1 /* $OpenBSD: if_ether.c,v 1.80 2009/06/05 00:05:22 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, u_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, 204 rt->rt_ifp->if_rdomain); 205 gate = rt->rt_gateway; 206 SDL(gate)->sdl_type = rt->rt_ifp->if_type; 207 SDL(gate)->sdl_index = rt->rt_ifp->if_index; 208 /* 209 * Give this route an expiration time, even though 210 * it's a "permanent" route, so that routes cloned 211 * from it do not need their expiration time set. 212 */ 213 rt->rt_expire = time_second; 214 /* 215 * linklayers with particular link MTU limitation. 216 */ 217 switch (rt->rt_ifp->if_type) { 218 case IFT_FDDI: 219 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 220 (rt->rt_rmx.rmx_mtu > FDDIIPMTU || 221 (rt->rt_rmx.rmx_mtu == 0 && 222 rt->rt_ifp->if_mtu > FDDIIPMTU))) 223 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 224 break; 225 } 226 break; 227 } 228 /* Announce a new entry if requested. */ 229 if (rt->rt_flags & RTF_ANNOUNCE) 230 arprequest(rt->rt_ifp, 231 &SIN(rt_key(rt))->sin_addr.s_addr, 232 &SIN(rt_key(rt))->sin_addr.s_addr, 233 (u_char *)LLADDR(SDL(gate))); 234 /*FALLTHROUGH*/ 235 case RTM_RESOLVE: 236 if (gate->sa_family != AF_LINK || 237 gate->sa_len < sizeof(null_sdl)) { 238 log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n"); 239 break; 240 } 241 SDL(gate)->sdl_type = rt->rt_ifp->if_type; 242 SDL(gate)->sdl_index = rt->rt_ifp->if_index; 243 if (la != 0) 244 break; /* This happens on a route change */ 245 /* 246 * Case 2: This route may come from cloning, or a manual route 247 * add with a LL address. 248 */ 249 R_Malloc(la, struct llinfo_arp *, sizeof(*la)); 250 rt->rt_llinfo = (caddr_t)la; 251 if (la == 0) { 252 log(LOG_DEBUG, "arp_rtrequest: malloc failed\n"); 253 break; 254 } 255 arp_inuse++, arp_allocated++; 256 Bzero(la, sizeof(*la)); 257 la->la_rt = rt; 258 rt->rt_flags |= RTF_LLINFO; 259 LIST_INSERT_HEAD(&llinfo_arp, la, la_list); 260 261 TAILQ_FOREACH(ia, &in_ifaddr, ia_list) { 262 if (ia->ia_ifp == rt->rt_ifp && 263 SIN(rt_key(rt))->sin_addr.s_addr == 264 (IA_SIN(ia))->sin_addr.s_addr) 265 break; 266 } 267 if (ia) { 268 /* 269 * This test used to be 270 * if (lo0ifp->if_flags & IFF_UP) 271 * It allowed local traffic to be forced through 272 * the hardware by configuring the loopback down. 273 * However, it causes problems during network 274 * configuration for boards that can't receive 275 * packets they send. It is now necessary to clear 276 * "useloopback" and remove the route to force 277 * traffic out to the hardware. 278 * 279 * In 4.4BSD, the above "if" statement checked 280 * rt->rt_ifa against rt_key(rt). It was changed 281 * to the current form so that we can provide a 282 * better support for multiple IPv4 addresses on a 283 * interface. 284 */ 285 rt->rt_expire = 0; 286 Bcopy(((struct arpcom *)rt->rt_ifp)->ac_enaddr, 287 LLADDR(SDL(gate)), 288 SDL(gate)->sdl_alen = ETHER_ADDR_LEN); 289 if (useloopback) 290 rt->rt_ifp = lo0ifp; 291 /* 292 * make sure to set rt->rt_ifa to the interface 293 * address we are using, otherwise we will have trouble 294 * with source address selection. 295 */ 296 ifa = &ia->ia_ifa; 297 if (ifa != rt->rt_ifa) { 298 IFAFREE(rt->rt_ifa); 299 ifa->ifa_refcnt++; 300 rt->rt_ifa = ifa; 301 } 302 } 303 break; 304 305 case RTM_DELETE: 306 if (la == 0) 307 break; 308 arp_inuse--; 309 LIST_REMOVE(la, la_list); 310 rt->rt_llinfo = 0; 311 rt->rt_flags &= ~RTF_LLINFO; 312 while ((m = la->la_hold_head) != NULL) { 313 la->la_hold_head = la->la_hold_head->m_nextpkt; 314 la_hold_total--; 315 m_freem(m); 316 } 317 Free((caddr_t)la); 318 } 319 } 320 321 /* 322 * Broadcast an ARP request. Caller specifies: 323 * - arp header source ip address 324 * - arp header target ip address 325 * - arp header source ethernet address 326 */ 327 void 328 arprequest(ifp, sip, tip, enaddr) 329 struct ifnet *ifp; 330 u_int32_t *sip, *tip; 331 u_int8_t *enaddr; 332 { 333 struct mbuf *m; 334 struct ether_header *eh; 335 struct ether_arp *ea; 336 struct sockaddr sa; 337 338 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 339 return; 340 m->m_len = sizeof(*ea); 341 m->m_pkthdr.len = sizeof(*ea); 342 m->m_pkthdr.rdomain = ifp->if_rdomain; 343 MH_ALIGN(m, sizeof(*ea)); 344 ea = mtod(m, struct ether_arp *); 345 eh = (struct ether_header *)sa.sa_data; 346 bzero((caddr_t)ea, sizeof (*ea)); 347 bcopy((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost, 348 sizeof(eh->ether_dhost)); 349 eh->ether_type = htons(ETHERTYPE_ARP); /* if_output will not swap */ 350 ea->arp_hrd = htons(ARPHRD_ETHER); 351 ea->arp_pro = htons(ETHERTYPE_IP); 352 ea->arp_hln = sizeof(ea->arp_sha); /* hardware address length */ 353 ea->arp_pln = sizeof(ea->arp_spa); /* protocol address length */ 354 ea->arp_op = htons(ARPOP_REQUEST); 355 bcopy((caddr_t)enaddr, (caddr_t)eh->ether_shost, 356 sizeof(eh->ether_shost)); 357 bcopy((caddr_t)enaddr, (caddr_t)ea->arp_sha, sizeof(ea->arp_sha)); 358 bcopy((caddr_t)sip, (caddr_t)ea->arp_spa, sizeof(ea->arp_spa)); 359 bcopy((caddr_t)tip, (caddr_t)ea->arp_tpa, sizeof(ea->arp_tpa)); 360 sa.sa_family = pseudo_AF_HDRCMPLT; 361 sa.sa_len = sizeof(sa); 362 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); 363 } 364 365 /* 366 * Resolve an IP address into an ethernet address. If success, 367 * desten is filled in. If there is no entry in arptab, 368 * set one up and broadcast a request for the IP address. 369 * Hold onto this mbuf and resend it once the address 370 * is finally resolved. A return value of 1 indicates 371 * that desten has been filled in and the packet should be sent 372 * normally; a 0 return indicates that the packet has been 373 * taken over here, either now or for later transmission. 374 */ 375 int 376 arpresolve(ac, rt, m, dst, desten) 377 struct arpcom *ac; 378 struct rtentry *rt; 379 struct mbuf *m; 380 struct sockaddr *dst; 381 u_char *desten; 382 { 383 struct llinfo_arp *la; 384 struct sockaddr_dl *sdl; 385 struct mbuf *mh; 386 387 if (m->m_flags & M_BCAST) { /* broadcast */ 388 bcopy((caddr_t)etherbroadcastaddr, (caddr_t)desten, 389 sizeof(etherbroadcastaddr)); 390 return (1); 391 } 392 if (m->m_flags & M_MCAST) { /* multicast */ 393 ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten); 394 return (1); 395 } 396 if (rt) { 397 la = (struct llinfo_arp *)rt->rt_llinfo; 398 if (la == NULL) 399 log(LOG_DEBUG, "arpresolve: %s: route without link " 400 "local address\n", inet_ntoa(SIN(dst)->sin_addr)); 401 } else { 402 if ((la = arplookup(SIN(dst)->sin_addr.s_addr, 1, 0, 403 ac->ac_if.if_rdomain)) != NULL) 404 rt = la->la_rt; 405 else 406 log(LOG_DEBUG, 407 "arpresolve: %s: can't allocate llinfo\n", 408 inet_ntoa(SIN(dst)->sin_addr)); 409 } 410 if (la == 0 || rt == 0) { 411 m_freem(m); 412 return (0); 413 } 414 sdl = SDL(rt->rt_gateway); 415 /* 416 * Check the address family and length is valid, the address 417 * is resolved; otherwise, try to resolve. 418 */ 419 if ((rt->rt_expire == 0 || rt->rt_expire > time_second) && 420 sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) { 421 bcopy(LLADDR(sdl), desten, sdl->sdl_alen); 422 return 1; 423 } 424 if (((struct ifnet *)ac)->if_flags & IFF_NOARP) { 425 m_freem(m); 426 return 0; 427 } 428 429 /* 430 * There is an arptab entry, but no ethernet address 431 * response yet. Insert mbuf in hold queue if below limit 432 * if above the limit free the queue without queuing the new packet. 433 */ 434 if (la_hold_total < MAX_HOLD_TOTAL && la_hold_total < nmbclust / 64) { 435 if (la->la_hold_count >= MAX_HOLD_QUEUE) { 436 mh = la->la_hold_head; 437 la->la_hold_head = la->la_hold_head->m_nextpkt; 438 if (mh == la->la_hold_tail) 439 la->la_hold_tail = NULL; 440 la->la_hold_count--; 441 la_hold_total--; 442 m_freem(mh); 443 } 444 if (la->la_hold_tail == NULL) 445 la->la_hold_head = m; 446 else 447 la->la_hold_tail->m_nextpkt = m; 448 la->la_hold_tail = m; 449 la->la_hold_count++; 450 la_hold_total++; 451 } else { 452 while ((mh = la->la_hold_head) != NULL) { 453 la->la_hold_head = 454 la->la_hold_head->m_nextpkt; 455 la_hold_total--; 456 m_freem(mh); 457 } 458 la->la_hold_tail = NULL; 459 la->la_hold_count = 0; 460 m_freem(m); 461 } 462 463 /* 464 * Re-send the ARP request when appropriate. 465 */ 466 #ifdef DIAGNOSTIC 467 if (rt->rt_expire == 0) { 468 /* This should never happen. (Should it? -gwr) */ 469 printf("arpresolve: unresolved and rt_expire == 0\n"); 470 /* Set expiration time to now (expired). */ 471 rt->rt_expire = time_second; 472 } 473 #endif 474 if (rt->rt_expire) { 475 rt->rt_flags &= ~RTF_REJECT; 476 if (la->la_asked == 0 || rt->rt_expire != time_second) { 477 rt->rt_expire = time_second; 478 if (la->la_asked++ < arp_maxtries) 479 arprequest(&ac->ac_if, 480 &(SIN(rt->rt_ifa->ifa_addr)->sin_addr.s_addr), 481 &(SIN(dst)->sin_addr.s_addr), 482 #if NCARP > 0 483 (rt->rt_ifp->if_type == IFT_CARP) ? 484 ((struct arpcom *) rt->rt_ifp->if_softc 485 )->ac_enaddr : 486 #endif 487 ac->ac_enaddr); 488 else { 489 rt->rt_flags |= RTF_REJECT; 490 rt->rt_expire += arpt_down; 491 la->la_asked = 0; 492 while ((mh = la->la_hold_head) != NULL) { 493 la->la_hold_head = 494 la->la_hold_head->m_nextpkt; 495 la_hold_total--; 496 m_freem(mh); 497 } 498 la->la_hold_tail = NULL; 499 la->la_hold_count = 0; 500 } 501 } 502 } 503 return (0); 504 } 505 506 /* 507 * Common length and type checks are done here, 508 * then the protocol-specific routine is called. 509 */ 510 void 511 arpintr() 512 { 513 struct mbuf *m; 514 struct arphdr *ar; 515 int s, len; 516 517 for (;;) { 518 s = splnet(); 519 IF_DEQUEUE(&arpintrq, m); 520 splx(s); 521 if (m == NULL) 522 break; 523 #ifdef DIAGNOSTIC 524 if ((m->m_flags & M_PKTHDR) == 0) 525 panic("arpintr"); 526 #endif 527 528 len = sizeof(struct arphdr); 529 if (m->m_len < len && (m = m_pullup(m, len)) == NULL) 530 continue; 531 532 ar = mtod(m, struct arphdr *); 533 if (ntohs(ar->ar_hrd) != ARPHRD_ETHER) { 534 m_freem(m); 535 continue; 536 } 537 538 len += 2 * (ar->ar_hln + ar->ar_pln); 539 if (m->m_len < len && (m = m_pullup(m, len)) == NULL) 540 continue; 541 542 switch (ntohs(ar->ar_pro)) { 543 case ETHERTYPE_IP: 544 case ETHERTYPE_IPTRAILERS: 545 in_arpinput(m); 546 continue; 547 } 548 m_freem(m); 549 } 550 } 551 552 /* 553 * ARP for Internet protocols on Ethernet. 554 * Algorithm is that given in RFC 826. 555 * In addition, a sanity check is performed on the sender 556 * protocol address, to catch impersonators. 557 * We no longer handle negotiations for use of trailer protocol: 558 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent 559 * along with IP replies if we wanted trailers sent to us, 560 * and also sent them in response to IP replies. 561 * This allowed either end to announce the desire to receive 562 * trailer packets. 563 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, 564 * but formerly didn't normally send requests. 565 */ 566 void 567 in_arpinput(m) 568 struct mbuf *m; 569 { 570 struct ether_arp *ea; 571 struct arpcom *ac = (struct arpcom *)m->m_pkthdr.rcvif; 572 struct ether_header *eh; 573 struct llinfo_arp *la = 0; 574 struct rtentry *rt; 575 struct in_ifaddr *ia; 576 #if NBRIDGE > 0 577 struct in_ifaddr *bridge_ia = NULL; 578 #endif 579 struct sockaddr_dl *sdl; 580 struct sockaddr sa; 581 struct in_addr isaddr, itaddr, myaddr; 582 struct mbuf *mh, *mt; 583 u_int8_t *enaddr = NULL; 584 #if NCARP > 0 585 u_int8_t *ether_shost = NULL; 586 #endif 587 int op; 588 589 ea = mtod(m, struct ether_arp *); 590 op = ntohs(ea->arp_op); 591 if ((op != ARPOP_REQUEST) && (op != ARPOP_REPLY)) 592 goto out; 593 #if notyet 594 if ((op == ARPOP_REPLY) && (m->m_flags & (M_BCAST|M_MCAST))) { 595 log(LOG_ERR, 596 "arp: received reply to broadcast or multicast address\n"); 597 goto out; 598 } 599 #endif 600 601 bcopy((caddr_t)ea->arp_tpa, (caddr_t)&itaddr, sizeof(itaddr)); 602 bcopy((caddr_t)ea->arp_spa, (caddr_t)&isaddr, sizeof(isaddr)); 603 604 TAILQ_FOREACH(ia, &in_ifaddr, ia_list) { 605 if (itaddr.s_addr != ia->ia_addr.sin_addr.s_addr) 606 continue; 607 608 #if NCARP > 0 609 if (ia->ia_ifp->if_type == IFT_CARP && 610 ((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) == 611 (IFF_UP|IFF_RUNNING))) { 612 if (ia->ia_ifp == m->m_pkthdr.rcvif && 613 (op == ARPOP_REPLY || 614 carp_iamatch(ia, ea->arp_sha, 615 &enaddr, ðer_shost))) 616 break; 617 } else 618 #endif 619 if (ia->ia_ifp == m->m_pkthdr.rcvif) 620 break; 621 #if NBRIDGE > 0 622 /* 623 * If the interface we received the packet on 624 * is part of a bridge, check to see if we need 625 * to "bridge" the packet to ourselves at this 626 * layer. Note we still prefer a perfect match, 627 * but allow this weaker match if necessary. 628 */ 629 if (m->m_pkthdr.rcvif->if_bridge != NULL) { 630 if (m->m_pkthdr.rcvif->if_bridge == 631 ia->ia_ifp->if_bridge) 632 bridge_ia = ia; 633 #if NCARP > 0 634 else if (ia->ia_ifp->if_carpdev != NULL && 635 m->m_pkthdr.rcvif->if_bridge == 636 ia->ia_ifp->if_carpdev->if_bridge && 637 carp_iamatch(ia, ea->arp_sha, 638 &enaddr, ðer_shost)) 639 bridge_ia = ia; 640 #endif 641 } 642 #endif 643 } 644 645 #if NBRIDGE > 0 646 if (ia == NULL && bridge_ia != NULL) { 647 ia = bridge_ia; 648 ac = (struct arpcom *)bridge_ia->ia_ifp; 649 } 650 #endif 651 652 if (ia == NULL) { 653 TAILQ_FOREACH(ia, &in_ifaddr, ia_list) { 654 if (isaddr.s_addr != ia->ia_addr.sin_addr.s_addr) 655 continue; 656 if (ia->ia_ifp == m->m_pkthdr.rcvif) 657 break; 658 } 659 } 660 661 if (ia == NULL && m->m_pkthdr.rcvif->if_type != IFT_CARP) { 662 struct ifaddr *ifa; 663 664 TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrlist, ifa_list) { 665 if (ifa->ifa_addr->sa_family == AF_INET) 666 break; 667 } 668 if (ifa) 669 ia = (struct in_ifaddr *)ifa; 670 } 671 672 if (ia == NULL) 673 goto out; 674 675 if (!enaddr) 676 enaddr = ac->ac_enaddr; 677 myaddr = ia->ia_addr.sin_addr; 678 679 if (!bcmp((caddr_t)ea->arp_sha, enaddr, sizeof (ea->arp_sha))) 680 goto out; /* it's from me, ignore it. */ 681 if (ETHER_IS_MULTICAST (&ea->arp_sha[0])) 682 if (!bcmp((caddr_t)ea->arp_sha, (caddr_t)etherbroadcastaddr, 683 sizeof (ea->arp_sha))) { 684 log(LOG_ERR, "arp: ether address is broadcast for " 685 "IP address %s!\n", inet_ntoa(isaddr)); 686 goto out; 687 } 688 if (myaddr.s_addr && isaddr.s_addr == myaddr.s_addr) { 689 log(LOG_ERR, 690 "duplicate IP address %s sent from ethernet address %s\n", 691 inet_ntoa(isaddr), ether_sprintf(ea->arp_sha)); 692 itaddr = myaddr; 693 goto reply; 694 } 695 la = arplookup(isaddr.s_addr, itaddr.s_addr == myaddr.s_addr, 0, 696 m->m_pkthdr.rdomain); 697 if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) { 698 if (sdl->sdl_alen) { 699 if (bcmp(ea->arp_sha, LLADDR(sdl), sdl->sdl_alen)) { 700 if (rt->rt_flags & RTF_PERMANENT_ARP) { 701 log(LOG_WARNING, 702 "arp: attempt to overwrite permanent " 703 "entry for %s by %s on %s\n", 704 inet_ntoa(isaddr), 705 ether_sprintf(ea->arp_sha), 706 ac->ac_if.if_xname); 707 goto out; 708 } else if (rt->rt_ifp != &ac->ac_if) { 709 log(LOG_WARNING, 710 "arp: attempt to overwrite entry for %s " 711 "on %s by %s on %s\n", 712 inet_ntoa(isaddr), rt->rt_ifp->if_xname, 713 ether_sprintf(ea->arp_sha), 714 ac->ac_if.if_xname); 715 goto out; 716 } else { 717 log(LOG_INFO, 718 "arp info overwritten for %s by %s on %s\n", 719 inet_ntoa(isaddr), 720 ether_sprintf(ea->arp_sha), 721 ac->ac_if.if_xname); 722 rt->rt_expire = 1; /* no longer static */ 723 } 724 } 725 } else if (rt->rt_ifp != &ac->ac_if && !(ac->ac_if.if_bridge && 726 (rt->rt_ifp->if_bridge == ac->ac_if.if_bridge)) && 727 !(rt->rt_ifp->if_type == IFT_CARP && 728 rt->rt_ifp->if_carpdev == &ac->ac_if) && 729 !(ac->ac_if.if_type == IFT_CARP && 730 ac->ac_if.if_carpdev == rt->rt_ifp)) { 731 log(LOG_WARNING, 732 "arp: attempt to add entry for %s " 733 "on %s by %s on %s\n", 734 inet_ntoa(isaddr), rt->rt_ifp->if_xname, 735 ether_sprintf(ea->arp_sha), 736 ac->ac_if.if_xname); 737 goto out; 738 } 739 bcopy(ea->arp_sha, LLADDR(sdl), 740 sdl->sdl_alen = sizeof(ea->arp_sha)); 741 if (rt->rt_expire) 742 rt->rt_expire = time_second + arpt_keep; 743 rt->rt_flags &= ~RTF_REJECT; 744 la->la_asked = 0; 745 while ((mh = la->la_hold_head) != NULL) { 746 if ((la->la_hold_head = mh->m_nextpkt) == NULL) 747 la->la_hold_tail = NULL; 748 la->la_hold_count--; 749 la_hold_total--; 750 mt = la->la_hold_tail; 751 752 (*ac->ac_if.if_output)(&ac->ac_if, mh, rt_key(rt), rt); 753 754 if (la->la_hold_tail == mh) { 755 /* mbuf is back in queue. Discard. */ 756 la->la_hold_tail = mt; 757 if (la->la_hold_tail) 758 la->la_hold_tail->m_nextpkt = NULL; 759 else 760 la->la_hold_head = NULL; 761 la->la_hold_count--; 762 la_hold_total--; 763 m_freem(mh); 764 } 765 } 766 } 767 reply: 768 if (op != ARPOP_REQUEST) { 769 out: 770 m_freem(m); 771 return; 772 } 773 if (itaddr.s_addr == myaddr.s_addr) { 774 /* I am the target */ 775 bcopy(ea->arp_sha, ea->arp_tha, sizeof(ea->arp_sha)); 776 bcopy(enaddr, ea->arp_sha, sizeof(ea->arp_sha)); 777 } else { 778 la = arplookup(itaddr.s_addr, 0, SIN_PROXY, 779 m->m_pkthdr.rdomain); 780 if (la == 0) 781 goto out; 782 rt = la->la_rt; 783 if (rt->rt_ifp->if_type == IFT_CARP && 784 m->m_pkthdr.rcvif->if_type != IFT_CARP) 785 goto out; 786 bcopy(ea->arp_sha, ea->arp_tha, sizeof(ea->arp_sha)); 787 sdl = SDL(rt->rt_gateway); 788 bcopy(LLADDR(sdl), ea->arp_sha, sizeof(ea->arp_sha)); 789 } 790 791 bcopy(ea->arp_spa, ea->arp_tpa, sizeof(ea->arp_spa)); 792 bcopy(&itaddr, ea->arp_spa, sizeof(ea->arp_spa)); 793 ea->arp_op = htons(ARPOP_REPLY); 794 ea->arp_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 795 eh = (struct ether_header *)sa.sa_data; 796 bcopy(ea->arp_tha, eh->ether_dhost, sizeof(eh->ether_dhost)); 797 #if NCARP > 0 798 if (ether_shost) 799 enaddr = ether_shost; 800 #endif 801 bcopy(enaddr, eh->ether_shost, sizeof(eh->ether_shost)); 802 803 eh->ether_type = htons(ETHERTYPE_ARP); 804 sa.sa_family = pseudo_AF_HDRCMPLT; 805 sa.sa_len = sizeof(sa); 806 (*ac->ac_if.if_output)(&ac->ac_if, m, &sa, (struct rtentry *)0); 807 return; 808 } 809 810 /* 811 * Free an arp entry. 812 */ 813 void 814 arptfree(la) 815 struct llinfo_arp *la; 816 { 817 struct rtentry *rt = la->la_rt; 818 struct sockaddr_dl *sdl; 819 struct rt_addrinfo info; 820 u_int tid = 0; 821 822 if (rt == 0) 823 panic("arptfree"); 824 if (rt->rt_refcnt > 0 && (sdl = SDL(rt->rt_gateway)) && 825 sdl->sdl_family == AF_LINK) { 826 sdl->sdl_alen = 0; 827 la->la_asked = 0; 828 rt->rt_flags &= ~RTF_REJECT; 829 return; 830 } 831 bzero(&info, sizeof(info)); 832 info.rti_info[RTAX_DST] = rt_key(rt); 833 info.rti_info[RTAX_NETMASK] = rt_mask(rt); 834 835 if (rt->rt_ifp) 836 tid = rt->rt_ifp->if_rdomain; 837 838 rtrequest1(RTM_DELETE, &info, rt->rt_priority, NULL, tid); 839 } 840 841 /* 842 * Lookup or enter a new address in arptab. 843 */ 844 struct llinfo_arp * 845 arplookup(addr, create, proxy, tableid) 846 u_int32_t addr; 847 int create, proxy; 848 u_int tableid; 849 { 850 struct rtentry *rt; 851 static struct sockaddr_inarp sin; 852 853 sin.sin_len = sizeof(sin); 854 sin.sin_family = AF_INET; 855 sin.sin_addr.s_addr = addr; 856 sin.sin_other = proxy ? SIN_PROXY : 0; 857 rt = rtalloc1(sintosa(&sin), create, tableid); 858 if (rt == 0) 859 return (0); 860 rt->rt_refcnt--; 861 if ((rt->rt_flags & RTF_GATEWAY) || (rt->rt_flags & RTF_LLINFO) == 0 || 862 rt->rt_gateway->sa_family != AF_LINK) { 863 if (create) { 864 if (rt->rt_refcnt <= 0 && 865 (rt->rt_flags & RTF_CLONED) != 0) { 866 struct rt_addrinfo info; 867 868 bzero(&info, sizeof(info)); 869 info.rti_info[RTAX_DST] = rt_key(rt); 870 info.rti_info[RTAX_GATEWAY] = rt->rt_gateway; 871 info.rti_info[RTAX_NETMASK] = rt_mask(rt); 872 873 rtrequest1(RTM_DELETE, &info, rt->rt_priority, 874 NULL, tableid); 875 } 876 } 877 return (0); 878 } 879 return ((struct llinfo_arp *)rt->rt_llinfo); 880 } 881 882 int 883 arpioctl(cmd, data) 884 u_long cmd; 885 caddr_t data; 886 { 887 888 return (EOPNOTSUPP); 889 } 890 891 void 892 arp_ifinit(ac, ifa) 893 struct arpcom *ac; 894 struct ifaddr *ifa; 895 { 896 897 /* Warn the user if another station has this IP address. */ 898 arprequest(&ac->ac_if, 899 &(IA_SIN(ifa)->sin_addr.s_addr), 900 &(IA_SIN(ifa)->sin_addr.s_addr), 901 ac->ac_enaddr); 902 ifa->ifa_rtrequest = arp_rtrequest; 903 ifa->ifa_flags |= RTF_CLONING; 904 } 905 906 /* 907 * Called from Ethernet interrupt handlers 908 * when ether packet type ETHERTYPE_REVARP 909 * is received. Common length and type checks are done here, 910 * then the protocol-specific routine is called. 911 */ 912 void 913 revarpinput(m) 914 struct mbuf *m; 915 { 916 struct arphdr *ar; 917 918 if (m->m_len < sizeof(struct arphdr)) 919 goto out; 920 ar = mtod(m, struct arphdr *); 921 if (ntohs(ar->ar_hrd) != ARPHRD_ETHER) 922 goto out; 923 if (m->m_len < sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln)) 924 goto out; 925 switch (ntohs(ar->ar_pro)) { 926 927 case ETHERTYPE_IP: 928 case ETHERTYPE_IPTRAILERS: 929 in_revarpinput(m); 930 return; 931 932 default: 933 break; 934 } 935 out: 936 m_freem(m); 937 } 938 939 /* 940 * RARP for Internet protocols on Ethernet. 941 * Algorithm is that given in RFC 903. 942 * We are only using for bootstrap purposes to get an ip address for one of 943 * our interfaces. Thus we support no user-interface. 944 * 945 * Since the contents of the RARP reply are specific to the interface that 946 * sent the request, this code must ensure that they are properly associated. 947 * 948 * Note: also supports ARP via RARP packets, per the RFC. 949 */ 950 void 951 in_revarpinput(m) 952 struct mbuf *m; 953 { 954 struct ifnet *ifp; 955 struct ether_arp *ar; 956 int op; 957 958 ar = mtod(m, struct ether_arp *); 959 op = ntohs(ar->arp_op); 960 switch (op) { 961 case ARPOP_REQUEST: 962 case ARPOP_REPLY: /* per RFC */ 963 in_arpinput(m); 964 return; 965 case ARPOP_REVREPLY: 966 break; 967 case ARPOP_REVREQUEST: /* handled by rarpd(8) */ 968 default: 969 goto out; 970 } 971 if (!revarp_in_progress) 972 goto out; 973 ifp = m->m_pkthdr.rcvif; 974 if (ifp != myip_ifp) /* !same interface */ 975 goto out; 976 if (myip_initialized) 977 goto wake; 978 if (bcmp(ar->arp_tha, ((struct arpcom *)ifp)->ac_enaddr, 979 sizeof(ar->arp_tha))) 980 goto out; 981 bcopy((caddr_t)ar->arp_spa, (caddr_t)&srv_ip, sizeof(srv_ip)); 982 bcopy((caddr_t)ar->arp_tpa, (caddr_t)&myip, sizeof(myip)); 983 myip_initialized = 1; 984 wake: /* Do wakeup every time in case it was missed. */ 985 wakeup((caddr_t)&myip); 986 987 out: 988 m_freem(m); 989 } 990 991 /* 992 * Send a RARP request for the ip address of the specified interface. 993 * The request should be RFC 903-compliant. 994 */ 995 void 996 revarprequest(ifp) 997 struct ifnet *ifp; 998 { 999 struct sockaddr sa; 1000 struct mbuf *m; 1001 struct ether_header *eh; 1002 struct ether_arp *ea; 1003 struct arpcom *ac = (struct arpcom *)ifp; 1004 1005 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 1006 return; 1007 m->m_len = sizeof(*ea); 1008 m->m_pkthdr.len = sizeof(*ea); 1009 MH_ALIGN(m, sizeof(*ea)); 1010 ea = mtod(m, struct ether_arp *); 1011 eh = (struct ether_header *)sa.sa_data; 1012 bzero((caddr_t)ea, sizeof(*ea)); 1013 bcopy((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost, 1014 sizeof(eh->ether_dhost)); 1015 eh->ether_type = htons(ETHERTYPE_REVARP); 1016 ea->arp_hrd = htons(ARPHRD_ETHER); 1017 ea->arp_pro = htons(ETHERTYPE_IP); 1018 ea->arp_hln = sizeof(ea->arp_sha); /* hardware address length */ 1019 ea->arp_pln = sizeof(ea->arp_spa); /* protocol address length */ 1020 ea->arp_op = htons(ARPOP_REVREQUEST); 1021 bcopy((caddr_t)ac->ac_enaddr, (caddr_t)eh->ether_shost, 1022 sizeof(ea->arp_tha)); 1023 bcopy((caddr_t)ac->ac_enaddr, (caddr_t)ea->arp_sha, 1024 sizeof(ea->arp_sha)); 1025 bcopy((caddr_t)ac->ac_enaddr, (caddr_t)ea->arp_tha, 1026 sizeof(ea->arp_tha)); 1027 sa.sa_family = pseudo_AF_HDRCMPLT; 1028 sa.sa_len = sizeof(sa); 1029 ifp->if_output(ifp, m, &sa, (struct rtentry *)0); 1030 } 1031 1032 /* 1033 * RARP for the ip address of the specified interface, but also 1034 * save the ip address of the server that sent the answer. 1035 * Timeout if no response is received. 1036 */ 1037 int 1038 revarpwhoarewe(ifp, serv_in, clnt_in) 1039 struct ifnet *ifp; 1040 struct in_addr *serv_in; 1041 struct in_addr *clnt_in; 1042 { 1043 int result, count = 20; 1044 1045 if (myip_initialized) 1046 return EIO; 1047 1048 myip_ifp = ifp; 1049 revarp_in_progress = 1; 1050 while (count--) { 1051 revarprequest(ifp); 1052 result = tsleep((caddr_t)&myip, PSOCK, "revarp", hz/2); 1053 if (result != EWOULDBLOCK) 1054 break; 1055 } 1056 revarp_in_progress = 0; 1057 if (!myip_initialized) 1058 return ENETUNREACH; 1059 1060 bcopy((caddr_t)&srv_ip, serv_in, sizeof(*serv_in)); 1061 bcopy((caddr_t)&myip, clnt_in, sizeof(*clnt_in)); 1062 return 0; 1063 } 1064 1065 /* For compatibility: only saves interface address. */ 1066 int 1067 revarpwhoami(in, ifp) 1068 struct in_addr *in; 1069 struct ifnet *ifp; 1070 { 1071 struct in_addr server; 1072 return (revarpwhoarewe(ifp, &server, in)); 1073 } 1074 1075 1076 #ifdef DDB 1077 1078 #include <machine/db_machdep.h> 1079 #include <ddb/db_interface.h> 1080 #include <ddb/db_output.h> 1081 1082 void 1083 db_print_sa(sa) 1084 struct sockaddr *sa; 1085 { 1086 int len; 1087 u_char *p; 1088 1089 if (sa == 0) { 1090 db_printf("[NULL]"); 1091 return; 1092 } 1093 1094 p = (u_char *)sa; 1095 len = sa->sa_len; 1096 db_printf("["); 1097 while (len > 0) { 1098 db_printf("%d", *p); 1099 p++; 1100 len--; 1101 if (len) 1102 db_printf(","); 1103 } 1104 db_printf("]\n"); 1105 } 1106 1107 void 1108 db_print_ifa(ifa) 1109 struct ifaddr *ifa; 1110 { 1111 if (ifa == 0) 1112 return; 1113 db_printf(" ifa_addr="); 1114 db_print_sa(ifa->ifa_addr); 1115 db_printf(" ifa_dsta="); 1116 db_print_sa(ifa->ifa_dstaddr); 1117 db_printf(" ifa_mask="); 1118 db_print_sa(ifa->ifa_netmask); 1119 db_printf(" flags=0x%x, refcnt=%d, metric=%d\n", 1120 ifa->ifa_flags, ifa->ifa_refcnt, ifa->ifa_metric); 1121 } 1122 1123 void 1124 db_print_llinfo(li) 1125 caddr_t li; 1126 { 1127 struct llinfo_arp *la; 1128 1129 if (li == 0) 1130 return; 1131 la = (struct llinfo_arp *)li; 1132 db_printf(" la_rt=%p la_hold_head=%p, la_asked=0x%lx\n", 1133 la->la_rt, la->la_hold_head, la->la_asked); 1134 } 1135 1136 /* 1137 * Function to pass to rn_walktree(). 1138 * Return non-zero error to abort walk. 1139 */ 1140 int 1141 db_show_radix_node(rn, w) 1142 struct radix_node *rn; 1143 void *w; 1144 { 1145 struct rtentry *rt = (struct rtentry *)rn; 1146 1147 db_printf("rtentry=%p", rt); 1148 1149 db_printf(" flags=0x%x refcnt=%d use=%ld expire=%ld\n", 1150 rt->rt_flags, rt->rt_refcnt, rt->rt_use, rt->rt_expire); 1151 1152 db_printf(" key="); db_print_sa(rt_key(rt)); 1153 db_printf(" mask="); db_print_sa(rt_mask(rt)); 1154 db_printf(" gw="); db_print_sa(rt->rt_gateway); 1155 1156 db_printf(" ifp=%p ", rt->rt_ifp); 1157 if (rt->rt_ifp) 1158 db_printf("(%s)", rt->rt_ifp->if_xname); 1159 else 1160 db_printf("(NULL)"); 1161 1162 db_printf(" ifa=%p\n", rt->rt_ifa); 1163 db_print_ifa(rt->rt_ifa); 1164 1165 db_printf(" genmask="); db_print_sa(rt->rt_genmask); 1166 1167 db_printf(" gwroute=%p llinfo=%p\n", rt->rt_gwroute, rt->rt_llinfo); 1168 db_print_llinfo(rt->rt_llinfo); 1169 return (0); 1170 } 1171 1172 /* 1173 * Function to print all the route trees. 1174 * Use this from ddb: "call db_show_arptab" 1175 */ 1176 int 1177 db_show_arptab() 1178 { 1179 struct radix_node_head *rnh; 1180 rnh = rt_gettable(AF_INET, 0); 1181 db_printf("Route tree for AF_INET\n"); 1182 if (rnh == NULL) { 1183 db_printf(" (not initialized)\n"); 1184 return (0); 1185 } 1186 rn_walktree(rnh, db_show_radix_node, NULL); 1187 return (0); 1188 } 1189 #endif 1190 #endif /* INET */ 1191