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. All advertising materials mentioning features or use of this software 46 * must display the following acknowledgement: 47 * This product includes software developed by the University of 48 * California, Berkeley and its contributors. 49 * 4. Neither the name of the University nor the names of its contributors 50 * may be used to endorse or promote products derived from this software 51 * without specific prior written permission. 52 * 53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 63 * SUCH DAMAGE. 64 * 65 * @(#)if_ether.c 8.1 (Berkeley) 6/10/93 66 * $FreeBSD: src/sys/netinet/if_ether.c,v 1.64.2.23 2003/04/11 07:23:15 fjoe Exp $ 67 */ 68 69 /* 70 * Ethernet address resolution protocol. 71 * TODO: 72 * add "inuse/lock" bit (or ref. count) along with valid bit 73 */ 74 75 #include "opt_inet.h" 76 #include "opt_carp.h" 77 78 #include <sys/param.h> 79 #include <sys/kernel.h> 80 #include <sys/queue.h> 81 #include <sys/sysctl.h> 82 #include <sys/systm.h> 83 #include <sys/mbuf.h> 84 #include <sys/malloc.h> 85 #include <sys/socket.h> 86 #include <sys/syslog.h> 87 #include <sys/lock.h> 88 89 #include <net/if.h> 90 #include <net/if_dl.h> 91 #include <net/if_types.h> 92 #include <net/route.h> 93 #include <net/netisr.h> 94 #include <net/if_llc.h> 95 96 #include <netinet/in.h> 97 #include <netinet/in_var.h> 98 #include <netinet/if_ether.h> 99 100 #include <sys/thread2.h> 101 #include <sys/msgport2.h> 102 #include <net/netmsg2.h> 103 #include <net/netisr2.h> 104 #include <sys/mplock2.h> 105 106 #ifdef CARP 107 #include <netinet/ip_carp.h> 108 #endif 109 110 #define SIN(s) ((struct sockaddr_in *)s) 111 #define SDL(s) ((struct sockaddr_dl *)s) 112 113 SYSCTL_DECL(_net_link_ether); 114 SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, ""); 115 116 /* timer values */ 117 static int arpt_prune = (5*60*1); /* walk list every 5 minutes */ 118 static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */ 119 static int arpt_down = 20; /* once declared down, don't send for 20 sec */ 120 121 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, prune_intvl, CTLFLAG_RW, 122 &arpt_prune, 0, ""); 123 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW, 124 &arpt_keep, 0, ""); 125 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, host_down_time, CTLFLAG_RW, 126 &arpt_down, 0, ""); 127 128 #define rt_expire rt_rmx.rmx_expire 129 130 struct llinfo_arp { 131 LIST_ENTRY(llinfo_arp) la_le; 132 struct rtentry *la_rt; 133 struct mbuf *la_hold; /* last packet until resolved/timeout */ 134 struct lwkt_port *la_msgport; /* last packet's msgport */ 135 u_short la_preempt; /* countdown for pre-expiry arps */ 136 u_short la_asked; /* #times we QUERIED following expiration */ 137 }; 138 139 static LIST_HEAD(, llinfo_arp) llinfo_arp_list[MAXCPU]; 140 141 static int arp_maxtries = 5; 142 static int useloopback = 1; /* use loopback interface for local traffic */ 143 static int arp_proxyall = 0; 144 static int arp_refresh = 60; /* refresh arp cache ~60 (not impl yet) */ 145 static int arp_restricted_match = 0; 146 147 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW, 148 &arp_maxtries, 0, "ARP resolution attempts before returning error"); 149 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW, 150 &useloopback, 0, "Use the loopback interface for local traffic"); 151 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW, 152 &arp_proxyall, 0, "Enable proxy ARP for all suitable requests"); 153 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, restricted_match, CTLFLAG_RW, 154 &arp_restricted_match, 0, "Only match against the sender"); 155 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, refresh, CTLFLAG_RW, 156 &arp_refresh, 0, "Preemptively refresh the ARP"); 157 158 static void arp_rtrequest(int, struct rtentry *, struct rt_addrinfo *); 159 static void arprequest(struct ifnet *, const struct in_addr *, 160 const struct in_addr *, const u_char *); 161 static void arprequest_async(struct ifnet *, const struct in_addr *, 162 const struct in_addr *, const u_char *); 163 static void arpintr(netmsg_t msg); 164 static void arptfree(struct llinfo_arp *); 165 static void arptimer(void *); 166 static struct llinfo_arp * 167 arplookup(in_addr_t, boolean_t, boolean_t, boolean_t); 168 #ifdef INET 169 static void in_arpinput(struct mbuf *); 170 static void in_arpreply(struct mbuf *m, in_addr_t, in_addr_t); 171 static void arp_update_msghandler(netmsg_t); 172 static void arp_reply_msghandler(netmsg_t); 173 #endif 174 175 static struct callout arptimer_ch[MAXCPU]; 176 177 /* 178 * Timeout routine. Age arp_tab entries periodically. 179 */ 180 /* ARGSUSED */ 181 static void 182 arptimer(void *ignored_arg) 183 { 184 struct llinfo_arp *la, *nla; 185 186 crit_enter(); 187 LIST_FOREACH_MUTABLE(la, &llinfo_arp_list[mycpuid], la_le, nla) { 188 if (la->la_rt->rt_expire && la->la_rt->rt_expire <= time_second) 189 arptfree(la); 190 } 191 callout_reset(&arptimer_ch[mycpuid], arpt_prune * hz, arptimer, NULL); 192 crit_exit(); 193 } 194 195 /* 196 * Parallel to llc_rtrequest. 197 * 198 * Called after a route is successfully added to the tree to fix-up the 199 * route and initiate arp operations if required. 200 */ 201 static void 202 arp_rtrequest(int req, struct rtentry *rt, struct rt_addrinfo *info) 203 { 204 struct sockaddr *gate = rt->rt_gateway; 205 struct llinfo_arp *la = rt->rt_llinfo; 206 207 struct sockaddr_dl null_sdl = { sizeof null_sdl, AF_LINK }; 208 static boolean_t arpinit_done[MAXCPU]; 209 210 if (!arpinit_done[mycpuid]) { 211 arpinit_done[mycpuid] = TRUE; 212 callout_init(&arptimer_ch[mycpuid]); 213 callout_reset(&arptimer_ch[mycpuid], hz, arptimer, NULL); 214 } 215 if (rt->rt_flags & RTF_GATEWAY) 216 return; 217 218 switch (req) { 219 case RTM_ADD: 220 /* 221 * XXX: If this is a manually added route to interface 222 * such as older version of routed or gated might provide, 223 * restore cloning bit. 224 */ 225 if (!(rt->rt_flags & RTF_HOST) && 226 SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff) 227 rt->rt_flags |= RTF_CLONING; 228 if (rt->rt_flags & RTF_CLONING) { 229 /* 230 * Case 1: This route should come from a route to iface. 231 */ 232 rt_setgate(rt, rt_key(rt), 233 (struct sockaddr *)&null_sdl, 234 RTL_DONTREPORT); 235 gate = rt->rt_gateway; 236 SDL(gate)->sdl_type = rt->rt_ifp->if_type; 237 SDL(gate)->sdl_index = rt->rt_ifp->if_index; 238 rt->rt_expire = time_second; 239 break; 240 } 241 /* Announce a new entry if requested. */ 242 if (rt->rt_flags & RTF_ANNOUNCE) { 243 arprequest_async(rt->rt_ifp, 244 &SIN(rt_key(rt))->sin_addr, 245 &SIN(rt_key(rt))->sin_addr, 246 LLADDR(SDL(gate))); 247 } 248 /*FALLTHROUGH*/ 249 case RTM_RESOLVE: 250 if (gate->sa_family != AF_LINK || 251 gate->sa_len < sizeof(struct sockaddr_dl)) { 252 log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n"); 253 break; 254 } 255 SDL(gate)->sdl_type = rt->rt_ifp->if_type; 256 SDL(gate)->sdl_index = rt->rt_ifp->if_index; 257 if (la != NULL) 258 break; /* This happens on a route change */ 259 /* 260 * Case 2: This route may come from cloning, or a manual route 261 * add with a LL address. 262 */ 263 R_Malloc(la, struct llinfo_arp *, sizeof *la); 264 rt->rt_llinfo = la; 265 if (la == NULL) { 266 log(LOG_DEBUG, "arp_rtrequest: malloc failed\n"); 267 break; 268 } 269 bzero(la, sizeof *la); 270 la->la_rt = rt; 271 rt->rt_flags |= RTF_LLINFO; 272 LIST_INSERT_HEAD(&llinfo_arp_list[mycpuid], la, la_le); 273 274 #ifdef INET 275 /* 276 * This keeps the multicast addresses from showing up 277 * in `arp -a' listings as unresolved. It's not actually 278 * functional. Then the same for broadcast. 279 */ 280 if (IN_MULTICAST(ntohl(SIN(rt_key(rt))->sin_addr.s_addr))) { 281 ETHER_MAP_IP_MULTICAST(&SIN(rt_key(rt))->sin_addr, 282 LLADDR(SDL(gate))); 283 SDL(gate)->sdl_alen = 6; 284 rt->rt_expire = 0; 285 } 286 if (in_broadcast(SIN(rt_key(rt))->sin_addr, rt->rt_ifp)) { 287 memcpy(LLADDR(SDL(gate)), rt->rt_ifp->if_broadcastaddr, 288 rt->rt_ifp->if_addrlen); 289 SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen; 290 rt->rt_expire = 0; 291 } 292 #endif 293 294 /* 295 * This fixes up the routing interface for local addresses. 296 * The route is adjusted to point at lo0 and the expiration 297 * timer is disabled. 298 * 299 * NOTE: This prevents locally targetted traffic from going 300 * out the hardware interface, which is inefficient 301 * and might not work if the hardware cannot listen 302 * to its own transmitted packets. Setting 303 * net.link.ether.inet.useloopback to 0 will force 304 * packets for local addresses out the hardware (and 305 * it is expected to receive its own packet). 306 * 307 * XXX We should just be able to test RTF_LOCAL here instead 308 * of having to compare IPs. 309 */ 310 if (SIN(rt_key(rt))->sin_addr.s_addr == 311 (IA_SIN(rt->rt_ifa))->sin_addr.s_addr) { 312 rt->rt_expire = 0; 313 bcopy(IF_LLADDR(rt->rt_ifp), LLADDR(SDL(gate)), 314 SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen); 315 if (useloopback) 316 rt->rt_ifp = loif; 317 } 318 break; 319 320 case RTM_DELETE: 321 if (la == NULL) 322 break; 323 LIST_REMOVE(la, la_le); 324 rt->rt_llinfo = NULL; 325 rt->rt_flags &= ~RTF_LLINFO; 326 if (la->la_hold != NULL) 327 m_freem(la->la_hold); 328 Free(la); 329 break; 330 } 331 } 332 333 static struct mbuf * 334 arpreq_alloc(struct ifnet *ifp, const struct in_addr *sip, 335 const struct in_addr *tip, const u_char *enaddr) 336 { 337 struct mbuf *m; 338 struct arphdr *ah; 339 u_short ar_hrd; 340 341 if ((m = m_gethdr(MB_DONTWAIT, MT_DATA)) == NULL) 342 return NULL; 343 m->m_pkthdr.rcvif = NULL; 344 345 switch (ifp->if_type) { 346 case IFT_ETHER: 347 /* 348 * This may not be correct for types not explicitly 349 * listed, but this is our best guess 350 */ 351 default: 352 ar_hrd = htons(ARPHRD_ETHER); 353 354 m->m_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr)); 355 m->m_pkthdr.len = m->m_len; 356 MH_ALIGN(m, m->m_len); 357 358 ah = mtod(m, struct arphdr *); 359 break; 360 } 361 362 ah->ar_hrd = ar_hrd; 363 ah->ar_pro = htons(ETHERTYPE_IP); 364 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 365 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 366 ah->ar_op = htons(ARPOP_REQUEST); 367 memcpy(ar_sha(ah), enaddr, ah->ar_hln); 368 memset(ar_tha(ah), 0, ah->ar_hln); 369 memcpy(ar_spa(ah), sip, ah->ar_pln); 370 memcpy(ar_tpa(ah), tip, ah->ar_pln); 371 372 return m; 373 } 374 375 static void 376 arpreq_send(struct ifnet *ifp, struct mbuf *m) 377 { 378 struct sockaddr sa; 379 struct ether_header *eh; 380 381 switch (ifp->if_type) { 382 case IFT_ETHER: 383 /* 384 * This may not be correct for types not explicitly 385 * listed, but this is our best guess 386 */ 387 default: 388 eh = (struct ether_header *)sa.sa_data; 389 /* if_output() will not swap */ 390 eh->ether_type = htons(ETHERTYPE_ARP); 391 memcpy(eh->ether_dhost, ifp->if_broadcastaddr, ifp->if_addrlen); 392 break; 393 } 394 395 sa.sa_family = AF_UNSPEC; 396 sa.sa_len = sizeof(sa); 397 ifp->if_output(ifp, m, &sa, NULL); 398 } 399 400 static void 401 arpreq_send_handler(netmsg_t msg) 402 { 403 struct mbuf *m = msg->packet.nm_packet; 404 struct ifnet *ifp = msg->lmsg.u.ms_resultp; 405 406 arpreq_send(ifp, m); 407 /* nmsg was embedded in the mbuf, do not reply! */ 408 } 409 410 /* 411 * Broadcast an ARP request. Caller specifies: 412 * - arp header source ip address 413 * - arp header target ip address 414 * - arp header source ethernet address 415 * 416 * NOTE: Caller MUST NOT hold ifp's serializer 417 */ 418 static void 419 arprequest(struct ifnet *ifp, const struct in_addr *sip, 420 const struct in_addr *tip, const u_char *enaddr) 421 { 422 struct mbuf *m; 423 424 if (enaddr == NULL) { 425 if (ifp->if_bridge) { 426 enaddr = IF_LLADDR(ether_bridge_interface(ifp)); 427 } else { 428 enaddr = IF_LLADDR(ifp); 429 } 430 } 431 432 m = arpreq_alloc(ifp, sip, tip, enaddr); 433 if (m == NULL) 434 return; 435 arpreq_send(ifp, m); 436 } 437 438 /* 439 * Same as arprequest(), except: 440 * - Caller is allowed to hold ifp's serializer 441 * - Network output is done in protocol thead 442 */ 443 static void 444 arprequest_async(struct ifnet *ifp, const struct in_addr *sip, 445 const struct in_addr *tip, const u_char *enaddr) 446 { 447 struct mbuf *m; 448 struct netmsg_packet *pmsg; 449 450 if (enaddr == NULL) { 451 if (ifp->if_bridge) { 452 enaddr = IF_LLADDR(ether_bridge_interface(ifp)); 453 } else { 454 enaddr = IF_LLADDR(ifp); 455 } 456 } 457 m = arpreq_alloc(ifp, sip, tip, enaddr); 458 if (m == NULL) 459 return; 460 461 pmsg = &m->m_hdr.mh_netmsg; 462 netmsg_init(&pmsg->base, NULL, &netisr_apanic_rport, 463 0, arpreq_send_handler); 464 pmsg->nm_packet = m; 465 pmsg->base.lmsg.u.ms_resultp = ifp; 466 467 lwkt_sendmsg(netisr_cpuport(mycpuid), &pmsg->base.lmsg); 468 } 469 470 /* 471 * Resolve an IP address into an ethernet address. If success, 472 * desten is filled in. If there is no entry in arptab, 473 * set one up and broadcast a request for the IP address. 474 * Hold onto this mbuf and resend it once the address 475 * is finally resolved. A return value of 1 indicates 476 * that desten has been filled in and the packet should be sent 477 * normally; a 0 return indicates that the packet has been 478 * taken over here, either now or for later transmission. 479 */ 480 int 481 arpresolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m, 482 struct sockaddr *dst, u_char *desten) 483 { 484 struct rtentry *rt = NULL; 485 struct llinfo_arp *la = NULL; 486 struct sockaddr_dl *sdl; 487 488 if (m->m_flags & M_BCAST) { /* broadcast */ 489 memcpy(desten, ifp->if_broadcastaddr, ifp->if_addrlen); 490 return (1); 491 } 492 if (m->m_flags & M_MCAST) {/* multicast */ 493 ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten); 494 return (1); 495 } 496 if (rt0 != NULL) { 497 if (rt_llroute(dst, rt0, &rt) != 0) { 498 m_freem(m); 499 return 0; 500 } 501 la = rt->rt_llinfo; 502 } 503 if (la == NULL) { 504 la = arplookup(SIN(dst)->sin_addr.s_addr, 505 TRUE, RTL_REPORTMSG, FALSE); 506 if (la != NULL) 507 rt = la->la_rt; 508 } 509 if (la == NULL || rt == NULL) { 510 log(LOG_DEBUG, "arpresolve: can't allocate llinfo for %s%s%s\n", 511 inet_ntoa(SIN(dst)->sin_addr), la ? "la" : " ", 512 rt ? "rt" : ""); 513 m_freem(m); 514 return (0); 515 } 516 sdl = SDL(rt->rt_gateway); 517 /* 518 * Check the address family and length is valid, the address 519 * is resolved; otherwise, try to resolve. 520 */ 521 if ((rt->rt_expire == 0 || rt->rt_expire > time_second) && 522 sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) { 523 /* 524 * If entry has an expiry time and it is approaching, 525 * see if we need to send an ARP request within this 526 * arpt_down interval. 527 */ 528 if ((rt->rt_expire != 0) && 529 (time_second + la->la_preempt > rt->rt_expire)) { 530 arprequest(ifp, 531 &SIN(rt->rt_ifa->ifa_addr)->sin_addr, 532 &SIN(dst)->sin_addr, 533 NULL); 534 la->la_preempt--; 535 } 536 537 bcopy(LLADDR(sdl), desten, sdl->sdl_alen); 538 return 1; 539 } 540 /* 541 * If ARP is disabled or static on this interface, stop. 542 * XXX 543 * Probably should not allocate empty llinfo struct if we are 544 * not going to be sending out an arp request. 545 */ 546 if (ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) { 547 m_freem(m); 548 return (0); 549 } 550 /* 551 * There is an arptab entry, but no ethernet address 552 * response yet. Replace the held mbuf with this 553 * latest one. 554 */ 555 if (la->la_hold != NULL) 556 m_freem(la->la_hold); 557 la->la_hold = m; 558 la->la_msgport = netisr_curport(); 559 if (rt->rt_expire || ((rt->rt_flags & RTF_STATIC) && !sdl->sdl_alen)) { 560 rt->rt_flags &= ~RTF_REJECT; 561 if (la->la_asked == 0 || rt->rt_expire != time_second) { 562 rt->rt_expire = time_second; 563 if (la->la_asked++ < arp_maxtries) { 564 arprequest(ifp, 565 &SIN(rt->rt_ifa->ifa_addr)->sin_addr, 566 &SIN(dst)->sin_addr, 567 NULL); 568 } else { 569 rt->rt_flags |= RTF_REJECT; 570 rt->rt_expire += arpt_down; 571 la->la_asked = 0; 572 la->la_preempt = arp_maxtries; 573 } 574 } 575 } 576 return (0); 577 } 578 579 /* 580 * Common length and type checks are done here, 581 * then the protocol-specific routine is called. 582 */ 583 static void 584 arpintr(netmsg_t msg) 585 { 586 struct mbuf *m = msg->packet.nm_packet; 587 struct arphdr *ar; 588 u_short ar_hrd; 589 char hexstr[6]; 590 591 if (m->m_len < sizeof(struct arphdr) && 592 (m = m_pullup(m, sizeof(struct arphdr))) == NULL) { 593 log(LOG_ERR, "arp: runt packet -- m_pullup failed\n"); 594 return; 595 } 596 ar = mtod(m, struct arphdr *); 597 598 ar_hrd = ntohs(ar->ar_hrd); 599 if (ar_hrd != ARPHRD_ETHER && ar_hrd != ARPHRD_IEEE802) { 600 hexncpy((unsigned char *)&ar->ar_hrd, 2, hexstr, 5, NULL); 601 log(LOG_ERR, "arp: unknown hardware address format (0x%s)\n", 602 hexstr); 603 m_freem(m); 604 return; 605 } 606 607 if (m->m_pkthdr.len < arphdr_len(ar)) { 608 if ((m = m_pullup(m, arphdr_len(ar))) == NULL) { 609 log(LOG_ERR, "arp: runt packet\n"); 610 return; 611 } 612 ar = mtod(m, struct arphdr *); 613 } 614 615 switch (ntohs(ar->ar_pro)) { 616 #ifdef INET 617 case ETHERTYPE_IP: 618 in_arpinput(m); 619 return; 620 #endif 621 } 622 m_freem(m); 623 /* msg was embedded in the mbuf, do not reply! */ 624 } 625 626 #ifdef INET 627 /* 628 * ARP for Internet protocols on 10 Mb/s Ethernet. 629 * Algorithm is that given in RFC 826. 630 * In addition, a sanity check is performed on the sender 631 * protocol address, to catch impersonators. 632 * We no longer handle negotiations for use of trailer protocol: 633 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent 634 * along with IP replies if we wanted trailers sent to us, 635 * and also sent them in response to IP replies. 636 * This allowed either end to announce the desire to receive 637 * trailer packets. 638 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, 639 * but formerly didn't normally send requests. 640 */ 641 642 static int log_arp_wrong_iface = 1; 643 static int log_arp_movements = 1; 644 static int log_arp_permanent_modify = 1; 645 646 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW, 647 &log_arp_wrong_iface, 0, 648 "Log arp packets arriving on the wrong interface"); 649 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_movements, CTLFLAG_RW, 650 &log_arp_movements, 0, 651 "Log arp replies from MACs different than the one in the cache"); 652 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_permanent_modify, CTLFLAG_RW, 653 &log_arp_permanent_modify, 0, 654 "Log arp replies from MACs different than the one " 655 "in the permanent arp entry"); 656 657 658 static void 659 arp_hold_output(netmsg_t msg) 660 { 661 struct mbuf *m = msg->packet.nm_packet; 662 struct rtentry *rt; 663 struct ifnet *ifp; 664 665 rt = msg->lmsg.u.ms_resultp; 666 ifp = m->m_pkthdr.rcvif; 667 m->m_pkthdr.rcvif = NULL; 668 669 ifp->if_output(ifp, m, rt_key(rt), rt); 670 671 /* Drop the reference count bumped by the sender */ 672 RTFREE(rt); 673 674 /* nmsg was embedded in the mbuf, do not reply! */ 675 } 676 677 static void 678 arp_update_oncpu(struct mbuf *m, in_addr_t saddr, boolean_t create, 679 boolean_t generate_report, boolean_t dologging) 680 { 681 struct arphdr *ah = mtod(m, struct arphdr *); 682 struct ifnet *ifp = m->m_pkthdr.rcvif; 683 struct llinfo_arp *la; 684 struct sockaddr_dl *sdl; 685 struct rtentry *rt; 686 char hexstr[2][64]; 687 688 la = arplookup(saddr, create, generate_report, FALSE); 689 if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) { 690 struct in_addr isaddr = { saddr }; 691 692 /* 693 * Normally arps coming in on the wrong interface are ignored, 694 * but if we are bridging and the two interfaces belong to 695 * the same bridge, or one is a member of the bridge which 696 * is the other, then it isn't an error. 697 */ 698 if (rt->rt_ifp != ifp) { 699 /* 700 * (1) ifp and rt_ifp both members of same bridge 701 * (2) rt_ifp member of bridge ifp 702 * (3) ifp member of bridge rt_ifp 703 * 704 * Always replace rt_ifp with the bridge ifc. 705 */ 706 struct ifnet *nifp; 707 708 if (ifp->if_bridge && 709 rt->rt_ifp->if_bridge == ifp->if_bridge) { 710 nifp = ether_bridge_interface(ifp); 711 } else if (rt->rt_ifp->if_bridge && 712 ether_bridge_interface(rt->rt_ifp) == ifp) { 713 nifp = ifp; 714 } else if (ifp->if_bridge && 715 ether_bridge_interface(ifp) == rt->rt_ifp) { 716 nifp = rt->rt_ifp; 717 } else { 718 nifp = NULL; 719 } 720 721 if ((log_arp_wrong_iface == 1 && nifp == NULL) || 722 log_arp_wrong_iface == 2) { 723 hexncpy((u_char *)ar_sha(ah), ifp->if_addrlen, 724 hexstr[0], HEX_NCPYLEN(ifp->if_addrlen), ":"); 725 log(LOG_ERR, 726 "arp: %s is on %s " 727 "but got reply from %s on %s\n", 728 inet_ntoa(isaddr), 729 rt->rt_ifp->if_xname, hexstr[0], 730 ifp->if_xname); 731 } 732 if (nifp == NULL) 733 return; 734 735 /* 736 * nifp is our man! Replace rt_ifp and adjust 737 * the sdl. 738 */ 739 ifp = rt->rt_ifp = nifp; 740 sdl->sdl_type = ifp->if_type; 741 sdl->sdl_index = ifp->if_index; 742 } 743 if (sdl->sdl_alen && 744 bcmp(ar_sha(ah), LLADDR(sdl), sdl->sdl_alen)) { 745 if (rt->rt_expire != 0) { 746 if (dologging && log_arp_movements) { 747 hexncpy((u_char *)LLADDR(sdl), ifp->if_addrlen, 748 hexstr[0], HEX_NCPYLEN(ifp->if_addrlen), ":"); 749 hexncpy((u_char *)ar_sha(ah), ifp->if_addrlen, 750 hexstr[1], HEX_NCPYLEN(ifp->if_addrlen), ":"); 751 log(LOG_INFO, 752 "arp: %s moved from %s to %s on %s\n", 753 inet_ntoa(isaddr), hexstr[0], hexstr[1], 754 ifp->if_xname); 755 } 756 } else { 757 if (dologging && log_arp_permanent_modify) { 758 hexncpy((u_char *)ar_sha(ah), ifp->if_addrlen, 759 hexstr[0], HEX_NCPYLEN(ifp->if_addrlen), ":"); 760 log(LOG_ERR, 761 "arp: %s attempts to modify " 762 "permanent entry for %s on %s\n", 763 hexstr[0], inet_ntoa(isaddr), ifp->if_xname); 764 } 765 return; 766 } 767 } 768 /* 769 * sanity check for the address length. 770 * XXX this does not work for protocols with variable address 771 * length. -is 772 */ 773 if (dologging && sdl->sdl_alen && sdl->sdl_alen != ah->ar_hln) { 774 hexncpy((u_char *)ar_sha(ah), ifp->if_addrlen, 775 hexstr[0], HEX_NCPYLEN(ifp->if_addrlen), ":"); 776 log(LOG_WARNING, 777 "arp from %s: new addr len %d, was %d", 778 hexstr[0], ah->ar_hln, sdl->sdl_alen); 779 } 780 if (ifp->if_addrlen != ah->ar_hln) { 781 if (dologging) { 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: addr len: new %d, i/f %d " 786 "(ignored)", hexstr[0], 787 ah->ar_hln, ifp->if_addrlen); 788 } 789 return; 790 } 791 memcpy(LLADDR(sdl), ar_sha(ah), sdl->sdl_alen = ah->ar_hln); 792 if (rt->rt_expire != 0) { 793 rt->rt_expire = time_second + arpt_keep; 794 } 795 rt->rt_flags &= ~RTF_REJECT; 796 la->la_asked = 0; 797 la->la_preempt = arp_maxtries; 798 799 /* 800 * This particular cpu might have been holding an mbuf 801 * pending ARP resolution. If so, transmit the mbuf now. 802 */ 803 if (la->la_hold != NULL) { 804 struct mbuf *m = la->la_hold; 805 struct lwkt_port *port = la->la_msgport; 806 struct netmsg_packet *pmsg; 807 808 la->la_hold = NULL; 809 la->la_msgport = NULL; 810 811 m_adj(m, sizeof(struct ether_header)); 812 813 /* 814 * Make sure that this rtentry will not be freed 815 * before the packet is processed on the target 816 * msgport. The reference count will be dropped 817 * in the handler associated with this packet. 818 */ 819 rt->rt_refcnt++; 820 821 pmsg = &m->m_hdr.mh_netmsg; 822 netmsg_init(&pmsg->base, NULL, 823 &netisr_apanic_rport, 824 MSGF_PRIORITY, arp_hold_output); 825 pmsg->nm_packet = m; 826 827 /* Record necessary information */ 828 m->m_pkthdr.rcvif = ifp; 829 pmsg->base.lmsg.u.ms_resultp = rt; 830 831 lwkt_sendmsg(port, &pmsg->base.lmsg); 832 } 833 } 834 } 835 836 /* 837 * Called from arpintr() - this routine is run from a single cpu. 838 */ 839 static void 840 in_arpinput(struct mbuf *m) 841 { 842 struct arphdr *ah; 843 struct ifnet *ifp = m->m_pkthdr.rcvif; 844 struct ifaddr_container *ifac; 845 struct in_ifaddr_container *iac; 846 struct in_ifaddr *ia = NULL; 847 struct in_addr isaddr, itaddr, myaddr; 848 struct netmsg_inarp *msg; 849 uint8_t *enaddr = NULL; 850 int req_len; 851 char hexstr[64]; 852 853 req_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr)); 854 if (m->m_len < req_len && (m = m_pullup(m, req_len)) == NULL) { 855 log(LOG_ERR, "in_arp: runt packet -- m_pullup failed\n"); 856 return; 857 } 858 859 ah = mtod(m, struct arphdr *); 860 memcpy(&isaddr, ar_spa(ah), sizeof isaddr); 861 memcpy(&itaddr, ar_tpa(ah), sizeof itaddr); 862 863 /* 864 * Check both target and sender IP addresses: 865 * 866 * If we receive the packet on the interface owning the address, 867 * then accept the address. 868 * 869 * For a bridge, we accept the address if the receive interface and 870 * the interface owning the address are on the same bridge, and 871 * use the bridge MAC as the is-at response. The bridge will be 872 * responsible for handling the packet. 873 * 874 * (0) Check target IP against CARP IPs 875 */ 876 #ifdef CARP 877 LIST_FOREACH(iac, INADDR_HASH(itaddr.s_addr), ia_hash) { 878 int is_match = 0, is_parent = 0; 879 880 ia = iac->ia; 881 882 /* Skip all ia's which don't match */ 883 if (itaddr.s_addr != ia->ia_addr.sin_addr.s_addr) 884 continue; 885 886 if (ia->ia_ifp->if_type != IFT_CARP) 887 continue; 888 889 if (carp_parent(ia->ia_ifp) == ifp) 890 is_parent = 1; 891 if (is_parent || ia->ia_ifp == ifp) 892 is_match = carp_iamatch(ia); 893 894 if (is_match) { 895 if (is_parent) { 896 /* 897 * The parent interface will also receive 898 * the ethernet broadcast packets, e.g. ARP 899 * REQUEST, so if we could find a CARP 900 * interface of the parent that could match 901 * the target IP address, we then drop the 902 * packets, which is delieverd to us through 903 * the parent interface. 904 */ 905 m_freem(m); 906 return; 907 } 908 goto match; 909 } 910 } 911 #endif /* CARP */ 912 913 /* 914 * (1) Check target IP against our local IPs 915 */ 916 LIST_FOREACH(iac, INADDR_HASH(itaddr.s_addr), ia_hash) { 917 ia = iac->ia; 918 919 /* Skip all ia's which don't match */ 920 if (itaddr.s_addr != ia->ia_addr.sin_addr.s_addr) 921 continue; 922 923 #ifdef CARP 924 /* CARP interfaces are checked in (0) */ 925 if (ia->ia_ifp->if_type == IFT_CARP) 926 continue; 927 #endif 928 929 if (ifp->if_bridge && ia->ia_ifp && 930 ifp->if_bridge == ia->ia_ifp->if_bridge) { 931 ifp = ether_bridge_interface(ifp); 932 goto match; 933 } 934 if (ia->ia_ifp && ia->ia_ifp->if_bridge && 935 ether_bridge_interface(ia->ia_ifp) == ifp) { 936 goto match; 937 } 938 if (ifp->if_bridge && ether_bridge_interface(ifp) == 939 ia->ia_ifp) { 940 goto match; 941 } 942 if (ia->ia_ifp == ifp) { 943 goto match; 944 } 945 } 946 947 /* 948 * (2) Check sender IP against our local IPs 949 */ 950 LIST_FOREACH(iac, INADDR_HASH(isaddr.s_addr), ia_hash) { 951 ia = iac->ia; 952 953 /* Skip all ia's which don't match */ 954 if (isaddr.s_addr != ia->ia_addr.sin_addr.s_addr) 955 continue; 956 957 if (ifp->if_bridge && ia->ia_ifp && 958 ifp->if_bridge == ia->ia_ifp->if_bridge) { 959 ifp = ether_bridge_interface(ifp); 960 goto match; 961 } 962 if (ia->ia_ifp && ia->ia_ifp->if_bridge && 963 ether_bridge_interface(ia->ia_ifp) == ifp) { 964 goto match; 965 } 966 if (ifp->if_bridge && ether_bridge_interface(ifp) == 967 ia->ia_ifp) { 968 goto match; 969 } 970 971 if (ia->ia_ifp == ifp) 972 goto match; 973 } 974 975 /* 976 * No match, use the first inet address on the receive interface 977 * as a dummy address for the rest of the function. 978 */ 979 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) { 980 struct ifaddr *ifa = ifac->ifa; 981 982 if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET) { 983 ia = ifatoia(ifa); 984 goto match; 985 } 986 } 987 988 /* 989 * If we got here, we didn't find any suitable interface, 990 * so drop the packet. 991 */ 992 m_freem(m); 993 return; 994 995 match: 996 if (!enaddr) 997 enaddr = (uint8_t *)IF_LLADDR(ifp); 998 myaddr = ia->ia_addr.sin_addr; 999 if (!bcmp(ar_sha(ah), enaddr, ifp->if_addrlen)) { 1000 m_freem(m); /* it's from me, ignore it. */ 1001 return; 1002 } 1003 if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 1004 log(LOG_ERR, 1005 "arp: link address is broadcast for IP address %s!\n", 1006 inet_ntoa(isaddr)); 1007 m_freem(m); 1008 return; 1009 } 1010 if (isaddr.s_addr == myaddr.s_addr && myaddr.s_addr != 0) { 1011 hexncpy((u_char *)ar_sha(ah), ifp->if_addrlen, 1012 hexstr, HEX_NCPYLEN(ifp->if_addrlen), ":"); 1013 log(LOG_ERR, 1014 "arp: %s is using my IP address %s!\n", 1015 hexstr, inet_ntoa(isaddr)); 1016 itaddr = myaddr; 1017 goto reply; 1018 } 1019 if (ifp->if_flags & IFF_STATICARP) 1020 goto reply; 1021 1022 /* 1023 * When arp_restricted_match is true and the ARP response is not 1024 * specifically targetted to me, ignore it. Otherwise the entry 1025 * timeout may be updated for an old MAC. 1026 */ 1027 if (arp_restricted_match && itaddr.s_addr != myaddr.s_addr) { 1028 m_freem(m); 1029 return; 1030 } 1031 1032 /* 1033 * Update all CPU's routing tables with this ARP packet 1034 */ 1035 msg = &m->m_hdr.mh_arpmsg; 1036 netmsg_init(&msg->base, NULL, &netisr_apanic_rport, 1037 0, arp_update_msghandler); 1038 msg->m = m; 1039 msg->saddr = isaddr.s_addr; 1040 msg->taddr = itaddr.s_addr; 1041 msg->myaddr = myaddr.s_addr; 1042 lwkt_sendmsg(rtable_portfn(0), &msg->base.lmsg); 1043 1044 /* 1045 * Just return here; after all CPUs's routing tables are 1046 * properly updated by this ARP packet, an ARP reply will 1047 * be generated if appropriate. 1048 */ 1049 return; 1050 reply: 1051 in_arpreply(m, itaddr.s_addr, myaddr.s_addr); 1052 } 1053 1054 static void 1055 arp_reply_msghandler(netmsg_t msg) 1056 { 1057 struct netmsg_inarp *rmsg = (struct netmsg_inarp *)msg; 1058 1059 in_arpreply(rmsg->m, rmsg->taddr, rmsg->myaddr); 1060 /* Don't reply this netmsg; netmsg_inarp is embedded in mbuf */ 1061 } 1062 1063 static void 1064 arp_update_msghandler(netmsg_t msg) 1065 { 1066 struct netmsg_inarp *rmsg = (struct netmsg_inarp *)msg; 1067 int nextcpu; 1068 1069 /* 1070 * This message handler will be called on all of the CPUs, 1071 * however, we only need to generate rtmsg on CPU0. 1072 */ 1073 arp_update_oncpu(rmsg->m, rmsg->saddr, rmsg->taddr == rmsg->myaddr, 1074 mycpuid == 0 ? RTL_REPORTMSG : RTL_DONTREPORT, mycpuid == 0); 1075 1076 nextcpu = mycpuid + 1; 1077 if (nextcpu < ncpus) { 1078 lwkt_forwardmsg(rtable_portfn(nextcpu), &rmsg->base.lmsg); 1079 } else { 1080 struct mbuf *m = rmsg->m; 1081 in_addr_t saddr = rmsg->saddr; 1082 in_addr_t taddr = rmsg->taddr; 1083 in_addr_t myaddr = rmsg->myaddr; 1084 1085 /* 1086 * Dispatch this mbuf to netisr0 to perform ARP reply, 1087 * if appropriate. 1088 * NOTE: netmsg_inarp is embedded in this mbuf. 1089 */ 1090 netmsg_init(&rmsg->base, NULL, &netisr_apanic_rport, 1091 0, arp_reply_msghandler); 1092 rmsg->m = m; 1093 rmsg->saddr = saddr; 1094 rmsg->taddr = taddr; 1095 rmsg->myaddr = myaddr; 1096 lwkt_sendmsg(netisr_cpuport(0), &rmsg->base.lmsg); 1097 } 1098 } 1099 1100 static void 1101 in_arpreply(struct mbuf *m, in_addr_t taddr, in_addr_t myaddr) 1102 { 1103 struct ifnet *ifp = m->m_pkthdr.rcvif; 1104 const uint8_t *enaddr; 1105 struct arphdr *ah; 1106 struct sockaddr sa; 1107 struct ether_header *eh; 1108 1109 ah = mtod(m, struct arphdr *); 1110 if (ntohs(ah->ar_op) != ARPOP_REQUEST) { 1111 m_freem(m); 1112 return; 1113 } 1114 1115 enaddr = (const uint8_t *)IF_LLADDR(ifp); 1116 if (taddr == myaddr) { 1117 /* I am the target */ 1118 memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); 1119 memcpy(ar_sha(ah), enaddr, ah->ar_hln); 1120 } else { 1121 struct llinfo_arp *la; 1122 struct rtentry *rt; 1123 1124 la = arplookup(taddr, FALSE, RTL_DONTREPORT, SIN_PROXY); 1125 if (la == NULL) { 1126 struct sockaddr_in sin; 1127 1128 if (!arp_proxyall) { 1129 m_freem(m); 1130 return; 1131 } 1132 1133 bzero(&sin, sizeof sin); 1134 sin.sin_family = AF_INET; 1135 sin.sin_len = sizeof sin; 1136 sin.sin_addr.s_addr = taddr; 1137 1138 rt = rtpurelookup((struct sockaddr *)&sin); 1139 if (rt == NULL) { 1140 m_freem(m); 1141 return; 1142 } 1143 --rt->rt_refcnt; 1144 /* 1145 * Don't send proxies for nodes on the same interface 1146 * as this one came out of, or we'll get into a fight 1147 * over who claims what Ether address. 1148 */ 1149 if (rt->rt_ifp == ifp) { 1150 m_freem(m); 1151 return; 1152 } 1153 memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); 1154 memcpy(ar_sha(ah), enaddr, ah->ar_hln); 1155 #ifdef DEBUG_PROXY 1156 kprintf("arp: proxying for %s\n", inet_ntoa(itaddr)); 1157 #endif 1158 } else { 1159 struct sockaddr_dl *sdl; 1160 1161 rt = la->la_rt; 1162 memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); 1163 sdl = SDL(rt->rt_gateway); 1164 memcpy(ar_sha(ah), LLADDR(sdl), ah->ar_hln); 1165 } 1166 } 1167 1168 memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); 1169 memcpy(ar_spa(ah), &taddr, ah->ar_pln); 1170 ah->ar_op = htons(ARPOP_REPLY); 1171 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 1172 switch (ifp->if_type) { 1173 case IFT_ETHER: 1174 /* 1175 * May not be correct for types not explictly 1176 * listed, but it is our best guess. 1177 */ 1178 default: 1179 eh = (struct ether_header *)sa.sa_data; 1180 memcpy(eh->ether_dhost, ar_tha(ah), sizeof eh->ether_dhost); 1181 eh->ether_type = htons(ETHERTYPE_ARP); 1182 break; 1183 } 1184 sa.sa_family = AF_UNSPEC; 1185 sa.sa_len = sizeof sa; 1186 ifp->if_output(ifp, m, &sa, NULL); 1187 } 1188 1189 #endif /* INET */ 1190 1191 /* 1192 * Free an arp entry. If the arp entry is actively referenced or represents 1193 * a static entry we only clear it back to an unresolved state, otherwise 1194 * we destroy the entry entirely. 1195 * 1196 * Note that static entries are created when route add ... -interface is used 1197 * to create an interface route to a (direct) destination. 1198 */ 1199 static void 1200 arptfree(struct llinfo_arp *la) 1201 { 1202 struct rtentry *rt = la->la_rt; 1203 struct sockaddr_dl *sdl; 1204 1205 if (rt == NULL) 1206 panic("arptfree"); 1207 sdl = SDL(rt->rt_gateway); 1208 if (sdl != NULL && 1209 ((rt->rt_refcnt > 0 && sdl->sdl_family == AF_LINK) || 1210 (rt->rt_flags & RTF_STATIC))) { 1211 sdl->sdl_alen = 0; 1212 la->la_preempt = la->la_asked = 0; 1213 rt->rt_flags &= ~RTF_REJECT; 1214 return; 1215 } 1216 rtrequest(RTM_DELETE, rt_key(rt), NULL, rt_mask(rt), 0, NULL); 1217 } 1218 1219 /* 1220 * Lookup or enter a new address in arptab. 1221 */ 1222 static struct llinfo_arp * 1223 arplookup(in_addr_t addr, boolean_t create, boolean_t generate_report, 1224 boolean_t proxy) 1225 { 1226 struct rtentry *rt; 1227 struct sockaddr_inarp sin = { sizeof sin, AF_INET }; 1228 const char *why = NULL; 1229 1230 sin.sin_addr.s_addr = addr; 1231 sin.sin_other = proxy ? SIN_PROXY : 0; 1232 if (create) { 1233 rt = _rtlookup((struct sockaddr *)&sin, 1234 generate_report, RTL_DOCLONE); 1235 } else { 1236 rt = rtpurelookup((struct sockaddr *)&sin); 1237 } 1238 if (rt == NULL) 1239 return (NULL); 1240 rt->rt_refcnt--; 1241 1242 if (rt->rt_flags & RTF_GATEWAY) 1243 why = "host is not on local network"; 1244 else if (!(rt->rt_flags & RTF_LLINFO)) 1245 why = "could not allocate llinfo"; 1246 else if (rt->rt_gateway->sa_family != AF_LINK) 1247 why = "gateway route is not ours"; 1248 1249 if (why) { 1250 if (create) { 1251 log(LOG_DEBUG, "arplookup %s failed: %s\n", 1252 inet_ntoa(sin.sin_addr), why); 1253 } 1254 if (rt->rt_refcnt <= 0 && (rt->rt_flags & RTF_WASCLONED)) { 1255 /* No references to this route. Purge it. */ 1256 rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway, 1257 rt_mask(rt), rt->rt_flags, NULL); 1258 } 1259 return (NULL); 1260 } 1261 return (rt->rt_llinfo); 1262 } 1263 1264 void 1265 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1266 { 1267 ifa->ifa_rtrequest = arp_rtrequest; 1268 ifa->ifa_flags |= RTF_CLONING; 1269 } 1270 1271 void 1272 arp_gratuitous(struct ifnet *ifp, struct ifaddr *ifa) 1273 { 1274 if (IA_SIN(ifa)->sin_addr.s_addr != INADDR_ANY) { 1275 arprequest_async(ifp, &IA_SIN(ifa)->sin_addr, 1276 &IA_SIN(ifa)->sin_addr, NULL); 1277 } 1278 } 1279 1280 static void 1281 arp_ifaddr(void *arg __unused, struct ifnet *ifp, 1282 enum ifaddr_event event, struct ifaddr *ifa) 1283 { 1284 if (ifa->ifa_rtrequest != arp_rtrequest) /* XXX need a generic way */ 1285 return; 1286 if (ifa->ifa_addr->sa_family != AF_INET) 1287 return; 1288 if (event == IFADDR_EVENT_DELETE) 1289 return; 1290 1291 /* 1292 * - CARP interfaces will take care of gratuitous ARP themselves. 1293 * - If we are the CARP interface's parent, don't send gratuitous 1294 * ARP to avoid unnecessary confusion. 1295 */ 1296 #ifdef CARP 1297 if (ifp->if_type != IFT_CARP && ifp->if_carp == NULL) 1298 #endif 1299 { 1300 arp_gratuitous(ifp, ifa); 1301 } 1302 } 1303 1304 static void 1305 arp_init(void) 1306 { 1307 int cpu; 1308 1309 for (cpu = 0; cpu < ncpus2; cpu++) 1310 LIST_INIT(&llinfo_arp_list[cpu]); 1311 1312 netisr_register(NETISR_ARP, arpintr, NULL); 1313 1314 EVENTHANDLER_REGISTER(ifaddr_event, arp_ifaddr, NULL, 1315 EVENTHANDLER_PRI_LAST); 1316 } 1317 1318 SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0); 1319