1 /* $NetBSD: if_arp.c,v 1.273 2018/04/11 05:38:47 maxv 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 1.273 2018/04/11 05:38:47 maxv 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_token.h> 109 #include <net/if_types.h> 110 #include <net/if_ether.h> 111 #include <net/if_llatbl.h> 112 #include <net/net_osdep.h> 113 #include <net/route.h> 114 #include <net/net_stats.h> 115 116 #include <netinet/in.h> 117 #include <netinet/in_systm.h> 118 #include <netinet/in_var.h> 119 #include <netinet/ip.h> 120 #include <netinet/if_inarp.h> 121 122 #include "arcnet.h" 123 #if NARCNET > 0 124 #include <net/if_arc.h> 125 #endif 126 #include "fddi.h" 127 #if NFDDI > 0 128 #include <net/if_fddi.h> 129 #endif 130 #include "token.h" 131 #include "carp.h" 132 #if NCARP > 0 133 #include <netinet/ip_carp.h> 134 #endif 135 136 /* 137 * ARP trailer negotiation. Trailer protocol is not IP specific, 138 * but ARP request/response use IP addresses. 139 */ 140 #define ETHERTYPE_IPTRAILERS ETHERTYPE_TRAIL 141 142 /* timer values */ 143 static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */ 144 static int arpt_down = 20; /* once declared down, don't send for 20 secs */ 145 static int arp_maxhold = 1; /* number of packets to hold per ARP entry */ 146 #define rt_expire rt_rmx.rmx_expire 147 #define rt_pksent rt_rmx.rmx_pksent 148 149 int ip_dad_count = PROBE_NUM; 150 #ifdef ARP_DEBUG 151 int arp_debug = 1; 152 #else 153 int arp_debug = 0; 154 #endif 155 156 static void arp_init(void); 157 158 static void arprequest(struct ifnet *, 159 const struct in_addr *, const struct in_addr *, 160 const uint8_t *); 161 static void arpannounce1(struct ifaddr *); 162 static struct sockaddr *arp_setgate(struct rtentry *, struct sockaddr *, 163 const struct sockaddr *); 164 static void arptimer(void *); 165 static void arp_settimer(struct llentry *, int); 166 static struct llentry *arplookup(struct ifnet *, 167 const struct in_addr *, const struct sockaddr *, int); 168 static struct llentry *arpcreate(struct ifnet *, 169 const struct in_addr *, const struct sockaddr *, int); 170 static void in_arpinput(struct mbuf *); 171 static void in_revarpinput(struct mbuf *); 172 static void revarprequest(struct ifnet *); 173 174 static void arp_drainstub(void); 175 176 struct dadq; 177 static void arp_dad_timer(struct dadq *); 178 static void arp_dad_start(struct ifaddr *); 179 static void arp_dad_stop(struct ifaddr *); 180 static void arp_dad_duplicated(struct ifaddr *, const char *); 181 182 static void arp_init_llentry(struct ifnet *, struct llentry *); 183 #if NTOKEN > 0 184 static void arp_free_llentry_tokenring(struct llentry *); 185 #endif 186 187 struct ifqueue arpintrq = { 188 .ifq_head = NULL, 189 .ifq_tail = NULL, 190 .ifq_len = 0, 191 .ifq_maxlen = 50, 192 .ifq_drops = 0, 193 }; 194 static int arp_maxtries = 5; 195 static int useloopback = 1; /* use loopback interface for local traffic */ 196 197 static percpu_t *arpstat_percpu; 198 199 #define ARP_STAT_GETREF() _NET_STAT_GETREF(arpstat_percpu) 200 #define ARP_STAT_PUTREF() _NET_STAT_PUTREF(arpstat_percpu) 201 202 #define ARP_STATINC(x) _NET_STATINC(arpstat_percpu, x) 203 #define ARP_STATADD(x, v) _NET_STATADD(arpstat_percpu, x, v) 204 205 /* revarp state */ 206 static struct in_addr myip, srv_ip; 207 static int myip_initialized = 0; 208 static int revarp_in_progress = 0; 209 static struct ifnet *myip_ifp = NULL; 210 211 static int arp_drainwanted; 212 213 static int log_movements = 1; 214 static int log_permanent_modify = 1; 215 static int log_wrong_iface = 1; 216 static int log_unknown_network = 1; 217 218 /* 219 * this should be elsewhere. 220 */ 221 222 #define LLA_ADDRSTRLEN (16 * 3) 223 224 static char * 225 lla_snprintf(char *, const u_int8_t *, int); 226 227 static char * 228 lla_snprintf(char *dst, const u_int8_t *adrp, int len) 229 { 230 int i; 231 char *p; 232 233 p = dst; 234 235 *p++ = hexdigits[(*adrp) >> 4]; 236 *p++ = hexdigits[(*adrp++) & 0xf]; 237 238 for (i = 1; i < len && i < 16; i++) { 239 *p++ = ':'; 240 *p++ = hexdigits[(*adrp) >> 4]; 241 *p++ = hexdigits[(*adrp++) & 0xf]; 242 } 243 244 *p = 0; 245 return dst; 246 } 247 248 DOMAIN_DEFINE(arpdomain); /* forward declare and add to link set */ 249 250 static void 251 arp_fasttimo(void) 252 { 253 if (arp_drainwanted) { 254 arp_drain(); 255 arp_drainwanted = 0; 256 } 257 } 258 259 const struct protosw arpsw[] = { 260 { 261 .pr_type = 0, 262 .pr_domain = &arpdomain, 263 .pr_protocol = 0, 264 .pr_flags = 0, 265 .pr_input = 0, 266 .pr_ctlinput = 0, 267 .pr_ctloutput = 0, 268 .pr_usrreqs = 0, 269 .pr_init = arp_init, 270 .pr_fasttimo = arp_fasttimo, 271 .pr_slowtimo = 0, 272 .pr_drain = arp_drainstub, 273 } 274 }; 275 276 struct domain arpdomain = { 277 .dom_family = PF_ARP, 278 .dom_name = "arp", 279 .dom_protosw = arpsw, 280 .dom_protoswNPROTOSW = &arpsw[__arraycount(arpsw)], 281 }; 282 283 static void sysctl_net_inet_arp_setup(struct sysctllog **); 284 285 void 286 arp_init(void) 287 { 288 289 sysctl_net_inet_arp_setup(NULL); 290 arpstat_percpu = percpu_alloc(sizeof(uint64_t) * ARP_NSTATS); 291 IFQ_LOCK_INIT(&arpintrq); 292 } 293 294 static void 295 arp_drainstub(void) 296 { 297 arp_drainwanted = 1; 298 } 299 300 /* 301 * ARP protocol drain routine. Called when memory is in short supply. 302 * Called at splvm(); don't acquire softnet_lock as can be called from 303 * hardware interrupt handlers. 304 */ 305 void 306 arp_drain(void) 307 { 308 309 lltable_drain(AF_INET); 310 } 311 312 static void 313 arptimer(void *arg) 314 { 315 struct llentry *lle = arg; 316 struct ifnet *ifp; 317 318 KASSERT((lle->la_flags & LLE_STATIC) == 0); 319 320 LLE_WLOCK(lle); 321 322 /* 323 * This shortcut is required to avoid trying to touch ifp that may be 324 * being destroyed. 325 */ 326 if ((lle->la_flags & LLE_LINKED) == 0) { 327 LLE_FREE_LOCKED(lle); 328 return; 329 } 330 331 ifp = lle->lle_tbl->llt_ifp; 332 333 /* XXX: LOR avoidance. We still have ref on lle. */ 334 LLE_WUNLOCK(lle); 335 336 IF_AFDATA_LOCK(ifp); 337 LLE_WLOCK(lle); 338 339 /* Guard against race with other llentry_free(). */ 340 if (lle->la_flags & LLE_LINKED) { 341 size_t pkts_dropped; 342 343 LLE_REMREF(lle); 344 pkts_dropped = llentry_free(lle); 345 ARP_STATADD(ARP_STAT_DFRDROPPED, pkts_dropped); 346 ARP_STATADD(ARP_STAT_DFRTOTAL, pkts_dropped); 347 } else { 348 LLE_FREE_LOCKED(lle); 349 } 350 351 IF_AFDATA_UNLOCK(ifp); 352 } 353 354 static void 355 arp_settimer(struct llentry *la, int sec) 356 { 357 358 LLE_WLOCK_ASSERT(la); 359 KASSERT((la->la_flags & LLE_STATIC) == 0); 360 361 /* 362 * We have to take care of a reference leak which occurs if 363 * callout_reset overwrites a pending callout schedule. Unfortunately 364 * we don't have a mean to know the overwrite, so we need to know it 365 * using callout_stop. We need to call callout_pending first to exclude 366 * the case that the callout has never been scheduled. 367 */ 368 if (callout_pending(&la->la_timer)) { 369 bool expired = callout_stop(&la->la_timer); 370 if (!expired) 371 /* A pending callout schedule is canceled. */ 372 LLE_REMREF(la); 373 } 374 LLE_ADDREF(la); 375 callout_reset(&la->la_timer, hz * sec, arptimer, la); 376 } 377 378 /* 379 * We set the gateway for RTF_CLONING routes to a "prototype" 380 * link-layer sockaddr whose interface type (if_type) and interface 381 * index (if_index) fields are prepared. 382 */ 383 static struct sockaddr * 384 arp_setgate(struct rtentry *rt, struct sockaddr *gate, 385 const struct sockaddr *netmask) 386 { 387 const struct ifnet *ifp = rt->rt_ifp; 388 uint8_t namelen = strlen(ifp->if_xname); 389 uint8_t addrlen = ifp->if_addrlen; 390 391 /* 392 * XXX: If this is a manually added route to interface 393 * such as older version of routed or gated might provide, 394 * restore cloning bit. 395 */ 396 if ((rt->rt_flags & RTF_HOST) == 0 && netmask != NULL && 397 satocsin(netmask)->sin_addr.s_addr != 0xffffffff) 398 rt->rt_flags |= RTF_CONNECTED; 399 400 if ((rt->rt_flags & (RTF_CONNECTED | RTF_LOCAL))) { 401 union { 402 struct sockaddr sa; 403 struct sockaddr_storage ss; 404 struct sockaddr_dl sdl; 405 } u; 406 /* 407 * Case 1: This route should come from a route to iface. 408 */ 409 sockaddr_dl_init(&u.sdl, sizeof(u.ss), 410 ifp->if_index, ifp->if_type, NULL, namelen, NULL, addrlen); 411 rt_setgate(rt, &u.sa); 412 gate = rt->rt_gateway; 413 } 414 return gate; 415 } 416 417 static void 418 arp_init_llentry(struct ifnet *ifp, struct llentry *lle) 419 { 420 421 switch (ifp->if_type) { 422 #if NTOKEN > 0 423 case IFT_ISO88025: 424 lle->la_opaque = kmem_intr_alloc(sizeof(struct token_rif), 425 KM_NOSLEEP); 426 lle->lle_ll_free = arp_free_llentry_tokenring; 427 break; 428 #endif 429 } 430 } 431 432 #if NTOKEN > 0 433 static void 434 arp_free_llentry_tokenring(struct llentry *lle) 435 { 436 437 kmem_intr_free(lle->la_opaque, sizeof(struct token_rif)); 438 } 439 #endif 440 441 /* 442 * Parallel to llc_rtrequest. 443 */ 444 void 445 arp_rtrequest(int req, struct rtentry *rt, const struct rt_addrinfo *info) 446 { 447 struct sockaddr *gate = rt->rt_gateway; 448 struct in_ifaddr *ia; 449 struct ifaddr *ifa; 450 struct ifnet *ifp = rt->rt_ifp; 451 int bound; 452 int s; 453 454 if (req == RTM_LLINFO_UPD) { 455 if ((ifa = info->rti_ifa) != NULL) 456 arpannounce1(ifa); 457 return; 458 } 459 460 if ((rt->rt_flags & RTF_GATEWAY) != 0) { 461 if (req != RTM_ADD) 462 return; 463 464 /* 465 * linklayers with particular link MTU limitation. 466 */ 467 switch(ifp->if_type) { 468 #if NFDDI > 0 469 case IFT_FDDI: 470 if (ifp->if_mtu > FDDIIPMTU) 471 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 472 break; 473 #endif 474 #if NARCNET > 0 475 case IFT_ARCNET: 476 { 477 int arcipifmtu; 478 479 if (ifp->if_flags & IFF_LINK0) 480 arcipifmtu = arc_ipmtu; 481 else 482 arcipifmtu = ARCMTU; 483 if (ifp->if_mtu > arcipifmtu) 484 rt->rt_rmx.rmx_mtu = arcipifmtu; 485 break; 486 } 487 #endif 488 } 489 return; 490 } 491 492 switch (req) { 493 case RTM_SETGATE: 494 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 495 break; 496 case RTM_ADD: 497 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 498 if (gate == NULL) { 499 log(LOG_ERR, "%s: arp_setgate failed\n", __func__); 500 break; 501 } 502 if ((rt->rt_flags & RTF_CONNECTED) || 503 (rt->rt_flags & RTF_LOCAL)) { 504 /* 505 * Give this route an expiration time, even though 506 * it's a "permanent" route, so that routes cloned 507 * from it do not need their expiration time set. 508 */ 509 KASSERT(time_uptime != 0); 510 rt->rt_expire = time_uptime; 511 /* 512 * linklayers with particular link MTU limitation. 513 */ 514 switch (ifp->if_type) { 515 #if NFDDI > 0 516 case IFT_FDDI: 517 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 518 (rt->rt_rmx.rmx_mtu > FDDIIPMTU || 519 (rt->rt_rmx.rmx_mtu == 0 && 520 ifp->if_mtu > FDDIIPMTU))) 521 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 522 break; 523 #endif 524 #if NARCNET > 0 525 case IFT_ARCNET: 526 { 527 int arcipifmtu; 528 if (ifp->if_flags & IFF_LINK0) 529 arcipifmtu = arc_ipmtu; 530 else 531 arcipifmtu = ARCMTU; 532 533 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 534 (rt->rt_rmx.rmx_mtu > arcipifmtu || 535 (rt->rt_rmx.rmx_mtu == 0 && 536 ifp->if_mtu > arcipifmtu))) 537 rt->rt_rmx.rmx_mtu = arcipifmtu; 538 break; 539 } 540 #endif 541 } 542 if (rt->rt_flags & RTF_CONNECTED) 543 break; 544 } 545 546 bound = curlwp_bind(); 547 /* Announce a new entry if requested. */ 548 if (rt->rt_flags & RTF_ANNOUNCE) { 549 struct psref psref; 550 ia = in_get_ia_on_iface_psref( 551 satocsin(rt_getkey(rt))->sin_addr, ifp, &psref); 552 if (ia != NULL) { 553 arpannounce(ifp, &ia->ia_ifa, 554 CLLADDR(satocsdl(gate))); 555 ia4_release(ia, &psref); 556 } 557 } 558 559 if (gate->sa_family != AF_LINK || 560 gate->sa_len < sockaddr_dl_measure(0, ifp->if_addrlen)) { 561 log(LOG_DEBUG, "%s: bad gateway value\n", __func__); 562 goto out; 563 } 564 565 satosdl(gate)->sdl_type = ifp->if_type; 566 satosdl(gate)->sdl_index = ifp->if_index; 567 568 /* 569 * If the route is for a broadcast address mark it as such. 570 * This way we can avoid an expensive call to in_broadcast() 571 * in ip_output() most of the time (because the route passed 572 * to ip_output() is almost always a host route). 573 */ 574 if (rt->rt_flags & RTF_HOST && 575 !(rt->rt_flags & RTF_BROADCAST) && 576 in_broadcast(satocsin(rt_getkey(rt))->sin_addr, rt->rt_ifp)) 577 rt->rt_flags |= RTF_BROADCAST; 578 /* There is little point in resolving the broadcast address */ 579 if (rt->rt_flags & RTF_BROADCAST) 580 goto out; 581 582 /* 583 * When called from rt_ifa_addlocal, we cannot depend on that 584 * the address (rt_getkey(rt)) exits in the address list of the 585 * interface. So check RTF_LOCAL instead. 586 */ 587 if (rt->rt_flags & RTF_LOCAL) { 588 rt->rt_expire = 0; 589 if (useloopback) { 590 rt->rt_ifp = lo0ifp; 591 rt->rt_rmx.rmx_mtu = 0; 592 } 593 goto out; 594 } 595 596 s = pserialize_read_enter(); 597 ia = in_get_ia_on_iface(satocsin(rt_getkey(rt))->sin_addr, ifp); 598 if (ia == NULL) { 599 pserialize_read_exit(s); 600 goto out; 601 } 602 603 rt->rt_expire = 0; 604 if (useloopback) { 605 rt->rt_ifp = lo0ifp; 606 rt->rt_rmx.rmx_mtu = 0; 607 } 608 rt->rt_flags |= RTF_LOCAL; 609 /* 610 * make sure to set rt->rt_ifa to the interface 611 * address we are using, otherwise we will have trouble 612 * with source address selection. 613 */ 614 ifa = &ia->ia_ifa; 615 if (ifa != rt->rt_ifa) 616 /* Assume it doesn't sleep */ 617 rt_replace_ifa(rt, ifa); 618 pserialize_read_exit(s); 619 out: 620 curlwp_bindx(bound); 621 break; 622 } 623 } 624 625 /* 626 * Broadcast an ARP request. Caller specifies: 627 * - arp header source ip address 628 * - arp header target ip address 629 * - arp header source ethernet address 630 */ 631 static void 632 arprequest(struct ifnet *ifp, 633 const struct in_addr *sip, const struct in_addr *tip, 634 const uint8_t *enaddr) 635 { 636 struct mbuf *m; 637 struct arphdr *ah; 638 struct sockaddr sa; 639 uint64_t *arps; 640 641 KASSERT(sip != NULL); 642 KASSERT(tip != NULL); 643 KASSERT(enaddr != NULL); 644 645 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 646 return; 647 MCLAIM(m, &arpdomain.dom_mowner); 648 switch (ifp->if_type) { 649 case IFT_IEEE1394: 650 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 651 ifp->if_addrlen; 652 break; 653 default: 654 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 655 2 * ifp->if_addrlen; 656 break; 657 } 658 m->m_pkthdr.len = m->m_len; 659 MH_ALIGN(m, m->m_len); 660 ah = mtod(m, struct arphdr *); 661 memset(ah, 0, m->m_len); 662 switch (ifp->if_type) { 663 case IFT_IEEE1394: /* RFC2734 */ 664 /* fill it now for ar_tpa computation */ 665 ah->ar_hrd = htons(ARPHRD_IEEE1394); 666 break; 667 default: 668 /* ifp->if_output will fill ar_hrd */ 669 break; 670 } 671 ah->ar_pro = htons(ETHERTYPE_IP); 672 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 673 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 674 ah->ar_op = htons(ARPOP_REQUEST); 675 memcpy(ar_sha(ah), enaddr, ah->ar_hln); 676 memcpy(ar_spa(ah), sip, ah->ar_pln); 677 memcpy(ar_tpa(ah), tip, ah->ar_pln); 678 sa.sa_family = AF_ARP; 679 sa.sa_len = 2; 680 m->m_flags |= M_BCAST; 681 arps = ARP_STAT_GETREF(); 682 arps[ARP_STAT_SNDTOTAL]++; 683 arps[ARP_STAT_SENDREQUEST]++; 684 ARP_STAT_PUTREF(); 685 if_output_lock(ifp, ifp, m, &sa, NULL); 686 } 687 688 void 689 arpannounce(struct ifnet *ifp, struct ifaddr *ifa, const uint8_t *enaddr) 690 { 691 struct in_ifaddr *ia = ifatoia(ifa); 692 struct in_addr *ip = &IA_SIN(ifa)->sin_addr; 693 694 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) { 695 ARPLOG(LOG_DEBUG, "%s not ready\n", ARPLOGADDR(ip)); 696 return; 697 } 698 arprequest(ifp, ip, ip, enaddr); 699 } 700 701 static void 702 arpannounce1(struct ifaddr *ifa) 703 { 704 705 arpannounce(ifa->ifa_ifp, ifa, CLLADDR(ifa->ifa_ifp->if_sadl)); 706 } 707 708 /* 709 * Resolve an IP address into an ethernet address. If success, desten is 710 * filled in. If there is no entry in arptab, set one up and broadcast a 711 * request for the IP address. Hold onto this mbuf and resend it once the 712 * address is finally resolved. 713 * 714 * A return value of 0 indicates that desten has been filled in and the packet 715 * should be sent normally; a return value of EWOULDBLOCK indicates that the 716 * packet has been held pending resolution. Any other value indicates an 717 * error. 718 */ 719 int 720 arpresolve(struct ifnet *ifp, const struct rtentry *rt, struct mbuf *m, 721 const struct sockaddr *dst, void *desten, size_t destlen) 722 { 723 struct llentry *la; 724 const char *create_lookup; 725 bool renew; 726 int error; 727 struct ifnet *origifp = ifp; 728 729 #if NCARP > 0 730 if (rt != NULL && rt->rt_ifp->if_type == IFT_CARP) 731 ifp = rt->rt_ifp; 732 #endif 733 734 KASSERT(m != NULL); 735 736 la = arplookup(ifp, NULL, dst, 0); 737 if (la == NULL) 738 goto notfound; 739 740 if ((la->la_flags & LLE_VALID) && 741 ((la->la_flags & LLE_STATIC) || la->la_expire > time_uptime)) { 742 KASSERT(destlen >= ifp->if_addrlen); 743 memcpy(desten, &la->ll_addr, ifp->if_addrlen); 744 LLE_RUNLOCK(la); 745 return 0; 746 } 747 748 notfound: 749 if (ifp->if_flags & IFF_NOARP) { 750 if (la != NULL) 751 LLE_RUNLOCK(la); 752 error = ENOTSUP; 753 goto bad; 754 } 755 756 if (la == NULL) { 757 struct rtentry *_rt; 758 759 create_lookup = "create"; 760 _rt = rtalloc1(dst, 0); 761 IF_AFDATA_WLOCK(ifp); 762 la = lla_create(LLTABLE(ifp), LLE_EXCLUSIVE, dst, _rt); 763 IF_AFDATA_WUNLOCK(ifp); 764 if (_rt != NULL) 765 rt_unref(_rt); 766 if (la == NULL) 767 ARP_STATINC(ARP_STAT_ALLOCFAIL); 768 else { 769 struct sockaddr_in sin; 770 771 arp_init_llentry(ifp, la); 772 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 773 rt_clonedmsg(sintosa(&sin), ifp, rt); 774 } 775 } else if (LLE_TRY_UPGRADE(la) == 0) { 776 create_lookup = "lookup"; 777 LLE_RUNLOCK(la); 778 IF_AFDATA_RLOCK(ifp); 779 la = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst); 780 IF_AFDATA_RUNLOCK(ifp); 781 } 782 783 error = EINVAL; 784 if (la == NULL) { 785 log(LOG_DEBUG, 786 "%s: failed to %s llentry for %s on %s\n", 787 __func__, create_lookup, inet_ntoa(satocsin(dst)->sin_addr), 788 ifp->if_xname); 789 goto bad; 790 } 791 792 if ((la->la_flags & LLE_VALID) && 793 ((la->la_flags & LLE_STATIC) || la->la_expire > time_uptime)) 794 { 795 KASSERT(destlen >= ifp->if_addrlen); 796 memcpy(desten, &la->ll_addr, ifp->if_addrlen); 797 renew = false; 798 /* 799 * If entry has an expiry time and it is approaching, 800 * see if we need to send an ARP request within this 801 * arpt_down interval. 802 */ 803 if (!(la->la_flags & LLE_STATIC) && 804 time_uptime + la->la_preempt > la->la_expire) 805 { 806 renew = true; 807 la->la_preempt--; 808 } 809 810 LLE_WUNLOCK(la); 811 812 if (renew) { 813 const uint8_t *enaddr = CLLADDR(ifp->if_sadl); 814 arprequest(origifp, 815 &satocsin(rt->rt_ifa->ifa_addr)->sin_addr, 816 &satocsin(dst)->sin_addr, enaddr); 817 } 818 819 return 0; 820 } 821 822 if (la->la_flags & LLE_STATIC) { /* should not happen! */ 823 LLE_RUNLOCK(la); 824 log(LOG_DEBUG, "%s: ouch, empty static llinfo for %s\n", 825 __func__, inet_ntoa(satocsin(dst)->sin_addr)); 826 error = EINVAL; 827 goto bad; 828 } 829 830 renew = (la->la_asked == 0 || la->la_expire != time_uptime); 831 832 /* 833 * There is an arptab entry, but no ethernet address 834 * response yet. Add the mbuf to the list, dropping 835 * the oldest packet if we have exceeded the system 836 * setting. 837 */ 838 LLE_WLOCK_ASSERT(la); 839 if (la->la_numheld >= arp_maxhold) { 840 if (la->la_hold != NULL) { 841 struct mbuf *next = la->la_hold->m_nextpkt; 842 m_freem(la->la_hold); 843 la->la_hold = next; 844 la->la_numheld--; 845 ARP_STATINC(ARP_STAT_DFRDROPPED); 846 ARP_STATINC(ARP_STAT_DFRTOTAL); 847 } 848 } 849 if (la->la_hold != NULL) { 850 struct mbuf *curr = la->la_hold; 851 while (curr->m_nextpkt != NULL) 852 curr = curr->m_nextpkt; 853 curr->m_nextpkt = m; 854 } else 855 la->la_hold = m; 856 la->la_numheld++; 857 if (!renew) 858 LLE_DOWNGRADE(la); 859 860 /* 861 * Return EWOULDBLOCK if we have tried less than arp_maxtries. It 862 * will be masked by ether_output(). Return EHOSTDOWN/EHOSTUNREACH 863 * if we have already sent arp_maxtries ARP requests. Retransmit the 864 * ARP request, but not faster than one request per second. 865 */ 866 if (la->la_asked < arp_maxtries) 867 error = EWOULDBLOCK; /* First request. */ 868 else 869 error = (rt != NULL && rt->rt_flags & RTF_GATEWAY) ? 870 EHOSTUNREACH : EHOSTDOWN; 871 872 if (renew) { 873 const uint8_t *enaddr = CLLADDR(ifp->if_sadl); 874 la->la_expire = time_uptime; 875 arp_settimer(la, arpt_down); 876 la->la_asked++; 877 LLE_WUNLOCK(la); 878 879 if (rt != NULL) { 880 arprequest(origifp, 881 &satocsin(rt->rt_ifa->ifa_addr)->sin_addr, 882 &satocsin(dst)->sin_addr, enaddr); 883 } else { 884 struct sockaddr_in sin; 885 struct rtentry *_rt; 886 887 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 888 889 /* XXX */ 890 _rt = rtalloc1((struct sockaddr *)&sin, 0); 891 if (_rt == NULL) 892 goto bad; 893 arprequest(origifp, 894 &satocsin(_rt->rt_ifa->ifa_addr)->sin_addr, 895 &satocsin(dst)->sin_addr, enaddr); 896 rt_unref(_rt); 897 } 898 return error; 899 } 900 901 LLE_RUNLOCK(la); 902 return error; 903 904 bad: 905 m_freem(m); 906 return error; 907 } 908 909 /* 910 * Common length and type checks are done here, 911 * then the protocol-specific routine is called. 912 */ 913 void 914 arpintr(void) 915 { 916 struct mbuf *m; 917 struct arphdr *ar; 918 int s; 919 int arplen; 920 921 SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE(); 922 for (;;) { 923 struct ifnet *rcvif; 924 925 IFQ_LOCK(&arpintrq); 926 IF_DEQUEUE(&arpintrq, m); 927 IFQ_UNLOCK(&arpintrq); 928 if (m == NULL) 929 goto out; 930 if ((m->m_flags & M_PKTHDR) == 0) 931 panic("arpintr"); 932 933 MCLAIM(m, &arpdomain.dom_mowner); 934 ARP_STATINC(ARP_STAT_RCVTOTAL); 935 936 arplen = sizeof(struct arphdr); 937 if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL) 938 goto badlen; 939 ar = mtod(m, struct arphdr *); 940 941 rcvif = m_get_rcvif(m, &s); 942 if (__predict_false(rcvif == NULL)) { 943 ARP_STATINC(ARP_STAT_RCVNOINT); 944 goto free; 945 } 946 947 /* 948 * We don't want non-IEEE1394 ARP packets on IEEE1394 949 * interfaces, and vice versa. Our life depends on that. 950 */ 951 switch (rcvif->if_type) { 952 case IFT_IEEE1394: 953 if (ntohs(ar->ar_hrd) != ARPHRD_IEEE1394) { 954 m_put_rcvif(rcvif, &s); 955 ARP_STATINC(ARP_STAT_RCVBADPROTO); 956 goto free; 957 } 958 959 arplen = sizeof(struct arphdr) + 960 ar->ar_hln + 2 * ar->ar_pln; 961 break; 962 default: 963 if (ntohs(ar->ar_hrd) == ARPHRD_IEEE1394) { 964 m_put_rcvif(rcvif, &s); 965 ARP_STATINC(ARP_STAT_RCVBADPROTO); 966 goto free; 967 } 968 969 arplen = sizeof(struct arphdr) + 970 2 * ar->ar_hln + 2 * ar->ar_pln; 971 break; 972 } 973 974 m_put_rcvif(rcvif, &s); 975 976 if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL) 977 goto badlen; 978 ar = mtod(m, struct arphdr *); 979 980 switch (ntohs(ar->ar_pro)) { 981 case ETHERTYPE_IP: 982 case ETHERTYPE_IPTRAILERS: 983 in_arpinput(m); 984 continue; 985 default: 986 ARP_STATINC(ARP_STAT_RCVBADPROTO); 987 goto free; 988 } 989 990 badlen: 991 ARP_STATINC(ARP_STAT_RCVBADLEN); 992 free: 993 m_freem(m); 994 } 995 996 out: 997 SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 998 return; /* XXX gcc */ 999 } 1000 1001 /* 1002 * ARP for Internet protocols on 10 Mb/s Ethernet. Algorithm is that given in 1003 * RFC 826. In addition, a sanity check is performed on the sender protocol 1004 * address, to catch impersonators. 1005 * 1006 * We no longer handle negotiations for use of trailer protocol: formerly, ARP 1007 * replied for protocol type ETHERTYPE_TRAIL sent along with IP replies if we 1008 * wanted trailers sent to us, and also sent them in response to IP replies. 1009 * This allowed either end to announce the desire to receive trailer packets. 1010 * 1011 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, but 1012 * formerly didn't normally send requests. 1013 */ 1014 static void 1015 in_arpinput(struct mbuf *m) 1016 { 1017 struct arphdr *ah; 1018 struct ifnet *ifp, *rcvif = NULL; 1019 struct llentry *la = NULL; 1020 struct in_ifaddr *ia = NULL; 1021 #if NBRIDGE > 0 1022 struct in_ifaddr *bridge_ia = NULL; 1023 #endif 1024 #if NCARP > 0 1025 uint32_t count = 0, index = 0; 1026 #endif 1027 struct sockaddr sa; 1028 struct in_addr isaddr, itaddr, myaddr; 1029 int op; 1030 void *tha; 1031 uint64_t *arps; 1032 struct psref psref, psref_ia; 1033 int s; 1034 char llabuf[LLA_ADDRSTRLEN]; 1035 char ipbuf[INET_ADDRSTRLEN]; 1036 bool do_dad; 1037 1038 if (__predict_false(m_makewritable(&m, 0, m->m_pkthdr.len, M_DONTWAIT))) 1039 goto out; 1040 ah = mtod(m, struct arphdr *); 1041 op = ntohs(ah->ar_op); 1042 1043 if (ah->ar_pln != sizeof(struct in_addr)) 1044 goto out; 1045 1046 ifp = if_get_bylla(ar_sha(ah), ah->ar_hln, &psref); 1047 if (ifp) { 1048 /* it's from me, ignore it. */ 1049 if_put(ifp, &psref); 1050 ARP_STATINC(ARP_STAT_RCVLOCALSHA); 1051 goto out; 1052 } 1053 1054 rcvif = ifp = m_get_rcvif_psref(m, &psref); 1055 if (__predict_false(rcvif == NULL)) 1056 goto out; 1057 if (rcvif->if_flags & IFF_NOARP) 1058 goto out; 1059 1060 memcpy(&isaddr, ar_spa(ah), sizeof(isaddr)); 1061 memcpy(&itaddr, ar_tpa(ah), sizeof(itaddr)); 1062 1063 if (m->m_flags & (M_BCAST|M_MCAST)) 1064 ARP_STATINC(ARP_STAT_RCVMCAST); 1065 1066 /* 1067 * Search for a matching interface address 1068 * or any address on the interface to use 1069 * as a dummy address in the rest of this function. 1070 * 1071 * If the target IP address is zero then try and find 1072 * the sender address for DAD. 1073 */ 1074 myaddr = in_nullhost(itaddr) ? isaddr : itaddr; 1075 s = pserialize_read_enter(); 1076 IN_ADDRHASH_READER_FOREACH(ia, myaddr.s_addr) { 1077 if (!in_hosteq(ia->ia_addr.sin_addr, myaddr)) 1078 continue; 1079 #if NCARP > 0 1080 if (ia->ia_ifp->if_type == IFT_CARP && 1081 ((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) == 1082 (IFF_UP|IFF_RUNNING))) { 1083 index++; 1084 /* XXX: ar_hln? */ 1085 if (ia->ia_ifp == rcvif && (ah->ar_hln >= 6) && 1086 carp_iamatch(ia, ar_sha(ah), 1087 &count, index)) { 1088 break; 1089 } 1090 } else 1091 #endif 1092 if (ia->ia_ifp == rcvif) 1093 break; 1094 #if NBRIDGE > 0 1095 /* 1096 * If the interface we received the packet on 1097 * is part of a bridge, check to see if we need 1098 * to "bridge" the packet to ourselves at this 1099 * layer. Note we still prefer a perfect match, 1100 * but allow this weaker match if necessary. 1101 */ 1102 if (rcvif->if_bridge != NULL && 1103 rcvif->if_bridge == ia->ia_ifp->if_bridge) 1104 bridge_ia = ia; 1105 #endif 1106 } 1107 1108 #if NBRIDGE > 0 1109 if (ia == NULL && bridge_ia != NULL) { 1110 ia = bridge_ia; 1111 m_put_rcvif_psref(rcvif, &psref); 1112 rcvif = NULL; 1113 /* FIXME */ 1114 ifp = bridge_ia->ia_ifp; 1115 } 1116 #endif 1117 if (ia != NULL) 1118 ia4_acquire(ia, &psref_ia); 1119 pserialize_read_exit(s); 1120 1121 if (ah->ar_hln != ifp->if_addrlen) { 1122 ARP_STATINC(ARP_STAT_RCVBADLEN); 1123 log(LOG_WARNING, 1124 "arp from %s: addr len: new %d, i/f %d (ignored)\n", 1125 IN_PRINT(ipbuf, &isaddr), ah->ar_hln, ifp->if_addrlen); 1126 goto out; 1127 } 1128 1129 /* Only do DaD if we have a matching address. */ 1130 do_dad = (ia != NULL); 1131 1132 if (ia == NULL) { 1133 ia = in_get_ia_on_iface_psref(isaddr, rcvif, &psref_ia); 1134 if (ia == NULL) { 1135 ia = in_get_ia_from_ifp_psref(ifp, &psref_ia); 1136 if (ia == NULL) { 1137 ARP_STATINC(ARP_STAT_RCVNOINT); 1138 goto out; 1139 } 1140 } 1141 } 1142 1143 myaddr = ia->ia_addr.sin_addr; 1144 1145 /* XXX checks for bridge case? */ 1146 if (!memcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 1147 ARP_STATINC(ARP_STAT_RCVBCASTSHA); 1148 log(LOG_ERR, 1149 "%s: arp: link address is broadcast for IP address %s!\n", 1150 ifp->if_xname, IN_PRINT(ipbuf, &isaddr)); 1151 goto out; 1152 } 1153 1154 /* 1155 * If the source IP address is zero, this is an RFC 5227 ARP probe 1156 */ 1157 if (in_nullhost(isaddr)) 1158 ARP_STATINC(ARP_STAT_RCVZEROSPA); 1159 else if (in_hosteq(isaddr, myaddr)) 1160 ARP_STATINC(ARP_STAT_RCVLOCALSPA); 1161 1162 if (in_nullhost(itaddr)) 1163 ARP_STATINC(ARP_STAT_RCVZEROTPA); 1164 1165 /* 1166 * DAD check, RFC 5227. 1167 * Collision on sender address is always a duplicate. 1168 * Collision on target address is only a duplicate IF 1169 * the sender address is the null host (ie a DAD probe) AND 1170 * our address is in the TENTATIVE state. 1171 * DUPLICATED state is also checked so that processing stops here 1172 * and an error can be logged. 1173 */ 1174 if (do_dad && 1175 (in_hosteq(isaddr, myaddr) || 1176 (in_nullhost(isaddr) && in_hosteq(itaddr, myaddr) 1177 && ia->ia4_flags & (IN_IFF_TENTATIVE | IN_IFF_DUPLICATED)))) 1178 { 1179 arp_dad_duplicated((struct ifaddr *)ia, 1180 lla_snprintf(llabuf, ar_sha(ah), ah->ar_hln)); 1181 goto out; 1182 } 1183 1184 /* 1185 * If the target IP address is zero, ignore the packet. 1186 * This prevents the code below from trying to answer 1187 * when we are using IP address zero (booting). 1188 */ 1189 if (in_nullhost(itaddr)) 1190 goto out; 1191 1192 if (in_nullhost(isaddr)) 1193 goto reply; 1194 1195 if (in_hosteq(itaddr, myaddr)) 1196 la = arpcreate(ifp, &isaddr, NULL, 1); 1197 else 1198 la = arplookup(ifp, &isaddr, NULL, 1); 1199 if (la == NULL) 1200 goto reply; 1201 1202 if ((la->la_flags & LLE_VALID) && 1203 memcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) { 1204 if (la->la_flags & LLE_STATIC) { 1205 ARP_STATINC(ARP_STAT_RCVOVERPERM); 1206 if (!log_permanent_modify) 1207 goto out; 1208 log(LOG_INFO, 1209 "%s tried to overwrite permanent arp info" 1210 " for %s\n", 1211 lla_snprintf(llabuf, ar_sha(ah), ah->ar_hln), 1212 IN_PRINT(ipbuf, &isaddr)); 1213 goto out; 1214 } else if (la->lle_tbl->llt_ifp != ifp) { 1215 /* XXX should not happen? */ 1216 ARP_STATINC(ARP_STAT_RCVOVERINT); 1217 if (!log_wrong_iface) 1218 goto out; 1219 log(LOG_INFO, 1220 "%s on %s tried to overwrite " 1221 "arp info for %s on %s\n", 1222 lla_snprintf(llabuf, ar_sha(ah), ah->ar_hln), 1223 ifp->if_xname, IN_PRINT(ipbuf, &isaddr), 1224 la->lle_tbl->llt_ifp->if_xname); 1225 goto out; 1226 } else { 1227 ARP_STATINC(ARP_STAT_RCVOVER); 1228 if (log_movements) 1229 log(LOG_INFO, "arp info overwritten " 1230 "for %s by %s\n", 1231 IN_PRINT(ipbuf, &isaddr), 1232 lla_snprintf(llabuf, ar_sha(ah), 1233 ah->ar_hln)); 1234 } 1235 } 1236 1237 KASSERT(ifp->if_sadl->sdl_alen == ifp->if_addrlen); 1238 1239 #if NTOKEN > 0 1240 /* 1241 * XXX uses m_data and assumes the complete answer including 1242 * XXX token-ring headers is in the same buf 1243 */ 1244 if (ifp->if_type == IFT_ISO88025) { 1245 struct token_header *trh; 1246 1247 trh = (struct token_header *)M_TRHSTART(m); 1248 if (trh->token_shost[0] & TOKEN_RI_PRESENT) { 1249 struct token_rif *rif; 1250 size_t riflen; 1251 1252 rif = TOKEN_RIF(trh); 1253 riflen = (ntohs(rif->tr_rcf) & 1254 TOKEN_RCF_LEN_MASK) >> 8; 1255 1256 if (riflen > 2 && 1257 riflen < sizeof(struct token_rif) && 1258 (riflen & 1) == 0) { 1259 rif->tr_rcf ^= htons(TOKEN_RCF_DIRECTION); 1260 rif->tr_rcf &= htons(~TOKEN_RCF_BROADCAST_MASK); 1261 memcpy(TOKEN_RIF_LLE(la), rif, riflen); 1262 } 1263 } 1264 } 1265 #endif 1266 1267 KASSERT(sizeof(la->ll_addr) >= ifp->if_addrlen); 1268 memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen); 1269 la->la_flags |= LLE_VALID; 1270 if ((la->la_flags & LLE_STATIC) == 0) { 1271 la->la_expire = time_uptime + arpt_keep; 1272 arp_settimer(la, arpt_keep); 1273 } 1274 la->la_asked = 0; 1275 /* rt->rt_flags &= ~RTF_REJECT; */ 1276 1277 if (la->la_hold != NULL) { 1278 int n = la->la_numheld; 1279 struct mbuf *m_hold, *m_hold_next; 1280 struct sockaddr_in sin; 1281 1282 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 1283 1284 m_hold = la->la_hold; 1285 la->la_hold = NULL; 1286 la->la_numheld = 0; 1287 /* 1288 * We have to unlock here because if_output would call 1289 * arpresolve 1290 */ 1291 LLE_WUNLOCK(la); 1292 ARP_STATADD(ARP_STAT_DFRSENT, n); 1293 ARP_STATADD(ARP_STAT_DFRTOTAL, n); 1294 for (; m_hold != NULL; m_hold = m_hold_next) { 1295 m_hold_next = m_hold->m_nextpkt; 1296 m_hold->m_nextpkt = NULL; 1297 if_output_lock(ifp, ifp, m_hold, sintosa(&sin), NULL); 1298 } 1299 } else 1300 LLE_WUNLOCK(la); 1301 la = NULL; 1302 1303 reply: 1304 if (la != NULL) { 1305 LLE_WUNLOCK(la); 1306 la = NULL; 1307 } 1308 if (op != ARPOP_REQUEST) { 1309 if (op == ARPOP_REPLY) 1310 ARP_STATINC(ARP_STAT_RCVREPLY); 1311 goto out; 1312 } 1313 ARP_STATINC(ARP_STAT_RCVREQUEST); 1314 if (in_hosteq(itaddr, myaddr)) { 1315 /* If our address is unusable, don't reply */ 1316 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) 1317 goto out; 1318 /* I am the target */ 1319 tha = ar_tha(ah); 1320 if (tha) 1321 memcpy(tha, ar_sha(ah), ah->ar_hln); 1322 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1323 } else { 1324 /* Proxy ARP */ 1325 struct llentry *lle = NULL; 1326 struct sockaddr_in sin; 1327 1328 #if NCARP > 0 1329 if (ifp->if_type == IFT_CARP) { 1330 struct ifnet *_rcvif = m_get_rcvif(m, &s); 1331 int iftype = 0; 1332 if (__predict_true(_rcvif != NULL)) 1333 iftype = _rcvif->if_type; 1334 m_put_rcvif(_rcvif, &s); 1335 if (iftype != IFT_CARP) 1336 goto out; 1337 } 1338 #endif 1339 1340 tha = ar_tha(ah); 1341 1342 sockaddr_in_init(&sin, &itaddr, 0); 1343 1344 IF_AFDATA_RLOCK(ifp); 1345 lle = lla_lookup(LLTABLE(ifp), 0, (struct sockaddr *)&sin); 1346 IF_AFDATA_RUNLOCK(ifp); 1347 1348 if ((lle != NULL) && (lle->la_flags & LLE_PUB)) { 1349 if (tha) 1350 memcpy(tha, ar_sha(ah), ah->ar_hln); 1351 memcpy(ar_sha(ah), &lle->ll_addr, ah->ar_hln); 1352 LLE_RUNLOCK(lle); 1353 } else { 1354 if (lle != NULL) 1355 LLE_RUNLOCK(lle); 1356 goto out; 1357 } 1358 } 1359 ia4_release(ia, &psref_ia); 1360 1361 /* 1362 * XXX XXX: Here we're recycling the mbuf. But the mbuf could have 1363 * other mbufs in its chain, and just overwriting m->m_pkthdr.len 1364 * would be wrong in this case (the length becomes smaller than the 1365 * real chain size). 1366 * 1367 * This can theoretically cause bugs in the lower layers (drivers, 1368 * and L2encap), in some corner cases. 1369 */ 1370 memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); 1371 memcpy(ar_spa(ah), &itaddr, ah->ar_pln); 1372 ah->ar_op = htons(ARPOP_REPLY); 1373 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 1374 switch (ifp->if_type) { 1375 case IFT_IEEE1394: 1376 /* ieee1394 arp reply is broadcast */ 1377 m->m_flags &= ~M_MCAST; 1378 m->m_flags |= M_BCAST; 1379 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + ah->ar_hln; 1380 break; 1381 default: 1382 m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */ 1383 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); 1384 break; 1385 } 1386 m->m_pkthdr.len = m->m_len; 1387 sa.sa_family = AF_ARP; 1388 sa.sa_len = 2; 1389 arps = ARP_STAT_GETREF(); 1390 arps[ARP_STAT_SNDTOTAL]++; 1391 arps[ARP_STAT_SNDREPLY]++; 1392 ARP_STAT_PUTREF(); 1393 if_output_lock(ifp, ifp, m, &sa, NULL); 1394 if (rcvif != NULL) 1395 m_put_rcvif_psref(rcvif, &psref); 1396 return; 1397 1398 out: 1399 if (la != NULL) 1400 LLE_WUNLOCK(la); 1401 if (ia != NULL) 1402 ia4_release(ia, &psref_ia); 1403 if (rcvif != NULL) 1404 m_put_rcvif_psref(rcvif, &psref); 1405 m_freem(m); 1406 } 1407 1408 /* 1409 * Lookup or a new address in arptab. 1410 */ 1411 static struct llentry * 1412 arplookup(struct ifnet *ifp, const struct in_addr *addr, 1413 const struct sockaddr *sa, int wlock) 1414 { 1415 struct sockaddr_in sin; 1416 struct llentry *la; 1417 int flags = wlock ? LLE_EXCLUSIVE : 0; 1418 1419 if (sa == NULL) { 1420 KASSERT(addr != NULL); 1421 sockaddr_in_init(&sin, addr, 0); 1422 sa = sintocsa(&sin); 1423 } 1424 1425 IF_AFDATA_RLOCK(ifp); 1426 la = lla_lookup(LLTABLE(ifp), flags, sa); 1427 IF_AFDATA_RUNLOCK(ifp); 1428 1429 return la; 1430 } 1431 1432 static struct llentry * 1433 arpcreate(struct ifnet *ifp, const struct in_addr *addr, 1434 const struct sockaddr *sa, int wlock) 1435 { 1436 struct sockaddr_in sin; 1437 struct llentry *la; 1438 int flags = wlock ? LLE_EXCLUSIVE : 0; 1439 1440 if (sa == NULL) { 1441 KASSERT(addr != NULL); 1442 sockaddr_in_init(&sin, addr, 0); 1443 sa = sintocsa(&sin); 1444 } 1445 1446 la = arplookup(ifp, addr, sa, wlock); 1447 1448 if (la == NULL) { 1449 struct rtentry *rt; 1450 1451 rt = rtalloc1(sa, 0); 1452 IF_AFDATA_WLOCK(ifp); 1453 la = lla_create(LLTABLE(ifp), flags, sa, rt); 1454 IF_AFDATA_WUNLOCK(ifp); 1455 if (rt != NULL) 1456 rt_unref(rt); 1457 1458 if (la != NULL) 1459 arp_init_llentry(ifp, la); 1460 } 1461 1462 return la; 1463 } 1464 1465 int 1466 arpioctl(u_long cmd, void *data) 1467 { 1468 1469 return EOPNOTSUPP; 1470 } 1471 1472 void 1473 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1474 { 1475 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1476 1477 ifa->ifa_rtrequest = arp_rtrequest; 1478 ifa->ifa_flags |= RTF_CONNECTED; 1479 1480 /* ARP will handle DAD for this address. */ 1481 if (in_nullhost(IA_SIN(ifa)->sin_addr)) { 1482 if (ia->ia_dad_stop != NULL) /* safety */ 1483 ia->ia_dad_stop(ifa); 1484 ia->ia_dad_start = NULL; 1485 ia->ia_dad_stop = NULL; 1486 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1487 } else { 1488 ia->ia_dad_start = arp_dad_start; 1489 ia->ia_dad_stop = arp_dad_stop; 1490 if (ia->ia4_flags & IN_IFF_TRYTENTATIVE && ip_dad_count > 0) 1491 ia->ia4_flags |= IN_IFF_TENTATIVE; 1492 else 1493 arpannounce1(ifa); 1494 } 1495 } 1496 1497 TAILQ_HEAD(dadq_head, dadq); 1498 struct dadq { 1499 TAILQ_ENTRY(dadq) dad_list; 1500 struct ifaddr *dad_ifa; 1501 int dad_count; /* max ARP to send */ 1502 int dad_arp_tcount; /* # of trials to send ARP */ 1503 int dad_arp_ocount; /* ARP sent so far */ 1504 int dad_arp_announce; /* max ARP announcements */ 1505 int dad_arp_acount; /* # of announcements */ 1506 struct callout dad_timer_ch; 1507 }; 1508 1509 static struct dadq_head dadq; 1510 static int dad_init = 0; 1511 static int dad_maxtry = 15; /* max # of *tries* to transmit DAD packet */ 1512 static kmutex_t arp_dad_lock; 1513 1514 static struct dadq * 1515 arp_dad_find(struct ifaddr *ifa) 1516 { 1517 struct dadq *dp; 1518 1519 KASSERT(mutex_owned(&arp_dad_lock)); 1520 1521 TAILQ_FOREACH(dp, &dadq, dad_list) { 1522 if (dp->dad_ifa == ifa) 1523 return dp; 1524 } 1525 return NULL; 1526 } 1527 1528 static void 1529 arp_dad_starttimer(struct dadq *dp, int ticks) 1530 { 1531 1532 callout_reset(&dp->dad_timer_ch, ticks, 1533 (void (*)(void *))arp_dad_timer, dp); 1534 } 1535 1536 static void 1537 arp_dad_stoptimer(struct dadq *dp) 1538 { 1539 1540 KASSERT(mutex_owned(&arp_dad_lock)); 1541 1542 TAILQ_REMOVE(&dadq, dp, dad_list); 1543 /* Tell the timer that dp is being destroyed. */ 1544 dp->dad_ifa = NULL; 1545 callout_halt(&dp->dad_timer_ch, &arp_dad_lock); 1546 } 1547 1548 static void 1549 arp_dad_destroytimer(struct dadq *dp) 1550 { 1551 1552 callout_destroy(&dp->dad_timer_ch); 1553 KASSERT(dp->dad_ifa == NULL); 1554 kmem_intr_free(dp, sizeof(*dp)); 1555 } 1556 1557 static void 1558 arp_dad_output(struct dadq *dp, struct ifaddr *ifa) 1559 { 1560 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1561 struct ifnet *ifp = ifa->ifa_ifp; 1562 struct in_addr sip; 1563 1564 dp->dad_arp_tcount++; 1565 if ((ifp->if_flags & IFF_UP) == 0) 1566 return; 1567 if ((ifp->if_flags & IFF_RUNNING) == 0) 1568 return; 1569 1570 dp->dad_arp_tcount = 0; 1571 dp->dad_arp_ocount++; 1572 1573 memset(&sip, 0, sizeof(sip)); 1574 arprequest(ifa->ifa_ifp, &sip, &ia->ia_addr.sin_addr, 1575 CLLADDR(ifa->ifa_ifp->if_sadl)); 1576 } 1577 1578 /* 1579 * Start Duplicate Address Detection (DAD) for specified interface address. 1580 */ 1581 static void 1582 arp_dad_start(struct ifaddr *ifa) 1583 { 1584 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1585 struct dadq *dp; 1586 char ipbuf[INET_ADDRSTRLEN]; 1587 1588 if (!dad_init) { 1589 TAILQ_INIT(&dadq); 1590 mutex_init(&arp_dad_lock, MUTEX_DEFAULT, IPL_NONE); 1591 dad_init++; 1592 } 1593 1594 /* 1595 * If we don't need DAD, don't do it. 1596 * - DAD is disabled (ip_dad_count == 0) 1597 */ 1598 if (!(ia->ia4_flags & IN_IFF_TENTATIVE)) { 1599 log(LOG_DEBUG, 1600 "%s: called with non-tentative address %s(%s)\n", __func__, 1601 IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1602 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1603 return; 1604 } 1605 if (!ip_dad_count) { 1606 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1607 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1608 arpannounce1(ifa); 1609 return; 1610 } 1611 KASSERT(ifa->ifa_ifp != NULL); 1612 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) 1613 return; 1614 1615 dp = kmem_intr_alloc(sizeof(*dp), KM_NOSLEEP); 1616 1617 mutex_enter(&arp_dad_lock); 1618 if (arp_dad_find(ifa) != NULL) { 1619 mutex_exit(&arp_dad_lock); 1620 /* DAD already in progress */ 1621 if (dp != NULL) 1622 kmem_intr_free(dp, sizeof(*dp)); 1623 return; 1624 } 1625 1626 if (dp == NULL) { 1627 mutex_exit(&arp_dad_lock); 1628 log(LOG_ERR, "%s: memory allocation failed for %s(%s)\n", 1629 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1630 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1631 return; 1632 } 1633 1634 /* 1635 * Send ARP packet for DAD, ip_dad_count times. 1636 * Note that we must delay the first transmission. 1637 */ 1638 callout_init(&dp->dad_timer_ch, CALLOUT_MPSAFE); 1639 dp->dad_ifa = ifa; 1640 ifaref(ifa); /* just for safety */ 1641 dp->dad_count = ip_dad_count; 1642 dp->dad_arp_announce = 0; /* Will be set when starting to announce */ 1643 dp->dad_arp_acount = dp->dad_arp_ocount = dp->dad_arp_tcount = 0; 1644 TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list); 1645 1646 ARPLOG(LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1647 ARPLOGADDR(&ia->ia_addr.sin_addr)); 1648 1649 arp_dad_starttimer(dp, cprng_fast32() % (PROBE_WAIT * hz)); 1650 1651 mutex_exit(&arp_dad_lock); 1652 } 1653 1654 /* 1655 * terminate DAD unconditionally. used for address removals. 1656 */ 1657 static void 1658 arp_dad_stop(struct ifaddr *ifa) 1659 { 1660 struct dadq *dp; 1661 1662 if (!dad_init) 1663 return; 1664 1665 mutex_enter(&arp_dad_lock); 1666 dp = arp_dad_find(ifa); 1667 if (dp == NULL) { 1668 mutex_exit(&arp_dad_lock); 1669 /* DAD wasn't started yet */ 1670 return; 1671 } 1672 1673 arp_dad_stoptimer(dp); 1674 1675 mutex_exit(&arp_dad_lock); 1676 1677 arp_dad_destroytimer(dp); 1678 ifafree(ifa); 1679 } 1680 1681 static void 1682 arp_dad_timer(struct dadq *dp) 1683 { 1684 struct ifaddr *ifa; 1685 struct in_ifaddr *ia; 1686 char ipbuf[INET_ADDRSTRLEN]; 1687 bool need_free = false; 1688 1689 KERNEL_LOCK_UNLESS_NET_MPSAFE(); 1690 mutex_enter(&arp_dad_lock); 1691 1692 ifa = dp->dad_ifa; 1693 if (ifa == NULL) { 1694 /* dp is being destroyed by someone. Do nothing. */ 1695 goto done; 1696 } 1697 1698 ia = (struct in_ifaddr *)ifa; 1699 if (ia->ia4_flags & IN_IFF_DUPLICATED) { 1700 log(LOG_ERR, "%s: called with duplicate address %s(%s)\n", 1701 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1702 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1703 goto done; 1704 } 1705 if ((ia->ia4_flags & IN_IFF_TENTATIVE) == 0 && dp->dad_arp_acount == 0) 1706 { 1707 log(LOG_ERR, "%s: called with non-tentative address %s(%s)\n", 1708 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1709 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1710 goto done; 1711 } 1712 1713 /* timeouted with IFF_{RUNNING,UP} check */ 1714 if (dp->dad_arp_tcount > dad_maxtry) { 1715 ARPLOG(LOG_INFO, "%s: could not run DAD, driver problem?\n", 1716 if_name(ifa->ifa_ifp)); 1717 1718 arp_dad_stoptimer(dp); 1719 need_free = true; 1720 goto done; 1721 } 1722 1723 /* Need more checks? */ 1724 if (dp->dad_arp_ocount < dp->dad_count) { 1725 int adelay; 1726 1727 /* 1728 * We have more ARP to go. Send ARP packet for DAD. 1729 */ 1730 arp_dad_output(dp, ifa); 1731 if (dp->dad_arp_ocount < dp->dad_count) 1732 adelay = (PROBE_MIN * hz) + 1733 (cprng_fast32() % 1734 ((PROBE_MAX * hz) - (PROBE_MIN * hz))); 1735 else 1736 adelay = ANNOUNCE_WAIT * hz; 1737 arp_dad_starttimer(dp, adelay); 1738 goto done; 1739 } else if (dp->dad_arp_acount == 0) { 1740 /* 1741 * We are done with DAD. 1742 * No duplicate address found. 1743 */ 1744 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1745 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1746 ARPLOG(LOG_DEBUG, 1747 "%s: DAD complete for %s - no duplicates found\n", 1748 if_name(ifa->ifa_ifp), ARPLOGADDR(&ia->ia_addr.sin_addr)); 1749 dp->dad_arp_announce = ANNOUNCE_NUM; 1750 goto announce; 1751 } else if (dp->dad_arp_acount < dp->dad_arp_announce) { 1752 announce: 1753 /* 1754 * Announce the address. 1755 */ 1756 arpannounce1(ifa); 1757 dp->dad_arp_acount++; 1758 if (dp->dad_arp_acount < dp->dad_arp_announce) { 1759 arp_dad_starttimer(dp, ANNOUNCE_INTERVAL * hz); 1760 goto done; 1761 } 1762 ARPLOG(LOG_DEBUG, 1763 "%s: ARP announcement complete for %s\n", 1764 if_name(ifa->ifa_ifp), ARPLOGADDR(&ia->ia_addr.sin_addr)); 1765 } 1766 1767 arp_dad_stoptimer(dp); 1768 need_free = true; 1769 done: 1770 mutex_exit(&arp_dad_lock); 1771 1772 if (need_free) { 1773 arp_dad_destroytimer(dp); 1774 KASSERT(ifa != NULL); 1775 ifafree(ifa); 1776 } 1777 1778 KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 1779 } 1780 1781 static void 1782 arp_dad_duplicated(struct ifaddr *ifa, const char *sha) 1783 { 1784 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1785 struct ifnet *ifp = ifa->ifa_ifp; 1786 char ipbuf[INET_ADDRSTRLEN]; 1787 const char *iastr; 1788 1789 iastr = IN_PRINT(ipbuf, &ia->ia_addr.sin_addr); 1790 1791 if (ia->ia4_flags & (IN_IFF_TENTATIVE|IN_IFF_DUPLICATED)) { 1792 log(LOG_ERR, 1793 "%s: DAD duplicate address %s from %s\n", 1794 if_name(ifp), iastr, sha); 1795 } else if (ia->ia_dad_defended == 0 || 1796 ia->ia_dad_defended < time_uptime - DEFEND_INTERVAL) { 1797 ia->ia_dad_defended = time_uptime; 1798 arpannounce1(ifa); 1799 log(LOG_ERR, 1800 "%s: DAD defended address %s from %s\n", 1801 if_name(ifp), iastr, sha); 1802 return; 1803 } else { 1804 /* If DAD is disabled, just report the duplicate. */ 1805 if (ip_dad_count == 0) { 1806 log(LOG_ERR, 1807 "%s: DAD ignoring duplicate address %s from %s\n", 1808 if_name(ifp), iastr, sha); 1809 return; 1810 } 1811 log(LOG_ERR, 1812 "%s: DAD defence failed for %s from %s\n", 1813 if_name(ifp), iastr, sha); 1814 } 1815 1816 arp_dad_stop(ifa); 1817 1818 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1819 if ((ia->ia4_flags & IN_IFF_DUPLICATED) == 0) { 1820 ia->ia4_flags |= IN_IFF_DUPLICATED; 1821 /* Inform the routing socket of the duplicate address */ 1822 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1823 } 1824 } 1825 1826 /* 1827 * Called from 10 Mb/s Ethernet interrupt handlers 1828 * when ether packet type ETHERTYPE_REVARP 1829 * is received. Common length and type checks are done here, 1830 * then the protocol-specific routine is called. 1831 */ 1832 void 1833 revarpinput(struct mbuf *m) 1834 { 1835 struct arphdr *ar; 1836 int arplen; 1837 1838 arplen = sizeof(struct arphdr); 1839 if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL) 1840 return; 1841 ar = mtod(m, struct arphdr *); 1842 1843 if (ntohs(ar->ar_hrd) == ARPHRD_IEEE1394) { 1844 goto out; 1845 } 1846 1847 arplen = sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln); 1848 if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL) 1849 return; 1850 ar = mtod(m, struct arphdr *); 1851 1852 switch (ntohs(ar->ar_pro)) { 1853 case ETHERTYPE_IP: 1854 case ETHERTYPE_IPTRAILERS: 1855 in_revarpinput(m); 1856 return; 1857 1858 default: 1859 break; 1860 } 1861 1862 out: 1863 m_freem(m); 1864 } 1865 1866 /* 1867 * RARP for Internet protocols on 10 Mb/s Ethernet. 1868 * Algorithm is that given in RFC 903. 1869 * We are only using for bootstrap purposes to get an ip address for one of 1870 * our interfaces. Thus we support no user-interface. 1871 * 1872 * Since the contents of the RARP reply are specific to the interface that 1873 * sent the request, this code must ensure that they are properly associated. 1874 * 1875 * Note: also supports ARP via RARP packets, per the RFC. 1876 */ 1877 void 1878 in_revarpinput(struct mbuf *m) 1879 { 1880 struct arphdr *ah; 1881 void *tha; 1882 int op; 1883 struct ifnet *rcvif; 1884 int s; 1885 1886 ah = mtod(m, struct arphdr *); 1887 op = ntohs(ah->ar_op); 1888 1889 rcvif = m_get_rcvif(m, &s); 1890 if (__predict_false(rcvif == NULL)) 1891 goto out; 1892 if (rcvif->if_flags & IFF_NOARP) 1893 goto out; 1894 1895 switch (rcvif->if_type) { 1896 case IFT_IEEE1394: 1897 /* ARP without target hardware address is not supported */ 1898 goto out; 1899 default: 1900 break; 1901 } 1902 1903 switch (op) { 1904 case ARPOP_REQUEST: 1905 case ARPOP_REPLY: /* per RFC */ 1906 m_put_rcvif(rcvif, &s); 1907 in_arpinput(m); 1908 return; 1909 case ARPOP_REVREPLY: 1910 break; 1911 case ARPOP_REVREQUEST: /* handled by rarpd(8) */ 1912 default: 1913 goto out; 1914 } 1915 if (!revarp_in_progress) 1916 goto out; 1917 if (rcvif != myip_ifp) /* !same interface */ 1918 goto out; 1919 if (myip_initialized) 1920 goto wake; 1921 tha = ar_tha(ah); 1922 if (tha == NULL) 1923 goto out; 1924 if (ah->ar_pln != sizeof(struct in_addr)) 1925 goto out; 1926 if (ah->ar_hln != rcvif->if_sadl->sdl_alen) 1927 goto out; 1928 if (memcmp(tha, CLLADDR(rcvif->if_sadl), rcvif->if_sadl->sdl_alen)) 1929 goto out; 1930 memcpy(&srv_ip, ar_spa(ah), sizeof(srv_ip)); 1931 memcpy(&myip, ar_tpa(ah), sizeof(myip)); 1932 myip_initialized = 1; 1933 wake: /* Do wakeup every time in case it was missed. */ 1934 wakeup((void *)&myip); 1935 1936 out: 1937 m_put_rcvif(rcvif, &s); 1938 m_freem(m); 1939 } 1940 1941 /* 1942 * Send a RARP request for the ip address of the specified interface. 1943 * The request should be RFC 903-compliant. 1944 */ 1945 static void 1946 revarprequest(struct ifnet *ifp) 1947 { 1948 struct sockaddr sa; 1949 struct mbuf *m; 1950 struct arphdr *ah; 1951 void *tha; 1952 1953 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 1954 return; 1955 MCLAIM(m, &arpdomain.dom_mowner); 1956 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) + 1957 2*ifp->if_addrlen; 1958 m->m_pkthdr.len = m->m_len; 1959 MH_ALIGN(m, m->m_len); 1960 ah = mtod(m, struct arphdr *); 1961 memset(ah, 0, m->m_len); 1962 ah->ar_pro = htons(ETHERTYPE_IP); 1963 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 1964 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 1965 ah->ar_op = htons(ARPOP_REVREQUEST); 1966 1967 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1968 tha = ar_tha(ah); 1969 if (tha == NULL) { 1970 m_free(m); 1971 return; 1972 } 1973 memcpy(tha, CLLADDR(ifp->if_sadl), ah->ar_hln); 1974 1975 sa.sa_family = AF_ARP; 1976 sa.sa_len = 2; 1977 m->m_flags |= M_BCAST; 1978 1979 if_output_lock(ifp, ifp, m, &sa, NULL); 1980 } 1981 1982 /* 1983 * RARP for the ip address of the specified interface, but also 1984 * save the ip address of the server that sent the answer. 1985 * Timeout if no response is received. 1986 */ 1987 int 1988 revarpwhoarewe(struct ifnet *ifp, struct in_addr *serv_in, 1989 struct in_addr *clnt_in) 1990 { 1991 int result, count = 20; 1992 1993 myip_initialized = 0; 1994 myip_ifp = ifp; 1995 1996 revarp_in_progress = 1; 1997 while (count--) { 1998 revarprequest(ifp); 1999 result = tsleep((void *)&myip, PSOCK, "revarp", hz/2); 2000 if (result != EWOULDBLOCK) 2001 break; 2002 } 2003 revarp_in_progress = 0; 2004 2005 if (!myip_initialized) 2006 return ENETUNREACH; 2007 2008 memcpy(serv_in, &srv_ip, sizeof(*serv_in)); 2009 memcpy(clnt_in, &myip, sizeof(*clnt_in)); 2010 return 0; 2011 } 2012 2013 void 2014 arp_stat_add(int type, uint64_t count) 2015 { 2016 ARP_STATADD(type, count); 2017 } 2018 2019 static int 2020 sysctl_net_inet_arp_stats(SYSCTLFN_ARGS) 2021 { 2022 2023 return NETSTAT_SYSCTL(arpstat_percpu, ARP_NSTATS); 2024 } 2025 2026 static void 2027 sysctl_net_inet_arp_setup(struct sysctllog **clog) 2028 { 2029 const struct sysctlnode *node; 2030 2031 sysctl_createv(clog, 0, NULL, NULL, 2032 CTLFLAG_PERMANENT, 2033 CTLTYPE_NODE, "inet", NULL, 2034 NULL, 0, NULL, 0, 2035 CTL_NET, PF_INET, CTL_EOL); 2036 sysctl_createv(clog, 0, NULL, &node, 2037 CTLFLAG_PERMANENT, 2038 CTLTYPE_NODE, "arp", 2039 SYSCTL_DESCR("Address Resolution Protocol"), 2040 NULL, 0, NULL, 0, 2041 CTL_NET, PF_INET, CTL_CREATE, CTL_EOL); 2042 2043 sysctl_createv(clog, 0, NULL, NULL, 2044 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2045 CTLTYPE_INT, "keep", 2046 SYSCTL_DESCR("Valid ARP entry lifetime in seconds"), 2047 NULL, 0, &arpt_keep, 0, 2048 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2049 2050 sysctl_createv(clog, 0, NULL, NULL, 2051 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2052 CTLTYPE_INT, "down", 2053 SYSCTL_DESCR("Failed ARP entry lifetime in seconds"), 2054 NULL, 0, &arpt_down, 0, 2055 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2056 2057 sysctl_createv(clog, 0, NULL, NULL, 2058 CTLFLAG_PERMANENT, 2059 CTLTYPE_STRUCT, "stats", 2060 SYSCTL_DESCR("ARP statistics"), 2061 sysctl_net_inet_arp_stats, 0, NULL, 0, 2062 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2063 2064 sysctl_createv(clog, 0, NULL, NULL, 2065 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2066 CTLTYPE_INT, "log_movements", 2067 SYSCTL_DESCR("log ARP replies from MACs different than" 2068 " the one in the cache"), 2069 NULL, 0, &log_movements, 0, 2070 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2071 2072 sysctl_createv(clog, 0, NULL, NULL, 2073 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2074 CTLTYPE_INT, "log_permanent_modify", 2075 SYSCTL_DESCR("log ARP replies from MACs different than" 2076 " the one in the permanent arp entry"), 2077 NULL, 0, &log_permanent_modify, 0, 2078 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2079 2080 sysctl_createv(clog, 0, NULL, NULL, 2081 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2082 CTLTYPE_INT, "log_wrong_iface", 2083 SYSCTL_DESCR("log ARP packets arriving on the wrong" 2084 " interface"), 2085 NULL, 0, &log_wrong_iface, 0, 2086 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2087 2088 sysctl_createv(clog, 0, NULL, NULL, 2089 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2090 CTLTYPE_INT, "log_unknown_network", 2091 SYSCTL_DESCR("log ARP packets from non-local network"), 2092 NULL, 0, &log_unknown_network, 0, 2093 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2094 2095 sysctl_createv(clog, 0, NULL, NULL, 2096 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2097 CTLTYPE_INT, "debug", 2098 SYSCTL_DESCR("Enable ARP DAD debug output"), 2099 NULL, 0, &arp_debug, 0, 2100 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2101 } 2102 2103 #endif /* INET */ 2104