xref: /dragonfly/sys/netinet/in.c (revision 926deccb)
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 (struct socket *, u_long, caddr_t,
67 	struct ifnet *, struct thread *);
68 
69 static void	in_socktrim (struct sockaddr_in *);
70 static int	in_ifinit(struct ifnet *, struct in_ifaddr *,
71 		    const struct sockaddr_in *, int);
72 
73 static int	in_control_internal(u_long, caddr_t, struct ifnet *,
74 		    struct thread *);
75 static int	in_control_redispatch(u_long, caddr_t, struct ifnet *,
76 		    struct thread *);
77 
78 static int	in_addprefix(struct in_ifaddr *, int);
79 static void	in_scrubprefix(struct in_ifaddr *);
80 
81 static int subnetsarelocal = 0;
82 SYSCTL_INT(_net_inet_ip, OID_AUTO, subnets_are_local, CTLFLAG_RW,
83     &subnetsarelocal, 0,
84     "Count all internet addresses of subnets of the local net as local");
85 
86 struct in_multihead in_multihead; /* XXX BSS initialization */
87 
88 extern struct inpcbinfo ripcbinfo;
89 
90 /*
91  * Return 1 if an internet address is for a ``local'' host
92  * (one to which we have a connection).  If subnetsarelocal
93  * is true, this includes other subnets of the local net.
94  * Otherwise, it includes only the directly-connected (sub)nets.
95  */
96 int
97 in_localaddr(struct in_addr in)
98 {
99 	u_long i = ntohl(in.s_addr);
100 	struct in_ifaddr_container *iac;
101 	struct in_ifaddr *ia;
102 
103 	if (subnetsarelocal) {
104 		TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) {
105 			ia = iac->ia;
106 
107 			if ((i & ia->ia_netmask) == ia->ia_net)
108 				return (1);
109 		}
110 	} else {
111 		TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) {
112 			ia = iac->ia;
113 
114 			if ((i & ia->ia_subnetmask) == ia->ia_subnet)
115 				return (1);
116 		}
117 	}
118 	return (0);
119 }
120 
121 /*
122  * Determine whether an IP address is in a reserved set of addresses
123  * that may not be forwarded, or whether datagrams to that destination
124  * may be forwarded.
125  */
126 int
127 in_canforward(struct in_addr in)
128 {
129 	u_long i = ntohl(in.s_addr);
130 	u_long net;
131 
132 	if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i))
133 		return (0);
134 	if (IN_CLASSA(i)) {
135 		net = i & IN_CLASSA_NET;
136 		if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
137 			return (0);
138 	}
139 	return (1);
140 }
141 
142 /*
143  * Trim a mask in a sockaddr
144  */
145 static void
146 in_socktrim(struct sockaddr_in *ap)
147 {
148     char *cplim = (char *) &ap->sin_addr;
149     char *cp = (char *) (&ap->sin_addr + 1);
150 
151     ap->sin_len = 0;
152     while (--cp >= cplim)
153 	if (*cp) {
154 	    (ap)->sin_len = cp - (char *) (ap) + 1;
155 	    break;
156 	}
157 }
158 
159 static int
160 in_mask2len(struct in_addr *mask)
161 {
162 	int x, y;
163 	u_char *p;
164 
165 	p = (u_char *)mask;
166 	for (x = 0; x < sizeof *mask; x++) {
167 		if (p[x] != 0xff)
168 			break;
169 	}
170 	y = 0;
171 	if (x < sizeof *mask) {
172 		for (y = 0; y < 8; y++) {
173 			if ((p[x] & (0x80 >> y)) == 0)
174 				break;
175 		}
176 	}
177 	return x * 8 + y;
178 }
179 
180 static void
181 in_len2mask(struct in_addr *mask, int len)
182 {
183 	int i;
184 	u_char *p;
185 
186 	p = (u_char *)mask;
187 	bzero(mask, sizeof *mask);
188 	for (i = 0; i < len / 8; i++)
189 		p[i] = 0xff;
190 	if (len % 8)
191 		p[i] = (0xff00 >> (len % 8)) & 0xff;
192 }
193 
194 static int in_interfaces;	/* number of external internet interfaces */
195 
196 void
197 in_control_dispatch(netmsg_t msg)
198 {
199 	int error;
200 
201 	error = in_control_redispatch(msg->control.nm_cmd,
202 				      msg->control.nm_data,
203 				      msg->control.nm_ifp,
204 				      msg->control.nm_td);
205 	lwkt_replymsg(&msg->lmsg, error);
206 }
207 
208 static void
209 in_control_internal_dispatch(netmsg_t msg)
210 {
211 	int error;
212 
213 	error = in_control_internal(msg->control.nm_cmd,
214 				    msg->control.nm_data,
215 				    msg->control.nm_ifp,
216 				    msg->control.nm_td);
217 	lwkt_replymsg(&msg->lmsg, error);
218 }
219 
220 static int
221 in_control_redispatch(u_long cmd, caddr_t data, struct ifnet *ifp,
222 		      struct thread *td)
223 {
224 	struct netmsg_pru_control msg;
225 	int error;
226 
227 	/*
228 	 * IFADDR alterations are serialized by netisr0
229 	 */
230 	switch (cmd) {
231 	case SIOCSIFDSTADDR:
232 	case SIOCSIFBRDADDR:
233 	case SIOCSIFADDR:
234 	case SIOCSIFNETMASK:
235 	case SIOCAIFADDR:
236 	case SIOCDIFADDR:
237 		netmsg_init(&msg.base, NULL, &curthread->td_msgport,
238 			    0, in_control_internal_dispatch);
239 		msg.nm_cmd = cmd;
240 		msg.nm_data = data;
241 		msg.nm_ifp = ifp;
242 		msg.nm_td = td;
243 		lwkt_domsg(netisr_cpuport(0), &msg.base.lmsg, 0);
244 		error = msg.base.lmsg.ms_error;
245 		break;
246 
247 	default:
248 		error = in_control_internal(cmd, data, ifp, td);
249 		break;
250 	}
251 	return error;
252 }
253 
254 /*
255  * Generic internet control operations (ioctl's).
256  * Ifp is 0 if not an interface-specific ioctl.
257  *
258  * NOTE! td might be NULL.
259  */
260 /* ARGSUSED */
261 int
262 in_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
263 	   struct thread *td)
264 {
265 	int error;
266 
267 	switch (cmd) {
268 	case SIOCALIFADDR:
269 	case SIOCDLIFADDR:
270 		if (td && (error = priv_check(td, PRIV_ROOT)) != 0)
271 			return error;
272 		/* FALLTHROUGH */
273 	case SIOCGLIFADDR:
274 		if (!ifp)
275 			return EINVAL;
276 		return in_lifaddr_ioctl(so, cmd, data, ifp, td);
277 	}
278 
279 	KASSERT(cmd != SIOCALIFADDR && cmd != SIOCDLIFADDR,
280 		("recursive SIOC%cLIFADDR!",
281 		 cmd == SIOCDLIFADDR ? 'D' : 'A'));
282 
283 	return in_control_redispatch(cmd, data, ifp, td);
284 }
285 
286 static void
287 in_ialink_dispatch(netmsg_t msg)
288 {
289 	struct in_ifaddr *ia = msg->lmsg.u.ms_resultp;
290 	struct ifaddr_container *ifac;
291 	struct in_ifaddr_container *iac;
292 	int cpu = mycpuid;
293 
294 	crit_enter();
295 
296 	ifac = &ia->ia_ifa.ifa_containers[cpu];
297 	ASSERT_IFAC_VALID(ifac);
298 	KASSERT((ifac->ifa_listmask & IFA_LIST_IN_IFADDRHEAD) == 0,
299 		("ia is on in_ifaddrheads"));
300 
301 	ifac->ifa_listmask |= IFA_LIST_IN_IFADDRHEAD;
302 	iac = &ifac->ifa_proto_u.u_in_ifac;
303 	TAILQ_INSERT_TAIL(&in_ifaddrheads[cpu], iac, ia_link);
304 
305 	crit_exit();
306 
307 	ifa_forwardmsg(&msg->lmsg, cpu + 1);
308 }
309 
310 static void
311 in_iaunlink_dispatch(netmsg_t msg)
312 {
313 	struct in_ifaddr *ia = msg->lmsg.u.ms_resultp;
314 	struct ifaddr_container *ifac;
315 	struct in_ifaddr_container *iac;
316 	int cpu = mycpuid;
317 
318 	crit_enter();
319 
320 	ifac = &ia->ia_ifa.ifa_containers[cpu];
321 	ASSERT_IFAC_VALID(ifac);
322 	KASSERT(ifac->ifa_listmask & IFA_LIST_IN_IFADDRHEAD,
323 		("ia is not on in_ifaddrheads"));
324 
325 	iac = &ifac->ifa_proto_u.u_in_ifac;
326 	TAILQ_REMOVE(&in_ifaddrheads[cpu], iac, ia_link);
327 	ifac->ifa_listmask &= ~IFA_LIST_IN_IFADDRHEAD;
328 
329 	crit_exit();
330 
331 	ifa_forwardmsg(&msg->lmsg, cpu + 1);
332 }
333 
334 static void
335 in_iahashins_dispatch(netmsg_t msg)
336 {
337 	struct in_ifaddr *ia = msg->lmsg.u.ms_resultp;
338 	struct ifaddr_container *ifac;
339 	struct in_ifaddr_container *iac;
340 	int cpu = mycpuid;
341 
342 	crit_enter();
343 
344 	ifac = &ia->ia_ifa.ifa_containers[cpu];
345 	ASSERT_IFAC_VALID(ifac);
346 	KASSERT((ifac->ifa_listmask & IFA_LIST_IN_IFADDRHASH) == 0,
347 		("ia is on in_ifaddrhashtbls"));
348 
349 	ifac->ifa_listmask |= IFA_LIST_IN_IFADDRHASH;
350 	iac = &ifac->ifa_proto_u.u_in_ifac;
351 	LIST_INSERT_HEAD(INADDR_HASH(ia->ia_addr.sin_addr.s_addr),
352 			 iac, ia_hash);
353 
354 	crit_exit();
355 
356 	ifa_forwardmsg(&msg->lmsg, cpu + 1);
357 }
358 
359 static void
360 in_iahashrem_dispatch(netmsg_t msg)
361 {
362 	struct in_ifaddr *ia = msg->lmsg.u.ms_resultp;
363 	struct ifaddr_container *ifac;
364 	struct in_ifaddr_container *iac;
365 	int cpu = mycpuid;
366 
367 	crit_enter();
368 
369 	ifac = &ia->ia_ifa.ifa_containers[cpu];
370 	ASSERT_IFAC_VALID(ifac);
371 	KASSERT(ifac->ifa_listmask & IFA_LIST_IN_IFADDRHASH,
372 		("ia is not on in_ifaddrhashtbls"));
373 
374 	iac = &ifac->ifa_proto_u.u_in_ifac;
375 	LIST_REMOVE(iac, ia_hash);
376 	ifac->ifa_listmask &= ~IFA_LIST_IN_IFADDRHASH;
377 
378 	crit_exit();
379 
380 	ifa_forwardmsg(&msg->lmsg, cpu + 1);
381 }
382 
383 static void
384 in_ialink(struct in_ifaddr *ia)
385 {
386 	struct netmsg_base msg;
387 
388 	netmsg_init(&msg, NULL, &curthread->td_msgport,
389 		    0, in_ialink_dispatch);
390 	msg.lmsg.u.ms_resultp = ia;
391 
392 	ifa_domsg(&msg.lmsg, 0);
393 }
394 
395 void
396 in_iaunlink(struct in_ifaddr *ia)
397 {
398 	struct netmsg_base msg;
399 
400 	netmsg_init(&msg, NULL, &curthread->td_msgport,
401 		    0, in_iaunlink_dispatch);
402 	msg.lmsg.u.ms_resultp = ia;
403 
404 	ifa_domsg(&msg.lmsg, 0);
405 }
406 
407 void
408 in_iahash_insert(struct in_ifaddr *ia)
409 {
410 	struct netmsg_base msg;
411 
412 	netmsg_init(&msg, NULL, &curthread->td_msgport,
413 		    0, in_iahashins_dispatch);
414 	msg.lmsg.u.ms_resultp = ia;
415 
416 	ifa_domsg(&msg.lmsg, 0);
417 }
418 
419 void
420 in_iahash_remove(struct in_ifaddr *ia)
421 {
422 	struct netmsg_base msg;
423 
424 	netmsg_init(&msg, NULL, &curthread->td_msgport,
425 		    0, in_iahashrem_dispatch);
426 	msg.lmsg.u.ms_resultp = ia;
427 
428 	ifa_domsg(&msg.lmsg, 0);
429 }
430 
431 static __inline struct in_ifaddr *
432 in_ianext(struct in_ifaddr *oia)
433 {
434 	struct ifaddr_container *ifac;
435 	struct in_ifaddr_container *iac;
436 
437 	ifac = &oia->ia_ifa.ifa_containers[mycpuid];
438 	ASSERT_IFAC_VALID(ifac);
439 	KASSERT(ifac->ifa_listmask & IFA_LIST_IN_IFADDRHEAD,
440 		("ia is not on in_ifaddrheads"));
441 
442 	iac = &ifac->ifa_proto_u.u_in_ifac;
443 	iac = TAILQ_NEXT(iac, ia_link);
444 	if (iac != NULL)
445 		return iac->ia;
446 	else
447 		return NULL;
448 }
449 
450 static int
451 in_control_internal(u_long cmd, caddr_t data, struct ifnet *ifp,
452 		    struct thread *td)
453 {
454 	struct ifreq *ifr = (struct ifreq *)data;
455 	struct in_ifaddr *ia = NULL;
456 	struct in_addr dst;
457 	struct in_aliasreq *ifra = (struct in_aliasreq *)data;
458 	struct ifaddr_container *ifac;
459 	struct in_ifaddr_container *iac;
460 	struct sockaddr_in oldaddr;
461 	int hostIsNew, iaIsNew, maskIsNew, ifpWasUp;
462 	int error = 0;
463 
464 	iaIsNew = 0;
465 	ifpWasUp = 0;
466 
467 	/*
468 	 * Find address for this interface, if it exists.
469 	 *
470 	 * If an alias address was specified, find that one instead of
471 	 * the first one on the interface, if possible
472 	 */
473 	if (ifp) {
474 		struct in_ifaddr *iap;
475 
476 		dst = ((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr;
477 		LIST_FOREACH(iac, INADDR_HASH(dst.s_addr), ia_hash) {
478 			iap = iac->ia;
479 			if (iap->ia_ifp == ifp &&
480 			    iap->ia_addr.sin_addr.s_addr == dst.s_addr) {
481 				ia = iap;
482 				break;
483 			}
484 		}
485 		if (ia == NULL) {
486 			TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid],
487 				      ifa_link) {
488 				iap = ifatoia(ifac->ifa);
489 				if (iap->ia_addr.sin_family == AF_INET) {
490 					ia = iap;
491 					break;
492 				}
493 			}
494 		}
495 
496 		if (ifp->if_flags & IFF_UP)
497 			ifpWasUp = 1;
498 	}
499 
500 	switch (cmd) {
501 	case SIOCAIFADDR:
502 	case SIOCDIFADDR:
503 		if (ifp == NULL)
504 			return (EADDRNOTAVAIL);
505 		if (ifra->ifra_addr.sin_family == AF_INET) {
506 			while (ia != NULL) {
507 				if (ia->ia_ifp == ifp  &&
508 				    ia->ia_addr.sin_addr.s_addr ==
509 				    ifra->ifra_addr.sin_addr.s_addr)
510 					break;
511 				ia = in_ianext(ia);
512 			}
513 			if ((ifp->if_flags & IFF_POINTOPOINT) &&
514 			    cmd == SIOCAIFADDR &&
515 			    ifra->ifra_dstaddr.sin_addr.s_addr == INADDR_ANY) {
516 				return EDESTADDRREQ;
517 			}
518 		}
519 		if (cmd == SIOCDIFADDR && ia == NULL)
520 			return (EADDRNOTAVAIL);
521 		/* FALLTHROUGH */
522 	case SIOCSIFADDR:
523 	case SIOCSIFNETMASK:
524 	case SIOCSIFDSTADDR:
525 		if (td && (error = priv_check(td, PRIV_ROOT)) != 0)
526 			return error;
527 
528 		if (ifp == NULL)
529 			return (EADDRNOTAVAIL);
530 
531 		if (cmd == SIOCSIFDSTADDR &&
532 		    (ifp->if_flags & IFF_POINTOPOINT) == 0)
533 			return (EINVAL);
534 
535 		if (ia == NULL) {
536 			struct ifaddr *ifa;
537 			int i;
538 
539 			ia = ifa_create(sizeof(*ia), M_WAITOK);
540 			ifa = &ia->ia_ifa;
541 
542 			/*
543 			 * Setup per-CPU information
544 			 */
545 			for (i = 0; i < ncpus; ++i) {
546 				ifac = &ifa->ifa_containers[i];
547 				iac = &ifac->ifa_proto_u.u_in_ifac;
548 				iac->ia = ia;
549 				iac->ia_ifac = ifac;
550 			}
551 
552 			/*
553 			 * Protect from NETISR_IP traversing address list
554 			 * while we're modifying it.
555 			 */
556 			crit_enter();
557 
558 			in_ialink(ia);
559 			ifa_iflink(ifa, ifp, 1);
560 
561 			ifa->ifa_addr = (struct sockaddr *)&ia->ia_addr;
562 			ifa->ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr;
563 			ifa->ifa_netmask = (struct sockaddr *)&ia->ia_sockmask;
564 			ia->ia_sockmask.sin_len = 8;
565 			ia->ia_sockmask.sin_family = AF_INET;
566 			if (ifp->if_flags & IFF_BROADCAST) {
567 				ia->ia_broadaddr.sin_len = sizeof ia->ia_addr;
568 				ia->ia_broadaddr.sin_family = AF_INET;
569 			}
570 			ia->ia_ifp = ifp;
571 			if (!(ifp->if_flags & IFF_LOOPBACK))
572 				in_interfaces++;
573 			iaIsNew = 1;
574 
575 			crit_exit();
576 		}
577 		break;
578 
579 	case SIOCSIFBRDADDR:
580 		if (td && (error = priv_check(td, PRIV_ROOT)) != 0)
581 			return error;
582 		/* FALLTHROUGH */
583 
584 	case SIOCGIFADDR:
585 	case SIOCGIFNETMASK:
586 	case SIOCGIFDSTADDR:
587 	case SIOCGIFBRDADDR:
588 		if (ia == NULL)
589 			return (EADDRNOTAVAIL);
590 		break;
591 	}
592 
593 	switch (cmd) {
594 	case SIOCGIFADDR:
595 		*((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr;
596 		return (0);
597 
598 	case SIOCGIFBRDADDR:
599 		if ((ifp->if_flags & IFF_BROADCAST) == 0)
600 			return (EINVAL);
601 		*((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr;
602 		return (0);
603 
604 	case SIOCGIFDSTADDR:
605 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
606 			return (EINVAL);
607 		*((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr;
608 		return (0);
609 
610 	case SIOCGIFNETMASK:
611 		*((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask;
612 		return (0);
613 
614 	case SIOCSIFDSTADDR:
615 		KKASSERT(ifp->if_flags & IFF_POINTOPOINT);
616 
617 		oldaddr = ia->ia_dstaddr;
618 		ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr;
619 		if (ifp->if_ioctl != NULL) {
620 			ifnet_serialize_all(ifp);
621 			error = ifp->if_ioctl(ifp, SIOCSIFDSTADDR, (caddr_t)ia,
622 					      td->td_proc->p_ucred);
623 			ifnet_deserialize_all(ifp);
624 			if (error) {
625 				ia->ia_dstaddr = oldaddr;
626 				return (error);
627 			}
628 		}
629 		if (ia->ia_flags & IFA_ROUTE) {
630 			ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr;
631 			rtinit(&ia->ia_ifa, RTM_DELETE, RTF_HOST);
632 			ia->ia_ifa.ifa_dstaddr =
633 					(struct sockaddr *)&ia->ia_dstaddr;
634 			rtinit(&ia->ia_ifa, RTM_ADD, RTF_HOST | RTF_UP);
635 		}
636 		return (0);
637 
638 	case SIOCSIFBRDADDR:
639 		if ((ifp->if_flags & IFF_BROADCAST) == 0)
640 			return (EINVAL);
641 		ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr;
642 		return (0);
643 
644 	case SIOCSIFADDR:
645 		error = in_ifinit(ifp, ia,
646 		    (const struct sockaddr_in *)&ifr->ifr_addr, 1);
647 		if (error != 0 && iaIsNew)
648 			break;
649 		if (error == 0) {
650 			EVENTHANDLER_INVOKE(ifaddr_event, ifp,
651 			iaIsNew ? IFADDR_EVENT_ADD : IFADDR_EVENT_CHANGE,
652 			&ia->ia_ifa);
653 		}
654 		if (!ifpWasUp && (ifp->if_flags & IFF_UP)) {
655 			/*
656 			 * Interface is brought up by in_ifinit()
657 			 * (via ifp->if_ioctl).  We act as if the
658 			 * interface got IFF_UP flag turned on.
659 			 */
660 			if_up(ifp);
661 		}
662 		return (0);
663 
664 	case SIOCSIFNETMASK:
665 		ia->ia_sockmask.sin_addr = ifra->ifra_addr.sin_addr;
666 		ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr);
667 		return (0);
668 
669 	case SIOCAIFADDR:
670 		maskIsNew = 0;
671 		hostIsNew = 1;
672 		error = 0;
673 		if (ia->ia_addr.sin_family == AF_INET) {
674 			if (ifra->ifra_addr.sin_len == 0) {
675 				ifra->ifra_addr = ia->ia_addr;
676 				hostIsNew = 0;
677 			} else if (ifra->ifra_addr.sin_addr.s_addr ==
678 				   ia->ia_addr.sin_addr.s_addr) {
679 				hostIsNew = 0;
680 			}
681 		}
682 		if (ifra->ifra_mask.sin_len) {
683 			in_ifscrub(ifp, ia);
684 			ia->ia_sockmask = ifra->ifra_mask;
685 			ia->ia_sockmask.sin_family = AF_INET;
686 			ia->ia_subnetmask =
687 			    ntohl(ia->ia_sockmask.sin_addr.s_addr);
688 			maskIsNew = 1;
689 		}
690 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
691 		    ifra->ifra_dstaddr.sin_family == AF_INET) {
692 			in_ifscrub(ifp, ia);
693 			ia->ia_dstaddr = ifra->ifra_dstaddr;
694 			maskIsNew  = 1; /* We lie; but the effect's the same */
695 		}
696 		if (ifra->ifra_addr.sin_family == AF_INET &&
697 		    (hostIsNew || maskIsNew))
698 			error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
699 
700 		if (error != 0 && iaIsNew)
701 			break;
702 
703 		if ((ifp->if_flags & IFF_BROADCAST) &&
704 		    ifra->ifra_broadaddr.sin_family == AF_INET)
705 			ia->ia_broadaddr = ifra->ifra_broadaddr;
706 		if (error == 0) {
707 			EVENTHANDLER_INVOKE(ifaddr_event, ifp,
708 			iaIsNew ? IFADDR_EVENT_ADD : IFADDR_EVENT_CHANGE,
709 			&ia->ia_ifa);
710 		}
711 		if (!ifpWasUp && (ifp->if_flags & IFF_UP)) {
712 			/* See the comment in SIOCSIFADDR */
713 			if_up(ifp);
714 		}
715 		return (error);
716 
717 	case SIOCDIFADDR:
718 		/*
719 		 * in_ifscrub kills the interface route.
720 		 */
721 		in_ifscrub(ifp, ia);
722 		/*
723 		 * in_ifadown gets rid of all the rest of
724 		 * the routes.  This is not quite the right
725 		 * thing to do, but at least if we are running
726 		 * a routing process they will come back.
727 		 */
728 		in_ifadown(&ia->ia_ifa, 1);
729 		EVENTHANDLER_INVOKE(ifaddr_event, ifp, IFADDR_EVENT_DELETE,
730 				    &ia->ia_ifa);
731 		error = 0;
732 		break;
733 
734 	default:
735 		if (ifp == NULL || ifp->if_ioctl == NULL)
736 			return (EOPNOTSUPP);
737 		ifnet_serialize_all(ifp);
738 		error = ifp->if_ioctl(ifp, cmd, data, td->td_proc->p_ucred);
739 		ifnet_deserialize_all(ifp);
740 		return (error);
741 	}
742 
743 	KKASSERT(cmd == SIOCDIFADDR ||
744 		 ((cmd == SIOCAIFADDR || cmd == SIOCSIFADDR) && iaIsNew));
745 
746 	ifa_ifunlink(&ia->ia_ifa, ifp);
747 	in_iaunlink(ia);
748 
749 	if (cmd == SIOCDIFADDR) {
750 		ifac = &ia->ia_ifa.ifa_containers[mycpuid];
751 		if (ifac->ifa_listmask & IFA_LIST_IN_IFADDRHASH)
752 			in_iahash_remove(ia);
753 	}
754 #ifdef INVARIANTS
755 	else {
756 		/*
757 		 * If cmd is SIOCSIFADDR or SIOCAIFADDR, in_ifinit() has
758 		 * already taken care of the deletion from hash table
759 		 */
760 		ifac = &ia->ia_ifa.ifa_containers[mycpuid];
761 		KASSERT((ifac->ifa_listmask & IFA_LIST_IN_IFADDRHASH) == 0,
762 			("SIOC%cIFADDR failed on new ia, "
763 			 "but the new ia is still in hash table",
764 			 cmd == SIOCSIFADDR ? 'S' : 'A'));
765 	}
766 #endif
767 
768 	ifa_destroy(&ia->ia_ifa);
769 
770 	if ((cmd == SIOCAIFADDR || cmd == SIOCSIFADDR) &&
771 	    !ifpWasUp && (ifp->if_flags & IFF_UP)) {
772 		/*
773 		 * Though the address assignment failed, the
774 		 * interface is brought up by in_ifinit()
775 		 * (via ifp->if_ioctl).  With the hope that
776 		 * the interface has some valid addresses, we
777 		 * act as if IFF_UP flag was just set on the
778 		 * interface.
779 		 *
780 		 * NOTE:
781 		 * This could only be done after the failed
782 		 * address is unlinked from the global address
783 		 * list.
784 		 */
785 		if_up(ifp);
786 	}
787 
788 	return (error);
789 }
790 
791 /*
792  * SIOC[GAD]LIFADDR.
793  *	SIOCGLIFADDR: get first address. (?!?)
794  *	SIOCGLIFADDR with IFLR_PREFIX:
795  *		get first address that matches the specified prefix.
796  *	SIOCALIFADDR: add the specified address.
797  *	SIOCALIFADDR with IFLR_PREFIX:
798  *		EINVAL since we can't deduce hostid part of the address.
799  *	SIOCDLIFADDR: delete the specified address.
800  *	SIOCDLIFADDR with IFLR_PREFIX:
801  *		delete the first address that matches the specified prefix.
802  * return values:
803  *	EINVAL on invalid parameters
804  *	EADDRNOTAVAIL on prefix match failed/specified address not found
805  *	other values may be returned from in_ioctl()
806  *
807  * NOTE! td might be NULL.
808  */
809 static int
810 in_lifaddr_ioctl(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
811 		 struct thread *td)
812 {
813 	struct if_laddrreq *iflr = (struct if_laddrreq *)data;
814 
815 	/* sanity checks */
816 	if (!data || !ifp) {
817 		panic("invalid argument to in_lifaddr_ioctl");
818 		/*NOTRECHED*/
819 	}
820 
821 	switch (cmd) {
822 	case SIOCGLIFADDR:
823 		/* address must be specified on GET with IFLR_PREFIX */
824 		if ((iflr->flags & IFLR_PREFIX) == 0)
825 			break;
826 		/*FALLTHROUGH*/
827 	case SIOCALIFADDR:
828 	case SIOCDLIFADDR:
829 		/* address must be specified on ADD and DELETE */
830 		if (iflr->addr.ss_family != AF_INET)
831 			return EINVAL;
832 		if (iflr->addr.ss_len != sizeof(struct sockaddr_in))
833 			return EINVAL;
834 		/* XXX need improvement */
835 		if (iflr->dstaddr.ss_family
836 		 && iflr->dstaddr.ss_family != AF_INET)
837 			return EINVAL;
838 		if (iflr->dstaddr.ss_family
839 		 && iflr->dstaddr.ss_len != sizeof(struct sockaddr_in))
840 			return EINVAL;
841 		break;
842 	default: /*shouldn't happen*/
843 		return EOPNOTSUPP;
844 	}
845 	if (sizeof(struct in_addr) * 8 < iflr->prefixlen)
846 		return EINVAL;
847 
848 	switch (cmd) {
849 	case SIOCALIFADDR:
850 	    {
851 		struct in_aliasreq ifra;
852 
853 		if (iflr->flags & IFLR_PREFIX)
854 			return EINVAL;
855 
856 		/* copy args to in_aliasreq, perform ioctl(SIOCAIFADDR_IN6). */
857 		bzero(&ifra, sizeof ifra);
858 		bcopy(iflr->iflr_name, ifra.ifra_name, sizeof ifra.ifra_name);
859 
860 		bcopy(&iflr->addr, &ifra.ifra_addr, iflr->addr.ss_len);
861 
862 		if (iflr->dstaddr.ss_family) {	/*XXX*/
863 			bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
864 				iflr->dstaddr.ss_len);
865 		}
866 
867 		ifra.ifra_mask.sin_family = AF_INET;
868 		ifra.ifra_mask.sin_len = sizeof(struct sockaddr_in);
869 		in_len2mask(&ifra.ifra_mask.sin_addr, iflr->prefixlen);
870 
871 		return in_control(so, SIOCAIFADDR, (caddr_t)&ifra, ifp, td);
872 	    }
873 	case SIOCGLIFADDR:
874 	case SIOCDLIFADDR:
875 	    {
876 		struct ifaddr_container *ifac;
877 		struct in_ifaddr *ia;
878 		struct in_addr mask, candidate, match;
879 		struct sockaddr_in *sin;
880 		int cmp;
881 
882 		bzero(&mask, sizeof mask);
883 		if (iflr->flags & IFLR_PREFIX) {
884 			/* lookup a prefix rather than address. */
885 			in_len2mask(&mask, iflr->prefixlen);
886 
887 			sin = (struct sockaddr_in *)&iflr->addr;
888 			match.s_addr = sin->sin_addr.s_addr;
889 			match.s_addr &= mask.s_addr;
890 
891 			/* if you set extra bits, that's wrong */
892 			if (match.s_addr != sin->sin_addr.s_addr)
893 				return EINVAL;
894 
895 			cmp = 1;
896 		} else {
897 			if (cmd == SIOCGLIFADDR) {
898 				/* on getting an address, take the 1st match */
899 				match.s_addr = 0; /* gcc4 warning */
900 				cmp = 0;	/*XXX*/
901 			} else {
902 				/* on deleting an address, do exact match */
903 				in_len2mask(&mask, 32);
904 				sin = (struct sockaddr_in *)&iflr->addr;
905 				match.s_addr = sin->sin_addr.s_addr;
906 
907 				cmp = 1;
908 			}
909 		}
910 
911 		TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
912 			struct ifaddr *ifa = ifac->ifa;
913 
914 			if (ifa->ifa_addr->sa_family != AF_INET6)
915 				continue;
916 			if (!cmp)
917 				break;
918 			candidate.s_addr =
919 			((struct sockaddr_in *)&ifa->ifa_addr)->sin_addr.s_addr;
920 			candidate.s_addr &= mask.s_addr;
921 			if (candidate.s_addr == match.s_addr)
922 				break;
923 		}
924 		if (ifac == NULL)
925 			return EADDRNOTAVAIL;
926 		ia = (struct in_ifaddr *)(ifac->ifa);
927 
928 		if (cmd == SIOCGLIFADDR) {
929 			/* fill in the if_laddrreq structure */
930 			bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin_len);
931 
932 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
933 				bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
934 					ia->ia_dstaddr.sin_len);
935 			} else
936 				bzero(&iflr->dstaddr, sizeof iflr->dstaddr);
937 
938 			iflr->prefixlen =
939 				in_mask2len(&ia->ia_sockmask.sin_addr);
940 
941 			iflr->flags = 0;	/*XXX*/
942 
943 			return 0;
944 		} else {
945 			struct in_aliasreq ifra;
946 
947 			/* fill in_aliasreq and do ioctl(SIOCDIFADDR_IN6) */
948 			bzero(&ifra, sizeof ifra);
949 			bcopy(iflr->iflr_name, ifra.ifra_name,
950 				sizeof ifra.ifra_name);
951 
952 			bcopy(&ia->ia_addr, &ifra.ifra_addr,
953 				ia->ia_addr.sin_len);
954 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
955 				bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
956 					ia->ia_dstaddr.sin_len);
957 			}
958 			bcopy(&ia->ia_sockmask, &ifra.ifra_dstaddr,
959 				ia->ia_sockmask.sin_len);
960 
961 			return in_control(so, SIOCDIFADDR, (caddr_t)&ifra,
962 					  ifp, td);
963 		}
964 	    }
965 	}
966 
967 	return EOPNOTSUPP;	/*just for safety*/
968 }
969 
970 /*
971  * Delete any existing route for an interface.
972  */
973 void
974 in_ifscrub(struct ifnet *ifp __unused, struct in_ifaddr *ia)
975 {
976 	in_scrubprefix(ia);
977 }
978 
979 /*
980  * Initialize an interface's internet address
981  * and routing table entry.
982  */
983 static int
984 in_ifinit(struct ifnet *ifp, struct in_ifaddr *ia,
985 	  const struct sockaddr_in *sin, int scrub)
986 {
987 	u_long i = ntohl(sin->sin_addr.s_addr);
988 	struct sockaddr_in oldaddr;
989 	struct ifaddr_container *ifac;
990 	int flags = RTF_UP, error = 0;
991 	int was_hash = 0;
992 
993 	ifac = &ia->ia_ifa.ifa_containers[mycpuid];
994 	oldaddr = ia->ia_addr;
995 
996 	if (ifac->ifa_listmask & IFA_LIST_IN_IFADDRHASH) {
997 		was_hash = 1;
998 		in_iahash_remove(ia);
999 	}
1000 
1001 	ia->ia_addr = *sin;
1002 	if (ia->ia_addr.sin_family == AF_INET)
1003 		in_iahash_insert(ia);
1004 
1005 	/*
1006 	 * Give the interface a chance to initialize
1007 	 * if this is its first address,
1008 	 * and to validate the address if necessary.
1009 	 */
1010 	if (ifp->if_ioctl != NULL) {
1011 		ifnet_serialize_all(ifp);
1012 		error = ifp->if_ioctl(ifp, SIOCSIFADDR, (caddr_t)ia, NULL);
1013 		ifnet_deserialize_all(ifp);
1014 		if (error)
1015 			goto fail;
1016 	}
1017 
1018 	/*
1019 	 * Delete old route, if requested.
1020 	 */
1021 	if (scrub) {
1022 		ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr;
1023 		in_ifscrub(ifp, ia);
1024 		ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
1025 	}
1026 
1027 	/*
1028 	 * Calculate netmask/subnetmask.
1029 	 */
1030 	if (IN_CLASSA(i))
1031 		ia->ia_netmask = IN_CLASSA_NET;
1032 	else if (IN_CLASSB(i))
1033 		ia->ia_netmask = IN_CLASSB_NET;
1034 	else
1035 		ia->ia_netmask = IN_CLASSC_NET;
1036 	/*
1037 	 * The subnet mask usually includes at least the standard network part,
1038 	 * but may may be smaller in the case of supernetting.
1039 	 * If it is set, we believe it.
1040 	 */
1041 	if (ia->ia_subnetmask == 0) {
1042 		ia->ia_subnetmask = ia->ia_netmask;
1043 		ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
1044 	} else {
1045 		ia->ia_netmask &= ia->ia_subnetmask;
1046 	}
1047 	ia->ia_net = i & ia->ia_netmask;
1048 	ia->ia_subnet = i & ia->ia_subnetmask;
1049 	in_socktrim(&ia->ia_sockmask);
1050 
1051 	/*
1052 	 * Add route for the network.
1053 	 */
1054 	ia->ia_ifa.ifa_metric = ifp->if_metric;
1055 	if (ifp->if_flags & IFF_BROADCAST) {
1056 		ia->ia_broadaddr.sin_addr.s_addr =
1057 			htonl(ia->ia_subnet | ~ia->ia_subnetmask);
1058 		ia->ia_netbroadcast.s_addr =
1059 			htonl(ia->ia_net | ~ ia->ia_netmask);
1060 	} else if (ifp->if_flags & IFF_LOOPBACK) {
1061 		ia->ia_dstaddr = ia->ia_addr;
1062 		flags |= RTF_HOST;
1063 	} else if (ifp->if_flags & IFF_POINTOPOINT) {
1064 		if (ia->ia_dstaddr.sin_family != AF_INET)
1065 			return (0);
1066 		flags |= RTF_HOST;
1067 	}
1068 
1069 	/*-
1070 	 * Don't add host routes for interface addresses of
1071 	 * 0.0.0.0 --> 0.255.255.255 netmask 255.0.0.0.  This makes it
1072 	 * possible to assign several such address pairs with consistent
1073 	 * results (no host route) and is required by BOOTP.
1074 	 *
1075 	 * XXX: This is ugly !  There should be a way for the caller to
1076 	 *      say that they don't want a host route.
1077 	 */
1078 	if (ia->ia_addr.sin_addr.s_addr != INADDR_ANY ||
1079 	    ia->ia_netmask != IN_CLASSA_NET ||
1080 	    ia->ia_dstaddr.sin_addr.s_addr != htonl(IN_CLASSA_HOST)) {
1081 		error = in_addprefix(ia, flags);
1082 		if (error)
1083 			goto fail;
1084 	}
1085 
1086 	/*
1087 	 * If the interface supports multicast, join the "all hosts"
1088 	 * multicast group on that interface.
1089 	 */
1090 	if (ifp->if_flags & IFF_MULTICAST) {
1091 		struct in_addr addr;
1092 
1093 		addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
1094 		in_addmulti(&addr, ifp);
1095 	}
1096 	return (0);
1097 fail:
1098 	if (ifac->ifa_listmask & IFA_LIST_IN_IFADDRHASH)
1099 		in_iahash_remove(ia);
1100 
1101 	ia->ia_addr = oldaddr;
1102 	if (was_hash)
1103 		in_iahash_insert(ia);
1104 	return (error);
1105 }
1106 
1107 #define rtinitflags(x) \
1108 	(((x)->ia_ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) \
1109 	 ? RTF_HOST : 0)
1110 
1111 /*
1112  * Add a route to prefix ("connected route" in cisco terminology).
1113  * Do nothing, if there are some interface addresses with the same
1114  * prefix already.  This function assumes that the 'target' parent
1115  * interface is UP.
1116  */
1117 static int
1118 in_addprefix(struct in_ifaddr *target, int flags)
1119 {
1120 	struct in_ifaddr_container *iac;
1121 	struct in_addr prefix, mask;
1122 	int error;
1123 
1124 #ifdef CARP
1125 	/*
1126 	 * Don't add prefix routes for CARP interfaces.
1127 	 * Prefix routes creation is handled by CARP
1128 	 * interfaces themselves.
1129 	 */
1130 	if (target->ia_ifp->if_type == IFT_CARP)
1131 		return 0;
1132 #endif
1133 
1134 	mask = target->ia_sockmask.sin_addr;
1135 	if (flags & RTF_HOST) {
1136 		prefix = target->ia_dstaddr.sin_addr;
1137 	} else {
1138 		prefix = target->ia_addr.sin_addr;
1139 		prefix.s_addr &= mask.s_addr;
1140 	}
1141 
1142 	TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) {
1143 		struct in_ifaddr *ia = iac->ia;
1144 		struct in_addr p;
1145 
1146 		/* Don't test against self */
1147 		if (ia == target)
1148 			continue;
1149 
1150 		/* The tested address does not own a route entry */
1151 		if ((ia->ia_flags & IFA_ROUTE) == 0)
1152 			continue;
1153 
1154 		/* Prefix test */
1155 		if (rtinitflags(ia)) {
1156 			p = ia->ia_dstaddr.sin_addr;
1157 		} else {
1158 			p = ia->ia_addr.sin_addr;
1159 			p.s_addr &= ia->ia_sockmask.sin_addr.s_addr;
1160 		}
1161 		if (prefix.s_addr != p.s_addr)
1162 			continue;
1163 
1164 		/*
1165 		 * If the to-be-added address and the curretly being
1166 		 * tested address are not host addresses, we need to
1167 		 * take subnetmask into consideration.
1168 		 */
1169 		if (!(flags & RTF_HOST) && !rtinitflags(ia) &&
1170 		    mask.s_addr != ia->ia_sockmask.sin_addr.s_addr)
1171 			continue;
1172 
1173 		/*
1174 		 * If we got a matching prefix route inserted by other
1175 		 * interface address, we don't need to bother.
1176 		 */
1177 		return 0;
1178 	}
1179 
1180 	/*
1181 	 * No one seem to have prefix route; insert it.
1182 	 */
1183 	error = rtinit(&target->ia_ifa, RTM_ADD, flags);
1184 	if (!error)
1185 		target->ia_flags |= IFA_ROUTE;
1186 	return error;
1187 }
1188 
1189 /*
1190  * Remove a route to prefix ("connected route" in cisco terminology).
1191  * Re-installs the route by using another interface address, if there's
1192  * one with the same prefix (otherwise we lose the route mistakenly).
1193  */
1194 static void
1195 in_scrubprefix(struct in_ifaddr *target)
1196 {
1197 	struct in_ifaddr_container *iac;
1198 	struct in_addr prefix, mask;
1199 	int error;
1200 
1201 #ifdef CARP
1202 	/*
1203 	 * Don't scrub prefix routes for CARP interfaces.
1204 	 * Prefix routes deletion is handled by CARP
1205 	 * interfaces themselves.
1206 	 */
1207 	if (target->ia_ifp->if_type == IFT_CARP)
1208 		return;
1209 #endif
1210 
1211 	if ((target->ia_flags & IFA_ROUTE) == 0)
1212 		return;
1213 
1214 	mask = target->ia_sockmask.sin_addr;
1215 	if (rtinitflags(target)) {
1216 		prefix = target->ia_dstaddr.sin_addr;
1217 	} else {
1218 		prefix = target->ia_addr.sin_addr;
1219 		prefix.s_addr &= mask.s_addr;
1220 	}
1221 
1222 	TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) {
1223 		struct in_ifaddr *ia = iac->ia;
1224 		struct in_addr p;
1225 
1226 		/* Don't test against self */
1227 		if (ia == target)
1228 			continue;
1229 
1230 		/* The tested address already owns a route entry */
1231 		if (ia->ia_flags & IFA_ROUTE)
1232 			continue;
1233 
1234 		/*
1235 		 * The prefix route of the tested address should
1236 		 * never be installed if its parent interface is
1237 		 * not UP yet.
1238 		 */
1239 		if ((ia->ia_ifp->if_flags & IFF_UP) == 0)
1240 			continue;
1241 
1242 #ifdef CARP
1243 		/*
1244 		 * Don't add prefix routes for CARP interfaces.
1245 		 * Prefix routes creation is handled by CARP
1246 		 * interfaces themselves.
1247 		 */
1248 		if (ia->ia_ifp->if_type == IFT_CARP)
1249 			continue;
1250 #endif
1251 
1252 		/* Prefix test */
1253 		if (rtinitflags(ia)) {
1254 			p = ia->ia_dstaddr.sin_addr;
1255 		} else {
1256 			p = ia->ia_addr.sin_addr;
1257 			p.s_addr &= ia->ia_sockmask.sin_addr.s_addr;
1258 		}
1259 		if (prefix.s_addr != p.s_addr)
1260 			continue;
1261 
1262 		/*
1263 		 * We don't need to test subnetmask here, as what we do
1264 		 * in in_addprefix(), since if the the tested address's
1265 		 * parent interface is UP, the tested address should own
1266 		 * a prefix route entry and we would never reach here.
1267 		 */
1268 
1269 		/*
1270 		 * If we got a matching prefix route, move IFA_ROUTE to him
1271 		 */
1272 		rtinit(&target->ia_ifa, RTM_DELETE, rtinitflags(target));
1273 		target->ia_flags &= ~IFA_ROUTE;
1274 
1275 		error = rtinit(&ia->ia_ifa, RTM_ADD, rtinitflags(ia) | RTF_UP);
1276 		if (!error)
1277 			ia->ia_flags |= IFA_ROUTE;
1278 		return;
1279 	}
1280 
1281 	/*
1282 	 * No candidates for this prefix route; just remove it.
1283 	 */
1284 	rtinit(&target->ia_ifa, RTM_DELETE, rtinitflags(target));
1285 	target->ia_flags &= ~IFA_ROUTE;
1286 }
1287 
1288 #undef rtinitflags
1289 
1290 /*
1291  * Return 1 if the address might be a local broadcast address.
1292  */
1293 int
1294 in_broadcast(struct in_addr in, struct ifnet *ifp)
1295 {
1296 	struct ifaddr_container *ifac;
1297 	u_long t;
1298 
1299 	if (in.s_addr == INADDR_BROADCAST ||
1300 	    in.s_addr == INADDR_ANY)
1301 		return 1;
1302 	if ((ifp->if_flags & IFF_BROADCAST) == 0)
1303 		return 0;
1304 	t = ntohl(in.s_addr);
1305 	/*
1306 	 * Look through the list of addresses for a match
1307 	 * with a broadcast address.
1308 	 */
1309 #define ia ((struct in_ifaddr *)ifa)
1310 	TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
1311 		struct ifaddr *ifa = ifac->ifa;
1312 
1313 		if (ifa->ifa_addr->sa_family == AF_INET &&
1314 		    (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
1315 		     in.s_addr == ia->ia_netbroadcast.s_addr ||
1316 		     /*
1317 		      * Check for old-style (host 0) broadcast.
1318 		      */
1319 		     t == ia->ia_subnet || t == ia->ia_net) &&
1320 		     /*
1321 		      * Check for an all one subnetmask. These
1322 		      * only exist when an interface gets a secondary
1323 		      * address.
1324 		      */
1325 		     ia->ia_subnetmask != (u_long)0xffffffff)
1326 			    return 1;
1327 	}
1328 	return (0);
1329 #undef ia
1330 }
1331 /*
1332  * Add an address to the list of IP multicast addresses for a given interface.
1333  */
1334 struct in_multi *
1335 in_addmulti(struct in_addr *ap, struct ifnet *ifp)
1336 {
1337 	struct in_multi *inm;
1338 	int error;
1339 	struct sockaddr_in sin;
1340 	struct ifmultiaddr *ifma;
1341 
1342 	/*
1343 	 * Call generic routine to add membership or increment
1344 	 * refcount.  It wants addresses in the form of a sockaddr,
1345 	 * so we build one here (being careful to zero the unused bytes).
1346 	 */
1347 	bzero(&sin, sizeof sin);
1348 	sin.sin_family = AF_INET;
1349 	sin.sin_len = sizeof sin;
1350 	sin.sin_addr = *ap;
1351 	crit_enter();
1352 	error = if_addmulti(ifp, (struct sockaddr *)&sin, &ifma);
1353 	if (error) {
1354 		crit_exit();
1355 		return 0;
1356 	}
1357 
1358 	/*
1359 	 * If ifma->ifma_protospec is null, then if_addmulti() created
1360 	 * a new record.  Otherwise, we are done.
1361 	 */
1362 	if (ifma->ifma_protospec != 0) {
1363 		crit_exit();
1364 		return ifma->ifma_protospec;
1365 	}
1366 
1367 	/* XXX - if_addmulti uses M_WAITOK.  Can this really be called
1368 	   at interrupt time?  If so, need to fix if_addmulti. XXX */
1369 	inm = kmalloc(sizeof *inm, M_IPMADDR, M_WAITOK | M_ZERO);
1370 	inm->inm_addr = *ap;
1371 	inm->inm_ifp = ifp;
1372 	inm->inm_ifma = ifma;
1373 	ifma->ifma_protospec = inm;
1374 	LIST_INSERT_HEAD(&in_multihead, inm, inm_link);
1375 
1376 	/*
1377 	 * Let IGMP know that we have joined a new IP multicast group.
1378 	 */
1379 	igmp_joingroup(inm);
1380 	crit_exit();
1381 	return (inm);
1382 }
1383 
1384 /*
1385  * Delete a multicast address record.
1386  */
1387 void
1388 in_delmulti(struct in_multi *inm)
1389 {
1390 	struct ifmultiaddr *ifma;
1391 	struct in_multi my_inm;
1392 
1393 	crit_enter();
1394 	ifma = inm->inm_ifma;
1395 	my_inm.inm_ifp = NULL ; /* don't send the leave msg */
1396 	if (ifma->ifma_refcount == 1) {
1397 		/*
1398 		 * No remaining claims to this record; let IGMP know that
1399 		 * we are leaving the multicast group.
1400 		 * But do it after the if_delmulti() which might reset
1401 		 * the interface and nuke the packet.
1402 		 */
1403 		my_inm = *inm ;
1404 		ifma->ifma_protospec = 0;
1405 		LIST_REMOVE(inm, inm_link);
1406 		kfree(inm, M_IPMADDR);
1407 	}
1408 	/* XXX - should be separate API for when we have an ifma? */
1409 	if_delmulti(ifma->ifma_ifp, ifma->ifma_addr);
1410 	if (my_inm.inm_ifp != NULL)
1411 		igmp_leavegroup(&my_inm);
1412 	crit_exit();
1413 }
1414 
1415 void
1416 in_ifdetach(struct ifnet *ifp)
1417 {
1418 	in_pcbpurgeif0(LIST_FIRST(&ripcbinfo.pcblisthead), ifp);
1419 
1420 	udbinfo_lock();
1421 	in_pcbpurgeif0(LIST_FIRST(&udbinfo.pcblisthead), ifp);
1422 	udbinfo_unlock();
1423 }
1424