xref: /freebsd/sys/netinet/in.c (revision c66ec88fed842fbaad62c30d510644ceb7bd2d71)
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 <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/lock.h>
48 #include <sys/proc.h>
49 #include <sys/rmlock.h>
50 #include <sys/sysctl.h>
51 #include <sys/syslog.h>
52 #include <sys/sx.h>
53 
54 #include <net/if.h>
55 #include <net/if_var.h>
56 #include <net/if_arp.h>
57 #include <net/if_dl.h>
58 #include <net/if_llatbl.h>
59 #include <net/if_types.h>
60 #include <net/route.h>
61 #include <net/vnet.h>
62 
63 #include <netinet/if_ether.h>
64 #include <netinet/in.h>
65 #include <netinet/in_var.h>
66 #include <netinet/in_pcb.h>
67 #include <netinet/ip_var.h>
68 #include <netinet/ip_carp.h>
69 #include <netinet/igmp_var.h>
70 #include <netinet/udp.h>
71 #include <netinet/udp_var.h>
72 
73 static int in_aifaddr_ioctl(u_long, caddr_t, struct ifnet *, struct thread *);
74 static int in_difaddr_ioctl(u_long, caddr_t, struct ifnet *, struct thread *);
75 static int in_gifaddr_ioctl(u_long, caddr_t, struct ifnet *, struct thread *);
76 
77 static void	in_socktrim(struct sockaddr_in *);
78 static void	in_purgemaddrs(struct ifnet *);
79 
80 VNET_DEFINE_STATIC(int, nosameprefix);
81 #define	V_nosameprefix			VNET(nosameprefix)
82 SYSCTL_INT(_net_inet_ip, OID_AUTO, no_same_prefix, CTLFLAG_VNET | CTLFLAG_RW,
83 	&VNET_NAME(nosameprefix), 0,
84 	"Refuse to create same prefixes on different interfaces");
85 
86 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
87 #define	V_ripcbinfo			VNET(ripcbinfo)
88 
89 static struct sx in_control_sx;
90 SX_SYSINIT(in_control_sx, &in_control_sx, "in_control");
91 
92 /*
93  * Return 1 if an internet address is for a ``local'' host
94  * (one to which we have a connection).
95  */
96 int
97 in_localaddr(struct in_addr in)
98 {
99 	struct rm_priotracker in_ifa_tracker;
100 	u_long i = ntohl(in.s_addr);
101 	struct in_ifaddr *ia;
102 
103 	IN_IFADDR_RLOCK(&in_ifa_tracker);
104 	CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
105 		if ((i & ia->ia_subnetmask) == ia->ia_subnet) {
106 			IN_IFADDR_RUNLOCK(&in_ifa_tracker);
107 			return (1);
108 		}
109 	}
110 	IN_IFADDR_RUNLOCK(&in_ifa_tracker);
111 	return (0);
112 }
113 
114 /*
115  * Return 1 if an internet address is for the local host and configured
116  * on one of its interfaces.
117  */
118 int
119 in_localip(struct in_addr in)
120 {
121 	struct rm_priotracker in_ifa_tracker;
122 	struct in_ifaddr *ia;
123 
124 	IN_IFADDR_RLOCK(&in_ifa_tracker);
125 	LIST_FOREACH(ia, INADDR_HASH(in.s_addr), ia_hash) {
126 		if (IA_SIN(ia)->sin_addr.s_addr == in.s_addr) {
127 			IN_IFADDR_RUNLOCK(&in_ifa_tracker);
128 			return (1);
129 		}
130 	}
131 	IN_IFADDR_RUNLOCK(&in_ifa_tracker);
132 	return (0);
133 }
134 
135 /*
136  * Return 1 if an internet address is configured on an interface.
137  */
138 int
139 in_ifhasaddr(struct ifnet *ifp, struct in_addr in)
140 {
141 	struct ifaddr *ifa;
142 	struct in_ifaddr *ia;
143 
144 	NET_EPOCH_ASSERT();
145 
146 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
147 		if (ifa->ifa_addr->sa_family != AF_INET)
148 			continue;
149 		ia = (struct in_ifaddr *)ifa;
150 		if (ia->ia_addr.sin_addr.s_addr == in.s_addr)
151 			return (1);
152 	}
153 
154 	return (0);
155 }
156 
157 /*
158  * Return a reference to the interface address which is different to
159  * the supplied one but with same IP address value.
160  */
161 static struct in_ifaddr *
162 in_localip_more(struct in_ifaddr *ia)
163 {
164 	struct rm_priotracker in_ifa_tracker;
165 	in_addr_t in = IA_SIN(ia)->sin_addr.s_addr;
166 	struct in_ifaddr *it;
167 
168 	IN_IFADDR_RLOCK(&in_ifa_tracker);
169 	LIST_FOREACH(it, INADDR_HASH(in), ia_hash) {
170 		if (it != ia && IA_SIN(it)->sin_addr.s_addr == in) {
171 			ifa_ref(&it->ia_ifa);
172 			IN_IFADDR_RUNLOCK(&in_ifa_tracker);
173 			return (it);
174 		}
175 	}
176 	IN_IFADDR_RUNLOCK(&in_ifa_tracker);
177 
178 	return (NULL);
179 }
180 
181 /*
182  * Determine whether an IP address is in a reserved set of addresses
183  * that may not be forwarded, or whether datagrams to that destination
184  * may be forwarded.
185  */
186 int
187 in_canforward(struct in_addr in)
188 {
189 	u_long i = ntohl(in.s_addr);
190 
191 	if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i) || IN_LINKLOCAL(i) ||
192 	    IN_ZERONET(i) || IN_LOOPBACK(i))
193 		return (0);
194 	return (1);
195 }
196 
197 /*
198  * Trim a mask in a sockaddr
199  */
200 static void
201 in_socktrim(struct sockaddr_in *ap)
202 {
203     char *cplim = (char *) &ap->sin_addr;
204     char *cp = (char *) (&ap->sin_addr + 1);
205 
206     ap->sin_len = 0;
207     while (--cp >= cplim)
208 	if (*cp) {
209 	    (ap)->sin_len = cp - (char *) (ap) + 1;
210 	    break;
211 	}
212 }
213 
214 /*
215  * Generic internet control operations (ioctl's).
216  */
217 int
218 in_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
219     struct thread *td)
220 {
221 	struct ifreq *ifr = (struct ifreq *)data;
222 	struct sockaddr_in *addr = (struct sockaddr_in *)&ifr->ifr_addr;
223 	struct epoch_tracker et;
224 	struct ifaddr *ifa;
225 	struct in_ifaddr *ia;
226 	int error;
227 
228 	if (ifp == NULL)
229 		return (EADDRNOTAVAIL);
230 
231 	/*
232 	 * Filter out 4 ioctls we implement directly.  Forward the rest
233 	 * to specific functions and ifp->if_ioctl().
234 	 */
235 	switch (cmd) {
236 	case SIOCGIFADDR:
237 	case SIOCGIFBRDADDR:
238 	case SIOCGIFDSTADDR:
239 	case SIOCGIFNETMASK:
240 		break;
241 	case SIOCGIFALIAS:
242 		sx_xlock(&in_control_sx);
243 		error = in_gifaddr_ioctl(cmd, data, ifp, td);
244 		sx_xunlock(&in_control_sx);
245 		return (error);
246 	case SIOCDIFADDR:
247 		sx_xlock(&in_control_sx);
248 		error = in_difaddr_ioctl(cmd, data, ifp, td);
249 		sx_xunlock(&in_control_sx);
250 		return (error);
251 	case OSIOCAIFADDR:	/* 9.x compat */
252 	case SIOCAIFADDR:
253 		sx_xlock(&in_control_sx);
254 		error = in_aifaddr_ioctl(cmd, data, ifp, td);
255 		sx_xunlock(&in_control_sx);
256 		return (error);
257 	case SIOCSIFADDR:
258 	case SIOCSIFBRDADDR:
259 	case SIOCSIFDSTADDR:
260 	case SIOCSIFNETMASK:
261 		/* We no longer support that old commands. */
262 		return (EINVAL);
263 	default:
264 		if (ifp->if_ioctl == NULL)
265 			return (EOPNOTSUPP);
266 		return ((*ifp->if_ioctl)(ifp, cmd, data));
267 	}
268 
269 	if (addr->sin_addr.s_addr != INADDR_ANY &&
270 	    prison_check_ip4(td->td_ucred, &addr->sin_addr) != 0)
271 		return (EADDRNOTAVAIL);
272 
273 	/*
274 	 * Find address for this interface, if it exists.  If an
275 	 * address was specified, find that one instead of the
276 	 * first one on the interface, if possible.
277 	 */
278 	NET_EPOCH_ENTER(et);
279 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
280 		if (ifa->ifa_addr->sa_family != AF_INET)
281 			continue;
282 		ia = (struct in_ifaddr *)ifa;
283 		if (ia->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr)
284 			break;
285 	}
286 	if (ifa == NULL)
287 		CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
288 			if (ifa->ifa_addr->sa_family == AF_INET) {
289 				ia = (struct in_ifaddr *)ifa;
290 				if (prison_check_ip4(td->td_ucred,
291 				    &ia->ia_addr.sin_addr) == 0)
292 					break;
293 			}
294 
295 	if (ifa == NULL) {
296 		NET_EPOCH_EXIT(et);
297 		return (EADDRNOTAVAIL);
298 	}
299 
300 	error = 0;
301 	switch (cmd) {
302 	case SIOCGIFADDR:
303 		*addr = ia->ia_addr;
304 		break;
305 
306 	case SIOCGIFBRDADDR:
307 		if ((ifp->if_flags & IFF_BROADCAST) == 0) {
308 			error = EINVAL;
309 			break;
310 		}
311 		*addr = ia->ia_broadaddr;
312 		break;
313 
314 	case SIOCGIFDSTADDR:
315 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0) {
316 			error = EINVAL;
317 			break;
318 		}
319 		*addr = ia->ia_dstaddr;
320 		break;
321 
322 	case SIOCGIFNETMASK:
323 		*addr = ia->ia_sockmask;
324 		break;
325 	}
326 
327 	NET_EPOCH_EXIT(et);
328 
329 	return (error);
330 }
331 
332 static int
333 in_aifaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct thread *td)
334 {
335 	const struct in_aliasreq *ifra = (struct in_aliasreq *)data;
336 	const struct sockaddr_in *addr = &ifra->ifra_addr;
337 	const struct sockaddr_in *broadaddr = &ifra->ifra_broadaddr;
338 	const struct sockaddr_in *mask = &ifra->ifra_mask;
339 	const struct sockaddr_in *dstaddr = &ifra->ifra_dstaddr;
340 	const int vhid = (cmd == SIOCAIFADDR) ? ifra->ifra_vhid : 0;
341 	struct epoch_tracker et;
342 	struct ifaddr *ifa;
343 	struct in_ifaddr *ia;
344 	bool iaIsFirst;
345 	int error = 0;
346 
347 	error = priv_check(td, PRIV_NET_ADDIFADDR);
348 	if (error)
349 		return (error);
350 
351 	/*
352 	 * ifra_addr must be present and be of INET family.
353 	 * ifra_broadaddr/ifra_dstaddr and ifra_mask are optional.
354 	 */
355 	if (addr->sin_len != sizeof(struct sockaddr_in) ||
356 	    addr->sin_family != AF_INET)
357 		return (EINVAL);
358 	if (broadaddr->sin_len != 0 &&
359 	    (broadaddr->sin_len != sizeof(struct sockaddr_in) ||
360 	    broadaddr->sin_family != AF_INET))
361 		return (EINVAL);
362 	if (mask->sin_len != 0 &&
363 	    (mask->sin_len != sizeof(struct sockaddr_in) ||
364 	    mask->sin_family != AF_INET))
365 		return (EINVAL);
366 	if ((ifp->if_flags & IFF_POINTOPOINT) &&
367 	    (dstaddr->sin_len != sizeof(struct sockaddr_in) ||
368 	     dstaddr->sin_addr.s_addr == INADDR_ANY))
369 		return (EDESTADDRREQ);
370 	if (vhid > 0 && carp_attach_p == NULL)
371 		return (EPROTONOSUPPORT);
372 
373 	/*
374 	 * See whether address already exist.
375 	 */
376 	iaIsFirst = true;
377 	ia = NULL;
378 	NET_EPOCH_ENTER(et);
379 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
380 		struct in_ifaddr *it;
381 
382 		if (ifa->ifa_addr->sa_family != AF_INET)
383 			continue;
384 
385 		it = (struct in_ifaddr *)ifa;
386 		if (it->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr &&
387 		    prison_check_ip4(td->td_ucred, &addr->sin_addr) == 0)
388 			ia = it;
389 		else
390 			iaIsFirst = false;
391 	}
392 	NET_EPOCH_EXIT(et);
393 
394 	if (ia != NULL)
395 		(void )in_difaddr_ioctl(cmd, data, ifp, td);
396 
397 	ifa = ifa_alloc(sizeof(struct in_ifaddr), M_WAITOK);
398 	ia = (struct in_ifaddr *)ifa;
399 	ifa->ifa_addr = (struct sockaddr *)&ia->ia_addr;
400 	ifa->ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr;
401 	ifa->ifa_netmask = (struct sockaddr *)&ia->ia_sockmask;
402 	callout_init_rw(&ia->ia_garp_timer, &ifp->if_addr_lock,
403 	    CALLOUT_RETURNUNLOCKED);
404 
405 	ia->ia_ifp = ifp;
406 	ia->ia_addr = *addr;
407 	if (mask->sin_len != 0) {
408 		ia->ia_sockmask = *mask;
409 		ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr);
410 	} else {
411 		in_addr_t i = ntohl(addr->sin_addr.s_addr);
412 
413 		/*
414 	 	 * Be compatible with network classes, if netmask isn't
415 		 * supplied, guess it based on classes.
416 	 	 */
417 		if (IN_CLASSA(i))
418 			ia->ia_subnetmask = IN_CLASSA_NET;
419 		else if (IN_CLASSB(i))
420 			ia->ia_subnetmask = IN_CLASSB_NET;
421 		else
422 			ia->ia_subnetmask = IN_CLASSC_NET;
423 		ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
424 	}
425 	ia->ia_subnet = ntohl(addr->sin_addr.s_addr) & ia->ia_subnetmask;
426 	in_socktrim(&ia->ia_sockmask);
427 
428 	if (ifp->if_flags & IFF_BROADCAST) {
429 		if (broadaddr->sin_len != 0) {
430 			ia->ia_broadaddr = *broadaddr;
431 		} else if (ia->ia_subnetmask == IN_RFC3021_MASK) {
432 			ia->ia_broadaddr.sin_addr.s_addr = INADDR_BROADCAST;
433 			ia->ia_broadaddr.sin_len = sizeof(struct sockaddr_in);
434 			ia->ia_broadaddr.sin_family = AF_INET;
435 		} else {
436 			ia->ia_broadaddr.sin_addr.s_addr =
437 			    htonl(ia->ia_subnet | ~ia->ia_subnetmask);
438 			ia->ia_broadaddr.sin_len = sizeof(struct sockaddr_in);
439 			ia->ia_broadaddr.sin_family = AF_INET;
440 		}
441 	}
442 
443 	if (ifp->if_flags & IFF_POINTOPOINT)
444 		ia->ia_dstaddr = *dstaddr;
445 
446 	/* XXXGL: rtinit() needs this strange assignment. */
447 	if (ifp->if_flags & IFF_LOOPBACK)
448                 ia->ia_dstaddr = ia->ia_addr;
449 
450 	if (vhid != 0) {
451 		error = (*carp_attach_p)(&ia->ia_ifa, vhid);
452 		if (error)
453 			return (error);
454 	}
455 
456 	/* if_addrhead is already referenced by ifa_alloc() */
457 	IF_ADDR_WLOCK(ifp);
458 	CK_STAILQ_INSERT_TAIL(&ifp->if_addrhead, ifa, ifa_link);
459 	IF_ADDR_WUNLOCK(ifp);
460 
461 	ifa_ref(ifa);			/* in_ifaddrhead */
462 	IN_IFADDR_WLOCK();
463 	CK_STAILQ_INSERT_TAIL(&V_in_ifaddrhead, ia, ia_link);
464 	LIST_INSERT_HEAD(INADDR_HASH(ia->ia_addr.sin_addr.s_addr), ia, ia_hash);
465 	IN_IFADDR_WUNLOCK();
466 
467 	/*
468 	 * Give the interface a chance to initialize
469 	 * if this is its first address,
470 	 * and to validate the address if necessary.
471 	 */
472 	if (ifp->if_ioctl != NULL) {
473 		error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia);
474 		if (error)
475 			goto fail1;
476 	}
477 
478 	/*
479 	 * Add route for the network.
480 	 */
481 	if (vhid == 0) {
482 		int flags = RTF_UP;
483 
484 		if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT))
485 			flags |= RTF_HOST;
486 
487 		error = in_addprefix(ia, flags);
488 		if (error)
489 			goto fail1;
490 	}
491 
492 	/*
493 	 * Add a loopback route to self.
494 	 */
495 	if (vhid == 0 && (ifp->if_flags & IFF_LOOPBACK) == 0 &&
496 	    ia->ia_addr.sin_addr.s_addr != INADDR_ANY &&
497 	    !((ifp->if_flags & IFF_POINTOPOINT) &&
498 	     ia->ia_dstaddr.sin_addr.s_addr == ia->ia_addr.sin_addr.s_addr)) {
499 		struct in_ifaddr *eia;
500 
501 		eia = in_localip_more(ia);
502 
503 		if (eia == NULL) {
504 			error = ifa_add_loopback_route((struct ifaddr *)ia,
505 			    (struct sockaddr *)&ia->ia_addr);
506 			if (error)
507 				goto fail2;
508 		} else
509 			ifa_free(&eia->ia_ifa);
510 	}
511 
512 	if (iaIsFirst && (ifp->if_flags & IFF_MULTICAST)) {
513 		struct in_addr allhosts_addr;
514 		struct in_ifinfo *ii;
515 
516 		ii = ((struct in_ifinfo *)ifp->if_afdata[AF_INET]);
517 		allhosts_addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
518 
519 		error = in_joingroup(ifp, &allhosts_addr, NULL,
520 			&ii->ii_allhosts);
521 	}
522 
523 	/*
524 	 * Note: we don't need extra reference for ifa, since we called
525 	 * with sx lock held, and ifaddr can not be deleted in concurrent
526 	 * thread.
527 	 */
528 	EVENTHANDLER_INVOKE(ifaddr_event_ext, ifp, ifa, IFADDR_EVENT_ADD);
529 
530 	return (error);
531 
532 fail2:
533 	if (vhid == 0)
534 		(void )in_scrubprefix(ia, LLE_STATIC);
535 
536 fail1:
537 	if (ia->ia_ifa.ifa_carp)
538 		(*carp_detach_p)(&ia->ia_ifa, false);
539 
540 	IF_ADDR_WLOCK(ifp);
541 	CK_STAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifaddr, ifa_link);
542 	IF_ADDR_WUNLOCK(ifp);
543 	ifa_free(&ia->ia_ifa);		/* if_addrhead */
544 
545 	IN_IFADDR_WLOCK();
546 	CK_STAILQ_REMOVE(&V_in_ifaddrhead, ia, in_ifaddr, ia_link);
547 	LIST_REMOVE(ia, ia_hash);
548 	IN_IFADDR_WUNLOCK();
549 	ifa_free(&ia->ia_ifa);		/* in_ifaddrhead */
550 
551 	return (error);
552 }
553 
554 static int
555 in_difaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct thread *td)
556 {
557 	const struct ifreq *ifr = (struct ifreq *)data;
558 	const struct sockaddr_in *addr = (const struct sockaddr_in *)
559 	    &ifr->ifr_addr;
560 	struct ifaddr *ifa;
561 	struct in_ifaddr *ia;
562 	bool deleteAny, iaIsLast;
563 	int error;
564 
565 	if (td != NULL) {
566 		error = priv_check(td, PRIV_NET_DELIFADDR);
567 		if (error)
568 			return (error);
569 	}
570 
571 	if (addr->sin_len != sizeof(struct sockaddr_in) ||
572 	    addr->sin_family != AF_INET)
573 		deleteAny = true;
574 	else
575 		deleteAny = false;
576 
577 	iaIsLast = true;
578 	ia = NULL;
579 	IF_ADDR_WLOCK(ifp);
580 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
581 		struct in_ifaddr *it;
582 
583 		if (ifa->ifa_addr->sa_family != AF_INET)
584 			continue;
585 
586 		it = (struct in_ifaddr *)ifa;
587 		if (deleteAny && ia == NULL && (td == NULL ||
588 		    prison_check_ip4(td->td_ucred, &it->ia_addr.sin_addr) == 0))
589 			ia = it;
590 
591 		if (it->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr &&
592 		    (td == NULL || prison_check_ip4(td->td_ucred,
593 		    &addr->sin_addr) == 0))
594 			ia = it;
595 
596 		if (it != ia)
597 			iaIsLast = false;
598 	}
599 
600 	if (ia == NULL) {
601 		IF_ADDR_WUNLOCK(ifp);
602 		return (EADDRNOTAVAIL);
603 	}
604 
605 	CK_STAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifaddr, ifa_link);
606 	IF_ADDR_WUNLOCK(ifp);
607 	ifa_free(&ia->ia_ifa);		/* if_addrhead */
608 
609 	IN_IFADDR_WLOCK();
610 	CK_STAILQ_REMOVE(&V_in_ifaddrhead, ia, in_ifaddr, ia_link);
611 	LIST_REMOVE(ia, ia_hash);
612 	IN_IFADDR_WUNLOCK();
613 
614 	/*
615 	 * in_scrubprefix() kills the interface route.
616 	 */
617 	in_scrubprefix(ia, LLE_STATIC);
618 
619 	/*
620 	 * in_ifadown gets rid of all the rest of
621 	 * the routes.  This is not quite the right
622 	 * thing to do, but at least if we are running
623 	 * a routing process they will come back.
624 	 */
625 	in_ifadown(&ia->ia_ifa, 1);
626 
627 	if (ia->ia_ifa.ifa_carp)
628 		(*carp_detach_p)(&ia->ia_ifa, cmd == SIOCAIFADDR);
629 
630 	/*
631 	 * If this is the last IPv4 address configured on this
632 	 * interface, leave the all-hosts group.
633 	 * No state-change report need be transmitted.
634 	 */
635 	if (iaIsLast && (ifp->if_flags & IFF_MULTICAST)) {
636 		struct in_ifinfo *ii;
637 
638 		ii = ((struct in_ifinfo *)ifp->if_afdata[AF_INET]);
639 		if (ii->ii_allhosts) {
640 			(void)in_leavegroup(ii->ii_allhosts, NULL);
641 			ii->ii_allhosts = NULL;
642 		}
643 	}
644 
645 	IF_ADDR_WLOCK(ifp);
646 	if (callout_stop(&ia->ia_garp_timer) == 1) {
647 		ifa_free(&ia->ia_ifa);
648 	}
649 	IF_ADDR_WUNLOCK(ifp);
650 
651 	EVENTHANDLER_INVOKE(ifaddr_event_ext, ifp, &ia->ia_ifa,
652 	    IFADDR_EVENT_DEL);
653 	ifa_free(&ia->ia_ifa);		/* in_ifaddrhead */
654 
655 	return (0);
656 }
657 
658 static int
659 in_gifaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct thread *td)
660 {
661 	struct in_aliasreq *ifra = (struct in_aliasreq *)data;
662 	const struct sockaddr_in *addr = &ifra->ifra_addr;
663 	struct epoch_tracker et;
664 	struct ifaddr *ifa;
665 	struct in_ifaddr *ia;
666 
667 	/*
668 	 * ifra_addr must be present and be of INET family.
669 	 */
670 	if (addr->sin_len != sizeof(struct sockaddr_in) ||
671 	    addr->sin_family != AF_INET)
672 		return (EINVAL);
673 
674 	/*
675 	 * See whether address exist.
676 	 */
677 	ia = NULL;
678 	NET_EPOCH_ENTER(et);
679 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
680 		struct in_ifaddr *it;
681 
682 		if (ifa->ifa_addr->sa_family != AF_INET)
683 			continue;
684 
685 		it = (struct in_ifaddr *)ifa;
686 		if (it->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr &&
687 		    prison_check_ip4(td->td_ucred, &addr->sin_addr) == 0) {
688 			ia = it;
689 			break;
690 		}
691 	}
692 	if (ia == NULL) {
693 		NET_EPOCH_EXIT(et);
694 		return (EADDRNOTAVAIL);
695 	}
696 
697 	ifra->ifra_mask = ia->ia_sockmask;
698 	if ((ifp->if_flags & IFF_POINTOPOINT) &&
699 	    ia->ia_dstaddr.sin_family == AF_INET)
700 		ifra->ifra_dstaddr = ia->ia_dstaddr;
701 	else if ((ifp->if_flags & IFF_BROADCAST) &&
702 	    ia->ia_broadaddr.sin_family == AF_INET)
703 		ifra->ifra_broadaddr = ia->ia_broadaddr;
704 	else
705 		memset(&ifra->ifra_broadaddr, 0,
706 		    sizeof(ifra->ifra_broadaddr));
707 
708 	NET_EPOCH_EXIT(et);
709 	return (0);
710 }
711 
712 #define rtinitflags(x) \
713 	((((x)->ia_ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) != 0) \
714 	    ? RTF_HOST : 0)
715 
716 /*
717  * Check if we have a route for the given prefix already.
718  */
719 static bool
720 in_hasrtprefix(struct in_ifaddr *target, int flags)
721 {
722 	struct rm_priotracker in_ifa_tracker;
723 	struct in_ifaddr *ia;
724 	struct in_addr prefix, mask, p, m;
725 	bool result = false;
726 
727 	if ((flags & RTF_HOST) != 0) {
728 		prefix = target->ia_dstaddr.sin_addr;
729 		mask.s_addr = 0;
730 	} else {
731 		prefix = target->ia_addr.sin_addr;
732 		mask = target->ia_sockmask.sin_addr;
733 		prefix.s_addr &= mask.s_addr;
734 	}
735 
736 	IN_IFADDR_RLOCK(&in_ifa_tracker);
737 	/* Look for an existing address with the same prefix, mask, and fib */
738 	CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
739 		if (rtinitflags(ia)) {
740 			p = ia->ia_dstaddr.sin_addr;
741 
742 			if (prefix.s_addr != p.s_addr)
743 				continue;
744 		} else {
745 			p = ia->ia_addr.sin_addr;
746 			m = ia->ia_sockmask.sin_addr;
747 			p.s_addr &= m.s_addr;
748 
749 			if (prefix.s_addr != p.s_addr ||
750 			    mask.s_addr != m.s_addr)
751 				continue;
752 		}
753 		if (target->ia_ifp->if_fib != ia->ia_ifp->if_fib)
754 			continue;
755 
756 		/*
757 		 * If we got a matching prefix route inserted by other
758 		 * interface address, we are done here.
759 		 */
760 		if (ia->ia_flags & IFA_ROUTE) {
761 			result = true;
762 			break;
763 		}
764 	}
765 	IN_IFADDR_RUNLOCK(&in_ifa_tracker);
766 
767 	return (result);
768 }
769 
770 int
771 in_addprefix(struct in_ifaddr *target, int flags)
772 {
773 	int error;
774 
775 	if (in_hasrtprefix(target, flags)) {
776 		if (V_nosameprefix)
777 			return (EEXIST);
778 		else {
779 			rt_addrmsg(RTM_ADD, &target->ia_ifa,
780 			    target->ia_ifp->if_fib);
781 			return (0);
782 		}
783 	}
784 
785 	/*
786 	 * No-one seem to have this prefix route, so we try to insert it.
787 	 */
788 	error = rtinit(&target->ia_ifa, (int)RTM_ADD, flags);
789 	if (!error)
790 		target->ia_flags |= IFA_ROUTE;
791 	return (error);
792 }
793 
794 /*
795  * Removes either all lle entries for given @ia, or lle
796  * corresponding to @ia address.
797  */
798 static void
799 in_scrubprefixlle(struct in_ifaddr *ia, int all, u_int flags)
800 {
801 	struct sockaddr_in addr, mask;
802 	struct sockaddr *saddr, *smask;
803 	struct ifnet *ifp;
804 
805 	saddr = (struct sockaddr *)&addr;
806 	bzero(&addr, sizeof(addr));
807 	addr.sin_len = sizeof(addr);
808 	addr.sin_family = AF_INET;
809 	smask = (struct sockaddr *)&mask;
810 	bzero(&mask, sizeof(mask));
811 	mask.sin_len = sizeof(mask);
812 	mask.sin_family = AF_INET;
813 	mask.sin_addr.s_addr = ia->ia_subnetmask;
814 	ifp = ia->ia_ifp;
815 
816 	if (all) {
817 		/*
818 		 * Remove all L2 entries matching given prefix.
819 		 * Convert address to host representation to avoid
820 		 * doing this on every callback. ia_subnetmask is already
821 		 * stored in host representation.
822 		 */
823 		addr.sin_addr.s_addr = ntohl(ia->ia_addr.sin_addr.s_addr);
824 		lltable_prefix_free(AF_INET, saddr, smask, flags);
825 	} else {
826 		/* Remove interface address only */
827 		addr.sin_addr.s_addr = ia->ia_addr.sin_addr.s_addr;
828 		lltable_delete_addr(LLTABLE(ifp), LLE_IFADDR, saddr);
829 	}
830 }
831 
832 /*
833  * If there is no other address in the system that can serve a route to the
834  * same prefix, remove the route.  Hand over the route to the new address
835  * otherwise.
836  */
837 int
838 in_scrubprefix(struct in_ifaddr *target, u_int flags)
839 {
840 	struct rm_priotracker in_ifa_tracker;
841 	struct in_ifaddr *ia;
842 	struct in_addr prefix, mask, p, m;
843 	int error = 0;
844 
845 	/*
846 	 * Remove the loopback route to the interface address.
847 	 */
848 	if ((target->ia_addr.sin_addr.s_addr != INADDR_ANY) &&
849 	    !(target->ia_ifp->if_flags & IFF_LOOPBACK) &&
850 	    (flags & LLE_STATIC)) {
851 		struct in_ifaddr *eia;
852 
853 		/*
854 		 * XXXME: add fib-aware in_localip.
855 		 * We definitely don't want to switch between
856 		 * prefixes in different fibs.
857 		 */
858 		eia = in_localip_more(target);
859 
860 		if (eia != NULL) {
861 			error = ifa_switch_loopback_route((struct ifaddr *)eia,
862 			    (struct sockaddr *)&target->ia_addr);
863 			ifa_free(&eia->ia_ifa);
864 		} else {
865 			error = ifa_del_loopback_route((struct ifaddr *)target,
866 			    (struct sockaddr *)&target->ia_addr);
867 		}
868 	}
869 
870 	if (rtinitflags(target)) {
871 		prefix = target->ia_dstaddr.sin_addr;
872 		mask.s_addr = 0;
873 	} else {
874 		prefix = target->ia_addr.sin_addr;
875 		mask = target->ia_sockmask.sin_addr;
876 		prefix.s_addr &= mask.s_addr;
877 	}
878 
879 	if ((target->ia_flags & IFA_ROUTE) == 0) {
880 		rt_addrmsg(RTM_DELETE, &target->ia_ifa, target->ia_ifp->if_fib);
881 
882 		/*
883 		 * Removing address from !IFF_UP interface or
884 		 * prefix which exists on other interface (along with route).
885 		 * No entries should exist here except target addr.
886 		 * Given that, delete this entry only.
887 		 */
888 		in_scrubprefixlle(target, 0, flags);
889 		return (0);
890 	}
891 
892 	IN_IFADDR_RLOCK(&in_ifa_tracker);
893 	CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
894 		if (rtinitflags(ia)) {
895 			p = ia->ia_dstaddr.sin_addr;
896 
897 			if (prefix.s_addr != p.s_addr)
898 				continue;
899 		} else {
900 			p = ia->ia_addr.sin_addr;
901 			m = ia->ia_sockmask.sin_addr;
902 			p.s_addr &= m.s_addr;
903 
904 			if (prefix.s_addr != p.s_addr ||
905 			    mask.s_addr != m.s_addr)
906 				continue;
907 		}
908 
909 		if ((ia->ia_ifp->if_flags & IFF_UP) == 0)
910 			continue;
911 
912 		/*
913 		 * If we got a matching prefix address, move IFA_ROUTE and
914 		 * the route itself to it.  Make sure that routing daemons
915 		 * get a heads-up.
916 		 */
917 		if ((ia->ia_flags & IFA_ROUTE) == 0) {
918 			ifa_ref(&ia->ia_ifa);
919 			IN_IFADDR_RUNLOCK(&in_ifa_tracker);
920 			error = rtinit(&(target->ia_ifa), (int)RTM_DELETE,
921 			    rtinitflags(target));
922 			if (error == 0)
923 				target->ia_flags &= ~IFA_ROUTE;
924 			else
925 				log(LOG_INFO, "in_scrubprefix: err=%d, old prefix delete failed\n",
926 					error);
927 			/* Scrub all entries IFF interface is different */
928 			in_scrubprefixlle(target, target->ia_ifp != ia->ia_ifp,
929 			    flags);
930 			error = rtinit(&ia->ia_ifa, (int)RTM_ADD,
931 			    rtinitflags(ia) | RTF_UP);
932 			if (error == 0)
933 				ia->ia_flags |= IFA_ROUTE;
934 			else
935 				log(LOG_INFO, "in_scrubprefix: err=%d, new prefix add failed\n",
936 					error);
937 			ifa_free(&ia->ia_ifa);
938 			return (error);
939 		}
940 	}
941 	IN_IFADDR_RUNLOCK(&in_ifa_tracker);
942 
943 	/*
944 	 * remove all L2 entries on the given prefix
945 	 */
946 	in_scrubprefixlle(target, 1, flags);
947 
948 	/*
949 	 * As no-one seem to have this prefix, we can remove the route.
950 	 */
951 	error = rtinit(&(target->ia_ifa), (int)RTM_DELETE, rtinitflags(target));
952 	if (error == 0)
953 		target->ia_flags &= ~IFA_ROUTE;
954 	else
955 		log(LOG_INFO, "in_scrubprefix: err=%d, prefix delete failed\n", error);
956 	return (error);
957 }
958 
959 #undef rtinitflags
960 
961 void
962 in_ifscrub_all(void)
963 {
964 	struct ifnet *ifp;
965 	struct ifaddr *ifa, *nifa;
966 	struct ifaliasreq ifr;
967 
968 	IFNET_RLOCK();
969 	CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
970 		/* Cannot lock here - lock recursion. */
971 		/* NET_EPOCH_ENTER(et); */
972 		CK_STAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, nifa) {
973 			if (ifa->ifa_addr->sa_family != AF_INET)
974 				continue;
975 
976 			/*
977 			 * This is ugly but the only way for legacy IP to
978 			 * cleanly remove addresses and everything attached.
979 			 */
980 			bzero(&ifr, sizeof(ifr));
981 			ifr.ifra_addr = *ifa->ifa_addr;
982 			if (ifa->ifa_dstaddr)
983 			ifr.ifra_broadaddr = *ifa->ifa_dstaddr;
984 			(void)in_control(NULL, SIOCDIFADDR, (caddr_t)&ifr,
985 			    ifp, NULL);
986 		}
987 		/* NET_EPOCH_EXIT(et); */
988 		in_purgemaddrs(ifp);
989 		igmp_domifdetach(ifp);
990 	}
991 	IFNET_RUNLOCK();
992 }
993 
994 int
995 in_ifaddr_broadcast(struct in_addr in, struct in_ifaddr *ia)
996 {
997 
998 	return ((in.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
999 	     /*
1000 	      * Check for old-style (host 0) broadcast, but
1001 	      * taking into account that RFC 3021 obsoletes it.
1002 	      */
1003 	    (ia->ia_subnetmask != IN_RFC3021_MASK &&
1004 	    ntohl(in.s_addr) == ia->ia_subnet)) &&
1005 	     /*
1006 	      * Check for an all one subnetmask. These
1007 	      * only exist when an interface gets a secondary
1008 	      * address.
1009 	      */
1010 	    ia->ia_subnetmask != (u_long)0xffffffff);
1011 }
1012 
1013 /*
1014  * Return 1 if the address might be a local broadcast address.
1015  */
1016 int
1017 in_broadcast(struct in_addr in, struct ifnet *ifp)
1018 {
1019 	struct ifaddr *ifa;
1020 	int found;
1021 
1022 	NET_EPOCH_ASSERT();
1023 
1024 	if (in.s_addr == INADDR_BROADCAST ||
1025 	    in.s_addr == INADDR_ANY)
1026 		return (1);
1027 	if ((ifp->if_flags & IFF_BROADCAST) == 0)
1028 		return (0);
1029 	found = 0;
1030 	/*
1031 	 * Look through the list of addresses for a match
1032 	 * with a broadcast address.
1033 	 */
1034 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
1035 		if (ifa->ifa_addr->sa_family == AF_INET &&
1036 		    in_ifaddr_broadcast(in, (struct in_ifaddr *)ifa)) {
1037 			found = 1;
1038 			break;
1039 		}
1040 	return (found);
1041 }
1042 
1043 /*
1044  * On interface removal, clean up IPv4 data structures hung off of the ifnet.
1045  */
1046 void
1047 in_ifdetach(struct ifnet *ifp)
1048 {
1049 	IN_MULTI_LOCK();
1050 	in_pcbpurgeif0(&V_ripcbinfo, ifp);
1051 	in_pcbpurgeif0(&V_udbinfo, ifp);
1052 	in_pcbpurgeif0(&V_ulitecbinfo, ifp);
1053 	in_purgemaddrs(ifp);
1054 	IN_MULTI_UNLOCK();
1055 
1056 	/*
1057 	 * Make sure all multicast deletions invoking if_ioctl() are
1058 	 * completed before returning. Else we risk accessing a freed
1059 	 * ifnet structure pointer.
1060 	 */
1061 	inm_release_wait(NULL);
1062 }
1063 
1064 /*
1065  * Delete all IPv4 multicast address records, and associated link-layer
1066  * multicast address records, associated with ifp.
1067  * XXX It looks like domifdetach runs AFTER the link layer cleanup.
1068  * XXX This should not race with ifma_protospec being set during
1069  * a new allocation, if it does, we have bigger problems.
1070  */
1071 static void
1072 in_purgemaddrs(struct ifnet *ifp)
1073 {
1074 	struct in_multi_head purgeinms;
1075 	struct in_multi		*inm;
1076 	struct ifmultiaddr	*ifma, *next;
1077 
1078 	SLIST_INIT(&purgeinms);
1079 	IN_MULTI_LIST_LOCK();
1080 
1081 	/*
1082 	 * Extract list of in_multi associated with the detaching ifp
1083 	 * which the PF_INET layer is about to release.
1084 	 * We need to do this as IF_ADDR_LOCK() may be re-acquired
1085 	 * by code further down.
1086 	 */
1087 	IF_ADDR_WLOCK(ifp);
1088  restart:
1089 	CK_STAILQ_FOREACH_SAFE(ifma, &ifp->if_multiaddrs, ifma_link, next) {
1090 		if (ifma->ifma_addr->sa_family != AF_INET ||
1091 		    ifma->ifma_protospec == NULL)
1092 			continue;
1093 		inm = (struct in_multi *)ifma->ifma_protospec;
1094 		inm_rele_locked(&purgeinms, inm);
1095 		if (__predict_false(ifma_restart)) {
1096 			ifma_restart = true;
1097 			goto restart;
1098 		}
1099 	}
1100 	IF_ADDR_WUNLOCK(ifp);
1101 
1102 	inm_release_list_deferred(&purgeinms);
1103 	igmp_ifdetach(ifp);
1104 	IN_MULTI_LIST_UNLOCK();
1105 }
1106 
1107 struct in_llentry {
1108 	struct llentry		base;
1109 };
1110 
1111 #define	IN_LLTBL_DEFAULT_HSIZE	32
1112 #define	IN_LLTBL_HASH(k, h) \
1113 	(((((((k >> 8) ^ k) >> 8) ^ k) >> 8) ^ k) & ((h) - 1))
1114 
1115 /*
1116  * Do actual deallocation of @lle.
1117  */
1118 static void
1119 in_lltable_destroy_lle_unlocked(epoch_context_t ctx)
1120 {
1121 	struct llentry *lle;
1122 
1123 	lle = __containerof(ctx, struct llentry, lle_epoch_ctx);
1124 	LLE_LOCK_DESTROY(lle);
1125 	LLE_REQ_DESTROY(lle);
1126 	free(lle, M_LLTABLE);
1127 }
1128 
1129 /*
1130  * Called by the datapath to indicate that
1131  * the entry was used.
1132  */
1133 static void
1134 in_lltable_mark_used(struct llentry *lle)
1135 {
1136 
1137 	LLE_REQ_LOCK(lle);
1138 	lle->r_skip_req = 0;
1139 	LLE_REQ_UNLOCK(lle);
1140 }
1141 
1142 /*
1143  * Called by LLE_FREE_LOCKED when number of references
1144  * drops to zero.
1145  */
1146 static void
1147 in_lltable_destroy_lle(struct llentry *lle)
1148 {
1149 
1150 	LLE_WUNLOCK(lle);
1151 	NET_EPOCH_CALL(in_lltable_destroy_lle_unlocked, &lle->lle_epoch_ctx);
1152 }
1153 
1154 static struct llentry *
1155 in_lltable_new(struct in_addr addr4, u_int flags)
1156 {
1157 	struct in_llentry *lle;
1158 
1159 	lle = malloc(sizeof(struct in_llentry), M_LLTABLE, M_NOWAIT | M_ZERO);
1160 	if (lle == NULL)		/* NB: caller generates msg */
1161 		return NULL;
1162 
1163 	/*
1164 	 * For IPv4 this will trigger "arpresolve" to generate
1165 	 * an ARP request.
1166 	 */
1167 	lle->base.la_expire = time_uptime; /* mark expired */
1168 	lle->base.r_l3addr.addr4 = addr4;
1169 	lle->base.lle_refcnt = 1;
1170 	lle->base.lle_free = in_lltable_destroy_lle;
1171 	LLE_LOCK_INIT(&lle->base);
1172 	LLE_REQ_INIT(&lle->base);
1173 	callout_init(&lle->base.lle_timer, 1);
1174 
1175 	return (&lle->base);
1176 }
1177 
1178 #define IN_ARE_MASKED_ADDR_EQUAL(d, a, m)	(		\
1179 	((((d).s_addr ^ (a).s_addr) & (m).s_addr)) == 0 )
1180 
1181 static int
1182 in_lltable_match_prefix(const struct sockaddr *saddr,
1183     const struct sockaddr *smask, u_int flags, struct llentry *lle)
1184 {
1185 	struct in_addr addr, mask, lle_addr;
1186 
1187 	addr = ((const struct sockaddr_in *)saddr)->sin_addr;
1188 	mask = ((const struct sockaddr_in *)smask)->sin_addr;
1189 	lle_addr.s_addr = ntohl(lle->r_l3addr.addr4.s_addr);
1190 
1191 	if (IN_ARE_MASKED_ADDR_EQUAL(lle_addr, addr, mask) == 0)
1192 		return (0);
1193 
1194 	if (lle->la_flags & LLE_IFADDR) {
1195 		/*
1196 		 * Delete LLE_IFADDR records IFF address & flag matches.
1197 		 * Note that addr is the interface address within prefix
1198 		 * being matched.
1199 		 * Note also we should handle 'ifdown' cases without removing
1200 		 * ifaddr macs.
1201 		 */
1202 		if (addr.s_addr == lle_addr.s_addr && (flags & LLE_STATIC) != 0)
1203 			return (1);
1204 		return (0);
1205 	}
1206 
1207 	/* flags & LLE_STATIC means deleting both dynamic and static entries */
1208 	if ((flags & LLE_STATIC) || !(lle->la_flags & LLE_STATIC))
1209 		return (1);
1210 
1211 	return (0);
1212 }
1213 
1214 static void
1215 in_lltable_free_entry(struct lltable *llt, struct llentry *lle)
1216 {
1217 	size_t pkts_dropped;
1218 
1219 	LLE_WLOCK_ASSERT(lle);
1220 	KASSERT(llt != NULL, ("lltable is NULL"));
1221 
1222 	/* Unlink entry from table if not already */
1223 	if ((lle->la_flags & LLE_LINKED) != 0) {
1224 		IF_AFDATA_WLOCK_ASSERT(llt->llt_ifp);
1225 		lltable_unlink_entry(llt, lle);
1226 	}
1227 
1228 	/* Drop hold queue */
1229 	pkts_dropped = llentry_free(lle);
1230 	ARPSTAT_ADD(dropped, pkts_dropped);
1231 }
1232 
1233 static int
1234 in_lltable_rtcheck(struct ifnet *ifp, u_int flags, const struct sockaddr *l3addr)
1235 {
1236 	struct rt_addrinfo info;
1237 	struct sockaddr_in rt_key, rt_mask;
1238 	struct sockaddr rt_gateway;
1239 	int rt_flags;
1240 
1241 	KASSERT(l3addr->sa_family == AF_INET,
1242 	    ("sin_family %d", l3addr->sa_family));
1243 
1244 	bzero(&rt_key, sizeof(rt_key));
1245 	rt_key.sin_len = sizeof(rt_key);
1246 	bzero(&rt_mask, sizeof(rt_mask));
1247 	rt_mask.sin_len = sizeof(rt_mask);
1248 	bzero(&rt_gateway, sizeof(rt_gateway));
1249 	rt_gateway.sa_len = sizeof(rt_gateway);
1250 
1251 	bzero(&info, sizeof(info));
1252 	info.rti_info[RTAX_DST] = (struct sockaddr *)&rt_key;
1253 	info.rti_info[RTAX_NETMASK] = (struct sockaddr *)&rt_mask;
1254 	info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&rt_gateway;
1255 
1256 	if (rib_lookup_info(ifp->if_fib, l3addr, NHR_REF, 0, &info) != 0)
1257 		return (EINVAL);
1258 
1259 	rt_flags = info.rti_flags;
1260 
1261 	/*
1262 	 * If the gateway for an existing host route matches the target L3
1263 	 * address, which is a special route inserted by some implementation
1264 	 * such as MANET, and the interface is of the correct type, then
1265 	 * allow for ARP to proceed.
1266 	 */
1267 	if (rt_flags & RTF_GATEWAY) {
1268 		if (!(rt_flags & RTF_HOST) || !info.rti_ifp ||
1269 		    info.rti_ifp->if_type != IFT_ETHER ||
1270 		    (info.rti_ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) != 0 ||
1271 		    memcmp(rt_gateway.sa_data, l3addr->sa_data,
1272 		    sizeof(in_addr_t)) != 0) {
1273 			rib_free_info(&info);
1274 			return (EINVAL);
1275 		}
1276 	}
1277 	rib_free_info(&info);
1278 
1279 	/*
1280 	 * Make sure that at least the destination address is covered
1281 	 * by the route. This is for handling the case where 2 or more
1282 	 * interfaces have the same prefix. An incoming packet arrives
1283 	 * on one interface and the corresponding outgoing packet leaves
1284 	 * another interface.
1285 	 */
1286 	if (!(rt_flags & RTF_HOST) && info.rti_ifp != ifp) {
1287 		const char *sa, *mask, *addr, *lim;
1288 		const struct sockaddr_in *l3sin;
1289 
1290 		mask = (const char *)&rt_mask;
1291 		/*
1292 		 * Just being extra cautious to avoid some custom
1293 		 * code getting into trouble.
1294 		 */
1295 		if ((info.rti_addrs & RTA_NETMASK) == 0)
1296 			return (EINVAL);
1297 
1298 		sa = (const char *)&rt_key;
1299 		addr = (const char *)l3addr;
1300 		l3sin = (const struct sockaddr_in *)l3addr;
1301 		lim = addr + l3sin->sin_len;
1302 
1303 		for ( ; addr < lim; sa++, mask++, addr++) {
1304 			if ((*sa ^ *addr) & *mask) {
1305 #ifdef DIAGNOSTIC
1306 				char addrbuf[INET_ADDRSTRLEN];
1307 
1308 				log(LOG_INFO, "IPv4 address: \"%s\" "
1309 				    "is not on the network\n",
1310 				    inet_ntoa_r(l3sin->sin_addr, addrbuf));
1311 #endif
1312 				return (EINVAL);
1313 			}
1314 		}
1315 	}
1316 
1317 	return (0);
1318 }
1319 
1320 static inline uint32_t
1321 in_lltable_hash_dst(const struct in_addr dst, uint32_t hsize)
1322 {
1323 
1324 	return (IN_LLTBL_HASH(dst.s_addr, hsize));
1325 }
1326 
1327 static uint32_t
1328 in_lltable_hash(const struct llentry *lle, uint32_t hsize)
1329 {
1330 
1331 	return (in_lltable_hash_dst(lle->r_l3addr.addr4, hsize));
1332 }
1333 
1334 static void
1335 in_lltable_fill_sa_entry(const struct llentry *lle, struct sockaddr *sa)
1336 {
1337 	struct sockaddr_in *sin;
1338 
1339 	sin = (struct sockaddr_in *)sa;
1340 	bzero(sin, sizeof(*sin));
1341 	sin->sin_family = AF_INET;
1342 	sin->sin_len = sizeof(*sin);
1343 	sin->sin_addr = lle->r_l3addr.addr4;
1344 }
1345 
1346 static inline struct llentry *
1347 in_lltable_find_dst(struct lltable *llt, struct in_addr dst)
1348 {
1349 	struct llentry *lle;
1350 	struct llentries *lleh;
1351 	u_int hashidx;
1352 
1353 	hashidx = in_lltable_hash_dst(dst, llt->llt_hsize);
1354 	lleh = &llt->lle_head[hashidx];
1355 	CK_LIST_FOREACH(lle, lleh, lle_next) {
1356 		if (lle->la_flags & LLE_DELETED)
1357 			continue;
1358 		if (lle->r_l3addr.addr4.s_addr == dst.s_addr)
1359 			break;
1360 	}
1361 
1362 	return (lle);
1363 }
1364 
1365 static void
1366 in_lltable_delete_entry(struct lltable *llt, struct llentry *lle)
1367 {
1368 
1369 	lle->la_flags |= LLE_DELETED;
1370 	EVENTHANDLER_INVOKE(lle_event, lle, LLENTRY_DELETED);
1371 #ifdef DIAGNOSTIC
1372 	log(LOG_INFO, "ifaddr cache = %p is deleted\n", lle);
1373 #endif
1374 	llentry_free(lle);
1375 }
1376 
1377 static struct llentry *
1378 in_lltable_alloc(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
1379 {
1380 	const struct sockaddr_in *sin = (const struct sockaddr_in *)l3addr;
1381 	struct ifnet *ifp = llt->llt_ifp;
1382 	struct llentry *lle;
1383 	char linkhdr[LLE_MAX_LINKHDR];
1384 	size_t linkhdrsize;
1385 	int lladdr_off;
1386 
1387 	KASSERT(l3addr->sa_family == AF_INET,
1388 	    ("sin_family %d", l3addr->sa_family));
1389 
1390 	/*
1391 	 * A route that covers the given address must have
1392 	 * been installed 1st because we are doing a resolution,
1393 	 * verify this.
1394 	 */
1395 	if (!(flags & LLE_IFADDR) &&
1396 	    in_lltable_rtcheck(ifp, flags, l3addr) != 0)
1397 		return (NULL);
1398 
1399 	lle = in_lltable_new(sin->sin_addr, flags);
1400 	if (lle == NULL) {
1401 		log(LOG_INFO, "lla_lookup: new lle malloc failed\n");
1402 		return (NULL);
1403 	}
1404 	lle->la_flags = flags;
1405 	if (flags & LLE_STATIC)
1406 		lle->r_flags |= RLLE_VALID;
1407 	if ((flags & LLE_IFADDR) == LLE_IFADDR) {
1408 		linkhdrsize = LLE_MAX_LINKHDR;
1409 		if (lltable_calc_llheader(ifp, AF_INET, IF_LLADDR(ifp),
1410 		    linkhdr, &linkhdrsize, &lladdr_off) != 0) {
1411 			NET_EPOCH_CALL(in_lltable_destroy_lle_unlocked, &lle->lle_epoch_ctx);
1412 			return (NULL);
1413 		}
1414 		lltable_set_entry_addr(ifp, lle, linkhdr, linkhdrsize,
1415 		    lladdr_off);
1416 		lle->la_flags |= LLE_STATIC;
1417 		lle->r_flags |= (RLLE_VALID | RLLE_IFADDR);
1418 	}
1419 
1420 	return (lle);
1421 }
1422 
1423 /*
1424  * Return NULL if not found or marked for deletion.
1425  * If found return lle read locked.
1426  */
1427 static struct llentry *
1428 in_lltable_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
1429 {
1430 	const struct sockaddr_in *sin = (const struct sockaddr_in *)l3addr;
1431 	struct llentry *lle;
1432 
1433 	IF_AFDATA_LOCK_ASSERT(llt->llt_ifp);
1434 	KASSERT(l3addr->sa_family == AF_INET,
1435 	    ("sin_family %d", l3addr->sa_family));
1436 	KASSERT((flags & (LLE_UNLOCKED | LLE_EXCLUSIVE)) !=
1437 	    (LLE_UNLOCKED | LLE_EXCLUSIVE),
1438 	    ("wrong lle request flags: %#x", flags));
1439 
1440 	lle = in_lltable_find_dst(llt, sin->sin_addr);
1441 	if (lle == NULL)
1442 		return (NULL);
1443 	if (flags & LLE_UNLOCKED)
1444 		return (lle);
1445 
1446 	if (flags & LLE_EXCLUSIVE)
1447 		LLE_WLOCK(lle);
1448 	else
1449 		LLE_RLOCK(lle);
1450 
1451 	/*
1452 	 * If the afdata lock is not held, the LLE may have been unlinked while
1453 	 * we were blocked on the LLE lock.  Check for this case.
1454 	 */
1455 	if (__predict_false((lle->la_flags & LLE_LINKED) == 0)) {
1456 		if (flags & LLE_EXCLUSIVE)
1457 			LLE_WUNLOCK(lle);
1458 		else
1459 			LLE_RUNLOCK(lle);
1460 		return (NULL);
1461 	}
1462 	return (lle);
1463 }
1464 
1465 static int
1466 in_lltable_dump_entry(struct lltable *llt, struct llentry *lle,
1467     struct sysctl_req *wr)
1468 {
1469 	struct ifnet *ifp = llt->llt_ifp;
1470 	/* XXX stack use */
1471 	struct {
1472 		struct rt_msghdr	rtm;
1473 		struct sockaddr_in	sin;
1474 		struct sockaddr_dl	sdl;
1475 	} arpc;
1476 	struct sockaddr_dl *sdl;
1477 	int error;
1478 
1479 	bzero(&arpc, sizeof(arpc));
1480 	/* skip deleted entries */
1481 	if ((lle->la_flags & LLE_DELETED) == LLE_DELETED)
1482 		return (0);
1483 	/* Skip if jailed and not a valid IP of the prison. */
1484 	lltable_fill_sa_entry(lle,(struct sockaddr *)&arpc.sin);
1485 	if (prison_if(wr->td->td_ucred, (struct sockaddr *)&arpc.sin) != 0)
1486 		return (0);
1487 	/*
1488 	 * produce a msg made of:
1489 	 *  struct rt_msghdr;
1490 	 *  struct sockaddr_in; (IPv4)
1491 	 *  struct sockaddr_dl;
1492 	 */
1493 	arpc.rtm.rtm_msglen = sizeof(arpc);
1494 	arpc.rtm.rtm_version = RTM_VERSION;
1495 	arpc.rtm.rtm_type = RTM_GET;
1496 	arpc.rtm.rtm_flags = RTF_UP;
1497 	arpc.rtm.rtm_addrs = RTA_DST | RTA_GATEWAY;
1498 
1499 	/* publish */
1500 	if (lle->la_flags & LLE_PUB)
1501 		arpc.rtm.rtm_flags |= RTF_ANNOUNCE;
1502 
1503 	sdl = &arpc.sdl;
1504 	sdl->sdl_family = AF_LINK;
1505 	sdl->sdl_len = sizeof(*sdl);
1506 	sdl->sdl_index = ifp->if_index;
1507 	sdl->sdl_type = ifp->if_type;
1508 	if ((lle->la_flags & LLE_VALID) == LLE_VALID) {
1509 		sdl->sdl_alen = ifp->if_addrlen;
1510 		bcopy(lle->ll_addr, LLADDR(sdl), ifp->if_addrlen);
1511 	} else {
1512 		sdl->sdl_alen = 0;
1513 		bzero(LLADDR(sdl), ifp->if_addrlen);
1514 	}
1515 
1516 	arpc.rtm.rtm_rmx.rmx_expire =
1517 	    lle->la_flags & LLE_STATIC ? 0 : lle->la_expire;
1518 	arpc.rtm.rtm_flags |= (RTF_HOST | RTF_LLDATA);
1519 	if (lle->la_flags & LLE_STATIC)
1520 		arpc.rtm.rtm_flags |= RTF_STATIC;
1521 	if (lle->la_flags & LLE_IFADDR)
1522 		arpc.rtm.rtm_flags |= RTF_PINNED;
1523 	arpc.rtm.rtm_index = ifp->if_index;
1524 	error = SYSCTL_OUT(wr, &arpc, sizeof(arpc));
1525 
1526 	return (error);
1527 }
1528 
1529 static struct lltable *
1530 in_lltattach(struct ifnet *ifp)
1531 {
1532 	struct lltable *llt;
1533 
1534 	llt = lltable_allocate_htbl(IN_LLTBL_DEFAULT_HSIZE);
1535  	llt->llt_af = AF_INET;
1536  	llt->llt_ifp = ifp;
1537 
1538 	llt->llt_lookup = in_lltable_lookup;
1539 	llt->llt_alloc_entry = in_lltable_alloc;
1540 	llt->llt_delete_entry = in_lltable_delete_entry;
1541 	llt->llt_dump_entry = in_lltable_dump_entry;
1542 	llt->llt_hash = in_lltable_hash;
1543 	llt->llt_fill_sa_entry = in_lltable_fill_sa_entry;
1544 	llt->llt_free_entry = in_lltable_free_entry;
1545 	llt->llt_match_prefix = in_lltable_match_prefix;
1546 	llt->llt_mark_used = in_lltable_mark_used;
1547  	lltable_link(llt);
1548 
1549 	return (llt);
1550 }
1551 
1552 void *
1553 in_domifattach(struct ifnet *ifp)
1554 {
1555 	struct in_ifinfo *ii;
1556 
1557 	ii = malloc(sizeof(struct in_ifinfo), M_IFADDR, M_WAITOK|M_ZERO);
1558 
1559 	ii->ii_llt = in_lltattach(ifp);
1560 	ii->ii_igmp = igmp_domifattach(ifp);
1561 
1562 	return (ii);
1563 }
1564 
1565 void
1566 in_domifdetach(struct ifnet *ifp, void *aux)
1567 {
1568 	struct in_ifinfo *ii = (struct in_ifinfo *)aux;
1569 
1570 	igmp_domifdetach(ifp);
1571 	lltable_free(ii->ii_llt);
1572 	free(ii, M_IFADDR);
1573 }
1574