xref: /netbsd-src/sys/netinet/in.c (revision cd22f25e6f6d1cc1f197fe8c5468a80f51d1c4e1)
1 /*	$NetBSD: in.c,v 1.125 2008/04/28 20:24:09 martin 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  *
49  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
50  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
51  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
52  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
53  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
54  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
55  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
56  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
57  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
58  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
59  * POSSIBILITY OF SUCH DAMAGE.
60  */
61 
62 /*
63  * Copyright (c) 1982, 1986, 1991, 1993
64  *	The Regents of the University of California.  All rights reserved.
65  *
66  * Redistribution and use in source and binary forms, with or without
67  * modification, are permitted provided that the following conditions
68  * are met:
69  * 1. Redistributions of source code must retain the above copyright
70  *    notice, this list of conditions and the following disclaimer.
71  * 2. Redistributions in binary form must reproduce the above copyright
72  *    notice, this list of conditions and the following disclaimer in the
73  *    documentation and/or other materials provided with the distribution.
74  * 3. Neither the name of the University nor the names of its contributors
75  *    may be used to endorse or promote products derived from this software
76  *    without specific prior written permission.
77  *
78  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
79  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
80  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
81  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
82  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
83  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
84  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
85  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
86  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
87  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
88  * SUCH DAMAGE.
89  *
90  *	@(#)in.c	8.4 (Berkeley) 1/9/95
91  */
92 
93 #include <sys/cdefs.h>
94 __KERNEL_RCSID(0, "$NetBSD: in.c,v 1.125 2008/04/28 20:24:09 martin Exp $");
95 
96 #include "opt_inet.h"
97 #include "opt_inet_conf.h"
98 #include "opt_mrouting.h"
99 #include "opt_pfil_hooks.h"
100 
101 #include <sys/param.h>
102 #include <sys/ioctl.h>
103 #include <sys/errno.h>
104 #include <sys/malloc.h>
105 #include <sys/socket.h>
106 #include <sys/socketvar.h>
107 #include <sys/sysctl.h>
108 #include <sys/systm.h>
109 #include <sys/proc.h>
110 #include <sys/syslog.h>
111 #include <sys/kauth.h>
112 
113 #include <net/if.h>
114 #include <net/route.h>
115 
116 #include <net/if_ether.h>
117 
118 #include <netinet/in_systm.h>
119 #include <netinet/in.h>
120 #include <netinet/in_var.h>
121 #include <netinet/ip.h>
122 #include <netinet/ip_var.h>
123 #include <netinet/in_ifattach.h>
124 #include <netinet/in_pcb.h>
125 #include <netinet/if_inarp.h>
126 #include <netinet/ip_mroute.h>
127 #include <netinet/igmp_var.h>
128 
129 #ifdef IPSELSRC
130 #include <netinet/in_selsrc.h>
131 #endif
132 
133 #ifdef PFIL_HOOKS
134 #include <net/pfil.h>
135 #endif
136 
137 #ifdef INET
138 static u_int in_mask2len(struct in_addr *);
139 static void in_len2mask(struct in_addr *, u_int);
140 static int in_lifaddr_ioctl(struct socket *, u_long, void *,
141 	struct ifnet *, struct lwp *);
142 
143 static int in_ifaddrpref_ioctl(struct socket *, u_long, void *,
144 	struct ifnet *);
145 static int in_addprefix(struct in_ifaddr *, int);
146 static int in_scrubprefix(struct in_ifaddr *);
147 
148 #ifndef SUBNETSARELOCAL
149 #define	SUBNETSARELOCAL	1
150 #endif
151 
152 #ifndef HOSTZEROBROADCAST
153 #define HOSTZEROBROADCAST 1
154 #endif
155 
156 int subnetsarelocal = SUBNETSARELOCAL;
157 int hostzeroisbroadcast = HOSTZEROBROADCAST;
158 
159 /*
160  * This list is used to keep track of in_multi chains which belong to
161  * deleted interface addresses.  We use in_ifaddr so that a chain head
162  * won't be deallocated until all multicast address record are deleted.
163  */
164 static TAILQ_HEAD(, in_ifaddr) in_mk = TAILQ_HEAD_INITIALIZER(in_mk);
165 
166 /*
167  * Return 1 if an internet address is for a ``local'' host
168  * (one to which we have a connection).  If subnetsarelocal
169  * is true, this includes other subnets of the local net.
170  * Otherwise, it includes only the directly-connected (sub)nets.
171  */
172 int
173 in_localaddr(struct in_addr in)
174 {
175 	struct in_ifaddr *ia;
176 
177 	if (subnetsarelocal) {
178 		TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list)
179 			if ((in.s_addr & ia->ia_netmask) == ia->ia_net)
180 				return (1);
181 	} else {
182 		TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list)
183 			if ((in.s_addr & ia->ia_subnetmask) == ia->ia_subnet)
184 				return (1);
185 	}
186 	return (0);
187 }
188 
189 /*
190  * Determine whether an IP address is in a reserved set of addresses
191  * that may not be forwarded, or whether datagrams to that destination
192  * may be forwarded.
193  */
194 int
195 in_canforward(struct in_addr in)
196 {
197 	u_int32_t net;
198 
199 	if (IN_EXPERIMENTAL(in.s_addr) || IN_MULTICAST(in.s_addr))
200 		return (0);
201 	if (IN_CLASSA(in.s_addr)) {
202 		net = in.s_addr & IN_CLASSA_NET;
203 		if (net == 0 || net == htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
204 			return (0);
205 	}
206 	return (1);
207 }
208 
209 /*
210  * Trim a mask in a sockaddr
211  */
212 void
213 in_socktrim(struct sockaddr_in *ap)
214 {
215 	char *cplim = (char *) &ap->sin_addr;
216 	char *cp = (char *) (&ap->sin_addr + 1);
217 
218 	ap->sin_len = 0;
219 	while (--cp >= cplim)
220 		if (*cp) {
221 			(ap)->sin_len = cp - (char *) (ap) + 1;
222 			break;
223 		}
224 }
225 
226 /*
227  *  Routine to take an Internet address and convert into a
228  *  "dotted quad" representation for printing.
229  */
230 const char *
231 in_fmtaddr(struct in_addr addr)
232 {
233 	static char buf[sizeof("123.456.789.123")];
234 
235 	addr.s_addr = ntohl(addr.s_addr);
236 
237 	snprintf(buf, sizeof(buf), "%d.%d.%d.%d",
238 		(addr.s_addr >> 24) & 0xFF,
239 		(addr.s_addr >> 16) & 0xFF,
240 		(addr.s_addr >>  8) & 0xFF,
241 		(addr.s_addr >>  0) & 0xFF);
242 	return buf;
243 }
244 
245 /*
246  * Maintain the "in_maxmtu" variable, which is the largest
247  * mtu for non-local interfaces with AF_INET addresses assigned
248  * to them that are up.
249  */
250 unsigned long in_maxmtu;
251 
252 void
253 in_setmaxmtu(void)
254 {
255 	struct in_ifaddr *ia;
256 	struct ifnet *ifp;
257 	unsigned long maxmtu = 0;
258 
259 	TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list) {
260 		if ((ifp = ia->ia_ifp) == 0)
261 			continue;
262 		if ((ifp->if_flags & (IFF_UP|IFF_LOOPBACK)) != IFF_UP)
263 			continue;
264 		if (ifp->if_mtu > maxmtu)
265 			maxmtu = ifp->if_mtu;
266 	}
267 	if (maxmtu)
268 		in_maxmtu = maxmtu;
269 }
270 
271 static u_int
272 in_mask2len(struct in_addr *mask)
273 {
274 	u_int x, y;
275 	u_char *p;
276 
277 	p = (u_char *)mask;
278 	for (x = 0; x < sizeof(*mask); x++) {
279 		if (p[x] != 0xff)
280 			break;
281 	}
282 	y = 0;
283 	if (x < sizeof(*mask)) {
284 		for (y = 0; y < NBBY; y++) {
285 			if ((p[x] & (0x80 >> y)) == 0)
286 				break;
287 		}
288 	}
289 	return x * NBBY + y;
290 }
291 
292 static void
293 in_len2mask(struct in_addr *mask, u_int len)
294 {
295 	u_int i;
296 	u_char *p;
297 
298 	p = (u_char *)mask;
299 	bzero(mask, sizeof(*mask));
300 	for (i = 0; i < len / NBBY; i++)
301 		p[i] = 0xff;
302 	if (len % NBBY)
303 		p[i] = (0xff00 >> (len % NBBY)) & 0xff;
304 }
305 
306 /*
307  * Generic internet control operations (ioctl's).
308  * Ifp is 0 if not an interface-specific ioctl.
309  */
310 /* ARGSUSED */
311 int
312 in_control(struct socket *so, u_long cmd, void *data, struct ifnet *ifp,
313     struct lwp *l)
314 {
315 	struct ifreq *ifr = (struct ifreq *)data;
316 	struct in_ifaddr *ia = 0;
317 	struct in_aliasreq *ifra = (struct in_aliasreq *)data;
318 	struct sockaddr_in oldaddr;
319 	int error, hostIsNew, maskIsNew;
320 	int newifaddr = 0;
321 
322 	switch (cmd) {
323 	case SIOCALIFADDR:
324 	case SIOCDLIFADDR:
325 	case SIOCSIFADDRPREF:
326 		if (l == NULL)
327 			return (EPERM);
328 		if (kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE,
329 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
330 		    NULL) != 0)
331 			return (EPERM);
332 		/*FALLTHROUGH*/
333 	case SIOCGIFADDRPREF:
334 	case SIOCGLIFADDR:
335 		if (ifp == NULL)
336 			return EINVAL;
337 		if (cmd == SIOCGIFADDRPREF || cmd == SIOCSIFADDRPREF)
338 			return in_ifaddrpref_ioctl(so, cmd, data, ifp);
339 		else
340 			return in_lifaddr_ioctl(so, cmd, data, ifp, l);
341 	}
342 
343 	/*
344 	 * Find address for this interface, if it exists.
345 	 */
346 	if (ifp != NULL)
347 		IFP_TO_IA(ifp, ia);
348 
349 	switch (cmd) {
350 
351 	case SIOCAIFADDR:
352 	case SIOCDIFADDR:
353 	case SIOCGIFALIAS:
354 		if (ifra->ifra_addr.sin_family == AF_INET)
355 			LIST_FOREACH(ia,
356 			    &IN_IFADDR_HASH(ifra->ifra_addr.sin_addr.s_addr),
357 			    ia_hash) {
358 				if (ia->ia_ifp == ifp &&
359 				    in_hosteq(ia->ia_addr.sin_addr,
360 				    ifra->ifra_addr.sin_addr))
361 					break;
362 			}
363 		if ((cmd == SIOCDIFADDR || cmd == SIOCGIFALIAS) && ia == NULL)
364 			return (EADDRNOTAVAIL);
365 
366 #if 1 /*def COMPAT_43*/
367 		if (cmd == SIOCDIFADDR &&
368 		    ifra->ifra_addr.sin_family == AF_UNSPEC) {
369 			ifra->ifra_addr.sin_family = AF_INET;
370 		}
371 #endif
372 		/* FALLTHROUGH */
373 	case SIOCSIFADDR:
374 	case SIOCSIFDSTADDR:
375 		if (ifra->ifra_addr.sin_family != AF_INET)
376 			return (EAFNOSUPPORT);
377 		/* FALLTHROUGH */
378 	case SIOCSIFNETMASK:
379 		if (ifp == NULL)
380 			panic("in_control");
381 
382 		if (cmd == SIOCGIFALIAS)
383 			break;
384 
385 		if (ia == NULL &&
386 		    (cmd == SIOCSIFNETMASK || cmd == SIOCSIFDSTADDR))
387 			return (EADDRNOTAVAIL);
388 
389 		if (l == NULL)
390 			return (EPERM);
391 		if (kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE,
392 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
393 		    NULL) != 0)
394 			return (EPERM);
395 
396 		if (ia == 0) {
397 			MALLOC(ia, struct in_ifaddr *, sizeof(*ia),
398 			       M_IFADDR, M_WAITOK);
399 			if (ia == 0)
400 				return (ENOBUFS);
401 			bzero((void *)ia, sizeof *ia);
402 			TAILQ_INSERT_TAIL(&in_ifaddrhead, ia, ia_list);
403 			IFAREF(&ia->ia_ifa);
404 			ifa_insert(ifp, &ia->ia_ifa);
405 			ia->ia_ifa.ifa_addr = sintosa(&ia->ia_addr);
406 			ia->ia_ifa.ifa_dstaddr = sintosa(&ia->ia_dstaddr);
407 			ia->ia_ifa.ifa_netmask = sintosa(&ia->ia_sockmask);
408 #ifdef IPSELSRC
409 			ia->ia_ifa.ifa_getifa = in_getifa;
410 #else /* IPSELSRC */
411 			ia->ia_ifa.ifa_getifa = NULL;
412 #endif /* IPSELSRC */
413 			ia->ia_sockmask.sin_len = 8;
414 			if (ifp->if_flags & IFF_BROADCAST) {
415 				ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr);
416 				ia->ia_broadaddr.sin_family = AF_INET;
417 			}
418 			ia->ia_ifp = ifp;
419 			ia->ia_idsalt = arc4random() % 65535;
420 			LIST_INIT(&ia->ia_multiaddrs);
421 			newifaddr = 1;
422 		}
423 		break;
424 
425 	case SIOCSIFBRDADDR:
426 		if (l == NULL)
427 			return (EPERM);
428 		if (kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE,
429 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
430 		    NULL) != 0)
431 			return (EPERM);
432 		/* FALLTHROUGH */
433 
434 	case SIOCGIFADDR:
435 	case SIOCGIFNETMASK:
436 	case SIOCGIFDSTADDR:
437 	case SIOCGIFBRDADDR:
438 		if (ia == 0)
439 			return (EADDRNOTAVAIL);
440 		break;
441 	}
442 	error = 0;
443 	switch (cmd) {
444 
445 	case SIOCGIFADDR:
446 		ifreq_setaddr(cmd, ifr, sintocsa(&ia->ia_addr));
447 		break;
448 
449 	case SIOCGIFBRDADDR:
450 		if ((ifp->if_flags & IFF_BROADCAST) == 0)
451 			return (EINVAL);
452 		ifreq_setdstaddr(cmd, ifr, sintocsa(&ia->ia_broadaddr));
453 		break;
454 
455 	case SIOCGIFDSTADDR:
456 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
457 			return (EINVAL);
458 		ifreq_setdstaddr(cmd, ifr, sintocsa(&ia->ia_dstaddr));
459 		break;
460 
461 	case SIOCGIFNETMASK:
462 		ifreq_setaddr(cmd, ifr, sintocsa(&ia->ia_sockmask));
463 		break;
464 
465 	case SIOCSIFDSTADDR:
466 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
467 			return (EINVAL);
468 		oldaddr = ia->ia_dstaddr;
469 		ia->ia_dstaddr = *satocsin(ifreq_getdstaddr(cmd, ifr));
470 		if (ifp->if_ioctl != NULL &&
471 		    (error = (*ifp->if_ioctl)(ifp, SIOCSIFDSTADDR,
472 		                              (void *)ia)) != 0) {
473 			ia->ia_dstaddr = oldaddr;
474 			return error;
475 		}
476 		if (ia->ia_flags & IFA_ROUTE) {
477 			ia->ia_ifa.ifa_dstaddr = sintosa(&oldaddr);
478 			rtinit(&ia->ia_ifa, RTM_DELETE, RTF_HOST);
479 			ia->ia_ifa.ifa_dstaddr = sintosa(&ia->ia_dstaddr);
480 			rtinit(&ia->ia_ifa, RTM_ADD, RTF_HOST|RTF_UP);
481 		}
482 		break;
483 
484 	case SIOCSIFBRDADDR:
485 		if ((ifp->if_flags & IFF_BROADCAST) == 0)
486 			return EINVAL;
487 		ia->ia_broadaddr = *satocsin(ifreq_getbroadaddr(cmd, ifr));
488 		break;
489 
490 	case SIOCSIFADDR:
491 		error = in_ifinit(ifp, ia, satocsin(ifreq_getaddr(cmd, ifr)),
492 		    1);
493 #ifdef PFIL_HOOKS
494 		if (error == 0)
495 			(void)pfil_run_hooks(&if_pfil,
496 			    (struct mbuf **)SIOCSIFADDR, ifp, PFIL_IFADDR);
497 #endif
498 		break;
499 
500 	case SIOCSIFNETMASK:
501 		in_ifscrub(ifp, ia);
502 		ia->ia_sockmask = *satocsin(ifreq_getaddr(cmd, ifr));
503 		ia->ia_subnetmask = ia->ia_sockmask.sin_addr.s_addr;
504 		error = in_ifinit(ifp, ia, NULL, 0);
505 		break;
506 
507 	case SIOCAIFADDR:
508 		maskIsNew = 0;
509 		hostIsNew = 1;
510 		if (ia->ia_addr.sin_family != AF_INET)
511 			;
512 		else if (ifra->ifra_addr.sin_len == 0) {
513 			ifra->ifra_addr = ia->ia_addr;
514 			hostIsNew = 0;
515 		} else if (in_hosteq(ia->ia_addr.sin_addr,
516 		           ifra->ifra_addr.sin_addr))
517 			hostIsNew = 0;
518 		if (ifra->ifra_mask.sin_len) {
519 			in_ifscrub(ifp, ia);
520 			ia->ia_sockmask = ifra->ifra_mask;
521 			ia->ia_subnetmask = ia->ia_sockmask.sin_addr.s_addr;
522 			maskIsNew = 1;
523 		}
524 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
525 		    (ifra->ifra_dstaddr.sin_family == AF_INET)) {
526 			in_ifscrub(ifp, ia);
527 			ia->ia_dstaddr = ifra->ifra_dstaddr;
528 			maskIsNew  = 1; /* We lie; but the effect's the same */
529 		}
530 		if (ifra->ifra_addr.sin_family == AF_INET &&
531 		    (hostIsNew || maskIsNew)) {
532 			error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
533 		}
534 		if ((ifp->if_flags & IFF_BROADCAST) &&
535 		    (ifra->ifra_broadaddr.sin_family == AF_INET))
536 			ia->ia_broadaddr = ifra->ifra_broadaddr;
537 #ifdef PFIL_HOOKS
538 		if (error == 0)
539 			(void)pfil_run_hooks(&if_pfil,
540 			    (struct mbuf **)SIOCAIFADDR, ifp, PFIL_IFADDR);
541 #endif
542 		break;
543 
544 	case SIOCGIFALIAS:
545 		ifra->ifra_mask = ia->ia_sockmask;
546 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
547 		    (ia->ia_dstaddr.sin_family == AF_INET))
548 			ifra->ifra_dstaddr = ia->ia_dstaddr;
549 		else if ((ifp->if_flags & IFF_BROADCAST) &&
550 		    (ia->ia_broadaddr.sin_family == AF_INET))
551 			ifra->ifra_broadaddr = ia->ia_broadaddr;
552 		else
553 			memset(&ifra->ifra_broadaddr, 0,
554 			      sizeof(ifra->ifra_broadaddr));
555 		break;
556 
557 	case SIOCDIFADDR:
558 		in_purgeaddr(&ia->ia_ifa);
559 #ifdef PFIL_HOOKS
560 		(void)pfil_run_hooks(&if_pfil, (struct mbuf **)SIOCDIFADDR,
561 		    ifp, PFIL_IFADDR);
562 #endif
563 		break;
564 
565 #ifdef MROUTING
566 	case SIOCGETVIFCNT:
567 	case SIOCGETSGCNT:
568 		error = mrt_ioctl(so, cmd, data);
569 		break;
570 #endif /* MROUTING */
571 
572 	default:
573 		if (ifp == NULL || ifp->if_ioctl == NULL)
574 			return EOPNOTSUPP;
575 		error = (*ifp->if_ioctl)(ifp, cmd, data);
576 		in_setmaxmtu();
577 		break;
578 	}
579 
580 	if (error != 0 && newifaddr) {
581 		KASSERT(ia != NULL);
582 		in_purgeaddr(&ia->ia_ifa);
583 	}
584 
585 	return error;
586 }
587 
588 void
589 in_purgeaddr(struct ifaddr *ifa)
590 {
591 	struct ifnet *ifp = ifa->ifa_ifp;
592 	struct in_ifaddr *ia = (void *) ifa;
593 
594 	in_ifscrub(ifp, ia);
595 	LIST_REMOVE(ia, ia_hash);
596 	ifa_remove(ifp, &ia->ia_ifa);
597 	TAILQ_REMOVE(&in_ifaddrhead, ia, ia_list);
598 	if (ia->ia_allhosts != NULL)
599 		in_delmulti(ia->ia_allhosts);
600 	IFAFREE(&ia->ia_ifa);
601 	in_setmaxmtu();
602 }
603 
604 void
605 in_purgeif(struct ifnet *ifp)		/* MUST be called at splsoftnet() */
606 {
607 	if_purgeaddrs(ifp, AF_INET, in_purgeaddr);
608 	igmp_purgeif(ifp);		/* manipulates pools */
609 #ifdef MROUTING
610 	ip_mrouter_detach(ifp);
611 #endif
612 }
613 
614 /*
615  * SIOC[GAD]LIFADDR.
616  *	SIOCGLIFADDR: get first address. (???)
617  *	SIOCGLIFADDR with IFLR_PREFIX:
618  *		get first address that matches the specified prefix.
619  *	SIOCALIFADDR: add the specified address.
620  *	SIOCALIFADDR with IFLR_PREFIX:
621  *		EINVAL since we can't deduce hostid part of the address.
622  *	SIOCDLIFADDR: delete the specified address.
623  *	SIOCDLIFADDR with IFLR_PREFIX:
624  *		delete the first address that matches the specified prefix.
625  * return values:
626  *	EINVAL on invalid parameters
627  *	EADDRNOTAVAIL on prefix match failed/specified address not found
628  *	other values may be returned from in_ioctl()
629  */
630 static int
631 in_lifaddr_ioctl(struct socket *so, u_long cmd, void *data,
632     struct ifnet *ifp, struct lwp *l)
633 {
634 	struct if_laddrreq *iflr = (struct if_laddrreq *)data;
635 	struct ifaddr *ifa;
636 	struct sockaddr *sa;
637 
638 	/* sanity checks */
639 	if (data == NULL || ifp == NULL) {
640 		panic("invalid argument to in_lifaddr_ioctl");
641 		/*NOTRECHED*/
642 	}
643 
644 	switch (cmd) {
645 	case SIOCGLIFADDR:
646 		/* address must be specified on GET with IFLR_PREFIX */
647 		if ((iflr->flags & IFLR_PREFIX) == 0)
648 			break;
649 		/*FALLTHROUGH*/
650 	case SIOCALIFADDR:
651 	case SIOCDLIFADDR:
652 		/* address must be specified on ADD and DELETE */
653 		sa = (struct sockaddr *)&iflr->addr;
654 		if (sa->sa_family != AF_INET)
655 			return EINVAL;
656 		if (sa->sa_len != sizeof(struct sockaddr_in))
657 			return EINVAL;
658 		/* XXX need improvement */
659 		sa = (struct sockaddr *)&iflr->dstaddr;
660 		if (sa->sa_family
661 		 && sa->sa_family != AF_INET)
662 			return EINVAL;
663 		if (sa->sa_len && sa->sa_len != sizeof(struct sockaddr_in))
664 			return EINVAL;
665 		break;
666 	default: /*shouldn't happen*/
667 #if 0
668 		panic("invalid cmd to in_lifaddr_ioctl");
669 		/*NOTREACHED*/
670 #else
671 		return EOPNOTSUPP;
672 #endif
673 	}
674 	if (sizeof(struct in_addr) * NBBY < iflr->prefixlen)
675 		return EINVAL;
676 
677 	switch (cmd) {
678 	case SIOCALIFADDR:
679 	    {
680 		struct in_aliasreq ifra;
681 
682 		if (iflr->flags & IFLR_PREFIX)
683 			return EINVAL;
684 
685 		/* copy args to in_aliasreq, perform ioctl(SIOCAIFADDR). */
686 		bzero(&ifra, sizeof(ifra));
687 		bcopy(iflr->iflr_name, ifra.ifra_name,
688 			sizeof(ifra.ifra_name));
689 
690 		bcopy(&iflr->addr, &ifra.ifra_addr,
691 			((struct sockaddr *)&iflr->addr)->sa_len);
692 
693 		if (((struct sockaddr *)&iflr->dstaddr)->sa_family) {	/*XXX*/
694 			bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
695 				((struct sockaddr *)&iflr->dstaddr)->sa_len);
696 		}
697 
698 		ifra.ifra_mask.sin_family = AF_INET;
699 		ifra.ifra_mask.sin_len = sizeof(struct sockaddr_in);
700 		in_len2mask(&ifra.ifra_mask.sin_addr, iflr->prefixlen);
701 
702 		return in_control(so, SIOCAIFADDR, (void *)&ifra, ifp, l);
703 	    }
704 	case SIOCGLIFADDR:
705 	case SIOCDLIFADDR:
706 	    {
707 		struct in_ifaddr *ia;
708 		struct in_addr mask, candidate, match;
709 		struct sockaddr_in *sin;
710 		int cmp;
711 
712 		bzero(&mask, sizeof(mask));
713 		bzero(&match, sizeof(match));	/* XXX gcc */
714 		if (iflr->flags & IFLR_PREFIX) {
715 			/* lookup a prefix rather than address. */
716 			in_len2mask(&mask, iflr->prefixlen);
717 
718 			sin = (struct sockaddr_in *)&iflr->addr;
719 			match.s_addr = sin->sin_addr.s_addr;
720 			match.s_addr &= mask.s_addr;
721 
722 			/* if you set extra bits, that's wrong */
723 			if (match.s_addr != sin->sin_addr.s_addr)
724 				return EINVAL;
725 
726 			cmp = 1;
727 		} else {
728 			if (cmd == SIOCGLIFADDR) {
729 				/* on getting an address, take the 1st match */
730 				cmp = 0;	/*XXX*/
731 			} else {
732 				/* on deleting an address, do exact match */
733 				in_len2mask(&mask, 32);
734 				sin = (struct sockaddr_in *)&iflr->addr;
735 				match.s_addr = sin->sin_addr.s_addr;
736 
737 				cmp = 1;
738 			}
739 		}
740 
741 		IFADDR_FOREACH(ifa, ifp) {
742 			if (ifa->ifa_addr->sa_family != AF_INET)
743 				continue;
744 			if (cmp == 0)
745 				break;
746 			candidate.s_addr = ((struct sockaddr_in *)&ifa->ifa_addr)->sin_addr.s_addr;
747 			candidate.s_addr &= mask.s_addr;
748 			if (candidate.s_addr == match.s_addr)
749 				break;
750 		}
751 		if (ifa == NULL)
752 			return EADDRNOTAVAIL;
753 		ia = (struct in_ifaddr *)ifa;
754 
755 		if (cmd == SIOCGLIFADDR) {
756 			/* fill in the if_laddrreq structure */
757 			bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin_len);
758 
759 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
760 				bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
761 					ia->ia_dstaddr.sin_len);
762 			} else
763 				bzero(&iflr->dstaddr, sizeof(iflr->dstaddr));
764 
765 			iflr->prefixlen =
766 				in_mask2len(&ia->ia_sockmask.sin_addr);
767 
768 			iflr->flags = 0;	/*XXX*/
769 
770 			return 0;
771 		} else {
772 			struct in_aliasreq ifra;
773 
774 			/* fill in_aliasreq and do ioctl(SIOCDIFADDR) */
775 			bzero(&ifra, sizeof(ifra));
776 			bcopy(iflr->iflr_name, ifra.ifra_name,
777 				sizeof(ifra.ifra_name));
778 
779 			bcopy(&ia->ia_addr, &ifra.ifra_addr,
780 				ia->ia_addr.sin_len);
781 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
782 				bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
783 					ia->ia_dstaddr.sin_len);
784 			}
785 			bcopy(&ia->ia_sockmask, &ifra.ifra_dstaddr,
786 				ia->ia_sockmask.sin_len);
787 
788 			return in_control(so, SIOCDIFADDR, (void *)&ifra,
789 				ifp, l);
790 		}
791 	    }
792 	}
793 
794 	return EOPNOTSUPP;	/*just for safety*/
795 }
796 
797 static int
798 in_ifaddrpref_ioctl(struct socket *so, u_long cmd, void *data,
799     struct ifnet *ifp)
800 {
801 	struct if_addrprefreq *ifap = (struct if_addrprefreq *)data;
802 	struct ifaddr *ifa;
803 	struct sockaddr *sa;
804 	struct in_ifaddr *ia = NULL; /* appease gcc -Wuninitialized */
805 	struct in_addr match;
806 	struct sockaddr_in *sin;
807 
808 	/* sanity checks */
809 	if (data == NULL || ifp == NULL) {
810 		panic("invalid argument to %s", __func__);
811 		/*NOTREACHED*/
812 	}
813 
814 	/* address must be specified on ADD and DELETE */
815 	sa = (struct sockaddr *)&ifap->ifap_addr;
816 	if (sa->sa_family != AF_INET)
817 		return EINVAL;
818 	if (sa->sa_len != sizeof(struct sockaddr_in))
819 		return EINVAL;
820 
821 	switch (cmd) {
822 	case SIOCSIFADDRPREF:
823 	case SIOCGIFADDRPREF:
824 		break;
825 	default:
826 		return EOPNOTSUPP;
827 	}
828 
829 	sin = (struct sockaddr_in *)&ifap->ifap_addr;
830 	match.s_addr = sin->sin_addr.s_addr;
831 
832 	IFADDR_FOREACH(ifa, ifp) {
833 		ia = (struct in_ifaddr *)ifa;
834 		if (ia->ia_addr.sin_family != AF_INET)
835 			continue;
836 		if (ia->ia_addr.sin_addr.s_addr == match.s_addr)
837 			break;
838 	}
839 	if (ifa == NULL)
840 		return EADDRNOTAVAIL;
841 
842 	switch (cmd) {
843 	case SIOCSIFADDRPREF:
844 		ifa->ifa_preference = ifap->ifap_preference;
845 		return 0;
846 	case SIOCGIFADDRPREF:
847 		/* fill in the if_laddrreq structure */
848 		(void)memcpy(&ifap->ifap_addr, &ia->ia_addr,
849 		    ia->ia_addr.sin_len);
850 		ifap->ifap_preference = ifa->ifa_preference;
851 		return 0;
852 	default:
853 		return EOPNOTSUPP;
854 	}
855 }
856 
857 /*
858  * Delete any existing route for an interface.
859  */
860 void
861 in_ifscrub(struct ifnet *ifp, struct in_ifaddr *ia)
862 {
863 
864 	in_scrubprefix(ia);
865 }
866 
867 /*
868  * Initialize an interface's internet address
869  * and routing table entry.
870  */
871 int
872 in_ifinit(struct ifnet *ifp, struct in_ifaddr *ia,
873     const struct sockaddr_in *sin, int scrub)
874 {
875 	u_int32_t i;
876 	struct sockaddr_in oldaddr;
877 	int s = splnet(), flags = RTF_UP, error;
878 
879 	if (sin == NULL)
880 		sin = &ia->ia_addr;
881 
882 	/*
883 	 * Set up new addresses.
884 	 */
885 	oldaddr = ia->ia_addr;
886 	if (ia->ia_addr.sin_family == AF_INET)
887 		LIST_REMOVE(ia, ia_hash);
888 	ia->ia_addr = *sin;
889 	LIST_INSERT_HEAD(&IN_IFADDR_HASH(ia->ia_addr.sin_addr.s_addr), ia, ia_hash);
890 
891 	/*
892 	 * Give the interface a chance to initialize
893 	 * if this is its first address,
894 	 * and to validate the address if necessary.
895 	 */
896 	if (ifp->if_ioctl &&
897 	    (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (void *)ia)))
898 		goto bad;
899 	splx(s);
900 	if (scrub) {
901 		ia->ia_ifa.ifa_addr = sintosa(&oldaddr);
902 		in_ifscrub(ifp, ia);
903 		ia->ia_ifa.ifa_addr = sintosa(&ia->ia_addr);
904 	}
905 
906 	i = ia->ia_addr.sin_addr.s_addr;
907 	if (IN_CLASSA(i))
908 		ia->ia_netmask = IN_CLASSA_NET;
909 	else if (IN_CLASSB(i))
910 		ia->ia_netmask = IN_CLASSB_NET;
911 	else
912 		ia->ia_netmask = IN_CLASSC_NET;
913 	/*
914 	 * The subnet mask usually includes at least the standard network part,
915 	 * but may may be smaller in the case of supernetting.
916 	 * If it is set, we believe it.
917 	 */
918 	if (ia->ia_subnetmask == 0) {
919 		ia->ia_subnetmask = ia->ia_netmask;
920 		ia->ia_sockmask.sin_addr.s_addr = ia->ia_subnetmask;
921 	} else
922 		ia->ia_netmask &= ia->ia_subnetmask;
923 
924 	ia->ia_net = i & ia->ia_netmask;
925 	ia->ia_subnet = i & ia->ia_subnetmask;
926 	in_socktrim(&ia->ia_sockmask);
927 	/* re-calculate the "in_maxmtu" value */
928 	in_setmaxmtu();
929 	/*
930 	 * Add route for the network.
931 	 */
932 	ia->ia_ifa.ifa_metric = ifp->if_metric;
933 	if (ifp->if_flags & IFF_BROADCAST) {
934 		ia->ia_broadaddr.sin_addr.s_addr =
935 			ia->ia_subnet | ~ia->ia_subnetmask;
936 		ia->ia_netbroadcast.s_addr =
937 			ia->ia_net | ~ia->ia_netmask;
938 	} else if (ifp->if_flags & IFF_LOOPBACK) {
939 		ia->ia_dstaddr = ia->ia_addr;
940 		flags |= RTF_HOST;
941 	} else if (ifp->if_flags & IFF_POINTOPOINT) {
942 		if (ia->ia_dstaddr.sin_family != AF_INET)
943 			return (0);
944 		flags |= RTF_HOST;
945 	}
946 	error = in_addprefix(ia, flags);
947 	/*
948 	 * If the interface supports multicast, join the "all hosts"
949 	 * multicast group on that interface.
950 	 */
951 	if ((ifp->if_flags & IFF_MULTICAST) != 0 && ia->ia_allhosts == NULL) {
952 		struct in_addr addr;
953 
954 		addr.s_addr = INADDR_ALLHOSTS_GROUP;
955 		ia->ia_allhosts = in_addmulti(&addr, ifp);
956 	}
957 	return (error);
958 bad:
959 	splx(s);
960 	LIST_REMOVE(ia, ia_hash);
961 	ia->ia_addr = oldaddr;
962 	if (ia->ia_addr.sin_family == AF_INET)
963 		LIST_INSERT_HEAD(&IN_IFADDR_HASH(ia->ia_addr.sin_addr.s_addr),
964 		    ia, ia_hash);
965 	return (error);
966 }
967 
968 #define rtinitflags(x) \
969 	((((x)->ia_ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) != 0) \
970 	    ? RTF_HOST : 0)
971 
972 /*
973  * add a route to prefix ("connected route" in cisco terminology).
974  * does nothing if there's some interface address with the same prefix already.
975  */
976 static int
977 in_addprefix(struct in_ifaddr *target, int flags)
978 {
979 	struct in_ifaddr *ia;
980 	struct in_addr prefix, mask, p;
981 	int error;
982 
983 	if ((flags & RTF_HOST) != 0)
984 		prefix = target->ia_dstaddr.sin_addr;
985 	else {
986 		prefix = target->ia_addr.sin_addr;
987 		mask = target->ia_sockmask.sin_addr;
988 		prefix.s_addr &= mask.s_addr;
989 	}
990 
991 	TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list) {
992 		if (rtinitflags(ia))
993 			p = ia->ia_dstaddr.sin_addr;
994 		else {
995 			p = ia->ia_addr.sin_addr;
996 			p.s_addr &= ia->ia_sockmask.sin_addr.s_addr;
997 		}
998 
999 		if (prefix.s_addr != p.s_addr)
1000 			continue;
1001 
1002 		/*
1003 		 * if we got a matching prefix route inserted by other
1004 		 * interface address, we don't need to bother
1005 		 *
1006 		 * XXX RADIX_MPATH implications here? -dyoung
1007 		 */
1008 		if (ia->ia_flags & IFA_ROUTE)
1009 			return 0;
1010 	}
1011 
1012 	/*
1013 	 * noone seem to have prefix route.  insert it.
1014 	 */
1015 	error = rtinit(&target->ia_ifa, RTM_ADD, flags);
1016 	if (error == 0)
1017 		target->ia_flags |= IFA_ROUTE;
1018 	return error;
1019 }
1020 
1021 /*
1022  * remove a route to prefix ("connected route" in cisco terminology).
1023  * re-installs the route by using another interface address, if there's one
1024  * with the same prefix (otherwise we lose the route mistakenly).
1025  */
1026 static int
1027 in_scrubprefix(struct in_ifaddr *target)
1028 {
1029 	struct in_ifaddr *ia;
1030 	struct in_addr prefix, mask, p;
1031 	int error;
1032 
1033 	if ((target->ia_flags & IFA_ROUTE) == 0)
1034 		return 0;
1035 
1036 	if (rtinitflags(target))
1037 		prefix = target->ia_dstaddr.sin_addr;
1038 	else {
1039 		prefix = target->ia_addr.sin_addr;
1040 		mask = target->ia_sockmask.sin_addr;
1041 		prefix.s_addr &= mask.s_addr;
1042 	}
1043 
1044 	TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list) {
1045 		if (rtinitflags(ia))
1046 			p = ia->ia_dstaddr.sin_addr;
1047 		else {
1048 			p = ia->ia_addr.sin_addr;
1049 			p.s_addr &= ia->ia_sockmask.sin_addr.s_addr;
1050 		}
1051 
1052 		if (prefix.s_addr != p.s_addr)
1053 			continue;
1054 
1055 		/*
1056 		 * if we got a matching prefix route, move IFA_ROUTE to him
1057 		 */
1058 		if ((ia->ia_flags & IFA_ROUTE) == 0) {
1059 			rtinit(&target->ia_ifa, RTM_DELETE,
1060 			    rtinitflags(target));
1061 			target->ia_flags &= ~IFA_ROUTE;
1062 
1063 			error = rtinit(&ia->ia_ifa, RTM_ADD,
1064 			    rtinitflags(ia) | RTF_UP);
1065 			if (error == 0)
1066 				ia->ia_flags |= IFA_ROUTE;
1067 			return error;
1068 		}
1069 	}
1070 
1071 	/*
1072 	 * noone seem to have prefix route.  remove it.
1073 	 */
1074 	rtinit(&target->ia_ifa, RTM_DELETE, rtinitflags(target));
1075 	target->ia_flags &= ~IFA_ROUTE;
1076 	return 0;
1077 }
1078 
1079 #undef rtinitflags
1080 
1081 /*
1082  * Return 1 if the address might be a local broadcast address.
1083  */
1084 int
1085 in_broadcast(struct in_addr in, struct ifnet *ifp)
1086 {
1087 	struct ifaddr *ifa;
1088 
1089 	if (in.s_addr == INADDR_BROADCAST ||
1090 	    in_nullhost(in))
1091 		return 1;
1092 	if ((ifp->if_flags & IFF_BROADCAST) == 0)
1093 		return 0;
1094 	/*
1095 	 * Look through the list of addresses for a match
1096 	 * with a broadcast address.
1097 	 */
1098 #define ia (ifatoia(ifa))
1099 	IFADDR_FOREACH(ifa, ifp)
1100 		if (ifa->ifa_addr->sa_family == AF_INET &&
1101 		    !in_hosteq(in, ia->ia_addr.sin_addr) &&
1102 		    (in_hosteq(in, ia->ia_broadaddr.sin_addr) ||
1103 		     in_hosteq(in, ia->ia_netbroadcast) ||
1104 		     (hostzeroisbroadcast &&
1105 		      /*
1106 		       * Check for old-style (host 0) broadcast.
1107 		       */
1108 		      (in.s_addr == ia->ia_subnet ||
1109 		       in.s_addr == ia->ia_net))))
1110 			return 1;
1111 	return (0);
1112 #undef ia
1113 }
1114 
1115 /*
1116  * Add an address to the list of IP multicast addresses for a given interface.
1117  */
1118 struct in_multi *
1119 in_addmulti(struct in_addr *ap, struct ifnet *ifp)
1120 {
1121 	struct sockaddr_in sin;
1122 	struct in_multi *inm;
1123 	struct ifreq ifr;
1124 	int s = splsoftnet();
1125 
1126 	/*
1127 	 * See if address already in list.
1128 	 */
1129 	IN_LOOKUP_MULTI(*ap, ifp, inm);
1130 	if (inm != NULL) {
1131 		/*
1132 		 * Found it; just increment the reference count.
1133 		 */
1134 		++inm->inm_refcount;
1135 	} else {
1136 		/*
1137 		 * New address; allocate a new multicast record
1138 		 * and link it into the interface's multicast list.
1139 		 */
1140 		inm = pool_get(&inmulti_pool, PR_NOWAIT);
1141 		if (inm == NULL) {
1142 			splx(s);
1143 			return (NULL);
1144 		}
1145 		inm->inm_addr = *ap;
1146 		inm->inm_ifp = ifp;
1147 		inm->inm_refcount = 1;
1148 		LIST_INSERT_HEAD(
1149 		    &IN_MULTI_HASH(inm->inm_addr.s_addr, ifp),
1150 		    inm, inm_list);
1151 		/*
1152 		 * Ask the network driver to update its multicast reception
1153 		 * filter appropriately for the new address.
1154 		 */
1155 		sockaddr_in_init(&sin, ap, 0);
1156 		ifreq_setaddr(SIOCADDMULTI, &ifr, sintosa(&sin));
1157 		if ((ifp->if_ioctl == NULL) ||
1158 		    (*ifp->if_ioctl)(ifp, SIOCADDMULTI,(void *)&ifr) != 0) {
1159 			LIST_REMOVE(inm, inm_list);
1160 			pool_put(&inmulti_pool, inm);
1161 			splx(s);
1162 			return (NULL);
1163 		}
1164 		/*
1165 		 * Let IGMP know that we have joined a new IP multicast group.
1166 		 */
1167 		if (igmp_joingroup(inm) != 0) {
1168 			LIST_REMOVE(inm, inm_list);
1169 			pool_put(&inmulti_pool, inm);
1170 			splx(s);
1171 			return (NULL);
1172 		}
1173 		in_multientries++;
1174 	}
1175 	splx(s);
1176 	return (inm);
1177 }
1178 
1179 /*
1180  * Delete a multicast address record.
1181  */
1182 void
1183 in_delmulti(struct in_multi *inm)
1184 {
1185 	struct sockaddr_in sin;
1186 	struct ifreq ifr;
1187 	int s = splsoftnet();
1188 
1189 	if (--inm->inm_refcount == 0) {
1190 		/*
1191 		 * No remaining claims to this record; let IGMP know that
1192 		 * we are leaving the multicast group.
1193 		 */
1194 		igmp_leavegroup(inm);
1195 		/*
1196 		 * Unlink from list.
1197 		 */
1198 		LIST_REMOVE(inm, inm_list);
1199 		in_multientries--;
1200 		/*
1201 		 * Notify the network driver to update its multicast reception
1202 		 * filter.
1203 		 */
1204 		sockaddr_in_init(&sin, &inm->inm_addr, 0);
1205 		ifreq_setaddr(SIOCDELMULTI, &ifr, sintosa(&sin));
1206 		(*inm->inm_ifp->if_ioctl)(inm->inm_ifp, SIOCDELMULTI,
1207 							     (void *)&ifr);
1208 		pool_put(&inmulti_pool, inm);
1209 	}
1210 	splx(s);
1211 }
1212 #endif /* INET */
1213