1 /* $NetBSD: if_arp.c,v 1.98 2004/05/25 04:33:59 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 1.98 2004/05/25 04:33:59 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 "loop.h" 117 #include "arc.h" 118 #if NARC > 0 119 #include <net/if_arc.h> 120 #endif 121 #include "fddi.h" 122 #if NFDDI > 0 123 #include <net/if_fddi.h> 124 #endif 125 #include "token.h" 126 127 #define SIN(s) ((struct sockaddr_in *)s) 128 #define SDL(s) ((struct sockaddr_dl *)s) 129 #define SRP(s) ((struct sockaddr_inarp *)s) 130 131 /* 132 * ARP trailer negotiation. Trailer protocol is not IP specific, 133 * but ARP request/response use IP addresses. 134 */ 135 #define ETHERTYPE_IPTRAILERS ETHERTYPE_TRAIL 136 137 /* timer values */ 138 int arpt_prune = (5*60*1); /* walk list every 5 minutes */ 139 int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */ 140 int arpt_down = 20; /* once declared down, don't send for 20 secs */ 141 int arpt_refresh = (5*60); /* time left before refreshing */ 142 #define rt_expire rt_rmx.rmx_expire 143 #define rt_pksent rt_rmx.rmx_pksent 144 145 extern struct domain arpdomain; 146 147 static void arprequest __P((struct ifnet *, 148 struct in_addr *, struct in_addr *, u_int8_t *)); 149 static void arptfree __P((struct llinfo_arp *)); 150 static void arptimer __P((void *)); 151 static struct llinfo_arp *arplookup __P((struct mbuf *, struct in_addr *, 152 int, int)); 153 static void in_arpinput __P((struct mbuf *)); 154 155 #if NLOOP > 0 156 extern struct ifnet loif[NLOOP]; 157 #endif 158 LIST_HEAD(, llinfo_arp) llinfo_arp; 159 struct ifqueue arpintrq = {0, 0, 0, 50}; 160 int arp_inuse, arp_allocated, arp_intimer; 161 int arp_maxtries = 5; 162 int useloopback = 1; /* use loopback interface for local traffic */ 163 int arpinit_done = 0; 164 165 struct arpstat arpstat; 166 struct callout arptimer_ch; 167 168 169 /* revarp state */ 170 static struct in_addr myip, srv_ip; 171 static int myip_initialized = 0; 172 static int revarp_in_progress = 0; 173 static struct ifnet *myip_ifp = NULL; 174 175 #ifdef DDB 176 static void db_print_sa __P((const struct sockaddr *)); 177 static void db_print_ifa __P((struct ifaddr *)); 178 static void db_print_llinfo __P((caddr_t)); 179 static int db_show_radix_node __P((struct radix_node *, void *)); 180 #endif 181 182 /* 183 * this should be elsewhere. 184 */ 185 186 static char * 187 lla_snprintf __P((u_int8_t *, int)); 188 189 static char * 190 lla_snprintf(adrp, len) 191 u_int8_t *adrp; 192 int len; 193 { 194 #define NUMBUFS 3 195 static char buf[NUMBUFS][16*3]; 196 static int bnum = 0; 197 static const char hexdigits[] = { 198 '0','1','2','3','4','5','6','7', 199 '8','9','a','b','c','d','e','f' 200 }; 201 202 int i; 203 char *p; 204 205 p = buf[bnum]; 206 207 *p++ = hexdigits[(*adrp)>>4]; 208 *p++ = hexdigits[(*adrp++)&0xf]; 209 210 for (i=1; i<len && i<16; i++) { 211 *p++ = ':'; 212 *p++ = hexdigits[(*adrp)>>4]; 213 *p++ = hexdigits[(*adrp++)&0xf]; 214 } 215 216 *p = 0; 217 p = buf[bnum]; 218 bnum = (bnum + 1) % NUMBUFS; 219 return p; 220 } 221 222 const struct protosw arpsw[] = { 223 { 0, 0, 0, 0, 224 0, 0, 0, 0, 225 0, 226 0, 0, 0, arp_drain, 227 } 228 }; 229 230 231 struct domain arpdomain = 232 { PF_ARP, "arp", 0, 0, 0, 233 arpsw, &arpsw[sizeof(arpsw)/sizeof(arpsw[0])] 234 }; 235 236 /* 237 * ARP table locking. 238 * 239 * to prevent lossage vs. the arp_drain routine (which may be called at 240 * any time, including in a device driver context), we do two things: 241 * 242 * 1) manipulation of la->la_hold is done at splnet() (for all of 243 * about two instructions). 244 * 245 * 2) manipulation of the arp table's linked list is done under the 246 * protection of the ARP_LOCK; if arp_drain() or arptimer is called 247 * while the arp table is locked, we punt and try again later. 248 */ 249 250 static int arp_locked; 251 static __inline int arp_lock_try __P((int)); 252 static __inline void arp_unlock __P((void)); 253 254 static __inline int 255 arp_lock_try(int recurse) 256 { 257 int s; 258 259 /* 260 * Use splvm() -- we're blocking things that would cause 261 * mbuf allocation. 262 */ 263 s = splvm(); 264 if (!recurse && arp_locked) { 265 splx(s); 266 return (0); 267 } 268 arp_locked++; 269 splx(s); 270 return (1); 271 } 272 273 static __inline void 274 arp_unlock() 275 { 276 int s; 277 278 s = splvm(); 279 arp_locked--; 280 splx(s); 281 } 282 283 #ifdef DIAGNOSTIC 284 #define ARP_LOCK(recurse) \ 285 do { \ 286 if (arp_lock_try(recurse) == 0) { \ 287 printf("%s:%d: arp already locked\n", __FILE__, __LINE__); \ 288 panic("arp_lock"); \ 289 } \ 290 } while (/*CONSTCOND*/ 0) 291 #define ARP_LOCK_CHECK() \ 292 do { \ 293 if (arp_locked == 0) { \ 294 printf("%s:%d: arp lock not held\n", __FILE__, __LINE__); \ 295 panic("arp lock check"); \ 296 } \ 297 } while (/*CONSTCOND*/ 0) 298 #else 299 #define ARP_LOCK(x) (void) arp_lock_try(x) 300 #define ARP_LOCK_CHECK() /* nothing */ 301 #endif 302 303 #define ARP_UNLOCK() arp_unlock() 304 305 /* 306 * ARP protocol drain routine. Called when memory is in short supply. 307 * Called at splvm(); 308 */ 309 310 void 311 arp_drain() 312 { 313 struct llinfo_arp *la, *nla; 314 int count = 0; 315 struct mbuf *mold; 316 317 if (arp_lock_try(0) == 0) { 318 printf("arp_drain: locked; punting\n"); 319 return; 320 } 321 322 for (la = LIST_FIRST(&llinfo_arp); la != 0; la = nla) { 323 nla = LIST_NEXT(la, la_list); 324 325 mold = la->la_hold; 326 la->la_hold = 0; 327 328 if (mold) { 329 m_freem(mold); 330 count++; 331 } 332 } 333 ARP_UNLOCK(); 334 arpstat.as_dfrdropped += count; 335 } 336 337 338 /* 339 * Timeout routine. Age arp_tab entries periodically. 340 */ 341 /* ARGSUSED */ 342 static void 343 arptimer(arg) 344 void *arg; 345 { 346 int s; 347 struct llinfo_arp *la, *nla; 348 349 s = splsoftnet(); 350 351 if (arp_lock_try(0) == 0) { 352 /* get it later.. */ 353 splx(s); 354 return; 355 } 356 357 callout_reset(&arptimer_ch, arpt_prune * hz, arptimer, NULL); 358 for (la = LIST_FIRST(&llinfo_arp); la != 0; la = nla) { 359 struct rtentry *rt = la->la_rt; 360 361 nla = LIST_NEXT(la, la_list); 362 if (rt->rt_expire == 0) 363 continue; 364 if ((rt->rt_expire - time.tv_sec) < arpt_refresh && 365 rt->rt_pksent > (time.tv_sec - arpt_keep)) { 366 /* 367 * If the entry has been used during since last 368 * refresh, try to renew it before deleting. 369 */ 370 arprequest(rt->rt_ifp, 371 &SIN(rt->rt_ifa->ifa_addr)->sin_addr, 372 &SIN(rt_key(rt))->sin_addr, 373 LLADDR(rt->rt_ifp->if_sadl)); 374 } else if (rt->rt_expire <= time.tv_sec) 375 arptfree(la); /* timer has expired; clear */ 376 } 377 378 ARP_UNLOCK(); 379 380 splx(s); 381 } 382 383 /* 384 * Parallel to llc_rtrequest. 385 */ 386 void 387 arp_rtrequest(req, rt, info) 388 int req; 389 struct rtentry *rt; 390 struct rt_addrinfo *info; 391 { 392 struct sockaddr *gate = rt->rt_gateway; 393 struct llinfo_arp *la = (struct llinfo_arp *)rt->rt_llinfo; 394 static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK}; 395 size_t allocsize; 396 struct mbuf *mold; 397 int s; 398 struct in_ifaddr *ia; 399 struct ifaddr *ifa; 400 401 if (!arpinit_done) { 402 arpinit_done = 1; 403 /* 404 * We generate expiration times from time.tv_sec 405 * so avoid accidently creating permanent routes. 406 */ 407 if (time.tv_sec == 0) { 408 time.tv_sec++; 409 } 410 callout_init(&arptimer_ch); 411 callout_reset(&arptimer_ch, hz, arptimer, NULL); 412 } 413 414 if ((rt->rt_flags & RTF_GATEWAY) != 0) { 415 if (req != RTM_ADD) 416 return; 417 418 /* 419 * linklayers with particular link MTU limitation. 420 */ 421 switch(rt->rt_ifp->if_type) { 422 #if NFDDI > 0 423 case IFT_FDDI: 424 if (rt->rt_ifp->if_mtu > FDDIIPMTU) 425 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 426 break; 427 #endif 428 #if NARC > 0 429 case IFT_ARCNET: 430 { 431 int arcipifmtu; 432 433 if (rt->rt_ifp->if_flags & IFF_LINK0) 434 arcipifmtu = arc_ipmtu; 435 else 436 arcipifmtu = ARCMTU; 437 if (rt->rt_ifp->if_mtu > arcipifmtu) 438 rt->rt_rmx.rmx_mtu = arcipifmtu; 439 break; 440 } 441 #endif 442 } 443 return; 444 } 445 446 ARP_LOCK(1); /* we may already be locked here. */ 447 448 switch (req) { 449 450 case RTM_ADD: 451 /* 452 * XXX: If this is a manually added route to interface 453 * such as older version of routed or gated might provide, 454 * restore cloning bit. 455 */ 456 if ((rt->rt_flags & RTF_HOST) == 0 && 457 SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff) 458 rt->rt_flags |= RTF_CLONING; 459 if (rt->rt_flags & RTF_CLONING) { 460 /* 461 * Case 1: This route should come from a route to iface. 462 */ 463 rt_setgate(rt, rt_key(rt), 464 (struct sockaddr *)&null_sdl); 465 gate = rt->rt_gateway; 466 SDL(gate)->sdl_type = rt->rt_ifp->if_type; 467 SDL(gate)->sdl_index = rt->rt_ifp->if_index; 468 /* 469 * Give this route an expiration time, even though 470 * it's a "permanent" route, so that routes cloned 471 * from it do not need their expiration time set. 472 */ 473 rt->rt_expire = time.tv_sec; 474 /* 475 * linklayers with particular link MTU limitation. 476 */ 477 switch (rt->rt_ifp->if_type) { 478 #if NFDDI > 0 479 case IFT_FDDI: 480 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 481 (rt->rt_rmx.rmx_mtu > FDDIIPMTU || 482 (rt->rt_rmx.rmx_mtu == 0 && 483 rt->rt_ifp->if_mtu > FDDIIPMTU))) 484 rt->rt_rmx.rmx_mtu = FDDIIPMTU; 485 break; 486 #endif 487 #if NARC > 0 488 case IFT_ARCNET: 489 { 490 int arcipifmtu; 491 if (rt->rt_ifp->if_flags & IFF_LINK0) 492 arcipifmtu = arc_ipmtu; 493 else 494 arcipifmtu = ARCMTU; 495 496 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 && 497 (rt->rt_rmx.rmx_mtu > arcipifmtu || 498 (rt->rt_rmx.rmx_mtu == 0 && 499 rt->rt_ifp->if_mtu > arcipifmtu))) 500 rt->rt_rmx.rmx_mtu = arcipifmtu; 501 break; 502 } 503 #endif 504 } 505 break; 506 } 507 /* Announce a new entry if requested. */ 508 if (rt->rt_flags & RTF_ANNOUNCE) 509 arprequest(rt->rt_ifp, 510 &SIN(rt_key(rt))->sin_addr, 511 &SIN(rt_key(rt))->sin_addr, 512 (u_char *)LLADDR(SDL(gate))); 513 /*FALLTHROUGH*/ 514 case RTM_RESOLVE: 515 if (gate->sa_family != AF_LINK || 516 gate->sa_len < sizeof(null_sdl)) { 517 log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n"); 518 break; 519 } 520 SDL(gate)->sdl_type = rt->rt_ifp->if_type; 521 SDL(gate)->sdl_index = rt->rt_ifp->if_index; 522 if (la != 0) 523 break; /* This happens on a route change */ 524 /* 525 * Case 2: This route may come from cloning, or a manual route 526 * add with a LL address. 527 */ 528 switch (SDL(gate)->sdl_type) { 529 #if NTOKEN > 0 530 case IFT_ISO88025: 531 allocsize = sizeof(*la) + sizeof(struct token_rif); 532 break; 533 #endif /* NTOKEN > 0 */ 534 default: 535 allocsize = sizeof(*la); 536 } 537 R_Malloc(la, struct llinfo_arp *, allocsize); 538 rt->rt_llinfo = (caddr_t)la; 539 if (la == 0) { 540 log(LOG_DEBUG, "arp_rtrequest: malloc failed\n"); 541 break; 542 } 543 arp_inuse++, arp_allocated++; 544 Bzero(la, allocsize); 545 la->la_rt = rt; 546 rt->rt_flags |= RTF_LLINFO; 547 LIST_INSERT_HEAD(&llinfo_arp, la, la_list); 548 549 INADDR_TO_IA(SIN(rt_key(rt))->sin_addr, ia); 550 while (ia && ia->ia_ifp != rt->rt_ifp) 551 NEXT_IA_WITH_SAME_ADDR(ia); 552 if (ia) { 553 /* 554 * This test used to be 555 * if (loif.if_flags & IFF_UP) 556 * It allowed local traffic to be forced through 557 * the hardware by configuring the loopback down. 558 * However, it causes problems during network 559 * configuration for boards that can't receive 560 * packets they send. It is now necessary to clear 561 * "useloopback" and remove the route to force 562 * traffic out to the hardware. 563 * 564 * In 4.4BSD, the above "if" statement checked 565 * rt->rt_ifa against rt_key(rt). It was changed 566 * to the current form so that we can provide a 567 * better support for multiple IPv4 addresses on a 568 * interface. 569 */ 570 rt->rt_expire = 0; 571 Bcopy(LLADDR(rt->rt_ifp->if_sadl), 572 LLADDR(SDL(gate)), 573 SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen); 574 #if NLOOP > 0 575 if (useloopback) 576 rt->rt_ifp = &loif[0]; 577 #endif 578 /* 579 * make sure to set rt->rt_ifa to the interface 580 * address we are using, otherwise we will have trouble 581 * with source address selection. 582 */ 583 ifa = &ia->ia_ifa; 584 if (ifa != rt->rt_ifa) { 585 IFAFREE(rt->rt_ifa); 586 IFAREF(ifa); 587 rt->rt_ifa = ifa; 588 } 589 } 590 break; 591 592 case RTM_DELETE: 593 if (la == 0) 594 break; 595 arp_inuse--; 596 LIST_REMOVE(la, la_list); 597 rt->rt_llinfo = 0; 598 rt->rt_flags &= ~RTF_LLINFO; 599 600 s = splnet(); 601 mold = la->la_hold; 602 la->la_hold = 0; 603 splx(s); 604 605 if (mold) 606 m_freem(mold); 607 608 Free((caddr_t)la); 609 } 610 ARP_UNLOCK(); 611 } 612 613 /* 614 * Broadcast an ARP request. Caller specifies: 615 * - arp header source ip address 616 * - arp header target ip address 617 * - arp header source ethernet address 618 */ 619 static void 620 arprequest(ifp, sip, tip, enaddr) 621 struct ifnet *ifp; 622 struct in_addr *sip, *tip; 623 u_int8_t *enaddr; 624 { 625 struct mbuf *m; 626 struct arphdr *ah; 627 struct sockaddr sa; 628 629 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 630 return; 631 MCLAIM(m, &arpdomain.dom_mowner); 632 switch (ifp->if_type) { 633 case IFT_IEEE1394: 634 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 635 ifp->if_addrlen; 636 break; 637 default: 638 m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 639 2 * ifp->if_addrlen; 640 break; 641 } 642 m->m_pkthdr.len = m->m_len; 643 MH_ALIGN(m, m->m_len); 644 ah = mtod(m, struct arphdr *); 645 bzero((caddr_t)ah, m->m_len); 646 switch (ifp->if_type) { 647 case IFT_IEEE1394: /* RFC2734 */ 648 /* fill it now for ar_tpa computation */ 649 ah->ar_hrd = htons(ARPHRD_IEEE1394); 650 break; 651 default: 652 /* ifp->if_output will fill ar_hrd */ 653 break; 654 } 655 ah->ar_pro = htons(ETHERTYPE_IP); 656 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 657 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 658 ah->ar_op = htons(ARPOP_REQUEST); 659 bcopy((caddr_t)enaddr, (caddr_t)ar_sha(ah), ah->ar_hln); 660 bcopy((caddr_t)sip, (caddr_t)ar_spa(ah), ah->ar_pln); 661 bcopy((caddr_t)tip, (caddr_t)ar_tpa(ah), ah->ar_pln); 662 sa.sa_family = AF_ARP; 663 sa.sa_len = 2; 664 m->m_flags |= M_BCAST; 665 arpstat.as_sndtotal++; 666 arpstat.as_sndrequest++; 667 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); 668 } 669 670 /* 671 * Resolve an IP address into an ethernet address. If success, 672 * desten is filled in. If there is no entry in arptab, 673 * set one up and broadcast a request for the IP address. 674 * Hold onto this mbuf and resend it once the address 675 * is finally resolved. A return value of 1 indicates 676 * that desten has been filled in and the packet should be sent 677 * normally; a 0 return indicates that the packet has been 678 * taken over here, either now or for later transmission. 679 */ 680 int 681 arpresolve(ifp, rt, m, dst, desten) 682 struct ifnet *ifp; 683 struct rtentry *rt; 684 struct mbuf *m; 685 struct sockaddr *dst; 686 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.tv_sec) && 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.tv_sec; /* 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.tv_sec; 745 } 746 #endif 747 if (rt->rt_expire) { 748 rt->rt_flags &= ~RTF_REJECT; 749 if (la->la_asked == 0 || rt->rt_expire != time.tv_sec) { 750 rt->rt_expire = time.tv_sec; 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 LLADDR(ifp->if_sadl)); 756 else { 757 rt->rt_flags |= RTF_REJECT; 758 rt->rt_expire += arpt_down; 759 la->la_asked = 0; 760 } 761 } 762 } 763 return (0); 764 } 765 766 /* 767 * Common length and type checks are done here, 768 * then the protocol-specific routine is called. 769 */ 770 void 771 arpintr() 772 { 773 struct mbuf *m; 774 struct arphdr *ar; 775 int s; 776 int arplen; 777 778 while (arpintrq.ifq_head) { 779 s = splnet(); 780 IF_DEQUEUE(&arpintrq, m); 781 splx(s); 782 if (m == 0 || (m->m_flags & M_PKTHDR) == 0) 783 panic("arpintr"); 784 785 MCLAIM(m, &arpdomain.dom_mowner); 786 arpstat.as_rcvtotal++; 787 788 /* 789 * First, make sure we have at least struct arphdr. 790 */ 791 if (m->m_len < sizeof(struct arphdr) || 792 (ar = mtod(m, struct arphdr *)) == NULL) 793 goto badlen; 794 795 switch (m->m_pkthdr.rcvif->if_type) { 796 case IFT_IEEE1394: 797 arplen = sizeof(struct arphdr) + 798 ar->ar_hln + 2 * ar->ar_pln; 799 break; 800 default: 801 arplen = sizeof(struct arphdr) + 802 2 * ar->ar_hln + 2 * ar->ar_pln; 803 break; 804 } 805 806 if (/* XXX ntohs(ar->ar_hrd) == ARPHRD_ETHER && */ 807 m->m_len >= arplen) 808 switch (ntohs(ar->ar_pro)) { 809 case ETHERTYPE_IP: 810 case ETHERTYPE_IPTRAILERS: 811 in_arpinput(m); 812 continue; 813 default: 814 arpstat.as_rcvbadproto++; 815 } 816 else { 817 badlen: 818 arpstat.as_rcvbadlen++; 819 } 820 m_freem(m); 821 } 822 } 823 824 /* 825 * ARP for Internet protocols on 10 Mb/s Ethernet. 826 * Algorithm is that given in RFC 826. 827 * In addition, a sanity check is performed on the sender 828 * protocol address, to catch impersonators. 829 * We no longer handle negotiations for use of trailer protocol: 830 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent 831 * along with IP replies if we wanted trailers sent to us, 832 * and also sent them in response to IP replies. 833 * This allowed either end to announce the desire to receive 834 * trailer packets. 835 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, 836 * but formerly didn't normally send requests. 837 */ 838 static void 839 in_arpinput(m) 840 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 struct sockaddr_dl *sdl; 851 struct sockaddr sa; 852 struct in_addr isaddr, itaddr, myaddr; 853 int op; 854 struct mbuf *mold; 855 int s; 856 857 ah = mtod(m, struct arphdr *); 858 op = ntohs(ah->ar_op); 859 860 /* 861 * Fix up ah->ar_hrd if necessary, before using ar_tha() or 862 * ar_tpa(). 863 */ 864 switch (ifp->if_type) { 865 case IFT_IEEE1394: 866 if (ntohs(ah->ar_hrd) == ARPHRD_IEEE1394) 867 ; 868 else { 869 /* XXX this is to make sure we compute ar_tha right */ 870 /* XXX check ar_hrd more strictly? */ 871 ah->ar_hrd = htons(ARPHRD_IEEE1394); 872 } 873 break; 874 default: 875 /* XXX check ar_hrd? */ 876 break; 877 } 878 879 bcopy((caddr_t)ar_spa(ah), (caddr_t)&isaddr, sizeof (isaddr)); 880 bcopy((caddr_t)ar_tpa(ah), (caddr_t)&itaddr, sizeof (itaddr)); 881 882 if (m->m_flags & (M_BCAST|M_MCAST)) 883 arpstat.as_rcvmcast++; 884 885 /* 886 * If the target IP address is zero, ignore the packet. 887 * This prevents the code below from tring to answer 888 * when we are using IP address zero (booting). 889 */ 890 if (in_nullhost(itaddr)) { 891 arpstat.as_rcvzerotpa++; 892 goto out; 893 } 894 895 /* 896 * If the source IP address is zero, this is most likely a 897 * confused host trying to use IP address zero. (Windoze?) 898 * XXX: Should we bother trying to reply to these? 899 */ 900 if (in_nullhost(isaddr)) { 901 arpstat.as_rcvzerospa++; 902 goto out; 903 } 904 905 /* 906 * Search for a matching interface address 907 * or any address on the interface to use 908 * as a dummy address in the rest of this function 909 */ 910 INADDR_TO_IA(itaddr, ia); 911 while (ia != NULL) { 912 if (ia->ia_ifp == m->m_pkthdr.rcvif) 913 break; 914 915 #if NBRIDGE > 0 916 /* 917 * If the interface we received the packet on 918 * is part of a bridge, check to see if we need 919 * to "bridge" the packet to ourselves at this 920 * layer. Note we still prefer a perfect match, 921 * but allow this weaker match if necessary. 922 */ 923 if (m->m_pkthdr.rcvif->if_bridge != NULL && 924 m->m_pkthdr.rcvif->if_bridge == ia->ia_ifp->if_bridge) 925 bridge_ia = ia; 926 #endif /* NBRIDGE > 0 */ 927 928 NEXT_IA_WITH_SAME_ADDR(ia); 929 } 930 931 #if NBRIDGE > 0 932 if (ia == NULL && bridge_ia != NULL) { 933 ia = bridge_ia; 934 ifp = bridge_ia->ia_ifp; 935 } 936 #endif 937 938 if (ia == NULL) { 939 INADDR_TO_IA(isaddr, ia); 940 while ((ia != NULL) && ia->ia_ifp != m->m_pkthdr.rcvif) 941 NEXT_IA_WITH_SAME_ADDR(ia); 942 943 if (ia == NULL) { 944 IFP_TO_IA(ifp, ia); 945 if (ia == NULL) { 946 arpstat.as_rcvnoint++; 947 goto out; 948 } 949 } 950 } 951 952 myaddr = ia->ia_addr.sin_addr; 953 954 /* XXX checks for bridge case? */ 955 if (!bcmp((caddr_t)ar_sha(ah), LLADDR(ifp->if_sadl), 956 ifp->if_addrlen)) { 957 arpstat.as_rcvlocalsha++; 958 goto out; /* it's from me, ignore it. */ 959 } 960 961 /* XXX checks for bridge case? */ 962 if (!bcmp((caddr_t)ar_sha(ah), (caddr_t)ifp->if_broadcastaddr, 963 ifp->if_addrlen)) { 964 arpstat.as_rcvbcastsha++; 965 log(LOG_ERR, 966 "%s: arp: link address is broadcast for IP address %s!\n", 967 ifp->if_xname, in_fmtaddr(isaddr)); 968 goto out; 969 } 970 971 if (in_hosteq(isaddr, myaddr)) { 972 arpstat.as_rcvlocalspa++; 973 log(LOG_ERR, 974 "duplicate IP address %s sent from link address %s\n", 975 in_fmtaddr(isaddr), lla_snprintf(ar_sha(ah), ah->ar_hln)); 976 itaddr = myaddr; 977 goto reply; 978 } 979 la = arplookup(m, &isaddr, in_hosteq(itaddr, myaddr), 0); 980 if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) { 981 if (sdl->sdl_alen && 982 bcmp((caddr_t)ar_sha(ah), LLADDR(sdl), sdl->sdl_alen)) { 983 if (rt->rt_flags & RTF_STATIC) { 984 arpstat.as_rcvoverperm++; 985 log(LOG_INFO, 986 "%s tried to overwrite permanent arp info" 987 " for %s\n", 988 lla_snprintf(ar_sha(ah), ah->ar_hln), 989 in_fmtaddr(isaddr)); 990 goto out; 991 } else if (rt->rt_ifp != ifp) { 992 arpstat.as_rcvoverint++; 993 log(LOG_INFO, 994 "%s on %s tried to overwrite " 995 "arp info for %s on %s\n", 996 lla_snprintf(ar_sha(ah), ah->ar_hln), 997 ifp->if_xname, in_fmtaddr(isaddr), 998 rt->rt_ifp->if_xname); 999 goto out; 1000 } else { 1001 arpstat.as_rcvover++; 1002 log(LOG_INFO, 1003 "arp info overwritten for %s by %s\n", 1004 in_fmtaddr(isaddr), 1005 lla_snprintf(ar_sha(ah), ah->ar_hln)); 1006 } 1007 } 1008 /* 1009 * sanity check for the address length. 1010 * XXX this does not work for protocols with variable address 1011 * length. -is 1012 */ 1013 if (sdl->sdl_alen && 1014 sdl->sdl_alen != ah->ar_hln) { 1015 arpstat.as_rcvlenchg++; 1016 log(LOG_WARNING, 1017 "arp from %s: new addr len %d, was %d", 1018 in_fmtaddr(isaddr), ah->ar_hln, sdl->sdl_alen); 1019 } 1020 if (ifp->if_addrlen != ah->ar_hln) { 1021 arpstat.as_rcvbadlen++; 1022 log(LOG_WARNING, 1023 "arp from %s: addr len: new %d, i/f %d (ignored)", 1024 in_fmtaddr(isaddr), ah->ar_hln, 1025 ifp->if_addrlen); 1026 goto reply; 1027 } 1028 #if NTOKEN > 0 1029 /* 1030 * XXX uses m_data and assumes the complete answer including 1031 * XXX token-ring headers is in the same buf 1032 */ 1033 if (ifp->if_type == IFT_ISO88025) { 1034 struct token_header *trh; 1035 1036 trh = (struct token_header *)M_TRHSTART(m); 1037 if (trh->token_shost[0] & TOKEN_RI_PRESENT) { 1038 struct token_rif *rif; 1039 size_t riflen; 1040 1041 rif = TOKEN_RIF(trh); 1042 riflen = (ntohs(rif->tr_rcf) & 1043 TOKEN_RCF_LEN_MASK) >> 8; 1044 1045 if (riflen > 2 && 1046 riflen < sizeof(struct token_rif) && 1047 (riflen & 1) == 0) { 1048 rif->tr_rcf ^= htons(TOKEN_RCF_DIRECTION); 1049 rif->tr_rcf &= htons(~TOKEN_RCF_BROADCAST_MASK); 1050 bcopy(rif, TOKEN_RIF(la), riflen); 1051 } 1052 } 1053 } 1054 #endif /* NTOKEN > 0 */ 1055 bcopy((caddr_t)ar_sha(ah), LLADDR(sdl), 1056 sdl->sdl_alen = ah->ar_hln); 1057 if (rt->rt_expire) 1058 rt->rt_expire = time.tv_sec + arpt_keep; 1059 rt->rt_flags &= ~RTF_REJECT; 1060 la->la_asked = 0; 1061 1062 s = splnet(); 1063 mold = la->la_hold; 1064 la->la_hold = 0; 1065 splx(s); 1066 1067 if (mold) { 1068 arpstat.as_dfrsent++; 1069 (*ifp->if_output)(ifp, mold, rt_key(rt), rt); 1070 } 1071 } 1072 reply: 1073 if (op != ARPOP_REQUEST) { 1074 if (op == ARPOP_REPLY) 1075 arpstat.as_rcvreply++; 1076 out: 1077 m_freem(m); 1078 return; 1079 } 1080 arpstat.as_rcvrequest++; 1081 if (in_hosteq(itaddr, myaddr)) { 1082 /* I am the target */ 1083 if (ar_tha(ah)) 1084 bcopy((caddr_t)ar_sha(ah), (caddr_t)ar_tha(ah), 1085 ah->ar_hln); 1086 bcopy(LLADDR(ifp->if_sadl), (caddr_t)ar_sha(ah), ah->ar_hln); 1087 } else { 1088 la = arplookup(m, &itaddr, 0, SIN_PROXY); 1089 if (la == 0) 1090 goto out; 1091 rt = la->la_rt; 1092 if (ar_tha(ah)) 1093 bcopy((caddr_t)ar_sha(ah), (caddr_t)ar_tha(ah), 1094 ah->ar_hln); 1095 sdl = SDL(rt->rt_gateway); 1096 bcopy(LLADDR(sdl), (caddr_t)ar_sha(ah), ah->ar_hln); 1097 } 1098 1099 bcopy((caddr_t)ar_spa(ah), (caddr_t)ar_tpa(ah), ah->ar_pln); 1100 bcopy((caddr_t)&itaddr, (caddr_t)ar_spa(ah), ah->ar_pln); 1101 ah->ar_op = htons(ARPOP_REPLY); 1102 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 1103 switch (ifp->if_type) { 1104 case IFT_IEEE1394: 1105 /* 1106 * ieee1394 arp reply is broadcast 1107 */ 1108 m->m_flags &= ~M_MCAST; 1109 m->m_flags |= M_BCAST; 1110 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + ah->ar_hln; 1111 break; 1112 1113 default: 1114 m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */ 1115 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); 1116 break; 1117 } 1118 m->m_pkthdr.len = m->m_len; 1119 sa.sa_family = AF_ARP; 1120 sa.sa_len = 2; 1121 arpstat.as_sndtotal++; 1122 arpstat.as_sndreply++; 1123 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); 1124 return; 1125 } 1126 1127 /* 1128 * Free an arp entry. 1129 */ 1130 static void 1131 arptfree(la) 1132 struct llinfo_arp *la; 1133 { 1134 struct rtentry *rt = la->la_rt; 1135 struct sockaddr_dl *sdl; 1136 1137 ARP_LOCK_CHECK(); 1138 1139 if (rt == 0) 1140 panic("arptfree"); 1141 if (rt->rt_refcnt > 0 && (sdl = SDL(rt->rt_gateway)) && 1142 sdl->sdl_family == AF_LINK) { 1143 sdl->sdl_alen = 0; 1144 la->la_asked = 0; 1145 rt->rt_flags &= ~RTF_REJECT; 1146 return; 1147 } 1148 rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0, rt_mask(rt), 1149 0, (struct rtentry **)0); 1150 } 1151 1152 /* 1153 * Lookup or enter a new address in arptab. 1154 */ 1155 static struct llinfo_arp * 1156 arplookup(m, addr, create, proxy) 1157 struct mbuf *m; 1158 struct in_addr *addr; 1159 int create, proxy; 1160 { 1161 struct arphdr *ah; 1162 struct ifnet *ifp = m->m_pkthdr.rcvif; 1163 struct rtentry *rt; 1164 static struct sockaddr_inarp sin; 1165 const char *why = 0; 1166 1167 ah = mtod(m, struct arphdr *); 1168 sin.sin_len = sizeof(sin); 1169 sin.sin_family = AF_INET; 1170 sin.sin_addr = *addr; 1171 sin.sin_other = proxy ? SIN_PROXY : 0; 1172 rt = rtalloc1(sintosa(&sin), create); 1173 if (rt == 0) 1174 return (0); 1175 rt->rt_refcnt--; 1176 1177 if (rt->rt_flags & RTF_GATEWAY) 1178 why = "host is not on local network"; 1179 else if ((rt->rt_flags & RTF_LLINFO) == 0) { 1180 arpstat.as_allocfail++; 1181 why = "could not allocate llinfo"; 1182 } else if (rt->rt_gateway->sa_family != AF_LINK) 1183 why = "gateway route is not ours"; 1184 else 1185 return ((struct llinfo_arp *)rt->rt_llinfo); 1186 1187 if (create) { 1188 log(LOG_DEBUG, "arplookup: unable to enter address" 1189 " for %s@%s on %s (%s)\n", 1190 in_fmtaddr(*addr), lla_snprintf(ar_sha(ah), ah->ar_hln), 1191 (ifp) ? ifp->if_xname : 0, why); 1192 if (rt->rt_refcnt <= 0 && (rt->rt_flags & RTF_CLONED) != 0) { 1193 rtrequest(RTM_DELETE, (struct sockaddr *)rt_key(rt), 1194 rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0); 1195 } 1196 } 1197 return (0); 1198 } 1199 1200 int 1201 arpioctl(cmd, data) 1202 u_long cmd; 1203 caddr_t data; 1204 { 1205 1206 return (EOPNOTSUPP); 1207 } 1208 1209 void 1210 arp_ifinit(ifp, ifa) 1211 struct ifnet *ifp; 1212 struct ifaddr *ifa; 1213 { 1214 struct in_addr *ip; 1215 1216 /* 1217 * Warn the user if another station has this IP address, 1218 * but only if the interface IP address is not zero. 1219 */ 1220 ip = &IA_SIN(ifa)->sin_addr; 1221 if (!in_nullhost(*ip)) 1222 arprequest(ifp, ip, ip, LLADDR(ifp->if_sadl)); 1223 1224 ifa->ifa_rtrequest = arp_rtrequest; 1225 ifa->ifa_flags |= RTF_CLONING; 1226 } 1227 1228 /* 1229 * Called from 10 Mb/s Ethernet interrupt handlers 1230 * when ether packet type ETHERTYPE_REVARP 1231 * is received. Common length and type checks are done here, 1232 * then the protocol-specific routine is called. 1233 */ 1234 void 1235 revarpinput(m) 1236 struct mbuf *m; 1237 { 1238 struct arphdr *ar; 1239 1240 if (m->m_len < sizeof(struct arphdr)) 1241 goto out; 1242 ar = mtod(m, struct arphdr *); 1243 #if 0 /* XXX I don't think we need this... and it will prevent other LL */ 1244 if (ntohs(ar->ar_hrd) != ARPHRD_ETHER) 1245 goto out; 1246 #endif 1247 if (m->m_len < sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln)) 1248 goto out; 1249 switch (ntohs(ar->ar_pro)) { 1250 case ETHERTYPE_IP: 1251 case ETHERTYPE_IPTRAILERS: 1252 in_revarpinput(m); 1253 return; 1254 1255 default: 1256 break; 1257 } 1258 out: 1259 m_freem(m); 1260 } 1261 1262 /* 1263 * RARP for Internet protocols on 10 Mb/s Ethernet. 1264 * Algorithm is that given in RFC 903. 1265 * We are only using for bootstrap purposes to get an ip address for one of 1266 * our interfaces. Thus we support no user-interface. 1267 * 1268 * Since the contents of the RARP reply are specific to the interface that 1269 * sent the request, this code must ensure that they are properly associated. 1270 * 1271 * Note: also supports ARP via RARP packets, per the RFC. 1272 */ 1273 void 1274 in_revarpinput(m) 1275 struct mbuf *m; 1276 { 1277 struct ifnet *ifp; 1278 struct arphdr *ah; 1279 int op; 1280 1281 ah = mtod(m, struct arphdr *); 1282 op = ntohs(ah->ar_op); 1283 1284 switch (m->m_pkthdr.rcvif->if_type) { 1285 case IFT_IEEE1394: 1286 /* ARP without target hardware address is not supported */ 1287 goto out; 1288 default: 1289 break; 1290 } 1291 1292 switch (op) { 1293 case ARPOP_REQUEST: 1294 case ARPOP_REPLY: /* per RFC */ 1295 in_arpinput(m); 1296 return; 1297 case ARPOP_REVREPLY: 1298 break; 1299 case ARPOP_REVREQUEST: /* handled by rarpd(8) */ 1300 default: 1301 goto out; 1302 } 1303 if (!revarp_in_progress) 1304 goto out; 1305 ifp = m->m_pkthdr.rcvif; 1306 if (ifp != myip_ifp) /* !same interface */ 1307 goto out; 1308 if (myip_initialized) 1309 goto wake; 1310 if (bcmp(ar_tha(ah), LLADDR(ifp->if_sadl), ifp->if_sadl->sdl_alen)) 1311 goto out; 1312 bcopy((caddr_t)ar_spa(ah), (caddr_t)&srv_ip, sizeof(srv_ip)); 1313 bcopy((caddr_t)ar_tpa(ah), (caddr_t)&myip, sizeof(myip)); 1314 myip_initialized = 1; 1315 wake: /* Do wakeup every time in case it was missed. */ 1316 wakeup((caddr_t)&myip); 1317 1318 out: 1319 m_freem(m); 1320 } 1321 1322 /* 1323 * Send a RARP request for the ip address of the specified interface. 1324 * The request should be RFC 903-compliant. 1325 */ 1326 void 1327 revarprequest(ifp) 1328 struct ifnet *ifp; 1329 { 1330 struct sockaddr sa; 1331 struct mbuf *m; 1332 struct arphdr *ah; 1333 1334 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 1335 return; 1336 MCLAIM(m, &arpdomain.dom_mowner); 1337 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) + 1338 2*ifp->if_addrlen; 1339 m->m_pkthdr.len = m->m_len; 1340 MH_ALIGN(m, m->m_len); 1341 ah = mtod(m, struct arphdr *); 1342 bzero((caddr_t)ah, m->m_len); 1343 ah->ar_pro = htons(ETHERTYPE_IP); 1344 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 1345 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 1346 ah->ar_op = htons(ARPOP_REVREQUEST); 1347 1348 bcopy(LLADDR(ifp->if_sadl), (caddr_t)ar_sha(ah), ah->ar_hln); 1349 bcopy(LLADDR(ifp->if_sadl), (caddr_t)ar_tha(ah), ah->ar_hln); 1350 1351 sa.sa_family = AF_ARP; 1352 sa.sa_len = 2; 1353 m->m_flags |= M_BCAST; 1354 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); 1355 1356 } 1357 1358 /* 1359 * RARP for the ip address of the specified interface, but also 1360 * save the ip address of the server that sent the answer. 1361 * Timeout if no response is received. 1362 */ 1363 int 1364 revarpwhoarewe(ifp, serv_in, clnt_in) 1365 struct ifnet *ifp; 1366 struct in_addr *serv_in; 1367 struct in_addr *clnt_in; 1368 { 1369 int result, count = 20; 1370 1371 myip_initialized = 0; 1372 myip_ifp = ifp; 1373 1374 revarp_in_progress = 1; 1375 while (count--) { 1376 revarprequest(ifp); 1377 result = tsleep((caddr_t)&myip, PSOCK, "revarp", hz/2); 1378 if (result != EWOULDBLOCK) 1379 break; 1380 } 1381 revarp_in_progress = 0; 1382 1383 if (!myip_initialized) 1384 return ENETUNREACH; 1385 1386 bcopy((caddr_t)&srv_ip, serv_in, sizeof(*serv_in)); 1387 bcopy((caddr_t)&myip, clnt_in, sizeof(*clnt_in)); 1388 return 0; 1389 } 1390 1391 1392 1393 #ifdef DDB 1394 1395 #include <machine/db_machdep.h> 1396 #include <ddb/db_interface.h> 1397 #include <ddb/db_output.h> 1398 static void 1399 db_print_sa(sa) 1400 const struct sockaddr *sa; 1401 { 1402 int len; 1403 u_char *p; 1404 1405 if (sa == 0) { 1406 db_printf("[NULL]"); 1407 return; 1408 } 1409 1410 p = (u_char*)sa; 1411 len = sa->sa_len; 1412 db_printf("["); 1413 while (len > 0) { 1414 db_printf("%d", *p); 1415 p++; len--; 1416 if (len) db_printf(","); 1417 } 1418 db_printf("]\n"); 1419 } 1420 static void 1421 db_print_ifa(ifa) 1422 struct ifaddr *ifa; 1423 { 1424 if (ifa == 0) 1425 return; 1426 db_printf(" ifa_addr="); 1427 db_print_sa(ifa->ifa_addr); 1428 db_printf(" ifa_dsta="); 1429 db_print_sa(ifa->ifa_dstaddr); 1430 db_printf(" ifa_mask="); 1431 db_print_sa(ifa->ifa_netmask); 1432 db_printf(" flags=0x%x,refcnt=%d,metric=%d\n", 1433 ifa->ifa_flags, 1434 ifa->ifa_refcnt, 1435 ifa->ifa_metric); 1436 } 1437 static void 1438 db_print_llinfo(li) 1439 caddr_t li; 1440 { 1441 struct llinfo_arp *la; 1442 1443 if (li == 0) 1444 return; 1445 la = (struct llinfo_arp *)li; 1446 db_printf(" la_rt=%p la_hold=%p, la_asked=0x%lx\n", 1447 la->la_rt, la->la_hold, la->la_asked); 1448 } 1449 /* 1450 * Function to pass to rn_walktree(). 1451 * Return non-zero error to abort walk. 1452 */ 1453 static int 1454 db_show_radix_node(rn, w) 1455 struct radix_node *rn; 1456 void *w; 1457 { 1458 struct rtentry *rt = (struct rtentry *)rn; 1459 1460 db_printf("rtentry=%p", rt); 1461 1462 db_printf(" flags=0x%x refcnt=%d use=%ld expire=%ld\n", 1463 rt->rt_flags, rt->rt_refcnt, 1464 rt->rt_use, rt->rt_expire); 1465 1466 db_printf(" key="); db_print_sa(rt_key(rt)); 1467 db_printf(" mask="); db_print_sa(rt_mask(rt)); 1468 db_printf(" gw="); db_print_sa(rt->rt_gateway); 1469 1470 db_printf(" ifp=%p ", rt->rt_ifp); 1471 if (rt->rt_ifp) 1472 db_printf("(%s)", rt->rt_ifp->if_xname); 1473 else 1474 db_printf("(NULL)"); 1475 1476 db_printf(" ifa=%p\n", rt->rt_ifa); 1477 db_print_ifa(rt->rt_ifa); 1478 1479 db_printf(" genmask="); db_print_sa(rt->rt_genmask); 1480 1481 db_printf(" gwroute=%p llinfo=%p\n", 1482 rt->rt_gwroute, rt->rt_llinfo); 1483 db_print_llinfo(rt->rt_llinfo); 1484 1485 return (0); 1486 } 1487 /* 1488 * Function to print all the route trees. 1489 * Use this from ddb: "show arptab" 1490 */ 1491 void 1492 db_show_arptab(addr, have_addr, count, modif) 1493 db_expr_t addr; 1494 int have_addr; 1495 db_expr_t count; 1496 char * modif; 1497 { 1498 struct radix_node_head *rnh; 1499 rnh = rt_tables[AF_INET]; 1500 db_printf("Route tree for AF_INET\n"); 1501 if (rnh == NULL) { 1502 db_printf(" (not initialized)\n"); 1503 return; 1504 } 1505 rn_walktree(rnh, db_show_radix_node, NULL); 1506 return; 1507 } 1508 #endif 1509 1510 SYSCTL_SETUP(sysctl_net_inet_arp_setup, "sysctl net.inet.arp subtree setup") 1511 { 1512 struct sysctlnode *node; 1513 1514 sysctl_createv(clog, 0, NULL, NULL, 1515 CTLFLAG_PERMANENT, 1516 CTLTYPE_NODE, "net", NULL, 1517 NULL, 0, NULL, 0, 1518 CTL_NET, CTL_EOL); 1519 sysctl_createv(clog, 0, NULL, NULL, 1520 CTLFLAG_PERMANENT, 1521 CTLTYPE_NODE, "inet", NULL, 1522 NULL, 0, NULL, 0, 1523 CTL_NET, PF_INET, CTL_EOL); 1524 sysctl_createv(clog, 0, NULL, &node, 1525 CTLFLAG_PERMANENT, 1526 CTLTYPE_NODE, "arp", 1527 SYSCTL_DESCR("Address Resolution Protocol"), 1528 NULL, 0, NULL, 0, 1529 CTL_NET, PF_INET, CTL_CREATE, CTL_EOL); 1530 1531 sysctl_createv(clog, 0, NULL, NULL, 1532 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1533 CTLTYPE_INT, "prune", 1534 SYSCTL_DESCR("ARP cache pruning interval"), 1535 NULL, 0, &arpt_prune, 0, 1536 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1537 1538 sysctl_createv(clog, 0, NULL, NULL, 1539 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1540 CTLTYPE_INT, "keep", 1541 SYSCTL_DESCR("Valid ARP entry lifetime"), 1542 NULL, 0, &arpt_keep, 0, 1543 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1544 1545 sysctl_createv(clog, 0, NULL, NULL, 1546 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1547 CTLTYPE_INT, "down", 1548 SYSCTL_DESCR("Failed ARP entry lifetime"), 1549 NULL, 0, &arpt_down, 0, 1550 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1551 1552 sysctl_createv(clog, 0, NULL, NULL, 1553 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1554 CTLTYPE_INT, "refresh", 1555 SYSCTL_DESCR("ARP entry refresh interval"), 1556 NULL, 0, &arpt_refresh, 0, 1557 CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL); 1558 } 1559 1560 #endif /* INET */ 1561