xref: /freebsd/sys/net/if.c (revision 0de89efe5c443f213c7ea28773ef2dc6cf3af2ed)
1 /*
2  * Copyright (c) 1980, 1986, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	@(#)if.c	8.3 (Berkeley) 1/4/94
34  *	$Id: if.c,v 1.52 1997/09/02 01:18:34 bde Exp $
35  */
36 
37 #include <sys/param.h>
38 #include <sys/queue.h>
39 #include <sys/malloc.h>
40 #include <sys/mbuf.h>
41 #include <sys/systm.h>
42 #include <sys/proc.h>
43 #include <sys/socket.h>
44 #include <sys/socketvar.h>
45 #include <sys/protosw.h>
46 #include <sys/kernel.h>
47 #include <sys/sockio.h>
48 #include <sys/errno.h>
49 #include <sys/syslog.h>
50 #include <sys/sysctl.h>
51 
52 #include <net/if.h>
53 #include <net/if_dl.h>
54 #include <net/if_types.h>
55 #include <net/radix.h>
56 
57 /*
58  * System initialization
59  */
60 
61 static int ifconf __P((int, caddr_t));
62 static void ifinit __P((void *));
63 static void if_qflush __P((struct ifqueue *));
64 static void if_slowtimo __P((void *));
65 static void link_rtrequest __P((int, struct rtentry *, struct sockaddr *));
66 
67 SYSINIT(interfaces, SI_SUB_PROTO_IF, SI_ORDER_FIRST, ifinit, NULL)
68 
69 
70 int	ifqmaxlen = IFQ_MAXLEN;
71 struct	ifnethead ifnet;	/* depend on static init XXX */
72 
73 /*
74  * Network interface utility routines.
75  *
76  * Routines with ifa_ifwith* names take sockaddr *'s as
77  * parameters.
78  *
79  * This routine assumes that it will be called at splimp() or higher.
80  */
81 /* ARGSUSED*/
82 void
83 ifinit(dummy)
84 	void *dummy;
85 {
86 	register struct ifnet *ifp;
87 
88 	for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_link.tqe_next)
89 		if (ifp->if_snd.ifq_maxlen == 0)
90 			ifp->if_snd.ifq_maxlen = ifqmaxlen;
91 	if_slowtimo(0);
92 }
93 
94 int if_index = 0;
95 struct ifaddr **ifnet_addrs;
96 
97 
98 /*
99  * Attach an interface to the
100  * list of "active" interfaces.
101  */
102 void
103 if_attach(ifp)
104 	struct ifnet *ifp;
105 {
106 	unsigned socksize, ifasize;
107 	int namelen, masklen;
108 	char workbuf[64];
109 	register struct sockaddr_dl *sdl;
110 	register struct ifaddr *ifa;
111 	static int if_indexlim = 8;
112 	static int inited;
113 
114 	if (!inited) {
115 		TAILQ_INIT(&ifnet);
116 		inited = 1;
117 	}
118 
119 	TAILQ_INSERT_TAIL(&ifnet, ifp, if_link);
120 	ifp->if_index = ++if_index;
121 	/*
122 	 * XXX -
123 	 * The old code would work if the interface passed a pre-existing
124 	 * chain of ifaddrs to this code.  We don't trust our callers to
125 	 * properly initialize the tailq, however, so we no longer allow
126 	 * this unlikely case.
127 	 */
128 	TAILQ_INIT(&ifp->if_addrhead);
129 	LIST_INIT(&ifp->if_multiaddrs);
130 	microtime(&ifp->if_lastchange);
131 	if (ifnet_addrs == 0 || if_index >= if_indexlim) {
132 		unsigned n = (if_indexlim <<= 1) * sizeof(ifa);
133 		struct ifaddr **q = (struct ifaddr **)
134 					malloc(n, M_IFADDR, M_WAITOK);
135 		bzero((caddr_t)q, n);
136 		if (ifnet_addrs) {
137 			bcopy((caddr_t)ifnet_addrs, (caddr_t)q, n/2);
138 			free((caddr_t)ifnet_addrs, M_IFADDR);
139 		}
140 		ifnet_addrs = q;
141 	}
142 	/*
143 	 * create a Link Level name for this device
144 	 */
145 	namelen = sprintf(workbuf, "%s%d", ifp->if_name, ifp->if_unit);
146 #define _offsetof(t, m) ((int)((caddr_t)&((t *)0)->m))
147 	masklen = _offsetof(struct sockaddr_dl, sdl_data[0]) + namelen;
148 	socksize = masklen + ifp->if_addrlen;
149 #define ROUNDUP(a) (1 + (((a) - 1) | (sizeof(long) - 1)))
150 	socksize = ROUNDUP(socksize);
151 	if (socksize < sizeof(*sdl))
152 		socksize = sizeof(*sdl);
153 	ifasize = sizeof(*ifa) + 2 * socksize;
154 	ifa = (struct ifaddr *)malloc(ifasize, M_IFADDR, M_WAITOK);
155 	if (ifa) {
156 		bzero((caddr_t)ifa, ifasize);
157 		sdl = (struct sockaddr_dl *)(ifa + 1);
158 		sdl->sdl_len = socksize;
159 		sdl->sdl_family = AF_LINK;
160 		bcopy(workbuf, sdl->sdl_data, namelen);
161 		sdl->sdl_nlen = namelen;
162 		sdl->sdl_index = ifp->if_index;
163 		sdl->sdl_type = ifp->if_type;
164 		ifnet_addrs[if_index - 1] = ifa;
165 		ifa->ifa_ifp = ifp;
166 		ifa->ifa_rtrequest = link_rtrequest;
167 		ifa->ifa_addr = (struct sockaddr *)sdl;
168 		sdl = (struct sockaddr_dl *)(socksize + (caddr_t)sdl);
169 		ifa->ifa_netmask = (struct sockaddr *)sdl;
170 		sdl->sdl_len = masklen;
171 		while (namelen != 0)
172 			sdl->sdl_data[--namelen] = 0xff;
173 		TAILQ_INSERT_HEAD(&ifp->if_addrhead, ifa, ifa_link);
174 	}
175 }
176 /*
177  * Locate an interface based on a complete address.
178  */
179 /*ARGSUSED*/
180 struct ifaddr *
181 ifa_ifwithaddr(addr)
182 	register struct sockaddr *addr;
183 {
184 	register struct ifnet *ifp;
185 	register struct ifaddr *ifa;
186 
187 #define	equal(a1, a2) \
188   (bcmp((caddr_t)(a1), (caddr_t)(a2), ((struct sockaddr *)(a1))->sa_len) == 0)
189 	for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_link.tqe_next)
190 	    for (ifa = ifp->if_addrhead.tqh_first; ifa;
191 		 ifa = ifa->ifa_link.tqe_next) {
192 		if (ifa->ifa_addr->sa_family != addr->sa_family)
193 			continue;
194 		if (equal(addr, ifa->ifa_addr))
195 			return (ifa);
196 		if ((ifp->if_flags & IFF_BROADCAST) && ifa->ifa_broadaddr &&
197 		    equal(ifa->ifa_broadaddr, addr))
198 			return (ifa);
199 	}
200 	return ((struct ifaddr *)0);
201 }
202 /*
203  * Locate the point to point interface with a given destination address.
204  */
205 /*ARGSUSED*/
206 struct ifaddr *
207 ifa_ifwithdstaddr(addr)
208 	register struct sockaddr *addr;
209 {
210 	register struct ifnet *ifp;
211 	register struct ifaddr *ifa;
212 
213 	for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_link.tqe_next)
214 	    if (ifp->if_flags & IFF_POINTOPOINT)
215 		for (ifa = ifp->if_addrhead.tqh_first; ifa;
216 		     ifa = ifa->ifa_link.tqe_next) {
217 			if (ifa->ifa_addr->sa_family != addr->sa_family)
218 				continue;
219 			if (ifa->ifa_dstaddr && equal(addr, ifa->ifa_dstaddr))
220 				return (ifa);
221 	}
222 	return ((struct ifaddr *)0);
223 }
224 
225 /*
226  * Find an interface on a specific network.  If many, choice
227  * is most specific found.
228  */
229 struct ifaddr *
230 ifa_ifwithnet(addr)
231 	struct sockaddr *addr;
232 {
233 	register struct ifnet *ifp;
234 	register struct ifaddr *ifa;
235 	struct ifaddr *ifa_maybe = (struct ifaddr *) 0;
236 	u_int af = addr->sa_family;
237 	char *addr_data = addr->sa_data, *cplim;
238 
239 	/*
240 	 * AF_LINK addresses can be looked up directly by their index number,
241 	 * so do that if we can.
242 	 */
243 	if (af == AF_LINK) {
244 	    register struct sockaddr_dl *sdl = (struct sockaddr_dl *)addr;
245 	    if (sdl->sdl_index && sdl->sdl_index <= if_index)
246 		return (ifnet_addrs[sdl->sdl_index - 1]);
247 	}
248 
249 	/*
250 	 * Scan though each interface, looking for ones that have
251 	 * addresses in this address family.
252 	 */
253 	for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_link.tqe_next) {
254 		for (ifa = ifp->if_addrhead.tqh_first; ifa;
255 		     ifa = ifa->ifa_link.tqe_next) {
256 			register char *cp, *cp2, *cp3;
257 
258 			if (ifa->ifa_addr->sa_family != af)
259 next:				continue;
260 			if (ifp->if_flags & IFF_POINTOPOINT) {
261 				/*
262 				 * This is a bit broken as it doesn't
263 				 * take into account that the remote end may
264 				 * be a single node in the network we are
265 				 * looking for.
266 				 * The trouble is that we don't know the
267 				 * netmask for the remote end.
268 				 */
269 				if (ifa->ifa_dstaddr != 0
270 				    && equal(addr, ifa->ifa_dstaddr))
271  					return (ifa);
272 			} else {
273 				/*
274 				 * if we have a special address handler,
275 				 * then use it instead of the generic one.
276 				 */
277 	          		if (ifa->ifa_claim_addr) {
278 					if ((*ifa->ifa_claim_addr)(ifa, addr)) {
279 						return (ifa);
280 					} else {
281 						continue;
282 					}
283 				}
284 
285 				/*
286 				 * Scan all the bits in the ifa's address.
287 				 * If a bit dissagrees with what we are
288 				 * looking for, mask it with the netmask
289 				 * to see if it really matters.
290 				 * (A byte at a time)
291 				 */
292 				if (ifa->ifa_netmask == 0)
293 					continue;
294 				cp = addr_data;
295 				cp2 = ifa->ifa_addr->sa_data;
296 				cp3 = ifa->ifa_netmask->sa_data;
297 				cplim = ifa->ifa_netmask->sa_len
298 					+ (char *)ifa->ifa_netmask;
299 				while (cp3 < cplim)
300 					if ((*cp++ ^ *cp2++) & *cp3++)
301 						goto next; /* next address! */
302 				/*
303 				 * If the netmask of what we just found
304 				 * is more specific than what we had before
305 				 * (if we had one) then remember the new one
306 				 * before continuing to search
307 				 * for an even better one.
308 				 */
309 				if (ifa_maybe == 0 ||
310 				    rn_refines((caddr_t)ifa->ifa_netmask,
311 				    (caddr_t)ifa_maybe->ifa_netmask))
312 					ifa_maybe = ifa;
313 			}
314 		}
315 	}
316 	return (ifa_maybe);
317 }
318 
319 /*
320  * Find an interface address specific to an interface best matching
321  * a given address.
322  */
323 struct ifaddr *
324 ifaof_ifpforaddr(addr, ifp)
325 	struct sockaddr *addr;
326 	register struct ifnet *ifp;
327 {
328 	register struct ifaddr *ifa;
329 	register char *cp, *cp2, *cp3;
330 	register char *cplim;
331 	struct ifaddr *ifa_maybe = 0;
332 	u_int af = addr->sa_family;
333 
334 	if (af >= AF_MAX)
335 		return (0);
336 	for (ifa = ifp->if_addrhead.tqh_first; ifa;
337 	     ifa = ifa->ifa_link.tqe_next) {
338 		if (ifa->ifa_addr->sa_family != af)
339 			continue;
340 		if (ifa_maybe == 0)
341 			ifa_maybe = ifa;
342 		if (ifa->ifa_netmask == 0) {
343 			if (equal(addr, ifa->ifa_addr) ||
344 			    (ifa->ifa_dstaddr && equal(addr, ifa->ifa_dstaddr)))
345 				return (ifa);
346 			continue;
347 		}
348 		if (ifp->if_flags & IFF_POINTOPOINT) {
349 			if (equal(addr, ifa->ifa_dstaddr))
350 				return (ifa);
351 		} else {
352 			cp = addr->sa_data;
353 			cp2 = ifa->ifa_addr->sa_data;
354 			cp3 = ifa->ifa_netmask->sa_data;
355 			cplim = ifa->ifa_netmask->sa_len + (char *)ifa->ifa_netmask;
356 			for (; cp3 < cplim; cp3++)
357 				if ((*cp++ ^ *cp2++) & *cp3)
358 					break;
359 			if (cp3 == cplim)
360 				return (ifa);
361 		}
362 	}
363 	return (ifa_maybe);
364 }
365 
366 #include <net/route.h>
367 
368 /*
369  * Default action when installing a route with a Link Level gateway.
370  * Lookup an appropriate real ifa to point to.
371  * This should be moved to /sys/net/link.c eventually.
372  */
373 static void
374 link_rtrequest(cmd, rt, sa)
375 	int cmd;
376 	register struct rtentry *rt;
377 	struct sockaddr *sa;
378 {
379 	register struct ifaddr *ifa;
380 	struct sockaddr *dst;
381 	struct ifnet *ifp;
382 
383 	if (cmd != RTM_ADD || ((ifa = rt->rt_ifa) == 0) ||
384 	    ((ifp = ifa->ifa_ifp) == 0) || ((dst = rt_key(rt)) == 0))
385 		return;
386 	ifa = ifaof_ifpforaddr(dst, ifp);
387 	if (ifa) {
388 		IFAFREE(rt->rt_ifa);
389 		rt->rt_ifa = ifa;
390 		ifa->ifa_refcnt++;
391 		if (ifa->ifa_rtrequest && ifa->ifa_rtrequest != link_rtrequest)
392 			ifa->ifa_rtrequest(cmd, rt, sa);
393 	}
394 }
395 
396 /*
397  * Mark an interface down and notify protocols of
398  * the transition.
399  * NOTE: must be called at splnet or eqivalent.
400  */
401 void
402 if_down(ifp)
403 	register struct ifnet *ifp;
404 {
405 	register struct ifaddr *ifa;
406 
407 	ifp->if_flags &= ~IFF_UP;
408 	microtime(&ifp->if_lastchange);
409 	for (ifa = ifp->if_addrhead.tqh_first; ifa;
410 	     ifa = ifa->ifa_link.tqe_next)
411 		pfctlinput(PRC_IFDOWN, ifa->ifa_addr);
412 	if_qflush(&ifp->if_snd);
413 	rt_ifmsg(ifp);
414 }
415 
416 /*
417  * Mark an interface up and notify protocols of
418  * the transition.
419  * NOTE: must be called at splnet or eqivalent.
420  */
421 void
422 if_up(ifp)
423 	register struct ifnet *ifp;
424 {
425 	register struct ifaddr *ifa;
426 
427 	ifp->if_flags |= IFF_UP;
428 	microtime(&ifp->if_lastchange);
429 	for (ifa = ifp->if_addrhead.tqh_first; ifa;
430 	     ifa = ifa->ifa_link.tqe_next)
431 		pfctlinput(PRC_IFUP, ifa->ifa_addr);
432 	rt_ifmsg(ifp);
433 }
434 
435 /*
436  * Flush an interface queue.
437  */
438 static void
439 if_qflush(ifq)
440 	register struct ifqueue *ifq;
441 {
442 	register struct mbuf *m, *n;
443 
444 	n = ifq->ifq_head;
445 	while ((m = n) != 0) {
446 		n = m->m_act;
447 		m_freem(m);
448 	}
449 	ifq->ifq_head = 0;
450 	ifq->ifq_tail = 0;
451 	ifq->ifq_len = 0;
452 }
453 
454 /*
455  * Handle interface watchdog timer routines.  Called
456  * from softclock, we decrement timers (if set) and
457  * call the appropriate interface routine on expiration.
458  */
459 static void
460 if_slowtimo(arg)
461 	void *arg;
462 {
463 	register struct ifnet *ifp;
464 	int s = splimp();
465 
466 	for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_link.tqe_next) {
467 		if (ifp->if_timer == 0 || --ifp->if_timer)
468 			continue;
469 		if (ifp->if_watchdog)
470 			(*ifp->if_watchdog)(ifp);
471 	}
472 	splx(s);
473 	timeout(if_slowtimo, (void *)0, hz / IFNET_SLOWHZ);
474 }
475 
476 /*
477  * Map interface name to
478  * interface structure pointer.
479  */
480 struct ifnet *
481 ifunit(name)
482 	register char *name;
483 {
484 	register char *cp;
485 	register struct ifnet *ifp;
486 	int unit;
487 	unsigned len;
488 	char *ep, c;
489 
490 	for (cp = name; cp < name + IFNAMSIZ && *cp; cp++)
491 		if (*cp >= '0' && *cp <= '9')
492 			break;
493 	if (*cp == '\0' || cp == name + IFNAMSIZ)
494 		return ((struct ifnet *)0);
495 	/*
496 	 * Save first char of unit, and pointer to it,
497 	 * so we can put a null there to avoid matching
498 	 * initial substrings of interface names.
499 	 */
500 	len = cp - name + 1;
501 	c = *cp;
502 	ep = cp;
503 	for (unit = 0; *cp >= '0' && *cp <= '9'; )
504 		unit = unit * 10 + *cp++ - '0';
505 	if (*cp != '\0')
506 		return 0;	/* no trailing garbage allowed */
507 	*ep = 0;
508 	for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_link.tqe_next) {
509 		if (bcmp(ifp->if_name, name, len))
510 			continue;
511 		if (unit == ifp->if_unit)
512 			break;
513 	}
514 	*ep = c;
515 	return (ifp);
516 }
517 
518 /*
519  * Interface ioctls.
520  */
521 int
522 ifioctl(so, cmd, data, p)
523 	struct socket *so;
524 	int cmd;
525 	caddr_t data;
526 	struct proc *p;
527 {
528 	register struct ifnet *ifp;
529 	register struct ifreq *ifr;
530 	int error;
531 
532 	switch (cmd) {
533 
534 	case SIOCGIFCONF:
535 	case OSIOCGIFCONF:
536 		return (ifconf(cmd, data));
537 	}
538 	ifr = (struct ifreq *)data;
539 	ifp = ifunit(ifr->ifr_name);
540 	if (ifp == 0)
541 		return (ENXIO);
542 	switch (cmd) {
543 
544 	case SIOCGIFFLAGS:
545 		ifr->ifr_flags = ifp->if_flags;
546 		break;
547 
548 	case SIOCGIFMETRIC:
549 		ifr->ifr_metric = ifp->if_metric;
550 		break;
551 
552 	case SIOCGIFMTU:
553 		ifr->ifr_mtu = ifp->if_mtu;
554 		break;
555 
556 	case SIOCGIFPHYS:
557 		ifr->ifr_phys = ifp->if_physical;
558 		break;
559 
560 	case SIOCSIFFLAGS:
561 		error = suser(p->p_ucred, &p->p_acflag);
562 		if (error)
563 			return (error);
564 		if (ifp->if_flags & IFF_UP && (ifr->ifr_flags & IFF_UP) == 0) {
565 			int s = splimp();
566 			if_down(ifp);
567 			splx(s);
568 		}
569 		if (ifr->ifr_flags & IFF_UP && (ifp->if_flags & IFF_UP) == 0) {
570 			int s = splimp();
571 			if_up(ifp);
572 			splx(s);
573 		}
574 		ifp->if_flags = (ifp->if_flags & IFF_CANTCHANGE) |
575 			(ifr->ifr_flags &~ IFF_CANTCHANGE);
576 		if (ifp->if_ioctl)
577 			(void) (*ifp->if_ioctl)(ifp, cmd, data);
578 		microtime(&ifp->if_lastchange);
579 		break;
580 
581 	case SIOCSIFMETRIC:
582 		error = suser(p->p_ucred, &p->p_acflag);
583 		if (error)
584 			return (error);
585 		ifp->if_metric = ifr->ifr_metric;
586 		microtime(&ifp->if_lastchange);
587 		break;
588 
589 	case SIOCSIFPHYS:
590 		error = suser(p->p_ucred, &p->p_acflag);
591 		if (error)
592 			return error;
593 		if (!ifp->if_ioctl)
594 		        return EOPNOTSUPP;
595 		error = (*ifp->if_ioctl)(ifp, cmd, data);
596 		if (error == 0)
597 			microtime(&ifp->if_lastchange);
598 		return(error);
599 
600 	case SIOCSIFMTU:
601 		error = suser(p->p_ucred, &p->p_acflag);
602 		if (error)
603 			return (error);
604 		if (ifp->if_ioctl == NULL)
605 			return (EOPNOTSUPP);
606 		/*
607 		 * 72 was chosen below because it is the size of a TCP/IP
608 		 * header (40) + the minimum mss (32).
609 		 */
610 		if (ifr->ifr_mtu < 72 || ifr->ifr_mtu > 65535)
611 			return (EINVAL);
612 		error = (*ifp->if_ioctl)(ifp, cmd, data);
613 		if (error == 0)
614 			microtime(&ifp->if_lastchange);
615 		return(error);
616 
617 	case SIOCADDMULTI:
618 	case SIOCDELMULTI:
619 		error = suser(p->p_ucred, &p->p_acflag);
620 		if (error)
621 			return (error);
622 
623 		/* Don't allow group membership on non-multicast interfaces. */
624 		if ((ifp->if_flags & IFF_MULTICAST) == 0)
625 			return EOPNOTSUPP;
626 
627 		/* Don't let users screw up protocols' entries. */
628 		if (ifr->ifr_addr.sa_family != AF_LINK)
629 			return EINVAL;
630 
631 		if (cmd == SIOCADDMULTI) {
632 			struct ifmultiaddr *ifma;
633 			error = if_addmulti(ifp, &ifr->ifr_addr, &ifma);
634 		} else {
635 			error = if_delmulti(ifp, &ifr->ifr_addr);
636 		}
637 		if (error == 0)
638 			microtime(&ifp->if_lastchange);
639 		return error;
640 
641         case SIOCSIFMEDIA:
642 		error = suser(p->p_ucred, &p->p_acflag);
643 		if (error)
644 			return (error);
645 		if (ifp->if_ioctl == 0)
646 			return (EOPNOTSUPP);
647 		error = (*ifp->if_ioctl)(ifp, cmd, data);
648 		if (error == 0)
649 			microtime(&ifp->if_lastchange);
650 		return error;
651 
652 	case SIOCGIFMEDIA:
653 		if (ifp->if_ioctl == 0)
654 			return (EOPNOTSUPP);
655 		return ((*ifp->if_ioctl)(ifp, cmd, data));
656 
657 	default:
658 		if (so->so_proto == 0)
659 			return (EOPNOTSUPP);
660 #ifndef COMPAT_43
661 		return ((*so->so_proto->pr_usrreqs->pru_control)(so, cmd,
662 								 data,
663 								 ifp, p));
664 #else
665 	    {
666 		int ocmd = cmd;
667 
668 		switch (cmd) {
669 
670 		case SIOCSIFDSTADDR:
671 		case SIOCSIFADDR:
672 		case SIOCSIFBRDADDR:
673 		case SIOCSIFNETMASK:
674 #if BYTE_ORDER != BIG_ENDIAN
675 			if (ifr->ifr_addr.sa_family == 0 &&
676 			    ifr->ifr_addr.sa_len < 16) {
677 				ifr->ifr_addr.sa_family = ifr->ifr_addr.sa_len;
678 				ifr->ifr_addr.sa_len = 16;
679 			}
680 #else
681 			if (ifr->ifr_addr.sa_len == 0)
682 				ifr->ifr_addr.sa_len = 16;
683 #endif
684 			break;
685 
686 		case OSIOCGIFADDR:
687 			cmd = SIOCGIFADDR;
688 			break;
689 
690 		case OSIOCGIFDSTADDR:
691 			cmd = SIOCGIFDSTADDR;
692 			break;
693 
694 		case OSIOCGIFBRDADDR:
695 			cmd = SIOCGIFBRDADDR;
696 			break;
697 
698 		case OSIOCGIFNETMASK:
699 			cmd = SIOCGIFNETMASK;
700 		}
701 		error =  ((*so->so_proto->pr_usrreqs->pru_control)(so,
702 								   cmd,
703 								   data,
704 								   ifp, p));
705 		switch (ocmd) {
706 
707 		case OSIOCGIFADDR:
708 		case OSIOCGIFDSTADDR:
709 		case OSIOCGIFBRDADDR:
710 		case OSIOCGIFNETMASK:
711 			*(u_short *)&ifr->ifr_addr = ifr->ifr_addr.sa_family;
712 		}
713 		return (error);
714 
715 	    }
716 #endif
717 	}
718 	return (0);
719 }
720 
721 /*
722  * Set/clear promiscuous mode on interface ifp based on the truth value
723  * of pswitch.  The calls are reference counted so that only the first
724  * "on" request actually has an effect, as does the final "off" request.
725  * Results are undefined if the "off" and "on" requests are not matched.
726  */
727 int
728 ifpromisc(ifp, pswitch)
729 	struct ifnet *ifp;
730 	int pswitch;
731 {
732 	struct ifreq ifr;
733 	int error;
734 
735 	if (pswitch) {
736 		/*
737 		 * If the device is not configured up, we cannot put it in
738 		 * promiscuous mode.
739 		 */
740 		if ((ifp->if_flags & IFF_UP) == 0)
741 			return (ENETDOWN);
742 		if (ifp->if_pcount++ != 0)
743 			return (0);
744 		ifp->if_flags |= IFF_PROMISC;
745 		log(LOG_INFO, "%s%d: promiscuous mode enabled\n",
746 		    ifp->if_name, ifp->if_unit);
747 	} else {
748 		if (--ifp->if_pcount > 0)
749 			return (0);
750 		ifp->if_flags &= ~IFF_PROMISC;
751 	}
752 	ifr.ifr_flags = ifp->if_flags;
753 	error = (*ifp->if_ioctl)(ifp, SIOCSIFFLAGS, (caddr_t)&ifr);
754 	if (error == 0)
755 		rt_ifmsg(ifp);
756 	return error;
757 }
758 
759 /*
760  * Return interface configuration
761  * of system.  List may be used
762  * in later ioctl's (above) to get
763  * other information.
764  */
765 /*ARGSUSED*/
766 static int
767 ifconf(cmd, data)
768 	int cmd;
769 	caddr_t data;
770 {
771 	register struct ifconf *ifc = (struct ifconf *)data;
772 	register struct ifnet *ifp = ifnet.tqh_first;
773 	register struct ifaddr *ifa;
774 	struct ifreq ifr, *ifrp;
775 	int space = ifc->ifc_len, error = 0;
776 
777 	ifrp = ifc->ifc_req;
778 	for (; space > sizeof (ifr) && ifp; ifp = ifp->if_link.tqe_next) {
779 		char workbuf[64];
780 		int ifnlen;
781 
782 		ifnlen = sprintf(workbuf, "%s%d", ifp->if_name, ifp->if_unit);
783 		if(ifnlen + 1 > sizeof ifr.ifr_name) {
784 			error = ENAMETOOLONG;
785 		} else {
786 			strcpy(ifr.ifr_name, workbuf);
787 		}
788 
789 		if ((ifa = ifp->if_addrhead.tqh_first) == 0) {
790 			bzero((caddr_t)&ifr.ifr_addr, sizeof(ifr.ifr_addr));
791 			error = copyout((caddr_t)&ifr, (caddr_t)ifrp,
792 			    sizeof (ifr));
793 			if (error)
794 				break;
795 			space -= sizeof (ifr), ifrp++;
796 		} else
797 		    for ( ; space > sizeof (ifr) && ifa;
798 			 ifa = ifa->ifa_link.tqe_next) {
799 			register struct sockaddr *sa = ifa->ifa_addr;
800 #ifdef COMPAT_43
801 			if (cmd == OSIOCGIFCONF) {
802 				struct osockaddr *osa =
803 					 (struct osockaddr *)&ifr.ifr_addr;
804 				ifr.ifr_addr = *sa;
805 				osa->sa_family = sa->sa_family;
806 				error = copyout((caddr_t)&ifr, (caddr_t)ifrp,
807 						sizeof (ifr));
808 				ifrp++;
809 			} else
810 #endif
811 			if (sa->sa_len <= sizeof(*sa)) {
812 				ifr.ifr_addr = *sa;
813 				error = copyout((caddr_t)&ifr, (caddr_t)ifrp,
814 						sizeof (ifr));
815 				ifrp++;
816 			} else {
817 				space -= sa->sa_len - sizeof(*sa);
818 				if (space < sizeof (ifr))
819 					break;
820 				error = copyout((caddr_t)&ifr, (caddr_t)ifrp,
821 						sizeof (ifr.ifr_name));
822 				if (error == 0)
823 				    error = copyout((caddr_t)sa,
824 				      (caddr_t)&ifrp->ifr_addr, sa->sa_len);
825 				ifrp = (struct ifreq *)
826 					(sa->sa_len + (caddr_t)&ifrp->ifr_addr);
827 			}
828 			if (error)
829 				break;
830 			space -= sizeof (ifr);
831 		}
832 	}
833 	ifc->ifc_len -= space;
834 	return (error);
835 }
836 
837 /*
838  * Just like if_promisc(), but for all-multicast-reception mode.
839  */
840 int
841 if_allmulti(ifp, onswitch)
842 	struct ifnet *ifp;
843 	int onswitch;
844 {
845 	int error = 0;
846 	int s = splimp();
847 
848 	if (onswitch) {
849 		if (ifp->if_amcount++ == 0) {
850 			ifp->if_flags |= IFF_ALLMULTI;
851 			error = ifp->if_ioctl(ifp, SIOCSIFFLAGS, 0);
852 		}
853 	} else {
854 		if (ifp->if_amcount > 1) {
855 			ifp->if_amcount--;
856 		} else {
857 			ifp->if_amcount = 0;
858 			ifp->if_flags &= ~IFF_ALLMULTI;
859 			error = ifp->if_ioctl(ifp, SIOCSIFFLAGS, 0);
860 		}
861 	}
862 	splx(s);
863 
864 	if (error == 0)
865 		rt_ifmsg(ifp);
866 	return error;
867 }
868 
869 /*
870  * Add a multicast listenership to the interface in question.
871  * The link layer provides a routine which converts
872  */
873 int
874 if_addmulti(ifp, sa, retifma)
875 	struct ifnet *ifp;	/* interface to manipulate */
876 	struct sockaddr *sa;	/* address to add */
877 	struct ifmultiaddr **retifma;
878 {
879 	struct sockaddr *llsa, *dupsa;
880 	int error, s;
881 	struct ifmultiaddr *ifma;
882 
883 	/*
884 	 * If the matching multicast address already exists
885 	 * then don't add a new one, just add a reference
886 	 */
887 	for (ifma = ifp->if_multiaddrs.lh_first; ifma;
888 	     ifma = ifma->ifma_link.le_next) {
889 		if (equal(sa, ifma->ifma_addr)) {
890 			ifma->ifma_refcount++;
891 			if (retifma)
892 				*retifma = ifma;
893 			return 0;
894 		}
895 	}
896 
897 	/*
898 	 * Give the link layer a chance to accept/reject it, and also
899 	 * find out which AF_LINK address this maps to, if it isn't one
900 	 * already.
901 	 */
902 	if (ifp->if_resolvemulti) {
903 		error = ifp->if_resolvemulti(ifp, &llsa, sa);
904 		if (error) return error;
905 	} else {
906 		llsa = 0;
907 	}
908 
909 	MALLOC(ifma, struct ifmultiaddr *, sizeof *ifma, M_IFMADDR, M_WAITOK);
910 	MALLOC(dupsa, struct sockaddr *, sa->sa_len, M_IFMADDR, M_WAITOK);
911 	bcopy(sa, dupsa, sa->sa_len);
912 
913 	ifma->ifma_addr = dupsa;
914 	ifma->ifma_lladdr = llsa;
915 	ifma->ifma_ifp = ifp;
916 	ifma->ifma_refcount = 1;
917 	ifma->ifma_protospec = 0;
918 	rt_newmaddrmsg(RTM_NEWMADDR, ifma);
919 
920 	/*
921 	 * Some network interfaces can scan the address list at
922 	 * interrupt time; lock them out.
923 	 */
924 	s = splimp();
925 	LIST_INSERT_HEAD(&ifp->if_multiaddrs, ifma, ifma_link);
926 	splx(s);
927 	*retifma = ifma;
928 
929 	if (llsa != 0) {
930 		for (ifma = ifp->if_multiaddrs.lh_first; ifma;
931 		     ifma = ifma->ifma_link.le_next) {
932 			if (equal(ifma->ifma_addr, llsa))
933 				break;
934 		}
935 		if (ifma) {
936 			ifma->ifma_refcount++;
937 		} else {
938 			MALLOC(ifma, struct ifmultiaddr *, sizeof *ifma,
939 			       M_IFMADDR, M_WAITOK);
940 			MALLOC(dupsa, struct sockaddr *, llsa->sa_len,
941 			       M_IFMADDR, M_WAITOK);
942 			bcopy(llsa, dupsa, llsa->sa_len);
943 			ifma->ifma_addr = dupsa;
944 			ifma->ifma_ifp = ifp;
945 			ifma->ifma_refcount = 1;
946 			s = splimp();
947 			LIST_INSERT_HEAD(&ifp->if_multiaddrs, ifma, ifma_link);
948 			splx(s);
949 		}
950 	}
951 	/*
952 	 * We are certain we have added something, so call down to the
953 	 * interface to let them know about it.
954 	 */
955 	s = splimp();
956 	ifp->if_ioctl(ifp, SIOCADDMULTI, 0);
957 	splx(s);
958 
959 	return 0;
960 }
961 
962 /*
963  * Remove a reference to a multicast address on this interface.  Yell
964  * if the request does not match an existing membership.
965  */
966 int
967 if_delmulti(ifp, sa)
968 	struct ifnet *ifp;
969 	struct sockaddr *sa;
970 {
971 	struct ifmultiaddr *ifma;
972 	int s;
973 
974 	for (ifma = ifp->if_multiaddrs.lh_first; ifma;
975 	     ifma = ifma->ifma_link.le_next)
976 		if (equal(sa, ifma->ifma_addr))
977 			break;
978 	if (ifma == 0)
979 		return ENOENT;
980 
981 	if (ifma->ifma_refcount > 1) {
982 		ifma->ifma_refcount--;
983 		return 0;
984 	}
985 
986 	rt_newmaddrmsg(RTM_DELMADDR, ifma);
987 	sa = ifma->ifma_lladdr;
988 	s = splimp();
989 	LIST_REMOVE(ifma, ifma_link);
990 	splx(s);
991 	free(ifma->ifma_addr, M_IFMADDR);
992 	free(ifma, M_IFMADDR);
993 	if (sa == 0)
994 		return 0;
995 
996 	/*
997 	 * Now look for the link-layer address which corresponds to
998 	 * this network address.  It had been squirreled away in
999 	 * ifma->ifma_lladdr for this purpose (so we don't have
1000 	 * to call ifp->if_resolvemulti() again), and we saved that
1001 	 * value in sa above.  If some nasty deleted the
1002 	 * link-layer address out from underneath us, we can deal because
1003 	 * the address we stored was is not the same as the one which was
1004 	 * in the record for the link-layer address.  (So we don't complain
1005 	 * in that case.)
1006 	 */
1007 	for (ifma = ifp->if_multiaddrs.lh_first; ifma;
1008 	     ifma = ifma->ifma_link.le_next)
1009 		if (equal(sa, ifma->ifma_addr))
1010 			break;
1011 	if (ifma == 0)
1012 		return 0;
1013 
1014 	if (ifma->ifma_refcount > 1) {
1015 		ifma->ifma_refcount--;
1016 		return 0;
1017 	}
1018 
1019 	s = splimp();
1020 	LIST_REMOVE(ifma, ifma_link);
1021 	splx(s);
1022 	free(ifma->ifma_addr, M_IFMADDR);
1023 	free(sa, M_IFMADDR);
1024 	free(ifma, M_IFMADDR);
1025 
1026 	return 0;
1027 }
1028 
1029 struct ifmultiaddr *
1030 ifmaof_ifpforaddr(sa, ifp)
1031 	struct sockaddr *sa;
1032 	struct ifnet *ifp;
1033 {
1034 	struct ifmultiaddr *ifma;
1035 
1036 	for (ifma = ifp->if_multiaddrs.lh_first; ifma;
1037 	     ifma = ifma->ifma_link.le_next)
1038 		if (equal(ifma->ifma_addr, sa))
1039 			break;
1040 
1041 	return ifma;
1042 }
1043 
1044 SYSCTL_NODE(_net, PF_LINK, link, CTLFLAG_RW, 0, "Link layers");
1045 SYSCTL_NODE(_net_link, 0, generic, CTLFLAG_RW, 0, "Generic link-management");
1046