1 /* 2 * Copyright (c) 2004, 2005 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Jeffrey M. Hsu. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of The DragonFly Project nor the names of its 16 * contributors may be used to endorse or promote products derived 17 * from this software without specific, prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 22 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 23 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 24 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 25 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 26 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 27 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 28 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 29 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * Copyright (c) 1982, 1986, 1988, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 3. All advertising materials mentioning features or use of this software 46 * must display the following acknowledgement: 47 * This product includes software developed by the University of 48 * California, Berkeley and its contributors. 49 * 4. Neither the name of the University nor the names of its contributors 50 * may be used to endorse or promote products derived from this software 51 * without specific prior written permission. 52 * 53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 63 * SUCH DAMAGE. 64 * 65 * @(#)if_ether.c 8.1 (Berkeley) 6/10/93 66 * $FreeBSD: src/sys/netinet/if_ether.c,v 1.64.2.23 2003/04/11 07:23:15 fjoe Exp $ 67 * $DragonFly: src/sys/netinet/if_ether.c,v 1.38 2007/05/24 20:51:22 dillon Exp $ 68 */ 69 70 /* 71 * Ethernet address resolution protocol. 72 * TODO: 73 * add "inuse/lock" bit (or ref. count) along with valid bit 74 */ 75 76 #include "opt_inet.h" 77 78 #include <sys/param.h> 79 #include <sys/kernel.h> 80 #include <sys/queue.h> 81 #include <sys/sysctl.h> 82 #include <sys/systm.h> 83 #include <sys/mbuf.h> 84 #include <sys/malloc.h> 85 #include <sys/socket.h> 86 #include <sys/syslog.h> 87 88 #include <net/if.h> 89 #include <net/if_dl.h> 90 #include <net/if_types.h> 91 #include <net/route.h> 92 #include <net/netisr.h> 93 #include <net/if_llc.h> 94 95 #include <netinet/in.h> 96 #include <netinet/in_var.h> 97 #include <netinet/if_ether.h> 98 99 #include <net/if_arc.h> 100 #include <net/iso88025.h> 101 102 #include <sys/thread2.h> 103 #include <sys/msgport2.h> 104 #include <net/netmsg2.h> 105 106 107 #define SIN(s) ((struct sockaddr_in *)s) 108 #define SDL(s) ((struct sockaddr_dl *)s) 109 110 SYSCTL_DECL(_net_link_ether); 111 SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, ""); 112 113 /* timer values */ 114 static int arpt_prune = (5*60*1); /* walk list every 5 minutes */ 115 static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */ 116 static int arpt_down = 20; /* once declared down, don't send for 20 sec */ 117 118 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, prune_intvl, CTLFLAG_RW, 119 &arpt_prune, 0, ""); 120 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW, 121 &arpt_keep, 0, ""); 122 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, host_down_time, CTLFLAG_RW, 123 &arpt_down, 0, ""); 124 125 #define rt_expire rt_rmx.rmx_expire 126 127 struct llinfo_arp { 128 LIST_ENTRY(llinfo_arp) la_le; 129 struct rtentry *la_rt; 130 struct mbuf *la_hold; /* last packet until resolved/timeout */ 131 u_short la_preempt; /* countdown for pre-expiry arps */ 132 u_short la_asked; /* #times we QUERIED following expiration */ 133 }; 134 135 static LIST_HEAD(, llinfo_arp) llinfo_arp_list[MAXCPU]; 136 137 static int arp_maxtries = 5; 138 static int useloopback = 1; /* use loopback interface for local traffic */ 139 static int arp_proxyall = 0; 140 141 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW, 142 &arp_maxtries, 0, ""); 143 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW, 144 &useloopback, 0, ""); 145 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW, 146 &arp_proxyall, 0, ""); 147 148 static void arp_rtrequest (int, struct rtentry *, struct rt_addrinfo *); 149 static void arprequest (struct ifnet *, 150 struct in_addr *, struct in_addr *, u_char *); 151 static void arpintr(struct netmsg *); 152 static void arptfree (struct llinfo_arp *); 153 static void arptimer (void *); 154 static struct llinfo_arp 155 *arplookup (in_addr_t addr, boolean_t create, boolean_t proxy); 156 #ifdef INET 157 static void in_arpinput (struct mbuf *); 158 #endif 159 160 static struct callout arptimer_ch[MAXCPU]; 161 162 /* 163 * Timeout routine. Age arp_tab entries periodically. 164 */ 165 /* ARGSUSED */ 166 static void 167 arptimer(void *ignored_arg) 168 { 169 struct llinfo_arp *la, *nla; 170 171 crit_enter(); 172 LIST_FOREACH_MUTABLE(la, &llinfo_arp_list[mycpuid], la_le, nla) { 173 if (la->la_rt->rt_expire && la->la_rt->rt_expire <= time_second) 174 arptfree(la); 175 } 176 callout_reset(&arptimer_ch[mycpuid], arpt_prune * hz, arptimer, NULL); 177 crit_exit(); 178 } 179 180 /* 181 * Parallel to llc_rtrequest. 182 */ 183 static void 184 arp_rtrequest(int req, struct rtentry *rt, struct rt_addrinfo *info) 185 { 186 struct sockaddr *gate = rt->rt_gateway; 187 struct llinfo_arp *la = rt->rt_llinfo; 188 189 struct sockaddr_dl null_sdl = { sizeof null_sdl, AF_LINK }; 190 static boolean_t arpinit_done[MAXCPU]; 191 192 if (!arpinit_done[mycpuid]) { 193 arpinit_done[mycpuid] = TRUE; 194 callout_init(&arptimer_ch[mycpuid]); 195 callout_reset(&arptimer_ch[mycpuid], hz, arptimer, NULL); 196 } 197 if (rt->rt_flags & RTF_GATEWAY) 198 return; 199 200 switch (req) { 201 case RTM_ADD: 202 /* 203 * XXX: If this is a manually added route to interface 204 * such as older version of routed or gated might provide, 205 * restore cloning bit. 206 */ 207 if (!(rt->rt_flags & RTF_HOST) && 208 SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff) 209 rt->rt_flags |= RTF_CLONING; 210 if (rt->rt_flags & RTF_CLONING) { 211 /* 212 * Case 1: This route should come from a route to iface. 213 */ 214 rt_setgate(rt, rt_key(rt), 215 (struct sockaddr *)&null_sdl); 216 gate = rt->rt_gateway; 217 SDL(gate)->sdl_type = rt->rt_ifp->if_type; 218 SDL(gate)->sdl_index = rt->rt_ifp->if_index; 219 rt->rt_expire = time_second; 220 break; 221 } 222 /* Announce a new entry if requested. */ 223 if (rt->rt_flags & RTF_ANNOUNCE) 224 arprequest(rt->rt_ifp, 225 &SIN(rt_key(rt))->sin_addr, 226 &SIN(rt_key(rt))->sin_addr, 227 LLADDR(SDL(gate))); 228 /*FALLTHROUGH*/ 229 case RTM_RESOLVE: 230 if (gate->sa_family != AF_LINK || 231 gate->sa_len < sizeof(struct sockaddr_dl)) { 232 log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n"); 233 break; 234 } 235 SDL(gate)->sdl_type = rt->rt_ifp->if_type; 236 SDL(gate)->sdl_index = rt->rt_ifp->if_index; 237 if (la != NULL) 238 break; /* This happens on a route change */ 239 /* 240 * Case 2: This route may come from cloning, or a manual route 241 * add with a LL address. 242 */ 243 R_Malloc(la, struct llinfo_arp *, sizeof *la); 244 rt->rt_llinfo = la; 245 if (la == NULL) { 246 log(LOG_DEBUG, "arp_rtrequest: malloc failed\n"); 247 break; 248 } 249 bzero(la, sizeof *la); 250 la->la_rt = rt; 251 rt->rt_flags |= RTF_LLINFO; 252 LIST_INSERT_HEAD(&llinfo_arp_list[mycpuid], la, la_le); 253 254 #ifdef INET 255 /* 256 * This keeps the multicast addresses from showing up 257 * in `arp -a' listings as unresolved. It's not actually 258 * functional. Then the same for broadcast. 259 */ 260 if (IN_MULTICAST(ntohl(SIN(rt_key(rt))->sin_addr.s_addr)) && 261 rt->rt_ifp->if_type != IFT_ARCNET) { 262 ETHER_MAP_IP_MULTICAST(&SIN(rt_key(rt))->sin_addr, 263 LLADDR(SDL(gate))); 264 SDL(gate)->sdl_alen = 6; 265 rt->rt_expire = 0; 266 } 267 if (in_broadcast(SIN(rt_key(rt))->sin_addr, rt->rt_ifp)) { 268 memcpy(LLADDR(SDL(gate)), rt->rt_ifp->if_broadcastaddr, 269 rt->rt_ifp->if_addrlen); 270 SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen; 271 rt->rt_expire = 0; 272 } 273 #endif 274 275 if (SIN(rt_key(rt))->sin_addr.s_addr == 276 (IA_SIN(rt->rt_ifa))->sin_addr.s_addr) { 277 /* 278 * This test used to be 279 * if (loif.if_flags & IFF_UP) 280 * It allowed local traffic to be forced 281 * through the hardware by configuring the 282 * loopback down. However, it causes problems 283 * during network configuration for boards 284 * that can't receive packets they send. It 285 * is now necessary to clear "useloopback" and 286 * remove the route to force traffic out to 287 * the hardware. 288 */ 289 rt->rt_expire = 0; 290 bcopy(IF_LLADDR(rt->rt_ifp), LLADDR(SDL(gate)), 291 SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen); 292 if (useloopback) 293 rt->rt_ifp = loif; 294 } 295 break; 296 297 case RTM_DELETE: 298 if (la == NULL) 299 break; 300 LIST_REMOVE(la, la_le); 301 rt->rt_llinfo = NULL; 302 rt->rt_flags &= ~RTF_LLINFO; 303 if (la->la_hold != NULL) 304 m_freem(la->la_hold); 305 Free(la); 306 } 307 } 308 309 /* 310 * Broadcast an ARP request. Caller specifies: 311 * - arp header source ip address 312 * - arp header target ip address 313 * - arp header source ethernet address 314 */ 315 static void 316 arprequest(struct ifnet *ifp, struct in_addr *sip, struct in_addr *tip, 317 u_char *enaddr) 318 { 319 struct mbuf *m; 320 struct ether_header *eh; 321 struct arc_header *arh; 322 struct arphdr *ah; 323 struct sockaddr sa; 324 static u_char llcx[] = { 0x82, 0x40, LLC_SNAP_LSAP, LLC_SNAP_LSAP, 325 LLC_UI, 0x00, 0x00, 0x00, 0x08, 0x06 }; 326 u_short ar_hrd; 327 328 if ((m = m_gethdr(MB_DONTWAIT, MT_DATA)) == NULL) 329 return; 330 m->m_pkthdr.rcvif = (struct ifnet *)NULL; 331 332 switch (ifp->if_type) { 333 case IFT_ARCNET: 334 ar_hrd = htons(ARPHRD_ARCNET); 335 336 m->m_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr)); 337 m->m_pkthdr.len = m->m_len; 338 MH_ALIGN(m, m->m_len); 339 340 arh = (struct arc_header *)sa.sa_data; 341 arh->arc_dhost = ifp->if_broadcastaddr[0]; 342 arh->arc_type = ARCTYPE_ARP; 343 344 ah = mtod(m, struct arphdr *); 345 break; 346 347 case IFT_ISO88025: 348 ar_hrd = htons(ARPHRD_IEEE802); 349 350 m->m_len = (sizeof llcx) + 351 arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr)); 352 m->m_pkthdr.len = m->m_len; 353 MH_ALIGN(m, m->m_len); 354 355 memcpy(mtod(m, caddr_t), llcx, sizeof llcx); 356 memcpy(sa.sa_data, ifp->if_broadcastaddr, ifp->if_addrlen); 357 memcpy(sa.sa_data + 6, enaddr, 6); 358 sa.sa_data[6] |= TR_RII; 359 sa.sa_data[12] = TR_AC; 360 sa.sa_data[13] = TR_LLC_FRAME; 361 362 ah = (struct arphdr *)(mtod(m, char *) + sizeof llcx); 363 break; 364 case IFT_FDDI: 365 case IFT_ETHER: 366 /* 367 * This may not be correct for types not explicitly 368 * listed, but this is our best guess 369 */ 370 default: 371 ar_hrd = htons(ARPHRD_ETHER); 372 373 m->m_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr)); 374 m->m_pkthdr.len = m->m_len; 375 MH_ALIGN(m, m->m_len); 376 377 eh = (struct ether_header *)sa.sa_data; 378 /* if_output() will not swap */ 379 eh->ether_type = htons(ETHERTYPE_ARP); 380 memcpy(eh->ether_dhost, ifp->if_broadcastaddr, ifp->if_addrlen); 381 382 ah = mtod(m, struct arphdr *); 383 break; 384 } 385 386 ah->ar_hrd = ar_hrd; 387 ah->ar_pro = htons(ETHERTYPE_IP); 388 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 389 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 390 ah->ar_op = htons(ARPOP_REQUEST); 391 memcpy(ar_sha(ah), enaddr, ah->ar_hln); 392 memset(ar_tha(ah), 0, ah->ar_hln); 393 memcpy(ar_spa(ah), sip, ah->ar_pln); 394 memcpy(ar_tpa(ah), tip, ah->ar_pln); 395 396 sa.sa_family = AF_UNSPEC; 397 sa.sa_len = sizeof sa; 398 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)NULL); 399 } 400 401 /* 402 * Resolve an IP address into an ethernet address. If success, 403 * desten is filled in. If there is no entry in arptab, 404 * set one up and broadcast a request for the IP address. 405 * Hold onto this mbuf and resend it once the address 406 * is finally resolved. A return value of 1 indicates 407 * that desten has been filled in and the packet should be sent 408 * normally; a 0 return indicates that the packet has been 409 * taken over here, either now or for later transmission. 410 */ 411 int 412 arpresolve( 413 struct ifnet *ifp, 414 struct rtentry *rt0, 415 struct mbuf *m, 416 struct sockaddr *dst, 417 u_char *desten) 418 { 419 struct rtentry *rt; 420 struct llinfo_arp *la = NULL; 421 struct sockaddr_dl *sdl; 422 423 if (m->m_flags & M_BCAST) { /* broadcast */ 424 memcpy(desten, ifp->if_broadcastaddr, ifp->if_addrlen); 425 return (1); 426 } 427 if (m->m_flags & M_MCAST && ifp->if_type != IFT_ARCNET) {/* multicast */ 428 ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten); 429 return (1); 430 } 431 if (rt0 != NULL) { 432 if (rt_llroute(dst, rt0, &rt) != 0) { 433 m_freem(m); 434 return 0; 435 } 436 la = rt->rt_llinfo; 437 } 438 if (la == NULL) { 439 la = arplookup(SIN(dst)->sin_addr.s_addr, TRUE, FALSE); 440 if (la != NULL) 441 rt = la->la_rt; 442 } 443 if (la == NULL || rt == NULL) { 444 log(LOG_DEBUG, "arpresolve: can't allocate llinfo for %s%s%s\n", 445 inet_ntoa(SIN(dst)->sin_addr), la ? "la" : " ", 446 rt ? "rt" : ""); 447 m_freem(m); 448 return (0); 449 } 450 sdl = SDL(rt->rt_gateway); 451 /* 452 * Check the address family and length is valid, the address 453 * is resolved; otherwise, try to resolve. 454 */ 455 if ((rt->rt_expire == 0 || rt->rt_expire > time_second) && 456 sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) { 457 /* 458 * If entry has an expiry time and it is approaching, 459 * see if we need to send an ARP request within this 460 * arpt_down interval. 461 */ 462 if ((rt->rt_expire != 0) && 463 (time_second + la->la_preempt > rt->rt_expire)) { 464 arprequest(ifp, 465 &SIN(rt->rt_ifa->ifa_addr)->sin_addr, 466 &SIN(dst)->sin_addr, 467 IF_LLADDR(ifp)); 468 la->la_preempt--; 469 } 470 471 bcopy(LLADDR(sdl), desten, sdl->sdl_alen); 472 return 1; 473 } 474 /* 475 * If ARP is disabled on this interface, stop. 476 * XXX 477 * Probably should not allocate empty llinfo struct if we are 478 * not going to be sending out an arp request. 479 */ 480 if (ifp->if_flags & IFF_NOARP) { 481 m_freem(m); 482 return (0); 483 } 484 /* 485 * There is an arptab entry, but no ethernet address 486 * response yet. Replace the held mbuf with this 487 * latest one. 488 */ 489 if (la->la_hold != NULL) 490 m_freem(la->la_hold); 491 la->la_hold = m; 492 if (rt->rt_expire || ((rt->rt_flags & RTF_STATIC) && !sdl->sdl_alen)) { 493 rt->rt_flags &= ~RTF_REJECT; 494 if (la->la_asked == 0 || rt->rt_expire != time_second) { 495 rt->rt_expire = time_second; 496 if (la->la_asked++ < arp_maxtries) { 497 arprequest(ifp, 498 &SIN(rt->rt_ifa->ifa_addr)->sin_addr, 499 &SIN(dst)->sin_addr, 500 IF_LLADDR(ifp)); 501 } else { 502 rt->rt_flags |= RTF_REJECT; 503 rt->rt_expire += arpt_down; 504 la->la_asked = 0; 505 la->la_preempt = arp_maxtries; 506 } 507 508 } 509 } 510 return (0); 511 } 512 513 /* 514 * Common length and type checks are done here, 515 * then the protocol-specific routine is called. 516 */ 517 static void 518 arpintr(struct netmsg *msg) 519 { 520 struct mbuf *m = ((struct netmsg_packet *)msg)->nm_packet; 521 struct arphdr *ar; 522 u_short ar_hrd; 523 524 if (m->m_len < sizeof(struct arphdr) && 525 ((m = m_pullup(m, sizeof(struct arphdr))) == NULL)) { 526 log(LOG_ERR, "arp: runt packet -- m_pullup failed\n"); 527 goto out2; 528 } 529 ar = mtod(m, struct arphdr *); 530 531 ar_hrd = ntohs(ar->ar_hrd); 532 if (ar_hrd != ARPHRD_ETHER && 533 ar_hrd != ARPHRD_IEEE802 && 534 ar_hrd != ARPHRD_ARCNET) { 535 log(LOG_ERR, 536 "arp: unknown hardware address format (0x%2D)\n", 537 (unsigned char *)&ar->ar_hrd, ""); 538 goto out1; 539 } 540 541 if (m->m_pkthdr.len < arphdr_len(ar) && 542 (m = m_pullup(m, arphdr_len(ar))) == NULL) { 543 log(LOG_ERR, "arp: runt packet\n"); 544 goto out1; 545 } 546 547 switch (ntohs(ar->ar_pro)) { 548 #ifdef INET 549 case ETHERTYPE_IP: 550 in_arpinput(m); 551 goto out2; 552 #endif 553 } 554 out1: 555 m_freem(m); 556 out2: 557 ; 558 /* msg was embedded in the mbuf, do not reply! */ 559 } 560 561 #ifdef INET 562 /* 563 * ARP for Internet protocols on 10 Mb/s Ethernet. 564 * Algorithm is that given in RFC 826. 565 * In addition, a sanity check is performed on the sender 566 * protocol address, to catch impersonators. 567 * We no longer handle negotiations for use of trailer protocol: 568 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent 569 * along with IP replies if we wanted trailers sent to us, 570 * and also sent them in response to IP replies. 571 * This allowed either end to announce the desire to receive 572 * trailer packets. 573 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, 574 * but formerly didn't normally send requests. 575 */ 576 static int log_arp_wrong_iface = 1; 577 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW, 578 &log_arp_wrong_iface, 0, 579 "log arp packets arriving on the wrong interface"); 580 581 static void 582 arp_update_oncpu(struct mbuf *m, in_addr_t saddr, boolean_t create, 583 boolean_t dologging) 584 { 585 struct arphdr *ah = mtod(m, struct arphdr *); 586 struct ifnet *ifp = m->m_pkthdr.rcvif; 587 struct llinfo_arp *la; 588 struct sockaddr_dl *sdl; 589 struct rtentry *rt; 590 int cpu = mycpuid; 591 592 la = arplookup(saddr, create, FALSE); 593 if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) { 594 struct in_addr isaddr = { saddr }; 595 596 /* the following is not an error when doing bridging */ 597 if (rt->rt_ifp != ifp) { 598 if (dologging && log_arp_wrong_iface && cpu == 0) { 599 log(LOG_ERR, 600 "arp: %s is on %s " 601 "but got reply from %*D on %s\n", 602 inet_ntoa(isaddr), 603 rt->rt_ifp->if_xname, 604 ifp->if_addrlen, (u_char *)ar_sha(ah), ":", 605 ifp->if_xname); 606 } 607 return; 608 } 609 if (sdl->sdl_alen && 610 bcmp(ar_sha(ah), LLADDR(sdl), sdl->sdl_alen)) { 611 if (rt->rt_expire != 0) { 612 if (dologging && cpu == 0) { 613 log(LOG_INFO, 614 "arp: %s moved from %*D to %*D on %s\n", 615 inet_ntoa(isaddr), 616 ifp->if_addrlen, (u_char *)LLADDR(sdl), 617 ":", ifp->if_addrlen, 618 (u_char *)ar_sha(ah), ":", 619 ifp->if_xname); 620 } 621 } else { 622 if (dologging && cpu == 0) { 623 log(LOG_ERR, 624 "arp: %*D attempts to modify permanent entry for %s on %s\n", 625 ifp->if_addrlen, (u_char *)ar_sha(ah), ":", 626 inet_ntoa(isaddr), ifp->if_xname); 627 } 628 return; 629 } 630 } 631 /* 632 * sanity check for the address length. 633 * XXX this does not work for protocols with variable address 634 * length. -is 635 */ 636 if (dologging && sdl->sdl_alen && sdl->sdl_alen != ah->ar_hln && 637 cpu == 0) 638 { 639 log(LOG_WARNING, 640 "arp from %*D: new addr len %d, was %d", 641 ifp->if_addrlen, (u_char *) ar_sha(ah), ":", 642 ah->ar_hln, sdl->sdl_alen); 643 } 644 if (ifp->if_addrlen != ah->ar_hln) { 645 if (dologging && cpu == 0) { 646 log(LOG_WARNING, 647 "arp from %*D: addr len: new %d, i/f %d (ignored)", 648 ifp->if_addrlen, (u_char *) ar_sha(ah), ":", 649 ah->ar_hln, ifp->if_addrlen); 650 } 651 return; 652 } 653 memcpy(LLADDR(sdl), ar_sha(ah), sdl->sdl_alen = ah->ar_hln); 654 /* 655 * If we receive an arp from a token-ring station over 656 * a token-ring nic then try to save the source 657 * routing info. 658 */ 659 if (ifp->if_type == IFT_ISO88025) { 660 struct iso88025_header *th = 661 (struct iso88025_header *)m->m_pkthdr.header; 662 struct iso88025_sockaddr_dl_data *trld = 663 SDL_ISO88025(sdl); 664 int rif_len; 665 666 rif_len = TR_RCF_RIFLEN(th->rcf); 667 if ((th->iso88025_shost[0] & TR_RII) && 668 (rif_len > 2)) { 669 trld->trld_rcf = th->rcf; 670 trld->trld_rcf ^= htons(TR_RCF_DIR); 671 memcpy(trld->trld_route, th->rd, rif_len - 2); 672 trld->trld_rcf &= ~htons(TR_RCF_BCST_MASK); 673 /* 674 * Set up source routing information for 675 * reply packet (XXX) 676 */ 677 m->m_data -= rif_len; 678 m->m_len += rif_len; 679 m->m_pkthdr.len += rif_len; 680 } else { 681 th->iso88025_shost[0] &= ~TR_RII; 682 trld->trld_rcf = 0; 683 } 684 m->m_data -= 8; 685 m->m_len += 8; 686 m->m_pkthdr.len += 8; 687 th->rcf = trld->trld_rcf; 688 } 689 if (rt->rt_expire != 0) 690 rt->rt_expire = time_second + arpt_keep; 691 rt->rt_flags &= ~RTF_REJECT; 692 la->la_asked = 0; 693 la->la_preempt = arp_maxtries; 694 695 /* 696 * This particular cpu might have been holding an mbuf 697 * pending ARP resolution. If so, transmit the mbuf now. 698 */ 699 if (la->la_hold != NULL) { 700 m_adj(la->la_hold, sizeof(struct ether_header)); 701 lwkt_serialize_enter(ifp->if_serializer); 702 (*ifp->if_output)(ifp, la->la_hold, rt_key(rt), rt); 703 lwkt_serialize_exit(ifp->if_serializer); 704 la->la_hold = NULL; 705 } 706 } 707 } 708 709 #ifdef SMP 710 711 struct netmsg_arp_update { 712 struct netmsg netmsg; 713 struct mbuf *m; 714 in_addr_t saddr; 715 boolean_t create; 716 }; 717 718 static void arp_update_msghandler(struct netmsg *netmsg); 719 720 #endif 721 722 /* 723 * Called from arpintr() - this routine is run from a single cpu. 724 */ 725 static void 726 in_arpinput(struct mbuf *m) 727 { 728 struct arphdr *ah; 729 struct ifnet *ifp = m->m_pkthdr.rcvif; 730 struct ether_header *eh; 731 struct arc_header *arh; 732 struct iso88025_header *th = (struct iso88025_header *)NULL; 733 struct rtentry *rt; 734 struct ifaddr *ifa; 735 struct in_ifaddr *ia; 736 struct sockaddr sa; 737 struct in_addr isaddr, itaddr, myaddr; 738 #ifdef SMP 739 struct netmsg_arp_update msg; 740 #endif 741 int op; 742 int req_len; 743 744 req_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr)); 745 if (m->m_len < req_len && (m = m_pullup(m, req_len)) == NULL) { 746 log(LOG_ERR, "in_arp: runt packet -- m_pullup failed\n"); 747 return; 748 } 749 750 ah = mtod(m, struct arphdr *); 751 op = ntohs(ah->ar_op); 752 memcpy(&isaddr, ar_spa(ah), sizeof isaddr); 753 memcpy(&itaddr, ar_tpa(ah), sizeof itaddr); 754 /* 755 * Check both target and sender IP addresses: 756 * 757 * If we receive the packet on the interface owning the address, 758 * then accept the address. 759 * 760 * For a bridge, we accept the address if the receive interface and 761 * the interface owning the address are on the same bridge. 762 * (This will change slightly when we have clusters of interfaces). 763 */ 764 LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) { 765 /* Skip all ia's which don't match */ 766 if (itaddr.s_addr != ia->ia_addr.sin_addr.s_addr) 767 continue; 768 769 if (ia->ia_ifp == ifp) 770 goto match; 771 772 if (ifp->if_bridge && ia->ia_ifp && 773 ifp->if_bridge == ia->ia_ifp->if_bridge) 774 goto match; 775 } 776 LIST_FOREACH(ia, INADDR_HASH(isaddr.s_addr), ia_hash) { 777 /* Skip all ia's which don't match */ 778 if (isaddr.s_addr != ia->ia_addr.sin_addr.s_addr) 779 continue; 780 781 if (ia->ia_ifp == ifp) 782 goto match; 783 784 if (ifp->if_bridge && ia->ia_ifp && 785 ifp->if_bridge == ia->ia_ifp->if_bridge) 786 goto match; 787 } 788 /* 789 * No match, use the first inet address on the receive interface 790 * as a dummy address for the rest of the function. 791 */ 792 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 793 if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET) { 794 ia = ifatoia(ifa); 795 goto match; 796 } 797 } 798 /* 799 * If we got here, we didn't find any suitable interface, 800 * so drop the packet. 801 */ 802 m_freem(m); 803 return; 804 805 match: 806 myaddr = ia->ia_addr.sin_addr; 807 if (!bcmp(ar_sha(ah), IF_LLADDR(ifp), ifp->if_addrlen)) { 808 m_freem(m); /* it's from me, ignore it. */ 809 return; 810 } 811 if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 812 log(LOG_ERR, 813 "arp: link address is broadcast for IP address %s!\n", 814 inet_ntoa(isaddr)); 815 m_freem(m); 816 return; 817 } 818 if (isaddr.s_addr == myaddr.s_addr && myaddr.s_addr != 0) { 819 log(LOG_ERR, 820 "arp: %*D is using my IP address %s!\n", 821 ifp->if_addrlen, (u_char *)ar_sha(ah), ":", 822 inet_ntoa(isaddr)); 823 itaddr = myaddr; 824 goto reply; 825 } 826 #ifdef SMP 827 netmsg_init(&msg.netmsg, &curthread->td_msgport, 0, 828 arp_update_msghandler); 829 msg.m = m; 830 msg.saddr = isaddr.s_addr; 831 msg.create = (itaddr.s_addr == myaddr.s_addr); 832 lwkt_domsg(rtable_portfn(0), &msg.netmsg.nm_lmsg, 0); 833 #endif 834 arp_update_oncpu(m, isaddr.s_addr, (itaddr.s_addr == myaddr.s_addr), 835 TRUE); 836 reply: 837 if (op != ARPOP_REQUEST) { 838 m_freem(m); 839 return; 840 } 841 if (itaddr.s_addr == myaddr.s_addr) { 842 /* I am the target */ 843 memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); 844 memcpy(ar_sha(ah), IF_LLADDR(ifp), ah->ar_hln); 845 } else { 846 struct llinfo_arp *la; 847 848 la = arplookup(itaddr.s_addr, FALSE, SIN_PROXY); 849 if (la == NULL) { 850 struct sockaddr_in sin; 851 852 if (!arp_proxyall) { 853 m_freem(m); 854 return; 855 } 856 857 bzero(&sin, sizeof sin); 858 sin.sin_family = AF_INET; 859 sin.sin_len = sizeof sin; 860 sin.sin_addr = itaddr; 861 862 rt = rtpurelookup((struct sockaddr *)&sin); 863 if (rt == NULL) { 864 m_freem(m); 865 return; 866 } 867 --rt->rt_refcnt; 868 /* 869 * Don't send proxies for nodes on the same interface 870 * as this one came out of, or we'll get into a fight 871 * over who claims what Ether address. 872 */ 873 if (rt->rt_ifp == ifp) { 874 m_freem(m); 875 return; 876 } 877 memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); 878 memcpy(ar_sha(ah), IF_LLADDR(ifp), ah->ar_hln); 879 #ifdef DEBUG_PROXY 880 kprintf("arp: proxying for %s\n", inet_ntoa(itaddr)); 881 #endif 882 } else { 883 struct sockaddr_dl *sdl; 884 885 rt = la->la_rt; 886 memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); 887 sdl = SDL(rt->rt_gateway); 888 memcpy(ar_sha(ah), LLADDR(sdl), ah->ar_hln); 889 } 890 } 891 892 memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); 893 memcpy(ar_spa(ah), &itaddr, ah->ar_pln); 894 ah->ar_op = htons(ARPOP_REPLY); 895 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 896 switch (ifp->if_type) { 897 case IFT_ARCNET: 898 arh = (struct arc_header *)sa.sa_data; 899 arh->arc_dhost = *ar_tha(ah); 900 arh->arc_type = ARCTYPE_ARP; 901 break; 902 case IFT_ISO88025: 903 /* Re-arrange the source/dest address */ 904 memcpy(th->iso88025_dhost, th->iso88025_shost, 905 sizeof th->iso88025_dhost); 906 memcpy(th->iso88025_shost, IF_LLADDR(ifp), 907 sizeof th->iso88025_shost); 908 /* Set the source routing bit if neccesary */ 909 if (th->iso88025_dhost[0] & TR_RII) { 910 th->iso88025_dhost[0] &= ~TR_RII; 911 if (TR_RCF_RIFLEN(th->rcf) > 2) 912 th->iso88025_shost[0] |= TR_RII; 913 } 914 /* Copy the addresses, ac and fc into sa_data */ 915 memcpy(sa.sa_data, th->iso88025_dhost, 916 (sizeof th->iso88025_dhost) * 2); 917 sa.sa_data[(sizeof th->iso88025_dhost) * 2] = TR_AC; 918 sa.sa_data[(sizeof th->iso88025_dhost) * 2 + 1] = TR_LLC_FRAME; 919 break; 920 case IFT_ETHER: 921 case IFT_FDDI: 922 /* 923 * May not be correct for types not explictly 924 * listed, but it is our best guess. 925 */ 926 default: 927 eh = (struct ether_header *)sa.sa_data; 928 memcpy(eh->ether_dhost, ar_tha(ah), sizeof eh->ether_dhost); 929 eh->ether_type = htons(ETHERTYPE_ARP); 930 break; 931 } 932 sa.sa_family = AF_UNSPEC; 933 sa.sa_len = sizeof sa; 934 lwkt_serialize_enter(ifp->if_serializer); 935 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); 936 lwkt_serialize_exit(ifp->if_serializer); 937 return; 938 } 939 940 #ifdef SMP 941 942 static 943 void 944 arp_update_msghandler(struct netmsg *netmsg) 945 { 946 struct netmsg_arp_update *msg = (struct netmsg_arp_update *)netmsg; 947 int nextcpu; 948 949 arp_update_oncpu(msg->m, msg->saddr, msg->create, FALSE); 950 951 nextcpu = mycpuid + 1; 952 if (nextcpu < ncpus) { 953 lwkt_forwardmsg(rtable_portfn(nextcpu), &msg->netmsg.nm_lmsg); 954 } else { 955 lwkt_replymsg(&msg->netmsg.nm_lmsg, 0); 956 } 957 } 958 959 #endif 960 961 #endif 962 963 /* 964 * Free an arp entry. If the arp entry is actively referenced or represents 965 * a static entry we only clear it back to an unresolved state, otherwise 966 * we destroy the entry entirely. 967 * 968 * Note that static entries are created when route add ... -interface is used 969 * to create an interface route to a (direct) destination. 970 */ 971 static void 972 arptfree(struct llinfo_arp *la) 973 { 974 struct rtentry *rt = la->la_rt; 975 struct sockaddr_dl *sdl; 976 977 if (rt == NULL) 978 panic("arptfree"); 979 sdl = SDL(rt->rt_gateway); 980 if (sdl != NULL && 981 ((rt->rt_refcnt > 0 && sdl->sdl_family == AF_LINK) || 982 (rt->rt_flags & RTF_STATIC))) { 983 sdl->sdl_alen = 0; 984 la->la_preempt = la->la_asked = 0; 985 rt->rt_flags &= ~RTF_REJECT; 986 return; 987 } 988 rtrequest(RTM_DELETE, rt_key(rt), NULL, rt_mask(rt), 0, NULL); 989 } 990 991 /* 992 * Lookup or enter a new address in arptab. 993 */ 994 static struct llinfo_arp * 995 arplookup(in_addr_t addr, boolean_t create, boolean_t proxy) 996 { 997 struct rtentry *rt; 998 struct sockaddr_inarp sin = { sizeof sin, AF_INET }; 999 const char *why = NULL; 1000 1001 sin.sin_addr.s_addr = addr; 1002 sin.sin_other = proxy ? SIN_PROXY : 0; 1003 if (create) 1004 rt = rtlookup((struct sockaddr *)&sin); 1005 else 1006 rt = rtpurelookup((struct sockaddr *)&sin); 1007 if (rt == NULL) 1008 return (NULL); 1009 rt->rt_refcnt--; 1010 1011 if (rt->rt_flags & RTF_GATEWAY) 1012 why = "host is not on local network"; 1013 else if (!(rt->rt_flags & RTF_LLINFO)) 1014 why = "could not allocate llinfo"; 1015 else if (rt->rt_gateway->sa_family != AF_LINK) 1016 why = "gateway route is not ours"; 1017 1018 if (why) { 1019 if (create) { 1020 log(LOG_DEBUG, "arplookup %s failed: %s\n", 1021 inet_ntoa(sin.sin_addr), why); 1022 } 1023 if (rt->rt_refcnt <= 0 && (rt->rt_flags & RTF_WASCLONED)) { 1024 /* No references to this route. Purge it. */ 1025 rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway, 1026 rt_mask(rt), rt->rt_flags, NULL); 1027 } 1028 return (NULL); 1029 } 1030 return (rt->rt_llinfo); 1031 } 1032 1033 void 1034 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1035 { 1036 if (IA_SIN(ifa)->sin_addr.s_addr != INADDR_ANY) 1037 arprequest(ifp, &IA_SIN(ifa)->sin_addr, &IA_SIN(ifa)->sin_addr, 1038 IF_LLADDR(ifp)); 1039 ifa->ifa_rtrequest = arp_rtrequest; 1040 ifa->ifa_flags |= RTF_CLONING; 1041 } 1042 1043 static void 1044 arp_init(void) 1045 { 1046 int cpu; 1047 1048 for (cpu = 0; cpu < ncpus2; cpu++) 1049 LIST_INIT(&llinfo_arp_list[cpu]); 1050 netisr_register(NETISR_ARP, cpu0_portfn, arpintr); 1051 } 1052 1053 SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0); 1054