in.c revision 107983
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: head/sys/netinet/in.c 107983 2002-12-17 19:30:04Z phk $
35 */
36
37#include <sys/param.h>
38#include <sys/systm.h>
39#include <sys/sockio.h>
40#include <sys/malloc.h>
41#include <sys/socket.h>
42#include <sys/kernel.h>
43#include <sys/sysctl.h>
44
45#include <net/if.h>
46#include <net/if_types.h>
47#include <net/route.h>
48
49#include <netinet/in.h>
50#include <netinet/in_var.h>
51#include <netinet/in_pcb.h>
52
53#include <netinet/igmp_var.h>
54
55static MALLOC_DEFINE(M_IPMADDR, "in_multi", "internet multicast address");
56
57static int in_mask2len(struct in_addr *);
58static void in_len2mask(struct in_addr *, int);
59static int in_lifaddr_ioctl(struct socket *, u_long, caddr_t,
60	struct ifnet *, struct thread *);
61
62static void	in_socktrim(struct sockaddr_in *);
63static int	in_ifinit(struct ifnet *,
64	    struct in_ifaddr *, struct sockaddr_in *, int);
65
66static int subnetsarelocal = 0;
67SYSCTL_INT(_net_inet_ip, OID_AUTO, subnets_are_local, CTLFLAG_RW,
68	&subnetsarelocal, 0, "");
69
70struct in_multihead in_multihead; /* XXX BSS initialization */
71
72extern struct inpcbinfo ripcbinfo;
73extern struct inpcbinfo udbinfo;
74
75/*
76 * Return 1 if an internet address is for a ``local'' host
77 * (one to which we have a connection).  If subnetsarelocal
78 * is true, this includes other subnets of the local net.
79 * Otherwise, it includes only the directly-connected (sub)nets.
80 */
81int
82in_localaddr(in)
83	struct in_addr in;
84{
85	register u_long i = ntohl(in.s_addr);
86	register struct in_ifaddr *ia;
87
88	if (subnetsarelocal) {
89		TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link)
90			if ((i & ia->ia_netmask) == ia->ia_net)
91				return (1);
92	} else {
93		TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link)
94			if ((i & ia->ia_subnetmask) == ia->ia_subnet)
95				return (1);
96	}
97	return (0);
98}
99
100/*
101 * Determine whether an IP address is in a reserved set of addresses
102 * that may not be forwarded, or whether datagrams to that destination
103 * may be forwarded.
104 */
105int
106in_canforward(in)
107	struct in_addr in;
108{
109	register u_long i = ntohl(in.s_addr);
110	register u_long net;
111
112	if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i))
113		return (0);
114	if (IN_CLASSA(i)) {
115		net = i & IN_CLASSA_NET;
116		if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
117			return (0);
118	}
119	return (1);
120}
121
122/*
123 * Trim a mask in a sockaddr
124 */
125static void
126in_socktrim(ap)
127struct sockaddr_in *ap;
128{
129    register char *cplim = (char *) &ap->sin_addr;
130    register char *cp = (char *) (&ap->sin_addr + 1);
131
132    ap->sin_len = 0;
133    while (--cp >= cplim)
134        if (*cp) {
135	    (ap)->sin_len = cp - (char *) (ap) + 1;
136	    break;
137	}
138}
139
140static int
141in_mask2len(mask)
142	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
162static void
163in_len2mask(mask, len)
164	struct in_addr *mask;
165	int len;
166{
167	int i;
168	u_char *p;
169
170	p = (u_char *)mask;
171	bzero(mask, sizeof(*mask));
172	for (i = 0; i < len / 8; i++)
173		p[i] = 0xff;
174	if (len % 8)
175		p[i] = (0xff00 >> (len % 8)) & 0xff;
176}
177
178/*
179 * Generic internet control operations (ioctl's).
180 * Ifp is 0 if not an interface-specific ioctl.
181 */
182/* ARGSUSED */
183int
184in_control(so, cmd, data, ifp, td)
185	struct socket *so;
186	u_long cmd;
187	caddr_t data;
188	register struct ifnet *ifp;
189	struct thread *td;
190{
191	register struct ifreq *ifr = (struct ifreq *)data;
192	register struct in_ifaddr *ia = 0, *iap;
193	register struct ifaddr *ifa;
194	struct in_addr dst;
195	struct in_ifaddr *oia;
196	struct in_aliasreq *ifra = (struct in_aliasreq *)data;
197	struct sockaddr_in oldaddr;
198	int error, hostIsNew, iaIsNew, maskIsNew, s;
199
200	iaIsNew = 0;
201
202	switch (cmd) {
203	case SIOCALIFADDR:
204	case SIOCDLIFADDR:
205		if (td && (error = suser(td)) != 0)
206			return error;
207		/*fall through*/
208	case SIOCGLIFADDR:
209		if (!ifp)
210			return EINVAL;
211		return in_lifaddr_ioctl(so, cmd, data, ifp, td);
212	}
213
214	/*
215	 * Find address for this interface, if it exists.
216	 *
217	 * If an alias address was specified, find that one instead of
218	 * the first one on the interface, if possible.
219	 */
220	if (ifp) {
221		dst = ((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr;
222		LIST_FOREACH(iap, INADDR_HASH(dst.s_addr), ia_hash)
223			if (iap->ia_ifp == ifp &&
224			    iap->ia_addr.sin_addr.s_addr == dst.s_addr) {
225				ia = iap;
226				break;
227			}
228		if (ia == NULL)
229			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
230				iap = ifatoia(ifa);
231				if (iap->ia_addr.sin_family == AF_INET) {
232					ia = iap;
233					break;
234				}
235			}
236	}
237
238	switch (cmd) {
239
240	case SIOCAIFADDR:
241	case SIOCDIFADDR:
242		if (ifp == 0)
243			return (EADDRNOTAVAIL);
244		if (ifra->ifra_addr.sin_family == AF_INET) {
245			for (oia = ia; ia; ia = TAILQ_NEXT(ia, ia_link)) {
246				if (ia->ia_ifp == ifp  &&
247				    ia->ia_addr.sin_addr.s_addr ==
248				    ifra->ifra_addr.sin_addr.s_addr)
249					break;
250			}
251			if ((ifp->if_flags & IFF_POINTOPOINT)
252			    && (cmd == SIOCAIFADDR)
253			    && (ifra->ifra_dstaddr.sin_addr.s_addr
254				== INADDR_ANY)) {
255				return EDESTADDRREQ;
256			}
257		}
258		if (cmd == SIOCDIFADDR && ia == 0)
259			return (EADDRNOTAVAIL);
260		/* FALLTHROUGH */
261	case SIOCSIFADDR:
262	case SIOCSIFNETMASK:
263	case SIOCSIFDSTADDR:
264		if (td && (error = suser(td)) != 0)
265			return error;
266
267		if (ifp == 0)
268			return (EADDRNOTAVAIL);
269		if (ia == (struct in_ifaddr *)0) {
270			ia = (struct in_ifaddr *)
271				malloc(sizeof *ia, M_IFADDR, M_WAITOK | M_ZERO);
272			if (ia == (struct in_ifaddr *)NULL)
273				return (ENOBUFS);
274			/*
275			 * Protect from ipintr() traversing address list
276			 * while we're modifying it.
277			 */
278			s = splnet();
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			splx(s);
295			iaIsNew = 1;
296		}
297		break;
298
299	case SIOCSIFBRDADDR:
300		if (td && (error = suser(td)) != 0)
301			return error;
302		/* FALLTHROUGH */
303
304	case SIOCGIFADDR:
305	case SIOCGIFNETMASK:
306	case SIOCGIFDSTADDR:
307	case SIOCGIFBRDADDR:
308		if (ia == (struct in_ifaddr *)0)
309			return (EADDRNOTAVAIL);
310		break;
311	}
312	switch (cmd) {
313
314	case SIOCGIFADDR:
315		*((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr;
316		return (0);
317
318	case SIOCGIFBRDADDR:
319		if ((ifp->if_flags & IFF_BROADCAST) == 0)
320			return (EINVAL);
321		*((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr;
322		return (0);
323
324	case SIOCGIFDSTADDR:
325		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
326			return (EINVAL);
327		*((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr;
328		return (0);
329
330	case SIOCGIFNETMASK:
331		*((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask;
332		return (0);
333
334	case SIOCSIFDSTADDR:
335		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
336			return (EINVAL);
337		oldaddr = ia->ia_dstaddr;
338		ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr;
339		if (ifp->if_ioctl && (error = (*ifp->if_ioctl)
340					(ifp, SIOCSIFDSTADDR, (caddr_t)ia))) {
341			ia->ia_dstaddr = oldaddr;
342			return (error);
343		}
344		if (ia->ia_flags & IFA_ROUTE) {
345			ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr;
346			rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
347			ia->ia_ifa.ifa_dstaddr =
348					(struct sockaddr *)&ia->ia_dstaddr;
349			rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP);
350		}
351		return (0);
352
353	case SIOCSIFBRDADDR:
354		if ((ifp->if_flags & IFF_BROADCAST) == 0)
355			return (EINVAL);
356		ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr;
357		return (0);
358
359	case SIOCSIFADDR:
360		error = in_ifinit(ifp, ia,
361		    (struct sockaddr_in *) &ifr->ifr_addr, 1);
362		if (error != 0 && iaIsNew)
363			break;
364		return (0);
365
366	case SIOCSIFNETMASK:
367		ia->ia_sockmask.sin_addr = ifra->ifra_addr.sin_addr;
368		ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr);
369		return (0);
370
371	case SIOCAIFADDR:
372		maskIsNew = 0;
373		hostIsNew = 1;
374		error = 0;
375		if (ia->ia_addr.sin_family == AF_INET) {
376			if (ifra->ifra_addr.sin_len == 0) {
377				ifra->ifra_addr = ia->ia_addr;
378				hostIsNew = 0;
379			} else if (ifra->ifra_addr.sin_addr.s_addr ==
380					       ia->ia_addr.sin_addr.s_addr)
381				hostIsNew = 0;
382		}
383		if (ifra->ifra_mask.sin_len) {
384			in_ifscrub(ifp, ia);
385			ia->ia_sockmask = ifra->ifra_mask;
386			ia->ia_sockmask.sin_family = AF_INET;
387			ia->ia_subnetmask =
388			     ntohl(ia->ia_sockmask.sin_addr.s_addr);
389			maskIsNew = 1;
390		}
391		if ((ifp->if_flags & IFF_POINTOPOINT) &&
392		    (ifra->ifra_dstaddr.sin_family == AF_INET)) {
393			in_ifscrub(ifp, ia);
394			ia->ia_dstaddr = ifra->ifra_dstaddr;
395			maskIsNew  = 1; /* We lie; but the effect's the same */
396		}
397		if (ifra->ifra_addr.sin_family == AF_INET &&
398		    (hostIsNew || maskIsNew))
399			error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
400		if (error != 0 && iaIsNew)
401			break;
402
403		if ((ifp->if_flags & IFF_BROADCAST) &&
404		    (ifra->ifra_broadaddr.sin_family == AF_INET))
405			ia->ia_broadaddr = ifra->ifra_broadaddr;
406		return (error);
407
408	case SIOCDIFADDR:
409		/*
410		 * in_ifscrub kills the interface route.
411		 */
412		in_ifscrub(ifp, ia);
413		/*
414		 * in_ifadown gets rid of all the rest of
415		 * the routes.  This is not quite the right
416		 * thing to do, but at least if we are running
417		 * a routing process they will come back.
418		 */
419		in_ifadown(&ia->ia_ifa, 1);
420		/*
421		 * XXX horrible hack to detect that we are being called
422		 * from if_detach()
423		 */
424		if (ifaddr_byindex(ifp->if_index) != NULL) {
425			in_pcbpurgeif0(&ripcbinfo, ifp);
426			in_pcbpurgeif0(&udbinfo, ifp);
427		}
428		error = 0;
429		break;
430
431	default:
432		if (ifp == 0 || ifp->if_ioctl == 0)
433			return (EOPNOTSUPP);
434		return ((*ifp->if_ioctl)(ifp, cmd, data));
435	}
436
437	/*
438	 * Protect from ipintr() traversing address list while we're modifying
439	 * it.
440	 */
441	s = splnet();
442	TAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifa_link);
443	TAILQ_REMOVE(&in_ifaddrhead, ia, ia_link);
444	LIST_REMOVE(ia, ia_hash);
445	IFAFREE(&ia->ia_ifa);
446	splx(s);
447
448	return (error);
449}
450
451/*
452 * SIOC[GAD]LIFADDR.
453 *	SIOCGLIFADDR: get first address. (?!?)
454 *	SIOCGLIFADDR with IFLR_PREFIX:
455 *		get first address that matches the specified prefix.
456 *	SIOCALIFADDR: add the specified address.
457 *	SIOCALIFADDR with IFLR_PREFIX:
458 *		EINVAL since we can't deduce hostid part of the address.
459 *	SIOCDLIFADDR: delete the specified address.
460 *	SIOCDLIFADDR with IFLR_PREFIX:
461 *		delete the first address that matches the specified prefix.
462 * return values:
463 *	EINVAL on invalid parameters
464 *	EADDRNOTAVAIL on prefix match failed/specified address not found
465 *	other values may be returned from in_ioctl()
466 */
467static int
468in_lifaddr_ioctl(so, cmd, data, ifp, td)
469	struct socket *so;
470	u_long cmd;
471	caddr_t	data;
472	struct ifnet *ifp;
473	struct thread *td;
474{
475	struct if_laddrreq *iflr = (struct if_laddrreq *)data;
476	struct ifaddr *ifa;
477
478	/* sanity checks */
479	if (!data || !ifp) {
480		panic("invalid argument to in_lifaddr_ioctl");
481		/*NOTRECHED*/
482	}
483
484	switch (cmd) {
485	case SIOCGLIFADDR:
486		/* address must be specified on GET with IFLR_PREFIX */
487		if ((iflr->flags & IFLR_PREFIX) == 0)
488			break;
489		/*FALLTHROUGH*/
490	case SIOCALIFADDR:
491	case SIOCDLIFADDR:
492		/* address must be specified on ADD and DELETE */
493		if (iflr->addr.ss_family != AF_INET)
494			return EINVAL;
495		if (iflr->addr.ss_len != sizeof(struct sockaddr_in))
496			return EINVAL;
497		/* XXX need improvement */
498		if (iflr->dstaddr.ss_family
499		 && iflr->dstaddr.ss_family != AF_INET)
500			return EINVAL;
501		if (iflr->dstaddr.ss_family
502		 && iflr->dstaddr.ss_len != sizeof(struct sockaddr_in))
503			return EINVAL;
504		break;
505	default: /*shouldn't happen*/
506		return EOPNOTSUPP;
507	}
508	if (sizeof(struct in_addr) * 8 < iflr->prefixlen)
509		return EINVAL;
510
511	switch (cmd) {
512	case SIOCALIFADDR:
513	    {
514		struct in_aliasreq ifra;
515
516		if (iflr->flags & IFLR_PREFIX)
517			return EINVAL;
518
519		/* copy args to in_aliasreq, perform ioctl(SIOCAIFADDR_IN6). */
520		bzero(&ifra, sizeof(ifra));
521		bcopy(iflr->iflr_name, ifra.ifra_name,
522			sizeof(ifra.ifra_name));
523
524		bcopy(&iflr->addr, &ifra.ifra_addr, iflr->addr.ss_len);
525
526		if (iflr->dstaddr.ss_family) {	/*XXX*/
527			bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
528				iflr->dstaddr.ss_len);
529		}
530
531		ifra.ifra_mask.sin_family = AF_INET;
532		ifra.ifra_mask.sin_len = sizeof(struct sockaddr_in);
533		in_len2mask(&ifra.ifra_mask.sin_addr, iflr->prefixlen);
534
535		return in_control(so, SIOCAIFADDR, (caddr_t)&ifra, ifp, td);
536	    }
537	case SIOCGLIFADDR:
538	case SIOCDLIFADDR:
539	    {
540		struct in_ifaddr *ia;
541		struct in_addr mask, candidate, match;
542		struct sockaddr_in *sin;
543		int cmp;
544
545		bzero(&mask, sizeof(mask));
546		if (iflr->flags & IFLR_PREFIX) {
547			/* lookup a prefix rather than address. */
548			in_len2mask(&mask, iflr->prefixlen);
549
550			sin = (struct sockaddr_in *)&iflr->addr;
551			match.s_addr = sin->sin_addr.s_addr;
552			match.s_addr &= mask.s_addr;
553
554			/* if you set extra bits, that's wrong */
555			if (match.s_addr != sin->sin_addr.s_addr)
556				return EINVAL;
557
558			cmp = 1;
559		} else {
560			if (cmd == SIOCGLIFADDR) {
561				/* on getting an address, take the 1st match */
562				cmp = 0;	/*XXX*/
563			} else {
564				/* on deleting an address, do exact match */
565				in_len2mask(&mask, 32);
566				sin = (struct sockaddr_in *)&iflr->addr;
567				match.s_addr = sin->sin_addr.s_addr;
568
569				cmp = 1;
570			}
571		}
572
573		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)	{
574			if (ifa->ifa_addr->sa_family != AF_INET6)
575				continue;
576			if (!cmp)
577				break;
578			candidate.s_addr = ((struct sockaddr_in *)&ifa->ifa_addr)->sin_addr.s_addr;
579			candidate.s_addr &= mask.s_addr;
580			if (candidate.s_addr == match.s_addr)
581				break;
582		}
583		if (!ifa)
584			return EADDRNOTAVAIL;
585		ia = (struct in_ifaddr *)ifa;
586
587		if (cmd == SIOCGLIFADDR) {
588			/* fill in the if_laddrreq structure */
589			bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin_len);
590
591			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
592				bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
593					ia->ia_dstaddr.sin_len);
594			} else
595				bzero(&iflr->dstaddr, sizeof(iflr->dstaddr));
596
597			iflr->prefixlen =
598				in_mask2len(&ia->ia_sockmask.sin_addr);
599
600			iflr->flags = 0;	/*XXX*/
601
602			return 0;
603		} else {
604			struct in_aliasreq ifra;
605
606			/* fill in_aliasreq and do ioctl(SIOCDIFADDR_IN6) */
607			bzero(&ifra, sizeof(ifra));
608			bcopy(iflr->iflr_name, ifra.ifra_name,
609				sizeof(ifra.ifra_name));
610
611			bcopy(&ia->ia_addr, &ifra.ifra_addr,
612				ia->ia_addr.sin_len);
613			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
614				bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
615					ia->ia_dstaddr.sin_len);
616			}
617			bcopy(&ia->ia_sockmask, &ifra.ifra_dstaddr,
618				ia->ia_sockmask.sin_len);
619
620			return in_control(so, SIOCDIFADDR, (caddr_t)&ifra,
621					  ifp, td);
622		}
623	    }
624	}
625
626	return EOPNOTSUPP;	/*just for safety*/
627}
628
629/*
630 * Delete any existing route for an interface.
631 */
632void
633in_ifscrub(ifp, ia)
634	register struct ifnet *ifp;
635	register struct in_ifaddr *ia;
636{
637
638	if ((ia->ia_flags & IFA_ROUTE) == 0)
639		return;
640	if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT))
641		rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
642	else
643		rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0);
644	ia->ia_flags &= ~IFA_ROUTE;
645}
646
647/*
648 * Initialize an interface's internet address
649 * and routing table entry.
650 */
651static int
652in_ifinit(ifp, ia, sin, scrub)
653	register struct ifnet *ifp;
654	register struct in_ifaddr *ia;
655	struct sockaddr_in *sin;
656	int scrub;
657{
658	register u_long i = ntohl(sin->sin_addr.s_addr);
659	struct sockaddr_in oldaddr;
660	int s = splimp(), flags = RTF_UP, error = 0;
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))) {
676		splx(s);
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	splx(s);
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 */
763int
764in_broadcast(in, ifp)
765	struct in_addr in;
766        struct ifnet *ifp;
767{
768	register struct ifaddr *ifa;
769	u_long t;
770
771	if (in.s_addr == INADDR_BROADCAST ||
772	    in.s_addr == INADDR_ANY)
773		return 1;
774	if ((ifp->if_flags & IFF_BROADCAST) == 0)
775		return 0;
776	t = ntohl(in.s_addr);
777	/*
778	 * Look through the list of addresses for a match
779	 * with a broadcast address.
780	 */
781#define ia ((struct in_ifaddr *)ifa)
782	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
783		if (ifa->ifa_addr->sa_family == AF_INET &&
784		    (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
785		     in.s_addr == ia->ia_netbroadcast.s_addr ||
786		     /*
787		      * Check for old-style (host 0) broadcast.
788		      */
789		     t == ia->ia_subnet || t == ia->ia_net) &&
790		     /*
791		      * Check for an all one subnetmask. These
792		      * only exist when an interface gets a secondary
793		      * address.
794		      */
795		     ia->ia_subnetmask != (u_long)0xffffffff)
796			    return 1;
797	return (0);
798#undef ia
799}
800/*
801 * Add an address to the list of IP multicast addresses for a given interface.
802 */
803struct in_multi *
804in_addmulti(ap, ifp)
805	register struct in_addr *ap;
806	register struct ifnet *ifp;
807{
808	register struct in_multi *inm;
809	int error;
810	struct sockaddr_in sin;
811	struct ifmultiaddr *ifma;
812	int s = splnet();
813
814	/*
815	 * Call generic routine to add membership or increment
816	 * refcount.  It wants addresses in the form of a sockaddr,
817	 * so we build one here (being careful to zero the unused bytes).
818	 */
819	bzero(&sin, sizeof sin);
820	sin.sin_family = AF_INET;
821	sin.sin_len = sizeof sin;
822	sin.sin_addr = *ap;
823	error = if_addmulti(ifp, (struct sockaddr *)&sin, &ifma);
824	if (error) {
825		splx(s);
826		return 0;
827	}
828
829	/*
830	 * If ifma->ifma_protospec is null, then if_addmulti() created
831	 * a new record.  Otherwise, we are done.
832	 */
833	if (ifma->ifma_protospec != 0) {
834		splx(s);
835		return ifma->ifma_protospec;
836	}
837
838	/* XXX - if_addmulti uses M_WAITOK.  Can this really be called
839	   at interrupt time?  If so, need to fix if_addmulti. XXX */
840	inm = (struct in_multi *)malloc(sizeof(*inm), M_IPMADDR,
841	    M_NOWAIT | M_ZERO);
842	if (inm == NULL) {
843		splx(s);
844		return (NULL);
845	}
846
847	inm->inm_addr = *ap;
848	inm->inm_ifp = ifp;
849	inm->inm_ifma = ifma;
850	ifma->ifma_protospec = inm;
851	LIST_INSERT_HEAD(&in_multihead, inm, inm_link);
852
853	/*
854	 * Let IGMP know that we have joined a new IP multicast group.
855	 */
856	igmp_joingroup(inm);
857	splx(s);
858	return (inm);
859}
860
861/*
862 * Delete a multicast address record.
863 */
864void
865in_delmulti(inm)
866	register struct in_multi *inm;
867{
868	struct ifmultiaddr *ifma = inm->inm_ifma;
869	struct in_multi my_inm;
870	int s = splnet();
871
872	my_inm.inm_ifp = NULL ; /* don't send the leave msg */
873	if (ifma->ifma_refcount == 1) {
874		/*
875		 * No remaining claims to this record; let IGMP know that
876		 * we are leaving the multicast group.
877		 * But do it after the if_delmulti() which might reset
878		 * the interface and nuke the packet.
879		 */
880		my_inm = *inm ;
881		ifma->ifma_protospec = 0;
882		LIST_REMOVE(inm, inm_link);
883		free(inm, M_IPMADDR);
884	}
885	/* XXX - should be separate API for when we have an ifma? */
886	if_delmulti(ifma->ifma_ifp, ifma->ifma_addr);
887	if (my_inm.inm_ifp != NULL)
888		igmp_leavegroup(&my_inm);
889	splx(s);
890}
891