1 /* $NetBSD: if_arp.c,v 1.316 2024/10/04 23:31:06 roy Exp $ */ 2 3 /* 4 * Copyright (c) 1998, 2000, 2008 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Public Access Networks Corporation ("Panix"). It was developed under 9 * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF 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 8.2 (Berkeley) 9/26/94 62 */ 63 64 /* 65 * Ethernet address resolution protocol. 66 * TODO: 67 * add "inuse/lock" bit (or ref. count) along with valid bit 68 */ 69 70 #include <sys/cdefs.h> 71 __KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.316 2024/10/04 23:31:06 roy Exp $"); 72 73 #ifdef _KERNEL_OPT 74 #include "opt_ddb.h" 75 #include "opt_inet.h" 76 #include "opt_net_mpsafe.h" 77 #endif 78 79 #ifdef INET 80 81 #include "arp.h" 82 #include "bridge.h" 83 84 #include <sys/param.h> 85 #include <sys/systm.h> 86 #include <sys/callout.h> 87 #include <sys/kmem.h> 88 #include <sys/mbuf.h> 89 #include <sys/socket.h> 90 #include <sys/time.h> 91 #include <sys/timetc.h> 92 #include <sys/kernel.h> 93 #include <sys/errno.h> 94 #include <sys/ioctl.h> 95 #include <sys/syslog.h> 96 #include <sys/proc.h> 97 #include <sys/protosw.h> 98 #include <sys/domain.h> 99 #include <sys/sysctl.h> 100 #include <sys/socketvar.h> 101 #include <sys/percpu.h> 102 #include <sys/cprng.h> 103 #include <sys/kmem.h> 104 105 #include <net/ethertypes.h> 106 #include <net/if.h> 107 #include <net/if_dl.h> 108 #include <net/if_types.h> 109 #include <net/if_ether.h> 110 #include <net/if_llatbl.h> 111 #include <net/nd.h> 112 #include <net/route.h> 113 #include <net/net_stats.h> 114 115 #include <netinet/in.h> 116 #include <netinet/in_systm.h> 117 #include <netinet/in_var.h> 118 #include <netinet/ip.h> 119 #include <netinet/if_inarp.h> 120 121 #include "arcnet.h" 122 #if NARCNET > 0 123 #include <net/if_arc.h> 124 #endif 125 #include "carp.h" 126 #if NCARP > 0 127 #include <netinet/ip_carp.h> 128 #endif 129 130 /* 131 * ARP trailer negotiation. Trailer protocol is not IP specific, 132 * but ARP request/response use IP addresses. 133 */ 134 #define ETHERTYPE_IPTRAILERS ETHERTYPE_TRAIL 135 136 /* timers */ 137 static int arp_reachable = REACHABLE_TIME; 138 static int arp_retrans = RETRANS_TIMER; 139 static int arp_perform_nud = 1; 140 141 static bool arp_nud_enabled(struct ifnet *); 142 static unsigned int arp_llinfo_reachable(struct ifnet *); 143 static unsigned int arp_llinfo_retrans(struct ifnet *); 144 static union l3addr *arp_llinfo_holdsrc(struct llentry *, union l3addr *); 145 static void arp_llinfo_output(struct ifnet *, const union l3addr *, 146 const union l3addr *, const uint8_t *, const union l3addr *); 147 static void arp_llinfo_missed(struct ifnet *, const union l3addr *, 148 int16_t, struct mbuf *); 149 static void arp_free(struct llentry *, int); 150 151 static struct nd_domain arp_nd_domain = { 152 .nd_family = AF_INET, 153 .nd_delay = 5, /* delay first probe time 5 second */ 154 .nd_mmaxtries = 3, /* maximum broadcast query */ 155 .nd_umaxtries = 3, /* maximum unicast query */ 156 .nd_retransmultiple = BACKOFF_MULTIPLE, 157 .nd_maxretrans = MAX_RETRANS_TIMER, 158 .nd_maxnudhint = 0, /* max # of subsequent upper layer hints */ 159 .nd_maxqueuelen = 1, /* max # of packets in unresolved ND entries */ 160 .nd_nud_enabled = arp_nud_enabled, 161 .nd_reachable = arp_llinfo_reachable, 162 .nd_retrans = arp_llinfo_retrans, 163 .nd_holdsrc = arp_llinfo_holdsrc, 164 .nd_output = arp_llinfo_output, 165 .nd_missed = arp_llinfo_missed, 166 .nd_free = arp_free, 167 }; 168 169 int ip_dad_count = PROBE_NUM; 170 #ifdef ARP_DEBUG 171 int arp_debug = 1; 172 #else 173 int arp_debug = 0; 174 #endif 175 176 static void arp_init(void); 177 static void arp_dad_init(void); 178 179 static void arprequest(struct ifnet *, 180 const struct in_addr *, const struct in_addr *, 181 const uint8_t *, const uint8_t *); 182 static void arpannounce1(struct ifaddr *); 183 static struct sockaddr *arp_setgate(struct rtentry *, struct sockaddr *, 184 const struct sockaddr *); 185 static struct llentry *arpcreate(struct ifnet *, 186 const struct in_addr *, const struct sockaddr *, int); 187 static void in_arpinput(struct mbuf *); 188 static void in_revarpinput(struct mbuf *); 189 static void revarprequest(struct ifnet *); 190 191 static void arp_drainstub(void); 192 193 struct dadq; 194 static void arp_dad_timer(struct dadq *); 195 static void arp_dad_start(struct ifaddr *); 196 static void arp_dad_stop(struct ifaddr *); 197 static void arp_dad_duplicated(struct ifaddr *, const struct sockaddr_dl *); 198 199 #define ARP_MAXQLEN 50 200 pktqueue_t * arp_pktq __read_mostly; 201 202 static int useloopback = 1; /* use loopback interface for local traffic */ 203 204 static percpu_t *arpstat_percpu; 205 206 #define ARP_STAT_GETREF() _NET_STAT_GETREF(arpstat_percpu) 207 #define ARP_STAT_PUTREF() _NET_STAT_PUTREF(arpstat_percpu) 208 209 #define ARP_STATINC(x) _NET_STATINC(arpstat_percpu, x) 210 #define ARP_STATADD(x, v) _NET_STATADD(arpstat_percpu, x, v) 211 212 /* revarp state */ 213 static struct in_addr myip, srv_ip; 214 static int myip_initialized = 0; 215 static int revarp_in_progress = 0; 216 static struct ifnet *myip_ifp = NULL; 217 218 static int arp_drainwanted; 219 220 static int log_movements = 1; 221 static int log_permanent_modify = 1; 222 static int log_wrong_iface = 1; 223 224 DOMAIN_DEFINE(arpdomain); /* forward declare and add to link set */ 225 226 static void 227 arp_fasttimo(void) 228 { 229 if (arp_drainwanted) { 230 arp_drain(); 231 arp_drainwanted = 0; 232 } 233 } 234 235 static const struct protosw arpsw[] = { 236 { 237 .pr_type = 0, 238 .pr_domain = &arpdomain, 239 .pr_protocol = 0, 240 .pr_flags = 0, 241 .pr_input = 0, 242 .pr_ctlinput = 0, 243 .pr_ctloutput = 0, 244 .pr_usrreqs = 0, 245 .pr_init = arp_init, 246 .pr_fasttimo = arp_fasttimo, 247 .pr_slowtimo = 0, 248 .pr_drain = arp_drainstub, 249 } 250 }; 251 252 struct domain arpdomain = { 253 .dom_family = PF_ARP, 254 .dom_name = "arp", 255 .dom_protosw = arpsw, 256 .dom_protoswNPROTOSW = &arpsw[__arraycount(arpsw)], 257 #ifdef MBUFTRACE 258 .dom_mowner = MOWNER_INIT("internet", "arp"), 259 #endif 260 }; 261 262 static void sysctl_net_inet_arp_setup(struct sysctllog **); 263 264 void 265 arp_init(void) 266 { 267 268 arp_pktq = pktq_create(ARP_MAXQLEN, arpintr, NULL); 269 KASSERT(arp_pktq != NULL); 270 271 sysctl_net_inet_arp_setup(NULL); 272 arpstat_percpu = percpu_alloc(sizeof(uint64_t) * ARP_NSTATS); 273 274 #ifdef MBUFTRACE 275 MOWNER_ATTACH(&arpdomain.dom_mowner); 276 #endif 277 278 nd_attach_domain(&arp_nd_domain); 279 arp_dad_init(); 280 } 281 282 static void 283 arp_drainstub(void) 284 { 285 arp_drainwanted = 1; 286 } 287 288 /* 289 * ARP protocol drain routine. Called when memory is in short supply. 290 * Called at splvm(); don't acquire softnet_lock as can be called from 291 * hardware interrupt handlers. 292 */ 293 void 294 arp_drain(void) 295 { 296 297 lltable_drain(AF_INET); 298 } 299 300 /* 301 * We set the gateway for RTF_CLONING routes to a "prototype" 302 * link-layer sockaddr whose interface type (if_type) and interface 303 * index (if_index) fields are prepared. 304 */ 305 static struct sockaddr * 306 arp_setgate(struct rtentry *rt, struct sockaddr *gate, 307 const struct sockaddr *netmask) 308 { 309 const struct ifnet *ifp = rt->rt_ifp; 310 uint8_t namelen = strlen(ifp->if_xname); 311 uint8_t addrlen = ifp->if_addrlen; 312 313 /* 314 * XXX: If this is a manually added route to interface 315 * such as older version of routed or gated might provide, 316 * restore cloning bit. 317 */ 318 if ((rt->rt_flags & RTF_HOST) == 0 && netmask != NULL && 319 satocsin(netmask)->sin_addr.s_addr != 0xffffffff) 320 rt->rt_flags |= RTF_CONNECTED; 321 322 if ((rt->rt_flags & (RTF_CONNECTED | RTF_LOCAL))) { 323 union { 324 struct sockaddr sa; 325 struct sockaddr_storage ss; 326 struct sockaddr_dl sdl; 327 } u; 328 /* 329 * Case 1: This route should come from a route to iface. 330 */ 331 sockaddr_dl_init(&u.sdl, sizeof(u.ss), 332 ifp->if_index, ifp->if_type, NULL, namelen, NULL, addrlen); 333 rt_setgate(rt, &u.sa); 334 gate = rt->rt_gateway; 335 } 336 return gate; 337 } 338 339 /* 340 * Parallel to llc_rtrequest. 341 */ 342 void 343 arp_rtrequest(int req, struct rtentry *rt, const struct rt_addrinfo *info) 344 { 345 struct sockaddr *gate = rt->rt_gateway; 346 struct in_ifaddr *ia; 347 struct ifaddr *ifa; 348 struct ifnet *ifp = rt->rt_ifp; 349 int bound; 350 int s; 351 352 if (req == RTM_LLINFO_UPD) { 353 if ((ifa = info->rti_ifa) != NULL) 354 arpannounce1(ifa); 355 return; 356 } 357 358 if ((rt->rt_flags & RTF_GATEWAY) != 0) { 359 if (req != RTM_ADD) 360 return; 361 362 /* 363 * linklayers with particular link MTU limitation. 364 */ 365 switch(ifp->if_type) { 366 #if NARCNET > 0 367 case IFT_ARCNET: 368 { 369 int arcipifmtu; 370 371 if (ifp->if_flags & IFF_LINK0) 372 arcipifmtu = arc_ipmtu; 373 else 374 arcipifmtu = ARCMTU; 375 if (ifp->if_mtu > arcipifmtu) 376 rt->rt_rmx.rmx_mtu = arcipifmtu; 377 break; 378 } 379 #endif 380 } 381 return; 382 } 383 384 switch (req) { 385 case RTM_SETGATE: 386 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 387 break; 388 case RTM_ADD: 389 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 390 if (gate == NULL) { 391 log(LOG_ERR, "%s: arp_setgate failed\n", __func__); 392 break; 393 } 394 if ((rt->rt_flags & RTF_CONNECTED) || 395 (rt->rt_flags & RTF_LOCAL)) { 396 /* 397 * linklayers with particular link MTU limitation. 398 */ 399 switch (ifp->if_type) { 400 #if NARCNET > 0 401 case IFT_ARCNET: 402 { 403 int arcipifmtu; 404 if (ifp->if_flags & IFF_LINK0) 405 arcipifmtu = arc_ipmtu; 406 else 407 arcipifmtu = ARCMTU; 408 409 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 410 (rt->rt_rmx.rmx_mtu > arcipifmtu || 411 (rt->rt_rmx.rmx_mtu == 0 && 412 ifp->if_mtu > arcipifmtu))) 413 rt->rt_rmx.rmx_mtu = arcipifmtu; 414 break; 415 } 416 #endif 417 } 418 if (rt->rt_flags & RTF_CONNECTED) 419 break; 420 } 421 422 bound = curlwp_bind(); 423 /* Announce a new entry if requested. */ 424 if (rt->rt_flags & RTF_ANNOUNCE) { 425 struct psref psref; 426 ia = in_get_ia_on_iface_psref( 427 satocsin(rt_getkey(rt))->sin_addr, ifp, &psref); 428 if (ia != NULL) { 429 arpannounce(ifp, &ia->ia_ifa, 430 CLLADDR(satocsdl(gate))); 431 ia4_release(ia, &psref); 432 } 433 } 434 435 if (gate->sa_family != AF_LINK || 436 gate->sa_len < sockaddr_dl_measure(0, ifp->if_addrlen)) { 437 log(LOG_DEBUG, "%s: bad gateway value\n", __func__); 438 goto out; 439 } 440 441 satosdl(gate)->sdl_type = ifp->if_type; 442 satosdl(gate)->sdl_index = ifp->if_index; 443 444 /* 445 * If the route is for a broadcast address mark it as such. 446 * This way we can avoid an expensive call to in_broadcast() 447 * in ip_output() most of the time (because the route passed 448 * to ip_output() is almost always a host route). 449 */ 450 if (rt->rt_flags & RTF_HOST && 451 !(rt->rt_flags & RTF_BROADCAST) && 452 in_broadcast(satocsin(rt_getkey(rt))->sin_addr, rt->rt_ifp)) 453 rt->rt_flags |= RTF_BROADCAST; 454 /* There is little point in resolving the broadcast address */ 455 if (rt->rt_flags & RTF_BROADCAST) 456 goto out; 457 458 /* 459 * When called from rt_ifa_addlocal, we cannot depend on that 460 * the address (rt_getkey(rt)) exits in the address list of the 461 * interface. So check RTF_LOCAL instead. 462 */ 463 if (rt->rt_flags & RTF_LOCAL) { 464 if (useloopback) { 465 rt->rt_ifp = lo0ifp; 466 rt->rt_rmx.rmx_mtu = 0; 467 } 468 goto out; 469 } 470 471 s = pserialize_read_enter(); 472 ia = in_get_ia_on_iface(satocsin(rt_getkey(rt))->sin_addr, ifp); 473 if (ia == NULL) { 474 pserialize_read_exit(s); 475 goto out; 476 } 477 478 if (useloopback) { 479 rt->rt_ifp = lo0ifp; 480 rt->rt_rmx.rmx_mtu = 0; 481 } 482 rt->rt_flags |= RTF_LOCAL; 483 484 if (ISSET(info->rti_flags, RTF_DONTCHANGEIFA)) { 485 pserialize_read_exit(s); 486 goto out; 487 } 488 /* 489 * make sure to set rt->rt_ifa to the interface 490 * address we are using, otherwise we will have trouble 491 * with source address selection. 492 */ 493 ifa = &ia->ia_ifa; 494 if (ifa != rt->rt_ifa) 495 /* Assume it doesn't sleep */ 496 rt_replace_ifa(rt, ifa); 497 pserialize_read_exit(s); 498 out: 499 curlwp_bindx(bound); 500 break; 501 } 502 } 503 504 /* 505 * Broadcast an ARP request. Caller specifies: 506 * - arp header source ip address 507 * - arp header target ip address 508 * - arp header source ethernet address 509 */ 510 static void 511 arprequest(struct ifnet *ifp, 512 const struct in_addr *sip, const struct in_addr *tip, 513 const uint8_t *saddr, const uint8_t *taddr) 514 { 515 struct mbuf *m; 516 struct arphdr *ah; 517 struct sockaddr sa; 518 net_stat_ref_t arps; 519 520 KASSERT(sip != NULL); 521 KASSERT(tip != NULL); 522 KASSERT(saddr != NULL); 523 524 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 525 return; 526 MCLAIM(m, &arpdomain.dom_mowner); 527 switch (ifp->if_type) { 528 case IFT_IEEE1394: 529 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 530 ifp->if_addrlen; 531 break; 532 default: 533 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 534 2 * ifp->if_addrlen; 535 break; 536 } 537 m->m_pkthdr.len = m->m_len; 538 m_align(m, m->m_len); 539 ah = mtod(m, struct arphdr *); 540 memset(ah, 0, m->m_len); 541 switch (ifp->if_type) { 542 case IFT_IEEE1394: /* RFC2734 */ 543 /* fill it now for ar_tpa computation */ 544 ah->ar_hrd = htons(ARPHRD_IEEE1394); 545 break; 546 default: 547 /* ifp->if_output will fill ar_hrd */ 548 break; 549 } 550 ah->ar_pro = htons(ETHERTYPE_IP); 551 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 552 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 553 ah->ar_op = htons(ARPOP_REQUEST); 554 memcpy(ar_sha(ah), saddr, ah->ar_hln); 555 if (taddr == NULL) 556 m->m_flags |= M_BCAST; 557 else 558 memcpy(ar_tha(ah), taddr, ah->ar_hln); 559 memcpy(ar_spa(ah), sip, ah->ar_pln); 560 memcpy(ar_tpa(ah), tip, ah->ar_pln); 561 sa.sa_family = AF_ARP; 562 sa.sa_len = 2; 563 arps = ARP_STAT_GETREF(); 564 _NET_STATINC_REF(arps, ARP_STAT_SNDTOTAL); 565 _NET_STATINC_REF(arps, ARP_STAT_SENDREQUEST); 566 ARP_STAT_PUTREF(); 567 if_output_lock(ifp, ifp, m, &sa, NULL); 568 } 569 570 void 571 arpannounce(struct ifnet *ifp, struct ifaddr *ifa, const uint8_t *enaddr) 572 { 573 struct in_ifaddr *ia = ifatoia(ifa); 574 struct in_addr *ip = &IA_SIN(ifa)->sin_addr; 575 576 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) { 577 ARPLOG(LOG_DEBUG, "%s not ready\n", ARPLOGADDR(ip)); 578 return; 579 } 580 arprequest(ifp, ip, ip, enaddr, NULL); 581 } 582 583 static void 584 arpannounce1(struct ifaddr *ifa) 585 { 586 587 arpannounce(ifa->ifa_ifp, ifa, CLLADDR(ifa->ifa_ifp->if_sadl)); 588 } 589 590 /* 591 * Resolve an IP address into an ethernet address. If success, desten is 592 * filled in. If there is no entry in arptab, set one up and broadcast a 593 * request for the IP address. Hold onto this mbuf and resend it once the 594 * address is finally resolved. 595 * 596 * A return value of 0 indicates that desten has been filled in and the packet 597 * should be sent normally; a return value of EWOULDBLOCK indicates that the 598 * packet has been held pending resolution. Any other value indicates an 599 * error. 600 */ 601 int 602 arpresolve(struct ifnet *ifp, const struct rtentry *rt, struct mbuf *m, 603 const struct sockaddr *dst, void *desten, size_t destlen) 604 { 605 struct llentry *la; 606 const char *create_lookup; 607 int error; 608 609 #if NCARP > 0 610 if (rt != NULL && rt->rt_ifp->if_type == IFT_CARP) 611 ifp = rt->rt_ifp; 612 #endif 613 614 KASSERT(m != NULL); 615 616 la = arplookup(ifp, NULL, dst, 0); 617 if (la == NULL) 618 goto notfound; 619 620 if (la->la_flags & LLE_VALID && la->ln_state == ND_LLINFO_REACHABLE) { 621 KASSERT(destlen >= ifp->if_addrlen); 622 memcpy(desten, &la->ll_addr, ifp->if_addrlen); 623 LLE_RUNLOCK(la); 624 return 0; 625 } 626 627 notfound: 628 if (ifp->if_flags & IFF_NOARP) { 629 if (la != NULL) 630 LLE_RUNLOCK(la); 631 error = ENOTSUP; 632 goto bad; 633 } 634 635 if (la == NULL) { 636 struct rtentry *_rt; 637 638 create_lookup = "create"; 639 _rt = rtalloc1(dst, 0); 640 IF_AFDATA_WLOCK(ifp); 641 la = lla_create(LLTABLE(ifp), LLE_EXCLUSIVE, dst, _rt); 642 IF_AFDATA_WUNLOCK(ifp); 643 if (_rt != NULL) 644 rt_unref(_rt); 645 if (la == NULL) 646 ARP_STATINC(ARP_STAT_ALLOCFAIL); 647 else 648 la->ln_state = ND_LLINFO_NOSTATE; 649 } else if (LLE_TRY_UPGRADE(la) == 0) { 650 create_lookup = "lookup"; 651 LLE_RUNLOCK(la); 652 IF_AFDATA_RLOCK(ifp); 653 la = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst); 654 IF_AFDATA_RUNLOCK(ifp); 655 } 656 657 error = EINVAL; 658 if (la == NULL) { 659 log(LOG_DEBUG, 660 "%s: failed to %s llentry for %s on %s\n", 661 __func__, create_lookup, inet_ntoa(satocsin(dst)->sin_addr), 662 ifp->if_xname); 663 goto bad; 664 } 665 666 error = nd_resolve(la, rt, m, desten, destlen); 667 return error; 668 669 bad: 670 m_freem(m); 671 return error; 672 } 673 674 /* 675 * Common length and type checks are done here, 676 * then the protocol-specific routine is called. 677 */ 678 void 679 arpintr(void *arg __unused) 680 { 681 struct mbuf *m; 682 struct arphdr *ar; 683 int s; 684 int arplen; 685 struct ifnet *rcvif; 686 bool badhrd; 687 688 SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE(); 689 while ((m = pktq_dequeue(arp_pktq)) != NULL) { 690 if ((m->m_flags & M_PKTHDR) == 0) 691 panic("arpintr"); 692 693 MCLAIM(m, &arpdomain.dom_mowner); 694 ARP_STATINC(ARP_STAT_RCVTOTAL); 695 696 if (__predict_false(m->m_len < sizeof(*ar))) { 697 if ((m = m_pullup(m, sizeof(*ar))) == NULL) 698 goto badlen; 699 } 700 ar = mtod(m, struct arphdr *); 701 KASSERT(ACCESSIBLE_POINTER(ar, struct arphdr)); 702 703 rcvif = m_get_rcvif(m, &s); 704 if (__predict_false(rcvif == NULL)) { 705 ARP_STATINC(ARP_STAT_RCVNOINT); 706 goto free; 707 } 708 709 /* 710 * We don't want non-IEEE1394 ARP packets on IEEE1394 711 * interfaces, and vice versa. Our life depends on that. 712 */ 713 if (ntohs(ar->ar_hrd) == ARPHRD_IEEE1394) 714 badhrd = rcvif->if_type != IFT_IEEE1394; 715 else 716 badhrd = rcvif->if_type == IFT_IEEE1394; 717 718 m_put_rcvif(rcvif, &s); 719 720 if (badhrd) { 721 ARP_STATINC(ARP_STAT_RCVBADPROTO); 722 goto free; 723 } 724 725 arplen = sizeof(*ar) + 2 * ar->ar_hln + 2 * ar->ar_pln; 726 if (__predict_false(m->m_len < arplen)) { 727 if ((m = m_pullup(m, arplen)) == NULL) 728 goto badlen; 729 ar = mtod(m, struct arphdr *); 730 KASSERT(ACCESSIBLE_POINTER(ar, struct arphdr)); 731 } 732 733 switch (ntohs(ar->ar_pro)) { 734 case ETHERTYPE_IP: 735 case ETHERTYPE_IPTRAILERS: 736 in_arpinput(m); 737 continue; 738 default: 739 ARP_STATINC(ARP_STAT_RCVBADPROTO); 740 goto free; 741 } 742 743 badlen: 744 ARP_STATINC(ARP_STAT_RCVBADLEN); 745 free: 746 m_freem(m); 747 } 748 SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 749 return; /* XXX gcc */ 750 } 751 752 /* 753 * ARP for Internet protocols on 10 Mb/s Ethernet. Algorithm is that given in 754 * RFC 826. In addition, a sanity check is performed on the sender protocol 755 * address, to catch impersonators. 756 * 757 * We no longer handle negotiations for use of trailer protocol: formerly, ARP 758 * replied for protocol type ETHERTYPE_TRAIL sent along with IP replies if we 759 * wanted trailers sent to us, and also sent them in response to IP replies. 760 * This allowed either end to announce the desire to receive trailer packets. 761 * 762 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, but 763 * formerly didn't normally send requests. 764 */ 765 static void 766 in_arpinput(struct mbuf *m) 767 { 768 struct arphdr *ah; 769 struct ifnet *ifp, *rcvif = NULL; 770 struct llentry *la = NULL; 771 struct in_ifaddr *ia = NULL; 772 #if NBRIDGE > 0 773 struct in_ifaddr *bridge_ia = NULL; 774 #endif 775 #if NCARP > 0 776 uint32_t count = 0, index = 0; 777 #endif 778 struct sockaddr sa; 779 struct in_addr isaddr, itaddr, myaddr; 780 int op, rt_cmd, new_state = 0; 781 void *tha; 782 net_stat_ref_t arps; 783 struct psref psref, psref_ia; 784 int s; 785 char ipbuf[INET_ADDRSTRLEN]; 786 bool find_source, do_dad; 787 788 if (__predict_false(m_makewritable(&m, 0, m->m_pkthdr.len, M_DONTWAIT))) 789 goto out; 790 ah = mtod(m, struct arphdr *); 791 op = ntohs(ah->ar_op); 792 793 if (ah->ar_pln != sizeof(struct in_addr)) 794 goto out; 795 796 rcvif = ifp = m_get_rcvif_psref(m, &psref); 797 if (__predict_false(rcvif == NULL)) 798 goto out; 799 if (rcvif->if_flags & IFF_NOARP) 800 goto out; 801 802 memcpy(&isaddr, ar_spa(ah), sizeof(isaddr)); 803 memcpy(&itaddr, ar_tpa(ah), sizeof(itaddr)); 804 805 if (m->m_flags & (M_BCAST|M_MCAST)) 806 ARP_STATINC(ARP_STAT_RCVMCAST); 807 808 /* 809 * Search for a matching interface address 810 * or any address on the interface to use 811 * as a dummy address in the rest of this function. 812 * 813 * First try and find the source address for early 814 * duplicate address detection. 815 */ 816 if (in_nullhost(isaddr)) { 817 if (in_nullhost(itaddr)) /* very bogus ARP */ 818 goto out; 819 find_source = false; 820 myaddr = itaddr; 821 } else { 822 find_source = true; 823 myaddr = isaddr; 824 } 825 s = pserialize_read_enter(); 826 again: 827 IN_ADDRHASH_READER_FOREACH(ia, myaddr.s_addr) { 828 if (!in_hosteq(ia->ia_addr.sin_addr, myaddr)) 829 continue; 830 #if NCARP > 0 831 if (ia->ia_ifp->if_type == IFT_CARP && 832 ((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) == 833 (IFF_UP|IFF_RUNNING))) { 834 index++; 835 /* XXX: ar_hln? */ 836 if (ia->ia_ifp == rcvif && (ah->ar_hln >= 6) && 837 carp_iamatch(ia, ar_sha(ah), 838 &count, index)) { 839 break; 840 } 841 } else 842 #endif 843 if (ia->ia_ifp == rcvif) 844 break; 845 #if NBRIDGE > 0 846 /* 847 * If the interface we received the packet on 848 * is part of a bridge, check to see if we need 849 * to "bridge" the packet to ourselves at this 850 * layer. Note we still prefer a perfect match, 851 * but allow this weaker match if necessary. 852 */ 853 if (rcvif->if_bridge != NULL && 854 rcvif->if_bridge == ia->ia_ifp->if_bridge) 855 bridge_ia = ia; 856 #endif 857 } 858 859 #if NBRIDGE > 0 860 if (ia == NULL && bridge_ia != NULL) { 861 ia = bridge_ia; 862 m_put_rcvif_psref(rcvif, &psref); 863 rcvif = NULL; 864 /* FIXME */ 865 ifp = bridge_ia->ia_ifp; 866 } 867 #endif 868 869 /* If we failed to find the source address then find 870 * the target address. */ 871 if (ia == NULL && find_source && !in_nullhost(itaddr)) { 872 find_source = false; 873 myaddr = itaddr; 874 goto again; 875 } 876 877 if (ia != NULL) 878 ia4_acquire(ia, &psref_ia); 879 pserialize_read_exit(s); 880 881 if (ah->ar_hln != ifp->if_addrlen) { 882 ARP_STATINC(ARP_STAT_RCVBADLEN); 883 log(LOG_WARNING, 884 "arp from %s: addr len: new %d, i/f %d (ignored)\n", 885 IN_PRINT(ipbuf, &isaddr), ah->ar_hln, ifp->if_addrlen); 886 goto out; 887 } 888 889 /* Only do DaD if we have a matching address. */ 890 do_dad = (ia != NULL); 891 892 if (ia == NULL) { 893 ia = in_get_ia_on_iface_psref(isaddr, rcvif, &psref_ia); 894 if (ia == NULL) { 895 ia = in_get_ia_from_ifp_psref(ifp, &psref_ia); 896 if (ia == NULL) { 897 ARP_STATINC(ARP_STAT_RCVNOINT); 898 goto out; 899 } 900 } 901 } 902 903 myaddr = ia->ia_addr.sin_addr; 904 905 /* XXX checks for bridge case? */ 906 if (!memcmp(ar_sha(ah), CLLADDR(ifp->if_sadl), ifp->if_addrlen)) { 907 ARP_STATINC(ARP_STAT_RCVLOCALSHA); 908 goto out; /* it's from me, ignore it. */ 909 } 910 911 /* XXX checks for bridge case? */ 912 if (!memcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 913 ARP_STATINC(ARP_STAT_RCVBCASTSHA); 914 log(LOG_ERR, 915 "%s: arp: link address is broadcast for IP address %s!\n", 916 ifp->if_xname, IN_PRINT(ipbuf, &isaddr)); 917 goto out; 918 } 919 920 /* 921 * If the source IP address is zero, this is an RFC 5227 ARP probe 922 */ 923 if (in_nullhost(isaddr)) 924 ARP_STATINC(ARP_STAT_RCVZEROSPA); 925 else if (in_hosteq(isaddr, myaddr)) { 926 ARP_STATINC(ARP_STAT_RCVLOCALSPA); 927 /* This is the original behavior prior to supporting IPv4 DAD */ 928 if (!ip_dad_enabled()) { 929 char llabuf[LLA_ADDRSTRLEN]; 930 log(LOG_ERR, 931 "duplicate IP address %s sent from link address %s\n", 932 IN_PRINT(ipbuf, &isaddr), 933 lla_snprintf(llabuf, sizeof(llabuf), ar_sha(ah), 934 ah->ar_hln)); 935 itaddr = myaddr; 936 goto reply; 937 } 938 } 939 940 if (in_nullhost(itaddr)) 941 ARP_STATINC(ARP_STAT_RCVZEROTPA); 942 943 /* 944 * DAD check, RFC 5227. 945 * ARP sender hardware address must match the interface 946 * address of the interface sending the packet. 947 * Collision on sender address is always a duplicate. 948 * Collision on target address is only a duplicate 949 * IF the sender address is the null host (ie a DAD probe) 950 * AND the message was broadcast 951 * AND our address is either tentative or duplicated 952 * If it was unicast then it's a valid Unicast Poll from RFC 1122. 953 */ 954 if (ip_dad_enabled() && do_dad && 955 (in_hosteq(isaddr, myaddr) || 956 (in_nullhost(isaddr) && in_hosteq(itaddr, myaddr) && 957 m->m_flags & M_BCAST && 958 ia->ia4_flags & (IN_IFF_TENTATIVE | IN_IFF_DUPLICATED)))) 959 { 960 struct m_tag *mtag; 961 962 mtag = m_tag_find(m, PACKET_TAG_ETHERNET_SRC); 963 if (mtag == NULL || (ah->ar_hln == ETHER_ADDR_LEN && 964 memcmp(mtag + 1, ar_sha(ah), ah->ar_hln) == 0)) { 965 struct sockaddr_dl sdl, *sdlp; 966 967 sdlp = sockaddr_dl_init(&sdl, sizeof(sdl), 968 ifp->if_index, ifp->if_type, 969 NULL, 0, ar_sha(ah), ah->ar_hln); 970 arp_dad_duplicated((struct ifaddr *)ia, sdlp); 971 goto out; 972 } 973 } 974 975 /* 976 * If the target IP address is zero, ignore the packet. 977 * This prevents the code below from trying to answer 978 * when we are using IP address zero (booting). 979 */ 980 if (in_nullhost(itaddr)) 981 goto out; 982 983 if (in_nullhost(isaddr)) 984 goto reply; 985 986 if (in_hosteq(itaddr, myaddr)) 987 la = arpcreate(ifp, &isaddr, NULL, 1); 988 else 989 la = arplookup(ifp, &isaddr, NULL, 1); 990 if (la == NULL) 991 goto reply; 992 993 if ((la->la_flags & LLE_VALID) && 994 memcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) 995 { 996 char llabuf[LLA_ADDRSTRLEN], *llastr; 997 998 llastr = lla_snprintf(llabuf, sizeof(llabuf), 999 ar_sha(ah), ah->ar_hln); 1000 1001 if (la->la_flags & LLE_STATIC) { 1002 ARP_STATINC(ARP_STAT_RCVOVERPERM); 1003 if (!log_permanent_modify) 1004 goto out; 1005 log(LOG_INFO, 1006 "%s tried to overwrite permanent arp info" 1007 " for %s\n", llastr, IN_PRINT(ipbuf, &isaddr)); 1008 goto out; 1009 } else if (la->lle_tbl->llt_ifp != ifp) { 1010 /* XXX should not happen? */ 1011 ARP_STATINC(ARP_STAT_RCVOVERINT); 1012 if (!log_wrong_iface) 1013 goto out; 1014 log(LOG_INFO, 1015 "%s on %s tried to overwrite " 1016 "arp info for %s on %s\n", 1017 llastr, 1018 ifp->if_xname, IN_PRINT(ipbuf, &isaddr), 1019 la->lle_tbl->llt_ifp->if_xname); 1020 goto out; 1021 } else { 1022 ARP_STATINC(ARP_STAT_RCVOVER); 1023 if (log_movements) 1024 log(LOG_INFO, "arp info overwritten " 1025 "for %s by %s\n", 1026 IN_PRINT(ipbuf, &isaddr), llastr); 1027 } 1028 rt_cmd = RTM_CHANGE; 1029 new_state = ND_LLINFO_STALE; 1030 } else { 1031 if (op == ARPOP_REPLY && in_hosteq(itaddr, myaddr)) { 1032 /* This was a solicited ARP reply. */ 1033 la->ln_byhint = 0; 1034 new_state = ND_LLINFO_REACHABLE; 1035 } else if (op == ARPOP_REQUEST && 1036 (la->ln_state == ND_LLINFO_NOSTATE || 1037 la->ln_state == ND_LLINFO_INCOMPLETE)) { 1038 /* 1039 * If an ARP request comes but there is no entry 1040 * and a new one has been created or an entry exists 1041 * but incomplete, make it stale to allow to send 1042 * packets to the requester without an ARP resolution. 1043 */ 1044 la->ln_byhint = 0; 1045 new_state = ND_LLINFO_STALE; 1046 } 1047 rt_cmd = la->la_flags & LLE_VALID ? 0 : RTM_ADD; 1048 } 1049 1050 KASSERT(ifp->if_sadl->sdl_alen == ifp->if_addrlen); 1051 1052 KASSERT(sizeof(la->ll_addr) >= ifp->if_addrlen); 1053 memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen); 1054 la->la_flags |= LLE_VALID; 1055 la->ln_asked = 0; 1056 if (new_state != 0) { 1057 la->ln_state = new_state; 1058 1059 if (new_state != ND_LLINFO_REACHABLE || 1060 !(la->la_flags & LLE_STATIC)) 1061 { 1062 int timer = ND_TIMER_GC; 1063 1064 if (new_state == ND_LLINFO_REACHABLE) 1065 timer = ND_TIMER_REACHABLE; 1066 nd_set_timer(la, timer); 1067 } 1068 } 1069 1070 if (rt_cmd != 0) { 1071 struct sockaddr_in sin; 1072 1073 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 1074 rt_clonedmsg(rt_cmd, NULL, sintosa(&sin), ar_sha(ah), ifp); 1075 } 1076 1077 if (la->la_hold != NULL) { 1078 int n = la->la_numheld; 1079 struct mbuf *m_hold, *m_hold_next; 1080 struct sockaddr_in sin; 1081 1082 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 1083 1084 m_hold = la->la_hold; 1085 la->la_hold = NULL; 1086 la->la_numheld = 0; 1087 /* 1088 * We have to unlock here because if_output would call 1089 * arpresolve 1090 */ 1091 LLE_WUNLOCK(la); 1092 ARP_STATADD(ARP_STAT_DFRSENT, n); 1093 ARP_STATADD(ARP_STAT_DFRTOTAL, n); 1094 for (; m_hold != NULL; m_hold = m_hold_next) { 1095 m_hold_next = m_hold->m_nextpkt; 1096 m_hold->m_nextpkt = NULL; 1097 if_output_lock(ifp, ifp, m_hold, sintosa(&sin), NULL); 1098 } 1099 } else 1100 LLE_WUNLOCK(la); 1101 la = NULL; 1102 1103 reply: 1104 if (la != NULL) { 1105 LLE_WUNLOCK(la); 1106 la = NULL; 1107 } 1108 if (op != ARPOP_REQUEST) { 1109 if (op == ARPOP_REPLY) 1110 ARP_STATINC(ARP_STAT_RCVREPLY); 1111 goto out; 1112 } 1113 ARP_STATINC(ARP_STAT_RCVREQUEST); 1114 if (in_hosteq(itaddr, myaddr)) { 1115 /* If our address is unusable, don't reply */ 1116 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) 1117 goto out; 1118 /* I am the target */ 1119 tha = ar_tha(ah); 1120 if (tha) 1121 memcpy(tha, ar_sha(ah), ah->ar_hln); 1122 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1123 } else { 1124 /* Proxy ARP */ 1125 struct llentry *lle = NULL; 1126 struct sockaddr_in sin; 1127 1128 #if NCARP > 0 1129 if (ifp->if_type == IFT_CARP) { 1130 struct ifnet *_rcvif = m_get_rcvif(m, &s); 1131 int iftype = 0; 1132 if (__predict_true(_rcvif != NULL)) 1133 iftype = _rcvif->if_type; 1134 m_put_rcvif(_rcvif, &s); 1135 if (iftype != IFT_CARP) 1136 goto out; 1137 } 1138 #endif 1139 1140 tha = ar_tha(ah); 1141 1142 sockaddr_in_init(&sin, &itaddr, 0); 1143 1144 IF_AFDATA_RLOCK(ifp); 1145 lle = lla_lookup(LLTABLE(ifp), 0, (struct sockaddr *)&sin); 1146 IF_AFDATA_RUNLOCK(ifp); 1147 1148 if ((lle != NULL) && (lle->la_flags & LLE_PUB)) { 1149 if (tha) 1150 memcpy(tha, ar_sha(ah), ah->ar_hln); 1151 memcpy(ar_sha(ah), &lle->ll_addr, ah->ar_hln); 1152 LLE_RUNLOCK(lle); 1153 } else { 1154 if (lle != NULL) 1155 LLE_RUNLOCK(lle); 1156 goto out; 1157 } 1158 } 1159 ia4_release(ia, &psref_ia); 1160 1161 /* 1162 * XXX XXX: Here we're recycling the mbuf. But the mbuf could have 1163 * other mbufs in its chain, and just overwriting m->m_pkthdr.len 1164 * would be wrong in this case (the length becomes smaller than the 1165 * real chain size). 1166 * 1167 * This can theoretically cause bugs in the lower layers (drivers, 1168 * and L2encap), in some corner cases. 1169 */ 1170 memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); 1171 memcpy(ar_spa(ah), &itaddr, ah->ar_pln); 1172 ah->ar_op = htons(ARPOP_REPLY); 1173 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 1174 switch (ifp->if_type) { 1175 case IFT_IEEE1394: 1176 /* ieee1394 arp reply is broadcast */ 1177 m->m_flags &= ~M_MCAST; 1178 m->m_flags |= M_BCAST; 1179 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + ah->ar_hln; 1180 break; 1181 default: 1182 m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */ 1183 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); 1184 break; 1185 } 1186 m->m_pkthdr.len = m->m_len; 1187 sa.sa_family = AF_ARP; 1188 sa.sa_len = 2; 1189 arps = ARP_STAT_GETREF(); 1190 _NET_STATINC_REF(arps, ARP_STAT_SNDTOTAL); 1191 _NET_STATINC_REF(arps, ARP_STAT_SNDREPLY); 1192 ARP_STAT_PUTREF(); 1193 if_output_lock(ifp, ifp, m, &sa, NULL); 1194 if (rcvif != NULL) 1195 m_put_rcvif_psref(rcvif, &psref); 1196 return; 1197 1198 out: 1199 if (la != NULL) 1200 LLE_WUNLOCK(la); 1201 if (ia != NULL) 1202 ia4_release(ia, &psref_ia); 1203 if (rcvif != NULL) 1204 m_put_rcvif_psref(rcvif, &psref); 1205 m_freem(m); 1206 } 1207 1208 /* 1209 * Lookup or a new address in arptab. 1210 */ 1211 struct llentry * 1212 arplookup(struct ifnet *ifp, const struct in_addr *addr, 1213 const struct sockaddr *sa, int wlock) 1214 { 1215 struct sockaddr_in sin; 1216 struct llentry *la; 1217 int flags = wlock ? LLE_EXCLUSIVE : 0; 1218 1219 if (sa == NULL) { 1220 KASSERT(addr != NULL); 1221 sockaddr_in_init(&sin, addr, 0); 1222 sa = sintocsa(&sin); 1223 } 1224 1225 IF_AFDATA_RLOCK(ifp); 1226 la = lla_lookup(LLTABLE(ifp), flags, sa); 1227 IF_AFDATA_RUNLOCK(ifp); 1228 1229 return la; 1230 } 1231 1232 static struct llentry * 1233 arpcreate(struct ifnet *ifp, const struct in_addr *addr, 1234 const struct sockaddr *sa, int wlock) 1235 { 1236 struct sockaddr_in sin; 1237 struct llentry *la; 1238 int flags = wlock ? LLE_EXCLUSIVE : 0; 1239 1240 if (sa == NULL) { 1241 KASSERT(addr != NULL); 1242 sockaddr_in_init(&sin, addr, 0); 1243 sa = sintocsa(&sin); 1244 } 1245 1246 la = arplookup(ifp, addr, sa, wlock); 1247 1248 if (la == NULL) { 1249 struct rtentry *rt; 1250 1251 rt = rtalloc1(sa, 0); 1252 IF_AFDATA_WLOCK(ifp); 1253 la = lla_create(LLTABLE(ifp), flags, sa, rt); 1254 IF_AFDATA_WUNLOCK(ifp); 1255 if (rt != NULL) 1256 rt_unref(rt); 1257 1258 if (la != NULL) 1259 la->ln_state = ND_LLINFO_NOSTATE; 1260 } 1261 1262 return la; 1263 } 1264 1265 int 1266 arpioctl(u_long cmd, void *data) 1267 { 1268 1269 return EOPNOTSUPP; 1270 } 1271 1272 void 1273 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1274 { 1275 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1276 1277 ifa->ifa_rtrequest = arp_rtrequest; 1278 ifa->ifa_flags |= RTF_CONNECTED; 1279 1280 /* ARP will handle DAD for this address. */ 1281 if (in_nullhost(IA_SIN(ifa)->sin_addr)) { 1282 if (ia->ia_dad_stop != NULL) /* safety */ 1283 ia->ia_dad_stop(ifa); 1284 ia->ia_dad_start = NULL; 1285 ia->ia_dad_stop = NULL; 1286 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1287 } else { 1288 ia->ia_dad_start = arp_dad_start; 1289 ia->ia_dad_stop = arp_dad_stop; 1290 if (ia->ia4_flags & IN_IFF_TRYTENTATIVE && ip_dad_enabled()) 1291 ia->ia4_flags |= IN_IFF_TENTATIVE; 1292 else 1293 arpannounce1(ifa); 1294 } 1295 } 1296 1297 static bool 1298 arp_nud_enabled(__unused struct ifnet *ifp) 1299 { 1300 1301 return arp_perform_nud != 0; 1302 } 1303 1304 static unsigned int 1305 arp_llinfo_reachable(__unused struct ifnet *ifp) 1306 { 1307 1308 return arp_reachable; 1309 } 1310 1311 static unsigned int 1312 arp_llinfo_retrans(__unused struct ifnet *ifp) 1313 { 1314 1315 return arp_retrans; 1316 } 1317 1318 /* 1319 * Gets source address of the first packet in hold queue 1320 * and stores it in @src. 1321 * Returns pointer to @src (if hold queue is not empty) or NULL. 1322 */ 1323 static union l3addr * 1324 arp_llinfo_holdsrc(struct llentry *ln, union l3addr *src) 1325 { 1326 struct ip *ip; 1327 1328 if (ln == NULL || ln->ln_hold == NULL) 1329 return NULL; 1330 1331 /* 1332 * assuming every packet in ln_hold has the same IP header 1333 */ 1334 ip = mtod(ln->ln_hold, struct ip *); 1335 /* XXX pullup? */ 1336 if (sizeof(*ip) < ln->ln_hold->m_len) 1337 src->addr4 = ip->ip_src; 1338 else 1339 src = NULL; 1340 1341 return src; 1342 } 1343 1344 static void 1345 arp_llinfo_output(struct ifnet *ifp, __unused const union l3addr *daddr, 1346 const union l3addr *taddr, const uint8_t *tlladdr, 1347 const union l3addr *hsrc) 1348 { 1349 struct in_addr tip = taddr->addr4, sip = zeroin_addr; 1350 const uint8_t *slladdr = CLLADDR(ifp->if_sadl); 1351 1352 if (hsrc != NULL) { 1353 struct in_ifaddr *ia; 1354 struct psref psref; 1355 1356 ia = in_get_ia_on_iface_psref(hsrc->addr4, ifp, &psref); 1357 if (ia != NULL) { 1358 sip = hsrc->addr4; 1359 ia4_release(ia, &psref); 1360 } 1361 } 1362 1363 if (sip.s_addr == INADDR_ANY) { 1364 struct sockaddr_in dst; 1365 struct rtentry *rt; 1366 1367 sockaddr_in_init(&dst, &tip, 0); 1368 rt = rtalloc1(sintosa(&dst), 0); 1369 if (rt != NULL) { 1370 if (rt->rt_ifp == ifp && 1371 rt->rt_ifa != NULL && 1372 rt->rt_ifa->ifa_addr->sa_family == AF_INET) 1373 sip = satosin(rt->rt_ifa->ifa_addr)->sin_addr; 1374 rt_unref(rt); 1375 } 1376 if (sip.s_addr == INADDR_ANY) { 1377 char ipbuf[INET_ADDRSTRLEN]; 1378 1379 log(LOG_DEBUG, "%s: source can't be " 1380 "determined: dst=%s\n", __func__, 1381 IN_PRINT(ipbuf, &tip)); 1382 return; 1383 } 1384 } 1385 1386 arprequest(ifp, &sip, &tip, slladdr, tlladdr); 1387 } 1388 1389 1390 static void 1391 arp_llinfo_missed(struct ifnet *ifp, const union l3addr *taddr, 1392 __unused int16_t type, struct mbuf *m) 1393 { 1394 struct in_addr mdaddr = zeroin_addr; 1395 struct sockaddr_in dsin, tsin; 1396 struct sockaddr *sa; 1397 1398 if (m != NULL) { 1399 struct ip *ip = mtod(m, struct ip *); 1400 1401 if (sizeof(*ip) < m->m_len) 1402 mdaddr = ip->ip_src; 1403 1404 /* ip_input() will send ICMP_UNREACH_HOST, not us. */ 1405 m_freem(m); 1406 } 1407 1408 if (mdaddr.s_addr != INADDR_ANY) { 1409 sockaddr_in_init(&dsin, &mdaddr, 0); 1410 sa = sintosa(&dsin); 1411 } else 1412 sa = NULL; 1413 1414 sockaddr_in_init(&tsin, &taddr->addr4, 0); 1415 rt_clonedmsg(RTM_MISS, sa, sintosa(&tsin), NULL, ifp); 1416 } 1417 1418 static void 1419 arp_free(struct llentry *ln, int gc) 1420 { 1421 struct ifnet *ifp; 1422 1423 KASSERT(ln != NULL); 1424 LLE_WLOCK_ASSERT(ln); 1425 1426 ifp = ln->lle_tbl->llt_ifp; 1427 1428 if (ln->la_flags & LLE_VALID || gc) { 1429 struct sockaddr_in sin; 1430 const char *lladdr; 1431 1432 sockaddr_in_init(&sin, &ln->r_l3addr.addr4, 0); 1433 lladdr = ln->la_flags & LLE_VALID ? 1434 (const char *)&ln->ll_addr : NULL; 1435 rt_clonedmsg(RTM_DELETE, NULL, sintosa(&sin), lladdr, ifp); 1436 } 1437 1438 /* 1439 * Save to unlock. We still hold an extra reference and will not 1440 * free(9) in llentry_free() if someone else holds one as well. 1441 */ 1442 LLE_WUNLOCK(ln); 1443 IF_AFDATA_LOCK(ifp); 1444 LLE_WLOCK(ln); 1445 1446 lltable_free_entry(LLTABLE(ifp), ln); 1447 1448 IF_AFDATA_UNLOCK(ifp); 1449 } 1450 1451 /* 1452 * Upper-layer reachability hint for Neighbor Unreachability Detection. 1453 * 1454 * XXX cost-effective methods? 1455 */ 1456 void 1457 arp_nud_hint(struct rtentry *rt) 1458 { 1459 struct llentry *ln; 1460 struct ifnet *ifp; 1461 1462 if (rt == NULL) 1463 return; 1464 1465 ifp = rt->rt_ifp; 1466 ln = arplookup(ifp, NULL, rt_getkey(rt), 1); 1467 nd_nud_hint(ln); 1468 } 1469 1470 TAILQ_HEAD(dadq_head, dadq); 1471 struct dadq { 1472 TAILQ_ENTRY(dadq) dad_list; 1473 struct ifaddr *dad_ifa; 1474 int dad_count; /* max ARP to send */ 1475 int dad_arp_tcount; /* # of trials to send ARP */ 1476 int dad_arp_ocount; /* ARP sent so far */ 1477 int dad_arp_announce; /* max ARP announcements */ 1478 int dad_arp_acount; /* # of announcements */ 1479 struct callout dad_timer_ch; 1480 }; 1481 1482 static struct dadq_head dadq; 1483 static int dad_maxtry = 15; /* max # of *tries* to transmit DAD packet */ 1484 static kmutex_t arp_dad_lock; 1485 1486 static void 1487 arp_dad_init(void) 1488 { 1489 1490 TAILQ_INIT(&dadq); 1491 mutex_init(&arp_dad_lock, MUTEX_DEFAULT, IPL_NONE); 1492 } 1493 1494 static struct dadq * 1495 arp_dad_find(struct ifaddr *ifa) 1496 { 1497 struct dadq *dp; 1498 1499 KASSERT(mutex_owned(&arp_dad_lock)); 1500 1501 TAILQ_FOREACH(dp, &dadq, dad_list) { 1502 if (dp->dad_ifa == ifa) 1503 return dp; 1504 } 1505 return NULL; 1506 } 1507 1508 static void 1509 arp_dad_starttimer(struct dadq *dp, int ticks) 1510 { 1511 1512 callout_reset(&dp->dad_timer_ch, ticks, 1513 (void (*)(void *))arp_dad_timer, dp); 1514 } 1515 1516 static void 1517 arp_dad_stoptimer(struct dadq *dp) 1518 { 1519 1520 KASSERT(mutex_owned(&arp_dad_lock)); 1521 1522 TAILQ_REMOVE(&dadq, dp, dad_list); 1523 /* Tell the timer that dp is being destroyed. */ 1524 dp->dad_ifa = NULL; 1525 callout_halt(&dp->dad_timer_ch, &arp_dad_lock); 1526 } 1527 1528 static void 1529 arp_dad_destroytimer(struct dadq *dp) 1530 { 1531 1532 callout_destroy(&dp->dad_timer_ch); 1533 KASSERT(dp->dad_ifa == NULL); 1534 kmem_intr_free(dp, sizeof(*dp)); 1535 } 1536 1537 static void 1538 arp_dad_output(struct dadq *dp, struct ifaddr *ifa) 1539 { 1540 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1541 struct ifnet *ifp = ifa->ifa_ifp; 1542 struct in_addr sip; 1543 1544 dp->dad_arp_tcount++; 1545 if ((ifp->if_flags & IFF_UP) == 0) 1546 return; 1547 if ((ifp->if_flags & IFF_RUNNING) == 0) 1548 return; 1549 1550 dp->dad_arp_tcount = 0; 1551 dp->dad_arp_ocount++; 1552 1553 memset(&sip, 0, sizeof(sip)); 1554 arprequest(ifa->ifa_ifp, &sip, &ia->ia_addr.sin_addr, 1555 CLLADDR(ifa->ifa_ifp->if_sadl), NULL); 1556 } 1557 1558 /* 1559 * Start Duplicate Address Detection (DAD) for specified interface address. 1560 */ 1561 static void 1562 arp_dad_start(struct ifaddr *ifa) 1563 { 1564 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1565 struct dadq *dp; 1566 char ipbuf[INET_ADDRSTRLEN]; 1567 1568 /* 1569 * If we don't need DAD, don't do it. 1570 * - DAD is disabled 1571 */ 1572 if (!(ia->ia4_flags & IN_IFF_TENTATIVE)) { 1573 log(LOG_DEBUG, 1574 "%s: called with non-tentative address %s(%s)\n", __func__, 1575 IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1576 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1577 return; 1578 } 1579 if (!ip_dad_enabled()) { 1580 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1581 rt_addrmsg(RTM_NEWADDR, ifa); 1582 arpannounce1(ifa); 1583 return; 1584 } 1585 KASSERT(ifa->ifa_ifp != NULL); 1586 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) 1587 return; 1588 1589 dp = kmem_intr_alloc(sizeof(*dp), KM_NOSLEEP); 1590 1591 mutex_enter(&arp_dad_lock); 1592 if (arp_dad_find(ifa) != NULL) { 1593 mutex_exit(&arp_dad_lock); 1594 /* DAD already in progress */ 1595 if (dp != NULL) 1596 kmem_intr_free(dp, sizeof(*dp)); 1597 return; 1598 } 1599 1600 if (dp == NULL) { 1601 mutex_exit(&arp_dad_lock); 1602 log(LOG_ERR, "%s: memory allocation failed for %s(%s)\n", 1603 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1604 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1605 return; 1606 } 1607 1608 /* 1609 * Send ARP packet for DAD, ip_dad_count times. 1610 * Note that we must delay the first transmission. 1611 */ 1612 callout_init(&dp->dad_timer_ch, CALLOUT_MPSAFE); 1613 dp->dad_ifa = ifa; 1614 ifaref(ifa); /* just for safety */ 1615 dp->dad_count = ip_dad_count; 1616 dp->dad_arp_announce = 0; /* Will be set when starting to announce */ 1617 dp->dad_arp_acount = dp->dad_arp_ocount = dp->dad_arp_tcount = 0; 1618 TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list); 1619 1620 ARPLOG(LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1621 ARPLOGADDR(&ia->ia_addr.sin_addr)); 1622 1623 arp_dad_starttimer(dp, cprng_fast32() % (PROBE_WAIT * hz)); 1624 1625 mutex_exit(&arp_dad_lock); 1626 } 1627 1628 /* 1629 * terminate DAD unconditionally. used for address removals. 1630 */ 1631 static void 1632 arp_dad_stop(struct ifaddr *ifa) 1633 { 1634 struct dadq *dp; 1635 1636 mutex_enter(&arp_dad_lock); 1637 dp = arp_dad_find(ifa); 1638 if (dp == NULL) { 1639 mutex_exit(&arp_dad_lock); 1640 /* DAD wasn't started yet */ 1641 return; 1642 } 1643 1644 arp_dad_stoptimer(dp); 1645 1646 mutex_exit(&arp_dad_lock); 1647 1648 arp_dad_destroytimer(dp); 1649 ifafree(ifa); 1650 } 1651 1652 static void 1653 arp_dad_timer(struct dadq *dp) 1654 { 1655 struct ifaddr *ifa; 1656 struct in_ifaddr *ia; 1657 char ipbuf[INET_ADDRSTRLEN]; 1658 bool need_free = false; 1659 1660 KERNEL_LOCK_UNLESS_NET_MPSAFE(); 1661 mutex_enter(&arp_dad_lock); 1662 1663 ifa = dp->dad_ifa; 1664 if (ifa == NULL) { 1665 /* dp is being destroyed by someone. Do nothing. */ 1666 goto done; 1667 } 1668 1669 ia = (struct in_ifaddr *)ifa; 1670 if (ia->ia4_flags & IN_IFF_DUPLICATED) { 1671 log(LOG_ERR, "%s: called with duplicate address %s(%s)\n", 1672 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1673 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1674 goto done; 1675 } 1676 if ((ia->ia4_flags & IN_IFF_TENTATIVE) == 0 && dp->dad_arp_acount == 0) 1677 { 1678 log(LOG_ERR, "%s: called with non-tentative address %s(%s)\n", 1679 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1680 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1681 goto done; 1682 } 1683 1684 /* timeouted with IFF_{RUNNING,UP} check */ 1685 if (dp->dad_arp_tcount > dad_maxtry) { 1686 ARPLOG(LOG_INFO, "%s: could not run DAD, driver problem?\n", 1687 if_name(ifa->ifa_ifp)); 1688 1689 arp_dad_stoptimer(dp); 1690 need_free = true; 1691 goto done; 1692 } 1693 1694 /* Need more checks? */ 1695 if (dp->dad_arp_ocount < dp->dad_count) { 1696 int adelay; 1697 1698 /* 1699 * We have more ARP to go. Send ARP packet for DAD. 1700 */ 1701 arp_dad_output(dp, ifa); 1702 if (dp->dad_arp_ocount < dp->dad_count) 1703 adelay = (PROBE_MIN * hz) + 1704 (cprng_fast32() % 1705 ((PROBE_MAX * hz) - (PROBE_MIN * hz))); 1706 else 1707 adelay = ANNOUNCE_WAIT * hz; 1708 arp_dad_starttimer(dp, adelay); 1709 goto done; 1710 } else if (dp->dad_arp_acount == 0) { 1711 /* 1712 * We are done with DAD. 1713 * No duplicate address found. 1714 */ 1715 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1716 rt_addrmsg(RTM_NEWADDR, ifa); 1717 ARPLOG(LOG_DEBUG, 1718 "%s: DAD complete for %s - no duplicates found\n", 1719 if_name(ifa->ifa_ifp), ARPLOGADDR(&ia->ia_addr.sin_addr)); 1720 dp->dad_arp_announce = ANNOUNCE_NUM; 1721 goto announce; 1722 } else if (dp->dad_arp_acount < dp->dad_arp_announce) { 1723 announce: 1724 /* 1725 * Announce the address. 1726 */ 1727 arpannounce1(ifa); 1728 dp->dad_arp_acount++; 1729 if (dp->dad_arp_acount < dp->dad_arp_announce) { 1730 arp_dad_starttimer(dp, ANNOUNCE_INTERVAL * hz); 1731 goto done; 1732 } 1733 ARPLOG(LOG_DEBUG, 1734 "%s: ARP announcement complete for %s\n", 1735 if_name(ifa->ifa_ifp), ARPLOGADDR(&ia->ia_addr.sin_addr)); 1736 } 1737 1738 arp_dad_stoptimer(dp); 1739 need_free = true; 1740 done: 1741 mutex_exit(&arp_dad_lock); 1742 1743 if (need_free) { 1744 arp_dad_destroytimer(dp); 1745 KASSERT(ifa != NULL); 1746 ifafree(ifa); 1747 } 1748 1749 KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 1750 } 1751 1752 static void 1753 arp_dad_duplicated(struct ifaddr *ifa, const struct sockaddr_dl *from) 1754 { 1755 struct in_ifaddr *ia = ifatoia(ifa); 1756 struct ifnet *ifp = ifa->ifa_ifp; 1757 char ipbuf[INET_ADDRSTRLEN], llabuf[LLA_ADDRSTRLEN]; 1758 const char *iastr, *llastr; 1759 1760 iastr = IN_PRINT(ipbuf, &ia->ia_addr.sin_addr); 1761 if (__predict_false(from == NULL)) 1762 llastr = NULL; 1763 else 1764 llastr = lla_snprintf(llabuf, sizeof(llabuf), 1765 CLLADDR(from), from->sdl_alen); 1766 1767 if (ia->ia4_flags & (IN_IFF_TENTATIVE|IN_IFF_DUPLICATED)) { 1768 log(LOG_ERR, 1769 "%s: DAD duplicate address %s from %s\n", 1770 if_name(ifp), iastr, llastr); 1771 } else if (ia->ia_dad_defended == 0 || 1772 ia->ia_dad_defended < time_uptime - DEFEND_INTERVAL) { 1773 ia->ia_dad_defended = time_uptime; 1774 arpannounce1(ifa); 1775 log(LOG_ERR, 1776 "%s: DAD defended address %s from %s\n", 1777 if_name(ifp), iastr, llastr); 1778 return; 1779 } else { 1780 /* If DAD is disabled, just report the duplicate. */ 1781 if (!ip_dad_enabled()) { 1782 log(LOG_ERR, 1783 "%s: DAD ignoring duplicate address %s from %s\n", 1784 if_name(ifp), iastr, llastr); 1785 return; 1786 } 1787 log(LOG_ERR, 1788 "%s: DAD defence failed for %s from %s\n", 1789 if_name(ifp), iastr, llastr); 1790 } 1791 1792 arp_dad_stop(ifa); 1793 1794 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1795 if ((ia->ia4_flags & IN_IFF_DUPLICATED) == 0) { 1796 ia->ia4_flags |= IN_IFF_DUPLICATED; 1797 /* Inform the routing socket of the duplicate address */ 1798 rt_addrmsg_src(RTM_NEWADDR, ifa, (const struct sockaddr *)from); 1799 } 1800 } 1801 1802 /* 1803 * Called from 10 Mb/s Ethernet interrupt handlers 1804 * when ether packet type ETHERTYPE_REVARP 1805 * is received. Common length and type checks are done here, 1806 * then the protocol-specific routine is called. 1807 */ 1808 void 1809 revarpinput(struct mbuf *m) 1810 { 1811 struct arphdr *ar; 1812 int arplen; 1813 1814 arplen = sizeof(struct arphdr); 1815 if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL) 1816 return; 1817 ar = mtod(m, struct arphdr *); 1818 1819 if (ntohs(ar->ar_hrd) == ARPHRD_IEEE1394) { 1820 goto out; 1821 } 1822 1823 arplen = sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln); 1824 if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL) 1825 return; 1826 ar = mtod(m, struct arphdr *); 1827 1828 switch (ntohs(ar->ar_pro)) { 1829 case ETHERTYPE_IP: 1830 case ETHERTYPE_IPTRAILERS: 1831 in_revarpinput(m); 1832 return; 1833 1834 default: 1835 break; 1836 } 1837 1838 out: 1839 m_freem(m); 1840 } 1841 1842 /* 1843 * RARP for Internet protocols on 10 Mb/s Ethernet. 1844 * Algorithm is that given in RFC 903. 1845 * We are only using for bootstrap purposes to get an ip address for one of 1846 * our interfaces. Thus we support no user-interface. 1847 * 1848 * Since the contents of the RARP reply are specific to the interface that 1849 * sent the request, this code must ensure that they are properly associated. 1850 * 1851 * Note: also supports ARP via RARP packets, per the RFC. 1852 */ 1853 void 1854 in_revarpinput(struct mbuf *m) 1855 { 1856 struct arphdr *ah; 1857 void *tha; 1858 int op; 1859 struct ifnet *rcvif; 1860 int s; 1861 1862 ah = mtod(m, struct arphdr *); 1863 op = ntohs(ah->ar_op); 1864 1865 rcvif = m_get_rcvif(m, &s); 1866 if (__predict_false(rcvif == NULL)) 1867 goto out; 1868 if (rcvif->if_flags & IFF_NOARP) 1869 goto out; 1870 1871 switch (rcvif->if_type) { 1872 case IFT_IEEE1394: 1873 /* ARP without target hardware address is not supported */ 1874 goto out; 1875 default: 1876 break; 1877 } 1878 1879 switch (op) { 1880 case ARPOP_REQUEST: 1881 case ARPOP_REPLY: /* per RFC */ 1882 m_put_rcvif(rcvif, &s); 1883 in_arpinput(m); 1884 return; 1885 case ARPOP_REVREPLY: 1886 break; 1887 case ARPOP_REVREQUEST: /* handled by rarpd(8) */ 1888 default: 1889 goto out; 1890 } 1891 if (!revarp_in_progress) 1892 goto out; 1893 if (rcvif != myip_ifp) /* !same interface */ 1894 goto out; 1895 if (myip_initialized) 1896 goto wake; 1897 tha = ar_tha(ah); 1898 if (tha == NULL) 1899 goto out; 1900 if (ah->ar_pln != sizeof(struct in_addr)) 1901 goto out; 1902 if (ah->ar_hln != rcvif->if_sadl->sdl_alen) 1903 goto out; 1904 if (memcmp(tha, CLLADDR(rcvif->if_sadl), rcvif->if_sadl->sdl_alen)) 1905 goto out; 1906 memcpy(&srv_ip, ar_spa(ah), sizeof(srv_ip)); 1907 memcpy(&myip, ar_tpa(ah), sizeof(myip)); 1908 myip_initialized = 1; 1909 wake: /* Do wakeup every time in case it was missed. */ 1910 wakeup((void *)&myip); 1911 1912 out: 1913 m_put_rcvif(rcvif, &s); 1914 m_freem(m); 1915 } 1916 1917 /* 1918 * Send a RARP request for the ip address of the specified interface. 1919 * The request should be RFC 903-compliant. 1920 */ 1921 static void 1922 revarprequest(struct ifnet *ifp) 1923 { 1924 struct sockaddr sa; 1925 struct mbuf *m; 1926 struct arphdr *ah; 1927 void *tha; 1928 1929 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 1930 return; 1931 MCLAIM(m, &arpdomain.dom_mowner); 1932 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) + 1933 2*ifp->if_addrlen; 1934 m->m_pkthdr.len = m->m_len; 1935 m_align(m, m->m_len); 1936 ah = mtod(m, struct arphdr *); 1937 memset(ah, 0, m->m_len); 1938 ah->ar_pro = htons(ETHERTYPE_IP); 1939 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 1940 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 1941 ah->ar_op = htons(ARPOP_REVREQUEST); 1942 1943 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1944 tha = ar_tha(ah); 1945 if (tha == NULL) { 1946 m_free(m); 1947 return; 1948 } 1949 memcpy(tha, CLLADDR(ifp->if_sadl), ah->ar_hln); 1950 1951 sa.sa_family = AF_ARP; 1952 sa.sa_len = 2; 1953 m->m_flags |= M_BCAST; 1954 1955 if_output_lock(ifp, ifp, m, &sa, NULL); 1956 } 1957 1958 /* 1959 * RARP for the ip address of the specified interface, but also 1960 * save the ip address of the server that sent the answer. 1961 * Timeout if no response is received. 1962 */ 1963 int 1964 revarpwhoarewe(struct ifnet *ifp, struct in_addr *serv_in, 1965 struct in_addr *clnt_in) 1966 { 1967 int result, count = 20; 1968 1969 myip_initialized = 0; 1970 myip_ifp = ifp; 1971 1972 revarp_in_progress = 1; 1973 while (count--) { 1974 revarprequest(ifp); 1975 result = tsleep((void *)&myip, PSOCK, "revarp", hz/2); 1976 if (result != EWOULDBLOCK) 1977 break; 1978 } 1979 revarp_in_progress = 0; 1980 1981 if (!myip_initialized) 1982 return ENETUNREACH; 1983 1984 memcpy(serv_in, &srv_ip, sizeof(*serv_in)); 1985 memcpy(clnt_in, &myip, sizeof(*clnt_in)); 1986 return 0; 1987 } 1988 1989 void 1990 arp_stat_add(int type, uint64_t count) 1991 { 1992 ARP_STATADD(type, count); 1993 } 1994 1995 static int 1996 sysctl_net_inet_arp_stats(SYSCTLFN_ARGS) 1997 { 1998 1999 return NETSTAT_SYSCTL(arpstat_percpu, ARP_NSTATS); 2000 } 2001 2002 static void 2003 sysctl_net_inet_arp_setup(struct sysctllog **clog) 2004 { 2005 const struct sysctlnode *node; 2006 2007 sysctl_createv(clog, 0, NULL, NULL, 2008 CTLFLAG_PERMANENT, 2009 CTLTYPE_NODE, "inet", NULL, 2010 NULL, 0, NULL, 0, 2011 CTL_NET, PF_INET, CTL_EOL); 2012 sysctl_createv(clog, 0, NULL, &node, 2013 CTLFLAG_PERMANENT, 2014 CTLTYPE_NODE, "arp", 2015 SYSCTL_DESCR("Address Resolution Protocol"), 2016 NULL, 0, NULL, 0, 2017 CTL_NET, PF_INET, CTL_CREATE, CTL_EOL); 2018 2019 sysctl_createv(clog, 0, NULL, NULL, 2020 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2021 CTLTYPE_INT, "nd_delay", 2022 SYSCTL_DESCR("First probe delay time"), 2023 NULL, 0, &arp_nd_domain.nd_delay, 0, 2024 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2025 sysctl_createv(clog, 0, NULL, NULL, 2026 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2027 CTLTYPE_INT, "nd_bmaxtries", 2028 SYSCTL_DESCR("Number of broadcast discovery attempts"), 2029 NULL, 0, &arp_nd_domain.nd_mmaxtries, 0, 2030 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2031 sysctl_createv(clog, 0, NULL, NULL, 2032 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2033 CTLTYPE_INT, "nd_umaxtries", 2034 SYSCTL_DESCR("Number of unicast discovery attempts"), 2035 NULL, 0, &arp_nd_domain.nd_umaxtries, 0, 2036 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2037 sysctl_createv(clog, 0, NULL, NULL, 2038 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2039 CTLTYPE_INT, "nd_reachable", 2040 SYSCTL_DESCR("Reachable time"), 2041 NULL, 0, &arp_reachable, 0, 2042 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2043 sysctl_createv(clog, 0, NULL, NULL, 2044 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2045 CTLTYPE_INT, "nd_retrans", 2046 SYSCTL_DESCR("Retransmission time"), 2047 NULL, 0, &arp_retrans, 0, 2048 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2049 sysctl_createv(clog, 0, NULL, NULL, 2050 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2051 CTLTYPE_INT, "nd_nud", 2052 SYSCTL_DESCR("Perform neighbour unreachability detection"), 2053 NULL, 0, &arp_perform_nud, 0, 2054 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2055 sysctl_createv(clog, 0, NULL, NULL, 2056 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2057 CTLTYPE_INT, "nd_maxnudhint", 2058 SYSCTL_DESCR("Maximum neighbor unreachable hint count"), 2059 NULL, 0, &arp_nd_domain.nd_maxnudhint, 0, 2060 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2061 sysctl_createv(clog, 0, NULL, NULL, 2062 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2063 CTLTYPE_INT, "maxqueuelen", 2064 SYSCTL_DESCR("max packet queue len for a unresolved ARP"), 2065 NULL, 1, &arp_nd_domain.nd_maxqueuelen, 0, 2066 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2067 2068 sysctl_createv(clog, 0, NULL, NULL, 2069 CTLFLAG_PERMANENT, 2070 CTLTYPE_STRUCT, "stats", 2071 SYSCTL_DESCR("ARP statistics"), 2072 sysctl_net_inet_arp_stats, 0, NULL, 0, 2073 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2074 2075 sysctl_createv(clog, 0, NULL, NULL, 2076 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2077 CTLTYPE_INT, "log_movements", 2078 SYSCTL_DESCR("log ARP replies from MACs different than" 2079 " the one in the cache"), 2080 NULL, 0, &log_movements, 0, 2081 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2082 2083 sysctl_createv(clog, 0, NULL, NULL, 2084 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2085 CTLTYPE_INT, "log_permanent_modify", 2086 SYSCTL_DESCR("log ARP replies from MACs different than" 2087 " the one in the permanent arp entry"), 2088 NULL, 0, &log_permanent_modify, 0, 2089 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2090 2091 sysctl_createv(clog, 0, NULL, NULL, 2092 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2093 CTLTYPE_INT, "log_wrong_iface", 2094 SYSCTL_DESCR("log ARP packets arriving on the wrong" 2095 " interface"), 2096 NULL, 0, &log_wrong_iface, 0, 2097 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2098 2099 sysctl_createv(clog, 0, NULL, NULL, 2100 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2101 CTLTYPE_INT, "debug", 2102 SYSCTL_DESCR("Enable ARP DAD debug output"), 2103 NULL, 0, &arp_debug, 0, 2104 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2105 } 2106 2107 #endif /* INET */ 2108