if_arp.c revision 1.290
1 /* $NetBSD: if_arp.c,v 1.290 2020/01/19 20:00:37 thorpej 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 1.290 2020/01/19 20:00:37 thorpej 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/route.h> 112 #include <net/net_stats.h> 113 114 #include <netinet/in.h> 115 #include <netinet/in_systm.h> 116 #include <netinet/in_var.h> 117 #include <netinet/ip.h> 118 #include <netinet/if_inarp.h> 119 120 #include "arcnet.h" 121 #if NARCNET > 0 122 #include <net/if_arc.h> 123 #endif 124 #include "fddi.h" 125 #if NFDDI > 0 126 #include <net/if_fddi.h> 127 #endif 128 #include "carp.h" 129 #if NCARP > 0 130 #include <netinet/ip_carp.h> 131 #endif 132 133 /* 134 * ARP trailer negotiation. Trailer protocol is not IP specific, 135 * but ARP request/response use IP addresses. 136 */ 137 #define ETHERTYPE_IPTRAILERS ETHERTYPE_TRAIL 138 139 /* timer values */ 140 static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */ 141 static int arpt_down = 20; /* once declared down, don't send for 20 secs */ 142 static int arp_maxhold = 1; /* number of packets to hold per ARP entry */ 143 #define rt_expire rt_rmx.rmx_expire 144 #define rt_pksent rt_rmx.rmx_pksent 145 146 int ip_dad_count = PROBE_NUM; 147 #ifdef ARP_DEBUG 148 int arp_debug = 1; 149 #else 150 int arp_debug = 0; 151 #endif 152 153 static void arp_init(void); 154 static void arp_dad_init(void); 155 156 static void arprequest(struct ifnet *, 157 const struct in_addr *, const struct in_addr *, 158 const uint8_t *); 159 static void arpannounce1(struct ifaddr *); 160 static struct sockaddr *arp_setgate(struct rtentry *, struct sockaddr *, 161 const struct sockaddr *); 162 static void arptimer(void *); 163 static void arp_settimer(struct llentry *, int); 164 static struct llentry *arplookup(struct ifnet *, 165 const struct in_addr *, const struct sockaddr *, int); 166 static struct llentry *arpcreate(struct ifnet *, 167 const struct in_addr *, const struct sockaddr *, int); 168 static void in_arpinput(struct mbuf *); 169 static void in_revarpinput(struct mbuf *); 170 static void revarprequest(struct ifnet *); 171 172 static void arp_drainstub(void); 173 174 struct dadq; 175 static void arp_dad_timer(struct dadq *); 176 static void arp_dad_start(struct ifaddr *); 177 static void arp_dad_stop(struct ifaddr *); 178 static void arp_dad_duplicated(struct ifaddr *, const struct sockaddr_dl *); 179 180 static void arp_init_llentry(struct ifnet *, struct llentry *); 181 182 struct ifqueue arpintrq = { 183 .ifq_head = NULL, 184 .ifq_tail = NULL, 185 .ifq_len = 0, 186 .ifq_maxlen = 50, 187 .ifq_drops = 0, 188 }; 189 static int arp_maxtries = 5; 190 static int useloopback = 1; /* use loopback interface for local traffic */ 191 192 static percpu_t *arpstat_percpu; 193 194 #define ARP_STAT_GETREF() _NET_STAT_GETREF(arpstat_percpu) 195 #define ARP_STAT_PUTREF() _NET_STAT_PUTREF(arpstat_percpu) 196 197 #define ARP_STATINC(x) _NET_STATINC(arpstat_percpu, x) 198 #define ARP_STATADD(x, v) _NET_STATADD(arpstat_percpu, x, v) 199 200 /* revarp state */ 201 static struct in_addr myip, srv_ip; 202 static int myip_initialized = 0; 203 static int revarp_in_progress = 0; 204 static struct ifnet *myip_ifp = NULL; 205 206 static int arp_drainwanted; 207 208 static int log_movements = 0; 209 static int log_permanent_modify = 1; 210 static int log_wrong_iface = 1; 211 212 DOMAIN_DEFINE(arpdomain); /* forward declare and add to link set */ 213 214 static void 215 arp_fasttimo(void) 216 { 217 if (arp_drainwanted) { 218 arp_drain(); 219 arp_drainwanted = 0; 220 } 221 } 222 223 static const struct protosw arpsw[] = { 224 { 225 .pr_type = 0, 226 .pr_domain = &arpdomain, 227 .pr_protocol = 0, 228 .pr_flags = 0, 229 .pr_input = 0, 230 .pr_ctlinput = 0, 231 .pr_ctloutput = 0, 232 .pr_usrreqs = 0, 233 .pr_init = arp_init, 234 .pr_fasttimo = arp_fasttimo, 235 .pr_slowtimo = 0, 236 .pr_drain = arp_drainstub, 237 } 238 }; 239 240 struct domain arpdomain = { 241 .dom_family = PF_ARP, 242 .dom_name = "arp", 243 .dom_protosw = arpsw, 244 .dom_protoswNPROTOSW = &arpsw[__arraycount(arpsw)], 245 #ifdef MBUFTRACE 246 .dom_mowner = MOWNER_INIT("internet", "arp"), 247 #endif 248 }; 249 250 static void sysctl_net_inet_arp_setup(struct sysctllog **); 251 252 void 253 arp_init(void) 254 { 255 256 sysctl_net_inet_arp_setup(NULL); 257 arpstat_percpu = percpu_alloc(sizeof(uint64_t) * ARP_NSTATS); 258 IFQ_LOCK_INIT(&arpintrq); 259 260 #ifdef MBUFTRACE 261 MOWNER_ATTACH(&arpdomain.dom_mowner); 262 #endif 263 264 arp_dad_init(); 265 } 266 267 static void 268 arp_drainstub(void) 269 { 270 arp_drainwanted = 1; 271 } 272 273 /* 274 * ARP protocol drain routine. Called when memory is in short supply. 275 * Called at splvm(); don't acquire softnet_lock as can be called from 276 * hardware interrupt handlers. 277 */ 278 void 279 arp_drain(void) 280 { 281 282 lltable_drain(AF_INET); 283 } 284 285 static void 286 arptimer(void *arg) 287 { 288 struct llentry *lle = arg; 289 struct ifnet *ifp; 290 291 KASSERT((lle->la_flags & LLE_STATIC) == 0); 292 293 LLE_WLOCK(lle); 294 295 /* 296 * This shortcut is required to avoid trying to touch ifp that may be 297 * being destroyed. 298 */ 299 if ((lle->la_flags & LLE_LINKED) == 0) { 300 LLE_FREE_LOCKED(lle); 301 return; 302 } 303 304 ifp = lle->lle_tbl->llt_ifp; 305 306 /* XXX: LOR avoidance. We still have ref on lle. */ 307 LLE_WUNLOCK(lle); 308 309 IF_AFDATA_LOCK(ifp); 310 LLE_WLOCK(lle); 311 312 /* Guard against race with other llentry_free(). */ 313 if (lle->la_flags & LLE_LINKED) { 314 size_t pkts_dropped; 315 316 if (lle->la_flags & LLE_VALID) { 317 struct in_addr *in; 318 struct sockaddr_in sin; 319 const char *lladdr; 320 321 in = &lle->r_l3addr.addr4; 322 sockaddr_in_init(&sin, in, 0); 323 lladdr = (const char *)&lle->ll_addr; 324 rt_clonedmsg(RTM_DELETE, sintosa(&sin), lladdr, ifp); 325 } 326 327 LLE_REMREF(lle); 328 pkts_dropped = llentry_free(lle); 329 ARP_STATADD(ARP_STAT_DFRDROPPED, pkts_dropped); 330 ARP_STATADD(ARP_STAT_DFRTOTAL, pkts_dropped); 331 } else { 332 LLE_FREE_LOCKED(lle); 333 } 334 335 IF_AFDATA_UNLOCK(ifp); 336 } 337 338 static void 339 arp_settimer(struct llentry *la, int sec) 340 { 341 342 LLE_WLOCK_ASSERT(la); 343 KASSERT((la->la_flags & LLE_STATIC) == 0); 344 345 /* 346 * We have to take care of a reference leak which occurs if 347 * callout_reset overwrites a pending callout schedule. Unfortunately 348 * we don't have a mean to know the overwrite, so we need to know it 349 * using callout_stop. We need to call callout_pending first to exclude 350 * the case that the callout has never been scheduled. 351 */ 352 if (callout_pending(&la->la_timer)) { 353 bool expired = callout_stop(&la->la_timer); 354 if (!expired) 355 /* A pending callout schedule is canceled. */ 356 LLE_REMREF(la); 357 } 358 LLE_ADDREF(la); 359 callout_reset(&la->la_timer, hz * sec, arptimer, la); 360 } 361 362 /* 363 * We set the gateway for RTF_CLONING routes to a "prototype" 364 * link-layer sockaddr whose interface type (if_type) and interface 365 * index (if_index) fields are prepared. 366 */ 367 static struct sockaddr * 368 arp_setgate(struct rtentry *rt, struct sockaddr *gate, 369 const struct sockaddr *netmask) 370 { 371 const struct ifnet *ifp = rt->rt_ifp; 372 uint8_t namelen = strlen(ifp->if_xname); 373 uint8_t addrlen = ifp->if_addrlen; 374 375 /* 376 * XXX: If this is a manually added route to interface 377 * such as older version of routed or gated might provide, 378 * restore cloning bit. 379 */ 380 if ((rt->rt_flags & RTF_HOST) == 0 && netmask != NULL && 381 satocsin(netmask)->sin_addr.s_addr != 0xffffffff) 382 rt->rt_flags |= RTF_CONNECTED; 383 384 if ((rt->rt_flags & (RTF_CONNECTED | RTF_LOCAL))) { 385 union { 386 struct sockaddr sa; 387 struct sockaddr_storage ss; 388 struct sockaddr_dl sdl; 389 } u; 390 /* 391 * Case 1: This route should come from a route to iface. 392 */ 393 sockaddr_dl_init(&u.sdl, sizeof(u.ss), 394 ifp->if_index, ifp->if_type, NULL, namelen, NULL, addrlen); 395 rt_setgate(rt, &u.sa); 396 gate = rt->rt_gateway; 397 } 398 return gate; 399 } 400 401 static void 402 arp_init_llentry(struct ifnet *ifp, struct llentry *lle) 403 { 404 405 switch (ifp->if_type) { 406 default: 407 /* Nothing. */ 408 break; 409 } 410 } 411 412 /* 413 * Parallel to llc_rtrequest. 414 */ 415 void 416 arp_rtrequest(int req, struct rtentry *rt, const struct rt_addrinfo *info) 417 { 418 struct sockaddr *gate = rt->rt_gateway; 419 struct in_ifaddr *ia; 420 struct ifaddr *ifa; 421 struct ifnet *ifp = rt->rt_ifp; 422 int bound; 423 int s; 424 425 if (req == RTM_LLINFO_UPD) { 426 if ((ifa = info->rti_ifa) != NULL) 427 arpannounce1(ifa); 428 return; 429 } 430 431 if ((rt->rt_flags & RTF_GATEWAY) != 0) { 432 if (req != RTM_ADD) 433 return; 434 435 /* 436 * linklayers with particular link MTU limitation. 437 */ 438 switch(ifp->if_type) { 439 #if NFDDI > 0 440 case IFT_FDDI: 441 if (ifp->if_mtu > FDDIIPMTU) 442 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 443 break; 444 #endif 445 #if NARCNET > 0 446 case IFT_ARCNET: 447 { 448 int arcipifmtu; 449 450 if (ifp->if_flags & IFF_LINK0) 451 arcipifmtu = arc_ipmtu; 452 else 453 arcipifmtu = ARCMTU; 454 if (ifp->if_mtu > arcipifmtu) 455 rt->rt_rmx.rmx_mtu = arcipifmtu; 456 break; 457 } 458 #endif 459 } 460 return; 461 } 462 463 switch (req) { 464 case RTM_SETGATE: 465 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 466 break; 467 case RTM_ADD: 468 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 469 if (gate == NULL) { 470 log(LOG_ERR, "%s: arp_setgate failed\n", __func__); 471 break; 472 } 473 if ((rt->rt_flags & RTF_CONNECTED) || 474 (rt->rt_flags & RTF_LOCAL)) { 475 /* 476 * Give this route an expiration time, even though 477 * it's a "permanent" route, so that routes cloned 478 * from it do not need their expiration time set. 479 */ 480 KASSERT(time_uptime != 0); 481 rt->rt_expire = time_uptime; 482 /* 483 * linklayers with particular link MTU limitation. 484 */ 485 switch (ifp->if_type) { 486 #if NFDDI > 0 487 case IFT_FDDI: 488 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 489 (rt->rt_rmx.rmx_mtu > FDDIIPMTU || 490 (rt->rt_rmx.rmx_mtu == 0 && 491 ifp->if_mtu > FDDIIPMTU))) 492 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 493 break; 494 #endif 495 #if NARCNET > 0 496 case IFT_ARCNET: 497 { 498 int arcipifmtu; 499 if (ifp->if_flags & IFF_LINK0) 500 arcipifmtu = arc_ipmtu; 501 else 502 arcipifmtu = ARCMTU; 503 504 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 505 (rt->rt_rmx.rmx_mtu > arcipifmtu || 506 (rt->rt_rmx.rmx_mtu == 0 && 507 ifp->if_mtu > arcipifmtu))) 508 rt->rt_rmx.rmx_mtu = arcipifmtu; 509 break; 510 } 511 #endif 512 } 513 if (rt->rt_flags & RTF_CONNECTED) 514 break; 515 } 516 517 bound = curlwp_bind(); 518 /* Announce a new entry if requested. */ 519 if (rt->rt_flags & RTF_ANNOUNCE) { 520 struct psref psref; 521 ia = in_get_ia_on_iface_psref( 522 satocsin(rt_getkey(rt))->sin_addr, ifp, &psref); 523 if (ia != NULL) { 524 arpannounce(ifp, &ia->ia_ifa, 525 CLLADDR(satocsdl(gate))); 526 ia4_release(ia, &psref); 527 } 528 } 529 530 if (gate->sa_family != AF_LINK || 531 gate->sa_len < sockaddr_dl_measure(0, ifp->if_addrlen)) { 532 log(LOG_DEBUG, "%s: bad gateway value\n", __func__); 533 goto out; 534 } 535 536 satosdl(gate)->sdl_type = ifp->if_type; 537 satosdl(gate)->sdl_index = ifp->if_index; 538 539 /* 540 * If the route is for a broadcast address mark it as such. 541 * This way we can avoid an expensive call to in_broadcast() 542 * in ip_output() most of the time (because the route passed 543 * to ip_output() is almost always a host route). 544 */ 545 if (rt->rt_flags & RTF_HOST && 546 !(rt->rt_flags & RTF_BROADCAST) && 547 in_broadcast(satocsin(rt_getkey(rt))->sin_addr, rt->rt_ifp)) 548 rt->rt_flags |= RTF_BROADCAST; 549 /* There is little point in resolving the broadcast address */ 550 if (rt->rt_flags & RTF_BROADCAST) 551 goto out; 552 553 /* 554 * When called from rt_ifa_addlocal, we cannot depend on that 555 * the address (rt_getkey(rt)) exits in the address list of the 556 * interface. So check RTF_LOCAL instead. 557 */ 558 if (rt->rt_flags & RTF_LOCAL) { 559 rt->rt_expire = 0; 560 if (useloopback) { 561 rt->rt_ifp = lo0ifp; 562 rt->rt_rmx.rmx_mtu = 0; 563 } 564 goto out; 565 } 566 567 s = pserialize_read_enter(); 568 ia = in_get_ia_on_iface(satocsin(rt_getkey(rt))->sin_addr, ifp); 569 if (ia == NULL) { 570 pserialize_read_exit(s); 571 goto out; 572 } 573 574 rt->rt_expire = 0; 575 if (useloopback) { 576 rt->rt_ifp = lo0ifp; 577 rt->rt_rmx.rmx_mtu = 0; 578 } 579 rt->rt_flags |= RTF_LOCAL; 580 581 if (ISSET(info->rti_flags, RTF_DONTCHANGEIFA)) { 582 pserialize_read_exit(s); 583 goto out; 584 } 585 /* 586 * make sure to set rt->rt_ifa to the interface 587 * address we are using, otherwise we will have trouble 588 * with source address selection. 589 */ 590 ifa = &ia->ia_ifa; 591 if (ifa != rt->rt_ifa) 592 /* Assume it doesn't sleep */ 593 rt_replace_ifa(rt, ifa); 594 pserialize_read_exit(s); 595 out: 596 curlwp_bindx(bound); 597 break; 598 } 599 } 600 601 /* 602 * Broadcast an ARP request. Caller specifies: 603 * - arp header source ip address 604 * - arp header target ip address 605 * - arp header source ethernet address 606 */ 607 static void 608 arprequest(struct ifnet *ifp, 609 const struct in_addr *sip, const struct in_addr *tip, 610 const uint8_t *enaddr) 611 { 612 struct mbuf *m; 613 struct arphdr *ah; 614 struct sockaddr sa; 615 uint64_t *arps; 616 617 KASSERT(sip != NULL); 618 KASSERT(tip != NULL); 619 KASSERT(enaddr != NULL); 620 621 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 622 return; 623 MCLAIM(m, &arpdomain.dom_mowner); 624 switch (ifp->if_type) { 625 case IFT_IEEE1394: 626 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 627 ifp->if_addrlen; 628 break; 629 default: 630 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 631 2 * ifp->if_addrlen; 632 break; 633 } 634 m->m_pkthdr.len = m->m_len; 635 m_align(m, m->m_len); 636 ah = mtod(m, struct arphdr *); 637 memset(ah, 0, m->m_len); 638 switch (ifp->if_type) { 639 case IFT_IEEE1394: /* RFC2734 */ 640 /* fill it now for ar_tpa computation */ 641 ah->ar_hrd = htons(ARPHRD_IEEE1394); 642 break; 643 default: 644 /* ifp->if_output will fill ar_hrd */ 645 break; 646 } 647 ah->ar_pro = htons(ETHERTYPE_IP); 648 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 649 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 650 ah->ar_op = htons(ARPOP_REQUEST); 651 memcpy(ar_sha(ah), enaddr, ah->ar_hln); 652 memcpy(ar_spa(ah), sip, ah->ar_pln); 653 memcpy(ar_tpa(ah), tip, ah->ar_pln); 654 sa.sa_family = AF_ARP; 655 sa.sa_len = 2; 656 m->m_flags |= M_BCAST; 657 arps = ARP_STAT_GETREF(); 658 arps[ARP_STAT_SNDTOTAL]++; 659 arps[ARP_STAT_SENDREQUEST]++; 660 ARP_STAT_PUTREF(); 661 if_output_lock(ifp, ifp, m, &sa, NULL); 662 } 663 664 void 665 arpannounce(struct ifnet *ifp, struct ifaddr *ifa, const uint8_t *enaddr) 666 { 667 struct in_ifaddr *ia = ifatoia(ifa); 668 struct in_addr *ip = &IA_SIN(ifa)->sin_addr; 669 670 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) { 671 ARPLOG(LOG_DEBUG, "%s not ready\n", ARPLOGADDR(ip)); 672 return; 673 } 674 arprequest(ifp, ip, ip, enaddr); 675 } 676 677 static void 678 arpannounce1(struct ifaddr *ifa) 679 { 680 681 arpannounce(ifa->ifa_ifp, ifa, CLLADDR(ifa->ifa_ifp->if_sadl)); 682 } 683 684 /* 685 * Resolve an IP address into an ethernet address. If success, desten is 686 * filled in. If there is no entry in arptab, set one up and broadcast a 687 * request for the IP address. Hold onto this mbuf and resend it once the 688 * address is finally resolved. 689 * 690 * A return value of 0 indicates that desten has been filled in and the packet 691 * should be sent normally; a return value of EWOULDBLOCK indicates that the 692 * packet has been held pending resolution. Any other value indicates an 693 * error. 694 */ 695 int 696 arpresolve(struct ifnet *ifp, const struct rtentry *rt, struct mbuf *m, 697 const struct sockaddr *dst, void *desten, size_t destlen) 698 { 699 struct llentry *la; 700 const char *create_lookup; 701 bool renew; 702 int error; 703 struct ifnet *origifp = ifp; 704 705 #if NCARP > 0 706 if (rt != NULL && rt->rt_ifp->if_type == IFT_CARP) 707 ifp = rt->rt_ifp; 708 #endif 709 710 KASSERT(m != NULL); 711 712 la = arplookup(ifp, NULL, dst, 0); 713 if (la == NULL) 714 goto notfound; 715 716 if ((la->la_flags & LLE_VALID) && 717 ((la->la_flags & LLE_STATIC) || la->la_expire > time_uptime)) { 718 KASSERT(destlen >= ifp->if_addrlen); 719 memcpy(desten, &la->ll_addr, ifp->if_addrlen); 720 LLE_RUNLOCK(la); 721 return 0; 722 } 723 724 notfound: 725 if (ifp->if_flags & IFF_NOARP) { 726 if (la != NULL) 727 LLE_RUNLOCK(la); 728 error = ENOTSUP; 729 goto bad; 730 } 731 732 if (la == NULL) { 733 struct rtentry *_rt; 734 735 create_lookup = "create"; 736 _rt = rtalloc1(dst, 0); 737 IF_AFDATA_WLOCK(ifp); 738 la = lla_create(LLTABLE(ifp), LLE_EXCLUSIVE, dst, _rt); 739 IF_AFDATA_WUNLOCK(ifp); 740 if (_rt != NULL) 741 rt_unref(_rt); 742 if (la == NULL) 743 ARP_STATINC(ARP_STAT_ALLOCFAIL); 744 else 745 arp_init_llentry(ifp, la); 746 } else if (LLE_TRY_UPGRADE(la) == 0) { 747 create_lookup = "lookup"; 748 LLE_RUNLOCK(la); 749 IF_AFDATA_RLOCK(ifp); 750 la = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst); 751 IF_AFDATA_RUNLOCK(ifp); 752 } 753 754 error = EINVAL; 755 if (la == NULL) { 756 log(LOG_DEBUG, 757 "%s: failed to %s llentry for %s on %s\n", 758 __func__, create_lookup, inet_ntoa(satocsin(dst)->sin_addr), 759 ifp->if_xname); 760 goto bad; 761 } 762 763 if ((la->la_flags & LLE_VALID) && 764 ((la->la_flags & LLE_STATIC) || la->la_expire > time_uptime)) 765 { 766 KASSERT(destlen >= ifp->if_addrlen); 767 memcpy(desten, &la->ll_addr, ifp->if_addrlen); 768 renew = false; 769 /* 770 * If entry has an expiry time and it is approaching, 771 * see if we need to send an ARP request within this 772 * arpt_down interval. 773 */ 774 if (!(la->la_flags & LLE_STATIC) && 775 time_uptime + la->la_preempt > la->la_expire) 776 { 777 renew = true; 778 la->la_preempt--; 779 } 780 781 LLE_WUNLOCK(la); 782 783 if (renew) { 784 const uint8_t *enaddr = CLLADDR(ifp->if_sadl); 785 arprequest(origifp, 786 &satocsin(rt->rt_ifa->ifa_addr)->sin_addr, 787 &satocsin(dst)->sin_addr, enaddr); 788 } 789 790 return 0; 791 } 792 793 if (la->la_flags & LLE_STATIC) { /* should not happen! */ 794 LLE_RUNLOCK(la); 795 log(LOG_DEBUG, "%s: ouch, empty static llinfo for %s\n", 796 __func__, inet_ntoa(satocsin(dst)->sin_addr)); 797 error = EINVAL; 798 goto bad; 799 } 800 801 renew = (la->la_asked == 0 || la->la_expire != time_uptime); 802 803 /* 804 * There is an arptab entry, but no ethernet address 805 * response yet. Add the mbuf to the list, dropping 806 * the oldest packet if we have exceeded the system 807 * setting. 808 */ 809 LLE_WLOCK_ASSERT(la); 810 if (la->la_numheld >= arp_maxhold) { 811 if (la->la_hold != NULL) { 812 struct mbuf *next = la->la_hold->m_nextpkt; 813 m_freem(la->la_hold); 814 la->la_hold = next; 815 la->la_numheld--; 816 ARP_STATINC(ARP_STAT_DFRDROPPED); 817 ARP_STATINC(ARP_STAT_DFRTOTAL); 818 } 819 } 820 if (la->la_hold != NULL) { 821 struct mbuf *curr = la->la_hold; 822 while (curr->m_nextpkt != NULL) 823 curr = curr->m_nextpkt; 824 curr->m_nextpkt = m; 825 } else 826 la->la_hold = m; 827 la->la_numheld++; 828 if (!renew) 829 LLE_DOWNGRADE(la); 830 831 /* 832 * Return EWOULDBLOCK if we have tried less than arp_maxtries. It 833 * will be masked by ether_output(). Return EHOSTDOWN/EHOSTUNREACH 834 * if we have already sent arp_maxtries ARP requests. Retransmit the 835 * ARP request, but not faster than one request per second. 836 */ 837 if (la->la_asked < arp_maxtries) 838 error = EWOULDBLOCK; /* First request. */ 839 else 840 error = (rt != NULL && rt->rt_flags & RTF_GATEWAY) ? 841 EHOSTUNREACH : EHOSTDOWN; 842 843 if (renew) { 844 const uint8_t *enaddr = CLLADDR(ifp->if_sadl); 845 struct sockaddr_in sin; 846 847 la->la_expire = time_uptime; 848 arp_settimer(la, arpt_down); 849 la->la_asked++; 850 851 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 852 if (error != EWOULDBLOCK) 853 rt_clonedmsg(RTM_MISS, sintosa(&sin), NULL, ifp); 854 855 LLE_WUNLOCK(la); 856 857 if (rt != NULL) { 858 arprequest(origifp, 859 &satocsin(rt->rt_ifa->ifa_addr)->sin_addr, 860 &satocsin(dst)->sin_addr, enaddr); 861 } else { 862 struct rtentry *_rt; 863 864 /* XXX */ 865 _rt = rtalloc1((struct sockaddr *)&sin, 0); 866 if (_rt == NULL) 867 goto bad; 868 arprequest(origifp, 869 &satocsin(_rt->rt_ifa->ifa_addr)->sin_addr, 870 &satocsin(dst)->sin_addr, enaddr); 871 rt_unref(_rt); 872 } 873 return error; 874 } 875 876 LLE_RUNLOCK(la); 877 return error; 878 879 bad: 880 m_freem(m); 881 return error; 882 } 883 884 /* 885 * Common length and type checks are done here, 886 * then the protocol-specific routine is called. 887 */ 888 void 889 arpintr(void) 890 { 891 struct mbuf *m; 892 struct arphdr *ar; 893 int s; 894 int arplen; 895 896 SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE(); 897 for (;;) { 898 struct ifnet *rcvif; 899 900 IFQ_LOCK(&arpintrq); 901 IF_DEQUEUE(&arpintrq, m); 902 IFQ_UNLOCK(&arpintrq); 903 if (m == NULL) 904 goto out; 905 if ((m->m_flags & M_PKTHDR) == 0) 906 panic("arpintr"); 907 908 MCLAIM(m, &arpdomain.dom_mowner); 909 ARP_STATINC(ARP_STAT_RCVTOTAL); 910 911 arplen = sizeof(struct arphdr); 912 if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL) 913 goto badlen; 914 ar = mtod(m, struct arphdr *); 915 916 rcvif = m_get_rcvif(m, &s); 917 if (__predict_false(rcvif == NULL)) { 918 ARP_STATINC(ARP_STAT_RCVNOINT); 919 goto free; 920 } 921 922 /* 923 * We don't want non-IEEE1394 ARP packets on IEEE1394 924 * interfaces, and vice versa. Our life depends on that. 925 */ 926 switch (rcvif->if_type) { 927 case IFT_IEEE1394: 928 if (ntohs(ar->ar_hrd) != ARPHRD_IEEE1394) { 929 m_put_rcvif(rcvif, &s); 930 ARP_STATINC(ARP_STAT_RCVBADPROTO); 931 goto free; 932 } 933 934 arplen = sizeof(struct arphdr) + 935 ar->ar_hln + 2 * ar->ar_pln; 936 break; 937 default: 938 if (ntohs(ar->ar_hrd) == ARPHRD_IEEE1394) { 939 m_put_rcvif(rcvif, &s); 940 ARP_STATINC(ARP_STAT_RCVBADPROTO); 941 goto free; 942 } 943 944 arplen = sizeof(struct arphdr) + 945 2 * ar->ar_hln + 2 * ar->ar_pln; 946 break; 947 } 948 949 m_put_rcvif(rcvif, &s); 950 951 if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL) 952 goto badlen; 953 ar = mtod(m, struct arphdr *); 954 955 switch (ntohs(ar->ar_pro)) { 956 case ETHERTYPE_IP: 957 case ETHERTYPE_IPTRAILERS: 958 in_arpinput(m); 959 continue; 960 default: 961 ARP_STATINC(ARP_STAT_RCVBADPROTO); 962 goto free; 963 } 964 965 badlen: 966 ARP_STATINC(ARP_STAT_RCVBADLEN); 967 free: 968 m_freem(m); 969 } 970 971 out: 972 SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 973 return; /* XXX gcc */ 974 } 975 976 /* 977 * ARP for Internet protocols on 10 Mb/s Ethernet. Algorithm is that given in 978 * RFC 826. In addition, a sanity check is performed on the sender protocol 979 * address, to catch impersonators. 980 * 981 * We no longer handle negotiations for use of trailer protocol: formerly, ARP 982 * replied for protocol type ETHERTYPE_TRAIL sent along with IP replies if we 983 * wanted trailers sent to us, and also sent them in response to IP replies. 984 * This allowed either end to announce the desire to receive trailer packets. 985 * 986 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, but 987 * formerly didn't normally send requests. 988 */ 989 static void 990 in_arpinput(struct mbuf *m) 991 { 992 struct arphdr *ah; 993 struct ifnet *ifp, *rcvif = NULL; 994 struct llentry *la = NULL; 995 struct in_ifaddr *ia = NULL; 996 #if NBRIDGE > 0 997 struct in_ifaddr *bridge_ia = NULL; 998 #endif 999 #if NCARP > 0 1000 uint32_t count = 0, index = 0; 1001 #endif 1002 struct sockaddr sa; 1003 struct in_addr isaddr, itaddr, myaddr; 1004 int op, rt_cmd; 1005 void *tha; 1006 uint64_t *arps; 1007 struct psref psref, psref_ia; 1008 int s; 1009 char ipbuf[INET_ADDRSTRLEN]; 1010 bool do_dad; 1011 1012 if (__predict_false(m_makewritable(&m, 0, m->m_pkthdr.len, M_DONTWAIT))) 1013 goto out; 1014 ah = mtod(m, struct arphdr *); 1015 op = ntohs(ah->ar_op); 1016 1017 if (ah->ar_pln != sizeof(struct in_addr)) 1018 goto out; 1019 1020 ifp = if_get_bylla(ar_sha(ah), ah->ar_hln, &psref); 1021 if (ifp) { 1022 /* it's from me, ignore it. */ 1023 if_put(ifp, &psref); 1024 ARP_STATINC(ARP_STAT_RCVLOCALSHA); 1025 goto out; 1026 } 1027 1028 rcvif = ifp = m_get_rcvif_psref(m, &psref); 1029 if (__predict_false(rcvif == NULL)) 1030 goto out; 1031 if (rcvif->if_flags & IFF_NOARP) 1032 goto out; 1033 1034 memcpy(&isaddr, ar_spa(ah), sizeof(isaddr)); 1035 memcpy(&itaddr, ar_tpa(ah), sizeof(itaddr)); 1036 1037 if (m->m_flags & (M_BCAST|M_MCAST)) 1038 ARP_STATINC(ARP_STAT_RCVMCAST); 1039 1040 /* 1041 * Search for a matching interface address 1042 * or any address on the interface to use 1043 * as a dummy address in the rest of this function. 1044 * 1045 * If the target IP address is zero then try and find 1046 * the sender address for DAD. 1047 */ 1048 myaddr = in_nullhost(itaddr) ? isaddr : itaddr; 1049 s = pserialize_read_enter(); 1050 IN_ADDRHASH_READER_FOREACH(ia, myaddr.s_addr) { 1051 if (!in_hosteq(ia->ia_addr.sin_addr, myaddr)) 1052 continue; 1053 #if NCARP > 0 1054 if (ia->ia_ifp->if_type == IFT_CARP && 1055 ((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) == 1056 (IFF_UP|IFF_RUNNING))) { 1057 index++; 1058 /* XXX: ar_hln? */ 1059 if (ia->ia_ifp == rcvif && (ah->ar_hln >= 6) && 1060 carp_iamatch(ia, ar_sha(ah), 1061 &count, index)) { 1062 break; 1063 } 1064 } else 1065 #endif 1066 if (ia->ia_ifp == rcvif) 1067 break; 1068 #if NBRIDGE > 0 1069 /* 1070 * If the interface we received the packet on 1071 * is part of a bridge, check to see if we need 1072 * to "bridge" the packet to ourselves at this 1073 * layer. Note we still prefer a perfect match, 1074 * but allow this weaker match if necessary. 1075 */ 1076 if (rcvif->if_bridge != NULL && 1077 rcvif->if_bridge == ia->ia_ifp->if_bridge) 1078 bridge_ia = ia; 1079 #endif 1080 } 1081 1082 #if NBRIDGE > 0 1083 if (ia == NULL && bridge_ia != NULL) { 1084 ia = bridge_ia; 1085 m_put_rcvif_psref(rcvif, &psref); 1086 rcvif = NULL; 1087 /* FIXME */ 1088 ifp = bridge_ia->ia_ifp; 1089 } 1090 #endif 1091 if (ia != NULL) 1092 ia4_acquire(ia, &psref_ia); 1093 pserialize_read_exit(s); 1094 1095 if (ah->ar_hln != ifp->if_addrlen) { 1096 ARP_STATINC(ARP_STAT_RCVBADLEN); 1097 log(LOG_WARNING, 1098 "arp from %s: addr len: new %d, i/f %d (ignored)\n", 1099 IN_PRINT(ipbuf, &isaddr), ah->ar_hln, ifp->if_addrlen); 1100 goto out; 1101 } 1102 1103 /* Only do DaD if we have a matching address. */ 1104 do_dad = (ia != NULL); 1105 1106 if (ia == NULL) { 1107 ia = in_get_ia_on_iface_psref(isaddr, rcvif, &psref_ia); 1108 if (ia == NULL) { 1109 ia = in_get_ia_from_ifp_psref(ifp, &psref_ia); 1110 if (ia == NULL) { 1111 ARP_STATINC(ARP_STAT_RCVNOINT); 1112 goto out; 1113 } 1114 } 1115 } 1116 1117 myaddr = ia->ia_addr.sin_addr; 1118 1119 /* XXX checks for bridge case? */ 1120 if (!memcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 1121 ARP_STATINC(ARP_STAT_RCVBCASTSHA); 1122 log(LOG_ERR, 1123 "%s: arp: link address is broadcast for IP address %s!\n", 1124 ifp->if_xname, IN_PRINT(ipbuf, &isaddr)); 1125 goto out; 1126 } 1127 1128 /* 1129 * If the source IP address is zero, this is an RFC 5227 ARP probe 1130 */ 1131 if (in_nullhost(isaddr)) 1132 ARP_STATINC(ARP_STAT_RCVZEROSPA); 1133 else if (in_hosteq(isaddr, myaddr)) 1134 ARP_STATINC(ARP_STAT_RCVLOCALSPA); 1135 1136 if (in_nullhost(itaddr)) 1137 ARP_STATINC(ARP_STAT_RCVZEROTPA); 1138 1139 /* 1140 * DAD check, RFC 5227. 1141 * Collision on sender address is always a duplicate. 1142 * Collision on target address is only a duplicate 1143 * IF the sender address is the null host (ie a DAD probe) 1144 * AND the message was broadcast 1145 * AND our address is either tentative or duplicated 1146 * If it was unicast then it's a valid Unicast Poll from RFC 1122. 1147 */ 1148 if (do_dad && 1149 (in_hosteq(isaddr, myaddr) || 1150 (in_nullhost(isaddr) && in_hosteq(itaddr, myaddr) && 1151 m->m_flags & M_BCAST && 1152 ia->ia4_flags & (IN_IFF_TENTATIVE | IN_IFF_DUPLICATED)))) 1153 { 1154 struct sockaddr_dl sdl, *sdlp; 1155 1156 sdlp = sockaddr_dl_init(&sdl, sizeof(sdl), 1157 ifp->if_index, ifp->if_type, 1158 NULL, 0, ar_sha(ah), ah->ar_hln); 1159 arp_dad_duplicated((struct ifaddr *)ia, sdlp); 1160 goto out; 1161 } 1162 1163 /* 1164 * If the target IP address is zero, ignore the packet. 1165 * This prevents the code below from trying to answer 1166 * when we are using IP address zero (booting). 1167 */ 1168 if (in_nullhost(itaddr)) 1169 goto out; 1170 1171 if (in_nullhost(isaddr)) 1172 goto reply; 1173 1174 if (in_hosteq(itaddr, myaddr)) 1175 la = arpcreate(ifp, &isaddr, NULL, 1); 1176 else 1177 la = arplookup(ifp, &isaddr, NULL, 1); 1178 if (la == NULL) 1179 goto reply; 1180 1181 if ((la->la_flags & LLE_VALID) && 1182 memcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) 1183 { 1184 char llabuf[LLA_ADDRSTRLEN], *llastr; 1185 1186 llastr = lla_snprintf(llabuf, sizeof(llabuf), 1187 ar_sha(ah), ah->ar_hln); 1188 1189 if (la->la_flags & LLE_STATIC) { 1190 ARP_STATINC(ARP_STAT_RCVOVERPERM); 1191 if (!log_permanent_modify) 1192 goto out; 1193 log(LOG_INFO, 1194 "%s tried to overwrite permanent arp info" 1195 " for %s\n", llastr, IN_PRINT(ipbuf, &isaddr)); 1196 goto out; 1197 } else if (la->lle_tbl->llt_ifp != ifp) { 1198 /* XXX should not happen? */ 1199 ARP_STATINC(ARP_STAT_RCVOVERINT); 1200 if (!log_wrong_iface) 1201 goto out; 1202 log(LOG_INFO, 1203 "%s on %s tried to overwrite " 1204 "arp info for %s on %s\n", 1205 llastr, 1206 ifp->if_xname, IN_PRINT(ipbuf, &isaddr), 1207 la->lle_tbl->llt_ifp->if_xname); 1208 goto out; 1209 } else { 1210 ARP_STATINC(ARP_STAT_RCVOVER); 1211 if (log_movements) 1212 log(LOG_INFO, "arp info overwritten " 1213 "for %s by %s\n", 1214 IN_PRINT(ipbuf, &isaddr), llastr); 1215 } 1216 rt_cmd = RTM_CHANGE; 1217 } else 1218 rt_cmd = la->la_flags & LLE_VALID ? 0 : RTM_ADD; 1219 1220 KASSERT(ifp->if_sadl->sdl_alen == ifp->if_addrlen); 1221 1222 KASSERT(sizeof(la->ll_addr) >= ifp->if_addrlen); 1223 memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen); 1224 la->la_flags |= LLE_VALID; 1225 if ((la->la_flags & LLE_STATIC) == 0) { 1226 la->la_expire = time_uptime + arpt_keep; 1227 arp_settimer(la, arpt_keep); 1228 } 1229 la->la_asked = 0; 1230 /* rt->rt_flags &= ~RTF_REJECT; */ 1231 1232 if (rt_cmd != 0) { 1233 struct sockaddr_in sin; 1234 1235 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 1236 rt_clonedmsg(rt_cmd, sintosa(&sin), ar_sha(ah), ifp); 1237 } 1238 1239 if (la->la_hold != NULL) { 1240 int n = la->la_numheld; 1241 struct mbuf *m_hold, *m_hold_next; 1242 struct sockaddr_in sin; 1243 1244 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 1245 1246 m_hold = la->la_hold; 1247 la->la_hold = NULL; 1248 la->la_numheld = 0; 1249 /* 1250 * We have to unlock here because if_output would call 1251 * arpresolve 1252 */ 1253 LLE_WUNLOCK(la); 1254 ARP_STATADD(ARP_STAT_DFRSENT, n); 1255 ARP_STATADD(ARP_STAT_DFRTOTAL, n); 1256 for (; m_hold != NULL; m_hold = m_hold_next) { 1257 m_hold_next = m_hold->m_nextpkt; 1258 m_hold->m_nextpkt = NULL; 1259 if_output_lock(ifp, ifp, m_hold, sintosa(&sin), NULL); 1260 } 1261 } else 1262 LLE_WUNLOCK(la); 1263 la = NULL; 1264 1265 reply: 1266 if (la != NULL) { 1267 LLE_WUNLOCK(la); 1268 la = NULL; 1269 } 1270 if (op != ARPOP_REQUEST) { 1271 if (op == ARPOP_REPLY) 1272 ARP_STATINC(ARP_STAT_RCVREPLY); 1273 goto out; 1274 } 1275 ARP_STATINC(ARP_STAT_RCVREQUEST); 1276 if (in_hosteq(itaddr, myaddr)) { 1277 /* If our address is unusable, don't reply */ 1278 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) 1279 goto out; 1280 /* I am the target */ 1281 tha = ar_tha(ah); 1282 if (tha) 1283 memcpy(tha, ar_sha(ah), ah->ar_hln); 1284 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1285 } else { 1286 /* Proxy ARP */ 1287 struct llentry *lle = NULL; 1288 struct sockaddr_in sin; 1289 1290 #if NCARP > 0 1291 if (ifp->if_type == IFT_CARP) { 1292 struct ifnet *_rcvif = m_get_rcvif(m, &s); 1293 int iftype = 0; 1294 if (__predict_true(_rcvif != NULL)) 1295 iftype = _rcvif->if_type; 1296 m_put_rcvif(_rcvif, &s); 1297 if (iftype != IFT_CARP) 1298 goto out; 1299 } 1300 #endif 1301 1302 tha = ar_tha(ah); 1303 1304 sockaddr_in_init(&sin, &itaddr, 0); 1305 1306 IF_AFDATA_RLOCK(ifp); 1307 lle = lla_lookup(LLTABLE(ifp), 0, (struct sockaddr *)&sin); 1308 IF_AFDATA_RUNLOCK(ifp); 1309 1310 if ((lle != NULL) && (lle->la_flags & LLE_PUB)) { 1311 if (tha) 1312 memcpy(tha, ar_sha(ah), ah->ar_hln); 1313 memcpy(ar_sha(ah), &lle->ll_addr, ah->ar_hln); 1314 LLE_RUNLOCK(lle); 1315 } else { 1316 if (lle != NULL) 1317 LLE_RUNLOCK(lle); 1318 goto out; 1319 } 1320 } 1321 ia4_release(ia, &psref_ia); 1322 1323 /* 1324 * XXX XXX: Here we're recycling the mbuf. But the mbuf could have 1325 * other mbufs in its chain, and just overwriting m->m_pkthdr.len 1326 * would be wrong in this case (the length becomes smaller than the 1327 * real chain size). 1328 * 1329 * This can theoretically cause bugs in the lower layers (drivers, 1330 * and L2encap), in some corner cases. 1331 */ 1332 memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); 1333 memcpy(ar_spa(ah), &itaddr, ah->ar_pln); 1334 ah->ar_op = htons(ARPOP_REPLY); 1335 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 1336 switch (ifp->if_type) { 1337 case IFT_IEEE1394: 1338 /* ieee1394 arp reply is broadcast */ 1339 m->m_flags &= ~M_MCAST; 1340 m->m_flags |= M_BCAST; 1341 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + ah->ar_hln; 1342 break; 1343 default: 1344 m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */ 1345 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); 1346 break; 1347 } 1348 m->m_pkthdr.len = m->m_len; 1349 sa.sa_family = AF_ARP; 1350 sa.sa_len = 2; 1351 arps = ARP_STAT_GETREF(); 1352 arps[ARP_STAT_SNDTOTAL]++; 1353 arps[ARP_STAT_SNDREPLY]++; 1354 ARP_STAT_PUTREF(); 1355 if_output_lock(ifp, ifp, m, &sa, NULL); 1356 if (rcvif != NULL) 1357 m_put_rcvif_psref(rcvif, &psref); 1358 return; 1359 1360 out: 1361 if (la != NULL) 1362 LLE_WUNLOCK(la); 1363 if (ia != NULL) 1364 ia4_release(ia, &psref_ia); 1365 if (rcvif != NULL) 1366 m_put_rcvif_psref(rcvif, &psref); 1367 m_freem(m); 1368 } 1369 1370 /* 1371 * Lookup or a new address in arptab. 1372 */ 1373 static struct llentry * 1374 arplookup(struct ifnet *ifp, const struct in_addr *addr, 1375 const struct sockaddr *sa, int wlock) 1376 { 1377 struct sockaddr_in sin; 1378 struct llentry *la; 1379 int flags = wlock ? LLE_EXCLUSIVE : 0; 1380 1381 if (sa == NULL) { 1382 KASSERT(addr != NULL); 1383 sockaddr_in_init(&sin, addr, 0); 1384 sa = sintocsa(&sin); 1385 } 1386 1387 IF_AFDATA_RLOCK(ifp); 1388 la = lla_lookup(LLTABLE(ifp), flags, sa); 1389 IF_AFDATA_RUNLOCK(ifp); 1390 1391 return la; 1392 } 1393 1394 static struct llentry * 1395 arpcreate(struct ifnet *ifp, const struct in_addr *addr, 1396 const struct sockaddr *sa, int wlock) 1397 { 1398 struct sockaddr_in sin; 1399 struct llentry *la; 1400 int flags = wlock ? LLE_EXCLUSIVE : 0; 1401 1402 if (sa == NULL) { 1403 KASSERT(addr != NULL); 1404 sockaddr_in_init(&sin, addr, 0); 1405 sa = sintocsa(&sin); 1406 } 1407 1408 la = arplookup(ifp, addr, sa, wlock); 1409 1410 if (la == NULL) { 1411 struct rtentry *rt; 1412 1413 rt = rtalloc1(sa, 0); 1414 IF_AFDATA_WLOCK(ifp); 1415 la = lla_create(LLTABLE(ifp), flags, sa, rt); 1416 IF_AFDATA_WUNLOCK(ifp); 1417 if (rt != NULL) 1418 rt_unref(rt); 1419 1420 if (la != NULL) 1421 arp_init_llentry(ifp, la); 1422 } 1423 1424 return la; 1425 } 1426 1427 int 1428 arpioctl(u_long cmd, void *data) 1429 { 1430 1431 return EOPNOTSUPP; 1432 } 1433 1434 void 1435 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1436 { 1437 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1438 1439 ifa->ifa_rtrequest = arp_rtrequest; 1440 ifa->ifa_flags |= RTF_CONNECTED; 1441 1442 /* ARP will handle DAD for this address. */ 1443 if (in_nullhost(IA_SIN(ifa)->sin_addr)) { 1444 if (ia->ia_dad_stop != NULL) /* safety */ 1445 ia->ia_dad_stop(ifa); 1446 ia->ia_dad_start = NULL; 1447 ia->ia_dad_stop = NULL; 1448 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1449 } else { 1450 ia->ia_dad_start = arp_dad_start; 1451 ia->ia_dad_stop = arp_dad_stop; 1452 if (ia->ia4_flags & IN_IFF_TRYTENTATIVE && ip_dad_enabled()) 1453 ia->ia4_flags |= IN_IFF_TENTATIVE; 1454 else 1455 arpannounce1(ifa); 1456 } 1457 } 1458 1459 TAILQ_HEAD(dadq_head, dadq); 1460 struct dadq { 1461 TAILQ_ENTRY(dadq) dad_list; 1462 struct ifaddr *dad_ifa; 1463 int dad_count; /* max ARP to send */ 1464 int dad_arp_tcount; /* # of trials to send ARP */ 1465 int dad_arp_ocount; /* ARP sent so far */ 1466 int dad_arp_announce; /* max ARP announcements */ 1467 int dad_arp_acount; /* # of announcements */ 1468 struct callout dad_timer_ch; 1469 }; 1470 1471 static struct dadq_head dadq; 1472 static int dad_maxtry = 15; /* max # of *tries* to transmit DAD packet */ 1473 static kmutex_t arp_dad_lock; 1474 1475 static void 1476 arp_dad_init(void) 1477 { 1478 1479 TAILQ_INIT(&dadq); 1480 mutex_init(&arp_dad_lock, MUTEX_DEFAULT, IPL_NONE); 1481 } 1482 1483 static struct dadq * 1484 arp_dad_find(struct ifaddr *ifa) 1485 { 1486 struct dadq *dp; 1487 1488 KASSERT(mutex_owned(&arp_dad_lock)); 1489 1490 TAILQ_FOREACH(dp, &dadq, dad_list) { 1491 if (dp->dad_ifa == ifa) 1492 return dp; 1493 } 1494 return NULL; 1495 } 1496 1497 static void 1498 arp_dad_starttimer(struct dadq *dp, int ticks) 1499 { 1500 1501 callout_reset(&dp->dad_timer_ch, ticks, 1502 (void (*)(void *))arp_dad_timer, dp); 1503 } 1504 1505 static void 1506 arp_dad_stoptimer(struct dadq *dp) 1507 { 1508 1509 KASSERT(mutex_owned(&arp_dad_lock)); 1510 1511 TAILQ_REMOVE(&dadq, dp, dad_list); 1512 /* Tell the timer that dp is being destroyed. */ 1513 dp->dad_ifa = NULL; 1514 callout_halt(&dp->dad_timer_ch, &arp_dad_lock); 1515 } 1516 1517 static void 1518 arp_dad_destroytimer(struct dadq *dp) 1519 { 1520 1521 callout_destroy(&dp->dad_timer_ch); 1522 KASSERT(dp->dad_ifa == NULL); 1523 kmem_intr_free(dp, sizeof(*dp)); 1524 } 1525 1526 static void 1527 arp_dad_output(struct dadq *dp, struct ifaddr *ifa) 1528 { 1529 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1530 struct ifnet *ifp = ifa->ifa_ifp; 1531 struct in_addr sip; 1532 1533 dp->dad_arp_tcount++; 1534 if ((ifp->if_flags & IFF_UP) == 0) 1535 return; 1536 if ((ifp->if_flags & IFF_RUNNING) == 0) 1537 return; 1538 1539 dp->dad_arp_tcount = 0; 1540 dp->dad_arp_ocount++; 1541 1542 memset(&sip, 0, sizeof(sip)); 1543 arprequest(ifa->ifa_ifp, &sip, &ia->ia_addr.sin_addr, 1544 CLLADDR(ifa->ifa_ifp->if_sadl)); 1545 } 1546 1547 /* 1548 * Start Duplicate Address Detection (DAD) for specified interface address. 1549 */ 1550 static void 1551 arp_dad_start(struct ifaddr *ifa) 1552 { 1553 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1554 struct dadq *dp; 1555 char ipbuf[INET_ADDRSTRLEN]; 1556 1557 /* 1558 * If we don't need DAD, don't do it. 1559 * - DAD is disabled 1560 */ 1561 if (!(ia->ia4_flags & IN_IFF_TENTATIVE)) { 1562 log(LOG_DEBUG, 1563 "%s: called with non-tentative address %s(%s)\n", __func__, 1564 IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1565 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1566 return; 1567 } 1568 if (!ip_dad_enabled()) { 1569 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1570 rt_addrmsg(RTM_NEWADDR, ifa); 1571 arpannounce1(ifa); 1572 return; 1573 } 1574 KASSERT(ifa->ifa_ifp != NULL); 1575 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) 1576 return; 1577 1578 dp = kmem_intr_alloc(sizeof(*dp), KM_NOSLEEP); 1579 1580 mutex_enter(&arp_dad_lock); 1581 if (arp_dad_find(ifa) != NULL) { 1582 mutex_exit(&arp_dad_lock); 1583 /* DAD already in progress */ 1584 if (dp != NULL) 1585 kmem_intr_free(dp, sizeof(*dp)); 1586 return; 1587 } 1588 1589 if (dp == NULL) { 1590 mutex_exit(&arp_dad_lock); 1591 log(LOG_ERR, "%s: memory allocation failed for %s(%s)\n", 1592 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1593 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1594 return; 1595 } 1596 1597 /* 1598 * Send ARP packet for DAD, ip_dad_count times. 1599 * Note that we must delay the first transmission. 1600 */ 1601 callout_init(&dp->dad_timer_ch, CALLOUT_MPSAFE); 1602 dp->dad_ifa = ifa; 1603 ifaref(ifa); /* just for safety */ 1604 dp->dad_count = ip_dad_count; 1605 dp->dad_arp_announce = 0; /* Will be set when starting to announce */ 1606 dp->dad_arp_acount = dp->dad_arp_ocount = dp->dad_arp_tcount = 0; 1607 TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list); 1608 1609 ARPLOG(LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1610 ARPLOGADDR(&ia->ia_addr.sin_addr)); 1611 1612 arp_dad_starttimer(dp, cprng_fast32() % (PROBE_WAIT * hz)); 1613 1614 mutex_exit(&arp_dad_lock); 1615 } 1616 1617 /* 1618 * terminate DAD unconditionally. used for address removals. 1619 */ 1620 static void 1621 arp_dad_stop(struct ifaddr *ifa) 1622 { 1623 struct dadq *dp; 1624 1625 mutex_enter(&arp_dad_lock); 1626 dp = arp_dad_find(ifa); 1627 if (dp == NULL) { 1628 mutex_exit(&arp_dad_lock); 1629 /* DAD wasn't started yet */ 1630 return; 1631 } 1632 1633 arp_dad_stoptimer(dp); 1634 1635 mutex_exit(&arp_dad_lock); 1636 1637 arp_dad_destroytimer(dp); 1638 ifafree(ifa); 1639 } 1640 1641 static void 1642 arp_dad_timer(struct dadq *dp) 1643 { 1644 struct ifaddr *ifa; 1645 struct in_ifaddr *ia; 1646 char ipbuf[INET_ADDRSTRLEN]; 1647 bool need_free = false; 1648 1649 KERNEL_LOCK_UNLESS_NET_MPSAFE(); 1650 mutex_enter(&arp_dad_lock); 1651 1652 ifa = dp->dad_ifa; 1653 if (ifa == NULL) { 1654 /* dp is being destroyed by someone. Do nothing. */ 1655 goto done; 1656 } 1657 1658 ia = (struct in_ifaddr *)ifa; 1659 if (ia->ia4_flags & IN_IFF_DUPLICATED) { 1660 log(LOG_ERR, "%s: called with duplicate address %s(%s)\n", 1661 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1662 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1663 goto done; 1664 } 1665 if ((ia->ia4_flags & IN_IFF_TENTATIVE) == 0 && dp->dad_arp_acount == 0) 1666 { 1667 log(LOG_ERR, "%s: called with non-tentative address %s(%s)\n", 1668 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1669 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1670 goto done; 1671 } 1672 1673 /* timeouted with IFF_{RUNNING,UP} check */ 1674 if (dp->dad_arp_tcount > dad_maxtry) { 1675 ARPLOG(LOG_INFO, "%s: could not run DAD, driver problem?\n", 1676 if_name(ifa->ifa_ifp)); 1677 1678 arp_dad_stoptimer(dp); 1679 need_free = true; 1680 goto done; 1681 } 1682 1683 /* Need more checks? */ 1684 if (dp->dad_arp_ocount < dp->dad_count) { 1685 int adelay; 1686 1687 /* 1688 * We have more ARP to go. Send ARP packet for DAD. 1689 */ 1690 arp_dad_output(dp, ifa); 1691 if (dp->dad_arp_ocount < dp->dad_count) 1692 adelay = (PROBE_MIN * hz) + 1693 (cprng_fast32() % 1694 ((PROBE_MAX * hz) - (PROBE_MIN * hz))); 1695 else 1696 adelay = ANNOUNCE_WAIT * hz; 1697 arp_dad_starttimer(dp, adelay); 1698 goto done; 1699 } else if (dp->dad_arp_acount == 0) { 1700 /* 1701 * We are done with DAD. 1702 * No duplicate address found. 1703 */ 1704 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1705 rt_addrmsg(RTM_NEWADDR, ifa); 1706 ARPLOG(LOG_DEBUG, 1707 "%s: DAD complete for %s - no duplicates found\n", 1708 if_name(ifa->ifa_ifp), ARPLOGADDR(&ia->ia_addr.sin_addr)); 1709 dp->dad_arp_announce = ANNOUNCE_NUM; 1710 goto announce; 1711 } else if (dp->dad_arp_acount < dp->dad_arp_announce) { 1712 announce: 1713 /* 1714 * Announce the address. 1715 */ 1716 arpannounce1(ifa); 1717 dp->dad_arp_acount++; 1718 if (dp->dad_arp_acount < dp->dad_arp_announce) { 1719 arp_dad_starttimer(dp, ANNOUNCE_INTERVAL * hz); 1720 goto done; 1721 } 1722 ARPLOG(LOG_DEBUG, 1723 "%s: ARP announcement complete for %s\n", 1724 if_name(ifa->ifa_ifp), ARPLOGADDR(&ia->ia_addr.sin_addr)); 1725 } 1726 1727 arp_dad_stoptimer(dp); 1728 need_free = true; 1729 done: 1730 mutex_exit(&arp_dad_lock); 1731 1732 if (need_free) { 1733 arp_dad_destroytimer(dp); 1734 KASSERT(ifa != NULL); 1735 ifafree(ifa); 1736 } 1737 1738 KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 1739 } 1740 1741 static void 1742 arp_dad_duplicated(struct ifaddr *ifa, const struct sockaddr_dl *from) 1743 { 1744 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1745 struct ifnet *ifp = ifa->ifa_ifp; 1746 char ipbuf[INET_ADDRSTRLEN], llabuf[LLA_ADDRSTRLEN]; 1747 const char *iastr, *llastr; 1748 1749 iastr = IN_PRINT(ipbuf, &ia->ia_addr.sin_addr); 1750 if (__predict_false(from == NULL)) 1751 llastr = NULL; 1752 else 1753 llastr = lla_snprintf(llabuf, sizeof(llabuf), 1754 CLLADDR(from), from->sdl_alen); 1755 1756 if (ia->ia4_flags & (IN_IFF_TENTATIVE|IN_IFF_DUPLICATED)) { 1757 log(LOG_ERR, 1758 "%s: DAD duplicate address %s from %s\n", 1759 if_name(ifp), iastr, llastr); 1760 } else if (ia->ia_dad_defended == 0 || 1761 ia->ia_dad_defended < time_uptime - DEFEND_INTERVAL) { 1762 ia->ia_dad_defended = time_uptime; 1763 arpannounce1(ifa); 1764 log(LOG_ERR, 1765 "%s: DAD defended address %s from %s\n", 1766 if_name(ifp), iastr, llastr); 1767 return; 1768 } else { 1769 /* If DAD is disabled, just report the duplicate. */ 1770 if (!ip_dad_enabled()) { 1771 log(LOG_ERR, 1772 "%s: DAD ignoring duplicate address %s from %s\n", 1773 if_name(ifp), iastr, llastr); 1774 return; 1775 } 1776 log(LOG_ERR, 1777 "%s: DAD defence failed for %s from %s\n", 1778 if_name(ifp), iastr, llastr); 1779 } 1780 1781 arp_dad_stop(ifa); 1782 1783 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1784 if ((ia->ia4_flags & IN_IFF_DUPLICATED) == 0) { 1785 ia->ia4_flags |= IN_IFF_DUPLICATED; 1786 /* Inform the routing socket of the duplicate address */ 1787 rt_addrmsg_src(RTM_NEWADDR, ifa, (const struct sockaddr *)from); 1788 } 1789 } 1790 1791 /* 1792 * Called from 10 Mb/s Ethernet interrupt handlers 1793 * when ether packet type ETHERTYPE_REVARP 1794 * is received. Common length and type checks are done here, 1795 * then the protocol-specific routine is called. 1796 */ 1797 void 1798 revarpinput(struct mbuf *m) 1799 { 1800 struct arphdr *ar; 1801 int arplen; 1802 1803 arplen = sizeof(struct arphdr); 1804 if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL) 1805 return; 1806 ar = mtod(m, struct arphdr *); 1807 1808 if (ntohs(ar->ar_hrd) == ARPHRD_IEEE1394) { 1809 goto out; 1810 } 1811 1812 arplen = sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln); 1813 if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL) 1814 return; 1815 ar = mtod(m, struct arphdr *); 1816 1817 switch (ntohs(ar->ar_pro)) { 1818 case ETHERTYPE_IP: 1819 case ETHERTYPE_IPTRAILERS: 1820 in_revarpinput(m); 1821 return; 1822 1823 default: 1824 break; 1825 } 1826 1827 out: 1828 m_freem(m); 1829 } 1830 1831 /* 1832 * RARP for Internet protocols on 10 Mb/s Ethernet. 1833 * Algorithm is that given in RFC 903. 1834 * We are only using for bootstrap purposes to get an ip address for one of 1835 * our interfaces. Thus we support no user-interface. 1836 * 1837 * Since the contents of the RARP reply are specific to the interface that 1838 * sent the request, this code must ensure that they are properly associated. 1839 * 1840 * Note: also supports ARP via RARP packets, per the RFC. 1841 */ 1842 void 1843 in_revarpinput(struct mbuf *m) 1844 { 1845 struct arphdr *ah; 1846 void *tha; 1847 int op; 1848 struct ifnet *rcvif; 1849 int s; 1850 1851 ah = mtod(m, struct arphdr *); 1852 op = ntohs(ah->ar_op); 1853 1854 rcvif = m_get_rcvif(m, &s); 1855 if (__predict_false(rcvif == NULL)) 1856 goto out; 1857 if (rcvif->if_flags & IFF_NOARP) 1858 goto out; 1859 1860 switch (rcvif->if_type) { 1861 case IFT_IEEE1394: 1862 /* ARP without target hardware address is not supported */ 1863 goto out; 1864 default: 1865 break; 1866 } 1867 1868 switch (op) { 1869 case ARPOP_REQUEST: 1870 case ARPOP_REPLY: /* per RFC */ 1871 m_put_rcvif(rcvif, &s); 1872 in_arpinput(m); 1873 return; 1874 case ARPOP_REVREPLY: 1875 break; 1876 case ARPOP_REVREQUEST: /* handled by rarpd(8) */ 1877 default: 1878 goto out; 1879 } 1880 if (!revarp_in_progress) 1881 goto out; 1882 if (rcvif != myip_ifp) /* !same interface */ 1883 goto out; 1884 if (myip_initialized) 1885 goto wake; 1886 tha = ar_tha(ah); 1887 if (tha == NULL) 1888 goto out; 1889 if (ah->ar_pln != sizeof(struct in_addr)) 1890 goto out; 1891 if (ah->ar_hln != rcvif->if_sadl->sdl_alen) 1892 goto out; 1893 if (memcmp(tha, CLLADDR(rcvif->if_sadl), rcvif->if_sadl->sdl_alen)) 1894 goto out; 1895 memcpy(&srv_ip, ar_spa(ah), sizeof(srv_ip)); 1896 memcpy(&myip, ar_tpa(ah), sizeof(myip)); 1897 myip_initialized = 1; 1898 wake: /* Do wakeup every time in case it was missed. */ 1899 wakeup((void *)&myip); 1900 1901 out: 1902 m_put_rcvif(rcvif, &s); 1903 m_freem(m); 1904 } 1905 1906 /* 1907 * Send a RARP request for the ip address of the specified interface. 1908 * The request should be RFC 903-compliant. 1909 */ 1910 static void 1911 revarprequest(struct ifnet *ifp) 1912 { 1913 struct sockaddr sa; 1914 struct mbuf *m; 1915 struct arphdr *ah; 1916 void *tha; 1917 1918 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 1919 return; 1920 MCLAIM(m, &arpdomain.dom_mowner); 1921 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) + 1922 2*ifp->if_addrlen; 1923 m->m_pkthdr.len = m->m_len; 1924 m_align(m, m->m_len); 1925 ah = mtod(m, struct arphdr *); 1926 memset(ah, 0, m->m_len); 1927 ah->ar_pro = htons(ETHERTYPE_IP); 1928 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 1929 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 1930 ah->ar_op = htons(ARPOP_REVREQUEST); 1931 1932 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1933 tha = ar_tha(ah); 1934 if (tha == NULL) { 1935 m_free(m); 1936 return; 1937 } 1938 memcpy(tha, CLLADDR(ifp->if_sadl), ah->ar_hln); 1939 1940 sa.sa_family = AF_ARP; 1941 sa.sa_len = 2; 1942 m->m_flags |= M_BCAST; 1943 1944 if_output_lock(ifp, ifp, m, &sa, NULL); 1945 } 1946 1947 /* 1948 * RARP for the ip address of the specified interface, but also 1949 * save the ip address of the server that sent the answer. 1950 * Timeout if no response is received. 1951 */ 1952 int 1953 revarpwhoarewe(struct ifnet *ifp, struct in_addr *serv_in, 1954 struct in_addr *clnt_in) 1955 { 1956 int result, count = 20; 1957 1958 myip_initialized = 0; 1959 myip_ifp = ifp; 1960 1961 revarp_in_progress = 1; 1962 while (count--) { 1963 revarprequest(ifp); 1964 result = tsleep((void *)&myip, PSOCK, "revarp", hz/2); 1965 if (result != EWOULDBLOCK) 1966 break; 1967 } 1968 revarp_in_progress = 0; 1969 1970 if (!myip_initialized) 1971 return ENETUNREACH; 1972 1973 memcpy(serv_in, &srv_ip, sizeof(*serv_in)); 1974 memcpy(clnt_in, &myip, sizeof(*clnt_in)); 1975 return 0; 1976 } 1977 1978 void 1979 arp_stat_add(int type, uint64_t count) 1980 { 1981 ARP_STATADD(type, count); 1982 } 1983 1984 static int 1985 sysctl_net_inet_arp_stats(SYSCTLFN_ARGS) 1986 { 1987 1988 return NETSTAT_SYSCTL(arpstat_percpu, ARP_NSTATS); 1989 } 1990 1991 static void 1992 sysctl_net_inet_arp_setup(struct sysctllog **clog) 1993 { 1994 const struct sysctlnode *node; 1995 1996 sysctl_createv(clog, 0, NULL, NULL, 1997 CTLFLAG_PERMANENT, 1998 CTLTYPE_NODE, "inet", NULL, 1999 NULL, 0, NULL, 0, 2000 CTL_NET, PF_INET, CTL_EOL); 2001 sysctl_createv(clog, 0, NULL, &node, 2002 CTLFLAG_PERMANENT, 2003 CTLTYPE_NODE, "arp", 2004 SYSCTL_DESCR("Address Resolution Protocol"), 2005 NULL, 0, NULL, 0, 2006 CTL_NET, PF_INET, CTL_CREATE, CTL_EOL); 2007 2008 sysctl_createv(clog, 0, NULL, NULL, 2009 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2010 CTLTYPE_INT, "keep", 2011 SYSCTL_DESCR("Valid ARP entry lifetime in seconds"), 2012 NULL, 0, &arpt_keep, 0, 2013 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2014 2015 sysctl_createv(clog, 0, NULL, NULL, 2016 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2017 CTLTYPE_INT, "down", 2018 SYSCTL_DESCR("Failed ARP entry lifetime in seconds"), 2019 NULL, 0, &arpt_down, 0, 2020 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2021 2022 sysctl_createv(clog, 0, NULL, NULL, 2023 CTLFLAG_PERMANENT, 2024 CTLTYPE_STRUCT, "stats", 2025 SYSCTL_DESCR("ARP statistics"), 2026 sysctl_net_inet_arp_stats, 0, NULL, 0, 2027 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2028 2029 sysctl_createv(clog, 0, NULL, NULL, 2030 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2031 CTLTYPE_INT, "log_movements", 2032 SYSCTL_DESCR("log ARP replies from MACs different than" 2033 " the one in the cache"), 2034 NULL, 0, &log_movements, 0, 2035 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2036 2037 sysctl_createv(clog, 0, NULL, NULL, 2038 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2039 CTLTYPE_INT, "log_permanent_modify", 2040 SYSCTL_DESCR("log ARP replies from MACs different than" 2041 " the one in the permanent arp entry"), 2042 NULL, 0, &log_permanent_modify, 0, 2043 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2044 2045 sysctl_createv(clog, 0, NULL, NULL, 2046 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2047 CTLTYPE_INT, "log_wrong_iface", 2048 SYSCTL_DESCR("log ARP packets arriving on the wrong" 2049 " interface"), 2050 NULL, 0, &log_wrong_iface, 0, 2051 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2052 2053 sysctl_createv(clog, 0, NULL, NULL, 2054 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2055 CTLTYPE_INT, "debug", 2056 SYSCTL_DESCR("Enable ARP DAD debug output"), 2057 NULL, 0, &arp_debug, 0, 2058 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2059 } 2060 2061 #endif /* INET */ 2062
Indexes created Tue Nov 10 00:26:44 UTC 2026