if_arp.c revision 1.302
1 /* $NetBSD: if_arp.c,v 1.302 2021/02/14 20:58:35 christos 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 1.302 2021/02/14 20:58:35 christos 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 #ifdef __NO_STRICT_ALIGNMENT 137 #define ARP_HDR_ALIGNED_P(ar) 1 138 #else 139 #define ARP_HDR_ALIGNED_P(ar) ((((vaddr_t) (ar)) & 1) == 0) 140 #endif 141 142 /* timers */ 143 static int arp_reachable = REACHABLE_TIME; 144 static int arp_retrans = RETRANS_TIMER; 145 static int arp_perform_nud = 1; 146 147 static bool arp_nud_enabled(struct ifnet *); 148 static unsigned int arp_llinfo_reachable(struct ifnet *); 149 static unsigned int arp_llinfo_retrans(struct ifnet *); 150 static union l3addr *arp_llinfo_holdsrc(struct llentry *, union l3addr *); 151 static void arp_llinfo_output(struct ifnet *, const union l3addr *, 152 const union l3addr *, const uint8_t *, const union l3addr *); 153 static void arp_llinfo_missed(struct ifnet *, const union l3addr *, 154 int16_t, struct mbuf *); 155 static void arp_free(struct llentry *, int); 156 157 static struct nd_domain arp_nd_domain = { 158 .nd_family = AF_INET, 159 .nd_delay = 5, /* delay first probe time 5 second */ 160 .nd_mmaxtries = 3, /* maximum broadcast query */ 161 .nd_umaxtries = 3, /* maximum unicast query */ 162 .nd_retransmultiple = BACKOFF_MULTIPLE, 163 .nd_maxretrans = MAX_RETRANS_TIMER, 164 .nd_maxnudhint = 0, /* max # of subsequent upper layer hints */ 165 .nd_maxqueuelen = 1, /* max # of packets in unresolved ND entries */ 166 .nd_nud_enabled = arp_nud_enabled, 167 .nd_reachable = arp_llinfo_reachable, 168 .nd_retrans = arp_llinfo_retrans, 169 .nd_holdsrc = arp_llinfo_holdsrc, 170 .nd_output = arp_llinfo_output, 171 .nd_missed = arp_llinfo_missed, 172 .nd_free = arp_free, 173 }; 174 175 int ip_dad_count = PROBE_NUM; 176 #ifdef ARP_DEBUG 177 int arp_debug = 1; 178 #else 179 int arp_debug = 0; 180 #endif 181 182 static void arp_init(void); 183 static void arp_dad_init(void); 184 185 static void arprequest(struct ifnet *, 186 const struct in_addr *, const struct in_addr *, 187 const uint8_t *, const uint8_t *); 188 static void arpannounce1(struct ifaddr *); 189 static struct sockaddr *arp_setgate(struct rtentry *, struct sockaddr *, 190 const struct sockaddr *); 191 static struct llentry *arpcreate(struct ifnet *, 192 const struct in_addr *, const struct sockaddr *, int); 193 static void in_arpinput(struct mbuf *); 194 static void in_revarpinput(struct mbuf *); 195 static void revarprequest(struct ifnet *); 196 197 static void arp_drainstub(void); 198 199 struct dadq; 200 static void arp_dad_timer(struct dadq *); 201 static void arp_dad_start(struct ifaddr *); 202 static void arp_dad_stop(struct ifaddr *); 203 static void arp_dad_duplicated(struct ifaddr *, const struct sockaddr_dl *); 204 205 struct ifqueue arpintrq = { 206 .ifq_head = NULL, 207 .ifq_tail = NULL, 208 .ifq_len = 0, 209 .ifq_maxlen = 50, 210 .ifq_drops = 0, 211 }; 212 static int useloopback = 1; /* use loopback interface for local traffic */ 213 214 static percpu_t *arpstat_percpu; 215 216 #define ARP_STAT_GETREF() _NET_STAT_GETREF(arpstat_percpu) 217 #define ARP_STAT_PUTREF() _NET_STAT_PUTREF(arpstat_percpu) 218 219 #define ARP_STATINC(x) _NET_STATINC(arpstat_percpu, x) 220 #define ARP_STATADD(x, v) _NET_STATADD(arpstat_percpu, x, v) 221 222 /* revarp state */ 223 static struct in_addr myip, srv_ip; 224 static int myip_initialized = 0; 225 static int revarp_in_progress = 0; 226 static struct ifnet *myip_ifp = NULL; 227 228 static int arp_drainwanted; 229 230 static int log_movements = 0; 231 static int log_permanent_modify = 1; 232 static int log_wrong_iface = 1; 233 234 DOMAIN_DEFINE(arpdomain); /* forward declare and add to link set */ 235 236 static void 237 arp_fasttimo(void) 238 { 239 if (arp_drainwanted) { 240 arp_drain(); 241 arp_drainwanted = 0; 242 } 243 } 244 245 static const struct protosw arpsw[] = { 246 { 247 .pr_type = 0, 248 .pr_domain = &arpdomain, 249 .pr_protocol = 0, 250 .pr_flags = 0, 251 .pr_input = 0, 252 .pr_ctlinput = 0, 253 .pr_ctloutput = 0, 254 .pr_usrreqs = 0, 255 .pr_init = arp_init, 256 .pr_fasttimo = arp_fasttimo, 257 .pr_slowtimo = 0, 258 .pr_drain = arp_drainstub, 259 } 260 }; 261 262 struct domain arpdomain = { 263 .dom_family = PF_ARP, 264 .dom_name = "arp", 265 .dom_protosw = arpsw, 266 .dom_protoswNPROTOSW = &arpsw[__arraycount(arpsw)], 267 #ifdef MBUFTRACE 268 .dom_mowner = MOWNER_INIT("internet", "arp"), 269 #endif 270 }; 271 272 static void sysctl_net_inet_arp_setup(struct sysctllog **); 273 274 void 275 arp_init(void) 276 { 277 278 sysctl_net_inet_arp_setup(NULL); 279 arpstat_percpu = percpu_alloc(sizeof(uint64_t) * ARP_NSTATS); 280 IFQ_LOCK_INIT(&arpintrq); 281 282 #ifdef MBUFTRACE 283 MOWNER_ATTACH(&arpdomain.dom_mowner); 284 #endif 285 286 nd_attach_domain(&arp_nd_domain); 287 arp_dad_init(); 288 } 289 290 static void 291 arp_drainstub(void) 292 { 293 arp_drainwanted = 1; 294 } 295 296 /* 297 * ARP protocol drain routine. Called when memory is in short supply. 298 * Called at splvm(); don't acquire softnet_lock as can be called from 299 * hardware interrupt handlers. 300 */ 301 void 302 arp_drain(void) 303 { 304 305 lltable_drain(AF_INET); 306 } 307 308 /* 309 * We set the gateway for RTF_CLONING routes to a "prototype" 310 * link-layer sockaddr whose interface type (if_type) and interface 311 * index (if_index) fields are prepared. 312 */ 313 static struct sockaddr * 314 arp_setgate(struct rtentry *rt, struct sockaddr *gate, 315 const struct sockaddr *netmask) 316 { 317 const struct ifnet *ifp = rt->rt_ifp; 318 uint8_t namelen = strlen(ifp->if_xname); 319 uint8_t addrlen = ifp->if_addrlen; 320 321 /* 322 * XXX: If this is a manually added route to interface 323 * such as older version of routed or gated might provide, 324 * restore cloning bit. 325 */ 326 if ((rt->rt_flags & RTF_HOST) == 0 && netmask != NULL && 327 satocsin(netmask)->sin_addr.s_addr != 0xffffffff) 328 rt->rt_flags |= RTF_CONNECTED; 329 330 if ((rt->rt_flags & (RTF_CONNECTED | RTF_LOCAL))) { 331 union { 332 struct sockaddr sa; 333 struct sockaddr_storage ss; 334 struct sockaddr_dl sdl; 335 } u; 336 /* 337 * Case 1: This route should come from a route to iface. 338 */ 339 sockaddr_dl_init(&u.sdl, sizeof(u.ss), 340 ifp->if_index, ifp->if_type, NULL, namelen, NULL, addrlen); 341 rt_setgate(rt, &u.sa); 342 gate = rt->rt_gateway; 343 } 344 return gate; 345 } 346 347 /* 348 * Parallel to llc_rtrequest. 349 */ 350 void 351 arp_rtrequest(int req, struct rtentry *rt, const struct rt_addrinfo *info) 352 { 353 struct sockaddr *gate = rt->rt_gateway; 354 struct in_ifaddr *ia; 355 struct ifaddr *ifa; 356 struct ifnet *ifp = rt->rt_ifp; 357 int bound; 358 int s; 359 360 if (req == RTM_LLINFO_UPD) { 361 if ((ifa = info->rti_ifa) != NULL) 362 arpannounce1(ifa); 363 return; 364 } 365 366 if ((rt->rt_flags & RTF_GATEWAY) != 0) { 367 if (req != RTM_ADD) 368 return; 369 370 /* 371 * linklayers with particular link MTU limitation. 372 */ 373 switch(ifp->if_type) { 374 #if NARCNET > 0 375 case IFT_ARCNET: 376 { 377 int arcipifmtu; 378 379 if (ifp->if_flags & IFF_LINK0) 380 arcipifmtu = arc_ipmtu; 381 else 382 arcipifmtu = ARCMTU; 383 if (ifp->if_mtu > arcipifmtu) 384 rt->rt_rmx.rmx_mtu = arcipifmtu; 385 break; 386 } 387 #endif 388 } 389 return; 390 } 391 392 switch (req) { 393 case RTM_SETGATE: 394 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 395 break; 396 case RTM_ADD: 397 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 398 if (gate == NULL) { 399 log(LOG_ERR, "%s: arp_setgate failed\n", __func__); 400 break; 401 } 402 if ((rt->rt_flags & RTF_CONNECTED) || 403 (rt->rt_flags & RTF_LOCAL)) { 404 /* 405 * linklayers with particular link MTU limitation. 406 */ 407 switch (ifp->if_type) { 408 #if NARCNET > 0 409 case IFT_ARCNET: 410 { 411 int arcipifmtu; 412 if (ifp->if_flags & IFF_LINK0) 413 arcipifmtu = arc_ipmtu; 414 else 415 arcipifmtu = ARCMTU; 416 417 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 418 (rt->rt_rmx.rmx_mtu > arcipifmtu || 419 (rt->rt_rmx.rmx_mtu == 0 && 420 ifp->if_mtu > arcipifmtu))) 421 rt->rt_rmx.rmx_mtu = arcipifmtu; 422 break; 423 } 424 #endif 425 } 426 if (rt->rt_flags & RTF_CONNECTED) 427 break; 428 } 429 430 bound = curlwp_bind(); 431 /* Announce a new entry if requested. */ 432 if (rt->rt_flags & RTF_ANNOUNCE) { 433 struct psref psref; 434 ia = in_get_ia_on_iface_psref( 435 satocsin(rt_getkey(rt))->sin_addr, ifp, &psref); 436 if (ia != NULL) { 437 arpannounce(ifp, &ia->ia_ifa, 438 CLLADDR(satocsdl(gate))); 439 ia4_release(ia, &psref); 440 } 441 } 442 443 if (gate->sa_family != AF_LINK || 444 gate->sa_len < sockaddr_dl_measure(0, ifp->if_addrlen)) { 445 log(LOG_DEBUG, "%s: bad gateway value\n", __func__); 446 goto out; 447 } 448 449 satosdl(gate)->sdl_type = ifp->if_type; 450 satosdl(gate)->sdl_index = ifp->if_index; 451 452 /* 453 * If the route is for a broadcast address mark it as such. 454 * This way we can avoid an expensive call to in_broadcast() 455 * in ip_output() most of the time (because the route passed 456 * to ip_output() is almost always a host route). 457 */ 458 if (rt->rt_flags & RTF_HOST && 459 !(rt->rt_flags & RTF_BROADCAST) && 460 in_broadcast(satocsin(rt_getkey(rt))->sin_addr, rt->rt_ifp)) 461 rt->rt_flags |= RTF_BROADCAST; 462 /* There is little point in resolving the broadcast address */ 463 if (rt->rt_flags & RTF_BROADCAST) 464 goto out; 465 466 /* 467 * When called from rt_ifa_addlocal, we cannot depend on that 468 * the address (rt_getkey(rt)) exits in the address list of the 469 * interface. So check RTF_LOCAL instead. 470 */ 471 if (rt->rt_flags & RTF_LOCAL) { 472 if (useloopback) { 473 rt->rt_ifp = lo0ifp; 474 rt->rt_rmx.rmx_mtu = 0; 475 } 476 goto out; 477 } 478 479 s = pserialize_read_enter(); 480 ia = in_get_ia_on_iface(satocsin(rt_getkey(rt))->sin_addr, ifp); 481 if (ia == NULL) { 482 pserialize_read_exit(s); 483 goto out; 484 } 485 486 if (useloopback) { 487 rt->rt_ifp = lo0ifp; 488 rt->rt_rmx.rmx_mtu = 0; 489 } 490 rt->rt_flags |= RTF_LOCAL; 491 492 if (ISSET(info->rti_flags, RTF_DONTCHANGEIFA)) { 493 pserialize_read_exit(s); 494 goto out; 495 } 496 /* 497 * make sure to set rt->rt_ifa to the interface 498 * address we are using, otherwise we will have trouble 499 * with source address selection. 500 */ 501 ifa = &ia->ia_ifa; 502 if (ifa != rt->rt_ifa) 503 /* Assume it doesn't sleep */ 504 rt_replace_ifa(rt, ifa); 505 pserialize_read_exit(s); 506 out: 507 curlwp_bindx(bound); 508 break; 509 } 510 } 511 512 /* 513 * Broadcast an ARP request. Caller specifies: 514 * - arp header source ip address 515 * - arp header target ip address 516 * - arp header source ethernet address 517 */ 518 static void 519 arprequest(struct ifnet *ifp, 520 const struct in_addr *sip, const struct in_addr *tip, 521 const uint8_t *saddr, const uint8_t *taddr) 522 { 523 struct mbuf *m; 524 struct arphdr *ah; 525 struct sockaddr sa; 526 uint64_t *arps; 527 528 KASSERT(sip != NULL); 529 KASSERT(tip != NULL); 530 KASSERT(saddr != NULL); 531 532 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 533 return; 534 MCLAIM(m, &arpdomain.dom_mowner); 535 switch (ifp->if_type) { 536 case IFT_IEEE1394: 537 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 538 ifp->if_addrlen; 539 break; 540 default: 541 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 542 2 * ifp->if_addrlen; 543 break; 544 } 545 m->m_pkthdr.len = m->m_len; 546 m_align(m, m->m_len); 547 ah = mtod(m, struct arphdr *); 548 memset(ah, 0, m->m_len); 549 switch (ifp->if_type) { 550 case IFT_IEEE1394: /* RFC2734 */ 551 /* fill it now for ar_tpa computation */ 552 ah->ar_hrd = htons(ARPHRD_IEEE1394); 553 break; 554 default: 555 /* ifp->if_output will fill ar_hrd */ 556 break; 557 } 558 ah->ar_pro = htons(ETHERTYPE_IP); 559 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 560 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 561 ah->ar_op = htons(ARPOP_REQUEST); 562 memcpy(ar_sha(ah), saddr, ah->ar_hln); 563 if (taddr == NULL) 564 m->m_flags |= M_BCAST; 565 else 566 memcpy(ar_tha(ah), taddr, ah->ar_hln); 567 memcpy(ar_spa(ah), sip, ah->ar_pln); 568 memcpy(ar_tpa(ah), tip, ah->ar_pln); 569 sa.sa_family = AF_ARP; 570 sa.sa_len = 2; 571 arps = ARP_STAT_GETREF(); 572 arps[ARP_STAT_SNDTOTAL]++; 573 arps[ARP_STAT_SENDREQUEST]++; 574 ARP_STAT_PUTREF(); 575 if_output_lock(ifp, ifp, m, &sa, NULL); 576 } 577 578 void 579 arpannounce(struct ifnet *ifp, struct ifaddr *ifa, const uint8_t *enaddr) 580 { 581 struct in_ifaddr *ia = ifatoia(ifa); 582 struct in_addr *ip = &IA_SIN(ifa)->sin_addr; 583 584 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) { 585 ARPLOG(LOG_DEBUG, "%s not ready\n", ARPLOGADDR(ip)); 586 return; 587 } 588 arprequest(ifp, ip, ip, enaddr, NULL); 589 } 590 591 static void 592 arpannounce1(struct ifaddr *ifa) 593 { 594 595 arpannounce(ifa->ifa_ifp, ifa, CLLADDR(ifa->ifa_ifp->if_sadl)); 596 } 597 598 /* 599 * Resolve an IP address into an ethernet address. If success, desten is 600 * filled in. If there is no entry in arptab, set one up and broadcast a 601 * request for the IP address. Hold onto this mbuf and resend it once the 602 * address is finally resolved. 603 * 604 * A return value of 0 indicates that desten has been filled in and the packet 605 * should be sent normally; a return value of EWOULDBLOCK indicates that the 606 * packet has been held pending resolution. Any other value indicates an 607 * error. 608 */ 609 int 610 arpresolve(struct ifnet *ifp, const struct rtentry *rt, struct mbuf *m, 611 const struct sockaddr *dst, void *desten, size_t destlen) 612 { 613 struct llentry *la; 614 const char *create_lookup; 615 int error; 616 617 #if NCARP > 0 618 if (rt != NULL && rt->rt_ifp->if_type == IFT_CARP) 619 ifp = rt->rt_ifp; 620 #endif 621 622 KASSERT(m != NULL); 623 624 la = arplookup(ifp, NULL, dst, 0); 625 if (la == NULL) 626 goto notfound; 627 628 if (la->la_flags & LLE_VALID && la->ln_state == ND_LLINFO_REACHABLE) { 629 KASSERT(destlen >= ifp->if_addrlen); 630 memcpy(desten, &la->ll_addr, ifp->if_addrlen); 631 LLE_RUNLOCK(la); 632 return 0; 633 } 634 635 notfound: 636 if (ifp->if_flags & IFF_NOARP) { 637 if (la != NULL) 638 LLE_RUNLOCK(la); 639 error = ENOTSUP; 640 goto bad; 641 } 642 643 if (la == NULL) { 644 struct rtentry *_rt; 645 646 create_lookup = "create"; 647 _rt = rtalloc1(dst, 0); 648 IF_AFDATA_WLOCK(ifp); 649 la = lla_create(LLTABLE(ifp), LLE_EXCLUSIVE, dst, _rt); 650 IF_AFDATA_WUNLOCK(ifp); 651 if (_rt != NULL) 652 rt_unref(_rt); 653 if (la == NULL) 654 ARP_STATINC(ARP_STAT_ALLOCFAIL); 655 else 656 la->ln_state = ND_LLINFO_NOSTATE; 657 } else if (LLE_TRY_UPGRADE(la) == 0) { 658 create_lookup = "lookup"; 659 LLE_RUNLOCK(la); 660 IF_AFDATA_RLOCK(ifp); 661 la = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst); 662 IF_AFDATA_RUNLOCK(ifp); 663 } 664 665 error = EINVAL; 666 if (la == NULL) { 667 log(LOG_DEBUG, 668 "%s: failed to %s llentry for %s on %s\n", 669 __func__, create_lookup, inet_ntoa(satocsin(dst)->sin_addr), 670 ifp->if_xname); 671 goto bad; 672 } 673 674 error = nd_resolve(la, rt, m, desten, destlen); 675 return error; 676 677 bad: 678 m_freem(m); 679 return error; 680 } 681 682 /* 683 * Common length and type checks are done here, 684 * then the protocol-specific routine is called. 685 */ 686 void 687 arpintr(void) 688 { 689 struct mbuf *m; 690 struct arphdr *ar; 691 int s; 692 int arplen; 693 struct ifnet *rcvif; 694 bool badhrd; 695 696 SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE(); 697 for (;;) { 698 699 IFQ_LOCK(&arpintrq); 700 IF_DEQUEUE(&arpintrq, m); 701 IFQ_UNLOCK(&arpintrq); 702 if (m == NULL) 703 goto out; 704 if ((m->m_flags & M_PKTHDR) == 0) 705 panic("arpintr"); 706 707 MCLAIM(m, &arpdomain.dom_mowner); 708 ARP_STATINC(ARP_STAT_RCVTOTAL); 709 710 if (__predict_false(m->m_len < sizeof(*ar))) { 711 if ((m = m_pullup(m, sizeof(*ar))) == NULL) 712 goto badlen; 713 } 714 ar = mtod(m, struct arphdr *); 715 KASSERT(POINTER_ALIGNED_P(ar, ARP_HDR_ALIGNMENT)); 716 717 rcvif = m_get_rcvif(m, &s); 718 if (__predict_false(rcvif == NULL)) { 719 ARP_STATINC(ARP_STAT_RCVNOINT); 720 goto free; 721 } 722 723 /* 724 * We don't want non-IEEE1394 ARP packets on IEEE1394 725 * interfaces, and vice versa. Our life depends on that. 726 */ 727 if (ntohs(ar->ar_hrd) == ARPHRD_IEEE1394) 728 badhrd = rcvif->if_type != IFT_IEEE1394; 729 else 730 badhrd = rcvif->if_type == IFT_IEEE1394; 731 732 m_put_rcvif(rcvif, &s); 733 734 if (badhrd) { 735 ARP_STATINC(ARP_STAT_RCVBADPROTO); 736 goto free; 737 } 738 739 arplen = sizeof(*ar) + 2 * ar->ar_hln + 2 * ar->ar_pln; 740 if (__predict_false(m->m_len < arplen)) { 741 if ((m = m_pullup(m, arplen)) == NULL) 742 goto badlen; 743 ar = mtod(m, struct arphdr *); 744 KASSERT(POINTER_ALIGNED_P(ar, ARP_HDR_ALIGNMENT)); 745 } 746 747 switch (ntohs(ar->ar_pro)) { 748 case ETHERTYPE_IP: 749 case ETHERTYPE_IPTRAILERS: 750 in_arpinput(m); 751 continue; 752 default: 753 ARP_STATINC(ARP_STAT_RCVBADPROTO); 754 goto free; 755 } 756 757 badlen: 758 ARP_STATINC(ARP_STAT_RCVBADLEN); 759 free: 760 m_freem(m); 761 } 762 763 out: 764 SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 765 return; /* XXX gcc */ 766 } 767 768 /* 769 * ARP for Internet protocols on 10 Mb/s Ethernet. Algorithm is that given in 770 * RFC 826. In addition, a sanity check is performed on the sender protocol 771 * address, to catch impersonators. 772 * 773 * We no longer handle negotiations for use of trailer protocol: formerly, ARP 774 * replied for protocol type ETHERTYPE_TRAIL sent along with IP replies if we 775 * wanted trailers sent to us, and also sent them in response to IP replies. 776 * This allowed either end to announce the desire to receive trailer packets. 777 * 778 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, but 779 * formerly didn't normally send requests. 780 */ 781 static void 782 in_arpinput(struct mbuf *m) 783 { 784 struct arphdr *ah; 785 struct ifnet *ifp, *rcvif = NULL; 786 struct llentry *la = NULL; 787 struct in_ifaddr *ia = NULL; 788 #if NBRIDGE > 0 789 struct in_ifaddr *bridge_ia = NULL; 790 #endif 791 #if NCARP > 0 792 uint32_t count = 0, index = 0; 793 #endif 794 struct sockaddr sa; 795 struct in_addr isaddr, itaddr, myaddr; 796 int op, rt_cmd, new_state = 0; 797 void *tha; 798 uint64_t *arps; 799 struct psref psref, psref_ia; 800 int s; 801 char ipbuf[INET_ADDRSTRLEN]; 802 bool find_source, do_dad; 803 804 if (__predict_false(m_makewritable(&m, 0, m->m_pkthdr.len, M_DONTWAIT))) 805 goto out; 806 ah = mtod(m, struct arphdr *); 807 op = ntohs(ah->ar_op); 808 809 if (ah->ar_pln != sizeof(struct in_addr)) 810 goto out; 811 812 ifp = if_get_bylla(ar_sha(ah), ah->ar_hln, &psref); 813 if (ifp) { 814 /* it's from me, ignore it. */ 815 if_put(ifp, &psref); 816 ARP_STATINC(ARP_STAT_RCVLOCALSHA); 817 goto out; 818 } 819 820 rcvif = ifp = m_get_rcvif_psref(m, &psref); 821 if (__predict_false(rcvif == NULL)) 822 goto out; 823 if (rcvif->if_flags & IFF_NOARP) 824 goto out; 825 826 memcpy(&isaddr, ar_spa(ah), sizeof(isaddr)); 827 memcpy(&itaddr, ar_tpa(ah), sizeof(itaddr)); 828 829 if (m->m_flags & (M_BCAST|M_MCAST)) 830 ARP_STATINC(ARP_STAT_RCVMCAST); 831 832 /* 833 * Search for a matching interface address 834 * or any address on the interface to use 835 * as a dummy address in the rest of this function. 836 * 837 * First try and find the source address for early 838 * duplicate address detection. 839 */ 840 if (in_nullhost(isaddr)) { 841 if (in_nullhost(itaddr)) /* very bogus ARP */ 842 goto out; 843 find_source = false; 844 myaddr = itaddr; 845 } else { 846 find_source = true; 847 myaddr = isaddr; 848 } 849 s = pserialize_read_enter(); 850 again: 851 IN_ADDRHASH_READER_FOREACH(ia, myaddr.s_addr) { 852 if (!in_hosteq(ia->ia_addr.sin_addr, myaddr)) 853 continue; 854 #if NCARP > 0 855 if (ia->ia_ifp->if_type == IFT_CARP && 856 ((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) == 857 (IFF_UP|IFF_RUNNING))) { 858 index++; 859 /* XXX: ar_hln? */ 860 if (ia->ia_ifp == rcvif && (ah->ar_hln >= 6) && 861 carp_iamatch(ia, ar_sha(ah), 862 &count, index)) { 863 break; 864 } 865 } else 866 #endif 867 if (ia->ia_ifp == rcvif) 868 break; 869 #if NBRIDGE > 0 870 /* 871 * If the interface we received the packet on 872 * is part of a bridge, check to see if we need 873 * to "bridge" the packet to ourselves at this 874 * layer. Note we still prefer a perfect match, 875 * but allow this weaker match if necessary. 876 */ 877 if (rcvif->if_bridge != NULL && 878 rcvif->if_bridge == ia->ia_ifp->if_bridge) 879 bridge_ia = ia; 880 #endif 881 } 882 883 #if NBRIDGE > 0 884 if (ia == NULL && bridge_ia != NULL) { 885 ia = bridge_ia; 886 m_put_rcvif_psref(rcvif, &psref); 887 rcvif = NULL; 888 /* FIXME */ 889 ifp = bridge_ia->ia_ifp; 890 } 891 #endif 892 893 /* If we failed to find the source address then find 894 * the target address. */ 895 if (ia == NULL && find_source && !in_nullhost(itaddr)) { 896 find_source = false; 897 myaddr = itaddr; 898 goto again; 899 } 900 901 if (ia != NULL) 902 ia4_acquire(ia, &psref_ia); 903 pserialize_read_exit(s); 904 905 if (ah->ar_hln != ifp->if_addrlen) { 906 ARP_STATINC(ARP_STAT_RCVBADLEN); 907 log(LOG_WARNING, 908 "arp from %s: addr len: new %d, i/f %d (ignored)\n", 909 IN_PRINT(ipbuf, &isaddr), ah->ar_hln, ifp->if_addrlen); 910 goto out; 911 } 912 913 /* Only do DaD if we have a matching address. */ 914 do_dad = (ia != NULL); 915 916 if (ia == NULL) { 917 ia = in_get_ia_on_iface_psref(isaddr, rcvif, &psref_ia); 918 if (ia == NULL) { 919 ia = in_get_ia_from_ifp_psref(ifp, &psref_ia); 920 if (ia == NULL) { 921 ARP_STATINC(ARP_STAT_RCVNOINT); 922 goto out; 923 } 924 } 925 } 926 927 myaddr = ia->ia_addr.sin_addr; 928 929 /* XXX checks for bridge case? */ 930 if (!memcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 931 ARP_STATINC(ARP_STAT_RCVBCASTSHA); 932 log(LOG_ERR, 933 "%s: arp: link address is broadcast for IP address %s!\n", 934 ifp->if_xname, IN_PRINT(ipbuf, &isaddr)); 935 goto out; 936 } 937 938 /* 939 * If the source IP address is zero, this is an RFC 5227 ARP probe 940 */ 941 if (in_nullhost(isaddr)) 942 ARP_STATINC(ARP_STAT_RCVZEROSPA); 943 else if (in_hosteq(isaddr, myaddr)) 944 ARP_STATINC(ARP_STAT_RCVLOCALSPA); 945 946 if (in_nullhost(itaddr)) 947 ARP_STATINC(ARP_STAT_RCVZEROTPA); 948 949 /* 950 * DAD check, RFC 5227. 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 (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 sockaddr_dl sdl, *sdlp; 965 966 sdlp = sockaddr_dl_init(&sdl, sizeof(sdl), 967 ifp->if_index, ifp->if_type, 968 NULL, 0, ar_sha(ah), ah->ar_hln); 969 arp_dad_duplicated((struct ifaddr *)ia, sdlp); 970 goto out; 971 } 972 973 /* 974 * If the target IP address is zero, ignore the packet. 975 * This prevents the code below from trying to answer 976 * when we are using IP address zero (booting). 977 */ 978 if (in_nullhost(itaddr)) 979 goto out; 980 981 if (in_nullhost(isaddr)) 982 goto reply; 983 984 if (in_hosteq(itaddr, myaddr)) 985 la = arpcreate(ifp, &isaddr, NULL, 1); 986 else 987 la = arplookup(ifp, &isaddr, NULL, 1); 988 if (la == NULL) 989 goto reply; 990 991 if ((la->la_flags & LLE_VALID) && 992 memcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) 993 { 994 char llabuf[LLA_ADDRSTRLEN], *llastr; 995 996 llastr = lla_snprintf(llabuf, sizeof(llabuf), 997 ar_sha(ah), ah->ar_hln); 998 999 if (la->la_flags & LLE_STATIC) { 1000 ARP_STATINC(ARP_STAT_RCVOVERPERM); 1001 if (!log_permanent_modify) 1002 goto out; 1003 log(LOG_INFO, 1004 "%s tried to overwrite permanent arp info" 1005 " for %s\n", llastr, IN_PRINT(ipbuf, &isaddr)); 1006 goto out; 1007 } else if (la->lle_tbl->llt_ifp != ifp) { 1008 /* XXX should not happen? */ 1009 ARP_STATINC(ARP_STAT_RCVOVERINT); 1010 if (!log_wrong_iface) 1011 goto out; 1012 log(LOG_INFO, 1013 "%s on %s tried to overwrite " 1014 "arp info for %s on %s\n", 1015 llastr, 1016 ifp->if_xname, IN_PRINT(ipbuf, &isaddr), 1017 la->lle_tbl->llt_ifp->if_xname); 1018 goto out; 1019 } else { 1020 ARP_STATINC(ARP_STAT_RCVOVER); 1021 if (log_movements) 1022 log(LOG_INFO, "arp info overwritten " 1023 "for %s by %s\n", 1024 IN_PRINT(ipbuf, &isaddr), llastr); 1025 } 1026 rt_cmd = RTM_CHANGE; 1027 new_state = ND_LLINFO_STALE; 1028 } else { 1029 if (op == ARPOP_REPLY && in_hosteq(itaddr, myaddr)) { 1030 /* This was a solicited ARP reply. */ 1031 la->ln_byhint = 0; 1032 new_state = ND_LLINFO_REACHABLE; 1033 } 1034 rt_cmd = la->la_flags & LLE_VALID ? 0 : RTM_ADD; 1035 } 1036 1037 KASSERT(ifp->if_sadl->sdl_alen == ifp->if_addrlen); 1038 1039 KASSERT(sizeof(la->ll_addr) >= ifp->if_addrlen); 1040 memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen); 1041 la->la_flags |= LLE_VALID; 1042 la->ln_asked = 0; 1043 if (new_state != 0) { 1044 la->ln_state = new_state; 1045 1046 if (new_state != ND_LLINFO_REACHABLE || 1047 !(la->la_flags & LLE_STATIC)) 1048 { 1049 int timer = ND_TIMER_GC; 1050 1051 if (new_state == ND_LLINFO_REACHABLE) 1052 timer = ND_TIMER_REACHABLE; 1053 nd_set_timer(la, timer); 1054 } 1055 } 1056 1057 if (rt_cmd != 0) { 1058 struct sockaddr_in sin; 1059 1060 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 1061 rt_clonedmsg(rt_cmd, NULL, sintosa(&sin), ar_sha(ah), ifp); 1062 } 1063 1064 if (la->la_hold != NULL) { 1065 int n = la->la_numheld; 1066 struct mbuf *m_hold, *m_hold_next; 1067 struct sockaddr_in sin; 1068 1069 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 1070 1071 m_hold = la->la_hold; 1072 la->la_hold = NULL; 1073 la->la_numheld = 0; 1074 /* 1075 * We have to unlock here because if_output would call 1076 * arpresolve 1077 */ 1078 LLE_WUNLOCK(la); 1079 ARP_STATADD(ARP_STAT_DFRSENT, n); 1080 ARP_STATADD(ARP_STAT_DFRTOTAL, n); 1081 for (; m_hold != NULL; m_hold = m_hold_next) { 1082 m_hold_next = m_hold->m_nextpkt; 1083 m_hold->m_nextpkt = NULL; 1084 if_output_lock(ifp, ifp, m_hold, sintosa(&sin), NULL); 1085 } 1086 } else 1087 LLE_WUNLOCK(la); 1088 la = NULL; 1089 1090 reply: 1091 if (la != NULL) { 1092 LLE_WUNLOCK(la); 1093 la = NULL; 1094 } 1095 if (op != ARPOP_REQUEST) { 1096 if (op == ARPOP_REPLY) 1097 ARP_STATINC(ARP_STAT_RCVREPLY); 1098 goto out; 1099 } 1100 ARP_STATINC(ARP_STAT_RCVREQUEST); 1101 if (in_hosteq(itaddr, myaddr)) { 1102 /* If our address is unusable, don't reply */ 1103 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) 1104 goto out; 1105 /* I am the target */ 1106 tha = ar_tha(ah); 1107 if (tha) 1108 memcpy(tha, ar_sha(ah), ah->ar_hln); 1109 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1110 } else { 1111 /* Proxy ARP */ 1112 struct llentry *lle = NULL; 1113 struct sockaddr_in sin; 1114 1115 #if NCARP > 0 1116 if (ifp->if_type == IFT_CARP) { 1117 struct ifnet *_rcvif = m_get_rcvif(m, &s); 1118 int iftype = 0; 1119 if (__predict_true(_rcvif != NULL)) 1120 iftype = _rcvif->if_type; 1121 m_put_rcvif(_rcvif, &s); 1122 if (iftype != IFT_CARP) 1123 goto out; 1124 } 1125 #endif 1126 1127 tha = ar_tha(ah); 1128 1129 sockaddr_in_init(&sin, &itaddr, 0); 1130 1131 IF_AFDATA_RLOCK(ifp); 1132 lle = lla_lookup(LLTABLE(ifp), 0, (struct sockaddr *)&sin); 1133 IF_AFDATA_RUNLOCK(ifp); 1134 1135 if ((lle != NULL) && (lle->la_flags & LLE_PUB)) { 1136 if (tha) 1137 memcpy(tha, ar_sha(ah), ah->ar_hln); 1138 memcpy(ar_sha(ah), &lle->ll_addr, ah->ar_hln); 1139 LLE_RUNLOCK(lle); 1140 } else { 1141 if (lle != NULL) 1142 LLE_RUNLOCK(lle); 1143 goto out; 1144 } 1145 } 1146 ia4_release(ia, &psref_ia); 1147 1148 /* 1149 * XXX XXX: Here we're recycling the mbuf. But the mbuf could have 1150 * other mbufs in its chain, and just overwriting m->m_pkthdr.len 1151 * would be wrong in this case (the length becomes smaller than the 1152 * real chain size). 1153 * 1154 * This can theoretically cause bugs in the lower layers (drivers, 1155 * and L2encap), in some corner cases. 1156 */ 1157 memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); 1158 memcpy(ar_spa(ah), &itaddr, ah->ar_pln); 1159 ah->ar_op = htons(ARPOP_REPLY); 1160 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 1161 switch (ifp->if_type) { 1162 case IFT_IEEE1394: 1163 /* ieee1394 arp reply is broadcast */ 1164 m->m_flags &= ~M_MCAST; 1165 m->m_flags |= M_BCAST; 1166 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + ah->ar_hln; 1167 break; 1168 default: 1169 m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */ 1170 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); 1171 break; 1172 } 1173 m->m_pkthdr.len = m->m_len; 1174 sa.sa_family = AF_ARP; 1175 sa.sa_len = 2; 1176 arps = ARP_STAT_GETREF(); 1177 arps[ARP_STAT_SNDTOTAL]++; 1178 arps[ARP_STAT_SNDREPLY]++; 1179 ARP_STAT_PUTREF(); 1180 if_output_lock(ifp, ifp, m, &sa, NULL); 1181 if (rcvif != NULL) 1182 m_put_rcvif_psref(rcvif, &psref); 1183 return; 1184 1185 out: 1186 if (la != NULL) 1187 LLE_WUNLOCK(la); 1188 if (ia != NULL) 1189 ia4_release(ia, &psref_ia); 1190 if (rcvif != NULL) 1191 m_put_rcvif_psref(rcvif, &psref); 1192 m_freem(m); 1193 } 1194 1195 /* 1196 * Lookup or a new address in arptab. 1197 */ 1198 struct llentry * 1199 arplookup(struct ifnet *ifp, const struct in_addr *addr, 1200 const struct sockaddr *sa, int wlock) 1201 { 1202 struct sockaddr_in sin; 1203 struct llentry *la; 1204 int flags = wlock ? LLE_EXCLUSIVE : 0; 1205 1206 if (sa == NULL) { 1207 KASSERT(addr != NULL); 1208 sockaddr_in_init(&sin, addr, 0); 1209 sa = sintocsa(&sin); 1210 } 1211 1212 IF_AFDATA_RLOCK(ifp); 1213 la = lla_lookup(LLTABLE(ifp), flags, sa); 1214 IF_AFDATA_RUNLOCK(ifp); 1215 1216 return la; 1217 } 1218 1219 static struct llentry * 1220 arpcreate(struct ifnet *ifp, const struct in_addr *addr, 1221 const struct sockaddr *sa, int wlock) 1222 { 1223 struct sockaddr_in sin; 1224 struct llentry *la; 1225 int flags = wlock ? LLE_EXCLUSIVE : 0; 1226 1227 if (sa == NULL) { 1228 KASSERT(addr != NULL); 1229 sockaddr_in_init(&sin, addr, 0); 1230 sa = sintocsa(&sin); 1231 } 1232 1233 la = arplookup(ifp, addr, sa, wlock); 1234 1235 if (la == NULL) { 1236 struct rtentry *rt; 1237 1238 rt = rtalloc1(sa, 0); 1239 IF_AFDATA_WLOCK(ifp); 1240 la = lla_create(LLTABLE(ifp), flags, sa, rt); 1241 IF_AFDATA_WUNLOCK(ifp); 1242 if (rt != NULL) 1243 rt_unref(rt); 1244 1245 if (la != NULL) 1246 la->ln_state = ND_LLINFO_NOSTATE; 1247 } 1248 1249 return la; 1250 } 1251 1252 int 1253 arpioctl(u_long cmd, void *data) 1254 { 1255 1256 return EOPNOTSUPP; 1257 } 1258 1259 void 1260 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1261 { 1262 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1263 1264 ifa->ifa_rtrequest = arp_rtrequest; 1265 ifa->ifa_flags |= RTF_CONNECTED; 1266 1267 /* ARP will handle DAD for this address. */ 1268 if (in_nullhost(IA_SIN(ifa)->sin_addr)) { 1269 if (ia->ia_dad_stop != NULL) /* safety */ 1270 ia->ia_dad_stop(ifa); 1271 ia->ia_dad_start = NULL; 1272 ia->ia_dad_stop = NULL; 1273 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1274 } else { 1275 ia->ia_dad_start = arp_dad_start; 1276 ia->ia_dad_stop = arp_dad_stop; 1277 if (ia->ia4_flags & IN_IFF_TRYTENTATIVE && ip_dad_enabled()) 1278 ia->ia4_flags |= IN_IFF_TENTATIVE; 1279 else 1280 arpannounce1(ifa); 1281 } 1282 } 1283 1284 static bool 1285 arp_nud_enabled(__unused struct ifnet *ifp) 1286 { 1287 1288 return arp_perform_nud != 0; 1289 } 1290 1291 static unsigned int 1292 arp_llinfo_reachable(__unused struct ifnet *ifp) 1293 { 1294 1295 return arp_reachable; 1296 } 1297 1298 static unsigned int 1299 arp_llinfo_retrans(__unused struct ifnet *ifp) 1300 { 1301 1302 return arp_retrans; 1303 } 1304 1305 /* 1306 * Gets source address of the first packet in hold queue 1307 * and stores it in @src. 1308 * Returns pointer to @src (if hold queue is not empty) or NULL. 1309 */ 1310 static union l3addr * 1311 arp_llinfo_holdsrc(struct llentry *ln, union l3addr *src) 1312 { 1313 struct ip *ip; 1314 1315 if (ln == NULL || ln->ln_hold == NULL) 1316 return NULL; 1317 1318 /* 1319 * assuming every packet in ln_hold has the same IP header 1320 */ 1321 ip = mtod(ln->ln_hold, struct ip *); 1322 /* XXX pullup? */ 1323 if (sizeof(*ip) < ln->ln_hold->m_len) 1324 src->addr4 = ip->ip_src; 1325 else 1326 src = NULL; 1327 1328 return src; 1329 } 1330 1331 static void 1332 arp_llinfo_output(struct ifnet *ifp, __unused const union l3addr *daddr, 1333 const union l3addr *taddr, const uint8_t *tlladdr, 1334 const union l3addr *hsrc) 1335 { 1336 struct in_addr tip = taddr->addr4, sip = zeroin_addr; 1337 const uint8_t *slladdr = CLLADDR(ifp->if_sadl); 1338 1339 if (hsrc != NULL) { 1340 struct in_ifaddr *ia; 1341 struct psref psref; 1342 1343 ia = in_get_ia_on_iface_psref(hsrc->addr4, ifp, &psref); 1344 if (ia != NULL) { 1345 sip = hsrc->addr4; 1346 ia4_release(ia, &psref); 1347 } 1348 } 1349 1350 if (sip.s_addr == INADDR_ANY) { 1351 struct sockaddr_in dst; 1352 struct rtentry *rt; 1353 1354 sockaddr_in_init(&dst, &tip, 0); 1355 rt = rtalloc1(sintosa(&dst), 0); 1356 if (rt != NULL) { 1357 if (rt->rt_ifp == ifp && 1358 rt->rt_ifa != NULL && 1359 rt->rt_ifa->ifa_addr->sa_family == AF_INET) 1360 sip = satosin(rt->rt_ifa->ifa_addr)->sin_addr; 1361 rt_unref(rt); 1362 } 1363 if (sip.s_addr == INADDR_ANY) { 1364 char ipbuf[INET_ADDRSTRLEN]; 1365 1366 log(LOG_DEBUG, "source can't be " 1367 "determined: dst=%s\n", 1368 IN_PRINT(ipbuf, &tip)); 1369 return; 1370 } 1371 } 1372 1373 arprequest(ifp, &sip, &tip, slladdr, tlladdr); 1374 } 1375 1376 1377 static void 1378 arp_llinfo_missed(struct ifnet *ifp, const union l3addr *taddr, 1379 __unused int16_t type, struct mbuf *m) 1380 { 1381 struct in_addr mdaddr = zeroin_addr; 1382 struct sockaddr_in dsin, tsin; 1383 struct sockaddr *sa; 1384 1385 if (m != NULL) { 1386 struct ip *ip = mtod(m, struct ip *); 1387 1388 if (sizeof(*ip) < m->m_len) 1389 mdaddr = ip->ip_src; 1390 1391 /* ip_input() will send ICMP_UNREACH_HOST, not us. */ 1392 m_freem(m); 1393 } 1394 1395 if (mdaddr.s_addr != INADDR_ANY) { 1396 sockaddr_in_init(&dsin, &mdaddr, 0); 1397 sa = sintosa(&dsin); 1398 } else 1399 sa = NULL; 1400 1401 sockaddr_in_init(&tsin, &taddr->addr4, 0); 1402 rt_clonedmsg(RTM_MISS, sa, sintosa(&tsin), NULL, ifp); 1403 } 1404 1405 static void 1406 arp_free(struct llentry *ln, int gc) 1407 { 1408 struct ifnet *ifp; 1409 1410 KASSERT(ln != NULL); 1411 LLE_WLOCK_ASSERT(ln); 1412 1413 ifp = ln->lle_tbl->llt_ifp; 1414 1415 if (ln->la_flags & LLE_VALID || gc) { 1416 struct sockaddr_in sin; 1417 const char *lladdr; 1418 1419 sockaddr_in_init(&sin, &ln->r_l3addr.addr4, 0); 1420 lladdr = ln->la_flags & LLE_VALID ? 1421 (const char *)&ln->ll_addr : NULL; 1422 rt_clonedmsg(RTM_DELETE, NULL, sintosa(&sin), lladdr, ifp); 1423 } 1424 1425 /* 1426 * Save to unlock. We still hold an extra reference and will not 1427 * free(9) in llentry_free() if someone else holds one as well. 1428 */ 1429 LLE_WUNLOCK(ln); 1430 IF_AFDATA_LOCK(ifp); 1431 LLE_WLOCK(ln); 1432 1433 lltable_free_entry(LLTABLE(ifp), ln); 1434 1435 IF_AFDATA_UNLOCK(ifp); 1436 } 1437 1438 /* 1439 * Upper-layer reachability hint for Neighbor Unreachability Detection. 1440 * 1441 * XXX cost-effective methods? 1442 */ 1443 void 1444 arp_nud_hint(struct rtentry *rt) 1445 { 1446 struct llentry *ln; 1447 struct ifnet *ifp; 1448 1449 if (rt == NULL) 1450 return; 1451 1452 ifp = rt->rt_ifp; 1453 ln = arplookup(ifp, NULL, rt_getkey(rt), 1); 1454 nd_nud_hint(ln); 1455 } 1456 1457 TAILQ_HEAD(dadq_head, dadq); 1458 struct dadq { 1459 TAILQ_ENTRY(dadq) dad_list; 1460 struct ifaddr *dad_ifa; 1461 int dad_count; /* max ARP to send */ 1462 int dad_arp_tcount; /* # of trials to send ARP */ 1463 int dad_arp_ocount; /* ARP sent so far */ 1464 int dad_arp_announce; /* max ARP announcements */ 1465 int dad_arp_acount; /* # of announcements */ 1466 struct callout dad_timer_ch; 1467 }; 1468 1469 static struct dadq_head dadq; 1470 static int dad_maxtry = 15; /* max # of *tries* to transmit DAD packet */ 1471 static kmutex_t arp_dad_lock; 1472 1473 static void 1474 arp_dad_init(void) 1475 { 1476 1477 TAILQ_INIT(&dadq); 1478 mutex_init(&arp_dad_lock, MUTEX_DEFAULT, IPL_NONE); 1479 } 1480 1481 static struct dadq * 1482 arp_dad_find(struct ifaddr *ifa) 1483 { 1484 struct dadq *dp; 1485 1486 KASSERT(mutex_owned(&arp_dad_lock)); 1487 1488 TAILQ_FOREACH(dp, &dadq, dad_list) { 1489 if (dp->dad_ifa == ifa) 1490 return dp; 1491 } 1492 return NULL; 1493 } 1494 1495 static void 1496 arp_dad_starttimer(struct dadq *dp, int ticks) 1497 { 1498 1499 callout_reset(&dp->dad_timer_ch, ticks, 1500 (void (*)(void *))arp_dad_timer, dp); 1501 } 1502 1503 static void 1504 arp_dad_stoptimer(struct dadq *dp) 1505 { 1506 1507 KASSERT(mutex_owned(&arp_dad_lock)); 1508 1509 TAILQ_REMOVE(&dadq, dp, dad_list); 1510 /* Tell the timer that dp is being destroyed. */ 1511 dp->dad_ifa = NULL; 1512 callout_halt(&dp->dad_timer_ch, &arp_dad_lock); 1513 } 1514 1515 static void 1516 arp_dad_destroytimer(struct dadq *dp) 1517 { 1518 1519 callout_destroy(&dp->dad_timer_ch); 1520 KASSERT(dp->dad_ifa == NULL); 1521 kmem_intr_free(dp, sizeof(*dp)); 1522 } 1523 1524 static void 1525 arp_dad_output(struct dadq *dp, struct ifaddr *ifa) 1526 { 1527 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1528 struct ifnet *ifp = ifa->ifa_ifp; 1529 struct in_addr sip; 1530 1531 dp->dad_arp_tcount++; 1532 if ((ifp->if_flags & IFF_UP) == 0) 1533 return; 1534 if ((ifp->if_flags & IFF_RUNNING) == 0) 1535 return; 1536 1537 dp->dad_arp_tcount = 0; 1538 dp->dad_arp_ocount++; 1539 1540 memset(&sip, 0, sizeof(sip)); 1541 arprequest(ifa->ifa_ifp, &sip, &ia->ia_addr.sin_addr, 1542 CLLADDR(ifa->ifa_ifp->if_sadl), NULL); 1543 } 1544 1545 /* 1546 * Start Duplicate Address Detection (DAD) for specified interface address. 1547 */ 1548 static void 1549 arp_dad_start(struct ifaddr *ifa) 1550 { 1551 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1552 struct dadq *dp; 1553 char ipbuf[INET_ADDRSTRLEN]; 1554 1555 /* 1556 * If we don't need DAD, don't do it. 1557 * - DAD is disabled 1558 */ 1559 if (!(ia->ia4_flags & IN_IFF_TENTATIVE)) { 1560 log(LOG_DEBUG, 1561 "%s: called with non-tentative address %s(%s)\n", __func__, 1562 IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1563 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1564 return; 1565 } 1566 if (!ip_dad_enabled()) { 1567 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1568 rt_addrmsg(RTM_NEWADDR, ifa); 1569 arpannounce1(ifa); 1570 return; 1571 } 1572 KASSERT(ifa->ifa_ifp != NULL); 1573 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) 1574 return; 1575 1576 dp = kmem_intr_alloc(sizeof(*dp), KM_NOSLEEP); 1577 1578 mutex_enter(&arp_dad_lock); 1579 if (arp_dad_find(ifa) != NULL) { 1580 mutex_exit(&arp_dad_lock); 1581 /* DAD already in progress */ 1582 if (dp != NULL) 1583 kmem_intr_free(dp, sizeof(*dp)); 1584 return; 1585 } 1586 1587 if (dp == NULL) { 1588 mutex_exit(&arp_dad_lock); 1589 log(LOG_ERR, "%s: memory allocation failed for %s(%s)\n", 1590 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1591 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1592 return; 1593 } 1594 1595 /* 1596 * Send ARP packet for DAD, ip_dad_count times. 1597 * Note that we must delay the first transmission. 1598 */ 1599 callout_init(&dp->dad_timer_ch, CALLOUT_MPSAFE); 1600 dp->dad_ifa = ifa; 1601 ifaref(ifa); /* just for safety */ 1602 dp->dad_count = ip_dad_count; 1603 dp->dad_arp_announce = 0; /* Will be set when starting to announce */ 1604 dp->dad_arp_acount = dp->dad_arp_ocount = dp->dad_arp_tcount = 0; 1605 TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list); 1606 1607 ARPLOG(LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1608 ARPLOGADDR(&ia->ia_addr.sin_addr)); 1609 1610 arp_dad_starttimer(dp, cprng_fast32() % (PROBE_WAIT * hz)); 1611 1612 mutex_exit(&arp_dad_lock); 1613 } 1614 1615 /* 1616 * terminate DAD unconditionally. used for address removals. 1617 */ 1618 static void 1619 arp_dad_stop(struct ifaddr *ifa) 1620 { 1621 struct dadq *dp; 1622 1623 mutex_enter(&arp_dad_lock); 1624 dp = arp_dad_find(ifa); 1625 if (dp == NULL) { 1626 mutex_exit(&arp_dad_lock); 1627 /* DAD wasn't started yet */ 1628 return; 1629 } 1630 1631 arp_dad_stoptimer(dp); 1632 1633 mutex_exit(&arp_dad_lock); 1634 1635 arp_dad_destroytimer(dp); 1636 ifafree(ifa); 1637 } 1638 1639 static void 1640 arp_dad_timer(struct dadq *dp) 1641 { 1642 struct ifaddr *ifa; 1643 struct in_ifaddr *ia; 1644 char ipbuf[INET_ADDRSTRLEN]; 1645 bool need_free = false; 1646 1647 KERNEL_LOCK_UNLESS_NET_MPSAFE(); 1648 mutex_enter(&arp_dad_lock); 1649 1650 ifa = dp->dad_ifa; 1651 if (ifa == NULL) { 1652 /* dp is being destroyed by someone. Do nothing. */ 1653 goto done; 1654 } 1655 1656 ia = (struct in_ifaddr *)ifa; 1657 if (ia->ia4_flags & IN_IFF_DUPLICATED) { 1658 log(LOG_ERR, "%s: called with duplicate address %s(%s)\n", 1659 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1660 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1661 goto done; 1662 } 1663 if ((ia->ia4_flags & IN_IFF_TENTATIVE) == 0 && dp->dad_arp_acount == 0) 1664 { 1665 log(LOG_ERR, "%s: called with non-tentative address %s(%s)\n", 1666 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1667 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1668 goto done; 1669 } 1670 1671 /* timeouted with IFF_{RUNNING,UP} check */ 1672 if (dp->dad_arp_tcount > dad_maxtry) { 1673 ARPLOG(LOG_INFO, "%s: could not run DAD, driver problem?\n", 1674 if_name(ifa->ifa_ifp)); 1675 1676 arp_dad_stoptimer(dp); 1677 need_free = true; 1678 goto done; 1679 } 1680 1681 /* Need more checks? */ 1682 if (dp->dad_arp_ocount < dp->dad_count) { 1683 int adelay; 1684 1685 /* 1686 * We have more ARP to go. Send ARP packet for DAD. 1687 */ 1688 arp_dad_output(dp, ifa); 1689 if (dp->dad_arp_ocount < dp->dad_count) 1690 adelay = (PROBE_MIN * hz) + 1691 (cprng_fast32() % 1692 ((PROBE_MAX * hz) - (PROBE_MIN * hz))); 1693 else 1694 adelay = ANNOUNCE_WAIT * hz; 1695 arp_dad_starttimer(dp, adelay); 1696 goto done; 1697 } else if (dp->dad_arp_acount == 0) { 1698 /* 1699 * We are done with DAD. 1700 * No duplicate address found. 1701 */ 1702 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1703 rt_addrmsg(RTM_NEWADDR, ifa); 1704 ARPLOG(LOG_DEBUG, 1705 "%s: DAD complete for %s - no duplicates found\n", 1706 if_name(ifa->ifa_ifp), ARPLOGADDR(&ia->ia_addr.sin_addr)); 1707 dp->dad_arp_announce = ANNOUNCE_NUM; 1708 goto announce; 1709 } else if (dp->dad_arp_acount < dp->dad_arp_announce) { 1710 announce: 1711 /* 1712 * Announce the address. 1713 */ 1714 arpannounce1(ifa); 1715 dp->dad_arp_acount++; 1716 if (dp->dad_arp_acount < dp->dad_arp_announce) { 1717 arp_dad_starttimer(dp, ANNOUNCE_INTERVAL * hz); 1718 goto done; 1719 } 1720 ARPLOG(LOG_DEBUG, 1721 "%s: ARP announcement complete for %s\n", 1722 if_name(ifa->ifa_ifp), ARPLOGADDR(&ia->ia_addr.sin_addr)); 1723 } 1724 1725 arp_dad_stoptimer(dp); 1726 need_free = true; 1727 done: 1728 mutex_exit(&arp_dad_lock); 1729 1730 if (need_free) { 1731 arp_dad_destroytimer(dp); 1732 KASSERT(ifa != NULL); 1733 ifafree(ifa); 1734 } 1735 1736 KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 1737 } 1738 1739 static void 1740 arp_dad_duplicated(struct ifaddr *ifa, const struct sockaddr_dl *from) 1741 { 1742 struct in_ifaddr *ia = ifatoia(ifa); 1743 struct ifnet *ifp = ifa->ifa_ifp; 1744 char ipbuf[INET_ADDRSTRLEN], llabuf[LLA_ADDRSTRLEN]; 1745 const char *iastr, *llastr; 1746 1747 iastr = IN_PRINT(ipbuf, &ia->ia_addr.sin_addr); 1748 if (__predict_false(from == NULL)) 1749 llastr = NULL; 1750 else 1751 llastr = lla_snprintf(llabuf, sizeof(llabuf), 1752 CLLADDR(from), from->sdl_alen); 1753 1754 if (ia->ia4_flags & (IN_IFF_TENTATIVE|IN_IFF_DUPLICATED)) { 1755 log(LOG_ERR, 1756 "%s: DAD duplicate address %s from %s\n", 1757 if_name(ifp), iastr, llastr); 1758 } else if (ia->ia_dad_defended == 0 || 1759 ia->ia_dad_defended < time_uptime - DEFEND_INTERVAL) { 1760 ia->ia_dad_defended = time_uptime; 1761 arpannounce1(ifa); 1762 log(LOG_ERR, 1763 "%s: DAD defended address %s from %s\n", 1764 if_name(ifp), iastr, llastr); 1765 return; 1766 } else { 1767 /* If DAD is disabled, just report the duplicate. */ 1768 if (!ip_dad_enabled()) { 1769 log(LOG_ERR, 1770 "%s: DAD ignoring duplicate address %s from %s\n", 1771 if_name(ifp), iastr, llastr); 1772 return; 1773 } 1774 log(LOG_ERR, 1775 "%s: DAD defence failed for %s from %s\n", 1776 if_name(ifp), iastr, llastr); 1777 } 1778 1779 arp_dad_stop(ifa); 1780 1781 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1782 if ((ia->ia4_flags & IN_IFF_DUPLICATED) == 0) { 1783 ia->ia4_flags |= IN_IFF_DUPLICATED; 1784 /* Inform the routing socket of the duplicate address */ 1785 rt_addrmsg_src(RTM_NEWADDR, ifa, (const struct sockaddr *)from); 1786 } 1787 } 1788 1789 /* 1790 * Called from 10 Mb/s Ethernet interrupt handlers 1791 * when ether packet type ETHERTYPE_REVARP 1792 * is received. Common length and type checks are done here, 1793 * then the protocol-specific routine is called. 1794 */ 1795 void 1796 revarpinput(struct mbuf *m) 1797 { 1798 struct arphdr *ar; 1799 int arplen; 1800 1801 arplen = sizeof(struct arphdr); 1802 if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL) 1803 return; 1804 ar = mtod(m, struct arphdr *); 1805 1806 if (ntohs(ar->ar_hrd) == ARPHRD_IEEE1394) { 1807 goto out; 1808 } 1809 1810 arplen = sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln); 1811 if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL) 1812 return; 1813 ar = mtod(m, struct arphdr *); 1814 1815 switch (ntohs(ar->ar_pro)) { 1816 case ETHERTYPE_IP: 1817 case ETHERTYPE_IPTRAILERS: 1818 in_revarpinput(m); 1819 return; 1820 1821 default: 1822 break; 1823 } 1824 1825 out: 1826 m_freem(m); 1827 } 1828 1829 /* 1830 * RARP for Internet protocols on 10 Mb/s Ethernet. 1831 * Algorithm is that given in RFC 903. 1832 * We are only using for bootstrap purposes to get an ip address for one of 1833 * our interfaces. Thus we support no user-interface. 1834 * 1835 * Since the contents of the RARP reply are specific to the interface that 1836 * sent the request, this code must ensure that they are properly associated. 1837 * 1838 * Note: also supports ARP via RARP packets, per the RFC. 1839 */ 1840 void 1841 in_revarpinput(struct mbuf *m) 1842 { 1843 struct arphdr *ah; 1844 void *tha; 1845 int op; 1846 struct ifnet *rcvif; 1847 int s; 1848 1849 ah = mtod(m, struct arphdr *); 1850 op = ntohs(ah->ar_op); 1851 1852 rcvif = m_get_rcvif(m, &s); 1853 if (__predict_false(rcvif == NULL)) 1854 goto out; 1855 if (rcvif->if_flags & IFF_NOARP) 1856 goto out; 1857 1858 switch (rcvif->if_type) { 1859 case IFT_IEEE1394: 1860 /* ARP without target hardware address is not supported */ 1861 goto out; 1862 default: 1863 break; 1864 } 1865 1866 switch (op) { 1867 case ARPOP_REQUEST: 1868 case ARPOP_REPLY: /* per RFC */ 1869 m_put_rcvif(rcvif, &s); 1870 in_arpinput(m); 1871 return; 1872 case ARPOP_REVREPLY: 1873 break; 1874 case ARPOP_REVREQUEST: /* handled by rarpd(8) */ 1875 default: 1876 goto out; 1877 } 1878 if (!revarp_in_progress) 1879 goto out; 1880 if (rcvif != myip_ifp) /* !same interface */ 1881 goto out; 1882 if (myip_initialized) 1883 goto wake; 1884 tha = ar_tha(ah); 1885 if (tha == NULL) 1886 goto out; 1887 if (ah->ar_pln != sizeof(struct in_addr)) 1888 goto out; 1889 if (ah->ar_hln != rcvif->if_sadl->sdl_alen) 1890 goto out; 1891 if (memcmp(tha, CLLADDR(rcvif->if_sadl), rcvif->if_sadl->sdl_alen)) 1892 goto out; 1893 memcpy(&srv_ip, ar_spa(ah), sizeof(srv_ip)); 1894 memcpy(&myip, ar_tpa(ah), sizeof(myip)); 1895 myip_initialized = 1; 1896 wake: /* Do wakeup every time in case it was missed. */ 1897 wakeup((void *)&myip); 1898 1899 out: 1900 m_put_rcvif(rcvif, &s); 1901 m_freem(m); 1902 } 1903 1904 /* 1905 * Send a RARP request for the ip address of the specified interface. 1906 * The request should be RFC 903-compliant. 1907 */ 1908 static void 1909 revarprequest(struct ifnet *ifp) 1910 { 1911 struct sockaddr sa; 1912 struct mbuf *m; 1913 struct arphdr *ah; 1914 void *tha; 1915 1916 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 1917 return; 1918 MCLAIM(m, &arpdomain.dom_mowner); 1919 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) + 1920 2*ifp->if_addrlen; 1921 m->m_pkthdr.len = m->m_len; 1922 m_align(m, m->m_len); 1923 ah = mtod(m, struct arphdr *); 1924 memset(ah, 0, m->m_len); 1925 ah->ar_pro = htons(ETHERTYPE_IP); 1926 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 1927 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 1928 ah->ar_op = htons(ARPOP_REVREQUEST); 1929 1930 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1931 tha = ar_tha(ah); 1932 if (tha == NULL) { 1933 m_free(m); 1934 return; 1935 } 1936 memcpy(tha, CLLADDR(ifp->if_sadl), ah->ar_hln); 1937 1938 sa.sa_family = AF_ARP; 1939 sa.sa_len = 2; 1940 m->m_flags |= M_BCAST; 1941 1942 if_output_lock(ifp, ifp, m, &sa, NULL); 1943 } 1944 1945 /* 1946 * RARP for the ip address of the specified interface, but also 1947 * save the ip address of the server that sent the answer. 1948 * Timeout if no response is received. 1949 */ 1950 int 1951 revarpwhoarewe(struct ifnet *ifp, struct in_addr *serv_in, 1952 struct in_addr *clnt_in) 1953 { 1954 int result, count = 20; 1955 1956 myip_initialized = 0; 1957 myip_ifp = ifp; 1958 1959 revarp_in_progress = 1; 1960 while (count--) { 1961 revarprequest(ifp); 1962 result = tsleep((void *)&myip, PSOCK, "revarp", hz/2); 1963 if (result != EWOULDBLOCK) 1964 break; 1965 } 1966 revarp_in_progress = 0; 1967 1968 if (!myip_initialized) 1969 return ENETUNREACH; 1970 1971 memcpy(serv_in, &srv_ip, sizeof(*serv_in)); 1972 memcpy(clnt_in, &myip, sizeof(*clnt_in)); 1973 return 0; 1974 } 1975 1976 void 1977 arp_stat_add(int type, uint64_t count) 1978 { 1979 ARP_STATADD(type, count); 1980 } 1981 1982 static int 1983 sysctl_net_inet_arp_stats(SYSCTLFN_ARGS) 1984 { 1985 1986 return NETSTAT_SYSCTL(arpstat_percpu, ARP_NSTATS); 1987 } 1988 1989 static void 1990 sysctl_net_inet_arp_setup(struct sysctllog **clog) 1991 { 1992 const struct sysctlnode *node; 1993 1994 sysctl_createv(clog, 0, NULL, NULL, 1995 CTLFLAG_PERMANENT, 1996 CTLTYPE_NODE, "inet", NULL, 1997 NULL, 0, NULL, 0, 1998 CTL_NET, PF_INET, CTL_EOL); 1999 sysctl_createv(clog, 0, NULL, &node, 2000 CTLFLAG_PERMANENT, 2001 CTLTYPE_NODE, "arp", 2002 SYSCTL_DESCR("Address Resolution Protocol"), 2003 NULL, 0, NULL, 0, 2004 CTL_NET, PF_INET, CTL_CREATE, CTL_EOL); 2005 2006 sysctl_createv(clog, 0, NULL, NULL, 2007 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2008 CTLTYPE_INT, "nd_delay", 2009 SYSCTL_DESCR("First probe delay time"), 2010 NULL, 0, &arp_nd_domain.nd_delay, 0, 2011 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2012 sysctl_createv(clog, 0, NULL, NULL, 2013 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2014 CTLTYPE_INT, "nd_bmaxtries", 2015 SYSCTL_DESCR("Number of broadcast discovery attempts"), 2016 NULL, 0, &arp_nd_domain.nd_mmaxtries, 0, 2017 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2018 sysctl_createv(clog, 0, NULL, NULL, 2019 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2020 CTLTYPE_INT, "nd_umaxtries", 2021 SYSCTL_DESCR("Number of unicast discovery attempts"), 2022 NULL, 0, &arp_nd_domain.nd_umaxtries, 0, 2023 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2024 sysctl_createv(clog, 0, NULL, NULL, 2025 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2026 CTLTYPE_INT, "nd_reachable", 2027 SYSCTL_DESCR("Reachable time"), 2028 NULL, 0, &arp_reachable, 0, 2029 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2030 sysctl_createv(clog, 0, NULL, NULL, 2031 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2032 CTLTYPE_INT, "nd_retrans", 2033 SYSCTL_DESCR("Retransmission time"), 2034 NULL, 0, &arp_retrans, 0, 2035 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2036 sysctl_createv(clog, 0, NULL, NULL, 2037 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2038 CTLTYPE_INT, "nd_nud", 2039 SYSCTL_DESCR("Perform neighbour unreachability detection"), 2040 NULL, 0, &arp_perform_nud, 0, 2041 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2042 sysctl_createv(clog, 0, NULL, NULL, 2043 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2044 CTLTYPE_INT, "nd_maxnudhint", 2045 SYSCTL_DESCR("Maximum neighbor unreachable hint count"), 2046 NULL, 0, &arp_nd_domain.nd_maxnudhint, 0, 2047 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2048 sysctl_createv(clog, 0, NULL, NULL, 2049 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2050 CTLTYPE_INT, "maxqueuelen", 2051 SYSCTL_DESCR("max packet queue len for a unresolved ARP"), 2052 NULL, 1, &arp_nd_domain.nd_maxqueuelen, 0, 2053 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2054 2055 sysctl_createv(clog, 0, NULL, NULL, 2056 CTLFLAG_PERMANENT, 2057 CTLTYPE_STRUCT, "stats", 2058 SYSCTL_DESCR("ARP statistics"), 2059 sysctl_net_inet_arp_stats, 0, NULL, 0, 2060 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2061 2062 sysctl_createv(clog, 0, NULL, NULL, 2063 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2064 CTLTYPE_INT, "log_movements", 2065 SYSCTL_DESCR("log ARP replies from MACs different than" 2066 " the one in the cache"), 2067 NULL, 0, &log_movements, 0, 2068 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2069 2070 sysctl_createv(clog, 0, NULL, NULL, 2071 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2072 CTLTYPE_INT, "log_permanent_modify", 2073 SYSCTL_DESCR("log ARP replies from MACs different than" 2074 " the one in the permanent arp entry"), 2075 NULL, 0, &log_permanent_modify, 0, 2076 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2077 2078 sysctl_createv(clog, 0, NULL, NULL, 2079 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2080 CTLTYPE_INT, "log_wrong_iface", 2081 SYSCTL_DESCR("log ARP packets arriving on the wrong" 2082 " interface"), 2083 NULL, 0, &log_wrong_iface, 0, 2084 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2085 2086 sysctl_createv(clog, 0, NULL, NULL, 2087 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2088 CTLTYPE_INT, "debug", 2089 SYSCTL_DESCR("Enable ARP DAD debug output"), 2090 NULL, 0, &arp_debug, 0, 2091 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2092 } 2093 2094 #endif /* INET */ 2095
Indexes created Tue Nov 10 00:26:44 UTC 2026