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_netgraph.h" 38 #include "opt_carp.h" 39 #include "opt_mbuf_profiling.h" 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/kernel.h> 44 #include <sys/lock.h> 45 #include <sys/malloc.h> 46 #include <sys/module.h> 47 #include <sys/mbuf.h> 48 #include <sys/random.h> 49 #include <sys/rwlock.h> 50 #include <sys/socket.h> 51 #include <sys/sockio.h> 52 #include <sys/sysctl.h> 53 #include <sys/vimage.h> 54 55 #include <net/if.h> 56 #include <net/if_arp.h> 57 #include <net/netisr.h> 58 #include <net/route.h> 59 #include <net/if_llc.h> 60 #include <net/if_dl.h> 61 #include <net/if_types.h> 62 #include <net/bpf.h> 63 #include <net/ethernet.h> 64 #include <net/if_bridgevar.h> 65 #include <net/if_vlan_var.h> 66 #include <net/if_llatbl.h> 67 #include <net/pf_mtag.h> 68 #include <net/vnet.h> 69 70 #if defined(INET) || defined(INET6) 71 #include <netinet/in.h> 72 #include <netinet/in_var.h> 73 #include <netinet/if_ether.h> 74 #include <netinet/ip_fw.h> 75 #include <netinet/ip_dummynet.h> 76 #include <netinet/ip_var.h> 77 #endif 78 #ifdef INET6 79 #include <netinet6/nd6.h> 80 #endif 81 82 #if defined(INET) || defined(INET6) 83 #ifdef DEV_CARP 84 #include <netinet/ip_carp.h> 85 #endif 86 #endif 87 88 #ifdef IPX 89 #include <netipx/ipx.h> 90 #include <netipx/ipx_if.h> 91 #endif 92 93 int (*ef_inputp)(struct ifnet*, struct ether_header *eh, struct mbuf *m); 94 int (*ef_outputp)(struct ifnet *ifp, struct mbuf **mp, 95 struct sockaddr *dst, short *tp, int *hlen); 96 97 #ifdef NETATALK 98 #include <netatalk/at.h> 99 #include <netatalk/at_var.h> 100 #include <netatalk/at_extern.h> 101 102 #define llc_snap_org_code llc_un.type_snap.org_code 103 #define llc_snap_ether_type llc_un.type_snap.ether_type 104 105 extern u_char at_org_code[3]; 106 extern u_char aarp_org_code[3]; 107 #endif /* NETATALK */ 108 109 #include <security/mac/mac_framework.h> 110 111 #ifdef CTASSERT 112 CTASSERT(sizeof (struct ether_header) == ETHER_ADDR_LEN * 2 + 2); 113 CTASSERT(sizeof (struct ether_addr) == ETHER_ADDR_LEN); 114 #endif 115 116 /* netgraph node hooks for ng_ether(4) */ 117 void (*ng_ether_input_p)(struct ifnet *ifp, struct mbuf **mp); 118 void (*ng_ether_input_orphan_p)(struct ifnet *ifp, struct mbuf *m); 119 int (*ng_ether_output_p)(struct ifnet *ifp, struct mbuf **mp); 120 void (*ng_ether_attach_p)(struct ifnet *ifp); 121 void (*ng_ether_detach_p)(struct ifnet *ifp); 122 123 void (*vlan_input_p)(struct ifnet *, struct mbuf *); 124 125 /* if_bridge(4) support */ 126 struct mbuf *(*bridge_input_p)(struct ifnet *, struct mbuf *); 127 int (*bridge_output_p)(struct ifnet *, struct mbuf *, 128 struct sockaddr *, struct rtentry *); 129 void (*bridge_dn_p)(struct mbuf *, struct ifnet *); 130 131 /* if_lagg(4) support */ 132 struct mbuf *(*lagg_input_p)(struct ifnet *, struct mbuf *); 133 134 static const u_char etherbroadcastaddr[ETHER_ADDR_LEN] = 135 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 136 137 static int ether_resolvemulti(struct ifnet *, struct sockaddr **, 138 struct sockaddr *); 139 140 /* XXX: should be in an arp support file, not here */ 141 MALLOC_DEFINE(M_ARPCOM, "arpcom", "802.* interface internals"); 142 143 #define ETHER_IS_BROADCAST(addr) \ 144 (bcmp(etherbroadcastaddr, (addr), ETHER_ADDR_LEN) == 0) 145 146 #define senderr(e) do { error = (e); goto bad;} while (0) 147 148 #if defined(INET) || defined(INET6) 149 int 150 ether_ipfw_chk(struct mbuf **m0, struct ifnet *dst, int shared); 151 static VNET_DEFINE(int, ether_ipfw); 152 #define V_ether_ipfw VNET(ether_ipfw) 153 #endif 154 155 156 /* 157 * Ethernet output routine. 158 * Encapsulate a packet of type family for the local net. 159 * Use trailer local net encapsulation if enough data in first 160 * packet leaves a multiple of 512 bytes of data in remainder. 161 */ 162 int 163 ether_output(struct ifnet *ifp, struct mbuf *m, 164 struct sockaddr *dst, struct route *ro) 165 { 166 short type; 167 int error = 0, hdrcmplt = 0; 168 u_char esrc[ETHER_ADDR_LEN], edst[ETHER_ADDR_LEN]; 169 struct llentry *lle = NULL; 170 struct rtentry *rt0 = NULL; 171 struct ether_header *eh; 172 struct pf_mtag *t; 173 int loop_copy = 1; 174 int hlen; /* link layer header length */ 175 176 if (ro != NULL) { 177 if (!(m->m_flags & (M_BCAST | M_MCAST))) 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 ifa_free(&aa->aa_ifa); 266 return (0); 267 } 268 /* 269 * In the phase 2 case, need to prepend an mbuf for the llc header. 270 */ 271 if ( aa->aa_flags & AFA_PHASE2 ) { 272 struct llc llc; 273 274 ifa_free(&aa->aa_ifa); 275 M_PREPEND(m, LLC_SNAPFRAMELEN, M_DONTWAIT); 276 if (m == NULL) 277 senderr(ENOBUFS); 278 llc.llc_dsap = llc.llc_ssap = LLC_SNAP_LSAP; 279 llc.llc_control = LLC_UI; 280 bcopy(at_org_code, llc.llc_snap_org_code, sizeof(at_org_code)); 281 llc.llc_snap_ether_type = htons( ETHERTYPE_AT ); 282 bcopy(&llc, mtod(m, caddr_t), LLC_SNAPFRAMELEN); 283 type = htons(m->m_pkthdr.len); 284 hlen = LLC_SNAPFRAMELEN + ETHER_HDR_LEN; 285 } else { 286 ifa_free(&aa->aa_ifa); 287 type = htons(ETHERTYPE_AT); 288 } 289 break; 290 } 291 #endif /* NETATALK */ 292 293 case pseudo_AF_HDRCMPLT: 294 hdrcmplt = 1; 295 eh = (struct ether_header *)dst->sa_data; 296 (void)memcpy(esrc, eh->ether_shost, sizeof (esrc)); 297 /* FALLTHROUGH */ 298 299 case AF_UNSPEC: 300 loop_copy = 0; /* if this is for us, don't do it */ 301 eh = (struct ether_header *)dst->sa_data; 302 (void)memcpy(edst, eh->ether_dhost, sizeof (edst)); 303 type = eh->ether_type; 304 break; 305 306 default: 307 if_printf(ifp, "can't handle af%d\n", dst->sa_family); 308 senderr(EAFNOSUPPORT); 309 } 310 311 if (lle != NULL && (lle->la_flags & LLE_IFADDR)) { 312 int csum_flags = 0; 313 if (m->m_pkthdr.csum_flags & CSUM_IP) 314 csum_flags |= (CSUM_IP_CHECKED|CSUM_IP_VALID); 315 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) 316 csum_flags |= (CSUM_DATA_VALID|CSUM_PSEUDO_HDR); 317 if (m->m_pkthdr.csum_flags & CSUM_SCTP) 318 csum_flags |= CSUM_SCTP_VALID; 319 m->m_pkthdr.csum_flags |= csum_flags; 320 m->m_pkthdr.csum_data = 0xffff; 321 return (if_simloop(ifp, m, dst->sa_family, 0)); 322 } 323 324 /* 325 * Add local net header. If no space in first mbuf, 326 * allocate another. 327 */ 328 M_PREPEND(m, ETHER_HDR_LEN, M_DONTWAIT); 329 if (m == NULL) 330 senderr(ENOBUFS); 331 eh = mtod(m, struct ether_header *); 332 (void)memcpy(&eh->ether_type, &type, 333 sizeof(eh->ether_type)); 334 (void)memcpy(eh->ether_dhost, edst, sizeof (edst)); 335 if (hdrcmplt) 336 (void)memcpy(eh->ether_shost, esrc, 337 sizeof(eh->ether_shost)); 338 else 339 (void)memcpy(eh->ether_shost, IF_LLADDR(ifp), 340 sizeof(eh->ether_shost)); 341 342 /* 343 * If a simplex interface, and the packet is being sent to our 344 * Ethernet address or a broadcast address, loopback a copy. 345 * XXX To make a simplex device behave exactly like a duplex 346 * device, we should copy in the case of sending to our own 347 * ethernet address (thus letting the original actually appear 348 * on the wire). However, we don't do that here for security 349 * reasons and compatibility with the original behavior. 350 */ 351 if ((ifp->if_flags & IFF_SIMPLEX) && loop_copy && 352 ((t = pf_find_mtag(m)) == NULL || !t->routed)) { 353 int csum_flags = 0; 354 355 if (m->m_pkthdr.csum_flags & CSUM_IP) 356 csum_flags |= (CSUM_IP_CHECKED|CSUM_IP_VALID); 357 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) 358 csum_flags |= (CSUM_DATA_VALID|CSUM_PSEUDO_HDR); 359 if (m->m_pkthdr.csum_flags & CSUM_SCTP) 360 csum_flags |= CSUM_SCTP_VALID; 361 362 if (m->m_flags & M_BCAST) { 363 struct mbuf *n; 364 365 /* 366 * Because if_simloop() modifies the packet, we need a 367 * writable copy through m_dup() instead of a readonly 368 * one as m_copy[m] would give us. The alternative would 369 * be to modify if_simloop() to handle the readonly mbuf, 370 * but performancewise it is mostly equivalent (trading 371 * extra data copying vs. extra locking). 372 * 373 * XXX This is a local workaround. A number of less 374 * often used kernel parts suffer from the same bug. 375 * See PR kern/105943 for a proposed general solution. 376 */ 377 if ((n = m_dup(m, M_DONTWAIT)) != NULL) { 378 n->m_pkthdr.csum_flags |= csum_flags; 379 if (csum_flags & CSUM_DATA_VALID) 380 n->m_pkthdr.csum_data = 0xffff; 381 (void)if_simloop(ifp, n, dst->sa_family, hlen); 382 } else 383 ifp->if_iqdrops++; 384 } else if (bcmp(eh->ether_dhost, eh->ether_shost, 385 ETHER_ADDR_LEN) == 0) { 386 m->m_pkthdr.csum_flags |= csum_flags; 387 if (csum_flags & CSUM_DATA_VALID) 388 m->m_pkthdr.csum_data = 0xffff; 389 (void) if_simloop(ifp, m, dst->sa_family, hlen); 390 return (0); /* XXX */ 391 } 392 } 393 394 /* 395 * Bridges require special output handling. 396 */ 397 if (ifp->if_bridge) { 398 BRIDGE_OUTPUT(ifp, m, error); 399 return (error); 400 } 401 402 #if defined(INET) || defined(INET6) 403 #ifdef DEV_CARP 404 if (ifp->if_carp && 405 (error = carp_output(ifp, m, dst, NULL))) 406 goto bad; 407 #endif 408 #endif 409 410 /* Handle ng_ether(4) processing, if any */ 411 if (IFP2AC(ifp)->ac_netgraph != NULL) { 412 KASSERT(ng_ether_output_p != NULL, 413 ("ng_ether_output_p is NULL")); 414 if ((error = (*ng_ether_output_p)(ifp, &m)) != 0) { 415 bad: if (m != NULL) 416 m_freem(m); 417 return (error); 418 } 419 if (m == NULL) 420 return (0); 421 } 422 423 /* Continue with link-layer output */ 424 return ether_output_frame(ifp, m); 425 } 426 427 /* 428 * Ethernet link layer output routine to send a raw frame to the device. 429 * 430 * This assumes that the 14 byte Ethernet header is present and contiguous 431 * in the first mbuf (if BRIDGE'ing). 432 */ 433 int 434 ether_output_frame(struct ifnet *ifp, struct mbuf *m) 435 { 436 #if defined(INET) || defined(INET6) 437 438 if (ip_fw_chk_ptr && V_ether_ipfw != 0) { 439 if (ether_ipfw_chk(&m, ifp, 0) == 0) { 440 if (m) { 441 m_freem(m); 442 return EACCES; /* pkt dropped */ 443 } else 444 return 0; /* consumed e.g. in a pipe */ 445 } 446 } 447 #endif 448 449 /* 450 * Queue message on interface, update output statistics if 451 * successful, and start output if interface not yet active. 452 */ 453 return ((ifp->if_transmit)(ifp, m)); 454 } 455 456 #if defined(INET) || defined(INET6) 457 /* 458 * ipfw processing for ethernet packets (in and out). 459 * The second parameter is NULL from ether_demux, and ifp from 460 * ether_output_frame. 461 */ 462 int 463 ether_ipfw_chk(struct mbuf **m0, struct ifnet *dst, int shared) 464 { 465 struct ether_header *eh; 466 struct ether_header save_eh; 467 struct mbuf *m; 468 int i; 469 struct ip_fw_args args; 470 struct dn_pkt_tag *dn_tag; 471 472 dn_tag = ip_dn_claim_tag(*m0); 473 474 if (dn_tag != NULL) { 475 if (dn_tag->rule != NULL && V_fw_one_pass) 476 /* dummynet packet, already partially processed */ 477 return (1); 478 args.rule = dn_tag->rule; /* matching rule to restart */ 479 args.rule_id = dn_tag->rule_id; 480 args.chain_id = dn_tag->chain_id; 481 } else 482 args.rule = NULL; 483 484 /* 485 * I need some amt of data to be contiguous, and in case others need 486 * the packet (shared==1) also better be in the first mbuf. 487 */ 488 m = *m0; 489 i = min( m->m_pkthdr.len, max_protohdr); 490 if ( shared || m->m_len < i) { 491 m = m_pullup(m, i); 492 if (m == NULL) { 493 *m0 = m; 494 return 0; 495 } 496 } 497 eh = mtod(m, struct ether_header *); 498 save_eh = *eh; /* save copy for restore below */ 499 m_adj(m, ETHER_HDR_LEN); /* strip ethernet header */ 500 501 args.m = m; /* the packet we are looking at */ 502 args.oif = dst; /* destination, if any */ 503 args.next_hop = NULL; /* we do not support forward yet */ 504 args.eh = &save_eh; /* MAC header for bridged/MAC packets */ 505 args.inp = NULL; /* used by ipfw uid/gid/jail rules */ 506 i = ip_fw_chk_ptr(&args); 507 m = args.m; 508 if (m != NULL) { 509 /* 510 * Restore Ethernet header, as needed, in case the 511 * mbuf chain was replaced by ipfw. 512 */ 513 M_PREPEND(m, ETHER_HDR_LEN, M_DONTWAIT); 514 if (m == NULL) { 515 *m0 = m; 516 return 0; 517 } 518 if (eh != mtod(m, struct ether_header *)) 519 bcopy(&save_eh, mtod(m, struct ether_header *), 520 ETHER_HDR_LEN); 521 } 522 *m0 = m; 523 524 if (i == IP_FW_DENY) /* drop */ 525 return 0; 526 527 KASSERT(m != NULL, ("ether_ipfw_chk: m is NULL")); 528 529 if (i == IP_FW_PASS) /* a PASS rule. */ 530 return 1; 531 532 if (ip_dn_io_ptr && (i == IP_FW_DUMMYNET)) { 533 /* 534 * Pass the pkt to dummynet, which consumes it. 535 * If shared, make a copy and keep the original. 536 */ 537 if (shared) { 538 m = m_copypacket(m, M_DONTWAIT); 539 if (m == NULL) 540 return 0; 541 } else { 542 /* 543 * Pass the original to dummynet and 544 * nothing back to the caller 545 */ 546 *m0 = NULL ; 547 } 548 ip_dn_io_ptr(&m, dst ? DN_TO_ETH_OUT: DN_TO_ETH_DEMUX, &args); 549 return 0; 550 } 551 /* 552 * XXX at some point add support for divert/forward actions. 553 * If none of the above matches, we have to drop the pkt. 554 */ 555 return 0; 556 } 557 #endif 558 559 /* 560 * Process a received Ethernet packet; the packet is in the 561 * mbuf chain m with the ethernet header at the front. 562 */ 563 static void 564 ether_input(struct ifnet *ifp, struct mbuf *m) 565 { 566 struct ether_header *eh; 567 u_short etype; 568 569 if ((ifp->if_flags & IFF_UP) == 0) { 570 m_freem(m); 571 return; 572 } 573 #ifdef DIAGNOSTIC 574 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 575 if_printf(ifp, "discard frame at !IFF_DRV_RUNNING\n"); 576 m_freem(m); 577 return; 578 } 579 #endif 580 /* 581 * Do consistency checks to verify assumptions 582 * made by code past this point. 583 */ 584 if ((m->m_flags & M_PKTHDR) == 0) { 585 if_printf(ifp, "discard frame w/o packet header\n"); 586 ifp->if_ierrors++; 587 m_freem(m); 588 return; 589 } 590 if (m->m_len < ETHER_HDR_LEN) { 591 /* XXX maybe should pullup? */ 592 if_printf(ifp, "discard frame w/o leading ethernet " 593 "header (len %u pkt len %u)\n", 594 m->m_len, m->m_pkthdr.len); 595 ifp->if_ierrors++; 596 m_freem(m); 597 return; 598 } 599 eh = mtod(m, struct ether_header *); 600 etype = ntohs(eh->ether_type); 601 if (m->m_pkthdr.rcvif == NULL) { 602 if_printf(ifp, "discard frame w/o interface pointer\n"); 603 ifp->if_ierrors++; 604 m_freem(m); 605 return; 606 } 607 #ifdef DIAGNOSTIC 608 if (m->m_pkthdr.rcvif != ifp) { 609 if_printf(ifp, "Warning, frame marked as received on %s\n", 610 m->m_pkthdr.rcvif->if_xname); 611 } 612 #endif 613 614 CURVNET_SET_QUIET(ifp->if_vnet); 615 616 if (ETHER_IS_MULTICAST(eh->ether_dhost)) { 617 if (ETHER_IS_BROADCAST(eh->ether_dhost)) 618 m->m_flags |= M_BCAST; 619 else 620 m->m_flags |= M_MCAST; 621 ifp->if_imcasts++; 622 } 623 624 #ifdef MAC 625 /* 626 * Tag the mbuf with an appropriate MAC label before any other 627 * consumers can get to it. 628 */ 629 mac_ifnet_create_mbuf(ifp, m); 630 #endif 631 632 /* 633 * Give bpf a chance at the packet. 634 */ 635 ETHER_BPF_MTAP(ifp, m); 636 637 /* 638 * If the CRC is still on the packet, trim it off. We do this once 639 * and once only in case we are re-entered. Nothing else on the 640 * Ethernet receive path expects to see the FCS. 641 */ 642 if (m->m_flags & M_HASFCS) { 643 m_adj(m, -ETHER_CRC_LEN); 644 m->m_flags &= ~M_HASFCS; 645 } 646 647 ifp->if_ibytes += m->m_pkthdr.len; 648 649 /* Allow monitor mode to claim this frame, after stats are updated. */ 650 if (ifp->if_flags & IFF_MONITOR) { 651 m_freem(m); 652 CURVNET_RESTORE(); 653 return; 654 } 655 656 /* Handle input from a lagg(4) port */ 657 if (ifp->if_type == IFT_IEEE8023ADLAG) { 658 KASSERT(lagg_input_p != NULL, 659 ("%s: if_lagg not loaded!", __func__)); 660 m = (*lagg_input_p)(ifp, m); 661 if (m != NULL) 662 ifp = m->m_pkthdr.rcvif; 663 else 664 return; 665 } 666 667 /* 668 * If the hardware did not process an 802.1Q tag, do this now, 669 * to allow 802.1P priority frames to be passed to the main input 670 * path correctly. 671 * TODO: Deal with Q-in-Q frames, but not arbitrary nesting levels. 672 */ 673 if ((m->m_flags & M_VLANTAG) == 0 && etype == ETHERTYPE_VLAN) { 674 struct ether_vlan_header *evl; 675 676 if (m->m_len < sizeof(*evl) && 677 (m = m_pullup(m, sizeof(*evl))) == NULL) { 678 #ifdef DIAGNOSTIC 679 if_printf(ifp, "cannot pullup VLAN header\n"); 680 #endif 681 ifp->if_ierrors++; 682 m_freem(m); 683 return; 684 } 685 686 evl = mtod(m, struct ether_vlan_header *); 687 m->m_pkthdr.ether_vtag = ntohs(evl->evl_tag); 688 m->m_flags |= M_VLANTAG; 689 690 bcopy((char *)evl, (char *)evl + ETHER_VLAN_ENCAP_LEN, 691 ETHER_HDR_LEN - ETHER_TYPE_LEN); 692 m_adj(m, ETHER_VLAN_ENCAP_LEN); 693 } 694 695 /* Allow ng_ether(4) to claim this frame. */ 696 if (IFP2AC(ifp)->ac_netgraph != NULL) { 697 KASSERT(ng_ether_input_p != NULL, 698 ("%s: ng_ether_input_p is NULL", __func__)); 699 m->m_flags &= ~M_PROMISC; 700 (*ng_ether_input_p)(ifp, &m); 701 if (m == NULL) { 702 CURVNET_RESTORE(); 703 return; 704 } 705 } 706 707 /* 708 * Allow if_bridge(4) to claim this frame. 709 * The BRIDGE_INPUT() macro will update ifp if the bridge changed it 710 * and the frame should be delivered locally. 711 */ 712 if (ifp->if_bridge != NULL) { 713 m->m_flags &= ~M_PROMISC; 714 BRIDGE_INPUT(ifp, m); 715 if (m == NULL) { 716 CURVNET_RESTORE(); 717 return; 718 } 719 } 720 721 #if defined(INET) || defined(INET6) 722 #ifdef DEV_CARP 723 /* 724 * Clear M_PROMISC on frame so that carp(4) will see it when the 725 * mbuf flows up to Layer 3. 726 * FreeBSD's implementation of carp(4) uses the inprotosw 727 * to dispatch IPPROTO_CARP. carp(4) also allocates its own 728 * Ethernet addresses of the form 00:00:5e:00:01:xx, which 729 * is outside the scope of the M_PROMISC test below. 730 * TODO: Maintain a hash table of ethernet addresses other than 731 * ether_dhost which may be active on this ifp. 732 */ 733 if (ifp->if_carp && carp_forus(ifp->if_carp, eh->ether_dhost)) { 734 m->m_flags &= ~M_PROMISC; 735 } else 736 #endif 737 #endif 738 { 739 /* 740 * If the frame received was not for our MAC address, set the 741 * M_PROMISC flag on the mbuf chain. The frame may need to 742 * be seen by the rest of the Ethernet input path in case of 743 * re-entry (e.g. bridge, vlan, netgraph) but should not be 744 * seen by upper protocol layers. 745 */ 746 if (!ETHER_IS_MULTICAST(eh->ether_dhost) && 747 bcmp(IF_LLADDR(ifp), eh->ether_dhost, ETHER_ADDR_LEN) != 0) 748 m->m_flags |= M_PROMISC; 749 } 750 751 /* First chunk of an mbuf contains good entropy */ 752 if (harvest.ethernet) 753 random_harvest(m, 16, 3, 0, RANDOM_NET); 754 755 ether_demux(ifp, m); 756 CURVNET_RESTORE(); 757 } 758 759 /* 760 * Upper layer processing for a received Ethernet packet. 761 */ 762 void 763 ether_demux(struct ifnet *ifp, struct mbuf *m) 764 { 765 struct ether_header *eh; 766 int isr; 767 u_short ether_type; 768 #if defined(NETATALK) 769 struct llc *l; 770 #endif 771 772 KASSERT(ifp != NULL, ("%s: NULL interface pointer", __func__)); 773 774 #if defined(INET) || defined(INET6) 775 /* 776 * Allow dummynet and/or ipfw to claim the frame. 777 * Do not do this for PROMISC frames in case we are re-entered. 778 */ 779 if (ip_fw_chk_ptr && V_ether_ipfw != 0 && !(m->m_flags & M_PROMISC)) { 780 if (ether_ipfw_chk(&m, NULL, 0) == 0) { 781 if (m) 782 m_freem(m); /* dropped; free mbuf chain */ 783 return; /* consumed */ 784 } 785 } 786 #endif 787 eh = mtod(m, struct ether_header *); 788 ether_type = ntohs(eh->ether_type); 789 790 /* 791 * If this frame has a VLAN tag other than 0, call vlan_input() 792 * if its module is loaded. Otherwise, drop. 793 */ 794 if ((m->m_flags & M_VLANTAG) && 795 EVL_VLANOFTAG(m->m_pkthdr.ether_vtag) != 0) { 796 if (ifp->if_vlantrunk == NULL) { 797 ifp->if_noproto++; 798 m_freem(m); 799 return; 800 } 801 KASSERT(vlan_input_p != NULL,("%s: VLAN not loaded!", 802 __func__)); 803 /* Clear before possibly re-entering ether_input(). */ 804 m->m_flags &= ~M_PROMISC; 805 (*vlan_input_p)(ifp, m); 806 return; 807 } 808 809 /* 810 * Pass promiscuously received frames to the upper layer if the user 811 * requested this by setting IFF_PPROMISC. Otherwise, drop them. 812 */ 813 if ((ifp->if_flags & IFF_PPROMISC) == 0 && (m->m_flags & M_PROMISC)) { 814 m_freem(m); 815 return; 816 } 817 818 /* 819 * Reset layer specific mbuf flags to avoid confusing upper layers. 820 * Strip off Ethernet header. 821 */ 822 m->m_flags &= ~M_VLANTAG; 823 m->m_flags &= ~(M_PROTOFLAGS); 824 m_adj(m, ETHER_HDR_LEN); 825 826 /* 827 * Dispatch frame to upper layer. 828 */ 829 switch (ether_type) { 830 #ifdef INET 831 case ETHERTYPE_IP: 832 if ((m = ip_fastforward(m)) == NULL) 833 return; 834 isr = NETISR_IP; 835 break; 836 837 case ETHERTYPE_ARP: 838 if (ifp->if_flags & IFF_NOARP) { 839 /* Discard packet if ARP is disabled on interface */ 840 m_freem(m); 841 return; 842 } 843 isr = NETISR_ARP; 844 break; 845 #endif 846 #ifdef IPX 847 case ETHERTYPE_IPX: 848 if (ef_inputp && ef_inputp(ifp, eh, m) == 0) 849 return; 850 isr = NETISR_IPX; 851 break; 852 #endif 853 #ifdef INET6 854 case ETHERTYPE_IPV6: 855 isr = NETISR_IPV6; 856 break; 857 #endif 858 #ifdef NETATALK 859 case ETHERTYPE_AT: 860 isr = NETISR_ATALK1; 861 break; 862 case ETHERTYPE_AARP: 863 isr = NETISR_AARP; 864 break; 865 #endif /* NETATALK */ 866 default: 867 #ifdef IPX 868 if (ef_inputp && ef_inputp(ifp, eh, m) == 0) 869 return; 870 #endif /* IPX */ 871 #if defined(NETATALK) 872 if (ether_type > ETHERMTU) 873 goto discard; 874 l = mtod(m, struct llc *); 875 if (l->llc_dsap == LLC_SNAP_LSAP && 876 l->llc_ssap == LLC_SNAP_LSAP && 877 l->llc_control == LLC_UI) { 878 if (bcmp(&(l->llc_snap_org_code)[0], at_org_code, 879 sizeof(at_org_code)) == 0 && 880 ntohs(l->llc_snap_ether_type) == ETHERTYPE_AT) { 881 m_adj(m, LLC_SNAPFRAMELEN); 882 isr = NETISR_ATALK2; 883 break; 884 } 885 if (bcmp(&(l->llc_snap_org_code)[0], aarp_org_code, 886 sizeof(aarp_org_code)) == 0 && 887 ntohs(l->llc_snap_ether_type) == ETHERTYPE_AARP) { 888 m_adj(m, LLC_SNAPFRAMELEN); 889 isr = NETISR_AARP; 890 break; 891 } 892 } 893 #endif /* NETATALK */ 894 goto discard; 895 } 896 netisr_dispatch(isr, m); 897 return; 898 899 discard: 900 /* 901 * Packet is to be discarded. If netgraph is present, 902 * hand the packet to it for last chance processing; 903 * otherwise dispose of it. 904 */ 905 if (IFP2AC(ifp)->ac_netgraph != NULL) { 906 KASSERT(ng_ether_input_orphan_p != NULL, 907 ("ng_ether_input_orphan_p is NULL")); 908 /* 909 * Put back the ethernet header so netgraph has a 910 * consistent view of inbound packets. 911 */ 912 M_PREPEND(m, ETHER_HDR_LEN, M_DONTWAIT); 913 (*ng_ether_input_orphan_p)(ifp, m); 914 return; 915 } 916 m_freem(m); 917 } 918 919 /* 920 * Convert Ethernet address to printable (loggable) representation. 921 * This routine is for compatibility; it's better to just use 922 * 923 * printf("%6D", <pointer to address>, ":"); 924 * 925 * since there's no static buffer involved. 926 */ 927 char * 928 ether_sprintf(const u_char *ap) 929 { 930 static char etherbuf[18]; 931 snprintf(etherbuf, sizeof (etherbuf), "%6D", ap, ":"); 932 return (etherbuf); 933 } 934 935 /* 936 * Perform common duties while attaching to interface list 937 */ 938 void 939 ether_ifattach(struct ifnet *ifp, const u_int8_t *lla) 940 { 941 int i; 942 struct ifaddr *ifa; 943 struct sockaddr_dl *sdl; 944 945 ifp->if_addrlen = ETHER_ADDR_LEN; 946 ifp->if_hdrlen = ETHER_HDR_LEN; 947 if_attach(ifp); 948 ifp->if_mtu = ETHERMTU; 949 ifp->if_output = ether_output; 950 ifp->if_input = ether_input; 951 ifp->if_resolvemulti = ether_resolvemulti; 952 if (ifp->if_baudrate == 0) 953 ifp->if_baudrate = IF_Mbps(10); /* just a default */ 954 ifp->if_broadcastaddr = etherbroadcastaddr; 955 956 ifa = ifp->if_addr; 957 KASSERT(ifa != NULL, ("%s: no lladdr!\n", __func__)); 958 sdl = (struct sockaddr_dl *)ifa->ifa_addr; 959 sdl->sdl_type = IFT_ETHER; 960 sdl->sdl_alen = ifp->if_addrlen; 961 bcopy(lla, LLADDR(sdl), ifp->if_addrlen); 962 963 bpfattach(ifp, DLT_EN10MB, ETHER_HDR_LEN); 964 if (ng_ether_attach_p != NULL) 965 (*ng_ether_attach_p)(ifp); 966 967 /* Announce Ethernet MAC address if non-zero. */ 968 for (i = 0; i < ifp->if_addrlen; i++) 969 if (lla[i] != 0) 970 break; 971 if (i != ifp->if_addrlen) 972 if_printf(ifp, "Ethernet address: %6D\n", lla, ":"); 973 } 974 975 /* 976 * Perform common duties while detaching an Ethernet interface 977 */ 978 void 979 ether_ifdetach(struct ifnet *ifp) 980 { 981 if (IFP2AC(ifp)->ac_netgraph != NULL) { 982 KASSERT(ng_ether_detach_p != NULL, 983 ("ng_ether_detach_p is NULL")); 984 (*ng_ether_detach_p)(ifp); 985 } 986 987 bpfdetach(ifp); 988 if_detach(ifp); 989 } 990 991 SYSCTL_DECL(_net_link); 992 SYSCTL_NODE(_net_link, IFT_ETHER, ether, CTLFLAG_RW, 0, "Ethernet"); 993 #if defined(INET) || defined(INET6) 994 SYSCTL_VNET_INT(_net_link_ether, OID_AUTO, ipfw, CTLFLAG_RW, 995 &VNET_NAME(ether_ipfw), 0, "Pass ether pkts through firewall"); 996 #endif 997 998 #if 0 999 /* 1000 * This is for reference. We have a table-driven version 1001 * of the little-endian crc32 generator, which is faster 1002 * than the double-loop. 1003 */ 1004 uint32_t 1005 ether_crc32_le(const uint8_t *buf, size_t len) 1006 { 1007 size_t i; 1008 uint32_t crc; 1009 int bit; 1010 uint8_t data; 1011 1012 crc = 0xffffffff; /* initial value */ 1013 1014 for (i = 0; i < len; i++) { 1015 for (data = *buf++, bit = 0; bit < 8; bit++, data >>= 1) { 1016 carry = (crc ^ data) & 1; 1017 crc >>= 1; 1018 if (carry) 1019 crc = (crc ^ ETHER_CRC_POLY_LE); 1020 } 1021 } 1022 1023 return (crc); 1024 } 1025 #else 1026 uint32_t 1027 ether_crc32_le(const uint8_t *buf, size_t len) 1028 { 1029 static const uint32_t crctab[] = { 1030 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac, 1031 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c, 1032 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c, 1033 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c 1034 }; 1035 size_t i; 1036 uint32_t crc; 1037 1038 crc = 0xffffffff; /* initial value */ 1039 1040 for (i = 0; i < len; i++) { 1041 crc ^= buf[i]; 1042 crc = (crc >> 4) ^ crctab[crc & 0xf]; 1043 crc = (crc >> 4) ^ crctab[crc & 0xf]; 1044 } 1045 1046 return (crc); 1047 } 1048 #endif 1049 1050 uint32_t 1051 ether_crc32_be(const uint8_t *buf, size_t len) 1052 { 1053 size_t i; 1054 uint32_t crc, carry; 1055 int bit; 1056 uint8_t data; 1057 1058 crc = 0xffffffff; /* initial value */ 1059 1060 for (i = 0; i < len; i++) { 1061 for (data = *buf++, bit = 0; bit < 8; bit++, data >>= 1) { 1062 carry = ((crc & 0x80000000) ? 1 : 0) ^ (data & 0x01); 1063 crc <<= 1; 1064 if (carry) 1065 crc = (crc ^ ETHER_CRC_POLY_BE) | carry; 1066 } 1067 } 1068 1069 return (crc); 1070 } 1071 1072 int 1073 ether_ioctl(struct ifnet *ifp, u_long command, caddr_t data) 1074 { 1075 struct ifaddr *ifa = (struct ifaddr *) data; 1076 struct ifreq *ifr = (struct ifreq *) data; 1077 int error = 0; 1078 1079 switch (command) { 1080 case SIOCSIFADDR: 1081 ifp->if_flags |= IFF_UP; 1082 1083 switch (ifa->ifa_addr->sa_family) { 1084 #ifdef INET 1085 case AF_INET: 1086 ifp->if_init(ifp->if_softc); /* before arpwhohas */ 1087 arp_ifinit(ifp, ifa); 1088 break; 1089 #endif 1090 #ifdef IPX 1091 /* 1092 * XXX - This code is probably wrong 1093 */ 1094 case AF_IPX: 1095 { 1096 struct ipx_addr *ina = &(IA_SIPX(ifa)->sipx_addr); 1097 1098 if (ipx_nullhost(*ina)) 1099 ina->x_host = 1100 *(union ipx_host *) 1101 IF_LLADDR(ifp); 1102 else { 1103 bcopy((caddr_t) ina->x_host.c_host, 1104 (caddr_t) IF_LLADDR(ifp), 1105 ETHER_ADDR_LEN); 1106 } 1107 1108 /* 1109 * Set new address 1110 */ 1111 ifp->if_init(ifp->if_softc); 1112 break; 1113 } 1114 #endif 1115 default: 1116 ifp->if_init(ifp->if_softc); 1117 break; 1118 } 1119 break; 1120 1121 case SIOCGIFADDR: 1122 { 1123 struct sockaddr *sa; 1124 1125 sa = (struct sockaddr *) & ifr->ifr_data; 1126 bcopy(IF_LLADDR(ifp), 1127 (caddr_t) sa->sa_data, ETHER_ADDR_LEN); 1128 } 1129 break; 1130 1131 case SIOCSIFMTU: 1132 /* 1133 * Set the interface MTU. 1134 */ 1135 if (ifr->ifr_mtu > ETHERMTU) { 1136 error = EINVAL; 1137 } else { 1138 ifp->if_mtu = ifr->ifr_mtu; 1139 } 1140 break; 1141 default: 1142 error = EINVAL; /* XXX netbsd has ENOTTY??? */ 1143 break; 1144 } 1145 return (error); 1146 } 1147 1148 static int 1149 ether_resolvemulti(struct ifnet *ifp, struct sockaddr **llsa, 1150 struct sockaddr *sa) 1151 { 1152 struct sockaddr_dl *sdl; 1153 #ifdef INET 1154 struct sockaddr_in *sin; 1155 #endif 1156 #ifdef INET6 1157 struct sockaddr_in6 *sin6; 1158 #endif 1159 u_char *e_addr; 1160 1161 switch(sa->sa_family) { 1162 case AF_LINK: 1163 /* 1164 * No mapping needed. Just check that it's a valid MC address. 1165 */ 1166 sdl = (struct sockaddr_dl *)sa; 1167 e_addr = LLADDR(sdl); 1168 if (!ETHER_IS_MULTICAST(e_addr)) 1169 return EADDRNOTAVAIL; 1170 *llsa = 0; 1171 return 0; 1172 1173 #ifdef INET 1174 case AF_INET: 1175 sin = (struct sockaddr_in *)sa; 1176 if (!IN_MULTICAST(ntohl(sin->sin_addr.s_addr))) 1177 return EADDRNOTAVAIL; 1178 sdl = malloc(sizeof *sdl, M_IFMADDR, 1179 M_NOWAIT|M_ZERO); 1180 if (sdl == NULL) 1181 return ENOMEM; 1182 sdl->sdl_len = sizeof *sdl; 1183 sdl->sdl_family = AF_LINK; 1184 sdl->sdl_index = ifp->if_index; 1185 sdl->sdl_type = IFT_ETHER; 1186 sdl->sdl_alen = ETHER_ADDR_LEN; 1187 e_addr = LLADDR(sdl); 1188 ETHER_MAP_IP_MULTICAST(&sin->sin_addr, e_addr); 1189 *llsa = (struct sockaddr *)sdl; 1190 return 0; 1191 #endif 1192 #ifdef INET6 1193 case AF_INET6: 1194 sin6 = (struct sockaddr_in6 *)sa; 1195 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) { 1196 /* 1197 * An IP6 address of 0 means listen to all 1198 * of the Ethernet multicast address used for IP6. 1199 * (This is used for multicast routers.) 1200 */ 1201 ifp->if_flags |= IFF_ALLMULTI; 1202 *llsa = 0; 1203 return 0; 1204 } 1205 if (!IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 1206 return EADDRNOTAVAIL; 1207 sdl = malloc(sizeof *sdl, M_IFMADDR, 1208 M_NOWAIT|M_ZERO); 1209 if (sdl == NULL) 1210 return (ENOMEM); 1211 sdl->sdl_len = sizeof *sdl; 1212 sdl->sdl_family = AF_LINK; 1213 sdl->sdl_index = ifp->if_index; 1214 sdl->sdl_type = IFT_ETHER; 1215 sdl->sdl_alen = ETHER_ADDR_LEN; 1216 e_addr = LLADDR(sdl); 1217 ETHER_MAP_IPV6_MULTICAST(&sin6->sin6_addr, e_addr); 1218 *llsa = (struct sockaddr *)sdl; 1219 return 0; 1220 #endif 1221 1222 default: 1223 /* 1224 * Well, the text isn't quite right, but it's the name 1225 * that counts... 1226 */ 1227 return EAFNOSUPPORT; 1228 } 1229 } 1230 1231 static void* 1232 ether_alloc(u_char type, struct ifnet *ifp) 1233 { 1234 struct arpcom *ac; 1235 1236 ac = malloc(sizeof(struct arpcom), M_ARPCOM, M_WAITOK | M_ZERO); 1237 ac->ac_ifp = ifp; 1238 1239 return (ac); 1240 } 1241 1242 static void 1243 ether_free(void *com, u_char type) 1244 { 1245 1246 free(com, M_ARPCOM); 1247 } 1248 1249 static int 1250 ether_modevent(module_t mod, int type, void *data) 1251 { 1252 1253 switch (type) { 1254 case MOD_LOAD: 1255 if_register_com_alloc(IFT_ETHER, ether_alloc, ether_free); 1256 break; 1257 case MOD_UNLOAD: 1258 if_deregister_com_alloc(IFT_ETHER); 1259 break; 1260 default: 1261 return EOPNOTSUPP; 1262 } 1263 1264 return (0); 1265 } 1266 1267 static moduledata_t ether_mod = { 1268 "ether", 1269 ether_modevent, 1270 0 1271 }; 1272 1273 void 1274 ether_vlan_mtap(struct bpf_if *bp, struct mbuf *m, void *data, u_int dlen) 1275 { 1276 struct ether_vlan_header vlan; 1277 struct mbuf mv, mb; 1278 1279 KASSERT((m->m_flags & M_VLANTAG) != 0, 1280 ("%s: vlan information not present", __func__)); 1281 KASSERT(m->m_len >= sizeof(struct ether_header), 1282 ("%s: mbuf not large enough for header", __func__)); 1283 bcopy(mtod(m, char *), &vlan, sizeof(struct ether_header)); 1284 vlan.evl_proto = vlan.evl_encap_proto; 1285 vlan.evl_encap_proto = htons(ETHERTYPE_VLAN); 1286 vlan.evl_tag = htons(m->m_pkthdr.ether_vtag); 1287 m->m_len -= sizeof(struct ether_header); 1288 m->m_data += sizeof(struct ether_header); 1289 /* 1290 * If a data link has been supplied by the caller, then we will need to 1291 * re-create a stack allocated mbuf chain with the following structure: 1292 * 1293 * (1) mbuf #1 will contain the supplied data link 1294 * (2) mbuf #2 will contain the vlan header 1295 * (3) mbuf #3 will contain the original mbuf's packet data 1296 * 1297 * Otherwise, submit the packet and vlan header via bpf_mtap2(). 1298 */ 1299 if (data != NULL) { 1300 mv.m_next = m; 1301 mv.m_data = (caddr_t)&vlan; 1302 mv.m_len = sizeof(vlan); 1303 mb.m_next = &mv; 1304 mb.m_data = data; 1305 mb.m_len = dlen; 1306 bpf_mtap(bp, &mb); 1307 } else 1308 bpf_mtap2(bp, &vlan, sizeof(vlan), m); 1309 m->m_len += sizeof(struct ether_header); 1310 m->m_data -= sizeof(struct ether_header); 1311 } 1312 1313 struct mbuf * 1314 ether_vlanencap(struct mbuf *m, uint16_t tag) 1315 { 1316 struct ether_vlan_header *evl; 1317 1318 M_PREPEND(m, ETHER_VLAN_ENCAP_LEN, M_DONTWAIT); 1319 if (m == NULL) 1320 return (NULL); 1321 /* M_PREPEND takes care of m_len, m_pkthdr.len for us */ 1322 1323 if (m->m_len < sizeof(*evl)) { 1324 m = m_pullup(m, sizeof(*evl)); 1325 if (m == NULL) 1326 return (NULL); 1327 } 1328 1329 /* 1330 * Transform the Ethernet header into an Ethernet header 1331 * with 802.1Q encapsulation. 1332 */ 1333 evl = mtod(m, struct ether_vlan_header *); 1334 bcopy((char *)evl + ETHER_VLAN_ENCAP_LEN, 1335 (char *)evl, ETHER_HDR_LEN - ETHER_TYPE_LEN); 1336 evl->evl_encap_proto = htons(ETHERTYPE_VLAN); 1337 evl->evl_tag = htons(tag); 1338 return (m); 1339 } 1340 1341 DECLARE_MODULE(ether, ether_mod, SI_SUB_INIT_IF, SI_ORDER_ANY); 1342 MODULE_VERSION(ether, 1); 1343