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 * $Id: in.c,v 1.18 1995/11/14 20:33:56 phk Exp $ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/ioctl.h> 40 #include <sys/errno.h> 41 #include <sys/malloc.h> 42 #include <sys/socket.h> 43 #include <sys/socketvar.h> 44 #include <sys/queue.h> 45 46 #include <net/if.h> 47 #include <net/route.h> 48 49 #include <netinet/in_systm.h> 50 #include <netinet/in.h> 51 #include <netinet/in_var.h> 52 #include <netinet/if_ether.h> 53 54 #include <netinet/igmp_var.h> 55 56 /* 57 * This structure is used to keep track of in_multi chains which belong to 58 * deleted interface addresses. 59 */ 60 static LIST_HEAD(, multi_kludge) in_mk; /* XXX BSS initialization */ 61 62 struct multi_kludge { 63 LIST_ENTRY(multi_kludge) mk_entry; 64 struct ifnet *mk_ifp; 65 struct in_multihead mk_head; 66 }; 67 68 static void in_socktrim __P((struct sockaddr_in *)); 69 static int in_ifinit __P((struct ifnet *, 70 struct in_ifaddr *, struct sockaddr_in *, int)); 71 static void in_ifscrub __P((struct ifnet *, struct in_ifaddr *)); 72 73 #ifndef SUBNETSARELOCAL 74 #define SUBNETSARELOCAL 1 75 #endif 76 int subnetsarelocal = SUBNETSARELOCAL; 77 /* 78 * Return 1 if an internet address is for a ``local'' host 79 * (one to which we have a connection). If subnetsarelocal 80 * is true, this includes other subnets of the local net. 81 * Otherwise, it includes only the directly-connected (sub)nets. 82 */ 83 int 84 in_localaddr(in) 85 struct in_addr in; 86 { 87 register u_long i = ntohl(in.s_addr); 88 register struct in_ifaddr *ia; 89 90 if (subnetsarelocal) { 91 for (ia = in_ifaddr; ia; ia = ia->ia_next) 92 if ((i & ia->ia_netmask) == ia->ia_net) 93 return (1); 94 } else { 95 for (ia = in_ifaddr; ia; ia = ia->ia_next) 96 if ((i & ia->ia_subnetmask) == ia->ia_subnet) 97 return (1); 98 } 99 return (0); 100 } 101 102 /* 103 * Determine whether an IP address is in a reserved set of addresses 104 * that may not be forwarded, or whether datagrams to that destination 105 * may be forwarded. 106 */ 107 int 108 in_canforward(in) 109 struct in_addr in; 110 { 111 register u_long i = ntohl(in.s_addr); 112 register 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(ap) 129 struct sockaddr_in *ap; 130 { 131 register char *cplim = (char *) &ap->sin_addr; 132 register char *cp = (char *) (&ap->sin_addr + 1); 133 134 ap->sin_len = 0; 135 while (--cp >= cplim) 136 if (*cp) { 137 (ap)->sin_len = cp - (char *) (ap) + 1; 138 break; 139 } 140 } 141 142 int in_interfaces; /* number of external internet interfaces */ 143 144 /* 145 * Generic internet control operations (ioctl's). 146 * Ifp is 0 if not an interface-specific ioctl. 147 */ 148 /* ARGSUSED */ 149 int 150 in_control(so, cmd, data, ifp) 151 struct socket *so; 152 u_long cmd; 153 caddr_t data; 154 register struct ifnet *ifp; 155 { 156 register struct ifreq *ifr = (struct ifreq *)data; 157 register struct in_ifaddr *ia = 0; 158 register struct ifaddr *ifa; 159 struct in_ifaddr *oia; 160 struct in_aliasreq *ifra = (struct in_aliasreq *)data; 161 struct sockaddr_in oldaddr; 162 int error, hostIsNew, maskIsNew; 163 u_long i; 164 struct multi_kludge *mk; 165 166 /* 167 * Find address for this interface, if it exists. 168 */ 169 if (ifp) 170 for (ia = in_ifaddr; ia; ia = ia->ia_next) 171 if (ia->ia_ifp == ifp) 172 break; 173 174 switch (cmd) { 175 176 case SIOCAIFADDR: 177 case SIOCDIFADDR: 178 if (ifra->ifra_addr.sin_family == AF_INET) { 179 for (oia = ia; ia; ia = ia->ia_next) { 180 if (ia->ia_ifp == ifp && 181 ia->ia_addr.sin_addr.s_addr == 182 ifra->ifra_addr.sin_addr.s_addr) 183 break; 184 } 185 if ((ifp->if_flags & IFF_POINTOPOINT) 186 && (cmd == SIOCAIFADDR) 187 && (ifra->ifra_dstaddr.sin_addr.s_addr 188 == INADDR_ANY)) { 189 return EDESTADDRREQ; 190 } 191 } 192 if (cmd == SIOCDIFADDR && ia == 0) 193 return (EADDRNOTAVAIL); 194 /* FALLTHROUGH */ 195 case SIOCSIFADDR: 196 case SIOCSIFNETMASK: 197 case SIOCSIFDSTADDR: 198 if ((so->so_state & SS_PRIV) == 0) 199 return (EPERM); 200 201 if (ifp == 0) 202 panic("in_control"); 203 if (ia == (struct in_ifaddr *)0) { 204 oia = (struct in_ifaddr *) 205 malloc(sizeof *oia, M_IFADDR, M_WAITOK); 206 if (oia == (struct in_ifaddr *)NULL) 207 return (ENOBUFS); 208 bzero((caddr_t)oia, sizeof *oia); 209 ia = in_ifaddr; 210 if (ia) { 211 for ( ; ia->ia_next; ia = ia->ia_next) 212 continue; 213 ia->ia_next = oia; 214 } else 215 in_ifaddr = oia; 216 ia = oia; 217 ifa = ifp->if_addrlist; 218 if (ifa) { 219 for ( ; ifa->ifa_next; ifa = ifa->ifa_next) 220 continue; 221 ifa->ifa_next = (struct ifaddr *) ia; 222 } else 223 ifp->if_addrlist = (struct ifaddr *) ia; 224 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr; 225 ia->ia_ifa.ifa_dstaddr 226 = (struct sockaddr *)&ia->ia_dstaddr; 227 ia->ia_ifa.ifa_netmask 228 = (struct sockaddr *)&ia->ia_sockmask; 229 ia->ia_sockmask.sin_len = 8; 230 if (ifp->if_flags & IFF_BROADCAST) { 231 ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr); 232 ia->ia_broadaddr.sin_family = AF_INET; 233 } 234 ia->ia_ifp = ifp; 235 if (!(ifp->if_flags & IFF_LOOPBACK)) 236 in_interfaces++; 237 } 238 break; 239 240 case SIOCSIFBRDADDR: 241 if ((so->so_state & SS_PRIV) == 0) 242 return (EPERM); 243 /* FALLTHROUGH */ 244 245 case SIOCGIFADDR: 246 case SIOCGIFNETMASK: 247 case SIOCGIFDSTADDR: 248 case SIOCGIFBRDADDR: 249 if (ia == (struct in_ifaddr *)0) 250 return (EADDRNOTAVAIL); 251 break; 252 } 253 switch (cmd) { 254 255 case SIOCGIFADDR: 256 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr; 257 break; 258 259 case SIOCGIFBRDADDR: 260 if ((ifp->if_flags & IFF_BROADCAST) == 0) 261 return (EINVAL); 262 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr; 263 break; 264 265 case SIOCGIFDSTADDR: 266 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 267 return (EINVAL); 268 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr; 269 break; 270 271 case SIOCGIFNETMASK: 272 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask; 273 break; 274 275 case SIOCSIFDSTADDR: 276 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 277 return (EINVAL); 278 oldaddr = ia->ia_dstaddr; 279 ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr; 280 if (ifp->if_ioctl && (error = (*ifp->if_ioctl) 281 (ifp, SIOCSIFDSTADDR, (caddr_t)ia))) { 282 ia->ia_dstaddr = oldaddr; 283 return (error); 284 } 285 if (ia->ia_flags & IFA_ROUTE) { 286 ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr; 287 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); 288 ia->ia_ifa.ifa_dstaddr = 289 (struct sockaddr *)&ia->ia_dstaddr; 290 rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP); 291 } 292 break; 293 294 case SIOCSIFBRDADDR: 295 if ((ifp->if_flags & IFF_BROADCAST) == 0) 296 return (EINVAL); 297 ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr; 298 break; 299 300 case SIOCSIFADDR: 301 return (in_ifinit(ifp, ia, 302 (struct sockaddr_in *) &ifr->ifr_addr, 1)); 303 304 case SIOCSIFNETMASK: 305 i = ifra->ifra_addr.sin_addr.s_addr; 306 ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr = i); 307 break; 308 309 case SIOCAIFADDR: 310 maskIsNew = 0; 311 hostIsNew = 1; 312 error = 0; 313 if (ia->ia_addr.sin_family == AF_INET) { 314 if (ifra->ifra_addr.sin_len == 0) { 315 ifra->ifra_addr = ia->ia_addr; 316 hostIsNew = 0; 317 } else if (ifra->ifra_addr.sin_addr.s_addr == 318 ia->ia_addr.sin_addr.s_addr) 319 hostIsNew = 0; 320 } 321 if (ifra->ifra_mask.sin_len) { 322 in_ifscrub(ifp, ia); 323 ia->ia_sockmask = ifra->ifra_mask; 324 ia->ia_subnetmask = 325 ntohl(ia->ia_sockmask.sin_addr.s_addr); 326 maskIsNew = 1; 327 } 328 if ((ifp->if_flags & IFF_POINTOPOINT) && 329 (ifra->ifra_dstaddr.sin_family == AF_INET)) { 330 in_ifscrub(ifp, ia); 331 ia->ia_dstaddr = ifra->ifra_dstaddr; 332 maskIsNew = 1; /* We lie; but the effect's the same */ 333 } 334 if (ifra->ifra_addr.sin_family == AF_INET && 335 (hostIsNew || maskIsNew)) 336 error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0); 337 if ((ifp->if_flags & IFF_BROADCAST) && 338 (ifra->ifra_broadaddr.sin_family == AF_INET)) 339 ia->ia_broadaddr = ifra->ifra_broadaddr; 340 return (error); 341 342 case SIOCDIFADDR: 343 mk = malloc(sizeof *mk, M_IPMADDR, M_WAITOK); 344 if (!mk) 345 return ENOBUFS; 346 347 in_ifscrub(ifp, ia); 348 if ((ifa = ifp->if_addrlist) == (struct ifaddr *)ia) 349 ifp->if_addrlist = ifa->ifa_next; 350 else { 351 while (ifa->ifa_next && 352 (ifa->ifa_next != (struct ifaddr *)ia)) 353 ifa = ifa->ifa_next; 354 if (ifa->ifa_next) 355 ifa->ifa_next = ((struct ifaddr *)ia)->ifa_next; 356 else 357 printf("Couldn't unlink inifaddr from ifp\n"); 358 } 359 oia = ia; 360 if (oia == (ia = in_ifaddr)) 361 in_ifaddr = ia->ia_next; 362 else { 363 while (ia->ia_next && (ia->ia_next != oia)) 364 ia = ia->ia_next; 365 if (ia->ia_next) 366 ia->ia_next = oia->ia_next; 367 else 368 printf("Didn't unlink inifadr from list\n"); 369 } 370 371 if (!oia->ia_multiaddrs.lh_first) { 372 IFAFREE(&oia->ia_ifa); 373 FREE(mk, M_IPMADDR); 374 break; 375 } 376 377 /* 378 * Multicast address kludge: 379 * If there were any multicast addresses attached to this 380 * interface address, either move them to another address 381 * on this interface, or save them until such time as this 382 * interface is reconfigured for IP. 383 */ 384 IFP_TO_IA(oia->ia_ifp, ia); 385 if (ia) { /* there is another address */ 386 struct in_multi *inm; 387 for(inm = oia->ia_multiaddrs.lh_first; inm; 388 inm = inm->inm_entry.le_next) { 389 IFAFREE(&inm->inm_ia->ia_ifa); 390 ia->ia_ifa.ifa_refcnt++; 391 inm->inm_ia = ia; 392 LIST_INSERT_HEAD(&ia->ia_multiaddrs, inm, 393 inm_entry); 394 } 395 FREE(mk, M_IPMADDR); 396 } else { /* last address on this if deleted, save */ 397 struct in_multi *inm; 398 399 LIST_INIT(&mk->mk_head); 400 mk->mk_ifp = ifp; 401 402 for(inm = oia->ia_multiaddrs.lh_first; inm; 403 inm = inm->inm_entry.le_next) { 404 LIST_INSERT_HEAD(&mk->mk_head, inm, inm_entry); 405 } 406 407 if (mk->mk_head.lh_first) { 408 LIST_INSERT_HEAD(&in_mk, mk, mk_entry); 409 } else { 410 FREE(mk, M_IPMADDR); 411 } 412 } 413 414 IFAFREE((&oia->ia_ifa)); 415 break; 416 417 default: 418 if (ifp == 0 || ifp->if_ioctl == 0) 419 return (EOPNOTSUPP); 420 return ((*ifp->if_ioctl)(ifp, cmd, data)); 421 } 422 return (0); 423 } 424 425 /* 426 * Delete any existing route for an interface. 427 */ 428 static void 429 in_ifscrub(ifp, ia) 430 register struct ifnet *ifp; 431 register struct in_ifaddr *ia; 432 { 433 434 if ((ia->ia_flags & IFA_ROUTE) == 0) 435 return; 436 if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT)) 437 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); 438 else 439 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0); 440 ia->ia_flags &= ~IFA_ROUTE; 441 } 442 443 /* 444 * Initialize an interface's internet address 445 * and routing table entry. 446 */ 447 static int 448 in_ifinit(ifp, ia, sin, scrub) 449 register struct ifnet *ifp; 450 register struct in_ifaddr *ia; 451 struct sockaddr_in *sin; 452 int scrub; 453 { 454 register u_long i = ntohl(sin->sin_addr.s_addr); 455 struct sockaddr_in oldaddr; 456 int s = splimp(), flags = RTF_UP, error; 457 struct multi_kludge *mk; 458 459 oldaddr = ia->ia_addr; 460 ia->ia_addr = *sin; 461 /* 462 * Give the interface a chance to initialize 463 * if this is its first address, 464 * and to validate the address if necessary. 465 */ 466 if (ifp->if_ioctl && 467 (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia))) { 468 splx(s); 469 ia->ia_addr = oldaddr; 470 return (error); 471 } 472 splx(s); 473 if (scrub) { 474 ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr; 475 in_ifscrub(ifp, ia); 476 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr; 477 } 478 if (IN_CLASSA(i)) 479 ia->ia_netmask = IN_CLASSA_NET; 480 else if (IN_CLASSB(i)) 481 ia->ia_netmask = IN_CLASSB_NET; 482 else 483 ia->ia_netmask = IN_CLASSC_NET; 484 /* 485 * The subnet mask usually includes at least the standard network part, 486 * but may may be smaller in the case of supernetting. 487 * If it is set, we believe it. 488 */ 489 if (ia->ia_subnetmask == 0) { 490 ia->ia_subnetmask = ia->ia_netmask; 491 ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask); 492 } else 493 ia->ia_netmask &= ia->ia_subnetmask; 494 ia->ia_net = i & ia->ia_netmask; 495 ia->ia_subnet = i & ia->ia_subnetmask; 496 in_socktrim(&ia->ia_sockmask); 497 /* 498 * Add route for the network. 499 */ 500 ia->ia_ifa.ifa_metric = ifp->if_metric; 501 if (ifp->if_flags & IFF_BROADCAST) { 502 ia->ia_broadaddr.sin_addr.s_addr = 503 htonl(ia->ia_subnet | ~ia->ia_subnetmask); 504 ia->ia_netbroadcast.s_addr = 505 htonl(ia->ia_net | ~ ia->ia_netmask); 506 } else if (ifp->if_flags & IFF_LOOPBACK) { 507 ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr; 508 flags |= RTF_HOST; 509 } else if (ifp->if_flags & IFF_POINTOPOINT) { 510 if (ia->ia_dstaddr.sin_family != AF_INET) 511 return (0); 512 flags |= RTF_HOST; 513 } 514 if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD, flags)) == 0) 515 ia->ia_flags |= IFA_ROUTE; 516 517 LIST_INIT(&ia->ia_multiaddrs); 518 /* 519 * If the interface supports multicast, join the "all hosts" 520 * multicast group on that interface. 521 */ 522 if (ifp->if_flags & IFF_MULTICAST) { 523 struct in_addr addr; 524 525 /* 526 * Continuation of multicast address hack: 527 * If there was a multicast group list previously saved 528 * for this interface, then we re-attach it to the first 529 * address configured on the i/f. 530 */ 531 for(mk = in_mk.lh_first; mk; mk = mk->mk_entry.le_next) { 532 if(mk->mk_ifp == ifp) { 533 struct in_multi *inm; 534 535 for(inm = mk->mk_head.lh_first; inm; 536 inm = inm->inm_entry.le_next) { 537 IFAFREE(&inm->inm_ia->ia_ifa); 538 ia->ia_ifa.ifa_refcnt++; 539 inm->inm_ia = ia; 540 LIST_INSERT_HEAD(&ia->ia_multiaddrs, 541 inm, inm_entry); 542 } 543 LIST_REMOVE(mk, mk_entry); 544 free(mk, M_IPMADDR); 545 break; 546 } 547 } 548 549 addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP); 550 in_addmulti(&addr, ifp); 551 } 552 return (error); 553 } 554 555 556 /* 557 * Return 1 if the address might be a local broadcast address. 558 */ 559 int 560 in_broadcast(in, ifp) 561 struct in_addr in; 562 struct ifnet *ifp; 563 { 564 register struct ifaddr *ifa; 565 u_long t; 566 567 if (in.s_addr == INADDR_BROADCAST || 568 in.s_addr == INADDR_ANY) 569 return 1; 570 if ((ifp->if_flags & IFF_BROADCAST) == 0) 571 return 0; 572 t = ntohl(in.s_addr); 573 /* 574 * Look through the list of addresses for a match 575 * with a broadcast address. 576 */ 577 #define ia ((struct in_ifaddr *)ifa) 578 for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next) 579 if (ifa->ifa_addr->sa_family == AF_INET && 580 (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr || 581 in.s_addr == ia->ia_netbroadcast.s_addr || 582 /* 583 * Check for old-style (host 0) broadcast. 584 */ 585 t == ia->ia_subnet || t == ia->ia_net)) 586 return 1; 587 return (0); 588 #undef ia 589 } 590 /* 591 * Add an address to the list of IP multicast addresses for a given interface. 592 */ 593 struct in_multi * 594 in_addmulti(ap, ifp) 595 register struct in_addr *ap; 596 register struct ifnet *ifp; 597 { 598 register struct in_multi *inm; 599 struct ifreq ifr; 600 struct in_ifaddr *ia; 601 int s = splnet(); 602 603 /* 604 * See if address already in list. 605 */ 606 IN_LOOKUP_MULTI(*ap, ifp, inm); 607 if (inm != NULL) { 608 /* 609 * Found it; just increment the reference count. 610 */ 611 ++inm->inm_refcount; 612 } 613 else { 614 /* 615 * New address; allocate a new multicast record 616 * and link it into the interface's multicast list. 617 */ 618 inm = (struct in_multi *)malloc(sizeof(*inm), 619 M_IPMADDR, M_NOWAIT); 620 if (inm == NULL) { 621 splx(s); 622 return (NULL); 623 } 624 inm->inm_addr = *ap; 625 inm->inm_ifp = ifp; 626 inm->inm_refcount = 1; 627 IFP_TO_IA(ifp, ia); 628 if (ia == NULL) { 629 free(inm, M_IPMADDR); 630 splx(s); 631 return (NULL); 632 } 633 inm->inm_ia = ia; 634 ia->ia_ifa.ifa_refcnt++; /* gain a reference */ 635 LIST_INSERT_HEAD(&ia->ia_multiaddrs, inm, inm_entry); 636 637 /* 638 * Ask the network driver to update its multicast reception 639 * filter appropriately for the new address. 640 */ 641 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_family = AF_INET; 642 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr = *ap; 643 if ((ifp->if_ioctl == NULL) || 644 (*ifp->if_ioctl)(ifp, SIOCADDMULTI,(caddr_t)&ifr) != 0) { 645 LIST_REMOVE(inm, inm_entry); 646 IFAFREE(&ia->ia_ifa); /* release reference */ 647 free(inm, M_IPMADDR); 648 splx(s); 649 return (NULL); 650 } 651 /* 652 * Let IGMP know that we have joined a new IP multicast group. 653 */ 654 igmp_joingroup(inm); 655 } 656 splx(s); 657 return (inm); 658 } 659 660 /* 661 * Delete a multicast address record. 662 */ 663 void 664 in_delmulti(inm) 665 register struct in_multi *inm; 666 { 667 struct ifreq ifr; 668 int s = splnet(); 669 670 if (--inm->inm_refcount == 0) { 671 /* 672 * No remaining claims to this record; let IGMP know that 673 * we are leaving the multicast group. 674 */ 675 igmp_leavegroup(inm); 676 /* 677 * Unlink from list. 678 */ 679 LIST_REMOVE(inm, inm_entry); 680 IFAFREE(&inm->inm_ia->ia_ifa); /* release reference */ 681 682 /* 683 * Notify the network driver to update its multicast reception 684 * filter. 685 */ 686 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_family = AF_INET; 687 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_addr = 688 inm->inm_addr; 689 (*inm->inm_ifp->if_ioctl)(inm->inm_ifp, SIOCDELMULTI, 690 (caddr_t)&ifr); 691 free(inm, M_IPMADDR); 692 } 693 splx(s); 694 } 695