xref: /dragonfly/sys/netinet/in.c (revision c03f08f3)
1 /*
2  * Copyright (c) 1982, 1986, 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	@(#)in.c	8.4 (Berkeley) 1/9/95
34  * $FreeBSD: src/sys/netinet/in.c,v 1.44.2.14 2002/11/08 00:45:50 suz Exp $
35  * $DragonFly: src/sys/netinet/in.c,v 1.20 2006/09/30 22:38:21 swildner Exp $
36  */
37 
38 #include "opt_bootp.h"
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/sockio.h>
42 #include <sys/malloc.h>
43 #include <sys/proc.h>
44 #include <sys/socket.h>
45 #include <sys/kernel.h>
46 #include <sys/sysctl.h>
47 #include <sys/thread2.h>
48 
49 #include <net/if.h>
50 #include <net/if_types.h>
51 #include <net/route.h>
52 
53 #include <netinet/in.h>
54 #include <netinet/in_var.h>
55 #include <netinet/in_pcb.h>
56 
57 #include <netinet/igmp_var.h>
58 
59 MALLOC_DEFINE(M_IPMADDR, "in_multi", "internet multicast address");
60 
61 static int in_mask2len (struct in_addr *);
62 static void in_len2mask (struct in_addr *, int);
63 static int in_lifaddr_ioctl (struct socket *, u_long, caddr_t,
64 	struct ifnet *, struct thread *);
65 
66 static void	in_socktrim (struct sockaddr_in *);
67 static int	in_ifinit (struct ifnet *,
68 	    struct in_ifaddr *, struct sockaddr_in *, int);
69 
70 static int subnetsarelocal = 0;
71 SYSCTL_INT(_net_inet_ip, OID_AUTO, subnets_are_local, CTLFLAG_RW,
72 	&subnetsarelocal, 0, "");
73 
74 struct in_multihead in_multihead; /* XXX BSS initialization */
75 
76 extern struct inpcbinfo ripcbinfo;
77 extern struct inpcbinfo udbinfo;
78 
79 /*
80  * Return 1 if an internet address is for a ``local'' host
81  * (one to which we have a connection).  If subnetsarelocal
82  * is true, this includes other subnets of the local net.
83  * Otherwise, it includes only the directly-connected (sub)nets.
84  */
85 int
86 in_localaddr(struct in_addr in)
87 {
88 	u_long i = ntohl(in.s_addr);
89 	struct in_ifaddr *ia;
90 
91 	if (subnetsarelocal) {
92 		TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link)
93 			if ((i & ia->ia_netmask) == ia->ia_net)
94 				return (1);
95 	} else {
96 		TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link)
97 			if ((i & ia->ia_subnetmask) == ia->ia_subnet)
98 				return (1);
99 	}
100 	return (0);
101 }
102 
103 /*
104  * Determine whether an IP address is in a reserved set of addresses
105  * that may not be forwarded, or whether datagrams to that destination
106  * may be forwarded.
107  */
108 int
109 in_canforward(struct in_addr in)
110 {
111 	u_long i = ntohl(in.s_addr);
112 	u_long net;
113 
114 	if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i))
115 		return (0);
116 	if (IN_CLASSA(i)) {
117 		net = i & IN_CLASSA_NET;
118 		if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
119 			return (0);
120 	}
121 	return (1);
122 }
123 
124 /*
125  * Trim a mask in a sockaddr
126  */
127 static void
128 in_socktrim(struct sockaddr_in *ap)
129 {
130     char *cplim = (char *) &ap->sin_addr;
131     char *cp = (char *) (&ap->sin_addr + 1);
132 
133     ap->sin_len = 0;
134     while (--cp >= cplim)
135 	if (*cp) {
136 	    (ap)->sin_len = cp - (char *) (ap) + 1;
137 	    break;
138 	}
139 }
140 
141 static int
142 in_mask2len(struct in_addr *mask)
143 {
144 	int x, y;
145 	u_char *p;
146 
147 	p = (u_char *)mask;
148 	for (x = 0; x < sizeof *mask; x++) {
149 		if (p[x] != 0xff)
150 			break;
151 	}
152 	y = 0;
153 	if (x < sizeof *mask) {
154 		for (y = 0; y < 8; y++) {
155 			if ((p[x] & (0x80 >> y)) == 0)
156 				break;
157 		}
158 	}
159 	return x * 8 + y;
160 }
161 
162 static void
163 in_len2mask(struct in_addr *mask, int len)
164 {
165 	int i;
166 	u_char *p;
167 
168 	p = (u_char *)mask;
169 	bzero(mask, sizeof *mask);
170 	for (i = 0; i < len / 8; i++)
171 		p[i] = 0xff;
172 	if (len % 8)
173 		p[i] = (0xff00 >> (len % 8)) & 0xff;
174 }
175 
176 static int in_interfaces;	/* number of external internet interfaces */
177 
178 /*
179  * Generic internet control operations (ioctl's).
180  * Ifp is 0 if not an interface-specific ioctl.
181  *
182  * NOTE! td might be NULL.
183  */
184 /* ARGSUSED */
185 int
186 in_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
187 	   struct thread *td)
188 {
189 	struct ifreq *ifr = (struct ifreq *)data;
190 	struct in_ifaddr *ia = 0, *iap;
191 	struct ifaddr *ifa;
192 	struct in_addr dst;
193 	struct in_ifaddr *oia;
194 	struct in_aliasreq *ifra = (struct in_aliasreq *)data;
195 	struct sockaddr_in oldaddr;
196 	int hostIsNew, iaIsNew, maskIsNew;
197 	int error = 0;
198 
199 	iaIsNew = 0;
200 
201 	switch (cmd) {
202 	case SIOCALIFADDR:
203 	case SIOCDLIFADDR:
204 		if (td && (error = suser(td)) != 0)
205 			return error;
206 		/*fall through*/
207 	case SIOCGLIFADDR:
208 		if (!ifp)
209 			return EINVAL;
210 		return in_lifaddr_ioctl(so, cmd, data, ifp, td);
211 	}
212 
213 	/*
214 	 * Find address for this interface, if it exists.
215 	 *
216 	 * If an alias address was specified, find that one instead of
217 	 * the first one on the interface, if possible
218 	 */
219 	if (ifp) {
220 		dst = ((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr;
221 		LIST_FOREACH(iap, INADDR_HASH(dst.s_addr), ia_hash)
222 			if (iap->ia_ifp == ifp &&
223 			    iap->ia_addr.sin_addr.s_addr == dst.s_addr) {
224 				ia = iap;
225 				break;
226 			}
227 		if (ia == NULL)
228 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
229 				iap = ifatoia(ifa);
230 				if (iap->ia_addr.sin_family == AF_INET) {
231 					ia = iap;
232 					break;
233 				}
234 			}
235 	}
236 
237 	switch (cmd) {
238 
239 	case SIOCAIFADDR:
240 	case SIOCDIFADDR:
241 		if (ifp == 0)
242 			return (EADDRNOTAVAIL);
243 		if (ifra->ifra_addr.sin_family == AF_INET) {
244 			for (oia = ia; ia; ia = TAILQ_NEXT(ia, ia_link)) {
245 				if (ia->ia_ifp == ifp  &&
246 				    ia->ia_addr.sin_addr.s_addr ==
247 				    ifra->ifra_addr.sin_addr.s_addr)
248 					break;
249 			}
250 			if ((ifp->if_flags & IFF_POINTOPOINT)
251 			    && (cmd == SIOCAIFADDR)
252 			    && (ifra->ifra_dstaddr.sin_addr.s_addr
253 				== INADDR_ANY)) {
254 				return EDESTADDRREQ;
255 			}
256 		}
257 		if (cmd == SIOCDIFADDR && ia == 0)
258 			return (EADDRNOTAVAIL);
259 		/* FALLTHROUGH */
260 	case SIOCSIFADDR:
261 	case SIOCSIFNETMASK:
262 	case SIOCSIFDSTADDR:
263 		if (td && (error = suser(td)) != 0)
264 			return error;
265 
266 		if (ifp == 0)
267 			return (EADDRNOTAVAIL);
268 		if (ia == (struct in_ifaddr *)0) {
269 			ia = (struct in_ifaddr *)
270 				kmalloc(sizeof *ia, M_IFADDR, M_WAITOK);
271 			if (ia == (struct in_ifaddr *)NULL)
272 				return (ENOBUFS);
273 			bzero(ia, sizeof *ia);
274 			/*
275 			 * Protect from ipintr() traversing address list
276 			 * while we're modifying it.
277 			 */
278 			crit_enter();
279 
280 			TAILQ_INSERT_TAIL(&in_ifaddrhead, ia, ia_link);
281 			ifa = &ia->ia_ifa;
282 			TAILQ_INSERT_TAIL(&ifp->if_addrhead, ifa, ifa_link);
283 
284 			ifa->ifa_addr = (struct sockaddr *)&ia->ia_addr;
285 			ifa->ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr;
286 			ifa->ifa_netmask = (struct sockaddr *)&ia->ia_sockmask;
287 			ia->ia_sockmask.sin_len = 8;
288 			ia->ia_sockmask.sin_family = AF_INET;
289 			if (ifp->if_flags & IFF_BROADCAST) {
290 				ia->ia_broadaddr.sin_len = sizeof ia->ia_addr;
291 				ia->ia_broadaddr.sin_family = AF_INET;
292 			}
293 			ia->ia_ifp = ifp;
294 			if (!(ifp->if_flags & IFF_LOOPBACK))
295 				in_interfaces++;
296 			iaIsNew = 1;
297 			crit_exit();
298 		}
299 		break;
300 
301 	case SIOCSIFBRDADDR:
302 		if (td && (error = suser(td)) != 0)
303 			return error;
304 		/* FALLTHROUGH */
305 
306 	case SIOCGIFADDR:
307 	case SIOCGIFNETMASK:
308 	case SIOCGIFDSTADDR:
309 	case SIOCGIFBRDADDR:
310 		if (ia == (struct in_ifaddr *)0)
311 			return (EADDRNOTAVAIL);
312 		break;
313 	}
314 	switch (cmd) {
315 
316 	case SIOCGIFADDR:
317 		*((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr;
318 		return (0);
319 
320 	case SIOCGIFBRDADDR:
321 		if ((ifp->if_flags & IFF_BROADCAST) == 0)
322 			return (EINVAL);
323 		*((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr;
324 		return (0);
325 
326 	case SIOCGIFDSTADDR:
327 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
328 			return (EINVAL);
329 		*((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr;
330 		return (0);
331 
332 	case SIOCGIFNETMASK:
333 		*((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask;
334 		return (0);
335 
336 	case SIOCSIFDSTADDR:
337 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
338 			return (EINVAL);
339 		oldaddr = ia->ia_dstaddr;
340 		ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr;
341 		lwkt_serialize_enter(ifp->if_serializer);
342 		if (ifp->if_ioctl &&
343 		    (error = ifp->if_ioctl(ifp, SIOCSIFDSTADDR, (caddr_t)ia,
344 					      td->td_proc->p_ucred))) {
345 			ia->ia_dstaddr = oldaddr;
346 			lwkt_serialize_exit(ifp->if_serializer);
347 			return (error);
348 		}
349 		if (ia->ia_flags & IFA_ROUTE) {
350 			ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr;
351 			rtinit(&ia->ia_ifa, RTM_DELETE, RTF_HOST);
352 			ia->ia_ifa.ifa_dstaddr =
353 					(struct sockaddr *)&ia->ia_dstaddr;
354 			rtinit(&ia->ia_ifa, RTM_ADD, RTF_HOST | RTF_UP);
355 		}
356 		lwkt_serialize_exit(ifp->if_serializer);
357 		return (0);
358 
359 	case SIOCSIFBRDADDR:
360 		if ((ifp->if_flags & IFF_BROADCAST) == 0)
361 			return (EINVAL);
362 		ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr;
363 		return (0);
364 
365 	case SIOCSIFADDR:
366 		error = in_ifinit(ifp, ia,
367 		    (struct sockaddr_in *) &ifr->ifr_addr, 1);
368 		if (error != 0 && iaIsNew)
369 			break;
370 		if (error == 0)
371 			EVENTHANDLER_INVOKE(ifaddr_event, ifp);
372 		return (0);
373 
374 	case SIOCSIFNETMASK:
375 		ia->ia_sockmask.sin_addr = ifra->ifra_addr.sin_addr;
376 		ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr);
377 		return (0);
378 
379 	case SIOCAIFADDR:
380 		maskIsNew = 0;
381 		hostIsNew = 1;
382 		error = 0;
383 		if (ia->ia_addr.sin_family == AF_INET) {
384 			if (ifra->ifra_addr.sin_len == 0) {
385 				ifra->ifra_addr = ia->ia_addr;
386 				hostIsNew = 0;
387 			} else if (ifra->ifra_addr.sin_addr.s_addr ==
388 					       ia->ia_addr.sin_addr.s_addr)
389 				hostIsNew = 0;
390 		}
391 		if (ifra->ifra_mask.sin_len) {
392 			in_ifscrub(ifp, ia);
393 			ia->ia_sockmask = ifra->ifra_mask;
394 			ia->ia_sockmask.sin_family = AF_INET;
395 			ia->ia_subnetmask =
396 			     ntohl(ia->ia_sockmask.sin_addr.s_addr);
397 			maskIsNew = 1;
398 		}
399 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
400 		    (ifra->ifra_dstaddr.sin_family == AF_INET)) {
401 			in_ifscrub(ifp, ia);
402 			ia->ia_dstaddr = ifra->ifra_dstaddr;
403 			maskIsNew  = 1; /* We lie; but the effect's the same */
404 		}
405 		if (ifra->ifra_addr.sin_family == AF_INET &&
406 		    (hostIsNew || maskIsNew))
407 			error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
408 
409 		if (error != 0 && iaIsNew)
410 			break;
411 
412 		if ((ifp->if_flags & IFF_BROADCAST) &&
413 		    (ifra->ifra_broadaddr.sin_family == AF_INET))
414 			ia->ia_broadaddr = ifra->ifra_broadaddr;
415 		if (error == 0)
416 			EVENTHANDLER_INVOKE(ifaddr_event, ifp);
417 		return (error);
418 
419 	case SIOCDIFADDR:
420 		/*
421 		 * in_ifscrub kills the interface route.
422 		 */
423 		in_ifscrub(ifp, ia);
424 		/*
425 		 * in_ifadown gets rid of all the rest of
426 		 * the routes.  This is not quite the right
427 		 * thing to do, but at least if we are running
428 		 * a routing process they will come back.
429 		 */
430 		in_ifadown(&ia->ia_ifa, 1);
431 		EVENTHANDLER_INVOKE(ifaddr_event, ifp);
432 		error = 0;
433 		break;
434 
435 	default:
436 		if (ifp == NULL || ifp->if_ioctl == NULL)
437 			return (EOPNOTSUPP);
438 		lwkt_serialize_enter(ifp->if_serializer);
439 		error = ifp->if_ioctl(ifp, cmd, data, td->td_proc->p_ucred);
440 		lwkt_serialize_exit(ifp->if_serializer);
441 		return (error);
442 	}
443 
444 	/*
445 	 * Protect from ipintr() traversing address list while we're modifying
446 	 * it.
447 	 */
448 	lwkt_serialize_enter(ifp->if_serializer);
449 	TAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifa_link);
450 	TAILQ_REMOVE(&in_ifaddrhead, ia, ia_link);
451 	LIST_REMOVE(ia, ia_hash);
452 	IFAFREE(&ia->ia_ifa);
453 	lwkt_serialize_exit(ifp->if_serializer);
454 
455 	return (error);
456 }
457 
458 /*
459  * SIOC[GAD]LIFADDR.
460  *	SIOCGLIFADDR: get first address. (?!?)
461  *	SIOCGLIFADDR with IFLR_PREFIX:
462  *		get first address that matches the specified prefix.
463  *	SIOCALIFADDR: add the specified address.
464  *	SIOCALIFADDR with IFLR_PREFIX:
465  *		EINVAL since we can't deduce hostid part of the address.
466  *	SIOCDLIFADDR: delete the specified address.
467  *	SIOCDLIFADDR with IFLR_PREFIX:
468  *		delete the first address that matches the specified prefix.
469  * return values:
470  *	EINVAL on invalid parameters
471  *	EADDRNOTAVAIL on prefix match failed/specified address not found
472  *	other values may be returned from in_ioctl()
473  *
474  * NOTE! td might be NULL.
475  */
476 static int
477 in_lifaddr_ioctl(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
478 		 struct thread *td)
479 {
480 	struct if_laddrreq *iflr = (struct if_laddrreq *)data;
481 	struct ifaddr *ifa;
482 
483 	/* sanity checks */
484 	if (!data || !ifp) {
485 		panic("invalid argument to in_lifaddr_ioctl");
486 		/*NOTRECHED*/
487 	}
488 
489 	switch (cmd) {
490 	case SIOCGLIFADDR:
491 		/* address must be specified on GET with IFLR_PREFIX */
492 		if ((iflr->flags & IFLR_PREFIX) == 0)
493 			break;
494 		/*FALLTHROUGH*/
495 	case SIOCALIFADDR:
496 	case SIOCDLIFADDR:
497 		/* address must be specified on ADD and DELETE */
498 		if (iflr->addr.ss_family != AF_INET)
499 			return EINVAL;
500 		if (iflr->addr.ss_len != sizeof(struct sockaddr_in))
501 			return EINVAL;
502 		/* XXX need improvement */
503 		if (iflr->dstaddr.ss_family
504 		 && iflr->dstaddr.ss_family != AF_INET)
505 			return EINVAL;
506 		if (iflr->dstaddr.ss_family
507 		 && iflr->dstaddr.ss_len != sizeof(struct sockaddr_in))
508 			return EINVAL;
509 		break;
510 	default: /*shouldn't happen*/
511 		return EOPNOTSUPP;
512 	}
513 	if (sizeof(struct in_addr) * 8 < iflr->prefixlen)
514 		return EINVAL;
515 
516 	switch (cmd) {
517 	case SIOCALIFADDR:
518 	    {
519 		struct in_aliasreq ifra;
520 
521 		if (iflr->flags & IFLR_PREFIX)
522 			return EINVAL;
523 
524 		/* copy args to in_aliasreq, perform ioctl(SIOCAIFADDR_IN6). */
525 		bzero(&ifra, sizeof ifra);
526 		bcopy(iflr->iflr_name, ifra.ifra_name, sizeof ifra.ifra_name);
527 
528 		bcopy(&iflr->addr, &ifra.ifra_addr, iflr->addr.ss_len);
529 
530 		if (iflr->dstaddr.ss_family) {	/*XXX*/
531 			bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
532 				iflr->dstaddr.ss_len);
533 		}
534 
535 		ifra.ifra_mask.sin_family = AF_INET;
536 		ifra.ifra_mask.sin_len = sizeof(struct sockaddr_in);
537 		in_len2mask(&ifra.ifra_mask.sin_addr, iflr->prefixlen);
538 
539 		return in_control(so, SIOCAIFADDR, (caddr_t)&ifra, ifp, td);
540 	    }
541 	case SIOCGLIFADDR:
542 	case SIOCDLIFADDR:
543 	    {
544 		struct in_ifaddr *ia;
545 		struct in_addr mask, candidate, match;
546 		struct sockaddr_in *sin;
547 		int cmp;
548 
549 		bzero(&mask, sizeof mask);
550 		if (iflr->flags & IFLR_PREFIX) {
551 			/* lookup a prefix rather than address. */
552 			in_len2mask(&mask, iflr->prefixlen);
553 
554 			sin = (struct sockaddr_in *)&iflr->addr;
555 			match.s_addr = sin->sin_addr.s_addr;
556 			match.s_addr &= mask.s_addr;
557 
558 			/* if you set extra bits, that's wrong */
559 			if (match.s_addr != sin->sin_addr.s_addr)
560 				return EINVAL;
561 
562 			cmp = 1;
563 		} else {
564 			if (cmd == SIOCGLIFADDR) {
565 				/* on getting an address, take the 1st match */
566 				cmp = 0;	/*XXX*/
567 			} else {
568 				/* on deleting an address, do exact match */
569 				in_len2mask(&mask, 32);
570 				sin = (struct sockaddr_in *)&iflr->addr;
571 				match.s_addr = sin->sin_addr.s_addr;
572 
573 				cmp = 1;
574 			}
575 		}
576 
577 		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)	{
578 			if (ifa->ifa_addr->sa_family != AF_INET6)
579 				continue;
580 			if (!cmp)
581 				break;
582 			candidate.s_addr = ((struct sockaddr_in *)&ifa->ifa_addr)->sin_addr.s_addr;
583 			candidate.s_addr &= mask.s_addr;
584 			if (candidate.s_addr == match.s_addr)
585 				break;
586 		}
587 		if (!ifa)
588 			return EADDRNOTAVAIL;
589 		ia = (struct in_ifaddr *)ifa;
590 
591 		if (cmd == SIOCGLIFADDR) {
592 			/* fill in the if_laddrreq structure */
593 			bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin_len);
594 
595 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
596 				bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
597 					ia->ia_dstaddr.sin_len);
598 			} else
599 				bzero(&iflr->dstaddr, sizeof iflr->dstaddr);
600 
601 			iflr->prefixlen =
602 				in_mask2len(&ia->ia_sockmask.sin_addr);
603 
604 			iflr->flags = 0;	/*XXX*/
605 
606 			return 0;
607 		} else {
608 			struct in_aliasreq ifra;
609 
610 			/* fill in_aliasreq and do ioctl(SIOCDIFADDR_IN6) */
611 			bzero(&ifra, sizeof ifra);
612 			bcopy(iflr->iflr_name, ifra.ifra_name,
613 				sizeof ifra.ifra_name);
614 
615 			bcopy(&ia->ia_addr, &ifra.ifra_addr,
616 				ia->ia_addr.sin_len);
617 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
618 				bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
619 					ia->ia_dstaddr.sin_len);
620 			}
621 			bcopy(&ia->ia_sockmask, &ifra.ifra_dstaddr,
622 				ia->ia_sockmask.sin_len);
623 
624 			return in_control(so, SIOCDIFADDR, (caddr_t)&ifra,
625 					  ifp, td);
626 		}
627 	    }
628 	}
629 
630 	return EOPNOTSUPP;	/*just for safety*/
631 }
632 
633 /*
634  * Delete any existing route for an interface.
635  */
636 void
637 in_ifscrub(struct ifnet *ifp, struct in_ifaddr *ia)
638 {
639 
640 	if ((ia->ia_flags & IFA_ROUTE) == 0)
641 		return;
642 	if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT))
643 		rtinit(&ia->ia_ifa, RTM_DELETE, RTF_HOST);
644 	else
645 		rtinit(&ia->ia_ifa, RTM_DELETE, 0);
646 	ia->ia_flags &= ~IFA_ROUTE;
647 }
648 
649 /*
650  * Initialize an interface's internet address
651  * and routing table entry.
652  */
653 static int
654 in_ifinit(struct ifnet *ifp, struct in_ifaddr *ia, struct sockaddr_in *sin, int scrub)
655 {
656 	u_long i = ntohl(sin->sin_addr.s_addr);
657 	struct sockaddr_in oldaddr;
658 	int flags = RTF_UP, error = 0;
659 
660 	lwkt_serialize_enter(ifp->if_serializer);
661 
662 	oldaddr = ia->ia_addr;
663 	if (oldaddr.sin_family == AF_INET)
664 		LIST_REMOVE(ia, ia_hash);
665 	ia->ia_addr = *sin;
666 	if (ia->ia_addr.sin_family == AF_INET)
667 		LIST_INSERT_HEAD(INADDR_HASH(ia->ia_addr.sin_addr.s_addr),
668 		    ia, ia_hash);
669 	/*
670 	 * Give the interface a chance to initialize
671 	 * if this is its first address,
672 	 * and to validate the address if necessary.
673 	 */
674 	if (ifp->if_ioctl &&
675 	    (error = ifp->if_ioctl(ifp, SIOCSIFADDR, (caddr_t)ia, NULL))) {
676 		lwkt_serialize_exit(ifp->if_serializer);
677 		/* LIST_REMOVE(ia, ia_hash) is done in in_control */
678 		ia->ia_addr = oldaddr;
679 		if (ia->ia_addr.sin_family == AF_INET)
680 			LIST_INSERT_HEAD(INADDR_HASH(ia->ia_addr.sin_addr.s_addr),
681 			    ia, ia_hash);
682 		return (error);
683 	}
684 	lwkt_serialize_exit(ifp->if_serializer);
685 	if (scrub) {
686 		ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr;
687 		in_ifscrub(ifp, ia);
688 		ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
689 	}
690 	if (IN_CLASSA(i))
691 		ia->ia_netmask = IN_CLASSA_NET;
692 	else if (IN_CLASSB(i))
693 		ia->ia_netmask = IN_CLASSB_NET;
694 	else
695 		ia->ia_netmask = IN_CLASSC_NET;
696 	/*
697 	 * The subnet mask usually includes at least the standard network part,
698 	 * but may may be smaller in the case of supernetting.
699 	 * If it is set, we believe it.
700 	 */
701 	if (ia->ia_subnetmask == 0) {
702 		ia->ia_subnetmask = ia->ia_netmask;
703 		ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
704 	} else
705 		ia->ia_netmask &= ia->ia_subnetmask;
706 	ia->ia_net = i & ia->ia_netmask;
707 	ia->ia_subnet = i & ia->ia_subnetmask;
708 	in_socktrim(&ia->ia_sockmask);
709 	/*
710 	 * Add route for the network.
711 	 */
712 	ia->ia_ifa.ifa_metric = ifp->if_metric;
713 	if (ifp->if_flags & IFF_BROADCAST) {
714 		ia->ia_broadaddr.sin_addr.s_addr =
715 			htonl(ia->ia_subnet | ~ia->ia_subnetmask);
716 		ia->ia_netbroadcast.s_addr =
717 			htonl(ia->ia_net | ~ ia->ia_netmask);
718 	} else if (ifp->if_flags & IFF_LOOPBACK) {
719 		ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr;
720 		flags |= RTF_HOST;
721 	} else if (ifp->if_flags & IFF_POINTOPOINT) {
722 		if (ia->ia_dstaddr.sin_family != AF_INET)
723 			return (0);
724 		flags |= RTF_HOST;
725 	}
726 
727 	/*-
728 	 * Don't add host routes for interface addresses of
729 	 * 0.0.0.0 --> 0.255.255.255 netmask 255.0.0.0.  This makes it
730 	 * possible to assign several such address pairs with consistent
731 	 * results (no host route) and is required by BOOTP.
732 	 *
733 	 * XXX: This is ugly !  There should be a way for the caller to
734 	 *      say that they don't want a host route.
735 	 */
736 	if (ia->ia_addr.sin_addr.s_addr != INADDR_ANY ||
737 	    ia->ia_netmask != IN_CLASSA_NET ||
738 	    ia->ia_dstaddr.sin_addr.s_addr != htonl(IN_CLASSA_HOST)) {
739 		if ((error = rtinit(&ia->ia_ifa, (int)RTM_ADD, flags)) != 0) {
740 			ia->ia_addr = oldaddr;
741 			return (error);
742 		}
743 		ia->ia_flags |= IFA_ROUTE;
744 	}
745 
746 	/*
747 	 * If the interface supports multicast, join the "all hosts"
748 	 * multicast group on that interface.
749 	 */
750 	if (ifp->if_flags & IFF_MULTICAST) {
751 		struct in_addr addr;
752 
753 		addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
754 		in_addmulti(&addr, ifp);
755 	}
756 	return (error);
757 }
758 
759 
760 /*
761  * Return 1 if the address might be a local broadcast address.
762  */
763 int
764 in_broadcast(struct in_addr in, struct ifnet *ifp)
765 {
766 	struct ifaddr *ifa;
767 	u_long t;
768 
769 	if (in.s_addr == INADDR_BROADCAST ||
770 	    in.s_addr == INADDR_ANY)
771 		return 1;
772 	if ((ifp->if_flags & IFF_BROADCAST) == 0)
773 		return 0;
774 	t = ntohl(in.s_addr);
775 	/*
776 	 * Look through the list of addresses for a match
777 	 * with a broadcast address.
778 	 */
779 #define ia ((struct in_ifaddr *)ifa)
780 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
781 		if (ifa->ifa_addr->sa_family == AF_INET &&
782 		    (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
783 		     in.s_addr == ia->ia_netbroadcast.s_addr ||
784 		     /*
785 		      * Check for old-style (host 0) broadcast.
786 		      */
787 		     t == ia->ia_subnet || t == ia->ia_net) &&
788 		     /*
789 		      * Check for an all one subnetmask. These
790 		      * only exist when an interface gets a secondary
791 		      * address.
792 		      */
793 		     ia->ia_subnetmask != (u_long)0xffffffff)
794 			    return 1;
795 	return (0);
796 #undef ia
797 }
798 /*
799  * Add an address to the list of IP multicast addresses for a given interface.
800  */
801 struct in_multi *
802 in_addmulti(struct in_addr *ap, struct ifnet *ifp)
803 {
804 	struct in_multi *inm;
805 	int error;
806 	struct sockaddr_in sin;
807 	struct ifmultiaddr *ifma;
808 
809 	/*
810 	 * Call generic routine to add membership or increment
811 	 * refcount.  It wants addresses in the form of a sockaddr,
812 	 * so we build one here (being careful to zero the unused bytes).
813 	 */
814 	bzero(&sin, sizeof sin);
815 	sin.sin_family = AF_INET;
816 	sin.sin_len = sizeof sin;
817 	sin.sin_addr = *ap;
818 	crit_enter();
819 	error = if_addmulti(ifp, (struct sockaddr *)&sin, &ifma);
820 	if (error) {
821 		crit_exit();
822 		return 0;
823 	}
824 
825 	/*
826 	 * If ifma->ifma_protospec is null, then if_addmulti() created
827 	 * a new record.  Otherwise, we are done.
828 	 */
829 	if (ifma->ifma_protospec != 0) {
830 		crit_exit();
831 		return ifma->ifma_protospec;
832 	}
833 
834 	/* XXX - if_addmulti uses M_WAITOK.  Can this really be called
835 	   at interrupt time?  If so, need to fix if_addmulti. XXX */
836 	inm = kmalloc(sizeof *inm, M_IPMADDR, M_WAITOK | M_ZERO);
837 	inm->inm_addr = *ap;
838 	inm->inm_ifp = ifp;
839 	inm->inm_ifma = ifma;
840 	ifma->ifma_protospec = inm;
841 	LIST_INSERT_HEAD(&in_multihead, inm, inm_link);
842 
843 	/*
844 	 * Let IGMP know that we have joined a new IP multicast group.
845 	 */
846 	igmp_joingroup(inm);
847 	crit_exit();
848 	return (inm);
849 }
850 
851 /*
852  * Delete a multicast address record.
853  */
854 void
855 in_delmulti(struct in_multi *inm)
856 {
857 	struct ifmultiaddr *ifma;
858 	struct in_multi my_inm;
859 
860 	crit_enter();
861 	ifma = inm->inm_ifma;
862 	my_inm.inm_ifp = NULL ; /* don't send the leave msg */
863 	if (ifma->ifma_refcount == 1) {
864 		/*
865 		 * No remaining claims to this record; let IGMP know that
866 		 * we are leaving the multicast group.
867 		 * But do it after the if_delmulti() which might reset
868 		 * the interface and nuke the packet.
869 		 */
870 		my_inm = *inm ;
871 		ifma->ifma_protospec = 0;
872 		LIST_REMOVE(inm, inm_link);
873 		kfree(inm, M_IPMADDR);
874 	}
875 	/* XXX - should be separate API for when we have an ifma? */
876 	if_delmulti(ifma->ifma_ifp, ifma->ifma_addr);
877 	if (my_inm.inm_ifp != NULL)
878 		igmp_leavegroup(&my_inm);
879 	crit_exit();
880 }
881 
882 void
883 in_ifdetach(struct ifnet *ifp)
884 {
885 	in_pcbpurgeif0(LIST_FIRST(&ripcbinfo.pcblisthead), ifp);
886 	in_pcbpurgeif0(LIST_FIRST(&udbinfo.pcblisthead), ifp);
887 }
888