if_arp.c revision 1.300
1 /* $NetBSD: if_arp.c,v 1.300 2021/02/13 13:00:16 roy Exp $ */ 2 3 /* 4 * Copyright (c) 1998, 2000, 2008 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Public Access Networks Corporation ("Panix"). It was developed under 9 * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 /* 34 * Copyright (c) 1982, 1986, 1988, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 3. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * @(#)if_ether.c 8.2 (Berkeley) 9/26/94 62 */ 63 64 /* 65 * Ethernet address resolution protocol. 66 * TODO: 67 * add "inuse/lock" bit (or ref. count) along with valid bit 68 */ 69 70 #include <sys/cdefs.h> 71 __KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.300 2021/02/13 13:00:16 roy Exp $"); 72 73 #ifdef _KERNEL_OPT 74 #include "opt_ddb.h" 75 #include "opt_inet.h" 76 #include "opt_net_mpsafe.h" 77 #endif 78 79 #ifdef INET 80 81 #include "arp.h" 82 #include "bridge.h" 83 84 #include <sys/param.h> 85 #include <sys/systm.h> 86 #include <sys/callout.h> 87 #include <sys/kmem.h> 88 #include <sys/mbuf.h> 89 #include <sys/socket.h> 90 #include <sys/time.h> 91 #include <sys/timetc.h> 92 #include <sys/kernel.h> 93 #include <sys/errno.h> 94 #include <sys/ioctl.h> 95 #include <sys/syslog.h> 96 #include <sys/proc.h> 97 #include <sys/protosw.h> 98 #include <sys/domain.h> 99 #include <sys/sysctl.h> 100 #include <sys/socketvar.h> 101 #include <sys/percpu.h> 102 #include <sys/cprng.h> 103 #include <sys/kmem.h> 104 105 #include <net/ethertypes.h> 106 #include <net/if.h> 107 #include <net/if_dl.h> 108 #include <net/if_types.h> 109 #include <net/if_ether.h> 110 #include <net/if_llatbl.h> 111 #include <net/nd.h> 112 #include <net/route.h> 113 #include <net/net_stats.h> 114 115 #include <netinet/in.h> 116 #include <netinet/in_systm.h> 117 #include <netinet/in_var.h> 118 #include <netinet/ip.h> 119 #include <netinet/if_inarp.h> 120 121 #include "arcnet.h" 122 #if NARCNET > 0 123 #include <net/if_arc.h> 124 #endif 125 #include "carp.h" 126 #if NCARP > 0 127 #include <netinet/ip_carp.h> 128 #endif 129 130 /* 131 * ARP trailer negotiation. Trailer protocol is not IP specific, 132 * but ARP request/response use IP addresses. 133 */ 134 #define ETHERTYPE_IPTRAILERS ETHERTYPE_TRAIL 135 136 /* timers */ 137 static int arp_reachable = REACHABLE_TIME; 138 static int arp_retrans = RETRANS_TIMER; 139 static int arp_perform_nud = 1; 140 141 static bool arp_nud_enabled(struct ifnet *); 142 static unsigned int arp_llinfo_reachable(struct ifnet *); 143 static unsigned int arp_llinfo_retrans(struct ifnet *); 144 static union l3addr *arp_llinfo_holdsrc(struct llentry *, union l3addr *); 145 static void arp_llinfo_output(struct ifnet *, const union l3addr *, 146 const union l3addr *, const uint8_t *, const union l3addr *); 147 static void arp_llinfo_missed(struct ifnet *, const union l3addr *, 148 int16_t, struct mbuf *); 149 static void arp_free(struct llentry *, int); 150 151 static struct nd_domain arp_nd_domain = { 152 .nd_family = AF_INET, 153 .nd_delay = 5, /* delay first probe time 5 second */ 154 .nd_mmaxtries = 3, /* maximum broadcast query */ 155 .nd_umaxtries = 3, /* maximum unicast query */ 156 .nd_retransmultiple = BACKOFF_MULTIPLE, 157 .nd_maxretrans = MAX_RETRANS_TIMER, 158 .nd_maxnudhint = 0, /* max # of subsequent upper layer hints */ 159 .nd_maxqueuelen = 1, /* max # of packets in unresolved ND entries */ 160 .nd_nud_enabled = arp_nud_enabled, 161 .nd_reachable = arp_llinfo_reachable, 162 .nd_retrans = arp_llinfo_retrans, 163 .nd_holdsrc = arp_llinfo_holdsrc, 164 .nd_output = arp_llinfo_output, 165 .nd_missed = arp_llinfo_missed, 166 .nd_free = arp_free, 167 }; 168 169 int ip_dad_count = PROBE_NUM; 170 #ifdef ARP_DEBUG 171 int arp_debug = 1; 172 #else 173 int arp_debug = 0; 174 #endif 175 176 static void arp_init(void); 177 static void arp_dad_init(void); 178 179 static void arprequest(struct ifnet *, 180 const struct in_addr *, const struct in_addr *, 181 const uint8_t *, const uint8_t *); 182 static void arpannounce1(struct ifaddr *); 183 static struct sockaddr *arp_setgate(struct rtentry *, struct sockaddr *, 184 const struct sockaddr *); 185 static struct llentry *arpcreate(struct ifnet *, 186 const struct in_addr *, const struct sockaddr *, int); 187 static void in_arpinput(struct mbuf *); 188 static void in_revarpinput(struct mbuf *); 189 static void revarprequest(struct ifnet *); 190 191 static void arp_drainstub(void); 192 193 struct dadq; 194 static void arp_dad_timer(struct dadq *); 195 static void arp_dad_start(struct ifaddr *); 196 static void arp_dad_stop(struct ifaddr *); 197 static void arp_dad_duplicated(struct ifaddr *, const struct sockaddr_dl *); 198 199 struct ifqueue arpintrq = { 200 .ifq_head = NULL, 201 .ifq_tail = NULL, 202 .ifq_len = 0, 203 .ifq_maxlen = 50, 204 .ifq_drops = 0, 205 }; 206 static int useloopback = 1; /* use loopback interface for local traffic */ 207 208 static percpu_t *arpstat_percpu; 209 210 #define ARP_STAT_GETREF() _NET_STAT_GETREF(arpstat_percpu) 211 #define ARP_STAT_PUTREF() _NET_STAT_PUTREF(arpstat_percpu) 212 213 #define ARP_STATINC(x) _NET_STATINC(arpstat_percpu, x) 214 #define ARP_STATADD(x, v) _NET_STATADD(arpstat_percpu, x, v) 215 216 /* revarp state */ 217 static struct in_addr myip, srv_ip; 218 static int myip_initialized = 0; 219 static int revarp_in_progress = 0; 220 static struct ifnet *myip_ifp = NULL; 221 222 static int arp_drainwanted; 223 224 static int log_movements = 0; 225 static int log_permanent_modify = 1; 226 static int log_wrong_iface = 1; 227 228 DOMAIN_DEFINE(arpdomain); /* forward declare and add to link set */ 229 230 static void 231 arp_fasttimo(void) 232 { 233 if (arp_drainwanted) { 234 arp_drain(); 235 arp_drainwanted = 0; 236 } 237 } 238 239 static const struct protosw arpsw[] = { 240 { 241 .pr_type = 0, 242 .pr_domain = &arpdomain, 243 .pr_protocol = 0, 244 .pr_flags = 0, 245 .pr_input = 0, 246 .pr_ctlinput = 0, 247 .pr_ctloutput = 0, 248 .pr_usrreqs = 0, 249 .pr_init = arp_init, 250 .pr_fasttimo = arp_fasttimo, 251 .pr_slowtimo = 0, 252 .pr_drain = arp_drainstub, 253 } 254 }; 255 256 struct domain arpdomain = { 257 .dom_family = PF_ARP, 258 .dom_name = "arp", 259 .dom_protosw = arpsw, 260 .dom_protoswNPROTOSW = &arpsw[__arraycount(arpsw)], 261 #ifdef MBUFTRACE 262 .dom_mowner = MOWNER_INIT("internet", "arp"), 263 #endif 264 }; 265 266 static void sysctl_net_inet_arp_setup(struct sysctllog **); 267 268 void 269 arp_init(void) 270 { 271 272 sysctl_net_inet_arp_setup(NULL); 273 arpstat_percpu = percpu_alloc(sizeof(uint64_t) * ARP_NSTATS); 274 IFQ_LOCK_INIT(&arpintrq); 275 276 #ifdef MBUFTRACE 277 MOWNER_ATTACH(&arpdomain.dom_mowner); 278 #endif 279 280 nd_attach_domain(&arp_nd_domain); 281 arp_dad_init(); 282 } 283 284 static void 285 arp_drainstub(void) 286 { 287 arp_drainwanted = 1; 288 } 289 290 /* 291 * ARP protocol drain routine. Called when memory is in short supply. 292 * Called at splvm(); don't acquire softnet_lock as can be called from 293 * hardware interrupt handlers. 294 */ 295 void 296 arp_drain(void) 297 { 298 299 lltable_drain(AF_INET); 300 } 301 302 /* 303 * We set the gateway for RTF_CLONING routes to a "prototype" 304 * link-layer sockaddr whose interface type (if_type) and interface 305 * index (if_index) fields are prepared. 306 */ 307 static struct sockaddr * 308 arp_setgate(struct rtentry *rt, struct sockaddr *gate, 309 const struct sockaddr *netmask) 310 { 311 const struct ifnet *ifp = rt->rt_ifp; 312 uint8_t namelen = strlen(ifp->if_xname); 313 uint8_t addrlen = ifp->if_addrlen; 314 315 /* 316 * XXX: If this is a manually added route to interface 317 * such as older version of routed or gated might provide, 318 * restore cloning bit. 319 */ 320 if ((rt->rt_flags & RTF_HOST) == 0 && netmask != NULL && 321 satocsin(netmask)->sin_addr.s_addr != 0xffffffff) 322 rt->rt_flags |= RTF_CONNECTED; 323 324 if ((rt->rt_flags & (RTF_CONNECTED | RTF_LOCAL))) { 325 union { 326 struct sockaddr sa; 327 struct sockaddr_storage ss; 328 struct sockaddr_dl sdl; 329 } u; 330 /* 331 * Case 1: This route should come from a route to iface. 332 */ 333 sockaddr_dl_init(&u.sdl, sizeof(u.ss), 334 ifp->if_index, ifp->if_type, NULL, namelen, NULL, addrlen); 335 rt_setgate(rt, &u.sa); 336 gate = rt->rt_gateway; 337 } 338 return gate; 339 } 340 341 /* 342 * Parallel to llc_rtrequest. 343 */ 344 void 345 arp_rtrequest(int req, struct rtentry *rt, const struct rt_addrinfo *info) 346 { 347 struct sockaddr *gate = rt->rt_gateway; 348 struct in_ifaddr *ia; 349 struct ifaddr *ifa; 350 struct ifnet *ifp = rt->rt_ifp; 351 int bound; 352 int s; 353 354 if (req == RTM_LLINFO_UPD) { 355 if ((ifa = info->rti_ifa) != NULL) 356 arpannounce1(ifa); 357 return; 358 } 359 360 if ((rt->rt_flags & RTF_GATEWAY) != 0) { 361 if (req != RTM_ADD) 362 return; 363 364 /* 365 * linklayers with particular link MTU limitation. 366 */ 367 switch(ifp->if_type) { 368 #if NARCNET > 0 369 case IFT_ARCNET: 370 { 371 int arcipifmtu; 372 373 if (ifp->if_flags & IFF_LINK0) 374 arcipifmtu = arc_ipmtu; 375 else 376 arcipifmtu = ARCMTU; 377 if (ifp->if_mtu > arcipifmtu) 378 rt->rt_rmx.rmx_mtu = arcipifmtu; 379 break; 380 } 381 #endif 382 } 383 return; 384 } 385 386 switch (req) { 387 case RTM_SETGATE: 388 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 389 break; 390 case RTM_ADD: 391 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 392 if (gate == NULL) { 393 log(LOG_ERR, "%s: arp_setgate failed\n", __func__); 394 break; 395 } 396 if ((rt->rt_flags & RTF_CONNECTED) || 397 (rt->rt_flags & RTF_LOCAL)) { 398 /* 399 * linklayers with particular link MTU limitation. 400 */ 401 switch (ifp->if_type) { 402 #if NARCNET > 0 403 case IFT_ARCNET: 404 { 405 int arcipifmtu; 406 if (ifp->if_flags & IFF_LINK0) 407 arcipifmtu = arc_ipmtu; 408 else 409 arcipifmtu = ARCMTU; 410 411 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 412 (rt->rt_rmx.rmx_mtu > arcipifmtu || 413 (rt->rt_rmx.rmx_mtu == 0 && 414 ifp->if_mtu > arcipifmtu))) 415 rt->rt_rmx.rmx_mtu = arcipifmtu; 416 break; 417 } 418 #endif 419 } 420 if (rt->rt_flags & RTF_CONNECTED) 421 break; 422 } 423 424 bound = curlwp_bind(); 425 /* Announce a new entry if requested. */ 426 if (rt->rt_flags & RTF_ANNOUNCE) { 427 struct psref psref; 428 ia = in_get_ia_on_iface_psref( 429 satocsin(rt_getkey(rt))->sin_addr, ifp, &psref); 430 if (ia != NULL) { 431 arpannounce(ifp, &ia->ia_ifa, 432 CLLADDR(satocsdl(gate))); 433 ia4_release(ia, &psref); 434 } 435 } 436 437 if (gate->sa_family != AF_LINK || 438 gate->sa_len < sockaddr_dl_measure(0, ifp->if_addrlen)) { 439 log(LOG_DEBUG, "%s: bad gateway value\n", __func__); 440 goto out; 441 } 442 443 satosdl(gate)->sdl_type = ifp->if_type; 444 satosdl(gate)->sdl_index = ifp->if_index; 445 446 /* 447 * If the route is for a broadcast address mark it as such. 448 * This way we can avoid an expensive call to in_broadcast() 449 * in ip_output() most of the time (because the route passed 450 * to ip_output() is almost always a host route). 451 */ 452 if (rt->rt_flags & RTF_HOST && 453 !(rt->rt_flags & RTF_BROADCAST) && 454 in_broadcast(satocsin(rt_getkey(rt))->sin_addr, rt->rt_ifp)) 455 rt->rt_flags |= RTF_BROADCAST; 456 /* There is little point in resolving the broadcast address */ 457 if (rt->rt_flags & RTF_BROADCAST) 458 goto out; 459 460 /* 461 * When called from rt_ifa_addlocal, we cannot depend on that 462 * the address (rt_getkey(rt)) exits in the address list of the 463 * interface. So check RTF_LOCAL instead. 464 */ 465 if (rt->rt_flags & RTF_LOCAL) { 466 if (useloopback) { 467 rt->rt_ifp = lo0ifp; 468 rt->rt_rmx.rmx_mtu = 0; 469 } 470 goto out; 471 } 472 473 s = pserialize_read_enter(); 474 ia = in_get_ia_on_iface(satocsin(rt_getkey(rt))->sin_addr, ifp); 475 if (ia == NULL) { 476 pserialize_read_exit(s); 477 goto out; 478 } 479 480 if (useloopback) { 481 rt->rt_ifp = lo0ifp; 482 rt->rt_rmx.rmx_mtu = 0; 483 } 484 rt->rt_flags |= RTF_LOCAL; 485 486 if (ISSET(info->rti_flags, RTF_DONTCHANGEIFA)) { 487 pserialize_read_exit(s); 488 goto out; 489 } 490 /* 491 * make sure to set rt->rt_ifa to the interface 492 * address we are using, otherwise we will have trouble 493 * with source address selection. 494 */ 495 ifa = &ia->ia_ifa; 496 if (ifa != rt->rt_ifa) 497 /* Assume it doesn't sleep */ 498 rt_replace_ifa(rt, ifa); 499 pserialize_read_exit(s); 500 out: 501 curlwp_bindx(bound); 502 break; 503 } 504 } 505 506 /* 507 * Broadcast an ARP request. Caller specifies: 508 * - arp header source ip address 509 * - arp header target ip address 510 * - arp header source ethernet address 511 */ 512 static void 513 arprequest(struct ifnet *ifp, 514 const struct in_addr *sip, const struct in_addr *tip, 515 const uint8_t *saddr, const uint8_t *taddr) 516 { 517 struct mbuf *m; 518 struct arphdr *ah; 519 struct sockaddr sa; 520 uint64_t *arps; 521 522 KASSERT(sip != NULL); 523 KASSERT(tip != NULL); 524 KASSERT(saddr != NULL); 525 526 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 527 return; 528 MCLAIM(m, &arpdomain.dom_mowner); 529 switch (ifp->if_type) { 530 case IFT_IEEE1394: 531 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 532 ifp->if_addrlen; 533 break; 534 default: 535 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 536 2 * ifp->if_addrlen; 537 break; 538 } 539 m->m_pkthdr.len = m->m_len; 540 m_align(m, m->m_len); 541 ah = mtod(m, struct arphdr *); 542 memset(ah, 0, m->m_len); 543 switch (ifp->if_type) { 544 case IFT_IEEE1394: /* RFC2734 */ 545 /* fill it now for ar_tpa computation */ 546 ah->ar_hrd = htons(ARPHRD_IEEE1394); 547 break; 548 default: 549 /* ifp->if_output will fill ar_hrd */ 550 break; 551 } 552 ah->ar_pro = htons(ETHERTYPE_IP); 553 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 554 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 555 ah->ar_op = htons(ARPOP_REQUEST); 556 memcpy(ar_sha(ah), saddr, ah->ar_hln); 557 if (taddr == NULL) 558 m->m_flags |= M_BCAST; 559 else 560 memcpy(ar_tha(ah), taddr, ah->ar_hln); 561 memcpy(ar_spa(ah), sip, ah->ar_pln); 562 memcpy(ar_tpa(ah), tip, ah->ar_pln); 563 sa.sa_family = AF_ARP; 564 sa.sa_len = 2; 565 arps = ARP_STAT_GETREF(); 566 arps[ARP_STAT_SNDTOTAL]++; 567 arps[ARP_STAT_SENDREQUEST]++; 568 ARP_STAT_PUTREF(); 569 if_output_lock(ifp, ifp, m, &sa, NULL); 570 } 571 572 void 573 arpannounce(struct ifnet *ifp, struct ifaddr *ifa, const uint8_t *enaddr) 574 { 575 struct in_ifaddr *ia = ifatoia(ifa); 576 struct in_addr *ip = &IA_SIN(ifa)->sin_addr; 577 578 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) { 579 ARPLOG(LOG_DEBUG, "%s not ready\n", ARPLOGADDR(ip)); 580 return; 581 } 582 arprequest(ifp, ip, ip, enaddr, NULL); 583 } 584 585 static void 586 arpannounce1(struct ifaddr *ifa) 587 { 588 589 arpannounce(ifa->ifa_ifp, ifa, CLLADDR(ifa->ifa_ifp->if_sadl)); 590 } 591 592 /* 593 * Resolve an IP address into an ethernet address. If success, desten is 594 * filled in. If there is no entry in arptab, set one up and broadcast a 595 * request for the IP address. Hold onto this mbuf and resend it once the 596 * address is finally resolved. 597 * 598 * A return value of 0 indicates that desten has been filled in and the packet 599 * should be sent normally; a return value of EWOULDBLOCK indicates that the 600 * packet has been held pending resolution. Any other value indicates an 601 * error. 602 */ 603 int 604 arpresolve(struct ifnet *ifp, const struct rtentry *rt, struct mbuf *m, 605 const struct sockaddr *dst, void *desten, size_t destlen) 606 { 607 struct llentry *la; 608 const char *create_lookup; 609 int error; 610 611 #if NCARP > 0 612 if (rt != NULL && rt->rt_ifp->if_type == IFT_CARP) 613 ifp = rt->rt_ifp; 614 #endif 615 616 KASSERT(m != NULL); 617 618 la = arplookup(ifp, NULL, dst, 0); 619 if (la == NULL) 620 goto notfound; 621 622 if (la->la_flags & LLE_VALID && la->ln_state == ND_LLINFO_REACHABLE) { 623 KASSERT(destlen >= ifp->if_addrlen); 624 memcpy(desten, &la->ll_addr, ifp->if_addrlen); 625 LLE_RUNLOCK(la); 626 return 0; 627 } 628 629 notfound: 630 if (ifp->if_flags & IFF_NOARP) { 631 if (la != NULL) 632 LLE_RUNLOCK(la); 633 error = ENOTSUP; 634 goto bad; 635 } 636 637 if (la == NULL) { 638 struct rtentry *_rt; 639 640 create_lookup = "create"; 641 _rt = rtalloc1(dst, 0); 642 IF_AFDATA_WLOCK(ifp); 643 la = lla_create(LLTABLE(ifp), LLE_EXCLUSIVE, dst, _rt); 644 IF_AFDATA_WUNLOCK(ifp); 645 if (_rt != NULL) 646 rt_unref(_rt); 647 if (la == NULL) 648 ARP_STATINC(ARP_STAT_ALLOCFAIL); 649 else 650 la->ln_state = ND_LLINFO_NOSTATE; 651 } else if (LLE_TRY_UPGRADE(la) == 0) { 652 create_lookup = "lookup"; 653 LLE_RUNLOCK(la); 654 IF_AFDATA_RLOCK(ifp); 655 la = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst); 656 IF_AFDATA_RUNLOCK(ifp); 657 } 658 659 error = EINVAL; 660 if (la == NULL) { 661 log(LOG_DEBUG, 662 "%s: failed to %s llentry for %s on %s\n", 663 __func__, create_lookup, inet_ntoa(satocsin(dst)->sin_addr), 664 ifp->if_xname); 665 goto bad; 666 } 667 668 error = nd_resolve(la, rt, m, desten, destlen); 669 return error; 670 671 bad: 672 m_freem(m); 673 return error; 674 } 675 676 /* 677 * Common length and type checks are done here, 678 * then the protocol-specific routine is called. 679 */ 680 void 681 arpintr(void) 682 { 683 struct mbuf *m; 684 struct arphdr *ar; 685 int s; 686 int arplen; 687 688 SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE(); 689 for (;;) { 690 struct ifnet *rcvif; 691 692 IFQ_LOCK(&arpintrq); 693 IF_DEQUEUE(&arpintrq, m); 694 IFQ_UNLOCK(&arpintrq); 695 if (m == NULL) 696 goto out; 697 if ((m->m_flags & M_PKTHDR) == 0) 698 panic("arpintr"); 699 700 MCLAIM(m, &arpdomain.dom_mowner); 701 ARP_STATINC(ARP_STAT_RCVTOTAL); 702 703 /* Enforce alignment */ 704 if (ARP_HDR_ALIGNED_P(mtod(m, void *)) == 0) { 705 if ((m = m_copyup(m, sizeof(*ar), 0)) == NULL) 706 goto badlen; 707 } else if (__predict_false(m->m_len < sizeof(*ar))) { 708 if ((m = m_pullup(m, sizeof(*ar))) == NULL) 709 goto badlen; 710 } 711 ar = mtod(m, struct arphdr *); 712 713 rcvif = m_get_rcvif(m, &s); 714 if (__predict_false(rcvif == NULL)) { 715 ARP_STATINC(ARP_STAT_RCVNOINT); 716 goto free; 717 } 718 719 /* 720 * We don't want non-IEEE1394 ARP packets on IEEE1394 721 * interfaces, and vice versa. Our life depends on that. 722 */ 723 switch (rcvif->if_type) { 724 case IFT_IEEE1394: 725 if (ntohs(ar->ar_hrd) != ARPHRD_IEEE1394) { 726 m_put_rcvif(rcvif, &s); 727 ARP_STATINC(ARP_STAT_RCVBADPROTO); 728 goto free; 729 } 730 break; 731 default: 732 if (ntohs(ar->ar_hrd) == ARPHRD_IEEE1394) { 733 m_put_rcvif(rcvif, &s); 734 ARP_STATINC(ARP_STAT_RCVBADPROTO); 735 goto free; 736 } 737 break; 738 } 739 740 m_put_rcvif(rcvif, &s); 741 742 arplen = sizeof(*ar) + 2 * ar->ar_hln + 2 * ar->ar_pln; 743 if (m->m_len < arplen) { 744 if ((m = m_pullup(m, arplen)) == NULL) 745 goto badlen; 746 ar = mtod(m, struct arphdr *); 747 KASSERT(ARP_HDR_ALIGNED_P(ar)); 748 } 749 750 switch (ntohs(ar->ar_pro)) { 751 case ETHERTYPE_IP: 752 case ETHERTYPE_IPTRAILERS: 753 in_arpinput(m); 754 continue; 755 default: 756 ARP_STATINC(ARP_STAT_RCVBADPROTO); 757 goto free; 758 } 759 760 badlen: 761 ARP_STATINC(ARP_STAT_RCVBADLEN); 762 free: 763 m_freem(m); 764 } 765 766 out: 767 SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 768 return; /* XXX gcc */ 769 } 770 771 /* 772 * ARP for Internet protocols on 10 Mb/s Ethernet. Algorithm is that given in 773 * RFC 826. In addition, a sanity check is performed on the sender protocol 774 * address, to catch impersonators. 775 * 776 * We no longer handle negotiations for use of trailer protocol: formerly, ARP 777 * replied for protocol type ETHERTYPE_TRAIL sent along with IP replies if we 778 * wanted trailers sent to us, and also sent them in response to IP replies. 779 * This allowed either end to announce the desire to receive trailer packets. 780 * 781 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, but 782 * formerly didn't normally send requests. 783 */ 784 static void 785 in_arpinput(struct mbuf *m) 786 { 787 struct arphdr *ah; 788 struct ifnet *ifp, *rcvif = NULL; 789 struct llentry *la = NULL; 790 struct in_ifaddr *ia = NULL; 791 #if NBRIDGE > 0 792 struct in_ifaddr *bridge_ia = NULL; 793 #endif 794 #if NCARP > 0 795 uint32_t count = 0, index = 0; 796 #endif 797 struct sockaddr sa; 798 struct in_addr isaddr, itaddr, myaddr; 799 int op, rt_cmd, new_state = 0; 800 void *tha; 801 uint64_t *arps; 802 struct psref psref, psref_ia; 803 int s; 804 char ipbuf[INET_ADDRSTRLEN]; 805 bool find_source, do_dad; 806 807 if (__predict_false(m_makewritable(&m, 0, m->m_pkthdr.len, M_DONTWAIT))) 808 goto out; 809 ah = mtod(m, struct arphdr *); 810 op = ntohs(ah->ar_op); 811 812 if (ah->ar_pln != sizeof(struct in_addr)) 813 goto out; 814 815 ifp = if_get_bylla(ar_sha(ah), ah->ar_hln, &psref); 816 if (ifp) { 817 /* it's from me, ignore it. */ 818 if_put(ifp, &psref); 819 ARP_STATINC(ARP_STAT_RCVLOCALSHA); 820 goto out; 821 } 822 823 rcvif = ifp = m_get_rcvif_psref(m, &psref); 824 if (__predict_false(rcvif == NULL)) 825 goto out; 826 if (rcvif->if_flags & IFF_NOARP) 827 goto out; 828 829 memcpy(&isaddr, ar_spa(ah), sizeof(isaddr)); 830 memcpy(&itaddr, ar_tpa(ah), sizeof(itaddr)); 831 832 if (m->m_flags & (M_BCAST|M_MCAST)) 833 ARP_STATINC(ARP_STAT_RCVMCAST); 834 835 /* 836 * Search for a matching interface address 837 * or any address on the interface to use 838 * as a dummy address in the rest of this function. 839 * 840 * First try and find the source address for early 841 * duplicate address detection. 842 */ 843 if (in_nullhost(isaddr)) { 844 if (in_nullhost(itaddr)) /* very bogus ARP */ 845 goto out; 846 find_source = false; 847 myaddr = itaddr; 848 } else { 849 find_source = true; 850 myaddr = isaddr; 851 } 852 s = pserialize_read_enter(); 853 again: 854 IN_ADDRHASH_READER_FOREACH(ia, myaddr.s_addr) { 855 if (!in_hosteq(ia->ia_addr.sin_addr, myaddr)) 856 continue; 857 #if NCARP > 0 858 if (ia->ia_ifp->if_type == IFT_CARP && 859 ((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) == 860 (IFF_UP|IFF_RUNNING))) { 861 index++; 862 /* XXX: ar_hln? */ 863 if (ia->ia_ifp == rcvif && (ah->ar_hln >= 6) && 864 carp_iamatch(ia, ar_sha(ah), 865 &count, index)) { 866 break; 867 } 868 } else 869 #endif 870 if (ia->ia_ifp == rcvif) 871 break; 872 #if NBRIDGE > 0 873 /* 874 * If the interface we received the packet on 875 * is part of a bridge, check to see if we need 876 * to "bridge" the packet to ourselves at this 877 * layer. Note we still prefer a perfect match, 878 * but allow this weaker match if necessary. 879 */ 880 if (rcvif->if_bridge != NULL && 881 rcvif->if_bridge == ia->ia_ifp->if_bridge) 882 bridge_ia = ia; 883 #endif 884 } 885 886 #if NBRIDGE > 0 887 if (ia == NULL && bridge_ia != NULL) { 888 ia = bridge_ia; 889 m_put_rcvif_psref(rcvif, &psref); 890 rcvif = NULL; 891 /* FIXME */ 892 ifp = bridge_ia->ia_ifp; 893 } 894 #endif 895 896 /* If we failed to find the source address then find 897 * the target address. */ 898 if (ia == NULL && find_source && !in_nullhost(itaddr)) { 899 find_source = false; 900 myaddr = itaddr; 901 goto again; 902 } 903 904 if (ia != NULL) 905 ia4_acquire(ia, &psref_ia); 906 pserialize_read_exit(s); 907 908 if (ah->ar_hln != ifp->if_addrlen) { 909 ARP_STATINC(ARP_STAT_RCVBADLEN); 910 log(LOG_WARNING, 911 "arp from %s: addr len: new %d, i/f %d (ignored)\n", 912 IN_PRINT(ipbuf, &isaddr), ah->ar_hln, ifp->if_addrlen); 913 goto out; 914 } 915 916 /* Only do DaD if we have a matching address. */ 917 do_dad = (ia != NULL); 918 919 if (ia == NULL) { 920 ia = in_get_ia_on_iface_psref(isaddr, rcvif, &psref_ia); 921 if (ia == NULL) { 922 ia = in_get_ia_from_ifp_psref(ifp, &psref_ia); 923 if (ia == NULL) { 924 ARP_STATINC(ARP_STAT_RCVNOINT); 925 goto out; 926 } 927 } 928 } 929 930 myaddr = ia->ia_addr.sin_addr; 931 932 /* XXX checks for bridge case? */ 933 if (!memcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 934 ARP_STATINC(ARP_STAT_RCVBCASTSHA); 935 log(LOG_ERR, 936 "%s: arp: link address is broadcast for IP address %s!\n", 937 ifp->if_xname, IN_PRINT(ipbuf, &isaddr)); 938 goto out; 939 } 940 941 /* 942 * If the source IP address is zero, this is an RFC 5227 ARP probe 943 */ 944 if (in_nullhost(isaddr)) 945 ARP_STATINC(ARP_STAT_RCVZEROSPA); 946 else if (in_hosteq(isaddr, myaddr)) 947 ARP_STATINC(ARP_STAT_RCVLOCALSPA); 948 949 if (in_nullhost(itaddr)) 950 ARP_STATINC(ARP_STAT_RCVZEROTPA); 951 952 /* 953 * DAD check, RFC 5227. 954 * Collision on sender address is always a duplicate. 955 * Collision on target address is only a duplicate 956 * IF the sender address is the null host (ie a DAD probe) 957 * AND the message was broadcast 958 * AND our address is either tentative or duplicated 959 * If it was unicast then it's a valid Unicast Poll from RFC 1122. 960 */ 961 if (do_dad && 962 (in_hosteq(isaddr, myaddr) || 963 (in_nullhost(isaddr) && in_hosteq(itaddr, myaddr) && 964 m->m_flags & M_BCAST && 965 ia->ia4_flags & (IN_IFF_TENTATIVE | IN_IFF_DUPLICATED)))) 966 { 967 struct sockaddr_dl sdl, *sdlp; 968 969 sdlp = sockaddr_dl_init(&sdl, sizeof(sdl), 970 ifp->if_index, ifp->if_type, 971 NULL, 0, ar_sha(ah), ah->ar_hln); 972 arp_dad_duplicated((struct ifaddr *)ia, sdlp); 973 goto out; 974 } 975 976 /* 977 * If the target IP address is zero, ignore the packet. 978 * This prevents the code below from trying to answer 979 * when we are using IP address zero (booting). 980 */ 981 if (in_nullhost(itaddr)) 982 goto out; 983 984 if (in_nullhost(isaddr)) 985 goto reply; 986 987 if (in_hosteq(itaddr, myaddr)) 988 la = arpcreate(ifp, &isaddr, NULL, 1); 989 else 990 la = arplookup(ifp, &isaddr, NULL, 1); 991 if (la == NULL) 992 goto reply; 993 994 if ((la->la_flags & LLE_VALID) && 995 memcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) 996 { 997 char llabuf[LLA_ADDRSTRLEN], *llastr; 998 999 llastr = lla_snprintf(llabuf, sizeof(llabuf), 1000 ar_sha(ah), ah->ar_hln); 1001 1002 if (la->la_flags & LLE_STATIC) { 1003 ARP_STATINC(ARP_STAT_RCVOVERPERM); 1004 if (!log_permanent_modify) 1005 goto out; 1006 log(LOG_INFO, 1007 "%s tried to overwrite permanent arp info" 1008 " for %s\n", llastr, IN_PRINT(ipbuf, &isaddr)); 1009 goto out; 1010 } else if (la->lle_tbl->llt_ifp != ifp) { 1011 /* XXX should not happen? */ 1012 ARP_STATINC(ARP_STAT_RCVOVERINT); 1013 if (!log_wrong_iface) 1014 goto out; 1015 log(LOG_INFO, 1016 "%s on %s tried to overwrite " 1017 "arp info for %s on %s\n", 1018 llastr, 1019 ifp->if_xname, IN_PRINT(ipbuf, &isaddr), 1020 la->lle_tbl->llt_ifp->if_xname); 1021 goto out; 1022 } else { 1023 ARP_STATINC(ARP_STAT_RCVOVER); 1024 if (log_movements) 1025 log(LOG_INFO, "arp info overwritten " 1026 "for %s by %s\n", 1027 IN_PRINT(ipbuf, &isaddr), llastr); 1028 } 1029 rt_cmd = RTM_CHANGE; 1030 new_state = ND_LLINFO_STALE; 1031 } else { 1032 if (op == ARPOP_REPLY && in_hosteq(itaddr, myaddr)) { 1033 /* This was a solicited ARP reply. */ 1034 la->ln_byhint = 0; 1035 new_state = ND_LLINFO_REACHABLE; 1036 } 1037 rt_cmd = la->la_flags & LLE_VALID ? 0 : RTM_ADD; 1038 } 1039 1040 KASSERT(ifp->if_sadl->sdl_alen == ifp->if_addrlen); 1041 1042 KASSERT(sizeof(la->ll_addr) >= ifp->if_addrlen); 1043 memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen); 1044 la->la_flags |= LLE_VALID; 1045 la->ln_asked = 0; 1046 if (new_state != 0) { 1047 la->ln_state = new_state; 1048 1049 if (new_state != ND_LLINFO_REACHABLE || 1050 !(la->la_flags & LLE_STATIC)) 1051 { 1052 int timer = ND_TIMER_GC; 1053 1054 if (new_state == ND_LLINFO_REACHABLE) 1055 timer = ND_TIMER_REACHABLE; 1056 nd_set_timer(la, timer); 1057 } 1058 } 1059 1060 if (rt_cmd != 0) { 1061 struct sockaddr_in sin; 1062 1063 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 1064 rt_clonedmsg(rt_cmd, NULL, sintosa(&sin), ar_sha(ah), ifp); 1065 } 1066 1067 if (la->la_hold != NULL) { 1068 int n = la->la_numheld; 1069 struct mbuf *m_hold, *m_hold_next; 1070 struct sockaddr_in sin; 1071 1072 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 1073 1074 m_hold = la->la_hold; 1075 la->la_hold = NULL; 1076 la->la_numheld = 0; 1077 /* 1078 * We have to unlock here because if_output would call 1079 * arpresolve 1080 */ 1081 LLE_WUNLOCK(la); 1082 ARP_STATADD(ARP_STAT_DFRSENT, n); 1083 ARP_STATADD(ARP_STAT_DFRTOTAL, n); 1084 for (; m_hold != NULL; m_hold = m_hold_next) { 1085 m_hold_next = m_hold->m_nextpkt; 1086 m_hold->m_nextpkt = NULL; 1087 if_output_lock(ifp, ifp, m_hold, sintosa(&sin), NULL); 1088 } 1089 } else 1090 LLE_WUNLOCK(la); 1091 la = NULL; 1092 1093 reply: 1094 if (la != NULL) { 1095 LLE_WUNLOCK(la); 1096 la = NULL; 1097 } 1098 if (op != ARPOP_REQUEST) { 1099 if (op == ARPOP_REPLY) 1100 ARP_STATINC(ARP_STAT_RCVREPLY); 1101 goto out; 1102 } 1103 ARP_STATINC(ARP_STAT_RCVREQUEST); 1104 if (in_hosteq(itaddr, myaddr)) { 1105 /* If our address is unusable, don't reply */ 1106 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) 1107 goto out; 1108 /* I am the target */ 1109 tha = ar_tha(ah); 1110 if (tha) 1111 memcpy(tha, ar_sha(ah), ah->ar_hln); 1112 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1113 } else { 1114 /* Proxy ARP */ 1115 struct llentry *lle = NULL; 1116 struct sockaddr_in sin; 1117 1118 #if NCARP > 0 1119 if (ifp->if_type == IFT_CARP) { 1120 struct ifnet *_rcvif = m_get_rcvif(m, &s); 1121 int iftype = 0; 1122 if (__predict_true(_rcvif != NULL)) 1123 iftype = _rcvif->if_type; 1124 m_put_rcvif(_rcvif, &s); 1125 if (iftype != IFT_CARP) 1126 goto out; 1127 } 1128 #endif 1129 1130 tha = ar_tha(ah); 1131 1132 sockaddr_in_init(&sin, &itaddr, 0); 1133 1134 IF_AFDATA_RLOCK(ifp); 1135 lle = lla_lookup(LLTABLE(ifp), 0, (struct sockaddr *)&sin); 1136 IF_AFDATA_RUNLOCK(ifp); 1137 1138 if ((lle != NULL) && (lle->la_flags & LLE_PUB)) { 1139 if (tha) 1140 memcpy(tha, ar_sha(ah), ah->ar_hln); 1141 memcpy(ar_sha(ah), &lle->ll_addr, ah->ar_hln); 1142 LLE_RUNLOCK(lle); 1143 } else { 1144 if (lle != NULL) 1145 LLE_RUNLOCK(lle); 1146 goto out; 1147 } 1148 } 1149 ia4_release(ia, &psref_ia); 1150 1151 /* 1152 * XXX XXX: Here we're recycling the mbuf. But the mbuf could have 1153 * other mbufs in its chain, and just overwriting m->m_pkthdr.len 1154 * would be wrong in this case (the length becomes smaller than the 1155 * real chain size). 1156 * 1157 * This can theoretically cause bugs in the lower layers (drivers, 1158 * and L2encap), in some corner cases. 1159 */ 1160 memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); 1161 memcpy(ar_spa(ah), &itaddr, ah->ar_pln); 1162 ah->ar_op = htons(ARPOP_REPLY); 1163 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 1164 switch (ifp->if_type) { 1165 case IFT_IEEE1394: 1166 /* ieee1394 arp reply is broadcast */ 1167 m->m_flags &= ~M_MCAST; 1168 m->m_flags |= M_BCAST; 1169 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + ah->ar_hln; 1170 break; 1171 default: 1172 m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */ 1173 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); 1174 break; 1175 } 1176 m->m_pkthdr.len = m->m_len; 1177 sa.sa_family = AF_ARP; 1178 sa.sa_len = 2; 1179 arps = ARP_STAT_GETREF(); 1180 arps[ARP_STAT_SNDTOTAL]++; 1181 arps[ARP_STAT_SNDREPLY]++; 1182 ARP_STAT_PUTREF(); 1183 if_output_lock(ifp, ifp, m, &sa, NULL); 1184 if (rcvif != NULL) 1185 m_put_rcvif_psref(rcvif, &psref); 1186 return; 1187 1188 out: 1189 if (la != NULL) 1190 LLE_WUNLOCK(la); 1191 if (ia != NULL) 1192 ia4_release(ia, &psref_ia); 1193 if (rcvif != NULL) 1194 m_put_rcvif_psref(rcvif, &psref); 1195 m_freem(m); 1196 } 1197 1198 /* 1199 * Lookup or a new address in arptab. 1200 */ 1201 struct llentry * 1202 arplookup(struct ifnet *ifp, const struct in_addr *addr, 1203 const struct sockaddr *sa, int wlock) 1204 { 1205 struct sockaddr_in sin; 1206 struct llentry *la; 1207 int flags = wlock ? LLE_EXCLUSIVE : 0; 1208 1209 if (sa == NULL) { 1210 KASSERT(addr != NULL); 1211 sockaddr_in_init(&sin, addr, 0); 1212 sa = sintocsa(&sin); 1213 } 1214 1215 IF_AFDATA_RLOCK(ifp); 1216 la = lla_lookup(LLTABLE(ifp), flags, sa); 1217 IF_AFDATA_RUNLOCK(ifp); 1218 1219 return la; 1220 } 1221 1222 static struct llentry * 1223 arpcreate(struct ifnet *ifp, const struct in_addr *addr, 1224 const struct sockaddr *sa, int wlock) 1225 { 1226 struct sockaddr_in sin; 1227 struct llentry *la; 1228 int flags = wlock ? LLE_EXCLUSIVE : 0; 1229 1230 if (sa == NULL) { 1231 KASSERT(addr != NULL); 1232 sockaddr_in_init(&sin, addr, 0); 1233 sa = sintocsa(&sin); 1234 } 1235 1236 la = arplookup(ifp, addr, sa, wlock); 1237 1238 if (la == NULL) { 1239 struct rtentry *rt; 1240 1241 rt = rtalloc1(sa, 0); 1242 IF_AFDATA_WLOCK(ifp); 1243 la = lla_create(LLTABLE(ifp), flags, sa, rt); 1244 IF_AFDATA_WUNLOCK(ifp); 1245 if (rt != NULL) 1246 rt_unref(rt); 1247 1248 if (la != NULL) 1249 la->ln_state = ND_LLINFO_NOSTATE; 1250 } 1251 1252 return la; 1253 } 1254 1255 int 1256 arpioctl(u_long cmd, void *data) 1257 { 1258 1259 return EOPNOTSUPP; 1260 } 1261 1262 void 1263 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1264 { 1265 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1266 1267 ifa->ifa_rtrequest = arp_rtrequest; 1268 ifa->ifa_flags |= RTF_CONNECTED; 1269 1270 /* ARP will handle DAD for this address. */ 1271 if (in_nullhost(IA_SIN(ifa)->sin_addr)) { 1272 if (ia->ia_dad_stop != NULL) /* safety */ 1273 ia->ia_dad_stop(ifa); 1274 ia->ia_dad_start = NULL; 1275 ia->ia_dad_stop = NULL; 1276 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1277 } else { 1278 ia->ia_dad_start = arp_dad_start; 1279 ia->ia_dad_stop = arp_dad_stop; 1280 if (ia->ia4_flags & IN_IFF_TRYTENTATIVE && ip_dad_enabled()) 1281 ia->ia4_flags |= IN_IFF_TENTATIVE; 1282 else 1283 arpannounce1(ifa); 1284 } 1285 } 1286 1287 static bool 1288 arp_nud_enabled(__unused struct ifnet *ifp) 1289 { 1290 1291 return arp_perform_nud != 0; 1292 } 1293 1294 static unsigned int 1295 arp_llinfo_reachable(__unused struct ifnet *ifp) 1296 { 1297 1298 return arp_reachable; 1299 } 1300 1301 static unsigned int 1302 arp_llinfo_retrans(__unused struct ifnet *ifp) 1303 { 1304 1305 return arp_retrans; 1306 } 1307 1308 /* 1309 * Gets source address of the first packet in hold queue 1310 * and stores it in @src. 1311 * Returns pointer to @src (if hold queue is not empty) or NULL. 1312 */ 1313 static union l3addr * 1314 arp_llinfo_holdsrc(struct llentry *ln, union l3addr *src) 1315 { 1316 struct ip *ip; 1317 1318 if (ln == NULL || ln->ln_hold == NULL) 1319 return NULL; 1320 1321 /* 1322 * assuming every packet in ln_hold has the same IP header 1323 */ 1324 ip = mtod(ln->ln_hold, struct ip *); 1325 /* XXX pullup? */ 1326 if (sizeof(*ip) < ln->ln_hold->m_len) 1327 src->addr4 = ip->ip_src; 1328 else 1329 src = NULL; 1330 1331 return src; 1332 } 1333 1334 static void 1335 arp_llinfo_output(struct ifnet *ifp, __unused const union l3addr *daddr, 1336 const union l3addr *taddr, const uint8_t *tlladdr, 1337 const union l3addr *hsrc) 1338 { 1339 struct in_addr tip = taddr->addr4, sip = zeroin_addr; 1340 const uint8_t *slladdr = CLLADDR(ifp->if_sadl); 1341 1342 if (hsrc != NULL) { 1343 struct in_ifaddr *ia; 1344 struct psref psref; 1345 1346 ia = in_get_ia_on_iface_psref(hsrc->addr4, ifp, &psref); 1347 if (ia != NULL) { 1348 sip = hsrc->addr4; 1349 ia4_release(ia, &psref); 1350 } 1351 } 1352 1353 if (sip.s_addr == INADDR_ANY) { 1354 struct sockaddr_in dst; 1355 struct rtentry *rt; 1356 1357 sockaddr_in_init(&dst, &tip, 0); 1358 rt = rtalloc1(sintosa(&dst), 0); 1359 if (rt != NULL) { 1360 if (rt->rt_ifp == ifp && 1361 rt->rt_ifa != NULL && 1362 rt->rt_ifa->ifa_addr->sa_family == AF_INET) 1363 sip = satosin(rt->rt_ifa->ifa_addr)->sin_addr; 1364 rt_unref(rt); 1365 } 1366 if (sip.s_addr == INADDR_ANY) { 1367 char ipbuf[INET_ADDRSTRLEN]; 1368 1369 log(LOG_DEBUG, "source can't be " 1370 "determined: dst=%s\n", 1371 IN_PRINT(ipbuf, &tip)); 1372 return; 1373 } 1374 } 1375 1376 arprequest(ifp, &sip, &tip, slladdr, tlladdr); 1377 } 1378 1379 1380 static void 1381 arp_llinfo_missed(struct ifnet *ifp, const union l3addr *taddr, 1382 __unused int16_t type, struct mbuf *m) 1383 { 1384 struct in_addr mdaddr = zeroin_addr; 1385 struct sockaddr_in dsin, tsin; 1386 struct sockaddr *sa; 1387 1388 if (m != NULL) { 1389 struct ip *ip = mtod(m, struct ip *); 1390 1391 if (sizeof(*ip) < m->m_len) 1392 mdaddr = ip->ip_src; 1393 1394 /* ip_input() will send ICMP_UNREACH_HOST, not us. */ 1395 m_freem(m); 1396 } 1397 1398 if (mdaddr.s_addr != INADDR_ANY) { 1399 sockaddr_in_init(&dsin, &mdaddr, 0); 1400 sa = sintosa(&dsin); 1401 } else 1402 sa = NULL; 1403 1404 sockaddr_in_init(&tsin, &taddr->addr4, 0); 1405 rt_clonedmsg(RTM_MISS, sa, sintosa(&tsin), NULL, ifp); 1406 } 1407 1408 static void 1409 arp_free(struct llentry *ln, int gc) 1410 { 1411 struct ifnet *ifp; 1412 1413 KASSERT(ln != NULL); 1414 LLE_WLOCK_ASSERT(ln); 1415 1416 ifp = ln->lle_tbl->llt_ifp; 1417 1418 if (ln->la_flags & LLE_VALID || gc) { 1419 struct sockaddr_in sin; 1420 const char *lladdr; 1421 1422 sockaddr_in_init(&sin, &ln->r_l3addr.addr4, 0); 1423 lladdr = ln->la_flags & LLE_VALID ? 1424 (const char *)&ln->ll_addr : NULL; 1425 rt_clonedmsg(RTM_DELETE, NULL, sintosa(&sin), lladdr, ifp); 1426 } 1427 1428 /* 1429 * Save to unlock. We still hold an extra reference and will not 1430 * free(9) in llentry_free() if someone else holds one as well. 1431 */ 1432 LLE_WUNLOCK(ln); 1433 IF_AFDATA_LOCK(ifp); 1434 LLE_WLOCK(ln); 1435 1436 lltable_free_entry(LLTABLE(ifp), ln); 1437 1438 IF_AFDATA_UNLOCK(ifp); 1439 } 1440 1441 /* 1442 * Upper-layer reachability hint for Neighbor Unreachability Detection. 1443 * 1444 * XXX cost-effective methods? 1445 */ 1446 void 1447 arp_nud_hint(struct rtentry *rt) 1448 { 1449 struct llentry *ln; 1450 struct ifnet *ifp; 1451 1452 if (rt == NULL) 1453 return; 1454 1455 ifp = rt->rt_ifp; 1456 ln = arplookup(ifp, NULL, rt_getkey(rt), 1); 1457 nd_nud_hint(ln); 1458 } 1459 1460 TAILQ_HEAD(dadq_head, dadq); 1461 struct dadq { 1462 TAILQ_ENTRY(dadq) dad_list; 1463 struct ifaddr *dad_ifa; 1464 int dad_count; /* max ARP to send */ 1465 int dad_arp_tcount; /* # of trials to send ARP */ 1466 int dad_arp_ocount; /* ARP sent so far */ 1467 int dad_arp_announce; /* max ARP announcements */ 1468 int dad_arp_acount; /* # of announcements */ 1469 struct callout dad_timer_ch; 1470 }; 1471 1472 static struct dadq_head dadq; 1473 static int dad_maxtry = 15; /* max # of *tries* to transmit DAD packet */ 1474 static kmutex_t arp_dad_lock; 1475 1476 static void 1477 arp_dad_init(void) 1478 { 1479 1480 TAILQ_INIT(&dadq); 1481 mutex_init(&arp_dad_lock, MUTEX_DEFAULT, IPL_NONE); 1482 } 1483 1484 static struct dadq * 1485 arp_dad_find(struct ifaddr *ifa) 1486 { 1487 struct dadq *dp; 1488 1489 KASSERT(mutex_owned(&arp_dad_lock)); 1490 1491 TAILQ_FOREACH(dp, &dadq, dad_list) { 1492 if (dp->dad_ifa == ifa) 1493 return dp; 1494 } 1495 return NULL; 1496 } 1497 1498 static void 1499 arp_dad_starttimer(struct dadq *dp, int ticks) 1500 { 1501 1502 callout_reset(&dp->dad_timer_ch, ticks, 1503 (void (*)(void *))arp_dad_timer, dp); 1504 } 1505 1506 static void 1507 arp_dad_stoptimer(struct dadq *dp) 1508 { 1509 1510 KASSERT(mutex_owned(&arp_dad_lock)); 1511 1512 TAILQ_REMOVE(&dadq, dp, dad_list); 1513 /* Tell the timer that dp is being destroyed. */ 1514 dp->dad_ifa = NULL; 1515 callout_halt(&dp->dad_timer_ch, &arp_dad_lock); 1516 } 1517 1518 static void 1519 arp_dad_destroytimer(struct dadq *dp) 1520 { 1521 1522 callout_destroy(&dp->dad_timer_ch); 1523 KASSERT(dp->dad_ifa == NULL); 1524 kmem_intr_free(dp, sizeof(*dp)); 1525 } 1526 1527 static void 1528 arp_dad_output(struct dadq *dp, struct ifaddr *ifa) 1529 { 1530 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1531 struct ifnet *ifp = ifa->ifa_ifp; 1532 struct in_addr sip; 1533 1534 dp->dad_arp_tcount++; 1535 if ((ifp->if_flags & IFF_UP) == 0) 1536 return; 1537 if ((ifp->if_flags & IFF_RUNNING) == 0) 1538 return; 1539 1540 dp->dad_arp_tcount = 0; 1541 dp->dad_arp_ocount++; 1542 1543 memset(&sip, 0, sizeof(sip)); 1544 arprequest(ifa->ifa_ifp, &sip, &ia->ia_addr.sin_addr, 1545 CLLADDR(ifa->ifa_ifp->if_sadl), NULL); 1546 } 1547 1548 /* 1549 * Start Duplicate Address Detection (DAD) for specified interface address. 1550 */ 1551 static void 1552 arp_dad_start(struct ifaddr *ifa) 1553 { 1554 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1555 struct dadq *dp; 1556 char ipbuf[INET_ADDRSTRLEN]; 1557 1558 /* 1559 * If we don't need DAD, don't do it. 1560 * - DAD is disabled 1561 */ 1562 if (!(ia->ia4_flags & IN_IFF_TENTATIVE)) { 1563 log(LOG_DEBUG, 1564 "%s: called with non-tentative address %s(%s)\n", __func__, 1565 IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1566 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1567 return; 1568 } 1569 if (!ip_dad_enabled()) { 1570 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1571 rt_addrmsg(RTM_NEWADDR, ifa); 1572 arpannounce1(ifa); 1573 return; 1574 } 1575 KASSERT(ifa->ifa_ifp != NULL); 1576 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) 1577 return; 1578 1579 dp = kmem_intr_alloc(sizeof(*dp), KM_NOSLEEP); 1580 1581 mutex_enter(&arp_dad_lock); 1582 if (arp_dad_find(ifa) != NULL) { 1583 mutex_exit(&arp_dad_lock); 1584 /* DAD already in progress */ 1585 if (dp != NULL) 1586 kmem_intr_free(dp, sizeof(*dp)); 1587 return; 1588 } 1589 1590 if (dp == NULL) { 1591 mutex_exit(&arp_dad_lock); 1592 log(LOG_ERR, "%s: memory allocation failed for %s(%s)\n", 1593 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1594 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1595 return; 1596 } 1597 1598 /* 1599 * Send ARP packet for DAD, ip_dad_count times. 1600 * Note that we must delay the first transmission. 1601 */ 1602 callout_init(&dp->dad_timer_ch, CALLOUT_MPSAFE); 1603 dp->dad_ifa = ifa; 1604 ifaref(ifa); /* just for safety */ 1605 dp->dad_count = ip_dad_count; 1606 dp->dad_arp_announce = 0; /* Will be set when starting to announce */ 1607 dp->dad_arp_acount = dp->dad_arp_ocount = dp->dad_arp_tcount = 0; 1608 TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list); 1609 1610 ARPLOG(LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1611 ARPLOGADDR(&ia->ia_addr.sin_addr)); 1612 1613 arp_dad_starttimer(dp, cprng_fast32() % (PROBE_WAIT * hz)); 1614 1615 mutex_exit(&arp_dad_lock); 1616 } 1617 1618 /* 1619 * terminate DAD unconditionally. used for address removals. 1620 */ 1621 static void 1622 arp_dad_stop(struct ifaddr *ifa) 1623 { 1624 struct dadq *dp; 1625 1626 mutex_enter(&arp_dad_lock); 1627 dp = arp_dad_find(ifa); 1628 if (dp == NULL) { 1629 mutex_exit(&arp_dad_lock); 1630 /* DAD wasn't started yet */ 1631 return; 1632 } 1633 1634 arp_dad_stoptimer(dp); 1635 1636 mutex_exit(&arp_dad_lock); 1637 1638 arp_dad_destroytimer(dp); 1639 ifafree(ifa); 1640 } 1641 1642 static void 1643 arp_dad_timer(struct dadq *dp) 1644 { 1645 struct ifaddr *ifa; 1646 struct in_ifaddr *ia; 1647 char ipbuf[INET_ADDRSTRLEN]; 1648 bool need_free = false; 1649 1650 KERNEL_LOCK_UNLESS_NET_MPSAFE(); 1651 mutex_enter(&arp_dad_lock); 1652 1653 ifa = dp->dad_ifa; 1654 if (ifa == NULL) { 1655 /* dp is being destroyed by someone. Do nothing. */ 1656 goto done; 1657 } 1658 1659 ia = (struct in_ifaddr *)ifa; 1660 if (ia->ia4_flags & IN_IFF_DUPLICATED) { 1661 log(LOG_ERR, "%s: called with duplicate address %s(%s)\n", 1662 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1663 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1664 goto done; 1665 } 1666 if ((ia->ia4_flags & IN_IFF_TENTATIVE) == 0 && dp->dad_arp_acount == 0) 1667 { 1668 log(LOG_ERR, "%s: called with non-tentative address %s(%s)\n", 1669 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1670 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1671 goto done; 1672 } 1673 1674 /* timeouted with IFF_{RUNNING,UP} check */ 1675 if (dp->dad_arp_tcount > dad_maxtry) { 1676 ARPLOG(LOG_INFO, "%s: could not run DAD, driver problem?\n", 1677 if_name(ifa->ifa_ifp)); 1678 1679 arp_dad_stoptimer(dp); 1680 need_free = true; 1681 goto done; 1682 } 1683 1684 /* Need more checks? */ 1685 if (dp->dad_arp_ocount < dp->dad_count) { 1686 int adelay; 1687 1688 /* 1689 * We have more ARP to go. Send ARP packet for DAD. 1690 */ 1691 arp_dad_output(dp, ifa); 1692 if (dp->dad_arp_ocount < dp->dad_count) 1693 adelay = (PROBE_MIN * hz) + 1694 (cprng_fast32() % 1695 ((PROBE_MAX * hz) - (PROBE_MIN * hz))); 1696 else 1697 adelay = ANNOUNCE_WAIT * hz; 1698 arp_dad_starttimer(dp, adelay); 1699 goto done; 1700 } else if (dp->dad_arp_acount == 0) { 1701 /* 1702 * We are done with DAD. 1703 * No duplicate address found. 1704 */ 1705 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1706 rt_addrmsg(RTM_NEWADDR, ifa); 1707 ARPLOG(LOG_DEBUG, 1708 "%s: DAD complete for %s - no duplicates found\n", 1709 if_name(ifa->ifa_ifp), ARPLOGADDR(&ia->ia_addr.sin_addr)); 1710 dp->dad_arp_announce = ANNOUNCE_NUM; 1711 goto announce; 1712 } else if (dp->dad_arp_acount < dp->dad_arp_announce) { 1713 announce: 1714 /* 1715 * Announce the address. 1716 */ 1717 arpannounce1(ifa); 1718 dp->dad_arp_acount++; 1719 if (dp->dad_arp_acount < dp->dad_arp_announce) { 1720 arp_dad_starttimer(dp, ANNOUNCE_INTERVAL * hz); 1721 goto done; 1722 } 1723 ARPLOG(LOG_DEBUG, 1724 "%s: ARP announcement complete for %s\n", 1725 if_name(ifa->ifa_ifp), ARPLOGADDR(&ia->ia_addr.sin_addr)); 1726 } 1727 1728 arp_dad_stoptimer(dp); 1729 need_free = true; 1730 done: 1731 mutex_exit(&arp_dad_lock); 1732 1733 if (need_free) { 1734 arp_dad_destroytimer(dp); 1735 KASSERT(ifa != NULL); 1736 ifafree(ifa); 1737 } 1738 1739 KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 1740 } 1741 1742 static void 1743 arp_dad_duplicated(struct ifaddr *ifa, const struct sockaddr_dl *from) 1744 { 1745 struct in_ifaddr *ia = ifatoia(ifa); 1746 struct ifnet *ifp = ifa->ifa_ifp; 1747 char ipbuf[INET_ADDRSTRLEN], llabuf[LLA_ADDRSTRLEN]; 1748 const char *iastr, *llastr; 1749 1750 iastr = IN_PRINT(ipbuf, &ia->ia_addr.sin_addr); 1751 if (__predict_false(from == NULL)) 1752 llastr = NULL; 1753 else 1754 llastr = lla_snprintf(llabuf, sizeof(llabuf), 1755 CLLADDR(from), from->sdl_alen); 1756 1757 if (ia->ia4_flags & (IN_IFF_TENTATIVE|IN_IFF_DUPLICATED)) { 1758 log(LOG_ERR, 1759 "%s: DAD duplicate address %s from %s\n", 1760 if_name(ifp), iastr, llastr); 1761 } else if (ia->ia_dad_defended == 0 || 1762 ia->ia_dad_defended < time_uptime - DEFEND_INTERVAL) { 1763 ia->ia_dad_defended = time_uptime; 1764 arpannounce1(ifa); 1765 log(LOG_ERR, 1766 "%s: DAD defended address %s from %s\n", 1767 if_name(ifp), iastr, llastr); 1768 return; 1769 } else { 1770 /* If DAD is disabled, just report the duplicate. */ 1771 if (!ip_dad_enabled()) { 1772 log(LOG_ERR, 1773 "%s: DAD ignoring duplicate address %s from %s\n", 1774 if_name(ifp), iastr, llastr); 1775 return; 1776 } 1777 log(LOG_ERR, 1778 "%s: DAD defence failed for %s from %s\n", 1779 if_name(ifp), iastr, llastr); 1780 } 1781 1782 arp_dad_stop(ifa); 1783 1784 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1785 if ((ia->ia4_flags & IN_IFF_DUPLICATED) == 0) { 1786 ia->ia4_flags |= IN_IFF_DUPLICATED; 1787 /* Inform the routing socket of the duplicate address */ 1788 rt_addrmsg_src(RTM_NEWADDR, ifa, (const struct sockaddr *)from); 1789 } 1790 } 1791 1792 /* 1793 * Called from 10 Mb/s Ethernet interrupt handlers 1794 * when ether packet type ETHERTYPE_REVARP 1795 * is received. Common length and type checks are done here, 1796 * then the protocol-specific routine is called. 1797 */ 1798 void 1799 revarpinput(struct mbuf *m) 1800 { 1801 struct arphdr *ar; 1802 int arplen; 1803 1804 arplen = sizeof(struct arphdr); 1805 if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL) 1806 return; 1807 ar = mtod(m, struct arphdr *); 1808 1809 if (ntohs(ar->ar_hrd) == ARPHRD_IEEE1394) { 1810 goto out; 1811 } 1812 1813 arplen = sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln); 1814 if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL) 1815 return; 1816 ar = mtod(m, struct arphdr *); 1817 1818 switch (ntohs(ar->ar_pro)) { 1819 case ETHERTYPE_IP: 1820 case ETHERTYPE_IPTRAILERS: 1821 in_revarpinput(m); 1822 return; 1823 1824 default: 1825 break; 1826 } 1827 1828 out: 1829 m_freem(m); 1830 } 1831 1832 /* 1833 * RARP for Internet protocols on 10 Mb/s Ethernet. 1834 * Algorithm is that given in RFC 903. 1835 * We are only using for bootstrap purposes to get an ip address for one of 1836 * our interfaces. Thus we support no user-interface. 1837 * 1838 * Since the contents of the RARP reply are specific to the interface that 1839 * sent the request, this code must ensure that they are properly associated. 1840 * 1841 * Note: also supports ARP via RARP packets, per the RFC. 1842 */ 1843 void 1844 in_revarpinput(struct mbuf *m) 1845 { 1846 struct arphdr *ah; 1847 void *tha; 1848 int op; 1849 struct ifnet *rcvif; 1850 int s; 1851 1852 ah = mtod(m, struct arphdr *); 1853 op = ntohs(ah->ar_op); 1854 1855 rcvif = m_get_rcvif(m, &s); 1856 if (__predict_false(rcvif == NULL)) 1857 goto out; 1858 if (rcvif->if_flags & IFF_NOARP) 1859 goto out; 1860 1861 switch (rcvif->if_type) { 1862 case IFT_IEEE1394: 1863 /* ARP without target hardware address is not supported */ 1864 goto out; 1865 default: 1866 break; 1867 } 1868 1869 switch (op) { 1870 case ARPOP_REQUEST: 1871 case ARPOP_REPLY: /* per RFC */ 1872 m_put_rcvif(rcvif, &s); 1873 in_arpinput(m); 1874 return; 1875 case ARPOP_REVREPLY: 1876 break; 1877 case ARPOP_REVREQUEST: /* handled by rarpd(8) */ 1878 default: 1879 goto out; 1880 } 1881 if (!revarp_in_progress) 1882 goto out; 1883 if (rcvif != myip_ifp) /* !same interface */ 1884 goto out; 1885 if (myip_initialized) 1886 goto wake; 1887 tha = ar_tha(ah); 1888 if (tha == NULL) 1889 goto out; 1890 if (ah->ar_pln != sizeof(struct in_addr)) 1891 goto out; 1892 if (ah->ar_hln != rcvif->if_sadl->sdl_alen) 1893 goto out; 1894 if (memcmp(tha, CLLADDR(rcvif->if_sadl), rcvif->if_sadl->sdl_alen)) 1895 goto out; 1896 memcpy(&srv_ip, ar_spa(ah), sizeof(srv_ip)); 1897 memcpy(&myip, ar_tpa(ah), sizeof(myip)); 1898 myip_initialized = 1; 1899 wake: /* Do wakeup every time in case it was missed. */ 1900 wakeup((void *)&myip); 1901 1902 out: 1903 m_put_rcvif(rcvif, &s); 1904 m_freem(m); 1905 } 1906 1907 /* 1908 * Send a RARP request for the ip address of the specified interface. 1909 * The request should be RFC 903-compliant. 1910 */ 1911 static void 1912 revarprequest(struct ifnet *ifp) 1913 { 1914 struct sockaddr sa; 1915 struct mbuf *m; 1916 struct arphdr *ah; 1917 void *tha; 1918 1919 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 1920 return; 1921 MCLAIM(m, &arpdomain.dom_mowner); 1922 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) + 1923 2*ifp->if_addrlen; 1924 m->m_pkthdr.len = m->m_len; 1925 m_align(m, m->m_len); 1926 ah = mtod(m, struct arphdr *); 1927 memset(ah, 0, m->m_len); 1928 ah->ar_pro = htons(ETHERTYPE_IP); 1929 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 1930 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 1931 ah->ar_op = htons(ARPOP_REVREQUEST); 1932 1933 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1934 tha = ar_tha(ah); 1935 if (tha == NULL) { 1936 m_free(m); 1937 return; 1938 } 1939 memcpy(tha, CLLADDR(ifp->if_sadl), ah->ar_hln); 1940 1941 sa.sa_family = AF_ARP; 1942 sa.sa_len = 2; 1943 m->m_flags |= M_BCAST; 1944 1945 if_output_lock(ifp, ifp, m, &sa, NULL); 1946 } 1947 1948 /* 1949 * RARP for the ip address of the specified interface, but also 1950 * save the ip address of the server that sent the answer. 1951 * Timeout if no response is received. 1952 */ 1953 int 1954 revarpwhoarewe(struct ifnet *ifp, struct in_addr *serv_in, 1955 struct in_addr *clnt_in) 1956 { 1957 int result, count = 20; 1958 1959 myip_initialized = 0; 1960 myip_ifp = ifp; 1961 1962 revarp_in_progress = 1; 1963 while (count--) { 1964 revarprequest(ifp); 1965 result = tsleep((void *)&myip, PSOCK, "revarp", hz/2); 1966 if (result != EWOULDBLOCK) 1967 break; 1968 } 1969 revarp_in_progress = 0; 1970 1971 if (!myip_initialized) 1972 return ENETUNREACH; 1973 1974 memcpy(serv_in, &srv_ip, sizeof(*serv_in)); 1975 memcpy(clnt_in, &myip, sizeof(*clnt_in)); 1976 return 0; 1977 } 1978 1979 void 1980 arp_stat_add(int type, uint64_t count) 1981 { 1982 ARP_STATADD(type, count); 1983 } 1984 1985 static int 1986 sysctl_net_inet_arp_stats(SYSCTLFN_ARGS) 1987 { 1988 1989 return NETSTAT_SYSCTL(arpstat_percpu, ARP_NSTATS); 1990 } 1991 1992 static void 1993 sysctl_net_inet_arp_setup(struct sysctllog **clog) 1994 { 1995 const struct sysctlnode *node; 1996 1997 sysctl_createv(clog, 0, NULL, NULL, 1998 CTLFLAG_PERMANENT, 1999 CTLTYPE_NODE, "inet", NULL, 2000 NULL, 0, NULL, 0, 2001 CTL_NET, PF_INET, CTL_EOL); 2002 sysctl_createv(clog, 0, NULL, &node, 2003 CTLFLAG_PERMANENT, 2004 CTLTYPE_NODE, "arp", 2005 SYSCTL_DESCR("Address Resolution Protocol"), 2006 NULL, 0, NULL, 0, 2007 CTL_NET, PF_INET, CTL_CREATE, CTL_EOL); 2008 2009 sysctl_createv(clog, 0, NULL, NULL, 2010 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2011 CTLTYPE_INT, "nd_delay", 2012 SYSCTL_DESCR("First probe delay time"), 2013 NULL, 0, &arp_nd_domain.nd_delay, 0, 2014 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2015 sysctl_createv(clog, 0, NULL, NULL, 2016 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2017 CTLTYPE_INT, "nd_bmaxtries", 2018 SYSCTL_DESCR("Number of broadcast discovery attempts"), 2019 NULL, 0, &arp_nd_domain.nd_mmaxtries, 0, 2020 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2021 sysctl_createv(clog, 0, NULL, NULL, 2022 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2023 CTLTYPE_INT, "nd_umaxtries", 2024 SYSCTL_DESCR("Number of unicast discovery attempts"), 2025 NULL, 0, &arp_nd_domain.nd_umaxtries, 0, 2026 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2027 sysctl_createv(clog, 0, NULL, NULL, 2028 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2029 CTLTYPE_INT, "nd_reachable", 2030 SYSCTL_DESCR("Reachable time"), 2031 NULL, 0, &arp_reachable, 0, 2032 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2033 sysctl_createv(clog, 0, NULL, NULL, 2034 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2035 CTLTYPE_INT, "nd_retrans", 2036 SYSCTL_DESCR("Retransmission time"), 2037 NULL, 0, &arp_retrans, 0, 2038 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2039 sysctl_createv(clog, 0, NULL, NULL, 2040 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2041 CTLTYPE_INT, "nd_nud", 2042 SYSCTL_DESCR("Perform neighbour unreachability detection"), 2043 NULL, 0, &arp_perform_nud, 0, 2044 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2045 sysctl_createv(clog, 0, NULL, NULL, 2046 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2047 CTLTYPE_INT, "nd_maxnudhint", 2048 SYSCTL_DESCR("Maximum neighbor unreachable hint count"), 2049 NULL, 0, &arp_nd_domain.nd_maxnudhint, 0, 2050 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2051 sysctl_createv(clog, 0, NULL, NULL, 2052 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2053 CTLTYPE_INT, "maxqueuelen", 2054 SYSCTL_DESCR("max packet queue len for a unresolved ARP"), 2055 NULL, 1, &arp_nd_domain.nd_maxqueuelen, 0, 2056 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2057 2058 sysctl_createv(clog, 0, NULL, NULL, 2059 CTLFLAG_PERMANENT, 2060 CTLTYPE_STRUCT, "stats", 2061 SYSCTL_DESCR("ARP statistics"), 2062 sysctl_net_inet_arp_stats, 0, NULL, 0, 2063 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2064 2065 sysctl_createv(clog, 0, NULL, NULL, 2066 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2067 CTLTYPE_INT, "log_movements", 2068 SYSCTL_DESCR("log ARP replies from MACs different than" 2069 " the one in the cache"), 2070 NULL, 0, &log_movements, 0, 2071 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2072 2073 sysctl_createv(clog, 0, NULL, NULL, 2074 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2075 CTLTYPE_INT, "log_permanent_modify", 2076 SYSCTL_DESCR("log ARP replies from MACs different than" 2077 " the one in the permanent arp entry"), 2078 NULL, 0, &log_permanent_modify, 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_wrong_iface", 2084 SYSCTL_DESCR("log ARP packets arriving on the wrong" 2085 " interface"), 2086 NULL, 0, &log_wrong_iface, 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, "debug", 2092 SYSCTL_DESCR("Enable ARP DAD debug output"), 2093 NULL, 0, &arp_debug, 0, 2094 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2095 } 2096 2097 #endif /* INET */ 2098
Indexes created Tue Nov 10 00:26:44 UTC 2026