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 1.15 1995/07/17 15:15:15 wollman 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 /* 69 * Return the network number from an internet address. 70 */ 71 u_long 72 in_netof(in) 73 struct in_addr in; 74 { 75 register u_long i = ntohl(in.s_addr); 76 register u_long net; 77 register struct in_ifaddr *ia; 78 79 if (IN_CLASSA(i)) 80 net = i & IN_CLASSA_NET; 81 else if (IN_CLASSB(i)) 82 net = i & IN_CLASSB_NET; 83 else if (IN_CLASSC(i)) 84 net = i & IN_CLASSC_NET; 85 else if (IN_CLASSD(i)) 86 net = i & IN_CLASSD_NET; 87 else 88 return (0); 89 90 /* 91 * Check whether network is a subnet; 92 * if so, return subnet number. 93 */ 94 for (ia = in_ifaddr; ia; ia = ia->ia_next) 95 if (net == ia->ia_net) 96 return (i & ia->ia_subnetmask); 97 return (net); 98 } 99 100 #ifndef SUBNETSARELOCAL 101 #define SUBNETSARELOCAL 1 102 #endif 103 int subnetsarelocal = SUBNETSARELOCAL; 104 /* 105 * Return 1 if an internet address is for a ``local'' host 106 * (one to which we have a connection). If subnetsarelocal 107 * is true, this includes other subnets of the local net. 108 * Otherwise, it includes only the directly-connected (sub)nets. 109 */ 110 int 111 in_localaddr(in) 112 struct in_addr in; 113 { 114 register u_long i = ntohl(in.s_addr); 115 register struct in_ifaddr *ia; 116 117 if (subnetsarelocal) { 118 for (ia = in_ifaddr; ia; ia = ia->ia_next) 119 if ((i & ia->ia_netmask) == ia->ia_net) 120 return (1); 121 } else { 122 for (ia = in_ifaddr; ia; ia = ia->ia_next) 123 if ((i & ia->ia_subnetmask) == ia->ia_subnet) 124 return (1); 125 } 126 return (0); 127 } 128 129 /* 130 * Determine whether an IP address is in a reserved set of addresses 131 * that may not be forwarded, or whether datagrams to that destination 132 * may be forwarded. 133 */ 134 int 135 in_canforward(in) 136 struct in_addr in; 137 { 138 register u_long i = ntohl(in.s_addr); 139 register u_long net; 140 141 if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i)) 142 return (0); 143 if (IN_CLASSA(i)) { 144 net = i & IN_CLASSA_NET; 145 if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT)) 146 return (0); 147 } 148 return (1); 149 } 150 151 /* 152 * Trim a mask in a sockaddr 153 */ 154 void 155 in_socktrim(ap) 156 struct sockaddr_in *ap; 157 { 158 register char *cplim = (char *) &ap->sin_addr; 159 register char *cp = (char *) (&ap->sin_addr + 1); 160 161 ap->sin_len = 0; 162 while (--cp >= cplim) 163 if (*cp) { 164 (ap)->sin_len = cp - (char *) (ap) + 1; 165 break; 166 } 167 } 168 169 int in_interfaces; /* number of external internet interfaces */ 170 171 /* 172 * Generic internet control operations (ioctl's). 173 * Ifp is 0 if not an interface-specific ioctl. 174 */ 175 /* ARGSUSED */ 176 int 177 in_control(so, cmd, data, ifp) 178 struct socket *so; 179 u_long cmd; 180 caddr_t data; 181 register struct ifnet *ifp; 182 { 183 register struct ifreq *ifr = (struct ifreq *)data; 184 register struct in_ifaddr *ia = 0; 185 register struct ifaddr *ifa; 186 struct in_ifaddr *oia; 187 struct in_aliasreq *ifra = (struct in_aliasreq *)data; 188 struct sockaddr_in oldaddr; 189 int error, hostIsNew, maskIsNew; 190 u_long i; 191 struct multi_kludge *mk; 192 193 /* 194 * Find address for this interface, if it exists. 195 */ 196 if (ifp) 197 for (ia = in_ifaddr; ia; ia = ia->ia_next) 198 if (ia->ia_ifp == ifp) 199 break; 200 201 switch (cmd) { 202 203 case SIOCAIFADDR: 204 case SIOCDIFADDR: 205 if (ifra->ifra_addr.sin_family == AF_INET) { 206 for (oia = ia; ia; ia = ia->ia_next) { 207 if (ia->ia_ifp == ifp && 208 ia->ia_addr.sin_addr.s_addr == 209 ifra->ifra_addr.sin_addr.s_addr) 210 break; 211 } 212 if ((ifp->if_flags & IFF_POINTOPOINT) 213 && (cmd == SIOCAIFADDR) 214 && (ifra->ifra_dstaddr.sin_addr.s_addr 215 == INADDR_ANY)) { 216 return EDESTADDRREQ; 217 } 218 } 219 if (cmd == SIOCDIFADDR && ia == 0) 220 return (EADDRNOTAVAIL); 221 /* FALLTHROUGH */ 222 case SIOCSIFADDR: 223 case SIOCSIFNETMASK: 224 case SIOCSIFDSTADDR: 225 if ((so->so_state & SS_PRIV) == 0) 226 return (EPERM); 227 228 if (ifp == 0) 229 panic("in_control"); 230 if (ia == (struct in_ifaddr *)0) { 231 oia = (struct in_ifaddr *) 232 malloc(sizeof *oia, M_IFADDR, M_WAITOK); 233 if (oia == (struct in_ifaddr *)NULL) 234 return (ENOBUFS); 235 bzero((caddr_t)oia, sizeof *oia); 236 ia = in_ifaddr; 237 if (ia) { 238 for ( ; ia->ia_next; ia = ia->ia_next) 239 continue; 240 ia->ia_next = oia; 241 } else 242 in_ifaddr = oia; 243 ia = oia; 244 ifa = ifp->if_addrlist; 245 if (ifa) { 246 for ( ; ifa->ifa_next; ifa = ifa->ifa_next) 247 continue; 248 ifa->ifa_next = (struct ifaddr *) ia; 249 } else 250 ifp->if_addrlist = (struct ifaddr *) ia; 251 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr; 252 ia->ia_ifa.ifa_dstaddr 253 = (struct sockaddr *)&ia->ia_dstaddr; 254 ia->ia_ifa.ifa_netmask 255 = (struct sockaddr *)&ia->ia_sockmask; 256 ia->ia_sockmask.sin_len = 8; 257 if (ifp->if_flags & IFF_BROADCAST) { 258 ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr); 259 ia->ia_broadaddr.sin_family = AF_INET; 260 } 261 ia->ia_ifp = ifp; 262 if (!(ifp->if_flags & IFF_LOOPBACK)) 263 in_interfaces++; 264 } 265 break; 266 267 case SIOCSIFBRDADDR: 268 if ((so->so_state & SS_PRIV) == 0) 269 return (EPERM); 270 /* FALLTHROUGH */ 271 272 case SIOCGIFADDR: 273 case SIOCGIFNETMASK: 274 case SIOCGIFDSTADDR: 275 case SIOCGIFBRDADDR: 276 if (ia == (struct in_ifaddr *)0) 277 return (EADDRNOTAVAIL); 278 break; 279 } 280 switch (cmd) { 281 282 case SIOCGIFADDR: 283 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr; 284 break; 285 286 case SIOCGIFBRDADDR: 287 if ((ifp->if_flags & IFF_BROADCAST) == 0) 288 return (EINVAL); 289 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr; 290 break; 291 292 case SIOCGIFDSTADDR: 293 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 294 return (EINVAL); 295 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr; 296 break; 297 298 case SIOCGIFNETMASK: 299 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask; 300 break; 301 302 case SIOCSIFDSTADDR: 303 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 304 return (EINVAL); 305 oldaddr = ia->ia_dstaddr; 306 ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr; 307 if (ifp->if_ioctl && (error = (*ifp->if_ioctl) 308 (ifp, SIOCSIFDSTADDR, (caddr_t)ia))) { 309 ia->ia_dstaddr = oldaddr; 310 return (error); 311 } 312 if (ia->ia_flags & IFA_ROUTE) { 313 ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr; 314 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); 315 ia->ia_ifa.ifa_dstaddr = 316 (struct sockaddr *)&ia->ia_dstaddr; 317 rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP); 318 } 319 break; 320 321 case SIOCSIFBRDADDR: 322 if ((ifp->if_flags & IFF_BROADCAST) == 0) 323 return (EINVAL); 324 ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr; 325 break; 326 327 case SIOCSIFADDR: 328 return (in_ifinit(ifp, ia, 329 (struct sockaddr_in *) &ifr->ifr_addr, 1)); 330 331 case SIOCSIFNETMASK: 332 i = ifra->ifra_addr.sin_addr.s_addr; 333 ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr = i); 334 break; 335 336 case SIOCAIFADDR: 337 maskIsNew = 0; 338 hostIsNew = 1; 339 error = 0; 340 if (ia->ia_addr.sin_family == AF_INET) { 341 if (ifra->ifra_addr.sin_len == 0) { 342 ifra->ifra_addr = ia->ia_addr; 343 hostIsNew = 0; 344 } else if (ifra->ifra_addr.sin_addr.s_addr == 345 ia->ia_addr.sin_addr.s_addr) 346 hostIsNew = 0; 347 } 348 if (ifra->ifra_mask.sin_len) { 349 in_ifscrub(ifp, ia); 350 ia->ia_sockmask = ifra->ifra_mask; 351 ia->ia_subnetmask = 352 ntohl(ia->ia_sockmask.sin_addr.s_addr); 353 maskIsNew = 1; 354 } 355 if ((ifp->if_flags & IFF_POINTOPOINT) && 356 (ifra->ifra_dstaddr.sin_family == AF_INET)) { 357 in_ifscrub(ifp, ia); 358 ia->ia_dstaddr = ifra->ifra_dstaddr; 359 maskIsNew = 1; /* We lie; but the effect's the same */ 360 } 361 if (ifra->ifra_addr.sin_family == AF_INET && 362 (hostIsNew || maskIsNew)) 363 error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0); 364 if ((ifp->if_flags & IFF_BROADCAST) && 365 (ifra->ifra_broadaddr.sin_family == AF_INET)) 366 ia->ia_broadaddr = ifra->ifra_broadaddr; 367 return (error); 368 369 case SIOCDIFADDR: 370 mk = malloc(sizeof *mk, M_IPMADDR, M_WAITOK); 371 if (!mk) 372 return ENOBUFS; 373 374 in_ifscrub(ifp, ia); 375 if ((ifa = ifp->if_addrlist) == (struct ifaddr *)ia) 376 ifp->if_addrlist = ifa->ifa_next; 377 else { 378 while (ifa->ifa_next && 379 (ifa->ifa_next != (struct ifaddr *)ia)) 380 ifa = ifa->ifa_next; 381 if (ifa->ifa_next) 382 ifa->ifa_next = ((struct ifaddr *)ia)->ifa_next; 383 else 384 printf("Couldn't unlink inifaddr from ifp\n"); 385 } 386 oia = ia; 387 if (oia == (ia = in_ifaddr)) 388 in_ifaddr = ia->ia_next; 389 else { 390 while (ia->ia_next && (ia->ia_next != oia)) 391 ia = ia->ia_next; 392 if (ia->ia_next) 393 ia->ia_next = oia->ia_next; 394 else 395 printf("Didn't unlink inifadr from list\n"); 396 } 397 398 if (!oia->ia_multiaddrs.lh_first) { 399 IFAFREE(&oia->ia_ifa); 400 FREE(mk, M_IPMADDR); 401 break; 402 } 403 404 /* 405 * Multicast address kludge: 406 * If there were any multicast addresses attached to this 407 * interface address, either move them to another address 408 * on this interface, or save them until such time as this 409 * interface is reconfigured for IP. 410 */ 411 IFP_TO_IA(oia->ia_ifp, ia); 412 if (ia) { /* there is another address */ 413 struct in_multi *inm; 414 for(inm = oia->ia_multiaddrs.lh_first; inm; 415 inm = inm->inm_entry.le_next) { 416 IFAFREE(&inm->inm_ia->ia_ifa); 417 ia->ia_ifa.ifa_refcnt++; 418 inm->inm_ia = ia; 419 LIST_INSERT_HEAD(&ia->ia_multiaddrs, inm, 420 inm_entry); 421 } 422 FREE(mk, M_IPMADDR); 423 } else { /* last address on this if deleted, save */ 424 struct in_multi *inm; 425 426 LIST_INIT(&mk->mk_head); 427 mk->mk_ifp = ifp; 428 429 for(inm = oia->ia_multiaddrs.lh_first; inm; 430 inm = inm->inm_entry.le_next) { 431 LIST_INSERT_HEAD(&mk->mk_head, inm, inm_entry); 432 } 433 434 if (mk->mk_head.lh_first) { 435 LIST_INSERT_HEAD(&in_mk, mk, mk_entry); 436 } else { 437 FREE(mk, M_IPMADDR); 438 } 439 } 440 441 IFAFREE((&oia->ia_ifa)); 442 break; 443 444 default: 445 if (ifp == 0 || ifp->if_ioctl == 0) 446 return (EOPNOTSUPP); 447 return ((*ifp->if_ioctl)(ifp, cmd, data)); 448 } 449 return (0); 450 } 451 452 /* 453 * Delete any existing route for an interface. 454 */ 455 void 456 in_ifscrub(ifp, ia) 457 register struct ifnet *ifp; 458 register struct in_ifaddr *ia; 459 { 460 461 if ((ia->ia_flags & IFA_ROUTE) == 0) 462 return; 463 if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT)) 464 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); 465 else 466 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0); 467 ia->ia_flags &= ~IFA_ROUTE; 468 } 469 470 /* 471 * Initialize an interface's internet address 472 * and routing table entry. 473 */ 474 int 475 in_ifinit(ifp, ia, sin, scrub) 476 register struct ifnet *ifp; 477 register struct in_ifaddr *ia; 478 struct sockaddr_in *sin; 479 int scrub; 480 { 481 register u_long i = ntohl(sin->sin_addr.s_addr); 482 struct sockaddr_in oldaddr; 483 int s = splimp(), flags = RTF_UP, error; 484 struct multi_kludge *mk; 485 486 oldaddr = ia->ia_addr; 487 ia->ia_addr = *sin; 488 /* 489 * Give the interface a chance to initialize 490 * if this is its first address, 491 * and to validate the address if necessary. 492 */ 493 if (ifp->if_ioctl && 494 (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia))) { 495 splx(s); 496 ia->ia_addr = oldaddr; 497 return (error); 498 } 499 splx(s); 500 if (scrub) { 501 ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr; 502 in_ifscrub(ifp, ia); 503 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr; 504 } 505 if (IN_CLASSA(i)) 506 ia->ia_netmask = IN_CLASSA_NET; 507 else if (IN_CLASSB(i)) 508 ia->ia_netmask = IN_CLASSB_NET; 509 else 510 ia->ia_netmask = IN_CLASSC_NET; 511 /* 512 * The subnet mask usually includes at least the standard network part, 513 * but may may be smaller in the case of supernetting. 514 * If it is set, we believe it. 515 */ 516 if (ia->ia_subnetmask == 0) { 517 ia->ia_subnetmask = ia->ia_netmask; 518 ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask); 519 } else 520 ia->ia_netmask &= ia->ia_subnetmask; 521 ia->ia_net = i & ia->ia_netmask; 522 ia->ia_subnet = i & ia->ia_subnetmask; 523 in_socktrim(&ia->ia_sockmask); 524 /* 525 * Add route for the network. 526 */ 527 ia->ia_ifa.ifa_metric = ifp->if_metric; 528 if (ifp->if_flags & IFF_BROADCAST) { 529 ia->ia_broadaddr.sin_addr.s_addr = 530 htonl(ia->ia_subnet | ~ia->ia_subnetmask); 531 ia->ia_netbroadcast.s_addr = 532 htonl(ia->ia_net | ~ ia->ia_netmask); 533 } else if (ifp->if_flags & IFF_LOOPBACK) { 534 ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr; 535 flags |= RTF_HOST; 536 } else if (ifp->if_flags & IFF_POINTOPOINT) { 537 if (ia->ia_dstaddr.sin_family != AF_INET) 538 return (0); 539 flags |= RTF_HOST; 540 } 541 if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD, flags)) == 0) 542 ia->ia_flags |= IFA_ROUTE; 543 544 LIST_INIT(&ia->ia_multiaddrs); 545 /* 546 * If the interface supports multicast, join the "all hosts" 547 * multicast group on that interface. 548 */ 549 if (ifp->if_flags & IFF_MULTICAST) { 550 struct in_addr addr; 551 552 /* 553 * Continuation of multicast address hack: 554 * If there was a multicast group list previously saved 555 * for this interface, then we re-attach it to the first 556 * address configured on the i/f. 557 */ 558 for(mk = in_mk.lh_first; mk; mk = mk->mk_entry.le_next) { 559 if(mk->mk_ifp == ifp) { 560 struct in_multi *inm; 561 562 for(inm = mk->mk_head.lh_first; inm; 563 inm = inm->inm_entry.le_next) { 564 IFAFREE(&inm->inm_ia->ia_ifa); 565 ia->ia_ifa.ifa_refcnt++; 566 inm->inm_ia = ia; 567 LIST_INSERT_HEAD(&ia->ia_multiaddrs, 568 inm, inm_entry); 569 } 570 LIST_REMOVE(mk, mk_entry); 571 free(mk, M_IPMADDR); 572 break; 573 } 574 } 575 576 addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP); 577 in_addmulti(&addr, ifp); 578 } 579 return (error); 580 } 581 582 583 /* 584 * Return 1 if the address might be a local broadcast address. 585 */ 586 int 587 in_broadcast(in, ifp) 588 struct in_addr in; 589 struct ifnet *ifp; 590 { 591 register struct ifaddr *ifa; 592 u_long t; 593 594 if (in.s_addr == INADDR_BROADCAST || 595 in.s_addr == INADDR_ANY) 596 return 1; 597 if ((ifp->if_flags & IFF_BROADCAST) == 0) 598 return 0; 599 t = ntohl(in.s_addr); 600 /* 601 * Look through the list of addresses for a match 602 * with a broadcast address. 603 */ 604 #define ia ((struct in_ifaddr *)ifa) 605 for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next) 606 if (ifa->ifa_addr->sa_family == AF_INET && 607 (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr || 608 in.s_addr == ia->ia_netbroadcast.s_addr || 609 /* 610 * Check for old-style (host 0) broadcast. 611 */ 612 t == ia->ia_subnet || t == ia->ia_net)) 613 return 1; 614 return (0); 615 #undef ia 616 } 617 /* 618 * Add an address to the list of IP multicast addresses for a given interface. 619 */ 620 struct in_multi * 621 in_addmulti(ap, ifp) 622 register struct in_addr *ap; 623 register struct ifnet *ifp; 624 { 625 register struct in_multi *inm; 626 struct ifreq ifr; 627 struct in_ifaddr *ia; 628 int s = splnet(); 629 630 /* 631 * See if address already in list. 632 */ 633 IN_LOOKUP_MULTI(*ap, ifp, inm); 634 if (inm != NULL) { 635 /* 636 * Found it; just increment the reference count. 637 */ 638 ++inm->inm_refcount; 639 } 640 else { 641 /* 642 * New address; allocate a new multicast record 643 * and link it into the interface's multicast list. 644 */ 645 inm = (struct in_multi *)malloc(sizeof(*inm), 646 M_IPMADDR, M_NOWAIT); 647 if (inm == NULL) { 648 splx(s); 649 return (NULL); 650 } 651 inm->inm_addr = *ap; 652 inm->inm_ifp = ifp; 653 inm->inm_refcount = 1; 654 IFP_TO_IA(ifp, ia); 655 if (ia == NULL) { 656 free(inm, M_IPMADDR); 657 splx(s); 658 return (NULL); 659 } 660 inm->inm_ia = ia; 661 ia->ia_ifa.ifa_refcnt++; /* gain a reference */ 662 LIST_INSERT_HEAD(&ia->ia_multiaddrs, inm, inm_entry); 663 664 /* 665 * Ask the network driver to update its multicast reception 666 * filter appropriately for the new address. 667 */ 668 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_family = AF_INET; 669 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr = *ap; 670 if ((ifp->if_ioctl == NULL) || 671 (*ifp->if_ioctl)(ifp, SIOCADDMULTI,(caddr_t)&ifr) != 0) { 672 LIST_REMOVE(inm, inm_entry); 673 IFAFREE(&ia->ia_ifa); /* release reference */ 674 free(inm, M_IPMADDR); 675 splx(s); 676 return (NULL); 677 } 678 /* 679 * Let IGMP know that we have joined a new IP multicast group. 680 */ 681 igmp_joingroup(inm); 682 } 683 splx(s); 684 return (inm); 685 } 686 687 /* 688 * Delete a multicast address record. 689 */ 690 void 691 in_delmulti(inm) 692 register struct in_multi *inm; 693 { 694 register struct in_multi **p; 695 struct ifreq ifr; 696 int s = splnet(); 697 698 if (--inm->inm_refcount == 0) { 699 /* 700 * No remaining claims to this record; let IGMP know that 701 * we are leaving the multicast group. 702 */ 703 igmp_leavegroup(inm); 704 /* 705 * Unlink from list. 706 */ 707 LIST_REMOVE(inm, inm_entry); 708 IFAFREE(&inm->inm_ia->ia_ifa); /* release reference */ 709 710 /* 711 * Notify the network driver to update its multicast reception 712 * filter. 713 */ 714 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_family = AF_INET; 715 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_addr = 716 inm->inm_addr; 717 (*inm->inm_ifp->if_ioctl)(inm->inm_ifp, SIOCDELMULTI, 718 (caddr_t)&ifr); 719 free(inm, M_IPMADDR); 720 } 721 splx(s); 722 } 723