xref: /netbsd-src/sys/netinet/in.c (revision 5bbd2a12505d72a8177929a37b5cee489d0a1cfd)
1 /*	$NetBSD: in.c,v 1.143 2012/06/08 15:01:51 gdt 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 1.143 2012/06/08 15:01:51 gdt 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 <sys/cprng.h>
114 
115 #include <net/if.h>
116 #include <net/route.h>
117 
118 #include <net/if_ether.h>
119 
120 #include <netinet/in_systm.h>
121 #include <netinet/in.h>
122 #include <netinet/in_var.h>
123 #include <netinet/ip.h>
124 #include <netinet/ip_var.h>
125 #include <netinet/in_ifattach.h>
126 #include <netinet/in_pcb.h>
127 #include <netinet/if_inarp.h>
128 #include <netinet/ip_mroute.h>
129 #include <netinet/igmp_var.h>
130 
131 #ifdef IPSELSRC
132 #include <netinet/in_selsrc.h>
133 #endif
134 
135 #ifdef PFIL_HOOKS
136 #include <net/pfil.h>
137 #endif
138 
139 static u_int in_mask2len(struct in_addr *);
140 static void in_len2mask(struct in_addr *, u_int);
141 static int in_lifaddr_ioctl(struct socket *, u_long, void *,
142 	struct ifnet *, struct lwp *);
143 
144 static int in_addprefix(struct in_ifaddr *, int);
145 static int in_scrubprefix(struct in_ifaddr *);
146 
147 #ifndef SUBNETSARELOCAL
148 #define	SUBNETSARELOCAL	1
149 #endif
150 
151 #ifndef HOSTZEROBROADCAST
152 #define HOSTZEROBROADCAST 1
153 #endif
154 
155 int subnetsarelocal = SUBNETSARELOCAL;
156 int hostzeroisbroadcast = HOSTZEROBROADCAST;
157 
158 /*
159  * This list is used to keep track of in_multi chains which belong to
160  * deleted interface addresses.  We use in_ifaddr so that a chain head
161  * won't be deallocated until all multicast address record are deleted.
162  */
163 static TAILQ_HEAD(, in_ifaddr) in_mk = TAILQ_HEAD_INITIALIZER(in_mk);
164 
165 /*
166  * Return 1 if an internet address is for a ``local'' host
167  * (one to which we have a connection).  If subnetsarelocal
168  * is true, this includes other subnets of the local net.
169  * Otherwise, it includes only the directly-connected (sub)nets.
170  */
171 int
172 in_localaddr(struct in_addr in)
173 {
174 	struct in_ifaddr *ia;
175 
176 	if (subnetsarelocal) {
177 		TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list)
178 			if ((in.s_addr & ia->ia_netmask) == ia->ia_net)
179 				return (1);
180 	} else {
181 		TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list)
182 			if ((in.s_addr & ia->ia_subnetmask) == ia->ia_subnet)
183 				return (1);
184 	}
185 	return (0);
186 }
187 
188 /*
189  * Determine whether an IP address is in a reserved set of addresses
190  * that may not be forwarded, or whether datagrams to that destination
191  * may be forwarded.
192  */
193 int
194 in_canforward(struct in_addr in)
195 {
196 	u_int32_t net;
197 
198 	if (IN_EXPERIMENTAL(in.s_addr) || IN_MULTICAST(in.s_addr))
199 		return (0);
200 	if (IN_CLASSA(in.s_addr)) {
201 		net = in.s_addr & IN_CLASSA_NET;
202 		if (net == 0 || net == htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
203 			return (0);
204 	}
205 	return (1);
206 }
207 
208 /*
209  * Trim a mask in a sockaddr
210  */
211 void
212 in_socktrim(struct sockaddr_in *ap)
213 {
214 	char *cplim = (char *) &ap->sin_addr;
215 	char *cp = (char *) (&ap->sin_addr + 1);
216 
217 	ap->sin_len = 0;
218 	while (--cp >= cplim)
219 		if (*cp) {
220 			(ap)->sin_len = cp - (char *) (ap) + 1;
221 			break;
222 		}
223 }
224 
225 /*
226  *  Routine to take an Internet address and convert into a
227  *  "dotted quad" representation for printing.
228  */
229 const char *
230 in_fmtaddr(struct in_addr addr)
231 {
232 	static char buf[sizeof("123.456.789.123")];
233 
234 	addr.s_addr = ntohl(addr.s_addr);
235 
236 	snprintf(buf, sizeof(buf), "%d.%d.%d.%d",
237 		(addr.s_addr >> 24) & 0xFF,
238 		(addr.s_addr >> 16) & 0xFF,
239 		(addr.s_addr >>  8) & 0xFF,
240 		(addr.s_addr >>  0) & 0xFF);
241 	return buf;
242 }
243 
244 /*
245  * Maintain the "in_maxmtu" variable, which is the largest
246  * mtu for non-local interfaces with AF_INET addresses assigned
247  * to them that are up.
248  */
249 unsigned long in_maxmtu;
250 
251 void
252 in_setmaxmtu(void)
253 {
254 	struct in_ifaddr *ia;
255 	struct ifnet *ifp;
256 	unsigned long maxmtu = 0;
257 
258 	TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list) {
259 		if ((ifp = ia->ia_ifp) == 0)
260 			continue;
261 		if ((ifp->if_flags & (IFF_UP|IFF_LOOPBACK)) != IFF_UP)
262 			continue;
263 		if (ifp->if_mtu > maxmtu)
264 			maxmtu = ifp->if_mtu;
265 	}
266 	if (maxmtu)
267 		in_maxmtu = maxmtu;
268 }
269 
270 static u_int
271 in_mask2len(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 < NBBY; y++) {
284 			if ((p[x] & (0x80 >> y)) == 0)
285 				break;
286 		}
287 	}
288 	return x * NBBY + y;
289 }
290 
291 static void
292 in_len2mask(struct in_addr *mask, u_int len)
293 {
294 	u_int i;
295 	u_char *p;
296 
297 	p = (u_char *)mask;
298 	memset(mask, 0, sizeof(*mask));
299 	for (i = 0; i < len / NBBY; i++)
300 		p[i] = 0xff;
301 	if (len % NBBY)
302 		p[i] = (0xff00 >> (len % NBBY)) & 0xff;
303 }
304 
305 /*
306  * Generic internet control operations (ioctl's).
307  * Ifp is 0 if not an interface-specific ioctl.
308  */
309 /* ARGSUSED */
310 int
311 in_control(struct socket *so, u_long cmd, void *data, struct ifnet *ifp,
312     struct lwp *l)
313 {
314 	struct ifreq *ifr = (struct ifreq *)data;
315 	struct in_ifaddr *ia = NULL;
316 	struct in_aliasreq *ifra = (struct in_aliasreq *)data;
317 	struct sockaddr_in oldaddr;
318 	int error, hostIsNew, maskIsNew;
319 	int newifaddr = 0;
320 
321 	switch (cmd) {
322 	case SIOCALIFADDR:
323 	case SIOCDLIFADDR:
324 	case SIOCGLIFADDR:
325 		if (ifp == NULL)
326 			return EINVAL;
327 		return in_lifaddr_ioctl(so, cmd, data, ifp, l);
328 	case SIOCGIFADDRPREF:
329 	case SIOCSIFADDRPREF:
330 		if (ifp == NULL)
331 			return EINVAL;
332 		return ifaddrpref_ioctl(so, cmd, data, ifp, l);
333 	}
334 
335 	/*
336 	 * Find address for this interface, if it exists.
337 	 */
338 	if (ifp != NULL)
339 		IFP_TO_IA(ifp, ia);
340 
341 	switch (cmd) {
342 	case SIOCAIFADDR:
343 	case SIOCDIFADDR:
344 	case SIOCGIFALIAS:
345 		if (ifra->ifra_addr.sin_family == AF_INET)
346 			LIST_FOREACH(ia,
347 			    &IN_IFADDR_HASH(ifra->ifra_addr.sin_addr.s_addr),
348 			    ia_hash) {
349 				if (ia->ia_ifp == ifp &&
350 				    in_hosteq(ia->ia_addr.sin_addr,
351 				    ifra->ifra_addr.sin_addr))
352 					break;
353 			}
354 		if ((cmd == SIOCDIFADDR || cmd == SIOCGIFALIAS) && ia == NULL)
355 			return (EADDRNOTAVAIL);
356 
357 		if (cmd == SIOCDIFADDR &&
358 		    ifra->ifra_addr.sin_family == AF_UNSPEC) {
359 			ifra->ifra_addr.sin_family = AF_INET;
360 		}
361 		/* FALLTHROUGH */
362 	case SIOCSIFADDR:
363 	case SIOCSIFDSTADDR:
364 		if (ifra->ifra_addr.sin_family != AF_INET)
365 			return (EAFNOSUPPORT);
366 		/* FALLTHROUGH */
367 	case SIOCSIFNETMASK:
368 		if (ifp == NULL)
369 			panic("in_control");
370 
371 		if (cmd == SIOCGIFALIAS)
372 			break;
373 
374 		if (ia == NULL &&
375 		    (cmd == SIOCSIFNETMASK || cmd == SIOCSIFDSTADDR))
376 			return (EADDRNOTAVAIL);
377 
378 		if (l == NULL)
379 			return (EPERM);
380 		if (kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE,
381 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
382 		    NULL) != 0)
383 			return (EPERM);
384 
385 		if (ia == NULL) {
386 			ia = malloc(sizeof(*ia), M_IFADDR, M_WAITOK|M_ZERO);
387 			if (ia == NULL)
388 				return (ENOBUFS);
389 			TAILQ_INSERT_TAIL(&in_ifaddrhead, ia, ia_list);
390 			IFAREF(&ia->ia_ifa);
391 			ifa_insert(ifp, &ia->ia_ifa);
392 			ia->ia_ifa.ifa_addr = sintosa(&ia->ia_addr);
393 			ia->ia_ifa.ifa_dstaddr = sintosa(&ia->ia_dstaddr);
394 			ia->ia_ifa.ifa_netmask = sintosa(&ia->ia_sockmask);
395 #ifdef IPSELSRC
396 			ia->ia_ifa.ifa_getifa = in_getifa;
397 #else /* IPSELSRC */
398 			ia->ia_ifa.ifa_getifa = NULL;
399 #endif /* IPSELSRC */
400 			ia->ia_sockmask.sin_len = 8;
401 			if (ifp->if_flags & IFF_BROADCAST) {
402 				ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr);
403 				ia->ia_broadaddr.sin_family = AF_INET;
404 			}
405 			ia->ia_ifp = ifp;
406 			ia->ia_idsalt = cprng_fast32() % 65535;
407 			LIST_INIT(&ia->ia_multiaddrs);
408 			newifaddr = 1;
409 		}
410 		break;
411 
412 	case SIOCSIFBRDADDR:
413 		if (l == NULL)
414 			return (EPERM);
415 		if (kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE,
416 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
417 		    NULL) != 0)
418 			return (EPERM);
419 		/* FALLTHROUGH */
420 
421 	case SIOCGIFADDR:
422 	case SIOCGIFNETMASK:
423 	case SIOCGIFDSTADDR:
424 	case SIOCGIFBRDADDR:
425 		if (ia == NULL)
426 			return (EADDRNOTAVAIL);
427 		break;
428 	}
429 	error = 0;
430 	switch (cmd) {
431 
432 	case SIOCGIFADDR:
433 		ifreq_setaddr(cmd, ifr, sintocsa(&ia->ia_addr));
434 		break;
435 
436 	case SIOCGIFBRDADDR:
437 		if ((ifp->if_flags & IFF_BROADCAST) == 0)
438 			return (EINVAL);
439 		ifreq_setdstaddr(cmd, ifr, sintocsa(&ia->ia_broadaddr));
440 		break;
441 
442 	case SIOCGIFDSTADDR:
443 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
444 			return (EINVAL);
445 		ifreq_setdstaddr(cmd, ifr, sintocsa(&ia->ia_dstaddr));
446 		break;
447 
448 	case SIOCGIFNETMASK:
449 		ifreq_setaddr(cmd, ifr, sintocsa(&ia->ia_sockmask));
450 		break;
451 
452 	case SIOCSIFDSTADDR:
453 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
454 			return (EINVAL);
455 		oldaddr = ia->ia_dstaddr;
456 		ia->ia_dstaddr = *satocsin(ifreq_getdstaddr(cmd, ifr));
457 		if ((error = if_addr_init(ifp, &ia->ia_ifa, false)) != 0) {
458 			ia->ia_dstaddr = oldaddr;
459 			return error;
460 		}
461 		if (ia->ia_flags & IFA_ROUTE) {
462 			ia->ia_ifa.ifa_dstaddr = sintosa(&oldaddr);
463 			rtinit(&ia->ia_ifa, RTM_DELETE, RTF_HOST);
464 			ia->ia_ifa.ifa_dstaddr = sintosa(&ia->ia_dstaddr);
465 			rtinit(&ia->ia_ifa, RTM_ADD, RTF_HOST|RTF_UP);
466 		}
467 		break;
468 
469 	case SIOCSIFBRDADDR:
470 		if ((ifp->if_flags & IFF_BROADCAST) == 0)
471 			return EINVAL;
472 		ia->ia_broadaddr = *satocsin(ifreq_getbroadaddr(cmd, ifr));
473 		break;
474 
475 	case SIOCSIFADDR:
476 		error = in_ifinit(ifp, ia, satocsin(ifreq_getaddr(cmd, ifr)),
477 		    1);
478 #ifdef PFIL_HOOKS
479 		if (error == 0)
480 			(void)pfil_run_hooks(&if_pfil,
481 			    (struct mbuf **)SIOCSIFADDR, ifp, PFIL_IFADDR);
482 #endif
483 		break;
484 
485 	case SIOCSIFNETMASK:
486 		in_ifscrub(ifp, ia);
487 		ia->ia_sockmask = *satocsin(ifreq_getaddr(cmd, ifr));
488 		ia->ia_subnetmask = ia->ia_sockmask.sin_addr.s_addr;
489 		error = in_ifinit(ifp, ia, NULL, 0);
490 		break;
491 
492 	case SIOCAIFADDR:
493 		maskIsNew = 0;
494 		hostIsNew = 1;
495 		if (ia->ia_addr.sin_family != AF_INET)
496 			;
497 		else if (ifra->ifra_addr.sin_len == 0) {
498 			ifra->ifra_addr = ia->ia_addr;
499 			hostIsNew = 0;
500 		} else if (in_hosteq(ia->ia_addr.sin_addr,
501 		           ifra->ifra_addr.sin_addr))
502 			hostIsNew = 0;
503 		if (ifra->ifra_mask.sin_len) {
504 			/* Only scrub if we control the prefix route,
505 			 * otherwise userland gets a bogus message */
506 			if ((ia->ia_flags & IFA_ROUTE))
507 				in_ifscrub(ifp, ia);
508 			ia->ia_sockmask = ifra->ifra_mask;
509 			ia->ia_subnetmask = ia->ia_sockmask.sin_addr.s_addr;
510 			maskIsNew = 1;
511 		}
512 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
513 		    (ifra->ifra_dstaddr.sin_family == AF_INET)) {
514 			/* Only scrub if we control the prefix route,
515 			 * otherwise userland gets a bogus message */
516 			if ((ia->ia_flags & IFA_ROUTE))
517 				in_ifscrub(ifp, ia);
518 			ia->ia_dstaddr = ifra->ifra_dstaddr;
519 			maskIsNew  = 1; /* We lie; but the effect's the same */
520 		}
521 		if (ifra->ifra_addr.sin_family == AF_INET &&
522 		    (hostIsNew || maskIsNew)) {
523 			error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
524 		}
525 		if ((ifp->if_flags & IFF_BROADCAST) &&
526 		    (ifra->ifra_broadaddr.sin_family == AF_INET))
527 			ia->ia_broadaddr = ifra->ifra_broadaddr;
528 #ifdef PFIL_HOOKS
529 		if (error == 0)
530 			(void)pfil_run_hooks(&if_pfil,
531 			    (struct mbuf **)SIOCAIFADDR, ifp, PFIL_IFADDR);
532 #endif
533 		break;
534 
535 	case SIOCGIFALIAS:
536 		ifra->ifra_mask = ia->ia_sockmask;
537 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
538 		    (ia->ia_dstaddr.sin_family == AF_INET))
539 			ifra->ifra_dstaddr = ia->ia_dstaddr;
540 		else if ((ifp->if_flags & IFF_BROADCAST) &&
541 		    (ia->ia_broadaddr.sin_family == AF_INET))
542 			ifra->ifra_broadaddr = ia->ia_broadaddr;
543 		else
544 			memset(&ifra->ifra_broadaddr, 0,
545 			      sizeof(ifra->ifra_broadaddr));
546 		break;
547 
548 	case SIOCDIFADDR:
549 		in_purgeaddr(&ia->ia_ifa);
550 #ifdef PFIL_HOOKS
551 		(void)pfil_run_hooks(&if_pfil, (struct mbuf **)SIOCDIFADDR,
552 		    ifp, PFIL_IFADDR);
553 #endif
554 		break;
555 
556 #ifdef MROUTING
557 	case SIOCGETVIFCNT:
558 	case SIOCGETSGCNT:
559 		error = mrt_ioctl(so, cmd, data);
560 		break;
561 #endif /* MROUTING */
562 
563 	default:
564 		return ENOTTY;
565 	}
566 
567 	if (error != 0 && newifaddr) {
568 		KASSERT(ia != NULL);
569 		in_purgeaddr(&ia->ia_ifa);
570 	}
571 
572 	return error;
573 }
574 
575 void
576 in_purgeaddr(struct ifaddr *ifa)
577 {
578 	struct ifnet *ifp = ifa->ifa_ifp;
579 	struct in_ifaddr *ia = (void *) ifa;
580 
581 	in_ifscrub(ifp, ia);
582 	LIST_REMOVE(ia, ia_hash);
583 	ifa_remove(ifp, &ia->ia_ifa);
584 	TAILQ_REMOVE(&in_ifaddrhead, ia, ia_list);
585 	if (ia->ia_allhosts != NULL)
586 		in_delmulti(ia->ia_allhosts);
587 	IFAFREE(&ia->ia_ifa);
588 	in_setmaxmtu();
589 }
590 
591 void
592 in_purgeif(struct ifnet *ifp)		/* MUST be called at splsoftnet() */
593 {
594 	if_purgeaddrs(ifp, AF_INET, in_purgeaddr);
595 	igmp_purgeif(ifp);		/* manipulates pools */
596 #ifdef MROUTING
597 	ip_mrouter_detach(ifp);
598 #endif
599 }
600 
601 /*
602  * SIOC[GAD]LIFADDR.
603  *	SIOCGLIFADDR: get first address. (???)
604  *	SIOCGLIFADDR with IFLR_PREFIX:
605  *		get first address that matches the specified prefix.
606  *	SIOCALIFADDR: add the specified address.
607  *	SIOCALIFADDR with IFLR_PREFIX:
608  *		EINVAL since we can't deduce hostid part of the address.
609  *	SIOCDLIFADDR: delete the specified address.
610  *	SIOCDLIFADDR with IFLR_PREFIX:
611  *		delete the first address that matches the specified prefix.
612  * return values:
613  *	EINVAL on invalid parameters
614  *	EADDRNOTAVAIL on prefix match failed/specified address not found
615  *	other values may be returned from in_ioctl()
616  */
617 static int
618 in_lifaddr_ioctl(struct socket *so, u_long cmd, void *data,
619     struct ifnet *ifp, struct lwp *l)
620 {
621 	struct if_laddrreq *iflr = (struct if_laddrreq *)data;
622 	struct ifaddr *ifa;
623 	struct sockaddr *sa;
624 
625 	/* sanity checks */
626 	if (data == NULL || ifp == NULL) {
627 		panic("invalid argument to in_lifaddr_ioctl");
628 		/*NOTRECHED*/
629 	}
630 
631 	switch (cmd) {
632 	case SIOCGLIFADDR:
633 		/* address must be specified on GET with IFLR_PREFIX */
634 		if ((iflr->flags & IFLR_PREFIX) == 0)
635 			break;
636 		/*FALLTHROUGH*/
637 	case SIOCALIFADDR:
638 	case SIOCDLIFADDR:
639 		/* address must be specified on ADD and DELETE */
640 		sa = (struct sockaddr *)&iflr->addr;
641 		if (sa->sa_family != AF_INET)
642 			return EINVAL;
643 		if (sa->sa_len != sizeof(struct sockaddr_in))
644 			return EINVAL;
645 		/* XXX need improvement */
646 		sa = (struct sockaddr *)&iflr->dstaddr;
647 		if (sa->sa_family != AF_UNSPEC && sa->sa_family != AF_INET)
648 			return EINVAL;
649 		if (sa->sa_len != 0 && sa->sa_len != sizeof(struct sockaddr_in))
650 			return EINVAL;
651 		break;
652 	default: /*shouldn't happen*/
653 #if 0
654 		panic("invalid cmd to in_lifaddr_ioctl");
655 		/*NOTREACHED*/
656 #else
657 		return EOPNOTSUPP;
658 #endif
659 	}
660 	if (sizeof(struct in_addr) * NBBY < iflr->prefixlen)
661 		return EINVAL;
662 
663 	switch (cmd) {
664 	case SIOCALIFADDR:
665 	    {
666 		struct in_aliasreq ifra;
667 
668 		if (iflr->flags & IFLR_PREFIX)
669 			return EINVAL;
670 
671 		/* copy args to in_aliasreq, perform ioctl(SIOCAIFADDR). */
672 		memset(&ifra, 0, sizeof(ifra));
673 		memcpy(ifra.ifra_name, iflr->iflr_name,
674 			sizeof(ifra.ifra_name));
675 
676 		memcpy(&ifra.ifra_addr, &iflr->addr,
677 			((struct sockaddr *)&iflr->addr)->sa_len);
678 
679 		if (((struct sockaddr *)&iflr->dstaddr)->sa_family) {	/*XXX*/
680 			memcpy(&ifra.ifra_dstaddr, &iflr->dstaddr,
681 				((struct sockaddr *)&iflr->dstaddr)->sa_len);
682 		}
683 
684 		ifra.ifra_mask.sin_family = AF_INET;
685 		ifra.ifra_mask.sin_len = sizeof(struct sockaddr_in);
686 		in_len2mask(&ifra.ifra_mask.sin_addr, iflr->prefixlen);
687 
688 		return in_control(so, SIOCAIFADDR, (void *)&ifra, ifp, l);
689 	    }
690 	case SIOCGLIFADDR:
691 	case SIOCDLIFADDR:
692 	    {
693 		struct in_ifaddr *ia;
694 		struct in_addr mask, candidate, match;
695 		struct sockaddr_in *sin;
696 		int cmp;
697 
698 		memset(&mask, 0, sizeof(mask));
699 		memset(&match, 0, sizeof(match));	/* XXX gcc */
700 		if (iflr->flags & IFLR_PREFIX) {
701 			/* lookup a prefix rather than address. */
702 			in_len2mask(&mask, iflr->prefixlen);
703 
704 			sin = (struct sockaddr_in *)&iflr->addr;
705 			match.s_addr = sin->sin_addr.s_addr;
706 			match.s_addr &= mask.s_addr;
707 
708 			/* if you set extra bits, that's wrong */
709 			if (match.s_addr != sin->sin_addr.s_addr)
710 				return EINVAL;
711 
712 			cmp = 1;
713 		} else {
714 			if (cmd == SIOCGLIFADDR) {
715 				/* on getting an address, take the 1st match */
716 				cmp = 0;	/*XXX*/
717 			} else {
718 				/* on deleting an address, do exact match */
719 				in_len2mask(&mask, 32);
720 				sin = (struct sockaddr_in *)&iflr->addr;
721 				match.s_addr = sin->sin_addr.s_addr;
722 
723 				cmp = 1;
724 			}
725 		}
726 
727 		IFADDR_FOREACH(ifa, ifp) {
728 			if (ifa->ifa_addr->sa_family != AF_INET)
729 				continue;
730 			if (cmp == 0)
731 				break;
732 			candidate.s_addr = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr;
733 			candidate.s_addr &= mask.s_addr;
734 			if (candidate.s_addr == match.s_addr)
735 				break;
736 		}
737 		if (ifa == NULL)
738 			return EADDRNOTAVAIL;
739 		ia = (struct in_ifaddr *)ifa;
740 
741 		if (cmd == SIOCGLIFADDR) {
742 			/* fill in the if_laddrreq structure */
743 			memcpy(&iflr->addr, &ia->ia_addr, ia->ia_addr.sin_len);
744 
745 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
746 				memcpy(&iflr->dstaddr, &ia->ia_dstaddr,
747 					ia->ia_dstaddr.sin_len);
748 			} else
749 				memset(&iflr->dstaddr, 0, sizeof(iflr->dstaddr));
750 
751 			iflr->prefixlen =
752 				in_mask2len(&ia->ia_sockmask.sin_addr);
753 
754 			iflr->flags = 0;	/*XXX*/
755 
756 			return 0;
757 		} else {
758 			struct in_aliasreq ifra;
759 
760 			/* fill in_aliasreq and do ioctl(SIOCDIFADDR) */
761 			memset(&ifra, 0, sizeof(ifra));
762 			memcpy(ifra.ifra_name, iflr->iflr_name,
763 				sizeof(ifra.ifra_name));
764 
765 			memcpy(&ifra.ifra_addr, &ia->ia_addr,
766 				ia->ia_addr.sin_len);
767 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
768 				memcpy(&ifra.ifra_dstaddr, &ia->ia_dstaddr,
769 					ia->ia_dstaddr.sin_len);
770 			}
771 			memcpy(&ifra.ifra_dstaddr, &ia->ia_sockmask,
772 				ia->ia_sockmask.sin_len);
773 
774 			return in_control(so, SIOCDIFADDR, (void *)&ifra,
775 				ifp, l);
776 		}
777 	    }
778 	}
779 
780 	return EOPNOTSUPP;	/*just for safety*/
781 }
782 
783 /*
784  * Delete any existing route for an interface.
785  */
786 void
787 in_ifscrub(struct ifnet *ifp, struct in_ifaddr *ia)
788 {
789 
790 	in_scrubprefix(ia);
791 }
792 
793 /*
794  * Initialize an interface's internet address
795  * and routing table entry.
796  */
797 int
798 in_ifinit(struct ifnet *ifp, struct in_ifaddr *ia,
799     const struct sockaddr_in *sin, int scrub)
800 {
801 	u_int32_t i;
802 	struct sockaddr_in oldaddr;
803 	int s = splnet(), flags = RTF_UP, error;
804 
805 	if (sin == NULL)
806 		sin = &ia->ia_addr;
807 
808 	/*
809 	 * Set up new addresses.
810 	 */
811 	oldaddr = ia->ia_addr;
812 	if (ia->ia_addr.sin_family == AF_INET)
813 		LIST_REMOVE(ia, ia_hash);
814 	ia->ia_addr = *sin;
815 	LIST_INSERT_HEAD(&IN_IFADDR_HASH(ia->ia_addr.sin_addr.s_addr), ia, ia_hash);
816 
817 	/*
818 	 * Give the interface a chance to initialize
819 	 * if this is its first address,
820 	 * and to validate the address if necessary.
821 	 */
822 	if ((error = if_addr_init(ifp, &ia->ia_ifa, true)) != 0)
823 		goto bad;
824 	splx(s);
825 	if (scrub) {
826 		ia->ia_ifa.ifa_addr = sintosa(&oldaddr);
827 		in_ifscrub(ifp, ia);
828 		ia->ia_ifa.ifa_addr = sintosa(&ia->ia_addr);
829 	}
830 
831 	i = ia->ia_addr.sin_addr.s_addr;
832 	if (IN_CLASSA(i))
833 		ia->ia_netmask = IN_CLASSA_NET;
834 	else if (IN_CLASSB(i))
835 		ia->ia_netmask = IN_CLASSB_NET;
836 	else
837 		ia->ia_netmask = IN_CLASSC_NET;
838 	/*
839 	 * The subnet mask usually includes at least the standard network part,
840 	 * but may may be smaller in the case of supernetting.
841 	 * If it is set, we believe it.
842 	 */
843 	if (ia->ia_subnetmask == 0) {
844 		ia->ia_subnetmask = ia->ia_netmask;
845 		ia->ia_sockmask.sin_addr.s_addr = ia->ia_subnetmask;
846 	} else
847 		ia->ia_netmask &= ia->ia_subnetmask;
848 
849 	ia->ia_net = i & ia->ia_netmask;
850 	ia->ia_subnet = i & ia->ia_subnetmask;
851 	in_socktrim(&ia->ia_sockmask);
852 	/* re-calculate the "in_maxmtu" value */
853 	in_setmaxmtu();
854 	/*
855 	 * Add route for the network.
856 	 */
857 	ia->ia_ifa.ifa_metric = ifp->if_metric;
858 	if (ifp->if_flags & IFF_BROADCAST) {
859 		ia->ia_broadaddr.sin_addr.s_addr =
860 			ia->ia_subnet | ~ia->ia_subnetmask;
861 		ia->ia_netbroadcast.s_addr =
862 			ia->ia_net | ~ia->ia_netmask;
863 	} else if (ifp->if_flags & IFF_LOOPBACK) {
864 		ia->ia_dstaddr = ia->ia_addr;
865 		flags |= RTF_HOST;
866 	} else if (ifp->if_flags & IFF_POINTOPOINT) {
867 		if (ia->ia_dstaddr.sin_family != AF_INET)
868 			return (0);
869 		flags |= RTF_HOST;
870 	}
871 	error = in_addprefix(ia, flags);
872 	/*
873 	 * If the interface supports multicast, join the "all hosts"
874 	 * multicast group on that interface.
875 	 */
876 	if ((ifp->if_flags & IFF_MULTICAST) != 0 && ia->ia_allhosts == NULL) {
877 		struct in_addr addr;
878 
879 		addr.s_addr = INADDR_ALLHOSTS_GROUP;
880 		ia->ia_allhosts = in_addmulti(&addr, ifp);
881 	}
882 	return (error);
883 bad:
884 	splx(s);
885 	LIST_REMOVE(ia, ia_hash);
886 	ia->ia_addr = oldaddr;
887 	if (ia->ia_addr.sin_family == AF_INET)
888 		LIST_INSERT_HEAD(&IN_IFADDR_HASH(ia->ia_addr.sin_addr.s_addr),
889 		    ia, ia_hash);
890 	return (error);
891 }
892 
893 #define rtinitflags(x) \
894 	((((x)->ia_ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) != 0) \
895 	    ? RTF_HOST : 0)
896 
897 /*
898  * add a route to prefix ("connected route" in cisco terminology).
899  * does nothing if there's some interface address with the same prefix already.
900  */
901 static int
902 in_addprefix(struct in_ifaddr *target, int flags)
903 {
904 	struct in_ifaddr *ia;
905 	struct in_addr prefix, mask, p;
906 	int error;
907 
908 	if ((flags & RTF_HOST) != 0)
909 		prefix = target->ia_dstaddr.sin_addr;
910 	else {
911 		prefix = target->ia_addr.sin_addr;
912 		mask = target->ia_sockmask.sin_addr;
913 		prefix.s_addr &= mask.s_addr;
914 	}
915 
916 	TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list) {
917 		if (rtinitflags(ia))
918 			p = ia->ia_dstaddr.sin_addr;
919 		else {
920 			p = ia->ia_addr.sin_addr;
921 			p.s_addr &= ia->ia_sockmask.sin_addr.s_addr;
922 		}
923 
924 		if (prefix.s_addr != p.s_addr)
925 			continue;
926 
927 		/*
928 		 * if we got a matching prefix route inserted by other
929 		 * interface address, we don't need to bother
930 		 *
931 		 * XXX RADIX_MPATH implications here? -dyoung
932 		 *
933 		 * But we should still notify userland of the new address
934 		 */
935 		if (ia->ia_flags & IFA_ROUTE) {
936 			rt_newaddrmsg(RTM_NEWADDR, &target->ia_ifa, 0, NULL);
937 			return 0;
938 		}
939 	}
940 
941 	/*
942 	 * noone seem to have prefix route.  insert it.
943 	 */
944 	error = rtinit(&target->ia_ifa, RTM_ADD, flags);
945 	if (error == 0)
946 		target->ia_flags |= IFA_ROUTE;
947 	else if (error == EEXIST) {
948 		/*
949 		 * the fact the route already exists is not an error.
950 		 */
951 		error = 0;
952 	}
953 	return error;
954 }
955 
956 /*
957  * remove a route to prefix ("connected route" in cisco terminology).
958  * re-installs the route by using another interface address, if there's one
959  * with the same prefix (otherwise we lose the route mistakenly).
960  */
961 static int
962 in_scrubprefix(struct in_ifaddr *target)
963 {
964 	struct in_ifaddr *ia;
965 	struct in_addr prefix, mask, p;
966 	int error;
967 
968 	/* If we don't have IFA_ROUTE we should still inform userland */
969 	if ((target->ia_flags & IFA_ROUTE) == 0) {
970 		rt_newaddrmsg(RTM_DELADDR, &target->ia_ifa, 0, NULL);
971 		return 0;
972 	}
973 
974 	if (rtinitflags(target))
975 		prefix = target->ia_dstaddr.sin_addr;
976 	else {
977 		prefix = target->ia_addr.sin_addr;
978 		mask = target->ia_sockmask.sin_addr;
979 		prefix.s_addr &= mask.s_addr;
980 	}
981 
982 	TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list) {
983 		if (rtinitflags(ia))
984 			p = ia->ia_dstaddr.sin_addr;
985 		else {
986 			p = ia->ia_addr.sin_addr;
987 			p.s_addr &= ia->ia_sockmask.sin_addr.s_addr;
988 		}
989 
990 		if (prefix.s_addr != p.s_addr)
991 			continue;
992 
993 		/*
994 		 * if we got a matching prefix route, move IFA_ROUTE to him
995 		 */
996 		if ((ia->ia_flags & IFA_ROUTE) == 0) {
997 			rtinit(&target->ia_ifa, RTM_DELETE,
998 			    rtinitflags(target));
999 			target->ia_flags &= ~IFA_ROUTE;
1000 
1001 			error = rtinit(&ia->ia_ifa, RTM_ADD,
1002 			    rtinitflags(ia) | RTF_UP);
1003 			if (error == 0)
1004 				ia->ia_flags |= IFA_ROUTE;
1005 			return error;
1006 		}
1007 	}
1008 
1009 	/*
1010 	 * noone seem to have prefix route.  remove it.
1011 	 */
1012 	rtinit(&target->ia_ifa, RTM_DELETE, rtinitflags(target));
1013 	target->ia_flags &= ~IFA_ROUTE;
1014 	return 0;
1015 }
1016 
1017 #undef rtinitflags
1018 
1019 /*
1020  * Return 1 if the address might be a local broadcast address.
1021  */
1022 int
1023 in_broadcast(struct in_addr in, struct ifnet *ifp)
1024 {
1025 	struct ifaddr *ifa;
1026 
1027 	if (in.s_addr == INADDR_BROADCAST ||
1028 	    in_nullhost(in))
1029 		return 1;
1030 	if ((ifp->if_flags & IFF_BROADCAST) == 0)
1031 		return 0;
1032 	/*
1033 	 * Look through the list of addresses for a match
1034 	 * with a broadcast address.
1035 	 */
1036 #define ia (ifatoia(ifa))
1037 	IFADDR_FOREACH(ifa, ifp)
1038 		if (ifa->ifa_addr->sa_family == AF_INET &&
1039 		    !in_hosteq(in, ia->ia_addr.sin_addr) &&
1040 		    (in_hosteq(in, ia->ia_broadaddr.sin_addr) ||
1041 		     in_hosteq(in, ia->ia_netbroadcast) ||
1042 		     (hostzeroisbroadcast &&
1043 		      /*
1044 		       * Check for old-style (host 0) broadcast.
1045 		       */
1046 		      (in.s_addr == ia->ia_subnet ||
1047 		       in.s_addr == ia->ia_net))))
1048 			return 1;
1049 	return (0);
1050 #undef ia
1051 }
1052 
1053 /*
1054  * Add an address to the list of IP multicast addresses for a given interface.
1055  */
1056 struct in_multi *
1057 in_addmulti(struct in_addr *ap, struct ifnet *ifp)
1058 {
1059 	struct sockaddr_in sin;
1060 	struct in_multi *inm;
1061 	int s = splsoftnet();
1062 
1063 	/*
1064 	 * See if address already in list.
1065 	 */
1066 	IN_LOOKUP_MULTI(*ap, ifp, inm);
1067 	if (inm != NULL) {
1068 		/*
1069 		 * Found it; just increment the reference count.
1070 		 */
1071 		++inm->inm_refcount;
1072 	} else {
1073 		/*
1074 		 * New address; allocate a new multicast record
1075 		 * and link it into the interface's multicast list.
1076 		 */
1077 		inm = pool_get(&inmulti_pool, PR_NOWAIT);
1078 		if (inm == NULL) {
1079 			splx(s);
1080 			return (NULL);
1081 		}
1082 		inm->inm_addr = *ap;
1083 		inm->inm_ifp = ifp;
1084 		inm->inm_refcount = 1;
1085 		LIST_INSERT_HEAD(
1086 		    &IN_MULTI_HASH(inm->inm_addr.s_addr, ifp),
1087 		    inm, inm_list);
1088 		/*
1089 		 * Ask the network driver to update its multicast reception
1090 		 * filter appropriately for the new address.
1091 		 */
1092 		sockaddr_in_init(&sin, ap, 0);
1093 		if (if_mcast_op(ifp, SIOCADDMULTI, sintosa(&sin)) != 0) {
1094 			LIST_REMOVE(inm, inm_list);
1095 			pool_put(&inmulti_pool, inm);
1096 			splx(s);
1097 			return (NULL);
1098 		}
1099 		/*
1100 		 * Let IGMP know that we have joined a new IP multicast group.
1101 		 */
1102 		if (igmp_joingroup(inm) != 0) {
1103 			LIST_REMOVE(inm, inm_list);
1104 			pool_put(&inmulti_pool, inm);
1105 			splx(s);
1106 			return (NULL);
1107 		}
1108 		in_multientries++;
1109 	}
1110 	splx(s);
1111 	return (inm);
1112 }
1113 
1114 /*
1115  * Delete a multicast address record.
1116  */
1117 void
1118 in_delmulti(struct in_multi *inm)
1119 {
1120 	struct sockaddr_in sin;
1121 	int s = splsoftnet();
1122 
1123 	if (--inm->inm_refcount == 0) {
1124 		/*
1125 		 * No remaining claims to this record; let IGMP know that
1126 		 * we are leaving the multicast group.
1127 		 */
1128 		igmp_leavegroup(inm);
1129 		/*
1130 		 * Unlink from list.
1131 		 */
1132 		LIST_REMOVE(inm, inm_list);
1133 		in_multientries--;
1134 		/*
1135 		 * Notify the network driver to update its multicast reception
1136 		 * filter.
1137 		 */
1138 		sockaddr_in_init(&sin, &inm->inm_addr, 0);
1139 		if_mcast_op(inm->inm_ifp, SIOCDELMULTI, sintosa(&sin));
1140 		pool_put(&inmulti_pool, inm);
1141 	}
1142 	splx(s);
1143 }
1144