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 1.20 1995/12/09 20:43:52 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 #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 */ 62 static LIST_HEAD(, multi_kludge) in_mk; /* XXX BSS initialization */ 63 64 struct multi_kludge { 65 LIST_ENTRY(multi_kludge) mk_entry; 66 struct ifnet *mk_ifp; 67 struct in_multihead mk_head; 68 }; 69 70 static void in_socktrim __P((struct sockaddr_in *)); 71 static int in_ifinit __P((struct ifnet *, 72 struct in_ifaddr *, struct sockaddr_in *, int)); 73 static void in_ifscrub __P((struct ifnet *, struct in_ifaddr *)); 74 75 static int subnetsarelocal = 1; 76 SYSCTL_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 */ 84 int 85 in_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 */ 108 int 109 in_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 */ 128 static void 129 in_socktrim(ap) 130 struct 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 } 142 143 static 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 */ 150 int 151 in_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 */ 429 static void 430 in_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 */ 448 static int 449 in_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 */ 560 int 561 in_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 */ 600 struct in_multi * 601 in_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 */ 670 void 671 in_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 } 702