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 1.39 2007/08/16 20:03:57 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 #include "opt_carp.h" 78 79 #include <sys/param.h> 80 #include <sys/kernel.h> 81 #include <sys/queue.h> 82 #include <sys/sysctl.h> 83 #include <sys/systm.h> 84 #include <sys/mbuf.h> 85 #include <sys/malloc.h> 86 #include <sys/socket.h> 87 #include <sys/syslog.h> 88 89 #include <net/if.h> 90 #include <net/if_dl.h> 91 #include <net/if_types.h> 92 #include <net/route.h> 93 #include <net/netisr.h> 94 #include <net/if_llc.h> 95 96 #include <netinet/in.h> 97 #include <netinet/in_var.h> 98 #include <netinet/if_ether.h> 99 100 #include <net/if_arc.h> 101 #include <net/iso88025.h> 102 103 #include <sys/thread2.h> 104 #include <sys/msgport2.h> 105 #include <net/netmsg2.h> 106 107 108 #ifdef CARP 109 #include <netinet/ip_carp.h> 110 #endif 111 112 #define SIN(s) ((struct sockaddr_in *)s) 113 #define SDL(s) ((struct sockaddr_dl *)s) 114 115 SYSCTL_DECL(_net_link_ether); 116 SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, ""); 117 118 /* timer values */ 119 static int arpt_prune = (5*60*1); /* walk list every 5 minutes */ 120 static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */ 121 static int arpt_down = 20; /* once declared down, don't send for 20 sec */ 122 123 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, prune_intvl, CTLFLAG_RW, 124 &arpt_prune, 0, ""); 125 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW, 126 &arpt_keep, 0, ""); 127 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, host_down_time, CTLFLAG_RW, 128 &arpt_down, 0, ""); 129 130 #define rt_expire rt_rmx.rmx_expire 131 132 struct llinfo_arp { 133 LIST_ENTRY(llinfo_arp) la_le; 134 struct rtentry *la_rt; 135 struct mbuf *la_hold; /* last packet until resolved/timeout */ 136 u_short la_preempt; /* countdown for pre-expiry arps */ 137 u_short la_asked; /* #times we QUERIED following expiration */ 138 }; 139 140 static LIST_HEAD(, llinfo_arp) llinfo_arp_list[MAXCPU]; 141 142 static int arp_maxtries = 5; 143 static int useloopback = 1; /* use loopback interface for local traffic */ 144 static int arp_proxyall = 0; 145 146 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW, 147 &arp_maxtries, 0, ""); 148 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW, 149 &useloopback, 0, ""); 150 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW, 151 &arp_proxyall, 0, ""); 152 153 void arprequest_acces(struct ifnet *ifp, struct in_addr *sip, struct in_addr *tip, u_char *enaddr); 154 static void arp_rtrequest (int, struct rtentry *, struct rt_addrinfo *); 155 static void arprequest (struct ifnet *, 156 struct in_addr *, struct in_addr *, u_char *); 157 static void arpintr(struct netmsg *); 158 static void arptfree (struct llinfo_arp *); 159 static void arptimer (void *); 160 static struct llinfo_arp 161 *arplookup (in_addr_t addr, boolean_t create, boolean_t proxy); 162 #ifdef INET 163 static void in_arpinput (struct mbuf *); 164 #endif 165 166 static struct callout arptimer_ch[MAXCPU]; 167 168 /* 169 * Timeout routine. Age arp_tab entries periodically. 170 */ 171 /* ARGSUSED */ 172 static void 173 arptimer(void *ignored_arg) 174 { 175 struct llinfo_arp *la, *nla; 176 177 crit_enter(); 178 LIST_FOREACH_MUTABLE(la, &llinfo_arp_list[mycpuid], la_le, nla) { 179 if (la->la_rt->rt_expire && la->la_rt->rt_expire <= time_second) 180 arptfree(la); 181 } 182 callout_reset(&arptimer_ch[mycpuid], arpt_prune * hz, arptimer, NULL); 183 crit_exit(); 184 } 185 186 /* 187 * Parallel to llc_rtrequest. 188 */ 189 static void 190 arp_rtrequest(int req, struct rtentry *rt, struct rt_addrinfo *info) 191 { 192 struct sockaddr *gate = rt->rt_gateway; 193 struct llinfo_arp *la = rt->rt_llinfo; 194 195 struct sockaddr_dl null_sdl = { sizeof null_sdl, AF_LINK }; 196 static boolean_t arpinit_done[MAXCPU]; 197 198 if (!arpinit_done[mycpuid]) { 199 arpinit_done[mycpuid] = TRUE; 200 callout_init(&arptimer_ch[mycpuid]); 201 callout_reset(&arptimer_ch[mycpuid], hz, arptimer, NULL); 202 } 203 if (rt->rt_flags & RTF_GATEWAY) 204 return; 205 206 switch (req) { 207 case RTM_ADD: 208 /* 209 * XXX: If this is a manually added route to interface 210 * such as older version of routed or gated might provide, 211 * restore cloning bit. 212 */ 213 if (!(rt->rt_flags & RTF_HOST) && 214 SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff) 215 rt->rt_flags |= RTF_CLONING; 216 if (rt->rt_flags & RTF_CLONING) { 217 /* 218 * Case 1: This route should come from a route to iface. 219 */ 220 rt_setgate(rt, rt_key(rt), 221 (struct sockaddr *)&null_sdl); 222 gate = rt->rt_gateway; 223 SDL(gate)->sdl_type = rt->rt_ifp->if_type; 224 SDL(gate)->sdl_index = rt->rt_ifp->if_index; 225 rt->rt_expire = time_second; 226 break; 227 } 228 /* Announce a new entry if requested. */ 229 if (rt->rt_flags & RTF_ANNOUNCE) 230 arprequest(rt->rt_ifp, 231 &SIN(rt_key(rt))->sin_addr, 232 &SIN(rt_key(rt))->sin_addr, 233 LLADDR(SDL(gate))); 234 /*FALLTHROUGH*/ 235 case RTM_RESOLVE: 236 if (gate->sa_family != AF_LINK || 237 gate->sa_len < sizeof(struct sockaddr_dl)) { 238 log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n"); 239 break; 240 } 241 SDL(gate)->sdl_type = rt->rt_ifp->if_type; 242 SDL(gate)->sdl_index = rt->rt_ifp->if_index; 243 if (la != NULL) 244 break; /* This happens on a route change */ 245 /* 246 * Case 2: This route may come from cloning, or a manual route 247 * add with a LL address. 248 */ 249 R_Malloc(la, struct llinfo_arp *, sizeof *la); 250 rt->rt_llinfo = la; 251 if (la == NULL) { 252 log(LOG_DEBUG, "arp_rtrequest: malloc failed\n"); 253 break; 254 } 255 bzero(la, sizeof *la); 256 la->la_rt = rt; 257 rt->rt_flags |= RTF_LLINFO; 258 LIST_INSERT_HEAD(&llinfo_arp_list[mycpuid], la, la_le); 259 260 #ifdef INET 261 /* 262 * This keeps the multicast addresses from showing up 263 * in `arp -a' listings as unresolved. It's not actually 264 * functional. Then the same for broadcast. 265 */ 266 if (IN_MULTICAST(ntohl(SIN(rt_key(rt))->sin_addr.s_addr)) && 267 rt->rt_ifp->if_type != IFT_ARCNET) { 268 ETHER_MAP_IP_MULTICAST(&SIN(rt_key(rt))->sin_addr, 269 LLADDR(SDL(gate))); 270 SDL(gate)->sdl_alen = 6; 271 rt->rt_expire = 0; 272 } 273 if (in_broadcast(SIN(rt_key(rt))->sin_addr, rt->rt_ifp)) { 274 memcpy(LLADDR(SDL(gate)), rt->rt_ifp->if_broadcastaddr, 275 rt->rt_ifp->if_addrlen); 276 SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen; 277 rt->rt_expire = 0; 278 } 279 #endif 280 281 if (SIN(rt_key(rt))->sin_addr.s_addr == 282 (IA_SIN(rt->rt_ifa))->sin_addr.s_addr) { 283 /* 284 * This test used to be 285 * if (loif.if_flags & IFF_UP) 286 * It allowed local traffic to be forced 287 * through the hardware by configuring the 288 * loopback down. However, it causes problems 289 * during network configuration for boards 290 * that can't receive packets they send. It 291 * is now necessary to clear "useloopback" and 292 * remove the route to force traffic out to 293 * the hardware. 294 */ 295 rt->rt_expire = 0; 296 bcopy(IF_LLADDR(rt->rt_ifp), LLADDR(SDL(gate)), 297 SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen); 298 if (useloopback) 299 rt->rt_ifp = loif; 300 } 301 break; 302 303 case RTM_DELETE: 304 if (la == NULL) 305 break; 306 LIST_REMOVE(la, la_le); 307 rt->rt_llinfo = NULL; 308 rt->rt_flags &= ~RTF_LLINFO; 309 if (la->la_hold != NULL) 310 m_freem(la->la_hold); 311 Free(la); 312 } 313 } 314 315 /* 316 * Broadcast an ARP request. Caller specifies: 317 * - arp header source ip address 318 * - arp header target ip address 319 * - arp header source ethernet address 320 */ 321 static void 322 arprequest(struct ifnet *ifp, struct in_addr *sip, struct in_addr *tip, 323 u_char *enaddr) 324 { 325 struct mbuf *m; 326 struct ether_header *eh; 327 struct arc_header *arh; 328 struct arphdr *ah; 329 struct sockaddr sa; 330 static u_char llcx[] = { 0x82, 0x40, LLC_SNAP_LSAP, LLC_SNAP_LSAP, 331 LLC_UI, 0x00, 0x00, 0x00, 0x08, 0x06 }; 332 u_short ar_hrd; 333 334 if ((m = m_gethdr(MB_DONTWAIT, MT_DATA)) == NULL) 335 return; 336 m->m_pkthdr.rcvif = (struct ifnet *)NULL; 337 338 switch (ifp->if_type) { 339 case IFT_ARCNET: 340 ar_hrd = htons(ARPHRD_ARCNET); 341 342 m->m_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr)); 343 m->m_pkthdr.len = m->m_len; 344 MH_ALIGN(m, m->m_len); 345 346 arh = (struct arc_header *)sa.sa_data; 347 arh->arc_dhost = ifp->if_broadcastaddr[0]; 348 arh->arc_type = ARCTYPE_ARP; 349 350 ah = mtod(m, struct arphdr *); 351 break; 352 353 case IFT_ISO88025: 354 ar_hrd = htons(ARPHRD_IEEE802); 355 356 m->m_len = (sizeof llcx) + 357 arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr)); 358 m->m_pkthdr.len = m->m_len; 359 MH_ALIGN(m, m->m_len); 360 361 memcpy(mtod(m, caddr_t), llcx, sizeof llcx); 362 memcpy(sa.sa_data, ifp->if_broadcastaddr, ifp->if_addrlen); 363 memcpy(sa.sa_data + 6, enaddr, 6); 364 sa.sa_data[6] |= TR_RII; 365 sa.sa_data[12] = TR_AC; 366 sa.sa_data[13] = TR_LLC_FRAME; 367 368 ah = (struct arphdr *)(mtod(m, char *) + sizeof llcx); 369 break; 370 case IFT_FDDI: 371 case IFT_ETHER: 372 /* 373 * This may not be correct for types not explicitly 374 * listed, but this is our best guess 375 */ 376 default: 377 ar_hrd = htons(ARPHRD_ETHER); 378 379 m->m_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr)); 380 m->m_pkthdr.len = m->m_len; 381 MH_ALIGN(m, m->m_len); 382 383 eh = (struct ether_header *)sa.sa_data; 384 /* if_output() will not swap */ 385 eh->ether_type = htons(ETHERTYPE_ARP); 386 memcpy(eh->ether_dhost, ifp->if_broadcastaddr, ifp->if_addrlen); 387 388 ah = mtod(m, struct arphdr *); 389 break; 390 } 391 392 ah->ar_hrd = ar_hrd; 393 ah->ar_pro = htons(ETHERTYPE_IP); 394 ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 395 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 396 ah->ar_op = htons(ARPOP_REQUEST); 397 memcpy(ar_sha(ah), enaddr, ah->ar_hln); 398 memset(ar_tha(ah), 0, ah->ar_hln); 399 memcpy(ar_spa(ah), sip, ah->ar_pln); 400 memcpy(ar_tpa(ah), tip, ah->ar_pln); 401 402 sa.sa_family = AF_UNSPEC; 403 sa.sa_len = sizeof sa; 404 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)NULL); 405 } 406 407 /* 408 * Resolve an IP address into an ethernet address. If success, 409 * desten is filled in. If there is no entry in arptab, 410 * set one up and broadcast a request for the IP address. 411 * Hold onto this mbuf and resend it once the address 412 * is finally resolved. A return value of 1 indicates 413 * that desten has been filled in and the packet should be sent 414 * normally; a 0 return indicates that the packet has been 415 * taken over here, either now or for later transmission. 416 */ 417 int 418 arpresolve( 419 struct ifnet *ifp, 420 struct rtentry *rt0, 421 struct mbuf *m, 422 struct sockaddr *dst, 423 u_char *desten) 424 { 425 struct rtentry *rt; 426 struct llinfo_arp *la = NULL; 427 struct sockaddr_dl *sdl; 428 429 if (m->m_flags & M_BCAST) { /* broadcast */ 430 memcpy(desten, ifp->if_broadcastaddr, ifp->if_addrlen); 431 return (1); 432 } 433 if (m->m_flags & M_MCAST && ifp->if_type != IFT_ARCNET) {/* multicast */ 434 ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten); 435 return (1); 436 } 437 if (rt0 != NULL) { 438 if (rt_llroute(dst, rt0, &rt) != 0) { 439 m_freem(m); 440 return 0; 441 } 442 la = rt->rt_llinfo; 443 } 444 if (la == NULL) { 445 la = arplookup(SIN(dst)->sin_addr.s_addr, TRUE, FALSE); 446 if (la != NULL) 447 rt = la->la_rt; 448 } 449 if (la == NULL || rt == NULL) { 450 log(LOG_DEBUG, "arpresolve: can't allocate llinfo for %s%s%s\n", 451 inet_ntoa(SIN(dst)->sin_addr), la ? "la" : " ", 452 rt ? "rt" : ""); 453 m_freem(m); 454 return (0); 455 } 456 sdl = SDL(rt->rt_gateway); 457 /* 458 * Check the address family and length is valid, the address 459 * is resolved; otherwise, try to resolve. 460 */ 461 if ((rt->rt_expire == 0 || rt->rt_expire > time_second) && 462 sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) { 463 /* 464 * If entry has an expiry time and it is approaching, 465 * see if we need to send an ARP request within this 466 * arpt_down interval. 467 */ 468 if ((rt->rt_expire != 0) && 469 (time_second + la->la_preempt > rt->rt_expire)) { 470 arprequest(ifp, 471 &SIN(rt->rt_ifa->ifa_addr)->sin_addr, 472 &SIN(dst)->sin_addr, 473 IF_LLADDR(ifp)); 474 la->la_preempt--; 475 } 476 477 bcopy(LLADDR(sdl), desten, sdl->sdl_alen); 478 return 1; 479 } 480 /* 481 * If ARP is disabled on this interface, stop. 482 * XXX 483 * Probably should not allocate empty llinfo struct if we are 484 * not going to be sending out an arp request. 485 */ 486 if (ifp->if_flags & IFF_NOARP) { 487 m_freem(m); 488 return (0); 489 } 490 /* 491 * There is an arptab entry, but no ethernet address 492 * response yet. Replace the held mbuf with this 493 * latest one. 494 */ 495 if (la->la_hold != NULL) 496 m_freem(la->la_hold); 497 la->la_hold = m; 498 if (rt->rt_expire || ((rt->rt_flags & RTF_STATIC) && !sdl->sdl_alen)) { 499 rt->rt_flags &= ~RTF_REJECT; 500 if (la->la_asked == 0 || rt->rt_expire != time_second) { 501 rt->rt_expire = time_second; 502 if (la->la_asked++ < arp_maxtries) { 503 arprequest(ifp, 504 &SIN(rt->rt_ifa->ifa_addr)->sin_addr, 505 &SIN(dst)->sin_addr, 506 IF_LLADDR(ifp)); 507 } else { 508 rt->rt_flags |= RTF_REJECT; 509 rt->rt_expire += arpt_down; 510 la->la_asked = 0; 511 la->la_preempt = arp_maxtries; 512 } 513 514 } 515 } 516 return (0); 517 } 518 519 /* 520 * Common length and type checks are done here, 521 * then the protocol-specific routine is called. 522 */ 523 static void 524 arpintr(struct netmsg *msg) 525 { 526 struct mbuf *m = ((struct netmsg_packet *)msg)->nm_packet; 527 struct arphdr *ar; 528 u_short ar_hrd; 529 530 if (m->m_len < sizeof(struct arphdr) && 531 ((m = m_pullup(m, sizeof(struct arphdr))) == NULL)) { 532 log(LOG_ERR, "arp: runt packet -- m_pullup failed\n"); 533 goto out2; 534 } 535 ar = mtod(m, struct arphdr *); 536 537 ar_hrd = ntohs(ar->ar_hrd); 538 if (ar_hrd != ARPHRD_ETHER && 539 ar_hrd != ARPHRD_IEEE802 && 540 ar_hrd != ARPHRD_ARCNET) { 541 log(LOG_ERR, 542 "arp: unknown hardware address format (0x%2D)\n", 543 (unsigned char *)&ar->ar_hrd, ""); 544 goto out1; 545 } 546 547 if (m->m_pkthdr.len < arphdr_len(ar) && 548 (m = m_pullup(m, arphdr_len(ar))) == NULL) { 549 log(LOG_ERR, "arp: runt packet\n"); 550 goto out1; 551 } 552 553 switch (ntohs(ar->ar_pro)) { 554 #ifdef INET 555 case ETHERTYPE_IP: 556 in_arpinput(m); 557 goto out2; 558 #endif 559 } 560 out1: 561 m_freem(m); 562 out2: 563 ; 564 /* msg was embedded in the mbuf, do not reply! */ 565 } 566 567 #ifdef INET 568 /* 569 * ARP for Internet protocols on 10 Mb/s Ethernet. 570 * Algorithm is that given in RFC 826. 571 * In addition, a sanity check is performed on the sender 572 * protocol address, to catch impersonators. 573 * We no longer handle negotiations for use of trailer protocol: 574 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent 575 * along with IP replies if we wanted trailers sent to us, 576 * and also sent them in response to IP replies. 577 * This allowed either end to announce the desire to receive 578 * trailer packets. 579 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, 580 * but formerly didn't normally send requests. 581 */ 582 static int log_arp_wrong_iface = 1; 583 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW, 584 &log_arp_wrong_iface, 0, 585 "log arp packets arriving on the wrong interface"); 586 587 static void 588 arp_update_oncpu(struct mbuf *m, in_addr_t saddr, boolean_t create, 589 boolean_t dologging) 590 { 591 struct arphdr *ah = mtod(m, struct arphdr *); 592 struct ifnet *ifp = m->m_pkthdr.rcvif; 593 struct llinfo_arp *la; 594 struct sockaddr_dl *sdl; 595 struct rtentry *rt; 596 int cpu = mycpuid; 597 598 la = arplookup(saddr, create, FALSE); 599 if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) { 600 struct in_addr isaddr = { saddr }; 601 602 /* the following is not an error when doing bridging */ 603 if (rt->rt_ifp != ifp) { 604 if (dologging && log_arp_wrong_iface && cpu == 0) { 605 log(LOG_ERR, 606 "arp: %s is on %s " 607 "but got reply from %*D on %s\n", 608 inet_ntoa(isaddr), 609 rt->rt_ifp->if_xname, 610 ifp->if_addrlen, (u_char *)ar_sha(ah), ":", 611 ifp->if_xname); 612 } 613 return; 614 } 615 if (sdl->sdl_alen && 616 bcmp(ar_sha(ah), LLADDR(sdl), sdl->sdl_alen)) { 617 if (rt->rt_expire != 0) { 618 if (dologging && cpu == 0) { 619 log(LOG_INFO, 620 "arp: %s moved from %*D to %*D on %s\n", 621 inet_ntoa(isaddr), 622 ifp->if_addrlen, (u_char *)LLADDR(sdl), 623 ":", ifp->if_addrlen, 624 (u_char *)ar_sha(ah), ":", 625 ifp->if_xname); 626 } 627 } else { 628 if (dologging && cpu == 0) { 629 log(LOG_ERR, 630 "arp: %*D attempts to modify permanent entry for %s on %s\n", 631 ifp->if_addrlen, (u_char *)ar_sha(ah), ":", 632 inet_ntoa(isaddr), ifp->if_xname); 633 } 634 return; 635 } 636 } 637 /* 638 * sanity check for the address length. 639 * XXX this does not work for protocols with variable address 640 * length. -is 641 */ 642 if (dologging && sdl->sdl_alen && sdl->sdl_alen != ah->ar_hln && 643 cpu == 0) 644 { 645 log(LOG_WARNING, 646 "arp from %*D: new addr len %d, was %d", 647 ifp->if_addrlen, (u_char *) ar_sha(ah), ":", 648 ah->ar_hln, sdl->sdl_alen); 649 } 650 if (ifp->if_addrlen != ah->ar_hln) { 651 if (dologging && cpu == 0) { 652 log(LOG_WARNING, 653 "arp from %*D: addr len: new %d, i/f %d (ignored)", 654 ifp->if_addrlen, (u_char *) ar_sha(ah), ":", 655 ah->ar_hln, ifp->if_addrlen); 656 } 657 return; 658 } 659 memcpy(LLADDR(sdl), ar_sha(ah), sdl->sdl_alen = ah->ar_hln); 660 /* 661 * If we receive an arp from a token-ring station over 662 * a token-ring nic then try to save the source 663 * routing info. 664 */ 665 if (ifp->if_type == IFT_ISO88025) { 666 struct iso88025_header *th = 667 (struct iso88025_header *)m->m_pkthdr.header; 668 struct iso88025_sockaddr_dl_data *trld = 669 SDL_ISO88025(sdl); 670 int rif_len; 671 672 rif_len = TR_RCF_RIFLEN(th->rcf); 673 if ((th->iso88025_shost[0] & TR_RII) && 674 (rif_len > 2)) { 675 trld->trld_rcf = th->rcf; 676 trld->trld_rcf ^= htons(TR_RCF_DIR); 677 memcpy(trld->trld_route, th->rd, rif_len - 2); 678 trld->trld_rcf &= ~htons(TR_RCF_BCST_MASK); 679 /* 680 * Set up source routing information for 681 * reply packet (XXX) 682 */ 683 m->m_data -= rif_len; 684 m->m_len += rif_len; 685 m->m_pkthdr.len += rif_len; 686 } else { 687 th->iso88025_shost[0] &= ~TR_RII; 688 trld->trld_rcf = 0; 689 } 690 m->m_data -= 8; 691 m->m_len += 8; 692 m->m_pkthdr.len += 8; 693 th->rcf = trld->trld_rcf; 694 } 695 if (rt->rt_expire != 0) 696 rt->rt_expire = time_second + arpt_keep; 697 rt->rt_flags &= ~RTF_REJECT; 698 la->la_asked = 0; 699 la->la_preempt = arp_maxtries; 700 701 /* 702 * This particular cpu might have been holding an mbuf 703 * pending ARP resolution. If so, transmit the mbuf now. 704 */ 705 if (la->la_hold != NULL) { 706 m_adj(la->la_hold, sizeof(struct ether_header)); 707 lwkt_serialize_enter(ifp->if_serializer); 708 (*ifp->if_output)(ifp, la->la_hold, rt_key(rt), rt); 709 lwkt_serialize_exit(ifp->if_serializer); 710 la->la_hold = NULL; 711 } 712 } 713 } 714 715 #ifdef SMP 716 717 struct netmsg_arp_update { 718 struct netmsg netmsg; 719 struct mbuf *m; 720 in_addr_t saddr; 721 boolean_t create; 722 }; 723 724 static void arp_update_msghandler(struct netmsg *netmsg); 725 726 #endif 727 728 /* 729 * Called from arpintr() - this routine is run from a single cpu. 730 */ 731 static void 732 in_arpinput(struct mbuf *m) 733 { 734 struct arphdr *ah; 735 struct ifnet *ifp = m->m_pkthdr.rcvif; 736 struct ether_header *eh; 737 struct arc_header *arh; 738 struct iso88025_header *th = (struct iso88025_header *)NULL; 739 struct rtentry *rt; 740 struct ifaddr *ifa; 741 struct in_ifaddr *ia; 742 struct sockaddr sa; 743 struct in_addr isaddr, itaddr, myaddr; 744 #ifdef SMP 745 struct netmsg_arp_update msg; 746 #endif 747 u_int8_t *enaddr = NULL; 748 int op; 749 int req_len; 750 751 req_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr)); 752 if (m->m_len < req_len && (m = m_pullup(m, req_len)) == NULL) { 753 log(LOG_ERR, "in_arp: runt packet -- m_pullup failed\n"); 754 return; 755 } 756 757 ah = mtod(m, struct arphdr *); 758 op = ntohs(ah->ar_op); 759 memcpy(&isaddr, ar_spa(ah), sizeof isaddr); 760 memcpy(&itaddr, ar_tpa(ah), sizeof itaddr); 761 /* 762 * Check both target and sender IP addresses: 763 * 764 * If we receive the packet on the interface owning the address, 765 * then accept the address. 766 * 767 * For a bridge, we accept the address if the receive interface and 768 * the interface owning the address are on the same bridge. 769 * (This will change slightly when we have clusters of interfaces). 770 */ 771 LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) { 772 /* Skip all ia's which don't match */ 773 if (itaddr.s_addr != ia->ia_addr.sin_addr.s_addr) 774 continue; 775 776 if (ia->ia_ifp == ifp) 777 goto match; 778 779 if (ifp->if_bridge && ia->ia_ifp && 780 ifp->if_bridge == ia->ia_ifp->if_bridge) 781 goto match; 782 783 #ifdef CARP 784 /* 785 * If the interface does not match, but the recieving interface 786 * is part of carp, we call carp_iamatch to see if this is a 787 * request for the virtual host ip. 788 * XXX: This is really ugly! 789 */ 790 if (ifp->if_carp != NULL && 791 carp_iamatch(ifp->if_carp, ia, &isaddr, &enaddr) && 792 itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) 793 goto match; 794 #endif 795 } 796 LIST_FOREACH(ia, INADDR_HASH(isaddr.s_addr), ia_hash) { 797 /* Skip all ia's which don't match */ 798 if (isaddr.s_addr != ia->ia_addr.sin_addr.s_addr) 799 continue; 800 801 if (ia->ia_ifp == ifp) 802 goto match; 803 804 if (ifp->if_bridge && ia->ia_ifp && 805 ifp->if_bridge == ia->ia_ifp->if_bridge) 806 goto match; 807 } 808 /* 809 * No match, use the first inet address on the receive interface 810 * as a dummy address for the rest of the function. 811 */ 812 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 813 if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET) { 814 ia = ifatoia(ifa); 815 goto match; 816 } 817 } 818 /* 819 * If we got here, we didn't find any suitable interface, 820 * so drop the packet. 821 */ 822 m_freem(m); 823 return; 824 825 match: 826 if (!enaddr) 827 enaddr = (u_int8_t *)IF_LLADDR(ifp); 828 myaddr = ia->ia_addr.sin_addr; 829 if (!bcmp(ar_sha(ah), enaddr, ifp->if_addrlen)) { 830 m_freem(m); /* it's from me, ignore it. */ 831 return; 832 } 833 if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 834 log(LOG_ERR, 835 "arp: link address is broadcast for IP address %s!\n", 836 inet_ntoa(isaddr)); 837 m_freem(m); 838 return; 839 } 840 if (isaddr.s_addr == myaddr.s_addr && myaddr.s_addr != 0) { 841 log(LOG_ERR, 842 "arp: %*D is using my IP address %s!\n", 843 ifp->if_addrlen, (u_char *)ar_sha(ah), ":", 844 inet_ntoa(isaddr)); 845 itaddr = myaddr; 846 goto reply; 847 } 848 #ifdef SMP 849 netmsg_init(&msg.netmsg, &curthread->td_msgport, 0, 850 arp_update_msghandler); 851 msg.m = m; 852 msg.saddr = isaddr.s_addr; 853 msg.create = (itaddr.s_addr == myaddr.s_addr); 854 lwkt_domsg(rtable_portfn(0), &msg.netmsg.nm_lmsg, 0); 855 #endif 856 arp_update_oncpu(m, isaddr.s_addr, (itaddr.s_addr == myaddr.s_addr), 857 TRUE); 858 reply: 859 if (op != ARPOP_REQUEST) { 860 m_freem(m); 861 return; 862 } 863 if (itaddr.s_addr == myaddr.s_addr) { 864 /* I am the target */ 865 memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); 866 memcpy(ar_sha(ah), enaddr, ah->ar_hln); 867 } else { 868 struct llinfo_arp *la; 869 870 la = arplookup(itaddr.s_addr, FALSE, SIN_PROXY); 871 if (la == NULL) { 872 struct sockaddr_in sin; 873 874 if (!arp_proxyall) { 875 m_freem(m); 876 return; 877 } 878 879 bzero(&sin, sizeof sin); 880 sin.sin_family = AF_INET; 881 sin.sin_len = sizeof sin; 882 sin.sin_addr = itaddr; 883 884 rt = rtpurelookup((struct sockaddr *)&sin); 885 if (rt == NULL) { 886 m_freem(m); 887 return; 888 } 889 --rt->rt_refcnt; 890 /* 891 * Don't send proxies for nodes on the same interface 892 * as this one came out of, or we'll get into a fight 893 * over who claims what Ether address. 894 */ 895 if (rt->rt_ifp == ifp) { 896 m_freem(m); 897 return; 898 } 899 memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); 900 memcpy(ar_sha(ah), enaddr, ah->ar_hln); 901 #ifdef DEBUG_PROXY 902 kprintf("arp: proxying for %s\n", inet_ntoa(itaddr)); 903 #endif 904 } else { 905 struct sockaddr_dl *sdl; 906 907 rt = la->la_rt; 908 memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); 909 sdl = SDL(rt->rt_gateway); 910 memcpy(ar_sha(ah), LLADDR(sdl), ah->ar_hln); 911 } 912 } 913 914 memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); 915 memcpy(ar_spa(ah), &itaddr, ah->ar_pln); 916 ah->ar_op = htons(ARPOP_REPLY); 917 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 918 switch (ifp->if_type) { 919 case IFT_ARCNET: 920 arh = (struct arc_header *)sa.sa_data; 921 arh->arc_dhost = *ar_tha(ah); 922 arh->arc_type = ARCTYPE_ARP; 923 break; 924 case IFT_ISO88025: 925 /* Re-arrange the source/dest address */ 926 memcpy(th->iso88025_dhost, th->iso88025_shost, 927 sizeof th->iso88025_dhost); 928 memcpy(th->iso88025_shost, IF_LLADDR(ifp), 929 sizeof th->iso88025_shost); 930 /* Set the source routing bit if neccesary */ 931 if (th->iso88025_dhost[0] & TR_RII) { 932 th->iso88025_dhost[0] &= ~TR_RII; 933 if (TR_RCF_RIFLEN(th->rcf) > 2) 934 th->iso88025_shost[0] |= TR_RII; 935 } 936 /* Copy the addresses, ac and fc into sa_data */ 937 memcpy(sa.sa_data, th->iso88025_dhost, 938 (sizeof th->iso88025_dhost) * 2); 939 sa.sa_data[(sizeof th->iso88025_dhost) * 2] = TR_AC; 940 sa.sa_data[(sizeof th->iso88025_dhost) * 2 + 1] = TR_LLC_FRAME; 941 break; 942 case IFT_ETHER: 943 case IFT_FDDI: 944 /* 945 * May not be correct for types not explictly 946 * listed, but it is our best guess. 947 */ 948 default: 949 eh = (struct ether_header *)sa.sa_data; 950 memcpy(eh->ether_dhost, ar_tha(ah), sizeof eh->ether_dhost); 951 eh->ether_type = htons(ETHERTYPE_ARP); 952 break; 953 } 954 sa.sa_family = AF_UNSPEC; 955 sa.sa_len = sizeof sa; 956 lwkt_serialize_enter(ifp->if_serializer); 957 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); 958 lwkt_serialize_exit(ifp->if_serializer); 959 return; 960 } 961 962 #ifdef SMP 963 964 static 965 void 966 arp_update_msghandler(struct netmsg *netmsg) 967 { 968 struct netmsg_arp_update *msg = (struct netmsg_arp_update *)netmsg; 969 int nextcpu; 970 971 arp_update_oncpu(msg->m, msg->saddr, msg->create, FALSE); 972 973 nextcpu = mycpuid + 1; 974 if (nextcpu < ncpus) { 975 lwkt_forwardmsg(rtable_portfn(nextcpu), &msg->netmsg.nm_lmsg); 976 } else { 977 lwkt_replymsg(&msg->netmsg.nm_lmsg, 0); 978 } 979 } 980 981 #endif 982 983 #endif 984 985 /* 986 * Free an arp entry. If the arp entry is actively referenced or represents 987 * a static entry we only clear it back to an unresolved state, otherwise 988 * we destroy the entry entirely. 989 * 990 * Note that static entries are created when route add ... -interface is used 991 * to create an interface route to a (direct) destination. 992 */ 993 static void 994 arptfree(struct llinfo_arp *la) 995 { 996 struct rtentry *rt = la->la_rt; 997 struct sockaddr_dl *sdl; 998 999 if (rt == NULL) 1000 panic("arptfree"); 1001 sdl = SDL(rt->rt_gateway); 1002 if (sdl != NULL && 1003 ((rt->rt_refcnt > 0 && sdl->sdl_family == AF_LINK) || 1004 (rt->rt_flags & RTF_STATIC))) { 1005 sdl->sdl_alen = 0; 1006 la->la_preempt = la->la_asked = 0; 1007 rt->rt_flags &= ~RTF_REJECT; 1008 return; 1009 } 1010 rtrequest(RTM_DELETE, rt_key(rt), NULL, rt_mask(rt), 0, NULL); 1011 } 1012 1013 /* 1014 * Lookup or enter a new address in arptab. 1015 */ 1016 static struct llinfo_arp * 1017 arplookup(in_addr_t addr, boolean_t create, boolean_t proxy) 1018 { 1019 struct rtentry *rt; 1020 struct sockaddr_inarp sin = { sizeof sin, AF_INET }; 1021 const char *why = NULL; 1022 1023 sin.sin_addr.s_addr = addr; 1024 sin.sin_other = proxy ? SIN_PROXY : 0; 1025 if (create) 1026 rt = rtlookup((struct sockaddr *)&sin); 1027 else 1028 rt = rtpurelookup((struct sockaddr *)&sin); 1029 if (rt == NULL) 1030 return (NULL); 1031 rt->rt_refcnt--; 1032 1033 if (rt->rt_flags & RTF_GATEWAY) 1034 why = "host is not on local network"; 1035 else if (!(rt->rt_flags & RTF_LLINFO)) 1036 why = "could not allocate llinfo"; 1037 else if (rt->rt_gateway->sa_family != AF_LINK) 1038 why = "gateway route is not ours"; 1039 1040 if (why) { 1041 if (create) { 1042 log(LOG_DEBUG, "arplookup %s failed: %s\n", 1043 inet_ntoa(sin.sin_addr), why); 1044 } 1045 if (rt->rt_refcnt <= 0 && (rt->rt_flags & RTF_WASCLONED)) { 1046 /* No references to this route. Purge it. */ 1047 rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway, 1048 rt_mask(rt), rt->rt_flags, NULL); 1049 } 1050 return (NULL); 1051 } 1052 return (rt->rt_llinfo); 1053 } 1054 1055 void 1056 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 1057 { 1058 if (IA_SIN(ifa)->sin_addr.s_addr != INADDR_ANY) 1059 arprequest(ifp, &IA_SIN(ifa)->sin_addr, &IA_SIN(ifa)->sin_addr, 1060 IF_LLADDR(ifp)); 1061 ifa->ifa_rtrequest = arp_rtrequest; 1062 ifa->ifa_flags |= RTF_CLONING; 1063 } 1064 1065 void 1066 arp_ifinit2(struct ifnet *ifp, struct ifaddr *ifa, u_char *enaddr) 1067 { 1068 if (IA_SIN(ifa)->sin_addr.s_addr != INADDR_ANY) 1069 arprequest(ifp, &IA_SIN(ifa)->sin_addr, &IA_SIN(ifa)->sin_addr, 1070 enaddr); 1071 ifa->ifa_rtrequest = arp_rtrequest; 1072 ifa->ifa_flags |= RTF_CLONING; 1073 } 1074 1075 static void 1076 arp_init(void) 1077 { 1078 int cpu; 1079 1080 for (cpu = 0; cpu < ncpus2; cpu++) 1081 LIST_INIT(&llinfo_arp_list[cpu]); 1082 netisr_register(NETISR_ARP, cpu0_portfn, arpintr); 1083 } 1084 1085 SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0); 1086