xref: /dflybsd-src/sys/netinet/in.c (revision 2a1ad637466621af45d5a17185b33f3dcaaa1b1c)
1 /*
2  * Copyright (c) 1982, 1986, 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)in.c	8.4 (Berkeley) 1/9/95
30  * $FreeBSD: src/sys/netinet/in.c,v 1.44.2.14 2002/11/08 00:45:50 suz Exp $
31  */
32 
33 #include "opt_bootp.h"
34 #include "opt_carp.h"
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/sockio.h>
39 #include <sys/malloc.h>
40 #include <sys/proc.h>
41 #include <sys/priv.h>
42 #include <sys/msgport.h>
43 #include <sys/socket.h>
44 
45 #include <sys/kernel.h>
46 #include <sys/sysctl.h>
47 #include <sys/thread2.h>
48 
49 #include <net/if.h>
50 #include <net/if_types.h>
51 #include <net/route.h>
52 #include <net/netmsg2.h>
53 #include <net/netisr2.h>
54 
55 #include <netinet/in.h>
56 #include <netinet/in_var.h>
57 #include <netinet/in_pcb.h>
58 #include <netinet/udp_var.h>
59 
60 #include <netinet/igmp_var.h>
61 
62 MALLOC_DEFINE(M_IPMADDR, "in_multi", "internet multicast address");
63 
64 static int in_mask2len (struct in_addr *);
65 static void in_len2mask (struct in_addr *, int);
66 static int in_lifaddr_ioctl (u_long, caddr_t, struct ifnet *, struct thread *);
67 
68 static void	in_socktrim (struct sockaddr_in *);
69 static int	in_ifinit(struct ifnet *, struct in_ifaddr *,
70 		    const struct sockaddr_in *, int);
71 
72 static int	in_control_internal(u_long, caddr_t, struct ifnet *,
73 		    struct thread *);
74 
75 static int	in_addprefix(struct in_ifaddr *, int);
76 static void	in_scrubprefix(struct in_ifaddr *);
77 
78 static int subnetsarelocal = 0;
79 SYSCTL_INT(_net_inet_ip, OID_AUTO, subnets_are_local, CTLFLAG_RW,
80     &subnetsarelocal, 0,
81     "Count all internet addresses of subnets of the local net as local");
82 
83 struct in_multihead in_multihead; /* XXX BSS initialization */
84 
85 extern struct inpcbinfo ripcbinfo;
86 
87 /*
88  * Return 1 if an internet address is for a ``local'' host
89  * (one to which we have a connection).  If subnetsarelocal
90  * is true, this includes other subnets of the local net.
91  * Otherwise, it includes only the directly-connected (sub)nets.
92  */
93 int
94 in_localaddr(struct in_addr in)
95 {
96 	u_long i = ntohl(in.s_addr);
97 	struct in_ifaddr_container *iac;
98 	struct in_ifaddr *ia;
99 
100 	if (subnetsarelocal) {
101 		TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) {
102 			ia = iac->ia;
103 
104 			if ((i & ia->ia_netmask) == ia->ia_net)
105 				return (1);
106 		}
107 	} else {
108 		TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) {
109 			ia = iac->ia;
110 
111 			if ((i & ia->ia_subnetmask) == ia->ia_subnet)
112 				return (1);
113 		}
114 	}
115 	return (0);
116 }
117 
118 /*
119  * Determine whether an IP address is in a reserved set of addresses
120  * that may not be forwarded, or whether datagrams to that destination
121  * may be forwarded.
122  */
123 int
124 in_canforward(struct in_addr in)
125 {
126 	u_long i = ntohl(in.s_addr);
127 	u_long net;
128 
129 	if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i))
130 		return (0);
131 	if (IN_CLASSA(i)) {
132 		net = i & IN_CLASSA_NET;
133 		if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
134 			return (0);
135 	}
136 	return (1);
137 }
138 
139 /*
140  * Trim a mask in a sockaddr
141  */
142 static void
143 in_socktrim(struct sockaddr_in *ap)
144 {
145     char *cplim = (char *) &ap->sin_addr;
146     char *cp = (char *) (&ap->sin_addr + 1);
147 
148     ap->sin_len = 0;
149     while (--cp >= cplim)
150 	if (*cp) {
151 	    (ap)->sin_len = cp - (char *) (ap) + 1;
152 	    break;
153 	}
154 }
155 
156 static int
157 in_mask2len(struct in_addr *mask)
158 {
159 	int x, y;
160 	u_char *p;
161 
162 	p = (u_char *)mask;
163 	for (x = 0; x < sizeof *mask; x++) {
164 		if (p[x] != 0xff)
165 			break;
166 	}
167 	y = 0;
168 	if (x < sizeof *mask) {
169 		for (y = 0; y < 8; y++) {
170 			if ((p[x] & (0x80 >> y)) == 0)
171 				break;
172 		}
173 	}
174 	return x * 8 + y;
175 }
176 
177 static void
178 in_len2mask(struct in_addr *mask, int len)
179 {
180 	int i;
181 	u_char *p;
182 
183 	p = (u_char *)mask;
184 	bzero(mask, sizeof *mask);
185 	for (i = 0; i < len / 8; i++)
186 		p[i] = 0xff;
187 	if (len % 8)
188 		p[i] = (0xff00 >> (len % 8)) & 0xff;
189 }
190 
191 static int in_interfaces;	/* number of external internet interfaces */
192 
193 void
194 in_control_dispatch(netmsg_t msg)
195 {
196 	int error;
197 
198 	error = in_control(msg->control.nm_cmd, msg->control.nm_data,
199 	    msg->control.nm_ifp, msg->control.nm_td);
200 	lwkt_replymsg(&msg->lmsg, error);
201 }
202 
203 static void
204 in_control_internal_dispatch(netmsg_t msg)
205 {
206 	int error;
207 
208 	error = in_control_internal(msg->control.nm_cmd,
209 				    msg->control.nm_data,
210 				    msg->control.nm_ifp,
211 				    msg->control.nm_td);
212 	lwkt_replymsg(&msg->lmsg, error);
213 }
214 
215 /*
216  * Generic internet control operations (ioctl's).
217  * Ifp is 0 if not an interface-specific ioctl.
218  *
219  * NOTE! td might be NULL.
220  */
221 int
222 in_control(u_long cmd, caddr_t data, struct ifnet *ifp, struct thread *td)
223 {
224 	struct netmsg_pru_control msg;
225 
226 	switch (cmd) {
227 	/* change address */
228 	case SIOCALIFADDR:
229 	case SIOCDLIFADDR:
230 	case SIOCSIFDSTADDR:
231 	case SIOCSIFBRDADDR:
232 	case SIOCSIFADDR:
233 	case SIOCSIFNETMASK:
234 	case SIOCAIFADDR:
235 	case SIOCDIFADDR:
236 		/*
237 		 * Dispatch these SIOCs to netisr0.
238 		 */
239 		netmsg_init(&msg.base, NULL, &curthread->td_msgport, 0,
240 		    in_control_internal_dispatch);
241 		msg.nm_cmd = cmd;
242 		msg.nm_data = data;
243 		msg.nm_ifp = ifp;
244 		msg.nm_td = td;
245 		lwkt_domsg(netisr_cpuport(0), &msg.base.lmsg, 0);
246 		return msg.base.lmsg.ms_error;
247 
248 	default:
249 		return in_control_internal(cmd, data, ifp, td);
250 	}
251 }
252 
253 static void
254 in_ialink_dispatch(netmsg_t msg)
255 {
256 	struct in_ifaddr *ia = msg->lmsg.u.ms_resultp;
257 	struct ifaddr_container *ifac;
258 	struct in_ifaddr_container *iac;
259 	int cpu = mycpuid;
260 
261 	crit_enter();
262 
263 	ifac = &ia->ia_ifa.ifa_containers[cpu];
264 	ASSERT_IFAC_VALID(ifac);
265 	KASSERT((ifac->ifa_listmask & IFA_LIST_IN_IFADDRHEAD) == 0,
266 		("ia is on in_ifaddrheads"));
267 
268 	ifac->ifa_listmask |= IFA_LIST_IN_IFADDRHEAD;
269 	iac = &ifac->ifa_proto_u.u_in_ifac;
270 	TAILQ_INSERT_TAIL(&in_ifaddrheads[cpu], iac, ia_link);
271 
272 	crit_exit();
273 
274 	ifa_forwardmsg(&msg->lmsg, cpu + 1);
275 }
276 
277 static void
278 in_iaunlink_dispatch(netmsg_t msg)
279 {
280 	struct in_ifaddr *ia = msg->lmsg.u.ms_resultp;
281 	struct ifaddr_container *ifac;
282 	struct in_ifaddr_container *iac;
283 	int cpu = mycpuid;
284 
285 	crit_enter();
286 
287 	ifac = &ia->ia_ifa.ifa_containers[cpu];
288 	ASSERT_IFAC_VALID(ifac);
289 	KASSERT(ifac->ifa_listmask & IFA_LIST_IN_IFADDRHEAD,
290 		("ia is not on in_ifaddrheads"));
291 
292 	iac = &ifac->ifa_proto_u.u_in_ifac;
293 	TAILQ_REMOVE(&in_ifaddrheads[cpu], iac, ia_link);
294 	ifac->ifa_listmask &= ~IFA_LIST_IN_IFADDRHEAD;
295 
296 	crit_exit();
297 
298 	ifa_forwardmsg(&msg->lmsg, cpu + 1);
299 }
300 
301 static void
302 in_iahashins_dispatch(netmsg_t msg)
303 {
304 	struct in_ifaddr *ia = msg->lmsg.u.ms_resultp;
305 	struct ifaddr_container *ifac;
306 	struct in_ifaddr_container *iac;
307 	int cpu = mycpuid;
308 
309 	crit_enter();
310 
311 	ifac = &ia->ia_ifa.ifa_containers[cpu];
312 	ASSERT_IFAC_VALID(ifac);
313 	KASSERT((ifac->ifa_listmask & IFA_LIST_IN_IFADDRHASH) == 0,
314 		("ia is on in_ifaddrhashtbls"));
315 
316 	ifac->ifa_listmask |= IFA_LIST_IN_IFADDRHASH;
317 	iac = &ifac->ifa_proto_u.u_in_ifac;
318 	LIST_INSERT_HEAD(INADDR_HASH(ia->ia_addr.sin_addr.s_addr),
319 			 iac, ia_hash);
320 
321 	crit_exit();
322 
323 	ifa_forwardmsg(&msg->lmsg, cpu + 1);
324 }
325 
326 static void
327 in_iahashrem_dispatch(netmsg_t msg)
328 {
329 	struct in_ifaddr *ia = msg->lmsg.u.ms_resultp;
330 	struct ifaddr_container *ifac;
331 	struct in_ifaddr_container *iac;
332 	int cpu = mycpuid;
333 
334 	crit_enter();
335 
336 	ifac = &ia->ia_ifa.ifa_containers[cpu];
337 	ASSERT_IFAC_VALID(ifac);
338 	KASSERT(ifac->ifa_listmask & IFA_LIST_IN_IFADDRHASH,
339 		("ia is not on in_ifaddrhashtbls"));
340 
341 	iac = &ifac->ifa_proto_u.u_in_ifac;
342 	LIST_REMOVE(iac, ia_hash);
343 	ifac->ifa_listmask &= ~IFA_LIST_IN_IFADDRHASH;
344 
345 	crit_exit();
346 
347 	ifa_forwardmsg(&msg->lmsg, cpu + 1);
348 }
349 
350 static void
351 in_ialink(struct in_ifaddr *ia)
352 {
353 	struct netmsg_base msg;
354 
355 	netmsg_init(&msg, NULL, &curthread->td_msgport,
356 		    0, in_ialink_dispatch);
357 	msg.lmsg.u.ms_resultp = ia;
358 
359 	ifa_domsg(&msg.lmsg, 0);
360 }
361 
362 void
363 in_iaunlink(struct in_ifaddr *ia)
364 {
365 	struct netmsg_base msg;
366 
367 	netmsg_init(&msg, NULL, &curthread->td_msgport,
368 		    0, in_iaunlink_dispatch);
369 	msg.lmsg.u.ms_resultp = ia;
370 
371 	ifa_domsg(&msg.lmsg, 0);
372 }
373 
374 void
375 in_iahash_insert(struct in_ifaddr *ia)
376 {
377 	struct netmsg_base msg;
378 
379 	netmsg_init(&msg, NULL, &curthread->td_msgport,
380 		    0, in_iahashins_dispatch);
381 	msg.lmsg.u.ms_resultp = ia;
382 
383 	ifa_domsg(&msg.lmsg, 0);
384 }
385 
386 void
387 in_iahash_remove(struct in_ifaddr *ia)
388 {
389 	struct netmsg_base msg;
390 
391 	netmsg_init(&msg, NULL, &curthread->td_msgport,
392 		    0, in_iahashrem_dispatch);
393 	msg.lmsg.u.ms_resultp = ia;
394 
395 	ifa_domsg(&msg.lmsg, 0);
396 }
397 
398 static __inline struct in_ifaddr *
399 in_ianext(struct in_ifaddr *oia)
400 {
401 	struct ifaddr_container *ifac;
402 	struct in_ifaddr_container *iac;
403 
404 	ifac = &oia->ia_ifa.ifa_containers[mycpuid];
405 	ASSERT_IFAC_VALID(ifac);
406 	KASSERT(ifac->ifa_listmask & IFA_LIST_IN_IFADDRHEAD,
407 		("ia is not on in_ifaddrheads"));
408 
409 	iac = &ifac->ifa_proto_u.u_in_ifac;
410 	iac = TAILQ_NEXT(iac, ia_link);
411 	if (iac != NULL)
412 		return iac->ia;
413 	else
414 		return NULL;
415 }
416 
417 static int
418 in_control_internal(u_long cmd, caddr_t data, struct ifnet *ifp,
419 		    struct thread *td)
420 {
421 	struct ifreq *ifr = (struct ifreq *)data;
422 	struct in_ifaddr *ia = NULL;
423 	struct in_addr dst;
424 	struct in_aliasreq *ifra = (struct in_aliasreq *)data;
425 	struct ifaddr_container *ifac;
426 	struct in_ifaddr_container *iac;
427 	struct sockaddr_in oldaddr;
428 	int hostIsNew, iaIsNew, maskIsNew, ifpWasUp;
429 	int error = 0;
430 
431 	switch (cmd) {
432 	case SIOCALIFADDR:
433 	case SIOCDLIFADDR:
434 		if (td && (error = priv_check(td, PRIV_ROOT)) != 0)
435 			return error;
436 		/* FALLTHROUGH */
437 	case SIOCGLIFADDR:
438 		if (!ifp)
439 			return EINVAL;
440 		return in_lifaddr_ioctl(cmd, data, ifp, td);
441 	}
442 
443 	iaIsNew = 0;
444 	ifpWasUp = 0;
445 
446 	/*
447 	 * Find address for this interface, if it exists.
448 	 *
449 	 * If an alias address was specified, find that one instead of
450 	 * the first one on the interface, if possible
451 	 */
452 	if (ifp) {
453 		struct in_ifaddr *iap;
454 
455 		dst = ((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr;
456 		LIST_FOREACH(iac, INADDR_HASH(dst.s_addr), ia_hash) {
457 			iap = iac->ia;
458 			if (iap->ia_ifp == ifp &&
459 			    iap->ia_addr.sin_addr.s_addr == dst.s_addr) {
460 				ia = iap;
461 				break;
462 			}
463 		}
464 		if (ia == NULL) {
465 			TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid],
466 				      ifa_link) {
467 				iap = ifatoia(ifac->ifa);
468 				if (iap->ia_addr.sin_family == AF_INET) {
469 					ia = iap;
470 					break;
471 				}
472 			}
473 		}
474 
475 		if (ifp->if_flags & IFF_UP)
476 			ifpWasUp = 1;
477 	}
478 
479 	switch (cmd) {
480 	case SIOCAIFADDR:
481 	case SIOCDIFADDR:
482 		if (ifp == NULL)
483 			return (EADDRNOTAVAIL);
484 		if (ifra->ifra_addr.sin_family == AF_INET) {
485 			while (ia != NULL) {
486 				if (ia->ia_ifp == ifp  &&
487 				    ia->ia_addr.sin_addr.s_addr ==
488 				    ifra->ifra_addr.sin_addr.s_addr)
489 					break;
490 				ia = in_ianext(ia);
491 			}
492 			if ((ifp->if_flags & IFF_POINTOPOINT) &&
493 			    cmd == SIOCAIFADDR &&
494 			    ifra->ifra_dstaddr.sin_addr.s_addr == INADDR_ANY) {
495 				return EDESTADDRREQ;
496 			}
497 		}
498 		if (cmd == SIOCDIFADDR && ia == NULL)
499 			return (EADDRNOTAVAIL);
500 		/* FALLTHROUGH */
501 	case SIOCSIFADDR:
502 	case SIOCSIFNETMASK:
503 	case SIOCSIFDSTADDR:
504 		if (td && (error = priv_check(td, PRIV_ROOT)) != 0)
505 			return error;
506 
507 		if (ifp == NULL)
508 			return (EADDRNOTAVAIL);
509 
510 		if (cmd == SIOCSIFDSTADDR &&
511 		    (ifp->if_flags & IFF_POINTOPOINT) == 0)
512 			return (EINVAL);
513 
514 		if (ia == NULL) {
515 			struct ifaddr *ifa;
516 			int i;
517 
518 			ia = ifa_create(sizeof(*ia), M_WAITOK);
519 			ifa = &ia->ia_ifa;
520 
521 			/*
522 			 * Setup per-CPU information
523 			 */
524 			for (i = 0; i < ncpus; ++i) {
525 				ifac = &ifa->ifa_containers[i];
526 				iac = &ifac->ifa_proto_u.u_in_ifac;
527 				iac->ia = ia;
528 				iac->ia_ifac = ifac;
529 			}
530 
531 			/*
532 			 * Protect from NETISR_IP traversing address list
533 			 * while we're modifying it.
534 			 */
535 			crit_enter();
536 
537 			in_ialink(ia);
538 			ifa_iflink(ifa, ifp, 1);
539 
540 			ifa->ifa_addr = (struct sockaddr *)&ia->ia_addr;
541 			ifa->ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr;
542 			ifa->ifa_netmask = (struct sockaddr *)&ia->ia_sockmask;
543 			ia->ia_sockmask.sin_len = 8;
544 			ia->ia_sockmask.sin_family = AF_INET;
545 			if (ifp->if_flags & IFF_BROADCAST) {
546 				ia->ia_broadaddr.sin_len = sizeof ia->ia_addr;
547 				ia->ia_broadaddr.sin_family = AF_INET;
548 			}
549 			ia->ia_ifp = ifp;
550 			if (!(ifp->if_flags & IFF_LOOPBACK))
551 				in_interfaces++;
552 			iaIsNew = 1;
553 
554 			crit_exit();
555 		}
556 		break;
557 
558 	case SIOCSIFBRDADDR:
559 		if (td && (error = priv_check(td, PRIV_ROOT)) != 0)
560 			return error;
561 		/* FALLTHROUGH */
562 
563 	case SIOCGIFADDR:
564 	case SIOCGIFNETMASK:
565 	case SIOCGIFDSTADDR:
566 	case SIOCGIFBRDADDR:
567 		if (ia == NULL)
568 			return (EADDRNOTAVAIL);
569 		break;
570 	}
571 
572 	switch (cmd) {
573 	case SIOCGIFADDR:
574 		*((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr;
575 		return (0);
576 
577 	case SIOCGIFBRDADDR:
578 		if ((ifp->if_flags & IFF_BROADCAST) == 0)
579 			return (EINVAL);
580 		*((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr;
581 		return (0);
582 
583 	case SIOCGIFDSTADDR:
584 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
585 			return (EINVAL);
586 		*((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr;
587 		return (0);
588 
589 	case SIOCGIFNETMASK:
590 		*((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask;
591 		return (0);
592 
593 	case SIOCSIFDSTADDR:
594 		KKASSERT(ifp->if_flags & IFF_POINTOPOINT);
595 
596 		oldaddr = ia->ia_dstaddr;
597 		ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr;
598 		if (ifp->if_ioctl != NULL) {
599 			ifnet_serialize_all(ifp);
600 			error = ifp->if_ioctl(ifp, SIOCSIFDSTADDR, (caddr_t)ia,
601 					      td->td_proc->p_ucred);
602 			ifnet_deserialize_all(ifp);
603 			if (error) {
604 				ia->ia_dstaddr = oldaddr;
605 				return (error);
606 			}
607 		}
608 		if (ia->ia_flags & IFA_ROUTE) {
609 			ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr;
610 			rtinit(&ia->ia_ifa, RTM_DELETE, RTF_HOST);
611 			ia->ia_ifa.ifa_dstaddr =
612 					(struct sockaddr *)&ia->ia_dstaddr;
613 			rtinit(&ia->ia_ifa, RTM_ADD, RTF_HOST | RTF_UP);
614 		}
615 		return (0);
616 
617 	case SIOCSIFBRDADDR:
618 		if ((ifp->if_flags & IFF_BROADCAST) == 0)
619 			return (EINVAL);
620 		ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr;
621 		return (0);
622 
623 	case SIOCSIFADDR:
624 		error = in_ifinit(ifp, ia,
625 		    (const struct sockaddr_in *)&ifr->ifr_addr, 1);
626 		if (error != 0 && iaIsNew)
627 			break;
628 		if (error == 0) {
629 			EVENTHANDLER_INVOKE(ifaddr_event, ifp,
630 			iaIsNew ? IFADDR_EVENT_ADD : IFADDR_EVENT_CHANGE,
631 			&ia->ia_ifa);
632 		}
633 		if (!ifpWasUp && (ifp->if_flags & IFF_UP)) {
634 			/*
635 			 * Interface is brought up by in_ifinit()
636 			 * (via ifp->if_ioctl).  We act as if the
637 			 * interface got IFF_UP flag turned on.
638 			 */
639 			if_up(ifp);
640 		}
641 		return (0);
642 
643 	case SIOCSIFNETMASK:
644 		ia->ia_sockmask.sin_addr = ifra->ifra_addr.sin_addr;
645 		ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr);
646 		return (0);
647 
648 	case SIOCAIFADDR:
649 		maskIsNew = 0;
650 		hostIsNew = 1;
651 		error = 0;
652 		if (ia->ia_addr.sin_family == AF_INET) {
653 			if (ifra->ifra_addr.sin_len == 0) {
654 				ifra->ifra_addr = ia->ia_addr;
655 				hostIsNew = 0;
656 			} else if (ifra->ifra_addr.sin_addr.s_addr ==
657 				   ia->ia_addr.sin_addr.s_addr) {
658 				hostIsNew = 0;
659 			}
660 		}
661 		if (ifra->ifra_mask.sin_len) {
662 			in_ifscrub(ifp, ia);
663 			ia->ia_sockmask = ifra->ifra_mask;
664 			ia->ia_sockmask.sin_family = AF_INET;
665 			ia->ia_subnetmask =
666 			    ntohl(ia->ia_sockmask.sin_addr.s_addr);
667 			maskIsNew = 1;
668 		}
669 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
670 		    ifra->ifra_dstaddr.sin_family == AF_INET) {
671 			in_ifscrub(ifp, ia);
672 			ia->ia_dstaddr = ifra->ifra_dstaddr;
673 			maskIsNew  = 1; /* We lie; but the effect's the same */
674 		}
675 		if (ifra->ifra_addr.sin_family == AF_INET &&
676 		    (hostIsNew || maskIsNew))
677 			error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
678 
679 		if (error != 0 && iaIsNew)
680 			break;
681 
682 		if ((ifp->if_flags & IFF_BROADCAST) &&
683 		    ifra->ifra_broadaddr.sin_family == AF_INET)
684 			ia->ia_broadaddr = ifra->ifra_broadaddr;
685 		if (error == 0) {
686 			EVENTHANDLER_INVOKE(ifaddr_event, ifp,
687 			iaIsNew ? IFADDR_EVENT_ADD : IFADDR_EVENT_CHANGE,
688 			&ia->ia_ifa);
689 		}
690 		if (!ifpWasUp && (ifp->if_flags & IFF_UP)) {
691 			/* See the comment in SIOCSIFADDR */
692 			if_up(ifp);
693 		}
694 		return (error);
695 
696 	case SIOCDIFADDR:
697 		/*
698 		 * in_ifscrub kills the interface route.
699 		 */
700 		in_ifscrub(ifp, ia);
701 		/*
702 		 * in_ifadown gets rid of all the rest of
703 		 * the routes.  This is not quite the right
704 		 * thing to do, but at least if we are running
705 		 * a routing process they will come back.
706 		 */
707 		in_ifadown(&ia->ia_ifa, 1);
708 		EVENTHANDLER_INVOKE(ifaddr_event, ifp, IFADDR_EVENT_DELETE,
709 				    &ia->ia_ifa);
710 		error = 0;
711 		break;
712 
713 	default:
714 		if (ifp == NULL || ifp->if_ioctl == NULL)
715 			return (EOPNOTSUPP);
716 		ifnet_serialize_all(ifp);
717 		error = ifp->if_ioctl(ifp, cmd, data, td->td_proc->p_ucred);
718 		ifnet_deserialize_all(ifp);
719 		return (error);
720 	}
721 
722 	KKASSERT(cmd == SIOCDIFADDR ||
723 		 ((cmd == SIOCAIFADDR || cmd == SIOCSIFADDR) && iaIsNew));
724 
725 	ifa_ifunlink(&ia->ia_ifa, ifp);
726 	in_iaunlink(ia);
727 
728 	if (cmd == SIOCDIFADDR) {
729 		ifac = &ia->ia_ifa.ifa_containers[mycpuid];
730 		if (ifac->ifa_listmask & IFA_LIST_IN_IFADDRHASH)
731 			in_iahash_remove(ia);
732 	}
733 #ifdef INVARIANTS
734 	else {
735 		/*
736 		 * If cmd is SIOCSIFADDR or SIOCAIFADDR, in_ifinit() has
737 		 * already taken care of the deletion from hash table
738 		 */
739 		ifac = &ia->ia_ifa.ifa_containers[mycpuid];
740 		KASSERT((ifac->ifa_listmask & IFA_LIST_IN_IFADDRHASH) == 0,
741 			("SIOC%cIFADDR failed on new ia, "
742 			 "but the new ia is still in hash table",
743 			 cmd == SIOCSIFADDR ? 'S' : 'A'));
744 	}
745 #endif
746 
747 	ifa_destroy(&ia->ia_ifa);
748 
749 	if ((cmd == SIOCAIFADDR || cmd == SIOCSIFADDR) &&
750 	    !ifpWasUp && (ifp->if_flags & IFF_UP)) {
751 		/*
752 		 * Though the address assignment failed, the
753 		 * interface is brought up by in_ifinit()
754 		 * (via ifp->if_ioctl).  With the hope that
755 		 * the interface has some valid addresses, we
756 		 * act as if IFF_UP flag was just set on the
757 		 * interface.
758 		 *
759 		 * NOTE:
760 		 * This could only be done after the failed
761 		 * address is unlinked from the global address
762 		 * list.
763 		 */
764 		if_up(ifp);
765 	}
766 
767 	return (error);
768 }
769 
770 /*
771  * SIOC[GAD]LIFADDR.
772  *	SIOCGLIFADDR: get first address. (?!?)
773  *	SIOCGLIFADDR with IFLR_PREFIX:
774  *		get first address that matches the specified prefix.
775  *	SIOCALIFADDR: add the specified address.
776  *	SIOCALIFADDR with IFLR_PREFIX:
777  *		EINVAL since we can't deduce hostid part of the address.
778  *	SIOCDLIFADDR: delete the specified address.
779  *	SIOCDLIFADDR with IFLR_PREFIX:
780  *		delete the first address that matches the specified prefix.
781  * return values:
782  *	EINVAL on invalid parameters
783  *	EADDRNOTAVAIL on prefix match failed/specified address not found
784  *	other values may be returned from in_ioctl()
785  *
786  * NOTE! td might be NULL.
787  */
788 static int
789 in_lifaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct thread *td)
790 {
791 	struct if_laddrreq *iflr = (struct if_laddrreq *)data;
792 
793 	/* sanity checks */
794 	if (!data || !ifp) {
795 		panic("invalid argument to in_lifaddr_ioctl");
796 		/*NOTRECHED*/
797 	}
798 
799 	switch (cmd) {
800 	case SIOCGLIFADDR:
801 		/* address must be specified on GET with IFLR_PREFIX */
802 		if ((iflr->flags & IFLR_PREFIX) == 0)
803 			break;
804 		/*FALLTHROUGH*/
805 	case SIOCALIFADDR:
806 	case SIOCDLIFADDR:
807 		/* address must be specified on ADD and DELETE */
808 		if (iflr->addr.ss_family != AF_INET)
809 			return EINVAL;
810 		if (iflr->addr.ss_len != sizeof(struct sockaddr_in))
811 			return EINVAL;
812 		/* XXX need improvement */
813 		if (iflr->dstaddr.ss_family
814 		 && iflr->dstaddr.ss_family != AF_INET)
815 			return EINVAL;
816 		if (iflr->dstaddr.ss_family
817 		 && iflr->dstaddr.ss_len != sizeof(struct sockaddr_in))
818 			return EINVAL;
819 		break;
820 	default: /*shouldn't happen*/
821 		return EOPNOTSUPP;
822 	}
823 	if (sizeof(struct in_addr) * 8 < iflr->prefixlen)
824 		return EINVAL;
825 
826 	switch (cmd) {
827 	case SIOCALIFADDR:
828 	    {
829 		struct in_aliasreq ifra;
830 
831 		if (iflr->flags & IFLR_PREFIX)
832 			return EINVAL;
833 
834 		/* copy args to in_aliasreq, perform ioctl(SIOCAIFADDR_IN6). */
835 		bzero(&ifra, sizeof ifra);
836 		bcopy(iflr->iflr_name, ifra.ifra_name, sizeof ifra.ifra_name);
837 
838 		bcopy(&iflr->addr, &ifra.ifra_addr, iflr->addr.ss_len);
839 
840 		if (iflr->dstaddr.ss_family) {	/*XXX*/
841 			bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
842 				iflr->dstaddr.ss_len);
843 		}
844 
845 		ifra.ifra_mask.sin_family = AF_INET;
846 		ifra.ifra_mask.sin_len = sizeof(struct sockaddr_in);
847 		in_len2mask(&ifra.ifra_mask.sin_addr, iflr->prefixlen);
848 
849 		return in_control_internal(SIOCAIFADDR, (caddr_t)&ifra, ifp,
850 		    td);
851 	    }
852 	case SIOCGLIFADDR:
853 	case SIOCDLIFADDR:
854 	    {
855 		struct ifaddr_container *ifac;
856 		struct in_ifaddr *ia;
857 		struct in_addr mask, candidate, match;
858 		struct sockaddr_in *sin;
859 		int cmp;
860 
861 		bzero(&mask, sizeof mask);
862 		if (iflr->flags & IFLR_PREFIX) {
863 			/* lookup a prefix rather than address. */
864 			in_len2mask(&mask, iflr->prefixlen);
865 
866 			sin = (struct sockaddr_in *)&iflr->addr;
867 			match.s_addr = sin->sin_addr.s_addr;
868 			match.s_addr &= mask.s_addr;
869 
870 			/* if you set extra bits, that's wrong */
871 			if (match.s_addr != sin->sin_addr.s_addr)
872 				return EINVAL;
873 
874 			cmp = 1;
875 		} else {
876 			if (cmd == SIOCGLIFADDR) {
877 				/* on getting an address, take the 1st match */
878 				match.s_addr = 0; /* gcc4 warning */
879 				cmp = 0;	/*XXX*/
880 			} else {
881 				/* on deleting an address, do exact match */
882 				in_len2mask(&mask, 32);
883 				sin = (struct sockaddr_in *)&iflr->addr;
884 				match.s_addr = sin->sin_addr.s_addr;
885 
886 				cmp = 1;
887 			}
888 		}
889 
890 		TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
891 			struct ifaddr *ifa = ifac->ifa;
892 
893 			if (ifa->ifa_addr->sa_family != AF_INET6)
894 				continue;
895 			if (!cmp)
896 				break;
897 			candidate.s_addr =
898 			((struct sockaddr_in *)&ifa->ifa_addr)->sin_addr.s_addr;
899 			candidate.s_addr &= mask.s_addr;
900 			if (candidate.s_addr == match.s_addr)
901 				break;
902 		}
903 		if (ifac == NULL)
904 			return EADDRNOTAVAIL;
905 		ia = (struct in_ifaddr *)(ifac->ifa);
906 
907 		if (cmd == SIOCGLIFADDR) {
908 			/* fill in the if_laddrreq structure */
909 			bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin_len);
910 
911 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
912 				bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
913 					ia->ia_dstaddr.sin_len);
914 			} else
915 				bzero(&iflr->dstaddr, sizeof iflr->dstaddr);
916 
917 			iflr->prefixlen =
918 				in_mask2len(&ia->ia_sockmask.sin_addr);
919 
920 			iflr->flags = 0;	/*XXX*/
921 
922 			return 0;
923 		} else {
924 			struct in_aliasreq ifra;
925 
926 			/* fill in_aliasreq and do ioctl(SIOCDIFADDR_IN6) */
927 			bzero(&ifra, sizeof ifra);
928 			bcopy(iflr->iflr_name, ifra.ifra_name,
929 				sizeof ifra.ifra_name);
930 
931 			bcopy(&ia->ia_addr, &ifra.ifra_addr,
932 				ia->ia_addr.sin_len);
933 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
934 				bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
935 					ia->ia_dstaddr.sin_len);
936 			}
937 			bcopy(&ia->ia_sockmask, &ifra.ifra_dstaddr,
938 				ia->ia_sockmask.sin_len);
939 
940 			return in_control_internal(SIOCDIFADDR, (caddr_t)&ifra,
941 			    ifp, td);
942 		}
943 	    }
944 	}
945 
946 	return EOPNOTSUPP;	/*just for safety*/
947 }
948 
949 /*
950  * Delete any existing route for an interface.
951  */
952 void
953 in_ifscrub(struct ifnet *ifp __unused, struct in_ifaddr *ia)
954 {
955 	in_scrubprefix(ia);
956 }
957 
958 /*
959  * Initialize an interface's internet address
960  * and routing table entry.
961  */
962 static int
963 in_ifinit(struct ifnet *ifp, struct in_ifaddr *ia,
964 	  const struct sockaddr_in *sin, int scrub)
965 {
966 	u_long i = ntohl(sin->sin_addr.s_addr);
967 	struct sockaddr_in oldaddr;
968 	struct ifaddr_container *ifac;
969 	int flags = RTF_UP, error = 0;
970 	int was_hash = 0;
971 
972 	ifac = &ia->ia_ifa.ifa_containers[mycpuid];
973 	oldaddr = ia->ia_addr;
974 
975 	if (ifac->ifa_listmask & IFA_LIST_IN_IFADDRHASH) {
976 		was_hash = 1;
977 		in_iahash_remove(ia);
978 	}
979 
980 	ia->ia_addr = *sin;
981 	if (ia->ia_addr.sin_family == AF_INET)
982 		in_iahash_insert(ia);
983 
984 	/*
985 	 * Give the interface a chance to initialize
986 	 * if this is its first address,
987 	 * and to validate the address if necessary.
988 	 */
989 	if (ifp->if_ioctl != NULL) {
990 		ifnet_serialize_all(ifp);
991 		error = ifp->if_ioctl(ifp, SIOCSIFADDR, (caddr_t)ia, NULL);
992 		ifnet_deserialize_all(ifp);
993 		if (error)
994 			goto fail;
995 	}
996 
997 	/*
998 	 * Delete old route, if requested.
999 	 */
1000 	if (scrub) {
1001 		ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr;
1002 		in_ifscrub(ifp, ia);
1003 		ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
1004 	}
1005 
1006 	/*
1007 	 * Calculate netmask/subnetmask.
1008 	 */
1009 	if (IN_CLASSA(i))
1010 		ia->ia_netmask = IN_CLASSA_NET;
1011 	else if (IN_CLASSB(i))
1012 		ia->ia_netmask = IN_CLASSB_NET;
1013 	else
1014 		ia->ia_netmask = IN_CLASSC_NET;
1015 	/*
1016 	 * The subnet mask usually includes at least the standard network part,
1017 	 * but may may be smaller in the case of supernetting.
1018 	 * If it is set, we believe it.
1019 	 */
1020 	if (ia->ia_subnetmask == 0) {
1021 		ia->ia_subnetmask = ia->ia_netmask;
1022 		ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
1023 	} else {
1024 		ia->ia_netmask &= ia->ia_subnetmask;
1025 	}
1026 	ia->ia_net = i & ia->ia_netmask;
1027 	ia->ia_subnet = i & ia->ia_subnetmask;
1028 	in_socktrim(&ia->ia_sockmask);
1029 
1030 	/*
1031 	 * Add route for the network.
1032 	 */
1033 	ia->ia_ifa.ifa_metric = ifp->if_metric;
1034 	if (ifp->if_flags & IFF_BROADCAST) {
1035 		ia->ia_broadaddr.sin_addr.s_addr =
1036 			htonl(ia->ia_subnet | ~ia->ia_subnetmask);
1037 		ia->ia_netbroadcast.s_addr =
1038 			htonl(ia->ia_net | ~ ia->ia_netmask);
1039 	} else if (ifp->if_flags & IFF_LOOPBACK) {
1040 		ia->ia_dstaddr = ia->ia_addr;
1041 		flags |= RTF_HOST;
1042 	} else if (ifp->if_flags & IFF_POINTOPOINT) {
1043 		if (ia->ia_dstaddr.sin_family != AF_INET)
1044 			return (0);
1045 		flags |= RTF_HOST;
1046 	}
1047 
1048 	/*-
1049 	 * Don't add host routes for interface addresses of
1050 	 * 0.0.0.0 --> 0.255.255.255 netmask 255.0.0.0.  This makes it
1051 	 * possible to assign several such address pairs with consistent
1052 	 * results (no host route) and is required by BOOTP.
1053 	 *
1054 	 * XXX: This is ugly !  There should be a way for the caller to
1055 	 *      say that they don't want a host route.
1056 	 */
1057 	if (ia->ia_addr.sin_addr.s_addr != INADDR_ANY ||
1058 	    ia->ia_netmask != IN_CLASSA_NET ||
1059 	    ia->ia_dstaddr.sin_addr.s_addr != htonl(IN_CLASSA_HOST)) {
1060 		error = in_addprefix(ia, flags);
1061 		if (error)
1062 			goto fail;
1063 	}
1064 
1065 	/*
1066 	 * If the interface supports multicast, join the "all hosts"
1067 	 * multicast group on that interface.
1068 	 */
1069 	if (ifp->if_flags & IFF_MULTICAST) {
1070 		struct in_addr addr;
1071 
1072 		addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
1073 		in_addmulti(&addr, ifp);
1074 	}
1075 	return (0);
1076 fail:
1077 	if (ifac->ifa_listmask & IFA_LIST_IN_IFADDRHASH)
1078 		in_iahash_remove(ia);
1079 
1080 	ia->ia_addr = oldaddr;
1081 	if (was_hash)
1082 		in_iahash_insert(ia);
1083 	return (error);
1084 }
1085 
1086 #define rtinitflags(x) \
1087 	(((x)->ia_ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) \
1088 	 ? RTF_HOST : 0)
1089 
1090 /*
1091  * Add a route to prefix ("connected route" in cisco terminology).
1092  * Do nothing, if there are some interface addresses with the same
1093  * prefix already.  This function assumes that the 'target' parent
1094  * interface is UP.
1095  */
1096 static int
1097 in_addprefix(struct in_ifaddr *target, int flags)
1098 {
1099 	struct in_ifaddr_container *iac;
1100 	struct in_addr prefix, mask;
1101 	int error;
1102 
1103 #ifdef CARP
1104 	/*
1105 	 * Don't add prefix routes for CARP interfaces.
1106 	 * Prefix routes creation is handled by CARP
1107 	 * interfaces themselves.
1108 	 */
1109 	if (target->ia_ifp->if_type == IFT_CARP)
1110 		return 0;
1111 #endif
1112 
1113 	mask = target->ia_sockmask.sin_addr;
1114 	if (flags & RTF_HOST) {
1115 		prefix = target->ia_dstaddr.sin_addr;
1116 	} else {
1117 		prefix = target->ia_addr.sin_addr;
1118 		prefix.s_addr &= mask.s_addr;
1119 	}
1120 
1121 	TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) {
1122 		struct in_ifaddr *ia = iac->ia;
1123 		struct in_addr p;
1124 
1125 		/* Don't test against self */
1126 		if (ia == target)
1127 			continue;
1128 
1129 		/* The tested address does not own a route entry */
1130 		if ((ia->ia_flags & IFA_ROUTE) == 0)
1131 			continue;
1132 
1133 		/* Prefix test */
1134 		if (rtinitflags(ia)) {
1135 			p = ia->ia_dstaddr.sin_addr;
1136 		} else {
1137 			p = ia->ia_addr.sin_addr;
1138 			p.s_addr &= ia->ia_sockmask.sin_addr.s_addr;
1139 		}
1140 		if (prefix.s_addr != p.s_addr)
1141 			continue;
1142 
1143 		/*
1144 		 * If the to-be-added address and the curretly being
1145 		 * tested address are not host addresses, we need to
1146 		 * take subnetmask into consideration.
1147 		 */
1148 		if (!(flags & RTF_HOST) && !rtinitflags(ia) &&
1149 		    mask.s_addr != ia->ia_sockmask.sin_addr.s_addr)
1150 			continue;
1151 
1152 		/*
1153 		 * If we got a matching prefix route inserted by other
1154 		 * interface address, we don't need to bother.
1155 		 */
1156 		return 0;
1157 	}
1158 
1159 	/*
1160 	 * No one seem to have prefix route; insert it.
1161 	 */
1162 	error = rtinit(&target->ia_ifa, RTM_ADD, flags);
1163 	if (!error)
1164 		target->ia_flags |= IFA_ROUTE;
1165 	return error;
1166 }
1167 
1168 /*
1169  * Remove a route to prefix ("connected route" in cisco terminology).
1170  * Re-installs the route by using another interface address, if there's
1171  * one with the same prefix (otherwise we lose the route mistakenly).
1172  */
1173 static void
1174 in_scrubprefix(struct in_ifaddr *target)
1175 {
1176 	struct in_ifaddr_container *iac;
1177 	struct in_addr prefix, mask;
1178 	int error;
1179 
1180 #ifdef CARP
1181 	/*
1182 	 * Don't scrub prefix routes for CARP interfaces.
1183 	 * Prefix routes deletion is handled by CARP
1184 	 * interfaces themselves.
1185 	 */
1186 	if (target->ia_ifp->if_type == IFT_CARP)
1187 		return;
1188 #endif
1189 
1190 	if ((target->ia_flags & IFA_ROUTE) == 0)
1191 		return;
1192 
1193 	mask = target->ia_sockmask.sin_addr;
1194 	if (rtinitflags(target)) {
1195 		prefix = target->ia_dstaddr.sin_addr;
1196 	} else {
1197 		prefix = target->ia_addr.sin_addr;
1198 		prefix.s_addr &= mask.s_addr;
1199 	}
1200 
1201 	TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) {
1202 		struct in_ifaddr *ia = iac->ia;
1203 		struct in_addr p;
1204 
1205 		/* Don't test against self */
1206 		if (ia == target)
1207 			continue;
1208 
1209 		/* The tested address already owns a route entry */
1210 		if (ia->ia_flags & IFA_ROUTE)
1211 			continue;
1212 
1213 		/*
1214 		 * The prefix route of the tested address should
1215 		 * never be installed if its parent interface is
1216 		 * not UP yet.
1217 		 */
1218 		if ((ia->ia_ifp->if_flags & IFF_UP) == 0)
1219 			continue;
1220 
1221 #ifdef CARP
1222 		/*
1223 		 * Don't add prefix routes for CARP interfaces.
1224 		 * Prefix routes creation is handled by CARP
1225 		 * interfaces themselves.
1226 		 */
1227 		if (ia->ia_ifp->if_type == IFT_CARP)
1228 			continue;
1229 #endif
1230 
1231 		/* Prefix test */
1232 		if (rtinitflags(ia)) {
1233 			p = ia->ia_dstaddr.sin_addr;
1234 		} else {
1235 			p = ia->ia_addr.sin_addr;
1236 			p.s_addr &= ia->ia_sockmask.sin_addr.s_addr;
1237 		}
1238 		if (prefix.s_addr != p.s_addr)
1239 			continue;
1240 
1241 		/*
1242 		 * We don't need to test subnetmask here, as what we do
1243 		 * in in_addprefix(), since if the the tested address's
1244 		 * parent interface is UP, the tested address should own
1245 		 * a prefix route entry and we would never reach here.
1246 		 */
1247 
1248 		/*
1249 		 * If we got a matching prefix route, move IFA_ROUTE to him
1250 		 */
1251 		rtinit(&target->ia_ifa, RTM_DELETE, rtinitflags(target));
1252 		target->ia_flags &= ~IFA_ROUTE;
1253 
1254 		error = rtinit(&ia->ia_ifa, RTM_ADD, rtinitflags(ia) | RTF_UP);
1255 		if (!error)
1256 			ia->ia_flags |= IFA_ROUTE;
1257 		return;
1258 	}
1259 
1260 	/*
1261 	 * No candidates for this prefix route; just remove it.
1262 	 */
1263 	rtinit(&target->ia_ifa, RTM_DELETE, rtinitflags(target));
1264 	target->ia_flags &= ~IFA_ROUTE;
1265 }
1266 
1267 #undef rtinitflags
1268 
1269 /*
1270  * Return 1 if the address might be a local broadcast address.
1271  */
1272 int
1273 in_broadcast(struct in_addr in, struct ifnet *ifp)
1274 {
1275 	struct ifaddr_container *ifac;
1276 	u_long t;
1277 
1278 	if (in.s_addr == INADDR_BROADCAST ||
1279 	    in.s_addr == INADDR_ANY)
1280 		return 1;
1281 	if (ifp == NULL || (ifp->if_flags & IFF_BROADCAST) == 0)
1282 		return 0;
1283 	t = ntohl(in.s_addr);
1284 	/*
1285 	 * Look through the list of addresses for a match
1286 	 * with a broadcast address.
1287 	 */
1288 #define ia ((struct in_ifaddr *)ifa)
1289 	TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
1290 		struct ifaddr *ifa = ifac->ifa;
1291 
1292 		if (ifa->ifa_addr->sa_family == AF_INET &&
1293 		    (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
1294 		     in.s_addr == ia->ia_netbroadcast.s_addr ||
1295 		     /*
1296 		      * Check for old-style (host 0) broadcast.
1297 		      */
1298 		     t == ia->ia_subnet || t == ia->ia_net) &&
1299 		     /*
1300 		      * Check for an all one subnetmask. These
1301 		      * only exist when an interface gets a secondary
1302 		      * address.
1303 		      */
1304 		     ia->ia_subnetmask != (u_long)0xffffffff)
1305 			    return 1;
1306 	}
1307 	return (0);
1308 #undef ia
1309 }
1310 
1311 /*
1312  * Add an address to the list of IP multicast addresses for a given interface.
1313  */
1314 struct in_multi *
1315 in_addmulti(struct in_addr *ap, struct ifnet *ifp)
1316 {
1317 	struct in_multi *inm;
1318 	int error;
1319 	struct sockaddr_in sin;
1320 	struct ifmultiaddr *ifma;
1321 
1322 	KASSERT(&curthread->td_msgport == netisr_cpuport(0),
1323 	    ("in_addmulti is not called in netisr0"));
1324 
1325 	/*
1326 	 * Call generic routine to add membership or increment
1327 	 * refcount.  It wants addresses in the form of a sockaddr,
1328 	 * so we build one here (being careful to zero the unused bytes).
1329 	 */
1330 	bzero(&sin, sizeof sin);
1331 	sin.sin_family = AF_INET;
1332 	sin.sin_len = sizeof sin;
1333 	sin.sin_addr = *ap;
1334 	error = if_addmulti(ifp, (struct sockaddr *)&sin, &ifma);
1335 	if (error)
1336 		return NULL;
1337 
1338 	/*
1339 	 * If ifma->ifma_protospec is null, then if_addmulti() created
1340 	 * a new record.  Otherwise, we are done.
1341 	 */
1342 	if (ifma->ifma_protospec != NULL)
1343 		return ifma->ifma_protospec;
1344 
1345 	inm = kmalloc(sizeof *inm, M_IPMADDR, M_WAITOK | M_ZERO);
1346 	inm->inm_addr = *ap;
1347 	inm->inm_ifp = ifp;
1348 	inm->inm_ifma = ifma;
1349 	ifma->ifma_protospec = inm;
1350 	LIST_INSERT_HEAD(&in_multihead, inm, inm_link);
1351 
1352 	/*
1353 	 * Let IGMP know that we have joined a new IP multicast group.
1354 	 */
1355 	igmp_joingroup(inm);
1356 	return inm;
1357 }
1358 
1359 /*
1360  * Delete a multicast address record.
1361  */
1362 void
1363 in_delmulti(struct in_multi *inm)
1364 {
1365 	struct ifmultiaddr *ifma;
1366 	struct in_multi my_inm;
1367 
1368 	KASSERT(&curthread->td_msgport == netisr_cpuport(0),
1369 	    ("in_delmulti is not called in netisr0"));
1370 
1371 	ifma = inm->inm_ifma;
1372 	my_inm.inm_ifp = NULL ; /* don't send the leave msg */
1373 	if (ifma->ifma_refcount == 1) {
1374 		/*
1375 		 * No remaining claims to this record; let IGMP know that
1376 		 * we are leaving the multicast group.
1377 		 * But do it after the if_delmulti() which might reset
1378 		 * the interface and nuke the packet.
1379 		 */
1380 		my_inm = *inm ;
1381 		ifma->ifma_protospec = NULL;
1382 		LIST_REMOVE(inm, inm_link);
1383 		kfree(inm, M_IPMADDR);
1384 	}
1385 	/* XXX - should be separate API for when we have an ifma? */
1386 	if_delmulti(ifma->ifma_ifp, ifma->ifma_addr);
1387 	if (my_inm.inm_ifp != NULL)
1388 		igmp_leavegroup(&my_inm);
1389 }
1390 
1391 static void
1392 in_ifdetach_dispatch(netmsg_t nmsg)
1393 {
1394 	struct lwkt_msg *lmsg = &nmsg->lmsg;
1395 	struct ifnet *ifp = lmsg->u.ms_resultp;
1396 	int cpu;
1397 
1398 	in_pcbpurgeif0(&ripcbinfo, ifp);
1399 	for (cpu = 0; cpu < ncpus2; ++cpu)
1400 		in_pcbpurgeif0(&udbinfo[cpu], ifp);
1401 
1402 	lwkt_replymsg(lmsg, 0);
1403 }
1404 
1405 void
1406 in_ifdetach(struct ifnet *ifp)
1407 {
1408 	struct netmsg_base nmsg;
1409 	struct lwkt_msg *lmsg = &nmsg.lmsg;
1410 
1411 	netmsg_init(&nmsg, NULL, &curthread->td_msgport, 0,
1412 	    in_ifdetach_dispatch);
1413 	lmsg->u.ms_resultp = ifp;
1414 
1415 	lwkt_domsg(netisr_cpuport(0), lmsg, 0);
1416 }
1417