xref: /netbsd-src/sys/netinet/in.c (revision c0179c282a5968435315a82f4128c61372c68fc3)
1 /*	$NetBSD: in.c,v 1.115 2006/11/16 01:33:45 christos 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 1.115 2006/11/16 01:33:45 christos 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, caddr_t,
148 	struct ifnet *, struct lwp *);
149 
150 static int in_ifaddrpref_ioctl(struct socket *, u_long, caddr_t,
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 < 8; y++) {
292 			if ((p[x] & (0x80 >> y)) == 0)
293 				break;
294 		}
295 	}
296 	return x * 8 + 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 / 8; i++)
308 		p[i] = 0xff;
309 	if (len % 8)
310 		p[i] = (0xff00 >> (len % 8)) & 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, caddr_t 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)
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)
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 == 0)
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((caddr_t)ia, sizeof *ia);
409 			TAILQ_INSERT_TAIL(&in_ifaddrhead, ia, ia_list);
410 			IFAREF(&ia->ia_ifa);
411 			TAILQ_INSERT_TAIL(&ifp->if_addrlist, &ia->ia_ifa,
412 			    ifa_list);
413 			IFAREF(&ia->ia_ifa);
414 			ia->ia_ifa.ifa_addr = sintosa(&ia->ia_addr);
415 			ia->ia_ifa.ifa_dstaddr = sintosa(&ia->ia_dstaddr);
416 			ia->ia_ifa.ifa_netmask = sintosa(&ia->ia_sockmask);
417 #ifdef IPSELSRC
418 			ia->ia_ifa.ifa_getifa = in_getifa;
419 #else /* IPSELSRC */
420 			ia->ia_ifa.ifa_getifa = NULL;
421 #endif /* IPSELSRC */
422 			ia->ia_sockmask.sin_len = 8;
423 			if (ifp->if_flags & IFF_BROADCAST) {
424 				ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr);
425 				ia->ia_broadaddr.sin_family = AF_INET;
426 			}
427 			ia->ia_ifp = ifp;
428 			LIST_INIT(&ia->ia_multiaddrs);
429 			newifaddr = 1;
430 		}
431 		break;
432 
433 	case SIOCSIFBRDADDR:
434 		if (l == NULL)
435 			return (EPERM);
436 		if (kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE,
437 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
438 		    NULL) != 0)
439 			return (EPERM);
440 		/* FALLTHROUGH */
441 
442 	case SIOCGIFADDR:
443 	case SIOCGIFNETMASK:
444 	case SIOCGIFDSTADDR:
445 	case SIOCGIFBRDADDR:
446 		if (ia == 0)
447 			return (EADDRNOTAVAIL);
448 		break;
449 	}
450 	error = 0;
451 	switch (cmd) {
452 
453 	case SIOCGIFADDR:
454 		*satosin(&ifr->ifr_addr) = ia->ia_addr;
455 		break;
456 
457 	case SIOCGIFBRDADDR:
458 		if ((ifp->if_flags & IFF_BROADCAST) == 0)
459 			return (EINVAL);
460 		*satosin(&ifr->ifr_dstaddr) = ia->ia_broadaddr;
461 		break;
462 
463 	case SIOCGIFDSTADDR:
464 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
465 			return (EINVAL);
466 		*satosin(&ifr->ifr_dstaddr) = ia->ia_dstaddr;
467 		break;
468 
469 	case SIOCGIFNETMASK:
470 		*satosin(&ifr->ifr_addr) = ia->ia_sockmask;
471 		break;
472 
473 	case SIOCSIFDSTADDR:
474 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
475 			return (EINVAL);
476 		oldaddr = ia->ia_dstaddr;
477 		ia->ia_dstaddr = *satosin(&ifr->ifr_dstaddr);
478 		if (ifp->if_ioctl && (error = (*ifp->if_ioctl)
479 					(ifp, SIOCSIFDSTADDR, (caddr_t)ia))) {
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), (int)RTM_DELETE, RTF_HOST);
486 			ia->ia_ifa.ifa_dstaddr = sintosa(&ia->ia_dstaddr);
487 			rtinit(&(ia->ia_ifa), (int)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 = *satosin(&ifr->ifr_broadaddr);
495 		break;
496 
497 	case SIOCSIFADDR:
498 		error = in_ifinit(ifp, ia, satosin(&ifr->ifr_addr), 1);
499 #ifdef PFIL_HOOKS
500 		if (!error)
501 			(void)pfil_run_hooks(&if_pfil,
502 			    (struct mbuf **)SIOCSIFADDR, ifp, PFIL_IFADDR);
503 #endif
504 		break;
505 
506 	case SIOCSIFNETMASK:
507 		in_ifscrub(ifp, ia);
508 		ia->ia_sockmask = *satosin(&ifr->ifr_addr);
509 		ia->ia_subnetmask = ia->ia_sockmask.sin_addr.s_addr;
510 		error = in_ifinit(ifp, ia, NULL, 0);
511 		break;
512 
513 	case SIOCAIFADDR:
514 		maskIsNew = 0;
515 		hostIsNew = 1;
516 		if (ia->ia_addr.sin_family == AF_INET) {
517 			if (ifra->ifra_addr.sin_len == 0) {
518 				ifra->ifra_addr = ia->ia_addr;
519 				hostIsNew = 0;
520 			} else if (in_hosteq(ia->ia_addr.sin_addr, ifra->ifra_addr.sin_addr))
521 				hostIsNew = 0;
522 		}
523 		if (ifra->ifra_mask.sin_len) {
524 			in_ifscrub(ifp, ia);
525 			ia->ia_sockmask = ifra->ifra_mask;
526 			ia->ia_subnetmask = ia->ia_sockmask.sin_addr.s_addr;
527 			maskIsNew = 1;
528 		}
529 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
530 		    (ifra->ifra_dstaddr.sin_family == AF_INET)) {
531 			in_ifscrub(ifp, ia);
532 			ia->ia_dstaddr = ifra->ifra_dstaddr;
533 			maskIsNew  = 1; /* We lie; but the effect's the same */
534 		}
535 		if (ifra->ifra_addr.sin_family == AF_INET &&
536 		    (hostIsNew || maskIsNew)) {
537 			error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
538 		}
539 		if ((ifp->if_flags & IFF_BROADCAST) &&
540 		    (ifra->ifra_broadaddr.sin_family == AF_INET))
541 			ia->ia_broadaddr = ifra->ifra_broadaddr;
542 #ifdef PFIL_HOOKS
543 		if (!error)
544 			(void)pfil_run_hooks(&if_pfil,
545 			    (struct mbuf **)SIOCAIFADDR, ifp, PFIL_IFADDR);
546 #endif
547 		break;
548 
549 	case SIOCGIFALIAS:
550 		ifra->ifra_mask = ia->ia_sockmask;
551 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
552 		    (ia->ia_dstaddr.sin_family == AF_INET))
553 			ifra->ifra_dstaddr = ia->ia_dstaddr;
554 		else if ((ifp->if_flags & IFF_BROADCAST) &&
555 		    (ia->ia_broadaddr.sin_family == AF_INET))
556 			ifra->ifra_broadaddr = ia->ia_broadaddr;
557 		else
558 			bzero(&ifra->ifra_broadaddr,
559 			      sizeof(ifra->ifra_broadaddr));
560 		break;
561 
562 	case SIOCDIFADDR:
563 		in_purgeaddr(&ia->ia_ifa, ifp);
564 #ifdef PFIL_HOOKS
565 		(void)pfil_run_hooks(&if_pfil, (struct mbuf **)SIOCDIFADDR,
566 		    ifp, PFIL_IFADDR);
567 #endif
568 		break;
569 
570 #ifdef MROUTING
571 	case SIOCGETVIFCNT:
572 	case SIOCGETSGCNT:
573 		error = mrt_ioctl(so, cmd, data);
574 		break;
575 #endif /* MROUTING */
576 
577 	default:
578 		if (ifp == 0 || ifp->if_ioctl == 0)
579 			return (EOPNOTSUPP);
580 		error = (*ifp->if_ioctl)(ifp, cmd, data);
581 		in_setmaxmtu();
582 		break;
583 	}
584 
585 	if (error && newifaddr) {
586 		KASSERT(ia != NULL);
587 		in_purgeaddr(&ia->ia_ifa, ifp);
588 	}
589 
590 	return error;
591 }
592 
593 void
594 in_purgeaddr(struct ifaddr *ifa, struct ifnet *ifp)
595 {
596 	struct in_ifaddr *ia = (void *) ifa;
597 
598 	in_ifscrub(ifp, ia);
599 	LIST_REMOVE(ia, ia_hash);
600 	TAILQ_REMOVE(&ifp->if_addrlist, &ia->ia_ifa, ifa_list);
601 	IFAFREE(&ia->ia_ifa);
602 	TAILQ_REMOVE(&in_ifaddrhead, ia, ia_list);
603 	if (ia->ia_allhosts != NULL)
604 		in_delmulti(ia->ia_allhosts);
605 	IFAFREE(&ia->ia_ifa);
606 	in_setmaxmtu();
607 }
608 
609 void
610 in_purgeif(struct ifnet *ifp)		/* MUST be called at splsoftnet() */
611 {
612 	struct ifaddr *ifa, *nifa;
613 
614 	for (ifa = TAILQ_FIRST(&ifp->if_addrlist); ifa != NULL; ifa = nifa) {
615 		nifa = TAILQ_NEXT(ifa, ifa_list);
616 		if (ifa->ifa_addr->sa_family != AF_INET)
617 			continue;
618 		in_purgeaddr(ifa, ifp);
619 	}
620 
621 	igmp_purgeif(ifp);		/* manipulates pools */
622 #ifdef MROUTING
623 	ip_mrouter_detach(ifp);
624 #endif
625 }
626 
627 /*
628  * SIOC[GAD]LIFADDR.
629  *	SIOCGLIFADDR: get first address. (???)
630  *	SIOCGLIFADDR with IFLR_PREFIX:
631  *		get first address that matches the specified prefix.
632  *	SIOCALIFADDR: add the specified address.
633  *	SIOCALIFADDR with IFLR_PREFIX:
634  *		EINVAL since we can't deduce hostid part of the address.
635  *	SIOCDLIFADDR: delete the specified address.
636  *	SIOCDLIFADDR with IFLR_PREFIX:
637  *		delete the first address that matches the specified prefix.
638  * return values:
639  *	EINVAL on invalid parameters
640  *	EADDRNOTAVAIL on prefix match failed/specified address not found
641  *	other values may be returned from in_ioctl()
642  */
643 static int
644 in_lifaddr_ioctl(struct socket *so, u_long cmd, caddr_t data,
645     struct ifnet *ifp, struct lwp *l)
646 {
647 	struct if_laddrreq *iflr = (struct if_laddrreq *)data;
648 	struct ifaddr *ifa;
649 	struct sockaddr *sa;
650 
651 	/* sanity checks */
652 	if (!data || !ifp) {
653 		panic("invalid argument to in_lifaddr_ioctl");
654 		/*NOTRECHED*/
655 	}
656 
657 	switch (cmd) {
658 	case SIOCGLIFADDR:
659 		/* address must be specified on GET with IFLR_PREFIX */
660 		if ((iflr->flags & IFLR_PREFIX) == 0)
661 			break;
662 		/*FALLTHROUGH*/
663 	case SIOCALIFADDR:
664 	case SIOCDLIFADDR:
665 		/* address must be specified on ADD and DELETE */
666 		sa = (struct sockaddr *)&iflr->addr;
667 		if (sa->sa_family != AF_INET)
668 			return EINVAL;
669 		if (sa->sa_len != sizeof(struct sockaddr_in))
670 			return EINVAL;
671 		/* XXX need improvement */
672 		sa = (struct sockaddr *)&iflr->dstaddr;
673 		if (sa->sa_family
674 		 && sa->sa_family != AF_INET)
675 			return EINVAL;
676 		if (sa->sa_len && sa->sa_len != sizeof(struct sockaddr_in))
677 			return EINVAL;
678 		break;
679 	default: /*shouldn't happen*/
680 #if 0
681 		panic("invalid cmd to in_lifaddr_ioctl");
682 		/*NOTREACHED*/
683 #else
684 		return EOPNOTSUPP;
685 #endif
686 	}
687 	if (sizeof(struct in_addr) * 8 < iflr->prefixlen)
688 		return EINVAL;
689 
690 	switch (cmd) {
691 	case SIOCALIFADDR:
692 	    {
693 		struct in_aliasreq ifra;
694 
695 		if (iflr->flags & IFLR_PREFIX)
696 			return EINVAL;
697 
698 		/* copy args to in_aliasreq, perform ioctl(SIOCAIFADDR). */
699 		bzero(&ifra, sizeof(ifra));
700 		bcopy(iflr->iflr_name, ifra.ifra_name,
701 			sizeof(ifra.ifra_name));
702 
703 		bcopy(&iflr->addr, &ifra.ifra_addr,
704 			((struct sockaddr *)&iflr->addr)->sa_len);
705 
706 		if (((struct sockaddr *)&iflr->dstaddr)->sa_family) {	/*XXX*/
707 			bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
708 				((struct sockaddr *)&iflr->dstaddr)->sa_len);
709 		}
710 
711 		ifra.ifra_mask.sin_family = AF_INET;
712 		ifra.ifra_mask.sin_len = sizeof(struct sockaddr_in);
713 		in_len2mask(&ifra.ifra_mask.sin_addr, iflr->prefixlen);
714 
715 		return in_control(so, SIOCAIFADDR, (caddr_t)&ifra, ifp, l);
716 	    }
717 	case SIOCGLIFADDR:
718 	case SIOCDLIFADDR:
719 	    {
720 		struct in_ifaddr *ia;
721 		struct in_addr mask, candidate, match;
722 		struct sockaddr_in *sin;
723 		int cmp;
724 
725 		bzero(&mask, sizeof(mask));
726 		bzero(&match, sizeof(match));	/* XXX gcc */
727 		if (iflr->flags & IFLR_PREFIX) {
728 			/* lookup a prefix rather than address. */
729 			in_len2mask(&mask, iflr->prefixlen);
730 
731 			sin = (struct sockaddr_in *)&iflr->addr;
732 			match.s_addr = sin->sin_addr.s_addr;
733 			match.s_addr &= mask.s_addr;
734 
735 			/* if you set extra bits, that's wrong */
736 			if (match.s_addr != sin->sin_addr.s_addr)
737 				return EINVAL;
738 
739 			cmp = 1;
740 		} else {
741 			if (cmd == SIOCGLIFADDR) {
742 				/* on getting an address, take the 1st match */
743 				cmp = 0;	/*XXX*/
744 			} else {
745 				/* on deleting an address, do exact match */
746 				in_len2mask(&mask, 32);
747 				sin = (struct sockaddr_in *)&iflr->addr;
748 				match.s_addr = sin->sin_addr.s_addr;
749 
750 				cmp = 1;
751 			}
752 		}
753 
754 		IFADDR_FOREACH(ifa, ifp) {
755 			if (ifa->ifa_addr->sa_family != AF_INET)
756 				continue;
757 			if (!cmp)
758 				break;
759 			candidate.s_addr = ((struct sockaddr_in *)&ifa->ifa_addr)->sin_addr.s_addr;
760 			candidate.s_addr &= mask.s_addr;
761 			if (candidate.s_addr == match.s_addr)
762 				break;
763 		}
764 		if (!ifa)
765 			return EADDRNOTAVAIL;
766 		ia = (struct in_ifaddr *)ifa;
767 
768 		if (cmd == SIOCGLIFADDR) {
769 			/* fill in the if_laddrreq structure */
770 			bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin_len);
771 
772 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
773 				bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
774 					ia->ia_dstaddr.sin_len);
775 			} else
776 				bzero(&iflr->dstaddr, sizeof(iflr->dstaddr));
777 
778 			iflr->prefixlen =
779 				in_mask2len(&ia->ia_sockmask.sin_addr);
780 
781 			iflr->flags = 0;	/*XXX*/
782 
783 			return 0;
784 		} else {
785 			struct in_aliasreq ifra;
786 
787 			/* fill in_aliasreq and do ioctl(SIOCDIFADDR) */
788 			bzero(&ifra, sizeof(ifra));
789 			bcopy(iflr->iflr_name, ifra.ifra_name,
790 				sizeof(ifra.ifra_name));
791 
792 			bcopy(&ia->ia_addr, &ifra.ifra_addr,
793 				ia->ia_addr.sin_len);
794 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
795 				bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
796 					ia->ia_dstaddr.sin_len);
797 			}
798 			bcopy(&ia->ia_sockmask, &ifra.ifra_dstaddr,
799 				ia->ia_sockmask.sin_len);
800 
801 			return in_control(so, SIOCDIFADDR, (caddr_t)&ifra,
802 				ifp, l);
803 		}
804 	    }
805 	}
806 
807 	return EOPNOTSUPP;	/*just for safety*/
808 }
809 
810 static int
811 in_ifaddrpref_ioctl(struct socket *so, u_long cmd, caddr_t data,
812     struct ifnet *ifp)
813 {
814 	struct if_addrprefreq *ifap = (struct if_addrprefreq *)data;
815 	struct ifaddr *ifa;
816 	struct sockaddr *sa;
817 	struct in_ifaddr *ia = NULL; /* appease gcc -Wuninitialized */
818 	struct in_addr match;
819 	struct sockaddr_in *sin;
820 
821 	/* sanity checks */
822 	if (data == NULL || ifp == NULL) {
823 		panic("invalid argument to %s", __func__);
824 		/*NOTREACHED*/
825 	}
826 
827 	/* address must be specified on ADD and DELETE */
828 	sa = (struct sockaddr *)&ifap->ifap_addr;
829 	if (sa->sa_family != AF_INET)
830 		return EINVAL;
831 	if (sa->sa_len != sizeof(struct sockaddr_in))
832 		return EINVAL;
833 
834 	switch (cmd) {
835 	case SIOCSIFADDRPREF:
836 	case SIOCGIFADDRPREF:
837 		break;
838 	default:
839 		return EOPNOTSUPP;
840 	}
841 
842 	sin = (struct sockaddr_in *)&ifap->ifap_addr;
843 	match.s_addr = sin->sin_addr.s_addr;
844 
845 	IFADDR_FOREACH(ifa, ifp) {
846 		ia = (struct in_ifaddr *)ifa;
847 		if (ia->ia_addr.sin_family != AF_INET)
848 			continue;
849 		if (ia->ia_addr.sin_addr.s_addr == match.s_addr)
850 			break;
851 	}
852 	if (ifa == NULL)
853 		return EADDRNOTAVAIL;
854 
855 	switch (cmd) {
856 	case SIOCSIFADDRPREF:
857 		ifa->ifa_preference = ifap->ifap_preference;
858 		return 0;
859 	case SIOCGIFADDRPREF:
860 		/* fill in the if_laddrreq structure */
861 		(void)memcpy(&ifap->ifap_addr, &ia->ia_addr,
862 		    ia->ia_addr.sin_len);
863 		ifap->ifap_preference = ifa->ifa_preference;
864 		return 0;
865 	default:
866 		return EOPNOTSUPP;
867 	}
868 }
869 
870 /*
871  * Delete any existing route for an interface.
872  */
873 void
874 in_ifscrub(struct ifnet *ifp, struct in_ifaddr *ia)
875 {
876 
877 	in_scrubprefix(ia);
878 }
879 
880 /*
881  * Initialize an interface's internet address
882  * and routing table entry.
883  */
884 int
885 in_ifinit(struct ifnet *ifp, struct in_ifaddr *ia,
886     struct sockaddr_in *sin, int scrub)
887 {
888 	u_int32_t i;
889 	struct sockaddr_in oldaddr;
890 	int s = splnet(), flags = RTF_UP, error;
891 
892 	if (!sin)
893 		sin = &ia->ia_addr;
894 
895 	/*
896 	 * Set up new addresses.
897 	 */
898 	oldaddr = ia->ia_addr;
899 	if (ia->ia_addr.sin_family == AF_INET)
900 		LIST_REMOVE(ia, ia_hash);
901 	ia->ia_addr = *sin;
902 	LIST_INSERT_HEAD(&IN_IFADDR_HASH(ia->ia_addr.sin_addr.s_addr), ia, ia_hash);
903 
904 	/*
905 	 * Give the interface a chance to initialize
906 	 * if this is its first address,
907 	 * and to validate the address if necessary.
908 	 */
909 	if (ifp->if_ioctl &&
910 	    (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia)))
911 		goto bad;
912 	splx(s);
913 	if (scrub) {
914 		ia->ia_ifa.ifa_addr = sintosa(&oldaddr);
915 		in_ifscrub(ifp, ia);
916 		ia->ia_ifa.ifa_addr = sintosa(&ia->ia_addr);
917 	}
918 
919 	i = ia->ia_addr.sin_addr.s_addr;
920 	if (IN_CLASSA(i))
921 		ia->ia_netmask = IN_CLASSA_NET;
922 	else if (IN_CLASSB(i))
923 		ia->ia_netmask = IN_CLASSB_NET;
924 	else
925 		ia->ia_netmask = IN_CLASSC_NET;
926 	/*
927 	 * The subnet mask usually includes at least the standard network part,
928 	 * but may may be smaller in the case of supernetting.
929 	 * If it is set, we believe it.
930 	 */
931 	if (ia->ia_subnetmask == 0) {
932 		ia->ia_subnetmask = ia->ia_netmask;
933 		ia->ia_sockmask.sin_addr.s_addr = ia->ia_subnetmask;
934 	} else
935 		ia->ia_netmask &= ia->ia_subnetmask;
936 
937 	ia->ia_net = i & ia->ia_netmask;
938 	ia->ia_subnet = i & ia->ia_subnetmask;
939 	in_socktrim(&ia->ia_sockmask);
940 	/* re-calculate the "in_maxmtu" value */
941 	in_setmaxmtu();
942 	/*
943 	 * Add route for the network.
944 	 */
945 	ia->ia_ifa.ifa_metric = ifp->if_metric;
946 	if (ifp->if_flags & IFF_BROADCAST) {
947 		ia->ia_broadaddr.sin_addr.s_addr =
948 			ia->ia_subnet | ~ia->ia_subnetmask;
949 		ia->ia_netbroadcast.s_addr =
950 			ia->ia_net | ~ia->ia_netmask;
951 	} else if (ifp->if_flags & IFF_LOOPBACK) {
952 		ia->ia_dstaddr = ia->ia_addr;
953 		flags |= RTF_HOST;
954 	} else if (ifp->if_flags & IFF_POINTOPOINT) {
955 		if (ia->ia_dstaddr.sin_family != AF_INET)
956 			return (0);
957 		flags |= RTF_HOST;
958 	}
959 	error = in_addprefix(ia, flags);
960 	/*
961 	 * If the interface supports multicast, join the "all hosts"
962 	 * multicast group on that interface.
963 	 */
964 	if ((ifp->if_flags & IFF_MULTICAST) != 0 && ia->ia_allhosts == NULL) {
965 		struct in_addr addr;
966 
967 		addr.s_addr = INADDR_ALLHOSTS_GROUP;
968 		ia->ia_allhosts = in_addmulti(&addr, ifp);
969 	}
970 	return (error);
971 bad:
972 	splx(s);
973 	LIST_REMOVE(ia, ia_hash);
974 	ia->ia_addr = oldaddr;
975 	if (ia->ia_addr.sin_family == AF_INET)
976 		LIST_INSERT_HEAD(&IN_IFADDR_HASH(ia->ia_addr.sin_addr.s_addr),
977 		    ia, ia_hash);
978 	return (error);
979 }
980 
981 #define rtinitflags(x) \
982 	((((x)->ia_ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) != 0) \
983 	    ? RTF_HOST : 0)
984 
985 /*
986  * add a route to prefix ("connected route" in cisco terminology).
987  * does nothing if there's some interface address with the same prefix already.
988  */
989 static int
990 in_addprefix(struct in_ifaddr *target, int flags)
991 {
992 	struct in_ifaddr *ia;
993 	struct in_addr prefix, mask, p;
994 	int error;
995 
996 	if ((flags & RTF_HOST) != 0)
997 		prefix = target->ia_dstaddr.sin_addr;
998 	else {
999 		prefix = target->ia_addr.sin_addr;
1000 		mask = target->ia_sockmask.sin_addr;
1001 		prefix.s_addr &= mask.s_addr;
1002 	}
1003 
1004 	TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list) {
1005 		if (rtinitflags(ia))
1006 			p = ia->ia_dstaddr.sin_addr;
1007 		else {
1008 			p = ia->ia_addr.sin_addr;
1009 			p.s_addr &= ia->ia_sockmask.sin_addr.s_addr;
1010 		}
1011 
1012 		if (prefix.s_addr != p.s_addr)
1013 			continue;
1014 
1015 		/*
1016 		 * if we got a matching prefix route inserted by other
1017 		 * interface address, we don't need to bother
1018 		 *
1019 		 * XXX RADIX_MPATH implications here? -dyoung
1020 		 */
1021 		if (ia->ia_flags & IFA_ROUTE)
1022 			return 0;
1023 	}
1024 
1025 	/*
1026 	 * noone seem to have prefix route.  insert it.
1027 	 */
1028 	error = rtinit(&target->ia_ifa, (int)RTM_ADD, flags);
1029 	if (!error)
1030 		target->ia_flags |= IFA_ROUTE;
1031 	return error;
1032 }
1033 
1034 /*
1035  * remove a route to prefix ("connected route" in cisco terminology).
1036  * re-installs the route by using another interface address, if there's one
1037  * with the same prefix (otherwise we lose the route mistakenly).
1038  */
1039 static int
1040 in_scrubprefix(struct in_ifaddr *target)
1041 {
1042 	struct in_ifaddr *ia;
1043 	struct in_addr prefix, mask, p;
1044 	int error;
1045 
1046 	if ((target->ia_flags & IFA_ROUTE) == 0)
1047 		return 0;
1048 
1049 	if (rtinitflags(target))
1050 		prefix = target->ia_dstaddr.sin_addr;
1051 	else {
1052 		prefix = target->ia_addr.sin_addr;
1053 		mask = target->ia_sockmask.sin_addr;
1054 		prefix.s_addr &= mask.s_addr;
1055 	}
1056 
1057 	TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list) {
1058 		if (rtinitflags(ia))
1059 			p = ia->ia_dstaddr.sin_addr;
1060 		else {
1061 			p = ia->ia_addr.sin_addr;
1062 			p.s_addr &= ia->ia_sockmask.sin_addr.s_addr;
1063 		}
1064 
1065 		if (prefix.s_addr != p.s_addr)
1066 			continue;
1067 
1068 		/*
1069 		 * if we got a matching prefix route, move IFA_ROUTE to him
1070 		 */
1071 		if ((ia->ia_flags & IFA_ROUTE) == 0) {
1072 			rtinit(&(target->ia_ifa), (int)RTM_DELETE,
1073 			    rtinitflags(target));
1074 			target->ia_flags &= ~IFA_ROUTE;
1075 
1076 			error = rtinit(&ia->ia_ifa, (int)RTM_ADD,
1077 			    rtinitflags(ia) | RTF_UP);
1078 			if (error == 0)
1079 				ia->ia_flags |= IFA_ROUTE;
1080 			return error;
1081 		}
1082 	}
1083 
1084 	/*
1085 	 * noone seem to have prefix route.  remove it.
1086 	 */
1087 	rtinit(&(target->ia_ifa), (int)RTM_DELETE, rtinitflags(target));
1088 	target->ia_flags &= ~IFA_ROUTE;
1089 	return 0;
1090 }
1091 
1092 #undef rtinitflags
1093 
1094 /*
1095  * Return 1 if the address might be a local broadcast address.
1096  */
1097 int
1098 in_broadcast(struct in_addr in, struct ifnet *ifp)
1099 {
1100 	struct ifaddr *ifa;
1101 
1102 	if (in.s_addr == INADDR_BROADCAST ||
1103 	    in_nullhost(in))
1104 		return 1;
1105 	if ((ifp->if_flags & IFF_BROADCAST) == 0)
1106 		return 0;
1107 	/*
1108 	 * Look through the list of addresses for a match
1109 	 * with a broadcast address.
1110 	 */
1111 #define ia (ifatoia(ifa))
1112 	IFADDR_FOREACH(ifa, ifp)
1113 		if (ifa->ifa_addr->sa_family == AF_INET &&
1114 		    !in_hosteq(in, ia->ia_addr.sin_addr) &&
1115 		    (in_hosteq(in, ia->ia_broadaddr.sin_addr) ||
1116 		     in_hosteq(in, ia->ia_netbroadcast) ||
1117 		     (hostzeroisbroadcast &&
1118 		      /*
1119 		       * Check for old-style (host 0) broadcast.
1120 		       */
1121 		      (in.s_addr == ia->ia_subnet ||
1122 		       in.s_addr == ia->ia_net))))
1123 			return 1;
1124 	return (0);
1125 #undef ia
1126 }
1127 
1128 /*
1129  * Add an address to the list of IP multicast addresses for a given interface.
1130  */
1131 struct in_multi *
1132 in_addmulti(struct in_addr *ap, struct ifnet *ifp)
1133 {
1134 	struct in_multi *inm;
1135 	struct ifreq ifr;
1136 	int s = splsoftnet();
1137 
1138 	/*
1139 	 * See if address already in list.
1140 	 */
1141 	IN_LOOKUP_MULTI(*ap, ifp, inm);
1142 	if (inm != NULL) {
1143 		/*
1144 		 * Found it; just increment the reference count.
1145 		 */
1146 		++inm->inm_refcount;
1147 	} else {
1148 		/*
1149 		 * New address; allocate a new multicast record
1150 		 * and link it into the interface's multicast list.
1151 		 */
1152 		inm = pool_get(&inmulti_pool, PR_NOWAIT);
1153 		if (inm == NULL) {
1154 			splx(s);
1155 			return (NULL);
1156 		}
1157 		inm->inm_addr = *ap;
1158 		inm->inm_ifp = ifp;
1159 		inm->inm_refcount = 1;
1160 		LIST_INSERT_HEAD(
1161 		    &IN_MULTI_HASH(inm->inm_addr.s_addr, ifp),
1162 		    inm, inm_list);
1163 		/*
1164 		 * Ask the network driver to update its multicast reception
1165 		 * filter appropriately for the new address.
1166 		 */
1167 		satosin(&ifr.ifr_addr)->sin_len = sizeof(struct sockaddr_in);
1168 		satosin(&ifr.ifr_addr)->sin_family = AF_INET;
1169 		satosin(&ifr.ifr_addr)->sin_addr = *ap;
1170 		if ((ifp->if_ioctl == NULL) ||
1171 		    (*ifp->if_ioctl)(ifp, SIOCADDMULTI,(caddr_t)&ifr) != 0) {
1172 			LIST_REMOVE(inm, inm_list);
1173 			pool_put(&inmulti_pool, inm);
1174 			splx(s);
1175 			return (NULL);
1176 		}
1177 		/*
1178 		 * Let IGMP know that we have joined a new IP multicast group.
1179 		 */
1180 		if (igmp_joingroup(inm) != 0) {
1181 			LIST_REMOVE(inm, inm_list);
1182 			pool_put(&inmulti_pool, inm);
1183 			splx(s);
1184 			return (NULL);
1185 		}
1186 		in_multientries++;
1187 	}
1188 	splx(s);
1189 	return (inm);
1190 }
1191 
1192 /*
1193  * Delete a multicast address record.
1194  */
1195 void
1196 in_delmulti(struct in_multi *inm)
1197 {
1198 	struct ifreq ifr;
1199 	int s = splsoftnet();
1200 
1201 	if (--inm->inm_refcount == 0) {
1202 		/*
1203 		 * No remaining claims to this record; let IGMP know that
1204 		 * we are leaving the multicast group.
1205 		 */
1206 		igmp_leavegroup(inm);
1207 		/*
1208 		 * Unlink from list.
1209 		 */
1210 		LIST_REMOVE(inm, inm_list);
1211 		in_multientries--;
1212 		/*
1213 		 * Notify the network driver to update its multicast reception
1214 		 * filter.
1215 		 */
1216 		satosin(&ifr.ifr_addr)->sin_family = AF_INET;
1217 		satosin(&ifr.ifr_addr)->sin_addr = inm->inm_addr;
1218 		(*inm->inm_ifp->if_ioctl)(inm->inm_ifp, SIOCDELMULTI,
1219 							     (caddr_t)&ifr);
1220 		pool_put(&inmulti_pool, inm);
1221 	}
1222 	splx(s);
1223 }
1224 #endif /* INET */
1225