1 /* $NetBSD: if_arp.c,v 1.255 2017/11/17 07:37:12 ozaki-r Exp $ */ 2 3 /*- 4 * Copyright (c) 1998, 2000, 2008 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Public Access Networks Corporation ("Panix"). It was developed under 9 * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 /* 34 * Copyright (c) 1982, 1986, 1988, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 3. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * @(#)if_ether.c 8.2 (Berkeley) 9/26/94 62 */ 63 64 /* 65 * Ethernet address resolution protocol. 66 * TODO: 67 * add "inuse/lock" bit (or ref. count) along with valid bit 68 */ 69 70 #include <sys/cdefs.h> 71 __KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.255 2017/11/17 07:37:12 ozaki-r Exp $"); 72 73 #ifdef _KERNEL_OPT 74 #include "opt_ddb.h" 75 #include "opt_inet.h" 76 #include "opt_net_mpsafe.h" 77 #endif 78 79 #ifdef INET 80 81 #include "arp.h" 82 #include "bridge.h" 83 84 #include <sys/param.h> 85 #include <sys/systm.h> 86 #include <sys/callout.h> 87 #include <sys/kmem.h> 88 #include <sys/mbuf.h> 89 #include <sys/socket.h> 90 #include <sys/time.h> 91 #include <sys/timetc.h> 92 #include <sys/kernel.h> 93 #include <sys/errno.h> 94 #include <sys/ioctl.h> 95 #include <sys/syslog.h> 96 #include <sys/proc.h> 97 #include <sys/protosw.h> 98 #include <sys/domain.h> 99 #include <sys/sysctl.h> 100 #include <sys/socketvar.h> 101 #include <sys/percpu.h> 102 #include <sys/cprng.h> 103 #include <sys/kmem.h> 104 105 #include <net/ethertypes.h> 106 #include <net/if.h> 107 #include <net/if_dl.h> 108 #include <net/if_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 u_int8_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 *, struct mbuf *, 167 const struct in_addr *, const struct sockaddr *, int); 168 static struct llentry *arpcreate(struct ifnet *, struct mbuf *, 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 static void arp_dad_timer(struct ifaddr *); 177 static void arp_dad_start(struct ifaddr *); 178 static void arp_dad_stop(struct ifaddr *); 179 static void arp_dad_duplicated(struct ifaddr *, const char *); 180 181 static void arp_init_llentry(struct ifnet *, struct llentry *); 182 #if NTOKEN > 0 183 static void arp_free_llentry_tokenring(struct llentry *); 184 #endif 185 186 struct ifqueue arpintrq = { 187 .ifq_head = NULL, 188 .ifq_tail = NULL, 189 .ifq_len = 0, 190 .ifq_maxlen = 50, 191 .ifq_drops = 0, 192 }; 193 static int arp_maxtries = 5; 194 static int useloopback = 1; /* use loopback interface for local traffic */ 195 196 static percpu_t *arpstat_percpu; 197 198 #define ARP_STAT_GETREF() _NET_STAT_GETREF(arpstat_percpu) 199 #define ARP_STAT_PUTREF() _NET_STAT_PUTREF(arpstat_percpu) 200 201 #define ARP_STATINC(x) _NET_STATINC(arpstat_percpu, x) 202 #define ARP_STATADD(x, v) _NET_STATADD(arpstat_percpu, x, v) 203 204 /* revarp state */ 205 static struct in_addr myip, srv_ip; 206 static int myip_initialized = 0; 207 static int revarp_in_progress = 0; 208 static struct ifnet *myip_ifp = NULL; 209 210 static int arp_drainwanted; 211 212 static int log_movements = 1; 213 static int log_permanent_modify = 1; 214 static int log_wrong_iface = 1; 215 static int log_unknown_network = 1; 216 217 /* 218 * this should be elsewhere. 219 */ 220 221 #define LLA_ADDRSTRLEN (16 * 3) 222 223 static char * 224 lla_snprintf(char *, u_int8_t *, int); 225 226 static char * 227 lla_snprintf(char *dst, u_int8_t *adrp, int len) 228 { 229 int i; 230 char *p; 231 232 p = dst; 233 234 *p++ = hexdigits[(*adrp) >> 4]; 235 *p++ = hexdigits[(*adrp++) & 0xf]; 236 237 for (i = 1; i < len && i < 16; i++) { 238 *p++ = ':'; 239 *p++ = hexdigits[(*adrp) >> 4]; 240 *p++ = hexdigits[(*adrp++) & 0xf]; 241 } 242 243 *p = 0; 244 return dst; 245 } 246 247 DOMAIN_DEFINE(arpdomain); /* forward declare and add to link set */ 248 249 static void 250 arp_fasttimo(void) 251 { 252 if (arp_drainwanted) { 253 arp_drain(); 254 arp_drainwanted = 0; 255 } 256 } 257 258 const struct protosw arpsw[] = { 259 { .pr_type = 0, 260 .pr_domain = &arpdomain, 261 .pr_protocol = 0, 262 .pr_flags = 0, 263 .pr_input = 0, 264 .pr_ctlinput = 0, 265 .pr_ctloutput = 0, 266 .pr_usrreqs = 0, 267 .pr_init = arp_init, 268 .pr_fasttimo = arp_fasttimo, 269 .pr_slowtimo = 0, 270 .pr_drain = arp_drainstub, 271 } 272 }; 273 274 struct domain arpdomain = { 275 .dom_family = PF_ARP, 276 .dom_name = "arp", 277 .dom_protosw = arpsw, 278 .dom_protoswNPROTOSW = &arpsw[__arraycount(arpsw)], 279 }; 280 281 static void sysctl_net_inet_arp_setup(struct sysctllog **); 282 283 void 284 arp_init(void) 285 { 286 287 sysctl_net_inet_arp_setup(NULL); 288 arpstat_percpu = percpu_alloc(sizeof(uint64_t) * ARP_NSTATS); 289 IFQ_LOCK_INIT(&arpintrq); 290 } 291 292 static void 293 arp_drainstub(void) 294 { 295 arp_drainwanted = 1; 296 } 297 298 /* 299 * ARP protocol drain routine. Called when memory is in short supply. 300 * Called at splvm(); don't acquire softnet_lock as can be called from 301 * hardware interrupt handlers. 302 */ 303 void 304 arp_drain(void) 305 { 306 307 lltable_drain(AF_INET); 308 } 309 310 static void 311 arptimer(void *arg) 312 { 313 struct llentry *lle = arg; 314 struct ifnet *ifp; 315 316 if (lle == NULL) 317 return; 318 319 if (lle->la_flags & LLE_STATIC) 320 return; 321 322 LLE_WLOCK(lle); 323 if (callout_pending(&lle->la_timer)) { 324 /* 325 * Here we are a bit odd here in the treatment of 326 * active/pending. If the pending bit is set, it got 327 * rescheduled before I ran. The active 328 * bit we ignore, since if it was stopped 329 * in ll_tablefree() and was currently running 330 * it would have return 0 so the code would 331 * not have deleted it since the callout could 332 * not be stopped so we want to go through 333 * with the delete here now. If the callout 334 * was restarted, the pending bit will be back on and 335 * we just want to bail since the callout_reset would 336 * return 1 and our reference would have been removed 337 * by arpresolve() below. 338 */ 339 LLE_WUNLOCK(lle); 340 return; 341 } 342 ifp = lle->lle_tbl->llt_ifp; 343 344 callout_stop(&lle->la_timer); 345 346 /* XXX: LOR avoidance. We still have ref on lle. */ 347 LLE_WUNLOCK(lle); 348 349 IF_AFDATA_LOCK(ifp); 350 LLE_WLOCK(lle); 351 352 /* Guard against race with other llentry_free(). */ 353 if (lle->la_flags & LLE_LINKED) { 354 size_t pkts_dropped; 355 356 LLE_REMREF(lle); 357 pkts_dropped = llentry_free(lle); 358 ARP_STATADD(ARP_STAT_DFRDROPPED, pkts_dropped); 359 ARP_STATADD(ARP_STAT_DFRTOTAL, pkts_dropped); 360 } else { 361 LLE_FREE_LOCKED(lle); 362 } 363 364 IF_AFDATA_UNLOCK(ifp); 365 } 366 367 static void 368 arp_settimer(struct llentry *la, int sec) 369 { 370 371 LLE_WLOCK_ASSERT(la); 372 LLE_ADDREF(la); 373 callout_reset(&la->la_timer, hz * sec, arptimer, la); 374 } 375 376 /* 377 * We set the gateway for RTF_CLONING routes to a "prototype" 378 * link-layer sockaddr whose interface type (if_type) and interface 379 * index (if_index) fields are prepared. 380 */ 381 static struct sockaddr * 382 arp_setgate(struct rtentry *rt, struct sockaddr *gate, 383 const struct sockaddr *netmask) 384 { 385 const struct ifnet *ifp = rt->rt_ifp; 386 uint8_t namelen = strlen(ifp->if_xname); 387 uint8_t addrlen = ifp->if_addrlen; 388 389 /* 390 * XXX: If this is a manually added route to interface 391 * such as older version of routed or gated might provide, 392 * restore cloning bit. 393 */ 394 if ((rt->rt_flags & RTF_HOST) == 0 && netmask != NULL && 395 satocsin(netmask)->sin_addr.s_addr != 0xffffffff) 396 rt->rt_flags |= RTF_CONNECTED; 397 398 if ((rt->rt_flags & (RTF_CONNECTED | RTF_LOCAL))) { 399 union { 400 struct sockaddr sa; 401 struct sockaddr_storage ss; 402 struct sockaddr_dl sdl; 403 } u; 404 /* 405 * Case 1: This route should come from a route to iface. 406 */ 407 sockaddr_dl_init(&u.sdl, sizeof(u.ss), 408 ifp->if_index, ifp->if_type, NULL, namelen, NULL, addrlen); 409 rt_setgate(rt, &u.sa); 410 gate = rt->rt_gateway; 411 } 412 return gate; 413 } 414 415 static void 416 arp_init_llentry(struct ifnet *ifp, struct llentry *lle) 417 { 418 419 switch (ifp->if_type) { 420 #if NTOKEN > 0 421 case IFT_ISO88025: 422 lle->la_opaque = kmem_intr_alloc(sizeof(struct token_rif), 423 KM_NOSLEEP); 424 lle->lle_ll_free = arp_free_llentry_tokenring; 425 break; 426 #endif 427 } 428 } 429 430 #if NTOKEN > 0 431 static void 432 arp_free_llentry_tokenring(struct llentry *lle) 433 { 434 435 kmem_intr_free(lle->la_opaque, sizeof(struct token_rif)); 436 } 437 #endif 438 439 /* 440 * Parallel to llc_rtrequest. 441 */ 442 void 443 arp_rtrequest(int req, struct rtentry *rt, const struct rt_addrinfo *info) 444 { 445 struct sockaddr *gate = rt->rt_gateway; 446 struct in_ifaddr *ia; 447 struct ifaddr *ifa; 448 struct ifnet *ifp = rt->rt_ifp; 449 int bound; 450 int s; 451 452 if (req == RTM_LLINFO_UPD) { 453 if ((ifa = info->rti_ifa) != NULL) 454 arpannounce1(ifa); 455 return; 456 } 457 458 if ((rt->rt_flags & RTF_GATEWAY) != 0) { 459 if (req != RTM_ADD) 460 return; 461 462 /* 463 * linklayers with particular link MTU limitation. 464 */ 465 switch(ifp->if_type) { 466 #if NFDDI > 0 467 case IFT_FDDI: 468 if (ifp->if_mtu > FDDIIPMTU) 469 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 470 break; 471 #endif 472 #if NARCNET > 0 473 case IFT_ARCNET: 474 { 475 int arcipifmtu; 476 477 if (ifp->if_flags & IFF_LINK0) 478 arcipifmtu = arc_ipmtu; 479 else 480 arcipifmtu = ARCMTU; 481 if (ifp->if_mtu > arcipifmtu) 482 rt->rt_rmx.rmx_mtu = arcipifmtu; 483 break; 484 } 485 #endif 486 } 487 return; 488 } 489 490 switch (req) { 491 case RTM_SETGATE: 492 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 493 break; 494 case RTM_ADD: 495 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 496 if (gate == NULL) { 497 log(LOG_ERR, "%s: arp_setgate failed\n", __func__); 498 break; 499 } 500 if ((rt->rt_flags & RTF_CONNECTED) || 501 (rt->rt_flags & RTF_LOCAL)) { 502 /* 503 * Give this route an expiration time, even though 504 * it's a "permanent" route, so that routes cloned 505 * from it do not need their expiration time set. 506 */ 507 KASSERT(time_uptime != 0); 508 rt->rt_expire = time_uptime; 509 /* 510 * linklayers with particular link MTU limitation. 511 */ 512 switch (ifp->if_type) { 513 #if NFDDI > 0 514 case IFT_FDDI: 515 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 516 (rt->rt_rmx.rmx_mtu > FDDIIPMTU || 517 (rt->rt_rmx.rmx_mtu == 0 && 518 ifp->if_mtu > FDDIIPMTU))) 519 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 520 break; 521 #endif 522 #if NARCNET > 0 523 case IFT_ARCNET: 524 { 525 int arcipifmtu; 526 if (ifp->if_flags & IFF_LINK0) 527 arcipifmtu = arc_ipmtu; 528 else 529 arcipifmtu = ARCMTU; 530 531 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 532 (rt->rt_rmx.rmx_mtu > arcipifmtu || 533 (rt->rt_rmx.rmx_mtu == 0 && 534 ifp->if_mtu > arcipifmtu))) 535 rt->rt_rmx.rmx_mtu = arcipifmtu; 536 break; 537 } 538 #endif 539 } 540 if (rt->rt_flags & RTF_CONNECTED) 541 break; 542 } 543 544 bound = curlwp_bind(); 545 /* Announce a new entry if requested. */ 546 if (rt->rt_flags & RTF_ANNOUNCE) { 547 struct psref psref; 548 ia = in_get_ia_on_iface_psref( 549 satocsin(rt_getkey(rt))->sin_addr, ifp, &psref); 550 if (ia != NULL) { 551 arpannounce(ifp, &ia->ia_ifa, 552 CLLADDR(satocsdl(gate))); 553 ia4_release(ia, &psref); 554 } 555 } 556 557 if (gate->sa_family != AF_LINK || 558 gate->sa_len < sockaddr_dl_measure(0, ifp->if_addrlen)) { 559 log(LOG_DEBUG, "%s: bad gateway value\n", __func__); 560 goto out; 561 } 562 563 satosdl(gate)->sdl_type = ifp->if_type; 564 satosdl(gate)->sdl_index = ifp->if_index; 565 566 /* If the route is for a broadcast address mark it as such. 567 * This way we can avoid an expensive call to in_broadcast() 568 * in ip_output() most of the time (because the route passed 569 * to ip_output() is almost always a host route). */ 570 if (rt->rt_flags & RTF_HOST && 571 !(rt->rt_flags & RTF_BROADCAST) && 572 in_broadcast(satocsin(rt_getkey(rt))->sin_addr, rt->rt_ifp)) 573 rt->rt_flags |= RTF_BROADCAST; 574 /* There is little point in resolving the broadcast address */ 575 if (rt->rt_flags & RTF_BROADCAST) 576 goto out; 577 578 /* 579 * When called from rt_ifa_addlocal, we cannot depend on that 580 * the address (rt_getkey(rt)) exits in the address list of the 581 * interface. So check RTF_LOCAL instead. 582 */ 583 if (rt->rt_flags & RTF_LOCAL) { 584 rt->rt_expire = 0; 585 if (useloopback) { 586 rt->rt_ifp = lo0ifp; 587 rt->rt_rmx.rmx_mtu = 0; 588 } 589 goto out; 590 } 591 592 s = pserialize_read_enter(); 593 ia = in_get_ia_on_iface(satocsin(rt_getkey(rt))->sin_addr, ifp); 594 if (ia == NULL) { 595 pserialize_read_exit(s); 596 goto out; 597 } 598 599 rt->rt_expire = 0; 600 if (useloopback) { 601 rt->rt_ifp = lo0ifp; 602 rt->rt_rmx.rmx_mtu = 0; 603 } 604 rt->rt_flags |= RTF_LOCAL; 605 /* 606 * make sure to set rt->rt_ifa to the interface 607 * address we are using, otherwise we will have trouble 608 * with source address selection. 609 */ 610 ifa = &ia->ia_ifa; 611 if (ifa != rt->rt_ifa) 612 /* Assume it doesn't sleep */ 613 rt_replace_ifa(rt, ifa); 614 pserialize_read_exit(s); 615 out: 616 curlwp_bindx(bound); 617 break; 618 } 619 } 620 621 /* 622 * Broadcast an ARP request. Caller specifies: 623 * - arp header source ip address 624 * - arp header target ip address 625 * - arp header source ethernet address 626 */ 627 static void 628 arprequest(struct ifnet *ifp, 629 const struct in_addr *sip, const struct in_addr *tip, 630 const u_int8_t *enaddr) 631 { 632 struct mbuf *m; 633 struct arphdr *ah; 634 struct sockaddr sa; 635 uint64_t *arps; 636 637 KASSERT(sip != NULL); 638 KASSERT(tip != NULL); 639 KASSERT(enaddr != NULL); 640 641 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 642 return; 643 MCLAIM(m, &arpdomain.dom_mowner); 644 switch (ifp->if_type) { 645 case IFT_IEEE1394: 646 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 647 ifp->if_addrlen; 648 break; 649 default: 650 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 651 2 * ifp->if_addrlen; 652 break; 653 } 654 m->m_pkthdr.len = m->m_len; 655 MH_ALIGN(m, m->m_len); 656 ah = mtod(m, struct arphdr *); 657 memset(ah, 0, m->m_len); 658 switch (ifp->if_type) { 659 case IFT_IEEE1394: /* RFC2734 */ 660 /* fill it now for ar_tpa computation */ 661 ah->ar_hrd = htons(ARPHRD_IEEE1394); 662 break; 663 default: 664 /* ifp->if_output will fill ar_hrd */ 665 break; 666 } 667 ah->ar_pro = htons(ETHERTYPE_IP); 668 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 669 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 670 ah->ar_op = htons(ARPOP_REQUEST); 671 memcpy(ar_sha(ah), enaddr, ah->ar_hln); 672 memcpy(ar_spa(ah), sip, ah->ar_pln); 673 memcpy(ar_tpa(ah), tip, ah->ar_pln); 674 sa.sa_family = AF_ARP; 675 sa.sa_len = 2; 676 m->m_flags |= M_BCAST; 677 arps = ARP_STAT_GETREF(); 678 arps[ARP_STAT_SNDTOTAL]++; 679 arps[ARP_STAT_SENDREQUEST]++; 680 ARP_STAT_PUTREF(); 681 if_output_lock(ifp, ifp, m, &sa, NULL); 682 } 683 684 void 685 arpannounce(struct ifnet *ifp, struct ifaddr *ifa, const uint8_t *enaddr) 686 { 687 struct in_ifaddr *ia = ifatoia(ifa); 688 struct in_addr *ip = &IA_SIN(ifa)->sin_addr; 689 690 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) { 691 ARPLOG(LOG_DEBUG, "%s not ready\n", ARPLOGADDR(ip)); 692 return; 693 } 694 arprequest(ifp, ip, ip, enaddr); 695 } 696 697 static void 698 arpannounce1(struct ifaddr *ifa) 699 { 700 701 arpannounce(ifa->ifa_ifp, ifa, CLLADDR(ifa->ifa_ifp->if_sadl)); 702 } 703 704 /* 705 * Resolve an IP address into an ethernet address. If success, 706 * desten is filled in. If there is no entry in arptab, 707 * set one up and broadcast a request for the IP address. 708 * Hold onto this mbuf and resend it once the address 709 * is finally resolved. A return value of 0 indicates 710 * that desten has been filled in and the packet should be sent 711 * normally; a return value of EWOULDBLOCK indicates that the packet has been 712 * held pending resolution. 713 * Any other value indicates an error. 714 */ 715 int 716 arpresolve(struct ifnet *ifp, const struct rtentry *rt, struct mbuf *m, 717 const struct sockaddr *dst, void *desten, size_t destlen) 718 { 719 struct llentry *la; 720 const char *create_lookup; 721 bool renew; 722 int error; 723 struct ifnet *origifp = ifp; 724 #if NCARP > 0 725 if (rt != NULL && rt->rt_ifp->if_type == IFT_CARP) 726 ifp = rt->rt_ifp; 727 #endif 728 729 KASSERT(m != NULL); 730 731 la = arplookup(ifp, m, NULL, dst, 0); 732 if (la == NULL) 733 goto notfound; 734 735 if ((la->la_flags & LLE_VALID) && 736 ((la->la_flags & LLE_STATIC) || la->la_expire > time_uptime)) { 737 KASSERT(destlen >= ifp->if_addrlen); 738 memcpy(desten, &la->ll_addr, ifp->if_addrlen); 739 LLE_RUNLOCK(la); 740 return 0; 741 } 742 743 notfound: 744 #ifdef IFF_STATICARP /* FreeBSD */ 745 #define _IFF_NOARP (IFF_NOARP | IFF_STATICARP) 746 #else 747 #define _IFF_NOARP IFF_NOARP 748 #endif 749 if (ifp->if_flags & _IFF_NOARP) { 750 if (la != NULL) 751 LLE_RUNLOCK(la); 752 error = ENOTSUP; 753 goto bad; 754 } 755 #undef _IFF_NOARP 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 u_int8_t *enaddr = 814 CLLADDR(ifp->if_sadl); 815 arprequest(origifp, 816 &satocsin(rt->rt_ifa->ifa_addr)->sin_addr, 817 &satocsin(dst)->sin_addr, enaddr); 818 } 819 820 return 0; 821 } 822 823 if (la->la_flags & LLE_STATIC) { /* should not happen! */ 824 LLE_RUNLOCK(la); 825 log(LOG_DEBUG, "%s: ouch, empty static llinfo for %s\n", 826 __func__, inet_ntoa(satocsin(dst)->sin_addr)); 827 error = EINVAL; 828 goto bad; 829 } 830 831 renew = (la->la_asked == 0 || la->la_expire != time_uptime); 832 833 /* 834 * There is an arptab entry, but no ethernet address 835 * response yet. Add the mbuf to the list, dropping 836 * the oldest packet if we have exceeded the system 837 * setting. 838 */ 839 LLE_WLOCK_ASSERT(la); 840 if (la->la_numheld >= arp_maxhold) { 841 if (la->la_hold != NULL) { 842 struct mbuf *next = la->la_hold->m_nextpkt; 843 m_freem(la->la_hold); 844 la->la_hold = next; 845 la->la_numheld--; 846 ARP_STATINC(ARP_STAT_DFRDROPPED); 847 ARP_STATINC(ARP_STAT_DFRTOTAL); 848 } 849 } 850 if (la->la_hold != NULL) { 851 struct mbuf *curr = la->la_hold; 852 while (curr->m_nextpkt != NULL) 853 curr = curr->m_nextpkt; 854 curr->m_nextpkt = m; 855 } else 856 la->la_hold = m; 857 la->la_numheld++; 858 if (!renew) 859 LLE_DOWNGRADE(la); 860 861 /* 862 * Return EWOULDBLOCK if we have tried less than arp_maxtries. It 863 * will be masked by ether_output(). Return EHOSTDOWN/EHOSTUNREACH 864 * if we have already sent arp_maxtries ARP requests. Retransmit the 865 * ARP request, but not faster than one request per second. 866 */ 867 if (la->la_asked < arp_maxtries) 868 error = EWOULDBLOCK; /* First request. */ 869 else 870 error = (rt != NULL && rt->rt_flags & RTF_GATEWAY) ? 871 EHOSTUNREACH : EHOSTDOWN; 872 873 if (renew) { 874 const u_int8_t *enaddr = 875 CLLADDR(ifp->if_sadl); 876 la->la_expire = time_uptime; 877 arp_settimer(la, arpt_down); 878 la->la_asked++; 879 LLE_WUNLOCK(la); 880 881 if (rt != NULL) { 882 arprequest(origifp, 883 &satocsin(rt->rt_ifa->ifa_addr)->sin_addr, 884 &satocsin(dst)->sin_addr, enaddr); 885 } else { 886 struct sockaddr_in sin; 887 struct rtentry *_rt; 888 889 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 890 891 /* XXX */ 892 _rt = rtalloc1((struct sockaddr *)&sin, 0); 893 if (_rt == NULL) 894 goto bad; 895 arprequest(origifp, 896 &satocsin(_rt->rt_ifa->ifa_addr)->sin_addr, 897 &satocsin(dst)->sin_addr, enaddr); 898 rt_unref(_rt); 899 } 900 return error; 901 } 902 903 LLE_RUNLOCK(la); 904 return error; 905 906 bad: 907 m_freem(m); 908 return error; 909 } 910 911 /* 912 * Common length and type checks are done here, 913 * then the protocol-specific routine is called. 914 */ 915 void 916 arpintr(void) 917 { 918 struct mbuf *m; 919 struct arphdr *ar; 920 int s; 921 int arplen; 922 923 SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE(); 924 for (;;) { 925 struct ifnet *rcvif; 926 927 IFQ_LOCK(&arpintrq); 928 IF_DEQUEUE(&arpintrq, m); 929 IFQ_UNLOCK(&arpintrq); 930 if (m == NULL) 931 goto out; 932 if ((m->m_flags & M_PKTHDR) == 0) 933 panic("arpintr"); 934 935 MCLAIM(m, &arpdomain.dom_mowner); 936 ARP_STATINC(ARP_STAT_RCVTOTAL); 937 938 /* 939 * First, make sure we have at least struct arphdr. 940 */ 941 if (m->m_len < sizeof(struct arphdr) || 942 (ar = mtod(m, struct arphdr *)) == NULL) 943 goto badlen; 944 945 rcvif = m_get_rcvif(m, &s); 946 if (__predict_false(rcvif == NULL)) { 947 ARP_STATINC(ARP_STAT_RCVNOINT); 948 goto free; 949 } 950 switch (rcvif->if_type) { 951 case IFT_IEEE1394: 952 arplen = sizeof(struct arphdr) + 953 ar->ar_hln + 2 * ar->ar_pln; 954 break; 955 default: 956 arplen = sizeof(struct arphdr) + 957 2 * ar->ar_hln + 2 * ar->ar_pln; 958 break; 959 } 960 m_put_rcvif(rcvif, &s); 961 962 if (/* XXX ntohs(ar->ar_hrd) == ARPHRD_ETHER && */ 963 m->m_len >= arplen) 964 switch (ntohs(ar->ar_pro)) { 965 case ETHERTYPE_IP: 966 case ETHERTYPE_IPTRAILERS: 967 in_arpinput(m); 968 continue; 969 default: 970 ARP_STATINC(ARP_STAT_RCVBADPROTO); 971 } 972 else { 973 badlen: 974 ARP_STATINC(ARP_STAT_RCVBADLEN); 975 } 976 free: 977 m_freem(m); 978 } 979 out: 980 SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 981 return; /* XXX gcc */ 982 } 983 984 /* 985 * ARP for Internet protocols on 10 Mb/s Ethernet. Algorithm is that given in 986 * RFC 826. In addition, a sanity check is performed on the sender protocol 987 * address, to catch impersonators. 988 * 989 * We no longer handle negotiations for use of trailer protocol: formerly, ARP 990 * replied for protocol type ETHERTYPE_TRAIL sent along with IP replies if we 991 * wanted trailers sent to us, and also sent them in response to IP replies. 992 * This allowed either end to announce the desire to receive trailer packets. 993 * 994 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, but 995 * formerly didn't normally send requests. 996 */ 997 static void 998 in_arpinput(struct mbuf *m) 999 { 1000 struct arphdr *ah; 1001 struct ifnet *ifp, *rcvif = NULL; 1002 struct llentry *la = NULL; 1003 struct in_ifaddr *ia = NULL; 1004 #if NBRIDGE > 0 1005 struct in_ifaddr *bridge_ia = NULL; 1006 #endif 1007 #if NCARP > 0 1008 u_int32_t count = 0, index = 0; 1009 #endif 1010 struct sockaddr sa; 1011 struct in_addr isaddr, itaddr, myaddr; 1012 int op; 1013 void *tha; 1014 uint64_t *arps; 1015 struct psref psref, psref_ia; 1016 int s; 1017 char llabuf[LLA_ADDRSTRLEN]; 1018 char ipbuf[INET_ADDRSTRLEN]; 1019 bool do_dad; 1020 1021 if (__predict_false(m_makewritable(&m, 0, m->m_pkthdr.len, M_DONTWAIT))) 1022 goto out; 1023 ah = mtod(m, struct arphdr *); 1024 op = ntohs(ah->ar_op); 1025 1026 if (ah->ar_pln != sizeof(struct in_addr)) 1027 goto out; 1028 1029 ifp = if_get_bylla(ar_sha(ah), ah->ar_hln, &psref); 1030 if (ifp) { 1031 if_put(ifp, &psref); 1032 ARP_STATINC(ARP_STAT_RCVLOCALSHA); 1033 goto out; /* it's from me, ignore it. */ 1034 } 1035 1036 rcvif = ifp = m_get_rcvif_psref(m, &psref); 1037 if (__predict_false(rcvif == NULL)) 1038 goto drop; 1039 1040 /* 1041 * Fix up ah->ar_hrd if necessary, before using ar_tha() or ar_tpa(). 1042 * XXX check ar_hrd more strictly? 1043 */ 1044 switch (ifp->if_type) { 1045 case IFT_IEEE1394: 1046 if (ntohs(ah->ar_hrd) == ARPHRD_IEEE1394) 1047 ; 1048 else { 1049 /* XXX this is to make sure we compute ar_tha right */ 1050 ah->ar_hrd = htons(ARPHRD_IEEE1394); 1051 } 1052 break; 1053 default: 1054 break; 1055 } 1056 1057 memcpy(&isaddr, ar_spa(ah), sizeof(isaddr)); 1058 memcpy(&itaddr, ar_tpa(ah), sizeof(itaddr)); 1059 1060 if (m->m_flags & (M_BCAST|M_MCAST)) 1061 ARP_STATINC(ARP_STAT_RCVMCAST); 1062 1063 /* 1064 * Search for a matching interface address 1065 * or any address on the interface to use 1066 * as a dummy address in the rest of this function. 1067 * 1068 * If the target IP address is zero then try and find 1069 * the sender address for DAD. 1070 */ 1071 myaddr = in_nullhost(itaddr) ? isaddr : itaddr; 1072 s = pserialize_read_enter(); 1073 IN_ADDRHASH_READER_FOREACH(ia, myaddr.s_addr) { 1074 if (!in_hosteq(ia->ia_addr.sin_addr, myaddr)) 1075 continue; 1076 #if NCARP > 0 1077 if (ia->ia_ifp->if_type == IFT_CARP && 1078 ((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) == 1079 (IFF_UP|IFF_RUNNING))) { 1080 index++; 1081 /* XXX: ar_hln? */ 1082 if (ia->ia_ifp == rcvif && (ah->ar_hln >= 6) && 1083 carp_iamatch(ia, ar_sha(ah), 1084 &count, index)) { 1085 break; 1086 } 1087 } else 1088 #endif 1089 if (ia->ia_ifp == rcvif) 1090 break; 1091 #if NBRIDGE > 0 1092 /* 1093 * If the interface we received the packet on 1094 * is part of a bridge, check to see if we need 1095 * to "bridge" the packet to ourselves at this 1096 * layer. Note we still prefer a perfect match, 1097 * but allow this weaker match if necessary. 1098 */ 1099 if (rcvif->if_bridge != NULL && 1100 rcvif->if_bridge == ia->ia_ifp->if_bridge) 1101 bridge_ia = ia; 1102 #endif /* NBRIDGE > 0 */ 1103 } 1104 1105 #if NBRIDGE > 0 1106 if (ia == NULL && bridge_ia != NULL) { 1107 ia = bridge_ia; 1108 m_put_rcvif_psref(rcvif, &psref); 1109 rcvif = NULL; 1110 /* FIXME */ 1111 ifp = bridge_ia->ia_ifp; 1112 } 1113 #endif 1114 if (ia != NULL) 1115 ia4_acquire(ia, &psref_ia); 1116 pserialize_read_exit(s); 1117 1118 if (ah->ar_hln != ifp->if_addrlen) { 1119 ARP_STATINC(ARP_STAT_RCVBADLEN); 1120 log(LOG_WARNING, 1121 "arp from %s: addr len: new %d, i/f %d (ignored)\n", 1122 IN_PRINT(ipbuf, &isaddr), ah->ar_hln, ifp->if_addrlen); 1123 goto out; 1124 } 1125 1126 /* Only do DaD if we have a matching address. */ 1127 do_dad = (ia != NULL); 1128 1129 if (ia == NULL) { 1130 ia = in_get_ia_on_iface_psref(isaddr, rcvif, &psref_ia); 1131 if (ia == NULL) { 1132 ia = in_get_ia_from_ifp_psref(ifp, &psref_ia); 1133 if (ia == NULL) { 1134 ARP_STATINC(ARP_STAT_RCVNOINT); 1135 goto out; 1136 } 1137 } 1138 } 1139 1140 myaddr = ia->ia_addr.sin_addr; 1141 1142 /* XXX checks for bridge case? */ 1143 if (!memcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 1144 ARP_STATINC(ARP_STAT_RCVBCASTSHA); 1145 log(LOG_ERR, 1146 "%s: arp: link address is broadcast for IP address %s!\n", 1147 ifp->if_xname, IN_PRINT(ipbuf, &isaddr)); 1148 goto out; 1149 } 1150 1151 /* 1152 * If the source IP address is zero, this is an RFC 5227 ARP probe 1153 */ 1154 if (in_nullhost(isaddr)) 1155 ARP_STATINC(ARP_STAT_RCVZEROSPA); 1156 else if (in_hosteq(isaddr, myaddr)) 1157 ARP_STATINC(ARP_STAT_RCVLOCALSPA); 1158 1159 if (in_nullhost(itaddr)) 1160 ARP_STATINC(ARP_STAT_RCVZEROTPA); 1161 1162 /* 1163 * DAD check, RFC 5227. 1164 * Collision on sender address is always a duplicate. 1165 * Collision on target address is only a duplicate IF 1166 * the sender address is the null host (ie a DAD probe) AND 1167 * our address is in the TENTATIVE state. 1168 * DUPLICATED state is also checked so that processing stops here 1169 * and an error can be logged. 1170 */ 1171 if (do_dad && 1172 (in_hosteq(isaddr, myaddr) || 1173 (in_nullhost(isaddr) && in_hosteq(itaddr, myaddr) 1174 && ia->ia4_flags & (IN_IFF_TENTATIVE | IN_IFF_DUPLICATED)))) 1175 { 1176 arp_dad_duplicated((struct ifaddr *)ia, 1177 lla_snprintf(llabuf, ar_sha(ah), ah->ar_hln)); 1178 goto out; 1179 } 1180 1181 /* 1182 * If the target IP address is zero, ignore the packet. 1183 * This prevents the code below from trying to answer 1184 * when we are using IP address zero (booting). 1185 */ 1186 if (in_nullhost(itaddr)) 1187 goto out; 1188 1189 if (in_nullhost(isaddr)) 1190 goto reply; 1191 1192 if (in_hosteq(itaddr, myaddr)) 1193 la = arpcreate(ifp, m, &isaddr, NULL, 1); 1194 else 1195 la = arplookup(ifp, m, &isaddr, NULL, 1); 1196 if (la == NULL) 1197 goto reply; 1198 1199 if ((la->la_flags & LLE_VALID) && 1200 memcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) { 1201 if (la->la_flags & LLE_STATIC) { 1202 ARP_STATINC(ARP_STAT_RCVOVERPERM); 1203 if (!log_permanent_modify) 1204 goto out; 1205 log(LOG_INFO, 1206 "%s tried to overwrite permanent arp info" 1207 " for %s\n", 1208 lla_snprintf(llabuf, ar_sha(ah), ah->ar_hln), 1209 IN_PRINT(ipbuf, &isaddr)); 1210 goto out; 1211 } else if (la->lle_tbl->llt_ifp != ifp) { 1212 /* XXX should not happen? */ 1213 ARP_STATINC(ARP_STAT_RCVOVERINT); 1214 if (!log_wrong_iface) 1215 goto out; 1216 log(LOG_INFO, 1217 "%s on %s tried to overwrite " 1218 "arp info for %s on %s\n", 1219 lla_snprintf(llabuf, ar_sha(ah), ah->ar_hln), 1220 ifp->if_xname, IN_PRINT(ipbuf, &isaddr), 1221 la->lle_tbl->llt_ifp->if_xname); 1222 goto out; 1223 } else { 1224 ARP_STATINC(ARP_STAT_RCVOVER); 1225 if (log_movements) 1226 log(LOG_INFO, "arp info overwritten " 1227 "for %s by %s\n", 1228 IN_PRINT(ipbuf, &isaddr), 1229 lla_snprintf(llabuf, ar_sha(ah), 1230 ah->ar_hln)); 1231 } 1232 } 1233 1234 /* XXX llentry should have addrlen? */ 1235 #if 0 1236 /* 1237 * sanity check for the address length. 1238 * XXX this does not work for protocols with variable address 1239 * length. -is 1240 */ 1241 if (sdl->sdl_alen && sdl->sdl_alen != ah->ar_hln) { 1242 ARP_STATINC(ARP_STAT_RCVLENCHG); 1243 log(LOG_WARNING, 1244 "arp from %s: new addr len %d, was %d\n", 1245 IN_PRINT(ipbuf, &isaddr), ah->ar_hln, sdl->sdl_alen); 1246 } 1247 #endif 1248 1249 #if NTOKEN > 0 1250 /* 1251 * XXX uses m_data and assumes the complete answer including 1252 * XXX token-ring headers is in the same buf 1253 */ 1254 if (ifp->if_type == IFT_ISO88025) { 1255 struct token_header *trh; 1256 1257 trh = (struct token_header *)M_TRHSTART(m); 1258 if (trh->token_shost[0] & TOKEN_RI_PRESENT) { 1259 struct token_rif *rif; 1260 size_t riflen; 1261 1262 rif = TOKEN_RIF(trh); 1263 riflen = (ntohs(rif->tr_rcf) & 1264 TOKEN_RCF_LEN_MASK) >> 8; 1265 1266 if (riflen > 2 && 1267 riflen < sizeof(struct token_rif) && 1268 (riflen & 1) == 0) { 1269 rif->tr_rcf ^= htons(TOKEN_RCF_DIRECTION); 1270 rif->tr_rcf &= htons(~TOKEN_RCF_BROADCAST_MASK); 1271 memcpy(TOKEN_RIF_LLE(la), rif, riflen); 1272 } 1273 } 1274 } 1275 #endif /* NTOKEN > 0 */ 1276 1277 KASSERT(sizeof(la->ll_addr) >= ifp->if_addrlen); 1278 memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen); 1279 la->la_flags |= LLE_VALID; 1280 if ((la->la_flags & LLE_STATIC) == 0) { 1281 la->la_expire = time_uptime + arpt_keep; 1282 arp_settimer(la, arpt_keep); 1283 } 1284 la->la_asked = 0; 1285 /* rt->rt_flags &= ~RTF_REJECT; */ 1286 1287 if (la->la_hold != NULL) { 1288 int n = la->la_numheld; 1289 struct mbuf *m_hold, *m_hold_next; 1290 struct sockaddr_in sin; 1291 1292 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 1293 1294 m_hold = la->la_hold; 1295 la->la_hold = NULL; 1296 la->la_numheld = 0; 1297 /* 1298 * We have to unlock here because if_output would call 1299 * arpresolve 1300 */ 1301 LLE_WUNLOCK(la); 1302 ARP_STATADD(ARP_STAT_DFRSENT, n); 1303 ARP_STATADD(ARP_STAT_DFRTOTAL, n); 1304 for (; m_hold != NULL; m_hold = m_hold_next) { 1305 m_hold_next = m_hold->m_nextpkt; 1306 m_hold->m_nextpkt = NULL; 1307 if_output_lock(ifp, ifp, m_hold, sintosa(&sin), NULL); 1308 } 1309 } else 1310 LLE_WUNLOCK(la); 1311 la = NULL; 1312 1313 reply: 1314 if (la != NULL) { 1315 LLE_WUNLOCK(la); 1316 la = NULL; 1317 } 1318 if (op != ARPOP_REQUEST) { 1319 if (op == ARPOP_REPLY) 1320 ARP_STATINC(ARP_STAT_RCVREPLY); 1321 goto out; 1322 } 1323 ARP_STATINC(ARP_STAT_RCVREQUEST); 1324 if (in_hosteq(itaddr, myaddr)) { 1325 /* If our address is unusable, don't reply */ 1326 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) 1327 goto out; 1328 /* I am the target */ 1329 tha = ar_tha(ah); 1330 if (tha) 1331 memcpy(tha, ar_sha(ah), ah->ar_hln); 1332 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1333 } else { 1334 /* Proxy ARP */ 1335 struct llentry *lle = NULL; 1336 struct sockaddr_in sin; 1337 #if NCARP > 0 1338 if (ifp->if_type == IFT_CARP) { 1339 struct ifnet *_rcvif = m_get_rcvif(m, &s); 1340 int iftype = 0; 1341 if (__predict_true(_rcvif != NULL)) 1342 iftype = _rcvif->if_type; 1343 m_put_rcvif(_rcvif, &s); 1344 if (iftype != IFT_CARP) 1345 goto out; 1346 } 1347 #endif 1348 1349 tha = ar_tha(ah); 1350 1351 sockaddr_in_init(&sin, &itaddr, 0); 1352 1353 IF_AFDATA_RLOCK(ifp); 1354 lle = lla_lookup(LLTABLE(ifp), 0, (struct sockaddr *)&sin); 1355 IF_AFDATA_RUNLOCK(ifp); 1356 1357 if ((lle != NULL) && (lle->la_flags & LLE_PUB)) { 1358 if (tha) 1359 memcpy(tha, ar_sha(ah), ah->ar_hln); 1360 memcpy(ar_sha(ah), &lle->ll_addr, ah->ar_hln); 1361 LLE_RUNLOCK(lle); 1362 } else { 1363 if (lle != NULL) 1364 LLE_RUNLOCK(lle); 1365 goto drop; 1366 } 1367 } 1368 ia4_release(ia, &psref_ia); 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 /* 1377 * ieee1394 arp reply is broadcast 1378 */ 1379 m->m_flags &= ~M_MCAST; 1380 m->m_flags |= M_BCAST; 1381 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + ah->ar_hln; 1382 break; 1383 default: 1384 m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */ 1385 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); 1386 break; 1387 } 1388 m->m_pkthdr.len = m->m_len; 1389 sa.sa_family = AF_ARP; 1390 sa.sa_len = 2; 1391 arps = ARP_STAT_GETREF(); 1392 arps[ARP_STAT_SNDTOTAL]++; 1393 arps[ARP_STAT_SNDREPLY]++; 1394 ARP_STAT_PUTREF(); 1395 if_output_lock(ifp, ifp, m, &sa, NULL); 1396 if (rcvif != NULL) 1397 m_put_rcvif_psref(rcvif, &psref); 1398 return; 1399 1400 out: 1401 if (la != NULL) 1402 LLE_WUNLOCK(la); 1403 drop: 1404 if (ia != NULL) 1405 ia4_release(ia, &psref_ia); 1406 if (rcvif != NULL) 1407 m_put_rcvif_psref(rcvif, &psref); 1408 m_freem(m); 1409 } 1410 1411 /* 1412 * Lookup or a new address in arptab. 1413 */ 1414 static struct llentry * 1415 arplookup(struct ifnet *ifp, struct mbuf *m, const struct in_addr *addr, 1416 const struct sockaddr *sa, int wlock) 1417 { 1418 struct sockaddr_in sin; 1419 struct llentry *la; 1420 int flags = wlock ? LLE_EXCLUSIVE : 0; 1421 1422 1423 if (sa == NULL) { 1424 KASSERT(addr != NULL); 1425 sockaddr_in_init(&sin, addr, 0); 1426 sa = sintocsa(&sin); 1427 } 1428 1429 IF_AFDATA_RLOCK(ifp); 1430 la = lla_lookup(LLTABLE(ifp), flags, sa); 1431 IF_AFDATA_RUNLOCK(ifp); 1432 1433 return la; 1434 } 1435 1436 static struct llentry * 1437 arpcreate(struct ifnet *ifp, struct mbuf *m, const struct in_addr *addr, 1438 const struct sockaddr *sa, int wlock) 1439 { 1440 struct sockaddr_in sin; 1441 struct llentry *la; 1442 int flags = wlock ? LLE_EXCLUSIVE : 0; 1443 1444 if (sa == NULL) { 1445 KASSERT(addr != NULL); 1446 sockaddr_in_init(&sin, addr, 0); 1447 sa = sintocsa(&sin); 1448 } 1449 1450 la = arplookup(ifp, m, addr, sa, wlock); 1451 1452 if (la == NULL) { 1453 struct rtentry *rt; 1454 1455 rt = rtalloc1(sa, 0); 1456 IF_AFDATA_WLOCK(ifp); 1457 la = lla_create(LLTABLE(ifp), flags, sa, rt); 1458 IF_AFDATA_WUNLOCK(ifp); 1459 if (rt != NULL) 1460 rt_unref(rt); 1461 1462 if (la != NULL) 1463 arp_init_llentry(ifp, la); 1464 } 1465 1466 return la; 1467 } 1468 1469 int 1470 arpioctl(u_long cmd, void *data) 1471 { 1472 1473 return EOPNOTSUPP; 1474 } 1475 1476 void 1477 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1478 { 1479 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1480 1481 ifa->ifa_rtrequest = arp_rtrequest; 1482 ifa->ifa_flags |= RTF_CONNECTED; 1483 1484 /* ARP will handle DAD for this address. */ 1485 if (in_nullhost(IA_SIN(ifa)->sin_addr)) { 1486 if (ia->ia_dad_stop != NULL) /* safety */ 1487 ia->ia_dad_stop(ifa); 1488 ia->ia_dad_start = NULL; 1489 ia->ia_dad_stop = NULL; 1490 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1491 } else { 1492 ia->ia_dad_start = arp_dad_start; 1493 ia->ia_dad_stop = arp_dad_stop; 1494 if (ia->ia4_flags & IN_IFF_TRYTENTATIVE && ip_dad_count > 0) 1495 ia->ia4_flags |= IN_IFF_TENTATIVE; 1496 else 1497 arpannounce1(ifa); 1498 } 1499 } 1500 1501 TAILQ_HEAD(dadq_head, dadq); 1502 struct dadq { 1503 TAILQ_ENTRY(dadq) dad_list; 1504 struct ifaddr *dad_ifa; 1505 int dad_count; /* max ARP to send */ 1506 int dad_arp_tcount; /* # of trials to send ARP */ 1507 int dad_arp_ocount; /* ARP sent so far */ 1508 int dad_arp_announce; /* max ARP announcements */ 1509 int dad_arp_acount; /* # of announcements */ 1510 struct callout dad_timer_ch; 1511 }; 1512 1513 static struct dadq_head dadq; 1514 static int dad_init = 0; 1515 static int dad_maxtry = 15; /* max # of *tries* to transmit DAD packet */ 1516 static kmutex_t arp_dad_lock; 1517 1518 static struct dadq * 1519 arp_dad_find(struct ifaddr *ifa) 1520 { 1521 struct dadq *dp; 1522 1523 KASSERT(mutex_owned(&arp_dad_lock)); 1524 1525 TAILQ_FOREACH(dp, &dadq, dad_list) { 1526 if (dp->dad_ifa == ifa) 1527 return dp; 1528 } 1529 return NULL; 1530 } 1531 1532 static void 1533 arp_dad_starttimer(struct dadq *dp, int ticks) 1534 { 1535 1536 callout_reset(&dp->dad_timer_ch, ticks, 1537 (void (*)(void *))arp_dad_timer, (void *)dp->dad_ifa); 1538 } 1539 1540 static void 1541 arp_dad_stoptimer(struct dadq *dp) 1542 { 1543 1544 #ifdef NET_MPSAFE 1545 callout_halt(&dp->dad_timer_ch, NULL); 1546 #else 1547 callout_halt(&dp->dad_timer_ch, softnet_lock); 1548 #endif 1549 } 1550 1551 static void 1552 arp_dad_output(struct dadq *dp, struct ifaddr *ifa) 1553 { 1554 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1555 struct ifnet *ifp = ifa->ifa_ifp; 1556 struct in_addr sip; 1557 1558 dp->dad_arp_tcount++; 1559 if ((ifp->if_flags & IFF_UP) == 0) 1560 return; 1561 if ((ifp->if_flags & IFF_RUNNING) == 0) 1562 return; 1563 1564 dp->dad_arp_tcount = 0; 1565 dp->dad_arp_ocount++; 1566 1567 memset(&sip, 0, sizeof(sip)); 1568 arprequest(ifa->ifa_ifp, &sip, &ia->ia_addr.sin_addr, 1569 CLLADDR(ifa->ifa_ifp->if_sadl)); 1570 } 1571 1572 /* 1573 * Start Duplicate Address Detection (DAD) for specified interface address. 1574 */ 1575 static void 1576 arp_dad_start(struct ifaddr *ifa) 1577 { 1578 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1579 struct dadq *dp; 1580 char ipbuf[INET_ADDRSTRLEN]; 1581 1582 if (!dad_init) { 1583 TAILQ_INIT(&dadq); 1584 mutex_init(&arp_dad_lock, MUTEX_DEFAULT, IPL_NONE); 1585 dad_init++; 1586 } 1587 1588 /* 1589 * If we don't need DAD, don't do it. 1590 * - DAD is disabled (ip_dad_count == 0) 1591 */ 1592 if (!(ia->ia4_flags & IN_IFF_TENTATIVE)) { 1593 log(LOG_DEBUG, 1594 "%s: called with non-tentative address %s(%s)\n", __func__, 1595 IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1596 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1597 return; 1598 } 1599 if (!ip_dad_count) { 1600 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1601 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1602 arpannounce1(ifa); 1603 return; 1604 } 1605 KASSERT(ifa->ifa_ifp != NULL); 1606 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) 1607 return; 1608 1609 dp = kmem_intr_alloc(sizeof(*dp), KM_NOSLEEP); 1610 1611 mutex_enter(&arp_dad_lock); 1612 if (arp_dad_find(ifa) != NULL) { 1613 mutex_exit(&arp_dad_lock); 1614 /* DAD already in progress */ 1615 if (dp != NULL) 1616 kmem_intr_free(dp, sizeof(*dp)); 1617 return; 1618 } 1619 1620 if (dp == NULL) { 1621 mutex_exit(&arp_dad_lock); 1622 log(LOG_ERR, "%s: memory allocation failed for %s(%s)\n", 1623 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1624 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1625 return; 1626 } 1627 1628 /* 1629 * Send ARP packet for DAD, ip_dad_count times. 1630 * Note that we must delay the first transmission. 1631 */ 1632 callout_init(&dp->dad_timer_ch, CALLOUT_MPSAFE); 1633 dp->dad_ifa = ifa; 1634 ifaref(ifa); /* just for safety */ 1635 dp->dad_count = ip_dad_count; 1636 dp->dad_arp_announce = 0; /* Will be set when starting to announce */ 1637 dp->dad_arp_acount = dp->dad_arp_ocount = dp->dad_arp_tcount = 0; 1638 TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list); 1639 1640 ARPLOG(LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1641 ARPLOGADDR(&ia->ia_addr.sin_addr)); 1642 1643 arp_dad_starttimer(dp, cprng_fast32() % (PROBE_WAIT * hz)); 1644 1645 mutex_exit(&arp_dad_lock); 1646 } 1647 1648 /* 1649 * terminate DAD unconditionally. used for address removals. 1650 */ 1651 static void 1652 arp_dad_stop(struct ifaddr *ifa) 1653 { 1654 struct dadq *dp; 1655 1656 if (!dad_init) 1657 return; 1658 1659 mutex_enter(&arp_dad_lock); 1660 dp = arp_dad_find(ifa); 1661 if (dp == NULL) { 1662 mutex_exit(&arp_dad_lock); 1663 /* DAD wasn't started yet */ 1664 return; 1665 } 1666 1667 /* Prevent the timer from running anymore. */ 1668 TAILQ_REMOVE(&dadq, dp, dad_list); 1669 mutex_exit(&arp_dad_lock); 1670 1671 arp_dad_stoptimer(dp); 1672 1673 kmem_intr_free(dp, sizeof(*dp)); 1674 ifafree(ifa); 1675 } 1676 1677 static void 1678 arp_dad_timer(struct ifaddr *ifa) 1679 { 1680 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1681 struct dadq *dp; 1682 char ipbuf[INET_ADDRSTRLEN]; 1683 bool need_free = false; 1684 1685 SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE(); 1686 mutex_enter(&arp_dad_lock); 1687 1688 /* Sanity check */ 1689 if (ia == NULL) { 1690 log(LOG_ERR, "%s: called with null parameter\n", __func__); 1691 goto done; 1692 } 1693 dp = arp_dad_find(ifa); 1694 if (dp == NULL) { 1695 /* DAD seems to be stopping, so do nothing. */ 1696 goto done; 1697 } 1698 if (ia->ia4_flags & IN_IFF_DUPLICATED) { 1699 log(LOG_ERR, "%s: called with duplicate address %s(%s)\n", 1700 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1701 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1702 goto done; 1703 } 1704 if ((ia->ia4_flags & IN_IFF_TENTATIVE) == 0 && dp->dad_arp_acount == 0) 1705 { 1706 log(LOG_ERR, "%s: called with non-tentative address %s(%s)\n", 1707 __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr), 1708 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1709 goto done; 1710 } 1711 1712 /* timeouted with IFF_{RUNNING,UP} check */ 1713 if (dp->dad_arp_tcount > dad_maxtry) { 1714 ARPLOG(LOG_INFO, "%s: could not run DAD, driver problem?\n", 1715 if_name(ifa->ifa_ifp)); 1716 1717 TAILQ_REMOVE(&dadq, dp, dad_list); 1718 need_free = true; 1719 goto done; 1720 } 1721 1722 /* Need more checks? */ 1723 if (dp->dad_arp_ocount < dp->dad_count) { 1724 int adelay; 1725 1726 /* 1727 * We have more ARP to go. Send ARP packet for DAD. 1728 */ 1729 arp_dad_output(dp, ifa); 1730 if (dp->dad_arp_ocount < dp->dad_count) 1731 adelay = (PROBE_MIN * hz) + 1732 (cprng_fast32() % 1733 ((PROBE_MAX * hz) - (PROBE_MIN * hz))); 1734 else 1735 adelay = ANNOUNCE_WAIT * hz; 1736 arp_dad_starttimer(dp, adelay); 1737 goto done; 1738 } else if (dp->dad_arp_acount == 0) { 1739 /* 1740 * We are done with DAD. 1741 * No duplicate address found. 1742 */ 1743 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1744 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1745 ARPLOG(LOG_DEBUG, 1746 "%s: DAD complete for %s - no duplicates found\n", 1747 if_name(ifa->ifa_ifp), ARPLOGADDR(&ia->ia_addr.sin_addr)); 1748 dp->dad_arp_announce = ANNOUNCE_NUM; 1749 goto announce; 1750 } else if (dp->dad_arp_acount < dp->dad_arp_announce) { 1751 announce: 1752 /* 1753 * Announce the address. 1754 */ 1755 arpannounce1(ifa); 1756 dp->dad_arp_acount++; 1757 if (dp->dad_arp_acount < dp->dad_arp_announce) { 1758 arp_dad_starttimer(dp, ANNOUNCE_INTERVAL * hz); 1759 goto done; 1760 } 1761 ARPLOG(LOG_DEBUG, 1762 "%s: ARP announcement complete for %s\n", 1763 if_name(ifa->ifa_ifp), ARPLOGADDR(&ia->ia_addr.sin_addr)); 1764 } 1765 1766 TAILQ_REMOVE(&dadq, dp, dad_list); 1767 need_free = true; 1768 done: 1769 mutex_exit(&arp_dad_lock); 1770 1771 if (need_free) { 1772 kmem_intr_free(dp, sizeof(*dp)); 1773 ifafree(ifa); 1774 } 1775 1776 SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 1777 } 1778 1779 static void 1780 arp_dad_duplicated(struct ifaddr *ifa, const char *sha) 1781 { 1782 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1783 struct ifnet *ifp = ifa->ifa_ifp; 1784 char ipbuf[INET_ADDRSTRLEN]; 1785 const char *iastr; 1786 1787 iastr = IN_PRINT(ipbuf, &ia->ia_addr.sin_addr); 1788 1789 if (ia->ia4_flags & (IN_IFF_TENTATIVE|IN_IFF_DUPLICATED)) { 1790 log(LOG_ERR, 1791 "%s: DAD duplicate address %s from %s\n", 1792 if_name(ifp), iastr, sha); 1793 } else if (ia->ia_dad_defended == 0 || 1794 ia->ia_dad_defended < time_uptime - DEFEND_INTERVAL) { 1795 ia->ia_dad_defended = time_uptime; 1796 arpannounce1(ifa); 1797 log(LOG_ERR, 1798 "%s: DAD defended address %s from %s\n", 1799 if_name(ifp), iastr, sha); 1800 return; 1801 } else { 1802 /* If DAD is disabled, just report the duplicate. */ 1803 if (ip_dad_count == 0) { 1804 log(LOG_ERR, 1805 "%s: DAD ignoring duplicate address %s from %s\n", 1806 if_name(ifp), iastr, sha); 1807 return; 1808 } 1809 log(LOG_ERR, 1810 "%s: DAD defence failed for %s from %s\n", 1811 if_name(ifp), iastr, sha); 1812 } 1813 1814 arp_dad_stop(ifa); 1815 1816 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1817 if ((ia->ia4_flags & IN_IFF_DUPLICATED) == 0) { 1818 ia->ia4_flags |= IN_IFF_DUPLICATED; 1819 /* Inform the routing socket of the duplicate address */ 1820 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1821 } 1822 } 1823 1824 /* 1825 * Called from 10 Mb/s Ethernet interrupt handlers 1826 * when ether packet type ETHERTYPE_REVARP 1827 * is received. Common length and type checks are done here, 1828 * then the protocol-specific routine is called. 1829 */ 1830 void 1831 revarpinput(struct mbuf *m) 1832 { 1833 struct arphdr *ar; 1834 1835 if (m->m_len < sizeof(struct arphdr)) 1836 goto out; 1837 ar = mtod(m, struct arphdr *); 1838 #if 0 /* XXX I don't think we need this... and it will prevent other LL */ 1839 if (ntohs(ar->ar_hrd) != ARPHRD_ETHER) 1840 goto out; 1841 #endif 1842 if (m->m_len < sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln)) 1843 goto out; 1844 switch (ntohs(ar->ar_pro)) { 1845 case ETHERTYPE_IP: 1846 case ETHERTYPE_IPTRAILERS: 1847 in_revarpinput(m); 1848 return; 1849 1850 default: 1851 break; 1852 } 1853 out: 1854 m_freem(m); 1855 } 1856 1857 /* 1858 * RARP for Internet protocols on 10 Mb/s Ethernet. 1859 * Algorithm is that given in RFC 903. 1860 * We are only using for bootstrap purposes to get an ip address for one of 1861 * our interfaces. Thus we support no user-interface. 1862 * 1863 * Since the contents of the RARP reply are specific to the interface that 1864 * sent the request, this code must ensure that they are properly associated. 1865 * 1866 * Note: also supports ARP via RARP packets, per the RFC. 1867 */ 1868 void 1869 in_revarpinput(struct mbuf *m) 1870 { 1871 struct arphdr *ah; 1872 void *tha; 1873 int op; 1874 struct ifnet *rcvif; 1875 int s; 1876 1877 ah = mtod(m, struct arphdr *); 1878 op = ntohs(ah->ar_op); 1879 1880 rcvif = m_get_rcvif(m, &s); 1881 if (__predict_false(rcvif == NULL)) 1882 goto out; 1883 switch (rcvif->if_type) { 1884 case IFT_IEEE1394: 1885 /* ARP without target hardware address is not supported */ 1886 goto out; 1887 default: 1888 break; 1889 } 1890 1891 switch (op) { 1892 case ARPOP_REQUEST: 1893 case ARPOP_REPLY: /* per RFC */ 1894 m_put_rcvif(rcvif, &s); 1895 in_arpinput(m); 1896 return; 1897 case ARPOP_REVREPLY: 1898 break; 1899 case ARPOP_REVREQUEST: /* handled by rarpd(8) */ 1900 default: 1901 goto out; 1902 } 1903 if (!revarp_in_progress) 1904 goto out; 1905 if (rcvif != myip_ifp) /* !same interface */ 1906 goto out; 1907 if (myip_initialized) 1908 goto wake; 1909 tha = ar_tha(ah); 1910 if (tha == NULL) 1911 goto out; 1912 if (ah->ar_pln != sizeof(struct in_addr)) 1913 goto out; 1914 if (ah->ar_hln != rcvif->if_sadl->sdl_alen) 1915 goto out; 1916 if (memcmp(tha, CLLADDR(rcvif->if_sadl), rcvif->if_sadl->sdl_alen)) 1917 goto out; 1918 memcpy(&srv_ip, ar_spa(ah), sizeof(srv_ip)); 1919 memcpy(&myip, ar_tpa(ah), sizeof(myip)); 1920 myip_initialized = 1; 1921 wake: /* Do wakeup every time in case it was missed. */ 1922 wakeup((void *)&myip); 1923 1924 out: 1925 m_put_rcvif(rcvif, &s); 1926 m_freem(m); 1927 } 1928 1929 /* 1930 * Send a RARP request for the ip address of the specified interface. 1931 * The request should be RFC 903-compliant. 1932 */ 1933 static void 1934 revarprequest(struct ifnet *ifp) 1935 { 1936 struct sockaddr sa; 1937 struct mbuf *m; 1938 struct arphdr *ah; 1939 void *tha; 1940 1941 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 1942 return; 1943 MCLAIM(m, &arpdomain.dom_mowner); 1944 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) + 1945 2*ifp->if_addrlen; 1946 m->m_pkthdr.len = m->m_len; 1947 MH_ALIGN(m, m->m_len); 1948 ah = mtod(m, struct arphdr *); 1949 memset(ah, 0, m->m_len); 1950 ah->ar_pro = htons(ETHERTYPE_IP); 1951 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 1952 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 1953 ah->ar_op = htons(ARPOP_REVREQUEST); 1954 1955 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1956 tha = ar_tha(ah); 1957 if (tha == NULL) { 1958 m_free(m); 1959 return; 1960 } 1961 memcpy(tha, CLLADDR(ifp->if_sadl), ah->ar_hln); 1962 1963 sa.sa_family = AF_ARP; 1964 sa.sa_len = 2; 1965 m->m_flags |= M_BCAST; 1966 1967 if_output_lock(ifp, ifp, m, &sa, NULL); 1968 } 1969 1970 /* 1971 * RARP for the ip address of the specified interface, but also 1972 * save the ip address of the server that sent the answer. 1973 * Timeout if no response is received. 1974 */ 1975 int 1976 revarpwhoarewe(struct ifnet *ifp, struct in_addr *serv_in, 1977 struct in_addr *clnt_in) 1978 { 1979 int result, count = 20; 1980 1981 myip_initialized = 0; 1982 myip_ifp = ifp; 1983 1984 revarp_in_progress = 1; 1985 while (count--) { 1986 revarprequest(ifp); 1987 result = tsleep((void *)&myip, PSOCK, "revarp", hz/2); 1988 if (result != EWOULDBLOCK) 1989 break; 1990 } 1991 revarp_in_progress = 0; 1992 1993 if (!myip_initialized) 1994 return ENETUNREACH; 1995 1996 memcpy(serv_in, &srv_ip, sizeof(*serv_in)); 1997 memcpy(clnt_in, &myip, sizeof(*clnt_in)); 1998 return 0; 1999 } 2000 2001 void 2002 arp_stat_add(int type, uint64_t count) 2003 { 2004 ARP_STATADD(type, count); 2005 } 2006 2007 static int 2008 sysctl_net_inet_arp_stats(SYSCTLFN_ARGS) 2009 { 2010 2011 return NETSTAT_SYSCTL(arpstat_percpu, ARP_NSTATS); 2012 } 2013 2014 static void 2015 sysctl_net_inet_arp_setup(struct sysctllog **clog) 2016 { 2017 const struct sysctlnode *node; 2018 2019 sysctl_createv(clog, 0, NULL, NULL, 2020 CTLFLAG_PERMANENT, 2021 CTLTYPE_NODE, "inet", NULL, 2022 NULL, 0, NULL, 0, 2023 CTL_NET, PF_INET, CTL_EOL); 2024 sysctl_createv(clog, 0, NULL, &node, 2025 CTLFLAG_PERMANENT, 2026 CTLTYPE_NODE, "arp", 2027 SYSCTL_DESCR("Address Resolution Protocol"), 2028 NULL, 0, NULL, 0, 2029 CTL_NET, PF_INET, CTL_CREATE, CTL_EOL); 2030 2031 sysctl_createv(clog, 0, NULL, NULL, 2032 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2033 CTLTYPE_INT, "keep", 2034 SYSCTL_DESCR("Valid ARP entry lifetime in seconds"), 2035 NULL, 0, &arpt_keep, 0, 2036 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2037 2038 sysctl_createv(clog, 0, NULL, NULL, 2039 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2040 CTLTYPE_INT, "down", 2041 SYSCTL_DESCR("Failed ARP entry lifetime in seconds"), 2042 NULL, 0, &arpt_down, 0, 2043 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2044 2045 sysctl_createv(clog, 0, NULL, NULL, 2046 CTLFLAG_PERMANENT, 2047 CTLTYPE_STRUCT, "stats", 2048 SYSCTL_DESCR("ARP statistics"), 2049 sysctl_net_inet_arp_stats, 0, NULL, 0, 2050 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2051 2052 sysctl_createv(clog, 0, NULL, NULL, 2053 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2054 CTLTYPE_INT, "log_movements", 2055 SYSCTL_DESCR("log ARP replies from MACs different than" 2056 " the one in the cache"), 2057 NULL, 0, &log_movements, 0, 2058 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2059 2060 sysctl_createv(clog, 0, NULL, NULL, 2061 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2062 CTLTYPE_INT, "log_permanent_modify", 2063 SYSCTL_DESCR("log ARP replies from MACs different than" 2064 " the one in the permanent arp entry"), 2065 NULL, 0, &log_permanent_modify, 0, 2066 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2067 2068 sysctl_createv(clog, 0, NULL, NULL, 2069 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2070 CTLTYPE_INT, "log_wrong_iface", 2071 SYSCTL_DESCR("log ARP packets arriving on the wrong" 2072 " interface"), 2073 NULL, 0, &log_wrong_iface, 0, 2074 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2075 2076 sysctl_createv(clog, 0, NULL, NULL, 2077 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2078 CTLTYPE_INT, "log_unknown_network", 2079 SYSCTL_DESCR("log ARP packets from non-local network"), 2080 NULL, 0, &log_unknown_network, 0, 2081 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2082 2083 sysctl_createv(clog, 0, NULL, NULL, 2084 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2085 CTLTYPE_INT, "debug", 2086 SYSCTL_DESCR("Enable ARP DAD debug output"), 2087 NULL, 0, &arp_debug, 0, 2088 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2089 } 2090 2091 #endif /* INET */ 2092