xref: /dragonfly/sys/net/route.c (revision 383684a1)
1 /*
2  * Copyright (c) 2004, 2005 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Jeffrey M. Hsu.
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. Neither the name of The DragonFly Project nor the names of its
16  *    contributors may be used to endorse or promote products derived
17  *    from this software without specific, prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
22  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
23  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
24  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
25  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
26  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
27  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
28  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
29  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*
34  * Copyright (c) 2004, 2005 Jeffrey M. Hsu.  All rights reserved.
35  *
36  * License terms: all terms for the DragonFly license above plus the following:
37  *
38  * 4. All advertising materials mentioning features or use of this software
39  *    must display the following acknowledgement:
40  *
41  *	This product includes software developed by Jeffrey M. Hsu
42  *	for the DragonFly Project.
43  *
44  *    This requirement may be waived with permission from Jeffrey Hsu.
45  *    Permission will be granted to any DragonFly user for free.
46  *    This requirement will sunset and may be removed on Jan 31, 2006,
47  *    after which the standard DragonFly license (as shown above) will
48  *    apply.
49  */
50 
51 /*
52  * Copyright (c) 1980, 1986, 1991, 1993
53  *	The Regents of the University of California.  All rights reserved.
54  *
55  * Redistribution and use in source and binary forms, with or without
56  * modification, are permitted provided that the following conditions
57  * are met:
58  * 1. Redistributions of source code must retain the above copyright
59  *    notice, this list of conditions and the following disclaimer.
60  * 2. Redistributions in binary form must reproduce the above copyright
61  *    notice, this list of conditions and the following disclaimer in the
62  *    documentation and/or other materials provided with the distribution.
63  * 3. All advertising materials mentioning features or use of this software
64  *    must display the following acknowledgement:
65  *	This product includes software developed by the University of
66  *	California, Berkeley and its contributors.
67  * 4. Neither the name of the University nor the names of its contributors
68  *    may be used to endorse or promote products derived from this software
69  *    without specific prior written permission.
70  *
71  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
72  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
73  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
74  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
75  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
76  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
77  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
78  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
79  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
80  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
81  * SUCH DAMAGE.
82  *
83  *	@(#)route.c	8.3 (Berkeley) 1/9/95
84  * $FreeBSD: src/sys/net/route.c,v 1.59.2.10 2003/01/17 08:04:00 ru Exp $
85  * $DragonFly: src/sys/net/route.c,v 1.13 2005/01/06 17:59:32 hsu Exp $
86  */
87 
88 #include "opt_inet.h"
89 
90 #include <sys/param.h>
91 #include <sys/systm.h>
92 #include <sys/malloc.h>
93 #include <sys/mbuf.h>
94 #include <sys/socket.h>
95 #include <sys/domain.h>
96 #include <sys/kernel.h>
97 
98 #include <net/if.h>
99 #include <net/route.h>
100 
101 #include <netinet/in.h>
102 #include <net/ip_mroute/ip_mroute.h>
103 
104 static struct rtstat rtstat;
105 struct radix_node_head *rt_tables[AF_MAX+1];
106 
107 static void	rt_maskedcopy (struct sockaddr *, struct sockaddr *,
108 			       struct sockaddr *);
109 static void	rtable_init (void **);
110 
111 static void
112 rtable_init(void **table)
113 {
114 	struct domain *dom;
115 
116 	for (dom = domains; dom; dom = dom->dom_next)
117 		if (dom->dom_rtattach)
118 			dom->dom_rtattach(&table[dom->dom_family],
119 					  dom->dom_rtoffset);
120 }
121 
122 void
123 route_init()
124 {
125 	rn_init();	/* initialize all zeroes, all ones, mask table */
126 	rtable_init((void **)rt_tables);
127 }
128 
129 /*
130  * Packet routing routines.
131  */
132 
133 /*
134  * Look up and fill in the "ro_rt" rtentry field in a route structure given
135  * an address in the "ro_dst" field.  Always send a report on a miss and
136  * always clone routes.
137  */
138 void
139 rtalloc(struct route *ro)
140 {
141 	rtalloc_ign(ro, 0UL);
142 }
143 
144 /*
145  * Look up and fill in the "ro_rt" rtentry field in a route structure given
146  * an address in the "ro_dst" field.  Always send a report on a miss and
147  * optionally clone routes when RTF_CLONING or RTF_PRCLONING are not being
148  * ignored.
149  */
150 void
151 rtalloc_ign(struct route *ro, u_long ignoreflags)
152 {
153 	if (ro->ro_rt != NULL) {
154 		if (ro->ro_rt->rt_ifp != NULL && ro->ro_rt->rt_flags & RTF_UP)
155 			return;
156 		rtfree(ro->ro_rt);
157 		ro->ro_rt = NULL;
158 	}
159 	ro->ro_rt = _rtlookup(&ro->ro_dst, RTL_REPORTMSG, ignoreflags);
160 }
161 
162 /*
163  * Look up the route that matches the given "dst" address.
164  *
165  * Route lookup can have the side-effect of creating and returning
166  * a cloned route instead if "dst" matches a cloning route and the
167  * RTF_CLONING and RTF_PRCLONING flags are not being ignored.
168  *
169  * Any route returned has its reference count incremented.
170  */
171 struct rtentry *
172 _rtlookup(struct sockaddr *dst, boolean_t report, u_long ignore)
173 {
174 	struct radix_node_head *rnh = rt_tables[dst->sa_family];
175 	struct radix_node *rn;
176 	struct rtentry *rt;
177 
178 	if (rnh == NULL)
179 		goto unreach;
180 
181 	/*
182 	 * Look up route in the radix tree.
183 	 */
184 	rn = rnh->rnh_matchaddr((char *)dst, rnh);
185 	if (rn == NULL)
186 		goto unreach;
187 	else
188 		rt = (struct rtentry *)rn;
189 
190 	/*
191 	 * Handle cloning routes.
192 	 */
193 	if ((rt->rt_flags & ~ignore & (RTF_CLONING | RTF_PRCLONING)) != 0) {
194 		struct rtentry *clonedroute;
195 		int error;
196 
197 		clonedroute = rt;	/* copy in/copy out parameter */
198 		error = rtrequest(RTM_RESOLVE, dst, NULL, NULL, 0,
199 				  &clonedroute);	/* clone the route */
200 		if (error != 0) {	/* cloning failed */
201 			if (report)
202 				rt_dstmsg(RTM_MISS, dst, error);
203 			rt->rt_refcnt++;
204 			return (rt);	/* return the uncloned route */
205 		}
206 		if (report) {
207 			if (clonedroute->rt_flags & RTF_XRESOLVE)
208 				rt_dstmsg(RTM_RESOLVE, dst, 0);
209 			else
210 				rt_rtmsg(RTM_ADD, clonedroute,
211 					 clonedroute->rt_ifp, 0);
212 		}
213 		return (clonedroute);	/* return cloned route */
214 	}
215 
216 	/*
217 	 * Increment the reference count of the matched route and return.
218 	 */
219 	rt->rt_refcnt++;
220 	return (rt);
221 
222 unreach:
223 	rtstat.rts_unreach++;
224 	if (report)
225 		rt_dstmsg(RTM_MISS, dst, 0);
226 	return (NULL);
227 }
228 
229 void
230 rtfree(struct rtentry *rt)
231 {
232 	struct radix_node_head *rnh = rt_tables[rt_key(rt)->sa_family];
233 
234 	--rt->rt_refcnt;
235 	if (rnh->rnh_close && rt->rt_refcnt == 0)
236 		rnh->rnh_close((struct radix_node *)rt, rnh);
237 	if (rt->rt_refcnt <= 0 && !(rt->rt_flags & RTF_UP)) {
238 		KASSERT(!(rt->rt_nodes->rn_flags & (RNF_ACTIVE | RNF_ROOT)),
239 			("rtfree: rn_flags 0x%x ", rt->rt_nodes->rn_flags));
240 		KASSERT(rt->rt_refcnt == 0,
241 			("rtfree: rt_refcnt %ld", rt->rt_refcnt));
242 		if (rt->rt_ifa != NULL)
243 			IFAFREE(rt->rt_ifa);
244 		if (rt->rt_parent != NULL)
245 			RTFREE(rt->rt_parent);
246 		Free(rt_key(rt));  /* Also frees gateway.  See rt_setgate(). */
247 		Free(rt);
248 	}
249 }
250 
251 /*
252  * Force a routing table entry to the specified
253  * destination to go through the given gateway.
254  * Normally called as a result of a routing redirect
255  * message from the network layer.
256  *
257  * N.B.: must be called at splnet
258  */
259 void
260 rtredirect(
261 	struct sockaddr *dst,
262 	struct sockaddr *gateway,
263 	struct sockaddr *netmask,
264 	int flags,
265 	struct sockaddr *src,
266 	struct rtentry **rtp)
267 {
268 	struct rtentry *rt;
269 	struct rt_addrinfo info;
270 	struct ifaddr *ifa;
271 	short *stat = NULL;
272 	int error;
273 
274 	/* verify the gateway is directly reachable */
275 	if ((ifa = ifa_ifwithnet(gateway)) == NULL) {
276 		error = ENETUNREACH;
277 		goto out;
278 	}
279 
280 	/*
281 	 * If the redirect isn't from our current router for this dst,
282 	 * it's either old or wrong.  If it redirects us to ourselves,
283 	 * we have a routing loop, perhaps as a result of an interface
284 	 * going down recently.
285 	 */
286 	if (!(flags & RTF_DONE) &&
287 	    (rt = rtpurelookup(dst)) != NULL &&
288 	    (!sa_equal(src, rt->rt_gateway) || rt->rt_ifa != ifa)) {
289 		error = EINVAL;
290 		goto done;
291 	} else if (ifa_ifwithaddr(gateway)) {
292 		error = EHOSTUNREACH;
293 		goto done;
294 	}
295 
296 	/*
297 	 * Create a new entry if we just got back a wildcard entry
298 	 * or the the lookup failed.  This is necessary for hosts
299 	 * which use routing redirects generated by smart gateways
300 	 * to dynamically build the routing tables.
301 	 */
302 	if (rt == NULL || (rt_mask(rt) != NULL && rt_mask(rt)->sa_len < 2))
303 		goto create;
304 
305 	/*
306 	 * Don't listen to the redirect if it's for a route to an interface.
307 	 */
308 	if (rt->rt_flags & RTF_GATEWAY) {
309 		if ((!(rt->rt_flags & RTF_HOST)) && (flags & RTF_HOST)) {
310 			/*
311 			 * Changing from route to net => route to host.
312 			 * Create new route, rather than smashing route to net.
313 			 */
314 create:
315 			if (rt != NULL)
316 				rtfree(rt);
317 			flags |=  RTF_GATEWAY | RTF_DYNAMIC;
318 			bzero(&info, sizeof info);
319 			info.rti_info[RTAX_DST] = dst;
320 			info.rti_info[RTAX_GATEWAY] = gateway;
321 			info.rti_info[RTAX_NETMASK] = netmask;
322 			info.rti_ifa = ifa;
323 			info.rti_flags = flags;
324 			rt = NULL;
325 			error = rtrequest1(RTM_ADD, &info, &rt);
326 			if (rt != NULL)
327 				flags = rt->rt_flags;
328 			stat = &rtstat.rts_dynamic;
329 		} else {
330 			/*
331 			 * Smash the current notion of the gateway to
332 			 * this destination.  Should check about netmask!!!
333 			 */
334 			rt->rt_flags |= RTF_MODIFIED;
335 			flags |= RTF_MODIFIED;
336 			stat = &rtstat.rts_newgateway;
337 			/* Add the key and gateway (in one malloc'ed chunk). */
338 			rt_setgate(rt, rt_key(rt), gateway);
339 			error = 0;
340 		}
341 	} else {
342 		error = EHOSTUNREACH;
343 	}
344 
345 done:
346 	if (rt != NULL) {
347 		if (rtp != NULL && error == 0)
348 			*rtp = rt;
349 		else
350 			rtfree(rt);
351 	}
352 
353 out:
354 	if (error != 0)
355 		rtstat.rts_badredirect++;
356 	else if (stat != NULL)
357 		(*stat)++;
358 
359 	bzero(&info, sizeof info);
360 	info.rti_info[RTAX_DST] = dst;
361 	info.rti_info[RTAX_GATEWAY] = gateway;
362 	info.rti_info[RTAX_NETMASK] = netmask;
363 	info.rti_info[RTAX_AUTHOR] = src;
364 	rt_missmsg(RTM_REDIRECT, &info, flags, error);
365 }
366 
367 /*
368 * Routing table ioctl interface.
369 */
370 int
371 rtioctl(u_long req, caddr_t data, struct thread *td)
372 {
373 #ifdef INET
374 	/* Multicast goop, grrr... */
375 	return mrt_ioctl ? mrt_ioctl(req, data) : EOPNOTSUPP;
376 #else
377 	return ENXIO;
378 #endif
379 }
380 
381 struct ifaddr *
382 ifa_ifwithroute(int flags, struct sockaddr *dst, struct sockaddr *gateway)
383 {
384 	struct ifaddr *ifa;
385 
386 	if (!(flags & RTF_GATEWAY)) {
387 		/*
388 		 * If we are adding a route to an interface,
389 		 * and the interface is a point-to-point link,
390 		 * we should search for the destination
391 		 * as our clue to the interface.  Otherwise
392 		 * we can use the local address.
393 		 */
394 		ifa = NULL;
395 		if (flags & RTF_HOST) {
396 			ifa = ifa_ifwithdstaddr(dst);
397 		}
398 		if (ifa == NULL)
399 			ifa = ifa_ifwithaddr(gateway);
400 	} else {
401 		/*
402 		 * If we are adding a route to a remote net
403 		 * or host, the gateway may still be on the
404 		 * other end of a pt to pt link.
405 		 */
406 		ifa = ifa_ifwithdstaddr(gateway);
407 	}
408 	if (ifa == NULL)
409 		ifa = ifa_ifwithnet(gateway);
410 	if (ifa == NULL) {
411 		struct rtentry *rt = rtpurelookup(gateway);
412 
413 		if (rt == NULL)
414 			return (NULL);
415 		rt->rt_refcnt--;
416 		if ((ifa = rt->rt_ifa) == NULL)
417 			return (NULL);
418 	}
419 	if (ifa->ifa_addr->sa_family != dst->sa_family) {
420 		struct ifaddr *oifa = ifa;
421 
422 		ifa = ifaof_ifpforaddr(dst, ifa->ifa_ifp);
423 		if (ifa == NULL)
424 			ifa = oifa;
425 	}
426 	return (ifa);
427 }
428 
429 static int rt_fixdelete (struct radix_node *, void *);
430 static int rt_fixchange (struct radix_node *, void *);
431 
432 struct rtfc_arg {
433 	struct rtentry *rt0;
434 	struct radix_node_head *rnh;
435 };
436 
437 int
438 rt_getifa(struct rt_addrinfo *info)
439 {
440 	struct sockaddr *gateway = info->rti_info[RTAX_GATEWAY];
441 	struct sockaddr *dst = info->rti_info[RTAX_DST];
442 	struct sockaddr *ifaaddr = info->rti_info[RTAX_IFA];
443 	struct sockaddr *ifpaddr = info->rti_info[RTAX_IFP];
444 	int flags = info->rti_flags;
445 	struct ifaddr *ifa;
446 	int error = 0;
447 
448 	/*
449 	 * ifp may be specified by sockaddr_dl
450 	 * when protocol address is ambiguous.
451 	 */
452 	if (info->rti_ifp == NULL && ifpaddr != NULL &&
453 	    ifpaddr->sa_family == AF_LINK &&
454 	    (ifa = ifa_ifwithnet(ifpaddr)) != NULL)
455 		info->rti_ifp = ifa->ifa_ifp;
456 	if (info->rti_ifa == NULL && ifaaddr != NULL)
457 		info->rti_ifa = ifa_ifwithaddr(ifaaddr);
458 	if (info->rti_ifa == NULL) {
459 		struct sockaddr *sa;
460 
461 		sa = ifaaddr != NULL ? ifaaddr :
462 		    (gateway != NULL ? gateway : dst);
463 		if (sa != NULL && info->rti_ifp != NULL)
464 			info->rti_ifa = ifaof_ifpforaddr(sa, info->rti_ifp);
465 		else if (dst != NULL && gateway != NULL)
466 			info->rti_ifa = ifa_ifwithroute(flags, dst, gateway);
467 		else if (sa != NULL)
468 			info->rti_ifa = ifa_ifwithroute(flags, sa, sa);
469 	}
470 	if ((ifa = info->rti_ifa) != NULL) {
471 		if (info->rti_ifp == NULL)
472 			info->rti_ifp = ifa->ifa_ifp;
473 	} else
474 		error = ENETUNREACH;
475 	return (error);
476 }
477 
478 /*
479  * Do appropriate manipulations of a routing tree given
480  * all the bits of info needed
481  */
482 int
483 rtrequest(
484 	int req,
485 	struct sockaddr *dst,
486 	struct sockaddr *gateway,
487 	struct sockaddr *netmask,
488 	int flags,
489 	struct rtentry **ret_nrt)
490 {
491 	struct rt_addrinfo info;
492 
493 	bzero(&info, sizeof info);
494 	info.rti_flags = flags;
495 	info.rti_info[RTAX_DST] = dst;
496 	info.rti_info[RTAX_GATEWAY] = gateway;
497 	info.rti_info[RTAX_NETMASK] = netmask;
498 	return rtrequest1(req, &info, ret_nrt);
499 }
500 
501 int
502 rtrequest1(int req, struct rt_addrinfo *info, struct rtentry **ret_nrt)
503 {
504 	struct sockaddr *dst = info->rti_info[RTAX_DST];
505 	struct rtentry *rt;
506 	struct radix_node *rn;
507 	struct radix_node_head *rnh;
508 	struct ifaddr *ifa;
509 	struct sockaddr *ndst;
510 	int error = 0;
511 	int s;
512 
513 #define gotoerr(x) { error = x ; goto bad; }
514 
515 	s = splnet();
516 	/*
517 	 * Find the correct routing tree to use for this Address Family
518 	 */
519 	if ((rnh = rt_tables[dst->sa_family]) == NULL)
520 		gotoerr(EAFNOSUPPORT);
521 
522 	/*
523 	 * If we are adding a host route then we don't want to put
524 	 * a netmask in the tree, nor do we want to clone it.
525 	 */
526 	if (info->rti_flags & RTF_HOST) {
527 		info->rti_info[RTAX_NETMASK] = NULL;
528 		info->rti_flags &= ~(RTF_CLONING | RTF_PRCLONING);
529 	}
530 
531 	switch (req) {
532 	case RTM_DELETE:
533 		/* Remove the item from the tree. */
534 		rn = rnh->rnh_deladdr((char *)info->rti_info[RTAX_DST],
535 				      (char *)info->rti_info[RTAX_NETMASK],
536 				      rnh);
537 		if (rn == NULL)
538 			gotoerr(ESRCH);
539 		KASSERT(!(rn->rn_flags & (RNF_ACTIVE | RNF_ROOT)),
540 			("rnh_deladdr returned flags 0x%x", rn->rn_flags));
541 		rt = (struct rtentry *)rn;
542 
543 		/* Free any routes cloned from this one. */
544 		if ((rt->rt_flags & (RTF_CLONING | RTF_PRCLONING)) &&
545 		    rt_mask(rt) != NULL) {
546 			rnh->rnh_walktree_from(rnh, (char *)rt_key(rt),
547 					       (char *)rt_mask(rt),
548 					       rt_fixdelete, rt);
549 		}
550 
551 		if (rt->rt_gwroute != NULL) {
552 			RTFREE(rt->rt_gwroute);
553 			rt->rt_gwroute = NULL;
554 		}
555 
556 		/*
557 		 * NB: RTF_UP must be set during the search above,
558 		 * because we might delete the last ref, causing
559 		 * rt to get freed prematurely.
560 		 */
561 		rt->rt_flags &= ~RTF_UP;
562 
563 		/* Give the protocol a chance to keep things in sync. */
564 		if ((ifa = rt->rt_ifa) && ifa->ifa_rtrequest)
565 			ifa->ifa_rtrequest(RTM_DELETE, rt, info);
566 
567 		/*
568 		 * If the caller wants it, then it can have it,
569 		 * but it's up to it to free the rtentry as we won't be
570 		 * doing it.
571 		 */
572 		if (ret_nrt != NULL) {
573 			*ret_nrt = rt;
574 		} else if (rt->rt_refcnt <= 0) {
575 			rt->rt_refcnt++;  /* refcnt > 0 required for rtfree() */
576 			rtfree(rt);
577 		}
578 		break;
579 
580 	case RTM_RESOLVE:
581 		if (ret_nrt == NULL || (rt = *ret_nrt) == NULL)
582 			gotoerr(EINVAL);
583 		ifa = rt->rt_ifa;
584 		info->rti_flags = rt->rt_flags &
585 		    ~(RTF_CLONING | RTF_PRCLONING | RTF_STATIC);
586 		info->rti_flags |= RTF_WASCLONED;
587 		info->rti_info[RTAX_GATEWAY] = rt->rt_gateway;
588 		if ((info->rti_info[RTAX_NETMASK] = rt->rt_genmask) == NULL)
589 			info->rti_flags |= RTF_HOST;
590 		goto makeroute;
591 
592 	case RTM_ADD:
593 		KASSERT(!(info->rti_flags & RTF_GATEWAY) ||
594 			info->rti_info[RTAX_GATEWAY] != NULL,
595 		    ("rtrequest: GATEWAY but no gateway"));
596 
597 		if (info->rti_ifa == NULL && (error = rt_getifa(info)))
598 			gotoerr(error);
599 		ifa = info->rti_ifa;
600 makeroute:
601 		R_Malloc(rt, struct rtentry *, sizeof *rt);
602 		if (rt == NULL)
603 			gotoerr(ENOBUFS);
604 		bzero(rt, sizeof *rt);
605 		rt->rt_flags = RTF_UP | info->rti_flags;
606 		error = rt_setgate(rt, dst, info->rti_info[RTAX_GATEWAY]);
607 		if (error != 0) {
608 			Free(rt);
609 			gotoerr(error);
610 		}
611 
612 		ndst = rt_key(rt);
613 		if (info->rti_info[RTAX_NETMASK] != NULL)
614 			rt_maskedcopy(dst, ndst, info->rti_info[RTAX_NETMASK]);
615 		else
616 			bcopy(dst, ndst, dst->sa_len);
617 
618 		/*
619 		 * Note that we now have a reference to the ifa.
620 		 * This moved from below so that rnh->rnh_addaddr() can
621 		 * examine the ifa and  ifa->ifa_ifp if it so desires.
622 		 */
623 		IFAREF(ifa);
624 		rt->rt_ifa = ifa;
625 		rt->rt_ifp = ifa->ifa_ifp;
626 		/* XXX mtu manipulation will be done in rnh_addaddr -- itojun */
627 
628 		rn = rnh->rnh_addaddr((char *)ndst,
629 				      (char *)info->rti_info[RTAX_NETMASK],
630 				      rnh, rt->rt_nodes);
631 		if (rn == NULL) {
632 			struct rtentry *oldrt;
633 
634 			/*
635 			 * We already have one of these in the tree.
636 			 * We do a special hack: if the old route was
637 			 * cloned, then we blow it away and try
638 			 * re-inserting the new one.
639 			 */
640 			oldrt = rtpurelookup(ndst);
641 			if (oldrt != NULL) {
642 				--oldrt->rt_refcnt;
643 				if (oldrt->rt_flags & RTF_WASCLONED) {
644 					rtrequest(RTM_DELETE, rt_key(oldrt),
645 						  oldrt->rt_gateway,
646 						  rt_mask(oldrt),
647 						  oldrt->rt_flags, NULL);
648 					rn = rnh->rnh_addaddr((char *)ndst,
649 						  (char *)
650 						  info->rti_info[RTAX_NETMASK],
651 						  rnh, rt->rt_nodes);
652 				}
653 			}
654 		}
655 
656 		/*
657 		 * If it still failed to go into the tree,
658 		 * then un-make it (this should be a function).
659 		 */
660 		if (rn == NULL) {
661 			if (rt->rt_gwroute != NULL)
662 				rtfree(rt->rt_gwroute);
663 			IFAFREE(ifa);
664 			Free(rt_key(rt));
665 			Free(rt);
666 			gotoerr(EEXIST);
667 		}
668 
669 		/*
670 		 * If we got here from RESOLVE, then we are cloning
671 		 * so clone the rest, and note that we
672 		 * are a clone (and increment the parent's references)
673 		 */
674 		if (req == RTM_RESOLVE) {
675 			rt->rt_rmx = (*ret_nrt)->rt_rmx;    /* copy metrics */
676 			rt->rt_rmx.rmx_pksent = 0;  /* reset packet counter */
677 			if ((*ret_nrt)->rt_flags &
678 				       (RTF_CLONING | RTF_PRCLONING)) {
679 				rt->rt_parent = *ret_nrt;
680 				(*ret_nrt)->rt_refcnt++;
681 			}
682 		}
683 
684 		/*
685 		 * if this protocol has something to add to this then
686 		 * allow it to do that as well.
687 		 */
688 		if (ifa->ifa_rtrequest != NULL)
689 			ifa->ifa_rtrequest(req, rt, info);
690 
691 		/*
692 		 * We repeat the same procedure from rt_setgate() here because
693 		 * it doesn't fire when we call it there because the node
694 		 * hasn't been added to the tree yet.
695 		 */
696 		if (req == RTM_ADD && !(rt->rt_flags & RTF_HOST) &&
697 		    rt_mask(rt) != NULL) {
698 			struct rtfc_arg arg = { rt, rnh };
699 
700 			rnh->rnh_walktree_from(rnh, (char *)rt_key(rt),
701 					       (char *)rt_mask(rt),
702 					       rt_fixchange, &arg);
703 		}
704 
705 		/*
706 		 * Return the resulting rtentry,
707 		 * increasing the number of references by one.
708 		 */
709 		if (ret_nrt != NULL) {
710 			rt->rt_refcnt++;
711 			*ret_nrt = rt;
712 		}
713 		break;
714 	default:
715 		error = EOPNOTSUPP;
716 	}
717 bad:
718 	splx(s);
719 	return (error);
720 }
721 
722 /*
723  * Called from rtrequest(RTM_DELETE, ...) to fix up the route's ``family''
724  * (i.e., the routes related to it by the operation of cloning).  This
725  * routine is iterated over all potential former-child-routes by way of
726  * rnh->rnh_walktree_from() above, and those that actually are children of
727  * the late parent (passed in as VP here) are themselves deleted.
728  */
729 static int
730 rt_fixdelete(struct radix_node *rn, void *vp)
731 {
732 	struct rtentry *rt = (struct rtentry *)rn;
733 	struct rtentry *rt0 = vp;
734 
735 	if (rt->rt_parent == rt0 &&
736 	    !(rt->rt_flags & (RTF_PINNED | RTF_CLONING | RTF_PRCLONING))) {
737 		return rtrequest(RTM_DELETE, rt_key(rt), NULL, rt_mask(rt),
738 				 rt->rt_flags, NULL);
739 	}
740 	return 0;
741 }
742 
743 /*
744  * This routine is called from rt_setgate() to do the analogous thing for
745  * adds and changes.  There is the added complication in this case of a
746  * middle insert; i.e., insertion of a new network route between an older
747  * network route and (cloned) host routes.  For this reason, a simple check
748  * of rt->rt_parent is insufficient; each candidate route must be tested
749  * against the (mask, value) of the new route (passed as before in vp)
750  * to see if the new route matches it.
751  *
752  * XXX - it may be possible to do fixdelete() for changes and reserve this
753  * routine just for adds.  I'm not sure why I thought it was necessary to do
754  * changes this way.
755  */
756 #ifdef DEBUG
757 static int rtfcdebug = 0;
758 #endif
759 
760 static int
761 rt_fixchange(struct radix_node *rn, void *vp)
762 {
763 	struct rtentry *rt = (struct rtentry *)rn;
764 	struct rtfc_arg *ap = vp;
765 	struct rtentry *rt0 = ap->rt0;
766 	struct radix_node_head *rnh = ap->rnh;
767 	u_char *xk1, *xm1, *xk2, *xmp;
768 	int i, len, mlen;
769 
770 #ifdef DEBUG
771 	if (rtfcdebug)
772 		printf("rt_fixchange: rt %p, rt0 %p\n", rt, rt0);
773 #endif
774 
775 	if (rt->rt_parent == NULL ||
776 	    (rt->rt_flags & (RTF_PINNED | RTF_CLONING | RTF_PRCLONING))) {
777 #ifdef DEBUG
778 		if (rtfcdebug) printf("no parent, pinned or cloning\n");
779 #endif
780 		return 0;
781 	}
782 
783 	if (rt->rt_parent == rt0) {
784 #ifdef DEBUG
785 		if (rtfcdebug) printf("parent match\n");
786 #endif
787 		return rtrequest(RTM_DELETE, rt_key(rt), NULL, rt_mask(rt),
788 				 rt->rt_flags, NULL);
789 	}
790 
791 	/*
792 	 * There probably is a function somewhere which does this...
793 	 * if not, there should be.
794 	 */
795 	len = imin(rt_key(rt0)->sa_len, rt_key(rt)->sa_len);
796 
797 	xk1 = (u_char *)rt_key(rt0);
798 	xm1 = (u_char *)rt_mask(rt0);
799 	xk2 = (u_char *)rt_key(rt);
800 
801 	/* avoid applying a less specific route */
802 	xmp = (u_char *)rt_mask(rt->rt_parent);
803 	mlen = rt_key(rt->rt_parent)->sa_len;
804 	if (mlen > rt_key(rt0)->sa_len) {
805 #ifdef DEBUG
806 		if (rtfcdebug)
807 			printf("rt_fixchange: inserting a less "
808 			       "specific route\n");
809 #endif
810 		return 0;
811 	}
812 	for (i = rnh->rnh_treetop->rn_offset; i < mlen; i++) {
813 		if ((xmp[i] & ~(xmp[i] ^ xm1[i])) != xmp[i]) {
814 #ifdef DEBUG
815 			if (rtfcdebug)
816 				printf("rt_fixchange: inserting a less "
817 				       "specific route\n");
818 #endif
819 			return 0;
820 		}
821 	}
822 
823 	for (i = rnh->rnh_treetop->rn_offset; i < len; i++) {
824 		if ((xk2[i] & xm1[i]) != xk1[i]) {
825 #ifdef DEBUG
826 			if (rtfcdebug) printf("no match\n");
827 #endif
828 			return 0;
829 		}
830 	}
831 
832 	/*
833 	 * OK, this node is a clone, and matches the node currently being
834 	 * changed/added under the node's mask.  So, get rid of it.
835 	 */
836 #ifdef DEBUG
837 	if (rtfcdebug) printf("deleting\n");
838 #endif
839 	return rtrequest(RTM_DELETE, rt_key(rt), NULL, rt_mask(rt),
840 			 rt->rt_flags, NULL);
841 }
842 
843 #define ROUNDUP(a) (a>0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
844 
845 int
846 rt_setgate(struct rtentry *rt0, struct sockaddr *dst, struct sockaddr *gate)
847 {
848 	char *space, *oldspace;
849 	int dlen = ROUNDUP(dst->sa_len), glen = ROUNDUP(gate->sa_len);
850 	struct rtentry *rt = rt0;
851 	struct radix_node_head *rnh = rt_tables[dst->sa_family];
852 
853 	/*
854 	 * A host route with the destination equal to the gateway
855 	 * will interfere with keeping LLINFO in the routing
856 	 * table, so disallow it.
857 	 */
858 	if (((rt0->rt_flags & (RTF_HOST | RTF_GATEWAY | RTF_LLINFO)) ==
859 			      (RTF_HOST | RTF_GATEWAY)) &&
860 	    dst->sa_len == gate->sa_len &&
861 	    sa_equal(dst, gate)) {
862 		/*
863 		 * The route might already exist if this is an RTM_CHANGE
864 		 * or a routing redirect, so try to delete it.
865 		 */
866 		if (rt_key(rt0) != NULL)
867 			rtrequest(RTM_DELETE, rt_key(rt0), rt0->rt_gateway,
868 				  rt_mask(rt0), rt0->rt_flags, NULL);
869 		return EADDRNOTAVAIL;
870 	}
871 
872 	/*
873 	 * Both dst and gateway are stored in the same malloc'ed chunk
874 	 * (If I ever get my hands on....)
875 	 * if we need to malloc a new chunk, then keep the old one around
876 	 * till we don't need it any more.
877 	 */
878 	if (rt->rt_gateway == NULL || glen > ROUNDUP(rt->rt_gateway->sa_len)) {
879 		oldspace = (char *)rt_key(rt);
880 		R_Malloc(space, char *, dlen + glen);
881 		if (space == NULL)
882 			return ENOBUFS;
883 		rt->rt_nodes->rn_key = space;
884 	} else {
885 		space = (char *)rt_key(rt);	/* Just use the old space. */
886 		oldspace = NULL;
887 	}
888 
889 	/* Set the gateway value. */
890 	rt->rt_gateway = (struct sockaddr *)(space + dlen);
891 	bcopy(gate, rt->rt_gateway, glen);
892 
893 	if (oldspace != NULL) {
894 		/*
895 		 * If we allocated a new chunk, preserve the original dst.
896 		 * This way, rt_setgate() really just sets the gate
897 		 * and leaves the dst field alone.
898 		 */
899 		bcopy(dst, space, dlen);
900 		Free(oldspace);
901 	}
902 
903 	/*
904 	 * If there is already a gwroute, it's now almost definitely wrong
905 	 * so drop it.
906 	 */
907 	if (rt->rt_gwroute != NULL) {
908 		RTFREE(rt->rt_gwroute);
909 		rt->rt_gwroute = NULL;
910 	}
911 	if (rt->rt_flags & RTF_GATEWAY) {
912 		/*
913 		 * Cloning loop avoidance: In the presence of
914 		 * protocol-cloning and bad configuration, it is
915 		 * possible to get stuck in bottomless mutual recursion
916 		 * (rtrequest rt_setgate rtlookup).  We avoid this
917 		 * by not allowing protocol-cloning to operate for
918 		 * gateways (which is probably the correct choice
919 		 * anyway), and avoid the resulting reference loops
920 		 * by disallowing any route to run through itself as
921 		 * a gateway.  This is obviously mandatory when we
922 		 * get rt->rt_output().
923 		 *
924 		 * This breaks TTCP for hosts outside the gateway!  XXX JH
925 		 */
926 		rt->rt_gwroute = _rtlookup(gate, RTL_REPORTMSG, RTF_PRCLONING);
927 		if (rt->rt_gwroute == rt) {
928 			rt->rt_gwroute = NULL;
929 			--rt->rt_refcnt;
930 			return EDQUOT; /* failure */
931 		}
932 	}
933 
934 	/*
935 	 * This isn't going to do anything useful for host routes, so
936 	 * don't bother.  Also make sure we have a reasonable mask
937 	 * (we don't yet have one during adds).
938 	 */
939 	if (!(rt->rt_flags & RTF_HOST) && rt_mask(rt) != NULL) {
940 		struct rtfc_arg arg = { rt, rnh };
941 
942 		rnh->rnh_walktree_from(rnh, (char *)rt_key(rt),
943 				       (char *)rt_mask(rt),
944 				       rt_fixchange, &arg);
945 	}
946 
947 	return 0;
948 }
949 
950 static void
951 rt_maskedcopy(
952 	struct sockaddr *src,
953 	struct sockaddr *dst,
954 	struct sockaddr *netmask)
955 {
956 	u_char *cp1 = (u_char *)src;
957 	u_char *cp2 = (u_char *)dst;
958 	u_char *cp3 = (u_char *)netmask;
959 	u_char *cplim = cp2 + *cp3;
960 	u_char *cplim2 = cp2 + *cp1;
961 
962 	*cp2++ = *cp1++; *cp2++ = *cp1++; /* copies sa_len & sa_family */
963 	cp3 += 2;
964 	if (cplim > cplim2)
965 		cplim = cplim2;
966 	while (cp2 < cplim)
967 		*cp2++ = *cp1++ & *cp3++;
968 	if (cp2 < cplim2)
969 		bzero(cp2, cplim2 - cp2);
970 }
971 
972 int
973 rt_llroute(struct sockaddr *dst, struct rtentry *rt0, struct rtentry **drt)
974 {
975 	struct rtentry *up_rt, *rt;
976 
977 	if (!(rt0->rt_flags & RTF_UP)) {
978 		up_rt = rtlookup(dst);
979 		if (up_rt == NULL)
980 			return (EHOSTUNREACH);
981 		up_rt->rt_refcnt--;
982 	} else
983 		up_rt = rt0;
984 	if (up_rt->rt_flags & RTF_GATEWAY) {
985 		if (up_rt->rt_gwroute == NULL) {
986 			up_rt->rt_gwroute = rtlookup(up_rt->rt_gateway);
987 			if (up_rt->rt_gwroute == NULL)
988 				return (EHOSTUNREACH);
989 		} else if (!(up_rt->rt_gwroute->rt_flags & RTF_UP)) {
990 			rtfree(up_rt->rt_gwroute);
991 			up_rt->rt_gwroute = rtlookup(up_rt->rt_gateway);
992 			if (up_rt->rt_gwroute == NULL)
993 				return (EHOSTUNREACH);
994 		}
995 		rt = up_rt->rt_gwroute;
996 	} else
997 		rt = up_rt;
998 	if (rt->rt_flags & RTF_REJECT &&
999 	    (rt->rt_rmx.rmx_expire == 0 ||		/* rt doesn't expire */
1000 	     time_second < rt->rt_rmx.rmx_expire))	/* rt not expired */
1001 		return (rt->rt_flags & RTF_HOST ?  EHOSTDOWN : EHOSTUNREACH);
1002 	*drt = rt;
1003 	return 0;
1004 }
1005 
1006 /*
1007  * Set up a routing table entry, normally
1008  * for an interface.
1009  */
1010 int
1011 rtinit(struct ifaddr *ifa, int cmd, int flags)
1012 {
1013 	struct sockaddr *dst, *deldst, *netmask;
1014 	struct rtentry *rt;
1015 	struct rtentry *nrt = NULL;
1016 	struct mbuf *m = NULL;
1017 	struct radix_node_head *rnh;
1018 	struct radix_node *rn;
1019 	struct rt_addrinfo info;
1020 	int error;
1021 
1022 	if (flags & RTF_HOST) {
1023 		dst = ifa->ifa_dstaddr;
1024 		netmask = NULL;
1025 	} else {
1026 		dst = ifa->ifa_addr;
1027 		netmask = ifa->ifa_netmask;
1028 	}
1029 	/*
1030 	 * If it's a delete, check that if it exists, it's on the correct
1031 	 * interface or we might scrub a route to another ifa which would
1032 	 * be confusing at best and possibly worse.
1033 	 */
1034 	if (cmd == RTM_DELETE) {
1035 		/*
1036 		 * It's a delete, so it should already exist..
1037 		 * If it's a net, mask off the host bits
1038 		 * (Assuming we have a mask)
1039 		 */
1040 		if (netmask != NULL) {
1041 			m = m_get(MB_DONTWAIT, MT_SONAME);
1042 			if (m == NULL)
1043 				return (ENOBUFS);
1044 			deldst = mtod(m, struct sockaddr *);
1045 			rt_maskedcopy(dst, deldst, netmask);
1046 			dst = deldst;
1047 		}
1048 		/*
1049 		 * Look up an rtentry that is in the routing tree and
1050 		 * contains the correct info.
1051 		 */
1052 		if ((rnh = rt_tables[dst->sa_family]) == NULL ||
1053 		    (rn = rnh->rnh_lookup((char *)dst,
1054 					  (char *)netmask, rnh)) == NULL ||
1055 		    ((struct rtentry *)rn)->rt_ifa != ifa ||
1056 		    !sa_equal((struct sockaddr *)rn->rn_key, dst)) {
1057 			if (m != NULL)
1058 				m_free(m);
1059 			return (flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
1060 		}
1061 		/* XXX */
1062 #if 0
1063 		else {
1064 			/*
1065 			 * One would think that as we are deleting, and we know
1066 			 * it doesn't exist, we could just return at this point
1067 			 * with an "ELSE" clause, but apparently not..
1068 			 */
1069 			return (flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
1070 		}
1071 #endif
1072 	}
1073 	/*
1074 	 * Do the actual request
1075 	 */
1076 	bzero(&info, sizeof info);
1077 	info.rti_ifa = ifa;
1078 	info.rti_flags = flags | ifa->ifa_flags;
1079 	info.rti_info[RTAX_DST] = dst;
1080 	info.rti_info[RTAX_GATEWAY] = ifa->ifa_addr;
1081 	info.rti_info[RTAX_NETMASK] = netmask;
1082 	error = rtrequest1(cmd, &info, &nrt);
1083 	if (error == 0 && (rt = nrt) != NULL) {
1084 		/*
1085 		 * notify any listening routing agents of the change
1086 		 */
1087 		rt_newaddrmsg(cmd, ifa, error, rt);
1088 		if (cmd == RTM_DELETE) {
1089 			/*
1090 			 * If we are deleting, and we found an entry, then
1091 			 * it's been removed from the tree.. now throw it away.
1092 			 */
1093 			if (rt->rt_refcnt <= 0) {
1094 				rt->rt_refcnt++; /* make a 1->0 transition */
1095 				rtfree(rt);
1096 			}
1097 		} else if (cmd == RTM_ADD) {
1098 			/*
1099 			 * We just wanted to add it.. we don't actually
1100 			 * need a reference.
1101 			 */
1102 			rt->rt_refcnt--;
1103 		}
1104 	}
1105 	if (m != NULL)
1106 		m_free(m);
1107 	return (error);
1108 }
1109 
1110 /* This must be before ip6_init2(), which is now SI_ORDER_MIDDLE */
1111 SYSINIT(route, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, route_init, 0);
1112