xref: /dragonfly/sys/netinet/in.c (revision 678e8cc6)
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. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	@(#)in.c	8.4 (Berkeley) 1/9/95
34  * $FreeBSD: src/sys/netinet/in.c,v 1.44.2.14 2002/11/08 00:45:50 suz Exp $
35  * $DragonFly: src/sys/netinet/in.c,v 1.41 2008/08/17 05:20:10 sephe Exp $
36  */
37 
38 #include "opt_bootp.h"
39 #include "opt_carp.h"
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/sockio.h>
44 #include <sys/malloc.h>
45 #include <sys/proc.h>
46 #include <sys/priv.h>
47 #include <sys/msgport.h>
48 #include <sys/socket.h>
49 
50 #include <sys/kernel.h>
51 #include <sys/sysctl.h>
52 #include <sys/thread2.h>
53 
54 #include <net/if.h>
55 #include <net/if_types.h>
56 #include <net/route.h>
57 #include <net/netmsg2.h>
58 
59 #include <netinet/in.h>
60 #include <netinet/in_var.h>
61 #include <netinet/in_pcb.h>
62 #include <netinet/udp_var.h>
63 
64 #include <netinet/igmp_var.h>
65 
66 MALLOC_DEFINE(M_IPMADDR, "in_multi", "internet multicast address");
67 
68 static int in_mask2len (struct in_addr *);
69 static void in_len2mask (struct in_addr *, int);
70 static int in_lifaddr_ioctl (struct socket *, u_long, caddr_t,
71 	struct ifnet *, struct thread *);
72 
73 static void	in_socktrim (struct sockaddr_in *);
74 static int	in_ifinit(struct ifnet *, struct in_ifaddr *,
75 		    const struct sockaddr_in *, int);
76 
77 static int	in_control_internal(u_long, caddr_t, struct ifnet *,
78 		    struct thread *);
79 static int	in_control_redispatch(u_long, caddr_t, struct ifnet *,
80 		    struct thread *);
81 
82 static int	in_addprefix(struct in_ifaddr *, int);
83 static void	in_scrubprefix(struct in_ifaddr *);
84 
85 static int subnetsarelocal = 0;
86 SYSCTL_INT(_net_inet_ip, OID_AUTO, subnets_are_local, CTLFLAG_RW,
87     &subnetsarelocal, 0,
88     "Count all internet addresses of subnets of the local net as local");
89 
90 struct in_multihead in_multihead; /* XXX BSS initialization */
91 
92 extern struct inpcbinfo ripcbinfo;
93 
94 /*
95  * Return 1 if an internet address is for a ``local'' host
96  * (one to which we have a connection).  If subnetsarelocal
97  * is true, this includes other subnets of the local net.
98  * Otherwise, it includes only the directly-connected (sub)nets.
99  */
100 int
101 in_localaddr(struct in_addr in)
102 {
103 	u_long i = ntohl(in.s_addr);
104 	struct in_ifaddr_container *iac;
105 	struct in_ifaddr *ia;
106 
107 	if (subnetsarelocal) {
108 		TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) {
109 			ia = iac->ia;
110 
111 			if ((i & ia->ia_netmask) == ia->ia_net)
112 				return (1);
113 		}
114 	} else {
115 		TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) {
116 			ia = iac->ia;
117 
118 			if ((i & ia->ia_subnetmask) == ia->ia_subnet)
119 				return (1);
120 		}
121 	}
122 	return (0);
123 }
124 
125 /*
126  * Determine whether an IP address is in a reserved set of addresses
127  * that may not be forwarded, or whether datagrams to that destination
128  * may be forwarded.
129  */
130 int
131 in_canforward(struct in_addr in)
132 {
133 	u_long i = ntohl(in.s_addr);
134 	u_long net;
135 
136 	if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i))
137 		return (0);
138 	if (IN_CLASSA(i)) {
139 		net = i & IN_CLASSA_NET;
140 		if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
141 			return (0);
142 	}
143 	return (1);
144 }
145 
146 /*
147  * Trim a mask in a sockaddr
148  */
149 static void
150 in_socktrim(struct sockaddr_in *ap)
151 {
152     char *cplim = (char *) &ap->sin_addr;
153     char *cp = (char *) (&ap->sin_addr + 1);
154 
155     ap->sin_len = 0;
156     while (--cp >= cplim)
157 	if (*cp) {
158 	    (ap)->sin_len = cp - (char *) (ap) + 1;
159 	    break;
160 	}
161 }
162 
163 static int
164 in_mask2len(struct in_addr *mask)
165 {
166 	int x, y;
167 	u_char *p;
168 
169 	p = (u_char *)mask;
170 	for (x = 0; x < sizeof *mask; x++) {
171 		if (p[x] != 0xff)
172 			break;
173 	}
174 	y = 0;
175 	if (x < sizeof *mask) {
176 		for (y = 0; y < 8; y++) {
177 			if ((p[x] & (0x80 >> y)) == 0)
178 				break;
179 		}
180 	}
181 	return x * 8 + y;
182 }
183 
184 static void
185 in_len2mask(struct in_addr *mask, int len)
186 {
187 	int i;
188 	u_char *p;
189 
190 	p = (u_char *)mask;
191 	bzero(mask, sizeof *mask);
192 	for (i = 0; i < len / 8; i++)
193 		p[i] = 0xff;
194 	if (len % 8)
195 		p[i] = (0xff00 >> (len % 8)) & 0xff;
196 }
197 
198 static int in_interfaces;	/* number of external internet interfaces */
199 
200 void
201 in_control_dispatch(netmsg_t msg)
202 {
203 	int error;
204 
205 	error = in_control_redispatch(msg->control.nm_cmd,
206 				      msg->control.nm_data,
207 				      msg->control.nm_ifp,
208 				      msg->control.nm_td);
209 	lwkt_replymsg(&msg->lmsg, error);
210 }
211 
212 static void
213 in_control_internal_dispatch(netmsg_t msg)
214 {
215 	int error;
216 
217 	error = in_control_internal(msg->control.nm_cmd,
218 				    msg->control.nm_data,
219 				    msg->control.nm_ifp,
220 				    msg->control.nm_td);
221 	lwkt_replymsg(&msg->lmsg, error);
222 }
223 
224 static int
225 in_control_redispatch(u_long cmd, caddr_t data, struct ifnet *ifp,
226 		      struct thread *td)
227 {
228 	struct netmsg_pru_control msg;
229 	int error;
230 
231 	/*
232 	 * IFADDR alterations are serialized by netisr0
233 	 */
234 	switch (cmd) {
235 	case SIOCSIFDSTADDR:
236 	case SIOCSIFBRDADDR:
237 	case SIOCSIFADDR:
238 	case SIOCSIFNETMASK:
239 	case SIOCAIFADDR:
240 	case SIOCDIFADDR:
241 		netmsg_init(&msg.base, NULL, &curthread->td_msgport,
242 			    0, in_control_internal_dispatch);
243 		msg.nm_cmd = cmd;
244 		msg.nm_data = data;
245 		msg.nm_ifp = ifp;
246 		msg.nm_td = td;
247 		lwkt_domsg(cpu_portfn(0), &msg.base.lmsg, 0);
248 		error = msg.base.lmsg.ms_error;
249 		break;
250 
251 	default:
252 		error = in_control_internal(cmd, data, ifp, td);
253 		break;
254 	}
255 	return error;
256 }
257 
258 /*
259  * Generic internet control operations (ioctl's).
260  * Ifp is 0 if not an interface-specific ioctl.
261  *
262  * NOTE! td might be NULL.
263  */
264 /* ARGSUSED */
265 int
266 in_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
267 	   struct thread *td)
268 {
269 	int error;
270 
271 	switch (cmd) {
272 	case SIOCALIFADDR:
273 	case SIOCDLIFADDR:
274 		if (td && (error = priv_check(td, PRIV_ROOT)) != 0)
275 			return error;
276 		/* FALLTHROUGH */
277 	case SIOCGLIFADDR:
278 		if (!ifp)
279 			return EINVAL;
280 		return in_lifaddr_ioctl(so, cmd, data, ifp, td);
281 	}
282 
283 	KASSERT(cmd != SIOCALIFADDR && cmd != SIOCDLIFADDR,
284 		("recursive SIOC%cLIFADDR!\n",
285 		 cmd == SIOCDLIFADDR ? 'D' : 'A'));
286 
287 	return in_control_redispatch(cmd, data, ifp, td);
288 }
289 
290 static void
291 in_ialink_dispatch(netmsg_t msg)
292 {
293 	struct in_ifaddr *ia = msg->lmsg.u.ms_resultp;
294 	struct ifaddr_container *ifac;
295 	struct in_ifaddr_container *iac;
296 	int cpu = mycpuid;
297 
298 	crit_enter();
299 
300 	ifac = &ia->ia_ifa.ifa_containers[cpu];
301 	ASSERT_IFAC_VALID(ifac);
302 	KASSERT((ifac->ifa_listmask & IFA_LIST_IN_IFADDRHEAD) == 0,
303 		("ia is on in_ifaddrheads\n"));
304 
305 	ifac->ifa_listmask |= IFA_LIST_IN_IFADDRHEAD;
306 	iac = &ifac->ifa_proto_u.u_in_ifac;
307 	TAILQ_INSERT_TAIL(&in_ifaddrheads[cpu], iac, ia_link);
308 
309 	crit_exit();
310 
311 	ifa_forwardmsg(&msg->lmsg, cpu + 1);
312 }
313 
314 static void
315 in_iaunlink_dispatch(netmsg_t msg)
316 {
317 	struct in_ifaddr *ia = msg->lmsg.u.ms_resultp;
318 	struct ifaddr_container *ifac;
319 	struct in_ifaddr_container *iac;
320 	int cpu = mycpuid;
321 
322 	crit_enter();
323 
324 	ifac = &ia->ia_ifa.ifa_containers[cpu];
325 	ASSERT_IFAC_VALID(ifac);
326 	KASSERT(ifac->ifa_listmask & IFA_LIST_IN_IFADDRHEAD,
327 		("ia is not on in_ifaddrheads\n"));
328 
329 	iac = &ifac->ifa_proto_u.u_in_ifac;
330 	TAILQ_REMOVE(&in_ifaddrheads[cpu], iac, ia_link);
331 	ifac->ifa_listmask &= ~IFA_LIST_IN_IFADDRHEAD;
332 
333 	crit_exit();
334 
335 	ifa_forwardmsg(&msg->lmsg, cpu + 1);
336 }
337 
338 static void
339 in_iahashins_dispatch(netmsg_t msg)
340 {
341 	struct in_ifaddr *ia = msg->lmsg.u.ms_resultp;
342 	struct ifaddr_container *ifac;
343 	struct in_ifaddr_container *iac;
344 	int cpu = mycpuid;
345 
346 	crit_enter();
347 
348 	ifac = &ia->ia_ifa.ifa_containers[cpu];
349 	ASSERT_IFAC_VALID(ifac);
350 	KASSERT((ifac->ifa_listmask & IFA_LIST_IN_IFADDRHASH) == 0,
351 		("ia is on in_ifaddrhashtbls\n"));
352 
353 	ifac->ifa_listmask |= IFA_LIST_IN_IFADDRHASH;
354 	iac = &ifac->ifa_proto_u.u_in_ifac;
355 	LIST_INSERT_HEAD(INADDR_HASH(ia->ia_addr.sin_addr.s_addr),
356 			 iac, ia_hash);
357 
358 	crit_exit();
359 
360 	ifa_forwardmsg(&msg->lmsg, cpu + 1);
361 }
362 
363 static void
364 in_iahashrem_dispatch(netmsg_t msg)
365 {
366 	struct in_ifaddr *ia = msg->lmsg.u.ms_resultp;
367 	struct ifaddr_container *ifac;
368 	struct in_ifaddr_container *iac;
369 	int cpu = mycpuid;
370 
371 	crit_enter();
372 
373 	ifac = &ia->ia_ifa.ifa_containers[cpu];
374 	ASSERT_IFAC_VALID(ifac);
375 	KASSERT(ifac->ifa_listmask & IFA_LIST_IN_IFADDRHASH,
376 		("ia is not on in_ifaddrhashtbls\n"));
377 
378 	iac = &ifac->ifa_proto_u.u_in_ifac;
379 	LIST_REMOVE(iac, ia_hash);
380 	ifac->ifa_listmask &= ~IFA_LIST_IN_IFADDRHASH;
381 
382 	crit_exit();
383 
384 	ifa_forwardmsg(&msg->lmsg, cpu + 1);
385 }
386 
387 static void
388 in_ialink(struct in_ifaddr *ia)
389 {
390 	struct netmsg_base msg;
391 
392 	netmsg_init(&msg, NULL, &curthread->td_msgport,
393 		    0, in_ialink_dispatch);
394 	msg.lmsg.u.ms_resultp = ia;
395 
396 	ifa_domsg(&msg.lmsg, 0);
397 }
398 
399 void
400 in_iaunlink(struct in_ifaddr *ia)
401 {
402 	struct netmsg_base msg;
403 
404 	netmsg_init(&msg, NULL, &curthread->td_msgport,
405 		    0, in_iaunlink_dispatch);
406 	msg.lmsg.u.ms_resultp = ia;
407 
408 	ifa_domsg(&msg.lmsg, 0);
409 }
410 
411 void
412 in_iahash_insert(struct in_ifaddr *ia)
413 {
414 	struct netmsg_base msg;
415 
416 	netmsg_init(&msg, NULL, &curthread->td_msgport,
417 		    0, in_iahashins_dispatch);
418 	msg.lmsg.u.ms_resultp = ia;
419 
420 	ifa_domsg(&msg.lmsg, 0);
421 }
422 
423 void
424 in_iahash_remove(struct in_ifaddr *ia)
425 {
426 	struct netmsg_base msg;
427 
428 	netmsg_init(&msg, NULL, &curthread->td_msgport,
429 		    0, in_iahashrem_dispatch);
430 	msg.lmsg.u.ms_resultp = ia;
431 
432 	ifa_domsg(&msg.lmsg, 0);
433 }
434 
435 static __inline struct in_ifaddr *
436 in_ianext(struct in_ifaddr *oia)
437 {
438 	struct ifaddr_container *ifac;
439 	struct in_ifaddr_container *iac;
440 
441 	ifac = &oia->ia_ifa.ifa_containers[mycpuid];
442 	ASSERT_IFAC_VALID(ifac);
443 	KASSERT(ifac->ifa_listmask & IFA_LIST_IN_IFADDRHEAD,
444 		("ia is not on in_ifaddrheads\n"));
445 
446 	iac = &ifac->ifa_proto_u.u_in_ifac;
447 	iac = TAILQ_NEXT(iac, ia_link);
448 	if (iac != NULL)
449 		return iac->ia;
450 	else
451 		return NULL;
452 }
453 
454 static int
455 in_control_internal(u_long cmd, caddr_t data, struct ifnet *ifp,
456 		    struct thread *td)
457 {
458 	struct ifreq *ifr = (struct ifreq *)data;
459 	struct in_ifaddr *ia = NULL;
460 	struct in_addr dst;
461 	struct in_aliasreq *ifra = (struct in_aliasreq *)data;
462 	struct ifaddr_container *ifac;
463 	struct in_ifaddr_container *iac;
464 	struct sockaddr_in oldaddr;
465 	int hostIsNew, iaIsNew, maskIsNew, ifpWasUp;
466 	int error = 0;
467 
468 	iaIsNew = 0;
469 	ifpWasUp = 0;
470 
471 	/*
472 	 * Find address for this interface, if it exists.
473 	 *
474 	 * If an alias address was specified, find that one instead of
475 	 * the first one on the interface, if possible
476 	 */
477 	if (ifp) {
478 		struct in_ifaddr *iap;
479 
480 		dst = ((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr;
481 		LIST_FOREACH(iac, INADDR_HASH(dst.s_addr), ia_hash) {
482 			iap = iac->ia;
483 			if (iap->ia_ifp == ifp &&
484 			    iap->ia_addr.sin_addr.s_addr == dst.s_addr) {
485 				ia = iap;
486 				break;
487 			}
488 		}
489 		if (ia == NULL) {
490 			TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid],
491 				      ifa_link) {
492 				iap = ifatoia(ifac->ifa);
493 				if (iap->ia_addr.sin_family == AF_INET) {
494 					ia = iap;
495 					break;
496 				}
497 			}
498 		}
499 
500 		if (ifp->if_flags & IFF_UP)
501 			ifpWasUp = 1;
502 	}
503 
504 	switch (cmd) {
505 	case SIOCAIFADDR:
506 	case SIOCDIFADDR:
507 		if (ifp == NULL)
508 			return (EADDRNOTAVAIL);
509 		if (ifra->ifra_addr.sin_family == AF_INET) {
510 			while (ia != NULL) {
511 				if (ia->ia_ifp == ifp  &&
512 				    ia->ia_addr.sin_addr.s_addr ==
513 				    ifra->ifra_addr.sin_addr.s_addr)
514 					break;
515 				ia = in_ianext(ia);
516 			}
517 			if ((ifp->if_flags & IFF_POINTOPOINT) &&
518 			    cmd == SIOCAIFADDR &&
519 			    ifra->ifra_dstaddr.sin_addr.s_addr == INADDR_ANY) {
520 				return EDESTADDRREQ;
521 			}
522 		}
523 		if (cmd == SIOCDIFADDR && ia == NULL)
524 			return (EADDRNOTAVAIL);
525 		/* FALLTHROUGH */
526 	case SIOCSIFADDR:
527 	case SIOCSIFNETMASK:
528 	case SIOCSIFDSTADDR:
529 		if (td && (error = priv_check(td, PRIV_ROOT)) != 0)
530 			return error;
531 
532 		if (ifp == NULL)
533 			return (EADDRNOTAVAIL);
534 
535 		if (cmd == SIOCSIFDSTADDR &&
536 		    (ifp->if_flags & IFF_POINTOPOINT) == 0)
537 			return (EINVAL);
538 
539 		if (ia == NULL) {
540 			struct ifaddr *ifa;
541 			int i;
542 
543 			ia = ifa_create(sizeof(*ia), M_WAITOK);
544 			ifa = &ia->ia_ifa;
545 
546 			/*
547 			 * Setup per-CPU information
548 			 */
549 			for (i = 0; i < ncpus; ++i) {
550 				ifac = &ifa->ifa_containers[i];
551 				iac = &ifac->ifa_proto_u.u_in_ifac;
552 				iac->ia = ia;
553 				iac->ia_ifac = ifac;
554 			}
555 
556 			/*
557 			 * Protect from NETISR_IP traversing address list
558 			 * while we're modifying it.
559 			 */
560 			crit_enter();
561 
562 			in_ialink(ia);
563 			ifa_iflink(ifa, ifp, 1);
564 
565 			ifa->ifa_addr = (struct sockaddr *)&ia->ia_addr;
566 			ifa->ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr;
567 			ifa->ifa_netmask = (struct sockaddr *)&ia->ia_sockmask;
568 			ia->ia_sockmask.sin_len = 8;
569 			ia->ia_sockmask.sin_family = AF_INET;
570 			if (ifp->if_flags & IFF_BROADCAST) {
571 				ia->ia_broadaddr.sin_len = sizeof ia->ia_addr;
572 				ia->ia_broadaddr.sin_family = AF_INET;
573 			}
574 			ia->ia_ifp = ifp;
575 			if (!(ifp->if_flags & IFF_LOOPBACK))
576 				in_interfaces++;
577 			iaIsNew = 1;
578 
579 			crit_exit();
580 		}
581 		break;
582 
583 	case SIOCSIFBRDADDR:
584 		if (td && (error = priv_check(td, PRIV_ROOT)) != 0)
585 			return error;
586 		/* FALLTHROUGH */
587 
588 	case SIOCGIFADDR:
589 	case SIOCGIFNETMASK:
590 	case SIOCGIFDSTADDR:
591 	case SIOCGIFBRDADDR:
592 		if (ia == NULL)
593 			return (EADDRNOTAVAIL);
594 		break;
595 	}
596 
597 	switch (cmd) {
598 	case SIOCGIFADDR:
599 		*((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr;
600 		return (0);
601 
602 	case SIOCGIFBRDADDR:
603 		if ((ifp->if_flags & IFF_BROADCAST) == 0)
604 			return (EINVAL);
605 		*((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr;
606 		return (0);
607 
608 	case SIOCGIFDSTADDR:
609 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
610 			return (EINVAL);
611 		*((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr;
612 		return (0);
613 
614 	case SIOCGIFNETMASK:
615 		*((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask;
616 		return (0);
617 
618 	case SIOCSIFDSTADDR:
619 		KKASSERT(ifp->if_flags & IFF_POINTOPOINT);
620 
621 		oldaddr = ia->ia_dstaddr;
622 		ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr;
623 		if (ifp->if_ioctl != NULL) {
624 			ifnet_serialize_all(ifp);
625 			error = ifp->if_ioctl(ifp, SIOCSIFDSTADDR, (caddr_t)ia,
626 					      td->td_proc->p_ucred);
627 			ifnet_deserialize_all(ifp);
628 			if (error) {
629 				ia->ia_dstaddr = oldaddr;
630 				return (error);
631 			}
632 		}
633 		if (ia->ia_flags & IFA_ROUTE) {
634 			ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr;
635 			rtinit(&ia->ia_ifa, RTM_DELETE, RTF_HOST);
636 			ia->ia_ifa.ifa_dstaddr =
637 					(struct sockaddr *)&ia->ia_dstaddr;
638 			rtinit(&ia->ia_ifa, RTM_ADD, RTF_HOST | RTF_UP);
639 		}
640 		return (0);
641 
642 	case SIOCSIFBRDADDR:
643 		if ((ifp->if_flags & IFF_BROADCAST) == 0)
644 			return (EINVAL);
645 		ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr;
646 		return (0);
647 
648 	case SIOCSIFADDR:
649 		error = in_ifinit(ifp, ia,
650 		    (const struct sockaddr_in *)&ifr->ifr_addr, 1);
651 		if (error != 0 && iaIsNew)
652 			break;
653 		if (error == 0) {
654 			EVENTHANDLER_INVOKE(ifaddr_event, ifp,
655 			iaIsNew ? IFADDR_EVENT_ADD : IFADDR_EVENT_CHANGE,
656 			&ia->ia_ifa);
657 		}
658 		if (!ifpWasUp && (ifp->if_flags & IFF_UP)) {
659 			/*
660 			 * Interface is brought up by in_ifinit()
661 			 * (via ifp->if_ioctl).  We act as if the
662 			 * interface got IFF_UP flag turned on.
663 			 */
664 			if_up(ifp);
665 		}
666 		return (0);
667 
668 	case SIOCSIFNETMASK:
669 		ia->ia_sockmask.sin_addr = ifra->ifra_addr.sin_addr;
670 		ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr);
671 		return (0);
672 
673 	case SIOCAIFADDR:
674 		maskIsNew = 0;
675 		hostIsNew = 1;
676 		error = 0;
677 		if (ia->ia_addr.sin_family == AF_INET) {
678 			if (ifra->ifra_addr.sin_len == 0) {
679 				ifra->ifra_addr = ia->ia_addr;
680 				hostIsNew = 0;
681 			} else if (ifra->ifra_addr.sin_addr.s_addr ==
682 				   ia->ia_addr.sin_addr.s_addr) {
683 				hostIsNew = 0;
684 			}
685 		}
686 		if (ifra->ifra_mask.sin_len) {
687 			in_ifscrub(ifp, ia);
688 			ia->ia_sockmask = ifra->ifra_mask;
689 			ia->ia_sockmask.sin_family = AF_INET;
690 			ia->ia_subnetmask =
691 			    ntohl(ia->ia_sockmask.sin_addr.s_addr);
692 			maskIsNew = 1;
693 		}
694 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
695 		    ifra->ifra_dstaddr.sin_family == AF_INET) {
696 			in_ifscrub(ifp, ia);
697 			ia->ia_dstaddr = ifra->ifra_dstaddr;
698 			maskIsNew  = 1; /* We lie; but the effect's the same */
699 		}
700 		if (ifra->ifra_addr.sin_family == AF_INET &&
701 		    (hostIsNew || maskIsNew))
702 			error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
703 
704 		if (error != 0 && iaIsNew)
705 			break;
706 
707 		if ((ifp->if_flags & IFF_BROADCAST) &&
708 		    ifra->ifra_broadaddr.sin_family == AF_INET)
709 			ia->ia_broadaddr = ifra->ifra_broadaddr;
710 		if (error == 0) {
711 			EVENTHANDLER_INVOKE(ifaddr_event, ifp,
712 			iaIsNew ? IFADDR_EVENT_ADD : IFADDR_EVENT_CHANGE,
713 			&ia->ia_ifa);
714 		}
715 		if (!ifpWasUp && (ifp->if_flags & IFF_UP)) {
716 			/* See the comment in SIOCSIFADDR */
717 			if_up(ifp);
718 		}
719 		return (error);
720 
721 	case SIOCDIFADDR:
722 		/*
723 		 * in_ifscrub kills the interface route.
724 		 */
725 		in_ifscrub(ifp, ia);
726 		/*
727 		 * in_ifadown gets rid of all the rest of
728 		 * the routes.  This is not quite the right
729 		 * thing to do, but at least if we are running
730 		 * a routing process they will come back.
731 		 */
732 		in_ifadown(&ia->ia_ifa, 1);
733 		EVENTHANDLER_INVOKE(ifaddr_event, ifp, IFADDR_EVENT_DELETE,
734 				    &ia->ia_ifa);
735 		error = 0;
736 		break;
737 
738 	default:
739 		if (ifp == NULL || ifp->if_ioctl == NULL)
740 			return (EOPNOTSUPP);
741 		ifnet_serialize_all(ifp);
742 		error = ifp->if_ioctl(ifp, cmd, data, td->td_proc->p_ucred);
743 		ifnet_deserialize_all(ifp);
744 		return (error);
745 	}
746 
747 	KKASSERT(cmd == SIOCDIFADDR ||
748 		 ((cmd == SIOCAIFADDR || cmd == SIOCSIFADDR) && iaIsNew));
749 
750 	ifa_ifunlink(&ia->ia_ifa, ifp);
751 	in_iaunlink(ia);
752 
753 	if (cmd == SIOCDIFADDR) {
754 		ifac = &ia->ia_ifa.ifa_containers[mycpuid];
755 		if (ifac->ifa_listmask & IFA_LIST_IN_IFADDRHASH)
756 			in_iahash_remove(ia);
757 	}
758 #ifdef INVARIANTS
759 	else {
760 		/*
761 		 * If cmd is SIOCSIFADDR or SIOCAIFADDR, in_ifinit() has
762 		 * already taken care of the deletion from hash table
763 		 */
764 		ifac = &ia->ia_ifa.ifa_containers[mycpuid];
765 		KASSERT((ifac->ifa_listmask & IFA_LIST_IN_IFADDRHASH) == 0,
766 			("SIOC%cIFADDR failed on new ia, "
767 			 "but the new ia is still in hash table\n",
768 			 cmd == SIOCSIFADDR ? 'S' : 'A'));
769 	}
770 #endif
771 
772 	ifa_destroy(&ia->ia_ifa);
773 
774 	if ((cmd == SIOCAIFADDR || cmd == SIOCSIFADDR) &&
775 	    !ifpWasUp && (ifp->if_flags & IFF_UP)) {
776 		/*
777 		 * Though the address assignment failed, the
778 		 * interface is brought up by in_ifinit()
779 		 * (via ifp->if_ioctl).  With the hope that
780 		 * the interface has some valid addresses, we
781 		 * act as if IFF_UP flag was just set on the
782 		 * interface.
783 		 *
784 		 * NOTE:
785 		 * This could only be done after the failed
786 		 * address is unlinked from the global address
787 		 * list.
788 		 */
789 		if_up(ifp);
790 	}
791 
792 	return (error);
793 }
794 
795 /*
796  * SIOC[GAD]LIFADDR.
797  *	SIOCGLIFADDR: get first address. (?!?)
798  *	SIOCGLIFADDR with IFLR_PREFIX:
799  *		get first address that matches the specified prefix.
800  *	SIOCALIFADDR: add the specified address.
801  *	SIOCALIFADDR with IFLR_PREFIX:
802  *		EINVAL since we can't deduce hostid part of the address.
803  *	SIOCDLIFADDR: delete the specified address.
804  *	SIOCDLIFADDR with IFLR_PREFIX:
805  *		delete the first address that matches the specified prefix.
806  * return values:
807  *	EINVAL on invalid parameters
808  *	EADDRNOTAVAIL on prefix match failed/specified address not found
809  *	other values may be returned from in_ioctl()
810  *
811  * NOTE! td might be NULL.
812  */
813 static int
814 in_lifaddr_ioctl(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
815 		 struct thread *td)
816 {
817 	struct if_laddrreq *iflr = (struct if_laddrreq *)data;
818 
819 	/* sanity checks */
820 	if (!data || !ifp) {
821 		panic("invalid argument to in_lifaddr_ioctl");
822 		/*NOTRECHED*/
823 	}
824 
825 	switch (cmd) {
826 	case SIOCGLIFADDR:
827 		/* address must be specified on GET with IFLR_PREFIX */
828 		if ((iflr->flags & IFLR_PREFIX) == 0)
829 			break;
830 		/*FALLTHROUGH*/
831 	case SIOCALIFADDR:
832 	case SIOCDLIFADDR:
833 		/* address must be specified on ADD and DELETE */
834 		if (iflr->addr.ss_family != AF_INET)
835 			return EINVAL;
836 		if (iflr->addr.ss_len != sizeof(struct sockaddr_in))
837 			return EINVAL;
838 		/* XXX need improvement */
839 		if (iflr->dstaddr.ss_family
840 		 && iflr->dstaddr.ss_family != AF_INET)
841 			return EINVAL;
842 		if (iflr->dstaddr.ss_family
843 		 && iflr->dstaddr.ss_len != sizeof(struct sockaddr_in))
844 			return EINVAL;
845 		break;
846 	default: /*shouldn't happen*/
847 		return EOPNOTSUPP;
848 	}
849 	if (sizeof(struct in_addr) * 8 < iflr->prefixlen)
850 		return EINVAL;
851 
852 	switch (cmd) {
853 	case SIOCALIFADDR:
854 	    {
855 		struct in_aliasreq ifra;
856 
857 		if (iflr->flags & IFLR_PREFIX)
858 			return EINVAL;
859 
860 		/* copy args to in_aliasreq, perform ioctl(SIOCAIFADDR_IN6). */
861 		bzero(&ifra, sizeof ifra);
862 		bcopy(iflr->iflr_name, ifra.ifra_name, sizeof ifra.ifra_name);
863 
864 		bcopy(&iflr->addr, &ifra.ifra_addr, iflr->addr.ss_len);
865 
866 		if (iflr->dstaddr.ss_family) {	/*XXX*/
867 			bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
868 				iflr->dstaddr.ss_len);
869 		}
870 
871 		ifra.ifra_mask.sin_family = AF_INET;
872 		ifra.ifra_mask.sin_len = sizeof(struct sockaddr_in);
873 		in_len2mask(&ifra.ifra_mask.sin_addr, iflr->prefixlen);
874 
875 		return in_control(so, SIOCAIFADDR, (caddr_t)&ifra, ifp, td);
876 	    }
877 	case SIOCGLIFADDR:
878 	case SIOCDLIFADDR:
879 	    {
880 		struct ifaddr_container *ifac;
881 		struct in_ifaddr *ia;
882 		struct in_addr mask, candidate, match;
883 		struct sockaddr_in *sin;
884 		int cmp;
885 
886 		bzero(&mask, sizeof mask);
887 		if (iflr->flags & IFLR_PREFIX) {
888 			/* lookup a prefix rather than address. */
889 			in_len2mask(&mask, iflr->prefixlen);
890 
891 			sin = (struct sockaddr_in *)&iflr->addr;
892 			match.s_addr = sin->sin_addr.s_addr;
893 			match.s_addr &= mask.s_addr;
894 
895 			/* if you set extra bits, that's wrong */
896 			if (match.s_addr != sin->sin_addr.s_addr)
897 				return EINVAL;
898 
899 			cmp = 1;
900 		} else {
901 			if (cmd == SIOCGLIFADDR) {
902 				/* on getting an address, take the 1st match */
903 				match.s_addr = 0; /* gcc4 warning */
904 				cmp = 0;	/*XXX*/
905 			} else {
906 				/* on deleting an address, do exact match */
907 				in_len2mask(&mask, 32);
908 				sin = (struct sockaddr_in *)&iflr->addr;
909 				match.s_addr = sin->sin_addr.s_addr;
910 
911 				cmp = 1;
912 			}
913 		}
914 
915 		TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
916 			struct ifaddr *ifa = ifac->ifa;
917 
918 			if (ifa->ifa_addr->sa_family != AF_INET6)
919 				continue;
920 			if (!cmp)
921 				break;
922 			candidate.s_addr =
923 			((struct sockaddr_in *)&ifa->ifa_addr)->sin_addr.s_addr;
924 			candidate.s_addr &= mask.s_addr;
925 			if (candidate.s_addr == match.s_addr)
926 				break;
927 		}
928 		if (ifac == NULL)
929 			return EADDRNOTAVAIL;
930 		ia = (struct in_ifaddr *)(ifac->ifa);
931 
932 		if (cmd == SIOCGLIFADDR) {
933 			/* fill in the if_laddrreq structure */
934 			bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin_len);
935 
936 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
937 				bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
938 					ia->ia_dstaddr.sin_len);
939 			} else
940 				bzero(&iflr->dstaddr, sizeof iflr->dstaddr);
941 
942 			iflr->prefixlen =
943 				in_mask2len(&ia->ia_sockmask.sin_addr);
944 
945 			iflr->flags = 0;	/*XXX*/
946 
947 			return 0;
948 		} else {
949 			struct in_aliasreq ifra;
950 
951 			/* fill in_aliasreq and do ioctl(SIOCDIFADDR_IN6) */
952 			bzero(&ifra, sizeof ifra);
953 			bcopy(iflr->iflr_name, ifra.ifra_name,
954 				sizeof ifra.ifra_name);
955 
956 			bcopy(&ia->ia_addr, &ifra.ifra_addr,
957 				ia->ia_addr.sin_len);
958 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
959 				bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
960 					ia->ia_dstaddr.sin_len);
961 			}
962 			bcopy(&ia->ia_sockmask, &ifra.ifra_dstaddr,
963 				ia->ia_sockmask.sin_len);
964 
965 			return in_control(so, SIOCDIFADDR, (caddr_t)&ifra,
966 					  ifp, td);
967 		}
968 	    }
969 	}
970 
971 	return EOPNOTSUPP;	/*just for safety*/
972 }
973 
974 /*
975  * Delete any existing route for an interface.
976  */
977 void
978 in_ifscrub(struct ifnet *ifp __unused, struct in_ifaddr *ia)
979 {
980 	in_scrubprefix(ia);
981 }
982 
983 /*
984  * Initialize an interface's internet address
985  * and routing table entry.
986  */
987 static int
988 in_ifinit(struct ifnet *ifp, struct in_ifaddr *ia,
989 	  const struct sockaddr_in *sin, int scrub)
990 {
991 	u_long i = ntohl(sin->sin_addr.s_addr);
992 	struct sockaddr_in oldaddr;
993 	struct ifaddr_container *ifac;
994 	int flags = RTF_UP, error = 0;
995 	int was_hash = 0;
996 
997 	ifac = &ia->ia_ifa.ifa_containers[mycpuid];
998 	oldaddr = ia->ia_addr;
999 
1000 	if (ifac->ifa_listmask & IFA_LIST_IN_IFADDRHASH) {
1001 		was_hash = 1;
1002 		in_iahash_remove(ia);
1003 	}
1004 
1005 	ia->ia_addr = *sin;
1006 	if (ia->ia_addr.sin_family == AF_INET)
1007 		in_iahash_insert(ia);
1008 
1009 	/*
1010 	 * Give the interface a chance to initialize
1011 	 * if this is its first address,
1012 	 * and to validate the address if necessary.
1013 	 */
1014 	if (ifp->if_ioctl != NULL) {
1015 		ifnet_serialize_all(ifp);
1016 		error = ifp->if_ioctl(ifp, SIOCSIFADDR, (caddr_t)ia, NULL);
1017 		ifnet_deserialize_all(ifp);
1018 		if (error)
1019 			goto fail;
1020 	}
1021 
1022 	/*
1023 	 * Delete old route, if requested.
1024 	 */
1025 	if (scrub) {
1026 		ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr;
1027 		in_ifscrub(ifp, ia);
1028 		ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
1029 	}
1030 
1031 	/*
1032 	 * Calculate netmask/subnetmask.
1033 	 */
1034 	if (IN_CLASSA(i))
1035 		ia->ia_netmask = IN_CLASSA_NET;
1036 	else if (IN_CLASSB(i))
1037 		ia->ia_netmask = IN_CLASSB_NET;
1038 	else
1039 		ia->ia_netmask = IN_CLASSC_NET;
1040 	/*
1041 	 * The subnet mask usually includes at least the standard network part,
1042 	 * but may may be smaller in the case of supernetting.
1043 	 * If it is set, we believe it.
1044 	 */
1045 	if (ia->ia_subnetmask == 0) {
1046 		ia->ia_subnetmask = ia->ia_netmask;
1047 		ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
1048 	} else {
1049 		ia->ia_netmask &= ia->ia_subnetmask;
1050 	}
1051 	ia->ia_net = i & ia->ia_netmask;
1052 	ia->ia_subnet = i & ia->ia_subnetmask;
1053 	in_socktrim(&ia->ia_sockmask);
1054 
1055 	/*
1056 	 * Add route for the network.
1057 	 */
1058 	ia->ia_ifa.ifa_metric = ifp->if_metric;
1059 	if (ifp->if_flags & IFF_BROADCAST) {
1060 		ia->ia_broadaddr.sin_addr.s_addr =
1061 			htonl(ia->ia_subnet | ~ia->ia_subnetmask);
1062 		ia->ia_netbroadcast.s_addr =
1063 			htonl(ia->ia_net | ~ ia->ia_netmask);
1064 	} else if (ifp->if_flags & IFF_LOOPBACK) {
1065 		ia->ia_dstaddr = ia->ia_addr;
1066 		flags |= RTF_HOST;
1067 	} else if (ifp->if_flags & IFF_POINTOPOINT) {
1068 		if (ia->ia_dstaddr.sin_family != AF_INET)
1069 			return (0);
1070 		flags |= RTF_HOST;
1071 	}
1072 
1073 	/*-
1074 	 * Don't add host routes for interface addresses of
1075 	 * 0.0.0.0 --> 0.255.255.255 netmask 255.0.0.0.  This makes it
1076 	 * possible to assign several such address pairs with consistent
1077 	 * results (no host route) and is required by BOOTP.
1078 	 *
1079 	 * XXX: This is ugly !  There should be a way for the caller to
1080 	 *      say that they don't want a host route.
1081 	 */
1082 	if (ia->ia_addr.sin_addr.s_addr != INADDR_ANY ||
1083 	    ia->ia_netmask != IN_CLASSA_NET ||
1084 	    ia->ia_dstaddr.sin_addr.s_addr != htonl(IN_CLASSA_HOST)) {
1085 		error = in_addprefix(ia, flags);
1086 		if (error)
1087 			goto fail;
1088 	}
1089 
1090 	/*
1091 	 * If the interface supports multicast, join the "all hosts"
1092 	 * multicast group on that interface.
1093 	 */
1094 	if (ifp->if_flags & IFF_MULTICAST) {
1095 		struct in_addr addr;
1096 
1097 		addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
1098 		in_addmulti(&addr, ifp);
1099 	}
1100 	return (0);
1101 fail:
1102 	if (ifac->ifa_listmask & IFA_LIST_IN_IFADDRHASH)
1103 		in_iahash_remove(ia);
1104 
1105 	ia->ia_addr = oldaddr;
1106 	if (was_hash)
1107 		in_iahash_insert(ia);
1108 	return (error);
1109 }
1110 
1111 #define rtinitflags(x) \
1112 	(((x)->ia_ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) \
1113 	 ? RTF_HOST : 0)
1114 
1115 /*
1116  * Add a route to prefix ("connected route" in cisco terminology).
1117  * Do nothing, if there are some interface addresses with the same
1118  * prefix already.  This function assumes that the 'target' parent
1119  * interface is UP.
1120  */
1121 static int
1122 in_addprefix(struct in_ifaddr *target, int flags)
1123 {
1124 	struct in_ifaddr_container *iac;
1125 	struct in_addr prefix, mask;
1126 	int error;
1127 
1128 #ifdef CARP
1129 	/*
1130 	 * Don't add prefix routes for CARP interfaces.
1131 	 * Prefix routes creation is handled by CARP
1132 	 * interfaces themselves.
1133 	 */
1134 	if (target->ia_ifp->if_type == IFT_CARP)
1135 		return 0;
1136 #endif
1137 
1138 	mask = target->ia_sockmask.sin_addr;
1139 	if (flags & RTF_HOST) {
1140 		prefix = target->ia_dstaddr.sin_addr;
1141 	} else {
1142 		prefix = target->ia_addr.sin_addr;
1143 		prefix.s_addr &= mask.s_addr;
1144 	}
1145 
1146 	TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) {
1147 		struct in_ifaddr *ia = iac->ia;
1148 		struct in_addr p;
1149 
1150 		/* Don't test against self */
1151 		if (ia == target)
1152 			continue;
1153 
1154 		/* The tested address does not own a route entry */
1155 		if ((ia->ia_flags & IFA_ROUTE) == 0)
1156 			continue;
1157 
1158 		/* Prefix test */
1159 		if (rtinitflags(ia)) {
1160 			p = ia->ia_dstaddr.sin_addr;
1161 		} else {
1162 			p = ia->ia_addr.sin_addr;
1163 			p.s_addr &= ia->ia_sockmask.sin_addr.s_addr;
1164 		}
1165 		if (prefix.s_addr != p.s_addr)
1166 			continue;
1167 
1168 		/*
1169 		 * If the to-be-added address and the curretly being
1170 		 * tested address are not host addresses, we need to
1171 		 * take subnetmask into consideration.
1172 		 */
1173 		if (!(flags & RTF_HOST) && !rtinitflags(ia) &&
1174 		    mask.s_addr != ia->ia_sockmask.sin_addr.s_addr)
1175 			continue;
1176 
1177 		/*
1178 		 * If we got a matching prefix route inserted by other
1179 		 * interface address, we don't need to bother.
1180 		 */
1181 		return 0;
1182 	}
1183 
1184 	/*
1185 	 * No one seem to have prefix route; insert it.
1186 	 */
1187 	error = rtinit(&target->ia_ifa, RTM_ADD, flags);
1188 	if (!error)
1189 		target->ia_flags |= IFA_ROUTE;
1190 	return error;
1191 }
1192 
1193 /*
1194  * Remove a route to prefix ("connected route" in cisco terminology).
1195  * Re-installs the route by using another interface address, if there's
1196  * one with the same prefix (otherwise we lose the route mistakenly).
1197  */
1198 static void
1199 in_scrubprefix(struct in_ifaddr *target)
1200 {
1201 	struct in_ifaddr_container *iac;
1202 	struct in_addr prefix, mask;
1203 	int error;
1204 
1205 	if ((target->ia_flags & IFA_ROUTE) == 0)
1206 		return;
1207 
1208 	mask = target->ia_sockmask.sin_addr;
1209 	if (rtinitflags(target)) {
1210 		prefix = target->ia_dstaddr.sin_addr;
1211 	} else {
1212 		prefix = target->ia_addr.sin_addr;
1213 		prefix.s_addr &= mask.s_addr;
1214 	}
1215 
1216 	TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) {
1217 		struct in_ifaddr *ia = iac->ia;
1218 		struct in_addr p;
1219 
1220 		/* Don't test against self */
1221 		if (ia == target)
1222 			continue;
1223 
1224 		/* The tested address already owns a route entry */
1225 		if (ia->ia_flags & IFA_ROUTE)
1226 			continue;
1227 
1228 		/*
1229 		 * The prefix route of the tested address should
1230 		 * never be installed if its parent interface is
1231 		 * not UP yet.
1232 		 */
1233 		if ((ia->ia_ifp->if_flags & IFF_UP) == 0)
1234 			continue;
1235 
1236 #ifdef CARP
1237 		/*
1238 		 * Don't add prefix routes for CARP interfaces.
1239 		 * Prefix routes creation is handled by CARP
1240 		 * interfaces themselves.
1241 		 */
1242 		if (ia->ia_ifp->if_type == IFT_CARP)
1243 			continue;
1244 #endif
1245 
1246 		/* Prefix test */
1247 		if (rtinitflags(ia)) {
1248 			p = ia->ia_dstaddr.sin_addr;
1249 		} else {
1250 			p = ia->ia_addr.sin_addr;
1251 			p.s_addr &= ia->ia_sockmask.sin_addr.s_addr;
1252 		}
1253 		if (prefix.s_addr != p.s_addr)
1254 			continue;
1255 
1256 		/*
1257 		 * We don't need to test subnetmask here, as what we do
1258 		 * in in_addprefix(), since if the the tested address's
1259 		 * parent interface is UP, the tested address should own
1260 		 * a prefix route entry and we would never reach here.
1261 		 */
1262 
1263 		/*
1264 		 * If we got a matching prefix route, move IFA_ROUTE to him
1265 		 */
1266 		rtinit(&target->ia_ifa, RTM_DELETE, rtinitflags(target));
1267 		target->ia_flags &= ~IFA_ROUTE;
1268 
1269 		error = rtinit(&ia->ia_ifa, RTM_ADD, rtinitflags(ia) | RTF_UP);
1270 		if (!error)
1271 			ia->ia_flags |= IFA_ROUTE;
1272 		return;
1273 	}
1274 
1275 	/*
1276 	 * No candidates for this prefix route; just remove it.
1277 	 */
1278 	rtinit(&target->ia_ifa, RTM_DELETE, rtinitflags(target));
1279 	target->ia_flags &= ~IFA_ROUTE;
1280 }
1281 
1282 #undef rtinitflags
1283 
1284 /*
1285  * Return 1 if the address might be a local broadcast address.
1286  */
1287 int
1288 in_broadcast(struct in_addr in, struct ifnet *ifp)
1289 {
1290 	struct ifaddr_container *ifac;
1291 	u_long t;
1292 
1293 	if (in.s_addr == INADDR_BROADCAST ||
1294 	    in.s_addr == INADDR_ANY)
1295 		return 1;
1296 	if ((ifp->if_flags & IFF_BROADCAST) == 0)
1297 		return 0;
1298 	t = ntohl(in.s_addr);
1299 	/*
1300 	 * Look through the list of addresses for a match
1301 	 * with a broadcast address.
1302 	 */
1303 #define ia ((struct in_ifaddr *)ifa)
1304 	TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
1305 		struct ifaddr *ifa = ifac->ifa;
1306 
1307 		if (ifa->ifa_addr->sa_family == AF_INET &&
1308 		    (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
1309 		     in.s_addr == ia->ia_netbroadcast.s_addr ||
1310 		     /*
1311 		      * Check for old-style (host 0) broadcast.
1312 		      */
1313 		     t == ia->ia_subnet || t == ia->ia_net) &&
1314 		     /*
1315 		      * Check for an all one subnetmask. These
1316 		      * only exist when an interface gets a secondary
1317 		      * address.
1318 		      */
1319 		     ia->ia_subnetmask != (u_long)0xffffffff)
1320 			    return 1;
1321 	}
1322 	return (0);
1323 #undef ia
1324 }
1325 /*
1326  * Add an address to the list of IP multicast addresses for a given interface.
1327  */
1328 struct in_multi *
1329 in_addmulti(struct in_addr *ap, struct ifnet *ifp)
1330 {
1331 	struct in_multi *inm;
1332 	int error;
1333 	struct sockaddr_in sin;
1334 	struct ifmultiaddr *ifma;
1335 
1336 	/*
1337 	 * Call generic routine to add membership or increment
1338 	 * refcount.  It wants addresses in the form of a sockaddr,
1339 	 * so we build one here (being careful to zero the unused bytes).
1340 	 */
1341 	bzero(&sin, sizeof sin);
1342 	sin.sin_family = AF_INET;
1343 	sin.sin_len = sizeof sin;
1344 	sin.sin_addr = *ap;
1345 	crit_enter();
1346 	error = if_addmulti(ifp, (struct sockaddr *)&sin, &ifma);
1347 	if (error) {
1348 		crit_exit();
1349 		return 0;
1350 	}
1351 
1352 	/*
1353 	 * If ifma->ifma_protospec is null, then if_addmulti() created
1354 	 * a new record.  Otherwise, we are done.
1355 	 */
1356 	if (ifma->ifma_protospec != 0) {
1357 		crit_exit();
1358 		return ifma->ifma_protospec;
1359 	}
1360 
1361 	/* XXX - if_addmulti uses M_WAITOK.  Can this really be called
1362 	   at interrupt time?  If so, need to fix if_addmulti. XXX */
1363 	inm = kmalloc(sizeof *inm, M_IPMADDR, M_WAITOK | M_ZERO);
1364 	inm->inm_addr = *ap;
1365 	inm->inm_ifp = ifp;
1366 	inm->inm_ifma = ifma;
1367 	ifma->ifma_protospec = inm;
1368 	LIST_INSERT_HEAD(&in_multihead, inm, inm_link);
1369 
1370 	/*
1371 	 * Let IGMP know that we have joined a new IP multicast group.
1372 	 */
1373 	igmp_joingroup(inm);
1374 	crit_exit();
1375 	return (inm);
1376 }
1377 
1378 /*
1379  * Delete a multicast address record.
1380  */
1381 void
1382 in_delmulti(struct in_multi *inm)
1383 {
1384 	struct ifmultiaddr *ifma;
1385 	struct in_multi my_inm;
1386 
1387 	crit_enter();
1388 	ifma = inm->inm_ifma;
1389 	my_inm.inm_ifp = NULL ; /* don't send the leave msg */
1390 	if (ifma->ifma_refcount == 1) {
1391 		/*
1392 		 * No remaining claims to this record; let IGMP know that
1393 		 * we are leaving the multicast group.
1394 		 * But do it after the if_delmulti() which might reset
1395 		 * the interface and nuke the packet.
1396 		 */
1397 		my_inm = *inm ;
1398 		ifma->ifma_protospec = 0;
1399 		LIST_REMOVE(inm, inm_link);
1400 		kfree(inm, M_IPMADDR);
1401 	}
1402 	/* XXX - should be separate API for when we have an ifma? */
1403 	if_delmulti(ifma->ifma_ifp, ifma->ifma_addr);
1404 	if (my_inm.inm_ifp != NULL)
1405 		igmp_leavegroup(&my_inm);
1406 	crit_exit();
1407 }
1408 
1409 void
1410 in_ifdetach(struct ifnet *ifp)
1411 {
1412 	in_pcbpurgeif0(LIST_FIRST(&ripcbinfo.pcblisthead), ifp);
1413 
1414 	udbinfo_lock();
1415 	in_pcbpurgeif0(LIST_FIRST(&udbinfo.pcblisthead), ifp);
1416 	udbinfo_unlock();
1417 }
1418