xref: /netbsd-src/sys/netinet/in.c (revision da5f4674a3fc214be3572d358b66af40ab9401e7)
1 /*	$NetBSD: in.c,v 1.91 2003/08/16 11:30:35 itojun 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 1.91 2003/08/16 11:30:35 itojun Exp $");
102 
103 #include "opt_inet.h"
104 #include "opt_inet_conf.h"
105 #include "opt_mrouting.h"
106 
107 #include <sys/param.h>
108 #include <sys/ioctl.h>
109 #include <sys/errno.h>
110 #include <sys/malloc.h>
111 #include <sys/socket.h>
112 #include <sys/socketvar.h>
113 #include <sys/systm.h>
114 #include <sys/proc.h>
115 #include <sys/syslog.h>
116 
117 #include <net/if.h>
118 #include <net/route.h>
119 
120 #include <net/if_ether.h>
121 
122 #include <netinet/in_systm.h>
123 #include <netinet/in.h>
124 #include <netinet/in_var.h>
125 #include <netinet/ip.h>
126 #include <netinet/ip_var.h>
127 #include <netinet/in_pcb.h>
128 #include <netinet/if_inarp.h>
129 #include <netinet/ip_mroute.h>
130 #include <netinet/igmp_var.h>
131 
132 #ifdef INET
133 
134 static u_int in_mask2len __P((struct in_addr *));
135 static void in_len2mask __P((struct in_addr *, u_int));
136 static int in_lifaddr_ioctl __P((struct socket *, u_long, caddr_t,
137 	struct ifnet *, struct proc *));
138 
139 static int in_addprefix __P((struct in_ifaddr *, int));
140 static int in_scrubprefix __P((struct in_ifaddr *));
141 
142 #ifndef SUBNETSARELOCAL
143 #define	SUBNETSARELOCAL	1
144 #endif
145 
146 #ifndef HOSTZEROBROADCAST
147 #define HOSTZEROBROADCAST 1
148 #endif
149 
150 int subnetsarelocal = SUBNETSARELOCAL;
151 int hostzeroisbroadcast = HOSTZEROBROADCAST;
152 
153 /*
154  * This list is used to keep track of in_multi chains which belong to
155  * deleted interface addresses.  We use in_ifaddr so that a chain head
156  * won't be deallocated until all multicast address record are deleted.
157  */
158 static TAILQ_HEAD(, in_ifaddr) in_mk = TAILQ_HEAD_INITIALIZER(in_mk);
159 
160 /*
161  * Return 1 if an internet address is for a ``local'' host
162  * (one to which we have a connection).  If subnetsarelocal
163  * is true, this includes other subnets of the local net.
164  * Otherwise, it includes only the directly-connected (sub)nets.
165  */
166 int
167 in_localaddr(in)
168 	struct in_addr in;
169 {
170 	struct in_ifaddr *ia;
171 
172 	if (subnetsarelocal) {
173 		TAILQ_FOREACH(ia, &in_ifaddr, ia_list)
174 			if ((in.s_addr & ia->ia_netmask) == ia->ia_net)
175 				return (1);
176 	} else {
177 		TAILQ_FOREACH(ia, &in_ifaddr, ia_list)
178 			if ((in.s_addr & ia->ia_subnetmask) == ia->ia_subnet)
179 				return (1);
180 	}
181 	return (0);
182 }
183 
184 /*
185  * Determine whether an IP address is in a reserved set of addresses
186  * that may not be forwarded, or whether datagrams to that destination
187  * may be forwarded.
188  */
189 int
190 in_canforward(in)
191 	struct in_addr in;
192 {
193 	u_int32_t net;
194 
195 	if (IN_EXPERIMENTAL(in.s_addr) || IN_MULTICAST(in.s_addr))
196 		return (0);
197 	if (IN_CLASSA(in.s_addr)) {
198 		net = in.s_addr & IN_CLASSA_NET;
199 		if (net == 0 || net == htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
200 			return (0);
201 	}
202 	return (1);
203 }
204 
205 /*
206  * Trim a mask in a sockaddr
207  */
208 void
209 in_socktrim(ap)
210 	struct sockaddr_in *ap;
211 {
212 	char *cplim = (char *) &ap->sin_addr;
213 	char *cp = (char *) (&ap->sin_addr + 1);
214 
215 	ap->sin_len = 0;
216 	while (--cp >= cplim)
217 		if (*cp) {
218 			(ap)->sin_len = cp - (char *) (ap) + 1;
219 			break;
220 		}
221 }
222 
223 /*
224  *  Routine to take an Internet address and convert into a
225  *  "dotted quad" representation for printing.
226  */
227 const char *
228 in_fmtaddr(addr)
229 	struct in_addr addr;
230 {
231 	static char buf[sizeof("123.456.789.123")];
232 
233 	addr.s_addr = ntohl(addr.s_addr);
234 
235 	sprintf(buf, "%d.%d.%d.%d",
236 		(addr.s_addr >> 24) & 0xFF,
237 		(addr.s_addr >> 16) & 0xFF,
238 		(addr.s_addr >>  8) & 0xFF,
239 		(addr.s_addr >>  0) & 0xFF);
240 	return buf;
241 }
242 
243 /*
244  * Maintain the "in_maxmtu" variable, which is the largest
245  * mtu for non-local interfaces with AF_INET addresses assigned
246  * to them that are up.
247  */
248 unsigned long in_maxmtu;
249 
250 void
251 in_setmaxmtu()
252 {
253 	struct in_ifaddr *ia;
254 	struct ifnet *ifp;
255 	unsigned long maxmtu = 0;
256 
257 	TAILQ_FOREACH(ia, &in_ifaddr, ia_list) {
258 		if ((ifp = ia->ia_ifp) == 0)
259 			continue;
260 		if ((ifp->if_flags & (IFF_UP|IFF_LOOPBACK)) != IFF_UP)
261 			continue;
262 		if (ifp->if_mtu > maxmtu)
263 			maxmtu = ifp->if_mtu;
264 	}
265 	if (maxmtu)
266 		in_maxmtu = maxmtu;
267 }
268 
269 static u_int
270 in_mask2len(mask)
271 	struct in_addr *mask;
272 {
273 	u_int x, y;
274 	u_char *p;
275 
276 	p = (u_char *)mask;
277 	for (x = 0; x < sizeof(*mask); x++) {
278 		if (p[x] != 0xff)
279 			break;
280 	}
281 	y = 0;
282 	if (x < sizeof(*mask)) {
283 		for (y = 0; y < 8; y++) {
284 			if ((p[x] & (0x80 >> y)) == 0)
285 				break;
286 		}
287 	}
288 	return x * 8 + y;
289 }
290 
291 static void
292 in_len2mask(mask, len)
293 	struct in_addr *mask;
294 	u_int len;
295 {
296 	u_int i;
297 	u_char *p;
298 
299 	p = (u_char *)mask;
300 	bzero(mask, sizeof(*mask));
301 	for (i = 0; i < len / 8; i++)
302 		p[i] = 0xff;
303 	if (len % 8)
304 		p[i] = (0xff00 >> (len % 8)) & 0xff;
305 }
306 
307 /*
308  * Generic internet control operations (ioctl's).
309  * Ifp is 0 if not an interface-specific ioctl.
310  */
311 /* ARGSUSED */
312 int
313 in_control(so, cmd, data, ifp, p)
314 	struct socket *so;
315 	u_long cmd;
316 	caddr_t data;
317 	struct ifnet *ifp;
318 	struct proc *p;
319 {
320 	struct ifreq *ifr = (struct ifreq *)data;
321 	struct in_ifaddr *ia = 0;
322 	struct in_aliasreq *ifra = (struct in_aliasreq *)data;
323 	struct sockaddr_in oldaddr;
324 	int error, hostIsNew, maskIsNew;
325 
326 	switch (cmd) {
327 	case SIOCALIFADDR:
328 	case SIOCDLIFADDR:
329 		if (p == 0 || (error = suser(p->p_ucred, &p->p_acflag)))
330 			return (EPERM);
331 		/*fall through*/
332 	case SIOCGLIFADDR:
333 		if (!ifp)
334 			return EINVAL;
335 		return in_lifaddr_ioctl(so, cmd, data, ifp, p);
336 	}
337 
338 	/*
339 	 * Find address for this interface, if it exists.
340 	 */
341 	if (ifp)
342 		IFP_TO_IA(ifp, ia);
343 
344 	switch (cmd) {
345 
346 	case SIOCAIFADDR:
347 	case SIOCDIFADDR:
348 	case SIOCGIFALIAS:
349 		if (ifra->ifra_addr.sin_family == AF_INET)
350 			LIST_FOREACH(ia,
351 			    &IN_IFADDR_HASH(ifra->ifra_addr.sin_addr.s_addr),
352 			    ia_hash) {
353 				if (ia->ia_ifp == ifp  &&
354 				    in_hosteq(ia->ia_addr.sin_addr,
355 				    ifra->ifra_addr.sin_addr))
356 					break;
357 			}
358 		if (cmd == SIOCDIFADDR) {
359 			if (ia == 0)
360 				return (EADDRNOTAVAIL);
361 #if 1 /*def COMPAT_43*/
362 			if (ifra->ifra_addr.sin_family == AF_UNSPEC)
363 				ifra->ifra_addr.sin_family = AF_INET;
364 #endif
365 		}
366 		/* FALLTHROUGH */
367 	case SIOCSIFADDR:
368 	case SIOCSIFDSTADDR:
369 		if (ifra->ifra_addr.sin_family != AF_INET)
370 			return (EAFNOSUPPORT);
371 		/* FALLTHROUGH */
372 	case SIOCSIFNETMASK:
373 		if (ifp == 0)
374 			panic("in_control");
375 
376 		if (cmd == SIOCGIFALIAS)
377 			break;
378 
379 		if (p == 0 || (error = suser(p->p_ucred, &p->p_acflag)))
380 			return (EPERM);
381 
382 		if (ia == 0) {
383 			MALLOC(ia, struct in_ifaddr *, sizeof(*ia),
384 			       M_IFADDR, M_WAITOK);
385 			if (ia == 0)
386 				return (ENOBUFS);
387 			bzero((caddr_t)ia, sizeof *ia);
388 			TAILQ_INSERT_TAIL(&in_ifaddr, ia, ia_list);
389 			IFAREF(&ia->ia_ifa);
390 			TAILQ_INSERT_TAIL(&ifp->if_addrlist, &ia->ia_ifa,
391 			    ifa_list);
392 			IFAREF(&ia->ia_ifa);
393 			ia->ia_ifa.ifa_addr = sintosa(&ia->ia_addr);
394 			ia->ia_ifa.ifa_dstaddr = sintosa(&ia->ia_dstaddr);
395 			ia->ia_ifa.ifa_netmask = sintosa(&ia->ia_sockmask);
396 			ia->ia_sockmask.sin_len = 8;
397 			if (ifp->if_flags & IFF_BROADCAST) {
398 				ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr);
399 				ia->ia_broadaddr.sin_family = AF_INET;
400 			}
401 			ia->ia_ifp = ifp;
402 			LIST_INIT(&ia->ia_multiaddrs);
403 		}
404 		break;
405 
406 	case SIOCSIFBRDADDR:
407 		if (p == 0 || (error = suser(p->p_ucred, &p->p_acflag)))
408 			return (EPERM);
409 		/* FALLTHROUGH */
410 
411 	case SIOCGIFADDR:
412 	case SIOCGIFNETMASK:
413 	case SIOCGIFDSTADDR:
414 	case SIOCGIFBRDADDR:
415 		if (ia == 0)
416 			return (EADDRNOTAVAIL);
417 		break;
418 	}
419 	switch (cmd) {
420 
421 	case SIOCGIFADDR:
422 		*satosin(&ifr->ifr_addr) = ia->ia_addr;
423 		break;
424 
425 	case SIOCGIFBRDADDR:
426 		if ((ifp->if_flags & IFF_BROADCAST) == 0)
427 			return (EINVAL);
428 		*satosin(&ifr->ifr_dstaddr) = ia->ia_broadaddr;
429 		break;
430 
431 	case SIOCGIFDSTADDR:
432 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
433 			return (EINVAL);
434 		*satosin(&ifr->ifr_dstaddr) = ia->ia_dstaddr;
435 		break;
436 
437 	case SIOCGIFNETMASK:
438 		*satosin(&ifr->ifr_addr) = ia->ia_sockmask;
439 		break;
440 
441 	case SIOCSIFDSTADDR:
442 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
443 			return (EINVAL);
444 		oldaddr = ia->ia_dstaddr;
445 		ia->ia_dstaddr = *satosin(&ifr->ifr_dstaddr);
446 		if (ifp->if_ioctl && (error = (*ifp->if_ioctl)
447 					(ifp, SIOCSIFDSTADDR, (caddr_t)ia))) {
448 			ia->ia_dstaddr = oldaddr;
449 			return (error);
450 		}
451 		if (ia->ia_flags & IFA_ROUTE) {
452 			ia->ia_ifa.ifa_dstaddr = sintosa(&oldaddr);
453 			rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
454 			ia->ia_ifa.ifa_dstaddr = sintosa(&ia->ia_dstaddr);
455 			rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP);
456 		}
457 		break;
458 
459 	case SIOCSIFBRDADDR:
460 		if ((ifp->if_flags & IFF_BROADCAST) == 0)
461 			return (EINVAL);
462 		ia->ia_broadaddr = *satosin(&ifr->ifr_broadaddr);
463 		break;
464 
465 	case SIOCSIFADDR:
466 		error = in_ifinit(ifp, ia, satosin(&ifr->ifr_addr), 1);
467 		return error;
468 
469 	case SIOCSIFNETMASK:
470 		ia->ia_subnetmask = ia->ia_sockmask.sin_addr.s_addr =
471 		    ifra->ifra_addr.sin_addr.s_addr;
472 		break;
473 
474 	case SIOCAIFADDR:
475 		maskIsNew = 0;
476 		hostIsNew = 1;
477 		error = 0;
478 		if (ia->ia_addr.sin_family == AF_INET) {
479 			if (ifra->ifra_addr.sin_len == 0) {
480 				ifra->ifra_addr = ia->ia_addr;
481 				hostIsNew = 0;
482 			} else if (in_hosteq(ia->ia_addr.sin_addr, ifra->ifra_addr.sin_addr))
483 				hostIsNew = 0;
484 		}
485 		if (ifra->ifra_mask.sin_len) {
486 			in_ifscrub(ifp, ia);
487 			ia->ia_sockmask = ifra->ifra_mask;
488 			ia->ia_subnetmask = ia->ia_sockmask.sin_addr.s_addr;
489 			maskIsNew = 1;
490 		}
491 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
492 		    (ifra->ifra_dstaddr.sin_family == AF_INET)) {
493 			in_ifscrub(ifp, ia);
494 			ia->ia_dstaddr = ifra->ifra_dstaddr;
495 			maskIsNew  = 1; /* We lie; but the effect's the same */
496 		}
497 		if (ifra->ifra_addr.sin_family == AF_INET &&
498 		    (hostIsNew || maskIsNew)) {
499 			error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
500 		}
501 		if ((ifp->if_flags & IFF_BROADCAST) &&
502 		    (ifra->ifra_broadaddr.sin_family == AF_INET))
503 			ia->ia_broadaddr = ifra->ifra_broadaddr;
504 		return (error);
505 
506 	case SIOCGIFALIAS:
507 		ifra->ifra_mask = ia->ia_sockmask;
508 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
509 		    (ia->ia_dstaddr.sin_family == AF_INET))
510 			ifra->ifra_dstaddr = ia->ia_dstaddr;
511 		else if ((ifp->if_flags & IFF_BROADCAST) &&
512 		    (ia->ia_broadaddr.sin_family == AF_INET))
513 			ifra->ifra_broadaddr = ia->ia_broadaddr;
514 		else
515 			bzero(&ifra->ifra_broadaddr,
516 			      sizeof(ifra->ifra_broadaddr));
517 		return 0;
518 
519 	case SIOCDIFADDR:
520 		in_purgeaddr(&ia->ia_ifa, ifp);
521 		break;
522 
523 #ifdef MROUTING
524 	case SIOCGETVIFCNT:
525 	case SIOCGETSGCNT:
526 		return (mrt_ioctl(so, cmd, data));
527 #endif /* MROUTING */
528 
529 	default:
530 		if (ifp == 0 || ifp->if_ioctl == 0)
531 			return (EOPNOTSUPP);
532 		error = (*ifp->if_ioctl)(ifp, cmd, data);
533 		in_setmaxmtu();
534 		return (error);
535 	}
536 	return (0);
537 }
538 
539 void
540 in_purgeaddr(ifa, ifp)
541 	struct ifaddr *ifa;
542 	struct ifnet *ifp;
543 {
544 	struct in_ifaddr *ia = (void *) ifa;
545 	struct in_ifaddr *nia;
546 	struct inpcb *inp, *inp_ialink;
547 
548 	in_ifscrub(ifp, ia);
549 
550 	nia = ia;
551 	NEXT_IA_WITH_SAME_ADDR(nia);
552 	/*
553 	 * Kick all the sockets!
554 	 */
555 	for (inp = LIST_FIRST(&ia->ia_inpcbs); inp != NULL; inp = inp_ialink) {
556 		inp_ialink = LIST_NEXT(inp, inp_ialink);
557 		KASSERT(inp != inp_ialink);
558 		LIST_REMOVE(inp, inp_ialink);
559 		IFAFREE(&ia->ia_ifa);
560 		inp->inp_ia = NULL;
561 		if (nia != NULL) {
562 			KASSERT(nia != ia);
563 			inp->inp_ia = nia;
564 			IFAREF(&nia->ia_ifa);
565 			LIST_INSERT_HEAD(&nia->ia_inpcbs, inp, inp_ialink);
566 		} else if (inp->inp_socket != NULL) {
567 #if 0
568 			if ((inp->inp_socket->so_state & SS_NOFDREF) &&
569 			    inp->inp_socket->so_head == NULL) {
570 				soabort(inp->inp_socket);
571 			} else {
572 				inp->inp_socket->so_error = ECONNABORTED;
573 				sorwakeup(inp->inp_socket);
574 				sowwakeup(inp->inp_socket);
575 			}
576 #endif
577 		}
578 	}
579 
580 	LIST_REMOVE(ia, ia_hash);
581 	TAILQ_REMOVE(&ifp->if_addrlist, &ia->ia_ifa, ifa_list);
582 	IFAFREE(&ia->ia_ifa);
583 	TAILQ_REMOVE(&in_ifaddr, ia, ia_list);
584 	if (ia->ia_allhosts != NULL)
585 		in_delmulti(ia->ia_allhosts);
586 	IFAFREE(&ia->ia_ifa);
587 	in_setmaxmtu();
588 }
589 
590 void
591 in_purgeif(ifp)
592 	struct ifnet *ifp;
593 {
594 	struct ifaddr *ifa, *nifa;
595 
596 	for (ifa = TAILQ_FIRST(&ifp->if_addrlist); ifa != NULL; ifa = nifa) {
597 		nifa = TAILQ_NEXT(ifa, ifa_list);
598 		if (ifa->ifa_addr->sa_family != AF_INET)
599 			continue;
600 		in_purgeaddr(ifa, ifp);
601 	}
602 
603 	igmp_purgeif(ifp);
604 #ifdef MROUTING
605 	ip_mrouter_detach(ifp);
606 #endif
607 }
608 
609 /*
610  * SIOC[GAD]LIFADDR.
611  *	SIOCGLIFADDR: get first address. (???)
612  *	SIOCGLIFADDR with IFLR_PREFIX:
613  *		get first address that matches the specified prefix.
614  *	SIOCALIFADDR: add the specified address.
615  *	SIOCALIFADDR with IFLR_PREFIX:
616  *		EINVAL since we can't deduce hostid part of the address.
617  *	SIOCDLIFADDR: delete the specified address.
618  *	SIOCDLIFADDR with IFLR_PREFIX:
619  *		delete the first address that matches the specified prefix.
620  * return values:
621  *	EINVAL on invalid parameters
622  *	EADDRNOTAVAIL on prefix match failed/specified address not found
623  *	other values may be returned from in_ioctl()
624  */
625 static int
626 in_lifaddr_ioctl(so, cmd, data, ifp, p)
627 	struct socket *so;
628 	u_long cmd;
629 	caddr_t	data;
630 	struct ifnet *ifp;
631 	struct proc *p;
632 {
633 	struct if_laddrreq *iflr = (struct if_laddrreq *)data;
634 	struct ifaddr *ifa;
635 	struct sockaddr *sa;
636 
637 	/* sanity checks */
638 	if (!data || !ifp) {
639 		panic("invalid argument to in_lifaddr_ioctl");
640 		/*NOTRECHED*/
641 	}
642 
643 	switch (cmd) {
644 	case SIOCGLIFADDR:
645 		/* address must be specified on GET with IFLR_PREFIX */
646 		if ((iflr->flags & IFLR_PREFIX) == 0)
647 			break;
648 		/*FALLTHROUGH*/
649 	case SIOCALIFADDR:
650 	case SIOCDLIFADDR:
651 		/* address must be specified on ADD and DELETE */
652 		sa = (struct sockaddr *)&iflr->addr;
653 		if (sa->sa_family != AF_INET)
654 			return EINVAL;
655 		if (sa->sa_len != sizeof(struct sockaddr_in))
656 			return EINVAL;
657 		/* XXX need improvement */
658 		sa = (struct sockaddr *)&iflr->dstaddr;
659 		if (sa->sa_family
660 		 && sa->sa_family != AF_INET)
661 			return EINVAL;
662 		if (sa->sa_len && sa->sa_len != sizeof(struct sockaddr_in))
663 			return EINVAL;
664 		break;
665 	default: /*shouldn't happen*/
666 #if 0
667 		panic("invalid cmd to in_lifaddr_ioctl");
668 		/*NOTREACHED*/
669 #else
670 		return EOPNOTSUPP;
671 #endif
672 	}
673 	if (sizeof(struct in_addr) * 8 < iflr->prefixlen)
674 		return EINVAL;
675 
676 	switch (cmd) {
677 	case SIOCALIFADDR:
678 	    {
679 		struct in_aliasreq ifra;
680 
681 		if (iflr->flags & IFLR_PREFIX)
682 			return EINVAL;
683 
684 		/* copy args to in_aliasreq, perform ioctl(SIOCAIFADDR_IN6). */
685 		bzero(&ifra, sizeof(ifra));
686 		bcopy(iflr->iflr_name, ifra.ifra_name,
687 			sizeof(ifra.ifra_name));
688 
689 		bcopy(&iflr->addr, &ifra.ifra_addr,
690 			((struct sockaddr *)&iflr->addr)->sa_len);
691 
692 		if (((struct sockaddr *)&iflr->dstaddr)->sa_family) {	/*XXX*/
693 			bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
694 				((struct sockaddr *)&iflr->dstaddr)->sa_len);
695 		}
696 
697 		ifra.ifra_mask.sin_family = AF_INET;
698 		ifra.ifra_mask.sin_len = sizeof(struct sockaddr_in);
699 		in_len2mask(&ifra.ifra_mask.sin_addr, iflr->prefixlen);
700 
701 		return in_control(so, SIOCAIFADDR, (caddr_t)&ifra, ifp, p);
702 	    }
703 	case SIOCGLIFADDR:
704 	case SIOCDLIFADDR:
705 	    {
706 		struct in_ifaddr *ia;
707 		struct in_addr mask, candidate, match;
708 		struct sockaddr_in *sin;
709 		int cmp;
710 
711 		bzero(&mask, sizeof(mask));
712 		if (iflr->flags & IFLR_PREFIX) {
713 			/* lookup a prefix rather than address. */
714 			in_len2mask(&mask, iflr->prefixlen);
715 
716 			sin = (struct sockaddr_in *)&iflr->addr;
717 			match.s_addr = sin->sin_addr.s_addr;
718 			match.s_addr &= mask.s_addr;
719 
720 			/* if you set extra bits, that's wrong */
721 			if (match.s_addr != sin->sin_addr.s_addr)
722 				return EINVAL;
723 
724 			cmp = 1;
725 		} else {
726 			if (cmd == SIOCGLIFADDR) {
727 				/* on getting an address, take the 1st match */
728 				cmp = 0;	/*XXX*/
729 			} else {
730 				/* on deleting an address, do exact match */
731 				in_len2mask(&mask, 32);
732 				sin = (struct sockaddr_in *)&iflr->addr;
733 				match.s_addr = sin->sin_addr.s_addr;
734 
735 				cmp = 1;
736 			}
737 		}
738 
739 		TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
740 			if (ifa->ifa_addr->sa_family != AF_INET6)
741 				continue;
742 			if (!cmp)
743 				break;
744 			candidate.s_addr = ((struct sockaddr_in *)&ifa->ifa_addr)->sin_addr.s_addr;
745 			candidate.s_addr &= mask.s_addr;
746 			if (candidate.s_addr == match.s_addr)
747 				break;
748 		}
749 		if (!ifa)
750 			return EADDRNOTAVAIL;
751 		ia = (struct in_ifaddr *)ifa;
752 
753 		if (cmd == SIOCGLIFADDR) {
754 			/* fill in the if_laddrreq structure */
755 			bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin_len);
756 
757 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
758 				bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
759 					ia->ia_dstaddr.sin_len);
760 			} else
761 				bzero(&iflr->dstaddr, sizeof(iflr->dstaddr));
762 
763 			iflr->prefixlen =
764 				in_mask2len(&ia->ia_sockmask.sin_addr);
765 
766 			iflr->flags = 0;	/*XXX*/
767 
768 			return 0;
769 		} else {
770 			struct in_aliasreq ifra;
771 
772 			/* fill in_aliasreq and do ioctl(SIOCDIFADDR_IN6) */
773 			bzero(&ifra, sizeof(ifra));
774 			bcopy(iflr->iflr_name, ifra.ifra_name,
775 				sizeof(ifra.ifra_name));
776 
777 			bcopy(&ia->ia_addr, &ifra.ifra_addr,
778 				ia->ia_addr.sin_len);
779 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
780 				bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
781 					ia->ia_dstaddr.sin_len);
782 			}
783 			bcopy(&ia->ia_sockmask, &ifra.ifra_dstaddr,
784 				ia->ia_sockmask.sin_len);
785 
786 			return in_control(so, SIOCDIFADDR, (caddr_t)&ifra,
787 				ifp, p);
788 		}
789 	    }
790 	}
791 
792 	return EOPNOTSUPP;	/*just for safety*/
793 }
794 
795 /*
796  * Delete any existing route for an interface.
797  */
798 void
799 in_ifscrub(ifp, ia)
800 	struct ifnet *ifp;
801 	struct in_ifaddr *ia;
802 {
803 
804 	in_scrubprefix(ia);
805 }
806 
807 /*
808  * Initialize an interface's internet address
809  * and routing table entry.
810  */
811 int
812 in_ifinit(ifp, ia, sin, scrub)
813 	struct ifnet *ifp;
814 	struct in_ifaddr *ia;
815 	struct sockaddr_in *sin;
816 	int scrub;
817 {
818 	u_int32_t i = sin->sin_addr.s_addr;
819 	struct sockaddr_in oldaddr;
820 	int s = splnet(), flags = RTF_UP, error;
821 
822 	/*
823 	 * Set up new addresses.
824 	 */
825 	oldaddr = ia->ia_addr;
826 	if (ia->ia_addr.sin_family == AF_INET)
827 		LIST_REMOVE(ia, ia_hash);
828 	ia->ia_addr = *sin;
829 	LIST_INSERT_HEAD(&IN_IFADDR_HASH(ia->ia_addr.sin_addr.s_addr), ia, ia_hash);
830 
831 	/*
832 	 * Give the interface a chance to initialize
833 	 * if this is its first address,
834 	 * and to validate the address if necessary.
835 	 */
836 	if (ifp->if_ioctl &&
837 	    (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia)))
838 		goto bad;
839 	splx(s);
840 	if (scrub) {
841 		ia->ia_ifa.ifa_addr = sintosa(&oldaddr);
842 		in_ifscrub(ifp, ia);
843 		ia->ia_ifa.ifa_addr = sintosa(&ia->ia_addr);
844 	}
845 
846 	if (IN_CLASSA(i))
847 		ia->ia_netmask = IN_CLASSA_NET;
848 	else if (IN_CLASSB(i))
849 		ia->ia_netmask = IN_CLASSB_NET;
850 	else
851 		ia->ia_netmask = IN_CLASSC_NET;
852 	/*
853 	 * The subnet mask usually includes at least the standard network part,
854 	 * but may may be smaller in the case of supernetting.
855 	 * If it is set, we believe it.
856 	 */
857 	if (ia->ia_subnetmask == 0) {
858 		ia->ia_subnetmask = ia->ia_netmask;
859 		ia->ia_sockmask.sin_addr.s_addr = ia->ia_subnetmask;
860 	} else
861 		ia->ia_netmask &= ia->ia_subnetmask;
862 
863 	ia->ia_net = i & ia->ia_netmask;
864 	ia->ia_subnet = i & ia->ia_subnetmask;
865 	in_socktrim(&ia->ia_sockmask);
866 	/* re-calculate the "in_maxmtu" value */
867 	in_setmaxmtu();
868 	/*
869 	 * Add route for the network.
870 	 */
871 	ia->ia_ifa.ifa_metric = ifp->if_metric;
872 	if (ifp->if_flags & IFF_BROADCAST) {
873 		ia->ia_broadaddr.sin_addr.s_addr =
874 			ia->ia_subnet | ~ia->ia_subnetmask;
875 		ia->ia_netbroadcast.s_addr =
876 			ia->ia_net | ~ia->ia_netmask;
877 	} else if (ifp->if_flags & IFF_LOOPBACK) {
878 		ia->ia_dstaddr = ia->ia_addr;
879 		flags |= RTF_HOST;
880 	} else if (ifp->if_flags & IFF_POINTOPOINT) {
881 		if (ia->ia_dstaddr.sin_family != AF_INET)
882 			return (0);
883 		flags |= RTF_HOST;
884 	}
885 	error = in_addprefix(ia, flags);
886 	/*
887 	 * If the interface supports multicast, join the "all hosts"
888 	 * multicast group on that interface.
889 	 */
890 	if ((ifp->if_flags & IFF_MULTICAST) != 0 && ia->ia_allhosts == NULL) {
891 		struct in_addr addr;
892 
893 		addr.s_addr = INADDR_ALLHOSTS_GROUP;
894 		ia->ia_allhosts = in_addmulti(&addr, ifp);
895 	}
896 	return (error);
897 bad:
898 	splx(s);
899 	LIST_REMOVE(ia, ia_hash);
900 	ia->ia_addr = oldaddr;
901 	if (ia->ia_addr.sin_family == AF_INET)
902 		LIST_INSERT_HEAD(&IN_IFADDR_HASH(ia->ia_addr.sin_addr.s_addr),
903 		    ia, ia_hash);
904 	return (error);
905 }
906 
907 #define rtinitflags(x) \
908 	((((x)->ia_ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) != 0) \
909 	    ? RTF_HOST : 0)
910 
911 /*
912  * add a route to prefix ("connected route" in cisco terminology).
913  * does nothing if there's some interface address with the same prefix already.
914  */
915 static int
916 in_addprefix(target, flags)
917 	struct in_ifaddr *target;
918 	int flags;
919 {
920 	struct in_ifaddr *ia;
921 	struct in_addr prefix, mask, p;
922 	int error;
923 
924 	if ((flags & RTF_HOST) != 0)
925 		prefix = target->ia_dstaddr.sin_addr;
926 	else {
927 		prefix = target->ia_addr.sin_addr;
928 		mask = target->ia_sockmask.sin_addr;
929 		prefix.s_addr &= mask.s_addr;
930 	}
931 
932 	TAILQ_FOREACH(ia, &in_ifaddr, ia_list) {
933 		if (rtinitflags(ia))
934 			p = ia->ia_dstaddr.sin_addr;
935 		else {
936 			p = ia->ia_addr.sin_addr;
937 			p.s_addr &= ia->ia_sockmask.sin_addr.s_addr;
938 		}
939 
940 		if (prefix.s_addr != p.s_addr)
941 			continue;
942 
943 		/*
944 		 * if we got a matching prefix route inserted by other
945 		 * interface address, we don't need to bother
946 		 */
947 		if (ia->ia_flags & IFA_ROUTE)
948 			return 0;
949 	}
950 
951 	/*
952 	 * noone seem to have prefix route.  insert it.
953 	 */
954 	error = rtinit(&target->ia_ifa, (int)RTM_ADD, flags);
955 	if (!error)
956 		target->ia_flags |= IFA_ROUTE;
957 	return error;
958 }
959 
960 /*
961  * remove a route to prefix ("connected route" in cisco terminology).
962  * re-installs the route by using another interface address, if there's one
963  * with the same prefix (otherwise we lose the route mistakenly).
964  */
965 static int
966 in_scrubprefix(target)
967 	struct in_ifaddr *target;
968 {
969 	struct in_ifaddr *ia;
970 	struct in_addr prefix, mask, p;
971 	int error;
972 
973 	if ((target->ia_flags & IFA_ROUTE) == 0)
974 		return 0;
975 
976 	if (rtinitflags(target))
977 		prefix = target->ia_dstaddr.sin_addr;
978 	else {
979 		prefix = target->ia_addr.sin_addr;
980 		mask = target->ia_sockmask.sin_addr;
981 		prefix.s_addr &= mask.s_addr;
982 	}
983 
984 	TAILQ_FOREACH(ia, &in_ifaddr, ia_list) {
985 		if (rtinitflags(ia))
986 			p = ia->ia_dstaddr.sin_addr;
987 		else {
988 			p = ia->ia_addr.sin_addr;
989 			p.s_addr &= ia->ia_sockmask.sin_addr.s_addr;
990 		}
991 
992 		if (prefix.s_addr != p.s_addr)
993 			continue;
994 
995 		/*
996 		 * if we got a matching prefix route, move IFA_ROUTE to him
997 		 */
998 		if ((ia->ia_flags & IFA_ROUTE) == 0) {
999 			rtinit(&(target->ia_ifa), (int)RTM_DELETE,
1000 			    rtinitflags(target));
1001 			target->ia_flags &= ~IFA_ROUTE;
1002 
1003 			error = rtinit(&ia->ia_ifa, (int)RTM_ADD,
1004 			    rtinitflags(ia) | RTF_UP);
1005 			if (error == 0)
1006 				ia->ia_flags |= IFA_ROUTE;
1007 			return error;
1008 		}
1009 	}
1010 
1011 	/*
1012 	 * noone seem to have prefix route.  remove it.
1013 	 */
1014 	rtinit(&(target->ia_ifa), (int)RTM_DELETE, rtinitflags(target));
1015 	target->ia_flags &= ~IFA_ROUTE;
1016 	return 0;
1017 }
1018 
1019 #undef rtinitflags
1020 
1021 /*
1022  * Return 1 if the address might be a local broadcast address.
1023  */
1024 int
1025 in_broadcast(in, ifp)
1026 	struct in_addr in;
1027 	struct ifnet *ifp;
1028 {
1029 	struct ifaddr *ifa;
1030 
1031 	if (in.s_addr == INADDR_BROADCAST ||
1032 	    in_nullhost(in))
1033 		return 1;
1034 	if ((ifp->if_flags & IFF_BROADCAST) == 0)
1035 		return 0;
1036 	/*
1037 	 * Look through the list of addresses for a match
1038 	 * with a broadcast address.
1039 	 */
1040 #define ia (ifatoia(ifa))
1041 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1042 		if (ifa->ifa_addr->sa_family == AF_INET &&
1043 		    !in_hosteq(in, ia->ia_addr.sin_addr) &&
1044 		    (in_hosteq(in, ia->ia_broadaddr.sin_addr) ||
1045 		     in_hosteq(in, ia->ia_netbroadcast) ||
1046 		     (hostzeroisbroadcast &&
1047 		      /*
1048 		       * Check for old-style (host 0) broadcast.
1049 		       */
1050 		      (in.s_addr == ia->ia_subnet ||
1051 		       in.s_addr == ia->ia_net))))
1052 			return 1;
1053 	return (0);
1054 #undef ia
1055 }
1056 
1057 /*
1058  * Add an address to the list of IP multicast addresses for a given interface.
1059  */
1060 struct in_multi *
1061 in_addmulti(ap, ifp)
1062 	struct in_addr *ap;
1063 	struct ifnet *ifp;
1064 {
1065 	struct in_multi *inm;
1066 	struct ifreq ifr;
1067 	int s = splsoftnet();
1068 
1069 	/*
1070 	 * See if address already in list.
1071 	 */
1072 	IN_LOOKUP_MULTI(*ap, ifp, inm);
1073 	if (inm != NULL) {
1074 		/*
1075 		 * Found it; just increment the reference count.
1076 		 */
1077 		++inm->inm_refcount;
1078 	} else {
1079 		/*
1080 		 * New address; allocate a new multicast record
1081 		 * and link it into the interface's multicast list.
1082 		 */
1083 		inm = pool_get(&inmulti_pool, PR_NOWAIT);
1084 		if (inm == NULL) {
1085 			splx(s);
1086 			return (NULL);
1087 		}
1088 		inm->inm_addr = *ap;
1089 		inm->inm_ifp = ifp;
1090 		inm->inm_refcount = 1;
1091 		LIST_INSERT_HEAD(
1092 		    &IN_MULTI_HASH(inm->inm_addr.s_addr, ifp),
1093 		    inm, inm_list);
1094 		/*
1095 		 * Ask the network driver to update its multicast reception
1096 		 * filter appropriately for the new address.
1097 		 */
1098 		satosin(&ifr.ifr_addr)->sin_len = sizeof(struct sockaddr_in);
1099 		satosin(&ifr.ifr_addr)->sin_family = AF_INET;
1100 		satosin(&ifr.ifr_addr)->sin_addr = *ap;
1101 		if ((ifp->if_ioctl == NULL) ||
1102 		    (*ifp->if_ioctl)(ifp, SIOCADDMULTI,(caddr_t)&ifr) != 0) {
1103 			LIST_REMOVE(inm, inm_list);
1104 			pool_put(&inmulti_pool, inm);
1105 			splx(s);
1106 			return (NULL);
1107 		}
1108 		/*
1109 		 * Let IGMP know that we have joined a new IP multicast group.
1110 		 */
1111 		if (igmp_joingroup(inm) != 0) {
1112 			LIST_REMOVE(inm, inm_list);
1113 			pool_put(&inmulti_pool, inm);
1114 			splx(s);
1115 			return (NULL);
1116 		}
1117 		in_multientries++;
1118 	}
1119 	splx(s);
1120 	return (inm);
1121 }
1122 
1123 /*
1124  * Delete a multicast address record.
1125  */
1126 void
1127 in_delmulti(inm)
1128 	struct in_multi *inm;
1129 {
1130 	struct ifreq ifr;
1131 	int s = splsoftnet();
1132 
1133 	if (--inm->inm_refcount == 0) {
1134 		/*
1135 		 * No remaining claims to this record; let IGMP know that
1136 		 * we are leaving the multicast group.
1137 		 */
1138 		igmp_leavegroup(inm);
1139 		/*
1140 		 * Unlink from list.
1141 		 */
1142 		LIST_REMOVE(inm, inm_list);
1143 		in_multientries--;
1144 		/*
1145 		 * Notify the network driver to update its multicast reception
1146 		 * filter.
1147 		 */
1148 		satosin(&ifr.ifr_addr)->sin_family = AF_INET;
1149 		satosin(&ifr.ifr_addr)->sin_addr = inm->inm_addr;
1150 		(*inm->inm_ifp->if_ioctl)(inm->inm_ifp, SIOCDELMULTI,
1151 							     (caddr_t)&ifr);
1152 		pool_put(&inmulti_pool, inm);
1153 	}
1154 	splx(s);
1155 }
1156 #endif
1157