ws.to_net = ifp->int_net;
705		if (on_net(ws.to.sin_addr.s_addr, ws.to_net, ws.to_mask))
706			ws.state |= WS_ST_TO_ON_NET;
707
708	} else {
709		ws.to_mask = ripv1_mask_net(ws.to.sin_addr.s_addr, 0);
710		ws.to_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_mask;
711		rt = rtfind(dst->sin_addr.s_addr);
712		if (rt)
713			ifp = rt->rt_ifp;
714	}
715
716	ws.npackets = 0;
717	if (flash)
718		ws.state |= WS_ST_FLASH;
719
720	if ((ws.ifp = ifp) == 0) {
721		ws.metric = 1;
722	} else {
723		/* Adjust the advertised metric by the outgoing interface
724		 * metric.
725		 */
726		ws.metric = ifp->int_metric + 1 + ifp->int_adj_outmetric;
727	}
728
729	ripv12_buf.rip.rip_vers = vers;
730
731	switch (type) {
732	case OUT_MULTICAST:
733		if (ifp != NULL && ifp->int_if_flags & IFF_MULTICAST)
734			v2buf.type = OUT_MULTICAST;
735		else
736			v2buf.type = NO_OUT_MULTICAST;
737		v12buf.type = OUT_BROADCAST;
738		break;
739
740	case OUT_QUERY:
741		ws.state |= WS_ST_QUERY;
742		/* fall through */
743	case OUT_BROADCAST:
744	case OUT_UNICAST:
745		v2buf.type = (vers == RIPv2) ? type : NO_OUT_RIPV2;
746		v12buf.type = type;
747		break;
748
749	case NO_OUT_MULTICAST:
750	case NO_OUT_RIPV2:
751		break;			/* no output */
752	}
753
754	if (vers == RIPv2) {
755		/* full RIPv2 only if cannot be heard by RIPv1 listeners */
756		if (type != OUT_BROADCAST)
757			ws.state |= WS_ST_RIP2_ALL;
758		if ((ws.state & WS_ST_QUERY)
759		    || !(ws.state & WS_ST_TO_ON_NET)) {
760			ws.state |= (WS_ST_AG | WS_ST_SUPER_AG);
761		} else if (ifp == 0 || !(ifp->int_state & IS_NO_AG)) {
762			ws.state |= WS_ST_AG;
763			if (type != OUT_BROADCAST
764			    && (ifp == 0
765				|| !(ifp->int_state & IS_NO_SUPER_AG)))
766				ws.state |= WS_ST_SUPER_AG;
767		}
768	}
769
770	ws.a = (vers == RIPv2) ? find_auth(ifp) : 0;
771	if (!passwd_ok && ws.a != 0 && ws.a->type == RIP_AUTH_PW)
772		ws.a = 0;
773	clr_ws_buf(&v12buf,ws.a);
774	clr_ws_buf(&v2buf,ws.a);
775
776	/*  Fake a default route if asked and if there is not already
777	 * a better, real default route.
778	 */
779	if (supplier && ifp && (def_metric = ifp->int_d_metric) != 0) {
780		if (0 == (rt = rtget(RIP_DEFAULT, 0))
781		    || rt->rt_metric+ws.metric >= def_metric) {
782			ws.state |= WS_ST_DEFAULT;
783			ag_check(0, 0, 0, 0, def_metric, def_metric,
784				 0, 0, 0, supply_out);
785		} else {
786			def_metric = rt->rt_metric+ws.metric;
787		}
788
789		/* If both RIPv2 and the poor-man's router discovery
790		 * kludge are on, arrange to advertise an extra
791		 * default route via RIPv1.
792		 */
793		if ((ws.state & WS_ST_RIP2_ALL)
794		    && (ifp->int_state & IS_PM_RDISC)) {
795			ripv12_buf.rip.rip_vers = RIPv1;
796			v12buf.n->n_family = RIP_AF_INET;
797			v12buf.n->n_dst = htonl(RIP_DEFAULT);
798			v12buf.n->n_metric = htonl(def_metric);
799			v12buf.n++;
800		}
801	}
802
803	(void)rn_walktree(rhead, walk_supply, 0);
804	ag_flush(0,0,supply_out);
805
806	/* Flush the packet buffers, provided they are not empty and
807	 * do not contain only the password.
808	 */
809	if (v12buf.n != v12buf.base
810	    && (v12buf.n > v12buf.base+1
811		|| v12buf.base->n_family != RIP_AF_AUTH))
812		supply_write(&v12buf);
813	if (v2buf.n != v2buf.base
814	    && (v2buf.n > v2buf.base+1
815		|| v2buf.base->n_family != RIP_AF_AUTH))
816		supply_write(&v2buf);
817
818	/* If we sent nothing and this is an answer to a query, send
819	 * an empty buffer.
820	 */
821	if (ws.npackets == 0
822	    && (ws.state & WS_ST_QUERY))
823		supply_write(&v12buf);
824}
825
826
827/* send all of the routing table or just do a flash update
828 */
829void
830rip_bcast(int flash)
831{
832#ifdef _HAVE_SIN_LEN
833	static struct sockaddr_in dst = {sizeof(dst), AF_INET, 0, {0}, {0}};
834#else
835	static struct sockaddr_in dst = {AF_INET};
836#endif
837	struct interface *ifp;
838	enum output_type type;
839	int vers;
840	struct timeval rtime;
841
842
843	need_flash = 0;
844	intvl_random(&rtime, MIN_WAITTIME, MAX_WAITTIME);
845	no_flash = rtime;
846	timevaladd(&no_flash, &now);
847
848	if (rip_sock < 0)
849		return;
850
851	trace_act("send %s and inhibit dynamic updates for %.3f sec",
852		  flash ? "dynamic update" : "all routes",
853		  rtime.tv_sec + ((float)rtime.tv_usec)/1000000.0);
854
855	for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
856		/* Skip interfaces not doing RIP.
857		 * Do try broken interfaces to see if they have healed.
858		 */
859		if (IS_RIP_OUT_OFF(ifp->int_state))
860			continue;
861
862		/* skip turned off interfaces */
863		if (!iff_up(ifp->int_if_flags))
864			continue;
865
866		vers = (ifp->int_state & IS_NO_RIPV1_OUT) ? RIPv2 : RIPv1;
867
868		if (ifp->int_if_flags & IFF_BROADCAST) {
869			/* ordinary, hardware interface */
870			dst.sin_addr.s_addr = ifp->int_brdaddr;
871
872			if (vers == RIPv2
873			    && !(ifp->int_state & IS_NO_RIP_MCAST)) {
874				type = OUT_MULTICAST;
875			} else {
876				type = OUT_BROADCAST;
877			}
878
879		} else if (ifp->int_if_flags & IFF_POINTOPOINT) {
880			/* point-to-point hardware interface */
881			dst.sin_addr.s_addr = ifp->int_dstaddr;
882			/* use multicast if the interface allows (e.g. GRE) */
883			if (vers == RIPv2
884			    && (ifp->int_if_flags & IFF_MULTICAST)
885			    && !(ifp->int_state & IS_NO_RIP_MCAST)) {
886				type = OUT_MULTICAST;
887			} else {
888				type = OUT_UNICAST;
889			}
890
891		} else if (ifp->int_state & IS_REMOTE) {
892			/* remote interface */
893			dst.sin_addr.s_addr = ifp->int_addr;
894			type = OUT_UNICAST;
895
896		} else {
897			/* ATM, HIPPI, etc. */
898			continue;
899		}
900
901		supply(&dst, ifp, type, flash, vers, 1);
902	}
903
904	update_seqno++;			/* all routes are up to date */
905}
906
907
908/* Ask for routes
909 * Do it only once to an interface, and not even after the interface
910 * was broken and recovered.
911 */
912void
913rip_query(void)
914{
915#ifdef _HAVE_SIN_LEN
916	static struct sockaddr_in dst = {sizeof(dst), AF_INET, 0, {0}, {0}};
917#else
918	static struct sockaddr_in dst = {AF_INET};
919#endif
920	struct interface *ifp;
921	struct rip buf;
922	enum output_type type;
923
924
925	if (rip_sock < 0)
926		return;
927
928	memset(&buf, 0, sizeof(buf));
929
930	for (ifp = ifnet; ifp; ifp = ifp->int_next) {
931		/* Skip interfaces those already queried.
932		 * Do not ask via interfaces through which we don't
933		 * accept input.  Do not ask via interfaces that cannot
934		 * send RIP packets.
935		 * Do try broken interfaces to see if they have healed.
936		 */
937		if (IS_RIP_IN_OFF(ifp->int_state)
938		    || ifp->int_query_time != NEVER)
939			continue;
940
941		/* skip turned off interfaces */
942		if (!iff_up(ifp->int_if_flags))
943			continue;
944
945		buf.rip_vers = (ifp->int_state&IS_NO_RIPV1_OUT) ? RIPv2:RIPv1;
946		buf.rip_cmd = RIPCMD_REQUEST;
947		buf.rip_nets[0].n_family = RIP_AF_UNSPEC;
948		buf.rip_nets[0].n_metric = htonl(HOPCNT_INFINITY);
949
950		/* Send a RIPv1 query only if allowed and if we will
951		 * listen to RIPv1 routers.
952		 */
953		if ((ifp->int_state & IS_NO_RIPV1_OUT)
954		    || (ifp->int_state & IS_NO_RIPV1_IN)) {
955			buf.rip_vers = RIPv2;
956		} else {
957			buf.rip_vers = RIPv1;
958		}
959
960		if (ifp->int_if_flags & IFF_BROADCAST) {
961			/* ordinary, hardware interface */
962			dst.sin_addr.s_addr = ifp->int_brdaddr;
963
964			/* Broadcast RIPv1 queries and RIPv2 queries
965			 * when the hardware cannot multicast.
966			 */
967			if (buf.rip_vers == RIPv2
968			    && (ifp->int_if_flags & IFF_MULTICAST)
969			    && !(ifp->int_state & IS_NO_RIP_MCAST)) {
970				type = OUT_MULTICAST;
971			} else {
972				type = OUT_BROADCAST;
973			}
974
975		} else if (ifp->int_if_flags & IFF_POINTOPOINT) {
976			/* point-to-point hardware interface */
977			dst.sin_addr.s_addr = ifp->int_dstaddr;
978			/* use multicast if the interface allows (e.g. GRE) */
979			if (buf.rip_vers == RIPv2
980			    && (ifp->int_if_flags & IFF_MULTICAST)
981			    && !(ifp->int_state & IS_NO_RIP_MCAST)) {
982				type = OUT_MULTICAST;
983			} else {
984				type = OUT_UNICAST;
985			}
986
987		} else if (ifp->int_state & IS_REMOTE) {
988			/* remote interface */
989			dst.sin_addr.s_addr = ifp->int_addr;
990			type = OUT_UNICAST;
991
992		} else {
993			/* ATM, HIPPI, etc. */
994			continue;
995		}
996
997		ifp->int_query_time = now.tv_sec+SUPPLY_INTERVAL;
998		if (output(type, &dst, ifp, &buf, sizeof(buf)) < 0)
999			if_sick(ifp);
1000	}
1001}
1002