1 /* $OpenBSD: if_ether.c,v 1.79 2008/12/24 08:26:27 claudio Exp $ */ 2 /* $NetBSD: if_ether.c,v 1.31 1996/05/11 12:59:58 mycroft Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1988, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)if_ether.c 8.1 (Berkeley) 6/10/93 33 */ 34 35 /* 36 * Ethernet address resolution protocol. 37 * TODO: 38 * add "inuse/lock" bit (or ref. count) along with valid bit 39 */ 40 41 #ifdef INET 42 #include "carp.h" 43 44 #include "bridge.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/mbuf.h> 49 #include <sys/socket.h> 50 #include <sys/kernel.h> 51 #include <sys/syslog.h> 52 #include <sys/proc.h> 53 54 #include <net/if.h> 55 #include <net/if_dl.h> 56 #include <net/route.h> 57 #include <net/if_fddi.h> 58 #include <net/if_types.h> 59 60 #include <netinet/in.h> 61 #include <netinet/in_var.h> 62 #include <netinet/if_ether.h> 63 #if NCARP > 0 64 #include <netinet/ip_carp.h> 65 #endif 66 67 #define SIN(s) ((struct sockaddr_in *)s) 68 #define SDL(s) ((struct sockaddr_dl *)s) 69 #define SRP(s) ((struct sockaddr_inarp *)s) 70 71 /* 72 * ARP trailer negotiation. Trailer protocol is not IP specific, 73 * but ARP request/response use IP addresses. 74 */ 75 #define ETHERTYPE_IPTRAILERS ETHERTYPE_TRAIL 76 77 /* timer values */ 78 int arpt_prune = (5*60*1); /* walk list every 5 minutes */ 79 int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */ 80 int arpt_down = 20; /* once declared down, don't send for 20 secs */ 81 #define rt_expire rt_rmx.rmx_expire 82 83 void arptfree(struct llinfo_arp *); 84 void arptimer(void *); 85 struct llinfo_arp *arplookup(u_int32_t, int, int); 86 void in_arpinput(struct mbuf *); 87 88 LIST_HEAD(, llinfo_arp) llinfo_arp; 89 struct ifqueue arpintrq = {0, 0, 0, 50}; 90 int arp_inuse, arp_allocated, arp_intimer; 91 int arp_maxtries = 5; 92 int useloopback = 1; /* use loopback interface for local traffic */ 93 int arpinit_done; 94 int la_hold_total; 95 96 /* revarp state */ 97 struct in_addr myip, srv_ip; 98 int myip_initialized; 99 int revarp_in_progress; 100 struct ifnet *myip_ifp; 101 102 #ifdef DDB 103 #include <uvm/uvm_extern.h> 104 105 void db_print_sa(struct sockaddr *); 106 void db_print_ifa(struct ifaddr *); 107 void db_print_llinfo(caddr_t); 108 int db_show_radix_node(struct radix_node *, void *); 109 #endif 110 111 /* 112 * Timeout routine. Age arp_tab entries periodically. 113 */ 114 /* ARGSUSED */ 115 void 116 arptimer(arg) 117 void *arg; 118 { 119 struct timeout *to = (struct timeout *)arg; 120 int s; 121 struct llinfo_arp *la, *nla; 122 123 s = splsoftnet(); 124 timeout_add_sec(to, arpt_prune); 125 for (la = LIST_FIRST(&llinfo_arp); la != LIST_END(&llinfo_arp); 126 la = nla) { 127 struct rtentry *rt = la->la_rt; 128 129 nla = LIST_NEXT(la, la_list); 130 if (rt->rt_expire && rt->rt_expire <= time_second) 131 arptfree(la); /* timer has expired; clear */ 132 } 133 splx(s); 134 } 135 136 /* 137 * Parallel to llc_rtrequest. 138 */ 139 void 140 arp_rtrequest(req, rt, info) 141 int req; 142 struct rtentry *rt; 143 struct rt_addrinfo *info; 144 { 145 struct sockaddr *gate = rt->rt_gateway; 146 struct llinfo_arp *la = (struct llinfo_arp *)rt->rt_llinfo; 147 static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK}; 148 struct in_ifaddr *ia; 149 struct ifaddr *ifa; 150 struct mbuf *m; 151 152 if (!arpinit_done) { 153 static struct timeout arptimer_to; 154 155 arpinit_done = 1; 156 /* 157 * We generate expiration times from time.tv_sec 158 * so avoid accidently creating permanent routes. 159 */ 160 if (time_second == 0) { 161 time_second++; 162 } 163 164 timeout_set(&arptimer_to, arptimer, &arptimer_to); 165 timeout_add_sec(&arptimer_to, 1); 166 } 167 168 if (rt->rt_flags & RTF_GATEWAY) { 169 if (req != RTM_ADD) 170 return; 171 172 /* 173 * linklayers with particular link MTU limitation. it is a bit 174 * awkward to have FDDI handling here, we should split ARP from 175 * netinet/if_ether.c like NetBSD does. 176 */ 177 switch (rt->rt_ifp->if_type) { 178 case IFT_FDDI: 179 if (rt->rt_ifp->if_mtu > FDDIIPMTU) 180 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 181 break; 182 } 183 184 return; 185 } 186 187 switch (req) { 188 189 case RTM_ADD: 190 /* 191 * XXX: If this is a manually added route to interface 192 * such as older version of routed or gated might provide, 193 * restore cloning bit. 194 */ 195 if ((rt->rt_flags & RTF_HOST) == 0 && 196 SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff) 197 rt->rt_flags |= RTF_CLONING; 198 if (rt->rt_flags & RTF_CLONING) { 199 /* 200 * Case 1: This route should come from a route to iface. 201 */ 202 rt_setgate(rt, rt_key(rt), 203 (struct sockaddr *)&null_sdl, 0); 204 gate = rt->rt_gateway; 205 SDL(gate)->sdl_type = rt->rt_ifp->if_type; 206 SDL(gate)->sdl_index = rt->rt_ifp->if_index; 207 /* 208 * Give this route an expiration time, even though 209 * it's a "permanent" route, so that routes cloned 210 * from it do not need their expiration time set. 211 */ 212 rt->rt_expire = time_second; 213 /* 214 * linklayers with particular link MTU limitation. 215 */ 216 switch (rt->rt_ifp->if_type) { 217 case IFT_FDDI: 218 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 219 (rt->rt_rmx.rmx_mtu > FDDIIPMTU || 220 (rt->rt_rmx.rmx_mtu == 0 && 221 rt->rt_ifp->if_mtu > FDDIIPMTU))) 222 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 223 break; 224 } 225 break; 226 } 227 /* Announce a new entry if requested. */ 228 if (rt->rt_flags & RTF_ANNOUNCE) 229 arprequest(rt->rt_ifp, 230 &SIN(rt_key(rt))->sin_addr.s_addr, 231 &SIN(rt_key(rt))->sin_addr.s_addr, 232 (u_char *)LLADDR(SDL(gate))); 233 /*FALLTHROUGH*/ 234 case RTM_RESOLVE: 235 if (gate->sa_family != AF_LINK || 236 gate->sa_len < sizeof(null_sdl)) { 237 log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n"); 238 break; 239 } 240 SDL(gate)->sdl_type = rt->rt_ifp->if_type; 241 SDL(gate)->sdl_index = rt->rt_ifp->if_index; 242 if (la != 0) 243 break; /* This happens on a route change */ 244 /* 245 * Case 2: This route may come from cloning, or a manual route 246 * add with a LL address. 247 */ 248 R_Malloc(la, struct llinfo_arp *, sizeof(*la)); 249 rt->rt_llinfo = (caddr_t)la; 250 if (la == 0) { 251 log(LOG_DEBUG, "arp_rtrequest: malloc failed\n"); 252 break; 253 } 254 arp_inuse++, arp_allocated++; 255 Bzero(la, sizeof(*la)); 256 la->la_rt = rt; 257 rt->rt_flags |= RTF_LLINFO; 258 LIST_INSERT_HEAD(&llinfo_arp, la, la_list); 259 260 TAILQ_FOREACH(ia, &in_ifaddr, ia_list) { 261 if (ia->ia_ifp == rt->rt_ifp && 262 SIN(rt_key(rt))->sin_addr.s_addr == 263 (IA_SIN(ia))->sin_addr.s_addr) 264 break; 265 } 266 if (ia) { 267 /* 268 * This test used to be 269 * if (lo0ifp->if_flags & IFF_UP) 270 * It allowed local traffic to be forced through 271 * the hardware by configuring the loopback down. 272 * However, it causes problems during network 273 * configuration for boards that can't receive 274 * packets they send. It is now necessary to clear 275 * "useloopback" and remove the route to force 276 * traffic out to the hardware. 277 * 278 * In 4.4BSD, the above "if" statement checked 279 * rt->rt_ifa against rt_key(rt). It was changed 280 * to the current form so that we can provide a 281 * better support for multiple IPv4 addresses on a 282 * interface. 283 */ 284 rt->rt_expire = 0; 285 Bcopy(((struct arpcom *)rt->rt_ifp)->ac_enaddr, 286 LLADDR(SDL(gate)), 287 SDL(gate)->sdl_alen = ETHER_ADDR_LEN); 288 if (useloopback) 289 rt->rt_ifp = lo0ifp; 290 /* 291 * make sure to set rt->rt_ifa to the interface 292 * address we are using, otherwise we will have trouble 293 * with source address selection. 294 */ 295 ifa = &ia->ia_ifa; 296 if (ifa != rt->rt_ifa) { 297 IFAFREE(rt->rt_ifa); 298 ifa->ifa_refcnt++; 299 rt->rt_ifa = ifa; 300 } 301 } 302 break; 303 304 case RTM_DELETE: 305 if (la == 0) 306 break; 307 arp_inuse--; 308 LIST_REMOVE(la, la_list); 309 rt->rt_llinfo = 0; 310 rt->rt_flags &= ~RTF_LLINFO; 311 while ((m = la->la_hold_head) != NULL) { 312 la->la_hold_head = la->la_hold_head->m_nextpkt; 313 la_hold_total--; 314 m_freem(m); 315 } 316 Free((caddr_t)la); 317 } 318 } 319 320 /* 321 * Broadcast an ARP request. Caller specifies: 322 * - arp header source ip address 323 * - arp header target ip address 324 * - arp header source ethernet address 325 */ 326 void 327 arprequest(ifp, sip, tip, enaddr) 328 struct ifnet *ifp; 329 u_int32_t *sip, *tip; 330 u_int8_t *enaddr; 331 { 332 struct mbuf *m; 333 struct ether_header *eh; 334 struct ether_arp *ea; 335 struct sockaddr sa; 336 337 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 338 return; 339 m->m_len = sizeof(*ea); 340 m->m_pkthdr.len = sizeof(*ea); 341 MH_ALIGN(m, sizeof(*ea)); 342 ea = mtod(m, struct ether_arp *); 343 eh = (struct ether_header *)sa.sa_data; 344 bzero((caddr_t)ea, sizeof (*ea)); 345 bcopy((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost, 346 sizeof(eh->ether_dhost)); 347 eh->ether_type = htons(ETHERTYPE_ARP); /* if_output will not swap */ 348 ea->arp_hrd = htons(ARPHRD_ETHER); 349 ea->arp_pro = htons(ETHERTYPE_IP); 350 ea->arp_hln = sizeof(ea->arp_sha); /* hardware address length */ 351 ea->arp_pln = sizeof(ea->arp_spa); /* protocol address length */ 352 ea->arp_op = htons(ARPOP_REQUEST); 353 bcopy((caddr_t)enaddr, (caddr_t)eh->ether_shost, 354 sizeof(eh->ether_shost)); 355 bcopy((caddr_t)enaddr, (caddr_t)ea->arp_sha, sizeof(ea->arp_sha)); 356 bcopy((caddr_t)sip, (caddr_t)ea->arp_spa, sizeof(ea->arp_spa)); 357 bcopy((caddr_t)tip, (caddr_t)ea->arp_tpa, sizeof(ea->arp_tpa)); 358 sa.sa_family = pseudo_AF_HDRCMPLT; 359 sa.sa_len = sizeof(sa); 360 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); 361 } 362 363 /* 364 * Resolve an IP address into an ethernet address. If success, 365 * desten is filled in. If there is no entry in arptab, 366 * set one up and broadcast a request for the IP address. 367 * Hold onto this mbuf and resend it once the address 368 * is finally resolved. A return value of 1 indicates 369 * that desten has been filled in and the packet should be sent 370 * normally; a 0 return indicates that the packet has been 371 * taken over here, either now or for later transmission. 372 */ 373 int 374 arpresolve(ac, rt, m, dst, desten) 375 struct arpcom *ac; 376 struct rtentry *rt; 377 struct mbuf *m; 378 struct sockaddr *dst; 379 u_char *desten; 380 { 381 struct llinfo_arp *la; 382 struct sockaddr_dl *sdl; 383 struct mbuf *mh; 384 385 if (m->m_flags & M_BCAST) { /* broadcast */ 386 bcopy((caddr_t)etherbroadcastaddr, (caddr_t)desten, 387 sizeof(etherbroadcastaddr)); 388 return (1); 389 } 390 if (m->m_flags & M_MCAST) { /* multicast */ 391 ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten); 392 return (1); 393 } 394 if (rt) { 395 la = (struct llinfo_arp *)rt->rt_llinfo; 396 if (la == NULL) 397 log(LOG_DEBUG, "arpresolve: %s: route without link " 398 "local address\n", inet_ntoa(SIN(dst)->sin_addr)); 399 } else { 400 if ((la = arplookup(SIN(dst)->sin_addr.s_addr, 1, 0)) != NULL) 401 rt = la->la_rt; 402 else 403 log(LOG_DEBUG, 404 "arpresolve: %s: can't allocate llinfo\n", 405 inet_ntoa(SIN(dst)->sin_addr)); 406 } 407 if (la == 0 || rt == 0) { 408 m_freem(m); 409 return (0); 410 } 411 sdl = SDL(rt->rt_gateway); 412 /* 413 * Check the address family and length is valid, the address 414 * is resolved; otherwise, try to resolve. 415 */ 416 if ((rt->rt_expire == 0 || rt->rt_expire > time_second) && 417 sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) { 418 bcopy(LLADDR(sdl), desten, sdl->sdl_alen); 419 return 1; 420 } 421 if (((struct ifnet *)ac)->if_flags & IFF_NOARP) { 422 m_freem(m); 423 return 0; 424 } 425 426 /* 427 * There is an arptab entry, but no ethernet address 428 * response yet. Insert mbuf in hold queue if below limit 429 * if above the limit free the queue without queuing the new packet. 430 */ 431 if (la_hold_total < MAX_HOLD_TOTAL && la_hold_total < nmbclust / 64) { 432 if (la->la_hold_count >= MAX_HOLD_QUEUE) { 433 mh = la->la_hold_head; 434 la->la_hold_head = la->la_hold_head->m_nextpkt; 435 if (mh == la->la_hold_tail) 436 la->la_hold_tail = NULL; 437 la->la_hold_count--; 438 la_hold_total--; 439 m_freem(mh); 440 } 441 if (la->la_hold_tail == NULL) 442 la->la_hold_head = m; 443 else 444 la->la_hold_tail->m_nextpkt = m; 445 la->la_hold_tail = m; 446 la->la_hold_count++; 447 la_hold_total++; 448 } else { 449 while ((mh = la->la_hold_head) != NULL) { 450 la->la_hold_head = 451 la->la_hold_head->m_nextpkt; 452 la_hold_total--; 453 m_freem(mh); 454 } 455 la->la_hold_tail = NULL; 456 la->la_hold_count = 0; 457 m_freem(m); 458 } 459 460 /* 461 * Re-send the ARP request when appropriate. 462 */ 463 #ifdef DIAGNOSTIC 464 if (rt->rt_expire == 0) { 465 /* This should never happen. (Should it? -gwr) */ 466 printf("arpresolve: unresolved and rt_expire == 0\n"); 467 /* Set expiration time to now (expired). */ 468 rt->rt_expire = time_second; 469 } 470 #endif 471 if (rt->rt_expire) { 472 rt->rt_flags &= ~RTF_REJECT; 473 if (la->la_asked == 0 || rt->rt_expire != time_second) { 474 rt->rt_expire = time_second; 475 if (la->la_asked++ < arp_maxtries) 476 arprequest(&ac->ac_if, 477 &(SIN(rt->rt_ifa->ifa_addr)->sin_addr.s_addr), 478 &(SIN(dst)->sin_addr.s_addr), 479 #if NCARP > 0 480 (rt->rt_ifp->if_type == IFT_CARP) ? 481 ((struct arpcom *) rt->rt_ifp->if_softc 482 )->ac_enaddr : 483 #endif 484 ac->ac_enaddr); 485 else { 486 rt->rt_flags |= RTF_REJECT; 487 rt->rt_expire += arpt_down; 488 la->la_asked = 0; 489 while ((mh = la->la_hold_head) != NULL) { 490 la->la_hold_head = 491 la->la_hold_head->m_nextpkt; 492 la_hold_total--; 493 m_freem(mh); 494 } 495 la->la_hold_tail = NULL; 496 la->la_hold_count = 0; 497 } 498 } 499 } 500 return (0); 501 } 502 503 /* 504 * Common length and type checks are done here, 505 * then the protocol-specific routine is called. 506 */ 507 void 508 arpintr() 509 { 510 struct mbuf *m; 511 struct arphdr *ar; 512 int s, len; 513 514 for (;;) { 515 s = splnet(); 516 IF_DEQUEUE(&arpintrq, m); 517 splx(s); 518 if (m == NULL) 519 break; 520 #ifdef DIAGNOSTIC 521 if ((m->m_flags & M_PKTHDR) == 0) 522 panic("arpintr"); 523 #endif 524 525 len = sizeof(struct arphdr); 526 if (m->m_len < len && (m = m_pullup(m, len)) == NULL) 527 continue; 528 529 ar = mtod(m, struct arphdr *); 530 if (ntohs(ar->ar_hrd) != ARPHRD_ETHER) { 531 m_freem(m); 532 continue; 533 } 534 535 len += 2 * (ar->ar_hln + ar->ar_pln); 536 if (m->m_len < len && (m = m_pullup(m, len)) == NULL) 537 continue; 538 539 switch (ntohs(ar->ar_pro)) { 540 case ETHERTYPE_IP: 541 case ETHERTYPE_IPTRAILERS: 542 in_arpinput(m); 543 continue; 544 } 545 m_freem(m); 546 } 547 } 548 549 /* 550 * ARP for Internet protocols on Ethernet. 551 * Algorithm is that given in RFC 826. 552 * In addition, a sanity check is performed on the sender 553 * protocol address, to catch impersonators. 554 * We no longer handle negotiations for use of trailer protocol: 555 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent 556 * along with IP replies if we wanted trailers sent to us, 557 * and also sent them in response to IP replies. 558 * This allowed either end to announce the desire to receive 559 * trailer packets. 560 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, 561 * but formerly didn't normally send requests. 562 */ 563 void 564 in_arpinput(m) 565 struct mbuf *m; 566 { 567 struct ether_arp *ea; 568 struct arpcom *ac = (struct arpcom *)m->m_pkthdr.rcvif; 569 struct ether_header *eh; 570 struct llinfo_arp *la = 0; 571 struct rtentry *rt; 572 struct in_ifaddr *ia; 573 #if NBRIDGE > 0 574 struct in_ifaddr *bridge_ia = NULL; 575 #endif 576 struct sockaddr_dl *sdl; 577 struct sockaddr sa; 578 struct in_addr isaddr, itaddr, myaddr; 579 struct mbuf *mh, *mt; 580 u_int8_t *enaddr = NULL; 581 #if NCARP > 0 582 u_int8_t *ether_shost = NULL; 583 #endif 584 int op; 585 586 ea = mtod(m, struct ether_arp *); 587 op = ntohs(ea->arp_op); 588 if ((op != ARPOP_REQUEST) && (op != ARPOP_REPLY)) 589 goto out; 590 #if notyet 591 if ((op == ARPOP_REPLY) && (m->m_flags & (M_BCAST|M_MCAST))) { 592 log(LOG_ERR, 593 "arp: received reply to broadcast or multicast address\n"); 594 goto out; 595 } 596 #endif 597 598 bcopy((caddr_t)ea->arp_tpa, (caddr_t)&itaddr, sizeof(itaddr)); 599 bcopy((caddr_t)ea->arp_spa, (caddr_t)&isaddr, sizeof(isaddr)); 600 601 TAILQ_FOREACH(ia, &in_ifaddr, ia_list) { 602 if (itaddr.s_addr != ia->ia_addr.sin_addr.s_addr) 603 continue; 604 605 #if NCARP > 0 606 if (ia->ia_ifp->if_type == IFT_CARP && 607 ((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) == 608 (IFF_UP|IFF_RUNNING))) { 609 if (ia->ia_ifp == m->m_pkthdr.rcvif && 610 (op == ARPOP_REPLY || 611 carp_iamatch(ia, ea->arp_sha, 612 &enaddr, ðer_shost))) 613 break; 614 } else 615 #endif 616 if (ia->ia_ifp == m->m_pkthdr.rcvif) 617 break; 618 #if NBRIDGE > 0 619 /* 620 * If the interface we received the packet on 621 * is part of a bridge, check to see if we need 622 * to "bridge" the packet to ourselves at this 623 * layer. Note we still prefer a perfect match, 624 * but allow this weaker match if necessary. 625 */ 626 if (m->m_pkthdr.rcvif->if_bridge != NULL) { 627 if (m->m_pkthdr.rcvif->if_bridge == 628 ia->ia_ifp->if_bridge) 629 bridge_ia = ia; 630 #if NCARP > 0 631 else if (ia->ia_ifp->if_carpdev != NULL && 632 m->m_pkthdr.rcvif->if_bridge == 633 ia->ia_ifp->if_carpdev->if_bridge && 634 carp_iamatch(ia, ea->arp_sha, 635 &enaddr, ðer_shost)) 636 bridge_ia = ia; 637 #endif 638 } 639 #endif 640 } 641 642 #if NBRIDGE > 0 643 if (ia == NULL && bridge_ia != NULL) { 644 ia = bridge_ia; 645 ac = (struct arpcom *)bridge_ia->ia_ifp; 646 } 647 #endif 648 649 if (ia == NULL) { 650 TAILQ_FOREACH(ia, &in_ifaddr, ia_list) { 651 if (isaddr.s_addr != ia->ia_addr.sin_addr.s_addr) 652 continue; 653 if (ia->ia_ifp == m->m_pkthdr.rcvif) 654 break; 655 } 656 } 657 658 if (ia == NULL && m->m_pkthdr.rcvif->if_type != IFT_CARP) { 659 struct ifaddr *ifa; 660 661 TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrlist, ifa_list) { 662 if (ifa->ifa_addr->sa_family == AF_INET) 663 break; 664 } 665 if (ifa) 666 ia = (struct in_ifaddr *)ifa; 667 } 668 669 if (ia == NULL) 670 goto out; 671 672 if (!enaddr) 673 enaddr = ac->ac_enaddr; 674 myaddr = ia->ia_addr.sin_addr; 675 676 if (!bcmp((caddr_t)ea->arp_sha, enaddr, sizeof (ea->arp_sha))) 677 goto out; /* it's from me, ignore it. */ 678 if (ETHER_IS_MULTICAST (&ea->arp_sha[0])) 679 if (!bcmp((caddr_t)ea->arp_sha, (caddr_t)etherbroadcastaddr, 680 sizeof (ea->arp_sha))) { 681 log(LOG_ERR, "arp: ether address is broadcast for " 682 "IP address %s!\n", inet_ntoa(isaddr)); 683 goto out; 684 } 685 if (myaddr.s_addr && isaddr.s_addr == myaddr.s_addr) { 686 log(LOG_ERR, 687 "duplicate IP address %s sent from ethernet address %s\n", 688 inet_ntoa(isaddr), ether_sprintf(ea->arp_sha)); 689 itaddr = myaddr; 690 goto reply; 691 } 692 la = arplookup(isaddr.s_addr, itaddr.s_addr == myaddr.s_addr, 0); 693 if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) { 694 if (sdl->sdl_alen) { 695 if (bcmp(ea->arp_sha, LLADDR(sdl), sdl->sdl_alen)) { 696 if (rt->rt_flags & RTF_PERMANENT_ARP) { 697 log(LOG_WARNING, 698 "arp: attempt to overwrite permanent " 699 "entry for %s by %s on %s\n", 700 inet_ntoa(isaddr), 701 ether_sprintf(ea->arp_sha), 702 ac->ac_if.if_xname); 703 goto out; 704 } else if (rt->rt_ifp != &ac->ac_if) { 705 log(LOG_WARNING, 706 "arp: attempt to overwrite entry for %s " 707 "on %s by %s on %s\n", 708 inet_ntoa(isaddr), rt->rt_ifp->if_xname, 709 ether_sprintf(ea->arp_sha), 710 ac->ac_if.if_xname); 711 goto out; 712 } else { 713 log(LOG_INFO, 714 "arp info overwritten for %s by %s on %s\n", 715 inet_ntoa(isaddr), 716 ether_sprintf(ea->arp_sha), 717 ac->ac_if.if_xname); 718 rt->rt_expire = 1; /* no longer static */ 719 } 720 } 721 } else if (rt->rt_ifp != &ac->ac_if && !(ac->ac_if.if_bridge && 722 (rt->rt_ifp->if_bridge == ac->ac_if.if_bridge)) && 723 !(rt->rt_ifp->if_type == IFT_CARP && 724 rt->rt_ifp->if_carpdev == &ac->ac_if) && 725 !(ac->ac_if.if_type == IFT_CARP && 726 ac->ac_if.if_carpdev == rt->rt_ifp)) { 727 log(LOG_WARNING, 728 "arp: attempt to add entry for %s " 729 "on %s by %s on %s\n", 730 inet_ntoa(isaddr), rt->rt_ifp->if_xname, 731 ether_sprintf(ea->arp_sha), 732 ac->ac_if.if_xname); 733 goto out; 734 } 735 bcopy(ea->arp_sha, LLADDR(sdl), 736 sdl->sdl_alen = sizeof(ea->arp_sha)); 737 if (rt->rt_expire) 738 rt->rt_expire = time_second + arpt_keep; 739 rt->rt_flags &= ~RTF_REJECT; 740 la->la_asked = 0; 741 while ((mh = la->la_hold_head) != NULL) { 742 if ((la->la_hold_head = mh->m_nextpkt) == NULL) 743 la->la_hold_tail = NULL; 744 la->la_hold_count--; 745 la_hold_total--; 746 mt = la->la_hold_tail; 747 748 (*ac->ac_if.if_output)(&ac->ac_if, mh, rt_key(rt), rt); 749 750 if (la->la_hold_tail == mh) { 751 /* mbuf is back in queue. Discard. */ 752 la->la_hold_tail = mt; 753 if (la->la_hold_tail) 754 la->la_hold_tail->m_nextpkt = NULL; 755 else 756 la->la_hold_head = NULL; 757 la->la_hold_count--; 758 la_hold_total--; 759 m_freem(mh); 760 } 761 } 762 } 763 reply: 764 if (op != ARPOP_REQUEST) { 765 out: 766 m_freem(m); 767 return; 768 } 769 if (itaddr.s_addr == myaddr.s_addr) { 770 /* I am the target */ 771 bcopy(ea->arp_sha, ea->arp_tha, sizeof(ea->arp_sha)); 772 bcopy(enaddr, ea->arp_sha, sizeof(ea->arp_sha)); 773 } else { 774 la = arplookup(itaddr.s_addr, 0, SIN_PROXY); 775 if (la == 0) 776 goto out; 777 rt = la->la_rt; 778 if (rt->rt_ifp->if_type == IFT_CARP && 779 m->m_pkthdr.rcvif->if_type != IFT_CARP) 780 goto out; 781 bcopy(ea->arp_sha, ea->arp_tha, sizeof(ea->arp_sha)); 782 sdl = SDL(rt->rt_gateway); 783 bcopy(LLADDR(sdl), ea->arp_sha, sizeof(ea->arp_sha)); 784 } 785 786 bcopy(ea->arp_spa, ea->arp_tpa, sizeof(ea->arp_spa)); 787 bcopy(&itaddr, ea->arp_spa, sizeof(ea->arp_spa)); 788 ea->arp_op = htons(ARPOP_REPLY); 789 ea->arp_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 790 eh = (struct ether_header *)sa.sa_data; 791 bcopy(ea->arp_tha, eh->ether_dhost, sizeof(eh->ether_dhost)); 792 #if NCARP > 0 793 if (ether_shost) 794 enaddr = ether_shost; 795 #endif 796 bcopy(enaddr, eh->ether_shost, sizeof(eh->ether_shost)); 797 798 eh->ether_type = htons(ETHERTYPE_ARP); 799 sa.sa_family = pseudo_AF_HDRCMPLT; 800 sa.sa_len = sizeof(sa); 801 (*ac->ac_if.if_output)(&ac->ac_if, m, &sa, (struct rtentry *)0); 802 return; 803 } 804 805 /* 806 * Free an arp entry. 807 */ 808 void 809 arptfree(la) 810 struct llinfo_arp *la; 811 { 812 struct rtentry *rt = la->la_rt; 813 struct sockaddr_dl *sdl; 814 struct rt_addrinfo info; 815 816 if (rt == 0) 817 panic("arptfree"); 818 if (rt->rt_refcnt > 0 && (sdl = SDL(rt->rt_gateway)) && 819 sdl->sdl_family == AF_LINK) { 820 sdl->sdl_alen = 0; 821 la->la_asked = 0; 822 rt->rt_flags &= ~RTF_REJECT; 823 return; 824 } 825 bzero(&info, sizeof(info)); 826 info.rti_info[RTAX_DST] = rt_key(rt); 827 info.rti_info[RTAX_NETMASK] = rt_mask(rt); 828 829 rtrequest1(RTM_DELETE, &info, rt->rt_priority, NULL, 0); 830 } 831 832 /* 833 * Lookup or enter a new address in arptab. 834 */ 835 struct llinfo_arp * 836 arplookup(addr, create, proxy) 837 u_int32_t addr; 838 int create, proxy; 839 { 840 struct rtentry *rt; 841 static struct sockaddr_inarp sin; 842 843 sin.sin_len = sizeof(sin); 844 sin.sin_family = AF_INET; 845 sin.sin_addr.s_addr = addr; 846 sin.sin_other = proxy ? SIN_PROXY : 0; 847 rt = rtalloc1(sintosa(&sin), create, 0); 848 if (rt == 0) 849 return (0); 850 rt->rt_refcnt--; 851 if ((rt->rt_flags & RTF_GATEWAY) || (rt->rt_flags & RTF_LLINFO) == 0 || 852 rt->rt_gateway->sa_family != AF_LINK) { 853 if (create) { 854 if (rt->rt_refcnt <= 0 && 855 (rt->rt_flags & RTF_CLONED) != 0) { 856 struct rt_addrinfo info; 857 858 bzero(&info, sizeof(info)); 859 info.rti_info[RTAX_DST] = rt_key(rt); 860 info.rti_info[RTAX_GATEWAY] = rt->rt_gateway; 861 info.rti_info[RTAX_NETMASK] = rt_mask(rt); 862 863 rtrequest1(RTM_DELETE, &info, rt->rt_priority, 864 NULL, 0); 865 } 866 } 867 return (0); 868 } 869 return ((struct llinfo_arp *)rt->rt_llinfo); 870 } 871 872 int 873 arpioctl(cmd, data) 874 u_long cmd; 875 caddr_t data; 876 { 877 878 return (EOPNOTSUPP); 879 } 880 881 void 882 arp_ifinit(ac, ifa) 883 struct arpcom *ac; 884 struct ifaddr *ifa; 885 { 886 887 /* Warn the user if another station has this IP address. */ 888 arprequest(&ac->ac_if, 889 &(IA_SIN(ifa)->sin_addr.s_addr), 890 &(IA_SIN(ifa)->sin_addr.s_addr), 891 ac->ac_enaddr); 892 ifa->ifa_rtrequest = arp_rtrequest; 893 ifa->ifa_flags |= RTF_CLONING; 894 } 895 896 /* 897 * Called from Ethernet interrupt handlers 898 * when ether packet type ETHERTYPE_REVARP 899 * is received. Common length and type checks are done here, 900 * then the protocol-specific routine is called. 901 */ 902 void 903 revarpinput(m) 904 struct mbuf *m; 905 { 906 struct arphdr *ar; 907 908 if (m->m_len < sizeof(struct arphdr)) 909 goto out; 910 ar = mtod(m, struct arphdr *); 911 if (ntohs(ar->ar_hrd) != ARPHRD_ETHER) 912 goto out; 913 if (m->m_len < sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln)) 914 goto out; 915 switch (ntohs(ar->ar_pro)) { 916 917 case ETHERTYPE_IP: 918 case ETHERTYPE_IPTRAILERS: 919 in_revarpinput(m); 920 return; 921 922 default: 923 break; 924 } 925 out: 926 m_freem(m); 927 } 928 929 /* 930 * RARP for Internet protocols on Ethernet. 931 * Algorithm is that given in RFC 903. 932 * We are only using for bootstrap purposes to get an ip address for one of 933 * our interfaces. Thus we support no user-interface. 934 * 935 * Since the contents of the RARP reply are specific to the interface that 936 * sent the request, this code must ensure that they are properly associated. 937 * 938 * Note: also supports ARP via RARP packets, per the RFC. 939 */ 940 void 941 in_revarpinput(m) 942 struct mbuf *m; 943 { 944 struct ifnet *ifp; 945 struct ether_arp *ar; 946 int op; 947 948 ar = mtod(m, struct ether_arp *); 949 op = ntohs(ar->arp_op); 950 switch (op) { 951 case ARPOP_REQUEST: 952 case ARPOP_REPLY: /* per RFC */ 953 in_arpinput(m); 954 return; 955 case ARPOP_REVREPLY: 956 break; 957 case ARPOP_REVREQUEST: /* handled by rarpd(8) */ 958 default: 959 goto out; 960 } 961 if (!revarp_in_progress) 962 goto out; 963 ifp = m->m_pkthdr.rcvif; 964 if (ifp != myip_ifp) /* !same interface */ 965 goto out; 966 if (myip_initialized) 967 goto wake; 968 if (bcmp(ar->arp_tha, ((struct arpcom *)ifp)->ac_enaddr, 969 sizeof(ar->arp_tha))) 970 goto out; 971 bcopy((caddr_t)ar->arp_spa, (caddr_t)&srv_ip, sizeof(srv_ip)); 972 bcopy((caddr_t)ar->arp_tpa, (caddr_t)&myip, sizeof(myip)); 973 myip_initialized = 1; 974 wake: /* Do wakeup every time in case it was missed. */ 975 wakeup((caddr_t)&myip); 976 977 out: 978 m_freem(m); 979 } 980 981 /* 982 * Send a RARP request for the ip address of the specified interface. 983 * The request should be RFC 903-compliant. 984 */ 985 void 986 revarprequest(ifp) 987 struct ifnet *ifp; 988 { 989 struct sockaddr sa; 990 struct mbuf *m; 991 struct ether_header *eh; 992 struct ether_arp *ea; 993 struct arpcom *ac = (struct arpcom *)ifp; 994 995 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 996 return; 997 m->m_len = sizeof(*ea); 998 m->m_pkthdr.len = sizeof(*ea); 999 MH_ALIGN(m, sizeof(*ea)); 1000 ea = mtod(m, struct ether_arp *); 1001 eh = (struct ether_header *)sa.sa_data; 1002 bzero((caddr_t)ea, sizeof(*ea)); 1003 bcopy((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost, 1004 sizeof(eh->ether_dhost)); 1005 eh->ether_type = htons(ETHERTYPE_REVARP); 1006 ea->arp_hrd = htons(ARPHRD_ETHER); 1007 ea->arp_pro = htons(ETHERTYPE_IP); 1008 ea->arp_hln = sizeof(ea->arp_sha); /* hardware address length */ 1009 ea->arp_pln = sizeof(ea->arp_spa); /* protocol address length */ 1010 ea->arp_op = htons(ARPOP_REVREQUEST); 1011 bcopy((caddr_t)ac->ac_enaddr, (caddr_t)eh->ether_shost, 1012 sizeof(ea->arp_tha)); 1013 bcopy((caddr_t)ac->ac_enaddr, (caddr_t)ea->arp_sha, 1014 sizeof(ea->arp_sha)); 1015 bcopy((caddr_t)ac->ac_enaddr, (caddr_t)ea->arp_tha, 1016 sizeof(ea->arp_tha)); 1017 sa.sa_family = pseudo_AF_HDRCMPLT; 1018 sa.sa_len = sizeof(sa); 1019 ifp->if_output(ifp, m, &sa, (struct rtentry *)0); 1020 } 1021 1022 /* 1023 * RARP for the ip address of the specified interface, but also 1024 * save the ip address of the server that sent the answer. 1025 * Timeout if no response is received. 1026 */ 1027 int 1028 revarpwhoarewe(ifp, serv_in, clnt_in) 1029 struct ifnet *ifp; 1030 struct in_addr *serv_in; 1031 struct in_addr *clnt_in; 1032 { 1033 int result, count = 20; 1034 1035 if (myip_initialized) 1036 return EIO; 1037 1038 myip_ifp = ifp; 1039 revarp_in_progress = 1; 1040 while (count--) { 1041 revarprequest(ifp); 1042 result = tsleep((caddr_t)&myip, PSOCK, "revarp", hz/2); 1043 if (result != EWOULDBLOCK) 1044 break; 1045 } 1046 revarp_in_progress = 0; 1047 if (!myip_initialized) 1048 return ENETUNREACH; 1049 1050 bcopy((caddr_t)&srv_ip, serv_in, sizeof(*serv_in)); 1051 bcopy((caddr_t)&myip, clnt_in, sizeof(*clnt_in)); 1052 return 0; 1053 } 1054 1055 /* For compatibility: only saves interface address. */ 1056 int 1057 revarpwhoami(in, ifp) 1058 struct in_addr *in; 1059 struct ifnet *ifp; 1060 { 1061 struct in_addr server; 1062 return (revarpwhoarewe(ifp, &server, in)); 1063 } 1064 1065 1066 #ifdef DDB 1067 1068 #include <machine/db_machdep.h> 1069 #include <ddb/db_interface.h> 1070 #include <ddb/db_output.h> 1071 1072 void 1073 db_print_sa(sa) 1074 struct sockaddr *sa; 1075 { 1076 int len; 1077 u_char *p; 1078 1079 if (sa == 0) { 1080 db_printf("[NULL]"); 1081 return; 1082 } 1083 1084 p = (u_char *)sa; 1085 len = sa->sa_len; 1086 db_printf("["); 1087 while (len > 0) { 1088 db_printf("%d", *p); 1089 p++; 1090 len--; 1091 if (len) 1092 db_printf(","); 1093 } 1094 db_printf("]\n"); 1095 } 1096 1097 void 1098 db_print_ifa(ifa) 1099 struct ifaddr *ifa; 1100 { 1101 if (ifa == 0) 1102 return; 1103 db_printf(" ifa_addr="); 1104 db_print_sa(ifa->ifa_addr); 1105 db_printf(" ifa_dsta="); 1106 db_print_sa(ifa->ifa_dstaddr); 1107 db_printf(" ifa_mask="); 1108 db_print_sa(ifa->ifa_netmask); 1109 db_printf(" flags=0x%x, refcnt=%d, metric=%d\n", 1110 ifa->ifa_flags, ifa->ifa_refcnt, ifa->ifa_metric); 1111 } 1112 1113 void 1114 db_print_llinfo(li) 1115 caddr_t li; 1116 { 1117 struct llinfo_arp *la; 1118 1119 if (li == 0) 1120 return; 1121 la = (struct llinfo_arp *)li; 1122 db_printf(" la_rt=%p la_hold_head=%p, la_asked=0x%lx\n", 1123 la->la_rt, la->la_hold_head, la->la_asked); 1124 } 1125 1126 /* 1127 * Function to pass to rn_walktree(). 1128 * Return non-zero error to abort walk. 1129 */ 1130 int 1131 db_show_radix_node(rn, w) 1132 struct radix_node *rn; 1133 void *w; 1134 { 1135 struct rtentry *rt = (struct rtentry *)rn; 1136 1137 db_printf("rtentry=%p", rt); 1138 1139 db_printf(" flags=0x%x refcnt=%d use=%ld expire=%ld\n", 1140 rt->rt_flags, rt->rt_refcnt, rt->rt_use, rt->rt_expire); 1141 1142 db_printf(" key="); db_print_sa(rt_key(rt)); 1143 db_printf(" mask="); db_print_sa(rt_mask(rt)); 1144 db_printf(" gw="); db_print_sa(rt->rt_gateway); 1145 1146 db_printf(" ifp=%p ", rt->rt_ifp); 1147 if (rt->rt_ifp) 1148 db_printf("(%s)", rt->rt_ifp->if_xname); 1149 else 1150 db_printf("(NULL)"); 1151 1152 db_printf(" ifa=%p\n", rt->rt_ifa); 1153 db_print_ifa(rt->rt_ifa); 1154 1155 db_printf(" genmask="); db_print_sa(rt->rt_genmask); 1156 1157 db_printf(" gwroute=%p llinfo=%p\n", rt->rt_gwroute, rt->rt_llinfo); 1158 db_print_llinfo(rt->rt_llinfo); 1159 return (0); 1160 } 1161 1162 /* 1163 * Function to print all the route trees. 1164 * Use this from ddb: "call db_show_arptab" 1165 */ 1166 int 1167 db_show_arptab() 1168 { 1169 struct radix_node_head *rnh; 1170 rnh = rt_gettable(AF_INET, 0); 1171 db_printf("Route tree for AF_INET\n"); 1172 if (rnh == NULL) { 1173 db_printf(" (not initialized)\n"); 1174 return (0); 1175 } 1176 rn_walktree(rnh, db_show_radix_node, NULL); 1177 return (0); 1178 } 1179 #endif 1180 #endif /* INET */ 1181