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sys/netinet/if_arp.c
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1 /* $NetBSD: if_arp.c,v 1.117.2.1 2008/08/29 20:59:29 bouyer 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 1.117.2.1 2008/08/29 20:59:29 bouyer 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) 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) 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 accidentally 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 rt_replace_ifa(rt, ifa); 592 } 593 break; 594 595 case RTM_DELETE: 596 if (la == 0) 597 break; 598 arp_inuse--; 599 LIST_REMOVE(la, la_list); 600 rt->rt_llinfo = 0; 601 rt->rt_flags &= ~RTF_LLINFO; 602 603 s = splnet(); 604 mold = la->la_hold; 605 la->la_hold = 0; 606 splx(s); 607 608 if (mold) 609 m_freem(mold); 610 611 Free((caddr_t)la); 612 } 613 ARP_UNLOCK(); 614 } 615 616 /* 617 * Broadcast an ARP request. Caller specifies: 618 * - arp header source ip address 619 * - arp header target ip address 620 * - arp header source ethernet address 621 */ 622 void 623 arprequest(struct ifnet *ifp, 624 struct in_addr *sip, struct in_addr *tip, u_int8_t *enaddr) 625 { 626 struct mbuf *m; 627 struct arphdr *ah; 628 struct sockaddr sa; 629 630 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 631 return; 632 MCLAIM(m, &arpdomain.dom_mowner); 633 switch (ifp->if_type) { 634 case IFT_IEEE1394: 635 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 636 ifp->if_addrlen; 637 break; 638 default: 639 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 640 2 * ifp->if_addrlen; 641 break; 642 } 643 m->m_pkthdr.len = m->m_len; 644 MH_ALIGN(m, m->m_len); 645 ah = mtod(m, struct arphdr *); 646 bzero((caddr_t)ah, m->m_len); 647 switch (ifp->if_type) { 648 case IFT_IEEE1394: /* RFC2734 */ 649 /* fill it now for ar_tpa computation */ 650 ah->ar_hrd = htons(ARPHRD_IEEE1394); 651 break; 652 default: 653 /* ifp->if_output will fill ar_hrd */ 654 break; 655 } 656 ah->ar_pro = htons(ETHERTYPE_IP); 657 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 658 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 659 ah->ar_op = htons(ARPOP_REQUEST); 660 bcopy((caddr_t)enaddr, (caddr_t)ar_sha(ah), ah->ar_hln); 661 bcopy((caddr_t)sip, (caddr_t)ar_spa(ah), ah->ar_pln); 662 bcopy((caddr_t)tip, (caddr_t)ar_tpa(ah), ah->ar_pln); 663 sa.sa_family = AF_ARP; 664 sa.sa_len = 2; 665 m->m_flags |= M_BCAST; 666 arpstat.as_sndtotal++; 667 arpstat.as_sndrequest++; 668 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); 669 } 670 671 /* 672 * Resolve an IP address into an ethernet address. If success, 673 * desten is filled in. If there is no entry in arptab, 674 * set one up and broadcast a request for the IP address. 675 * Hold onto this mbuf and resend it once the address 676 * is finally resolved. A return value of 1 indicates 677 * that desten has been filled in and the packet should be sent 678 * normally; a 0 return indicates that the packet has been 679 * taken over here, either now or for later transmission. 680 */ 681 int 682 arpresolve(struct ifnet *ifp, struct rtentry *rt, struct mbuf *m, 683 struct sockaddr *dst, u_char *desten) 684 { 685 struct llinfo_arp *la; 686 struct sockaddr_dl *sdl; 687 struct mbuf *mold; 688 int s; 689 690 if (rt) 691 la = (struct llinfo_arp *)rt->rt_llinfo; 692 else { 693 if ((la = arplookup(m, &SIN(dst)->sin_addr, 1, 0)) != NULL) 694 rt = la->la_rt; 695 } 696 if (la == 0 || rt == 0) { 697 arpstat.as_allocfail++; 698 log(LOG_DEBUG, 699 "arpresolve: can't allocate llinfo on %s for %s\n", 700 ifp->if_xname, in_fmtaddr(SIN(dst)->sin_addr)); 701 m_freem(m); 702 return (0); 703 } 704 sdl = SDL(rt->rt_gateway); 705 /* 706 * Check the address family and length is valid, the address 707 * is resolved; otherwise, try to resolve. 708 */ 709 if ((rt->rt_expire == 0 || rt->rt_expire > time_second) && 710 sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) { 711 bcopy(LLADDR(sdl), desten, 712 min(sdl->sdl_alen, ifp->if_addrlen)); 713 rt->rt_pksent = time_second; /* Time for last pkt sent */ 714 return 1; 715 } 716 /* 717 * There is an arptab entry, but no ethernet address 718 * response yet. Replace the held mbuf with this 719 * latest one. 720 */ 721 722 arpstat.as_dfrtotal++; 723 s = splnet(); 724 mold = la->la_hold; 725 la->la_hold = m; 726 splx(s); 727 728 if (mold) { 729 arpstat.as_dfrdropped++; 730 m_freem(mold); 731 } 732 733 /* 734 * Re-send the ARP request when appropriate. 735 */ 736 #ifdef DIAGNOSTIC 737 if (rt->rt_expire == 0) { 738 /* This should never happen. (Should it? -gwr) */ 739 printf("arpresolve: unresolved and rt_expire == 0\n"); 740 /* Set expiration time to now (expired). */ 741 rt->rt_expire = time_second; 742 } 743 #endif 744 if (rt->rt_expire) { 745 rt->rt_flags &= ~RTF_REJECT; 746 if (la->la_asked == 0 || rt->rt_expire != time_second) { 747 rt->rt_expire = time_second; 748 if (la->la_asked++ < arp_maxtries) 749 arprequest(ifp, 750 &SIN(rt->rt_ifa->ifa_addr)->sin_addr, 751 &SIN(dst)->sin_addr, 752 #if NCARP > 0 753 (rt->rt_ifp->if_type == IFT_CARP) ? 754 LLADDR(rt->rt_ifp->if_sadl): 755 #endif 756 LLADDR(ifp->if_sadl)); 757 else { 758 rt->rt_flags |= RTF_REJECT; 759 rt->rt_expire += arpt_down; 760 la->la_asked = 0; 761 } 762 } 763 } 764 return (0); 765 } 766 767 /* 768 * Common length and type checks are done here, 769 * then the protocol-specific routine is called. 770 */ 771 void 772 arpintr(void) 773 { 774 struct mbuf *m; 775 struct arphdr *ar; 776 int s; 777 int arplen; 778 779 while (arpintrq.ifq_head) { 780 s = splnet(); 781 IF_DEQUEUE(&arpintrq, m); 782 splx(s); 783 if (m == 0 || (m->m_flags & M_PKTHDR) == 0) 784 panic("arpintr"); 785 786 MCLAIM(m, &arpdomain.dom_mowner); 787 arpstat.as_rcvtotal++; 788 789 /* 790 * First, make sure we have at least struct arphdr. 791 */ 792 if (m->m_len < sizeof(struct arphdr) || 793 (ar = mtod(m, struct arphdr *)) == NULL) 794 goto badlen; 795 796 switch (m->m_pkthdr.rcvif->if_type) { 797 case IFT_IEEE1394: 798 arplen = sizeof(struct arphdr) + 799 ar->ar_hln + 2 * ar->ar_pln; 800 break; 801 default: 802 arplen = sizeof(struct arphdr) + 803 2 * ar->ar_hln + 2 * ar->ar_pln; 804 break; 805 } 806 807 if (/* XXX ntohs(ar->ar_hrd) == ARPHRD_ETHER && */ 808 m->m_len >= arplen) 809 switch (ntohs(ar->ar_pro)) { 810 case ETHERTYPE_IP: 811 case ETHERTYPE_IPTRAILERS: 812 in_arpinput(m); 813 continue; 814 default: 815 arpstat.as_rcvbadproto++; 816 } 817 else { 818 badlen: 819 arpstat.as_rcvbadlen++; 820 } 821 m_freem(m); 822 } 823 } 824 825 /* 826 * ARP for Internet protocols on 10 Mb/s Ethernet. 827 * Algorithm is that given in RFC 826. 828 * In addition, a sanity check is performed on the sender 829 * protocol address, to catch impersonators. 830 * We no longer handle negotiations for use of trailer protocol: 831 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent 832 * along with IP replies if we wanted trailers sent to us, 833 * and also sent them in response to IP replies. 834 * This allowed either end to announce the desire to receive 835 * trailer packets. 836 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, 837 * but formerly didn't normally send requests. 838 */ 839 static void 840 in_arpinput(struct mbuf *m) 841 { 842 struct arphdr *ah; 843 struct ifnet *ifp = m->m_pkthdr.rcvif; 844 struct llinfo_arp *la = 0; 845 struct rtentry *rt; 846 struct in_ifaddr *ia; 847 #if NBRIDGE > 0 848 struct in_ifaddr *bridge_ia = NULL; 849 #endif 850 #if NCARP > 0 851 u_int32_t count = 0, index = 0; 852 #endif 853 struct sockaddr_dl *sdl; 854 struct sockaddr sa; 855 struct in_addr isaddr, itaddr, myaddr; 856 int op; 857 struct mbuf *mold; 858 caddr_t tha; 859 int s; 860 861 if (__predict_false(m_makewritable(&m, 0, m->m_pkthdr.len, M_DONTWAIT))) 862 goto out; 863 ah = mtod(m, struct arphdr *); 864 op = ntohs(ah->ar_op); 865 866 /* 867 * Fix up ah->ar_hrd if necessary, before using ar_tha() or 868 * ar_tpa(). 869 */ 870 switch (ifp->if_type) { 871 case IFT_IEEE1394: 872 if (ntohs(ah->ar_hrd) == ARPHRD_IEEE1394) 873 ; 874 else { 875 /* XXX this is to make sure we compute ar_tha right */ 876 /* XXX check ar_hrd more strictly? */ 877 ah->ar_hrd = htons(ARPHRD_IEEE1394); 878 } 879 break; 880 default: 881 /* XXX check ar_hrd? */ 882 break; 883 } 884 885 bcopy((caddr_t)ar_spa(ah), (caddr_t)&isaddr, sizeof (isaddr)); 886 bcopy((caddr_t)ar_tpa(ah), (caddr_t)&itaddr, sizeof (itaddr)); 887 888 if (m->m_flags & (M_BCAST|M_MCAST)) 889 arpstat.as_rcvmcast++; 890 891 /* 892 * If the target IP address is zero, ignore the packet. 893 * This prevents the code below from tring to answer 894 * when we are using IP address zero (booting). 895 */ 896 if (in_nullhost(itaddr)) { 897 arpstat.as_rcvzerotpa++; 898 goto out; 899 } 900 901 /* 902 * If the source IP address is zero, this is most likely a 903 * confused host trying to use IP address zero. (Windoze?) 904 * XXX: Should we bother trying to reply to these? 905 */ 906 if (in_nullhost(isaddr)) { 907 arpstat.as_rcvzerospa++; 908 goto out; 909 } 910 911 /* 912 * Search for a matching interface address 913 * or any address on the interface to use 914 * as a dummy address in the rest of this function 915 */ 916 917 INADDR_TO_IA(itaddr, ia); 918 while (ia != NULL) { 919 #if NCARP > 0 920 if (ia->ia_ifp->if_type == IFT_CARP && 921 ((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) == 922 (IFF_UP|IFF_RUNNING))) { 923 index++; 924 if (ia->ia_ifp == m->m_pkthdr.rcvif && 925 carp_iamatch(ia, ar_sha(ah), 926 &count, index)) { 927 break; 928 } 929 } else 930 #endif 931 if (ia->ia_ifp == m->m_pkthdr.rcvif) 932 break; 933 #if NBRIDGE > 0 934 /* 935 * If the interface we received the packet on 936 * is part of a bridge, check to see if we need 937 * to "bridge" the packet to ourselves at this 938 * layer. Note we still prefer a perfect match, 939 * but allow this weaker match if necessary. 940 */ 941 if (m->m_pkthdr.rcvif->if_bridge != NULL && 942 m->m_pkthdr.rcvif->if_bridge == ia->ia_ifp->if_bridge) 943 bridge_ia = ia; 944 #endif /* NBRIDGE > 0 */ 945 946 NEXT_IA_WITH_SAME_ADDR(ia); 947 } 948 949 #if NBRIDGE > 0 950 if (ia == NULL && bridge_ia != NULL) { 951 ia = bridge_ia; 952 ifp = bridge_ia->ia_ifp; 953 } 954 #endif 955 956 if (ia == NULL) { 957 INADDR_TO_IA(isaddr, ia); 958 while ((ia != NULL) && ia->ia_ifp != m->m_pkthdr.rcvif) 959 NEXT_IA_WITH_SAME_ADDR(ia); 960 961 if (ia == NULL) { 962 IFP_TO_IA(ifp, ia); 963 if (ia == NULL) { 964 arpstat.as_rcvnoint++; 965 goto out; 966 } 967 } 968 } 969 970 myaddr = ia->ia_addr.sin_addr; 971 972 /* XXX checks for bridge case? */ 973 if (!bcmp((caddr_t)ar_sha(ah), LLADDR(ifp->if_sadl), 974 ifp->if_addrlen)) { 975 arpstat.as_rcvlocalsha++; 976 goto out; /* it's from me, ignore it. */ 977 } 978 979 /* XXX checks for bridge case? */ 980 if (!memcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 981 arpstat.as_rcvbcastsha++; 982 log(LOG_ERR, 983 "%s: arp: link address is broadcast for IP address %s!\n", 984 ifp->if_xname, in_fmtaddr(isaddr)); 985 goto out; 986 } 987 988 if (in_hosteq(isaddr, myaddr)) { 989 arpstat.as_rcvlocalspa++; 990 log(LOG_ERR, 991 "duplicate IP address %s sent from link address %s\n", 992 in_fmtaddr(isaddr), lla_snprintf(ar_sha(ah), ah->ar_hln)); 993 itaddr = myaddr; 994 goto reply; 995 } 996 la = arplookup(m, &isaddr, in_hosteq(itaddr, myaddr), 0); 997 if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) { 998 if (sdl->sdl_alen && 999 bcmp((caddr_t)ar_sha(ah), LLADDR(sdl), sdl->sdl_alen)) { 1000 if (rt->rt_flags & RTF_STATIC) { 1001 arpstat.as_rcvoverperm++; 1002 log(LOG_INFO, 1003 "%s tried to overwrite permanent arp info" 1004 " for %s\n", 1005 lla_snprintf(ar_sha(ah), ah->ar_hln), 1006 in_fmtaddr(isaddr)); 1007 goto out; 1008 } else if (rt->rt_ifp != ifp) { 1009 arpstat.as_rcvoverint++; 1010 log(LOG_INFO, 1011 "%s on %s tried to overwrite " 1012 "arp info for %s on %s\n", 1013 lla_snprintf(ar_sha(ah), ah->ar_hln), 1014 ifp->if_xname, in_fmtaddr(isaddr), 1015 rt->rt_ifp->if_xname); 1016 goto out; 1017 } else { 1018 arpstat.as_rcvover++; 1019 log(LOG_INFO, 1020 "arp info overwritten for %s by %s\n", 1021 in_fmtaddr(isaddr), 1022 lla_snprintf(ar_sha(ah), ah->ar_hln)); 1023 } 1024 } 1025 /* 1026 * sanity check for the address length. 1027 * XXX this does not work for protocols with variable address 1028 * length. -is 1029 */ 1030 if (sdl->sdl_alen && 1031 sdl->sdl_alen != ah->ar_hln) { 1032 arpstat.as_rcvlenchg++; 1033 log(LOG_WARNING, 1034 "arp from %s: new addr len %d, was %d\n", 1035 in_fmtaddr(isaddr), ah->ar_hln, sdl->sdl_alen); 1036 } 1037 if (ifp->if_addrlen != ah->ar_hln) { 1038 arpstat.as_rcvbadlen++; 1039 log(LOG_WARNING, 1040 "arp from %s: addr len: new %d, i/f %d (ignored)\n", 1041 in_fmtaddr(isaddr), ah->ar_hln, 1042 ifp->if_addrlen); 1043 goto reply; 1044 } 1045 #if NTOKEN > 0 1046 /* 1047 * XXX uses m_data and assumes the complete answer including 1048 * XXX token-ring headers is in the same buf 1049 */ 1050 if (ifp->if_type == IFT_ISO88025) { 1051 struct token_header *trh; 1052 1053 trh = (struct token_header *)M_TRHSTART(m); 1054 if (trh->token_shost[0] & TOKEN_RI_PRESENT) { 1055 struct token_rif *rif; 1056 size_t riflen; 1057 1058 rif = TOKEN_RIF(trh); 1059 riflen = (ntohs(rif->tr_rcf) & 1060 TOKEN_RCF_LEN_MASK) >> 8; 1061 1062 if (riflen > 2 && 1063 riflen < sizeof(struct token_rif) && 1064 (riflen & 1) == 0) { 1065 rif->tr_rcf ^= htons(TOKEN_RCF_DIRECTION); 1066 rif->tr_rcf &= htons(~TOKEN_RCF_BROADCAST_MASK); 1067 bcopy(rif, TOKEN_RIF(la), riflen); 1068 } 1069 } 1070 } 1071 #endif /* NTOKEN > 0 */ 1072 bcopy((caddr_t)ar_sha(ah), LLADDR(sdl), 1073 sdl->sdl_alen = ah->ar_hln); 1074 if (rt->rt_expire) 1075 rt->rt_expire = time_second + arpt_keep; 1076 rt->rt_flags &= ~RTF_REJECT; 1077 la->la_asked = 0; 1078 1079 s = splnet(); 1080 mold = la->la_hold; 1081 la->la_hold = 0; 1082 splx(s); 1083 1084 if (mold) { 1085 arpstat.as_dfrsent++; 1086 (*ifp->if_output)(ifp, mold, rt_key(rt), rt); 1087 } 1088 } 1089 reply: 1090 if (op != ARPOP_REQUEST) { 1091 if (op == ARPOP_REPLY) 1092 arpstat.as_rcvreply++; 1093 out: 1094 m_freem(m); 1095 return; 1096 } 1097 arpstat.as_rcvrequest++; 1098 if (in_hosteq(itaddr, myaddr)) { 1099 /* I am the target */ 1100 tha = ar_tha(ah); 1101 if (tha) 1102 bcopy((caddr_t)ar_sha(ah), tha, ah->ar_hln); 1103 bcopy(LLADDR(ifp->if_sadl), (caddr_t)ar_sha(ah), ah->ar_hln); 1104 } else { 1105 la = arplookup(m, &itaddr, 0, SIN_PROXY); 1106 if (la == 0) 1107 goto out; 1108 rt = la->la_rt; 1109 if (rt->rt_ifp->if_type == IFT_CARP && 1110 m->m_pkthdr.rcvif->if_type != IFT_CARP) 1111 goto out; 1112 tha = ar_tha(ah); 1113 if (tha) 1114 bcopy((caddr_t)ar_sha(ah), tha, ah->ar_hln); 1115 sdl = SDL(rt->rt_gateway); 1116 bcopy(LLADDR(sdl), (caddr_t)ar_sha(ah), ah->ar_hln); 1117 } 1118 1119 bcopy((caddr_t)ar_spa(ah), (caddr_t)ar_tpa(ah), ah->ar_pln); 1120 bcopy((caddr_t)&itaddr, (caddr_t)ar_spa(ah), ah->ar_pln); 1121 ah->ar_op = htons(ARPOP_REPLY); 1122 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 1123 switch (ifp->if_type) { 1124 case IFT_IEEE1394: 1125 /* 1126 * ieee1394 arp reply is broadcast 1127 */ 1128 m->m_flags &= ~M_MCAST; 1129 m->m_flags |= M_BCAST; 1130 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + ah->ar_hln; 1131 break; 1132 1133 default: 1134 m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */ 1135 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); 1136 break; 1137 } 1138 m->m_pkthdr.len = m->m_len; 1139 sa.sa_family = AF_ARP; 1140 sa.sa_len = 2; 1141 arpstat.as_sndtotal++; 1142 arpstat.as_sndreply++; 1143 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); 1144 return; 1145 } 1146 1147 /* 1148 * Free an arp entry. 1149 */ 1150 static void arptfree(struct llinfo_arp *la) 1151 { 1152 struct rtentry *rt = la->la_rt; 1153 struct sockaddr_dl *sdl; 1154 1155 ARP_LOCK_CHECK(); 1156 1157 if (rt == 0) 1158 panic("arptfree"); 1159 if (rt->rt_refcnt > 0 && (sdl = SDL(rt->rt_gateway)) && 1160 sdl->sdl_family == AF_LINK) { 1161 sdl->sdl_alen = 0; 1162 la->la_asked = 0; 1163 rt->rt_flags &= ~RTF_REJECT; 1164 return; 1165 } 1166 rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0, rt_mask(rt), 1167 0, (struct rtentry **)0); 1168 } 1169 1170 /* 1171 * Lookup or enter a new address in arptab. 1172 */ 1173 static struct llinfo_arp * 1174 arplookup(struct mbuf *m, struct in_addr *addr, int create, int proxy) 1175 { 1176 struct arphdr *ah; 1177 struct ifnet *ifp = m->m_pkthdr.rcvif; 1178 struct rtentry *rt; 1179 static struct sockaddr_inarp sin; 1180 const char *why = 0; 1181 1182 ah = mtod(m, struct arphdr *); 1183 sin.sin_len = sizeof(sin); 1184 sin.sin_family = AF_INET; 1185 sin.sin_addr = *addr; 1186 sin.sin_other = proxy ? SIN_PROXY : 0; 1187 rt = rtalloc1(sintosa(&sin), create); 1188 if (rt == 0) 1189 return (0); 1190 rt->rt_refcnt--; 1191 1192 if ((rt->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) == RTF_LLINFO && 1193 rt->rt_gateway->sa_family == AF_LINK) 1194 return ((struct llinfo_arp *)rt->rt_llinfo); 1195 1196 1197 1198 if (create) { 1199 if (rt->rt_flags & RTF_GATEWAY) 1200 why = "host is not on local network"; 1201 else if ((rt->rt_flags & RTF_LLINFO) == 0) { 1202 arpstat.as_allocfail++; 1203 why = "could not allocate llinfo"; 1204 } else 1205 why = "gateway route is not ours"; 1206 log(LOG_DEBUG, "arplookup: unable to enter address" 1207 " for %s@%s on %s (%s)\n", 1208 in_fmtaddr(*addr), lla_snprintf(ar_sha(ah), ah->ar_hln), 1209 (ifp) ? ifp->if_xname : 0, why); 1210 if (rt->rt_refcnt <= 0 && (rt->rt_flags & RTF_CLONED) != 0) { 1211 rtrequest(RTM_DELETE, (struct sockaddr *)rt_key(rt), 1212 rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0); 1213 } 1214 } 1215 return (0); 1216 } 1217 1218 int 1219 arpioctl(u_long cmd, caddr_t data) 1220 { 1221 1222 return (EOPNOTSUPP); 1223 } 1224 1225 void 1226 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1227 { 1228 struct in_addr *ip; 1229 1230 /* 1231 * Warn the user if another station has this IP address, 1232 * but only if the interface IP address is not zero. 1233 */ 1234 ip = &IA_SIN(ifa)->sin_addr; 1235 if (!in_nullhost(*ip)) 1236 arprequest(ifp, ip, ip, LLADDR(ifp->if_sadl)); 1237 1238 ifa->ifa_rtrequest = arp_rtrequest; 1239 ifa->ifa_flags |= RTF_CLONING; 1240 } 1241 1242 /* 1243 * Called from 10 Mb/s Ethernet interrupt handlers 1244 * when ether packet type ETHERTYPE_REVARP 1245 * is received. Common length and type checks are done here, 1246 * then the protocol-specific routine is called. 1247 */ 1248 void 1249 revarpinput(struct mbuf *m) 1250 { 1251 struct arphdr *ar; 1252 1253 if (m->m_len < sizeof(struct arphdr)) 1254 goto out; 1255 ar = mtod(m, struct arphdr *); 1256 #if 0 /* XXX I don't think we need this... and it will prevent other LL */ 1257 if (ntohs(ar->ar_hrd) != ARPHRD_ETHER) 1258 goto out; 1259 #endif 1260 if (m->m_len < sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln)) 1261 goto out; 1262 switch (ntohs(ar->ar_pro)) { 1263 case ETHERTYPE_IP: 1264 case ETHERTYPE_IPTRAILERS: 1265 in_revarpinput(m); 1266 return; 1267 1268 default: 1269 break; 1270 } 1271 out: 1272 m_freem(m); 1273 } 1274 1275 /* 1276 * RARP for Internet protocols on 10 Mb/s Ethernet. 1277 * Algorithm is that given in RFC 903. 1278 * We are only using for bootstrap purposes to get an ip address for one of 1279 * our interfaces. Thus we support no user-interface. 1280 * 1281 * Since the contents of the RARP reply are specific to the interface that 1282 * sent the request, this code must ensure that they are properly associated. 1283 * 1284 * Note: also supports ARP via RARP packets, per the RFC. 1285 */ 1286 void 1287 in_revarpinput(struct mbuf *m) 1288 { 1289 struct ifnet *ifp; 1290 struct arphdr *ah; 1291 caddr_t tha; 1292 int op; 1293 1294 ah = mtod(m, struct arphdr *); 1295 op = ntohs(ah->ar_op); 1296 1297 switch (m->m_pkthdr.rcvif->if_type) { 1298 case IFT_IEEE1394: 1299 /* ARP without target hardware address is not supported */ 1300 goto out; 1301 default: 1302 break; 1303 } 1304 1305 switch (op) { 1306 case ARPOP_REQUEST: 1307 case ARPOP_REPLY: /* per RFC */ 1308 in_arpinput(m); 1309 return; 1310 case ARPOP_REVREPLY: 1311 break; 1312 case ARPOP_REVREQUEST: /* handled by rarpd(8) */ 1313 default: 1314 goto out; 1315 } 1316 if (!revarp_in_progress) 1317 goto out; 1318 ifp = m->m_pkthdr.rcvif; 1319 if (ifp != myip_ifp) /* !same interface */ 1320 goto out; 1321 if (myip_initialized) 1322 goto wake; 1323 tha = ar_tha(ah); 1324 KASSERT(tha); 1325 if (bcmp(tha, LLADDR(ifp->if_sadl), ifp->if_sadl->sdl_alen)) 1326 goto out; 1327 bcopy((caddr_t)ar_spa(ah), (caddr_t)&srv_ip, sizeof(srv_ip)); 1328 bcopy((caddr_t)ar_tpa(ah), (caddr_t)&myip, sizeof(myip)); 1329 myip_initialized = 1; 1330 wake: /* Do wakeup every time in case it was missed. */ 1331 wakeup((caddr_t)&myip); 1332 1333 out: 1334 m_freem(m); 1335 } 1336 1337 /* 1338 * Send a RARP request for the ip address of the specified interface. 1339 * The request should be RFC 903-compliant. 1340 */ 1341 void 1342 revarprequest(struct ifnet *ifp) 1343 { 1344 struct sockaddr sa; 1345 struct mbuf *m; 1346 struct arphdr *ah; 1347 caddr_t tha; 1348 1349 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 1350 return; 1351 MCLAIM(m, &arpdomain.dom_mowner); 1352 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) + 1353 2*ifp->if_addrlen; 1354 m->m_pkthdr.len = m->m_len; 1355 MH_ALIGN(m, m->m_len); 1356 ah = mtod(m, struct arphdr *); 1357 bzero((caddr_t)ah, m->m_len); 1358 ah->ar_pro = htons(ETHERTYPE_IP); 1359 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 1360 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 1361 ah->ar_op = htons(ARPOP_REVREQUEST); 1362 1363 bcopy(LLADDR(ifp->if_sadl), (caddr_t)ar_sha(ah), ah->ar_hln); 1364 tha = ar_tha(ah); 1365 KASSERT(tha); 1366 bcopy(LLADDR(ifp->if_sadl), tha, ah->ar_hln); 1367 1368 sa.sa_family = AF_ARP; 1369 sa.sa_len = 2; 1370 m->m_flags |= M_BCAST; 1371 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); 1372 1373 } 1374 1375 /* 1376 * RARP for the ip address of the specified interface, but also 1377 * save the ip address of the server that sent the answer. 1378 * Timeout if no response is received. 1379 */ 1380 int 1381 revarpwhoarewe(struct ifnet *ifp, struct in_addr *serv_in, 1382 struct in_addr *clnt_in) 1383 { 1384 int result, count = 20; 1385 1386 myip_initialized = 0; 1387 myip_ifp = ifp; 1388 1389 revarp_in_progress = 1; 1390 while (count--) { 1391 revarprequest(ifp); 1392 result = tsleep((caddr_t)&myip, PSOCK, "revarp", hz/2); 1393 if (result != EWOULDBLOCK) 1394 break; 1395 } 1396 revarp_in_progress = 0; 1397 1398 if (!myip_initialized) 1399 return ENETUNREACH; 1400 1401 bcopy((caddr_t)&srv_ip, serv_in, sizeof(*serv_in)); 1402 bcopy((caddr_t)&myip, clnt_in, sizeof(*clnt_in)); 1403 return 0; 1404 } 1405 1406 1407 1408 #ifdef DDB 1409 1410 #include <machine/db_machdep.h> 1411 #include <ddb/db_interface.h> 1412 #include <ddb/db_output.h> 1413 1414 static void 1415 db_print_sa(const struct sockaddr *sa) 1416 { 1417 int len; 1418 const u_char *p; 1419 1420 if (sa == 0) { 1421 db_printf("[NULL]"); 1422 return; 1423 } 1424 1425 p = (const u_char *)sa; 1426 len = sa->sa_len; 1427 db_printf("["); 1428 while (len > 0) { 1429 db_printf("%d", *p); 1430 p++; len--; 1431 if (len) db_printf(","); 1432 } 1433 db_printf("]\n"); 1434 } 1435 1436 static void 1437 db_print_ifa(struct ifaddr *ifa) 1438 { 1439 if (ifa == 0) 1440 return; 1441 db_printf(" ifa_addr="); 1442 db_print_sa(ifa->ifa_addr); 1443 db_printf(" ifa_dsta="); 1444 db_print_sa(ifa->ifa_dstaddr); 1445 db_printf(" ifa_mask="); 1446 db_print_sa(ifa->ifa_netmask); 1447 db_printf(" flags=0x%x,refcnt=%d,metric=%d\n", 1448 ifa->ifa_flags, 1449 ifa->ifa_refcnt, 1450 ifa->ifa_metric); 1451 } 1452 1453 static void 1454 db_print_llinfo(caddr_t li) 1455 { 1456 struct llinfo_arp *la; 1457 1458 if (li == 0) 1459 return; 1460 la = (struct llinfo_arp *)li; 1461 db_printf(" la_rt=%p la_hold=%p, la_asked=0x%lx\n", 1462 la->la_rt, la->la_hold, la->la_asked); 1463 } 1464 1465 /* 1466 * Function to pass to rn_walktree(). 1467 * Return non-zero error to abort walk. 1468 */ 1469 static int 1470 db_show_radix_node(struct radix_node *rn, void *w) 1471 { 1472 struct rtentry *rt = (struct rtentry *)rn; 1473 1474 db_printf("rtentry=%p", rt); 1475 1476 db_printf(" flags=0x%x refcnt=%d use=%ld expire=%ld\n", 1477 rt->rt_flags, rt->rt_refcnt, 1478 rt->rt_use, rt->rt_expire); 1479 1480 db_printf(" key="); db_print_sa(rt_key(rt)); 1481 db_printf(" mask="); db_print_sa(rt_mask(rt)); 1482 db_printf(" gw="); db_print_sa(rt->rt_gateway); 1483 1484 db_printf(" ifp=%p ", rt->rt_ifp); 1485 if (rt->rt_ifp) 1486 db_printf("(%s)", rt->rt_ifp->if_xname); 1487 else 1488 db_printf("(NULL)"); 1489 1490 db_printf(" ifa=%p\n", rt->rt_ifa); 1491 db_print_ifa(rt->rt_ifa); 1492 1493 db_printf(" genmask="); db_print_sa(rt->rt_genmask); 1494 1495 db_printf(" gwroute=%p llinfo=%p\n", 1496 rt->rt_gwroute, rt->rt_llinfo); 1497 db_print_llinfo(rt->rt_llinfo); 1498 1499 return (0); 1500 } 1501 1502 /* 1503 * Function to print all the route trees. 1504 * Use this from ddb: "show arptab" 1505 */ 1506 void 1507 db_show_arptab(db_expr_t addr, int have_addr, 1508 db_expr_t count, const char *modif) 1509 { 1510 struct radix_node_head *rnh; 1511 rnh = rt_tables[AF_INET]; 1512 db_printf("Route tree for AF_INET\n"); 1513 if (rnh == NULL) { 1514 db_printf(" (not initialized)\n"); 1515 return; 1516 } 1517 rn_walktree(rnh, db_show_radix_node, NULL); 1518 return; 1519 } 1520 #endif 1521 1522 SYSCTL_SETUP(sysctl_net_inet_arp_setup, "sysctl net.inet.arp subtree setup") 1523 { 1524 const struct sysctlnode *node; 1525 1526 sysctl_createv(clog, 0, NULL, NULL, 1527 CTLFLAG_PERMANENT, 1528 CTLTYPE_NODE, "net", NULL, 1529 NULL, 0, NULL, 0, 1530 CTL_NET, CTL_EOL); 1531 sysctl_createv(clog, 0, NULL, NULL, 1532 CTLFLAG_PERMANENT, 1533 CTLTYPE_NODE, "inet", NULL, 1534 NULL, 0, NULL, 0, 1535 CTL_NET, PF_INET, CTL_EOL); 1536 sysctl_createv(clog, 0, NULL, &node, 1537 CTLFLAG_PERMANENT, 1538 CTLTYPE_NODE, "arp", 1539 SYSCTL_DESCR("Address Resolution Protocol"), 1540 NULL, 0, NULL, 0, 1541 CTL_NET, PF_INET, CTL_CREATE, CTL_EOL); 1542 1543 sysctl_createv(clog, 0, NULL, NULL, 1544 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1545 CTLTYPE_INT, "prune", 1546 SYSCTL_DESCR("ARP cache pruning interval"), 1547 NULL, 0, &arpt_prune, 0, 1548 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1549 1550 sysctl_createv(clog, 0, NULL, NULL, 1551 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1552 CTLTYPE_INT, "keep", 1553 SYSCTL_DESCR("Valid ARP entry lifetime"), 1554 NULL, 0, &arpt_keep, 0, 1555 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1556 1557 sysctl_createv(clog, 0, NULL, NULL, 1558 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1559 CTLTYPE_INT, "down", 1560 SYSCTL_DESCR("Failed ARP entry lifetime"), 1561 NULL, 0, &arpt_down, 0, 1562 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1563 1564 sysctl_createv(clog, 0, NULL, NULL, 1565 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1566 CTLTYPE_INT, "refresh", 1567 SYSCTL_DESCR("ARP entry refresh interval"), 1568 NULL, 0, &arpt_refresh, 0, 1569 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1570 } 1571 1572 #endif /* INET */
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