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