1 /* $NetBSD: if_arp.c,v 1.233 2016/12/12 03:55:57 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 1.233 2016/12/12 03:55:57 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/malloc.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 #define SIN(s) ((struct sockaddr_in *)s) 137 #define SRP(s) ((struct sockaddr_inarp *)s) 138 139 /* 140 * ARP trailer negotiation. Trailer protocol is not IP specific, 141 * but ARP request/response use IP addresses. 142 */ 143 #define ETHERTYPE_IPTRAILERS ETHERTYPE_TRAIL 144 145 /* timer values */ 146 static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */ 147 static int arpt_down = 20; /* once declared down, don't send for 20 secs */ 148 static int arp_maxhold = 1; /* number of packets to hold per ARP entry */ 149 #define rt_expire rt_rmx.rmx_expire 150 #define rt_pksent rt_rmx.rmx_pksent 151 152 int ip_dad_count = PROBE_NUM; 153 #ifdef ARP_DEBUG 154 int arp_debug = 1; 155 #else 156 int arp_debug = 0; 157 #endif 158 159 static void arp_init(void); 160 161 static void arprequest(struct ifnet *, 162 const struct in_addr *, const struct in_addr *, 163 const u_int8_t *); 164 static void arpannounce1(struct ifaddr *); 165 static struct sockaddr *arp_setgate(struct rtentry *, struct sockaddr *, 166 const struct sockaddr *); 167 static void arptimer(void *); 168 static void arp_settimer(struct llentry *, int); 169 static struct llentry *arplookup(struct ifnet *, struct mbuf *, 170 const struct in_addr *, const struct sockaddr *, int); 171 static struct llentry *arpcreate(struct ifnet *, struct mbuf *, 172 const struct in_addr *, const struct sockaddr *, int); 173 static void in_arpinput(struct mbuf *); 174 static void in_revarpinput(struct mbuf *); 175 static void revarprequest(struct ifnet *); 176 177 static void arp_drainstub(void); 178 179 static void arp_dad_timer(struct ifaddr *); 180 static void arp_dad_start(struct ifaddr *); 181 static void arp_dad_stop(struct ifaddr *); 182 static void arp_dad_duplicated(struct ifaddr *, const char *); 183 184 static void arp_init_llentry(struct ifnet *, struct llentry *); 185 #if NTOKEN > 0 186 static void arp_free_llentry_tokenring(struct llentry *); 187 #endif 188 189 struct ifqueue arpintrq = { 190 .ifq_head = NULL, 191 .ifq_tail = NULL, 192 .ifq_len = 0, 193 .ifq_maxlen = 50, 194 .ifq_drops = 0, 195 }; 196 static int arp_maxtries = 5; 197 static int useloopback = 1; /* use loopback interface for local traffic */ 198 199 static percpu_t *arpstat_percpu; 200 201 #define ARP_STAT_GETREF() _NET_STAT_GETREF(arpstat_percpu) 202 #define ARP_STAT_PUTREF() _NET_STAT_PUTREF(arpstat_percpu) 203 204 #define ARP_STATINC(x) _NET_STATINC(arpstat_percpu, x) 205 #define ARP_STATADD(x, v) _NET_STATADD(arpstat_percpu, x, v) 206 207 /* revarp state */ 208 static struct in_addr myip, srv_ip; 209 static int myip_initialized = 0; 210 static int revarp_in_progress = 0; 211 static struct ifnet *myip_ifp = NULL; 212 213 static int arp_drainwanted; 214 215 static int log_movements = 1; 216 static int log_permanent_modify = 1; 217 static int log_wrong_iface = 1; 218 static int log_unknown_network = 1; 219 220 /* 221 * this should be elsewhere. 222 */ 223 224 static char * 225 lla_snprintf(u_int8_t *, int); 226 227 static char * 228 lla_snprintf(u_int8_t *adrp, int len) 229 { 230 #define NUMBUFS 3 231 static char buf[NUMBUFS][16*3]; 232 static int bnum = 0; 233 234 int i; 235 char *p; 236 237 p = buf[bnum]; 238 239 *p++ = hexdigits[(*adrp)>>4]; 240 *p++ = hexdigits[(*adrp++)&0xf]; 241 242 for (i=1; i<len && i<16; i++) { 243 *p++ = ':'; 244 *p++ = hexdigits[(*adrp)>>4]; 245 *p++ = hexdigits[(*adrp++)&0xf]; 246 } 247 248 *p = 0; 249 p = buf[bnum]; 250 bnum = (bnum + 1) % NUMBUFS; 251 return p; 252 } 253 254 DOMAIN_DEFINE(arpdomain); /* forward declare and add to link set */ 255 256 static void 257 arp_fasttimo(void) 258 { 259 if (arp_drainwanted) { 260 arp_drain(); 261 arp_drainwanted = 0; 262 } 263 } 264 265 const struct protosw arpsw[] = { 266 { .pr_type = 0, 267 .pr_domain = &arpdomain, 268 .pr_protocol = 0, 269 .pr_flags = 0, 270 .pr_input = 0, 271 .pr_ctlinput = 0, 272 .pr_ctloutput = 0, 273 .pr_usrreqs = 0, 274 .pr_init = arp_init, 275 .pr_fasttimo = arp_fasttimo, 276 .pr_slowtimo = 0, 277 .pr_drain = arp_drainstub, 278 } 279 }; 280 281 struct domain arpdomain = { 282 .dom_family = PF_ARP, 283 .dom_name = "arp", 284 .dom_protosw = arpsw, 285 .dom_protoswNPROTOSW = &arpsw[__arraycount(arpsw)], 286 }; 287 288 static void sysctl_net_inet_arp_setup(struct sysctllog **); 289 290 void 291 arp_init(void) 292 { 293 294 sysctl_net_inet_arp_setup(NULL); 295 arpstat_percpu = percpu_alloc(sizeof(uint64_t) * ARP_NSTATS); 296 IFQ_LOCK_INIT(&arpintrq); 297 } 298 299 static void 300 arp_drainstub(void) 301 { 302 arp_drainwanted = 1; 303 } 304 305 /* 306 * ARP protocol drain routine. Called when memory is in short supply. 307 * Called at splvm(); don't acquire softnet_lock as can be called from 308 * hardware interrupt handlers. 309 */ 310 void 311 arp_drain(void) 312 { 313 314 lltable_drain(AF_INET); 315 } 316 317 static void 318 arptimer(void *arg) 319 { 320 struct llentry *lle = arg; 321 struct ifnet *ifp; 322 323 if (lle == NULL) 324 return; 325 326 if (lle->la_flags & LLE_STATIC) 327 return; 328 329 LLE_WLOCK(lle); 330 if (callout_pending(&lle->la_timer)) { 331 /* 332 * Here we are a bit odd here in the treatment of 333 * active/pending. If the pending bit is set, it got 334 * rescheduled before I ran. The active 335 * bit we ignore, since if it was stopped 336 * in ll_tablefree() and was currently running 337 * it would have return 0 so the code would 338 * not have deleted it since the callout could 339 * not be stopped so we want to go through 340 * with the delete here now. If the callout 341 * was restarted, the pending bit will be back on and 342 * we just want to bail since the callout_reset would 343 * return 1 and our reference would have been removed 344 * by arpresolve() below. 345 */ 346 LLE_WUNLOCK(lle); 347 return; 348 } 349 ifp = lle->lle_tbl->llt_ifp; 350 351 callout_stop(&lle->la_timer); 352 353 /* XXX: LOR avoidance. We still have ref on lle. */ 354 LLE_WUNLOCK(lle); 355 356 IF_AFDATA_LOCK(ifp); 357 LLE_WLOCK(lle); 358 359 /* Guard against race with other llentry_free(). */ 360 if (lle->la_flags & LLE_LINKED) { 361 size_t pkts_dropped; 362 363 LLE_REMREF(lle); 364 pkts_dropped = llentry_free(lle); 365 ARP_STATADD(ARP_STAT_DFRDROPPED, pkts_dropped); 366 ARP_STATADD(ARP_STAT_DFRTOTAL, pkts_dropped); 367 } else { 368 LLE_FREE_LOCKED(lle); 369 } 370 371 IF_AFDATA_UNLOCK(ifp); 372 } 373 374 static void 375 arp_settimer(struct llentry *la, int sec) 376 { 377 378 LLE_WLOCK_ASSERT(la); 379 LLE_ADDREF(la); 380 callout_reset(&la->la_timer, hz * sec, arptimer, la); 381 } 382 383 /* 384 * We set the gateway for RTF_CLONING routes to a "prototype" 385 * link-layer sockaddr whose interface type (if_type) and interface 386 * index (if_index) fields are prepared. 387 */ 388 static struct sockaddr * 389 arp_setgate(struct rtentry *rt, struct sockaddr *gate, 390 const struct sockaddr *netmask) 391 { 392 const struct ifnet *ifp = rt->rt_ifp; 393 uint8_t namelen = strlen(ifp->if_xname); 394 uint8_t addrlen = ifp->if_addrlen; 395 396 /* 397 * XXX: If this is a manually added route to interface 398 * such as older version of routed or gated might provide, 399 * restore cloning bit. 400 */ 401 if ((rt->rt_flags & RTF_HOST) == 0 && netmask != NULL && 402 satocsin(netmask)->sin_addr.s_addr != 0xffffffff) 403 rt->rt_flags |= RTF_CONNECTED; 404 405 if ((rt->rt_flags & (RTF_CONNECTED | RTF_LOCAL))) { 406 union { 407 struct sockaddr sa; 408 struct sockaddr_storage ss; 409 struct sockaddr_dl sdl; 410 } u; 411 /* 412 * Case 1: This route should come from a route to iface. 413 */ 414 sockaddr_dl_init(&u.sdl, sizeof(u.ss), 415 ifp->if_index, ifp->if_type, NULL, namelen, NULL, addrlen); 416 rt_setgate(rt, &u.sa); 417 gate = rt->rt_gateway; 418 } 419 return gate; 420 } 421 422 static void 423 arp_init_llentry(struct ifnet *ifp, struct llentry *lle) 424 { 425 426 switch (ifp->if_type) { 427 #if NTOKEN > 0 428 case IFT_ISO88025: 429 lle->la_opaque = kmem_intr_alloc(sizeof(struct token_rif), 430 KM_NOSLEEP); 431 lle->lle_ll_free = arp_free_llentry_tokenring; 432 break; 433 #endif 434 } 435 } 436 437 #if NTOKEN > 0 438 static void 439 arp_free_llentry_tokenring(struct llentry *lle) 440 { 441 442 kmem_intr_free(lle->la_opaque, sizeof(struct token_rif)); 443 } 444 #endif 445 446 /* 447 * Parallel to llc_rtrequest. 448 */ 449 void 450 arp_rtrequest(int req, struct rtentry *rt, const struct rt_addrinfo *info) 451 { 452 struct sockaddr *gate = rt->rt_gateway; 453 struct in_ifaddr *ia; 454 struct ifaddr *ifa; 455 struct ifnet *ifp = rt->rt_ifp; 456 int bound; 457 int s; 458 459 if (req == RTM_LLINFO_UPD) { 460 if ((ifa = info->rti_ifa) != NULL) 461 arpannounce1(ifa); 462 return; 463 } 464 465 if ((rt->rt_flags & RTF_GATEWAY) != 0) { 466 if (req != RTM_ADD) 467 return; 468 469 /* 470 * linklayers with particular link MTU limitation. 471 */ 472 switch(ifp->if_type) { 473 #if NFDDI > 0 474 case IFT_FDDI: 475 if (ifp->if_mtu > FDDIIPMTU) 476 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 477 break; 478 #endif 479 #if NARCNET > 0 480 case IFT_ARCNET: 481 { 482 int arcipifmtu; 483 484 if (ifp->if_flags & IFF_LINK0) 485 arcipifmtu = arc_ipmtu; 486 else 487 arcipifmtu = ARCMTU; 488 if (ifp->if_mtu > arcipifmtu) 489 rt->rt_rmx.rmx_mtu = arcipifmtu; 490 break; 491 } 492 #endif 493 } 494 return; 495 } 496 497 switch (req) { 498 case RTM_SETGATE: 499 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 500 break; 501 case RTM_ADD: 502 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 503 if (gate == NULL) { 504 log(LOG_ERR, "%s: arp_setgate failed\n", __func__); 505 break; 506 } 507 if ((rt->rt_flags & RTF_CONNECTED) || 508 (rt->rt_flags & RTF_LOCAL)) { 509 /* 510 * Give this route an expiration time, even though 511 * it's a "permanent" route, so that routes cloned 512 * from it do not need their expiration time set. 513 */ 514 KASSERT(time_uptime != 0); 515 rt->rt_expire = time_uptime; 516 /* 517 * linklayers with particular link MTU limitation. 518 */ 519 switch (ifp->if_type) { 520 #if NFDDI > 0 521 case IFT_FDDI: 522 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 523 (rt->rt_rmx.rmx_mtu > FDDIIPMTU || 524 (rt->rt_rmx.rmx_mtu == 0 && 525 ifp->if_mtu > FDDIIPMTU))) 526 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 527 break; 528 #endif 529 #if NARCNET > 0 530 case IFT_ARCNET: 531 { 532 int arcipifmtu; 533 if (ifp->if_flags & IFF_LINK0) 534 arcipifmtu = arc_ipmtu; 535 else 536 arcipifmtu = ARCMTU; 537 538 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 539 (rt->rt_rmx.rmx_mtu > arcipifmtu || 540 (rt->rt_rmx.rmx_mtu == 0 && 541 ifp->if_mtu > arcipifmtu))) 542 rt->rt_rmx.rmx_mtu = arcipifmtu; 543 break; 544 } 545 #endif 546 } 547 if (rt->rt_flags & RTF_CONNECTED) 548 break; 549 } 550 551 bound = curlwp_bind(); 552 /* Announce a new entry if requested. */ 553 if (rt->rt_flags & RTF_ANNOUNCE) { 554 struct psref psref; 555 ia = in_get_ia_on_iface_psref( 556 satocsin(rt_getkey(rt))->sin_addr, ifp, &psref); 557 if (ia != NULL) { 558 arpannounce(ifp, &ia->ia_ifa, 559 CLLADDR(satocsdl(gate))); 560 ia4_release(ia, &psref); 561 } 562 } 563 564 if (gate->sa_family != AF_LINK || 565 gate->sa_len < sockaddr_dl_measure(0, ifp->if_addrlen)) { 566 log(LOG_DEBUG, "%s: bad gateway value\n", __func__); 567 goto out; 568 } 569 570 satosdl(gate)->sdl_type = ifp->if_type; 571 satosdl(gate)->sdl_index = ifp->if_index; 572 573 /* If the route is for a broadcast address mark it as such. 574 * This way we can avoid an expensive call to in_broadcast() 575 * in ip_output() most of the time (because the route passed 576 * to ip_output() is almost always a host route). */ 577 if (rt->rt_flags & RTF_HOST && 578 !(rt->rt_flags & RTF_BROADCAST) && 579 in_broadcast(satocsin(rt_getkey(rt))->sin_addr, rt->rt_ifp)) 580 rt->rt_flags |= RTF_BROADCAST; 581 /* There is little point in resolving the broadcast address */ 582 if (rt->rt_flags & RTF_BROADCAST) 583 goto out; 584 585 /* 586 * When called from rt_ifa_addlocal, we cannot depend on that 587 * the address (rt_getkey(rt)) exits in the address list of the 588 * interface. So check RTF_LOCAL instead. 589 */ 590 if (rt->rt_flags & RTF_LOCAL) { 591 rt->rt_expire = 0; 592 if (useloopback) { 593 rt->rt_ifp = lo0ifp; 594 rt->rt_rmx.rmx_mtu = 0; 595 } 596 goto out; 597 } 598 599 s = pserialize_read_enter(); 600 ia = in_get_ia_on_iface(satocsin(rt_getkey(rt))->sin_addr, ifp); 601 if (ia == NULL) { 602 pserialize_read_exit(s); 603 goto out; 604 } 605 606 rt->rt_expire = 0; 607 if (useloopback) { 608 rt->rt_ifp = lo0ifp; 609 rt->rt_rmx.rmx_mtu = 0; 610 } 611 rt->rt_flags |= RTF_LOCAL; 612 /* 613 * make sure to set rt->rt_ifa to the interface 614 * address we are using, otherwise we will have trouble 615 * with source address selection. 616 */ 617 ifa = &ia->ia_ifa; 618 if (ifa != rt->rt_ifa) 619 /* Assume it doesn't sleep */ 620 rt_replace_ifa(rt, ifa); 621 pserialize_read_exit(s); 622 out: 623 curlwp_bindx(bound); 624 break; 625 } 626 } 627 628 /* 629 * Broadcast an ARP request. Caller specifies: 630 * - arp header source ip address 631 * - arp header target ip address 632 * - arp header source ethernet address 633 */ 634 static void 635 arprequest(struct ifnet *ifp, 636 const struct in_addr *sip, const struct in_addr *tip, 637 const u_int8_t *enaddr) 638 { 639 struct mbuf *m; 640 struct arphdr *ah; 641 struct sockaddr sa; 642 uint64_t *arps; 643 644 KASSERT(sip != NULL); 645 KASSERT(tip != NULL); 646 KASSERT(enaddr != NULL); 647 648 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 649 return; 650 MCLAIM(m, &arpdomain.dom_mowner); 651 switch (ifp->if_type) { 652 case IFT_IEEE1394: 653 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 654 ifp->if_addrlen; 655 break; 656 default: 657 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 658 2 * ifp->if_addrlen; 659 break; 660 } 661 m->m_pkthdr.len = m->m_len; 662 MH_ALIGN(m, m->m_len); 663 ah = mtod(m, struct arphdr *); 664 memset(ah, 0, m->m_len); 665 switch (ifp->if_type) { 666 case IFT_IEEE1394: /* RFC2734 */ 667 /* fill it now for ar_tpa computation */ 668 ah->ar_hrd = htons(ARPHRD_IEEE1394); 669 break; 670 default: 671 /* ifp->if_output will fill ar_hrd */ 672 break; 673 } 674 ah->ar_pro = htons(ETHERTYPE_IP); 675 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 676 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 677 ah->ar_op = htons(ARPOP_REQUEST); 678 memcpy(ar_sha(ah), enaddr, ah->ar_hln); 679 memcpy(ar_spa(ah), sip, ah->ar_pln); 680 memcpy(ar_tpa(ah), tip, ah->ar_pln); 681 sa.sa_family = AF_ARP; 682 sa.sa_len = 2; 683 m->m_flags |= M_BCAST; 684 arps = ARP_STAT_GETREF(); 685 arps[ARP_STAT_SNDTOTAL]++; 686 arps[ARP_STAT_SENDREQUEST]++; 687 ARP_STAT_PUTREF(); 688 if_output_lock(ifp, ifp, m, &sa, NULL); 689 } 690 691 void 692 arpannounce(struct ifnet *ifp, struct ifaddr *ifa, const uint8_t *enaddr) 693 { 694 struct in_ifaddr *ia = ifatoia(ifa); 695 struct in_addr *ip = &IA_SIN(ifa)->sin_addr; 696 697 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) { 698 arplog(LOG_DEBUG, "%s not ready\n", in_fmtaddr(*ip)); 699 return; 700 } 701 arprequest(ifp, ip, ip, enaddr); 702 } 703 704 static void 705 arpannounce1(struct ifaddr *ifa) 706 { 707 708 arpannounce(ifa->ifa_ifp, ifa, CLLADDR(ifa->ifa_ifp->if_sadl)); 709 } 710 711 /* 712 * Resolve an IP address into an ethernet address. If success, 713 * desten is filled in. If there is no entry in arptab, 714 * set one up and broadcast a request for the IP address. 715 * Hold onto this mbuf and resend it once the address 716 * is finally resolved. A return value of 0 indicates 717 * that desten has been filled in and the packet should be sent 718 * normally; a return value of EWOULDBLOCK indicates that the packet has been 719 * held pending resolution. 720 * Any other value indicates an error. 721 */ 722 int 723 arpresolve(struct ifnet *ifp, const struct rtentry *rt, struct mbuf *m, 724 const struct sockaddr *dst, void *desten, size_t destlen) 725 { 726 struct llentry *la; 727 const char *create_lookup; 728 bool renew; 729 int error; 730 731 KASSERT(m != NULL); 732 733 la = arplookup(ifp, m, NULL, dst, 0); 734 if (la == NULL) 735 goto notfound; 736 737 if ((la->la_flags & LLE_VALID) && 738 ((la->la_flags & LLE_STATIC) || la->la_expire > time_uptime)) { 739 KASSERT(destlen >= ifp->if_addrlen); 740 memcpy(desten, &la->ll_addr, ifp->if_addrlen); 741 LLE_RUNLOCK(la); 742 return 0; 743 } 744 745 notfound: 746 #ifdef IFF_STATICARP /* FreeBSD */ 747 #define _IFF_NOARP (IFF_NOARP | IFF_STATICARP) 748 #else 749 #define _IFF_NOARP IFF_NOARP 750 #endif 751 if (ifp->if_flags & _IFF_NOARP) { 752 if (la != NULL) 753 LLE_RUNLOCK(la); 754 error = ENOTSUP; 755 goto bad; 756 } 757 #undef _IFF_NOARP 758 if (la == NULL) { 759 create_lookup = "create"; 760 IF_AFDATA_WLOCK(ifp); 761 la = lla_create(LLTABLE(ifp), LLE_EXCLUSIVE, dst); 762 IF_AFDATA_WUNLOCK(ifp); 763 if (la == NULL) 764 ARP_STATINC(ARP_STAT_ALLOCFAIL); 765 else 766 arp_init_llentry(ifp, la); 767 } else if (LLE_TRY_UPGRADE(la) == 0) { 768 create_lookup = "lookup"; 769 LLE_RUNLOCK(la); 770 IF_AFDATA_RLOCK(ifp); 771 la = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst); 772 IF_AFDATA_RUNLOCK(ifp); 773 } 774 775 error = EINVAL; 776 if (la == NULL) { 777 log(LOG_DEBUG, 778 "%s: failed to %s llentry for %s on %s\n", 779 __func__, create_lookup, inet_ntoa(satocsin(dst)->sin_addr), 780 ifp->if_xname); 781 goto bad; 782 } 783 784 if ((la->la_flags & LLE_VALID) && 785 ((la->la_flags & LLE_STATIC) || la->la_expire > time_uptime)) 786 { 787 KASSERT(destlen >= ifp->if_addrlen); 788 memcpy(desten, &la->ll_addr, ifp->if_addrlen); 789 renew = false; 790 /* 791 * If entry has an expiry time and it is approaching, 792 * see if we need to send an ARP request within this 793 * arpt_down interval. 794 */ 795 if (!(la->la_flags & LLE_STATIC) && 796 time_uptime + la->la_preempt > la->la_expire) 797 { 798 renew = true; 799 la->la_preempt--; 800 } 801 802 LLE_WUNLOCK(la); 803 804 if (renew) { 805 const u_int8_t *enaddr = 806 #if NCARP > 0 807 (ifp->if_type == IFT_CARP) ? 808 CLLADDR(ifp->if_sadl): 809 #endif 810 CLLADDR(ifp->if_sadl); 811 arprequest(ifp, 812 &satocsin(rt->rt_ifa->ifa_addr)->sin_addr, 813 &satocsin(dst)->sin_addr, enaddr); 814 } 815 816 return 0; 817 } 818 819 if (la->la_flags & LLE_STATIC) { /* should not happen! */ 820 LLE_RUNLOCK(la); 821 log(LOG_DEBUG, "%s: ouch, empty static llinfo for %s\n", 822 __func__, inet_ntoa(satocsin(dst)->sin_addr)); 823 error = EINVAL; 824 goto bad; 825 } 826 827 renew = (la->la_asked == 0 || la->la_expire != time_uptime); 828 829 /* 830 * There is an arptab entry, but no ethernet address 831 * response yet. Add the mbuf to the list, dropping 832 * the oldest packet if we have exceeded the system 833 * setting. 834 */ 835 LLE_WLOCK_ASSERT(la); 836 if (la->la_numheld >= arp_maxhold) { 837 if (la->la_hold != NULL) { 838 struct mbuf *next = la->la_hold->m_nextpkt; 839 m_freem(la->la_hold); 840 la->la_hold = next; 841 la->la_numheld--; 842 ARP_STATINC(ARP_STAT_DFRDROPPED); 843 ARP_STATINC(ARP_STAT_DFRTOTAL); 844 } 845 } 846 if (la->la_hold != NULL) { 847 struct mbuf *curr = la->la_hold; 848 while (curr->m_nextpkt != NULL) 849 curr = curr->m_nextpkt; 850 curr->m_nextpkt = m; 851 } else 852 la->la_hold = m; 853 la->la_numheld++; 854 if (!renew) 855 LLE_DOWNGRADE(la); 856 857 /* 858 * Return EWOULDBLOCK if we have tried less than arp_maxtries. It 859 * will be masked by ether_output(). Return EHOSTDOWN/EHOSTUNREACH 860 * if we have already sent arp_maxtries ARP requests. Retransmit the 861 * ARP request, but not faster than one request per second. 862 */ 863 if (la->la_asked < arp_maxtries) 864 error = EWOULDBLOCK; /* First request. */ 865 else 866 error = (rt != NULL && rt->rt_flags & RTF_GATEWAY) ? 867 EHOSTUNREACH : EHOSTDOWN; 868 869 if (renew) { 870 const u_int8_t *enaddr = 871 #if NCARP > 0 872 (rt != NULL && rt->rt_ifp->if_type == IFT_CARP) ? 873 CLLADDR(rt->rt_ifp->if_sadl): 874 #endif 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(ifp, &satocsin(rt->rt_ifa->ifa_addr)->sin_addr, 883 &satocsin(dst)->sin_addr, enaddr); 884 } else { 885 struct sockaddr_in sin; 886 struct rtentry *_rt; 887 888 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 889 890 /* XXX */ 891 _rt = rtalloc1((struct sockaddr *)&sin, 0); 892 if (_rt == NULL) 893 goto bad; 894 arprequest(ifp, 895 &satocsin(_rt->rt_ifa->ifa_addr)->sin_addr, 896 &satocsin(dst)->sin_addr, enaddr); 897 rt_unref(_rt); 898 } 899 return error; 900 } 901 902 LLE_RUNLOCK(la); 903 return error; 904 905 bad: 906 m_freem(m); 907 return error; 908 } 909 910 /* 911 * Common length and type checks are done here, 912 * then the protocol-specific routine is called. 913 */ 914 void 915 arpintr(void) 916 { 917 struct mbuf *m; 918 struct arphdr *ar; 919 int s; 920 int arplen; 921 922 #ifndef NET_MPSAFE 923 mutex_enter(softnet_lock); 924 KERNEL_LOCK(1, NULL); 925 #endif 926 for (;;) { 927 struct ifnet *rcvif; 928 929 IFQ_LOCK(&arpintrq); 930 IF_DEQUEUE(&arpintrq, m); 931 IFQ_UNLOCK(&arpintrq); 932 if (m == NULL) 933 goto out; 934 if ((m->m_flags & M_PKTHDR) == 0) 935 panic("arpintr"); 936 937 MCLAIM(m, &arpdomain.dom_mowner); 938 ARP_STATINC(ARP_STAT_RCVTOTAL); 939 940 /* 941 * First, make sure we have at least struct arphdr. 942 */ 943 if (m->m_len < sizeof(struct arphdr) || 944 (ar = mtod(m, struct arphdr *)) == NULL) 945 goto badlen; 946 947 rcvif = m_get_rcvif(m, &s); 948 switch (rcvif->if_type) { 949 case IFT_IEEE1394: 950 arplen = sizeof(struct arphdr) + 951 ar->ar_hln + 2 * ar->ar_pln; 952 break; 953 default: 954 arplen = sizeof(struct arphdr) + 955 2 * ar->ar_hln + 2 * ar->ar_pln; 956 break; 957 } 958 m_put_rcvif(rcvif, &s); 959 960 if (/* XXX ntohs(ar->ar_hrd) == ARPHRD_ETHER && */ 961 m->m_len >= arplen) 962 switch (ntohs(ar->ar_pro)) { 963 case ETHERTYPE_IP: 964 case ETHERTYPE_IPTRAILERS: 965 in_arpinput(m); 966 continue; 967 default: 968 ARP_STATINC(ARP_STAT_RCVBADPROTO); 969 } 970 else { 971 badlen: 972 ARP_STATINC(ARP_STAT_RCVBADLEN); 973 } 974 m_freem(m); 975 } 976 out: 977 #ifndef NET_MPSAFE 978 KERNEL_UNLOCK_ONE(NULL); 979 mutex_exit(softnet_lock); 980 #else 981 return; /* XXX gcc */ 982 #endif 983 } 984 985 /* 986 * ARP for Internet protocols on 10 Mb/s Ethernet. 987 * Algorithm is that given in RFC 826. 988 * In addition, a sanity check is performed on the sender 989 * protocol address, to catch impersonators. 990 * We no longer handle negotiations for use of trailer protocol: 991 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent 992 * along with IP replies if we wanted trailers sent to us, 993 * and also sent them in response to IP replies. 994 * This allowed either end to announce the desire to receive 995 * trailer packets. 996 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, 997 * but formerly didn't normally send requests. 998 */ 999 static void 1000 in_arpinput(struct mbuf *m) 1001 { 1002 struct arphdr *ah; 1003 struct ifnet *ifp, *rcvif = NULL; 1004 struct llentry *la = NULL; 1005 struct in_ifaddr *ia = NULL; 1006 #if NBRIDGE > 0 1007 struct in_ifaddr *bridge_ia = NULL; 1008 #endif 1009 #if NCARP > 0 1010 u_int32_t count = 0, index = 0; 1011 #endif 1012 struct sockaddr sa; 1013 struct in_addr isaddr, itaddr, myaddr; 1014 int op; 1015 void *tha; 1016 uint64_t *arps; 1017 struct psref psref, psref_ia; 1018 int s; 1019 1020 if (__predict_false(m_makewritable(&m, 0, m->m_pkthdr.len, M_DONTWAIT))) 1021 goto out; 1022 ah = mtod(m, struct arphdr *); 1023 op = ntohs(ah->ar_op); 1024 1025 rcvif = ifp = m_get_rcvif_psref(m, &psref); 1026 if (__predict_false(rcvif == NULL)) 1027 goto drop; 1028 /* 1029 * Fix up ah->ar_hrd if necessary, before using ar_tha() or 1030 * ar_tpa(). 1031 */ 1032 switch (ifp->if_type) { 1033 case IFT_IEEE1394: 1034 if (ntohs(ah->ar_hrd) == ARPHRD_IEEE1394) 1035 ; 1036 else { 1037 /* XXX this is to make sure we compute ar_tha right */ 1038 /* XXX check ar_hrd more strictly? */ 1039 ah->ar_hrd = htons(ARPHRD_IEEE1394); 1040 } 1041 break; 1042 default: 1043 /* XXX check ar_hrd? */ 1044 break; 1045 } 1046 1047 memcpy(&isaddr, ar_spa(ah), sizeof (isaddr)); 1048 memcpy(&itaddr, ar_tpa(ah), sizeof (itaddr)); 1049 1050 if (m->m_flags & (M_BCAST|M_MCAST)) 1051 ARP_STATINC(ARP_STAT_RCVMCAST); 1052 1053 1054 /* 1055 * Search for a matching interface address 1056 * or any address on the interface to use 1057 * as a dummy address in the rest of this function 1058 */ 1059 s = pserialize_read_enter(); 1060 IN_ADDRHASH_READER_FOREACH(ia, itaddr.s_addr) { 1061 if (!in_hosteq(ia->ia_addr.sin_addr, itaddr)) 1062 continue; 1063 #if NCARP > 0 1064 if (ia->ia_ifp->if_type == IFT_CARP && 1065 ((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) == 1066 (IFF_UP|IFF_RUNNING))) { 1067 index++; 1068 if (ia->ia_ifp == rcvif && 1069 carp_iamatch(ia, ar_sha(ah), 1070 &count, index)) { 1071 break; 1072 } 1073 } else 1074 #endif 1075 if (ia->ia_ifp == rcvif) 1076 break; 1077 #if NBRIDGE > 0 1078 /* 1079 * If the interface we received the packet on 1080 * is part of a bridge, check to see if we need 1081 * to "bridge" the packet to ourselves at this 1082 * layer. Note we still prefer a perfect match, 1083 * but allow this weaker match if necessary. 1084 */ 1085 if (rcvif->if_bridge != NULL && 1086 rcvif->if_bridge == ia->ia_ifp->if_bridge) 1087 bridge_ia = ia; 1088 #endif /* NBRIDGE > 0 */ 1089 } 1090 1091 #if NBRIDGE > 0 1092 if (ia == NULL && bridge_ia != NULL) { 1093 ia = bridge_ia; 1094 m_put_rcvif_psref(rcvif, &psref); 1095 rcvif = NULL; 1096 /* FIXME */ 1097 ifp = bridge_ia->ia_ifp; 1098 } 1099 #endif 1100 if (ia != NULL) 1101 ia4_acquire(ia, &psref_ia); 1102 pserialize_read_exit(s); 1103 1104 if (ia == NULL) { 1105 ia = in_get_ia_on_iface_psref(isaddr, rcvif, &psref_ia); 1106 if (ia == NULL) { 1107 ia = in_get_ia_from_ifp_psref(ifp, &psref_ia); 1108 if (ia == NULL) { 1109 ARP_STATINC(ARP_STAT_RCVNOINT); 1110 goto out; 1111 } 1112 } 1113 } 1114 1115 myaddr = ia->ia_addr.sin_addr; 1116 1117 /* XXX checks for bridge case? */ 1118 if (!memcmp(ar_sha(ah), CLLADDR(ifp->if_sadl), ifp->if_addrlen)) { 1119 ARP_STATINC(ARP_STAT_RCVLOCALSHA); 1120 goto out; /* it's from me, ignore it. */ 1121 } 1122 1123 /* XXX checks for bridge case? */ 1124 if (!memcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 1125 ARP_STATINC(ARP_STAT_RCVBCASTSHA); 1126 log(LOG_ERR, 1127 "%s: arp: link address is broadcast for IP address %s!\n", 1128 ifp->if_xname, in_fmtaddr(isaddr)); 1129 goto out; 1130 } 1131 1132 /* 1133 * If the source IP address is zero, this is an RFC 5227 ARP probe 1134 */ 1135 if (in_nullhost(isaddr)) 1136 ARP_STATINC(ARP_STAT_RCVZEROSPA); 1137 else if (in_hosteq(isaddr, myaddr)) 1138 ARP_STATINC(ARP_STAT_RCVLOCALSPA); 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 ARP_STATINC(ARP_STAT_RCVZEROTPA); 1147 goto out; 1148 } 1149 1150 /* DAD check, RFC 5227 */ 1151 if (in_hosteq(isaddr, myaddr) || 1152 (in_nullhost(isaddr) && in_hosteq(itaddr, myaddr))) 1153 { 1154 arp_dad_duplicated((struct ifaddr *)ia, 1155 lla_snprintf(ar_sha(ah), ah->ar_hln)); 1156 goto out; 1157 } 1158 1159 if (in_nullhost(isaddr)) 1160 goto reply; 1161 1162 if (in_hosteq(itaddr, myaddr)) 1163 la = arpcreate(ifp, m, &isaddr, NULL, 1); 1164 else 1165 la = arplookup(ifp, m, &isaddr, NULL, 1); 1166 if (la == NULL) 1167 goto reply; 1168 1169 if ((la->la_flags & LLE_VALID) && 1170 memcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) { 1171 if (la->la_flags & LLE_STATIC) { 1172 ARP_STATINC(ARP_STAT_RCVOVERPERM); 1173 if (!log_permanent_modify) 1174 goto out; 1175 log(LOG_INFO, 1176 "%s tried to overwrite permanent arp info" 1177 " for %s\n", 1178 lla_snprintf(ar_sha(ah), ah->ar_hln), 1179 in_fmtaddr(isaddr)); 1180 goto out; 1181 } else if (la->lle_tbl->llt_ifp != ifp) { 1182 /* XXX should not happen? */ 1183 ARP_STATINC(ARP_STAT_RCVOVERINT); 1184 if (!log_wrong_iface) 1185 goto out; 1186 log(LOG_INFO, 1187 "%s on %s tried to overwrite " 1188 "arp info for %s on %s\n", 1189 lla_snprintf(ar_sha(ah), ah->ar_hln), 1190 ifp->if_xname, in_fmtaddr(isaddr), 1191 la->lle_tbl->llt_ifp->if_xname); 1192 goto out; 1193 } else { 1194 ARP_STATINC(ARP_STAT_RCVOVER); 1195 if (log_movements) 1196 log(LOG_INFO, "arp info overwritten " 1197 "for %s by %s\n", 1198 in_fmtaddr(isaddr), 1199 lla_snprintf(ar_sha(ah), 1200 ah->ar_hln)); 1201 } 1202 } 1203 1204 /* XXX llentry should have addrlen? */ 1205 #if 0 1206 /* 1207 * sanity check for the address length. 1208 * XXX this does not work for protocols with variable address 1209 * length. -is 1210 */ 1211 if (sdl->sdl_alen && sdl->sdl_alen != ah->ar_hln) { 1212 ARP_STATINC(ARP_STAT_RCVLENCHG); 1213 log(LOG_WARNING, 1214 "arp from %s: new addr len %d, was %d\n", 1215 in_fmtaddr(isaddr), ah->ar_hln, sdl->sdl_alen); 1216 } 1217 #endif 1218 1219 if (ifp->if_addrlen != ah->ar_hln) { 1220 ARP_STATINC(ARP_STAT_RCVBADLEN); 1221 log(LOG_WARNING, 1222 "arp from %s: addr len: new %d, i/f %d (ignored)\n", 1223 in_fmtaddr(isaddr), ah->ar_hln, 1224 ifp->if_addrlen); 1225 goto reply; 1226 } 1227 1228 #if NTOKEN > 0 1229 /* 1230 * XXX uses m_data and assumes the complete answer including 1231 * XXX token-ring headers is in the same buf 1232 */ 1233 if (ifp->if_type == IFT_ISO88025) { 1234 struct token_header *trh; 1235 1236 trh = (struct token_header *)M_TRHSTART(m); 1237 if (trh->token_shost[0] & TOKEN_RI_PRESENT) { 1238 struct token_rif *rif; 1239 size_t riflen; 1240 1241 rif = TOKEN_RIF(trh); 1242 riflen = (ntohs(rif->tr_rcf) & 1243 TOKEN_RCF_LEN_MASK) >> 8; 1244 1245 if (riflen > 2 && 1246 riflen < sizeof(struct token_rif) && 1247 (riflen & 1) == 0) { 1248 rif->tr_rcf ^= htons(TOKEN_RCF_DIRECTION); 1249 rif->tr_rcf &= htons(~TOKEN_RCF_BROADCAST_MASK); 1250 memcpy(TOKEN_RIF_LLE(la), rif, riflen); 1251 } 1252 } 1253 } 1254 #endif /* NTOKEN > 0 */ 1255 1256 KASSERT(sizeof(la->ll_addr) >= ifp->if_addrlen); 1257 (void)memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen); 1258 la->la_flags |= LLE_VALID; 1259 if ((la->la_flags & LLE_STATIC) == 0) { 1260 la->la_expire = time_uptime + arpt_keep; 1261 arp_settimer(la, arpt_keep); 1262 } 1263 la->la_asked = 0; 1264 /* rt->rt_flags &= ~RTF_REJECT; */ 1265 1266 if (la->la_hold != NULL) { 1267 int n = la->la_numheld; 1268 struct mbuf *m_hold, *m_hold_next; 1269 struct sockaddr_in sin; 1270 1271 sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0); 1272 1273 m_hold = la->la_hold; 1274 la->la_hold = NULL; 1275 la->la_numheld = 0; 1276 /* 1277 * We have to unlock here because if_output would call 1278 * arpresolve 1279 */ 1280 LLE_WUNLOCK(la); 1281 ARP_STATADD(ARP_STAT_DFRSENT, n); 1282 ARP_STATADD(ARP_STAT_DFRTOTAL, n); 1283 for (; m_hold != NULL; m_hold = m_hold_next) { 1284 m_hold_next = m_hold->m_nextpkt; 1285 m_hold->m_nextpkt = NULL; 1286 if_output_lock(ifp, ifp, m_hold, sintosa(&sin), NULL); 1287 } 1288 } else 1289 LLE_WUNLOCK(la); 1290 la = NULL; 1291 1292 reply: 1293 if (la != NULL) { 1294 LLE_WUNLOCK(la); 1295 la = NULL; 1296 } 1297 if (op != ARPOP_REQUEST) { 1298 if (op == ARPOP_REPLY) 1299 ARP_STATINC(ARP_STAT_RCVREPLY); 1300 goto out; 1301 } 1302 ARP_STATINC(ARP_STAT_RCVREQUEST); 1303 if (in_hosteq(itaddr, myaddr)) { 1304 /* If our address is unuseable, don't reply */ 1305 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) 1306 goto out; 1307 /* I am the target */ 1308 tha = ar_tha(ah); 1309 if (tha) 1310 memcpy(tha, ar_sha(ah), ah->ar_hln); 1311 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1312 } else { 1313 /* Proxy ARP */ 1314 struct llentry *lle = NULL; 1315 struct sockaddr_in sin; 1316 #if NCARP > 0 1317 struct ifnet *_rcvif = m_get_rcvif(m, &s); 1318 if (ifp->if_type == IFT_CARP && _rcvif->if_type != IFT_CARP) 1319 goto out; 1320 m_put_rcvif(_rcvif, &s); 1321 #endif 1322 1323 tha = ar_tha(ah); 1324 1325 sockaddr_in_init(&sin, &itaddr, 0); 1326 1327 IF_AFDATA_RLOCK(ifp); 1328 lle = lla_lookup(LLTABLE(ifp), 0, (struct sockaddr *)&sin); 1329 IF_AFDATA_RUNLOCK(ifp); 1330 1331 if ((lle != NULL) && (lle->la_flags & LLE_PUB)) { 1332 (void)memcpy(tha, ar_sha(ah), ah->ar_hln); 1333 (void)memcpy(ar_sha(ah), &lle->ll_addr, ah->ar_hln); 1334 LLE_RUNLOCK(lle); 1335 } else { 1336 if (lle != NULL) 1337 LLE_RUNLOCK(lle); 1338 goto drop; 1339 } 1340 } 1341 ia4_release(ia, &psref_ia); 1342 1343 memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); 1344 memcpy(ar_spa(ah), &itaddr, ah->ar_pln); 1345 ah->ar_op = htons(ARPOP_REPLY); 1346 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 1347 switch (ifp->if_type) { 1348 case IFT_IEEE1394: 1349 /* 1350 * ieee1394 arp reply is broadcast 1351 */ 1352 m->m_flags &= ~M_MCAST; 1353 m->m_flags |= M_BCAST; 1354 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + ah->ar_hln; 1355 break; 1356 default: 1357 m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */ 1358 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); 1359 break; 1360 } 1361 m->m_pkthdr.len = m->m_len; 1362 sa.sa_family = AF_ARP; 1363 sa.sa_len = 2; 1364 arps = ARP_STAT_GETREF(); 1365 arps[ARP_STAT_SNDTOTAL]++; 1366 arps[ARP_STAT_SNDREPLY]++; 1367 ARP_STAT_PUTREF(); 1368 if_output_lock(ifp, ifp, m, &sa, NULL); 1369 if (rcvif != NULL) 1370 m_put_rcvif_psref(rcvif, &psref); 1371 return; 1372 1373 out: 1374 if (la != NULL) 1375 LLE_WUNLOCK(la); 1376 drop: 1377 if (ia != NULL) 1378 ia4_release(ia, &psref_ia); 1379 if (rcvif != NULL) 1380 m_put_rcvif_psref(rcvif, &psref); 1381 m_freem(m); 1382 } 1383 1384 /* 1385 * Lookup or a new address in arptab. 1386 */ 1387 static struct llentry * 1388 arplookup(struct ifnet *ifp, struct mbuf *m, const struct in_addr *addr, 1389 const struct sockaddr *sa, int wlock) 1390 { 1391 struct sockaddr_in sin; 1392 struct llentry *la; 1393 int flags = wlock ? LLE_EXCLUSIVE : 0; 1394 1395 1396 if (sa == NULL) { 1397 KASSERT(addr != NULL); 1398 sockaddr_in_init(&sin, addr, 0); 1399 sa = sintocsa(&sin); 1400 } 1401 1402 IF_AFDATA_RLOCK(ifp); 1403 la = lla_lookup(LLTABLE(ifp), flags, sa); 1404 IF_AFDATA_RUNLOCK(ifp); 1405 1406 return la; 1407 } 1408 1409 static struct llentry * 1410 arpcreate(struct ifnet *ifp, struct mbuf *m, const struct in_addr *addr, 1411 const struct sockaddr *sa, int wlock) 1412 { 1413 struct sockaddr_in sin; 1414 struct llentry *la; 1415 int flags = wlock ? LLE_EXCLUSIVE : 0; 1416 1417 if (sa == NULL) { 1418 KASSERT(addr != NULL); 1419 sockaddr_in_init(&sin, addr, 0); 1420 sa = sintocsa(&sin); 1421 } 1422 1423 la = arplookup(ifp, m, addr, sa, wlock); 1424 1425 if (la == NULL) { 1426 IF_AFDATA_WLOCK(ifp); 1427 la = lla_create(LLTABLE(ifp), flags, sa); 1428 IF_AFDATA_WUNLOCK(ifp); 1429 1430 if (la != NULL) 1431 arp_init_llentry(ifp, la); 1432 } 1433 1434 return la; 1435 } 1436 1437 int 1438 arpioctl(u_long cmd, void *data) 1439 { 1440 1441 return EOPNOTSUPP; 1442 } 1443 1444 void 1445 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1446 { 1447 struct in_addr *ip; 1448 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1449 1450 /* 1451 * Warn the user if another station has this IP address, 1452 * but only if the interface IP address is not zero. 1453 */ 1454 ip = &IA_SIN(ifa)->sin_addr; 1455 if (!in_nullhost(*ip) && 1456 (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) == 0) { 1457 struct llentry *lle; 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 (in_nullhost(*ip)) { 1482 if (ia->ia_dad_stop != NULL) /* safety */ 1483 ia->ia_dad_stop(ifa); 1484 ia->ia_dad_start = NULL; 1485 ia->ia_dad_stop = NULL; 1486 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1487 } else { 1488 ia->ia_dad_start = arp_dad_start; 1489 ia->ia_dad_stop = arp_dad_stop; 1490 if (ia->ia4_flags & IN_IFF_TRYTENTATIVE) 1491 ia->ia4_flags |= IN_IFF_TENTATIVE; 1492 else 1493 arpannounce1(ifa); 1494 } 1495 } 1496 1497 TAILQ_HEAD(dadq_head, dadq); 1498 struct dadq { 1499 TAILQ_ENTRY(dadq) dad_list; 1500 struct ifaddr *dad_ifa; 1501 int dad_count; /* max ARP to send */ 1502 int dad_arp_tcount; /* # of trials to send ARP */ 1503 int dad_arp_ocount; /* ARP sent so far */ 1504 int dad_arp_announce; /* max ARP announcements */ 1505 int dad_arp_acount; /* # of announcements */ 1506 struct callout dad_timer_ch; 1507 }; 1508 MALLOC_JUSTDEFINE(M_IPARP, "ARP DAD", "ARP DAD Structure"); 1509 1510 static struct dadq_head dadq; 1511 static int dad_init = 0; 1512 static int dad_maxtry = 15; /* max # of *tries* to transmit DAD packet */ 1513 static kmutex_t arp_dad_lock; 1514 1515 static struct dadq * 1516 arp_dad_find(struct ifaddr *ifa) 1517 { 1518 struct dadq *dp; 1519 1520 KASSERT(mutex_owned(&arp_dad_lock)); 1521 1522 TAILQ_FOREACH(dp, &dadq, dad_list) { 1523 if (dp->dad_ifa == ifa) 1524 return dp; 1525 } 1526 return NULL; 1527 } 1528 1529 static void 1530 arp_dad_starttimer(struct dadq *dp, int ticks) 1531 { 1532 1533 callout_reset(&dp->dad_timer_ch, ticks, 1534 (void (*)(void *))arp_dad_timer, (void *)dp->dad_ifa); 1535 } 1536 1537 static void 1538 arp_dad_stoptimer(struct dadq *dp) 1539 { 1540 1541 #ifdef NET_MPSAFE 1542 callout_halt(&dp->dad_timer_ch, NULL); 1543 #else 1544 callout_halt(&dp->dad_timer_ch, softnet_lock); 1545 #endif 1546 } 1547 1548 static void 1549 arp_dad_output(struct dadq *dp, struct ifaddr *ifa) 1550 { 1551 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1552 struct ifnet *ifp = ifa->ifa_ifp; 1553 struct in_addr sip; 1554 1555 dp->dad_arp_tcount++; 1556 if ((ifp->if_flags & IFF_UP) == 0) 1557 return; 1558 if ((ifp->if_flags & IFF_RUNNING) == 0) 1559 return; 1560 1561 dp->dad_arp_tcount = 0; 1562 dp->dad_arp_ocount++; 1563 1564 memset(&sip, 0, sizeof(sip)); 1565 arprequest(ifa->ifa_ifp, &sip, &ia->ia_addr.sin_addr, 1566 CLLADDR(ifa->ifa_ifp->if_sadl)); 1567 } 1568 1569 /* 1570 * Start Duplicate Address Detection (DAD) for specified interface address. 1571 */ 1572 static void 1573 arp_dad_start(struct ifaddr *ifa) 1574 { 1575 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1576 struct dadq *dp; 1577 1578 if (!dad_init) { 1579 TAILQ_INIT(&dadq); 1580 mutex_init(&arp_dad_lock, MUTEX_DEFAULT, IPL_NONE); 1581 dad_init++; 1582 } 1583 1584 /* 1585 * If we don't need DAD, don't do it. 1586 * - DAD is disabled (ip_dad_count == 0) 1587 */ 1588 if (!(ia->ia4_flags & IN_IFF_TENTATIVE)) { 1589 log(LOG_DEBUG, 1590 "%s: called with non-tentative address %s(%s)\n", __func__, 1591 in_fmtaddr(ia->ia_addr.sin_addr), 1592 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1593 return; 1594 } 1595 if (!ip_dad_count) { 1596 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1597 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1598 arpannounce1(ifa); 1599 return; 1600 } 1601 KASSERT(ifa->ifa_ifp != NULL); 1602 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) 1603 return; 1604 1605 mutex_enter(&arp_dad_lock); 1606 if (arp_dad_find(ifa) != NULL) { 1607 mutex_exit(&arp_dad_lock); 1608 /* DAD already in progress */ 1609 return; 1610 } 1611 1612 dp = malloc(sizeof(*dp), M_IPARP, M_NOWAIT); 1613 if (dp == NULL) { 1614 mutex_exit(&arp_dad_lock); 1615 log(LOG_ERR, "%s: memory allocation failed for %s(%s)\n", 1616 __func__, in_fmtaddr(ia->ia_addr.sin_addr), 1617 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1618 return; 1619 } 1620 memset(dp, 0, sizeof(*dp)); 1621 callout_init(&dp->dad_timer_ch, CALLOUT_MPSAFE); 1622 1623 /* 1624 * Send ARP packet for DAD, ip_dad_count times. 1625 * Note that we must delay the first transmission. 1626 */ 1627 dp->dad_ifa = ifa; 1628 ifaref(ifa); /* just for safety */ 1629 dp->dad_count = ip_dad_count; 1630 dp->dad_arp_announce = 0; /* Will be set when starting to announce */ 1631 dp->dad_arp_acount = dp->dad_arp_ocount = dp->dad_arp_tcount = 0; 1632 TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list); 1633 1634 arplog(LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1635 in_fmtaddr(ia->ia_addr.sin_addr)); 1636 1637 arp_dad_starttimer(dp, cprng_fast32() % (PROBE_WAIT * hz)); 1638 1639 mutex_exit(&arp_dad_lock); 1640 } 1641 1642 /* 1643 * terminate DAD unconditionally. used for address removals. 1644 */ 1645 static void 1646 arp_dad_stop(struct ifaddr *ifa) 1647 { 1648 struct dadq *dp; 1649 1650 if (!dad_init) 1651 return; 1652 1653 mutex_enter(&arp_dad_lock); 1654 dp = arp_dad_find(ifa); 1655 if (dp == NULL) { 1656 mutex_exit(&arp_dad_lock); 1657 /* DAD wasn't started yet */ 1658 return; 1659 } 1660 1661 /* Prevent the timer from running anymore. */ 1662 TAILQ_REMOVE(&dadq, dp, dad_list); 1663 mutex_exit(&arp_dad_lock); 1664 1665 arp_dad_stoptimer(dp); 1666 1667 free(dp, M_IPARP); 1668 dp = NULL; 1669 ifafree(ifa); 1670 } 1671 1672 static void 1673 arp_dad_timer(struct ifaddr *ifa) 1674 { 1675 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1676 struct dadq *dp; 1677 1678 mutex_enter(softnet_lock); 1679 KERNEL_LOCK(1, NULL); 1680 mutex_enter(&arp_dad_lock); 1681 1682 /* Sanity check */ 1683 if (ia == NULL) { 1684 log(LOG_ERR, "%s: called with null parameter\n", __func__); 1685 goto done; 1686 } 1687 dp = arp_dad_find(ifa); 1688 if (dp == NULL) { 1689 /* DAD seems to be stopping, so do nothing. */ 1690 goto done; 1691 } 1692 if (ia->ia4_flags & IN_IFF_DUPLICATED) { 1693 log(LOG_ERR, "%s: called with duplicate address %s(%s)\n", 1694 __func__, in_fmtaddr(ia->ia_addr.sin_addr), 1695 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1696 goto done; 1697 } 1698 if ((ia->ia4_flags & IN_IFF_TENTATIVE) == 0 && dp->dad_arp_acount == 0) 1699 { 1700 log(LOG_ERR, "%s: called with non-tentative address %s(%s)\n", 1701 __func__, in_fmtaddr(ia->ia_addr.sin_addr), 1702 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1703 goto done; 1704 } 1705 1706 /* timeouted with IFF_{RUNNING,UP} check */ 1707 if (dp->dad_arp_tcount > dad_maxtry) { 1708 arplog(LOG_INFO, "%s: could not run DAD, driver problem?\n", 1709 if_name(ifa->ifa_ifp)); 1710 1711 TAILQ_REMOVE(&dadq, dp, dad_list); 1712 free(dp, M_IPARP); 1713 dp = NULL; 1714 ifafree(ifa); 1715 goto done; 1716 } 1717 1718 /* Need more checks? */ 1719 if (dp->dad_arp_ocount < dp->dad_count) { 1720 int adelay; 1721 1722 /* 1723 * We have more ARP to go. Send ARP packet for DAD. 1724 */ 1725 arp_dad_output(dp, ifa); 1726 if (dp->dad_arp_ocount < dp->dad_count) 1727 adelay = (PROBE_MIN * hz) + 1728 (cprng_fast32() % 1729 ((PROBE_MAX * hz) - (PROBE_MIN * hz))); 1730 else 1731 adelay = ANNOUNCE_WAIT * hz; 1732 arp_dad_starttimer(dp, adelay); 1733 goto done; 1734 } else if (dp->dad_arp_acount == 0) { 1735 /* 1736 * We are done with DAD. 1737 * No duplicate address found. 1738 */ 1739 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1740 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1741 arplog(LOG_DEBUG, 1742 "%s: DAD complete for %s - no duplicates found\n", 1743 if_name(ifa->ifa_ifp), 1744 in_fmtaddr(ia->ia_addr.sin_addr)); 1745 dp->dad_arp_announce = ANNOUNCE_NUM; 1746 goto announce; 1747 } else if (dp->dad_arp_acount < dp->dad_arp_announce) { 1748 announce: 1749 /* 1750 * Announce the address. 1751 */ 1752 arpannounce1(ifa); 1753 dp->dad_arp_acount++; 1754 if (dp->dad_arp_acount < dp->dad_arp_announce) { 1755 arp_dad_starttimer(dp, ANNOUNCE_INTERVAL * hz); 1756 goto done; 1757 } 1758 arplog(LOG_DEBUG, 1759 "%s: ARP announcement complete for %s\n", 1760 if_name(ifa->ifa_ifp), 1761 in_fmtaddr(ia->ia_addr.sin_addr)); 1762 } 1763 1764 TAILQ_REMOVE(&dadq, dp, dad_list); 1765 free(dp, M_IPARP); 1766 dp = NULL; 1767 ifafree(ifa); 1768 1769 done: 1770 mutex_exit(&arp_dad_lock); 1771 KERNEL_UNLOCK_ONE(NULL); 1772 mutex_exit(softnet_lock); 1773 } 1774 1775 static void 1776 arp_dad_duplicated(struct ifaddr *ifa, const char *sha) 1777 { 1778 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1779 struct ifnet *ifp = ifa->ifa_ifp; 1780 const char *iastr = in_fmtaddr(ia->ia_addr.sin_addr); 1781 1782 if (ia->ia4_flags & (IN_IFF_TENTATIVE|IN_IFF_DUPLICATED)) { 1783 log(LOG_ERR, 1784 "%s: DAD duplicate address %s from %s\n", 1785 if_name(ifp), iastr, sha); 1786 } else if (ia->ia_dad_defended == 0 || 1787 ia->ia_dad_defended < time_uptime - DEFEND_INTERVAL) { 1788 ia->ia_dad_defended = time_uptime; 1789 arpannounce1(ifa); 1790 log(LOG_ERR, 1791 "%s: DAD defended address %s from %s\n", 1792 if_name(ifp), iastr, sha); 1793 return; 1794 } else { 1795 /* If DAD is disabled, just report the duplicate. */ 1796 if (ip_dad_count == 0) { 1797 log(LOG_ERR, 1798 "%s: DAD ignoring duplicate address %s from %s\n", 1799 if_name(ifp), iastr, sha); 1800 return; 1801 } 1802 log(LOG_ERR, 1803 "%s: DAD defence failed for %s from %s\n", 1804 if_name(ifp), iastr, sha); 1805 } 1806 1807 arp_dad_stop(ifa); 1808 1809 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1810 if ((ia->ia4_flags & IN_IFF_DUPLICATED) == 0) { 1811 ia->ia4_flags |= IN_IFF_DUPLICATED; 1812 /* Inform the routing socket of the duplicate address */ 1813 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1814 } 1815 } 1816 1817 /* 1818 * Called from 10 Mb/s Ethernet interrupt handlers 1819 * when ether packet type ETHERTYPE_REVARP 1820 * is received. Common length and type checks are done here, 1821 * then the protocol-specific routine is called. 1822 */ 1823 void 1824 revarpinput(struct mbuf *m) 1825 { 1826 struct arphdr *ar; 1827 1828 if (m->m_len < sizeof(struct arphdr)) 1829 goto out; 1830 ar = mtod(m, struct arphdr *); 1831 #if 0 /* XXX I don't think we need this... and it will prevent other LL */ 1832 if (ntohs(ar->ar_hrd) != ARPHRD_ETHER) 1833 goto out; 1834 #endif 1835 if (m->m_len < sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln)) 1836 goto out; 1837 switch (ntohs(ar->ar_pro)) { 1838 case ETHERTYPE_IP: 1839 case ETHERTYPE_IPTRAILERS: 1840 in_revarpinput(m); 1841 return; 1842 1843 default: 1844 break; 1845 } 1846 out: 1847 m_freem(m); 1848 } 1849 1850 /* 1851 * RARP for Internet protocols on 10 Mb/s Ethernet. 1852 * Algorithm is that given in RFC 903. 1853 * We are only using for bootstrap purposes to get an ip address for one of 1854 * our interfaces. Thus we support no user-interface. 1855 * 1856 * Since the contents of the RARP reply are specific to the interface that 1857 * sent the request, this code must ensure that they are properly associated. 1858 * 1859 * Note: also supports ARP via RARP packets, per the RFC. 1860 */ 1861 void 1862 in_revarpinput(struct mbuf *m) 1863 { 1864 struct arphdr *ah; 1865 void *tha; 1866 int op; 1867 struct ifnet *rcvif; 1868 int s; 1869 1870 ah = mtod(m, struct arphdr *); 1871 op = ntohs(ah->ar_op); 1872 1873 rcvif = m_get_rcvif(m, &s); 1874 switch (rcvif->if_type) { 1875 case IFT_IEEE1394: 1876 /* ARP without target hardware address is not supported */ 1877 goto out; 1878 default: 1879 break; 1880 } 1881 1882 switch (op) { 1883 case ARPOP_REQUEST: 1884 case ARPOP_REPLY: /* per RFC */ 1885 m_put_rcvif(rcvif, &s); 1886 in_arpinput(m); 1887 return; 1888 case ARPOP_REVREPLY: 1889 break; 1890 case ARPOP_REVREQUEST: /* handled by rarpd(8) */ 1891 default: 1892 goto out; 1893 } 1894 if (!revarp_in_progress) 1895 goto out; 1896 if (rcvif != myip_ifp) /* !same interface */ 1897 goto out; 1898 if (myip_initialized) 1899 goto wake; 1900 tha = ar_tha(ah); 1901 if (tha == NULL) 1902 goto out; 1903 if (memcmp(tha, CLLADDR(rcvif->if_sadl), rcvif->if_sadl->sdl_alen)) 1904 goto out; 1905 memcpy(&srv_ip, ar_spa(ah), sizeof(srv_ip)); 1906 memcpy(&myip, ar_tpa(ah), sizeof(myip)); 1907 myip_initialized = 1; 1908 wake: /* Do wakeup every time in case it was missed. */ 1909 wakeup((void *)&myip); 1910 1911 out: 1912 m_put_rcvif(rcvif, &s); 1913 m_freem(m); 1914 } 1915 1916 /* 1917 * Send a RARP request for the ip address of the specified interface. 1918 * The request should be RFC 903-compliant. 1919 */ 1920 static void 1921 revarprequest(struct ifnet *ifp) 1922 { 1923 struct sockaddr sa; 1924 struct mbuf *m; 1925 struct arphdr *ah; 1926 void *tha; 1927 1928 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 1929 return; 1930 MCLAIM(m, &arpdomain.dom_mowner); 1931 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) + 1932 2*ifp->if_addrlen; 1933 m->m_pkthdr.len = m->m_len; 1934 MH_ALIGN(m, m->m_len); 1935 ah = mtod(m, struct arphdr *); 1936 memset(ah, 0, m->m_len); 1937 ah->ar_pro = htons(ETHERTYPE_IP); 1938 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 1939 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 1940 ah->ar_op = htons(ARPOP_REVREQUEST); 1941 1942 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1943 tha = ar_tha(ah); 1944 if (tha == NULL) { 1945 m_free(m); 1946 return; 1947 } 1948 memcpy(tha, CLLADDR(ifp->if_sadl), ah->ar_hln); 1949 1950 sa.sa_family = AF_ARP; 1951 sa.sa_len = 2; 1952 m->m_flags |= M_BCAST; 1953 1954 if_output_lock(ifp, ifp, m, &sa, NULL); 1955 } 1956 1957 /* 1958 * RARP for the ip address of the specified interface, but also 1959 * save the ip address of the server that sent the answer. 1960 * Timeout if no response is received. 1961 */ 1962 int 1963 revarpwhoarewe(struct ifnet *ifp, struct in_addr *serv_in, 1964 struct in_addr *clnt_in) 1965 { 1966 int result, count = 20; 1967 1968 myip_initialized = 0; 1969 myip_ifp = ifp; 1970 1971 revarp_in_progress = 1; 1972 while (count--) { 1973 revarprequest(ifp); 1974 result = tsleep((void *)&myip, PSOCK, "revarp", hz/2); 1975 if (result != EWOULDBLOCK) 1976 break; 1977 } 1978 revarp_in_progress = 0; 1979 1980 if (!myip_initialized) 1981 return ENETUNREACH; 1982 1983 memcpy(serv_in, &srv_ip, sizeof(*serv_in)); 1984 memcpy(clnt_in, &myip, sizeof(*clnt_in)); 1985 return 0; 1986 } 1987 1988 void 1989 arp_stat_add(int type, uint64_t count) 1990 { 1991 ARP_STATADD(type, count); 1992 } 1993 1994 static int 1995 sysctl_net_inet_arp_stats(SYSCTLFN_ARGS) 1996 { 1997 1998 return NETSTAT_SYSCTL(arpstat_percpu, ARP_NSTATS); 1999 } 2000 2001 static void 2002 sysctl_net_inet_arp_setup(struct sysctllog **clog) 2003 { 2004 const struct sysctlnode *node; 2005 2006 sysctl_createv(clog, 0, NULL, NULL, 2007 CTLFLAG_PERMANENT, 2008 CTLTYPE_NODE, "inet", NULL, 2009 NULL, 0, NULL, 0, 2010 CTL_NET, PF_INET, CTL_EOL); 2011 sysctl_createv(clog, 0, NULL, &node, 2012 CTLFLAG_PERMANENT, 2013 CTLTYPE_NODE, "arp", 2014 SYSCTL_DESCR("Address Resolution Protocol"), 2015 NULL, 0, NULL, 0, 2016 CTL_NET, PF_INET, CTL_CREATE, CTL_EOL); 2017 2018 sysctl_createv(clog, 0, NULL, NULL, 2019 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2020 CTLTYPE_INT, "keep", 2021 SYSCTL_DESCR("Valid ARP entry lifetime in seconds"), 2022 NULL, 0, &arpt_keep, 0, 2023 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2024 2025 sysctl_createv(clog, 0, NULL, NULL, 2026 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2027 CTLTYPE_INT, "down", 2028 SYSCTL_DESCR("Failed ARP entry lifetime in seconds"), 2029 NULL, 0, &arpt_down, 0, 2030 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2031 2032 sysctl_createv(clog, 0, NULL, NULL, 2033 CTLFLAG_PERMANENT, 2034 CTLTYPE_STRUCT, "stats", 2035 SYSCTL_DESCR("ARP statistics"), 2036 sysctl_net_inet_arp_stats, 0, NULL, 0, 2037 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2038 2039 sysctl_createv(clog, 0, NULL, NULL, 2040 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2041 CTLTYPE_INT, "log_movements", 2042 SYSCTL_DESCR("log ARP replies from MACs different than" 2043 " the one in the cache"), 2044 NULL, 0, &log_movements, 0, 2045 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2046 2047 sysctl_createv(clog, 0, NULL, NULL, 2048 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2049 CTLTYPE_INT, "log_permanent_modify", 2050 SYSCTL_DESCR("log ARP replies from MACs different than" 2051 " the one in the permanent arp entry"), 2052 NULL, 0, &log_permanent_modify, 0, 2053 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2054 2055 sysctl_createv(clog, 0, NULL, NULL, 2056 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2057 CTLTYPE_INT, "log_wrong_iface", 2058 SYSCTL_DESCR("log ARP packets arriving on the wrong" 2059 " interface"), 2060 NULL, 0, &log_wrong_iface, 0, 2061 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2062 2063 sysctl_createv(clog, 0, NULL, NULL, 2064 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2065 CTLTYPE_INT, "log_unknown_network", 2066 SYSCTL_DESCR("log ARP packets from non-local network"), 2067 NULL, 0, &log_unknown_network, 0, 2068 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2069 2070 sysctl_createv(clog, 0, NULL, NULL, 2071 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2072 CTLTYPE_INT, "debug", 2073 SYSCTL_DESCR("Enable ARP DAD debug output"), 2074 NULL, 0, &arp_debug, 0, 2075 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2076 } 2077 2078 #endif /* INET */ 2079