1 /* 2 * Copyright (c) 2004, 2005 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Jeffrey M. Hsu. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of The DragonFly Project nor the names of its 16 * contributors may be used to endorse or promote products derived 17 * from this software without specific, prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 22 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 23 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 24 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 25 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 26 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 27 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 28 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 29 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * Copyright (c) 1982, 1986, 1988, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 3. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * @(#)if_ether.c 8.1 (Berkeley) 6/10/93 62 * $FreeBSD: src/sys/netinet/if_ether.c,v 1.64.2.23 2003/04/11 07:23:15 fjoe Exp $ 63 */ 64 65 /* 66 * Ethernet address resolution protocol. 67 * TODO: 68 * add "inuse/lock" bit (or ref. count) along with valid bit 69 */ 70 71 #include "opt_inet.h" 72 #include "opt_carp.h" 73 74 #include <sys/param.h> 75 #include <sys/kernel.h> 76 #include <sys/queue.h> 77 #include <sys/sysctl.h> 78 #include <sys/systm.h> 79 #include <sys/mbuf.h> 80 #include <sys/malloc.h> 81 #include <sys/socket.h> 82 #include <sys/syslog.h> 83 #include <sys/lock.h> 84 85 #include <net/if.h> 86 #include <net/if_dl.h> 87 #include <net/if_types.h> 88 #include <net/route.h> 89 #include <net/netisr.h> 90 #include <net/if_llc.h> 91 92 #include <netinet/in.h> 93 #include <netinet/in_var.h> 94 #include <netinet/if_ether.h> 95 96 #include <sys/thread2.h> 97 #include <sys/msgport2.h> 98 #include <net/netmsg2.h> 99 #include <net/netisr2.h> 100 #include <sys/mplock2.h> 101 102 #ifdef CARP 103 #include <netinet/ip_carp.h> 104 #endif 105 106 #define SIN(s) ((struct sockaddr_in *)s) 107 #define SDL(s) ((struct sockaddr_dl *)s) 108 109 SYSCTL_DECL(_net_link_ether); 110 SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, ""); 111 112 /* timer values */ 113 static int arpt_prune = (5*60*1); /* walk list every 5 minutes */ 114 static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */ 115 static int arpt_down = 20; /* once declared down, don't send for 20 sec */ 116 117 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, prune_intvl, CTLFLAG_RW, 118 &arpt_prune, 0, ""); 119 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW, 120 &arpt_keep, 0, ""); 121 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, host_down_time, CTLFLAG_RW, 122 &arpt_down, 0, ""); 123 124 #define rt_expire rt_rmx.rmx_expire 125 126 struct llinfo_arp { 127 LIST_ENTRY(llinfo_arp) la_le; 128 struct rtentry *la_rt; 129 struct mbuf *la_hold; /* last packet until resolved/timeout */ 130 u_short la_preempt; /* countdown for pre-expiry arps */ 131 u_short la_asked; /* #times we QUERIED following expiration */ 132 }; 133 134 static LIST_HEAD(, llinfo_arp) llinfo_arp_list[MAXCPU]; 135 136 static int arp_maxtries = 5; 137 static int useloopback = 1; /* use loopback interface for local traffic */ 138 static int arp_proxyall = 0; 139 static int arp_refresh = 60; /* refresh arp cache ~60 (not impl yet) */ 140 static int arp_restricted_match = 0; 141 142 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW, 143 &arp_maxtries, 0, "ARP resolution attempts before returning error"); 144 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW, 145 &useloopback, 0, "Use the loopback interface for local traffic"); 146 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW, 147 &arp_proxyall, 0, "Enable proxy ARP for all suitable requests"); 148 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, restricted_match, CTLFLAG_RW, 149 &arp_restricted_match, 0, "Only match against the sender"); 150 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, refresh, CTLFLAG_RW, 151 &arp_refresh, 0, "Preemptively refresh the ARP"); 152 153 static void arp_rtrequest(int, struct rtentry *); 154 static void arprequest(struct ifnet *, const struct in_addr *, 155 const struct in_addr *, const u_char *); 156 static void arprequest_async(struct ifnet *, const struct in_addr *, 157 const struct in_addr *, const u_char *); 158 static void arpintr(netmsg_t msg); 159 static void arptfree(struct llinfo_arp *); 160 static void arptimer(void *); 161 static struct llinfo_arp * 162 arplookup(in_addr_t, boolean_t, boolean_t, boolean_t); 163 #ifdef INET 164 static void in_arpinput(struct mbuf *); 165 static void in_arpreply(struct mbuf *m, in_addr_t, in_addr_t); 166 static void arp_update_msghandler(netmsg_t); 167 static void arp_reply_msghandler(netmsg_t); 168 #endif 169 170 struct arptimer_ctx { 171 struct callout timer_ch; 172 struct netmsg_base timer_nmsg; 173 int timer_inited; 174 } __cachealign; 175 176 static struct arptimer_ctx arptimer_context[MAXCPU]; 177 178 /* 179 * Timeout routine. Age arp_tab entries periodically. 180 */ 181 static void 182 arptimer_dispatch(netmsg_t nmsg) 183 { 184 struct llinfo_arp *la, *nla; 185 int cpuid = mycpuid; 186 187 /* Reply ASAP */ 188 crit_enter(); 189 lwkt_replymsg(&nmsg->lmsg, 0); 190 crit_exit(); 191 192 LIST_FOREACH_MUTABLE(la, &llinfo_arp_list[cpuid], la_le, nla) { 193 if (la->la_rt->rt_expire && la->la_rt->rt_expire <= time_uptime) 194 arptfree(la); 195 } 196 callout_reset(&arptimer_context[cpuid].timer_ch, arpt_prune * hz, 197 arptimer, NULL); 198 } 199 200 static void 201 arptimer(void *arg __unused) 202 { 203 int cpuid = mycpuid; 204 struct lwkt_msg *lmsg = &arptimer_context[cpuid].timer_nmsg.lmsg; 205 206 crit_enter(); 207 if (lmsg->ms_flags & MSGF_DONE) 208 lwkt_sendmsg_oncpu(netisr_cpuport(cpuid), lmsg); 209 crit_exit(); 210 } 211 212 /* 213 * Parallel to llc_rtrequest. 214 * 215 * Called after a route is successfully added to the tree to fix-up the 216 * route and initiate arp operations if required. 217 */ 218 static void 219 arp_rtrequest(int req, struct rtentry *rt) 220 { 221 struct sockaddr *gate = rt->rt_gateway; 222 struct llinfo_arp *la = rt->rt_llinfo; 223 224 struct sockaddr_dl null_sdl = { sizeof null_sdl, AF_LINK }; 225 226 if (__predict_false(!arptimer_context[mycpuid].timer_inited)) { 227 struct arptimer_ctx *ctx = &arptimer_context[mycpuid]; 228 229 ctx->timer_inited = TRUE; 230 netmsg_init(&ctx->timer_nmsg, NULL, &netisr_adone_rport, 231 MSGF_PRIORITY, arptimer_dispatch); 232 callout_init_mp(&ctx->timer_ch); 233 callout_reset(&ctx->timer_ch, hz, arptimer, NULL); 234 } 235 if (rt->rt_flags & RTF_GATEWAY) 236 return; 237 238 switch (req) { 239 case RTM_ADD: 240 /* 241 * XXX: If this is a manually added route to interface 242 * such as older version of routed or gated might provide, 243 * restore cloning bit. 244 */ 245 if (!(rt->rt_flags & RTF_HOST) && 246 SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff) 247 rt->rt_flags |= RTF_CLONING; 248 if (rt->rt_flags & RTF_CLONING) { 249 /* 250 * Case 1: This route should come from a route to iface. 251 */ 252 rt_setgate(rt, rt_key(rt), 253 (struct sockaddr *)&null_sdl, 254 RTL_DONTREPORT); 255 gate = rt->rt_gateway; 256 SDL(gate)->sdl_type = rt->rt_ifp->if_type; 257 SDL(gate)->sdl_index = rt->rt_ifp->if_index; 258 rt->rt_expire = time_uptime; 259 break; 260 } 261 /* Announce a new entry if requested. */ 262 if (rt->rt_flags & RTF_ANNOUNCE) { 263 arprequest_async(rt->rt_ifp, 264 &SIN(rt_key(rt))->sin_addr, 265 &SIN(rt_key(rt))->sin_addr, 266 LLADDR(SDL(gate))); 267 } 268 /*FALLTHROUGH*/ 269 case RTM_RESOLVE: 270 if (gate->sa_family != AF_LINK || 271 gate->sa_len < sizeof(struct sockaddr_dl)) { 272 log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n"); 273 break; 274 } 275 SDL(gate)->sdl_type = rt->rt_ifp->if_type; 276 SDL(gate)->sdl_index = rt->rt_ifp->if_index; 277 if (la != NULL) 278 break; /* This happens on a route change */ 279 /* 280 * Case 2: This route may come from cloning, or a manual route 281 * add with a LL address. 282 */ 283 R_Malloc(la, struct llinfo_arp *, sizeof *la); 284 rt->rt_llinfo = la; 285 if (la == NULL) { 286 log(LOG_DEBUG, "arp_rtrequest: malloc failed\n"); 287 break; 288 } 289 bzero(la, sizeof *la); 290 la->la_rt = rt; 291 rt->rt_flags |= RTF_LLINFO; 292 LIST_INSERT_HEAD(&llinfo_arp_list[mycpuid], la, la_le); 293 294 #ifdef INET 295 /* 296 * This keeps the multicast addresses from showing up 297 * in `arp -a' listings as unresolved. It's not actually 298 * functional. Then the same for broadcast. 299 */ 300 if (IN_MULTICAST(ntohl(SIN(rt_key(rt))->sin_addr.s_addr))) { 301 ETHER_MAP_IP_MULTICAST(&SIN(rt_key(rt))->sin_addr, 302 LLADDR(SDL(gate))); 303 SDL(gate)->sdl_alen = 6; 304 rt->rt_expire = 0; 305 } 306 if (in_broadcast(SIN(rt_key(rt))->sin_addr, rt->rt_ifp)) { 307 memcpy(LLADDR(SDL(gate)), rt->rt_ifp->if_broadcastaddr, 308 rt->rt_ifp->if_addrlen); 309 SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen; 310 rt->rt_expire = 0; 311 } 312 #endif 313 314 /* 315 * This fixes up the routing interface for local addresses. 316 * The route is adjusted to point at lo0 and the expiration 317 * timer is disabled. 318 * 319 * NOTE: This prevents locally targetted traffic from going 320 * out the hardware interface, which is inefficient 321 * and might not work if the hardware cannot listen 322 * to its own transmitted packets. Setting 323 * net.link.ether.inet.useloopback to 0 will force 324 * packets for local addresses out the hardware (and 325 * it is expected to receive its own packet). 326 * 327 * XXX We should just be able to test RTF_LOCAL here instead 328 * of having to compare IPs. 329 */ 330 if (SIN(rt_key(rt))->sin_addr.s_addr == 331 (IA_SIN(rt->rt_ifa))->sin_addr.s_addr) { 332 rt->rt_expire = 0; 333 bcopy(IF_LLADDR(rt->rt_ifp), LLADDR(SDL(gate)), 334 SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen); 335 if (useloopback) 336 rt->rt_ifp = loif; 337 } 338 break; 339 340 case RTM_DELETE: 341 if (la == NULL) 342 break; 343 LIST_REMOVE(la, la_le); 344 rt->rt_llinfo = NULL; 345 rt->rt_flags &= ~RTF_LLINFO; 346 if (la->la_hold != NULL) 347 m_freem(la->la_hold); 348 Free(la); 349 break; 350 } 351 } 352 353 static struct mbuf * 354 arpreq_alloc(struct ifnet *ifp, const struct in_addr *sip, 355 const struct in_addr *tip, const u_char *enaddr) 356 { 357 struct mbuf *m; 358 struct arphdr *ah; 359 u_short ar_hrd; 360 361 if ((m = m_gethdr(MB_DONTWAIT, MT_DATA)) == NULL) 362 return NULL; 363 m->m_pkthdr.rcvif = NULL; 364 365 switch (ifp->if_type) { 366 case IFT_ETHER: 367 /* 368 * This may not be correct for types not explicitly 369 * listed, but this is our best guess 370 */ 371 default: 372 ar_hrd = htons(ARPHRD_ETHER); 373 374 m->m_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr)); 375 m->m_pkthdr.len = m->m_len; 376 MH_ALIGN(m, m->m_len); 377 378 ah = mtod(m, struct arphdr *); 379 break; 380 } 381 382 ah->ar_hrd = ar_hrd; 383 ah->ar_pro = htons(ETHERTYPE_IP); 384 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 385 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 386 ah->ar_op = htons(ARPOP_REQUEST); 387 memcpy(ar_sha(ah), enaddr, ah->ar_hln); 388 memset(ar_tha(ah), 0, ah->ar_hln); 389 memcpy(ar_spa(ah), sip, ah->ar_pln); 390 memcpy(ar_tpa(ah), tip, ah->ar_pln); 391 392 return m; 393 } 394 395 static void 396 arpreq_send(struct ifnet *ifp, struct mbuf *m) 397 { 398 struct sockaddr sa; 399 struct ether_header *eh; 400 401 switch (ifp->if_type) { 402 case IFT_ETHER: 403 /* 404 * This may not be correct for types not explicitly 405 * listed, but this is our best guess 406 */ 407 default: 408 eh = (struct ether_header *)sa.sa_data; 409 /* if_output() will not swap */ 410 eh->ether_type = htons(ETHERTYPE_ARP); 411 memcpy(eh->ether_dhost, ifp->if_broadcastaddr, ifp->if_addrlen); 412 break; 413 } 414 415 sa.sa_family = AF_UNSPEC; 416 sa.sa_len = sizeof(sa); 417 ifp->if_output(ifp, m, &sa, NULL); 418 } 419 420 static void 421 arpreq_send_handler(netmsg_t msg) 422 { 423 struct mbuf *m = msg->packet.nm_packet; 424 struct ifnet *ifp = msg->lmsg.u.ms_resultp; 425 426 arpreq_send(ifp, m); 427 /* nmsg was embedded in the mbuf, do not reply! */ 428 } 429 430 /* 431 * Broadcast an ARP request. Caller specifies: 432 * - arp header source ip address 433 * - arp header target ip address 434 * - arp header source ethernet address 435 * 436 * NOTE: Caller MUST NOT hold ifp's serializer 437 */ 438 static void 439 arprequest(struct ifnet *ifp, const struct in_addr *sip, 440 const struct in_addr *tip, const u_char *enaddr) 441 { 442 struct mbuf *m; 443 444 if (enaddr == NULL) { 445 if (ifp->if_bridge) { 446 enaddr = IF_LLADDR(ether_bridge_interface(ifp)); 447 } else { 448 enaddr = IF_LLADDR(ifp); 449 } 450 } 451 452 m = arpreq_alloc(ifp, sip, tip, enaddr); 453 if (m == NULL) 454 return; 455 arpreq_send(ifp, m); 456 } 457 458 /* 459 * Same as arprequest(), except: 460 * - Caller is allowed to hold ifp's serializer 461 * - Network output is done in protocol thead 462 */ 463 static void 464 arprequest_async(struct ifnet *ifp, const struct in_addr *sip, 465 const struct in_addr *tip, const u_char *enaddr) 466 { 467 struct mbuf *m; 468 struct netmsg_packet *pmsg; 469 470 if (enaddr == NULL) { 471 if (ifp->if_bridge) { 472 enaddr = IF_LLADDR(ether_bridge_interface(ifp)); 473 } else { 474 enaddr = IF_LLADDR(ifp); 475 } 476 } 477 m = arpreq_alloc(ifp, sip, tip, enaddr); 478 if (m == NULL) 479 return; 480 481 pmsg = &m->m_hdr.mh_netmsg; 482 netmsg_init(&pmsg->base, NULL, &netisr_apanic_rport, 483 0, arpreq_send_handler); 484 pmsg->nm_packet = m; 485 pmsg->base.lmsg.u.ms_resultp = ifp; 486 487 lwkt_sendmsg_oncpu(netisr_cpuport(mycpuid), &pmsg->base.lmsg); 488 } 489 490 /* 491 * Resolve an IP address into an ethernet address. If success, 492 * desten is filled in. If there is no entry in arptab, 493 * set one up and broadcast a request for the IP address. 494 * Hold onto this mbuf and resend it once the address 495 * is finally resolved. A return value of 1 indicates 496 * that desten has been filled in and the packet should be sent 497 * normally; a 0 return indicates that the packet has been 498 * taken over here, either now or for later transmission. 499 */ 500 int 501 arpresolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m, 502 struct sockaddr *dst, u_char *desten) 503 { 504 struct rtentry *rt = NULL; 505 struct llinfo_arp *la = NULL; 506 struct sockaddr_dl *sdl; 507 508 if (m->m_flags & M_BCAST) { /* broadcast */ 509 memcpy(desten, ifp->if_broadcastaddr, ifp->if_addrlen); 510 return (1); 511 } 512 if (m->m_flags & M_MCAST) {/* multicast */ 513 ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten); 514 return (1); 515 } 516 if (rt0 != NULL) { 517 if (rt_llroute(dst, rt0, &rt) != 0) { 518 m_freem(m); 519 return 0; 520 } 521 la = rt->rt_llinfo; 522 } 523 if (la == NULL) { 524 la = arplookup(SIN(dst)->sin_addr.s_addr, 525 TRUE, RTL_REPORTMSG, FALSE); 526 if (la != NULL) 527 rt = la->la_rt; 528 } 529 if (la == NULL || rt == NULL) { 530 log(LOG_DEBUG, "arpresolve: can't allocate llinfo for %s%s%s\n", 531 inet_ntoa(SIN(dst)->sin_addr), la ? "la" : " ", 532 rt ? "rt" : ""); 533 m_freem(m); 534 return (0); 535 } 536 sdl = SDL(rt->rt_gateway); 537 /* 538 * Check the address family and length is valid, the address 539 * is resolved; otherwise, try to resolve. 540 */ 541 if ((rt->rt_expire == 0 || rt->rt_expire > time_uptime) && 542 sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) { 543 /* 544 * If entry has an expiry time and it is approaching, 545 * see if we need to send an ARP request within this 546 * arpt_down interval. 547 */ 548 if ((rt->rt_expire != 0) && 549 (time_uptime + la->la_preempt > rt->rt_expire)) { 550 arprequest(ifp, 551 &SIN(rt->rt_ifa->ifa_addr)->sin_addr, 552 &SIN(dst)->sin_addr, 553 NULL); 554 la->la_preempt--; 555 } 556 557 bcopy(LLADDR(sdl), desten, sdl->sdl_alen); 558 return 1; 559 } 560 /* 561 * If ARP is disabled or static on this interface, stop. 562 * XXX 563 * Probably should not allocate empty llinfo struct if we are 564 * not going to be sending out an arp request. 565 */ 566 if (ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) { 567 m_freem(m); 568 return (0); 569 } 570 /* 571 * There is an arptab entry, but no ethernet address 572 * response yet. Replace the held mbuf with this 573 * latest one. 574 */ 575 if (la->la_hold != NULL) 576 m_freem(la->la_hold); 577 la->la_hold = m; 578 if (rt->rt_expire || ((rt->rt_flags & RTF_STATIC) && !sdl->sdl_alen)) { 579 rt->rt_flags &= ~RTF_REJECT; 580 if (la->la_asked == 0 || rt->rt_expire != time_uptime) { 581 rt->rt_expire = time_uptime; 582 if (la->la_asked++ < arp_maxtries) { 583 arprequest(ifp, 584 &SIN(rt->rt_ifa->ifa_addr)->sin_addr, 585 &SIN(dst)->sin_addr, 586 NULL); 587 } else { 588 rt->rt_flags |= RTF_REJECT; 589 rt->rt_expire += arpt_down; 590 la->la_asked = 0; 591 la->la_preempt = arp_maxtries; 592 } 593 } 594 } 595 return (0); 596 } 597 598 /* 599 * Common length and type checks are done here, 600 * then the protocol-specific routine is called. 601 */ 602 static void 603 arpintr(netmsg_t msg) 604 { 605 struct mbuf *m = msg->packet.nm_packet; 606 struct arphdr *ar; 607 u_short ar_hrd; 608 char hexstr[6]; 609 610 if (m->m_len < sizeof(struct arphdr) && 611 (m = m_pullup(m, sizeof(struct arphdr))) == NULL) { 612 log(LOG_ERR, "arp: runt packet -- m_pullup failed\n"); 613 return; 614 } 615 ar = mtod(m, struct arphdr *); 616 617 ar_hrd = ntohs(ar->ar_hrd); 618 if (ar_hrd != ARPHRD_ETHER && ar_hrd != ARPHRD_IEEE802) { 619 hexncpy((unsigned char *)&ar->ar_hrd, 2, hexstr, 5, NULL); 620 log(LOG_ERR, "arp: unknown hardware address format (0x%s)\n", 621 hexstr); 622 m_freem(m); 623 return; 624 } 625 626 if (m->m_pkthdr.len < arphdr_len(ar)) { 627 if ((m = m_pullup(m, arphdr_len(ar))) == NULL) { 628 log(LOG_ERR, "arp: runt packet\n"); 629 return; 630 } 631 ar = mtod(m, struct arphdr *); 632 } 633 634 switch (ntohs(ar->ar_pro)) { 635 #ifdef INET 636 case ETHERTYPE_IP: 637 in_arpinput(m); 638 return; 639 #endif 640 } 641 m_freem(m); 642 /* msg was embedded in the mbuf, do not reply! */ 643 } 644 645 #ifdef INET 646 /* 647 * ARP for Internet protocols on 10 Mb/s Ethernet. 648 * Algorithm is that given in RFC 826. 649 * In addition, a sanity check is performed on the sender 650 * protocol address, to catch impersonators. 651 * We no longer handle negotiations for use of trailer protocol: 652 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent 653 * along with IP replies if we wanted trailers sent to us, 654 * and also sent them in response to IP replies. 655 * This allowed either end to announce the desire to receive 656 * trailer packets. 657 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, 658 * but formerly didn't normally send requests. 659 */ 660 661 static int log_arp_wrong_iface = 1; 662 static int log_arp_movements = 1; 663 static int log_arp_permanent_modify = 1; 664 665 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW, 666 &log_arp_wrong_iface, 0, 667 "Log arp packets arriving on the wrong interface"); 668 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_movements, CTLFLAG_RW, 669 &log_arp_movements, 0, 670 "Log arp replies from MACs different than the one in the cache"); 671 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_permanent_modify, CTLFLAG_RW, 672 &log_arp_permanent_modify, 0, 673 "Log arp replies from MACs different than the one " 674 "in the permanent arp entry"); 675 676 static void 677 arp_update_oncpu(struct mbuf *m, in_addr_t saddr, boolean_t create, 678 boolean_t generate_report, boolean_t dologging) 679 { 680 struct arphdr *ah = mtod(m, struct arphdr *); 681 struct ifnet *ifp = m->m_pkthdr.rcvif; 682 struct llinfo_arp *la; 683 struct sockaddr_dl *sdl; 684 struct rtentry *rt; 685 char hexstr[2][64]; 686 687 KASSERT(curthread->td_type == TD_TYPE_NETISR, 688 ("arp update not in netisr")); 689 690 la = arplookup(saddr, create, generate_report, FALSE); 691 if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) { 692 struct in_addr isaddr = { saddr }; 693 694 /* 695 * Normally arps coming in on the wrong interface are ignored, 696 * but if we are bridging and the two interfaces belong to 697 * the same bridge, or one is a member of the bridge which 698 * is the other, then it isn't an error. 699 */ 700 if (rt->rt_ifp != ifp) { 701 /* 702 * (1) ifp and rt_ifp both members of same bridge 703 * (2) rt_ifp member of bridge ifp 704 * (3) ifp member of bridge rt_ifp 705 * 706 * Always replace rt_ifp with the bridge ifc. 707 */ 708 struct ifnet *nifp; 709 710 if (ifp->if_bridge && 711 rt->rt_ifp->if_bridge == ifp->if_bridge) { 712 nifp = ether_bridge_interface(ifp); 713 } else if (rt->rt_ifp->if_bridge && 714 ether_bridge_interface(rt->rt_ifp) == ifp) { 715 nifp = ifp; 716 } else if (ifp->if_bridge && 717 ether_bridge_interface(ifp) == rt->rt_ifp) { 718 nifp = rt->rt_ifp; 719 } else { 720 nifp = NULL; 721 } 722 723 if ((log_arp_wrong_iface == 1 && nifp == NULL) || 724 log_arp_wrong_iface == 2) { 725 hexncpy((u_char *)ar_sha(ah), ifp->if_addrlen, 726 hexstr[0], HEX_NCPYLEN(ifp->if_addrlen), ":"); 727 log(LOG_ERR, 728 "arp: %s is on %s " 729 "but got reply from %s on %s\n", 730 inet_ntoa(isaddr), 731 rt->rt_ifp->if_xname, hexstr[0], 732 ifp->if_xname); 733 } 734 if (nifp == NULL) 735 return; 736 737 /* 738 * nifp is our man! Replace rt_ifp and adjust 739 * the sdl. 740 */ 741 ifp = rt->rt_ifp = nifp; 742 sdl->sdl_type = ifp->if_type; 743 sdl->sdl_index = ifp->if_index; 744 } 745 if (sdl->sdl_alen && 746 bcmp(ar_sha(ah), LLADDR(sdl), sdl->sdl_alen)) { 747 if (rt->rt_expire != 0) { 748 if (dologging && log_arp_movements) { 749 hexncpy((u_char *)LLADDR(sdl), ifp->if_addrlen, 750 hexstr[0], HEX_NCPYLEN(ifp->if_addrlen), ":"); 751 hexncpy((u_char *)ar_sha(ah), ifp->if_addrlen, 752 hexstr[1], HEX_NCPYLEN(ifp->if_addrlen), ":"); 753 log(LOG_INFO, 754 "arp: %s moved from %s to %s on %s\n", 755 inet_ntoa(isaddr), hexstr[0], hexstr[1], 756 ifp->if_xname); 757 } 758 } else { 759 if (dologging && log_arp_permanent_modify) { 760 hexncpy((u_char *)ar_sha(ah), ifp->if_addrlen, 761 hexstr[0], HEX_NCPYLEN(ifp->if_addrlen), ":"); 762 log(LOG_ERR, 763 "arp: %s attempts to modify " 764 "permanent entry for %s on %s\n", 765 hexstr[0], inet_ntoa(isaddr), ifp->if_xname); 766 } 767 return; 768 } 769 } 770 /* 771 * sanity check for the address length. 772 * XXX this does not work for protocols with variable address 773 * length. -is 774 */ 775 if (dologging && sdl->sdl_alen && sdl->sdl_alen != ah->ar_hln) { 776 hexncpy((u_char *)ar_sha(ah), ifp->if_addrlen, 777 hexstr[0], HEX_NCPYLEN(ifp->if_addrlen), ":"); 778 log(LOG_WARNING, 779 "arp from %s: new addr len %d, was %d", 780 hexstr[0], ah->ar_hln, sdl->sdl_alen); 781 } 782 if (ifp->if_addrlen != ah->ar_hln) { 783 if (dologging) { 784 hexncpy((u_char *)ar_sha(ah), ifp->if_addrlen, 785 hexstr[0], HEX_NCPYLEN(ifp->if_addrlen), ":"); 786 log(LOG_WARNING, 787 "arp from %s: addr len: new %d, i/f %d " 788 "(ignored)", hexstr[0], 789 ah->ar_hln, ifp->if_addrlen); 790 } 791 return; 792 } 793 memcpy(LLADDR(sdl), ar_sha(ah), sdl->sdl_alen = ah->ar_hln); 794 if (rt->rt_expire != 0) { 795 rt->rt_expire = time_uptime + arpt_keep; 796 } 797 rt->rt_flags &= ~RTF_REJECT; 798 la->la_asked = 0; 799 la->la_preempt = arp_maxtries; 800 801 /* 802 * This particular cpu might have been holding an mbuf 803 * pending ARP resolution. If so, transmit the mbuf now. 804 */ 805 if (la->la_hold != NULL) { 806 struct mbuf *m = la->la_hold; 807 808 la->la_hold = NULL; 809 m_adj(m, sizeof(struct ether_header)); 810 ifp->if_output(ifp, m, rt_key(rt), rt); 811 } 812 } 813 } 814 815 /* 816 * Called from arpintr() - this routine is run from a single cpu. 817 */ 818 static void 819 in_arpinput(struct mbuf *m) 820 { 821 struct arphdr *ah; 822 struct ifnet *ifp = m->m_pkthdr.rcvif; 823 struct ifaddr_container *ifac; 824 struct in_ifaddr_container *iac; 825 struct in_ifaddr *ia = NULL; 826 struct in_addr isaddr, itaddr, myaddr; 827 uint8_t *enaddr = NULL; 828 int req_len; 829 char hexstr[64]; 830 831 req_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr)); 832 if (m->m_len < req_len && (m = m_pullup(m, req_len)) == NULL) { 833 log(LOG_ERR, "in_arp: runt packet -- m_pullup failed\n"); 834 return; 835 } 836 837 ah = mtod(m, struct arphdr *); 838 memcpy(&isaddr, ar_spa(ah), sizeof isaddr); 839 memcpy(&itaddr, ar_tpa(ah), sizeof itaddr); 840 841 /* 842 * Check both target and sender IP addresses: 843 * 844 * If we receive the packet on the interface owning the address, 845 * then accept the address. 846 * 847 * For a bridge, we accept the address if the receive interface and 848 * the interface owning the address are on the same bridge, and 849 * use the bridge MAC as the is-at response. The bridge will be 850 * responsible for handling the packet. 851 * 852 * (0) Check target IP against CARP IPs 853 */ 854 #ifdef CARP 855 LIST_FOREACH(iac, INADDR_HASH(itaddr.s_addr), ia_hash) { 856 int is_match = 0, is_parent = 0; 857 858 ia = iac->ia; 859 860 /* Skip all ia's which don't match */ 861 if (itaddr.s_addr != ia->ia_addr.sin_addr.s_addr) 862 continue; 863 864 if (ia->ia_ifp->if_type != IFT_CARP) 865 continue; 866 867 if (carp_parent(ia->ia_ifp) == ifp) 868 is_parent = 1; 869 if (is_parent || ia->ia_ifp == ifp) 870 is_match = carp_iamatch(ia); 871 872 if (is_match) { 873 if (is_parent) { 874 /* 875 * The parent interface will also receive 876 * the ethernet broadcast packets, e.g. ARP 877 * REQUEST, so if we could find a CARP 878 * interface of the parent that could match 879 * the target IP address, we then drop the 880 * packets, which is delieverd to us through 881 * the parent interface. 882 */ 883 m_freem(m); 884 return; 885 } 886 goto match; 887 } 888 } 889 #endif /* CARP */ 890 891 /* 892 * (1) Check target IP against our local IPs 893 */ 894 LIST_FOREACH(iac, INADDR_HASH(itaddr.s_addr), ia_hash) { 895 ia = iac->ia; 896 897 /* Skip all ia's which don't match */ 898 if (itaddr.s_addr != ia->ia_addr.sin_addr.s_addr) 899 continue; 900 901 #ifdef CARP 902 /* CARP interfaces are checked in (0) */ 903 if (ia->ia_ifp->if_type == IFT_CARP) 904 continue; 905 #endif 906 907 if (ifp->if_bridge && ia->ia_ifp && 908 ifp->if_bridge == ia->ia_ifp->if_bridge) { 909 ifp = ether_bridge_interface(ifp); 910 goto match; 911 } 912 if (ia->ia_ifp && ia->ia_ifp->if_bridge && 913 ether_bridge_interface(ia->ia_ifp) == ifp) { 914 goto match; 915 } 916 if (ifp->if_bridge && ether_bridge_interface(ifp) == 917 ia->ia_ifp) { 918 goto match; 919 } 920 if (ia->ia_ifp == ifp) { 921 goto match; 922 } 923 } 924 925 /* 926 * (2) Check sender IP against our local IPs 927 */ 928 LIST_FOREACH(iac, INADDR_HASH(isaddr.s_addr), ia_hash) { 929 ia = iac->ia; 930 931 /* Skip all ia's which don't match */ 932 if (isaddr.s_addr != ia->ia_addr.sin_addr.s_addr) 933 continue; 934 935 if (ifp->if_bridge && ia->ia_ifp && 936 ifp->if_bridge == ia->ia_ifp->if_bridge) { 937 ifp = ether_bridge_interface(ifp); 938 goto match; 939 } 940 if (ia->ia_ifp && ia->ia_ifp->if_bridge && 941 ether_bridge_interface(ia->ia_ifp) == ifp) { 942 goto match; 943 } 944 if (ifp->if_bridge && ether_bridge_interface(ifp) == 945 ia->ia_ifp) { 946 goto match; 947 } 948 949 if (ia->ia_ifp == ifp) 950 goto match; 951 } 952 953 /* 954 * No match, use the first inet address on the receive interface 955 * as a dummy address for the rest of the function. 956 */ 957 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) { 958 struct ifaddr *ifa = ifac->ifa; 959 960 if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET) { 961 ia = ifatoia(ifa); 962 goto match; 963 } 964 } 965 966 /* 967 * If we got here, we didn't find any suitable interface, 968 * so drop the packet. 969 */ 970 m_freem(m); 971 return; 972 973 match: 974 if (!enaddr) 975 enaddr = (uint8_t *)IF_LLADDR(ifp); 976 myaddr = ia->ia_addr.sin_addr; 977 if (!bcmp(ar_sha(ah), enaddr, ifp->if_addrlen)) { 978 m_freem(m); /* it's from me, ignore it. */ 979 return; 980 } 981 if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 982 log(LOG_ERR, 983 "arp: link address is broadcast for IP address %s!\n", 984 inet_ntoa(isaddr)); 985 m_freem(m); 986 return; 987 } 988 if (isaddr.s_addr == myaddr.s_addr && myaddr.s_addr != 0) { 989 hexncpy((u_char *)ar_sha(ah), ifp->if_addrlen, 990 hexstr, HEX_NCPYLEN(ifp->if_addrlen), ":"); 991 log(LOG_ERR, 992 "arp: %s is using my IP address %s!\n", 993 hexstr, inet_ntoa(isaddr)); 994 itaddr = myaddr; 995 goto reply; 996 } 997 if (ifp->if_flags & IFF_STATICARP) 998 goto reply; 999 1000 /* 1001 * When arp_restricted_match is true and the ARP response is not 1002 * specifically targetted to me, ignore it. Otherwise the entry 1003 * timeout may be updated for an old MAC. 1004 */ 1005 if (arp_restricted_match && itaddr.s_addr != myaddr.s_addr) { 1006 m_freem(m); 1007 return; 1008 } 1009 1010 /* 1011 * Update all CPU's routing tables with this ARP packet. 1012 * 1013 * However, we only need to generate rtmsg on CPU0. 1014 */ 1015 KASSERT(&curthread->td_msgport == netisr_cpuport(0), 1016 ("arp input not in netisr0, but on cpu%d", mycpuid)); 1017 arp_update_oncpu(m, isaddr.s_addr, itaddr.s_addr == myaddr.s_addr, 1018 RTL_REPORTMSG, TRUE); 1019 1020 if (ncpus > 1) { 1021 struct netmsg_inarp *msg = &m->m_hdr.mh_arpmsg; 1022 1023 netmsg_init(&msg->base, NULL, &netisr_apanic_rport, 1024 0, arp_update_msghandler); 1025 msg->m = m; 1026 msg->saddr = isaddr.s_addr; 1027 msg->taddr = itaddr.s_addr; 1028 msg->myaddr = myaddr.s_addr; 1029 lwkt_sendmsg(netisr_cpuport(1), &msg->base.lmsg); 1030 } else { 1031 goto reply; 1032 } 1033 1034 /* 1035 * Just return here; after all CPUs's routing tables are 1036 * properly updated by this ARP packet, an ARP reply will 1037 * be generated if appropriate. 1038 */ 1039 return; 1040 reply: 1041 in_arpreply(m, itaddr.s_addr, myaddr.s_addr); 1042 } 1043 1044 static void 1045 arp_reply_msghandler(netmsg_t msg) 1046 { 1047 struct netmsg_inarp *rmsg = (struct netmsg_inarp *)msg; 1048 1049 in_arpreply(rmsg->m, rmsg->taddr, rmsg->myaddr); 1050 /* Don't reply this netmsg; netmsg_inarp is embedded in mbuf */ 1051 } 1052 1053 static void 1054 arp_update_msghandler(netmsg_t msg) 1055 { 1056 struct netmsg_inarp *rmsg = (struct netmsg_inarp *)msg; 1057 int nextcpu; 1058 1059 /* 1060 * This message handler will be called on all of the APs; 1061 * no need to generate rtmsg on them. 1062 */ 1063 KASSERT(mycpuid > 0, ("arp update msg on cpu%d", mycpuid)); 1064 arp_update_oncpu(rmsg->m, rmsg->saddr, rmsg->taddr == rmsg->myaddr, 1065 RTL_DONTREPORT, FALSE); 1066 1067 nextcpu = mycpuid + 1; 1068 if (nextcpu < ncpus) { 1069 lwkt_forwardmsg(netisr_cpuport(nextcpu), &rmsg->base.lmsg); 1070 } else { 1071 struct mbuf *m = rmsg->m; 1072 in_addr_t saddr = rmsg->saddr; 1073 in_addr_t taddr = rmsg->taddr; 1074 in_addr_t myaddr = rmsg->myaddr; 1075 1076 /* 1077 * Dispatch this mbuf to netisr0 to perform ARP reply, 1078 * if appropriate. 1079 * NOTE: netmsg_inarp is embedded in this mbuf. 1080 */ 1081 netmsg_init(&rmsg->base, NULL, &netisr_apanic_rport, 1082 0, arp_reply_msghandler); 1083 rmsg->m = m; 1084 rmsg->saddr = saddr; 1085 rmsg->taddr = taddr; 1086 rmsg->myaddr = myaddr; 1087 lwkt_sendmsg(netisr_cpuport(0), &rmsg->base.lmsg); 1088 } 1089 } 1090 1091 static void 1092 in_arpreply(struct mbuf *m, in_addr_t taddr, in_addr_t myaddr) 1093 { 1094 struct ifnet *ifp = m->m_pkthdr.rcvif; 1095 const uint8_t *enaddr; 1096 struct arphdr *ah; 1097 struct sockaddr sa; 1098 struct ether_header *eh; 1099 1100 ah = mtod(m, struct arphdr *); 1101 if (ntohs(ah->ar_op) != ARPOP_REQUEST) { 1102 m_freem(m); 1103 return; 1104 } 1105 1106 enaddr = (const uint8_t *)IF_LLADDR(ifp); 1107 if (taddr == myaddr) { 1108 /* I am the target */ 1109 memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); 1110 memcpy(ar_sha(ah), enaddr, ah->ar_hln); 1111 } else { 1112 struct llinfo_arp *la; 1113 struct rtentry *rt; 1114 1115 la = arplookup(taddr, FALSE, RTL_DONTREPORT, SIN_PROXY); 1116 if (la == NULL) { 1117 struct sockaddr_in sin; 1118 1119 if (!arp_proxyall) { 1120 m_freem(m); 1121 return; 1122 } 1123 1124 bzero(&sin, sizeof sin); 1125 sin.sin_family = AF_INET; 1126 sin.sin_len = sizeof sin; 1127 sin.sin_addr.s_addr = taddr; 1128 1129 rt = rtpurelookup((struct sockaddr *)&sin); 1130 if (rt == NULL) { 1131 m_freem(m); 1132 return; 1133 } 1134 --rt->rt_refcnt; 1135 /* 1136 * Don't send proxies for nodes on the same interface 1137 * as this one came out of, or we'll get into a fight 1138 * over who claims what Ether address. 1139 */ 1140 if (rt->rt_ifp == ifp) { 1141 m_freem(m); 1142 return; 1143 } 1144 memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); 1145 memcpy(ar_sha(ah), enaddr, ah->ar_hln); 1146 #ifdef DEBUG_PROXY 1147 kprintf("arp: proxying for %s\n", inet_ntoa(itaddr)); 1148 #endif 1149 } else { 1150 struct sockaddr_dl *sdl; 1151 1152 rt = la->la_rt; 1153 memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); 1154 sdl = SDL(rt->rt_gateway); 1155 memcpy(ar_sha(ah), LLADDR(sdl), ah->ar_hln); 1156 } 1157 } 1158 1159 memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); 1160 memcpy(ar_spa(ah), &taddr, ah->ar_pln); 1161 ah->ar_op = htons(ARPOP_REPLY); 1162 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 1163 switch (ifp->if_type) { 1164 case IFT_ETHER: 1165 /* 1166 * May not be correct for types not explictly 1167 * listed, but it is our best guess. 1168 */ 1169 default: 1170 eh = (struct ether_header *)sa.sa_data; 1171 memcpy(eh->ether_dhost, ar_tha(ah), sizeof eh->ether_dhost); 1172 eh->ether_type = htons(ETHERTYPE_ARP); 1173 break; 1174 } 1175 sa.sa_family = AF_UNSPEC; 1176 sa.sa_len = sizeof sa; 1177 ifp->if_output(ifp, m, &sa, NULL); 1178 } 1179 1180 #endif /* INET */ 1181 1182 /* 1183 * Free an arp entry. If the arp entry is actively referenced or represents 1184 * a static entry we only clear it back to an unresolved state, otherwise 1185 * we destroy the entry entirely. 1186 * 1187 * Note that static entries are created when route add ... -interface is used 1188 * to create an interface route to a (direct) destination. 1189 */ 1190 static void 1191 arptfree(struct llinfo_arp *la) 1192 { 1193 struct rtentry *rt = la->la_rt; 1194 struct sockaddr_dl *sdl; 1195 1196 if (rt == NULL) 1197 panic("arptfree"); 1198 sdl = SDL(rt->rt_gateway); 1199 if (sdl != NULL && 1200 ((rt->rt_refcnt > 0 && sdl->sdl_family == AF_LINK) || 1201 (rt->rt_flags & RTF_STATIC))) { 1202 sdl->sdl_alen = 0; 1203 la->la_preempt = la->la_asked = 0; 1204 rt->rt_flags &= ~RTF_REJECT; 1205 return; 1206 } 1207 rtrequest(RTM_DELETE, rt_key(rt), NULL, rt_mask(rt), 0, NULL); 1208 } 1209 1210 /* 1211 * Lookup or enter a new address in arptab. 1212 */ 1213 static struct llinfo_arp * 1214 arplookup(in_addr_t addr, boolean_t create, boolean_t generate_report, 1215 boolean_t proxy) 1216 { 1217 struct rtentry *rt; 1218 struct sockaddr_inarp sin = { sizeof sin, AF_INET }; 1219 const char *why = NULL; 1220 1221 sin.sin_addr.s_addr = addr; 1222 sin.sin_other = proxy ? SIN_PROXY : 0; 1223 if (create) { 1224 rt = _rtlookup((struct sockaddr *)&sin, 1225 generate_report, RTL_DOCLONE); 1226 } else { 1227 rt = rtpurelookup((struct sockaddr *)&sin); 1228 } 1229 if (rt == NULL) 1230 return (NULL); 1231 rt->rt_refcnt--; 1232 1233 if (rt->rt_flags & RTF_GATEWAY) 1234 why = "host is not on local network"; 1235 else if (!(rt->rt_flags & RTF_LLINFO)) 1236 why = "could not allocate llinfo"; 1237 else if (rt->rt_gateway->sa_family != AF_LINK) 1238 why = "gateway route is not ours"; 1239 1240 if (why) { 1241 if (create) { 1242 log(LOG_DEBUG, "arplookup %s failed: %s\n", 1243 inet_ntoa(sin.sin_addr), why); 1244 } 1245 if (rt->rt_refcnt <= 0 && (rt->rt_flags & RTF_WASCLONED)) { 1246 /* No references to this route. Purge it. */ 1247 rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway, 1248 rt_mask(rt), rt->rt_flags, NULL); 1249 } 1250 return (NULL); 1251 } 1252 return (rt->rt_llinfo); 1253 } 1254 1255 void 1256 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1257 { 1258 ifa->ifa_rtrequest = arp_rtrequest; 1259 ifa->ifa_flags |= RTF_CLONING; 1260 } 1261 1262 void 1263 arp_gratuitous(struct ifnet *ifp, struct ifaddr *ifa) 1264 { 1265 if (IA_SIN(ifa)->sin_addr.s_addr != INADDR_ANY) { 1266 arprequest_async(ifp, &IA_SIN(ifa)->sin_addr, 1267 &IA_SIN(ifa)->sin_addr, NULL); 1268 } 1269 } 1270 1271 static void 1272 arp_ifaddr(void *arg __unused, struct ifnet *ifp, 1273 enum ifaddr_event event, struct ifaddr *ifa) 1274 { 1275 if (ifa->ifa_rtrequest != arp_rtrequest) /* XXX need a generic way */ 1276 return; 1277 if (ifa->ifa_addr->sa_family != AF_INET) 1278 return; 1279 if (event == IFADDR_EVENT_DELETE) 1280 return; 1281 1282 /* 1283 * - CARP interfaces will take care of gratuitous ARP themselves. 1284 * - If we are the CARP interface's parent, don't send gratuitous 1285 * ARP to avoid unnecessary confusion. 1286 */ 1287 #ifdef CARP 1288 if (ifp->if_type != IFT_CARP && ifp->if_carp == NULL) 1289 #endif 1290 { 1291 arp_gratuitous(ifp, ifa); 1292 } 1293 } 1294 1295 static void 1296 arp_init(void) 1297 { 1298 int cpu; 1299 1300 for (cpu = 0; cpu < ncpus2; cpu++) 1301 LIST_INIT(&llinfo_arp_list[cpu]); 1302 1303 netisr_register(NETISR_ARP, arpintr, NULL); 1304 1305 EVENTHANDLER_REGISTER(ifaddr_event, arp_ifaddr, NULL, 1306 EVENTHANDLER_PRI_LAST); 1307 } 1308 1309 SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0); 1310