1 /* $NetBSD: if_arp.c,v 1.320 2026/05/29 02:45:14 ozaki-r 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 1.320 2026/05/29 02:45:14 ozaki-r 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 in_arpinput(m); 738 continue; 739 default: 740 ARP_STATINC(ARP_STAT_RCVBADPROTO); 741 goto free; 742 } 743 744 badlen: 745 ARP_STATINC(ARP_STAT_RCVBADLEN); 746 free: 747 m_freem(m); 748 } 749 SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 750 return; /* XXX gcc */ 751 } 752 753 /* 754 * ARP for Internet protocols on 10 Mb/s Ethernet. Algorithm is that given in 755 * RFC 826. In addition, a sanity check is performed on the sender protocol 756 * address, to catch impersonators. 757 * 758 * We no longer handle negotiations for use of trailer protocol: formerly, ARP 759 * replied for protocol type ETHERTYPE_TRAIL sent along with IP replies if we 760 * wanted trailers sent to us, and also sent them in response to IP replies. 761 * This allowed either end to announce the desire to receive trailer packets. 762 * 763 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, but 764 * formerly didn't normally send requests. 765 */ 766 static void 767 in_arpinput(struct mbuf *m) 768 { 769 struct arphdr *ah; 770 struct ifnet *ifp, *rcvif = NULL; 771 struct llentry *la = NULL; 772 struct in_ifaddr *ia = NULL; 773 #if NBRIDGE > 0 774 struct in_ifaddr *bridge_ia = NULL; 775 #endif 776 #if NCARP > 0 777 uint32_t count = 0, index = 0; 778 #endif 779 struct sockaddr sa; 780 struct in_addr isaddr, itaddr, myaddr; 781 int op, rt_cmd, new_state = 0; 782 void *tha; 783 net_stat_ref_t arps; 784 struct psref psref, psref_ia; 785 int s; 786 char ipbuf[INET_ADDRSTRLEN]; 787 bool find_source, do_dad; 788 789 if (__predict_false(m_makewritable(&m, 0, m->m_pkthdr.len, M_DONTWAIT))) 790 goto out; 791 ah = mtod(m, struct arphdr *); 792 op = ntohs(ah->ar_op); 793 794 if (ah->ar_pln != sizeof(struct in_addr)) 795 goto out; 796 797 /* RFC5227 2.4 says any of the host's own interface addresses 798 * are not conflicting ARP packets. */ 799 ifp = if_get_bylla(ar_sha(ah), ah->ar_hln, &psref); 800 if (ifp) { 801 /* it's from me, ignore it. */ 802 if_put(ifp, &psref); 803 ARP_STATINC(ARP_STAT_RCVLOCALSHA); 804 goto out; 805 } 806 807 rcvif = ifp = m_get_rcvif_psref(m, &psref); 808 if (__predict_false(rcvif == NULL)) 809 goto out; 810 if (rcvif->if_flags & IFF_NOARP) 811 goto out; 812 813 memcpy(&isaddr, ar_spa(ah), sizeof(isaddr)); 814 memcpy(&itaddr, ar_tpa(ah), sizeof(itaddr)); 815 816 if (m->m_flags & (M_BCAST|M_MCAST)) 817 ARP_STATINC(ARP_STAT_RCVMCAST); 818 819 /* 820 * Search for a matching interface address 821 * or any address on the interface to use 822 * as a dummy address in the rest of this function. 823 * 824 * First try and find the source address for early 825 * duplicate address detection. 826 */ 827 if (in_nullhost(isaddr)) { 828 if (in_nullhost(itaddr)) /* very bogus ARP */ 829 goto out; 830 find_source = false; 831 myaddr = itaddr; 832 } else { 833 find_source = true; 834 myaddr = isaddr; 835 } 836 s = pserialize_read_enter(); 837 again: 838 IN_ADDRHASH_READER_FOREACH(ia, myaddr.s_addr) { 839 if (!in_hosteq(ia->ia_addr.sin_addr, myaddr)) 840 continue; 841 #if NCARP > 0 842 if (ia->ia_ifp->if_type == IFT_CARP && 843 ((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) == 844 (IFF_UP|IFF_RUNNING))) { 845 index++; 846 /* XXX: ar_hln? */ 847 if (ia->ia_ifp == rcvif && (ah->ar_hln >= 6) && 848 carp_iamatch(ia, ar_sha(ah), 849 &count, index)) { 850 break; 851 } 852 } else 853 #endif 854 if (ia->ia_ifp == rcvif) 855 break; 856 #if NBRIDGE > 0 857 /* 858 * If the interface we received the packet on 859 * is part of a bridge, check to see if we need 860 * to "bridge" the packet to ourselves at this 861 * layer. Note we still prefer a perfect match, 862 * but allow this weaker match if necessary. 863 */ 864 if (rcvif->if_bridge != NULL && 865 rcvif->if_bridge == ia->ia_ifp->if_bridge) 866 bridge_ia = ia; 867 #endif 868 } 869 870 #if NBRIDGE > 0 871 if (ia == NULL && bridge_ia != NULL) { 872 ia = bridge_ia; 873 m_put_rcvif_psref(rcvif, &psref); 874 rcvif = NULL; 875 /* FIXME */ 876 ifp = bridge_ia->ia_ifp; 877 } 878 #endif 879 880 /* If we failed to find the source address then find 881 * the target address. */ 882 if (ia == NULL && find_source && !in_nullhost(itaddr)) { 883 find_source = false; 884 myaddr = itaddr; 885 goto again; 886 } 887 888 if (ia != NULL) 889 ia4_acquire(ia, &psref_ia); 890 pserialize_read_exit(s); 891 892 if (ah->ar_hln != ifp->if_addrlen) { 893 ARP_STATINC(ARP_STAT_RCVBADLEN); 894 log(LOG_WARNING, 895 "arp from %s: addr len: new %d, i/f %d (ignored)\n", 896 IN_PRINT(ipbuf, &isaddr), ah->ar_hln, ifp->if_addrlen); 897 goto out; 898 } 899 900 /* Only do DaD if we have a matching address. */ 901 do_dad = (ia != NULL); 902 903 if (ia == NULL) { 904 ia = in_get_ia_on_iface_psref(isaddr, rcvif, &psref_ia); 905 if (ia == NULL) { 906 ia = in_get_ia_from_ifp_psref(ifp, &psref_ia); 907 if (ia == NULL) { 908 ARP_STATINC(ARP_STAT_RCVNOINT); 909 goto out; 910 } 911 } 912 } 913 914 myaddr = ia->ia_addr.sin_addr; 915 916 /* XXX checks for bridge case? */ 917 if (!memcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 918 ARP_STATINC(ARP_STAT_RCVBCASTSHA); 919 log(LOG_ERR, 920 "%s: arp: link address is broadcast for IP address %s!\n", 921 ifp->if_xname, IN_PRINT(ipbuf, &isaddr)); 922 goto out; 923 } 924 925 /* 926 * If the source IP address is zero, this is an RFC 5227 ARP probe 927 */ 928 if (in_nullhost(isaddr)) 929 ARP_STATINC(ARP_STAT_RCVZEROSPA); 930 else if (in_hosteq(isaddr, myaddr)) { 931 ARP_STATINC(ARP_STAT_RCVLOCALSPA); 932 /* This is the original behavior prior to supporting IPv4 DAD */ 933 if (!ip_dad_enabled()) { 934 char llabuf[LLA_ADDRSTRLEN]; 935 log(LOG_ERR, 936 "duplicate IP address %s sent from link address %s\n", 937 IN_PRINT(ipbuf, &isaddr), 938 lla_snprintf(llabuf, sizeof(llabuf), ar_sha(ah), 939 ah->ar_hln)); 940 itaddr = myaddr; 941 goto reply; 942 } 943 } 944 945 if (in_nullhost(itaddr)) 946 ARP_STATINC(ARP_STAT_RCVZEROTPA); 947 948 /* 949 * DAD check, RFC 5227. 950 * ARP sender hardware address must match the interface 951 * address of the interface sending the packet. 952 * Collision on sender address is always a duplicate. 953 * Collision on target address is only a duplicate 954 * IF the sender address is the null host (ie a DAD probe) 955 * AND the message was broadcast 956 * AND our address is either tentative or duplicated 957 * If it was unicast then it's a valid Unicast Poll from RFC 1122. 958 */ 959 if (ip_dad_enabled() && do_dad && 960 (in_hosteq(isaddr, myaddr) || 961 (in_nullhost(isaddr) && in_hosteq(itaddr, myaddr) && 962 m->m_flags & M_BCAST && 963 ia->ia4_flags & (IN_IFF_TENTATIVE | IN_IFF_DUPLICATED)))) 964 { 965 struct m_tag *mtag; 966 967 mtag = m_tag_find(m, PACKET_TAG_ETHERNET_SRC); 968 if (mtag == NULL || (ah->ar_hln == ETHER_ADDR_LEN && 969 memcmp(mtag + 1, ar_sha(ah), ah->ar_hln) == 0)) { 970 struct sockaddr_dl sdl, *sdlp; 971 972 sdlp = sockaddr_dl_init(&sdl, sizeof(sdl), 973 ifp->if_index, ifp->if_type, 974 NULL, 0, ar_sha(ah), ah->ar_hln); 975 arp_dad_duplicated((struct ifaddr *)ia, sdlp); 976 goto out; 977 } 978 } 979 980 /* 981 * If the target IP address is zero, ignore the packet. 982 * This prevents the code below from trying to answer 983 * when we are using IP address zero (booting). 984 */ 985 if (in_nullhost(itaddr)) 986 goto out; 987 988 if (in_nullhost(isaddr)) 989 goto reply; 990 991 if (in_hosteq(itaddr, myaddr)) 992 la = arpcreate(ifp, &isaddr, NULL, 1); 993 else 994 la = arplookup(ifp, &isaddr, NULL, 1); 995 if (la == NULL) 996 goto reply; 997 998 if ((la->la_flags & LLE_VALID) && 999 memcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) 1000 { 1001 char llabuf[LLA_ADDRSTRLEN], *llastr; 1002 1003 llastr = lla_snprintf(llabuf, sizeof(llabuf), 1004 ar_sha(ah), ah->ar_hln); 1005 1006 if (la->la_flags & LLE_STATIC) { 1007 ARP_STATINC(ARP_STAT_RCVOVERPERM); 1008 if (!log_permanent_modify) 1009 goto out; 1010 log(LOG_INFO, 1011 "%s tried to overwrite permanent arp info" 1012 " for %s\n", llastr, IN_PRINT(ipbuf, &isaddr)); 1013 goto out; 1014 } else if (la->lle_tbl->llt_ifp != ifp) { 1015 /* XXX should not happen? */ 1016 ARP_STATINC(ARP_STAT_RCVOVERINT); 1017 if (!log_wrong_iface) 1018 goto out; 1019 log(LOG_INFO, 1020 "%s on %s tried to overwrite " 1021 "arp info for %s on %s\n", 1022 llastr, 1023 ifp->if_xname, IN_PRINT(ipbuf, &isaddr), 1024 la->lle_tbl->llt_ifp->if_xname); 1025 goto out; 1026 } else { 1027 ARP_STATINC(ARP_STAT_RCVOVER); 1028 if (log_movements) 1029 log(LOG_INFO, "arp info overwritten " 1030 "for %s by %s\n", 1031 IN_PRINT(ipbuf, &isaddr), llastr); 1032 } 1033 rt_cmd = RTM_CHANGE; 1034 new_state = ND_LLINFO_STALE; 1035 } else { 1036 if (op == ARPOP_REPLY && in_hosteq(itaddr, myaddr)) { 1037 /* This was a solicited ARP reply. */ 1038 la->ln_byhint = 0; 1039 new_state = ND_LLINFO_REACHABLE; 1040 } else if (op == ARPOP_REQUEST && 1041 (la->ln_state == ND_LLINFO_NOSTATE || 1042 la->ln_state == ND_LLINFO_INCOMPLETE)) { 1043 /* 1044 * If an ARP request comes but there is no entry 1045 * and a new one has been created or an entry exists 1046 * but incomplete, make it stale to allow to send 1047 * packets to the requester without an ARP resolution. 1048 */ 1049 la->ln_byhint = 0; 1050 new_state = ND_LLINFO_STALE; 1051 } 1052 rt_cmd = la->la_flags & LLE_VALID ? 0 : RTM_ADD; 1053 } 1054 1055 KASSERT(ifp->if_sadl->sdl_alen == ifp->if_addrlen); 1056 1057 KASSERT(sizeof(la->ll_addr) >= ifp->if_addrlen); 1058 memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen); 1059 la->la_flags |= LLE_VALID; 1060 la->la_flags &= ~LLE_UNRESOLVED; 1061 la->ln_asked = 0; 1062 if (new_state != 0) { 1063 la->ln_state = new_state; 1064 1065 if (new_state != ND_LLINFO_REACHABLE || 1066 !(la->la_flags & LLE_STATIC)) 1067 { 1068 int timer = ND_TIMER_GC; 1069 1070 if (new_state == ND_LLINFO_REACHABLE) 1071 timer = ND_TIMER_REACHABLE; 1072 nd_set_timer(la, timer); 1073 } 1074 } 1075 1076 if (rt_cmd != 0) { 1077 struct sockaddr_in sin; 1078 1079 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 1080 rt_clonedmsg(rt_cmd, NULL, sintosa(&sin), ar_sha(ah), ifp); 1081 } 1082 1083 if (la->la_hold != NULL) { 1084 int n = la->la_numheld; 1085 struct mbuf *m_hold, *m_hold_next; 1086 struct sockaddr_in sin; 1087 1088 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 1089 1090 m_hold = la->la_hold; 1091 la->la_hold = NULL; 1092 la->la_numheld = 0; 1093 /* 1094 * We have to unlock here because if_output would call 1095 * arpresolve 1096 */ 1097 LLE_WUNLOCK(la); 1098 ARP_STATADD(ARP_STAT_DFRSENT, n); 1099 ARP_STATADD(ARP_STAT_DFRTOTAL, n); 1100 for (; m_hold != NULL; m_hold = m_hold_next) { 1101 m_hold_next = m_hold->m_nextpkt; 1102 m_hold->m_nextpkt = NULL; 1103 if_output_lock(ifp, ifp, m_hold, sintosa(&sin), NULL); 1104 } 1105 } else 1106 LLE_WUNLOCK(la); 1107 la = NULL; 1108 1109 reply: 1110 if (la != NULL) { 1111 LLE_WUNLOCK(la); 1112 la = NULL; 1113 } 1114 if (op != ARPOP_REQUEST) { 1115 if (op == ARPOP_REPLY) 1116 ARP_STATINC(ARP_STAT_RCVREPLY); 1117 goto out; 1118 } 1119 ARP_STATINC(ARP_STAT_RCVREQUEST); 1120 if (in_hosteq(itaddr, myaddr)) { 1121 /* If our address is unusable, don't reply */ 1122 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) 1123 goto out; 1124 /* I am the target */ 1125 tha = ar_tha(ah); 1126 if (tha) 1127 memcpy(tha, ar_sha(ah), ah->ar_hln); 1128 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1129 } else { 1130 /* Proxy ARP */ 1131 struct llentry *lle = NULL; 1132 struct sockaddr_in sin; 1133 1134 #if NCARP > 0 1135 if (ifp->if_type == IFT_CARP) { 1136 struct ifnet *_rcvif = m_get_rcvif(m, &s); 1137 int iftype = 0; 1138 if (__predict_true(_rcvif != NULL)) 1139 iftype = _rcvif->if_type; 1140 m_put_rcvif(_rcvif, &s); 1141 if (iftype != IFT_CARP) 1142 goto out; 1143 } 1144 #endif 1145 1146 tha = ar_tha(ah); 1147 1148 sockaddr_in_init(&sin, &itaddr, 0); 1149 1150 IF_AFDATA_RLOCK(ifp); 1151 lle = lla_lookup(LLTABLE(ifp), 0, (struct sockaddr *)&sin); 1152 IF_AFDATA_RUNLOCK(ifp); 1153 1154 if ((lle != NULL) && (lle->la_flags & LLE_PUB)) { 1155 if (tha) 1156 memcpy(tha, ar_sha(ah), ah->ar_hln); 1157 memcpy(ar_sha(ah), &lle->ll_addr, ah->ar_hln); 1158 LLE_RUNLOCK(lle); 1159 } else { 1160 if (lle != NULL) 1161 LLE_RUNLOCK(lle); 1162 goto out; 1163 } 1164 } 1165 ia4_release(ia, &psref_ia); 1166 1167 /* 1168 * XXX XXX: Here we're recycling the mbuf. But the mbuf could have 1169 * other mbufs in its chain, and just overwriting m->m_pkthdr.len 1170 * would be wrong in this case (the length becomes smaller than the 1171 * real chain size). 1172 * 1173 * This can theoretically cause bugs in the lower layers (drivers, 1174 * and L2encap), in some corner cases. 1175 */ 1176 memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); 1177 memcpy(ar_spa(ah), &itaddr, ah->ar_pln); 1178 ah->ar_op = htons(ARPOP_REPLY); 1179 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 1180 switch (ifp->if_type) { 1181 case IFT_IEEE1394: 1182 /* ieee1394 arp reply is broadcast */ 1183 m->m_flags &= ~M_MCAST; 1184 m->m_flags |= M_BCAST; 1185 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + ah->ar_hln; 1186 break; 1187 default: 1188 m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */ 1189 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); 1190 break; 1191 } 1192 m->m_pkthdr.len = m->m_len; 1193 m->m_pkthdr.csum_flags = 0; /* Clear any in-bound checksum flags. */ 1194 sa.sa_family = AF_ARP; 1195 sa.sa_len = 2; 1196 arps = ARP_STAT_GETREF(); 1197 _NET_STATINC_REF(arps, ARP_STAT_SNDTOTAL); 1198 _NET_STATINC_REF(arps, ARP_STAT_SNDREPLY); 1199 ARP_STAT_PUTREF(); 1200 if_output_lock(ifp, ifp, m, &sa, NULL); 1201 if (rcvif != NULL) 1202 m_put_rcvif_psref(rcvif, &psref); 1203 return; 1204 1205 out: 1206 if (la != NULL) 1207 LLE_WUNLOCK(la); 1208 if (ia != NULL) 1209 ia4_release(ia, &psref_ia); 1210 if (rcvif != NULL) 1211 m_put_rcvif_psref(rcvif, &psref); 1212 m_freem(m); 1213 } 1214 1215 /* 1216 * Lookup or a new address in arptab. 1217 */ 1218 struct llentry * 1219 arplookup(struct ifnet *ifp, const struct in_addr *addr, 1220 const struct sockaddr *sa, int wlock) 1221 { 1222 struct sockaddr_in sin; 1223 struct llentry *la; 1224 int flags = wlock ? LLE_EXCLUSIVE : 0; 1225 1226 if (sa == NULL) { 1227 KASSERT(addr != NULL); 1228 sockaddr_in_init(&sin, addr, 0); 1229 sa = sintocsa(&sin); 1230 } 1231 1232 IF_AFDATA_RLOCK(ifp); 1233 la = lla_lookup(LLTABLE(ifp), flags, sa); 1234 IF_AFDATA_RUNLOCK(ifp); 1235 1236 return la; 1237 } 1238 1239 static struct llentry * 1240 arpcreate(struct ifnet *ifp, const struct in_addr *addr, 1241 const struct sockaddr *sa, int wlock) 1242 { 1243 struct sockaddr_in sin; 1244 struct llentry *la; 1245 int flags = wlock ? LLE_EXCLUSIVE : 0; 1246 1247 if (sa == NULL) { 1248 KASSERT(addr != NULL); 1249 sockaddr_in_init(&sin, addr, 0); 1250 sa = sintocsa(&sin); 1251 } 1252 1253 la = arplookup(ifp, addr, sa, wlock); 1254 1255 if (la == NULL) { 1256 struct rtentry *rt; 1257 1258 rt = rtalloc1(sa, 0); 1259 IF_AFDATA_WLOCK(ifp); 1260 la = lla_create(LLTABLE(ifp), flags, sa, rt); 1261 IF_AFDATA_WUNLOCK(ifp); 1262 if (rt != NULL) 1263 rt_unref(rt); 1264 1265 if (la != NULL) 1266 la->ln_state = ND_LLINFO_NOSTATE; 1267 } 1268 1269 return la; 1270 } 1271 1272 int 1273 arpioctl(u_long cmd, void *data) 1274 { 1275 1276 return EOPNOTSUPP; 1277 } 1278 1279 void 1280 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1281 { 1282 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1283 1284 ifa->ifa_rtrequest = arp_rtrequest; 1285 ifa->ifa_flags |= RTF_CONNECTED; 1286 1287 /* ARP will handle DAD for this address. */ 1288 if (in_nullhost(IA_SIN(ifa)->sin_addr)) { 1289 if (ia->ia_dad_stop != NULL) /* safety */ 1290 ia->ia_dad_stop(ifa); 1291 ia->ia_dad_start = NULL; 1292 ia->ia_dad_stop = NULL; 1293 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1294 } else { 1295 ia->ia_dad_start = arp_dad_start; 1296 ia->ia_dad_stop = arp_dad_stop; 1297 if (ia->ia4_flags & IN_IFF_TRYTENTATIVE && ip_dad_enabled()) 1298 ia->ia4_flags |= IN_IFF_TENTATIVE; 1299 else 1300 arpannounce1(ifa); 1301 } 1302 } 1303 1304 static bool 1305 arp_nud_enabled(__unused struct ifnet *ifp) 1306 { 1307 1308 return arp_perform_nud != 0; 1309 } 1310 1311 static unsigned int 1312 arp_llinfo_reachable(__unused struct ifnet *ifp) 1313 { 1314 1315 return arp_reachable; 1316 } 1317 1318 static unsigned int 1319 arp_llinfo_retrans(__unused struct ifnet *ifp) 1320 { 1321 1322 return arp_retrans; 1323 } 1324 1325 /* 1326 * Gets source address of the first packet in hold queue 1327 * and stores it in @src. 1328 * Returns pointer to @src (if hold queue is not empty) or NULL. 1329 */ 1330 static union l3addr * 1331 arp_llinfo_holdsrc(struct llentry *ln, union l3addr *src) 1332 { 1333 struct ip *ip; 1334 1335 if (ln == NULL || ln->ln_hold == NULL) 1336 return NULL; 1337 1338 /* 1339 * assuming every packet in ln_hold has the same IP header 1340 */ 1341 ip = mtod(ln->ln_hold, struct ip *); 1342 /* XXX pullup? */ 1343 if (sizeof(*ip) < ln->ln_hold->m_len) 1344 src->addr4 = ip->ip_src; 1345 else 1346 src = NULL; 1347 1348 return src; 1349 } 1350 1351 static void 1352 arp_llinfo_output(struct ifnet *ifp, __unused const union l3addr *daddr, 1353 const union l3addr *taddr, const uint8_t *tlladdr, 1354 const union l3addr *hsrc) 1355 { 1356 struct in_addr tip = taddr->addr4, sip = zeroin_addr; 1357 const uint8_t *slladdr = CLLADDR(ifp->if_sadl); 1358 1359 if (hsrc != NULL) { 1360 struct in_ifaddr *ia; 1361 struct psref psref; 1362 1363 ia = in_get_ia_on_iface_psref(hsrc->addr4, ifp, &psref); 1364 if (ia != NULL) { 1365 sip = hsrc->addr4; 1366 ia4_release(ia, &psref); 1367 } 1368 } 1369 1370 if (sip.s_addr == INADDR_ANY) { 1371 struct sockaddr_in dst; 1372 struct rtentry *rt; 1373 1374 sockaddr_in_init(&dst, &tip, 0); 1375 rt = rtalloc1(sintosa(&dst), 0); 1376 if (rt != NULL) { 1377 if (rt->rt_ifp == ifp && 1378 rt->rt_ifa != NULL && 1379 rt->rt_ifa->ifa_addr->sa_family == AF_INET) 1380 sip = satosin(rt->rt_ifa->ifa_addr)->sin_addr; 1381 rt_unref(rt); 1382 } 1383 if (sip.s_addr == INADDR_ANY) { 1384 char ipbuf[INET_ADDRSTRLEN]; 1385 1386 log(LOG_DEBUG, "%s: source can't be " 1387 "determined: dst=%s\n", __func__, 1388 IN_PRINT(ipbuf, &tip)); 1389 return; 1390 } 1391 } 1392 1393 arprequest(ifp, &sip, &tip, slladdr, tlladdr); 1394 } 1395 1396 1397 static void 1398 arp_llinfo_missed(struct ifnet *ifp, const union l3addr *taddr, 1399 __unused int16_t type, struct mbuf *m) 1400 { 1401 struct in_addr mdaddr = zeroin_addr; 1402 struct sockaddr_in dsin, tsin; 1403 struct sockaddr *sa; 1404 1405 if (m != NULL) { 1406 struct ip *ip = mtod(m, struct ip *); 1407 1408 if (sizeof(*ip) < m->m_len) 1409 mdaddr = ip->ip_src; 1410 1411 /* ip_input() will send ICMP_UNREACH_HOST, not us. */ 1412 m_freem(m); 1413 } 1414 1415 if (mdaddr.s_addr != INADDR_ANY) { 1416 sockaddr_in_init(&dsin, &mdaddr, 0); 1417 sa = sintosa(&dsin); 1418 } else 1419 sa = NULL; 1420 1421 sockaddr_in_init(&tsin, &taddr->addr4, 0); 1422 rt_clonedmsg(RTM_MISS, sa, sintosa(&tsin), NULL, ifp); 1423 } 1424 1425 static void 1426 arp_free(struct llentry *ln, int gc) 1427 { 1428 struct ifnet *ifp; 1429 1430 KASSERT(ln != NULL); 1431 LLE_WLOCK_ASSERT(ln); 1432 1433 ifp = ln->lle_tbl->llt_ifp; 1434 1435 if (ln->la_flags & LLE_VALID || gc) { 1436 struct sockaddr_in sin; 1437 const char *lladdr; 1438 1439 sockaddr_in_init(&sin, &ln->r_l3addr.addr4, 0); 1440 lladdr = ln->la_flags & LLE_VALID ? 1441 (const char *)&ln->ll_addr : NULL; 1442 rt_clonedmsg(RTM_DELETE, NULL, sintosa(&sin), lladdr, ifp); 1443 } 1444 1445 /* 1446 * Save to unlock. We still hold an extra reference and will not 1447 * free(9) in llentry_free() if someone else holds one as well. 1448 */ 1449 LLE_WUNLOCK(ln); 1450 IF_AFDATA_LOCK(ifp); 1451 LLE_WLOCK(ln); 1452 1453 lltable_free_entry(LLTABLE(ifp), ln); 1454 1455 IF_AFDATA_UNLOCK(ifp); 1456 } 1457 1458 /* 1459 * Upper-layer reachability hint for Neighbor Unreachability Detection. 1460 * 1461 * XXX cost-effective methods? 1462 */ 1463 void 1464 arp_nud_hint(struct rtentry *rt) 1465 { 1466 struct llentry *ln; 1467 struct ifnet *ifp; 1468 1469 if (rt == NULL) 1470 return; 1471 1472 ifp = rt->rt_ifp; 1473 ln = arplookup(ifp, NULL, rt_getkey(rt), 1); 1474 nd_nud_hint(ln); 1475 } 1476 1477 TAILQ_HEAD(dadq_head, dadq); 1478 struct dadq { 1479 TAILQ_ENTRY(dadq) dad_list; 1480 struct ifaddr *dad_ifa; 1481 int dad_count; /* max ARP to send */ 1482 int dad_arp_tcount; /* # of trials to send ARP */ 1483 int dad_arp_ocount; /* ARP sent so far */ 1484 int dad_arp_announce; /* max ARP announcements */ 1485 int dad_arp_acount; /* # of announcements */ 1486 struct callout dad_timer_ch; 1487 }; 1488 1489 static struct dadq_head dadq; 1490 static int dad_maxtry = 15; /* max # of *tries* to transmit DAD packet */ 1491 static kmutex_t arp_dad_lock; 1492 1493 static void 1494 arp_dad_init(void) 1495 { 1496 1497 TAILQ_INIT(&dadq); 1498 mutex_init(&arp_dad_lock, MUTEX_DEFAULT, IPL_NONE); 1499 } 1500 1501 static struct dadq * 1502 arp_dad_find(struct ifaddr *ifa) 1503 { 1504 struct dadq *dp; 1505 1506 KASSERT(mutex_owned(&arp_dad_lock)); 1507 1508 TAILQ_FOREACH(dp, &dadq, dad_list) { 1509 if (dp->dad_ifa == ifa) 1510 return dp; 1511 } 1512 return NULL; 1513 } 1514 1515 static void 1516 arp_dad_starttimer(struct dadq *dp, int ticks) 1517 { 1518 1519 callout_reset(&dp->dad_timer_ch, ticks, 1520 (void (*)(void *))arp_dad_timer, dp); 1521 } 1522 1523 static void 1524 arp_dad_stoptimer(struct dadq *dp) 1525 { 1526 1527 KASSERT(mutex_owned(&arp_dad_lock)); 1528 1529 TAILQ_REMOVE(&dadq, dp, dad_list); 1530 /* Tell the timer that dp is being destroyed. */ 1531 dp->dad_ifa = NULL; 1532 callout_halt(&dp->dad_timer_ch, &arp_dad_lock); 1533 } 1534 1535 static void 1536 arp_dad_destroytimer(struct dadq *dp) 1537 { 1538 1539 callout_destroy(&dp->dad_timer_ch); 1540 KASSERT(dp->dad_ifa == NULL); 1541 kmem_intr_free(dp, sizeof(*dp)); 1542 } 1543 1544 static void 1545 arp_dad_output(struct dadq *dp, struct ifaddr *ifa) 1546 { 1547 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1548 struct ifnet *ifp = ifa->ifa_ifp; 1549 struct in_addr sip; 1550 1551 dp->dad_arp_tcount++; 1552 if ((ifp->if_flags & IFF_UP) == 0) 1553 return; 1554 if ((ifp->if_flags & IFF_RUNNING) == 0) 1555 return; 1556 1557 dp->dad_arp_tcount = 0; 1558 dp->dad_arp_ocount++; 1559 1560 memset(&sip, 0, sizeof(sip)); 1561 arprequest(ifa->ifa_ifp, &sip, &ia->ia_addr.sin_addr, 1562 CLLADDR(ifa->ifa_ifp->if_sadl), NULL); 1563 } 1564 1565 /* 1566 * Start Duplicate Address Detection (DAD) for specified interface address. 1567 */ 1568 static void 1569 arp_dad_start(struct ifaddr *ifa) 1570 { 1571 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1572 struct dadq *dp; 1573 char ipbuf[INET_ADDRSTRLEN]; 1574 1575 /* 1576 * If we don't need DAD, don't do it. 1577 * - DAD is disabled 1578 */ 1579 if (!(ia->ia4_flags & IN_IFF_TENTATIVE)) { 1580 log(LOG_DEBUG, 1581 "%s: called with non-tentative address %s(%s)\n", __func__, 1582 IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1583 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1584 return; 1585 } 1586 if (!ip_dad_enabled()) { 1587 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1588 rt_addrmsg(RTM_NEWADDR, ifa); 1589 arpannounce1(ifa); 1590 return; 1591 } 1592 KASSERT(ifa->ifa_ifp != NULL); 1593 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) 1594 return; 1595 1596 dp = kmem_intr_alloc(sizeof(*dp), KM_NOSLEEP); 1597 1598 mutex_enter(&arp_dad_lock); 1599 if (arp_dad_find(ifa) != NULL) { 1600 mutex_exit(&arp_dad_lock); 1601 /* DAD already in progress */ 1602 if (dp != NULL) 1603 kmem_intr_free(dp, sizeof(*dp)); 1604 return; 1605 } 1606 1607 if (dp == NULL) { 1608 mutex_exit(&arp_dad_lock); 1609 log(LOG_ERR, "%s: memory allocation failed for %s(%s)\n", 1610 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1611 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1612 return; 1613 } 1614 1615 /* 1616 * Send ARP packet for DAD, ip_dad_count times. 1617 * Note that we must delay the first transmission. 1618 */ 1619 callout_init(&dp->dad_timer_ch, CALLOUT_MPSAFE); 1620 dp->dad_ifa = ifa; 1621 ifaref(ifa); /* just for safety */ 1622 dp->dad_count = ip_dad_count; 1623 dp->dad_arp_announce = 0; /* Will be set when starting to announce */ 1624 dp->dad_arp_acount = dp->dad_arp_ocount = dp->dad_arp_tcount = 0; 1625 TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list); 1626 1627 ARPLOG(LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1628 ARPLOGADDR(&ia->ia_addr.sin_addr)); 1629 1630 arp_dad_starttimer(dp, cprng_fast32() % (PROBE_WAIT * hz)); 1631 1632 mutex_exit(&arp_dad_lock); 1633 } 1634 1635 /* 1636 * terminate DAD unconditionally. used for address removals. 1637 */ 1638 static void 1639 arp_dad_stop(struct ifaddr *ifa) 1640 { 1641 struct dadq *dp; 1642 1643 mutex_enter(&arp_dad_lock); 1644 dp = arp_dad_find(ifa); 1645 if (dp == NULL) { 1646 mutex_exit(&arp_dad_lock); 1647 /* DAD wasn't started yet */ 1648 return; 1649 } 1650 1651 arp_dad_stoptimer(dp); 1652 1653 mutex_exit(&arp_dad_lock); 1654 1655 arp_dad_destroytimer(dp); 1656 ifafree(ifa); 1657 } 1658 1659 static void 1660 arp_dad_timer(struct dadq *dp) 1661 { 1662 struct ifaddr *ifa; 1663 struct in_ifaddr *ia; 1664 char ipbuf[INET_ADDRSTRLEN]; 1665 bool need_free = false; 1666 1667 KERNEL_LOCK_UNLESS_NET_MPSAFE(); 1668 mutex_enter(&arp_dad_lock); 1669 1670 ifa = dp->dad_ifa; 1671 if (ifa == NULL) { 1672 /* dp is being destroyed by someone. Do nothing. */ 1673 goto done; 1674 } 1675 1676 ia = (struct in_ifaddr *)ifa; 1677 if (ia->ia4_flags & IN_IFF_DUPLICATED) { 1678 log(LOG_ERR, "%s: called with duplicate 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 if ((ia->ia4_flags & IN_IFF_TENTATIVE) == 0 && dp->dad_arp_acount == 0) 1684 { 1685 log(LOG_ERR, "%s: called with non-tentative address %s(%s)\n", 1686 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1687 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1688 goto done; 1689 } 1690 1691 /* timeouted with IFF_{RUNNING,UP} check */ 1692 if (dp->dad_arp_tcount > dad_maxtry) { 1693 ARPLOG(LOG_INFO, "%s: could not run DAD, driver problem?\n", 1694 if_name(ifa->ifa_ifp)); 1695 1696 arp_dad_stoptimer(dp); 1697 need_free = true; 1698 goto done; 1699 } 1700 1701 /* Need more checks? */ 1702 if (dp->dad_arp_ocount < dp->dad_count) { 1703 int adelay; 1704 1705 /* 1706 * We have more ARP to go. Send ARP packet for DAD. 1707 */ 1708 arp_dad_output(dp, ifa); 1709 if (dp->dad_arp_ocount < dp->dad_count) 1710 adelay = (PROBE_MIN * hz) + 1711 (cprng_fast32() % 1712 ((PROBE_MAX * hz) - (PROBE_MIN * hz))); 1713 else 1714 adelay = ANNOUNCE_WAIT * hz; 1715 arp_dad_starttimer(dp, adelay); 1716 goto done; 1717 } else if (dp->dad_arp_acount == 0) { 1718 /* 1719 * We are done with DAD. 1720 * No duplicate address found. 1721 */ 1722 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1723 rt_addrmsg(RTM_NEWADDR, ifa); 1724 ARPLOG(LOG_DEBUG, 1725 "%s: DAD complete for %s - no duplicates found\n", 1726 if_name(ifa->ifa_ifp), ARPLOGADDR(&ia->ia_addr.sin_addr)); 1727 dp->dad_arp_announce = ANNOUNCE_NUM; 1728 goto announce; 1729 } else if (dp->dad_arp_acount < dp->dad_arp_announce) { 1730 announce: 1731 /* 1732 * Announce the address. 1733 */ 1734 arpannounce1(ifa); 1735 dp->dad_arp_acount++; 1736 if (dp->dad_arp_acount < dp->dad_arp_announce) { 1737 arp_dad_starttimer(dp, ANNOUNCE_INTERVAL * hz); 1738 goto done; 1739 } 1740 ARPLOG(LOG_DEBUG, 1741 "%s: ARP announcement complete for %s\n", 1742 if_name(ifa->ifa_ifp), ARPLOGADDR(&ia->ia_addr.sin_addr)); 1743 } 1744 1745 arp_dad_stoptimer(dp); 1746 need_free = true; 1747 done: 1748 mutex_exit(&arp_dad_lock); 1749 1750 if (need_free) { 1751 arp_dad_destroytimer(dp); 1752 KASSERT(ifa != NULL); 1753 ifafree(ifa); 1754 } 1755 1756 KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 1757 } 1758 1759 static void 1760 arp_dad_duplicated(struct ifaddr *ifa, const struct sockaddr_dl *from) 1761 { 1762 struct in_ifaddr *ia = ifatoia(ifa); 1763 struct ifnet *ifp = ifa->ifa_ifp; 1764 char ipbuf[INET_ADDRSTRLEN], llabuf[LLA_ADDRSTRLEN]; 1765 const char *iastr, *llastr; 1766 1767 iastr = IN_PRINT(ipbuf, &ia->ia_addr.sin_addr); 1768 if (__predict_false(from == NULL)) 1769 llastr = NULL; 1770 else 1771 llastr = lla_snprintf(llabuf, sizeof(llabuf), 1772 CLLADDR(from), from->sdl_alen); 1773 1774 if (ia->ia4_flags & (IN_IFF_TENTATIVE|IN_IFF_DUPLICATED)) { 1775 log(LOG_ERR, 1776 "%s: DAD duplicate address %s from %s\n", 1777 if_name(ifp), iastr, llastr); 1778 } else if (ia->ia_dad_defended == 0 || 1779 ia->ia_dad_defended < time_uptime - DEFEND_INTERVAL) { 1780 ia->ia_dad_defended = time_uptime; 1781 arpannounce1(ifa); 1782 log(LOG_ERR, 1783 "%s: DAD defended address %s from %s\n", 1784 if_name(ifp), iastr, llastr); 1785 return; 1786 } else { 1787 /* If DAD is disabled, just report the duplicate. */ 1788 if (!ip_dad_enabled()) { 1789 log(LOG_ERR, 1790 "%s: DAD ignoring duplicate address %s from %s\n", 1791 if_name(ifp), iastr, llastr); 1792 return; 1793 } 1794 log(LOG_ERR, 1795 "%s: DAD defence failed for %s from %s\n", 1796 if_name(ifp), iastr, llastr); 1797 } 1798 1799 arp_dad_stop(ifa); 1800 1801 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1802 if ((ia->ia4_flags & IN_IFF_DUPLICATED) == 0) { 1803 ia->ia4_flags |= IN_IFF_DUPLICATED; 1804 /* Inform the routing socket of the duplicate address */ 1805 rt_addrmsg_src(RTM_NEWADDR, ifa, (const struct sockaddr *)from); 1806 } 1807 } 1808 1809 /* 1810 * Called from 10 Mb/s Ethernet interrupt handlers 1811 * when ether packet type ETHERTYPE_REVARP 1812 * is received. Common length and type checks are done here, 1813 * then the protocol-specific routine is called. 1814 */ 1815 void 1816 revarpinput(struct mbuf *m) 1817 { 1818 struct arphdr *ar; 1819 int arplen; 1820 1821 arplen = sizeof(struct arphdr); 1822 if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL) 1823 return; 1824 ar = mtod(m, struct arphdr *); 1825 1826 if (ntohs(ar->ar_hrd) == ARPHRD_IEEE1394) { 1827 goto out; 1828 } 1829 1830 arplen = sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln); 1831 if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL) 1832 return; 1833 ar = mtod(m, struct arphdr *); 1834 1835 switch (ntohs(ar->ar_pro)) { 1836 case ETHERTYPE_IP: 1837 case ETHERTYPE_IPTRAILERS: 1838 in_revarpinput(m); 1839 return; 1840 1841 default: 1842 break; 1843 } 1844 1845 out: 1846 m_freem(m); 1847 } 1848 1849 /* 1850 * RARP for Internet protocols on 10 Mb/s Ethernet. 1851 * Algorithm is that given in RFC 903. 1852 * We are only using for bootstrap purposes to get an ip address for one of 1853 * our interfaces. Thus we support no user-interface. 1854 * 1855 * Since the contents of the RARP reply are specific to the interface that 1856 * sent the request, this code must ensure that they are properly associated. 1857 * 1858 * Note: also supports ARP via RARP packets, per the RFC. 1859 */ 1860 void 1861 in_revarpinput(struct mbuf *m) 1862 { 1863 struct arphdr *ah; 1864 void *tha; 1865 int op; 1866 struct ifnet *rcvif; 1867 int s; 1868 1869 ah = mtod(m, struct arphdr *); 1870 op = ntohs(ah->ar_op); 1871 1872 rcvif = m_get_rcvif(m, &s); 1873 if (__predict_false(rcvif == NULL)) 1874 goto out; 1875 if (rcvif->if_flags & IFF_NOARP) 1876 goto out; 1877 1878 switch (rcvif->if_type) { 1879 case IFT_IEEE1394: 1880 /* ARP without target hardware address is not supported */ 1881 goto out; 1882 default: 1883 break; 1884 } 1885 1886 switch (op) { 1887 case ARPOP_REQUEST: 1888 case ARPOP_REPLY: /* per RFC */ 1889 m_put_rcvif(rcvif, &s); 1890 in_arpinput(m); 1891 return; 1892 case ARPOP_REVREPLY: 1893 break; 1894 case ARPOP_REVREQUEST: /* handled by rarpd(8) */ 1895 default: 1896 goto out; 1897 } 1898 if (!revarp_in_progress) 1899 goto out; 1900 if (rcvif != myip_ifp) /* !same interface */ 1901 goto out; 1902 if (myip_initialized) 1903 goto wake; 1904 tha = ar_tha(ah); 1905 if (tha == NULL) 1906 goto out; 1907 if (ah->ar_pln != sizeof(struct in_addr)) 1908 goto out; 1909 if (ah->ar_hln != rcvif->if_sadl->sdl_alen) 1910 goto out; 1911 if (memcmp(tha, CLLADDR(rcvif->if_sadl), rcvif->if_sadl->sdl_alen)) 1912 goto out; 1913 memcpy(&srv_ip, ar_spa(ah), sizeof(srv_ip)); 1914 memcpy(&myip, ar_tpa(ah), sizeof(myip)); 1915 myip_initialized = 1; 1916 wake: /* Do wakeup every time in case it was missed. */ 1917 wakeup((void *)&myip); 1918 1919 out: 1920 m_put_rcvif(rcvif, &s); 1921 m_freem(m); 1922 } 1923 1924 /* 1925 * Send a RARP request for the ip address of the specified interface. 1926 * The request should be RFC 903-compliant. 1927 */ 1928 static void 1929 revarprequest(struct ifnet *ifp) 1930 { 1931 struct sockaddr sa; 1932 struct mbuf *m; 1933 struct arphdr *ah; 1934 void *tha; 1935 1936 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 1937 return; 1938 MCLAIM(m, &arpdomain.dom_mowner); 1939 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) + 1940 2*ifp->if_addrlen; 1941 m->m_pkthdr.len = m->m_len; 1942 m_align(m, m->m_len); 1943 ah = mtod(m, struct arphdr *); 1944 memset(ah, 0, m->m_len); 1945 ah->ar_pro = htons(ETHERTYPE_IP); 1946 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 1947 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 1948 ah->ar_op = htons(ARPOP_REVREQUEST); 1949 1950 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1951 tha = ar_tha(ah); 1952 if (tha == NULL) { 1953 m_free(m); 1954 return; 1955 } 1956 memcpy(tha, CLLADDR(ifp->if_sadl), ah->ar_hln); 1957 1958 sa.sa_family = AF_ARP; 1959 sa.sa_len = 2; 1960 m->m_flags |= M_BCAST; 1961 1962 if_output_lock(ifp, ifp, m, &sa, NULL); 1963 } 1964 1965 /* 1966 * RARP for the ip address of the specified interface, but also 1967 * save the ip address of the server that sent the answer. 1968 * Timeout if no response is received. 1969 */ 1970 int 1971 revarpwhoarewe(struct ifnet *ifp, struct in_addr *serv_in, 1972 struct in_addr *clnt_in) 1973 { 1974 int result, count = 20; 1975 1976 myip_initialized = 0; 1977 myip_ifp = ifp; 1978 1979 revarp_in_progress = 1; 1980 while (count--) { 1981 revarprequest(ifp); 1982 result = tsleep((void *)&myip, PSOCK, "revarp", hz/2); 1983 if (result != EWOULDBLOCK) 1984 break; 1985 } 1986 revarp_in_progress = 0; 1987 1988 if (!myip_initialized) 1989 return ENETUNREACH; 1990 1991 memcpy(serv_in, &srv_ip, sizeof(*serv_in)); 1992 memcpy(clnt_in, &myip, sizeof(*clnt_in)); 1993 return 0; 1994 } 1995 1996 void 1997 arp_stat_add(int type, uint64_t count) 1998 { 1999 ARP_STATADD(type, count); 2000 } 2001 2002 static int 2003 sysctl_net_inet_arp_stats(SYSCTLFN_ARGS) 2004 { 2005 2006 return NETSTAT_SYSCTL(arpstat_percpu, ARP_NSTATS); 2007 } 2008 2009 static void 2010 sysctl_net_inet_arp_setup(struct sysctllog **clog) 2011 { 2012 const struct sysctlnode *node; 2013 2014 sysctl_createv(clog, 0, NULL, NULL, 2015 CTLFLAG_PERMANENT, 2016 CTLTYPE_NODE, "inet", NULL, 2017 NULL, 0, NULL, 0, 2018 CTL_NET, PF_INET, CTL_EOL); 2019 sysctl_createv(clog, 0, NULL, &node, 2020 CTLFLAG_PERMANENT, 2021 CTLTYPE_NODE, "arp", 2022 SYSCTL_DESCR("Address Resolution Protocol"), 2023 NULL, 0, NULL, 0, 2024 CTL_NET, PF_INET, CTL_CREATE, CTL_EOL); 2025 2026 sysctl_createv(clog, 0, NULL, NULL, 2027 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2028 CTLTYPE_INT, "nd_delay", 2029 SYSCTL_DESCR("First probe delay time"), 2030 NULL, 0, &arp_nd_domain.nd_delay, 0, 2031 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2032 sysctl_createv(clog, 0, NULL, NULL, 2033 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2034 CTLTYPE_INT, "nd_bmaxtries", 2035 SYSCTL_DESCR("Number of broadcast discovery attempts"), 2036 NULL, 0, &arp_nd_domain.nd_mmaxtries, 0, 2037 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2038 sysctl_createv(clog, 0, NULL, NULL, 2039 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2040 CTLTYPE_INT, "nd_umaxtries", 2041 SYSCTL_DESCR("Number of unicast discovery attempts"), 2042 NULL, 0, &arp_nd_domain.nd_umaxtries, 0, 2043 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2044 sysctl_createv(clog, 0, NULL, NULL, 2045 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2046 CTLTYPE_INT, "nd_reachable", 2047 SYSCTL_DESCR("Reachable time"), 2048 NULL, 0, &arp_reachable, 0, 2049 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2050 sysctl_createv(clog, 0, NULL, NULL, 2051 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2052 CTLTYPE_INT, "nd_retrans", 2053 SYSCTL_DESCR("Retransmission time"), 2054 NULL, 0, &arp_retrans, 0, 2055 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2056 sysctl_createv(clog, 0, NULL, NULL, 2057 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2058 CTLTYPE_INT, "nd_nud", 2059 SYSCTL_DESCR("Perform neighbour unreachability detection"), 2060 NULL, 0, &arp_perform_nud, 0, 2061 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2062 sysctl_createv(clog, 0, NULL, NULL, 2063 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2064 CTLTYPE_INT, "nd_maxnudhint", 2065 SYSCTL_DESCR("Maximum neighbor unreachable hint count"), 2066 NULL, 0, &arp_nd_domain.nd_maxnudhint, 0, 2067 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2068 sysctl_createv(clog, 0, NULL, NULL, 2069 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2070 CTLTYPE_INT, "maxqueuelen", 2071 SYSCTL_DESCR("max packet queue len for a unresolved ARP"), 2072 NULL, 1, &arp_nd_domain.nd_maxqueuelen, 0, 2073 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2074 2075 sysctl_createv(clog, 0, NULL, NULL, 2076 CTLFLAG_PERMANENT, 2077 CTLTYPE_STRUCT, "stats", 2078 SYSCTL_DESCR("ARP statistics"), 2079 sysctl_net_inet_arp_stats, 0, NULL, 0, 2080 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2081 2082 sysctl_createv(clog, 0, NULL, NULL, 2083 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2084 CTLTYPE_INT, "log_movements", 2085 SYSCTL_DESCR("log ARP replies from MACs different than" 2086 " the one in the cache"), 2087 NULL, 0, &log_movements, 0, 2088 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2089 2090 sysctl_createv(clog, 0, NULL, NULL, 2091 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2092 CTLTYPE_INT, "log_permanent_modify", 2093 SYSCTL_DESCR("log ARP replies from MACs different than" 2094 " the one in the permanent arp entry"), 2095 NULL, 0, &log_permanent_modify, 0, 2096 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2097 2098 sysctl_createv(clog, 0, NULL, NULL, 2099 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2100 CTLTYPE_INT, "log_wrong_iface", 2101 SYSCTL_DESCR("log ARP packets arriving on the wrong" 2102 " interface"), 2103 NULL, 0, &log_wrong_iface, 0, 2104 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2105 2106 sysctl_createv(clog, 0, NULL, NULL, 2107 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2108 CTLTYPE_INT, "debug", 2109 SYSCTL_DESCR("Enable ARP DAD debug output"), 2110 NULL, 0, &arp_debug, 0, 2111 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2112 } 2113 2114 #endif /* INET */ 2115
Indexes created Wed Jun 10 00:26:05 UTC 2026