1 /* $NetBSD: if_arp.c,v 1.191 2015/10/20 07:46:59 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 1.191 2015/10/20 07:46:59 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 arptfree(struct rtentry *); 163 static void arptimer(void *); 164 static struct llentry *arplookup(struct ifnet *, struct mbuf *, 165 const struct in_addr *, int, int, int, struct rtentry *); 166 static void in_arpinput(struct mbuf *); 167 static void in_revarpinput(struct mbuf *); 168 static void revarprequest(struct ifnet *); 169 170 static void arp_drainstub(void); 171 172 static void arp_dad_timer(struct ifaddr *); 173 static void arp_dad_start(struct ifaddr *); 174 static void arp_dad_stop(struct ifaddr *); 175 static void arp_dad_duplicated(struct ifaddr *); 176 177 struct ifqueue arpintrq = { 178 .ifq_head = NULL, 179 .ifq_tail = NULL, 180 .ifq_len = 0, 181 .ifq_maxlen = 50, 182 .ifq_drops = 0, 183 }; 184 static int arp_inuse, arp_allocated; 185 static int arp_maxtries = 5; 186 static int useloopback = 1; /* use loopback interface for local traffic */ 187 188 static percpu_t *arpstat_percpu; 189 190 #define ARP_STAT_GETREF() _NET_STAT_GETREF(arpstat_percpu) 191 #define ARP_STAT_PUTREF() _NET_STAT_PUTREF(arpstat_percpu) 192 193 #define ARP_STATINC(x) _NET_STATINC(arpstat_percpu, x) 194 #define ARP_STATADD(x, v) _NET_STATADD(arpstat_percpu, x, v) 195 196 /* revarp state */ 197 static struct in_addr myip, srv_ip; 198 static int myip_initialized = 0; 199 static int revarp_in_progress = 0; 200 static struct ifnet *myip_ifp = NULL; 201 202 #ifdef DDB 203 static void db_print_sa(const struct sockaddr *); 204 static void db_print_ifa(struct ifaddr *); 205 static void db_print_llinfo(void *); 206 static int db_show_rtentry(struct rtentry *, void *); 207 #endif 208 209 static int arp_drainwanted; 210 211 static int log_movements = 1; 212 static int log_permanent_modify = 1; 213 static int log_wrong_iface = 1; 214 static int log_unknown_network = 1; 215 216 /* 217 * this should be elsewhere. 218 */ 219 220 static char * 221 lla_snprintf(u_int8_t *, int); 222 223 static char * 224 lla_snprintf(u_int8_t *adrp, int len) 225 { 226 #define NUMBUFS 3 227 static char buf[NUMBUFS][16*3]; 228 static int bnum = 0; 229 230 int i; 231 char *p; 232 233 p = buf[bnum]; 234 235 *p++ = hexdigits[(*adrp)>>4]; 236 *p++ = hexdigits[(*adrp++)&0xf]; 237 238 for (i=1; i<len && i<16; i++) { 239 *p++ = ':'; 240 *p++ = hexdigits[(*adrp)>>4]; 241 *p++ = hexdigits[(*adrp++)&0xf]; 242 } 243 244 *p = 0; 245 p = buf[bnum]; 246 bnum = (bnum + 1) % NUMBUFS; 247 return p; 248 } 249 250 DOMAIN_DEFINE(arpdomain); /* forward declare and add to link set */ 251 252 static void 253 arp_fasttimo(void) 254 { 255 if (arp_drainwanted) { 256 arp_drain(); 257 arp_drainwanted = 0; 258 } 259 } 260 261 const struct protosw arpsw[] = { 262 { .pr_type = 0, 263 .pr_domain = &arpdomain, 264 .pr_protocol = 0, 265 .pr_flags = 0, 266 .pr_input = 0, 267 .pr_output = 0, 268 .pr_ctlinput = 0, 269 .pr_ctloutput = 0, 270 .pr_usrreqs = 0, 271 .pr_init = arp_init, 272 .pr_fasttimo = arp_fasttimo, 273 .pr_slowtimo = 0, 274 .pr_drain = arp_drainstub, 275 } 276 }; 277 278 struct domain arpdomain = { 279 .dom_family = PF_ARP, 280 .dom_name = "arp", 281 .dom_protosw = arpsw, 282 .dom_protoswNPROTOSW = &arpsw[__arraycount(arpsw)], 283 }; 284 285 static void sysctl_net_inet_arp_setup(struct sysctllog **); 286 287 void 288 arp_init(void) 289 { 290 291 sysctl_net_inet_arp_setup(NULL); 292 arpstat_percpu = percpu_alloc(sizeof(uint64_t) * ARP_NSTATS); 293 } 294 295 static void 296 arp_drainstub(void) 297 { 298 arp_drainwanted = 1; 299 } 300 301 /* 302 * ARP protocol drain routine. Called when memory is in short supply. 303 * Called at splvm(); don't acquire softnet_lock as can be called from 304 * hardware interrupt handlers. 305 */ 306 void 307 arp_drain(void) 308 { 309 310 lltable_drain(AF_INET); 311 } 312 313 static void 314 arptimer(void *arg) 315 { 316 struct llentry *lle = arg; 317 struct ifnet *ifp; 318 struct rtentry *rt; 319 320 if (lle == NULL) 321 return; 322 323 if (lle->la_flags & LLE_STATIC) 324 return; 325 326 LLE_WLOCK(lle); 327 if (callout_pending(&lle->la_timer)) { 328 /* 329 * Here we are a bit odd here in the treatment of 330 * active/pending. If the pending bit is set, it got 331 * rescheduled before I ran. The active 332 * bit we ignore, since if it was stopped 333 * in ll_tablefree() and was currently running 334 * it would have return 0 so the code would 335 * not have deleted it since the callout could 336 * not be stopped so we want to go through 337 * with the delete here now. If the callout 338 * was restarted, the pending bit will be back on and 339 * we just want to bail since the callout_reset would 340 * return 1 and our reference would have been removed 341 * by arpresolve() below. 342 */ 343 LLE_WUNLOCK(lle); 344 return; 345 } 346 ifp = lle->lle_tbl->llt_ifp; 347 rt = lle->la_rt; 348 lle->la_rt = NULL; 349 350 callout_stop(&lle->la_timer); 351 352 /* XXX: LOR avoidance. We still have ref on lle. */ 353 LLE_WUNLOCK(lle); 354 355 if (rt != NULL) { 356 /* We have to call arptfree w/o IF_AFDATA_LOCK */ 357 arptfree(rt); 358 } 359 360 IF_AFDATA_LOCK(ifp); 361 LLE_WLOCK(lle); 362 363 /* Guard against race with other llentry_free(). */ 364 if (lle->la_flags & LLE_LINKED) { 365 size_t pkts_dropped; 366 367 LLE_REMREF(lle); 368 pkts_dropped = llentry_free(lle); 369 ARP_STATADD(ARP_STAT_DFRDROPPED, pkts_dropped); 370 } else { 371 LLE_FREE_LOCKED(lle); 372 } 373 374 IF_AFDATA_UNLOCK(ifp); 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_CLONING; 398 if (rt->rt_flags & RTF_CLONING || 399 ((rt->rt_flags & (RTF_LLINFO | RTF_LOCAL)) && !rt->rt_llinfo)) 400 { 401 union { 402 struct sockaddr sa; 403 struct sockaddr_storage ss; 404 struct sockaddr_dl sdl; 405 } u; 406 /* 407 * Case 1: This route should come from a route to iface. 408 */ 409 sockaddr_dl_init(&u.sdl, sizeof(u.ss), 410 ifp->if_index, ifp->if_type, NULL, namelen, NULL, addrlen); 411 rt_setgate(rt, &u.sa); 412 gate = rt->rt_gateway; 413 } 414 return gate; 415 } 416 417 /* 418 * Parallel to llc_rtrequest. 419 */ 420 void 421 arp_rtrequest(int req, struct rtentry *rt, const struct rt_addrinfo *info) 422 { 423 struct sockaddr *gate = rt->rt_gateway; 424 struct llentry *la = NULL; 425 struct in_ifaddr *ia; 426 struct ifaddr *ifa; 427 struct ifnet *ifp = rt->rt_ifp; 428 int flags = 0; 429 430 if (req == RTM_LLINFO_UPD) { 431 struct in_addr *in; 432 433 if ((ifa = info->rti_ifa) == NULL) 434 return; 435 436 in = &ifatoia(ifa)->ia_addr.sin_addr; 437 438 if (ifatoia(ifa)->ia4_flags & 439 (IN_IFF_NOTREADY | IN_IFF_DETACHED)) 440 { 441 arplog((LOG_DEBUG, "arp_request: %s not ready\n", 442 in_fmtaddr(*in))); 443 return; 444 } 445 446 arprequest(ifa->ifa_ifp, in, in, 447 CLLADDR(ifa->ifa_ifp->if_sadl)); 448 return; 449 } 450 451 if ((rt->rt_flags & RTF_GATEWAY) != 0) { 452 if (req != RTM_ADD) 453 return; 454 455 /* 456 * linklayers with particular link MTU limitation. 457 */ 458 switch(ifp->if_type) { 459 #if NFDDI > 0 460 case IFT_FDDI: 461 if (ifp->if_mtu > FDDIIPMTU) 462 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 463 break; 464 #endif 465 #if NARCNET > 0 466 case IFT_ARCNET: 467 { 468 int arcipifmtu; 469 470 if (ifp->if_flags & IFF_LINK0) 471 arcipifmtu = arc_ipmtu; 472 else 473 arcipifmtu = ARCMTU; 474 if (ifp->if_mtu > arcipifmtu) 475 rt->rt_rmx.rmx_mtu = arcipifmtu; 476 break; 477 } 478 #endif 479 } 480 return; 481 } 482 483 IF_AFDATA_RLOCK(ifp); 484 la = lla_lookup(LLTABLE(ifp), flags, rt_getkey(rt)); 485 IF_AFDATA_RUNLOCK(ifp); 486 487 switch (req) { 488 case RTM_SETGATE: 489 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 490 break; 491 case RTM_ADD: 492 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 493 if (rt->rt_flags & RTF_CLONING || 494 ((rt->rt_flags & (RTF_LLINFO | RTF_LOCAL)) && !la)) 495 { 496 /* 497 * Give this route an expiration time, even though 498 * it's a "permanent" route, so that routes cloned 499 * from it do not need their expiration time set. 500 */ 501 KASSERT(time_uptime != 0); 502 rt->rt_expire = time_uptime; 503 /* 504 * linklayers with particular link MTU limitation. 505 */ 506 switch (ifp->if_type) { 507 #if NFDDI > 0 508 case IFT_FDDI: 509 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 510 (rt->rt_rmx.rmx_mtu > FDDIIPMTU || 511 (rt->rt_rmx.rmx_mtu == 0 && 512 ifp->if_mtu > FDDIIPMTU))) 513 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 514 break; 515 #endif 516 #if NARCNET > 0 517 case IFT_ARCNET: 518 { 519 int arcipifmtu; 520 if (ifp->if_flags & IFF_LINK0) 521 arcipifmtu = arc_ipmtu; 522 else 523 arcipifmtu = ARCMTU; 524 525 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 526 (rt->rt_rmx.rmx_mtu > arcipifmtu || 527 (rt->rt_rmx.rmx_mtu == 0 && 528 ifp->if_mtu > arcipifmtu))) 529 rt->rt_rmx.rmx_mtu = arcipifmtu; 530 break; 531 } 532 #endif 533 } 534 if (rt->rt_flags & RTF_CLONING) 535 break; 536 } 537 /* Announce a new entry if requested. */ 538 if (rt->rt_flags & RTF_ANNOUNCE) { 539 INADDR_TO_IA(satocsin(rt_getkey(rt))->sin_addr, ia); 540 while (ia && ia->ia_ifp != ifp) 541 NEXT_IA_WITH_SAME_ADDR(ia); 542 if (ia == NULL || 543 ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) 544 ; 545 else 546 arprequest(ifp, 547 &satocsin(rt_getkey(rt))->sin_addr, 548 &satocsin(rt_getkey(rt))->sin_addr, 549 CLLADDR(satocsdl(gate))); 550 } 551 /*FALLTHROUGH*/ 552 case RTM_RESOLVE: 553 if (gate->sa_family != AF_LINK || 554 gate->sa_len < sockaddr_dl_measure(0, ifp->if_addrlen)) { 555 log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n"); 556 break; 557 } 558 559 satosdl(gate)->sdl_type = ifp->if_type; 560 satosdl(gate)->sdl_index = ifp->if_index; 561 if (la != NULL) 562 break; /* This happens on a route change */ 563 564 /* If the route is for a broadcast address mark it as such. 565 * This way we can avoid an expensive call to in_broadcast() 566 * in ip_output() most of the time (because the route passed 567 * to ip_output() is almost always a host route). */ 568 if (rt->rt_flags & RTF_HOST && 569 !(rt->rt_flags & RTF_BROADCAST) && 570 in_broadcast(satocsin(rt_getkey(rt))->sin_addr, rt->rt_ifp)) 571 rt->rt_flags |= RTF_BROADCAST; 572 /* There is little point in resolving the broadcast address */ 573 if (rt->rt_flags & RTF_BROADCAST) 574 break; 575 576 INADDR_TO_IA(satocsin(rt_getkey(rt))->sin_addr, ia); 577 while (ia && ia->ia_ifp != ifp) 578 NEXT_IA_WITH_SAME_ADDR(ia); 579 if (ia) { 580 /* 581 * This test used to be 582 * if (lo0ifp->if_flags & IFF_UP) 583 * It allowed local traffic to be forced through 584 * the hardware by configuring the loopback down. 585 * However, it causes problems during network 586 * configuration for boards that can't receive 587 * packets they send. It is now necessary to clear 588 * "useloopback" and remove the route to force 589 * traffic out to the hardware. 590 * 591 * In 4.4BSD, the above "if" statement checked 592 * rt->rt_ifa against rt_getkey(rt). It was changed 593 * to the current form so that we can provide a 594 * better support for multiple IPv4 addresses on a 595 * interface. 596 */ 597 rt->rt_expire = 0; 598 if (sockaddr_dl_init(satosdl(gate), gate->sa_len, 599 ifp->if_index, ifp->if_type, NULL, 0, 600 CLLADDR(ifp->if_sadl), ifp->if_addrlen) == NULL) { 601 panic("%s(%s): sockaddr_dl_init cannot fail", 602 __func__, ifp->if_xname); 603 } 604 if (useloopback) { 605 ifp = rt->rt_ifp = lo0ifp; 606 rt->rt_rmx.rmx_mtu = 0; 607 } 608 rt->rt_flags |= RTF_LOCAL; 609 /* 610 * make sure to set rt->rt_ifa to the interface 611 * address we are using, otherwise we will have trouble 612 * with source address selection. 613 */ 614 ifa = &ia->ia_ifa; 615 if (ifa != rt->rt_ifa) 616 rt_replace_ifa(rt, ifa); 617 } 618 619 /* 620 * Case 2: This route may come from cloning, or a manual route 621 * add with a LL address. 622 */ 623 flags = LLE_EXCLUSIVE; 624 if ((rt->rt_flags & RTF_CLONED) == 0) 625 flags |= LLE_IFADDR; 626 627 IF_AFDATA_WLOCK(ifp); 628 la = lla_create(LLTABLE(ifp), flags, rt_getkey(rt)); 629 IF_AFDATA_WUNLOCK(ifp); 630 631 if (la == NULL) { 632 log(LOG_DEBUG, "%s: lla_create failed\n", 633 __func__); 634 rt->rt_llinfo = NULL; 635 break; 636 } 637 rt->rt_llinfo = la; 638 LLE_ADDREF(la); 639 switch (ifp->if_type) { 640 #if NTOKEN > 0 641 case IFT_ISO88025: 642 la->la_opaque = kmem_alloc(sizeof(struct token_rif), 643 KM_SLEEP); 644 break; 645 #endif /* NTOKEN > 0 */ 646 default: 647 break; 648 } 649 la->la_rt = rt; 650 rt->rt_refcnt++; 651 rt->rt_flags |= RTF_LLINFO; 652 arp_inuse++, arp_allocated++; 653 654 LLE_WUNLOCK(la); 655 la = NULL; 656 657 break; 658 659 case RTM_DELETE: 660 if (la == NULL) 661 break; 662 arp_inuse--; 663 rt->rt_llinfo = NULL; 664 rt->rt_flags &= ~RTF_LLINFO; 665 666 /* Have to do before IF_AFDATA_WLOCK to avoid deadlock */ 667 callout_halt(&la->la_timer, &la->lle_lock); 668 /* XXX: LOR avoidance. We still have ref on lle. */ 669 LLE_RUNLOCK(la); 670 671 flags |= LLE_EXCLUSIVE; 672 IF_AFDATA_WLOCK(ifp); 673 LLE_WLOCK(la); 674 675 if (la->la_opaque != NULL) { 676 switch (ifp->if_type) { 677 #if NTOKEN > 0 678 case IFT_ISO88025: 679 kmem_free(la->la_opaque, 680 sizeof(struct token_rif)); 681 break; 682 #endif /* NTOKEN > 0 */ 683 default: 684 break; 685 } 686 } 687 688 if (la->la_rt != NULL) { 689 /* 690 * Don't rtfree (may actually free objects) here. 691 * Leave it to rtrequest1. 692 */ 693 la->la_rt->rt_refcnt--; 694 la->la_rt = NULL; 695 } 696 697 /* Guard against race with other llentry_free(). */ 698 if (la->la_flags & LLE_LINKED) { 699 size_t pkts_dropped; 700 701 LLE_REMREF(la); 702 pkts_dropped = llentry_free(la); 703 ARP_STATADD(ARP_STAT_DFRDROPPED, pkts_dropped); 704 } else { 705 LLE_FREE_LOCKED(la); 706 } 707 la = NULL; 708 709 IF_AFDATA_WUNLOCK(ifp); 710 } 711 712 if (la != NULL) { 713 if (flags & LLE_EXCLUSIVE) 714 LLE_WUNLOCK(la); 715 else 716 LLE_RUNLOCK(la); 717 } 718 } 719 720 /* 721 * Broadcast an ARP request. Caller specifies: 722 * - arp header source ip address 723 * - arp header target ip address 724 * - arp header source ethernet address 725 */ 726 void 727 arprequest(struct ifnet *ifp, 728 const struct in_addr *sip, const struct in_addr *tip, 729 const u_int8_t *enaddr) 730 { 731 struct mbuf *m; 732 struct arphdr *ah; 733 struct sockaddr sa; 734 uint64_t *arps; 735 736 KASSERT(sip != NULL); 737 KASSERT(tip != NULL); 738 KASSERT(enaddr != NULL); 739 740 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 741 return; 742 MCLAIM(m, &arpdomain.dom_mowner); 743 switch (ifp->if_type) { 744 case IFT_IEEE1394: 745 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 746 ifp->if_addrlen; 747 break; 748 default: 749 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 750 2 * ifp->if_addrlen; 751 break; 752 } 753 m->m_pkthdr.len = m->m_len; 754 MH_ALIGN(m, m->m_len); 755 ah = mtod(m, struct arphdr *); 756 memset(ah, 0, m->m_len); 757 switch (ifp->if_type) { 758 case IFT_IEEE1394: /* RFC2734 */ 759 /* fill it now for ar_tpa computation */ 760 ah->ar_hrd = htons(ARPHRD_IEEE1394); 761 break; 762 default: 763 /* ifp->if_output will fill ar_hrd */ 764 break; 765 } 766 ah->ar_pro = htons(ETHERTYPE_IP); 767 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 768 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 769 ah->ar_op = htons(ARPOP_REQUEST); 770 memcpy(ar_sha(ah), enaddr, ah->ar_hln); 771 memcpy(ar_spa(ah), sip, ah->ar_pln); 772 memcpy(ar_tpa(ah), tip, ah->ar_pln); 773 sa.sa_family = AF_ARP; 774 sa.sa_len = 2; 775 m->m_flags |= M_BCAST; 776 arps = ARP_STAT_GETREF(); 777 arps[ARP_STAT_SNDTOTAL]++; 778 arps[ARP_STAT_SENDREQUEST]++; 779 ARP_STAT_PUTREF(); 780 (*ifp->if_output)(ifp, m, &sa, NULL); 781 } 782 783 /* 784 * Resolve an IP address into an ethernet address. If success, 785 * desten is filled in. If there is no entry in arptab, 786 * set one up and broadcast a request for the IP address. 787 * Hold onto this mbuf and resend it once the address 788 * is finally resolved. A return value of 0 indicates 789 * that desten has been filled in and the packet should be sent 790 * normally; a return value of EWOULDBLOCK indicates that the packet has been 791 * held pending resolution. 792 * Any other value indicates an error. 793 */ 794 int 795 arpresolve(struct ifnet *ifp, struct rtentry *rt, struct mbuf *m, 796 const struct sockaddr *dst, u_char *desten) 797 { 798 struct llentry *la; 799 const struct sockaddr_dl *sdl; 800 const char *create_lookup; 801 bool renew; 802 int error; 803 804 KASSERT(m != NULL); 805 806 la = arplookup(ifp, m, &satocsin(dst)->sin_addr, 0, 0, 0, rt); 807 if (la == NULL || la->la_rt == NULL) 808 goto notfound; 809 810 rt = la->la_rt; 811 sdl = satocsdl(rt->rt_gateway); 812 /* 813 * Check the address family and length is valid, the address 814 * is resolved; otherwise, try to resolve. 815 */ 816 if ((rt->rt_expire == 0 || rt->rt_expire > time_uptime) && 817 sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) { 818 memcpy(desten, CLLADDR(sdl), 819 min(sdl->sdl_alen, ifp->if_addrlen)); 820 rt->rt_pksent = time_uptime; /* Time for last pkt sent */ 821 LLE_RUNLOCK(la); 822 return 0; 823 } 824 825 /* 826 * Re-send the ARP request when appropriate. 827 */ 828 #ifdef DIAGNOSTIC 829 if (rt->rt_expire == 0) { 830 /* This should never happen. (Should it? -gwr) */ 831 printf("arpresolve: unresolved and rt_expire == 0\n"); 832 /* Set expiration time to now (expired). */ 833 rt->rt_expire = time_uptime; 834 } 835 #endif 836 837 notfound: 838 #ifdef IFF_STATICARP /* FreeBSD */ 839 #define _IFF_NOARP (IFF_NOARP | IFF_STATICARP) 840 #else 841 #define _IFF_NOARP IFF_NOARP 842 #endif 843 if (ifp->if_flags & _IFF_NOARP) { 844 if (la != NULL) 845 LLE_RUNLOCK(la); 846 error = ENOTSUP; 847 goto bad; 848 } 849 #undef _IFF_NOARP 850 if (la == NULL) { 851 create_lookup = "create"; 852 IF_AFDATA_WLOCK(ifp); 853 la = lla_create(LLTABLE(ifp), LLE_EXCLUSIVE, dst); 854 IF_AFDATA_WUNLOCK(ifp); 855 if (la == NULL) 856 ARP_STATINC(ARP_STAT_ALLOCFAIL); 857 } else if (LLE_TRY_UPGRADE(la) == 0) { 858 create_lookup = "lookup"; 859 LLE_RUNLOCK(la); 860 IF_AFDATA_RLOCK(ifp); 861 la = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst); 862 IF_AFDATA_RUNLOCK(ifp); 863 } 864 865 error = EINVAL; 866 if (la == NULL) { 867 log(LOG_DEBUG, 868 "%s: failed to %s llentry for %s on %s\n", 869 __func__, create_lookup, inet_ntoa(satocsin(dst)->sin_addr), 870 ifp->if_xname); 871 goto bad; 872 } 873 874 /* Just in case */ 875 if (la->la_rt == NULL) { 876 LLE_WUNLOCK(la); 877 log(LOG_DEBUG, 878 "%s: valid llentry has no rtentry for %s on %s\n", 879 __func__, inet_ntoa(satocsin(dst)->sin_addr), 880 ifp->if_xname); 881 goto bad; 882 } 883 rt = la->la_rt; 884 885 if ((la->la_flags & LLE_VALID) && 886 ((la->la_flags & LLE_STATIC) || la->la_expire > time_uptime)) 887 { 888 sdl = satocsdl(rt->rt_gateway); 889 memcpy(desten, CLLADDR(sdl), 890 min(sdl->sdl_alen, ifp->if_addrlen)); 891 renew = false; 892 /* 893 * If entry has an expiry time and it is approaching, 894 * see if we need to send an ARP request within this 895 * arpt_down interval. 896 */ 897 if (!(la->la_flags & LLE_STATIC) && 898 time_uptime + la->la_preempt > la->la_expire) 899 { 900 renew = true; 901 la->la_preempt--; 902 } 903 904 LLE_WUNLOCK(la); 905 906 if (renew) { 907 const u_int8_t *enaddr = 908 #if NCARP > 0 909 (rt->rt_ifp->if_type == IFT_CARP) ? 910 CLLADDR(rt->rt_ifp->if_sadl): 911 #endif 912 CLLADDR(ifp->if_sadl); 913 arprequest(ifp, 914 &satocsin(rt->rt_ifa->ifa_addr)->sin_addr, 915 &satocsin(dst)->sin_addr, enaddr); 916 } 917 918 return 0; 919 } 920 921 if (la->la_flags & LLE_STATIC) { /* should not happen! */ 922 LLE_RUNLOCK(la); 923 log(LOG_DEBUG, "arpresolve: ouch, empty static llinfo for %s\n", 924 inet_ntoa(satocsin(dst)->sin_addr)); 925 error = EINVAL; 926 goto bad; 927 } 928 929 renew = (la->la_asked == 0 || la->la_expire != time_uptime); 930 931 /* 932 * There is an arptab entry, but no ethernet address 933 * response yet. Add the mbuf to the list, dropping 934 * the oldest packet if we have exceeded the system 935 * setting. 936 */ 937 LLE_WLOCK_ASSERT(la); 938 if (la->la_numheld >= arp_maxhold) { 939 if (la->la_hold != NULL) { 940 struct mbuf *next = la->la_hold->m_nextpkt; 941 m_freem(la->la_hold); 942 la->la_hold = next; 943 la->la_numheld--; 944 ARP_STATINC(ARP_STAT_DFRDROPPED); 945 } 946 } 947 if (la->la_hold != NULL) { 948 struct mbuf *curr = la->la_hold; 949 while (curr->m_nextpkt != NULL) 950 curr = curr->m_nextpkt; 951 curr->m_nextpkt = m; 952 } else 953 la->la_hold = m; 954 la->la_numheld++; 955 if (!renew) 956 LLE_DOWNGRADE(la); 957 958 /* 959 * Return EWOULDBLOCK if we have tried less than arp_maxtries. It 960 * will be masked by ether_output(). Return EHOSTDOWN/EHOSTUNREACH 961 * if we have already sent arp_maxtries ARP requests. Retransmit the 962 * ARP request, but not faster than one request per second. 963 */ 964 if (la->la_asked < arp_maxtries) 965 error = EWOULDBLOCK; /* First request. */ 966 else 967 error = (rt->rt_flags & RTF_GATEWAY) ? 968 EHOSTUNREACH : EHOSTDOWN; 969 970 if (renew) { 971 const u_int8_t *enaddr = 972 #if NCARP > 0 973 (rt->rt_ifp->if_type == IFT_CARP) ? 974 CLLADDR(rt->rt_ifp->if_sadl): 975 #endif 976 CLLADDR(ifp->if_sadl); 977 LLE_ADDREF(la); 978 la->la_expire = time_uptime; 979 callout_reset(&la->la_timer, hz * arpt_down, 980 arptimer, la); 981 la->la_asked++; 982 LLE_WUNLOCK(la); 983 984 arprequest(ifp, &satocsin(rt->rt_ifa->ifa_addr)->sin_addr, 985 &satocsin(dst)->sin_addr, enaddr); 986 return error; 987 } 988 989 LLE_RUNLOCK(la); 990 return error; 991 992 bad: 993 m_freem(m); 994 if (rt != NULL && (rt->rt_flags & RTF_CLONED) != 0) { 995 rtrequest(RTM_DELETE, rt_getkey(rt), 996 rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL); 997 } 998 return error; 999 } 1000 1001 /* 1002 * Common length and type checks are done here, 1003 * then the protocol-specific routine is called. 1004 */ 1005 void 1006 arpintr(void) 1007 { 1008 struct mbuf *m; 1009 struct arphdr *ar; 1010 int s; 1011 int arplen; 1012 1013 mutex_enter(softnet_lock); 1014 KERNEL_LOCK(1, NULL); 1015 while (arpintrq.ifq_head) { 1016 s = splnet(); 1017 IF_DEQUEUE(&arpintrq, m); 1018 splx(s); 1019 if (m == NULL || (m->m_flags & M_PKTHDR) == 0) 1020 panic("arpintr"); 1021 1022 MCLAIM(m, &arpdomain.dom_mowner); 1023 ARP_STATINC(ARP_STAT_RCVTOTAL); 1024 1025 /* 1026 * First, make sure we have at least struct arphdr. 1027 */ 1028 if (m->m_len < sizeof(struct arphdr) || 1029 (ar = mtod(m, struct arphdr *)) == NULL) 1030 goto badlen; 1031 1032 switch (m->m_pkthdr.rcvif->if_type) { 1033 case IFT_IEEE1394: 1034 arplen = sizeof(struct arphdr) + 1035 ar->ar_hln + 2 * ar->ar_pln; 1036 break; 1037 default: 1038 arplen = sizeof(struct arphdr) + 1039 2 * ar->ar_hln + 2 * ar->ar_pln; 1040 break; 1041 } 1042 1043 if (/* XXX ntohs(ar->ar_hrd) == ARPHRD_ETHER && */ 1044 m->m_len >= arplen) 1045 switch (ntohs(ar->ar_pro)) { 1046 case ETHERTYPE_IP: 1047 case ETHERTYPE_IPTRAILERS: 1048 in_arpinput(m); 1049 continue; 1050 default: 1051 ARP_STATINC(ARP_STAT_RCVBADPROTO); 1052 } 1053 else { 1054 badlen: 1055 ARP_STATINC(ARP_STAT_RCVBADLEN); 1056 } 1057 m_freem(m); 1058 } 1059 KERNEL_UNLOCK_ONE(NULL); 1060 mutex_exit(softnet_lock); 1061 } 1062 1063 /* 1064 * ARP for Internet protocols on 10 Mb/s Ethernet. 1065 * Algorithm is that given in RFC 826. 1066 * In addition, a sanity check is performed on the sender 1067 * protocol address, to catch impersonators. 1068 * We no longer handle negotiations for use of trailer protocol: 1069 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent 1070 * along with IP replies if we wanted trailers sent to us, 1071 * and also sent them in response to IP replies. 1072 * This allowed either end to announce the desire to receive 1073 * trailer packets. 1074 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, 1075 * but formerly didn't normally send requests. 1076 */ 1077 static void 1078 in_arpinput(struct mbuf *m) 1079 { 1080 struct arphdr *ah; 1081 struct ifnet *ifp = m->m_pkthdr.rcvif; 1082 struct llentry *la = NULL; 1083 struct rtentry *rt = NULL; 1084 struct in_ifaddr *ia; 1085 #if NBRIDGE > 0 1086 struct in_ifaddr *bridge_ia = NULL; 1087 #endif 1088 #if NCARP > 0 1089 u_int32_t count = 0, index = 0; 1090 #endif 1091 struct sockaddr_dl *sdl = NULL; 1092 struct sockaddr sa; 1093 struct in_addr isaddr, itaddr, myaddr; 1094 int op; 1095 void *tha; 1096 uint64_t *arps; 1097 1098 if (__predict_false(m_makewritable(&m, 0, m->m_pkthdr.len, M_DONTWAIT))) 1099 goto out; 1100 ah = mtod(m, struct arphdr *); 1101 op = ntohs(ah->ar_op); 1102 1103 /* 1104 * Fix up ah->ar_hrd if necessary, before using ar_tha() or 1105 * ar_tpa(). 1106 */ 1107 switch (ifp->if_type) { 1108 case IFT_IEEE1394: 1109 if (ntohs(ah->ar_hrd) == ARPHRD_IEEE1394) 1110 ; 1111 else { 1112 /* XXX this is to make sure we compute ar_tha right */ 1113 /* XXX check ar_hrd more strictly? */ 1114 ah->ar_hrd = htons(ARPHRD_IEEE1394); 1115 } 1116 break; 1117 default: 1118 /* XXX check ar_hrd? */ 1119 break; 1120 } 1121 1122 memcpy(&isaddr, ar_spa(ah), sizeof (isaddr)); 1123 memcpy(&itaddr, ar_tpa(ah), sizeof (itaddr)); 1124 1125 if (m->m_flags & (M_BCAST|M_MCAST)) 1126 ARP_STATINC(ARP_STAT_RCVMCAST); 1127 1128 1129 /* 1130 * Search for a matching interface address 1131 * or any address on the interface to use 1132 * as a dummy address in the rest of this function 1133 */ 1134 1135 INADDR_TO_IA(itaddr, ia); 1136 while (ia != NULL) { 1137 #if NCARP > 0 1138 if (ia->ia_ifp->if_type == IFT_CARP && 1139 ((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) == 1140 (IFF_UP|IFF_RUNNING))) { 1141 index++; 1142 if (ia->ia_ifp == m->m_pkthdr.rcvif && 1143 carp_iamatch(ia, ar_sha(ah), 1144 &count, index)) { 1145 break; 1146 } 1147 } else 1148 #endif 1149 if (ia->ia_ifp == m->m_pkthdr.rcvif) 1150 break; 1151 #if NBRIDGE > 0 1152 /* 1153 * If the interface we received the packet on 1154 * is part of a bridge, check to see if we need 1155 * to "bridge" the packet to ourselves at this 1156 * layer. Note we still prefer a perfect match, 1157 * but allow this weaker match if necessary. 1158 */ 1159 if (m->m_pkthdr.rcvif->if_bridge != NULL && 1160 m->m_pkthdr.rcvif->if_bridge == ia->ia_ifp->if_bridge) 1161 bridge_ia = ia; 1162 #endif /* NBRIDGE > 0 */ 1163 1164 NEXT_IA_WITH_SAME_ADDR(ia); 1165 } 1166 1167 #if NBRIDGE > 0 1168 if (ia == NULL && bridge_ia != NULL) { 1169 ia = bridge_ia; 1170 ifp = bridge_ia->ia_ifp; 1171 } 1172 #endif 1173 1174 if (ia == NULL) { 1175 INADDR_TO_IA(isaddr, ia); 1176 while ((ia != NULL) && ia->ia_ifp != m->m_pkthdr.rcvif) 1177 NEXT_IA_WITH_SAME_ADDR(ia); 1178 1179 if (ia == NULL) { 1180 IFP_TO_IA(ifp, ia); 1181 if (ia == NULL) { 1182 ARP_STATINC(ARP_STAT_RCVNOINT); 1183 goto out; 1184 } 1185 } 1186 } 1187 1188 myaddr = ia->ia_addr.sin_addr; 1189 1190 /* XXX checks for bridge case? */ 1191 if (!memcmp(ar_sha(ah), CLLADDR(ifp->if_sadl), ifp->if_addrlen)) { 1192 ARP_STATINC(ARP_STAT_RCVLOCALSHA); 1193 goto out; /* it's from me, ignore it. */ 1194 } 1195 1196 /* XXX checks for bridge case? */ 1197 if (!memcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 1198 ARP_STATINC(ARP_STAT_RCVBCASTSHA); 1199 log(LOG_ERR, 1200 "%s: arp: link address is broadcast for IP address %s!\n", 1201 ifp->if_xname, in_fmtaddr(isaddr)); 1202 goto out; 1203 } 1204 1205 /* 1206 * If the source IP address is zero, this is an RFC 5227 ARP probe 1207 */ 1208 if (in_nullhost(isaddr)) 1209 ARP_STATINC(ARP_STAT_RCVZEROSPA); 1210 else if (in_hosteq(isaddr, myaddr)) 1211 ARP_STATINC(ARP_STAT_RCVLOCALSPA); 1212 1213 if (in_nullhost(itaddr)) 1214 ARP_STATINC(ARP_STAT_RCVZEROTPA); 1215 1216 /* DAD check, RFC 5227 2.1.1, Probe Details */ 1217 if (in_hosteq(isaddr, myaddr) || 1218 (in_nullhost(isaddr) && in_hosteq(itaddr, myaddr))) 1219 { 1220 /* If our address is tentative, mark it as duplicated */ 1221 if (ia->ia4_flags & IN_IFF_TENTATIVE) 1222 arp_dad_duplicated((struct ifaddr *)ia); 1223 /* If our address is unuseable, don't reply */ 1224 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) 1225 goto out; 1226 } 1227 1228 /* 1229 * If the target IP address is zero, ignore the packet. 1230 * This prevents the code below from tring to answer 1231 * when we are using IP address zero (booting). 1232 */ 1233 if (in_nullhost(itaddr)) 1234 goto out; 1235 1236 if (in_nullhost(isaddr)) 1237 goto reply; 1238 1239 if (in_hosteq(isaddr, myaddr)) { 1240 log(LOG_ERR, 1241 "duplicate IP address %s sent from link address %s\n", 1242 in_fmtaddr(isaddr), lla_snprintf(ar_sha(ah), ah->ar_hln)); 1243 itaddr = myaddr; 1244 goto reply; 1245 } 1246 1247 la = arplookup(ifp, m, &isaddr, in_hosteq(itaddr, myaddr), 0, 1, NULL); 1248 if (la != NULL) { 1249 rt = la->la_rt; 1250 if (rt != NULL) 1251 sdl = satosdl(rt->rt_gateway); 1252 } 1253 if (sdl != NULL) { 1254 if (sdl->sdl_alen && 1255 memcmp(ar_sha(ah), CLLADDR(sdl), sdl->sdl_alen)) { 1256 if (rt->rt_flags & RTF_STATIC) { 1257 ARP_STATINC(ARP_STAT_RCVOVERPERM); 1258 if (!log_permanent_modify) 1259 goto out; 1260 log(LOG_INFO, 1261 "%s tried to overwrite permanent arp info" 1262 " for %s\n", 1263 lla_snprintf(ar_sha(ah), ah->ar_hln), 1264 in_fmtaddr(isaddr)); 1265 goto out; 1266 } else if (rt->rt_ifp != ifp) { 1267 ARP_STATINC(ARP_STAT_RCVOVERINT); 1268 if (!log_wrong_iface) 1269 goto out; 1270 log(LOG_INFO, 1271 "%s on %s tried to overwrite " 1272 "arp info for %s on %s\n", 1273 lla_snprintf(ar_sha(ah), ah->ar_hln), 1274 ifp->if_xname, in_fmtaddr(isaddr), 1275 rt->rt_ifp->if_xname); 1276 goto out; 1277 } else { 1278 ARP_STATINC(ARP_STAT_RCVOVER); 1279 if (log_movements) 1280 log(LOG_INFO, "arp info overwritten " 1281 "for %s by %s\n", 1282 in_fmtaddr(isaddr), 1283 lla_snprintf(ar_sha(ah), 1284 ah->ar_hln)); 1285 } 1286 } 1287 /* 1288 * sanity check for the address length. 1289 * XXX this does not work for protocols with variable address 1290 * length. -is 1291 */ 1292 if (sdl->sdl_alen && 1293 sdl->sdl_alen != ah->ar_hln) { 1294 ARP_STATINC(ARP_STAT_RCVLENCHG); 1295 log(LOG_WARNING, 1296 "arp from %s: new addr len %d, was %d\n", 1297 in_fmtaddr(isaddr), ah->ar_hln, sdl->sdl_alen); 1298 } 1299 if (ifp->if_addrlen != ah->ar_hln) { 1300 ARP_STATINC(ARP_STAT_RCVBADLEN); 1301 log(LOG_WARNING, 1302 "arp from %s: addr len: new %d, i/f %d (ignored)\n", 1303 in_fmtaddr(isaddr), ah->ar_hln, 1304 ifp->if_addrlen); 1305 goto reply; 1306 } 1307 #if NTOKEN > 0 1308 /* 1309 * XXX uses m_data and assumes the complete answer including 1310 * XXX token-ring headers is in the same buf 1311 */ 1312 if (ifp->if_type == IFT_ISO88025) { 1313 struct token_header *trh; 1314 1315 trh = (struct token_header *)M_TRHSTART(m); 1316 if (trh->token_shost[0] & TOKEN_RI_PRESENT) { 1317 struct token_rif *rif; 1318 size_t riflen; 1319 1320 rif = TOKEN_RIF(trh); 1321 riflen = (ntohs(rif->tr_rcf) & 1322 TOKEN_RCF_LEN_MASK) >> 8; 1323 1324 if (riflen > 2 && 1325 riflen < sizeof(struct token_rif) && 1326 (riflen & 1) == 0) { 1327 rif->tr_rcf ^= htons(TOKEN_RCF_DIRECTION); 1328 rif->tr_rcf &= htons(~TOKEN_RCF_BROADCAST_MASK); 1329 memcpy(TOKEN_RIF(la), rif, riflen); 1330 } 1331 } 1332 } 1333 #endif /* NTOKEN > 0 */ 1334 (void)sockaddr_dl_setaddr(sdl, sdl->sdl_len, ar_sha(ah), 1335 ah->ar_hln); 1336 if (rt->rt_expire) { 1337 rt->rt_expire = time_uptime + arpt_keep; 1338 1339 KASSERT((la->la_flags & LLE_STATIC) == 0); 1340 LLE_ADDREF(la); 1341 callout_reset(&la->la_timer, hz * arpt_keep, arptimer, la); 1342 } 1343 rt->rt_flags &= ~RTF_REJECT; 1344 la->la_asked = 0; 1345 1346 if (la->la_hold != NULL) { 1347 int n = la->la_numheld; 1348 struct mbuf *m_hold, *m_hold_next; 1349 1350 m_hold = la->la_hold; 1351 la->la_hold = NULL; 1352 la->la_numheld = 0; 1353 /* 1354 * We have to unlock here because if_output would call 1355 * arpresolve 1356 */ 1357 LLE_WUNLOCK(la); 1358 ARP_STATADD(ARP_STAT_DFRSENT, n); 1359 for (; m_hold != NULL; m_hold = m_hold_next) { 1360 m_hold_next = m_hold->m_nextpkt; 1361 m_hold->m_nextpkt = NULL; 1362 (*ifp->if_output)(ifp, m_hold, rt_getkey(rt), rt); 1363 } 1364 } else 1365 LLE_WUNLOCK(la); 1366 la = NULL; 1367 } 1368 reply: 1369 if (la != NULL) { 1370 LLE_WUNLOCK(la); 1371 la = NULL; 1372 } 1373 if (op != ARPOP_REQUEST) { 1374 if (op == ARPOP_REPLY) 1375 ARP_STATINC(ARP_STAT_RCVREPLY); 1376 goto out; 1377 } 1378 ARP_STATINC(ARP_STAT_RCVREQUEST); 1379 if (in_hosteq(itaddr, myaddr)) { 1380 /* If our address is unuseable, don't reply */ 1381 if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) 1382 goto out; 1383 /* I am the target */ 1384 tha = ar_tha(ah); 1385 if (tha) 1386 memcpy(tha, ar_sha(ah), ah->ar_hln); 1387 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1388 } else { 1389 la = arplookup(ifp, m, &itaddr, 0, SIN_PROXY, 0, NULL); 1390 if (la == NULL) 1391 goto out; 1392 rt = la->la_rt; 1393 LLE_RUNLOCK(la); 1394 la = NULL; 1395 if (rt->rt_ifp->if_type == IFT_CARP && 1396 m->m_pkthdr.rcvif->if_type != IFT_CARP) 1397 goto out; 1398 tha = ar_tha(ah); 1399 if (tha) 1400 memcpy(tha, ar_sha(ah), ah->ar_hln); 1401 sdl = satosdl(rt->rt_gateway); 1402 memcpy(ar_sha(ah), CLLADDR(sdl), ah->ar_hln); 1403 } 1404 1405 memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); 1406 memcpy(ar_spa(ah), &itaddr, ah->ar_pln); 1407 ah->ar_op = htons(ARPOP_REPLY); 1408 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 1409 switch (ifp->if_type) { 1410 case IFT_IEEE1394: 1411 /* 1412 * ieee1394 arp reply is broadcast 1413 */ 1414 m->m_flags &= ~M_MCAST; 1415 m->m_flags |= M_BCAST; 1416 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + ah->ar_hln; 1417 break; 1418 1419 default: 1420 m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */ 1421 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); 1422 break; 1423 } 1424 m->m_pkthdr.len = m->m_len; 1425 sa.sa_family = AF_ARP; 1426 sa.sa_len = 2; 1427 arps = ARP_STAT_GETREF(); 1428 arps[ARP_STAT_SNDTOTAL]++; 1429 arps[ARP_STAT_SNDREPLY]++; 1430 ARP_STAT_PUTREF(); 1431 (*ifp->if_output)(ifp, m, &sa, NULL); 1432 return; 1433 1434 out: 1435 if (la != NULL) 1436 LLE_WUNLOCK(la); 1437 m_freem(m); 1438 } 1439 1440 /* 1441 * Free an arp entry. 1442 */ 1443 static void arptfree(struct rtentry *rt) 1444 { 1445 1446 rtrequest(RTM_DELETE, rt_getkey(rt), NULL, rt_mask(rt), 0, NULL); 1447 rtfree(rt); 1448 } 1449 1450 /* 1451 * Lookup or enter a new address in arptab. 1452 */ 1453 static struct llentry * 1454 arplookup(struct ifnet *ifp, struct mbuf *m, const struct in_addr *addr, 1455 int create, int proxy, int wlock, struct rtentry *rt0) 1456 { 1457 struct arphdr *ah; 1458 struct rtentry *rt; 1459 struct sockaddr_inarp sin; 1460 const char *why = NULL; 1461 1462 ah = mtod(m, struct arphdr *); 1463 if (rt0 == NULL) { 1464 memset(&sin, 0, sizeof(sin)); 1465 sin.sin_len = sizeof(sin); 1466 sin.sin_family = AF_INET; 1467 sin.sin_addr = *addr; 1468 sin.sin_other = proxy ? SIN_PROXY : 0; 1469 rt = rtalloc1(sintosa(&sin), create); 1470 if (rt == NULL) 1471 return NULL; 1472 rt->rt_refcnt--; 1473 } else 1474 rt = rt0; 1475 1476 #define IS_LLINFO(__rt) \ 1477 (((__rt)->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) == RTF_LLINFO && \ 1478 (__rt)->rt_gateway->sa_family == AF_LINK) 1479 1480 1481 if (IS_LLINFO(rt)) { 1482 struct llentry *la; 1483 int flags = wlock ? LLE_EXCLUSIVE : 0; 1484 1485 IF_AFDATA_RLOCK(ifp); 1486 la = lla_lookup(LLTABLE(ifp), flags, rt_getkey(rt)); 1487 IF_AFDATA_RUNLOCK(ifp); 1488 1489 if (la == NULL && create) { 1490 IF_AFDATA_WLOCK(ifp); 1491 la = lla_create(LLTABLE(ifp), flags, rt_getkey(rt)); 1492 IF_AFDATA_WUNLOCK(ifp); 1493 } 1494 1495 return la; 1496 } 1497 1498 if (create) { 1499 if (rt->rt_flags & RTF_GATEWAY) { 1500 if (log_unknown_network) 1501 why = "host is not on local network"; 1502 } else if ((rt->rt_flags & RTF_LLINFO) == 0) { 1503 ARP_STATINC(ARP_STAT_ALLOCFAIL); 1504 why = "could not allocate llinfo"; 1505 } else 1506 why = "gateway route is not ours"; 1507 if (why) { 1508 log(LOG_DEBUG, "arplookup: unable to enter address" 1509 " for %s@%s on %s (%s)\n", in_fmtaddr(*addr), 1510 lla_snprintf(ar_sha(ah), ah->ar_hln), 1511 (ifp) ? ifp->if_xname : "null", why); 1512 } 1513 if ((rt->rt_flags & RTF_CLONED) != 0) { 1514 rtrequest(RTM_DELETE, rt_getkey(rt), 1515 rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL); 1516 } 1517 } 1518 return NULL; 1519 } 1520 1521 int 1522 arpioctl(u_long cmd, void *data) 1523 { 1524 1525 return EOPNOTSUPP; 1526 } 1527 1528 void 1529 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1530 { 1531 struct in_addr *ip; 1532 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1533 1534 /* 1535 * Warn the user if another station has this IP address, 1536 * but only if the interface IP address is not zero. 1537 */ 1538 ip = &IA_SIN(ifa)->sin_addr; 1539 if (!in_nullhost(*ip) && 1540 (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) == 0) 1541 arprequest(ifp, ip, ip, CLLADDR(ifp->if_sadl)); 1542 1543 ifa->ifa_rtrequest = arp_rtrequest; 1544 ifa->ifa_flags |= RTF_CLONING; 1545 1546 /* ARP will handle DAD for this address. */ 1547 if (ia->ia4_flags & IN_IFF_TRYTENTATIVE) { 1548 ia->ia4_flags |= IN_IFF_TENTATIVE; 1549 ia->ia_dad_start = arp_dad_start; 1550 ia->ia_dad_stop = arp_dad_stop; 1551 } 1552 } 1553 1554 TAILQ_HEAD(dadq_head, dadq); 1555 struct dadq { 1556 TAILQ_ENTRY(dadq) dad_list; 1557 struct ifaddr *dad_ifa; 1558 int dad_count; /* max ARP to send */ 1559 int dad_arp_tcount; /* # of trials to send ARP */ 1560 int dad_arp_ocount; /* ARP sent so far */ 1561 int dad_arp_announce; /* max ARP announcements */ 1562 int dad_arp_acount; /* # of announcements */ 1563 struct callout dad_timer_ch; 1564 }; 1565 MALLOC_JUSTDEFINE(M_IPARP, "ARP DAD", "ARP DAD Structure"); 1566 1567 static struct dadq_head dadq; 1568 static int dad_init = 0; 1569 static int dad_maxtry = 15; /* max # of *tries* to transmit DAD packet */ 1570 1571 static struct dadq * 1572 arp_dad_find(struct ifaddr *ifa) 1573 { 1574 struct dadq *dp; 1575 1576 TAILQ_FOREACH(dp, &dadq, dad_list) { 1577 if (dp->dad_ifa == ifa) 1578 return dp; 1579 } 1580 return NULL; 1581 } 1582 1583 static void 1584 arp_dad_starttimer(struct dadq *dp, int ticks) 1585 { 1586 1587 callout_reset(&dp->dad_timer_ch, ticks, 1588 (void (*)(void *))arp_dad_timer, (void *)dp->dad_ifa); 1589 } 1590 1591 static void 1592 arp_dad_stoptimer(struct dadq *dp) 1593 { 1594 1595 callout_stop(&dp->dad_timer_ch); 1596 } 1597 1598 static void 1599 arp_dad_output(struct dadq *dp, struct ifaddr *ifa) 1600 { 1601 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1602 struct ifnet *ifp = ifa->ifa_ifp; 1603 struct in_addr sip; 1604 1605 dp->dad_arp_tcount++; 1606 if ((ifp->if_flags & IFF_UP) == 0) 1607 return; 1608 if ((ifp->if_flags & IFF_RUNNING) == 0) 1609 return; 1610 1611 dp->dad_arp_tcount = 0; 1612 dp->dad_arp_ocount++; 1613 1614 memset(&sip, 0, sizeof(sip)); 1615 arprequest(ifa->ifa_ifp, &sip, &ia->ia_addr.sin_addr, 1616 CLLADDR(ifa->ifa_ifp->if_sadl)); 1617 } 1618 1619 /* 1620 * Start Duplicate Address Detection (DAD) for specified interface address. 1621 */ 1622 static void 1623 arp_dad_start(struct ifaddr *ifa) 1624 { 1625 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1626 struct dadq *dp; 1627 1628 if (!dad_init) { 1629 TAILQ_INIT(&dadq); 1630 dad_init++; 1631 } 1632 1633 /* 1634 * If we don't need DAD, don't do it. 1635 * - DAD is disabled (ip_dad_count == 0) 1636 */ 1637 if (!(ia->ia4_flags & IN_IFF_TENTATIVE)) { 1638 log(LOG_DEBUG, 1639 "arp_dad_start: called with non-tentative address " 1640 "%s(%s)\n", 1641 in_fmtaddr(ia->ia_addr.sin_addr), 1642 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1643 return; 1644 } 1645 if (!ip_dad_count) { 1646 struct in_addr *ip = &IA_SIN(ifa)->sin_addr; 1647 1648 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1649 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1650 arprequest(ifa->ifa_ifp, ip, ip, 1651 CLLADDR(ifa->ifa_ifp->if_sadl)); 1652 return; 1653 } 1654 if (ifa->ifa_ifp == NULL) 1655 panic("arp_dad_start: ifa->ifa_ifp == NULL"); 1656 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) 1657 return; 1658 if (arp_dad_find(ifa) != NULL) { 1659 /* DAD already in progress */ 1660 return; 1661 } 1662 1663 dp = malloc(sizeof(*dp), M_IPARP, M_NOWAIT); 1664 if (dp == NULL) { 1665 log(LOG_ERR, "arp_dad_start: memory allocation failed for " 1666 "%s(%s)\n", 1667 in_fmtaddr(ia->ia_addr.sin_addr), 1668 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1669 return; 1670 } 1671 memset(dp, 0, sizeof(*dp)); 1672 callout_init(&dp->dad_timer_ch, CALLOUT_MPSAFE); 1673 TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list); 1674 1675 arplog((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1676 in_fmtaddr(ia->ia_addr.sin_addr))); 1677 1678 /* 1679 * Send ARP packet for DAD, ip_dad_count times. 1680 * Note that we must delay the first transmission. 1681 */ 1682 dp->dad_ifa = ifa; 1683 ifaref(ifa); /* just for safety */ 1684 dp->dad_count = ip_dad_count; 1685 dp->dad_arp_announce = 0; /* Will be set when starting to announce */ 1686 dp->dad_arp_acount = dp->dad_arp_ocount = dp->dad_arp_tcount = 0; 1687 1688 arp_dad_starttimer(dp, cprng_fast32() % (PROBE_WAIT * hz)); 1689 } 1690 1691 /* 1692 * terminate DAD unconditionally. used for address removals. 1693 */ 1694 static void 1695 arp_dad_stop(struct ifaddr *ifa) 1696 { 1697 struct dadq *dp; 1698 1699 if (!dad_init) 1700 return; 1701 dp = arp_dad_find(ifa); 1702 if (dp == NULL) { 1703 /* DAD wasn't started yet */ 1704 return; 1705 } 1706 1707 arp_dad_stoptimer(dp); 1708 1709 TAILQ_REMOVE(&dadq, dp, dad_list); 1710 free(dp, M_IPARP); 1711 dp = NULL; 1712 ifafree(ifa); 1713 } 1714 1715 static void 1716 arp_dad_timer(struct ifaddr *ifa) 1717 { 1718 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1719 struct dadq *dp; 1720 struct in_addr *ip; 1721 1722 mutex_enter(softnet_lock); 1723 KERNEL_LOCK(1, NULL); 1724 1725 /* Sanity check */ 1726 if (ia == NULL) { 1727 log(LOG_ERR, "arp_dad_timer: called with null parameter\n"); 1728 goto done; 1729 } 1730 dp = arp_dad_find(ifa); 1731 if (dp == NULL) { 1732 log(LOG_ERR, "arp_dad_timer: DAD structure not found\n"); 1733 goto done; 1734 } 1735 if (ia->ia4_flags & IN_IFF_DUPLICATED) { 1736 log(LOG_ERR, "nd4_dad_timer: called with duplicate address " 1737 "%s(%s)\n", 1738 in_fmtaddr(ia->ia_addr.sin_addr), 1739 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1740 goto done; 1741 } 1742 if ((ia->ia4_flags & IN_IFF_TENTATIVE) == 0 && dp->dad_arp_acount == 0){ 1743 log(LOG_ERR, "arp_dad_timer: called with non-tentative address " 1744 "%s(%s)\n", 1745 in_fmtaddr(ia->ia_addr.sin_addr), 1746 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1747 goto done; 1748 } 1749 1750 /* timeouted with IFF_{RUNNING,UP} check */ 1751 if (dp->dad_arp_tcount > dad_maxtry) { 1752 arplog((LOG_INFO, "%s: could not run DAD, driver problem?\n", 1753 if_name(ifa->ifa_ifp))); 1754 1755 TAILQ_REMOVE(&dadq, dp, dad_list); 1756 free(dp, M_IPARP); 1757 dp = NULL; 1758 ifafree(ifa); 1759 goto done; 1760 } 1761 1762 /* Need more checks? */ 1763 if (dp->dad_arp_ocount < dp->dad_count) { 1764 int adelay; 1765 1766 /* 1767 * We have more ARP to go. Send ARP packet for DAD. 1768 */ 1769 arp_dad_output(dp, ifa); 1770 if (dp->dad_arp_ocount < dp->dad_count) 1771 adelay = (PROBE_MIN * hz) + 1772 (cprng_fast32() % 1773 ((PROBE_MAX * hz) - (PROBE_MIN * hz))); 1774 else 1775 adelay = ANNOUNCE_WAIT * hz; 1776 arp_dad_starttimer(dp, adelay); 1777 goto done; 1778 } else if (dp->dad_arp_acount == 0) { 1779 /* 1780 * We are done with DAD. 1781 * No duplicate address found. 1782 */ 1783 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1784 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1785 arplog((LOG_DEBUG, 1786 "%s: DAD complete for %s - no duplicates found\n", 1787 if_name(ifa->ifa_ifp), 1788 in_fmtaddr(ia->ia_addr.sin_addr))); 1789 dp->dad_arp_announce = ANNOUNCE_NUM; 1790 goto announce; 1791 } else if (dp->dad_arp_acount < dp->dad_arp_announce) { 1792 announce: 1793 /* 1794 * Announce the address. 1795 */ 1796 ip = &IA_SIN(ifa)->sin_addr; 1797 arprequest(ifa->ifa_ifp, ip, ip, 1798 CLLADDR(ifa->ifa_ifp->if_sadl)); 1799 dp->dad_arp_acount++; 1800 if (dp->dad_arp_acount < dp->dad_arp_announce) { 1801 arp_dad_starttimer(dp, ANNOUNCE_INTERVAL * hz); 1802 goto done; 1803 } 1804 arplog((LOG_DEBUG, 1805 "%s: ARP announcement complete for %s\n", 1806 if_name(ifa->ifa_ifp), 1807 in_fmtaddr(ia->ia_addr.sin_addr))); 1808 } 1809 1810 TAILQ_REMOVE(&dadq, dp, dad_list); 1811 free(dp, M_IPARP); 1812 dp = NULL; 1813 ifafree(ifa); 1814 1815 done: 1816 KERNEL_UNLOCK_ONE(NULL); 1817 mutex_exit(softnet_lock); 1818 } 1819 1820 static void 1821 arp_dad_duplicated(struct ifaddr *ifa) 1822 { 1823 struct in_ifaddr *ia = (struct in_ifaddr *)ifa; 1824 struct ifnet *ifp; 1825 struct dadq *dp; 1826 1827 dp = arp_dad_find(ifa); 1828 if (dp == NULL) { 1829 log(LOG_ERR, "arp_dad_duplicated: DAD structure not found\n"); 1830 return; 1831 } 1832 1833 ifp = ifa->ifa_ifp; 1834 log(LOG_ERR, "%s: DAD detected duplicate IPv4 address %s: " 1835 "ARP out=%d\n", 1836 if_name(ifp), in_fmtaddr(ia->ia_addr.sin_addr), 1837 dp->dad_arp_ocount); 1838 1839 ia->ia4_flags &= ~IN_IFF_TENTATIVE; 1840 ia->ia4_flags |= IN_IFF_DUPLICATED; 1841 1842 /* We are done with DAD, with duplicated address found. (failure) */ 1843 arp_dad_stoptimer(dp); 1844 1845 /* Inform the routing socket that DAD has completed */ 1846 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1847 1848 TAILQ_REMOVE(&dadq, dp, dad_list); 1849 free(dp, M_IPARP); 1850 dp = NULL; 1851 ifafree(ifa); 1852 } 1853 1854 /* 1855 * Called from 10 Mb/s Ethernet interrupt handlers 1856 * when ether packet type ETHERTYPE_REVARP 1857 * is received. Common length and type checks are done here, 1858 * then the protocol-specific routine is called. 1859 */ 1860 void 1861 revarpinput(struct mbuf *m) 1862 { 1863 struct arphdr *ar; 1864 1865 if (m->m_len < sizeof(struct arphdr)) 1866 goto out; 1867 ar = mtod(m, struct arphdr *); 1868 #if 0 /* XXX I don't think we need this... and it will prevent other LL */ 1869 if (ntohs(ar->ar_hrd) != ARPHRD_ETHER) 1870 goto out; 1871 #endif 1872 if (m->m_len < sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln)) 1873 goto out; 1874 switch (ntohs(ar->ar_pro)) { 1875 case ETHERTYPE_IP: 1876 case ETHERTYPE_IPTRAILERS: 1877 in_revarpinput(m); 1878 return; 1879 1880 default: 1881 break; 1882 } 1883 out: 1884 m_freem(m); 1885 } 1886 1887 /* 1888 * RARP for Internet protocols on 10 Mb/s Ethernet. 1889 * Algorithm is that given in RFC 903. 1890 * We are only using for bootstrap purposes to get an ip address for one of 1891 * our interfaces. Thus we support no user-interface. 1892 * 1893 * Since the contents of the RARP reply are specific to the interface that 1894 * sent the request, this code must ensure that they are properly associated. 1895 * 1896 * Note: also supports ARP via RARP packets, per the RFC. 1897 */ 1898 void 1899 in_revarpinput(struct mbuf *m) 1900 { 1901 struct ifnet *ifp; 1902 struct arphdr *ah; 1903 void *tha; 1904 int op; 1905 1906 ah = mtod(m, struct arphdr *); 1907 op = ntohs(ah->ar_op); 1908 1909 switch (m->m_pkthdr.rcvif->if_type) { 1910 case IFT_IEEE1394: 1911 /* ARP without target hardware address is not supported */ 1912 goto out; 1913 default: 1914 break; 1915 } 1916 1917 switch (op) { 1918 case ARPOP_REQUEST: 1919 case ARPOP_REPLY: /* per RFC */ 1920 in_arpinput(m); 1921 return; 1922 case ARPOP_REVREPLY: 1923 break; 1924 case ARPOP_REVREQUEST: /* handled by rarpd(8) */ 1925 default: 1926 goto out; 1927 } 1928 if (!revarp_in_progress) 1929 goto out; 1930 ifp = m->m_pkthdr.rcvif; 1931 if (ifp != myip_ifp) /* !same interface */ 1932 goto out; 1933 if (myip_initialized) 1934 goto wake; 1935 tha = ar_tha(ah); 1936 if (tha == NULL) 1937 goto out; 1938 if (memcmp(tha, CLLADDR(ifp->if_sadl), ifp->if_sadl->sdl_alen)) 1939 goto out; 1940 memcpy(&srv_ip, ar_spa(ah), sizeof(srv_ip)); 1941 memcpy(&myip, ar_tpa(ah), sizeof(myip)); 1942 myip_initialized = 1; 1943 wake: /* Do wakeup every time in case it was missed. */ 1944 wakeup((void *)&myip); 1945 1946 out: 1947 m_freem(m); 1948 } 1949 1950 /* 1951 * Send a RARP request for the ip address of the specified interface. 1952 * The request should be RFC 903-compliant. 1953 */ 1954 void 1955 revarprequest(struct ifnet *ifp) 1956 { 1957 struct sockaddr sa; 1958 struct mbuf *m; 1959 struct arphdr *ah; 1960 void *tha; 1961 1962 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 1963 return; 1964 MCLAIM(m, &arpdomain.dom_mowner); 1965 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) + 1966 2*ifp->if_addrlen; 1967 m->m_pkthdr.len = m->m_len; 1968 MH_ALIGN(m, m->m_len); 1969 ah = mtod(m, struct arphdr *); 1970 memset(ah, 0, m->m_len); 1971 ah->ar_pro = htons(ETHERTYPE_IP); 1972 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 1973 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 1974 ah->ar_op = htons(ARPOP_REVREQUEST); 1975 1976 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1977 tha = ar_tha(ah); 1978 if (tha == NULL) { 1979 m_free(m); 1980 return; 1981 } 1982 memcpy(tha, CLLADDR(ifp->if_sadl), ah->ar_hln); 1983 1984 sa.sa_family = AF_ARP; 1985 sa.sa_len = 2; 1986 m->m_flags |= M_BCAST; 1987 1988 KERNEL_LOCK(1, NULL); 1989 (*ifp->if_output)(ifp, m, &sa, NULL); 1990 KERNEL_UNLOCK_ONE(NULL); 1991 } 1992 1993 /* 1994 * RARP for the ip address of the specified interface, but also 1995 * save the ip address of the server that sent the answer. 1996 * Timeout if no response is received. 1997 */ 1998 int 1999 revarpwhoarewe(struct ifnet *ifp, struct in_addr *serv_in, 2000 struct in_addr *clnt_in) 2001 { 2002 int result, count = 20; 2003 2004 myip_initialized = 0; 2005 myip_ifp = ifp; 2006 2007 revarp_in_progress = 1; 2008 while (count--) { 2009 revarprequest(ifp); 2010 result = tsleep((void *)&myip, PSOCK, "revarp", hz/2); 2011 if (result != EWOULDBLOCK) 2012 break; 2013 } 2014 revarp_in_progress = 0; 2015 2016 if (!myip_initialized) 2017 return ENETUNREACH; 2018 2019 memcpy(serv_in, &srv_ip, sizeof(*serv_in)); 2020 memcpy(clnt_in, &myip, sizeof(*clnt_in)); 2021 return 0; 2022 } 2023 2024 2025 2026 #ifdef DDB 2027 2028 #include <machine/db_machdep.h> 2029 #include <ddb/db_interface.h> 2030 #include <ddb/db_output.h> 2031 2032 static void 2033 db_print_sa(const struct sockaddr *sa) 2034 { 2035 int len; 2036 const u_char *p; 2037 2038 if (sa == NULL) { 2039 db_printf("[NULL]"); 2040 return; 2041 } 2042 2043 p = (const u_char *)sa; 2044 len = sa->sa_len; 2045 db_printf("["); 2046 while (len > 0) { 2047 db_printf("%d", *p); 2048 p++; len--; 2049 if (len) db_printf(","); 2050 } 2051 db_printf("]\n"); 2052 } 2053 2054 static void 2055 db_print_ifa(struct ifaddr *ifa) 2056 { 2057 if (ifa == NULL) 2058 return; 2059 db_printf(" ifa_addr="); 2060 db_print_sa(ifa->ifa_addr); 2061 db_printf(" ifa_dsta="); 2062 db_print_sa(ifa->ifa_dstaddr); 2063 db_printf(" ifa_mask="); 2064 db_print_sa(ifa->ifa_netmask); 2065 db_printf(" flags=0x%x,refcnt=%d,metric=%d\n", 2066 ifa->ifa_flags, 2067 ifa->ifa_refcnt, 2068 ifa->ifa_metric); 2069 } 2070 2071 static void 2072 db_print_llinfo(void *li) 2073 { 2074 struct llinfo_arp *la; 2075 2076 if (li == NULL) 2077 return; 2078 la = (struct llinfo_arp *)li; 2079 db_printf(" la_rt=%p la_hold=%p, la_asked=0x%lx\n", 2080 la->la_rt, la->la_hold, la->la_asked); 2081 } 2082 2083 /* 2084 * Function to pass to rt_walktree(). 2085 * Return non-zero error to abort walk. 2086 */ 2087 static int 2088 db_show_rtentry(struct rtentry *rt, void *w) 2089 { 2090 db_printf("rtentry=%p", rt); 2091 2092 db_printf(" flags=0x%x refcnt=%d use=%"PRId64" expire=%"PRId64"\n", 2093 rt->rt_flags, rt->rt_refcnt, 2094 rt->rt_use, (uint64_t)rt->rt_expire); 2095 2096 db_printf(" key="); db_print_sa(rt_getkey(rt)); 2097 db_printf(" mask="); db_print_sa(rt_mask(rt)); 2098 db_printf(" gw="); db_print_sa(rt->rt_gateway); 2099 2100 db_printf(" ifp=%p ", rt->rt_ifp); 2101 if (rt->rt_ifp) 2102 db_printf("(%s)", rt->rt_ifp->if_xname); 2103 else 2104 db_printf("(NULL)"); 2105 2106 db_printf(" ifa=%p\n", rt->rt_ifa); 2107 db_print_ifa(rt->rt_ifa); 2108 2109 db_printf(" gwroute=%p llinfo=%p\n", 2110 rt->rt_gwroute, rt->rt_llinfo); 2111 db_print_llinfo(rt->rt_llinfo); 2112 2113 return 0; 2114 } 2115 2116 /* 2117 * Function to print all the route trees. 2118 * Use this from ddb: "show arptab" 2119 */ 2120 void 2121 db_show_arptab(db_expr_t addr, bool have_addr, 2122 db_expr_t count, const char *modif) 2123 { 2124 rt_walktree(AF_INET, db_show_rtentry, NULL); 2125 } 2126 #endif 2127 2128 void 2129 arp_stat_add(int type, uint64_t count) 2130 { 2131 ARP_STATADD(type, count); 2132 } 2133 2134 static int 2135 sysctl_net_inet_arp_stats(SYSCTLFN_ARGS) 2136 { 2137 2138 return NETSTAT_SYSCTL(arpstat_percpu, ARP_NSTATS); 2139 } 2140 2141 static void 2142 sysctl_net_inet_arp_setup(struct sysctllog **clog) 2143 { 2144 const struct sysctlnode *node; 2145 2146 sysctl_createv(clog, 0, NULL, NULL, 2147 CTLFLAG_PERMANENT, 2148 CTLTYPE_NODE, "inet", NULL, 2149 NULL, 0, NULL, 0, 2150 CTL_NET, PF_INET, CTL_EOL); 2151 sysctl_createv(clog, 0, NULL, &node, 2152 CTLFLAG_PERMANENT, 2153 CTLTYPE_NODE, "arp", 2154 SYSCTL_DESCR("Address Resolution Protocol"), 2155 NULL, 0, NULL, 0, 2156 CTL_NET, PF_INET, CTL_CREATE, CTL_EOL); 2157 2158 sysctl_createv(clog, 0, NULL, NULL, 2159 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2160 CTLTYPE_INT, "keep", 2161 SYSCTL_DESCR("Valid ARP entry lifetime in seconds"), 2162 NULL, 0, &arpt_keep, 0, 2163 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2164 2165 sysctl_createv(clog, 0, NULL, NULL, 2166 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2167 CTLTYPE_INT, "down", 2168 SYSCTL_DESCR("Failed ARP entry lifetime in seconds"), 2169 NULL, 0, &arpt_down, 0, 2170 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2171 2172 sysctl_createv(clog, 0, NULL, NULL, 2173 CTLFLAG_PERMANENT, 2174 CTLTYPE_STRUCT, "stats", 2175 SYSCTL_DESCR("ARP statistics"), 2176 sysctl_net_inet_arp_stats, 0, NULL, 0, 2177 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2178 2179 sysctl_createv(clog, 0, NULL, NULL, 2180 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2181 CTLTYPE_INT, "log_movements", 2182 SYSCTL_DESCR("log ARP replies from MACs different than" 2183 " the one in the cache"), 2184 NULL, 0, &log_movements, 0, 2185 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2186 2187 sysctl_createv(clog, 0, NULL, NULL, 2188 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2189 CTLTYPE_INT, "log_permanent_modify", 2190 SYSCTL_DESCR("log ARP replies from MACs different than" 2191 " the one in the permanent arp entry"), 2192 NULL, 0, &log_permanent_modify, 0, 2193 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2194 2195 sysctl_createv(clog, 0, NULL, NULL, 2196 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2197 CTLTYPE_INT, "log_wrong_iface", 2198 SYSCTL_DESCR("log ARP packets arriving on the wrong" 2199 " interface"), 2200 NULL, 0, &log_wrong_iface, 0, 2201 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2202 2203 sysctl_createv(clog, 0, NULL, NULL, 2204 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2205 CTLTYPE_INT, "log_unknown_network", 2206 SYSCTL_DESCR("log ARP packets from non-local network"), 2207 NULL, 0, &log_unknown_network, 0, 2208 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2209 2210 sysctl_createv(clog, 0, NULL, NULL, 2211 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2212 CTLTYPE_INT, "debug", 2213 SYSCTL_DESCR("Enable ARP DAD debug output"), 2214 NULL, 0, &arp_debug, 0, 2215 CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2216 } 2217 2218 #endif /* INET */ 2219