1 /* $NetBSD: if_arp.c,v 1.222 2016/08/08 06:28:09 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 1.222 2016/08/08 06:28:09 ozaki-r Exp $"); 72 73 #ifdef _KERNEL_OPT 74 #include "opt_ddb.h" 75 #include "opt_inet.h" 76 #endif 77 78 #ifdef INET 79 80 #include "bridge.h" 81 82 #include <sys/param.h> 83 #include <sys/systm.h> 84 #include <sys/callout.h> 85 #include <sys/malloc.h> 86 #include <sys/mbuf.h> 87 #include <sys/socket.h> 88 #include <sys/time.h> 89 #include <sys/timetc.h> 90 #include <sys/kernel.h> 91 #include <sys/errno.h> 92 #include <sys/ioctl.h> 93 #include <sys/syslog.h> 94 #include <sys/proc.h> 95 #include <sys/protosw.h> 96 #include <sys/domain.h> 97 #include <sys/sysctl.h> 98 #include <sys/socketvar.h> 99 #include <sys/percpu.h> 100 #include <sys/cprng.h> 101 #include <sys/kmem.h> 102 103 #include <net/ethertypes.h> 104 #include <net/if.h> 105 #include <net/if_dl.h> 106 #include <net/if_token.h> 107 #include <net/if_types.h> 108 #include <net/if_ether.h> 109 #include <net/if_llatbl.h> 110 #include <net/net_osdep.h> 111 #include <net/route.h> 112 #include <net/net_stats.h> 113 114 #include <netinet/in.h> 115 #include <netinet/in_systm.h> 116 #include <netinet/in_var.h> 117 #include <netinet/ip.h> 118 #include <netinet/if_inarp.h> 119 120 #include "arcnet.h" 121 #if NARCNET > 0 122 #include <net/if_arc.h> 123 #endif 124 #include "fddi.h" 125 #if NFDDI > 0 126 #include <net/if_fddi.h> 127 #endif 128 #include "token.h" 129 #include "carp.h" 130 #if NCARP > 0 131 #include <netinet/ip_carp.h> 132 #endif 133 134 #define SIN(s) ((struct sockaddr_in *)s) 135 #define SRP(s) ((struct sockaddr_inarp *)s) 136 137 /* 138 * ARP trailer negotiation. Trailer protocol is not IP specific, 139 * but ARP request/response use IP addresses. 140 */ 141 #define ETHERTYPE_IPTRAILERS ETHERTYPE_TRAIL 142 143 /* timer values */ 144 static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */ 145 static int arpt_down = 20; /* once declared down, don't send for 20 secs */ 146 static int arp_maxhold = 1; /* number of packets to hold per ARP entry */ 147 #define rt_expire rt_rmx.rmx_expire 148 #define rt_pksent rt_rmx.rmx_pksent 149 150 int ip_dad_count = PROBE_NUM; 151 #ifdef ARP_DEBUG 152 static int arp_debug = 1; 153 #else 154 static int arp_debug = 0; 155 #endif 156 #define arplog(x) do { if (arp_debug) log x; } while (/*CONSTCOND*/ 0) 157 158 static void arp_init(void); 159 160 static struct sockaddr *arp_setgate(struct rtentry *, struct sockaddr *, 161 const struct sockaddr *); 162 static void arptimer(void *); 163 static void arp_settimer(struct llentry *, int); 164 static struct llentry *arplookup(struct ifnet *, struct mbuf *, 165 const struct in_addr *, const struct sockaddr *, int); 166 static struct llentry *arpcreate(struct ifnet *, struct mbuf *, 167 const struct in_addr *, const struct sockaddr *, int); 168 static void in_arpinput(struct mbuf *); 169 static void in_revarpinput(struct mbuf *); 170 static void revarprequest(struct ifnet *); 171 172 static void arp_drainstub(void); 173 174 static void arp_dad_timer(struct ifaddr *); 175 static void arp_dad_start(struct ifaddr *); 176 static void arp_dad_stop(struct ifaddr *); 177 static void arp_dad_duplicated(struct ifaddr *); 178 179 static void arp_init_llentry(struct ifnet *, struct llentry *); 180 #if NTOKEN > 0 181 static void arp_free_llentry_tokenring(struct llentry *); 182 #endif 183 184 struct ifqueue arpintrq = { 185 .ifq_head = NULL, 186 .ifq_tail = NULL, 187 .ifq_len = 0, 188 .ifq_maxlen = 50, 189 .ifq_drops = 0, 190 }; 191 static int arp_maxtries = 5; 192 static int useloopback = 1; /* use loopback interface for local traffic */ 193 194 static percpu_t *arpstat_percpu; 195 196 #define ARP_STAT_GETREF() _NET_STAT_GETREF(arpstat_percpu) 197 #define ARP_STAT_PUTREF() _NET_STAT_PUTREF(arpstat_percpu) 198 199 #define ARP_STATINC(x) _NET_STATINC(arpstat_percpu, x) 200 #define ARP_STATADD(x, v) _NET_STATADD(arpstat_percpu, x, v) 201 202 /* revarp state */ 203 static struct in_addr myip, srv_ip; 204 static int myip_initialized = 0; 205 static int revarp_in_progress = 0; 206 static struct ifnet *myip_ifp = NULL; 207 208 static int arp_drainwanted; 209 210 static int log_movements = 1; 211 static int log_permanent_modify = 1; 212 static int log_wrong_iface = 1; 213 static int log_unknown_network = 1; 214 215 /* 216 * this should be elsewhere. 217 */ 218 219 static char * 220 lla_snprintf(u_int8_t *, int); 221 222 static char * 223 lla_snprintf(u_int8_t *adrp, int len) 224 { 225 #define NUMBUFS 3 226 static char buf[NUMBUFS][16*3]; 227 static int bnum = 0; 228 229 int i; 230 char *p; 231 232 p = buf[bnum]; 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 p = buf[bnum]; 245 bnum = (bnum + 1) % NUMBUFS; 246 return p; 247 } 248 249 DOMAIN_DEFINE(arpdomain); /* forward declare and add to link set */ 250 251 static void 252 arp_fasttimo(void) 253 { 254 if (arp_drainwanted) { 255 arp_drain(); 256 arp_drainwanted = 0; 257 } 258 } 259 260 const struct protosw arpsw[] = { 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 } 292 293 static void 294 arp_drainstub(void) 295 { 296 arp_drainwanted = 1; 297 } 298 299 /* 300 * ARP protocol drain routine. Called when memory is in short supply. 301 * Called at splvm(); don't acquire softnet_lock as can be called from 302 * hardware interrupt handlers. 303 */ 304 void 305 arp_drain(void) 306 { 307 308 lltable_drain(AF_INET); 309 } 310 311 static void 312 arptimer(void *arg) 313 { 314 struct llentry *lle = arg; 315 struct ifnet *ifp; 316 317 if (lle == NULL) 318 return; 319 320 if (lle->la_flags & LLE_STATIC) 321 return; 322 323 LLE_WLOCK(lle); 324 if (callout_pending(&lle->la_timer)) { 325 /* 326 * Here we are a bit odd here in the treatment of 327 * active/pending. If the pending bit is set, it got 328 * rescheduled before I ran. The active 329 * bit we ignore, since if it was stopped 330 * in ll_tablefree() and was currently running 331 * it would have return 0 so the code would 332 * not have deleted it since the callout could 333 * not be stopped so we want to go through 334 * with the delete here now. If the callout 335 * was restarted, the pending bit will be back on and 336 * we just want to bail since the callout_reset would 337 * return 1 and our reference would have been removed 338 * by arpresolve() below. 339 */ 340 LLE_WUNLOCK(lle); 341 return; 342 } 343 ifp = lle->lle_tbl->llt_ifp; 344 345 callout_stop(&lle->la_timer); 346 347 /* XXX: LOR avoidance. We still have ref on lle. */ 348 LLE_WUNLOCK(lle); 349 350 IF_AFDATA_LOCK(ifp); 351 LLE_WLOCK(lle); 352 353 /* Guard against race with other llentry_free(). */ 354 if (lle->la_flags & LLE_LINKED) { 355 size_t pkts_dropped; 356 357 LLE_REMREF(lle); 358 pkts_dropped = llentry_free(lle); 359 ARP_STATADD(ARP_STAT_DFRDROPPED, pkts_dropped); 360 ARP_STATADD(ARP_STAT_DFRTOTAL, pkts_dropped); 361 } else { 362 LLE_FREE_LOCKED(lle); 363 } 364 365 IF_AFDATA_UNLOCK(ifp); 366 } 367 368 static void 369 arp_settimer(struct llentry *la, int sec) 370 { 371 372 LLE_WLOCK_ASSERT(la); 373 LLE_ADDREF(la); 374 callout_reset(&la->la_timer, hz * sec, arptimer, la); 375 } 376 377 /* 378 * We set the gateway for RTF_CLONING routes to a "prototype" 379 * link-layer sockaddr whose interface type (if_type) and interface 380 * index (if_index) fields are prepared. 381 */ 382 static struct sockaddr * 383 arp_setgate(struct rtentry *rt, struct sockaddr *gate, 384 const struct sockaddr *netmask) 385 { 386 const struct ifnet *ifp = rt->rt_ifp; 387 uint8_t namelen = strlen(ifp->if_xname); 388 uint8_t addrlen = ifp->if_addrlen; 389 390 /* 391 * XXX: If this is a manually added route to interface 392 * such as older version of routed or gated might provide, 393 * restore cloning bit. 394 */ 395 if ((rt->rt_flags & RTF_HOST) == 0 && netmask != NULL && 396 satocsin(netmask)->sin_addr.s_addr != 0xffffffff) 397 rt->rt_flags |= RTF_CONNECTED; 398 399 if ((rt->rt_flags & (RTF_CONNECTED | RTF_LOCAL))) { 400 union { 401 struct sockaddr sa; 402 struct sockaddr_storage ss; 403 struct sockaddr_dl sdl; 404 } u; 405 /* 406 * Case 1: This route should come from a route to iface. 407 */ 408 sockaddr_dl_init(&u.sdl, sizeof(u.ss), 409 ifp->if_index, ifp->if_type, NULL, namelen, NULL, addrlen); 410 rt_setgate(rt, &u.sa); 411 gate = rt->rt_gateway; 412 } 413 return gate; 414 } 415 416 static void 417 arp_init_llentry(struct ifnet *ifp, struct llentry *lle) 418 { 419 420 switch (ifp->if_type) { 421 #if NTOKEN > 0 422 case IFT_ISO88025: 423 lle->la_opaque = kmem_intr_alloc(sizeof(struct token_rif), 424 KM_NOSLEEP); 425 lle->lle_ll_free = arp_free_llentry_tokenring; 426 break; 427 #endif 428 } 429 } 430 431 #if NTOKEN > 0 432 static void 433 arp_free_llentry_tokenring(struct llentry *lle) 434 { 435 436 kmem_intr_free(lle->la_opaque, sizeof(struct token_rif)); 437 } 438 #endif 439 440 /* 441 * Parallel to llc_rtrequest. 442 */ 443 void 444 arp_rtrequest(int req, struct rtentry *rt, const struct rt_addrinfo *info) 445 { 446 struct sockaddr *gate = rt->rt_gateway; 447 struct in_ifaddr *ia; 448 struct ifaddr *ifa; 449 struct ifnet *ifp = rt->rt_ifp; 450 int bound; 451 int s; 452 453 if (req == RTM_LLINFO_UPD) { 454 struct in_addr *in; 455 456 if ((ifa = info->rti_ifa) == NULL) 457 return; 458 459 in = &ifatoia(ifa)->ia_addr.sin_addr; 460 461 if (ifatoia(ifa)->ia4_flags & 462 (IN_IFF_NOTREADY | IN_IFF_DETACHED)) 463 { 464 arplog((LOG_DEBUG, "arp_request: %s not ready\n", 465 in_fmtaddr(*in))); 466 return; 467 } 468 469 arprequest(ifa->ifa_ifp, in, in, 470 CLLADDR(ifa->ifa_ifp->if_sadl)); 471 return; 472 } 473 474 if ((rt->rt_flags & RTF_GATEWAY) != 0) { 475 if (req != RTM_ADD) 476 return; 477 478 /* 479 * linklayers with particular link MTU limitation. 480 */ 481 switch(ifp->if_type) { 482 #if NFDDI > 0 483 case IFT_FDDI: 484 if (ifp->if_mtu > FDDIIPMTU) 485 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 486 break; 487 #endif 488 #if NARCNET > 0 489 case IFT_ARCNET: 490 { 491 int arcipifmtu; 492 493 if (ifp->if_flags & IFF_LINK0) 494 arcipifmtu = arc_ipmtu; 495 else 496 arcipifmtu = ARCMTU; 497 if (ifp->if_mtu > arcipifmtu) 498 rt->rt_rmx.rmx_mtu = arcipifmtu; 499 break; 500 } 501 #endif 502 } 503 return; 504 } 505 506 switch (req) { 507 case RTM_SETGATE: 508 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 509 break; 510 case RTM_ADD: 511 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 512 if (gate == NULL) { 513 log(LOG_ERR, "%s: arp_setgate failed\n", __func__); 514 break; 515 } 516 if ((rt->rt_flags & RTF_CONNECTED) || 517 (rt->rt_flags & RTF_LOCAL)) { 518 /* 519 * Give this route an expiration time, even though 520 * it's a "permanent" route, so that routes cloned 521 * from it do not need their expiration time set. 522 */ 523 KASSERT(time_uptime != 0); 524 rt->rt_expire = time_uptime; 525 /* 526 * linklayers with particular link MTU limitation. 527 */ 528 switch (ifp->if_type) { 529 #if NFDDI > 0 530 case IFT_FDDI: 531 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 532 (rt->rt_rmx.rmx_mtu > FDDIIPMTU || 533 (rt->rt_rmx.rmx_mtu == 0 && 534 ifp->if_mtu > FDDIIPMTU))) 535 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 536 break; 537 #endif 538 #if NARCNET > 0 539 case IFT_ARCNET: 540 { 541 int arcipifmtu; 542 if (ifp->if_flags & IFF_LINK0) 543 arcipifmtu = arc_ipmtu; 544 else 545 arcipifmtu = ARCMTU; 546 547 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 548 (rt->rt_rmx.rmx_mtu > arcipifmtu || 549 (rt->rt_rmx.rmx_mtu == 0 && 550 ifp->if_mtu > arcipifmtu))) 551 rt->rt_rmx.rmx_mtu = arcipifmtu; 552 break; 553 } 554 #endif 555 } 556 if (rt->rt_flags & RTF_CONNECTED) 557 break; 558 } 559 560 bound = curlwp_bind(); 561 /* Announce a new entry if requested. */ 562 if (rt->rt_flags & RTF_ANNOUNCE) { 563 struct psref psref; 564 ia = in_get_ia_on_iface_psref( 565 satocsin(rt_getkey(rt))->sin_addr, ifp, &psref); 566 if (ia == NULL || 567 ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) 568 ; 569 else 570 arprequest(ifp, 571 &satocsin(rt_getkey(rt))->sin_addr, 572 &satocsin(rt_getkey(rt))->sin_addr, 573 CLLADDR(satocsdl(gate))); 574 if (ia != NULL) 575 ia4_release(ia, &psref); 576 } 577 578 if (gate->sa_family != AF_LINK || 579 gate->sa_len < sockaddr_dl_measure(0, ifp->if_addrlen)) { 580 log(LOG_DEBUG, "%s: bad gateway value\n", __func__); 581 goto out; 582 } 583 584 satosdl(gate)->sdl_type = ifp->if_type; 585 satosdl(gate)->sdl_index = ifp->if_index; 586 587 /* If the route is for a broadcast address mark it as such. 588 * This way we can avoid an expensive call to in_broadcast() 589 * in ip_output() most of the time (because the route passed 590 * to ip_output() is almost always a host route). */ 591 if (rt->rt_flags & RTF_HOST && 592 !(rt->rt_flags & RTF_BROADCAST) && 593 in_broadcast(satocsin(rt_getkey(rt))->sin_addr, rt->rt_ifp)) 594 rt->rt_flags |= RTF_BROADCAST; 595 /* There is little point in resolving the broadcast address */ 596 if (rt->rt_flags & RTF_BROADCAST) 597 goto out; 598 599 /* 600 * When called from rt_ifa_addlocal, we cannot depend on that 601 * the address (rt_getkey(rt)) exits in the address list of the 602 * interface. So check RTF_LOCAL instead. 603 */ 604 if (rt->rt_flags & RTF_LOCAL) { 605 rt->rt_expire = 0; 606 if (useloopback) { 607 rt->rt_ifp = lo0ifp; 608 rt->rt_rmx.rmx_mtu = 0; 609 } 610 goto out; 611 } 612 613 s = pserialize_read_enter(); 614 ia = in_get_ia_on_iface(satocsin(rt_getkey(rt))->sin_addr, ifp); 615 if (ia == NULL) { 616 pserialize_read_exit(s); 617 goto out; 618 } 619 620 rt->rt_expire = 0; 621 if (useloopback) { 622 rt->rt_ifp = lo0ifp; 623 rt->rt_rmx.rmx_mtu = 0; 624 } 625 rt->rt_flags |= RTF_LOCAL; 626 /* 627 * make sure to set rt->rt_ifa to the interface 628 * address we are using, otherwise we will have trouble 629 * with source address selection. 630 */ 631 ifa = &ia->ia_ifa; 632 if (ifa != rt->rt_ifa) 633 /* Assume it doesn't sleep */ 634 rt_replace_ifa(rt, ifa); 635 pserialize_read_exit(s); 636 out: 637 curlwp_bindx(bound); 638 break; 639 } 640 } 641 642 /* 643 * Broadcast an ARP request. Caller specifies: 644 * - arp header source ip address 645 * - arp header target ip address 646 * - arp header source ethernet address 647 */ 648 void 649 arprequest(struct ifnet *ifp, 650 const struct in_addr *sip, const struct in_addr *tip, 651 const u_int8_t *enaddr) 652 { 653 struct mbuf *m; 654 struct arphdr *ah; 655 struct sockaddr sa; 656 uint64_t *arps; 657 658 KASSERT(sip != NULL); 659 KASSERT(tip != NULL); 660 KASSERT(enaddr != NULL); 661 662 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 663 return; 664 MCLAIM(m, &arpdomain.dom_mowner); 665 switch (ifp->if_type) { 666 case IFT_IEEE1394: 667 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 668 ifp->if_addrlen; 669 break; 670 default: 671 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 672 2 * ifp->if_addrlen; 673 break; 674 } 675 m->m_pkthdr.len = m->m_len; 676 MH_ALIGN(m, m->m_len); 677 ah = mtod(m, struct arphdr *); 678 memset(ah, 0, m->m_len); 679 switch (ifp->if_type) { 680 case IFT_IEEE1394: /* RFC2734 */ 681 /* fill it now for ar_tpa computation */ 682 ah->ar_hrd = htons(ARPHRD_IEEE1394); 683 break; 684 default: 685 /* ifp->if_output will fill ar_hrd */ 686 break; 687 } 688 ah->ar_pro = htons(ETHERTYPE_IP); 689 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 690 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 691 ah->ar_op = htons(ARPOP_REQUEST); 692 memcpy(ar_sha(ah), enaddr, ah->ar_hln); 693 memcpy(ar_spa(ah), sip, ah->ar_pln); 694 memcpy(ar_tpa(ah), tip, ah->ar_pln); 695 sa.sa_family = AF_ARP; 696 sa.sa_len = 2; 697 m->m_flags |= M_BCAST; 698 arps = ARP_STAT_GETREF(); 699 arps[ARP_STAT_SNDTOTAL]++; 700 arps[ARP_STAT_SENDREQUEST]++; 701 ARP_STAT_PUTREF(); 702 if_output_lock(ifp, ifp, m, &sa, NULL); 703 } 704 705 /* 706 * Resolve an IP address into an ethernet address. If success, 707 * desten is filled in. If there is no entry in arptab, 708 * set one up and broadcast a request for the IP address. 709 * Hold onto this mbuf and resend it once the address 710 * is finally resolved. A return value of 0 indicates 711 * that desten has been filled in and the packet should be sent 712 * normally; a return value of EWOULDBLOCK indicates that the packet has been 713 * held pending resolution. 714 * Any other value indicates an error. 715 */ 716 int 717 arpresolve(struct ifnet *ifp, const struct rtentry *rt, struct mbuf *m, 718 const struct sockaddr *dst, void *desten, size_t destlen) 719 { 720 struct llentry *la; 721 const char *create_lookup; 722 bool renew; 723 int error; 724 725 KASSERT(m != NULL); 726 727 la = arplookup(ifp, m, NULL, dst, 0); 728 if (la == NULL) 729 goto notfound; 730 731 if ((la->la_flags & LLE_VALID) && 732 ((la->la_flags & LLE_STATIC) || la->la_expire > time_uptime)) { 733 KASSERT(destlen >= ifp->if_addrlen); 734 memcpy(desten, &la->ll_addr, ifp->if_addrlen); 735 LLE_RUNLOCK(la); 736 return 0; 737 } 738 739 notfound: 740 #ifdef IFF_STATICARP /* FreeBSD */ 741 #define _IFF_NOARP (IFF_NOARP | IFF_STATICARP) 742 #else 743 #define _IFF_NOARP IFF_NOARP 744 #endif 745 if (ifp->if_flags & _IFF_NOARP) { 746 if (la != NULL) 747 LLE_RUNLOCK(la); 748 error = ENOTSUP; 749 goto bad; 750 } 751 #undef _IFF_NOARP 752 if (la == NULL) { 753 create_lookup = "create"; 754 IF_AFDATA_WLOCK(ifp); 755 la = lla_create(LLTABLE(ifp), LLE_EXCLUSIVE, dst); 756 IF_AFDATA_WUNLOCK(ifp); 757 if (la == NULL) 758 ARP_STATINC(ARP_STAT_ALLOCFAIL); 759 else 760 arp_init_llentry(ifp, la); 761 } else if (LLE_TRY_UPGRADE(la) == 0) { 762 create_lookup = "lookup"; 763 LLE_RUNLOCK(la); 764 IF_AFDATA_RLOCK(ifp); 765 la = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst); 766 IF_AFDATA_RUNLOCK(ifp); 767 } 768 769 error = EINVAL; 770 if (la == NULL) { 771 log(LOG_DEBUG, 772 "%s: failed to %s llentry for %s on %s\n", 773 __func__, create_lookup, inet_ntoa(satocsin(dst)->sin_addr), 774 ifp->if_xname); 775 goto bad; 776 } 777 778 if ((la->la_flags & LLE_VALID) && 779 ((la->la_flags & LLE_STATIC) || la->la_expire > time_uptime)) 780 { 781 KASSERT(destlen >= ifp->if_addrlen); 782 memcpy(desten, &la->ll_addr, ifp->if_addrlen); 783 renew = false; 784 /* 785 * If entry has an expiry time and it is approaching, 786 * see if we need to send an ARP request within this 787 * arpt_down interval. 788 */ 789 if (!(la->la_flags & LLE_STATIC) && 790 time_uptime + la->la_preempt > la->la_expire) 791 { 792 renew = true; 793 la->la_preempt--; 794 } 795 796 LLE_WUNLOCK(la); 797 798 if (renew) { 799 const u_int8_t *enaddr = 800 #if NCARP > 0 801 (ifp->if_type == IFT_CARP) ? 802 CLLADDR(ifp->if_sadl): 803 #endif 804 CLLADDR(ifp->if_sadl); 805 arprequest(ifp, 806 &satocsin(rt->rt_ifa->ifa_addr)->sin_addr, 807 &satocsin(dst)->sin_addr, enaddr); 808 } 809 810 return 0; 811 } 812 813 if (la->la_flags & LLE_STATIC) { /* should not happen! */ 814 LLE_RUNLOCK(la); 815 log(LOG_DEBUG, "%s: ouch, empty static llinfo for %s\n", 816 __func__, inet_ntoa(satocsin(dst)->sin_addr)); 817 error = EINVAL; 818 goto bad; 819 } 820 821 renew = (la->la_asked == 0 || la->la_expire != time_uptime); 822 823 /* 824 * There is an arptab entry, but no ethernet address 825 * response yet. Add the mbuf to the list, dropping 826 * the oldest packet if we have exceeded the system 827 * setting. 828 */ 829 LLE_WLOCK_ASSERT(la); 830 if (la->la_numheld >= arp_maxhold) { 831 if (la->la_hold != NULL) { 832 struct mbuf *next = la->la_hold->m_nextpkt; 833 m_freem(la->la_hold); 834 la->la_hold = next; 835 la->la_numheld--; 836 ARP_STATINC(ARP_STAT_DFRDROPPED); 837 ARP_STATINC(ARP_STAT_DFRTOTAL); 838 } 839 } 840 if (la->la_hold != NULL) { 841 struct mbuf *curr = la->la_hold; 842 while (curr->m_nextpkt != NULL) 843 curr = curr->m_nextpkt; 844 curr->m_nextpkt = m; 845 } else 846 la->la_hold = m; 847 la->la_numheld++; 848 if (!renew) 849 LLE_DOWNGRADE(la); 850 851 /* 852 * Return EWOULDBLOCK if we have tried less than arp_maxtries. It 853 * will be masked by ether_output(). Return EHOSTDOWN/EHOSTUNREACH 854 * if we have already sent arp_maxtries ARP requests. Retransmit the 855 * ARP request, but not faster than one request per second. 856 */ 857 if (la->la_asked < arp_maxtries) 858 error = EWOULDBLOCK; /* First request. */ 859 else 860 error = (rt != NULL && rt->rt_flags & RTF_GATEWAY) ? 861 EHOSTUNREACH : EHOSTDOWN; 862 863 if (renew) { 864 const u_int8_t *enaddr = 865 #if NCARP > 0 866 (rt != NULL && rt->rt_ifp->if_type == IFT_CARP) ? 867 CLLADDR(rt->rt_ifp->if_sadl): 868 #endif 869 CLLADDR(ifp->if_sadl); 870 la->la_expire = time_uptime; 871 arp_settimer(la, arpt_down); 872 la->la_asked++; 873 LLE_WUNLOCK(la); 874 875 if (rt != NULL) { 876 arprequest(ifp, &satocsin(rt->rt_ifa->ifa_addr)->sin_addr, 877 &satocsin(dst)->sin_addr, enaddr); 878 } else { 879 struct sockaddr_in sin; 880 struct rtentry *_rt; 881 882 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 883 884 /* XXX */ 885 _rt = rtalloc1((struct sockaddr *)&sin, 0); 886 if (_rt == NULL) 887 goto bad; 888 arprequest(ifp, 889 &satocsin(_rt->rt_ifa->ifa_addr)->sin_addr, 890 &satocsin(dst)->sin_addr, enaddr); 891 rtfree(_rt); 892 } 893 return error; 894 } 895 896 LLE_RUNLOCK(la); 897 return error; 898 899 bad: 900 m_freem(m); 901 return error; 902 } 903 904 /* 905 * Common length and type checks are done here, 906 * then the protocol-specific routine is called. 907 */ 908 void 909 arpintr(void) 910 { 911 struct mbuf *m; 912 struct arphdr *ar; 913 int s; 914 int arplen; 915 916 mutex_enter(softnet_lock); 917 KERNEL_LOCK(1, NULL); 918 while (arpintrq.ifq_head) { 919 struct ifnet *rcvif; 920 921 s = splnet(); 922 IF_DEQUEUE(&arpintrq, m); 923 splx(s); 924 if (m == NULL || (m->m_flags & M_PKTHDR) == 0) 925 panic("arpintr"); 926 927 MCLAIM(m, &arpdomain.dom_mowner); 928 ARP_STATINC(ARP_STAT_RCVTOTAL); 929 930 /* 931 * First, make sure we have at least struct arphdr. 932 */ 933 if (m->m_len < sizeof(struct arphdr) || 934 (ar = mtod(m, struct arphdr *)) == NULL) 935 goto badlen; 936 937 rcvif = m_get_rcvif(m, &s); 938 switch (rcvif->if_type) { 939 case IFT_IEEE1394: 940 arplen = sizeof(struct arphdr) + 941 ar->ar_hln + 2 * ar->ar_pln; 942 break; 943 default: 944 arplen = sizeof(struct arphdr) + 945 2 * ar->ar_hln + 2 * ar->ar_pln; 946 break; 947 } 948 m_put_rcvif(rcvif, &s); 949 950 if (/* XXX ntohs(ar->ar_hrd) == ARPHRD_ETHER && */ 951 m->m_len >= arplen) 952 switch (ntohs(ar->ar_pro)) { 953 case ETHERTYPE_IP: 954 case ETHERTYPE_IPTRAILERS: 955 in_arpinput(m); 956 continue; 957 default: 958 ARP_STATINC(ARP_STAT_RCVBADPROTO); 959 } 960 else { 961 badlen: 962 ARP_STATINC(ARP_STAT_RCVBADLEN); 963 } 964 m_freem(m); 965 } 966 KERNEL_UNLOCK_ONE(NULL); 967 mutex_exit(softnet_lock); 968 } 969 970 /* 971 * ARP for Internet protocols on 10 Mb/s Ethernet. 972 * Algorithm is that given in RFC 826. 973 * In addition, a sanity check is performed on the sender 974 * protocol address, to catch impersonators. 975 * We no longer handle negotiations for use of trailer protocol: 976 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent 977 * along with IP replies if we wanted trailers sent to us, 978 * and also sent them in response to IP replies. 979 * This allowed either end to announce the desire to receive 980 * trailer packets. 981 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, 982 * but formerly didn't normally send requests. 983 */ 984 static void 985 in_arpinput(struct mbuf *m) 986 { 987 struct arphdr *ah; 988 struct ifnet *ifp, *rcvif = NULL; 989 struct llentry *la = NULL; 990 struct in_ifaddr *ia = NULL; 991 #if NBRIDGE > 0 992 struct in_ifaddr *bridge_ia = NULL; 993 #endif 994 #if NCARP > 0 995 u_int32_t count = 0, index = 0; 996 #endif 997 struct sockaddr sa; 998 struct in_addr isaddr, itaddr, myaddr; 999 int op; 1000 void *tha; 1001 uint64_t *arps; 1002 struct psref psref, psref_ia; 1003 int s; 1004 1005 if (__predict_false(m_makewritable(&m, 0, m->m_pkthdr.len, M_DONTWAIT))) 1006 goto out; 1007 ah = mtod(m, struct arphdr *); 1008 op = ntohs(ah->ar_op); 1009 1010 rcvif = ifp = m_get_rcvif_psref(m, &psref); 1011 if (__predict_false(rcvif == NULL)) 1012 goto drop; 1013 /* 1014 * Fix up ah->ar_hrd if necessary, before using ar_tha() or 1015 * ar_tpa(). 1016 */ 1017 switch (ifp->if_type) { 1018 case IFT_IEEE1394: 1019 if (ntohs(ah->ar_hrd) == ARPHRD_IEEE1394) 1020 ; 1021 else { 1022 /* XXX this is to make sure we compute ar_tha right */ 1023 /* XXX check ar_hrd more strictly? */ 1024 ah->ar_hrd = htons(ARPHRD_IEEE1394); 1025 } 1026 break; 1027 default: 1028 /* XXX check ar_hrd? */ 1029 break; 1030 } 1031 1032 memcpy(&isaddr, ar_spa(ah), sizeof (isaddr)); 1033 memcpy(&itaddr, ar_tpa(ah), sizeof (itaddr)); 1034 1035 if (m->m_flags & (M_BCAST|M_MCAST)) 1036 ARP_STATINC(ARP_STAT_RCVMCAST); 1037 1038 1039 /* 1040 * Search for a matching interface address 1041 * or any address on the interface to use 1042 * as a dummy address in the rest of this function 1043 */ 1044 s = pserialize_read_enter(); 1045 IN_ADDRHASH_READER_FOREACH(ia, itaddr.s_addr) { 1046 if (!in_hosteq(ia->ia_addr.sin_addr, itaddr)) 1047 continue; 1048 #if NCARP > 0 1049 if (ia->ia_ifp->if_type == IFT_CARP && 1050 ((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) == 1051 (IFF_UP|IFF_RUNNING))) { 1052 index++; 1053 if (ia->ia_ifp == rcvif && 1054 carp_iamatch(ia, ar_sha(ah), 1055 &count, index)) { 1056 break; 1057 } 1058 } else 1059 #endif 1060 if (ia->ia_ifp == rcvif) 1061 break; 1062 #if NBRIDGE > 0 1063 /* 1064 * If the interface we received the packet on 1065 * is part of a bridge, check to see if we need 1066 * to "bridge" the packet to ourselves at this 1067 * layer. Note we still prefer a perfect match, 1068 * but allow this weaker match if necessary. 1069 */ 1070 if (rcvif->if_bridge != NULL && 1071 rcvif->if_bridge == ia->ia_ifp->if_bridge) 1072 bridge_ia = ia; 1073 #endif /* NBRIDGE > 0 */ 1074 } 1075 1076 #if NBRIDGE > 0 1077 if (ia == NULL && bridge_ia != NULL) { 1078 ia = bridge_ia; 1079 m_put_rcvif_psref(rcvif, &psref); 1080 rcvif = NULL; 1081 /* FIXME */ 1082 ifp = bridge_ia->ia_ifp; 1083 } 1084 #endif 1085 if (ia != NULL) 1086 ia4_acquire(ia, &psref_ia); 1087 pserialize_read_exit(s); 1088 1089 if (ia == NULL) { 1090 ia = in_get_ia_on_iface_psref(isaddr, rcvif, &psref_ia); 1091 if (ia == NULL) { 1092 ia = in_get_ia_from_ifp_psref(ifp, &psref_ia); 1093 if (ia == NULL) { 1094 ARP_STATINC(ARP_STAT_RCVNOINT); 1095 goto out; 1096 } 1097 } 1098 } 1099 1100 myaddr = ia->ia_addr.sin_addr; 1101 1102 /* XXX checks for bridge case? */ 1103 if (!memcmp(ar_sha(ah), CLLADDR(ifp->if_sadl), ifp->if_addrlen)) { 1104 ARP_STATINC(ARP_STAT_RCVLOCALSHA); 1105 goto out; /* it's from me, ignore it. */ 1106 } 1107 1108 /* XXX checks for bridge case? */ 1109 if (!memcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 1110 ARP_STATINC(ARP_STAT_RCVBCASTSHA); 1111 log(LOG_ERR, 1112 "%s: arp: link address is broadcast for IP address %s!\n", 1113 ifp->if_xname, in_fmtaddr(isaddr)); 1114 goto out; 1115 } 1116 1117 /* 1118 * If the source IP address is zero, this is an RFC 5227 ARP probe 1119 */ 1120 if (in_nullhost(isaddr)) 1121 ARP_STATINC(ARP_STAT_RCVZEROSPA); 1122 else if (in_hosteq(isaddr, myaddr)) 1123 ARP_STATINC(ARP_STAT_RCVLOCALSPA); 1124 1125 if (in_nullhost(itaddr)) 1126 ARP_STATINC(ARP_STAT_RCVZEROTPA); 1127 1128 /* DAD check, RFC 5227 2.1.1, Probe Details */ 1129 if (in_hosteq(isaddr, myaddr) || 1130 (in_nullhost(isaddr) && in_hosteq(itaddr, myaddr))) 1131 { 1132 /* If our address is tentative, mark it as duplicated */ 1133 if (ia->ia4_flags & IN_IFF_TENTATIVE) 1134 arp_dad_duplicated((struct ifaddr *)ia); 1135 /* If our address is unuseable, don't reply */ 1136 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) 1137 goto out; 1138 } 1139 1140 /* 1141 * If the target IP address is zero, ignore the packet. 1142 * This prevents the code below from tring to answer 1143 * when we are using IP address zero (booting). 1144 */ 1145 if (in_nullhost(itaddr)) 1146 goto out; 1147 1148 if (in_nullhost(isaddr)) 1149 goto reply; 1150 1151 if (in_hosteq(isaddr, myaddr)) { 1152 log(LOG_ERR, 1153 "duplicate IP address %s sent from link address %s\n", 1154 in_fmtaddr(isaddr), lla_snprintf(ar_sha(ah), ah->ar_hln)); 1155 itaddr = myaddr; 1156 goto reply; 1157 } 1158 1159 if (in_hosteq(itaddr, myaddr)) 1160 la = arpcreate(ifp, m, &isaddr, NULL, 1); 1161 else 1162 la = arplookup(ifp, m, &isaddr, NULL, 1); 1163 if (la == NULL) 1164 goto reply; 1165 1166 if ((la->la_flags & LLE_VALID) && 1167 memcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) { 1168 if (la->la_flags & LLE_STATIC) { 1169 ARP_STATINC(ARP_STAT_RCVOVERPERM); 1170 if (!log_permanent_modify) 1171 goto out; 1172 log(LOG_INFO, 1173 "%s tried to overwrite permanent arp info" 1174 " for %s\n", 1175 lla_snprintf(ar_sha(ah), ah->ar_hln), 1176 in_fmtaddr(isaddr)); 1177 goto out; 1178 } else if (la->lle_tbl->llt_ifp != ifp) { 1179 /* XXX should not happen? */ 1180 ARP_STATINC(ARP_STAT_RCVOVERINT); 1181 if (!log_wrong_iface) 1182 goto out; 1183 log(LOG_INFO, 1184 "%s on %s tried to overwrite " 1185 "arp info for %s on %s\n", 1186 lla_snprintf(ar_sha(ah), ah->ar_hln), 1187 ifp->if_xname, in_fmtaddr(isaddr), 1188 la->lle_tbl->llt_ifp->if_xname); 1189 goto out; 1190 } else { 1191 ARP_STATINC(ARP_STAT_RCVOVER); 1192 if (log_movements) 1193 log(LOG_INFO, "arp info overwritten " 1194 "for %s by %s\n", 1195 in_fmtaddr(isaddr), 1196 lla_snprintf(ar_sha(ah), 1197 ah->ar_hln)); 1198 } 1199 } 1200 1201 /* XXX llentry should have addrlen? */ 1202 #if 0 1203 /* 1204 * sanity check for the address length. 1205 * XXX this does not work for protocols with variable address 1206 * length. -is 1207 */ 1208 if (sdl->sdl_alen && sdl->sdl_alen != ah->ar_hln) { 1209 ARP_STATINC(ARP_STAT_RCVLENCHG); 1210 log(LOG_WARNING, 1211 "arp from %s: new addr len %d, was %d\n", 1212 in_fmtaddr(isaddr), ah->ar_hln, sdl->sdl_alen); 1213 } 1214 #endif 1215 1216 if (ifp->if_addrlen != ah->ar_hln) { 1217 ARP_STATINC(ARP_STAT_RCVBADLEN); 1218 log(LOG_WARNING, 1219 "arp from %s: addr len: new %d, i/f %d (ignored)\n", 1220 in_fmtaddr(isaddr), ah->ar_hln, 1221 ifp->if_addrlen); 1222 goto reply; 1223 } 1224 1225 #if NTOKEN > 0 1226 /* 1227 * XXX uses m_data and assumes the complete answer including 1228 * XXX token-ring headers is in the same buf 1229 */ 1230 if (ifp->if_type == IFT_ISO88025) { 1231 struct token_header *trh; 1232 1233 trh = (struct token_header *)M_TRHSTART(m); 1234 if (trh->token_shost[0] & TOKEN_RI_PRESENT) { 1235 struct token_rif *rif; 1236 size_t riflen; 1237 1238 rif = TOKEN_RIF(trh); 1239 riflen = (ntohs(rif->tr_rcf) & 1240 TOKEN_RCF_LEN_MASK) >> 8; 1241 1242 if (riflen > 2 && 1243 riflen < sizeof(struct token_rif) && 1244 (riflen & 1) == 0) { 1245 rif->tr_rcf ^= htons(TOKEN_RCF_DIRECTION); 1246 rif->tr_rcf &= htons(~TOKEN_RCF_BROADCAST_MASK); 1247 memcpy(TOKEN_RIF_LLE(la), rif, riflen); 1248 } 1249 } 1250 } 1251 #endif /* NTOKEN > 0 */ 1252 1253 KASSERT(sizeof(la->ll_addr) >= ifp->if_addrlen); 1254 (void)memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen); 1255 la->la_flags |= LLE_VALID; 1256 if ((la->la_flags & LLE_STATIC) == 0) { 1257 la->la_expire = time_uptime + arpt_keep; 1258 arp_settimer(la, arpt_keep); 1259 } 1260 la->la_asked = 0; 1261 /* rt->rt_flags &= ~RTF_REJECT; */ 1262 1263 if (la->la_hold != NULL) { 1264 int n = la->la_numheld; 1265 struct mbuf *m_hold, *m_hold_next; 1266 struct sockaddr_in sin; 1267 1268 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 1269 1270 m_hold = la->la_hold; 1271 la->la_hold = NULL; 1272 la->la_numheld = 0; 1273 /* 1274 * We have to unlock here because if_output would call 1275 * arpresolve 1276 */ 1277 LLE_WUNLOCK(la); 1278 ARP_STATADD(ARP_STAT_DFRSENT, n); 1279 ARP_STATADD(ARP_STAT_DFRTOTAL, n); 1280 for (; m_hold != NULL; m_hold = m_hold_next) { 1281 m_hold_next = m_hold->m_nextpkt; 1282 m_hold->m_nextpkt = NULL; 1283 if_output_lock(ifp, ifp, m_hold, sintosa(&sin), NULL); 1284 } 1285 } else 1286 LLE_WUNLOCK(la); 1287 la = NULL; 1288 1289 reply: 1290 if (la != NULL) { 1291 LLE_WUNLOCK(la); 1292 la = NULL; 1293 } 1294 if (op != ARPOP_REQUEST) { 1295 if (op == ARPOP_REPLY) 1296 ARP_STATINC(ARP_STAT_RCVREPLY); 1297 goto out; 1298 } 1299 ARP_STATINC(ARP_STAT_RCVREQUEST); 1300 if (in_hosteq(itaddr, myaddr)) { 1301 /* If our address is unuseable, don't reply */ 1302 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) 1303 goto out; 1304 /* I am the target */ 1305 tha = ar_tha(ah); 1306 if (tha) 1307 memcpy(tha, ar_sha(ah), ah->ar_hln); 1308 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1309 } else { 1310 /* Proxy ARP */ 1311 struct llentry *lle = NULL; 1312 struct sockaddr_in sin; 1313 #if NCARP > 0 1314 struct ifnet *_rcvif = m_get_rcvif(m, &s); 1315 if (ifp->if_type == IFT_CARP && _rcvif->if_type != IFT_CARP) 1316 goto out; 1317 m_put_rcvif(_rcvif, &s); 1318 #endif 1319 1320 tha = ar_tha(ah); 1321 1322 sockaddr_in_init(&sin, &itaddr, 0); 1323 1324 IF_AFDATA_RLOCK(ifp); 1325 lle = lla_lookup(LLTABLE(ifp), 0, (struct sockaddr *)&sin); 1326 IF_AFDATA_RUNLOCK(ifp); 1327 1328 if ((lle != NULL) && (lle->la_flags & LLE_PUB)) { 1329 (void)memcpy(tha, ar_sha(ah), ah->ar_hln); 1330 (void)memcpy(ar_sha(ah), &lle->ll_addr, ah->ar_hln); 1331 LLE_RUNLOCK(lle); 1332 } else { 1333 if (lle != NULL) 1334 LLE_RUNLOCK(lle); 1335 goto drop; 1336 } 1337 } 1338 ia4_release(ia, &psref_ia); 1339 1340 memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); 1341 memcpy(ar_spa(ah), &itaddr, ah->ar_pln); 1342 ah->ar_op = htons(ARPOP_REPLY); 1343 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 1344 switch (ifp->if_type) { 1345 case IFT_IEEE1394: 1346 /* 1347 * ieee1394 arp reply is broadcast 1348 */ 1349 m->m_flags &= ~M_MCAST; 1350 m->m_flags |= M_BCAST; 1351 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + ah->ar_hln; 1352 break; 1353 1354 default: 1355 m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */ 1356 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); 1357 break; 1358 } 1359 m->m_pkthdr.len = m->m_len; 1360 sa.sa_family = AF_ARP; 1361 sa.sa_len = 2; 1362 arps = ARP_STAT_GETREF(); 1363 arps[ARP_STAT_SNDTOTAL]++; 1364 arps[ARP_STAT_SNDREPLY]++; 1365 ARP_STAT_PUTREF(); 1366 if_output_lock(ifp, ifp, m, &sa, NULL); 1367 if (rcvif != NULL) 1368 m_put_rcvif_psref(rcvif, &psref); 1369 return; 1370 1371 out: 1372 if (la != NULL) 1373 LLE_WUNLOCK(la); 1374 drop: 1375 if (ia != NULL) 1376 ia4_release(ia, &psref_ia); 1377 if (rcvif != NULL) 1378 m_put_rcvif_psref(rcvif, &psref); 1379 m_freem(m); 1380 } 1381 1382 /* 1383 * Lookup or a new address in arptab. 1384 */ 1385 static struct llentry * 1386 arplookup(struct ifnet *ifp, struct mbuf *m, const struct in_addr *addr, 1387 const struct sockaddr *sa, int wlock) 1388 { 1389 struct sockaddr_in sin; 1390 struct llentry *la; 1391 int flags = wlock ? LLE_EXCLUSIVE : 0; 1392 1393 1394 if (sa == NULL) { 1395 KASSERT(addr != NULL); 1396 sockaddr_in_init(&sin, addr, 0); 1397 sa = sintocsa(&sin); 1398 } 1399 1400 IF_AFDATA_RLOCK(ifp); 1401 la = lla_lookup(LLTABLE(ifp), flags, sa); 1402 IF_AFDATA_RUNLOCK(ifp); 1403 1404 return la; 1405 } 1406 1407 static struct llentry * 1408 arpcreate(struct ifnet *ifp, struct mbuf *m, const struct in_addr *addr, 1409 const struct sockaddr *sa, int wlock) 1410 { 1411 struct sockaddr_in sin; 1412 struct llentry *la; 1413 int flags = wlock ? LLE_EXCLUSIVE : 0; 1414 1415 if (sa == NULL) { 1416 KASSERT(addr != NULL); 1417 sockaddr_in_init(&sin, addr, 0); 1418 sa = sintocsa(&sin); 1419 } 1420 1421 la = arplookup(ifp, m, addr, sa, wlock); 1422 1423 if (la == NULL) { 1424 IF_AFDATA_WLOCK(ifp); 1425 la = lla_create(LLTABLE(ifp), flags, sa); 1426 IF_AFDATA_WUNLOCK(ifp); 1427 1428 if (la != NULL) 1429 arp_init_llentry(ifp, la); 1430 } 1431 1432 return la; 1433 } 1434 1435 int 1436 arpioctl(u_long cmd, void *data) 1437 { 1438 1439 return EOPNOTSUPP; 1440 } 1441 1442 void 1443 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1444 { 1445 struct in_addr *ip; 1446 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1447 1448 /* 1449 * Warn the user if another station has this IP address, 1450 * but only if the interface IP address is not zero. 1451 */ 1452 ip = &IA_SIN(ifa)->sin_addr; 1453 if (!in_nullhost(*ip) && 1454 (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) == 0) { 1455 struct llentry *lle; 1456 1457 arprequest(ifp, ip, ip, CLLADDR(ifp->if_sadl)); 1458 1459 /* 1460 * interface address is considered static entry 1461 * because the output of the arp utility shows 1462 * that L2 entry as permanent 1463 */ 1464 IF_AFDATA_WLOCK(ifp); 1465 lle = lla_create(LLTABLE(ifp), (LLE_IFADDR | LLE_STATIC), 1466 (struct sockaddr *)IA_SIN(ifa)); 1467 IF_AFDATA_WUNLOCK(ifp); 1468 if (lle == NULL) 1469 log(LOG_INFO, "%s: cannot create arp entry for" 1470 " interface address\n", __func__); 1471 else { 1472 arp_init_llentry(ifp, lle); 1473 LLE_RUNLOCK(lle); 1474 } 1475 } 1476 1477 ifa->ifa_rtrequest = arp_rtrequest; 1478 ifa->ifa_flags |= RTF_CONNECTED; 1479 1480 /* ARP will handle DAD for this address. */ 1481 if (ia->ia4_flags & IN_IFF_TRYTENTATIVE) { 1482 ia->ia4_flags |= IN_IFF_TENTATIVE; 1483 ia->ia_dad_start = arp_dad_start; 1484 ia->ia_dad_stop = arp_dad_stop; 1485 } 1486 } 1487 1488 TAILQ_HEAD(dadq_head, dadq); 1489 struct dadq { 1490 TAILQ_ENTRY(dadq) dad_list; 1491 struct ifaddr *dad_ifa; 1492 int dad_count; /* max ARP to send */ 1493 int dad_arp_tcount; /* # of trials to send ARP */ 1494 int dad_arp_ocount; /* ARP sent so far */ 1495 int dad_arp_announce; /* max ARP announcements */ 1496 int dad_arp_acount; /* # of announcements */ 1497 struct callout dad_timer_ch; 1498 }; 1499 MALLOC_JUSTDEFINE(M_IPARP, "ARP DAD", "ARP DAD Structure"); 1500 1501 static struct dadq_head dadq; 1502 static int dad_init = 0; 1503 static int dad_maxtry = 15; /* max # of *tries* to transmit DAD packet */ 1504 static kmutex_t arp_dad_lock; 1505 1506 static struct dadq * 1507 arp_dad_find(struct ifaddr *ifa) 1508 { 1509 struct dadq *dp; 1510 1511 KASSERT(mutex_owned(&arp_dad_lock)); 1512 1513 TAILQ_FOREACH(dp, &dadq, dad_list) { 1514 if (dp->dad_ifa == ifa) 1515 return dp; 1516 } 1517 return NULL; 1518 } 1519 1520 static void 1521 arp_dad_starttimer(struct dadq *dp, int ticks) 1522 { 1523 1524 callout_reset(&dp->dad_timer_ch, ticks, 1525 (void (*)(void *))arp_dad_timer, (void *)dp->dad_ifa); 1526 } 1527 1528 static void 1529 arp_dad_stoptimer(struct dadq *dp) 1530 { 1531 1532 callout_halt(&dp->dad_timer_ch, softnet_lock); 1533 } 1534 1535 static void 1536 arp_dad_output(struct dadq *dp, struct ifaddr *ifa) 1537 { 1538 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1539 struct ifnet *ifp = ifa->ifa_ifp; 1540 struct in_addr sip; 1541 1542 dp->dad_arp_tcount++; 1543 if ((ifp->if_flags & IFF_UP) == 0) 1544 return; 1545 if ((ifp->if_flags & IFF_RUNNING) == 0) 1546 return; 1547 1548 dp->dad_arp_tcount = 0; 1549 dp->dad_arp_ocount++; 1550 1551 memset(&sip, 0, sizeof(sip)); 1552 arprequest(ifa->ifa_ifp, &sip, &ia->ia_addr.sin_addr, 1553 CLLADDR(ifa->ifa_ifp->if_sadl)); 1554 } 1555 1556 /* 1557 * Start Duplicate Address Detection (DAD) for specified interface address. 1558 */ 1559 static void 1560 arp_dad_start(struct ifaddr *ifa) 1561 { 1562 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1563 struct dadq *dp; 1564 1565 if (!dad_init) { 1566 TAILQ_INIT(&dadq); 1567 mutex_init(&arp_dad_lock, MUTEX_DEFAULT, IPL_NONE); 1568 dad_init++; 1569 } 1570 1571 /* 1572 * If we don't need DAD, don't do it. 1573 * - DAD is disabled (ip_dad_count == 0) 1574 */ 1575 if (!(ia->ia4_flags & IN_IFF_TENTATIVE)) { 1576 log(LOG_DEBUG, 1577 "%s: called with non-tentative address %s(%s)\n", __func__, 1578 in_fmtaddr(ia->ia_addr.sin_addr), 1579 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1580 return; 1581 } 1582 if (!ip_dad_count) { 1583 struct in_addr *ip = &IA_SIN(ifa)->sin_addr; 1584 1585 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1586 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1587 arprequest(ifa->ifa_ifp, ip, ip, 1588 CLLADDR(ifa->ifa_ifp->if_sadl)); 1589 return; 1590 } 1591 KASSERT(ifa->ifa_ifp != NULL); 1592 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) 1593 return; 1594 1595 mutex_enter(&arp_dad_lock); 1596 if (arp_dad_find(ifa) != NULL) { 1597 mutex_exit(&arp_dad_lock); 1598 /* DAD already in progress */ 1599 return; 1600 } 1601 1602 dp = malloc(sizeof(*dp), M_IPARP, M_NOWAIT); 1603 if (dp == NULL) { 1604 mutex_exit(&arp_dad_lock); 1605 log(LOG_ERR, "%s: memory allocation failed for %s(%s)\n", 1606 __func__, in_fmtaddr(ia->ia_addr.sin_addr), 1607 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1608 return; 1609 } 1610 memset(dp, 0, sizeof(*dp)); 1611 callout_init(&dp->dad_timer_ch, CALLOUT_MPSAFE); 1612 1613 /* 1614 * Send ARP packet for DAD, ip_dad_count times. 1615 * Note that we must delay the first transmission. 1616 */ 1617 dp->dad_ifa = ifa; 1618 ifaref(ifa); /* just for safety */ 1619 dp->dad_count = ip_dad_count; 1620 dp->dad_arp_announce = 0; /* Will be set when starting to announce */ 1621 dp->dad_arp_acount = dp->dad_arp_ocount = dp->dad_arp_tcount = 0; 1622 TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list); 1623 1624 arplog((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1625 in_fmtaddr(ia->ia_addr.sin_addr))); 1626 1627 arp_dad_starttimer(dp, cprng_fast32() % (PROBE_WAIT * hz)); 1628 1629 mutex_exit(&arp_dad_lock); 1630 } 1631 1632 /* 1633 * terminate DAD unconditionally. used for address removals. 1634 */ 1635 static void 1636 arp_dad_stop(struct ifaddr *ifa) 1637 { 1638 struct dadq *dp; 1639 1640 if (!dad_init) 1641 return; 1642 1643 mutex_enter(&arp_dad_lock); 1644 dp = arp_dad_find(ifa); 1645 if (dp == NULL) { 1646 mutex_exit(&arp_dad_lock); 1647 /* DAD wasn't started yet */ 1648 return; 1649 } 1650 1651 /* Prevent the timer from running anymore. */ 1652 TAILQ_REMOVE(&dadq, dp, dad_list); 1653 mutex_exit(&arp_dad_lock); 1654 1655 arp_dad_stoptimer(dp); 1656 1657 free(dp, M_IPARP); 1658 dp = NULL; 1659 ifafree(ifa); 1660 } 1661 1662 static void 1663 arp_dad_timer(struct ifaddr *ifa) 1664 { 1665 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1666 struct dadq *dp; 1667 struct in_addr *ip; 1668 1669 mutex_enter(softnet_lock); 1670 KERNEL_LOCK(1, NULL); 1671 mutex_enter(&arp_dad_lock); 1672 1673 /* Sanity check */ 1674 if (ia == NULL) { 1675 log(LOG_ERR, "%s: called with null parameter\n", __func__); 1676 goto done; 1677 } 1678 dp = arp_dad_find(ifa); 1679 if (dp == NULL) { 1680 /* DAD seems to be stopping, so do nothing. */ 1681 goto done; 1682 } 1683 if (ia->ia4_flags & IN_IFF_DUPLICATED) { 1684 log(LOG_ERR, "%s: called with duplicate address %s(%s)\n", 1685 __func__, in_fmtaddr(ia->ia_addr.sin_addr), 1686 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1687 goto done; 1688 } 1689 if ((ia->ia4_flags & IN_IFF_TENTATIVE) == 0 && dp->dad_arp_acount == 0) 1690 { 1691 log(LOG_ERR, "%s: called with non-tentative address %s(%s)\n", 1692 __func__, in_fmtaddr(ia->ia_addr.sin_addr), 1693 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1694 goto done; 1695 } 1696 1697 /* timeouted with IFF_{RUNNING,UP} check */ 1698 if (dp->dad_arp_tcount > dad_maxtry) { 1699 arplog((LOG_INFO, "%s: could not run DAD, driver problem?\n", 1700 if_name(ifa->ifa_ifp))); 1701 1702 TAILQ_REMOVE(&dadq, dp, dad_list); 1703 free(dp, M_IPARP); 1704 dp = NULL; 1705 ifafree(ifa); 1706 goto done; 1707 } 1708 1709 /* Need more checks? */ 1710 if (dp->dad_arp_ocount < dp->dad_count) { 1711 int adelay; 1712 1713 /* 1714 * We have more ARP to go. Send ARP packet for DAD. 1715 */ 1716 arp_dad_output(dp, ifa); 1717 if (dp->dad_arp_ocount < dp->dad_count) 1718 adelay = (PROBE_MIN * hz) + 1719 (cprng_fast32() % 1720 ((PROBE_MAX * hz) - (PROBE_MIN * hz))); 1721 else 1722 adelay = ANNOUNCE_WAIT * hz; 1723 arp_dad_starttimer(dp, adelay); 1724 goto done; 1725 } else if (dp->dad_arp_acount == 0) { 1726 /* 1727 * We are done with DAD. 1728 * No duplicate address found. 1729 */ 1730 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1731 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1732 arplog((LOG_DEBUG, 1733 "%s: DAD complete for %s - no duplicates found\n", 1734 if_name(ifa->ifa_ifp), 1735 in_fmtaddr(ia->ia_addr.sin_addr))); 1736 dp->dad_arp_announce = ANNOUNCE_NUM; 1737 goto announce; 1738 } else if (dp->dad_arp_acount < dp->dad_arp_announce) { 1739 announce: 1740 /* 1741 * Announce the address. 1742 */ 1743 ip = &IA_SIN(ifa)->sin_addr; 1744 arprequest(ifa->ifa_ifp, ip, ip, 1745 CLLADDR(ifa->ifa_ifp->if_sadl)); 1746 dp->dad_arp_acount++; 1747 if (dp->dad_arp_acount < dp->dad_arp_announce) { 1748 arp_dad_starttimer(dp, ANNOUNCE_INTERVAL * hz); 1749 goto done; 1750 } 1751 arplog((LOG_DEBUG, 1752 "%s: ARP announcement complete for %s\n", 1753 if_name(ifa->ifa_ifp), 1754 in_fmtaddr(ia->ia_addr.sin_addr))); 1755 } 1756 1757 TAILQ_REMOVE(&dadq, dp, dad_list); 1758 free(dp, M_IPARP); 1759 dp = NULL; 1760 ifafree(ifa); 1761 1762 done: 1763 mutex_exit(&arp_dad_lock); 1764 KERNEL_UNLOCK_ONE(NULL); 1765 mutex_exit(softnet_lock); 1766 } 1767 1768 static void 1769 arp_dad_duplicated(struct ifaddr *ifa) 1770 { 1771 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1772 struct ifnet *ifp; 1773 struct dadq *dp; 1774 1775 mutex_enter(&arp_dad_lock); 1776 dp = arp_dad_find(ifa); 1777 if (dp == NULL) { 1778 mutex_exit(&arp_dad_lock); 1779 /* DAD seems to be stopping, so do nothing. */ 1780 return; 1781 } 1782 1783 ifp = ifa->ifa_ifp; 1784 log(LOG_ERR, 1785 "%s: DAD detected duplicate IPv4 address %s: ARP out=%d\n", 1786 if_name(ifp), in_fmtaddr(ia->ia_addr.sin_addr), 1787 dp->dad_arp_ocount); 1788 1789 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1790 ia->ia4_flags |= IN_IFF_DUPLICATED; 1791 1792 /* We are done with DAD, with duplicated address found. (failure) */ 1793 arp_dad_stoptimer(dp); 1794 1795 /* Inform the routing socket that DAD has completed */ 1796 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1797 1798 TAILQ_REMOVE(&dadq, dp, dad_list); 1799 mutex_exit(&arp_dad_lock); 1800 1801 free(dp, M_IPARP); 1802 dp = NULL; 1803 ifafree(ifa); 1804 } 1805 1806 /* 1807 * Called from 10 Mb/s Ethernet interrupt handlers 1808 * when ether packet type ETHERTYPE_REVARP 1809 * is received. Common length and type checks are done here, 1810 * then the protocol-specific routine is called. 1811 */ 1812 void 1813 revarpinput(struct mbuf *m) 1814 { 1815 struct arphdr *ar; 1816 1817 if (m->m_len < sizeof(struct arphdr)) 1818 goto out; 1819 ar = mtod(m, struct arphdr *); 1820 #if 0 /* XXX I don't think we need this... and it will prevent other LL */ 1821 if (ntohs(ar->ar_hrd) != ARPHRD_ETHER) 1822 goto out; 1823 #endif 1824 if (m->m_len < sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln)) 1825 goto out; 1826 switch (ntohs(ar->ar_pro)) { 1827 case ETHERTYPE_IP: 1828 case ETHERTYPE_IPTRAILERS: 1829 in_revarpinput(m); 1830 return; 1831 1832 default: 1833 break; 1834 } 1835 out: 1836 m_freem(m); 1837 } 1838 1839 /* 1840 * RARP for Internet protocols on 10 Mb/s Ethernet. 1841 * Algorithm is that given in RFC 903. 1842 * We are only using for bootstrap purposes to get an ip address for one of 1843 * our interfaces. Thus we support no user-interface. 1844 * 1845 * Since the contents of the RARP reply are specific to the interface that 1846 * sent the request, this code must ensure that they are properly associated. 1847 * 1848 * Note: also supports ARP via RARP packets, per the RFC. 1849 */ 1850 void 1851 in_revarpinput(struct mbuf *m) 1852 { 1853 struct arphdr *ah; 1854 void *tha; 1855 int op; 1856 struct ifnet *rcvif; 1857 int s; 1858 1859 ah = mtod(m, struct arphdr *); 1860 op = ntohs(ah->ar_op); 1861 1862 rcvif = m_get_rcvif(m, &s); 1863 switch (rcvif->if_type) { 1864 case IFT_IEEE1394: 1865 /* ARP without target hardware address is not supported */ 1866 goto out; 1867 default: 1868 break; 1869 } 1870 1871 switch (op) { 1872 case ARPOP_REQUEST: 1873 case ARPOP_REPLY: /* per RFC */ 1874 m_put_rcvif(rcvif, &s); 1875 in_arpinput(m); 1876 return; 1877 case ARPOP_REVREPLY: 1878 break; 1879 case ARPOP_REVREQUEST: /* handled by rarpd(8) */ 1880 default: 1881 goto out; 1882 } 1883 if (!revarp_in_progress) 1884 goto out; 1885 if (rcvif != myip_ifp) /* !same interface */ 1886 goto out; 1887 if (myip_initialized) 1888 goto wake; 1889 tha = ar_tha(ah); 1890 if (tha == NULL) 1891 goto out; 1892 if (memcmp(tha, CLLADDR(rcvif->if_sadl), rcvif->if_sadl->sdl_alen)) 1893 goto out; 1894 memcpy(&srv_ip, ar_spa(ah), sizeof(srv_ip)); 1895 memcpy(&myip, ar_tpa(ah), sizeof(myip)); 1896 myip_initialized = 1; 1897 wake: /* Do wakeup every time in case it was missed. */ 1898 wakeup((void *)&myip); 1899 1900 out: 1901 m_put_rcvif(rcvif, &s); 1902 m_freem(m); 1903 } 1904 1905 /* 1906 * Send a RARP request for the ip address of the specified interface. 1907 * The request should be RFC 903-compliant. 1908 */ 1909 static void 1910 revarprequest(struct ifnet *ifp) 1911 { 1912 struct sockaddr sa; 1913 struct mbuf *m; 1914 struct arphdr *ah; 1915 void *tha; 1916 1917 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 1918 return; 1919 MCLAIM(m, &arpdomain.dom_mowner); 1920 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) + 1921 2*ifp->if_addrlen; 1922 m->m_pkthdr.len = m->m_len; 1923 MH_ALIGN(m, m->m_len); 1924 ah = mtod(m, struct arphdr *); 1925 memset(ah, 0, m->m_len); 1926 ah->ar_pro = htons(ETHERTYPE_IP); 1927 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 1928 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 1929 ah->ar_op = htons(ARPOP_REVREQUEST); 1930 1931 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1932 tha = ar_tha(ah); 1933 if (tha == NULL) { 1934 m_free(m); 1935 return; 1936 } 1937 memcpy(tha, CLLADDR(ifp->if_sadl), ah->ar_hln); 1938 1939 sa.sa_family = AF_ARP; 1940 sa.sa_len = 2; 1941 m->m_flags |= M_BCAST; 1942 1943 if_output_lock(ifp, ifp, m, &sa, NULL); 1944 } 1945 1946 /* 1947 * RARP for the ip address of the specified interface, but also 1948 * save the ip address of the server that sent the answer. 1949 * Timeout if no response is received. 1950 */ 1951 int 1952 revarpwhoarewe(struct ifnet *ifp, struct in_addr *serv_in, 1953 struct in_addr *clnt_in) 1954 { 1955 int result, count = 20; 1956 1957 myip_initialized = 0; 1958 myip_ifp = ifp; 1959 1960 revarp_in_progress = 1; 1961 while (count--) { 1962 revarprequest(ifp); 1963 result = tsleep((void *)&myip, PSOCK, "revarp", hz/2); 1964 if (result != EWOULDBLOCK) 1965 break; 1966 } 1967 revarp_in_progress = 0; 1968 1969 if (!myip_initialized) 1970 return ENETUNREACH; 1971 1972 memcpy(serv_in, &srv_ip, sizeof(*serv_in)); 1973 memcpy(clnt_in, &myip, sizeof(*clnt_in)); 1974 return 0; 1975 } 1976 1977 void 1978 arp_stat_add(int type, uint64_t count) 1979 { 1980 ARP_STATADD(type, count); 1981 } 1982 1983 static int 1984 sysctl_net_inet_arp_stats(SYSCTLFN_ARGS) 1985 { 1986 1987 return NETSTAT_SYSCTL(arpstat_percpu, ARP_NSTATS); 1988 } 1989 1990 static void 1991 sysctl_net_inet_arp_setup(struct sysctllog **clog) 1992 { 1993 const struct sysctlnode *node; 1994 1995 sysctl_createv(clog, 0, NULL, NULL, 1996 CTLFLAG_PERMANENT, 1997 CTLTYPE_NODE, "inet", NULL, 1998 NULL, 0, NULL, 0, 1999 CTL_NET, PF_INET, CTL_EOL); 2000 sysctl_createv(clog, 0, NULL, &node, 2001 CTLFLAG_PERMANENT, 2002 CTLTYPE_NODE, "arp", 2003 SYSCTL_DESCR("Address Resolution Protocol"), 2004 NULL, 0, NULL, 0, 2005 CTL_NET, PF_INET, CTL_CREATE, CTL_EOL); 2006 2007 sysctl_createv(clog, 0, NULL, NULL, 2008 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2009 CTLTYPE_INT, "keep", 2010 SYSCTL_DESCR("Valid ARP entry lifetime in seconds"), 2011 NULL, 0, &arpt_keep, 0, 2012 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2013 2014 sysctl_createv(clog, 0, NULL, NULL, 2015 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2016 CTLTYPE_INT, "down", 2017 SYSCTL_DESCR("Failed ARP entry lifetime in seconds"), 2018 NULL, 0, &arpt_down, 0, 2019 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2020 2021 sysctl_createv(clog, 0, NULL, NULL, 2022 CTLFLAG_PERMANENT, 2023 CTLTYPE_STRUCT, "stats", 2024 SYSCTL_DESCR("ARP statistics"), 2025 sysctl_net_inet_arp_stats, 0, NULL, 0, 2026 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2027 2028 sysctl_createv(clog, 0, NULL, NULL, 2029 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2030 CTLTYPE_INT, "log_movements", 2031 SYSCTL_DESCR("log ARP replies from MACs different than" 2032 " the one in the cache"), 2033 NULL, 0, &log_movements, 0, 2034 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2035 2036 sysctl_createv(clog, 0, NULL, NULL, 2037 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2038 CTLTYPE_INT, "log_permanent_modify", 2039 SYSCTL_DESCR("log ARP replies from MACs different than" 2040 " the one in the permanent arp entry"), 2041 NULL, 0, &log_permanent_modify, 0, 2042 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2043 2044 sysctl_createv(clog, 0, NULL, NULL, 2045 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2046 CTLTYPE_INT, "log_wrong_iface", 2047 SYSCTL_DESCR("log ARP packets arriving on the wrong" 2048 " interface"), 2049 NULL, 0, &log_wrong_iface, 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_unknown_network", 2055 SYSCTL_DESCR("log ARP packets from non-local network"), 2056 NULL, 0, &log_unknown_network, 0, 2057 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2058 2059 sysctl_createv(clog, 0, NULL, NULL, 2060 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2061 CTLTYPE_INT, "debug", 2062 SYSCTL_DESCR("Enable ARP DAD debug output"), 2063 NULL, 0, &arp_debug, 0, 2064 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2065 } 2066 2067 #endif /* INET */ 2068