1 /* $NetBSD: if_arp.c,v 1.114 2006/10/12 01:32:37 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 1998, 2000 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 1.114 2006/10/12 01:32:37 christos 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> 103 104 #include <net/ethertypes.h> 105 #include <net/if.h> 106 #include <net/if_dl.h> 107 #include <net/if_token.h> 108 #include <net/if_types.h> 109 #include <net/if_ether.h> 110 #include <net/route.h> 111 112 #include <netinet/in.h> 113 #include <netinet/in_systm.h> 114 #include <netinet/in_var.h> 115 #include <netinet/ip.h> 116 #include <netinet/if_inarp.h> 117 118 #include "arc.h" 119 #if NARC > 0 120 #include <net/if_arc.h> 121 #endif 122 #include "fddi.h" 123 #if NFDDI > 0 124 #include <net/if_fddi.h> 125 #endif 126 #include "token.h" 127 #include "carp.h" 128 #if NCARP > 0 129 #include <netinet/ip_carp.h> 130 #endif 131 132 #define SIN(s) ((struct sockaddr_in *)s) 133 #define SDL(s) ((struct sockaddr_dl *)s) 134 #define SRP(s) ((struct sockaddr_inarp *)s) 135 136 /* 137 * ARP trailer negotiation. Trailer protocol is not IP specific, 138 * but ARP request/response use IP addresses. 139 */ 140 #define ETHERTYPE_IPTRAILERS ETHERTYPE_TRAIL 141 142 /* timer values */ 143 int arpt_prune = (5*60*1); /* walk list every 5 minutes */ 144 int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */ 145 int arpt_down = 20; /* once declared down, don't send for 20 secs */ 146 int arpt_refresh = (5*60); /* time left before refreshing */ 147 #define rt_expire rt_rmx.rmx_expire 148 #define rt_pksent rt_rmx.rmx_pksent 149 150 static void arptfree(struct llinfo_arp *); 151 static void arptimer(void *); 152 static struct llinfo_arp *arplookup(struct mbuf *, struct in_addr *, 153 int, int); 154 static void in_arpinput(struct mbuf *); 155 156 LIST_HEAD(, llinfo_arp) llinfo_arp; 157 struct ifqueue arpintrq = { 158 .ifq_head = NULL, 159 .ifq_tail = NULL, 160 .ifq_len = 0, 161 .ifq_maxlen = 50, 162 .ifq_drops = 0, 163 }; 164 int arp_inuse, arp_allocated, arp_intimer; 165 int arp_maxtries = 5; 166 int useloopback = 1; /* use loopback interface for local traffic */ 167 int arpinit_done = 0; 168 169 struct arpstat arpstat; 170 struct callout arptimer_ch; 171 172 173 /* revarp state */ 174 struct in_addr myip, srv_ip; 175 int myip_initialized = 0; 176 int revarp_in_progress = 0; 177 struct ifnet *myip_ifp = NULL; 178 179 #ifdef DDB 180 static void db_print_sa(const struct sockaddr *); 181 static void db_print_ifa(struct ifaddr *); 182 static void db_print_llinfo(caddr_t); 183 static int db_show_radix_node(struct radix_node *, void *); 184 #endif 185 186 /* 187 * this should be elsewhere. 188 */ 189 190 static char * 191 lla_snprintf(u_int8_t *, int); 192 193 static char * 194 lla_snprintf(u_int8_t *adrp, int len) 195 { 196 #define NUMBUFS 3 197 static char buf[NUMBUFS][16*3]; 198 static int bnum = 0; 199 200 int i; 201 char *p; 202 203 p = buf[bnum]; 204 205 *p++ = hexdigits[(*adrp)>>4]; 206 *p++ = hexdigits[(*adrp++)&0xf]; 207 208 for (i=1; i<len && i<16; i++) { 209 *p++ = ':'; 210 *p++ = hexdigits[(*adrp)>>4]; 211 *p++ = hexdigits[(*adrp++)&0xf]; 212 } 213 214 *p = 0; 215 p = buf[bnum]; 216 bnum = (bnum + 1) % NUMBUFS; 217 return p; 218 } 219 220 DOMAIN_DEFINE(arpdomain); /* forward declare and add to link set */ 221 222 const struct protosw arpsw[] = { 223 { 0, &arpdomain, 0, 0, 224 0, 0, 0, 0, 225 0, 226 0, 0, 0, arp_drain, 227 } 228 }; 229 230 231 struct domain arpdomain = { 232 .dom_family = PF_ARP, 233 .dom_name = "arp", 234 .dom_protosw = arpsw, 235 .dom_protoswNPROTOSW = &arpsw[sizeof(arpsw)/sizeof(arpsw[0])], 236 }; 237 238 /* 239 * ARP table locking. 240 * 241 * to prevent lossage vs. the arp_drain routine (which may be called at 242 * any time, including in a device driver context), we do two things: 243 * 244 * 1) manipulation of la->la_hold is done at splnet() (for all of 245 * about two instructions). 246 * 247 * 2) manipulation of the arp table's linked list is done under the 248 * protection of the ARP_LOCK; if arp_drain() or arptimer is called 249 * while the arp table is locked, we punt and try again later. 250 */ 251 252 static int arp_locked; 253 static inline int arp_lock_try(int); 254 static inline void arp_unlock(void); 255 256 static inline int 257 arp_lock_try(int recurse) 258 { 259 int s; 260 261 /* 262 * Use splvm() -- we're blocking things that would cause 263 * mbuf allocation. 264 */ 265 s = splvm(); 266 if (!recurse && arp_locked) { 267 splx(s); 268 return (0); 269 } 270 arp_locked++; 271 splx(s); 272 return (1); 273 } 274 275 static inline void 276 arp_unlock(void) 277 { 278 int s; 279 280 s = splvm(); 281 arp_locked--; 282 splx(s); 283 } 284 285 #ifdef DIAGNOSTIC 286 #define ARP_LOCK(recurse) \ 287 do { \ 288 if (arp_lock_try(recurse) == 0) { \ 289 printf("%s:%d: arp already locked\n", __FILE__, __LINE__); \ 290 panic("arp_lock"); \ 291 } \ 292 } while (/*CONSTCOND*/ 0) 293 #define ARP_LOCK_CHECK() \ 294 do { \ 295 if (arp_locked == 0) { \ 296 printf("%s:%d: arp lock not held\n", __FILE__, __LINE__); \ 297 panic("arp lock check"); \ 298 } \ 299 } while (/*CONSTCOND*/ 0) 300 #else 301 #define ARP_LOCK(x) (void) arp_lock_try(x) 302 #define ARP_LOCK_CHECK() /* nothing */ 303 #endif 304 305 #define ARP_UNLOCK() arp_unlock() 306 307 /* 308 * ARP protocol drain routine. Called when memory is in short supply. 309 * Called at splvm(); 310 */ 311 312 void 313 arp_drain(void) 314 { 315 struct llinfo_arp *la, *nla; 316 int count = 0; 317 struct mbuf *mold; 318 319 if (arp_lock_try(0) == 0) { 320 printf("arp_drain: locked; punting\n"); 321 return; 322 } 323 324 for (la = LIST_FIRST(&llinfo_arp); la != 0; la = nla) { 325 nla = LIST_NEXT(la, la_list); 326 327 mold = la->la_hold; 328 la->la_hold = 0; 329 330 if (mold) { 331 m_freem(mold); 332 count++; 333 } 334 } 335 ARP_UNLOCK(); 336 arpstat.as_dfrdropped += count; 337 } 338 339 340 /* 341 * Timeout routine. Age arp_tab entries periodically. 342 */ 343 /* ARGSUSED */ 344 static void 345 arptimer(void *arg __unused) 346 { 347 int s; 348 struct llinfo_arp *la, *nla; 349 350 s = splsoftnet(); 351 352 if (arp_lock_try(0) == 0) { 353 /* get it later.. */ 354 splx(s); 355 return; 356 } 357 358 callout_reset(&arptimer_ch, arpt_prune * hz, arptimer, NULL); 359 for (la = LIST_FIRST(&llinfo_arp); la != 0; la = nla) { 360 struct rtentry *rt = la->la_rt; 361 362 nla = LIST_NEXT(la, la_list); 363 if (rt->rt_expire == 0) 364 continue; 365 if ((rt->rt_expire - time_second) < arpt_refresh && 366 rt->rt_pksent > (time_second - arpt_keep)) { 367 /* 368 * If the entry has been used during since last 369 * refresh, try to renew it before deleting. 370 */ 371 arprequest(rt->rt_ifp, 372 &SIN(rt->rt_ifa->ifa_addr)->sin_addr, 373 &SIN(rt_key(rt))->sin_addr, 374 LLADDR(rt->rt_ifp->if_sadl)); 375 } else if (rt->rt_expire <= time_second) 376 arptfree(la); /* timer has expired; clear */ 377 } 378 379 ARP_UNLOCK(); 380 381 splx(s); 382 } 383 384 /* 385 * Parallel to llc_rtrequest. 386 */ 387 void 388 arp_rtrequest(int req, struct rtentry *rt, struct rt_addrinfo *info __unused) 389 { 390 struct sockaddr *gate = rt->rt_gateway; 391 struct llinfo_arp *la = (struct llinfo_arp *)rt->rt_llinfo; 392 static const struct sockaddr_dl null_sdl = { 393 .sdl_len = sizeof(null_sdl), 394 .sdl_family = AF_LINK, 395 }; 396 size_t allocsize; 397 struct mbuf *mold; 398 int s; 399 struct in_ifaddr *ia; 400 struct ifaddr *ifa; 401 402 if (!arpinit_done) { 403 arpinit_done = 1; 404 /* 405 * We generate expiration times from time_second 406 * so avoid accidently creating permanent routes. 407 */ 408 if (time_second == 0) { 409 #ifdef __HAVE_TIMECOUNTER 410 struct timespec ts; 411 ts.tv_sec = 1; 412 ts.tv_nsec = 0; 413 tc_setclock(&ts); 414 #else /* !__HAVE_TIMECOUNTER */ 415 time.tv_sec++; 416 #endif /* !__HAVE_TIMECOUNTER */ 417 } 418 callout_init(&arptimer_ch); 419 callout_reset(&arptimer_ch, hz, arptimer, NULL); 420 } 421 422 if ((rt->rt_flags & RTF_GATEWAY) != 0) { 423 if (req != RTM_ADD) 424 return; 425 426 /* 427 * linklayers with particular link MTU limitation. 428 */ 429 switch(rt->rt_ifp->if_type) { 430 #if NFDDI > 0 431 case IFT_FDDI: 432 if (rt->rt_ifp->if_mtu > FDDIIPMTU) 433 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 434 break; 435 #endif 436 #if NARC > 0 437 case IFT_ARCNET: 438 { 439 int arcipifmtu; 440 441 if (rt->rt_ifp->if_flags & IFF_LINK0) 442 arcipifmtu = arc_ipmtu; 443 else 444 arcipifmtu = ARCMTU; 445 if (rt->rt_ifp->if_mtu > arcipifmtu) 446 rt->rt_rmx.rmx_mtu = arcipifmtu; 447 break; 448 } 449 #endif 450 } 451 return; 452 } 453 454 ARP_LOCK(1); /* we may already be locked here. */ 455 456 switch (req) { 457 458 case RTM_ADD: 459 /* 460 * XXX: If this is a manually added route to interface 461 * such as older version of routed or gated might provide, 462 * restore cloning bit. 463 */ 464 if ((rt->rt_flags & RTF_HOST) == 0 && 465 SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff) 466 rt->rt_flags |= RTF_CLONING; 467 if (rt->rt_flags & RTF_CLONING) { 468 /* 469 * Case 1: This route should come from a route to iface. 470 */ 471 rt_setgate(rt, rt_key(rt), 472 (const struct sockaddr *)&null_sdl); 473 gate = rt->rt_gateway; 474 SDL(gate)->sdl_type = rt->rt_ifp->if_type; 475 SDL(gate)->sdl_index = rt->rt_ifp->if_index; 476 /* 477 * Give this route an expiration time, even though 478 * it's a "permanent" route, so that routes cloned 479 * from it do not need their expiration time set. 480 */ 481 rt->rt_expire = time_second; 482 /* 483 * linklayers with particular link MTU limitation. 484 */ 485 switch (rt->rt_ifp->if_type) { 486 #if NFDDI > 0 487 case IFT_FDDI: 488 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 489 (rt->rt_rmx.rmx_mtu > FDDIIPMTU || 490 (rt->rt_rmx.rmx_mtu == 0 && 491 rt->rt_ifp->if_mtu > FDDIIPMTU))) 492 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 493 break; 494 #endif 495 #if NARC > 0 496 case IFT_ARCNET: 497 { 498 int arcipifmtu; 499 if (rt->rt_ifp->if_flags & IFF_LINK0) 500 arcipifmtu = arc_ipmtu; 501 else 502 arcipifmtu = ARCMTU; 503 504 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 505 (rt->rt_rmx.rmx_mtu > arcipifmtu || 506 (rt->rt_rmx.rmx_mtu == 0 && 507 rt->rt_ifp->if_mtu > arcipifmtu))) 508 rt->rt_rmx.rmx_mtu = arcipifmtu; 509 break; 510 } 511 #endif 512 } 513 break; 514 } 515 /* Announce a new entry if requested. */ 516 if (rt->rt_flags & RTF_ANNOUNCE) 517 arprequest(rt->rt_ifp, 518 &SIN(rt_key(rt))->sin_addr, 519 &SIN(rt_key(rt))->sin_addr, 520 (u_char *)LLADDR(SDL(gate))); 521 /*FALLTHROUGH*/ 522 case RTM_RESOLVE: 523 if (gate->sa_family != AF_LINK || 524 gate->sa_len < sizeof(null_sdl)) { 525 log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n"); 526 break; 527 } 528 SDL(gate)->sdl_type = rt->rt_ifp->if_type; 529 SDL(gate)->sdl_index = rt->rt_ifp->if_index; 530 if (la != 0) 531 break; /* This happens on a route change */ 532 /* 533 * Case 2: This route may come from cloning, or a manual route 534 * add with a LL address. 535 */ 536 switch (SDL(gate)->sdl_type) { 537 #if NTOKEN > 0 538 case IFT_ISO88025: 539 allocsize = sizeof(*la) + sizeof(struct token_rif); 540 break; 541 #endif /* NTOKEN > 0 */ 542 default: 543 allocsize = sizeof(*la); 544 } 545 R_Malloc(la, struct llinfo_arp *, allocsize); 546 rt->rt_llinfo = (caddr_t)la; 547 if (la == 0) { 548 log(LOG_DEBUG, "arp_rtrequest: malloc failed\n"); 549 break; 550 } 551 arp_inuse++, arp_allocated++; 552 Bzero(la, allocsize); 553 la->la_rt = rt; 554 rt->rt_flags |= RTF_LLINFO; 555 LIST_INSERT_HEAD(&llinfo_arp, la, la_list); 556 557 INADDR_TO_IA(SIN(rt_key(rt))->sin_addr, ia); 558 while (ia && ia->ia_ifp != rt->rt_ifp) 559 NEXT_IA_WITH_SAME_ADDR(ia); 560 if (ia) { 561 /* 562 * This test used to be 563 * if (lo0ifp->if_flags & IFF_UP) 564 * It allowed local traffic to be forced through 565 * the hardware by configuring the loopback down. 566 * However, it causes problems during network 567 * configuration for boards that can't receive 568 * packets they send. It is now necessary to clear 569 * "useloopback" and remove the route to force 570 * traffic out to the hardware. 571 * 572 * In 4.4BSD, the above "if" statement checked 573 * rt->rt_ifa against rt_key(rt). It was changed 574 * to the current form so that we can provide a 575 * better support for multiple IPv4 addresses on a 576 * interface. 577 */ 578 rt->rt_expire = 0; 579 Bcopy(LLADDR(rt->rt_ifp->if_sadl), 580 LLADDR(SDL(gate)), 581 SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen); 582 if (useloopback) 583 rt->rt_ifp = lo0ifp; 584 /* 585 * make sure to set rt->rt_ifa to the interface 586 * address we are using, otherwise we will have trouble 587 * with source address selection. 588 */ 589 ifa = &ia->ia_ifa; 590 if (ifa != rt->rt_ifa) { 591 IFAFREE(rt->rt_ifa); 592 IFAREF(ifa); 593 rt->rt_ifa = ifa; 594 } 595 } 596 break; 597 598 case RTM_DELETE: 599 if (la == 0) 600 break; 601 arp_inuse--; 602 LIST_REMOVE(la, la_list); 603 rt->rt_llinfo = 0; 604 rt->rt_flags &= ~RTF_LLINFO; 605 606 s = splnet(); 607 mold = la->la_hold; 608 la->la_hold = 0; 609 splx(s); 610 611 if (mold) 612 m_freem(mold); 613 614 Free((caddr_t)la); 615 } 616 ARP_UNLOCK(); 617 } 618 619 /* 620 * Broadcast an ARP request. Caller specifies: 621 * - arp header source ip address 622 * - arp header target ip address 623 * - arp header source ethernet address 624 */ 625 void 626 arprequest(struct ifnet *ifp, 627 struct in_addr *sip, struct in_addr *tip, u_int8_t *enaddr) 628 { 629 struct mbuf *m; 630 struct arphdr *ah; 631 struct sockaddr sa; 632 633 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 634 return; 635 MCLAIM(m, &arpdomain.dom_mowner); 636 switch (ifp->if_type) { 637 case IFT_IEEE1394: 638 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 639 ifp->if_addrlen; 640 break; 641 default: 642 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 643 2 * ifp->if_addrlen; 644 break; 645 } 646 m->m_pkthdr.len = m->m_len; 647 MH_ALIGN(m, m->m_len); 648 ah = mtod(m, struct arphdr *); 649 bzero((caddr_t)ah, m->m_len); 650 switch (ifp->if_type) { 651 case IFT_IEEE1394: /* RFC2734 */ 652 /* fill it now for ar_tpa computation */ 653 ah->ar_hrd = htons(ARPHRD_IEEE1394); 654 break; 655 default: 656 /* ifp->if_output will fill ar_hrd */ 657 break; 658 } 659 ah->ar_pro = htons(ETHERTYPE_IP); 660 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 661 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 662 ah->ar_op = htons(ARPOP_REQUEST); 663 bcopy((caddr_t)enaddr, (caddr_t)ar_sha(ah), ah->ar_hln); 664 bcopy((caddr_t)sip, (caddr_t)ar_spa(ah), ah->ar_pln); 665 bcopy((caddr_t)tip, (caddr_t)ar_tpa(ah), ah->ar_pln); 666 sa.sa_family = AF_ARP; 667 sa.sa_len = 2; 668 m->m_flags |= M_BCAST; 669 arpstat.as_sndtotal++; 670 arpstat.as_sndrequest++; 671 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); 672 } 673 674 /* 675 * Resolve an IP address into an ethernet address. If success, 676 * desten is filled in. If there is no entry in arptab, 677 * set one up and broadcast a request for the IP address. 678 * Hold onto this mbuf and resend it once the address 679 * is finally resolved. A return value of 1 indicates 680 * that desten has been filled in and the packet should be sent 681 * normally; a 0 return indicates that the packet has been 682 * taken over here, either now or for later transmission. 683 */ 684 int 685 arpresolve(struct ifnet *ifp, struct rtentry *rt, struct mbuf *m, 686 struct sockaddr *dst, u_char *desten) 687 { 688 struct llinfo_arp *la; 689 struct sockaddr_dl *sdl; 690 struct mbuf *mold; 691 int s; 692 693 if (rt) 694 la = (struct llinfo_arp *)rt->rt_llinfo; 695 else { 696 if ((la = arplookup(m, &SIN(dst)->sin_addr, 1, 0)) != NULL) 697 rt = la->la_rt; 698 } 699 if (la == 0 || rt == 0) { 700 arpstat.as_allocfail++; 701 log(LOG_DEBUG, 702 "arpresolve: can't allocate llinfo on %s for %s\n", 703 ifp->if_xname, in_fmtaddr(SIN(dst)->sin_addr)); 704 m_freem(m); 705 return (0); 706 } 707 sdl = SDL(rt->rt_gateway); 708 /* 709 * Check the address family and length is valid, the address 710 * is resolved; otherwise, try to resolve. 711 */ 712 if ((rt->rt_expire == 0 || rt->rt_expire > time_second) && 713 sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) { 714 bcopy(LLADDR(sdl), desten, 715 min(sdl->sdl_alen, ifp->if_addrlen)); 716 rt->rt_pksent = time_second; /* Time for last pkt sent */ 717 return 1; 718 } 719 /* 720 * There is an arptab entry, but no ethernet address 721 * response yet. Replace the held mbuf with this 722 * latest one. 723 */ 724 725 arpstat.as_dfrtotal++; 726 s = splnet(); 727 mold = la->la_hold; 728 la->la_hold = m; 729 splx(s); 730 731 if (mold) { 732 arpstat.as_dfrdropped++; 733 m_freem(mold); 734 } 735 736 /* 737 * Re-send the ARP request when appropriate. 738 */ 739 #ifdef DIAGNOSTIC 740 if (rt->rt_expire == 0) { 741 /* This should never happen. (Should it? -gwr) */ 742 printf("arpresolve: unresolved and rt_expire == 0\n"); 743 /* Set expiration time to now (expired). */ 744 rt->rt_expire = time_second; 745 } 746 #endif 747 if (rt->rt_expire) { 748 rt->rt_flags &= ~RTF_REJECT; 749 if (la->la_asked == 0 || rt->rt_expire != time_second) { 750 rt->rt_expire = time_second; 751 if (la->la_asked++ < arp_maxtries) 752 arprequest(ifp, 753 &SIN(rt->rt_ifa->ifa_addr)->sin_addr, 754 &SIN(dst)->sin_addr, 755 #if NCARP > 0 756 (rt->rt_ifp->if_type == IFT_CARP) ? 757 LLADDR(rt->rt_ifp->if_sadl): 758 #endif 759 LLADDR(ifp->if_sadl)); 760 else { 761 rt->rt_flags |= RTF_REJECT; 762 rt->rt_expire += arpt_down; 763 la->la_asked = 0; 764 } 765 } 766 } 767 return (0); 768 } 769 770 /* 771 * Common length and type checks are done here, 772 * then the protocol-specific routine is called. 773 */ 774 void 775 arpintr(void) 776 { 777 struct mbuf *m; 778 struct arphdr *ar; 779 int s; 780 int arplen; 781 782 while (arpintrq.ifq_head) { 783 s = splnet(); 784 IF_DEQUEUE(&arpintrq, m); 785 splx(s); 786 if (m == 0 || (m->m_flags & M_PKTHDR) == 0) 787 panic("arpintr"); 788 789 MCLAIM(m, &arpdomain.dom_mowner); 790 arpstat.as_rcvtotal++; 791 792 /* 793 * First, make sure we have at least struct arphdr. 794 */ 795 if (m->m_len < sizeof(struct arphdr) || 796 (ar = mtod(m, struct arphdr *)) == NULL) 797 goto badlen; 798 799 switch (m->m_pkthdr.rcvif->if_type) { 800 case IFT_IEEE1394: 801 arplen = sizeof(struct arphdr) + 802 ar->ar_hln + 2 * ar->ar_pln; 803 break; 804 default: 805 arplen = sizeof(struct arphdr) + 806 2 * ar->ar_hln + 2 * ar->ar_pln; 807 break; 808 } 809 810 if (/* XXX ntohs(ar->ar_hrd) == ARPHRD_ETHER && */ 811 m->m_len >= arplen) 812 switch (ntohs(ar->ar_pro)) { 813 case ETHERTYPE_IP: 814 case ETHERTYPE_IPTRAILERS: 815 in_arpinput(m); 816 continue; 817 default: 818 arpstat.as_rcvbadproto++; 819 } 820 else { 821 badlen: 822 arpstat.as_rcvbadlen++; 823 } 824 m_freem(m); 825 } 826 } 827 828 /* 829 * ARP for Internet protocols on 10 Mb/s Ethernet. 830 * Algorithm is that given in RFC 826. 831 * In addition, a sanity check is performed on the sender 832 * protocol address, to catch impersonators. 833 * We no longer handle negotiations for use of trailer protocol: 834 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent 835 * along with IP replies if we wanted trailers sent to us, 836 * and also sent them in response to IP replies. 837 * This allowed either end to announce the desire to receive 838 * trailer packets. 839 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, 840 * but formerly didn't normally send requests. 841 */ 842 static void 843 in_arpinput(struct mbuf *m) 844 { 845 struct arphdr *ah; 846 struct ifnet *ifp = m->m_pkthdr.rcvif; 847 struct llinfo_arp *la = 0; 848 struct rtentry *rt; 849 struct in_ifaddr *ia; 850 #if NBRIDGE > 0 851 struct in_ifaddr *bridge_ia = NULL; 852 #endif 853 #if NCARP > 0 854 u_int32_t count = 0, index = 0; 855 #endif 856 struct sockaddr_dl *sdl; 857 struct sockaddr sa; 858 struct in_addr isaddr, itaddr, myaddr; 859 int op; 860 struct mbuf *mold; 861 caddr_t tha; 862 int s; 863 864 if (__predict_false(m_makewritable(&m, 0, m->m_pkthdr.len, M_DONTWAIT))) 865 goto out; 866 ah = mtod(m, struct arphdr *); 867 op = ntohs(ah->ar_op); 868 869 /* 870 * Fix up ah->ar_hrd if necessary, before using ar_tha() or 871 * ar_tpa(). 872 */ 873 switch (ifp->if_type) { 874 case IFT_IEEE1394: 875 if (ntohs(ah->ar_hrd) == ARPHRD_IEEE1394) 876 ; 877 else { 878 /* XXX this is to make sure we compute ar_tha right */ 879 /* XXX check ar_hrd more strictly? */ 880 ah->ar_hrd = htons(ARPHRD_IEEE1394); 881 } 882 break; 883 default: 884 /* XXX check ar_hrd? */ 885 break; 886 } 887 888 bcopy((caddr_t)ar_spa(ah), (caddr_t)&isaddr, sizeof (isaddr)); 889 bcopy((caddr_t)ar_tpa(ah), (caddr_t)&itaddr, sizeof (itaddr)); 890 891 if (m->m_flags & (M_BCAST|M_MCAST)) 892 arpstat.as_rcvmcast++; 893 894 /* 895 * If the target IP address is zero, ignore the packet. 896 * This prevents the code below from tring to answer 897 * when we are using IP address zero (booting). 898 */ 899 if (in_nullhost(itaddr)) { 900 arpstat.as_rcvzerotpa++; 901 goto out; 902 } 903 904 /* 905 * If the source IP address is zero, this is most likely a 906 * confused host trying to use IP address zero. (Windoze?) 907 * XXX: Should we bother trying to reply to these? 908 */ 909 if (in_nullhost(isaddr)) { 910 arpstat.as_rcvzerospa++; 911 goto out; 912 } 913 914 /* 915 * Search for a matching interface address 916 * or any address on the interface to use 917 * as a dummy address in the rest of this function 918 */ 919 920 INADDR_TO_IA(itaddr, ia); 921 while (ia != NULL) { 922 #if NCARP > 0 923 if (ia->ia_ifp->if_type == IFT_CARP && 924 ((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) == 925 (IFF_UP|IFF_RUNNING))) { 926 index++; 927 if (ia->ia_ifp == m->m_pkthdr.rcvif && 928 carp_iamatch(ia, ar_sha(ah), 929 &count, index)) { 930 break; 931 } 932 } else 933 #endif 934 if (ia->ia_ifp == m->m_pkthdr.rcvif) 935 break; 936 #if NBRIDGE > 0 937 /* 938 * If the interface we received the packet on 939 * is part of a bridge, check to see if we need 940 * to "bridge" the packet to ourselves at this 941 * layer. Note we still prefer a perfect match, 942 * but allow this weaker match if necessary. 943 */ 944 if (m->m_pkthdr.rcvif->if_bridge != NULL && 945 m->m_pkthdr.rcvif->if_bridge == ia->ia_ifp->if_bridge) 946 bridge_ia = ia; 947 #endif /* NBRIDGE > 0 */ 948 949 NEXT_IA_WITH_SAME_ADDR(ia); 950 } 951 952 #if NBRIDGE > 0 953 if (ia == NULL && bridge_ia != NULL) { 954 ia = bridge_ia; 955 ifp = bridge_ia->ia_ifp; 956 } 957 #endif 958 959 if (ia == NULL) { 960 INADDR_TO_IA(isaddr, ia); 961 while ((ia != NULL) && ia->ia_ifp != m->m_pkthdr.rcvif) 962 NEXT_IA_WITH_SAME_ADDR(ia); 963 964 if (ia == NULL) { 965 IFP_TO_IA(ifp, ia); 966 if (ia == NULL) { 967 arpstat.as_rcvnoint++; 968 goto out; 969 } 970 } 971 } 972 973 myaddr = ia->ia_addr.sin_addr; 974 975 /* XXX checks for bridge case? */ 976 if (!bcmp((caddr_t)ar_sha(ah), LLADDR(ifp->if_sadl), 977 ifp->if_addrlen)) { 978 arpstat.as_rcvlocalsha++; 979 goto out; /* it's from me, ignore it. */ 980 } 981 982 /* XXX checks for bridge case? */ 983 if (!memcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 984 arpstat.as_rcvbcastsha++; 985 log(LOG_ERR, 986 "%s: arp: link address is broadcast for IP address %s!\n", 987 ifp->if_xname, in_fmtaddr(isaddr)); 988 goto out; 989 } 990 991 if (in_hosteq(isaddr, myaddr)) { 992 arpstat.as_rcvlocalspa++; 993 log(LOG_ERR, 994 "duplicate IP address %s sent from link address %s\n", 995 in_fmtaddr(isaddr), lla_snprintf(ar_sha(ah), ah->ar_hln)); 996 itaddr = myaddr; 997 goto reply; 998 } 999 la = arplookup(m, &isaddr, in_hosteq(itaddr, myaddr), 0); 1000 if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) { 1001 if (sdl->sdl_alen && 1002 bcmp((caddr_t)ar_sha(ah), LLADDR(sdl), sdl->sdl_alen)) { 1003 if (rt->rt_flags & RTF_STATIC) { 1004 arpstat.as_rcvoverperm++; 1005 log(LOG_INFO, 1006 "%s tried to overwrite permanent arp info" 1007 " for %s\n", 1008 lla_snprintf(ar_sha(ah), ah->ar_hln), 1009 in_fmtaddr(isaddr)); 1010 goto out; 1011 } else if (rt->rt_ifp != ifp) { 1012 arpstat.as_rcvoverint++; 1013 log(LOG_INFO, 1014 "%s on %s tried to overwrite " 1015 "arp info for %s on %s\n", 1016 lla_snprintf(ar_sha(ah), ah->ar_hln), 1017 ifp->if_xname, in_fmtaddr(isaddr), 1018 rt->rt_ifp->if_xname); 1019 goto out; 1020 } else { 1021 arpstat.as_rcvover++; 1022 log(LOG_INFO, 1023 "arp info overwritten for %s by %s\n", 1024 in_fmtaddr(isaddr), 1025 lla_snprintf(ar_sha(ah), ah->ar_hln)); 1026 } 1027 } 1028 /* 1029 * sanity check for the address length. 1030 * XXX this does not work for protocols with variable address 1031 * length. -is 1032 */ 1033 if (sdl->sdl_alen && 1034 sdl->sdl_alen != ah->ar_hln) { 1035 arpstat.as_rcvlenchg++; 1036 log(LOG_WARNING, 1037 "arp from %s: new addr len %d, was %d", 1038 in_fmtaddr(isaddr), ah->ar_hln, sdl->sdl_alen); 1039 } 1040 if (ifp->if_addrlen != ah->ar_hln) { 1041 arpstat.as_rcvbadlen++; 1042 log(LOG_WARNING, 1043 "arp from %s: addr len: new %d, i/f %d (ignored)", 1044 in_fmtaddr(isaddr), ah->ar_hln, 1045 ifp->if_addrlen); 1046 goto reply; 1047 } 1048 #if NTOKEN > 0 1049 /* 1050 * XXX uses m_data and assumes the complete answer including 1051 * XXX token-ring headers is in the same buf 1052 */ 1053 if (ifp->if_type == IFT_ISO88025) { 1054 struct token_header *trh; 1055 1056 trh = (struct token_header *)M_TRHSTART(m); 1057 if (trh->token_shost[0] & TOKEN_RI_PRESENT) { 1058 struct token_rif *rif; 1059 size_t riflen; 1060 1061 rif = TOKEN_RIF(trh); 1062 riflen = (ntohs(rif->tr_rcf) & 1063 TOKEN_RCF_LEN_MASK) >> 8; 1064 1065 if (riflen > 2 && 1066 riflen < sizeof(struct token_rif) && 1067 (riflen & 1) == 0) { 1068 rif->tr_rcf ^= htons(TOKEN_RCF_DIRECTION); 1069 rif->tr_rcf &= htons(~TOKEN_RCF_BROADCAST_MASK); 1070 bcopy(rif, TOKEN_RIF(la), riflen); 1071 } 1072 } 1073 } 1074 #endif /* NTOKEN > 0 */ 1075 bcopy((caddr_t)ar_sha(ah), LLADDR(sdl), 1076 sdl->sdl_alen = ah->ar_hln); 1077 if (rt->rt_expire) 1078 rt->rt_expire = time_second + arpt_keep; 1079 rt->rt_flags &= ~RTF_REJECT; 1080 la->la_asked = 0; 1081 1082 s = splnet(); 1083 mold = la->la_hold; 1084 la->la_hold = 0; 1085 splx(s); 1086 1087 if (mold) { 1088 arpstat.as_dfrsent++; 1089 (*ifp->if_output)(ifp, mold, rt_key(rt), rt); 1090 } 1091 } 1092 reply: 1093 if (op != ARPOP_REQUEST) { 1094 if (op == ARPOP_REPLY) 1095 arpstat.as_rcvreply++; 1096 out: 1097 m_freem(m); 1098 return; 1099 } 1100 arpstat.as_rcvrequest++; 1101 if (in_hosteq(itaddr, myaddr)) { 1102 /* I am the target */ 1103 tha = ar_tha(ah); 1104 if (tha) 1105 bcopy((caddr_t)ar_sha(ah), tha, ah->ar_hln); 1106 bcopy(LLADDR(ifp->if_sadl), (caddr_t)ar_sha(ah), ah->ar_hln); 1107 } else { 1108 la = arplookup(m, &itaddr, 0, SIN_PROXY); 1109 if (la == 0) 1110 goto out; 1111 rt = la->la_rt; 1112 if (rt->rt_ifp->if_type == IFT_CARP && 1113 m->m_pkthdr.rcvif->if_type != IFT_CARP) 1114 goto out; 1115 tha = ar_tha(ah); 1116 if (tha) 1117 bcopy((caddr_t)ar_sha(ah), tha, ah->ar_hln); 1118 sdl = SDL(rt->rt_gateway); 1119 bcopy(LLADDR(sdl), (caddr_t)ar_sha(ah), ah->ar_hln); 1120 } 1121 1122 bcopy((caddr_t)ar_spa(ah), (caddr_t)ar_tpa(ah), ah->ar_pln); 1123 bcopy((caddr_t)&itaddr, (caddr_t)ar_spa(ah), ah->ar_pln); 1124 ah->ar_op = htons(ARPOP_REPLY); 1125 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 1126 switch (ifp->if_type) { 1127 case IFT_IEEE1394: 1128 /* 1129 * ieee1394 arp reply is broadcast 1130 */ 1131 m->m_flags &= ~M_MCAST; 1132 m->m_flags |= M_BCAST; 1133 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + ah->ar_hln; 1134 break; 1135 1136 default: 1137 m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */ 1138 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); 1139 break; 1140 } 1141 m->m_pkthdr.len = m->m_len; 1142 sa.sa_family = AF_ARP; 1143 sa.sa_len = 2; 1144 arpstat.as_sndtotal++; 1145 arpstat.as_sndreply++; 1146 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); 1147 return; 1148 } 1149 1150 /* 1151 * Free an arp entry. 1152 */ 1153 static void arptfree(struct llinfo_arp *la) 1154 { 1155 struct rtentry *rt = la->la_rt; 1156 struct sockaddr_dl *sdl; 1157 1158 ARP_LOCK_CHECK(); 1159 1160 if (rt == 0) 1161 panic("arptfree"); 1162 if (rt->rt_refcnt > 0 && (sdl = SDL(rt->rt_gateway)) && 1163 sdl->sdl_family == AF_LINK) { 1164 sdl->sdl_alen = 0; 1165 la->la_asked = 0; 1166 rt->rt_flags &= ~RTF_REJECT; 1167 return; 1168 } 1169 rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0, rt_mask(rt), 1170 0, (struct rtentry **)0); 1171 } 1172 1173 /* 1174 * Lookup or enter a new address in arptab. 1175 */ 1176 static struct llinfo_arp * 1177 arplookup(struct mbuf *m, struct in_addr *addr, int create, int proxy) 1178 { 1179 struct arphdr *ah; 1180 struct ifnet *ifp = m->m_pkthdr.rcvif; 1181 struct rtentry *rt; 1182 static struct sockaddr_inarp sin; 1183 const char *why = 0; 1184 1185 ah = mtod(m, struct arphdr *); 1186 sin.sin_len = sizeof(sin); 1187 sin.sin_family = AF_INET; 1188 sin.sin_addr = *addr; 1189 sin.sin_other = proxy ? SIN_PROXY : 0; 1190 rt = rtalloc1(sintosa(&sin), create); 1191 if (rt == 0) 1192 return (0); 1193 rt->rt_refcnt--; 1194 1195 if ((rt->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) == RTF_LLINFO && 1196 rt->rt_gateway->sa_family == AF_LINK) 1197 return ((struct llinfo_arp *)rt->rt_llinfo); 1198 1199 1200 1201 if (create) { 1202 if (rt->rt_flags & RTF_GATEWAY) 1203 why = "host is not on local network"; 1204 else if ((rt->rt_flags & RTF_LLINFO) == 0) { 1205 arpstat.as_allocfail++; 1206 why = "could not allocate llinfo"; 1207 } else 1208 why = "gateway route is not ours"; 1209 log(LOG_DEBUG, "arplookup: unable to enter address" 1210 " for %s@%s on %s (%s)\n", 1211 in_fmtaddr(*addr), lla_snprintf(ar_sha(ah), ah->ar_hln), 1212 (ifp) ? ifp->if_xname : 0, why); 1213 if (rt->rt_refcnt <= 0 && (rt->rt_flags & RTF_CLONED) != 0) { 1214 rtrequest(RTM_DELETE, (struct sockaddr *)rt_key(rt), 1215 rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0); 1216 } 1217 } 1218 return (0); 1219 } 1220 1221 int 1222 arpioctl(u_long cmd __unused, caddr_t data __unused) 1223 { 1224 1225 return (EOPNOTSUPP); 1226 } 1227 1228 void 1229 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1230 { 1231 struct in_addr *ip; 1232 1233 /* 1234 * Warn the user if another station has this IP address, 1235 * but only if the interface IP address is not zero. 1236 */ 1237 ip = &IA_SIN(ifa)->sin_addr; 1238 if (!in_nullhost(*ip)) 1239 arprequest(ifp, ip, ip, LLADDR(ifp->if_sadl)); 1240 1241 ifa->ifa_rtrequest = arp_rtrequest; 1242 ifa->ifa_flags |= RTF_CLONING; 1243 } 1244 1245 /* 1246 * Called from 10 Mb/s Ethernet interrupt handlers 1247 * when ether packet type ETHERTYPE_REVARP 1248 * is received. Common length and type checks are done here, 1249 * then the protocol-specific routine is called. 1250 */ 1251 void 1252 revarpinput(struct mbuf *m) 1253 { 1254 struct arphdr *ar; 1255 1256 if (m->m_len < sizeof(struct arphdr)) 1257 goto out; 1258 ar = mtod(m, struct arphdr *); 1259 #if 0 /* XXX I don't think we need this... and it will prevent other LL */ 1260 if (ntohs(ar->ar_hrd) != ARPHRD_ETHER) 1261 goto out; 1262 #endif 1263 if (m->m_len < sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln)) 1264 goto out; 1265 switch (ntohs(ar->ar_pro)) { 1266 case ETHERTYPE_IP: 1267 case ETHERTYPE_IPTRAILERS: 1268 in_revarpinput(m); 1269 return; 1270 1271 default: 1272 break; 1273 } 1274 out: 1275 m_freem(m); 1276 } 1277 1278 /* 1279 * RARP for Internet protocols on 10 Mb/s Ethernet. 1280 * Algorithm is that given in RFC 903. 1281 * We are only using for bootstrap purposes to get an ip address for one of 1282 * our interfaces. Thus we support no user-interface. 1283 * 1284 * Since the contents of the RARP reply are specific to the interface that 1285 * sent the request, this code must ensure that they are properly associated. 1286 * 1287 * Note: also supports ARP via RARP packets, per the RFC. 1288 */ 1289 void 1290 in_revarpinput(struct mbuf *m) 1291 { 1292 struct ifnet *ifp; 1293 struct arphdr *ah; 1294 caddr_t tha; 1295 int op; 1296 1297 ah = mtod(m, struct arphdr *); 1298 op = ntohs(ah->ar_op); 1299 1300 switch (m->m_pkthdr.rcvif->if_type) { 1301 case IFT_IEEE1394: 1302 /* ARP without target hardware address is not supported */ 1303 goto out; 1304 default: 1305 break; 1306 } 1307 1308 switch (op) { 1309 case ARPOP_REQUEST: 1310 case ARPOP_REPLY: /* per RFC */ 1311 in_arpinput(m); 1312 return; 1313 case ARPOP_REVREPLY: 1314 break; 1315 case ARPOP_REVREQUEST: /* handled by rarpd(8) */ 1316 default: 1317 goto out; 1318 } 1319 if (!revarp_in_progress) 1320 goto out; 1321 ifp = m->m_pkthdr.rcvif; 1322 if (ifp != myip_ifp) /* !same interface */ 1323 goto out; 1324 if (myip_initialized) 1325 goto wake; 1326 tha = ar_tha(ah); 1327 KASSERT(tha); 1328 if (bcmp(tha, LLADDR(ifp->if_sadl), ifp->if_sadl->sdl_alen)) 1329 goto out; 1330 bcopy((caddr_t)ar_spa(ah), (caddr_t)&srv_ip, sizeof(srv_ip)); 1331 bcopy((caddr_t)ar_tpa(ah), (caddr_t)&myip, sizeof(myip)); 1332 myip_initialized = 1; 1333 wake: /* Do wakeup every time in case it was missed. */ 1334 wakeup((caddr_t)&myip); 1335 1336 out: 1337 m_freem(m); 1338 } 1339 1340 /* 1341 * Send a RARP request for the ip address of the specified interface. 1342 * The request should be RFC 903-compliant. 1343 */ 1344 void 1345 revarprequest(struct ifnet *ifp) 1346 { 1347 struct sockaddr sa; 1348 struct mbuf *m; 1349 struct arphdr *ah; 1350 caddr_t tha; 1351 1352 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 1353 return; 1354 MCLAIM(m, &arpdomain.dom_mowner); 1355 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) + 1356 2*ifp->if_addrlen; 1357 m->m_pkthdr.len = m->m_len; 1358 MH_ALIGN(m, m->m_len); 1359 ah = mtod(m, struct arphdr *); 1360 bzero((caddr_t)ah, m->m_len); 1361 ah->ar_pro = htons(ETHERTYPE_IP); 1362 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 1363 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 1364 ah->ar_op = htons(ARPOP_REVREQUEST); 1365 1366 bcopy(LLADDR(ifp->if_sadl), (caddr_t)ar_sha(ah), ah->ar_hln); 1367 tha = ar_tha(ah); 1368 KASSERT(tha); 1369 bcopy(LLADDR(ifp->if_sadl), tha, ah->ar_hln); 1370 1371 sa.sa_family = AF_ARP; 1372 sa.sa_len = 2; 1373 m->m_flags |= M_BCAST; 1374 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); 1375 1376 } 1377 1378 /* 1379 * RARP for the ip address of the specified interface, but also 1380 * save the ip address of the server that sent the answer. 1381 * Timeout if no response is received. 1382 */ 1383 int 1384 revarpwhoarewe(struct ifnet *ifp, struct in_addr *serv_in, 1385 struct in_addr *clnt_in) 1386 { 1387 int result, count = 20; 1388 1389 myip_initialized = 0; 1390 myip_ifp = ifp; 1391 1392 revarp_in_progress = 1; 1393 while (count--) { 1394 revarprequest(ifp); 1395 result = tsleep((caddr_t)&myip, PSOCK, "revarp", hz/2); 1396 if (result != EWOULDBLOCK) 1397 break; 1398 } 1399 revarp_in_progress = 0; 1400 1401 if (!myip_initialized) 1402 return ENETUNREACH; 1403 1404 bcopy((caddr_t)&srv_ip, serv_in, sizeof(*serv_in)); 1405 bcopy((caddr_t)&myip, clnt_in, sizeof(*clnt_in)); 1406 return 0; 1407 } 1408 1409 1410 1411 #ifdef DDB 1412 1413 #include <machine/db_machdep.h> 1414 #include <ddb/db_interface.h> 1415 #include <ddb/db_output.h> 1416 1417 static void 1418 db_print_sa(const struct sockaddr *sa) 1419 { 1420 int len; 1421 const u_char *p; 1422 1423 if (sa == 0) { 1424 db_printf("[NULL]"); 1425 return; 1426 } 1427 1428 p = (const u_char *)sa; 1429 len = sa->sa_len; 1430 db_printf("["); 1431 while (len > 0) { 1432 db_printf("%d", *p); 1433 p++; len--; 1434 if (len) db_printf(","); 1435 } 1436 db_printf("]\n"); 1437 } 1438 1439 static void 1440 db_print_ifa(struct ifaddr *ifa) 1441 { 1442 if (ifa == 0) 1443 return; 1444 db_printf(" ifa_addr="); 1445 db_print_sa(ifa->ifa_addr); 1446 db_printf(" ifa_dsta="); 1447 db_print_sa(ifa->ifa_dstaddr); 1448 db_printf(" ifa_mask="); 1449 db_print_sa(ifa->ifa_netmask); 1450 db_printf(" flags=0x%x,refcnt=%d,metric=%d\n", 1451 ifa->ifa_flags, 1452 ifa->ifa_refcnt, 1453 ifa->ifa_metric); 1454 } 1455 1456 static void 1457 db_print_llinfo(caddr_t li) 1458 { 1459 struct llinfo_arp *la; 1460 1461 if (li == 0) 1462 return; 1463 la = (struct llinfo_arp *)li; 1464 db_printf(" la_rt=%p la_hold=%p, la_asked=0x%lx\n", 1465 la->la_rt, la->la_hold, la->la_asked); 1466 } 1467 1468 /* 1469 * Function to pass to rn_walktree(). 1470 * Return non-zero error to abort walk. 1471 */ 1472 static int 1473 db_show_radix_node(struct radix_node *rn, void *w __unused) 1474 { 1475 struct rtentry *rt = (struct rtentry *)rn; 1476 1477 db_printf("rtentry=%p", rt); 1478 1479 db_printf(" flags=0x%x refcnt=%d use=%ld expire=%ld\n", 1480 rt->rt_flags, rt->rt_refcnt, 1481 rt->rt_use, rt->rt_expire); 1482 1483 db_printf(" key="); db_print_sa(rt_key(rt)); 1484 db_printf(" mask="); db_print_sa(rt_mask(rt)); 1485 db_printf(" gw="); db_print_sa(rt->rt_gateway); 1486 1487 db_printf(" ifp=%p ", rt->rt_ifp); 1488 if (rt->rt_ifp) 1489 db_printf("(%s)", rt->rt_ifp->if_xname); 1490 else 1491 db_printf("(NULL)"); 1492 1493 db_printf(" ifa=%p\n", rt->rt_ifa); 1494 db_print_ifa(rt->rt_ifa); 1495 1496 db_printf(" genmask="); db_print_sa(rt->rt_genmask); 1497 1498 db_printf(" gwroute=%p llinfo=%p\n", 1499 rt->rt_gwroute, rt->rt_llinfo); 1500 db_print_llinfo(rt->rt_llinfo); 1501 1502 return (0); 1503 } 1504 1505 /* 1506 * Function to print all the route trees. 1507 * Use this from ddb: "show arptab" 1508 */ 1509 void 1510 db_show_arptab(db_expr_t addr __unused, int have_addr __unused, 1511 db_expr_t count __unused, const char *modif __unused) 1512 { 1513 struct radix_node_head *rnh; 1514 rnh = rt_tables[AF_INET]; 1515 db_printf("Route tree for AF_INET\n"); 1516 if (rnh == NULL) { 1517 db_printf(" (not initialized)\n"); 1518 return; 1519 } 1520 rn_walktree(rnh, db_show_radix_node, NULL); 1521 return; 1522 } 1523 #endif 1524 1525 SYSCTL_SETUP(sysctl_net_inet_arp_setup, "sysctl net.inet.arp subtree setup") 1526 { 1527 const struct sysctlnode *node; 1528 1529 sysctl_createv(clog, 0, NULL, NULL, 1530 CTLFLAG_PERMANENT, 1531 CTLTYPE_NODE, "net", NULL, 1532 NULL, 0, NULL, 0, 1533 CTL_NET, CTL_EOL); 1534 sysctl_createv(clog, 0, NULL, NULL, 1535 CTLFLAG_PERMANENT, 1536 CTLTYPE_NODE, "inet", NULL, 1537 NULL, 0, NULL, 0, 1538 CTL_NET, PF_INET, CTL_EOL); 1539 sysctl_createv(clog, 0, NULL, &node, 1540 CTLFLAG_PERMANENT, 1541 CTLTYPE_NODE, "arp", 1542 SYSCTL_DESCR("Address Resolution Protocol"), 1543 NULL, 0, NULL, 0, 1544 CTL_NET, PF_INET, CTL_CREATE, CTL_EOL); 1545 1546 sysctl_createv(clog, 0, NULL, NULL, 1547 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1548 CTLTYPE_INT, "prune", 1549 SYSCTL_DESCR("ARP cache pruning interval"), 1550 NULL, 0, &arpt_prune, 0, 1551 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1552 1553 sysctl_createv(clog, 0, NULL, NULL, 1554 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1555 CTLTYPE_INT, "keep", 1556 SYSCTL_DESCR("Valid ARP entry lifetime"), 1557 NULL, 0, &arpt_keep, 0, 1558 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1559 1560 sysctl_createv(clog, 0, NULL, NULL, 1561 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1562 CTLTYPE_INT, "down", 1563 SYSCTL_DESCR("Failed ARP entry lifetime"), 1564 NULL, 0, &arpt_down, 0, 1565 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1566 1567 sysctl_createv(clog, 0, NULL, NULL, 1568 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1569 CTLTYPE_INT, "refresh", 1570 SYSCTL_DESCR("ARP entry refresh interval"), 1571 NULL, 0, &arpt_refresh, 0, 1572 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1573 } 1574 1575 #endif /* INET */ 1576