1 /* 2 * Copyright (c) 1982, 1989, 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 * @(#)if_ethersubr.c 8.1 (Berkeley) 6/10/93 34 * $Id: if_ethersubr.c,v 1.4 1994/11/24 14:29:38 davidg Exp $ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/kernel.h> 40 #include <sys/malloc.h> 41 #include <sys/mbuf.h> 42 #include <sys/protosw.h> 43 #include <sys/socket.h> 44 #include <sys/ioctl.h> 45 #include <sys/errno.h> 46 #include <sys/syslog.h> 47 48 #include <machine/cpu.h> 49 50 #include <net/if.h> 51 #include <net/netisr.h> 52 #include <net/route.h> 53 #include <net/if_llc.h> 54 #include <net/if_dl.h> 55 #include <net/if_types.h> 56 57 #ifdef INET 58 #include <netinet/in.h> 59 #include <netinet/in_var.h> 60 #endif 61 #include <netinet/if_ether.h> 62 63 #ifdef NS 64 #include <netns/ns.h> 65 #include <netns/ns_if.h> 66 #endif 67 68 #ifdef ISO 69 #include <netiso/argo_debug.h> 70 #include <netiso/iso.h> 71 #include <netiso/iso_var.h> 72 #include <netiso/iso_snpac.h> 73 #endif 74 75 #ifdef LLC 76 #include <netccitt/dll.h> 77 #include <netccitt/llc_var.h> 78 #endif 79 80 #if defined(LLC) && defined(CCITT) 81 extern struct ifqueue pkintrq; 82 #endif 83 84 u_char etherbroadcastaddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 85 extern struct ifnet loif; 86 #define senderr(e) { error = (e); goto bad;} 87 88 /* 89 * Ethernet output routine. 90 * Encapsulate a packet of type family for the local net. 91 * Use trailer local net encapsulation if enough data in first 92 * packet leaves a multiple of 512 bytes of data in remainder. 93 * Assumes that ifp is actually pointer to arpcom structure. 94 */ 95 int 96 ether_output(ifp, m0, dst, rt0) 97 register struct ifnet *ifp; 98 struct mbuf *m0; 99 struct sockaddr *dst; 100 struct rtentry *rt0; 101 { 102 short type; 103 int s, error = 0; 104 u_char edst[6]; 105 register struct mbuf *m = m0; 106 register struct rtentry *rt; 107 struct mbuf *mcopy = (struct mbuf *)0; 108 register struct ether_header *eh; 109 int off, len = m->m_pkthdr.len; 110 struct arpcom *ac = (struct arpcom *)ifp; 111 112 if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) 113 senderr(ENETDOWN); 114 ifp->if_lastchange = time; 115 if (rt = rt0) { 116 if ((rt->rt_flags & RTF_UP) == 0) { 117 if (rt0 = rt = rtalloc1(dst, 1, 0UL)) 118 rt->rt_refcnt--; 119 else 120 senderr(EHOSTUNREACH); 121 } 122 if (rt->rt_flags & RTF_GATEWAY) { 123 if (rt->rt_gwroute == 0) 124 goto lookup; 125 if (((rt = rt->rt_gwroute)->rt_flags & RTF_UP) == 0) { 126 rtfree(rt); rt = rt0; 127 lookup: rt->rt_gwroute = rtalloc1(rt->rt_gateway, 1, 128 0UL); 129 if ((rt = rt->rt_gwroute) == 0) 130 senderr(EHOSTUNREACH); 131 } 132 } 133 if (rt->rt_flags & RTF_REJECT) 134 if (rt->rt_rmx.rmx_expire == 0 || 135 time.tv_sec < rt->rt_rmx.rmx_expire) 136 senderr(rt == rt0 ? EHOSTDOWN : EHOSTUNREACH); 137 } 138 switch (dst->sa_family) { 139 140 #ifdef INET 141 case AF_INET: 142 if (!arpresolve(ac, rt, m, dst, edst, rt0)) 143 return (0); /* if not yet resolved */ 144 /* If broadcasting on a simplex interface, loopback a copy */ 145 if ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_SIMPLEX)) 146 mcopy = m_copy(m, 0, (int)M_COPYALL); 147 off = m->m_pkthdr.len - m->m_len; 148 type = ETHERTYPE_IP; 149 break; 150 #endif 151 #ifdef NS 152 case AF_NS: 153 type = ETHERTYPE_NS; 154 bcopy((caddr_t)&(((struct sockaddr_ns *)dst)->sns_addr.x_host), 155 (caddr_t)edst, sizeof (edst)); 156 if (!bcmp((caddr_t)edst, (caddr_t)&ns_thishost, sizeof(edst))) 157 return (looutput(ifp, m, dst, rt)); 158 /* If broadcasting on a simplex interface, loopback a copy */ 159 if ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_SIMPLEX)) 160 mcopy = m_copy(m, 0, (int)M_COPYALL); 161 break; 162 #endif 163 #ifdef ISO 164 case AF_ISO: { 165 int snpalen; 166 struct llc *l; 167 register struct sockaddr_dl *sdl; 168 169 if (rt && (sdl = (struct sockaddr_dl *)rt->rt_gateway) && 170 sdl->sdl_family == AF_LINK && sdl->sdl_alen > 0) { 171 bcopy(LLADDR(sdl), (caddr_t)edst, sizeof(edst)); 172 } else if (error = 173 iso_snparesolve(ifp, (struct sockaddr_iso *)dst, 174 (char *)edst, &snpalen)) 175 goto bad; /* Not Resolved */ 176 /* If broadcasting on a simplex interface, loopback a copy */ 177 if (*edst & 1) 178 m->m_flags |= (M_BCAST|M_MCAST); 179 if ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_SIMPLEX) && 180 (mcopy = m_copy(m, 0, (int)M_COPYALL))) { 181 M_PREPEND(mcopy, sizeof (*eh), M_DONTWAIT); 182 if (mcopy) { 183 eh = mtod(mcopy, struct ether_header *); 184 bcopy((caddr_t)edst, 185 (caddr_t)eh->ether_dhost, sizeof (edst)); 186 bcopy((caddr_t)ac->ac_enaddr, 187 (caddr_t)eh->ether_shost, sizeof (edst)); 188 } 189 } 190 M_PREPEND(m, 3, M_DONTWAIT); 191 if (m == NULL) 192 return (0); 193 type = m->m_pkthdr.len; 194 l = mtod(m, struct llc *); 195 l->llc_dsap = l->llc_ssap = LLC_ISO_LSAP; 196 l->llc_control = LLC_UI; 197 len += 3; 198 IFDEBUG(D_ETHER) 199 int i; 200 printf("unoutput: sending pkt to: "); 201 for (i=0; i<6; i++) 202 printf("%x ", edst[i] & 0xff); 203 printf("\n"); 204 ENDDEBUG 205 } break; 206 #endif /* ISO */ 207 #ifdef LLC 208 /* case AF_NSAP: */ 209 case AF_CCITT: { 210 register struct sockaddr_dl *sdl = 211 (struct sockaddr_dl *) rt -> rt_gateway; 212 213 if (sdl && sdl->sdl_family == AF_LINK 214 && sdl->sdl_alen > 0) { 215 bcopy(LLADDR(sdl), (char *)edst, 216 sizeof(edst)); 217 } else goto bad; /* Not a link interface ? Funny ... */ 218 if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1) && 219 (mcopy = m_copy(m, 0, (int)M_COPYALL))) { 220 M_PREPEND(mcopy, sizeof (*eh), M_DONTWAIT); 221 if (mcopy) { 222 eh = mtod(mcopy, struct ether_header *); 223 bcopy((caddr_t)edst, 224 (caddr_t)eh->ether_dhost, sizeof (edst)); 225 bcopy((caddr_t)ac->ac_enaddr, 226 (caddr_t)eh->ether_shost, sizeof (edst)); 227 } 228 } 229 type = m->m_pkthdr.len; 230 #ifdef LLC_DEBUG 231 { 232 int i; 233 register struct llc *l = mtod(m, struct llc *); 234 235 printf("ether_output: sending LLC2 pkt to: "); 236 for (i=0; i<6; i++) 237 printf("%x ", edst[i] & 0xff); 238 printf(" len 0x%x dsap 0x%x ssap 0x%x control 0x%x\n", 239 type & 0xff, l->llc_dsap & 0xff, l->llc_ssap &0xff, 240 l->llc_control & 0xff); 241 242 } 243 #endif /* LLC_DEBUG */ 244 } break; 245 #endif /* LLC */ 246 247 case AF_UNSPEC: 248 eh = (struct ether_header *)dst->sa_data; 249 bcopy((caddr_t)eh->ether_dhost, (caddr_t)edst, sizeof (edst)); 250 type = eh->ether_type; 251 break; 252 253 default: 254 printf("%s%d: can't handle af%d\n", ifp->if_name, ifp->if_unit, 255 dst->sa_family); 256 senderr(EAFNOSUPPORT); 257 } 258 259 260 if (mcopy) 261 (void) looutput(ifp, mcopy, dst, rt); 262 /* 263 * Add local net header. If no space in first mbuf, 264 * allocate another. 265 */ 266 M_PREPEND(m, sizeof (struct ether_header), M_DONTWAIT); 267 if (m == 0) 268 senderr(ENOBUFS); 269 eh = mtod(m, struct ether_header *); 270 type = htons((u_short)type); 271 bcopy((caddr_t)&type,(caddr_t)&eh->ether_type, 272 sizeof(eh->ether_type)); 273 bcopy((caddr_t)edst, (caddr_t)eh->ether_dhost, sizeof (edst)); 274 bcopy((caddr_t)ac->ac_enaddr, (caddr_t)eh->ether_shost, 275 sizeof(eh->ether_shost)); 276 s = splimp(); 277 /* 278 * Queue message on interface, and start output if interface 279 * not yet active. 280 */ 281 if (IF_QFULL(&ifp->if_snd)) { 282 IF_DROP(&ifp->if_snd); 283 splx(s); 284 senderr(ENOBUFS); 285 } 286 IF_ENQUEUE(&ifp->if_snd, m); 287 if ((ifp->if_flags & IFF_OACTIVE) == 0) 288 (*ifp->if_start)(ifp); 289 splx(s); 290 ifp->if_obytes += len + sizeof (struct ether_header); 291 if (m->m_flags & M_MCAST) 292 ifp->if_omcasts++; 293 return (error); 294 295 bad: 296 if (m) 297 m_freem(m); 298 return (error); 299 } 300 301 /* 302 * Process a received Ethernet packet; 303 * the packet is in the mbuf chain m without 304 * the ether header, which is provided separately. 305 */ 306 void 307 ether_input(ifp, eh, m) 308 struct ifnet *ifp; 309 register struct ether_header *eh; 310 struct mbuf *m; 311 { 312 register struct ifqueue *inq; 313 register struct llc *l; 314 struct arpcom *ac = (struct arpcom *)ifp; 315 u_short ether_type; 316 int s; 317 318 if ((ifp->if_flags & IFF_UP) == 0) { 319 m_freem(m); 320 return; 321 } 322 ifp->if_lastchange = time; 323 ifp->if_ibytes += m->m_pkthdr.len + sizeof (*eh); 324 if (bcmp((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost, 325 sizeof(etherbroadcastaddr)) == 0) 326 m->m_flags |= M_BCAST; 327 else if (eh->ether_dhost[0] & 1) 328 m->m_flags |= M_MCAST; 329 if (m->m_flags & (M_BCAST|M_MCAST)) 330 ifp->if_imcasts++; 331 332 ether_type = ntohs(eh->ether_type); 333 334 switch (ether_type) { 335 #ifdef INET 336 case ETHERTYPE_IP: 337 schednetisr(NETISR_IP); 338 inq = &ipintrq; 339 break; 340 341 case ETHERTYPE_ARP: 342 schednetisr(NETISR_ARP); 343 inq = &arpintrq; 344 break; 345 #endif 346 #ifdef NS 347 case ETHERTYPE_NS: 348 schednetisr(NETISR_NS); 349 inq = &nsintrq; 350 break; 351 352 #endif 353 default: 354 #if defined (ISO) || defined (LLC) 355 if (ether_type > ETHERMTU) 356 goto dropanyway; 357 l = mtod(m, struct llc *); 358 switch (l->llc_dsap) { 359 #ifdef ISO 360 case LLC_ISO_LSAP: 361 switch (l->llc_control) { 362 case LLC_UI: 363 /* LLC_UI_P forbidden in class 1 service */ 364 if ((l->llc_dsap == LLC_ISO_LSAP) && 365 (l->llc_ssap == LLC_ISO_LSAP)) { 366 /* LSAP for ISO */ 367 if (m->m_pkthdr.len > ether_type) 368 m_adj(m, ether_type - m->m_pkthdr.len); 369 m->m_data += 3; /* XXX */ 370 m->m_len -= 3; /* XXX */ 371 m->m_pkthdr.len -= 3; /* XXX */ 372 M_PREPEND(m, sizeof *eh, M_DONTWAIT); 373 if (m == 0) 374 return; 375 *mtod(m, struct ether_header *) = *eh; 376 IFDEBUG(D_ETHER) 377 printf("clnp packet"); 378 ENDDEBUG 379 schednetisr(NETISR_ISO); 380 inq = &clnlintrq; 381 break; 382 } 383 goto dropanyway; 384 385 case LLC_XID: 386 case LLC_XID_P: 387 if(m->m_len < 6) 388 goto dropanyway; 389 l->llc_window = 0; 390 l->llc_fid = 9; 391 l->llc_class = 1; 392 l->llc_dsap = l->llc_ssap = 0; 393 /* Fall through to */ 394 case LLC_TEST: 395 case LLC_TEST_P: 396 { 397 struct sockaddr sa; 398 register struct ether_header *eh2; 399 int i; 400 u_char c = l->llc_dsap; 401 402 l->llc_dsap = l->llc_ssap; 403 l->llc_ssap = c; 404 if (m->m_flags & (M_BCAST | M_MCAST)) 405 bcopy((caddr_t)ac->ac_enaddr, 406 (caddr_t)eh->ether_dhost, 6); 407 sa.sa_family = AF_UNSPEC; 408 sa.sa_len = sizeof(sa); 409 eh2 = (struct ether_header *)sa.sa_data; 410 for (i = 0; i < 6; i++) { 411 eh2->ether_shost[i] = c = eh->ether_dhost[i]; 412 eh2->ether_dhost[i] = 413 eh->ether_dhost[i] = eh->ether_shost[i]; 414 eh->ether_shost[i] = c; 415 } 416 ifp->if_output(ifp, m, &sa, NULL); 417 return; 418 } 419 default: 420 m_freem(m); 421 return; 422 } 423 break; 424 #endif /* ISO */ 425 #ifdef LLC 426 case LLC_X25_LSAP: 427 { 428 if (m->m_pkthdr.len > ether_type) 429 m_adj(m, ether_type - m->m_pkthdr.len); 430 M_PREPEND(m, sizeof(struct sdl_hdr) , M_DONTWAIT); 431 if (m == 0) 432 return; 433 if ( !sdl_sethdrif(ifp, eh->ether_shost, LLC_X25_LSAP, 434 eh->ether_dhost, LLC_X25_LSAP, 6, 435 mtod(m, struct sdl_hdr *))) 436 panic("ETHER cons addr failure"); 437 mtod(m, struct sdl_hdr *)->sdlhdr_len = ether_type; 438 #ifdef LLC_DEBUG 439 printf("llc packet\n"); 440 #endif /* LLC_DEBUG */ 441 schednetisr(NETISR_CCITT); 442 inq = &llcintrq; 443 break; 444 } 445 #endif /* LLC */ 446 dropanyway: 447 default: 448 m_freem(m); 449 return; 450 } 451 #else /* ISO || LLC */ 452 m_freem(m); 453 return; 454 #endif /* ISO || LLC */ 455 } 456 457 s = splimp(); 458 if (IF_QFULL(inq)) { 459 IF_DROP(inq); 460 m_freem(m); 461 } else 462 IF_ENQUEUE(inq, m); 463 splx(s); 464 } 465 466 /* 467 * Convert Ethernet address to printable (loggable) representation. 468 */ 469 static char digits[] = "0123456789abcdef"; 470 char * 471 ether_sprintf(ap) 472 register u_char *ap; 473 { 474 register i; 475 static char etherbuf[18]; 476 register char *cp = etherbuf; 477 478 for (i = 0; i < 6; i++) { 479 *cp++ = digits[*ap >> 4]; 480 *cp++ = digits[*ap++ & 0xf]; 481 *cp++ = ':'; 482 } 483 *--cp = 0; 484 return (etherbuf); 485 } 486 487 /* 488 * Perform common duties while attaching to interface list 489 */ 490 void 491 ether_ifattach(ifp) 492 register struct ifnet *ifp; 493 { 494 register struct ifaddr *ifa; 495 register struct sockaddr_dl *sdl; 496 497 ifp->if_type = IFT_ETHER; 498 ifp->if_addrlen = 6; 499 ifp->if_hdrlen = 14; 500 ifp->if_mtu = ETHERMTU; 501 for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next) 502 if ((sdl = (struct sockaddr_dl *)ifa->ifa_addr) && 503 sdl->sdl_family == AF_LINK) { 504 sdl->sdl_type = IFT_ETHER; 505 sdl->sdl_alen = ifp->if_addrlen; 506 bcopy((caddr_t)((struct arpcom *)ifp)->ac_enaddr, 507 LLADDR(sdl), ifp->if_addrlen); 508 break; 509 } 510 } 511 512 u_char ether_ipmulticast_min[6] = { 0x01, 0x00, 0x5e, 0x00, 0x00, 0x00 }; 513 u_char ether_ipmulticast_max[6] = { 0x01, 0x00, 0x5e, 0x7f, 0xff, 0xff }; 514 /* 515 * Add an Ethernet multicast address or range of addresses to the list for a 516 * given interface. 517 */ 518 int 519 ether_addmulti(ifr, ac) 520 struct ifreq *ifr; 521 register struct arpcom *ac; 522 { 523 register struct ether_multi *enm; 524 struct sockaddr_in *sin; 525 u_char addrlo[6]; 526 u_char addrhi[6]; 527 int s = splimp(); 528 529 switch (ifr->ifr_addr.sa_family) { 530 531 case AF_UNSPEC: 532 bcopy(ifr->ifr_addr.sa_data, addrlo, 6); 533 bcopy(addrlo, addrhi, 6); 534 break; 535 536 #ifdef INET 537 case AF_INET: 538 sin = (struct sockaddr_in *)&(ifr->ifr_addr); 539 if (sin->sin_addr.s_addr == INADDR_ANY) { 540 /* 541 * An IP address of INADDR_ANY means listen to all 542 * of the Ethernet multicast addresses used for IP. 543 * (This is for the sake of IP multicast routers.) 544 */ 545 bcopy(ether_ipmulticast_min, addrlo, 6); 546 bcopy(ether_ipmulticast_max, addrhi, 6); 547 } 548 else { 549 ETHER_MAP_IP_MULTICAST(&sin->sin_addr, addrlo); 550 bcopy(addrlo, addrhi, 6); 551 } 552 break; 553 #endif 554 555 default: 556 splx(s); 557 return (EAFNOSUPPORT); 558 } 559 560 /* 561 * Verify that we have valid Ethernet multicast addresses. 562 */ 563 if ((addrlo[0] & 0x01) != 1 || (addrhi[0] & 0x01) != 1) { 564 splx(s); 565 return (EINVAL); 566 } 567 /* 568 * See if the address range is already in the list. 569 */ 570 ETHER_LOOKUP_MULTI(addrlo, addrhi, ac, enm); 571 if (enm != NULL) { 572 /* 573 * Found it; just increment the reference count. 574 */ 575 ++enm->enm_refcount; 576 splx(s); 577 return (0); 578 } 579 /* 580 * New address or range; malloc a new multicast record 581 * and link it into the interface's multicast list. 582 */ 583 enm = (struct ether_multi *)malloc(sizeof(*enm), M_IFMADDR, M_NOWAIT); 584 if (enm == NULL) { 585 splx(s); 586 return (ENOBUFS); 587 } 588 bcopy(addrlo, enm->enm_addrlo, 6); 589 bcopy(addrhi, enm->enm_addrhi, 6); 590 enm->enm_ac = ac; 591 enm->enm_refcount = 1; 592 enm->enm_next = ac->ac_multiaddrs; 593 ac->ac_multiaddrs = enm; 594 ac->ac_multicnt++; 595 splx(s); 596 /* 597 * Return ENETRESET to inform the driver that the list has changed 598 * and its reception filter should be adjusted accordingly. 599 */ 600 return (ENETRESET); 601 } 602 603 /* 604 * Delete a multicast address record. 605 */ 606 int 607 ether_delmulti(ifr, ac) 608 struct ifreq *ifr; 609 register struct arpcom *ac; 610 { 611 register struct ether_multi *enm; 612 register struct ether_multi **p; 613 struct sockaddr_in *sin; 614 u_char addrlo[6]; 615 u_char addrhi[6]; 616 int s = splimp(); 617 618 switch (ifr->ifr_addr.sa_family) { 619 620 case AF_UNSPEC: 621 bcopy(ifr->ifr_addr.sa_data, addrlo, 6); 622 bcopy(addrlo, addrhi, 6); 623 break; 624 625 #ifdef INET 626 case AF_INET: 627 sin = (struct sockaddr_in *)&(ifr->ifr_addr); 628 if (sin->sin_addr.s_addr == INADDR_ANY) { 629 /* 630 * An IP address of INADDR_ANY means stop listening 631 * to the range of Ethernet multicast addresses used 632 * for IP. 633 */ 634 bcopy(ether_ipmulticast_min, addrlo, 6); 635 bcopy(ether_ipmulticast_max, addrhi, 6); 636 } 637 else { 638 ETHER_MAP_IP_MULTICAST(&sin->sin_addr, addrlo); 639 bcopy(addrlo, addrhi, 6); 640 } 641 break; 642 #endif 643 644 default: 645 splx(s); 646 return (EAFNOSUPPORT); 647 } 648 649 /* 650 * Look up the address in our list. 651 */ 652 ETHER_LOOKUP_MULTI(addrlo, addrhi, ac, enm); 653 if (enm == NULL) { 654 splx(s); 655 return (ENXIO); 656 } 657 if (--enm->enm_refcount != 0) { 658 /* 659 * Still some claims to this record. 660 */ 661 splx(s); 662 return (0); 663 } 664 /* 665 * No remaining claims to this record; unlink and free it. 666 */ 667 for (p = &enm->enm_ac->ac_multiaddrs; 668 *p != enm; 669 p = &(*p)->enm_next) 670 continue; 671 *p = (*p)->enm_next; 672 free(enm, M_IFMADDR); 673 ac->ac_multicnt--; 674 splx(s); 675 /* 676 * Return ENETRESET to inform the driver that the list has changed 677 * and its reception filter should be adjusted accordingly. 678 */ 679 return (ENETRESET); 680 } 681