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 1.26 1996/12/13 21:28:52 wollman Exp $ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/queue.h> 39 #include <sys/systm.h> 40 #include <sys/ioctl.h> 41 #include <sys/errno.h> 42 #include <sys/malloc.h> 43 #include <sys/socket.h> 44 #include <sys/socketvar.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 = 0; 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_ifaddrhead.tqh_first; ia; 93 ia = ia->ia_link.tqe_next) 94 if ((i & ia->ia_netmask) == ia->ia_net) 95 return (1); 96 } else { 97 for (ia = in_ifaddrhead.tqh_first; ia; 98 ia = ia->ia_link.tqe_next) 99 if ((i & ia->ia_subnetmask) == ia->ia_subnet) 100 return (1); 101 } 102 return (0); 103 } 104 105 /* 106 * Determine whether an IP address is in a reserved set of addresses 107 * that may not be forwarded, or whether datagrams to that destination 108 * may be forwarded. 109 */ 110 int 111 in_canforward(in) 112 struct in_addr in; 113 { 114 register u_long i = ntohl(in.s_addr); 115 register u_long net; 116 117 if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i)) 118 return (0); 119 if (IN_CLASSA(i)) { 120 net = i & IN_CLASSA_NET; 121 if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT)) 122 return (0); 123 } 124 return (1); 125 } 126 127 /* 128 * Trim a mask in a sockaddr 129 */ 130 static void 131 in_socktrim(ap) 132 struct sockaddr_in *ap; 133 { 134 register char *cplim = (char *) &ap->sin_addr; 135 register char *cp = (char *) (&ap->sin_addr + 1); 136 137 ap->sin_len = 0; 138 while (--cp >= cplim) 139 if (*cp) { 140 (ap)->sin_len = cp - (char *) (ap) + 1; 141 break; 142 } 143 } 144 145 static int in_interfaces; /* number of external internet interfaces */ 146 147 /* 148 * Generic internet control operations (ioctl's). 149 * Ifp is 0 if not an interface-specific ioctl. 150 */ 151 /* ARGSUSED */ 152 int 153 in_control(so, cmd, data, ifp) 154 struct socket *so; 155 u_long cmd; 156 caddr_t data; 157 register struct ifnet *ifp; 158 { 159 register struct ifreq *ifr = (struct ifreq *)data; 160 register struct in_ifaddr *ia = 0, *iap; 161 register struct ifaddr *ifa; 162 struct in_ifaddr *oia; 163 struct in_aliasreq *ifra = (struct in_aliasreq *)data; 164 struct sockaddr_in oldaddr; 165 int error, hostIsNew, maskIsNew, s; 166 u_long i; 167 struct multi_kludge *mk; 168 169 /* 170 * Find address for this interface, if it exists. 171 * 172 * If an alias address was specified, find that one instead of 173 * the first one on the interface. 174 */ 175 if (ifp) 176 for (iap = in_ifaddrhead.tqh_first; iap; 177 iap = iap->ia_link.tqe_next) 178 if (iap->ia_ifp == ifp) { 179 if (((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr.s_addr == 180 iap->ia_addr.sin_addr.s_addr) { 181 ia = iap; 182 break; 183 } else if (ia == NULL) { 184 ia = iap; 185 if (ifr->ifr_addr.sa_family != AF_INET) 186 break; 187 } 188 } 189 190 switch (cmd) { 191 192 case SIOCAIFADDR: 193 case SIOCDIFADDR: 194 if (ifra->ifra_addr.sin_family == AF_INET) { 195 for (oia = ia; ia; ia = ia->ia_link.tqe_next) { 196 if (ia->ia_ifp == ifp && 197 ia->ia_addr.sin_addr.s_addr == 198 ifra->ifra_addr.sin_addr.s_addr) 199 break; 200 } 201 if ((ifp->if_flags & IFF_POINTOPOINT) 202 && (cmd == SIOCAIFADDR) 203 && (ifra->ifra_dstaddr.sin_addr.s_addr 204 == INADDR_ANY)) { 205 return EDESTADDRREQ; 206 } 207 } 208 if (cmd == SIOCDIFADDR && ia == 0) 209 return (EADDRNOTAVAIL); 210 /* FALLTHROUGH */ 211 case SIOCSIFADDR: 212 case SIOCSIFNETMASK: 213 case SIOCSIFDSTADDR: 214 if ((so->so_state & SS_PRIV) == 0) 215 return (EPERM); 216 217 if (ifp == 0) 218 panic("in_control"); 219 if (ia == (struct in_ifaddr *)0) { 220 ia = (struct in_ifaddr *) 221 malloc(sizeof *ia, M_IFADDR, M_WAITOK); 222 if (ia == (struct in_ifaddr *)NULL) 223 return (ENOBUFS); 224 bzero((caddr_t)ia, sizeof *ia); 225 /* 226 * Protect from ipintr() traversing address list 227 * while we're modifying it. 228 */ 229 s = splnet(); 230 231 TAILQ_INSERT_TAIL(&in_ifaddrhead, ia, ia_link); 232 ifa = &ia->ia_ifa; 233 TAILQ_INSERT_TAIL(&ifp->if_addrhead, ifa, ifa_link); 234 235 ifa->ifa_addr = (struct sockaddr *)&ia->ia_addr; 236 ifa->ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr; 237 ifa->ifa_netmask = (struct sockaddr *)&ia->ia_sockmask; 238 ia->ia_sockmask.sin_len = 8; 239 if (ifp->if_flags & IFF_BROADCAST) { 240 ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr); 241 ia->ia_broadaddr.sin_family = AF_INET; 242 } 243 ia->ia_ifp = ifp; 244 if (!(ifp->if_flags & IFF_LOOPBACK)) 245 in_interfaces++; 246 splx(s); 247 } 248 break; 249 250 case SIOCSIFBRDADDR: 251 if ((so->so_state & SS_PRIV) == 0) 252 return (EPERM); 253 /* FALLTHROUGH */ 254 255 case SIOCGIFADDR: 256 case SIOCGIFNETMASK: 257 case SIOCGIFDSTADDR: 258 case SIOCGIFBRDADDR: 259 if (ia == (struct in_ifaddr *)0) 260 return (EADDRNOTAVAIL); 261 break; 262 } 263 switch (cmd) { 264 265 case SIOCGIFADDR: 266 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr; 267 break; 268 269 case SIOCGIFBRDADDR: 270 if ((ifp->if_flags & IFF_BROADCAST) == 0) 271 return (EINVAL); 272 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr; 273 break; 274 275 case SIOCGIFDSTADDR: 276 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 277 return (EINVAL); 278 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr; 279 break; 280 281 case SIOCGIFNETMASK: 282 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask; 283 break; 284 285 case SIOCSIFDSTADDR: 286 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 287 return (EINVAL); 288 oldaddr = ia->ia_dstaddr; 289 ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr; 290 if (ifp->if_ioctl && (error = (*ifp->if_ioctl) 291 (ifp, SIOCSIFDSTADDR, (caddr_t)ia))) { 292 ia->ia_dstaddr = oldaddr; 293 return (error); 294 } 295 if (ia->ia_flags & IFA_ROUTE) { 296 ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr; 297 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); 298 ia->ia_ifa.ifa_dstaddr = 299 (struct sockaddr *)&ia->ia_dstaddr; 300 rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP); 301 } 302 break; 303 304 case SIOCSIFBRDADDR: 305 if ((ifp->if_flags & IFF_BROADCAST) == 0) 306 return (EINVAL); 307 ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr; 308 break; 309 310 case SIOCSIFADDR: 311 return (in_ifinit(ifp, ia, 312 (struct sockaddr_in *) &ifr->ifr_addr, 1)); 313 314 case SIOCSIFNETMASK: 315 i = ifra->ifra_addr.sin_addr.s_addr; 316 ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr = i); 317 break; 318 319 case SIOCAIFADDR: 320 maskIsNew = 0; 321 hostIsNew = 1; 322 error = 0; 323 if (ia->ia_addr.sin_family == AF_INET) { 324 if (ifra->ifra_addr.sin_len == 0) { 325 ifra->ifra_addr = ia->ia_addr; 326 hostIsNew = 0; 327 } else if (ifra->ifra_addr.sin_addr.s_addr == 328 ia->ia_addr.sin_addr.s_addr) 329 hostIsNew = 0; 330 } 331 if (ifra->ifra_mask.sin_len) { 332 in_ifscrub(ifp, ia); 333 ia->ia_sockmask = ifra->ifra_mask; 334 ia->ia_subnetmask = 335 ntohl(ia->ia_sockmask.sin_addr.s_addr); 336 maskIsNew = 1; 337 } 338 if ((ifp->if_flags & IFF_POINTOPOINT) && 339 (ifra->ifra_dstaddr.sin_family == AF_INET)) { 340 in_ifscrub(ifp, ia); 341 ia->ia_dstaddr = ifra->ifra_dstaddr; 342 maskIsNew = 1; /* We lie; but the effect's the same */ 343 } 344 if (ifra->ifra_addr.sin_family == AF_INET && 345 (hostIsNew || maskIsNew)) 346 error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0); 347 if ((ifp->if_flags & IFF_BROADCAST) && 348 (ifra->ifra_broadaddr.sin_family == AF_INET)) 349 ia->ia_broadaddr = ifra->ifra_broadaddr; 350 return (error); 351 352 case SIOCDIFADDR: 353 mk = malloc(sizeof *mk, M_IPMADDR, M_WAITOK); 354 if (!mk) 355 return ENOBUFS; 356 357 in_ifscrub(ifp, ia); 358 /* 359 * Protect from ipintr() traversing address list 360 * while we're modifying it. 361 */ 362 s = splnet(); 363 364 ifa = &ia->ia_ifa; 365 TAILQ_REMOVE(&ifp->if_addrhead, ifa, ifa_link); 366 oia = ia; 367 TAILQ_REMOVE(&in_ifaddrhead, oia, ia_link); 368 if (!oia->ia_multiaddrs.lh_first) { 369 IFAFREE(&oia->ia_ifa); 370 FREE(mk, M_IPMADDR); 371 splx(s); 372 break; 373 } 374 375 /* 376 * Multicast address kludge: 377 * If there were any multicast addresses attached to this 378 * interface address, either move them to another address 379 * on this interface, or save them until such time as this 380 * interface is reconfigured for IP. 381 */ 382 IFP_TO_IA(oia->ia_ifp, ia); 383 if (ia) { /* there is another address */ 384 struct in_multi *inm; 385 for(inm = oia->ia_multiaddrs.lh_first; inm; 386 inm = inm->inm_entry.le_next) { 387 IFAFREE(&inm->inm_ia->ia_ifa); 388 ia->ia_ifa.ifa_refcnt++; 389 inm->inm_ia = ia; 390 LIST_INSERT_HEAD(&ia->ia_multiaddrs, inm, 391 inm_entry); 392 } 393 FREE(mk, M_IPMADDR); 394 } else { /* last address on this if deleted, save */ 395 struct in_multi *inm; 396 397 LIST_INIT(&mk->mk_head); 398 mk->mk_ifp = ifp; 399 400 for(inm = oia->ia_multiaddrs.lh_first; inm; 401 inm = inm->inm_entry.le_next) { 402 LIST_INSERT_HEAD(&mk->mk_head, inm, inm_entry); 403 } 404 405 if (mk->mk_head.lh_first) { 406 LIST_INSERT_HEAD(&in_mk, mk, mk_entry); 407 } else { 408 FREE(mk, M_IPMADDR); 409 } 410 } 411 412 IFAFREE((&oia->ia_ifa)); 413 splx(s); 414 break; 415 416 default: 417 if (ifp == 0 || ifp->if_ioctl == 0) 418 return (EOPNOTSUPP); 419 return ((*ifp->if_ioctl)(ifp, cmd, data)); 420 } 421 return (0); 422 } 423 424 /* 425 * Delete any existing route for an interface. 426 */ 427 static void 428 in_ifscrub(ifp, ia) 429 register struct ifnet *ifp; 430 register struct in_ifaddr *ia; 431 { 432 433 if ((ia->ia_flags & IFA_ROUTE) == 0) 434 return; 435 if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT)) 436 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); 437 else 438 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0); 439 ia->ia_flags &= ~IFA_ROUTE; 440 } 441 442 /* 443 * Initialize an interface's internet address 444 * and routing table entry. 445 */ 446 static int 447 in_ifinit(ifp, ia, sin, scrub) 448 register struct ifnet *ifp; 449 register struct in_ifaddr *ia; 450 struct sockaddr_in *sin; 451 int scrub; 452 { 453 register u_long i = ntohl(sin->sin_addr.s_addr); 454 struct sockaddr_in oldaddr; 455 int s = splimp(), flags = RTF_UP, error; 456 struct multi_kludge *mk; 457 458 oldaddr = ia->ia_addr; 459 ia->ia_addr = *sin; 460 /* 461 * Give the interface a chance to initialize 462 * if this is its first address, 463 * and to validate the address if necessary. 464 */ 465 if (ifp->if_ioctl && 466 (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia))) { 467 splx(s); 468 ia->ia_addr = oldaddr; 469 return (error); 470 } 471 splx(s); 472 if (scrub) { 473 ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr; 474 in_ifscrub(ifp, ia); 475 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr; 476 } 477 if (IN_CLASSA(i)) 478 ia->ia_netmask = IN_CLASSA_NET; 479 else if (IN_CLASSB(i)) 480 ia->ia_netmask = IN_CLASSB_NET; 481 else 482 ia->ia_netmask = IN_CLASSC_NET; 483 /* 484 * The subnet mask usually includes at least the standard network part, 485 * but may may be smaller in the case of supernetting. 486 * If it is set, we believe it. 487 */ 488 if (ia->ia_subnetmask == 0) { 489 ia->ia_subnetmask = ia->ia_netmask; 490 ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask); 491 } else 492 ia->ia_netmask &= ia->ia_subnetmask; 493 ia->ia_net = i & ia->ia_netmask; 494 ia->ia_subnet = i & ia->ia_subnetmask; 495 in_socktrim(&ia->ia_sockmask); 496 /* 497 * Add route for the network. 498 */ 499 ia->ia_ifa.ifa_metric = ifp->if_metric; 500 if (ifp->if_flags & IFF_BROADCAST) { 501 ia->ia_broadaddr.sin_addr.s_addr = 502 htonl(ia->ia_subnet | ~ia->ia_subnetmask); 503 ia->ia_netbroadcast.s_addr = 504 htonl(ia->ia_net | ~ ia->ia_netmask); 505 } else if (ifp->if_flags & IFF_LOOPBACK) { 506 ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr; 507 flags |= RTF_HOST; 508 } else if (ifp->if_flags & IFF_POINTOPOINT) { 509 if (ia->ia_dstaddr.sin_family != AF_INET) 510 return (0); 511 flags |= RTF_HOST; 512 } 513 if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD, flags)) == 0) 514 ia->ia_flags |= IFA_ROUTE; 515 516 LIST_INIT(&ia->ia_multiaddrs); 517 /* 518 * If the interface supports multicast, join the "all hosts" 519 * multicast group on that interface. 520 */ 521 if (ifp->if_flags & IFF_MULTICAST) { 522 struct in_addr addr; 523 524 /* 525 * Continuation of multicast address hack: 526 * If there was a multicast group list previously saved 527 * for this interface, then we re-attach it to the first 528 * address configured on the i/f. 529 */ 530 for(mk = in_mk.lh_first; mk; mk = mk->mk_entry.le_next) { 531 if(mk->mk_ifp == ifp) { 532 struct in_multi *inm; 533 534 for(inm = mk->mk_head.lh_first; inm; 535 inm = inm->inm_entry.le_next) { 536 IFAFREE(&inm->inm_ia->ia_ifa); 537 ia->ia_ifa.ifa_refcnt++; 538 inm->inm_ia = ia; 539 LIST_INSERT_HEAD(&ia->ia_multiaddrs, 540 inm, inm_entry); 541 } 542 LIST_REMOVE(mk, mk_entry); 543 free(mk, M_IPMADDR); 544 break; 545 } 546 } 547 548 addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP); 549 in_addmulti(&addr, ifp); 550 } 551 return (error); 552 } 553 554 555 /* 556 * Return 1 if the address might be a local broadcast address. 557 */ 558 int 559 in_broadcast(in, ifp) 560 struct in_addr in; 561 struct ifnet *ifp; 562 { 563 register struct ifaddr *ifa; 564 u_long t; 565 566 if (in.s_addr == INADDR_BROADCAST || 567 in.s_addr == INADDR_ANY) 568 return 1; 569 if ((ifp->if_flags & IFF_BROADCAST) == 0) 570 return 0; 571 t = ntohl(in.s_addr); 572 /* 573 * Look through the list of addresses for a match 574 * with a broadcast address. 575 */ 576 #define ia ((struct in_ifaddr *)ifa) 577 for (ifa = ifp->if_addrhead.tqh_first; ifa; 578 ifa = ifa->ifa_link.tqe_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 /* 587 * Check for an all one subnetmask. These 588 * only exist when an interface gets a secondary 589 * address. 590 */ 591 ia->ia_subnetmask != (u_long)0xffffffff) 592 return 1; 593 return (0); 594 #undef ia 595 } 596 /* 597 * Add an address to the list of IP multicast addresses for a given interface. 598 */ 599 struct in_multi * 600 in_addmulti(ap, ifp) 601 register struct in_addr *ap; 602 register struct ifnet *ifp; 603 { 604 register struct in_multi *inm; 605 struct ifreq ifr; 606 struct in_ifaddr *ia; 607 int s = splnet(); 608 609 /* 610 * See if address already in list. 611 */ 612 IN_LOOKUP_MULTI(*ap, ifp, inm); 613 if (inm != NULL) { 614 /* 615 * Found it; just increment the reference count. 616 */ 617 ++inm->inm_refcount; 618 } 619 else { 620 /* 621 * New address; allocate a new multicast record 622 * and link it into the interface's multicast list. 623 */ 624 inm = (struct in_multi *)malloc(sizeof(*inm), 625 M_IPMADDR, M_NOWAIT); 626 if (inm == NULL) { 627 splx(s); 628 return (NULL); 629 } 630 inm->inm_addr = *ap; 631 inm->inm_ifp = ifp; 632 inm->inm_refcount = 1; 633 IFP_TO_IA(ifp, ia); 634 if (ia == NULL) { 635 free(inm, M_IPMADDR); 636 splx(s); 637 return (NULL); 638 } 639 inm->inm_ia = ia; 640 ia->ia_ifa.ifa_refcnt++; /* gain a reference */ 641 LIST_INSERT_HEAD(&ia->ia_multiaddrs, inm, inm_entry); 642 643 /* 644 * Ask the network driver to update its multicast reception 645 * filter appropriately for the new address. 646 */ 647 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_family = AF_INET; 648 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr = *ap; 649 if ((ifp->if_ioctl == NULL) || 650 (*ifp->if_ioctl)(ifp, SIOCADDMULTI,(caddr_t)&ifr) != 0) { 651 LIST_REMOVE(inm, inm_entry); 652 IFAFREE(&ia->ia_ifa); /* release reference */ 653 free(inm, M_IPMADDR); 654 splx(s); 655 return (NULL); 656 } 657 /* 658 * Let IGMP know that we have joined a new IP multicast group. 659 */ 660 igmp_joingroup(inm); 661 } 662 splx(s); 663 return (inm); 664 } 665 666 /* 667 * Delete a multicast address record. 668 */ 669 void 670 in_delmulti(inm) 671 register struct in_multi *inm; 672 { 673 struct ifreq ifr; 674 int s = splnet(); 675 676 if (--inm->inm_refcount == 0) { 677 /* 678 * No remaining claims to this record; let IGMP know that 679 * we are leaving the multicast group. 680 */ 681 igmp_leavegroup(inm); 682 /* 683 * Unlink from list. 684 */ 685 LIST_REMOVE(inm, inm_entry); 686 IFAFREE(&inm->inm_ia->ia_ifa); /* release reference */ 687 688 /* 689 * Notify the network driver to update its multicast reception 690 * filter. 691 */ 692 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_family = AF_INET; 693 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_addr = 694 inm->inm_addr; 695 (*inm->inm_ifp->if_ioctl)(inm->inm_ifp, SIOCDELMULTI, 696 (caddr_t)&ifr); 697 free(inm, M_IPMADDR); 698 } 699 splx(s); 700 } 701