1 /* $NetBSD: if_arp.c,v 1.106 2005/06/20 02:49:18 atatat 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 1.106 2005/06/20 02:49:18 atatat 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/kernel.h> 95 #include <sys/errno.h> 96 #include <sys/ioctl.h> 97 #include <sys/syslog.h> 98 #include <sys/proc.h> 99 #include <sys/protosw.h> 100 #include <sys/domain.h> 101 #include <sys/sysctl.h> 102 103 #include <net/ethertypes.h> 104 #include <net/if.h> 105 #include <net/if_dl.h> 106 #include <net/if_token.h> 107 #include <net/if_types.h> 108 #include <net/route.h> 109 110 #include <netinet/in.h> 111 #include <netinet/in_systm.h> 112 #include <netinet/in_var.h> 113 #include <netinet/ip.h> 114 #include <netinet/if_inarp.h> 115 116 #include "arc.h" 117 #if NARC > 0 118 #include <net/if_arc.h> 119 #endif 120 #include "fddi.h" 121 #if NFDDI > 0 122 #include <net/if_fddi.h> 123 #endif 124 #include "token.h" 125 126 #define SIN(s) ((struct sockaddr_in *)s) 127 #define SDL(s) ((struct sockaddr_dl *)s) 128 #define SRP(s) ((struct sockaddr_inarp *)s) 129 130 /* 131 * ARP trailer negotiation. Trailer protocol is not IP specific, 132 * but ARP request/response use IP addresses. 133 */ 134 #define ETHERTYPE_IPTRAILERS ETHERTYPE_TRAIL 135 136 /* timer values */ 137 int arpt_prune = (5*60*1); /* walk list every 5 minutes */ 138 int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */ 139 int arpt_down = 20; /* once declared down, don't send for 20 secs */ 140 int arpt_refresh = (5*60); /* time left before refreshing */ 141 #define rt_expire rt_rmx.rmx_expire 142 #define rt_pksent rt_rmx.rmx_pksent 143 144 static void arprequest(struct ifnet *, 145 struct in_addr *, struct in_addr *, u_int8_t *); 146 static void arptfree(struct llinfo_arp *); 147 static void arptimer(void *); 148 static struct llinfo_arp *arplookup(struct mbuf *, struct in_addr *, 149 int, int); 150 static void in_arpinput(struct mbuf *); 151 152 LIST_HEAD(, llinfo_arp) llinfo_arp; 153 struct ifqueue arpintrq = {0, 0, 0, 50}; 154 int arp_inuse, arp_allocated, arp_intimer; 155 int arp_maxtries = 5; 156 int useloopback = 1; /* use loopback interface for local traffic */ 157 int arpinit_done = 0; 158 159 struct arpstat arpstat; 160 struct callout arptimer_ch; 161 162 163 /* revarp state */ 164 static struct in_addr myip, srv_ip; 165 static int myip_initialized = 0; 166 static int revarp_in_progress = 0; 167 static struct ifnet *myip_ifp = NULL; 168 169 #ifdef DDB 170 static void db_print_sa(const struct sockaddr *); 171 static void db_print_ifa(struct ifaddr *); 172 static void db_print_llinfo(caddr_t); 173 static int db_show_radix_node(struct radix_node *, void *); 174 #endif 175 176 /* 177 * this should be elsewhere. 178 */ 179 180 static char * 181 lla_snprintf(u_int8_t *, int); 182 183 static char * 184 lla_snprintf(u_int8_t *adrp, int len) 185 { 186 #define NUMBUFS 3 187 static char buf[NUMBUFS][16*3]; 188 static int bnum = 0; 189 190 int i; 191 char *p; 192 193 p = buf[bnum]; 194 195 *p++ = hexdigits[(*adrp)>>4]; 196 *p++ = hexdigits[(*adrp++)&0xf]; 197 198 for (i=1; i<len && i<16; i++) { 199 *p++ = ':'; 200 *p++ = hexdigits[(*adrp)>>4]; 201 *p++ = hexdigits[(*adrp++)&0xf]; 202 } 203 204 *p = 0; 205 p = buf[bnum]; 206 bnum = (bnum + 1) % NUMBUFS; 207 return p; 208 } 209 210 DOMAIN_DEFINE(arpdomain); /* forward declare and add to link set */ 211 212 const struct protosw arpsw[] = { 213 { 0, &arpdomain, 0, 0, 214 0, 0, 0, 0, 215 0, 216 0, 0, 0, arp_drain, 217 } 218 }; 219 220 221 struct domain arpdomain = 222 { PF_ARP, "arp", 0, 0, 0, 223 arpsw, &arpsw[sizeof(arpsw)/sizeof(arpsw[0])] 224 }; 225 226 /* 227 * ARP table locking. 228 * 229 * to prevent lossage vs. the arp_drain routine (which may be called at 230 * any time, including in a device driver context), we do two things: 231 * 232 * 1) manipulation of la->la_hold is done at splnet() (for all of 233 * about two instructions). 234 * 235 * 2) manipulation of the arp table's linked list is done under the 236 * protection of the ARP_LOCK; if arp_drain() or arptimer is called 237 * while the arp table is locked, we punt and try again later. 238 */ 239 240 static int arp_locked; 241 static __inline int arp_lock_try(int); 242 static __inline void arp_unlock(void); 243 244 static __inline int 245 arp_lock_try(int recurse) 246 { 247 int s; 248 249 /* 250 * Use splvm() -- we're blocking things that would cause 251 * mbuf allocation. 252 */ 253 s = splvm(); 254 if (!recurse && arp_locked) { 255 splx(s); 256 return (0); 257 } 258 arp_locked++; 259 splx(s); 260 return (1); 261 } 262 263 static __inline void 264 arp_unlock(void) 265 { 266 int s; 267 268 s = splvm(); 269 arp_locked--; 270 splx(s); 271 } 272 273 #ifdef DIAGNOSTIC 274 #define ARP_LOCK(recurse) \ 275 do { \ 276 if (arp_lock_try(recurse) == 0) { \ 277 printf("%s:%d: arp already locked\n", __FILE__, __LINE__); \ 278 panic("arp_lock"); \ 279 } \ 280 } while (/*CONSTCOND*/ 0) 281 #define ARP_LOCK_CHECK() \ 282 do { \ 283 if (arp_locked == 0) { \ 284 printf("%s:%d: arp lock not held\n", __FILE__, __LINE__); \ 285 panic("arp lock check"); \ 286 } \ 287 } while (/*CONSTCOND*/ 0) 288 #else 289 #define ARP_LOCK(x) (void) arp_lock_try(x) 290 #define ARP_LOCK_CHECK() /* nothing */ 291 #endif 292 293 #define ARP_UNLOCK() arp_unlock() 294 295 /* 296 * ARP protocol drain routine. Called when memory is in short supply. 297 * Called at splvm(); 298 */ 299 300 void 301 arp_drain(void) 302 { 303 struct llinfo_arp *la, *nla; 304 int count = 0; 305 struct mbuf *mold; 306 307 if (arp_lock_try(0) == 0) { 308 printf("arp_drain: locked; punting\n"); 309 return; 310 } 311 312 for (la = LIST_FIRST(&llinfo_arp); la != 0; la = nla) { 313 nla = LIST_NEXT(la, la_list); 314 315 mold = la->la_hold; 316 la->la_hold = 0; 317 318 if (mold) { 319 m_freem(mold); 320 count++; 321 } 322 } 323 ARP_UNLOCK(); 324 arpstat.as_dfrdropped += count; 325 } 326 327 328 /* 329 * Timeout routine. Age arp_tab entries periodically. 330 */ 331 /* ARGSUSED */ 332 static void 333 arptimer(void *arg) 334 { 335 int s; 336 struct llinfo_arp *la, *nla; 337 338 s = splsoftnet(); 339 340 if (arp_lock_try(0) == 0) { 341 /* get it later.. */ 342 splx(s); 343 return; 344 } 345 346 callout_reset(&arptimer_ch, arpt_prune * hz, arptimer, NULL); 347 for (la = LIST_FIRST(&llinfo_arp); la != 0; la = nla) { 348 struct rtentry *rt = la->la_rt; 349 350 nla = LIST_NEXT(la, la_list); 351 if (rt->rt_expire == 0) 352 continue; 353 if ((rt->rt_expire - time.tv_sec) < arpt_refresh && 354 rt->rt_pksent > (time.tv_sec - arpt_keep)) { 355 /* 356 * If the entry has been used during since last 357 * refresh, try to renew it before deleting. 358 */ 359 arprequest(rt->rt_ifp, 360 &SIN(rt->rt_ifa->ifa_addr)->sin_addr, 361 &SIN(rt_key(rt))->sin_addr, 362 LLADDR(rt->rt_ifp->if_sadl)); 363 } else if (rt->rt_expire <= time.tv_sec) 364 arptfree(la); /* timer has expired; clear */ 365 } 366 367 ARP_UNLOCK(); 368 369 splx(s); 370 } 371 372 /* 373 * Parallel to llc_rtrequest. 374 */ 375 void 376 arp_rtrequest(int req, struct rtentry *rt, struct rt_addrinfo *info) 377 { 378 struct sockaddr *gate = rt->rt_gateway; 379 struct llinfo_arp *la = (struct llinfo_arp *)rt->rt_llinfo; 380 static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK}; 381 size_t allocsize; 382 struct mbuf *mold; 383 int s; 384 struct in_ifaddr *ia; 385 struct ifaddr *ifa; 386 387 if (!arpinit_done) { 388 arpinit_done = 1; 389 /* 390 * We generate expiration times from time.tv_sec 391 * so avoid accidently creating permanent routes. 392 */ 393 if (time.tv_sec == 0) { 394 time.tv_sec++; 395 } 396 callout_init(&arptimer_ch); 397 callout_reset(&arptimer_ch, hz, arptimer, NULL); 398 } 399 400 if ((rt->rt_flags & RTF_GATEWAY) != 0) { 401 if (req != RTM_ADD) 402 return; 403 404 /* 405 * linklayers with particular link MTU limitation. 406 */ 407 switch(rt->rt_ifp->if_type) { 408 #if NFDDI > 0 409 case IFT_FDDI: 410 if (rt->rt_ifp->if_mtu > FDDIIPMTU) 411 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 412 break; 413 #endif 414 #if NARC > 0 415 case IFT_ARCNET: 416 { 417 int arcipifmtu; 418 419 if (rt->rt_ifp->if_flags & IFF_LINK0) 420 arcipifmtu = arc_ipmtu; 421 else 422 arcipifmtu = ARCMTU; 423 if (rt->rt_ifp->if_mtu > arcipifmtu) 424 rt->rt_rmx.rmx_mtu = arcipifmtu; 425 break; 426 } 427 #endif 428 } 429 return; 430 } 431 432 ARP_LOCK(1); /* we may already be locked here. */ 433 434 switch (req) { 435 436 case RTM_ADD: 437 /* 438 * XXX: If this is a manually added route to interface 439 * such as older version of routed or gated might provide, 440 * restore cloning bit. 441 */ 442 if ((rt->rt_flags & RTF_HOST) == 0 && 443 SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff) 444 rt->rt_flags |= RTF_CLONING; 445 if (rt->rt_flags & RTF_CLONING) { 446 /* 447 * Case 1: This route should come from a route to iface. 448 */ 449 rt_setgate(rt, rt_key(rt), 450 (struct sockaddr *)&null_sdl); 451 gate = rt->rt_gateway; 452 SDL(gate)->sdl_type = rt->rt_ifp->if_type; 453 SDL(gate)->sdl_index = rt->rt_ifp->if_index; 454 /* 455 * Give this route an expiration time, even though 456 * it's a "permanent" route, so that routes cloned 457 * from it do not need their expiration time set. 458 */ 459 rt->rt_expire = time.tv_sec; 460 /* 461 * linklayers with particular link MTU limitation. 462 */ 463 switch (rt->rt_ifp->if_type) { 464 #if NFDDI > 0 465 case IFT_FDDI: 466 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 467 (rt->rt_rmx.rmx_mtu > FDDIIPMTU || 468 (rt->rt_rmx.rmx_mtu == 0 && 469 rt->rt_ifp->if_mtu > FDDIIPMTU))) 470 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 471 break; 472 #endif 473 #if NARC > 0 474 case IFT_ARCNET: 475 { 476 int arcipifmtu; 477 if (rt->rt_ifp->if_flags & IFF_LINK0) 478 arcipifmtu = arc_ipmtu; 479 else 480 arcipifmtu = ARCMTU; 481 482 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 483 (rt->rt_rmx.rmx_mtu > arcipifmtu || 484 (rt->rt_rmx.rmx_mtu == 0 && 485 rt->rt_ifp->if_mtu > arcipifmtu))) 486 rt->rt_rmx.rmx_mtu = arcipifmtu; 487 break; 488 } 489 #endif 490 } 491 break; 492 } 493 /* Announce a new entry if requested. */ 494 if (rt->rt_flags & RTF_ANNOUNCE) 495 arprequest(rt->rt_ifp, 496 &SIN(rt_key(rt))->sin_addr, 497 &SIN(rt_key(rt))->sin_addr, 498 (u_char *)LLADDR(SDL(gate))); 499 /*FALLTHROUGH*/ 500 case RTM_RESOLVE: 501 if (gate->sa_family != AF_LINK || 502 gate->sa_len < sizeof(null_sdl)) { 503 log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n"); 504 break; 505 } 506 SDL(gate)->sdl_type = rt->rt_ifp->if_type; 507 SDL(gate)->sdl_index = rt->rt_ifp->if_index; 508 if (la != 0) 509 break; /* This happens on a route change */ 510 /* 511 * Case 2: This route may come from cloning, or a manual route 512 * add with a LL address. 513 */ 514 switch (SDL(gate)->sdl_type) { 515 #if NTOKEN > 0 516 case IFT_ISO88025: 517 allocsize = sizeof(*la) + sizeof(struct token_rif); 518 break; 519 #endif /* NTOKEN > 0 */ 520 default: 521 allocsize = sizeof(*la); 522 } 523 R_Malloc(la, struct llinfo_arp *, allocsize); 524 rt->rt_llinfo = (caddr_t)la; 525 if (la == 0) { 526 log(LOG_DEBUG, "arp_rtrequest: malloc failed\n"); 527 break; 528 } 529 arp_inuse++, arp_allocated++; 530 Bzero(la, allocsize); 531 la->la_rt = rt; 532 rt->rt_flags |= RTF_LLINFO; 533 LIST_INSERT_HEAD(&llinfo_arp, la, la_list); 534 535 INADDR_TO_IA(SIN(rt_key(rt))->sin_addr, ia); 536 while (ia && ia->ia_ifp != rt->rt_ifp) 537 NEXT_IA_WITH_SAME_ADDR(ia); 538 if (ia) { 539 /* 540 * This test used to be 541 * if (lo0ifp->if_flags & IFF_UP) 542 * It allowed local traffic to be forced through 543 * the hardware by configuring the loopback down. 544 * However, it causes problems during network 545 * configuration for boards that can't receive 546 * packets they send. It is now necessary to clear 547 * "useloopback" and remove the route to force 548 * traffic out to the hardware. 549 * 550 * In 4.4BSD, the above "if" statement checked 551 * rt->rt_ifa against rt_key(rt). It was changed 552 * to the current form so that we can provide a 553 * better support for multiple IPv4 addresses on a 554 * interface. 555 */ 556 rt->rt_expire = 0; 557 Bcopy(LLADDR(rt->rt_ifp->if_sadl), 558 LLADDR(SDL(gate)), 559 SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen); 560 if (useloopback) 561 rt->rt_ifp = lo0ifp; 562 /* 563 * make sure to set rt->rt_ifa to the interface 564 * address we are using, otherwise we will have trouble 565 * with source address selection. 566 */ 567 ifa = &ia->ia_ifa; 568 if (ifa != rt->rt_ifa) { 569 IFAFREE(rt->rt_ifa); 570 IFAREF(ifa); 571 rt->rt_ifa = ifa; 572 } 573 } 574 break; 575 576 case RTM_DELETE: 577 if (la == 0) 578 break; 579 arp_inuse--; 580 LIST_REMOVE(la, la_list); 581 rt->rt_llinfo = 0; 582 rt->rt_flags &= ~RTF_LLINFO; 583 584 s = splnet(); 585 mold = la->la_hold; 586 la->la_hold = 0; 587 splx(s); 588 589 if (mold) 590 m_freem(mold); 591 592 Free((caddr_t)la); 593 } 594 ARP_UNLOCK(); 595 } 596 597 /* 598 * Broadcast an ARP request. Caller specifies: 599 * - arp header source ip address 600 * - arp header target ip address 601 * - arp header source ethernet address 602 */ 603 static void 604 arprequest(struct ifnet *ifp, 605 struct in_addr *sip, struct in_addr *tip, u_int8_t *enaddr) 606 { 607 struct mbuf *m; 608 struct arphdr *ah; 609 struct sockaddr sa; 610 611 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 612 return; 613 MCLAIM(m, &arpdomain.dom_mowner); 614 switch (ifp->if_type) { 615 case IFT_IEEE1394: 616 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 617 ifp->if_addrlen; 618 break; 619 default: 620 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 621 2 * ifp->if_addrlen; 622 break; 623 } 624 m->m_pkthdr.len = m->m_len; 625 MH_ALIGN(m, m->m_len); 626 ah = mtod(m, struct arphdr *); 627 bzero((caddr_t)ah, m->m_len); 628 switch (ifp->if_type) { 629 case IFT_IEEE1394: /* RFC2734 */ 630 /* fill it now for ar_tpa computation */ 631 ah->ar_hrd = htons(ARPHRD_IEEE1394); 632 break; 633 default: 634 /* ifp->if_output will fill ar_hrd */ 635 break; 636 } 637 ah->ar_pro = htons(ETHERTYPE_IP); 638 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 639 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 640 ah->ar_op = htons(ARPOP_REQUEST); 641 bcopy((caddr_t)enaddr, (caddr_t)ar_sha(ah), ah->ar_hln); 642 bcopy((caddr_t)sip, (caddr_t)ar_spa(ah), ah->ar_pln); 643 bcopy((caddr_t)tip, (caddr_t)ar_tpa(ah), ah->ar_pln); 644 sa.sa_family = AF_ARP; 645 sa.sa_len = 2; 646 m->m_flags |= M_BCAST; 647 arpstat.as_sndtotal++; 648 arpstat.as_sndrequest++; 649 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); 650 } 651 652 /* 653 * Resolve an IP address into an ethernet address. If success, 654 * desten is filled in. If there is no entry in arptab, 655 * set one up and broadcast a request for the IP address. 656 * Hold onto this mbuf and resend it once the address 657 * is finally resolved. A return value of 1 indicates 658 * that desten has been filled in and the packet should be sent 659 * normally; a 0 return indicates that the packet has been 660 * taken over here, either now or for later transmission. 661 */ 662 int 663 arpresolve(struct ifnet *ifp, struct rtentry *rt, struct mbuf *m, 664 struct sockaddr *dst, u_char *desten) 665 { 666 struct llinfo_arp *la; 667 struct sockaddr_dl *sdl; 668 struct mbuf *mold; 669 int s; 670 671 if (rt) 672 la = (struct llinfo_arp *)rt->rt_llinfo; 673 else { 674 if ((la = arplookup(m, &SIN(dst)->sin_addr, 1, 0)) != NULL) 675 rt = la->la_rt; 676 } 677 if (la == 0 || rt == 0) { 678 arpstat.as_allocfail++; 679 log(LOG_DEBUG, 680 "arpresolve: can't allocate llinfo on %s for %s\n", 681 ifp->if_xname, in_fmtaddr(SIN(dst)->sin_addr)); 682 m_freem(m); 683 return (0); 684 } 685 sdl = SDL(rt->rt_gateway); 686 /* 687 * Check the address family and length is valid, the address 688 * is resolved; otherwise, try to resolve. 689 */ 690 if ((rt->rt_expire == 0 || rt->rt_expire > time.tv_sec) && 691 sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) { 692 bcopy(LLADDR(sdl), desten, 693 min(sdl->sdl_alen, ifp->if_addrlen)); 694 rt->rt_pksent = time.tv_sec; /* Time for last pkt sent */ 695 return 1; 696 } 697 /* 698 * There is an arptab entry, but no ethernet address 699 * response yet. Replace the held mbuf with this 700 * latest one. 701 */ 702 703 arpstat.as_dfrtotal++; 704 s = splnet(); 705 mold = la->la_hold; 706 la->la_hold = m; 707 splx(s); 708 709 if (mold) { 710 arpstat.as_dfrdropped++; 711 m_freem(mold); 712 } 713 714 /* 715 * Re-send the ARP request when appropriate. 716 */ 717 #ifdef DIAGNOSTIC 718 if (rt->rt_expire == 0) { 719 /* This should never happen. (Should it? -gwr) */ 720 printf("arpresolve: unresolved and rt_expire == 0\n"); 721 /* Set expiration time to now (expired). */ 722 rt->rt_expire = time.tv_sec; 723 } 724 #endif 725 if (rt->rt_expire) { 726 rt->rt_flags &= ~RTF_REJECT; 727 if (la->la_asked == 0 || rt->rt_expire != time.tv_sec) { 728 rt->rt_expire = time.tv_sec; 729 if (la->la_asked++ < arp_maxtries) 730 arprequest(ifp, 731 &SIN(rt->rt_ifa->ifa_addr)->sin_addr, 732 &SIN(dst)->sin_addr, 733 LLADDR(ifp->if_sadl)); 734 else { 735 rt->rt_flags |= RTF_REJECT; 736 rt->rt_expire += arpt_down; 737 la->la_asked = 0; 738 } 739 } 740 } 741 return (0); 742 } 743 744 /* 745 * Common length and type checks are done here, 746 * then the protocol-specific routine is called. 747 */ 748 void 749 arpintr(void) 750 { 751 struct mbuf *m; 752 struct arphdr *ar; 753 int s; 754 int arplen; 755 756 while (arpintrq.ifq_head) { 757 s = splnet(); 758 IF_DEQUEUE(&arpintrq, m); 759 splx(s); 760 if (m == 0 || (m->m_flags & M_PKTHDR) == 0) 761 panic("arpintr"); 762 763 MCLAIM(m, &arpdomain.dom_mowner); 764 arpstat.as_rcvtotal++; 765 766 /* 767 * First, make sure we have at least struct arphdr. 768 */ 769 if (m->m_len < sizeof(struct arphdr) || 770 (ar = mtod(m, struct arphdr *)) == NULL) 771 goto badlen; 772 773 switch (m->m_pkthdr.rcvif->if_type) { 774 case IFT_IEEE1394: 775 arplen = sizeof(struct arphdr) + 776 ar->ar_hln + 2 * ar->ar_pln; 777 break; 778 default: 779 arplen = sizeof(struct arphdr) + 780 2 * ar->ar_hln + 2 * ar->ar_pln; 781 break; 782 } 783 784 if (/* XXX ntohs(ar->ar_hrd) == ARPHRD_ETHER && */ 785 m->m_len >= arplen) 786 switch (ntohs(ar->ar_pro)) { 787 case ETHERTYPE_IP: 788 case ETHERTYPE_IPTRAILERS: 789 in_arpinput(m); 790 continue; 791 default: 792 arpstat.as_rcvbadproto++; 793 } 794 else { 795 badlen: 796 arpstat.as_rcvbadlen++; 797 } 798 m_freem(m); 799 } 800 } 801 802 /* 803 * ARP for Internet protocols on 10 Mb/s Ethernet. 804 * Algorithm is that given in RFC 826. 805 * In addition, a sanity check is performed on the sender 806 * protocol address, to catch impersonators. 807 * We no longer handle negotiations for use of trailer protocol: 808 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent 809 * along with IP replies if we wanted trailers sent to us, 810 * and also sent them in response to IP replies. 811 * This allowed either end to announce the desire to receive 812 * trailer packets. 813 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, 814 * but formerly didn't normally send requests. 815 */ 816 static void 817 in_arpinput(struct mbuf *m) 818 { 819 struct arphdr *ah; 820 struct ifnet *ifp = m->m_pkthdr.rcvif; 821 struct llinfo_arp *la = 0; 822 struct rtentry *rt; 823 struct in_ifaddr *ia; 824 #if NBRIDGE > 0 825 struct in_ifaddr *bridge_ia = NULL; 826 #endif 827 struct sockaddr_dl *sdl; 828 struct sockaddr sa; 829 struct in_addr isaddr, itaddr, myaddr; 830 int op; 831 struct mbuf *mold; 832 int s; 833 834 ah = mtod(m, struct arphdr *); 835 op = ntohs(ah->ar_op); 836 837 /* 838 * Fix up ah->ar_hrd if necessary, before using ar_tha() or 839 * ar_tpa(). 840 */ 841 switch (ifp->if_type) { 842 case IFT_IEEE1394: 843 if (ntohs(ah->ar_hrd) == ARPHRD_IEEE1394) 844 ; 845 else { 846 /* XXX this is to make sure we compute ar_tha right */ 847 /* XXX check ar_hrd more strictly? */ 848 ah->ar_hrd = htons(ARPHRD_IEEE1394); 849 } 850 break; 851 default: 852 /* XXX check ar_hrd? */ 853 break; 854 } 855 856 bcopy((caddr_t)ar_spa(ah), (caddr_t)&isaddr, sizeof (isaddr)); 857 bcopy((caddr_t)ar_tpa(ah), (caddr_t)&itaddr, sizeof (itaddr)); 858 859 if (m->m_flags & (M_BCAST|M_MCAST)) 860 arpstat.as_rcvmcast++; 861 862 /* 863 * If the target IP address is zero, ignore the packet. 864 * This prevents the code below from tring to answer 865 * when we are using IP address zero (booting). 866 */ 867 if (in_nullhost(itaddr)) { 868 arpstat.as_rcvzerotpa++; 869 goto out; 870 } 871 872 /* 873 * If the source IP address is zero, this is most likely a 874 * confused host trying to use IP address zero. (Windoze?) 875 * XXX: Should we bother trying to reply to these? 876 */ 877 if (in_nullhost(isaddr)) { 878 arpstat.as_rcvzerospa++; 879 goto out; 880 } 881 882 /* 883 * Search for a matching interface address 884 * or any address on the interface to use 885 * as a dummy address in the rest of this function 886 */ 887 INADDR_TO_IA(itaddr, ia); 888 while (ia != NULL) { 889 if (ia->ia_ifp == m->m_pkthdr.rcvif) 890 break; 891 892 #if NBRIDGE > 0 893 /* 894 * If the interface we received the packet on 895 * is part of a bridge, check to see if we need 896 * to "bridge" the packet to ourselves at this 897 * layer. Note we still prefer a perfect match, 898 * but allow this weaker match if necessary. 899 */ 900 if (m->m_pkthdr.rcvif->if_bridge != NULL && 901 m->m_pkthdr.rcvif->if_bridge == ia->ia_ifp->if_bridge) 902 bridge_ia = ia; 903 #endif /* NBRIDGE > 0 */ 904 905 NEXT_IA_WITH_SAME_ADDR(ia); 906 } 907 908 #if NBRIDGE > 0 909 if (ia == NULL && bridge_ia != NULL) { 910 ia = bridge_ia; 911 ifp = bridge_ia->ia_ifp; 912 } 913 #endif 914 915 if (ia == NULL) { 916 INADDR_TO_IA(isaddr, ia); 917 while ((ia != NULL) && ia->ia_ifp != m->m_pkthdr.rcvif) 918 NEXT_IA_WITH_SAME_ADDR(ia); 919 920 if (ia == NULL) { 921 IFP_TO_IA(ifp, ia); 922 if (ia == NULL) { 923 arpstat.as_rcvnoint++; 924 goto out; 925 } 926 } 927 } 928 929 myaddr = ia->ia_addr.sin_addr; 930 931 /* XXX checks for bridge case? */ 932 if (!bcmp((caddr_t)ar_sha(ah), LLADDR(ifp->if_sadl), 933 ifp->if_addrlen)) { 934 arpstat.as_rcvlocalsha++; 935 goto out; /* it's from me, ignore it. */ 936 } 937 938 /* XXX checks for bridge case? */ 939 if (!memcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 940 arpstat.as_rcvbcastsha++; 941 log(LOG_ERR, 942 "%s: arp: link address is broadcast for IP address %s!\n", 943 ifp->if_xname, in_fmtaddr(isaddr)); 944 goto out; 945 } 946 947 if (in_hosteq(isaddr, myaddr)) { 948 arpstat.as_rcvlocalspa++; 949 log(LOG_ERR, 950 "duplicate IP address %s sent from link address %s\n", 951 in_fmtaddr(isaddr), lla_snprintf(ar_sha(ah), ah->ar_hln)); 952 itaddr = myaddr; 953 goto reply; 954 } 955 la = arplookup(m, &isaddr, in_hosteq(itaddr, myaddr), 0); 956 if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) { 957 if (sdl->sdl_alen && 958 bcmp((caddr_t)ar_sha(ah), LLADDR(sdl), sdl->sdl_alen)) { 959 if (rt->rt_flags & RTF_STATIC) { 960 arpstat.as_rcvoverperm++; 961 log(LOG_INFO, 962 "%s tried to overwrite permanent arp info" 963 " for %s\n", 964 lla_snprintf(ar_sha(ah), ah->ar_hln), 965 in_fmtaddr(isaddr)); 966 goto out; 967 } else if (rt->rt_ifp != ifp) { 968 arpstat.as_rcvoverint++; 969 log(LOG_INFO, 970 "%s on %s tried to overwrite " 971 "arp info for %s on %s\n", 972 lla_snprintf(ar_sha(ah), ah->ar_hln), 973 ifp->if_xname, in_fmtaddr(isaddr), 974 rt->rt_ifp->if_xname); 975 goto out; 976 } else { 977 arpstat.as_rcvover++; 978 log(LOG_INFO, 979 "arp info overwritten for %s by %s\n", 980 in_fmtaddr(isaddr), 981 lla_snprintf(ar_sha(ah), ah->ar_hln)); 982 } 983 } 984 /* 985 * sanity check for the address length. 986 * XXX this does not work for protocols with variable address 987 * length. -is 988 */ 989 if (sdl->sdl_alen && 990 sdl->sdl_alen != ah->ar_hln) { 991 arpstat.as_rcvlenchg++; 992 log(LOG_WARNING, 993 "arp from %s: new addr len %d, was %d", 994 in_fmtaddr(isaddr), ah->ar_hln, sdl->sdl_alen); 995 } 996 if (ifp->if_addrlen != ah->ar_hln) { 997 arpstat.as_rcvbadlen++; 998 log(LOG_WARNING, 999 "arp from %s: addr len: new %d, i/f %d (ignored)", 1000 in_fmtaddr(isaddr), ah->ar_hln, 1001 ifp->if_addrlen); 1002 goto reply; 1003 } 1004 #if NTOKEN > 0 1005 /* 1006 * XXX uses m_data and assumes the complete answer including 1007 * XXX token-ring headers is in the same buf 1008 */ 1009 if (ifp->if_type == IFT_ISO88025) { 1010 struct token_header *trh; 1011 1012 trh = (struct token_header *)M_TRHSTART(m); 1013 if (trh->token_shost[0] & TOKEN_RI_PRESENT) { 1014 struct token_rif *rif; 1015 size_t riflen; 1016 1017 rif = TOKEN_RIF(trh); 1018 riflen = (ntohs(rif->tr_rcf) & 1019 TOKEN_RCF_LEN_MASK) >> 8; 1020 1021 if (riflen > 2 && 1022 riflen < sizeof(struct token_rif) && 1023 (riflen & 1) == 0) { 1024 rif->tr_rcf ^= htons(TOKEN_RCF_DIRECTION); 1025 rif->tr_rcf &= htons(~TOKEN_RCF_BROADCAST_MASK); 1026 bcopy(rif, TOKEN_RIF(la), riflen); 1027 } 1028 } 1029 } 1030 #endif /* NTOKEN > 0 */ 1031 bcopy((caddr_t)ar_sha(ah), LLADDR(sdl), 1032 sdl->sdl_alen = ah->ar_hln); 1033 if (rt->rt_expire) 1034 rt->rt_expire = time.tv_sec + arpt_keep; 1035 rt->rt_flags &= ~RTF_REJECT; 1036 la->la_asked = 0; 1037 1038 s = splnet(); 1039 mold = la->la_hold; 1040 la->la_hold = 0; 1041 splx(s); 1042 1043 if (mold) { 1044 arpstat.as_dfrsent++; 1045 (*ifp->if_output)(ifp, mold, rt_key(rt), rt); 1046 } 1047 } 1048 reply: 1049 if (op != ARPOP_REQUEST) { 1050 if (op == ARPOP_REPLY) 1051 arpstat.as_rcvreply++; 1052 out: 1053 m_freem(m); 1054 return; 1055 } 1056 arpstat.as_rcvrequest++; 1057 if (in_hosteq(itaddr, myaddr)) { 1058 /* I am the target */ 1059 if (ar_tha(ah)) 1060 bcopy((caddr_t)ar_sha(ah), (caddr_t)ar_tha(ah), 1061 ah->ar_hln); 1062 bcopy(LLADDR(ifp->if_sadl), (caddr_t)ar_sha(ah), ah->ar_hln); 1063 } else { 1064 la = arplookup(m, &itaddr, 0, SIN_PROXY); 1065 if (la == 0) 1066 goto out; 1067 rt = la->la_rt; 1068 if (ar_tha(ah)) 1069 bcopy((caddr_t)ar_sha(ah), (caddr_t)ar_tha(ah), 1070 ah->ar_hln); 1071 sdl = SDL(rt->rt_gateway); 1072 bcopy(LLADDR(sdl), (caddr_t)ar_sha(ah), ah->ar_hln); 1073 } 1074 1075 bcopy((caddr_t)ar_spa(ah), (caddr_t)ar_tpa(ah), ah->ar_pln); 1076 bcopy((caddr_t)&itaddr, (caddr_t)ar_spa(ah), ah->ar_pln); 1077 ah->ar_op = htons(ARPOP_REPLY); 1078 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 1079 switch (ifp->if_type) { 1080 case IFT_IEEE1394: 1081 /* 1082 * ieee1394 arp reply is broadcast 1083 */ 1084 m->m_flags &= ~M_MCAST; 1085 m->m_flags |= M_BCAST; 1086 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + ah->ar_hln; 1087 break; 1088 1089 default: 1090 m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */ 1091 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); 1092 break; 1093 } 1094 m->m_pkthdr.len = m->m_len; 1095 sa.sa_family = AF_ARP; 1096 sa.sa_len = 2; 1097 arpstat.as_sndtotal++; 1098 arpstat.as_sndreply++; 1099 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); 1100 return; 1101 } 1102 1103 /* 1104 * Free an arp entry. 1105 */ 1106 static void arptfree(struct llinfo_arp *la) 1107 { 1108 struct rtentry *rt = la->la_rt; 1109 struct sockaddr_dl *sdl; 1110 1111 ARP_LOCK_CHECK(); 1112 1113 if (rt == 0) 1114 panic("arptfree"); 1115 if (rt->rt_refcnt > 0 && (sdl = SDL(rt->rt_gateway)) && 1116 sdl->sdl_family == AF_LINK) { 1117 sdl->sdl_alen = 0; 1118 la->la_asked = 0; 1119 rt->rt_flags &= ~RTF_REJECT; 1120 return; 1121 } 1122 rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0, rt_mask(rt), 1123 0, (struct rtentry **)0); 1124 } 1125 1126 /* 1127 * Lookup or enter a new address in arptab. 1128 */ 1129 static struct llinfo_arp * 1130 arplookup(struct mbuf *m, struct in_addr *addr, int create, int proxy) 1131 { 1132 struct arphdr *ah; 1133 struct ifnet *ifp = m->m_pkthdr.rcvif; 1134 struct rtentry *rt; 1135 static struct sockaddr_inarp sin; 1136 const char *why = 0; 1137 1138 ah = mtod(m, struct arphdr *); 1139 sin.sin_len = sizeof(sin); 1140 sin.sin_family = AF_INET; 1141 sin.sin_addr = *addr; 1142 sin.sin_other = proxy ? SIN_PROXY : 0; 1143 rt = rtalloc1(sintosa(&sin), create); 1144 if (rt == 0) 1145 return (0); 1146 rt->rt_refcnt--; 1147 1148 if ((rt->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) == RTF_LLINFO && 1149 rt->rt_gateway->sa_family == AF_LINK) 1150 return ((struct llinfo_arp *)rt->rt_llinfo); 1151 1152 1153 1154 if (create) { 1155 if (rt->rt_flags & RTF_GATEWAY) 1156 why = "host is not on local network"; 1157 else if ((rt->rt_flags & RTF_LLINFO) == 0) { 1158 arpstat.as_allocfail++; 1159 why = "could not allocate llinfo"; 1160 } else 1161 why = "gateway route is not ours"; 1162 log(LOG_DEBUG, "arplookup: unable to enter address" 1163 " for %s@%s on %s (%s)\n", 1164 in_fmtaddr(*addr), lla_snprintf(ar_sha(ah), ah->ar_hln), 1165 (ifp) ? ifp->if_xname : 0, why); 1166 if (rt->rt_refcnt <= 0 && (rt->rt_flags & RTF_CLONED) != 0) { 1167 rtrequest(RTM_DELETE, (struct sockaddr *)rt_key(rt), 1168 rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0); 1169 } 1170 } 1171 return (0); 1172 } 1173 1174 int 1175 arpioctl(u_long cmd, caddr_t data) 1176 { 1177 1178 return (EOPNOTSUPP); 1179 } 1180 1181 void 1182 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1183 { 1184 struct in_addr *ip; 1185 1186 /* 1187 * Warn the user if another station has this IP address, 1188 * but only if the interface IP address is not zero. 1189 */ 1190 ip = &IA_SIN(ifa)->sin_addr; 1191 if (!in_nullhost(*ip)) 1192 arprequest(ifp, ip, ip, LLADDR(ifp->if_sadl)); 1193 1194 ifa->ifa_rtrequest = arp_rtrequest; 1195 ifa->ifa_flags |= RTF_CLONING; 1196 } 1197 1198 /* 1199 * Called from 10 Mb/s Ethernet interrupt handlers 1200 * when ether packet type ETHERTYPE_REVARP 1201 * is received. Common length and type checks are done here, 1202 * then the protocol-specific routine is called. 1203 */ 1204 void 1205 revarpinput(struct mbuf *m) 1206 { 1207 struct arphdr *ar; 1208 1209 if (m->m_len < sizeof(struct arphdr)) 1210 goto out; 1211 ar = mtod(m, struct arphdr *); 1212 #if 0 /* XXX I don't think we need this... and it will prevent other LL */ 1213 if (ntohs(ar->ar_hrd) != ARPHRD_ETHER) 1214 goto out; 1215 #endif 1216 if (m->m_len < sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln)) 1217 goto out; 1218 switch (ntohs(ar->ar_pro)) { 1219 case ETHERTYPE_IP: 1220 case ETHERTYPE_IPTRAILERS: 1221 in_revarpinput(m); 1222 return; 1223 1224 default: 1225 break; 1226 } 1227 out: 1228 m_freem(m); 1229 } 1230 1231 /* 1232 * RARP for Internet protocols on 10 Mb/s Ethernet. 1233 * Algorithm is that given in RFC 903. 1234 * We are only using for bootstrap purposes to get an ip address for one of 1235 * our interfaces. Thus we support no user-interface. 1236 * 1237 * Since the contents of the RARP reply are specific to the interface that 1238 * sent the request, this code must ensure that they are properly associated. 1239 * 1240 * Note: also supports ARP via RARP packets, per the RFC. 1241 */ 1242 void 1243 in_revarpinput(struct mbuf *m) 1244 { 1245 struct ifnet *ifp; 1246 struct arphdr *ah; 1247 int op; 1248 1249 ah = mtod(m, struct arphdr *); 1250 op = ntohs(ah->ar_op); 1251 1252 switch (m->m_pkthdr.rcvif->if_type) { 1253 case IFT_IEEE1394: 1254 /* ARP without target hardware address is not supported */ 1255 goto out; 1256 default: 1257 break; 1258 } 1259 1260 switch (op) { 1261 case ARPOP_REQUEST: 1262 case ARPOP_REPLY: /* per RFC */ 1263 in_arpinput(m); 1264 return; 1265 case ARPOP_REVREPLY: 1266 break; 1267 case ARPOP_REVREQUEST: /* handled by rarpd(8) */ 1268 default: 1269 goto out; 1270 } 1271 if (!revarp_in_progress) 1272 goto out; 1273 ifp = m->m_pkthdr.rcvif; 1274 if (ifp != myip_ifp) /* !same interface */ 1275 goto out; 1276 if (myip_initialized) 1277 goto wake; 1278 if (bcmp(ar_tha(ah), LLADDR(ifp->if_sadl), ifp->if_sadl->sdl_alen)) 1279 goto out; 1280 bcopy((caddr_t)ar_spa(ah), (caddr_t)&srv_ip, sizeof(srv_ip)); 1281 bcopy((caddr_t)ar_tpa(ah), (caddr_t)&myip, sizeof(myip)); 1282 myip_initialized = 1; 1283 wake: /* Do wakeup every time in case it was missed. */ 1284 wakeup((caddr_t)&myip); 1285 1286 out: 1287 m_freem(m); 1288 } 1289 1290 /* 1291 * Send a RARP request for the ip address of the specified interface. 1292 * The request should be RFC 903-compliant. 1293 */ 1294 void 1295 revarprequest(struct ifnet *ifp) 1296 { 1297 struct sockaddr sa; 1298 struct mbuf *m; 1299 struct arphdr *ah; 1300 1301 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 1302 return; 1303 MCLAIM(m, &arpdomain.dom_mowner); 1304 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) + 1305 2*ifp->if_addrlen; 1306 m->m_pkthdr.len = m->m_len; 1307 MH_ALIGN(m, m->m_len); 1308 ah = mtod(m, struct arphdr *); 1309 bzero((caddr_t)ah, m->m_len); 1310 ah->ar_pro = htons(ETHERTYPE_IP); 1311 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 1312 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 1313 ah->ar_op = htons(ARPOP_REVREQUEST); 1314 1315 bcopy(LLADDR(ifp->if_sadl), (caddr_t)ar_sha(ah), ah->ar_hln); 1316 bcopy(LLADDR(ifp->if_sadl), (caddr_t)ar_tha(ah), ah->ar_hln); 1317 1318 sa.sa_family = AF_ARP; 1319 sa.sa_len = 2; 1320 m->m_flags |= M_BCAST; 1321 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); 1322 1323 } 1324 1325 /* 1326 * RARP for the ip address of the specified interface, but also 1327 * save the ip address of the server that sent the answer. 1328 * Timeout if no response is received. 1329 */ 1330 int 1331 revarpwhoarewe(struct ifnet *ifp, struct in_addr *serv_in, 1332 struct in_addr *clnt_in) 1333 { 1334 int result, count = 20; 1335 1336 myip_initialized = 0; 1337 myip_ifp = ifp; 1338 1339 revarp_in_progress = 1; 1340 while (count--) { 1341 revarprequest(ifp); 1342 result = tsleep((caddr_t)&myip, PSOCK, "revarp", hz/2); 1343 if (result != EWOULDBLOCK) 1344 break; 1345 } 1346 revarp_in_progress = 0; 1347 1348 if (!myip_initialized) 1349 return ENETUNREACH; 1350 1351 bcopy((caddr_t)&srv_ip, serv_in, sizeof(*serv_in)); 1352 bcopy((caddr_t)&myip, clnt_in, sizeof(*clnt_in)); 1353 return 0; 1354 } 1355 1356 1357 1358 #ifdef DDB 1359 1360 #include <machine/db_machdep.h> 1361 #include <ddb/db_interface.h> 1362 #include <ddb/db_output.h> 1363 1364 static void 1365 db_print_sa(const struct sockaddr *sa) 1366 { 1367 int len; 1368 const u_char *p; 1369 1370 if (sa == 0) { 1371 db_printf("[NULL]"); 1372 return; 1373 } 1374 1375 p = (const u_char *)sa; 1376 len = sa->sa_len; 1377 db_printf("["); 1378 while (len > 0) { 1379 db_printf("%d", *p); 1380 p++; len--; 1381 if (len) db_printf(","); 1382 } 1383 db_printf("]\n"); 1384 } 1385 1386 static void 1387 db_print_ifa(struct ifaddr *ifa) 1388 { 1389 if (ifa == 0) 1390 return; 1391 db_printf(" ifa_addr="); 1392 db_print_sa(ifa->ifa_addr); 1393 db_printf(" ifa_dsta="); 1394 db_print_sa(ifa->ifa_dstaddr); 1395 db_printf(" ifa_mask="); 1396 db_print_sa(ifa->ifa_netmask); 1397 db_printf(" flags=0x%x,refcnt=%d,metric=%d\n", 1398 ifa->ifa_flags, 1399 ifa->ifa_refcnt, 1400 ifa->ifa_metric); 1401 } 1402 1403 static void 1404 db_print_llinfo(caddr_t li) 1405 { 1406 struct llinfo_arp *la; 1407 1408 if (li == 0) 1409 return; 1410 la = (struct llinfo_arp *)li; 1411 db_printf(" la_rt=%p la_hold=%p, la_asked=0x%lx\n", 1412 la->la_rt, la->la_hold, la->la_asked); 1413 } 1414 1415 /* 1416 * Function to pass to rn_walktree(). 1417 * Return non-zero error to abort walk. 1418 */ 1419 static int 1420 db_show_radix_node(struct radix_node *rn, void *w) 1421 { 1422 struct rtentry *rt = (struct rtentry *)rn; 1423 1424 db_printf("rtentry=%p", rt); 1425 1426 db_printf(" flags=0x%x refcnt=%d use=%ld expire=%ld\n", 1427 rt->rt_flags, rt->rt_refcnt, 1428 rt->rt_use, rt->rt_expire); 1429 1430 db_printf(" key="); db_print_sa(rt_key(rt)); 1431 db_printf(" mask="); db_print_sa(rt_mask(rt)); 1432 db_printf(" gw="); db_print_sa(rt->rt_gateway); 1433 1434 db_printf(" ifp=%p ", rt->rt_ifp); 1435 if (rt->rt_ifp) 1436 db_printf("(%s)", rt->rt_ifp->if_xname); 1437 else 1438 db_printf("(NULL)"); 1439 1440 db_printf(" ifa=%p\n", rt->rt_ifa); 1441 db_print_ifa(rt->rt_ifa); 1442 1443 db_printf(" genmask="); db_print_sa(rt->rt_genmask); 1444 1445 db_printf(" gwroute=%p llinfo=%p\n", 1446 rt->rt_gwroute, rt->rt_llinfo); 1447 db_print_llinfo(rt->rt_llinfo); 1448 1449 return (0); 1450 } 1451 1452 /* 1453 * Function to print all the route trees. 1454 * Use this from ddb: "show arptab" 1455 */ 1456 void 1457 db_show_arptab(db_expr_t addr, int have_addr, db_expr_t count, const char *modif) 1458 { 1459 struct radix_node_head *rnh; 1460 rnh = rt_tables[AF_INET]; 1461 db_printf("Route tree for AF_INET\n"); 1462 if (rnh == NULL) { 1463 db_printf(" (not initialized)\n"); 1464 return; 1465 } 1466 rn_walktree(rnh, db_show_radix_node, NULL); 1467 return; 1468 } 1469 #endif 1470 1471 SYSCTL_SETUP(sysctl_net_inet_arp_setup, "sysctl net.inet.arp subtree setup") 1472 { 1473 const struct sysctlnode *node; 1474 1475 sysctl_createv(clog, 0, NULL, NULL, 1476 CTLFLAG_PERMANENT, 1477 CTLTYPE_NODE, "net", NULL, 1478 NULL, 0, NULL, 0, 1479 CTL_NET, CTL_EOL); 1480 sysctl_createv(clog, 0, NULL, NULL, 1481 CTLFLAG_PERMANENT, 1482 CTLTYPE_NODE, "inet", NULL, 1483 NULL, 0, NULL, 0, 1484 CTL_NET, PF_INET, CTL_EOL); 1485 sysctl_createv(clog, 0, NULL, &node, 1486 CTLFLAG_PERMANENT, 1487 CTLTYPE_NODE, "arp", 1488 SYSCTL_DESCR("Address Resolution Protocol"), 1489 NULL, 0, NULL, 0, 1490 CTL_NET, PF_INET, CTL_CREATE, CTL_EOL); 1491 1492 sysctl_createv(clog, 0, NULL, NULL, 1493 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1494 CTLTYPE_INT, "prune", 1495 SYSCTL_DESCR("ARP cache pruning interval"), 1496 NULL, 0, &arpt_prune, 0, 1497 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1498 1499 sysctl_createv(clog, 0, NULL, NULL, 1500 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1501 CTLTYPE_INT, "keep", 1502 SYSCTL_DESCR("Valid ARP entry lifetime"), 1503 NULL, 0, &arpt_keep, 0, 1504 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1505 1506 sysctl_createv(clog, 0, NULL, NULL, 1507 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1508 CTLTYPE_INT, "down", 1509 SYSCTL_DESCR("Failed ARP entry lifetime"), 1510 NULL, 0, &arpt_down, 0, 1511 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1512 1513 sysctl_createv(clog, 0, NULL, NULL, 1514 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1515 CTLTYPE_INT, "refresh", 1516 SYSCTL_DESCR("ARP entry refresh interval"), 1517 NULL, 0, &arpt_refresh, 0, 1518 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1519 } 1520 1521 #endif /* INET */ 1522