if_arp.c revision 1.319
1 /* $NetBSD: if_arp.c,v 1.319 2026/03/26 04:35:17 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 1.319 2026/03/26 04:35:17 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_nud_enabled = arp_nud_enabled, 161 .nd_reachable = arp_llinfo_reachable, 162 .nd_retrans = arp_llinfo_retrans, 163 .nd_holdsrc = arp_llinfo_holdsrc, 164 .nd_output = arp_llinfo_output, 165 .nd_missed = arp_llinfo_missed, 166 .nd_free = arp_free, 167 }; 168 169 int ip_dad_count = PROBE_NUM; 170 #ifdef ARP_DEBUG 171 int arp_debug = 1; 172 #else 173 int arp_debug = 0; 174 #endif 175 176 static void arp_init(void); 177 static void arp_dad_init(void); 178 179 static void arprequest(struct ifnet *, 180 const struct in_addr *, const struct in_addr *, 181 const uint8_t *, const uint8_t *); 182 static void arpannounce1(struct ifaddr *); 183 static struct sockaddr *arp_setgate(struct rtentry *, struct sockaddr *, 184 const struct sockaddr *); 185 static struct llentry *arpcreate(struct ifnet *, 186 const struct in_addr *, const struct sockaddr *, int); 187 static void in_arpinput(struct mbuf *); 188 static void in_revarpinput(struct mbuf *); 189 static void revarprequest(struct ifnet *); 190 191 static void arp_drainstub(void); 192 193 struct dadq; 194 static void arp_dad_timer(struct dadq *); 195 static void arp_dad_start(struct ifaddr *); 196 static void arp_dad_stop(struct ifaddr *); 197 static void arp_dad_duplicated(struct ifaddr *, const struct sockaddr_dl *); 198 199 #define ARP_MAXQLEN 50 200 pktqueue_t * arp_pktq __read_mostly; 201 202 static int useloopback = 1; /* use loopback interface for local traffic */ 203 204 static percpu_t *arpstat_percpu; 205 206 #define ARP_STAT_GETREF() _NET_STAT_GETREF(arpstat_percpu) 207 #define ARP_STAT_PUTREF() _NET_STAT_PUTREF(arpstat_percpu) 208 209 #define ARP_STATINC(x) _NET_STATINC(arpstat_percpu, x) 210 #define ARP_STATADD(x, v) _NET_STATADD(arpstat_percpu, x, v) 211 212 /* revarp state */ 213 static struct in_addr myip, srv_ip; 214 static int myip_initialized = 0; 215 static int revarp_in_progress = 0; 216 static struct ifnet *myip_ifp = NULL; 217 218 static int arp_drainwanted; 219 220 static int log_movements = 0; 221 static int log_permanent_modify = 1; 222 static int log_wrong_iface = 1; 223 224 DOMAIN_DEFINE(arpdomain); /* forward declare and add to link set */ 225 226 static void 227 arp_fasttimo(void) 228 { 229 if (arp_drainwanted) { 230 arp_drain(); 231 arp_drainwanted = 0; 232 } 233 } 234 235 static const struct protosw arpsw[] = { 236 { 237 .pr_type = 0, 238 .pr_domain = &arpdomain, 239 .pr_protocol = 0, 240 .pr_flags = 0, 241 .pr_input = 0, 242 .pr_ctlinput = 0, 243 .pr_ctloutput = 0, 244 .pr_usrreqs = 0, 245 .pr_init = arp_init, 246 .pr_fasttimo = arp_fasttimo, 247 .pr_slowtimo = 0, 248 .pr_drain = arp_drainstub, 249 } 250 }; 251 252 struct domain arpdomain = { 253 .dom_family = PF_ARP, 254 .dom_name = "arp", 255 .dom_protosw = arpsw, 256 .dom_protoswNPROTOSW = &arpsw[__arraycount(arpsw)], 257 #ifdef MBUFTRACE 258 .dom_mowner = MOWNER_INIT("internet", "arp"), 259 #endif 260 }; 261 262 static void sysctl_net_inet_arp_setup(struct sysctllog **); 263 264 void 265 arp_init(void) 266 { 267 268 arp_pktq = pktq_create(ARP_MAXQLEN, arpintr, NULL); 269 KASSERT(arp_pktq != NULL); 270 271 sysctl_net_inet_arp_setup(NULL); 272 arpstat_percpu = percpu_alloc(sizeof(uint64_t) * ARP_NSTATS); 273 274 #ifdef MBUFTRACE 275 MOWNER_ATTACH(&arpdomain.dom_mowner); 276 #endif 277 278 nd_attach_domain(&arp_nd_domain); 279 arp_dad_init(); 280 } 281 282 static void 283 arp_drainstub(void) 284 { 285 arp_drainwanted = 1; 286 } 287 288 /* 289 * ARP protocol drain routine. Called when memory is in short supply. 290 * Called at splvm(); don't acquire softnet_lock as can be called from 291 * hardware interrupt handlers. 292 */ 293 void 294 arp_drain(void) 295 { 296 297 lltable_drain(AF_INET); 298 } 299 300 /* 301 * We set the gateway for RTF_CLONING routes to a "prototype" 302 * link-layer sockaddr whose interface type (if_type) and interface 303 * index (if_index) fields are prepared. 304 */ 305 static struct sockaddr * 306 arp_setgate(struct rtentry *rt, struct sockaddr *gate, 307 const struct sockaddr *netmask) 308 { 309 const struct ifnet *ifp = rt->rt_ifp; 310 uint8_t namelen = strlen(ifp->if_xname); 311 uint8_t addrlen = ifp->if_addrlen; 312 313 /* 314 * XXX: If this is a manually added route to interface 315 * such as older version of routed or gated might provide, 316 * restore cloning bit. 317 */ 318 if ((rt->rt_flags & RTF_HOST) == 0 && netmask != NULL && 319 satocsin(netmask)->sin_addr.s_addr != 0xffffffff) 320 rt->rt_flags |= RTF_CONNECTED; 321 322 if ((rt->rt_flags & (RTF_CONNECTED | RTF_LOCAL))) { 323 union { 324 struct sockaddr sa; 325 struct sockaddr_storage ss; 326 struct sockaddr_dl sdl; 327 } u; 328 /* 329 * Case 1: This route should come from a route to iface. 330 */ 331 sockaddr_dl_init(&u.sdl, sizeof(u.ss), 332 ifp->if_index, ifp->if_type, NULL, namelen, NULL, addrlen); 333 rt_setgate(rt, &u.sa); 334 gate = rt->rt_gateway; 335 } 336 return gate; 337 } 338 339 /* 340 * Parallel to llc_rtrequest. 341 */ 342 void 343 arp_rtrequest(int req, struct rtentry *rt, const struct rt_addrinfo *info) 344 { 345 struct sockaddr *gate = rt->rt_gateway; 346 struct in_ifaddr *ia; 347 struct ifaddr *ifa; 348 struct ifnet *ifp = rt->rt_ifp; 349 int bound; 350 int s; 351 352 if (req == RTM_LLINFO_UPD) { 353 if ((ifa = info->rti_ifa) != NULL) 354 arpannounce1(ifa); 355 return; 356 } 357 358 if ((rt->rt_flags & RTF_GATEWAY) != 0) { 359 if (req != RTM_ADD) 360 return; 361 362 /* 363 * linklayers with particular link MTU limitation. 364 */ 365 switch(ifp->if_type) { 366 #if NARCNET > 0 367 case IFT_ARCNET: 368 { 369 int arcipifmtu; 370 371 if (ifp->if_flags & IFF_LINK0) 372 arcipifmtu = arc_ipmtu; 373 else 374 arcipifmtu = ARCMTU; 375 if (ifp->if_mtu > arcipifmtu) 376 rt->rt_rmx.rmx_mtu = arcipifmtu; 377 break; 378 } 379 #endif 380 } 381 return; 382 } 383 384 switch (req) { 385 case RTM_SETGATE: 386 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 387 break; 388 case RTM_ADD: 389 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 390 if (gate == NULL) { 391 log(LOG_ERR, "%s: arp_setgate failed\n", __func__); 392 break; 393 } 394 if ((rt->rt_flags & RTF_CONNECTED) || 395 (rt->rt_flags & RTF_LOCAL)) { 396 /* 397 * linklayers with particular link MTU limitation. 398 */ 399 switch (ifp->if_type) { 400 #if NARCNET > 0 401 case IFT_ARCNET: 402 { 403 int arcipifmtu; 404 if (ifp->if_flags & IFF_LINK0) 405 arcipifmtu = arc_ipmtu; 406 else 407 arcipifmtu = ARCMTU; 408 409 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 410 (rt->rt_rmx.rmx_mtu > arcipifmtu || 411 (rt->rt_rmx.rmx_mtu == 0 && 412 ifp->if_mtu > arcipifmtu))) 413 rt->rt_rmx.rmx_mtu = arcipifmtu; 414 break; 415 } 416 #endif 417 } 418 if (rt->rt_flags & RTF_CONNECTED) 419 break; 420 } 421 422 bound = curlwp_bind(); 423 /* Announce a new entry if requested. */ 424 if (rt->rt_flags & RTF_ANNOUNCE) { 425 struct psref psref; 426 ia = in_get_ia_on_iface_psref( 427 satocsin(rt_getkey(rt))->sin_addr, ifp, &psref); 428 if (ia != NULL) { 429 arpannounce(ifp, &ia->ia_ifa, 430 CLLADDR(satocsdl(gate))); 431 ia4_release(ia, &psref); 432 } 433 } 434 435 if (gate->sa_family != AF_LINK || 436 gate->sa_len < sockaddr_dl_measure(0, ifp->if_addrlen)) { 437 log(LOG_DEBUG, "%s: bad gateway value\n", __func__); 438 goto out; 439 } 440 441 satosdl(gate)->sdl_type = ifp->if_type; 442 satosdl(gate)->sdl_index = ifp->if_index; 443 444 /* 445 * If the route is for a broadcast address mark it as such. 446 * This way we can avoid an expensive call to in_broadcast() 447 * in ip_output() most of the time (because the route passed 448 * to ip_output() is almost always a host route). 449 */ 450 if (rt->rt_flags & RTF_HOST && 451 !(rt->rt_flags & RTF_BROADCAST) && 452 in_broadcast(satocsin(rt_getkey(rt))->sin_addr, rt->rt_ifp)) 453 rt->rt_flags |= RTF_BROADCAST; 454 /* There is little point in resolving the broadcast address */ 455 if (rt->rt_flags & RTF_BROADCAST) 456 goto out; 457 458 /* 459 * When called from rt_ifa_addlocal, we cannot depend on that 460 * the address (rt_getkey(rt)) exits in the address list of the 461 * interface. So check RTF_LOCAL instead. 462 */ 463 if (rt->rt_flags & RTF_LOCAL) { 464 if (useloopback) { 465 rt->rt_ifp = lo0ifp; 466 rt->rt_rmx.rmx_mtu = 0; 467 } 468 goto out; 469 } 470 471 s = pserialize_read_enter(); 472 ia = in_get_ia_on_iface(satocsin(rt_getkey(rt))->sin_addr, ifp); 473 if (ia == NULL) { 474 pserialize_read_exit(s); 475 goto out; 476 } 477 478 if (useloopback) { 479 rt->rt_ifp = lo0ifp; 480 rt->rt_rmx.rmx_mtu = 0; 481 } 482 rt->rt_flags |= RTF_LOCAL; 483 484 if (ISSET(info->rti_flags, RTF_DONTCHANGEIFA)) { 485 pserialize_read_exit(s); 486 goto out; 487 } 488 /* 489 * make sure to set rt->rt_ifa to the interface 490 * address we are using, otherwise we will have trouble 491 * with source address selection. 492 */ 493 ifa = &ia->ia_ifa; 494 if (ifa != rt->rt_ifa) 495 /* Assume it doesn't sleep */ 496 rt_replace_ifa(rt, ifa); 497 pserialize_read_exit(s); 498 out: 499 curlwp_bindx(bound); 500 break; 501 } 502 } 503 504 /* 505 * Broadcast an ARP request. Caller specifies: 506 * - arp header source ip address 507 * - arp header target ip address 508 * - arp header source ethernet address 509 */ 510 static void 511 arprequest(struct ifnet *ifp, 512 const struct in_addr *sip, const struct in_addr *tip, 513 const uint8_t *saddr, const uint8_t *taddr) 514 { 515 struct mbuf *m; 516 struct arphdr *ah; 517 struct sockaddr sa; 518 net_stat_ref_t arps; 519 520 KASSERT(sip != NULL); 521 KASSERT(tip != NULL); 522 KASSERT(saddr != NULL); 523 524 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 525 return; 526 MCLAIM(m, &arpdomain.dom_mowner); 527 switch (ifp->if_type) { 528 case IFT_IEEE1394: 529 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 530 ifp->if_addrlen; 531 break; 532 default: 533 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 534 2 * ifp->if_addrlen; 535 break; 536 } 537 m->m_pkthdr.len = m->m_len; 538 m_align(m, m->m_len); 539 ah = mtod(m, struct arphdr *); 540 memset(ah, 0, m->m_len); 541 switch (ifp->if_type) { 542 case IFT_IEEE1394: /* RFC2734 */ 543 /* fill it now for ar_tpa computation */ 544 ah->ar_hrd = htons(ARPHRD_IEEE1394); 545 break; 546 default: 547 /* ifp->if_output will fill ar_hrd */ 548 break; 549 } 550 ah->ar_pro = htons(ETHERTYPE_IP); 551 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 552 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 553 ah->ar_op = htons(ARPOP_REQUEST); 554 memcpy(ar_sha(ah), saddr, ah->ar_hln); 555 if (taddr == NULL) 556 m->m_flags |= M_BCAST; 557 else 558 memcpy(ar_tha(ah), taddr, ah->ar_hln); 559 memcpy(ar_spa(ah), sip, ah->ar_pln); 560 memcpy(ar_tpa(ah), tip, ah->ar_pln); 561 sa.sa_family = AF_ARP; 562 sa.sa_len = 2; 563 arps = ARP_STAT_GETREF(); 564 _NET_STATINC_REF(arps, ARP_STAT_SNDTOTAL); 565 _NET_STATINC_REF(arps, ARP_STAT_SENDREQUEST); 566 ARP_STAT_PUTREF(); 567 if_output_lock(ifp, ifp, m, &sa, NULL); 568 } 569 570 void 571 arpannounce(struct ifnet *ifp, struct ifaddr *ifa, const uint8_t *enaddr) 572 { 573 struct in_ifaddr *ia = ifatoia(ifa); 574 struct in_addr *ip = &IA_SIN(ifa)->sin_addr; 575 576 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) { 577 ARPLOG(LOG_DEBUG, "%s not ready\n", ARPLOGADDR(ip)); 578 return; 579 } 580 arprequest(ifp, ip, ip, enaddr, NULL); 581 } 582 583 static void 584 arpannounce1(struct ifaddr *ifa) 585 { 586 587 arpannounce(ifa->ifa_ifp, ifa, CLLADDR(ifa->ifa_ifp->if_sadl)); 588 } 589 590 /* 591 * Resolve an IP address into an ethernet address. If success, desten is 592 * filled in. If there is no entry in arptab, set one up and broadcast a 593 * request for the IP address. Hold onto this mbuf and resend it once the 594 * address is finally resolved. 595 * 596 * A return value of 0 indicates that desten has been filled in and the packet 597 * should be sent normally; a return value of EWOULDBLOCK indicates that the 598 * packet has been held pending resolution. Any other value indicates an 599 * error. 600 */ 601 int 602 arpresolve(struct ifnet *ifp, const struct rtentry *rt, struct mbuf *m, 603 const struct sockaddr *dst, void *desten, size_t destlen) 604 { 605 struct llentry *la; 606 const char *create_lookup; 607 int error; 608 609 #if NCARP > 0 610 if (rt != NULL && rt->rt_ifp->if_type == IFT_CARP) 611 ifp = rt->rt_ifp; 612 #endif 613 614 KASSERT(m != NULL); 615 616 la = arplookup(ifp, NULL, dst, 0); 617 if (la == NULL) 618 goto notfound; 619 620 if (la->la_flags & LLE_VALID && la->ln_state == ND_LLINFO_REACHABLE) { 621 KASSERT(destlen >= ifp->if_addrlen); 622 memcpy(desten, &la->ll_addr, ifp->if_addrlen); 623 LLE_RUNLOCK(la); 624 return 0; 625 } 626 627 notfound: 628 if (ifp->if_flags & IFF_NOARP) { 629 if (la != NULL) 630 LLE_RUNLOCK(la); 631 error = ENOTSUP; 632 goto bad; 633 } 634 635 if (la == NULL) { 636 struct rtentry *_rt; 637 638 create_lookup = "create"; 639 _rt = rtalloc1(dst, 0); 640 IF_AFDATA_WLOCK(ifp); 641 la = lla_create(LLTABLE(ifp), LLE_EXCLUSIVE, dst, _rt); 642 IF_AFDATA_WUNLOCK(ifp); 643 if (_rt != NULL) 644 rt_unref(_rt); 645 if (la == NULL) 646 ARP_STATINC(ARP_STAT_ALLOCFAIL); 647 else 648 la->ln_state = ND_LLINFO_NOSTATE; 649 } else if (LLE_TRY_UPGRADE(la) == 0) { 650 create_lookup = "lookup"; 651 LLE_RUNLOCK(la); 652 IF_AFDATA_RLOCK(ifp); 653 la = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst); 654 IF_AFDATA_RUNLOCK(ifp); 655 } 656 657 error = EINVAL; 658 if (la == NULL) { 659 log(LOG_DEBUG, 660 "%s: failed to %s llentry for %s on %s\n", 661 __func__, create_lookup, inet_ntoa(satocsin(dst)->sin_addr), 662 ifp->if_xname); 663 goto bad; 664 } 665 666 error = nd_resolve(la, rt, m, desten, destlen); 667 return error; 668 669 bad: 670 m_freem(m); 671 return error; 672 } 673 674 /* 675 * Common length and type checks are done here, 676 * then the protocol-specific routine is called. 677 */ 678 void 679 arpintr(void *arg __unused) 680 { 681 struct mbuf *m; 682 struct arphdr *ar; 683 int s; 684 int arplen; 685 struct ifnet *rcvif; 686 bool badhrd; 687 688 SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE(); 689 while ((m = pktq_dequeue(arp_pktq)) != NULL) { 690 if ((m->m_flags & M_PKTHDR) == 0) 691 panic("arpintr"); 692 693 MCLAIM(m, &arpdomain.dom_mowner); 694 ARP_STATINC(ARP_STAT_RCVTOTAL); 695 696 if (__predict_false(m->m_len < sizeof(*ar))) { 697 if ((m = m_pullup(m, sizeof(*ar))) == NULL) 698 goto badlen; 699 } 700 ar = mtod(m, struct arphdr *); 701 KASSERT(ACCESSIBLE_POINTER(ar, struct arphdr)); 702 703 rcvif = m_get_rcvif(m, &s); 704 if (__predict_false(rcvif == NULL)) { 705 ARP_STATINC(ARP_STAT_RCVNOINT); 706 goto free; 707 } 708 709 /* 710 * We don't want non-IEEE1394 ARP packets on IEEE1394 711 * interfaces, and vice versa. Our life depends on that. 712 */ 713 if (ntohs(ar->ar_hrd) == ARPHRD_IEEE1394) 714 badhrd = rcvif->if_type != IFT_IEEE1394; 715 else 716 badhrd = rcvif->if_type == IFT_IEEE1394; 717 718 m_put_rcvif(rcvif, &s); 719 720 if (badhrd) { 721 ARP_STATINC(ARP_STAT_RCVBADPROTO); 722 goto free; 723 } 724 725 arplen = sizeof(*ar) + 2 * ar->ar_hln + 2 * ar->ar_pln; 726 if (__predict_false(m->m_len < arplen)) { 727 if ((m = m_pullup(m, arplen)) == NULL) 728 goto badlen; 729 ar = mtod(m, struct arphdr *); 730 KASSERT(ACCESSIBLE_POINTER(ar, struct arphdr)); 731 } 732 733 switch (ntohs(ar->ar_pro)) { 734 case ETHERTYPE_IP: 735 case ETHERTYPE_IPTRAILERS: 736 in_arpinput(m); 737 continue; 738 default: 739 ARP_STATINC(ARP_STAT_RCVBADPROTO); 740 goto free; 741 } 742 743 badlen: 744 ARP_STATINC(ARP_STAT_RCVBADLEN); 745 free: 746 m_freem(m); 747 } 748 SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 749 return; /* XXX gcc */ 750 } 751 752 /* 753 * ARP for Internet protocols on 10 Mb/s Ethernet. Algorithm is that given in 754 * RFC 826. In addition, a sanity check is performed on the sender protocol 755 * address, to catch impersonators. 756 * 757 * We no longer handle negotiations for use of trailer protocol: formerly, ARP 758 * replied for protocol type ETHERTYPE_TRAIL sent along with IP replies if we 759 * wanted trailers sent to us, and also sent them in response to IP replies. 760 * This allowed either end to announce the desire to receive trailer packets. 761 * 762 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, but 763 * formerly didn't normally send requests. 764 */ 765 static void 766 in_arpinput(struct mbuf *m) 767 { 768 struct arphdr *ah; 769 struct ifnet *ifp, *rcvif = NULL; 770 struct llentry *la = NULL; 771 struct in_ifaddr *ia = NULL; 772 #if NBRIDGE > 0 773 struct in_ifaddr *bridge_ia = NULL; 774 #endif 775 #if NCARP > 0 776 uint32_t count = 0, index = 0; 777 #endif 778 struct sockaddr sa; 779 struct in_addr isaddr, itaddr, myaddr; 780 int op, rt_cmd, new_state = 0; 781 void *tha; 782 net_stat_ref_t arps; 783 struct psref psref, psref_ia; 784 int s; 785 char ipbuf[INET_ADDRSTRLEN]; 786 bool find_source, do_dad; 787 788 if (__predict_false(m_makewritable(&m, 0, m->m_pkthdr.len, M_DONTWAIT))) 789 goto out; 790 ah = mtod(m, struct arphdr *); 791 op = ntohs(ah->ar_op); 792 793 if (ah->ar_pln != sizeof(struct in_addr)) 794 goto out; 795 796 /* RFC5227 2.4 says any of the host's own interface addresses 797 * are not conflicting ARP packets. */ 798 ifp = if_get_bylla(ar_sha(ah), ah->ar_hln, &psref); 799 if (ifp) { 800 /* it's from me, ignore it. */ 801 if_put(ifp, &psref); 802 ARP_STATINC(ARP_STAT_RCVLOCALSHA); 803 goto out; 804 } 805 806 rcvif = ifp = m_get_rcvif_psref(m, &psref); 807 if (__predict_false(rcvif == NULL)) 808 goto out; 809 if (rcvif->if_flags & IFF_NOARP) 810 goto out; 811 812 memcpy(&isaddr, ar_spa(ah), sizeof(isaddr)); 813 memcpy(&itaddr, ar_tpa(ah), sizeof(itaddr)); 814 815 if (m->m_flags & (M_BCAST|M_MCAST)) 816 ARP_STATINC(ARP_STAT_RCVMCAST); 817 818 /* 819 * Search for a matching interface address 820 * or any address on the interface to use 821 * as a dummy address in the rest of this function. 822 * 823 * First try and find the source address for early 824 * duplicate address detection. 825 */ 826 if (in_nullhost(isaddr)) { 827 if (in_nullhost(itaddr)) /* very bogus ARP */ 828 goto out; 829 find_source = false; 830 myaddr = itaddr; 831 } else { 832 find_source = true; 833 myaddr = isaddr; 834 } 835 s = pserialize_read_enter(); 836 again: 837 IN_ADDRHASH_READER_FOREACH(ia, myaddr.s_addr) { 838 if (!in_hosteq(ia->ia_addr.sin_addr, myaddr)) 839 continue; 840 #if NCARP > 0 841 if (ia->ia_ifp->if_type == IFT_CARP && 842 ((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) == 843 (IFF_UP|IFF_RUNNING))) { 844 index++; 845 /* XXX: ar_hln? */ 846 if (ia->ia_ifp == rcvif && (ah->ar_hln >= 6) && 847 carp_iamatch(ia, ar_sha(ah), 848 &count, index)) { 849 break; 850 } 851 } else 852 #endif 853 if (ia->ia_ifp == rcvif) 854 break; 855 #if NBRIDGE > 0 856 /* 857 * If the interface we received the packet on 858 * is part of a bridge, check to see if we need 859 * to "bridge" the packet to ourselves at this 860 * layer. Note we still prefer a perfect match, 861 * but allow this weaker match if necessary. 862 */ 863 if (rcvif->if_bridge != NULL && 864 rcvif->if_bridge == ia->ia_ifp->if_bridge) 865 bridge_ia = ia; 866 #endif 867 } 868 869 #if NBRIDGE > 0 870 if (ia == NULL && bridge_ia != NULL) { 871 ia = bridge_ia; 872 m_put_rcvif_psref(rcvif, &psref); 873 rcvif = NULL; 874 /* FIXME */ 875 ifp = bridge_ia->ia_ifp; 876 } 877 #endif 878 879 /* If we failed to find the source address then find 880 * the target address. */ 881 if (ia == NULL && find_source && !in_nullhost(itaddr)) { 882 find_source = false; 883 myaddr = itaddr; 884 goto again; 885 } 886 887 if (ia != NULL) 888 ia4_acquire(ia, &psref_ia); 889 pserialize_read_exit(s); 890 891 if (ah->ar_hln != ifp->if_addrlen) { 892 ARP_STATINC(ARP_STAT_RCVBADLEN); 893 log(LOG_WARNING, 894 "arp from %s: addr len: new %d, i/f %d (ignored)\n", 895 IN_PRINT(ipbuf, &isaddr), ah->ar_hln, ifp->if_addrlen); 896 goto out; 897 } 898 899 /* Only do DaD if we have a matching address. */ 900 do_dad = (ia != NULL); 901 902 if (ia == NULL) { 903 ia = in_get_ia_on_iface_psref(isaddr, rcvif, &psref_ia); 904 if (ia == NULL) { 905 ia = in_get_ia_from_ifp_psref(ifp, &psref_ia); 906 if (ia == NULL) { 907 ARP_STATINC(ARP_STAT_RCVNOINT); 908 goto out; 909 } 910 } 911 } 912 913 myaddr = ia->ia_addr.sin_addr; 914 915 /* XXX checks for bridge case? */ 916 if (!memcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 917 ARP_STATINC(ARP_STAT_RCVBCASTSHA); 918 log(LOG_ERR, 919 "%s: arp: link address is broadcast for IP address %s!\n", 920 ifp->if_xname, IN_PRINT(ipbuf, &isaddr)); 921 goto out; 922 } 923 924 /* 925 * If the source IP address is zero, this is an RFC 5227 ARP probe 926 */ 927 if (in_nullhost(isaddr)) 928 ARP_STATINC(ARP_STAT_RCVZEROSPA); 929 else if (in_hosteq(isaddr, myaddr)) { 930 ARP_STATINC(ARP_STAT_RCVLOCALSPA); 931 /* This is the original behavior prior to supporting IPv4 DAD */ 932 if (!ip_dad_enabled()) { 933 char llabuf[LLA_ADDRSTRLEN]; 934 log(LOG_ERR, 935 "duplicate IP address %s sent from link address %s\n", 936 IN_PRINT(ipbuf, &isaddr), 937 lla_snprintf(llabuf, sizeof(llabuf), ar_sha(ah), 938 ah->ar_hln)); 939 itaddr = myaddr; 940 goto reply; 941 } 942 } 943 944 if (in_nullhost(itaddr)) 945 ARP_STATINC(ARP_STAT_RCVZEROTPA); 946 947 /* 948 * DAD check, RFC 5227. 949 * ARP sender hardware address must match the interface 950 * address of the interface sending the packet. 951 * Collision on sender address is always a duplicate. 952 * Collision on target address is only a duplicate 953 * IF the sender address is the null host (ie a DAD probe) 954 * AND the message was broadcast 955 * AND our address is either tentative or duplicated 956 * If it was unicast then it's a valid Unicast Poll from RFC 1122. 957 */ 958 if (ip_dad_enabled() && do_dad && 959 (in_hosteq(isaddr, myaddr) || 960 (in_nullhost(isaddr) && in_hosteq(itaddr, myaddr) && 961 m->m_flags & M_BCAST && 962 ia->ia4_flags & (IN_IFF_TENTATIVE | IN_IFF_DUPLICATED)))) 963 { 964 struct m_tag *mtag; 965 966 mtag = m_tag_find(m, PACKET_TAG_ETHERNET_SRC); 967 if (mtag == NULL || (ah->ar_hln == ETHER_ADDR_LEN && 968 memcmp(mtag + 1, ar_sha(ah), ah->ar_hln) == 0)) { 969 struct sockaddr_dl sdl, *sdlp; 970 971 sdlp = sockaddr_dl_init(&sdl, sizeof(sdl), 972 ifp->if_index, ifp->if_type, 973 NULL, 0, ar_sha(ah), ah->ar_hln); 974 arp_dad_duplicated((struct ifaddr *)ia, sdlp); 975 goto out; 976 } 977 } 978 979 /* 980 * If the target IP address is zero, ignore the packet. 981 * This prevents the code below from trying to answer 982 * when we are using IP address zero (booting). 983 */ 984 if (in_nullhost(itaddr)) 985 goto out; 986 987 if (in_nullhost(isaddr)) 988 goto reply; 989 990 if (in_hosteq(itaddr, myaddr)) 991 la = arpcreate(ifp, &isaddr, NULL, 1); 992 else 993 la = arplookup(ifp, &isaddr, NULL, 1); 994 if (la == NULL) 995 goto reply; 996 997 if ((la->la_flags & LLE_VALID) && 998 memcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) 999 { 1000 char llabuf[LLA_ADDRSTRLEN], *llastr; 1001 1002 llastr = lla_snprintf(llabuf, sizeof(llabuf), 1003 ar_sha(ah), ah->ar_hln); 1004 1005 if (la->la_flags & LLE_STATIC) { 1006 ARP_STATINC(ARP_STAT_RCVOVERPERM); 1007 if (!log_permanent_modify) 1008 goto out; 1009 log(LOG_INFO, 1010 "%s tried to overwrite permanent arp info" 1011 " for %s\n", llastr, IN_PRINT(ipbuf, &isaddr)); 1012 goto out; 1013 } else if (la->lle_tbl->llt_ifp != ifp) { 1014 /* XXX should not happen? */ 1015 ARP_STATINC(ARP_STAT_RCVOVERINT); 1016 if (!log_wrong_iface) 1017 goto out; 1018 log(LOG_INFO, 1019 "%s on %s tried to overwrite " 1020 "arp info for %s on %s\n", 1021 llastr, 1022 ifp->if_xname, IN_PRINT(ipbuf, &isaddr), 1023 la->lle_tbl->llt_ifp->if_xname); 1024 goto out; 1025 } else { 1026 ARP_STATINC(ARP_STAT_RCVOVER); 1027 if (log_movements) 1028 log(LOG_INFO, "arp info overwritten " 1029 "for %s by %s\n", 1030 IN_PRINT(ipbuf, &isaddr), llastr); 1031 } 1032 rt_cmd = RTM_CHANGE; 1033 new_state = ND_LLINFO_STALE; 1034 } else { 1035 if (op == ARPOP_REPLY && in_hosteq(itaddr, myaddr)) { 1036 /* This was a solicited ARP reply. */ 1037 la->ln_byhint = 0; 1038 new_state = ND_LLINFO_REACHABLE; 1039 } else if (op == ARPOP_REQUEST && 1040 (la->ln_state == ND_LLINFO_NOSTATE || 1041 la->ln_state == ND_LLINFO_INCOMPLETE)) { 1042 /* 1043 * If an ARP request comes but there is no entry 1044 * and a new one has been created or an entry exists 1045 * but incomplete, make it stale to allow to send 1046 * packets to the requester without an ARP resolution. 1047 */ 1048 la->ln_byhint = 0; 1049 new_state = ND_LLINFO_STALE; 1050 } 1051 rt_cmd = la->la_flags & LLE_VALID ? 0 : RTM_ADD; 1052 } 1053 1054 KASSERT(ifp->if_sadl->sdl_alen == ifp->if_addrlen); 1055 1056 KASSERT(sizeof(la->ll_addr) >= ifp->if_addrlen); 1057 memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen); 1058 la->la_flags |= LLE_VALID; 1059 la->la_flags &= ~LLE_UNRESOLVED; 1060 la->ln_asked = 0; 1061 if (new_state != 0) { 1062 la->ln_state = new_state; 1063 1064 if (new_state != ND_LLINFO_REACHABLE || 1065 !(la->la_flags & LLE_STATIC)) 1066 { 1067 int timer = ND_TIMER_GC; 1068 1069 if (new_state == ND_LLINFO_REACHABLE) 1070 timer = ND_TIMER_REACHABLE; 1071 nd_set_timer(la, timer); 1072 } 1073 } 1074 1075 if (rt_cmd != 0) { 1076 struct sockaddr_in sin; 1077 1078 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 1079 rt_clonedmsg(rt_cmd, NULL, sintosa(&sin), ar_sha(ah), ifp); 1080 } 1081 1082 if (la->la_hold != NULL) { 1083 int n = la->la_numheld; 1084 struct mbuf *m_hold, *m_hold_next; 1085 struct sockaddr_in sin; 1086 1087 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 1088 1089 m_hold = la->la_hold; 1090 la->la_hold = NULL; 1091 la->la_numheld = 0; 1092 /* 1093 * We have to unlock here because if_output would call 1094 * arpresolve 1095 */ 1096 LLE_WUNLOCK(la); 1097 ARP_STATADD(ARP_STAT_DFRSENT, n); 1098 ARP_STATADD(ARP_STAT_DFRTOTAL, n); 1099 for (; m_hold != NULL; m_hold = m_hold_next) { 1100 m_hold_next = m_hold->m_nextpkt; 1101 m_hold->m_nextpkt = NULL; 1102 if_output_lock(ifp, ifp, m_hold, sintosa(&sin), NULL); 1103 } 1104 } else 1105 LLE_WUNLOCK(la); 1106 la = NULL; 1107 1108 reply: 1109 if (la != NULL) { 1110 LLE_WUNLOCK(la); 1111 la = NULL; 1112 } 1113 if (op != ARPOP_REQUEST) { 1114 if (op == ARPOP_REPLY) 1115 ARP_STATINC(ARP_STAT_RCVREPLY); 1116 goto out; 1117 } 1118 ARP_STATINC(ARP_STAT_RCVREQUEST); 1119 if (in_hosteq(itaddr, myaddr)) { 1120 /* If our address is unusable, don't reply */ 1121 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) 1122 goto out; 1123 /* I am the target */ 1124 tha = ar_tha(ah); 1125 if (tha) 1126 memcpy(tha, ar_sha(ah), ah->ar_hln); 1127 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1128 } else { 1129 /* Proxy ARP */ 1130 struct llentry *lle = NULL; 1131 struct sockaddr_in sin; 1132 1133 #if NCARP > 0 1134 if (ifp->if_type == IFT_CARP) { 1135 struct ifnet *_rcvif = m_get_rcvif(m, &s); 1136 int iftype = 0; 1137 if (__predict_true(_rcvif != NULL)) 1138 iftype = _rcvif->if_type; 1139 m_put_rcvif(_rcvif, &s); 1140 if (iftype != IFT_CARP) 1141 goto out; 1142 } 1143 #endif 1144 1145 tha = ar_tha(ah); 1146 1147 sockaddr_in_init(&sin, &itaddr, 0); 1148 1149 IF_AFDATA_RLOCK(ifp); 1150 lle = lla_lookup(LLTABLE(ifp), 0, (struct sockaddr *)&sin); 1151 IF_AFDATA_RUNLOCK(ifp); 1152 1153 if ((lle != NULL) && (lle->la_flags & LLE_PUB)) { 1154 if (tha) 1155 memcpy(tha, ar_sha(ah), ah->ar_hln); 1156 memcpy(ar_sha(ah), &lle->ll_addr, ah->ar_hln); 1157 LLE_RUNLOCK(lle); 1158 } else { 1159 if (lle != NULL) 1160 LLE_RUNLOCK(lle); 1161 goto out; 1162 } 1163 } 1164 ia4_release(ia, &psref_ia); 1165 1166 /* 1167 * XXX XXX: Here we're recycling the mbuf. But the mbuf could have 1168 * other mbufs in its chain, and just overwriting m->m_pkthdr.len 1169 * would be wrong in this case (the length becomes smaller than the 1170 * real chain size). 1171 * 1172 * This can theoretically cause bugs in the lower layers (drivers, 1173 * and L2encap), in some corner cases. 1174 */ 1175 memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); 1176 memcpy(ar_spa(ah), &itaddr, ah->ar_pln); 1177 ah->ar_op = htons(ARPOP_REPLY); 1178 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 1179 switch (ifp->if_type) { 1180 case IFT_IEEE1394: 1181 /* ieee1394 arp reply is broadcast */ 1182 m->m_flags &= ~M_MCAST; 1183 m->m_flags |= M_BCAST; 1184 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + ah->ar_hln; 1185 break; 1186 default: 1187 m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */ 1188 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); 1189 break; 1190 } 1191 m->m_pkthdr.len = m->m_len; 1192 m->m_pkthdr.csum_flags = 0; /* Clear any in-bound checksum flags. */ 1193 sa.sa_family = AF_ARP; 1194 sa.sa_len = 2; 1195 arps = ARP_STAT_GETREF(); 1196 _NET_STATINC_REF(arps, ARP_STAT_SNDTOTAL); 1197 _NET_STATINC_REF(arps, ARP_STAT_SNDREPLY); 1198 ARP_STAT_PUTREF(); 1199 if_output_lock(ifp, ifp, m, &sa, NULL); 1200 if (rcvif != NULL) 1201 m_put_rcvif_psref(rcvif, &psref); 1202 return; 1203 1204 out: 1205 if (la != NULL) 1206 LLE_WUNLOCK(la); 1207 if (ia != NULL) 1208 ia4_release(ia, &psref_ia); 1209 if (rcvif != NULL) 1210 m_put_rcvif_psref(rcvif, &psref); 1211 m_freem(m); 1212 } 1213 1214 /* 1215 * Lookup or a new address in arptab. 1216 */ 1217 struct llentry * 1218 arplookup(struct ifnet *ifp, const struct in_addr *addr, 1219 const struct sockaddr *sa, int wlock) 1220 { 1221 struct sockaddr_in sin; 1222 struct llentry *la; 1223 int flags = wlock ? LLE_EXCLUSIVE : 0; 1224 1225 if (sa == NULL) { 1226 KASSERT(addr != NULL); 1227 sockaddr_in_init(&sin, addr, 0); 1228 sa = sintocsa(&sin); 1229 } 1230 1231 IF_AFDATA_RLOCK(ifp); 1232 la = lla_lookup(LLTABLE(ifp), flags, sa); 1233 IF_AFDATA_RUNLOCK(ifp); 1234 1235 return la; 1236 } 1237 1238 static struct llentry * 1239 arpcreate(struct ifnet *ifp, const struct in_addr *addr, 1240 const struct sockaddr *sa, int wlock) 1241 { 1242 struct sockaddr_in sin; 1243 struct llentry *la; 1244 int flags = wlock ? LLE_EXCLUSIVE : 0; 1245 1246 if (sa == NULL) { 1247 KASSERT(addr != NULL); 1248 sockaddr_in_init(&sin, addr, 0); 1249 sa = sintocsa(&sin); 1250 } 1251 1252 la = arplookup(ifp, addr, sa, wlock); 1253 1254 if (la == NULL) { 1255 struct rtentry *rt; 1256 1257 rt = rtalloc1(sa, 0); 1258 IF_AFDATA_WLOCK(ifp); 1259 la = lla_create(LLTABLE(ifp), flags, sa, rt); 1260 IF_AFDATA_WUNLOCK(ifp); 1261 if (rt != NULL) 1262 rt_unref(rt); 1263 1264 if (la != NULL) 1265 la->ln_state = ND_LLINFO_NOSTATE; 1266 } 1267 1268 return la; 1269 } 1270 1271 int 1272 arpioctl(u_long cmd, void *data) 1273 { 1274 1275 return EOPNOTSUPP; 1276 } 1277 1278 void 1279 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1280 { 1281 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1282 1283 ifa->ifa_rtrequest = arp_rtrequest; 1284 ifa->ifa_flags |= RTF_CONNECTED; 1285 1286 /* ARP will handle DAD for this address. */ 1287 if (in_nullhost(IA_SIN(ifa)->sin_addr)) { 1288 if (ia->ia_dad_stop != NULL) /* safety */ 1289 ia->ia_dad_stop(ifa); 1290 ia->ia_dad_start = NULL; 1291 ia->ia_dad_stop = NULL; 1292 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1293 } else { 1294 ia->ia_dad_start = arp_dad_start; 1295 ia->ia_dad_stop = arp_dad_stop; 1296 if (ia->ia4_flags & IN_IFF_TRYTENTATIVE && ip_dad_enabled()) 1297 ia->ia4_flags |= IN_IFF_TENTATIVE; 1298 else 1299 arpannounce1(ifa); 1300 } 1301 } 1302 1303 static bool 1304 arp_nud_enabled(__unused struct ifnet *ifp) 1305 { 1306 1307 return arp_perform_nud != 0; 1308 } 1309 1310 static unsigned int 1311 arp_llinfo_reachable(__unused struct ifnet *ifp) 1312 { 1313 1314 return arp_reachable; 1315 } 1316 1317 static unsigned int 1318 arp_llinfo_retrans(__unused struct ifnet *ifp) 1319 { 1320 1321 return arp_retrans; 1322 } 1323 1324 /* 1325 * Gets source address of the first packet in hold queue 1326 * and stores it in @src. 1327 * Returns pointer to @src (if hold queue is not empty) or NULL. 1328 */ 1329 static union l3addr * 1330 arp_llinfo_holdsrc(struct llentry *ln, union l3addr *src) 1331 { 1332 struct ip *ip; 1333 1334 if (ln == NULL || ln->ln_hold == NULL) 1335 return NULL; 1336 1337 /* 1338 * assuming every packet in ln_hold has the same IP header 1339 */ 1340 ip = mtod(ln->ln_hold, struct ip *); 1341 /* XXX pullup? */ 1342 if (sizeof(*ip) < ln->ln_hold->m_len) 1343 src->addr4 = ip->ip_src; 1344 else 1345 src = NULL; 1346 1347 return src; 1348 } 1349 1350 static void 1351 arp_llinfo_output(struct ifnet *ifp, __unused const union l3addr *daddr, 1352 const union l3addr *taddr, const uint8_t *tlladdr, 1353 const union l3addr *hsrc) 1354 { 1355 struct in_addr tip = taddr->addr4, sip = zeroin_addr; 1356 const uint8_t *slladdr = CLLADDR(ifp->if_sadl); 1357 1358 if (hsrc != NULL) { 1359 struct in_ifaddr *ia; 1360 struct psref psref; 1361 1362 ia = in_get_ia_on_iface_psref(hsrc->addr4, ifp, &psref); 1363 if (ia != NULL) { 1364 sip = hsrc->addr4; 1365 ia4_release(ia, &psref); 1366 } 1367 } 1368 1369 if (sip.s_addr == INADDR_ANY) { 1370 struct sockaddr_in dst; 1371 struct rtentry *rt; 1372 1373 sockaddr_in_init(&dst, &tip, 0); 1374 rt = rtalloc1(sintosa(&dst), 0); 1375 if (rt != NULL) { 1376 if (rt->rt_ifp == ifp && 1377 rt->rt_ifa != NULL && 1378 rt->rt_ifa->ifa_addr->sa_family == AF_INET) 1379 sip = satosin(rt->rt_ifa->ifa_addr)->sin_addr; 1380 rt_unref(rt); 1381 } 1382 if (sip.s_addr == INADDR_ANY) { 1383 char ipbuf[INET_ADDRSTRLEN]; 1384 1385 log(LOG_DEBUG, "%s: source can't be " 1386 "determined: dst=%s\n", __func__, 1387 IN_PRINT(ipbuf, &tip)); 1388 return; 1389 } 1390 } 1391 1392 arprequest(ifp, &sip, &tip, slladdr, tlladdr); 1393 } 1394 1395 1396 static void 1397 arp_llinfo_missed(struct ifnet *ifp, const union l3addr *taddr, 1398 __unused int16_t type, struct mbuf *m) 1399 { 1400 struct in_addr mdaddr = zeroin_addr; 1401 struct sockaddr_in dsin, tsin; 1402 struct sockaddr *sa; 1403 1404 if (m != NULL) { 1405 struct ip *ip = mtod(m, struct ip *); 1406 1407 if (sizeof(*ip) < m->m_len) 1408 mdaddr = ip->ip_src; 1409 1410 /* ip_input() will send ICMP_UNREACH_HOST, not us. */ 1411 m_freem(m); 1412 } 1413 1414 if (mdaddr.s_addr != INADDR_ANY) { 1415 sockaddr_in_init(&dsin, &mdaddr, 0); 1416 sa = sintosa(&dsin); 1417 } else 1418 sa = NULL; 1419 1420 sockaddr_in_init(&tsin, &taddr->addr4, 0); 1421 rt_clonedmsg(RTM_MISS, sa, sintosa(&tsin), NULL, ifp); 1422 } 1423 1424 static void 1425 arp_free(struct llentry *ln, int gc) 1426 { 1427 struct ifnet *ifp; 1428 1429 KASSERT(ln != NULL); 1430 LLE_WLOCK_ASSERT(ln); 1431 1432 ifp = ln->lle_tbl->llt_ifp; 1433 1434 if (ln->la_flags & LLE_VALID || gc) { 1435 struct sockaddr_in sin; 1436 const char *lladdr; 1437 1438 sockaddr_in_init(&sin, &ln->r_l3addr.addr4, 0); 1439 lladdr = ln->la_flags & LLE_VALID ? 1440 (const char *)&ln->ll_addr : NULL; 1441 rt_clonedmsg(RTM_DELETE, NULL, sintosa(&sin), lladdr, ifp); 1442 } 1443 1444 /* 1445 * Save to unlock. We still hold an extra reference and will not 1446 * free(9) in llentry_free() if someone else holds one as well. 1447 */ 1448 LLE_WUNLOCK(ln); 1449 IF_AFDATA_LOCK(ifp); 1450 LLE_WLOCK(ln); 1451 1452 lltable_free_entry(LLTABLE(ifp), ln); 1453 1454 IF_AFDATA_UNLOCK(ifp); 1455 } 1456 1457 /* 1458 * Upper-layer reachability hint for Neighbor Unreachability Detection. 1459 * 1460 * XXX cost-effective methods? 1461 */ 1462 void 1463 arp_nud_hint(struct rtentry *rt) 1464 { 1465 struct llentry *ln; 1466 struct ifnet *ifp; 1467 1468 if (rt == NULL) 1469 return; 1470 1471 ifp = rt->rt_ifp; 1472 ln = arplookup(ifp, NULL, rt_getkey(rt), 1); 1473 nd_nud_hint(ln); 1474 } 1475 1476 TAILQ_HEAD(dadq_head, dadq); 1477 struct dadq { 1478 TAILQ_ENTRY(dadq) dad_list; 1479 struct ifaddr *dad_ifa; 1480 int dad_count; /* max ARP to send */ 1481 int dad_arp_tcount; /* # of trials to send ARP */ 1482 int dad_arp_ocount; /* ARP sent so far */ 1483 int dad_arp_announce; /* max ARP announcements */ 1484 int dad_arp_acount; /* # of announcements */ 1485 struct callout dad_timer_ch; 1486 }; 1487 1488 static struct dadq_head dadq; 1489 static int dad_maxtry = 15; /* max # of *tries* to transmit DAD packet */ 1490 static kmutex_t arp_dad_lock; 1491 1492 static void 1493 arp_dad_init(void) 1494 { 1495 1496 TAILQ_INIT(&dadq); 1497 mutex_init(&arp_dad_lock, MUTEX_DEFAULT, IPL_NONE); 1498 } 1499 1500 static struct dadq * 1501 arp_dad_find(struct ifaddr *ifa) 1502 { 1503 struct dadq *dp; 1504 1505 KASSERT(mutex_owned(&arp_dad_lock)); 1506 1507 TAILQ_FOREACH(dp, &dadq, dad_list) { 1508 if (dp->dad_ifa == ifa) 1509 return dp; 1510 } 1511 return NULL; 1512 } 1513 1514 static void 1515 arp_dad_starttimer(struct dadq *dp, int ticks) 1516 { 1517 1518 callout_reset(&dp->dad_timer_ch, ticks, 1519 (void (*)(void *))arp_dad_timer, dp); 1520 } 1521 1522 static void 1523 arp_dad_stoptimer(struct dadq *dp) 1524 { 1525 1526 KASSERT(mutex_owned(&arp_dad_lock)); 1527 1528 TAILQ_REMOVE(&dadq, dp, dad_list); 1529 /* Tell the timer that dp is being destroyed. */ 1530 dp->dad_ifa = NULL; 1531 callout_halt(&dp->dad_timer_ch, &arp_dad_lock); 1532 } 1533 1534 static void 1535 arp_dad_destroytimer(struct dadq *dp) 1536 { 1537 1538 callout_destroy(&dp->dad_timer_ch); 1539 KASSERT(dp->dad_ifa == NULL); 1540 kmem_intr_free(dp, sizeof(*dp)); 1541 } 1542 1543 static void 1544 arp_dad_output(struct dadq *dp, struct ifaddr *ifa) 1545 { 1546 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1547 struct ifnet *ifp = ifa->ifa_ifp; 1548 struct in_addr sip; 1549 1550 dp->dad_arp_tcount++; 1551 if ((ifp->if_flags & IFF_UP) == 0) 1552 return; 1553 if ((ifp->if_flags & IFF_RUNNING) == 0) 1554 return; 1555 1556 dp->dad_arp_tcount = 0; 1557 dp->dad_arp_ocount++; 1558 1559 memset(&sip, 0, sizeof(sip)); 1560 arprequest(ifa->ifa_ifp, &sip, &ia->ia_addr.sin_addr, 1561 CLLADDR(ifa->ifa_ifp->if_sadl), NULL); 1562 } 1563 1564 /* 1565 * Start Duplicate Address Detection (DAD) for specified interface address. 1566 */ 1567 static void 1568 arp_dad_start(struct ifaddr *ifa) 1569 { 1570 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1571 struct dadq *dp; 1572 char ipbuf[INET_ADDRSTRLEN]; 1573 1574 /* 1575 * If we don't need DAD, don't do it. 1576 * - DAD is disabled 1577 */ 1578 if (!(ia->ia4_flags & IN_IFF_TENTATIVE)) { 1579 log(LOG_DEBUG, 1580 "%s: called with non-tentative address %s(%s)\n", __func__, 1581 IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1582 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1583 return; 1584 } 1585 if (!ip_dad_enabled()) { 1586 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1587 rt_addrmsg(RTM_NEWADDR, ifa); 1588 arpannounce1(ifa); 1589 return; 1590 } 1591 KASSERT(ifa->ifa_ifp != NULL); 1592 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) 1593 return; 1594 1595 dp = kmem_intr_alloc(sizeof(*dp), KM_NOSLEEP); 1596 1597 mutex_enter(&arp_dad_lock); 1598 if (arp_dad_find(ifa) != NULL) { 1599 mutex_exit(&arp_dad_lock); 1600 /* DAD already in progress */ 1601 if (dp != NULL) 1602 kmem_intr_free(dp, sizeof(*dp)); 1603 return; 1604 } 1605 1606 if (dp == NULL) { 1607 mutex_exit(&arp_dad_lock); 1608 log(LOG_ERR, "%s: memory allocation failed for %s(%s)\n", 1609 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1610 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1611 return; 1612 } 1613 1614 /* 1615 * Send ARP packet for DAD, ip_dad_count times. 1616 * Note that we must delay the first transmission. 1617 */ 1618 callout_init(&dp->dad_timer_ch, CALLOUT_MPSAFE); 1619 dp->dad_ifa = ifa; 1620 ifaref(ifa); /* just for safety */ 1621 dp->dad_count = ip_dad_count; 1622 dp->dad_arp_announce = 0; /* Will be set when starting to announce */ 1623 dp->dad_arp_acount = dp->dad_arp_ocount = dp->dad_arp_tcount = 0; 1624 TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list); 1625 1626 ARPLOG(LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1627 ARPLOGADDR(&ia->ia_addr.sin_addr)); 1628 1629 arp_dad_starttimer(dp, cprng_fast32() % (PROBE_WAIT * hz)); 1630 1631 mutex_exit(&arp_dad_lock); 1632 } 1633 1634 /* 1635 * terminate DAD unconditionally. used for address removals. 1636 */ 1637 static void 1638 arp_dad_stop(struct ifaddr *ifa) 1639 { 1640 struct dadq *dp; 1641 1642 mutex_enter(&arp_dad_lock); 1643 dp = arp_dad_find(ifa); 1644 if (dp == NULL) { 1645 mutex_exit(&arp_dad_lock); 1646 /* DAD wasn't started yet */ 1647 return; 1648 } 1649 1650 arp_dad_stoptimer(dp); 1651 1652 mutex_exit(&arp_dad_lock); 1653 1654 arp_dad_destroytimer(dp); 1655 ifafree(ifa); 1656 } 1657 1658 static void 1659 arp_dad_timer(struct dadq *dp) 1660 { 1661 struct ifaddr *ifa; 1662 struct in_ifaddr *ia; 1663 char ipbuf[INET_ADDRSTRLEN]; 1664 bool need_free = false; 1665 1666 KERNEL_LOCK_UNLESS_NET_MPSAFE(); 1667 mutex_enter(&arp_dad_lock); 1668 1669 ifa = dp->dad_ifa; 1670 if (ifa == NULL) { 1671 /* dp is being destroyed by someone. Do nothing. */ 1672 goto done; 1673 } 1674 1675 ia = (struct in_ifaddr *)ifa; 1676 if (ia->ia4_flags & IN_IFF_DUPLICATED) { 1677 log(LOG_ERR, "%s: called with duplicate address %s(%s)\n", 1678 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1679 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1680 goto done; 1681 } 1682 if ((ia->ia4_flags & IN_IFF_TENTATIVE) == 0 && dp->dad_arp_acount == 0) 1683 { 1684 log(LOG_ERR, "%s: called with non-tentative address %s(%s)\n", 1685 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1686 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1687 goto done; 1688 } 1689 1690 /* timeouted with IFF_{RUNNING,UP} check */ 1691 if (dp->dad_arp_tcount > dad_maxtry) { 1692 ARPLOG(LOG_INFO, "%s: could not run DAD, driver problem?\n", 1693 if_name(ifa->ifa_ifp)); 1694 1695 arp_dad_stoptimer(dp); 1696 need_free = true; 1697 goto done; 1698 } 1699 1700 /* Need more checks? */ 1701 if (dp->dad_arp_ocount < dp->dad_count) { 1702 int adelay; 1703 1704 /* 1705 * We have more ARP to go. Send ARP packet for DAD. 1706 */ 1707 arp_dad_output(dp, ifa); 1708 if (dp->dad_arp_ocount < dp->dad_count) 1709 adelay = (PROBE_MIN * hz) + 1710 (cprng_fast32() % 1711 ((PROBE_MAX * hz) - (PROBE_MIN * hz))); 1712 else 1713 adelay = ANNOUNCE_WAIT * hz; 1714 arp_dad_starttimer(dp, adelay); 1715 goto done; 1716 } else if (dp->dad_arp_acount == 0) { 1717 /* 1718 * We are done with DAD. 1719 * No duplicate address found. 1720 */ 1721 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1722 rt_addrmsg(RTM_NEWADDR, ifa); 1723 ARPLOG(LOG_DEBUG, 1724 "%s: DAD complete for %s - no duplicates found\n", 1725 if_name(ifa->ifa_ifp), ARPLOGADDR(&ia->ia_addr.sin_addr)); 1726 dp->dad_arp_announce = ANNOUNCE_NUM; 1727 goto announce; 1728 } else if (dp->dad_arp_acount < dp->dad_arp_announce) { 1729 announce: 1730 /* 1731 * Announce the address. 1732 */ 1733 arpannounce1(ifa); 1734 dp->dad_arp_acount++; 1735 if (dp->dad_arp_acount < dp->dad_arp_announce) { 1736 arp_dad_starttimer(dp, ANNOUNCE_INTERVAL * hz); 1737 goto done; 1738 } 1739 ARPLOG(LOG_DEBUG, 1740 "%s: ARP announcement complete for %s\n", 1741 if_name(ifa->ifa_ifp), ARPLOGADDR(&ia->ia_addr.sin_addr)); 1742 } 1743 1744 arp_dad_stoptimer(dp); 1745 need_free = true; 1746 done: 1747 mutex_exit(&arp_dad_lock); 1748 1749 if (need_free) { 1750 arp_dad_destroytimer(dp); 1751 KASSERT(ifa != NULL); 1752 ifafree(ifa); 1753 } 1754 1755 KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 1756 } 1757 1758 static void 1759 arp_dad_duplicated(struct ifaddr *ifa, const struct sockaddr_dl *from) 1760 { 1761 struct in_ifaddr *ia = ifatoia(ifa); 1762 struct ifnet *ifp = ifa->ifa_ifp; 1763 char ipbuf[INET_ADDRSTRLEN], llabuf[LLA_ADDRSTRLEN]; 1764 const char *iastr, *llastr; 1765 1766 iastr = IN_PRINT(ipbuf, &ia->ia_addr.sin_addr); 1767 if (__predict_false(from == NULL)) 1768 llastr = NULL; 1769 else 1770 llastr = lla_snprintf(llabuf, sizeof(llabuf), 1771 CLLADDR(from), from->sdl_alen); 1772 1773 if (ia->ia4_flags & (IN_IFF_TENTATIVE|IN_IFF_DUPLICATED)) { 1774 log(LOG_ERR, 1775 "%s: DAD duplicate address %s from %s\n", 1776 if_name(ifp), iastr, llastr); 1777 } else if (ia->ia_dad_defended == 0 || 1778 ia->ia_dad_defended < time_uptime - DEFEND_INTERVAL) { 1779 ia->ia_dad_defended = time_uptime; 1780 arpannounce1(ifa); 1781 log(LOG_ERR, 1782 "%s: DAD defended address %s from %s\n", 1783 if_name(ifp), iastr, llastr); 1784 return; 1785 } else { 1786 /* If DAD is disabled, just report the duplicate. */ 1787 if (!ip_dad_enabled()) { 1788 log(LOG_ERR, 1789 "%s: DAD ignoring duplicate address %s from %s\n", 1790 if_name(ifp), iastr, llastr); 1791 return; 1792 } 1793 log(LOG_ERR, 1794 "%s: DAD defence failed for %s from %s\n", 1795 if_name(ifp), iastr, llastr); 1796 } 1797 1798 arp_dad_stop(ifa); 1799 1800 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1801 if ((ia->ia4_flags & IN_IFF_DUPLICATED) == 0) { 1802 ia->ia4_flags |= IN_IFF_DUPLICATED; 1803 /* Inform the routing socket of the duplicate address */ 1804 rt_addrmsg_src(RTM_NEWADDR, ifa, (const struct sockaddr *)from); 1805 } 1806 } 1807 1808 /* 1809 * Called from 10 Mb/s Ethernet interrupt handlers 1810 * when ether packet type ETHERTYPE_REVARP 1811 * is received. Common length and type checks are done here, 1812 * then the protocol-specific routine is called. 1813 */ 1814 void 1815 revarpinput(struct mbuf *m) 1816 { 1817 struct arphdr *ar; 1818 int arplen; 1819 1820 arplen = sizeof(struct arphdr); 1821 if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL) 1822 return; 1823 ar = mtod(m, struct arphdr *); 1824 1825 if (ntohs(ar->ar_hrd) == ARPHRD_IEEE1394) { 1826 goto out; 1827 } 1828 1829 arplen = sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln); 1830 if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL) 1831 return; 1832 ar = mtod(m, struct arphdr *); 1833 1834 switch (ntohs(ar->ar_pro)) { 1835 case ETHERTYPE_IP: 1836 case ETHERTYPE_IPTRAILERS: 1837 in_revarpinput(m); 1838 return; 1839 1840 default: 1841 break; 1842 } 1843 1844 out: 1845 m_freem(m); 1846 } 1847 1848 /* 1849 * RARP for Internet protocols on 10 Mb/s Ethernet. 1850 * Algorithm is that given in RFC 903. 1851 * We are only using for bootstrap purposes to get an ip address for one of 1852 * our interfaces. Thus we support no user-interface. 1853 * 1854 * Since the contents of the RARP reply are specific to the interface that 1855 * sent the request, this code must ensure that they are properly associated. 1856 * 1857 * Note: also supports ARP via RARP packets, per the RFC. 1858 */ 1859 void 1860 in_revarpinput(struct mbuf *m) 1861 { 1862 struct arphdr *ah; 1863 void *tha; 1864 int op; 1865 struct ifnet *rcvif; 1866 int s; 1867 1868 ah = mtod(m, struct arphdr *); 1869 op = ntohs(ah->ar_op); 1870 1871 rcvif = m_get_rcvif(m, &s); 1872 if (__predict_false(rcvif == NULL)) 1873 goto out; 1874 if (rcvif->if_flags & IFF_NOARP) 1875 goto out; 1876 1877 switch (rcvif->if_type) { 1878 case IFT_IEEE1394: 1879 /* ARP without target hardware address is not supported */ 1880 goto out; 1881 default: 1882 break; 1883 } 1884 1885 switch (op) { 1886 case ARPOP_REQUEST: 1887 case ARPOP_REPLY: /* per RFC */ 1888 m_put_rcvif(rcvif, &s); 1889 in_arpinput(m); 1890 return; 1891 case ARPOP_REVREPLY: 1892 break; 1893 case ARPOP_REVREQUEST: /* handled by rarpd(8) */ 1894 default: 1895 goto out; 1896 } 1897 if (!revarp_in_progress) 1898 goto out; 1899 if (rcvif != myip_ifp) /* !same interface */ 1900 goto out; 1901 if (myip_initialized) 1902 goto wake; 1903 tha = ar_tha(ah); 1904 if (tha == NULL) 1905 goto out; 1906 if (ah->ar_pln != sizeof(struct in_addr)) 1907 goto out; 1908 if (ah->ar_hln != rcvif->if_sadl->sdl_alen) 1909 goto out; 1910 if (memcmp(tha, CLLADDR(rcvif->if_sadl), rcvif->if_sadl->sdl_alen)) 1911 goto out; 1912 memcpy(&srv_ip, ar_spa(ah), sizeof(srv_ip)); 1913 memcpy(&myip, ar_tpa(ah), sizeof(myip)); 1914 myip_initialized = 1; 1915 wake: /* Do wakeup every time in case it was missed. */ 1916 wakeup((void *)&myip); 1917 1918 out: 1919 m_put_rcvif(rcvif, &s); 1920 m_freem(m); 1921 } 1922 1923 /* 1924 * Send a RARP request for the ip address of the specified interface. 1925 * The request should be RFC 903-compliant. 1926 */ 1927 static void 1928 revarprequest(struct ifnet *ifp) 1929 { 1930 struct sockaddr sa; 1931 struct mbuf *m; 1932 struct arphdr *ah; 1933 void *tha; 1934 1935 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 1936 return; 1937 MCLAIM(m, &arpdomain.dom_mowner); 1938 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) + 1939 2*ifp->if_addrlen; 1940 m->m_pkthdr.len = m->m_len; 1941 m_align(m, m->m_len); 1942 ah = mtod(m, struct arphdr *); 1943 memset(ah, 0, m->m_len); 1944 ah->ar_pro = htons(ETHERTYPE_IP); 1945 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 1946 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 1947 ah->ar_op = htons(ARPOP_REVREQUEST); 1948 1949 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1950 tha = ar_tha(ah); 1951 if (tha == NULL) { 1952 m_free(m); 1953 return; 1954 } 1955 memcpy(tha, CLLADDR(ifp->if_sadl), ah->ar_hln); 1956 1957 sa.sa_family = AF_ARP; 1958 sa.sa_len = 2; 1959 m->m_flags |= M_BCAST; 1960 1961 if_output_lock(ifp, ifp, m, &sa, NULL); 1962 } 1963 1964 /* 1965 * RARP for the ip address of the specified interface, but also 1966 * save the ip address of the server that sent the answer. 1967 * Timeout if no response is received. 1968 */ 1969 int 1970 revarpwhoarewe(struct ifnet *ifp, struct in_addr *serv_in, 1971 struct in_addr *clnt_in) 1972 { 1973 int result, count = 20; 1974 1975 myip_initialized = 0; 1976 myip_ifp = ifp; 1977 1978 revarp_in_progress = 1; 1979 while (count--) { 1980 revarprequest(ifp); 1981 result = tsleep((void *)&myip, PSOCK, "revarp", hz/2); 1982 if (result != EWOULDBLOCK) 1983 break; 1984 } 1985 revarp_in_progress = 0; 1986 1987 if (!myip_initialized) 1988 return ENETUNREACH; 1989 1990 memcpy(serv_in, &srv_ip, sizeof(*serv_in)); 1991 memcpy(clnt_in, &myip, sizeof(*clnt_in)); 1992 return 0; 1993 } 1994 1995 void 1996 arp_stat_add(int type, uint64_t count) 1997 { 1998 ARP_STATADD(type, count); 1999 } 2000 2001 static int 2002 sysctl_net_inet_arp_stats(SYSCTLFN_ARGS) 2003 { 2004 2005 return NETSTAT_SYSCTL(arpstat_percpu, ARP_NSTATS); 2006 } 2007 2008 static void 2009 sysctl_net_inet_arp_setup(struct sysctllog **clog) 2010 { 2011 const struct sysctlnode *node; 2012 2013 sysctl_createv(clog, 0, NULL, NULL, 2014 CTLFLAG_PERMANENT, 2015 CTLTYPE_NODE, "inet", NULL, 2016 NULL, 0, NULL, 0, 2017 CTL_NET, PF_INET, CTL_EOL); 2018 sysctl_createv(clog, 0, NULL, &node, 2019 CTLFLAG_PERMANENT, 2020 CTLTYPE_NODE, "arp", 2021 SYSCTL_DESCR("Address Resolution Protocol"), 2022 NULL, 0, NULL, 0, 2023 CTL_NET, PF_INET, CTL_CREATE, CTL_EOL); 2024 2025 sysctl_createv(clog, 0, NULL, NULL, 2026 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2027 CTLTYPE_INT, "nd_delay", 2028 SYSCTL_DESCR("First probe delay time"), 2029 NULL, 0, &arp_nd_domain.nd_delay, 0, 2030 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2031 sysctl_createv(clog, 0, NULL, NULL, 2032 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2033 CTLTYPE_INT, "nd_bmaxtries", 2034 SYSCTL_DESCR("Number of broadcast discovery attempts"), 2035 NULL, 0, &arp_nd_domain.nd_mmaxtries, 0, 2036 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2037 sysctl_createv(clog, 0, NULL, NULL, 2038 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2039 CTLTYPE_INT, "nd_umaxtries", 2040 SYSCTL_DESCR("Number of unicast discovery attempts"), 2041 NULL, 0, &arp_nd_domain.nd_umaxtries, 0, 2042 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2043 sysctl_createv(clog, 0, NULL, NULL, 2044 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2045 CTLTYPE_INT, "nd_reachable", 2046 SYSCTL_DESCR("Reachable time"), 2047 NULL, 0, &arp_reachable, 0, 2048 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2049 sysctl_createv(clog, 0, NULL, NULL, 2050 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2051 CTLTYPE_INT, "nd_retrans", 2052 SYSCTL_DESCR("Retransmission time"), 2053 NULL, 0, &arp_retrans, 0, 2054 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2055 sysctl_createv(clog, 0, NULL, NULL, 2056 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2057 CTLTYPE_INT, "nd_nud", 2058 SYSCTL_DESCR("Perform neighbour unreachability detection"), 2059 NULL, 0, &arp_perform_nud, 0, 2060 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2061 sysctl_createv(clog, 0, NULL, NULL, 2062 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2063 CTLTYPE_INT, "nd_maxnudhint", 2064 SYSCTL_DESCR("Maximum neighbor unreachable hint count"), 2065 NULL, 0, &arp_nd_domain.nd_maxnudhint, 0, 2066 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2067 sysctl_createv(clog, 0, NULL, NULL, 2068 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2069 CTLTYPE_INT, "maxqueuelen", 2070 SYSCTL_DESCR("max packet queue len for a unresolved ARP"), 2071 NULL, 1, &arp_nd_domain.nd_maxqueuelen, 0, 2072 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2073 2074 sysctl_createv(clog, 0, NULL, NULL, 2075 CTLFLAG_PERMANENT, 2076 CTLTYPE_STRUCT, "stats", 2077 SYSCTL_DESCR("ARP statistics"), 2078 sysctl_net_inet_arp_stats, 0, NULL, 0, 2079 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2080 2081 sysctl_createv(clog, 0, NULL, NULL, 2082 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2083 CTLTYPE_INT, "log_movements", 2084 SYSCTL_DESCR("log ARP replies from MACs different than" 2085 " the one in the cache"), 2086 NULL, 0, &log_movements, 0, 2087 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2088 2089 sysctl_createv(clog, 0, NULL, NULL, 2090 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2091 CTLTYPE_INT, "log_permanent_modify", 2092 SYSCTL_DESCR("log ARP replies from MACs different than" 2093 " the one in the permanent arp entry"), 2094 NULL, 0, &log_permanent_modify, 0, 2095 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2096 2097 sysctl_createv(clog, 0, NULL, NULL, 2098 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2099 CTLTYPE_INT, "log_wrong_iface", 2100 SYSCTL_DESCR("log ARP packets arriving on the wrong" 2101 " interface"), 2102 NULL, 0, &log_wrong_iface, 0, 2103 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2104 2105 sysctl_createv(clog, 0, NULL, NULL, 2106 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2107 CTLTYPE_INT, "debug", 2108 SYSCTL_DESCR("Enable ARP DAD debug output"), 2109 NULL, 0, &arp_debug, 0, 2110 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2111 } 2112 2113 #endif /* INET */ 2114
Indexes created Tue Nov 10 00:26:44 UTC 2026