xref: /netbsd-src/sys/netinet/in.c (revision 8ac07aec990b9d2e483062509d0a9fa5b4f57cf2)
1 /*	$NetBSD: in.c,v 1.124 2008/04/10 18:09:14 dyoung Exp $	*/
2 
3 /*
4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the project nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 /*-
33  * Copyright (c) 1998 The NetBSD Foundation, Inc.
34  * All rights reserved.
35  *
36  * This code is derived from software contributed to The NetBSD Foundation
37  * by Public Access Networks Corporation ("Panix").  It was developed under
38  * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon.
39  *
40  * Redistribution and use in source and binary forms, with or without
41  * modification, are permitted provided that the following conditions
42  * are met:
43  * 1. Redistributions of source code must retain the above copyright
44  *    notice, this list of conditions and the following disclaimer.
45  * 2. Redistributions in binary form must reproduce the above copyright
46  *    notice, this list of conditions and the following disclaimer in the
47  *    documentation and/or other materials provided with the distribution.
48  * 3. All advertising materials mentioning features or use of this software
49  *    must display the following acknowledgement:
50  *	This product includes software developed by the NetBSD
51  *	Foundation, Inc. and its contributors.
52  * 4. Neither the name of The NetBSD Foundation nor the names of its
53  *    contributors may be used to endorse or promote products derived
54  *    from this software without specific prior written permission.
55  *
56  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
57  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
58  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
59  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
60  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
61  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
62  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
63  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
64  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
65  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
66  * POSSIBILITY OF SUCH DAMAGE.
67  */
68 
69 /*
70  * Copyright (c) 1982, 1986, 1991, 1993
71  *	The Regents of the University of California.  All rights reserved.
72  *
73  * Redistribution and use in source and binary forms, with or without
74  * modification, are permitted provided that the following conditions
75  * are met:
76  * 1. Redistributions of source code must retain the above copyright
77  *    notice, this list of conditions and the following disclaimer.
78  * 2. Redistributions in binary form must reproduce the above copyright
79  *    notice, this list of conditions and the following disclaimer in the
80  *    documentation and/or other materials provided with the distribution.
81  * 3. Neither the name of the University nor the names of its contributors
82  *    may be used to endorse or promote products derived from this software
83  *    without specific prior written permission.
84  *
85  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
86  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
87  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
88  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
89  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
90  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
91  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
92  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
93  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
94  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
95  * SUCH DAMAGE.
96  *
97  *	@(#)in.c	8.4 (Berkeley) 1/9/95
98  */
99 
100 #include <sys/cdefs.h>
101 __KERNEL_RCSID(0, "$NetBSD: in.c,v 1.124 2008/04/10 18:09:14 dyoung Exp $");
102 
103 #include "opt_inet.h"
104 #include "opt_inet_conf.h"
105 #include "opt_mrouting.h"
106 #include "opt_pfil_hooks.h"
107 
108 #include <sys/param.h>
109 #include <sys/ioctl.h>
110 #include <sys/errno.h>
111 #include <sys/malloc.h>
112 #include <sys/socket.h>
113 #include <sys/socketvar.h>
114 #include <sys/sysctl.h>
115 #include <sys/systm.h>
116 #include <sys/proc.h>
117 #include <sys/syslog.h>
118 #include <sys/kauth.h>
119 
120 #include <net/if.h>
121 #include <net/route.h>
122 
123 #include <net/if_ether.h>
124 
125 #include <netinet/in_systm.h>
126 #include <netinet/in.h>
127 #include <netinet/in_var.h>
128 #include <netinet/ip.h>
129 #include <netinet/ip_var.h>
130 #include <netinet/in_ifattach.h>
131 #include <netinet/in_pcb.h>
132 #include <netinet/if_inarp.h>
133 #include <netinet/ip_mroute.h>
134 #include <netinet/igmp_var.h>
135 
136 #ifdef IPSELSRC
137 #include <netinet/in_selsrc.h>
138 #endif
139 
140 #ifdef PFIL_HOOKS
141 #include <net/pfil.h>
142 #endif
143 
144 #ifdef INET
145 static u_int in_mask2len(struct in_addr *);
146 static void in_len2mask(struct in_addr *, u_int);
147 static int in_lifaddr_ioctl(struct socket *, u_long, void *,
148 	struct ifnet *, struct lwp *);
149 
150 static int in_ifaddrpref_ioctl(struct socket *, u_long, void *,
151 	struct ifnet *);
152 static int in_addprefix(struct in_ifaddr *, int);
153 static int in_scrubprefix(struct in_ifaddr *);
154 
155 #ifndef SUBNETSARELOCAL
156 #define	SUBNETSARELOCAL	1
157 #endif
158 
159 #ifndef HOSTZEROBROADCAST
160 #define HOSTZEROBROADCAST 1
161 #endif
162 
163 int subnetsarelocal = SUBNETSARELOCAL;
164 int hostzeroisbroadcast = HOSTZEROBROADCAST;
165 
166 /*
167  * This list is used to keep track of in_multi chains which belong to
168  * deleted interface addresses.  We use in_ifaddr so that a chain head
169  * won't be deallocated until all multicast address record are deleted.
170  */
171 static TAILQ_HEAD(, in_ifaddr) in_mk = TAILQ_HEAD_INITIALIZER(in_mk);
172 
173 /*
174  * Return 1 if an internet address is for a ``local'' host
175  * (one to which we have a connection).  If subnetsarelocal
176  * is true, this includes other subnets of the local net.
177  * Otherwise, it includes only the directly-connected (sub)nets.
178  */
179 int
180 in_localaddr(struct in_addr in)
181 {
182 	struct in_ifaddr *ia;
183 
184 	if (subnetsarelocal) {
185 		TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list)
186 			if ((in.s_addr & ia->ia_netmask) == ia->ia_net)
187 				return (1);
188 	} else {
189 		TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list)
190 			if ((in.s_addr & ia->ia_subnetmask) == ia->ia_subnet)
191 				return (1);
192 	}
193 	return (0);
194 }
195 
196 /*
197  * Determine whether an IP address is in a reserved set of addresses
198  * that may not be forwarded, or whether datagrams to that destination
199  * may be forwarded.
200  */
201 int
202 in_canforward(struct in_addr in)
203 {
204 	u_int32_t net;
205 
206 	if (IN_EXPERIMENTAL(in.s_addr) || IN_MULTICAST(in.s_addr))
207 		return (0);
208 	if (IN_CLASSA(in.s_addr)) {
209 		net = in.s_addr & IN_CLASSA_NET;
210 		if (net == 0 || net == htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
211 			return (0);
212 	}
213 	return (1);
214 }
215 
216 /*
217  * Trim a mask in a sockaddr
218  */
219 void
220 in_socktrim(struct sockaddr_in *ap)
221 {
222 	char *cplim = (char *) &ap->sin_addr;
223 	char *cp = (char *) (&ap->sin_addr + 1);
224 
225 	ap->sin_len = 0;
226 	while (--cp >= cplim)
227 		if (*cp) {
228 			(ap)->sin_len = cp - (char *) (ap) + 1;
229 			break;
230 		}
231 }
232 
233 /*
234  *  Routine to take an Internet address and convert into a
235  *  "dotted quad" representation for printing.
236  */
237 const char *
238 in_fmtaddr(struct in_addr addr)
239 {
240 	static char buf[sizeof("123.456.789.123")];
241 
242 	addr.s_addr = ntohl(addr.s_addr);
243 
244 	snprintf(buf, sizeof(buf), "%d.%d.%d.%d",
245 		(addr.s_addr >> 24) & 0xFF,
246 		(addr.s_addr >> 16) & 0xFF,
247 		(addr.s_addr >>  8) & 0xFF,
248 		(addr.s_addr >>  0) & 0xFF);
249 	return buf;
250 }
251 
252 /*
253  * Maintain the "in_maxmtu" variable, which is the largest
254  * mtu for non-local interfaces with AF_INET addresses assigned
255  * to them that are up.
256  */
257 unsigned long in_maxmtu;
258 
259 void
260 in_setmaxmtu(void)
261 {
262 	struct in_ifaddr *ia;
263 	struct ifnet *ifp;
264 	unsigned long maxmtu = 0;
265 
266 	TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list) {
267 		if ((ifp = ia->ia_ifp) == 0)
268 			continue;
269 		if ((ifp->if_flags & (IFF_UP|IFF_LOOPBACK)) != IFF_UP)
270 			continue;
271 		if (ifp->if_mtu > maxmtu)
272 			maxmtu = ifp->if_mtu;
273 	}
274 	if (maxmtu)
275 		in_maxmtu = maxmtu;
276 }
277 
278 static u_int
279 in_mask2len(struct in_addr *mask)
280 {
281 	u_int x, y;
282 	u_char *p;
283 
284 	p = (u_char *)mask;
285 	for (x = 0; x < sizeof(*mask); x++) {
286 		if (p[x] != 0xff)
287 			break;
288 	}
289 	y = 0;
290 	if (x < sizeof(*mask)) {
291 		for (y = 0; y < NBBY; y++) {
292 			if ((p[x] & (0x80 >> y)) == 0)
293 				break;
294 		}
295 	}
296 	return x * NBBY + y;
297 }
298 
299 static void
300 in_len2mask(struct in_addr *mask, u_int len)
301 {
302 	u_int i;
303 	u_char *p;
304 
305 	p = (u_char *)mask;
306 	bzero(mask, sizeof(*mask));
307 	for (i = 0; i < len / NBBY; i++)
308 		p[i] = 0xff;
309 	if (len % NBBY)
310 		p[i] = (0xff00 >> (len % NBBY)) & 0xff;
311 }
312 
313 /*
314  * Generic internet control operations (ioctl's).
315  * Ifp is 0 if not an interface-specific ioctl.
316  */
317 /* ARGSUSED */
318 int
319 in_control(struct socket *so, u_long cmd, void *data, struct ifnet *ifp,
320     struct lwp *l)
321 {
322 	struct ifreq *ifr = (struct ifreq *)data;
323 	struct in_ifaddr *ia = 0;
324 	struct in_aliasreq *ifra = (struct in_aliasreq *)data;
325 	struct sockaddr_in oldaddr;
326 	int error, hostIsNew, maskIsNew;
327 	int newifaddr = 0;
328 
329 	switch (cmd) {
330 	case SIOCALIFADDR:
331 	case SIOCDLIFADDR:
332 	case SIOCSIFADDRPREF:
333 		if (l == NULL)
334 			return (EPERM);
335 		if (kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE,
336 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
337 		    NULL) != 0)
338 			return (EPERM);
339 		/*FALLTHROUGH*/
340 	case SIOCGIFADDRPREF:
341 	case SIOCGLIFADDR:
342 		if (ifp == NULL)
343 			return EINVAL;
344 		if (cmd == SIOCGIFADDRPREF || cmd == SIOCSIFADDRPREF)
345 			return in_ifaddrpref_ioctl(so, cmd, data, ifp);
346 		else
347 			return in_lifaddr_ioctl(so, cmd, data, ifp, l);
348 	}
349 
350 	/*
351 	 * Find address for this interface, if it exists.
352 	 */
353 	if (ifp != NULL)
354 		IFP_TO_IA(ifp, ia);
355 
356 	switch (cmd) {
357 
358 	case SIOCAIFADDR:
359 	case SIOCDIFADDR:
360 	case SIOCGIFALIAS:
361 		if (ifra->ifra_addr.sin_family == AF_INET)
362 			LIST_FOREACH(ia,
363 			    &IN_IFADDR_HASH(ifra->ifra_addr.sin_addr.s_addr),
364 			    ia_hash) {
365 				if (ia->ia_ifp == ifp &&
366 				    in_hosteq(ia->ia_addr.sin_addr,
367 				    ifra->ifra_addr.sin_addr))
368 					break;
369 			}
370 		if ((cmd == SIOCDIFADDR || cmd == SIOCGIFALIAS) && ia == NULL)
371 			return (EADDRNOTAVAIL);
372 
373 #if 1 /*def COMPAT_43*/
374 		if (cmd == SIOCDIFADDR &&
375 		    ifra->ifra_addr.sin_family == AF_UNSPEC) {
376 			ifra->ifra_addr.sin_family = AF_INET;
377 		}
378 #endif
379 		/* FALLTHROUGH */
380 	case SIOCSIFADDR:
381 	case SIOCSIFDSTADDR:
382 		if (ifra->ifra_addr.sin_family != AF_INET)
383 			return (EAFNOSUPPORT);
384 		/* FALLTHROUGH */
385 	case SIOCSIFNETMASK:
386 		if (ifp == NULL)
387 			panic("in_control");
388 
389 		if (cmd == SIOCGIFALIAS)
390 			break;
391 
392 		if (ia == NULL &&
393 		    (cmd == SIOCSIFNETMASK || cmd == SIOCSIFDSTADDR))
394 			return (EADDRNOTAVAIL);
395 
396 		if (l == NULL)
397 			return (EPERM);
398 		if (kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE,
399 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
400 		    NULL) != 0)
401 			return (EPERM);
402 
403 		if (ia == 0) {
404 			MALLOC(ia, struct in_ifaddr *, sizeof(*ia),
405 			       M_IFADDR, M_WAITOK);
406 			if (ia == 0)
407 				return (ENOBUFS);
408 			bzero((void *)ia, sizeof *ia);
409 			TAILQ_INSERT_TAIL(&in_ifaddrhead, ia, ia_list);
410 			IFAREF(&ia->ia_ifa);
411 			ifa_insert(ifp, &ia->ia_ifa);
412 			ia->ia_ifa.ifa_addr = sintosa(&ia->ia_addr);
413 			ia->ia_ifa.ifa_dstaddr = sintosa(&ia->ia_dstaddr);
414 			ia->ia_ifa.ifa_netmask = sintosa(&ia->ia_sockmask);
415 #ifdef IPSELSRC
416 			ia->ia_ifa.ifa_getifa = in_getifa;
417 #else /* IPSELSRC */
418 			ia->ia_ifa.ifa_getifa = NULL;
419 #endif /* IPSELSRC */
420 			ia->ia_sockmask.sin_len = 8;
421 			if (ifp->if_flags & IFF_BROADCAST) {
422 				ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr);
423 				ia->ia_broadaddr.sin_family = AF_INET;
424 			}
425 			ia->ia_ifp = ifp;
426 			ia->ia_idsalt = arc4random() % 65535;
427 			LIST_INIT(&ia->ia_multiaddrs);
428 			newifaddr = 1;
429 		}
430 		break;
431 
432 	case SIOCSIFBRDADDR:
433 		if (l == NULL)
434 			return (EPERM);
435 		if (kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE,
436 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
437 		    NULL) != 0)
438 			return (EPERM);
439 		/* FALLTHROUGH */
440 
441 	case SIOCGIFADDR:
442 	case SIOCGIFNETMASK:
443 	case SIOCGIFDSTADDR:
444 	case SIOCGIFBRDADDR:
445 		if (ia == 0)
446 			return (EADDRNOTAVAIL);
447 		break;
448 	}
449 	error = 0;
450 	switch (cmd) {
451 
452 	case SIOCGIFADDR:
453 		ifreq_setaddr(cmd, ifr, sintocsa(&ia->ia_addr));
454 		break;
455 
456 	case SIOCGIFBRDADDR:
457 		if ((ifp->if_flags & IFF_BROADCAST) == 0)
458 			return (EINVAL);
459 		ifreq_setdstaddr(cmd, ifr, sintocsa(&ia->ia_broadaddr));
460 		break;
461 
462 	case SIOCGIFDSTADDR:
463 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
464 			return (EINVAL);
465 		ifreq_setdstaddr(cmd, ifr, sintocsa(&ia->ia_dstaddr));
466 		break;
467 
468 	case SIOCGIFNETMASK:
469 		ifreq_setaddr(cmd, ifr, sintocsa(&ia->ia_sockmask));
470 		break;
471 
472 	case SIOCSIFDSTADDR:
473 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
474 			return (EINVAL);
475 		oldaddr = ia->ia_dstaddr;
476 		ia->ia_dstaddr = *satocsin(ifreq_getdstaddr(cmd, ifr));
477 		if (ifp->if_ioctl != NULL &&
478 		    (error = (*ifp->if_ioctl)(ifp, SIOCSIFDSTADDR,
479 		                              (void *)ia)) != 0) {
480 			ia->ia_dstaddr = oldaddr;
481 			return error;
482 		}
483 		if (ia->ia_flags & IFA_ROUTE) {
484 			ia->ia_ifa.ifa_dstaddr = sintosa(&oldaddr);
485 			rtinit(&ia->ia_ifa, RTM_DELETE, RTF_HOST);
486 			ia->ia_ifa.ifa_dstaddr = sintosa(&ia->ia_dstaddr);
487 			rtinit(&ia->ia_ifa, RTM_ADD, RTF_HOST|RTF_UP);
488 		}
489 		break;
490 
491 	case SIOCSIFBRDADDR:
492 		if ((ifp->if_flags & IFF_BROADCAST) == 0)
493 			return EINVAL;
494 		ia->ia_broadaddr = *satocsin(ifreq_getbroadaddr(cmd, ifr));
495 		break;
496 
497 	case SIOCSIFADDR:
498 		error = in_ifinit(ifp, ia, satocsin(ifreq_getaddr(cmd, ifr)),
499 		    1);
500 #ifdef PFIL_HOOKS
501 		if (error == 0)
502 			(void)pfil_run_hooks(&if_pfil,
503 			    (struct mbuf **)SIOCSIFADDR, ifp, PFIL_IFADDR);
504 #endif
505 		break;
506 
507 	case SIOCSIFNETMASK:
508 		in_ifscrub(ifp, ia);
509 		ia->ia_sockmask = *satocsin(ifreq_getaddr(cmd, ifr));
510 		ia->ia_subnetmask = ia->ia_sockmask.sin_addr.s_addr;
511 		error = in_ifinit(ifp, ia, NULL, 0);
512 		break;
513 
514 	case SIOCAIFADDR:
515 		maskIsNew = 0;
516 		hostIsNew = 1;
517 		if (ia->ia_addr.sin_family != AF_INET)
518 			;
519 		else if (ifra->ifra_addr.sin_len == 0) {
520 			ifra->ifra_addr = ia->ia_addr;
521 			hostIsNew = 0;
522 		} else if (in_hosteq(ia->ia_addr.sin_addr,
523 		           ifra->ifra_addr.sin_addr))
524 			hostIsNew = 0;
525 		if (ifra->ifra_mask.sin_len) {
526 			in_ifscrub(ifp, ia);
527 			ia->ia_sockmask = ifra->ifra_mask;
528 			ia->ia_subnetmask = ia->ia_sockmask.sin_addr.s_addr;
529 			maskIsNew = 1;
530 		}
531 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
532 		    (ifra->ifra_dstaddr.sin_family == AF_INET)) {
533 			in_ifscrub(ifp, ia);
534 			ia->ia_dstaddr = ifra->ifra_dstaddr;
535 			maskIsNew  = 1; /* We lie; but the effect's the same */
536 		}
537 		if (ifra->ifra_addr.sin_family == AF_INET &&
538 		    (hostIsNew || maskIsNew)) {
539 			error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
540 		}
541 		if ((ifp->if_flags & IFF_BROADCAST) &&
542 		    (ifra->ifra_broadaddr.sin_family == AF_INET))
543 			ia->ia_broadaddr = ifra->ifra_broadaddr;
544 #ifdef PFIL_HOOKS
545 		if (error == 0)
546 			(void)pfil_run_hooks(&if_pfil,
547 			    (struct mbuf **)SIOCAIFADDR, ifp, PFIL_IFADDR);
548 #endif
549 		break;
550 
551 	case SIOCGIFALIAS:
552 		ifra->ifra_mask = ia->ia_sockmask;
553 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
554 		    (ia->ia_dstaddr.sin_family == AF_INET))
555 			ifra->ifra_dstaddr = ia->ia_dstaddr;
556 		else if ((ifp->if_flags & IFF_BROADCAST) &&
557 		    (ia->ia_broadaddr.sin_family == AF_INET))
558 			ifra->ifra_broadaddr = ia->ia_broadaddr;
559 		else
560 			memset(&ifra->ifra_broadaddr, 0,
561 			      sizeof(ifra->ifra_broadaddr));
562 		break;
563 
564 	case SIOCDIFADDR:
565 		in_purgeaddr(&ia->ia_ifa);
566 #ifdef PFIL_HOOKS
567 		(void)pfil_run_hooks(&if_pfil, (struct mbuf **)SIOCDIFADDR,
568 		    ifp, PFIL_IFADDR);
569 #endif
570 		break;
571 
572 #ifdef MROUTING
573 	case SIOCGETVIFCNT:
574 	case SIOCGETSGCNT:
575 		error = mrt_ioctl(so, cmd, data);
576 		break;
577 #endif /* MROUTING */
578 
579 	default:
580 		if (ifp == NULL || ifp->if_ioctl == NULL)
581 			return EOPNOTSUPP;
582 		error = (*ifp->if_ioctl)(ifp, cmd, data);
583 		in_setmaxmtu();
584 		break;
585 	}
586 
587 	if (error != 0 && newifaddr) {
588 		KASSERT(ia != NULL);
589 		in_purgeaddr(&ia->ia_ifa);
590 	}
591 
592 	return error;
593 }
594 
595 void
596 in_purgeaddr(struct ifaddr *ifa)
597 {
598 	struct ifnet *ifp = ifa->ifa_ifp;
599 	struct in_ifaddr *ia = (void *) ifa;
600 
601 	in_ifscrub(ifp, ia);
602 	LIST_REMOVE(ia, ia_hash);
603 	ifa_remove(ifp, &ia->ia_ifa);
604 	TAILQ_REMOVE(&in_ifaddrhead, ia, ia_list);
605 	if (ia->ia_allhosts != NULL)
606 		in_delmulti(ia->ia_allhosts);
607 	IFAFREE(&ia->ia_ifa);
608 	in_setmaxmtu();
609 }
610 
611 void
612 in_purgeif(struct ifnet *ifp)		/* MUST be called at splsoftnet() */
613 {
614 	if_purgeaddrs(ifp, AF_INET, in_purgeaddr);
615 	igmp_purgeif(ifp);		/* manipulates pools */
616 #ifdef MROUTING
617 	ip_mrouter_detach(ifp);
618 #endif
619 }
620 
621 /*
622  * SIOC[GAD]LIFADDR.
623  *	SIOCGLIFADDR: get first address. (???)
624  *	SIOCGLIFADDR with IFLR_PREFIX:
625  *		get first address that matches the specified prefix.
626  *	SIOCALIFADDR: add the specified address.
627  *	SIOCALIFADDR with IFLR_PREFIX:
628  *		EINVAL since we can't deduce hostid part of the address.
629  *	SIOCDLIFADDR: delete the specified address.
630  *	SIOCDLIFADDR with IFLR_PREFIX:
631  *		delete the first address that matches the specified prefix.
632  * return values:
633  *	EINVAL on invalid parameters
634  *	EADDRNOTAVAIL on prefix match failed/specified address not found
635  *	other values may be returned from in_ioctl()
636  */
637 static int
638 in_lifaddr_ioctl(struct socket *so, u_long cmd, void *data,
639     struct ifnet *ifp, struct lwp *l)
640 {
641 	struct if_laddrreq *iflr = (struct if_laddrreq *)data;
642 	struct ifaddr *ifa;
643 	struct sockaddr *sa;
644 
645 	/* sanity checks */
646 	if (data == NULL || ifp == NULL) {
647 		panic("invalid argument to in_lifaddr_ioctl");
648 		/*NOTRECHED*/
649 	}
650 
651 	switch (cmd) {
652 	case SIOCGLIFADDR:
653 		/* address must be specified on GET with IFLR_PREFIX */
654 		if ((iflr->flags & IFLR_PREFIX) == 0)
655 			break;
656 		/*FALLTHROUGH*/
657 	case SIOCALIFADDR:
658 	case SIOCDLIFADDR:
659 		/* address must be specified on ADD and DELETE */
660 		sa = (struct sockaddr *)&iflr->addr;
661 		if (sa->sa_family != AF_INET)
662 			return EINVAL;
663 		if (sa->sa_len != sizeof(struct sockaddr_in))
664 			return EINVAL;
665 		/* XXX need improvement */
666 		sa = (struct sockaddr *)&iflr->dstaddr;
667 		if (sa->sa_family
668 		 && sa->sa_family != AF_INET)
669 			return EINVAL;
670 		if (sa->sa_len && sa->sa_len != sizeof(struct sockaddr_in))
671 			return EINVAL;
672 		break;
673 	default: /*shouldn't happen*/
674 #if 0
675 		panic("invalid cmd to in_lifaddr_ioctl");
676 		/*NOTREACHED*/
677 #else
678 		return EOPNOTSUPP;
679 #endif
680 	}
681 	if (sizeof(struct in_addr) * NBBY < iflr->prefixlen)
682 		return EINVAL;
683 
684 	switch (cmd) {
685 	case SIOCALIFADDR:
686 	    {
687 		struct in_aliasreq ifra;
688 
689 		if (iflr->flags & IFLR_PREFIX)
690 			return EINVAL;
691 
692 		/* copy args to in_aliasreq, perform ioctl(SIOCAIFADDR). */
693 		bzero(&ifra, sizeof(ifra));
694 		bcopy(iflr->iflr_name, ifra.ifra_name,
695 			sizeof(ifra.ifra_name));
696 
697 		bcopy(&iflr->addr, &ifra.ifra_addr,
698 			((struct sockaddr *)&iflr->addr)->sa_len);
699 
700 		if (((struct sockaddr *)&iflr->dstaddr)->sa_family) {	/*XXX*/
701 			bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
702 				((struct sockaddr *)&iflr->dstaddr)->sa_len);
703 		}
704 
705 		ifra.ifra_mask.sin_family = AF_INET;
706 		ifra.ifra_mask.sin_len = sizeof(struct sockaddr_in);
707 		in_len2mask(&ifra.ifra_mask.sin_addr, iflr->prefixlen);
708 
709 		return in_control(so, SIOCAIFADDR, (void *)&ifra, ifp, l);
710 	    }
711 	case SIOCGLIFADDR:
712 	case SIOCDLIFADDR:
713 	    {
714 		struct in_ifaddr *ia;
715 		struct in_addr mask, candidate, match;
716 		struct sockaddr_in *sin;
717 		int cmp;
718 
719 		bzero(&mask, sizeof(mask));
720 		bzero(&match, sizeof(match));	/* XXX gcc */
721 		if (iflr->flags & IFLR_PREFIX) {
722 			/* lookup a prefix rather than address. */
723 			in_len2mask(&mask, iflr->prefixlen);
724 
725 			sin = (struct sockaddr_in *)&iflr->addr;
726 			match.s_addr = sin->sin_addr.s_addr;
727 			match.s_addr &= mask.s_addr;
728 
729 			/* if you set extra bits, that's wrong */
730 			if (match.s_addr != sin->sin_addr.s_addr)
731 				return EINVAL;
732 
733 			cmp = 1;
734 		} else {
735 			if (cmd == SIOCGLIFADDR) {
736 				/* on getting an address, take the 1st match */
737 				cmp = 0;	/*XXX*/
738 			} else {
739 				/* on deleting an address, do exact match */
740 				in_len2mask(&mask, 32);
741 				sin = (struct sockaddr_in *)&iflr->addr;
742 				match.s_addr = sin->sin_addr.s_addr;
743 
744 				cmp = 1;
745 			}
746 		}
747 
748 		IFADDR_FOREACH(ifa, ifp) {
749 			if (ifa->ifa_addr->sa_family != AF_INET)
750 				continue;
751 			if (cmp == 0)
752 				break;
753 			candidate.s_addr = ((struct sockaddr_in *)&ifa->ifa_addr)->sin_addr.s_addr;
754 			candidate.s_addr &= mask.s_addr;
755 			if (candidate.s_addr == match.s_addr)
756 				break;
757 		}
758 		if (ifa == NULL)
759 			return EADDRNOTAVAIL;
760 		ia = (struct in_ifaddr *)ifa;
761 
762 		if (cmd == SIOCGLIFADDR) {
763 			/* fill in the if_laddrreq structure */
764 			bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin_len);
765 
766 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
767 				bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
768 					ia->ia_dstaddr.sin_len);
769 			} else
770 				bzero(&iflr->dstaddr, sizeof(iflr->dstaddr));
771 
772 			iflr->prefixlen =
773 				in_mask2len(&ia->ia_sockmask.sin_addr);
774 
775 			iflr->flags = 0;	/*XXX*/
776 
777 			return 0;
778 		} else {
779 			struct in_aliasreq ifra;
780 
781 			/* fill in_aliasreq and do ioctl(SIOCDIFADDR) */
782 			bzero(&ifra, sizeof(ifra));
783 			bcopy(iflr->iflr_name, ifra.ifra_name,
784 				sizeof(ifra.ifra_name));
785 
786 			bcopy(&ia->ia_addr, &ifra.ifra_addr,
787 				ia->ia_addr.sin_len);
788 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
789 				bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
790 					ia->ia_dstaddr.sin_len);
791 			}
792 			bcopy(&ia->ia_sockmask, &ifra.ifra_dstaddr,
793 				ia->ia_sockmask.sin_len);
794 
795 			return in_control(so, SIOCDIFADDR, (void *)&ifra,
796 				ifp, l);
797 		}
798 	    }
799 	}
800 
801 	return EOPNOTSUPP;	/*just for safety*/
802 }
803 
804 static int
805 in_ifaddrpref_ioctl(struct socket *so, u_long cmd, void *data,
806     struct ifnet *ifp)
807 {
808 	struct if_addrprefreq *ifap = (struct if_addrprefreq *)data;
809 	struct ifaddr *ifa;
810 	struct sockaddr *sa;
811 	struct in_ifaddr *ia = NULL; /* appease gcc -Wuninitialized */
812 	struct in_addr match;
813 	struct sockaddr_in *sin;
814 
815 	/* sanity checks */
816 	if (data == NULL || ifp == NULL) {
817 		panic("invalid argument to %s", __func__);
818 		/*NOTREACHED*/
819 	}
820 
821 	/* address must be specified on ADD and DELETE */
822 	sa = (struct sockaddr *)&ifap->ifap_addr;
823 	if (sa->sa_family != AF_INET)
824 		return EINVAL;
825 	if (sa->sa_len != sizeof(struct sockaddr_in))
826 		return EINVAL;
827 
828 	switch (cmd) {
829 	case SIOCSIFADDRPREF:
830 	case SIOCGIFADDRPREF:
831 		break;
832 	default:
833 		return EOPNOTSUPP;
834 	}
835 
836 	sin = (struct sockaddr_in *)&ifap->ifap_addr;
837 	match.s_addr = sin->sin_addr.s_addr;
838 
839 	IFADDR_FOREACH(ifa, ifp) {
840 		ia = (struct in_ifaddr *)ifa;
841 		if (ia->ia_addr.sin_family != AF_INET)
842 			continue;
843 		if (ia->ia_addr.sin_addr.s_addr == match.s_addr)
844 			break;
845 	}
846 	if (ifa == NULL)
847 		return EADDRNOTAVAIL;
848 
849 	switch (cmd) {
850 	case SIOCSIFADDRPREF:
851 		ifa->ifa_preference = ifap->ifap_preference;
852 		return 0;
853 	case SIOCGIFADDRPREF:
854 		/* fill in the if_laddrreq structure */
855 		(void)memcpy(&ifap->ifap_addr, &ia->ia_addr,
856 		    ia->ia_addr.sin_len);
857 		ifap->ifap_preference = ifa->ifa_preference;
858 		return 0;
859 	default:
860 		return EOPNOTSUPP;
861 	}
862 }
863 
864 /*
865  * Delete any existing route for an interface.
866  */
867 void
868 in_ifscrub(struct ifnet *ifp, struct in_ifaddr *ia)
869 {
870 
871 	in_scrubprefix(ia);
872 }
873 
874 /*
875  * Initialize an interface's internet address
876  * and routing table entry.
877  */
878 int
879 in_ifinit(struct ifnet *ifp, struct in_ifaddr *ia,
880     const struct sockaddr_in *sin, int scrub)
881 {
882 	u_int32_t i;
883 	struct sockaddr_in oldaddr;
884 	int s = splnet(), flags = RTF_UP, error;
885 
886 	if (sin == NULL)
887 		sin = &ia->ia_addr;
888 
889 	/*
890 	 * Set up new addresses.
891 	 */
892 	oldaddr = ia->ia_addr;
893 	if (ia->ia_addr.sin_family == AF_INET)
894 		LIST_REMOVE(ia, ia_hash);
895 	ia->ia_addr = *sin;
896 	LIST_INSERT_HEAD(&IN_IFADDR_HASH(ia->ia_addr.sin_addr.s_addr), ia, ia_hash);
897 
898 	/*
899 	 * Give the interface a chance to initialize
900 	 * if this is its first address,
901 	 * and to validate the address if necessary.
902 	 */
903 	if (ifp->if_ioctl &&
904 	    (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (void *)ia)))
905 		goto bad;
906 	splx(s);
907 	if (scrub) {
908 		ia->ia_ifa.ifa_addr = sintosa(&oldaddr);
909 		in_ifscrub(ifp, ia);
910 		ia->ia_ifa.ifa_addr = sintosa(&ia->ia_addr);
911 	}
912 
913 	i = ia->ia_addr.sin_addr.s_addr;
914 	if (IN_CLASSA(i))
915 		ia->ia_netmask = IN_CLASSA_NET;
916 	else if (IN_CLASSB(i))
917 		ia->ia_netmask = IN_CLASSB_NET;
918 	else
919 		ia->ia_netmask = IN_CLASSC_NET;
920 	/*
921 	 * The subnet mask usually includes at least the standard network part,
922 	 * but may may be smaller in the case of supernetting.
923 	 * If it is set, we believe it.
924 	 */
925 	if (ia->ia_subnetmask == 0) {
926 		ia->ia_subnetmask = ia->ia_netmask;
927 		ia->ia_sockmask.sin_addr.s_addr = ia->ia_subnetmask;
928 	} else
929 		ia->ia_netmask &= ia->ia_subnetmask;
930 
931 	ia->ia_net = i & ia->ia_netmask;
932 	ia->ia_subnet = i & ia->ia_subnetmask;
933 	in_socktrim(&ia->ia_sockmask);
934 	/* re-calculate the "in_maxmtu" value */
935 	in_setmaxmtu();
936 	/*
937 	 * Add route for the network.
938 	 */
939 	ia->ia_ifa.ifa_metric = ifp->if_metric;
940 	if (ifp->if_flags & IFF_BROADCAST) {
941 		ia->ia_broadaddr.sin_addr.s_addr =
942 			ia->ia_subnet | ~ia->ia_subnetmask;
943 		ia->ia_netbroadcast.s_addr =
944 			ia->ia_net | ~ia->ia_netmask;
945 	} else if (ifp->if_flags & IFF_LOOPBACK) {
946 		ia->ia_dstaddr = ia->ia_addr;
947 		flags |= RTF_HOST;
948 	} else if (ifp->if_flags & IFF_POINTOPOINT) {
949 		if (ia->ia_dstaddr.sin_family != AF_INET)
950 			return (0);
951 		flags |= RTF_HOST;
952 	}
953 	error = in_addprefix(ia, flags);
954 	/*
955 	 * If the interface supports multicast, join the "all hosts"
956 	 * multicast group on that interface.
957 	 */
958 	if ((ifp->if_flags & IFF_MULTICAST) != 0 && ia->ia_allhosts == NULL) {
959 		struct in_addr addr;
960 
961 		addr.s_addr = INADDR_ALLHOSTS_GROUP;
962 		ia->ia_allhosts = in_addmulti(&addr, ifp);
963 	}
964 	return (error);
965 bad:
966 	splx(s);
967 	LIST_REMOVE(ia, ia_hash);
968 	ia->ia_addr = oldaddr;
969 	if (ia->ia_addr.sin_family == AF_INET)
970 		LIST_INSERT_HEAD(&IN_IFADDR_HASH(ia->ia_addr.sin_addr.s_addr),
971 		    ia, ia_hash);
972 	return (error);
973 }
974 
975 #define rtinitflags(x) \
976 	((((x)->ia_ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) != 0) \
977 	    ? RTF_HOST : 0)
978 
979 /*
980  * add a route to prefix ("connected route" in cisco terminology).
981  * does nothing if there's some interface address with the same prefix already.
982  */
983 static int
984 in_addprefix(struct in_ifaddr *target, int flags)
985 {
986 	struct in_ifaddr *ia;
987 	struct in_addr prefix, mask, p;
988 	int error;
989 
990 	if ((flags & RTF_HOST) != 0)
991 		prefix = target->ia_dstaddr.sin_addr;
992 	else {
993 		prefix = target->ia_addr.sin_addr;
994 		mask = target->ia_sockmask.sin_addr;
995 		prefix.s_addr &= mask.s_addr;
996 	}
997 
998 	TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list) {
999 		if (rtinitflags(ia))
1000 			p = ia->ia_dstaddr.sin_addr;
1001 		else {
1002 			p = ia->ia_addr.sin_addr;
1003 			p.s_addr &= ia->ia_sockmask.sin_addr.s_addr;
1004 		}
1005 
1006 		if (prefix.s_addr != p.s_addr)
1007 			continue;
1008 
1009 		/*
1010 		 * if we got a matching prefix route inserted by other
1011 		 * interface address, we don't need to bother
1012 		 *
1013 		 * XXX RADIX_MPATH implications here? -dyoung
1014 		 */
1015 		if (ia->ia_flags & IFA_ROUTE)
1016 			return 0;
1017 	}
1018 
1019 	/*
1020 	 * noone seem to have prefix route.  insert it.
1021 	 */
1022 	error = rtinit(&target->ia_ifa, RTM_ADD, flags);
1023 	if (error == 0)
1024 		target->ia_flags |= IFA_ROUTE;
1025 	return error;
1026 }
1027 
1028 /*
1029  * remove a route to prefix ("connected route" in cisco terminology).
1030  * re-installs the route by using another interface address, if there's one
1031  * with the same prefix (otherwise we lose the route mistakenly).
1032  */
1033 static int
1034 in_scrubprefix(struct in_ifaddr *target)
1035 {
1036 	struct in_ifaddr *ia;
1037 	struct in_addr prefix, mask, p;
1038 	int error;
1039 
1040 	if ((target->ia_flags & IFA_ROUTE) == 0)
1041 		return 0;
1042 
1043 	if (rtinitflags(target))
1044 		prefix = target->ia_dstaddr.sin_addr;
1045 	else {
1046 		prefix = target->ia_addr.sin_addr;
1047 		mask = target->ia_sockmask.sin_addr;
1048 		prefix.s_addr &= mask.s_addr;
1049 	}
1050 
1051 	TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list) {
1052 		if (rtinitflags(ia))
1053 			p = ia->ia_dstaddr.sin_addr;
1054 		else {
1055 			p = ia->ia_addr.sin_addr;
1056 			p.s_addr &= ia->ia_sockmask.sin_addr.s_addr;
1057 		}
1058 
1059 		if (prefix.s_addr != p.s_addr)
1060 			continue;
1061 
1062 		/*
1063 		 * if we got a matching prefix route, move IFA_ROUTE to him
1064 		 */
1065 		if ((ia->ia_flags & IFA_ROUTE) == 0) {
1066 			rtinit(&target->ia_ifa, RTM_DELETE,
1067 			    rtinitflags(target));
1068 			target->ia_flags &= ~IFA_ROUTE;
1069 
1070 			error = rtinit(&ia->ia_ifa, RTM_ADD,
1071 			    rtinitflags(ia) | RTF_UP);
1072 			if (error == 0)
1073 				ia->ia_flags |= IFA_ROUTE;
1074 			return error;
1075 		}
1076 	}
1077 
1078 	/*
1079 	 * noone seem to have prefix route.  remove it.
1080 	 */
1081 	rtinit(&target->ia_ifa, RTM_DELETE, rtinitflags(target));
1082 	target->ia_flags &= ~IFA_ROUTE;
1083 	return 0;
1084 }
1085 
1086 #undef rtinitflags
1087 
1088 /*
1089  * Return 1 if the address might be a local broadcast address.
1090  */
1091 int
1092 in_broadcast(struct in_addr in, struct ifnet *ifp)
1093 {
1094 	struct ifaddr *ifa;
1095 
1096 	if (in.s_addr == INADDR_BROADCAST ||
1097 	    in_nullhost(in))
1098 		return 1;
1099 	if ((ifp->if_flags & IFF_BROADCAST) == 0)
1100 		return 0;
1101 	/*
1102 	 * Look through the list of addresses for a match
1103 	 * with a broadcast address.
1104 	 */
1105 #define ia (ifatoia(ifa))
1106 	IFADDR_FOREACH(ifa, ifp)
1107 		if (ifa->ifa_addr->sa_family == AF_INET &&
1108 		    !in_hosteq(in, ia->ia_addr.sin_addr) &&
1109 		    (in_hosteq(in, ia->ia_broadaddr.sin_addr) ||
1110 		     in_hosteq(in, ia->ia_netbroadcast) ||
1111 		     (hostzeroisbroadcast &&
1112 		      /*
1113 		       * Check for old-style (host 0) broadcast.
1114 		       */
1115 		      (in.s_addr == ia->ia_subnet ||
1116 		       in.s_addr == ia->ia_net))))
1117 			return 1;
1118 	return (0);
1119 #undef ia
1120 }
1121 
1122 /*
1123  * Add an address to the list of IP multicast addresses for a given interface.
1124  */
1125 struct in_multi *
1126 in_addmulti(struct in_addr *ap, struct ifnet *ifp)
1127 {
1128 	struct sockaddr_in sin;
1129 	struct in_multi *inm;
1130 	struct ifreq ifr;
1131 	int s = splsoftnet();
1132 
1133 	/*
1134 	 * See if address already in list.
1135 	 */
1136 	IN_LOOKUP_MULTI(*ap, ifp, inm);
1137 	if (inm != NULL) {
1138 		/*
1139 		 * Found it; just increment the reference count.
1140 		 */
1141 		++inm->inm_refcount;
1142 	} else {
1143 		/*
1144 		 * New address; allocate a new multicast record
1145 		 * and link it into the interface's multicast list.
1146 		 */
1147 		inm = pool_get(&inmulti_pool, PR_NOWAIT);
1148 		if (inm == NULL) {
1149 			splx(s);
1150 			return (NULL);
1151 		}
1152 		inm->inm_addr = *ap;
1153 		inm->inm_ifp = ifp;
1154 		inm->inm_refcount = 1;
1155 		LIST_INSERT_HEAD(
1156 		    &IN_MULTI_HASH(inm->inm_addr.s_addr, ifp),
1157 		    inm, inm_list);
1158 		/*
1159 		 * Ask the network driver to update its multicast reception
1160 		 * filter appropriately for the new address.
1161 		 */
1162 		sockaddr_in_init(&sin, ap, 0);
1163 		ifreq_setaddr(SIOCADDMULTI, &ifr, sintosa(&sin));
1164 		if ((ifp->if_ioctl == NULL) ||
1165 		    (*ifp->if_ioctl)(ifp, SIOCADDMULTI,(void *)&ifr) != 0) {
1166 			LIST_REMOVE(inm, inm_list);
1167 			pool_put(&inmulti_pool, inm);
1168 			splx(s);
1169 			return (NULL);
1170 		}
1171 		/*
1172 		 * Let IGMP know that we have joined a new IP multicast group.
1173 		 */
1174 		if (igmp_joingroup(inm) != 0) {
1175 			LIST_REMOVE(inm, inm_list);
1176 			pool_put(&inmulti_pool, inm);
1177 			splx(s);
1178 			return (NULL);
1179 		}
1180 		in_multientries++;
1181 	}
1182 	splx(s);
1183 	return (inm);
1184 }
1185 
1186 /*
1187  * Delete a multicast address record.
1188  */
1189 void
1190 in_delmulti(struct in_multi *inm)
1191 {
1192 	struct sockaddr_in sin;
1193 	struct ifreq ifr;
1194 	int s = splsoftnet();
1195 
1196 	if (--inm->inm_refcount == 0) {
1197 		/*
1198 		 * No remaining claims to this record; let IGMP know that
1199 		 * we are leaving the multicast group.
1200 		 */
1201 		igmp_leavegroup(inm);
1202 		/*
1203 		 * Unlink from list.
1204 		 */
1205 		LIST_REMOVE(inm, inm_list);
1206 		in_multientries--;
1207 		/*
1208 		 * Notify the network driver to update its multicast reception
1209 		 * filter.
1210 		 */
1211 		sockaddr_in_init(&sin, &inm->inm_addr, 0);
1212 		ifreq_setaddr(SIOCDELMULTI, &ifr, sintosa(&sin));
1213 		(*inm->inm_ifp->if_ioctl)(inm->inm_ifp, SIOCDELMULTI,
1214 							     (void *)&ifr);
1215 		pool_put(&inmulti_pool, inm);
1216 	}
1217 	splx(s);
1218 }
1219 #endif /* INET */
1220