if_ether.c revision 30813
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 1.40 1997/05/14 16:39:52 tegge 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/systm.h> 47#include <sys/mbuf.h> 48#include <sys/malloc.h> 49#include <sys/socket.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 64SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, ""); 65 66/* timer values */ 67static int arpt_prune = (5*60*1); /* walk list every 5 minutes */ 68static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */ 69static int arpt_down = 20; /* once declared down, don't send for 20 sec */ 70 71SYSCTL_INT(_net_link_ether_inet, OID_AUTO, prune_intvl, CTLFLAG_RW, 72 &arpt_prune, 0, ""); 73SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW, 74 &arpt_keep, 0, ""); 75SYSCTL_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 80struct 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 88static LIST_HEAD(, llinfo_arp) llinfo_arp; 89 90struct ifqueue arpintrq = {0, 0, 0, 50}; 91static int arp_inuse, arp_allocated; 92 93static int arp_maxtries = 5; 94static int useloopback = 1; /* use loopback interface for local traffic */ 95static int arp_proxyall = 0; 96 97SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW, 98 &arp_maxtries, 0, ""); 99SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW, 100 &useloopback, 0, ""); 101SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW, 102 &arp_proxyall, 0, ""); 103 104static void arp_rtrequest __P((int, struct rtentry *, struct sockaddr *)); 105static void arprequest __P((struct arpcom *, u_long *, u_long *, u_char *)); 106static void arpintr __P((void)); 107static void arptfree __P((struct llinfo_arp *)); 108static void arptimer __P((void *)); 109static struct llinfo_arp 110 *arplookup __P((u_long, int, int)); 111static void in_arpinput __P((struct mbuf *)); 112 113/* 114 * Timeout routine. Age arp_tab entries periodically. 115 */ 116/* ARGSUSED */ 117static void 118arptimer(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 */ 138static void 139arp_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 rt->rt_expire = 0; 222 } 223 if (in_broadcast(SIN(rt_key(rt))->sin_addr, rt->rt_ifp)) { 224 memcpy(LLADDR(SDL(gate)), etherbroadcastaddr, 6); 225 SDL(gate)->sdl_alen = 6; 226 rt->rt_expire = 0; 227 } 228 229 if (SIN(rt_key(rt))->sin_addr.s_addr == 230 (IA_SIN(rt->rt_ifa))->sin_addr.s_addr) { 231 /* 232 * This test used to be 233 * if (loif.if_flags & IFF_UP) 234 * It allowed local traffic to be forced 235 * through the hardware by configuring the loopback down. 236 * However, it causes problems during network configuration 237 * for boards that can't receive packets they send. 238 * It is now necessary to clear "useloopback" and remove 239 * the route to force traffic out to the hardware. 240 */ 241 rt->rt_expire = 0; 242 Bcopy(((struct arpcom *)rt->rt_ifp)->ac_enaddr, 243 LLADDR(SDL(gate)), SDL(gate)->sdl_alen = 6); 244 if (useloopback) 245 rt->rt_ifp = loif; 246 247 } 248 break; 249 250 case RTM_DELETE: 251 if (la == 0) 252 break; 253 arp_inuse--; 254 LIST_REMOVE(la, la_le); 255 rt->rt_llinfo = 0; 256 rt->rt_flags &= ~RTF_LLINFO; 257 if (la->la_hold) 258 m_freem(la->la_hold); 259 Free((caddr_t)la); 260 } 261} 262 263/* 264 * Broadcast an ARP request. Caller specifies: 265 * - arp header source ip address 266 * - arp header target ip address 267 * - arp header source ethernet address 268 */ 269static void 270arprequest(ac, sip, tip, enaddr) 271 register struct arpcom *ac; 272 register u_long *sip, *tip; 273 register u_char *enaddr; 274{ 275 register struct mbuf *m; 276 register struct ether_header *eh; 277 register struct ether_arp *ea; 278 struct sockaddr sa; 279 280 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 281 return; 282 m->m_len = sizeof(*ea); 283 m->m_pkthdr.len = sizeof(*ea); 284 MH_ALIGN(m, sizeof(*ea)); 285 ea = mtod(m, struct ether_arp *); 286 eh = (struct ether_header *)sa.sa_data; 287 bzero((caddr_t)ea, sizeof (*ea)); 288 (void)memcpy(eh->ether_dhost, etherbroadcastaddr, sizeof(eh->ether_dhost)); 289 eh->ether_type = htons(ETHERTYPE_ARP); /* if_output will not swap */ 290 ea->arp_hrd = htons(ARPHRD_ETHER); 291 ea->arp_pro = htons(ETHERTYPE_IP); 292 ea->arp_hln = sizeof(ea->arp_sha); /* hardware address length */ 293 ea->arp_pln = sizeof(ea->arp_spa); /* protocol address length */ 294 ea->arp_op = htons(ARPOP_REQUEST); 295 (void)memcpy(ea->arp_sha, enaddr, sizeof(ea->arp_sha)); 296 (void)memcpy(ea->arp_spa, sip, sizeof(ea->arp_spa)); 297 (void)memcpy(ea->arp_tpa, tip, sizeof(ea->arp_tpa)); 298 sa.sa_family = AF_UNSPEC; 299 sa.sa_len = sizeof(sa); 300 (*ac->ac_if.if_output)(&ac->ac_if, m, &sa, (struct rtentry *)0); 301} 302 303/* 304 * Resolve an IP address into an ethernet address. If success, 305 * desten is filled in. If there is no entry in arptab, 306 * set one up and broadcast a request for the IP address. 307 * Hold onto this mbuf and resend it once the address 308 * is finally resolved. A return value of 1 indicates 309 * that desten has been filled in and the packet should be sent 310 * normally; a 0 return indicates that the packet has been 311 * taken over here, either now or for later transmission. 312 */ 313int 314arpresolve(ac, rt, m, dst, desten, rt0) 315 register struct arpcom *ac; 316 register struct rtentry *rt; 317 struct mbuf *m; 318 register struct sockaddr *dst; 319 register u_char *desten; 320 struct rtentry *rt0; 321{ 322 register struct llinfo_arp *la; 323 struct sockaddr_dl *sdl; 324 325 if (m->m_flags & M_BCAST) { /* broadcast */ 326 (void)memcpy(desten, etherbroadcastaddr, sizeof(etherbroadcastaddr)); 327 return (1); 328 } 329 if (m->m_flags & M_MCAST) { /* multicast */ 330 ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten); 331 return(1); 332 } 333 if (rt) 334 la = (struct llinfo_arp *)rt->rt_llinfo; 335 else { 336 la = arplookup(SIN(dst)->sin_addr.s_addr, 1, 0); 337 if (la) 338 rt = la->la_rt; 339 } 340 if (la == 0 || rt == 0) { 341 log(LOG_DEBUG, "arpresolve: can't allocate llinfo for %s\n", 342 inet_ntoa(SIN(dst)->sin_addr)); 343 m_freem(m); 344 return (0); 345 } 346 sdl = SDL(rt->rt_gateway); 347 /* 348 * Check the address family and length is valid, the address 349 * is resolved; otherwise, try to resolve. 350 */ 351 if ((rt->rt_expire == 0 || rt->rt_expire > time.tv_sec) && 352 sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) { 353 bcopy(LLADDR(sdl), desten, sdl->sdl_alen); 354 return 1; 355 } 356 /* 357 * There is an arptab entry, but no ethernet address 358 * response yet. Replace the held mbuf with this 359 * latest one. 360 */ 361 if (la->la_hold) 362 m_freem(la->la_hold); 363 la->la_hold = m; 364 if (rt->rt_expire) { 365 rt->rt_flags &= ~RTF_REJECT; 366 if (la->la_asked == 0 || rt->rt_expire != time.tv_sec) { 367 rt->rt_expire = time.tv_sec; 368 if (la->la_asked++ < arp_maxtries) 369 arprequest(ac, 370 &(SIN(rt->rt_ifa->ifa_addr)->sin_addr.s_addr), 371 &(SIN(dst)->sin_addr.s_addr), 372 ac->ac_enaddr); 373 else { 374 rt->rt_flags |= RTF_REJECT; 375 rt->rt_expire += arpt_down; 376 la->la_asked = 0; 377 } 378 379 } 380 } 381 return (0); 382} 383 384/* 385 * Common length and type checks are done here, 386 * then the protocol-specific routine is called. 387 */ 388static void 389arpintr(void) 390{ 391 register struct mbuf *m; 392 register struct arphdr *ar; 393 int s; 394 395 while (arpintrq.ifq_head) { 396 s = splimp(); 397 IF_DEQUEUE(&arpintrq, m); 398 splx(s); 399 if (m == 0 || (m->m_flags & M_PKTHDR) == 0) 400 panic("arpintr"); 401 if (m->m_len >= sizeof(struct arphdr) && 402 (ar = mtod(m, struct arphdr *)) && 403 ntohs(ar->ar_hrd) == ARPHRD_ETHER && 404 m->m_len >= 405 sizeof(struct arphdr) + 2 * ar->ar_hln + 2 * ar->ar_pln) 406 407 switch (ntohs(ar->ar_pro)) { 408 409 case ETHERTYPE_IP: 410 in_arpinput(m); 411 continue; 412 } 413 m_freem(m); 414 } 415} 416 417NETISR_SET(NETISR_ARP, arpintr); 418 419/* 420 * ARP for Internet protocols on 10 Mb/s Ethernet. 421 * Algorithm is that given in RFC 826. 422 * In addition, a sanity check is performed on the sender 423 * protocol address, to catch impersonators. 424 * We no longer handle negotiations for use of trailer protocol: 425 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent 426 * along with IP replies if we wanted trailers sent to us, 427 * and also sent them in response to IP replies. 428 * This allowed either end to announce the desire to receive 429 * trailer packets. 430 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, 431 * but formerly didn't normally send requests. 432 */ 433static void 434in_arpinput(m) 435 struct mbuf *m; 436{ 437 register struct ether_arp *ea; 438 register struct arpcom *ac = (struct arpcom *)m->m_pkthdr.rcvif; 439 struct ether_header *eh; 440 register struct llinfo_arp *la = 0; 441 register struct rtentry *rt; 442 struct in_ifaddr *ia, *maybe_ia = 0; 443 struct sockaddr_dl *sdl; 444 struct sockaddr sa; 445 struct in_addr isaddr, itaddr, myaddr; 446 int op; 447 448 ea = mtod(m, struct ether_arp *); 449 op = ntohs(ea->arp_op); 450 (void)memcpy(&isaddr, ea->arp_spa, sizeof (isaddr)); 451 (void)memcpy(&itaddr, ea->arp_tpa, sizeof (itaddr)); 452 for (ia = in_ifaddrhead.tqh_first; ia; ia = ia->ia_link.tqe_next) 453 if (ia->ia_ifp == &ac->ac_if) { 454 maybe_ia = ia; 455 if ((itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) || 456 (isaddr.s_addr == ia->ia_addr.sin_addr.s_addr)) 457 break; 458 } 459 if (maybe_ia == 0) { 460 m_freem(m); 461 return; 462 } 463 myaddr = ia ? ia->ia_addr.sin_addr : maybe_ia->ia_addr.sin_addr; 464 if (!bcmp((caddr_t)ea->arp_sha, (caddr_t)ac->ac_enaddr, 465 sizeof (ea->arp_sha))) { 466 m_freem(m); /* it's from me, ignore it. */ 467 return; 468 } 469 if (!bcmp((caddr_t)ea->arp_sha, (caddr_t)etherbroadcastaddr, 470 sizeof (ea->arp_sha))) { 471 log(LOG_ERR, 472 "arp: ether address is broadcast for IP address %s!\n", 473 inet_ntoa(isaddr)); 474 m_freem(m); 475 return; 476 } 477 if (isaddr.s_addr == myaddr.s_addr) { 478 log(LOG_ERR, 479 "arp: %6D is using my IP address %s!\n", 480 ea->arp_sha, ":", inet_ntoa(isaddr)); 481 itaddr = myaddr; 482 goto reply; 483 } 484 la = arplookup(isaddr.s_addr, itaddr.s_addr == myaddr.s_addr, 0); 485 if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) { 486 if (sdl->sdl_alen && 487 bcmp((caddr_t)ea->arp_sha, LLADDR(sdl), sdl->sdl_alen)) 488 log(LOG_INFO, "arp: %s moved from %6D to %6D\n", 489 inet_ntoa(isaddr), (u_char *)LLADDR(sdl), ":", 490 ea->arp_sha, ":"); 491 (void)memcpy(LLADDR(sdl), ea->arp_sha, sizeof(ea->arp_sha)); 492 sdl->sdl_alen = sizeof(ea->arp_sha); 493 if (rt->rt_expire) 494 rt->rt_expire = time.tv_sec + arpt_keep; 495 rt->rt_flags &= ~RTF_REJECT; 496 la->la_asked = 0; 497 if (la->la_hold) { 498 (*ac->ac_if.if_output)(&ac->ac_if, la->la_hold, 499 rt_key(rt), rt); 500 la->la_hold = 0; 501 } 502 } 503reply: 504 if (op != ARPOP_REQUEST) { 505 m_freem(m); 506 return; 507 } 508 if (itaddr.s_addr == myaddr.s_addr) { 509 /* I am the target */ 510 (void)memcpy(ea->arp_tha, ea->arp_sha, sizeof(ea->arp_sha)); 511 (void)memcpy(ea->arp_sha, ac->ac_enaddr, sizeof(ea->arp_sha)); 512 } else { 513 la = arplookup(itaddr.s_addr, 0, SIN_PROXY); 514 if (la == NULL) { 515 struct sockaddr_in sin; 516 517 if (!arp_proxyall) { 518 m_freem(m); 519 return; 520 } 521 522 bzero(&sin, sizeof sin); 523 sin.sin_family = AF_INET; 524 sin.sin_len = sizeof sin; 525 sin.sin_addr = itaddr; 526 527 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL); 528 if (!rt) { 529 m_freem(m); 530 return; 531 } 532 /* 533 * Don't send proxies for nodes on the same interface 534 * as this one came out of, or we'll get into a fight 535 * over who claims what Ether address. 536 */ 537 if (rt->rt_ifp == &ac->ac_if) { 538 rtfree(rt); 539 m_freem(m); 540 return; 541 } 542 (void)memcpy(ea->arp_tha, ea->arp_sha, sizeof(ea->arp_sha)); 543 (void)memcpy(ea->arp_sha, ac->ac_enaddr, sizeof(ea->arp_sha)); 544 rtfree(rt); 545#ifdef DEBUG_PROXY 546 printf("arp: proxying for %s\n", 547 inet_ntoa(itaddr)); 548#endif 549 } else { 550 rt = la->la_rt; 551 (void)memcpy(ea->arp_tha, ea->arp_sha, sizeof(ea->arp_sha)); 552 sdl = SDL(rt->rt_gateway); 553 (void)memcpy(ea->arp_sha, LLADDR(sdl), sizeof(ea->arp_sha)); 554 } 555 } 556 557 (void)memcpy(ea->arp_tpa, ea->arp_spa, sizeof(ea->arp_spa)); 558 (void)memcpy(ea->arp_spa, &itaddr, sizeof(ea->arp_spa)); 559 ea->arp_op = htons(ARPOP_REPLY); 560 ea->arp_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 561 eh = (struct ether_header *)sa.sa_data; 562 (void)memcpy(eh->ether_dhost, ea->arp_tha, sizeof(eh->ether_dhost)); 563 eh->ether_type = htons(ETHERTYPE_ARP); 564 sa.sa_family = AF_UNSPEC; 565 sa.sa_len = sizeof(sa); 566 (*ac->ac_if.if_output)(&ac->ac_if, m, &sa, (struct rtentry *)0); 567 return; 568} 569 570/* 571 * Free an arp entry. 572 */ 573static void 574arptfree(la) 575 register struct llinfo_arp *la; 576{ 577 register struct rtentry *rt = la->la_rt; 578 register struct sockaddr_dl *sdl; 579 if (rt == 0) 580 panic("arptfree"); 581 if (rt->rt_refcnt > 0 && (sdl = SDL(rt->rt_gateway)) && 582 sdl->sdl_family == AF_LINK) { 583 sdl->sdl_alen = 0; 584 la->la_asked = 0; 585 rt->rt_flags &= ~RTF_REJECT; 586 return; 587 } 588 rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0, rt_mask(rt), 589 0, (struct rtentry **)0); 590} 591/* 592 * Lookup or enter a new address in arptab. 593 */ 594static struct llinfo_arp * 595arplookup(addr, create, proxy) 596 u_long addr; 597 int create, proxy; 598{ 599 register struct rtentry *rt; 600 static struct sockaddr_inarp sin = {sizeof(sin), AF_INET }; 601 const char *why = 0; 602 603 sin.sin_addr.s_addr = addr; 604 sin.sin_other = proxy ? SIN_PROXY : 0; 605 rt = rtalloc1((struct sockaddr *)&sin, create, 0UL); 606 if (rt == 0) 607 return (0); 608 rt->rt_refcnt--; 609 610 if (rt->rt_flags & RTF_GATEWAY) 611 why = "host is not on local network"; 612 else if ((rt->rt_flags & RTF_LLINFO) == 0) 613 why = "could not allocate llinfo"; 614 else if (rt->rt_gateway->sa_family != AF_LINK) 615 why = "gateway route is not ours"; 616 617 if (why && create) { 618 log(LOG_DEBUG, "arplookup %s failed: %s\n", 619 inet_ntoa(sin.sin_addr), why); 620 return 0; 621 } else if (why) { 622 return 0; 623 } 624 return ((struct llinfo_arp *)rt->rt_llinfo); 625} 626 627void 628arp_ifinit(ac, ifa) 629 struct arpcom *ac; 630 struct ifaddr *ifa; 631{ 632 if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY) 633 arprequest(ac, &(IA_SIN(ifa)->sin_addr.s_addr), 634 &(IA_SIN(ifa)->sin_addr.s_addr), ac->ac_enaddr); 635 ifa->ifa_rtrequest = arp_rtrequest; 636 ifa->ifa_flags |= RTF_CLONING; 637} 638