1 /* $NetBSD: if_arp.c,v 1.321 2026/07/23 21:49:19 riastradh 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 1.321 2026/07/23 21:49:19 riastradh 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_gctimer = 24*60*60, /* stale neighbor GC timer duration */ 161 .nd_nud_enabled = arp_nud_enabled, 162 .nd_reachable = arp_llinfo_reachable, 163 .nd_retrans = arp_llinfo_retrans, 164 .nd_holdsrc = arp_llinfo_holdsrc, 165 .nd_output = arp_llinfo_output, 166 .nd_missed = arp_llinfo_missed, 167 .nd_free = arp_free, 168 }; 169 170 int ip_dad_count = PROBE_NUM; 171 #ifdef ARP_DEBUG 172 int arp_debug = 1; 173 #else 174 int arp_debug = 0; 175 #endif 176 177 static void arp_init(void); 178 static void arp_dad_init(void); 179 180 static void arprequest(struct ifnet *, 181 const struct in_addr *, const struct in_addr *, 182 const uint8_t *, const uint8_t *); 183 static void arpannounce1(struct ifaddr *); 184 static struct sockaddr *arp_setgate(struct rtentry *, struct sockaddr *, 185 const struct sockaddr *); 186 static struct llentry *arpcreate(struct ifnet *, 187 const struct in_addr *, const struct sockaddr *, int); 188 static void in_arpinput(struct mbuf *); 189 static void in_revarpinput(struct mbuf *); 190 static void revarprequest(struct ifnet *); 191 192 static void arp_drainstub(void); 193 194 struct dadq; 195 static void arp_dad_timer(struct dadq *); 196 static void arp_dad_start(struct ifaddr *); 197 static void arp_dad_stop(struct ifaddr *); 198 static void arp_dad_duplicated(struct ifaddr *, const struct sockaddr_dl *); 199 200 #define ARP_MAXQLEN 50 201 pktqueue_t * arp_pktq __read_mostly; 202 203 static int useloopback = 1; /* use loopback interface for local traffic */ 204 205 static percpu_t *arpstat_percpu; 206 207 #define ARP_STAT_GETREF() _NET_STAT_GETREF(arpstat_percpu) 208 #define ARP_STAT_PUTREF() _NET_STAT_PUTREF(arpstat_percpu) 209 210 #define ARP_STATINC(x) _NET_STATINC(arpstat_percpu, x) 211 #define ARP_STATADD(x, v) _NET_STATADD(arpstat_percpu, x, v) 212 213 /* revarp state */ 214 static struct in_addr myip, srv_ip; 215 static int myip_initialized = 0; 216 static int revarp_in_progress = 0; 217 static struct ifnet *myip_ifp = NULL; 218 219 static int arp_drainwanted; 220 221 static int log_movements = 0; 222 static int log_permanent_modify = 1; 223 static int log_wrong_iface = 1; 224 225 DOMAIN_DEFINE(arpdomain); /* forward declare and add to link set */ 226 227 static void 228 arp_fasttimo(void) 229 { 230 if (arp_drainwanted) { 231 arp_drain(); 232 arp_drainwanted = 0; 233 } 234 } 235 236 static const struct protosw arpsw[] = { 237 { 238 .pr_type = 0, 239 .pr_domain = &arpdomain, 240 .pr_protocol = 0, 241 .pr_flags = 0, 242 .pr_input = 0, 243 .pr_ctlinput = 0, 244 .pr_ctloutput = 0, 245 .pr_usrreqs = 0, 246 .pr_init = arp_init, 247 .pr_fasttimo = arp_fasttimo, 248 .pr_slowtimo = 0, 249 .pr_drain = arp_drainstub, 250 } 251 }; 252 253 struct domain arpdomain = { 254 .dom_family = PF_ARP, 255 .dom_name = "arp", 256 .dom_protosw = arpsw, 257 .dom_protoswNPROTOSW = &arpsw[__arraycount(arpsw)], 258 #ifdef MBUFTRACE 259 .dom_mowner = MOWNER_INIT("internet", "arp"), 260 #endif 261 }; 262 263 static void sysctl_net_inet_arp_setup(struct sysctllog **); 264 265 void 266 arp_init(void) 267 { 268 269 arp_pktq = pktq_create(ARP_MAXQLEN, arpintr, NULL); 270 KASSERT(arp_pktq != NULL); 271 272 sysctl_net_inet_arp_setup(NULL); 273 arpstat_percpu = percpu_alloc(sizeof(uint64_t) * ARP_NSTATS); 274 275 #ifdef MBUFTRACE 276 MOWNER_ATTACH(&arpdomain.dom_mowner); 277 #endif 278 279 nd_attach_domain(&arp_nd_domain); 280 arp_dad_init(); 281 } 282 283 static void 284 arp_drainstub(void) 285 { 286 arp_drainwanted = 1; 287 } 288 289 /* 290 * ARP protocol drain routine. Called when memory is in short supply. 291 * Called at splvm(); don't acquire softnet_lock as can be called from 292 * hardware interrupt handlers. 293 */ 294 void 295 arp_drain(void) 296 { 297 298 lltable_drain(AF_INET); 299 } 300 301 /* 302 * We set the gateway for RTF_CLONING routes to a "prototype" 303 * link-layer sockaddr whose interface type (if_type) and interface 304 * index (if_index) fields are prepared. 305 */ 306 static struct sockaddr * 307 arp_setgate(struct rtentry *rt, struct sockaddr *gate, 308 const struct sockaddr *netmask) 309 { 310 const struct ifnet *ifp = rt->rt_ifp; 311 uint8_t namelen = strlen(ifp->if_xname); 312 uint8_t addrlen = ifp->if_addrlen; 313 314 /* 315 * XXX: If this is a manually added route to interface 316 * such as older version of routed or gated might provide, 317 * restore cloning bit. 318 */ 319 if ((rt->rt_flags & RTF_HOST) == 0 && netmask != NULL && 320 satocsin(netmask)->sin_addr.s_addr != 0xffffffff) 321 rt->rt_flags |= RTF_CONNECTED; 322 323 if ((rt->rt_flags & (RTF_CONNECTED | RTF_LOCAL))) { 324 union { 325 struct sockaddr sa; 326 struct sockaddr_storage ss; 327 struct sockaddr_dl sdl; 328 } u; 329 /* 330 * Case 1: This route should come from a route to iface. 331 */ 332 sockaddr_dl_init(&u.sdl, sizeof(u.ss), 333 ifp->if_index, ifp->if_type, NULL, namelen, NULL, addrlen); 334 rt_setgate(rt, &u.sa); 335 gate = rt->rt_gateway; 336 } 337 return gate; 338 } 339 340 /* 341 * Parallel to llc_rtrequest. 342 */ 343 void 344 arp_rtrequest(int req, struct rtentry *rt, const struct rt_addrinfo *info) 345 { 346 struct sockaddr *gate = rt->rt_gateway; 347 struct in_ifaddr *ia; 348 struct ifaddr *ifa; 349 struct ifnet *ifp = rt->rt_ifp; 350 int bound; 351 int s; 352 353 if (req == RTM_LLINFO_UPD) { 354 if ((ifa = info->rti_ifa) != NULL) 355 arpannounce1(ifa); 356 return; 357 } 358 359 if ((rt->rt_flags & RTF_GATEWAY) != 0) { 360 if (req != RTM_ADD) 361 return; 362 363 /* 364 * linklayers with particular link MTU limitation. 365 */ 366 switch(ifp->if_type) { 367 #if NARCNET > 0 368 case IFT_ARCNET: 369 { 370 int arcipifmtu; 371 372 if (ifp->if_flags & IFF_LINK0) 373 arcipifmtu = arc_ipmtu; 374 else 375 arcipifmtu = ARCMTU; 376 if (ifp->if_mtu > arcipifmtu) 377 rt->rt_rmx.rmx_mtu = arcipifmtu; 378 break; 379 } 380 #endif 381 } 382 return; 383 } 384 385 switch (req) { 386 case RTM_SETGATE: 387 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 388 break; 389 case RTM_ADD: 390 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 391 if (gate == NULL) { 392 log(LOG_ERR, "%s: arp_setgate failed\n", __func__); 393 break; 394 } 395 if ((rt->rt_flags & RTF_CONNECTED) || 396 (rt->rt_flags & RTF_LOCAL)) { 397 /* 398 * linklayers with particular link MTU limitation. 399 */ 400 switch (ifp->if_type) { 401 #if NARCNET > 0 402 case IFT_ARCNET: 403 { 404 int arcipifmtu; 405 if (ifp->if_flags & IFF_LINK0) 406 arcipifmtu = arc_ipmtu; 407 else 408 arcipifmtu = ARCMTU; 409 410 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 411 (rt->rt_rmx.rmx_mtu > arcipifmtu || 412 (rt->rt_rmx.rmx_mtu == 0 && 413 ifp->if_mtu > arcipifmtu))) 414 rt->rt_rmx.rmx_mtu = arcipifmtu; 415 break; 416 } 417 #endif 418 } 419 if (rt->rt_flags & RTF_CONNECTED) 420 break; 421 } 422 423 bound = curlwp_bind(); 424 /* Announce a new entry if requested. */ 425 if (rt->rt_flags & RTF_ANNOUNCE) { 426 struct psref psref; 427 ia = in_get_ia_on_iface_psref( 428 satocsin(rt_getkey(rt))->sin_addr, ifp, &psref); 429 if (ia != NULL) { 430 arpannounce(ifp, &ia->ia_ifa, 431 CLLADDR(satocsdl(gate))); 432 ia4_release(ia, &psref); 433 } 434 } 435 436 if (gate->sa_family != AF_LINK || 437 gate->sa_len < sockaddr_dl_measure(0, ifp->if_addrlen)) { 438 log(LOG_DEBUG, "%s: bad gateway value\n", __func__); 439 goto out; 440 } 441 442 satosdl(gate)->sdl_type = ifp->if_type; 443 satosdl(gate)->sdl_index = ifp->if_index; 444 445 /* 446 * If the route is for a broadcast address mark it as such. 447 * This way we can avoid an expensive call to in_broadcast() 448 * in ip_output() most of the time (because the route passed 449 * to ip_output() is almost always a host route). 450 */ 451 if (rt->rt_flags & RTF_HOST && 452 !(rt->rt_flags & RTF_BROADCAST) && 453 in_broadcast(satocsin(rt_getkey(rt))->sin_addr, rt->rt_ifp)) 454 rt->rt_flags |= RTF_BROADCAST; 455 /* There is little point in resolving the broadcast address */ 456 if (rt->rt_flags & RTF_BROADCAST) 457 goto out; 458 459 /* 460 * When called from rt_ifa_addlocal, we cannot depend on that 461 * the address (rt_getkey(rt)) exits in the address list of the 462 * interface. So check RTF_LOCAL instead. 463 */ 464 if (rt->rt_flags & RTF_LOCAL) { 465 if (useloopback) { 466 rt->rt_ifp = lo0ifp; 467 rt->rt_rmx.rmx_mtu = 0; 468 } 469 goto out; 470 } 471 472 s = pserialize_read_enter(); 473 ia = in_get_ia_on_iface(satocsin(rt_getkey(rt))->sin_addr, ifp); 474 if (ia == NULL) { 475 pserialize_read_exit(s); 476 goto out; 477 } 478 479 if (useloopback) { 480 rt->rt_ifp = lo0ifp; 481 rt->rt_rmx.rmx_mtu = 0; 482 } 483 rt->rt_flags |= RTF_LOCAL; 484 485 if (ISSET(info->rti_flags, RTF_DONTCHANGEIFA)) { 486 pserialize_read_exit(s); 487 goto out; 488 } 489 /* 490 * make sure to set rt->rt_ifa to the interface 491 * address we are using, otherwise we will have trouble 492 * with source address selection. 493 */ 494 ifa = &ia->ia_ifa; 495 if (ifa != rt->rt_ifa) 496 /* Assume it doesn't sleep */ 497 rt_replace_ifa(rt, ifa); 498 pserialize_read_exit(s); 499 out: 500 curlwp_bindx(bound); 501 break; 502 } 503 } 504 505 /* 506 * Broadcast an ARP request. Caller specifies: 507 * - arp header source ip address 508 * - arp header target ip address 509 * - arp header source ethernet address 510 */ 511 static void 512 arprequest(struct ifnet *ifp, 513 const struct in_addr *sip, const struct in_addr *tip, 514 const uint8_t *saddr, const uint8_t *taddr) 515 { 516 struct mbuf *m; 517 struct arphdr *ah; 518 struct sockaddr sa; 519 net_stat_ref_t arps; 520 521 KASSERT(sip != NULL); 522 KASSERT(tip != NULL); 523 KASSERT(saddr != NULL); 524 525 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 526 return; 527 MCLAIM(m, &arpdomain.dom_mowner); 528 switch (ifp->if_type) { 529 case IFT_IEEE1394: 530 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 531 ifp->if_addrlen; 532 break; 533 default: 534 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 535 2 * ifp->if_addrlen; 536 break; 537 } 538 m->m_pkthdr.len = m->m_len; 539 m_align(m, m->m_len); 540 ah = mtod(m, struct arphdr *); 541 memset(ah, 0, m->m_len); 542 switch (ifp->if_type) { 543 case IFT_IEEE1394: /* RFC2734 */ 544 /* fill it now for ar_tpa computation */ 545 ah->ar_hrd = htons(ARPHRD_IEEE1394); 546 break; 547 default: 548 /* ifp->if_output will fill ar_hrd */ 549 break; 550 } 551 ah->ar_pro = htons(ETHERTYPE_IP); 552 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 553 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 554 ah->ar_op = htons(ARPOP_REQUEST); 555 memcpy(ar_sha(ah), saddr, ah->ar_hln); 556 if (taddr == NULL) 557 m->m_flags |= M_BCAST; 558 else 559 memcpy(ar_tha(ah), taddr, ah->ar_hln); 560 memcpy(ar_spa(ah), sip, ah->ar_pln); 561 memcpy(ar_tpa(ah), tip, ah->ar_pln); 562 sa.sa_family = AF_ARP; 563 sa.sa_len = 2; 564 arps = ARP_STAT_GETREF(); 565 _NET_STATINC_REF(arps, ARP_STAT_SNDTOTAL); 566 _NET_STATINC_REF(arps, ARP_STAT_SENDREQUEST); 567 ARP_STAT_PUTREF(); 568 if_output_lock(ifp, ifp, m, &sa, NULL); 569 } 570 571 void 572 arpannounce(struct ifnet *ifp, struct ifaddr *ifa, const uint8_t *enaddr) 573 { 574 struct in_ifaddr *ia = ifatoia(ifa); 575 struct in_addr *ip = &IA_SIN(ifa)->sin_addr; 576 577 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) { 578 ARPLOG(LOG_DEBUG, "%s not ready\n", ARPLOGADDR(ip)); 579 return; 580 } 581 arprequest(ifp, ip, ip, enaddr, NULL); 582 } 583 584 static void 585 arpannounce1(struct ifaddr *ifa) 586 { 587 588 arpannounce(ifa->ifa_ifp, ifa, CLLADDR(ifa->ifa_ifp->if_sadl)); 589 } 590 591 /* 592 * Resolve an IP address into an ethernet address. If success, desten is 593 * filled in. If there is no entry in arptab, set one up and broadcast a 594 * request for the IP address. Hold onto this mbuf and resend it once the 595 * address is finally resolved. 596 * 597 * A return value of 0 indicates that desten has been filled in and the packet 598 * should be sent normally; a return value of EWOULDBLOCK indicates that the 599 * packet has been held pending resolution. Any other value indicates an 600 * error. 601 */ 602 int 603 arpresolve(struct ifnet *ifp, const struct rtentry *rt, struct mbuf *m, 604 const struct sockaddr *dst, void *desten, size_t destlen) 605 { 606 struct llentry *la; 607 const char *create_lookup; 608 int error; 609 610 #if NCARP > 0 611 if (rt != NULL && rt->rt_ifp->if_type == IFT_CARP) 612 ifp = rt->rt_ifp; 613 #endif 614 615 KASSERT(m != NULL); 616 617 la = arplookup(ifp, NULL, dst, 0); 618 if (la == NULL) 619 goto notfound; 620 621 if (la->la_flags & LLE_VALID && la->ln_state == ND_LLINFO_REACHABLE) { 622 KASSERT(destlen >= ifp->if_addrlen); 623 memcpy(desten, &la->ll_addr, ifp->if_addrlen); 624 LLE_RUNLOCK(la); 625 return 0; 626 } 627 628 notfound: 629 if (ifp->if_flags & IFF_NOARP) { 630 if (la != NULL) 631 LLE_RUNLOCK(la); 632 error = ENOTSUP; 633 goto bad; 634 } 635 636 if (la == NULL) { 637 struct rtentry *_rt; 638 639 create_lookup = "create"; 640 _rt = rtalloc1(dst, 0); 641 IF_AFDATA_WLOCK(ifp); 642 la = lla_create(LLTABLE(ifp), LLE_EXCLUSIVE, dst, _rt); 643 IF_AFDATA_WUNLOCK(ifp); 644 if (_rt != NULL) 645 rt_unref(_rt); 646 if (la == NULL) 647 ARP_STATINC(ARP_STAT_ALLOCFAIL); 648 else 649 la->ln_state = ND_LLINFO_NOSTATE; 650 } else if (LLE_TRY_UPGRADE(la) == 0) { 651 create_lookup = "lookup"; 652 LLE_RUNLOCK(la); 653 IF_AFDATA_RLOCK(ifp); 654 la = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst); 655 IF_AFDATA_RUNLOCK(ifp); 656 } 657 658 error = EINVAL; 659 if (la == NULL) { 660 log(LOG_DEBUG, 661 "%s: failed to %s llentry for %s on %s\n", 662 __func__, create_lookup, inet_ntoa(satocsin(dst)->sin_addr), 663 ifp->if_xname); 664 goto bad; 665 } 666 667 error = nd_resolve(la, rt, m, desten, destlen); 668 return error; 669 670 bad: 671 m_freem(m); 672 return error; 673 } 674 675 /* 676 * Common length and type checks are done here, 677 * then the protocol-specific routine is called. 678 */ 679 void 680 arpintr(void *arg __unused) 681 { 682 struct mbuf *m; 683 struct arphdr *ar; 684 int s; 685 int arplen; 686 struct ifnet *rcvif; 687 bool badhrd; 688 689 SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE(); 690 while ((m = pktq_dequeue(arp_pktq)) != NULL) { 691 if ((m->m_flags & M_PKTHDR) == 0) 692 panic("arpintr"); 693 694 MCLAIM(m, &arpdomain.dom_mowner); 695 ARP_STATINC(ARP_STAT_RCVTOTAL); 696 697 if (__predict_false(m->m_len < sizeof(*ar))) { 698 if ((m = m_pullup(m, sizeof(*ar))) == NULL) 699 goto badlen; 700 } 701 ar = mtod(m, struct arphdr *); 702 KASSERT(ACCESSIBLE_POINTER(ar, struct arphdr)); 703 704 rcvif = m_get_rcvif(m, &s); 705 if (__predict_false(rcvif == NULL)) { 706 ARP_STATINC(ARP_STAT_RCVNOINT); 707 goto free; 708 } 709 710 /* 711 * We don't want non-IEEE1394 ARP packets on IEEE1394 712 * interfaces, and vice versa. Our life depends on that. 713 */ 714 if (ntohs(ar->ar_hrd) == ARPHRD_IEEE1394) 715 badhrd = rcvif->if_type != IFT_IEEE1394; 716 else 717 badhrd = rcvif->if_type == IFT_IEEE1394; 718 719 m_put_rcvif(rcvif, &s); 720 721 if (badhrd) { 722 ARP_STATINC(ARP_STAT_RCVBADPROTO); 723 goto free; 724 } 725 726 arplen = sizeof(*ar) + 2 * ar->ar_hln + 2 * ar->ar_pln; 727 if (__predict_false(m->m_len < arplen)) { 728 if ((m = m_pullup(m, arplen)) == NULL) 729 goto badlen; 730 ar = mtod(m, struct arphdr *); 731 KASSERT(ACCESSIBLE_POINTER(ar, struct arphdr)); 732 } 733 734 switch (ntohs(ar->ar_pro)) { 735 case ETHERTYPE_IP: 736 case ETHERTYPE_IPTRAILERS: 737 switch (ntohs(ar->ar_op)) { 738 case ARPOP_REQUEST: 739 case ARPOP_REPLY: 740 break; 741 default: 742 ARP_STATINC(ARP_STAT_RCVBADPROTO); 743 goto free; 744 } 745 in_arpinput(m); 746 continue; 747 default: 748 ARP_STATINC(ARP_STAT_RCVBADPROTO); 749 goto free; 750 } 751 752 badlen: 753 ARP_STATINC(ARP_STAT_RCVBADLEN); 754 free: 755 m_freem(m); 756 } 757 SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 758 return; /* XXX gcc */ 759 } 760 761 /* 762 * ARP for Internet protocols on 10 Mb/s Ethernet. Algorithm is that given in 763 * RFC 826. In addition, a sanity check is performed on the sender protocol 764 * address, to catch impersonators. 765 * 766 * We no longer handle negotiations for use of trailer protocol: formerly, ARP 767 * replied for protocol type ETHERTYPE_TRAIL sent along with IP replies if we 768 * wanted trailers sent to us, and also sent them in response to IP replies. 769 * This allowed either end to announce the desire to receive trailer packets. 770 * 771 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, but 772 * formerly didn't normally send requests. 773 */ 774 static void 775 in_arpinput(struct mbuf *m) 776 { 777 struct arphdr *ah; 778 struct ifnet *ifp, *rcvif = NULL; 779 struct llentry *la = NULL; 780 struct in_ifaddr *ia = NULL; 781 #if NBRIDGE > 0 782 struct in_ifaddr *bridge_ia = NULL; 783 #endif 784 #if NCARP > 0 785 uint32_t count = 0, index = 0; 786 #endif 787 struct sockaddr sa; 788 struct in_addr isaddr, itaddr, myaddr; 789 int op, rt_cmd, new_state = 0; 790 void *tha; 791 net_stat_ref_t arps; 792 struct psref psref, psref_ia; 793 int s; 794 char ipbuf[INET_ADDRSTRLEN]; 795 bool find_source, do_dad; 796 797 if (__predict_false(m_makewritable(&m, 0, m->m_pkthdr.len, M_DONTWAIT))) 798 goto out; 799 ah = mtod(m, struct arphdr *); 800 op = ntohs(ah->ar_op); 801 KASSERT(op == ARPOP_REPLY || op == ARPOP_REQUEST); 802 803 if (ah->ar_pln != sizeof(struct in_addr)) 804 goto out; 805 806 /* RFC5227 2.4 says any of the host's own interface addresses 807 * are not conflicting ARP packets. */ 808 ifp = if_get_bylla(ar_sha(ah), ah->ar_hln, &psref); 809 if (ifp) { 810 /* it's from me, ignore it. */ 811 if_put(ifp, &psref); 812 ARP_STATINC(ARP_STAT_RCVLOCALSHA); 813 goto out; 814 } 815 816 rcvif = ifp = m_get_rcvif_psref(m, &psref); 817 if (__predict_false(rcvif == NULL)) 818 goto out; 819 if (rcvif->if_flags & IFF_NOARP) 820 goto out; 821 822 memcpy(&isaddr, ar_spa(ah), sizeof(isaddr)); 823 memcpy(&itaddr, ar_tpa(ah), sizeof(itaddr)); 824 825 if (m->m_flags & (M_BCAST|M_MCAST)) 826 ARP_STATINC(ARP_STAT_RCVMCAST); 827 828 /* 829 * Search for a matching interface address 830 * or any address on the interface to use 831 * as a dummy address in the rest of this function. 832 * 833 * First try and find the source address for early 834 * duplicate address detection. 835 */ 836 if (in_nullhost(isaddr)) { 837 if (in_nullhost(itaddr)) /* very bogus ARP */ 838 goto out; 839 find_source = false; 840 myaddr = itaddr; 841 } else { 842 find_source = true; 843 myaddr = isaddr; 844 } 845 s = pserialize_read_enter(); 846 again: 847 IN_ADDRHASH_READER_FOREACH(ia, myaddr.s_addr) { 848 if (!in_hosteq(ia->ia_addr.sin_addr, myaddr)) 849 continue; 850 #if NCARP > 0 851 if (ia->ia_ifp->if_type == IFT_CARP && 852 ((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) == 853 (IFF_UP|IFF_RUNNING))) { 854 index++; 855 /* XXX: ar_hln? */ 856 if (ia->ia_ifp == rcvif && (ah->ar_hln >= 6) && 857 carp_iamatch(ia, ar_sha(ah), 858 &count, index)) { 859 break; 860 } 861 } else 862 #endif 863 if (ia->ia_ifp == rcvif) 864 break; 865 #if NBRIDGE > 0 866 /* 867 * If the interface we received the packet on 868 * is part of a bridge, check to see if we need 869 * to "bridge" the packet to ourselves at this 870 * layer. Note we still prefer a perfect match, 871 * but allow this weaker match if necessary. 872 */ 873 if (rcvif->if_bridge != NULL && 874 rcvif->if_bridge == ia->ia_ifp->if_bridge) 875 bridge_ia = ia; 876 #endif 877 } 878 879 #if NBRIDGE > 0 880 if (ia == NULL && bridge_ia != NULL) { 881 ia = bridge_ia; 882 m_put_rcvif_psref(rcvif, &psref); 883 rcvif = NULL; 884 /* FIXME */ 885 ifp = bridge_ia->ia_ifp; 886 } 887 #endif 888 889 /* If we failed to find the source address then find 890 * the target address. */ 891 if (ia == NULL && find_source && !in_nullhost(itaddr)) { 892 find_source = false; 893 myaddr = itaddr; 894 goto again; 895 } 896 897 if (ia != NULL) 898 ia4_acquire(ia, &psref_ia); 899 pserialize_read_exit(s); 900 901 if (ah->ar_hln != ifp->if_addrlen) { 902 ARP_STATINC(ARP_STAT_RCVBADLEN); 903 log(LOG_WARNING, 904 "arp from %s: addr len: new %d, i/f %d (ignored)\n", 905 IN_PRINT(ipbuf, &isaddr), ah->ar_hln, ifp->if_addrlen); 906 goto out; 907 } 908 909 /* Only do DaD if we have a matching address. */ 910 do_dad = (ia != NULL); 911 912 if (ia == NULL) { 913 ia = in_get_ia_on_iface_psref(isaddr, rcvif, &psref_ia); 914 if (ia == NULL) { 915 ia = in_get_ia_from_ifp_psref(ifp, &psref_ia); 916 if (ia == NULL) { 917 ARP_STATINC(ARP_STAT_RCVNOINT); 918 goto out; 919 } 920 } 921 } 922 923 myaddr = ia->ia_addr.sin_addr; 924 925 /* XXX checks for bridge case? */ 926 if (!memcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 927 ARP_STATINC(ARP_STAT_RCVBCASTSHA); 928 log(LOG_ERR, 929 "%s: arp: link address is broadcast for IP address %s!\n", 930 ifp->if_xname, IN_PRINT(ipbuf, &isaddr)); 931 goto out; 932 } 933 934 /* 935 * If the source IP address is zero, this is an RFC 5227 ARP probe 936 */ 937 if (in_nullhost(isaddr)) 938 ARP_STATINC(ARP_STAT_RCVZEROSPA); 939 else if (in_hosteq(isaddr, myaddr)) { 940 ARP_STATINC(ARP_STAT_RCVLOCALSPA); 941 /* This is the original behavior prior to supporting IPv4 DAD */ 942 if (!ip_dad_enabled()) { 943 char llabuf[LLA_ADDRSTRLEN]; 944 log(LOG_ERR, 945 "duplicate IP address %s sent from link address %s\n", 946 IN_PRINT(ipbuf, &isaddr), 947 lla_snprintf(llabuf, sizeof(llabuf), ar_sha(ah), 948 ah->ar_hln)); 949 itaddr = myaddr; 950 goto reply; 951 } 952 } 953 954 if (in_nullhost(itaddr)) 955 ARP_STATINC(ARP_STAT_RCVZEROTPA); 956 957 /* 958 * DAD check, RFC 5227. 959 * ARP sender hardware address must match the interface 960 * address of the interface sending the packet. 961 * Collision on sender address is always a duplicate. 962 * Collision on target address is only a duplicate 963 * IF the sender address is the null host (ie a DAD probe) 964 * AND the message was broadcast 965 * AND our address is either tentative or duplicated 966 * If it was unicast then it's a valid Unicast Poll from RFC 1122. 967 */ 968 if (ip_dad_enabled() && do_dad && 969 (in_hosteq(isaddr, myaddr) || 970 (in_nullhost(isaddr) && in_hosteq(itaddr, myaddr) && 971 m->m_flags & M_BCAST && 972 ia->ia4_flags & (IN_IFF_TENTATIVE | IN_IFF_DUPLICATED)))) 973 { 974 struct m_tag *mtag; 975 976 mtag = m_tag_find(m, PACKET_TAG_ETHERNET_SRC); 977 if (mtag == NULL || (ah->ar_hln == ETHER_ADDR_LEN && 978 memcmp(mtag + 1, ar_sha(ah), ah->ar_hln) == 0)) { 979 struct sockaddr_dl sdl, *sdlp; 980 981 sdlp = sockaddr_dl_init(&sdl, sizeof(sdl), 982 ifp->if_index, ifp->if_type, 983 NULL, 0, ar_sha(ah), ah->ar_hln); 984 arp_dad_duplicated((struct ifaddr *)ia, sdlp); 985 goto out; 986 } 987 } 988 989 /* 990 * If the target IP address is zero, ignore the packet. 991 * This prevents the code below from trying to answer 992 * when we are using IP address zero (booting). 993 */ 994 if (in_nullhost(itaddr)) 995 goto out; 996 997 if (in_nullhost(isaddr)) 998 goto reply; 999 1000 if (in_hosteq(itaddr, myaddr)) 1001 la = arpcreate(ifp, &isaddr, NULL, 1); 1002 else 1003 la = arplookup(ifp, &isaddr, NULL, 1); 1004 if (la == NULL) 1005 goto reply; 1006 1007 if ((la->la_flags & LLE_VALID) && 1008 memcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) 1009 { 1010 char llabuf[LLA_ADDRSTRLEN], *llastr; 1011 1012 llastr = lla_snprintf(llabuf, sizeof(llabuf), 1013 ar_sha(ah), ah->ar_hln); 1014 1015 if (la->la_flags & LLE_STATIC) { 1016 ARP_STATINC(ARP_STAT_RCVOVERPERM); 1017 if (!log_permanent_modify) 1018 goto out; 1019 log(LOG_INFO, 1020 "%s tried to overwrite permanent arp info" 1021 " for %s\n", llastr, IN_PRINT(ipbuf, &isaddr)); 1022 goto out; 1023 } else if (la->lle_tbl->llt_ifp != ifp) { 1024 /* XXX should not happen? */ 1025 ARP_STATINC(ARP_STAT_RCVOVERINT); 1026 if (!log_wrong_iface) 1027 goto out; 1028 log(LOG_INFO, 1029 "%s on %s tried to overwrite " 1030 "arp info for %s on %s\n", 1031 llastr, 1032 ifp->if_xname, IN_PRINT(ipbuf, &isaddr), 1033 la->lle_tbl->llt_ifp->if_xname); 1034 goto out; 1035 } else { 1036 ARP_STATINC(ARP_STAT_RCVOVER); 1037 if (log_movements) 1038 log(LOG_INFO, "arp info overwritten " 1039 "for %s by %s\n", 1040 IN_PRINT(ipbuf, &isaddr), llastr); 1041 } 1042 rt_cmd = RTM_CHANGE; 1043 new_state = ND_LLINFO_STALE; 1044 } else { 1045 if (op == ARPOP_REPLY && in_hosteq(itaddr, myaddr)) { 1046 /* This was a solicited ARP reply. */ 1047 la->ln_byhint = 0; 1048 new_state = ND_LLINFO_REACHABLE; 1049 } else if (op == ARPOP_REQUEST && 1050 (la->ln_state == ND_LLINFO_NOSTATE || 1051 la->ln_state == ND_LLINFO_INCOMPLETE)) { 1052 /* 1053 * If an ARP request comes but there is no entry 1054 * and a new one has been created or an entry exists 1055 * but incomplete, make it stale to allow to send 1056 * packets to the requester without an ARP resolution. 1057 */ 1058 la->ln_byhint = 0; 1059 new_state = ND_LLINFO_STALE; 1060 } 1061 rt_cmd = la->la_flags & LLE_VALID ? 0 : RTM_ADD; 1062 } 1063 1064 KASSERT(ifp->if_sadl->sdl_alen == ifp->if_addrlen); 1065 1066 KASSERT(sizeof(la->ll_addr) >= ifp->if_addrlen); 1067 memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen); 1068 la->la_flags |= LLE_VALID; 1069 la->la_flags &= ~LLE_UNRESOLVED; 1070 la->ln_asked = 0; 1071 if (new_state != 0) { 1072 la->ln_state = new_state; 1073 1074 if (new_state != ND_LLINFO_REACHABLE || 1075 !(la->la_flags & LLE_STATIC)) 1076 { 1077 int timer = ND_TIMER_GC; 1078 1079 if (new_state == ND_LLINFO_REACHABLE) 1080 timer = ND_TIMER_REACHABLE; 1081 nd_set_timer(la, timer); 1082 } 1083 } 1084 1085 if (rt_cmd != 0) { 1086 struct sockaddr_in sin; 1087 1088 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 1089 rt_clonedmsg(rt_cmd, NULL, sintosa(&sin), ar_sha(ah), ifp); 1090 } 1091 1092 if (la->la_hold != NULL) { 1093 int n = la->la_numheld; 1094 struct mbuf *m_hold, *m_hold_next; 1095 struct sockaddr_in sin; 1096 1097 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 1098 1099 m_hold = la->la_hold; 1100 la->la_hold = NULL; 1101 la->la_numheld = 0; 1102 /* 1103 * We have to unlock here because if_output would call 1104 * arpresolve 1105 */ 1106 LLE_WUNLOCK(la); 1107 ARP_STATADD(ARP_STAT_DFRSENT, n); 1108 ARP_STATADD(ARP_STAT_DFRTOTAL, n); 1109 for (; m_hold != NULL; m_hold = m_hold_next) { 1110 m_hold_next = m_hold->m_nextpkt; 1111 m_hold->m_nextpkt = NULL; 1112 if_output_lock(ifp, ifp, m_hold, sintosa(&sin), NULL); 1113 } 1114 } else 1115 LLE_WUNLOCK(la); 1116 la = NULL; 1117 1118 reply: 1119 if (la != NULL) { 1120 LLE_WUNLOCK(la); 1121 la = NULL; 1122 } 1123 if (op != ARPOP_REQUEST) { 1124 KASSERT(op == ARPOP_REPLY); 1125 ARP_STATINC(ARP_STAT_RCVREPLY); 1126 goto out; 1127 } 1128 ARP_STATINC(ARP_STAT_RCVREQUEST); 1129 if (in_hosteq(itaddr, myaddr)) { 1130 /* If our address is unusable, don't reply */ 1131 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) 1132 goto out; 1133 /* I am the target */ 1134 tha = ar_tha(ah); 1135 if (tha) 1136 memcpy(tha, ar_sha(ah), ah->ar_hln); 1137 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1138 } else { 1139 /* Proxy ARP */ 1140 struct llentry *lle = NULL; 1141 struct sockaddr_in sin; 1142 1143 #if NCARP > 0 1144 if (ifp->if_type == IFT_CARP) { 1145 struct ifnet *_rcvif = m_get_rcvif(m, &s); 1146 int iftype = 0; 1147 if (__predict_true(_rcvif != NULL)) 1148 iftype = _rcvif->if_type; 1149 m_put_rcvif(_rcvif, &s); 1150 if (iftype != IFT_CARP) 1151 goto out; 1152 } 1153 #endif 1154 1155 tha = ar_tha(ah); 1156 1157 sockaddr_in_init(&sin, &itaddr, 0); 1158 1159 IF_AFDATA_RLOCK(ifp); 1160 lle = lla_lookup(LLTABLE(ifp), 0, (struct sockaddr *)&sin); 1161 IF_AFDATA_RUNLOCK(ifp); 1162 1163 if ((lle != NULL) && (lle->la_flags & LLE_PUB)) { 1164 if (tha) 1165 memcpy(tha, ar_sha(ah), ah->ar_hln); 1166 memcpy(ar_sha(ah), &lle->ll_addr, ah->ar_hln); 1167 LLE_RUNLOCK(lle); 1168 } else { 1169 if (lle != NULL) 1170 LLE_RUNLOCK(lle); 1171 goto out; 1172 } 1173 } 1174 ia4_release(ia, &psref_ia); 1175 1176 /* 1177 * XXX XXX: Here we're recycling the mbuf. But the mbuf could have 1178 * other mbufs in its chain, and just overwriting m->m_pkthdr.len 1179 * would be wrong in this case (the length becomes smaller than the 1180 * real chain size). 1181 * 1182 * This can theoretically cause bugs in the lower layers (drivers, 1183 * and L2encap), in some corner cases. 1184 */ 1185 memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); 1186 memcpy(ar_spa(ah), &itaddr, ah->ar_pln); 1187 ah->ar_op = htons(ARPOP_REPLY); 1188 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 1189 switch (ifp->if_type) { 1190 case IFT_IEEE1394: 1191 /* ieee1394 arp reply is broadcast */ 1192 m->m_flags &= ~M_MCAST; 1193 m->m_flags |= M_BCAST; 1194 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + ah->ar_hln; 1195 break; 1196 default: 1197 m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */ 1198 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); 1199 break; 1200 } 1201 m->m_pkthdr.len = m->m_len; 1202 m->m_pkthdr.csum_flags = 0; /* Clear any in-bound checksum flags. */ 1203 sa.sa_family = AF_ARP; 1204 sa.sa_len = 2; 1205 arps = ARP_STAT_GETREF(); 1206 _NET_STATINC_REF(arps, ARP_STAT_SNDTOTAL); 1207 _NET_STATINC_REF(arps, ARP_STAT_SNDREPLY); 1208 ARP_STAT_PUTREF(); 1209 if_output_lock(ifp, ifp, m, &sa, NULL); 1210 if (rcvif != NULL) 1211 m_put_rcvif_psref(rcvif, &psref); 1212 return; 1213 1214 out: 1215 if (la != NULL) 1216 LLE_WUNLOCK(la); 1217 if (ia != NULL) 1218 ia4_release(ia, &psref_ia); 1219 if (rcvif != NULL) 1220 m_put_rcvif_psref(rcvif, &psref); 1221 m_freem(m); 1222 } 1223 1224 /* 1225 * Lookup or a new address in arptab. 1226 */ 1227 struct llentry * 1228 arplookup(struct ifnet *ifp, const struct in_addr *addr, 1229 const struct sockaddr *sa, int wlock) 1230 { 1231 struct sockaddr_in sin; 1232 struct llentry *la; 1233 int flags = wlock ? LLE_EXCLUSIVE : 0; 1234 1235 if (sa == NULL) { 1236 KASSERT(addr != NULL); 1237 sockaddr_in_init(&sin, addr, 0); 1238 sa = sintocsa(&sin); 1239 } 1240 1241 IF_AFDATA_RLOCK(ifp); 1242 la = lla_lookup(LLTABLE(ifp), flags, sa); 1243 IF_AFDATA_RUNLOCK(ifp); 1244 1245 return la; 1246 } 1247 1248 static struct llentry * 1249 arpcreate(struct ifnet *ifp, const struct in_addr *addr, 1250 const struct sockaddr *sa, int wlock) 1251 { 1252 struct sockaddr_in sin; 1253 struct llentry *la; 1254 int flags = wlock ? LLE_EXCLUSIVE : 0; 1255 1256 if (sa == NULL) { 1257 KASSERT(addr != NULL); 1258 sockaddr_in_init(&sin, addr, 0); 1259 sa = sintocsa(&sin); 1260 } 1261 1262 la = arplookup(ifp, addr, sa, wlock); 1263 1264 if (la == NULL) { 1265 struct rtentry *rt; 1266 1267 rt = rtalloc1(sa, 0); 1268 IF_AFDATA_WLOCK(ifp); 1269 la = lla_create(LLTABLE(ifp), flags, sa, rt); 1270 IF_AFDATA_WUNLOCK(ifp); 1271 if (rt != NULL) 1272 rt_unref(rt); 1273 1274 if (la != NULL) 1275 la->ln_state = ND_LLINFO_NOSTATE; 1276 } 1277 1278 return la; 1279 } 1280 1281 int 1282 arpioctl(u_long cmd, void *data) 1283 { 1284 1285 return EOPNOTSUPP; 1286 } 1287 1288 void 1289 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1290 { 1291 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1292 1293 ifa->ifa_rtrequest = arp_rtrequest; 1294 ifa->ifa_flags |= RTF_CONNECTED; 1295 1296 /* ARP will handle DAD for this address. */ 1297 if (in_nullhost(IA_SIN(ifa)->sin_addr)) { 1298 if (ia->ia_dad_stop != NULL) /* safety */ 1299 ia->ia_dad_stop(ifa); 1300 ia->ia_dad_start = NULL; 1301 ia->ia_dad_stop = NULL; 1302 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1303 } else { 1304 ia->ia_dad_start = arp_dad_start; 1305 ia->ia_dad_stop = arp_dad_stop; 1306 if (ia->ia4_flags & IN_IFF_TRYTENTATIVE && ip_dad_enabled()) 1307 ia->ia4_flags |= IN_IFF_TENTATIVE; 1308 else 1309 arpannounce1(ifa); 1310 } 1311 } 1312 1313 static bool 1314 arp_nud_enabled(__unused struct ifnet *ifp) 1315 { 1316 1317 return arp_perform_nud != 0; 1318 } 1319 1320 static unsigned int 1321 arp_llinfo_reachable(__unused struct ifnet *ifp) 1322 { 1323 1324 return arp_reachable; 1325 } 1326 1327 static unsigned int 1328 arp_llinfo_retrans(__unused struct ifnet *ifp) 1329 { 1330 1331 return arp_retrans; 1332 } 1333 1334 /* 1335 * Gets source address of the first packet in hold queue 1336 * and stores it in @src. 1337 * Returns pointer to @src (if hold queue is not empty) or NULL. 1338 */ 1339 static union l3addr * 1340 arp_llinfo_holdsrc(struct llentry *ln, union l3addr *src) 1341 { 1342 struct ip *ip; 1343 1344 if (ln == NULL || ln->ln_hold == NULL) 1345 return NULL; 1346 1347 /* 1348 * assuming every packet in ln_hold has the same IP header 1349 */ 1350 ip = mtod(ln->ln_hold, struct ip *); 1351 /* XXX pullup? */ 1352 if (sizeof(*ip) < ln->ln_hold->m_len) 1353 src->addr4 = ip->ip_src; 1354 else 1355 src = NULL; 1356 1357 return src; 1358 } 1359 1360 static void 1361 arp_llinfo_output(struct ifnet *ifp, __unused const union l3addr *daddr, 1362 const union l3addr *taddr, const uint8_t *tlladdr, 1363 const union l3addr *hsrc) 1364 { 1365 struct in_addr tip = taddr->addr4, sip = zeroin_addr; 1366 const uint8_t *slladdr = CLLADDR(ifp->if_sadl); 1367 1368 if (hsrc != NULL) { 1369 struct in_ifaddr *ia; 1370 struct psref psref; 1371 1372 ia = in_get_ia_on_iface_psref(hsrc->addr4, ifp, &psref); 1373 if (ia != NULL) { 1374 sip = hsrc->addr4; 1375 ia4_release(ia, &psref); 1376 } 1377 } 1378 1379 if (sip.s_addr == INADDR_ANY) { 1380 struct sockaddr_in dst; 1381 struct rtentry *rt; 1382 1383 sockaddr_in_init(&dst, &tip, 0); 1384 rt = rtalloc1(sintosa(&dst), 0); 1385 if (rt != NULL) { 1386 if (rt->rt_ifp == ifp && 1387 rt->rt_ifa != NULL && 1388 rt->rt_ifa->ifa_addr->sa_family == AF_INET) 1389 sip = satosin(rt->rt_ifa->ifa_addr)->sin_addr; 1390 rt_unref(rt); 1391 } 1392 if (sip.s_addr == INADDR_ANY) { 1393 char ipbuf[INET_ADDRSTRLEN]; 1394 1395 log(LOG_DEBUG, "%s: source can't be " 1396 "determined: dst=%s\n", __func__, 1397 IN_PRINT(ipbuf, &tip)); 1398 return; 1399 } 1400 } 1401 1402 arprequest(ifp, &sip, &tip, slladdr, tlladdr); 1403 } 1404 1405 1406 static void 1407 arp_llinfo_missed(struct ifnet *ifp, const union l3addr *taddr, 1408 __unused int16_t type, struct mbuf *m) 1409 { 1410 struct in_addr mdaddr = zeroin_addr; 1411 struct sockaddr_in dsin, tsin; 1412 struct sockaddr *sa; 1413 1414 if (m != NULL) { 1415 struct ip *ip = mtod(m, struct ip *); 1416 1417 if (sizeof(*ip) < m->m_len) 1418 mdaddr = ip->ip_src; 1419 1420 /* ip_input() will send ICMP_UNREACH_HOST, not us. */ 1421 m_freem(m); 1422 } 1423 1424 if (mdaddr.s_addr != INADDR_ANY) { 1425 sockaddr_in_init(&dsin, &mdaddr, 0); 1426 sa = sintosa(&dsin); 1427 } else 1428 sa = NULL; 1429 1430 sockaddr_in_init(&tsin, &taddr->addr4, 0); 1431 rt_clonedmsg(RTM_MISS, sa, sintosa(&tsin), NULL, ifp); 1432 } 1433 1434 static void 1435 arp_free(struct llentry *ln, int gc) 1436 { 1437 struct ifnet *ifp; 1438 1439 KASSERT(ln != NULL); 1440 LLE_WLOCK_ASSERT(ln); 1441 1442 ifp = ln->lle_tbl->llt_ifp; 1443 1444 if (ln->la_flags & LLE_VALID || gc) { 1445 struct sockaddr_in sin; 1446 const char *lladdr; 1447 1448 sockaddr_in_init(&sin, &ln->r_l3addr.addr4, 0); 1449 lladdr = ln->la_flags & LLE_VALID ? 1450 (const char *)&ln->ll_addr : NULL; 1451 rt_clonedmsg(RTM_DELETE, NULL, sintosa(&sin), lladdr, ifp); 1452 } 1453 1454 /* 1455 * Save to unlock. We still hold an extra reference and will not 1456 * free(9) in llentry_free() if someone else holds one as well. 1457 */ 1458 LLE_WUNLOCK(ln); 1459 IF_AFDATA_LOCK(ifp); 1460 LLE_WLOCK(ln); 1461 1462 lltable_free_entry(LLTABLE(ifp), ln); 1463 1464 IF_AFDATA_UNLOCK(ifp); 1465 } 1466 1467 /* 1468 * Upper-layer reachability hint for Neighbor Unreachability Detection. 1469 * 1470 * XXX cost-effective methods? 1471 */ 1472 void 1473 arp_nud_hint(struct rtentry *rt) 1474 { 1475 struct llentry *ln; 1476 struct ifnet *ifp; 1477 1478 if (rt == NULL) 1479 return; 1480 1481 ifp = rt->rt_ifp; 1482 ln = arplookup(ifp, NULL, rt_getkey(rt), 1); 1483 nd_nud_hint(ln); 1484 } 1485 1486 TAILQ_HEAD(dadq_head, dadq); 1487 struct dadq { 1488 TAILQ_ENTRY(dadq) dad_list; 1489 struct ifaddr *dad_ifa; 1490 int dad_count; /* max ARP to send */ 1491 int dad_arp_tcount; /* # of trials to send ARP */ 1492 int dad_arp_ocount; /* ARP sent so far */ 1493 int dad_arp_announce; /* max ARP announcements */ 1494 int dad_arp_acount; /* # of announcements */ 1495 struct callout dad_timer_ch; 1496 }; 1497 1498 static struct dadq_head dadq; 1499 static int dad_maxtry = 15; /* max # of *tries* to transmit DAD packet */ 1500 static kmutex_t arp_dad_lock; 1501 1502 static void 1503 arp_dad_init(void) 1504 { 1505 1506 TAILQ_INIT(&dadq); 1507 mutex_init(&arp_dad_lock, MUTEX_DEFAULT, IPL_NONE); 1508 } 1509 1510 static struct dadq * 1511 arp_dad_find(struct ifaddr *ifa) 1512 { 1513 struct dadq *dp; 1514 1515 KASSERT(mutex_owned(&arp_dad_lock)); 1516 1517 TAILQ_FOREACH(dp, &dadq, dad_list) { 1518 if (dp->dad_ifa == ifa) 1519 return dp; 1520 } 1521 return NULL; 1522 } 1523 1524 static void 1525 arp_dad_starttimer(struct dadq *dp, int ticks) 1526 { 1527 1528 callout_reset(&dp->dad_timer_ch, ticks, 1529 (void (*)(void *))arp_dad_timer, dp); 1530 } 1531 1532 static void 1533 arp_dad_stoptimer(struct dadq *dp) 1534 { 1535 1536 KASSERT(mutex_owned(&arp_dad_lock)); 1537 1538 TAILQ_REMOVE(&dadq, dp, dad_list); 1539 /* Tell the timer that dp is being destroyed. */ 1540 dp->dad_ifa = NULL; 1541 callout_halt(&dp->dad_timer_ch, &arp_dad_lock); 1542 } 1543 1544 static void 1545 arp_dad_destroytimer(struct dadq *dp) 1546 { 1547 1548 callout_destroy(&dp->dad_timer_ch); 1549 KASSERT(dp->dad_ifa == NULL); 1550 kmem_intr_free(dp, sizeof(*dp)); 1551 } 1552 1553 static void 1554 arp_dad_output(struct dadq *dp, struct ifaddr *ifa) 1555 { 1556 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1557 struct ifnet *ifp = ifa->ifa_ifp; 1558 struct in_addr sip; 1559 1560 dp->dad_arp_tcount++; 1561 if ((ifp->if_flags & IFF_UP) == 0) 1562 return; 1563 if ((ifp->if_flags & IFF_RUNNING) == 0) 1564 return; 1565 1566 dp->dad_arp_tcount = 0; 1567 dp->dad_arp_ocount++; 1568 1569 memset(&sip, 0, sizeof(sip)); 1570 arprequest(ifa->ifa_ifp, &sip, &ia->ia_addr.sin_addr, 1571 CLLADDR(ifa->ifa_ifp->if_sadl), NULL); 1572 } 1573 1574 /* 1575 * Start Duplicate Address Detection (DAD) for specified interface address. 1576 */ 1577 static void 1578 arp_dad_start(struct ifaddr *ifa) 1579 { 1580 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1581 struct dadq *dp; 1582 char ipbuf[INET_ADDRSTRLEN]; 1583 1584 /* 1585 * If we don't need DAD, don't do it. 1586 * - DAD is disabled 1587 */ 1588 if (!(ia->ia4_flags & IN_IFF_TENTATIVE)) { 1589 log(LOG_DEBUG, 1590 "%s: called with non-tentative address %s(%s)\n", __func__, 1591 IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1592 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1593 return; 1594 } 1595 if (!ip_dad_enabled()) { 1596 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1597 rt_addrmsg(RTM_NEWADDR, ifa); 1598 arpannounce1(ifa); 1599 return; 1600 } 1601 KASSERT(ifa->ifa_ifp != NULL); 1602 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) 1603 return; 1604 1605 dp = kmem_intr_alloc(sizeof(*dp), KM_NOSLEEP); 1606 1607 mutex_enter(&arp_dad_lock); 1608 if (arp_dad_find(ifa) != NULL) { 1609 mutex_exit(&arp_dad_lock); 1610 /* DAD already in progress */ 1611 if (dp != NULL) 1612 kmem_intr_free(dp, sizeof(*dp)); 1613 return; 1614 } 1615 1616 if (dp == NULL) { 1617 mutex_exit(&arp_dad_lock); 1618 log(LOG_ERR, "%s: memory allocation failed for %s(%s)\n", 1619 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1620 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1621 return; 1622 } 1623 1624 /* 1625 * Send ARP packet for DAD, ip_dad_count times. 1626 * Note that we must delay the first transmission. 1627 */ 1628 callout_init(&dp->dad_timer_ch, CALLOUT_MPSAFE); 1629 dp->dad_ifa = ifa; 1630 ifaref(ifa); /* just for safety */ 1631 dp->dad_count = ip_dad_count; 1632 dp->dad_arp_announce = 0; /* Will be set when starting to announce */ 1633 dp->dad_arp_acount = dp->dad_arp_ocount = dp->dad_arp_tcount = 0; 1634 TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list); 1635 1636 ARPLOG(LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1637 ARPLOGADDR(&ia->ia_addr.sin_addr)); 1638 1639 arp_dad_starttimer(dp, cprng_fast32() % (PROBE_WAIT * hz)); 1640 1641 mutex_exit(&arp_dad_lock); 1642 } 1643 1644 /* 1645 * terminate DAD unconditionally. used for address removals. 1646 */ 1647 static void 1648 arp_dad_stop(struct ifaddr *ifa) 1649 { 1650 struct dadq *dp; 1651 1652 mutex_enter(&arp_dad_lock); 1653 dp = arp_dad_find(ifa); 1654 if (dp == NULL) { 1655 mutex_exit(&arp_dad_lock); 1656 /* DAD wasn't started yet */ 1657 return; 1658 } 1659 1660 arp_dad_stoptimer(dp); 1661 1662 mutex_exit(&arp_dad_lock); 1663 1664 arp_dad_destroytimer(dp); 1665 ifafree(ifa); 1666 } 1667 1668 static void 1669 arp_dad_timer(struct dadq *dp) 1670 { 1671 struct ifaddr *ifa; 1672 struct in_ifaddr *ia; 1673 char ipbuf[INET_ADDRSTRLEN]; 1674 bool need_free = false; 1675 1676 KERNEL_LOCK_UNLESS_NET_MPSAFE(); 1677 mutex_enter(&arp_dad_lock); 1678 1679 ifa = dp->dad_ifa; 1680 if (ifa == NULL) { 1681 /* dp is being destroyed by someone. Do nothing. */ 1682 goto done; 1683 } 1684 1685 ia = (struct in_ifaddr *)ifa; 1686 if (ia->ia4_flags & IN_IFF_DUPLICATED) { 1687 log(LOG_ERR, "%s: called with duplicate address %s(%s)\n", 1688 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1689 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1690 goto done; 1691 } 1692 if ((ia->ia4_flags & IN_IFF_TENTATIVE) == 0 && dp->dad_arp_acount == 0) 1693 { 1694 log(LOG_ERR, "%s: called with non-tentative address %s(%s)\n", 1695 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1696 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1697 goto done; 1698 } 1699 1700 /* timeouted with IFF_{RUNNING,UP} check */ 1701 if (dp->dad_arp_tcount > dad_maxtry) { 1702 ARPLOG(LOG_INFO, "%s: could not run DAD, driver problem?\n", 1703 if_name(ifa->ifa_ifp)); 1704 1705 arp_dad_stoptimer(dp); 1706 need_free = true; 1707 goto done; 1708 } 1709 1710 /* Need more checks? */ 1711 if (dp->dad_arp_ocount < dp->dad_count) { 1712 int adelay; 1713 1714 /* 1715 * We have more ARP to go. Send ARP packet for DAD. 1716 */ 1717 arp_dad_output(dp, ifa); 1718 if (dp->dad_arp_ocount < dp->dad_count) 1719 adelay = (PROBE_MIN * hz) + 1720 (cprng_fast32() % 1721 ((PROBE_MAX * hz) - (PROBE_MIN * hz))); 1722 else 1723 adelay = ANNOUNCE_WAIT * hz; 1724 arp_dad_starttimer(dp, adelay); 1725 goto done; 1726 } else if (dp->dad_arp_acount == 0) { 1727 /* 1728 * We are done with DAD. 1729 * No duplicate address found. 1730 */ 1731 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1732 rt_addrmsg(RTM_NEWADDR, ifa); 1733 ARPLOG(LOG_DEBUG, 1734 "%s: DAD complete for %s - no duplicates found\n", 1735 if_name(ifa->ifa_ifp), ARPLOGADDR(&ia->ia_addr.sin_addr)); 1736 dp->dad_arp_announce = ANNOUNCE_NUM; 1737 goto announce; 1738 } else if (dp->dad_arp_acount < dp->dad_arp_announce) { 1739 announce: 1740 /* 1741 * Announce the address. 1742 */ 1743 arpannounce1(ifa); 1744 dp->dad_arp_acount++; 1745 if (dp->dad_arp_acount < dp->dad_arp_announce) { 1746 arp_dad_starttimer(dp, ANNOUNCE_INTERVAL * hz); 1747 goto done; 1748 } 1749 ARPLOG(LOG_DEBUG, 1750 "%s: ARP announcement complete for %s\n", 1751 if_name(ifa->ifa_ifp), ARPLOGADDR(&ia->ia_addr.sin_addr)); 1752 } 1753 1754 arp_dad_stoptimer(dp); 1755 need_free = true; 1756 done: 1757 mutex_exit(&arp_dad_lock); 1758 1759 if (need_free) { 1760 arp_dad_destroytimer(dp); 1761 KASSERT(ifa != NULL); 1762 ifafree(ifa); 1763 } 1764 1765 KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 1766 } 1767 1768 static void 1769 arp_dad_duplicated(struct ifaddr *ifa, const struct sockaddr_dl *from) 1770 { 1771 struct in_ifaddr *ia = ifatoia(ifa); 1772 struct ifnet *ifp = ifa->ifa_ifp; 1773 char ipbuf[INET_ADDRSTRLEN], llabuf[LLA_ADDRSTRLEN]; 1774 const char *iastr, *llastr; 1775 1776 iastr = IN_PRINT(ipbuf, &ia->ia_addr.sin_addr); 1777 if (__predict_false(from == NULL)) 1778 llastr = NULL; 1779 else 1780 llastr = lla_snprintf(llabuf, sizeof(llabuf), 1781 CLLADDR(from), from->sdl_alen); 1782 1783 if (ia->ia4_flags & (IN_IFF_TENTATIVE|IN_IFF_DUPLICATED)) { 1784 log(LOG_ERR, 1785 "%s: DAD duplicate address %s from %s\n", 1786 if_name(ifp), iastr, llastr); 1787 } else if (ia->ia_dad_defended == 0 || 1788 ia->ia_dad_defended < time_uptime - DEFEND_INTERVAL) { 1789 ia->ia_dad_defended = time_uptime; 1790 arpannounce1(ifa); 1791 log(LOG_ERR, 1792 "%s: DAD defended address %s from %s\n", 1793 if_name(ifp), iastr, llastr); 1794 return; 1795 } else { 1796 /* If DAD is disabled, just report the duplicate. */ 1797 if (!ip_dad_enabled()) { 1798 log(LOG_ERR, 1799 "%s: DAD ignoring duplicate address %s from %s\n", 1800 if_name(ifp), iastr, llastr); 1801 return; 1802 } 1803 log(LOG_ERR, 1804 "%s: DAD defence failed for %s from %s\n", 1805 if_name(ifp), iastr, llastr); 1806 } 1807 1808 arp_dad_stop(ifa); 1809 1810 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1811 if ((ia->ia4_flags & IN_IFF_DUPLICATED) == 0) { 1812 ia->ia4_flags |= IN_IFF_DUPLICATED; 1813 /* Inform the routing socket of the duplicate address */ 1814 rt_addrmsg_src(RTM_NEWADDR, ifa, (const struct sockaddr *)from); 1815 } 1816 } 1817 1818 /* 1819 * Called from 10 Mb/s Ethernet interrupt handlers 1820 * when ether packet type ETHERTYPE_REVARP 1821 * is received. Common length and type checks are done here, 1822 * then the protocol-specific routine is called. 1823 */ 1824 void 1825 revarpinput(struct mbuf *m) 1826 { 1827 struct arphdr *ar; 1828 int arplen; 1829 1830 arplen = sizeof(struct arphdr); 1831 if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL) 1832 return; 1833 ar = mtod(m, struct arphdr *); 1834 1835 if (ntohs(ar->ar_hrd) == ARPHRD_IEEE1394) { 1836 goto out; 1837 } 1838 1839 arplen = sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln); 1840 if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL) 1841 return; 1842 ar = mtod(m, struct arphdr *); 1843 1844 switch (ntohs(ar->ar_pro)) { 1845 case ETHERTYPE_IP: 1846 case ETHERTYPE_IPTRAILERS: 1847 in_revarpinput(m); 1848 return; 1849 1850 default: 1851 break; 1852 } 1853 1854 out: 1855 m_freem(m); 1856 } 1857 1858 /* 1859 * RARP for Internet protocols on 10 Mb/s Ethernet. 1860 * Algorithm is that given in RFC 903. 1861 * We are only using for bootstrap purposes to get an ip address for one of 1862 * our interfaces. Thus we support no user-interface. 1863 * 1864 * Since the contents of the RARP reply are specific to the interface that 1865 * sent the request, this code must ensure that they are properly associated. 1866 * 1867 * Note: also supports ARP via RARP packets, per the RFC. 1868 */ 1869 void 1870 in_revarpinput(struct mbuf *m) 1871 { 1872 struct arphdr *ah; 1873 void *tha; 1874 int op; 1875 struct ifnet *rcvif; 1876 int s; 1877 1878 ah = mtod(m, struct arphdr *); 1879 op = ntohs(ah->ar_op); 1880 1881 rcvif = m_get_rcvif(m, &s); 1882 if (__predict_false(rcvif == NULL)) 1883 goto out; 1884 if (rcvif->if_flags & IFF_NOARP) 1885 goto out; 1886 1887 switch (rcvif->if_type) { 1888 case IFT_IEEE1394: 1889 /* ARP without target hardware address is not supported */ 1890 goto out; 1891 default: 1892 break; 1893 } 1894 1895 switch (op) { 1896 case ARPOP_REQUEST: 1897 case ARPOP_REPLY: /* per RFC */ 1898 m_put_rcvif(rcvif, &s); 1899 in_arpinput(m); 1900 return; 1901 case ARPOP_REVREPLY: 1902 break; 1903 case ARPOP_REVREQUEST: /* handled by rarpd(8) */ 1904 default: 1905 goto out; 1906 } 1907 if (!revarp_in_progress) 1908 goto out; 1909 if (rcvif != myip_ifp) /* !same interface */ 1910 goto out; 1911 if (myip_initialized) 1912 goto wake; 1913 tha = ar_tha(ah); 1914 if (tha == NULL) 1915 goto out; 1916 if (ah->ar_pln != sizeof(struct in_addr)) 1917 goto out; 1918 if (ah->ar_hln != rcvif->if_sadl->sdl_alen) 1919 goto out; 1920 if (memcmp(tha, CLLADDR(rcvif->if_sadl), rcvif->if_sadl->sdl_alen)) 1921 goto out; 1922 memcpy(&srv_ip, ar_spa(ah), sizeof(srv_ip)); 1923 memcpy(&myip, ar_tpa(ah), sizeof(myip)); 1924 myip_initialized = 1; 1925 wake: /* Do wakeup every time in case it was missed. */ 1926 wakeup((void *)&myip); 1927 1928 out: 1929 m_put_rcvif(rcvif, &s); 1930 m_freem(m); 1931 } 1932 1933 /* 1934 * Send a RARP request for the ip address of the specified interface. 1935 * The request should be RFC 903-compliant. 1936 */ 1937 static void 1938 revarprequest(struct ifnet *ifp) 1939 { 1940 struct sockaddr sa; 1941 struct mbuf *m; 1942 struct arphdr *ah; 1943 void *tha; 1944 1945 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 1946 return; 1947 MCLAIM(m, &arpdomain.dom_mowner); 1948 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) + 1949 2*ifp->if_addrlen; 1950 m->m_pkthdr.len = m->m_len; 1951 m_align(m, m->m_len); 1952 ah = mtod(m, struct arphdr *); 1953 memset(ah, 0, m->m_len); 1954 ah->ar_pro = htons(ETHERTYPE_IP); 1955 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 1956 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 1957 ah->ar_op = htons(ARPOP_REVREQUEST); 1958 1959 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1960 tha = ar_tha(ah); 1961 if (tha == NULL) { 1962 m_free(m); 1963 return; 1964 } 1965 memcpy(tha, CLLADDR(ifp->if_sadl), ah->ar_hln); 1966 1967 sa.sa_family = AF_ARP; 1968 sa.sa_len = 2; 1969 m->m_flags |= M_BCAST; 1970 1971 if_output_lock(ifp, ifp, m, &sa, NULL); 1972 } 1973 1974 /* 1975 * RARP for the ip address of the specified interface, but also 1976 * save the ip address of the server that sent the answer. 1977 * Timeout if no response is received. 1978 */ 1979 int 1980 revarpwhoarewe(struct ifnet *ifp, struct in_addr *serv_in, 1981 struct in_addr *clnt_in) 1982 { 1983 int result, count = 20; 1984 1985 myip_initialized = 0; 1986 myip_ifp = ifp; 1987 1988 revarp_in_progress = 1; 1989 while (count--) { 1990 revarprequest(ifp); 1991 result = tsleep((void *)&myip, PSOCK, "revarp", hz/2); 1992 if (result != EWOULDBLOCK) 1993 break; 1994 } 1995 revarp_in_progress = 0; 1996 1997 if (!myip_initialized) 1998 return ENETUNREACH; 1999 2000 memcpy(serv_in, &srv_ip, sizeof(*serv_in)); 2001 memcpy(clnt_in, &myip, sizeof(*clnt_in)); 2002 return 0; 2003 } 2004 2005 void 2006 arp_stat_add(int type, uint64_t count) 2007 { 2008 ARP_STATADD(type, count); 2009 } 2010 2011 static int 2012 sysctl_net_inet_arp_stats(SYSCTLFN_ARGS) 2013 { 2014 2015 return NETSTAT_SYSCTL(arpstat_percpu, ARP_NSTATS); 2016 } 2017 2018 static void 2019 sysctl_net_inet_arp_setup(struct sysctllog **clog) 2020 { 2021 const struct sysctlnode *node; 2022 2023 sysctl_createv(clog, 0, NULL, NULL, 2024 CTLFLAG_PERMANENT, 2025 CTLTYPE_NODE, "inet", NULL, 2026 NULL, 0, NULL, 0, 2027 CTL_NET, PF_INET, CTL_EOL); 2028 sysctl_createv(clog, 0, NULL, &node, 2029 CTLFLAG_PERMANENT, 2030 CTLTYPE_NODE, "arp", 2031 SYSCTL_DESCR("Address Resolution Protocol"), 2032 NULL, 0, NULL, 0, 2033 CTL_NET, PF_INET, CTL_CREATE, CTL_EOL); 2034 2035 sysctl_createv(clog, 0, NULL, NULL, 2036 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2037 CTLTYPE_INT, "nd_delay", 2038 SYSCTL_DESCR("First probe delay time"), 2039 NULL, 0, &arp_nd_domain.nd_delay, 0, 2040 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2041 sysctl_createv(clog, 0, NULL, NULL, 2042 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2043 CTLTYPE_INT, "nd_bmaxtries", 2044 SYSCTL_DESCR("Number of broadcast discovery attempts"), 2045 NULL, 0, &arp_nd_domain.nd_mmaxtries, 0, 2046 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2047 sysctl_createv(clog, 0, NULL, NULL, 2048 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2049 CTLTYPE_INT, "nd_umaxtries", 2050 SYSCTL_DESCR("Number of unicast discovery attempts"), 2051 NULL, 0, &arp_nd_domain.nd_umaxtries, 0, 2052 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2053 sysctl_createv(clog, 0, NULL, NULL, 2054 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2055 CTLTYPE_INT, "nd_reachable", 2056 SYSCTL_DESCR("Reachable time"), 2057 NULL, 0, &arp_reachable, 0, 2058 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2059 sysctl_createv(clog, 0, NULL, NULL, 2060 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2061 CTLTYPE_INT, "nd_retrans", 2062 SYSCTL_DESCR("Retransmission time"), 2063 NULL, 0, &arp_retrans, 0, 2064 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2065 sysctl_createv(clog, 0, NULL, NULL, 2066 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2067 CTLTYPE_INT, "nd_nud", 2068 SYSCTL_DESCR("Perform neighbour unreachability detection"), 2069 NULL, 0, &arp_perform_nud, 0, 2070 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2071 sysctl_createv(clog, 0, NULL, NULL, 2072 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2073 CTLTYPE_INT, "nd_maxnudhint", 2074 SYSCTL_DESCR("Maximum neighbor unreachable hint count"), 2075 NULL, 0, &arp_nd_domain.nd_maxnudhint, 0, 2076 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2077 sysctl_createv(clog, 0, NULL, NULL, 2078 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2079 CTLTYPE_INT, "maxqueuelen", 2080 SYSCTL_DESCR("max packet queue len for a unresolved ARP"), 2081 NULL, 1, &arp_nd_domain.nd_maxqueuelen, 0, 2082 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2083 2084 sysctl_createv(clog, 0, NULL, NULL, 2085 CTLFLAG_PERMANENT, 2086 CTLTYPE_STRUCT, "stats", 2087 SYSCTL_DESCR("ARP statistics"), 2088 sysctl_net_inet_arp_stats, 0, NULL, 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_movements", 2094 SYSCTL_DESCR("log ARP replies from MACs different than" 2095 " the one in the cache"), 2096 NULL, 0, &log_movements, 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, "log_permanent_modify", 2102 SYSCTL_DESCR("log ARP replies from MACs different than" 2103 " the one in the permanent arp entry"), 2104 NULL, 0, &log_permanent_modify, 0, 2105 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2106 2107 sysctl_createv(clog, 0, NULL, NULL, 2108 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2109 CTLTYPE_INT, "log_wrong_iface", 2110 SYSCTL_DESCR("log ARP packets arriving on the wrong" 2111 " interface"), 2112 NULL, 0, &log_wrong_iface, 0, 2113 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2114 2115 sysctl_createv(clog, 0, NULL, NULL, 2116 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2117 CTLTYPE_INT, "debug", 2118 SYSCTL_DESCR("Enable ARP DAD debug output"), 2119 NULL, 0, &arp_debug, 0, 2120 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2121 } 2122 2123 #endif /* INET */ 2124
Indexes created Mon Aug 10 00:24:53 UTC 2026