1 /* $NetBSD: if_arp.c,v 1.134 2008/04/24 11:38:37 ad 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 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 /* 41 * Copyright (c) 1982, 1986, 1988, 1993 42 * The Regents of the University of California. All rights reserved. 43 * 44 * Redistribution and use in source and binary forms, with or without 45 * modification, are permitted provided that the following conditions 46 * are met: 47 * 1. Redistributions of source code must retain the above copyright 48 * notice, this list of conditions and the following disclaimer. 49 * 2. Redistributions in binary form must reproduce the above copyright 50 * notice, this list of conditions and the following disclaimer in the 51 * documentation and/or other materials provided with the distribution. 52 * 3. Neither the name of the University nor the names of its contributors 53 * may be used to endorse or promote products derived from this software 54 * without specific prior written permission. 55 * 56 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 57 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 58 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 59 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 60 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 61 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 62 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 63 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 64 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 65 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 66 * SUCH DAMAGE. 67 * 68 * @(#)if_ether.c 8.2 (Berkeley) 9/26/94 69 */ 70 71 /* 72 * Ethernet address resolution protocol. 73 * TODO: 74 * add "inuse/lock" bit (or ref. count) along with valid bit 75 */ 76 77 #include <sys/cdefs.h> 78 __KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.134 2008/04/24 11:38:37 ad Exp $"); 79 80 #include "opt_ddb.h" 81 #include "opt_inet.h" 82 83 #ifdef INET 84 85 #include "bridge.h" 86 87 #include <sys/param.h> 88 #include <sys/systm.h> 89 #include <sys/callout.h> 90 #include <sys/malloc.h> 91 #include <sys/mbuf.h> 92 #include <sys/socket.h> 93 #include <sys/time.h> 94 #include <sys/timetc.h> 95 #include <sys/kernel.h> 96 #include <sys/errno.h> 97 #include <sys/ioctl.h> 98 #include <sys/syslog.h> 99 #include <sys/proc.h> 100 #include <sys/protosw.h> 101 #include <sys/domain.h> 102 #include <sys/sysctl.h> 103 #include <sys/socketvar.h> 104 #include <sys/percpu.h> 105 106 #include <net/ethertypes.h> 107 #include <net/if.h> 108 #include <net/if_dl.h> 109 #include <net/if_token.h> 110 #include <net/if_types.h> 111 #include <net/if_ether.h> 112 #include <net/route.h> 113 #include <net/net_stats.h> 114 115 #include <netinet/in.h> 116 #include <netinet/in_systm.h> 117 #include <netinet/in_var.h> 118 #include <netinet/ip.h> 119 #include <netinet/if_inarp.h> 120 121 #include "arcnet.h" 122 #if NARCNET > 0 123 #include <net/if_arc.h> 124 #endif 125 #include "fddi.h" 126 #if NFDDI > 0 127 #include <net/if_fddi.h> 128 #endif 129 #include "token.h" 130 #include "carp.h" 131 #if NCARP > 0 132 #include <netinet/ip_carp.h> 133 #endif 134 135 #define SIN(s) ((struct sockaddr_in *)s) 136 #define SRP(s) ((struct sockaddr_inarp *)s) 137 138 /* 139 * ARP trailer negotiation. Trailer protocol is not IP specific, 140 * but ARP request/response use IP addresses. 141 */ 142 #define ETHERTYPE_IPTRAILERS ETHERTYPE_TRAIL 143 144 /* timer values */ 145 int arpt_prune = (5*60*1); /* walk list every 5 minutes */ 146 int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */ 147 int arpt_down = 20; /* once declared down, don't send for 20 secs */ 148 int arpt_refresh = (5*60); /* time left before refreshing */ 149 #define rt_expire rt_rmx.rmx_expire 150 #define rt_pksent rt_rmx.rmx_pksent 151 152 static struct sockaddr *arp_setgate(struct rtentry *, struct sockaddr *, 153 const struct sockaddr *); 154 static void arptfree(struct llinfo_arp *); 155 static void arptimer(void *); 156 static struct llinfo_arp *arplookup1(struct mbuf *, const struct in_addr *, 157 int, int, struct rtentry *); 158 static struct llinfo_arp *arplookup(struct mbuf *, const struct in_addr *, 159 int, int); 160 static void in_arpinput(struct mbuf *); 161 162 LIST_HEAD(, llinfo_arp) llinfo_arp; 163 struct ifqueue arpintrq = { 164 .ifq_head = NULL, 165 .ifq_tail = NULL, 166 .ifq_len = 0, 167 .ifq_maxlen = 50, 168 .ifq_drops = 0, 169 }; 170 int arp_inuse, arp_allocated, arp_intimer; 171 int arp_maxtries = 5; 172 int useloopback = 1; /* use loopback interface for local traffic */ 173 int arpinit_done = 0; 174 175 static percpu_t *arpstat_percpu; 176 177 #define ARP_STAT_GETREF() _NET_STAT_GETREF(arpstat_percpu) 178 #define ARP_STAT_PUTREF() _NET_STAT_PUTREF(arpstat_percpu) 179 180 #define ARP_STATINC(x) _NET_STATINC(arpstat_percpu, x) 181 #define ARP_STATADD(x, v) _NET_STATADD(arpstat_percpu, x, v) 182 183 struct callout arptimer_ch; 184 185 /* revarp state */ 186 struct in_addr myip, srv_ip; 187 int myip_initialized = 0; 188 int revarp_in_progress = 0; 189 struct ifnet *myip_ifp = NULL; 190 191 #ifdef DDB 192 static void db_print_sa(const struct sockaddr *); 193 static void db_print_ifa(struct ifaddr *); 194 static void db_print_llinfo(void *); 195 static int db_show_rtentry(struct rtentry *, void *); 196 #endif 197 198 /* 199 * this should be elsewhere. 200 */ 201 202 static char * 203 lla_snprintf(u_int8_t *, int); 204 205 static char * 206 lla_snprintf(u_int8_t *adrp, int len) 207 { 208 #define NUMBUFS 3 209 static char buf[NUMBUFS][16*3]; 210 static int bnum = 0; 211 212 int i; 213 char *p; 214 215 p = buf[bnum]; 216 217 *p++ = hexdigits[(*adrp)>>4]; 218 *p++ = hexdigits[(*adrp++)&0xf]; 219 220 for (i=1; i<len && i<16; i++) { 221 *p++ = ':'; 222 *p++ = hexdigits[(*adrp)>>4]; 223 *p++ = hexdigits[(*adrp++)&0xf]; 224 } 225 226 *p = 0; 227 p = buf[bnum]; 228 bnum = (bnum + 1) % NUMBUFS; 229 return p; 230 } 231 232 DOMAIN_DEFINE(arpdomain); /* forward declare and add to link set */ 233 234 const struct protosw arpsw[] = { 235 { .pr_type = 0, 236 .pr_domain = &arpdomain, 237 .pr_protocol = 0, 238 .pr_flags = 0, 239 .pr_input = 0, 240 .pr_output = 0, 241 .pr_ctlinput = 0, 242 .pr_ctloutput = 0, 243 .pr_usrreq = 0, 244 .pr_init = arp_init, 245 .pr_fasttimo = 0, 246 .pr_slowtimo = 0, 247 .pr_drain = arp_drain, 248 } 249 }; 250 251 252 struct domain arpdomain = { 253 .dom_family = PF_ARP, 254 .dom_name = "arp", 255 .dom_protosw = arpsw, 256 .dom_protoswNPROTOSW = &arpsw[sizeof(arpsw)/sizeof(arpsw[0])], 257 }; 258 259 /* 260 * ARP table locking. 261 * 262 * to prevent lossage vs. the arp_drain routine (which may be called at 263 * any time, including in a device driver context), we do two things: 264 * 265 * 1) manipulation of la->la_hold is done at splnet() (for all of 266 * about two instructions). 267 * 268 * 2) manipulation of the arp table's linked list is done under the 269 * protection of the ARP_LOCK; if arp_drain() or arptimer is called 270 * while the arp table is locked, we punt and try again later. 271 */ 272 273 static int arp_locked; 274 static inline int arp_lock_try(int); 275 static inline void arp_unlock(void); 276 277 static inline int 278 arp_lock_try(int recurse) 279 { 280 int s; 281 282 /* 283 * Use splvm() -- we're blocking things that would cause 284 * mbuf allocation. 285 */ 286 s = splvm(); 287 if (!recurse && arp_locked) { 288 splx(s); 289 return (0); 290 } 291 arp_locked++; 292 splx(s); 293 return (1); 294 } 295 296 static inline void 297 arp_unlock(void) 298 { 299 int s; 300 301 s = splvm(); 302 arp_locked--; 303 splx(s); 304 } 305 306 #ifdef DIAGNOSTIC 307 #define ARP_LOCK(recurse) \ 308 do { \ 309 if (arp_lock_try(recurse) == 0) { \ 310 printf("%s:%d: arp already locked\n", __FILE__, __LINE__); \ 311 panic("arp_lock"); \ 312 } \ 313 } while (/*CONSTCOND*/ 0) 314 #define ARP_LOCK_CHECK() \ 315 do { \ 316 if (arp_locked == 0) { \ 317 printf("%s:%d: arp lock not held\n", __FILE__, __LINE__); \ 318 panic("arp lock check"); \ 319 } \ 320 } while (/*CONSTCOND*/ 0) 321 #else 322 #define ARP_LOCK(x) (void) arp_lock_try(x) 323 #define ARP_LOCK_CHECK() /* nothing */ 324 #endif 325 326 #define ARP_UNLOCK() arp_unlock() 327 328 void 329 arp_init(void) 330 { 331 332 arpstat_percpu = percpu_alloc(sizeof(uint64_t) * ARP_NSTATS); 333 } 334 335 /* 336 * ARP protocol drain routine. Called when memory is in short supply. 337 * Called at splvm(); 338 */ 339 void 340 arp_drain(void) 341 { 342 struct llinfo_arp *la, *nla; 343 int count = 0; 344 struct mbuf *mold; 345 346 mutex_enter(softnet_lock); 347 KERNEL_LOCK(1, NULL); 348 349 if (arp_lock_try(0) == 0) { 350 printf("arp_drain: locked; punting\n"); 351 KERNEL_UNLOCK_ONE(NULL); 352 mutex_exit(softnet_lock); 353 return; 354 } 355 356 for (la = LIST_FIRST(&llinfo_arp); la != 0; la = nla) { 357 nla = LIST_NEXT(la, la_list); 358 359 mold = la->la_hold; 360 la->la_hold = 0; 361 362 if (mold) { 363 m_freem(mold); 364 count++; 365 } 366 } 367 ARP_UNLOCK(); 368 ARP_STATADD(ARP_STAT_DFRDROPPED, count); 369 KERNEL_UNLOCK_ONE(NULL); 370 mutex_exit(softnet_lock); 371 } 372 373 374 /* 375 * Timeout routine. Age arp_tab entries periodically. 376 */ 377 /* ARGSUSED */ 378 static void 379 arptimer(void *arg) 380 { 381 struct llinfo_arp *la, *nla; 382 383 mutex_enter(softnet_lock); 384 KERNEL_LOCK(1, NULL); 385 386 if (arp_lock_try(0) == 0) { 387 /* get it later.. */ 388 KERNEL_UNLOCK_ONE(NULL); 389 mutex_exit(softnet_lock); 390 return; 391 } 392 393 callout_reset(&arptimer_ch, arpt_prune * hz, arptimer, NULL); 394 for (la = LIST_FIRST(&llinfo_arp); la != 0; la = nla) { 395 struct rtentry *rt = la->la_rt; 396 397 nla = LIST_NEXT(la, la_list); 398 if (rt->rt_expire == 0) 399 continue; 400 if ((rt->rt_expire - time_second) < arpt_refresh && 401 rt->rt_pksent > (time_second - arpt_keep)) { 402 /* 403 * If the entry has been used during since last 404 * refresh, try to renew it before deleting. 405 */ 406 arprequest(rt->rt_ifp, 407 &satocsin(rt->rt_ifa->ifa_addr)->sin_addr, 408 &satocsin(rt_getkey(rt))->sin_addr, 409 CLLADDR(rt->rt_ifp->if_sadl)); 410 } else if (rt->rt_expire <= time_second) 411 arptfree(la); /* timer has expired; clear */ 412 } 413 414 ARP_UNLOCK(); 415 416 KERNEL_UNLOCK_ONE(NULL); 417 mutex_exit(softnet_lock); 418 } 419 420 /* 421 * We set the gateway for RTF_CLONING routes to a "prototype" 422 * link-layer sockaddr whose interface type (if_type) and interface 423 * index (if_index) fields are prepared. 424 */ 425 static struct sockaddr * 426 arp_setgate(struct rtentry *rt, struct sockaddr *gate, 427 const struct sockaddr *netmask) 428 { 429 const struct ifnet *ifp = rt->rt_ifp; 430 uint8_t namelen = strlen(ifp->if_xname); 431 uint8_t addrlen = ifp->if_addrlen; 432 433 /* 434 * XXX: If this is a manually added route to interface 435 * such as older version of routed or gated might provide, 436 * restore cloning bit. 437 */ 438 if ((rt->rt_flags & RTF_HOST) == 0 && netmask != NULL && 439 satocsin(netmask)->sin_addr.s_addr != 0xffffffff) 440 rt->rt_flags |= RTF_CLONING; 441 if (rt->rt_flags & RTF_CLONING) { 442 union { 443 struct sockaddr sa; 444 struct sockaddr_storage ss; 445 struct sockaddr_dl sdl; 446 } u; 447 /* 448 * Case 1: This route should come from a route to iface. 449 */ 450 sockaddr_dl_init(&u.sdl, sizeof(u.ss), 451 ifp->if_index, ifp->if_type, NULL, namelen, NULL, addrlen); 452 rt_setgate(rt, &u.sa); 453 gate = rt->rt_gateway; 454 } 455 return gate; 456 } 457 458 /* 459 * Parallel to llc_rtrequest. 460 */ 461 void 462 arp_rtrequest(int req, struct rtentry *rt, struct rt_addrinfo *info) 463 { 464 struct sockaddr *gate = rt->rt_gateway; 465 struct llinfo_arp *la = (struct llinfo_arp *)rt->rt_llinfo; 466 size_t allocsize; 467 struct mbuf *mold; 468 int s; 469 struct in_ifaddr *ia; 470 struct ifaddr *ifa; 471 struct ifnet *ifp = rt->rt_ifp; 472 uint8_t namelen = strlen(ifp->if_xname); 473 uint8_t addrlen = ifp->if_addrlen; 474 475 if (!arpinit_done) { 476 arpinit_done = 1; 477 /* 478 * We generate expiration times from time_second 479 * so avoid accidentally creating permanent routes. 480 */ 481 if (time_second == 0) { 482 struct timespec ts; 483 ts.tv_sec = 1; 484 ts.tv_nsec = 0; 485 tc_setclock(&ts); 486 } 487 callout_init(&arptimer_ch, CALLOUT_MPSAFE); 488 callout_reset(&arptimer_ch, hz, arptimer, NULL); 489 } 490 491 if ((rt->rt_flags & RTF_GATEWAY) != 0) { 492 if (req != RTM_ADD) 493 return; 494 495 /* 496 * linklayers with particular link MTU limitation. 497 */ 498 switch(ifp->if_type) { 499 #if NFDDI > 0 500 case IFT_FDDI: 501 if (ifp->if_mtu > FDDIIPMTU) 502 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 503 break; 504 #endif 505 #if NARC > 0 506 case IFT_ARCNET: 507 { 508 int arcipifmtu; 509 510 if (ifp->if_flags & IFF_LINK0) 511 arcipifmtu = arc_ipmtu; 512 else 513 arcipifmtu = ARCMTU; 514 if (ifp->if_mtu > arcipifmtu) 515 rt->rt_rmx.rmx_mtu = arcipifmtu; 516 break; 517 } 518 #endif 519 } 520 return; 521 } 522 523 ARP_LOCK(1); /* we may already be locked here. */ 524 525 switch (req) { 526 527 case RTM_SETGATE: 528 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 529 break; 530 case RTM_ADD: 531 gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]); 532 if (rt->rt_flags & RTF_CLONING) { 533 /* 534 * Give this route an expiration time, even though 535 * it's a "permanent" route, so that routes cloned 536 * from it do not need their expiration time set. 537 */ 538 rt->rt_expire = time_second; 539 /* 540 * linklayers with particular link MTU limitation. 541 */ 542 switch (ifp->if_type) { 543 #if NFDDI > 0 544 case IFT_FDDI: 545 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 546 (rt->rt_rmx.rmx_mtu > FDDIIPMTU || 547 (rt->rt_rmx.rmx_mtu == 0 && 548 ifp->if_mtu > FDDIIPMTU))) 549 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 550 break; 551 #endif 552 #if NARC > 0 553 case IFT_ARCNET: 554 { 555 int arcipifmtu; 556 if (ifp->if_flags & IFF_LINK0) 557 arcipifmtu = arc_ipmtu; 558 else 559 arcipifmtu = ARCMTU; 560 561 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 562 (rt->rt_rmx.rmx_mtu > arcipifmtu || 563 (rt->rt_rmx.rmx_mtu == 0 && 564 ifp->if_mtu > arcipifmtu))) 565 rt->rt_rmx.rmx_mtu = arcipifmtu; 566 break; 567 } 568 #endif 569 } 570 break; 571 } 572 /* Announce a new entry if requested. */ 573 if (rt->rt_flags & RTF_ANNOUNCE) 574 arprequest(ifp, 575 &satocsin(rt_getkey(rt))->sin_addr, 576 &satocsin(rt_getkey(rt))->sin_addr, 577 CLLADDR(satocsdl(gate))); 578 /*FALLTHROUGH*/ 579 case RTM_RESOLVE: 580 if (gate->sa_family != AF_LINK || 581 gate->sa_len < sockaddr_dl_measure(namelen, addrlen)) { 582 log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n"); 583 break; 584 } 585 satosdl(gate)->sdl_type = ifp->if_type; 586 satosdl(gate)->sdl_index = ifp->if_index; 587 if (la != 0) 588 break; /* This happens on a route change */ 589 /* 590 * Case 2: This route may come from cloning, or a manual route 591 * add with a LL address. 592 */ 593 switch (satocsdl(gate)->sdl_type) { 594 #if NTOKEN > 0 595 case IFT_ISO88025: 596 allocsize = sizeof(*la) + sizeof(struct token_rif); 597 break; 598 #endif /* NTOKEN > 0 */ 599 default: 600 allocsize = sizeof(*la); 601 } 602 R_Malloc(la, struct llinfo_arp *, allocsize); 603 rt->rt_llinfo = (void *)la; 604 if (la == 0) { 605 log(LOG_DEBUG, "arp_rtrequest: malloc failed\n"); 606 break; 607 } 608 arp_inuse++, arp_allocated++; 609 Bzero(la, allocsize); 610 la->la_rt = rt; 611 rt->rt_flags |= RTF_LLINFO; 612 LIST_INSERT_HEAD(&llinfo_arp, la, la_list); 613 614 INADDR_TO_IA(satocsin(rt_getkey(rt))->sin_addr, ia); 615 while (ia && ia->ia_ifp != ifp) 616 NEXT_IA_WITH_SAME_ADDR(ia); 617 if (ia) { 618 /* 619 * This test used to be 620 * if (lo0ifp->if_flags & IFF_UP) 621 * It allowed local traffic to be forced through 622 * the hardware by configuring the loopback down. 623 * However, it causes problems during network 624 * configuration for boards that can't receive 625 * packets they send. It is now necessary to clear 626 * "useloopback" and remove the route to force 627 * traffic out to the hardware. 628 * 629 * In 4.4BSD, the above "if" statement checked 630 * rt->rt_ifa against rt_getkey(rt). It was changed 631 * to the current form so that we can provide a 632 * better support for multiple IPv4 addresses on a 633 * interface. 634 */ 635 rt->rt_expire = 0; 636 (void)sockaddr_dl_setaddr(satosdl(gate), gate->sa_len, 637 CLLADDR(ifp->if_sadl), ifp->if_addrlen); 638 if (useloopback) 639 ifp = rt->rt_ifp = lo0ifp; 640 /* 641 * make sure to set rt->rt_ifa to the interface 642 * address we are using, otherwise we will have trouble 643 * with source address selection. 644 */ 645 ifa = &ia->ia_ifa; 646 if (ifa != rt->rt_ifa) 647 rt_replace_ifa(rt, ifa); 648 } 649 break; 650 651 case RTM_DELETE: 652 if (la == 0) 653 break; 654 arp_inuse--; 655 LIST_REMOVE(la, la_list); 656 rt->rt_llinfo = 0; 657 rt->rt_flags &= ~RTF_LLINFO; 658 659 s = splnet(); 660 mold = la->la_hold; 661 la->la_hold = 0; 662 splx(s); 663 664 if (mold) 665 m_freem(mold); 666 667 Free((void *)la); 668 } 669 ARP_UNLOCK(); 670 } 671 672 /* 673 * Broadcast an ARP request. Caller specifies: 674 * - arp header source ip address 675 * - arp header target ip address 676 * - arp header source ethernet address 677 */ 678 void 679 arprequest(struct ifnet *ifp, 680 const struct in_addr *sip, const struct in_addr *tip, 681 const u_int8_t *enaddr) 682 { 683 struct mbuf *m; 684 struct arphdr *ah; 685 struct sockaddr sa; 686 uint64_t *arps; 687 688 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 689 return; 690 MCLAIM(m, &arpdomain.dom_mowner); 691 switch (ifp->if_type) { 692 case IFT_IEEE1394: 693 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 694 ifp->if_addrlen; 695 break; 696 default: 697 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 698 2 * ifp->if_addrlen; 699 break; 700 } 701 m->m_pkthdr.len = m->m_len; 702 MH_ALIGN(m, m->m_len); 703 ah = mtod(m, struct arphdr *); 704 bzero((void *)ah, m->m_len); 705 switch (ifp->if_type) { 706 case IFT_IEEE1394: /* RFC2734 */ 707 /* fill it now for ar_tpa computation */ 708 ah->ar_hrd = htons(ARPHRD_IEEE1394); 709 break; 710 default: 711 /* ifp->if_output will fill ar_hrd */ 712 break; 713 } 714 ah->ar_pro = htons(ETHERTYPE_IP); 715 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 716 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 717 ah->ar_op = htons(ARPOP_REQUEST); 718 memcpy(ar_sha(ah), enaddr, ah->ar_hln); 719 memcpy(ar_spa(ah), sip, ah->ar_pln); 720 memcpy(ar_tpa(ah), tip, ah->ar_pln); 721 sa.sa_family = AF_ARP; 722 sa.sa_len = 2; 723 m->m_flags |= M_BCAST; 724 arps = ARP_STAT_GETREF(); 725 arps[ARP_STAT_SNDTOTAL]++; 726 arps[ARP_STAT_SENDREQUEST]++; 727 ARP_STAT_PUTREF(); 728 (*ifp->if_output)(ifp, m, &sa, NULL); 729 } 730 731 /* 732 * Resolve an IP address into an ethernet address. If success, 733 * desten is filled in. If there is no entry in arptab, 734 * set one up and broadcast a request for the IP address. 735 * Hold onto this mbuf and resend it once the address 736 * is finally resolved. A return value of 1 indicates 737 * that desten has been filled in and the packet should be sent 738 * normally; a 0 return indicates that the packet has been 739 * taken over here, either now or for later transmission. 740 */ 741 int 742 arpresolve(struct ifnet *ifp, struct rtentry *rt, struct mbuf *m, 743 const struct sockaddr *dst, u_char *desten) 744 { 745 struct llinfo_arp *la; 746 const struct sockaddr_dl *sdl; 747 struct mbuf *mold; 748 int s; 749 750 if ((la = arplookup1(m, &satocsin(dst)->sin_addr, 1, 0, rt)) != NULL) 751 rt = la->la_rt; 752 753 if (la == 0 || rt == 0) { 754 ARP_STATINC(ARP_STAT_ALLOCFAIL); 755 log(LOG_DEBUG, 756 "arpresolve: can't allocate llinfo on %s for %s\n", 757 ifp->if_xname, in_fmtaddr(satocsin(dst)->sin_addr)); 758 m_freem(m); 759 return (0); 760 } 761 sdl = satocsdl(rt->rt_gateway); 762 /* 763 * Check the address family and length is valid, the address 764 * is resolved; otherwise, try to resolve. 765 */ 766 if ((rt->rt_expire == 0 || rt->rt_expire > time_second) && 767 sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) { 768 bcopy(CLLADDR(sdl), desten, 769 min(sdl->sdl_alen, ifp->if_addrlen)); 770 rt->rt_pksent = time_second; /* Time for last pkt sent */ 771 return 1; 772 } 773 /* 774 * There is an arptab entry, but no ethernet address 775 * response yet. Replace the held mbuf with this 776 * latest one. 777 */ 778 779 ARP_STATINC(ARP_STAT_DFRTOTAL); 780 s = splnet(); 781 mold = la->la_hold; 782 la->la_hold = m; 783 splx(s); 784 785 if (mold) { 786 ARP_STATINC(ARP_STAT_DFRDROPPED); 787 m_freem(mold); 788 } 789 790 /* 791 * Re-send the ARP request when appropriate. 792 */ 793 #ifdef DIAGNOSTIC 794 if (rt->rt_expire == 0) { 795 /* This should never happen. (Should it? -gwr) */ 796 printf("arpresolve: unresolved and rt_expire == 0\n"); 797 /* Set expiration time to now (expired). */ 798 rt->rt_expire = time_second; 799 } 800 #endif 801 if (rt->rt_expire) { 802 rt->rt_flags &= ~RTF_REJECT; 803 if (la->la_asked == 0 || rt->rt_expire != time_second) { 804 rt->rt_expire = time_second; 805 if (la->la_asked++ < arp_maxtries) 806 arprequest(ifp, 807 &satocsin(rt->rt_ifa->ifa_addr)->sin_addr, 808 &satocsin(dst)->sin_addr, 809 #if NCARP > 0 810 (rt->rt_ifp->if_type == IFT_CARP) ? 811 CLLADDR(rt->rt_ifp->if_sadl): 812 #endif 813 CLLADDR(ifp->if_sadl)); 814 else { 815 rt->rt_flags |= RTF_REJECT; 816 rt->rt_expire += arpt_down; 817 la->la_asked = 0; 818 } 819 } 820 } 821 return (0); 822 } 823 824 /* 825 * Common length and type checks are done here, 826 * then the protocol-specific routine is called. 827 */ 828 void 829 arpintr(void) 830 { 831 struct mbuf *m; 832 struct arphdr *ar; 833 int s; 834 int arplen; 835 836 mutex_enter(softnet_lock); 837 KERNEL_LOCK(1, NULL); 838 while (arpintrq.ifq_head) { 839 s = splnet(); 840 IF_DEQUEUE(&arpintrq, m); 841 splx(s); 842 if (m == 0 || (m->m_flags & M_PKTHDR) == 0) 843 panic("arpintr"); 844 845 MCLAIM(m, &arpdomain.dom_mowner); 846 ARP_STATINC(ARP_STAT_RCVTOTAL); 847 848 /* 849 * First, make sure we have at least struct arphdr. 850 */ 851 if (m->m_len < sizeof(struct arphdr) || 852 (ar = mtod(m, struct arphdr *)) == NULL) 853 goto badlen; 854 855 switch (m->m_pkthdr.rcvif->if_type) { 856 case IFT_IEEE1394: 857 arplen = sizeof(struct arphdr) + 858 ar->ar_hln + 2 * ar->ar_pln; 859 break; 860 default: 861 arplen = sizeof(struct arphdr) + 862 2 * ar->ar_hln + 2 * ar->ar_pln; 863 break; 864 } 865 866 if (/* XXX ntohs(ar->ar_hrd) == ARPHRD_ETHER && */ 867 m->m_len >= arplen) 868 switch (ntohs(ar->ar_pro)) { 869 case ETHERTYPE_IP: 870 case ETHERTYPE_IPTRAILERS: 871 in_arpinput(m); 872 continue; 873 default: 874 ARP_STATINC(ARP_STAT_RCVBADPROTO); 875 } 876 else { 877 badlen: 878 ARP_STATINC(ARP_STAT_RCVBADLEN); 879 } 880 m_freem(m); 881 } 882 KERNEL_UNLOCK_ONE(NULL); 883 mutex_exit(softnet_lock); 884 } 885 886 /* 887 * ARP for Internet protocols on 10 Mb/s Ethernet. 888 * Algorithm is that given in RFC 826. 889 * In addition, a sanity check is performed on the sender 890 * protocol address, to catch impersonators. 891 * We no longer handle negotiations for use of trailer protocol: 892 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent 893 * along with IP replies if we wanted trailers sent to us, 894 * and also sent them in response to IP replies. 895 * This allowed either end to announce the desire to receive 896 * trailer packets. 897 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, 898 * but formerly didn't normally send requests. 899 */ 900 static void 901 in_arpinput(struct mbuf *m) 902 { 903 struct arphdr *ah; 904 struct ifnet *ifp = m->m_pkthdr.rcvif; 905 struct llinfo_arp *la = 0; 906 struct rtentry *rt; 907 struct in_ifaddr *ia; 908 #if NBRIDGE > 0 909 struct in_ifaddr *bridge_ia = NULL; 910 #endif 911 #if NCARP > 0 912 u_int32_t count = 0, index = 0; 913 #endif 914 struct sockaddr_dl *sdl; 915 struct sockaddr sa; 916 struct in_addr isaddr, itaddr, myaddr; 917 int op; 918 struct mbuf *mold; 919 void *tha; 920 int s; 921 uint64_t *arps; 922 923 if (__predict_false(m_makewritable(&m, 0, m->m_pkthdr.len, M_DONTWAIT))) 924 goto out; 925 ah = mtod(m, struct arphdr *); 926 op = ntohs(ah->ar_op); 927 928 /* 929 * Fix up ah->ar_hrd if necessary, before using ar_tha() or 930 * ar_tpa(). 931 */ 932 switch (ifp->if_type) { 933 case IFT_IEEE1394: 934 if (ntohs(ah->ar_hrd) == ARPHRD_IEEE1394) 935 ; 936 else { 937 /* XXX this is to make sure we compute ar_tha right */ 938 /* XXX check ar_hrd more strictly? */ 939 ah->ar_hrd = htons(ARPHRD_IEEE1394); 940 } 941 break; 942 default: 943 /* XXX check ar_hrd? */ 944 break; 945 } 946 947 memcpy(&isaddr, ar_spa(ah), sizeof (isaddr)); 948 memcpy(&itaddr, ar_tpa(ah), sizeof (itaddr)); 949 950 if (m->m_flags & (M_BCAST|M_MCAST)) 951 ARP_STATINC(ARP_STAT_RCVMCAST); 952 953 /* 954 * If the target IP address is zero, ignore the packet. 955 * This prevents the code below from tring to answer 956 * when we are using IP address zero (booting). 957 */ 958 if (in_nullhost(itaddr)) { 959 ARP_STATINC(ARP_STAT_RCVZEROTPA); 960 goto out; 961 } 962 963 /* 964 * If the source IP address is zero, this is most likely a 965 * confused host trying to use IP address zero. (Windoze?) 966 * XXX: Should we bother trying to reply to these? 967 */ 968 if (in_nullhost(isaddr)) { 969 ARP_STATINC(ARP_STAT_RCVZEROSPA); 970 goto out; 971 } 972 973 /* 974 * Search for a matching interface address 975 * or any address on the interface to use 976 * as a dummy address in the rest of this function 977 */ 978 979 INADDR_TO_IA(itaddr, ia); 980 while (ia != NULL) { 981 #if NCARP > 0 982 if (ia->ia_ifp->if_type == IFT_CARP && 983 ((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) == 984 (IFF_UP|IFF_RUNNING))) { 985 index++; 986 if (ia->ia_ifp == m->m_pkthdr.rcvif && 987 carp_iamatch(ia, ar_sha(ah), 988 &count, index)) { 989 break; 990 } 991 } else 992 #endif 993 if (ia->ia_ifp == m->m_pkthdr.rcvif) 994 break; 995 #if NBRIDGE > 0 996 /* 997 * If the interface we received the packet on 998 * is part of a bridge, check to see if we need 999 * to "bridge" the packet to ourselves at this 1000 * layer. Note we still prefer a perfect match, 1001 * but allow this weaker match if necessary. 1002 */ 1003 if (m->m_pkthdr.rcvif->if_bridge != NULL && 1004 m->m_pkthdr.rcvif->if_bridge == ia->ia_ifp->if_bridge) 1005 bridge_ia = ia; 1006 #endif /* NBRIDGE > 0 */ 1007 1008 NEXT_IA_WITH_SAME_ADDR(ia); 1009 } 1010 1011 #if NBRIDGE > 0 1012 if (ia == NULL && bridge_ia != NULL) { 1013 ia = bridge_ia; 1014 ifp = bridge_ia->ia_ifp; 1015 } 1016 #endif 1017 1018 if (ia == NULL) { 1019 INADDR_TO_IA(isaddr, ia); 1020 while ((ia != NULL) && ia->ia_ifp != m->m_pkthdr.rcvif) 1021 NEXT_IA_WITH_SAME_ADDR(ia); 1022 1023 if (ia == NULL) { 1024 IFP_TO_IA(ifp, ia); 1025 if (ia == NULL) { 1026 ARP_STATINC(ARP_STAT_RCVNOINT); 1027 goto out; 1028 } 1029 } 1030 } 1031 1032 myaddr = ia->ia_addr.sin_addr; 1033 1034 /* XXX checks for bridge case? */ 1035 if (!memcmp(ar_sha(ah), CLLADDR(ifp->if_sadl), ifp->if_addrlen)) { 1036 ARP_STATINC(ARP_STAT_RCVLOCALSHA); 1037 goto out; /* it's from me, ignore it. */ 1038 } 1039 1040 /* XXX checks for bridge case? */ 1041 if (!memcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 1042 ARP_STATINC(ARP_STAT_RCVBCASTSHA); 1043 log(LOG_ERR, 1044 "%s: arp: link address is broadcast for IP address %s!\n", 1045 ifp->if_xname, in_fmtaddr(isaddr)); 1046 goto out; 1047 } 1048 1049 if (in_hosteq(isaddr, myaddr)) { 1050 ARP_STATINC(ARP_STAT_RCVLOCALSPA); 1051 log(LOG_ERR, 1052 "duplicate IP address %s sent from link address %s\n", 1053 in_fmtaddr(isaddr), lla_snprintf(ar_sha(ah), ah->ar_hln)); 1054 itaddr = myaddr; 1055 goto reply; 1056 } 1057 la = arplookup(m, &isaddr, in_hosteq(itaddr, myaddr), 0); 1058 if (la && (rt = la->la_rt) && (sdl = satosdl(rt->rt_gateway))) { 1059 if (sdl->sdl_alen && 1060 memcmp(ar_sha(ah), CLLADDR(sdl), sdl->sdl_alen)) { 1061 if (rt->rt_flags & RTF_STATIC) { 1062 ARP_STATINC(ARP_STAT_RCVOVERPERM); 1063 log(LOG_INFO, 1064 "%s tried to overwrite permanent arp info" 1065 " for %s\n", 1066 lla_snprintf(ar_sha(ah), ah->ar_hln), 1067 in_fmtaddr(isaddr)); 1068 goto out; 1069 } else if (rt->rt_ifp != ifp) { 1070 ARP_STATINC(ARP_STAT_RCVOVERINT); 1071 log(LOG_INFO, 1072 "%s on %s tried to overwrite " 1073 "arp info for %s on %s\n", 1074 lla_snprintf(ar_sha(ah), ah->ar_hln), 1075 ifp->if_xname, in_fmtaddr(isaddr), 1076 rt->rt_ifp->if_xname); 1077 goto out; 1078 } else { 1079 ARP_STATINC(ARP_STAT_RCVOVER); 1080 log(LOG_INFO, 1081 "arp info overwritten for %s by %s\n", 1082 in_fmtaddr(isaddr), 1083 lla_snprintf(ar_sha(ah), ah->ar_hln)); 1084 } 1085 } 1086 /* 1087 * sanity check for the address length. 1088 * XXX this does not work for protocols with variable address 1089 * length. -is 1090 */ 1091 if (sdl->sdl_alen && 1092 sdl->sdl_alen != ah->ar_hln) { 1093 ARP_STATINC(ARP_STAT_RCVLENCHG); 1094 log(LOG_WARNING, 1095 "arp from %s: new addr len %d, was %d", 1096 in_fmtaddr(isaddr), ah->ar_hln, sdl->sdl_alen); 1097 } 1098 if (ifp->if_addrlen != ah->ar_hln) { 1099 ARP_STATINC(ARP_STAT_RCVBADLEN); 1100 log(LOG_WARNING, 1101 "arp from %s: addr len: new %d, i/f %d (ignored)", 1102 in_fmtaddr(isaddr), ah->ar_hln, 1103 ifp->if_addrlen); 1104 goto reply; 1105 } 1106 #if NTOKEN > 0 1107 /* 1108 * XXX uses m_data and assumes the complete answer including 1109 * XXX token-ring headers is in the same buf 1110 */ 1111 if (ifp->if_type == IFT_ISO88025) { 1112 struct token_header *trh; 1113 1114 trh = (struct token_header *)M_TRHSTART(m); 1115 if (trh->token_shost[0] & TOKEN_RI_PRESENT) { 1116 struct token_rif *rif; 1117 size_t riflen; 1118 1119 rif = TOKEN_RIF(trh); 1120 riflen = (ntohs(rif->tr_rcf) & 1121 TOKEN_RCF_LEN_MASK) >> 8; 1122 1123 if (riflen > 2 && 1124 riflen < sizeof(struct token_rif) && 1125 (riflen & 1) == 0) { 1126 rif->tr_rcf ^= htons(TOKEN_RCF_DIRECTION); 1127 rif->tr_rcf &= htons(~TOKEN_RCF_BROADCAST_MASK); 1128 bcopy(rif, TOKEN_RIF(la), riflen); 1129 } 1130 } 1131 } 1132 #endif /* NTOKEN > 0 */ 1133 (void)sockaddr_dl_setaddr(sdl, sdl->sdl_len, ar_sha(ah), 1134 ah->ar_hln); 1135 if (rt->rt_expire) 1136 rt->rt_expire = time_second + arpt_keep; 1137 rt->rt_flags &= ~RTF_REJECT; 1138 la->la_asked = 0; 1139 1140 s = splnet(); 1141 mold = la->la_hold; 1142 la->la_hold = 0; 1143 splx(s); 1144 1145 if (mold) { 1146 ARP_STATINC(ARP_STAT_DFRSENT); 1147 (*ifp->if_output)(ifp, mold, rt_getkey(rt), rt); 1148 } 1149 } 1150 reply: 1151 if (op != ARPOP_REQUEST) { 1152 if (op == ARPOP_REPLY) 1153 ARP_STATINC(ARP_STAT_RCVREPLY); 1154 out: 1155 m_freem(m); 1156 return; 1157 } 1158 ARP_STATINC(ARP_STAT_RCVREQUEST); 1159 if (in_hosteq(itaddr, myaddr)) { 1160 /* I am the target */ 1161 tha = ar_tha(ah); 1162 if (tha) 1163 memcpy(tha, ar_sha(ah), ah->ar_hln); 1164 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1165 } else { 1166 la = arplookup(m, &itaddr, 0, SIN_PROXY); 1167 if (la == 0) 1168 goto out; 1169 rt = la->la_rt; 1170 if (rt->rt_ifp->if_type == IFT_CARP && 1171 m->m_pkthdr.rcvif->if_type != IFT_CARP) 1172 goto out; 1173 tha = ar_tha(ah); 1174 if (tha) 1175 memcpy(tha, ar_sha(ah), ah->ar_hln); 1176 sdl = satosdl(rt->rt_gateway); 1177 memcpy(ar_sha(ah), CLLADDR(sdl), ah->ar_hln); 1178 } 1179 1180 memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); 1181 memcpy(ar_spa(ah), &itaddr, ah->ar_pln); 1182 ah->ar_op = htons(ARPOP_REPLY); 1183 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 1184 switch (ifp->if_type) { 1185 case IFT_IEEE1394: 1186 /* 1187 * ieee1394 arp reply is broadcast 1188 */ 1189 m->m_flags &= ~M_MCAST; 1190 m->m_flags |= M_BCAST; 1191 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + ah->ar_hln; 1192 break; 1193 1194 default: 1195 m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */ 1196 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); 1197 break; 1198 } 1199 m->m_pkthdr.len = m->m_len; 1200 sa.sa_family = AF_ARP; 1201 sa.sa_len = 2; 1202 arps = ARP_STAT_GETREF(); 1203 arps[ARP_STAT_SNDTOTAL]++; 1204 arps[ARP_STAT_SNDREPLY]++; 1205 ARP_STAT_PUTREF(); 1206 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); 1207 return; 1208 } 1209 1210 /* 1211 * Free an arp entry. 1212 */ 1213 static void arptfree(struct llinfo_arp *la) 1214 { 1215 struct rtentry *rt = la->la_rt; 1216 struct sockaddr_dl *sdl; 1217 1218 ARP_LOCK_CHECK(); 1219 1220 if (rt == 0) 1221 panic("arptfree"); 1222 if (rt->rt_refcnt > 0 && (sdl = satosdl(rt->rt_gateway)) && 1223 sdl->sdl_family == AF_LINK) { 1224 sdl->sdl_alen = 0; 1225 la->la_asked = 0; 1226 rt->rt_flags &= ~RTF_REJECT; 1227 return; 1228 } 1229 rtrequest(RTM_DELETE, rt_getkey(rt), NULL, rt_mask(rt), 0, NULL); 1230 } 1231 1232 static struct llinfo_arp * 1233 arplookup(struct mbuf *m, const struct in_addr *addr, int create, int proxy) 1234 { 1235 return arplookup1(m, addr, create, proxy, NULL); 1236 } 1237 1238 /* 1239 * Lookup or enter a new address in arptab. 1240 */ 1241 static struct llinfo_arp * 1242 arplookup1(struct mbuf *m, const struct in_addr *addr, int create, int proxy, 1243 struct rtentry *rt0) 1244 { 1245 struct arphdr *ah; 1246 struct ifnet *ifp = m->m_pkthdr.rcvif; 1247 struct rtentry *rt; 1248 static struct sockaddr_inarp sin; 1249 const char *why = 0; 1250 1251 ah = mtod(m, struct arphdr *); 1252 if (rt0 == NULL) { 1253 sin.sin_len = sizeof(sin); 1254 sin.sin_family = AF_INET; 1255 sin.sin_addr = *addr; 1256 sin.sin_other = proxy ? SIN_PROXY : 0; 1257 rt = rtalloc1(sintosa(&sin), create); 1258 if (rt == NULL) 1259 return (NULL); 1260 rt->rt_refcnt--; 1261 } else 1262 rt = rt0; 1263 1264 #define IS_LLINFO(__rt) \ 1265 (((__rt)->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) == RTF_LLINFO && \ 1266 (__rt)->rt_gateway->sa_family == AF_LINK) 1267 1268 1269 if (IS_LLINFO(rt)) 1270 return ((struct llinfo_arp *)rt->rt_llinfo); 1271 1272 if (create) { 1273 if (rt->rt_flags & RTF_GATEWAY) 1274 why = "host is not on local network"; 1275 else if ((rt->rt_flags & RTF_LLINFO) == 0) { 1276 ARP_STATINC(ARP_STAT_ALLOCFAIL); 1277 why = "could not allocate llinfo"; 1278 } else 1279 why = "gateway route is not ours"; 1280 log(LOG_DEBUG, "arplookup: unable to enter address" 1281 " for %s@%s on %s (%s)\n", 1282 in_fmtaddr(*addr), lla_snprintf(ar_sha(ah), ah->ar_hln), 1283 (ifp) ? ifp->if_xname : 0, why); 1284 if (rt->rt_refcnt <= 0 && (rt->rt_flags & RTF_CLONED) != 0) { 1285 rtrequest(RTM_DELETE, rt_getkey(rt), 1286 rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0); 1287 } 1288 } 1289 return (0); 1290 } 1291 1292 int 1293 arpioctl(u_long cmd, void *data) 1294 { 1295 1296 return (EOPNOTSUPP); 1297 } 1298 1299 void 1300 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1301 { 1302 struct in_addr *ip; 1303 1304 /* 1305 * Warn the user if another station has this IP address, 1306 * but only if the interface IP address is not zero. 1307 */ 1308 ip = &IA_SIN(ifa)->sin_addr; 1309 if (!in_nullhost(*ip)) 1310 arprequest(ifp, ip, ip, CLLADDR(ifp->if_sadl)); 1311 1312 ifa->ifa_rtrequest = arp_rtrequest; 1313 ifa->ifa_flags |= RTF_CLONING; 1314 } 1315 1316 /* 1317 * Called from 10 Mb/s Ethernet interrupt handlers 1318 * when ether packet type ETHERTYPE_REVARP 1319 * is received. Common length and type checks are done here, 1320 * then the protocol-specific routine is called. 1321 */ 1322 void 1323 revarpinput(struct mbuf *m) 1324 { 1325 struct arphdr *ar; 1326 1327 if (m->m_len < sizeof(struct arphdr)) 1328 goto out; 1329 ar = mtod(m, struct arphdr *); 1330 #if 0 /* XXX I don't think we need this... and it will prevent other LL */ 1331 if (ntohs(ar->ar_hrd) != ARPHRD_ETHER) 1332 goto out; 1333 #endif 1334 if (m->m_len < sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln)) 1335 goto out; 1336 switch (ntohs(ar->ar_pro)) { 1337 case ETHERTYPE_IP: 1338 case ETHERTYPE_IPTRAILERS: 1339 in_revarpinput(m); 1340 return; 1341 1342 default: 1343 break; 1344 } 1345 out: 1346 m_freem(m); 1347 } 1348 1349 /* 1350 * RARP for Internet protocols on 10 Mb/s Ethernet. 1351 * Algorithm is that given in RFC 903. 1352 * We are only using for bootstrap purposes to get an ip address for one of 1353 * our interfaces. Thus we support no user-interface. 1354 * 1355 * Since the contents of the RARP reply are specific to the interface that 1356 * sent the request, this code must ensure that they are properly associated. 1357 * 1358 * Note: also supports ARP via RARP packets, per the RFC. 1359 */ 1360 void 1361 in_revarpinput(struct mbuf *m) 1362 { 1363 struct ifnet *ifp; 1364 struct arphdr *ah; 1365 void *tha; 1366 int op; 1367 1368 ah = mtod(m, struct arphdr *); 1369 op = ntohs(ah->ar_op); 1370 1371 switch (m->m_pkthdr.rcvif->if_type) { 1372 case IFT_IEEE1394: 1373 /* ARP without target hardware address is not supported */ 1374 goto out; 1375 default: 1376 break; 1377 } 1378 1379 switch (op) { 1380 case ARPOP_REQUEST: 1381 case ARPOP_REPLY: /* per RFC */ 1382 in_arpinput(m); 1383 return; 1384 case ARPOP_REVREPLY: 1385 break; 1386 case ARPOP_REVREQUEST: /* handled by rarpd(8) */ 1387 default: 1388 goto out; 1389 } 1390 if (!revarp_in_progress) 1391 goto out; 1392 ifp = m->m_pkthdr.rcvif; 1393 if (ifp != myip_ifp) /* !same interface */ 1394 goto out; 1395 if (myip_initialized) 1396 goto wake; 1397 tha = ar_tha(ah); 1398 KASSERT(tha); 1399 if (bcmp(tha, CLLADDR(ifp->if_sadl), ifp->if_sadl->sdl_alen)) 1400 goto out; 1401 memcpy(&srv_ip, ar_spa(ah), sizeof(srv_ip)); 1402 memcpy(&myip, ar_tpa(ah), sizeof(myip)); 1403 myip_initialized = 1; 1404 wake: /* Do wakeup every time in case it was missed. */ 1405 wakeup((void *)&myip); 1406 1407 out: 1408 m_freem(m); 1409 } 1410 1411 /* 1412 * Send a RARP request for the ip address of the specified interface. 1413 * The request should be RFC 903-compliant. 1414 */ 1415 void 1416 revarprequest(struct ifnet *ifp) 1417 { 1418 struct sockaddr sa; 1419 struct mbuf *m; 1420 struct arphdr *ah; 1421 void *tha; 1422 1423 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 1424 return; 1425 MCLAIM(m, &arpdomain.dom_mowner); 1426 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) + 1427 2*ifp->if_addrlen; 1428 m->m_pkthdr.len = m->m_len; 1429 MH_ALIGN(m, m->m_len); 1430 ah = mtod(m, struct arphdr *); 1431 bzero((void *)ah, m->m_len); 1432 ah->ar_pro = htons(ETHERTYPE_IP); 1433 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 1434 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 1435 ah->ar_op = htons(ARPOP_REVREQUEST); 1436 1437 memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln); 1438 tha = ar_tha(ah); 1439 KASSERT(tha); 1440 bcopy(CLLADDR(ifp->if_sadl), tha, ah->ar_hln); 1441 1442 sa.sa_family = AF_ARP; 1443 sa.sa_len = 2; 1444 m->m_flags |= M_BCAST; 1445 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); 1446 1447 } 1448 1449 /* 1450 * RARP for the ip address of the specified interface, but also 1451 * save the ip address of the server that sent the answer. 1452 * Timeout if no response is received. 1453 */ 1454 int 1455 revarpwhoarewe(struct ifnet *ifp, struct in_addr *serv_in, 1456 struct in_addr *clnt_in) 1457 { 1458 int result, count = 20; 1459 1460 myip_initialized = 0; 1461 myip_ifp = ifp; 1462 1463 revarp_in_progress = 1; 1464 while (count--) { 1465 revarprequest(ifp); 1466 result = tsleep((void *)&myip, PSOCK, "revarp", hz/2); 1467 if (result != EWOULDBLOCK) 1468 break; 1469 } 1470 revarp_in_progress = 0; 1471 1472 if (!myip_initialized) 1473 return ENETUNREACH; 1474 1475 bcopy((void *)&srv_ip, serv_in, sizeof(*serv_in)); 1476 bcopy((void *)&myip, clnt_in, sizeof(*clnt_in)); 1477 return 0; 1478 } 1479 1480 1481 1482 #ifdef DDB 1483 1484 #include <machine/db_machdep.h> 1485 #include <ddb/db_interface.h> 1486 #include <ddb/db_output.h> 1487 1488 static void 1489 db_print_sa(const struct sockaddr *sa) 1490 { 1491 int len; 1492 const u_char *p; 1493 1494 if (sa == 0) { 1495 db_printf("[NULL]"); 1496 return; 1497 } 1498 1499 p = (const u_char *)sa; 1500 len = sa->sa_len; 1501 db_printf("["); 1502 while (len > 0) { 1503 db_printf("%d", *p); 1504 p++; len--; 1505 if (len) db_printf(","); 1506 } 1507 db_printf("]\n"); 1508 } 1509 1510 static void 1511 db_print_ifa(struct ifaddr *ifa) 1512 { 1513 if (ifa == 0) 1514 return; 1515 db_printf(" ifa_addr="); 1516 db_print_sa(ifa->ifa_addr); 1517 db_printf(" ifa_dsta="); 1518 db_print_sa(ifa->ifa_dstaddr); 1519 db_printf(" ifa_mask="); 1520 db_print_sa(ifa->ifa_netmask); 1521 db_printf(" flags=0x%x,refcnt=%d,metric=%d\n", 1522 ifa->ifa_flags, 1523 ifa->ifa_refcnt, 1524 ifa->ifa_metric); 1525 } 1526 1527 static void 1528 db_print_llinfo(void *li) 1529 { 1530 struct llinfo_arp *la; 1531 1532 if (li == 0) 1533 return; 1534 la = (struct llinfo_arp *)li; 1535 db_printf(" la_rt=%p la_hold=%p, la_asked=0x%lx\n", 1536 la->la_rt, la->la_hold, la->la_asked); 1537 } 1538 1539 /* 1540 * Function to pass to rt_walktree(). 1541 * Return non-zero error to abort walk. 1542 */ 1543 static int 1544 db_show_rtentry(struct rtentry *rt, void *w) 1545 { 1546 db_printf("rtentry=%p", rt); 1547 1548 db_printf(" flags=0x%x refcnt=%d use=%ld expire=%ld\n", 1549 rt->rt_flags, rt->rt_refcnt, 1550 rt->rt_use, rt->rt_expire); 1551 1552 db_printf(" key="); db_print_sa(rt_getkey(rt)); 1553 db_printf(" mask="); db_print_sa(rt_mask(rt)); 1554 db_printf(" gw="); db_print_sa(rt->rt_gateway); 1555 1556 db_printf(" ifp=%p ", rt->rt_ifp); 1557 if (rt->rt_ifp) 1558 db_printf("(%s)", rt->rt_ifp->if_xname); 1559 else 1560 db_printf("(NULL)"); 1561 1562 db_printf(" ifa=%p\n", rt->rt_ifa); 1563 db_print_ifa(rt->rt_ifa); 1564 1565 db_printf(" gwroute=%p llinfo=%p\n", 1566 rt->rt_gwroute, rt->rt_llinfo); 1567 db_print_llinfo(rt->rt_llinfo); 1568 1569 return (0); 1570 } 1571 1572 /* 1573 * Function to print all the route trees. 1574 * Use this from ddb: "show arptab" 1575 */ 1576 void 1577 db_show_arptab(db_expr_t addr, bool have_addr, 1578 db_expr_t count, const char *modif) 1579 { 1580 rt_walktree(AF_INET, db_show_rtentry, NULL); 1581 } 1582 #endif 1583 1584 static int 1585 sysctl_net_inet_arp_stats(SYSCTLFN_ARGS) 1586 { 1587 netstat_sysctl_context ctx; 1588 uint64_t arps[ARP_NSTATS]; 1589 1590 ctx.ctx_stat = arpstat_percpu; 1591 ctx.ctx_counters = arps; 1592 ctx.ctx_ncounters = ARP_NSTATS; 1593 return (NETSTAT_SYSCTL(&ctx)); 1594 } 1595 1596 SYSCTL_SETUP(sysctl_net_inet_arp_setup, "sysctl net.inet.arp subtree setup") 1597 { 1598 const struct sysctlnode *node; 1599 1600 sysctl_createv(clog, 0, NULL, NULL, 1601 CTLFLAG_PERMANENT, 1602 CTLTYPE_NODE, "net", NULL, 1603 NULL, 0, NULL, 0, 1604 CTL_NET, CTL_EOL); 1605 sysctl_createv(clog, 0, NULL, NULL, 1606 CTLFLAG_PERMANENT, 1607 CTLTYPE_NODE, "inet", NULL, 1608 NULL, 0, NULL, 0, 1609 CTL_NET, PF_INET, CTL_EOL); 1610 sysctl_createv(clog, 0, NULL, &node, 1611 CTLFLAG_PERMANENT, 1612 CTLTYPE_NODE, "arp", 1613 SYSCTL_DESCR("Address Resolution Protocol"), 1614 NULL, 0, NULL, 0, 1615 CTL_NET, PF_INET, CTL_CREATE, CTL_EOL); 1616 1617 sysctl_createv(clog, 0, NULL, NULL, 1618 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1619 CTLTYPE_INT, "prune", 1620 SYSCTL_DESCR("ARP cache pruning interval"), 1621 NULL, 0, &arpt_prune, 0, 1622 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1623 1624 sysctl_createv(clog, 0, NULL, NULL, 1625 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1626 CTLTYPE_INT, "keep", 1627 SYSCTL_DESCR("Valid ARP entry lifetime"), 1628 NULL, 0, &arpt_keep, 0, 1629 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1630 1631 sysctl_createv(clog, 0, NULL, NULL, 1632 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1633 CTLTYPE_INT, "down", 1634 SYSCTL_DESCR("Failed ARP entry lifetime"), 1635 NULL, 0, &arpt_down, 0, 1636 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1637 1638 sysctl_createv(clog, 0, NULL, NULL, 1639 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1640 CTLTYPE_INT, "refresh", 1641 SYSCTL_DESCR("ARP entry refresh interval"), 1642 NULL, 0, &arpt_refresh, 0, 1643 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1644 1645 sysctl_createv(clog, 0, NULL, NULL, 1646 CTLFLAG_PERMANENT, 1647 CTLTYPE_STRUCT, "stats", 1648 SYSCTL_DESCR("ARP statistics"), 1649 sysctl_net_inet_arp_stats, 0, NULL, 0, 1650 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1651 } 1652 1653 #endif /* INET */ 1654