xref: /freebsd/sys/netinet/in.c (revision d5b0e70f7e04d971691517ce1304d86a1e367e2e)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1982, 1986, 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  * Copyright (C) 2001 WIDE Project.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	@(#)in.c	8.4 (Berkeley) 1/9/95
33  */
34 
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include "opt_inet.h"
39 
40 #define IN_HISTORICAL_NETS		/* include class masks */
41 
42 #include <sys/param.h>
43 #include <sys/eventhandler.h>
44 #include <sys/systm.h>
45 #include <sys/sockio.h>
46 #include <sys/malloc.h>
47 #include <sys/priv.h>
48 #include <sys/socket.h>
49 #include <sys/jail.h>
50 #include <sys/kernel.h>
51 #include <sys/lock.h>
52 #include <sys/proc.h>
53 #include <sys/sysctl.h>
54 #include <sys/syslog.h>
55 #include <sys/sx.h>
56 
57 #include <net/if.h>
58 #include <net/if_var.h>
59 #include <net/if_arp.h>
60 #include <net/if_dl.h>
61 #include <net/if_llatbl.h>
62 #include <net/if_types.h>
63 #include <net/route.h>
64 #include <net/route/nhop.h>
65 #include <net/route/route_ctl.h>
66 #include <net/vnet.h>
67 
68 #include <netinet/if_ether.h>
69 #include <netinet/in.h>
70 #include <netinet/in_fib.h>
71 #include <netinet/in_var.h>
72 #include <netinet/in_pcb.h>
73 #include <netinet/ip_var.h>
74 #include <netinet/ip_carp.h>
75 #include <netinet/igmp_var.h>
76 #include <netinet/udp.h>
77 #include <netinet/udp_var.h>
78 
79 static int in_aifaddr_ioctl(u_long, caddr_t, struct ifnet *, struct ucred *);
80 static int in_difaddr_ioctl(u_long, caddr_t, struct ifnet *, struct ucred *);
81 static int in_gifaddr_ioctl(u_long, caddr_t, struct ifnet *, struct ucred *);
82 
83 static void	in_socktrim(struct sockaddr_in *);
84 static void	in_purgemaddrs(struct ifnet *);
85 
86 static bool	ia_need_loopback_route(const struct in_ifaddr *);
87 
88 VNET_DEFINE_STATIC(int, nosameprefix);
89 #define	V_nosameprefix			VNET(nosameprefix)
90 SYSCTL_INT(_net_inet_ip, OID_AUTO, no_same_prefix, CTLFLAG_VNET | CTLFLAG_RW,
91 	&VNET_NAME(nosameprefix), 0,
92 	"Refuse to create same prefixes on different interfaces");
93 
94 VNET_DEFINE_STATIC(bool, broadcast_lowest);
95 #define	V_broadcast_lowest		VNET(broadcast_lowest)
96 SYSCTL_BOOL(_net_inet_ip, OID_AUTO, broadcast_lowest, CTLFLAG_VNET | CTLFLAG_RW,
97 	&VNET_NAME(broadcast_lowest), 0,
98 	"Treat lowest address on a subnet (host 0) as broadcast");
99 
100 VNET_DEFINE(bool, ip_allow_net240) = false;
101 #define	V_ip_allow_net240		VNET(ip_allow_net240)
102 SYSCTL_BOOL(_net_inet_ip, OID_AUTO, allow_net240,
103 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip_allow_net240), 0,
104 	"Allow use of Experimental addresses, aka Class E (240/4)");
105 /* see https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-240 */
106 
107 VNET_DEFINE(bool, ip_allow_net0) = false;
108 SYSCTL_BOOL(_net_inet_ip, OID_AUTO, allow_net0,
109 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip_allow_net0), 0,
110 	"Allow use of addresses in network 0/8");
111 /* see https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-0 */
112 
113 VNET_DEFINE(uint32_t, in_loopback_mask) = IN_LOOPBACK_MASK_DFLT;
114 #define	V_in_loopback_mask	VNET(in_loopback_mask)
115 static int sysctl_loopback_prefixlen(SYSCTL_HANDLER_ARGS);
116 SYSCTL_PROC(_net_inet_ip, OID_AUTO, loopback_prefixlen,
117 	CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW,
118 	NULL, 0, sysctl_loopback_prefixlen, "I",
119 	"Prefix length of address space reserved for loopback");
120 /* see https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-127 */
121 
122 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
123 #define	V_ripcbinfo			VNET(ripcbinfo)
124 
125 static struct sx in_control_sx;
126 SX_SYSINIT(in_control_sx, &in_control_sx, "in_control");
127 
128 /*
129  * Return 1 if an internet address is for a ``local'' host
130  * (one to which we have a connection).
131  */
132 int
133 in_localaddr(struct in_addr in)
134 {
135 	u_long i = ntohl(in.s_addr);
136 	struct in_ifaddr *ia;
137 
138 	NET_EPOCH_ASSERT();
139 
140 	CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
141 		if ((i & ia->ia_subnetmask) == ia->ia_subnet)
142 			return (1);
143 	}
144 
145 	return (0);
146 }
147 
148 /*
149  * Return 1 if an internet address is for the local host and configured
150  * on one of its interfaces.
151  */
152 bool
153 in_localip(struct in_addr in)
154 {
155 	struct in_ifaddr *ia;
156 
157 	NET_EPOCH_ASSERT();
158 
159 	CK_LIST_FOREACH(ia, INADDR_HASH(in.s_addr), ia_hash)
160 		if (IA_SIN(ia)->sin_addr.s_addr == in.s_addr)
161 			return (true);
162 
163 	return (false);
164 }
165 
166 /*
167  * Like in_localip(), but FIB-aware.
168  */
169 bool
170 in_localip_fib(struct in_addr in, uint16_t fib)
171 {
172 	struct in_ifaddr *ia;
173 
174 	NET_EPOCH_ASSERT();
175 
176 	CK_LIST_FOREACH(ia, INADDR_HASH(in.s_addr), ia_hash)
177 		if (IA_SIN(ia)->sin_addr.s_addr == in.s_addr &&
178 		    ia->ia_ifa.ifa_ifp->if_fib == fib)
179 			return (true);
180 
181 	return (false);
182 }
183 
184 /*
185  * Return 1 if an internet address is configured on an interface.
186  */
187 int
188 in_ifhasaddr(struct ifnet *ifp, struct in_addr in)
189 {
190 	struct ifaddr *ifa;
191 	struct in_ifaddr *ia;
192 
193 	NET_EPOCH_ASSERT();
194 
195 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
196 		if (ifa->ifa_addr->sa_family != AF_INET)
197 			continue;
198 		ia = (struct in_ifaddr *)ifa;
199 		if (ia->ia_addr.sin_addr.s_addr == in.s_addr)
200 			return (1);
201 	}
202 
203 	return (0);
204 }
205 
206 /*
207  * Return a reference to the interface address which is different to
208  * the supplied one but with same IP address value.
209  */
210 static struct in_ifaddr *
211 in_localip_more(struct in_ifaddr *original_ia)
212 {
213 	struct epoch_tracker et;
214 	in_addr_t original_addr = IA_SIN(original_ia)->sin_addr.s_addr;
215 	uint32_t original_fib = original_ia->ia_ifa.ifa_ifp->if_fib;
216 	struct in_ifaddr *ia;
217 
218 	NET_EPOCH_ENTER(et);
219 	CK_LIST_FOREACH(ia, INADDR_HASH(original_addr), ia_hash) {
220 		in_addr_t addr = IA_SIN(ia)->sin_addr.s_addr;
221 		uint32_t fib = ia->ia_ifa.ifa_ifp->if_fib;
222 		if (!V_rt_add_addr_allfibs && (original_fib != fib))
223 			continue;
224 		if ((original_ia != ia) && (original_addr == addr)) {
225 			ifa_ref(&ia->ia_ifa);
226 			NET_EPOCH_EXIT(et);
227 			return (ia);
228 		}
229 	}
230 	NET_EPOCH_EXIT(et);
231 
232 	return (NULL);
233 }
234 
235 /*
236  * Tries to find first IPv4 address in the provided fib.
237  * Prefers non-loopback addresses and return loopback IFF
238  * @loopback_ok is set.
239  *
240  * Returns ifa or NULL.
241  */
242 struct in_ifaddr *
243 in_findlocal(uint32_t fibnum, bool loopback_ok)
244 {
245 	struct in_ifaddr *ia = NULL, *ia_lo = NULL;
246 
247 	NET_EPOCH_ASSERT();
248 
249 	CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
250 		uint32_t ia_fib = ia->ia_ifa.ifa_ifp->if_fib;
251 		if (!V_rt_add_addr_allfibs && (fibnum != ia_fib))
252 			continue;
253 
254 		if (!IN_LOOPBACK(ntohl(IA_SIN(ia)->sin_addr.s_addr)))
255 			break;
256 		if (loopback_ok)
257 			ia_lo = ia;
258 	}
259 
260 	if (ia == NULL)
261 		ia = ia_lo;
262 
263 	return (ia);
264 }
265 
266 /*
267  * Determine whether an IP address is in a reserved set of addresses
268  * that may not be forwarded, or whether datagrams to that destination
269  * may be forwarded.
270  */
271 int
272 in_canforward(struct in_addr in)
273 {
274 	u_long i = ntohl(in.s_addr);
275 
276 	if (IN_MULTICAST(i) || IN_LINKLOCAL(i) || IN_LOOPBACK(i))
277 		return (0);
278 	if (IN_EXPERIMENTAL(i) && !V_ip_allow_net240)
279 		return (0);
280 	if (IN_ZERONET(i) && !V_ip_allow_net0)
281 		return (0);
282 	return (1);
283 }
284 
285 /*
286  * Sysctl to manage prefix of reserved loopback network; translate
287  * to/from mask.  The mask is always contiguous high-order 1 bits
288  * followed by all 0 bits.
289  */
290 static int
291 sysctl_loopback_prefixlen(SYSCTL_HANDLER_ARGS)
292 {
293 	int error, preflen;
294 
295 	/* ffs is 1-based; compensate. */
296 	preflen = 33 - ffs(V_in_loopback_mask);
297 	error = sysctl_handle_int(oidp, &preflen, 0, req);
298 	if (error || !req->newptr)
299 		return (error);
300 	if (preflen < 8 || preflen > 31)
301 		return (EINVAL);
302 	V_in_loopback_mask = 0xffffffff << (32 - preflen);
303 	return (0);
304 }
305 
306 /*
307  * Trim a mask in a sockaddr
308  */
309 static void
310 in_socktrim(struct sockaddr_in *ap)
311 {
312     char *cplim = (char *) &ap->sin_addr;
313     char *cp = (char *) (&ap->sin_addr + 1);
314 
315     ap->sin_len = 0;
316     while (--cp >= cplim)
317 	if (*cp) {
318 	    (ap)->sin_len = cp - (char *) (ap) + 1;
319 	    break;
320 	}
321 }
322 
323 /*
324  * Generic internet control operations (ioctl's).
325  */
326 int
327 in_control(struct socket *so, u_long cmd, void *data, struct ifnet *ifp,
328     struct thread *td)
329 {
330 	struct ifreq *ifr = (struct ifreq *)data;
331 	struct sockaddr_in *addr = (struct sockaddr_in *)&ifr->ifr_addr;
332 	struct epoch_tracker et;
333 	struct ifaddr *ifa;
334 	struct in_ifaddr *ia;
335 	int error;
336 
337 	if (ifp == NULL)
338 		return (EADDRNOTAVAIL);
339 
340 	struct ucred *cred = (td != NULL) ? td->td_ucred : NULL;
341 
342 	/*
343 	 * Filter out 4 ioctls we implement directly.  Forward the rest
344 	 * to specific functions and ifp->if_ioctl().
345 	 */
346 	switch (cmd) {
347 	case SIOCGIFADDR:
348 	case SIOCGIFBRDADDR:
349 	case SIOCGIFDSTADDR:
350 	case SIOCGIFNETMASK:
351 		break;
352 	case SIOCGIFALIAS:
353 		sx_xlock(&in_control_sx);
354 		error = in_gifaddr_ioctl(cmd, data, ifp, cred);
355 		sx_xunlock(&in_control_sx);
356 		return (error);
357 	case SIOCDIFADDR:
358 		sx_xlock(&in_control_sx);
359 		error = in_difaddr_ioctl(cmd, data, ifp, cred);
360 		sx_xunlock(&in_control_sx);
361 		return (error);
362 	case OSIOCAIFADDR:	/* 9.x compat */
363 	case SIOCAIFADDR:
364 		sx_xlock(&in_control_sx);
365 		error = in_aifaddr_ioctl(cmd, data, ifp, cred);
366 		sx_xunlock(&in_control_sx);
367 		return (error);
368 	case SIOCSIFADDR:
369 	case SIOCSIFBRDADDR:
370 	case SIOCSIFDSTADDR:
371 	case SIOCSIFNETMASK:
372 		/* We no longer support that old commands. */
373 		return (EINVAL);
374 	default:
375 		if (ifp->if_ioctl == NULL)
376 			return (EOPNOTSUPP);
377 		return ((*ifp->if_ioctl)(ifp, cmd, data));
378 	}
379 
380 	if (addr->sin_addr.s_addr != INADDR_ANY &&
381 	    prison_check_ip4(cred, &addr->sin_addr) != 0)
382 		return (EADDRNOTAVAIL);
383 
384 	/*
385 	 * Find address for this interface, if it exists.  If an
386 	 * address was specified, find that one instead of the
387 	 * first one on the interface, if possible.
388 	 */
389 	NET_EPOCH_ENTER(et);
390 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
391 		if (ifa->ifa_addr->sa_family != AF_INET)
392 			continue;
393 		ia = (struct in_ifaddr *)ifa;
394 		if (ia->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr)
395 			break;
396 	}
397 	if (ifa == NULL)
398 		CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
399 			if (ifa->ifa_addr->sa_family == AF_INET) {
400 				ia = (struct in_ifaddr *)ifa;
401 				if (prison_check_ip4(cred,
402 				    &ia->ia_addr.sin_addr) == 0)
403 					break;
404 			}
405 
406 	if (ifa == NULL) {
407 		NET_EPOCH_EXIT(et);
408 		return (EADDRNOTAVAIL);
409 	}
410 
411 	error = 0;
412 	switch (cmd) {
413 	case SIOCGIFADDR:
414 		*addr = ia->ia_addr;
415 		break;
416 
417 	case SIOCGIFBRDADDR:
418 		if ((ifp->if_flags & IFF_BROADCAST) == 0) {
419 			error = EINVAL;
420 			break;
421 		}
422 		*addr = ia->ia_broadaddr;
423 		break;
424 
425 	case SIOCGIFDSTADDR:
426 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0) {
427 			error = EINVAL;
428 			break;
429 		}
430 		*addr = ia->ia_dstaddr;
431 		break;
432 
433 	case SIOCGIFNETMASK:
434 		*addr = ia->ia_sockmask;
435 		break;
436 	}
437 
438 	NET_EPOCH_EXIT(et);
439 
440 	return (error);
441 }
442 
443 static int
444 in_aifaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct ucred *cred)
445 {
446 	const struct in_aliasreq *ifra = (struct in_aliasreq *)data;
447 	const struct sockaddr_in *addr = &ifra->ifra_addr;
448 	const struct sockaddr_in *broadaddr = &ifra->ifra_broadaddr;
449 	const struct sockaddr_in *mask = &ifra->ifra_mask;
450 	const struct sockaddr_in *dstaddr = &ifra->ifra_dstaddr;
451 	const int vhid = (cmd == SIOCAIFADDR) ? ifra->ifra_vhid : 0;
452 	struct epoch_tracker et;
453 	struct ifaddr *ifa;
454 	struct in_ifaddr *ia;
455 	bool iaIsFirst;
456 	int error = 0;
457 
458 	error = priv_check_cred(cred, PRIV_NET_ADDIFADDR);
459 	if (error)
460 		return (error);
461 
462 	/*
463 	 * ifra_addr must be present and be of INET family.
464 	 * ifra_broadaddr/ifra_dstaddr and ifra_mask are optional.
465 	 */
466 	if (addr->sin_len != sizeof(struct sockaddr_in) ||
467 	    addr->sin_family != AF_INET)
468 		return (EINVAL);
469 	if (broadaddr->sin_len != 0 &&
470 	    (broadaddr->sin_len != sizeof(struct sockaddr_in) ||
471 	    broadaddr->sin_family != AF_INET))
472 		return (EINVAL);
473 	if (mask->sin_len != 0 &&
474 	    (mask->sin_len != sizeof(struct sockaddr_in) ||
475 	    mask->sin_family != AF_INET))
476 		return (EINVAL);
477 	if ((ifp->if_flags & IFF_POINTOPOINT) &&
478 	    (dstaddr->sin_len != sizeof(struct sockaddr_in) ||
479 	     dstaddr->sin_addr.s_addr == INADDR_ANY))
480 		return (EDESTADDRREQ);
481 	if (vhid != 0 && carp_attach_p == NULL)
482 		return (EPROTONOSUPPORT);
483 
484 	/*
485 	 * See whether address already exist.
486 	 */
487 	iaIsFirst = true;
488 	ia = NULL;
489 	NET_EPOCH_ENTER(et);
490 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
491 		struct in_ifaddr *it;
492 
493 		if (ifa->ifa_addr->sa_family != AF_INET)
494 			continue;
495 
496 		it = (struct in_ifaddr *)ifa;
497 		if (it->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr &&
498 		    prison_check_ip4(cred, &addr->sin_addr) == 0)
499 			ia = it;
500 		else
501 			iaIsFirst = false;
502 	}
503 	NET_EPOCH_EXIT(et);
504 
505 	if (ia != NULL)
506 		(void )in_difaddr_ioctl(cmd, data, ifp, cred);
507 
508 	ifa = ifa_alloc(sizeof(struct in_ifaddr), M_WAITOK);
509 	ia = (struct in_ifaddr *)ifa;
510 	ifa->ifa_addr = (struct sockaddr *)&ia->ia_addr;
511 	ifa->ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr;
512 	ifa->ifa_netmask = (struct sockaddr *)&ia->ia_sockmask;
513 	callout_init_rw(&ia->ia_garp_timer, &ifp->if_addr_lock,
514 	    CALLOUT_RETURNUNLOCKED);
515 
516 	ia->ia_ifp = ifp;
517 	ia->ia_addr = *addr;
518 	if (mask->sin_len != 0) {
519 		ia->ia_sockmask = *mask;
520 		ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr);
521 	} else {
522 		in_addr_t i = ntohl(addr->sin_addr.s_addr);
523 
524 		/*
525 	 	 * If netmask isn't supplied, use historical default.
526 		 * This is deprecated for interfaces other than loopback
527 		 * or point-to-point; warn in other cases.  In the future
528 		 * we should return an error rather than warning.
529 	 	 */
530 		if ((ifp->if_flags & (IFF_POINTOPOINT | IFF_LOOPBACK)) == 0)
531 			printf("%s: set address: WARNING: network mask "
532 			     "should be specified; using historical default\n",
533 			     ifp->if_xname);
534 		if (IN_CLASSA(i))
535 			ia->ia_subnetmask = IN_CLASSA_NET;
536 		else if (IN_CLASSB(i))
537 			ia->ia_subnetmask = IN_CLASSB_NET;
538 		else
539 			ia->ia_subnetmask = IN_CLASSC_NET;
540 		ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
541 	}
542 	ia->ia_subnet = ntohl(addr->sin_addr.s_addr) & ia->ia_subnetmask;
543 	in_socktrim(&ia->ia_sockmask);
544 
545 	if (ifp->if_flags & IFF_BROADCAST) {
546 		if (broadaddr->sin_len != 0) {
547 			ia->ia_broadaddr = *broadaddr;
548 		} else if (ia->ia_subnetmask == IN_RFC3021_MASK) {
549 			ia->ia_broadaddr.sin_addr.s_addr = INADDR_BROADCAST;
550 			ia->ia_broadaddr.sin_len = sizeof(struct sockaddr_in);
551 			ia->ia_broadaddr.sin_family = AF_INET;
552 		} else {
553 			ia->ia_broadaddr.sin_addr.s_addr =
554 			    htonl(ia->ia_subnet | ~ia->ia_subnetmask);
555 			ia->ia_broadaddr.sin_len = sizeof(struct sockaddr_in);
556 			ia->ia_broadaddr.sin_family = AF_INET;
557 		}
558 	}
559 
560 	if (ifp->if_flags & IFF_POINTOPOINT)
561 		ia->ia_dstaddr = *dstaddr;
562 
563 	if (vhid != 0) {
564 		error = (*carp_attach_p)(&ia->ia_ifa, vhid);
565 		if (error)
566 			return (error);
567 	}
568 
569 	/* if_addrhead is already referenced by ifa_alloc() */
570 	IF_ADDR_WLOCK(ifp);
571 	CK_STAILQ_INSERT_TAIL(&ifp->if_addrhead, ifa, ifa_link);
572 	IF_ADDR_WUNLOCK(ifp);
573 
574 	ifa_ref(ifa);			/* in_ifaddrhead */
575 	sx_assert(&in_control_sx, SA_XLOCKED);
576 	CK_STAILQ_INSERT_TAIL(&V_in_ifaddrhead, ia, ia_link);
577 	CK_LIST_INSERT_HEAD(INADDR_HASH(ia->ia_addr.sin_addr.s_addr), ia,
578 	    ia_hash);
579 
580 	/*
581 	 * Give the interface a chance to initialize
582 	 * if this is its first address,
583 	 * and to validate the address if necessary.
584 	 */
585 	if (ifp->if_ioctl != NULL) {
586 		error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia);
587 		if (error)
588 			goto fail1;
589 	}
590 
591 	/*
592 	 * Add route for the network.
593 	 */
594 	if (vhid == 0) {
595 		error = in_addprefix(ia);
596 		if (error)
597 			goto fail1;
598 	}
599 
600 	/*
601 	 * Add a loopback route to self.
602 	 */
603 	if (vhid == 0 && ia_need_loopback_route(ia)) {
604 		struct in_ifaddr *eia;
605 
606 		eia = in_localip_more(ia);
607 
608 		if (eia == NULL) {
609 			error = ifa_add_loopback_route((struct ifaddr *)ia,
610 			    (struct sockaddr *)&ia->ia_addr);
611 			if (error)
612 				goto fail2;
613 		} else
614 			ifa_free(&eia->ia_ifa);
615 	}
616 
617 	if (iaIsFirst && (ifp->if_flags & IFF_MULTICAST)) {
618 		struct in_addr allhosts_addr;
619 		struct in_ifinfo *ii;
620 
621 		ii = ((struct in_ifinfo *)ifp->if_afdata[AF_INET]);
622 		allhosts_addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
623 
624 		error = in_joingroup(ifp, &allhosts_addr, NULL,
625 			&ii->ii_allhosts);
626 	}
627 
628 	/*
629 	 * Note: we don't need extra reference for ifa, since we called
630 	 * with sx lock held, and ifaddr can not be deleted in concurrent
631 	 * thread.
632 	 */
633 	EVENTHANDLER_INVOKE(ifaddr_event_ext, ifp, ifa, IFADDR_EVENT_ADD);
634 
635 	return (error);
636 
637 fail2:
638 	if (vhid == 0)
639 		(void )in_scrubprefix(ia, LLE_STATIC);
640 
641 fail1:
642 	if (ia->ia_ifa.ifa_carp)
643 		(*carp_detach_p)(&ia->ia_ifa, false);
644 
645 	IF_ADDR_WLOCK(ifp);
646 	CK_STAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifaddr, ifa_link);
647 	IF_ADDR_WUNLOCK(ifp);
648 	ifa_free(&ia->ia_ifa);		/* if_addrhead */
649 
650 	sx_assert(&in_control_sx, SA_XLOCKED);
651 	CK_STAILQ_REMOVE(&V_in_ifaddrhead, ia, in_ifaddr, ia_link);
652 	CK_LIST_REMOVE(ia, ia_hash);
653 	ifa_free(&ia->ia_ifa);		/* in_ifaddrhead */
654 
655 	return (error);
656 }
657 
658 static int
659 in_difaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct ucred *cred)
660 {
661 	const struct ifreq *ifr = (struct ifreq *)data;
662 	const struct sockaddr_in *addr = (const struct sockaddr_in *)
663 	    &ifr->ifr_addr;
664 	struct ifaddr *ifa;
665 	struct in_ifaddr *ia;
666 	bool deleteAny, iaIsLast;
667 	int error;
668 
669 	if (cred != NULL) {
670 		error = priv_check_cred(cred, PRIV_NET_DELIFADDR);
671 		if (error)
672 			return (error);
673 	}
674 
675 	if (addr->sin_len != sizeof(struct sockaddr_in) ||
676 	    addr->sin_family != AF_INET)
677 		deleteAny = true;
678 	else
679 		deleteAny = false;
680 
681 	iaIsLast = true;
682 	ia = NULL;
683 	IF_ADDR_WLOCK(ifp);
684 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
685 		struct in_ifaddr *it;
686 
687 		if (ifa->ifa_addr->sa_family != AF_INET)
688 			continue;
689 
690 		it = (struct in_ifaddr *)ifa;
691 		if (deleteAny && ia == NULL && (cred == NULL ||
692 		    prison_check_ip4(cred, &it->ia_addr.sin_addr) == 0))
693 			ia = it;
694 
695 		if (it->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr &&
696 		    (cred == NULL || prison_check_ip4(cred,
697 		    &addr->sin_addr) == 0))
698 			ia = it;
699 
700 		if (it != ia)
701 			iaIsLast = false;
702 	}
703 
704 	if (ia == NULL) {
705 		IF_ADDR_WUNLOCK(ifp);
706 		return (EADDRNOTAVAIL);
707 	}
708 
709 	CK_STAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifaddr, ifa_link);
710 	IF_ADDR_WUNLOCK(ifp);
711 	ifa_free(&ia->ia_ifa);		/* if_addrhead */
712 
713 	sx_assert(&in_control_sx, SA_XLOCKED);
714 	CK_STAILQ_REMOVE(&V_in_ifaddrhead, ia, in_ifaddr, ia_link);
715 	CK_LIST_REMOVE(ia, ia_hash);
716 
717 	/*
718 	 * in_scrubprefix() kills the interface route.
719 	 */
720 	in_scrubprefix(ia, LLE_STATIC);
721 
722 	/*
723 	 * in_ifadown gets rid of all the rest of
724 	 * the routes.  This is not quite the right
725 	 * thing to do, but at least if we are running
726 	 * a routing process they will come back.
727 	 */
728 	in_ifadown(&ia->ia_ifa, 1);
729 
730 	if (ia->ia_ifa.ifa_carp)
731 		(*carp_detach_p)(&ia->ia_ifa, cmd == SIOCAIFADDR);
732 
733 	/*
734 	 * If this is the last IPv4 address configured on this
735 	 * interface, leave the all-hosts group.
736 	 * No state-change report need be transmitted.
737 	 */
738 	if (iaIsLast && (ifp->if_flags & IFF_MULTICAST)) {
739 		struct in_ifinfo *ii;
740 
741 		ii = ((struct in_ifinfo *)ifp->if_afdata[AF_INET]);
742 		if (ii->ii_allhosts) {
743 			(void)in_leavegroup(ii->ii_allhosts, NULL);
744 			ii->ii_allhosts = NULL;
745 		}
746 	}
747 
748 	IF_ADDR_WLOCK(ifp);
749 	if (callout_stop(&ia->ia_garp_timer) == 1) {
750 		ifa_free(&ia->ia_ifa);
751 	}
752 	IF_ADDR_WUNLOCK(ifp);
753 
754 	EVENTHANDLER_INVOKE(ifaddr_event_ext, ifp, &ia->ia_ifa,
755 	    IFADDR_EVENT_DEL);
756 	ifa_free(&ia->ia_ifa);		/* in_ifaddrhead */
757 
758 	return (0);
759 }
760 
761 static int
762 in_gifaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct ucred *cred)
763 {
764 	struct in_aliasreq *ifra = (struct in_aliasreq *)data;
765 	const struct sockaddr_in *addr = &ifra->ifra_addr;
766 	struct epoch_tracker et;
767 	struct ifaddr *ifa;
768 	struct in_ifaddr *ia;
769 
770 	/*
771 	 * ifra_addr must be present and be of INET family.
772 	 */
773 	if (addr->sin_len != sizeof(struct sockaddr_in) ||
774 	    addr->sin_family != AF_INET)
775 		return (EINVAL);
776 
777 	/*
778 	 * See whether address exist.
779 	 */
780 	ia = NULL;
781 	NET_EPOCH_ENTER(et);
782 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
783 		struct in_ifaddr *it;
784 
785 		if (ifa->ifa_addr->sa_family != AF_INET)
786 			continue;
787 
788 		it = (struct in_ifaddr *)ifa;
789 		if (it->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr &&
790 		    prison_check_ip4(cred, &addr->sin_addr) == 0) {
791 			ia = it;
792 			break;
793 		}
794 	}
795 	if (ia == NULL) {
796 		NET_EPOCH_EXIT(et);
797 		return (EADDRNOTAVAIL);
798 	}
799 
800 	ifra->ifra_mask = ia->ia_sockmask;
801 	if ((ifp->if_flags & IFF_POINTOPOINT) &&
802 	    ia->ia_dstaddr.sin_family == AF_INET)
803 		ifra->ifra_dstaddr = ia->ia_dstaddr;
804 	else if ((ifp->if_flags & IFF_BROADCAST) &&
805 	    ia->ia_broadaddr.sin_family == AF_INET)
806 		ifra->ifra_broadaddr = ia->ia_broadaddr;
807 	else
808 		memset(&ifra->ifra_broadaddr, 0,
809 		    sizeof(ifra->ifra_broadaddr));
810 
811 	NET_EPOCH_EXIT(et);
812 	return (0);
813 }
814 
815 static int
816 in_match_ifaddr(const struct rtentry *rt, const struct nhop_object *nh, void *arg)
817 {
818 
819 	if (nh->nh_ifa == (struct ifaddr *)arg)
820 		return (1);
821 
822 	return (0);
823 }
824 
825 static int
826 in_handle_prefix_route(uint32_t fibnum, int cmd,
827     struct sockaddr_in *dst, struct sockaddr_in *netmask, struct ifaddr *ifa,
828     struct ifnet *ifp)
829 {
830 
831 	NET_EPOCH_ASSERT();
832 
833 	/* Prepare gateway */
834 	struct sockaddr_dl_short sdl = {
835 		.sdl_family = AF_LINK,
836 		.sdl_len = sizeof(struct sockaddr_dl_short),
837 		.sdl_type = ifa->ifa_ifp->if_type,
838 		.sdl_index = ifa->ifa_ifp->if_index,
839 	};
840 
841 	struct rt_addrinfo info = {
842 		.rti_ifa = ifa,
843 		.rti_ifp = ifp,
844 		.rti_flags = RTF_PINNED | ((netmask != NULL) ? 0 : RTF_HOST),
845 		.rti_info = {
846 			[RTAX_DST] = (struct sockaddr *)dst,
847 			[RTAX_NETMASK] = (struct sockaddr *)netmask,
848 			[RTAX_GATEWAY] = (struct sockaddr *)&sdl,
849 		},
850 		/* Ensure we delete the prefix IFF prefix ifa matches */
851 		.rti_filter = in_match_ifaddr,
852 		.rti_filterdata = ifa,
853 	};
854 
855 	return (rib_handle_ifaddr_info(fibnum, cmd, &info));
856 }
857 
858 /*
859  * Routing table interaction with interface addresses.
860  *
861  * In general, two types of routes needs to be installed:
862  * a) "interface" or "prefix" route, telling user that the addresses
863  *   behind the ifa prefix are reached directly.
864  * b) "loopback" route installed for the ifa address, telling user that
865  *   the address belongs to local system.
866  *
867  * Handling for (a) and (b) differs in multi-fib aspects, hence they
868  *  are implemented in different functions below.
869  *
870  * The cases above may intersect - /32 interface aliases results in
871  *  the same prefix produced by (a) and (b). This blurs the definition
872  *  of the "loopback" route and complicate interactions. The interaction
873  *  table is defined below. The case numbers are used in the multiple
874  *  functions below to refer to the particular test case.
875  *
876  * There can be multiple options:
877  * 1) Adding address with prefix on non-p2p/non-loopback interface.
878  *  Example: 192.0.2.1/24. Action:
879  *  * add "prefix" route towards 192.0.2.0/24 via @ia interface,
880  *    using @ia as an address source.
881  *  * add "loopback" route towards 192.0.2.1 via V_loif, saving
882  *   @ia ifp in the gateway and using @ia as an address source.
883  *
884  * 2) Adding address with /32 mask to non-p2p/non-loopback interface.
885  *  Example: 192.0.2.2/32. Action:
886  *  * add "prefix" host route via V_loif, using @ia as an address source.
887  *
888  * 3) Adding address with or without prefix to p2p interface.
889  *  Example: 10.0.0.1/24->10.0.0.2. Action:
890  *  * add "prefix" host route towards 10.0.0.2 via this interface, using @ia
891  *    as an address source. Note: no sense in installing full /24 as the interface
892  *    is point-to-point.
893  *  * add "loopback" route towards 10.0.9.1 via V_loif, saving
894  *   @ia ifp in the gateway and using @ia as an address source.
895  *
896  * 4) Adding address with or without prefix to loopback interface.
897  *  Example: 192.0.2.1/24. Action:
898  *  * add "prefix" host route via @ia interface, using @ia as an address source.
899  *    Note: Skip installing /24 prefix as it would introduce TTL loop
900  *    for the traffic destined to these addresses.
901  */
902 
903 /*
904  * Checks if @ia needs to install loopback route to @ia address via
905  *  ifa_maintain_loopback_route().
906  *
907  * Return true on success.
908  */
909 static bool
910 ia_need_loopback_route(const struct in_ifaddr *ia)
911 {
912 	struct ifnet *ifp = ia->ia_ifp;
913 
914 	/* Case 4: Skip loopback interfaces */
915 	if ((ifp->if_flags & IFF_LOOPBACK) ||
916 	    (ia->ia_addr.sin_addr.s_addr == INADDR_ANY))
917 		return (false);
918 
919 	/* Clash avoidance: Skip p2p interfaces with both addresses are equal */
920 	if ((ifp->if_flags & IFF_POINTOPOINT) &&
921 	    ia->ia_dstaddr.sin_addr.s_addr == ia->ia_addr.sin_addr.s_addr)
922 		return (false);
923 
924 	/* Case 2: skip /32 prefixes */
925 	if (!(ifp->if_flags & IFF_POINTOPOINT) &&
926 	    (ia->ia_sockmask.sin_addr.s_addr == INADDR_BROADCAST))
927 		return (false);
928 
929 	return (true);
930 }
931 
932 /*
933  * Calculate "prefix" route corresponding to @ia.
934  */
935 static void
936 ia_getrtprefix(const struct in_ifaddr *ia, struct in_addr *prefix, struct in_addr *mask)
937 {
938 
939 	if (ia->ia_ifp->if_flags & IFF_POINTOPOINT) {
940 		/* Case 3: return host route for dstaddr */
941 		*prefix = ia->ia_dstaddr.sin_addr;
942 		mask->s_addr = INADDR_BROADCAST;
943 	} else if (ia->ia_ifp->if_flags & IFF_LOOPBACK) {
944 		/* Case 4: return host route for ifaddr */
945 		*prefix = ia->ia_addr.sin_addr;
946 		mask->s_addr = INADDR_BROADCAST;
947 	} else {
948 		/* Cases 1,2: return actual ia prefix */
949 		*prefix = ia->ia_addr.sin_addr;
950 		*mask = ia->ia_sockmask.sin_addr;
951 		prefix->s_addr &= mask->s_addr;
952 	}
953 }
954 
955 /*
956  * Adds or delete interface "prefix" route corresponding to @ifa.
957  *  Returns 0 on success or errno.
958  */
959 static int
960 in_handle_ifaddr_route(int cmd, struct in_ifaddr *ia)
961 {
962 	struct ifaddr *ifa = &ia->ia_ifa;
963 	struct in_addr daddr, maddr;
964 	struct sockaddr_in *pmask;
965 	struct epoch_tracker et;
966 	int error;
967 
968 	ia_getrtprefix(ia, &daddr, &maddr);
969 
970 	struct sockaddr_in mask = {
971 		.sin_family = AF_INET,
972 		.sin_len = sizeof(struct sockaddr_in),
973 		.sin_addr = maddr,
974 	};
975 
976 	pmask = (maddr.s_addr != INADDR_BROADCAST) ? &mask : NULL;
977 
978 	struct sockaddr_in dst = {
979 		.sin_family = AF_INET,
980 		.sin_len = sizeof(struct sockaddr_in),
981 		.sin_addr.s_addr = daddr.s_addr & maddr.s_addr,
982 	};
983 
984 	struct ifnet *ifp = ia->ia_ifp;
985 
986 	if ((maddr.s_addr == INADDR_BROADCAST) &&
987 	    (!(ia->ia_ifp->if_flags & (IFF_POINTOPOINT|IFF_LOOPBACK)))) {
988 		/* Case 2: host route on broadcast interface */
989 		ifp = V_loif;
990 	}
991 
992 	uint32_t fibnum = ifa->ifa_ifp->if_fib;
993 	NET_EPOCH_ENTER(et);
994 	error = in_handle_prefix_route(fibnum, cmd, &dst, pmask, ifa, ifp);
995 	NET_EPOCH_EXIT(et);
996 
997 	return (error);
998 }
999 
1000 /*
1001  * Check if we have a route for the given prefix already.
1002  */
1003 static bool
1004 in_hasrtprefix(struct in_ifaddr *target)
1005 {
1006 	struct epoch_tracker et;
1007 	struct in_ifaddr *ia;
1008 	struct in_addr prefix, mask, p, m;
1009 	bool result = false;
1010 
1011 	ia_getrtprefix(target, &prefix, &mask);
1012 
1013 	/* Look for an existing address with the same prefix, mask, and fib */
1014 	NET_EPOCH_ENTER(et);
1015 	CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
1016 		ia_getrtprefix(ia, &p, &m);
1017 
1018 		if (prefix.s_addr != p.s_addr ||
1019 		    mask.s_addr != m.s_addr)
1020 			continue;
1021 
1022 		if (target->ia_ifp->if_fib != ia->ia_ifp->if_fib)
1023 			continue;
1024 
1025 		/*
1026 		 * If we got a matching prefix route inserted by other
1027 		 * interface address, we are done here.
1028 		 */
1029 		if (ia->ia_flags & IFA_ROUTE) {
1030 			result = true;
1031 			break;
1032 		}
1033 	}
1034 	NET_EPOCH_EXIT(et);
1035 
1036 	return (result);
1037 }
1038 
1039 int
1040 in_addprefix(struct in_ifaddr *target)
1041 {
1042 	int error;
1043 
1044 	if (in_hasrtprefix(target)) {
1045 		if (V_nosameprefix)
1046 			return (EEXIST);
1047 		else {
1048 			rt_addrmsg(RTM_ADD, &target->ia_ifa,
1049 			    target->ia_ifp->if_fib);
1050 			return (0);
1051 		}
1052 	}
1053 
1054 	/*
1055 	 * No-one seem to have this prefix route, so we try to insert it.
1056 	 */
1057 	rt_addrmsg(RTM_ADD, &target->ia_ifa, target->ia_ifp->if_fib);
1058 	error = in_handle_ifaddr_route(RTM_ADD, target);
1059 	if (!error)
1060 		target->ia_flags |= IFA_ROUTE;
1061 	return (error);
1062 }
1063 
1064 /*
1065  * Removes either all lle entries for given @ia, or lle
1066  * corresponding to @ia address.
1067  */
1068 static void
1069 in_scrubprefixlle(struct in_ifaddr *ia, int all, u_int flags)
1070 {
1071 	struct sockaddr_in addr, mask;
1072 	struct sockaddr *saddr, *smask;
1073 	struct ifnet *ifp;
1074 
1075 	saddr = (struct sockaddr *)&addr;
1076 	bzero(&addr, sizeof(addr));
1077 	addr.sin_len = sizeof(addr);
1078 	addr.sin_family = AF_INET;
1079 	smask = (struct sockaddr *)&mask;
1080 	bzero(&mask, sizeof(mask));
1081 	mask.sin_len = sizeof(mask);
1082 	mask.sin_family = AF_INET;
1083 	mask.sin_addr.s_addr = ia->ia_subnetmask;
1084 	ifp = ia->ia_ifp;
1085 
1086 	if (all) {
1087 		/*
1088 		 * Remove all L2 entries matching given prefix.
1089 		 * Convert address to host representation to avoid
1090 		 * doing this on every callback. ia_subnetmask is already
1091 		 * stored in host representation.
1092 		 */
1093 		addr.sin_addr.s_addr = ntohl(ia->ia_addr.sin_addr.s_addr);
1094 		lltable_prefix_free(AF_INET, saddr, smask, flags);
1095 	} else {
1096 		/* Remove interface address only */
1097 		addr.sin_addr.s_addr = ia->ia_addr.sin_addr.s_addr;
1098 		lltable_delete_addr(LLTABLE(ifp), LLE_IFADDR, saddr);
1099 	}
1100 }
1101 
1102 /*
1103  * If there is no other address in the system that can serve a route to the
1104  * same prefix, remove the route.  Hand over the route to the new address
1105  * otherwise.
1106  */
1107 int
1108 in_scrubprefix(struct in_ifaddr *target, u_int flags)
1109 {
1110 	struct epoch_tracker et;
1111 	struct in_ifaddr *ia;
1112 	struct in_addr prefix, mask, p, m;
1113 	int error = 0;
1114 
1115 	/*
1116 	 * Remove the loopback route to the interface address.
1117 	 */
1118 	if (ia_need_loopback_route(target) && (flags & LLE_STATIC)) {
1119 		struct in_ifaddr *eia;
1120 
1121 		eia = in_localip_more(target);
1122 
1123 		if (eia != NULL) {
1124 			error = ifa_switch_loopback_route((struct ifaddr *)eia,
1125 			    (struct sockaddr *)&target->ia_addr);
1126 			ifa_free(&eia->ia_ifa);
1127 		} else {
1128 			error = ifa_del_loopback_route((struct ifaddr *)target,
1129 			    (struct sockaddr *)&target->ia_addr);
1130 		}
1131 	}
1132 
1133 	ia_getrtprefix(target, &prefix, &mask);
1134 
1135 	if ((target->ia_flags & IFA_ROUTE) == 0) {
1136 		rt_addrmsg(RTM_DELETE, &target->ia_ifa, target->ia_ifp->if_fib);
1137 
1138 		/*
1139 		 * Removing address from !IFF_UP interface or
1140 		 * prefix which exists on other interface (along with route).
1141 		 * No entries should exist here except target addr.
1142 		 * Given that, delete this entry only.
1143 		 */
1144 		in_scrubprefixlle(target, 0, flags);
1145 		return (0);
1146 	}
1147 
1148 	NET_EPOCH_ENTER(et);
1149 	CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
1150 		ia_getrtprefix(ia, &p, &m);
1151 
1152 		if (prefix.s_addr != p.s_addr ||
1153 		    mask.s_addr != m.s_addr)
1154 			continue;
1155 
1156 		if ((ia->ia_ifp->if_flags & IFF_UP) == 0)
1157 			continue;
1158 
1159 		/*
1160 		 * If we got a matching prefix address, move IFA_ROUTE and
1161 		 * the route itself to it.  Make sure that routing daemons
1162 		 * get a heads-up.
1163 		 */
1164 		if ((ia->ia_flags & IFA_ROUTE) == 0) {
1165 			ifa_ref(&ia->ia_ifa);
1166 			NET_EPOCH_EXIT(et);
1167 			error = in_handle_ifaddr_route(RTM_DELETE, target);
1168 			if (error == 0)
1169 				target->ia_flags &= ~IFA_ROUTE;
1170 			else
1171 				log(LOG_INFO, "in_scrubprefix: err=%d, old prefix delete failed\n",
1172 					error);
1173 			/* Scrub all entries IFF interface is different */
1174 			in_scrubprefixlle(target, target->ia_ifp != ia->ia_ifp,
1175 			    flags);
1176 			error = in_handle_ifaddr_route(RTM_ADD, ia);
1177 			if (error == 0)
1178 				ia->ia_flags |= IFA_ROUTE;
1179 			else
1180 				log(LOG_INFO, "in_scrubprefix: err=%d, new prefix add failed\n",
1181 					error);
1182 			ifa_free(&ia->ia_ifa);
1183 			return (error);
1184 		}
1185 	}
1186 	NET_EPOCH_EXIT(et);
1187 
1188 	/*
1189 	 * remove all L2 entries on the given prefix
1190 	 */
1191 	in_scrubprefixlle(target, 1, flags);
1192 
1193 	/*
1194 	 * As no-one seem to have this prefix, we can remove the route.
1195 	 */
1196 	rt_addrmsg(RTM_DELETE, &target->ia_ifa, target->ia_ifp->if_fib);
1197 	error = in_handle_ifaddr_route(RTM_DELETE, target);
1198 	if (error == 0)
1199 		target->ia_flags &= ~IFA_ROUTE;
1200 	else
1201 		log(LOG_INFO, "in_scrubprefix: err=%d, prefix delete failed\n", error);
1202 	return (error);
1203 }
1204 
1205 void
1206 in_ifscrub_all(void)
1207 {
1208 	struct ifnet *ifp;
1209 	struct ifaddr *ifa, *nifa;
1210 	struct ifaliasreq ifr;
1211 
1212 	IFNET_RLOCK();
1213 	CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
1214 		/* Cannot lock here - lock recursion. */
1215 		/* NET_EPOCH_ENTER(et); */
1216 		CK_STAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, nifa) {
1217 			if (ifa->ifa_addr->sa_family != AF_INET)
1218 				continue;
1219 
1220 			/*
1221 			 * This is ugly but the only way for legacy IP to
1222 			 * cleanly remove addresses and everything attached.
1223 			 */
1224 			bzero(&ifr, sizeof(ifr));
1225 			ifr.ifra_addr = *ifa->ifa_addr;
1226 			if (ifa->ifa_dstaddr)
1227 			ifr.ifra_broadaddr = *ifa->ifa_dstaddr;
1228 			(void)in_control(NULL, SIOCDIFADDR, (caddr_t)&ifr,
1229 			    ifp, NULL);
1230 		}
1231 		/* NET_EPOCH_EXIT(et); */
1232 		in_purgemaddrs(ifp);
1233 		igmp_domifdetach(ifp);
1234 	}
1235 	IFNET_RUNLOCK();
1236 }
1237 
1238 int
1239 in_ifaddr_broadcast(struct in_addr in, struct in_ifaddr *ia)
1240 {
1241 
1242 	return ((in.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
1243 	     /*
1244 	      * Optionally check for old-style (host 0) broadcast, but
1245 	      * taking into account that RFC 3021 obsoletes it.
1246 	      */
1247 	    (V_broadcast_lowest && ia->ia_subnetmask != IN_RFC3021_MASK &&
1248 	    ntohl(in.s_addr) == ia->ia_subnet)) &&
1249 	     /*
1250 	      * Check for an all one subnetmask. These
1251 	      * only exist when an interface gets a secondary
1252 	      * address.
1253 	      */
1254 	    ia->ia_subnetmask != (u_long)0xffffffff);
1255 }
1256 
1257 /*
1258  * Return 1 if the address might be a local broadcast address.
1259  */
1260 int
1261 in_broadcast(struct in_addr in, struct ifnet *ifp)
1262 {
1263 	struct ifaddr *ifa;
1264 	int found;
1265 
1266 	NET_EPOCH_ASSERT();
1267 
1268 	if (in.s_addr == INADDR_BROADCAST ||
1269 	    in.s_addr == INADDR_ANY)
1270 		return (1);
1271 	if ((ifp->if_flags & IFF_BROADCAST) == 0)
1272 		return (0);
1273 	found = 0;
1274 	/*
1275 	 * Look through the list of addresses for a match
1276 	 * with a broadcast address.
1277 	 */
1278 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
1279 		if (ifa->ifa_addr->sa_family == AF_INET &&
1280 		    in_ifaddr_broadcast(in, (struct in_ifaddr *)ifa)) {
1281 			found = 1;
1282 			break;
1283 		}
1284 	return (found);
1285 }
1286 
1287 /*
1288  * On interface removal, clean up IPv4 data structures hung off of the ifnet.
1289  */
1290 void
1291 in_ifdetach(struct ifnet *ifp)
1292 {
1293 	IN_MULTI_LOCK();
1294 	in_pcbpurgeif0(&V_ripcbinfo, ifp);
1295 	in_pcbpurgeif0(&V_udbinfo, ifp);
1296 	in_pcbpurgeif0(&V_ulitecbinfo, ifp);
1297 	in_purgemaddrs(ifp);
1298 	IN_MULTI_UNLOCK();
1299 
1300 	/*
1301 	 * Make sure all multicast deletions invoking if_ioctl() are
1302 	 * completed before returning. Else we risk accessing a freed
1303 	 * ifnet structure pointer.
1304 	 */
1305 	inm_release_wait(NULL);
1306 }
1307 
1308 static void
1309 in_ifnet_event(void *arg __unused, struct ifnet *ifp, int event)
1310 {
1311 	struct epoch_tracker et;
1312 	struct ifaddr *ifa;
1313 	struct in_ifaddr *ia;
1314 	int error;
1315 
1316 	NET_EPOCH_ENTER(et);
1317 	switch (event) {
1318 	case IFNET_EVENT_DOWN:
1319 		CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1320 			if (ifa->ifa_addr->sa_family != AF_INET)
1321 				continue;
1322 			ia = (struct in_ifaddr *)ifa;
1323 			if ((ia->ia_flags & IFA_ROUTE) == 0)
1324 				continue;
1325 			ifa_ref(ifa);
1326 			/*
1327 			 * in_scrubprefix() kills the interface route.
1328 			 */
1329 			in_scrubprefix(ia, 0);
1330 			/*
1331 			 * in_ifadown gets rid of all the rest of the
1332 			 * routes.  This is not quite the right thing
1333 			 * to do, but at least if we are running a
1334 			 * routing process they will come back.
1335 			 */
1336 			in_ifadown(ifa, 0);
1337 			ifa_free(ifa);
1338 		}
1339 		break;
1340 
1341 	case IFNET_EVENT_UP:
1342 		CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1343 			if (ifa->ifa_addr->sa_family != AF_INET)
1344 				continue;
1345 			ia = (struct in_ifaddr *)ifa;
1346 			if (ia->ia_flags & IFA_ROUTE)
1347 				continue;
1348 			ifa_ref(ifa);
1349 			error = ifa_del_loopback_route(ifa, ifa->ifa_addr);
1350 			rt_addrmsg(RTM_ADD, ifa, ifa->ifa_ifp->if_fib);
1351 			error = in_handle_ifaddr_route(RTM_ADD, ia);
1352 			if (error == 0)
1353 				ia->ia_flags |= IFA_ROUTE;
1354 			error = ifa_add_loopback_route(ifa, ifa->ifa_addr);
1355 			ifa_free(ifa);
1356 		}
1357 		break;
1358 	}
1359 	NET_EPOCH_EXIT(et);
1360 }
1361 EVENTHANDLER_DEFINE(ifnet_event, in_ifnet_event, NULL, EVENTHANDLER_PRI_ANY);
1362 
1363 /*
1364  * Delete all IPv4 multicast address records, and associated link-layer
1365  * multicast address records, associated with ifp.
1366  * XXX It looks like domifdetach runs AFTER the link layer cleanup.
1367  * XXX This should not race with ifma_protospec being set during
1368  * a new allocation, if it does, we have bigger problems.
1369  */
1370 static void
1371 in_purgemaddrs(struct ifnet *ifp)
1372 {
1373 	struct epoch_tracker	 et;
1374 	struct in_multi_head purgeinms;
1375 	struct in_multi		*inm;
1376 	struct ifmultiaddr	*ifma;
1377 
1378 	SLIST_INIT(&purgeinms);
1379 	IN_MULTI_LIST_LOCK();
1380 
1381 	/*
1382 	 * Extract list of in_multi associated with the detaching ifp
1383 	 * which the PF_INET layer is about to release.
1384 	 * We need to do this as IF_ADDR_LOCK() may be re-acquired
1385 	 * by code further down.
1386 	 */
1387 	IF_ADDR_WLOCK(ifp);
1388 	NET_EPOCH_ENTER(et);
1389 	CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
1390 		inm = inm_ifmultiaddr_get_inm(ifma);
1391 		if (inm == NULL)
1392 			continue;
1393 		inm_rele_locked(&purgeinms, inm);
1394 	}
1395 	NET_EPOCH_EXIT(et);
1396 	IF_ADDR_WUNLOCK(ifp);
1397 
1398 	inm_release_list_deferred(&purgeinms);
1399 	igmp_ifdetach(ifp);
1400 	IN_MULTI_LIST_UNLOCK();
1401 }
1402 
1403 struct in_llentry {
1404 	struct llentry		base;
1405 };
1406 
1407 #define	IN_LLTBL_DEFAULT_HSIZE	32
1408 #define	IN_LLTBL_HASH(k, h) \
1409 	(((((((k >> 8) ^ k) >> 8) ^ k) >> 8) ^ k) & ((h) - 1))
1410 
1411 /*
1412  * Do actual deallocation of @lle.
1413  */
1414 static void
1415 in_lltable_destroy_lle_unlocked(epoch_context_t ctx)
1416 {
1417 	struct llentry *lle;
1418 
1419 	lle = __containerof(ctx, struct llentry, lle_epoch_ctx);
1420 	LLE_LOCK_DESTROY(lle);
1421 	LLE_REQ_DESTROY(lle);
1422 	free(lle, M_LLTABLE);
1423 }
1424 
1425 /*
1426  * Called by LLE_FREE_LOCKED when number of references
1427  * drops to zero.
1428  */
1429 static void
1430 in_lltable_destroy_lle(struct llentry *lle)
1431 {
1432 
1433 	LLE_WUNLOCK(lle);
1434 	NET_EPOCH_CALL(in_lltable_destroy_lle_unlocked, &lle->lle_epoch_ctx);
1435 }
1436 
1437 static struct llentry *
1438 in_lltable_new(struct in_addr addr4, u_int flags)
1439 {
1440 	struct in_llentry *lle;
1441 
1442 	lle = malloc(sizeof(struct in_llentry), M_LLTABLE, M_NOWAIT | M_ZERO);
1443 	if (lle == NULL)		/* NB: caller generates msg */
1444 		return NULL;
1445 
1446 	/*
1447 	 * For IPv4 this will trigger "arpresolve" to generate
1448 	 * an ARP request.
1449 	 */
1450 	lle->base.la_expire = time_uptime; /* mark expired */
1451 	lle->base.r_l3addr.addr4 = addr4;
1452 	lle->base.lle_refcnt = 1;
1453 	lle->base.lle_free = in_lltable_destroy_lle;
1454 	LLE_LOCK_INIT(&lle->base);
1455 	LLE_REQ_INIT(&lle->base);
1456 	callout_init(&lle->base.lle_timer, 1);
1457 
1458 	return (&lle->base);
1459 }
1460 
1461 #define IN_ARE_MASKED_ADDR_EQUAL(d, a, m)	(		\
1462 	((((d).s_addr ^ (a).s_addr) & (m).s_addr)) == 0 )
1463 
1464 static int
1465 in_lltable_match_prefix(const struct sockaddr *saddr,
1466     const struct sockaddr *smask, u_int flags, struct llentry *lle)
1467 {
1468 	struct in_addr addr, mask, lle_addr;
1469 
1470 	addr = ((const struct sockaddr_in *)saddr)->sin_addr;
1471 	mask = ((const struct sockaddr_in *)smask)->sin_addr;
1472 	lle_addr.s_addr = ntohl(lle->r_l3addr.addr4.s_addr);
1473 
1474 	if (IN_ARE_MASKED_ADDR_EQUAL(lle_addr, addr, mask) == 0)
1475 		return (0);
1476 
1477 	if (lle->la_flags & LLE_IFADDR) {
1478 		/*
1479 		 * Delete LLE_IFADDR records IFF address & flag matches.
1480 		 * Note that addr is the interface address within prefix
1481 		 * being matched.
1482 		 * Note also we should handle 'ifdown' cases without removing
1483 		 * ifaddr macs.
1484 		 */
1485 		if (addr.s_addr == lle_addr.s_addr && (flags & LLE_STATIC) != 0)
1486 			return (1);
1487 		return (0);
1488 	}
1489 
1490 	/* flags & LLE_STATIC means deleting both dynamic and static entries */
1491 	if ((flags & LLE_STATIC) || !(lle->la_flags & LLE_STATIC))
1492 		return (1);
1493 
1494 	return (0);
1495 }
1496 
1497 static void
1498 in_lltable_free_entry(struct lltable *llt, struct llentry *lle)
1499 {
1500 	size_t pkts_dropped;
1501 
1502 	LLE_WLOCK_ASSERT(lle);
1503 	KASSERT(llt != NULL, ("lltable is NULL"));
1504 
1505 	/* Unlink entry from table if not already */
1506 	if ((lle->la_flags & LLE_LINKED) != 0) {
1507 		IF_AFDATA_WLOCK_ASSERT(llt->llt_ifp);
1508 		lltable_unlink_entry(llt, lle);
1509 	}
1510 
1511 	/* Drop hold queue */
1512 	pkts_dropped = llentry_free(lle);
1513 	ARPSTAT_ADD(dropped, pkts_dropped);
1514 }
1515 
1516 static int
1517 in_lltable_rtcheck(struct ifnet *ifp, u_int flags, const struct sockaddr *l3addr)
1518 {
1519 	struct nhop_object *nh;
1520 	struct in_addr addr;
1521 
1522 	KASSERT(l3addr->sa_family == AF_INET,
1523 	    ("sin_family %d", l3addr->sa_family));
1524 
1525 	addr = ((const struct sockaddr_in *)l3addr)->sin_addr;
1526 
1527 	nh = fib4_lookup(ifp->if_fib, addr, 0, NHR_NONE, 0);
1528 	if (nh == NULL)
1529 		return (EINVAL);
1530 
1531 	/*
1532 	 * If the gateway for an existing host route matches the target L3
1533 	 * address, which is a special route inserted by some implementation
1534 	 * such as MANET, and the interface is of the correct type, then
1535 	 * allow for ARP to proceed.
1536 	 */
1537 	if (nh->nh_flags & NHF_GATEWAY) {
1538 		if (!(nh->nh_flags & NHF_HOST) || nh->nh_ifp->if_type != IFT_ETHER ||
1539 		    (nh->nh_ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) != 0 ||
1540 		    memcmp(nh->gw_sa.sa_data, l3addr->sa_data,
1541 		    sizeof(in_addr_t)) != 0) {
1542 			return (EINVAL);
1543 		}
1544 	}
1545 
1546 	/*
1547 	 * Make sure that at least the destination address is covered
1548 	 * by the route. This is for handling the case where 2 or more
1549 	 * interfaces have the same prefix. An incoming packet arrives
1550 	 * on one interface and the corresponding outgoing packet leaves
1551 	 * another interface.
1552 	 */
1553 	if ((nh->nh_ifp != ifp) && (nh->nh_flags & NHF_HOST) == 0) {
1554 		struct in_ifaddr *ia = (struct in_ifaddr *)ifaof_ifpforaddr(l3addr, ifp);
1555 		struct in_addr dst_addr, mask_addr;
1556 
1557 		if (ia == NULL)
1558 			return (EINVAL);
1559 
1560 		/*
1561 		 * ifaof_ifpforaddr() returns _best matching_ IFA.
1562 		 * It is possible that ifa prefix does not cover our address.
1563 		 * Explicitly verify and fail if that's the case.
1564 		 */
1565 		dst_addr = IA_SIN(ia)->sin_addr;
1566 		mask_addr.s_addr = htonl(ia->ia_subnetmask);
1567 
1568 		if (!IN_ARE_MASKED_ADDR_EQUAL(dst_addr, addr, mask_addr))
1569 			return (EINVAL);
1570 	}
1571 
1572 	return (0);
1573 }
1574 
1575 static inline uint32_t
1576 in_lltable_hash_dst(const struct in_addr dst, uint32_t hsize)
1577 {
1578 
1579 	return (IN_LLTBL_HASH(dst.s_addr, hsize));
1580 }
1581 
1582 static uint32_t
1583 in_lltable_hash(const struct llentry *lle, uint32_t hsize)
1584 {
1585 
1586 	return (in_lltable_hash_dst(lle->r_l3addr.addr4, hsize));
1587 }
1588 
1589 static void
1590 in_lltable_fill_sa_entry(const struct llentry *lle, struct sockaddr *sa)
1591 {
1592 	struct sockaddr_in *sin;
1593 
1594 	sin = (struct sockaddr_in *)sa;
1595 	bzero(sin, sizeof(*sin));
1596 	sin->sin_family = AF_INET;
1597 	sin->sin_len = sizeof(*sin);
1598 	sin->sin_addr = lle->r_l3addr.addr4;
1599 }
1600 
1601 static inline struct llentry *
1602 in_lltable_find_dst(struct lltable *llt, struct in_addr dst)
1603 {
1604 	struct llentry *lle;
1605 	struct llentries *lleh;
1606 	u_int hashidx;
1607 
1608 	hashidx = in_lltable_hash_dst(dst, llt->llt_hsize);
1609 	lleh = &llt->lle_head[hashidx];
1610 	CK_LIST_FOREACH(lle, lleh, lle_next) {
1611 		if (lle->la_flags & LLE_DELETED)
1612 			continue;
1613 		if (lle->r_l3addr.addr4.s_addr == dst.s_addr)
1614 			break;
1615 	}
1616 
1617 	return (lle);
1618 }
1619 
1620 static void
1621 in_lltable_delete_entry(struct lltable *llt, struct llentry *lle)
1622 {
1623 
1624 	lle->la_flags |= LLE_DELETED;
1625 	EVENTHANDLER_INVOKE(lle_event, lle, LLENTRY_DELETED);
1626 #ifdef DIAGNOSTIC
1627 	log(LOG_INFO, "ifaddr cache = %p is deleted\n", lle);
1628 #endif
1629 	llentry_free(lle);
1630 }
1631 
1632 static struct llentry *
1633 in_lltable_alloc(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
1634 {
1635 	const struct sockaddr_in *sin = (const struct sockaddr_in *)l3addr;
1636 	struct ifnet *ifp = llt->llt_ifp;
1637 	struct llentry *lle;
1638 	char linkhdr[LLE_MAX_LINKHDR];
1639 	size_t linkhdrsize;
1640 	int lladdr_off;
1641 
1642 	KASSERT(l3addr->sa_family == AF_INET,
1643 	    ("sin_family %d", l3addr->sa_family));
1644 
1645 	/*
1646 	 * A route that covers the given address must have
1647 	 * been installed 1st because we are doing a resolution,
1648 	 * verify this.
1649 	 */
1650 	if (!(flags & LLE_IFADDR) &&
1651 	    in_lltable_rtcheck(ifp, flags, l3addr) != 0)
1652 		return (NULL);
1653 
1654 	lle = in_lltable_new(sin->sin_addr, flags);
1655 	if (lle == NULL) {
1656 		log(LOG_INFO, "lla_lookup: new lle malloc failed\n");
1657 		return (NULL);
1658 	}
1659 	lle->la_flags = flags;
1660 	if (flags & LLE_STATIC)
1661 		lle->r_flags |= RLLE_VALID;
1662 	if ((flags & LLE_IFADDR) == LLE_IFADDR) {
1663 		linkhdrsize = LLE_MAX_LINKHDR;
1664 		if (lltable_calc_llheader(ifp, AF_INET, IF_LLADDR(ifp),
1665 		    linkhdr, &linkhdrsize, &lladdr_off) != 0) {
1666 			in_lltable_free_entry(llt, lle);
1667 			return (NULL);
1668 		}
1669 		lltable_set_entry_addr(ifp, lle, linkhdr, linkhdrsize,
1670 		    lladdr_off);
1671 		lle->la_flags |= LLE_STATIC;
1672 		lle->r_flags |= (RLLE_VALID | RLLE_IFADDR);
1673 	}
1674 
1675 	return (lle);
1676 }
1677 
1678 /*
1679  * Return NULL if not found or marked for deletion.
1680  * If found return lle read locked.
1681  */
1682 static struct llentry *
1683 in_lltable_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
1684 {
1685 	const struct sockaddr_in *sin = (const struct sockaddr_in *)l3addr;
1686 	struct llentry *lle;
1687 
1688 	IF_AFDATA_LOCK_ASSERT(llt->llt_ifp);
1689 	KASSERT(l3addr->sa_family == AF_INET,
1690 	    ("sin_family %d", l3addr->sa_family));
1691 	KASSERT((flags & (LLE_UNLOCKED | LLE_EXCLUSIVE)) !=
1692 	    (LLE_UNLOCKED | LLE_EXCLUSIVE),
1693 	    ("wrong lle request flags: %#x", flags));
1694 
1695 	lle = in_lltable_find_dst(llt, sin->sin_addr);
1696 	if (lle == NULL)
1697 		return (NULL);
1698 	if (flags & LLE_UNLOCKED)
1699 		return (lle);
1700 
1701 	if (flags & LLE_EXCLUSIVE)
1702 		LLE_WLOCK(lle);
1703 	else
1704 		LLE_RLOCK(lle);
1705 
1706 	/*
1707 	 * If the afdata lock is not held, the LLE may have been unlinked while
1708 	 * we were blocked on the LLE lock.  Check for this case.
1709 	 */
1710 	if (__predict_false((lle->la_flags & LLE_LINKED) == 0)) {
1711 		if (flags & LLE_EXCLUSIVE)
1712 			LLE_WUNLOCK(lle);
1713 		else
1714 			LLE_RUNLOCK(lle);
1715 		return (NULL);
1716 	}
1717 	return (lle);
1718 }
1719 
1720 static int
1721 in_lltable_dump_entry(struct lltable *llt, struct llentry *lle,
1722     struct sysctl_req *wr)
1723 {
1724 	struct ifnet *ifp = llt->llt_ifp;
1725 	/* XXX stack use */
1726 	struct {
1727 		struct rt_msghdr	rtm;
1728 		struct sockaddr_in	sin;
1729 		struct sockaddr_dl	sdl;
1730 	} arpc;
1731 	struct sockaddr_dl *sdl;
1732 	int error;
1733 
1734 	bzero(&arpc, sizeof(arpc));
1735 	/* skip deleted entries */
1736 	if ((lle->la_flags & LLE_DELETED) == LLE_DELETED)
1737 		return (0);
1738 	/* Skip if jailed and not a valid IP of the prison. */
1739 	lltable_fill_sa_entry(lle,(struct sockaddr *)&arpc.sin);
1740 	if (prison_if(wr->td->td_ucred, (struct sockaddr *)&arpc.sin) != 0)
1741 		return (0);
1742 	/*
1743 	 * produce a msg made of:
1744 	 *  struct rt_msghdr;
1745 	 *  struct sockaddr_in; (IPv4)
1746 	 *  struct sockaddr_dl;
1747 	 */
1748 	arpc.rtm.rtm_msglen = sizeof(arpc);
1749 	arpc.rtm.rtm_version = RTM_VERSION;
1750 	arpc.rtm.rtm_type = RTM_GET;
1751 	arpc.rtm.rtm_flags = RTF_UP;
1752 	arpc.rtm.rtm_addrs = RTA_DST | RTA_GATEWAY;
1753 
1754 	/* publish */
1755 	if (lle->la_flags & LLE_PUB)
1756 		arpc.rtm.rtm_flags |= RTF_ANNOUNCE;
1757 
1758 	sdl = &arpc.sdl;
1759 	sdl->sdl_family = AF_LINK;
1760 	sdl->sdl_len = sizeof(*sdl);
1761 	sdl->sdl_index = ifp->if_index;
1762 	sdl->sdl_type = ifp->if_type;
1763 	if ((lle->la_flags & LLE_VALID) == LLE_VALID) {
1764 		sdl->sdl_alen = ifp->if_addrlen;
1765 		bcopy(lle->ll_addr, LLADDR(sdl), ifp->if_addrlen);
1766 	} else {
1767 		sdl->sdl_alen = 0;
1768 		bzero(LLADDR(sdl), ifp->if_addrlen);
1769 	}
1770 
1771 	arpc.rtm.rtm_rmx.rmx_expire =
1772 	    lle->la_flags & LLE_STATIC ? 0 : lle->la_expire;
1773 	arpc.rtm.rtm_flags |= (RTF_HOST | RTF_LLDATA);
1774 	if (lle->la_flags & LLE_STATIC)
1775 		arpc.rtm.rtm_flags |= RTF_STATIC;
1776 	if (lle->la_flags & LLE_IFADDR)
1777 		arpc.rtm.rtm_flags |= RTF_PINNED;
1778 	arpc.rtm.rtm_index = ifp->if_index;
1779 	error = SYSCTL_OUT(wr, &arpc, sizeof(arpc));
1780 
1781 	return (error);
1782 }
1783 
1784 static void
1785 in_lltable_post_resolved(struct lltable *llt, struct llentry *lle)
1786 {
1787 	struct ifnet *ifp = llt->llt_ifp;
1788 
1789 	/* gratuitous ARP */
1790 	if ((lle->la_flags & LLE_PUB) != 0)
1791 		arprequest(ifp, &lle->r_l3addr.addr4, &lle->r_l3addr.addr4,
1792 		    lle->ll_addr);
1793 }
1794 
1795 static struct lltable *
1796 in_lltattach(struct ifnet *ifp)
1797 {
1798 	struct lltable *llt;
1799 
1800 	llt = lltable_allocate_htbl(IN_LLTBL_DEFAULT_HSIZE);
1801  	llt->llt_af = AF_INET;
1802  	llt->llt_ifp = ifp;
1803 
1804 	llt->llt_lookup = in_lltable_lookup;
1805 	llt->llt_alloc_entry = in_lltable_alloc;
1806 	llt->llt_delete_entry = in_lltable_delete_entry;
1807 	llt->llt_dump_entry = in_lltable_dump_entry;
1808 	llt->llt_hash = in_lltable_hash;
1809 	llt->llt_fill_sa_entry = in_lltable_fill_sa_entry;
1810 	llt->llt_free_entry = in_lltable_free_entry;
1811 	llt->llt_match_prefix = in_lltable_match_prefix;
1812 	llt->llt_mark_used = llentry_mark_used;
1813 	llt->llt_post_resolved = in_lltable_post_resolved;
1814  	lltable_link(llt);
1815 
1816 	return (llt);
1817 }
1818 
1819 struct lltable *
1820 in_lltable_get(struct ifnet *ifp)
1821 {
1822 	struct lltable *llt = NULL;
1823 
1824 	void *afdata_ptr = ifp->if_afdata[AF_INET];
1825 	if (afdata_ptr != NULL)
1826 		llt = ((struct in_ifinfo *)afdata_ptr)->ii_llt;
1827 	return (llt);
1828 }
1829 
1830 void *
1831 in_domifattach(struct ifnet *ifp)
1832 {
1833 	struct in_ifinfo *ii;
1834 
1835 	ii = malloc(sizeof(struct in_ifinfo), M_IFADDR, M_WAITOK|M_ZERO);
1836 
1837 	ii->ii_llt = in_lltattach(ifp);
1838 	ii->ii_igmp = igmp_domifattach(ifp);
1839 
1840 	return (ii);
1841 }
1842 
1843 void
1844 in_domifdetach(struct ifnet *ifp, void *aux)
1845 {
1846 	struct in_ifinfo *ii = (struct in_ifinfo *)aux;
1847 
1848 	igmp_domifdetach(ifp);
1849 	lltable_free(ii->ii_llt);
1850 	free(ii, M_IFADDR);
1851 }
1852