xref: /freebsd/sys/netinet/in.c (revision ab0b9f6b3073e6c4d1dfbf07444d7db67a189a96)
1 /*-
2  * Copyright (c) 1982, 1986, 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  * Copyright (C) 2001 WIDE Project.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 4. Neither the name of the University nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  *	@(#)in.c	8.4 (Berkeley) 1/9/95
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include "opt_mpath.h"
37 
38 #include <sys/param.h>
39 #include <sys/eventhandler.h>
40 #include <sys/systm.h>
41 #include <sys/sockio.h>
42 #include <sys/malloc.h>
43 #include <sys/priv.h>
44 #include <sys/socket.h>
45 #include <sys/jail.h>
46 #include <sys/kernel.h>
47 #include <sys/proc.h>
48 #include <sys/sysctl.h>
49 #include <sys/syslog.h>
50 #include <sys/sx.h>
51 
52 #include <net/if.h>
53 #include <net/if_var.h>
54 #include <net/if_arp.h>
55 #include <net/if_dl.h>
56 #include <net/if_llatbl.h>
57 #include <net/if_types.h>
58 #include <net/route.h>
59 #include <net/vnet.h>
60 
61 #include <netinet/if_ether.h>
62 #include <netinet/in.h>
63 #include <netinet/in_var.h>
64 #include <netinet/in_pcb.h>
65 #include <netinet/ip_var.h>
66 #include <netinet/ip_carp.h>
67 #include <netinet/igmp_var.h>
68 #include <netinet/udp.h>
69 #include <netinet/udp_var.h>
70 
71 static int in_aifaddr_ioctl(u_long, caddr_t, struct ifnet *, struct thread *);
72 static int in_difaddr_ioctl(caddr_t, struct ifnet *, struct thread *);
73 
74 static void	in_socktrim(struct sockaddr_in *);
75 static void	in_purgemaddrs(struct ifnet *);
76 
77 static VNET_DEFINE(int, nosameprefix);
78 #define	V_nosameprefix			VNET(nosameprefix)
79 SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, no_same_prefix, CTLFLAG_RW,
80 	&VNET_NAME(nosameprefix), 0,
81 	"Refuse to create same prefixes on different interfaces");
82 
83 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
84 #define	V_ripcbinfo			VNET(ripcbinfo)
85 
86 static struct sx in_control_sx;
87 SX_SYSINIT(in_control_sx, &in_control_sx, "in_control");
88 
89 /*
90  * Return 1 if an internet address is for a ``local'' host
91  * (one to which we have a connection).
92  */
93 int
94 in_localaddr(struct in_addr in)
95 {
96 	register u_long i = ntohl(in.s_addr);
97 	register struct in_ifaddr *ia;
98 
99 	IN_IFADDR_RLOCK();
100 	TAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
101 		if ((i & ia->ia_subnetmask) == ia->ia_subnet) {
102 			IN_IFADDR_RUNLOCK();
103 			return (1);
104 		}
105 	}
106 	IN_IFADDR_RUNLOCK();
107 	return (0);
108 }
109 
110 /*
111  * Return 1 if an internet address is for the local host and configured
112  * on one of its interfaces.
113  */
114 int
115 in_localip(struct in_addr in)
116 {
117 	struct in_ifaddr *ia;
118 
119 	IN_IFADDR_RLOCK();
120 	LIST_FOREACH(ia, INADDR_HASH(in.s_addr), ia_hash) {
121 		if (IA_SIN(ia)->sin_addr.s_addr == in.s_addr) {
122 			IN_IFADDR_RUNLOCK();
123 			return (1);
124 		}
125 	}
126 	IN_IFADDR_RUNLOCK();
127 	return (0);
128 }
129 
130 /*
131  * Return a reference to the interface address which is different to
132  * the supplied one but with same IP address value.
133  */
134 static struct in_ifaddr *
135 in_localip_more(struct in_ifaddr *ia)
136 {
137 	in_addr_t in = IA_SIN(ia)->sin_addr.s_addr;
138 	struct in_ifaddr *it;
139 
140 	IN_IFADDR_RLOCK();
141 	LIST_FOREACH(it, INADDR_HASH(in), ia_hash) {
142 		if (it != ia && IA_SIN(it)->sin_addr.s_addr == in) {
143 			ifa_ref(&it->ia_ifa);
144 			IN_IFADDR_RUNLOCK();
145 			return (it);
146 		}
147 	}
148 	IN_IFADDR_RUNLOCK();
149 
150 	return (NULL);
151 }
152 
153 /*
154  * Determine whether an IP address is in a reserved set of addresses
155  * that may not be forwarded, or whether datagrams to that destination
156  * may be forwarded.
157  */
158 int
159 in_canforward(struct in_addr in)
160 {
161 	register u_long i = ntohl(in.s_addr);
162 	register u_long net;
163 
164 	if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i) || IN_LINKLOCAL(i))
165 		return (0);
166 	if (IN_CLASSA(i)) {
167 		net = i & IN_CLASSA_NET;
168 		if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
169 			return (0);
170 	}
171 	return (1);
172 }
173 
174 /*
175  * Trim a mask in a sockaddr
176  */
177 static void
178 in_socktrim(struct sockaddr_in *ap)
179 {
180     register char *cplim = (char *) &ap->sin_addr;
181     register char *cp = (char *) (&ap->sin_addr + 1);
182 
183     ap->sin_len = 0;
184     while (--cp >= cplim)
185 	if (*cp) {
186 	    (ap)->sin_len = cp - (char *) (ap) + 1;
187 	    break;
188 	}
189 }
190 
191 /*
192  * Generic internet control operations (ioctl's).
193  */
194 int
195 in_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
196     struct thread *td)
197 {
198 	struct ifreq *ifr = (struct ifreq *)data;
199 	struct sockaddr_in *addr = (struct sockaddr_in *)&ifr->ifr_addr;
200 	struct ifaddr *ifa;
201 	struct in_ifaddr *ia;
202 	int error;
203 
204 	if (ifp == NULL)
205 		return (EADDRNOTAVAIL);
206 
207 	/*
208 	 * Filter out 4 ioctls we implement directly.  Forward the rest
209 	 * to specific functions and ifp->if_ioctl().
210 	 */
211 	switch (cmd) {
212 	case SIOCGIFADDR:
213 	case SIOCGIFBRDADDR:
214 	case SIOCGIFDSTADDR:
215 	case SIOCGIFNETMASK:
216 		break;
217 	case SIOCDIFADDR:
218 		sx_xlock(&in_control_sx);
219 		error = in_difaddr_ioctl(data, ifp, td);
220 		sx_xunlock(&in_control_sx);
221 		return (error);
222 	case OSIOCAIFADDR:	/* 9.x compat */
223 	case SIOCAIFADDR:
224 		sx_xlock(&in_control_sx);
225 		error = in_aifaddr_ioctl(cmd, data, ifp, td);
226 		sx_xunlock(&in_control_sx);
227 		return (error);
228 	case SIOCSIFADDR:
229 	case SIOCSIFBRDADDR:
230 	case SIOCSIFDSTADDR:
231 	case SIOCSIFNETMASK:
232 		/* We no longer support that old commands. */
233 		return (EINVAL);
234 	default:
235 		if (ifp->if_ioctl == NULL)
236 			return (EOPNOTSUPP);
237 		return ((*ifp->if_ioctl)(ifp, cmd, data));
238 	}
239 
240 	if (addr->sin_addr.s_addr != INADDR_ANY &&
241 	    prison_check_ip4(td->td_ucred, &addr->sin_addr) != 0)
242 		return (EADDRNOTAVAIL);
243 
244 	/*
245 	 * For SIOCGIFADDR, pick the first address.  For the rest of
246 	 * ioctls, try to find specified address.
247 	 */
248 	IF_ADDR_RLOCK(ifp);
249 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
250 		if (ifa->ifa_addr->sa_family != AF_INET)
251 			continue;
252 		ia = (struct in_ifaddr *)ifa;
253 		if (cmd == SIOCGIFADDR || addr->sin_addr.s_addr == INADDR_ANY)
254 			break;
255 		if (ia->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr)
256 			break;
257 	}
258 
259 	if (ifa == NULL) {
260 		IF_ADDR_RUNLOCK(ifp);
261 		return (EADDRNOTAVAIL);
262 	}
263 
264 	error = 0;
265 	switch (cmd) {
266 	case SIOCGIFADDR:
267 		*addr = ia->ia_addr;
268 		break;
269 
270 	case SIOCGIFBRDADDR:
271 		if ((ifp->if_flags & IFF_BROADCAST) == 0) {
272 			error = EINVAL;
273 			break;
274 		}
275 		*addr = ia->ia_broadaddr;
276 		break;
277 
278 	case SIOCGIFDSTADDR:
279 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0) {
280 			error = EINVAL;
281 			break;
282 		}
283 		*addr = ia->ia_dstaddr;
284 		break;
285 
286 	case SIOCGIFNETMASK:
287 		*addr = ia->ia_sockmask;
288 		break;
289 	}
290 
291 	IF_ADDR_RUNLOCK(ifp);
292 
293 	return (error);
294 }
295 
296 static int
297 in_aifaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct thread *td)
298 {
299 	const struct in_aliasreq *ifra = (struct in_aliasreq *)data;
300 	const struct sockaddr_in *addr = &ifra->ifra_addr;
301 	const struct sockaddr_in *broadaddr = &ifra->ifra_broadaddr;
302 	const struct sockaddr_in *mask = &ifra->ifra_mask;
303 	const struct sockaddr_in *dstaddr = &ifra->ifra_dstaddr;
304 	const int vhid = (cmd == SIOCAIFADDR) ? ifra->ifra_vhid : 0;
305 	struct ifaddr *ifa;
306 	struct in_ifaddr *ia;
307 	bool iaIsFirst;
308 	int error = 0;
309 
310 	error = priv_check(td, PRIV_NET_ADDIFADDR);
311 	if (error)
312 		return (error);
313 
314 	/*
315 	 * ifra_addr must be present and be of INET family.
316 	 * ifra_broadaddr/ifra_dstaddr and ifra_mask are optional.
317 	 */
318 	if (addr->sin_len != sizeof(struct sockaddr_in) ||
319 	    addr->sin_family != AF_INET)
320 		return (EINVAL);
321 	if (broadaddr->sin_len != 0 &&
322 	    (broadaddr->sin_len != sizeof(struct sockaddr_in) ||
323 	    broadaddr->sin_family != AF_INET))
324 		return (EINVAL);
325 	if (mask->sin_len != 0 &&
326 	    (mask->sin_len != sizeof(struct sockaddr_in) ||
327 	    mask->sin_family != AF_INET))
328 		return (EINVAL);
329 	if ((ifp->if_flags & IFF_POINTOPOINT) &&
330 	    (dstaddr->sin_len != sizeof(struct sockaddr_in) ||
331 	     dstaddr->sin_addr.s_addr == INADDR_ANY))
332 		return (EDESTADDRREQ);
333 	if (vhid > 0 && carp_attach_p == NULL)
334 		return (EPROTONOSUPPORT);
335 
336 	/*
337 	 * See whether address already exist.
338 	 */
339 	iaIsFirst = true;
340 	ia = NULL;
341 	IF_ADDR_RLOCK(ifp);
342 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
343 		struct in_ifaddr *it;
344 
345 		if (ifa->ifa_addr->sa_family != AF_INET)
346 			continue;
347 
348 		it = (struct in_ifaddr *)ifa;
349 		iaIsFirst = false;
350 		if (it->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr &&
351 		    prison_check_ip4(td->td_ucred, &addr->sin_addr) == 0)
352 			ia = it;
353 	}
354 	IF_ADDR_RUNLOCK(ifp);
355 
356 	if (ia != NULL)
357 		(void )in_difaddr_ioctl(data, ifp, td);
358 
359 	ifa = ifa_alloc(sizeof(struct in_ifaddr), M_WAITOK);
360 	ia = (struct in_ifaddr *)ifa;
361 	ifa->ifa_addr = (struct sockaddr *)&ia->ia_addr;
362 	ifa->ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr;
363 	ifa->ifa_netmask = (struct sockaddr *)&ia->ia_sockmask;
364 
365 	ia->ia_ifp = ifp;
366 	ia->ia_ifa.ifa_metric = ifp->if_metric;
367 	ia->ia_addr = *addr;
368 	if (mask->sin_len != 0) {
369 		ia->ia_sockmask = *mask;
370 		ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr);
371 	} else {
372 		in_addr_t i = ntohl(addr->sin_addr.s_addr);
373 
374 		/*
375 	 	 * Be compatible with network classes, if netmask isn't
376 		 * supplied, guess it based on classes.
377 	 	 */
378 		if (IN_CLASSA(i))
379 			ia->ia_subnetmask = IN_CLASSA_NET;
380 		else if (IN_CLASSB(i))
381 			ia->ia_subnetmask = IN_CLASSB_NET;
382 		else
383 			ia->ia_subnetmask = IN_CLASSC_NET;
384 		ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
385 	}
386 	ia->ia_subnet = ntohl(addr->sin_addr.s_addr) & ia->ia_subnetmask;
387 	in_socktrim(&ia->ia_sockmask);
388 
389 	if (ifp->if_flags & IFF_BROADCAST) {
390 		if (broadaddr->sin_len != 0) {
391 			ia->ia_broadaddr = *broadaddr;
392 		} else if (ia->ia_subnetmask == IN_RFC3021_MASK) {
393 			ia->ia_broadaddr.sin_addr.s_addr = INADDR_BROADCAST;
394 			ia->ia_broadaddr.sin_len = sizeof(struct sockaddr_in);
395 			ia->ia_broadaddr.sin_family = AF_INET;
396 		} else {
397 			ia->ia_broadaddr.sin_addr.s_addr =
398 			    htonl(ia->ia_subnet | ~ia->ia_subnetmask);
399 			ia->ia_broadaddr.sin_len = sizeof(struct sockaddr_in);
400 			ia->ia_broadaddr.sin_family = AF_INET;
401 		}
402 	}
403 
404 	if (ifp->if_flags & IFF_POINTOPOINT)
405 		ia->ia_dstaddr = *dstaddr;
406 
407 	/* XXXGL: rtinit() needs this strange assignment. */
408 	if (ifp->if_flags & IFF_LOOPBACK)
409                 ia->ia_dstaddr = ia->ia_addr;
410 
411 	ifa_ref(ifa);			/* if_addrhead */
412 	IF_ADDR_WLOCK(ifp);
413 	TAILQ_INSERT_TAIL(&ifp->if_addrhead, ifa, ifa_link);
414 	IF_ADDR_WUNLOCK(ifp);
415 
416 	ifa_ref(ifa);			/* in_ifaddrhead */
417 	IN_IFADDR_WLOCK();
418 	TAILQ_INSERT_TAIL(&V_in_ifaddrhead, ia, ia_link);
419 	LIST_INSERT_HEAD(INADDR_HASH(ia->ia_addr.sin_addr.s_addr), ia, ia_hash);
420 	IN_IFADDR_WUNLOCK();
421 
422 	if (vhid != 0)
423 		error = (*carp_attach_p)(&ia->ia_ifa, vhid);
424 	if (error)
425 		goto fail1;
426 
427 	/*
428 	 * Give the interface a chance to initialize
429 	 * if this is its first address,
430 	 * and to validate the address if necessary.
431 	 */
432 	if (ifp->if_ioctl != NULL)
433 		error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia);
434 	if (error)
435 		goto fail2;
436 
437 	/*
438 	 * Add route for the network.
439 	 */
440 	if (vhid == 0) {
441 		int flags = RTF_UP;
442 
443 		if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT))
444 			flags |= RTF_HOST;
445 
446 		error = in_addprefix(ia, flags);
447 		if (error)
448 			goto fail2;
449 	}
450 
451 	/*
452 	 * Add a loopback route to self.
453 	 */
454 	if (vhid == 0 && (ifp->if_flags & IFF_LOOPBACK) == 0 &&
455 	    ia->ia_addr.sin_addr.s_addr != INADDR_ANY &&
456 	    !((ifp->if_flags & IFF_POINTOPOINT) &&
457 	     ia->ia_dstaddr.sin_addr.s_addr == ia->ia_addr.sin_addr.s_addr)) {
458 		struct in_ifaddr *eia;
459 
460 		eia = in_localip_more(ia);
461 
462 		if (eia == NULL) {
463 			error = ifa_add_loopback_route((struct ifaddr *)ia,
464 			    (struct sockaddr *)&ia->ia_addr);
465 			if (error)
466 				goto fail3;
467 		} else
468 			ifa_free(&eia->ia_ifa);
469 	}
470 
471 	if (iaIsFirst && (ifp->if_flags & IFF_MULTICAST)) {
472 		struct in_addr allhosts_addr;
473 		struct in_ifinfo *ii;
474 
475 		ii = ((struct in_ifinfo *)ifp->if_afdata[AF_INET]);
476 		allhosts_addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
477 
478 		error = in_joingroup(ifp, &allhosts_addr, NULL,
479 			&ii->ii_allhosts);
480 	}
481 
482 	EVENTHANDLER_INVOKE(ifaddr_event, ifp);
483 
484 	return (error);
485 
486 fail3:
487 	if (vhid == 0)
488 		(void )in_scrubprefix(ia, LLE_STATIC);
489 
490 fail2:
491 	if (ia->ia_ifa.ifa_carp)
492 		(*carp_detach_p)(&ia->ia_ifa);
493 
494 fail1:
495 	IF_ADDR_WLOCK(ifp);
496 	TAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifa_link);
497 	IF_ADDR_WUNLOCK(ifp);
498 	ifa_free(&ia->ia_ifa);
499 
500 	IN_IFADDR_WLOCK();
501 	TAILQ_REMOVE(&V_in_ifaddrhead, ia, ia_link);
502 	LIST_REMOVE(ia, ia_hash);
503 	IN_IFADDR_WUNLOCK();
504 	ifa_free(&ia->ia_ifa);
505 
506 	return (error);
507 }
508 
509 static int
510 in_difaddr_ioctl(caddr_t data, struct ifnet *ifp, struct thread *td)
511 {
512 	const struct ifreq *ifr = (struct ifreq *)data;
513 	const struct sockaddr_in *addr = (const struct sockaddr_in *)
514 	    &ifr->ifr_addr;
515 	struct ifaddr *ifa;
516 	struct in_ifaddr *ia;
517 	bool deleteAny, iaIsLast;
518 	int error;
519 
520 	if (td != NULL) {
521 		error = priv_check(td, PRIV_NET_DELIFADDR);
522 		if (error)
523 			return (error);
524 	}
525 
526 	if (addr->sin_len != sizeof(struct sockaddr_in) ||
527 	    addr->sin_family != AF_INET)
528 		deleteAny = true;
529 	else
530 		deleteAny = false;
531 
532 	iaIsLast = true;
533 	ia = NULL;
534 	IF_ADDR_WLOCK(ifp);
535 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
536 		struct in_ifaddr *it;
537 
538 		if (ifa->ifa_addr->sa_family != AF_INET)
539 			continue;
540 
541 		it = (struct in_ifaddr *)ifa;
542 		if (deleteAny && ia == NULL && (td == NULL ||
543 		    prison_check_ip4(td->td_ucred, &it->ia_addr.sin_addr) == 0))
544 			ia = it;
545 
546 		if (it->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr &&
547 		    (td == NULL || prison_check_ip4(td->td_ucred,
548 		    &addr->sin_addr) == 0))
549 			ia = it;
550 
551 		if (it != ia)
552 			iaIsLast = false;
553 	}
554 
555 	if (ia == NULL) {
556 		IF_ADDR_WUNLOCK(ifp);
557 		return (EADDRNOTAVAIL);
558 	}
559 
560 	TAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifa_link);
561 	IF_ADDR_WUNLOCK(ifp);
562 	ifa_free(&ia->ia_ifa);		/* if_addrhead */
563 
564 	IN_IFADDR_WLOCK();
565 	TAILQ_REMOVE(&V_in_ifaddrhead, ia, ia_link);
566 	LIST_REMOVE(ia, ia_hash);
567 	IN_IFADDR_WUNLOCK();
568 	ifa_free(&ia->ia_ifa);		/* in_ifaddrhead */
569 
570 	/*
571 	 * in_scrubprefix() kills the interface route.
572 	 */
573 	in_scrubprefix(ia, LLE_STATIC);
574 
575 	/*
576 	 * in_ifadown gets rid of all the rest of
577 	 * the routes.  This is not quite the right
578 	 * thing to do, but at least if we are running
579 	 * a routing process they will come back.
580 	 */
581 	in_ifadown(&ia->ia_ifa, 1);
582 
583 	if (ia->ia_ifa.ifa_carp)
584 		(*carp_detach_p)(&ia->ia_ifa);
585 
586 	/*
587 	 * If this is the last IPv4 address configured on this
588 	 * interface, leave the all-hosts group.
589 	 * No state-change report need be transmitted.
590 	 */
591 	if (iaIsLast && (ifp->if_flags & IFF_MULTICAST)) {
592 		struct in_ifinfo *ii;
593 
594 		ii = ((struct in_ifinfo *)ifp->if_afdata[AF_INET]);
595 		IN_MULTI_LOCK();
596 		if (ii->ii_allhosts) {
597 			(void)in_leavegroup_locked(ii->ii_allhosts, NULL);
598 			ii->ii_allhosts = NULL;
599 		}
600 		IN_MULTI_UNLOCK();
601 	}
602 
603 	EVENTHANDLER_INVOKE(ifaddr_event, ifp);
604 
605 	return (0);
606 }
607 
608 #define rtinitflags(x) \
609 	((((x)->ia_ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) != 0) \
610 	    ? RTF_HOST : 0)
611 
612 /*
613  * Generate a routing message when inserting or deleting
614  * an interface address alias.
615  */
616 static void in_addralias_rtmsg(int cmd, struct in_addr *prefix,
617     struct in_ifaddr *target)
618 {
619 	struct route pfx_ro;
620 	struct sockaddr_in *pfx_addr;
621 	struct rtentry msg_rt;
622 
623 	/* QL: XXX
624 	 * This is a bit questionable because there is no
625 	 * additional route entry added/deleted for an address
626 	 * alias. Therefore this route report is inaccurate.
627 	 */
628 	bzero(&pfx_ro, sizeof(pfx_ro));
629 	pfx_addr = (struct sockaddr_in *)(&pfx_ro.ro_dst);
630 	pfx_addr->sin_len = sizeof(*pfx_addr);
631 	pfx_addr->sin_family = AF_INET;
632 	pfx_addr->sin_addr = *prefix;
633 	rtalloc_ign_fib(&pfx_ro, 0, 0);
634 	if (pfx_ro.ro_rt != NULL) {
635 		msg_rt = *pfx_ro.ro_rt;
636 
637 		/* QL: XXX
638 		 * Point the gateway to the new interface
639 		 * address as if a new prefix route entry has
640 		 * been added through the new address alias.
641 		 * All other parts of the rtentry is accurate,
642 		 * e.g., rt_key, rt_mask, rt_ifp etc.
643 		 */
644 		msg_rt.rt_gateway = (struct sockaddr *)&target->ia_addr;
645 		rt_newaddrmsg(cmd, (struct ifaddr *)target, 0, &msg_rt);
646 		RTFREE(pfx_ro.ro_rt);
647 	}
648 	return;
649 }
650 
651 /*
652  * Check if we have a route for the given prefix already or add one accordingly.
653  */
654 int
655 in_addprefix(struct in_ifaddr *target, int flags)
656 {
657 	struct in_ifaddr *ia;
658 	struct in_addr prefix, mask, p, m;
659 	int error;
660 
661 	if ((flags & RTF_HOST) != 0) {
662 		prefix = target->ia_dstaddr.sin_addr;
663 		mask.s_addr = 0;
664 	} else {
665 		prefix = target->ia_addr.sin_addr;
666 		mask = target->ia_sockmask.sin_addr;
667 		prefix.s_addr &= mask.s_addr;
668 	}
669 
670 	IN_IFADDR_RLOCK();
671 	TAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
672 		if (rtinitflags(ia)) {
673 			p = ia->ia_dstaddr.sin_addr;
674 
675 			if (prefix.s_addr != p.s_addr)
676 				continue;
677 		} else {
678 			p = ia->ia_addr.sin_addr;
679 			m = ia->ia_sockmask.sin_addr;
680 			p.s_addr &= m.s_addr;
681 
682 			if (prefix.s_addr != p.s_addr ||
683 			    mask.s_addr != m.s_addr)
684 				continue;
685 		}
686 
687 		/*
688 		 * If we got a matching prefix route inserted by other
689 		 * interface address, we are done here.
690 		 */
691 		if (ia->ia_flags & IFA_ROUTE) {
692 #ifdef RADIX_MPATH
693 			if (ia->ia_addr.sin_addr.s_addr ==
694 			    target->ia_addr.sin_addr.s_addr) {
695 				IN_IFADDR_RUNLOCK();
696 				return (EEXIST);
697 			} else
698 				break;
699 #endif
700 			if (V_nosameprefix) {
701 				IN_IFADDR_RUNLOCK();
702 				return (EEXIST);
703 			} else {
704 				in_addralias_rtmsg(RTM_ADD, &prefix, target);
705 				IN_IFADDR_RUNLOCK();
706 				return (0);
707 			}
708 		}
709 	}
710 	IN_IFADDR_RUNLOCK();
711 
712 	/*
713 	 * No-one seem to have this prefix route, so we try to insert it.
714 	 */
715 	error = rtinit(&target->ia_ifa, (int)RTM_ADD, flags);
716 	if (!error)
717 		target->ia_flags |= IFA_ROUTE;
718 	return (error);
719 }
720 
721 /*
722  * If there is no other address in the system that can serve a route to the
723  * same prefix, remove the route.  Hand over the route to the new address
724  * otherwise.
725  */
726 int
727 in_scrubprefix(struct in_ifaddr *target, u_int flags)
728 {
729 	struct in_ifaddr *ia;
730 	struct in_addr prefix, mask, p, m;
731 	int error = 0;
732 	struct sockaddr_in prefix0, mask0;
733 
734 	/*
735 	 * Remove the loopback route to the interface address.
736 	 */
737 	if ((target->ia_addr.sin_addr.s_addr != INADDR_ANY) &&
738 	    !(target->ia_ifp->if_flags & IFF_LOOPBACK) &&
739 	    (flags & LLE_STATIC)) {
740 		struct in_ifaddr *eia;
741 
742 		eia = in_localip_more(target);
743 
744 		if (eia != NULL) {
745 			error = ifa_switch_loopback_route((struct ifaddr *)eia,
746 			    (struct sockaddr *)&target->ia_addr);
747 			ifa_free(&eia->ia_ifa);
748 		} else {
749 			error = ifa_del_loopback_route((struct ifaddr *)target,
750 			    (struct sockaddr *)&target->ia_addr);
751 		}
752 
753 		if (!(target->ia_ifp->if_flags & IFF_NOARP))
754 			/* remove arp cache */
755 			arp_ifscrub(target->ia_ifp,
756 			    IA_SIN(target)->sin_addr.s_addr);
757 	}
758 
759 	if (rtinitflags(target)) {
760 		prefix = target->ia_dstaddr.sin_addr;
761 		mask.s_addr = 0;
762 	} else {
763 		prefix = target->ia_addr.sin_addr;
764 		mask = target->ia_sockmask.sin_addr;
765 		prefix.s_addr &= mask.s_addr;
766 	}
767 
768 	if ((target->ia_flags & IFA_ROUTE) == 0) {
769 		in_addralias_rtmsg(RTM_DELETE, &prefix, target);
770 		return (0);
771 	}
772 
773 	IN_IFADDR_RLOCK();
774 	TAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
775 		if (rtinitflags(ia)) {
776 			p = ia->ia_dstaddr.sin_addr;
777 
778 			if (prefix.s_addr != p.s_addr)
779 				continue;
780 		} else {
781 			p = ia->ia_addr.sin_addr;
782 			m = ia->ia_sockmask.sin_addr;
783 			p.s_addr &= m.s_addr;
784 
785 			if (prefix.s_addr != p.s_addr ||
786 			    mask.s_addr != m.s_addr)
787 				continue;
788 		}
789 
790 		if ((ia->ia_ifp->if_flags & IFF_UP) == 0)
791 			continue;
792 
793 		/*
794 		 * If we got a matching prefix address, move IFA_ROUTE and
795 		 * the route itself to it.  Make sure that routing daemons
796 		 * get a heads-up.
797 		 */
798 		if ((ia->ia_flags & IFA_ROUTE) == 0) {
799 			ifa_ref(&ia->ia_ifa);
800 			IN_IFADDR_RUNLOCK();
801 			error = rtinit(&(target->ia_ifa), (int)RTM_DELETE,
802 			    rtinitflags(target));
803 			if (error == 0)
804 				target->ia_flags &= ~IFA_ROUTE;
805 			else
806 				log(LOG_INFO, "in_scrubprefix: err=%d, old prefix delete failed\n",
807 					error);
808 			error = rtinit(&ia->ia_ifa, (int)RTM_ADD,
809 			    rtinitflags(ia) | RTF_UP);
810 			if (error == 0)
811 				ia->ia_flags |= IFA_ROUTE;
812 			else
813 				log(LOG_INFO, "in_scrubprefix: err=%d, new prefix add failed\n",
814 					error);
815 			ifa_free(&ia->ia_ifa);
816 			return (error);
817 		}
818 	}
819 	IN_IFADDR_RUNLOCK();
820 
821 	/*
822 	 * remove all L2 entries on the given prefix
823 	 */
824 	bzero(&prefix0, sizeof(prefix0));
825 	prefix0.sin_len = sizeof(prefix0);
826 	prefix0.sin_family = AF_INET;
827 	prefix0.sin_addr.s_addr = target->ia_subnet;
828 	bzero(&mask0, sizeof(mask0));
829 	mask0.sin_len = sizeof(mask0);
830 	mask0.sin_family = AF_INET;
831 	mask0.sin_addr.s_addr = target->ia_subnetmask;
832 	lltable_prefix_free(AF_INET, (struct sockaddr *)&prefix0,
833 	    (struct sockaddr *)&mask0, flags);
834 
835 	/*
836 	 * As no-one seem to have this prefix, we can remove the route.
837 	 */
838 	error = rtinit(&(target->ia_ifa), (int)RTM_DELETE, rtinitflags(target));
839 	if (error == 0)
840 		target->ia_flags &= ~IFA_ROUTE;
841 	else
842 		log(LOG_INFO, "in_scrubprefix: err=%d, prefix delete failed\n", error);
843 	return (error);
844 }
845 
846 #undef rtinitflags
847 
848 /*
849  * Return 1 if the address might be a local broadcast address.
850  */
851 int
852 in_broadcast(struct in_addr in, struct ifnet *ifp)
853 {
854 	register struct ifaddr *ifa;
855 	u_long t;
856 
857 	if (in.s_addr == INADDR_BROADCAST ||
858 	    in.s_addr == INADDR_ANY)
859 		return (1);
860 	if ((ifp->if_flags & IFF_BROADCAST) == 0)
861 		return (0);
862 	t = ntohl(in.s_addr);
863 	/*
864 	 * Look through the list of addresses for a match
865 	 * with a broadcast address.
866 	 */
867 #define ia ((struct in_ifaddr *)ifa)
868 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
869 		if (ifa->ifa_addr->sa_family == AF_INET &&
870 		    (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
871 		     /*
872 		      * Check for old-style (host 0) broadcast, but
873 		      * taking into account that RFC 3021 obsoletes it.
874 		      */
875 		    (ia->ia_subnetmask != IN_RFC3021_MASK &&
876 		    t == ia->ia_subnet)) &&
877 		     /*
878 		      * Check for an all one subnetmask. These
879 		      * only exist when an interface gets a secondary
880 		      * address.
881 		      */
882 		    ia->ia_subnetmask != (u_long)0xffffffff)
883 			    return (1);
884 	return (0);
885 #undef ia
886 }
887 
888 /*
889  * On interface removal, clean up IPv4 data structures hung off of the ifnet.
890  */
891 void
892 in_ifdetach(struct ifnet *ifp)
893 {
894 
895 	in_pcbpurgeif0(&V_ripcbinfo, ifp);
896 	in_pcbpurgeif0(&V_udbinfo, ifp);
897 	in_purgemaddrs(ifp);
898 }
899 
900 /*
901  * Delete all IPv4 multicast address records, and associated link-layer
902  * multicast address records, associated with ifp.
903  * XXX It looks like domifdetach runs AFTER the link layer cleanup.
904  * XXX This should not race with ifma_protospec being set during
905  * a new allocation, if it does, we have bigger problems.
906  */
907 static void
908 in_purgemaddrs(struct ifnet *ifp)
909 {
910 	LIST_HEAD(,in_multi) purgeinms;
911 	struct in_multi		*inm, *tinm;
912 	struct ifmultiaddr	*ifma;
913 
914 	LIST_INIT(&purgeinms);
915 	IN_MULTI_LOCK();
916 
917 	/*
918 	 * Extract list of in_multi associated with the detaching ifp
919 	 * which the PF_INET layer is about to release.
920 	 * We need to do this as IF_ADDR_LOCK() may be re-acquired
921 	 * by code further down.
922 	 */
923 	IF_ADDR_RLOCK(ifp);
924 	TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
925 		if (ifma->ifma_addr->sa_family != AF_INET ||
926 		    ifma->ifma_protospec == NULL)
927 			continue;
928 #if 0
929 		KASSERT(ifma->ifma_protospec != NULL,
930 		    ("%s: ifma_protospec is NULL", __func__));
931 #endif
932 		inm = (struct in_multi *)ifma->ifma_protospec;
933 		LIST_INSERT_HEAD(&purgeinms, inm, inm_link);
934 	}
935 	IF_ADDR_RUNLOCK(ifp);
936 
937 	LIST_FOREACH_SAFE(inm, &purgeinms, inm_link, tinm) {
938 		LIST_REMOVE(inm, inm_link);
939 		inm_release_locked(inm);
940 	}
941 	igmp_ifdetach(ifp);
942 
943 	IN_MULTI_UNLOCK();
944 }
945 
946 struct in_llentry {
947 	struct llentry		base;
948 	struct sockaddr_in	l3_addr4;
949 };
950 
951 /*
952  * Deletes an address from the address table.
953  * This function is called by the timer functions
954  * such as arptimer() and nd6_llinfo_timer(), and
955  * the caller does the locking.
956  */
957 static void
958 in_lltable_free(struct lltable *llt, struct llentry *lle)
959 {
960 	LLE_WUNLOCK(lle);
961 	LLE_LOCK_DESTROY(lle);
962 	free(lle, M_LLTABLE);
963 }
964 
965 static struct llentry *
966 in_lltable_new(const struct sockaddr *l3addr, u_int flags)
967 {
968 	struct in_llentry *lle;
969 
970 	lle = malloc(sizeof(struct in_llentry), M_LLTABLE, M_NOWAIT | M_ZERO);
971 	if (lle == NULL)		/* NB: caller generates msg */
972 		return NULL;
973 
974 	/*
975 	 * For IPv4 this will trigger "arpresolve" to generate
976 	 * an ARP request.
977 	 */
978 	lle->base.la_expire = time_uptime; /* mark expired */
979 	lle->l3_addr4 = *(const struct sockaddr_in *)l3addr;
980 	lle->base.lle_refcnt = 1;
981 	lle->base.lle_free = in_lltable_free;
982 	LLE_LOCK_INIT(&lle->base);
983 	callout_init_rw(&lle->base.la_timer, &lle->base.lle_lock,
984 	    CALLOUT_RETURNUNLOCKED);
985 
986 	return (&lle->base);
987 }
988 
989 #define IN_ARE_MASKED_ADDR_EQUAL(d, a, m)	(			\
990 	    (((ntohl((d)->sin_addr.s_addr) ^ (a)->sin_addr.s_addr) & (m)->sin_addr.s_addr)) == 0 )
991 
992 static void
993 in_lltable_prefix_free(struct lltable *llt, const struct sockaddr *prefix,
994     const struct sockaddr *mask, u_int flags)
995 {
996 	const struct sockaddr_in *pfx = (const struct sockaddr_in *)prefix;
997 	const struct sockaddr_in *msk = (const struct sockaddr_in *)mask;
998 	struct llentry *lle, *next;
999 	int i;
1000 	size_t pkts_dropped;
1001 
1002 	IF_AFDATA_WLOCK(llt->llt_ifp);
1003 	for (i = 0; i < LLTBL_HASHTBL_SIZE; i++) {
1004 		LIST_FOREACH_SAFE(lle, &llt->lle_head[i], lle_next, next) {
1005 			/*
1006 			 * (flags & LLE_STATIC) means deleting all entries
1007 			 * including static ARP entries.
1008 			 */
1009 			if (IN_ARE_MASKED_ADDR_EQUAL(satosin(L3_ADDR(lle)),
1010 			    pfx, msk) && ((flags & LLE_STATIC) ||
1011 			    !(lle->la_flags & LLE_STATIC))) {
1012 				LLE_WLOCK(lle);
1013 				if (callout_stop(&lle->la_timer))
1014 					LLE_REMREF(lle);
1015 				pkts_dropped = llentry_free(lle);
1016 				ARPSTAT_ADD(dropped, pkts_dropped);
1017 			}
1018 		}
1019 	}
1020 	IF_AFDATA_WUNLOCK(llt->llt_ifp);
1021 }
1022 
1023 
1024 static int
1025 in_lltable_rtcheck(struct ifnet *ifp, u_int flags, const struct sockaddr *l3addr)
1026 {
1027 	struct rtentry *rt;
1028 
1029 	KASSERT(l3addr->sa_family == AF_INET,
1030 	    ("sin_family %d", l3addr->sa_family));
1031 
1032 	/* XXX rtalloc1 should take a const param */
1033 	rt = rtalloc1(__DECONST(struct sockaddr *, l3addr), 0, 0);
1034 
1035 	if (rt == NULL)
1036 		return (EINVAL);
1037 
1038 	/*
1039 	 * If the gateway for an existing host route matches the target L3
1040 	 * address, which is a special route inserted by some implementation
1041 	 * such as MANET, and the interface is of the correct type, then
1042 	 * allow for ARP to proceed.
1043 	 */
1044 	if (rt->rt_flags & RTF_GATEWAY) {
1045 		if (!(rt->rt_flags & RTF_HOST) || !rt->rt_ifp ||
1046 		    rt->rt_ifp->if_type != IFT_ETHER ||
1047 		    (rt->rt_ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) != 0 ||
1048 		    memcmp(rt->rt_gateway->sa_data, l3addr->sa_data,
1049 		    sizeof(in_addr_t)) != 0) {
1050 			RTFREE_LOCKED(rt);
1051 			return (EINVAL);
1052 		}
1053 	}
1054 
1055 	/*
1056 	 * Make sure that at least the destination address is covered
1057 	 * by the route. This is for handling the case where 2 or more
1058 	 * interfaces have the same prefix. An incoming packet arrives
1059 	 * on one interface and the corresponding outgoing packet leaves
1060 	 * another interface.
1061 	 */
1062 	if (!(rt->rt_flags & RTF_HOST) && rt->rt_ifp != ifp) {
1063 		const char *sa, *mask, *addr, *lim;
1064 		int len;
1065 
1066 		mask = (const char *)rt_mask(rt);
1067 		/*
1068 		 * Just being extra cautious to avoid some custom
1069 		 * code getting into trouble.
1070 		 */
1071 		if (mask == NULL) {
1072 			RTFREE_LOCKED(rt);
1073 			return (EINVAL);
1074 		}
1075 
1076 		sa = (const char *)rt_key(rt);
1077 		addr = (const char *)l3addr;
1078 		len = ((const struct sockaddr_in *)l3addr)->sin_len;
1079 		lim = addr + len;
1080 
1081 		for ( ; addr < lim; sa++, mask++, addr++) {
1082 			if ((*sa ^ *addr) & *mask) {
1083 #ifdef DIAGNOSTIC
1084 				log(LOG_INFO, "IPv4 address: \"%s\" is not on the network\n",
1085 				    inet_ntoa(((const struct sockaddr_in *)l3addr)->sin_addr));
1086 #endif
1087 				RTFREE_LOCKED(rt);
1088 				return (EINVAL);
1089 			}
1090 		}
1091 	}
1092 
1093 	RTFREE_LOCKED(rt);
1094 	return (0);
1095 }
1096 
1097 /*
1098  * Return NULL if not found or marked for deletion.
1099  * If found return lle read locked.
1100  */
1101 static struct llentry *
1102 in_lltable_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
1103 {
1104 	const struct sockaddr_in *sin = (const struct sockaddr_in *)l3addr;
1105 	struct ifnet *ifp = llt->llt_ifp;
1106 	struct llentry *lle;
1107 	struct llentries *lleh;
1108 	u_int hashkey;
1109 
1110 	IF_AFDATA_LOCK_ASSERT(ifp);
1111 	KASSERT(l3addr->sa_family == AF_INET,
1112 	    ("sin_family %d", l3addr->sa_family));
1113 
1114 	hashkey = sin->sin_addr.s_addr;
1115 	lleh = &llt->lle_head[LLATBL_HASH(hashkey, LLTBL_HASHMASK)];
1116 	LIST_FOREACH(lle, lleh, lle_next) {
1117 		struct sockaddr_in *sa2 = satosin(L3_ADDR(lle));
1118 		if (lle->la_flags & LLE_DELETED)
1119 			continue;
1120 		if (sa2->sin_addr.s_addr == sin->sin_addr.s_addr)
1121 			break;
1122 	}
1123 	if (lle == NULL) {
1124 #ifdef DIAGNOSTIC
1125 		if (flags & LLE_DELETE)
1126 			log(LOG_INFO, "interface address is missing from cache = %p  in delete\n", lle);
1127 #endif
1128 		if (!(flags & LLE_CREATE))
1129 			return (NULL);
1130 		/*
1131 		 * A route that covers the given address must have
1132 		 * been installed 1st because we are doing a resolution,
1133 		 * verify this.
1134 		 */
1135 		if (!(flags & LLE_IFADDR) &&
1136 		    in_lltable_rtcheck(ifp, flags, l3addr) != 0)
1137 			goto done;
1138 
1139 		lle = in_lltable_new(l3addr, flags);
1140 		if (lle == NULL) {
1141 			log(LOG_INFO, "lla_lookup: new lle malloc failed\n");
1142 			goto done;
1143 		}
1144 		lle->la_flags = flags & ~LLE_CREATE;
1145 		if ((flags & (LLE_CREATE | LLE_IFADDR)) == (LLE_CREATE | LLE_IFADDR)) {
1146 			bcopy(IF_LLADDR(ifp), &lle->ll_addr, ifp->if_addrlen);
1147 			lle->la_flags |= (LLE_VALID | LLE_STATIC);
1148 		}
1149 
1150 		lle->lle_tbl  = llt;
1151 		lle->lle_head = lleh;
1152 		lle->la_flags |= LLE_LINKED;
1153 		LIST_INSERT_HEAD(lleh, lle, lle_next);
1154 	} else if (flags & LLE_DELETE) {
1155 		if (!(lle->la_flags & LLE_IFADDR) || (flags & LLE_IFADDR)) {
1156 			LLE_WLOCK(lle);
1157 			lle->la_flags |= LLE_DELETED;
1158 			EVENTHANDLER_INVOKE(lle_event, lle, LLENTRY_DELETED);
1159 #ifdef DIAGNOSTIC
1160 			log(LOG_INFO, "ifaddr cache = %p is deleted\n", lle);
1161 #endif
1162 			if ((lle->la_flags &
1163 			    (LLE_STATIC | LLE_IFADDR)) == LLE_STATIC)
1164 				llentry_free(lle);
1165 			else
1166 				LLE_WUNLOCK(lle);
1167 		}
1168 		lle = (void *)-1;
1169 
1170 	}
1171 	if (LLE_IS_VALID(lle)) {
1172 		if (flags & LLE_EXCLUSIVE)
1173 			LLE_WLOCK(lle);
1174 		else
1175 			LLE_RLOCK(lle);
1176 	}
1177 done:
1178 	return (lle);
1179 }
1180 
1181 static int
1182 in_lltable_dump(struct lltable *llt, struct sysctl_req *wr)
1183 {
1184 #define	SIN(lle)	((struct sockaddr_in *) L3_ADDR(lle))
1185 	struct ifnet *ifp = llt->llt_ifp;
1186 	struct llentry *lle;
1187 	/* XXX stack use */
1188 	struct {
1189 		struct rt_msghdr	rtm;
1190 		struct sockaddr_in	sin;
1191 		struct sockaddr_dl	sdl;
1192 	} arpc;
1193 	int error, i;
1194 
1195 	LLTABLE_LOCK_ASSERT();
1196 
1197 	error = 0;
1198 	for (i = 0; i < LLTBL_HASHTBL_SIZE; i++) {
1199 		LIST_FOREACH(lle, &llt->lle_head[i], lle_next) {
1200 			struct sockaddr_dl *sdl;
1201 
1202 			/* skip deleted entries */
1203 			if ((lle->la_flags & LLE_DELETED) == LLE_DELETED)
1204 				continue;
1205 			/* Skip if jailed and not a valid IP of the prison. */
1206 			if (prison_if(wr->td->td_ucred, L3_ADDR(lle)) != 0)
1207 				continue;
1208 			/*
1209 			 * produce a msg made of:
1210 			 *  struct rt_msghdr;
1211 			 *  struct sockaddr_in; (IPv4)
1212 			 *  struct sockaddr_dl;
1213 			 */
1214 			bzero(&arpc, sizeof(arpc));
1215 			arpc.rtm.rtm_msglen = sizeof(arpc);
1216 			arpc.rtm.rtm_version = RTM_VERSION;
1217 			arpc.rtm.rtm_type = RTM_GET;
1218 			arpc.rtm.rtm_flags = RTF_UP;
1219 			arpc.rtm.rtm_addrs = RTA_DST | RTA_GATEWAY;
1220 			arpc.sin.sin_family = AF_INET;
1221 			arpc.sin.sin_len = sizeof(arpc.sin);
1222 			arpc.sin.sin_addr.s_addr = SIN(lle)->sin_addr.s_addr;
1223 
1224 			/* publish */
1225 			if (lle->la_flags & LLE_PUB)
1226 				arpc.rtm.rtm_flags |= RTF_ANNOUNCE;
1227 
1228 			sdl = &arpc.sdl;
1229 			sdl->sdl_family = AF_LINK;
1230 			sdl->sdl_len = sizeof(*sdl);
1231 			sdl->sdl_index = ifp->if_index;
1232 			sdl->sdl_type = ifp->if_type;
1233 			if ((lle->la_flags & LLE_VALID) == LLE_VALID) {
1234 				sdl->sdl_alen = ifp->if_addrlen;
1235 				bcopy(&lle->ll_addr, LLADDR(sdl), ifp->if_addrlen);
1236 			} else {
1237 				sdl->sdl_alen = 0;
1238 				bzero(LLADDR(sdl), ifp->if_addrlen);
1239 			}
1240 
1241 			arpc.rtm.rtm_rmx.rmx_expire =
1242 			    lle->la_flags & LLE_STATIC ? 0 : lle->la_expire;
1243 			arpc.rtm.rtm_flags |= (RTF_HOST | RTF_LLDATA);
1244 			if (lle->la_flags & LLE_STATIC)
1245 				arpc.rtm.rtm_flags |= RTF_STATIC;
1246 			arpc.rtm.rtm_index = ifp->if_index;
1247 			error = SYSCTL_OUT(wr, &arpc, sizeof(arpc));
1248 			if (error)
1249 				break;
1250 		}
1251 	}
1252 	return error;
1253 #undef SIN
1254 }
1255 
1256 void *
1257 in_domifattach(struct ifnet *ifp)
1258 {
1259 	struct in_ifinfo *ii;
1260 	struct lltable *llt;
1261 
1262 	ii = malloc(sizeof(struct in_ifinfo), M_IFADDR, M_WAITOK|M_ZERO);
1263 
1264 	llt = lltable_init(ifp, AF_INET);
1265 	if (llt != NULL) {
1266 		llt->llt_prefix_free = in_lltable_prefix_free;
1267 		llt->llt_lookup = in_lltable_lookup;
1268 		llt->llt_dump = in_lltable_dump;
1269 	}
1270 	ii->ii_llt = llt;
1271 
1272 	ii->ii_igmp = igmp_domifattach(ifp);
1273 
1274 	return ii;
1275 }
1276 
1277 void
1278 in_domifdetach(struct ifnet *ifp, void *aux)
1279 {
1280 	struct in_ifinfo *ii = (struct in_ifinfo *)aux;
1281 
1282 	igmp_domifdetach(ifp);
1283 	lltable_free(ii->ii_llt);
1284 	free(ii, M_IFADDR);
1285 }
1286