1 /* 2 * Copyright (c) 1982, 1986, 1988, 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 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)if_ether.c 8.1 (Berkeley) 6/10/93 34 * $Id: if_ether.c,v 1.28 1996/02/20 17:54:17 fenner Exp $ 35 */ 36 37 /* 38 * Ethernet address resolution protocol. 39 * TODO: 40 * add "inuse/lock" bit (or ref. count) along with valid bit 41 */ 42 43 #include <sys/param.h> 44 #include <sys/kernel.h> 45 #include <sys/sysctl.h> 46 #include <sys/queue.h> 47 #include <sys/systm.h> 48 #include <sys/mbuf.h> 49 #include <sys/malloc.h> 50 #include <sys/syslog.h> 51 52 #include <net/if.h> 53 #include <net/if_dl.h> 54 #include <net/route.h> 55 #include <net/netisr.h> 56 57 #include <netinet/in.h> 58 #include <netinet/in_var.h> 59 #include <netinet/if_ether.h> 60 61 #define SIN(s) ((struct sockaddr_in *)s) 62 #define SDL(s) ((struct sockaddr_dl *)s) 63 64 SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, ""); 65 66 /* timer values */ 67 static int arpt_prune = (5*60*1); /* walk list every 5 minutes */ 68 static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */ 69 static int arpt_down = 20; /* once declared down, don't send for 20 sec */ 70 71 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, prune_intvl, CTLFLAG_RW, 72 &arpt_prune, 0, ""); 73 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW, 74 &arpt_keep, 0, ""); 75 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, host_down_time, CTLFLAG_RW, 76 &arpt_down, 0, ""); 77 78 #define rt_expire rt_rmx.rmx_expire 79 80 struct llinfo_arp { 81 LIST_ENTRY(llinfo_arp) la_le; 82 struct rtentry *la_rt; 83 struct mbuf *la_hold; /* last packet until resolved/timeout */ 84 long la_asked; /* last time we QUERIED for this addr */ 85 #define la_timer la_rt->rt_rmx.rmx_expire /* deletion time in seconds */ 86 }; 87 88 static LIST_HEAD(, llinfo_arp) llinfo_arp; 89 90 struct ifqueue arpintrq = {0, 0, 0, 50}; 91 static int arp_inuse, arp_allocated; 92 93 static int arp_maxtries = 5; 94 static int useloopback = 1; /* use loopback interface for local traffic */ 95 static int arp_proxyall = 0; 96 97 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW, 98 &arp_maxtries, 0, ""); 99 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW, 100 &useloopback, 0, ""); 101 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW, 102 &arp_proxyall, 0, ""); 103 104 static void arp_rtrequest __P((int, struct rtentry *, struct sockaddr *)); 105 static void arprequest __P((struct arpcom *, u_long *, u_long *, u_char *)); 106 static void arpintr __P((void)); 107 static void arptfree __P((struct llinfo_arp *)); 108 static void arptimer __P((void *)); 109 static struct llinfo_arp 110 *arplookup __P((u_long, int, int)); 111 static void in_arpinput __P((struct mbuf *)); 112 113 /* 114 * Timeout routine. Age arp_tab entries periodically. 115 */ 116 /* ARGSUSED */ 117 static void 118 arptimer(ignored_arg) 119 void *ignored_arg; 120 { 121 int s = splnet(); 122 register struct llinfo_arp *la = llinfo_arp.lh_first; 123 struct llinfo_arp *ola; 124 125 timeout(arptimer, (caddr_t)0, arpt_prune * hz); 126 while ((ola = la) != 0) { 127 register struct rtentry *rt = la->la_rt; 128 la = la->la_le.le_next; 129 if (rt->rt_expire && rt->rt_expire <= time.tv_sec) 130 arptfree(ola); /* timer has expired, clear */ 131 } 132 splx(s); 133 } 134 135 /* 136 * Parallel to llc_rtrequest. 137 */ 138 static void 139 arp_rtrequest(req, rt, sa) 140 int req; 141 register struct rtentry *rt; 142 struct sockaddr *sa; 143 { 144 register struct sockaddr *gate = rt->rt_gateway; 145 register struct llinfo_arp *la = (struct llinfo_arp *)rt->rt_llinfo; 146 static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK}; 147 static int arpinit_done; 148 149 if (!arpinit_done) { 150 arpinit_done = 1; 151 LIST_INIT(&llinfo_arp); 152 timeout(arptimer, (caddr_t)0, hz); 153 } 154 if (rt->rt_flags & RTF_GATEWAY) 155 return; 156 switch (req) { 157 158 case RTM_ADD: 159 /* 160 * XXX: If this is a manually added route to interface 161 * such as older version of routed or gated might provide, 162 * restore cloning bit. 163 */ 164 if ((rt->rt_flags & RTF_HOST) == 0 && 165 SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff) 166 rt->rt_flags |= RTF_CLONING; 167 if (rt->rt_flags & RTF_CLONING) { 168 /* 169 * Case 1: This route should come from a route to iface. 170 */ 171 rt_setgate(rt, rt_key(rt), 172 (struct sockaddr *)&null_sdl); 173 gate = rt->rt_gateway; 174 SDL(gate)->sdl_type = rt->rt_ifp->if_type; 175 SDL(gate)->sdl_index = rt->rt_ifp->if_index; 176 rt->rt_expire = time.tv_sec; 177 break; 178 } 179 /* Announce a new entry if requested. */ 180 if (rt->rt_flags & RTF_ANNOUNCE) 181 arprequest((struct arpcom *)rt->rt_ifp, 182 &SIN(rt_key(rt))->sin_addr.s_addr, 183 &SIN(rt_key(rt))->sin_addr.s_addr, 184 (u_char *)LLADDR(SDL(gate))); 185 /*FALLTHROUGH*/ 186 case RTM_RESOLVE: 187 if (gate->sa_family != AF_LINK || 188 gate->sa_len < sizeof(null_sdl)) { 189 log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n"); 190 break; 191 } 192 SDL(gate)->sdl_type = rt->rt_ifp->if_type; 193 SDL(gate)->sdl_index = rt->rt_ifp->if_index; 194 if (la != 0) 195 break; /* This happens on a route change */ 196 /* 197 * Case 2: This route may come from cloning, or a manual route 198 * add with a LL address. 199 */ 200 R_Malloc(la, struct llinfo_arp *, sizeof(*la)); 201 rt->rt_llinfo = (caddr_t)la; 202 if (la == 0) { 203 log(LOG_DEBUG, "arp_rtrequest: malloc failed\n"); 204 break; 205 } 206 arp_inuse++, arp_allocated++; 207 Bzero(la, sizeof(*la)); 208 la->la_rt = rt; 209 rt->rt_flags |= RTF_LLINFO; 210 LIST_INSERT_HEAD(&llinfo_arp, la, la_le); 211 212 /* 213 * This keeps the multicast addresses from showing up 214 * in `arp -a' listings as unresolved. It's not actually 215 * functional. Then the same for broadcast. 216 */ 217 if (IN_MULTICAST(ntohl(SIN(rt_key(rt))->sin_addr.s_addr))) { 218 ETHER_MAP_IP_MULTICAST(&SIN(rt_key(rt))->sin_addr, 219 LLADDR(SDL(gate))); 220 SDL(gate)->sdl_alen = 6; 221 } 222 if (in_broadcast(SIN(rt_key(rt))->sin_addr, rt->rt_ifp)) { 223 memcpy(LLADDR(SDL(gate)), etherbroadcastaddr, 6); 224 SDL(gate)->sdl_alen = 6; 225 } 226 227 if (SIN(rt_key(rt))->sin_addr.s_addr == 228 (IA_SIN(rt->rt_ifa))->sin_addr.s_addr) { 229 /* 230 * This test used to be 231 * if (loif.if_flags & IFF_UP) 232 * It allowed local traffic to be forced 233 * through the hardware by configuring the loopback down. 234 * However, it causes problems during network configuration 235 * for boards that can't receive packets they send. 236 * It is now necessary to clear "useloopback" and remove 237 * the route to force traffic out to the hardware. 238 */ 239 rt->rt_expire = 0; 240 Bcopy(((struct arpcom *)rt->rt_ifp)->ac_enaddr, 241 LLADDR(SDL(gate)), SDL(gate)->sdl_alen = 6); 242 if (useloopback) 243 rt->rt_ifp = loif; 244 245 } 246 break; 247 248 case RTM_DELETE: 249 if (la == 0) 250 break; 251 arp_inuse--; 252 LIST_REMOVE(la, la_le); 253 rt->rt_llinfo = 0; 254 rt->rt_flags &= ~RTF_LLINFO; 255 if (la->la_hold) 256 m_freem(la->la_hold); 257 Free((caddr_t)la); 258 } 259 } 260 261 /* 262 * Broadcast an ARP request. Caller specifies: 263 * - arp header source ip address 264 * - arp header target ip address 265 * - arp header source ethernet address 266 */ 267 static void 268 arprequest(ac, sip, tip, enaddr) 269 register struct arpcom *ac; 270 register u_long *sip, *tip; 271 register u_char *enaddr; 272 { 273 register struct mbuf *m; 274 register struct ether_header *eh; 275 register struct ether_arp *ea; 276 struct sockaddr sa; 277 278 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 279 return; 280 m->m_len = sizeof(*ea); 281 m->m_pkthdr.len = sizeof(*ea); 282 MH_ALIGN(m, sizeof(*ea)); 283 ea = mtod(m, struct ether_arp *); 284 eh = (struct ether_header *)sa.sa_data; 285 bzero((caddr_t)ea, sizeof (*ea)); 286 (void)memcpy(eh->ether_dhost, etherbroadcastaddr, sizeof(eh->ether_dhost)); 287 eh->ether_type = ETHERTYPE_ARP; /* if_output will swap */ 288 ea->arp_hrd = htons(ARPHRD_ETHER); 289 ea->arp_pro = htons(ETHERTYPE_IP); 290 ea->arp_hln = sizeof(ea->arp_sha); /* hardware address length */ 291 ea->arp_pln = sizeof(ea->arp_spa); /* protocol address length */ 292 ea->arp_op = htons(ARPOP_REQUEST); 293 (void)memcpy(ea->arp_sha, enaddr, sizeof(ea->arp_sha)); 294 (void)memcpy(ea->arp_spa, sip, sizeof(ea->arp_spa)); 295 (void)memcpy(ea->arp_tpa, tip, sizeof(ea->arp_tpa)); 296 sa.sa_family = AF_UNSPEC; 297 sa.sa_len = sizeof(sa); 298 (*ac->ac_if.if_output)(&ac->ac_if, m, &sa, (struct rtentry *)0); 299 } 300 301 /* 302 * Resolve an IP address into an ethernet address. If success, 303 * desten is filled in. If there is no entry in arptab, 304 * set one up and broadcast a request for the IP address. 305 * Hold onto this mbuf and resend it once the address 306 * is finally resolved. A return value of 1 indicates 307 * that desten has been filled in and the packet should be sent 308 * normally; a 0 return indicates that the packet has been 309 * taken over here, either now or for later transmission. 310 */ 311 int 312 arpresolve(ac, rt, m, dst, desten, rt0) 313 register struct arpcom *ac; 314 register struct rtentry *rt; 315 struct mbuf *m; 316 register struct sockaddr *dst; 317 register u_char *desten; 318 struct rtentry *rt0; 319 { 320 register struct llinfo_arp *la; 321 struct sockaddr_dl *sdl; 322 323 if (m->m_flags & M_BCAST) { /* broadcast */ 324 (void)memcpy(desten, etherbroadcastaddr, sizeof(etherbroadcastaddr)); 325 return (1); 326 } 327 if (m->m_flags & M_MCAST) { /* multicast */ 328 ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten); 329 return(1); 330 } 331 if (rt) 332 la = (struct llinfo_arp *)rt->rt_llinfo; 333 else { 334 la = arplookup(SIN(dst)->sin_addr.s_addr, 1, 0); 335 if (la) 336 rt = la->la_rt; 337 } 338 if (la == 0 || rt == 0) { 339 log(LOG_DEBUG, "arpresolve: can't allocate llinfo for %s\n", 340 inet_ntoa(SIN(dst)->sin_addr)); 341 m_freem(m); 342 return (0); 343 } 344 sdl = SDL(rt->rt_gateway); 345 /* 346 * Check the address family and length is valid, the address 347 * is resolved; otherwise, try to resolve. 348 */ 349 if ((rt->rt_expire == 0 || rt->rt_expire > time.tv_sec) && 350 sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) { 351 (void)memcpy(desten, LLADDR(sdl), sdl->sdl_alen); 352 return 1; 353 } 354 /* 355 * There is an arptab entry, but no ethernet address 356 * response yet. Replace the held mbuf with this 357 * latest one. 358 */ 359 if (la->la_hold) 360 m_freem(la->la_hold); 361 la->la_hold = m; 362 if (rt->rt_expire) { 363 rt->rt_flags &= ~RTF_REJECT; 364 if (la->la_asked == 0 || rt->rt_expire != time.tv_sec) { 365 rt->rt_expire = time.tv_sec; 366 if (la->la_asked++ < arp_maxtries) 367 arprequest(ac, 368 &(SIN(rt0->rt_ifa->ifa_addr)->sin_addr.s_addr), 369 &(SIN(dst)->sin_addr.s_addr), 370 ac->ac_enaddr); 371 else { 372 rt->rt_flags |= RTF_REJECT; 373 rt->rt_expire += arpt_down; 374 la->la_asked = 0; 375 } 376 377 } 378 } 379 return (0); 380 } 381 382 /* 383 * Common length and type checks are done here, 384 * then the protocol-specific routine is called. 385 */ 386 static void 387 arpintr(void) 388 { 389 register struct mbuf *m; 390 register struct arphdr *ar; 391 int s; 392 393 while (arpintrq.ifq_head) { 394 s = splimp(); 395 IF_DEQUEUE(&arpintrq, m); 396 splx(s); 397 if (m == 0 || (m->m_flags & M_PKTHDR) == 0) 398 panic("arpintr"); 399 if (m->m_len >= sizeof(struct arphdr) && 400 (ar = mtod(m, struct arphdr *)) && 401 ntohs(ar->ar_hrd) == ARPHRD_ETHER && 402 m->m_len >= 403 sizeof(struct arphdr) + 2 * ar->ar_hln + 2 * ar->ar_pln) 404 405 switch (ntohs(ar->ar_pro)) { 406 407 case ETHERTYPE_IP: 408 in_arpinput(m); 409 continue; 410 } 411 m_freem(m); 412 } 413 } 414 415 NETISR_SET(NETISR_ARP, arpintr); 416 417 /* 418 * ARP for Internet protocols on 10 Mb/s Ethernet. 419 * Algorithm is that given in RFC 826. 420 * In addition, a sanity check is performed on the sender 421 * protocol address, to catch impersonators. 422 * We no longer handle negotiations for use of trailer protocol: 423 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent 424 * along with IP replies if we wanted trailers sent to us, 425 * and also sent them in response to IP replies. 426 * This allowed either end to announce the desire to receive 427 * trailer packets. 428 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, 429 * but formerly didn't normally send requests. 430 */ 431 static void 432 in_arpinput(m) 433 struct mbuf *m; 434 { 435 register struct ether_arp *ea; 436 register struct arpcom *ac = (struct arpcom *)m->m_pkthdr.rcvif; 437 struct ether_header *eh; 438 register struct llinfo_arp *la = 0; 439 register struct rtentry *rt; 440 struct in_ifaddr *ia, *maybe_ia = 0; 441 struct sockaddr_dl *sdl; 442 struct sockaddr sa; 443 struct in_addr isaddr, itaddr, myaddr; 444 int op; 445 446 ea = mtod(m, struct ether_arp *); 447 op = ntohs(ea->arp_op); 448 (void)memcpy(&isaddr, ea->arp_spa, sizeof (isaddr)); 449 (void)memcpy(&itaddr, ea->arp_tpa, sizeof (itaddr)); 450 for (ia = in_ifaddr; ia; ia = ia->ia_next) 451 if (ia->ia_ifp == &ac->ac_if) { 452 maybe_ia = ia; 453 if ((itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) || 454 (isaddr.s_addr == ia->ia_addr.sin_addr.s_addr)) 455 break; 456 } 457 if (maybe_ia == 0) { 458 m_freem(m); 459 return; 460 } 461 myaddr = ia ? ia->ia_addr.sin_addr : maybe_ia->ia_addr.sin_addr; 462 if (!bcmp((caddr_t)ea->arp_sha, (caddr_t)ac->ac_enaddr, 463 sizeof (ea->arp_sha))) { 464 m_freem(m); /* it's from me, ignore it. */ 465 return; 466 } 467 if (!bcmp((caddr_t)ea->arp_sha, (caddr_t)etherbroadcastaddr, 468 sizeof (ea->arp_sha))) { 469 log(LOG_ERR, 470 "arp: ether address is broadcast for IP address %s!\n", 471 inet_ntoa(isaddr)); 472 m_freem(m); 473 return; 474 } 475 if (isaddr.s_addr == myaddr.s_addr) { 476 log(LOG_ERR, 477 "duplicate IP address %s! sent from ethernet address: %6D\n", 478 inet_ntoa(isaddr), ea->arp_sha, ":"); 479 itaddr = myaddr; 480 goto reply; 481 } 482 la = arplookup(isaddr.s_addr, itaddr.s_addr == myaddr.s_addr, 0); 483 if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) { 484 if (sdl->sdl_alen && 485 bcmp((caddr_t)ea->arp_sha, LLADDR(sdl), sdl->sdl_alen)) 486 log(LOG_INFO, "arp info overwritten for %s by %6D\n", 487 inet_ntoa(isaddr), ea->arp_sha, ":"); 488 (void)memcpy(LLADDR(sdl), ea->arp_sha, sizeof(ea->arp_sha)); 489 sdl->sdl_alen = sizeof(ea->arp_sha); 490 if (rt->rt_expire) 491 rt->rt_expire = time.tv_sec + arpt_keep; 492 rt->rt_flags &= ~RTF_REJECT; 493 la->la_asked = 0; 494 if (la->la_hold) { 495 (*ac->ac_if.if_output)(&ac->ac_if, la->la_hold, 496 rt_key(rt), rt); 497 la->la_hold = 0; 498 } 499 } 500 reply: 501 if (op != ARPOP_REQUEST) { 502 m_freem(m); 503 return; 504 } 505 if (itaddr.s_addr == myaddr.s_addr) { 506 /* I am the target */ 507 (void)memcpy(ea->arp_tha, ea->arp_sha, sizeof(ea->arp_sha)); 508 (void)memcpy(ea->arp_sha, ac->ac_enaddr, sizeof(ea->arp_sha)); 509 } else { 510 la = arplookup(itaddr.s_addr, 0, SIN_PROXY); 511 if (la == NULL) { 512 struct sockaddr_in sin; 513 514 if (!arp_proxyall) { 515 m_freem(m); 516 return; 517 } 518 519 bzero(&sin, sizeof sin); 520 sin.sin_family = AF_INET; 521 sin.sin_len = sizeof sin; 522 sin.sin_addr = itaddr; 523 524 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL); 525 if (!rt) { 526 m_freem(m); 527 return; 528 } 529 /* 530 * Don't send proxies for nodes on the same interface 531 * as this one came out of, or we'll get into a fight 532 * over who claims what Ether address. 533 */ 534 if (rt->rt_ifp == &ac->ac_if) { 535 rtfree(rt); 536 m_freem(m); 537 return; 538 } 539 (void)memcpy(ea->arp_tha, ea->arp_sha, sizeof(ea->arp_sha)); 540 (void)memcpy(ea->arp_sha, ac->ac_enaddr, sizeof(ea->arp_sha)); 541 rtfree(rt); 542 #ifdef DEBUG_PROXY 543 printf("arp: proxying for %s\n", 544 inet_ntoa(itaddr)); 545 #endif 546 } else { 547 rt = la->la_rt; 548 (void)memcpy(ea->arp_tha, ea->arp_sha, sizeof(ea->arp_sha)); 549 sdl = SDL(rt->rt_gateway); 550 (void)memcpy(ea->arp_sha, LLADDR(sdl), sizeof(ea->arp_sha)); 551 } 552 } 553 554 (void)memcpy(ea->arp_tpa, ea->arp_spa, sizeof(ea->arp_spa)); 555 (void)memcpy(ea->arp_spa, &itaddr, sizeof(ea->arp_spa)); 556 ea->arp_op = htons(ARPOP_REPLY); 557 ea->arp_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 558 eh = (struct ether_header *)sa.sa_data; 559 (void)memcpy(eh->ether_dhost, ea->arp_tha, sizeof(eh->ether_dhost)); 560 eh->ether_type = ETHERTYPE_ARP; 561 sa.sa_family = AF_UNSPEC; 562 sa.sa_len = sizeof(sa); 563 (*ac->ac_if.if_output)(&ac->ac_if, m, &sa, (struct rtentry *)0); 564 return; 565 } 566 567 /* 568 * Free an arp entry. 569 */ 570 static void 571 arptfree(la) 572 register struct llinfo_arp *la; 573 { 574 register struct rtentry *rt = la->la_rt; 575 register struct sockaddr_dl *sdl; 576 if (rt == 0) 577 panic("arptfree"); 578 if (rt->rt_refcnt > 0 && (sdl = SDL(rt->rt_gateway)) && 579 sdl->sdl_family == AF_LINK) { 580 sdl->sdl_alen = 0; 581 la->la_asked = 0; 582 rt->rt_flags &= ~RTF_REJECT; 583 return; 584 } 585 rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0, rt_mask(rt), 586 0, (struct rtentry **)0); 587 } 588 /* 589 * Lookup or enter a new address in arptab. 590 */ 591 static struct llinfo_arp * 592 arplookup(addr, create, proxy) 593 u_long addr; 594 int create, proxy; 595 { 596 register struct rtentry *rt; 597 static struct sockaddr_inarp sin = {sizeof(sin), AF_INET }; 598 const char *why = 0; 599 600 sin.sin_addr.s_addr = addr; 601 sin.sin_other = proxy ? SIN_PROXY : 0; 602 rt = rtalloc1((struct sockaddr *)&sin, create, 0UL); 603 if (rt == 0) 604 return (0); 605 rt->rt_refcnt--; 606 607 if (rt->rt_flags & RTF_GATEWAY) 608 why = "host is not on local network"; 609 else if ((rt->rt_flags & RTF_LLINFO) == 0) 610 why = "could not allocate llinfo"; 611 else if (rt->rt_gateway->sa_family != AF_LINK) 612 why = "gateway route is not ours"; 613 614 if (why && create) { 615 log(LOG_DEBUG, "arplookup %s failed: %s\n", 616 inet_ntoa(sin.sin_addr), why); 617 return 0; 618 } else if (why) { 619 return 0; 620 } 621 return ((struct llinfo_arp *)rt->rt_llinfo); 622 } 623 624 void 625 arp_ifinit(ac, ifa) 626 struct arpcom *ac; 627 struct ifaddr *ifa; 628 { 629 arprequest(ac, &(IA_SIN(ifa)->sin_addr.s_addr), 630 &(IA_SIN(ifa)->sin_addr.s_addr), ac->ac_enaddr); 631 ifa->ifa_rtrequest = arp_rtrequest; 632 ifa->ifa_flags |= RTF_CLONING; 633 } 634