xref: /netbsd-src/sys/net/if.c (revision 5aefcfdc06931dd97e76246d2fe0302f7b3fe094)
1 /*	$NetBSD: if.c,v 1.80 2000/12/18 21:05:04 thorpej Exp $	*/
2 
3 /*-
4  * Copyright (c) 1999, 2000 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by William Studnemund and Jason R. Thorpe.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the NetBSD
21  *	Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
41  * All rights reserved.
42  *
43  * Redistribution and use in source and binary forms, with or without
44  * modification, are permitted provided that the following conditions
45  * are met:
46  * 1. Redistributions of source code must retain the above copyright
47  *    notice, this list of conditions and the following disclaimer.
48  * 2. Redistributions in binary form must reproduce the above copyright
49  *    notice, this list of conditions and the following disclaimer in the
50  *    documentation and/or other materials provided with the distribution.
51  * 3. Neither the name of the project nor the names of its contributors
52  *    may be used to endorse or promote products derived from this software
53  *    without specific prior written permission.
54  *
55  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
56  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
58  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
59  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
60  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
61  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
62  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
63  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
64  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
65  * SUCH DAMAGE.
66  */
67 
68 /*
69  * Copyright (c) 1980, 1986, 1993
70  *	The Regents of the University of California.  All rights reserved.
71  *
72  * Redistribution and use in source and binary forms, with or without
73  * modification, are permitted provided that the following conditions
74  * are met:
75  * 1. Redistributions of source code must retain the above copyright
76  *    notice, this list of conditions and the following disclaimer.
77  * 2. Redistributions in binary form must reproduce the above copyright
78  *    notice, this list of conditions and the following disclaimer in the
79  *    documentation and/or other materials provided with the distribution.
80  * 3. All advertising materials mentioning features or use of this software
81  *    must display the following acknowledgement:
82  *	This product includes software developed by the University of
83  *	California, Berkeley and its contributors.
84  * 4. Neither the name of the University nor the names of its contributors
85  *    may be used to endorse or promote products derived from this software
86  *    without specific prior written permission.
87  *
88  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
89  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
90  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
91  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
92  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
93  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
94  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
95  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
96  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
97  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
98  * SUCH DAMAGE.
99  *
100  *	@(#)if.c	8.5 (Berkeley) 1/9/95
101  */
102 
103 #include "opt_inet.h"
104 
105 #include "opt_compat_linux.h"
106 #include "opt_compat_svr4.h"
107 #include "opt_compat_43.h"
108 #include "opt_atalk.h"
109 
110 #include <sys/param.h>
111 #include <sys/mbuf.h>
112 #include <sys/systm.h>
113 #include <sys/callout.h>
114 #include <sys/proc.h>
115 #include <sys/socket.h>
116 #include <sys/socketvar.h>
117 #include <sys/domain.h>
118 #include <sys/protosw.h>
119 #include <sys/kernel.h>
120 #include <sys/ioctl.h>
121 
122 #include <net/if.h>
123 #include <net/if_dl.h>
124 #include <net/if_ether.h>
125 #include <net/if_ieee80211.h>
126 #include <net/if_types.h>
127 #include <net/radix.h>
128 #include <net/route.h>
129 #ifdef NETATALK
130 #include <netatalk/at_extern.h>
131 #include <netatalk/at.h>
132 #endif
133 
134 #ifdef INET6
135 /*XXX*/
136 #include <netinet/in.h>
137 #include <netinet6/in6_var.h>
138 #endif
139 
140 int	ifqmaxlen = IFQ_MAXLEN;
141 struct	callout if_slowtimo_ch;
142 
143 #ifdef INET6
144 /*
145  * XXX: declare here to avoid to include many inet6 related files..
146  * should be more generalized?
147  */
148 extern void nd6_setmtu __P((struct ifnet *));
149 #endif
150 
151 int	if_rt_walktree __P((struct radix_node *, void *));
152 
153 struct if_clone *if_clone_lookup __P((const char *, int *));
154 int if_clone_list __P((struct if_clonereq *));
155 
156 LIST_HEAD(, if_clone) if_cloners = LIST_HEAD_INITIALIZER(if_cloners);
157 int if_cloners_count;
158 
159 /*
160  * Network interface utility routines.
161  *
162  * Routines with ifa_ifwith* names take sockaddr *'s as
163  * parameters.
164  */
165 void
166 ifinit()
167 {
168 
169 	callout_init(&if_slowtimo_ch);
170 	if_slowtimo(NULL);
171 }
172 
173 /*
174  * Null routines used while an interface is going away.  These routines
175  * just return an error.
176  */
177 
178 int
179 if_nulloutput(ifp, m, so, rt)
180 	struct ifnet *ifp;
181 	struct mbuf *m;
182 	struct sockaddr *so;
183 	struct rtentry *rt;
184 {
185 
186 	return (ENXIO);
187 }
188 
189 void
190 if_nullinput(ifp, m)
191 	struct ifnet *ifp;
192 	struct mbuf *m;
193 {
194 
195 	/* Nothing. */
196 }
197 
198 void
199 if_nullstart(ifp)
200 	struct ifnet *ifp;
201 {
202 
203 	/* Nothing. */
204 }
205 
206 int
207 if_nullioctl(ifp, cmd, data)
208 	struct ifnet *ifp;
209 	u_long cmd;
210 	caddr_t data;
211 {
212 
213 	return (ENXIO);
214 }
215 
216 int
217 if_nullinit(ifp)
218 	struct ifnet *ifp;
219 {
220 
221 	return (ENXIO);
222 }
223 
224 void
225 if_nullstop(ifp, disable)
226 	struct ifnet *ifp;
227 	int disable;
228 {
229 
230 	/* Nothing. */
231 }
232 
233 void
234 if_nullwatchdog(ifp)
235 	struct ifnet *ifp;
236 {
237 
238 	/* Nothing. */
239 }
240 
241 void
242 if_nulldrain(ifp)
243 	struct ifnet *ifp;
244 {
245 
246 	/* Nothing. */
247 }
248 
249 int if_index = 0;
250 struct ifaddr **ifnet_addrs = NULL;
251 struct ifnet **ifindex2ifnet = NULL;
252 
253 /*
254  * Attach an interface to the
255  * list of "active" interfaces.
256  */
257 void
258 if_attach(ifp)
259 	struct ifnet *ifp;
260 {
261 	unsigned socksize, ifasize;
262 	int namelen, masklen;
263 	struct sockaddr_dl *sdl;
264 	struct ifaddr *ifa;
265 	static size_t if_indexlim = 8;
266 
267 	if (if_index == 0)
268 		TAILQ_INIT(&ifnet);
269 	TAILQ_INIT(&ifp->if_addrlist);
270 	TAILQ_INSERT_TAIL(&ifnet, ifp, if_list);
271 	ifp->if_index = ++if_index;
272 
273 	/*
274 	 * We have some arrays that should be indexed by if_index.
275 	 * since if_index will grow dynamically, they should grow too.
276 	 *	struct ifadd **ifnet_addrs
277 	 *	struct ifnet **ifindex2ifnet
278 	 */
279 	if (ifnet_addrs == 0 || ifindex2ifnet == 0 ||
280 	    ifp->if_index >= if_indexlim) {
281 		size_t n;
282 		caddr_t q;
283 
284 		while (ifp->if_index >= if_indexlim)
285 			if_indexlim <<= 1;
286 
287 		/* grow ifnet_addrs */
288 		n = if_indexlim * sizeof(ifa);
289 		q = (caddr_t)malloc(n, M_IFADDR, M_WAITOK);
290 		bzero(q, n);
291 		if (ifnet_addrs) {
292 			bcopy((caddr_t)ifnet_addrs, q, n/2);
293 			free((caddr_t)ifnet_addrs, M_IFADDR);
294 		}
295 		ifnet_addrs = (struct ifaddr **)q;
296 
297 		/* grow ifindex2ifnet */
298 		n = if_indexlim * sizeof(struct ifnet *);
299 		q = (caddr_t)malloc(n, M_IFADDR, M_WAITOK);
300 		bzero(q, n);
301 		if (ifindex2ifnet) {
302 			bcopy((caddr_t)ifindex2ifnet, q, n/2);
303 			free((caddr_t)ifindex2ifnet, M_IFADDR);
304 		}
305 		ifindex2ifnet = (struct ifnet **)q;
306 	}
307 
308 	ifindex2ifnet[ifp->if_index] = ifp;
309 
310 	/*
311 	 * create a Link Level name for this device
312 	 */
313 	namelen = strlen(ifp->if_xname);
314 	masklen = offsetof(struct sockaddr_dl, sdl_data[0]) + namelen;
315 	socksize = masklen + ifp->if_addrlen;
316 #define ROUNDUP(a) (1 + (((a) - 1) | (sizeof(long) - 1)))
317 	if (socksize < sizeof(*sdl))
318 		socksize = sizeof(*sdl);
319 	socksize = ROUNDUP(socksize);
320 	ifasize = sizeof(*ifa) + 2 * socksize;
321 	ifa = (struct ifaddr *)malloc(ifasize, M_IFADDR, M_WAITOK);
322 	bzero((caddr_t)ifa, ifasize);
323 	sdl = (struct sockaddr_dl *)(ifa + 1);
324 	sdl->sdl_len = socksize;
325 	sdl->sdl_family = AF_LINK;
326 	bcopy(ifp->if_xname, sdl->sdl_data, namelen);
327 	sdl->sdl_nlen = namelen;
328 	sdl->sdl_index = ifp->if_index;
329 	sdl->sdl_type = ifp->if_type;
330 	ifnet_addrs[ifp->if_index] = ifa;
331 	IFAREF(ifa);
332 	ifa->ifa_ifp = ifp;
333 	ifa->ifa_rtrequest = link_rtrequest;
334 	TAILQ_INSERT_HEAD(&ifp->if_addrlist, ifa, ifa_list);
335 	IFAREF(ifa);
336 	ifa->ifa_addr = (struct sockaddr *)sdl;
337 	ifp->if_sadl = sdl;
338 	sdl = (struct sockaddr_dl *)(socksize + (caddr_t)sdl);
339 	ifa->ifa_netmask = (struct sockaddr *)sdl;
340 	sdl->sdl_len = masklen;
341 	while (namelen != 0)
342 		sdl->sdl_data[--namelen] = 0xff;
343 	if (ifp->if_snd.ifq_maxlen == 0)
344 	    ifp->if_snd.ifq_maxlen = ifqmaxlen;
345 	ifp->if_broadcastaddr = 0; /* reliably crash if used uninitialized */
346 
347 	ifp->if_link_state = LINK_STATE_UNKNOWN;
348 
349 	/* Announce the interface. */
350 	rt_ifannouncemsg(ifp, IFAN_ARRIVAL);
351 }
352 
353 /*
354  * Deactivate an interface.  This points all of the procedure
355  * handles at error stubs.  May be called from interrupt context.
356  */
357 void
358 if_deactivate(ifp)
359 	struct ifnet *ifp;
360 {
361 	int s;
362 
363 	s = splimp();
364 
365 	ifp->if_output	 = if_nulloutput;
366 	ifp->if_input	 = if_nullinput;
367 	ifp->if_start	 = if_nullstart;
368 	ifp->if_ioctl	 = if_nullioctl;
369 	ifp->if_init	 = if_nullinit;
370 	ifp->if_stop	 = if_nullstop;
371 	ifp->if_watchdog = if_nullwatchdog;
372 	ifp->if_drain	 = if_nulldrain;
373 
374 	/* No more packets may be enqueued. */
375 	ifp->if_snd.ifq_maxlen = 0;
376 
377 	splx(s);
378 }
379 
380 /*
381  * Detach an interface from the list of "active" interfaces,
382  * freeing any resources as we go along.
383  *
384  * NOTE: This routine must be called with a valid thread context,
385  * as it may block.
386  */
387 void
388 if_detach(ifp)
389 	struct ifnet *ifp;
390 {
391 	struct socket so;
392 	struct ifaddr *ifa;
393 #ifdef IFAREF_DEBUG
394 	struct ifaddr *last_ifa = NULL;
395 #endif
396 	struct domain *dp;
397 	struct protosw *pr;
398 	struct radix_node_head *rnh;
399 	int s, i, family, purged;
400 
401 	/*
402 	 * XXX It's kind of lame that we have to have the
403 	 * XXX socket structure...
404 	 */
405 	memset(&so, 0, sizeof(so));
406 
407 	s = splimp();
408 
409 	/*
410 	 * Do an if_down() to give protocols a chance to do something.
411 	 */
412 	if_down(ifp);
413 
414 	/*
415 	 * Rip all the addresses off the interface.  This should make
416 	 * all of the routes go away.
417 	 */
418 	while ((ifa = TAILQ_FIRST(&ifp->if_addrlist)) != NULL) {
419 		family = ifa->ifa_addr->sa_family;
420 #ifdef IFAREF_DEBUG
421 		printf("if_detach: ifaddr %p, family %d, refcnt %d\n",
422 		    ifa, family, ifa->ifa_refcnt);
423 		if (last_ifa != NULL && ifa == last_ifa)
424 			panic("if_detach: loop detected");
425 		last_ifa = ifa;
426 #endif
427 		if (family == AF_LINK) {
428 			rtinit(ifa, RTM_DELETE, 0);
429 			TAILQ_REMOVE(&ifp->if_addrlist, ifa, ifa_list);
430 			IFAFREE(ifa);
431 		} else {
432 			dp = pffinddomain(family);
433 #ifdef DIAGNOSTIC
434 			if (dp == NULL)
435 				panic("if_detach: no domain for AF %d\n",
436 				    family);
437 #endif
438 			purged = 0;
439 			for (pr = dp->dom_protosw;
440 			     pr < dp->dom_protoswNPROTOSW; pr++) {
441 				so.so_proto = pr;
442 				if (pr->pr_usrreq != NULL) {
443 					(void) (*pr->pr_usrreq)(&so,
444 					    PRU_PURGEIF, NULL, NULL,
445 					    (struct mbuf *) ifp, curproc);
446 					purged = 1;
447 				}
448 			}
449 			if (purged == 0) {
450 				/*
451 				 * XXX What's really the best thing to do
452 				 * XXX here?  --thorpej@netbsd.org
453 				 */
454 				printf("if_detach: WARNING: AF %d not purged\n",
455 				    family);
456 			}
457 		}
458 	}
459 
460 	/* Walk the routing table looking for straglers. */
461 	for (i = 0; i <= AF_MAX; i++) {
462 		if ((rnh = rt_tables[i]) != NULL)
463 			(void) (*rnh->rnh_walktree)(rnh, if_rt_walktree, ifp);
464 	}
465 
466 	IFAFREE(ifnet_addrs[ifp->if_index]);
467 	ifnet_addrs[ifp->if_index] = NULL;
468 
469 	/* Announce that the interface is gone. */
470 	rt_ifannouncemsg(ifp, IFAN_DEPARTURE);
471 
472 	TAILQ_REMOVE(&ifnet, ifp, if_list);
473 
474 	splx(s);
475 }
476 
477 /*
478  * Callback for a radix tree walk to delete all references to an
479  * ifnet.
480  */
481 int
482 if_rt_walktree(rn, v)
483 	struct radix_node *rn;
484 	void *v;
485 {
486 	struct ifnet *ifp = (struct ifnet *)v;
487 	struct rtentry *rt = (struct rtentry *)rn;
488 	int error;
489 
490 	if (rt->rt_ifp == ifp) {
491 		/* Delete the entry. */
492 		error = rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway,
493 		    rt_mask(rt), rt->rt_flags, NULL);
494 		if (error)
495 			printf("%s: warning: unable to delete rtentry @ %p, "
496 			    "error = %d\n", ifp->if_xname, rt, error);
497 	}
498 	return (0);
499 }
500 
501 /*
502  * Create a clone network interface.
503  */
504 int
505 if_clone_create(name)
506 	const char *name;
507 {
508 	struct if_clone *ifc;
509 	int unit;
510 
511 	ifc = if_clone_lookup(name, &unit);
512 	if (ifc == NULL)
513 		return (EINVAL);
514 
515 	if (ifunit(name) != NULL)
516 		return (EEXIST);
517 
518 	return ((*ifc->ifc_create)(ifc, unit));
519 }
520 
521 /*
522  * Destroy a clone network interface.
523  */
524 int
525 if_clone_destroy(name)
526 	const char *name;
527 {
528 	struct if_clone *ifc;
529 	struct ifnet *ifp;
530 
531 	ifc = if_clone_lookup(name, NULL);
532 	if (ifc == NULL)
533 		return (EINVAL);
534 
535 	ifp = ifunit(name);
536 	if (ifp == NULL)
537 		return (ENXIO);
538 
539 	if (ifc->ifc_destroy == NULL)
540 		return (EOPNOTSUPP);
541 
542 	(*ifc->ifc_destroy)(ifp);
543 	return (0);
544 }
545 
546 /*
547  * Look up a network interface cloner.
548  */
549 struct if_clone *
550 if_clone_lookup(name, unitp)
551 	const char *name;
552 	int *unitp;
553 {
554 	struct if_clone *ifc;
555 	const char *cp;
556 	int i;
557 
558 	for (ifc = LIST_FIRST(&if_cloners); ifc != NULL;) {
559 		for (cp = name, i = 0; i < ifc->ifc_namelen; i++, cp++) {
560 			if (ifc->ifc_name[i] != *cp)
561 				goto next_ifc;
562 		}
563 		goto found_name;
564  next_ifc:
565 		ifc = LIST_NEXT(ifc, ifc_list);
566 	}
567 
568 	/* No match. */
569 	return (NULL);
570 
571  found_name:
572 	for (i = 0; *cp != '\0'; cp++) {
573 		if (*cp < '0' || *cp > '9') {
574 			/* Bogus unit number. */
575 			return (NULL);
576 		}
577 		i = (i * 10) + (*cp - '0');
578 	}
579 
580 	if (unitp != NULL)
581 		*unitp = i;
582 	return (ifc);
583 }
584 
585 /*
586  * Register a network interface cloner.
587  */
588 void
589 if_clone_attach(ifc)
590 	struct if_clone *ifc;
591 {
592 
593 	LIST_INSERT_HEAD(&if_cloners, ifc, ifc_list);
594 	if_cloners_count++;
595 }
596 
597 /*
598  * Unregister a network interface cloner.
599  */
600 void
601 if_clone_detach(ifc)
602 	struct if_clone *ifc;
603 {
604 
605 	LIST_REMOVE(ifc, ifc_list);
606 	if_cloners_count--;
607 }
608 
609 /*
610  * Provide list of interface cloners to userspace.
611  */
612 int
613 if_clone_list(ifcr)
614 	struct if_clonereq *ifcr;
615 {
616 	char outbuf[IFNAMSIZ], *dst;
617 	struct if_clone *ifc;
618 	int count, error = 0;
619 
620 	ifcr->ifcr_total = if_cloners_count;
621 	if ((dst = ifcr->ifcr_buffer) == NULL) {
622 		/* Just asking how many there are. */
623 		return (0);
624 	}
625 
626 	if (ifcr->ifcr_count < 0)
627 		return (EINVAL);
628 
629 	count = (if_cloners_count < ifcr->ifcr_count) ?
630 	    if_cloners_count : ifcr->ifcr_count;
631 
632 	for (ifc = LIST_FIRST(&if_cloners); ifc != NULL && count != 0;
633 	     ifc = LIST_NEXT(ifc, ifc_list), count--, dst += IFNAMSIZ) {
634 		strncpy(outbuf, ifc->ifc_name, IFNAMSIZ);
635 		outbuf[IFNAMSIZ - 1] = '\0';	/* sanity */
636 		error = copyout(outbuf, dst, IFNAMSIZ);
637 		if (error)
638 			break;
639 	}
640 
641 	return (error);
642 }
643 
644 /*
645  * Locate an interface based on a complete address.
646  */
647 /*ARGSUSED*/
648 struct ifaddr *
649 ifa_ifwithaddr(addr)
650 	struct sockaddr *addr;
651 {
652 	struct ifnet *ifp;
653 	struct ifaddr *ifa;
654 
655 #define	equal(a1, a2) \
656   (bcmp((caddr_t)(a1), (caddr_t)(a2), ((struct sockaddr *)(a1))->sa_len) == 0)
657 
658 	for (ifp = TAILQ_FIRST(&ifnet); ifp != NULL;
659 	     ifp = TAILQ_NEXT(ifp, if_list)) {
660 		if (ifp->if_output == if_nulloutput)
661 			continue;
662 		for (ifa = TAILQ_FIRST(&ifp->if_addrlist); ifa != NULL;
663 		     ifa = TAILQ_NEXT(ifa, ifa_list)) {
664 			if (ifa->ifa_addr->sa_family != addr->sa_family)
665 				continue;
666 			if (equal(addr, ifa->ifa_addr))
667 				return (ifa);
668 			if ((ifp->if_flags & IFF_BROADCAST) &&
669 			    ifa->ifa_broadaddr &&
670 			    /* IP6 doesn't have broadcast */
671 			    ifa->ifa_broadaddr->sa_len != 0 &&
672 			    equal(ifa->ifa_broadaddr, addr))
673 				return (ifa);
674 		}
675 	}
676 	return (NULL);
677 }
678 
679 /*
680  * Locate the point to point interface with a given destination address.
681  */
682 /*ARGSUSED*/
683 struct ifaddr *
684 ifa_ifwithdstaddr(addr)
685 	struct sockaddr *addr;
686 {
687 	struct ifnet *ifp;
688 	struct ifaddr *ifa;
689 
690 	for (ifp = TAILQ_FIRST(&ifnet); ifp != NULL;
691 	     ifp = TAILQ_NEXT(ifp, if_list)) {
692 		if (ifp->if_output == if_nulloutput)
693 			continue;
694 		if (ifp->if_flags & IFF_POINTOPOINT) {
695 			for (ifa = TAILQ_FIRST(&ifp->if_addrlist); ifa != NULL;
696 			     ifa = TAILQ_NEXT(ifa, ifa_list)) {
697 				if (ifa->ifa_addr->sa_family !=
698 				      addr->sa_family ||
699 				    ifa->ifa_dstaddr == NULL)
700 					continue;
701 				if (equal(addr, ifa->ifa_dstaddr))
702 					return (ifa);
703 			}
704 		}
705 	}
706 	return (NULL);
707 }
708 
709 /*
710  * Find an interface on a specific network.  If many, choice
711  * is most specific found.
712  */
713 struct ifaddr *
714 ifa_ifwithnet(addr)
715 	struct sockaddr *addr;
716 {
717 	struct ifnet *ifp;
718 	struct ifaddr *ifa;
719 	struct sockaddr_dl *sdl;
720 	struct ifaddr *ifa_maybe = 0;
721 	u_int af = addr->sa_family;
722 	char *addr_data = addr->sa_data, *cplim;
723 
724 	if (af == AF_LINK) {
725 		sdl = (struct sockaddr_dl *)addr;
726 		if (sdl->sdl_index && sdl->sdl_index <= if_index &&
727 		    ifindex2ifnet[sdl->sdl_index]->if_output != if_nulloutput)
728 			return (ifnet_addrs[sdl->sdl_index]);
729 	}
730 #ifdef NETATALK
731 	if (af == AF_APPLETALK) {
732 		struct sockaddr_at *sat, *sat2;
733 		sat = (struct sockaddr_at *)addr;
734 		for (ifp = TAILQ_FIRST(&ifnet); ifp != NULL;
735 		     ifp = TAILQ_NEXT(ifp, if_list)) {
736 			if (ifp->if_output == if_nulloutput)
737 				continue;
738 			ifa = at_ifawithnet((struct sockaddr_at *)addr, ifp);
739 			if (ifa == NULL)
740 				continue;
741 			sat2 = (struct sockaddr_at *)ifa->ifa_addr;
742 			if (sat2->sat_addr.s_net == sat->sat_addr.s_net)
743 				return (ifa); /* exact match */
744 			if (ifa_maybe == NULL) {
745 				/* else keep the if with the rigth range */
746 				ifa_maybe = ifa;
747 			}
748 		}
749 		return (ifa_maybe);
750 	}
751 #endif
752 	for (ifp = TAILQ_FIRST(&ifnet); ifp != NULL;
753 	     ifp = TAILQ_NEXT(ifp, if_list)) {
754 		if (ifp->if_output == if_nulloutput)
755 			continue;
756 		for (ifa = TAILQ_FIRST(&ifp->if_addrlist); ifa != NULL;
757 		     ifa = TAILQ_NEXT(ifa, ifa_list)) {
758 			char *cp, *cp2, *cp3;
759 
760 			if (ifa->ifa_addr->sa_family != af ||
761 			    ifa->ifa_netmask == 0)
762  next:				continue;
763 			cp = addr_data;
764 			cp2 = ifa->ifa_addr->sa_data;
765 			cp3 = ifa->ifa_netmask->sa_data;
766 			cplim = (char *)ifa->ifa_netmask +
767 			    ifa->ifa_netmask->sa_len;
768 			while (cp3 < cplim) {
769 				if ((*cp++ ^ *cp2++) & *cp3++) {
770 					/* want to continue for() loop */
771 					goto next;
772 				}
773 			}
774 			if (ifa_maybe == 0 ||
775 			    rn_refines((caddr_t)ifa->ifa_netmask,
776 			    (caddr_t)ifa_maybe->ifa_netmask))
777 				ifa_maybe = ifa;
778 		}
779 	}
780 	return (ifa_maybe);
781 }
782 
783 /*
784  * Find the interface of the addresss.
785  */
786 struct ifaddr *
787 ifa_ifwithladdr(addr)
788 	struct sockaddr *addr;
789 {
790 	struct ifaddr *ia;
791 
792 	if ((ia = ifa_ifwithaddr(addr)) || (ia = ifa_ifwithdstaddr(addr)) ||
793 	    (ia = ifa_ifwithnet(addr)))
794 		return (ia);
795 	return (NULL);
796 }
797 
798 /*
799  * Find an interface using a specific address family
800  */
801 struct ifaddr *
802 ifa_ifwithaf(af)
803 	int af;
804 {
805 	struct ifnet *ifp;
806 	struct ifaddr *ifa;
807 
808 	for (ifp = TAILQ_FIRST(&ifnet); ifp != NULL;
809 	     ifp = TAILQ_NEXT(ifp, if_list)) {
810 		if (ifp->if_output == if_nulloutput)
811 			continue;
812 		for (ifa = TAILQ_FIRST(&ifp->if_addrlist); ifa != NULL;
813 		     ifa = TAILQ_NEXT(ifa, ifa_list)) {
814 			if (ifa->ifa_addr->sa_family == af)
815 				return (ifa);
816 		}
817 	}
818 	return (NULL);
819 }
820 
821 /*
822  * Find an interface address specific to an interface best matching
823  * a given address.
824  */
825 struct ifaddr *
826 ifaof_ifpforaddr(addr, ifp)
827 	struct sockaddr *addr;
828 	struct ifnet *ifp;
829 {
830 	struct ifaddr *ifa;
831 	char *cp, *cp2, *cp3;
832 	char *cplim;
833 	struct ifaddr *ifa_maybe = 0;
834 	u_int af = addr->sa_family;
835 
836 	if (ifp->if_output == if_nulloutput)
837 		return (NULL);
838 
839 	if (af >= AF_MAX)
840 		return (NULL);
841 
842 	for (ifa = TAILQ_FIRST(&ifp->if_addrlist); ifa != NULL;
843 	     ifa = TAILQ_NEXT(ifa, ifa_list)) {
844 		if (ifa->ifa_addr->sa_family != af)
845 			continue;
846 		ifa_maybe = ifa;
847 		if (ifa->ifa_netmask == 0) {
848 			if (equal(addr, ifa->ifa_addr) ||
849 			    (ifa->ifa_dstaddr &&
850 			     equal(addr, ifa->ifa_dstaddr)))
851 				return (ifa);
852 			continue;
853 		}
854 		cp = addr->sa_data;
855 		cp2 = ifa->ifa_addr->sa_data;
856 		cp3 = ifa->ifa_netmask->sa_data;
857 		cplim = ifa->ifa_netmask->sa_len + (char *)ifa->ifa_netmask;
858 		for (; cp3 < cplim; cp3++) {
859 			if ((*cp++ ^ *cp2++) & *cp3)
860 				break;
861 		}
862 		if (cp3 == cplim)
863 			return (ifa);
864 	}
865 	return (ifa_maybe);
866 }
867 
868 /*
869  * Default action when installing a route with a Link Level gateway.
870  * Lookup an appropriate real ifa to point to.
871  * This should be moved to /sys/net/link.c eventually.
872  */
873 void
874 link_rtrequest(cmd, rt, sa)
875 	int cmd;
876 	struct rtentry *rt;
877 	struct sockaddr *sa;
878 {
879 	struct ifaddr *ifa;
880 	struct sockaddr *dst;
881 	struct ifnet *ifp;
882 
883 	if (cmd != RTM_ADD || ((ifa = rt->rt_ifa) == 0) ||
884 	    ((ifp = ifa->ifa_ifp) == 0) || ((dst = rt_key(rt)) == 0))
885 		return;
886 	if ((ifa = ifaof_ifpforaddr(dst, ifp)) != NULL) {
887 		IFAFREE(rt->rt_ifa);
888 		rt->rt_ifa = ifa;
889 		IFAREF(ifa);
890 		if (ifa->ifa_rtrequest && ifa->ifa_rtrequest != link_rtrequest)
891 			ifa->ifa_rtrequest(cmd, rt, sa);
892 	}
893 }
894 
895 /*
896  * Mark an interface down and notify protocols of
897  * the transition.
898  * NOTE: must be called at splsoftnet or equivalent.
899  */
900 void
901 if_down(ifp)
902 	struct ifnet *ifp;
903 {
904 	struct ifaddr *ifa;
905 
906 	ifp->if_flags &= ~IFF_UP;
907 	for (ifa = TAILQ_FIRST(&ifp->if_addrlist); ifa != NULL;
908 	     ifa = TAILQ_NEXT(ifa, ifa_list))
909 		pfctlinput(PRC_IFDOWN, ifa->ifa_addr);
910 	IFQ_PURGE(&ifp->if_snd);
911 	rt_ifmsg(ifp);
912 }
913 
914 /*
915  * Mark an interface up and notify protocols of
916  * the transition.
917  * NOTE: must be called at splsoftnet or equivalent.
918  */
919 void
920 if_up(ifp)
921 	struct ifnet *ifp;
922 {
923 #ifdef notyet
924 	struct ifaddr *ifa;
925 #endif
926 
927 	ifp->if_flags |= IFF_UP;
928 #ifdef notyet
929 	/* this has no effect on IP, and will kill all ISO connections XXX */
930 	for (ifa = TAILQ_FIRST(&ifp->if_addrlist); ifa != NULL;
931 	     ifa = TAILQ_NEXT(ifa, ifa_list))
932 		pfctlinput(PRC_IFUP, ifa->ifa_addr);
933 #endif
934 	rt_ifmsg(ifp);
935 #ifdef INET6
936 	in6_if_up(ifp);
937 #endif
938 }
939 
940 /*
941  * Handle interface watchdog timer routines.  Called
942  * from softclock, we decrement timers (if set) and
943  * call the appropriate interface routine on expiration.
944  */
945 void
946 if_slowtimo(arg)
947 	void *arg;
948 {
949 	struct ifnet *ifp;
950 	int s = splimp();
951 
952 	for (ifp = TAILQ_FIRST(&ifnet); ifp != NULL;
953 	     ifp = TAILQ_NEXT(ifp, if_list)) {
954 		if (ifp->if_timer == 0 || --ifp->if_timer)
955 			continue;
956 		if (ifp->if_watchdog)
957 			(*ifp->if_watchdog)(ifp);
958 	}
959 	splx(s);
960 	callout_reset(&if_slowtimo_ch, hz / IFNET_SLOWHZ,
961 	    if_slowtimo, NULL);
962 }
963 
964 /*
965  * Set/clear promiscuous mode on interface ifp based on the truth value
966  * of pswitch.  The calls are reference counted so that only the first
967  * "on" request actually has an effect, as does the final "off" request.
968  * Results are undefined if the "off" and "on" requests are not matched.
969  */
970 int
971 ifpromisc(ifp, pswitch)
972 	struct ifnet *ifp;
973 	int pswitch;
974 {
975 	int pcount, ret;
976 	short flags;
977 	struct ifreq ifr;
978 
979 	pcount = ifp->if_pcount;
980 	flags = ifp->if_flags;
981 	if (pswitch) {
982 		/*
983 		 * Allow the device to be "placed" into promiscuous
984 		 * mode even if it is not configured up.  It will
985 		 * consult IFF_PROMISC when it is is brought up.
986 		 */
987 		if (ifp->if_pcount++ != 0)
988 			return (0);
989 		ifp->if_flags |= IFF_PROMISC;
990 		if ((ifp->if_flags & IFF_UP) == 0)
991 			return (0);
992 	} else {
993 		if (--ifp->if_pcount > 0)
994 			return (0);
995 		ifp->if_flags &= ~IFF_PROMISC;
996 		/*
997 		 * If the device is not configured up, we should not need to
998 		 * turn off promiscuous mode (device should have turned it
999 		 * off when interface went down; and will look at IFF_PROMISC
1000 		 * again next time interface comes up).
1001 		 */
1002 		if ((ifp->if_flags & IFF_UP) == 0)
1003 			return (0);
1004 	}
1005 	memset(&ifr, 0, sizeof(ifr));
1006 	ifr.ifr_flags = ifp->if_flags;
1007 	ret = (*ifp->if_ioctl)(ifp, SIOCSIFFLAGS, (caddr_t) &ifr);
1008 	/* Restore interface state if not successful. */
1009 	if (ret != 0) {
1010 		ifp->if_pcount = pcount;
1011 		ifp->if_flags = flags;
1012 	}
1013 	return (ret);
1014 }
1015 
1016 /*
1017  * Map interface name to
1018  * interface structure pointer.
1019  */
1020 struct ifnet *
1021 ifunit(name)
1022 	const char *name;
1023 {
1024 	struct ifnet *ifp;
1025 
1026 	for (ifp = TAILQ_FIRST(&ifnet); ifp != NULL;
1027 	     ifp = TAILQ_NEXT(ifp, if_list)) {
1028 		if (ifp->if_output == if_nulloutput)
1029 			continue;
1030 	 	if (strcmp(ifp->if_xname, name) == 0)
1031 			return (ifp);
1032 	}
1033 	return (NULL);
1034 }
1035 
1036 /*
1037  * Interface ioctls.
1038  */
1039 int
1040 ifioctl(so, cmd, data, p)
1041 	struct socket *so;
1042 	u_long cmd;
1043 	caddr_t data;
1044 	struct proc *p;
1045 {
1046 	struct ifnet *ifp;
1047 	struct ifreq *ifr;
1048 	int error = 0;
1049 	short oif_flags;
1050 
1051 	switch (cmd) {
1052 
1053 	case SIOCGIFCONF:
1054 	case OSIOCGIFCONF:
1055 		return (ifconf(cmd, data));
1056 	}
1057 	ifr = (struct ifreq *)data;
1058 
1059 	switch (cmd) {
1060 	case SIOCIFCREATE:
1061 	case SIOCIFDESTROY:
1062 		if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
1063 			return (error);
1064 		return ((cmd == SIOCIFCREATE) ?
1065 			if_clone_create(ifr->ifr_name) :
1066 			if_clone_destroy(ifr->ifr_name));
1067 
1068 	case SIOCIFGCLONERS:
1069 		return (if_clone_list((struct if_clonereq *)data));
1070 	}
1071 
1072 	ifp = ifunit(ifr->ifr_name);
1073 	if (ifp == 0)
1074 		return (ENXIO);
1075 	oif_flags = ifp->if_flags;
1076 	switch (cmd) {
1077 
1078 	case SIOCGIFFLAGS:
1079 		ifr->ifr_flags = ifp->if_flags;
1080 		break;
1081 
1082 	case SIOCGIFMETRIC:
1083 		ifr->ifr_metric = ifp->if_metric;
1084 		break;
1085 
1086 	case SIOCGIFMTU:
1087 		ifr->ifr_mtu = ifp->if_mtu;
1088 		break;
1089 
1090 	case SIOCGIFDLT:
1091 		ifr->ifr_dlt = ifp->if_dlt;
1092 		break;
1093 
1094 	case SIOCSIFFLAGS:
1095 		if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
1096 			return (error);
1097 		if (ifp->if_flags & IFF_UP && (ifr->ifr_flags & IFF_UP) == 0) {
1098 			int s = splimp();
1099 			if_down(ifp);
1100 			splx(s);
1101 		}
1102 		if (ifr->ifr_flags & IFF_UP && (ifp->if_flags & IFF_UP) == 0) {
1103 			int s = splimp();
1104 			if_up(ifp);
1105 			splx(s);
1106 		}
1107 		ifp->if_flags = (ifp->if_flags & IFF_CANTCHANGE) |
1108 			(ifr->ifr_flags &~ IFF_CANTCHANGE);
1109 		if (ifp->if_ioctl)
1110 			(void) (*ifp->if_ioctl)(ifp, cmd, data);
1111 		break;
1112 
1113 	case SIOCSIFMETRIC:
1114 		if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
1115 			return (error);
1116 		ifp->if_metric = ifr->ifr_metric;
1117 		break;
1118 
1119 	case SIOCSIFMTU:
1120 	{
1121 		u_long oldmtu = ifp->if_mtu;
1122 
1123 		error = suser(p->p_ucred, &p->p_acflag);
1124 		if (error)
1125 			return (error);
1126 		if (ifp->if_ioctl == NULL)
1127 			return (EOPNOTSUPP);
1128 		error = (*ifp->if_ioctl)(ifp, cmd, data);
1129 
1130 		/*
1131 		 * If the link MTU changed, do network layer specific procedure.
1132 		 */
1133 		if (ifp->if_mtu != oldmtu) {
1134 #ifdef INET6
1135 			nd6_setmtu(ifp);
1136 #endif
1137 		}
1138 		break;
1139 	}
1140 	case SIOCSIFPHYADDR:
1141 	case SIOCDIFPHYADDR:
1142 #ifdef INET6
1143 	case SIOCSIFPHYADDR_IN6:
1144 #endif
1145 	case SIOCADDMULTI:
1146 	case SIOCDELMULTI:
1147 	case SIOCSIFMEDIA:
1148 		if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
1149 			return (error);
1150 		/* FALLTHROUGH */
1151 	case SIOCGIFPSRCADDR:
1152 	case SIOCGIFPDSTADDR:
1153 	case SIOCGIFMEDIA:
1154 		if (ifp->if_ioctl == 0)
1155 			return (EOPNOTSUPP);
1156 		error = (*ifp->if_ioctl)(ifp, cmd, data);
1157 		break;
1158 
1159 	case SIOCSDRVSPEC:
1160 	case SIOCS80211NWID:
1161 	case SIOCS80211NWKEY:
1162 	case SIOCS80211POWER:
1163 		/* XXX:  need to pass proc pointer through to driver... */
1164 		if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
1165 			return (error);
1166 	/* FALLTHROUGH */
1167 	default:
1168 		if (so->so_proto == 0)
1169 			return (EOPNOTSUPP);
1170 #if !defined(COMPAT_43) && !defined(COMPAT_LINUX) && !defined(COMPAT_SVR4)
1171 		error = ((*so->so_proto->pr_usrreq)(so, PRU_CONTROL,
1172 		    (struct mbuf *)cmd, (struct mbuf *)data,
1173 		    (struct mbuf *)ifp, p));
1174 #else
1175 	    {
1176 		int ocmd = cmd;
1177 
1178 		switch (cmd) {
1179 
1180 		case SIOCSIFADDR:
1181 		case SIOCSIFDSTADDR:
1182 		case SIOCSIFBRDADDR:
1183 		case SIOCSIFNETMASK:
1184 #if BYTE_ORDER != BIG_ENDIAN
1185 			if (ifr->ifr_addr.sa_family == 0 &&
1186 			    ifr->ifr_addr.sa_len < 16) {
1187 				ifr->ifr_addr.sa_family = ifr->ifr_addr.sa_len;
1188 				ifr->ifr_addr.sa_len = 16;
1189 			}
1190 #else
1191 			if (ifr->ifr_addr.sa_len == 0)
1192 				ifr->ifr_addr.sa_len = 16;
1193 #endif
1194 			break;
1195 
1196 		case OSIOCGIFADDR:
1197 			cmd = SIOCGIFADDR;
1198 			break;
1199 
1200 		case OSIOCGIFDSTADDR:
1201 			cmd = SIOCGIFDSTADDR;
1202 			break;
1203 
1204 		case OSIOCGIFBRDADDR:
1205 			cmd = SIOCGIFBRDADDR;
1206 			break;
1207 
1208 		case OSIOCGIFNETMASK:
1209 			cmd = SIOCGIFNETMASK;
1210 		}
1211 
1212 		error = ((*so->so_proto->pr_usrreq)(so, PRU_CONTROL,
1213 		    (struct mbuf *)cmd, (struct mbuf *)data,
1214 		    (struct mbuf *)ifp, p));
1215 
1216 		switch (ocmd) {
1217 		case OSIOCGIFADDR:
1218 		case OSIOCGIFDSTADDR:
1219 		case OSIOCGIFBRDADDR:
1220 		case OSIOCGIFNETMASK:
1221 			*(u_int16_t *)&ifr->ifr_addr = ifr->ifr_addr.sa_family;
1222 		}
1223 	    }
1224 #endif /* COMPAT_43 */
1225 		break;
1226 	}
1227 
1228 	if (((oif_flags ^ ifp->if_flags) & IFF_UP) != 0) {
1229 #ifdef INET6
1230 		if ((ifp->if_flags & IFF_UP) != 0) {
1231 			int s = splimp();
1232 			in6_if_up(ifp);
1233 			splx(s);
1234 		}
1235 #endif
1236 	}
1237 
1238 	return (error);
1239 }
1240 
1241 /*
1242  * Return interface configuration
1243  * of system.  List may be used
1244  * in later ioctl's (above) to get
1245  * other information.
1246  */
1247 /*ARGSUSED*/
1248 int
1249 ifconf(cmd, data)
1250 	u_long cmd;
1251 	caddr_t data;
1252 {
1253 	struct ifconf *ifc = (struct ifconf *)data;
1254 	struct ifnet *ifp;
1255 	struct ifaddr *ifa;
1256 	struct ifreq ifr, *ifrp;
1257 	int space = ifc->ifc_len, error = 0;
1258 
1259 	ifrp = ifc->ifc_req;
1260 	for (ifp = ifnet.tqh_first; ifp != 0; ifp = ifp->if_list.tqe_next) {
1261 		bcopy(ifp->if_xname, ifr.ifr_name, IFNAMSIZ);
1262 		if ((ifa = ifp->if_addrlist.tqh_first) == 0) {
1263 			bzero((caddr_t)&ifr.ifr_addr, sizeof(ifr.ifr_addr));
1264 			if (space >= (int)sizeof (ifr)) {
1265 				error = copyout((caddr_t)&ifr, (caddr_t)ifrp,
1266 						sizeof(ifr));
1267 				if (error)
1268 					break;
1269 			}
1270 			space -= sizeof (ifr), ifrp++;
1271 		} else
1272 		    for (; ifa != 0; ifa = ifa->ifa_list.tqe_next) {
1273 			struct sockaddr *sa = ifa->ifa_addr;
1274 #if defined(COMPAT_43) || defined(COMPAT_LINUX) || defined(COMPAT_SVR4)
1275 			if (cmd == OSIOCGIFCONF) {
1276 				struct osockaddr *osa =
1277 					 (struct osockaddr *)&ifr.ifr_addr;
1278 				ifr.ifr_addr = *sa;
1279 				osa->sa_family = sa->sa_family;
1280 				if (space >= (int)sizeof (ifr)) {
1281 					error = copyout((caddr_t)&ifr,
1282 							(caddr_t)ifrp,
1283 							sizeof (ifr));
1284 					ifrp++;
1285 				}
1286 			} else
1287 #endif
1288 			if (sa->sa_len <= sizeof(*sa)) {
1289 				ifr.ifr_addr = *sa;
1290 				if (space >= (int)sizeof (ifr)) {
1291 					error = copyout((caddr_t)&ifr,
1292 							(caddr_t)ifrp,
1293 							sizeof (ifr));
1294 					ifrp++;
1295 				}
1296 			} else {
1297 				space -= sa->sa_len - sizeof(*sa);
1298 				if (space >= (int)sizeof (ifr)) {
1299 					error = copyout((caddr_t)&ifr,
1300 							(caddr_t)ifrp,
1301 							sizeof (ifr.ifr_name));
1302 					if (error == 0) {
1303 						error = copyout((caddr_t)sa,
1304 						  (caddr_t)&ifrp->ifr_addr,
1305 						  sa->sa_len);
1306 					}
1307 					ifrp = (struct ifreq *)
1308 						(sa->sa_len +
1309 						 (caddr_t)&ifrp->ifr_addr);
1310 				}
1311 			}
1312 			if (error)
1313 				break;
1314 			space -= sizeof (ifr);
1315 		}
1316 	}
1317 	ifc->ifc_len -= space;
1318 	return (error);
1319 }
1320