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 1.24 1996/04/07 06:59:52 davidg 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_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, *iap; 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, s; 164 u_long i; 165 struct multi_kludge *mk; 166 167 /* 168 * Find address for this interface, if it exists. 169 * 170 * If an alias address was specified, find that one instead of 171 * the first one on the interface. 172 */ 173 if (ifp) 174 for (iap = in_ifaddr; iap; iap = iap->ia_next) 175 if (iap->ia_ifp == ifp) { 176 if (((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr.s_addr == 177 iap->ia_addr.sin_addr.s_addr) { 178 ia = iap; 179 break; 180 } else if (ia == NULL) { 181 ia = iap; 182 if (ifr->ifr_addr.sa_family != AF_INET) 183 break; 184 } 185 } 186 187 switch (cmd) { 188 189 case SIOCAIFADDR: 190 case SIOCDIFADDR: 191 if (ifra->ifra_addr.sin_family == AF_INET) { 192 for (oia = ia; ia; ia = ia->ia_next) { 193 if (ia->ia_ifp == ifp && 194 ia->ia_addr.sin_addr.s_addr == 195 ifra->ifra_addr.sin_addr.s_addr) 196 break; 197 } 198 if ((ifp->if_flags & IFF_POINTOPOINT) 199 && (cmd == SIOCAIFADDR) 200 && (ifra->ifra_dstaddr.sin_addr.s_addr 201 == INADDR_ANY)) { 202 return EDESTADDRREQ; 203 } 204 } 205 if (cmd == SIOCDIFADDR && ia == 0) 206 return (EADDRNOTAVAIL); 207 /* FALLTHROUGH */ 208 case SIOCSIFADDR: 209 case SIOCSIFNETMASK: 210 case SIOCSIFDSTADDR: 211 if ((so->so_state & SS_PRIV) == 0) 212 return (EPERM); 213 214 if (ifp == 0) 215 panic("in_control"); 216 if (ia == (struct in_ifaddr *)0) { 217 oia = (struct in_ifaddr *) 218 malloc(sizeof *oia, M_IFADDR, M_WAITOK); 219 if (oia == (struct in_ifaddr *)NULL) 220 return (ENOBUFS); 221 bzero((caddr_t)oia, sizeof *oia); 222 ia = in_ifaddr; 223 /* 224 * Protect from ipintr() traversing address list 225 * while we're modifying it. 226 */ 227 s = splnet(); 228 229 if (ia) { 230 for ( ; ia->ia_next; ia = ia->ia_next) 231 continue; 232 ia->ia_next = oia; 233 } else 234 in_ifaddr = oia; 235 ia = oia; 236 ifa = ifp->if_addrlist; 237 if (ifa) { 238 for ( ; ifa->ifa_next; ifa = ifa->ifa_next) 239 continue; 240 ifa->ifa_next = (struct ifaddr *) ia; 241 } else 242 ifp->if_addrlist = (struct ifaddr *) ia; 243 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr; 244 ia->ia_ifa.ifa_dstaddr 245 = (struct sockaddr *)&ia->ia_dstaddr; 246 ia->ia_ifa.ifa_netmask 247 = (struct sockaddr *)&ia->ia_sockmask; 248 ia->ia_sockmask.sin_len = 8; 249 if (ifp->if_flags & IFF_BROADCAST) { 250 ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr); 251 ia->ia_broadaddr.sin_family = AF_INET; 252 } 253 ia->ia_ifp = ifp; 254 if (!(ifp->if_flags & IFF_LOOPBACK)) 255 in_interfaces++; 256 splx(s); 257 } 258 break; 259 260 case SIOCSIFBRDADDR: 261 if ((so->so_state & SS_PRIV) == 0) 262 return (EPERM); 263 /* FALLTHROUGH */ 264 265 case SIOCGIFADDR: 266 case SIOCGIFNETMASK: 267 case SIOCGIFDSTADDR: 268 case SIOCGIFBRDADDR: 269 if (ia == (struct in_ifaddr *)0) 270 return (EADDRNOTAVAIL); 271 break; 272 } 273 switch (cmd) { 274 275 case SIOCGIFADDR: 276 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr; 277 break; 278 279 case SIOCGIFBRDADDR: 280 if ((ifp->if_flags & IFF_BROADCAST) == 0) 281 return (EINVAL); 282 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr; 283 break; 284 285 case SIOCGIFDSTADDR: 286 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 287 return (EINVAL); 288 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr; 289 break; 290 291 case SIOCGIFNETMASK: 292 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask; 293 break; 294 295 case SIOCSIFDSTADDR: 296 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 297 return (EINVAL); 298 oldaddr = ia->ia_dstaddr; 299 ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr; 300 if (ifp->if_ioctl && (error = (*ifp->if_ioctl) 301 (ifp, SIOCSIFDSTADDR, (caddr_t)ia))) { 302 ia->ia_dstaddr = oldaddr; 303 return (error); 304 } 305 if (ia->ia_flags & IFA_ROUTE) { 306 ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr; 307 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); 308 ia->ia_ifa.ifa_dstaddr = 309 (struct sockaddr *)&ia->ia_dstaddr; 310 rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP); 311 } 312 break; 313 314 case SIOCSIFBRDADDR: 315 if ((ifp->if_flags & IFF_BROADCAST) == 0) 316 return (EINVAL); 317 ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr; 318 break; 319 320 case SIOCSIFADDR: 321 return (in_ifinit(ifp, ia, 322 (struct sockaddr_in *) &ifr->ifr_addr, 1)); 323 324 case SIOCSIFNETMASK: 325 i = ifra->ifra_addr.sin_addr.s_addr; 326 ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr = i); 327 break; 328 329 case SIOCAIFADDR: 330 maskIsNew = 0; 331 hostIsNew = 1; 332 error = 0; 333 if (ia->ia_addr.sin_family == AF_INET) { 334 if (ifra->ifra_addr.sin_len == 0) { 335 ifra->ifra_addr = ia->ia_addr; 336 hostIsNew = 0; 337 } else if (ifra->ifra_addr.sin_addr.s_addr == 338 ia->ia_addr.sin_addr.s_addr) 339 hostIsNew = 0; 340 } 341 if (ifra->ifra_mask.sin_len) { 342 in_ifscrub(ifp, ia); 343 ia->ia_sockmask = ifra->ifra_mask; 344 ia->ia_subnetmask = 345 ntohl(ia->ia_sockmask.sin_addr.s_addr); 346 maskIsNew = 1; 347 } 348 if ((ifp->if_flags & IFF_POINTOPOINT) && 349 (ifra->ifra_dstaddr.sin_family == AF_INET)) { 350 in_ifscrub(ifp, ia); 351 ia->ia_dstaddr = ifra->ifra_dstaddr; 352 maskIsNew = 1; /* We lie; but the effect's the same */ 353 } 354 if (ifra->ifra_addr.sin_family == AF_INET && 355 (hostIsNew || maskIsNew)) 356 error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0); 357 if ((ifp->if_flags & IFF_BROADCAST) && 358 (ifra->ifra_broadaddr.sin_family == AF_INET)) 359 ia->ia_broadaddr = ifra->ifra_broadaddr; 360 return (error); 361 362 case SIOCDIFADDR: 363 mk = malloc(sizeof *mk, M_IPMADDR, M_WAITOK); 364 if (!mk) 365 return ENOBUFS; 366 367 in_ifscrub(ifp, ia); 368 /* 369 * Protect from ipintr() traversing address list 370 * while we're modifying it. 371 */ 372 s = splnet(); 373 374 if ((ifa = ifp->if_addrlist) == (struct ifaddr *)ia) 375 ifp->if_addrlist = ifa->ifa_next; 376 else { 377 while (ifa->ifa_next && 378 (ifa->ifa_next != (struct ifaddr *)ia)) 379 ifa = ifa->ifa_next; 380 if (ifa->ifa_next) 381 ifa->ifa_next = ((struct ifaddr *)ia)->ifa_next; 382 else 383 printf("Couldn't unlink inifaddr from ifp\n"); 384 } 385 oia = ia; 386 if (oia == (ia = in_ifaddr)) 387 in_ifaddr = ia->ia_next; 388 else { 389 while (ia->ia_next && (ia->ia_next != oia)) 390 ia = ia->ia_next; 391 if (ia->ia_next) 392 ia->ia_next = oia->ia_next; 393 else 394 printf("Didn't unlink inifadr from list\n"); 395 } 396 397 if (!oia->ia_multiaddrs.lh_first) { 398 IFAFREE(&oia->ia_ifa); 399 FREE(mk, M_IPMADDR); 400 splx(s); 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 splx(s); 443 break; 444 445 default: 446 if (ifp == 0 || ifp->if_ioctl == 0) 447 return (EOPNOTSUPP); 448 return ((*ifp->if_ioctl)(ifp, cmd, data)); 449 } 450 return (0); 451 } 452 453 /* 454 * Delete any existing route for an interface. 455 */ 456 static void 457 in_ifscrub(ifp, ia) 458 register struct ifnet *ifp; 459 register struct in_ifaddr *ia; 460 { 461 462 if ((ia->ia_flags & IFA_ROUTE) == 0) 463 return; 464 if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT)) 465 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); 466 else 467 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0); 468 ia->ia_flags &= ~IFA_ROUTE; 469 } 470 471 /* 472 * Initialize an interface's internet address 473 * and routing table entry. 474 */ 475 static int 476 in_ifinit(ifp, ia, sin, scrub) 477 register struct ifnet *ifp; 478 register struct in_ifaddr *ia; 479 struct sockaddr_in *sin; 480 int scrub; 481 { 482 register u_long i = ntohl(sin->sin_addr.s_addr); 483 struct sockaddr_in oldaddr; 484 int s = splimp(), flags = RTF_UP, error; 485 struct multi_kludge *mk; 486 487 oldaddr = ia->ia_addr; 488 ia->ia_addr = *sin; 489 /* 490 * Give the interface a chance to initialize 491 * if this is its first address, 492 * and to validate the address if necessary. 493 */ 494 if (ifp->if_ioctl && 495 (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia))) { 496 splx(s); 497 ia->ia_addr = oldaddr; 498 return (error); 499 } 500 splx(s); 501 if (scrub) { 502 ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr; 503 in_ifscrub(ifp, ia); 504 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr; 505 } 506 if (IN_CLASSA(i)) 507 ia->ia_netmask = IN_CLASSA_NET; 508 else if (IN_CLASSB(i)) 509 ia->ia_netmask = IN_CLASSB_NET; 510 else 511 ia->ia_netmask = IN_CLASSC_NET; 512 /* 513 * The subnet mask usually includes at least the standard network part, 514 * but may may be smaller in the case of supernetting. 515 * If it is set, we believe it. 516 */ 517 if (ia->ia_subnetmask == 0) { 518 ia->ia_subnetmask = ia->ia_netmask; 519 ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask); 520 } else 521 ia->ia_netmask &= ia->ia_subnetmask; 522 ia->ia_net = i & ia->ia_netmask; 523 ia->ia_subnet = i & ia->ia_subnetmask; 524 in_socktrim(&ia->ia_sockmask); 525 /* 526 * Add route for the network. 527 */ 528 ia->ia_ifa.ifa_metric = ifp->if_metric; 529 if (ifp->if_flags & IFF_BROADCAST) { 530 ia->ia_broadaddr.sin_addr.s_addr = 531 htonl(ia->ia_subnet | ~ia->ia_subnetmask); 532 ia->ia_netbroadcast.s_addr = 533 htonl(ia->ia_net | ~ ia->ia_netmask); 534 } else if (ifp->if_flags & IFF_LOOPBACK) { 535 ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr; 536 flags |= RTF_HOST; 537 } else if (ifp->if_flags & IFF_POINTOPOINT) { 538 if (ia->ia_dstaddr.sin_family != AF_INET) 539 return (0); 540 flags |= RTF_HOST; 541 } 542 if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD, flags)) == 0) 543 ia->ia_flags |= IFA_ROUTE; 544 545 LIST_INIT(&ia->ia_multiaddrs); 546 /* 547 * If the interface supports multicast, join the "all hosts" 548 * multicast group on that interface. 549 */ 550 if (ifp->if_flags & IFF_MULTICAST) { 551 struct in_addr addr; 552 553 /* 554 * Continuation of multicast address hack: 555 * If there was a multicast group list previously saved 556 * for this interface, then we re-attach it to the first 557 * address configured on the i/f. 558 */ 559 for(mk = in_mk.lh_first; mk; mk = mk->mk_entry.le_next) { 560 if(mk->mk_ifp == ifp) { 561 struct in_multi *inm; 562 563 for(inm = mk->mk_head.lh_first; inm; 564 inm = inm->inm_entry.le_next) { 565 IFAFREE(&inm->inm_ia->ia_ifa); 566 ia->ia_ifa.ifa_refcnt++; 567 inm->inm_ia = ia; 568 LIST_INSERT_HEAD(&ia->ia_multiaddrs, 569 inm, inm_entry); 570 } 571 LIST_REMOVE(mk, mk_entry); 572 free(mk, M_IPMADDR); 573 break; 574 } 575 } 576 577 addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP); 578 in_addmulti(&addr, ifp); 579 } 580 return (error); 581 } 582 583 584 /* 585 * Return 1 if the address might be a local broadcast address. 586 */ 587 int 588 in_broadcast(in, ifp) 589 struct in_addr in; 590 struct ifnet *ifp; 591 { 592 register struct ifaddr *ifa; 593 u_long t; 594 595 if (in.s_addr == INADDR_BROADCAST || 596 in.s_addr == INADDR_ANY) 597 return 1; 598 if ((ifp->if_flags & IFF_BROADCAST) == 0) 599 return 0; 600 t = ntohl(in.s_addr); 601 /* 602 * Look through the list of addresses for a match 603 * with a broadcast address. 604 */ 605 #define ia ((struct in_ifaddr *)ifa) 606 for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next) 607 if (ifa->ifa_addr->sa_family == AF_INET && 608 (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr || 609 in.s_addr == ia->ia_netbroadcast.s_addr || 610 /* 611 * Check for old-style (host 0) broadcast. 612 */ 613 t == ia->ia_subnet || t == ia->ia_net) && 614 /* 615 * Check for an all one subnetmask. These 616 * only exist when an interface gets a secondary 617 * address. 618 */ 619 ia->ia_subnetmask != (u_long)0xffffffff) 620 return 1; 621 return (0); 622 #undef ia 623 } 624 /* 625 * Add an address to the list of IP multicast addresses for a given interface. 626 */ 627 struct in_multi * 628 in_addmulti(ap, ifp) 629 register struct in_addr *ap; 630 register struct ifnet *ifp; 631 { 632 register struct in_multi *inm; 633 struct ifreq ifr; 634 struct in_ifaddr *ia; 635 int s = splnet(); 636 637 /* 638 * See if address already in list. 639 */ 640 IN_LOOKUP_MULTI(*ap, ifp, inm); 641 if (inm != NULL) { 642 /* 643 * Found it; just increment the reference count. 644 */ 645 ++inm->inm_refcount; 646 } 647 else { 648 /* 649 * New address; allocate a new multicast record 650 * and link it into the interface's multicast list. 651 */ 652 inm = (struct in_multi *)malloc(sizeof(*inm), 653 M_IPMADDR, M_NOWAIT); 654 if (inm == NULL) { 655 splx(s); 656 return (NULL); 657 } 658 inm->inm_addr = *ap; 659 inm->inm_ifp = ifp; 660 inm->inm_refcount = 1; 661 IFP_TO_IA(ifp, ia); 662 if (ia == NULL) { 663 free(inm, M_IPMADDR); 664 splx(s); 665 return (NULL); 666 } 667 inm->inm_ia = ia; 668 ia->ia_ifa.ifa_refcnt++; /* gain a reference */ 669 LIST_INSERT_HEAD(&ia->ia_multiaddrs, inm, inm_entry); 670 671 /* 672 * Ask the network driver to update its multicast reception 673 * filter appropriately for the new address. 674 */ 675 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_family = AF_INET; 676 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr = *ap; 677 if ((ifp->if_ioctl == NULL) || 678 (*ifp->if_ioctl)(ifp, SIOCADDMULTI,(caddr_t)&ifr) != 0) { 679 LIST_REMOVE(inm, inm_entry); 680 IFAFREE(&ia->ia_ifa); /* release reference */ 681 free(inm, M_IPMADDR); 682 splx(s); 683 return (NULL); 684 } 685 /* 686 * Let IGMP know that we have joined a new IP multicast group. 687 */ 688 igmp_joingroup(inm); 689 } 690 splx(s); 691 return (inm); 692 } 693 694 /* 695 * Delete a multicast address record. 696 */ 697 void 698 in_delmulti(inm) 699 register struct in_multi *inm; 700 { 701 struct ifreq ifr; 702 int s = splnet(); 703 704 if (--inm->inm_refcount == 0) { 705 /* 706 * No remaining claims to this record; let IGMP know that 707 * we are leaving the multicast group. 708 */ 709 igmp_leavegroup(inm); 710 /* 711 * Unlink from list. 712 */ 713 LIST_REMOVE(inm, inm_entry); 714 IFAFREE(&inm->inm_ia->ia_ifa); /* release reference */ 715 716 /* 717 * Notify the network driver to update its multicast reception 718 * filter. 719 */ 720 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_family = AF_INET; 721 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_addr = 722 inm->inm_addr; 723 (*inm->inm_ifp->if_ioctl)(inm->inm_ifp, SIOCDELMULTI, 724 (caddr_t)&ifr); 725 free(inm, M_IPMADDR); 726 } 727 splx(s); 728 } 729