1 /* $NetBSD: if_arp.c,v 1.144 2008/11/07 00:20:18 dyoung 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 1.144 2008/11/07 00:20:18 dyoung Exp $"); 72 73 #include "opt_ddb.h" 74 #include "opt_inet.h" 75 76 #ifdef INET 77 78 #include "bridge.h" 79 80 #include <sys/param.h> 81 #include <sys/systm.h> 82 #include <sys/callout.h> 83 #include <sys/malloc.h> 84 #include <sys/mbuf.h> 85 #include <sys/socket.h> 86 #include <sys/time.h> 87 #include <sys/timetc.h> 88 #include <sys/kernel.h> 89 #include <sys/errno.h> 90 #include <sys/ioctl.h> 91 #include <sys/syslog.h> 92 #include <sys/proc.h> 93 #include <sys/protosw.h> 94 #include <sys/domain.h> 95 #include <sys/sysctl.h> 96 #include <sys/socketvar.h> 97 #include <sys/percpu.h> 98 99 #include <net/ethertypes.h> 100 #include <net/if.h> 101 #include <net/if_dl.h> 102 #include <net/if_token.h> 103 #include <net/if_types.h> 104 #include <net/if_ether.h> 105 #include <net/route.h> 106 #include <net/net_stats.h> 107 108 #include <netinet/in.h> 109 #include <netinet/in_systm.h> 110 #include <netinet/in_var.h> 111 #include <netinet/ip.h> 112 #include <netinet/if_inarp.h> 113 114 #include "arcnet.h" 115 #if NARCNET > 0 116 #include <net/if_arc.h> 117 #endif 118 #include "fddi.h" 119 #if NFDDI > 0 120 #include <net/if_fddi.h> 121 #endif 122 #include "token.h" 123 #include "carp.h" 124 #if NCARP > 0 125 #include <netinet/ip_carp.h> 126 #endif 127 128 #define SIN(s) ((struct sockaddr_in *)s) 129 #define SRP(s) ((struct sockaddr_inarp *)s) 130 131 /* 132 * ARP trailer negotiation. Trailer protocol is not IP specific, 133 * but ARP request/response use IP addresses. 134 */ 135 #define ETHERTYPE_IPTRAILERS ETHERTYPE_TRAIL 136 137 /* timer values */ 138 int arpt_prune = (5*60*1); /* walk list every 5 minutes */ 139 int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */ 140 int arpt_down = 20; /* once declared down, don't send for 20 secs */ 141 int arpt_refresh = (5*60); /* time left before refreshing */ 142 #define rt_expire rt_rmx.rmx_expire 143 #define rt_pksent rt_rmx.rmx_pksent 144 145 static struct sockaddr *arp_setgate(struct rtentry *, struct sockaddr *, 146 const struct sockaddr *); 147 static void arptfree(struct llinfo_arp *); 148 static void arptimer(void *); 149 static struct llinfo_arp *arplookup1(struct mbuf *, const struct in_addr *, 150 int, int, struct rtentry *); 151 static struct llinfo_arp *arplookup(struct mbuf *, const struct in_addr *, 152 int, int); 153 static void in_arpinput(struct mbuf *); 154 155 LIST_HEAD(, llinfo_arp) llinfo_arp; 156 struct ifqueue arpintrq = { 157 .ifq_head = NULL, 158 .ifq_tail = NULL, 159 .ifq_len = 0, 160 .ifq_maxlen = 50, 161 .ifq_drops = 0, 162 }; 163 int arp_inuse, arp_allocated, arp_intimer; 164 int arp_maxtries = 5; 165 int useloopback = 1; /* use loopback interface for local traffic */ 166 int arpinit_done = 0; 167 168 static percpu_t *arpstat_percpu; 169 170 #define ARP_STAT_GETREF() _NET_STAT_GETREF(arpstat_percpu) 171 #define ARP_STAT_PUTREF() _NET_STAT_PUTREF(arpstat_percpu) 172 173 #define ARP_STATINC(x) _NET_STATINC(arpstat_percpu, x) 174 #define ARP_STATADD(x, v) _NET_STATADD(arpstat_percpu, x, v) 175 176 struct callout arptimer_ch; 177 178 /* revarp state */ 179 struct in_addr myip, srv_ip; 180 int myip_initialized = 0; 181 int revarp_in_progress = 0; 182 struct ifnet *myip_ifp = NULL; 183 184 #ifdef DDB 185 static void db_print_sa(const struct sockaddr *); 186 static void db_print_ifa(struct ifaddr *); 187 static void db_print_llinfo(void *); 188 static int db_show_rtentry(struct rtentry *, void *); 189 #endif 190 191 /* 192 * this should be elsewhere. 193 */ 194 195 static char * 196 lla_snprintf(u_int8_t *, int); 197 198 static char * 199 lla_snprintf(u_int8_t *adrp, int len) 200 { 201 #define NUMBUFS 3 202 static char buf[NUMBUFS][16*3]; 203 static int bnum = 0; 204 205 int i; 206 char *p; 207 208 p = buf[bnum]; 209 210 *p++ = hexdigits[(*adrp)>>4]; 211 *p++ = hexdigits[(*adrp++)&0xf]; 212 213 for (i=1; i<len && i<16; i++) { 214 *p++ = ':'; 215 *p++ = hexdigits[(*adrp)>>4]; 216 *p++ = hexdigits[(*adrp++)&0xf]; 217 } 218 219 *p = 0; 220 p = buf[bnum]; 221 bnum = (bnum + 1) % NUMBUFS; 222 return p; 223 } 224 225 DOMAIN_DEFINE(arpdomain); /* forward declare and add to link set */ 226 227 const struct protosw arpsw[] = { 228 { .pr_type = 0, 229 .pr_domain = &arpdomain, 230 .pr_protocol = 0, 231 .pr_flags = 0, 232 .pr_input = 0, 233 .pr_output = 0, 234 .pr_ctlinput = 0, 235 .pr_ctloutput = 0, 236 .pr_usrreq = 0, 237 .pr_init = arp_init, 238 .pr_fasttimo = 0, 239 .pr_slowtimo = 0, 240 .pr_drain = arp_drain, 241 } 242 }; 243 244 245 struct domain arpdomain = { 246 .dom_family = PF_ARP, 247 .dom_name = "arp", 248 .dom_protosw = arpsw, 249 .dom_protoswNPROTOSW = &arpsw[__arraycount(arpsw)], 250 }; 251 252 /* 253 * ARP table locking. 254 * 255 * to prevent lossage vs. the arp_drain routine (which may be called at 256 * any time, including in a device driver context), we do two things: 257 * 258 * 1) manipulation of la->la_hold is done at splnet() (for all of 259 * about two instructions). 260 * 261 * 2) manipulation of the arp table's linked list is done under the 262 * protection of the ARP_LOCK; if arp_drain() or arptimer is called 263 * while the arp table is locked, we punt and try again later. 264 */ 265 266 static int arp_locked; 267 static inline int arp_lock_try(int); 268 static inline void arp_unlock(void); 269 270 static inline int 271 arp_lock_try(int recurse) 272 { 273 int s; 274 275 /* 276 * Use splvm() -- we're blocking things that would cause 277 * mbuf allocation. 278 */ 279 s = splvm(); 280 if (!recurse && arp_locked) { 281 splx(s); 282 return 0; 283 } 284 arp_locked++; 285 splx(s); 286 return 1; 287 } 288 289 static inline void 290 arp_unlock(void) 291 { 292 int s; 293 294 s = splvm(); 295 arp_locked--; 296 splx(s); 297 } 298 299 #ifdef DIAGNOSTIC 300 #define ARP_LOCK(recurse) \ 301 do { \ 302 if (arp_lock_try(recurse) == 0) { \ 303 printf("%s:%d: arp already locked\n", __FILE__, __LINE__); \ 304 panic("arp_lock"); \ 305 } \ 306 } while (/*CONSTCOND*/ 0) 307 #define ARP_LOCK_CHECK() \ 308 do { \ 309 if (arp_locked == 0) { \ 310 printf("%s:%d: arp lock not held\n", __FILE__, __LINE__); \ 311 panic("arp lock check"); \ 312 } \ 313 } while (/*CONSTCOND*/ 0) 314 #else 315 #define ARP_LOCK(x) (void) arp_lock_try(x) 316 #define ARP_LOCK_CHECK() /* nothing */ 317 #endif 318 319 #define ARP_UNLOCK() arp_unlock() 320 321 void 322 arp_init(void) 323 { 324 325 arpstat_percpu = percpu_alloc(sizeof(uint64_t) * ARP_NSTATS); 326 } 327 328 /* 329 * ARP protocol drain routine. Called when memory is in short supply. 330 * Called at splvm(); don't acquire softnet_lock as can be called from 331 * hardware interrupt handlers. 332 */ 333 void 334 arp_drain(void) 335 { 336 struct llinfo_arp *la, *nla; 337 int count = 0; 338 struct mbuf *mold; 339 340 KERNEL_LOCK(1, NULL); 341 342 if (arp_lock_try(0) == 0) { 343 KERNEL_UNLOCK_ONE(NULL); 344 return; 345 } 346 347 for (la = LIST_FIRST(&llinfo_arp); la != NULL; la = nla) { 348 nla = LIST_NEXT(la, la_list); 349 350 mold = la->la_hold; 351 la->la_hold = 0; 352 353 if (mold) { 354 m_freem(mold); 355 count++; 356 } 357 } 358 ARP_UNLOCK(); 359 ARP_STATADD(ARP_STAT_DFRDROPPED, count); 360 KERNEL_UNLOCK_ONE(NULL); 361 } 362 363 364 /* 365 * Timeout routine. Age arp_tab entries periodically. 366 */ 367 /* ARGSUSED */ 368 static void 369 arptimer(void *arg) 370 { 371 struct llinfo_arp *la, *nla; 372 373 mutex_enter(softnet_lock); 374 KERNEL_LOCK(1, NULL); 375 376 if (arp_lock_try(0) == 0) { 377 /* get it later.. */ 378 KERNEL_UNLOCK_ONE(NULL); 379 mutex_exit(softnet_lock); 380 return; 381 } 382 383 callout_reset(&arptimer_ch, arpt_prune * hz, arptimer, NULL); 384 for (la = LIST_FIRST(&llinfo_arp); la != NULL; la = nla) { 385 struct rtentry *rt = la->la_rt; 386 387 nla = LIST_NEXT(la, la_list); 388 if (rt->rt_expire == 0) 389 continue; 390 if ((rt->rt_expire - time_second) < arpt_refresh && 391 rt->rt_pksent > (time_second - arpt_keep)) { 392 /* 393 * If the entry has been used during since last 394 * refresh, try to renew it before deleting. 395 */ 396 arprequest(rt->rt_ifp, 397 &satocsin(rt->rt_ifa->ifa_addr)->sin_addr, 398 &satocsin(rt_getkey(rt))->sin_addr, 399 CLLADDR(rt->rt_ifp->if_sadl)); 400 } else if (rt->rt_expire <= time_second) 401 arptfree(la); /* timer has expired; clear */ 402 } 403 404 ARP_UNLOCK(); 405 406 KERNEL_UNLOCK_ONE(NULL); 407 mutex_exit(softnet_lock); 408 } 409 410 /* 411 * We set the gateway for RTF_CLONING routes to a "prototype" 412 * link-layer sockaddr whose interface type (if_type) and interface 413 * index (if_index) fields are prepared. 414 */ 415 static struct sockaddr * 416 arp_setgate(struct rtentry *rt, struct sockaddr *gate, 417 const struct sockaddr *netmask) 418 { 419 const struct ifnet *ifp = rt->rt_ifp; 420 uint8_t namelen = strlen(ifp->if_xname); 421 uint8_t addrlen = ifp->if_addrlen; 422 423 /* 424 * XXX: If this is a manually added route to interface 425 * such as older version of routed or gated might provide, 426 * restore cloning bit. 427 */ 428 if ((rt->rt_flags & RTF_HOST) == 0 && netmask != NULL && 429 satocsin(netmask)->sin_addr.s_addr != 0xffffffff) 430 rt->rt_flags |= RTF_CLONING; 431 if (rt->rt_flags & RTF_CLONING) { 432 union { 433 struct sockaddr sa; 434 struct sockaddr_storage ss; 435 struct sockaddr_dl sdl; 436 } u; 437 /* 438 * Case 1: This route should come from a route to iface. 439 */ 440 sockaddr_dl_init(&u.sdl, sizeof(u.ss), 441 ifp->if_index, ifp->if_type, NULL, namelen, NULL, addrlen); 442 rt_setgate(rt, &u.sa); 443 gate = rt->rt_gateway; 444 } 445 return gate; 446 } 447 448 /* 449 * Parallel to llc_rtrequest. 450 */ 451 void 452 arp_rtrequest(int req, struct rtentry *rt, const struct rt_addrinfo *info) 453 { 454 struct sockaddr *gate = rt->rt_gateway; 455 struct llinfo_arp *la = (struct llinfo_arp *)rt->rt_llinfo; 456 size_t allocsize; 457 struct mbuf *mold; 458 int s; 459 struct in_ifaddr *ia; 460 struct ifaddr *ifa; 461 struct ifnet *ifp = rt->rt_ifp; 462 uint8_t namelen = strlen(ifp->if_xname); 463 uint8_t addrlen = ifp->if_addrlen; 464 465 if (!arpinit_done) { 466 arpinit_done = 1; 467 /* 468 * We generate expiration times from time_second 469 * so avoid accidentally creating permanent routes. 470 */ 471 if (time_second == 0) { 472 struct timespec ts; 473 ts.tv_sec = 1; 474 ts.tv_nsec = 0; 475 tc_setclock(&ts); 476 } 477 callout_init(&arptimer_ch, CALLOUT_MPSAFE); 478 callout_reset(&arptimer_ch, hz, arptimer, NULL); 479 } 480 481 if (req == RTM_LLINFO_UPD) { 482 struct in_addr *in; 483 484 if ((ifa = info->rti_ifa) == NULL) 485 return; 486 487 in = &ifatoia(ifa)->ia_addr.sin_addr; 488 489 arprequest(ifa->ifa_ifp, in, in, 490 CLLADDR(ifa->ifa_ifp->if_sadl)); 491 return; 492 } 493 494 if ((rt->rt_flags & RTF_GATEWAY) != 0) { 495 if (req != RTM_ADD) 496 return; 497 498 /* 499 * linklayers with particular link MTU limitation. 500 */ 501 switch(ifp->if_type) { 502 #if NFDDI > 0 503 case IFT_FDDI: 504 if (ifp->if_mtu > FDDIIPMTU) 505 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 506 break; 507 #endif 508 #if NARC > 0 509 case IFT_ARCNET: 510 { 511 int arcipifmtu; 512 513 if (ifp->if_flags & IFF_LINK0) 514 arcipifmtu = arc_ipmtu; 515 else 516 arcipifmtu = ARCMTU; 517 if (ifp->if_mtu > arcipifmtu) 518 rt->rt_rmx.rmx_mtu = arcipifmtu; 519 break; 520 } 521 #endif 522 } 523 return; 524 } 525 526 ARP_LOCK(1); /* we may already be locked here. */ 527 528 switch (req) { 529 case RTM_SETGATE: 530 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 531 break; 532 case RTM_ADD: 533 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 534 if (rt->rt_flags & RTF_CLONING) { 535 /* 536 * Give this route an expiration time, even though 537 * it's a "permanent" route, so that routes cloned 538 * from it do not need their expiration time set. 539 */ 540 rt->rt_expire = time_second; 541 /* 542 * linklayers with particular link MTU limitation. 543 */ 544 switch (ifp->if_type) { 545 #if NFDDI > 0 546 case IFT_FDDI: 547 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 548 (rt->rt_rmx.rmx_mtu > FDDIIPMTU || 549 (rt->rt_rmx.rmx_mtu == 0 && 550 ifp->if_mtu > FDDIIPMTU))) 551 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 552 break; 553 #endif 554 #if NARC > 0 555 case IFT_ARCNET: 556 { 557 int arcipifmtu; 558 if (ifp->if_flags & IFF_LINK0) 559 arcipifmtu = arc_ipmtu; 560 else 561 arcipifmtu = ARCMTU; 562 563 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 564 (rt->rt_rmx.rmx_mtu > arcipifmtu || 565 (rt->rt_rmx.rmx_mtu == 0 && 566 ifp->if_mtu > arcipifmtu))) 567 rt->rt_rmx.rmx_mtu = arcipifmtu; 568 break; 569 } 570 #endif 571 } 572 break; 573 } 574 /* Announce a new entry if requested. */ 575 if (rt->rt_flags & RTF_ANNOUNCE) 576 arprequest(ifp, 577 &satocsin(rt_getkey(rt))->sin_addr, 578 &satocsin(rt_getkey(rt))->sin_addr, 579 CLLADDR(satocsdl(gate))); 580 /*FALLTHROUGH*/ 581 case RTM_RESOLVE: 582 if (gate->sa_family != AF_LINK || 583 gate->sa_len < sockaddr_dl_measure(namelen, addrlen)) { 584 log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n"); 585 break; 586 } 587 satosdl(gate)->sdl_type = ifp->if_type; 588 satosdl(gate)->sdl_index = ifp->if_index; 589 if (la != NULL) 590 break; /* This happens on a route change */ 591 /* 592 * Case 2: This route may come from cloning, or a manual route 593 * add with a LL address. 594 */ 595 switch (satocsdl(gate)->sdl_type) { 596 #if NTOKEN > 0 597 case IFT_ISO88025: 598 allocsize = sizeof(*la) + sizeof(struct token_rif); 599 break; 600 #endif /* NTOKEN > 0 */ 601 default: 602 allocsize = sizeof(*la); 603 } 604 R_Malloc(la, struct llinfo_arp *, allocsize); 605 rt->rt_llinfo = (void *)la; 606 if (la == NULL) { 607 log(LOG_DEBUG, "arp_rtrequest: malloc failed\n"); 608 break; 609 } 610 arp_inuse++, arp_allocated++; 611 memset(la, 0, allocsize); 612 la->la_rt = rt; 613 rt->rt_flags |= RTF_LLINFO; 614 LIST_INSERT_HEAD(&llinfo_arp, la, la_list); 615 616 INADDR_TO_IA(satocsin(rt_getkey(rt))->sin_addr, ia); 617 while (ia && ia->ia_ifp != ifp) 618 NEXT_IA_WITH_SAME_ADDR(ia); 619 if (ia) { 620 /* 621 * This test used to be 622 * if (lo0ifp->if_flags & IFF_UP) 623 * It allowed local traffic to be forced through 624 * the hardware by configuring the loopback down. 625 * However, it causes problems during network 626 * configuration for boards that can't receive 627 * packets they send. It is now necessary to clear 628 * "useloopback" and remove the route to force 629 * traffic out to the hardware. 630 * 631 * In 4.4BSD, the above "if" statement checked 632 * rt->rt_ifa against rt_getkey(rt). It was changed 633 * to the current form so that we can provide a 634 * better support for multiple IPv4 addresses on a 635 * interface. 636 */ 637 rt->rt_expire = 0; 638 (void)sockaddr_dl_setaddr(satosdl(gate), gate->sa_len, 639 CLLADDR(ifp->if_sadl), ifp->if_addrlen); 640 if (useloopback) 641 ifp = rt->rt_ifp = lo0ifp; 642 /* 643 * make sure to set rt->rt_ifa to the interface 644 * address we are using, otherwise we will have trouble 645 * with source address selection. 646 */ 647 ifa = &ia->ia_ifa; 648 if (ifa != rt->rt_ifa) 649 rt_replace_ifa(rt, ifa); 650 } 651 break; 652 653 case RTM_DELETE: 654 if (la == NULL) 655 break; 656 arp_inuse--; 657 LIST_REMOVE(la, la_list); 658 rt->rt_llinfo = NULL; 659 rt->rt_flags &= ~RTF_LLINFO; 660 661 s = splnet(); 662 mold = la->la_hold; 663 la->la_hold = 0; 664 splx(s); 665 666 if (mold) 667 m_freem(mold); 668 669 Free((void *)la); 670 } 671 ARP_UNLOCK(); 672 } 673 674 /* 675 * Broadcast an ARP request. Caller specifies: 676 * - arp header source ip address 677 * - arp header target ip address 678 * - arp header source ethernet address 679 */ 680 void 681 arprequest(struct ifnet *ifp, 682 const struct in_addr *sip, const struct in_addr *tip, 683 const u_int8_t *enaddr) 684 { 685 struct mbuf *m; 686 struct arphdr *ah; 687 struct sockaddr sa; 688 uint64_t *arps; 689 690 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 691 return; 692 MCLAIM(m, &arpdomain.dom_mowner); 693 switch (ifp->if_type) { 694 case IFT_IEEE1394: 695 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 696 ifp->if_addrlen; 697 break; 698 default: 699 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 700 2 * ifp->if_addrlen; 701 break; 702 } 703 m->m_pkthdr.len = m->m_len; 704 MH_ALIGN(m, m->m_len); 705 ah = mtod(m, struct arphdr *); 706 memset(ah, 0, m->m_len); 707 switch (ifp->if_type) { 708 case IFT_IEEE1394: /* RFC2734 */ 709 /* fill it now for ar_tpa computation */ 710 ah->ar_hrd = htons(ARPHRD_IEEE1394); 711 break; 712 default: 713 /* ifp->if_output will fill ar_hrd */ 714 break; 715 } 716 ah->ar_pro = htons(ETHERTYPE_IP); 717 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 718 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 719 ah->ar_op = htons(ARPOP_REQUEST); 720 memcpy(ar_sha(ah), enaddr, ah->ar_hln); 721 memcpy(ar_spa(ah), sip, ah->ar_pln); 722 memcpy(ar_tpa(ah), tip, ah->ar_pln); 723 sa.sa_family = AF_ARP; 724 sa.sa_len = 2; 725 m->m_flags |= M_BCAST; 726 arps = ARP_STAT_GETREF(); 727 arps[ARP_STAT_SNDTOTAL]++; 728 arps[ARP_STAT_SENDREQUEST]++; 729 ARP_STAT_PUTREF(); 730 (*ifp->if_output)(ifp, m, &sa, NULL); 731 } 732 733 /* 734 * Resolve an IP address into an ethernet address. If success, 735 * desten is filled in. If there is no entry in arptab, 736 * set one up and broadcast a request for the IP address. 737 * Hold onto this mbuf and resend it once the address 738 * is finally resolved. A return value of 1 indicates 739 * that desten has been filled in and the packet should be sent 740 * normally; a 0 return indicates that the packet has been 741 * taken over here, either now or for later transmission. 742 */ 743 int 744 arpresolve(struct ifnet *ifp, struct rtentry *rt, struct mbuf *m, 745 const struct sockaddr *dst, u_char *desten) 746 { 747 struct llinfo_arp *la; 748 const struct sockaddr_dl *sdl; 749 struct mbuf *mold; 750 int s; 751 752 if ((la = arplookup1(m, &satocsin(dst)->sin_addr, 1, 0, rt)) != NULL) 753 rt = la->la_rt; 754 755 if (la == NULL || rt == NULL) { 756 ARP_STATINC(ARP_STAT_ALLOCFAIL); 757 log(LOG_DEBUG, 758 "arpresolve: can't allocate llinfo on %s for %s\n", 759 ifp->if_xname, in_fmtaddr(satocsin(dst)->sin_addr)); 760 m_freem(m); 761 return 0; 762 } 763 sdl = satocsdl(rt->rt_gateway); 764 /* 765 * Check the address family and length is valid, the address 766 * is resolved; otherwise, try to resolve. 767 */ 768 if ((rt->rt_expire == 0 || rt->rt_expire > time_second) && 769 sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) { 770 memcpy(desten, CLLADDR(sdl), 771 min(sdl->sdl_alen, ifp->if_addrlen)); 772 rt->rt_pksent = time_second; /* Time for last pkt sent */ 773 return 1; 774 } 775 /* 776 * There is an arptab entry, but no ethernet address 777 * response yet. Replace the held mbuf with this 778 * latest one. 779 */ 780 781 ARP_STATINC(ARP_STAT_DFRTOTAL); 782 s = splnet(); 783 mold = la->la_hold; 784 la->la_hold = m; 785 splx(s); 786 787 if (mold) { 788 ARP_STATINC(ARP_STAT_DFRDROPPED); 789 m_freem(mold); 790 } 791 792 /* 793 * Re-send the ARP request when appropriate. 794 */ 795 #ifdef DIAGNOSTIC 796 if (rt->rt_expire == 0) { 797 /* This should never happen. (Should it? -gwr) */ 798 printf("arpresolve: unresolved and rt_expire == 0\n"); 799 /* Set expiration time to now (expired). */ 800 rt->rt_expire = time_second; 801 } 802 #endif 803 if (rt->rt_expire) { 804 rt->rt_flags &= ~RTF_REJECT; 805 if (la->la_asked == 0 || rt->rt_expire != time_second) { 806 rt->rt_expire = time_second; 807 if (la->la_asked++ < arp_maxtries) 808 arprequest(ifp, 809 &satocsin(rt->rt_ifa->ifa_addr)->sin_addr, 810 &satocsin(dst)->sin_addr, 811 #if NCARP > 0 812 (rt->rt_ifp->if_type == IFT_CARP) ? 813 CLLADDR(rt->rt_ifp->if_sadl): 814 #endif 815 CLLADDR(ifp->if_sadl)); 816 else { 817 rt->rt_flags |= RTF_REJECT; 818 rt->rt_expire += arpt_down; 819 la->la_asked = 0; 820 } 821 } 822 } 823 return 0; 824 } 825 826 /* 827 * Common length and type checks are done here, 828 * then the protocol-specific routine is called. 829 */ 830 void 831 arpintr(void) 832 { 833 struct mbuf *m; 834 struct arphdr *ar; 835 int s; 836 int arplen; 837 838 mutex_enter(softnet_lock); 839 KERNEL_LOCK(1, NULL); 840 while (arpintrq.ifq_head) { 841 s = splnet(); 842 IF_DEQUEUE(&arpintrq, m); 843 splx(s); 844 if (m == 0 || (m->m_flags & M_PKTHDR) == 0) 845 panic("arpintr"); 846 847 MCLAIM(m, &arpdomain.dom_mowner); 848 ARP_STATINC(ARP_STAT_RCVTOTAL); 849 850 /* 851 * First, make sure we have at least struct arphdr. 852 */ 853 if (m->m_len < sizeof(struct arphdr) || 854 (ar = mtod(m, struct arphdr *)) == NULL) 855 goto badlen; 856 857 switch (m->m_pkthdr.rcvif->if_type) { 858 case IFT_IEEE1394: 859 arplen = sizeof(struct arphdr) + 860 ar->ar_hln + 2 * ar->ar_pln; 861 break; 862 default: 863 arplen = sizeof(struct arphdr) + 864 2 * ar->ar_hln + 2 * ar->ar_pln; 865 break; 866 } 867 868 if (/* XXX ntohs(ar->ar_hrd) == ARPHRD_ETHER && */ 869 m->m_len >= arplen) 870 switch (ntohs(ar->ar_pro)) { 871 case ETHERTYPE_IP: 872 case ETHERTYPE_IPTRAILERS: 873 in_arpinput(m); 874 continue; 875 default: 876 ARP_STATINC(ARP_STAT_RCVBADPROTO); 877 } 878 else { 879 badlen: 880 ARP_STATINC(ARP_STAT_RCVBADLEN); 881 } 882 m_freem(m); 883 } 884 KERNEL_UNLOCK_ONE(NULL); 885 mutex_exit(softnet_lock); 886 } 887 888 /* 889 * ARP for Internet protocols on 10 Mb/s Ethernet. 890 * Algorithm is that given in RFC 826. 891 * In addition, a sanity check is performed on the sender 892 * protocol address, to catch impersonators. 893 * We no longer handle negotiations for use of trailer protocol: 894 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent 895 * along with IP replies if we wanted trailers sent to us, 896 * and also sent them in response to IP replies. 897 * This allowed either end to announce the desire to receive 898 * trailer packets. 899 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, 900 * but formerly didn't normally send requests. 901 */ 902 static void 903 in_arpinput(struct mbuf *m) 904 { 905 struct arphdr *ah; 906 struct ifnet *ifp = m->m_pkthdr.rcvif; 907 struct llinfo_arp *la = NULL; 908 struct rtentry *rt; 909 struct in_ifaddr *ia; 910 #if NBRIDGE > 0 911 struct in_ifaddr *bridge_ia = NULL; 912 #endif 913 #if NCARP > 0 914 u_int32_t count = 0, index = 0; 915 #endif 916 struct sockaddr_dl *sdl; 917 struct sockaddr sa; 918 struct in_addr isaddr, itaddr, myaddr; 919 int op; 920 struct mbuf *mold; 921 void *tha; 922 int s; 923 uint64_t *arps; 924 925 if (__predict_false(m_makewritable(&m, 0, m->m_pkthdr.len, M_DONTWAIT))) 926 goto out; 927 ah = mtod(m, struct arphdr *); 928 op = ntohs(ah->ar_op); 929 930 /* 931 * Fix up ah->ar_hrd if necessary, before using ar_tha() or 932 * ar_tpa(). 933 */ 934 switch (ifp->if_type) { 935 case IFT_IEEE1394: 936 if (ntohs(ah->ar_hrd) == ARPHRD_IEEE1394) 937 ; 938 else { 939 /* XXX this is to make sure we compute ar_tha right */ 940 /* XXX check ar_hrd more strictly? */ 941 ah->ar_hrd = htons(ARPHRD_IEEE1394); 942 } 943 break; 944 default: 945 /* XXX check ar_hrd? */ 946 break; 947 } 948 949 memcpy(&isaddr, ar_spa(ah), sizeof (isaddr)); 950 memcpy(&itaddr, ar_tpa(ah), sizeof (itaddr)); 951 952 if (m->m_flags & (M_BCAST|M_MCAST)) 953 ARP_STATINC(ARP_STAT_RCVMCAST); 954 955 /* 956 * If the target IP address is zero, ignore the packet. 957 * This prevents the code below from tring to answer 958 * when we are using IP address zero (booting). 959 */ 960 if (in_nullhost(itaddr)) { 961 ARP_STATINC(ARP_STAT_RCVZEROTPA); 962 goto out; 963 } 964 965 /* 966 * If the source IP address is zero, this is most likely a 967 * confused host trying to use IP address zero. (Windoze?) 968 * XXX: Should we bother trying to reply to these? 969 */ 970 if (in_nullhost(isaddr)) { 971 ARP_STATINC(ARP_STAT_RCVZEROSPA); 972 goto out; 973 } 974 975 /* 976 * Search for a matching interface address 977 * or any address on the interface to use 978 * as a dummy address in the rest of this function 979 */ 980 981 INADDR_TO_IA(itaddr, ia); 982 while (ia != NULL) { 983 #if NCARP > 0 984 if (ia->ia_ifp->if_type == IFT_CARP && 985 ((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) == 986 (IFF_UP|IFF_RUNNING))) { 987 index++; 988 if (ia->ia_ifp == m->m_pkthdr.rcvif && 989 carp_iamatch(ia, ar_sha(ah), 990 &count, index)) { 991 break; 992 } 993 } else 994 #endif 995 if (ia->ia_ifp == m->m_pkthdr.rcvif) 996 break; 997 #if NBRIDGE > 0 998 /* 999 * If the interface we received the packet on 1000 * is part of a bridge, check to see if we need 1001 * to "bridge" the packet to ourselves at this 1002 * layer. Note we still prefer a perfect match, 1003 * but allow this weaker match if necessary. 1004 */ 1005 if (m->m_pkthdr.rcvif->if_bridge != NULL && 1006 m->m_pkthdr.rcvif->if_bridge == ia->ia_ifp->if_bridge) 1007 bridge_ia = ia; 1008 #endif /* NBRIDGE > 0 */ 1009 1010 NEXT_IA_WITH_SAME_ADDR(ia); 1011 } 1012 1013 #if NBRIDGE > 0 1014 if (ia == NULL && bridge_ia != NULL) { 1015 ia = bridge_ia; 1016 ifp = bridge_ia->ia_ifp; 1017 } 1018 #endif 1019 1020 if (ia == NULL) { 1021 INADDR_TO_IA(isaddr, ia); 1022 while ((ia != NULL) && ia->ia_ifp != m->m_pkthdr.rcvif) 1023 NEXT_IA_WITH_SAME_ADDR(ia); 1024 1025 if (ia == NULL) { 1026 IFP_TO_IA(ifp, ia); 1027 if (ia == NULL) { 1028 ARP_STATINC(ARP_STAT_RCVNOINT); 1029 goto out; 1030 } 1031 } 1032 } 1033 1034 myaddr = ia->ia_addr.sin_addr; 1035 1036 /* XXX checks for bridge case? */ 1037 if (!memcmp(ar_sha(ah), CLLADDR(ifp->if_sadl), ifp->if_addrlen)) { 1038 ARP_STATINC(ARP_STAT_RCVLOCALSHA); 1039 goto out; /* it's from me, ignore it. */ 1040 } 1041 1042 /* XXX checks for bridge case? */ 1043 if (!memcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 1044 ARP_STATINC(ARP_STAT_RCVBCASTSHA); 1045 log(LOG_ERR, 1046 "%s: arp: link address is broadcast for IP address %s!\n", 1047 ifp->if_xname, in_fmtaddr(isaddr)); 1048 goto out; 1049 } 1050 1051 if (in_hosteq(isaddr, myaddr)) { 1052 ARP_STATINC(ARP_STAT_RCVLOCALSPA); 1053 log(LOG_ERR, 1054 "duplicate IP address %s sent from link address %s\n", 1055 in_fmtaddr(isaddr), lla_snprintf(ar_sha(ah), ah->ar_hln)); 1056 itaddr = myaddr; 1057 goto reply; 1058 } 1059 la = arplookup(m, &isaddr, in_hosteq(itaddr, myaddr), 0); 1060 if (la != NULL && (rt = la->la_rt) && (sdl = satosdl(rt->rt_gateway))) { 1061 if (sdl->sdl_alen && 1062 memcmp(ar_sha(ah), CLLADDR(sdl), sdl->sdl_alen)) { 1063 if (rt->rt_flags & RTF_STATIC) { 1064 ARP_STATINC(ARP_STAT_RCVOVERPERM); 1065 log(LOG_INFO, 1066 "%s tried to overwrite permanent arp info" 1067 " for %s\n", 1068 lla_snprintf(ar_sha(ah), ah->ar_hln), 1069 in_fmtaddr(isaddr)); 1070 goto out; 1071 } else if (rt->rt_ifp != ifp) { 1072 ARP_STATINC(ARP_STAT_RCVOVERINT); 1073 log(LOG_INFO, 1074 "%s on %s tried to overwrite " 1075 "arp info for %s on %s\n", 1076 lla_snprintf(ar_sha(ah), ah->ar_hln), 1077 ifp->if_xname, in_fmtaddr(isaddr), 1078 rt->rt_ifp->if_xname); 1079 goto out; 1080 } else { 1081 ARP_STATINC(ARP_STAT_RCVOVER); 1082 log(LOG_INFO, 1083 "arp info overwritten for %s by %s\n", 1084 in_fmtaddr(isaddr), 1085 lla_snprintf(ar_sha(ah), ah->ar_hln)); 1086 } 1087 } 1088 /* 1089 * sanity check for the address length. 1090 * XXX this does not work for protocols with variable address 1091 * length. -is 1092 */ 1093 if (sdl->sdl_alen && 1094 sdl->sdl_alen != ah->ar_hln) { 1095 ARP_STATINC(ARP_STAT_RCVLENCHG); 1096 log(LOG_WARNING, 1097 "arp from %s: new addr len %d, was %d\n", 1098 in_fmtaddr(isaddr), ah->ar_hln, sdl->sdl_alen); 1099 } 1100 if (ifp->if_addrlen != ah->ar_hln) { 1101 ARP_STATINC(ARP_STAT_RCVBADLEN); 1102 log(LOG_WARNING, 1103 "arp from %s: addr len: new %d, i/f %d (ignored)\n", 1104 in_fmtaddr(isaddr), ah->ar_hln, 1105 ifp->if_addrlen); 1106 goto reply; 1107 } 1108 #if NTOKEN > 0 1109 /* 1110 * XXX uses m_data and assumes the complete answer including 1111 * XXX token-ring headers is in the same buf 1112 */ 1113 if (ifp->if_type == IFT_ISO88025) { 1114 struct token_header *trh; 1115 1116 trh = (struct token_header *)M_TRHSTART(m); 1117 if (trh->token_shost[0] & TOKEN_RI_PRESENT) { 1118 struct token_rif *rif; 1119 size_t riflen; 1120 1121 rif = TOKEN_RIF(trh); 1122 riflen = (ntohs(rif->tr_rcf) & 1123 TOKEN_RCF_LEN_MASK) >> 8; 1124 1125 if (riflen > 2 && 1126 riflen < sizeof(struct token_rif) && 1127 (riflen & 1) == 0) { 1128 rif->tr_rcf ^= htons(TOKEN_RCF_DIRECTION); 1129 rif->tr_rcf &= htons(~TOKEN_RCF_BROADCAST_MASK); 1130 memcpy(TOKEN_RIF(la), rif, riflen); 1131 } 1132 } 1133 } 1134 #endif /* NTOKEN > 0 */ 1135 (void)sockaddr_dl_setaddr(sdl, sdl->sdl_len, ar_sha(ah), 1136 ah->ar_hln); 1137 if (rt->rt_expire) 1138 rt->rt_expire = time_second + arpt_keep; 1139 rt->rt_flags &= ~RTF_REJECT; 1140 la->la_asked = 0; 1141 1142 s = splnet(); 1143 mold = la->la_hold; 1144 la->la_hold = 0; 1145 splx(s); 1146 1147 if (mold) { 1148 ARP_STATINC(ARP_STAT_DFRSENT); 1149 (*ifp->if_output)(ifp, mold, rt_getkey(rt), rt); 1150 } 1151 } 1152 reply: 1153 if (op != ARPOP_REQUEST) { 1154 if (op == ARPOP_REPLY) 1155 ARP_STATINC(ARP_STAT_RCVREPLY); 1156 out: 1157 m_freem(m); 1158 return; 1159 } 1160 ARP_STATINC(ARP_STAT_RCVREQUEST); 1161 if (in_hosteq(itaddr, myaddr)) { 1162 /* I am the target */ 1163 tha = ar_tha(ah); 1164 if (tha) 1165 memcpy(tha, ar_sha(ah), ah->ar_hln); 1166 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1167 } else { 1168 la = arplookup(m, &itaddr, 0, SIN_PROXY); 1169 if (la == NULL) 1170 goto out; 1171 rt = la->la_rt; 1172 if (rt->rt_ifp->if_type == IFT_CARP && 1173 m->m_pkthdr.rcvif->if_type != IFT_CARP) 1174 goto out; 1175 tha = ar_tha(ah); 1176 if (tha) 1177 memcpy(tha, ar_sha(ah), ah->ar_hln); 1178 sdl = satosdl(rt->rt_gateway); 1179 memcpy(ar_sha(ah), CLLADDR(sdl), ah->ar_hln); 1180 } 1181 1182 memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); 1183 memcpy(ar_spa(ah), &itaddr, ah->ar_pln); 1184 ah->ar_op = htons(ARPOP_REPLY); 1185 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 1186 switch (ifp->if_type) { 1187 case IFT_IEEE1394: 1188 /* 1189 * ieee1394 arp reply is broadcast 1190 */ 1191 m->m_flags &= ~M_MCAST; 1192 m->m_flags |= M_BCAST; 1193 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + ah->ar_hln; 1194 break; 1195 1196 default: 1197 m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */ 1198 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); 1199 break; 1200 } 1201 m->m_pkthdr.len = m->m_len; 1202 sa.sa_family = AF_ARP; 1203 sa.sa_len = 2; 1204 arps = ARP_STAT_GETREF(); 1205 arps[ARP_STAT_SNDTOTAL]++; 1206 arps[ARP_STAT_SNDREPLY]++; 1207 ARP_STAT_PUTREF(); 1208 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); 1209 return; 1210 } 1211 1212 /* 1213 * Free an arp entry. 1214 */ 1215 static void arptfree(struct llinfo_arp *la) 1216 { 1217 struct rtentry *rt = la->la_rt; 1218 struct sockaddr_dl *sdl; 1219 1220 ARP_LOCK_CHECK(); 1221 1222 if (rt == NULL) 1223 panic("arptfree"); 1224 if (rt->rt_refcnt > 0 && (sdl = satosdl(rt->rt_gateway)) && 1225 sdl->sdl_family == AF_LINK) { 1226 sdl->sdl_alen = 0; 1227 la->la_asked = 0; 1228 rt->rt_flags &= ~RTF_REJECT; 1229 return; 1230 } 1231 rtrequest(RTM_DELETE, rt_getkey(rt), NULL, rt_mask(rt), 0, NULL); 1232 } 1233 1234 static struct llinfo_arp * 1235 arplookup(struct mbuf *m, const struct in_addr *addr, int create, int proxy) 1236 { 1237 return arplookup1(m, addr, create, proxy, NULL); 1238 } 1239 1240 /* 1241 * Lookup or enter a new address in arptab. 1242 */ 1243 static struct llinfo_arp * 1244 arplookup1(struct mbuf *m, const struct in_addr *addr, int create, int proxy, 1245 struct rtentry *rt0) 1246 { 1247 struct arphdr *ah; 1248 struct ifnet *ifp = m->m_pkthdr.rcvif; 1249 struct rtentry *rt; 1250 struct sockaddr_inarp sin; 1251 const char *why = NULL; 1252 1253 ah = mtod(m, struct arphdr *); 1254 if (rt0 == NULL) { 1255 memset(&sin, 0, sizeof(sin)); 1256 sin.sin_len = sizeof(sin); 1257 sin.sin_family = AF_INET; 1258 sin.sin_addr = *addr; 1259 sin.sin_other = proxy ? SIN_PROXY : 0; 1260 rt = rtalloc1(sintosa(&sin), create); 1261 if (rt == NULL) 1262 return NULL; 1263 rt->rt_refcnt--; 1264 } else 1265 rt = rt0; 1266 1267 #define IS_LLINFO(__rt) \ 1268 (((__rt)->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) == RTF_LLINFO && \ 1269 (__rt)->rt_gateway->sa_family == AF_LINK) 1270 1271 1272 if (IS_LLINFO(rt)) 1273 return (struct llinfo_arp *)rt->rt_llinfo; 1274 1275 if (create) { 1276 if (rt->rt_flags & RTF_GATEWAY) 1277 why = "host is not on local network"; 1278 else if ((rt->rt_flags & RTF_LLINFO) == 0) { 1279 ARP_STATINC(ARP_STAT_ALLOCFAIL); 1280 why = "could not allocate llinfo"; 1281 } else 1282 why = "gateway route is not ours"; 1283 log(LOG_DEBUG, "arplookup: unable to enter address" 1284 " for %s@%s on %s (%s)\n", 1285 in_fmtaddr(*addr), lla_snprintf(ar_sha(ah), ah->ar_hln), 1286 (ifp) ? ifp->if_xname : "null", why); 1287 if (rt->rt_refcnt <= 0 && (rt->rt_flags & RTF_CLONED) != 0) { 1288 rtrequest(RTM_DELETE, rt_getkey(rt), 1289 rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL); 1290 } 1291 } 1292 return NULL; 1293 } 1294 1295 int 1296 arpioctl(u_long cmd, void *data) 1297 { 1298 1299 return EOPNOTSUPP; 1300 } 1301 1302 void 1303 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1304 { 1305 struct in_addr *ip; 1306 1307 /* 1308 * Warn the user if another station has this IP address, 1309 * but only if the interface IP address is not zero. 1310 */ 1311 ip = &IA_SIN(ifa)->sin_addr; 1312 if (!in_nullhost(*ip)) 1313 arprequest(ifp, ip, ip, CLLADDR(ifp->if_sadl)); 1314 1315 ifa->ifa_rtrequest = arp_rtrequest; 1316 ifa->ifa_flags |= RTF_CLONING; 1317 } 1318 1319 /* 1320 * Called from 10 Mb/s Ethernet interrupt handlers 1321 * when ether packet type ETHERTYPE_REVARP 1322 * is received. Common length and type checks are done here, 1323 * then the protocol-specific routine is called. 1324 */ 1325 void 1326 revarpinput(struct mbuf *m) 1327 { 1328 struct arphdr *ar; 1329 1330 if (m->m_len < sizeof(struct arphdr)) 1331 goto out; 1332 ar = mtod(m, struct arphdr *); 1333 #if 0 /* XXX I don't think we need this... and it will prevent other LL */ 1334 if (ntohs(ar->ar_hrd) != ARPHRD_ETHER) 1335 goto out; 1336 #endif 1337 if (m->m_len < sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln)) 1338 goto out; 1339 switch (ntohs(ar->ar_pro)) { 1340 case ETHERTYPE_IP: 1341 case ETHERTYPE_IPTRAILERS: 1342 in_revarpinput(m); 1343 return; 1344 1345 default: 1346 break; 1347 } 1348 out: 1349 m_freem(m); 1350 } 1351 1352 /* 1353 * RARP for Internet protocols on 10 Mb/s Ethernet. 1354 * Algorithm is that given in RFC 903. 1355 * We are only using for bootstrap purposes to get an ip address for one of 1356 * our interfaces. Thus we support no user-interface. 1357 * 1358 * Since the contents of the RARP reply are specific to the interface that 1359 * sent the request, this code must ensure that they are properly associated. 1360 * 1361 * Note: also supports ARP via RARP packets, per the RFC. 1362 */ 1363 void 1364 in_revarpinput(struct mbuf *m) 1365 { 1366 struct ifnet *ifp; 1367 struct arphdr *ah; 1368 void *tha; 1369 int op; 1370 1371 ah = mtod(m, struct arphdr *); 1372 op = ntohs(ah->ar_op); 1373 1374 switch (m->m_pkthdr.rcvif->if_type) { 1375 case IFT_IEEE1394: 1376 /* ARP without target hardware address is not supported */ 1377 goto out; 1378 default: 1379 break; 1380 } 1381 1382 switch (op) { 1383 case ARPOP_REQUEST: 1384 case ARPOP_REPLY: /* per RFC */ 1385 in_arpinput(m); 1386 return; 1387 case ARPOP_REVREPLY: 1388 break; 1389 case ARPOP_REVREQUEST: /* handled by rarpd(8) */ 1390 default: 1391 goto out; 1392 } 1393 if (!revarp_in_progress) 1394 goto out; 1395 ifp = m->m_pkthdr.rcvif; 1396 if (ifp != myip_ifp) /* !same interface */ 1397 goto out; 1398 if (myip_initialized) 1399 goto wake; 1400 tha = ar_tha(ah); 1401 KASSERT(tha); 1402 if (memcmp(tha, CLLADDR(ifp->if_sadl), ifp->if_sadl->sdl_alen)) 1403 goto out; 1404 memcpy(&srv_ip, ar_spa(ah), sizeof(srv_ip)); 1405 memcpy(&myip, ar_tpa(ah), sizeof(myip)); 1406 myip_initialized = 1; 1407 wake: /* Do wakeup every time in case it was missed. */ 1408 wakeup((void *)&myip); 1409 1410 out: 1411 m_freem(m); 1412 } 1413 1414 /* 1415 * Send a RARP request for the ip address of the specified interface. 1416 * The request should be RFC 903-compliant. 1417 */ 1418 void 1419 revarprequest(struct ifnet *ifp) 1420 { 1421 struct sockaddr sa; 1422 struct mbuf *m; 1423 struct arphdr *ah; 1424 void *tha; 1425 1426 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 1427 return; 1428 MCLAIM(m, &arpdomain.dom_mowner); 1429 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) + 1430 2*ifp->if_addrlen; 1431 m->m_pkthdr.len = m->m_len; 1432 MH_ALIGN(m, m->m_len); 1433 ah = mtod(m, struct arphdr *); 1434 memset(ah, 0, m->m_len); 1435 ah->ar_pro = htons(ETHERTYPE_IP); 1436 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 1437 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 1438 ah->ar_op = htons(ARPOP_REVREQUEST); 1439 1440 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1441 tha = ar_tha(ah); 1442 KASSERT(tha); 1443 memcpy(tha, CLLADDR(ifp->if_sadl), ah->ar_hln); 1444 1445 sa.sa_family = AF_ARP; 1446 sa.sa_len = 2; 1447 m->m_flags |= M_BCAST; 1448 (*ifp->if_output)(ifp, m, &sa, NULL); 1449 1450 } 1451 1452 /* 1453 * RARP for the ip address of the specified interface, but also 1454 * save the ip address of the server that sent the answer. 1455 * Timeout if no response is received. 1456 */ 1457 int 1458 revarpwhoarewe(struct ifnet *ifp, struct in_addr *serv_in, 1459 struct in_addr *clnt_in) 1460 { 1461 int result, count = 20; 1462 1463 myip_initialized = 0; 1464 myip_ifp = ifp; 1465 1466 revarp_in_progress = 1; 1467 while (count--) { 1468 revarprequest(ifp); 1469 result = tsleep((void *)&myip, PSOCK, "revarp", hz/2); 1470 if (result != EWOULDBLOCK) 1471 break; 1472 } 1473 revarp_in_progress = 0; 1474 1475 if (!myip_initialized) 1476 return ENETUNREACH; 1477 1478 memcpy(serv_in, &srv_ip, sizeof(*serv_in)); 1479 memcpy(clnt_in, &myip, sizeof(*clnt_in)); 1480 return 0; 1481 } 1482 1483 1484 1485 #ifdef DDB 1486 1487 #include <machine/db_machdep.h> 1488 #include <ddb/db_interface.h> 1489 #include <ddb/db_output.h> 1490 1491 static void 1492 db_print_sa(const struct sockaddr *sa) 1493 { 1494 int len; 1495 const u_char *p; 1496 1497 if (sa == NULL) { 1498 db_printf("[NULL]"); 1499 return; 1500 } 1501 1502 p = (const u_char *)sa; 1503 len = sa->sa_len; 1504 db_printf("["); 1505 while (len > 0) { 1506 db_printf("%d", *p); 1507 p++; len--; 1508 if (len) db_printf(","); 1509 } 1510 db_printf("]\n"); 1511 } 1512 1513 static void 1514 db_print_ifa(struct ifaddr *ifa) 1515 { 1516 if (ifa == NULL) 1517 return; 1518 db_printf(" ifa_addr="); 1519 db_print_sa(ifa->ifa_addr); 1520 db_printf(" ifa_dsta="); 1521 db_print_sa(ifa->ifa_dstaddr); 1522 db_printf(" ifa_mask="); 1523 db_print_sa(ifa->ifa_netmask); 1524 db_printf(" flags=0x%x,refcnt=%d,metric=%d\n", 1525 ifa->ifa_flags, 1526 ifa->ifa_refcnt, 1527 ifa->ifa_metric); 1528 } 1529 1530 static void 1531 db_print_llinfo(void *li) 1532 { 1533 struct llinfo_arp *la; 1534 1535 if (li == NULL) 1536 return; 1537 la = (struct llinfo_arp *)li; 1538 db_printf(" la_rt=%p la_hold=%p, la_asked=0x%lx\n", 1539 la->la_rt, la->la_hold, la->la_asked); 1540 } 1541 1542 /* 1543 * Function to pass to rt_walktree(). 1544 * Return non-zero error to abort walk. 1545 */ 1546 static int 1547 db_show_rtentry(struct rtentry *rt, void *w) 1548 { 1549 db_printf("rtentry=%p", rt); 1550 1551 db_printf(" flags=0x%x refcnt=%d use=%ld expire=%ld\n", 1552 rt->rt_flags, rt->rt_refcnt, 1553 rt->rt_use, rt->rt_expire); 1554 1555 db_printf(" key="); db_print_sa(rt_getkey(rt)); 1556 db_printf(" mask="); db_print_sa(rt_mask(rt)); 1557 db_printf(" gw="); db_print_sa(rt->rt_gateway); 1558 1559 db_printf(" ifp=%p ", rt->rt_ifp); 1560 if (rt->rt_ifp) 1561 db_printf("(%s)", rt->rt_ifp->if_xname); 1562 else 1563 db_printf("(NULL)"); 1564 1565 db_printf(" ifa=%p\n", rt->rt_ifa); 1566 db_print_ifa(rt->rt_ifa); 1567 1568 db_printf(" gwroute=%p llinfo=%p\n", 1569 rt->rt_gwroute, rt->rt_llinfo); 1570 db_print_llinfo(rt->rt_llinfo); 1571 1572 return 0; 1573 } 1574 1575 /* 1576 * Function to print all the route trees. 1577 * Use this from ddb: "show arptab" 1578 */ 1579 void 1580 db_show_arptab(db_expr_t addr, bool have_addr, 1581 db_expr_t count, const char *modif) 1582 { 1583 rt_walktree(AF_INET, db_show_rtentry, NULL); 1584 } 1585 #endif 1586 1587 static int 1588 sysctl_net_inet_arp_stats(SYSCTLFN_ARGS) 1589 { 1590 1591 return NETSTAT_SYSCTL(arpstat_percpu, ARP_NSTATS); 1592 } 1593 1594 SYSCTL_SETUP(sysctl_net_inet_arp_setup, "sysctl net.inet.arp subtree setup") 1595 { 1596 const struct sysctlnode *node; 1597 1598 sysctl_createv(clog, 0, NULL, NULL, 1599 CTLFLAG_PERMANENT, 1600 CTLTYPE_NODE, "net", NULL, 1601 NULL, 0, NULL, 0, 1602 CTL_NET, CTL_EOL); 1603 sysctl_createv(clog, 0, NULL, NULL, 1604 CTLFLAG_PERMANENT, 1605 CTLTYPE_NODE, "inet", NULL, 1606 NULL, 0, NULL, 0, 1607 CTL_NET, PF_INET, CTL_EOL); 1608 sysctl_createv(clog, 0, NULL, &node, 1609 CTLFLAG_PERMANENT, 1610 CTLTYPE_NODE, "arp", 1611 SYSCTL_DESCR("Address Resolution Protocol"), 1612 NULL, 0, NULL, 0, 1613 CTL_NET, PF_INET, CTL_CREATE, CTL_EOL); 1614 1615 sysctl_createv(clog, 0, NULL, NULL, 1616 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1617 CTLTYPE_INT, "prune", 1618 SYSCTL_DESCR("ARP cache pruning interval"), 1619 NULL, 0, &arpt_prune, 0, 1620 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1621 1622 sysctl_createv(clog, 0, NULL, NULL, 1623 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1624 CTLTYPE_INT, "keep", 1625 SYSCTL_DESCR("Valid ARP entry lifetime"), 1626 NULL, 0, &arpt_keep, 0, 1627 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1628 1629 sysctl_createv(clog, 0, NULL, NULL, 1630 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1631 CTLTYPE_INT, "down", 1632 SYSCTL_DESCR("Failed ARP entry lifetime"), 1633 NULL, 0, &arpt_down, 0, 1634 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1635 1636 sysctl_createv(clog, 0, NULL, NULL, 1637 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1638 CTLTYPE_INT, "refresh", 1639 SYSCTL_DESCR("ARP entry refresh interval"), 1640 NULL, 0, &arpt_refresh, 0, 1641 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1642 1643 sysctl_createv(clog, 0, NULL, NULL, 1644 CTLFLAG_PERMANENT, 1645 CTLTYPE_STRUCT, "stats", 1646 SYSCTL_DESCR("ARP statistics"), 1647 sysctl_net_inet_arp_stats, 0, NULL, 0, 1648 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1649 } 1650 1651 #endif /* INET */ 1652