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