xref: /netbsd-src/sys/netinet/in.c (revision 5b84b3983f71fd20a534cfa5d1556623a8aaa717)
1 /*	$NetBSD: in.c,v 1.104 2005/02/26 22:45:12 perry 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 1.104 2005/02/26 22:45:12 perry 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/systm.h>
115 #include <sys/proc.h>
116 #include <sys/syslog.h>
117 
118 #include <net/if.h>
119 #include <net/route.h>
120 
121 #include <net/if_ether.h>
122 
123 #include <netinet/in_systm.h>
124 #include <netinet/in.h>
125 #include <netinet/in_var.h>
126 #include <netinet/ip.h>
127 #include <netinet/ip_var.h>
128 #include <netinet/in_pcb.h>
129 #include <netinet/if_inarp.h>
130 #include <netinet/ip_mroute.h>
131 #include <netinet/igmp_var.h>
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, caddr_t,
141 	struct ifnet *, struct proc *);
142 
143 static int in_addprefix(struct in_ifaddr *, int);
144 static int in_scrubprefix(struct in_ifaddr *);
145 
146 #ifndef SUBNETSARELOCAL
147 #define	SUBNETSARELOCAL	1
148 #endif
149 
150 #ifndef HOSTZEROBROADCAST
151 #define HOSTZEROBROADCAST 1
152 #endif
153 
154 int subnetsarelocal = SUBNETSARELOCAL;
155 int hostzeroisbroadcast = HOSTZEROBROADCAST;
156 
157 /*
158  * This list is used to keep track of in_multi chains which belong to
159  * deleted interface addresses.  We use in_ifaddr so that a chain head
160  * won't be deallocated until all multicast address record are deleted.
161  */
162 static TAILQ_HEAD(, in_ifaddr) in_mk = TAILQ_HEAD_INITIALIZER(in_mk);
163 
164 /*
165  * Return 1 if an internet address is for a ``local'' host
166  * (one to which we have a connection).  If subnetsarelocal
167  * is true, this includes other subnets of the local net.
168  * Otherwise, it includes only the directly-connected (sub)nets.
169  */
170 int
171 in_localaddr(struct in_addr in)
172 {
173 	struct in_ifaddr *ia;
174 
175 	if (subnetsarelocal) {
176 		TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list)
177 			if ((in.s_addr & ia->ia_netmask) == ia->ia_net)
178 				return (1);
179 	} else {
180 		TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list)
181 			if ((in.s_addr & ia->ia_subnetmask) == ia->ia_subnet)
182 				return (1);
183 	}
184 	return (0);
185 }
186 
187 /*
188  * Determine whether an IP address is in a reserved set of addresses
189  * that may not be forwarded, or whether datagrams to that destination
190  * may be forwarded.
191  */
192 int
193 in_canforward(struct in_addr in)
194 {
195 	u_int32_t net;
196 
197 	if (IN_EXPERIMENTAL(in.s_addr) || IN_MULTICAST(in.s_addr))
198 		return (0);
199 	if (IN_CLASSA(in.s_addr)) {
200 		net = in.s_addr & IN_CLASSA_NET;
201 		if (net == 0 || net == htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
202 			return (0);
203 	}
204 	return (1);
205 }
206 
207 /*
208  * Trim a mask in a sockaddr
209  */
210 void
211 in_socktrim(struct sockaddr_in *ap)
212 {
213 	char *cplim = (char *) &ap->sin_addr;
214 	char *cp = (char *) (&ap->sin_addr + 1);
215 
216 	ap->sin_len = 0;
217 	while (--cp >= cplim)
218 		if (*cp) {
219 			(ap)->sin_len = cp - (char *) (ap) + 1;
220 			break;
221 		}
222 }
223 
224 /*
225  *  Routine to take an Internet address and convert into a
226  *  "dotted quad" representation for printing.
227  */
228 const char *
229 in_fmtaddr(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 	snprintf(buf, sizeof(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(void)
252 {
253 	struct in_ifaddr *ia;
254 	struct ifnet *ifp;
255 	unsigned long maxmtu = 0;
256 
257 	TAILQ_FOREACH(ia, &in_ifaddrhead, 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(struct in_addr *mask)
271 {
272 	u_int x, y;
273 	u_char *p;
274 
275 	p = (u_char *)mask;
276 	for (x = 0; x < sizeof(*mask); x++) {
277 		if (p[x] != 0xff)
278 			break;
279 	}
280 	y = 0;
281 	if (x < sizeof(*mask)) {
282 		for (y = 0; y < 8; y++) {
283 			if ((p[x] & (0x80 >> y)) == 0)
284 				break;
285 		}
286 	}
287 	return x * 8 + y;
288 }
289 
290 static void
291 in_len2mask(struct in_addr *mask, u_int len)
292 {
293 	u_int i;
294 	u_char *p;
295 
296 	p = (u_char *)mask;
297 	bzero(mask, sizeof(*mask));
298 	for (i = 0; i < len / 8; i++)
299 		p[i] = 0xff;
300 	if (len % 8)
301 		p[i] = (0xff00 >> (len % 8)) & 0xff;
302 }
303 
304 /*
305  * Generic internet control operations (ioctl's).
306  * Ifp is 0 if not an interface-specific ioctl.
307  */
308 /* ARGSUSED */
309 int
310 in_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
311     struct proc *p)
312 {
313 	struct ifreq *ifr = (struct ifreq *)data;
314 	struct in_ifaddr *ia = 0;
315 	struct in_aliasreq *ifra = (struct in_aliasreq *)data;
316 	struct sockaddr_in oldaddr;
317 	int error, hostIsNew, maskIsNew;
318 	int newifaddr = 0;
319 
320 	switch (cmd) {
321 	case SIOCALIFADDR:
322 	case SIOCDLIFADDR:
323 		if (p == 0 || (error = suser(p->p_ucred, &p->p_acflag)))
324 			return (EPERM);
325 		/*fall through*/
326 	case SIOCGLIFADDR:
327 		if (!ifp)
328 			return EINVAL;
329 		return in_lifaddr_ioctl(so, cmd, data, ifp, p);
330 	}
331 
332 	/*
333 	 * Find address for this interface, if it exists.
334 	 */
335 	if (ifp)
336 		IFP_TO_IA(ifp, ia);
337 
338 	switch (cmd) {
339 
340 	case SIOCAIFADDR:
341 	case SIOCDIFADDR:
342 	case SIOCGIFALIAS:
343 		if (ifra->ifra_addr.sin_family == AF_INET)
344 			LIST_FOREACH(ia,
345 			    &IN_IFADDR_HASH(ifra->ifra_addr.sin_addr.s_addr),
346 			    ia_hash) {
347 				if (ia->ia_ifp == ifp  &&
348 				    in_hosteq(ia->ia_addr.sin_addr,
349 				    ifra->ifra_addr.sin_addr))
350 					break;
351 			}
352 		if (cmd == SIOCDIFADDR) {
353 			if (ia == 0)
354 				return (EADDRNOTAVAIL);
355 #if 1 /*def COMPAT_43*/
356 			if (ifra->ifra_addr.sin_family == AF_UNSPEC)
357 				ifra->ifra_addr.sin_family = AF_INET;
358 #endif
359 		}
360 		/* FALLTHROUGH */
361 	case SIOCSIFADDR:
362 	case SIOCSIFDSTADDR:
363 		if (ifra->ifra_addr.sin_family != AF_INET)
364 			return (EAFNOSUPPORT);
365 		/* FALLTHROUGH */
366 	case SIOCSIFNETMASK:
367 		if (ifp == 0)
368 			panic("in_control");
369 
370 		if (cmd == SIOCGIFALIAS)
371 			break;
372 
373 		if (ia == NULL &&
374 		    (cmd == SIOCSIFNETMASK || cmd == SIOCSIFDSTADDR))
375 			return (EADDRNOTAVAIL);
376 
377 		if (p == 0 || (error = suser(p->p_ucred, &p->p_acflag)))
378 			return (EPERM);
379 
380 		if (ia == 0) {
381 			MALLOC(ia, struct in_ifaddr *, sizeof(*ia),
382 			       M_IFADDR, M_WAITOK);
383 			if (ia == 0)
384 				return (ENOBUFS);
385 			bzero((caddr_t)ia, sizeof *ia);
386 			TAILQ_INSERT_TAIL(&in_ifaddrhead, ia, ia_list);
387 			IFAREF(&ia->ia_ifa);
388 			TAILQ_INSERT_TAIL(&ifp->if_addrlist, &ia->ia_ifa,
389 			    ifa_list);
390 			IFAREF(&ia->ia_ifa);
391 			ia->ia_ifa.ifa_addr = sintosa(&ia->ia_addr);
392 			ia->ia_ifa.ifa_dstaddr = sintosa(&ia->ia_dstaddr);
393 			ia->ia_ifa.ifa_netmask = sintosa(&ia->ia_sockmask);
394 			ia->ia_sockmask.sin_len = 8;
395 			if (ifp->if_flags & IFF_BROADCAST) {
396 				ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr);
397 				ia->ia_broadaddr.sin_family = AF_INET;
398 			}
399 			ia->ia_ifp = ifp;
400 			LIST_INIT(&ia->ia_multiaddrs);
401 			newifaddr = 1;
402 		}
403 		break;
404 
405 	case SIOCSIFBRDADDR:
406 		if (p == 0 || (error = suser(p->p_ucred, &p->p_acflag)))
407 			return (EPERM);
408 		/* FALLTHROUGH */
409 
410 	case SIOCGIFADDR:
411 	case SIOCGIFNETMASK:
412 	case SIOCGIFDSTADDR:
413 	case SIOCGIFBRDADDR:
414 		if (ia == 0)
415 			return (EADDRNOTAVAIL);
416 		break;
417 	}
418 	error = 0;
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 #ifdef PFIL_HOOKS
468 		if (!error)
469 			(void)pfil_run_hooks(&if_pfil,
470 			    (struct mbuf **)SIOCSIFADDR, ifp, PFIL_IFADDR);
471 #endif
472 		break;
473 
474 	case SIOCSIFNETMASK:
475 		in_ifscrub(ifp, ia);
476 		ia->ia_sockmask = *satosin(&ifr->ifr_addr);
477 		ia->ia_subnetmask = ia->ia_sockmask.sin_addr.s_addr;
478 		error = in_ifinit(ifp, ia, NULL, 0);
479 		break;
480 
481 	case SIOCAIFADDR:
482 		maskIsNew = 0;
483 		hostIsNew = 1;
484 		if (ia->ia_addr.sin_family == AF_INET) {
485 			if (ifra->ifra_addr.sin_len == 0) {
486 				ifra->ifra_addr = ia->ia_addr;
487 				hostIsNew = 0;
488 			} else if (in_hosteq(ia->ia_addr.sin_addr, ifra->ifra_addr.sin_addr))
489 				hostIsNew = 0;
490 		}
491 		if (ifra->ifra_mask.sin_len) {
492 			in_ifscrub(ifp, ia);
493 			ia->ia_sockmask = ifra->ifra_mask;
494 			ia->ia_subnetmask = ia->ia_sockmask.sin_addr.s_addr;
495 			maskIsNew = 1;
496 		}
497 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
498 		    (ifra->ifra_dstaddr.sin_family == AF_INET)) {
499 			in_ifscrub(ifp, ia);
500 			ia->ia_dstaddr = ifra->ifra_dstaddr;
501 			maskIsNew  = 1; /* We lie; but the effect's the same */
502 		}
503 		if (ifra->ifra_addr.sin_family == AF_INET &&
504 		    (hostIsNew || maskIsNew)) {
505 			error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
506 		}
507 		if ((ifp->if_flags & IFF_BROADCAST) &&
508 		    (ifra->ifra_broadaddr.sin_family == AF_INET))
509 			ia->ia_broadaddr = ifra->ifra_broadaddr;
510 #ifdef PFIL_HOOKS
511 		if (!error)
512 			(void)pfil_run_hooks(&if_pfil,
513 			    (struct mbuf **)SIOCAIFADDR, ifp, PFIL_IFADDR);
514 #endif
515 		break;
516 
517 	case SIOCGIFALIAS:
518 		ifra->ifra_mask = ia->ia_sockmask;
519 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
520 		    (ia->ia_dstaddr.sin_family == AF_INET))
521 			ifra->ifra_dstaddr = ia->ia_dstaddr;
522 		else if ((ifp->if_flags & IFF_BROADCAST) &&
523 		    (ia->ia_broadaddr.sin_family == AF_INET))
524 			ifra->ifra_broadaddr = ia->ia_broadaddr;
525 		else
526 			bzero(&ifra->ifra_broadaddr,
527 			      sizeof(ifra->ifra_broadaddr));
528 		break;
529 
530 	case SIOCDIFADDR:
531 		in_purgeaddr(&ia->ia_ifa, ifp);
532 #ifdef PFIL_HOOKS
533 		(void)pfil_run_hooks(&if_pfil, (struct mbuf **)SIOCDIFADDR,
534 		    ifp, PFIL_IFADDR);
535 #endif
536 		break;
537 
538 #ifdef MROUTING
539 	case SIOCGETVIFCNT:
540 	case SIOCGETSGCNT:
541 		error = mrt_ioctl(so, cmd, data);
542 		break;
543 #endif /* MROUTING */
544 
545 	default:
546 		if (ifp == 0 || ifp->if_ioctl == 0)
547 			return (EOPNOTSUPP);
548 		error = (*ifp->if_ioctl)(ifp, cmd, data);
549 		in_setmaxmtu();
550 		break;
551 	}
552 
553 	if (error && newifaddr) {
554 		KASSERT(ia != NULL);
555 		in_purgeaddr(&ia->ia_ifa, ifp);
556 	}
557 
558 	return error;
559 }
560 
561 void
562 in_purgeaddr(struct ifaddr *ifa, struct ifnet *ifp)
563 {
564 	struct in_ifaddr *ia = (void *) ifa;
565 
566 	in_ifscrub(ifp, ia);
567 	LIST_REMOVE(ia, ia_hash);
568 	TAILQ_REMOVE(&ifp->if_addrlist, &ia->ia_ifa, ifa_list);
569 	IFAFREE(&ia->ia_ifa);
570 	TAILQ_REMOVE(&in_ifaddrhead, ia, ia_list);
571 	if (ia->ia_allhosts != NULL)
572 		in_delmulti(ia->ia_allhosts);
573 	IFAFREE(&ia->ia_ifa);
574 	in_setmaxmtu();
575 }
576 
577 void
578 in_purgeif(struct ifnet *ifp)
579 {
580 	struct ifaddr *ifa, *nifa;
581 
582 	for (ifa = TAILQ_FIRST(&ifp->if_addrlist); ifa != NULL; ifa = nifa) {
583 		nifa = TAILQ_NEXT(ifa, ifa_list);
584 		if (ifa->ifa_addr->sa_family != AF_INET)
585 			continue;
586 		in_purgeaddr(ifa, ifp);
587 	}
588 
589 	igmp_purgeif(ifp);
590 #ifdef MROUTING
591 	ip_mrouter_detach(ifp);
592 #endif
593 }
594 
595 /*
596  * SIOC[GAD]LIFADDR.
597  *	SIOCGLIFADDR: get first address. (???)
598  *	SIOCGLIFADDR with IFLR_PREFIX:
599  *		get first address that matches the specified prefix.
600  *	SIOCALIFADDR: add the specified address.
601  *	SIOCALIFADDR with IFLR_PREFIX:
602  *		EINVAL since we can't deduce hostid part of the address.
603  *	SIOCDLIFADDR: delete the specified address.
604  *	SIOCDLIFADDR with IFLR_PREFIX:
605  *		delete the first address that matches the specified prefix.
606  * return values:
607  *	EINVAL on invalid parameters
608  *	EADDRNOTAVAIL on prefix match failed/specified address not found
609  *	other values may be returned from in_ioctl()
610  */
611 static int
612 in_lifaddr_ioctl(struct socket *so, u_long cmd, caddr_t data,
613     struct ifnet *ifp, struct proc *p)
614 {
615 	struct if_laddrreq *iflr = (struct if_laddrreq *)data;
616 	struct ifaddr *ifa;
617 	struct sockaddr *sa;
618 
619 	/* sanity checks */
620 	if (!data || !ifp) {
621 		panic("invalid argument to in_lifaddr_ioctl");
622 		/*NOTRECHED*/
623 	}
624 
625 	switch (cmd) {
626 	case SIOCGLIFADDR:
627 		/* address must be specified on GET with IFLR_PREFIX */
628 		if ((iflr->flags & IFLR_PREFIX) == 0)
629 			break;
630 		/*FALLTHROUGH*/
631 	case SIOCALIFADDR:
632 	case SIOCDLIFADDR:
633 		/* address must be specified on ADD and DELETE */
634 		sa = (struct sockaddr *)&iflr->addr;
635 		if (sa->sa_family != AF_INET)
636 			return EINVAL;
637 		if (sa->sa_len != sizeof(struct sockaddr_in))
638 			return EINVAL;
639 		/* XXX need improvement */
640 		sa = (struct sockaddr *)&iflr->dstaddr;
641 		if (sa->sa_family
642 		 && sa->sa_family != AF_INET)
643 			return EINVAL;
644 		if (sa->sa_len && sa->sa_len != sizeof(struct sockaddr_in))
645 			return EINVAL;
646 		break;
647 	default: /*shouldn't happen*/
648 #if 0
649 		panic("invalid cmd to in_lifaddr_ioctl");
650 		/*NOTREACHED*/
651 #else
652 		return EOPNOTSUPP;
653 #endif
654 	}
655 	if (sizeof(struct in_addr) * 8 < iflr->prefixlen)
656 		return EINVAL;
657 
658 	switch (cmd) {
659 	case SIOCALIFADDR:
660 	    {
661 		struct in_aliasreq ifra;
662 
663 		if (iflr->flags & IFLR_PREFIX)
664 			return EINVAL;
665 
666 		/* copy args to in_aliasreq, perform ioctl(SIOCAIFADDR_IN). */
667 		bzero(&ifra, sizeof(ifra));
668 		bcopy(iflr->iflr_name, ifra.ifra_name,
669 			sizeof(ifra.ifra_name));
670 
671 		bcopy(&iflr->addr, &ifra.ifra_addr,
672 			((struct sockaddr *)&iflr->addr)->sa_len);
673 
674 		if (((struct sockaddr *)&iflr->dstaddr)->sa_family) {	/*XXX*/
675 			bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
676 				((struct sockaddr *)&iflr->dstaddr)->sa_len);
677 		}
678 
679 		ifra.ifra_mask.sin_family = AF_INET;
680 		ifra.ifra_mask.sin_len = sizeof(struct sockaddr_in);
681 		in_len2mask(&ifra.ifra_mask.sin_addr, iflr->prefixlen);
682 
683 		return in_control(so, SIOCAIFADDR, (caddr_t)&ifra, ifp, p);
684 	    }
685 	case SIOCGLIFADDR:
686 	case SIOCDLIFADDR:
687 	    {
688 		struct in_ifaddr *ia;
689 		struct in_addr mask, candidate, match;
690 		struct sockaddr_in *sin;
691 		int cmp;
692 
693 		bzero(&mask, sizeof(mask));
694 		if (iflr->flags & IFLR_PREFIX) {
695 			/* lookup a prefix rather than address. */
696 			in_len2mask(&mask, iflr->prefixlen);
697 
698 			sin = (struct sockaddr_in *)&iflr->addr;
699 			match.s_addr = sin->sin_addr.s_addr;
700 			match.s_addr &= mask.s_addr;
701 
702 			/* if you set extra bits, that's wrong */
703 			if (match.s_addr != sin->sin_addr.s_addr)
704 				return EINVAL;
705 
706 			cmp = 1;
707 		} else {
708 			if (cmd == SIOCGLIFADDR) {
709 				/* on getting an address, take the 1st match */
710 				cmp = 0;	/*XXX*/
711 			} else {
712 				/* on deleting an address, do exact match */
713 				in_len2mask(&mask, 32);
714 				sin = (struct sockaddr_in *)&iflr->addr;
715 				match.s_addr = sin->sin_addr.s_addr;
716 
717 				cmp = 1;
718 			}
719 		}
720 
721 		IFADDR_FOREACH(ifa, ifp) {
722 			if (ifa->ifa_addr->sa_family != AF_INET)
723 				continue;
724 			if (!cmp)
725 				break;
726 			candidate.s_addr = ((struct sockaddr_in *)&ifa->ifa_addr)->sin_addr.s_addr;
727 			candidate.s_addr &= mask.s_addr;
728 			if (candidate.s_addr == match.s_addr)
729 				break;
730 		}
731 		if (!ifa)
732 			return EADDRNOTAVAIL;
733 		ia = (struct in_ifaddr *)ifa;
734 
735 		if (cmd == SIOCGLIFADDR) {
736 			/* fill in the if_laddrreq structure */
737 			bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin_len);
738 
739 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
740 				bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
741 					ia->ia_dstaddr.sin_len);
742 			} else
743 				bzero(&iflr->dstaddr, sizeof(iflr->dstaddr));
744 
745 			iflr->prefixlen =
746 				in_mask2len(&ia->ia_sockmask.sin_addr);
747 
748 			iflr->flags = 0;	/*XXX*/
749 
750 			return 0;
751 		} else {
752 			struct in_aliasreq ifra;
753 
754 			/* fill in_aliasreq and do ioctl(SIOCDIFADDR_IN) */
755 			bzero(&ifra, sizeof(ifra));
756 			bcopy(iflr->iflr_name, ifra.ifra_name,
757 				sizeof(ifra.ifra_name));
758 
759 			bcopy(&ia->ia_addr, &ifra.ifra_addr,
760 				ia->ia_addr.sin_len);
761 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
762 				bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
763 					ia->ia_dstaddr.sin_len);
764 			}
765 			bcopy(&ia->ia_sockmask, &ifra.ifra_dstaddr,
766 				ia->ia_sockmask.sin_len);
767 
768 			return in_control(so, SIOCDIFADDR, (caddr_t)&ifra,
769 				ifp, p);
770 		}
771 	    }
772 	}
773 
774 	return EOPNOTSUPP;	/*just for safety*/
775 }
776 
777 /*
778  * Delete any existing route for an interface.
779  */
780 void
781 in_ifscrub(struct ifnet *ifp, struct in_ifaddr *ia)
782 {
783 
784 	in_scrubprefix(ia);
785 }
786 
787 /*
788  * Initialize an interface's internet address
789  * and routing table entry.
790  */
791 int
792 in_ifinit(struct ifnet *ifp, struct in_ifaddr *ia,
793     struct sockaddr_in *sin, int scrub)
794 {
795 	u_int32_t i;
796 	struct sockaddr_in oldaddr;
797 	int s = splnet(), flags = RTF_UP, error;
798 
799 	if (!sin)
800 		sin = &ia->ia_addr;
801 
802 	/*
803 	 * Set up new addresses.
804 	 */
805 	oldaddr = ia->ia_addr;
806 	if (ia->ia_addr.sin_family == AF_INET)
807 		LIST_REMOVE(ia, ia_hash);
808 	ia->ia_addr = *sin;
809 	LIST_INSERT_HEAD(&IN_IFADDR_HASH(ia->ia_addr.sin_addr.s_addr), ia, ia_hash);
810 
811 	/*
812 	 * Give the interface a chance to initialize
813 	 * if this is its first address,
814 	 * and to validate the address if necessary.
815 	 */
816 	if (ifp->if_ioctl &&
817 	    (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia)))
818 		goto bad;
819 	splx(s);
820 	if (scrub) {
821 		ia->ia_ifa.ifa_addr = sintosa(&oldaddr);
822 		in_ifscrub(ifp, ia);
823 		ia->ia_ifa.ifa_addr = sintosa(&ia->ia_addr);
824 	}
825 
826 	i = ia->ia_addr.sin_addr.s_addr;
827 	if (IN_CLASSA(i))
828 		ia->ia_netmask = IN_CLASSA_NET;
829 	else if (IN_CLASSB(i))
830 		ia->ia_netmask = IN_CLASSB_NET;
831 	else
832 		ia->ia_netmask = IN_CLASSC_NET;
833 	/*
834 	 * The subnet mask usually includes at least the standard network part,
835 	 * but may may be smaller in the case of supernetting.
836 	 * If it is set, we believe it.
837 	 */
838 	if (ia->ia_subnetmask == 0) {
839 		ia->ia_subnetmask = ia->ia_netmask;
840 		ia->ia_sockmask.sin_addr.s_addr = ia->ia_subnetmask;
841 	} else
842 		ia->ia_netmask &= ia->ia_subnetmask;
843 
844 	ia->ia_net = i & ia->ia_netmask;
845 	ia->ia_subnet = i & ia->ia_subnetmask;
846 	in_socktrim(&ia->ia_sockmask);
847 	/* re-calculate the "in_maxmtu" value */
848 	in_setmaxmtu();
849 	/*
850 	 * Add route for the network.
851 	 */
852 	ia->ia_ifa.ifa_metric = ifp->if_metric;
853 	if (ifp->if_flags & IFF_BROADCAST) {
854 		ia->ia_broadaddr.sin_addr.s_addr =
855 			ia->ia_subnet | ~ia->ia_subnetmask;
856 		ia->ia_netbroadcast.s_addr =
857 			ia->ia_net | ~ia->ia_netmask;
858 	} else if (ifp->if_flags & IFF_LOOPBACK) {
859 		ia->ia_dstaddr = ia->ia_addr;
860 		flags |= RTF_HOST;
861 	} else if (ifp->if_flags & IFF_POINTOPOINT) {
862 		if (ia->ia_dstaddr.sin_family != AF_INET)
863 			return (0);
864 		flags |= RTF_HOST;
865 	}
866 	error = in_addprefix(ia, flags);
867 	/*
868 	 * If the interface supports multicast, join the "all hosts"
869 	 * multicast group on that interface.
870 	 */
871 	if ((ifp->if_flags & IFF_MULTICAST) != 0 && ia->ia_allhosts == NULL) {
872 		struct in_addr addr;
873 
874 		addr.s_addr = INADDR_ALLHOSTS_GROUP;
875 		ia->ia_allhosts = in_addmulti(&addr, ifp);
876 	}
877 	return (error);
878 bad:
879 	splx(s);
880 	LIST_REMOVE(ia, ia_hash);
881 	ia->ia_addr = oldaddr;
882 	if (ia->ia_addr.sin_family == AF_INET)
883 		LIST_INSERT_HEAD(&IN_IFADDR_HASH(ia->ia_addr.sin_addr.s_addr),
884 		    ia, ia_hash);
885 	return (error);
886 }
887 
888 #define rtinitflags(x) \
889 	((((x)->ia_ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) != 0) \
890 	    ? RTF_HOST : 0)
891 
892 /*
893  * add a route to prefix ("connected route" in cisco terminology).
894  * does nothing if there's some interface address with the same prefix already.
895  */
896 static int
897 in_addprefix(struct in_ifaddr *target, int flags)
898 {
899 	struct in_ifaddr *ia;
900 	struct in_addr prefix, mask, p;
901 	int error;
902 
903 	if ((flags & RTF_HOST) != 0)
904 		prefix = target->ia_dstaddr.sin_addr;
905 	else {
906 		prefix = target->ia_addr.sin_addr;
907 		mask = target->ia_sockmask.sin_addr;
908 		prefix.s_addr &= mask.s_addr;
909 	}
910 
911 	TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list) {
912 		if (rtinitflags(ia))
913 			p = ia->ia_dstaddr.sin_addr;
914 		else {
915 			p = ia->ia_addr.sin_addr;
916 			p.s_addr &= ia->ia_sockmask.sin_addr.s_addr;
917 		}
918 
919 		if (prefix.s_addr != p.s_addr)
920 			continue;
921 
922 		/*
923 		 * if we got a matching prefix route inserted by other
924 		 * interface address, we don't need to bother
925 		 */
926 		if (ia->ia_flags & IFA_ROUTE)
927 			return 0;
928 	}
929 
930 	/*
931 	 * noone seem to have prefix route.  insert it.
932 	 */
933 	error = rtinit(&target->ia_ifa, (int)RTM_ADD, flags);
934 	if (!error)
935 		target->ia_flags |= IFA_ROUTE;
936 	return error;
937 }
938 
939 /*
940  * remove a route to prefix ("connected route" in cisco terminology).
941  * re-installs the route by using another interface address, if there's one
942  * with the same prefix (otherwise we lose the route mistakenly).
943  */
944 static int
945 in_scrubprefix(struct in_ifaddr *target)
946 {
947 	struct in_ifaddr *ia;
948 	struct in_addr prefix, mask, p;
949 	int error;
950 
951 	if ((target->ia_flags & IFA_ROUTE) == 0)
952 		return 0;
953 
954 	if (rtinitflags(target))
955 		prefix = target->ia_dstaddr.sin_addr;
956 	else {
957 		prefix = target->ia_addr.sin_addr;
958 		mask = target->ia_sockmask.sin_addr;
959 		prefix.s_addr &= mask.s_addr;
960 	}
961 
962 	TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list) {
963 		if (rtinitflags(ia))
964 			p = ia->ia_dstaddr.sin_addr;
965 		else {
966 			p = ia->ia_addr.sin_addr;
967 			p.s_addr &= ia->ia_sockmask.sin_addr.s_addr;
968 		}
969 
970 		if (prefix.s_addr != p.s_addr)
971 			continue;
972 
973 		/*
974 		 * if we got a matching prefix route, move IFA_ROUTE to him
975 		 */
976 		if ((ia->ia_flags & IFA_ROUTE) == 0) {
977 			rtinit(&(target->ia_ifa), (int)RTM_DELETE,
978 			    rtinitflags(target));
979 			target->ia_flags &= ~IFA_ROUTE;
980 
981 			error = rtinit(&ia->ia_ifa, (int)RTM_ADD,
982 			    rtinitflags(ia) | RTF_UP);
983 			if (error == 0)
984 				ia->ia_flags |= IFA_ROUTE;
985 			return error;
986 		}
987 	}
988 
989 	/*
990 	 * noone seem to have prefix route.  remove it.
991 	 */
992 	rtinit(&(target->ia_ifa), (int)RTM_DELETE, rtinitflags(target));
993 	target->ia_flags &= ~IFA_ROUTE;
994 	return 0;
995 }
996 
997 #undef rtinitflags
998 
999 /*
1000  * Return 1 if the address might be a local broadcast address.
1001  */
1002 int
1003 in_broadcast(struct in_addr in, struct ifnet *ifp)
1004 {
1005 	struct ifaddr *ifa;
1006 
1007 	if (in.s_addr == INADDR_BROADCAST ||
1008 	    in_nullhost(in))
1009 		return 1;
1010 	if ((ifp->if_flags & IFF_BROADCAST) == 0)
1011 		return 0;
1012 	/*
1013 	 * Look through the list of addresses for a match
1014 	 * with a broadcast address.
1015 	 */
1016 #define ia (ifatoia(ifa))
1017 	IFADDR_FOREACH(ifa, ifp)
1018 		if (ifa->ifa_addr->sa_family == AF_INET &&
1019 		    !in_hosteq(in, ia->ia_addr.sin_addr) &&
1020 		    (in_hosteq(in, ia->ia_broadaddr.sin_addr) ||
1021 		     in_hosteq(in, ia->ia_netbroadcast) ||
1022 		     (hostzeroisbroadcast &&
1023 		      /*
1024 		       * Check for old-style (host 0) broadcast.
1025 		       */
1026 		      (in.s_addr == ia->ia_subnet ||
1027 		       in.s_addr == ia->ia_net))))
1028 			return 1;
1029 	return (0);
1030 #undef ia
1031 }
1032 
1033 /*
1034  * Add an address to the list of IP multicast addresses for a given interface.
1035  */
1036 struct in_multi *
1037 in_addmulti(struct in_addr *ap, struct ifnet *ifp)
1038 {
1039 	struct in_multi *inm;
1040 	struct ifreq ifr;
1041 	int s = splsoftnet();
1042 
1043 	/*
1044 	 * See if address already in list.
1045 	 */
1046 	IN_LOOKUP_MULTI(*ap, ifp, inm);
1047 	if (inm != NULL) {
1048 		/*
1049 		 * Found it; just increment the reference count.
1050 		 */
1051 		++inm->inm_refcount;
1052 	} else {
1053 		/*
1054 		 * New address; allocate a new multicast record
1055 		 * and link it into the interface's multicast list.
1056 		 */
1057 		inm = pool_get(&inmulti_pool, PR_NOWAIT);
1058 		if (inm == NULL) {
1059 			splx(s);
1060 			return (NULL);
1061 		}
1062 		inm->inm_addr = *ap;
1063 		inm->inm_ifp = ifp;
1064 		inm->inm_refcount = 1;
1065 		LIST_INSERT_HEAD(
1066 		    &IN_MULTI_HASH(inm->inm_addr.s_addr, ifp),
1067 		    inm, inm_list);
1068 		/*
1069 		 * Ask the network driver to update its multicast reception
1070 		 * filter appropriately for the new address.
1071 		 */
1072 		satosin(&ifr.ifr_addr)->sin_len = sizeof(struct sockaddr_in);
1073 		satosin(&ifr.ifr_addr)->sin_family = AF_INET;
1074 		satosin(&ifr.ifr_addr)->sin_addr = *ap;
1075 		if ((ifp->if_ioctl == NULL) ||
1076 		    (*ifp->if_ioctl)(ifp, SIOCADDMULTI,(caddr_t)&ifr) != 0) {
1077 			LIST_REMOVE(inm, inm_list);
1078 			pool_put(&inmulti_pool, inm);
1079 			splx(s);
1080 			return (NULL);
1081 		}
1082 		/*
1083 		 * Let IGMP know that we have joined a new IP multicast group.
1084 		 */
1085 		if (igmp_joingroup(inm) != 0) {
1086 			LIST_REMOVE(inm, inm_list);
1087 			pool_put(&inmulti_pool, inm);
1088 			splx(s);
1089 			return (NULL);
1090 		}
1091 		in_multientries++;
1092 	}
1093 	splx(s);
1094 	return (inm);
1095 }
1096 
1097 /*
1098  * Delete a multicast address record.
1099  */
1100 void
1101 in_delmulti(struct in_multi *inm)
1102 {
1103 	struct ifreq ifr;
1104 	int s = splsoftnet();
1105 
1106 	if (--inm->inm_refcount == 0) {
1107 		/*
1108 		 * No remaining claims to this record; let IGMP know that
1109 		 * we are leaving the multicast group.
1110 		 */
1111 		igmp_leavegroup(inm);
1112 		/*
1113 		 * Unlink from list.
1114 		 */
1115 		LIST_REMOVE(inm, inm_list);
1116 		in_multientries--;
1117 		/*
1118 		 * Notify the network driver to update its multicast reception
1119 		 * filter.
1120 		 */
1121 		satosin(&ifr.ifr_addr)->sin_family = AF_INET;
1122 		satosin(&ifr.ifr_addr)->sin_addr = inm->inm_addr;
1123 		(*inm->inm_ifp->if_ioctl)(inm->inm_ifp, SIOCDELMULTI,
1124 							     (caddr_t)&ifr);
1125 		pool_put(&inmulti_pool, inm);
1126 	}
1127 	splx(s);
1128 }
1129 #endif
1130