xref: /freebsd/sys/netinet/in.c (revision 10b59a9b4add0320d52c15ce057dd697261e7dfc)
1 /*-
2  * Copyright (c) 1982, 1986, 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  * Copyright (C) 2001 WIDE Project.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 4. Neither the name of the University nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  *	@(#)in.c	8.4 (Berkeley) 1/9/95
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include "opt_mpath.h"
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/sockio.h>
41 #include <sys/malloc.h>
42 #include <sys/priv.h>
43 #include <sys/socket.h>
44 #include <sys/jail.h>
45 #include <sys/kernel.h>
46 #include <sys/proc.h>
47 #include <sys/sysctl.h>
48 #include <sys/syslog.h>
49 
50 #include <net/if.h>
51 #include <net/if_var.h>
52 #include <net/if_arp.h>
53 #include <net/if_dl.h>
54 #include <net/if_llatbl.h>
55 #include <net/if_types.h>
56 #include <net/route.h>
57 #include <net/vnet.h>
58 
59 #include <netinet/in.h>
60 #include <netinet/in_var.h>
61 #include <netinet/in_pcb.h>
62 #include <netinet/ip_var.h>
63 #include <netinet/igmp_var.h>
64 #include <netinet/udp.h>
65 #include <netinet/udp_var.h>
66 
67 static int in_mask2len(struct in_addr *);
68 static void in_len2mask(struct in_addr *, int);
69 static int in_lifaddr_ioctl(struct socket *, u_long, caddr_t,
70 	struct ifnet *, struct thread *);
71 
72 static int	in_addprefix(struct in_ifaddr *, int);
73 static int	in_scrubprefix(struct in_ifaddr *, u_int);
74 static void	in_socktrim(struct sockaddr_in *);
75 static int	in_ifinit(struct ifnet *,
76 	    struct in_ifaddr *, struct sockaddr_in *, int);
77 static void	in_purgemaddrs(struct ifnet *);
78 
79 static VNET_DEFINE(int, sameprefixcarponly);
80 #define	V_sameprefixcarponly		VNET(sameprefixcarponly)
81 SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, same_prefix_carp_only, CTLFLAG_RW,
82 	&VNET_NAME(sameprefixcarponly), 0,
83 	"Refuse to create same prefixes on different interfaces");
84 
85 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
86 #define	V_ripcbinfo			VNET(ripcbinfo)
87 
88 VNET_DECLARE(struct arpstat, arpstat);  /* ARP statistics, see if_arp.h */
89 #define	V_arpstat		VNET(arpstat)
90 
91 /*
92  * Return 1 if an internet address is for a ``local'' host
93  * (one to which we have a connection).
94  */
95 int
96 in_localaddr(struct in_addr in)
97 {
98 	register u_long i = ntohl(in.s_addr);
99 	register struct in_ifaddr *ia;
100 
101 	IN_IFADDR_RLOCK();
102 	TAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
103 		if ((i & ia->ia_subnetmask) == ia->ia_subnet) {
104 			IN_IFADDR_RUNLOCK();
105 			return (1);
106 		}
107 	}
108 	IN_IFADDR_RUNLOCK();
109 	return (0);
110 }
111 
112 /*
113  * Return 1 if an internet address is for the local host and configured
114  * on one of its interfaces.
115  */
116 int
117 in_localip(struct in_addr in)
118 {
119 	struct in_ifaddr *ia;
120 
121 	IN_IFADDR_RLOCK();
122 	LIST_FOREACH(ia, INADDR_HASH(in.s_addr), ia_hash) {
123 		if (IA_SIN(ia)->sin_addr.s_addr == in.s_addr) {
124 			IN_IFADDR_RUNLOCK();
125 			return (1);
126 		}
127 	}
128 	IN_IFADDR_RUNLOCK();
129 	return (0);
130 }
131 
132 /*
133  * Determine whether an IP address is in a reserved set of addresses
134  * that may not be forwarded, or whether datagrams to that destination
135  * may be forwarded.
136  */
137 int
138 in_canforward(struct in_addr in)
139 {
140 	register u_long i = ntohl(in.s_addr);
141 	register u_long net;
142 
143 	if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i) || IN_LINKLOCAL(i))
144 		return (0);
145 	if (IN_CLASSA(i)) {
146 		net = i & IN_CLASSA_NET;
147 		if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
148 			return (0);
149 	}
150 	return (1);
151 }
152 
153 /*
154  * Trim a mask in a sockaddr
155  */
156 static void
157 in_socktrim(struct sockaddr_in *ap)
158 {
159     register char *cplim = (char *) &ap->sin_addr;
160     register char *cp = (char *) (&ap->sin_addr + 1);
161 
162     ap->sin_len = 0;
163     while (--cp >= cplim)
164 	if (*cp) {
165 	    (ap)->sin_len = cp - (char *) (ap) + 1;
166 	    break;
167 	}
168 }
169 
170 static int
171 in_mask2len(mask)
172 	struct in_addr *mask;
173 {
174 	int x, y;
175 	u_char *p;
176 
177 	p = (u_char *)mask;
178 	for (x = 0; x < sizeof(*mask); x++) {
179 		if (p[x] != 0xff)
180 			break;
181 	}
182 	y = 0;
183 	if (x < sizeof(*mask)) {
184 		for (y = 0; y < 8; y++) {
185 			if ((p[x] & (0x80 >> y)) == 0)
186 				break;
187 		}
188 	}
189 	return (x * 8 + y);
190 }
191 
192 static void
193 in_len2mask(struct in_addr *mask, int len)
194 {
195 	int i;
196 	u_char *p;
197 
198 	p = (u_char *)mask;
199 	bzero(mask, sizeof(*mask));
200 	for (i = 0; i < len / 8; i++)
201 		p[i] = 0xff;
202 	if (len % 8)
203 		p[i] = (0xff00 >> (len % 8)) & 0xff;
204 }
205 
206 /*
207  * Generic internet control operations (ioctl's).
208  *
209  * ifp is NULL if not an interface-specific ioctl.
210  */
211 /* ARGSUSED */
212 int
213 in_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
214     struct thread *td)
215 {
216 	register struct ifreq *ifr = (struct ifreq *)data;
217 	register struct in_ifaddr *ia, *iap;
218 	register struct ifaddr *ifa;
219 	struct in_addr allhosts_addr;
220 	struct in_addr dst;
221 	struct in_ifinfo *ii;
222 	struct in_aliasreq *ifra = (struct in_aliasreq *)data;
223 	struct sockaddr_in oldaddr;
224 	int error, hostIsNew, iaIsNew, maskIsNew;
225 	int iaIsFirst;
226 
227 	ia = NULL;
228 	iaIsFirst = 0;
229 	iaIsNew = 0;
230 	allhosts_addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
231 
232 	/*
233 	 * Filter out ioctls we implement directly; forward the rest on to
234 	 * in_lifaddr_ioctl() and ifp->if_ioctl().
235 	 */
236 	switch (cmd) {
237 	case SIOCAIFADDR:
238 	case SIOCDIFADDR:
239 	case SIOCGIFADDR:
240 	case SIOCGIFBRDADDR:
241 	case SIOCGIFDSTADDR:
242 	case SIOCGIFNETMASK:
243 	case SIOCSIFADDR:
244 	case SIOCSIFBRDADDR:
245 	case SIOCSIFDSTADDR:
246 	case SIOCSIFNETMASK:
247 		break;
248 
249 	case SIOCALIFADDR:
250 		if (td != NULL) {
251 			error = priv_check(td, PRIV_NET_ADDIFADDR);
252 			if (error)
253 				return (error);
254 		}
255 		if (ifp == NULL)
256 			return (EINVAL);
257 		return in_lifaddr_ioctl(so, cmd, data, ifp, td);
258 
259 	case SIOCDLIFADDR:
260 		if (td != NULL) {
261 			error = priv_check(td, PRIV_NET_DELIFADDR);
262 			if (error)
263 				return (error);
264 		}
265 		if (ifp == NULL)
266 			return (EINVAL);
267 		return in_lifaddr_ioctl(so, cmd, data, ifp, td);
268 
269 	case SIOCGLIFADDR:
270 		if (ifp == NULL)
271 			return (EINVAL);
272 		return in_lifaddr_ioctl(so, cmd, data, ifp, td);
273 
274 	default:
275 		if (ifp == NULL || ifp->if_ioctl == NULL)
276 			return (EOPNOTSUPP);
277 		return ((*ifp->if_ioctl)(ifp, cmd, data));
278 	}
279 
280 	if (ifp == NULL)
281 		return (EADDRNOTAVAIL);
282 
283 	/*
284 	 * Security checks before we get involved in any work.
285 	 */
286 	switch (cmd) {
287 	case SIOCAIFADDR:
288 	case SIOCSIFADDR:
289 	case SIOCSIFBRDADDR:
290 	case SIOCSIFNETMASK:
291 	case SIOCSIFDSTADDR:
292 		if (td != NULL) {
293 			error = priv_check(td, PRIV_NET_ADDIFADDR);
294 			if (error)
295 				return (error);
296 		}
297 		break;
298 
299 	case SIOCDIFADDR:
300 		if (td != NULL) {
301 			error = priv_check(td, PRIV_NET_DELIFADDR);
302 			if (error)
303 				return (error);
304 		}
305 		break;
306 	}
307 
308 	/*
309 	 * Find address for this interface, if it exists.
310 	 *
311 	 * If an alias address was specified, find that one instead of the
312 	 * first one on the interface, if possible.
313 	 */
314 	dst = ((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr;
315 	IN_IFADDR_RLOCK();
316 	LIST_FOREACH(iap, INADDR_HASH(dst.s_addr), ia_hash) {
317 		if (iap->ia_ifp == ifp &&
318 		    iap->ia_addr.sin_addr.s_addr == dst.s_addr) {
319 			if (td == NULL || prison_check_ip4(td->td_ucred,
320 			    &dst) == 0)
321 				ia = iap;
322 			break;
323 		}
324 	}
325 	if (ia != NULL)
326 		ifa_ref(&ia->ia_ifa);
327 	IN_IFADDR_RUNLOCK();
328 	if (ia == NULL) {
329 		IF_ADDR_LOCK(ifp);
330 		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
331 			iap = ifatoia(ifa);
332 			if (iap->ia_addr.sin_family == AF_INET) {
333 				if (td != NULL &&
334 				    prison_check_ip4(td->td_ucred,
335 				    &iap->ia_addr.sin_addr) != 0)
336 					continue;
337 				ia = iap;
338 				break;
339 			}
340 		}
341 		if (ia != NULL)
342 			ifa_ref(&ia->ia_ifa);
343 		IF_ADDR_UNLOCK(ifp);
344 	}
345 	if (ia == NULL)
346 		iaIsFirst = 1;
347 
348 	error = 0;
349 	switch (cmd) {
350 	case SIOCAIFADDR:
351 	case SIOCDIFADDR:
352 		if (ifra->ifra_addr.sin_family == AF_INET) {
353 			struct in_ifaddr *oia;
354 
355 			IN_IFADDR_RLOCK();
356 			for (oia = ia; ia; ia = TAILQ_NEXT(ia, ia_link)) {
357 				if (ia->ia_ifp == ifp  &&
358 				    ia->ia_addr.sin_addr.s_addr ==
359 				    ifra->ifra_addr.sin_addr.s_addr)
360 					break;
361 			}
362 			if (ia != NULL && ia != oia)
363 				ifa_ref(&ia->ia_ifa);
364 			if (oia != NULL && ia != oia)
365 				ifa_free(&oia->ia_ifa);
366 			IN_IFADDR_RUNLOCK();
367 			if ((ifp->if_flags & IFF_POINTOPOINT)
368 			    && (cmd == SIOCAIFADDR)
369 			    && (ifra->ifra_dstaddr.sin_addr.s_addr
370 				== INADDR_ANY)) {
371 				error = EDESTADDRREQ;
372 				goto out;
373 			}
374 		}
375 		if (cmd == SIOCDIFADDR && ia == NULL) {
376 			error = EADDRNOTAVAIL;
377 			goto out;
378 		}
379 		/* FALLTHROUGH */
380 	case SIOCSIFADDR:
381 	case SIOCSIFNETMASK:
382 	case SIOCSIFDSTADDR:
383 		if (ia == NULL) {
384 			ia = (struct in_ifaddr *)
385 				malloc(sizeof *ia, M_IFADDR, M_NOWAIT |
386 				    M_ZERO);
387 			if (ia == NULL) {
388 				error = ENOBUFS;
389 				goto out;
390 			}
391 
392 			ifa = &ia->ia_ifa;
393 			ifa_init(ifa);
394 			ifa->ifa_addr = (struct sockaddr *)&ia->ia_addr;
395 			ifa->ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr;
396 			ifa->ifa_netmask = (struct sockaddr *)&ia->ia_sockmask;
397 
398 			ia->ia_sockmask.sin_len = 8;
399 			ia->ia_sockmask.sin_family = AF_INET;
400 			if (ifp->if_flags & IFF_BROADCAST) {
401 				ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr);
402 				ia->ia_broadaddr.sin_family = AF_INET;
403 			}
404 			ia->ia_ifp = ifp;
405 
406 			ifa_ref(ifa);			/* if_addrhead */
407 			IF_ADDR_LOCK(ifp);
408 			TAILQ_INSERT_TAIL(&ifp->if_addrhead, ifa, ifa_link);
409 			IF_ADDR_UNLOCK(ifp);
410 			ifa_ref(ifa);			/* in_ifaddrhead */
411 			IN_IFADDR_WLOCK();
412 			TAILQ_INSERT_TAIL(&V_in_ifaddrhead, ia, ia_link);
413 			IN_IFADDR_WUNLOCK();
414 			iaIsNew = 1;
415 		}
416 		break;
417 
418 	case SIOCSIFBRDADDR:
419 	case SIOCGIFADDR:
420 	case SIOCGIFNETMASK:
421 	case SIOCGIFDSTADDR:
422 	case SIOCGIFBRDADDR:
423 		if (ia == NULL) {
424 			error = EADDRNOTAVAIL;
425 			goto out;
426 		}
427 		break;
428 	}
429 
430 	/*
431 	 * Most paths in this switch return directly or via out.  Only paths
432 	 * that remove the address break in order to hit common removal code.
433 	 */
434 	switch (cmd) {
435 	case SIOCGIFADDR:
436 		*((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr;
437 		goto out;
438 
439 	case SIOCGIFBRDADDR:
440 		if ((ifp->if_flags & IFF_BROADCAST) == 0) {
441 			error = EINVAL;
442 			goto out;
443 		}
444 		*((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr;
445 		goto out;
446 
447 	case SIOCGIFDSTADDR:
448 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0) {
449 			error = EINVAL;
450 			goto out;
451 		}
452 		*((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr;
453 		goto out;
454 
455 	case SIOCGIFNETMASK:
456 		*((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask;
457 		goto out;
458 
459 	case SIOCSIFDSTADDR:
460 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0) {
461 			error = EINVAL;
462 			goto out;
463 		}
464 		oldaddr = ia->ia_dstaddr;
465 		ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr;
466 		if (ifp->if_ioctl != NULL) {
467 			error = (*ifp->if_ioctl)(ifp, SIOCSIFDSTADDR,
468 			    (caddr_t)ia);
469 			if (error) {
470 				ia->ia_dstaddr = oldaddr;
471 				goto out;
472 			}
473 		}
474 		if (ia->ia_flags & IFA_ROUTE) {
475 			ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr;
476 			rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
477 			ia->ia_ifa.ifa_dstaddr =
478 					(struct sockaddr *)&ia->ia_dstaddr;
479 			rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP);
480 		}
481 		goto out;
482 
483 	case SIOCSIFBRDADDR:
484 		if ((ifp->if_flags & IFF_BROADCAST) == 0) {
485 			error = EINVAL;
486 			goto out;
487 		}
488 		ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr;
489 		goto out;
490 
491 	case SIOCSIFADDR:
492 		error = in_ifinit(ifp, ia,
493 		    (struct sockaddr_in *) &ifr->ifr_addr, 1);
494 		if (error != 0 && iaIsNew)
495 			break;
496 		if (error == 0) {
497 			ii = ((struct in_ifinfo *)ifp->if_afdata[AF_INET]);
498 			if (iaIsFirst &&
499 			    (ifp->if_flags & IFF_MULTICAST) != 0) {
500 				error = in_joingroup(ifp, &allhosts_addr,
501 				    NULL, &ii->ii_allhosts);
502 			}
503 			EVENTHANDLER_INVOKE(ifaddr_event, ifp);
504 		}
505 		error = 0;
506 		goto out;
507 
508 	case SIOCSIFNETMASK:
509 		ia->ia_sockmask.sin_addr = ifra->ifra_addr.sin_addr;
510 		ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr);
511 		goto out;
512 
513 	case SIOCAIFADDR:
514 		maskIsNew = 0;
515 		hostIsNew = 1;
516 		error = 0;
517 		if (ia->ia_addr.sin_family == AF_INET) {
518 			if (ifra->ifra_addr.sin_len == 0) {
519 				ifra->ifra_addr = ia->ia_addr;
520 				hostIsNew = 0;
521 			} else if (ifra->ifra_addr.sin_addr.s_addr ==
522 					       ia->ia_addr.sin_addr.s_addr)
523 				hostIsNew = 0;
524 		}
525 		if (ifra->ifra_mask.sin_len) {
526 			/*
527 			 * QL: XXX
528 			 * Need to scrub the prefix here in case
529 			 * the issued command is SIOCAIFADDR with
530 			 * the same address, but with a different
531 			 * prefix length. And if the prefix length
532 			 * is the same as before, then the call is
533 			 * un-necessarily executed here.
534 			 */
535 			in_ifscrub(ifp, ia, LLE_STATIC);
536 			ia->ia_sockmask = ifra->ifra_mask;
537 			ia->ia_sockmask.sin_family = AF_INET;
538 			ia->ia_subnetmask =
539 			     ntohl(ia->ia_sockmask.sin_addr.s_addr);
540 			maskIsNew = 1;
541 		}
542 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
543 		    (ifra->ifra_dstaddr.sin_family == AF_INET)) {
544 			in_ifscrub(ifp, ia, LLE_STATIC);
545 			ia->ia_dstaddr = ifra->ifra_dstaddr;
546 			maskIsNew  = 1; /* We lie; but the effect's the same */
547 		}
548 		if (ifra->ifra_addr.sin_family == AF_INET &&
549 		    (hostIsNew || maskIsNew))
550 			error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
551 		if (error != 0 && iaIsNew)
552 			break;
553 
554 		if ((ifp->if_flags & IFF_BROADCAST) &&
555 		    (ifra->ifra_broadaddr.sin_family == AF_INET))
556 			ia->ia_broadaddr = ifra->ifra_broadaddr;
557 		if (error == 0) {
558 			ii = ((struct in_ifinfo *)ifp->if_afdata[AF_INET]);
559 			if (iaIsFirst &&
560 			    (ifp->if_flags & IFF_MULTICAST) != 0) {
561 				error = in_joingroup(ifp, &allhosts_addr,
562 				    NULL, &ii->ii_allhosts);
563 			}
564 			EVENTHANDLER_INVOKE(ifaddr_event, ifp);
565 		}
566 		goto out;
567 
568 	case SIOCDIFADDR:
569 		/*
570 		 * in_ifscrub kills the interface route.
571 		 */
572 		in_ifscrub(ifp, ia, LLE_STATIC);
573 
574 		/*
575 		 * in_ifadown gets rid of all the rest of
576 		 * the routes.  This is not quite the right
577 		 * thing to do, but at least if we are running
578 		 * a routing process they will come back.
579 		 */
580 		in_ifadown(&ia->ia_ifa, 1);
581 		EVENTHANDLER_INVOKE(ifaddr_event, ifp);
582 		error = 0;
583 		break;
584 
585 	default:
586 		panic("in_control: unsupported ioctl");
587 	}
588 
589 	IF_ADDR_LOCK(ifp);
590 	/* Re-check that ia is still part of the list. */
591 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
592 		if (ifa == &ia->ia_ifa)
593 			break;
594 	}
595 	if (ifa == NULL) {
596 		/*
597 		 * If we lost the race with another thread, there is no need to
598 		 * try it again for the next loop as there is no other exit
599 		 * path between here and out.
600 		 */
601 		IF_ADDR_UNLOCK(ifp);
602 		error = EADDRNOTAVAIL;
603 		goto out;
604 	}
605 	TAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifa_link);
606 	IF_ADDR_UNLOCK(ifp);
607 	ifa_free(&ia->ia_ifa);				/* if_addrhead */
608 
609 	IN_IFADDR_WLOCK();
610 	TAILQ_REMOVE(&V_in_ifaddrhead, ia, ia_link);
611 	if (ia->ia_addr.sin_family == AF_INET) {
612 		struct in_ifaddr *if_ia;
613 
614 		LIST_REMOVE(ia, ia_hash);
615 		IN_IFADDR_WUNLOCK();
616 		/*
617 		 * If this is the last IPv4 address configured on this
618 		 * interface, leave the all-hosts group.
619 		 * No state-change report need be transmitted.
620 		 */
621 		if_ia = NULL;
622 		IFP_TO_IA(ifp, if_ia);
623 		if (if_ia == NULL) {
624 			ii = ((struct in_ifinfo *)ifp->if_afdata[AF_INET]);
625 			IN_MULTI_LOCK();
626 			if (ii->ii_allhosts) {
627 				(void)in_leavegroup_locked(ii->ii_allhosts,
628 				    NULL);
629 				ii->ii_allhosts = NULL;
630 			}
631 			IN_MULTI_UNLOCK();
632 		} else
633 			ifa_free(&if_ia->ia_ifa);
634 	} else
635 		IN_IFADDR_WUNLOCK();
636 	ifa_free(&ia->ia_ifa);				/* in_ifaddrhead */
637 out:
638 	if (ia != NULL)
639 		ifa_free(&ia->ia_ifa);
640 	return (error);
641 }
642 
643 /*
644  * SIOC[GAD]LIFADDR.
645  *	SIOCGLIFADDR: get first address. (?!?)
646  *	SIOCGLIFADDR with IFLR_PREFIX:
647  *		get first address that matches the specified prefix.
648  *	SIOCALIFADDR: add the specified address.
649  *	SIOCALIFADDR with IFLR_PREFIX:
650  *		EINVAL since we can't deduce hostid part of the address.
651  *	SIOCDLIFADDR: delete the specified address.
652  *	SIOCDLIFADDR with IFLR_PREFIX:
653  *		delete the first address that matches the specified prefix.
654  * return values:
655  *	EINVAL on invalid parameters
656  *	EADDRNOTAVAIL on prefix match failed/specified address not found
657  *	other values may be returned from in_ioctl()
658  */
659 static int
660 in_lifaddr_ioctl(struct socket *so, u_long cmd, caddr_t data,
661     struct ifnet *ifp, struct thread *td)
662 {
663 	struct if_laddrreq *iflr = (struct if_laddrreq *)data;
664 	struct ifaddr *ifa;
665 
666 	/* sanity checks */
667 	if (data == NULL || ifp == NULL) {
668 		panic("invalid argument to in_lifaddr_ioctl");
669 		/*NOTRECHED*/
670 	}
671 
672 	switch (cmd) {
673 	case SIOCGLIFADDR:
674 		/* address must be specified on GET with IFLR_PREFIX */
675 		if ((iflr->flags & IFLR_PREFIX) == 0)
676 			break;
677 		/*FALLTHROUGH*/
678 	case SIOCALIFADDR:
679 	case SIOCDLIFADDR:
680 		/* address must be specified on ADD and DELETE */
681 		if (iflr->addr.ss_family != AF_INET)
682 			return (EINVAL);
683 		if (iflr->addr.ss_len != sizeof(struct sockaddr_in))
684 			return (EINVAL);
685 		/* XXX need improvement */
686 		if (iflr->dstaddr.ss_family
687 		 && iflr->dstaddr.ss_family != AF_INET)
688 			return (EINVAL);
689 		if (iflr->dstaddr.ss_family
690 		 && iflr->dstaddr.ss_len != sizeof(struct sockaddr_in))
691 			return (EINVAL);
692 		break;
693 	default: /*shouldn't happen*/
694 		return (EOPNOTSUPP);
695 	}
696 	if (sizeof(struct in_addr) * 8 < iflr->prefixlen)
697 		return (EINVAL);
698 
699 	switch (cmd) {
700 	case SIOCALIFADDR:
701 	    {
702 		struct in_aliasreq ifra;
703 
704 		if (iflr->flags & IFLR_PREFIX)
705 			return (EINVAL);
706 
707 		/* copy args to in_aliasreq, perform ioctl(SIOCAIFADDR_IN6). */
708 		bzero(&ifra, sizeof(ifra));
709 		bcopy(iflr->iflr_name, ifra.ifra_name,
710 			sizeof(ifra.ifra_name));
711 
712 		bcopy(&iflr->addr, &ifra.ifra_addr, iflr->addr.ss_len);
713 
714 		if (iflr->dstaddr.ss_family) {	/*XXX*/
715 			bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
716 				iflr->dstaddr.ss_len);
717 		}
718 
719 		ifra.ifra_mask.sin_family = AF_INET;
720 		ifra.ifra_mask.sin_len = sizeof(struct sockaddr_in);
721 		in_len2mask(&ifra.ifra_mask.sin_addr, iflr->prefixlen);
722 
723 		return (in_control(so, SIOCAIFADDR, (caddr_t)&ifra, ifp, td));
724 	    }
725 	case SIOCGLIFADDR:
726 	case SIOCDLIFADDR:
727 	    {
728 		struct in_ifaddr *ia;
729 		struct in_addr mask, candidate, match;
730 		struct sockaddr_in *sin;
731 
732 		bzero(&mask, sizeof(mask));
733 		bzero(&match, sizeof(match));
734 		if (iflr->flags & IFLR_PREFIX) {
735 			/* lookup a prefix rather than address. */
736 			in_len2mask(&mask, iflr->prefixlen);
737 
738 			sin = (struct sockaddr_in *)&iflr->addr;
739 			match.s_addr = sin->sin_addr.s_addr;
740 			match.s_addr &= mask.s_addr;
741 
742 			/* if you set extra bits, that's wrong */
743 			if (match.s_addr != sin->sin_addr.s_addr)
744 				return (EINVAL);
745 
746 		} else {
747 			/* on getting an address, take the 1st match */
748 			/* on deleting an address, do exact match */
749 			if (cmd != SIOCGLIFADDR) {
750 				in_len2mask(&mask, 32);
751 				sin = (struct sockaddr_in *)&iflr->addr;
752 				match.s_addr = sin->sin_addr.s_addr;
753 			}
754 		}
755 
756 		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)	{
757 			if (ifa->ifa_addr->sa_family != AF_INET6)
758 				continue;
759 			if (match.s_addr == 0)
760 				break;
761 			candidate.s_addr = ((struct sockaddr_in *)&ifa->ifa_addr)->sin_addr.s_addr;
762 			candidate.s_addr &= mask.s_addr;
763 			if (candidate.s_addr == match.s_addr)
764 				break;
765 		}
766 		if (ifa == NULL)
767 			return (EADDRNOTAVAIL);
768 		ia = (struct in_ifaddr *)ifa;
769 
770 		if (cmd == SIOCGLIFADDR) {
771 			/* fill in the if_laddrreq structure */
772 			bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin_len);
773 
774 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
775 				bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
776 					ia->ia_dstaddr.sin_len);
777 			} else
778 				bzero(&iflr->dstaddr, sizeof(iflr->dstaddr));
779 
780 			iflr->prefixlen =
781 				in_mask2len(&ia->ia_sockmask.sin_addr);
782 
783 			iflr->flags = 0;	/*XXX*/
784 
785 			return (0);
786 		} else {
787 			struct in_aliasreq ifra;
788 
789 			/* fill in_aliasreq and do ioctl(SIOCDIFADDR_IN6) */
790 			bzero(&ifra, sizeof(ifra));
791 			bcopy(iflr->iflr_name, ifra.ifra_name,
792 				sizeof(ifra.ifra_name));
793 
794 			bcopy(&ia->ia_addr, &ifra.ifra_addr,
795 				ia->ia_addr.sin_len);
796 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
797 				bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
798 					ia->ia_dstaddr.sin_len);
799 			}
800 			bcopy(&ia->ia_sockmask, &ifra.ifra_dstaddr,
801 				ia->ia_sockmask.sin_len);
802 
803 			return (in_control(so, SIOCDIFADDR, (caddr_t)&ifra,
804 			    ifp, td));
805 		}
806 	    }
807 	}
808 
809 	return (EOPNOTSUPP);	/*just for safety*/
810 }
811 
812 /*
813  * Delete any existing route for an interface.
814  */
815 void
816 in_ifscrub(struct ifnet *ifp, struct in_ifaddr *ia, u_int flags)
817 {
818 
819 	in_scrubprefix(ia, flags);
820 }
821 
822 /*
823  * Initialize an interface's internet address
824  * and routing table entry.
825  */
826 static int
827 in_ifinit(struct ifnet *ifp, struct in_ifaddr *ia, struct sockaddr_in *sin,
828     int scrub)
829 {
830 	register u_long i = ntohl(sin->sin_addr.s_addr);
831 	struct sockaddr_in oldaddr;
832 	int flags = RTF_UP, error = 0;
833 
834 	oldaddr = ia->ia_addr;
835 	if (oldaddr.sin_family == AF_INET)
836 		LIST_REMOVE(ia, ia_hash);
837 	ia->ia_addr = *sin;
838 	if (ia->ia_addr.sin_family == AF_INET) {
839 		IN_IFADDR_WLOCK();
840 		LIST_INSERT_HEAD(INADDR_HASH(ia->ia_addr.sin_addr.s_addr),
841 		    ia, ia_hash);
842 		IN_IFADDR_WUNLOCK();
843 	}
844 	/*
845 	 * Give the interface a chance to initialize
846 	 * if this is its first address,
847 	 * and to validate the address if necessary.
848 	 */
849 	if (ifp->if_ioctl != NULL) {
850 		error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia);
851 		if (error) {
852 			/* LIST_REMOVE(ia, ia_hash) is done in in_control */
853 			ia->ia_addr = oldaddr;
854 			IN_IFADDR_WLOCK();
855 			if (ia->ia_addr.sin_family == AF_INET)
856 				LIST_INSERT_HEAD(INADDR_HASH(
857 				    ia->ia_addr.sin_addr.s_addr), ia, ia_hash);
858 			else
859 				/*
860 				 * If oldaddr family is not AF_INET (e.g.
861 				 * interface has been just created) in_control
862 				 * does not call LIST_REMOVE, and we end up
863 				 * with bogus ia entries in hash
864 				 */
865 				LIST_REMOVE(ia, ia_hash);
866 			IN_IFADDR_WUNLOCK();
867 			return (error);
868 		}
869 	}
870 	if (scrub) {
871 		ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr;
872 		in_ifscrub(ifp, ia, LLE_STATIC);
873 		ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
874 	}
875 	/*
876 	 * Be compatible with network classes, if netmask isn't supplied,
877 	 * guess it based on classes.
878 	 */
879 	if (ia->ia_subnetmask == 0) {
880 		if (IN_CLASSA(i))
881 			ia->ia_subnetmask = IN_CLASSA_NET;
882 		else if (IN_CLASSB(i))
883 			ia->ia_subnetmask = IN_CLASSB_NET;
884 		else
885 			ia->ia_subnetmask = IN_CLASSC_NET;
886 		ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
887 	}
888 	ia->ia_subnet = i & ia->ia_subnetmask;
889 	in_socktrim(&ia->ia_sockmask);
890 	/*
891 	 * XXX: carp(4) does not have interface route
892 	 */
893 	if (ifp->if_type == IFT_CARP)
894 		return (0);
895 	/*
896 	 * Add route for the network.
897 	 */
898 	ia->ia_ifa.ifa_metric = ifp->if_metric;
899 	if (ifp->if_flags & IFF_BROADCAST) {
900 		if (ia->ia_subnetmask == IN_RFC3021_MASK)
901 			ia->ia_broadaddr.sin_addr.s_addr = INADDR_BROADCAST;
902 		else
903 			ia->ia_broadaddr.sin_addr.s_addr =
904 			    htonl(ia->ia_subnet | ~ia->ia_subnetmask);
905 	} else if (ifp->if_flags & IFF_LOOPBACK) {
906 		ia->ia_dstaddr = ia->ia_addr;
907 		flags |= RTF_HOST;
908 	} else if (ifp->if_flags & IFF_POINTOPOINT) {
909 		if (ia->ia_dstaddr.sin_family != AF_INET)
910 			return (0);
911 		flags |= RTF_HOST;
912 	}
913 	if ((error = in_addprefix(ia, flags)) != 0)
914 		return (error);
915 
916 	if (ia->ia_addr.sin_addr.s_addr == INADDR_ANY)
917 		return (0);
918 
919 	if (ifp->if_flags & IFF_POINTOPOINT) {
920 		if (ia->ia_dstaddr.sin_addr.s_addr == ia->ia_addr.sin_addr.s_addr)
921 			return (0);
922 	}
923 
924 
925 	/*
926 	 * add a loopback route to self
927 	 */
928 	if (V_useloopback && !(ifp->if_flags & IFF_LOOPBACK)) {
929 		struct route ia_ro;
930 
931 		bzero(&ia_ro, sizeof(ia_ro));
932 		*((struct sockaddr_in *)(&ia_ro.ro_dst)) = ia->ia_addr;
933 		rtalloc_ign_fib(&ia_ro, 0, 0);
934 		if ((ia_ro.ro_rt != NULL) && (ia_ro.ro_rt->rt_ifp != NULL) &&
935 		    (ia_ro.ro_rt->rt_ifp == V_loif)) {
936 			RT_LOCK(ia_ro.ro_rt);
937 			RT_ADDREF(ia_ro.ro_rt);
938 			RTFREE_LOCKED(ia_ro.ro_rt);
939 		} else
940 			error = ifa_add_loopback_route((struct ifaddr *)ia,
941 				       (struct sockaddr *)&ia->ia_addr);
942 		if (error == 0)
943 			ia->ia_flags |= IFA_RTSELF;
944 		if (ia_ro.ro_rt != NULL)
945 			RTFREE(ia_ro.ro_rt);
946 	}
947 
948 	return (error);
949 }
950 
951 #define rtinitflags(x) \
952 	((((x)->ia_ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) != 0) \
953 	    ? RTF_HOST : 0)
954 
955 /*
956  * Generate a routing message when inserting or deleting
957  * an interface address alias.
958  */
959 static void in_addralias_rtmsg(int cmd, struct in_addr *prefix,
960     struct in_ifaddr *target)
961 {
962 	struct route pfx_ro;
963 	struct sockaddr_in *pfx_addr;
964 	struct rtentry msg_rt;
965 
966 	/* QL: XXX
967 	 * This is a bit questionable because there is no
968 	 * additional route entry added/deleted for an address
969 	 * alias. Therefore this route report is inaccurate.
970 	 */
971 	bzero(&pfx_ro, sizeof(pfx_ro));
972 	pfx_addr = (struct sockaddr_in *)(&pfx_ro.ro_dst);
973 	pfx_addr->sin_len = sizeof(*pfx_addr);
974 	pfx_addr->sin_family = AF_INET;
975 	pfx_addr->sin_addr = *prefix;
976 	rtalloc_ign_fib(&pfx_ro, 0, 0);
977 	if (pfx_ro.ro_rt != NULL) {
978 		msg_rt = *pfx_ro.ro_rt;
979 
980 		/* QL: XXX
981 		 * Point the gateway to the new interface
982 		 * address as if a new prefix route entry has
983 		 * been added through the new address alias.
984 		 * All other parts of the rtentry is accurate,
985 		 * e.g., rt_key, rt_mask, rt_ifp etc.
986 		 */
987 		msg_rt.rt_gateway =
988 			(struct sockaddr *)&target->ia_addr;
989 		rt_newaddrmsg(cmd,
990 			      (struct ifaddr *)target,
991 			      0, &msg_rt);
992 		RTFREE(pfx_ro.ro_rt);
993 	}
994 	return;
995 }
996 
997 /*
998  * Check if we have a route for the given prefix already or add one accordingly.
999  */
1000 static int
1001 in_addprefix(struct in_ifaddr *target, int flags)
1002 {
1003 	struct in_ifaddr *ia;
1004 	struct in_addr prefix, mask, p, m;
1005 	int error;
1006 
1007 	if ((flags & RTF_HOST) != 0) {
1008 		prefix = target->ia_dstaddr.sin_addr;
1009 		mask.s_addr = 0;
1010 	} else {
1011 		prefix = target->ia_addr.sin_addr;
1012 		mask = target->ia_sockmask.sin_addr;
1013 		prefix.s_addr &= mask.s_addr;
1014 	}
1015 
1016 	IN_IFADDR_RLOCK();
1017 	TAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
1018 		if (rtinitflags(ia)) {
1019 			p = ia->ia_dstaddr.sin_addr;
1020 
1021 			if (prefix.s_addr != p.s_addr)
1022 				continue;
1023 		} else {
1024 			p = ia->ia_addr.sin_addr;
1025 			m = ia->ia_sockmask.sin_addr;
1026 			p.s_addr &= m.s_addr;
1027 
1028 			if (prefix.s_addr != p.s_addr ||
1029 			    mask.s_addr != m.s_addr)
1030 				continue;
1031 		}
1032 
1033 		/*
1034 		 * If we got a matching prefix route inserted by other
1035 		 * interface address, we are done here.
1036 		 */
1037 		if (ia->ia_flags & IFA_ROUTE) {
1038 #ifdef RADIX_MPATH
1039 			if (ia->ia_addr.sin_addr.s_addr ==
1040 			    target->ia_addr.sin_addr.s_addr) {
1041 				IN_IFADDR_RUNLOCK();
1042 				return (EEXIST);
1043 			} else
1044 				break;
1045 #endif
1046 			if (V_sameprefixcarponly &&
1047 			    target->ia_ifp->if_type != IFT_CARP &&
1048 			    ia->ia_ifp->if_type != IFT_CARP) {
1049 				IN_IFADDR_RUNLOCK();
1050 				return (EEXIST);
1051 			} else {
1052 				in_addralias_rtmsg(RTM_ADD, &prefix, target);
1053 				IN_IFADDR_RUNLOCK();
1054 				return (0);
1055 			}
1056 		}
1057 	}
1058 	IN_IFADDR_RUNLOCK();
1059 
1060 	/*
1061 	 * No-one seem to have this prefix route, so we try to insert it.
1062 	 */
1063 	error = rtinit(&target->ia_ifa, (int)RTM_ADD, flags);
1064 	if (!error)
1065 		target->ia_flags |= IFA_ROUTE;
1066 	return (error);
1067 }
1068 
1069 extern void arp_ifscrub(struct ifnet *ifp, uint32_t addr);
1070 
1071 /*
1072  * If there is no other address in the system that can serve a route to the
1073  * same prefix, remove the route.  Hand over the route to the new address
1074  * otherwise.
1075  */
1076 static int
1077 in_scrubprefix(struct in_ifaddr *target, u_int flags)
1078 {
1079 	struct in_ifaddr *ia;
1080 	struct in_addr prefix, mask, p;
1081 	int error = 0;
1082 	struct sockaddr_in prefix0, mask0;
1083 
1084 	/*
1085 	 * Remove the loopback route to the interface address.
1086 	 * The "useloopback" setting is not consulted because if the
1087 	 * user configures an interface address, turns off this
1088 	 * setting, and then tries to delete that interface address,
1089 	 * checking the current setting of "useloopback" would leave
1090 	 * that interface address loopback route untouched, which
1091 	 * would be wrong. Therefore the interface address loopback route
1092 	 * deletion is unconditional.
1093 	 */
1094 	if ((target->ia_addr.sin_addr.s_addr != INADDR_ANY) &&
1095 	    !(target->ia_ifp->if_flags & IFF_LOOPBACK) &&
1096 	    (target->ia_flags & IFA_RTSELF)) {
1097 		struct route ia_ro;
1098 		int freeit = 0;
1099 
1100 		bzero(&ia_ro, sizeof(ia_ro));
1101 		*((struct sockaddr_in *)(&ia_ro.ro_dst)) = target->ia_addr;
1102 		rtalloc_ign_fib(&ia_ro, 0, 0);
1103 		if ((ia_ro.ro_rt != NULL) && (ia_ro.ro_rt->rt_ifp != NULL) &&
1104 		    (ia_ro.ro_rt->rt_ifp == V_loif)) {
1105 			RT_LOCK(ia_ro.ro_rt);
1106 			if (ia_ro.ro_rt->rt_refcnt <= 1)
1107 				freeit = 1;
1108 			else if (flags & LLE_STATIC) {
1109 				RT_REMREF(ia_ro.ro_rt);
1110 				target->ia_flags &= ~IFA_RTSELF;
1111 			}
1112 			RTFREE_LOCKED(ia_ro.ro_rt);
1113 		}
1114 		if (freeit && (flags & LLE_STATIC)) {
1115 			error = ifa_del_loopback_route((struct ifaddr *)target,
1116 				       (struct sockaddr *)&target->ia_addr);
1117 			if (error == 0)
1118 				target->ia_flags &= ~IFA_RTSELF;
1119 		}
1120 		if ((flags & LLE_STATIC) &&
1121 			!(target->ia_ifp->if_flags & IFF_NOARP))
1122 			/* remove arp cache */
1123 			arp_ifscrub(target->ia_ifp, IA_SIN(target)->sin_addr.s_addr);
1124 	}
1125 
1126 	if (rtinitflags(target))
1127 		prefix = target->ia_dstaddr.sin_addr;
1128 	else {
1129 		prefix = target->ia_addr.sin_addr;
1130 		mask = target->ia_sockmask.sin_addr;
1131 		prefix.s_addr &= mask.s_addr;
1132 	}
1133 
1134 	if ((target->ia_flags & IFA_ROUTE) == 0) {
1135 		in_addralias_rtmsg(RTM_DELETE, &prefix, target);
1136 		return (0);
1137 	}
1138 
1139 	IN_IFADDR_RLOCK();
1140 	TAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
1141 		if (rtinitflags(ia))
1142 			p = ia->ia_dstaddr.sin_addr;
1143 		else {
1144 			p = ia->ia_addr.sin_addr;
1145 			p.s_addr &= ia->ia_sockmask.sin_addr.s_addr;
1146 		}
1147 
1148 		if ((prefix.s_addr != p.s_addr) ||
1149 		    !(ia->ia_ifp->if_flags & IFF_UP))
1150 			continue;
1151 
1152 		/*
1153 		 * If we got a matching prefix address, move IFA_ROUTE and
1154 		 * the route itself to it.  Make sure that routing daemons
1155 		 * get a heads-up.
1156 		 *
1157 		 * XXX: a special case for carp(4) interface - this should
1158 		 *      be more generally specified as an interface that
1159 		 *      doesn't support such action.
1160 		 */
1161 		if ((ia->ia_flags & IFA_ROUTE) == 0
1162 		    && (ia->ia_ifp->if_type != IFT_CARP)) {
1163 			ifa_ref(&ia->ia_ifa);
1164 			IN_IFADDR_RUNLOCK();
1165 			error = rtinit(&(target->ia_ifa), (int)RTM_DELETE,
1166 			    rtinitflags(target));
1167 			if (error == 0)
1168 				target->ia_flags &= ~IFA_ROUTE;
1169 			else
1170 				log(LOG_INFO, "in_scrubprefix: err=%d, old prefix delete failed\n",
1171 					error);
1172 			error = rtinit(&ia->ia_ifa, (int)RTM_ADD,
1173 			    rtinitflags(ia) | RTF_UP);
1174 			if (error == 0)
1175 				ia->ia_flags |= IFA_ROUTE;
1176 			else
1177 				log(LOG_INFO, "in_scrubprefix: err=%d, new prefix add failed\n",
1178 					error);
1179 			ifa_free(&ia->ia_ifa);
1180 			return (error);
1181 		}
1182 	}
1183 	IN_IFADDR_RUNLOCK();
1184 
1185 	/*
1186 	 * remove all L2 entries on the given prefix
1187 	 */
1188 	bzero(&prefix0, sizeof(prefix0));
1189 	prefix0.sin_len = sizeof(prefix0);
1190 	prefix0.sin_family = AF_INET;
1191 	prefix0.sin_addr.s_addr = target->ia_subnet;
1192 	bzero(&mask0, sizeof(mask0));
1193 	mask0.sin_len = sizeof(mask0);
1194 	mask0.sin_family = AF_INET;
1195 	mask0.sin_addr.s_addr = target->ia_subnetmask;
1196 	lltable_prefix_free(AF_INET, (struct sockaddr *)&prefix0,
1197 			    (struct sockaddr *)&mask0, flags);
1198 
1199 	/*
1200 	 * As no-one seem to have this prefix, we can remove the route.
1201 	 */
1202 	error = rtinit(&(target->ia_ifa), (int)RTM_DELETE, rtinitflags(target));
1203 	if (error == 0)
1204 		target->ia_flags &= ~IFA_ROUTE;
1205 	else
1206 		log(LOG_INFO, "in_scrubprefix: err=%d, prefix delete failed\n", error);
1207 	return (error);
1208 }
1209 
1210 #undef rtinitflags
1211 
1212 /*
1213  * Return 1 if the address might be a local broadcast address.
1214  */
1215 int
1216 in_broadcast(struct in_addr in, struct ifnet *ifp)
1217 {
1218 	register struct ifaddr *ifa;
1219 	u_long t;
1220 
1221 	if (in.s_addr == INADDR_BROADCAST ||
1222 	    in.s_addr == INADDR_ANY)
1223 		return (1);
1224 	if ((ifp->if_flags & IFF_BROADCAST) == 0)
1225 		return (0);
1226 	t = ntohl(in.s_addr);
1227 	/*
1228 	 * Look through the list of addresses for a match
1229 	 * with a broadcast address.
1230 	 */
1231 #define ia ((struct in_ifaddr *)ifa)
1232 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
1233 		if (ifa->ifa_addr->sa_family == AF_INET &&
1234 		    (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
1235 		     /*
1236 		      * Check for old-style (host 0) broadcast, but
1237 		      * taking into account that RFC 3021 obsoletes it.
1238 		      */
1239 		     (ia->ia_subnetmask != IN_RFC3021_MASK &&
1240 		     t == ia->ia_subnet)) &&
1241 		     /*
1242 		      * Check for an all one subnetmask. These
1243 		      * only exist when an interface gets a secondary
1244 		      * address.
1245 		      */
1246 		     ia->ia_subnetmask != (u_long)0xffffffff)
1247 			    return (1);
1248 	return (0);
1249 #undef ia
1250 }
1251 
1252 /*
1253  * On interface removal, clean up IPv4 data structures hung off of the ifnet.
1254  */
1255 void
1256 in_ifdetach(struct ifnet *ifp)
1257 {
1258 
1259 	in_pcbpurgeif0(&V_ripcbinfo, ifp);
1260 	in_pcbpurgeif0(&V_udbinfo, ifp);
1261 	in_purgemaddrs(ifp);
1262 }
1263 
1264 /*
1265  * Delete all IPv4 multicast address records, and associated link-layer
1266  * multicast address records, associated with ifp.
1267  * XXX It looks like domifdetach runs AFTER the link layer cleanup.
1268  * XXX This should not race with ifma_protospec being set during
1269  * a new allocation, if it does, we have bigger problems.
1270  */
1271 static void
1272 in_purgemaddrs(struct ifnet *ifp)
1273 {
1274 	LIST_HEAD(,in_multi) purgeinms;
1275 	struct in_multi		*inm, *tinm;
1276 	struct ifmultiaddr	*ifma;
1277 
1278 	LIST_INIT(&purgeinms);
1279 	IN_MULTI_LOCK();
1280 
1281 	/*
1282 	 * Extract list of in_multi associated with the detaching ifp
1283 	 * which the PF_INET layer is about to release.
1284 	 * We need to do this as IF_ADDR_LOCK() may be re-acquired
1285 	 * by code further down.
1286 	 */
1287 	IF_ADDR_LOCK(ifp);
1288 	TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
1289 		if (ifma->ifma_addr->sa_family != AF_INET ||
1290 		    ifma->ifma_protospec == NULL)
1291 			continue;
1292 #if 0
1293 		KASSERT(ifma->ifma_protospec != NULL,
1294 		    ("%s: ifma_protospec is NULL", __func__));
1295 #endif
1296 		inm = (struct in_multi *)ifma->ifma_protospec;
1297 		LIST_INSERT_HEAD(&purgeinms, inm, inm_link);
1298 	}
1299 	IF_ADDR_UNLOCK(ifp);
1300 
1301 	LIST_FOREACH_SAFE(inm, &purgeinms, inm_link, tinm) {
1302 		LIST_REMOVE(inm, inm_link);
1303 		inm_release_locked(inm);
1304 	}
1305 	igmp_ifdetach(ifp);
1306 
1307 	IN_MULTI_UNLOCK();
1308 }
1309 
1310 #include <net/if_dl.h>
1311 #include <netinet/if_ether.h>
1312 
1313 struct in_llentry {
1314 	struct llentry		base;
1315 	struct sockaddr_in	l3_addr4;
1316 };
1317 
1318 static struct llentry *
1319 in_lltable_new(const struct sockaddr *l3addr, u_int flags)
1320 {
1321 	struct in_llentry *lle;
1322 
1323 	lle = malloc(sizeof(struct in_llentry), M_LLTABLE, M_DONTWAIT | M_ZERO);
1324 	if (lle == NULL)		/* NB: caller generates msg */
1325 		return NULL;
1326 
1327 	callout_init(&lle->base.la_timer, CALLOUT_MPSAFE);
1328 	/*
1329 	 * For IPv4 this will trigger "arpresolve" to generate
1330 	 * an ARP request.
1331 	 */
1332 	lle->base.la_expire = time_uptime; /* mark expired */
1333 	lle->l3_addr4 = *(const struct sockaddr_in *)l3addr;
1334 	lle->base.lle_refcnt = 1;
1335 	LLE_LOCK_INIT(&lle->base);
1336 	return &lle->base;
1337 }
1338 
1339 /*
1340  * Deletes an address from the address table.
1341  * This function is called by the timer functions
1342  * such as arptimer() and nd6_llinfo_timer(), and
1343  * the caller does the locking.
1344  */
1345 static void
1346 in_lltable_free(struct lltable *llt, struct llentry *lle)
1347 {
1348 	LLE_WUNLOCK(lle);
1349 	LLE_LOCK_DESTROY(lle);
1350 	free(lle, M_LLTABLE);
1351 }
1352 
1353 
1354 #define IN_ARE_MASKED_ADDR_EQUAL(d, a, m)	(			\
1355 	    (((ntohl((d)->sin_addr.s_addr) ^ (a)->sin_addr.s_addr) & (m)->sin_addr.s_addr)) == 0 )
1356 
1357 static void
1358 in_lltable_prefix_free(struct lltable *llt,
1359 		       const struct sockaddr *prefix,
1360 		       const struct sockaddr *mask,
1361 		       u_int flags)
1362 {
1363 	const struct sockaddr_in *pfx = (const struct sockaddr_in *)prefix;
1364 	const struct sockaddr_in *msk = (const struct sockaddr_in *)mask;
1365 	struct llentry *lle, *next;
1366 	register int i;
1367 	size_t pkts_dropped;
1368 
1369 	for (i=0; i < LLTBL_HASHTBL_SIZE; i++) {
1370 		LIST_FOREACH_SAFE(lle, &llt->lle_head[i], lle_next, next) {
1371 
1372 		        /*
1373 			 * (flags & LLE_STATIC) means deleting all entries
1374 			 * including static ARP entries
1375 			 */
1376 			if (IN_ARE_MASKED_ADDR_EQUAL((struct sockaddr_in *)L3_ADDR(lle),
1377 						     pfx, msk) &&
1378 			    ((flags & LLE_STATIC) || !(lle->la_flags & LLE_STATIC))) {
1379 				int canceled;
1380 
1381 				canceled = callout_drain(&lle->la_timer);
1382 				LLE_WLOCK(lle);
1383 				if (canceled)
1384 					LLE_REMREF(lle);
1385 				pkts_dropped = llentry_free(lle);
1386 				ARPSTAT_ADD(dropped, pkts_dropped);
1387 			}
1388 		}
1389 	}
1390 }
1391 
1392 
1393 static int
1394 in_lltable_rtcheck(struct ifnet *ifp, u_int flags, const struct sockaddr *l3addr)
1395 {
1396 	struct rtentry *rt;
1397 
1398 	KASSERT(l3addr->sa_family == AF_INET,
1399 	    ("sin_family %d", l3addr->sa_family));
1400 
1401 	/* XXX rtalloc1 should take a const param */
1402 	rt = rtalloc1(__DECONST(struct sockaddr *, l3addr), 0, 0);
1403 
1404 	if (rt == NULL)
1405 		return (EINVAL);
1406 
1407 	/*
1408 	 * If the gateway for an existing host route matches the target L3
1409 	 * address, which is a special route inserted by some implementation
1410 	 * such as MANET, and the interface is of the correct type, then
1411 	 * allow for ARP to proceed.
1412 	 */
1413 	if (rt->rt_flags & RTF_GATEWAY) {
1414 		if (!(rt->rt_flags & RTF_HOST) || !rt->rt_ifp ||
1415 			rt->rt_ifp->if_type != IFT_ETHER ||
1416 			  (rt->rt_ifp->if_flags &
1417 			   (IFF_NOARP | IFF_STATICARP)) != 0 ||
1418 			  memcmp(rt->rt_gateway->sa_data, l3addr->sa_data,
1419 				 sizeof(in_addr_t)) != 0) {
1420 			RTFREE_LOCKED(rt);
1421 			return (EINVAL);
1422 		}
1423 	}
1424 
1425 	/*
1426 	 * Make sure that at least the destination address is covered
1427 	 * by the route. This is for handling the case where 2 or more
1428 	 * interfaces have the same prefix. An incoming packet arrives
1429 	 * on one interface and the corresponding outgoing packet leaves
1430 	 * another interface.
1431 	 */
1432 	if (!(rt->rt_flags & RTF_HOST) && rt->rt_ifp != ifp) {
1433 		const char *sa, *mask, *addr, *lim;
1434 		int len;
1435 
1436 		mask = (const char *)rt_mask(rt);
1437 		/*
1438 		 * Just being extra cautious to avoid some custom
1439 		 * code getting into trouble.
1440 		 */
1441 		if (mask == NULL) {
1442 			RTFREE_LOCKED(rt);
1443 			return (EINVAL);
1444 		}
1445 
1446 		sa = (const char *)rt_key(rt);
1447 		addr = (const char *)l3addr;
1448 		len = ((const struct sockaddr_in *)l3addr)->sin_len;
1449 		lim = addr + len;
1450 
1451 		for ( ; addr < lim; sa++, mask++, addr++) {
1452 			if ((*sa ^ *addr) & *mask) {
1453 #ifdef DIAGNOSTIC
1454 				log(LOG_INFO, "IPv4 address: \"%s\" is not on the network\n",
1455 				    inet_ntoa(((const struct sockaddr_in *)l3addr)->sin_addr));
1456 #endif
1457 				RTFREE_LOCKED(rt);
1458 				return (EINVAL);
1459 			}
1460 		}
1461 	}
1462 
1463 	RTFREE_LOCKED(rt);
1464 	return (0);
1465 }
1466 
1467 /*
1468  * Return NULL if not found or marked for deletion.
1469  * If found return lle read locked.
1470  */
1471 static struct llentry *
1472 in_lltable_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
1473 {
1474 	const struct sockaddr_in *sin = (const struct sockaddr_in *)l3addr;
1475 	struct ifnet *ifp = llt->llt_ifp;
1476 	struct llentry *lle;
1477 	struct llentries *lleh;
1478 	u_int hashkey;
1479 
1480 	IF_AFDATA_LOCK_ASSERT(ifp);
1481 	KASSERT(l3addr->sa_family == AF_INET,
1482 	    ("sin_family %d", l3addr->sa_family));
1483 
1484 	hashkey = sin->sin_addr.s_addr;
1485 	lleh = &llt->lle_head[LLATBL_HASH(hashkey, LLTBL_HASHMASK)];
1486 	LIST_FOREACH(lle, lleh, lle_next) {
1487 		struct sockaddr_in *sa2 = (struct sockaddr_in *)L3_ADDR(lle);
1488 		if (lle->la_flags & LLE_DELETED)
1489 			continue;
1490 		if (sa2->sin_addr.s_addr == sin->sin_addr.s_addr)
1491 			break;
1492 	}
1493 	if (lle == NULL) {
1494 #ifdef DIAGNOSTIC
1495 		if (flags & LLE_DELETE)
1496 			log(LOG_INFO, "interface address is missing from cache = %p  in delete\n", lle);
1497 #endif
1498 		if (!(flags & LLE_CREATE))
1499 			return (NULL);
1500 		/*
1501 		 * A route that covers the given address must have
1502 		 * been installed 1st because we are doing a resolution,
1503 		 * verify this.
1504 		 */
1505 		if (!(flags & LLE_IFADDR) &&
1506 		    in_lltable_rtcheck(ifp, flags, l3addr) != 0)
1507 			goto done;
1508 
1509 		lle = in_lltable_new(l3addr, flags);
1510 		if (lle == NULL) {
1511 			log(LOG_INFO, "lla_lookup: new lle malloc failed\n");
1512 			goto done;
1513 		}
1514 		lle->la_flags = flags & ~LLE_CREATE;
1515 		if ((flags & (LLE_CREATE | LLE_IFADDR)) == (LLE_CREATE | LLE_IFADDR)) {
1516 			bcopy(IF_LLADDR(ifp), &lle->ll_addr, ifp->if_addrlen);
1517 			lle->la_flags |= (LLE_VALID | LLE_STATIC);
1518 		}
1519 
1520 		lle->lle_tbl  = llt;
1521 		lle->lle_head = lleh;
1522 		LIST_INSERT_HEAD(lleh, lle, lle_next);
1523 	} else if (flags & LLE_DELETE) {
1524 		if (!(lle->la_flags & LLE_IFADDR) || (flags & LLE_IFADDR)) {
1525 			LLE_WLOCK(lle);
1526 			lle->la_flags = LLE_DELETED;
1527 			EVENTHANDLER_INVOKE(arp_update_event, lle);
1528 			LLE_WUNLOCK(lle);
1529 #ifdef DIAGNOSTIC
1530 			log(LOG_INFO, "ifaddr cache = %p  is deleted\n", lle);
1531 #endif
1532 		}
1533 		lle = (void *)-1;
1534 
1535 	}
1536 	if (LLE_IS_VALID(lle)) {
1537 		if (flags & LLE_EXCLUSIVE)
1538 			LLE_WLOCK(lle);
1539 		else
1540 			LLE_RLOCK(lle);
1541 	}
1542 done:
1543 	return (lle);
1544 }
1545 
1546 static int
1547 in_lltable_dump(struct lltable *llt, struct sysctl_req *wr)
1548 {
1549 #define	SIN(lle)	((struct sockaddr_in *) L3_ADDR(lle))
1550 	struct ifnet *ifp = llt->llt_ifp;
1551 	struct llentry *lle;
1552 	/* XXX stack use */
1553 	struct {
1554 		struct rt_msghdr	rtm;
1555 		struct sockaddr_inarp	sin;
1556 		struct sockaddr_dl	sdl;
1557 	} arpc;
1558 	int error, i;
1559 
1560 	LLTABLE_LOCK_ASSERT();
1561 
1562 	error = 0;
1563 	for (i = 0; i < LLTBL_HASHTBL_SIZE; i++) {
1564 		LIST_FOREACH(lle, &llt->lle_head[i], lle_next) {
1565 			struct sockaddr_dl *sdl;
1566 
1567 			/* skip deleted entries */
1568 			if ((lle->la_flags & LLE_DELETED) == LLE_DELETED)
1569 				continue;
1570 			/* Skip if jailed and not a valid IP of the prison. */
1571 			if (prison_if(wr->td->td_ucred, L3_ADDR(lle)) != 0)
1572 				continue;
1573 			/*
1574 			 * produce a msg made of:
1575 			 *  struct rt_msghdr;
1576 			 *  struct sockaddr_inarp; (IPv4)
1577 			 *  struct sockaddr_dl;
1578 			 */
1579 			bzero(&arpc, sizeof(arpc));
1580 			arpc.rtm.rtm_msglen = sizeof(arpc);
1581 			arpc.rtm.rtm_version = RTM_VERSION;
1582 			arpc.rtm.rtm_type = RTM_GET;
1583 			arpc.rtm.rtm_flags = RTF_UP;
1584 			arpc.rtm.rtm_addrs = RTA_DST | RTA_GATEWAY;
1585 			arpc.sin.sin_family = AF_INET;
1586 			arpc.sin.sin_len = sizeof(arpc.sin);
1587 			arpc.sin.sin_addr.s_addr = SIN(lle)->sin_addr.s_addr;
1588 
1589 			/* publish */
1590 			if (lle->la_flags & LLE_PUB) {
1591 				arpc.rtm.rtm_flags |= RTF_ANNOUNCE;
1592 				/* proxy only */
1593 				if (lle->la_flags & LLE_PROXY)
1594 					arpc.sin.sin_other = SIN_PROXY;
1595 			}
1596 
1597 			sdl = &arpc.sdl;
1598 			sdl->sdl_family = AF_LINK;
1599 			sdl->sdl_len = sizeof(*sdl);
1600 			sdl->sdl_index = ifp->if_index;
1601 			sdl->sdl_type = ifp->if_type;
1602 			if ((lle->la_flags & LLE_VALID) == LLE_VALID) {
1603 				sdl->sdl_alen = ifp->if_addrlen;
1604 				bcopy(&lle->ll_addr, LLADDR(sdl), ifp->if_addrlen);
1605 			} else {
1606 				sdl->sdl_alen = 0;
1607 				bzero(LLADDR(sdl), ifp->if_addrlen);
1608 			}
1609 
1610 			arpc.rtm.rtm_rmx.rmx_expire =
1611 			    lle->la_flags & LLE_STATIC ? 0 : lle->la_expire;
1612 			arpc.rtm.rtm_flags |= (RTF_HOST | RTF_LLDATA);
1613 			if (lle->la_flags & LLE_STATIC)
1614 				arpc.rtm.rtm_flags |= RTF_STATIC;
1615 			arpc.rtm.rtm_index = ifp->if_index;
1616 			error = SYSCTL_OUT(wr, &arpc, sizeof(arpc));
1617 			if (error)
1618 				break;
1619 		}
1620 	}
1621 	return error;
1622 #undef SIN
1623 }
1624 
1625 void *
1626 in_domifattach(struct ifnet *ifp)
1627 {
1628 	struct in_ifinfo *ii;
1629 	struct lltable *llt;
1630 
1631 	ii = malloc(sizeof(struct in_ifinfo), M_IFADDR, M_WAITOK|M_ZERO);
1632 
1633 	llt = lltable_init(ifp, AF_INET);
1634 	if (llt != NULL) {
1635 		llt->llt_free = in_lltable_free;
1636 		llt->llt_prefix_free = in_lltable_prefix_free;
1637 		llt->llt_lookup = in_lltable_lookup;
1638 		llt->llt_dump = in_lltable_dump;
1639 	}
1640 	ii->ii_llt = llt;
1641 
1642 	ii->ii_igmp = igmp_domifattach(ifp);
1643 
1644 	return ii;
1645 }
1646 
1647 void
1648 in_domifdetach(struct ifnet *ifp, void *aux)
1649 {
1650 	struct in_ifinfo *ii = (struct in_ifinfo *)aux;
1651 
1652 	igmp_domifdetach(ifp);
1653 	lltable_free(ii->ii_llt);
1654 	free(ii, M_IFADDR);
1655 }
1656