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
| 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
|
45#include <sys/kernel.h>
46#include <sys/sysctl.h>
47
48#include <net/if.h>
49#include <net/route.h>
50
51#include <netinet/in_systm.h>
52#include <netinet/in.h>
53#include <netinet/in_var.h>
54#include <netinet/if_ether.h>
55
56#include <netinet/igmp_var.h>
57
58/*
59 * This structure is used to keep track of in_multi chains which belong to
60 * deleted interface addresses.
61 */
62static LIST_HEAD(, multi_kludge) in_mk; /* XXX BSS initialization */
63
64struct multi_kludge {
65 LIST_ENTRY(multi_kludge) mk_entry;
66 struct ifnet *mk_ifp;
67 struct in_multihead mk_head;
68};
69
70static void in_socktrim __P((struct sockaddr_in *));
71static int in_ifinit __P((struct ifnet *,
72 struct in_ifaddr *, struct sockaddr_in *, int));
73static void in_ifscrub __P((struct ifnet *, struct in_ifaddr *));
74
75static int subnetsarelocal = 1;
76SYSCTL_INT(_net_inet_ip, OID_AUTO, subnets_are_local, CTLFLAG_RW,
77 &subnetsarelocal, 0, "");
78/*
79 * Return 1 if an internet address is for a ``local'' host
80 * (one to which we have a connection). If subnetsarelocal
81 * is true, this includes other subnets of the local net.
82 * Otherwise, it includes only the directly-connected (sub)nets.
83 */
84int
85in_localaddr(in)
86 struct in_addr in;
87{
88 register u_long i = ntohl(in.s_addr);
89 register struct in_ifaddr *ia;
90
91 if (subnetsarelocal) {
92 for (ia = in_ifaddr; ia; ia = ia->ia_next)
93 if ((i & ia->ia_netmask) == ia->ia_net)
94 return (1);
95 } else {
96 for (ia = in_ifaddr; ia; ia = ia->ia_next)
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 */
108int
109in_canforward(in)
110 struct in_addr in;
111{
112 register u_long i = ntohl(in.s_addr);
113 register u_long net;
114
115 if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i))
116 return (0);
117 if (IN_CLASSA(i)) {
118 net = i & IN_CLASSA_NET;
119 if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
120 return (0);
121 }
122 return (1);
123}
124
125/*
126 * Trim a mask in a sockaddr
127 */
128static void
129in_socktrim(ap)
130struct sockaddr_in *ap;
131{
132 register char *cplim = (char *) &ap->sin_addr;
133 register char *cp = (char *) (&ap->sin_addr + 1);
134
135 ap->sin_len = 0;
136 while (--cp >= cplim)
137 if (*cp) {
138 (ap)->sin_len = cp - (char *) (ap) + 1;
139 break;
140 }
141}
142
143static int in_interfaces; /* number of external internet interfaces */
144
145/*
146 * Generic internet control operations (ioctl's).
147 * Ifp is 0 if not an interface-specific ioctl.
148 */
149/* ARGSUSED */
150int
151in_control(so, cmd, data, ifp)
152 struct socket *so;
153 u_long cmd;
154 caddr_t data;
155 register struct ifnet *ifp;
156{
157 register struct ifreq *ifr = (struct ifreq *)data;
158 register struct in_ifaddr *ia = 0;
159 register struct ifaddr *ifa;
160 struct in_ifaddr *oia;
161 struct in_aliasreq *ifra = (struct in_aliasreq *)data;
162 struct sockaddr_in oldaddr;
163 int error, hostIsNew, maskIsNew;
164 u_long i;
165 struct multi_kludge *mk;
166
167 /*
168 * Find address for this interface, if it exists.
169 */
170 if (ifp)
171 for (ia = in_ifaddr; ia; ia = ia->ia_next)
172 if (ia->ia_ifp == ifp)
173 break;
174
175 switch (cmd) {
176
177 case SIOCAIFADDR:
178 case SIOCDIFADDR:
179 if (ifra->ifra_addr.sin_family == AF_INET) {
180 for (oia = ia; ia; ia = ia->ia_next) {
181 if (ia->ia_ifp == ifp &&
182 ia->ia_addr.sin_addr.s_addr ==
183 ifra->ifra_addr.sin_addr.s_addr)
184 break;
185 }
186 if ((ifp->if_flags & IFF_POINTOPOINT)
187 && (cmd == SIOCAIFADDR)
188 && (ifra->ifra_dstaddr.sin_addr.s_addr
189 == INADDR_ANY)) {
190 return EDESTADDRREQ;
191 }
192 }
193 if (cmd == SIOCDIFADDR && ia == 0)
194 return (EADDRNOTAVAIL);
195 /* FALLTHROUGH */
196 case SIOCSIFADDR:
197 case SIOCSIFNETMASK:
198 case SIOCSIFDSTADDR:
199 if ((so->so_state & SS_PRIV) == 0)
200 return (EPERM);
201
202 if (ifp == 0)
203 panic("in_control");
204 if (ia == (struct in_ifaddr *)0) {
205 oia = (struct in_ifaddr *)
206 malloc(sizeof *oia, M_IFADDR, M_WAITOK);
207 if (oia == (struct in_ifaddr *)NULL)
208 return (ENOBUFS);
209 bzero((caddr_t)oia, sizeof *oia);
210 ia = in_ifaddr;
211 if (ia) {
212 for ( ; ia->ia_next; ia = ia->ia_next)
213 continue;
214 ia->ia_next = oia;
215 } else
216 in_ifaddr = oia;
217 ia = oia;
218 ifa = ifp->if_addrlist;
219 if (ifa) {
220 for ( ; ifa->ifa_next; ifa = ifa->ifa_next)
221 continue;
222 ifa->ifa_next = (struct ifaddr *) ia;
223 } else
224 ifp->if_addrlist = (struct ifaddr *) ia;
225 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
226 ia->ia_ifa.ifa_dstaddr
227 = (struct sockaddr *)&ia->ia_dstaddr;
228 ia->ia_ifa.ifa_netmask
229 = (struct sockaddr *)&ia->ia_sockmask;
230 ia->ia_sockmask.sin_len = 8;
231 if (ifp->if_flags & IFF_BROADCAST) {
232 ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr);
233 ia->ia_broadaddr.sin_family = AF_INET;
234 }
235 ia->ia_ifp = ifp;
236 if (!(ifp->if_flags & IFF_LOOPBACK))
237 in_interfaces++;
238 }
239 break;
240
241 case SIOCSIFBRDADDR:
242 if ((so->so_state & SS_PRIV) == 0)
243 return (EPERM);
244 /* FALLTHROUGH */
245
246 case SIOCGIFADDR:
247 case SIOCGIFNETMASK:
248 case SIOCGIFDSTADDR:
249 case SIOCGIFBRDADDR:
250 if (ia == (struct in_ifaddr *)0)
251 return (EADDRNOTAVAIL);
252 break;
253 }
254 switch (cmd) {
255
256 case SIOCGIFADDR:
257 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr;
258 break;
259
260 case SIOCGIFBRDADDR:
261 if ((ifp->if_flags & IFF_BROADCAST) == 0)
262 return (EINVAL);
263 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr;
264 break;
265
266 case SIOCGIFDSTADDR:
267 if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
268 return (EINVAL);
269 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr;
270 break;
271
272 case SIOCGIFNETMASK:
273 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask;
274 break;
275
276 case SIOCSIFDSTADDR:
277 if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
278 return (EINVAL);
279 oldaddr = ia->ia_dstaddr;
280 ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr;
281 if (ifp->if_ioctl && (error = (*ifp->if_ioctl)
282 (ifp, SIOCSIFDSTADDR, (caddr_t)ia))) {
283 ia->ia_dstaddr = oldaddr;
284 return (error);
285 }
286 if (ia->ia_flags & IFA_ROUTE) {
287 ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr;
288 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
289 ia->ia_ifa.ifa_dstaddr =
290 (struct sockaddr *)&ia->ia_dstaddr;
291 rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP);
292 }
293 break;
294
295 case SIOCSIFBRDADDR:
296 if ((ifp->if_flags & IFF_BROADCAST) == 0)
297 return (EINVAL);
298 ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr;
299 break;
300
301 case SIOCSIFADDR:
302 return (in_ifinit(ifp, ia,
303 (struct sockaddr_in *) &ifr->ifr_addr, 1));
304
305 case SIOCSIFNETMASK:
306 i = ifra->ifra_addr.sin_addr.s_addr;
307 ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr = i);
308 break;
309
310 case SIOCAIFADDR:
311 maskIsNew = 0;
312 hostIsNew = 1;
313 error = 0;
314 if (ia->ia_addr.sin_family == AF_INET) {
315 if (ifra->ifra_addr.sin_len == 0) {
316 ifra->ifra_addr = ia->ia_addr;
317 hostIsNew = 0;
318 } else if (ifra->ifra_addr.sin_addr.s_addr ==
319 ia->ia_addr.sin_addr.s_addr)
320 hostIsNew = 0;
321 }
322 if (ifra->ifra_mask.sin_len) {
323 in_ifscrub(ifp, ia);
324 ia->ia_sockmask = ifra->ifra_mask;
325 ia->ia_subnetmask =
326 ntohl(ia->ia_sockmask.sin_addr.s_addr);
327 maskIsNew = 1;
328 }
329 if ((ifp->if_flags & IFF_POINTOPOINT) &&
330 (ifra->ifra_dstaddr.sin_family == AF_INET)) {
331 in_ifscrub(ifp, ia);
332 ia->ia_dstaddr = ifra->ifra_dstaddr;
333 maskIsNew = 1; /* We lie; but the effect's the same */
334 }
335 if (ifra->ifra_addr.sin_family == AF_INET &&
336 (hostIsNew || maskIsNew))
337 error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
338 if ((ifp->if_flags & IFF_BROADCAST) &&
339 (ifra->ifra_broadaddr.sin_family == AF_INET))
340 ia->ia_broadaddr = ifra->ifra_broadaddr;
341 return (error);
342
343 case SIOCDIFADDR:
344 mk = malloc(sizeof *mk, M_IPMADDR, M_WAITOK);
345 if (!mk)
346 return ENOBUFS;
347
348 in_ifscrub(ifp, ia);
349 if ((ifa = ifp->if_addrlist) == (struct ifaddr *)ia)
350 ifp->if_addrlist = ifa->ifa_next;
351 else {
352 while (ifa->ifa_next &&
353 (ifa->ifa_next != (struct ifaddr *)ia))
354 ifa = ifa->ifa_next;
355 if (ifa->ifa_next)
356 ifa->ifa_next = ((struct ifaddr *)ia)->ifa_next;
357 else
358 printf("Couldn't unlink inifaddr from ifp\n");
359 }
360 oia = ia;
361 if (oia == (ia = in_ifaddr))
362 in_ifaddr = ia->ia_next;
363 else {
364 while (ia->ia_next && (ia->ia_next != oia))
365 ia = ia->ia_next;
366 if (ia->ia_next)
367 ia->ia_next = oia->ia_next;
368 else
369 printf("Didn't unlink inifadr from list\n");
370 }
371
372 if (!oia->ia_multiaddrs.lh_first) {
373 IFAFREE(&oia->ia_ifa);
374 FREE(mk, M_IPMADDR);
375 break;
376 }
377
378 /*
379 * Multicast address kludge:
380 * If there were any multicast addresses attached to this
381 * interface address, either move them to another address
382 * on this interface, or save them until such time as this
383 * interface is reconfigured for IP.
384 */
385 IFP_TO_IA(oia->ia_ifp, ia);
386 if (ia) { /* there is another address */
387 struct in_multi *inm;
388 for(inm = oia->ia_multiaddrs.lh_first; inm;
389 inm = inm->inm_entry.le_next) {
390 IFAFREE(&inm->inm_ia->ia_ifa);
391 ia->ia_ifa.ifa_refcnt++;
392 inm->inm_ia = ia;
393 LIST_INSERT_HEAD(&ia->ia_multiaddrs, inm,
394 inm_entry);
395 }
396 FREE(mk, M_IPMADDR);
397 } else { /* last address on this if deleted, save */
398 struct in_multi *inm;
399
400 LIST_INIT(&mk->mk_head);
401 mk->mk_ifp = ifp;
402
403 for(inm = oia->ia_multiaddrs.lh_first; inm;
404 inm = inm->inm_entry.le_next) {
405 LIST_INSERT_HEAD(&mk->mk_head, inm, inm_entry);
406 }
407
408 if (mk->mk_head.lh_first) {
409 LIST_INSERT_HEAD(&in_mk, mk, mk_entry);
410 } else {
411 FREE(mk, M_IPMADDR);
412 }
413 }
414
415 IFAFREE((&oia->ia_ifa));
416 break;
417
418 default:
419 if (ifp == 0 || ifp->if_ioctl == 0)
420 return (EOPNOTSUPP);
421 return ((*ifp->if_ioctl)(ifp, cmd, data));
422 }
423 return (0);
424}
425
426/*
427 * Delete any existing route for an interface.
428 */
429static void
430in_ifscrub(ifp, ia)
431 register struct ifnet *ifp;
432 register struct in_ifaddr *ia;
433{
434
435 if ((ia->ia_flags & IFA_ROUTE) == 0)
436 return;
437 if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT))
438 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
439 else
440 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0);
441 ia->ia_flags &= ~IFA_ROUTE;
442}
443
444/*
445 * Initialize an interface's internet address
446 * and routing table entry.
447 */
448static int
449in_ifinit(ifp, ia, sin, scrub)
450 register struct ifnet *ifp;
451 register struct in_ifaddr *ia;
452 struct sockaddr_in *sin;
453 int scrub;
454{
455 register u_long i = ntohl(sin->sin_addr.s_addr);
456 struct sockaddr_in oldaddr;
457 int s = splimp(), flags = RTF_UP, error;
458 struct multi_kludge *mk;
459
460 oldaddr = ia->ia_addr;
461 ia->ia_addr = *sin;
462 /*
463 * Give the interface a chance to initialize
464 * if this is its first address,
465 * and to validate the address if necessary.
466 */
467 if (ifp->if_ioctl &&
468 (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia))) {
469 splx(s);
470 ia->ia_addr = oldaddr;
471 return (error);
472 }
473 splx(s);
474 if (scrub) {
475 ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr;
476 in_ifscrub(ifp, ia);
477 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
478 }
479 if (IN_CLASSA(i))
480 ia->ia_netmask = IN_CLASSA_NET;
481 else if (IN_CLASSB(i))
482 ia->ia_netmask = IN_CLASSB_NET;
483 else
484 ia->ia_netmask = IN_CLASSC_NET;
485 /*
486 * The subnet mask usually includes at least the standard network part,
487 * but may may be smaller in the case of supernetting.
488 * If it is set, we believe it.
489 */
490 if (ia->ia_subnetmask == 0) {
491 ia->ia_subnetmask = ia->ia_netmask;
492 ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
493 } else
494 ia->ia_netmask &= ia->ia_subnetmask;
495 ia->ia_net = i & ia->ia_netmask;
496 ia->ia_subnet = i & ia->ia_subnetmask;
497 in_socktrim(&ia->ia_sockmask);
498 /*
499 * Add route for the network.
500 */
501 ia->ia_ifa.ifa_metric = ifp->if_metric;
502 if (ifp->if_flags & IFF_BROADCAST) {
503 ia->ia_broadaddr.sin_addr.s_addr =
504 htonl(ia->ia_subnet | ~ia->ia_subnetmask);
505 ia->ia_netbroadcast.s_addr =
506 htonl(ia->ia_net | ~ ia->ia_netmask);
507 } else if (ifp->if_flags & IFF_LOOPBACK) {
508 ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr;
509 flags |= RTF_HOST;
510 } else if (ifp->if_flags & IFF_POINTOPOINT) {
511 if (ia->ia_dstaddr.sin_family != AF_INET)
512 return (0);
513 flags |= RTF_HOST;
514 }
515 if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD, flags)) == 0)
516 ia->ia_flags |= IFA_ROUTE;
517
518 LIST_INIT(&ia->ia_multiaddrs);
519 /*
520 * If the interface supports multicast, join the "all hosts"
521 * multicast group on that interface.
522 */
523 if (ifp->if_flags & IFF_MULTICAST) {
524 struct in_addr addr;
525
526 /*
527 * Continuation of multicast address hack:
528 * If there was a multicast group list previously saved
529 * for this interface, then we re-attach it to the first
530 * address configured on the i/f.
531 */
532 for(mk = in_mk.lh_first; mk; mk = mk->mk_entry.le_next) {
533 if(mk->mk_ifp == ifp) {
534 struct in_multi *inm;
535
536 for(inm = mk->mk_head.lh_first; inm;
537 inm = inm->inm_entry.le_next) {
538 IFAFREE(&inm->inm_ia->ia_ifa);
539 ia->ia_ifa.ifa_refcnt++;
540 inm->inm_ia = ia;
541 LIST_INSERT_HEAD(&ia->ia_multiaddrs,
542 inm, inm_entry);
543 }
544 LIST_REMOVE(mk, mk_entry);
545 free(mk, M_IPMADDR);
546 break;
547 }
548 }
549
550 addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
551 in_addmulti(&addr, ifp);
552 }
553 return (error);
554}
555
556
557/*
558 * Return 1 if the address might be a local broadcast address.
559 */
560int
561in_broadcast(in, ifp)
562 struct in_addr in;
563 struct ifnet *ifp;
564{
565 register struct ifaddr *ifa;
566 u_long t;
567
568 if (in.s_addr == INADDR_BROADCAST ||
569 in.s_addr == INADDR_ANY)
570 return 1;
571 if ((ifp->if_flags & IFF_BROADCAST) == 0)
572 return 0;
573 t = ntohl(in.s_addr);
574 /*
575 * Look through the list of addresses for a match
576 * with a broadcast address.
577 */
578#define ia ((struct in_ifaddr *)ifa)
579 for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next)
580 if (ifa->ifa_addr->sa_family == AF_INET &&
581 (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
582 in.s_addr == ia->ia_netbroadcast.s_addr ||
583 /*
584 * Check for old-style (host 0) broadcast.
585 */
586 t == ia->ia_subnet || t == ia->ia_net) &&
587 /*
588 * Check for an all one subnetmask. These
589 * only exist when an interface gets a secondary
590 * address.
591 */
592 ia->ia_subnetmask != (u_long)0xffffffff)
593 return 1;
594 return (0);
595#undef ia
596}
597/*
598 * Add an address to the list of IP multicast addresses for a given interface.
599 */
600struct in_multi *
601in_addmulti(ap, ifp)
602 register struct in_addr *ap;
603 register struct ifnet *ifp;
604{
605 register struct in_multi *inm;
606 struct ifreq ifr;
607 struct in_ifaddr *ia;
608 int s = splnet();
609
610 /*
611 * See if address already in list.
612 */
613 IN_LOOKUP_MULTI(*ap, ifp, inm);
614 if (inm != NULL) {
615 /*
616 * Found it; just increment the reference count.
617 */
618 ++inm->inm_refcount;
619 }
620 else {
621 /*
622 * New address; allocate a new multicast record
623 * and link it into the interface's multicast list.
624 */
625 inm = (struct in_multi *)malloc(sizeof(*inm),
626 M_IPMADDR, M_NOWAIT);
627 if (inm == NULL) {
628 splx(s);
629 return (NULL);
630 }
631 inm->inm_addr = *ap;
632 inm->inm_ifp = ifp;
633 inm->inm_refcount = 1;
634 IFP_TO_IA(ifp, ia);
635 if (ia == NULL) {
636 free(inm, M_IPMADDR);
637 splx(s);
638 return (NULL);
639 }
640 inm->inm_ia = ia;
641 ia->ia_ifa.ifa_refcnt++; /* gain a reference */
642 LIST_INSERT_HEAD(&ia->ia_multiaddrs, inm, inm_entry);
643
644 /*
645 * Ask the network driver to update its multicast reception
646 * filter appropriately for the new address.
647 */
648 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_family = AF_INET;
649 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr = *ap;
650 if ((ifp->if_ioctl == NULL) ||
651 (*ifp->if_ioctl)(ifp, SIOCADDMULTI,(caddr_t)&ifr) != 0) {
652 LIST_REMOVE(inm, inm_entry);
653 IFAFREE(&ia->ia_ifa); /* release reference */
654 free(inm, M_IPMADDR);
655 splx(s);
656 return (NULL);
657 }
658 /*
659 * Let IGMP know that we have joined a new IP multicast group.
660 */
661 igmp_joingroup(inm);
662 }
663 splx(s);
664 return (inm);
665}
666
667/*
668 * Delete a multicast address record.
669 */
670void
671in_delmulti(inm)
672 register struct in_multi *inm;
673{
674 struct ifreq ifr;
675 int s = splnet();
676
677 if (--inm->inm_refcount == 0) {
678 /*
679 * No remaining claims to this record; let IGMP know that
680 * we are leaving the multicast group.
681 */
682 igmp_leavegroup(inm);
683 /*
684 * Unlink from list.
685 */
686 LIST_REMOVE(inm, inm_entry);
687 IFAFREE(&inm->inm_ia->ia_ifa); /* release reference */
688
689 /*
690 * Notify the network driver to update its multicast reception
691 * filter.
692 */
693 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_family = AF_INET;
694 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_addr =
695 inm->inm_addr;
696 (*inm->inm_ifp->if_ioctl)(inm->inm_ifp, SIOCDELMULTI,
697 (caddr_t)&ifr);
698 free(inm, M_IPMADDR);
699 }
700 splx(s);
701}
| 45#include <sys/kernel.h>
46#include <sys/sysctl.h>
47
48#include <net/if.h>
49#include <net/route.h>
50
51#include <netinet/in_systm.h>
52#include <netinet/in.h>
53#include <netinet/in_var.h>
54#include <netinet/if_ether.h>
55
56#include <netinet/igmp_var.h>
57
58/*
59 * This structure is used to keep track of in_multi chains which belong to
60 * deleted interface addresses.
61 */
62static LIST_HEAD(, multi_kludge) in_mk; /* XXX BSS initialization */
63
64struct multi_kludge {
65 LIST_ENTRY(multi_kludge) mk_entry;
66 struct ifnet *mk_ifp;
67 struct in_multihead mk_head;
68};
69
70static void in_socktrim __P((struct sockaddr_in *));
71static int in_ifinit __P((struct ifnet *,
72 struct in_ifaddr *, struct sockaddr_in *, int));
73static void in_ifscrub __P((struct ifnet *, struct in_ifaddr *));
74
75static int subnetsarelocal = 1;
76SYSCTL_INT(_net_inet_ip, OID_AUTO, subnets_are_local, CTLFLAG_RW,
77 &subnetsarelocal, 0, "");
78/*
79 * Return 1 if an internet address is for a ``local'' host
80 * (one to which we have a connection). If subnetsarelocal
81 * is true, this includes other subnets of the local net.
82 * Otherwise, it includes only the directly-connected (sub)nets.
83 */
84int
85in_localaddr(in)
86 struct in_addr in;
87{
88 register u_long i = ntohl(in.s_addr);
89 register struct in_ifaddr *ia;
90
91 if (subnetsarelocal) {
92 for (ia = in_ifaddr; ia; ia = ia->ia_next)
93 if ((i & ia->ia_netmask) == ia->ia_net)
94 return (1);
95 } else {
96 for (ia = in_ifaddr; ia; ia = ia->ia_next)
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 */
108int
109in_canforward(in)
110 struct in_addr in;
111{
112 register u_long i = ntohl(in.s_addr);
113 register u_long net;
114
115 if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i))
116 return (0);
117 if (IN_CLASSA(i)) {
118 net = i & IN_CLASSA_NET;
119 if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
120 return (0);
121 }
122 return (1);
123}
124
125/*
126 * Trim a mask in a sockaddr
127 */
128static void
129in_socktrim(ap)
130struct sockaddr_in *ap;
131{
132 register char *cplim = (char *) &ap->sin_addr;
133 register char *cp = (char *) (&ap->sin_addr + 1);
134
135 ap->sin_len = 0;
136 while (--cp >= cplim)
137 if (*cp) {
138 (ap)->sin_len = cp - (char *) (ap) + 1;
139 break;
140 }
141}
142
143static int in_interfaces; /* number of external internet interfaces */
144
145/*
146 * Generic internet control operations (ioctl's).
147 * Ifp is 0 if not an interface-specific ioctl.
148 */
149/* ARGSUSED */
150int
151in_control(so, cmd, data, ifp)
152 struct socket *so;
153 u_long cmd;
154 caddr_t data;
155 register struct ifnet *ifp;
156{
157 register struct ifreq *ifr = (struct ifreq *)data;
158 register struct in_ifaddr *ia = 0;
159 register struct ifaddr *ifa;
160 struct in_ifaddr *oia;
161 struct in_aliasreq *ifra = (struct in_aliasreq *)data;
162 struct sockaddr_in oldaddr;
163 int error, hostIsNew, maskIsNew;
164 u_long i;
165 struct multi_kludge *mk;
166
167 /*
168 * Find address for this interface, if it exists.
169 */
170 if (ifp)
171 for (ia = in_ifaddr; ia; ia = ia->ia_next)
172 if (ia->ia_ifp == ifp)
173 break;
174
175 switch (cmd) {
176
177 case SIOCAIFADDR:
178 case SIOCDIFADDR:
179 if (ifra->ifra_addr.sin_family == AF_INET) {
180 for (oia = ia; ia; ia = ia->ia_next) {
181 if (ia->ia_ifp == ifp &&
182 ia->ia_addr.sin_addr.s_addr ==
183 ifra->ifra_addr.sin_addr.s_addr)
184 break;
185 }
186 if ((ifp->if_flags & IFF_POINTOPOINT)
187 && (cmd == SIOCAIFADDR)
188 && (ifra->ifra_dstaddr.sin_addr.s_addr
189 == INADDR_ANY)) {
190 return EDESTADDRREQ;
191 }
192 }
193 if (cmd == SIOCDIFADDR && ia == 0)
194 return (EADDRNOTAVAIL);
195 /* FALLTHROUGH */
196 case SIOCSIFADDR:
197 case SIOCSIFNETMASK:
198 case SIOCSIFDSTADDR:
199 if ((so->so_state & SS_PRIV) == 0)
200 return (EPERM);
201
202 if (ifp == 0)
203 panic("in_control");
204 if (ia == (struct in_ifaddr *)0) {
205 oia = (struct in_ifaddr *)
206 malloc(sizeof *oia, M_IFADDR, M_WAITOK);
207 if (oia == (struct in_ifaddr *)NULL)
208 return (ENOBUFS);
209 bzero((caddr_t)oia, sizeof *oia);
210 ia = in_ifaddr;
211 if (ia) {
212 for ( ; ia->ia_next; ia = ia->ia_next)
213 continue;
214 ia->ia_next = oia;
215 } else
216 in_ifaddr = oia;
217 ia = oia;
218 ifa = ifp->if_addrlist;
219 if (ifa) {
220 for ( ; ifa->ifa_next; ifa = ifa->ifa_next)
221 continue;
222 ifa->ifa_next = (struct ifaddr *) ia;
223 } else
224 ifp->if_addrlist = (struct ifaddr *) ia;
225 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
226 ia->ia_ifa.ifa_dstaddr
227 = (struct sockaddr *)&ia->ia_dstaddr;
228 ia->ia_ifa.ifa_netmask
229 = (struct sockaddr *)&ia->ia_sockmask;
230 ia->ia_sockmask.sin_len = 8;
231 if (ifp->if_flags & IFF_BROADCAST) {
232 ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr);
233 ia->ia_broadaddr.sin_family = AF_INET;
234 }
235 ia->ia_ifp = ifp;
236 if (!(ifp->if_flags & IFF_LOOPBACK))
237 in_interfaces++;
238 }
239 break;
240
241 case SIOCSIFBRDADDR:
242 if ((so->so_state & SS_PRIV) == 0)
243 return (EPERM);
244 /* FALLTHROUGH */
245
246 case SIOCGIFADDR:
247 case SIOCGIFNETMASK:
248 case SIOCGIFDSTADDR:
249 case SIOCGIFBRDADDR:
250 if (ia == (struct in_ifaddr *)0)
251 return (EADDRNOTAVAIL);
252 break;
253 }
254 switch (cmd) {
255
256 case SIOCGIFADDR:
257 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr;
258 break;
259
260 case SIOCGIFBRDADDR:
261 if ((ifp->if_flags & IFF_BROADCAST) == 0)
262 return (EINVAL);
263 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr;
264 break;
265
266 case SIOCGIFDSTADDR:
267 if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
268 return (EINVAL);
269 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr;
270 break;
271
272 case SIOCGIFNETMASK:
273 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask;
274 break;
275
276 case SIOCSIFDSTADDR:
277 if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
278 return (EINVAL);
279 oldaddr = ia->ia_dstaddr;
280 ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr;
281 if (ifp->if_ioctl && (error = (*ifp->if_ioctl)
282 (ifp, SIOCSIFDSTADDR, (caddr_t)ia))) {
283 ia->ia_dstaddr = oldaddr;
284 return (error);
285 }
286 if (ia->ia_flags & IFA_ROUTE) {
287 ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr;
288 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
289 ia->ia_ifa.ifa_dstaddr =
290 (struct sockaddr *)&ia->ia_dstaddr;
291 rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP);
292 }
293 break;
294
295 case SIOCSIFBRDADDR:
296 if ((ifp->if_flags & IFF_BROADCAST) == 0)
297 return (EINVAL);
298 ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr;
299 break;
300
301 case SIOCSIFADDR:
302 return (in_ifinit(ifp, ia,
303 (struct sockaddr_in *) &ifr->ifr_addr, 1));
304
305 case SIOCSIFNETMASK:
306 i = ifra->ifra_addr.sin_addr.s_addr;
307 ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr = i);
308 break;
309
310 case SIOCAIFADDR:
311 maskIsNew = 0;
312 hostIsNew = 1;
313 error = 0;
314 if (ia->ia_addr.sin_family == AF_INET) {
315 if (ifra->ifra_addr.sin_len == 0) {
316 ifra->ifra_addr = ia->ia_addr;
317 hostIsNew = 0;
318 } else if (ifra->ifra_addr.sin_addr.s_addr ==
319 ia->ia_addr.sin_addr.s_addr)
320 hostIsNew = 0;
321 }
322 if (ifra->ifra_mask.sin_len) {
323 in_ifscrub(ifp, ia);
324 ia->ia_sockmask = ifra->ifra_mask;
325 ia->ia_subnetmask =
326 ntohl(ia->ia_sockmask.sin_addr.s_addr);
327 maskIsNew = 1;
328 }
329 if ((ifp->if_flags & IFF_POINTOPOINT) &&
330 (ifra->ifra_dstaddr.sin_family == AF_INET)) {
331 in_ifscrub(ifp, ia);
332 ia->ia_dstaddr = ifra->ifra_dstaddr;
333 maskIsNew = 1; /* We lie; but the effect's the same */
334 }
335 if (ifra->ifra_addr.sin_family == AF_INET &&
336 (hostIsNew || maskIsNew))
337 error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
338 if ((ifp->if_flags & IFF_BROADCAST) &&
339 (ifra->ifra_broadaddr.sin_family == AF_INET))
340 ia->ia_broadaddr = ifra->ifra_broadaddr;
341 return (error);
342
343 case SIOCDIFADDR:
344 mk = malloc(sizeof *mk, M_IPMADDR, M_WAITOK);
345 if (!mk)
346 return ENOBUFS;
347
348 in_ifscrub(ifp, ia);
349 if ((ifa = ifp->if_addrlist) == (struct ifaddr *)ia)
350 ifp->if_addrlist = ifa->ifa_next;
351 else {
352 while (ifa->ifa_next &&
353 (ifa->ifa_next != (struct ifaddr *)ia))
354 ifa = ifa->ifa_next;
355 if (ifa->ifa_next)
356 ifa->ifa_next = ((struct ifaddr *)ia)->ifa_next;
357 else
358 printf("Couldn't unlink inifaddr from ifp\n");
359 }
360 oia = ia;
361 if (oia == (ia = in_ifaddr))
362 in_ifaddr = ia->ia_next;
363 else {
364 while (ia->ia_next && (ia->ia_next != oia))
365 ia = ia->ia_next;
366 if (ia->ia_next)
367 ia->ia_next = oia->ia_next;
368 else
369 printf("Didn't unlink inifadr from list\n");
370 }
371
372 if (!oia->ia_multiaddrs.lh_first) {
373 IFAFREE(&oia->ia_ifa);
374 FREE(mk, M_IPMADDR);
375 break;
376 }
377
378 /*
379 * Multicast address kludge:
380 * If there were any multicast addresses attached to this
381 * interface address, either move them to another address
382 * on this interface, or save them until such time as this
383 * interface is reconfigured for IP.
384 */
385 IFP_TO_IA(oia->ia_ifp, ia);
386 if (ia) { /* there is another address */
387 struct in_multi *inm;
388 for(inm = oia->ia_multiaddrs.lh_first; inm;
389 inm = inm->inm_entry.le_next) {
390 IFAFREE(&inm->inm_ia->ia_ifa);
391 ia->ia_ifa.ifa_refcnt++;
392 inm->inm_ia = ia;
393 LIST_INSERT_HEAD(&ia->ia_multiaddrs, inm,
394 inm_entry);
395 }
396 FREE(mk, M_IPMADDR);
397 } else { /* last address on this if deleted, save */
398 struct in_multi *inm;
399
400 LIST_INIT(&mk->mk_head);
401 mk->mk_ifp = ifp;
402
403 for(inm = oia->ia_multiaddrs.lh_first; inm;
404 inm = inm->inm_entry.le_next) {
405 LIST_INSERT_HEAD(&mk->mk_head, inm, inm_entry);
406 }
407
408 if (mk->mk_head.lh_first) {
409 LIST_INSERT_HEAD(&in_mk, mk, mk_entry);
410 } else {
411 FREE(mk, M_IPMADDR);
412 }
413 }
414
415 IFAFREE((&oia->ia_ifa));
416 break;
417
418 default:
419 if (ifp == 0 || ifp->if_ioctl == 0)
420 return (EOPNOTSUPP);
421 return ((*ifp->if_ioctl)(ifp, cmd, data));
422 }
423 return (0);
424}
425
426/*
427 * Delete any existing route for an interface.
428 */
429static void
430in_ifscrub(ifp, ia)
431 register struct ifnet *ifp;
432 register struct in_ifaddr *ia;
433{
434
435 if ((ia->ia_flags & IFA_ROUTE) == 0)
436 return;
437 if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT))
438 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
439 else
440 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0);
441 ia->ia_flags &= ~IFA_ROUTE;
442}
443
444/*
445 * Initialize an interface's internet address
446 * and routing table entry.
447 */
448static int
449in_ifinit(ifp, ia, sin, scrub)
450 register struct ifnet *ifp;
451 register struct in_ifaddr *ia;
452 struct sockaddr_in *sin;
453 int scrub;
454{
455 register u_long i = ntohl(sin->sin_addr.s_addr);
456 struct sockaddr_in oldaddr;
457 int s = splimp(), flags = RTF_UP, error;
458 struct multi_kludge *mk;
459
460 oldaddr = ia->ia_addr;
461 ia->ia_addr = *sin;
462 /*
463 * Give the interface a chance to initialize
464 * if this is its first address,
465 * and to validate the address if necessary.
466 */
467 if (ifp->if_ioctl &&
468 (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia))) {
469 splx(s);
470 ia->ia_addr = oldaddr;
471 return (error);
472 }
473 splx(s);
474 if (scrub) {
475 ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr;
476 in_ifscrub(ifp, ia);
477 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
478 }
479 if (IN_CLASSA(i))
480 ia->ia_netmask = IN_CLASSA_NET;
481 else if (IN_CLASSB(i))
482 ia->ia_netmask = IN_CLASSB_NET;
483 else
484 ia->ia_netmask = IN_CLASSC_NET;
485 /*
486 * The subnet mask usually includes at least the standard network part,
487 * but may may be smaller in the case of supernetting.
488 * If it is set, we believe it.
489 */
490 if (ia->ia_subnetmask == 0) {
491 ia->ia_subnetmask = ia->ia_netmask;
492 ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
493 } else
494 ia->ia_netmask &= ia->ia_subnetmask;
495 ia->ia_net = i & ia->ia_netmask;
496 ia->ia_subnet = i & ia->ia_subnetmask;
497 in_socktrim(&ia->ia_sockmask);
498 /*
499 * Add route for the network.
500 */
501 ia->ia_ifa.ifa_metric = ifp->if_metric;
502 if (ifp->if_flags & IFF_BROADCAST) {
503 ia->ia_broadaddr.sin_addr.s_addr =
504 htonl(ia->ia_subnet | ~ia->ia_subnetmask);
505 ia->ia_netbroadcast.s_addr =
506 htonl(ia->ia_net | ~ ia->ia_netmask);
507 } else if (ifp->if_flags & IFF_LOOPBACK) {
508 ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr;
509 flags |= RTF_HOST;
510 } else if (ifp->if_flags & IFF_POINTOPOINT) {
511 if (ia->ia_dstaddr.sin_family != AF_INET)
512 return (0);
513 flags |= RTF_HOST;
514 }
515 if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD, flags)) == 0)
516 ia->ia_flags |= IFA_ROUTE;
517
518 LIST_INIT(&ia->ia_multiaddrs);
519 /*
520 * If the interface supports multicast, join the "all hosts"
521 * multicast group on that interface.
522 */
523 if (ifp->if_flags & IFF_MULTICAST) {
524 struct in_addr addr;
525
526 /*
527 * Continuation of multicast address hack:
528 * If there was a multicast group list previously saved
529 * for this interface, then we re-attach it to the first
530 * address configured on the i/f.
531 */
532 for(mk = in_mk.lh_first; mk; mk = mk->mk_entry.le_next) {
533 if(mk->mk_ifp == ifp) {
534 struct in_multi *inm;
535
536 for(inm = mk->mk_head.lh_first; inm;
537 inm = inm->inm_entry.le_next) {
538 IFAFREE(&inm->inm_ia->ia_ifa);
539 ia->ia_ifa.ifa_refcnt++;
540 inm->inm_ia = ia;
541 LIST_INSERT_HEAD(&ia->ia_multiaddrs,
542 inm, inm_entry);
543 }
544 LIST_REMOVE(mk, mk_entry);
545 free(mk, M_IPMADDR);
546 break;
547 }
548 }
549
550 addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
551 in_addmulti(&addr, ifp);
552 }
553 return (error);
554}
555
556
557/*
558 * Return 1 if the address might be a local broadcast address.
559 */
560int
561in_broadcast(in, ifp)
562 struct in_addr in;
563 struct ifnet *ifp;
564{
565 register struct ifaddr *ifa;
566 u_long t;
567
568 if (in.s_addr == INADDR_BROADCAST ||
569 in.s_addr == INADDR_ANY)
570 return 1;
571 if ((ifp->if_flags & IFF_BROADCAST) == 0)
572 return 0;
573 t = ntohl(in.s_addr);
574 /*
575 * Look through the list of addresses for a match
576 * with a broadcast address.
577 */
578#define ia ((struct in_ifaddr *)ifa)
579 for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next)
580 if (ifa->ifa_addr->sa_family == AF_INET &&
581 (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
582 in.s_addr == ia->ia_netbroadcast.s_addr ||
583 /*
584 * Check for old-style (host 0) broadcast.
585 */
586 t == ia->ia_subnet || t == ia->ia_net) &&
587 /*
588 * Check for an all one subnetmask. These
589 * only exist when an interface gets a secondary
590 * address.
591 */
592 ia->ia_subnetmask != (u_long)0xffffffff)
593 return 1;
594 return (0);
595#undef ia
596}
597/*
598 * Add an address to the list of IP multicast addresses for a given interface.
599 */
600struct in_multi *
601in_addmulti(ap, ifp)
602 register struct in_addr *ap;
603 register struct ifnet *ifp;
604{
605 register struct in_multi *inm;
606 struct ifreq ifr;
607 struct in_ifaddr *ia;
608 int s = splnet();
609
610 /*
611 * See if address already in list.
612 */
613 IN_LOOKUP_MULTI(*ap, ifp, inm);
614 if (inm != NULL) {
615 /*
616 * Found it; just increment the reference count.
617 */
618 ++inm->inm_refcount;
619 }
620 else {
621 /*
622 * New address; allocate a new multicast record
623 * and link it into the interface's multicast list.
624 */
625 inm = (struct in_multi *)malloc(sizeof(*inm),
626 M_IPMADDR, M_NOWAIT);
627 if (inm == NULL) {
628 splx(s);
629 return (NULL);
630 }
631 inm->inm_addr = *ap;
632 inm->inm_ifp = ifp;
633 inm->inm_refcount = 1;
634 IFP_TO_IA(ifp, ia);
635 if (ia == NULL) {
636 free(inm, M_IPMADDR);
637 splx(s);
638 return (NULL);
639 }
640 inm->inm_ia = ia;
641 ia->ia_ifa.ifa_refcnt++; /* gain a reference */
642 LIST_INSERT_HEAD(&ia->ia_multiaddrs, inm, inm_entry);
643
644 /*
645 * Ask the network driver to update its multicast reception
646 * filter appropriately for the new address.
647 */
648 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_family = AF_INET;
649 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr = *ap;
650 if ((ifp->if_ioctl == NULL) ||
651 (*ifp->if_ioctl)(ifp, SIOCADDMULTI,(caddr_t)&ifr) != 0) {
652 LIST_REMOVE(inm, inm_entry);
653 IFAFREE(&ia->ia_ifa); /* release reference */
654 free(inm, M_IPMADDR);
655 splx(s);
656 return (NULL);
657 }
658 /*
659 * Let IGMP know that we have joined a new IP multicast group.
660 */
661 igmp_joingroup(inm);
662 }
663 splx(s);
664 return (inm);
665}
666
667/*
668 * Delete a multicast address record.
669 */
670void
671in_delmulti(inm)
672 register struct in_multi *inm;
673{
674 struct ifreq ifr;
675 int s = splnet();
676
677 if (--inm->inm_refcount == 0) {
678 /*
679 * No remaining claims to this record; let IGMP know that
680 * we are leaving the multicast group.
681 */
682 igmp_leavegroup(inm);
683 /*
684 * Unlink from list.
685 */
686 LIST_REMOVE(inm, inm_entry);
687 IFAFREE(&inm->inm_ia->ia_ifa); /* release reference */
688
689 /*
690 * Notify the network driver to update its multicast reception
691 * filter.
692 */
693 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_family = AF_INET;
694 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_addr =
695 inm->inm_addr;
696 (*inm->inm_ifp->if_ioctl)(inm->inm_ifp, SIOCDELMULTI,
697 (caddr_t)&ifr);
698 free(inm, M_IPMADDR);
699 }
700 splx(s);
701}
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