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 /* 262 * Announce a new entry if requested, and only announce it 263 * once on cpu0. 264 */ 265 if ((rt->rt_flags & RTF_ANNOUNCE) && mycpuid == 0) { 266 arprequest_async(rt->rt_ifp, 267 &SIN(rt_key(rt))->sin_addr, 268 &SIN(rt_key(rt))->sin_addr, 269 LLADDR(SDL(gate))); 270 } 271 /*FALLTHROUGH*/ 272 case RTM_RESOLVE: 273 if (gate->sa_family != AF_LINK || 274 gate->sa_len < sizeof(struct sockaddr_dl)) { 275 log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n"); 276 break; 277 } 278 SDL(gate)->sdl_type = rt->rt_ifp->if_type; 279 SDL(gate)->sdl_index = rt->rt_ifp->if_index; 280 if (la != NULL) 281 break; /* This happens on a route change */ 282 /* 283 * Case 2: This route may come from cloning, or a manual route 284 * add with a LL address. 285 */ 286 R_Malloc(la, struct llinfo_arp *, sizeof *la); 287 rt->rt_llinfo = la; 288 if (la == NULL) { 289 log(LOG_DEBUG, "arp_rtrequest: malloc failed\n"); 290 break; 291 } 292 bzero(la, sizeof *la); 293 la->la_rt = rt; 294 rt->rt_flags |= RTF_LLINFO; 295 LIST_INSERT_HEAD(&llinfo_arp_list[mycpuid], la, la_le); 296 297 #ifdef INET 298 /* 299 * This keeps the multicast addresses from showing up 300 * in `arp -a' listings as unresolved. It's not actually 301 * functional. Then the same for broadcast. 302 */ 303 if (IN_MULTICAST(ntohl(SIN(rt_key(rt))->sin_addr.s_addr))) { 304 ETHER_MAP_IP_MULTICAST(&SIN(rt_key(rt))->sin_addr, 305 LLADDR(SDL(gate))); 306 SDL(gate)->sdl_alen = 6; 307 rt->rt_expire = 0; 308 } 309 if (in_broadcast(SIN(rt_key(rt))->sin_addr, rt->rt_ifp)) { 310 memcpy(LLADDR(SDL(gate)), rt->rt_ifp->if_broadcastaddr, 311 rt->rt_ifp->if_addrlen); 312 SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen; 313 rt->rt_expire = 0; 314 } 315 #endif 316 317 /* 318 * This fixes up the routing interface for local addresses. 319 * The route is adjusted to point at lo0 and the expiration 320 * timer is disabled. 321 * 322 * NOTE: This prevents locally targetted traffic from going 323 * out the hardware interface, which is inefficient 324 * and might not work if the hardware cannot listen 325 * to its own transmitted packets. Setting 326 * net.link.ether.inet.useloopback to 0 will force 327 * packets for local addresses out the hardware (and 328 * it is expected to receive its own packet). 329 * 330 * XXX We should just be able to test RTF_LOCAL here instead 331 * of having to compare IPs. 332 */ 333 if (SIN(rt_key(rt))->sin_addr.s_addr == 334 (IA_SIN(rt->rt_ifa))->sin_addr.s_addr) { 335 rt->rt_expire = 0; 336 bcopy(IF_LLADDR(rt->rt_ifp), LLADDR(SDL(gate)), 337 SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen); 338 if (useloopback) 339 rt->rt_ifp = loif; 340 } 341 break; 342 343 case RTM_DELETE: 344 if (la == NULL) 345 break; 346 LIST_REMOVE(la, la_le); 347 rt->rt_llinfo = NULL; 348 rt->rt_flags &= ~RTF_LLINFO; 349 if (la->la_hold != NULL) 350 m_freem(la->la_hold); 351 Free(la); 352 break; 353 } 354 } 355 356 static struct mbuf * 357 arpreq_alloc(struct ifnet *ifp, const struct in_addr *sip, 358 const struct in_addr *tip, const u_char *enaddr) 359 { 360 struct mbuf *m; 361 struct arphdr *ah; 362 u_short ar_hrd; 363 364 if ((m = m_gethdr(M_NOWAIT, MT_DATA)) == NULL) 365 return NULL; 366 m->m_pkthdr.rcvif = NULL; 367 368 switch (ifp->if_type) { 369 case IFT_ETHER: 370 /* 371 * This may not be correct for types not explicitly 372 * listed, but this is our best guess 373 */ 374 default: 375 ar_hrd = htons(ARPHRD_ETHER); 376 377 m->m_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr)); 378 m->m_pkthdr.len = m->m_len; 379 MH_ALIGN(m, m->m_len); 380 381 ah = mtod(m, struct arphdr *); 382 break; 383 } 384 385 ah->ar_hrd = ar_hrd; 386 ah->ar_pro = htons(ETHERTYPE_IP); 387 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 388 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 389 ah->ar_op = htons(ARPOP_REQUEST); 390 memcpy(ar_sha(ah), enaddr, ah->ar_hln); 391 memset(ar_tha(ah), 0, ah->ar_hln); 392 memcpy(ar_spa(ah), sip, ah->ar_pln); 393 memcpy(ar_tpa(ah), tip, ah->ar_pln); 394 395 return m; 396 } 397 398 static void 399 arpreq_send(struct ifnet *ifp, struct mbuf *m) 400 { 401 struct sockaddr sa; 402 struct ether_header *eh; 403 404 switch (ifp->if_type) { 405 case IFT_ETHER: 406 /* 407 * This may not be correct for types not explicitly 408 * listed, but this is our best guess 409 */ 410 default: 411 eh = (struct ether_header *)sa.sa_data; 412 /* if_output() will not swap */ 413 eh->ether_type = htons(ETHERTYPE_ARP); 414 memcpy(eh->ether_dhost, ifp->if_broadcastaddr, ifp->if_addrlen); 415 break; 416 } 417 418 sa.sa_family = AF_UNSPEC; 419 sa.sa_len = sizeof(sa); 420 ifp->if_output(ifp, m, &sa, NULL); 421 } 422 423 static void 424 arpreq_send_handler(netmsg_t msg) 425 { 426 struct mbuf *m = msg->packet.nm_packet; 427 struct ifnet *ifp = msg->lmsg.u.ms_resultp; 428 429 arpreq_send(ifp, m); 430 /* nmsg was embedded in the mbuf, do not reply! */ 431 } 432 433 /* 434 * Broadcast an ARP request. Caller specifies: 435 * - arp header source ip address 436 * - arp header target ip address 437 * - arp header source ethernet address 438 * 439 * NOTE: Caller MUST NOT hold ifp's serializer 440 */ 441 static void 442 arprequest(struct ifnet *ifp, const struct in_addr *sip, 443 const struct in_addr *tip, const u_char *enaddr) 444 { 445 struct mbuf *m; 446 447 if (enaddr == NULL) { 448 if (ifp->if_bridge) { 449 enaddr = IF_LLADDR(ether_bridge_interface(ifp)); 450 } else { 451 enaddr = IF_LLADDR(ifp); 452 } 453 } 454 455 m = arpreq_alloc(ifp, sip, tip, enaddr); 456 if (m == NULL) 457 return; 458 arpreq_send(ifp, m); 459 } 460 461 /* 462 * Same as arprequest(), except: 463 * - Caller is allowed to hold ifp's serializer 464 * - Network output is done in protocol thead 465 */ 466 static void 467 arprequest_async(struct ifnet *ifp, const struct in_addr *sip, 468 const struct in_addr *tip, const u_char *enaddr) 469 { 470 struct mbuf *m; 471 struct netmsg_packet *pmsg; 472 473 if (enaddr == NULL) { 474 if (ifp->if_bridge) { 475 enaddr = IF_LLADDR(ether_bridge_interface(ifp)); 476 } else { 477 enaddr = IF_LLADDR(ifp); 478 } 479 } 480 m = arpreq_alloc(ifp, sip, tip, enaddr); 481 if (m == NULL) 482 return; 483 484 pmsg = &m->m_hdr.mh_netmsg; 485 netmsg_init(&pmsg->base, NULL, &netisr_apanic_rport, 486 0, arpreq_send_handler); 487 pmsg->nm_packet = m; 488 pmsg->base.lmsg.u.ms_resultp = ifp; 489 490 lwkt_sendmsg_oncpu(netisr_cpuport(mycpuid), &pmsg->base.lmsg); 491 } 492 493 /* 494 * Resolve an IP address into an ethernet address. If success, 495 * desten is filled in. If there is no entry in arptab, 496 * set one up and broadcast a request for the IP address. 497 * Hold onto this mbuf and resend it once the address 498 * is finally resolved. A return value of 1 indicates 499 * that desten has been filled in and the packet should be sent 500 * normally; a 0 return indicates that the packet has been 501 * taken over here, either now or for later transmission. 502 */ 503 int 504 arpresolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m, 505 struct sockaddr *dst, u_char *desten) 506 { 507 struct rtentry *rt = NULL; 508 struct llinfo_arp *la = NULL; 509 struct sockaddr_dl *sdl; 510 511 if (m->m_flags & M_BCAST) { /* broadcast */ 512 memcpy(desten, ifp->if_broadcastaddr, ifp->if_addrlen); 513 return (1); 514 } 515 if (m->m_flags & M_MCAST) {/* multicast */ 516 ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten); 517 return (1); 518 } 519 if (rt0 != NULL) { 520 if (rt_llroute(dst, rt0, &rt) != 0) { 521 m_freem(m); 522 return 0; 523 } 524 la = rt->rt_llinfo; 525 } 526 if (la == NULL) { 527 la = arplookup(SIN(dst)->sin_addr.s_addr, 528 TRUE, RTL_REPORTMSG, FALSE); 529 if (la != NULL) 530 rt = la->la_rt; 531 } 532 if (la == NULL || rt == NULL) { 533 log(LOG_DEBUG, "arpresolve: can't allocate llinfo for %s%s%s\n", 534 inet_ntoa(SIN(dst)->sin_addr), la ? "la" : " ", 535 rt ? "rt" : ""); 536 m_freem(m); 537 return (0); 538 } 539 sdl = SDL(rt->rt_gateway); 540 /* 541 * Check the address family and length is valid, the address 542 * is resolved; otherwise, try to resolve. 543 */ 544 if ((rt->rt_expire == 0 || rt->rt_expire > time_uptime) && 545 sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) { 546 /* 547 * If entry has an expiry time and it is approaching, 548 * see if we need to send an ARP request within this 549 * arpt_down interval. 550 */ 551 if ((rt->rt_expire != 0) && 552 (time_uptime + la->la_preempt > rt->rt_expire)) { 553 arprequest(ifp, 554 &SIN(rt->rt_ifa->ifa_addr)->sin_addr, 555 &SIN(dst)->sin_addr, 556 NULL); 557 la->la_preempt--; 558 } 559 560 bcopy(LLADDR(sdl), desten, sdl->sdl_alen); 561 return 1; 562 } 563 /* 564 * If ARP is disabled or static on this interface, stop. 565 * XXX 566 * Probably should not allocate empty llinfo struct if we are 567 * not going to be sending out an arp request. 568 */ 569 if (ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) { 570 m_freem(m); 571 return (0); 572 } 573 /* 574 * There is an arptab entry, but no ethernet address 575 * response yet. Replace the held mbuf with this 576 * latest one. 577 */ 578 if (la->la_hold != NULL) 579 m_freem(la->la_hold); 580 la->la_hold = m; 581 if (rt->rt_expire || ((rt->rt_flags & RTF_STATIC) && !sdl->sdl_alen)) { 582 rt->rt_flags &= ~RTF_REJECT; 583 if (la->la_asked == 0 || rt->rt_expire != time_uptime) { 584 rt->rt_expire = time_uptime; 585 if (la->la_asked++ < arp_maxtries) { 586 arprequest(ifp, 587 &SIN(rt->rt_ifa->ifa_addr)->sin_addr, 588 &SIN(dst)->sin_addr, 589 NULL); 590 } else { 591 rt->rt_flags |= RTF_REJECT; 592 rt->rt_expire += arpt_down; 593 la->la_asked = 0; 594 la->la_preempt = arp_maxtries; 595 } 596 } 597 } 598 return (0); 599 } 600 601 /* 602 * Common length and type checks are done here, 603 * then the protocol-specific routine is called. 604 */ 605 static void 606 arpintr(netmsg_t msg) 607 { 608 struct mbuf *m = msg->packet.nm_packet; 609 struct arphdr *ar; 610 u_short ar_hrd; 611 char hexstr[6]; 612 613 if (m->m_len < sizeof(struct arphdr) && 614 (m = m_pullup(m, sizeof(struct arphdr))) == NULL) { 615 log(LOG_ERR, "arp: runt packet -- m_pullup failed\n"); 616 return; 617 } 618 ar = mtod(m, struct arphdr *); 619 620 ar_hrd = ntohs(ar->ar_hrd); 621 if (ar_hrd != ARPHRD_ETHER && ar_hrd != ARPHRD_IEEE802) { 622 hexncpy((unsigned char *)&ar->ar_hrd, 2, hexstr, 5, NULL); 623 log(LOG_ERR, "arp: unknown hardware address format (0x%s)\n", 624 hexstr); 625 m_freem(m); 626 return; 627 } 628 629 if (m->m_pkthdr.len < arphdr_len(ar)) { 630 if ((m = m_pullup(m, arphdr_len(ar))) == NULL) { 631 log(LOG_ERR, "arp: runt packet\n"); 632 return; 633 } 634 ar = mtod(m, struct arphdr *); 635 } 636 637 switch (ntohs(ar->ar_pro)) { 638 #ifdef INET 639 case ETHERTYPE_IP: 640 in_arpinput(m); 641 return; 642 #endif 643 } 644 m_freem(m); 645 /* msg was embedded in the mbuf, do not reply! */ 646 } 647 648 #ifdef INET 649 /* 650 * ARP for Internet protocols on 10 Mb/s Ethernet. 651 * Algorithm is that given in RFC 826. 652 * In addition, a sanity check is performed on the sender 653 * protocol address, to catch impersonators. 654 * We no longer handle negotiations for use of trailer protocol: 655 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent 656 * along with IP replies if we wanted trailers sent to us, 657 * and also sent them in response to IP replies. 658 * This allowed either end to announce the desire to receive 659 * trailer packets. 660 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, 661 * but formerly didn't normally send requests. 662 */ 663 664 static int log_arp_wrong_iface = 1; 665 static int log_arp_movements = 1; 666 static int log_arp_permanent_modify = 1; 667 static int log_arp_creation_failure = 1; 668 669 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW, 670 &log_arp_wrong_iface, 0, 671 "Log arp packets arriving on the wrong interface"); 672 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_movements, CTLFLAG_RW, 673 &log_arp_movements, 0, 674 "Log arp replies from MACs different than the one in the cache"); 675 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_permanent_modify, CTLFLAG_RW, 676 &log_arp_permanent_modify, 0, 677 "Log arp replies from MACs different than the one " 678 "in the permanent arp entry"); 679 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_creation_failure, CTLFLAG_RW, 680 &log_arp_creation_failure, 0, "Log arp creation failure"); 681 682 static void 683 arp_update_oncpu(struct mbuf *m, in_addr_t saddr, boolean_t create, 684 boolean_t generate_report, boolean_t dologging) 685 { 686 struct arphdr *ah = mtod(m, struct arphdr *); 687 struct ifnet *ifp = m->m_pkthdr.rcvif; 688 struct llinfo_arp *la; 689 struct sockaddr_dl *sdl; 690 struct rtentry *rt; 691 char hexstr[2][64]; 692 693 KASSERT(curthread->td_type == TD_TYPE_NETISR, 694 ("arp update not in netisr")); 695 696 la = arplookup(saddr, create, generate_report, FALSE); 697 if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) { 698 struct in_addr isaddr = { saddr }; 699 700 /* 701 * Normally arps coming in on the wrong interface are ignored, 702 * but if we are bridging and the two interfaces belong to 703 * the same bridge, or one is a member of the bridge which 704 * is the other, then it isn't an error. 705 */ 706 if (rt->rt_ifp != ifp) { 707 /* 708 * (1) ifp and rt_ifp both members of same bridge 709 * (2) rt_ifp member of bridge ifp 710 * (3) ifp member of bridge rt_ifp 711 * 712 * Always replace rt_ifp with the bridge ifc. 713 */ 714 struct ifnet *nifp; 715 716 if (ifp->if_bridge && 717 rt->rt_ifp->if_bridge == ifp->if_bridge) { 718 nifp = ether_bridge_interface(ifp); 719 } else if (rt->rt_ifp->if_bridge && 720 ether_bridge_interface(rt->rt_ifp) == ifp) { 721 nifp = ifp; 722 } else if (ifp->if_bridge && 723 ether_bridge_interface(ifp) == rt->rt_ifp) { 724 nifp = rt->rt_ifp; 725 } else { 726 nifp = NULL; 727 } 728 729 if ((log_arp_wrong_iface == 1 && nifp == NULL) || 730 log_arp_wrong_iface == 2) { 731 hexncpy((u_char *)ar_sha(ah), ifp->if_addrlen, 732 hexstr[0], HEX_NCPYLEN(ifp->if_addrlen), ":"); 733 log(LOG_ERR, 734 "arp: %s is on %s " 735 "but got reply from %s on %s\n", 736 inet_ntoa(isaddr), 737 rt->rt_ifp->if_xname, hexstr[0], 738 ifp->if_xname); 739 } 740 if (nifp == NULL) 741 return; 742 743 /* 744 * nifp is our man! Replace rt_ifp and adjust 745 * the sdl. 746 */ 747 ifp = rt->rt_ifp = nifp; 748 sdl->sdl_type = ifp->if_type; 749 sdl->sdl_index = ifp->if_index; 750 } 751 if (sdl->sdl_alen && 752 bcmp(ar_sha(ah), LLADDR(sdl), sdl->sdl_alen)) { 753 if (rt->rt_expire != 0) { 754 if (dologging && log_arp_movements) { 755 hexncpy((u_char *)LLADDR(sdl), ifp->if_addrlen, 756 hexstr[0], HEX_NCPYLEN(ifp->if_addrlen), ":"); 757 hexncpy((u_char *)ar_sha(ah), ifp->if_addrlen, 758 hexstr[1], HEX_NCPYLEN(ifp->if_addrlen), ":"); 759 log(LOG_INFO, 760 "arp: %s moved from %s to %s on %s\n", 761 inet_ntoa(isaddr), hexstr[0], hexstr[1], 762 ifp->if_xname); 763 } 764 } else { 765 if (dologging && log_arp_permanent_modify) { 766 hexncpy((u_char *)ar_sha(ah), ifp->if_addrlen, 767 hexstr[0], HEX_NCPYLEN(ifp->if_addrlen), ":"); 768 log(LOG_ERR, 769 "arp: %s attempts to modify " 770 "permanent entry for %s on %s\n", 771 hexstr[0], inet_ntoa(isaddr), ifp->if_xname); 772 } 773 return; 774 } 775 } 776 /* 777 * sanity check for the address length. 778 * XXX this does not work for protocols with variable address 779 * length. -is 780 */ 781 if (dologging && sdl->sdl_alen && sdl->sdl_alen != ah->ar_hln) { 782 hexncpy((u_char *)ar_sha(ah), ifp->if_addrlen, 783 hexstr[0], HEX_NCPYLEN(ifp->if_addrlen), ":"); 784 log(LOG_WARNING, 785 "arp from %s: new addr len %d, was %d", 786 hexstr[0], ah->ar_hln, sdl->sdl_alen); 787 } 788 if (ifp->if_addrlen != ah->ar_hln) { 789 if (dologging) { 790 hexncpy((u_char *)ar_sha(ah), ifp->if_addrlen, 791 hexstr[0], HEX_NCPYLEN(ifp->if_addrlen), ":"); 792 log(LOG_WARNING, 793 "arp from %s: addr len: new %d, i/f %d " 794 "(ignored)", hexstr[0], 795 ah->ar_hln, ifp->if_addrlen); 796 } 797 return; 798 } 799 memcpy(LLADDR(sdl), ar_sha(ah), sdl->sdl_alen = ah->ar_hln); 800 if (rt->rt_expire != 0) { 801 rt->rt_expire = time_uptime + arpt_keep; 802 } 803 rt->rt_flags &= ~RTF_REJECT; 804 la->la_asked = 0; 805 la->la_preempt = arp_maxtries; 806 807 /* 808 * This particular cpu might have been holding an mbuf 809 * pending ARP resolution. If so, transmit the mbuf now. 810 */ 811 if (la->la_hold != NULL) { 812 struct mbuf *m = la->la_hold; 813 814 la->la_hold = NULL; 815 m_adj(m, sizeof(struct ether_header)); 816 ifp->if_output(ifp, m, rt_key(rt), rt); 817 } 818 } 819 } 820 821 /* 822 * Called from arpintr() - this routine is run from a single cpu. 823 */ 824 static void 825 in_arpinput(struct mbuf *m) 826 { 827 struct arphdr *ah; 828 struct ifnet *ifp = m->m_pkthdr.rcvif; 829 struct ifaddr_container *ifac; 830 struct in_ifaddr_container *iac; 831 struct in_ifaddr *ia = NULL; 832 struct in_addr isaddr, itaddr, myaddr; 833 uint8_t *enaddr = NULL; 834 int req_len; 835 char hexstr[64]; 836 837 req_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr)); 838 if (m->m_len < req_len && (m = m_pullup(m, req_len)) == NULL) { 839 log(LOG_ERR, "in_arp: runt packet -- m_pullup failed\n"); 840 return; 841 } 842 843 ah = mtod(m, struct arphdr *); 844 memcpy(&isaddr, ar_spa(ah), sizeof isaddr); 845 memcpy(&itaddr, ar_tpa(ah), sizeof itaddr); 846 847 /* 848 * Check both target and sender IP addresses: 849 * 850 * If we receive the packet on the interface owning the address, 851 * then accept the address. 852 * 853 * For a bridge, we accept the address if the receive interface and 854 * the interface owning the address are on the same bridge, and 855 * use the bridge MAC as the is-at response. The bridge will be 856 * responsible for handling the packet. 857 * 858 * (0) Check target IP against CARP IPs 859 */ 860 #ifdef CARP 861 LIST_FOREACH(iac, INADDR_HASH(itaddr.s_addr), ia_hash) { 862 int is_match = 0, is_parent = 0; 863 864 ia = iac->ia; 865 866 /* Skip all ia's which don't match */ 867 if (itaddr.s_addr != ia->ia_addr.sin_addr.s_addr) 868 continue; 869 870 if (ia->ia_ifp->if_type != IFT_CARP) 871 continue; 872 873 if (carp_parent(ia->ia_ifp) == ifp) 874 is_parent = 1; 875 if (is_parent || ia->ia_ifp == ifp) 876 is_match = carp_iamatch(ia); 877 878 if (is_match) { 879 if (is_parent) { 880 /* 881 * The parent interface will also receive 882 * the ethernet broadcast packets, e.g. ARP 883 * REQUEST, so if we could find a CARP 884 * interface of the parent that could match 885 * the target IP address, we then drop the 886 * packets, which is delieverd to us through 887 * the parent interface. 888 */ 889 m_freem(m); 890 return; 891 } 892 goto match; 893 } 894 } 895 #endif /* CARP */ 896 897 /* 898 * (1) Check target IP against our local IPs 899 */ 900 LIST_FOREACH(iac, INADDR_HASH(itaddr.s_addr), ia_hash) { 901 ia = iac->ia; 902 903 /* Skip all ia's which don't match */ 904 if (itaddr.s_addr != ia->ia_addr.sin_addr.s_addr) 905 continue; 906 907 #ifdef CARP 908 /* CARP interfaces are checked in (0) */ 909 if (ia->ia_ifp->if_type == IFT_CARP) 910 continue; 911 #endif 912 913 if (ifp->if_bridge && ia->ia_ifp && 914 ifp->if_bridge == ia->ia_ifp->if_bridge) { 915 ifp = ether_bridge_interface(ifp); 916 goto match; 917 } 918 if (ia->ia_ifp && ia->ia_ifp->if_bridge && 919 ether_bridge_interface(ia->ia_ifp) == ifp) { 920 goto match; 921 } 922 if (ifp->if_bridge && ether_bridge_interface(ifp) == 923 ia->ia_ifp) { 924 goto match; 925 } 926 if (ia->ia_ifp == ifp) { 927 goto match; 928 } 929 } 930 931 /* 932 * (2) Check sender IP against our local IPs 933 */ 934 LIST_FOREACH(iac, INADDR_HASH(isaddr.s_addr), ia_hash) { 935 ia = iac->ia; 936 937 /* Skip all ia's which don't match */ 938 if (isaddr.s_addr != ia->ia_addr.sin_addr.s_addr) 939 continue; 940 941 if (ifp->if_bridge && ia->ia_ifp && 942 ifp->if_bridge == ia->ia_ifp->if_bridge) { 943 ifp = ether_bridge_interface(ifp); 944 goto match; 945 } 946 if (ia->ia_ifp && ia->ia_ifp->if_bridge && 947 ether_bridge_interface(ia->ia_ifp) == ifp) { 948 goto match; 949 } 950 if (ifp->if_bridge && ether_bridge_interface(ifp) == 951 ia->ia_ifp) { 952 goto match; 953 } 954 955 if (ia->ia_ifp == ifp) 956 goto match; 957 } 958 959 /* 960 * No match, use the first inet address on the receive interface 961 * as a dummy address for the rest of the function. 962 */ 963 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) { 964 struct ifaddr *ifa = ifac->ifa; 965 966 if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET) { 967 ia = ifatoia(ifa); 968 goto match; 969 } 970 } 971 972 /* 973 * If we got here, we didn't find any suitable interface, 974 * so drop the packet. 975 */ 976 m_freem(m); 977 return; 978 979 match: 980 if (!enaddr) 981 enaddr = (uint8_t *)IF_LLADDR(ifp); 982 myaddr = ia->ia_addr.sin_addr; 983 if (!bcmp(ar_sha(ah), enaddr, ifp->if_addrlen)) { 984 m_freem(m); /* it's from me, ignore it. */ 985 return; 986 } 987 if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 988 log(LOG_ERR, 989 "arp: link address is broadcast for IP address %s!\n", 990 inet_ntoa(isaddr)); 991 m_freem(m); 992 return; 993 } 994 if (isaddr.s_addr == myaddr.s_addr && myaddr.s_addr != 0) { 995 hexncpy((u_char *)ar_sha(ah), ifp->if_addrlen, 996 hexstr, HEX_NCPYLEN(ifp->if_addrlen), ":"); 997 log(LOG_ERR, 998 "arp: %s is using my IP address %s!\n", 999 hexstr, inet_ntoa(isaddr)); 1000 itaddr = myaddr; 1001 goto reply; 1002 } 1003 if (ifp->if_flags & IFF_STATICARP) 1004 goto reply; 1005 1006 /* 1007 * When arp_restricted_match is true and the ARP response is not 1008 * specifically targetted to me, ignore it. Otherwise the entry 1009 * timeout may be updated for an old MAC. 1010 */ 1011 if (arp_restricted_match && itaddr.s_addr != myaddr.s_addr) { 1012 m_freem(m); 1013 return; 1014 } 1015 1016 /* 1017 * Update all CPU's routing tables with this ARP packet. 1018 * 1019 * However, we only need to generate rtmsg on CPU0. 1020 */ 1021 ASSERT_IN_NETISR(0); 1022 arp_update_oncpu(m, isaddr.s_addr, itaddr.s_addr == myaddr.s_addr, 1023 RTL_REPORTMSG, TRUE); 1024 1025 if (ncpus > 1) { 1026 struct netmsg_inarp *msg = &m->m_hdr.mh_arpmsg; 1027 1028 netmsg_init(&msg->base, NULL, &netisr_apanic_rport, 1029 0, arp_update_msghandler); 1030 msg->m = m; 1031 msg->saddr = isaddr.s_addr; 1032 msg->taddr = itaddr.s_addr; 1033 msg->myaddr = myaddr.s_addr; 1034 lwkt_sendmsg(netisr_cpuport(1), &msg->base.lmsg); 1035 } else { 1036 goto reply; 1037 } 1038 1039 /* 1040 * Just return here; after all CPUs's routing tables are 1041 * properly updated by this ARP packet, an ARP reply will 1042 * be generated if appropriate. 1043 */ 1044 return; 1045 reply: 1046 in_arpreply(m, itaddr.s_addr, myaddr.s_addr); 1047 } 1048 1049 static void 1050 arp_reply_msghandler(netmsg_t msg) 1051 { 1052 struct netmsg_inarp *rmsg = (struct netmsg_inarp *)msg; 1053 1054 in_arpreply(rmsg->m, rmsg->taddr, rmsg->myaddr); 1055 /* Don't reply this netmsg; netmsg_inarp is embedded in mbuf */ 1056 } 1057 1058 static void 1059 arp_update_msghandler(netmsg_t msg) 1060 { 1061 struct netmsg_inarp *rmsg = (struct netmsg_inarp *)msg; 1062 int nextcpu; 1063 1064 /* 1065 * This message handler will be called on all of the APs; 1066 * no need to generate rtmsg on them. 1067 */ 1068 KASSERT(mycpuid > 0, ("arp update msg on cpu%d", mycpuid)); 1069 arp_update_oncpu(rmsg->m, rmsg->saddr, rmsg->taddr == rmsg->myaddr, 1070 RTL_DONTREPORT, FALSE); 1071 1072 nextcpu = mycpuid + 1; 1073 if (nextcpu < ncpus) { 1074 lwkt_forwardmsg(netisr_cpuport(nextcpu), &rmsg->base.lmsg); 1075 } else { 1076 struct mbuf *m = rmsg->m; 1077 in_addr_t saddr = rmsg->saddr; 1078 in_addr_t taddr = rmsg->taddr; 1079 in_addr_t myaddr = rmsg->myaddr; 1080 1081 /* 1082 * Dispatch this mbuf to netisr0 to perform ARP reply, 1083 * if appropriate. 1084 * NOTE: netmsg_inarp is embedded in this mbuf. 1085 */ 1086 netmsg_init(&rmsg->base, NULL, &netisr_apanic_rport, 1087 0, arp_reply_msghandler); 1088 rmsg->m = m; 1089 rmsg->saddr = saddr; 1090 rmsg->taddr = taddr; 1091 rmsg->myaddr = myaddr; 1092 lwkt_sendmsg(netisr_cpuport(0), &rmsg->base.lmsg); 1093 } 1094 } 1095 1096 static void 1097 in_arpreply(struct mbuf *m, in_addr_t taddr, in_addr_t myaddr) 1098 { 1099 struct ifnet *ifp = m->m_pkthdr.rcvif; 1100 const uint8_t *enaddr; 1101 struct arphdr *ah; 1102 struct sockaddr sa; 1103 struct ether_header *eh; 1104 1105 ah = mtod(m, struct arphdr *); 1106 if (ntohs(ah->ar_op) != ARPOP_REQUEST) { 1107 m_freem(m); 1108 return; 1109 } 1110 1111 enaddr = (const uint8_t *)IF_LLADDR(ifp); 1112 if (taddr == myaddr) { 1113 /* I am the target */ 1114 memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); 1115 memcpy(ar_sha(ah), enaddr, ah->ar_hln); 1116 } else { 1117 struct llinfo_arp *la; 1118 struct rtentry *rt; 1119 1120 la = arplookup(taddr, FALSE, RTL_DONTREPORT, SIN_PROXY); 1121 if (la == NULL) { 1122 struct sockaddr_in sin; 1123 1124 if (!arp_proxyall) { 1125 m_freem(m); 1126 return; 1127 } 1128 1129 bzero(&sin, sizeof sin); 1130 sin.sin_family = AF_INET; 1131 sin.sin_len = sizeof sin; 1132 sin.sin_addr.s_addr = taddr; 1133 1134 rt = rtpurelookup((struct sockaddr *)&sin); 1135 if (rt == NULL) { 1136 m_freem(m); 1137 return; 1138 } 1139 --rt->rt_refcnt; 1140 /* 1141 * Don't send proxies for nodes on the same interface 1142 * as this one came out of, or we'll get into a fight 1143 * over who claims what Ether address. 1144 */ 1145 if (rt->rt_ifp == ifp) { 1146 m_freem(m); 1147 return; 1148 } 1149 memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); 1150 memcpy(ar_sha(ah), enaddr, ah->ar_hln); 1151 #ifdef DEBUG_PROXY 1152 kprintf("arp: proxying for %s\n", inet_ntoa(itaddr)); 1153 #endif 1154 } else { 1155 struct sockaddr_dl *sdl; 1156 1157 rt = la->la_rt; 1158 memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); 1159 sdl = SDL(rt->rt_gateway); 1160 memcpy(ar_sha(ah), LLADDR(sdl), ah->ar_hln); 1161 } 1162 } 1163 1164 memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); 1165 memcpy(ar_spa(ah), &taddr, ah->ar_pln); 1166 ah->ar_op = htons(ARPOP_REPLY); 1167 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 1168 switch (ifp->if_type) { 1169 case IFT_ETHER: 1170 /* 1171 * May not be correct for types not explictly 1172 * listed, but it is our best guess. 1173 */ 1174 default: 1175 eh = (struct ether_header *)sa.sa_data; 1176 memcpy(eh->ether_dhost, ar_tha(ah), sizeof eh->ether_dhost); 1177 eh->ether_type = htons(ETHERTYPE_ARP); 1178 break; 1179 } 1180 sa.sa_family = AF_UNSPEC; 1181 sa.sa_len = sizeof sa; 1182 ifp->if_output(ifp, m, &sa, NULL); 1183 } 1184 1185 #endif /* INET */ 1186 1187 /* 1188 * Free an arp entry. If the arp entry is actively referenced or represents 1189 * a static entry we only clear it back to an unresolved state, otherwise 1190 * we destroy the entry entirely. 1191 * 1192 * Note that static entries are created when route add ... -interface is used 1193 * to create an interface route to a (direct) destination. 1194 */ 1195 static void 1196 arptfree(struct llinfo_arp *la) 1197 { 1198 struct rtentry *rt = la->la_rt; 1199 struct sockaddr_dl *sdl; 1200 1201 if (rt == NULL) 1202 panic("arptfree"); 1203 sdl = SDL(rt->rt_gateway); 1204 if (sdl != NULL && 1205 ((rt->rt_refcnt > 0 && sdl->sdl_family == AF_LINK) || 1206 (rt->rt_flags & RTF_STATIC))) { 1207 sdl->sdl_alen = 0; 1208 la->la_preempt = la->la_asked = 0; 1209 rt->rt_flags &= ~RTF_REJECT; 1210 return; 1211 } 1212 rtrequest(RTM_DELETE, rt_key(rt), NULL, rt_mask(rt), 0, NULL); 1213 } 1214 1215 /* 1216 * Lookup or enter a new address in arptab. 1217 */ 1218 static struct llinfo_arp * 1219 arplookup(in_addr_t addr, boolean_t create, boolean_t generate_report, 1220 boolean_t proxy) 1221 { 1222 struct rtentry *rt; 1223 struct sockaddr_inarp sin = { sizeof sin, AF_INET }; 1224 const char *why = NULL; 1225 1226 sin.sin_addr.s_addr = addr; 1227 sin.sin_other = proxy ? SIN_PROXY : 0; 1228 if (create) { 1229 rt = _rtlookup((struct sockaddr *)&sin, 1230 generate_report, RTL_DOCLONE); 1231 } else { 1232 rt = rtpurelookup((struct sockaddr *)&sin); 1233 } 1234 if (rt == NULL) 1235 return (NULL); 1236 rt->rt_refcnt--; 1237 1238 if (rt->rt_flags & RTF_GATEWAY) 1239 why = "host is not on local network"; 1240 else if (!(rt->rt_flags & RTF_LLINFO)) 1241 why = "could not allocate llinfo"; 1242 else if (rt->rt_gateway->sa_family != AF_LINK) 1243 why = "gateway route is not ours"; 1244 1245 if (why) { 1246 if (create && log_arp_creation_failure) { 1247 log(LOG_DEBUG, "arplookup %s failed: %s\n", 1248 inet_ntoa(sin.sin_addr), why); 1249 } 1250 if (rt->rt_refcnt <= 0 && (rt->rt_flags & RTF_WASCLONED)) { 1251 /* No references to this route. Purge it. */ 1252 rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway, 1253 rt_mask(rt), rt->rt_flags, NULL); 1254 } 1255 return (NULL); 1256 } 1257 return (rt->rt_llinfo); 1258 } 1259 1260 void 1261 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1262 { 1263 ifa->ifa_rtrequest = arp_rtrequest; 1264 ifa->ifa_flags |= RTF_CLONING; 1265 } 1266 1267 void 1268 arp_gratuitous(struct ifnet *ifp, struct ifaddr *ifa) 1269 { 1270 if (IA_SIN(ifa)->sin_addr.s_addr != INADDR_ANY) { 1271 arprequest_async(ifp, &IA_SIN(ifa)->sin_addr, 1272 &IA_SIN(ifa)->sin_addr, NULL); 1273 } 1274 } 1275 1276 static void 1277 arp_ifaddr(void *arg __unused, struct ifnet *ifp, 1278 enum ifaddr_event event, struct ifaddr *ifa) 1279 { 1280 if (ifa->ifa_rtrequest != arp_rtrequest) /* XXX need a generic way */ 1281 return; 1282 if (ifa->ifa_addr->sa_family != AF_INET) 1283 return; 1284 if (event == IFADDR_EVENT_DELETE) 1285 return; 1286 1287 /* 1288 * - CARP interfaces will take care of gratuitous ARP themselves. 1289 * - If we are the CARP interface's parent, don't send gratuitous 1290 * ARP to avoid unnecessary confusion. 1291 */ 1292 #ifdef CARP 1293 if (ifp->if_type != IFT_CARP && ifp->if_carp == NULL) 1294 #endif 1295 { 1296 arp_gratuitous(ifp, ifa); 1297 } 1298 } 1299 1300 static void 1301 arp_init(void) 1302 { 1303 int cpu; 1304 1305 for (cpu = 0; cpu < ncpus2; cpu++) 1306 LIST_INIT(&llinfo_arp_list[cpu]); 1307 1308 netisr_register(NETISR_ARP, arpintr, NULL); 1309 1310 EVENTHANDLER_REGISTER(ifaddr_event, arp_ifaddr, NULL, 1311 EVENTHANDLER_PRI_LAST); 1312 } 1313 1314 SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0); 1315