xref: /netbsd-src/sys/net/if.c (revision 7c7c171d130af9949261bc7dce2150a03c3d239c)
1 /*	$NetBSD: if.c,v 1.44 1998/03/01 02:25:04 fvdl Exp $	*/
2 
3 /*
4  * Copyright (c) 1980, 1986, 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 acknowledgement:
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  *	@(#)if.c	8.5 (Berkeley) 1/9/95
36  */
37 
38 #include <sys/param.h>
39 #include <sys/mbuf.h>
40 #include <sys/systm.h>
41 #include <sys/proc.h>
42 #include <sys/socket.h>
43 #include <sys/socketvar.h>
44 #include <sys/protosw.h>
45 #include <sys/kernel.h>
46 #include <sys/ioctl.h>
47 
48 #include <net/if.h>
49 #include <net/if_dl.h>
50 #include <net/if_types.h>
51 #include <net/radix.h>
52 
53 int	ifqmaxlen = IFQ_MAXLEN;
54 void	if_slowtimo __P((void *arg));
55 
56 /*
57  * Network interface utility routines.
58  *
59  * Routines with ifa_ifwith* names take sockaddr *'s as
60  * parameters.
61  */
62 void
63 ifinit()
64 {
65 
66 	if_slowtimo(NULL);
67 }
68 
69 int if_index = 0;
70 struct ifaddr **ifnet_addrs;
71 
72 /*
73  * Attach an interface to the
74  * list of "active" interfaces.
75  */
76 void
77 if_attach(ifp)
78 	struct ifnet *ifp;
79 {
80 	unsigned socksize, ifasize;
81 	int namelen, masklen;
82 	register struct sockaddr_dl *sdl;
83 	register struct ifaddr *ifa;
84 	static int if_indexlim = 8;
85 
86 	if (if_index == 0)
87 		TAILQ_INIT(&ifnet);
88 	TAILQ_INIT(&ifp->if_addrlist);
89 	TAILQ_INSERT_TAIL(&ifnet, ifp, if_list);
90 	ifp->if_index = ++if_index;
91 	if (ifnet_addrs == 0 || if_index >= if_indexlim) {
92 		unsigned n = (if_indexlim <<= 1) * sizeof(ifa);
93 		struct ifaddr **q = (struct ifaddr **)
94 					malloc(n, M_IFADDR, M_WAITOK);
95 		if (ifnet_addrs) {
96 			bcopy((caddr_t)ifnet_addrs, (caddr_t)q, n/2);
97 			free((caddr_t)ifnet_addrs, M_IFADDR);
98 		}
99 		ifnet_addrs = q;
100 	}
101 	/*
102 	 * create a Link Level name for this device
103 	 */
104 	namelen = strlen(ifp->if_xname);
105 	masklen = offsetof(struct sockaddr_dl, sdl_data[0]) + namelen;
106 	socksize = masklen + ifp->if_addrlen;
107 #define ROUNDUP(a) (1 + (((a) - 1) | (sizeof(long) - 1)))
108 	if (socksize < sizeof(*sdl))
109 		socksize = sizeof(*sdl);
110 	socksize = ROUNDUP(socksize);
111 	ifasize = sizeof(*ifa) + 2 * socksize;
112 	ifa = (struct ifaddr *)malloc(ifasize, M_IFADDR, M_WAITOK);
113 	bzero((caddr_t)ifa, ifasize);
114 	sdl = (struct sockaddr_dl *)(ifa + 1);
115 	sdl->sdl_len = socksize;
116 	sdl->sdl_family = AF_LINK;
117 	bcopy(ifp->if_xname, sdl->sdl_data, namelen);
118 	sdl->sdl_nlen = namelen;
119 	sdl->sdl_index = ifp->if_index;
120 	sdl->sdl_type = ifp->if_type;
121 	ifnet_addrs[if_index - 1] = ifa;
122 	ifa->ifa_ifp = ifp;
123 	ifa->ifa_rtrequest = link_rtrequest;
124 	TAILQ_INSERT_HEAD(&ifp->if_addrlist, ifa, ifa_list);
125 	ifa->ifa_addr = (struct sockaddr *)sdl;
126 	ifp->if_sadl = sdl;
127 	sdl = (struct sockaddr_dl *)(socksize + (caddr_t)sdl);
128 	ifa->ifa_netmask = (struct sockaddr *)sdl;
129 	sdl->sdl_len = masklen;
130 	while (namelen != 0)
131 		sdl->sdl_data[--namelen] = 0xff;
132 	if (ifp->if_snd.ifq_maxlen == 0)
133 	    ifp->if_snd.ifq_maxlen = ifqmaxlen;
134 	ifp->if_broadcastaddr = 0; /* reliably crash if used uninitialized */
135 }
136 /*
137  * Locate an interface based on a complete address.
138  */
139 /*ARGSUSED*/
140 struct ifaddr *
141 ifa_ifwithaddr(addr)
142 	register struct sockaddr *addr;
143 {
144 	register struct ifnet *ifp;
145 	register struct ifaddr *ifa;
146 
147 #define	equal(a1, a2) \
148   (bcmp((caddr_t)(a1), (caddr_t)(a2), ((struct sockaddr *)(a1))->sa_len) == 0)
149 	for (ifp = ifnet.tqh_first; ifp != 0; ifp = ifp->if_list.tqe_next)
150 	    for (ifa = ifp->if_addrlist.tqh_first; ifa != 0; ifa = ifa->ifa_list.tqe_next) {
151 		if (ifa->ifa_addr->sa_family != addr->sa_family)
152 			continue;
153 		if (equal(addr, ifa->ifa_addr))
154 			return (ifa);
155 		if ((ifp->if_flags & IFF_BROADCAST) && ifa->ifa_broadaddr &&
156 		    equal(ifa->ifa_broadaddr, addr))
157 			return (ifa);
158 	}
159 	return ((struct ifaddr *)0);
160 }
161 /*
162  * Locate the point to point interface with a given destination address.
163  */
164 /*ARGSUSED*/
165 struct ifaddr *
166 ifa_ifwithdstaddr(addr)
167 	register struct sockaddr *addr;
168 {
169 	register struct ifnet *ifp;
170 	register struct ifaddr *ifa;
171 
172 	for (ifp = ifnet.tqh_first; ifp != 0; ifp = ifp->if_list.tqe_next)
173 	    if (ifp->if_flags & IFF_POINTOPOINT)
174 		for (ifa = ifp->if_addrlist.tqh_first; ifa != 0; ifa = ifa->ifa_list.tqe_next) {
175 			if (ifa->ifa_addr->sa_family != addr->sa_family ||
176 			    ifa->ifa_dstaddr == NULL)
177 				continue;
178 			if (equal(addr, ifa->ifa_dstaddr))
179 				return (ifa);
180 	}
181 	return ((struct ifaddr *)0);
182 }
183 
184 /*
185  * Find an interface on a specific network.  If many, choice
186  * is most specific found.
187  */
188 struct ifaddr *
189 ifa_ifwithnet(addr)
190 	struct sockaddr *addr;
191 {
192 	register struct ifnet *ifp;
193 	register struct ifaddr *ifa;
194 	struct ifaddr *ifa_maybe = 0;
195 	u_int af = addr->sa_family;
196 	char *addr_data = addr->sa_data, *cplim;
197 
198 	if (af == AF_LINK) {
199 	    register struct sockaddr_dl *sdl = (struct sockaddr_dl *)addr;
200 	    if (sdl->sdl_index && sdl->sdl_index <= if_index)
201 		return (ifnet_addrs[sdl->sdl_index - 1]);
202 	}
203 	for (ifp = ifnet.tqh_first; ifp != 0; ifp = ifp->if_list.tqe_next)
204 		for (ifa = ifp->if_addrlist.tqh_first; ifa != 0; ifa = ifa->ifa_list.tqe_next) {
205 			register char *cp, *cp2, *cp3;
206 
207 			if (ifa->ifa_addr->sa_family != af ||
208 			    ifa->ifa_netmask == 0)
209 				next: continue;
210 			cp = addr_data;
211 			cp2 = ifa->ifa_addr->sa_data;
212 			cp3 = ifa->ifa_netmask->sa_data;
213 			cplim = (char *)ifa->ifa_netmask +
214 				ifa->ifa_netmask->sa_len;
215 			while (cp3 < cplim)
216 				if ((*cp++ ^ *cp2++) & *cp3++)
217 				    /* want to continue for() loop */
218 					goto next;
219 			if (ifa_maybe == 0 ||
220 			    rn_refines((caddr_t)ifa->ifa_netmask,
221 			    (caddr_t)ifa_maybe->ifa_netmask))
222 				ifa_maybe = ifa;
223 		}
224 	return (ifa_maybe);
225 }
226 /*
227  * Find the interface of the addresss.
228  */
229 struct ifaddr *
230 ifa_ifwithladdr(addr)
231 	struct sockaddr *addr;
232 {
233 	struct ifaddr *ia;
234 
235 	if ((ia = ifa_ifwithaddr(addr)) || (ia = ifa_ifwithdstaddr(addr))
236 	    || (ia = ifa_ifwithnet(addr)))
237 		return (ia);
238 	return (NULL);
239 }
240 
241 /*
242  * Find an interface using a specific address family
243  */
244 struct ifaddr *
245 ifa_ifwithaf(af)
246 	register int af;
247 {
248 	register struct ifnet *ifp;
249 	register struct ifaddr *ifa;
250 
251 	for (ifp = ifnet.tqh_first; ifp != 0; ifp = ifp->if_list.tqe_next)
252 		for (ifa = ifp->if_addrlist.tqh_first; ifa != 0; ifa = ifa->ifa_list.tqe_next)
253 			if (ifa->ifa_addr->sa_family == af)
254 				return (ifa);
255 	return ((struct ifaddr *)0);
256 }
257 
258 /*
259  * Find an interface address specific to an interface best matching
260  * a given address.
261  */
262 struct ifaddr *
263 ifaof_ifpforaddr(addr, ifp)
264 	struct sockaddr *addr;
265 	register struct ifnet *ifp;
266 {
267 	register struct ifaddr *ifa;
268 	register char *cp, *cp2, *cp3;
269 	register char *cplim;
270 	struct ifaddr *ifa_maybe = 0;
271 	u_int af = addr->sa_family;
272 
273 	if (af >= AF_MAX)
274 		return (0);
275 	for (ifa = ifp->if_addrlist.tqh_first; ifa != 0; ifa = ifa->ifa_list.tqe_next) {
276 		if (ifa->ifa_addr->sa_family != af)
277 			continue;
278 		ifa_maybe = ifa;
279 		if (ifa->ifa_netmask == 0) {
280 			if (equal(addr, ifa->ifa_addr) ||
281 			    (ifa->ifa_dstaddr && equal(addr, ifa->ifa_dstaddr)))
282 				return (ifa);
283 			continue;
284 		}
285 		cp = addr->sa_data;
286 		cp2 = ifa->ifa_addr->sa_data;
287 		cp3 = ifa->ifa_netmask->sa_data;
288 		cplim = ifa->ifa_netmask->sa_len + (char *)ifa->ifa_netmask;
289 		for (; cp3 < cplim; cp3++)
290 			if ((*cp++ ^ *cp2++) & *cp3)
291 				break;
292 		if (cp3 == cplim)
293 			return (ifa);
294 	}
295 	return (ifa_maybe);
296 }
297 
298 #include <net/route.h>
299 
300 /*
301  * Default action when installing a route with a Link Level gateway.
302  * Lookup an appropriate real ifa to point to.
303  * This should be moved to /sys/net/link.c eventually.
304  */
305 void
306 link_rtrequest(cmd, rt, sa)
307 	int cmd;
308 	register struct rtentry *rt;
309 	struct sockaddr *sa;
310 {
311 	register struct ifaddr *ifa;
312 	struct sockaddr *dst;
313 	struct ifnet *ifp;
314 
315 	if (cmd != RTM_ADD || ((ifa = rt->rt_ifa) == 0) ||
316 	    ((ifp = ifa->ifa_ifp) == 0) || ((dst = rt_key(rt)) == 0))
317 		return;
318 	if ((ifa = ifaof_ifpforaddr(dst, ifp)) != NULL) {
319 		IFAFREE(rt->rt_ifa);
320 		rt->rt_ifa = ifa;
321 		ifa->ifa_refcnt++;
322 		if (ifa->ifa_rtrequest && ifa->ifa_rtrequest != link_rtrequest)
323 			ifa->ifa_rtrequest(cmd, rt, sa);
324 	}
325 }
326 
327 /*
328  * Mark an interface down and notify protocols of
329  * the transition.
330  * NOTE: must be called at splsoftnet or equivalent.
331  */
332 void
333 if_down(ifp)
334 	register struct ifnet *ifp;
335 {
336 	register struct ifaddr *ifa;
337 
338 	ifp->if_flags &= ~IFF_UP;
339 	for (ifa = ifp->if_addrlist.tqh_first; ifa != 0; ifa = ifa->ifa_list.tqe_next)
340 		pfctlinput(PRC_IFDOWN, ifa->ifa_addr);
341 	if_qflush(&ifp->if_snd);
342 	rt_ifmsg(ifp);
343 }
344 
345 /*
346  * Mark an interface up and notify protocols of
347  * the transition.
348  * NOTE: must be called at splsoftnet or equivalent.
349  */
350 void
351 if_up(ifp)
352 	register struct ifnet *ifp;
353 {
354 #ifdef notyet
355 	register struct ifaddr *ifa;
356 #endif
357 
358 	ifp->if_flags |= IFF_UP;
359 #ifdef notyet
360 	/* this has no effect on IP, and will kill all ISO connections XXX */
361 	for (ifa = ifp->if_addrlist.tqh_first; ifa != 0;
362 	     ifa = ifa->ifa_list.tqe_next)
363 		pfctlinput(PRC_IFUP, ifa->ifa_addr);
364 #endif
365 	rt_ifmsg(ifp);
366 }
367 
368 /*
369  * Flush an interface queue.
370  */
371 void
372 if_qflush(ifq)
373 	register struct ifqueue *ifq;
374 {
375 	register struct mbuf *m, *n;
376 
377 	n = ifq->ifq_head;
378 	while ((m = n) != NULL) {
379 		n = m->m_act;
380 		m_freem(m);
381 	}
382 	ifq->ifq_head = 0;
383 	ifq->ifq_tail = 0;
384 	ifq->ifq_len = 0;
385 }
386 
387 /*
388  * Handle interface watchdog timer routines.  Called
389  * from softclock, we decrement timers (if set) and
390  * call the appropriate interface routine on expiration.
391  */
392 void
393 if_slowtimo(arg)
394 	void *arg;
395 {
396 	register struct ifnet *ifp;
397 	int s = splimp();
398 
399 	for (ifp = ifnet.tqh_first; ifp != 0; ifp = ifp->if_list.tqe_next) {
400 		if (ifp->if_timer == 0 || --ifp->if_timer)
401 			continue;
402 		if (ifp->if_watchdog)
403 			(*ifp->if_watchdog)(ifp);
404 	}
405 	splx(s);
406 	timeout(if_slowtimo, NULL, hz / IFNET_SLOWHZ);
407 }
408 
409 /*
410  * Map interface name to
411  * interface structure pointer.
412  */
413 struct ifnet *
414 ifunit(name)
415 	register char *name;
416 {
417 	register struct ifnet *ifp;
418 
419 	for (ifp = ifnet.tqh_first; ifp != 0; ifp = ifp->if_list.tqe_next)
420 		if (strcmp(ifp->if_xname, name) == 0)
421 			return (ifp);
422 
423 	return (NULL);
424 }
425 
426 /*
427  * Interface ioctls.
428  */
429 int
430 ifioctl(so, cmd, data, p)
431 	struct socket *so;
432 	u_long cmd;
433 	caddr_t data;
434 	struct proc *p;
435 {
436 	register struct ifnet *ifp;
437 	register struct ifreq *ifr;
438 	int error;
439 
440 	switch (cmd) {
441 
442 	case SIOCGIFCONF:
443 	case OSIOCGIFCONF:
444 		return (ifconf(cmd, data));
445 	}
446 	ifr = (struct ifreq *)data;
447 	ifp = ifunit(ifr->ifr_name);
448 	if (ifp == 0)
449 		return (ENXIO);
450 	switch (cmd) {
451 
452 	case SIOCGIFFLAGS:
453 		ifr->ifr_flags = ifp->if_flags;
454 		break;
455 
456 	case SIOCGIFMETRIC:
457 		ifr->ifr_metric = ifp->if_metric;
458 		break;
459 
460 	case SIOCGIFMTU:
461 		ifr->ifr_mtu = ifp->if_mtu;
462 		break;
463 
464 	case SIOCSIFFLAGS:
465 		if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
466 			return (error);
467 		if (ifp->if_flags & IFF_UP && (ifr->ifr_flags & IFF_UP) == 0) {
468 			int s = splimp();
469 			if_down(ifp);
470 			splx(s);
471 		}
472 		if (ifr->ifr_flags & IFF_UP && (ifp->if_flags & IFF_UP) == 0) {
473 			int s = splimp();
474 			if_up(ifp);
475 			splx(s);
476 		}
477 		ifp->if_flags = (ifp->if_flags & IFF_CANTCHANGE) |
478 			(ifr->ifr_flags &~ IFF_CANTCHANGE);
479 		if (ifp->if_ioctl)
480 			(void) (*ifp->if_ioctl)(ifp, cmd, data);
481 		break;
482 
483 	case SIOCSIFMETRIC:
484 		if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
485 			return (error);
486 		ifp->if_metric = ifr->ifr_metric;
487 		break;
488 
489 	case SIOCSIFMTU:
490 	case SIOCADDMULTI:
491 	case SIOCDELMULTI:
492 	case SIOCSIFMEDIA:
493 		if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
494 			return (error);
495 		/* FALLTHROUGH */
496 	case SIOCGIFMEDIA:
497 		if (ifp->if_ioctl == 0)
498 			return (EOPNOTSUPP);
499 		return ((*ifp->if_ioctl)(ifp, cmd, data));
500 
501 	default:
502 		if (so->so_proto == 0)
503 			return (EOPNOTSUPP);
504 #if !defined(COMPAT_43) && !defined(COMPAT_LINUX) && !defined(COMPAT_SVR4)
505 		return ((*so->so_proto->pr_usrreq)(so, PRU_CONTROL,
506 		    (struct mbuf *)cmd, (struct mbuf *)data,
507 		    (struct mbuf *)ifp, p));
508 #else
509 	    {
510 		int ocmd = cmd;
511 
512 		switch (cmd) {
513 
514 		case SIOCSIFADDR:
515 		case SIOCSIFDSTADDR:
516 		case SIOCSIFBRDADDR:
517 		case SIOCSIFNETMASK:
518 #if BYTE_ORDER != BIG_ENDIAN
519 			if (ifr->ifr_addr.sa_family == 0 &&
520 			    ifr->ifr_addr.sa_len < 16) {
521 				ifr->ifr_addr.sa_family = ifr->ifr_addr.sa_len;
522 				ifr->ifr_addr.sa_len = 16;
523 			}
524 #else
525 			if (ifr->ifr_addr.sa_len == 0)
526 				ifr->ifr_addr.sa_len = 16;
527 #endif
528 			break;
529 
530 		case OSIOCGIFADDR:
531 			cmd = SIOCGIFADDR;
532 			break;
533 
534 		case OSIOCGIFDSTADDR:
535 			cmd = SIOCGIFDSTADDR;
536 			break;
537 
538 		case OSIOCGIFBRDADDR:
539 			cmd = SIOCGIFBRDADDR;
540 			break;
541 
542 		case OSIOCGIFNETMASK:
543 			cmd = SIOCGIFNETMASK;
544 		}
545 		error = ((*so->so_proto->pr_usrreq)(so, PRU_CONTROL,
546 		    (struct mbuf *)cmd, (struct mbuf *)data,
547 		    (struct mbuf *)ifp, p));
548 		switch (ocmd) {
549 
550 		case OSIOCGIFADDR:
551 		case OSIOCGIFDSTADDR:
552 		case OSIOCGIFBRDADDR:
553 		case OSIOCGIFNETMASK:
554 			*(u_int16_t *)&ifr->ifr_addr = ifr->ifr_addr.sa_family;
555 		}
556 		return (error);
557 
558 	    }
559 #endif
560 	}
561 	return (0);
562 }
563 
564 /*
565  * Return interface configuration
566  * of system.  List may be used
567  * in later ioctl's (above) to get
568  * other information.
569  */
570 /*ARGSUSED*/
571 int
572 ifconf(cmd, data)
573 	u_long cmd;
574 	caddr_t data;
575 {
576 	register struct ifconf *ifc = (struct ifconf *)data;
577 	register struct ifnet *ifp;
578 	register struct ifaddr *ifa;
579 	struct ifreq ifr, *ifrp;
580 	int space = ifc->ifc_len, error = 0;
581 
582 	ifrp = ifc->ifc_req;
583 	for (ifp = ifnet.tqh_first;
584 	    space >= sizeof (ifr) && ifp != 0; ifp = ifp->if_list.tqe_next) {
585 		bcopy(ifp->if_xname, ifr.ifr_name, IFNAMSIZ);
586 		if ((ifa = ifp->if_addrlist.tqh_first) == 0) {
587 			bzero((caddr_t)&ifr.ifr_addr, sizeof(ifr.ifr_addr));
588 			error = copyout((caddr_t)&ifr, (caddr_t)ifrp,
589 			    sizeof(ifr));
590 			if (error)
591 				break;
592 			space -= sizeof (ifr), ifrp++;
593 		} else
594 		    for (; space >= sizeof (ifr) && ifa != 0; ifa = ifa->ifa_list.tqe_next) {
595 			register struct sockaddr *sa = ifa->ifa_addr;
596 #if defined(COMPAT_43) || defined(COMPAT_LINUX) || defined(COMPAT_SVR4)
597 			if (cmd == OSIOCGIFCONF) {
598 				struct osockaddr *osa =
599 					 (struct osockaddr *)&ifr.ifr_addr;
600 				ifr.ifr_addr = *sa;
601 				osa->sa_family = sa->sa_family;
602 				error = copyout((caddr_t)&ifr, (caddr_t)ifrp,
603 						sizeof (ifr));
604 				ifrp++;
605 			} else
606 #endif
607 			if (sa->sa_len <= sizeof(*sa)) {
608 				ifr.ifr_addr = *sa;
609 				error = copyout((caddr_t)&ifr, (caddr_t)ifrp,
610 						sizeof (ifr));
611 				ifrp++;
612 			} else {
613 				space -= sa->sa_len - sizeof(*sa);
614 				if (space < sizeof (ifr))
615 					break;
616 				error = copyout((caddr_t)&ifr, (caddr_t)ifrp,
617 						sizeof (ifr.ifr_name));
618 				if (error == 0)
619 				    error = copyout((caddr_t)sa,
620 				      (caddr_t)&ifrp->ifr_addr, sa->sa_len);
621 				ifrp = (struct ifreq *)
622 					(sa->sa_len + (caddr_t)&ifrp->ifr_addr);
623 			}
624 			if (error)
625 				break;
626 			space -= sizeof (ifr);
627 		}
628 	}
629 	ifc->ifc_len -= space;
630 	return (error);
631 }
632