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 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)if_ethersubr.c 8.1 (Berkeley) 6/10/93 30 * $FreeBSD$ 31 */ 32 33 #include "opt_atalk.h" 34 #include "opt_inet.h" 35 #include "opt_inet6.h" 36 #include "opt_ipx.h" 37 #include "opt_route.h" 38 #include "opt_netgraph.h" 39 #include "opt_carp.h" 40 #include "opt_mbuf_profiling.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/kernel.h> 45 #include <sys/lock.h> 46 #include <sys/malloc.h> 47 #include <sys/module.h> 48 #include <sys/mbuf.h> 49 #include <sys/random.h> 50 #include <sys/rwlock.h> 51 #include <sys/socket.h> 52 #include <sys/sockio.h> 53 #include <sys/sysctl.h> 54 #include <sys/vimage.h> 55 56 #include <net/if.h> 57 #include <net/if_arp.h> 58 #include <net/netisr.h> 59 #include <net/route.h> 60 #include <net/if_llc.h> 61 #include <net/if_dl.h> 62 #include <net/if_types.h> 63 #include <net/bpf.h> 64 #include <net/ethernet.h> 65 #include <net/if_bridgevar.h> 66 #include <net/if_vlan_var.h> 67 #include <net/if_llatbl.h> 68 #include <net/pf_mtag.h> 69 #include <net/vnet.h> 70 71 #if defined(INET) || defined(INET6) 72 #include <netinet/in.h> 73 #include <netinet/in_var.h> 74 #include <netinet/if_ether.h> 75 #include <netinet/ip_fw.h> 76 #include <netinet/ip_dummynet.h> 77 #include <netinet/vinet.h> 78 #endif 79 #ifdef INET6 80 #include <netinet6/nd6.h> 81 #endif 82 83 #ifdef DEV_CARP 84 #include <netinet/ip_carp.h> 85 #endif 86 87 #ifdef IPX 88 #include <netipx/ipx.h> 89 #include <netipx/ipx_if.h> 90 #endif 91 92 int (*ef_inputp)(struct ifnet*, struct ether_header *eh, struct mbuf *m); 93 int (*ef_outputp)(struct ifnet *ifp, struct mbuf **mp, 94 struct sockaddr *dst, short *tp, int *hlen); 95 96 #ifdef NETATALK 97 #include <netatalk/at.h> 98 #include <netatalk/at_var.h> 99 #include <netatalk/at_extern.h> 100 101 #define llc_snap_org_code llc_un.type_snap.org_code 102 #define llc_snap_ether_type llc_un.type_snap.ether_type 103 104 extern u_char at_org_code[3]; 105 extern u_char aarp_org_code[3]; 106 #endif /* NETATALK */ 107 108 #include <security/mac/mac_framework.h> 109 110 #ifdef CTASSERT 111 CTASSERT(sizeof (struct ether_header) == ETHER_ADDR_LEN * 2 + 2); 112 CTASSERT(sizeof (struct ether_addr) == ETHER_ADDR_LEN); 113 #endif 114 115 /* netgraph node hooks for ng_ether(4) */ 116 void (*ng_ether_input_p)(struct ifnet *ifp, struct mbuf **mp); 117 void (*ng_ether_input_orphan_p)(struct ifnet *ifp, struct mbuf *m); 118 int (*ng_ether_output_p)(struct ifnet *ifp, struct mbuf **mp); 119 void (*ng_ether_attach_p)(struct ifnet *ifp); 120 void (*ng_ether_detach_p)(struct ifnet *ifp); 121 122 void (*vlan_input_p)(struct ifnet *, struct mbuf *); 123 124 /* if_bridge(4) support */ 125 struct mbuf *(*bridge_input_p)(struct ifnet *, struct mbuf *); 126 int (*bridge_output_p)(struct ifnet *, struct mbuf *, 127 struct sockaddr *, struct rtentry *); 128 void (*bridge_dn_p)(struct mbuf *, struct ifnet *); 129 130 /* if_lagg(4) support */ 131 struct mbuf *(*lagg_input_p)(struct ifnet *, struct mbuf *); 132 133 static const u_char etherbroadcastaddr[ETHER_ADDR_LEN] = 134 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 135 136 static int ether_resolvemulti(struct ifnet *, struct sockaddr **, 137 struct sockaddr *); 138 139 /* XXX: should be in an arp support file, not here */ 140 MALLOC_DEFINE(M_ARPCOM, "arpcom", "802.* interface internals"); 141 142 #define ETHER_IS_BROADCAST(addr) \ 143 (bcmp(etherbroadcastaddr, (addr), ETHER_ADDR_LEN) == 0) 144 145 #define senderr(e) do { error = (e); goto bad;} while (0) 146 147 #if defined(INET) || defined(INET6) 148 int 149 ether_ipfw_chk(struct mbuf **m0, struct ifnet *dst, 150 struct ip_fw **rule, int shared); 151 #ifdef VIMAGE_GLOBALS 152 static int ether_ipfw; 153 #endif 154 #endif 155 156 157 /* 158 * Ethernet output routine. 159 * Encapsulate a packet of type family for the local net. 160 * Use trailer local net encapsulation if enough data in first 161 * packet leaves a multiple of 512 bytes of data in remainder. 162 */ 163 int 164 ether_output(struct ifnet *ifp, struct mbuf *m, 165 struct sockaddr *dst, struct route *ro) 166 { 167 short type; 168 int error = 0, hdrcmplt = 0; 169 u_char esrc[ETHER_ADDR_LEN], edst[ETHER_ADDR_LEN]; 170 struct llentry *lle = NULL; 171 struct rtentry *rt0 = NULL; 172 struct ether_header *eh; 173 struct pf_mtag *t; 174 int loop_copy = 1; 175 int hlen; /* link layer header length */ 176 177 if (ro != NULL) { 178 lle = ro->ro_lle; 179 rt0 = ro->ro_rt; 180 } 181 #ifdef MAC 182 error = mac_ifnet_check_transmit(ifp, m); 183 if (error) 184 senderr(error); 185 #endif 186 187 M_PROFILE(m); 188 if (ifp->if_flags & IFF_MONITOR) 189 senderr(ENETDOWN); 190 if (!((ifp->if_flags & IFF_UP) && 191 (ifp->if_drv_flags & IFF_DRV_RUNNING))) 192 senderr(ENETDOWN); 193 194 hlen = ETHER_HDR_LEN; 195 switch (dst->sa_family) { 196 #ifdef INET 197 case AF_INET: 198 if (lle != NULL && (lle->la_flags & LLE_VALID)) 199 memcpy(edst, &lle->ll_addr.mac16, sizeof(edst)); 200 else 201 error = arpresolve(ifp, rt0, m, dst, edst, &lle); 202 if (error) 203 return (error == EWOULDBLOCK ? 0 : error); 204 type = htons(ETHERTYPE_IP); 205 break; 206 case AF_ARP: 207 { 208 struct arphdr *ah; 209 ah = mtod(m, struct arphdr *); 210 ah->ar_hrd = htons(ARPHRD_ETHER); 211 212 loop_copy = 0; /* if this is for us, don't do it */ 213 214 switch(ntohs(ah->ar_op)) { 215 case ARPOP_REVREQUEST: 216 case ARPOP_REVREPLY: 217 type = htons(ETHERTYPE_REVARP); 218 break; 219 case ARPOP_REQUEST: 220 case ARPOP_REPLY: 221 default: 222 type = htons(ETHERTYPE_ARP); 223 break; 224 } 225 226 if (m->m_flags & M_BCAST) 227 bcopy(ifp->if_broadcastaddr, edst, ETHER_ADDR_LEN); 228 else 229 bcopy(ar_tha(ah), edst, ETHER_ADDR_LEN); 230 231 } 232 break; 233 #endif 234 #ifdef INET6 235 case AF_INET6: 236 if (lle != NULL && (lle->la_flags & LLE_VALID)) 237 memcpy(edst, &lle->ll_addr.mac16, sizeof(edst)); 238 else 239 error = nd6_storelladdr(ifp, m, dst, (u_char *)edst, &lle); 240 if (error) 241 return error; 242 type = htons(ETHERTYPE_IPV6); 243 break; 244 #endif 245 #ifdef IPX 246 case AF_IPX: 247 if (ef_outputp) { 248 error = ef_outputp(ifp, &m, dst, &type, &hlen); 249 if (error) 250 goto bad; 251 } else 252 type = htons(ETHERTYPE_IPX); 253 bcopy((caddr_t)&(((struct sockaddr_ipx *)dst)->sipx_addr.x_host), 254 (caddr_t)edst, sizeof (edst)); 255 break; 256 #endif 257 #ifdef NETATALK 258 case AF_APPLETALK: 259 { 260 struct at_ifaddr *aa; 261 262 if ((aa = at_ifawithnet((struct sockaddr_at *)dst)) == NULL) 263 senderr(EHOSTUNREACH); /* XXX */ 264 if (!aarpresolve(ifp, m, (struct sockaddr_at *)dst, edst)) 265 return (0); 266 /* 267 * In the phase 2 case, need to prepend an mbuf for the llc header. 268 */ 269 if ( aa->aa_flags & AFA_PHASE2 ) { 270 struct llc llc; 271 272 M_PREPEND(m, LLC_SNAPFRAMELEN, M_DONTWAIT); 273 if (m == NULL) 274 senderr(ENOBUFS); 275 llc.llc_dsap = llc.llc_ssap = LLC_SNAP_LSAP; 276 llc.llc_control = LLC_UI; 277 bcopy(at_org_code, llc.llc_snap_org_code, sizeof(at_org_code)); 278 llc.llc_snap_ether_type = htons( ETHERTYPE_AT ); 279 bcopy(&llc, mtod(m, caddr_t), LLC_SNAPFRAMELEN); 280 type = htons(m->m_pkthdr.len); 281 hlen = LLC_SNAPFRAMELEN + ETHER_HDR_LEN; 282 } else { 283 type = htons(ETHERTYPE_AT); 284 } 285 break; 286 } 287 #endif /* NETATALK */ 288 289 case pseudo_AF_HDRCMPLT: 290 hdrcmplt = 1; 291 eh = (struct ether_header *)dst->sa_data; 292 (void)memcpy(esrc, eh->ether_shost, sizeof (esrc)); 293 /* FALLTHROUGH */ 294 295 case AF_UNSPEC: 296 loop_copy = 0; /* if this is for us, don't do it */ 297 eh = (struct ether_header *)dst->sa_data; 298 (void)memcpy(edst, eh->ether_dhost, sizeof (edst)); 299 type = eh->ether_type; 300 break; 301 302 default: 303 if_printf(ifp, "can't handle af%d\n", dst->sa_family); 304 senderr(EAFNOSUPPORT); 305 } 306 307 if (lle != NULL && (lle->la_flags & LLE_IFADDR)) { 308 int csum_flags = 0; 309 if (m->m_pkthdr.csum_flags & CSUM_IP) 310 csum_flags |= (CSUM_IP_CHECKED|CSUM_IP_VALID); 311 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) 312 csum_flags |= (CSUM_DATA_VALID|CSUM_PSEUDO_HDR); 313 if (m->m_pkthdr.csum_flags & CSUM_SCTP) 314 csum_flags |= CSUM_SCTP_VALID; 315 m->m_pkthdr.csum_flags |= csum_flags; 316 m->m_pkthdr.csum_data = 0xffff; 317 return (if_simloop(ifp, m, dst->sa_family, 0)); 318 } 319 320 /* 321 * Add local net header. If no space in first mbuf, 322 * allocate another. 323 */ 324 M_PREPEND(m, ETHER_HDR_LEN, M_DONTWAIT); 325 if (m == NULL) 326 senderr(ENOBUFS); 327 eh = mtod(m, struct ether_header *); 328 (void)memcpy(&eh->ether_type, &type, 329 sizeof(eh->ether_type)); 330 (void)memcpy(eh->ether_dhost, edst, sizeof (edst)); 331 if (hdrcmplt) 332 (void)memcpy(eh->ether_shost, esrc, 333 sizeof(eh->ether_shost)); 334 else 335 (void)memcpy(eh->ether_shost, IF_LLADDR(ifp), 336 sizeof(eh->ether_shost)); 337 338 /* 339 * If a simplex interface, and the packet is being sent to our 340 * Ethernet address or a broadcast address, loopback a copy. 341 * XXX To make a simplex device behave exactly like a duplex 342 * device, we should copy in the case of sending to our own 343 * ethernet address (thus letting the original actually appear 344 * on the wire). However, we don't do that here for security 345 * reasons and compatibility with the original behavior. 346 */ 347 if ((ifp->if_flags & IFF_SIMPLEX) && loop_copy && 348 ((t = pf_find_mtag(m)) == NULL || !t->routed)) { 349 int csum_flags = 0; 350 351 if (m->m_pkthdr.csum_flags & CSUM_IP) 352 csum_flags |= (CSUM_IP_CHECKED|CSUM_IP_VALID); 353 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) 354 csum_flags |= (CSUM_DATA_VALID|CSUM_PSEUDO_HDR); 355 if (m->m_pkthdr.csum_flags & CSUM_SCTP) 356 csum_flags |= CSUM_SCTP_VALID; 357 358 if (m->m_flags & M_BCAST) { 359 struct mbuf *n; 360 361 /* 362 * Because if_simloop() modifies the packet, we need a 363 * writable copy through m_dup() instead of a readonly 364 * one as m_copy[m] would give us. The alternative would 365 * be to modify if_simloop() to handle the readonly mbuf, 366 * but performancewise it is mostly equivalent (trading 367 * extra data copying vs. extra locking). 368 * 369 * XXX This is a local workaround. A number of less 370 * often used kernel parts suffer from the same bug. 371 * See PR kern/105943 for a proposed general solution. 372 */ 373 if ((n = m_dup(m, M_DONTWAIT)) != NULL) { 374 n->m_pkthdr.csum_flags |= csum_flags; 375 if (csum_flags & CSUM_DATA_VALID) 376 n->m_pkthdr.csum_data = 0xffff; 377 (void)if_simloop(ifp, n, dst->sa_family, hlen); 378 } else 379 ifp->if_iqdrops++; 380 } else if (bcmp(eh->ether_dhost, eh->ether_shost, 381 ETHER_ADDR_LEN) == 0) { 382 m->m_pkthdr.csum_flags |= csum_flags; 383 if (csum_flags & CSUM_DATA_VALID) 384 m->m_pkthdr.csum_data = 0xffff; 385 (void) if_simloop(ifp, m, dst->sa_family, hlen); 386 return (0); /* XXX */ 387 } 388 } 389 390 /* 391 * Bridges require special output handling. 392 */ 393 if (ifp->if_bridge) { 394 BRIDGE_OUTPUT(ifp, m, error); 395 return (error); 396 } 397 398 #ifdef DEV_CARP 399 if (ifp->if_carp && 400 (error = carp_output(ifp, m, dst, NULL))) 401 goto bad; 402 #endif 403 404 /* Handle ng_ether(4) processing, if any */ 405 if (IFP2AC(ifp)->ac_netgraph != NULL) { 406 KASSERT(ng_ether_output_p != NULL, 407 ("ng_ether_output_p is NULL")); 408 if ((error = (*ng_ether_output_p)(ifp, &m)) != 0) { 409 bad: if (m != NULL) 410 m_freem(m); 411 return (error); 412 } 413 if (m == NULL) 414 return (0); 415 } 416 417 /* Continue with link-layer output */ 418 return ether_output_frame(ifp, m); 419 } 420 421 /* 422 * Ethernet link layer output routine to send a raw frame to the device. 423 * 424 * This assumes that the 14 byte Ethernet header is present and contiguous 425 * in the first mbuf (if BRIDGE'ing). 426 */ 427 int 428 ether_output_frame(struct ifnet *ifp, struct mbuf *m) 429 { 430 #if defined(INET) || defined(INET6) 431 INIT_VNET_NET(ifp->if_vnet); 432 struct ip_fw *rule = ip_dn_claim_rule(m); 433 434 if (ip_fw_chk_ptr && V_ether_ipfw != 0) { 435 if (ether_ipfw_chk(&m, ifp, &rule, 0) == 0) { 436 if (m) { 437 m_freem(m); 438 return EACCES; /* pkt dropped */ 439 } else 440 return 0; /* consumed e.g. in a pipe */ 441 } 442 } 443 #endif 444 445 /* 446 * Queue message on interface, update output statistics if 447 * successful, and start output if interface not yet active. 448 */ 449 return ((ifp->if_transmit)(ifp, m)); 450 } 451 452 #if defined(INET) || defined(INET6) 453 /* 454 * ipfw processing for ethernet packets (in and out). 455 * The second parameter is NULL from ether_demux, and ifp from 456 * ether_output_frame. 457 */ 458 int 459 ether_ipfw_chk(struct mbuf **m0, struct ifnet *dst, 460 struct ip_fw **rule, int shared) 461 { 462 INIT_VNET_INET(dst->if_vnet); 463 struct ether_header *eh; 464 struct ether_header save_eh; 465 struct mbuf *m; 466 int i; 467 struct ip_fw_args args; 468 469 if (*rule != NULL && V_fw_one_pass) 470 return 1; /* dummynet packet, already partially processed */ 471 472 /* 473 * I need some amt of data to be contiguous, and in case others need 474 * the packet (shared==1) also better be in the first mbuf. 475 */ 476 m = *m0; 477 i = min( m->m_pkthdr.len, max_protohdr); 478 if ( shared || m->m_len < i) { 479 m = m_pullup(m, i); 480 if (m == NULL) { 481 *m0 = m; 482 return 0; 483 } 484 } 485 eh = mtod(m, struct ether_header *); 486 save_eh = *eh; /* save copy for restore below */ 487 m_adj(m, ETHER_HDR_LEN); /* strip ethernet header */ 488 489 args.m = m; /* the packet we are looking at */ 490 args.oif = dst; /* destination, if any */ 491 args.rule = *rule; /* matching rule to restart */ 492 args.next_hop = NULL; /* we do not support forward yet */ 493 args.eh = &save_eh; /* MAC header for bridged/MAC packets */ 494 args.inp = NULL; /* used by ipfw uid/gid/jail rules */ 495 i = ip_fw_chk_ptr(&args); 496 m = args.m; 497 if (m != NULL) { 498 /* 499 * Restore Ethernet header, as needed, in case the 500 * mbuf chain was replaced by ipfw. 501 */ 502 M_PREPEND(m, ETHER_HDR_LEN, M_DONTWAIT); 503 if (m == NULL) { 504 *m0 = m; 505 return 0; 506 } 507 if (eh != mtod(m, struct ether_header *)) 508 bcopy(&save_eh, mtod(m, struct ether_header *), 509 ETHER_HDR_LEN); 510 } 511 *m0 = m; 512 *rule = args.rule; 513 514 if (i == IP_FW_DENY) /* drop */ 515 return 0; 516 517 KASSERT(m != NULL, ("ether_ipfw_chk: m is NULL")); 518 519 if (i == IP_FW_PASS) /* a PASS rule. */ 520 return 1; 521 522 if (ip_dn_io_ptr && (i == IP_FW_DUMMYNET)) { 523 /* 524 * Pass the pkt to dummynet, which consumes it. 525 * If shared, make a copy and keep the original. 526 */ 527 if (shared) { 528 m = m_copypacket(m, M_DONTWAIT); 529 if (m == NULL) 530 return 0; 531 } else { 532 /* 533 * Pass the original to dummynet and 534 * nothing back to the caller 535 */ 536 *m0 = NULL ; 537 } 538 ip_dn_io_ptr(&m, dst ? DN_TO_ETH_OUT: DN_TO_ETH_DEMUX, &args); 539 return 0; 540 } 541 /* 542 * XXX at some point add support for divert/forward actions. 543 * If none of the above matches, we have to drop the pkt. 544 */ 545 return 0; 546 } 547 #endif 548 549 /* 550 * Process a received Ethernet packet; the packet is in the 551 * mbuf chain m with the ethernet header at the front. 552 */ 553 static void 554 ether_input(struct ifnet *ifp, struct mbuf *m) 555 { 556 struct ether_header *eh; 557 u_short etype; 558 559 if ((ifp->if_flags & IFF_UP) == 0) { 560 m_freem(m); 561 return; 562 } 563 #ifdef DIAGNOSTIC 564 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 565 if_printf(ifp, "discard frame at !IFF_DRV_RUNNING\n"); 566 m_freem(m); 567 return; 568 } 569 #endif 570 /* 571 * Do consistency checks to verify assumptions 572 * made by code past this point. 573 */ 574 if ((m->m_flags & M_PKTHDR) == 0) { 575 if_printf(ifp, "discard frame w/o packet header\n"); 576 ifp->if_ierrors++; 577 m_freem(m); 578 return; 579 } 580 if (m->m_len < ETHER_HDR_LEN) { 581 /* XXX maybe should pullup? */ 582 if_printf(ifp, "discard frame w/o leading ethernet " 583 "header (len %u pkt len %u)\n", 584 m->m_len, m->m_pkthdr.len); 585 ifp->if_ierrors++; 586 m_freem(m); 587 return; 588 } 589 eh = mtod(m, struct ether_header *); 590 etype = ntohs(eh->ether_type); 591 if (m->m_pkthdr.rcvif == NULL) { 592 if_printf(ifp, "discard frame w/o interface pointer\n"); 593 ifp->if_ierrors++; 594 m_freem(m); 595 return; 596 } 597 #ifdef DIAGNOSTIC 598 if (m->m_pkthdr.rcvif != ifp) { 599 if_printf(ifp, "Warning, frame marked as received on %s\n", 600 m->m_pkthdr.rcvif->if_xname); 601 } 602 #endif 603 604 CURVNET_SET_QUIET(ifp->if_vnet); 605 606 if (ETHER_IS_MULTICAST(eh->ether_dhost)) { 607 if (ETHER_IS_BROADCAST(eh->ether_dhost)) 608 m->m_flags |= M_BCAST; 609 else 610 m->m_flags |= M_MCAST; 611 ifp->if_imcasts++; 612 } 613 614 #ifdef MAC 615 /* 616 * Tag the mbuf with an appropriate MAC label before any other 617 * consumers can get to it. 618 */ 619 mac_ifnet_create_mbuf(ifp, m); 620 #endif 621 622 /* 623 * Give bpf a chance at the packet. 624 */ 625 ETHER_BPF_MTAP(ifp, m); 626 627 /* 628 * If the CRC is still on the packet, trim it off. We do this once 629 * and once only in case we are re-entered. Nothing else on the 630 * Ethernet receive path expects to see the FCS. 631 */ 632 if (m->m_flags & M_HASFCS) { 633 m_adj(m, -ETHER_CRC_LEN); 634 m->m_flags &= ~M_HASFCS; 635 } 636 637 ifp->if_ibytes += m->m_pkthdr.len; 638 639 /* Allow monitor mode to claim this frame, after stats are updated. */ 640 if (ifp->if_flags & IFF_MONITOR) { 641 m_freem(m); 642 CURVNET_RESTORE(); 643 return; 644 } 645 646 /* Handle input from a lagg(4) port */ 647 if (ifp->if_type == IFT_IEEE8023ADLAG) { 648 KASSERT(lagg_input_p != NULL, 649 ("%s: if_lagg not loaded!", __func__)); 650 m = (*lagg_input_p)(ifp, m); 651 if (m != NULL) 652 ifp = m->m_pkthdr.rcvif; 653 else 654 return; 655 } 656 657 /* 658 * If the hardware did not process an 802.1Q tag, do this now, 659 * to allow 802.1P priority frames to be passed to the main input 660 * path correctly. 661 * TODO: Deal with Q-in-Q frames, but not arbitrary nesting levels. 662 */ 663 if ((m->m_flags & M_VLANTAG) == 0 && etype == ETHERTYPE_VLAN) { 664 struct ether_vlan_header *evl; 665 666 if (m->m_len < sizeof(*evl) && 667 (m = m_pullup(m, sizeof(*evl))) == NULL) { 668 #ifdef DIAGNOSTIC 669 if_printf(ifp, "cannot pullup VLAN header\n"); 670 #endif 671 ifp->if_ierrors++; 672 m_freem(m); 673 return; 674 } 675 676 evl = mtod(m, struct ether_vlan_header *); 677 m->m_pkthdr.ether_vtag = ntohs(evl->evl_tag); 678 m->m_flags |= M_VLANTAG; 679 680 bcopy((char *)evl, (char *)evl + ETHER_VLAN_ENCAP_LEN, 681 ETHER_HDR_LEN - ETHER_TYPE_LEN); 682 m_adj(m, ETHER_VLAN_ENCAP_LEN); 683 } 684 685 /* Allow ng_ether(4) to claim this frame. */ 686 if (IFP2AC(ifp)->ac_netgraph != NULL) { 687 KASSERT(ng_ether_input_p != NULL, 688 ("%s: ng_ether_input_p is NULL", __func__)); 689 m->m_flags &= ~M_PROMISC; 690 (*ng_ether_input_p)(ifp, &m); 691 if (m == NULL) { 692 CURVNET_RESTORE(); 693 return; 694 } 695 } 696 697 /* 698 * Allow if_bridge(4) to claim this frame. 699 * The BRIDGE_INPUT() macro will update ifp if the bridge changed it 700 * and the frame should be delivered locally. 701 */ 702 if (ifp->if_bridge != NULL) { 703 m->m_flags &= ~M_PROMISC; 704 BRIDGE_INPUT(ifp, m); 705 if (m == NULL) { 706 CURVNET_RESTORE(); 707 return; 708 } 709 } 710 711 #ifdef DEV_CARP 712 /* 713 * Clear M_PROMISC on frame so that carp(4) will see it when the 714 * mbuf flows up to Layer 3. 715 * FreeBSD's implementation of carp(4) uses the inprotosw 716 * to dispatch IPPROTO_CARP. carp(4) also allocates its own 717 * Ethernet addresses of the form 00:00:5e:00:01:xx, which 718 * is outside the scope of the M_PROMISC test below. 719 * TODO: Maintain a hash table of ethernet addresses other than 720 * ether_dhost which may be active on this ifp. 721 */ 722 if (ifp->if_carp && carp_forus(ifp->if_carp, eh->ether_dhost)) { 723 m->m_flags &= ~M_PROMISC; 724 } else 725 #endif 726 { 727 /* 728 * If the frame received was not for our MAC address, set the 729 * M_PROMISC flag on the mbuf chain. The frame may need to 730 * be seen by the rest of the Ethernet input path in case of 731 * re-entry (e.g. bridge, vlan, netgraph) but should not be 732 * seen by upper protocol layers. 733 */ 734 if (!ETHER_IS_MULTICAST(eh->ether_dhost) && 735 bcmp(IF_LLADDR(ifp), eh->ether_dhost, ETHER_ADDR_LEN) != 0) 736 m->m_flags |= M_PROMISC; 737 } 738 739 /* First chunk of an mbuf contains good entropy */ 740 if (harvest.ethernet) 741 random_harvest(m, 16, 3, 0, RANDOM_NET); 742 743 ether_demux(ifp, m); 744 CURVNET_RESTORE(); 745 } 746 747 /* 748 * Upper layer processing for a received Ethernet packet. 749 */ 750 void 751 ether_demux(struct ifnet *ifp, struct mbuf *m) 752 { 753 struct ether_header *eh; 754 int isr; 755 u_short ether_type; 756 #if defined(NETATALK) 757 struct llc *l; 758 #endif 759 760 KASSERT(ifp != NULL, ("%s: NULL interface pointer", __func__)); 761 762 #if defined(INET) || defined(INET6) 763 INIT_VNET_NET(ifp->if_vnet); 764 /* 765 * Allow dummynet and/or ipfw to claim the frame. 766 * Do not do this for PROMISC frames in case we are re-entered. 767 */ 768 if (ip_fw_chk_ptr && V_ether_ipfw != 0 && !(m->m_flags & M_PROMISC)) { 769 struct ip_fw *rule = ip_dn_claim_rule(m); 770 771 if (ether_ipfw_chk(&m, NULL, &rule, 0) == 0) { 772 if (m) 773 m_freem(m); /* dropped; free mbuf chain */ 774 return; /* consumed */ 775 } 776 } 777 #endif 778 eh = mtod(m, struct ether_header *); 779 ether_type = ntohs(eh->ether_type); 780 781 /* 782 * If this frame has a VLAN tag other than 0, call vlan_input() 783 * if its module is loaded. Otherwise, drop. 784 */ 785 if ((m->m_flags & M_VLANTAG) && 786 EVL_VLANOFTAG(m->m_pkthdr.ether_vtag) != 0) { 787 if (ifp->if_vlantrunk == NULL) { 788 ifp->if_noproto++; 789 m_freem(m); 790 return; 791 } 792 KASSERT(vlan_input_p != NULL,("%s: VLAN not loaded!", 793 __func__)); 794 /* Clear before possibly re-entering ether_input(). */ 795 m->m_flags &= ~M_PROMISC; 796 (*vlan_input_p)(ifp, m); 797 return; 798 } 799 800 /* 801 * Pass promiscuously received frames to the upper layer if the user 802 * requested this by setting IFF_PPROMISC. Otherwise, drop them. 803 */ 804 if ((ifp->if_flags & IFF_PPROMISC) == 0 && (m->m_flags & M_PROMISC)) { 805 m_freem(m); 806 return; 807 } 808 809 /* 810 * Reset layer specific mbuf flags to avoid confusing upper layers. 811 * Strip off Ethernet header. 812 */ 813 m->m_flags &= ~M_VLANTAG; 814 m->m_flags &= ~(M_PROTOFLAGS); 815 m_adj(m, ETHER_HDR_LEN); 816 817 /* 818 * Dispatch frame to upper layer. 819 */ 820 switch (ether_type) { 821 #ifdef INET 822 case ETHERTYPE_IP: 823 if ((m = ip_fastforward(m)) == NULL) 824 return; 825 isr = NETISR_IP; 826 break; 827 828 case ETHERTYPE_ARP: 829 if (ifp->if_flags & IFF_NOARP) { 830 /* Discard packet if ARP is disabled on interface */ 831 m_freem(m); 832 return; 833 } 834 isr = NETISR_ARP; 835 break; 836 #endif 837 #ifdef IPX 838 case ETHERTYPE_IPX: 839 if (ef_inputp && ef_inputp(ifp, eh, m) == 0) 840 return; 841 isr = NETISR_IPX; 842 break; 843 #endif 844 #ifdef INET6 845 case ETHERTYPE_IPV6: 846 isr = NETISR_IPV6; 847 break; 848 #endif 849 #ifdef NETATALK 850 case ETHERTYPE_AT: 851 isr = NETISR_ATALK1; 852 break; 853 case ETHERTYPE_AARP: 854 isr = NETISR_AARP; 855 break; 856 #endif /* NETATALK */ 857 default: 858 #ifdef IPX 859 if (ef_inputp && ef_inputp(ifp, eh, m) == 0) 860 return; 861 #endif /* IPX */ 862 #if defined(NETATALK) 863 if (ether_type > ETHERMTU) 864 goto discard; 865 l = mtod(m, struct llc *); 866 if (l->llc_dsap == LLC_SNAP_LSAP && 867 l->llc_ssap == LLC_SNAP_LSAP && 868 l->llc_control == LLC_UI) { 869 if (bcmp(&(l->llc_snap_org_code)[0], at_org_code, 870 sizeof(at_org_code)) == 0 && 871 ntohs(l->llc_snap_ether_type) == ETHERTYPE_AT) { 872 m_adj(m, LLC_SNAPFRAMELEN); 873 isr = NETISR_ATALK2; 874 break; 875 } 876 if (bcmp(&(l->llc_snap_org_code)[0], aarp_org_code, 877 sizeof(aarp_org_code)) == 0 && 878 ntohs(l->llc_snap_ether_type) == ETHERTYPE_AARP) { 879 m_adj(m, LLC_SNAPFRAMELEN); 880 isr = NETISR_AARP; 881 break; 882 } 883 } 884 #endif /* NETATALK */ 885 goto discard; 886 } 887 netisr_dispatch(isr, m); 888 return; 889 890 discard: 891 /* 892 * Packet is to be discarded. If netgraph is present, 893 * hand the packet to it for last chance processing; 894 * otherwise dispose of it. 895 */ 896 if (IFP2AC(ifp)->ac_netgraph != NULL) { 897 KASSERT(ng_ether_input_orphan_p != NULL, 898 ("ng_ether_input_orphan_p is NULL")); 899 /* 900 * Put back the ethernet header so netgraph has a 901 * consistent view of inbound packets. 902 */ 903 M_PREPEND(m, ETHER_HDR_LEN, M_DONTWAIT); 904 (*ng_ether_input_orphan_p)(ifp, m); 905 return; 906 } 907 m_freem(m); 908 } 909 910 /* 911 * Convert Ethernet address to printable (loggable) representation. 912 * This routine is for compatibility; it's better to just use 913 * 914 * printf("%6D", <pointer to address>, ":"); 915 * 916 * since there's no static buffer involved. 917 */ 918 char * 919 ether_sprintf(const u_char *ap) 920 { 921 static char etherbuf[18]; 922 snprintf(etherbuf, sizeof (etherbuf), "%6D", ap, ":"); 923 return (etherbuf); 924 } 925 926 /* 927 * Perform common duties while attaching to interface list 928 */ 929 void 930 ether_ifattach(struct ifnet *ifp, const u_int8_t *lla) 931 { 932 int i; 933 struct ifaddr *ifa; 934 struct sockaddr_dl *sdl; 935 936 ifp->if_addrlen = ETHER_ADDR_LEN; 937 ifp->if_hdrlen = ETHER_HDR_LEN; 938 if_attach(ifp); 939 ifp->if_mtu = ETHERMTU; 940 ifp->if_output = ether_output; 941 ifp->if_input = ether_input; 942 ifp->if_resolvemulti = ether_resolvemulti; 943 if (ifp->if_baudrate == 0) 944 ifp->if_baudrate = IF_Mbps(10); /* just a default */ 945 ifp->if_broadcastaddr = etherbroadcastaddr; 946 947 ifa = ifp->if_addr; 948 KASSERT(ifa != NULL, ("%s: no lladdr!\n", __func__)); 949 sdl = (struct sockaddr_dl *)ifa->ifa_addr; 950 sdl->sdl_type = IFT_ETHER; 951 sdl->sdl_alen = ifp->if_addrlen; 952 bcopy(lla, LLADDR(sdl), ifp->if_addrlen); 953 954 bpfattach(ifp, DLT_EN10MB, ETHER_HDR_LEN); 955 if (ng_ether_attach_p != NULL) 956 (*ng_ether_attach_p)(ifp); 957 958 /* Announce Ethernet MAC address if non-zero. */ 959 for (i = 0; i < ifp->if_addrlen; i++) 960 if (lla[i] != 0) 961 break; 962 if (i != ifp->if_addrlen) 963 if_printf(ifp, "Ethernet address: %6D\n", lla, ":"); 964 } 965 966 /* 967 * Perform common duties while detaching an Ethernet interface 968 */ 969 void 970 ether_ifdetach(struct ifnet *ifp) 971 { 972 if (IFP2AC(ifp)->ac_netgraph != NULL) { 973 KASSERT(ng_ether_detach_p != NULL, 974 ("ng_ether_detach_p is NULL")); 975 (*ng_ether_detach_p)(ifp); 976 } 977 978 bpfdetach(ifp); 979 if_detach(ifp); 980 } 981 982 SYSCTL_DECL(_net_link); 983 SYSCTL_NODE(_net_link, IFT_ETHER, ether, CTLFLAG_RW, 0, "Ethernet"); 984 #if defined(INET) || defined(INET6) 985 SYSCTL_V_INT(V_NET, vnet_net, _net_link_ether, OID_AUTO, ipfw, CTLFLAG_RW, 986 ether_ipfw, 0, "Pass ether pkts through firewall"); 987 #endif 988 989 #if 0 990 /* 991 * This is for reference. We have a table-driven version 992 * of the little-endian crc32 generator, which is faster 993 * than the double-loop. 994 */ 995 uint32_t 996 ether_crc32_le(const uint8_t *buf, size_t len) 997 { 998 size_t i; 999 uint32_t crc; 1000 int bit; 1001 uint8_t data; 1002 1003 crc = 0xffffffff; /* initial value */ 1004 1005 for (i = 0; i < len; i++) { 1006 for (data = *buf++, bit = 0; bit < 8; bit++, data >>= 1) { 1007 carry = (crc ^ data) & 1; 1008 crc >>= 1; 1009 if (carry) 1010 crc = (crc ^ ETHER_CRC_POLY_LE); 1011 } 1012 } 1013 1014 return (crc); 1015 } 1016 #else 1017 uint32_t 1018 ether_crc32_le(const uint8_t *buf, size_t len) 1019 { 1020 static const uint32_t crctab[] = { 1021 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac, 1022 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c, 1023 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c, 1024 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c 1025 }; 1026 size_t i; 1027 uint32_t crc; 1028 1029 crc = 0xffffffff; /* initial value */ 1030 1031 for (i = 0; i < len; i++) { 1032 crc ^= buf[i]; 1033 crc = (crc >> 4) ^ crctab[crc & 0xf]; 1034 crc = (crc >> 4) ^ crctab[crc & 0xf]; 1035 } 1036 1037 return (crc); 1038 } 1039 #endif 1040 1041 uint32_t 1042 ether_crc32_be(const uint8_t *buf, size_t len) 1043 { 1044 size_t i; 1045 uint32_t crc, carry; 1046 int bit; 1047 uint8_t data; 1048 1049 crc = 0xffffffff; /* initial value */ 1050 1051 for (i = 0; i < len; i++) { 1052 for (data = *buf++, bit = 0; bit < 8; bit++, data >>= 1) { 1053 carry = ((crc & 0x80000000) ? 1 : 0) ^ (data & 0x01); 1054 crc <<= 1; 1055 if (carry) 1056 crc = (crc ^ ETHER_CRC_POLY_BE) | carry; 1057 } 1058 } 1059 1060 return (crc); 1061 } 1062 1063 int 1064 ether_ioctl(struct ifnet *ifp, u_long command, caddr_t data) 1065 { 1066 struct ifaddr *ifa = (struct ifaddr *) data; 1067 struct ifreq *ifr = (struct ifreq *) data; 1068 int error = 0; 1069 1070 switch (command) { 1071 case SIOCSIFADDR: 1072 ifp->if_flags |= IFF_UP; 1073 1074 switch (ifa->ifa_addr->sa_family) { 1075 #ifdef INET 1076 case AF_INET: 1077 ifp->if_init(ifp->if_softc); /* before arpwhohas */ 1078 arp_ifinit(ifp, ifa); 1079 break; 1080 #endif 1081 #ifdef IPX 1082 /* 1083 * XXX - This code is probably wrong 1084 */ 1085 case AF_IPX: 1086 { 1087 struct ipx_addr *ina = &(IA_SIPX(ifa)->sipx_addr); 1088 1089 if (ipx_nullhost(*ina)) 1090 ina->x_host = 1091 *(union ipx_host *) 1092 IF_LLADDR(ifp); 1093 else { 1094 bcopy((caddr_t) ina->x_host.c_host, 1095 (caddr_t) IF_LLADDR(ifp), 1096 ETHER_ADDR_LEN); 1097 } 1098 1099 /* 1100 * Set new address 1101 */ 1102 ifp->if_init(ifp->if_softc); 1103 break; 1104 } 1105 #endif 1106 default: 1107 ifp->if_init(ifp->if_softc); 1108 break; 1109 } 1110 break; 1111 1112 case SIOCGIFADDR: 1113 { 1114 struct sockaddr *sa; 1115 1116 sa = (struct sockaddr *) & ifr->ifr_data; 1117 bcopy(IF_LLADDR(ifp), 1118 (caddr_t) sa->sa_data, ETHER_ADDR_LEN); 1119 } 1120 break; 1121 1122 case SIOCSIFMTU: 1123 /* 1124 * Set the interface MTU. 1125 */ 1126 if (ifr->ifr_mtu > ETHERMTU) { 1127 error = EINVAL; 1128 } else { 1129 ifp->if_mtu = ifr->ifr_mtu; 1130 } 1131 break; 1132 default: 1133 error = EINVAL; /* XXX netbsd has ENOTTY??? */ 1134 break; 1135 } 1136 return (error); 1137 } 1138 1139 static int 1140 ether_resolvemulti(struct ifnet *ifp, struct sockaddr **llsa, 1141 struct sockaddr *sa) 1142 { 1143 struct sockaddr_dl *sdl; 1144 #ifdef INET 1145 struct sockaddr_in *sin; 1146 #endif 1147 #ifdef INET6 1148 struct sockaddr_in6 *sin6; 1149 #endif 1150 u_char *e_addr; 1151 1152 switch(sa->sa_family) { 1153 case AF_LINK: 1154 /* 1155 * No mapping needed. Just check that it's a valid MC address. 1156 */ 1157 sdl = (struct sockaddr_dl *)sa; 1158 e_addr = LLADDR(sdl); 1159 if (!ETHER_IS_MULTICAST(e_addr)) 1160 return EADDRNOTAVAIL; 1161 *llsa = 0; 1162 return 0; 1163 1164 #ifdef INET 1165 case AF_INET: 1166 sin = (struct sockaddr_in *)sa; 1167 if (!IN_MULTICAST(ntohl(sin->sin_addr.s_addr))) 1168 return EADDRNOTAVAIL; 1169 sdl = malloc(sizeof *sdl, M_IFMADDR, 1170 M_NOWAIT|M_ZERO); 1171 if (sdl == NULL) 1172 return ENOMEM; 1173 sdl->sdl_len = sizeof *sdl; 1174 sdl->sdl_family = AF_LINK; 1175 sdl->sdl_index = ifp->if_index; 1176 sdl->sdl_type = IFT_ETHER; 1177 sdl->sdl_alen = ETHER_ADDR_LEN; 1178 e_addr = LLADDR(sdl); 1179 ETHER_MAP_IP_MULTICAST(&sin->sin_addr, e_addr); 1180 *llsa = (struct sockaddr *)sdl; 1181 return 0; 1182 #endif 1183 #ifdef INET6 1184 case AF_INET6: 1185 sin6 = (struct sockaddr_in6 *)sa; 1186 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) { 1187 /* 1188 * An IP6 address of 0 means listen to all 1189 * of the Ethernet multicast address used for IP6. 1190 * (This is used for multicast routers.) 1191 */ 1192 ifp->if_flags |= IFF_ALLMULTI; 1193 *llsa = 0; 1194 return 0; 1195 } 1196 if (!IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 1197 return EADDRNOTAVAIL; 1198 sdl = malloc(sizeof *sdl, M_IFMADDR, 1199 M_NOWAIT|M_ZERO); 1200 if (sdl == NULL) 1201 return (ENOMEM); 1202 sdl->sdl_len = sizeof *sdl; 1203 sdl->sdl_family = AF_LINK; 1204 sdl->sdl_index = ifp->if_index; 1205 sdl->sdl_type = IFT_ETHER; 1206 sdl->sdl_alen = ETHER_ADDR_LEN; 1207 e_addr = LLADDR(sdl); 1208 ETHER_MAP_IPV6_MULTICAST(&sin6->sin6_addr, e_addr); 1209 *llsa = (struct sockaddr *)sdl; 1210 return 0; 1211 #endif 1212 1213 default: 1214 /* 1215 * Well, the text isn't quite right, but it's the name 1216 * that counts... 1217 */ 1218 return EAFNOSUPPORT; 1219 } 1220 } 1221 1222 static void* 1223 ether_alloc(u_char type, struct ifnet *ifp) 1224 { 1225 struct arpcom *ac; 1226 1227 ac = malloc(sizeof(struct arpcom), M_ARPCOM, M_WAITOK | M_ZERO); 1228 ac->ac_ifp = ifp; 1229 1230 return (ac); 1231 } 1232 1233 static void 1234 ether_free(void *com, u_char type) 1235 { 1236 1237 free(com, M_ARPCOM); 1238 } 1239 1240 static int 1241 ether_modevent(module_t mod, int type, void *data) 1242 { 1243 1244 switch (type) { 1245 case MOD_LOAD: 1246 if_register_com_alloc(IFT_ETHER, ether_alloc, ether_free); 1247 break; 1248 case MOD_UNLOAD: 1249 if_deregister_com_alloc(IFT_ETHER); 1250 break; 1251 default: 1252 return EOPNOTSUPP; 1253 } 1254 1255 return (0); 1256 } 1257 1258 static moduledata_t ether_mod = { 1259 "ether", 1260 ether_modevent, 1261 0 1262 }; 1263 1264 void 1265 ether_vlan_mtap(struct bpf_if *bp, struct mbuf *m, void *data, u_int dlen) 1266 { 1267 struct ether_vlan_header vlan; 1268 struct mbuf mv, mb; 1269 1270 KASSERT((m->m_flags & M_VLANTAG) != 0, 1271 ("%s: vlan information not present", __func__)); 1272 KASSERT(m->m_len >= sizeof(struct ether_header), 1273 ("%s: mbuf not large enough for header", __func__)); 1274 bcopy(mtod(m, char *), &vlan, sizeof(struct ether_header)); 1275 vlan.evl_proto = vlan.evl_encap_proto; 1276 vlan.evl_encap_proto = htons(ETHERTYPE_VLAN); 1277 vlan.evl_tag = htons(m->m_pkthdr.ether_vtag); 1278 m->m_len -= sizeof(struct ether_header); 1279 m->m_data += sizeof(struct ether_header); 1280 /* 1281 * If a data link has been supplied by the caller, then we will need to 1282 * re-create a stack allocated mbuf chain with the following structure: 1283 * 1284 * (1) mbuf #1 will contain the supplied data link 1285 * (2) mbuf #2 will contain the vlan header 1286 * (3) mbuf #3 will contain the original mbuf's packet data 1287 * 1288 * Otherwise, submit the packet and vlan header via bpf_mtap2(). 1289 */ 1290 if (data != NULL) { 1291 mv.m_next = m; 1292 mv.m_data = (caddr_t)&vlan; 1293 mv.m_len = sizeof(vlan); 1294 mb.m_next = &mv; 1295 mb.m_data = data; 1296 mb.m_len = dlen; 1297 bpf_mtap(bp, &mb); 1298 } else 1299 bpf_mtap2(bp, &vlan, sizeof(vlan), m); 1300 m->m_len += sizeof(struct ether_header); 1301 m->m_data -= sizeof(struct ether_header); 1302 } 1303 1304 struct mbuf * 1305 ether_vlanencap(struct mbuf *m, uint16_t tag) 1306 { 1307 struct ether_vlan_header *evl; 1308 1309 M_PREPEND(m, ETHER_VLAN_ENCAP_LEN, M_DONTWAIT); 1310 if (m == NULL) 1311 return (NULL); 1312 /* M_PREPEND takes care of m_len, m_pkthdr.len for us */ 1313 1314 if (m->m_len < sizeof(*evl)) { 1315 m = m_pullup(m, sizeof(*evl)); 1316 if (m == NULL) 1317 return (NULL); 1318 } 1319 1320 /* 1321 * Transform the Ethernet header into an Ethernet header 1322 * with 802.1Q encapsulation. 1323 */ 1324 evl = mtod(m, struct ether_vlan_header *); 1325 bcopy((char *)evl + ETHER_VLAN_ENCAP_LEN, 1326 (char *)evl, ETHER_HDR_LEN - ETHER_TYPE_LEN); 1327 evl->evl_encap_proto = htons(ETHERTYPE_VLAN); 1328 evl->evl_tag = htons(tag); 1329 return (m); 1330 } 1331 1332 DECLARE_MODULE(ether, ether_mod, SI_SUB_INIT_IF, SI_ORDER_ANY); 1333 MODULE_VERSION(ether, 1); 1334