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 54 #include <net/if.h> 55 #include <net/if_arp.h> 56 #include <net/netisr.h> 57 #include <net/route.h> 58 #include <net/if_llc.h> 59 #include <net/if_dl.h> 60 #include <net/if_types.h> 61 #include <net/bpf.h> 62 #include <net/ethernet.h> 63 #include <net/if_bridgevar.h> 64 #include <net/if_vlan_var.h> 65 #include <net/if_llatbl.h> 66 #include <net/pf_mtag.h> 67 #include <net/vnet.h> 68 69 #if defined(INET) || defined(INET6) 70 #include <netinet/in.h> 71 #include <netinet/in_var.h> 72 #include <netinet/if_ether.h> 73 #include <netinet/ip_var.h> 74 #include <netinet/ip_fw.h> 75 #include <netinet/ipfw/ip_fw_private.h> 76 #endif 77 #ifdef INET6 78 #include <netinet6/nd6.h> 79 #endif 80 81 #if defined(INET) || defined(INET6) 82 #ifdef DEV_CARP 83 #include <netinet/ip_carp.h> 84 #endif 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, int shared); 150 static VNET_DEFINE(int, ether_ipfw); 151 #define V_ether_ipfw VNET(ether_ipfw) 152 #endif 153 154 155 /* 156 * Ethernet output routine. 157 * Encapsulate a packet of type family for the local net. 158 * Use trailer local net encapsulation if enough data in first 159 * packet leaves a multiple of 512 bytes of data in remainder. 160 */ 161 int 162 ether_output(struct ifnet *ifp, struct mbuf *m, 163 struct sockaddr *dst, struct route *ro) 164 { 165 short type; 166 int error = 0, hdrcmplt = 0; 167 u_char esrc[ETHER_ADDR_LEN], edst[ETHER_ADDR_LEN]; 168 struct llentry *lle = NULL; 169 struct rtentry *rt0 = NULL; 170 struct ether_header *eh; 171 struct pf_mtag *t; 172 int loop_copy = 1; 173 int hlen; /* link layer header length */ 174 175 if (ro != NULL) { 176 if (!(m->m_flags & (M_BCAST | M_MCAST))) 177 lle = ro->ro_lle; 178 rt0 = ro->ro_rt; 179 } 180 #ifdef MAC 181 error = mac_ifnet_check_transmit(ifp, m); 182 if (error) 183 senderr(error); 184 #endif 185 186 M_PROFILE(m); 187 if (ifp->if_flags & IFF_MONITOR) 188 senderr(ENETDOWN); 189 if (!((ifp->if_flags & IFF_UP) && 190 (ifp->if_drv_flags & IFF_DRV_RUNNING))) 191 senderr(ENETDOWN); 192 193 hlen = ETHER_HDR_LEN; 194 switch (dst->sa_family) { 195 #ifdef INET 196 case AF_INET: 197 if (lle != NULL && (lle->la_flags & LLE_VALID)) 198 memcpy(edst, &lle->ll_addr.mac16, sizeof(edst)); 199 else 200 error = arpresolve(ifp, rt0, m, dst, edst, &lle); 201 if (error) 202 return (error == EWOULDBLOCK ? 0 : error); 203 type = htons(ETHERTYPE_IP); 204 break; 205 case AF_ARP: 206 { 207 struct arphdr *ah; 208 ah = mtod(m, struct arphdr *); 209 ah->ar_hrd = htons(ARPHRD_ETHER); 210 211 loop_copy = 0; /* if this is for us, don't do it */ 212 213 switch(ntohs(ah->ar_op)) { 214 case ARPOP_REVREQUEST: 215 case ARPOP_REVREPLY: 216 type = htons(ETHERTYPE_REVARP); 217 break; 218 case ARPOP_REQUEST: 219 case ARPOP_REPLY: 220 default: 221 type = htons(ETHERTYPE_ARP); 222 break; 223 } 224 225 if (m->m_flags & M_BCAST) 226 bcopy(ifp->if_broadcastaddr, edst, ETHER_ADDR_LEN); 227 else 228 bcopy(ar_tha(ah), edst, ETHER_ADDR_LEN); 229 230 } 231 break; 232 #endif 233 #ifdef INET6 234 case AF_INET6: 235 if (lle != NULL && (lle->la_flags & LLE_VALID)) 236 memcpy(edst, &lle->ll_addr.mac16, sizeof(edst)); 237 else 238 error = nd6_storelladdr(ifp, m, dst, (u_char *)edst, &lle); 239 if (error) 240 return error; 241 type = htons(ETHERTYPE_IPV6); 242 break; 243 #endif 244 #ifdef IPX 245 case AF_IPX: 246 if (ef_outputp) { 247 error = ef_outputp(ifp, &m, dst, &type, &hlen); 248 if (error) 249 goto bad; 250 } else 251 type = htons(ETHERTYPE_IPX); 252 bcopy((caddr_t)&(((struct sockaddr_ipx *)dst)->sipx_addr.x_host), 253 (caddr_t)edst, sizeof (edst)); 254 break; 255 #endif 256 #ifdef NETATALK 257 case AF_APPLETALK: 258 { 259 struct at_ifaddr *aa; 260 261 if ((aa = at_ifawithnet((struct sockaddr_at *)dst)) == NULL) 262 senderr(EHOSTUNREACH); /* XXX */ 263 if (!aarpresolve(ifp, m, (struct sockaddr_at *)dst, edst)) { 264 ifa_free(&aa->aa_ifa); 265 return (0); 266 } 267 /* 268 * In the phase 2 case, need to prepend an mbuf for the llc header. 269 */ 270 if ( aa->aa_flags & AFA_PHASE2 ) { 271 struct llc llc; 272 273 ifa_free(&aa->aa_ifa); 274 M_PREPEND(m, LLC_SNAPFRAMELEN, M_DONTWAIT); 275 if (m == NULL) 276 senderr(ENOBUFS); 277 llc.llc_dsap = llc.llc_ssap = LLC_SNAP_LSAP; 278 llc.llc_control = LLC_UI; 279 bcopy(at_org_code, llc.llc_snap_org_code, sizeof(at_org_code)); 280 llc.llc_snap_ether_type = htons( ETHERTYPE_AT ); 281 bcopy(&llc, mtod(m, caddr_t), LLC_SNAPFRAMELEN); 282 type = htons(m->m_pkthdr.len); 283 hlen = LLC_SNAPFRAMELEN + ETHER_HDR_LEN; 284 } else { 285 ifa_free(&aa->aa_ifa); 286 type = htons(ETHERTYPE_AT); 287 } 288 break; 289 } 290 #endif /* NETATALK */ 291 292 case pseudo_AF_HDRCMPLT: 293 hdrcmplt = 1; 294 eh = (struct ether_header *)dst->sa_data; 295 (void)memcpy(esrc, eh->ether_shost, sizeof (esrc)); 296 /* FALLTHROUGH */ 297 298 case AF_UNSPEC: 299 loop_copy = 0; /* if this is for us, don't do it */ 300 eh = (struct ether_header *)dst->sa_data; 301 (void)memcpy(edst, eh->ether_dhost, sizeof (edst)); 302 type = eh->ether_type; 303 break; 304 305 default: 306 if_printf(ifp, "can't handle af%d\n", dst->sa_family); 307 senderr(EAFNOSUPPORT); 308 } 309 310 if (lle != NULL && (lle->la_flags & LLE_IFADDR)) { 311 int csum_flags = 0; 312 if (m->m_pkthdr.csum_flags & CSUM_IP) 313 csum_flags |= (CSUM_IP_CHECKED|CSUM_IP_VALID); 314 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) 315 csum_flags |= (CSUM_DATA_VALID|CSUM_PSEUDO_HDR); 316 if (m->m_pkthdr.csum_flags & CSUM_SCTP) 317 csum_flags |= CSUM_SCTP_VALID; 318 m->m_pkthdr.csum_flags |= csum_flags; 319 m->m_pkthdr.csum_data = 0xffff; 320 return (if_simloop(ifp, m, dst->sa_family, 0)); 321 } 322 323 /* 324 * Add local net header. If no space in first mbuf, 325 * allocate another. 326 */ 327 M_PREPEND(m, ETHER_HDR_LEN, M_DONTWAIT); 328 if (m == NULL) 329 senderr(ENOBUFS); 330 eh = mtod(m, struct ether_header *); 331 (void)memcpy(&eh->ether_type, &type, 332 sizeof(eh->ether_type)); 333 (void)memcpy(eh->ether_dhost, edst, sizeof (edst)); 334 if (hdrcmplt) 335 (void)memcpy(eh->ether_shost, esrc, 336 sizeof(eh->ether_shost)); 337 else 338 (void)memcpy(eh->ether_shost, IF_LLADDR(ifp), 339 sizeof(eh->ether_shost)); 340 341 /* 342 * If a simplex interface, and the packet is being sent to our 343 * Ethernet address or a broadcast address, loopback a copy. 344 * XXX To make a simplex device behave exactly like a duplex 345 * device, we should copy in the case of sending to our own 346 * ethernet address (thus letting the original actually appear 347 * on the wire). However, we don't do that here for security 348 * reasons and compatibility with the original behavior. 349 */ 350 if ((ifp->if_flags & IFF_SIMPLEX) && loop_copy && 351 ((t = pf_find_mtag(m)) == NULL || !t->routed)) { 352 int csum_flags = 0; 353 354 if (m->m_pkthdr.csum_flags & CSUM_IP) 355 csum_flags |= (CSUM_IP_CHECKED|CSUM_IP_VALID); 356 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) 357 csum_flags |= (CSUM_DATA_VALID|CSUM_PSEUDO_HDR); 358 if (m->m_pkthdr.csum_flags & CSUM_SCTP) 359 csum_flags |= CSUM_SCTP_VALID; 360 361 if (m->m_flags & M_BCAST) { 362 struct mbuf *n; 363 364 /* 365 * Because if_simloop() modifies the packet, we need a 366 * writable copy through m_dup() instead of a readonly 367 * one as m_copy[m] would give us. The alternative would 368 * be to modify if_simloop() to handle the readonly mbuf, 369 * but performancewise it is mostly equivalent (trading 370 * extra data copying vs. extra locking). 371 * 372 * XXX This is a local workaround. A number of less 373 * often used kernel parts suffer from the same bug. 374 * See PR kern/105943 for a proposed general solution. 375 */ 376 if ((n = m_dup(m, M_DONTWAIT)) != NULL) { 377 n->m_pkthdr.csum_flags |= csum_flags; 378 if (csum_flags & CSUM_DATA_VALID) 379 n->m_pkthdr.csum_data = 0xffff; 380 (void)if_simloop(ifp, n, dst->sa_family, hlen); 381 } else 382 ifp->if_iqdrops++; 383 } else if (bcmp(eh->ether_dhost, eh->ether_shost, 384 ETHER_ADDR_LEN) == 0) { 385 m->m_pkthdr.csum_flags |= csum_flags; 386 if (csum_flags & CSUM_DATA_VALID) 387 m->m_pkthdr.csum_data = 0xffff; 388 (void) if_simloop(ifp, m, dst->sa_family, hlen); 389 return (0); /* XXX */ 390 } 391 } 392 393 /* 394 * Bridges require special output handling. 395 */ 396 if (ifp->if_bridge) { 397 BRIDGE_OUTPUT(ifp, m, error); 398 return (error); 399 } 400 401 #if defined(INET) || defined(INET6) 402 #ifdef DEV_CARP 403 if (ifp->if_carp && 404 (error = carp_output(ifp, m, dst, NULL))) 405 goto bad; 406 #endif 407 #endif 408 409 /* Handle ng_ether(4) processing, if any */ 410 if (IFP2AC(ifp)->ac_netgraph != NULL) { 411 KASSERT(ng_ether_output_p != NULL, 412 ("ng_ether_output_p is NULL")); 413 if ((error = (*ng_ether_output_p)(ifp, &m)) != 0) { 414 bad: if (m != NULL) 415 m_freem(m); 416 return (error); 417 } 418 if (m == NULL) 419 return (0); 420 } 421 422 /* Continue with link-layer output */ 423 return ether_output_frame(ifp, m); 424 } 425 426 /* 427 * Ethernet link layer output routine to send a raw frame to the device. 428 * 429 * This assumes that the 14 byte Ethernet header is present and contiguous 430 * in the first mbuf (if BRIDGE'ing). 431 */ 432 int 433 ether_output_frame(struct ifnet *ifp, struct mbuf *m) 434 { 435 #if defined(INET) || defined(INET6) 436 437 if (V_ip_fw_chk_ptr && V_ether_ipfw != 0) { 438 if (ether_ipfw_chk(&m, ifp, 0) == 0) { 439 if (m) { 440 m_freem(m); 441 return EACCES; /* pkt dropped */ 442 } else 443 return 0; /* consumed e.g. in a pipe */ 444 } 445 } 446 #endif 447 448 /* 449 * Queue message on interface, update output statistics if 450 * successful, and start output if interface not yet active. 451 */ 452 return ((ifp->if_transmit)(ifp, m)); 453 } 454 455 #if defined(INET) || defined(INET6) 456 /* 457 * ipfw processing for ethernet packets (in and out). 458 * The second parameter is NULL from ether_demux, and ifp from 459 * ether_output_frame. 460 */ 461 int 462 ether_ipfw_chk(struct mbuf **m0, struct ifnet *dst, int shared) 463 { 464 struct ether_header *eh; 465 struct ether_header save_eh; 466 struct mbuf *m; 467 int i; 468 struct ip_fw_args args; 469 struct m_tag *mtag; 470 471 /* fetch start point from rule, if any */ 472 mtag = m_tag_locate(*m0, MTAG_IPFW_RULE, 0, NULL); 473 if (mtag == NULL) { 474 args.rule.slot = 0; 475 } else { 476 /* dummynet packet, already partially processed */ 477 struct ipfw_rule_ref *r; 478 479 /* XXX can we free it after use ? */ 480 mtag->m_tag_id = PACKET_TAG_NONE; 481 r = (struct ipfw_rule_ref *)(mtag + 1); 482 if (r->info & IPFW_ONEPASS) 483 return (1); 484 args.rule = *r; 485 } 486 487 /* 488 * I need some amt of data to be contiguous, and in case others need 489 * the packet (shared==1) also better be in the first mbuf. 490 */ 491 m = *m0; 492 i = min( m->m_pkthdr.len, max_protohdr); 493 if ( shared || m->m_len < i) { 494 m = m_pullup(m, i); 495 if (m == NULL) { 496 *m0 = m; 497 return 0; 498 } 499 } 500 eh = mtod(m, struct ether_header *); 501 save_eh = *eh; /* save copy for restore below */ 502 m_adj(m, ETHER_HDR_LEN); /* strip ethernet header */ 503 504 args.m = m; /* the packet we are looking at */ 505 args.oif = dst; /* destination, if any */ 506 args.next_hop = NULL; /* we do not support forward yet */ 507 args.eh = &save_eh; /* MAC header for bridged/MAC packets */ 508 args.inp = NULL; /* used by ipfw uid/gid/jail rules */ 509 i = V_ip_fw_chk_ptr(&args); 510 m = args.m; 511 if (m != NULL) { 512 /* 513 * Restore Ethernet header, as needed, in case the 514 * mbuf chain was replaced by ipfw. 515 */ 516 M_PREPEND(m, ETHER_HDR_LEN, M_DONTWAIT); 517 if (m == NULL) { 518 *m0 = m; 519 return 0; 520 } 521 if (eh != mtod(m, struct ether_header *)) 522 bcopy(&save_eh, mtod(m, struct ether_header *), 523 ETHER_HDR_LEN); 524 } 525 *m0 = m; 526 527 if (i == IP_FW_DENY) /* drop */ 528 return 0; 529 530 KASSERT(m != NULL, ("ether_ipfw_chk: m is NULL")); 531 532 if (i == IP_FW_PASS) /* a PASS rule. */ 533 return 1; 534 535 if (ip_dn_io_ptr && (i == IP_FW_DUMMYNET)) { 536 int dir; 537 /* 538 * Pass the pkt to dummynet, which consumes it. 539 * If shared, make a copy and keep the original. 540 */ 541 if (shared) { 542 m = m_copypacket(m, M_DONTWAIT); 543 if (m == NULL) 544 return 0; 545 } else { 546 /* 547 * Pass the original to dummynet and 548 * nothing back to the caller 549 */ 550 *m0 = NULL ; 551 } 552 dir = PROTO_LAYER2 | (dst ? DIR_OUT : DIR_IN); 553 ip_dn_io_ptr(&m, dir, &args); 554 return 0; 555 } 556 /* 557 * XXX at some point add support for divert/forward actions. 558 * If none of the above matches, we have to drop the pkt. 559 */ 560 return 0; 561 } 562 #endif 563 564 /* 565 * Process a received Ethernet packet; the packet is in the 566 * mbuf chain m with the ethernet header at the front. 567 */ 568 static void 569 ether_input(struct ifnet *ifp, struct mbuf *m) 570 { 571 struct ether_header *eh; 572 u_short etype; 573 574 if ((ifp->if_flags & IFF_UP) == 0) { 575 m_freem(m); 576 return; 577 } 578 #ifdef DIAGNOSTIC 579 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 580 if_printf(ifp, "discard frame at !IFF_DRV_RUNNING\n"); 581 m_freem(m); 582 return; 583 } 584 #endif 585 /* 586 * Do consistency checks to verify assumptions 587 * made by code past this point. 588 */ 589 if ((m->m_flags & M_PKTHDR) == 0) { 590 if_printf(ifp, "discard frame w/o packet header\n"); 591 ifp->if_ierrors++; 592 m_freem(m); 593 return; 594 } 595 if (m->m_len < ETHER_HDR_LEN) { 596 /* XXX maybe should pullup? */ 597 if_printf(ifp, "discard frame w/o leading ethernet " 598 "header (len %u pkt len %u)\n", 599 m->m_len, m->m_pkthdr.len); 600 ifp->if_ierrors++; 601 m_freem(m); 602 return; 603 } 604 eh = mtod(m, struct ether_header *); 605 etype = ntohs(eh->ether_type); 606 if (m->m_pkthdr.rcvif == NULL) { 607 if_printf(ifp, "discard frame w/o interface pointer\n"); 608 ifp->if_ierrors++; 609 m_freem(m); 610 return; 611 } 612 #ifdef DIAGNOSTIC 613 if (m->m_pkthdr.rcvif != ifp) { 614 if_printf(ifp, "Warning, frame marked as received on %s\n", 615 m->m_pkthdr.rcvif->if_xname); 616 } 617 #endif 618 619 CURVNET_SET_QUIET(ifp->if_vnet); 620 621 if (ETHER_IS_MULTICAST(eh->ether_dhost)) { 622 if (ETHER_IS_BROADCAST(eh->ether_dhost)) 623 m->m_flags |= M_BCAST; 624 else 625 m->m_flags |= M_MCAST; 626 ifp->if_imcasts++; 627 } 628 629 #ifdef MAC 630 /* 631 * Tag the mbuf with an appropriate MAC label before any other 632 * consumers can get to it. 633 */ 634 mac_ifnet_create_mbuf(ifp, m); 635 #endif 636 637 /* 638 * Give bpf a chance at the packet. 639 */ 640 ETHER_BPF_MTAP(ifp, m); 641 642 /* 643 * If the CRC is still on the packet, trim it off. We do this once 644 * and once only in case we are re-entered. Nothing else on the 645 * Ethernet receive path expects to see the FCS. 646 */ 647 if (m->m_flags & M_HASFCS) { 648 m_adj(m, -ETHER_CRC_LEN); 649 m->m_flags &= ~M_HASFCS; 650 } 651 652 ifp->if_ibytes += m->m_pkthdr.len; 653 654 /* Allow monitor mode to claim this frame, after stats are updated. */ 655 if (ifp->if_flags & IFF_MONITOR) { 656 m_freem(m); 657 CURVNET_RESTORE(); 658 return; 659 } 660 661 /* Handle input from a lagg(4) port */ 662 if (ifp->if_type == IFT_IEEE8023ADLAG) { 663 KASSERT(lagg_input_p != NULL, 664 ("%s: if_lagg not loaded!", __func__)); 665 m = (*lagg_input_p)(ifp, m); 666 if (m != NULL) 667 ifp = m->m_pkthdr.rcvif; 668 else 669 return; 670 } 671 672 /* 673 * If the hardware did not process an 802.1Q tag, do this now, 674 * to allow 802.1P priority frames to be passed to the main input 675 * path correctly. 676 * TODO: Deal with Q-in-Q frames, but not arbitrary nesting levels. 677 */ 678 if ((m->m_flags & M_VLANTAG) == 0 && etype == ETHERTYPE_VLAN) { 679 struct ether_vlan_header *evl; 680 681 if (m->m_len < sizeof(*evl) && 682 (m = m_pullup(m, sizeof(*evl))) == NULL) { 683 #ifdef DIAGNOSTIC 684 if_printf(ifp, "cannot pullup VLAN header\n"); 685 #endif 686 ifp->if_ierrors++; 687 m_freem(m); 688 return; 689 } 690 691 evl = mtod(m, struct ether_vlan_header *); 692 m->m_pkthdr.ether_vtag = ntohs(evl->evl_tag); 693 m->m_flags |= M_VLANTAG; 694 695 bcopy((char *)evl, (char *)evl + ETHER_VLAN_ENCAP_LEN, 696 ETHER_HDR_LEN - ETHER_TYPE_LEN); 697 m_adj(m, ETHER_VLAN_ENCAP_LEN); 698 } 699 700 /* Allow ng_ether(4) to claim this frame. */ 701 if (IFP2AC(ifp)->ac_netgraph != NULL) { 702 KASSERT(ng_ether_input_p != NULL, 703 ("%s: ng_ether_input_p is NULL", __func__)); 704 m->m_flags &= ~M_PROMISC; 705 (*ng_ether_input_p)(ifp, &m); 706 if (m == NULL) { 707 CURVNET_RESTORE(); 708 return; 709 } 710 } 711 712 /* 713 * Allow if_bridge(4) to claim this frame. 714 * The BRIDGE_INPUT() macro will update ifp if the bridge changed it 715 * and the frame should be delivered locally. 716 */ 717 if (ifp->if_bridge != NULL) { 718 m->m_flags &= ~M_PROMISC; 719 BRIDGE_INPUT(ifp, m); 720 if (m == NULL) { 721 CURVNET_RESTORE(); 722 return; 723 } 724 } 725 726 #if defined(INET) || defined(INET6) 727 #ifdef DEV_CARP 728 /* 729 * Clear M_PROMISC on frame so that carp(4) will see it when the 730 * mbuf flows up to Layer 3. 731 * FreeBSD's implementation of carp(4) uses the inprotosw 732 * to dispatch IPPROTO_CARP. carp(4) also allocates its own 733 * Ethernet addresses of the form 00:00:5e:00:01:xx, which 734 * is outside the scope of the M_PROMISC test below. 735 * TODO: Maintain a hash table of ethernet addresses other than 736 * ether_dhost which may be active on this ifp. 737 */ 738 if (ifp->if_carp && carp_forus(ifp->if_carp, eh->ether_dhost)) { 739 m->m_flags &= ~M_PROMISC; 740 } else 741 #endif 742 #endif 743 { 744 /* 745 * If the frame received was not for our MAC address, set the 746 * M_PROMISC flag on the mbuf chain. The frame may need to 747 * be seen by the rest of the Ethernet input path in case of 748 * re-entry (e.g. bridge, vlan, netgraph) but should not be 749 * seen by upper protocol layers. 750 */ 751 if (!ETHER_IS_MULTICAST(eh->ether_dhost) && 752 bcmp(IF_LLADDR(ifp), eh->ether_dhost, ETHER_ADDR_LEN) != 0) 753 m->m_flags |= M_PROMISC; 754 } 755 756 /* First chunk of an mbuf contains good entropy */ 757 if (harvest.ethernet) 758 random_harvest(m, 16, 3, 0, RANDOM_NET); 759 760 ether_demux(ifp, m); 761 CURVNET_RESTORE(); 762 } 763 764 /* 765 * Upper layer processing for a received Ethernet packet. 766 */ 767 void 768 ether_demux(struct ifnet *ifp, struct mbuf *m) 769 { 770 struct ether_header *eh; 771 int isr; 772 u_short ether_type; 773 #if defined(NETATALK) 774 struct llc *l; 775 #endif 776 777 KASSERT(ifp != NULL, ("%s: NULL interface pointer", __func__)); 778 779 #if defined(INET) || defined(INET6) 780 /* 781 * Allow dummynet and/or ipfw to claim the frame. 782 * Do not do this for PROMISC frames in case we are re-entered. 783 */ 784 if (V_ip_fw_chk_ptr && V_ether_ipfw != 0 && !(m->m_flags & M_PROMISC)) { 785 if (ether_ipfw_chk(&m, NULL, 0) == 0) { 786 if (m) 787 m_freem(m); /* dropped; free mbuf chain */ 788 return; /* consumed */ 789 } 790 } 791 #endif 792 eh = mtod(m, struct ether_header *); 793 ether_type = ntohs(eh->ether_type); 794 795 /* 796 * If this frame has a VLAN tag other than 0, call vlan_input() 797 * if its module is loaded. Otherwise, drop. 798 */ 799 if ((m->m_flags & M_VLANTAG) && 800 EVL_VLANOFTAG(m->m_pkthdr.ether_vtag) != 0) { 801 if (ifp->if_vlantrunk == NULL) { 802 ifp->if_noproto++; 803 m_freem(m); 804 return; 805 } 806 KASSERT(vlan_input_p != NULL,("%s: VLAN not loaded!", 807 __func__)); 808 /* Clear before possibly re-entering ether_input(). */ 809 m->m_flags &= ~M_PROMISC; 810 (*vlan_input_p)(ifp, m); 811 return; 812 } 813 814 /* 815 * Pass promiscuously received frames to the upper layer if the user 816 * requested this by setting IFF_PPROMISC. Otherwise, drop them. 817 */ 818 if ((ifp->if_flags & IFF_PPROMISC) == 0 && (m->m_flags & M_PROMISC)) { 819 m_freem(m); 820 return; 821 } 822 823 /* 824 * Reset layer specific mbuf flags to avoid confusing upper layers. 825 * Strip off Ethernet header. 826 */ 827 m->m_flags &= ~M_VLANTAG; 828 m->m_flags &= ~(M_PROTOFLAGS); 829 m_adj(m, ETHER_HDR_LEN); 830 831 /* 832 * Dispatch frame to upper layer. 833 */ 834 switch (ether_type) { 835 #ifdef INET 836 case ETHERTYPE_IP: 837 if ((m = ip_fastforward(m)) == NULL) 838 return; 839 isr = NETISR_IP; 840 break; 841 842 case ETHERTYPE_ARP: 843 if (ifp->if_flags & IFF_NOARP) { 844 /* Discard packet if ARP is disabled on interface */ 845 m_freem(m); 846 return; 847 } 848 isr = NETISR_ARP; 849 break; 850 #endif 851 #ifdef IPX 852 case ETHERTYPE_IPX: 853 if (ef_inputp && ef_inputp(ifp, eh, m) == 0) 854 return; 855 isr = NETISR_IPX; 856 break; 857 #endif 858 #ifdef INET6 859 case ETHERTYPE_IPV6: 860 isr = NETISR_IPV6; 861 break; 862 #endif 863 #ifdef NETATALK 864 case ETHERTYPE_AT: 865 isr = NETISR_ATALK1; 866 break; 867 case ETHERTYPE_AARP: 868 isr = NETISR_AARP; 869 break; 870 #endif /* NETATALK */ 871 default: 872 #ifdef IPX 873 if (ef_inputp && ef_inputp(ifp, eh, m) == 0) 874 return; 875 #endif /* IPX */ 876 #if defined(NETATALK) 877 if (ether_type > ETHERMTU) 878 goto discard; 879 l = mtod(m, struct llc *); 880 if (l->llc_dsap == LLC_SNAP_LSAP && 881 l->llc_ssap == LLC_SNAP_LSAP && 882 l->llc_control == LLC_UI) { 883 if (bcmp(&(l->llc_snap_org_code)[0], at_org_code, 884 sizeof(at_org_code)) == 0 && 885 ntohs(l->llc_snap_ether_type) == ETHERTYPE_AT) { 886 m_adj(m, LLC_SNAPFRAMELEN); 887 isr = NETISR_ATALK2; 888 break; 889 } 890 if (bcmp(&(l->llc_snap_org_code)[0], aarp_org_code, 891 sizeof(aarp_org_code)) == 0 && 892 ntohs(l->llc_snap_ether_type) == ETHERTYPE_AARP) { 893 m_adj(m, LLC_SNAPFRAMELEN); 894 isr = NETISR_AARP; 895 break; 896 } 897 } 898 #endif /* NETATALK */ 899 goto discard; 900 } 901 netisr_dispatch(isr, m); 902 return; 903 904 discard: 905 /* 906 * Packet is to be discarded. If netgraph is present, 907 * hand the packet to it for last chance processing; 908 * otherwise dispose of it. 909 */ 910 if (IFP2AC(ifp)->ac_netgraph != NULL) { 911 KASSERT(ng_ether_input_orphan_p != NULL, 912 ("ng_ether_input_orphan_p is NULL")); 913 /* 914 * Put back the ethernet header so netgraph has a 915 * consistent view of inbound packets. 916 */ 917 M_PREPEND(m, ETHER_HDR_LEN, M_DONTWAIT); 918 (*ng_ether_input_orphan_p)(ifp, m); 919 return; 920 } 921 m_freem(m); 922 } 923 924 /* 925 * Convert Ethernet address to printable (loggable) representation. 926 * This routine is for compatibility; it's better to just use 927 * 928 * printf("%6D", <pointer to address>, ":"); 929 * 930 * since there's no static buffer involved. 931 */ 932 char * 933 ether_sprintf(const u_char *ap) 934 { 935 static char etherbuf[18]; 936 snprintf(etherbuf, sizeof (etherbuf), "%6D", ap, ":"); 937 return (etherbuf); 938 } 939 940 /* 941 * Perform common duties while attaching to interface list 942 */ 943 void 944 ether_ifattach(struct ifnet *ifp, const u_int8_t *lla) 945 { 946 int i; 947 struct ifaddr *ifa; 948 struct sockaddr_dl *sdl; 949 950 ifp->if_addrlen = ETHER_ADDR_LEN; 951 ifp->if_hdrlen = ETHER_HDR_LEN; 952 if_attach(ifp); 953 ifp->if_mtu = ETHERMTU; 954 ifp->if_output = ether_output; 955 ifp->if_input = ether_input; 956 ifp->if_resolvemulti = ether_resolvemulti; 957 if (ifp->if_baudrate == 0) 958 ifp->if_baudrate = IF_Mbps(10); /* just a default */ 959 ifp->if_broadcastaddr = etherbroadcastaddr; 960 961 ifa = ifp->if_addr; 962 KASSERT(ifa != NULL, ("%s: no lladdr!\n", __func__)); 963 sdl = (struct sockaddr_dl *)ifa->ifa_addr; 964 sdl->sdl_type = IFT_ETHER; 965 sdl->sdl_alen = ifp->if_addrlen; 966 bcopy(lla, LLADDR(sdl), ifp->if_addrlen); 967 968 bpfattach(ifp, DLT_EN10MB, ETHER_HDR_LEN); 969 if (ng_ether_attach_p != NULL) 970 (*ng_ether_attach_p)(ifp); 971 972 /* Announce Ethernet MAC address if non-zero. */ 973 for (i = 0; i < ifp->if_addrlen; i++) 974 if (lla[i] != 0) 975 break; 976 if (i != ifp->if_addrlen) 977 if_printf(ifp, "Ethernet address: %6D\n", lla, ":"); 978 } 979 980 /* 981 * Perform common duties while detaching an Ethernet interface 982 */ 983 void 984 ether_ifdetach(struct ifnet *ifp) 985 { 986 if (IFP2AC(ifp)->ac_netgraph != NULL) { 987 KASSERT(ng_ether_detach_p != NULL, 988 ("ng_ether_detach_p is NULL")); 989 (*ng_ether_detach_p)(ifp); 990 } 991 992 bpfdetach(ifp); 993 if_detach(ifp); 994 } 995 996 SYSCTL_DECL(_net_link); 997 SYSCTL_NODE(_net_link, IFT_ETHER, ether, CTLFLAG_RW, 0, "Ethernet"); 998 #if defined(INET) || defined(INET6) 999 SYSCTL_VNET_INT(_net_link_ether, OID_AUTO, ipfw, CTLFLAG_RW, 1000 &VNET_NAME(ether_ipfw), 0, "Pass ether pkts through firewall"); 1001 #endif 1002 1003 #if 0 1004 /* 1005 * This is for reference. We have a table-driven version 1006 * of the little-endian crc32 generator, which is faster 1007 * than the double-loop. 1008 */ 1009 uint32_t 1010 ether_crc32_le(const uint8_t *buf, size_t len) 1011 { 1012 size_t i; 1013 uint32_t crc; 1014 int bit; 1015 uint8_t data; 1016 1017 crc = 0xffffffff; /* initial value */ 1018 1019 for (i = 0; i < len; i++) { 1020 for (data = *buf++, bit = 0; bit < 8; bit++, data >>= 1) { 1021 carry = (crc ^ data) & 1; 1022 crc >>= 1; 1023 if (carry) 1024 crc = (crc ^ ETHER_CRC_POLY_LE); 1025 } 1026 } 1027 1028 return (crc); 1029 } 1030 #else 1031 uint32_t 1032 ether_crc32_le(const uint8_t *buf, size_t len) 1033 { 1034 static const uint32_t crctab[] = { 1035 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac, 1036 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c, 1037 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c, 1038 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c 1039 }; 1040 size_t i; 1041 uint32_t crc; 1042 1043 crc = 0xffffffff; /* initial value */ 1044 1045 for (i = 0; i < len; i++) { 1046 crc ^= buf[i]; 1047 crc = (crc >> 4) ^ crctab[crc & 0xf]; 1048 crc = (crc >> 4) ^ crctab[crc & 0xf]; 1049 } 1050 1051 return (crc); 1052 } 1053 #endif 1054 1055 uint32_t 1056 ether_crc32_be(const uint8_t *buf, size_t len) 1057 { 1058 size_t i; 1059 uint32_t crc, carry; 1060 int bit; 1061 uint8_t data; 1062 1063 crc = 0xffffffff; /* initial value */ 1064 1065 for (i = 0; i < len; i++) { 1066 for (data = *buf++, bit = 0; bit < 8; bit++, data >>= 1) { 1067 carry = ((crc & 0x80000000) ? 1 : 0) ^ (data & 0x01); 1068 crc <<= 1; 1069 if (carry) 1070 crc = (crc ^ ETHER_CRC_POLY_BE) | carry; 1071 } 1072 } 1073 1074 return (crc); 1075 } 1076 1077 int 1078 ether_ioctl(struct ifnet *ifp, u_long command, caddr_t data) 1079 { 1080 struct ifaddr *ifa = (struct ifaddr *) data; 1081 struct ifreq *ifr = (struct ifreq *) data; 1082 int error = 0; 1083 1084 switch (command) { 1085 case SIOCSIFADDR: 1086 ifp->if_flags |= IFF_UP; 1087 1088 switch (ifa->ifa_addr->sa_family) { 1089 #ifdef INET 1090 case AF_INET: 1091 ifp->if_init(ifp->if_softc); /* before arpwhohas */ 1092 arp_ifinit(ifp, ifa); 1093 break; 1094 #endif 1095 #ifdef IPX 1096 /* 1097 * XXX - This code is probably wrong 1098 */ 1099 case AF_IPX: 1100 { 1101 struct ipx_addr *ina = &(IA_SIPX(ifa)->sipx_addr); 1102 1103 if (ipx_nullhost(*ina)) 1104 ina->x_host = 1105 *(union ipx_host *) 1106 IF_LLADDR(ifp); 1107 else { 1108 bcopy((caddr_t) ina->x_host.c_host, 1109 (caddr_t) IF_LLADDR(ifp), 1110 ETHER_ADDR_LEN); 1111 } 1112 1113 /* 1114 * Set new address 1115 */ 1116 ifp->if_init(ifp->if_softc); 1117 break; 1118 } 1119 #endif 1120 default: 1121 ifp->if_init(ifp->if_softc); 1122 break; 1123 } 1124 break; 1125 1126 case SIOCGIFADDR: 1127 { 1128 struct sockaddr *sa; 1129 1130 sa = (struct sockaddr *) & ifr->ifr_data; 1131 bcopy(IF_LLADDR(ifp), 1132 (caddr_t) sa->sa_data, ETHER_ADDR_LEN); 1133 } 1134 break; 1135 1136 case SIOCSIFMTU: 1137 /* 1138 * Set the interface MTU. 1139 */ 1140 if (ifr->ifr_mtu > ETHERMTU) { 1141 error = EINVAL; 1142 } else { 1143 ifp->if_mtu = ifr->ifr_mtu; 1144 } 1145 break; 1146 default: 1147 error = EINVAL; /* XXX netbsd has ENOTTY??? */ 1148 break; 1149 } 1150 return (error); 1151 } 1152 1153 static int 1154 ether_resolvemulti(struct ifnet *ifp, struct sockaddr **llsa, 1155 struct sockaddr *sa) 1156 { 1157 struct sockaddr_dl *sdl; 1158 #ifdef INET 1159 struct sockaddr_in *sin; 1160 #endif 1161 #ifdef INET6 1162 struct sockaddr_in6 *sin6; 1163 #endif 1164 u_char *e_addr; 1165 1166 switch(sa->sa_family) { 1167 case AF_LINK: 1168 /* 1169 * No mapping needed. Just check that it's a valid MC address. 1170 */ 1171 sdl = (struct sockaddr_dl *)sa; 1172 e_addr = LLADDR(sdl); 1173 if (!ETHER_IS_MULTICAST(e_addr)) 1174 return EADDRNOTAVAIL; 1175 *llsa = 0; 1176 return 0; 1177 1178 #ifdef INET 1179 case AF_INET: 1180 sin = (struct sockaddr_in *)sa; 1181 if (!IN_MULTICAST(ntohl(sin->sin_addr.s_addr))) 1182 return EADDRNOTAVAIL; 1183 sdl = malloc(sizeof *sdl, M_IFMADDR, 1184 M_NOWAIT|M_ZERO); 1185 if (sdl == NULL) 1186 return ENOMEM; 1187 sdl->sdl_len = sizeof *sdl; 1188 sdl->sdl_family = AF_LINK; 1189 sdl->sdl_index = ifp->if_index; 1190 sdl->sdl_type = IFT_ETHER; 1191 sdl->sdl_alen = ETHER_ADDR_LEN; 1192 e_addr = LLADDR(sdl); 1193 ETHER_MAP_IP_MULTICAST(&sin->sin_addr, e_addr); 1194 *llsa = (struct sockaddr *)sdl; 1195 return 0; 1196 #endif 1197 #ifdef INET6 1198 case AF_INET6: 1199 sin6 = (struct sockaddr_in6 *)sa; 1200 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) { 1201 /* 1202 * An IP6 address of 0 means listen to all 1203 * of the Ethernet multicast address used for IP6. 1204 * (This is used for multicast routers.) 1205 */ 1206 ifp->if_flags |= IFF_ALLMULTI; 1207 *llsa = 0; 1208 return 0; 1209 } 1210 if (!IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 1211 return EADDRNOTAVAIL; 1212 sdl = malloc(sizeof *sdl, M_IFMADDR, 1213 M_NOWAIT|M_ZERO); 1214 if (sdl == NULL) 1215 return (ENOMEM); 1216 sdl->sdl_len = sizeof *sdl; 1217 sdl->sdl_family = AF_LINK; 1218 sdl->sdl_index = ifp->if_index; 1219 sdl->sdl_type = IFT_ETHER; 1220 sdl->sdl_alen = ETHER_ADDR_LEN; 1221 e_addr = LLADDR(sdl); 1222 ETHER_MAP_IPV6_MULTICAST(&sin6->sin6_addr, e_addr); 1223 *llsa = (struct sockaddr *)sdl; 1224 return 0; 1225 #endif 1226 1227 default: 1228 /* 1229 * Well, the text isn't quite right, but it's the name 1230 * that counts... 1231 */ 1232 return EAFNOSUPPORT; 1233 } 1234 } 1235 1236 static void* 1237 ether_alloc(u_char type, struct ifnet *ifp) 1238 { 1239 struct arpcom *ac; 1240 1241 ac = malloc(sizeof(struct arpcom), M_ARPCOM, M_WAITOK | M_ZERO); 1242 ac->ac_ifp = ifp; 1243 1244 return (ac); 1245 } 1246 1247 static void 1248 ether_free(void *com, u_char type) 1249 { 1250 1251 free(com, M_ARPCOM); 1252 } 1253 1254 static int 1255 ether_modevent(module_t mod, int type, void *data) 1256 { 1257 1258 switch (type) { 1259 case MOD_LOAD: 1260 if_register_com_alloc(IFT_ETHER, ether_alloc, ether_free); 1261 break; 1262 case MOD_UNLOAD: 1263 if_deregister_com_alloc(IFT_ETHER); 1264 break; 1265 default: 1266 return EOPNOTSUPP; 1267 } 1268 1269 return (0); 1270 } 1271 1272 static moduledata_t ether_mod = { 1273 "ether", 1274 ether_modevent, 1275 0 1276 }; 1277 1278 void 1279 ether_vlan_mtap(struct bpf_if *bp, struct mbuf *m, void *data, u_int dlen) 1280 { 1281 struct ether_vlan_header vlan; 1282 struct mbuf mv, mb; 1283 1284 KASSERT((m->m_flags & M_VLANTAG) != 0, 1285 ("%s: vlan information not present", __func__)); 1286 KASSERT(m->m_len >= sizeof(struct ether_header), 1287 ("%s: mbuf not large enough for header", __func__)); 1288 bcopy(mtod(m, char *), &vlan, sizeof(struct ether_header)); 1289 vlan.evl_proto = vlan.evl_encap_proto; 1290 vlan.evl_encap_proto = htons(ETHERTYPE_VLAN); 1291 vlan.evl_tag = htons(m->m_pkthdr.ether_vtag); 1292 m->m_len -= sizeof(struct ether_header); 1293 m->m_data += sizeof(struct ether_header); 1294 /* 1295 * If a data link has been supplied by the caller, then we will need to 1296 * re-create a stack allocated mbuf chain with the following structure: 1297 * 1298 * (1) mbuf #1 will contain the supplied data link 1299 * (2) mbuf #2 will contain the vlan header 1300 * (3) mbuf #3 will contain the original mbuf's packet data 1301 * 1302 * Otherwise, submit the packet and vlan header via bpf_mtap2(). 1303 */ 1304 if (data != NULL) { 1305 mv.m_next = m; 1306 mv.m_data = (caddr_t)&vlan; 1307 mv.m_len = sizeof(vlan); 1308 mb.m_next = &mv; 1309 mb.m_data = data; 1310 mb.m_len = dlen; 1311 bpf_mtap(bp, &mb); 1312 } else 1313 bpf_mtap2(bp, &vlan, sizeof(vlan), m); 1314 m->m_len += sizeof(struct ether_header); 1315 m->m_data -= sizeof(struct ether_header); 1316 } 1317 1318 struct mbuf * 1319 ether_vlanencap(struct mbuf *m, uint16_t tag) 1320 { 1321 struct ether_vlan_header *evl; 1322 1323 M_PREPEND(m, ETHER_VLAN_ENCAP_LEN, M_DONTWAIT); 1324 if (m == NULL) 1325 return (NULL); 1326 /* M_PREPEND takes care of m_len, m_pkthdr.len for us */ 1327 1328 if (m->m_len < sizeof(*evl)) { 1329 m = m_pullup(m, sizeof(*evl)); 1330 if (m == NULL) 1331 return (NULL); 1332 } 1333 1334 /* 1335 * Transform the Ethernet header into an Ethernet header 1336 * with 802.1Q encapsulation. 1337 */ 1338 evl = mtod(m, struct ether_vlan_header *); 1339 bcopy((char *)evl + ETHER_VLAN_ENCAP_LEN, 1340 (char *)evl, ETHER_HDR_LEN - ETHER_TYPE_LEN); 1341 evl->evl_encap_proto = htons(ETHERTYPE_VLAN); 1342 evl->evl_tag = htons(tag); 1343 return (m); 1344 } 1345 1346 DECLARE_MODULE(ether, ether_mod, SI_SUB_INIT_IF, SI_ORDER_ANY); 1347 MODULE_VERSION(ether, 1); 1348